121 research outputs found
Agroforestry interactions and soil water use in watersheds under corn-soybean management
Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Agroforestry and grass buffer practices reduce non point source pollution from corn-soybean watersheds, yet little is known about the processes and mechanisms involved. The objective of this study was to compare the soil water dynamics in crop, grass, and agroforestry areas throughout the growing season to understand soil water use and recharge differences among the treatments. The study was conducted on two corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotational watersheds with grass and agroforestry buffers at the Greenley Research Center, Knox County, MO. Campbell soil moisture sensors were installed in crop, grass, and agroforestry areas with six replications at 5, 10, 20, and 40 cm depths to record volumetric soil water content at 10 minute intervals for 2004 through 2007. Initial soil moisture was lower in tree and grass buffer areas than crop areas probably due to water use by the permanent vegetation before crops were established. The differences were larger for shallower depths as compared to the 40 cm depth. The trend continued throughout the growing season. Weekly soil moisture content was significantly higher in the crop treatment as compared to the buffer treatments. During rain events water content increased in all depths and treatments and the differences in water content among treatments diminished. At the end of the growing season, soil water content increased when water use was low and as the profile recharged by rain events. The results of the study suggest that establishment of grass and agroforestry buffers help reduce non point source pollution from row crop agriculture by using additional water that would have otherwise have been lost in runoff carrying sediments, nutrients, and pesticides.Ranjith P. Udawatta (1,2), Stephen H. Anderson (1), Peter P. Motavalli (1), and Harold E. Garrett (2) ; 1. Department of Soil, Environmental and Atmospheric Sciences. 2. Center for Agroforestry, and University of Missouri, Columbia, MO 65211.Includes bibliographical references
Signature Change in Noncommutative FRW Cosmology
The conditions for which the no boundary proposal may have a classical
realization of a continuous change of signature, are investigated for a
cosmological model described by FRW metric coupled with a self interacting
scalar field, having a noncommutative phase space of dynamical variables. The
model is then quantized and a good correspondence is shown between the
classical and quantum cosmology indicating that the noncommutativity does not
destruct the classical-quantum correspondence. It is also shown that the
quantum cosmology supports a signature transition where the bare cosmological
constant takes a vast continuous spectrum of negative values. The bounds of
bare cosmological constant are limited by the values of noncommutative
parameters. Moreover, it turns out that the physical parameters are constrained
by the noncommutativity parametres.Comment: 15 pages, 4 figures, Minor revision, references adde
Updated European Consensus Statement on diagnosis and treatment of adult ADHD
Background Attention-deficit/hyperactivity disorder (ADHD) is among the most common psychiatric disorders of childhood that often persists into adulthood and old age. Yet ADHD is currently underdiagnosed and undertreated in many European countries, leading to chronicity of symptoms and impairment, due to lack of, or ineffective treatment, and higher costs of illness. Methods The European Network Adult ADHD and the Section for Neurodevelopmental Disorders Across the Lifespan (NDAL) of the European Psychiatric Association (EPA), aim to increase awareness and knowledge of adult ADHD in and outside Europe. This Updated European Consensus Statement aims to support clinicians with research evidence and clinical experience from 63 experts of European and other countries in which ADHD in adults is recognized and treated. Results Besides reviewing the latest research on prevalence, persistence, genetics and neurobiology of ADHD, three major questions are addressed: (1) What is the clinical picture of ADHD in adults? (2) How should ADHD be properly diagnosed in adults? (3) How should adult ADHDbe effectively treated? Conclusions ADHD often presents as a lifelong impairing condition. The stigma surrounding ADHD, mainly due to lack of knowledge, increases the suffering of patients. Education on the lifespan perspective, diagnostic assessment, and treatment of ADHD must increase for students of general and mental health, and for psychiatry professionals. Instruments for screening and diagnosis of ADHD in adults are available, as are effective evidence-based treatments for ADHD and its negative outcomes. More research is needed on gender differences, and in older adults with ADHD. (c) 2018 The Author(s). Published by Elsevier Masson SAS.Peer reviewe
Fashioning Entitlements: A Comparative Law and Economic Analysis of the Judicial Role in Environmental Centralization in the U.S. and Europe
This paper identifies and evaluates, from an economic point of view, the role of the judiciary the steady shift of environmental regulatory authority to higher, more centralized levels of government in both the U.S. and Europe. We supply both a positive analysis of how the decisions made by judges have affected the incentives of both private and public actors to pollute the natural environment, and normative answers to the question of whether judges have acted so as to create incentives that move levels of pollution in an efficient direction, toward their optimal, cost-minimizing (or net-benefit-maximizing) levels. Highlights of the analysis include the following points: 1) Industrial-era local (state or national) legislation awarding entitlements to pollute was almost certainly inefficient due to a fundamental economic obstacle faced by those who suffer harm from the over-pollution of publicly owned natural resources: the inability to monetize and credibly commit to repay the future economic value of reducing pollution. 