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81.
Growth and ultimate size can provide important population insights and a sound biological basis for setting length limits, which can be the best single regulation for preventing overexploitation of muskellunge (Esox masquinongy) populations. A system was developed, using cleithral age and total length at age confidence limits (CL) data, to determine reproductive and growth potential (ultimate size) for calculating and setting increased size limits based on minimum reproductive size (upper 99% CL at age at first maturity + 2 year) and minimum ultimate size (MUS) calculated from the lower 99% CL—minimum ultimate size limit (MUSL). MUS also provides a trophy standard and an index of relative size for comparing trophy potential of individuals within and among populations. Guidelines are provided for determining minimum sample size (mean ± 95% confidence interval = 12 ± 4) and minimum age (8–10 ± 2.0 year) required to produce valid von Bertalanffy growth trajectories. MUS, MUSL, and trophy standards for both length and estimated weight are provided for female and male muskellunge from 14 Ontario sources. Mean MUS, or trophy standard, for females was 115 ± 10.3 cm (MUSL range 75–135) and 11.1 ± 2.6 kg (2.5–17.5) and for males was 95 ± 7.5 cm (66–110) and 6.1 ± 1.3 kg (1.9–9.2). These indices can precisely define growth and growth potential for muskellunge populations and individuals and can be used to better manage and maintain or improve the quality of muskellunge populations and fisheries. Dedicated to the late Dr. E.J. Crossman.  相似文献   
82.
Goal, Scope and Background The life cycles of many products including textiles contain chemicals for which process flow data are not known or are too time consuming to collect. Although each chemical may not contribute significantly to the LCA results of the product, which might justify excluding them, but together their contribution could be significant. Similarly, rough estimates of the process flows for the production of a single chemical may be very uncertain and considered meaningless, while the estimates of the cumulative data of process flows for several chemicals may be less uncertain and be a meaningful contribution to the quality of the LCA results. There are methods for estimation of process flows for different types of products, with varying demands regarding input data and time and with varying accuracy of the results. This work contributes to the available methods, focusing on simple estimations for production of chemical substances. The goal was to create a fast method for estimation of emissions, resource and energy flows (process flows) for the production of chemicals, based on easily available data on the properties of the chemicals. The process flows investigated were limited to those normally associated with process industries and contributing most to depletion of resources, to global warming, acidification, eutrophication and photochemical ozone production, i.e. use of energy, crude oil, coal, natural gas, uranium in ore and emissions of CO2, SOx, NOx, NMVOC, methane, BOD, COD and total N. Toxic substances were excluded, since toxic emissions are substance specific and cannot be included in a generalization. Method Available data for the process flows for the production of chemicals of mainly fossil origin were correlated to properties of chemicals such as amount of carbon in the molecule, heat of formation and average number of chemical reaction steps in the production. The production procedures were found in readily available literature. Up to about six reaction steps were evaluated in the correlation study. The variations in the process flows among the chemicals studied were calculated. Results and Discussion There were weak correlations between average number of chemical reaction steps in the production and energy use, COD measured in water emissions, and SOx and NOx emissions to air. For the remaining properties of chemicals and process flows, there were only weak correlations for share of double bonding in the molecule if only molecules containing double bondings were included. Conclusions The precision in estimation of the process flows increases non-significantly when adding information on the number of reaction steps or share of double bonding for chemicals containing double bonding is added. Recommendations and Outlook It seems reasonable to start with a simple grouping method to estimate the process flows for the production of a chemical of fossil origin. Further investigations might investigate whether there is a correlation between process flows and the costs of chemicals, and further study the correlations between process flows and share of double bonding for chemicals containing double bondings.  相似文献   
83.
疾病资源库在转化医学发展中发挥着重要作用,收集人类遗传资源和疾病相关资源信息,建设疾病资源库越来越受到重视。首都医科大学附属北京佑安医院在建设乙型肝炎和艾滋病疾病资源库的过程中,总结疾病资源库建设经验,为中国疾病资源库建设的标准化提供参考。  相似文献   
84.
妇幼机构四大保健部设置,是国家卫生计生委在新妇幼机构规范化建设标准中提出,其目的是解决妇幼保健管理、认识和定位的误区,各妇幼保健机构在落实四大部设置中存在的困难。文章以秦皇岛市妇幼保健院部制改革为例,寻求探索解决地市妇幼保健机构实施四大保健部设置的方法。  相似文献   
85.
Ecological studies require key decisions regarding the appropriate size and number of sampling units. No methods currently exist to measure precision for multivariate assemblage data when dissimilarity‐based analyses are intended to follow. Here, we propose a pseudo multivariate dissimilarity‐based standard error (MultSE) as a useful quantity for assessing sample‐size adequacy in studies of ecological communities. Based on sums of squared dissimilarities, MultSE measures variability in the position of the centroid in the space of a chosen dissimilarity measure under repeated sampling for a given sample size. We describe a novel double resampling method to quantify uncertainty in MultSE values with increasing sample size. For more complex designs, values of MultSE can be calculated from the pseudo residual mean square of a permanova model, with the double resampling done within appropriate cells in the design. R code functions for implementing these techniques, along with ecological examples, are provided.  相似文献   
86.
