293 research outputs found

    Lossless State Detection of Single Neutral Atoms

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    We introduce lossless state detection of trapped neutral atoms based on cavity-enhanced fluorescence. In an experiment with a single 87-Rb atom, a hyperfine-state-detection fidelity of 99.4% is achieved in 85 microseconds. The quantum bit is interrogated many hundreds of times without loss of the atom while a result is obtained in every readout attempt. The fidelity proves robust against atomic frequency shifts induced by the trapping potential. Our scheme does not require strong coupling between the atom and cavity and can be generalized to other systems with an optically accessible quantum bit.Comment: 4 pages, 4 figure

    Identificación de unidades de tipificación discreta (DTU) de Trypanosoma cruzi mediante la implementación de un ensayo de genotipado de fusión de alta resolución (HRM)

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    Background Chagas disease, caused by Trypanosoma cruzi, is a geographically widespread anthropozoonosis that is considered a major public health problem in Latin America. Because this parasite presents high genetic variability, a nomenclature has been adopted to classify the parasite into six discrete typing units (DTUs): TcI, TcII, TcIII, TcIV, TcV, and TcVI, which present different eco-epidemiological, clinical, and geographic associations. Currently, the available genotyping methods present a series of drawbacks that implies the need for developing new methods for characterizing T. cruzi DTU’s. The aim of this work was to genotype reference populations from T. cruzi by means of a High-Resolution Melting (HRM) genotyping assay. To genotype the DTUs of 38 strains and 14 reference clones of T. cruzi from diverse sources, real-time PCR (qPCR) was coupled to high-resolution melting (HRM) based on the amplification of two molecular markers—the divergent domain of the 24 s? rRNA gene and the intergenic region of the mini-exon gene. Findings Amplification of the mini-exon gene allowed the genotyping of three distinct groups: TcI, TcII- TcIV- TcV, and TcIII-TcVI, while amplification of the 24s? gene generated non-overlapping melting temperature ranges for each DTU that were used to identify the groups in the six existing DTUs of Trypanosoma cruzi. Conclusions The proposed genotyping assay allowed discrimination of the six genetic groups by obtaining specific melting curves for each DTU. The application of this technique is proposed because of its specificity, sensitivity, high performance, and low cost compared with other previously described characterization methods

    Study of Clogging by Suspended Clay Particles in Surface Spreading Operations for Artificial Groundwater Recharge

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    Gender Inequalities and Demographic Behavior: Egypt

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    This is one of three reports on the relationship between gender equity, family structure and dynamics, and the achievement of reproductive choice prepared by the Population Council for the 1994 International Year of the Family and the 1994 International Conference on Population and Development. These reports provide critical reviews of the relationship between gender inequality and demographic behavior in three demographically significant, culturally distinct parts of the developing world: Egypt, India, and Ghana and Kenya. Their purpose is to help governments and international agencies design and implement policies that are affirmative of women, sensitive to the family\u27s central role in resource allocation and distribution, and effective in achieving broad-based population and development goals. The objectives of this report are to examine the legal, social, and policy context in which gender relations operate in Egypt and to better understand the links between gender dynamics and reproductive behavior

    Distribución actual e importancia epidemiológica de las especies de triatominos (Reduviidae: Triatominae) en Colombia

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    We present the geographical distribution and epidemiological importance for Chagas' disease transmission of 23 triatomine species in Colombia. based on bibliographical reports available in the country and on reference collections housed in the Entomology Laboratory at the lnstituto Nacional de Salud and the Tropical Microbiology and Parasitology Research Center at Universidad de los Andes. We also discuss the ecological conditions under wich triatomines in countries bordering Colombia have been reported. airned at establishing the possible presence of species that have not been reported yet in our country. We, therefore, reportpossible presence in Colombia of species with wild habitats such as Alberprosenia malheiroi, Belminus lapofiei, and Cavernicola lenti, all of them located in the Amaron region; Triatoma nigromaculata. which shows intradomiciliary habits, in the Eastern mountain range; Panstrongylus chinai, probably located in wild habitats and also in settlers' dwellings in the Amazon region dueto its attraction to light, and Alberprosenia goyovargasi, located in wild habitats in our border with Venezuela. The importance of national surveillance programs is highlighted as an aid strategy for the study of triatomine species in Colombia.Se presenta la distribución geográfica y la importancia epidemiológica en la transmisión de la enfermedad de Chagas de las 23 especies de triatominos presentes en Colombia, tomando como base los registros bibliográficos existentes en el pais y las colecciones de referencia del Laboratorio de Entomologia del Instituto Nacional de Salud y del Centro de Investigaciones en Microbiologia y Parasitologia Tropical de la Universidad de los Andes; además, se realiza un análisis de las condiciones ecológicas en las cuales han sido registrados triatominos en los paises con fronteras con Colombia para poder establecer la presencia de posibles especies que aún no se han registrado en nuestro pais. De esta manera. existe la posibilidad de tener en Colombia especies con hábitos silvestres como: Alberprosenia malheiroi. Belminus laportei y Cavernicola lenti, preentes todas ellas en los departamentos amazónicos; Triatoma nigromaculata en la Cordillera Oriental y con hábitos intradomiciliarios; Panstrongylus chinai con posibilidad de encontrarse en hábitats selváticos o en las viviendas de los colonos de la Amazonia debido a su atracción por la luz y Alberprosenia goyovargasien hábitats silvestres de la frontera con Venezuela. Se resalta la importancia de la vigilancia entomológica a nivel nacional como estrategia para reforzar los estudios de triatominos silvestres en Colombia

