Seasonality,habitat type and locality influenced bird assemblage structure in Nigeria

This is the first report of the avian assemblage in the study area of Dutse, Nigeria. In addition to recording bird species, the effects of season, dominant vegetation structure, locality and anthropogenic activities on bird abundance, species richness and diversity were investigated. Using the point transect method, 264 points on 48 km of transect were used to count birds between 06:30 and 11:00 from August 2015 to February 2016. A total of 122 bird species of 41 families were recorded. Highest bird species richness was recorded in Warwade, highest abundance in Model, and highest diversity in Malamawa. The dry season and woodland habitat showed higher bird species richness, abundance and diversity than the wet season and shrubland habitat. Tree density was more important in increasing bird abundance than shrub density. Small-scale anthropogenic activities and habitat modification, such as farming, grazing, wood removal and human interference did not appear to have impacted the birds; however, loss of high tree-density woodland habitats may pose a major threat to the bird community in Dutse. The presence of birds of concern in the area suggests the need for conservation efforts of avifauna and as well as the forested habitats in Dutse.     

Mechanism of killing of spores of Bacillus cereus and Bacillus megaterium by wet heat

Aims: To determine the mechanism of wet heat killing of spores of Bacillus cereus and Bacillus megaterium. Methods and Results: Bacillus cereus and B. megaterium spores wet heat‐killed 82–99% gave two bands on equilibrium density gradient centrifugation. The lighter band was absent from spores that were not heat‐treated and increased in intensity upon increased heating times. These spores lacked dipicolinic acid (DPA) were not viable, germinated minimally and had much denatured protein. The spores in the denser band had viabilities as low as 2% of starting spores but retained normal DPA levels and most germinated, albeit slowly. However, these largely dead spores outgrew poorly if at all and synthesized little or no ATP following germination. Conclusions: Wet heat treatment appears to kill spores of B. cereus and B. megaterium by denaturing one or more key proteins, as has been suggested for wet heat killing of Bacillus subtilis spores. Significance and Impact of the Study: This work provides further information on the mechanisms of killing of spores of Bacillus species by wet heat, the most common method for spore inactivation.     

Effects of Species, Density, Patch-type, and Season on Post-dispersal Seed Predation in a Puerto Rican Pasture1

An experimental study of seed removal of four woody species in an abandoned pasture revealed significant main effects of species, density (higher densities survived more than lower densities), and patch‐type (seeds under shrub patches survived more than in grass patches), but no effects of season. Rates of seed loss decreased with seed size across species. Significant interactions between species and density and between species and patch‐type were also observed.     

Impacts of nutritional technology on feeds offered to horses: A review of effects of processing on voluntary intake,digesta characteristics and feed utilisation

Advances in feed processing technology applied to diet systems for ruminant livestock have been used extensively in the equine feed industry. The translation of these technologies is an important area of interest for the feed processing industry servicing the various sectors of the equine industry such as feeds for the racing, meat, milk and urine production, as well as supplements for leisure horse use. However, there are few reviews examining impacts of feed processing technologies on the processes controlling voluntary intake or utilisation of processed feeds by horses. In this paper, some of the specific features of feeds and impacts of feed processing on factors controlling meal pattern, frequency and size, and digestive physiology will be addressed. Three main areas are examined in this review, being impacts of feed processing on processes of “information gathering” (sensory and nutritional knowledge) by the horse, eating behaviour of the horse offered processed feeds (notably issues of preference and control of short-term ingestion rate), and implications of constraints of digestive physiology, process and function on voluntary intake and digestibility of processed feeds. The review highlights areas of future research and development for nutritional technology to increase knowledge of interactions between equine physiology and feed processing to enhance efficiency of capture of nutrients and maintain the welfare of horses managed in the housed environment.     

The therapeutic exception: abortion, sterilization and medical necessity in Costa Rica

Based on the case of Rosa, a nine-year-old girl who was denied a therapeutic abortion, this article analyzes the role played by the social in medical practice. For that purpose, it compares the different application of two similar pieces of legislation in Costa Rica, where both the practice of abortion and sterilization are restricted to the protection of health and life by the Penal Code. As a concept subject to interpretation, a broad conception of medical necessity could enable an ample use of the therapeutic exception and a liberal use of both surgeries. The practice of therapeutic sterilization has been generalized in Costa Rica and has become the legitimate way to distribute contraceptive sterilization. In contrast, therapeutic abortion is very rarely practiced. The analysis carried out proposes that it is the difference in social acceptance of abortion and sterilization that explains the different use that doctors, as gatekeepers of social morality, make of medical necessity.     

