The Mid-Nineteenth Through the Early Twentieth Century Essay - 1

The Mid-Nineteenth Through the Early Twentieth Century - Essay Example He also condemned Christianity as it hindered the development of human instincts. He further went on to state that man can only be saved by the evolution of a superman who would create his rules based on his own instincts. He will not adhere to any set rules or code of conducts that have been imposed by the civilization of mankind. He firmly believed in his principles even during the late 19th century which was heralded as an era of scientific progress and development. Many European scholars considered the thoughts expressed by Nietzsche as an expression of the inner energy of man. Like Nietzsche, Russian novelist Fyodor Dostoevsky also believed that human were irrational and rebellious and did not believe in the era of enlightenment or the age of human reason. He was totally against science and reasoning. He strongly believed that man could not fit into a tailor-made world and that he was bound to undergo suffering and act irrationally in order to assert their individuality. There w as more to the existence of human beings than merely reason and perform worldly duties expected from him. This, he believed, was the freedom of every man as it is created by him and not put down by the society in which he lives.

Sustainable engineering Essay Example | Topics and Well Written Essays - 2250 words

Sustainable engineering - Essay Example employed schemes are the building research establishment environmental assessment method(BREEAM) and leadership in energy and environmental design(LEED). BREEAM was officially launched by the building research establishment(BRE) and consequently adopted by the United Kingdom as one of its systems. LEED was by us institution United States green building council (USGBC) and officially accepted as the benchmark for green building practices. All these two schemes are based on effective system for collecting credits that are used for a wide of building, both the existing buildings and the new buildings. These systems cover a wide range of issues that include energy, pollution, building site, water indoor environmental quality and materials one of the most important in both the two schemes that is the key sustainable development is energy consumption expressed in another language as resulting to carbon emissions from the buildings. It is therefore clear that robust building environmental assessment schemes will possibly play a very critical role in assessing the building energy performance. According to Lee and Bumet(2008) it is important to understand this schemes interms of their scopes, performance criteria, credit scales and methodologies. Lee et al conducted a comparison of the baseline buildings, their performance criteria, credit scales and their simulative tools between a number of schemes while Asdrubali et al (2008) undertook a comparative study of energy regulations in Spain and Italy based on a semi-detached house. In this study more emphasis is put on the assessment of energy performance of new building within the BREEAM and LEED. For easy assessment of the energy performance of buildings and effective calculation of the corresponding energy rating in BREEAM and LEED schemes, a computational simulation was applied. Even though there are many energy simulation software that are available in the market, there is need to choose the one that suits the aim of