    Feasibility, drug safety, and effectiveness of etiological treatment programs for Chagas disease in Honduras, Guatemala, and Bolivia: 10-year experience of Médecins Sans Frontières

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    BACKGROUND: Chagas disease (American trypanosomiasis) is a zoonotic or anthropozoonotic disease caused by the parasite Trypanosoma cruzi. Predominantly affecting populations in poor areas of Latin America, medical care for this neglected disease is often lacking. Médecins Sans Frontières/Doctors Without Borders (MSF) has provided diagnostic and treatment services for Chagas disease since 1999. This report describes 10 years of field experience in four MSF programs in Honduras, Guatemala, and Bolivia, focusing on feasibility protocols, safety of drug therapy, and treatment effectiveness. METHODOLOGY: From 1999 to 2008, MSF provided free diagnosis, etiological treatment, and follow-up care for patients <18 years of age seropositive for T. cruzi in Yoro, Honduras (1999-2002); Olopa, Guatemala (2003-2006); Entre Ríos, Bolivia (2002-2006); and Sucre, Bolivia (2005-2008). Essential program components guaranteeing feasibility of implementation were information, education, and communication (IEC) at the community and family level; vector control; health staff training; screening and diagnosis; treatment and compliance, including family-based strategies for early detection of adverse events; and logistics. Chagas disease diagnosis was confirmed by testing blood samples using two different diagnostic tests. T. cruzi-positive patients were treated with benznidazole as first-line treatment, with appropriate counseling, consent, and active participation from parents or guardians for daily administration of the drug, early detection of adverse events, and treatment withdrawal, when necessary. Weekly follow-up was conducted, with adverse events recorded to assess drug safety. Evaluations of serological conversion were carried out to measure treatment effectiveness. Vector control, entomological surveillance, and health education activities were carried out in all projects with close interaction with national and regional programs. RESULTS: Total numbers of children and adolescents tested for T. cruzi in Yoro, Olopa, Entre Ríos, and Sucre were 24,471, 8,927, 7,613, and 19,400, respectively. Of these, 232 (0.9%), 124 (1.4%), 1,475 (19.4%), and 1,145 (5.9%) patients, respectively, were diagnosed as seropositive. Patients were treated with benznidazole, and early findings of seroconversion varied widely between the Central and South American programs: 87.1% and 58.1% at 18 months post-treatment in Yoro and Olopa, respectively; 5.4% by up to 60 months in Entre Ríos; and 0% at an average of 18 months in Sucre. Benznidazole-related adverse events were observed in 50.2% and 50.8% of all patients treated in Yoro and Olopa, respectively, and 25.6% and 37.9% of patients in Entre Ríos and Sucre, respectively. Most adverse events were mild and manageable. No deaths occurred in the treatment population. CONCLUSIONS: These results demonstrate the feasibility of implementing Chagas disease diagnosis and treatment programs in resource-limited settings, including remote rural areas, while addressing the limitations associated with drug-related adverse events. The variability in apparent treatment effectiveness may reflect differences in patient and parasite populations, and illustrates the limitations of current treatments and measures of efficacy. New treatments with improved safety profiles, pediatric formulations of existing and new drugs, and a faster, reliable test of cure are all urgently needed

    House-level risk factors for triatomine infestation in Colombia.

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    BACKGROUND: Chagas disease, transmitted domestically by triatomine bugs, is the most important vector-borne disease in Latin America. The association between triatomine infestation and housing characteristics was investigated based on a standardized survey in 41 971 houses in 15 Departments in Colombia. METHODS: Multivariate logistic regression was used to test for associations of two highly correlated infestation measures of infestation (householders reporting having seen triatomines inside the house, and sending triatomines to the survey team), with 15 household-level risk factors. Risks were measured relative to a reference category of houses with up to three inhabitants, area up to 50 m(2), unplastered adobe walls, thatch roof and no outbuildings or domestic animals. RESULTS: The probability of seeing triatomines was highest for households with over seven inhabitants (OR = 1.24, 95% CI 1.11-1.39), overhead storage space (OR = 1.16, 95% CI 1.03-1.32), grain shed (OR = 1.25, 95% CI 1.02-1.52), cats (OR = 1.27, 95% CI 1.14-1.42) and pigs (OR = 1.16, 95% CI 1.03-1.30). Lowest risks were in houses with wooden walls (OR = 0.46, 95% CI 0.34-0.61), fully plastered walls (OR = 0.78, 95% CI 0.68-0.88), roofs made of tiles (OR = 0.51, 95% CI 0.33-0.78) and flagstone floors (OR = 0.57, 95% CI 0.42-0.76). Results for householders returning triatomines support this set of risk factors, but with wider confidence intervals. CONCLUSIONS: Surveillance of a few easily assessed household characteristics provides an accurate, rapid assessment of house-level variation in risk. Measured effect sizes for specific structural characteristics could be used to maximize the cost-effectiveness of programmes to reduce vector infestation and interrupt Chagas disease transmission by improving house quality
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