WorldWideScience

Sample records for abbot prism chagas

  1. PRISM

    Science.gov (United States)

    2017-12-21

    societal issues , given countervailing moral , legal, and ethical interpretations, as well as suspicions PRISM 7, NO. 2 FEATURES | 13 COGNITIVE-EMOTIONAL...to tell our story. Additionally, U.S. practi- tioners are bound by asymmetric legal, moral , and ethical constraints that often keep them from being...the founder of SpaceX and Tesla, withdrew from two business councils providing advice to the administration on economic issues . Further driving

  2. Chagas disease in prehistory.

    Science.gov (United States)

    Ferreira, Luiz F; Jansen, Ana M; Araújo, Adauto

    2011-09-01

    The classical hypothesis proposes that Chagas disease has been originated in the Andean region among prehistoric people when they started domesticating animals, changing to sedentary habits, and adopting agriculture. These changes in their way of life happened nearly 6,000 years ago. However, paleoparasitological data based on molecular tools showed that Trypanosoma cruzi infection and Chagas disease were commonly found both in South and North American prehistoric populations long before that time, suggesting that Chagas disease may be as old as the human presence in the American continent. The study of the origin and dispersion of Trypanosoma cruzi infection among prehistoric human populations may help in the comprehension of the clinical and epidemiological questions on Chagas disease that still remain unanswered.

  3. Influence of food diet in the radiosensitivity of spodoptera frugiperda smith abbot larvae

    International Nuclear Information System (INIS)

    Gonzalez, M.; Labrada, A.; Fundora, Z.; Herrera, A.

    1988-01-01

    To apply the traditional method in pest control it is needed to know the reaction capability of the insect in reference to radiations as well as the influence which can be exerted over it by different factors. The radiosensitivity of Spodoptera Frugiperda Smith Abbot larvae raised with two different diets (natural and artificial) was studied using doses between 20 and 100 Gy, in Co-60 gamma source with a dose power of 13.4 Gy/min survival, formation and dimensions of pupas, adult emergency and other interesting aspects were determined. The multiple analysis of results showed the influence of the food diet on radiosensitivity of larvae. results of both diets are statistically compared

  4. Retroreflective Phase Retardation Prisms.

    Science.gov (United States)

    1981-06-01

    resonant cavity of a 1.064 Mm laser. This report shows that it is possible to coat the reflecting surfaces of a porro prism so that incident plane...with controlled phase retardation can be made by coating each reflecting surface of a porro prism with a single dielectric film. The amount of phase...of angle of incidence (n, < n2) S. Phase change on reflection as a function of angle of incidence (n" n ) [RL-0202-’R 6. Porro prism 7. Phase change

  5. Chagas Disease (American trypanosomiasis)

    Science.gov (United States)

    ... sheets/detail/chagas-disease-(american-trypanosomiasis)","@context":"http://schema.org","@type":"Article"}; العربية 中文 français русский español ... capacities, focusing on: strengthening world epidemiological surveillance and information systems; preventing transmission by blood transfusion and organ ...

  6. A controllable spin prism

    International Nuclear Information System (INIS)

    Hakioglu, T

    2009-01-01

    Based on Khodas et al (2004 Phys. Rev. Lett. 92 086602), we propose a device acting like a controllable prism for an incident spin. The device is a large quantum well where Rashba and Dresselhaus spin-orbit interactions are present and controlled by the plunger gate potential, the electric field and the barrier height. A totally destructive interference can be manipulated externally between the Rashba and Dresselhaus couplings. The spin-dependent transmission/reflection amplitudes are calculated as the control parameters are changed. The device operates as a spin prism/converter/filter in different regimes and may stimulate research in promising directions in spintronics in analogy with linear optics.

  7. Reflection by Porro Prisms

    Science.gov (United States)

    Greenslade, Thomas B.

    2010-04-01

    Students all know that reflection from a plane mirror produces an image that is reversed right to left and so cannot be read by anyone but Leonardo da Vinci, who kept his notes in mirror writing. A useful counter-example is the Porro prism, which produces an image that is not reversed.

  8. The PRISM project

    Science.gov (United States)

    Guilyardi, E.

    2003-04-01

    The European Union's PRISM infrastructure project (PRogram for Integrated earth System Modelling) aims at designing a flexible environment to easily assemble and run Earth System Models (http://prism.enes.org). Europe's widely distributed modelling expertise is both a strength and a challenge. Recognizing this, the PRISM project aims at developing an efficient shared modelling software infrastructure for climate scientists, providing them with an opportunity for greater focus on scientific issues, including the necessary scientific diversity (models and approaches). The proposed PRISM system includes 1) the use - or definition - and promotion of scientific and technical standards to increase component modularity, 2) an end-to-end software environment (coupler, user interface, diagnostics) to launch, monitor and analyze complex Earth System Models built around the existing and future community models, 3) testing and quality standards to ensure HPC performance on a variety of platforms and 4) community wide inputs and requirements capture in all stages of system specifications and design through user/developers meetings, workshops and thematic schools. This science driven project, led by 22 institutes* and started December 1st 2001, benefits from a unique gathering of scientific and technical expertise. More than 30 models (both global and regional) have expressed interest to be part of the PRISM system and 6 types of components have been identified: atmosphere, atmosphere chemistry, land surface, ocean, sea ice and ocean biochemistry. Progress and overall architecture design will be presented. * MPI-Met (Coordinator), KNMI (co-coordinator), MPI-M&D, Met Office, University of Reading, IPSL, Meteo-France, CERFACS, DMI, SMHI, NERSC, ETH Zurich, INGV, MPI-BGC, PIK, ECMWF, UCL-ASTR, NEC, FECIT, SGI, SUN, CCRLE

  9. Abbot A. Barruel about the Causes and Organizers of the French Revolution

    Directory of Open Access Journals (Sweden)

    Sergey E. Kiyasov

    2017-12-01

    Full Text Available The article deal with the version of participation in the events of the French revolution of secret organizations, proposed by Catholic priest and publicist Augustin Barruel. According to the emigrant abbot, who became a witness and participant in the revolutionary processes, those events were organized by the conspirators represented by philosophers-enlighteners, masons and illuminati, who joined after 1789 in the Club of the Jacobins. A. Barruel shared his views in a multivolume work, which was published in London at the very end of the 18th century. The book aroused great interest and was translated into many languages, including Russian. From that moment, a “black legend” was approved in the assessment of the European Masonic movement. This legend explained all the revolutionary events by a destructive “Masonic conspiracy”. The author focuses the research on characterizing the real causes that had become the catalyst for the French revolution. In the context of criticism of Barruel’s views, the assessments are also given to the evolution of the Masonic movement in France of the 18th century. The author touches upon a very important problem of transformation of national Masonic organizations. This problem is considered in the context of the formation of the structures of the Great East of France. The article notes the close relationship of this structure with the elite and the Royal court. The undertaken analysis is based on the special literature and the original sources, such as The Constitutions by James Anderson – the first printed constitution of the premier Grand Lodge of England; Memoires by Augustin Barruel.

  10. Calibration of the Wedge Prism

    Science.gov (United States)

    Charles B. Briscoe

    1957-01-01

    Since the introduction of plotless cruising in this country by Grosenbaugh and the later suggestion of using a wedge prism as an angle gauge by Bruce this method of determining basal area has been widely adopted in the South. One of the factors contributing to the occasionally unsatisfactory results obtained is failure to calibrate the prism used. As noted by Bruce the...

  11. Geometric formula for prism deflection

    Indian Academy of Sciences (India)

    , governs deflections produced by prisms of refractive index n. The refractive power, n − 1, of most materials is of the order of unity for visible light, which therefore gets deflected through several degrees by a prism. X-rays and neutrons however ...

  12. Ventricular arrhythmias in Chagas disease

    Directory of Open Access Journals (Sweden)

    Marco Paulo Tomaz Barbosa

    2015-02-01

    Full Text Available Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias. A literature review was performed via a search of the PubMed database from 1965 to May 31, 2014 for studies of patients with Chagas disease. Clinical management of patients with chronic Chagas disease begins with proper clinical stratification and the identification of individuals at a higher risk of sudden cardiac death. Once a patient develops malignant ventricular arrhythmia, the therapeutic approach aims to prevent the recurrence of arrhythmias and sudden cardiac death by the use of implantable cardioverter defibrillators, antiarrhythmic drugs, or both. In select cases, invasive ablation of the reentrant circuit causing tachycardia may be useful. Ventricular arrhythmias are important manifestations of Chagas cardiomyopathy. This review highlights the absence of high-quality evidence regarding the treatment of ventricular arrhythmias in Chagas disease. Recognizing high-risk patients who require specific therapies, especially invasive procedures such as the implantation of cardioverter defibrillators and ablative approaches, is a major challenge in clinical practice.

  13. Simple Tidal Prism Models Revisited

    Science.gov (United States)

    Luketina, D.

    1998-01-01

    Simple tidal prism models for well-mixed estuaries have been in use for some time and are discussed in most text books on estuaries. The appeal of this model is its simplicity. However, there are several flaws in the logic behind the model. These flaws are pointed out and a more theoretically correct simple tidal prism model is derived. In doing so, it is made clear which effects can, in theory, be neglected and which can not.

  14. The PRISM concept

    International Nuclear Information System (INIS)

    Circeo, L.J. Jr.; Camacho, S.L.; Tixier, J.S.

    1994-01-01

    Contaminated soils and buried wastes represent one of the most widespread and costly remediation problems in the United States and other developed countries around the world. This concept of in situ remediation using a plasma arc torch should be directly applicable to many of the contaminated soil remediation needs described the DOE, EPA, and DoD. Plasma Remediation of In Situ Materials (PRISM) could provide a highly efficient, cost-effective, reliable and controllable technique to selectively melt and vitrify any contaminated/buried volume of soils, materials, or objects at any depth underground. If necessary, it could pinpoint underground objects such as buried drums for selective remediation. Plasma arc technology was developed over 30 years ago by NASA for the US space program to simulate reentry temperatures on heat shields. Only recently has this technology begun to emerge as a commercial tool in several industries such as steelmaking, metallurgy, precious metal recovery, and waste disposal. Conceptually, a plasma torch could be used on the ground surface or lowered to the bottom of a small diameter, cased borehole. By raising and operating the torch at progressively higher levels a column of contaminated material would be vitrified and converted into an environmentally safe, glassy residue, highly resistant to leaching. With proper borehole spacing the vitrified columns could be coalesced together to form a contiguous, homogeneous mass of vitrified material which is environmentally safe and highly resistant to leaching

  15. Chagas Disease: No Longer Exotic

    Centers for Disease Control (CDC) Podcasts

    2008-04-03

    This podcast is designed to inform health care providers about Chagas disease, diagnosis, and treatment and to assist in identifying infected patients.  Created: 4/3/2008 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 4/8/2008.

  16. PRISMES. The INES microgrid platform

    Energy Technology Data Exchange (ETDEWEB)

    Barruel, F.; Vervaart, M.; Merten, J. [INES, 73 - Le Bourget-du-lac (FR). Lab. for Solar Systems (L2S)

    2010-07-01

    The massive penetration of fluctuating renewable energies will challenge the low voltage grids. Innovative solutions to address this issue need to be developed and tested. They may consist of intelligent energy management systems and the use of storage systems. For this purpose the PRISMES platform has been designed and implemented at the INES headquarter in Chambery. It is a universal test and development tool, such as stand alone hybrid systems and grid connected PV systems combined with a storage system and loads. This paper describes the PRISMES facility which will start operation in autumn 2008. (orig.)

  17. 21 CFR 886.1660 - Gonioscopic prism.

    Science.gov (United States)

    2010-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1660 Gonioscopic prism. (a) Identification. A gonioscopic prism is a device that is a prism intended to be placed on the eye to study the anterior chamber. The device may have angled mirrors to facilitate visualization of anatomical features. (b...

  18. Experimental Chagas' disease in dogs

    Directory of Open Access Journals (Sweden)

    Marta de Lana

    1992-03-01

    Full Text Available This paper describes the development of experimental Chagas' disease in 64 out-bred young dogs. Twenty-nine animals were inoculated with the Be-62 and 35 with Be-78 Trypanosoma cruzi strains. Twenty-six were infected with blood trypomastigotes by different inoculation routes and 38 with metacyclic trypomastigotes from the vector via the conjunctival route. Twenty of the 26 dogs infected with blood trypomastigotes were autopsied during the acute phase. Eleven died spontaneously and nine were sacrificed. Six remained alive until they died suddenly (two or were autopsied (four. Twelve of the 38 dogs infected with metacyclic trypomastigotes evolved naturally to the chronic phase and remained alive for 24-48 months. The parasitemia, clinical aspects and serology (IgM and IgG as well as electrocardiogram, hemogram and heart anatomo-histopathologic patterns of acute and chronic cardiac forms of Chagas' disease as seen in human infections, were reproduced. The most important finding is the reproductibility of diffuse fibrosing chronic chagasic cardiopathy in all dogs infected with Be-78 T. cruzi strain autopsied between the 90th and 864th days of infection. Thus, the dog can be considered as a suitable experimental model to study Chagas' disease according to the requisites of the World Health Organization (1984. Futhermore the animal is easily obtained and easy to handle and maintain in experimental laboratory conditions.

  19. Enfermedad de Chagas en Nicaragua

    Directory of Open Access Journals (Sweden)

    Carlos N. Talavera - López

    2008-04-01

    Full Text Available LA ENFERMEDAD DE CHAGAS ES UN PROBLEMA DE SALUD pública en toda Latinoamérica; alrededor de 20 millones de personas están infectadas y 200 millones están en riesgo de contraer la enfermedad. En 2006, la prevalencia en Centroamérica era del 7%. Actualmente no existe vacuna contra el protozoo y el tratamiento disponible resulta, aparte de poco efectivo, muy tóxico para el paciente. Los programas de control de vectores han ayudado a reducir los índices de infestación en Latinoamérica, pero aún falta mucho por hacer. En Nicaragua, la enfermedad de Chagas está subvalorada y los trabajos publicados son muy pocos. Es necesario investigar sobre esta enfermedad en nuestro país con otro enfoque, uno que no subvalore la enfermedad y ayude a desarrollar métodos diagnósticos y posibles tratamientos. Este artículo recopila información sobre los trabajos realizados porlos grupos más importantes de investigación en Chagas de Nicaragua en cuanto a epidemiología, control vectorial, diagnóstico y caracterización molecular.

  20. Chagas disease risk in Texas.

    Science.gov (United States)

    Sarkar, Sahotra; Strutz, Stavana E; Frank, David M; Rivaldi, Chissa-Louise; Sissel, Blake; Sánchez-Cordero, Victor

    2010-10-05

    Chagas disease, caused by Trypanosoma cruzi, remains a serious public health concern in many areas of Latin America, including México. It is also endemic in Texas with an autochthonous canine cycle, abundant vectors (Triatoma species) in many counties, and established domestic and peridomestic cycles which make competent reservoirs available throughout the state. Yet, Chagas disease is not reportable in Texas, blood donor screening is not mandatory, and the serological profiles of human and canine populations remain unknown. The purpose of this analysis was to provide a formal risk assessment, including risk maps, which recommends the removal of these lacunae. The spatial relative risk of the establishment of autochthonous Chagas disease cycles in Texas was assessed using a five-stage analysis. 1. Ecological risk for Chagas disease was established at a fine spatial resolution using a maximum entropy algorithm that takes as input occurrence points of vectors and environmental layers. The analysis was restricted to triatomine vector species for which new data were generated through field collection and through collation of post-1960 museum records in both México and the United States with sufficiently low georeferenced error to be admissible given the spatial resolution of the analysis (1 arc-minute). The new data extended the distribution of vector species to 10 new Texas counties. The models predicted that Triatoma gerstaeckeri has a large region of contiguous suitable habitat in the southern United States and México, T. lecticularia has a diffuse suitable habitat distribution along both coasts of the same region, and T. sanguisuga has a disjoint suitable habitat distribution along the coasts of the United States. The ecological risk is highest in south Texas. 2. Incidence-based relative risk was computed at the county level using the Bayesian Besag-York-Mollié model and post-1960 T. cruzi incidence data. This risk is concentrated in south Texas. 3. The

  1. Chagas disease risk in Texas.

    Directory of Open Access Journals (Sweden)

    Sahotra Sarkar

    Full Text Available BACKGROUND: Chagas disease, caused by Trypanosoma cruzi, remains a serious public health concern in many areas of Latin America, including México. It is also endemic in Texas with an autochthonous canine cycle, abundant vectors (Triatoma species in many counties, and established domestic and peridomestic cycles which make competent reservoirs available throughout the state. Yet, Chagas disease is not reportable in Texas, blood donor screening is not mandatory, and the serological profiles of human and canine populations remain unknown. The purpose of this analysis was to provide a formal risk assessment, including risk maps, which recommends the removal of these lacunae. METHODS AND FINDINGS: The spatial relative risk of the establishment of autochthonous Chagas disease cycles in Texas was assessed using a five-stage analysis. 1. Ecological risk for Chagas disease was established at a fine spatial resolution using a maximum entropy algorithm that takes as input occurrence points of vectors and environmental layers. The analysis was restricted to triatomine vector species for which new data were generated through field collection and through collation of post-1960 museum records in both México and the United States with sufficiently low georeferenced error to be admissible given the spatial resolution of the analysis (1 arc-minute. The new data extended the distribution of vector species to 10 new Texas counties. The models predicted that Triatoma gerstaeckeri has a large region of contiguous suitable habitat in the southern United States and México, T. lecticularia has a diffuse suitable habitat distribution along both coasts of the same region, and T. sanguisuga has a disjoint suitable habitat distribution along the coasts of the United States. The ecological risk is highest in south Texas. 2. Incidence-based relative risk was computed at the county level using the Bayesian Besag-York-Mollié model and post-1960 T. cruzi incidence data. This

  2. The chronic gastrointestinal manifestations of Chagas disease

    Directory of Open Access Journals (Sweden)

    Nilce Mitiko Matsuda

    2009-01-01

    Full Text Available Chagas disease is an infectious disease caused by the protozoan Trypanosoma cruzi. The disease mainly affects the nervous system, digestive system and heart. The objective of this review is to revise the literature and summarize the main chronic gastrointestinal manifestations of Chagas disease. The chronic gastrointestinal manifestations of Chagas disease are mainly a result of enteric nervous system impairment caused by T. cruzi infection. The anatomical locations most commonly described to be affected by Chagas disease are salivary glands, esophagus, lower esophageal sphincter, stomach, small intestine, colon, gallbladder and biliary tree. Chagas disease has also been studied in association with Helicobacter pylori infection, interstitial cells of Cajal and the incidence of gastrointestinal cancer.

  3. Prism. Volume 1, Number 1, December 2009

    Science.gov (United States)

    2009-12-01

    strategy, regional security affairs, and global strategic problems. This is the authoritative , official U.S. Department of Defense edition of PRISM...suffer from illiteracy, poor health, and extreme poverty PRISM 1, no. 1 FRoM the FIeld | 89 The country’s maternal mortality and female illiteracy rates...problems. This is the authoritative , official U.S. Department of Defense edition of PRISM. Any copyrighted portions of this journal may not be

  4. Neutron forward diffraction by single crystal prisms

    Indian Academy of Sciences (India)

    We have derived analytic expressions for the deflection as well as transmitted fraction of monochromatic neutrons forward diffracted by a single crystal prism. In the vicinity of a Bragg reflection, the neutron deflection deviates sharply from that for an amorphous prism, exhibiting three orders of magnitude greater sensitivity to ...

  5. Analysis of unscrammed events in PRISM

    International Nuclear Information System (INIS)

    Slovik, G.C.; Van Tuyle, G.J.

    1990-01-01

    The PRISM reactor is presently under pre-application licensing review by the NRC, with Brookhaven National Laboratory (BNL) providing technical assistance. The purpose of this paper is to review the current PRISM design and describe the results from the SSC Code calculations performed at BNL, for a series of unscrammed accidents. 3 refs., 5 figs

  6. Carlos Chagas Discoveries as a Drop Back to Scientific Construction of Chronic Chagas Heart Disease.

    Science.gov (United States)

    Bestetti, Reinaldo B; Restini, Carolina Baraldi A; Couto, Lucélio B

    2016-07-01

    The scientific construction of chronic Chagas heart disease (CCHD) started in 1910 when Carlos Chagas highlighted the presence of cardiac arrhythmia during physical examination of patients with chronic Chagas disease, and described a case of heart failure associated with myocardial inflammation and nests of parasites at autopsy. He described sudden cardiac death associated with arrhythmias in 1911, and its association with complete AV block detected by Jacquet's polygraph as Chagas reported in 1912. Chagas showed the presence of myocardial fibrosis underlying the clinical picture of CCHD in 1916, he presented a full characterization of the clinical aspects of CCHD in 1922. In 1928, Chagas detected fibrosis of the conductive system, and pointed out the presence of marked cardiomegaly at the chest X-Ray associated with minimal symptomatology. The use of serological reaction to diagnose CCHD was put into clinical practice in 1936, after Chagas' death, which along with the 12-lead ECG, revealed the epidemiological importance of CCHD in 1945. In 1953, the long period between initial infection and appearance of CCHD was established, whereas the annual incidence of CCHD from patients with the indeterminate form of the disease was established in 1956. The use of heart catheterization in 1965, exercise stress testing in 1973, Holter monitoring in 1975, Electrophysiologic testing in 1973, echocardiography in 1975, endomyocardial biopsy in 1981, and Magnetic Resonance Imaging in 1995, added to the fundamental clinical aspects of CCHD as described by Carlos Chagas.

  7. Carlos Chagas Discoveries as a Drop Back to Scientific Construction of Chronic Chagas Heart Disease

    Energy Technology Data Exchange (ETDEWEB)

    Bestetti, Reinaldo B., E-mail: rbestetti44@gmail.com; Restini, Carolina Baraldi A.; Couto, Lucélio B. [Universidade de Ribeirão Preto, Ribeirão Preto, São Paulo, SP (Brazil)

    2016-07-15

    The scientific construction of chronic Chagas heart disease (CCHD) started in 1910 when Carlos Chagas highlighted the presence of cardiac arrhythmia during physical examination of patients with chronic Chagas disease, and described a case of heart failure associated with myocardial inflammation and nests of parasites at autopsy. He described sudden cardiac death associated with arrhythmias in 1911, and its association with complete AV block detected by Jacquet's polygraph as Chagas reported in 1912. Chagas showed the presence of myocardial fibrosis underlying the clinical picture of CCHD in 1916, he presented a full characterization of the clinical aspects of CCHD in 1922. In 1928, Chagas detected fibrosis of the conductive system, and pointed out the presence of marked cardiomegaly at the chest X-Ray associated with minimal symptomatology. The use of serological reaction to diagnose CCHD was put into clinical practice in 1936, after Chagas' death, which along with the 12-lead ECG, revealed the epidemiological importance of CCHD in 1945. In 1953, the long period between initial infection and appearance of CCHD was established, whereas the annual incidence of CCHD from patients with the indeterminate form of the disease was established in 1956. The use of heart catheterization in 1965, exercise stress testing in 1973, Holter monitoring in 1975, Electrophysiologic testing in 1973, echocardiography in 1975, endomyocardial biopsy in 1981, and Magnetic Resonance Imaging in 1995, added to the fundamental clinical aspects of CCHD as described by Carlos Chagas.

  8. Carlos Chagas Discoveries as a Drop Back to Scientific Construction of Chronic Chagas Heart Disease

    Directory of Open Access Journals (Sweden)

    Reinaldo B. Bestetti

    2016-01-01

    Full Text Available Abstract The scientific construction of chronic Chagas heart disease (CCHD started in 1910 when Carlos Chagas highlighted the presence of cardiac arrhythmia during physical examination of patients with chronic Chagas disease, and described a case of heart failure associated with myocardial inflammation and nests of parasites at autopsy. He described sudden cardiac death associated with arrhythmias in 1911, and its association with complete AV block detected by Jacquet's polygraph as Chagas reported in 1912. Chagas showed the presence of myocardial fibrosis underlying the clinical picture of CCHD in 1916, he presented a full characterization of the clinical aspects of CCHD in 1922. In 1928, Chagas detected fibrosis of the conductive system, and pointed out the presence of marked cardiomegaly at the chest X-Ray associated with minimal symptomatology. The use of serological reaction to diagnose CCHD was put into clinical practice in 1936, after Chagas' death, which along with the 12-lead ECG, revealed the epidemiological importance of CCHD in 1945. In 1953, the long period between initial infection and appearance of CCHD was established, whereas the annual incidence of CCHD from patients with the indeterminate form of the disease was established in 1956. The use of heart catheterization in 1965, exercise stress testing in 1973, Holter monitoring in 1975, Electrophysiologic testing in 1973, echocardiography in 1975, endomyocardial biopsy in 1981, and Magnetic Resonance Imaging in 1995, added to the fundamental clinical aspects of CCHD as described by Carlos Chagas.

  9. The Prism Plastic Calorimeter (PPC)

    CERN Multimedia

    2002-01-01

    This proposal supports two goals: \\\\ \\\\ First goal:~~Demonstrate that current, widely used plastic technologies allow to design Prism Plastic Calorimeter~(PPC) towers with a new ``liquid crystal'' type plastic called Vectra. It will be shown that this technique meets the requirements for a LHC calorimeter with warm liquids: safety, hermeticity, hadronic compensation, resolution and time response. \\\\ \\\\ Second goal:~~Describe how one can design a warm liquid calorimeter integrated into a LHC detector and to list the advantages of the PPC: low price, minimum of mechanical structures, minimum of dead space, easiness of mechanical assembly, accessibility to the electronics, possibility to recirculate the liquid. The absorber and the electronic being outside of the liquid and easily accessible, one has maximum flexibility to define them. \\\\ \\\\ The R&D program, we define here aims at showing the feasibility of these new ideas by building nine towers of twenty gaps and exposing them to electron and hadron beams.

  10. Honduras stands out in fight against chagas disease | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-01-25

    Jan 25, 2011 ... The model is based on community involvement to both treat and prevent Chagas. ... treat children with Chagas and educate the population on how to control ... parents, children, and community leaders—monitored homes and ...

  11. American Trypanosomiasis (Also Known as Chagas Disease) Detailed FAQs

    Science.gov (United States)

    ... I prevent infection? What is Chagas disease? Chagas disease is caused by the parasite Trypanosoma cruzi , which is transmitted to animals and people by insect vectors that are found only in the Americas (mainly, ...

  12. Enfermedad de Chagas en Colombia

    Directory of Open Access Journals (Sweden)

    Fernando Serpa Florez

    1985-12-01

    Full Text Available

    Generalidades.

    La tripanosomiasis americana o enfermedad de Chagas se halla ampliamente distribuida en Centro y Sur América. La Organización Mundial de la Salud considera que pueden haber doce millones de casos de esta dolencia en el continente (1, estudiados principalmente en Argentina, Brasil y Venezuela. Se calcula que en Colombia tendríamos una incidencia muy alta de casos, (Marinkelle (2 estima que 7.140/0 de la población podría estar infectada o sea cerca de dos millones de personas, distribuidos en las zonas rurales del nordeste del país (cuenca del Catatumbo Magdalena Medio y Llanos Orientales (Piedemonte, Macarena y Meta cercano (3 (4 (5 Y que seis millones de nuestros compatriotas -22.30/0 de la población total- (2 corren el riesgo de adquirir la enfermedad pues habitan en regiones donde se dan las condiciones para que ésta se propague.


    RESEÑA HISTORICA DE LA ENFERMEDAD EN COLOMBIA
    La existencia de casos de tripanosomiasis americana y de sus vectores fue comprobada en Colombia desde 1929 cuando César Uribe Piedrahita (6 encontró en Prado, Tolima, vectores del mal infectados con T.

    cruzi e Ignacio Moreno Pérez observó dicho hemoflagelado en sangre de seres humanos en Cali (4. En los años siguientes Hernando Ucrós, Benjamín Otálora, Hernando Groot, Santiago Renjifo, Hernando Osorno, Carlos Duarte Rangel, C.J. Marinkelle, Augusto Corredor, Ernesto Suescún y varios otros investigadores colomb iano s describieron diversos focos de la enfermedad en Colombia y estudiaron la distribución de sus vectores y huéspedes intermediarios. En 1947 1. Caicedo y C. Hernández publicaron su informe sobre los primeros casos crónicos de enfermedad de Chagas comprobados en nuestro país, procedentes de la región de Fusagasugá, Cundinamarca (7 en tanto que, en 1961, Marcos Duque inicia los estudios sobre cardiopatía chagásica (8 y Hernando Rocha, en 1971, comunica

  13. 21 CFR 886.1650 - Ophthalmic bar prism.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic bar prism. 886.1650 Section 886.1650...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1650 Ophthalmic bar prism. (a) Identification. An ophthalmic bar prism is a device that is a bar composed of fused prisms of gradually increasing...