Foliar Extrafloral Nectar of Humboldtia brunonis (Fabaceae), a Paleotropic Ant‐plant,is Richer than Phloem Sap and More Attractive than Honeydew

The ant‐plant Humboldtia brunonis secretes extrafloral nectar (EFN) despite the lack of antiherbivore protection from most ants. EFN was richer in composition than phloem sap and honeydew from untended Hemiptera on the plant, suggesting that EFN could potentially distract ants from honeydew, since ants rarely tended Hemiptera on this plant.     

Implications of paper vs stainless steel biological indicator substrates for formaldehyde gas decontamination

Aims: This study was undertaken to determine the effectiveness of biological indicators currently being employed during formaldehyde decontamination. Data suggest that detectable amounts of formaldehyde are absorbed into the paper strips contained in currently used biological indicators. Absorbed formaldehyde has the potential to inhibit the growth of indicator spores, thus leading to false negative results. Indicators composed of either stainless steel carriers or paper strips were investigated to determine whether stainless steel carriers can be used as an alternative to paper strip indicators. Methods and Results: Biological indicators were exposed to formaldehyde gas and were tested for the presence of formaldehyde and any possible inhibition of spore growth. Absorbed formaldehyde was detected in the paper strip carriers while no formaldehyde was detected from any of the stainless steel carriers. Exposed paper strips were found to inhibit growth of up to 1 × 10⁶ spores while the stainless steel carriers did not inhibit the growth of spores. Conclusions: During decontamination, biological indicators composed of paper spore strips absorb formaldehyde and inhibit growth of any surviving spores. Stainless steel carriers do not absorb formaldehyde and are an ideal alternative substrate for biological indicators. Significance and Impact of the Study: The popular paper strip biological indicator can lead to false negative results during decontamination and is unsuitable for validating formaldehyde decontamination.     

大腹园蛛管状腺丝重组蛋白的克隆表达及纺丝

TuSp1蛋白(tubuliform spidroin 1)是管状腺丝(tubuliform silkfiber)的主要组成成分。管状腺丝作为蛛丝卵袋的外层包卵丝,其结构具有很好的耐腐蚀性和良好的力学性能。目前国内外对大腹园蛛TuSp1蛋白的研究很少,仅有一条基因序列的报道。本课题首次构建含大腹园蛛N端非重复结构域、重复单元以及C端非重复结构域的重组管状腺丝蛋白TuSp1 NT-Rp-CT,并经湿法纺丝获得重组蛋白丝纤维。重组蛋白液圆二色谱分析结果显示,pH由7. 0降低到5. 5的过程中,始终保持稳定的α-螺旋构象;重组蛋白丝纤维的傅里叶变换红外光谱结果显示,丝纤维中主要二级结构为β-折叠及β-转角;经扫描电镜观察发现,冻干的絮状重组蛋白能自组装成丝纤维,且表面光滑纤细;湿纺后的重组蛋白丝纤维直径较粗,但表面较平整均匀,具有类似天然管状腺丝的形态特征,这些为TuSp1蛋白的成丝机理及仿生纺丝研究提供了理论依据。     

培养基灭菌方式对细菌分离效率的影响

自然界蕴含大量未/难培养微生物,分离这些微生物对理论研究和资源开发具有重要意义。本研究使用高压灭菌和过滤除菌方式制备培养基,采用稀释涂布方法,从红树林灰泥样品中分离获得123株细菌,通过16S rRNA基因序列分析对其进行鉴定,进而探究培养基灭菌方式对细菌分离效果的影响。结果表明：过滤除菌培养基生长的单菌落数目（339±82）个显著多于高压灭菌培养基生长的单菌落数目（179±65）个;两种培养基分离细菌的群落结构在门、科和属分类水平上总体相似,但优势类群的数目和少数类群存在差异;过滤除菌培养基分离细菌的Shannon Wiener’s指数、均匀度、新种率、基因多样性均高于高压灭菌培养基,而其与近缘模式菌株相似度的平均值和中位数则低于高压灭菌培养基。因此,过滤除菌培养基分离获得细菌的多样性、均匀性和新颖性均高于高压灭菌培养基。本研究首次探究培养基灭菌方式对细菌分离效果的影响,具有更高分离效率的过滤除菌培养基为未/难培养微生物菌株资源获取提供了借鉴。