Female behaviour and the interaction of male and female genital traits mediate sperm transfer during mating

Natural selection and post‐copulatory sexual selection, including sexual conflict, contribute to genital diversification. Fundamental first steps in understanding how these processes shape the evolution of specific genital traits are to determine their function experimentally and to understand the interactions between female and male genitalia during copulation. Our experimental manipulations of male and female genitalia in red‐sided garter snakes (Thamnophis sirtalis parietalis) reveal that copulation duration and copulatory plug deposition, as well as total and oviductal/vaginal sperm counts, are influenced by the interaction between male and female genital traits and female behaviour during copulation. By mating females with anesthetized cloacae to males with spine‐ablated hemipenes using a fully factorial design, we identified significant female–male copulatory trait interactions and found that females prevent sperm from entering their oviducts by contracting their vaginal pouch. Furthermore, these muscular contractions limit copulatory plug size, whereas the basal spine of the male hemipene aids in sperm and plug transfer. Our results are consistent with a role of sexual conflict in mating interactions and highlight the evolutionary importance of female resistance to reproductive outcomes.     

Capsular arabinomannans from Mycobacterium avium with morphotype-specific structural differences but identical biological activity

The capsules of two colony morphotypes of Mycobacterium avium strain 2151 were investigated, i.e. the virulent smooth-transparent (SmT1) and the nonvirulent smooth-opaque (SmO) types. From both morphotypes we separated a nonacylated arabinomannan (AM) from an acylated polysaccharide fraction by affinity chromatography, of which the AMs were structurally characterized. The AMs from the virulent morphotype, in contrast to that from the nonvirulent form, possessed a larger mannan chain and a shorter arabinan chain. Incubation of murine bone marrow-derived macrophages and human dendritic cells showed that the acylated polysaccharide fractions were potent inducers of tumor necrosis factor-alpha, interleukin-12, and interleukin-10 compared with nonacylated AMs, which led to only a marginal cytokine release. Further in vitro experiments showed that both the acylated polysaccharide fractions and the nonacylated AMs were able to induce in vitro anti-tumor cytotoxicity of human peripheral blood mononuclear cells. Thus, morphotype-specific structural differences in the capsular AMs of M. avium do not correlate with biological activity; however, their acylation is a prerequisite for effective stimulation of murine macrophages and human dendritic cells.     

New insights into the biosynthesis of mycobacterial lipomannan arising from deletion of a conserved gene

Genetic construction of a mutant strain (designated MSMEG4245) of Mycobacterium smegmatis, defective in a broadly conserved gene for a putative glycosyltransferase of the glycosyltransferase-C superfamily, results in a phenotype marked by the virtual absence of the phosphatidylinositol-containing lipomannan and lipoarabinomannan, replaced instead by a novel truncated form of lipomannan. The normal spectrum of phosphatidylinositol mannosides, long presumed precursors of these lipoglycans, was retained. Matrix-assisted laser desorption/ionization-time of flight/mass spectrometry of the mutated form of lipomannan shows a family of phosphatidylinositol-anchored lipomannans with from only 5 to 20 Manp residues as compared with lipomannan from the wild type strain consisting of 21-34 Manp residues but with few changes in the branching pattern. Thus, MSMEG4245 is apparently a key mannosyltransferase, required for the proper elongation of lipomannan to its normal state and subsequent synthesis of lipoarabinomannan. The corresponding ortholog in Mycobacterium tuberculosis H37Rv has been identified as Rv2174. This previously unrecognized feature of the biosynthesis of lipomannan/lipoarabinomannan allows a significant revision of structural and biosynthetic schemata and provides a molecular basis of selectivity in biosynthesis, as conferred by the MSMEG4245 gene.     

Applying neural networks to predict HPC-I/O bandwidth over seismic data on lustre file system for ExSeisDat

Cluster Computing - HPC or super-computing clusters are designed for executing computationally intensive operations that typically involve large scale I/O operations. This most commonly involves...     

A small change approach to prevent long-term weight gain in adults with overweight and obesity: a randomized controlled trial

Background:Efforts to manage obesity through weight loss are often unsuccessful as most adults are not able to sustain the major changes in behaviour that are required to maintain weight loss long term. We sought to determine whether small changes in physical activity and diet prevent weight gain in adults with overweight and obesity.Methods:We randomized 320 sedentary adults with overweight or obesity to monitoring alone (MA, n = 160) or a small change approach (SCA, n = 160). In Phase I (2 yr), MA participants were asked to maintain their normal lifestyle and SCA participants were counselled to make small changes in diet and physical activity, namely a suggested increase in daily step count of 2000 steps with a decrease in energy intake of 100 kcal per day, with group and individual support. Phase II (1 yr) was a passive follow-up period. The difference in change in body weight between groups at 24 and 36 months from baseline was the primary outcome. Additional outcomes included waist circumference and cardiorespiratory fitness.Results:Overall, 268 participants (83.8%) completed the 2-year intervention, and 239 (74.7%) returned at the end of the follow-up period at 3 years. The difference in body weight change between the SCA and MA groups was significant at 3, 6, 12 and 15 months from baseline, but was no longer significant at 24 months (mean change 0.9 [standard error (SE) 0.5] kg v. −0.4 [SE 0.5] kg; difference −0.6, 95% confidence interval [CI] −1.9 to 0.8) or at 36 months (−1.2 [SE 0.8] v. −0.7 [SE 0.8] kg; difference −0.5, 95% CI −2.2 to 1.2). Changes in waist circumference and cardiorespiratory fitness were not significantly different between groups at 24 or 36 months (both p > 0.1).Interpretation:The SCA did not prevent weight gain compared with monitoring alone at 2 or 3 years in adults with overweight or obesity. On average, we observed prevention of weight gain in both arms of the trial. Trial registration:ClinicalTrials.gov, no. {"type":"clinical-trial","attrs":{"text":"NCT02027077","term_id":"NCT02027077"}}NCT02027077.

