122 research outputs found
Bose and Fermi gases in the early universe with self-gravitational effect
We study the self-gravitational effect on the equation of state (EoS) of Bose
and Fermi gases in thermal equilibrium at the end of reheating, the period
after quark-hadron transition and before Big Bang Nucleosynthesis (BBN). After
introducing new grand canonical partition functions based on the work of
Uhlenbeck and Gropper, we notice some interesting features of the newly
developed EoSs with distinct behaviors of relativistic and non-relativistic
gases under self-gravity. The usual negligence of the self-gravitational effect
when solving the background expansion of the early universe is justified with
numerical results, showing the magnitude of the self-gravitational modification
of the state constant to be less than . This helps us to clarify
the background thermal evolution of the primordial patch. Such clarification is
crucial in testing gravity theories, evaluating inflation models and
determining element abundances in BBN.Comment: 10 pages, 2 figures, to appear in PR
Recombinational landscape of porcine X chromosome and individual variation in female meiotic recombination associated with haplotypes of Chinese pigs
<p>Abstract</p> <p>Background</p> <p>Variations in recombination fraction (θ) among chromosomal regions, individuals and families have been observed and have an important impact on quantitative trait loci (QTL) mapping studies. Such variations on porcine chromosome X (SSC-X) and on other mammalian chromosome X are rarely explored. The emerging assembly of pig sequence provides exact physical location of many markers, facilitating the study of a fine-scale recombination landscape of the pig genome by comparing a clone-based physical map to a genetic map. Using large offspring of F<sub>1 </sub>females from two large-scale resource populations (Large White ♂ × Chinese Meishan ♀, and White Duroc ♂ × Chinese Erhualian ♀), we were able to evaluate the heterogeneity in θ for a specific interval among individual F<sub>1 </sub>females.</p> <p>Results</p> <p>Alignments between the cytogenetic map, radiation hybrid (RH) map, genetic maps and clone map of SSC-X with the physical map of human chromosome X (HSA-X) are presented. The most likely order of 60 markers on SSC-X is inferred. The average recombination rate across SSC-X is of ~1.27 cM/Mb. However, almost no recombination occurred in a large region of ~31 Mb extending from the centromere to Xq21, whereas in the surrounding regions and in the Xq telomeric region a recombination rate of 2.8-3.3 cM/Mb was observed, more than twice the chromosome-wide average rate. Significant differences in θ among F<sub>1 </sub>females within each population were observed for several chromosomal intervals. The largest variation was observed in both populations in the interval <it>UMNP71-SW1943</it>, or more precisely in the subinterval <it>UMNP891-UMNP93</it>. The individual variation in θ over this subinterval was found associated with F<sub>1 </sub>females' maternal haplotypes (Chinese pig haplotypes) and independent of paternal haplotype (European pig haplotypes). The θ between <it>UMNP891 </it>and <it>UMNP93 </it>for haplotype 1122 and 4311 differed by more than fourteen-fold (10.3% vs. 0.7%).</p> <p>Conclusions</p> <p>This study reveals marked regional, individual and haplotype-specific differences in recombination rate on SSC-X. Lack of recombination in such a large region makes it impossible to narrow QTL interval using traditional fine-mapping approaches. The relationship between recombination variation and haplotype polymorphism is shown for the first time in pigs.</p
Genome-wide identification of QTL for age at puberty in gilts using a large intercross F2 population between White Duroc and Erhualian
Puberty is a fundamental development process experienced by all reproductively competent adults, yet the specific factors regulating age at puberty remain elusive in pigs. In this study, we performed a genome scan to identify quantitative trait loci (QTL) affecting age at puberty in gilts using a White Duroc × Erhualian intercross. A total of 183 microsatellites covering 19 porcine chromosomes were genotyped in 454 F2 gilts and their parents and grandparents in the White Duroc × Erhualian intercross. A linear regression method was used to map QTL for age at puberty via QTLexpress. One 1% genome-wise significant QTL and one 0.1% genome-wise significant QTL were detected at 114 cM (centimorgan) on SSC1 and at 54 cM on SSC7, respectively. Moreover, two suggestive QTL were found on SSC8 and SSC17, respectively. This study confirmed the QTL for age at puberty previously identified on SSC1, 7 and 8, and reports for the first time a QTL for age at puberty in gilts on SSC17. Interestingly, the Chinese Erhualian alleles were not systematically favourable for younger age at puberty
Sexually dimorphic genetic architecture of complex traits in a large-scale F2 cross in pigs