  14. Behaviour and strength assessment of masonry prisms

    Directory of Open Access Journals (Sweden)

    Nassif Nazeer Thaickavil

    2018-06-01

    Full Text Available This is a case study presenting the cracking behavior and assessment of the compressive strength of masonry prisms. The compressive strength of masonry was determined by performing laboratory tests on 192 masonry prism specimens corresponding to 3 specimens each in 64 groups. The variables considered in the experimental program are type of brick, strength of masonry and height-to-thickness (h/t ratio of the prism specimen. Pressed earth bricks and burnt clay bricks were used for the preparation of masonry prisms. A mathematical model is also proposed for the estimation of compressive strength of masonry prisms by performing a statistical multiple regression analysis on 232 data sets, which includes 64 test data from the present study and 168 test data published in the literature. The model was developed based on the regression analysis of test data of prisms made of a variety of masonry units namely clay bricks, pressed earth bricks, concrete blocks, calcium silicate bricks, stone blocks, perforated bricks and soft mud bricks. The proposed model not only accounts for the wide ranges of compressive strengths of masonry unit and mortar, but also accounts for the influence of volume fractions of masonry unit and mortar in addition to the height-to-thickness ratio. The predicted compressive strength of prisms using the proposed model is compared with 14 models available in published literature. The predicted strength was found to be in good agreement with the corresponding experimental data. Keywords: Prism strength, Stack bonded masonry, Running bonded masonry, Masonry unit strength, Cracking

  15. [Institutional insertion of Chagas' disease control].

    Science.gov (United States)

    Silveira, Antônio Carlos; Pimenta, Fabiano

    2011-01-01

    After the starting of the Center for studies and prophylaxis of Chagas disease in 1943, with the help of Oswaldo Cruz Foundation, in the city of Bambuí, state of Minas Gerais, technological and methodological basis for the extensive control of the disease were conceived. A main step to achieve success was the introduction of a new insecticide (gammexane, P 530) and the demonstration of its efficacy in the vector control. A consequence of these improvements was the official inauguration of the first prophylactic campaign for Chagas disease in Brazil, held in Uberaba in May, 1950. Even with the knowledge of how to control the vectorial transmission, financial resources were not available by this time, at a necessary degree to make it both regularly and in all the affected area. The institutional allocation of these activities is useful to understand the low priority given to them at that time. Several national services were created in 1941, for diseases as malaria, pest, smallpox, among others, but Chagas was included in a group of diseases with lower importance, inside a Division of Sanitary Organization. In 1956, the National Department of Rural endemies (DNERu) allocate all the major endemic diseases in a single institution, however this was not translated in an implementation program for the control of Chagas disease. After profound changes at the Ministry of Health, in 1970, the Superintendência de Campanhas de Saúde Pública (SUCAM) was in charge of all rural endemies including Chagas disease, which now could compete with other diseases transmitted by vectors, formerly priorities, included in the National Division. With this new status, more funds were available, as well as redistribution of personnel and expenses from the malaria program to the vectorial control of Chagas disease. In 1991 the Health National foundation was created to substitute SUCAM in the control of endemic diseases and it included all the units of the Ministry of Health related to

  16. A mathematical model of Chagas disease transmission

    Science.gov (United States)

    Hidayat, Dayat; Nugraha, Edwin Setiawan; Nuraini, Nuning

    2018-03-01

    Chagas disease is a parasitic infection caused by protozoan Trypanosoma cruzi which is transmitted to human by insects of the subfamily Triatominae, including Rhodnius prolixus. This disease is a major problem in several countries of Latin America. A mathematical model of Chagas disease with separate vector reservoir and a neighboring human resident is constructed. The basic reproductive ratio is obtained and stability analysis of the equilibria is shown. We also performed sensitivity populations dynamics of infected humans and infected insects based on migration rate, carrying capacity, and infection rate parameters. Our findings showed that the dynamics of the infected human and insect is mostly affected by carrying capacity insect in the settlement.

  17. The PRISM3D paleoenvironmental reconstruction

    Science.gov (United States)

    Dowsett, H.; Robinson, M.; Haywood, A.M.; Salzmann, U.; Hill, Daniel; Sohl, L.E.; Chandler, M.; Williams, Mark; Foley, K.; Stoll, D.K.

    2010-01-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) paleoenvironmental reconstruction is an internally consistent and comprehensive global synthesis of a past interval of relatively warm and stable climate. It is regularly used in model studies that aim to better understand Pliocene climate, to improve model performance in future climate scenarios, and to distinguish model-dependent climate effects. The PRISM reconstruction is constantly evolving in order to incorporate additional geographic sites and environmental parameters, and is continuously refined by independent research findings. The new PRISM three dimensional (3D) reconstruction differs from previous PRISM reconstructions in that it includes a subsurface ocean temperature reconstruction, integrates geochemical sea surface temperature proxies to supplement the faunal-based temperature estimates, and uses numerical models for the first time to augment fossil data. Here we describe the components of PRISM3D and describe new findings specific to the new reconstruction. Highlights of the new PRISM3D reconstruction include removal of Hudson Bay and the Great Lakes and creation of open waterways in locations where the current bedrock elevation is less than 25m above modern sea level, due to the removal of the West Antarctic Ice Sheet and the reduction of the East Antarctic Ice Sheet. The mid-Piacenzian oceans were characterized by a reduced east-west temperature gradient in the equatorial Pacific, but PRISM3D data do not imply permanent El Niño conditions. The reduced equator-to-pole temperature gradient that characterized previous PRISM reconstructions is supported by significant displacement of vegetation belts toward the poles, is extended into the Arctic Ocean, and is confirmed by multiple proxies in PRISM3D. Arctic warmth coupled with increased dryness suggests the formation of warm and salty paleo North Atlantic Deep Water (NADW) and a more vigorous thermohaline circulation system that may

  18. Objective-prism spectrophotometry of quasars

    International Nuclear Information System (INIS)

    Clowes, R.G.

    1980-01-01

    A procedure is derived for obtaining low-resolution spectrophotometry of quasars directly from the objective-prism plates on which they were discovered. Measurements with a PDS microdensitometer of approximately 130 quasar candidates in approximately the central 19 square degrees of the UK Schmidt prism plate UJ3682P were used in the application of the procedure. The success of the objective-prism spectrophotometry is demonstrated in a comparison with 12 slit spectra. Redshifts and equivalent widths can be determined with typical discrepancies of 1% and 40% respectively. This work on objective-prism spectrophotometry leads to a quantification of the selection effects that operate in the searches for emission-line objects on objective-prism plates. The quantification successfully explains an apparent discrepancy in the detection efficiencies of the CTIO-4m and Curtis Schmidt surveys for quasars. Spectra of quasars that were observed with the Image Photon Counting System on the Anglo-Australian Telescope are presented. The observations of quasars with broad absorption troughs indicate the ejection of matter with velocities up to approximately 22000kms -1 and with velocity dispersions up to approximately 11000kms -1 . Data on the wavelength dependences of the contrast γ and the grain response function g of the Kodak emulsion IIIaJ are presented. (author)

  19. Porro prism lasers: a new perspective

    Science.gov (United States)

    Burger, Liesl; Forbes, Andrew

    2008-08-01

    Porro prism lasers are insensitive to misalignment caused by, for example, shock and temperature variation, making them useful in field applications, for example in target designation and range-finding systems. This property is a result of the property of Porro prisms that they return a reflected beam parallel to the incident beam, regardless of any tilt on the prism. These lasers are generally used in a marginally stable or unstable configuration for low divergence, but in the stable configuration some interesting kaleidoscope modes can be modelled. In previous work on Porro prism resonators we formulated an analytical method of determining which Porro angles resonate and result in petal output modes, as well as the corresponding number of petals. This work has been verified using a numerical model as well as experimentally. We have developed this work further and have investigated the losses associated with a range of Porro angles as well as the effects of these losses on the resulting modes. We conclude by summarizing the design considerations for Porro prism lasers.

  20. Transient performance of S-prism

    International Nuclear Information System (INIS)

    Dubberley, A.E.; Boardman, C.E.; Gamble, R.E.; Hiu, M.M.; Lipps, A.J.; Wu, T.

    2001-01-01

    S-PRISM is an advanced Fast Reactor plant design that utilizes compact modular pool-type reactors sized to enable factory fabrication and an affordable prototype test of a single Nuclear Steam Supply System (NSSS) for design certification at minimum cost and risk. Based on the success of the previous DOE sponsored Advanced Liquid Metal Reactor (ALMR) program GE has continued to develop and assess the technical viability and economic potential of an up-rated plant called SuperPRISM (S-PRISM). This paper presents the results of transient analyses performed to assess the ability of S-PRISM to accommodate severe accident initiator events. A unique safety capability of S-PRISM is accommodation of the ''higher probability'' accident initiators that led to core melt accidents in prior large LMRs. These events, the Anticipated Transients Without Scram (ATWS) events, are thus the focus of passive safety confirmation analyses. The events included in this assessment are: Unprotected Loss of Flow, Unprotected Loss of Heat Sink, Unprotected Loss of Flow and Heat sink, Unprotected Transient Overpower and Unprotected Safe Shutdown Earthquake. (author)

  1. Chagas disease. A new pathophysiological assessment

    International Nuclear Information System (INIS)

    Redruello, M.; Masoli, O.; Hasson, I.; Cragnolino, D.; Traverso, S.; Perez Balino, N.; Sarmiento, R.; Lazzari, J.; Luluaga, E.

    2002-01-01

    Background: There is scarce information on myocardial perfusion abnormalities and on the coronary vasomotor condition in Chagas disease patients. Aims: To assess regional perfusion abnormalities and the coronary vasomotor response of patients in the chronic phase of Chagas disease. Methods: With the use of 99mTc-sestamibi SPECT imaging and cold pressor test and intracoronary acetylcoline (ACH) perfusion, we studied 9 patients aged 42,6±12 years, 4 males, in the chronic stage of Chagas disease (5 with the indeterminate form and 4 with heart lesion) with normal coronary arteries. Vasomotor responses to intracoronary increasing doses of ACH and to a single dose of nitroglycerine (NTG) were assessed with digital quantitative angiography. Regional myocardial perfusion was evaluated at rest and after cold pressor test by a semi quantitative score analysis in an 18-segment model with 99mTc-sestamibi SPECT images. Results were expressed as mean ± 2SD. Differences between continuous variables were measured by two tails Student's t test for paired variables and the significance level was set at 5 %. Results: All patients had regional perfusion defects and abnormal vasomotor response. The diameter of the left anterior descending artery decreased 34% from a basal diameter of 3.66∫0.95 mm down to 2.42±0.74 mm after maximal response to ACH (p<0.002). NTG infusion augmented its diameter to 3.86±0.77 mm (p<0.0002) that is a 60% increase from post ACH diameter. Myocardial perfusion score was 1∫2.66 at rest and 6.22±3.6 after cold pressor test (p<0.0001). Conclusions: This group of patients in the chronic phase of Chagas disease showed an abnormal vasoconstrictive response to intracoronary ACH and cold-induced perfusion defects suggesting that endothelial dysfunction plays a role in the pathophysiology of chronic Chagas heart disease

  2. Serodiagnosis of chronic Chagas infection by using EIE-Recombinant-Chagas-Biomanguinhos kit

    Directory of Open Access Journals (Sweden)

    Gomes Yara M

    2001-01-01

    Full Text Available A kit based on an enzyme immunoassay, EIE-Recombinant-Chagas-Biomanguinhos, developed by the Oswaldo Cruz Foundation, was evaluated for the serodiagnosis of chronic Chagas disease. Evaluation was performed with 368 serum samples collected from individuals living in an endemic area for Chagas disease: 131 patients in the chronic phase with confirmed clinical, epidemiological, and serological diagnosis (indirect immunofluorescence, indirect hemagglutination or enzyme-linked immunosorbent assay and 237 nonchagasic seronegative individuals were considered negative control. The EIE-Recombinant-Chagas-Biomanguinhos kit showed high sensitivity, 100% (CI 95%: 96.4-100% and high specificity, 100% (CI 95%: 98-100%. The data obtained were in full agreement with clinical and conventional serology data. In addition, no cross-reaction was observed with sera from patients with cutaneous (n=14 and visceral (n=3 leishmaniasis. However, when these sera were tested by conventional serological assays for Chagas disease, cross-reactions were detected in 14.3% and 33.3% of the patients with cutaneous and visceral leishmaniasis, respectively. No cross-reactions were observed when sera from nonchagasic seronegative patients bearing other infectious disease (syphilis, n=8; HTLV, n=8; HCV, n=7 and HBV, n=12 were tested. In addition, sera of patients with inconclusive results for Chagas disease by conventional serology showed results in agreement with clinical evaluation, when tested by the kit. These results are relevant and indicate that the refered kit provides a safe immunodiagnosis of Chagas disease and could be used in blood bank screening.

  3. GE advanced liquid metal reactor S-PRISM

    International Nuclear Information System (INIS)

    Boardman, C.

    2001-01-01

    This presentation covers the following topics: Incentive for developing S-PRISM; Design and safety approach; Design description and competitive potential; Previous Licensing interactions; Planned approach to Licensing S-PRISM

  4. Comparing Volumes of Prisms and Pyramids

    Science.gov (United States)

    Vinogradova, Natalya

    2012-01-01

    Students' experience in using formulas for volumes is often limited to substituting numbers into given formulas. An activity presented in this article may help students make connections between the formulas for volumes of prisms and volumes of pyramids. In addition, some interesting facts from number theory arise, demonstrating strong connections…

  5. [Seroepidemiology of Chagas disease in Mexico].

    Science.gov (United States)

    Velasco-Castrejón, O; Valdespino, J L; Tapia-Conyer, R; Salvatierra, B; Guzmán-Bracho, C; Magos, C; Llausás, A; Gutiérrez, G; Sepúlveda, J

    1992-01-01

    The lack of information about Chagas disease in Mexico, as well as the controversy concerning its importance, was the basis for the seroprevalence study of Trypanosoma cruzi in the National Seroepidemiology Survey (NSS). This information was representative of the national situation with regard to disease prevalences and other factors related to the nation's health. Unfortunately the NSS was not a very good information source for the study of trypanosomiasis americana, because its coverage in the disperse rural areas was poor. Nevertheless, the results of the NSS indicated that Chagas disease has an irregular distribution in Mexico with seroprevalences of 1.6, 0.5 and 0.2 for the different dilution levels used in the evaluation. The survey data showed Chagas disease to be less important than that mentioned by other authors. The NSS data confirmed the areas of disease transmission already reported and identified some new ones in Hidalgo, Chiapas and Veracruz. The survey also detected migratory workers with Chagas antibodies in Baja California border cities, a situation which indicates a risk for blood transfusion in areas of the country presumed to be free of the disease. Three quarters (74.5%) of the seropositive population were less than 39 years old. Moreover, the fact that children of less than four years were infected suggests that natural transmission is still very important in some areas. Although the seroprevalences were greater in the lower socio-economic groups, some persons of the higher socio-economic level were also affected. This situation may be explained by the fact that many of these persons own vacation homes in tropical areas.

  6. Boolean Operations with Prism Algebraic Patches

    Science.gov (United States)

    Bajaj, Chandrajit; Paoluzzi, Alberto; Portuesi, Simone; Lei, Na; Zhao, Wenqi

    2009-01-01

    In this paper we discuss a symbolic-numeric algorithm for Boolean operations, closed in the algebra of curved polyhedra whose boundary is triangulated with algebraic patches (A-patches). This approach uses a linear polyhedron as a first approximation of both the arguments and the result. On each triangle of a boundary representation of such linear approximation, a piecewise cubic algebraic interpolant is built, using a C1-continuous prism algebraic patch (prism A-patch) that interpolates the three triangle vertices, with given normal vectors. The boundary representation only stores the vertices of the initial triangulation and their external vertex normals. In order to represent also flat and/or sharp local features, the corresponding normal-per-face and/or normal-per-edge may be also given, respectively. The topology is described by storing, for each curved triangle, the two triples of pointers to incident vertices and to adjacent triangles. For each triangle, a scaffolding prism is built, produced by its extreme vertices and normals, which provides a containment volume for the curved interpolating A-patch. When looking for the result of a regularized Boolean operation, the 0-set of a tri-variate polynomial within each such prism is generated, and intersected with the analogous 0-sets of the other curved polyhedron, when two prisms have non-empty intersection. The intersection curves of the boundaries are traced and used to decompose each boundary into the 3 standard classes of subpatches, denoted in, out and on. While tracing the intersection curves, the locally refined triangulation of intersecting patches is produced, and added to the boundary representation. PMID:21516262

  7. An improved prism for use in laser resonators

    Science.gov (United States)

    Richards, J.

    1981-08-01

    The use of compound total internal reflection prisms rather than Porro prisms in polarisation coupled lasers is proposed. Performance advantages resulting from the use of these prisms include higher output without the need to bias the Pockels cell, ability to give a larger range of output coupling and independence of performance on the refractive index of the prism. In conventional Q-switched lasers the use of the prism at the Pockels cell end of the resonator instead of the usual 100% reflecting mirror also leads to some advantages including better hold-off, elimination of the need to bias the Pockels cell and insensitivity in one plane to angular misalignment.

  8. Molecular Epidemiologic Source Tracking of Orally Transmitted Chagas Disease, Venezuela

    Science.gov (United States)

    Segovia, Maikell; Martínez, Clara E.; Messenger, Louisa A.; Nessi, Anaibeth; Londoño, Juan C.; Espinosa, Raul; Martínez, Cinda; Alfredo, Mijares; Bonfante-Cabarcas, Rafael; Lewis, Michael D.; de Noya, Belkisyolé A.; Miles, Michael A.; Llewellyn, Martin S.

    2013-01-01

    Oral outbreaks of Chagas disease are increasingly reported in Latin America. The transitory presence of Trypanosoma cruzi parasites within contaminated foods, and the rapid consumption of those foods, precludes precise identification of outbreak origin. We report source attribution for 2 peri-urban oral outbreaks of Chagas disease in Venezuela via high resolution microsatellite typing. PMID:23768982

  9. Multivariable control for the PRISM ALMR

    International Nuclear Information System (INIS)

    Wilson, T.L.; Wagner, W.K.

    1989-01-01

    This paper describes the application of state variable control design methods in the conceptual design of two key system level controllers in the PRISM ALMR. The PRISM plant concept consists of three power blocks, each made up of three identical reactors and steam generator modules connected to one turbine. Operation of these physically distributed systems is directed by a hierarchy of controllers at the system, power block, and plant levels. The system level controllers in this paper are the reactivity controllers for movement of the six control rods in each of the nine reactor modules, and the feedwater control of the three parallel steam generators in each of the three power blocks. 4 refs., 6 figs., 1 tab

  10. Automated analysis of objective-prism spectra

    International Nuclear Information System (INIS)

    Hewett, P.C.; Irwin, M.J.; Bunclark, P.; Bridgeland, M.T.; Kibblewhite, E.J.; Smith, M.G.

    1985-01-01

    A fully automated system for the location, measurement and analysis of large numbers of low-resolution objective-prism spectra is described. The system is based on the APM facility at the University of Cambridge, and allows processing of objective-prism, grens or grism data. Particular emphasis is placed on techniques to obtain the maximum signal-to-noise ratio from the data, both in the initial spectral estimation procedure and for subsequent feature identification. Comparison of a high-quality visual catalogue of faint quasar candidates with an equivalent automated sample demonstrates the ability of the APM system to identify all the visually selected quasar candidates. In addition, a large population of new, faint (msub(J)approx. 20) candidates is identified. (author)

  11. Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation.

    Science.gov (United States)

    Christophe, Laure; Chabanat, Eric; Delporte, Ludovic; Revol, Patrice; Volckmann, Pierre; Jacquin-Courtois, Sophie; Rossetti, Yves

    Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, prism adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of prism adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during, and following a one-week intense prism adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive prism adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of prism adaptation deserves further investigations.

  12. Evaluations of 1990 PRISM design revisions

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.; Slovik, G.C.; Chan, B.C.; Aronson, A.L.; Kennett, R.J.

    1992-03-01

    Analyses of the 1990 version of the PRISM Advanced Liquid Metal Reactor (ALMR) design are presented and discussed. Most of the calculations were performed using BNL computer codes, particularly SSC and MINET. In many cases, independent BNL calculations were compared against analyses presented by General Electric when they submitted the PRISM design revisions for evaluation by the Nuclear Regulatory Commission (NRC). The current PRISM design utilizes the metallic fuel developed by Argonne National Laboratory (ANL) which facilitates the passive/''inherent'' shutdown mechanism that acts to shut down reactor power production whenever the system overheats. There are a few vulnerabilities in the passive shutdown, with the most worrisome being the positive feedback from sodium density decreases or sodium voiding. Various postulated unscrammed events were examined by GE and/or BNL, and much of the analysis discussed in this report is focused on this category of events. For the most part, the BNL evaluations confirm the information submitted by General Electric. The principal areas of concern are related to the performance of the ternary metal fuel, and may be resolved as ANL continues with its fuel development and testing program

  13. PRISM reactor. An option for plutonium disposition?

    Energy Technology Data Exchange (ETDEWEB)

    Fehlinger, Sebastian; Friess, Friederike; Kuett, Moritz [IANUS, Technische Universitaet Darmstadt (Germany)

    2015-07-01

    The Power Reactor Innovative Small Module (PRISM) is sodium cooled fast reactor model. The energy output depends on the core configuration, however with an energy output of approximately 300 MWe, the PRISM reactor belongs to the class of small modular reactors. Beside using the reactor as a breeder reactor or for the transmutation of nuclear waste, it might also be used as a burner reactor for separated plutonium. This includes for example U.S.-American excess weapon-grade plutonium as well as separated reactor-grade plutonium. Recently, there has been an ongoing discussion in GB to use the PRISM reactor to dispose their excess civilian plutonium. Depending on the task, the core configuration varies slightly. We will present different layouts and the matching MCNP models, these models can then be used to conduct depletion calculations. From these results, analysis of the change in the plutonium isotopics in the spent fuel, the amount of fissioned plutonium, and the possible annual plutonium throughputs is possible.

  14. Chagas disease, a risk factor for high blood pressure.

    Science.gov (United States)

    Vicco, Miguel Hernán; Rodeles, Luz; Yódice, Agustina; Marcipar, Iván

    2014-12-01

    Chagas disease is a parasite infection caused by the protozoan Trypanosoma cruzi. Its most common complications is chronic Chagas heart disease but impairments of the systemic vasculature also has been observed. Although the different mechanisms that regulate blood pressure are disrupted, to our knowledge data on the association of hypertension and chronic Chagas disease are scarce. In this regard we evaluate whether Chagas disease constitutes a high blood pressure risk factor. We recruited 200 individuals, half of them with positive serology for T. cruzi. They were subjected to a complete clinical examination. The mean age of sampled individuals was 46.7 ± 12.3, and the mean of systolic and diastolic blood pressure were 124 ± 12 mmHg and 82 ± 10 mmHg, respectively. There were no between-group differences regarding age, sex distribution or body mass index. Chagas disease contributed significantly to high blood pressure (OR = 4, 95% CI 1.8323-7.0864, p = 0.0002). Our results reveal an important association between Chagas disease and high blood pressure, which should be contemplated by physicians in order to promote preventive cardiovascular actions in patients with Chagas disease.

  15. Chagas disease in Switzerland: history and challenges.

    Science.gov (United States)

    Jackson, Y; Chappuis, F

    2011-09-15

    Chagas disease, endemic in Latin America, is an emerging health problem in Europe affecting an estimated 80,000 persons. Around 60,000 Latin American migrants live in Switzerland, and cases of Chagas disease have been reported since 1979. As of June 2011, 258 cases have been diagnosed, mostly adults in the indeterminate phase of the chronic stage of the disease. Vertical transmission has been identified and there is a high potential for blood- and organ-borne transmission in the absence of systematic screening. Major challenges include (i) raising awareness among migrants and healthcare professionals, (ii) developing national protocols for screening and treatment targeting high-risk groups such as pregnant woman, newborns, migrants from highly endemic areas (e.g. Bolivia), and immunocompromised migrants, (iii) preventing blood- and organ-borne transmission by appropriate screening strategies, (iv) taking into account the social vulnerability of individuals at risk in the design and implementation of public health programmes, and (v) facilitating contacts with the communities at risk through outreach programmes, for example in churches and cultural groups.

  16. Enfermedad de Chagas o Tripanosomiasis Americana.

    Directory of Open Access Journals (Sweden)

    Felipe Guhl

    2000-08-01

    Full Text Available

    Situación Actual de Colombia.

    La enfermedad de Chagas o tripanosomiasis americana es una enfermedad parasitaria crónica causada por un protozoario flagelado el Trypanosoma cruzi, descrito por primera vez por Carlos Chagas, médico brasileño, a comienzos de este siglo y en su honor se denominó la enfermedad que lleva su nombre.

    Este parásito normalmente se transmite al ser humano a través de insectos triatomíneos estrictamente hematófagos de la familia Reduviidae, en el momento en que perforan la piel para succionar la sangre que los alimenta.

    Sin embargo, no se inocula directamente por intermedio de las estructuras bucales del insecto en el momento de la picadura como en el caso de las tripanosomiasis africanas, si no que se deposita pasivamente en la piel a través de las heces del insecto, penetrando en el cuerpo por la herida que causa la picadura u otras abrasiones de la piel o de la mucosa. El T. cruzi, también puede transmitirse por infección congénita, por transfusión de sangre contaminada o por el transplante de órganos contaminados. El ciclo vital del parásito es largo y complejo y su desarrollo tiene varias etapas, tanto en el vector triatomineo como en el huésped vertebrado .

    La Enfermedad de Chagas constituye una amenaza permanente para casi la cuarta parte de toda la población de América Latina. Si bien la enfermedad se encuentra presente en toda América Central y del Sur, sus manifestaciones y características epidemiológicas son altamente variables entre una y otra zona endémica. Existe una gran diversidad en las tasas de prevalencia, formas de transmisión, características parasitarias, patología clínica, vectores y reservorios.

    Más que cualquier otra enfermedad parasitaria, la enfermedad de Chagas se relaciona con el desarrollo económico y social de la población: los insectos triatomineos y las enfermedades que ellos transmiten existirán mientras en

  17. A Multi-disciplinary Overview of Chagas in Periurban Peru

    Directory of Open Access Journals (Sweden)

    Sarah McCune

    2010-04-01

    Full Text Available There are between 8 and 11 million cases of America Human Trypanosomiasis, commonly known as Chagas disease, in Latin America. Chagas is endemic in southern Peru, especially the Arequipa region, where it has expanded from poor, rural areas to periurban communities. This paper summarizes the findings of four studies in periurban Arequipa: on determinants of disease-vector infestation; on prevalence, spatial patterns, and risk factors of Chagas; on links between migration, settlement patterns, and disease-vector infestation; and on the relationship between discordant test results and spatially clustered transmission hotspots. These studies identified two risk factors associated with the disease: population dynamics and the urbanization of poverty. Understanding the disease within this new urban context will allow for improved public health prevention efforts and policy initiatives. Discovered in 1909 by Brazilian physician Carlos Chagas, American Human Trypanosomiasis is a chronic and potentially life-threatening illness found throughout Latin America (Moncayo, 2003. Indeed, it is estimated that there are between 8 and 11 million cases in Mexico and Central and South America (Centers for Disease Control [CDC], 2009. Chagas disease, as it is most commonly known, is endemic in southern Peru, especially in the region of Arequipa. Once thought to be limited to poor, rural areas, the disease is now appearing in the periurban communities that surround Arequipa City, the capital of the region (Cornejo del Carpio, 2003. Understanding the urbanization of Chagas disease will allow public health and medical professionals to better combat the further transmission of the disease. After providing an overview of Chagas and introducing the scope of the disease in Latin America, this paper will summarize the findings of four recent studies conducted in periurban districts in Arequipa. Ultimately, this paper seeks to identify the risk factors associated with Chagas

  18. Modeling laser brightness from cross Porro prism resonators

    Science.gov (United States)

    Forbes, Andrew; Burger, Liesl; Litvin, Igor Anatolievich

    2006-08-01

    Laser brightness is a parameter often used to compare high power laser beam delivery from various sources, and incorporates both the power contained in the particular mode, as well as the propagation of that mode through the beam quality factor, M2. In this study a cross Porro prism resonator is considered; crossed Porro prism resonators have been known for some time, but until recently have not been modeled as a complete physical optics system that allows the modal output to be determined as a function of the rotation angle of the prisms. In this paper we consider the diffraction losses as a function of the prism rotation angle relative to one another, and combine this with the propagation of the specific modes to determine the laser output brightness as a function of the prism orientation.

  19. Distance 2-Domination in Prisms of Graphs

    Directory of Open Access Journals (Sweden)

    Hurtado Ferran

    2017-05-01

    Full Text Available A set of vertices D of a graph G is a distance 2-dominating set of G if the distance between each vertex u ∊ (V (G − D and D is at most two. Let γ2(G denote the size of a smallest distance 2-dominating set of G. For any permutation π of the vertex set of G, the prism of G with respect to π is the graph πG obtained from G and a copy G′ of G by joining u ∊ V(G with v′ ∊ V(G′ if and only if v′ = π(u. If γ2(πG = γ2(G for any permutation π of V(G, then G is called a universal γ2-fixer. In this work we characterize the cycles and paths that are universal γ2-fixers.