Profiling Genome of Tibetan Chicken

Profiling Genome of Tibetan Chicken Profiling the genome-wide DNAmethylation pattern of Tibetan chicken  using whole genome bisulfite sequencing Abstract Background: Tibetan chickens living at high altitudes show specific adaptations to high-altitude conditions, but the epigenetic modification bases of these adaptations havent been characterized. Results: We investigated the genome-wide DNA methylation patterns in Tibetan chicken blood using whole genome bisulfite sequencing (WGBS). Generally, Tibetan chicken exhibited analogous methylation pattern with that of lowland chiken. A total of 3.92% of genomic cytosines were methylcytosines, and 51.22% of cytosines in CG contexts were methylated which was less than those in lowland chicken (55.69%). Moreover, the base next to methylcytosine of mCHG in Tibetan chicken had a preference for T, which was different from that in lowland chicken. In Tibetan chicken, the methylation levels in the promoter were relatively low, while the gene body maintained hypomethylated. DNA methylation levels in upstream regions of the transcription start site (TSS) of geneshad a negative relationship with the gene expression level, and the DNA methylation of gene-body were also negatively related to gene expression. Conclusions: We firstly generated the genome-wide DNA methylation patterns in Tibetan chicken, and our results will be helpful for future epigenetic studies in adaptations to high-altitude conditions and provide a new idea for the prevention and treatment of mountain sickness and other hypoxia-related diseases to human. Keywords: Epigenetics, DNA methylation, MethylC-Seq, highland chicken, adaptation, extreme environment.   Ã‚   Background DNA methylation is a crucial epigenetic modification that plays a vital role in genomic imprinting [1], transcriptional repression [2], and chromatin activation [3]. In recent years, we have gained knowledge on the association of DNA methylation with cellular differentiation, development, and disease, however, little information is available concerning the DNA methylation modifications under long-term extreme environment. Environmental aspects influence through both genetic and epigenetic mechanisms [4, 5]. Several studies have tried to establish the relationship between environmental factors and DNA methylation in humans. It was reported that reduced global DNA methylation in whole blood was related to exposure to ambient air pollution at the home addresses of non adults [6]. In malignant cells, airborne benzene induce a significant decrease in the methylation of LINE-1 and AluI, and increasing airborne benzene levels can cause hypermethylation in p15 and hypomethylation in MAGE-1 [7]. The average level of methylation in p16 was increased in patients with benzene poisoning compared with control group, while no alternation was observed in the p15 methylation [8]. Korea et al. revealed that most organochlorine (OC) pesticides were inversely and significantly related to the methylation of Alu [9]. In the prenatal pregnant women, lead exposure was inversely related to genomic DNA methylation in white blo od cells [10]. Moreover, base on the epigenetic inheritance mechanisms, adaptive traits that result from the environment can be transferred to the next generation. For instance, environment containing endocrine-disrupting chemicals can affect the germ line and promote disease across offspring via DNA methylation [11]. Above researchs shows that environmental conditions could induce DNA methylation alternation to to influence disease, prompting us to explore whether DNA methylation is associated with the unique adaptations of farm animals to hypoxia and high-dose ultraviolet radiation in high-altitude environments. The Tibetan chicken which lives in high-altitude environment has smaller body, lower heart rate, higher spleen rate and erythrocyte volum than low-altitude chicken. Previous research showed that humans relocating to high-altitudes might undergo acute mountain sickness, high-altitude pulmonary edema, and high-altitude cerebral edema [12]. Whereas, the Tibetan chicken is greatly adapted to the low-oxygen and high-altitude environment and displays good performance in terms of survival and has high reproduction [13]. Therefore, investigation the genome-wide DNA methylation of Tibetan chicken, understanding the effects of DNA methylation on the plateau adaptability, may provide a new idea for the prevention and treatment of mountain sickness and other hypoxia-related diseases to human. In this study, we perform whole genome bisulfite sequencing (WGBS) on Tibetan chicken blood to analyze their global DNA methylation patterns. The DNA methylome distribution in the Tibetan chicken genome was shown for the first time. Our results will provided an important resource for exploring low-oxygen adaptation mechanism in high-altitude district. Methods Animals In this study, one Tibetan chicken was obtained from Xiangcheng County in the Ganzi Tibetan Autonomous Prefecture with the living place about 3500 meters above sea level. Blood samples were collected and stored at -20  °C for bisulfite sequencing. Total genomic DNA was collected from the blood with the use of a TIANamp Genomic DNA Kit (Tiangen, Beijing, China). All experiments in this study were performed in accordance with relevant guidelines and regulations, and were approved by the Science and Technology Department of Sichuan Province. MethylC-Seq library construction and sequencing DNA was fragmented by sonication with a Sonicator (Sonics Materials) to a mean size of approxi ­mately 250 bp, followed by blunt ending, 3à ¢Ã¢â€š ¬Ã‚ ²-end addition of dA, and adapter ligation, in which Illumina methylated adapters were used according to the manufacturers instructions (Illumina). The bisulfite conversion of Tibetan chicken DNA was carried out using ZYMO EZ DNA Methylation-Gold kit (Zymo Research, Irvine, CA, USA) and ampli ­fied via PCR with 12 cycles. Ultra-high-throughput pair-end sequencing was performed by the Illumina Genetic Analyzer (GA2) on the basis of manufacturer instructions. Raw GA sequencing data were processed using Illumina base-calling pipeline (SolexaPipeline-1.0). Data Filtering Data filtering was performed via the elimination of the adaptor sequences, contamination and low-quality reads from raw reads. Low-quality reads consist of three types including: 1) Contain adaptor sequence; 2) N base number over 10%; 3) The number of base whose quality less than 20 over 10% was trimmed, and the read which accord with one of them will be removed. Only cleaned data were used for the downstream analyses. Reads Alignment On the forward read of each read pair, observed cytosines were replaced with replaced with adenines, and the observed guanines were replaced with adenines on the reverse read of each read pair. The alignment form reads were then mapped to the alignment form gallus_gallus reference genome by SOAP aligner[14]. Each hit with a single placement with a minimum number of mismatches and and a clear operation chain was defined as unambiguous alignment (uniquely mapped reads) and was used for ascertainment of methyl-cytosine. The copy numbers of the local region was estimateed by calculating the the uniquely mapped reads. Estimating methylation levels Methylation level was determined by dividing the number of reads covering each mC by the total reads covering that cytosine, which was also equal the mC/C ratio at each reference cytosine. The function is showed as following: Methylation level = 100 * GO enrichment Analysis GO annotations of Tibetan chicken genes were downloaded from the Ensembl (ftp://ensembl.org/pub/current/otherdata/Gene_ontology/gallus_gallus_glean_gene.go). GO comparative analyses between inter ­ested genes groups were performed using BGI WEGO (http://wego.genomics.org.cn/cgi-bin/wego/index.pl). KEGG Pathway Analysis Different genes usually interact with each other to exercise their biological functions. Kyoto Encyclopedia of Genes and Genomesà ¯Ã‚ ¼Ã‹â€ KEGGà ¯Ã‚ ¼Ã¢â‚¬ °is the main public pathway database. Super geometry analyses were conducted to find the KEGG pathways enriched in genes differentially methylated compared to the whole genome. The calculation formula is the same as that in GO function analyses, N represents number of genes with pathway annotation; For the number, n is the number of differentially expressed genes corresponding N, M represents number of all genes which have a particular pathway annotation; m represents numbers of differentially expressed genes which have a particular pathway annotation. Pathway mapped Q value à ¢Ã¢â‚¬ °Ã‚ ¤ 0.05 defined as the pathway of significant enrichment. Through significant enrichment of the pathway, we can determine the most main in biochemical pathways and signal transduction pathways. Results       Global mapping of DNA methylation In the present study, blood samples from a Tibetan chicken were used to generate three libraries for genome-wide methylation sequencing. All libraries showed nearly complete bisulfite conversion (99.7%). A total of 41.3 Gb raw data were obtained from three blood samples. After data filtering, 151,345,614, 165,745,108 and 141,554,972 clean reads were generated for the three libraries, respectively. Of the total reads, 75.6% were mapped to the reference genome, with 28 X Whole-genome average coverage depth, which could reveal the data quantity of clean data because of the characteristics of bisulfite sequencing (Table 1 and 2). Cytosine patterns have 3 major types (CG, CHG and CHH, H represents non-G base, hereinafter inclusive) according to the sequence context. Therefore, we analyzed the relationships between effective sequencing depth and genome coverage for different cytosine patterns (Figure S1, S2). Figure S1 reveals that there is a negative correlation between the effective sequencing depth and the percentage of cytosine in genome. The Figure S2 shows that the distribution of genome coverage varies with sequencing depth accord with the Poisson distribution, and the depth of the distribution`s apex is near to the genome average sequencing depth. In additon, we performed effective coverage analysis base on three different levels: chromosome, gene region and genomic feature. The effective coverage of all cytosine in each chromosome ranges from 82.77% to 97.86%, except for 24.96% in chr17 , while the CpG effective coverage of each chromosome ranges from 86.74% to 97.5%, except for 23.58% in chr17 (Table S1). Moreover,coverage of all cytosine in CDS and intron region was 95.94% and 93.66%, respectivelyà ¯Ã‚ ¼Ã…’ and CG coverage in CDS and intron region was 96.04% and 93.45%, respectively (Table S2). DNA methylation patterns In Tibetan chicken, the methylation level of all genomic C sites was more than 3.9%. Patterns of Cytosine methylation in Tibetan chicken were found to have three major types (mCG, mCHG and mCHH) according to the sequence context. We discovered overall genome-wide levels of 51.22% CG, 0.4% CHG, and 0.45% CHH methylation in the Tibetan chicken (Table 3). In whole genome, the CG methylation occupied over 96% of cytosine methylation, which is the primary cytosine methylation pattern. However, the rate of mCHH was only 3% and the rate of mCHG was 1%(Fig. 1A). Methylation status of CG, CHG and CHH differ between species, even varies with different conditions concerning time, space and physiology within a single organism. Figure 1b showed that percentage of the methylation level of methyl-cytosine varies with methylation level. In the tibet chicken blood, more than 75 % of mCG sites were 60-100 % methylated (Fig. 1b). In addition, chromosome1 was used as an instance to illuminate the methyl-cytosine density distribution in chromosome, and the methyl-cytosine density showed large variations throughout the chromosome 1, which was similar to other chromosomes (Fig. 1c) Proximal Sequence Features Analysis To identify whether the particular local sequences were markedly enriched as the DNA methylome of Arabidopsis, we analyzed the sequence adjacent to sites of CG and non-CG methylation. The methylation ratios of all potential 9-mer sequences were calculated, and the methylated cytosine was located at the fourth position in these sequences (permitting an analysis of three bases upstream of CHG, and CHH methylation). As shown in figure 2, hardly a sequence preference was found in the CG-flanking regions of the hole genome or in the mCG-flanking regions. Moreover, the highest frequency base that next to the CHG cytosine in genome was A, followed by T and C, while the base following the mCHG methylcytosine has a preference for T, followed by A and C. In CHH context, the fifth position that proximal to the sites of cytosine has a preference for C, and the sixth position prefer to T, which is similar to the mCHH(Fig. 2). DNA methylation levels of different functional regions Different genomic features are associated with distinct regulation functions. To study the DNA methylation profile in different genomic features, the heat map was used to present the distribution of methylation level in the CDS, downstream, Genome, intron and upstream (fig. 3). The comparative analysis of mean DNA methylation levels revealed that different gennome regions showed distinguishing DNA methylation levels. Additionally, we analyzed DNA methylation patterns across the transcriptional units at whole genome level. In Tibet chicken, most of the promoter regions have an association with CpG islands and are hypomethylated, which showed a lower CG methylation level than the gene-body and the gene downstream. Moreover, methylation of CG declined sharply before the TSS and increased markedly towards the gene body regions and stayed at a plateau until the 3 end of the gene body, and two obvious peaks were present in the regions of the internol exon and the last exon (Fig. 3). The me thylation of CHG had the same varying tendency with the methylation of CG, but was characterised by mitigatory changes compared to the rapid changes of CG methylation. Furthermore, the methylation peaks of both CG and CHG were presented in the internal and last exons in which the methylation lows of CHH appeared. DNA methylation levels ofpromoter and genebody Methylation of the promoter suppresses gene expression, but the functional role of gene-body DNA methylation in highly expressed genes has yet to be clarified. To better characterise the methylation of promoter and gene-body, a comprehensive analysis of methylated genes and unmethylated genes in gene-body and upstream2k was performed. In total, 14,018 genes were methylated in both promoter and gene-body, while 505 genes were exclusively methylated in promoter and 409 genes were exclusively methylated in gene-body, and 231 genes unmethylated in both promoter and gene-body (fig. 4A). Gene ontology analysis of methylated and unmethylated genes revealed the top-ranked enriched GO terms were related to the cellular process, metabolic process, and response to stimulus in the biological process (BP) category. The cellular component (CC) category mainly comprised genes involved in cell, cell part, and organelle. Within the molecular function (MF) category, binding, catalytic activity, and tr ansporter activity were highly represented (fig. 4B and 3S). In addition, KEGG analysis showed that genebody methylation genes were clustered in the metabolic pathways, protein processing in endoplasmic reticulum, and calcium signaling pathway, while the genebody unmethylation genes were clustered in metabolic pathways, Fc gamma R-mediated phagocytosis, and endocytosis. Moreover, promoter methylation genes were most involved in ubiquitin mediated proteolysis, oocyte meiosis, and melanoma, while , promoter unmethylation genes were most involved in N-Glycan biosynthesis, Glycosylphosphatidylinositol(GPI)-anchor biosynthesis, and Fat digestion and absorption (fig. 5). DNA methylation and gene expression level DNA methylation of promoter generally suppress gene transcription via inducing a compact chromatin structure. We obtained the gene expression profiles of Tibetan chicken from the GEO database. Based on expression levels, all genes were divided into ten groups, from the lowest 10% and to the highest 10%. Furthermore, the genomic regions that 2 kb upstream of the TSS were defined as the proximal promoter, and used the mean methylation as the methylation level of each group. The correlation analysis showed that gene expression level was negatively related to the mean DNA methylation level of the promoter regions (fig. 6A; r=-0.93, pshowed little difference in these ten groups with different expression level (fig. 6B; r=-0.83, p Discussion Genomics technologies have been extensively used to investigate the adaptations of humans, animals and plants to extreme conditions [15, 16]. However, the relationships between the adaptions and the epigenetic modifications that result from extreme environmental exposures remains to be further elucidated. To date, the methylation pattern of Tibetan chicken remains unknown. To improve our understanding of the association between epigenetic modifications andadaptations to hypoxia and high-dose ultraviolet radiation in high-altitude environments, we analyzed whole-genome single-base resolution DNA methylomes by WGBS to provide the genomewide DNA methylation patterns in Tibetan chicken blood and interrogate the potential role of DNA methylation in adaptations to high-altitude environments. Genome-wide DNA methylations of lowland chickens have been researched using MeDIP-seq [17, 18], MBD-Seq [19], and Methyl-MAPS [20], which measure methylation base on immunoprecipitation and restriction enzyme digestion. Compared to WGBS, these technologies generate lower resolution and coverage, and fail to obtain methylation level for CHG and CHH. For example, Only 32 % of CpG coverage was obtained from the study of lowland chicken using Methyl-MAPS [20]. In the other lowland chicken study, the CpG coverage ranges from 83.72 to 91.57 % using MethylC-seq [21]. In the current study, the CpG effective coverage of each chromosome ranges from 86.74% to 97.5%, except for 23.58% CpG coverage of chr17 in Tibet chicken. In lowland chicken, more than 55.69% of cytosines in CG contexts were methylated which is much higher than those in Tibet chicken (51.22%), while the percentage of mCHG and mCHH in Tibet chicken was higher than those in lowland chicken. In addition, 96.24 %, 0.86 % and 2.89 % of all methylcytosines were present in the CG CHG and CHH context, respectively, while the CG methylation in Tibet chicken occupied only 96% of cytosine methylation. Moreover, the base next to methylcytosine of mCHG in lowland chicken had a preference for A, while that in highland chicken prefer to T. All these indicated that the highland environments decrease the global CG methylation levels of chicken, and change the sequence context preferences for methylation, suggesting that the methylation involve in the adaptations of chicken to high-altitude environments. In Tibetan chicken genome, the DNA methylation level rapidly down before the TSS and markedly increased towards the gene body regions and stayed at a plateau until the 3 end of the gene body. These methylation features discovered in this study consistently match with those previously reported in bovine placentas [22]. Similar to the lowland chickengenome, the Tibetan chicken genome has two CG methylation peaks in the internal and last exons, but the difference is that the lowland chicken genome showed a mitigatory methylation level in the genome regions before the TSS [21], suggesting that the long-term hypoxia and UV radiation under high-altitude conditions cause methylation alternation. The promoter plays a crucial role in the regulation of gene transcription and most of the promoter regions are hypomethylated [23], while the gene-body DNA methylation is associated with chromatin structure and elongation efficiency, and prevents spurious transcription initiation [24, 25]. In present study, we found the promoter is hypomethylated, whereas the methylation level in gene-body is relatively high, a finding that is similar to those from previously reported in human [26] and lowland chicken [17]. Hypermethylation of the promoters represses gene transcription [27], and the reduction of methylation at the promoters causes gene overexpression [28]. In human embryonic stem cells, Laurent et al. reported that 20% of the most highly expressed genes displayed the lowest methylation levels in promoter. We analyse the relationship between the methylation and the expression inTibetan chicken, using the method reported in previous studies [17]. Similar to reports in humans [17, 29, 3 0] and lowland chicken [5], DNA methylation level in 2 kb upstream of genes is negatively related to the gene expression level in Tibetan chicken, this was further evidence that DNA methylation at the promoters is involved in gene silencing. Methylation in gene-body is more prevalent than in promoter, but the role of gene-body methylation in gene regulation remains unclear. Previous researchs showed that gene-body methylation has an intricate correlation with expression level. Most researchers believed that the methylation of gene-body is positively correlated with gene expression [26, 29, 31, 32], although several researchers have indicated that intragenic methylation might inhibit gene transcription [24]. However, the correlation between gene-body methylation and expression levels in bovine placentas is non-monotonic and the moderately expressed genes show the highest methylation in gene-body [22]. Our data demonstrated that methylation in the gene-body of Tibetan chicken may decrease gene expression. However, methylation in gene-body is just one of the thousands of factors that affect gene transcription. Therefore, further studies centering on the DNA methylation of certain regions that display distinct effect in gene regulation are needed to clarify the complicated epigenetic mechanism underlying high-altitude environments and its relationships with adaptations to hypoxia and high-dose ultraviolet radiation in high-altitude environments. In summary, the present study provides the first comprehensive analysis of genome-wide DNA methylation patterns in the blood of highland chicken, and our results can be used for future studies on epigenetic gene regulation in highland chicken. This study contributes to the knowledge on epigenetics in highland animals. References 1. Tirado-Magallanes, R., et al., Whole genome DNA methylation: beyond genes silencing. Oncotarget, 2017. 8(3): p. 5629-5637. 2. Li, S., et al., Genome-wide analysis reveals that exon methylation facilitates its selective usage in the human transcriptome. Brief Bioinform, 2017. 3. Keown, C.L., et al., Allele-specific non-CG DNA methylation marks domains of active chromatin in female mouse brain. Proc Natl Acad Sci U S A, 2017. 4. Daxinger, L. and E. Whitelaw, Transgenerational epigenetic inheritance: more questions than answers. Genome Res, 2010. 20(12): p. 1623-8. 5. Chen, Z.J., Genetic and epigenetic mechanisms for gene expression and phenotypic variation in plant polyploids. Annu Rev Plant Biol, 2007. 58: p. 377-406. 6. De Prins, S., et al., Influence of ambient air pollution on global DNA methylation in healthy adults: a seasonal follow-up. Environ Int, 2013. 59: p. 418-24. 7. Bollati, V., et al., Changes in DNA methylation patterns in subjects exposed to low-dose benzene. Cancer Res, 2007. 67(3): p. 876-80. 8. Xing, C., et al., Methylation and expression analysis of tumor suppressor genes p15 and p16 in benzene poisoning. Chem Biol Interact, 2010. 184(1-2): p. 306-9. 9. Kim, K.Y., et al., Association of low-dose exposure to persistent organic pollutants with global DNA hypomethylation in healthy Koreans. Environ Health Perspect, 2010. 118(3): p. 370-4. 10. Pilsner, J.R., et al., Influence of prenatal lead exposure on genomic methylation of cord blood DNA. Environ Health Perspect, 2009. 117(9): p. 1466-71. 11. Crews, D., et al., Transgenerational epigenetic imprints on mate preference. Proc Natl Acad Sci U S A, 2007. 104(14): p. 5942-6. 12. Srivastava, S., et al., Association of polymorphisms in angiotensin and aldosterone synthase genes of the renin-angiotensin-aldosterone system with high-altitude pulmonary edema. J Renin Angiotensin Aldosterone Syst, 2012. 13(1): p. 155-60. 13. Li, M. and C. Zhao, Study on Tibetan Chicken embryonic adaptability to chronic hypoxia by revealing differential gene expression in heart tissue. Sci China C Life Sci, 2009. 52(3): p. 284-95. 14. Li, R., et al., SOAP2: an improved ultrafast tool for short read alignment. Bioinformatics, 2009. 25(15): p. 1966-7. 15. Turner, T.L., et al., Population resequencing reveals local adaptation of Arabidopsis lyrata to serpentine soils. Nat Genet, 2010. 42(3): p. 260-3. 16. Liu, S., et al., Population genomics reveal recent speciation and rapid evolutionary adaptation in polar bears. Cell, 2014. 157(4): p. 785-94. 17. Li, Q., et al., Genome-wide mapping of DNA methylation in chicken. PLoS One, 2011. 6(5): p. e19428. 18. Hu, Y., et al., Comparison of the genome-wide DNA methylation profiles between fast-growing and slow-growing broilers. PLoS One, 2013. 8(2): p. e56411. 19. Carrillo, J.A., et al., Methylome Analysis in Chickens Immunized with Infectious Laryngotracheitis Vaccine. PLoS One, 2015. 10(6): p. e0100476. 20. Tian, F., et al., DNMT gene expression and methylome in Mareks disease resistant and susceptible chickens prior to and following infection by MDV. Epigenetics, 2013. 8(4): p. 431-44.

