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.

Chemistry open book paper Essay

During radioactive decay, atoms of one element are changed into atoms of another element through the emission of alpha or beta particles from their unstable nuclei. With alpha decay the nucleus emits an alpha particle, which is essentially a helium nucleus; a group of two protons and two neutrons. It is a form of nuclear fission where the parent atom splits into two daughter products. The atomic nucleus emits an alpha particle and transforms (or ‘decays’) into an atom with a mass number 4 less and atomic number 2 less. For example: An alpha particle is the same as a helium-4 nucleus. Unlike beta decay, alpha decay is governed by the strong nuclear force. In beta decay, a neutron in the nucleus of an atom is converted into a proton and an electron. The electron is released as a beta particle. Below is the beta decay of Thorium to produce Protactinium. . In beta minus decay, the weak interaction converts a neutron into a proton while emitting an electron and an anti-neutrino. During beta-plus decay, a proton in an atom’s nucleus turns into a neutron, emitting a positron and a neutrino. Alpha rays can be blocked by a sheet of paper, shielding against beta rays needs a sheet of metal like aluminium. Nuclear fission differs from other forms of radioactive decay in that it can be harnessed and controlled via a chain reaction: free neutrons released by each fission event can trigger yet more events. Radioactive decay is spontaneous. Most nuclear fuels undergo spontaneous fission only very slowly. Nucleosynthesis in stars Hydrogen and helium are the most abundant elements in the universe. Elements heavier than lithium are all synthesized in stars. This first process of primordial nucleosynthesis may also be called nucleogenesis. In the Sun hydrogen is converted to helium in nuclear fusion reactions: 41H 4He + subatomic particles During the late stages of stellar evolution, massive stars burn helium to carbon, oxygen, silicon, sulphur, and iron. The production of small amounts of hydrogen and helium nuclei makes it possible for the star to synthesise most of the elements in the first three periods of the Periodic table. Two routes for the generation of lithium are: Route 1: 4He + 3H   7Li Route 2: 4He + 3He   7Be 7Be + electron 7Li The second route is interesting; this is because it is a form of electron capture. This is where the collision between an atom and an electron causes the proton to convert to a neutron and a neutrino is released. It is sometimes called inverse beta decay, the proton number and the structure of the nucleus is changed. Fission and Fusion Nuclear fission is the splitting of the nucleus of an atom into lighter nuclei often producing free neutrons and other smaller nuclei. The emission of these neutrons can cause further fission in other nuclei, thus producing a chain reaction. Fission of heavy elements is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments. Below is an example of nuclear fission, showing Uranium-235 splitting to create strontium-90 and xenon-143: Inside the reactor of an atomic power plant, Uranium atoms are split apart in a controlled chain reaction. This chain reaction gives off heat energy. This heat energy is used to boil water in the core of the reactor. So, instead of burning a fuel, nuclear power plants use the chain reaction of atoms splitting to change the energy of atoms into heat energy. This water from around the nuclear core is sent to another section of the power plant. Here, in the heat exchanger, it heats another set of pipes filled with water to make steam. The steam in this second set of pipes turns a turbine to generate electricity. Uranium-238 is used as a natural way to control the reaction due to the fact that it does not undergo fission. Two other mechanisms used for controlling the reaction are the graphite moderator and the control rods, which are made of boron coated steel. The neutrons that are produced when a nucleus splits are very fast moving; the graphite slows them down enough so that they cause fission reactions when they collide with Uranium-235 nuclei. The control rods which are made of Boron which absorb neutrons; they can be moved in and out of the reactor to control the rate of fission reactions. A typical absorption reaction is: Below is a cross section of the inside of a typical nuclear power plant: Notable advantages of fission include the fact that relatively little fuel is needed and the fuel is relatively inexpensive and available in trace amounts around the world. Also, it is not believed to contribute to global warming or other pollution effects associated with fossil fuel combustion. However, its major concerns include the possibility for a nuclear meltdown; an example could be the Chernobyl Disaster. Also, waste products can be used to manufacture weapons; waste