552 research outputs found
A conceptual framework for integrated impact assessment of trypanosomiasis interventions
A framework for assessing the integrated impacts of trypanosomiasis interventions that resembles the structure of the DPSIR conceptual model (see EEA 2000) is developed in this study. This framework provides a way to make evident the pressures on the involved systems, define the target groups and levels of analysis, establish cause and effect relationships, organise information about the state of the systems, select appropriate methodologies for impact assessment, identify indicators, scaling up and scaling out the results, promote dynamic learning processes and evidence the potential responses of the society. The structure of this paper is as follows: The main concepts of impact assessment are initially introduced; and an integrated vision of the interaction between environmental, economic and social systems is presented. Then a set of key questions to be considered in the design of impact assessment studies are reviewed. Later, the basic elements of the impact analysis are shown in a logical sequence to present the conceptual framework for integrated impact assessment of trypanosomiasis interventions. Finally, the paper summarises the available methodologies for impact assessment on the different systems and provide some conclusions
Guidelines for assessing environmental and socio-economic impacts of tsetse and trypanosomiasis interventions
This report provides guidelines on methods and tools for conducting impact assessments of T&T (tsetse and trypanosomiasis) interventions on the environmental, social and economic systems and on approaches for the integrated impact assessment of the interventions. The purpose of these guidelines is help donors, development agencies, project implementers and other T&T eradication stakeholders to identify adequate options for assessing the impacts of T&T interventions based on their target level of analysis, available resources and constraints. These guidelines are therefore aimed at helping PATTEC (African Union 's Pan African Tsetse and Trypanosomiasis Eradication Campaign) project managers and their experts target their priorities in environmental and socio-economic impact assessments. This will allow them to address pertinent issues adequately for the benefit of all stakeholders and allocate their resources rationally
Morse theory of the moment map for representations of quivers
The results of this paper concern the Morse theory of the norm-square of the
moment map on the space of representations of a quiver. We show that the
gradient flow of this function converges, and that the Morse stratification
induced by the gradient flow co-incides with the Harder-Narasimhan
stratification from algebraic geometry. Moreover, the limit of the gradient
flow is isomorphic to the graded object of the
Harder-Narasimhan-Jordan-H\"older filtration associated to the initial
conditions for the flow. With a view towards applications to Nakajima quiver
varieties we construct explicit local co-ordinates around the Morse strata and
(under a technical hypothesis on the stability parameter) describe the negative
normal space to the critical sets. Finally, we observe that the usual Kirwan
surjectivity theorems in rational cohomology and integral K-theory carry over
to this non-compact setting, and that these theorems generalize to certain
equivariant contexts.Comment: 48 pages, small revisions from previous version based on referee's
comments. To appear in Geometriae Dedicat
Can we avoid high coupling?
It is considered good software design practice to organize source code into modules and to favour within-module connections (cohesion) over between-module connections (coupling), leading to the oft-repeated maxim "low coupling/high cohesion". Prior research into network theory and its application to software systems has found evidence that many important properties in real software systems exhibit approximately scale-free structure, including coupling; researchers have claimed that such scale-free structures are ubiquitous. This implies that high coupling must be unavoidable, statistically speaking, apparently contradicting standard ideas about software structure. We present a model that leads to the simple predictions that approximately scale-free structures ought to arise both for between-module connectivity and overall connectivity, and not as the result of poor design or optimization shortcuts. These predictions are borne out by our large-scale empirical study. Hence we conclude that high coupling is not avoidable--and that this is in fact quite reasonable
Variational Principle underlying Scale Invariant Social Systems
MaxEnt's variational principle, in conjunction with Shannon's logarithmic
information measure, yields only exponential functional forms in
straightforward fashion. In this communication we show how to overcome this
limitation via the incorporation, into the variational process, of suitable
dynamical information. As a consequence, we are able to formulate a somewhat
generalized Shannonian Maximum Entropy approach which provides a unifying
"thermodynamic-like" explanation for the scale-invariant phenomena observed in
social contexts, as city-population distributions. We confirm the MaxEnt