Overweight and obesity contribute to chronic diseases and present a major public health challenge¹ as more than 63% of adults in Canada currently live with overweight or obesity.² Despite the urgent need to address the obesity problem, few strategies designed to reduce obesity have been broadly successful.Results from randomized controlled trials show that most adults are not able to sustain the major changes in behaviour that are required to maintain weight loss long term.^3,4 A more reasonable and achievable goal may be to focus on the prevention of weight gain. Preventing further weight gain is clinically important as even modest weight gain (0.5–1.0 kg/yr) in adults with overweight and obesity has negative associations with adverse outcomes, such as cancer,⁵ all-cause and cardiovascular disease–related death⁶ and poor health-related quality of life.⁷It has been estimated that, for 90% of the adult population, a reduction of about 100–150 kcal/d would be required to prevent positive energy balance.^8,9 Two separate pilot studies have shown that a small change approach (SCA, defined as an increase in daily step count of 2000 steps or a decrease in energy intake of 100 kcal) prevented weight gain in a small group of adults and children with overweight over 13 weeks.^9,10 More recently SCA was shown to be associated with reduced weight gain in young adults with overweight at 2 years, compared with controls.¹¹We sought to determine the effectiveness of the SCA to prevent weight gain in adults with overweight (defined as a body mass index [BMI] 25–29.9) and obesity (defined as a BMI of ≥ 30) at 2 and 3 years. We hypothesized that the SCA would prevent weight gain in comparison with monitoring of body weight alone.     

Extension of Family Planning Service in General Practice

All general practitioners on the list of a single executive council were contacted and 91% were interviewed. They were asked about the type of family planning service currently provided and their willingness to extend the service. Only 3% said that they were not providing any service at the time of interview, but only 4% stated that they provided a complete range of techniques to all patients; almost two thirds of practitioners only provided advice and the “pill”. Lack of training in family planning techniques emerged as the most important factor in determining the type of service provided. At the time of interview 64% of doctors stated that they would like further training, and 35% of all doctors asked for a full course of clinical training. Many general practitioners (81%) were willing to extend their family planning services but 65% wanted financial reimbursement and 50% needed additional administrative support as prerequisites.     

NMR structure of the haem core of a novel tetrahaem cytochrome isolated from Shewanella frigidimarina: identification of the haem-specific axial ligands and order of oxidation

The tetrahaem cytochrome isolated during anaerobic growth of Shewanella frigidimarina NCIMB400 is a small protein (86 residues) involved in electron transfer to Fe(III), which can be used as a terminal respiratory oxidant by this bacterium. A 3D solution structure model of the reduced form of the cytochrome has been determined using NMR data in order to determine the relative orientation of the haems. The haem core architecture of S. frigidimarina tetrahaem cytochrome differs from that found in all small tetrahaem cytochromes c(3) so far isolated from strict anaerobes, but has some similarity to the N-terminal cytochrome domain of flavocytochrome c(3) isolated from the same bacterium. NMR signals obtained for the four haems of S. frigidimarina tetrahaem cytochrome at all stages of oxidation were cross-assigned to the solution structure using the complete network of chemical exchange connectivities. Thus, the order in which each haem in the structure becomes oxidised was determined.     

The Antarctic toothfish (Dissostichus mawsoni) lacks plasma albumin and utilises high density lipoprotein as its major palmitate binding protein

Plasma from the Antarctic toothfish, Dissostichus mawsoni, a member of the advanced teleost Nototheniidae family, was analysed. Agarose gel electrophoresis showed a major diffuse anionic protein that bound [14C]palmitic acid but not 63Ni2+, and two more cationic proteins that bound 63Ni2+ but not palmitate. Oil Red O staining following cellulose acetate electrophoresis indicated that the palmitate binding protein was a lipoprotein. Two-dimensional electrophoresis showed that this palmitate binding band was composed of three proteins with M(r) of 11, 30, and 42 kDa, without any trace of material at approximately 65 kDa, the mass of albumin. N-terminal sequencing of the palmitate binding band gave a major sequence of DAAQPSQELR-, indicating a high degree of homology to apolipoprotein A-I (apo-AI), the major apolipoprotein of high density lipoprotein (HDL). N-terminal sequencing of the major nickel binding band produced a sequence with no homology to albumin. When ultracentrifugation was used to isolate the lipoproteins from Antarctic toothfish plasma, the palmitate binding protein was found solely in the lipoprotein fraction. In competitive binding experiments, added human albumin did not prevent palmitate binding to toothfish HDL. In conclusion, there is no evidence for albumin in Antarctic toothfish plasma and HDL assumes the role of fatty acid transport.