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1.
Esterase 6 (E.C. 3.1.1.1) is an enzyme in the reproductive system of Drosophila melanogaster and is transferred from males to females at mating. This enzyme is conveyed during the first 3 min of a copulation lasting approximately 20 min and remains active in the female reproductive tract for 1–2 hr after mating. Males require 24–48 hr to recover premating levels of esterase 6 activity. These results suggest that the effect of esterase 6 on the rate of sperm loss in females, which extends to 4 days after mating, is indirect since activity in the female falls rapidly after insemination. It is suggested that esterase 6 may also be a part of a pheromone system which influences female reproductive behaviour. 相似文献
2.
Chen Z Kloek AP Cuzick A Moeder W Tang D Innes RW Klessig DF McDowell JM Kunkel BN 《The Plant journal : for cell and molecular biology》2004,37(4):494-504
AvrRpt2, a Pseudomonas syringae type III effector protein, functions from inside plant cells to promote the virulence of P. syringae pv. tomato strain DC3000 (PstDC3000) on Arabidopsis thaliana plants lacking a functional copy of the corresponding RPS2 resistance gene. In this study, we extended our understanding of AvrRpt2 virulence activity by exploring the hypothesis that AvrRpt2 promotes PstDC3000 virulence by suppressing plant defenses. When delivered by PstDC3000, AvrRpt2 suppresses pathogen-related (PR) gene expression during infection, suggesting that AvrRpt2 suppresses defenses mediated by salicylic acid (SA). However, AvrRpt2 promotes PstDC3000 growth on transgenic plants expressing the SA-degrading enzyme NahG, indicating that AvrRpt2 does not promote bacterial virulence by modulating SA levels during infection. AvrRpt2 general virulence activity does not depend on the RPM1 resistance gene, as mutations in RPM1 had no effect on AvrRpt2-induced phenotypes. Transgenic plants expressing AvrRpt2 displayed enhanced susceptibility to PstDC3000 strains defective in type III secretion, indicating that enhanced susceptibility of these plants is not because of suppression of defense responses elicited by other type III effectors. Additionally, avrRpt2 transgenic plants did not exhibit increased susceptibility to Peronospora parasitica and Erysiphe cichoracearum, suggesting that AvrRpt2 virulence activity is specific to P. syringae. 相似文献
3.
Background
The beneficial influence of social networks on health and wellbeing is well-established. In poor urban settlements in Bangladesh, BRAC’s Manoshi programme trains community health workers (CHWs) to support women through pregnancy, delivery and postpartum periods. This paper test the hypothesis that the introduction of CHWs as weak ties into the social networks of Manoshi members mediates improvements in maternal and neonatal health (MNH) best practices by providing support, facilitating ideational change, connecting mother to resources, and strengthening or countering the influence of strong ties.Methods
1000 women who had given birth in the last three months were identified and interviewed as part of ongoing monitoring of 5 poor urban settlements in Dhaka, Bangladesh. A social networks questionnaire was administered which elicited women’s perceived networks around pregnancy, delivery and post-partum periods. Mediation analysis was performed to test the hypothesis that penetration of Manoshi CHWs into women’s perceived networks has a beneficial effect on MNH best practises.Results
The presence and influence of Manoshi CHWs in women’s networks significantly mediated the effect of Manoshi membership on MNH best practices. Respondents who were Manoshi members and who listed Manoshi CHWs as part of their support networks were significantly more likely to deliver with a trained birth attendant (OR 3.61; 95%CI 2.36–5.51), to use postnatal care (OR 3.09; 95%CI 1.83–5.22), and to give colostrum to their newborn (OR 7.51; 95%CI 3.51–16.05).Conclusion
Manoshi has succeeded in penetrating the perceived pregnancy, delivery and post-partum networks of poor urban women through the introduction of trained CHWs. Study findings demonstrate the benefits of moving beyond urban health care delivery models that concentrate on the provision of clinical services by medical providers, to an approach that nurtures the power of social networks as a means to support the poorest and most marginalized in changing behaviour and effectively accessing appropriate maternal services. 相似文献4.
5.
