1,916 research outputs found
Women's entrepreneurship and intimate partner violence: A cluster randomized trial of microenterprise assistance and partner participation in post-conflict Uganda (SSM-D-14-01580R1)
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Intimate partner violence is widespread and represents an obstacle to human freedom and a significant public health concern. Poverty alleviation programs and efforts to economically “empower” women have become popular policy options, but theory and empirical evidence are mixed on the relationship between women's empowerment and the experience of violence. We study the effects of a successful poverty alleviation program on women's empowerment and intimate partner relations and violence from 2009 to 2011. In the first experiment, a cluster-randomized superiority trial, 15 marginalized people (86% women) were identified in each of 120 villages (n = 1800) in Gulu and Kitgum districts in Uganda. Half of villages were randomly assigned via public lottery to immediate treatment: five days of business training, $150, and supervision and advising. We examine intent-to-treat estimates of program impact and heterogeneity in treatment effects by initial quality of partner relations. 16 months after the initial grants, the program doubled business ownership and incomes (p < 0.01); we show that the effect on monthly income, however, is moderated by initial quality of intimate partner relations. We also find small increases in marital control (p < 0.05), self-reported autonomy (p < 0.10), and quality of partner relations (p < 0.01), but essentially no change in intimate partner violence. In a second experiment, we study the impact of a low-cost attempt to include household partners (often husbands) in the process. Participants from the 60 waitlist villages (n = 904) were randomly assigned to participate in the program as individuals or with a household partner. We observe small, non-significant decreases in abuse and marital control and large increases in the quality of relationships (p < 0.05), but no effects on women's attitudes toward gender norms and a non-significant reduction in autonomy. Involving men and changing framing to promote more inclusive programming can improve relationships, but may not change gender attitudes or increase business success. Increasing women's earnings has no effect on intimate partner violence.A Vanguard Charitable Trust and the LOGiCA Trust Fund at the World Bank funded data collection and analysis. This article is the result of independent research and does not necessarily represent the views of the Consumer Financial Protection Bureau or the United States
The returns to microenterprise support among the ultrapoor: A field experiment in postwar Uganda
This is the final version of the article. Available from American Economic Association via the DOI in this record.We show that extremely poor, war-affected women in northern Uganda have high returns to a package of $150 cash, five days of business skills training, and ongoing supervision. Sixteen months after grants, participants doubled their microenterprise ownership and incomes, mainly from petty trading. We also show these ultrapoor have too little social capital, but that group bonds, informal insurance, and cooperative activities could be induced and had positive returns. When the control group received cash and training 20 months later, we varied supervision, which represented half of the program costs. A year later, supervision increased business survival but not consumption. (JEL I38, J16, J23, J24, L26, O15, Z13
Influence of Microstructure on Ultrasonic Velocity in Nimonic Alloy PE16
Superalloys are widely used for many advanced applications. The alloys with optimum properties are obtained by introducing suitable microstructure through thermomechanical treatments. Characterization of microstructure and determination of mechanical properties of these alloys using ultrasonic parameters should help in quality control during heat treatment and identifying changes in microstructure during service. This study is aimed at demonstrating such a possibility in a selected precipitation hardenable nickel base superalloy, Nimonic alloy PE16. As part of this study, the influence of various secondary phases, γ′, MC and M23C6 on ultrasonic velocity is reported. Ultrasonic velocity has been selected as this parameter had been widely used for microstructural characterization and mechanical property determination in various materials [1–6]. γ′ is a coherent and ordered FCC phase having composition Ni3 (Al, Ti). The strengthening is achieved by the presence of γ′ in the microstructure. MC and M23C6 are respectively the Ti rich (Ti, Mo) C and Cr rich (Cr, Fe)23C6 carbides. The carbide phases are introduced to obtain better high temperature creep properties
