Functional constraints on nest characteristics of pebble mounds of breeding male hornyhead chub Nocomis biguttatus

Breeding male hornyhead chub Nocomis biguttatus constructed nests in areas with relatively high but less than maximum flow rate and greater than average water depth. Nests comprised c. 3000 pebbles for a total mass of 11 kg. Males selected pebbles of smaller diameter but higher density than pebbles in the immediate vicinity. Thus, nests balanced the risk of mound erosion and energetic cost of nest construction with the benefits of protection from egg predators and a stable internal flow rate for oxygenation. These data help establish environmental management goals for the conservation of N. biguttatus and the lotic ecosystems dependent upon them.     

选择性冠状静脉动脉化搭桥术中不同移植物的应用疗效比较

目的:对比选择性冠状静脉动脉化(SCVBG)搭桥治疗弥漫性右冠状动脉狭窄病变中选择乳内动脉和大隐静脉作为桥血管的治疗效果。方法:选择2008年10月到2014年10月在我院行SCVBG搭桥的84例患者资料,其中选择大隐静脉作为桥血管进行冠状静脉动脉化搭桥患者46例(大隐静脉桥组),选择乳内动脉作为桥血管进行冠状静脉动脉化搭桥患者38例(乳内动脉桥组)。随访记录两组患者的生存情况、近期复查超声心动图、冠状动脉CTA及心绞痛复发率。结果:乳内动脉桥组患者总生存率(100%)明显高于大隐静脉桥组(82.6%)(P0.05)。乳内动脉桥组患者桥血管和心中静脉通畅率(100%)明显大于大隐静脉桥组(54.35%)(P0.05)。两组患者左心室射血分数(LVEF)较治疗前明显增加,左心室舒张期末内径(LVEDD)较治疗前明显减小(P0.05)。治疗后,乳内动脉桥组患者心绞痛复发率明显小于大隐静脉桥组(P0.05)。结论:SCVBG搭桥治疗弥漫性右冠状动脉狭窄病变中,选择乳内动脉桥效果优于大隐静脉桥,能明显提高桥血管和心中静脉通畅率,降低心绞痛复发率。     

Legal constraints and opportunities for biochar: a case analysis of EU law

This article addresses biochar from a legal point of view. It analyses different policies and regulations from a European (Flemish) point of view and provides a first and general insight in what potential legal constraints the development of a biochar industry might face and what opportunities lie ahead. This is due to the fact that biochar is a recent product and a lot of scientific uncertainty still exists regarding the consequences of its application. From the analysis it appears a multitude of policies and legislative measures influence the development of the biochar industry. Hence, it is important that all these policies and legislative measures are analyzed in an appropriate manner. Moreover, considerable lobbying, negotiating and cooperation between different disciplines (legal, scientific, economical, etc.) will be required so as to develop a feasible and safe biochar framework.     

STRONG SELECTION GENOME‐WIDE ENHANCES FITNESS TRADE‐OFFS ACROSS ENVIRONMENTS AND EPISODES OF SELECTION

Fitness trade‐offs across episodes of selection and environments influence life‐history evolution and adaptive population divergence. Documenting these trade‐offs remains challenging as selection can vary in magnitude and direction through time and space. Here, we evaluate fitness trade‐offs at the levels of the whole organism and the quantitative trait locus (QTL) in a multiyear field study of Boechera stricta (Brassicaceae), a genetically tractable mustard native to the Rocky Mountains. Reciprocal local adaptation was pronounced for viability, but not for reproductive components of fitness. Instead, local genomes had a fecundity advantage only in the high latitude garden. By estimating realized selection coefficients from individual‐level data on viability and reproductive success and permuting the data to infer significance, we examined the genetic basis of fitness trade‐offs. This analytical approach (Conditional Neutrality‐Antagonistic Pleiotropy, CNAP) identified genetic trade‐offs at a flowering phenology QTL (costs of adaptation) and revealed genetic trade‐offs across fitness components (costs of reproduction). These patterns would not have emerged from traditional ANOVA‐based QTL mapping. Our analytical framework can be applied to other systems to investigate fitness trade‐offs. This task is becoming increasingly important as climate change may alter fitness landscapes, potentially disrupting fitness trade‐offs that took many generations to evolve.     

Selective separation and enrichment of peptides for MS analysis using the microspheres composed of Fe3O4@nSiO2 core and perpendicularly aligned mesoporous SiO2 shell

In this work, we report the development of a novel enrichment protocol for peptides by using the microspheres composed of Fe₃O₄@nSiO₂ Core and perpendicularly aligned mesoporous SiO₂ shell (designated Fe₃O₄@nSiO₂@mSiO₂). The Fe₃O₄@nSiO₂@mSiO₂ microspheres possess useful magnetic responsivity which makes the process of enrichment fast and convenient. The highly ordered nanoscale pores (2 nm) and high‐surface areas of the microspheres were demonstrated to have good size‐exclusion effect for the adsorption of peptides. An increase of S/N ratio over 100 times could be achieved by using the microspheres to enrich a standard peptide, and the application of the microspheres to enrich universal peptides was performed by using myoglobin tryptic digest solution. The enrichment efficiency of re‐used Fe₃O₄@nSiO₂@mSiO₂ microspheres was also studied. Large‐scale enrichment of endogenous peptides in rat brain extract was achieved by the microspheres. Automated nano‐LC‐ESI‐MS/MS was applied to analyze the sample after enrichment, and 60 unique peptides were identified in total. The facile and low‐cost synthesis as well as the convenient and efficient enrichment process of the novel Fe₃O₄@nSiO₂@mSiO₂ microspheres makes it a promising candidate for selectively isolation and enrichment of endogenous peptides from complex biological samples.     

