Protease activity in brook trout (Salvelinus fontinalis) follicle walls demonstrated by substrate-polyacrylamide gel electrophoresis

Proteolytic activity was demonstrated in the follicle wall surrounding oocytes of brook trout (Salvelinus fontinalis) by an assay system that incorporated protein substrates into sodium dodecyl sulfate-polyacrylamide gel electrophoresis (substrate-SDS-PAGE). At least six proteolytic enzymes (78, 70, 67, 59, 22 and 20 kDa) were present when follicle wall extracts were electrophoresed and incubated in gels containing gelatin. Of these six enzymes, only two enzymes (20 and 22 kDa) were present when follicle wall extracts were resolved and incubated in gels containing casein. The activities of the 78 and 70 kDa enzymes were completely inhibited with metallo- and collagenolytic protease inhibitors and partially inhibited with serine protease inhibitors. The activities of the 67 and 59 kDa enzymes were completely blocked with metallo- and collagenolytic protease inhibitors. The activities of the 22 and 20 kDa enzymes were only slightly decreased with a serine protease inhibitor.     

Influence of exogenous testosterone on sperm production, seminal quality and libido of stallions.

The effect of exogenous testosterone on sperm production, seminal quality and libido was studied in 24 stallions. Based on pretreatment data, a stallion was assigned to 1 of 3 groups each containing 8 animals. One member of each group received 0 (Group 1), 50 (Group 2), or 200 micrograms (Group 3) testosterone propionate per kg body weight every 2 days for 88 days. The lower dose of testosterone had no significant effect on most of the parameters studied: the higher dose depressed total scrotal width at Day 90 post-treatment (P less than 0.01), total spermatozoa ejaculated between Days 60 and 90 (P less than 0.01) and 96 progressively motile spermatozoa between Days 60 and 90 (P less than 0.10). One half of the stallions from each treatment were castrated on Day 90. In the operated stallions, the mean number of spermatids per g testicular parenchyma in the controls (Group 1) was significantly (P less than 0.05) higher than that in Group 3 whereas the difference between the number of spermatids/testis in the same stallions of these two groups was significant only at P less than 0.1. Testosterone propionate treatment did not influence time to erection, interval from first mount to ejaculation or number of mounts per ejaculation. The treatment of normal, intact stallions with testosterone propionate did not enhance libido and caused a severe depression of reproductive capacity.     

Assessing sex-drive in young Bos taurus bulls

Objectives in this study were to determine the accuracy of different methods of evaluating libido score (L), service rate (SR) and reaction time to service (RTS) in yearling Bos taurus bulls. Using restrained, non-estrus females, 26 yearling Bos taurus bulls were evaluated a total of eight times (four sessions, two tests per session) over 2 consecutive months for L, SR, and RTS. Individual bull variation influenced both L (P<0.0001) and SR (P<0.003). Repeatability was moderate for L (R=0.64) and low for both SR (R=0.12) and RTS (R=0.04). Under the conditions of this study and characteristics of these tests, variance was reduced to 69-73% for L and 26-23% for SR with four to eight repetitions, respectively. Bulls that scored highly in the first session, however, tended to score highly throughout. Although, three bulls did not serve in any test, RTS was independent of effects. However, the tendency of RTS to decrease, and for L and SR to both increase with consecutive tests, suggests influences other than genetic, such as learning and/or environmental factors. These tendencies were most evident in bulls which obtained low L scores at the first session. It was concluded that, despite the important degree of individual variability observed in L and SR, accurate quantitative evaluation of the sex-drive in young Bos taurus beef bulls would benefit from use of test procedures of greater repeatability.     