from plutonium power stations remains dangerous for thousands of years. There is also high initial cost because the plant requires containment safeguards; even then, the power plants are still vulnerable from sabotage and attacks. Nuclear fusion is the process by which multiple atomic particles join together to form a heavier nucleus. It is accompanied by the release or absorption of energy. The fusion of two nuclei lighter than iron or nickel generally releases energy. Below is an example of a fusion reaction: Excess energy is released from the fusion reaction because of the lower binding energy of the helium nuclei compared to those in deuterium and tritium. The combined mass of the products is less than the mass of the reactants; the ‘lost’ mass is converted to energy, according to Einstein’s equation: E=mc2 For the below reaction to occur the particles need to form a high-density, super hot, ionized gas – plasma. 2H + 3H i 4He + 1n Tritium is produced by using lithium in the reactor, where neutrons from the deuterium-tritium reaction in the plasma will react with the lithium to produce more tritium: 6Li + 1n i 4He + 3H A way to control the plasma is to keep it away from the walls, which minimizes heat loss. To do this a tokamak is used. This device contains hot plasma in a doughnut shape within a vacuum vessel. Powerful magnetic fields created by large coils that run around the vessel keep the plasma away from the walls. Powerful electric currents heat the plasma as well as by microwaves that are directed into it and beams of fast neutron particles. Notable advantages to using nuclear fusion include the fact that there is significantly less chance of a fatal accident occurring than that of a fission reactor, because the fuel contained in the reaction chamber is only enough to sustain the reaction for about a minute. Also, Deuterium and tritium are virtually inexhaustible. Unlike fission reactors, whose waste remains dangerous for thousands of years, most of the radioactive material in a fusion reactor would remain dangerous for about 50-100 years. At present the disadvantage is merely the fact that scientists have not yet been able to contain a fusion reaction long enough for there to be a net energy gain. This is, in turn, causing many countries to phase out fusion research because of the failure to reach a breakthrough. Challenges to the future of fusion power stations The main challenge that scientists face is the growth of hydrocarbon films. Where plasma touches the walls, carbon tiles are eroded by deuterium and tritium ions, producing hydrocarbons. Further reactions result in the formation of reactive radicals, which combine with each other to form hydrocarbon films. These films cause problems because they trap the tritium and deuterium fuel ions in the walls of the device so that they are not circulating in the reacting plasma to produce any energy. Also if the film gets thicker, it begins to flake off, resulting in dust particles which can be absorbed into the plasma, affecting its purity and performance. Other issues include the potentially prohibitive costs of building, and the difficulties of repairing and maintaining the reaction vessel. This massive â€Å"blanket† of lithium and rare metals will degrade and become radioactive over time, requiring regular dismantling and replacement. No. Words – 357+368+294+145 = 1164 (excluding equations, titles, annotations and text in diagrams) – sorry! Sources http://www. answers. com/topic/nucleosynthesis? cat=technology – Nucleosynthesis http://helios. gsfc. nasa. gov/nucleo. html – Nucleosynthesis http://physics. bu. edu/py106/notes/RadioactiveDecay.html – Alpha and beta equations http://map. gsfc. nasa. gov/universe/bb_tests_ele. html – Nucleosynthesis http://chemed. chem. purdue. edu/genchem/topicreview/bp/ch23/modes. php. Alpha and Beta decay http://media. nasaexplores. com/lessons/01-060/images/Uran235. jpg – Fission of uranium-235 http://hyperphysics. phy-astr. gsu. edu/Hbase/nucene/fusion. html – Nuclear fusion http://www. iter-india. res. in/images/jet_tokamak. jpg. Tokamak image, Fig 5 http://www. newscientist. com/channel/fundamentals/dn8827-no-future-for-fusion-power-says-top-scientist. html – Problems for fusion power http://eazyvg. linuxoss.com/2007/08/21/fusion-is-the-future-choice-for-nuclear-power-generation/ – Fission and fusion diagrams, advantages and disadvantages of fission and fusion. Fig 1 and 3 http://www. physlink. com/Education/AskExperts/ae534. cfm – Bond energy per nucleon, Fig 5 Article 1 – Box 1 – pg3 Article 1 – Second paragraph under â€Å"Nuclear fission† – pg4-5 Article 1 – Box 2 – Used for finding out control mechanisms – pg6 Article 2 – Advantages of fusion power, ways it produces energy – pg8 Article 2 – Box 2 – Lithium generation and equations – pg9 Article 2 – Box 2 – Fusion reactions – pg10 Article 2 – Tokamak, problems facing scientists – pg10.

