11,957 research outputs found
Behind at the Starting Line: Poverty Among Hispanic Infants
In this brief, authors Daniel Lichter, Scott Sanders, and Kenneth Johnson examine the economic circumstances of Hispanic infants using the Census Bureau’s American Community Survey annual microdata files from 2006 through 2010. They report that a disproportionate share of Hispanic infants start life’s race behind the starting line, poor and disadvantaged—an important finding because the proportion of all U.S. births that are Hispanic is growing rapidly. The poverty risk is especially high among rural Hispanic infants and those in new destinations. Despite higher poverty risks, Hispanic infants receive less governmental assistance. High Hispanic infant poverty has immediate and long-term consequences for infants and the nation. Failing to invest in families and children now has long-term consequences because early childhood poverty tends to set into motion a series of lifecycle disadvantages (such as insufficient parenting, bad neighborhoods, underfunded schools, and poor health care) that greatly increases the likelihood of poverty in adulthood. The authors conclude that whether today’s Hispanic children will assimilate into America’s economic mainstream is an open question, but the Hispanic infants who will help reshape America’s future require public policy attention now
Carbon fixation, flux and burial efficiency in two contrasting eutrophic lakes in the UK (Rostherne Mere & Tatton Mere)
Much of the current research into the processing and storage of carbon (C) in small lakes has focused on arctic and boreal lake systems, due to their global abundance. However this has led to an imbalance in the interpretation of lake functioning. Oligotrophic lakes are prevalent in the arctic and boreal zone, but are typically net heterotrophic due to loading of catchment-derived dissolved organic carbon (DOC) which alters their metabolic balance. In comparison, temperate lake systems tend to be more nutrient rich, typically due to anthropogenic activity, and would therefore be expected to exhibit the signs of net autotrophy, as a result of higher rates of gross primary production (GPP) and lower rates of catchment-derived DOC potentially subsidising respiration (R).
In order to test the hypothesis that temperate, eutrophic lakes are net autotrophic (GPP > R) on an annual basis the C-dynamics of Rostherne Mere (maximum depth, zm, 31 m) and Tatton Mere (zm = 11 m), two monomictic Cheshire-Shropshire meres, were quantified over an 18 months period from 2010 2012. This monitoring study used high-resolution (hourly) oxygen (O2) sonde measurements, combined with high-resolution data from an automated on-lake monitoring buoy at Rostherne Mere (as part of the national UKLEON lake network) to calculate rates of epilimnion C-fixation. For both lakes, sediment traps were also used to determine water column C-flux and sediment core data to establish C-burial efficiency of these strongly stratifying lakes. Water column profiles of dissolved O2 and CO2 was also measured at 2 4 weekly intervals across both lakes. Particular attention was focused on: i) the long term C-storage of eutrophic, monomictic lakes; ii) up-scaling C-accumulation estimates from these two meres to the Cheshire-Shropshire meres region and all UK eutrophic waters; and iii) methodological sensitivity for estimating C-fixation, flux and burial efficiency and upscaling C-accumulation estimates. The results show that both lakes are net autotrophic on an annual basis, on average fixing 121 ± 2 g C m-2 yr-1 and sequestering 68 ± 4 g C m-2 yr-1, a C-burial efficiency of ~60%.
If up-scaled to the Cheshire-Shropshire meres region, annual C-accumulation was estimated to be 506 ± 32 t C yr-1 or 0.05 ± 0.001 Mt C since 1900. From this, it was estimated that UK eutrophic waters could be sequestering 0.12 ± 0.01 Mt C yr-1 or 13.3 ± 0.2 Mt C since 1900. Annual UK CO2 emissions are ~128.85 Mt C yr-1, therefore UK eutrophic waters currently offset 0.09% of yearly UK CO2 emissions.
