نتایج جستجو برای: visitation time
تعداد نتایج: 1892986 فیلتر نتایج به سال:
EXECUTIVE SUMMARY Evaluating the effectiveness of maternal and child home visitation programs can be challenging. The complexity of program models, coupled with considerations of real-world program implementation, requires thoughtful and flexible evaluation strategies. Yet, meaningful evaluations of home visitation programs are not only feasible, but are essential as policymakers demand stronge...
Pollinators serve critical roles for the functioning of terrestrial ecosystems, and have an estimated annual value of over $150 billion for global agriculture. Mounting evidence from agricultural systems reveals that pollinators are declining in many regions of the world, and with a lack of information on whether pollinator communities in natural systems are following similar trends, identifyin...
Pollen limitation of plant reproduction occurs in many plant species, particularly those in fragmented habitat; however, causes of pollen limitation are often unknown. We investigated the relationship between pollen limitation and pollinator visitation in the purple coneflower, Echinacea angustifolia (Asteraceae), which grows in the extremely fragmented tall grass prairie of North America. Prev...
This paper evaluates early impacts of a home visiting program modeled after Healthy Families America on parenting behaviors in the first two years of life. It also proposes a framework for reconciling discrepant findings from randomized trials evaluating home visitation programs. A sample of 1173 families at risk for child abuse and neglect who met the criteria for Healthy Families New York (HF...
Bee species interactions can benefit plant pollination through synergistic effects and complementary effects, or can be of detriment to plant pollination through competition effects by reducing visitation by effective pollinators. Since specific bee interactions influence the foraging performance of bees on flowers, they also act as drivers to regulate the assemblage of flower visitors. We sele...
1. While many plant species offer rewards (e.g. nectar) to pollinators, some species, particularly in orchids, do not provide rewards. Ecological factors, such as interactions with rewarding co-flowering species may affect pollinator visitation rates to such deceptive species by influencing pollinator ability to learn to avoid deceptive plants (avoidance learning). 2. We tested the effect of fl...
BACKGROUND AND AIMS Studies of the effects of pollination on floral scent and bee visitation remain rare, particularly in agricultural crops. To fill this gap, the hypothesis that bee visitation to flowers decreases after pollination through reduced floral volatile emissions in highbush blueberries, Vaccinium corymbosum, was tested. Other sources of variation in floral emissions and the role of...
The present study investigates how visitation from parents impacts youths' mental health in the first two months of incarceration in a secure juvenile facility. A diverse sample of 276 male, newly incarcerated serious adolescent offenders (14-17 years) was interviewed over a 60-day period. Results indicate that youth who receive visits from parents report more rapid declines in depressive sympt...
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