Landscape Zonation, benefit functions and target-based planning: Unifying reserve selection strategies

The most widespread reserve selection strategy is target-based planning, as specified under the framework of systematic conservation planning. Targets are given for the representation levels of biodiversity features, and site selection algorithms are employed to either meet the targets with least cost (the minimum set formulation) or to maximize the number of targets met with a given resource (maximum coverage). Benefit functions are another recent approach to reserve selection. In the benefit function framework the objective is to maximize the value of the reserve network, however value is defined. In one benefit function formulation value is a sum over species-specific values, and species-specific value is an increasing function of representation. This benefit function approach is computationally convenient, but because it allows free tradeoffs between species, it essentially makes the assumption that species are acting as surrogates, or samples from a larger regional species pool. The Zonation algorithm is a recent computational method that produces a hierarchy of conservation priority through the landscape. This hierarchy is produced via iterative removal of selection units (cells) using the criterion of least marginal loss of conservation value to decide which cell to remove next. The first variant of Zonation, here called core-area Zonation, has a characteristic of emphasizing core-areas of all species. Here I separate the Zonation meta-algorithm from the cell removal rule, the definition of marginal loss of conservation value utilized inside the algorithm. I show how additive benefit functions and target-based planning can be implemented into the Zonation framework via the use of particular kinds of cell removal rules. The core-area, additive benefit function and targeting benefit function variants of Zonation have interesting conceptual differences in how they treat and trade off between species in the planning process.     

抗球虫药物残留的免疫检测技术

抗球虫药物在畜禽业应用广泛,可预防治疗球虫病,提高家禽饲料转化率,提升肉品质。但是,随即会出现饲料交叉污染,对非目标动物产生毒性作用,动物性食品中药物残留超标等问题。因此,建立简便、快速、灵敏度高的检测方法检测动物源性食品中的抗球虫药物残留极为重要。基于抗原-抗体特异性结合原理的免疫分析检测技术能够完成快速检测,高通量筛选,具有特异性强、灵敏度高、操作简便、成本低的优点。本文综述了不同基质中抗球虫药物残留的免疫检测技术进展,重点介绍了酶联免疫吸附检测法、免疫层析法、荧光偏振免疫分析检测法、时间分辨荧光免疫分析检测法和生物传感器检测法。并对免疫检测技术在残留检测方面的发展趋势进行了展望,旨在为抗球虫药物的残留监控提供方法学上的参考,为新方法的建立提供思路。     

犬慢性肾衰竭进程中肠道菌群代谢物短链脂肪酸水平的变化及其对肾功能的影响

本研究旨在评估短链脂肪酸在慢性肾衰竭患犬和健康犬中的水平,探究短链脂肪酸变化的原因及其对肾功能的影响。选取22例轻度慢性肾衰患犬（M-CRF组）、29例重度慢性肾衰患犬（S-CRF组）和26例健康对照犬（HC组）,用16S rDNA测序技术分析肠道菌群多样性,气相色谱法检测粪中短链脂肪酸浓度。通过粪菌移植和补充丁酸钠给5/6肾摘除犬,观察肠道菌群及丁酸钠对肾功能影响。结果显示：1）S-CRF组肠道菌群多样性指标观察物种数及Simpson指数低于HC组（P<0.05）,PCoA分析显示,S-CRF组肠道菌群与M-CRF、HC组有差异。2）LEfSe分析显示,S-CRF组和HC组间大量差异菌群,拟杆菌科、拟杆菌属及假单胞菌科等7个菌种富集于S-CRF组,普氏杆菌科、梭菌科、普氏杆菌属及普拉梭菌属等11个菌种富集于HC组。CCA分析发现富集于S-CRF组菌种丰度与肾功能指标呈正相关。3）S-CRF组粪中乙酸、丙酸及丁酸浓度均显著低于HC组和M-CRF组,M-CRF组丁酸浓度显著低于HC组（P<0.05）,且丁酸浓度与血中胱抑素C（Cys-c）、肌酐（Cr）及尿素氮（BUN）等肾功能指标呈负相关（r值分别为-0.451、-0.583和-0.514,P<0.01）。4）与慢性肾衰模型组（5/6 Nx组）比较,慢性肾衰犬给与丁酸钠8周后,血清Cr和BUN显著降低（P<0.05）;粪菌移植8周后,血清Cr和BUN显著升高（P<0.05）,丁酸钠可回调血清Cr和BUN水平。综上表明,慢性肾衰竭患犬肠道菌群多样性降低,菌群结构及丰度改变,粪中短链脂肪酸浓度降低,这些变化可加剧肾功能障碍。为犬慢性肾衰竭的防治提供新的理论依据。     