  20. PENGUKURAN KINERJA UMKM MENGGUNAKAN PERFORMANCE PRISM

    Directory of Open Access Journals (Sweden)

    Cynthia Agelina Purnomo

    2017-10-01

    Full Text Available UMKM XYZ merupakan perusahaan yang bergerak di bidang pengolahan keripik buah nangka. Pada proses observasi langsung di lapangan, perusahaan mempunyai masalah dalam melakukan pengukuran kinerja. Pengukuran kinerja yang dilakukan hanya berdasarkan Net Profit Margin (rasio laba bersih dibandingkan dengan pendapatan tiap tahunnya. Pengukuran yang dilakukan oleh perusahaan tidak cukup representatif menilai kinerja perusahaan secara keseluruhan. Oleh karena itu, diperlukan alat ukur kinerja yang tepat dan fleksibel, yaitu dengan metode Performance Prism. Proses penentuan Key Performance Indicator (KPI kinerja berdasarkan persetujuan dari pihak manajer perusahaan. Dengan periode dasar (tahun 2015 didapatkan hasil bahwa terdapat 25 Key Performance Indicator yang terdiri dari: 2 KPI Investor, 8 KPI Konsumen, 4 KPI Suplier, 6 KPI Karyawan, dan 5 KPI Masyarakat Sekitar dengan nilai total kinerja keseluruhan sebagai pembanding dengan periode pengukuran adalah 2,232 (kategori cukup sehingga perlu ditingkatkan lagi pada periode selanjutnya berdasarkan saran-saran pada periode dasar.

  1. Acute Chagas disease in El Salvador 2000-2012 - Need for surveillance and control

    Directory of Open Access Journals (Sweden)

    Emi Sasagawa

    2014-04-01

    Full Text Available Several parasitological studies carried out in El Salvador between 2000-2012 showed a higher frequency of acute cases of Chagas disease than that in other Central American countries. There is an urgent need for improved Chagas disease surveillance and vector control programs in the provinces where acute Chagas disease occurs and throughout El Salvador as a whole.

  2. PRISM: Enmeshment of illness and self-schema.

    Science.gov (United States)

    Denton, Fiona; Sharpe, Louise; Schrieber, Leslie

    2004-01-01

    The Pictorial Representation of Illness and Self Measure (PRISM) is a recently developed tool purported to assess burden of suffering due to illness. The nature of the PRISM task suggests a conceptual link to the illness self-schema construct hypothesised to be present in some individuals with chronic illness. This study investigates the relationship between PRISM and schema as measured by cognitive bias. 43 patients with systemic lupus erythematosus (SLE) completed an information-processing task involving endorsement of positive and negative illness words as descriptors of themselves, followed by free recall of the words. The outcome measures were endorsement and recall bias for negative illness words. Patients also completed the PRISM task and were assessed on other physical and psychological variables. PRISM did not correlate significantly with age, depression, functional impairment or disease activity. In a multiple regression analysis, only recall bias made an independent contribution to PRISM. Illness self-schema appears to play a significant role in determining the way in which SLE patients complete the PRISM task. This is discussed in light of a schema enmeshment model recently proposed in the cognitive bias literature. Copyright 2004 S. Karger AG, Basel

  3. Spatial compression impairs prism-adaptation in healthy individuals

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    Rachel J Scriven

    2013-05-01

    Full Text Available Neglect patients typically present with gross inattention to one side of space following damage to the contralateral hemisphere. While prism-adaptation is effective in ameliorating some neglect behaviours, the mechanisms involved and their relationship to neglect remain unclear. Recent studies have shown that conscious strategic control processes in prism-adaptation may be impaired in neglect patients, who are also reported to show extraordinarily long aftereffects compared to healthy participants. Determining the underlying cause of these effects may be the key to understanding therapeutic benefits. Alternative accounts suggest that reduced strategic control might result from a failure to detect prism-induced reaching errors properly either because a the size of the error is underestimated in compressed visual space or b pathologically increased error detection thresholds reduce the requirement for error correction. The purpose of this study was to model these two alternatives in healthy participants and to examine whether strategic control and subsequent aftereffects were abnormal compared to standard prism adaptation. Each participant completed three prism-adaptation procedures within a MIRAGE mediated reality environment with direction errors recorded before, during and after adaptation. During prism-adaptation, visual-feedback of the reach could be compressed, perturbed by noise or represented veridically. Compressed visual space significantly reduced strategic control and aftereffects compared to control and noise conditions. These results support recent observations in neglect patients, suggesting that a distortion of spatial representation may successfully model neglect and explain neglect performance while adapting to prisms.

  4. Accuracy assessment of ALOS optical instruments: PRISM and AVNIR-2

    Science.gov (United States)

    Tadono, Takeo; Shimada, Masanobu; Iwata, Takanori; Takaku, Junichi; Kawamoto, Sachi

    2017-11-01

    This paper describes the updated results of calibration and validation to assess the accuracies for optical instruments onboard the Advanced Land Observing Satellite (ALOS, nicknamed "Daichi"), which was successfully launched on January 24th, 2006 and it is continuously operating very well. ALOS has an L-band Synthetic Aperture Radar called PALSAR and two optical instruments i.e. the Panchromatic Remotesensing Instrument for Stereo Mapping (PRISM) and the Advanced Visible and Near Infrared Radiometer type-2 (AVNIR-2). PRISM consists of three radiometers and is used to derive a digital surface model (DSM) with high spatial resolution that is an objective of the ALOS mission. Therefore, geometric calibration is important in generating a precise DSM with stereo pair images of PRISM. AVNIR-2 has four radiometric bands from blue to near infrared and uses for regional environment and disaster monitoring etc. The radiometric calibration and image quality evaluation are also important for AVNIR-2 as well as PRISM. This paper describes updated results of geometric calibration including geolocation determination accuracy evaluations of PRISM and AVNIR-2, image quality evaluation of PRISM, and validation of generated PRISM DSM. These works will be done during the ALOS mission life as an operational calibration to keep absolute accuracies of the standard products.

  5. Plant Reliability - an Integrated System for Management (PR-ISM)

    International Nuclear Information System (INIS)

    Aukeman, M.C.; Leininger, E.G.; Carr, P.

    1984-01-01

    The Toledo Edison Company, located in Toledo, Ohio, United States of America, recently implemented a comprehensive maintenance management information system for the Davis-Besse Nuclear Power Station. The system is called PR-ISM, meaning Plant Reliability - An Integrated System for Management. PR-ISM provides the tools needed by station management to effectively plan and control maintenance and other plant activities. The PR-ISM system as it exists today consists of four integrated computer applications: equipment data base maintenance, maintenance work order control, administrative activity tracking, and technical specification compliance. PR-ISM is designed as an integrated on-line system and incorporates strong human factors features. PR-ISM provides each responsible person information to do his job on a daily basis and to look ahead towards future events. It goes beyond 'after the fact' reporting. In this respect, PR-ISM is an 'interactive' control system which: captures work requirements and commitments as they are identified, provides accurate and up-to-date status immediately to those who need it, simplifies paperwork and reduces the associated time delays, provides the information base for work management and reliability analysis, and improves productivity by replacing clerical tasks and consolidating maintenance activities. The functional and technical features of PR-ISM, the experience of Toledo Edison during the first year of operation, and the factors which led to the success of the development project are highlighted. (author)

  6. Dynamic changes in brain activity during prism adaptation.

    Science.gov (United States)

    Luauté, Jacques; Schwartz, Sophie; Rossetti, Yves; Spiridon, Mona; Rode, Gilles; Boisson, Dominique; Vuilleumier, Patrik

    2009-01-07

    Prism adaptation does not only induce short-term sensorimotor plasticity, but also longer-term reorganization in the neural representation of space. We used event-related fMRI to study dynamic changes in brain activity during both early and prolonged exposure to visual prisms. Participants performed a pointing task before, during, and after prism exposure. Measures of trial-by-trial pointing errors and corrections allowed parametric analyses of brain activity as a function of performance. We show that during the earliest phase of prism exposure, anterior intraparietal sulcus was primarily implicated in error detection, whereas parieto-occipital sulcus was implicated in error correction. Cerebellum activity showed progressive increases during prism exposure, in accordance with a key role for spatial realignment. This time course further suggests that the cerebellum might promote neural changes in superior temporal cortex, which was selectively activated during the later phase of prism exposure and could mediate the effects of prism adaptation on cognitive spatial representations.

  7. Cardiomiopatía de Chagas.

    Directory of Open Access Journals (Sweden)

    Fernando Rosas A.

    2000-08-01

    Full Text Available

    La cardiomiopatía de Chagas es la causa más frecuente de cardiomiopatía en América Latina. Se constituye en la cuarta enfermedad parasitaria del continente, y es uno de los mayores problemas de salud pública en Colombia estimándose que existen 1.200.000 personas infectadas y que de éstos proba-blemente 25% desarrollaran una miocardiopatia crónica.

    En nuestro país pocas series clínicas han sido descritas, generalmente asociadas a falla cardíaca secundaria a una cardiomiopatía dilatada. El propósito de este trabajo es presentar una reseña histórica de la enfermedad en la que se incluyen los primeros trabajos clínicos desarrollados en nuestro medio. Así mismo, algunos aspectos de la fisiopatología y de la evolución clínica. Finalmente presentaremos la reciente experiencia acumulada en nuestro país en este campo por diferentes investigadores.

    Reseña Histórica
    En el año 1909 fue publicado el artículo original del Dr. Carlos Chagas, titulado “Nueva Trypanosomiasis Humana: estudios sobre la morfología y el ciclo evolutivo del Schizotrypanum Cruzi, agente etiológico de una nueva entidad mórbida en el hombre” (1. En él se describe como el Dr. Chagas, fue encomendado en 1907, por el Dr. Oswaldo Cruz (Director del instituto que posteriormente llevó su nombre, para ejecutar una campaña antipalúdica en los servicios de construcción de ferrocarriles en el norte del estado de Minas Gerais.

    En esa zona conoció la existencia de una hematófago denominado por los campesinos como “Barbeiro”, llamado así por que su picadura se localizaba usualmente en el rostro y era poco sintomática. El insecto habitaba en domicilios humanos, atacaba al hombre en la noche (después de apagar las luces, se ocultaba durante el día en las paredes y en los techos de las casas construidas en bahareque y paja. El hematófago fue identificado como perteneciente a la familia Reduviidae. Algunos de los

  8. Highly Effective Serodiagnosis for Chagas' Disease ▿

    Science.gov (United States)

    Hernández, Pilar; Heimann, Michael; Riera, Cristina; Solano, Marco; Santalla, José; Luquetti, Alejandro O.; Beck, Ewald

    2010-01-01

    Many proteins of Trypanosoma cruzi, the causative agent of Chagas' disease, contain characteristic arrays of highly repetitive immunogenic amino acid motifs. Diagnostic tests using these motifs in monomeric or dimeric form have proven to provide markedly improved specificity compared to conventional tests based on crude parasite extracts. However, in many cases the available tests still suffer from limited sensitivity. In this study we produced stable synthetic genes with maximal codon variability for the four diagnostic antigens, B13, CRA, TcD, and TcE, each containing between three and nine identical amino acid repeats. These genes were combined by linker sequences encoding short proline-rich peptides, giving rise to a 24-kDa fusion protein which was used as a novel diagnostic antigen in an enzyme-linked immunosorbent assay setup. Validation of the assay with a large number of well-characterized patient sera from Bolivia and Brazil revealed excellent diagnostic performance. The high sensitivity of the new test may allow future studies to use blood collected by finger prick and dried on filter paper, thus dramatically reducing the costs and effort for the detection of T. cruzi infection. PMID:20668136

  9. Behavioural biology of Chagas disease vectors.

    Science.gov (United States)

    Lazzari, Claudio Ricardo; Pereira, Marcos Horácio; Lorenzo, Marcelo Gustavo

    2013-01-01

    Many arthropod species have adopted vertebrate blood as their main food source. Blood is rich in nutrients and, except for the presence of parasites, sterile. However, this food source is not freely available, nor is obtaining it devoid of risk. It circulates inside vessels hidden underneath the skin of mobile hosts that are able to defend themselves and even predate the insects that try to feed on them. Thus, the haematophagous lifestyle is associated with major morphological, physiological and behavioural adaptations that have accumulated throughout the evolutionary history of the various lineages of blood-sucking arthropods. These adaptations have significant consequences for the evolution of parasites as well as for the epidemiology of vector-transmitted diseases. In this review article, we analyse various aspects of the behaviour of triatomine bugs to illustrate how each behavioural trait represents a particular adaptation to their close association with their hosts, which may easily turn into predators. Our aim is to offer to the reader an up-to-date integrative perspective on the behaviour of Chagas disease vectors and to propose new research avenues to encourage both young and experienced colleagues to explore this aspect of triatomine biology.

  10. Behavioural biology of Chagas disease vectors

    Directory of Open Access Journals (Sweden)

    Claudio Ricardo Lazzari

    2013-01-01

    Full Text Available Many arthropod species have adopted vertebrate blood as their main food source. Blood is rich in nutrients and, except for the presence of parasites, sterile. However, this food source is not freely available, nor is obtaining it devoid of risk. It circulates inside vessels hidden underneath the skin of mobile hosts that are able to defend themselves and even predate the insects that try to feed on them. Thus, the haematophagous lifestyle is associated with major morphological, physiological and behavioural adaptations that have accumulated throughout the evolutionary history of the various lineages of blood-sucking arthropods. These adaptations have significant consequences for the evolution of parasites as well as for the epidemiology of vector-transmitted diseases. In this review article, we analyse various aspects of the behaviour of triatomine bugs to illustrate how each behavioural trait represents a particular adaptation to their close association with their hosts, which may easily turn into predators. Our aim is to offer to the reader an up-to-date integrative perspective on the behaviour of Chagas disease vectors and to propose new research avenues to encourage both young and experienced colleagues to explore this aspect of triatomine biology.

  11. Recognizing Variable Environments The Theory of Cognitive Prism

    CERN Document Server

    Dong, Tiansi

    2012-01-01

    Normal adults do not have any difficulty in recognizing their homes. But can artificial systems do in the same way as humans? This book collects interdisciplinary evidences and presents an answer from the perspective of computing, namely, the theory of cognitive prism. To recognize an environment, an intelligent system only needs to classify objects, structures them based on the connection relation (not through measuring!), subjectively orders the objects, and compares with the target environment, whose knowledge is similarly structured. The intelligent system works, therefore, like a prism: when a beam of light (a scene) reaches (is perceived) to an optical prism (by an intelligent system), some light (objects) is reflected (are neglected), those passed through (the recognized objects) are distorted (are ordered differently). So comes the term 'cognitive prism'! Two fundamental propositions used in the theory can be informally stated as follow: an orientation relation is a kind of distance comparison relatio...

  12. Strongly-Refractive One-Dimensional Photonic Crystal Prisms

    Science.gov (United States)

    Ting, David Z. (Inventor)

    2004-01-01

    One-dimensional (1D) photonic crystal prisms can separate a beam of polychromatic electromagnetic waves into constituent wavelength components and can utilize unconventional refraction properties for wavelength dispersion over significant portions of an entire photonic band rather than just near the band edges outside the photonic band gaps. Using a ID photonic crystal simplifies the design and fabrication process and allows the use of larger feature sizes. The prism geometry broadens the useful wavelength range, enables better optical transmission, and exhibits angular dependence on wavelength with reduced non-linearity. The properties of the 1 D photonic crystal prism can be tuned by varying design parameters such as incidence angle, exit surface angle, and layer widths. The ID photonic crystal prism can be fabricated in a planar process, and can be used as optical integrated circuit elements.

  13. Negative index effects from a homogeneous positive index prism

    Science.gov (United States)

    Marcus, Sherman W.; Epstein, Ariel

    2017-12-01

    Cellular structured negative index metamaterials in the form of a right triangular prism have often been tested by observing the refraction of a beam across the prism hypotenuse which is serrated in order to conform to the cell walls. We show that not only can this negative index effect be obtained from a homogeneous dielectric prism having a positive index of refraction, but in addition, for sampling at the walls of the cellular structure, the phase in the material has the illusory appearance of moving in a negative direction. Although many previous reports relied on refraction direction and phase velocity of prism structures to verify negative index design, our investigation indicates that to unambiguously demonstrate material negativity additional empirical evidence is required.

  14. MEGARA Optics: stain removal in PBM2Y prisms

    International Nuclear Information System (INIS)

    Aguirre-Aguirre, D; Izazaga-Pérez, R; Carrasco, E; Villalobos-Mendoza, B; De Paz, A Gil; Gallego, J; Iglesias, J

    2017-01-01

    MEGARA is the new integral-field and multi-object optical spectrograph for the GTC. For medium and high resolution, the dispersive elements are volume phase holographic gratings, sandwiched between two flat windows and two prisms of high optical precision. The prisms are made of Ohara PBM2Y optical glass. After the prisms polishing process, some stains appeared on the surfaces. For this, in this work is shown the comparative study of five different products (muriatic acid, paint remover, sodium hydroxide, aqua regia and rare earth liquid polish) used for trying to eliminate the stains of the HR MEGARA prisms. It was found that by polishing with the hands the affected area, and using a towel like a kind of pad, and polish during five minutes using rare earth, the stains disappear completely affecting only a 5% the rms of the surface quality. Not so the use of the other products that did not show any apparent result. (paper)

  15. Prevalence of Chagas' Disease in Mulungu do Morro Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Roque Aras

    2002-05-01

    Full Text Available OBJECTIVE - The aim of this paper is to describe the prevalence of T. Cruzi infection in patients of from Mulungu do Morro, a rural tropical region of Northeastern Brazil. METHODS - A cross-sectional study was performed. After randomly selecting samples of the population, and obtaining their consents , patients completed pretested epidemiological and clinical questionnaires. Serum samples from all patients were collected and screened for the presence of T. cruzi antibodies. RESULTS - Of 694 patients examined, 174 patients (25.1% tested had a positive serology for Chagas' disease. Of the study population, 341 patients were male with 27% Chagas' disease prevalence, without a statistical difference. Illiteracy was the only variable related to T. cruzi infection in our population. CONCLUSION - In conclusion, our study points to the high prevalence of Chagas' disease among patients in Mulungu do Morro, suggesting that this region has a high frequency of infection and probably active vectorial transmission.

  16. Analysis of transverse field distributions in Porro prism resonators

    Science.gov (United States)

    Litvin, Igor A.; Burger, Liesl; Forbes, Andrew

    2007-05-01

    A model to describe the transverse field distribution of the output beam from porro prism resonators is proposed. The model allows the prediction of the output transverse field distribution by assuming that the main areas of loss are located at the apexes of the porro prisms. Experimental work on a particular system showed some interested correlations between the time domain behavior of the resonator and the transverse field output. These findings are presented and discussed.

  17. Beam pointing direction changes in a misaligned Porro prism resonator

    Science.gov (United States)

    Lee, Jyh-Fa; Leung, Chung-Yee

    1988-07-01

    The relative change of the beam pointing direction for a misaligned Porro prism resonator has been analyzed, using an oscillation axis concept for the Porro prism resonator to find the beam direction. Expressions for the beam tilting angles are presented which show that the angular misalignment in the horizontal direction will result in beam tilting in both the horizontal and vertical directions. Good agreement between experimental and theoretical results is found.

  18. The costs of preventing and treating chagas disease in Colombia.

    Directory of Open Access Journals (Sweden)

    Marianela Castillo-Riquelme

    Full Text Available The objective of this study is to report the costs of Chagas disease in Colombia, in terms of vector disease control programmes and the costs of providing care to chronic Chagas disease patients with cardiomyopathy.Data were collected from Colombia in 2004. A retrospective review of costs for vector control programmes carried out in rural areas included 3,084 houses surveyed for infestation with triatomine bugs and 3,305 houses sprayed with insecticide. A total of 63 patient records from 3 different hospitals were selected for a retrospective review of resource use. Consensus methodology with local experts was used to estimate care seeking behaviour and to complement observed data on utilisation.The mean cost per house per entomological survey was $4.4 (in US$ of 2004, whereas the mean cost of spraying a house with insecticide was $27. The main cost driver of spraying was the price of the insecticide, which varied greatly. Treatment of a chronic Chagas disease patient costs between $46.4 and $7,981 per year in Colombia, depending on severity and the level of care used. Combining cost and utilisation estimates the expected cost of treatment per patient-year is $1,028, whereas lifetime costs averaged $11,619 per patient. Chronic Chagas disease patients have limited access to healthcare, with an estimated 22% of patients never seeking care.Chagas disease is a preventable condition that affects mostly poor populations living in rural areas. The mean costs of surveying houses for infestation and spraying infested houses were low in comparison to other studies and in line with treatment costs. Care seeking behaviour and the type of insurance affiliation seem to play a role in the facilities and type of care that patients use, thus raising concerns about equitable access to care. Preventing Chagas disease in Colombia would be cost-effective and could contribute to prevent inequalities in health and healthcare.

  19. The modular ALMR (PRISM) fuel cycle

    International Nuclear Information System (INIS)

    Thompson, M.L.

    1990-01-01

    The modular reactor concept, PRISM (power reactor, innovative, small module), originated by General Electric in conjunction with the integral fast reactor (IFR) metal fuel being developed by Argonne National Laboratory (ANL), is the reference US Department of Energy advanced liquid-metal reactor (ALMR). The reference ALMR is unique in several ways; for example, it can produce (or breed) substantially more fissile material than it consumes. It is also unique in that it has the capability to utilize as fuel the long-life radioactive actinides (primarily plutonium, and the minor actinides, neptunium, americium, and curium) present as waste in light water reactor (LWR) spent fuels. This capability provides a means for converting long-life actinide radioactive wastes to elements whose lifetimes and thus storage needs are much shorter, namely, hundreds of years. This could clearly focus and potentially alleviate a controversial aspect (waste disposal) of the nuclear option. While it does not change the need for, or timing of, an initial high-level waste (HLW) repository, the conversion of actinides could change in a dramatic way the time period required for safe storage of nuclear waste and potentially the number and criteria for future repositories. This work considers the potential for utilizing LWR actinides in the ALMR fuel cycle

  20. APEX - the Hyperspectral ESA Airborne Prism Experiment

    Directory of Open Access Journals (Sweden)

    Koen Meuleman

    2008-10-01

    Full Text Available The airborne ESA-APEX (Airborne Prism Experiment hyperspectral mission simulator is described with its distinct specifications to provide high quality remote sensing data. The concept of an automatic calibration, performed in the Calibration Home Base (CHB by using the Control Test Master (CTM, the In-Flight Calibration facility (IFC, quality flagging (QF and specific processing in a dedicated Processing and Archiving Facility (PAF, and vicarious calibration experiments are presented. A preview on major applications and the corresponding development efforts to provide scientific data products up to level 2/3 to the user is presented for limnology, vegetation, aerosols, general classification routines and rapid mapping tasks. BRDF (Bidirectional Reflectance Distribution Function issues are discussed and the spectral database SPECCHIO (Spectral Input/Output introduced. The optical performance as well as the dedicated software utilities make APEX a state-of-the-art hyperspectral sensor, capable of (a satisfying the needs of several research communities and (b helping the understanding of the Earth’s complex mechanisms.

  1. Aspectos neurológicos da moléstia de chagas Neurological aspects of Chagas disease

    Directory of Open Access Journals (Sweden)

    Fritz Köberle

    1967-09-01

    Full Text Available Carlos Chagas related in more than two 200 cases, what he called "nervous forms" of trypanosomiasis, that is neurological manifestations from central origin (idiotism, infantilism, pseudo-bulbar paralysis, aphasia, cerebellar ataxia, atetosis, espostic or paralytic diplegia, disbasia. At that time Chagas expressed his concepts as follows: "In relation to the frequency of trypanosomiasis nervous forms we have performed many observations which allow us to state that this disease is the one which causes the largest number of organic affections of the central nervous system, in human pathology". We are plenty convinced by Chagas's statement. By experiments on animals of laboratory we have very often noticed a rather varied neurological symptomatology, being worth point out identical syndromes to those observed by Chagas. Our autopsy material non-rarely include chronic Chagas cases presenting a most varied symtomatology. Among them we have named only three cases of discerebral nanism, a rather rare affection in other parts of the world and relatively frequent in our material. The fact which we have demonstrated, i.e., a relatively great decreasing of number of nervous cells in the peripheral system could happen in the central nervous system as well. Provided that there are only two quantitative works on neuron number diminishing in the central nervous system in mice and rats we decline to go into further details about central neuropathies in man. We emphasized the necessity to perform researches on this field by means of intimate collaboration between clinicians and pathologists, as the only way to confirm on scientific basis all that was observed by the panoramic and genial vision of Carlos Chagas.

  2. The response to prism deviations in human infants.

    Science.gov (United States)

    Riddell, P M; Horwood, A M; Houston, S M; Turner, J E

    1999-09-23

    Previous research has suggested that infants are unable to make a corrective eye movement in response to a small base-out prism placed in front of one eye before 14-16 weeks [1]. Three hypotheses have been proposed to explain this early inability, and each of these makes different predictions for the time of onset of a response to a larger prism. The first proposes that infants have a 'degraded sensory capacity' and so require a larger retinal disparity (difference in the position of the image on the retina of each eye) to stimulate disparity detectors [2]. This predicts that infants might respond at an earlier age than previously reported [1] when tested using a larger prism. The second hypothesis proposes that infants learn to respond to larger retinal disparities through practice with small disparities [3]. According to this theory, using a larger prism will not result in developmentally earlier responses, and may even delay the response. The third hypothesis proposes that the ability to respond to prismatic deviation depends on maturational factors indicated by the onset of stereopsis (the ability to detect depth in an image on the basis of retinal disparity cues only) [4] [5], predicting that the size of the prism is irrelevant. To differentiate between these hypotheses, we tested 192 infants ranging from 2 to 52 weeks of age using a larger prism. Results showed that 63% of infants of 5-8 weeks of age produced a corrective eye movement in response to placement of a prism in front of the eye when in the dark. Both the percentage of infants who produced a response, and the speed of the response, increased with age. These results suggest that infants can make corrective eye movements in response to large prismatic deviations before 14-16 weeks of age. This, in combination with other recent results [6], discounts previous hypotheses.

  3. PRISM, Processing and Review Interface for Strong Motion Data Software

    Science.gov (United States)

    Kalkan, E.; Jones, J. M.; Stephens, C. D.; Ng, P.

    2016-12-01

    A continually increasing number of high-quality digital strong-motion records from stations of the National Strong Motion Project (NSMP) of the U.S. Geological Survey (USGS), as well as data from regional seismic networks within the U.S., calls for automated processing of strong-motion records with human review limited to selected significant or flagged records. The NSMP has developed the Processing and Review Interface for Strong Motion data (PRISM) software to meet this need. PRISM automates the processing of strong-motion records by providing batch-processing capabilities. The PRISM software is platform-independent (coded in Java), open-source, and does not depend on any closed-source or proprietary software. The software consists of two major components: a record processing engine composed of modules for each processing step, and a graphical user interface (GUI) for manual review and processing. To facilitate the use by non-NSMP earthquake engineers and scientists, PRISM (both its processing engine and GUI components) is easy to install and run as a stand-alone system on common operating systems such as Linux, OS X and Windows. PRISM was designed to be flexible and extensible in order to accommodate implementation of new processing techniques. Input to PRISM currently is limited to data files in the Consortium of Organizations for Strong-Motion Observation Systems (COSMOS) V0 format, so that all retrieved acceleration time series need to be converted to this format. Output products include COSMOS V1, V2 and V3 files as: (i) raw acceleration time series in physical units with mean removed (V1), (ii) baseline-corrected and filtered acceleration, velocity, and displacement time series (V2), and (iii) response spectra, Fourier amplitude spectra and common earthquake-engineering intensity measures (V3). A thorough description of the record processing features supported by PRISM is presented with examples and validation results. All computing features have been

  4. Doença de Chagas no Brasil Chagas disease in Brazil

    Directory of Open Access Journals (Sweden)

    Márcio C. Vinhaes

    2000-01-01

    Full Text Available Sumariam-se os dados da Fundação Nacional de Saúde (FNS sobre o estado atual dos vetores da doença de Chagas no Brasil, verificando-se que após vinte anos de controle químico continuado houve franca redução dos índices triatomínico-tripanosômicos, particularmente para esp��cies como Triatoma infestans e Panstrongylus megistus. Em paralelo, dados de sorologia escolar, de internações e de mortalidade pela doença indicam descenso nas taxas de incidência e impacto médico social da protozoose, restando áreas mais preocupantes, como o Nordeste e resíduos de T. infestans. Impõe-se urgente uma vigilância epidemiológica efetiva, a ser realizada por estados e municípios ante o processo de descentralização da FNS.This article presents the current situation for Chagas disease vectors in Brazil, based on data from the Brazilian National Health Foundation (FNS. Over the course of the last 20 years, continuous chemical control has resulted in a clear reduction of triatomine densities and Trypanosoma cruzi in Brazilian dwellings. Results have been particularly promising in relation to Triatoma infestans and Panstrongylus megistus, considered the most important species in the past. In parallel, data from school serological surveys, hospitalized patients, and mortality records show an important decrease in the disease. Nevertheless, some areas of the Brazilian Northeast and some residual foci of Triatoma infestans and Panstrongylus megistus remain as major challenges for public health authorities, requiring effective epidemiological surveillance. States and municipalities are required to assume this task at present, as the traditional Brazilian National Health Foundation is undergoing decentralization.