2) When industrial era pollution spilled across state lines in the US, the federal courts, in particular the Supreme Court, fashioned a federal common law of interstate nuisance that set up essentially the same sort of blurry, uncertain entitlements to pollute or be free of pollution that had been created by the state courts in resolving local pollution disputes. We argue that for the typical pollution problem, a legal regime of blurry interstate entitlements - with neither jurisdiction having a clear right either to pollute or be free of pollution from the other - is likely to generate efficient incentives for interjursidictional bargaining, even despite the public choice problems besetting majority-rule government. Interestingly, a very similar system of de facto entitlements arose and often stimulated interjursidictional bargaining in Europe as well as in the U.S. 3) The US federal courts have generally interpreted the federal environmental statutes in ways that give clear primacy to federal regulators. Through such judicial interpretation, state and local regulators face a continuing risk of having their decisions overridden by federal regulators. This reduces the incentives for regulatory innovation at the state and local level. Judicial authorization of federal overrides has thus weakened the economic rationale for cooperative federalism suggested by economic models of principal-agent relationships. As a result of the principle of attribution, there is less risk in Europe that (like in the US) courts would enlarge the federal purview and thereby limit the powers of the Member States. Despite this principle, the power of the European bureaucracy (that is, the European Commission) has steadily increased and led to a steady shift of environmental regulatory competencies to the European level. This shift is only sometimes normatively desirable, and yet there is little that the ECJ can or will do to slow it
Apparent Soil Electrical Conductivity Used to Determine Soil Phosphorus Variability in Poultry Litter-Amended Pastures
The objectives of this research were to determine the relationship between soil apparent electrical conductivity (ECa) and soil P distribution, and to compare the effectiveness of noncontact mobile electromagnetic induction (EM) and direct contact methods for relating ECa to soil P. Studies were conducted at two locations in Southwest Missouri on a longterm forage fertility plot site and three 1 to 1.5 ha sites within beef cattle pasture fields, all having received long-term poultry litter applications. For the long-term plot site, both the direct contact ECa sensor deep reading and the EM-38 (Geonics) sensor in the shallow mode had significant positive correlations with soil test Bray-1 P at both the 0 to 5 and 5 to 15 cm sampling depths. Significant spatial variation in soluble, soil test Bray-1 and total P were observed by landscape position within pasture fields. In general, soil ECa was not significantly correlated with soluble, soil test Bray-1 and total P at each individual pasture site, but when data was combined over all three sites, significant relationships were observed between ECa measured by the EM-38 sensor and soil soluble P, soil test Bray-1 P and total P, especially when the vertical (deep) mode was used. The difference in performance of the two sensors between the two studies was attributed to the proportion of coarse fragments contained in the soils and soil water content. These results suggest that soil ECa measurements may provide some useful information for evaluating spatial variation in soil P due to manure applications. However, further research is needed to assess the processes and factors affecting this relationship before it can be recommended for use for improved soil P management in individual farm fields with varying environmental conditions and management practices
An overview of exposure parameters, dose measurements and strategies for dose reduction in pediatric CT examinations
CT scanning technology is a valuable tool to diagnose many diseases; however, the level
of the radiation dose is a source of concern, especially for children. CT scan systems and
dose measurement methods have evolved over the years; but reported pediatric effective
doses (EDs) have sometimes exceeded the annual dose limit recommended by the ICRP (1 mSv
per year for persons under 18 years) (ICRP, 2007a).
Efforts have been made to reduce organ doses and EDs by adjusting the scan parameters.
This paper describes the determinants of the ED, and the dose reduction techniques in
pediatric imaging from the early age of CT examinations until now. The first
epidemiological results regarding the associated risk of cancer are also briefly
presented
Dose estimation in reference and non-reference pediatric patients undergoing computed tomography examinations: a Monte Carlo study
The global increase in the number of computed tomography (CT) examinations have enhanced
concerns regarding stochastic radiation risks to patients, especially for children.
Considering that cancer risk is cumulative over a lifetime and each CT examination
contributes to the lifetime exposure, there is a need for a better understanding of
radiation-induced cancer incidence and mortality, and better dose estimates. Accordingly,
some authors estimated organ and effective dose in reference phantoms, but still there is
a critical need to expand these data to larger groups of non-reference children. As an
initial step to address this issue, in this study organ and effective doses were
calculated in common CT procedures in non-reference pediatric phantoms and were compared
with those of reference phantoms with the similar ages. Thirteen pediatric phantoms, BABY
CHILD, five voxel-based UF pediatric phantoms (B-series) and six phantoms developed at The
Foundation for Research on Information Technologies in Society (IT’IS) were implemented
into MCNP. According to the results, there were no consistent differences between the
doses of organs exposed indirectly and effective doses of these three phantom types, but
it was observed that for organs located in the scan region, there was a relation between
absorbed doses and pediatric age group, as expected. Generally, using the results of this
study one can estimate the absorbed doses more accurately. But it should be noted that
these low expansion data are not comprehensive enough for finding a reasonable
relationship between phantom size and effective dose except in chest-abdomen-pelvis (CAP)
imaging
- …