Finance And Accounting In The Media Industry Accounting Essay

Media and amusement includes a assortment of merchandises that entertains or keeps informed a day-to-day consumer. The industry is segmented into wireless, telecasting, wireless broadcast medium, etc. The competition in the media and amusement infinite is increasing twenty-four hours by twenty-four hours. To be on the top or even to last in this extremely competitory market one has to be really efficient in pull offing the information systems.Finance and AccountingRelationship to Accounting: There is really small difference between finance and accounting. Both autumn under the legal power of main fiscal officer who uses a peculiar MIS to function the intent of both. The difference lies in the sense that in finance the intent is to maximise the net income whereas the intent of accounting is score maintaining so that a base for revenue enhancement payment is prepared. A fiscal director analyses the natural information ( provided by the comptroller about the company ‘s yesteryear, present and future ) as inputs to MIS for doing of import determinations. Accounting is non concerned with hard currency flows. It is merely based on the recognized grosss when sale occurs. Finance is merely concerned to hard currency flows. The magnitude, timing and hazard of hard currency flows are the focal point of finance director. Finance involves determination doing under unsure conditions and is concerned with future whereas accounting is concerned with the past records.WHY MIS IS USED?ALarge organisations have a batch of information. This aggregation of informations can non be of any usage if it is non streamlined so that informations can be retrieved easy. MIS would assist in commanding, tracking and monitoring of informations. Segregation of informations into faculties would ensue in faster determination devising. Would assist in traveling paper free. Use of MIS would guarantee the consequence as per the outlook and analysis of informations would be done easy.SAP FOR FINANCE IN MEDIA AND ENTERTAINMENThypertext transfer protocol: //www.sap.com/global/images/tce/spacer.gif Reliance Mediaworks uses SAP for functioning its fiscal jobs. SAP for Media provides trim solutions to maintain up with rapid alterations driven by the Internet, on-line publication, and digital broadcast medium. License acquisition and surpassing royalties – Reports on accurate royalty statements are prepared utilizing SAP. Core accounting and coverage capablenesss Fiscal supply concatenation direction Treasury Management Shared services Supply Chain ManagementRELIANCE MEDIAWORKSCompany profile In 2005 Reliance ventured into this infinite and rapidly adopted the criterions required to last in this market. The twelvemonth 2005 saw the entry of new participants across all sections of the E & A ; M industry. Reliance made its manner into amusement by purchasing out ‘Adlabs ‘ and besides acquired a wireless station known as BIG FM 92.7after command for 50 FM wireless Stationss across with aggregative commands of over INR 1.5 billion. In this M & A ; E industry one can non bury the function of finance and accounting in the success way of these companies. Finance and accounting should be really efficient so that there are no statistical errors/delays. The presence of trust mediaworks is felt in Film Services: Motion Picture Processing and DI ; Visual Effects ; Film Restoration and image sweetening ; Digital Mastering: Studios and Equipment leases with installations located at US and India. Most companies that fail in this industry have no or hold a weak information system for finance and accounting system. Finance holds the key for company ‘s success. Reliance Media works adopted a really good MIS every bit shortly as it entered the infinite. It implemented a ‘SAP ‘ made MIS and rapidly got the positive consequences of utilizing it. Use of SAP in Reliance Mediaworks Used for accounting intents. Used for revenue enhancement intents. Used for organizing general legers. Keeping collectible and receivable histories. Besides used for computation of assorted ratios and analyzing them. Used for preparation of one-year and quarterly studies. Used for puting up a fixed budget.AccountingFiscal accounting consists of: – General ledger – Sap helps in pull offing a general leger for the company. General leger keeps an history of the assets, grosss, disbursals and the liabilities of the company. At the bosom of the Financials faculty, the General Ledger constituent automates the integrating of all your fiscal information and poster to your histories – supplying the terminal point for all drumhead information in the system. From the General Ledger all the cardinal direction studies of your concern ‘ are generated, including the balance sheet, gross statement, trading history and test balance. Comprehensive bore down capablenesss and graphical coverage makes job designation and declaration simple in the extreme. The General Ledger shops information on all of your histories, including all minutess – supplying the ability to update work-in advancement, stock values, foreign currency fluctuations, debitors and creditors, so that an accurate representation of the concern ‘ fiscal state of affairs is ever presented. Flexibility is provided in the set up of your chart of histories, which can be standard of customised to accommodate the alone demands of you concern. Full