  5. Chagas Parasite Detection in Blood Images Using AdaBoost

    Directory of Open Access Journals (Sweden)

    Víctor Uc-Cetina

    2015-01-01

    Full Text Available The Chagas disease is a potentially life-threatening illness caused by the protozoan parasite, Trypanosoma cruzi. Visual detection of such parasite through microscopic inspection is a tedious and time-consuming task. In this paper, we provide an AdaBoost learning solution to the task of Chagas parasite detection in blood images. We give details of the algorithm and our experimental setup. With this method, we get 100% and 93.25% of sensitivity and specificity, respectively. A ROC comparison with the method most commonly used for the detection of malaria parasites based on support vector machines (SVM is also provided. Our experimental work shows mainly two things: (1 Chagas parasites can be detected automatically using machine learning methods with high accuracy and (2 AdaBoost + SVM provides better overall detection performance than AdaBoost or SVMs alone. Such results are the best ones known so far for the problem of automatic detection of Chagas parasites through the use of machine learning, computer vision, and image processing methods.

  6. Experimental Vaccines against Chagas Disease: A Journey through History.

    Science.gov (United States)

    Rodríguez-Morales, Olivia; Monteón-Padilla, Víctor; Carrillo-Sánchez, Silvia C; Rios-Castro, Martha; Martínez-Cruz, Mariana; Carabarin-Lima, Alejandro; Arce-Fonseca, Minerva

    2015-01-01

    Chagas disease, or American trypanosomiasis, which is caused by the protozoan parasite Trypanosoma cruzi, is primarily a vector disease endemic in 21 Latin American countries, including Mexico. Although many vector control programs have been implemented, T. cruzi has not been eradicated. The development of an anti-T. cruzi vaccine for prophylactic and therapeutic purposes may significantly contribute to the transmission control of Chagas disease. Immune protection against experimental infection with T. cruzi has been studied since the second decade of the last century, and many types of immunogens have been used subsequently, such as killed or attenuated parasites and new DNA vaccines. This primary prevention strategy appears feasible, effective, safe, and inexpensive, although problems remain. The objective of this review is to summarize the research efforts about the development of vaccines against Chagas disease worldwide. A thorough literature review was conducted by searching PubMed with the terms "Chagas disease" and "American trypanosomiasis" together with "vaccines" or "immunization". In addition, reports and journals not cited in PubMed were identified. Publications in English, Spanish, and Portuguese were reviewed.

  7. Chagas. From Exotic Tropical Disease to Pathology Globalized

    Directory of Open Access Journals (Sweden)

    Beatriz BASSO

    2016-09-01

    Full Text Available Chagas disease, whose aetiological agent is Trypanosoma cruzi, is one of the main endemic diseases in Latin America, ranking fourth regarding the number of lost life years due to death or disability in the area; nevertheless, it is among the so-called “neglected diseases”. Despite its rural origin, where it is transmitted through vector insects belonging to the Reduviidae family, it has nowadays also become a problem in urbanized areas and is becoming globalized through inter-human transmission, above all congenital, but also through transfusions and transplants. Chagas, a Hidden Affliction (Chagas, Un mal escondido, a documentary by Ricardo Preve, focuses on both aspects of the disease: the rural and the global one, including interviews with North American doctors and European researchers. A significant part of the film takes place in the USA, showing the worst consequence of the evolution of the disease, which is death by chagasic cardiopathy which, being a reality that takes place during filming, increases the sense of drama. In this paper we approach specific topics related to Chagas disease from a biomedical point of view, including comments related to the highlights of the film that are connected with such aspects. Towards the end, there is mention of the film Houses of Fire (Casas de fuego and of certain illustrative aspects concerning the life of Dr Salvador Mazza and the Argentine Mission of Regional Pathology Studies (MEPRA, topics that have already been dealt with in this. 

  8. Enfermedad de Chagas congenita en la Ciudad de Salta, Argentina Congenital Chagas' disease in Salta, Argentina

    Directory of Open Access Journals (Sweden)

    Mario Zaidenberg

    1993-02-01

    Full Text Available Se estudió la respuesta clínica y serológica a la infección chagásica de 937 embarazadas y sus 929 recién nacidos (RN vivos, grupo I; 4 RN de origen diverso, grupo II y 35 RN derivados de otros centros, grupo III. Las embarazadas se estudiaron con 3 reacciones serológicas; se definió infección cuando 2 o más reacciones eran positivas. En los RN el diagnóstico se confirmó por observación directa del T. cruzi en una muestra de sangre. Los RN con Chagas congénita (RN-ChC fueron tratados y seguidos con estudios clínicos y de laboratorio. Se detectaron 149 embarazadas chagásicas (15.9%, de las cuales se diagnosticaron 6 RN-ChC (4%. En el total de 968 RN estudiados se detectaron 12 RN infectados. El micro-hematócrito fue el método parasitológico de lectura rápida más efectivo para el diagnóstico de infección en nuestra serie. El par de reacciones serológicas específicas constituyó un criterio de mayor seguridad para el control y seguimiento de la infección congénita. Las expresiones clínicas más comunes de infección fueron hepatomegalia, esplenomegalia, ictericia, anemia y prematurez, con distintos grados de asociación. Se concluye que dadas las características clínicas de la enfermedad de Chagas congénita en nuestro medio, se impone como estrategia el diagnóstico serológico para la enfermedad de Chagas en todas las embarazadas y el control y seguimiento de sus RN hasta descartar o confirmar infección congénita.The immune response to Trypanosoma cruzi was studied in our hospital in 937 pregnant women (PW and their 929 newborns (NB, group I; 4 NB from this center not included in the first group, group II and 35 NB derived from other centers, group III. Two positive results among indirect hemagglutination (IHA, complement fixation (CF and indirect hemagglutination (IHA, complement fixation (CF and indirect immunofluorescence (IIF tests were considered as the criterion of previous infection with T. cruzi in PW. The

  9. Chagas disease: control, elimination and eradication. Is it possible?

    Directory of Open Access Journals (Sweden)

    Jose Rodrigues Coura

    2013-12-01

    Full Text Available From an epidemiological point of view, Chagas disease and its reservoirs and vectors can present the following characteristics: (i enzooty, maintained by wild animals and vectors, with broad occurrence from southern United States of America (USA to southern Argentina and Chile (42ºN 49ºS, (ii anthropozoonosis, when man invades the wild ecotope and becomes infected with Trypanosoma cruzi from wild animals or vectors or when the vectors and wild animals, especially marsupials, invade the human domicile and infect man, (iii zoonosis-amphixenosis and exchanged infection between animals and humans by domestic vectors in endemic areas and (iv zooanthroponosis, infection that is transmitted from man to animals, by means of domestic vectors, which is the rarest situation in areas endemic for Chagas disease. The characteristics of Chagas disease as an enzooty of wild animals and as an anthropozoonosis are seen most frequently in the Brazilian Amazon and in the Pan-Amazon region as a whole, where there are 33 species of six genera of wild animals: Marsupialia, Chiroptera, Rodentia, Edentata (Xenarthra, Carnivora and Primata and 27 species of triatomines, most of which infected with T. cruzi . These conditions place the resident populations of this area or its visitors - tourists, hunters, fishermen and especially the people whose livelihood involves plant extraction - at risk of being affected by Chagas disease. On the other hand, there has been an exponential increase in the acute cases of Chagas disease in that region through oral transmission of T. cruzi , causing outbreaks of the disease. In four seroepidemiological surveys that were carried out in areas of the microregion of the Negro River, state of Amazonas, in 1991, 1993, 1997 and 2010, we found large numbers of people who were serologically positive for T. cruzi infection. The majority of them and/or their relatives worked in piassava extraction and had come into contact with and were stung by

  10. Simulated Prism Therapy in Virtual Reality produces larger after-effects than standard prism exposure in normal healthy subject - Implications for Neglect Therapy

    DEFF Research Database (Denmark)

    Wilms, Inge Linda

    2018-01-01

    BACKGROUND: Virtual reality is an important area of exploration within computer-based cognitive rehabilitation of visual neglect. Virtual reality will allow for closer monitoring of patient behaviour during prism adaptation therapy and perhaps change the way we induce prismatic after......-effects. OBJECTIVE: This study compares the effect of two different prism simulation conditions in virtual reality to a standard exposure to prism goggles after one session of Prism Adaptation Therapy in healthy subjects. METHOD: 20 healthy subjects were subjected to one session of prism adaptation therapy under...... training for rehabilitation of hemi spatial attentional deficits such as visual neglect....

  11. Chagas disease: 100 years after its discovery. A systemic review.

    Science.gov (United States)

    Coura, José Rodrigues; Borges-Pereira, José

    2010-01-01

    Although Chagas disease was only discovered in 1909, it began millions of years ago as an enzootic disease among wild animals. Its transmission to man began accidentally as an anthropozoonosis when mankind invaded wild ecotopes. Endemic Chagas disease became established as a zoonosis over the last 200-300 years through deforestation for agriculture and livestock rearing and adaptation of triatomines to dwellings and to humans and domestic animals as food sources. When T. cruzi is transmitted to man, it invades the bloodstream and lymphatic system and lodges in muscle and heart tissue, the digestive system and phagocytic cells. Through this, it causes inflammatory lesions and an immune response, particularly mediated by CD4(+), CD8(+), IL2 and IL4, with cell and neuron destruction and fibrosis. These processes lead to blockage of the heart's conductive system, arrhythmias, heart failure, aperistalsis and dilatation of hollow viscera, especially the esophagus and colons. Chagas disease is characterized by an acute phase with or without symptoms, with (or more often without) T. cruzi penetration signs (inoculation chagoma or Romaña's sign), fever, adenomegaly, hepatosplenomegaly and patent parasitemia; and a chronic phase: indeterminate (asymptomatic, with normal electrocardiogram and heart, esophagus and colon X-rays) or cardiac, digestive or cardiac/digestive forms. There is great regional variation in the morbidity caused by Chagas disease: severe cardiac or digestive forms may occur in 10-50%, and indeterminate forms in the remaining, asymptomatic cases. The epidemiological and control characteristics of Chagas disease vary according to each country's ecological conditions and health policies. 2010. Published by Elsevier B.V.

  12. Containment performance of S-prism under severe BDB conditions

    International Nuclear Information System (INIS)

    Boardman, C.E.; Dubberley, A.E.; Hui, M.; Iwashige, K.

    2001-01-01

    S-PRISM is an advanced Fast Reactor plant design that utilizes compact modular pool-type reactors sized to enable factory fabrication and an affordable prototype test of a single Nuclear Steam Supply System (NSSS) for design certification at minimum cost and risk. Based on the success of the previous DOE sponsored Advanced Liquid Metal Reactor (ALMR) program GE has continued to develop and assess the technical viability and economic potential of an up-rated modular Fast Reactor called Super PRISM (S-PRISM). S-PRISM retains all of the key ALMR design features including passive reactor shutdown, passive shutdown heat removal, and passive reactor cavity cooling that were developed under an earlier DOE program. An additional feature of S-PRISM involves the use an innovative containment system that reduces the required design basis containment pressure by a factor of two through the use of a controlled venting system. The performance of this innovative containment system is evaluated and described in this paper. (author)

  13. Prism-based single-camera system for stereo display

    Science.gov (United States)

    Zhao, Yue; Cui, Xiaoyu; Wang, Zhiguo; Chen, Hongsheng; Fan, Heyu; Wu, Teresa

    2016-06-01

    This paper combines the prism and single camera and puts forward a method of stereo imaging with low cost. First of all, according to the principle of geometrical optics, we can deduce the relationship between the prism single-camera system and dual-camera system, and according to the principle of binocular vision we can deduce the relationship between binoculars and dual camera. Thus we can establish the relationship between the prism single-camera system and binoculars and get the positional relation of prism, camera, and object with the best effect of stereo display. Finally, using the active shutter stereo glasses of NVIDIA Company, we can realize the three-dimensional (3-D) display of the object. The experimental results show that the proposed approach can make use of the prism single-camera system to simulate the various observation manners of eyes. The stereo imaging system, which is designed by the method proposed by this paper, can restore the 3-D shape of the object being photographed factually.

  14. The Program for Regional and International Shorebird Monitoring (PRISM)

    Science.gov (United States)

    Bart, J.; Andres, B.; Brown, S.; Donaldson, G.; Harrington, B.; Johnston, V.; Jones, S.; Morrison, R.I.G.; Skagen, S.K.

    2005-01-01

    This report describes the "Program for Regional and International Shorebird Monitoring" (PRISM). PRISM is being implemented by a Canada-United States Shorebird Monitoring and Assessment Committee formed in 2001 by the Canadian Shorebird Working Group and the U.S. Shorebird Council. PRISM provides a single blueprint for implementing the shorebird conservation plans recently completed in Canada and the United States. The goals of PRISM are to (1) estimate the size of breeding population of 74 shorebird taxa in North America; (2) describe the distribution, abundance, and habitat relationships for each of these taxa; (3) monitor trends in shorebird population size; (4) monitor shorebird numbers at stopover locations, and; (5) assist local managers in meeting their shorebird conservation goals. PRISM has four main components: arctic and boreal breeding surveys, temperate breeding surveys, temperate non-breeding surveys, and neotropical surveys. Progress on, and action items for, each major component are described. The more important major tasks for immediate action are carrying out the northern surveys, conducting regional analyses to design the program of migration counts, and evaluating aerial photographic surveys for migration and winter counts.

  15. Reverse time migration of prism waves for salt flank delineation

    KAUST Repository

    Dai, Wei; Schuster, Gerard T.

    2013-01-01

    In this paper, we present a new reverse time migration method for imaging salt flanks with prism wave reflections. It consists of four steps: (1) migrating the seismic data with conventional RTM to give the RTM image; (2) using the RTM image as a reflectivity model to simulate source-side reflections with the Born approximation; (3) zero-lag correlation of the source-side reflection wavefields and receiver-side wavefields to produce the prism wave migration image; and (4) repeating steps 2 and 3 for the receiver-side reflections. An advantage of this method is that there is no need to pick the horizontal reflectors prior to migration of the prism waves. It also separately images the vertical structures at a different step to reduce crosstalk interference. The disadvantage of prism wave migration algorithm is that its computational cost is twice that of conventional RTM. The empirical results with a salt model suggest that prism wave migration can be an effective method for salt flank delineation in the absence of diving waves.

  16. Reverse time migration of prism waves for salt flank delineation

    KAUST Repository

    Dai, Wei

    2013-09-22

    In this paper, we present a new reverse time migration method for imaging salt flanks with prism wave reflections. It consists of four steps: (1) migrating the seismic data with conventional RTM to give the RTM image; (2) using the RTM image as a reflectivity model to simulate source-side reflections with the Born approximation; (3) zero-lag correlation of the source-side reflection wavefields and receiver-side wavefields to produce the prism wave migration image; and (4) repeating steps 2 and 3 for the receiver-side reflections. An advantage of this method is that there is no need to pick the horizontal reflectors prior to migration of the prism waves. It also separately images the vertical structures at a different step to reduce crosstalk interference. The disadvantage of prism wave migration algorithm is that its computational cost is twice that of conventional RTM. The empirical results with a salt model suggest that prism wave migration can be an effective method for salt flank delineation in the absence of diving waves.

  17. Quartz-Enhanced Photoacoustic Spectroscopy with Right-Angle Prism

    Directory of Open Access Journals (Sweden)

    Yongning Liu

    2016-02-01

    Full Text Available A right-angle prism was used to enhance the acoustic signal of a quartz-enhanced photoacoustic spectroscopy (QEPAS system. The incident laser beam was parallelly inverted by the right-angle prism and passed through the gap between two tuning fork prongs again to produce another acoustic excitation. Correspondingly, two pairs of rigid metal tubes were used as acoustic resonators with resonance enhancement factors of 16 and 12, respectively. The QEPAS signal was enhanced by a factor of 22.4 compared with the original signal, which was acquired without resonators or a prism. In addition, the system noise was reduced a little with double resonators due to the Q factor decrease. The signal-to-noise ratio (SNR was greatly improved. Additionally, a normalized noise equivalent absorption coefficient (NNEA of 5.8 × 10−8 W·cm−1·Hz−1/2 was achieved for water vapor detection in the atmosphere.

  18. PRISM: An innovative liquid metal fast breeder reactor

    International Nuclear Information System (INIS)

    Kruger, G.B.; Boardman, C.E.; Olich, E.E.; Switick, D.M.

    1986-01-01

    This paper describes an innovative sodium-cooled reactor concept employing small certified reactor modules coupled with a standardized steam generator system. The total plant employs nine PRISM reactors (power reactor inherently safe module) in three 415 MWe power blocks. The PRISM design concept utilizes inherent safety characteristics and modularity to improve licensability, reduce owner's risk, and reduce costs. The relatively small size of each reactor module facilitates the use of passive, inherent self-shutdown and shutdown heat removal features, which permit design simplification and reduction of safety-related systems. It is proposed that a single PRISM module be used in a full-scale integrated reactor safety test. Results from the test would be used to obtain NRC certification of the standard design

  19. Intricacies of Feedback in Computer-based Prism Adaptation Therapy

    DEFF Research Database (Denmark)

    Wilms, Inge Linda; Rytter, Hana Malá

    Prism Adaptation Therapy (PAT) is an intervention method for treatment of attentional disorders, such as neglect e.g. 1,2. The method involves repeated pointing at specified targets with or without prism glasses using a specifically designed wooden box. The aim of this study was to ascertain...... whether the PAT method can be executed with similar effect using a computer with a touch screen.   62 healthy subjects were subjected to two experimental conditions: 1) pointing out at targets using the original box, 2) pointing out at targets on a computer attached touch screen. In both conditions......, the subjects performed a pre-test consisting of 30 targets without feedback, then an exposure-test of 90 targets with prism glasses and feedback, and finally a post-test of 60 targets, with no glasses and no feedback. Two experiments were carried out, 1) the feedback was provided by showing a cross...

  20. Fungi & Health: can polysaccharides from the fungus inonotus obliquus (CHAGA) inhibit tumor growth?

    DEFF Research Database (Denmark)

    Wold, C. W.; Corthay, A.; Kjeldsen, Christian

    Inonotus obliquus (Chaga) – a white rot fungus found on birch trees in the northern hemisphere –has been used in traditional medicine in Europe and Asia for centuries. Native peoples have made use of Chaga by brewing it as a tea to treat gastro-intestinal problems, to heal wounds and even to treat...... cancer. The last few decades, studies have found Chaga to contain biologically active substances such as polysaccharides, triterpenoids, polyphenols and melanin. In vivo effects such as tumor growth inhibition have been observed in mice receiving various Chaga extracts. The main hypothesis behind...... the tumor inhibiting effect is two-fold: i) fungal polysaccharides may inhibit tumor growth indirectly by activating certain immune cells such as macrophages and ii) triterpenoids and other steroids from Chaga may give a direct cytotoxic effect against cancer cells. While triterpenoids from Chaga have been...

  1. A Highly Sensitive Rapid Diagnostic Test for Chagas Disease That Utilizes a Recombinant Trypanosoma cruzi Antigen

    Science.gov (United States)

    Barfield, C. A.; Barney, R. S.; Crudder, C. H.; Wilmoth, J. L.; Stevens, D. S.; Mora-Garcia, S.; Yanovsky, M. J.; Weigl, B. H.; Yanovsky, J.

    2011-01-01

    Improved diagnostic tests for Chagas disease are urgently needed. A new lateral flow rapid test for Chagas disease is under development at PATH, in collaboration with Laboratorio Lemos of Argentina, which utilizes a recombinant antigen for detection of antibodies to Trypanosoma cruzi. To evaluate the performance of this test, 375 earlier characterized serum specimens from a region where Chagas is endemic were tested using a reference test (the Ortho T. cruzi ELISA, Johnson & Johnson), a commercially available rapid test (Chagas STAT-PAK, Chembio), and the PATH–Lemos rapid test. Compared to the composite reference tests, the PATH–Lemos rapid test demonstrated an optimal sensitivity of 99.5% and specificity of 96.8%, while the Chagas STAT-PAK demonstrated a sensitivity of 95.3% and specificity of 99.5%. These results indicate that the PATH–Lemos rapid test shows promise as an improved and reliable tool for screening and diagnosis of Chagas disease. PMID:21342808

  2. O gênero Schizotrypanum Chagas, 1909

    Directory of Open Access Journals (Sweden)

    Emmanuel Dias

    1939-01-01

    Full Text Available No presente trabalho, em que foram analisados os caractéres de Schizotrypanum e consideradas suas relações com os de outros flagelados digenéticos, acreditamos ter ficado bem demonstrado que este gênero encontra sólidos fundamentos em que se baseie. Schizotrypanum possue caractéres morfológicos peculiares, que o aproximam de Leishmania no periodo de multiplicação e de Trypanosoma na fase sanguinea. Os flagelados pertencentes a esse gênero caracterisam-se não só pela morfologia da fórma de tripanosoma, como pela evolução no organismo do vertebrado. No S. cruzi, como no S. vespertilionis, a multiplicação se processa nos tecidos, constando da divisão binaria das formas intracelulares de leishmania; os tripanosomas sanguicolas não se multiplicam. Nenhum Trypanosoma apresenta no mamífero uma evolução morfológicamente e ecológicamente identica á de Schizotrypanum. S. cruzi aproxima-se dos tripanosomas patogenicos pela morfologia da fórma sanguicola e pela virulencia ás vezes mortal para o homem e diversos animais; deles se afasta entretanto pela evolução no inséto, modo de transmissão e facil cultivabilidade, caractéres biológicos estes que são comuns aos tripanosomas não patogenicos. Em nenhum dos grupos de tripanosomas póde o S. cruzi ser rigorosamente incluido, deles se distinguindo facilmente seja por sua morfologia, seja por sua biologia. O conjunto de caractéres próprios fundamenta perfeitamente a manutenção do gênero de Chagas, indicando-lhe como situação mais adequada, na classificação dos tripanosomídeos de mamíferos, o logar intermediario entre Leishmania e Trypanosoma. A separação do gênero Schizotrypanum é o melhor caso, quiça o unico justificado, dentre as numerosas tentativas para o desmembramento de Trypanosoma. Ela se impõe como medida compreensiva e util para a coordenação dos membros da complexa familia dos tripanosomideos e se justifica á luz dos mais exigentes crit

  3. Cerebellar inactivation impairs memory of learned prism gaze-reach calibrations.

    Science.gov (United States)

    Norris, Scott A; Hathaway, Emily N; Taylor, Jordan A; Thach, W Thomas

    2011-05-01

    Three monkeys performed a visually guided reach-touch task with and without laterally displacing prisms. The prisms offset the normally aligned gaze/reach and subsequent touch. Naive monkeys showed adaptation, such that on repeated prism trials the gaze-reach angle widened and touches hit nearer the target. On the first subsequent no-prism trial the monkeys exhibited an aftereffect, such that the widened gaze-reach angle persisted and touches missed the target in the direction opposite that of initial prism-induced error. After 20-30 days of training, monkeys showed long-term learning and storage of the prism gaze-reach calibration: they switched between prism and no-prism and touched the target on the first trials without adaptation or aftereffect. Injections of lidocaine into posterolateral cerebellar cortex or muscimol or lidocaine into dentate nucleus temporarily inactivated these structures. Immediately after injections into cortex or dentate, reaches were displaced in the direction of prism-displaced gaze, but no-prism reaches were relatively unimpaired. There was little or no adaptation on the day of injection. On days after injection, there was no adaptation and both prism and no-prism reaches were horizontally, and often vertically, displaced. A single permanent lesion (kainic acid) in the lateral dentate nucleus of one monkey immediately impaired only the learned prism gaze-reach calibration and in subsequent days disrupted both learning and performance. This effect persisted for the 18 days of observation, with little or no adaptation.

  4. Dobutamine Stress Echocardiography Safety in Chagas Disease Patients.

    Science.gov (United States)

    Rassi, Daniela do Carmo; Vieira, Marcelo Luiz Campos; Furtado, Rogerio Gomes; Turco, Fabio de Paula; Melato, Luciano Henrique; Hotta, Viviane Tiemi; Nunes, Colandy Godoy de Oliveira; Rassi, Luiz; Rassi, Salvador

    2017-02-01

    A few decades ago, patients with Chagas disease were predominantly rural workers, with a low risk profile for obstructive coronary artery disease (CAD). As urbanization has increased, they became exposed to the same risk factors for CAD of uninfected individuals. Dobutamine stress echocardiography (DSE) has proven to be an important tool in CAD diagnosis. Despite being a potentially arrhythmogenic method, it is safe for coronary patients without Chagas disease. For Chagas disease patients, however, the indication of DSE in clinical practice is uncertain, because of the arrhythmogenic potential of that heart disease. To assess DSE safety in Chagas disease patients with clinical suspicion of CAD, as well as the incidence of arrhythmias and adverse events during the exam. Retrospective analysis of a database of patients referred for DSE from May/2012 to February/2015. This study assessed 205 consecutive patients with Chagas disease suspected of having CAD. All of them had their serology for Chagas disease confirmed. Their mean age was 64±10 years and most patients were females (65.4%). No patient had significant adverse events, such as acute myocardial infarction, ventricular fibrillation, asystole, stroke, cardiac rupture and death. Regarding arrhythmias, ventricular extrasystoles occurred in 48% of patients, and non-sustained ventricular tachycardia in 7.3%. DSE proved to be safe in this population of Chagas disease patients, in which no potentially life-threatening outcome was found. Até poucas décadas atrás, os pacientes chagásicos eram predominantemente trabalhadores rurais, com baixo perfil de risco para doença obstrutiva coronária. Com a crescente urbanização, passaram a ter os mesmos fatores de risco para doença aterosclerótica que indivíduos não infectados. O ecocardiograma sob estresse com dobutamina (EED) é uma importante ferramenta no diagnóstico de coronariopatia. É referido, porém, como um método potencialmente arritmogênico, mas

  5. Modeling laser brightness from cross porro prism resonators

    CSIR Research Space (South Africa)

    Forbes, A

    2006-07-01

    Full Text Available , independent of the angle of incidence. Thus an initial planar wavefront remains planar after reflection. This property was initially exploited in Michelson interferometers to relax the tolerances on mis-alignment, and then proposed in 1962 by Gould et al1... 20 25 30 35 0 20 40 60 80 100 Prism Angle (Degrees) Nu mb er o f P et als divisions. These relationships lead to the following equation for the allowed angles of rotation of the prism edges relative to one another for repeatability...

  6. Petal–like modes in Porro prism resonators

    CSIR Research Space (South Africa)

    Litvin, IA

    2007-10-01

    Full Text Available , and then proposed in 1962 by Gould et al [1] as a means to overcome misalignment problems in optical resonators employing Fabry–Perot cavities by replacing the end face mirrors with crossed roof prisms. Lasers based on this principle have been developed over... of America OCIS codes: (140.4780) Optical resonators; (260.0260) Physical optics; (140.3410) Laser resonators; (230.5480) Prisms; (140.0140) Lasers and laser optics References and links 1. G. Gould, S. Jacobs, P. Rabinowitz and T. Shultz, “Crossed Roof...

  7. Assessment of prism responses to loss of flow events

    International Nuclear Information System (INIS)

    Slovik, G.C.; Van Tuyle, G.J.; Sands, S.

    1992-01-01

    The Nuclear Regulatory Commission (NRC), with Brookhaven national Laboratory providing technical support, is continuing a preapplication review of the 471 MWt, advanced liquid metal reactor (ALMR), PRISM by General Electric. The revised design has been evaluated using the SSC code, for a series of loss of flow events (LOF) with and without gas expansion modules (GEMs). These devices have a net worth of 69 cents and have reduced the seriousness of the LOF in PRISM. However, it was found that the extremely low probability case of an instantaneous loss of 4 EM pumps without scram could lead to sodium boiling even with the GEMs

  8. Anomalous refraction of light colors by a metamaterial prism.

    Science.gov (United States)

    Silveirinha, Mário G

    2009-05-15

    A prism of glass separates white light into its spectral components in such a manner that colors associated with shorter wavelengths are more refracted than the colors associated with longer wavelengths. Here, we demonstrate that this property is not universal, and that a lossless metamaterial prism with a suitable microstructure may enable a broadband regime of anomalous dispersion, where the spectral components of light are separated in an unconventional way, so that "violet light" is less refracted than "red light." This phenomenon is fundamentally different from conventional anomalous dispersion effects, which are invariably accompanied by significant loss and are typically very narrow band.

