3,662 research outputs found
Impact Evaluation in Practice
The book is a comprehensive and accessible introduction to impact evaluation for policy makers and development practitioners. First published in 2011, it has been used widely across the development and academic communities. The book incorporates real-world examples to present practical guidelines for designing and implementing impact evaluations. Readers will gain an understanding of impact evaluations and the best ways to use them to design evidence-based policies and programs. The updated version covers the newest techniques for evaluating programs and includes state-of-the-art implementation advice, as well as an expanded set of examples and case studies that draw on recent development challenges. It also includes new material on research ethics and partnerships to conduct impact evaluation. The handbook is divided into four sections: Part One discusses what to evaluate and why; Part Two presents the main impact evaluation methods; Part Three addresses how to manage impact evaluations; Part Four reviews impact evaluation sampling and data collection. Case studies illustrate different applications of impact evaluations. The book links to complementary instructional material available online, including an applied case as well as questions and answers. The updated second edition will be a valuable resource for the international development community, universities, and policy makers looking to build better evidence around what works in development
Inter‑individual consistency in habitat selection patterns and spatial range constraints of female little bustards during the non‑breeding season
Background: Identifying the factors that affect ranging behavior of animals is a central issue to ecology and an essential tool for designing effective conservation policies. This knowledge provides the information needed to pre- dict the consequences of land-use change on species habitat use, especially in areas subject to major habitat trans- formations, such as agricultural landscapes. We evaluate inter-individual variation relative to environmental predictors and spatial constraints in limiting ranging behavior of female little bustards (Tetrax tetrax) in the non-breeding season. Our analyses were based on 11 females tracked with GPS during 5 years in northeastern Spain. We conducted devi- ance partitioning analyses based on different sets of generalized linear mixed models constructed with environmen- tal variables and spatial filters obtained by eigenvector mapping, while controlling for temporal and inter-individual variation. Results: The occurrence probability of female little bustards in response to environmental variables and spatial filters within the non-breeding range exhibited inter-individual consistency. Pure spatial factors and joint spatial-habitat factors explained most of the variance in the models. Spatial predictors representing aggregation patterns at ~ 18 km and 3-5 km respectively had a high importance in female occurrence. However, pure habitat effects were also identi- fied. Terrain slope, alfalfa, corn stubble and irrigated cereal stubble availability were the variables that most contrib- uted to environmental models. Overall, models revealed a non-linear negative effect of slope and positive effects of intermediate values of alfalfa and corn stubble availability. High levels of cereal stubble in irrigated land and roads had also a positive effect on occurrence at the population level. Conclusions: Our results provide evidence that female little bustard ranging behavior was spatially constrained beyond environmental variables during the non-breeding season. This pattern may result from different not mutually exclusive processes, such as cost-benefit balances of animal movement, configurational heterogeneity of environ- ment or from high site fidelity and conspecific attraction. Measures aimed at keeping alfalfa availability and habitat heterogeneity in open landscapes and flat terrains, in safe places close to breeding grounds, could contribute to protect little bustard populations during the non-breeding season
Diarréia associada a astrovírus em crianças de ambulatório em Hospital Público de Córdoba, Argentina
Human astroviruses have been increasingly identified as important agents of diarrheal disease in children. However, the disease burden of astrovirus infection is still incompletely assessed. This paper reports results on the epidemiological and clinical characteristics of astrovirus-associated diarrhea, as well as the impact of astrovirus infection on the ambulatory setting at a Public Hospital in Córdoba city, Argentina. From February 2001 through January 2002, 97 randomly selected outpatient visits for diarrhea among children ; 0.05). According to our estimation about one out of seventy-four children in this cohort would be assisted annually for an astroviral-diarrheal episode in the Public Hospital and one out of eight diarrheal cases could be attributed to astrovirus infection. Astrovirus is a common symptomatic infection in pediatric outpatient visits in the public hospital in the study area, contributing 12.37% of the overall morbidity from diarrhea.Os astrovírus humanos têm sido identificados como importantes agentes de diarréias em crianças embora o impacto da sua infecção não tenha sido esclarecido. Este estudo não só mostra os resultados das características epidemiológicas e clínicas, mas também o impacto da infecção por astrovírus em pacientes ambulatoriais de um Hospital Público da cidade de Córdoba na Argentina. Escolheram-se randomicamente 97 pacientes ambulatoriais com menos de 36 meses, entre