p27Kip1 is a cyclin-dependent kinase inhibitor that plays a critical role in regulating G1/S transition, and whose activity is, in part, regulated through interactions with D-type cyclins. We have generated the BD1-9 cell line, a BaF3 pro-B cells derivative in which cyclin D1 can be induced rapidly and reversibly by ponasterone A. The induction of cyclin D1 expression leads to a targeted p27Kip1 accumulation in both cytoplasmic and nuclear compartments. But, only the p27Kip1 form phosphorylated on serine 10 (pSer10-p27Kip1) accumulates in BD1-9 cells. We found that the binding of cyclin D1 and pSer10-p27Kip1 prevents p27Kip1 degradation by the cytoplasmic Kip1 ubiquitylation-promoting complex (KPC) proteosomic pathway. Importantly, the nuclear CDK2 activity which is crucial for G1/S transition is not altered by p27Kip1 increase. Using siRNA techniques, we revealed that p27Kip1 inhibition does not affect the distribution of BD1-9 cells in the different phases of the cell cycle. Our study demonstrates that aberrant cyclin D1 expression acts as a p27Kip1 trap in B lymphocytes but does not induce p27Kip1 relocation from the nucleus to the cytoplasm and does not modulate the G1/S transition. Since our cellular model mimics what observed in aggressive lymphomas, our data bring new insights into the understanding of their physiopathology.  相似文献   
87.
BTEX的环境质量标准研究进展   总被引:1,自引:0,他引:1  
苯系物(BTEX)是苯(benzene)、甲苯(toluene)、乙苯(ethylbenzen)和二甲苯的3种同分异构体(o-,m-,p-xylene)的统称。由于其广泛存在于大气、水和土壤等环境介质中,并对相应的生态系统和人类健康造成威胁,引起了有关部门的高度重视。本文综述了BTEX的环境质量标准研究,通过介绍美国环保局、澳大利亚和加拿大等发达国家以及世界卫生组织、欧盟等国际组织关于BTEX的室内空气、地表水和土壤环境质量标准,并与我国对应标准进行比较,指出我国环境质量标准中存在的一些问题和不足。最后,对今后我国BTEX环境基准的系统研究提出建议。  相似文献   
88.
实时荧光定量PCR技术在转基因食品检测领域中的应用   总被引:1,自引:0,他引:1  
随着基因工程技术在农业生产中应用的深入,越来越多具有改良特征的转基因植物在全球范围内得到广泛种植,随之而来的转基因食品也迅猛发展,转基因产品大规模商业化引起了对安全性问题的担忧。为保证转基因产品标签制度的顺利实施,建立快速、准确、高通量的定量检测方法十分必要。我们综述了国内外转基因食品检测技术的研究进展,重点阐述了实时荧光定量PCR技术在转基因食品检测领域中的应用,并展望了通过构建质粒标准分子的方法来实现对更多转基因植物品系的定量检测。  相似文献   
89.
We investigated the interaction of 2,4,6-triiodophenol (TIP), a potent thyroid hormone disrupting chemical, with serum proteins from rainbow trout (Onchorhynchus mykiss), bullfrog (Rana catesbeiana), chicken (Gallus gallus), pig (Sus scrofa domesticus), and rat (Rattus norvegicus) using a [(125)I]TIP binding assay, gel filtration chromatography, and native polyacrylamide gel electrophoresis. [(125)I]TIP bound non-specifically to proteins in trout serum, specifically but weakly to proteins in bullfrog serum, and specifically and strongly to proteins in chicken, pig, and rat serum samples. Candidate TIP-binding proteins included lipoproteins (220-320kDa) in trout, albumin in bullfrog, albumin and transthyretin (TTR) in chicken and pig, and TTR in rat. TTR in the chicken, pig, and rat serum samples was responsible for the high-affinity, low-capacity binding sites for TIP (dissociation constant 2.2-3.5×10(-10)M). In contrast, a weak interaction of [(125)I]TIP with tadpole serum proteins accelerated [(125)I]TIP cellular uptake in vitro. Intraperitoneal injection of [(125)I]TIP in tadpoles revealed that the radioactivity was predominantly accumulated in the gallbladder and the kidney. The differences in the molecular and binding properties of TIP binding proteins among vertebrates would affect in part the cellular availability, tissue distribution and clearance of TIP.  相似文献   
90.
Few studies have been made in regard to the effect of aluminum on the molecular and cellular structure and function of aquatic organisms; therefore, in the present report we determined the genotoxic and cytotoxic effects induced by the metal on the lymphocytes of carp (Cyprinus carpio). Three groups of fish were exposed to 0.05, 120, and 239 mg/L of aluminum (Al), respectively, by using Al2 (SO4)3·7H2O, and another group was included as control. The cells obtained were studied with the comet assay, flow cytometry, and the TUNEL method. With the first method we found a concentration and time dependent, significant increase in the amount of DNA damage induced by Al, and a higher damage when we evaluated the level of oxidized DNA. By applying flow cytometry we established that the metal induced a DNA content increase and ploidy modifications as well as apoptosis and disturbances of the cell cycle progression. With the last method we determined a significant increase in the amount of apoptotic cells, mainly in the 72–96 h period. Our results established that Al caused deleterious DNA and cellular effects in the tested organism, and they suggested the pertinence of evaluating toxicity induced by the metal in organisms living in contaminated water bodies.  相似文献   
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