Yi Dynasty :: essays research papers fc

서영준  Ã‚  Ã‚  Ã‚  Ã‚  aka Eddie Sanchez The Yi Dynasty   Ã‚  Ã‚  Ã‚  Ã‚  The Yi Dynasty, also called the Chosun Dynasty, is the last and longest-lived imperial dynasty of Korea. General 이성계 founded the Yi Dynasty when he overthrew the Koryo dynasty. It lasted until 1910 when Korea ceased to be an independent sovereign state after being annexed by Japan. During the Chosun Dynasty, Korea’s class system was very defined and social mobility was defined. Primarily, one could theoretically go up through Chosun’s education system, which was Confucian based. Commerce was controlled by the government, but as time went on, government loosened its grip over trading and commerce.   Ã‚  Ã‚  Ã‚  Ã‚  In 1392, General 이성계, or King 태조 as he was later known, became ruler of Korea. Confucian replaced Buddhism as the main ideological influence, and a rigidly structured, hierarchical social system evolved, dominating the kingdom for five centuries (Washam). These measures effectively undercut the societal influence of both Koryo’s Buddhist hierarchy and the old aristocracy. This cleared the way for the new elite class that would dominate Korea for the next 500 years   Ã‚  Ã‚  Ã‚  Ã‚  Great landowners and a Confucianist scholar-gentry, known 양반, dominated agriculture, politics, and foreign policy. The 양반 was comprised of the literati, or educated, class. They monopolized civil and military posts in the new national bureaucracy. The primary way into the bureaucracy was to be successful in the civil service examinations. Since 양반 families were exempt from taxes and labor, they were able to fully devote their time to studying while those who were not born into 양반 families generally did not move up in the social structure due to the fact that they needed to work to survive and pay taxes. Thus, social mobility was difficult and extremely uncommon. However, theoretically and ideally, one could escape the lower classes through mastering the civil service examination.   Ã‚  Ã‚  Ã‚  Ã‚  Beneath them were the crafts people and artists who were highly esteemed because of their skills and talents. Astronomers and physicians were also included in this group. During the Yi Dynasty, Korean landscape painting becomes popular. Also, the Korean ceramics industry is renewed. Craftsmen begin producing white porcelain as well as 분청자기. Craftsmen manufactured many 분청 ceramic pieces for the government as well as for artistic purposes. Porcelain, on the other hand, was basically centralized. Porcelain was managed by the royal court. Perhaps, that is why the craftsmen were highly regarded (Lee).   Ã‚  Ã‚  Ã‚  Ã‚  Below the craftspeople in the official order were the common people who made up 75 percent of the population.

How is happiness conveyed in Jane Austen’s Emma and Charlotte Bronte’s Villette?

