Echocardiographic Estimates of Right Ventricular Systolic Function in Dogs with Myxomatous Mitral Valve Disease

Background

Right ventricular (RV) dysfunction independently predicts outcomes in human myxomatous mitral valve disease (MMVD). There is limited information regarding RV systolic function in dogs with MMVD.

Hypothesis

Right ventricular systolic function differs among stages of disease, decreasing in decompensated MMVD.

Animals

Thirty‐sixclient‐owned dogs with MMVD not receiving oral cardiovascular medications.

Methods

Prospective clinical study. Dogs were categorized according to disease severity as ACVIM Stage B1, B2, or C. Seven echocardiographic indices of RV systolic function were measured. Groups were compared by 1‐way ANOVA and Tukey's HSD test. Frequencies of cases with cardiac remodeling falling outside previously established reference intervals were compared using Fisher's exact test. Intra‐ and interobserver measurement variability was calculated for each RV function index.

Results

The indices TAPSE (P = 0.029), RV St_L (P = 0.012), and RV StR_L (P = 0.041) were significantly different between groups. A greater proportion of B2 dogs (7 of 12) had TAPSE values above reference intervals compared with B1 (2 of 12) or C (2 of 12) dogs (P = 0.027). Measurement variability of TAPSE, RV S', and RV St_G was clinically acceptable.

Conclusions and Clinical Importance

Right ventricular systolic function differs between stages of MMVD, increasing in stage B2, and declining in stage C. The prognostic importance of RV function indices, particularly TAPSE, might be worth evaluating in dogs with MMVD.     

Ranking cows’ methane emissions under commercial conditions with sniffers versus respiration chambers

This study assessed the ranking of dairy cows using individual-level correlations for methane (CH₄) emission on-farm using sniffers and in respiration chambers. In total 20 lactating dairy cows, ten Holstein and ten Jerseys were recorded using sniffers installed in milking robots for three weeks of lactation and subsequently in respiration chambers (RC) where they were each recorded on three occasions within the RC. Bivariate linear mixed models were used to determine the individual-level correlations (r_I) between sniffer and RC phenotypes as proxies for genetic correlations. Despite differences in feeding and management, the predicted CH₄ production from sniffers correlated highly with RC CH₄ production r_I?=?0.77?±?0.18 and CH₄ breath concentration correlated nearly as well with RC CH₄ production r_I?=?0.75?±?0.20. These correlations between sniffers on-farm and RC demonstrate the potential of sniffers measurements as large-scale indicator traits for CH₄ emissions in dairy cattle.     

四个紫花苜蓿品种种子萌发期耐盐性研究

在实验室内模拟的盐分条件下,用不同浓度的Na Cl盐溶液对4个紫花苜蓿品种(中苜1号、中苜3号、中草3号和陇东苜蓿)种子萌发期进行盐胁迫处理。结果表明:低浓度(0.2%和0.4%)的盐溶液对苜蓿的发芽率和幼苗苗高抑制作用不显著,对幼根具有一定的刺激作用。0.8%和1.0%的Na Cl溶液处理下发芽率、0.6%的Na Cl溶液处理下的幼苗苗高和幼根生长量可以作为苜蓿种子萌发期耐盐性鉴定指标。对四个紫花苜蓿品种的发芽率、幼苗苗高、幼根生长量、耐盐半致死浓度四个指标进行综合分析,结果表明:中苜1号耐盐性最强,其次是中苜3号和中草3号,陇东苜蓿最弱。     

Evaluation of β‐carotene assimilation in leopard geckos (Eublepharis macularius)

Although leopard geckos (Eublepharis macularius) are commonly kept under human care, their vitamin requirements are largely unknown. Many invertebrate preys display a low vitamin A concentration; thus, gut‐loading insects with vitamin A or carotenoids is a common practice. The objective of this prospective experimental study was to investigate whether dietary supplementation with β‐carotene, including prey gut‐loading, leads to sufficient vitamin A hepatic storage and prevents epithelial squamous metaplasia development in leopard geckos. Ten clinically healthy female leopard geckos were randomly divided in two groups with various supplementations: a group receiving vitamin A supplementation and a group receiving β‐carotene. Insects were gut‐loaded continuously with a supplement containing vitamin A or β‐carotene, depending on the group. Oral supplementation with cod liver oil or carrot juice was administered weekly to each lizard from “vitamin A group” and “carotenoid group” respectively. After 10 weeks of supplementation, surgical hepatic biopsies were obtained in three geckos of each group while the two remaining geckos were euthanized to undergo complete necropsy. Hepatic vitamin A concentration was determined for each lizard (n = 10) by ultra‐performance liquid chromatography. Histopathology revealed hepatocellular vacuolization and vitellogenic follicles in five females. Epithelial squamous metaplasia was not observed in any of the geckos. Hepatic vitamin A concentration was significantly higher in the carotenoid‐supplemented group than in the vitamin A‐supplemented group (p = 0.03). Our results suggest that in leopard geckos, dietary supplementation with β‐carotene allows sufficient vitamin A hepatic storage.     

