A more complete description of African elephant phylogeography would require a method that distinguishes forest and savanna elephants using DNA from low-quality samples. Although mitochondrial DNA is often the marker of choice for species identification, the unusual cytonuclear patterns in African elephants make nuclear markers more reliable. We therefore designed and utilized genetic markers for short nuclear DNA regions that contain fixed nucleotide differences between forest and savanna elephants. We used M13 forward and reverse sequences to increase the total length of PCR amplicons and to improve the quality of sequences for the target DNA. We successfully sequenced fragments of nuclear genes from dung samples of known savanna and forest elephants in the Democratic Republic of Congo, Ethiopia, and Namibia. Elephants at previously unexamined locations were found to have nucleotide character states consistent with their status as savanna or forest elephants. Using these and results from previous studies, we estimated that the short-amplicon nuclear markers could distinguish forest from savanna African elephants with more than 99% accuracy. Nuclear genotyping of museum, dung, or ivory samples will provide better-informed conservation management of Africa's elephants.
We commercialized a large-size optical current transformer (OCT) using the Faraday effect for the Cable Head Station of Hokkaido-Honshu HVDC Link for cable protection. The rated current and voltage of the HVDC are ±1200 A and ±250 kV, respectively. The diameter of the sensing head of the OCT is about 2 m and it is applicable not only to newly constructed cable heads but also to existing cable heads without disassembling a cable head bushing. The field test of the OCT was conducted at Furukawa Cable Head Station for more than one year and we confirmed long-term stability. In the field test, ambient temperature changed in the range from -15degC to 27degC. Primary current measured by the OCT was compared to that measured by a Kraemer-type DCCT, and the data were consistent. Reflecting the field test results, we manufactured the OCT for commercial installation. Factory tests of the OCT for commercial installation were conducted. Ratio error, frequency response, and the results of other tests satisfied their criteria. In particular, we measured temperature characteristics precisely and confirmed that the ratio error of the total system at any ambient temperature, including dispersion, satisfied the required specification, which is equivalent to IEC 60044-8 class 1.0.
Toll-like receptor 2 (TLR2) plays an important role in recognition by the innate immune system of Gram-positive bacteria. As Gram-positive bacteria cause mastitis, we examined variations in the region of the TLR2 gene that codes for the extracellular domain. Samples of forty goats from a single dairy herd were collected, half with low SCC (≤200,000 cells/mL), and half with higher SCC. Two synonymous single nucleotide polymorphisms (SNPs) were identified: 840G > A and 1083A > G. One nonsynonymous SNP 739G > A was identified. This coded for valine or isoleucine, which have similar physiochemical properties, and was not in a region coding for a known functional domain. Surprisingly, the least square mean SCC of the heterozygous goats (146,220) was significantly lower than the SCC of homozygous GG goats (537,700; p = 0.004), although these two groups were similar in days in milk (p = 0.984), and there was no significant difference by breed (p = 0.941). Because factors other than mastitis can affect SCC and our sample sizes were limited, additional studies are needed to corroborate an association between TLR2 genotype and SCC or mastitis in goats.
Betaine-homocysteine S-methyltransferase (BHMT) and BHMT2 convert homocysteine to methionine using betaine and S-methylmethionine, respectively, as methyl donor substrates. Increased levels of homocysteine in blood are associated with cardiovascular disease. Given their role in human health and nutrition, we identified BHMT and BHMT2 genes and proteins from 38 species of deuterostomes including human and non-human primates. We aligned the genes to look for signatures of selection, to infer evolutionary rates and events across lineages, and to identify the evolutionary timing of a gene duplication event that gave rise to two genes, BHMT and BHMT2. We found that BHMT was present in the genomes of the sea urchin, amphibians, reptiles, birds and mammals; BHMT2 was present only across mammals. BHMT and BHMT2 were present in tandem in the genomes of all monotreme, marsupial and placental species examined. Evolutionary rates were accelerated for BHMT2 relative to BHMT. Selective pressure varied across lineages, with the highest dN/dS ratios for BHMT and BHMT2 occurring immediately following the gene duplication event, as determined using GA Branch analysis. Nine codons were found to display signatures suggestive of positive selection; these contribute to the enzymatic or oligomerization domains, suggesting involvement in enzyme function. Gene duplication likely occurred after the divergence of mammals from other vertebrates but prior to the divergence of extant mammalian subclasses, followed by two deletions in BHMT2 that affect oligomerization and methyl donor specificity. The faster evolutionary rate of BHMT2 overall suggests that selective constraints were reduced relative to BHMT. The dN/dS ratios in both BHMT and BHMT2 was highest following the gene duplication, suggesting that purifying selection played a lesser role as the two paralogs diverged in function.
