Biochemical and morphological risk assessment of transgenic wheat with enhanced iron and zinc bioaccessibility

Decreased iron and zinc bioaccessibility, caused by the anti-nutrient phytic acid, is one of the leading reasons for micronutrient deficiency-related disorders. Biofortification of wheat with phytase gene to enhance iron and zinc bioaccessibility appears to be a fitting solution for this problem, especially in developing countries where most of the population belongs to the lower economic sector. However, societal views on crops, particularly crops that are genetically modified (GM) to express a new trait, needs to be changed. Risk assessment of GM crops can play a crucial role in fostering positive public perception, since it is imperative to ensure safety before allowing human consumption. The present study performed compositional and morphological risk assessment of T3 and T4 generations of phytase transgenic wheat by comparing their biochemical and morphological traits. Transgenic plants were analysed for their carbohydrate, protein, starch and phytic acid content along with iron bioaccessibility, zinc bioaccessibility and phytase enzyme activity. Morphological traits studied included plant height, seed number, seed weight and spike number. No significant differences were observed for carbohydrate, protein, starch content and for morphological traits; however, a significant increase was observed in phytase activity as well as iron and zinc bioaccessibility, which correlated with a significant decrease in phytic acid. These results demonstrate that phytase transgenic wheat is as native as local wheat varieties and can potentially increase iron and zinc bioaccessibility.     

基于点评估方法的两广地区番木瓜中农药残留膳食暴露风险研究

为评估两广地区番木瓜中主要农药的残留情况及其产生的风险,采集了广东、广西地区40个生产基地的番木瓜样品进行测试分析,研究其生产过程中使用的杀虫剂、杀菌剂、杀螨剂和植物生长调节剂等各种农药残留情况,并对我国不同人群的膳食暴露风险进行了评估。结果显示,40批次番木瓜中检出农药残留32批次;在检出的32份番木瓜样品中,检出率超过10%的有咪鲜胺、吡虫啉、多菌灵、啶虫脒和苯醚甲环唑5种农药,检出率分别为51.1%、21.5%、13.3%、11.1%、10.9%。采用点评估方法,选择检出率在10%以上的咪鲜胺、吡虫啉、多菌灵、啶虫脒和苯醚甲环唑,进行农药残留慢性膳食摄入风险（%ADI）评估、急性膳食摄入风险（%ARfD）评估,并进行不同消费人群暴露点评估。结果显示：检出的5种农药%ADI均低于100.00%,为0.00023%~0.0059%;%ARfD远低于100%,为0.50%~28.3%,5种农药的急性和慢性摄入风险均为儿童高于成年人,绝大多数女性的摄入风险高于男性;5种农药急性摄入风险均高于慢性摄入风险,风险水平由高到低为咪鲜胺>啶虫脒>苯醚甲环唑>多菌灵>吡虫啉,但点评估结果均远低于100%,说明通过食用番木瓜摄入的农药残留极其微量,不会对人体产生急性或慢性风险。     

黄淮海与环渤海设施蔬菜产区重金属累积特征和环境质量评价

黄淮海与环渤海设施蔬菜产区是全国蔬菜发展的六大优势产区之一。通过收集2011～2019年黄淮海与环渤海设施菜田重金属研究的文献数据,对该区域重金属污染和环境质量进行了统计分析。结果表明,黄淮海与环渤海设施蔬菜产区土壤重金属Cu、Zn、Cr、Ni、Pb、Cd、As和Hg的平均含量均低于温室蔬菜产地环境质量评价标准限量值。与各个省市土壤背景值相比,土壤出现了明显的Cu、Zn、Cd和Hg累积,Cr和As均没有出现累积。8种重金属元素单项污染指数范围在0.30～0.80,排序依次为:CdPbHg=NiZnCuAsCr,仅Cd处于警戒等级,其余重金属元素均处于清洁等级。8种重金属综合污染指数平均值为0.75,表明该区域重金属污染处于警戒水平,需采取相应的污染防控措施。     

山地电力架空线路运维质量的智能评估

山地电力架空线路大多沿山架设,穿越树竹林,周边的树竹生长缺陷引发短路故障频繁发生,造成用电客户的大量投诉,用户体验满意度下降,抢修抢险费用大幅度攀升,严重影响供电公司的信誉和售电收益.为了提升用电客户的满意度和供电公司的售电受益,采用主成分分析方法提取了山地电力架空线路通道运维质量的3个主要影响因素,它们分别是树竹生长缺陷数、缺陷的消除数和通道运维资金使用合理度.对树竹的生长规律建立一个预测模型,从而得到树竹生长缺陷数的一个预测,根据预测结果划拨架空线路所在供电所的运维资金,消除树竹生长的缺陷数,再用Logistic回归模型,构建架空线路通道运维质量智能评估模型,使供电公司对架空线路运维实现基于数据决策的模式,尽可能保证供电线路零故障运行.     