Alayne L. Schroll Robert J. Hondal Stevenson Flemer Jr. 《Journal of peptide science》2012,18(3):155-162
In contrast to the large number of sidechain protecting groups available for cysteine derivatives in solid phase peptide synthesis, there is a striking paucity of analogous selenocysteine Se‐protecting groups in the literature. However, the growing interest in selenocysteine‐containing peptides and proteins requires a corresponding increase in availability of synthetic routes into these target molecules. It therefore becomes important to design new sidechain protection strategies for selenocysteine as well as multiple and novel deprotection chemistry for their removal. In this paper, we outline the synthesis of two new Fmoc selenocysteine derivatives [Fmoc‐Sec(Meb) and Fmoc‐Sec(Bzl)] to accompany the commercially available Fmoc‐Sec(Mob) derivative and incorporate them into two model peptides. Sec‐deprotection assays were carried out on these peptides using 2,2′‐dithiobis(5‐nitropyridine) (DTNP) conditions previously described by our group. The deprotective methodology was further evaluated as to its suitability towards mediating concurrent diselenide formation in oxytocin‐templated target peptides. Sec(Mob) and Sec(Meb) were found to be extremely labile to the DTNP conditions whether in the presence or absence of thioanisole, whereas Sec(Bzl) was robust to DTNP in the absence of thioanisole but quite labile in its presence. In multiple Sec‐containing model peptides, it was shown that bis‐Sec(Mob)‐containing systems spontaneously cyclize to the diselenide using 1 eq DTNP, whereas bis‐Sec(Meb) and Sec(Bzl) models required additional manipulation to induce cyclization. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
6.
Ke Hao Shaojie Peng Houxun Xing Yunxian Yu Aiqun Huang Xiumei Hong Yuanping Wang Changzhong Chen Binyan Wang Xuejun Zhang Jing Liu Guoying Zhu Yong Huo Dafang Chen Xiaotao Zhao Alayne Ronnenberg Di Wu Tianhua Niu Xiping Xu 《Obesity (Silver Spring, Md.)》2004,12(1):125-130
Objectives: Obesity is a complex trait that is affected by both environmental and genetic risk factors. The β3 adrenergic receptor (ADRB3) is expressed in adipose tissue and plays a role in energy metabolism. A missense mutation on codon 64 of this gene (W64R) is associated with receptor malfunction. Previous studies examining the relation between this polymorphism and obesity produced inconsistent findings. The current study assessed the association between the W64R genotype and obesity‐related phenotypes, including body weight, BMI, and serum triglycerides, cholesterol, and glucose. Research Methods and Procedures: We determined the ADRB3 W64R genotypes and fasting serum lipid and glucose concentrations for 695 hypertensive adults (336 men, 359 women) from a rural county in Anhui Province, China. Multivariate linear regression models were fit to detect associations between the genetic polymorphism and obesity‐related phenotypes. Results: The ADRB3 W64R polymorphism was significantly associated with body weight and BMI in men but not in women. After controlling for potential confounding variables, men who were homozygous for the R64 allele were 11.8 kg heavier (p < 0.001) and had a BMI that was 3.7 kg/m2 greater (p = 0.001) than men who were homozygous for the W64 allele. Serum concentrations of lipids and glucose were found not associated with the genetic polymorphism. Discussion: The ADRB3 R64 allele was associated with increased body weight and BMI in men but not in women. The genetic association was not modified by triglyceride, cholesterol, blood glucose, or blood pressure levels of the subjects. 相似文献
7.
