Estimation of Genetic Parameters for Live Weight in South African Holstein Cattle

Cow live weight is of economic importance in dairy production;however, it is not included in the selection objective for South African dairy cattle. Variance components estimates are a prerequisite to incorporating a trait in the breeding objective. Variance components were estimated for live weight of lactating Holstein cows on two South African dairy herds. Live weight records on 9843 lactating cows, collected over a period of three years, were used. An analysis of variance was carried out to determine fixed effects to include in the model by the least squares method, using the Generalised Linear Models procedure of the Statistical Analysis System. Variance components were estimated by the Restricted Maximum Likelihood procedure using the ASREML programme. A high heritability estimate of 0.74 ± 0.19 is found, which suggests that there is scope for significant response to selection on live weight in the South African Holstein cattle population. A repeatability estimate of 0.86 was obtained. These results form the basis for incorporating live weight in the breeding objective for South African Holstein cattle. Further work, however, needs to be done to develop estimates based on a representative sample of the whole population, as the current study is based on data from only two herds.

Graft-to-recipient weight ratio lower to 0.7% is safe without portal pressure modulation in right-lobe living donor liver transplantation with favorable conditions

BACKGROUND: The low graft-to-recipient weight ratio(GRWR) in adult-to-adult living donor liver transplantation(LDLT) is one of the major risk factors affecting graft survival. The goal of this study was to evaluate whether the lower limit of the GRWR can be safely reduced without portal pressure modulation in right-lobe LDLT. METHODS: From 2005 to 2011, 317 consecutive patients from a single institute underwent LDLT with right-lobe grafts without portal pressure modulation. Of these, 23 had a GRWR of less than 0.7%(group A), 27 had a GRWR of ≥0.7%, 【0.8%(group B), and 267 had a GRWR of more than and equal to 0.8%(group C). Medical records, including recipient, donor, operation factors, laboratory findings and complications were reviewed retrospectively. RESULTS: The baseline demographics showed low model for end-stage liver disease score(mean 16.3±8.9) and high percentage of hepatocellular carcinoma(231 patients, 72.9%). Three groups by GRWR demonstrated similar characteristics except recipient body mass index and donor gender. For smallforsize syndrome, there were 3(13.0%) in group A, 1(3.7%) in group B, and 2 patients(0.7%) in group C(P【0.001). Hepatic artery thrombosis was more frequently observed in group A than in groups B and C(8.7% vs 3.7% vs 1.9%, P=0.047). However, among the three groups, graft survival rates at 1 year(100% vs 96.3% vs 93.6%) and 3 years(91.7% vs 73.2% vs 88.1%) were not different(P=0.539). In laboratory measurements,there was no group difference in total bilirubin and albumin. However, prothrombin time was longer in group A within postoperative 1 week and platelet count was lower in groups A and B within postoperative 1 month. CONCLUSION: A GRWR lower to 0.7% is safe and does not need to modulate portal pressure in adult-to-adult LDLT using the right-lobe in favorable conditions including low model for end-stage liver disease score.

Living donor liver transplantation with body-weight more or less than 10 kilograms

AIM: To compare the outcomes of pediatric patients weighing less than or more than 10 kg who underwent liver transplantation.METHODS: Data for 196 pediatric patients who underwent living donor liver transplantation between June 1994 and February 2011 were reviewed retrospectively.The information for each patient was anonymized and de-identified before analysis. The data included information regarding the pre-transplant conditions, intraoperative fluid replacement and outcomes for each patient. The 196 patients were divided into two groups: those with body weights of less than 10 kg were included in group 1(G1; n =101), while those with body weights of more than 10 kg were included in group 2(G2; n = 95). For each group, the patients' ages, body weights, heights,pediatric end stage liver disease scores, anesthesia times, and warm and cold ischemic times were analyzed. In addition, between-group comparisons were also made. Mann-Whitney U tests were used to compare all the variables except for complications and survival rates, which were analyzed using χ 2 tests and Kaplan-Meier tests, respectively.RESULTS: The general medical conditions of the G1patients were worse than those of the G2 patients, as shown by the higher pediatric end stage liver disease scores and poorer Z-scores. In addition, the preoperative Hb and serum albumin levels were all lower for the G1 patients than for the G2 patients. The G1 patients also had significantly more intraoperative blood loss than the G2 patients. In addition, the intraoperative fluid requirements for the G1 patients,including leukocyte poor red blood cell transfusions,5% albumin infusions and crystalloid infusions, were significantly higher than those for the G2 patients. The risk of intraoperative portal vein thrombosis was higher for the patients in G1 than for those in G2. However,the one-year survival rates(95.9% and 96.8% for G1 and G2, respectively) and three-year survival rates(94.9% and 94.6% for G1 and G2, respectively) for both groups were similar.CONCLUSION: Patients weighing less than 10 kg typically have poorer conditions, but their survival rates are comparable to those of children weighing more than 10 kg.