The nineteenth century was an era of great discovery, invention and social change as a result of political unrest in the previous years. The American Revolution which culminated in the United States Declaration of Independence, lead to a change in political thought, bringing ideas of ‘Life, Liberty and the Pursuit of Happiness' (1776: line4), though how much this extended to women is debateable. Published thirty-seven years apart, Emma and Villette tell the stories of two girls trying to find happiness in difficult societies. The two lead characters are very different; Emma is a respected, wealthy and attractive young woman yet rather spoilt, whereas Lucy Snowe is passive and secretive, with no significant amount of money or family connections. Living in the same century, therefore, it would seem safe to assume that the girls would find happiness in the same things; good company, money and a happy marriage. As Philip Davis argues, Victorian novels (though Emma predates Victoria's reign by approximately twenty years) were concerned only with ‘Humanity, Duty, Vocation, Work, Marriage [and] Family' (2002:2). However, this is not the case for either of the girls. Lucy finds comfort in solitude and some of the passages in Bronte's novel where she is most at ease are those in which she is alone. If not alone, Lucy prefers the company of just one or two trusted friends, but even this is problematical, as she often hides her feelings from the reader. Emma on the other hand, appears to take pleasure in helping others to be happy; often to their detriment! What can be said, nonetheless, is that both novels convey moral journeys towards a greater understanding of self and society. By looking at a few specific incidents in each novel, the methods with which the authors explore the feeling of happiness can be uncovered. Emma Woodhouse, handsome, clever, and rich, with a comfortable home and happy disposition, seemed to unite some of the best blessings of existence; and had lived nearly twenty-one years in the world with very little to distress or vex her (Emma p. 5). The opening sentence of Jane Austen's novel manages to summarise Emma's situation and history in a few simple words. The reader is already informed by the omniscient narrator that this central character is content and privileged in every aspect that a young lady could wish for. In comparison, Villette has a very different approach. For example, it is not until the second chapter that we find out the name of the protagonist and narrator, Lucy Snowe. Interesting to note also that the first two chapters are names of characters, ‘Bretton' and ‘Paulina', as if the narrator is happy to talk about them, but reluctant to talk about herself. We hear about the people surrounding the narrator, events in the past but very little physical or characteristic detail. We are given few clues as to how Lucy feels or thinks about these events; ‘well I liked the visit' (Villette p. 1) is the only indication of preference or opinion. Even by the end of the novel we do not know where her ‘home' was, and Lucy is constantly evasive about places and locations. The reader is left to speculate why this is; because of unhappiness there and desire to forget it? Or perhaps she is ashamed? It is almost as if she does not trust the reader and as a result becomes difficult to like. Most readers will assume that this past, of which Lucy is so vague, holds bad memories or experiences which set the tone of her character from the start. As a narrator, Lucy is unreliable and the revelation that Dr. John and Graham Bretton are, in fact, the same people, is the prime example of this. ‘I first recognized him on that occasion, noted several chapters back, when my unguardedly-fixed attention had drawn me on the mortification of an implied rebuke' (Villette p. 70-1). Only when the reader will find out for themselves, does Lucy tell us that she knew all along. ‘I had preferred to keep the matter to myself' she reasons, ‘I liked entering his presence covered with a cloud he had not seen through' (Villette p. 171). This motif of hiding, or being screened, recurs throughout the novel. Lucy is often seen observing or people watching, preferring to be out of the limelig ht. However, this changes when she is recruited to be in M. Paul's play after one of the lead characters falls ill. Nevertheless, she puts on a performance, a mask, and is not herself. The clothes she wears are men's and by speaking another person's lines, Lucy distances herself from that which makes her feel so uncomfortable, her own feelings. It seems as if she is afraid to admit to herself how she feels. By suppressing her emotions and living an almost muted life, Lucy denies herself happiness. This alienation is heightened by her being in Belgium, where she does not speak French initially, by being a Protestant in a Catholic society and through the atmosphere of the Mme. Beck's school. Despite working very closely with the headmistress, Lucy still finds her searching through her belongings one evening, showing a lack of trust between the characters. Lucy's narrative style shows a lot about her unhappiness as a character and surprisingly Emma shares some of these traits. Emma is told through a third-person omniscient narrator, whereas Lucy tells us the story through her own, if somewhat limited perspective. Austen's narrator gives us a wider outlook on the events at Highbury, although the free-indirect style means that the narrator's opinions are sometimes blurred with those of the characters and there is some mimicry of Emma's thoughts and tone. She is a more open character, whom the narrator can easily display to the reader, and her feelings are more easily accessible, on first impression. As Emma is already ‘handsome, clever and rich' (Emma p. 1), her happiness is taken for granted, but looking a little deeper it is evident that she is not fully content. The novel is based around a series of shocks for Emma; Miss Taylor's marriage, Mr. Elton's proposal, Frank and Jane's engagement, and she seems in a constant struggle to maintain a certain decorum and propriety. It is ironic that Jane Austen's novels are so often seen as portrayals of a stagnant society, when Highbury is full of entrances and exits; Mrs. Elton, Frank Churchill, Jane Fairfax and Harriet. The proximity to London, peculiarly, does not seem to have an effect on the community. Emma's constant need to help others could be interpreted as dissatisfaction within herself. Instead of realising her feelings for Mr. Knightly at the beginning of the novel, as so easily could have occurred, Emma goes through systematic pairing up of her acquaintances, to try and arrange as many couples as possible. It is only when Harriet confides in her regarding her own feelings for Knightly that Emma is forced to identify and realise her attachment to him. Because she demands a kind of variety and excitement life cannot supply, Emma allows her fancy and imagination to shape and distort her perception of reality [†¦. What Emma constantly desires and frequently demands is not simply that her world admire her; it must also be as rich and vital and beautiful as she feels herself potentially to be [†¦. ] The crux of the matter, then, is the peculiar way in which Emma's life depends upon and is dedicated to richness and beauty in human experience. (Minter 1966 : 51) Minter argues that Emma relies on this constant application of herself to try and adapt her surroundings to suit her. In doing this, Emma is attempting to create an environment in which she is truly comfortable; not a trait one would associate with a young lady of ‘happy disposition' (Emma p. ), but more with slightly nervous and compulsive behaviour. It is as if Emma must have control of the events around her to feel content. This shows a certain extent of self-consciousness and dissatisfaction, reflected most clearly in her thoughts of Jane Fairfax: Why she did not like Jane Fairfax might be a difficult question to answer; Mr Knightly had once told her it was because she saw in her the really accomplished young woman, which she wanted to be thought herself. (Emma p. 125) View in this manner, Emma becomes, in essence, a structured action in which Jane Austen renders both the nobility and the dangers, the significance and the consequences of Emma's endeavour to force an aesthetic ideal upon her world' (Minter 1966 : 51). As a character, Lucy Snowe is built up in a different way by Charlotte Bronte than Emma is by Jane Austen. By looking at their happiest and lowest points in each text, the reader has an insight into their extremes of emotion, and how these are created by the authors. Lucy characterises her weakest moments by images of storms and tempests. This occurs several times throughout the novel and blurs the situations which Lucy does not want the reader to know or understand fully, perhaps because she does not understand herself. This is first seen upon Lucy's departure from Bretton; ‘I must have somehow fallen overboard, or that there must have been wreck at last' (Villette p. 30). It is not certain whether Lucy actually embarks on a boat journey or whether she just uses this as an extended metaphor. Bronte adds the scream of the Banshee to symbolise the coming of bad news; Miss Marchmont dies and leaves Lucy with little money. However, the worst for Lucy personally is arguably the fall ‘headlong down an abyss' (Villette p. 160) after her visit to the church. She has been ill for a long while and her soul leaves her body ‘hoping to leave for rest (Villette p. 160). The reunion of the two is a particularly painful image, ‘a sort of racking struggle', ‘with pain, with reluctance' (Villette p. 161). Villette's final chapter is the most ambiguous sequence of the whole text, in which Lucy almost leaves the conclusion of the novel down to the reader. ‘Reader, they were the three happiest years of my life. Do you scout the paradox? Listen' (Villette p. 488), she appeals to us. Whether M. Paul is killed in a tempest on his return is not overtly stated, though the image of the storm again would imply that he does. If the past three years ‘were' the happiest, then it follows that these are now unhappy times. As with the beginning of the novel, Lucy finishes by telling us what happened to other characters, but not herself; ‘Madame Beck prospered all the days of her life; so did Pire Silas; Madame Walravens fulfilled her ninetieth year before she died. Farewell' (Villette p. 491). With a similar style of description and attitude, it is as if Lucy Snowe has come full circle; she is just as happy at the end of the novel, as at the start, or there seems no noticeable difference. Victor Hugo wrote in Les Miserables that ‘life's greatest happiness is to be convinced we are loved' (1862) and it is this sentiment that gives Lucy the highest moment in Villette. She says that her love for M. Paul ‘gave me such pleasure as, certainly, I had ever felt' (Villette p. 403). Emma's happiest moment comes with similar thoughts on Mr. Knightley, but also a revelation about herself and her own actions; ‘How long had Mr. Knightley been so dear to her, as every feeling now declared him now to be? When had his influence, such influence begun? ‘ (Emma p. 312). This sequence comes with a long set of rhetorical questions in which Emma begins to see her flaws; perhaps this is the ultimate happiness for her? Mahatma Ghandi is often famously quoted as saying, ‘Happiness is when what you think, what you say and what you do are in harmony'1 and this can be seen clearly in the closing chapters of Emma. Finally Emma is settled in herself; knows how she feels, is able to talk openly and does, of course, eventually marry Mr. Knightley. What totally different feelings did Emma take back into the house from what she had brought out! – she had then been only daring to hope for a little respite of suffering; – now in an exquisite flutter of happiness – and such happiness, moreover, as she believed must still be greater when the flutter should have passed away. (Emma p. 328) Emma's reaction is markedly different from Lucy's. Her language is more descriptive and appears fast, almost as if she cannot keep up with what her mind is thinking. The narrator here sounds just like the character of Emma, speaking rapidly with the use of many exclamation marks. Lucy falters, questions M. Paul's affections and seems unsure of the situation. ‘I was content', she states (Villette p. 403) compared to Emma's ‘state of spirits' (Emma p. 328). Emma's unfeeling comments to Miss Bates at the picnic however, paint her in a very different light; ‘†Ah! Ma'am, but there may be a difficulty. Pardon me – but you will be limited as to a number – only three at once†Ã¢â‚¬Ëœ (Emma p. 280). This can be seen as Emma's most unkind and lowest moment in the text, ‘she had never been so depressed' (Emma p. 284) it is a necessary addition that makes her realise how badly she has behaved, although requiring a little help from Mr. Knightley. Throughout Emma and Villette, Austen and Bronte shape their main characters with the use of these dramatic highs and lows, which alter their perceptions and also the reader's perceptions of them. By using specifically chosen language, the feelings and emotions of Lucy Snowe and Emma Woodhouse are made apparent and so the reader can share in their delight and depression. Jane Austen's novel appears overall a happier text, despite the continual failings of Emma's matchmaking, and ends positively with both Emma and Harriet getting married, and Harriet discovering her parentage. Although their marriages are well paired, with men who will complete them, the reader cannot help questioning whether marriage and money will always create ‘perfect happiness' (Emma p. 367). Villette on the other hand, ends just as mournfully as it begins, with very little defined ending. It could be argued that Lucy Snowe finds an inner peace with herself, after enjoying three happy years, despite not having M. Paul with her. Perhaps knowing she is loved is enough, and so with this and the solitary life which has given her comfort throughout the novel, Lucy can be settled. With her flourishing school as financial security, Lucy does not require anything more; she has stability and security, that which she has lacked from a young age. Though the storm imagery, if consistent with the rest of Bronte's novel, indicates further change, we are not given any clues as to how this will transpire. With so many novels of this era, both Emma and Villette look at the difficulty of a woman finding true happiness in such a patriarchal society. Kate Millett argued that Villette was ‘too subversive to be popular' (1977:140), accurate considering the conformity of many novels of the time. Emma, for example, still allows a happy ending and a marriage, despite the main character's actions throughout. In creating this alternative style, Charlotte Bronte shows happiness through a perhaps more realistic perspective, rather than Austen's romanticised, ‘happily-ever-after' story.

