Heterologous Radioimmunoassay for Llama and Alpaca Luteinizing Hormone with a Monoclonal Antibody,an Equine Standard and a Human Tracer

A radioimmunoassay for llama and alpaca LH was developed using a human I¹²⁵LH tracer from a commercial kit, equine LH diluted in human LH free serum as standard, and a monoclonal antibody (518B7) specific for LH but with low species specificity. A 60-min delay in the addition of the tracer and overnight incubation gave a sensitivity of 0.8 μg L⁻¹. The intra-assay coefficient of variation was 37% at 1 μg L⁻¹, declined to 15% at 4 pg L⁻¹ and was below 6% for concentrations up to 32 μg L⁻¹. The inter-assay coefficients of variation for 3 control samples were 20% (2.8 μg L⁻¹), 16% (7.1 μg L⁻¹) and 9.8% (19 μg L⁻¹). In an attempt to increase sensitivity, all tubes were preincubated for 4 h at room temperature before adding the tracer, and the sample volume was increased from 50 μL to 100 μL· (in the standard curve the increased volume was compensated for by human LH free serum). With this protocol, the assay sensitivity was 0.5 μg L⁻¹. The assay was validated clinically and demonstrated increased concentrations of LH after mating in llamas and alpacas. Furthermore, the assay was used to monitor LH responses to a single dose of GnRH in llamas (adult males and females at different ages).     

长豇豆和丝瓜美洲斑潜蝇防治指标研究

连续自然接虫研究表明,长豇豆和丝瓜开花结实期美洲斑潜蝇产量损失与幼虫密度关系分别符合上列方程：Ｙ＝－０．０１１３８＋０．０００３５Ｘ（ｒ＝０．９９５３）;Ｙ＝－０．００５５２７＋０．０００６１Ｘ（ｒ＝０．９６３４）。根据当前价格和防治费用等因素,得出两种蔬菜在开花结实期的美洲斑潜蝇幼虫防治指标分别为百株８８４－１０２９头和１７７２－１９４５头。     

土壤质地定名法及吸湿水与土壤粒级含量关系的研究

利用卡庆斯基制、美国制、中国制3种土粒分级标准对张家口葡萄产区的30个采样点进行土壤质地命名,并通过对比分析得出中国制是该区最适的土壤质地分类方法。现对吸湿水含量与土壤各粒级微粒百分含量的关系做了探测性研究,得出吸湿水和土壤中小于0.01 mm的粒径含量之间拟合曲线方程为:Y=20.272e0.207x,可根据此方程应用卡庆斯基制确定土壤质地;吸湿水和土壤中1~0.05 mm0、.05~0.002 mm粒径含量的拟合曲线方程分别为:y=22.018x2-105.323x+156.381,y=-18.304x2+86.495x-49.536,又可根据这2个方程利用美国制确定土壤质地名称。这些为用简易方法鉴定土壤质地类型提供科学依据。     

美洲水貂TYR基因编码蛋白结构及功能的生物信息学分析

为进一步探明美洲水貂酪氨酸酶(TYR)基因的结构和功能信息,对美洲水貂TYR基因编码蛋白进行生物信息学分析,同时构建TYR基因的系统发育树。结果表明:美洲水貂TYR基因共编码531个氨基酸,其编码产物为不稳定的亲水蛋白;二级结构主要以α-螺旋和无规卷曲为主,含有1个酪氨酸酶超家族结构域,存在信号肽、跨膜结构域和二硫键;该蛋白主要在内质网中发挥细胞被膜、运输和结合的作用,同时还通过信号转导在细胞内发挥其生物学作用;系统进化情况和动物分类学基本一致,美洲水貂TYR基因与雪貂、家犬的亲缘关系最近。美洲水貂TYR基因编码蛋白在生物进化中具有较强保守性,该基因结构和功能的分析为水貂TYR基因遗传特性的进一步研究奠定了基础。     