保存时间对黑水虻幼虫体重和营养物质的影响

试验旨在阐明不同日龄黑水虻幼虫活体保存期间体重和营养物质的变化规律。试验选取10日龄、12日龄、14日龄幼虫各6 kg,每个龄期为1个处理,每个处理6个重复,每个重复1 kg,其中3个重复每天中午称量幼虫重量,用于测定体重损失;另外3个重复的幼虫在同样环境下存放,分别于第5、10、15、20天,每个重复取50 g幼虫称重,烘干后测定营养物质含量。结果显示:12日龄和14日龄幼虫鲜重第20天绝对损失均在50%左右。黑水虻幼虫活体保存15 d幼虫干物质含量显著高于保存5 d和10 d幼虫干物质含量(P<0.05);12日龄、14日龄黑水虻幼虫第10天和第20天粗蛋白含量高于第5天和初始幼虫粗蛋白含量(P<0.05),在保存第15天粗蛋白含量最高;14日龄幼虫初始粗脂肪含量显著高于其他阶段。保存时间与日龄具有交互作用,保存时间×日龄能显著影响黑水虻幼虫的粗脂肪、干物质含量(P<0.05)。本研究揭示了黑水虻活体保存期间幼虫体内营养物质变化规律和消耗程度,本试验条件下,10日龄黑水虻幼虫进行运输和鲜活保存,且保存时间10 d内能获得较高的营养物质。

中国乡村人居环境韧性评价及障碍因素分析

论文从乡村人居环境韧性内涵出发,构建乡村人居环境韧性评价指标体系,并将其转换为基于系统属性的乡村人居环境韧性评价指标体系,分析2010—2020年中国乡村人居环境韧性演变特征,识别中国乡村人居环境韧性障碍因素。研究结果表明:中国乡村人居环境韧性指数总体呈现波动上升态势,但各区域变动态势不尽相同,乡村人居环境韧性水平变动与经济发展格局基本一致。乡村人居环境不同子系统韧性呈现不同的变动态势,社会子系统韧性水平最高,经济子系统韧性水平最低,且呈现持续下滑态势。工程子系统韧性障碍度是乡村韧性水平提升的最主要障碍子系统,资源禀赋、农业生产、环境治理、居住条件和科技创新是中国乡村人居环境韧性提升的共同障碍要素。根据障碍度测算结果将中国各省份划分为环境治理与生态维护障碍型、资源禀赋与环境治理障碍型、居住条件与区域交通障碍型、农业生产条件与居住条件障碍型,并针对不同类型的特点提出不同的对策。

使用平均路径的一种新Live-wire算法

在传统Live-wire算法中,两个人工选定节点之间的最优路径被定义为具有最小累计能量的路径。因此传统live-wire算法在分割边缘转折剧烈的物体时,为了保证分割的正确性就需要人工添加较多的节点,从而增加整个分割过程的耗时。提出一种基于可控平均代价路径的新型Live-wire算法,并从理论上证明,传统live-wire算法其实是提出的新型算法的一种特例。实验表明,新型Live-wire算法与传统算法相比,能在保证精度的同时减少人工设定的节点个数,从而加快整个分割过程的速度。

