Effects of 2 training methods on stress-related behaviors of the dog (Canis familiaris) and on the dog–owner relationship

Instrumental learning plays an important role in dog–human interactions. The recent demand for pet dog training has resulted in the development of various training methods. The present exploratory study aims to compare the effects of 2 training methods on both the behavioral welfare of the dog and the dog–owner relationship: the first method is based on positive reinforcement (appearance of an appetitive stimulus), whereas the second method is based on negative reinforcement (disappearance of an aversive stimulus). The study compared behaviors linked to signs of stress and attentive behaviors toward the owner in 2 dog training schools, which used different methods. Walking on-leash activity and obeying the “sit” command were studied. The results show that dogs from the school using a negative reinforcement–based method demonstrated lowered body postures and signals of stress, whereas dogs from the school using a positive reinforcement–based method showed increased attentiveness toward their owner. However, neither method affected avoidance behaviors. This exploratory study reveals the differential effects of the 2 training methods on dogs' behaviors; it suggests that training methods based on positive reinforcement are less stressful and potentially better for their welfare.     

牙鲆"鲆优2号"不同养殖地点生长和存活性状的基因型与环境互作分析

为比较牙鲆"鲆优2号"在不同养殖地区的生长和存活性能,实验利用连续多代对生长性状和抗迟缓爱德华氏菌病性状遗传参数评估和基因组选择的结果筛选出的亲本,建立28个"鲆优2号"家系,在河北(Site 1)和山东(Site 2)进行对比养殖试验,利用混合线性动物模型对生长和存活性状进行了基因型与环境互作分析。Site 1和Site 2的平均日增重分别为1.5和1.2 g/d,养殖成活率分别为81.4%和82.2%,"鲆优2号"在两个养殖地点的生长和抗病性能均表现优异。不同养殖环境间收获体质量和存活性状的遗传相关分别为0.57(<0.7)和0.82(>0.7),说明不同养殖环境间收获体质量存在显著的基因型与环境互作效应,但是不同养殖环境间存活性状的基因型与环境互作效应不显著。研究表明,牙鲆"鲆优2号"新品种在不同养殖地点的生长和存活性能均表现良好,为保证良好的推广效果,需要对牙鲆的制种方案进一步优化,针对不同的养殖地区进行"鲆优2号"苗种生产,或培育具有普适性的"鲆优2号"苗种,保证在不同养殖环境下的快速生长和高存活率优势。     

稻瘟病菌MoYpt5蛋白互作网络预测

稻瘟病菌(Magnaporthe oryzae)共有11个假定的Rab蛋白家族成员,本文选取了MoYpt51(MGG_06241)和MoYpt52(MGG_01185)进行了生物信息学分析。通过搜索多个大型蛋白互作数据库和文献,共得到数百个与核心蛋白互作的蛋白和互作对。利用信息处理技术和高效制图平台将这些蛋白互作对构建成互作网络,得到若干个具有生物学意义的模块。结果表明,筛选得到的互作蛋白中,有的参与了蛋白降解的泛素途径(MGG_04053等)、囊泡介导的蛋白胞内运输(MGG_01238等),有的在蛋白、染色体的组装和修饰等过程(MGG_03677等)起重要作用。大部分假定互作蛋白定位于细胞质和质膜上,为其与目标蛋白互作提供了空间可能性。     

Effects of N and K fertilizers on durum wheat quality in different environments

Eight genotypes from two different genetic pools (high yielding varieties and landraces) were assessed for grain yield (GY) and for five quality traits: protein content (P), thousand kernel weight (TKW), yellow berry (YB), gluten content (G_c) and gluten index (G_i) in sub-humid and semi-arid areas using four combinations of nitrogen and potassium fertilizers during two cropping seasons. Genotype × Environment × Fertilizers (G × E × F) was significant only for protein content (p < 0.05); and E × F was found significant (p < 0.05) for all parameters. Greater quality related traits expression was noted in the semi-arid areas for both genetic pools. Excessive rainfall in semi-arid areas resulted in gluten elasticity reduction. N-fertilizers seemed to enhance protein content and to reduce thousand kernel weight. K-fertilizer, might enhance the increase in both proteins and thousand kernel weight in favorable growing conditions of water availability. Semolina yielding ability was higher in landraces as compared to high yielding varieties particularly using recommended fertilizer management. This group of cultivars showed superiority over high yielding cultivars for quantitative quality parameters.     