My Favorite Hobby

Wind blowing into my face, my eyes where after few seconds the tears come out and I am speeding and crying but this are not the tears of sadness but the tears of joy. Stop. Here I am in the most beautiful place in the world, surrounded by mountains covered in snow. Sun is shining, even though it’s minus ten but I haven’t even noticed because I’m too happy. I have the feeling of being on top of the world and that there’s nothing that can stop me. It’s great to have a passion that makes you feel like this. I’m lucky to have one.During the time that most of people like to spend drinking warm tea and reading a novel, I’m cruising through snow, both my legs strapped to a wide plank of wood and fiberglass, practicing sport known as snowboarding. Writing this essay helped me to realize that I haven’t chosen this hobby by a coincidence. Both of the characteristics of this sport changed the world history. Events like the French revolutio n of 1789 or the uprising in the Jewish ghetto in Warsaw in 1943, would not have happened if people hadn’t had courage and belief in freedom.Courage. Many people who know me well say, that I have courage. I come from a family of entrepreneurs. I was raised in this spirit by my entrepreneurial parents who had big respect for hard work. I learned that hard work will always be rewarded. I helped in my family’s business, since I turned 14 and I learned the pros and cons of having your own business. Even though the disadvantages seemed big to me at that time, as an only child I knew that I would run the business one day. By the time I turned 18, I was fully at peace with this idea.It’s hard to imagine how big my shock was when one year later my father got a brain cancer and passed away and a year later our self-built family company. The shock was big and lasted long but I knew one thing – I had no plan and I needed one. I put myself together and made a new pla n – studying, developing myself, investing in what my father used to say â€Å"nobody will ever be able to take away from you† which is knowledge. Where I am today, doing what I do is the result of that experience and my patience, persistence and hard work. Freedom.During an exchange programme for students, we played a game in which each of us had to choose 3 words representing our values. Surprisingly I had no problem to choose the number one â€Å"freedom†. I found that amazing to discover, that freedom was more important to me than things like â€Å"family†, which was the number two, â€Å"love†, not to mention – â€Å"career† or â€Å"development†. Even today I know that only through â€Å"freedom† can I achieve all the other values that are important to me. It organizes my priorities and my moral system. It’s the freedom of my own choices and the freedom of always standing for what I believe in.Moreover, it i s also about honesty and respect to other people, which are my personal code of conduct. And when necessary it is the freedom to give up some of our freedom out of love and respect for others. Courage and all the notions of freedom described above are helping me to be successful in business. I am always a promoter of honesty and transparency in the workplace, as well a big supporter of the sustainable development agenda. What makes it different but not less exiting than my sport activities, is the fact that I don’t have to do it in minus ten degrees Celsius†¦

Interesting Gadolinium Element Facts

Interesting Gadolinium Element Facts Gadolinium is one of the light rare earth elements belonging to the lanthanide series. Here are some interesting facts about this metal: Gadolinium is silvery, malleable, ductile metal with a metallic sheen. It is fluorescent and tends to have a faintly yellowish tint.Gadolinium, like other rare earths, is not found in pure form in nature. The primary source of the element is the mineral gadolinite. It is also found in other rare earth ores, such as monazite and bastnasite.At low temperatures, gadolinium is more ferromagnetic than iron.Gadolinium has superconductive properties.Gadolinium is magnetocaloric, which means its temperature increases when it is placed in a magnetic field and decreases when it is removed from the field.Lecoq de Boisbaudran separated gadolinium from its oxide in 1886. He named the element for  Finnish Chemist Johan Gadolin, the discoverer of the first rare earth element.French chemist and engineer  Felix Trombe was the first to purify gadolinium in 1935.Gadolinium has the highest thermal neutron cross section of all the elements.Gadolinium is used in nuclear reactor control rods to regular fission. The element is injected into MRI patients to increase image contrast.Other uses of gadolinium include manufacture of certain iron and chromium alloys, computer chips and CDs, microwave ovens, and televisions.The pure metal is fairly stable in air, but tarnishes in moist air. It slowly reacts in water and dissolves in dilute acid. At high temperatures, gadolinium reacts with oxygen. Gadolinium Chemical and Physical Properties Element Name: GadoliniumAtomic Number: 64Symbol: GdAtomic Weight: 157.25Discovery: Jean de Marignac 1880 (Switzerland)Electron Configuration: [Xe] 4f7 5d1 6s2Element Classification: Rare Earth (Lanthanide)Word Origin: Named after the mineral gadolinite.Density (g/cc): 7.900Melting Point (K): 1586Boiling Point (K): 3539Appearance: soft, ductile, silvery-white metalAtomic Radius (pm): 179Atomic Volume (cc/mol): 19.9Covalent Radius (pm): 161Ionic Radius: 93.8 (3e)Specific Heat (20 °C J/g mol): 0.230Evaporation Heat (kJ/mol): 398Pauling Negativity Number: 1.20First Ionizing Energy (kJ/mol): 594.2Oxidation States: 3Lattice Structure: HexagonalLattice Constant (Ã…): 3.640Lattice C/A Ratio: 1.588 References Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Langes Handbook of Chemistry (1952), CRC Handbook of Chemistry Physics (18th Ed.)

Biography of Paul Revere and His Midnight Ride

Biography of Paul Revere and His Midnight Ride Paul Revere (January 1, 1735–May 10, 1818) is perhaps best known for his famous midnight ride, but he was also one of Boston’s most ardent patriots. He organized an intelligence network called Sons of Liberty to help colonists fight against British troops. Fast Facts: Paul Revere Known for: Famous midnight ride alerting the people of Lexington and Concord of an impending British attack; one of the leaders of Sons of Liberty movementOccupation: Silversmith, artisan, and early industrialistBorn:  January 1, 1735 in Boston, MassachusettsDied:  May 10, 1818, Boston, MassachusettsParents’ Names: Apollos Rivoire and Deborah HitchbornSpouses Names: Sarah Orne (m. 1757-1773); Rachel Walker (m. 1773-1813)Children: 16, 11 of whom survived childhood Early Years Paul Revere was the third of twelve children born to Apollos Rivoire, a French Huguenot silversmith, and Deborah Hitchborn, the daughter of a Boston shipping family. Apollos, who emigrated from France as a teen, changed his name to the more English-sounding Revere at some point prior to Pauls birth- a common practice at the time. The young Revere left school in his early teens to become an apprentice in his fathers silversmithing business, which allowed him to interact with a wide variety of different people within Bostons society. When Revere was nineteen, his father died, but he was too young to take over the smithy, so he enlisted in the provincial army. The French and Indian War was ongoing, and Revere soon found himself commissioned to the rank of Second Lieutenant. After a year in the Army, Revere returned home to Boston, took over the family silver shop, and married his first wife, Sarah Orne. By the mid-1760s, the economy was sliding into a recession, and Reveres silver business was struggling. Like many craftsman of the era, Revere needed some supplemental income, so he took up the practice of dentistry. His skill in manufacturing false teeth from ivory was one that would serve him well later. The Brink of Revolution In the late 1760s, Revere formed a close friendship with Dr. Joseph Warren of Boston. The two men were members of the Masons, and they each had an interest in politics. Over the next few years, they became active participants in the Sons of Liberty movement, and Revere used his skill as an artist and craftsman to produce some of Americas earliest political propaganda. He illustrated carvings and engravings, many of which included images of events like the Boston Massacre of 1770, and a parade of British troops through the citys streets. As he became more prosperous, Revere and his family moved to a home in Bostons North End. However, in 1773, Sarah died, leaving Revere with eight children to raise; within a few months he married his second wife, Rachel, who was eleven years his junior. In November of that year, a ship called the Dartmouth docked in Boston Harbor, and history would soon be made. The Dartmouth arrived laden with tea shipped by the East India Company under the newly-passed Tea Act, which essentially was designed to force colonists to buy tea from East India, rather than purchasing smuggled tea at a lower cost. This was extremely unpopular with the people of Boston, so Revere and many of the men of the Sons of Liberty took turns guarding the ship, preventing it from being unloaded. On the night of December 16, Revere was one of the ringleaders when American patriots stormed the Dartmouth and two other East India ships, and dumped the tea into Boston Harbor. Over the next two years, Revere made regular rides as a courier, traveling from Boston to Philadelphia and New York City to carry information on behalf of the Committee of Public Safety. This was a grass-roots committee of patriots who did their best to make governing extremely difficult for British authorities. Around the same time, Revere and other members of the Sons of Liberty, and their associates, began a network of intelligence gathering in Boston. Meeting in a tavern called the Green Dragon, which Daniel Webster called the headquarters of the revolution, Revere and other men, known as Mechanics, disseminated information about the movement of British troops. The Midnight Ride In April 1775, Dr. Joseph Warren was alerted to possible British troop movements near Concord, Massachusetts. Concord was a small town not far from Boston, and was the site of a large cache of patriot military supplies. Warren sent Revere to warn the Massachusetts Provincial Congress so they could move the stores to a safer location. Interim Archives / Getty Images A few days later, British General Thomas Gage was ordered to move on Concord, disarm the patriots, and seize their cache of weapons and supplies. Although Gage was instructed by his superiors to arrest men like Samuel Adams and John Hancock for their roles as rebel leaders, he opted not to include that in his written instructions to his troops, because if word got out, there could be a violent uprising. Instead, Gage chose to focus his written orders on taking possession of the weapons he believed to be housed in Concord. Over the coming days, Revere instructed the sexton at the North Church to use a signal lantern in the steeple if he saw British soldiers approaching. Because the British could either take the road from Boston to Lexington or sail up the Charles River, the sexton was told to light a single lantern for land movement, and two if there was activity on the water. Thus, the phrase one if by land, two if by sea was born. On April 18, Warren told Revere that reports indicated that British troops were secretly moving towards Concord and the neighboring town of Lexington, ostensibly to capture Adams and Hancock. Although the weapons supply had been safely moved, Hancock and Adams were unaware of the impending danger. When the sexton at the North Church placed two lanterns in his steeple, Revere moved into action. He crossed the Charles River in a rowboat in the dead of night, careful to avoid the notice of the British warship HMS Somerset, and landed in Charlestown. From there, he borrowed a horse and rode to Lexington, sneaking past British patrols and alerting every home he passed along the way. Revere traveled through the night, visiting patriot strongholds like Somerville and Arlington, where additional riders picked up the message and traveled their own routes. By the end of the night, it is estimated that some forty riders had gone out to spread the word of the impending British attack. Revere arrived in Lexington around midnight, and warned Adams and Hancock, and then headed towards Concord. On his way, he was stopped by a British patrol and questioned; he told the soldiers that if they approached Lexington they would find themselves face to face with an angry and armed militia. At some point, once they neared Lexington with Revere in tow, the towns church bell began to ring; Revere told them it was a call to arms, and the soldiers left him in the woods to walk the rest of the way to town alone. Once he arrived, he met up with Hancock, and helped him gather up his family so they could escape safely as the battle on Lexington Green began. During the Revolutionary War, Revere was unable to return to Boston, but stayed in Watertown, where he continued his work as a courier for the provincial congress, and printed currency for payment of the local militias. Dr. Warren was killed at the Battle of Bunker Hill, and nine months after his death, Revere was able to identify his remains, exhumed from a mass grave, thanks to a false tooth he had mounted for his friend, making Paul Revere the first forensic dentist. There is no evidence that Revere actually shouted out The British are coming! during his famous ride. Later Years After the Revolution, Revere expanded his silversmithing business and opened an iron foundry in Boston. His business produced cast iron goods such as nails, weights, and tools. Because he was willing to invest money into expanding his foundry, and embraced new technological ideas in the field of metalworking, he became highly successful. Eventually, his foundry moved into iron and bronze casting, and he was able to mass produce church bells as America moved into a post-war religious revival. With two of his sons, Paul Jr. and Joseph Warren Revere, he founded Paul Revere and Sons, and gradually perfected the production of rolled copper. He remained politically active throughout his entire life, and died in 1818 at his home in Boston. Sources â€Å"Joseph Warren Dies a Martyr in the Battle of Bunker Hill.† New England Historical Society, 16 June 2018, www.newenglandhistoricalsociety.com/death-gen-joseph-warren/.Klein, Christopher. â€Å"The Real-Life Haunts of the Sons of Liberty.† History.com, AE Television Networks, www.history.com/news/the-real-life-haunts-of-the-sons-of-liberty.â€Å"Paul Revere - The Midnight Ride.† Paul Revere House, www.paulreverehouse.org/the-real-story/.Strangeremains. â€Å"Paul Revere: The First American Forensic Dentist.† Strange Remains, 11 Oct. 2017, strangeremains.com/2017/07/04/paul-revere-the-first-american-forensic-dentist/.