星形多臂丁苯共聚物的分子结构设计与合成

以正丁基锂为引发剂、苯乙烯与丁二烯为单体、双四氢糠丙烷为极性结构调节剂、六氯乙硅烷为偶联剂,采用活性负离子聚合技术设计并合成了一系列具有星形结构的多臂丁苯共聚物(S-g-SSB-6)。使用凝胶渗透色谱分析了S-g-SSB-6的分子量及其分布、偶联臂数和偶联效率,使用旋转流变仪测试了S-g-SSB-6、以SiCl_(4)为偶联剂的星形多臂丁苯共聚物及线型结构丁苯共聚物(L-SSB)的流变性能,并考察了支链长度和支链柔顺性对S-g-SSB-6流变性能的影响。结果表明,S-g-SSB-6的偶联臂数达到4.1、偶联效率均大于80%;相同重均分子量下S-g-SSB-6的熔体黏度较L-SSB更低、流体流动性更好;当支化度相同时,S-g-SSB-6的熔体黏度随着单臂分子量和分子链刚性的增加而增大。

辽宁省“三生”功能时空演变及其碳排放效应

[目的]探究辽宁省“三生”功能时空演变及其碳排放效应,为“双碳”目标下的国土空间规划提供依据。[方法]基于土地利用多功能性分类识别辽宁省国土“三生”功能,结合直接和间接排放因子法核算碳排放量,探索“三生”功能与碳排放量空间关系及其时空分异性,揭示“三生”功能时空演变的碳排放效应。[结果]①2005—2020年辽宁省“三生”功能空间分布格局总体变化不大,大部分地区以生产和生态功能为主,生活功能区扩张明显,各地级市中心与周边区域空间差异明显。②2005—2013年,辽宁省各县域碳排放量增长迅速,2013—2020年增速缓慢,但空间差异愈发显著,碳排放高值明显集中在沈阳市和大连市。③辽宁省“三生”功能与碳排放量空间布局及数量变化的相关性总体较强,但空间差异明显且影响因素复杂。[结论]辽宁省各县域需要在自然地理条件约束和经济社会发展需求引导下,在明确各自土地主导功能定位的基础上,依托自身区域优势与资源禀赋,加强区域协作,以实现全域碳减排。

Experiences of Low Gestational Weight Gain: A Phenomenological Study with Pregnant Women

Low maternal, gestational weight gain is associated with preterm birth, intrauterine growth restriction, low birthweight, small-for-gestational-age infants, neural tube defects, infant death, failure to initiate breastfeeding, and childhood asthma. The advantage of qualitative research is it can provide valuable insights for health care professionals into the experience and perceptions of low gestational weight gain from the vantage point of women with first-hand lived experience. In this Heideggarian interpretive phenomenological study, the meaning and experiences of weight gain for pregnant women with low gestational weight gain were explored. Data were collected through interviews with 10 pregnant women from Atlantic Canada. Conroy’s pathway for interpretive phenomenology was utilized. A hermeneutical spiral of interpretation identified six patterns or major themes: confronting one’s mortality;defending oneself against a permanent metamorphosis into a stranger;playing with fire and brimstone;slipping under the radar;trying to find peace;and riding an emotional roller coaster. The findings point to a war that is being waged over pregnant bodies with respect to weight that leaves pregnant women fending for themselves, apparently with little help from their health care providers. Implications of the findings for health practice, education, and research are discussed.

“It’s a Wild Ride”: A Phenomenological Exploration of High Maternal, Gestational Weight Gain

High maternal, gestational weight gain is associated with high birthweight, large-for-gestational-age birthweights, cesarean delivery, child overweight, and short- and long-term postpartum weight retention. In this phenomenological study, the meaning and experiences of weight gain for pregnant women with high gestational weight gain were investigated. Data were collected through interviews with pregnant women from Atlantic Canada. van Manen’s method of phenomenology was utilized. The data analysis revealed four patterns or major themes: being caught off guard;losing your bearings;hanging on for dear life;and hoping for health. The participants experienced their gestational weight gain as an unexpected “wild ride” that they could not control. The findings highlight the need for health care professionals to provide pregnant women with more support concerning gestational weight gain.

