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171.
Benjamin J. Ridenhour Michael A. Campitelli Jeffrey C. Kwong Laura C. Rosella Ben G. Armstrong Punam Mangtani Andrew J. Calzavara David K. Shay 《PloS one》2013,8(10)
Background
Estimates of the effectiveness of influenza vaccines in older adults may be biased because of difficulties identifying and adjusting for confounders of the vaccine-outcome association. We estimated vaccine effectiveness for prevention of serious influenza complications among older persons by using methods to account for underlying differences in risk for these complications.Methods
We conducted a retrospective cohort study among Ontario residents aged ≥65 years from September 1993 through September 2008. We linked weekly vaccination, hospitalization, and death records for 1.4 million community-dwelling persons aged ≥65 years. Vaccine effectiveness was estimated by comparing ratios of outcome rates during weeks of high versus low influenza activity (defined by viral surveillance data) among vaccinated and unvaccinated subjects by using log-linear regression models that accounted for temperature and time trends with natural spline functions. Effectiveness was estimated for three influenza-associated outcomes: all-cause deaths, deaths occurring within 30 days of pneumonia/influenza hospitalizations, and pneumonia/influenza hospitalizations.Results
During weeks when 5% of respiratory specimens tested positive for influenza A, vaccine effectiveness among persons aged ≥65 years was 22% (95% confidence interval [CI], −6%–42%) for all influenza-associated deaths, 25% (95% CI, 13%–37%) for deaths occurring within 30 days after an influenza-associated pneumonia/influenza hospitalization, and 19% (95% CI, 4%–31%) for influenza-associated pneumonia/influenza hospitalizations. Because small proportions of deaths, deaths after pneumonia/influenza hospitalizations, and pneumonia/influenza hospitalizations were associated with influenza virus circulation, we estimated that vaccination prevented 1.6%, 4.8%, and 4.1% of these outcomes, respectively.Conclusions
By using confounding-reducing techniques with 15 years of provincial-level data including vaccination and health outcomes, we estimated that influenza vaccination prevented ∼4% of influenza-associated hospitalizations and deaths occurring after hospitalizations among older adults in Ontario. 相似文献172.
Lewington-Pearce Leah Parker Ben Narwani Anita Nielsen Jens M. Kratina Pavel 《Oecologia》2020,192(2):515-527
Oecologia - Biodiversity loss and climate warming are occurring in concert, with potentially profound impacts on ecosystem functioning. We currently know very little about the combined effects of... 相似文献
173.
Commander Lucy Elizabeth Merino-Martín Luis Elliott Carole P. Miller Ben P. Dixon Kingsley Stevens Jason 《Plant and Soil》2020,457(1-2):113-129
Plant and Soil - Understanding limitations to plant recruitment is a key element in devising effective restoration of semi-arid ecosystems: only when these limitations are identified can management... 相似文献
174.
175.
Ben Ashby 《Evolution; international journal of organic evolution》2020,74(1):43-56
Sexually transmitted infections (STIs) are predicted to play an important role in the evolution of host mating strategies, and vice versa, yet our understanding of host-STI coevolution is limited. Previous theoretical work has shown mate choice can evolve to prevent runaway STI virulence evolution in chronic, sterilizing infections. Here, I generalize this theory to examine how a broader range of life-history traits influence coevolution; specifically, how host preferences for healthy mates and STI virulence coevolve when infections are acute and can cause mortality or sterility, and hosts do not form long-term sexual partnerships. I show that mate choice reduces both mortality and sterility virulence, with qualitatively different outcomes depending on the mode of virulence, costs associated with mate choice, recovery rates, and host lifespan. For example, fluctuating selection—a key finding in previous work—is most likely when hosts have moderate lifespans, STIs cause sterility and long infections, and costs of mate choice are low. The results reveal new insights into the coevolution of mate choice and STI virulence as different life-history traits vary, providing increased support for parasite-mediated sexual selection as a potential driver of host mate choice, and mate choice as a constraint on the evolution of virulence. 相似文献
176.
