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.

Children as victims of violence: A national survey

Abstract: OBJECTIVE. The goal of this study was to gain a more comprehensive perspective on the scope, variety, and consequences of child victimization, which has been obscured by a fragmentation into specific problems like sexual abuse or kidnapping. METHODS. Two thousand children aged 10 to 16 years were interviewed in a national telephone survey of children. RESULTS. In the previous year, a quarter of the children had experienced a completed victimization, one in eight had experienced an injury, and one in a hundred required medical attention as a result. Nonfamily physical assaults were the most numerous. Contact sexual abuse occurred to 3.2% of girls and 0.6% of boys. There were also substantial numbers of incidents of attempted kidnappings and violence directed to children's genitals. CONCLUSION. The victimization of children occurs to a greater extent than has been previously reported and is poorly represented in official statistics. IMPLICATION. The authors argue for a more comprehensive interest in children's victimization including better national statistics about the problem. Language: en

Consistently dated Atlantic sediment cores over the last 40 thousand years

Abstract: Rapid changes in ocean circulation and climate have been observed in marine-sediment and ice cores over the last glacial period and deglaciation, highlighting the non-linear character of the climate system and underlining the possibility of rapid climate shifts in response to anthropogenic greenhouse gas forcing. To date, these rapid changes in climate and ocean circulation are still not fully explained. One obstacle hindering progress in our understanding of the interactions between past ocean circulation and climate changes is the difficulty of accurately dating marine cores. Here, we present a set of 92 marine sediment cores from the Atlantic Ocean for which we have established age-depth models that are consistent with the Greenland GICC05 ice core chronology, and computed the associated dating uncertainties, using a new deposition modeling technique. This is the first set of consistently dated marine sediment cores enabling paleoclimate scientists to evaluate leads/lags between circulation and climate changes over vast regions of the Atlantic Ocean. Moreover, this data set is of direct use in paleoclimate modeling studies.

Intramolecular, compound‐specific, and bulk carbon isotope patterns in C3 and C4 plants: a review and synthesis

Abstract: Studies using carbon isotope differences between C3 and C4 photosynthesis to calculate terrestrial productivity or soil carbon turnover assume that intramolecular isotopic patterns and isotopic shifts between specific plant components are similar in C3 and C4 plants. To test these assumptions, we calculated isotopic differences in studies measuring components from C3 or C4 photosynthesis. Relative to source sugars in fermentation, C3 -derived ethanol had less 13 C and C3 -derived CO2 had more 13 C than C4 -derived ethanol and CO2 . Both results agreed with intramolecular isotopic signatures in C3 and C4 glucose. Isotopic shifts between plant compounds (e.g. lignin and cellulose) or tissues (e.g. leaves and roots) also differed in C3 and C4 plants. Woody C3 plants allocated more carbon to 13 C-depleted compounds such as lignin or lipids than herbaceous C3 or C4 plants. This allocation influenced 13 C patterns among compounds and tissues. Photorespiration and isotopic fractionation at metabolic branch points, coupled to different allocation patterns during metabolism for C3 vs C4 plants, probably influence position-specific and compound-specific isotopic differences. Differing 13 C content of mobile and immobile compounds (e.g. sugars vs lignin) may then create isotopic differences among plant pools and along transport pathways. We conclude that a few basic mechanisms can explain intramolecular, compound-specific and bulk isotopic differences between C3 and C4 plants. Understanding these mechanisms will improve our ability to link bulk and compound-specific isotopic patterns to metabolic pathways in C3 and C4 plants. Contents Summary 371 I. Introduction 372 II. Methods and terminology 373 III. Results 373 IV. Discussion 376 V. Conclusions 382 Acknowledgements 382 References 382.