Bis(2,3-dibromo-4,5-dihydroxybenzyl) Ether,a Marine Algae Derived Bromophenol,Inhibits the Growth of Botrytis cinerea and Interacts with DNA Molecules

Bis(2,3-dibromo-4,5-dihydroxybenzyl) ether (BDDE) is a bromophenol isolated from marine algae. Previous reports have shown that BDDE possesses cytotoxic and antibacterial activity. In the present study, we demonstrate that BDDE displays broad-spectrum antifungal activities, especially on Botrytis cinerea. BDDE inhibits the growth of B. cinerea cultured on a solid medium of potato dextrose agar (PDA) as well as on the potato dextrose broth (PDB) medium. Moreover, BDDE decreases the incidence of fruit decay and severity of strawberries infected with B. cinerea. Further studies have revealed that BDDE decreases the germination rate and inhibits the mycelial growth of B. cinerea. The inhibition mechanisms are related to the disruption of the cell membrane integrity in B. cinerea spores and newly formed germ tubes. This study also suggests that BDDE possibly interacts with DNA via intercalation and minor groove binding. The studies provide evidence that BDDE has potential application in the control of gray mold after fruit harvest and the compound could serve as a candidate or lead template for rational drug design and for the development of antifungal agents.     

二苯-α-吡喃酮类链格孢霉毒素和人血清白蛋白的相互作用及机理探究

为探究链格孢酚单甲醚(AME)和链格孢酚(AOH)这两种二苯-α-吡喃酮类链格孢霉毒素与人血清白蛋白(HSA)之间的分子相互作用及机理,本研究模拟血液生理pH值,采用稳态荧光光谱、同步荧光光谱、3D荧光光谱以及圆二色光谱等方法研究两者之间的相互作用。结果表明,AME和AOH与HSA相互作用均发生了静态猝灭,具有较高亲和力,以氢键和范德华力(ΔH<0,ΔS<0)结合形成1:1复合物,互作过程中这两种类毒素破坏了人血清白蛋白中稳定二级结构的氢键网络,使蛋白二级结构展开,且AME和AOH使人血清白蛋白中的α-螺旋结构含量从48.93%分别减少至39.41%和44.01%,并使色氨酸残基极性降低、疏水性增加,但酪氨酸残基极性变化不大,即结合位点可能位于色氨酸残基所在的空腔(即结合位点I);AME对HSA的猝灭程度、猝灭常数(K_sv)及结合常数(K_a)均大于AOH,结合距离也更小(r_AME=2.56 nmAOH=2.60 nm)。本研究结果为进一步探究二苯-α-吡喃酮类链格孢霉毒素的毒代动力学和药代动力学,完善丰富其毒理学相关资料,以及进行风险评估和在食品中限量标准的制定提供了参考依据。     

施氮量与密度对西南地区主栽青贮玉米品种产量和品质的影响

以试验前期筛选适合西南地区高产优质青贮玉米品种为研究对象,采用再裂区试验设计,分别在两年三地进行试验,探究氮肥、密度、环境及其互作对青贮干物质产量、品质的影响。2018年结果表明,减氮施肥能替代传统施肥,干物质产量随施氮量的减少先增加后降低,随密度的增加逐渐升高。2019年在雅安和合川试点,减氮10%和 30%与常规施氮(纯氮 300 kg/hm²)相比,各品种干物质产量随密度增加先升高后降低,在密度 82 500株/hm²时产量最高;在怀化试点,减氮 10%处理下的干物质产量显著高于常规施氮和减氮 30%处理,干物质产量随密度增加而增加。氮密互作对青贮玉米品质影响不明显。综合分析两年干物质产量及品质,在种植密度 71 250～82500株/hm²搭配减氮 10%～30%时,青贮玉米产量达到最高且品质没有降低或降低不显著。     