中华蜜蜂囊状幼虫病毒检测方法研究进展

中蜂囊状幼虫病是一种由中蜂囊状幼虫病毒引起的严重威胁中蜂健康的传染性疾病。目前由于该病尚无有效的药物治疗方式,因此,预防与及时检测对于遏制该病传播显得尤为重要。本文主要从临床诊断、分子生物学和免疫学方面总结中蜂囊状幼虫病检测与鉴定的方法,包括形态诊断、RT-PCR技术、实时荧光定量PCR、巢式PCR、胶体金免疫快速诊断技术、ELISA、血清学技术和基因芯片等,为中蜂囊状幼虫病毒检测方法的改进和优化提供参考。     

法氏囊活性肽BP7调节鸡未成熟B细胞的基因表达谱及功能分析

试验旨在探索法氏囊活性肽BP7调节鸡未成熟B细胞的分子基础。利用BP7刺激禽前B淋巴细胞DT40细胞,采用荧光定量PCR(qPCR)检测IgM的mRNA水平,并采用基因芯片分析基因表达谱及其生物学功能。结果显示,BP7刺激的DT40细胞产生IgM的mRNA水平明显升高。基因芯片分析发现,BP7处理的DT40细胞中共有1345个差异表达基因。通路分析发现,BP7诱导DT40细胞的差异表达基因涉及17条通路,包括受体互作、信号通路、代谢和蛋白质分解相关通路等。通路网络分析发现,细胞因子-细胞因子受体互作是BP7刺激后DT40细胞相关途径中的关键通路。基因本体论(GO)功能分析发现,BP7刺激DT40细胞中涉及的免疫相关功能主要包括免疫应答、免疫应答信号、Th1型免疫应答、细胞因子的产生和调节及其受体活性等方面。该研究阐述了法氏囊活性肽BP7调节禽未成熟B细胞的分子基础,为进一步研究法氏囊活性肽调控B细胞分化的分子机制提供了新的数据。     

Evaluation of left ventricular function with cardiac magnetic resonance imaging and echocardiography after administration of dobutamine and esmolol in healthy beagle dogs

Unlike echocardiography, cardiac magnetic resonance imaging (cardiac MRI) results in a near-exact assessment of cardiac structures and function. However, most veterinary studies have focused on dogs with normal cardiac function. We hypothesized that there would be significant differences in cardiac measurements between cardiac MRI and echocardiography when left ventricular (LV) function was abnormal. This study was undertaken to compare measurements of LV function produced by cardiac MRI and echocardiography in dogs whose LV function was altered by pharmacological agents. This study was conducted with six healthy beagle dogs. We increased left ventricular contractility by administration of dobutamine; we decreased cardiac contractility with esmolol. Stroke volume measurements were made by using both cardiac MRI and echocardiography under seven different conditions with general anesthesia: control, three doses of esmolol (100, 200, and 500 µg/kg/min), and three doses of dobutamine (10, 20, and 50 µg/kg/min). Experiments involving each condition were conducted at least 1 week apart. When LV contractility was normal, ejection fraction (EF) and stroke volume (SV), as measured by echocardiography and cardiac MRI, were not significantly different. However, when contractility was changed by pharmacological agents, EF and SV were overestimated by echocardiography, compared to MRI. Evaluation of cardiac function in patients treated with pharmacological agents should be conducted carefully because EF and SV measured by echocardiography can be overestimated, compared with EF and SV obtained by cardiac MRI.     

Effects of dietary Bacillus coagulans and yeast hydrolysate supplementation on growth performance,immune response and intestinal barrier function in weaned piglets

The present study investigated the effects of Bacillus coagulans and yeast hydrolysate supplementation on growth performance, immune response and intestinal barrier function of weaned piglets. Twenty-four weaned piglets with an average body weight (BW) of 6.89 ± 0.15 kg were divided into four diets for 28 days. The treatments were basal diet (control), basal diet supplemented with antibiotic (20 mg/kg colistin sulphate and 40 mg/kg bacitracin zinc, AT), probiotics (400 mg/kg Bacillus coagulans ≥5 × 109 CFU/g, BC) or yeast hydrolysate (5000 mg/kg yeast hydrolysate, YH). Average daily gain (ADG) and average daily feed intake (ADFI) were improved by AT and YH diets (p < 0.05), while BC diet only increased ADG (p < 0.05). The complement 3 (C3), lysozyme (LZM) and tumour necrosis factor-α (TNF-α) concentrations in serum were increased in BC diet (p < 0.05). Feeding AT and YH caused the increase of jejunal villus height (p < 0.05), and a higher ratio of villus height/crypt depth was observed in AT, BC and YH groups (p < 0.05). The mRNA expression of zonula occludens-1 (ZO-1) in jejunal mucosa was up-regulated by AT, BC and YH diets (p < 0.05). Dietary AT, BC or YH inclusion decreased the interleukin-1β (IL-1β) concentration and TNF-α mRNA expression (p < 0.05), and YH supplementation even down-regulated toll-like receptor 4 (TLR4) and CD14 expressions (p < 0.05). In summary, the dietary administration of BC or YH both improves growth performance through promoting the intestinal barrier function, indicating both of them can serve as potential alternatives to antibiotics growth promoters for the piglet production.     

