University of New Hampshire

About: University of New Hampshire is a education organization based out in Durham, New Hampshire, United States. It is known for research contribution in the topics: Population & Solar wind. The organization has 9379 authors who have published 24025 publications receiving 1020112 citations. The organization is also known as: UNH.

Effects of Habitat Features and Landscape Composition on the Population Structure of a Common Aquatic Turtle in a Region Undergoing Rapid Development

Abstract: We investigated the demography of a common aquatic turtle (Chrysemys picta) along a gradient of urbanization in southeastern New Hampshire. Using a geographic information system and live trapping of turtles, we compared the proportion of males, the proportion of adults, and the relative abundance of turtles in 37 ponds. We used satellite images, aerial photographs, and field visits to describe pond-specific features and habitat composition up to 2000 m from the perimeter of each pond. The proportion of males was positively associated with the percentage of forest cover within 500 m, greater road density within 100 m, and an index of predator activity at a pond. The proportion of adults in a population was associated with road density within 250 m of the pond and the percentage of the pond perimeter that was forested. Abnormal population structures associated with greater road densities did not necessarily result in lower abundances of turtles in ponds. Turtle abundance increased as the distance to neighboring wetlands decreased and the amount of nesting habitat near pond edges increased. Pond-specific features also affected turtle abundance where populations were larger in ponds with organic substrates and abundant coverage by shoreline vegetation than in ponds lacking these features. Few turtles were encountered in ponds with an abundance of herbaceous emergent vegetation, and fewer turtles were captured during a summer with abundant precipitation. Suburban and urban developments, with dense road networks and abundant populations of generalist predators (especially the raccoon, Procyon lotor), can alter the structure of aquatic turtle populations. Although these alterations may not result in immediate changes in turtle abundance within a specific population, we suspect that the reduction in recruitment caused by habitat alterations will eventually reduce or eliminate local populations. Even though there are life-history differences among species of turtles, our results may provide new insight into the causes of recent declines of other turtles.

Turbulence transport throughout the heliosphere

Abstract: [1] We employ a turbulence transport model to compute distributions of turbulence throughout the heliosphere. The model determines the radial dependence of three (coupled) quantities that characterize interplanetary turbulence, the energy per unit mass, the cross helicity or Alfvenicity, and a similarity length scale. A fourth integrated quantity, the plasma temperature, is modified by heat deposition due to turbulent dissipation. The model includes advection, expansion, and reflection effects as well as the tendency toward dynamic alignment, and a von Karman type dissipation function that represents decay of turbulence due to cascade to small scales. Two types of forcing are also featured, one a simple model of stream shear, and the other a driving in the outer heliosphere associated with wave energy injection due to pickup protons of interstellar origin. Parameters for the model have been tuned using observation data from Voyager and Ulysses. We analyze the constraining observations to provide boundary conditions and parameters that vary with heliocentric latitude, with some extrapolations. The fully assembled model permits the computation of the distribution of turbulence throughout the entire heliosphere, and we present solutions for several appropriate parameter sets.

X-rated material and perpetration of sexually aggressive behavior among children and adolescents: is there a link?

Abstract: Longitudinal linkages between intentional exposure to x-rated material and sexually aggressive behavior were examined among youth 10-15 year olds surveyed nationally in the United States. At Wave 1 in 2006, participants (n = 1,588) were queried about these exposures and outcomes in the preceding 12 months. Wave 2 data (n = 1,206) were collected approximately 12 months after Wave 1 and Wave 3 data (n = 1,159) were collected approximately 24 months after Wave 1. Thus, data for this project represent a 36-month time frame. A marginal model with generalized estimating equations was used to represent the population-average odds of sexually aggressive behavior over the 36 months as a function of exposure to x-rated material over the same time and to account for clustering in the data within person over time. An average of 5% of youth reported perpetrating sexually aggressive behavior and 23% of youth reported intentional exposure to x-rated material. After adjusting for other potentially influential proximal (i.e., sexual aggression victimization) and distal characteristics (e.g., substance use), we found that intentional exposure to violent x-rated material over time predicted an almost 6-fold increase in the odds of self-reported sexually aggressive behavior (aOR: 5.8, 95% CI: 3.2, 10.5), whereas exposure to nonviolent x-rated material was not statistically significantly related (aOR: 1.7, 95% CI: 0.94, 2.9). Associations were similar for boys and girls (boys nonviolent x-rated material aOR = 2.0, 95% CI: 0.8, 4.7; violent x-rated material aOR = 6.5, 95% CI: 2.7, 15.3; girls nonviolent x-rated material aOR = 1.2, 95% CI: 0.5, 3.2; violet x-rated material aOR = 6.1, 95% CI: 2.5, 14.8).

Structures and Spectral Variations of the Outer Heliosphere in IBEX Energetic Neutral Atom Maps

Abstract: The Interstellar Boundary Explorer (IBEX) has obtained all-sky images of energetic neutral atoms emitted from the heliosheath, located between the solar wind termination shock and the local interstellar medium (LISM). These flux maps reveal distinct nonthermal (0.2 to 6 kilo–electron volts) heliosheath proton populations with spectral signatures ordered predominantly by ecliptic latitude. The maps show a globally distributed population of termination-shock–heated protons and a superimposed ribbonlike feature that forms a circular arc in the sky centered on ecliptic coordinate (longitude λ, latitude β) = (221°, 39°), probably near the direction of the LISM magnetic field. Over the IBEX energy range, the ribbon’s nonthermal ion pressure multiplied by its radial thickness is in the range of 70 to 100 picodynes per square centimeter AU (AU, astronomical unit), which is significantly larger than the 30 to 60 picodynes per square centimeter AU of the globally distributed population.