  9. Chagas disease, migration and community settlement patterns in Arequipa, Peru.

    Directory of Open Access Journals (Sweden)

    Angela M Bayer

    2009-12-01

    Full Text Available Chagas disease is one of the most important neglected tropical diseases in the Americas. Vectorborne transmission of Chagas disease has been historically rare in urban settings. However, in marginal communities near the city of Arequipa, Peru, urban transmission cycles have become established. We examined the history of migration and settlement patterns in these communities, and their connections to Chagas disease transmission.This was a qualitative study that employed focus group discussions and in-depth interviews. Five focus groups and 50 in-depth interviews were carried out with 94 community members from three shantytowns and two traditional towns near Arequipa, Peru. Focus groups utilized participatory methodologies to explore the community's mobility patterns and the historical and current presence of triatomine vectors. In-depth interviews based on event history calendars explored participants' migration patterns and experience with Chagas disease and vectors. Focus group data were analyzed using participatory analysis methodologies, and interview data were coded and analyzed using a grounded theory approach. Entomologic data were provided by an ongoing vector control campaign. We found that migrants to shantytowns in Arequipa were unlikely to have brought triatomines to the city upon arrival. Frequent seasonal moves, however, took shantytown residents to valleys surrounding Arequipa where vectors are prevalent. In addition, the pattern of settlement of shantytowns and the practice of raising domestic animals by residents creates a favorable environment for vector proliferation and dispersal. Finally, we uncovered a phenomenon of population loss and replacement by low-income migrants in one traditional town, which created the human settlement pattern of a new shantytown within this traditional community.The pattern of human migration is therefore an important underlying determinant of Chagas disease risk in and around Arequipa. Frequent

  10. A case of megacolon in Rio Grande Valley as a possible case of Chagas disease

    Directory of Open Access Journals (Sweden)

    Karl Reinhard

    2003-01-01

    Full Text Available We have been searching for evidence of Chagas disease in mummified human remains. Specifically, we have looked for evidence of alteration of intestinal or fecal morphology consistent with megacolon, a condition associated with Chagas disease. One prehistoric individual recovered from the Chihuahuan Desert near the Rio Grande exhibits such pathology. We present documentation of this case. We are certain that this individual presents a profoundly altered large intestinal tract and we suggest that further research should focus on confirmation of a diagnosis of Chagas disease. We propose that the prehistoric activity and dietary patterns in Chihuahua Desert hunter/gatherers promoted the pathoecology of Chagas disease.

  11. Interactive Media on Chagas Disease: Development and Content

    Directory of Open Access Journals (Sweden)

    Claudinei Caetano de Souza

    2013-10-01

    Full Text Available An interactive media on Chagas disease was developed as an educational tool, on the context of the scientific research and dissemination actions of the National Institute of Structural Biotechnology and Medicinal Chemistry in Infectious Diseases (INBEQMeDI. Different computational resources were used either in terms of hardware and software. The media contains 13 videos that range from 30 seconds to 4 minutes, all with information about Chagas disease, showing the social and economic aspects; the research made by the INBEQMeDI group; different aspects of the disease illustrated by slides arranged in a mobile carousel, and radio programs, with funny skits. The target audience for use of this feature is students aged 10 to 17 years. Teachers of areas of science and biology, through a partnership with the Agency of Education of the State of São Paulo, will be invited to plan a strategy for media use with their students.

  12. Characteristics of Fluid Force Reduction for Two Different Square Prisms in a Tandem Arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Ro, Ki Deok; Kang, Chang Whan; Park, Kwon Ho [Gyeongsang Nat’l Univ., Jinju (Korea, Republic of)

    2017-07-15

    The Characteristics of the flow fields of a square prism having a small square prism were investigated by measuring of lift and drag on the square prism and visualizing the flow field using PIV. The experimental parameters were the width ratios(H/B=0.2~0.6) of small square prisms to the prism width and the gap ratios (G/B=0~3) between the prism and the small square prism. The drag reduction rate of the square prism initially increased and then decreased with the G/B ratio for the same H/B ratio, and increased with the H/B ratio for the same G/B ratio. The maximum drag reduction rate of 98.0% was observed at H/B=0.6 and G/B=1.0. The lift reduction rate of the square prism was not affected by the width and gap ratios; the total average value was approximately 66.5%. In case of a square prism having a small square prism, the stagnation regions were represented in the upstream and downstream sides of the square prism.

  13. An assessment of the Crossed Porro Prism Resonator

    Science.gov (United States)

    See, B. A.; Fueloep, K.; Seymour, R.

    1980-08-01

    Lasers with crossed porro prism resonators for military laser rangefinder and designator applications are studied. Properties of these devices are reviewed and advantages over normal mirror resonators are examined. The theory of operating is treated and the mechanical stability and other features of the laser are examined and compared to standard mirror resonators.

  14. Stress effects in prism coupling measurements of thin polymer films

    NARCIS (Netherlands)

    Agan, S.; Ay, F.; Kocabas, A.; Aydinli, A.

    Due to the increasingly important role of some polymers in optical waveguide technologies, precise measurement of their optical properties has become important. Typically, prism coupling to slab waveguides made of materials of interest is used to measure the relevant optical parameters. However,

  15. Experience with basal area estimation by prisms in lodgepole pine.

    Science.gov (United States)

    James M. Trappe

    1957-01-01

    Estimation of basal area by prisms offers intriguing possibilities for reducing time and effort in making stand inventories. Increased inventory efficiency is a particular need in stands that are relatively low in value due to small stems, predominance of low value species or heavy defect. In the Pacific Northwest, lodgepole pine characteristically forms dense low-...

  16. A new ASE filter: the 20-fold prism monochromator

    NARCIS (Netherlands)

    Bakker, L.P.; Freriks, J.M.; Kroesen, G.M.W.

    1999-01-01

    A new ASE filter is presented, consisting of 20 dispersion prisms and two spatial filters. The transmission of the filter is measured with a ring-dye laser. The 1 width of the filter is 0.23 nm. The transmission is approximately 80% for the transmitted wavelengths. The rejection is in the order of .

  17. Prism adaptation for spatial neglect after stroke: translational practice gaps.

    Science.gov (United States)

    Barrett, A M; Goedert, Kelly M; Basso, Julia C

    2012-10-01

    Spatial neglect increases hospital morbidity and costs in around 50% of the 795,000 people per year in the USA who survive stroke, and an urgent need exists to reduce the care burden of this condition. However, effective acute treatment for neglect has been elusive. In this article, we review 48 studies of a treatment of intense neuroscience interest: prism adaptation training. Due to its effects on spatial motor 'aiming', prism adaptation training may act to reduce neglect-related disability. However, research failed, first, to suggest methods to identify the 50-75% of patients who respond to treatment; second, to measure short-term and long-term outcomes in both mechanism-specific and functionally valid ways; third, to confirm treatment utility during the critical first 8 weeks poststroke; and last, to base treatment protocols on systematic dose-response data. Thus, considerable investment in prism adaptation research has not yet touched the fundamentals needed for clinical implementation. We suggest improved standards and better spatial motor models for further research, so as to clarify when, how and for whom prism adaptation should be applied.

  18. Prism adaptation improves postural imbalance in neglect patients

    NARCIS (Netherlands)

    Nijboer, Tanja C W; Olthoff, Liselot; Van der Stigchel, Stefan; Visser-Meily, Johanna M a

    2014-01-01

    Several studies have found a negative relation between neglect and postural imbalance. The aim of the current study was to investigate the influence of a single session of prism adaptation on balance [i.e. mediolateral and anteroposterior center of pressure (CoP)] and postural sway (i.e. mean

  19. THz Photonic Band-Gap Prisms Fabricated by Fiber Drawing

    DEFF Research Database (Denmark)

    Busch, Stefan F.; Xu, Lipeng; Stecher, Matthias

    2012-01-01

    We suggest a novel form of polymeric based 3D photonic crystal prisms for THz frequencies which could be fabricated using a standard fiber drawing technique. The structures are modeled and designed using a finite element analyzing technique. Using this simulation software we theoretically study...

  20. Design of airborne imaging spectrometer based on curved prism

    Science.gov (United States)

    Nie, Yunfeng; Xiangli, Bin; Zhou, Jinsong; Wei, Xiaoxiao

    2011-11-01

    A novel moderate-resolution imaging spectrometer spreading from visible wavelength to near infrared wavelength range with a spectral resolution of 10 nm, which combines curved prisms with the Offner configuration, is introduced. Compared to conventional imaging spectrometers based on dispersive prism or diffractive grating, this design possesses characteristics of small size, compact structure, low mass as well as little spectral line curve (smile) and spectral band curve (keystone or frown). Besides, the usage of compound curved prisms with two or more different materials can greatly reduce the nonlinearity inevitably brought by prismatic dispersion. The utilization ratio of light radiation is much higher than imaging spectrometer of the same type based on combination of diffractive grating and concentric optics. In this paper, the Seidel aberration theory of curved prism and the optical principles of Offner configuration are illuminated firstly. Then the optical design layout of the spectrometer is presented, and the performance evaluation of this design, including spot diagram and MTF, is analyzed. To step further, several types of telescope matching this system are provided. This work provides an innovational perspective upon optical system design of airborne spectral imagers; therefore, it can offer theoretic guide for imaging spectrometer of the same kind.

  1. Antioxidant effect of Morus nigra on Chagas disease progression.

    Science.gov (United States)

    Montenote, Michelly Cristina; Wajsman, Vithor Zuccaro; Konno, Yoichi Takaki; Ferreira, Paulo César; Silva, Regildo Márcio Gonçalves; Therezo, Altino Luiz Silva; Silva, Luciana Pereira; Martins, Luciamáre Perinetti Alves

    2017-11-06

    Considering the widespread popular use of Morus nigra and the amount of scientific information on its antioxidant and anti-inflammatory activity, the effectiveness of this phytotherapeutic compound in the parasitemia progression during the acute phase of Chagas disease and its role in the development of the inflammatory process as well as its effects on the oxidative damage in the chronic phase of infection were evaluated. Thus, 96 male Swiss mice were randomly divided into eight groups, four groups were uninfected controls, and four groups were intraperitoneally infected with 5.0 x 104 blood trypomastigotes forms of T. cruzi QM2 strain. Four batches composed of one uninfected and one infected group were respectively treated with 70% alcohol solution and 25 μL, 50 μL and 75 μL of the phytotherapeutic compound. Levels of antioxidant elements (TBARS, FRAP, GSH and Sulfhydryl groups) were measured in plasma samples. The phytotherapeutic compound's antioxidant activity was measured by polyphenol and total flavonoid quantification, DPPH, NO, and FRAP method. Our results showed that the vehicle influenced some of the results that may have physiological relevance in Chagas disease. However, an important action of M. nigra tincture was observed in the progression of Chagas disease, since our results demonstrated a reduction in parasitemia of treated groups when compared to controls, especially in the group receiving 25 µL. However, in the chronic phase, the 50-µL dosage presented a better activity on some antioxidant defenses and minimized the tissue inflammatory process. Results indicated an important action of M. nigra tincture on the Chagas disease progression.

  2. Scrutinizing the Biomarkers for the Neglected Chagas Disease: How Remarkable!

    Science.gov (United States)

    Pinho, Rosa T; Waghabi, Mariana C; Cardillo, Fabíola; Mengel, José; Antas, Paulo R Z

    2016-01-01

    Biomarkers or biosignature profiles have become accessible over time in population-based studies for Chagas disease. Thus, the identification of consistent and reliable indicators of the diagnosis and prognosis of patients with heart failure might facilitate the prioritization of therapeutic management to those with the highest chance of contracting this disease. The purpose of this paper is to review the recent state and the upcoming trends in biomarkers for human Chagas disease. As an emerging concept, we propose a classification of biomarkers based on plasmatic-, phenotype-, antigenic-, genetic-, and management-related candidates. The available data revisited here reveal the lessons learned thus far and the existing challenges that still lie ahead to enable biomarkers to be employed consistently in risk evaluation for this disease. There is a strong need for biomarker validation, particularly for biomarkers that are specific to the clinical forms of Chagas disease. The current failure to achieve the eradication of the transmission of this disease has produced determination to solve this validation issue. Finally, it would be strategic to develop a wide variety of biomarkers and to test them in both preclinical and clinical trials.

  3. Opportunity cost for early treatment of Chagas disease in Mexico.

    Directory of Open Access Journals (Sweden)

    Janine M Ramsey

    2014-04-01

    Full Text Available BACKGROUND: Given current neglect for Chagas disease in public health programs in Mexico, future healthcare and economic development policies will need a more robust model to analyze costs and impacts of timely clinical attention of infected populations. METHODOLOGY/PRINCIPAL FINDINGS: A Markov decision model was constructed to simulate the natural history of a Chagas disease cohort in Mexico and to project the associated short and long-term clinical outcomes and corresponding costs. The lifetime cost for a timely diagnosed and treated Chagas disease patient is US$ 10,160, while the cost for an undiagnosed individual is US$ 11,877. The cost of a diagnosed and treated case increases 24-fold from early acute to indeterminate stage. The major cost component for lifetime cost was working days lost, between 44% and 75%, depending on the program scenario for timely diagnosis and treatment. CONCLUSIONS/SIGNIFICANCE: In the long term, it is cheaper to diagnose and treat chagasic patients early, instead of doing nothing. This finding by itself argues for the need to shift current policy, in order to prioritize and attend this neglected disease for the benefit of social and economic development, which implies including treatment drugs in the national formularies. Present results are even more relevant, if one considers that timely diagnosis and treatment can arrest clinical progression and enhance a chronic patient's quality of life.

  4. A Paratransgenic Strategy for the Control of Chagas Disease

    Directory of Open Access Journals (Sweden)

    Ivy Hurwitz

    2012-01-01

    Full Text Available Chagas disease results from infection with the parasite Trypanosoma cruzi. This disease remains a significant cause of morbidity and mortality in central and south America. Chagas disease now exists and is detected worldwide because of human migration. Control of Chagas disease has relied mainly on vector eradication however, the development of insect resistance to pesticides, coupled with cost and adverse health effects of insecticide treatments, has prompted our group to investigate novel methods of transmission control. Our laboratory has been instrumental in the development of the paratransgenic strategy to control vectorial transmission of T. cruzi. In this paper, we discuss various components of the paratransgenic approach. Specifically, we describe classes of molecules that can serve as effectors, including antimicrobial peptides, endoglucanases, and highly specific single chain antibodies that target surface glycoprotein tags on the surface of T. cruzi. Furthermore, we address evolving concepts related to field dispersal of engineered bacteria as part of the paratransgenic control strategy and attendant risk assessment evaluation.

  5. Opportunity cost for early treatment of Chagas disease in Mexico.

    Science.gov (United States)

    Ramsey, Janine M; Elizondo-Cano, Miguel; Sanchez-González, Gilberto; Peña-Nieves, Adriana; Figueroa-Lara, Alejandro

    2014-04-01

    Given current neglect for Chagas disease in public health programs in Mexico, future healthcare and economic development policies will need a more robust model to analyze costs and impacts of timely clinical attention of infected populations. A Markov decision model was constructed to simulate the natural history of a Chagas disease cohort in Mexico and to project the associated short and long-term clinical outcomes and corresponding costs. The lifetime cost for a timely diagnosed and treated Chagas disease patient is US$ 10,160, while the cost for an undiagnosed individual is US$ 11,877. The cost of a diagnosed and treated case increases 24-fold from early acute to indeterminate stage. The major cost component for lifetime cost was working days lost, between 44% and 75%, depending on the program scenario for timely diagnosis and treatment. In the long term, it is cheaper to diagnose and treat chagasic patients early, instead of doing nothing. This finding by itself argues for the need to shift current policy, in order to prioritize and attend this neglected disease for the benefit of social and economic development, which implies including treatment drugs in the national formularies. Present results are even more relevant, if one considers that timely diagnosis and treatment can arrest clinical progression and enhance a chronic patient's quality of life.

  6. Superconducting magnetic Wollaston prism for neutron spin encoding

    Energy Technology Data Exchange (ETDEWEB)

    Li, F., E-mail: fankli@indiana.edu; Parnell, S. R.; Wang, T.; Baxter, D. V. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Hamilton, W. A. [Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Maranville, B. B. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Semerad, R. [Ceraco Ceramic Coating GmbH, Ismaning 85737 (Germany); Cremer, J. T. [Adelphi Technology Inc., Redwood City, California 94063 (United States); Pynn, R. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)

    2014-05-15

    A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS) materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ∼30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ∼98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm × 30 mm) and an increase in length scales accessible to SESAME to beyond 10 μm. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.

  7. Superconducting magnetic Wollaston prism for neutron spin encoding

    Science.gov (United States)

    Li, F.; Parnell, S. R.; Hamilton, W. A.; Maranville, B. B.; Wang, T.; Semerad, R.; Baxter, D. V.; Cremer, J. T.; Pynn, R.

    2014-05-01

    A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS) materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ˜30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ˜98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm × 30 mm) and an increase in length scales accessible to SESAME to beyond 10 μm. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.

  8. Survey of Pediatric Infectious Diseases Society Members About Congenital Chagas Disease.

    Science.gov (United States)

    Edwards, Morven S; Abanyie, Francisca A; Montgomery, Susan P

    2018-01-01

    Participants in a survey about congenital Chagas disease, distributed electronically to Pediatric Infectious Diseases Society members, perceived having limited knowledge about congenital Trypanosoma cruzi infection. Most rarely or never consider the diagnosis in infants born to parents from Latin America. Improved awareness of congenital Chagas disease and assessment of at-risk infants is needed.

  9. Prevention of congenital Chagas disease by Benznidazole treatment in reproductive-age women. An observational study.

    Science.gov (United States)

    Álvarez, María G; Vigliano, Carlos; Lococo, Bruno; Bertocchi, Graciela; Viotti, Rodolfo

    2017-10-01

    Since the decline in new cases of infection by insect/vector, congenital Chagas disease has become more relevant in the transmission of Chagas disease. Treatment with benznidazole significantly reduces the parasitemia, which constitutes an important factor linked to vertical transmission. The objective of this study was to evaluate whether treatment with benznidazole previously administered to women of childbearing age can prevent or reduce the incidence of new cases of congenital Chagas disease. An historical cohort study that included all women in reproductive age (15-45 years) assisted in our center was designed. We included 67 mothers with chronic Chagas disease; 35 women had not been treated prior to pregnancy, 15 had been treated prior to pregnancy and 17 gave birth prior and after treatment with benznidazole. Eight mothers gave birth to 16 children with congenital Chagas disease (8/67, 12%). The prevalence of congenital Chagas was 16/114 (14%) children born to untreated mothers and 0/42 (0%) children born to benznidazole- treated mothers, p=0.01. No significant differences were observed in clinical, serologic, epidemiological or socioeconomic baseline variables between mothers with and without children born with congenital Chagas. A 32% conversion rate to negative serology was observed in benznidazole-treated women after long-term follow up. Antiparasitic treatment administered to women in reproductive age can prevent the occurrence of congenital Chagas disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The effect of compliant prisms on subduction zone earthquakes and tsunamis

    Science.gov (United States)

    Lotto, Gabriel C.; Dunham, Eric M.; Jeppson, Tamara N.; Tobin, Harold J.

    2017-01-01

    Earthquakes generate tsunamis by coseismically deforming the seafloor, and that deformation is largely controlled by the shallow rupture process. Therefore, in order to better understand how earthquakes generate tsunamis, one must consider the material structure and frictional properties of the shallowest part of the subduction zone, where ruptures often encounter compliant sedimentary prisms. Compliant prisms have been associated with enhanced shallow slip, seafloor deformation, and tsunami heights, particularly in the context of tsunami earthquakes. To rigorously quantify the role compliant prisms play in generating tsunamis, we perform a series of numerical simulations that directly couple dynamic rupture on a dipping thrust fault to the elastodynamic response of the Earth and the acoustic response of the ocean. Gravity is included in our simulations in the context of a linearized Eulerian description of the ocean, which allows us to model tsunami generation and propagation, including dispersion and related nonhydrostatic effects. Our simulations span a three-dimensional parameter space of prism size, prism compliance, and sub-prism friction - specifically, the rate-and-state parameter b - a that determines velocity-weakening or velocity-strengthening behavior. We find that compliant prisms generally slow rupture velocity and, for larger prisms, generate tsunamis more efficiently than subduction zones without prisms. In most but not all cases, larger, more compliant prisms cause greater amounts of shallow slip and larger tsunamis. Furthermore, shallow friction is also quite important in determining overall slip; increasing sub-prism b - a enhances slip everywhere along the fault. Counterintuitively, we find that in simulations with large prisms and velocity-strengthening friction at the base of the prism, increasing prism compliance reduces rather than enhances shallow slip and tsunami wave height.

  11. Suffering Quantified? Feasibility and Psychometric Characteristics of 2 Revised Versions of the Pictorial Representation of Illness and Self Measure (PRISM)

    NARCIS (Netherlands)

    PhD Ad J.J.M. Vingerhoets; PhD Marjet G.B.G. Blokhorst; MSc Jolene L.M. Reimus; MSc Annemieke M.A. van Nunen; MD E.J.M. Wouters

    2008-01-01

    The Pictorial Representation of Illness and Self Measure (PRISM) assesses suffering. In this article, the authors explored the feasibility and psychometric qualities of 2 revised versions of the PRISM-PRISM-R1 and PRISM-R2-that they used in 3 studies of participants with different medical problems.

  12. Challenges in the management of Chagas disease in Latin-American migrants in Europe.

    Science.gov (United States)

    Monge-Maillo, B; López-Vélez, R

    2017-05-01

    Chagas disease is endemic in Latin America. Due to migration the infection has crossed borders and it is estimated that 68,000-120,000 people with Chagas disease are currently living in Europe and 30% of them may develop visceral involvement. However, up to 90% of Chagas disease cases in Europe remain undiagnosed. The challenges which have to be overcome in Chagas disease in non-endemic countries are focused on related downing barriers to health care access, and related to screening, diagnostic tools and therapeutic management. The aim of this review is to highlight how healthcare management for Latin American migrants with Chagas disease in Europe may be improved. Medical literature was searched using PubMed. No limits were placed with respect to the language or date of publication although most of the articles selected were articles published in the last five years. Chosen search terms were "Chagas disease" AND ("migrants" OR "screening" OR "transmission" OR "treatment"; OR "knowledge" OR "non-endemic countries"); migrants AND ("Public health" OR "Health Service Accessibility" OR "Delivery of Health care"); and "Congenital Chagas disease". Healthcare management of migrant populations with Chagas disease in Europe has to be improved: -Surveillance programmes are needed to measure the burden of the disease; -screening programmes are needed; -administrative and cultural barriers in the access to health care for migrants should be reduced; -education programmes on Chagas disease should be performed -research on new diagnostic tools and therapeutic options are required. This review highlights the needs of profound changes in the health care of Latin American migrants with Chagas disease in Europe. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  13. Chagas Disease: Challenges in Developing New Trypanocidal Lead Compounds [Doença de Chagas: Desafios no Desenvolvimento de Novas Substâncias Líderes Tripanomicidas

    OpenAIRE

    Fernando de C. da Silva; Sabrina B. Ferreira; David R. da Rocha; Vitor F. Ferreira

    2012-01-01

    Chagas disease cycle was fully elucidated by Carlos Chagas in 1909, when he reported his discovery to the scientific community in two seminal papers. Today remains innumerous factors that limit its therapeutic treatment. One of them is the lack of new drugs in the market since is well known that the existing drugs are poorly active with low efficacy and considerable side effects. Nowadays, many efforts have been done in combinatorial chemistry and synthesis of new compounds searching for new ...

  14. Characteristic analysis of a polarization output coupling Porro prism resonator

    Science.gov (United States)

    Yang, Hailong; Meng, Junqing; Chen, Weibiao

    2015-02-01

    An Electro-optical Q-switched Nd:YAG slab laser with a crossed misalignment Porro prism resonator for space applications has been theoretically and experimentally investigated. The phase shift induced by the combination of different wave plates and Porro prism azimuth angles have been studied for creating high loss condition prior to Q-switching. The relationship of the effective output coupling reflectivity and the employed Q-switch driving voltage is explored by using Jones matrix optics. In the experiment, the maximum output pulse energy of 93 mJ with 14-ns pulse duration is obtained at the repetition rate of 20 Hz and the optical-to-optical conversion efficiency is 16.8%. The beam quality factors are M 2 x = 2.5 and M 2y = 2.2, respectively.

  15. Train integrity detection risk analysis based on PRISM

    Science.gov (United States)

    Wen, Yuan

    2018-04-01

    GNSS based Train Integrity Monitoring System (TIMS) is an effective and low-cost detection scheme for train integrity detection. However, as an external auxiliary system of CTCS, GNSS may be influenced by external environments, such as uncertainty of wireless communication channels, which may lead to the failure of communication and positioning. In order to guarantee the reliability and safety of train operation, a risk analysis method of train integrity detection based on PRISM is proposed in this article. First, we analyze the risk factors (in GNSS communication process and the on-board communication process) and model them. Then, we evaluate the performance of the model in PRISM based on the field data. Finally, we discuss how these risk factors influence the train integrity detection process.

  16. Transient safety performance of the PRISM innovative liquid metal reactor

    International Nuclear Information System (INIS)

    Magee, P.M.; Dubberley, A.E.; Rhow, S.K.; Wu, T.

    1988-01-01

    The PRISM sodium-cooled reactor concept utilizes passive safety characteristics and modularity to increase performance margins, improve licensability, reduce owner's risk and reduce costs. The relatively small size of each reactor module (471 MWt) facilitates the use of passive self-shutdown and shutdown heat removal features, which permit design simplification and reduction of safety-related systems. Key to the transient performance is the inherent negative reactivity feedback characteristics of the core design resulting from the use of metal (U-Pu-Zr) swing, and very low control rod runout worth. Selected beyond design basis events relying only on these core design features are analyzed and the design margins summarized to demonstrate the advancement in reactor safety achieved with the PRISM design concept

  17. Optofluidic laser scanner based on a rotating liquid prism.

    Science.gov (United States)

    Kopp, Daniel; Lehmann, Lukas; Zappe, Hans

    2016-03-20

    We demonstrate an electrowetting-actuated optofluidic system based on a rotatable liquid prism implemented as a two-dimensional laser scanner. The system is fabricated through a novel technology using a patterned flexible polymeric foil on which a high density of electrodes is structured and which is subsequently inserted into a cylindrical housing. The resulting radial electrode array is used for electrowetting actuation of two fluids filled into the cylinder, which allows a controllable tilt and orientation of the planar liquid interface and thus represents a tunable rotating prism. Finite element simulations and subsequent experimental verification show that this highly planar and precisely positionable liquid/liquid interface may be actuated to a deflection angle of ±6.4°, with a standard deviation of ±0.18°, and rotated 360° about the vertical axis. Power consumption is limited to several microwatts, and switching times of several hundred milliseconds were determined.

  18. Design of partially optically stable reflector systems and prisms

    Science.gov (United States)

    Tsai, Chuang-Yu

    2010-09-01

    The characteristics and design method of the total optically stable (TOS) reflector systems/prisms were introduced in an early paper (Tsai and Lin in Appl. Opt. 47:4158-4163, 2008), where only two types of TOS reflector system exist, namely preservation or retroreflection. In this paper, we introduce the partially optically stable (POS) reflector system, which is only optically stable about a specific directional vector; nevertheless, the exiting light ray is not restricted to preservation or retroreflection. The proposed paper also presents an analytic method for the design of POS reflector systems comprised of multiple reflectors. Furthermore, it is shown that a POS prism can be obtained by adding two refracting flat boundary surfaces with specific conditions at the entrance and exit positions of the light ray in an optical system with multiple reflectors.

  19. Hyperbolic prisms and foams in Hele-Shaw cells

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail: tufaile@usp.br [Soft Matter Laboratory, Escola de Artes, Ciencias e Humanidades, Universidade de Sao Paulo, 03828-000, Sao Paulo (Brazil); Tufaile, A.P.B. [Soft Matter Laboratory, Escola de Artes, Ciencias e Humanidades, Universidade de Sao Paulo, 03828-000, Sao Paulo (Brazil)

    2011-10-03

    The propagation of light in foams creates patterns which are generated due to the reflection and refraction of light. One of these patterns is observed by the formation of multiple mirror images inside liquid bridges in a layer of bubbles in a Hele-Shaw cell. We are presenting the existence of these patterns in foams and their relation with hyperbolic geometry and Sierpinski gaskets using the Poincare disk model. The images obtained from the experiment in foams are compared to the case of hyperbolic optical elements. -- Highlights: → The chaotic scattering of light in foams generating deltoid patterns is based on hyperbolic geometry. → The deltoid patterns are obtained through the Plateau borders in a Hele-Shaw cell. → The Plateau borders act like hyperbolic prism. → Some effects of the refraction and reflection of the light rays were studied using a hyperbolic prism.