Deletions of the derivative chromosome 9 occur at the time of the Philadelphia translocation and provide a powerful and independent prognostic indicator in chronic myeloid leukemia
Chronic myeloid leukemia (CML) is characterized by formation of the BCR-ABL fusion gene, usually as a consequence of the Philadelphia (Ph) translocation between chromosomes 9 and 22. Large deletions on the derivative chromosome 9 have recently been reported, but it was unclear whether deletions arose during disease progression or at the time of the Ph translocation. Fluorescence in situ hybridization (FISH) analysis was used to assess the deletion status of 253 patients with CML. The strength of deletion status as a prognostic indicator was then compared to the Sokal and Hasford scoring systems. The frequency of deletions was similar at diagnosis and after disease progression but was significantly increased in patients with variant Ph translocations. In patients with a deletion, all Ph+ metaphases carried the deletion. The median survival of patients with and without deletions was 38 months and 88 months, respectively (P = .0001). By contrast the survival difference between Sokal or Hasford high-risk and non-high-risk patients was of only borderline significance (P = .057 and P = .034). The results indicate that deletions occur at the time of the Ph translocation. An apparently simple reciprocal translocation may therefore result in considerable genetic heterogeneity ab initio, a concept that is likely to apply to other malignancies associated with translocations. Deletion status is also a powerful and independent prognostic factor for patients with CML. The prognostic significance of deletion status should now be studied prospectively and, if confirmed, should be incorporated into management decisions and the analysis of clinical trials. (C) 2001 by The American Society of Hematology
Mineral maturity and crystallinity index are distinct characteristics of bone mineral
The purpose of this study was to test the hypothesis that mineral maturity and crystallinity index are two different characteristics of bone mineral. To this end, Fourier transform infrared microspectroscopy (FTIRM) was used. To test our hypothesis, synthetic apatites and human bone samples were used for the validation of the two parameters using FTIRM. Iliac crest samples from seven human controls and two with skeletal fluorosis were analyzed at the bone structural unit (BSU) level by FTIRM on sections 2–4 lm thick. Mineral maturity and crystallinity index were highly correlated in synthetic apatites but poorly correlated in normal human bone. In skeletal fluorosis, crystallinity index was increased and maturity decreased, supporting the fact of separate measurement of these two parameters. Moreover, results obtained in fluorosis suggested that mineral characteristics can be modified independently of bone remodeling. In conclusion, mineral maturity and crystallinity index are two different parameters measured separately by FTIRM and offering new perspectives to assess bone mineral traits in osteoporosis
The Structure of n-Point One-Loop Open Superstring Amplitudes
In this article we present the worldsheet integrand for one-loop amplitudes
in maximally supersymmetric superstring theory involving any number n of
massless open string states. The polarization dependence is organized into the
same BRST invariant kinematic combinations which also govern the leading string
correction to tree level amplitudes. The dimensions of the bases for both the
kinematics and the associated worldsheet integrals is found to be the unsigned
Stirling number S_3^{n-1} of first kind. We explain why the same combinatorial
structures govern on the one hand finite one-loop amplitudes of equal helicity
states in pure Yang Mills theory and on the other hand the color tensors at
quadratic alpha prime order of the color dressed tree amplitude.Comment: 75 pp, 8 figs, harvmac TeX, v2: published versio
Food-Web Structure of Seagrass Communities across Different Spatial Scales and Human Impacts
Seagrass beds provide important habitat for a wide range of marine species but are threatened by multiple human impacts in coastal waters. Although seagrass communities have been well-studied in the field, a quantification of their food-web structure and functioning, and how these change across space and human impacts has been lacking. Motivated by extensive field surveys and literature information, we analyzed the structural features of food webs associated with Zostera marina across 16 study sites in 3 provinces in Atlantic Canada. Our goals were to (i) quantify differences in food-web structure across local and regional scales and human impacts, (ii) assess the robustness of seagrass webs to simulated species loss, and (iii) compare food-web structure in temperate Atlantic seagrass beds with those of other aquatic ecosystems. We constructed individual food webs for each study site and cumulative webs for each