fevereiro de 2001 e janeiro de 2002, que consultaram por diarréia. Pesquisou-se antígeno de astrovírus por ensaio imuno-enzimático em uma única amostra de fezes por paciente estudado. Determinou-se a presença de astrovírus em 12,37% dos casos de diarréia. Todos os casos positivos foram em crianças de 4 a 18 meses, mas o índice mais elevado se apresentou em crianças de 4 a 6 meses (23,80%). Os sintomas de diarréia associada a astrovírus foram febre 41,66%; vômitos 25,00% e desidratação 8,33%; ou seja, 16,66% dos pacientes precisaram hospitalização. A presença de astrovírus foi anual sem se observar comportamento sazonal, semestre frio 15,21% versus semestre quente 9,80% p >; 0,05. Em nossa pesquisa, uma de cada 74 crianças seria atendida anualmente por apresentar um episódio de diarréia associada a astrovírus no hospital público e um de cada 8 casos de diarréia poderia atribuir-se à infecção por astrovírus. Astrovírus é uma infecção sintomática em pacientes pediátricos ambulatoriais, representando 12,37% da morbidade por diarréia
Final Report for the April 2009 Gulf of Alaska Line-Transect Survey (Goals) in the Navy Training Exercise Area
Little is known about the occurrence of cetaceans found in offshore waters in the Gulf of Alaska; however, whaling records and a few recent surveys have shown this area to be important habitat. The United States Navy maintains a maritime training area in the central Gulf of Alaska, east of Kodiak Island, and has requested additional information on marine mammal presence and use of this area. To determine the occurrence and distribution of marine mammals in and around the Navy training area, a line-transect visual and acoustic survey was conducted 10-20 April 2009 from the NOAA R/V Oscar Dyson. The primary survey area encompassed nearshore, shelf and offshore pelagic waters of the central Gulf of Alaska. Survey lines were designed to provide equal coverage of the nearshore and offshore habitat.Funded by Naval Postgraduate School.N00244-09-P-096
Epidemiologia da gastrenterite viral aguda em crianças hospitalizadas na cidade de Córdoba, Argentina: uma percepção ao impacto da doença
Information concerning the disease burden of viral gastroenteritis has important implications for the use and monitoring the impact of public health policies. The present study, carried out in Córdoba city, Argentina, documents the epidemiology of severe viral diarrhea as well as the burden of viral gastrointestinal disease in the hospital children admission. A total of 133 stools were collected from hospitalized children (Town Childhood Hospital) suffering from acute diarrhea and studied for the presence of Group A rotavirus, astrovirus and adenovirus 40/41 by enzyme-immuno assay, between November 1997 and October 1998. Enteric viruses accounted for 42.1% of the total diarrheal cases analyzed. Group A rotaviruses, astroviruses, adenoviruses 40/41 and mixed infections were found in 35.3, 4.5, 1.5, and 0.8% studied specimens respectively. We estimated that 1 in 27 children in the 0-35 month-old cohort/range would be annually hospitalized for a viral gastroenteritis illness. The major impact on viral diarrhea lies on rotaviral infection, accouting for 84.0% of the viral diarrheal cases analyzed and for approximately one third of severe diarrheas requiring hospital admission in Córdoba City, Argentina.Dados a respeito do impacto das gastrenterites virais têm implicações importantes para o monitoraramento do impacto das políticas de saúde pública. O presente estudo, feito na cidade de Córdoba, Argentina, documenta a epidemiologia da diarréia viral severa como também o impacto que a mesma representa na admissão hospitalar de crianças. Pesquisou-se a presença de Rotavírus grupo A, Astrovírus e Adenovírus 40/41 por ensaio imuno-enzimático em 133 amostras de fezes obtidas durante o período de novembro de 1997 a outubro de 1998, de crianças hospitalizadas por diarréia aguda. Os virus entéricos constituíram 42,1% do total de casos de diarréia analisados. Encontraram-se Rotavírus Grupo A, Astrovírus, Adenovírus 40/41 e infecções mistas em 35,3; 4,5; 1,5 e 0,8% das amostrras estudadas, respectivamente. Observamos que uma de cada 27 crianças entre 0-35 meses de idade seria hospitalizada por ano devido a uma gastrenterite viral. O principal impacto da diarréia viral é representado pela infecção por Rotavírus, correspondendo a 84,0% dos casos analisados e cerca de um terço das diarréias graves que precisam hospitalização em Córdoba, Argentina
Clasificador difuso para diagnóstico de enfermedades
En este artículo se presenta la aplicación de un nuevo método de identificación difusa para resolver problemas de clasificación. El modelo o clasificador difuso obtenido después del proceso de entrenamiento, contiene conjuntos triangulares con solapamiento de 0.5 para el antecedente y conjuntos tipo singleton para el consecuente. En la evaluación de las reglas se emplea un operador promedio en vez de una T-norma. Los consecuentes son ajustados empleando mínimos cuadrados recursivos. El método propuesto consigue una mayor precisión que la alcanzada con los métodos actuales existentes, empleando un número reducido de reglas y parámetros, sin sacrificar la interpretabilidad del modelo difuso. El enfoque propuesto es aplicado a dos problemas clásicos de clasificación: el Pima Indian Diabetic y el Dermatology Problem, para mostrar el desempeño del método propuesto y comparar los resultados con los alcanzados por otros investigadores.This paper presents the application of a new fuzzy identification method to solve classification problems. The model or fuzzy classifier, obtained after training process, contains triangular sets with 0.5 overlapping to the antecedent and singleton sets for the consequent. In the evaluation of the rules is used an average operator instead of a T-norm. The consequent are adjusted using recursive least squares. The proposed method achieves higher accuracy than others methods, using a small number of rules and parameters, without sacrificing the interpretability of the fuzzy model. The proposed approach is applied in two classic classification problems: Pima Indian Diabetic and Dermatology Problem, to show the performance of the proposed method and compare the results with other researchers