Despite the finding that eutrophic, stratifying lakes have high C-fixation and sequestration values, lakes in other areas of the globe such as the arctic and boreal zones are typically a more important long term C-sink as they are far more abundant within the landscape and local soils are typically very poor within low C retention rates. Further investigation is needed into how lakes function on a regional and national scale, the importance of lake type and number when up-scaling C accumulation estimates and the potential impact on future C accumulation as a result of a changing environment and supra-regional policies in areas such as Europe
A Multi-Parameter Investigation of Gravitational Slip
A detailed analysis of gravitational slip, a new post-general relativity
cosmological parameter characterizing the degree of departure of the laws of
gravitation from general relativity on cosmological scales, is presented. This
phenomenological approach assumes that cosmic acceleration is due to new
gravitational effects; the amount of spacetime curvature produced per unit mass
is changed in such a way that a universe containing only matter and radiation
begins to accelerate as if under the influence of a cosmological constant.
Changes in the law of gravitation are further manifest in the behavior of the
inhomogeneous gravitational field, as reflected in the cosmic microwave
background, weak lensing, and evolution of large-scale structure. The new
parameter, , is naively expected to be of order unity. However, a
multiparameter analysis, allowing for variation of all the standard
cosmological parameters, finds that
where corresponds to a CDM universe under general
relativity. Future probes of the cosmic microwave background (Planck) and
large-scale structure (Euclid) may improve the limits by a factor of four.Comment: 7 pages, 9 figures, colo
Tourist Attitudes toward Elk Management in the Pine Ridge Region of Northwestern Nebraska
We interviewed 200 tourists at Fort Robinson State Park and Chadron State Park in the Pine Ridge region of northwestern Nebraska during July and August of 1997 to determine attitudes toward elk (Cervus elaphus) and elk management in Nebraska. Fifty-nine percent of the respondents were aware that elk occupied the Pine Ridge, 95% favored free-ranging elk, and 55% favored hunting as a means of managing the population. Nebraska residents were more aware of elk and elk hunting in the Pine Ridge than were nonresidents. Also, more residents had observed elk and were willing to drive longer distances to view elk in the Pine Ridge. Respondents in older age groups (55–64) were more knowledgeable about elk. More urban tourists were in favor of elk than those from rural communities, but attitudes toward elk hunting were similar between urban and rural residents. Seventy-six percent of respondents wanted an increase in the population of elk. Men were more aware of elk populations than women and more supportive of hunting as the best method to manage the population. We found no differences between gender for maintaining free-ranging elk, knowledge of hunting seasons, or willingness to drive, pay, or spend time to view elk. Our results revealed that tourists had positive attitudes toward free-ranging elk and management practices in Nebraska. Elk herds should be managed to provide maximum opportunity for both consumptive and non-consumptive uses while minimizing negative impacts to property owners and the ecosystem
Tourist Attitudes toward Elk Management in the Pine Ridge Region of Northwestern Nebraska
We interviewed 200 tourists at Fort Robinson State Park and Chadron State Park in the Pine Ridge region of northwestern Nebraska during July and August of 1997 to determine attitudes toward elk (Cervus elaphus) and elk management in Nebraska. Fifty-nine percent of the respondents were aware that elk occupied the Pine Ridge, 95% favored free-ranging elk, and 55% favored hunting as a means of managing the population. Nebraska residents were more aware of elk and elk hunting in the Pine Ridge than were nonresidents. Also, more residents had observed elk and were willing to drive longer distances to view elk in the Pine Ridge. Respondents in older age groups (55–64) were more knowledgeable about elk. More urban tourists were in favor of elk than those from rural communities, but attitudes toward elk hunting were similar between urban and rural residents. Seventy-six percent of respondents wanted an increase in the population of elk. Men were more aware of elk populations than women and more supportive of hunting as the best method to manage the population. We found no differences between gender for maintaining free-ranging elk, knowledge of hunting seasons, or willingness to drive, pay, or spend time to view elk. Our results revealed that tourists had positive attitudes toward free-ranging elk and management practices in Nebraska. Elk herds should be managed to provide maximum opportunity for both consumptive and non-consumptive uses while minimizing negative impacts to property owners and the ecosystem
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