Rubén Ortega-Álvarez Esteban Berrones Benítez Israel Medina Mena José Jaime Zúñiga-Vega 《Ibis》2020,162(4):1262-1278
The simultaneous effects of habitat traits and interspecific interactions determine the occurrence and habitat use of wildlife populations. However, little research has been devoted to examining spatial co-occurrence among closely related species while considering the effect of habitat variation and imperfect detectability of species in the field. In this study, we focused on migratory and resident 'wood-warblers' that coexist during the winter in a Neotropical working landscape in southern Mexico to understand if habitat occupancy of resident wood-warblers is influenced by habitat characteristics and by the presence of other species of resident and migratory wood-warblers. For this purpose, we implemented two-species occupancy models, which account for the imperfect detectability of these birds in the field. Our results revealed that habitat occupancy of resident wood-warblers was positively influenced by the presence of other closely related species (both migratory and resident). These positive relationships may be explained by the fact that different species of wood-warblers frequently participate in mixed-species flocks. However, these patterns of species co-occurrence were more evident among resident species than between migratory and resident species, which may be explained by micro-habitat segregation and differences in behaviours between resident and migratory wood-warblers. We also found that some habitat characteristics may mediate the observed patterns of species co-occurrence. Specifically, sites with larger trees were associated with the co-occurrence of some species of resident wood-warblers. In addition, we discuss the possibility that species co-occurrence might be the result of shared preferences for environmental factors that we did not consider. Our study highlights the importance of the interplay between species co-occurrence and habitat traits in determining the presence and habitat use of resident birds in Neotropical working landscapes. 相似文献
177.
178.
Salma Kloula Ben Ghorbal Abdelwaheb Chatti Mohamed Marwan Sethom Lobna Maalej Mouadh Mihoub Sana Kefacha Moncef Feki Ahmed Landoulsi Abdennaceur Hassen 《Current microbiology》2013,67(1):112-117
The changes in lipid composition enable the micro-organisms to maintain membrane functions in the face of environmental fluctuations. The relationship between membrane fatty acid composition and UV-C stress was determined for mid-exponential phase and stationary phase Pseudomonas aeruginosa. The total lipids were obtained by dichloromethane/methanol (3:1) and were quantified by GC. The TLC analysis of phospholipids showed the presence of three major fractions phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. Significant modifications, as manifested by an increase of UFA, were obtained. Interestingly, this microorganism showed a remarkable capacity for recovery from the stressful effects of UV-C. 相似文献
179.
Donald G Newman Ben D Bell Phillip J Bishop Rhys Burns Amanda Haigh Rodney A Hitchmough 《New Zealand journal of zoology.》2013,40(2):121-130
Abstract A reappraisal of the conservation status of the New Zealand frog fauna is presented using the 2008 version of the New Zealand Threat Classification System. Of New Zealand's four extant endemic species, three are judged to be ‘Threatened’ (Leiopelma hamiltoni being ‘Nationally Critical’, and L. pakeka and L. archeyi being ‘Nationally Vulnerable’) and one ‘At Risk’ (L. hochstetteri ‘Declining’). Three Leiopelma species are listed as extinct—they are known from bone deposits in caves throughout the country until some time in the last 1000 years. Three introduced and naturalised Litoria species are abundant in New Zealand although two (L. aurea and L. raniformis) are threatened in their country of origin (Australia). An additional unidentified frog taxon from northern Great Barrier Island is listed as ‘Data Deficient’. 相似文献
180.
Barbara Cheney Paul M. Thompson Simon N. Ingram Philip S. Hammond Peter T. Stevick John W. Durban Ross M. Culloch Simon H. Elwen Laura Mandleberg Vincent M. Janik Nicola J. Quick Valentina ISLAS‐Villanueva Kevin P. Robinson Marina Costa Sonja M. Eisfeld Alice Walters Charlie Phillips Caroline R. Weir Peter G.H. Evans Pia Anderwald Robert J. Reid James B. Reid Ben Wilson 《Mammal Review》2013,43(1):71-88
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