不同产地西洋参氨基酸种类及含量分析

为研究不同种植区西洋参氨基酸的含量和品质,按食品安全国家标准GB/T5009.124-2016,对加拿大多伦多市、陕西省留坝县、吉林省抚松县、山东省文登市来源的4 a生西洋参进行氨基酸种类和含量测定及对比分析。各产地西洋参均检测出17种氨基酸,其中含有人体必需的赖氨酸、蛋氨酸、异亮氨酸、苯丙氨酸、亮氨酸、苏氨酸、缬氨酸和半必需氨基酸精氨酸;含有蛋氨酸、亮氨酸、异亮氨酸、苯丙氨酸、赖氨酸、天冬氨酸、甘氨酸、谷氨酸和精氨酸等8种药用氨基酸。人体必需氨基酸及药用氨基酸含量对比分析结果表明,加拿大多伦多市来源西洋参的这两类氨基酸含量最高,分别为46.20 mg/g和61.93 mg/g,占总氨基酸含量的54.0%和72.3%,其次是陕西省留坝县来源的西洋参,分别为45.70 mg/g和61.63 mg/g,占总氨基酸含量的51.9%和70.0%。主成分分析及综合评价结果表明,从氨基酸含量及营养均衡性角度来看,陕西省留坝县西洋参是最接近原产地加拿大的西洋参。     

皇后黑李优良单株——隆丰1号黑李的选育

对皇后黑李、隆丰1号黑李的生物学特征和植物学特性进行观察记载;开展皇后黑李优良单株的选育,选出优良单株——隆丰1号黑李。     

北美的分级测试项目简介

本文介绍了北美的分级测试项目的背景,简要介绍了锯材应力赋值的历史以及促使锯材工业进行此项研究的原动力.     

Characterizing environmental and spatial variables associated with the incidental catch of olive ridley (Lepidochelys olivacea) in the Eastern Tropical Pacific purse‐seine fishery

In the Eastern Tropical Pacific (ETP), a region of high fishing activity, olive ridley (Lepidochelis olivacea) and other sea turtles are accidentally caught in fishing nets with tuna and other animals. To date, the interaction between fishing activity, ocean conditions and sea turtle incidental catch in the ETP has been described and quantified, but the factors leading to the interaction of olive ridleys and fishing activity are not well understood. This information is essential for the development of future management strategies that avoid bycatch and incidental captures of sea turtles. We used Generalized additive models (GAM) to analyze the relationship between olive ridley incidental catch per unit effort (iCPUE) in the ETP purse‐seine fisheries and environmental conditions, geographic extent and fishing set type (associated with dolphins, floating objects or in free‐swimming tuna schools). Our results suggest that water temperature, set type and geographic location (latitude, longitude and distance to nesting beaches) are the most important predictor variables to describe the probability of a capture event, with the highest iCPUE observed in sets made over floating objects. With the environmental predictors used, sea surface temperatures (SST) of 26–30°C and chlorophyll‐a (chl‐a) concentrations <0.36 mg m^?3 were associated with the highest probability of an incidental catch. Temporally, the highest probability of an incidental catch was observed in the second half of the year (June to December). Four regions were observed as high incidental catch hotspots: North and south of the equator between 0–10°N; 0–10°S and from 120 to 140°W; and along the Colombian coast and surrounding regions.     

Multi-scale use of lands providing anthropogenic resources by American Crows in an urbanizing landscape

The conversion of forests and farmlands to human settlements has negative impacts on many native species, but also provides resources that some species are able to exploit. American Crows (Corvus brachyrhynchos), one such exploiter, create concern due to their impact as nest predators, disease hosts, and cultural harbingers of evil. We used various measures of crow abundance and resource use to determine crows’ response to features of anthropogenic landscapes in the Puget Sound region of the United States. We examined land cover and land use composition at three spatial scales: study sites (up to 208 ha), crow home ranges within sites (18.1 ha), and local land cover (400 m²). At the study site and within-site scales crow abundance was strongly correlated with land cover providing anthropogenic resources. In particular, crows were associated with the amount of ‘maintained forest’ cover, and were more likely to use grass and shrub cover than forest or bare soil cover. Although crows did not show a generalized response to an edge variable, they exhibited greater use of patchy habitat created by human settlements than of native forests. Radio-tagged territorial adults used resources within their home ranges relatively evenly, suggesting resource selection had occurred at a larger spatial scale. The land conversion pattern of new suburban and exurban settlements creates the mix of impervious surfaces and maintained vegetation that crows use, and in our study area crow populations are expected to continue to increase. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.