BACKGROUND: It is common for humans and model organisms to exhibit sexual dimorphism in a variety of complex traits. However, this phenomenon has rarely been explored in pigs. RESULTS: To investigate the genetic contribution to sexual dimorphism in complex traits in pigs, we conducted a sex-stratified analysis on 213 traits measured in 921 individuals produced by a White Duroc × Erhualian F(2) cross. Of the 213 traits examined, 102 differed significantly between the two sexes (q value <0.05), which indicates that sex is an important factor that influences a broad range of traits in pigs. We compared the estimated heritability of these 213 traits between males and females. In particular, we found that traits related to meat quality and fatty acid composition were significantly different between the two sexes, which shows that genetic factors contribute to variation in sexual dimorphic traits. Next, we performed a genome-wide association study (GWAS) in males and females separately; this approach allowed us to identify 13.6% more significant trait-SNP (single nucleotide polymorphism) associations compared to the number of associations identified in a GWAS that included both males and females. By comparing the allelic effects of SNPs in the two sexes, we identified 43 significant sexually dimorphic SNPs that were associated with 22 traits; 41 of these 43 loci were autosomal. The most significant sexually dimorphic loci were found to be associated with muscle hue angle and Minolta a* values (which are parameters that reflect the redness of meat) and were located between 9.3 and 10.7 Mb on chromosome 6. A nearby gene i.e. NUDT7 that plays an important role in heme synthesis is a strong candidate gene. CONCLUSIONS: This study illustrates that sex is an important factor that influences phenotypic values and modifies the effects of the genetic variants that underlie complex traits in pigs; it also emphasizes the importance of stratifying by sex when performing GWAS. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12711-014-0076-2) contains supplementary material, which is available to authorized users
A genome-wide scan for quantitative trait loci affecting limb bone lengths and areal bone mineral density of the distal femur in a White Duroc × Erhualian F2 population
<p>Abstract</p> <p>Background</p> <p>Limb bone lengths and bone mineral density (BMD) have been used to assess the bone growth and the risk of bone fractures in pigs, respectively. It has been suggested that limb bone lengths and BMD are under genetic control. However, the knowledge about the genetic basis of the limb bone lengths and mineralisatinon is limited in pigs. The aim of this study was to identify quantitative trait loci (QTL) affecting limb bone lengths and BMD of the distal femur in a White Duroc × Erhualian resource population.</p> <p>Results</p> <p>Limb bone lengths and femoral bone mineral density (fBMD) were measured in a total of 1021 and 116 F<sub>2 </sub>animals, respectively. There were strong positive correlations among the lengths of limb bones and medium positive correlations between the lengths of limb bones and fBMD. A whole-genome scan involving 183 microsatellite markers across the pig genome revealed 35 QTL for the limb bone lengths and 2 for femoral BMD. The most significant QTL for the lengths of five limb bones were mapped on two chromosomes affecting all 5 limb bones traits. One was detected around 57 cM on pig chromosome (SSC) 7 with the largest <it>F</it>-value of more than 26 and 95% confidence intervals of less than 5 cM, providing a crucial start point to identify the causal genes for these traits. The Erhualian alleles were associated with longer limb bones. The other was located on SSCX with a peak at 50–53 cM, whereas alleles from the White Duroc breed increased the bone length. Many QTL identified are homologous to the human genomic regions containing QTL for bone-related traits and a list of interesting candidate genes.</p> <p>Conclusion</p> <p>This study detected the QTL for the lengths of scapula, ulna, humerus and tibia and fBMD in the pig for the first time. Moreover, several new QTL for the pig femoral length were found. As correlated traits, QTL for the lengths of five limb bones were mainly located in the same genomic regions. The most promising QTL for the lengths of five limb bones on SSC7 merits further investigation.</p
Problematika Penyelesaian Sengketa Kewenangan Lembaga Negara Oleh Mahkamah Konstitusi
According to Article 24C verse (1) of the 1945 Constitution, Constitutional court has an authority to examine the dispute among the state institution in which its authority is given by the constitution directly. But there is a certain problem in practice which is related to definition of “state institution” and “authorities are granted the Constitution” in the 1945 Constitution. This condition opens a debate the interpretation in executing the settlement on authority dispute among the institutions. In addition, should be considered the settlement of disputes the authority of institutions, whose authority derived from regulation other than the Constitution
