Are Physician Assistants Needed in Guatemala? A Survey of Potential Urban and Rural Users.

Purpose: The shortage of trained health care personnel has been increasing worldwide. With the physician assistant (PA) profession, created in the United States in the 1960s, expanding globally, this study sought to ascertain whether PAs can be an innovative solution to this crisis.

Methods: We conducted a convenience sample survey to assess the need for and acceptability of future PA professionals in Guatemala.

N-P co-limitation of primary production and response of arthropods to N and P in early primary succession on Mount St. Helens volcano.

Background: The effect of low nutrient availability on plant-consumer interactions during early succession is poorly understood. The low productivity and complexity of primary successional communities are expected to limit diversity and abundance of arthropods, but few studies have examined arthropod responses to enhanced nutrient supply in this context. We investigated the effects of nitrogen (N) and phosphorus (P) addition on plant productivity and arthropod abundance on 24-yr-old soils at Mount St.

Comparative genome scan detects host-related divergent selection in the grasshopper Hesperotettix viridis.

In this study, we used a comparative genome scan to examine patterns of population differentiation with respect to host plant use in Hesperotettix viridis, a Nearctic oligophagous grasshopper locally specialized on various Asteraceae including Solidago, Gutierrezia, and Ericameria. We identified amplified fragment length polymorphism (AFLP) loci with significantly elevated F(ST) (outlier loci) in multiple different-host and same-host comparisons of populations while controlling for geographic distance. By comparing the number and identities of outlier loci in different-host vs.

Successional change in phosphorus stoichiometry explains the inverse relationship between herbivory and lupin density on Mount St. Helens.

Background: The average nitrogen-to-phosphorus ratio (NratioP) of insect herbivores is less than that of leaves, suggesting that P may mediate plant-insect interactions more often than appreciated. We investigated whether succession-related heterogeneity in N and P stoichiometry influences herbivore performance on N-fixing lupin (Lupinus lepidus) colonizing primary successional volcanic surfaces, where the abundances of several specialist lepidopteran herbivores are inversely related to lupin density and are known to alter lupin colonization dynamics. We examined larval performance in response to leaf nutritional characteristics using gelechiid and pyralid leaf-tiers, and a noctuid leaf-cutter.

When can herbivores slow or reverse the spread of an invading plant? A test case from Mount St. Helens.

Here we study the spatial dynamics of a coinvading consumer-resource pair. We present a theoretical treatment with extensive empirical data from a long-studied field system in which native herbivorous insects attack a population of lupine plants recolonizing a primary successional landscape created by the 1980 volcanic eruption of Mount St. Helens.

Linking community and ecosystem development on Mount St. Helens.

In the two decades following the 1980 eruption of Mount St. Helens in Washington State, the N2-fixing colonizer Lupinus lepidus is associated with striking heterogeneity in plant community and soil development. We report on differences in nutrient availability and plant tissue chemistry between older, dense patches (core) of L.