integrating from the full Prism system ensures the General Ledger presents dependable, accurate and timely direction information. Treasury Management of Assetss Reliance has a separate faculty for the intent of exchequer direction. This faculty invariably manages the assets and the investings that have been made by the company. Investings Reliance Mediaworks is invested in many bonds and common financess. The list of these investings every bit good as such other investings is maintained by SAP. New investings to be made are besides analysed by the MIS. A proviso for decline is made to recognize a diminution, other than impermanent, in the value of long-run investings and is determined individually for each single investing. Fixed assets and depreciation / amortization Tangible assets Assetss that can be equated in footings of money are known as touchable assets. Expenses incurred for up maintaining of the assets are taken into history. Depreciation on fixed assets is provided on the consecutive line method, . Cost of movie rights comprises original purchase monetary value / minimal warrant. Cost is ascertained on specific designation footing where possible. In instance multiple movies / rights are acquired for a amalgamate sum, cost is allocated to each movie / right based on direction ‘s best estimations. The single movie prognosis method is used to amortize the cost of movie rights acquired. Under this method, costs are amortised in the proportion that gross grosss realised bear to direction ‘s estimation of the entire gross grosss expected to be received. If estimations of the entire grosss and other events or alterations in fortunes indicate that the realisable value of a right is less than its unamortised cost, a loss is recognised for the surplus of unamortised cost over the movie right ‘s realisable value. Liabilitiess illustrations of liability histories include histories collectible and long term debt. Gross Gross is recognised to the extent that it is likely that the economic benefits will flux to the Company and the gross can be faithfully measured. Advertisement / sponsorship gross Reliance generates its grosss from advertizements and sponsorships that it offers to assorted companies. Large Frequency modulation every bit good as some other subordinates of ‘Reliance Mediaworks ‘ like the ‘Adlabs ‘ generates grosss through advertisement offerings. Film production and related income The twenty-four hours the movie rights are sold, the income/revenue from movie production is registered in the book of histories. Income from movie distribution activity Distribution rights for a movie produced by Reliance Mediaworks, abroad rights, picture, music or orbiter rights are sold and the grosss are registered by SAP. Film production services Gross from treating / printing of cinematographic movies is recognised upon completion of the related processing / printing. Theatrical exhibition and related income Grosss are besides generated by the sale of tickets at Big Cinemas. The amusement revenue enhancement is exempted from the gross. Interest income / income from movie funding Grosss may besides be generated from financing a peculiar movie and so finally purchasing the movie. Foreign currency minutess Due to operations in assorted states, Reliance has the grosss in assorted currencies which is converted into rupees at the terminal of the twelvemonth. The difference in exchange rates may do extra gross for the company. Expense/Cost Expense or cost can specify as escapes from the company. Personal costs Wages, rewards, fillips, PPF, staff public assistance disbursals Operational costs Advertisement, bank charges, rent, insurance, labor charges, loss on sale, bad debts, printing and communicating, other assorted disbursals. Other costs include involvement payment on the loans, fiscal charges etc. Receivable accounts- : Pull offing a list of receivable histories can be really boring if done manually. This job is solved utilizing SAP which records and manages such histories. The Accounts Receivable constituent of the Prism Financials faculty reveals a 360AÂ ° position of gross revenues public presentation – the footing for accurate and effectual decision-making. Histories Receivable shops all client information, footings, minutess and balances, streamlining dayto- twenty-four hours disposal. It provides direction with full and accurate graphical analysis, projections of gross revenues, grosss and hard currency flow. Credit control installations with comprehensive diary notes and gross revenues history facilitate easy client direction. Full integrating is provided from Histories Receivable to the General Ledger and Cash Book constituents of the Financials faculty, every bit good as the Job Costing and Inventory faculties on a existent clip footing. Collectible accounts- : Merely as we have receivable histories to enter the income so besides a record should be maintained for the outgoing payments that are to be made. With the Histories Collectible constituent of the Prism Financials faculty you ‘ll accomplish efficiencies throughout your bill and payment procedure. By hive awaying all your provider information, minutess and balances, and supplying elaborate analysis of your purchases, Accounts Payable will turn out an priceless tool within your histories section. Staff can automatically make payment tallies and print computerised cheques and remittals, in add-on