Outcomes of adult patients adopting small-for-size grafts in living donor liver transplantation: A systematic review and meta-analysis

Background: Small-for-size graft(SFSG) has emerged as one of the very contentions in adult-to-adult living donor liver transplantation(LDLT) as a certain graft size is related to recipients’ prognosis. Graftto-recipient weight ratio(GRWR)≥0.8% was considered as a threshold to conduct LDLT. However, this also has been challenged over decades as a result of technique refinements. For a better understanding of SFSG in practice, we conducted this meta-analysis to compare the perioperative outcomes and long-term outcomes between patients adopting the grafts with a lower volume(GRWR < 0.8%, SFSG group) and sufficient volume(GRWR ≥ 0.8%, non-SFSG group) in adult-to-adult LDLT. Data sources: The studies comparing recipients adopting graft with a GRWR < 0.8% and ≥ 0.8% were searched by three authors independently in Pub Med, Web of Science, Embase, the Cochrane Library, MEDLINE and Google Scholar databases until September 2018 and data were analyzed by RevMan 5.3.5. Results: Sixteen studies with a total of 3272 subjects were included in this meta-analysis. In terms of small-for-size syndrome(SFSS), no significant difference was found in subjects enrolled after year 2010(before 2010, OR = 3.00, 95% CI: 1.69–5.35, P = 0.0002;after 2010, OR = 1.23, 95% CI: 0.79–1.90, P = 0.36;P for interaction: 0.02). There was no significant difference in operative duration, blood loss, cold ischemia time, biliary complications, acute rejection, postoperative bleeding, hospitalization time, perioperative mortality, and 1-, 3-and 5-year overall survival rates between two groups. Conclusions: This meta-analysis suggested that adopting SFSG in adult LDLT has comparable outcomes to those with non-SFSG counterparts since 2010.

基于Cow-DETR与深度图像的非接触式奶牛体质量评估

针对当前牧场奶牛体质量(体重)称量效率低,人工参与容易引发奶牛应激等问题,提出了一种基于改进DETR(Detection transformer)网络的端到端式奶牛体质量评估方法(Cow-DETR),实现利用奶牛背部深度图像进行非接触式奶牛体质量评估。首先设计并搭建实验数据采集装置,利用Intel RealSense D435深度相机和体重秤采集奶牛背部深度图像和体质量数据;然后,通过边缘平滑滤波器和孔洞填充滤波器对深度图像进行补全处理,减少深度数据缺失对体质量评估的影响;最后,以DETR网络为基础建立奶牛体质量评估模型,通过在预测模块中添加含有交替全连接层的体质量预测单元,提升奶牛体质量相关的特征信息提取能力,实现端到端式奶牛背部定位的同时进行奶牛体质量非接触式评估。结果表明,本文方法可以实现较高精度的奶牛体质量评估,通过5倍交叉验证,在含有139头奶牛数据的数据集中,平均绝对误差不超过17.21 kg,平均相对误差不超过3.71%,单幅图像平均识别时间为0.026 s。通过与现有体质量评估方法相对比,本文方法比其他6种方法在更多的奶牛头数的数据集中取得了更低的平均绝对误差和平均相对误差,同时本文方法对奶牛站立姿势要求较低,更符合牧场实际生产需要,为奶牛体质量评估提供了新的解决思路。

THE RELATION OF SEQUENCE DISTRIBUTIONS OF S-SBR TO ITS MOLECULAR WEIGHT DISTRIBUTIONS

The relationship between sequence distributions and molecular weight distributions of S-SBR, obtained from styrene and butadiene anionic copolymerization at various conversions with THF/Li^+ as an initiator has been studied by ^(13)C-NMR,GPC. The results showed that the molecular weight distributions of the copolymer couldbe correlated sophisticatedly to the binary sequcne distributions or the monomer unit distributions of the copolymer in a corrected Poisson's distribution from.

Splenectomy in living donor liver transplantation and risk factors of portal vein thrombosis

