12,805 research outputs found
FARM-LEVEL RESPONSE TO AGRICULTURAL EFFLUENT CONTROL STRATEGIES: THE CASE OF THE WILLAMETTE VALLEY
This article examines economic incentives and other mechanisms to offset non-point source pollution from agriculture. A biophysical simulator to estimate technical relationships is linked to linear programming models for representative farms in the Willamette Valley of Oregon. The models are then optimized for profit maximization under alternative non-point pollution control policies. The results indicate that site-specific resource conditions and production possibilities greatly influence policy effectiveness and the cost of achieving pollution abatement. Nevertheless, some abatement is possible on all farms for relatively little cost.Environmental Economics and Policy,
Quantum phase transition in spin glasses with multi-spin interactions
We examine the phase diagram of the -interaction spin glass model in a
transverse field. We consider a spherical version of the model and compare with
results obtained in the Ising case. The analysis of the spherical model, with
and without quantization, reveals a phase diagram very similar to that obtained
in the Ising case. In particular, using the static approximation, reentrance is
observed at low temperatures in both the quantum spherical and Ising models.
This is an artifact of the approximation and disappears when the imaginary time
dependence of the order parameter is taken into account. The resulting phase
diagram is checked by accurate numerical investigation of the phase boundaries.Comment: 20 Pages including 10 figures, Revte
Lack of Transit Timing Variations of OGLE-TR-111b: A re-analysis with six new epochs
We present six new transits of the exoplanet OGLE-TR-111b observed with the
Magellan Telescopes in Chile between April 2008 and March 2009. We combine
these new transits with five previously published transit epochs for this
planet between 2005 and 2006 to extend the analysis of transit timing
variations reported for this system. We derive a new planetary radius value of
1.019 +/- 0.026 R_J, which is intermediate to the previously reported radii of
1.067 +/- 0.054 R_J (Winn et al. 2007) and 0.922 +/- 0.057 R_J (Diaz et al.
2008). We also examine the transit timing variation and duration change claims
of Diaz et al. (2008). Our analysis of all eleven transit epochs does not
reveal any points with deviations larger than 2 sigma, and most points are well
within 1 sigma. Although the transit duration nominally decreases over the four
year span of the data, systematic errors in the photometry can account for this
result. Therefore, there is no compelling evidence for either a timing or a
duration variation in this system. Numerical integrations place an upper limit
of about 1 M_E on the mass of a potential second planet in a 2:1 mean-motion
resonance with OGLE-TR-111b.Comment: 28 pages, 7 tables, 6 figures. Accepted by Ap
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Informing the development of services supporting self-care for long term mental health conditions: A mixed method study of community based mental health initiatives in England
Background
Supporting self-care is being explored across health care systems internationally as an approach to improving care for long term conditions in the context of ageing populations and economic constraint. UK health policy advocates a range of approaches to supporting self-care, including the application of generic self-management type programmes across conditions. Within mental health, the scope of self-care remains poorly conceptualised and the existing evidence base for supporting self-care is correspondingly disparate. This paper aims to inform the development of support for self-care in mental health by considering how generic self-care policy guidance is implemented in the context of services supporting people with severe, long term mental health problems.
Methods
A mixed method study was undertaken comprising standardised psychosocial measures, questionnaires about health service use and qualitative interviews with 120 new referrals to three contrasting community based initiatives supporting self-care for severe, long term mental health problems, repeated nine months later. A framework approach was taken to qualitative analysis, an exploratory statistical analysis sought to identify possible associations between a range of independent variables and self-care outcomes, and a narrative synthesis brought these analyses together.
Results
Participants reported improvement in self-care outcomes (e.g. greater empowerment; less use of Accident and Emergency services). These changes were not associated with level of engagement with self-care support. Level of engagement was associated with positive collaboration with support staff. Qualitative data described the value of different models of supporting self-care and considered challenges. Synthesis of analyses suggested that timing support for self-care, giving service users control over when and how they accessed support, quality of service user-staff relationships and decision making around medication are important issues in supporting self-care in mental health.