Holocene vegetation history of the Sahel: pollen, sedimentological and geochemical data from Jikariya Lake, north-eastern Nigeria 总被引:1,自引:0,他引:1
Aim This study aims to separate regional and local controls on Holocene vegetation development and examine how well pollen records reflect climate change in a semi‐arid region. The relative importance of climate and human activity as agents of vegetation change in the Sahel during the late Holocene is also considered. Location Jikariya Lake, an inter‐dune depression in the Manga Grasslands of north‐eastern Nigeria. Methods Pollen and charcoal were used to provide a record of Holocene vegetation history. Palaeoclimate and hydrological changes were reconstructed from sedimentary and geochemical data. Regional and local influences were separated by comparing the evidence obtained from Jikariya Lake with previously published data from the Manga Grasslands. Results The Manga Grasslands experienced a prolonged wet period during the early and mid‐Holocene, during which swamp forest vegetation with Guinean affinities (Alchornea, Syzygium, Uapaca) occupied the inter‐dune depressions. However, variation in the pollen records between sites suggests that their establishment was dependent on conditions being locally favourable, rather than being directly coupled to regional climate. The pollen records from the Manga Grasslands are more consistent in suggesting the colonization of the dunefields by trees associated with Sudanian savanna (Combretaceae, Detarium) c. 8700 cal. yr bp . The Jikariya Lake pollen data are in accordance with the sedimentological and geochemical data from the region in indicating that the onset of arid conditions occurred progressively during the late Holocene (from c. 4700 cal. yr bp ). Abrupt changes in pollen stratigraphy, recorded at other Manga Grasslands sites 3500 cal. yr bp , appear to be the product of the local passing of ecological thresholds. The dunefield vegetation (Sahelian savanna) appears to have been resilient to (or at least palynologically silent regarding) to the climatic variability of the late Holocene. Main conclusions While climate appears to have been the primary control on vegetation development in the Manga Grasslands during the Holocene, local conditions (particularly depression size and sand influx) had a strong influence on the timing of pollen stratigraphic changes. Anthropogenic influences are difficult to detect, even during the late Holocene. 相似文献
8.
Karl A. Didier David Wilkie Iain Douglas-Hamilton Laurence Frank Nicholas Georgiadis Max Graham Festus Ihwagi Anthony King Alayne Cotterill Dan Rubenstein Rosie Woodroffe 《Biodiversity and Conservation》2009,18(7):1979-2000
Conservation projects may be reluctant to attempt Systematic Conservation Planning because existing methods are often prohibitive
in the time, money, data, and expertise they require. We tried to develop a “resource light” method for Systematic Conservation
Planning and applied it to the Ewaso Ngiro Landscape of central Kenya. Over a 6-month preparation period and 1-week participatory
workshop, we used expert assessments to select focal biodiversity features, set quantitative targets for these, map their
current distribution, vulnerability, potential for recovery, and conservation costs, and, finally, map cross-feature conservation
priorities. Preparation for and facilitation of the workshop required time investment by one part-time workshop coordinator,
eight workshop committee members, six ecosystem experts, and two GIS technicians. Total time investment was approximately
56.5 person-weeks spread over facilitators and 40 workshop participants. Monetary costs for the workshop were approximately
$US 42,000, excluding investments made by researchers previous to this project. Costs for a similar workshop could vary substantially,
depending on need to cover salaries, international travel, food and lodging, and the number of participants. To stay within
our resource constraints, we completed the exercise for only four of nine focal biodiversity features and did not negotiate
trade-offs between conservation and human land-uses or use planning software to identify “optimal networks” of conservation
areas. These were not considered critical for conservationists to try Systematic Conservation Planning, introduce landscape-scale
conservation concepts to stakeholders, and begin implementing landscape conservation strategies. Participants agreed that
further work would be needed to complete and update the planning process. Due to the lack of comparative cost data from similar
planning exercises, we cannot definitively conclude that our approach was “resource light”, although we suspect it is within
the constraints of most site-based conservation projects. 相似文献
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10.
For 802 women at initial follow-up after laser treatment of cervical lesions, 421 smears prepared using the Cervex brush were compared with 381 smears prepared using the combination of a Cytobrush plus an Ayre spatula. The smears were graded for adequacy, the presence of endocervical or metaplastic cells and the presence and degree of epithelial abnormalities. Endocervical or metaplastic cells were seen more often in Cytobrush-Ayre spatula smears (94.5%) as compared with Cervex brush smears (88.8%; P = .004). Also, the number of samples classed as inadequate was significantly greater with Cervex brush smears (4.0%) than with Cytobrush-Ayre spatula smears (0.3%; P = .0003). The number of smears showing dysplasia was too small to detect realistic differences between the two sampling methods. These findings suggest that, in women who have had laser treatment of the cervix, Cytobrush plus Ayre spatula sampling produces better-quality smears than does Cervex brush sampling, with regard to both adequacy and the presence of endocervical cells. 相似文献