Ecological consequences of variation in standard metabolism and dominance among salmon parr

Abstract – Standard metabolic rate (SMR, closely related to basal and resting metabolism) varies by up to threefold among juvenile Atlantic salmon, Salmo salar L., of similar size at common temperature. Here, consequences of this variation are predicted by combining empirically derived relationships between SMR, specific dynamic action, energy budgets, water velocity, food level in the environment and food availability to fish. The range of velocities across which growth is predicted to occur is inversely related to a fish’s SMR. Growth is positively related to SMR at high but negatively related to it at low‐food levels. The relationship between food level and the range of velocities over which lower SMR fish can grow but higher SMR fish cannot is asymmetrically bi‐phasic and peaked. It is predicted that maternal manipulation of offspring SMR would generate fitness benefits through bet‐hedging against unpredictability in food level and increases in the overall range of velocities that the family of offspring can occupy and thrive in.     

7株根瘤菌菌株与热研2号柱花草共生最适磷浓度研究

采用水培的方法,设3个磷水平,7个菌株,通过对株高、茎叶鲜重、茎叶干重、固氮酶活性、茎叶氮含量、茎叶磷含量的测定及综合分析,确定使热研2号柱花草接种不同根瘤菌菌株达到最佳促生性能的磷浓度。结果表明:7个菌株在中磷时鲜重和含氮量最大,低磷不利于鲜重和含氮量的增加;经主因子综合分析,菌株YM11-1、RJS9-2、PN13-3在高磷时对热研2号柱花草有最好的固氮促生效果,菌株LZ3-2、BS1-1、PN13-3在中等磷条件下有最好的固氮促生效果,菌株FS3-1-1在高磷和中磷都有最好的固氮促生效果。     

粉条加工中添加石蜡的检测技术研究

【目的】探讨粉条加工过程中非法添加石蜡的测定方法,为食品监管提供保障。【方法】先以石蜡成品摸索石蜡测定的气相色谱质谱条件,再以石蜡成分C18H38和C24H50进行回收率和相对标准偏差试验。【结果】不同预处理方法中,超声萃取处理的C18H38和C24H50在粉条中的萃取回收率最高,分别为93.5%和91.0%;20min超声时间萃取粉条中烷烃成分较为适宜;所建立的粉条中石蜡含量测定方法的相对标准偏差为3.6～4.8,样品回收率均大于90.0%,达到定量检测要求。【结论】所建立的石蜡检测方法操作简单,测定结果准确可靠,可用于粉条中石蜡成分的定性及定量测定。     

速生林木材液化及其产物应用研究

[目的]为速生桉树木材液化及其产物的应用提供参考。[方法]以硫酸为催化剂,苯酚为液化剂,对速生人工林桉树木材进行液化,并取液化产物与甲醛进行树脂化反应制备液化木基酚醛树脂LWPF,研究液比对液化反应效率、液化产物重均分子量及LWPF树脂胶合性能的影响。[结果]随着液比的提高,液化产物的残渣率及重均分子量均降低,而LWPF树脂制得的胶合板的木破率提高;当液比提高到一定程度后,液化产物的残渣率和重均分子量及LWPF树脂所制胶合板的木破率变化不明显。[结论]对速生桉树木材的液化工艺及其液化产物的树脂化合成工艺进行了优化。     

提取剂对大蒜鳞茎提取液抑制黄瓜枯萎病的效应

为反映提取剂类型对大蒜鳞茎提取液抑菌能力的影响,用水、乙醇,丙三醇作为大蒜鳞茎杀菌物质的提取剂,采用孢子萌发法对黄瓜镰刀菌枯萎病菌孢子抑杀.研究结果表明,3种提取溶剂制成的大蒜鳞茎提取液对枯萎病菌孢子抑制的EC50值分别为0.2884%、0.2818%和0.2454%,较低的提取液浓度达到了较好的抑菌效果.水、乙醇、丙三醇都可以作为大蒜鳞茎的提取剂,3种提取溶剂的大蒜鳞茎提取液毒力相当,孢子抑制萌发率随着大蒜鳞茎提取液浓度增加而升高.