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921.
Sea turtles interact with a variety of fishing gears across their broad geographic distributions and ontogenetic habitat shifts. Cumulative assessments of multi-gear bycatch impacts on sea turtle populations are critical for coherent fisheries bycatch management, but such estimates are difficult to achieve, due to low fisheries observer effort, and a single-species, single-fishery management focus. We compiled the first cumulative estimates of sea turtle bycatch across fisheries of the United States between 1990 and 2007, before and after implementation of fisheries-specific bycatch mitigation measures. An annual mean of 346,500 turtle interactions was estimated to result in 71,000 annual deaths prior to establishment of bycatch mitigation measures in US fisheries. Current bycatch estimates (since implementation of mitigation measures) are ∼60% lower (137,800 interactions) and mortality estimates are ∼94% lower (4600 deaths) than pre-regulation estimates. The Southeast/Gulf of Mexico Shrimp Trawl fishery accounts for the overwhelming majority of sea turtle bycatch (up to 98%) in US fisheries, but estimates of bycatch in this fishery are fraught with high uncertainty due to lack of observer coverage. Our estimates represent minimum annual interactions and mortality because our methods were conservative and we could not analyze unobserved fisheries potentially interacting with sea turtles. Although considerable progress has been made in reducing sea turtle bycatch in US fisheries, management still needs improvement. We suggest that sea turtle bycatch limits be set across US fisheries, using an approach similar to the Potential Biological Removal algorithm mandated by the Marine Mammal Protection Act.  相似文献   
922.
Yeast bread is a major contributor of sodium in the American diet. Because of its functional impact on dough rheology and the quality of the final baked product, simply reducing the level of sodium chloride (salt) in the formula or replacing it with salt substitutes has found minimal success. The objective of this study was to determine the effect of sea salt containing 57 or 64% less sodium than common sea salt on the breadmaking properties and consumer acceptability of bread. The sodium content of the salt had no effect on dough strength, mixing time, gas production, loaf volume, or crumb grain. The flavor and overall liking of breads containing sea salt with 57 and 64% less sodium content were scored only slightly lower than bread containing the control salt by an untrained panel of 118 consumers. No difference in texture and no unacceptable flavor notes in the bread made with reduced‐sodium salts were reported. Thus, it appears that use of reduced‐sodium sea salt is a satisfactory alternative to reduce the sodium content of bread.  相似文献   
923.
Controlled chemical modifications of single-walled carbon nanotubes (SWCNTs) that tune their useful properties have been sought for multiple applications. We found that beneficial optical changes in SWCNTs resulted from introducing low concentrations of oxygen atoms. Stable covalently oxygen-doped nanotubes were prepared by exposure to ozone and then light. Treated samples showed distinct, structure-specific near-infrared fluorescence at wavelengths 10 to 15% longer than displayed by pristine semiconducting SWCNTs. Dopant sites harvest light energy absorbed in undoped nanotube regions by trapping mobile excitons. The oxygen-doped SWCNTs are much easier to detect and image than pristine SWCNTs because they give stronger near-infrared emission and do not absorb at the shifted emission wavelength.  相似文献   
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The objective of this retrospective case series, which included 82 client-owned soft-coated wheaten terriers, was to characterize clinical features of hypoadrenocorticism in this breed. Median age at diagnosis was 3.5 years. There was no gender predilection. Clinicopathologic findings included sodium/potassium ratio < 27 (85%), hyperkalemia (76%), hyponatremia (63%), elevated blood urea nitrogen (83%) or creatinine (71%), and hypercalcemia (36%). Nine dogs with normal sodium and potassium (11%) were older and less often azotemic, hyperphosphatemic, or hypercalcemic. Twenty-one dogs (26%) developed protein-losing nephropathy (n = 18) and/or end-stage renal disease (n = 3). Overall median survival time was 5.4 years, but was shorter in dogs with normal sodium and potassium at diagnosis (4.2 years), or those with subsequent protein-losing nephropathy (4.2 years). This population showed no gender predilection, unlike that reported in the general canine population with hypoadrenocorticism, and more comorbid protein-losing nephropathy than in the general soft-coated wheaten terrier population.  相似文献   
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Transposable elements (TEs) are abundant in the human genome, and some are capable of generating new insertions through RNA intermediates. In cancer, the disruption of cellular mechanisms that normally suppress TE activity may facilitate mutagenic retrotranspositions. We performed single-nucleotide resolution analysis of TE insertions in 43 high-coverage whole-genome sequencing data sets from five cancer types. We identified 194 high-confidence somatic TE insertions, as well as thousands of polymorphic TE insertions in matched normal genomes. Somatic insertions were present in epithelial tumors but not in blood or brain cancers. Somatic L1 insertions tend to occur in genes that are commonly mutated in cancer, disrupt the expression of the target genes, and are biased toward regions of cancer-specific DNA hypomethylation, highlighting their potential impact in tumorigenesis.  相似文献   
930.
国外栽培豌豆遗传多样性分析及核心种质构建   总被引:9,自引:0,他引:9  
从111对备选SSR引物中筛选出能扩增出清晰稳定单一带的多态性引物21对及其最佳退火温度, 并优化了豌豆SSR标记实验体系。利用上述引物, 对来自于67个国家的731份豌豆栽培种质(Pisum sativum L.)进行遗传多样性分析与核心种质构建。共扩增出109条多态性带, 每对引物平均扩增出5.19个等位变异。SSR等位变异在各大洲间分布不均匀, 有效等位变异数、Shannon’s信息指数(I)洲际间差异明显。各大洲资源群间遗传多样性差异显著, 其中亚洲最高(I = 1.1753), 欧洲其次(I = 1.1387), 俄罗斯联邦(I = 1.0285)、美洲(I = 1.0196)、非洲(I = 0.9254)、大洋洲(I = 0.8608)依次降低。利用Popgene 1.32软件, 依豌豆栽培资源洲际间Nei78遗传距离可聚类成2个组群和4个亚组群; 基于Structure 2.2软件分析, 国外栽培豌豆资源实际由3大类群组成, 并与Popgene 1.32聚类结果呼应得较好。上述两种分析方法均表明, 国外栽培豌豆类群的遗传多样性与其地理分布相关。设计并实践了一套基于Structure分析的科学可靠、逻辑性强的核心种质构建标准化方案, 并依此构建了一套以6.57%的资源(48份)涵盖总体84.4%等位变异的国外栽培豌豆核心种质。  相似文献   
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