Background:Graft inflow modulation(GIM)during adult-to-adult living donor liver transplantation(LDLT)is a common strategy to avoid small-for-size syndrome,and some transplant surgeons attempt small size graft strategy with frequent GIM procedures,which are mostly performed by splenectomy,in LDLT.However,splenectomy can cause serious complications such as portal vein thrombosis and overwhelming postsplenectomy infection.Methods:Forty-eight adult-to-adult LDLT recipients were enrolled in this study and retrospectively reviewed.We applied the graft selection criteria,which routinely fulfill graft-to-recipient weight ratio≥0.8%,and consider GIM as a backup strategy for high portal venous pressure(PVP).Results:In our current strategy of LDLT,splenectomy was performed mostly due to hepatitis C and splenic arterial aneurysms,but splenectomy for GIM was intended to only one patient(2.1%).The final PVP values≤20 mmHg were achieved in all recipients,and no significant difference was observed in patient survival or postoperative clinical course based on whether splenectomy was performed or not.However,6 of 18 patients with splenectomy(33.3%)developed postsplenectomy portal vein thrombosis(PVT),while none of the 30 patients without splenectomy developed PVT after LDLT.Splenectomy was identified as a risk factor of PVT in this study(P<0.001).Our study revealed that a lower final PVP could be risk factor of postsplenectomy PVT.Conclusions:Using sufficient size grafts was one of the direct solutions to control PVP,and allowed GIM to be reserved as a backup procedure.Splenectomy should be avoided as much as possible during LDLT because splenectomy was found to be a definite risk factor of PVT.In splenectomy cases with a lower final PVP,a close follow-up is required for early detection and treatment of PVT.

SGM模型牦牛子模型生长发育模块校验及应用

基于前期构建的Sustainable Grassland Model(SGM)模型框架,选用并改进GRAZPLAN动物模型和不完全小区模拟方法,在MATLAB平台对SGM模型进行二次开发,建立牦牛子模型生长发育模块,以期为青藏高原可持续放牧生产体系的构建提供研究工具及决策支持。采用局部敏感度分析法,筛选并计算敏感度系数确定牦牛子模型生长发育模块下放牧采食量和体重变化模拟中的敏感参数,以已发表的研究数据为基础,利用最小二乘法建立敏感参数校准模型并完成模块校准,校准后运行模型,得到的增重模拟结果与前人发表的研究数据比对后进行统计分析,完成模型检验。检验后的模型以甘肃省玛曲县高寒草甸典型牦牛牧户(草地中度退化)为研究对象进行模型示范。结果表明:经参数校验后的SGM牦牛子模型在模拟牦牛放牧采食量和增重方面切实可行。示范结果证明SGM模型能够合理地模拟粗放型生产管理下放牧压力的降低对高寒草甸牦牛放牧生产体系草地地上生物量、植物群落功能组成、家畜放牧采食量和体重变化的长期影响,说明SGM模型在青藏高原高寒草甸模拟放牧压力对放牧生产体系的长期影响具有可行性。该模型采用不同的参数,基于同一套数学公式实现对放牧牛羊生长发育的模拟,在未来牛羊放牧系统模型开发中具有良好的应用前景,但需要针对模拟对象的实际实施校准,且对牦牛产奶量和放牧采食量的模拟仍需进一步开发和改进。

法系长白母仔猪出生体重、胎次及配种日龄对其终身生产力影响

以128头法系长白母猪560窝次的生产繁殖成绩为研究对象,分析母仔猪的出生体重、出生胎次、出生同窝活仔数、配种日龄对其终身生产力的影响。结果表明,长白母仔猪的出生体重、出生胎次、出生同窝活仔数和配种日龄对终身断奶仔猪数、终身断奶窝重影响均不显著(P>0.05)。其中,Ⅱ组母仔猪的出生体重在1.3~1.5 kg之间,其终身断奶仔猪数最高为50.45头,分别比Ⅰ、Ⅲ组母仔猪提高6.79头、4.52头,Ⅲ组母猪终身断奶仔猪数为45.93头,比Ⅰ组提高2.27头,差异不显著(P>0.05)。终身断奶窝重也以Ⅱ组最高,为315.06 kg,分别比Ⅰ组、Ⅲ组提高16.74%、9.07%,Ⅲ组终身断奶窝重为288.85 kg,比Ⅰ组提高7.03%,差异不显著(P>0.05)。长白母仔猪的出生体重、出生胎次、出生同窝活仔数、配种日龄与终身生产力的相关性分析表明,偏相关系数有正有负,相关强度有大有小。其中,长白母仔猪的出生体重与出生胎次极显著正相关,偏相关系数为0.269(P<0.01);与出生同窝活仔数极显著负相关,偏相关系数为-0.424(P<0.01);母猪产仔胎数与终身断奶仔猪数极显著正相关,偏相关系数为0.235(P<0.01),终身断奶仔猪数与终身断奶窝重极显著正相关,偏相关系数为0.965(P<0.01),其他指标间相关性不显著。