水稻可溶性淀粉合成酶基因SSⅡa和SSⅢa的功能、等位变异及其互作研究进展

水稻淀粉合成对稻米品质的影响研究一直备受关注,是水稻基础科学研究的热点和难点之一。淀粉合成途径受众多酶催化调控,可溶性淀粉合成酶(soluble starch synthase, SSS)是其中较重要的一种,极大地影响稻米食味品质的形成。可溶性淀粉合成酶基因SSⅡa和SSⅢa是控制稻米糊化温度和胚乳支链淀粉生物合成途径中的两个关键基因。本文重点回顾并归纳了国内外关于SSⅡa和SSⅢa基因的功能、等位变异及其互作对稻米蒸煮食味品质影响的最新研究进展,同时对SSⅡa和SSⅢa基因的育种利用前景进行了展望,以期为稻米品质分子改良和育种提供参考依据。     

TaJAZ7D蛋白在冬小麦JA抗寒途径中的作用

转录抑制因子JAZ（Jasmonate ZIM-domain）蛋白是茉莉酸（Jasmonate,JA）信号转导途径的核心元件,前人研究发现,拟南芥中AtJAZ1、AtJAZ4与AtICE1蛋白互作可抑制 AtICE1基因的转录,负调控拟南芥的抗寒性,然而小麦中TaJAZ与TaICE蛋白的互作调控机制尚不清楚。本研究以强抗寒冬小麦品种东农冬麦1号（Dn1）为试验材料,以与拟南芥AtJAZ1、AtJAZ4蛋白高度同源的TaJAZ7、TaJAZ12蛋白为对象,检测外源茉莉酸甲酯（MeJA）对低温胁迫下 TaJAZ7、 TaJAZ12基因表达量的影响。结果发现, TaJAZ7基因的表达量与温度变化呈明显负相关,故对TaJAZ7(以TaJAZ7D为研究对象进行后续研究)蛋白进行生物信息学分析和亚细胞定位,并利用酵母双杂交技术验证TaJAZ7D蛋白与TaMYC2和TaICE41蛋白的互作。生物信息学分析表明, TaJAZ7D基因编码区序列全长为633 bp,为不稳定的亲水性混合型蛋白;TaJAZ7D蛋白有典型的TIFY和Jas结构域,属于TIFY家族。亚细胞定位发现,TaJAZ7D蛋白位于细胞核中。酵母双杂交验证试验发现,TaJAZ7D蛋白与TaMYC2和TaICE41蛋白分别存在互作关系。     

Circular Disc Blade Considerations in Soil Force Prediction Modelling

Previous soil-disc force prediction models have considered spherical and concave blades, as used on disc ploughs and harrows, with many simplifying assumptions. This study proposes an approach applying the fundamental equation of earth moving mechanics for calculating the soil passive reaction acting on a rotating fiat disc blade as used on a zero-till single disc seeder. The study considers the effects of disc variable depth of cut, sweep and tilt angles, free rotation and a scrubbing reaction at the beveled edge. This paper outlines the modeling approach and prediction results for a fixed circular blade operating at 90° sweep angle over a range of speeds and at two tilt angles. To account for the varying depth across the circular disc shape width, elemental wide blade force reactions acting on wide blade segments of elemental width were integrated across the disc working width. By including inertia forces due to speed as well as additional bulldozing forces due to the loose soil accumulation in front of the blade the draught and upward vertical forces acting on the vertical disc blade were predicted with a deviation of 6%-19% and 1.5%-14% from measured data, respectively. The model was able to predict the effect of increasing the tilt angle from 0° to 20° on reducing both draught and upward vertical forces. Further development and validation of the model will be described in subsequent papers, reflecting a step by step approach of increasing complexity to model a disc blade as used on a zero-till single disc seeding system.