Diffusion‐controlled reaction kinetics of a molecular tracer was investigated in the miscible region of binary polymer mixtures. The reaction kinetics does not follow the Kohlrausch‐Williams‐Watts (KWW) mechanism and is controlled by polymer segmental free volumes in the context of classical free‐volume theory. Upon approaching the phase boundary, it was found that the reaction rates were affected by the concentration fluctuations with the wavelengths comparable to the size of the tracer in accord with the results obtained by small‐angle neutron‐scattering experiments.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffects of critical concentration fluctuations on the photocyclization of a bichromophoric molecule in the one-phase region of polystyrene/poly(vinyl methyl ether) blendsTran Cong Qui, K. Meisyo, Y. Ishida, O. Yano, T. Soen, and M. ShibayamaCite this: Macromolecules 1992, 25, 9, 2330–2335Publication Date (Print):April 27, 1992Publication History Published online1 May 2002Published inissue 27 April 1992https://pubs.acs.org/doi/10.1021/ma00035a008https://doi.org/10.1021/ma00035a008research-articleACS PublicationsRequest reuse permissionsArticle Views49Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Illegal hunting is a major threat to the elephants of Africa, with more elephants killed by poachers than die from natural causes. DNA from tusks has been used to infer the source populations for confiscated ivory, relying on nuclear genetic markers. However, mitochondrial DNA (mtDNA) sequences can also provide information on the geographic origins of elephants due to female elephant philopatry. Here, we introduce the Loxodonta Localizer (LL; www.loxodontalocalizer.org), an interactive software tool that uses a database of mtDNA sequences compiled from previously published studies to provide information on the potential provenance of confiscated ivory. A 316 bp control region sequence, which can be readily generated from DNA extracted from ivory, is used as a query. The software generates a listing of haplotypes reported among 1917 African elephants in 24 range countries, sorted in order of similarity to the query sequence. The African locations from which haplotype sequences have been previously reported are shown on a map. We demonstrate examples of haplotypes reported from only a single locality or country, examine the utility of the program in identifying elephants from countries with varying degrees of sampling, and analyze batches of confiscated ivory. The LL allows for the source of confiscated ivory to be assessed within days, using widely available molecular methods that do not depend on a particular platform or laboratory. The program enables identification of potential regions or localities from which elephants are being poached, with capacity for rapid identification of populations newly or consistently targeted by poachers.
Abstract Although among feral cats, Felis catus, females copulate with multiple males, they do not accept all mounting or copulation attempts by males during their oestrous period. We observed eight female cats over their oestrous periods to examine whether or not female cats control paternity of their offspring in the field. The females were courted by between nine and 19 males, but copulated with only three to nine of them. Firstly, we compared female receptivity to male attempts among the eight females and tested how female traits affect their receptivity. Female receptivity to male attempts varied among the females both at mounting and at copulation. Females were more choosy at the time of copulation than at mounting. Females with a shorter oestrous duration and a lighter body weight tended to accept mounts more frequently than the females with a longer oestrous duration and a higher body weight. Older and lighter females tended to accept copulation more frequently than younger and heavier females. Females courted by fewer males per day also tended to accept copulations more frequently. Secondly, combining behavioural observations and determined kinship, we assessed whether females avoided copulating with their kin. The results showed that female cats avoid inbreeding with their close kin during copulation but not with distant relatives. Copulation attempts by kin males were less frequently accepted than those by nonkin males. Thirdly, we tested whether male age and body weight affect their mating success, but we failed to find any such correlation. These results support the hypothesis that female cats control paternity of their offspring during copulation.
