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1.
Am Nat ; 202(2): 152-165, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37531276

RESUMO

AbstractAbiotic factors (e.g., temperature, precipitation) vary markedly along elevational gradients and differentially affect major groups of pollinators. Ectothermic bees, for example, are impeded in visiting flowers by cold and rainy conditions common at high elevations, while endothermic hummingbirds may continue foraging under such conditions. Despite the possibly far-reaching effects of the abiotic environment on plant-pollinator interactions, we know little about how these factors play out at broad ecogeographic scales. We address this knowledge gap by investigating how pollination systems vary across elevations in 26 plant clades from the Americas. Specifically, we explore Cruden's 1972 hypothesis that the harsh montane environment drives a turnover from insect to vertebrate pollination at higher elevations. We compared the elevational distribution and bioclimatic attributes for a total of 2,232 flowering plants and found that Cruden's hypothesis holds only in the tropics. Above 30°N and below 30°S, plants pollinated by vertebrates (mostly hummingbirds) tend to occur at lower elevations than those pollinated by insects. We hypothesize that this latitudinal transition is due to the distribution of moist, forested habitats favored by vertebrate pollinators, which are common at high elevations in the tropics but not in the temperate Americas.


Assuntos
Altitude , Polinização , Abelhas , Animais , Flores , Ecossistema , Insetos , Plantas , Aves , América
2.
Am J Bot ; 109(6): 1047-1055, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35471733

RESUMO

PREMISE: A switch in pollinator can occur when a plant lineage enters a new habitat where the ancestral pollinator is less common, and a novel pollinator is more common. Because pollinator communities vary according to environmental tolerances and availability of resources, there may be consistent associations between pollination mode and specific regions and habitats. Such associations can be studied in lineages that have experienced multiple pollinator transitions, representing evolutionary replicates. METHODS: Our study focused on a large clade of Penstemon wildflower species in western North America, which has repeatedly evolved hummingbird-adapted flowers from ancestral bee-adapted flowers. For each species, we estimated geographic ranges from occurrence data and inferred environmental niches from climate, topographical, and soil data. Using a phylogenetic comparative approach, we investigated whether hummingbird-adapted species occupy distinct geographic regions or habitats relative to bee-adapted species. RESULTS: Hummingbird-adapted species occur at lower latitudes and lower elevations than bee-adapted species, resulting in a difference in their environmental niche. Bee-adapted species sister to hummingbird-adapted species are also found in relatively low elevations and latitudes, similar to their hummingbird-adapted sister species, suggesting ecogeographic shifts precede pollinator divergence. Sister species pairs-regardless of whether they differ in pollinator-show relatively little geographic range overlap. CONCLUSIONS: Adaptation to a novel pollinator may often occur in geographic and ecological isolation from ancestral populations. The ability of a given lineage to adapt to novel pollinators may critically depend on its ability to colonize regions and habitats associated with novel pollinator communities.


Assuntos
Aves/fisiologia , Penstemon/fisiologia , Polinização , Altitude , Animais , Abelhas/fisiologia , Evolução Biológica , Ecossistema , Flores/anatomia & histologia , América do Norte , Filogenia , Polinização/fisiologia
4.
Addiction ; 110(9): 1404-15, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25913697

RESUMO

BACKGROUND AND AIMS: Brief alcohol interventions in medical settings are efficacious in improving self-reported alcohol consumption among those with low-severity alcohol problems. Screening, Brief Intervention and Referral to Treatment initiatives presume that brief interventions are efficacious in linking patients to higher levels of care, but pertinent evidence has not been evaluated. We estimated main and subgroup effects of brief alcohol interventions, regardless of their inclusion of a referral-specific component, in increasing the utilization of alcohol-related care. METHODS: A systematic review of English language papers published in electronic databases to 2013. We included randomized controlled trials (RCTs) of brief alcohol interventions in general health-care settings with adult and adolescent samples. We excluded studies that lacked alcohol services utilization data. Extractions of study characteristics and outcomes were standardized and conducted independently. The primary outcome was post-treatment alcohol services utilization assessed by self-report or administrative data, which we compared across intervention and control groups. RESULTS: Thirteen RCTs met inclusion criteria and nine were meta-analyzed (n = 993 and n = 937 intervention and control group participants, respectively). In our main analyses the pooled risk ratio (RR) was = 1.08, 95% confidence interval (CI) = 0.92-1.28. Five studies compared referral-specific interventions with a control condition without such interventions (pooled RR = 1.08, 95% CI = 0.81-1.43). Other subgroup analyses of studies with common characteristics (e.g. age, setting, severity, risk of bias) yielded non-statistically significant results. CONCLUSIONS: There is a lack of evidence that brief alcohol interventions have any efficacy for increasing the receipt of alcohol-related services.


Assuntos
Transtornos Relacionados ao Uso de Álcool/terapia , Aconselhamento/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto , Encaminhamento e Consulta/estatística & dados numéricos , Aconselhamento/métodos , Humanos , Transtornos Relacionados ao Uso de Substâncias/terapia
5.
Implement Sci ; 7: 96, 2012 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-23062065

RESUMO

BACKGROUND: All investigators seeking funding to conduct implementation research face the challenges of preparing a high-quality proposal and demonstrating their capacity to conduct the proposed study. Applicants need to demonstrate the progressive nature of their research agenda and their ability to build cumulatively upon the literature and their own preliminary studies. Because implementation science is an emerging field involving complex and multilevel processes, many investigators may not feel equipped to write competitive proposals, and this concern is pronounced among early stage implementation researchers. DISCUSSION: This article addresses the challenges of preparing grant applications that succeed in the emerging field of dissemination and implementation. We summarize ten ingredients that are important in implementation research grants. For each, we provide examples of how preliminary data, background literature, and narrative detail in the application can strengthen the application. SUMMARY: Every investigator struggles with the challenge of fitting into a page-limited application the research background, methodological detail, and information that can convey the project's feasibility and likelihood of success. While no application can include a high level of detail about every ingredient, addressing the ten ingredients summarized in this article can help assure reviewers of the significance, feasibility, and impact of the proposed research.


Assuntos
Organização do Financiamento , Pesquisa sobre Serviços de Saúde/organização & administração , Projetos de Pesquisa , Pesquisa Translacional Biomédica/organização & administração , Redação , Comportamento Cooperativo , Medicina Baseada em Evidências , Humanos , Inovação Organizacional
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