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11.
Two methods were used to radioiodinate sea urchin sperm: lactoperoxidase-glucose oxidase and Iodo-Gen. Following iodination the sperm are viable, they undergo the acrosome reaction, and they fertilize eggs. Of the radioactivity associated with the labeled sperm, 28–50% is presumed to be free 125I?, 37–47% is incorporated in lipid, and 8–15% is in trypsin-digestible material believed to be protein. Digestion of the labeled, living sperm with trypsin removes 95.6–99.5% of the macromolecular label (the cells are alive after digestion) suggesting that almost all the protein label is on the external surface of the cell. Thin-layer chromatography of the lipid fraction shows that the major membrane phospholipids and cholesterol are labeled. SDS-PAGE analysis shows the protein-incorporated 125I is distributed among four glycoproteins of >250K, 84K, 64K, and 52K dalton apparent molecular weight. Twenty-eight percent of the total protein (trypsin-digestible) label is in the 84K component and 46% in the 64K band. Although both molecules contain much of the label, they are relatively minor components of the TX-100 extract of sperm. The methods outlined will be useful in determining the role of sperm surface components in fertilization. 相似文献
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In this paper we propose an instrument for collecting sensitive data that allows for each participant to customize the amount of information that she is comfortable revealing. Current methods adopt a uniform approach where all subjects are afforded the same privacy guarantees; however, privacy is a highly subjective property with intermediate points between total disclosure and non-disclosure: each respondent has a different criterion regarding the sensitivity of a particular topic. The method we propose empowers respondents in this respect while still allowing for the discovery of interesting findings through the application of well-known inferential procedures. 相似文献
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Carlos Rico José Luis Rico Noelia Muñoz Beatriz Gómez Iñaki Tejero 《Engineering in Life Science》2011,11(5):476-481
The effect of mixing on biogas production of a 1.5‐m3 pilot continuous stirred tank reactor (CSTR) processing screened dairy manure was evaluated. Mixing was carried out by recirculation of reactor content with a mono pump. The experiment was conducted at a controlled temperature of 37±1°C and hydraulic retention times (HRTs) of 20 and 10 days. The effect of continuous and intermittent operation of the recirculation pump on biogas production was studied. At 10 days of HRT, the results showed a minimal influence of recirculation rate on biogas production and that continuous recirculation did not improve reactor performance. At 20 days of HRT, the recirculation rate did not affect reactor performance. Combination of low solid content in feed animal slurry and long HRTs results in minimal mixing requirements for anaerobic digestion. 相似文献
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Household‐level correlates of children's physical activity levels in and across 12 countries
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Deirdre M. Harrington Fiona Gillison Stephanie T. Broyles Jean‐Philippe Chaput Mikael Fogelholm Gang Hu Rebecca Kuriyan Anura Kurpad Allana G. LeBlanc Carol Maher Jose Maia Victor Matsudo Timothy Olds Vincent Onywera Olga L. Sarmiento Martyn Standage Mark S. Tremblay Catrine Tudor‐Locke Pei Zhao Peter T. Katzmarzyk for the ISCOLE Research Group 《Obesity (Silver Spring, Md.)》2016,24(10):2150-2157
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L.E. Palma-Cano H.A. Piñon-Castillo S.H. Tarango-Rivero A. Carbon J. Salas-Leiva L.N. Muñoz-Castellanos C. Cravo-Laureau R. Duran E. Orrantia-Borunda 《Letters in applied microbiology》2021,72(5):556-569
We described the bacterial diversity of walnut grove soils under organic and conventional farming. The bacterial communities of rhizospheric and nonrhizospheric soils of pecan tree (Carya illinoensis K. Koch) were compared considering two phenological stages (sprouting and ripening). Sixteen operational taxonomic units (OTUs) were identified significantly more abundant according to the plant development, only one according to the farming condition, and none according to the soil origin. The OTUs specificaly abundant according to plant development included Actinobateria (2) and Betaproteobacteria (1) related OTUs more abundant at the sprouting stage, while at the fruit ripening (FR) stage the more abundant OTUs were related to Actinobacteria (6), Alphaproteobacteria (6), and unclassified Bacteria (1). The Gaiellaceae OTU18 (Actinobacteria) was more abundant under conventional farming. Thus, our study revealed that the plant development stage was the main factor shaping the bacterial community structure, while less influence was noticed for the farming condition. The bacterial communities exhibited specific metabolic capacities, a large range of carbon sources being used at the FR stage. The identified OTUs specifically more abundant represent indicators providing useful information on soil condition, potential tools for the management of soil bacterial communities. 相似文献