  20. Prism therapy and visual rehabilitation in homonymous visual field loss.

    LENUS (Irish Health Repository)

    O'Neill, Evelyn C

    2012-02-01

    PURPOSE: Homonymous visual field defects (HVFD) are common and frequently occur after cerebrovascular accidents. They significantly impair visual function and cause disability particularly with regard to visual exploration. The purpose of this study was to assess a novel interventional treatment of monocular prism therapy on visual functioning in patients with HVFD of varied etiology using vision targeted, health-related quality of life (QOL) questionnaires. Our secondary aim was to confirm monocular and binocular visual field expansion pre- and posttreatment. METHODS: Twelve patients with acquired, documented HVFD were eligible to be included. All patients underwent specific vision-targeted, health-related QOL questionnaire and monocular and binocular Goldmann perimetry before commencing prism therapy. Patients were fitted with monocular prisms on the side of the HVFD with the base-in the direction of the field defect creating a peripheral optical exotropia and field expansion. After the treatment period, QOL questionnaires and perimetry were repeated. RESULTS: Twelve patients were included in the treatment group, 10 of whom were included in data analysis. Overall, there was significant improvement within multiple vision-related, QOL functioning parameters, specifically within the domains of general health (p < 0.01), general vision (p < 0.05), distance vision (p < 0.01), peripheral vision (p < 0.05), role difficulties (p < 0.05), dependency (p < 0.05), and social functioning (p < 0.05). Visual field expansion was shown when measured monocularly and binocularly during the study period in comparison with pretreatment baselines. CONCLUSIONS: Patients with HVFD demonstrate decreased QOL. Monocular sector prisms can improve the QOL and expand the visual field in these patients.

  1. Prism therapy and visual rehabilitation in homonymous visual field loss.

    LENUS (Irish Health Repository)

    O'Neill, Evelyn C

    2011-02-01

    Homonymous visual field defects (HVFD) are common and frequently occur after cerebrovascular accidents. They significantly impair visual function and cause disability particularly with regard to visual exploration. The purpose of this study was to assess a novel interventional treatment of monocular prism therapy on visual functioning in patients with HVFD of varied etiology using vision targeted, health-related quality of life (QOL) questionnaires. Our secondary aim was to confirm monocular and binocular visual field expansion pre- and posttreatment.

  2. Innovative Solar Tracking Concept by Rotating Prism Array

    Directory of Open Access Journals (Sweden)

    Héctor García

    2014-01-01

    Full Text Available Solar energy has become one of the most promising renewable energies and is the most widely used nowadays. In order to achieve an optimum performance, both photovoltaic and solar thermal applications are required to track the position of the sun throughout the day and year in the most effective way possible to avoid a high negative impact on the system efficiency. The present paper attempts to describe a novel semipassive solar tracking concentrator (SPSTC in which, in order to track the sun, two independent arrays of polymethyl methacrylate (PMMA prisms are implemented to refract sunlight by rotating said prisms, thus being able to redirect solar radiation as desired. The first set is responsible for eliminating one of the directional components of the solar radiation; the task is achieved by rotating the prisms within the array at a specific angle. The second set deals with another of the sunlight’s directional components, transforming its direction into a completely perpendicular pattern to the array. Having downward vertical radiation makes it possible to implement a stationary Fresnel lens to concentrate the solar radiation for any application desired. The system is designed and validated using simulation software to prove the feasibility of the concept.

  3. Increased osmotic sensitivity for antidiuretic response in chronic chagas' disease

    Directory of Open Access Journals (Sweden)

    Joel Paulo Russomano Veiga

    1985-06-01

    Full Text Available The osmotic threshold for attaining the antidiuretic response to hypertonic saline infusion and Progressive dehydration was studied in 31 patients with the chronic form of Chagas' disease and 16 control patients. The chagasic patients exhibited enhanced osmoticsensitivity to the antidiuretic response. This was demonstrated by lower values of the increments in plasma osmolarity sufficient to induce a significant fall in water clearance, without alterations in the osmolar clearance or creatinine excretion. The time needed to attain the antidiuretic response was shorterfor chagasics in relation to normal subjects. The results suggest the existence of a disturbance in the fine control of osmoregulation in the chagasic patients. They are interpreted to be a consequence of the denervation in hypothalamic or extrahypothalamic areas that regulate the secretion of vasopressin in chronic Chagas' disease.O limiar de sensibilidade osmótíca para obtenção de resposta antídiurética foi avaliado em 31 pacientes com a forma crônica da moléstia de Chagas, através de infusão de salina hipertônica ou desidratação. Os resultados, quando comparados com os obtidos em 16 pacientes-controle, mostram uma sensibilidade osmótíca aumentada para os chagásicos, dados os menores valores do incremento na osmolaridade plasmática, suficiente para induzir uma queda significativa na depuração de água livre, sem alterações na depuração osmolar ou na excreção de creatínina. Também, o tempo necessário para atingir a antídiurese foi mais curto para os chagásicos do que para os controles. Os resultados sugerem a existência de um distúrbio na osmorregulação, nos pacientes chagásicos, caracterizado por uma sensibilidade osmótíca aumentada dos osmorreceptores para liberação da vasopressina. Estes dados interpretam-se como conseqüente à desnervação em áreas hipotalâmicas ou extra-hipotalâmicas, relacionadas com a secreção do horm

  4. New Scenarios of Chagas Disease Transmission in Northern Colombia

    Directory of Open Access Journals (Sweden)

    Catalina Tovar Acero

    2017-01-01

    Full Text Available Chagas disease (CD is a systemic parasitic infection caused by the flagellated form of Trypanosoma cruzi. Córdoba department, located in the Colombian Caribbean Coast, was not considered as a region at risk of T. cruzi transmission. In this article, we describe the first acute CD case in Salitral village in Sahagún, Córdoba, confirmed by microscopy and serological tests. Our results draw attention to a new scenario of transmission of acute CD in nonendemic areas of Colombia and highlight the need to include CD in the differential diagnosis of febrile syndromes in this region.

  5. Local Seismicity Recorded by ChilePEPPER: Implications for Dynamic Accretionary Prism Response and Long-term Prism Evolution

    Science.gov (United States)

    de Moor, A.; Trehu, A. M.; Tryon, M. D.

    2015-12-01

    To investigate the dynamic response of the outer accretionary wedge updip from the patch of greatest slip during the Mw8.8 2010 Maule earthquake, 10 Ocean Bottom Seismometers (OBS) were deployed from May 2012 to March 2013 in a small array with an inter-instrument spacing of ~12 km . Nine instruments were recovered, with 4 recording data on 3 intermediate-band 3-component seismometers and a differential pressure gauge and 5 recording data from absolute pressure gauges. [note: All instruments were also equipped with a fluid flow meter sensitive to flow rates as low as 0.0001 cm/yr in or out of the sediments. However, no flow signal was detected.] Here we present hypocenters for 569 local events that have S-P times less than 17 seconds (i.e. within ~125 km of the array) using hand-picked arrival times and a 1D velocity model derived from a 2D seismic refraction profile through the region (Moscoso et al 2011, EPSL). We analyze the distribution of seismicity in the context of published slip models, ChilePEPPER high-resolution seismic reflection data, critical taper analysis done by Cubas et al 2013 (EPSL), and offshore gravity data. The data show distinct segmentation within the outer prism. The northern section of the study area is characterized by a lack of seismicity, accretion of nearly all incoming sediment and a prism at critical taper. In contrast, abundant seismicity, significant sediment underthrusting at the deformation front and a prism below critical taper angle characterize the southern part of the study area. Both coseismic slip and post-rupture local seismicity can be related to density anomalies within the upper plate as revealed by free air gravity data corrected for the effects of bathymetry and the subducting plate. [ChilePEPPER - Project Evaluating Prism Post-Earthquake Response

  6. New evidence of spontaneous cure in human Chagas' disease Novas evidências da cura espontânea da doença de Chagas humana

    Directory of Open Access Journals (Sweden)

    Sonia S. Francolino

    2003-01-01

    Full Text Available A new case of spontaneous cure of human Chagas' disease is described in Uruguay. An 87-year-old man who had a typical acute phase of Trypanosoma cruzi infection in 1947 and never received specific treatment against the disease, when examined in 1998 revealed several completely negative parasitological and serological tests, including traditional serology, PCR and flow cytometry. As a whole, such findings fulfill the current criteria to define the cure of Chagas' disease. Clinical data suggest the possibility of a benign evolution of Chagas' disease in this case, but the basic findings (slight cardiac and esophageal impairment could also be due to the advanced age of the patient.Um novo caso de cura espontânea da doença de Chagas humana é descrito no Uruguai. Um homem de 87 anos de idade que teve um quadro típico de doença de Chagas aguda em 1947 e nunca recebeu tratamento específico, revelou-se em 1998 completamente negativo para exames sorológicos e parasitológicos, inclusive por PCR e citometria de fluxo. Estes achados, no conjunto, preenchem os critérios correntes para a definição de cura da doença de Chagas. O quadro clínico atual sugere a possiblidade de uma evolução benigna da doença de Chagas, mas os achados principais (comprometimento leve do coração e do esôfago poderiam também dever-se à avançada idade do paciente.

  7. Chagas Disease in Dogs from Endemic Areas of Costa Rica

    Directory of Open Access Journals (Sweden)

    Montenegro Victor M

    2002-01-01

    Full Text Available Dogs with the presumptive diagnosis of Chagas disease are commonly sent to our School of Veterinary Medicine by independent veterinarians. This prompted us to evaluate the prevalence of canine trypanosomiasis in some villages of the Central Valley of Costa Rica. A total of 54 dogs (21 males and 33 females from five rural villages, with ages between 3 months and 10 years old, were bled and submitted to three serological tests: indirect immunofluorescence, indirect hemagglutination and ELISA. Among all animals, 15 (27.7% revealed antibodies (6 pure bred and 9 mongrels and in 3 of them the parasite was also demonstrated by xenodiagnosis. All positive animals except 1, and 9 negative animals (control group were examined by X-rays and electrocardiography, revealing different degrees of cardiomegaly and ECG alteration, consistent with Chagas disease pathology in one dog (SA-11 of the infected ones. Examination of 50 inhabitants living in the houses where dogs and Triatoma dimidiata were found, yielded negative serological reactions. This was assumed to support the hypothesis that dogs are commonly infected by the oral route, a more effective means of infection compared with the vector transmission mechanism that occurs in humans.

  8. A Multi-species Bait for Chagas Disease Vectors

    Science.gov (United States)

    Mota, Theo; Vitta, Ana C. R.; Lorenzo-Figueiras, Alicia N.; Barezani, Carla P.; Zani, Carlos L.; Lazzari, Claudio R.; Diotaiuti, Liléia; Jeffares, Lynne; Bohman, Björn; Lorenzo, Marcelo G.

    2014-01-01

    Background Triatomine bugs are the insect vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. These insects are known to aggregate inside shelters during daylight hours and it has been demonstrated that within shelters, the aggregation is induced by volatiles emitted from bug feces. These signals promote inter-species aggregation among most species studied, but the chemical composition is unknown. Methodology/Principal Findings In the present work, feces from larvae of the three species were obtained and volatile compounds were identified by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). We identified five compounds, all present in feces of all of the three species: Triatoma infestans, Panstrongylus megistus and Triatoma brasiliensis. These substances were tested for attractivity and ability to recruit insects into shelters. Behaviorally active doses of the five substances were obtained for all three triatomine species. The bugs were significantly attracted to shelters baited with blends of 160 ng or 1.6 µg of each substance. Conclusions/Significance Common compounds were found in the feces of vectors of Chagas disease that actively recruited insects into shelters, which suggests that this blend of compounds could be used for the development of baits for early detection of reinfestation with triatomine bugs. PMID:24587457

  9. Research priorities for Chagas disease, human African trypanosomiasis and leishmaniasis.

    Science.gov (United States)

    2012-01-01

    This report provides a review and analysis of the research landscape for three diseases - Chagas disease, human African trypanosomiasis and leishmaniasis - that disproportionately afflict poor and remote populations with limited access to health services. It represents the work of the disease reference group on Chagas Disease, Human African Trypanosomiasis and Leishmaniasis (DRG3) which was established to identify key research priorities through review of research evidence and input from stakeholders' consultations. The diseases, which are caused by related protozoan parasites, are described in terms of their epidemiology and diseases burden, clinical forms and pathogenesis, HIV coinfection, diagnosis, drugs and drug resistance, vaccines, vector control, and health-care interventions. Priority areas for research are identified based on criteria such as public health relevance, benefit and impact on poor populations and equity, and feasibility. The priorities are found in the areas of diagnostics, drugs, vector control, asymptomatic infection, economic analysis of treatment and vector control methods, and in some specific issues such as surveillance methods or transmission-blocking vaccines for particular diseases. This report will be useful to researchers, policy and decision-makers, funding bodies, implementation organizations, and civil society. This is one of ten disease and thematic reference group reports that have come out of the TDR Think Tank, all of which have contributed to the development of the Global Report for Research on Infectious Diseases of Poverty, available at: www.who.int/tdr/stewardship/global_report/en/index.html.

  10. Chagas disease transmission by consumption of game meat: systematic review.

    Science.gov (United States)

    Sangenis, Luiz Henrique Conde; Nielebock, Marco Antonio Prates; Santos, Ceumara da Silva; Silva, Mateus Curty Carriello da; Bento, Glauber Motta Ribeiro

    2016-01-01

    To evaluate the influence of game meat consumption in Chagas disease (CD) transmission, the conditions under which it occurs and the frequency of reports in the literature. Through systematic review, databases PubMed, LILACS, MEDLINE, and SciELO were consulted, and articles written in Portuguese, English, and Spanish were included, with no limitation over publication date. We used the following descriptors: oral, transmission, meat, wild animals, hunt, carnivory, and Chagas disease. Articles that mentioned consumption of animal meat as a form of human transmission of CD were included. We used epidemiological, clinical, and laboratory evidence criteria to confirm cases. Among the 298 articles identified, only six met the eligibility criteria. Only five episodes of oral transmission through wild animal meat or blood consumption were identified. However, in two of them, the possibility of vectorial transmission could not be ruled out. Most reports met the epidemiological, clinical, and laboratory evidence criteria established to support the transmission. Though CD transmission is uncommon, hunting and consumption of wild mammals that serve as Trypanosoma cruzi reservoirs should be discouraged in endemic countries in light of the risks inherent to these practices.

  11. Urban transmission of Chagas disease in Cochabamba, Bolivia

    Directory of Open Access Journals (Sweden)

    N Medrano-Mercado

    2008-08-01

    Full Text Available Chagas disease is a major public health problem in Bolivia. In the city of Cochabamba, 58% of the population lives in peripheral urban districts ("popular zones" where the infection prevalence is extremely high. From 1995 to 1999, we studied the demographics of Chagas infections in children from five to 13 years old (n = 2218 from the South zone (SZ and North zone (NZ districts, which differ in social, environmental, and agricultural conditions. Information gathered from these districts demonstrates qualitative and quantitative evidence for the active transmission of Trypanosoma cruzi in urban Cochabamba. Seropositivity was high in both zones (25% in SZ and 19% in NZ. We observed a high risk of infection in children from five to nine years old in SZ, but in NZ, a higher risk occurred in children aged 10-13, with odds ratio for infection three times higher in NZ than in SZ. This difference was not due to triatomine density, since more than 1,000 Triatoma infestans were captured in both zones, but was possibly secondary to the vector infection rate (79% in SZ and 37% in NZ. Electrocardiogram abnormalities were found to be prevalent in children and pre-adolescents (SZ = 40%, NZ = 17%, indicating that under continuous exposure to infection and re-infection, a severe form of the disease may develop early in life. This work demonstrates that T. cruzi infection should also be considered an urban health problem and is not restricted to the rural areas and small villages of Bolivia.

  12. Epidemiology of Chagas disease in Ecuador. A brief review

    Directory of Open Access Journals (Sweden)

    Aguilar V H Marcelo

    1999-01-01

    Full Text Available Chagas disease is a complex public health problem that has been underestimated in Ecuador. Here we review the relevant published information, and present unpublished and new data that help to understand the current Chagas disease epidemiological situation and its evolution in the country. Three main characteristics have been identified: (i persistence of Trypanosoma cruzi transmission in already known foci; (ii a marked endemicity in some urban areas of Guayaquil; and (iii the transformation of new Amazon foci into truly endemic areas. The situation in other suspect areas remains uncertain. Five Triatominae species have been implicated in the transmission of T. cruzi to people in Ecuador (Triatoma dimidiata, Rhodnius ecuadoriensis, R. pictipes, R. robustus and Panstrongylus geniculatus, but some others may also play a role in some areas (P. rufotuberculatus, P. howardi, T. carrioni and P. chinai. Other Triatominae reported seem to have little or no epidemiological relevance (T. venosa, T. dispar, Eratyrus mucronatus, E. cuspidatus, P. lignarius and Cavernicola pilosa. High frequency of acute cases and severe chronic disease has been observed. Although cardiomyopathy is more frequent, serious digestive disease is also present. It is estimated that around 120,000-200,000 people may be infected. 2.2 to 3.8 million people are estimated to live under transmission risk conditions.

  13. [Dental enamel prisms of Mesopithecus pentelicus Wagner, 1839, compared with recent cercopithecids (Primates: Cercopithecidae)].

    Science.gov (United States)

    Dostal, A; Zapfe, H

    1986-01-01

    The dental enamel prisms of Cercopithecidae were examined by scanning electron microscopy. The main task of this study was to show the prism morphology representatives of different genera as well as their comparison with the fossil Mesopithecus pentelicus Wagner, 1839. The method used to show the enamel prisms was to etch the tooth surface with hydrochloric acid. In this way the outlines of the prisms were better contrasted for the descriptive morphology of the prisms than in etching with phosphoric acid. Two types were determined, in accord with the systematic division into subfamilies. In the subfamily Cercopithecinae elongated slender prisms were dominating, some with pointed, others with truncated tops. Most characteristic of this type were Macaca and Cercopithecus. An exception was Papio hamadryas which had broader, rounded prisms. In this way it differed largely from P. anubis whose prisms were short and mostly triangular. A very interesting fact was that very different patterns were found in P. anubis and P. hamadryas, although these two species are regarded as only one species by many authors. The second subfamily, the Colobinae, was characterized by broader prisms with a rounded shape, nearly as long as wide. Exceptions of the 'Colobine type' were at first Colobus with prisms little longer than wide and secondly Nasalis, with mostly parallel sides and truncated tops of the prisms. The prism outlines of Mesopithecus showed the greatest similarity to those of Presbytis which represents the characteristic 'Colobine type'. This fact confirmed the actual systematic position of the fossil Mesopithecus within the subfamily Colobinae. In addition to previously known primitive features of Mesopithecus within the subfamily of Colobinae, we present here a further concrete, common feature with asiatic Colobines.

  14. 3D Printed Prisms with Tunable Dispersion for the THz Frequency Range

    Science.gov (United States)

    Busch, Stefan F.; Castro-Camus, Enrique; Beltran-Mejia, Felipe; Balzer, Jan C.; Koch, Martin

    2018-06-01

    Here, we present a 3D printed prism for THz waves made out of an artificial dielectric material in which the dispersion can be tuned by external compression. The artificial material consists of thin dielectric layers with variable air spacings which has been produced using a fused deposition molding process. The material properties are carefully characterized and the functionality of the prisms is in a good agreement with the underlying theory. These prisms are durable, lightweight, inexpensive, and easy to produce.

  15. 3D Printed Prisms with Tunable Dispersion for the THz Frequency Range

    Science.gov (United States)

    Busch, Stefan F.; Castro-Camus, Enrique; Beltran-Mejia, Felipe; Balzer, Jan C.; Koch, Martin

    2018-04-01

    Here, we present a 3D printed prism for THz waves made out of an artificial dielectric material in which the dispersion can be tuned by external compression. The artificial material consists of thin dielectric layers with variable air spacings which has been produced using a fused deposition molding process. The material properties are carefully characterized and the functionality of the prisms is in a good agreement with the underlying theory. These prisms are durable, lightweight, inexpensive, and easy to produce.

  16. PRISM -- A tool for modelling proton energy deposition in semiconductor materials

    International Nuclear Information System (INIS)

    Oldfield, M.K.; Underwood, C.I.

    1996-01-01

    This paper presents a description of, and test results from, a new PC based software simulation tool PRISM (Protons in Semiconductor Materials). The model describes proton energy deposition in complex 3D sensitive volumes of semiconductor materials. PRISM is suitable for simulating energy deposition in surface-barrier detectors and semiconductor memory devices, the latter being susceptible to Single-Event Upset (SEU) and Multiple-Bit Upset (MBU). The design methodology on which PRISM is based, together with the techniques used to simulate ion transport and energy deposition, are described. Preliminary test results used to analyze the PRISM model are presented

  17. The demagnetizing field of a non-uniform rectangular prism

    DEFF Research Database (Denmark)

    Smith, Anders; Nielsen, Kaspar Kirstein; Christensen, Dennis

    2010-01-01

    The effect of demagnetization on the magnetic properties of a rectangular ferromagnetic prism under non-uniform conditions is investigated. A numerical model for solving the spatially varying internal magnetic field is developed, validated and applied to relevant cases. The demagnetizing field...... is solved by an analytical calculation and the coupling between applied field, the demagnetization tensor field and spatially varying temperature is solved through iteration. We show that the demagnetizing field is of great importance in many cases and that it is necessary to take into account the non...

  18. Thermal stresses in long prisms by relaxation methods

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, J D [Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1959-07-15

    A general method is presented for calculating the elastic thermal stresses in long prisms which are producing heat and are not solvable by simple analytical methods. The problem of an inverted lattice i.e. an hexagonal coolant passage surrounded by hexagonal fuel elements is considered and the temperature and principal thermal stress distributions evaluated for the particular case of 20% coolant. The maximum thermal stress for this type of fuel element is about the same as the maximum thermal stress in a cylindrical fuel element surrounded by a sea of coolant assuming the existence of the same maximum temperature drop and material properties. (author)

  19. Thermal stresses in long prisms by relaxation methods

    International Nuclear Information System (INIS)

    Cummins, J.D.

    1959-07-01

    A general method is presented for calculating the elastic thermal stresses in long prisms which are producing heat and are not solvable by simple analytical methods. The problem of an inverted lattice i.e. an hexagonal coolant passage surrounded by hexagonal fuel elements is considered and the temperature and principal thermal stress distributions evaluated for the particular case of 20% coolant. The maximum thermal stress for this type of fuel element is about the same as the maximum thermal stress in a cylindrical fuel element surrounded by a sea of coolant assuming the existence of the same maximum temperature drop and material properties. (author)

  20. Analysis of transverse field distributions in Porro prism resonators

    CSIR Research Space (South Africa)

    Litvin, IA

    2007-01-01

    Full Text Available in 1962 by Gould et al1 as a means to overcome misalignment problems in optical resonators employing Fabry-Perot cavities, by replacing the end face mirrors with crossed roof prisms. Lasers based on this principle have been developed over the years2... Optronics for the use of their laser and for making experimental data available to us. We would also like to thank Dr Dieter Preussler and Mr Daniel Esser for useful discussions. REFERENCES 1. G. Gould, S. Jacobs, P. Rabinowitz and T. Shultz...

  1. Prism reactor system design and analysis of postulated unscrammed events

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.; Slovik, G.C.

    1991-08-01

    Key safety characteristics of the PRISM reactor system include the passive reactor shutdown characteristic and the passive shutdown heat removal system, RVACS. While these characteristics are simple in principle, the physical processes are fairly complex, particularly for the passive reactor shutdown. It has been possible to adapt independent safety analysis codes originally developed for the Clinch River Breeder Reactor review, although some limitations remain. In this paper, the analyses of postulated unscrammed events are discussed, along with limitations in the predictive capabilities and plans to correct the limitations in the near future. 6 refs., 4 figs

  2. PRISM reactor system design and analysis of postulated unscrammed events

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.; Slovik, G.C.

    1991-01-01

    Key safety characteristics of the PRISM reactor system include the passive reactor shutdown characteristic and the passive shutdown heat removal system, RVACS. While these characteristics are simple in principle, the physical processes are fairly complex, particularly for the passive reactor shutdown. It has been possible to adapt independent safety analysis codes originally developed for the Clinch River Breeder Reactor review, although some limitations remain. In this paper, the analyses of postulated unscrammed events are discussed, along with limitations in the predictive capabilities and plans to correct the limitations in the near future. (author)

  3. Design of a fast runback feature for PRISM control

    International Nuclear Information System (INIS)

    Wagner, W.K.; Rhow, S.K.; Daniel, W.R.; Dayal, Y.; Gaubatz, D.C.

    1988-01-01

    The nine power reactor inherently safe modules (PRISM) are controlled and their operation coordinated by a hierarchical, distributed, digital plant control system (PCS). This paper describes the fast runback features of the PCS. Fast runback consists of PCS directed reactor module shutdown with accompanying reductions of coolant flows. Analyses have shown that the PCS fast runback adequately terminates duty cycle events initiated in the balance of plant and the steam generating system, results in lower thermal shock to the reactor than scram, and reduces the number of scrams by approximately a factor of five

  4. PRISM reactor system design and analysis of postulated unscrammed events

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.; Slovik, G.C.; Rosztoczy, Z.; Lane, J.

    1991-01-01

    Key safety characteristics of the PRISM reactor system include the passive reactor shutdown characteristics and the passive shutdown heat removal system, RVACS. While these characteristics are simple in principle, the physical processes are fairly complex, particularly for the passive reactor shutdown. It has been possible to adapt independent safety analysis codes originally developed for the Clinch River Breeder Reactor review, although some limitations remain. In this paper, the analyses of postulated unscrammed events are discussed, along with limitations in the predictive capabilities and plans to correct the limitations in the near future. 6 refs., 4 figs

  5. Inhibition of Autoimmune Chagas-Like Heart Disease by Bone Marrow Transplantation

    Czech Academy of Sciences Publication Activity Database

    Guimaro, M.C.; Alves, R. J. V.; Rose, E.; Sousa, A.O.; Rosa, A.D.; Hecht, M.M.; Sousa, M.V.; Andrade, R.R.; Vital, T.; Plachý, Jiří; Nitz, N.; Hejnar, Jiří; Gomes, C.C.; Teixeira, A.R.L.

    2014-01-01

    Roč. 8, č. 12 (2014) ISSN 1935-2735 Institutional support: RVO:68378050 Keywords : Chagas disease * inbred chicken * adoptive transfer of immunity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.446, year: 2014

  6. Mapping of Chagas disease research: analysis of publications in the period between 1940 and 2009

    Directory of Open Access Journals (Sweden)

    José Manuel Ramos

    2011-12-01

    Full Text Available INTRODUCTION: Publications are often used as a measure of success in research work. Chagas disease occurs in Central and Southern America. However, during the past years, the disease has been occurring outside Latin America due to migration from endemic zones. This article describes a bibliometric review of the literature on Chagas disease research indexed in PubMed during a 70-year period. METHODS: Medline was used via the PubMed online service of the U.S. National Library of Medicine from 1940 to 2009. The search strategy was: Chagas disease [MeSH] OR Trypanosoma cruzi [MeSH]. RESULTS: A total of 13,989 references were retrieved. The number of publications increased steadily over time from 1,361 (1940-1969 to 5,430 (2000-2009 (coefficient of determination for linear fit, R²=0.910. Eight journals contained 25% of the Chagas disease literature. Of the publications, 64.2% came from endemic countries. Brazil was the predominant country (37%, followed by the United States (17.6% and Argentina (14%. The ranking in production changed when the number of publications was normalized by estimated cases of Chagas disease (Panama and Uruguay, population (Argentina and Uruguay, and gross domestic product (Bolivia and Brazil. CONCLUSIONS: Several Latin American countries, where the prevalence of T. cruzi infection was not very high, were the main producers of the Chagas disease literature, after adjusting for economic and population indexes. The countries with more estimated cases of Chagas disease produced less research on Chagas disease than some developed countries.