Assessing the response of area burned to changing climate in western boreal North America using a Multivariate Adaptive Regression Splines (MARS) approach

Abstract: Fire is a common disturbance in the North American boreal forest that influences ecosystem structure and function. The temporal and spatial dynamics of fire are likely to be altered as climate continues to change. In this study, we ask the question: how will area burned in boreal North America by wildfire respond to future changes in climate? To evaluate this question, we developed temporally and spatially explicit relationships between air temperature and fuel moisture codes derived from the Canadian Fire Weather Index System to estimate annual area burned at 2.5° (latitude x longitude) resolution using a Multivariate Adaptive Regression Spline (MARS) approach across Alaska and Canada. Burned area was substantially more predictable in the western portion of boreal North America than in eastern Canada. Burned area was also not very predictable in areas of substantial topographic relief and in areas along the transition between boreal forest and tundra. At the scale of Alaska and western Canada, the empirical fire models explain on the order of 82% of the variation in annual area burned for the period 1960-2002. July temperature was the most frequently occurring predictor across all models, but the fuel moisture codes for the months June through August (as a group) entered the models as the most important predictors of annual area burned. To predict changes in the temporal and spatial dynamics of fire under future climate, the empirical fire models used output from the Canadian Climate Center CGCM2 global climate model to predict annual area burned through the year 2100 across Alaska and western Canada. Relative to 1991-2000, the results suggest that average area burned per decade will double by 2041-2050 and will increase on the order of 3.5-5.5 times by the last decade of the 21st century. To improve the ability to better predict wildfire across Alaska and Canada, future research should focus on incorporating additional effects of long-term and successional vegetation changes on area burned to account more fully for interactions among fire, climate, and vegetation dynamics.

Nitrogen deposition onto the united states and western europe: synthesis of observations and models

Abstract: The documented acceleration of NH3 and NOx (NO NO2) emissions over the last 150 years has accelerated N deposition, compromising air and water quality and altering the functioning of terrestrial and aquatic ecosystems worldwide. To construct con- tinental-scale N budgets, we produced maps of N deposition fluxes from site-network observations for the United States and Western Europe. Increases in the rates of N cycling for these two regions of the world are large, and they have undergone profound modification of biospheric-atmospheric N exchanges, and ecosystem function. The maps are necessarily restricted to the network measured quantities and consist of statistically interpolated fields of aqueous NO3 and NH4, gaseous HNO3 and NO2 (in Europe), and particulate NO3 and NH4. There remain a number of gaps in the budgets, including organic N and NH3 de- position. The interpolated spatially continuous fields allow estimation of regionally inte- grated budget terms. Dry-deposition fluxes were the most problematic because of low station density and uncertainties associated with exchange mechanisms. We estimated dry N de- position fluxes by multiplying interpolated surface-air concentrations for each chemical species by model-calculated, spatially explicit deposition velocities. Deposition of the ox- idized N species, by-products of fossil-fuel combustion, dominate the U.S. N deposition budget with 2.5 Tg of NOy-N out of a total of 3.7-4.5 Tg of N deposited annually onto the conterminous United States. Deposition of the reduced species, which are by-products of farming and animal husbandry, dominate the Western European N-deposition budget with a total of 4.3-6.3 Tg N deposited each year out of a total of 8.4-10.8 Tg N. Western Europe receives five times more N in precipitation than does the conterminous United States. Estimated N emissions exceed measured deposition in the United States by 5.3- 7.81 Tg N, suggesting significant N export or under-sampling of urban influence. In Europe, estimated emissions better balance measured deposition, with an imbalance of between 0.63 and 2.88 Tg N, suggesting that much of the N emitted in Europe is deposited there, with possible N import from the United States. The sampling network in Europe includes urban influences because of the greater population density of Western Europe. Our analysis of N deposition for both regions was limited by sampling density. The framework we present for quantification of patterns of N deposition provides a constraint on our under- standing of continental biospheric-atmospheric N cycles. These spatially explicit wet and dry N fluxes also provide a tool for verifying regional and global models of atmospheric chemistry and transport, and they represent critical inputs into terrestrial models of bio- geochemistry.