predictions by means of numerical experiments with random walkers, and compare
them with some empirical data
Ginzburg-Landau vortex dynamics with pinning and strong applied currents
We study a mixed heat and Schr\"odinger Ginzburg-Landau evolution equation on
a bounded two-dimensional domain with an electric current applied on the
boundary and a pinning potential term. This is meant to model a superconductor
subjected to an applied electric current and electromagnetic field and
containing impurities. Such a current is expected to set the vortices in
motion, while the pinning term drives them toward minima of the pinning
potential and "pins" them there. We derive the limiting dynamics of a finite
number of vortices in the limit of a large Ginzburg-Landau parameter, or \ep
\to 0, when the intensity of the electric current and applied magnetic field
on the boundary scale like \lep. We show that the limiting velocity of the
vortices is the sum of a Lorentz force, due to the current, and a pinning
force. We state an analogous result for a model Ginzburg-Landau equation
without magnetic field but with forcing terms. Our proof provides a unified
approach to various proofs of dynamics of Ginzburg-Landau vortices.Comment: 48 pages; v2: minor errors and typos correcte
An updated analysis of NN elastic scattering data to 1.6 GeV
An energy-dependent and set of single-energy partial-wave analyses of
elastic scattering data have been completed. The fit to 1.6~GeV has been
supplemented with a low-energy analysis to 400 MeV. Using the low-energy fit,
we study the sensitivity of our analysis to the choice of coupling
constant. We also comment on the possibility of fitting data alone. These
results are compared with those found in the recent Nijmegen analyses. (Figures
may be obtained from the authors upon request.)Comment: 17 pages of text, VPI-CAPS-7/
Musculoskeletal injury history is associated with lower physical and mental health in a historical cohort of former national football league players
Context: Little research has examined health-related quality of life in former National Football League (NFL) players. Objective: Examine the association of musculoskeletal injury history and current self-reported physical and mental health in former NFL players. Setting: Cross-sectional questionnaire. Patients or Other Participants: Historical cohort of 2,103 former NFL players that played at least one season between 1940 and 2001. Intervention: Players were grouped by self-reported professional career musculoskeletal injury history and whether injuries affected current health: (1) no musculoskeletal injury history; (2) musculoskeletal injury history, currently affected by injuries; and (3) musculoskeletal injury history, not currently affected by injuries. Main Outcome Measure: The Short Form 36 Measurement Model for Functional Assessment of Health and Well-Being (SF-36) yielded physical and mental health composite scores (PCS and MCS, respectively); higher scores indicated better health. Multivariable linear regression computed mean differences (MD) among injury groups. Covariates included demographics, playing history characteristics, surgical intervention for musculoskeletal injuries, and whether injury resulted in premature end to career. MD with 95% CI excluding 0.00 were deemed significant. Results: Overall, 90.3% reported at least one musculoskeletal injury during their professional football careers, of which 74.8% reported being affected by their injuries at time of survey completion. Adjusting for covariates, mean PCS in the âinjury and affectedâ group was lower than the âno injuryâ (MD = â3.2; 95% CI: â4.8, â1.7) and âinjury and not affectedâ groups (MD = â4.3; 95% CI: â5.4, â3.3); mean MCS did not differ. Conclusion: Many players reported musculoskeletal injuries, highlighting the need for developing and evaluating injury management interventions
Geriatric Screening, Triage Urgency, and 30-Day Mortality in Older Emergency Department Patients
BACKGROUND: Urgency triage in the emergency department (ED) is important for early identification of potentially lethal conditions and extensive resource utilization. However, in older patients, urgency triage systems could be improved by taking geriatric vulnerability into account. We investigated the association of geriatric vulnerability screening in addition to triage urgency levels with 30-day mortality in older ED patients. DESIGN: Secondary analysis of the observational multicenter Acutely Presenting Older Patient (APOP) study. SETTING: EDs within four Dutch hospitals. PARTICIPANTS: Consecutive patients, aged 70 years or older, who were prospectively included. MEASUREMENTS: Patients were triaged using the Manchester Triage System (MTS). In addition, the APOP screener was used as a geriatric screening tool. The primary outcome was 30-day mortality. Comparison was made between mortality within the geriatric high- and low-risk screened patients in every urgency triage category. We calculated the difference in explained variance of mortality by adding the geriatric screener (APOP) to triage urgency (MTS) by calculating Nagelkerke R2. RESULTS: We included 2,608 patients with a median age of 79 (interquartile range = 74-84) years, of whom 521 (20.0%) patients were categorized as high risk accor
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