The Invention of Paper

The Invention of Paper Try to imagine life without paper. Even in the era of emails and digital books, paper is all around us. Paper is in shopping bags, money, store receipts, cereal boxes, and toilet paper. We use paper in so many ways every day. So, where did this marvelously versatile material come from? According to ancient Chinese historical sources, a court eunuch named Tsai Lun (or Cai Lun) presented the newly-invented paper to the Emperor Hedi of the Eastern Han Dynasty in 105 CE. The historian Fan Hua (398-445 CE) recorded this version of events, but archaeological finds from western China and Tibet suggest that paper was invented centuries earlier. Samples of even more ancient paper, some of it dating to c. 200 BCE, have been unearthed in the ancient Silk Road cities of Dunhuang and Khotan, and in Tibet. The dry climate in these places allowed the paper to survive for up to 2,000 years without entirely decomposing. Amazingly, some of this paper even has ink marks on it, proving that ink was invented much earlier than historians had supposed. Writing Materials Before  Paper Of course, people in various places around the world were writing long before the invention of paper. Materials such as bark, silk, wood, and leather functioned in a similar way to paper, although they were either much more expensive or heavier. In China, many early works were recorded on long bamboo strips, which were then bound with leather straps or string into books. People world-wide also carved very important notations into stone or bone, or pressed stamps into wet clay and then dried or fired the tablets to preserve their words. However, writing (and later printing) required a material that was both cheap and lightweight to become truly ubiquitous. Paper fit the bill perfectly. Chinese Paper-Making Early paper-makers in China used hemp fibers, which were soaked in water and pounded with a large wooden mallet. The resulting slurry was then poured over a horizontal mold; loosely-woven cloth stretched over a framework of bamboo allowed the water to drip out the bottom or evaporate, leaving behind a flat sheet of dry hemp-fiber paper. Over time, paper-makers began to use other materials in their product, including bamboo, mulberry and different types of tree bark. They dyed paper for official records with a yellow substance, the imperial color, which had the added benefit of repelling insects that might have destroyed the paper otherwise. One of the most common formats for early paper was the scroll. A few long pieces of paper were pasted together to form a strip, which was then wrapped around a wooden roller. The other end of the paper was attached to a thin wooden dowel, with a piece of silk cord in the middle to tie the scroll shut. The Spread of Paper-Making From its point of origin in China, the idea and technology of paper-making spread throughout Asia. In the 500s CE, artisans on the Korean Peninsula began to make paper using many of the same materials as Chinese paper-makers. The Koreans also used rice straw and seaweed, expanding the types of fiber available for paper production. This early adoption of paper fueled the Korean innovations in printing, as well. Metal movable type was invented by 1234 CE on the peninsula. Around 610 CE, according to legend, the Korean Buddhist monk Don-Cho introduced paper-making to the court of Emperor Kotoku in Japan. Paper-making technology also spread west through Tibet and then south into India. Paper Reaches the Middle East and Europe In 751 CE, the armies of Tang China and the ever-expanding Arab Abbasid Empire clashed in the Battle of Talas River, in what is now Kyrgyzstan. One of the most interesting repercussions of this Arab victory was that the Abbasids captured Chinese artisans, including master paper-makers like Tou Houan, and took them back to the Middle East. At that time, the Abbasid Empire stretched from Spain and Portugal in the west through North Africa to Central Asia in the east, so knowledge of this marvelous new material spread far and wide. Before long, cities from Samarkand (now in Uzbekistan) to Damascus and Cairo had become centers of paper production. In 1120, the Moors established Europes first paper mill at Valencia, Spain (then called Xativa). From there, this Chinese invention passed to Italy, Germany, and other parts of Europe. Paper helped spread knowledge, much of which was gleaned from the great Asian culture centers along the Silk Road, that enabled Europes High Middle Ages. Manifold Uses Meanwhile, in East Asia, paper was used for an enormous number of purposes. Combined with varnish, it became beautiful lacquer-ware storage vessels and furniture. In Japan, the walls of homes were often made of rice-paper. Besides paintings and books, paper was made into fans, umbrellas, even highly effective armor. Paper truly is one of the most wonderful Asian inventions of all time.

Premarital screening Essay Example | Topics and Well Written Essays - 750 words

Premarital screening - Essay Example Most of the technologies applied to provide these challenges are usually applied in; screening, diagnosis as well as information control and management. Cervical cancer is one of the current reproductive health challenge faced by the current generation; science has shown that it a condition caused by tissues that develops around the cervix. Characteristically, this form of cancer develops slowly and may take a longer time to be detected. Other causes of cervical cancer has been identified to occur from the essence of having multiple sexual partners among women, Human papillomavirus (HPV), early age sexual inter course and smoking of cigarettes (cervicalcancer.about.com). To begin with, science has played a major role in provision of solution to this current reproductive system by providing a platform for the scientists to conduct scientific researches geared towards proving solution through; acquisition of imperative information concerning new methodologies of treatment (cervicalcancer.about.com). Additionally, science had played a major role in the context of technology by facilitating the development of screening and treatment methods. The treatment methods are; radiotherapy, chemotherapy together with surgery. These methods may sometimes be used through a combination of one or two of them; however, in most cases, a single treatment method is usually applied to the patients (Yarbro et al 2005, pg.37). Surgical treatment of cancer can be conducted in various ways; the first method applied in the surgical treatment is the removal of the lymph nodes which is scientifically known as lymphadenectomy. The other surgical treatment method is the complete removal of the cervix and the organs around it; the method is scientifically known as radical trachelectomy (World Health Organization 123). The functionality of chemotherapy, involves the killing of cancerous cells by utilization of radiation rays. Chemotherapy drugs are also imperatively used to kill the

(TV)Media Influence on Youth Essay Example | Topics and Well Written Essays - 1000 words

(TV)Media Influence on Youth - Essay Example B. Lower the self-esteem of preteens resulting to lowering self -confidence about their bodies. III. Watching many programs consumes much time for academic work and physical exercises A. Result to poor academic performance. B. Contribute to development of obesity and unhealthy weight gain due to lack of physical exercises. IV. We need to promote watching beneficial programs and encourage parental participation in children activities. A. Censored programs are important source of knowledge and entertainment for preteens. B. Parental involvement in child upbringing protects preteen from being negatively influenced by Television. Media plays an important role by shaping our social, religious, economic and political aspects. In this era of rapid technological advancement, information is flowing at unprecedented rate and though there are many forms of accessing information, television remains one of the most common and influential to all people in the society. Young people especially prete ens and adolescents form a major segment of TV audience and according to Comstock and Paik (1991, p51), television programs have major influence on their behaviors. In United States, the public is concerned over the frequent depiction of violent and sexually explicit programs and the harm that the programs present to the youth. This development comes after many studies have established that such programs adversely affect children on short term and long-term basis (Anderson & Bushman, 2002, p234). This paper expounds on the negative influences of television on preteens and adolescents. According to Comstock and Paik (1991, p59), television programs with violent content enhance immediate and long-term development of aggression and violent behavior on preteens and young adults. The intensity of these behaviors depend on the severity of the violent programs, with Rosenthal (1986, p 143) noting that preteens who watch extremely violent programs have higher likelihood of developing severe forms of aggression. Empirical studies have established that short-term exposure to violent programs increases the likelihood of preteens developing physical and verbal abuse behavior, aggressive emotions and violent thoughts. Many research studies attribute aggression by adults later in life to the effects of frequently exposing children to violent content in the television and other forms of electronic media. These behaviors are manifested in the high prevalence of violent crimes such as aggravated assaults, homicide, physical assaults, domestic and spousal violence in addition to rape among others (Freedman, 2002, p37). Behavioral scientists have developed several theories to explain how exposure to violent or sexually explicit content affects the behavior of the viewer. According to Comstock and Paik (1991, p61), violent programs in the television initiates a short-term effect that increases the existing aggressive cognitions in children and young adults. This results to an inc rease in psychological arousal that triggers an automatic reaction to emulate the observed behavior. Therefore, exposure to violent content produces long lasting effect on the young persons, through several learning processes that lead to acquisition of long-term aggressive behavior. The long-term behaviors include development of aggression supporting beliefs, abnormal response to violent behavior such as; tolerating violence, aggression in social