Menurut ketentuan Pasal 24C ayat (1) UUD NRI Tahun 1945, penyelesaian sengketa kewenangan lembaga negara yang kewenangannya diberikan oleh UUD merupakan kewenangan Mahkamah Konstitusi. Namun dalam praktiknya, proses penyelesaian sengketa kewenangan lembaga negara menghadapi problem tersendiri seiring tidak adanya batasan ruang lingkup dan definisi “lembaga negara” dan frasa “kewenangannya diberikan UUD” secara pasti dalam UUD NRI Tahun 1945. Situasi ini pada akhirnya menimbulkan multitafsir yang berpotensi mengakibatkan tidak efektifnya penyelesaian sengketa kewenangan lembaga negara di Indonesia. Selain itu, perlu dipikirkan mekanisme penyelesaian sengketa kewenangan lembaga yang kewenangannya bersumber dari peraturan selain UUD
Genome-wide QTL mapping for three traits related to teat number in a White Duroc × Erhualian pig resource population
<p>Abstract</p> <p>Background</p> <p>Teat number is an important fertility trait for pig production, reflecting the mothering ability of sows. It is also a discrete and often canalized trait presenting bilateral symmetry with minor differences between the two sides, providing a potential power to evaluate fluctuating asymmetry and developmental instability. The knowledge of its genetic control is still limited. In this study, a genome-wide scan was performed with 183 microsatellites covering the pig genome to identify quantitative trait loci (QTL) for three traits related to teat number including the total teat number (TTN), the teat number at the left (LTN) and right (RTN) sides in a large scale White Duroc × Erhualian resource population.</p> <p>Results</p> <p>A sex-average linkage map with a total length of 2350.3 cM and an average marker interval of 12.84 cM was constructed. Eleven genome-wide significant QTL for TTN were detected on 8 autosomes including pig chromosomes (SSC) 1, 3, 4, 5, 6, 7, 8 and 12. Six suggestive QTL for this trait were detected on SSC6, 9, 13, 14 and 16. Eight chromosomal regions each on SSC1, 3, 4, 5, 6, 7, 8 and 12 showed significant associations with LTN. These regions were also evidenced as significant QTL for RTN except for those on SSC6 and SSC8. The most significant QTL for the 3 traits were all located on SSC7. Erhualian alleles at most of the identified QTL had positive additive effects except for three QTL on SSC1 and SSC7, at which White Duroc alleles increased teat numbers. On SSC1, 6, 9, 13 and 16, significant dominance effects were observed on TTN, and predominant imprinting effect on TTN was only detected on SSC12.</p> <p>Conclusion</p> <p>The results not only confirmed the QTL regions from previous experiments, but also identified five new QTL for the total teat number in swine. Minor differences between the QTL regions responsible for LTN and RTN were validated. Further fine mapping should be focused on consistently identified regions with small confidence intervals, such as those on SSC1, SSC7 and SSC12.</p
Concept Design of the “Guanlan” Science Mission: China’s Novel Contribution to Space Oceanography
Among the various challenges that spaceborne radar observations of the ocean face, the following two issues are probably of a higher priority: inadequate dynamic resolution, and ineffective vertical penetration. It is therefore the vision of the National Laboratory for Marine Science and Technology of China that two highly anticipated breakthroughs in the coming decade are likely to be associated with radar interferometry and ocean lidar (OL) technology, which are expected to make a substantial contribution to a submesoscale-resolving and depth-resolving observation of the ocean. As an expanded follow-up of SWOT and an oceanic counterpart of CALIPSO, the planned “Guanlan” science mission comprises a dual-frequency (Ku and Ka) interferometric altimetry (IA), and a near-nadir pointing OL. Such an unprecedented combination of sensor systems has at least three prominent advantages. (i) The dual-frequency IA ensures a wider swath and a shorter repeat cycle which leads to a significantly improved temporal and spatial resolution up to days and kilometers. (ii) The first spaceborne active OL ensures a deeper penetration depth and an all-time detection which leads to a layered characterization of the optical properties of the subsurface ocean, while also serving as a near-nadir altimeter measuring vertical velocities associated with the divergence, and convergence of geostrophic eddy motions in the mixed layer. (iii) The simultaneous functioning of the IA/OL system allows for an enhanced correction of the contamination effects of the atmosphere and the air-sea interface, which in turn considerably reduces the error budgets of the two sensors. As a result, the integrated IA/OL payload is expected to resolve the ocean variability at submeso and sub-week scales with a centimeter-level accuracy, while also partially revealing marine life systems and ecosystems with a 10-m vertical interval in the euphotic layer, moving a significant step forward toward a “transparent ocean” down to the vicinity of the thermocline, both dynamically and bio-optically
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