广西麻鸡活重、体尺与产蛋量的关系分析

为探究广西麻鸡活重及体尺性状与个体产蛋量的相关性,以某公司提供的广西麻鸡为观测对象,连续30 d产蛋数据为依据,进行了初步研究和分析。结果显示,个体最高产蛋数24个,最低0个,产蛋数集中分布在10~19个,产蛋数在该区间的个体共71羽,占鸡群的46.71%。广西麻鸡产蛋期活重与产蛋量呈极显著负相关(P<0.01),两者相关系数达到中度相关(r=-0.647)。其他体尺性状包括体斜长、龙骨长、胫长与产蛋量的差异不显著(P>0.05)。综上所述,可以根据活重对广西麻鸡的选育做出指导,研究可为广西麻鸡育种工作提供数据参考。

多羔绵羊屠宰性状及其与活重的关系

[目的]肉羊的宰前活重和屠宰性状直接影响其经济价值,本研究分析多羔绵羊新品种群的屠宰性状及其与宰前活重的关系,对新品种选育和生产推广具有参考作用。[方法]测定6、12月龄(各月龄20只羊,公母各半)多羔绵羊的宰前活重(live body weight,LBW)、胴体重(carcass weight,CW)、净肉重(meat weight,MW)和眼肌面积(eye muscle area,EMA)。对3项屠宰性状与宰前活重进行线性回归分析,分别建立活重与3项屠宰性状间的回归关系。[结果]公母羊屠宰率均在50%以上,除屠宰率外,多羔绵羊12月龄的屠宰性状均高于6月龄。6月龄多羔绵羊宰前活重和屠宰率相比国内其他优良绵羊品种均属较高水平。在各月龄间,活重与胴体重、净肉重和眼肌面积间存在极显著的回归关系。[结论]多羔绵羊生长发育快、产肉性能高,可用宰前活重估算各月龄的相关屠宰性状值。

有剖宫产史高龄女性不同胚胎移植方案和妊娠结局回顾性分析

目的:分析高龄有剖宫产史女性接受辅助生殖技术助孕不同移植方案的助孕结局。方法:回顾性分析进行体外受精-胚胎移植(IVF-ET)治疗的2098例既往有孕28周以上分娩史,且年龄≥35岁的高龄女性及其伴侣的临床资料,根据既往分娩方式分为剖宫产史组(909例)及阴道产史组(1180例),比较两组患者IVF-ET治疗中新鲜周期不同移植策略时的活产结局。结果:虽然剖宫产史组患者较阴道产史组年轻(38.16岁与38.69岁),根据移植个数及第3/5天胚胎进行亚组分析后发现,移植1枚第3天胚胎时两组活产率比较没有统计学差异,而移植1枚囊胚时临床妊娠率相当,但剖宫产组早期流产率升高,因此活产率低于阴道产史组,有统计学差异(P=0.236、0.01);移植2枚第3天胚胎剖宫产史组活产率显著低于阴道产史组(P=0.023);而移植2枚第5天囊胚时,剖宫产史组活产率与阴道产史组比较无统计学差异(P=0.847),但剖宫产史组平均分娩孕周未达足月,低出生体重儿占比较阴道产史组高,有统计学差异(P=0.015)。结论:剖宫产史影响高龄女性IVF/ICSI助孕的活产率,移植策略建议首选单囊胚移植;而移植2枚囊胚时,剖宫产史会增加新生儿低出生体重风险,则需谨慎对待。

甘肃省乡村人居环境质量评价

从“三生”空间的视角出发,以生产环境、生活环境、生态环境为3个维度构建乡村人居环境质量指标体系,通过熵权TOPSIS模型对甘肃省2008—2020年乡村人居环境质量进行评价。研究发现:甘肃省乡村人居环境质量发展相对缓慢,综合指数整体偏低,省内市州发展水平各不相同,嘉峪关、酒泉处于领先地位,张掖、金昌、武威次之,兰州、白银、天水、庆阳、定西、陇南发展一般,平凉、临夏自治州、甘南自治州名列其他市州之后。其中,生态及生活指标对甘肃省乡村人居环境质量影响较大。因此,针对划分为不同等级区的市州提出了“因地制宜,分类施策”的差异化治理策略。