to leting multiple currencies by creditor. Extensive graphical coverage on all disbursals incurred provides direction with critical determination doing information. Taxation- : Calculation of revenue enhancements ( gross revenues and purchases ) and coverage of the same is easy done utilizing SAP. Income-tax disbursal comprises current revenue enhancement disbursal computed in conformity with the relevant commissariats of the Income revenue enhancement Act, 1961 and deferred revenue enhancement charge or recognition. Deferred revenue enhancement charge or recognition and the corresponding deferred revenue enhancement liability or plus is recognised for clocking differences between the net incomes / losingss offered for income revenue enhancements and net incomes / losingss as per the fiscal statements. Deferred revenue enhancement assets and liabilities are measured utilizing the revenue enhancement rates and revenue enhancement Torahs that have been enacted or substantively enacted at the balance sheet day of the month. Entertainment revenue enhancement is besides levied as a signifier of revenue enhancement. Accrual accounting- : Accrual means entering gross or cost every bit shortly as they are earned and non wait for the clip when they would be settled. SAP helps in pull offing collectible and receivable histories harmonizing to accrual accounting.Benifits to Reliance MediaworksThe operating costs have reduced and the efficiency has been increased thereby increasing the entrance royalties. The dealing and communicating charges have gone down drastically thereby increasing the net income borders for the company. The cost of integrating with finance and accounting direction has cut downing and has resulted in incremental gross for the company. Replacing manual accounting with the new system has improved the transparence and simpleness of pull offing histories. Version: SAP Crystal Reports Editions: SAP Crystal Reports comes in a individual edition that is the feature equivalent of the old Developer Edition. SAP Crystal Reports Dashboard Design bundle is a soft package of SAP Crystal Reports and SAP Crystal Dashboard Desing ( once known as Xcelsius Engage ) . Datas beginnings: Native, ODBC, OLE DB, and JDBC connectivity to relational, OLAP, web services, XML, and enterprise informations beginnings, and new salesforce.com driver. License theoretical account: Licensed per named user Languages: English, Gallic, German, Italian, Spanish, Portuguese ( Brazilian ) , Dutch, Swedish, Russian, Simplified Chinese, Traditional Chinese, Japanese, Korean, Polish, Norwegian, Thai, Czech, and FinnishSystem RequirementsDisk infinite: 300 MB available difficult thrust infinite, 600 MB recommended with SAP Crystal Reports, version for Ocular Studio.NET Operating systems: Microsoft Windows 7, Windows Vista, Windows XP with Service Pack ( SP ) 2, Windows Server 2003 with SP1, or subsequently Integrated development environments: SAP Crystal Reports, version for Ocular Studio 2008, 2005, and 2003 Brassy Support: Embedded Flash objects can be viewed with the.NET Winform spectator, .Net Webform spectator, Java DHTML spectator, SAP Crystal Reports spectator, and exported PDF files.

My Experience At The Military Service - 1611 Words

I remember that I served in military service at three years ago, and serving the military service was my perfect turning point that changed my entire life. I remember that when I was 20, I was very introverted that I could not even talk with other people to ask the directions. I remember that I just reached young adult who did not know about the world and just graduated from high school. I remember that I didn’t have any confidence, passion, patience, and willingness to challenge myself for my goals when I graduated from high school at 20. I remember that I didn’t attend college after I graduated from high school. I remember that I determined to serve in military instead of attending college because I didn’t know what I want to do and†¦show more content†¦I remember that during the five week long boot camp, I experienced that I had never experienced before in my life. It was really painful to adapt myself to new circumstances. I remember that I should have woken up at 6 am, and as soon as I woke up, I should have run three miles at dawn when ordinary people usually sleep at that time. I remember that Whenever I ate my breakfast, lunch and dinner, the trainers of the boot camp gave me only 10 minutes to finish my mealtime, and eating my meal in 10 minutes was really hard for me to finish my meal. If I didn’t finish my meal in 10 minutes, the trainers gave me disciplinary punishment such as one hundred push-ups or push-up position for 10 minutes. I remember that kitchen police didn’t even give me an enough food to endure the hard drill. I remember that everything that I did in the boot camp perfectly annoyed me. I remember that whenever I received the training from the boot camp, all the trainers of the boot camp yelled at me. I remember that whenever I heard swear words from trainers, I kept speaking ill of those trainers in my mind. I remember that whenever I went to sleep, I couldn’t stop thinking about the outside world. I remember that I just missed my friends who enjoyed their lives in the club at every Saturday night. I remember that I was so jealous of friends because they could sleep whenever they want to sleep, and they could eat whatever