风险感知、保险认知与养殖户肉鸡保险购买意愿 ——基于肉鸡主产区的实证分析

风险管理是现代农业经营中的重要问题，随着农业市场化程度的加深，肉鸡产业面临着多种风险来源的冲击。农业保险作为有效的现代风险管理工具，在保障产业可持续发展、减少农户家庭收入波动方面发挥了重要作用。基于行为金融理论，利用江苏、安徽、山东、河南和辽宁5个肉鸡主产区的调研数据，运用有序Logit模型，分析风险感知与保险认知对养殖户保险购买意愿的影响，探讨两者间的交互影响机制。结果表明，尽管66.43%的农户认为肉鸡养殖保险在风险管控中的必要性较强，但86.43%的农户对保险内容的了解程度不高，仅有20.71%的农户具有强烈的保险购买意愿。生产风险感知对养殖户的保险购买意愿有促进作用。保险认知中，农户对保险重要性认知程度对其保险购买意愿有促进作用；农户对保险内容的了解程度对其保险购买意愿具有显著的抑制作用，主要由于当前肉鸡保险产品设计不合理，保险内容与农户需求不匹配，保险理赔效果不佳，对保险内容了解程度越高反而会降低农户的购买意愿。风险感知和保险认知间存在交互影响，即风险感知对农户保险购买意愿的提高效果会随着对保险重要性认知程度的提高而增强，随着对保险内容了解程度的提高而减弱。因此，政府应加强农户的风险管理教育与培训，提高其风险管理意识，同时完善和优化当前肉鸡保险的内容，使之与农户需求相匹配，并通过更广泛的宣传来提高养殖户对于肉鸡保险的认知，从而增强农户对保险的购买意愿。     

Evidence of clandestine harvest and failure of conservation policies for Argopecten purpuratus in the Rinconada Marine Reserve (Chile)

1. The study of Argopecten purpuratus reproduction, post‐larval settlement, stock size, and population size structure and shell growth was undertaken in the 2000s in the Rinconada marine reserve (Chile) to evaluate the effectiveness of scallop recruitment and self‐sustainability.
2. The results highlight strong seasonal and inter‐annual variations of environmental conditions and scallop gonadosomatic index, spat collection, benthic distribution, total abundance and population size structure.
3. The Von Bertalanffy growth parameters were L_∞ = 120.12 mm and K = 0.9681; commercial size would be reached in about 17.2 months in the bay. Substrate availability, meteorological conditions, hydrodynamics and illegal harvesting explain spatial and temporal variations in scallop distribution and abundance.
4. Recruitment strength depends on one main cohort from year to year. While recruitment made up 81% and 94% of total abundances in May 2002 and May 2003, respectively, there were no overall density‐dependent relationships between stock size and recruitment. Spawning asynchrony in the bay supports the hypothesis that multiple gamete releases form part of a reproductive strategy in response to environmental variability.
5. The massive disappearance of large‐sized scallops during the study periods was direct evidence of overfishing owing to clandestine harvesting within the marine reserve. The failure of current legislation, strategies and policies for scallop conservation requires new regulations to restore scallop stock size, maintain its reproductive performance and limit illegal harvesting in the Rinconada.
6. A scenario allowing harvesting regulated by stock‐dependent fishing quotas would more efficiently ensure stock recovery and self‐sustainability. The modalities of this new policy are discussed.