province and the entire region based on presence/absence of species, and calculated 16 structural properties for each web. Our results indicate that food-web structure was similar among low impact sites across regions. With increasing human impacts associated with eutrophication, however, food-web structure show evidence of degradation as indicated by fewer trophic groups, lower maximum trophic level of the highest top predator, fewer trophic links connecting top to basal species, higher fractions of herbivores and intermediate consumers, and higher number of prey per species. These structural changes translate into functional changes with impacted sites being less robust to simulated species loss. Temperate Atlantic seagrass webs are similar to a tropical seagrass web, yet differed from other aquatic webs, suggesting consistent food-web characteristics across seagrass ecosystems in different regions. Our study illustrates that food-web structure and functioning of seagrass habitats change with human impacts and that the spatial scale of food-web analysis is critical for determining results
The Overall Coefficient of the Two-loop Superstring Amplitude Using Pure Spinors
Using the results recently obtained for computing integrals over
(non-minimal) pure spinor superspace, we compute the coefficient of the
massless two-loop four-point amplitude from first principles. Contrasting with
the mathematical difficulties in the RNS formalism where unknown normalizations
of chiral determinant formulae force the two-loop coefficient to be determined
only indirectly through factorization, the computation in the pure spinor
formalism can be smoothly carried out.Comment: 29 pages, harvmac TeX. v2: add reference
Evidence summaries: the evolution of a rapid review approach
<p>Abstract</p> <p>Background</p> <p>Rapid reviews have emerged as a streamlined approach to synthesizing evidence - typically for informing emergent decisions faced by decision makers in health care settings. Although there is growing use of rapid review 'methods', and proliferation of rapid review products, there is a dearth of published literature on rapid review methodology. This paper outlines our experience with rapidly producing, publishing and disseminating evidence summaries in the context of our Knowledge to Action (KTA) research program.</p> <p>Methods</p> <p>The KTA research program is a two-year project designed to develop and assess the impact of a regional knowledge infrastructure that supports evidence-informed decision making by regional managers and stakeholders. As part of this program, we have developed evidence summaries - our form of rapid review - which have come to be a flagship component of this project. Our eight-step approach for producing evidence summaries has been developed iteratively, based on evidence (where available), experience and knowledge user feedback. The aim of our evidence summary approach is to deliver quality evidence that is both timely and user-friendly.</p> <p>Results</p> <p>From November 2009 to March 2011 we have produced 11 evidence summaries on a diverse range of questions identified by our knowledge users. Topic areas have included questions of clinical effectiveness to questions on health systems and/or health services. Knowledge users have reported evidence summaries to be of high value in informing their decisions and initiatives. We continue to experiment with incorporating more of the established methods of systematic reviews, while maintaining our capacity to deliver a final product in a timely manner.</p> <p>Conclusions</p> <p>The evolution of the KTA rapid review evidence summaries has been a positive one. We have developed an approach that appears to be addressing a need by knowledge users for timely, user-friendly, and trustworthy evidence and have transparently reported these methods here for the wider rapid review and scientific community.</p
Chapter 1: Introduction to the Methods Guide for Medical Test Reviews
Evaluation of medical tests presents challenges distinct from those involved in the evaluation of therapies; in particular, the very great importance of context and the dearth of comprehensive RCTs aimed at comparing the clinical outcomes of different tests and test strategies. Available guidance provides some suggestions: 1) Use of the PICOTS typology for clarifying the context relevant to the review, and 2) use of an organizing framework for classifying the types of medical test evaluation studies and their relationship to potential key questions. However, there is a diversity of recommendations for reviewers of medical tests and a proliferation of concepts, terms, and methods. As a contribution to the field, this Methods Guide for Medical Test Reviews seeks to provide practical guidance for achieving the goals of clarity, consistency, tractability, and usefulness
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