  7. Follow up Evaluation of Air Force Blood Donors Screening Positive for Chagas Disease

    Science.gov (United States)

    2017-10-05

    59 MDW/SGVU SUBJECT: Professional Presentation Approval 31 JULY2017 Your paper, entitled Follow-up Evaluation of Air Force Blood Donors Screening...PUBLISHED OR PRESENTED: Follow-up Evaluation of Air Force Blood Donors Screening Positive for Chagas Disease 7. FUNDING RECEIVED FOR THIS STUDY? 0...PREVIOUS EDITIONS ARE OBSOLETE 50. DATE Page 3 of 3 Pages Follow-up Evaluation of Air Force Blood Donors Screening Positive for Chagas Disease

  8. The PRISM (Pliocene Palaeoclimate) reconstruction: Time for a paradigm shift

    Science.gov (United States)

    Dowsett, Harry J.; Robinson, Marci M.; Stoll, Danielle K.; Foley, Kevin M.; Johnson, Andrew L. A.; Williams, Mark; Riesselman, Christina

    2013-01-01

    Global palaeoclimate reconstructions have been invaluable to our understanding of the causes and effects of climate change, but single-temperature representations of the oceanic mixed layer for data–model comparisons are outdated, and the time for a paradigm shift in marine palaeoclimate reconstruction is overdue. The new paradigm in marine palaeoclimate reconstruction stems the loss of valuable climate information and instead presents a holistic and nuanced interpretation of multi-dimensional oceanographic processes and responses. A wealth of environmental information is hidden within the US Geological Survey's Pliocene Research,Interpretation and Synoptic Mapping (PRISM) marine palaeoclimate reconstruction, and we introduce here a plan to incorporate all valuable climate data into the next generation of PRISM products. Beyond the global approach and focus, we plan to incorporate regional climate dynamics with emphasis on processes, integrating multiple environmental proxies wherever available in order to better characterize the mixed layer, and developing a finer time slice within the Mid-Piacenzian Age of the Pliocene, complemented by underused proxies that offer snapshots into environmental conditions. The result will be a proxy-rich, temporally nested, process-oriented approach in a digital format - a relational database with geographic information system capabilities comprising a three-dimensional grid representing the surface layer, with a plethora of data in each cell.

  9. Performance of the prism reactor's passive decay heat removal system

    International Nuclear Information System (INIS)

    Magee, P.M.; Hunsbedt, A.

    1989-01-01

    The PRISM modular reactor concept has a totally passive safety-grade decay heat removal system referred to as the Reactor Vessel Auxiliary Cooling System (RVACS) that rejects heat from the reactor by radiation and natural convection of air. The system is inherently reliable and is not subject to the failure modes commonly associated with active cooling systems. The thermal performance of RVACS exceeds requirements and significant thermal margins exist. RVACS has been shown to perform its function under many postulated accident conditions. The PRISM power plant is equipped with three methods for shutdown: condenser cooling in conjunction with intermediate sodium and steam generator systems, and auxiliary cooling system (ACS) which removes heat from the steam generator by natural convection of air and transport of heat from the core by natural convection in the primary and intermediate systems, and a safety- grade reactor vessel auxiliary cooling system (RVACS) which removes heat passively from the reactor containment vessel by natural convection of air. The combination of one active and two passive systems provides a highly reliable and economical shutdown heat removal system. This paper provides a summary of the RVACS thermal performance for expected operating conditions and postulated accident events. The supporting experimental work, which substantiates the performance predictions, is also summarized

  10. Chagas disease: What is known and what should be improved: a systemic review

    Directory of Open Access Journals (Sweden)

    José Rodrigues Coura

    2012-06-01

    Full Text Available This study consists of a broad review on what is known and what should be improved regarding knowledge of Chagas disease, not only through analysis on the main studies published on the topics discussed, but to a large extent based on experience of this subject, acquired over the past 50 years (1961-2011. Among the subjects covered, we highlight the pathogenesis and evolution of infection by Trypanosoma cruzi, drugs in use and new strategies for treating Chagas disease; the serological tests for the diagnosis and the controls of cure the infection; the regional variations in prevalence, morbidity and response to treatment of the disease; the importance of metacyclogenesis of T. cruzi in different species of triatomines and its capacity to transmit Chagas infection; the risks of adaptation of wild triatomines to human dwellings; the morbidity and need for a surveillance and control program for Chagas disease in the Amazon region and the need to prioritize initiatives for controlling Chagas disease in Latin America and Mexico and in non-endemic countries, which is today a major international dilemma. Finally, we raise the need for to create a new initiative for controlling Chagas disease in the Gran Chaco, which involves parts of Argentina, Bolivia and Paraguay.

  11. Risk factors for Chagas disease among pregnant women in El Salvador.

    Science.gov (United States)

    Sasagawa, Emi; Aiga, Hirotsugu; Corado, Edith Y; Cuyuch, Blanca L; Hernández, Marta A; Guevara, Ana V; Romero, José E; Ramos, Hector M; Cedillos, Rafael A; Misago, Chizuru; Kita, Kiyoshi

    2015-03-01

    To determine the seroprevalence of Chagas disease among pregnant women and estimate the risk factors for Chagas disease during pregnancies. Community-based serological tests on Trypanosoma cruzi and structured interviews on socio-demographic and socio-economic status were conducted with pregnant women registered at three health centres in Sonsonate province, El Salvador. Of 797 pregnant women participating in the study, 29 (3.6%) were infected with Chagas disease. None had clinical symptoms. The results of bivariate analyses showed the significant association between seropositivity and maternal age ≥35 years, anaemia, illiteracy, having no formal school education and having knowledge on Chagas disease (P < 0.05). The results of multivariate analysis indicate that age ≥35 years and anaemia were significantly associated with being infected with Chagas disease among pregnant women (OR = 3.541 and 5.197, respectively). We recommend that the national Chagas disease control programme be better coordinated with the national maternal and child health programme to introduce blood screening for T. cruzi during antenatal visits. If financial constraint allows systematic blood screening to be only partially implemented, resources should be focused on pregnant women ≥35 years and women who have anaemia. © 2014 John Wiley & Sons Ltd.

  12. Agrochemicals against malaria, sleeping sickness, leishmaniasis and Chagas disease.

    Science.gov (United States)

    Witschel, Matthias; Rottmann, Matthias; Kaiser, Marcel; Brun, Reto

    2012-01-01

    In tropical regions, protozoan parasites can cause severe diseases with malaria, leishmaniasis, sleeping sickness, and Chagas disease standing in the forefront. Many of the drugs currently being used to treat these diseases have been developed more than 50 years ago and can cause severe adverse effects. Above all, resistance to existing drugs is widespread and has become a serious problem threatening the success of control measures. In order to identify new antiprotozoal agents, more than 600 commercial agrochemicals have been tested on the pathogens causing the above mentioned diseases. For all of the pathogens, compounds were identified with similar or even higher activities than the currently used drugs in applied in vitro assays. Furthermore, in vivo activity was observed for the fungicide/oomyceticide azoxystrobin, and the insecticide hydramethylnon in the Plasmodium berghei mouse model, and for the oomyceticide zoxamide in the Trypanosoma brucei rhodesiense STIB900 mouse model, respectively.

  13. Helietta apiculata: a tropical weapon against Chagas disease.

    Science.gov (United States)

    Elena Ferreira, Maria; Rojas de Arias, Antonieta; Yaluff, Gloria; Vera de Bilbao, Ninfa; Nakayama, Hector; Torres, Susana; Schinini, Alicia; Torres, Susana; Serna, Elva; Torrecilhas, Ana Claudia; Fournet, Alain; Cebrián-Torrejón, Gerardo

    2018-05-10

    The present study pretends to evaluate the in vivo efficacy of the crude chloroform bark extract of Helietta apiculata, then the activity will be compared with the reference drug, benznidazole, in acute Trypanosoma cruzi infected mice when administered by oral route. The chloroformic extract of Helieta apiculata was administered by oral route at 5, 10 and 50 mg/kg daily for two weeks. This study has shown a moderate efficacy of the H. apiculata bark extract in reducing T. cruzi parasitaemia in 42 to 54% after a monitoring of 60 days post-infection and when compared with control groups. Concerning mice mortality, only two only two mice died, one from the control group and the other one from the group threated with 10 mg of the chlorofom extract of H. apiculata, suggesting the potential of H. apiculta extracts as a safe and inexpensive treatment of Chagas disease.

  14. Prism foil from an LCD monitor as a tool for teaching introductory optics

    International Nuclear Information System (INIS)

    Planinsic, Gorazd; Gojkosek, Mihael

    2011-01-01

    Transparent prism foil is part of a backlight system in LCD monitors that are widely used today. This paper describes the optical properties of the prism foil and several pedagogical applications suitable for undergraduate introductory physics level. Examples include experiments that employ refraction, total internal reflection, diffraction and image formation in a nontrivial way and are therefore particularly useful for active learning strategies.

  15. Prism foil from an LCD monitor as a tool for teaching introductory optics

    Energy Technology Data Exchange (ETDEWEB)

    Planinsic, Gorazd; Gojkosek, Mihael, E-mail: gorazd.planinsic@fmf.uni-lj.si [Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19 (Slovenia)

    2011-03-15

    Transparent prism foil is part of a backlight system in LCD monitors that are widely used today. This paper describes the optical properties of the prism foil and several pedagogical applications suitable for undergraduate introductory physics level. Examples include experiments that employ refraction, total internal reflection, diffraction and image formation in a nontrivial way and are therefore particularly useful for active learning strategies.

  16. Salt-induced square prism Pd microtubes and their ethanol electrocatalysis properties

    International Nuclear Information System (INIS)

    Jiang, Kunpeng; Ma, Shenghua; Wang, Yinan; Zhang, Ying; Han, Xiaojun

    2017-01-01

    Highlights: • A simple method is established to fabricate square prism Pd microtubes. • The novel square prism Pd microtubes are based on a salt-induced aggregation event. • The surface of the square prism tubes convert from cataphracted nanosheets to spheres after calcinations treatment. • The square prism pure Pd tubes show excellent electro catalytic activity towards ethanol oxidation. - Abstract: The synthesis of square prism tubes are always challenging due to their thermo and dynamical instability. We demonstrated a simple method using Pd"2"+ doped PoPD oligomers as building blocks to assemble into 1D square prism metal-organic microtubes, which consists of cataphracted nanosheets on the surfaces. After high temperature treatment, the microtubes became square prism Pd tubes with a cross section size of 3 μm. The pure Pd microtubes showed excellent catalyzing activity towards the electro oxidation of ethanol. Their electrochemically active surface area is 48.2 m"2 g"−"1, which indicates the square prism Pd tubes have great potential in the field of fuel cell.

  17. Physical optics modeling of modal patterns in a crossed porro prism resonator

    CSIR Research Space (South Africa)

    Litvin, IA

    2006-07-01

    Full Text Available A physical optics model is proposed to describe the transverse modal patterns in crossed Porro prism resonators. The model departs from earlier attempts in that the prisms are modeled as non-classical rotating elements with amplitude and phase...

  18. Prism Foil from an LCD Monitor as a Tool for Teaching Introductory Optics

    Science.gov (United States)

    Planinsic, Gorazd; Gojkosek, Mihael

    2011-01-01

    Transparent prism foil is part of a backlight system in LCD monitors that are widely used today. This paper describes the optical properties of the prism foil and several pedagogical applications suitable for undergraduate introductory physics level. Examples include experiments that employ refraction, total internal reflection, diffraction and…

  19. Salt-induced square prism Pd microtubes and their ethanol electrocatalysis properties

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Kunpeng; Ma, Shenghua; Wang, Yinan; Zhang, Ying; Han, Xiaojun, E-mail: hanxiaojun@hit.edu.cn

    2017-05-01

    Highlights: • A simple method is established to fabricate square prism Pd microtubes. • The novel square prism Pd microtubes are based on a salt-induced aggregation event. • The surface of the square prism tubes convert from cataphracted nanosheets to spheres after calcinations treatment. • The square prism pure Pd tubes show excellent electro catalytic activity towards ethanol oxidation. - Abstract: The synthesis of square prism tubes are always challenging due to their thermo and dynamical instability. We demonstrated a simple method using Pd{sup 2+} doped PoPD oligomers as building blocks to assemble into 1D square prism metal-organic microtubes, which consists of cataphracted nanosheets on the surfaces. After high temperature treatment, the microtubes became square prism Pd tubes with a cross section size of 3 μm. The pure Pd microtubes showed excellent catalyzing activity towards the electro oxidation of ethanol. Their electrochemically active surface area is 48.2 m{sup 2} g{sup −1}, which indicates the square prism Pd tubes have great potential in the field of fuel cell.

  20. Chagas disease study using satellite image processing: A Bolivian case

    Science.gov (United States)

    Vargas-Cuentas, Natalia I.; Roman-Gonzalez, Avid; Mantari, Alicia Alva; Muñoz, Luis AnthonyAucapuma

    2018-03-01

    Remote sensing is the technology that has enabled us to obtain information about the Earth's surface without directly contacting it. For this reason, currently, the Bolivian state has considered a list of interesting applications of remote sensing in the country, including the following: biodiversity and environment monitoring, mining and geology, epidemiology, agriculture, water resources and land use planning. The use of satellite images has become a great tool for epidemiology because with this technological advance we can determine the environment in which transmission occurs, the distribution of the disease and its evolution over time. In that context, one of the important diseases related to public health in Bolivia is Chagas disease, also known as South American Trypanosomiasis. Chagas is caused by a blood-sucking bug or Vinchuca, which causes serious intestinal and heart long term problems and affects 33.4% of the Bolivian population. This disease affects mostly humble people, so the Bolivian state invests millions of dollars to acquire medicine and distribute it for free. Due to the above reasons, the present research aims to analyze some areas of Bolivia using satellite images for developing an epidemiology study. The primary objective is to understand the environment in which the transmission of the disease happens, and the climatic conditions under which occurs, observe the behavior of the blood-sucking bug, identify in which months occur higher outbreaks, in which months the bug leaves its eggs, and under which weather conditions this happens. All this information would be contrasted with information extracted from the satellite images and data from the Ministry of Health, and the Institute of Meteorology in Bolivia. All this data will allow us to have a more integrated understanding of this disease and promote new possibilities to prevent and control it.

  1. ePRISM: A case study in multiple proxy and mixed temporal resolution integration

    Science.gov (United States)

    Robinson, Marci M.; Dowsett, Harry J.

    2010-01-01

    As part of the Pliocene Research, Interpretation and Synoptic Mapping (PRISM) Project, we present the ePRISM experiment designed I) to provide climate modelers with a reconstruction of an early Pliocene warm period that was warmer than the PRISM interval (similar to 3.3 to 3.0 Ma), yet still similar in many ways to modern conditions and 2) to provide an example of how best to integrate multiple-proxy sea surface temperature (SST) data from time series with varying degrees of temporal resolution and age control as we begin to build the next generation of PRISM, the PRISM4 reconstruction, spanning a constricted time interval. While it is possible to tie individual SST estimates to a single light (warm) oxygen isotope event, we find that the warm peak average of SST estimates over a narrowed time interval is preferential for paleoclimate reconstruction as it allows for the inclusion of more records of multiple paleotemperature proxies.

  2. A doença de Chagas no Paraná Chagas disease in the state of Paraná

    Directory of Open Access Journals (Sweden)

    H. C. de Souza-Araujo

    1954-06-01

    Full Text Available In recent speech in Curitiba (May 22nd, 1954, Dr. Mario Pinotti, Director, Serviço Nacional da Malaria, informed that his personnel started on February, 1953, a survey upon chagas Disease in 23 counties of the State of Paraná, South Brazil. out of 895 places surveyed, 678, or 75.7%, were infected by Triatoma infestans klug 1834 and in 234 out of those 678, or 34.5%, this vector was infected by Trypanosoma cruzi. The general natural infection of the insects examined reached 18.86%. The serological survey (Machado-Guerreiro test was positive in 10.7% of the persons examined in jacarezinho and in 28.3% of those living in Bôa Vista. These data suggested the author to actualise the subject. During his control of severe outbreack of malaria in the North part of Paraná, from march to June 1917 he worked in 8 counties. March 1917 he photographed in Boa Vista four girls, severe cases of chronic malaria, two of which showed bi-palpebral oedema, later on considered by Dr. Pinho Simões (1943 as Romanã syndrome (created in 1935 and Prof. Salvador Mazza (1946 classified as typical cases of Chagas' Disease. now, being elapsed 36 years, the National Service of Malaria confirmed the discovery. The region surveyed was populated, in the beginning of this century, by immigrants from the State of Minas Gerais, from where the author believes that were imported the disease and its vectors. In April 1917 the A. discovered that the old town Jatahy was a big focus of Triatoma megista (now Panstrongylus megistus0. All its 43 houses were strongly infested by such hematophagus and amongst the 200 inhabitants seen many were suspicious cases of chronic cases of Chagas's Disease. In the Indians town (three tribes of S. Pedro D' Alcantara, situated in front of Jatahy, in the left side of the river Tibagy, there were no Triatomas nor suspicious cases of trypanosomiasis. In 1919 the author started the control of the endemics by destroying the foci of Triatomas and reforming

  3. Chagas disease and globalization of the Amazon La enfermedad de Chagas y la globalización de la Amazonia

    Directory of Open Access Journals (Sweden)

    Roberto Briceño-León

    2007-01-01

    Full Text Available The increasing number of autochthonous cases of Chagas disease in the Amazon since the 1970s has led to fear that the disease may become a new public health problem in the region. This transformation in the disease's epidemiological pattern in the Amazon can be explained by environmental and social changes in the last 30 years. The current article draws on the sociological theory of perverse effects to explain these changes as the unwanted result of the shift from the "inward" development model prevailing until the 1970s to the "outward" model that we know as globalization, oriented by industrial forces and international trade. The current article highlights the implementation of five new patterns in agriculture, cattle-raising, mining, lumbering, and urban occupation that have generated changes in the environment and the traditional indigenous habitat and have led to migratory flows, deforestation, sedentary living, the presence of domestic animals, and changes in the habitat that facilitate colonization of human dwellings by vectors and the domestic and work-related transmission of the disease. The expansion of Chagas disease is thus a perverse effect of the globalization process in the Amazon.El incremento de casos autóctonos de la enfermedad de Chagas en la Amazonia a partir de los años setenta hace temer que pueda convertirse en un novedoso problema de salud pública en la región. Este cambio del patrón epidemiológico de la enfermedad en la región amazónica debe ser explicado por las transformaciones ambientales y sociales que han ocurrido en los pasados treinta años. Este artículo utiliza la teoría sociológica de los efectos perversos para explicar esos cambios como el resultado indeseado del cambio de modelo de desarrollo "hacia adentro", que había existido hasta los años setenta, por otro "hacia fuera" que está orientado por las fuerzas de la producción y el comercio internacional que conocemos como globalización. El art

  4. Asymmetric transmission in prisms using structures and materials with isotropic-type dispersion.

    Science.gov (United States)

    Gundogdu, Funda Tamara; Serebryannikov, Andriy E; Cakmak, A Ozgur; Ozbay, Ekmel

    2015-09-21

    It is demonstrated that strong asymmetry in transmission can be obtained at the Gaussian beam illumination for a single prism based on a photonic crystal (PhC) with isotropic-type dispersion, as well as for its analog made of a homogeneous material. Asymmetric transmission can be realized with the aid of refraction at a proper orientation of the interfaces and wedges of the prism, whereas neither contribution of higher diffraction orders nor anisotropic-type dispersion is required. Furthermore, incidence toward a prism wedge can be used for one of two opposite directions in order to obtain asymmetry. Thus, asymmetric transmission is a general property of the prism configurations, which can be obtained by using simple geometries and quite conventional materials. The obtained results show that strong asymmetry can be achieved in PhC prisms with (nearly) circular shape of equifrequency dispersion contours, in both cases associated with the index of refraction 01. For the comparison purposes, results are also presented for solid uniform non-magnetic prisms made of a material with the same value of n. It is shown in zero-loss approximation that the PhC prism and the ultralow-index material prism (01. Possible contributions of scattering on the individual rods and diffraction on the wedge to the resulting mechanism are discussed. Analogs of unidirectional splitting and unidirectional deflection regimes, which are known from the studies of PhC gratings, are obtained in PhC prisms and solid uniform prisms, i.e. without higher diffraction orders.

  5. Contributions of Arctic PRISM to monitoring western hemispheric shorebirds

    Science.gov (United States)

    Skagen, Susan K.; Smith, Paul A.; Andres, Brad A.; Donaldson, Garry; Brown, Stephen

    2012-01-01

    for assessing its vulnerability and subsequent listing under the U.S. Endangered Species Act and the Canadian Species at Risk Act. To meet the need for information on population size and trends, shorebird biologists from Canada and the United States proposed a shared blueprint for shorebird monitoring across the Western Hemisphere in the late 1990s; this effort was undertaken in concert with the development of the Canadian and U.S. Shorebird Conservation Plans (Donaldson et al. 2000, Brown et aL 2001). Soon thereafter, partners in the monitoring effort adopted the name "Program for Regional and International Shorebird Monitoring" (PRISM). Among the primary objectives of PRISM were to estimate the population sizes and trends of breeding North American shorebirds and describe their distributions (Bart et al. 2002). PRISM members evaluated ongoing and potential monitoring approaches to address 74 taxa (including subspecies) and proposed a combination of arctic andboreal breeding surveys, temperate breeding and non-breeding surveys, and neotropical surveys.

  6. Foreword: Contributions of Arctic PRISM to monitoring western hemispheric shorebirds

    Science.gov (United States)

    Skagen, Susan K.; Smith, Paul A.; Andres, Brad A.; Donaldson, Garry; Brown, Stephen; Bart, Jonathan R.; Johnston, Victoria H.

    2012-01-01

    listing under the U.S. Endangered Species Act and the Canadian Species at Risk Act. To meet the need for information on population size and trends, shorebird biologists from Canada and the United States proposed a shared blueprint for shorebird monitoring across the Western Hemisphere in the late 1990s; this effort was undertaken in concert with the development of the Canadian and the U.S. Shorebird Conservation Plans. Soon thereafter, partners in the monitoring effort adopted the name "Program for Regional and International Shorebird Monitoring" (PRISM). Among the primary objectives of PRISM were to estimate the population sizes and trends of breeding North American shorebirds and describe their distributions. PRISM members evaluated ongoing and potential monitoring approached to address 74 taxa (including subspecies) and proposed a combination of arctic and boreal breeding surveys, temperate breeding and non-breeding surveys, and neotropical surveys.

  7. A VUV prism spectrometer for RICH radiator refractometry

    CERN Document Server

    Moyssides, P G; Fokitis, E

    2000-01-01

    A prism spectrometer has been developed to operate in the VUV wavelength range from 120 to 200 nm. It can be used as a pre- disperser in conjunction with a Fabry-Perot based gas refractometer. This instrument has also been used to measure the refractive index of the liquid radiator C/sub 6/F/sub 14/ in various spectral lines. This radiator is used in the RICH detectors of the DELPHI experiment and has been proposed for ALICE, and LHCb experiments. The spectral resolution of the system is improved as the wavelength decreases and the data are consistent with a wavelength accuracy about 0.4 nm at 140 nm. The results for the dispersion curve of the above liquid are presented. (17 refs).

  8. R&D proposal the prism plastic calorimeter:PPC

    CERN Document Server

    Dobrzynski, Ludwik; Marchand, P; Nédélec, P; Salin, P; CERN. Geneva. Detector Research and Development Committee

    1990-01-01

    This proposal supports two goals: First Goal_Demonstrate that current, widely used plastic technologies allow to design Prism Plastic Calorimeter (PPC) towers with a new "liquid crystal" type plastic called Vectra. It will be shown that this technique meets the requirements for a LHC calorimeter with warm liquids: safety, hermeticity, hadronic compensation, resolution and time response. Second Goal_ Describe how one can design a warm liquid calorimeter integrated into a LHC detector,and list the advantages of the PPC: low price, minimum of mechanical structures, minimum amount of dead space, easiness of mechanical assembly, accessibility to the electronics, possibility to recirculate the liquid. The absorber and the electronics being outside the liquid and easily accessible, one has maximum flexibility to define them. The R&D program we define here aims at showing the feasibility of these new ideas by building nine towers of twenty gaps and exposing them to electron and hadron beams.

  9. The clustering of quasars from an objective-prism survey

    International Nuclear Information System (INIS)

    Webster, A.

    1982-01-01

    The positions and redshifts of 108 quasars from the Cerro Tololo objective-prism survey are subjected to Fourier Power Spectrum Analysis in a search for clustering in their spatial distribution. It is found that, on the whole, these quasars are not clustered but are scattered in space independently at random. The sole exception is a group of four quasars at z = 0.37 which has a low probability of being a chance event and which, with a size of about 100 Mpc, may therefore be the largest known structure in the Universe. The conclusions disagree with Arp's analysis of this catalogue: his 'clouds of quasars' ejected by certain low-redshift galaxies, for example, are attributable to sensitivity variations among the different plates of the survey. It is shown that analysis of deeper surveys is likely to show up quasar clusters even at high redshift, and could therefore provide a useful new cosmological probe. (author)

  10. Safety and licensing analysis of 471 MWt PRISM reactor module

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.; Slovik, G.C.

    1991-01-01

    Independent analyses of unscrammed events postulated for the 471 MW t PRISM reactor module, as performed by Brookhaven National Laboratory for the U.S. Nuclear Regulatory Commission, are discussed. Peak fuel, cladding, and sodium temperatures for several postulated events were compared against reference temperatures. In general, BNL could essentially duplicate GE's analytical results, by making GE's assumptions. For the postulated unscrammed loss of flow (ULOF) events, the newly added Gas Expansion Modules (GEMs), have improved the passive shutdown response. With respect to the unscrammed loss of heat sink (ULOHS) event, there was little impact expected from the latest revisions, and little was found. For the unscrammed transient over-power (UTOP) events, uncertainties with respect to the behavior of ternary metal fuel leave unresolved the issue of how large a UTOP initiator (between 20 and 40 cents) may be acceptable. (author)

  11. FDS5 Simulation of PRISME INTEGRAL Test, PRSINT4

    International Nuclear Information System (INIS)

    Park, Jong Seok

    2012-01-01

    The reliance on fire modeling has playing a key role in the risk-informed and performance-based fire protection field. The ability to accurately predict fire behavior using the fire models is of high utility for hazard assessment, investigations and performance based design. Validation is the process of determining the degree of agreement between fire model outputs and real world events for one or more results of interest. The goal of validation is to quantify confidence in the predictive capability of the model. Validation in NUREG-1824 entails comparing the model prediction with full-scale fire experiments and quantifying the results. The objectives of this study, focused on the fire model validation, are to compare the FDS5 prediction results with the PRISME INTEGRAL test data and to validate FDS5 model

  12. Stakeholder theory and reporting information The case of performance prism

    Directory of Open Access Journals (Sweden)

    Bartłomiej Nita

    2016-07-01

    Full Text Available The aim of the paper is to explain the stakeholder theory in the context of performance measurement in integrated reporting. Main research methods used in the article include logical reasoning, critical analysis of academic literature, and observation. The principal result of the discussion is included in the statement that the stakeholder theory in the field of accounting is reflected in the so-called integrated reporting. Moreover, among the large variety of performance measurement methods, such as balanced scorecard and others, the concept of performance prism can be considered as the only method that fully takes into account the wide range of stakeholders. The analysis performed leads to the conclusion that development in accounting research takes into account the objectives of an organization in the context of the so-called corporate social responsibility as well as performance reporting oriented towards the communication of the company with its environment and the various stakeholder groups.

  13. [Costs of Chagas' disease screening test in blood donors in two Colombian blood banks, 2015].

    Science.gov (United States)

    Alvis, Nelson José; Díaz, Diana Patricia; Castillo, Liliana; Alvis, Nelson Rafael; Bermúdez, María Isabel; Berrío, Olga Maritza; Beltrán, Mauricio; Castañeda-Orjuela, Carlos Andrés

    2018-03-15

    Transfusion is a mechanism of transmission of Chagas' disease. There are no studies on the costs of the screening test in Colombian blood banks. To estimate the costs of the screening test for Chagas' disease among blood donors in two Colombian blood banks, 2015. We conducted a micro-costing study from the perspective of the health care provider to estimate the cost of Chagas' disease testing in two blood banks, Banco de Sangre de la Cruz Roja, Seccional Bolívar, and Banco de Sangre del Hospital de Yopal, Casanare, taking into account four cost categories: 1) Administrative costs: public services and insurance costs were calculated based on the blood bank area in square meters; 2) capital costs: building and equipment costs that were annualized using a 3% discount rate and a lifespan of 20 years for building and five for equipment; 3) costs of Chagas' disease test materials and reagents adjusted by blood bank production level, and 4) costs of staff in charge of Chagas' disease test processing. The costs of transfusion bagsand immunohematology tests are also reported. The cost of Chagas' disease test in the blood bank of Seccional Bolívar was COP$ 37,804 (USD$ 12), and the blood bag and immunohematology test costs were COP$ 25,941 (USD$ 8.2) and COP$ 6,800 (USD$ 2.2), respectively. In the blood bank of Yopal, Casanare, the costs were COP$ 77,384 (USD$ 24.6), COP$ 30,141 (USD$ 9.6) and COP$ 12,627 (USD$ 4), respectively. Personnel cost accounted for the highest percentage of the total cost for both blood banks (47.5% in Seccional Bolívar, and 55.7% in Yopal, Casanare). Our results are an important input for the planning of services and cost-effectiveness studies for screening tests for Chagas' disease in Colombian blood banks.