     

饲料脂肪水平对俄罗斯鲟幼鱼生长、血液生化指标及抗氧化性能的影响

以鱼油、豆油、亚麻籽油等比例混合,配成脂肪含量分别为5.45%(L1)、7.00%(L2)、10.44%(L3)、14.37%(L4)、16.34%(L5)、18.91%(L6)及20.15%(L7)的等氮饲料,饲喂俄罗斯鲟(Acipenser gueldenstaedtii)幼鱼[(6.20±0.02)g]8周。实验结果表明,L3组的终末体质量、增重率最大,但与L2组间无显著差异(P0.05),L3组的蛋白质效率显著高于其它组(P0.05),且饲料系数最低。L6和L7组终末体质量、增重率和蛋白质效率显著低于L2和L3组(P0.05)。将幼鱼的增重率与饲料脂肪水平进行回归分析,得出俄罗斯鲟幼鱼在饲料脂肪水平为10.69%时生长最佳。随着饲料脂肪水平的升高,各组鱼的肝体比和体粗脂肪有上升趋势,其中肝体比在饲料脂肪含量大于14.37%时显著增大(P0.05)。血清中的甘油三酯、胆固醇含量也随脂肪水平升高而显著提高(P0.05),提示脂肪过高会影响俄罗斯鲟幼鱼的生长,降低蛋白质效率,导致脂肪在体内的过量积蓄。L7组鱼血清中高密度脂蛋白胆固醇含量最高,而L1组鱼的低密度脂蛋白胆固醇含量最高。肝脏脂蛋白酯酶活性随饲料脂肪水平的提高而升高,脂肪酸合成酶活性则随脂肪水平升高而降低,提示饲料脂肪水平的提高会促进鱼体脂肪的分解代谢。肝脏丙二醛含量和超氧化物歧化酶活性均随着饲料脂肪水平的提高显著升高(P0.05),表明脂肪含量过高会导致脂质过氧化,引发机体抗氧化酶活性的升高。综合俄罗斯鲟幼鱼的生长、血液指标及抗氧化性能,建议生产中将幼鱼的饲料脂肪水平控制在7.00%~10.69%。     

A century of fishery data documenting the collapse of smooth‐hounds (Mustelus spp.) in the Mediterranean Sea

1. Conservation and management of shark populations is increasingly becoming important in many marine regions, since there is a growing body of evidence showing that several species are threatened and continuing to decline because of unregulated fishing. Quantifying the extent of sharks' decline, the risk of species extinction, and the consequences for marine ecosystems have been challenging and controversial, mostly due to data limitations.
2. In this study, more than one century of multiple‐sources of bibliographic records on presence and frequency of occurrence of three species of commercial sharks, the smooth‐hounds Mustelus spp., in the Mediterranean Sea were compiled and analysed. Generalized additive models for location, scale and shape (GAMLSS) were used to estimate the rate of change of two of these species, Mustelus mustelus and Mustelus punctulatus, in four Mediterranean regions.
3. Model results showed that smooth‐hounds have declined by 80–90% since the beginning of last century to almost disappear in a large part of their original distributional range during the 1980s and 1990s.
4. Based on modelling results, a revision of the current International Union for Conservation of Nature classification of Mediterranean smooth‐hounds would be advisable along with the application of urgent conservation measures.

     

重庆市荣昌区饮用水源地环境评估与管理对策

为保障城镇居民饮水安全,从水源地环境管理状况和水源地水质评价2个方面对环境状况进行评估。结果表明,虽然高升桥饮用水源地综合评估结果为优秀,水质状况较好,但在水源地管理方面仍存在较多问题。针对监测能力、监管能力不足和群众环保意识薄弱等问题,提出了相关对策。     

A stochastic surplus production model in continuous time

Surplus production modelling has a long history as a method for managing data‐limited fish stocks. Recent advancements have cast surplus production models as state‐space models that separate random variability of stock dynamics from error in observed indices of biomass. We present a stochastic surplus production model in continuous time (SPiCT), which in addition to stock dynamics also models the dynamics of the fisheries. This enables error in the catch process to be reflected in the uncertainty of estimated model parameters and management quantities. Benefits of the continuous‐time state‐space model formulation include the ability to provide estimates of exploitable biomass and fishing mortality at any point in time from data sampled at arbitrary and possibly irregular intervals. We show in a simulation that the ability to analyse subannual data can increase the effective sample size and improve estimation of reference points relative to discrete‐time analysis of aggregated annual data. Finally, subannual data from five North Sea stocks are analysed with particular focus on using residual analysis to diagnose model insufficiencies and identify necessary model extensions such as robust estimation and incorporation of seasonality. We argue that including all known sources of uncertainty, propagation of that uncertainty to reference points and checking of model assumptions using residuals are critical prerequisites to rigorous fish stock management based on surplus production models.