Extracellular hydrophobic regions in scavenger receptor BI play a key role in mediating HDL-cholesterol transport

The binding of high density lipoprotein (HDL) to scavenger receptor BI (SR-BI) is responsible for whole-body cholesterol disposal via reverse cholesterol transport. The extracellular domain of SR-BI is required for HDL binding and selective uptake of HDL-cholesterol. We identified six highly hydrophobic regions in this domain that may be important for receptor activity and performed site-directed mutagenesis to investigate the importance of these regions in SR-BI-mediated cholesterol transport. Non-conservative mutation of the regions encompassing V67, L140/L142, V164 or V221 reduced hydrophobicity and impaired the ability of SR-BI to bind HDL, mediate selective uptake of HDL-cholesterol, promote cholesterol efflux, and enlarge the cholesterol oxidase-sensitive pool of membrane free cholesterol. In contrast, conservative mutations at V67, V164 or V221 did not affect the hydrophobicity or these cholesterol transport activities. We conclude that the hydrophobicity of N-terminal extracellular regions of SR-BI is critical for cholesterol transport, possibly by mediating receptor-ligand and/or receptor-membrane interactions.     

Coalescent Size Versus Coalescent Time with Strong Selection

This work studies the coalescent (ancestral pedigree, genealogy) of the entire population. The coalescent structure (topology) is robust, but selection changes the rate of coalescence (the time between branching events). The change in the rate of coalescence is not uniform, rather the reduction in the time between branching events is greatest when the coalescent is small (immediately after the common ancestor is the only member of the coalescent) with little change when the coalescent is large (immediately preceding when that common ancestor becomes fixed and the size of the coalescent is N). This provides that the reduction in the coalescent time due to selection is much greater than the reduction in the cumulative size of the coalescent (total number of ancestors of the present population after and including the most recent common ancestor) due to selection. If Ns≫1, the coalescent and fixation times are approximately equal to , which is much less than the value N which would result from neutral drift (N rather than the canonical haploid neutral fixation time 2N is the appropriate comparison for the model considered here), in particular, it is 70% less for Ns=10 and 95% less for Ns=100. However, for those values of Ns, and N ranging between 10³ and 10⁶, the reduction in the cumulative size of the coalescent of the entire population compared to the neutral case ranges from 17% to 65% (depending on the values of N and s). The coalescent time for two individuals for Ns of 10 and 100 is reduced by approximately 70% and 94%, respectively, compared with the neutral case. Because heterozygosity is proportional to the coalescent time for two individuals and the number of segregating alleles is proportional to the cumulative size of the coalescent, selection reduces heterozygosity more than it reduces the number of segregating alleles.     

A novel strategy for defining haplotypes by selective depletion using restriction enzymes

Various single nucleotide polymorphisms (SNPs) have been investigated regarding association with gene expression levels or human diseases. Although different SNPs within one gene are frequently analyzed individually, it is highly probable that in the majority of the cases, a precise combination of SNP alleles, i.e., haplotype, determines a functional trait. Methods commonly used for haplotype determination, involving studies in families, cloning, or somatic cell hybrids, are expensive and time-consuming. We herein suggest a novel and simple strategy for haplotype determination, involving selective haplotype depletion with a restriction enzyme, followed by sequencing. We studied 11 LTA gene polymorphisms in 102 Brazilian individuals, and we applied this novel methodology for haplotyping 67 out of 70 LTA heterozygous individuals. We concluded that the method is rapid and efficient, and, as it includes only simple and widespread-used techniques, it could be used in most of the laboratories without further investment in equipments. The wider usage of haplotyping could be important to clarify contradictory results frequently observed among studies that focus on a single SNP. Maria Gerbase-DeLima and Andrey Morgun are co-senior authors.     

When carnivores are “full and lazy”

Are animals usually hungry and busily looking for food, or do they often meet their energetic and other needs in the 24 h of a day? Focusing on carnivores, I provide evidence for the latter scenario. I develop a model that predicts the minimum food abundance at which a carnivore reaches satiation and is released from time constraints. Literature data from five invertebrate and vertebrate species suggest that food abundances experienced in the field often exceed this threshold. A comparison of energetic demands to kill rates also suggests that carnivores often reach satiation: for the 16 bird and mammal species analyzed, this frequency is 88% (average across species). Because pressure of time would likely lead to trade-offs in time allocation and thus to a nonsatiating food consumption, these results suggest that carnivores are often released from time constraints.