Reflection essay Example | Topics and Well Written Essays - 500 words - 6

Reflection - Essay Example ry to the popular belief that the Filipino Amerasian children live prosperous lives in the Philippines since the country does not have anti-American sentiment. Whether or not a country nurtures anti-American sentiment provides no guarantee that its citizens would not be discriminated against if they look like Americans. The Filipino Amerasian children are socially outcast as they are identified with their American lineage instead of the Filipino lineage. The government of the US assumes moral responsibility to help the Filipino Amerasian children and provide them with the opportunity to migrate to the US. This can be achieved by preferring them on immigration services. Realization of any plans made in this regard requires joint cooperation of the Filipino people, the local governments of the Philippines, and the government of the US. It is noteworthy that the problem is not addressed just by providing these children with a way to reach the US; these children also need to be linked to their biological American fathers which is another challenge after the children reach the US. In order for the children to sue their fathers for child support, they need to know their fathers. Enforcement of child support is a matter primarily taken care of by state. Unfortunately, most states do not enforce the child-support payments ordered by court effectively. This imparts the need for providing these children with the opportunity to pursue redress at the federal level. It is just as important to address the issue at the source as it is to address it at the level of effects. American soldiers are still stationed overseas. It is important to see what steps the government of the US has taken to ensure that such biracial children with lost American fathers are not born to another nation like they were born to the Filipinos. Either the government should place a ban on the American soldiers having sexual intercourse with the local people or prostitutes of the host countries and

Technology in World Civilization Essay Example | Topics and Well Written Essays - 500 words

Technology in World Civilization - Essay Example The developed overreliance on technology that is predicted to persist therefore means that people are not able to effectively, as they did before, handle tasks manually. This however identifies a critical problem should a global calamity occur and disable all technology-based systems (Fema, 2011). The problem would be similar to the Ireland’s potatoes famine of the nineteenth century. In the case, social conditions had led to reliance of potatoes as the chief food crop. The crop’s disease that broke out in the year 1845 however cut the society’s only source of food, leading to famine. The consequences were fatal with further implications such as â€Å"cholera, dysentery, typhus, and manifestation of lice† that led to death and displacement of people from the region (Digital, 2012, p. 1). The two instances therefore identify similarity in societies that can barely survive, should their staple application fail. Like the potatoes’ plight disrupted people’s social, political, and economic lives in Ireland, disruption in technology will stall professional and industrial operations that have entirely depended on it. Economic processes, healthcare services, and communication will therefore stop. The current society can however slowly adjust to its manual operation system, like in the potatoes’ calamity, or bear the consequences until another technology is developed (Fema, 2011; Digital, 2012). A fault that incapacitates all processor-based applications such as application of computer and computer-based devices would require solutions. One of the possible solutions that the society can use is reverting to the traditional manual operation system, a process that will depend on human resource for decision-making and process implementations. The society would also try to investigate causes of the problem in order to restore the processor applications.

Modern management of Honda Company Research Paper

Modern management of Honda Company - Research Paper Example Honda is the leading global developer of motorcycles and internal combustion engines. It is located in Singapore, Japan. This company became dominant over Nissan in 2001 and gained the position of one of the most successful and largest manufacturers in Japan. In 2008 Honda over passed Chrysler and became the greatest manufacturer in the USA. In the world the Company gains the position of the sixth largest manufacturer of automobile. As far as we can see, the company is a powerful and estimable competitor in the arena of the global automobile industry. In order to advance its positions in the modern world, Honda should increase its sales. Unlike its main competitors, the Detroit Big Three and Toyota, Honda gained a 1% increase of sales in America (The Official Website of Honda). Still, there is a need to focus more on the demands of global markets and take into account advanced needs if the customers all over the world. Two basic pillars of the modern demand of the automobile industry is environmental safety and energy efficiency. Moreover, in accordance with recent statistical data: â€Å"Honda is the largest engine maker in the world, producing nearly 11 million engines annually for its three product lines, including sales of engines to other manufacturers. Honda also builds products in more than 100 manufacturing plants in 33 countries, employing more than 125,000 associates globally† (The Official Website of Honda). The most beneficial strategy chosen by Honda in terms of economical crisis in the world can be illustrated by the Civic and the Accord automobiles. These models of automobiles are of mid-size and there is a high fuel-efficiency of the vehicles. There is also an essential flexibility of the automobiles. Moreover, within the last decade Honda managed to create their factories more flexible and these are able to reshape any Honda model of the automobile at any moment. Global locations of the Company’s plants in such countries as Canada , England, Brazil, Belgium and many others indicate their leading positions of Japanese market and the important role it plays globally (Honda Raffles Trip to Japan to Celebrate 20 Years).   Another benefit of Honda is its acknowledgement by the customers around the globe, because it produces economically friendly automobiles. Moreover, constant innovative developments indicate Honda’s ability to be successful in the global arena. High quality products at a low price- this is one of the main advantages of the company as well, especially in the post-crisis economical period. Environmental factors affecting business Modern automobile industry exists in a challenging global environment. Such factors, as social, political, economic and technological ones should be taken into account by the car producers. On the example of Honda it should be noted that this large car manufacturer is surrounded by preventive environmental factors. Political factors, such as degree of intervention in the economy, are rather influential external factor for automobile industry. There are set customers protection laws, which are focused on the safety of customers’ interests. Moreover, the qualities of the infrastructure of the economy as well as the knowledge of the workforce are determinant factors in the political context of the country. Practices of employment or labor laws are also important for the automobile industry. Workforce protection laws are followed by Honda. Moreover, a tendency for a constant innovations and technological advancement is also reflected by the policies of the Company. Economic Environment of Honda influences development of economically safe and reliable automobiles and engines, which are customer-friendly. Business decisions of Honda are developed with respect to the main concerns of economic factors (Khanfan & Loudon, 2008). There is a strong

Financial Services Essay Example | Topics and Well Written Essays - 3000 words

Financial Services - Essay Example In December 2010, the Basel Committee had come up with a fresh version of its latest standards for bank capital as well as liquidity obligations. This latest set of worldwide regulatory standards for banks is referred to as the Basel III. The core facets of Basel III are planned to be realised as nationwide regulation by the first half of 2013. However, while certain portions of the new Basel principles are supposed to become effectual upon execution, the others would be implemented over a phase of numerous years. The main reason for the development of the Basel III was the deficits in the financial policies of the Basel Accord II that were exposed during the worldwide financial calamity in the year 2008 (Bank for International Settlements, 2011). This paper critically examines the general approach to measuring capital adequacy levels of banks as per the new standards implemented by the Basel III. The paper subsequently discusses the drawbacks of the Basel II standards that were expo sed during the 2008 worldwide financial catastrophe and which consequently led to the development of the Basel III standards. Additionally, the paper also appraises whether the imposition of the Basel III standards for capital adequacy as well as liquidity obligations of bank will be sufficient to prevent a further financial calamity in future. Background to Basel III Various regulatory bodies have recognised that the prevalent strategies of capital regulations of the banks in the United States as well as the European Union, on the basis of the Basel I and the Basel II Accords as a major reason contributing to the 2008 financial disaster (Shearman & Sterling, 2011; Dowd & Et. Al., 2011). This can be substantiated from the fact that under the prevalent... The paper tells that various regulatory bodies have recognised that the prevalent strategies of capital regulations of the banks in the United States as well as the European Union, on the basis of the Basel I and the Basel II Accords as a major reason contributing to the 2008 financial disaster. This can be substantiated from the fact that under the prevalent capital adequacy policies prior to the financial crisis, the least regulatory capital obligations of banks were inadequate. The low capital obligations imposed on the banks as per the Basel II in addition to certain standards linked to the Basel I were deficient in the context of the elevated exposures and real tangible losses endured by the banking entities during the economic downturn. It was also stated that the quality of the capital maintained by the banks as per regulations were time and again found to be inadequate in absorbing the losses sustained by the banks during the economic crisis successfully. The capital adequacy policies set as per the standards of the Basel II along with that of the Basel I, did not sufficiently detain the risks that were caused by bank exposures to certain dealings. The transactions or dealings that increased the exposures of the banks that the regulatory standards failed to capture were securitisations, repurchase agreements and derivatives. The regulatory policies of Basel I and Basel II also failed to effectively take into account the systemic risks related to the upsurge of leverage in the fiscal and monetary system.

Modern management of Honda Company Research Paper

Modern management of Honda Company - Research Paper Example Honda is the leading global developer of motorcycles and internal combustion engines. It is located in Singapore, Japan. This company became dominant over Nissan in 2001 and gained the position of one of the most successful and largest manufacturers in Japan. In 2008 Honda over passed Chrysler and became the greatest manufacturer in the USA. In the world the Company gains the position of the sixth largest manufacturer of automobile. As far as we can see, the company is a powerful and estimable competitor in the arena of the global automobile industry. In order to advance its positions in the modern world, Honda should increase its sales. Unlike its main competitors, the Detroit Big Three and Toyota, Honda gained a 1% increase of sales in America (The Official Website of Honda). Still, there is a need to focus more on the demands of global markets and take into account advanced needs if the customers all over the world. Two basic pillars of the modern demand of the automobile industry is environmental safety and energy efficiency. Moreover, in accordance with recent statistical data: â€Å"Honda is the largest engine maker in the world, producing nearly 11 million engines annually for its three product lines, including sales of engines to other manufacturers. Honda also builds products in more than 100 manufacturing plants in 33 countries, employing more than 125,000 associates globally† (The Official Website of Honda). The most beneficial strategy chosen by Honda in terms of economical crisis in the world can be illustrated by the Civic and the Accord automobiles. These models of automobiles are of mid-size and there is a high fuel-efficiency of the vehicles. There is also an essential flexibility of the automobiles. Moreover, within the last decade Honda managed to create their factories more flexible and these are able to reshape any Honda model of the automobile at any moment. Global locations of the Company’s plants in such countries as Canada , England, Brazil, Belgium and many others indicate their leading positions of Japanese market and the important role it plays globally (Honda Raffles Trip to Japan to Celebrate 20 Years).   Another benefit of Honda is its acknowledgement by the customers around the globe, because it produces economically friendly automobiles. Moreover, constant innovative developments indicate Honda’s ability to be successful in the global arena. High quality products at a low price- this is one of the main advantages of the company as well, especially in the post-crisis economical period. Environmental factors affecting business Modern automobile industry exists in a challenging global environment. Such factors, as social, political, economic and technological ones should be taken into account by the car producers. On the example of Honda it should be noted that this large car manufacturer is surrounded by preventive environmental factors. Political factors, such as degree of intervention in the economy, are rather influential external factor for automobile industry. There are set customers protection laws, which are focused on the safety of customers’ interests. Moreover, the qualities of the infrastructure of the economy as well as the knowledge of the workforce are determinant factors in the political context of the country. Practices of employment or labor laws are also important for the automobile industry. Workforce protection laws are followed by Honda. Moreover, a tendency for a constant innovations and technological advancement is also reflected by the policies of the Company. Economic Environment of Honda influences development of economically safe and reliable automobiles and engines, which are customer-friendly. Business decisions of Honda are developed with respect to the main concerns of economic factors (Khanfan & Loudon, 2008). There is a strong

Assignmen From Readings Essay Example for Free

Assignmen From Readings Essay This document includes ACC 340 Week 2 Assignments from Readings ACC 340 Week 2 Individual Assignments From the Readings Write a response to the following assignment from the Core Concepts of Accounting Information Systems text: Chapter 3: Case Analyses (The Dinteman Company) Format your response consistent with APA guidelines. Business Accounting Accounting Information Systems I ENTIRE COURSE Phoenix University Pick out classes that are challenging and interesting to you instead of the ones that people think are very easy. Giving yourself a challenge is rewarding. You are sure to gain more knowledge from tough courses, and you might make connections that will benefit you later on.