复方中草药对猪生长性能、屠宰性能、肉品质和免疫功能的影响

试验旨在研究复方中草药对猪生长性能、屠宰性能、肉品质和免疫功能的影响。将60头育肥猪随机分成4组,每组15头猪。对照组、Ⅰ组、Ⅱ组、Ⅲ组分别在基础日粮中添加0、0.5%、1.0%、2.0%的复方中草药。结果显示:与对照组相比,Ⅰ组育肥猪平均日增重、血清免疫球蛋白G(IgG)含量均显著提高(P<0.05),失水率显著降低(P<0.05)。与对照组相比,Ⅱ组、Ⅲ组育肥猪末重、平均日增重、胴体重、胴体斜长、熟肉率、脾脏指数、血清免疫球蛋白A (IgA)含量、IgG含量均显著提高(P<0.05),料重比、背膘厚、剪切力、失水率均显著降低(P<0.05)。与Ⅰ组相比,Ⅱ组、Ⅲ组育肥猪胴体重、胴体斜长、血清IgG含量均显著提高(P<0.05),背膘厚均显著降低(P<0.05)。研究表明,育肥猪基础饲粮中添加1.0%和2.0%的该复方中草药制剂均能改善育肥猪的生长性能、屠宰性能、肉品质和免疫功能,临床应用中选择1.0%作为最适添加剂量。     

2020年底各地新玉米霉菌毒素风险分析

为了解呕吐毒素（DON）、玉米赤霉烯酮（ZEN）和黄曲霉毒素B1（AFB1）在2020年底新玉米中的污染情况,指导饲料生产企业和养殖场（户）开展霉菌毒素防控,降低霉菌毒素对饲料质量安全及养殖动物的影响,避免经济受损的风险。2020年12月在市场上采集新玉米样本225份,采用胶体金免疫层析法或上转发光免疫分析法对其霉菌毒素污染情况进行检测,依据安佑集团相关企业标准标和GB 13078-2017《饲料卫生标准》进行判定分析。结果表明：新玉米中霉菌毒素检出率为96.0%,其中DON、ZEN和AFB1的检出率分别为85.8%、87.1%和86.7%|DON、ZEN和AFB1在新玉米中的污染状况差别较大,按《饲料卫生标准》判定的超标率分别为0.0%、0.4%和11.6%|最大检测值分别为2500、534 μg/kg和＞100 μg/kg。就产地而言,山西、内蒙古、东北、安徽、山东、河南、云南、陕西等地霉菌毒素污染较重。综上,与2019年及2020年玉米霉菌毒素污染调查数据相比,2020年底新玉米污染程度较重。 [关键词] 玉米|霉菌毒素|胶体金免疫层析法|上转发光免疫分析法|污染规律     

黄粉虫、小麦胚芽对初产蛋鸡生产性能、蛋品质和抗氧化机能的影响

试验旨在研究饲粮中添加黄粉虫、小麦胚芽对初产蛋鸡生产性能、蛋品质、蛋黄和血清抗氧化指标的影响。选用20周龄产蛋率基本一致且健康的京红蛋鸡560只,随机分为7组,每组4个重复,每个重复20只鸡;采用双因子试验设计,3个黄粉虫水平(0.5%、1.0%、2.0%)×2个小麦胚芽水平(1%、2%)。试验期为8周,其中预试期1周,正试期7周。结果显示:①黄粉虫和小麦胚芽对初产蛋鸡的蛋壳厚度、蛋黄颜色以及血清和蛋黄总抗氧化能力(T-AOC)活力、丙二醛(MDA)含量存在显著交互作用(P<0.05)。②在饲粮中添加黄粉虫对产蛋率、日采食量和料蛋比没有产生影响(P>0.05);对蛋重、蛋黄重、蛋壳厚度、哈氏单位和蛋黄颜色无影响(P>0.05),但能显著提高蛋壳强度(P<0.05);显著提高血清超氧化物歧化酶(SOD)活力、降低血清和蛋黄MDA含量(P<0.05),对蛋黄和血清的谷胱甘肽过氧物酶(GSH-Px)活力、T-AOC活力无显著影响(P>0.05)。③在饲粮中添加小麦胚芽对生产性能、蛋品质以及血清和蛋黄的抗氧化指标均无影响(P>0.05)。综合分析,黄粉虫和小麦胚芽协同提高初产蛋鸡的蛋品质和抗氧化能力,其中以同时添加2.0%黄粉虫和1.0%小麦胚芽的效果较好。