Conclusions
Service delivery components – e.g. peer support groups, personal planning – advocated in generic self-care policy have value when implemented in a mental health context. Support for self-care in mental health should focus on core, mental health specific qualities; issues of control, enabling staff-service user relationships and shared decision making. The broad empirical basis of our research indicates the wider relevance of our findings across mental health settings
Training Extension Professionals from Developing Countries Through Educational Workshops Conducted in the United States
Many opportunities exist for conducting stateside professional improvement workshops to train Extension professionals from developing countries. To conduct a successful workshop it is important to understand the needs of the partner country and identify participants who can use their workshop training to address those needs. An effective workshop will have high-quality field trips, practical classroom instruction, and opportunities for cultural exchange. Pre-workshop planning and close attention to logistical issues are essential to the success of the workshop. Good evaluation of the workshop is important to measure the impacts of the workshop and provide input for improving future workshops
Mechanisms of Mental-Health Disparities Among Minoritized Groups: How Well Are the Top Journals in Clinical Psychology Representing This Work?
It has been known for decades that mental-health disparities exist among minoritized groups, including race, ethnicity, sexual identities, gender identity and expression, ability, and others. Theories and frameworks that incorporate stressors unique to the experiences of minoritized groups, such as the biopsychosocial model of racism and minority-stress model, offer testable mechanisms that may help explain, in part, mental-health disparities. However, research addressing mechanisms of these disparities is still scarce and is not well represented in top clinical psychology journals. In this review, we critically examine the extent to which top-tier clinical psychology journals publish work examining mechanisms of mental-health disparities among minoritized populations. We found that very few studies that address mechanisms of mental-health disparities have been published in top clinical psychology journals. We examine potential reasons for this and discuss recommendations for future research
Nucleon Charge Symmetry Breaking and Parity Violating Electron-Proton Scattering
The consequences of the charge symmetry breaking effects of the mass
difference between the up and down quarks and electromagnetic effects for
searches for strangeness form factors in parity violating electron scattering
from the proton are investigated. The formalism necessary to identify and
compute the relevant observables is developed by separating the Hamiltonian
into charge symmetry conserving and breaking terms. Using a set of SU(6)
non-relativistic quark models, the effects of the charge symmetry breaking
Hamiltonian are considered for experimentally relevant alues of the momentum
transfer and found to be less than about 1 percent. The charge symmetry
breaking corrections to the Bjorken sum rule are also studied and shown to
vanish in first-order perturbation theory.Comment: 35 pages, 9 figure
Applicability of Monte Carlo Glauber models to relativistic heavy ion collision data
The accuracy of Monte Carlo Glauber model descriptions of minimum-bias
multiplicity frequency distributions is evaluated using data from the
Relativistic Heavy Ion Collider (RHIC) within the context of a sensitive,
power-law representation introduced previously by Trainor and Prindle (TP).
Uncertainties in the Glauber model input and in the mid-rapidity multiplicity
frequency distribution data are reviewed and estimated using the TP centrality
methodology. The resulting errors in model-dependent geometrical quantities
used to characterize heavy ion collisions ({\em i.e.} impact parameter, number
of nucleon participants , number of binary interactions ,
and average number of binary collisions per incident participant nucleon )
are presented for minimum-bias Au-Au collisions at = 20, 62,
130 and 200 GeV and Cu-Cu collisions at = 62 and 200 GeV.
Considerable improvement in the accuracy of collision geometry quantities is
obtained compared to previous Monte Carlo Glauber model studies, confirming the
TP conclusions. The present analysis provides a comprehensive list of the
sources of uncertainty and the resulting errors in the above geometrical
collision quantities as functions of centrality. The capability of energy
deposition data from trigger detectors to enable further improvements in the
accuracy of collision geometry quantities is also discussed.Comment: 27 pages, 4 figures, 11 table
Cross Section Measurements Using the Zero Degree Detector
The Zero Degree Detector (ZDD) is an instrument that has been used in accelerator exposures to measure the angular dependence of particles produced in heavy ion fragmentation experiments. The ZDD uses two identical layers of pixelated silicon detectors that make coincident measurements over the active area of the instrument. The angular distribution of secondary particle produced in nuclear interactions for several heavy ions: and target materials will be presented along with performance characteristic of the instrument
Blackbody-radiation-assisted molecular laser cooling
The translational motion of molecular ions can be effectively cooled
sympathetically to temperatures below 100 mK in ion traps through Coulomb
interactions with laser-cooled atomic ions. The distribution of internal
rovibrational states, however, gets in thermal equilibrium with the typically
much higher temperature of the environment within tens of seconds. We consider
a concept for rotational cooling of such internally hot, but translationally
cold heteronuclear diatomic molecular ions. The scheme relies on a combination
of optical pumping from a few specific rotational levels into a ``dark state''
with redistribution of rotational populations mediated by blackbody radiation.Comment: 4 pages, 5 figure
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