Flip Flop Circuit Explanation and Study

Flip Flop Circuit Explanation and Study A flip-flop is a term referring to an electronic circuit (a bistable multivibrator) that has two stable states and thereby is capable of serving as one bit of memory. Today, the term flip-flop has come to mostly denote non-transparent (clocked or edge-triggered) devices, while the simpler transparent ones are often referred to as latches; however, as this distinction is quite new, the two words are sometimes used interchangeably . A flip-flop is usually controlled by one or two control signals and/or a gate or clock signal. The output often includes the complement as well as the normal output. As flip-flops are implemented electronically, they require power and ground connections. Introduction Basic Flip-Flop Circuit A flip-flop circuit can be constructed from two NAND gates or two NOR gates. Each flip-flop has two outputs, Q and Q, and two inputs, set and reset. This type of flip-flop is referred to as an SR flip-flop or SR latch. The flip-flop in figure has two useful states. When Q=1 and Q=0, it is in the set state (or 1-state). When Q=0 and Q=1, it is in the clear state (or 0-state). The outputs Q and Q are complements of each other and are referred to as the normal and complement outputs, respectively. The binary state of the flip-flop is taken to be the value of the normal output. When a 1 is applied to both the set and reset inputs of the flip-flop in Figure 2, both Q and Q outputs go to 0. This condition violates the fact that both outputs are complements of each other. In normal operation this condition must be avoided by making sure that 1s are not applied to both inputs simultaneously. The NAND basic flip-flop circuit in figure operates with inputs normally at 1 unless the state of the flip-flop has to be changed. A 0 applied momentarily to the set input causes Q to go to 1 and Q to go to 0, putting the flip-flop in the set state. When both inputs go to 0, both outputs go to 1. This condition should be avoided in normal operation. Master-Slave Flip-Flop Introduction A master-slave flip-flop is constructed from two seperate flip-flops. One circuit serves as a master and the other as a slave. The logic diagram of an SR flip-flop is shown in figure.The master flip-flop is enabled on the positive edge of the clock pulse CP and the slave flip-flop is disabled by the inverter. The information at the external R and S inputs is transmitted to the master flip-flop. When the pulse returns to 0, the master flip-flop is disabled and the slave flip-flop is enabled. The slave flip-flop then goes to the same state as the master flip-flop. In addition to these two flip-flops, the circuit also includes an inverter. The inverter is connected to clock pulse in such a way that the inverted CP is given to the slave flip-flop. For example, if the CP=0 for a master flip-flop, then the output of the inverter is 1, and this value is assigned to the slave flip-flop. In other words if CP=0 for a master flip-flop, then CP=1 for a slave flip-flop. A master-slave flip flop can be constructed using any type of flip-flop which forms a combination with a clocked RS flip-flop, and with an inverter as slave circuit. An RS master-slave flip-flop consists of two RS flip-flops; one is the master flip-flop and the other a slave. The inverted CP is given to the slave flip-flop. Now when CP=0, the master flip-flop is disabled. So the external inputs R and S of the master flip-flop will not affect the circuit until CP goes to 1. The inverter output goes to 1 and it enables the slave flip-flop. The output Q=Y and Q=Y. When CP=1, the master flip-flop is enabled and the slave flip-flop remains isolated from the circuit until CP goes back to 0. Now Y and Y depends on the external inputs R and S of the master flip-flop. Assume that the flip-flop is in a clear state and no clock pulse is applied to the circuit. The external inputs given are S=1 and R=0. This input will not affect the state of the system until the CP=1. Now the next clock pulse applied should change the state to SET state (S=1, R=0). During the clock pulse transition from 0 to 1, the master flip-flop goes to set state and changes the output Y to 1. However this does not affect the output of the system since the slave flip-flop is isolated from the system (CP=0 for slave). So no change is observed at the output of the system. When the CP returns to 0, the master flip-flop is disabled while the slave is enabled. So the information from the master is allowed to pass through to the slave. Since Y=1, this changes the output Q to 1. In a master slave flip-flop it is possible to change the output of the flip-flop and the external input with same clock pulse. This is because the external input S can be changed at the same time while the pulse goes through its negative edge transition. When CP=0, change in external input S would not affect the state of the system. From this behavior of the master slave flip-flop it is quite clear that the state change in flip-flops coincide with the negative edge transition of the pulse. Negative edge transition means an inverter is attached between the CP terminal and the input of the slave. In positive edge triggered master slave flip-flops an additional inverter is attached between the CP terminal and the input of the master. Such flip-flops are triggered with negative pulses. Negative edge of the pulse affects the master and positive edge affects the slave. Timing Diagram The timing relationship is shown in figure and is assumed that the flip-flop is in the clear state prior to the occurrence of the clock pulse. The output state of the master-slave flip-flop occurs on the negative transition of the clock pulse. Some master-slave flip-flops change output state on the positive transition of the clock pulse by having an additional inverter between the CP terminal and the input of the master. Let us say that a clock of certain frequency is fed to the FF, and consider the case of JK being 11. The propagation delay of FF is very very less than the clock pulse time.The FF continues complementing the output an unpredictable number of times, thus leading to anomaly in the final output after the pulse time of the clock is completed.At the end the clock pulse, the value of O is uncertain.This continuous toggling of output when clock is HIGH is known asRace Around condition. This can be eliminated by Clock time should be less than the propagation delay time of the latch. By using Masterslave JK Flip flop. Pulse-Triggered Master-Slave These flip-flops are constructed from two separate flip-flops. The term pulse-triggered means that data are entered into the flip-flop on the leading edge of the clock pulse, but the output does not reflect the input state until the trailing edge of the clock pulse. This is due to the master flip-flop being rising edge triggered and the slave flip-flop being falling edge triggered as illustrated in the figure below. Master-Slave J-K Flip-Flop A master slave flip flop is a cascade of two S R flip flops with feedback from the outputs of the second to the inputs of the first. Positive clock pulses are applied to the first flip flop and clock pulses are inverted before these are applied to the second flip flop. The logic symbol for the master-slave flip-flop only indicates the initial inputs to the master and the outputs from the slave as indicated by the J-K master-slave flip-flop shown in figure Operation of master-slave J-k flip flop Whe CK=1, the first flip flop is enabled and the outputs Q and Q(toggle) respond to the J K according to its truth table.At this time the second flip flop is inhibited because its clock is LOW. When CK goes LOW, the first flip flop is inhibited and the second flip flop is enabled, because now its clock isHIGH.Since the second flip flop simply follows the first one it is referred to as slave and he first one as the master. Master-slave D flip-flop Consider the following terms: RIPPLE THROUGH: An input changes level during the clock period, and the change appears at the output. PROPAGATION DELAY: The time between applying a signal to an input, and the resulting change in the output. These problems can be overcome by masterslave D Flip flop. A master-slave D flip-flop is created by connecting two gated D latches in series, and inverting the enable input to one of them. It is called master-slave because the second latch in the series only changes in response to a change in the first (master) latch. The term pulse-triggered means that data is entered on the rising edge of the clock pulse, but the output does not reflect the change until the falling edge of the clock pulse. It responds on the negative edge of the enable input usually a clock. For a positive-edge triggered master-slave D flip-flop, when the clock signal is low (logical 0) the enable seen by the first or master D latch (the inverted clock signal) is high (logical 1). This allows the master latch to store the input value when the clock signal transitions from low to high. As the clock signal goes high (0 to 1) the inverted enable of the first latch goes low (1 to 0) and the value seen at the input to the master latch is locked. Nearly simultaneously, the twice inverted enable of the second or slave D latch transitions from low to high (0 to 1) with the clock signal. This allows the signal captured at the rising edge of the clock by the now locked master latch to pass through the slave latch. When the clock signal returns to low (1 to 0), the output of the slave latch is locked, and the value seen at the last rising edge of the clock is held while the master latch begins to accept new values in preparation for the next rising clock edge. By removing the leftmost inverter in the above circuit, a D-type flip flop that strobes on the falling edge of a clock signal can be obtained. The truth table obtained is as follows: CONVENTIONS: The circuit is set means output = 1 The circuit is reset means output = 0 Flip-flops have two output Q and Q or (Q and Q) Due to time related characteristic of the flip-flop, Q and Q (or Q) are usually represented as followed: Qt or Q: present state Qt+1 or Q+: next state POINTS TO REMEMBER: When using a real flip-flop, the following information is needed to be considered: propagation delay (tpLH, tpHL) time needed for an input signal to produce an output signal minimum pulse width (tw(min)) minimum amount of time a signal must be applied setup and hold time (tsu, th) minimum time the input signal must be held fixed before and after the latching action. USES: A flip-flop is used to store one bit, or binary digit, of data. Any one of the flip-flop types can be used to build any of the others. Many logic synthesis tools will not use any other type than D flip-flop and D latch. Level sensitive latches cause problems with Static Timing Analysis (STA) tools and Design For Test (DFT). Many FPGA devices contain only edge-triggered D flip-flops The data contained in several flip-flops may represent the state of a sequencer, the value of a counter, an ASCII character in a computers memory or any other piece of information. One use is to build finite state machines from electronic logic. The flip-flops remember the machines previous state, and digital logic uses that state to calculate the next state. Frequency division: a chain of T flip-flops as described above will also function to divide an input in frequency by 2n, where n is the number of flip-flops used between the input and the output. Master Slave Flip Flop is useful in eliminating race around condition. They are used in both asynchronous and clocked sequential systems.