Lack of Evidence for Vertical Transmission of Campylobacter spp. in Chickens

Campylobacter jejuni is a major cause of bacterial food-borne infection in the industrial world. There is evidence that C. jejuni is present in eggs and hatchery fluff, opening the possibility for vertical transmission from hens to progeny. Poultry operations in Iceland provide an excellent opportunity to study this possibility, since breeding flocks are established solely from eggs imported from grandparent flocks in Sweden. This leaves limited opportunity for grandparents and their progeny to share isolates through horizontal transmission. While Campylobacter was not detected in all grandparent flocks, 13 of the 16 egg import lots consisted of eggs gathered from one or more Campylobacter-positive grandparent flocks. No evidence of Campylobacter was found by PCR in any of the 10 relevant quarantine hatchery fluff samples examined, and no Campylobacter was isolated from the parent birds through 8 weeks, while they were still in quarantine rearing facilities. After the birds were moved to less biosecure rearing facilities, Campylobacter was isolated, and 29 alleles were observed among the 224 isolates studied. While three alleles were found in both Sweden and Iceland, in no case was the same allele found both in a particular grandparent flock and in its progeny. We could find no evidence for vertical transmission of Campylobacter to the approximately 60,000 progeny parent breeders that were hatched from eggs coming from Campylobacter-positive grandparent flocks. If vertical transmission is occurring, it is not a significant source for the contamination of chicken flocks with Campylobacter spp.     

L<Subscript>2</Subscript>-norm multiple kernel learning and its application to biomedical data fusion

Background  

This paper introduces the notion of optimizing different norms in the dual problem of support vector machines with multiple kernels. The selection of norms yields different extensions of multiple kernel learning (MKL) such as L _∞, L ₁, and L ₂ MKL. In particular, L ₂ MKL is a novel method that leads to non-sparse optimal kernel coefficients, which is different from the sparse kernel coefficients optimized by the existing L _∞ MKL method. In real biomedical applications, L ₂ MKL may have more advantages over sparse integration method for thoroughly combining complementary information in heterogeneous data sources.     

Comparative analysis of DNA polymorphisms and phylogenetic relationships among Syzygium cumini Skeels based on phenotypic characters and RAPD technique

The Indian black berry (Syzygium cumini Skeels) has a great nutraceutical and medicinal properties. As in other fruit crops, the fruit characteristics are important attributes for differentiation were also determined for different accessions of S. cumini. The fruit weight, length, breadth, length: breadth ratio, pulp weight, pulp content, seed weight and pulp: seed ratio significantly varied in different accessions. Molecular characterization was carried out using PCR based RAPD technique. Out of 80 RAPD primers, only 18 primers produced stable polymorphisms that were used to examine the phylogenetic relationship. A sum of 207 loci were generated out of which 201 loci found polymorphic. The average genetic dissimilarity was 97 per cent among jamun accessions. The phylogenetic relationship was also determined by principal coordinates analysis (PCoA) that explained 46.95 per cent cumulative variance. The two-dimensional PCoA analysis showed grouping of the different accessions that were plotted into four sub-plots, representing clustering of accessions. The UPGMA (r = 0.967) and NJ (r = 0.987) dendrogram constructed based on the dissimilarity matrix revealed a good degree of fit with the cophenetic correlation value. The dendrogram grouped the accessions into three main clusters according to their eco-geographical regions which given useful insight into their phylogenetic relationships.     

不同耕作措施对冬小麦-夏玉米复种连作系统土壤有机碳和水分利用效率的影响

在连续8年田间定位试验的基础上,分析了关中平原冬小麦 夏玉米复种连作系统2008—2009年连续两个生长季期间不同耕作措施(结合秸秆还田和不还田)对土壤有机碳和水分利用率的影响.结果表明: 相对于传统耕作,保护性耕作有利于土壤有机碳、水分利用效率和作物产量的提高,其中在“深松+秸秆还田”耕作模式下的增幅最高,土壤有机碳含量在0～30 cm土层增幅达到19.5%,水分利用效率和作物产量提高了16.9%和20.5%,而免耕模式则有效提高了0～10 cm土层有机碳含量.在该地区土壤和气候条件下,深松结合秸秆粉碎还田是最理想的耕作模式,最有利于土壤有机碳累积,并提高水分利用效率和作物产量.