Charge-Carrier Dynamics in 2D Hybrid Metal–Halide Perovskites
Hybrid metal–halide perovskites are promising new materials for use in solar cells; however, their chemical stability in the presence of moisture remains a significant drawback. Quasi two-dimensional (2D) perovskites that incorporate hydrophobic organic interlayers offer improved resistance to degradation by moisture, currently still at the cost of overall cell efficiency. To elucidate the factors affecting the optoelectronic properties of these materials, we have investigated the charge transport properties and crystallographic orientation of mixed methylammonium (MA)–phenylethylammonium (PEA) lead iodide thin films as a function of the MA-to-PEA ratio and, thus, the thickness of the “encapsulated” MA lead–halide layers. We find that monomolecular charge-carrier recombination rates first decrease with increasing PEA fraction, most likely as a result of trap passivation, but then increase significantly as excitonic effects begin to dominate for thin confined layers. Bimolecular and Auger recombination rate constants are found to be sensitive to changes in electronic confinement, which alters the density of states for electronic transitions. We demonstrate that effective charge-carrier mobilities remain remarkably high (near 10 cm2V−1s−1) for intermediate PEA content and are enhanced for preferential orientation of the conducting lead iodide layers along the probing electric field. The trade-off between trap reduction, electronic confinement, and layer orientation leads to calculated charge-carrier diffusion lengths reaching a maximum of 2.5 μm for intermediate PEA content (50%)
Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases
Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests
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Design of the Subpopulations and Intermediate Outcome Measures in COPD (SPIROMICS) AIR Study.
IntroductionPopulation-based epidemiological evidence suggests that exposure to ambient air pollutants increases hospitalisations and mortality from chronic obstructive pulmonary disease (COPD), but less is known about the impact of exposure to air pollutants on patient-reported outcomes, morbidity and progression of COPD.Methods and analysisThe Subpopulations and Intermediate Outcome Measures in COPD (SPIROMICS) Air Pollution Study (SPIROMICS AIR) was initiated in 2013 to investigate the relation between individual-level estimates of short-term and long-term air pollution exposures, day-to-day symptom variability and disease progression in individuals with COPD. SPIROMICS AIR builds on a multicentre study of smokers with COPD, supplementing it with state-of-the-art air pollution exposure assessments of fine particulate matter, oxides of nitrogen, ozone, sulfur dioxide and black carbon. In the parent study, approximately 3000 smokers with and without airflow obstruction are being followed for up to 3 years for the identification of intermediate biomarkers which predict disease progression. Subcohorts undergo daily symptom monitoring using comprehensive daily diaries. The air monitoring and modelling methods employed in SPIROMICS AIR will provide estimates of individual exposure that incorporate residence-specific infiltration characteristics and participant-specific time-activity patterns. The overarching study aim is to understand the health effects of short-term and long-term exposures to air pollution on COPD morbidity, including exacerbation risk, patient-reported outcomes and disease progression.Ethics and disseminationThe institutional review boards of all the participating institutions approved the study protocols. The results of the trial will be presented at national and international meetings and published in peer-reviewed journals
An integrative approach unveils FOSL1 as an oncogene vulnerability in KRAS-driven lung and pancreatic cancer
KRAS mutated tumours represent a large fraction of human cancers, but the vast majority remains refractory to current clinical therapies. Thus, a deeper understanding of the molecular mechanisms triggered by KRAS oncogene may yield alternative therapeutic strategies. Here we report the identification of a common transcriptional signature across mutant KRAS cancers of distinct tissue origin that includes the transcription factor FOSL1. High FOSL1 expression identifies mutant KRAS lung and pancreatic cancer patients with the worst survival outcome. Furthermore, FOSL1 genetic inhibition is detrimental to both KRAS-driven tumour types. Mechanistically, FOSL1 links the KRAS oncogene to components of the mitotic machinery, a pathway previously postulated to function orthogonally to oncogenic KRAS. FOSL1 targets include AURKA, whose inhibition impairs viability of mutant KRAS cells. Lastly, combination of AURKA and MEK inhibitors induces a deleterious effect on mutant KRAS cells. Our findings unveil KRAS downstream effectors that provide opportunities to treat KRAS-driven cancers
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