  14. Chagas' disease in the Amazon Basin: V. Periurban palms as habitats of Rhodnius robustus and Rhodnius pictipes - triatomine vectors of Chagas' disease

    Directory of Open Access Journals (Sweden)

    M. A. Miles

    1983-12-01

    Full Text Available Trypanosoma cruzi infected Rhodnius robustus and/or Rhodnius pictipes were commonly found, in large numbers, in the Brazilian Amazonian palms Maximiliana regia ("inajá", Acrocomia sclerocarpa ("mucajá" and Orbignya speciosa ("babaçu". The common opossum, Didelphis marsupialis, was the animal most frequently associated with triatomine infested palms. R. pictipes, frequently light-attracted into houses from palm trees, was the probable source of an acute case of Chagas' disease in the vicinity of Belém. It is considered that triatomine infested palms are likely to cause some cases of acute Chagas' disease in the States of Amazonas and Rondônia. Possible control methods are suggested.Rhodnius robustus e/ou Rhodnius pictipes, infectados com Trypanosoma cruzi foram comumente encontrados, em grande numero, nas palmeiras Maximiliana regia (inaja, Acrocomia sclerocarpa (mucaja e Orbignya speciosa (babacu na Amazonia brasileira. O marsupial Didelphis marsupialis foi o animal encontrado mais frequentemente nas palmeiras associadas a alta prevalencia de triatomineos. R. pictipes que e atraido pela luz nas residencias de palmeiras vizinhas, provavelmente e a fonte de um caso agudo de doenca de Chagas nas vizinhancas de Belem. Sugere-se que as palmeiras albergando triatomineos poderiam ser relacionadas com infeccoes humanas de doenca de Chagas nos Estados de Amazonas e Rondonia. Sugere-se, tambem, possiveis metodos de controle.

  15. La enfermedad de Chagas en las Américas: una perspectiva de ecosalud Chagas disease in the Americas: an ecohealth perspective

    Directory of Open Access Journals (Sweden)

    Roberto Briceño-León

    2009-01-01

    Full Text Available El proceso de transmisión de la enfermedad de Chagas ha estado históricamente relacionado con los patrones de ocupación territorial de los asentamientos humanos. En las áreas rurales puede ocurrir más fácilmente el encuentro del vector, los agentes patógenos y los seres humanos, por las condiciones de la vivienda y la pobreza existente en estas zonas. Los procesos migratorios permanentes o estacionales han jugado un papel igualmente importante en el transporte de los vectores y en la infección de la población en las zonas urbanas. Las nuevas fronteras agrícolas del Amazonas se han establecido nuevas áreas de transmisión de la enfermedad. La atención dada a los bancos de sangre ha permitido disminuir la transmisión transfusional, pero la inmigración internacional ha cambiado la situación epidemiológica, pues en Estados Unidos y España viven miles de enfermos que habían sido infectados décadas antes y no encuentran adecuada atención. Los avances en el conocimiento y el control de la enfermedad son mostrados en el artículo, señalando las limitaciones existentes en cuanto al mejoramiento de las condiciones ambientales y de vivienda de los pobres.The historical processes involved in Chagas disease transmission relate to the patterns and conditions of human settlements, especially in rural areas, due to proximity to forest areas, where both vectors and Trypanosoma cruzi can occur, combined with precarious housing conditions and underlying poverty. However, seasonal and permanent rural-urban migration has played a major role in re-mobilizing vectors, T. cruzi, and Chagas-infected individuals. A new agricultural frontier in the Amazon has led to a new transmission pattern, especially with palm trees located close to houses. Improved blood bank surveillance has decreased transmission by blood transfusions. International migration also plays a role in Chagas disease epidemiology. The United States and Spain, where specific health

  16. Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result

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    Jacques Luauté

    2012-01-01

    Full Text Available Adaptation to right-deviating prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of prism adaptation on left neglect, the present study evaluated the effect of left-deviating prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after prism adaptation. These results suggest that the therapeutic effect of prism adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for prism adaptation both in terms of the side of the visuomanual adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed.

  17. Jones matrix formulation of a Porro prism laser resonator with waveplates: theoretical and experimental analysis

    Science.gov (United States)

    Agrawal, L.; Bhardwaj, A.; Pal, S.; Kumar, A.

    2007-11-01

    This article presents the results of a detailed theoretical and experimental analysis carried out on a folded Z-shaped polarization coupled, electro-optically Q-switched laser resonator with Porro prisms and waveplates. The advantages of adding waveplates in a Porro prism resonator have been explored for creating high loss condition prior to Q-switching and obtaining variable reflectivity with fixed orientation of Porro prism. Generalized expressions have been derived in terms of azimuth angles and phase shifts introduced by the polarizing elements. These expressions corroborate with known reported results under appropriate substitutions. A specific case of a crossed Porro prism diode-pumped Nd:YAG laser has been theoretically and experimentally investigated. In the feedback arm, a 0.57λ waveplate oriented at 135° completely compensates the phase shift of a fused silica Porro prism and provides better tolerances than a BK-7 prism/0.60λ waveplate combination to stop prelasing. The fused silica prism/0.57λ combination with waveplate at 112° acts like a 100% mirror and was utilized for optimization of free running performance. The effective reflectivity was determined for various orientations of the quarter waveplate in the gain arm to numerically estimate the Q-switched laser pulse parameters through rate equation analysis. Experimental results match well with the theoretical analysis.

  18. Multi-energy CT based on a prior rank, intensity and sparsity model (PRISM)

    International Nuclear Information System (INIS)

    Gao, Hao; Osher, Stanley; Yu, Hengyong; Wang, Ge

    2011-01-01

    We propose a compressive sensing approach for multi-energy computed tomography (CT), namely the prior rank, intensity and sparsity model (PRISM). To further compress the multi-energy image for allowing the reconstruction with fewer CT data and less radiation dose, the PRISM models a multi-energy image as the superposition of a low-rank matrix and a sparse matrix (with row dimension in space and column dimension in energy), where the low-rank matrix corresponds to the stationary background over energy that has a low matrix rank, and the sparse matrix represents the rest of distinct spectral features that are often sparse. Distinct from previous methods, the PRISM utilizes the generalized rank, e.g., the matrix rank of tight-frame transform of a multi-energy image, which offers a way to characterize the multi-level and multi-filtered image coherence across the energy spectrum. Besides, the energy-dependent intensity information can be incorporated into the PRISM in terms of the spectral curves for base materials, with which the restoration of the multi-energy image becomes the reconstruction of the energy-independent material composition matrix. In other words, the PRISM utilizes prior knowledge on the generalized rank and sparsity of a multi-energy image, and intensity/spectral characteristics of base materials. Furthermore, we develop an accurate and fast split Bregman method for the PRISM and demonstrate the superior performance of the PRISM relative to several competing methods in simulations. (papers)

  19. Effects of Accretionary Prisms on 3-D Long-Period Ground Motion Simulations

    Science.gov (United States)

    Guo, Y.; Koketsu, K.; Miyake, H.

    2014-12-01

    The accretionary prism along the subduction zones such as the Middle America trench or the Nankai trough is considered as an important factor affecting the generation and propagation of long-period ground motions. In Japan, the great earthquake along the Nankai subduction zone which is expected to occur in the near future can generate large long-period ground motions in the metropolitan areas such as Osaka, Nagoya and Tokyo. To investigate the effect of accretionary prism on long-period ground motions, we performed simulations of long-period ground motions for the event (Mw 7.1) that occurred off the Kii peninsula, Japan, at 10:07 on 5 September 2004 (UTC). Our simulation model ranged from the Kinki region to the Kanto region, and included the Osaka, Nobi and Kanto basin. We calculated long-period ground motions for four types of 3-D velocity structure models: (a) model with the accretionary prism (reference model), (b) model where accretionary prism has different 3-D geometry from the reference model, (c) model with the accretionary prism whose velocity, density and Q-value are shifted, (d) model without the accretionary prism. We compared the waveforms calculated for these models and concluded that the accretionary prism along the Nankai subduction zone plays roles in reducing the amplitude of direct waves and extending the duration of coda waves. This is attributed to the trap effect of accretionary prism. Our simulation also suggested that, the edge geometry along the landward side of accretionary prism has major effects on the processes of generation and propagation of long-period ground motions.

  20. Optimization of SPR signals: Monitoring the physical structures and refractive indices of prisms

    Directory of Open Access Journals (Sweden)

    Mukhtar Wan Maisarah

    2017-01-01

    Full Text Available Surface plasmon resonance (SPR can only be achieved if sufficient energy is provided at the boundary between metal and dielectric. An employment of prism as a light coupler by using Kretschmann configuration is one of the alternative for the production of adequate energy to be generated as surface plasmon polaritons (SPP. This work is carried out to investigate the effect of physical structure of the prism and its refractive index to the excitation of SPPs. A 50nm gold thin metal film with dielectric constant of ɛ=-12.45i+1.3 was deposited on the hypotenuse surface of the prisms. The physical structures of the prisms were varied such as triangular, conical, hemispherical and half cylindrical. These prisms were classified into two types of refractive indices (RI, namely n=1.51(type BK7 and n=1.77(type SF11. Based on SPR curve analyses, we discovered that strong SPR signals which consist of 82.98% photons were excited as SPPs can be obtained by using type-BK7 prism with physical structures of hemispherical or half cylindrical. From the view of selectivity ability as sensors, the usage of type-SF11 prisms (half cylindrical and hemispherical able to enhance this impressive feature in which sharp SPR curves with small FWHM values were obtained. In conclusion, apart from properties of thin film materials, the physical structure of prisms and their RI values play crucial roles to obtain optimum SPR signal. High sensitivity SPR sensor can be established with the appointment of type-BK7 prisms (hemispherical or half cylindrical shape as light couplers.

  1. Optimization of SPR signals: Monitoring the physical structures and refractive indices of prisms

    Science.gov (United States)

    Maisarah Mukhtar, Wan; Halim, Razman Mohd; Hassan, Hazirah

    2017-11-01

    Surface plasmon resonance (SPR) can only be achieved if sufficient energy is provided at the boundary between metal and dielectric. An employment of prism as a light coupler by using Kretschmann configuration is one of the alternative for the production of adequate energy to be generated as surface plasmon polaritons (SPP). This work is carried out to investigate the effect of physical structure of the prism and its refractive index to the excitation of SPPs. A 50nm gold thin metal film with dielectric constant of ɛ=-12.45i+1.3 was deposited on the hypotenuse surface of the prisms. The physical structures of the prisms were varied such as triangular, conical, hemispherical and half cylindrical. These prisms were classified into two types of refractive indices (RI), namely n=1.51(type BK7) and n=1.77(type SF11). Based on SPR curve analyses, we discovered that strong SPR signals which consist of 82.98% photons were excited as SPPs can be obtained by using type-BK7 prism with physical structures of hemispherical or half cylindrical. From the view of selectivity ability as sensors, the usage of type-SF11 prisms (half cylindrical and hemispherical) able to enhance this impressive feature in which sharp SPR curves with small FWHM values were obtained. In conclusion, apart from properties of thin film materials, the physical structure of prisms and their RI values play crucial roles to obtain optimum SPR signal. High sensitivity SPR sensor can be established with the appointment of type-BK7 prisms (hemispherical or half cylindrical shape) as light couplers.

  2. Triatominae Biochemistry Goes to School: Evaluation of a Novel Tool for Teaching Basic Biochemical Concepts of Chagas Disease Vectors

    Science.gov (United States)

    Cunha, Leonardo Rodrigues; de Oliveria Cudischevitch, Cecília; Carneiro, Alan Brito; Macedo, Gustavo Bartholomeu; Lannes, Denise; da Silva-Neto, Mário Alberto Cardoso

    2014-01-01

    We evaluate a new approach to teaching the basic biochemistry mechanisms that regulate the biology of Triatominae, major vectors of "Trypanosoma cruzi," the causative agent of Chagas disease. We have designed and used a comic book, "Carlos Chagas: 100 years after a hero's discovery" containing scientific information obtained by…

  3. Epilepsia e doença de chagas cronica

    Directory of Open Access Journals (Sweden)

    Edymar Jardim

    1981-03-01

    Full Text Available A síndrome epiléptica em chagásicos crônicos, foi referida raramente na literatura especializazda, não tendo sido feito até o momento, um estudo detalhado das suas manifestações. Partindo-se da premissa de que a moléstia de Chagas tem por substrato anatômico uma destruição neuronal, procurou-se comparar dois grupos de epilépticos, um dos quais com moléstia de Chagas crônica. Foram estudados 167 pacientes epilépticos, dos quais 44 eram comprovadamente chagásicos. O estudo permitiu coletar dados referentes à procedência dos pacientes, resultado soro-lógico, sexo, idade, época de incidência das manifestações epilépticas, elementos dos exames neurológicos, do líquido cefalorraqueano, eletrencefalográfico e os resultados da terapêutica anticonvulsivante. Como resultados principais destacamos o início tardio da epilepsia nos chagásicos, e o predomínio acentuado das crises parciais com sintomatologia elementar de tipo autonômico. O exame neurológico e o do líquido cefalorraqueano, apesar de apresentarem percentualmente nos seus resultados, taxas moderadamente mais elevadas na incidência de alterações, não caracterizaram síndromes neurológicas bem definidas. O exame eletrencefalográfico, revelou alterações sugestivas de comprometimento orgânico cerebral difuso. A terapêutica anticonvulsivante, baseada na utilização de hidantoinatos, barbitúricos, primidona e benzodiazepínicos, mostrou que o controle das crises foi mais difícil nos chagásicos, exigindo maiores quantidades de medicação, com resultados menos satisfatórios.

  4. Scintigraphy for the detection of myocardial damage in the indeterminate form of Chagas disease

    International Nuclear Information System (INIS)

    Pedroso, Enio Roberto Pietra; Rezende, Nilton Alves de

    2010-01-01

    Background: non-invasive cardiological methods have been used for the identification of myocardial damage in Chagas disease. Objective: to verify whether the rest/stress myocardial perfusion scintigraphy is able to identify early myocardial damage in the indeterminate form of Chagas disease. Methods: eighteen patients with the indeterminate form of Chagas Disease and the same number of normal controls, paired by sex and age, underwent rest/stress myocardial scintigraphy using sestamibi-99mTc, aiming at detecting early cardiac damage. Results: the results did not show perfusion or ventricular function defects in patients at the indeterminate phase of Chagas disease and in the normal controls, except for a patient who presented signs of ventricular dysfunction in the myocardial perfusion scintigraphy with electrocardiographic gating. Conclusion: the results of this study, considering the small sample size, showed that the rest/stress myocardial scintigraphy using sestamibi-99mTc is not an effective method to detect early myocardial alterations in the indeterminate form of Chagas disease (author)

  5. Scintigraphy for the detection of myocardial damage in the indeterminate form of Chagas disease

    Energy Technology Data Exchange (ETDEWEB)

    Pedroso, Enio Roberto Pietra; Rezende, Nilton Alves de, E-mail: narezende@terra.com.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Medicina; Abuhid, Ivana Moura [Instituto de Medicina Nuclear e Diagnostico Molecular, Belo Horizonte, MG (Brazil)

    2010-07-15

    Background: non-invasive cardiological methods have been used for the identification of myocardial damage in Chagas disease. Objective: to verify whether the rest/stress myocardial perfusion scintigraphy is able to identify early myocardial damage in the indeterminate form of Chagas disease. Methods: eighteen patients with the indeterminate form of Chagas Disease and the same number of normal controls, paired by sex and age, underwent rest/stress myocardial scintigraphy using sestamibi-99mTc, aiming at detecting early cardiac damage. Results: the results did not show perfusion or ventricular function defects in patients at the indeterminate phase of Chagas disease and in the normal controls, except for a patient who presented signs of ventricular dysfunction in the myocardial perfusion scintigraphy with electrocardiographic gating. Conclusion: the results of this study, considering the small sample size, showed that the rest/stress myocardial scintigraphy using sestamibi-99mTc is not an effective method to detect early myocardial alterations in the indeterminate form of Chagas disease (author)

  6. Association of caspase-1 polymorphisms with Chagas cardiomyopathy among individuals in Santa Cruz, Bolivia.

    Science.gov (United States)

    Fu, Katherine Yih-Jia; Zamudio, Roxana; Henderson-Frost, Jo; Almuedo, Alex; Steinberg, Hannah; Clipman, Steven Joseph; Duran, Gustavo; Marcus, Rachel; Crawford, Thomas; Alyesh, Daniel; Colanzi, Rony; Flores, Jorge; Gilman, Robert Hugh; Bern, Caryn

    2017-01-01

    Trypanosoma cruzi (Tc) infection is usually acquired in childhood in endemic areas, leading to Chagas disease, which progresses to Chagas cardiomyopathy in 20-30% of infected individuals over decades. The pathogenesis of Chagas cardiomyopathy involves the host inflammatory response to T. cruzi, in which upstream caspase-1 activation prompts the cascade of inflammatory chemokines/cytokines, cardiac remodeling, and myocardial dysfunction. The aim of the present study was to examine the association of two caspase-1 single nucleotide polymorphisms (SNPs) with cardiomyopathy. We recruited infected (Tc+, n = 149) and uninfected (Tc-, n = 87) participants in a hospital in Santa Cruz, Bolivia. Cardiac status was classified (I, II, III, IV) based on Chagas cardiomyopathy-associated electrocardiogram findings and ejection fractions on echocardiogram. Genotypes were determined using Taqman probes via reverse transcription-polymerase chain reaction of peripheral blood DNA. Genotype frequencies were analyzed according to three inheritance patterns (dominant, recessive, additive) using logistic regression adjusted for age and sex. The AA allele for the caspase-1 SNP rs501192 was more frequent in Tc+ cardiomyopathy (classes II, III, IV) patients compared to those with a normal cardiac status (class I) [odds ratio (OR) = -2.18, p = 0.117]. This trend approached statistical significant considering only Tc+ patients in class I and II (OR = -2.64, p = 0.064). Caspase-1 polymorphisms may play a role in Chagas cardiomyopathy development and could serve as markers to identify individuals at higher risk for priority treatment.

  7. Controlled but not cured: Structural processes and explanatory models of Chagas disease in tropical Bolivia.

    Science.gov (United States)

    Forsyth, Colin

    2015-11-01

    Dressler (2001:456) characterizes medical anthropology as divided between two poles: the constructivist, which focuses on the "meaning and significance that events have for people," and the structuralist, which emphasizes socioeconomic processes and relationships. This study synthesizes structuralist and constructivist perspectives by investigating how structural processes impact explanatory models of Chagas disease in a highly endemic area. The research took place from March-June 2013 through the Centro Medico Humberto Parra, a non-profit clinic servicing low income populations in Palacios, Bolivia and surrounding communities. Semistructured interviews (n = 68) and consensus analysis questionnaires (n = 48) were administered to people dealing with Chagas disease. In the interview narratives, respondents link Chagas disease with experiences of marginalization and rural poverty, and describe multilayered impediments to accessing treatment. They often view the disease as incurable, but this reflects inconsistent messages from the biomedical system. The consensus analysis results show strong agreement on knowledge of the vector, ethnomedical treatment, and structural factors related to Chagas disease. In interpreting Chagas disease, respondents account for the structural factors which place them at risk and impede access to care. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Chagas Disease Knowledge and Risk Behaviors of the Homeless Population in Houston, TX.

    Science.gov (United States)

    Ingber, Alexandra; Garcia, Melissa N; Leon, Juan; Murray, Kristy O

    2018-04-01

    Chagas disease is a parasitic infection, caused by Trypanosoma cruzi, endemic in Latin America. Sylvatic T. cruzi-infected triatomine vectors are present in rural and urban areas in the southern USA and may transmit T. cruzi infection to at-risk populations, such as homeless individuals. Our study aimed to evaluate Chagas disease knowledge and behaviors potentially associated with transmission risk of Chagas disease among Houston, Texas' homeless population by performing interviews with 212 homeless individuals. The majority of the 212 surveyed homeless individuals were male (79%), African-American (43%), American-born individuals (96%). About 30% of the individuals reported having seen triatomines in Houston, and 25% had evidence of blood-borne transmission risk (IV drug use and/or unregulated tattoos). The median total time homeless was significantly associated with recognition of the triatomine vector. Our survey responses indicate that the homeless populations may exhibit potential risks for Chagas disease, due to increased vector exposure, and participation in blood-borne pathogen risk behaviors. Our findings warrant additional research to quantify the prevalence of Chagas disease among homeless populations.

  9. Fault structure, properties and activity of the Makran Accretionary Prism and implications for seismogenic potential

    Science.gov (United States)

    Smith, G. L.; McNeill, L. C.; Henstock, T.; Bull, J. M.

    2011-12-01

    The Makran subduction zone is the widest accretionary prism in the world (~400km), generated by convergence between the Arabian and Eurasian tectonic plates. It represents a global end-member, with a 7km thick incoming sediment section. Accretionary prisms have traditionally been thought to be aseismic due to the presence of unconsolidated sediment and elevated basal pore pressures. The seismogenic potential of the Makran subduction zone is unclear, despite a Mw 8.1 earthquake in 1945 that may have been located on the plate boundary beneath the prism. In this study, a series of imbricate landward dipping (seaward verging) thrust faults have been interpreted across the submarine prism (outer 70 km) using over 6000km of industry multichannel seismic data and bathymetric data. A strong BSR (bottom simulating reflector) is present throughout the prism (excluding the far east). An unreflective décollement is interpreted from the geometry of the prism thrusts. Two major sedimentary units are identified in the input section, the lower of which contains the extension of the unreflective décollement surface. Between 60%-100% of the input section is currently being accreted. The geometry of piggy-back basin stratigraphy shows that the majority of thrusts, including those over 50km from the trench, are recently active. Landward thrusts show evidence for reactivation after periods of quiescence. Negative polarity fault plane reflectors are common in the frontal thrusts and in the eastern prism, where they may be related to increased fault activity and fluid expulsion, and are rarer in older landward thrusts. Significant NE-SW trending basement structures (The Murray Ridge and Little Murray Ridge) on the Arabian plate intersect the deformation front and affect sediment input to the subduction zone. Prism taper and structure are apparently primarily controlled by sediment supply and the secondary influence of subducting basement ridges. The thick, likely distal, sediment

  10. PRISM software—Processing and review interface for strong-motion data

    Science.gov (United States)

    Jones, Jeanne M.; Kalkan, Erol; Stephens, Christopher D.; Ng, Peter

    2017-11-28

    Rapidly available and accurate ground-motion acceleration time series (seismic recordings) and derived data products are essential to quickly providing scientific and engineering analysis and advice after an earthquake. To meet this need, the U.S. Geological Survey National Strong Motion Project has developed a software package called PRISM (Processing and Review Interface for Strong-Motion data). PRISM automatically processes strong-motion acceleration records, producing compatible acceleration, velocity, and displacement time series; acceleration, velocity, and displacement response spectra; Fourier amplitude spectra; and standard earthquake-intensity measures. PRISM is intended to be used by strong-motion seismic networks, as well as by earthquake engineers and seismologists.

  11. An in-silico investigation of anti-Chagas phytochemicals.

    Science.gov (United States)

    McCulley, Stephanie F; Setzer, William N

    2014-01-01

    Over 18 million people in tropical and subtropical America are afflicted by American trypanosomiasis or Chagas disease. In humans, symptoms of the disease include fever, swelling, and heart and brain damage, usually leading to death. There is currently no effective treatment for this disease. Plant products continue to be rich sources of clinically useful drugs, and the biodiversity of the Neotropics suggests great phytomedicinal potential. Screening programs have revealed numerous plant species and phytochemical agents that have shown in-vitro or in-vivo antitrypanosomal activity, but the biochemical targets of these phytochemicals are not known. In this work, we present a molecular docking analysis of Neotropical phytochemicals, which have already demonstrated antiparasitic activity against Trypanosoma cruzi, with potential druggable protein targets of the parasite. Several protein targets showed in-silico selectivity for trypanocidal phytochemicals, including trypanothione reductase, pteridine reductase 2, lipoamide dehydrogenase, glucokinase, dihydroorotate dehydrogenase, cruzain, dihydrofolate-reductase/thymidylate-synthase, and farnesyl diphosphate synthase. Some of the phytochemical ligands showed notable docking preference for trypanothione reductase, including flavonoids, fatty-acid-derived oxygenated hydrocarbons, geranylgeraniol and the lignans ganschisandrine and eupomatenoid-6.

  12. Chagas Cardiomyopathy in New Orleans and the Southeastern United States.

    Science.gov (United States)

    Hsu, Robert C; Burak, Joshua; Tiwari, Sumit; Chakraborti, Chayan; Sander, Gary E

    2016-01-01

    Chagas disease (CD), caused by Trypanosoma cruzi, affects 6-7 million people worldwide annually, primarily in Central and South America, and >300,000 people in the United States. CD consists of acute and chronic stages. Hallmarks of acute CD include fever, myalgia, diaphoresis, hepatosplenomegaly, and myocarditis. Symptoms of chronic CD include pathologic involvement of the heart, esophagus, and colon. Myocardial involvement is identifiable by electrocardiogram and cardiac magnetic resonance imaging showing inflammation and left ventricular wall functional abnormalities. We present two cases of CD identified in a single hospital in the Southeastern United States. Case 1 presents a patient with symptoms of anginal chest pain and associated shortness of breath with myocardial involvement suggestive of ischemic infarction but normal coronary arteries. Case 2 describes a patient with no physical symptoms and echocardiogram with ejection fraction of 50% with posterolateral and anterolateral wall hypokinesis but normal coronary arteries. With a growing number of immigrants from Central and South America in the United States, it is imperative for clinicians to include CD as part of the differential diagnosis for patients presenting with heart disease who have a history of exposure to T. cruzi endemic areas.

  13. Biosensors to Diagnose Chagas Disease: A Brief Review.

    Science.gov (United States)

    Rocha-Gaso, María-Isabel; Villarreal-Gómez, Luis-Jesús; Beyssen, Denis; Sarry, Frédéric; Reyna, Marco-Antonio; Ibarra-Cerdeña, Carlos-Napoleón

    2017-11-15

    Chagas disease (CD), which mostly affects those living in deprived areas, has become one of Latin America's main public health problems. Effective prevention of the disease requires early diagnosis, initiation of therapy, and regular blood monitoring of the infected individual. However, the majority of the Trypanosoma cruzi infections go undiagnosed because of mild symptoms, limited access to medical attention and to a high variability in the sensitivity and specificity of diagnostic tests. Consequently, more affordable and accessible detection technologies capable of providing early diagnosis and T. cruzi load measurements in settings where CD is most prevalent are needed to enable enhanced intervention strategies. This work analyzes the potential contribution of biosensing technologies, reviewing examples that have been tested and contrasted with traditional methods, both serological and parasitological (i.e., molecular detection by PCR), and discusses some emerging biosensing technologies that have been applied for this public health issue. Even if biosensing technologies still require further research efforts to develop portable systems, we arrive at the conclusion that biosensors could improve the accuracy of CD diagnosis and the follow-up of patients' treatments in terms of the rapidity of results, small sample volume, high integration, ease of use, real-time and low cost detection when compared with current conventional technologies.

  14. Chagas Disease Vector Control in Tupiza, Southern Bolivia

    Directory of Open Access Journals (Sweden)

    G Guillen

    1997-01-01

    Full Text Available Heavy domestic and peridomestic infestations of Triatoma infestans were controlled in two villages in southern Bolivia by the application of deltamethrin SC25 (2.5% suspension concentrate at a target dose of 25 mg a.i./m². Actual applied dose was monitored by HPLC analysis of filter papers placed at various heights on the house walls, and was shown to range from 0 to 59.6 about a mean of 28.5 mg a.i./m². Wall bioassays showed high mortality of T. infestans during the first month after the application of deltamethrin. Mortality declined to zero as summer temperatures increased, but reappeared with the onset of the following winter. In contrast, knockdown was apparent throughout the trial, showing no discernible temperature dependence. House infestation rates, measured by manual sampling and use of paper sheets to collect bug faeces, declined from 79% at the beginning of the trial to zero at the 6 month evaluation. All but one of the houses were still free of T. infestans at the final evaluation 12 months after spraying, although a small number of bugs were found at this time in 5 of 355 peridomestic dependencies. Comparative cost studies endorse the recommendation of large-scale application of deltamethrin, or pyrethroid of similar cost-effectiveness, as a means to eliminate domestic T. infestans populations in order to interrupt transmission of Chagas disease

  15. Urbanization, land tenure security and vector-borne Chagas disease

    Science.gov (United States)

    Levy, Michael Z.; Barbu, Corentin M.; Castillo-Neyra, Ricardo; Quispe-Machaca, Victor R.; Ancca-Juarez, Jenny; Escalante-Mejia, Patricia; Borrini-Mayori, Katty; Niemierko, Malwina; Mabud, Tarub S.; Behrman, Jere R.; Naquira-Velarde, Cesar

    2014-01-01

    Modern cities represent one of the fastest growing ecosystems on the planet. Urbanization occurs in stages; each stage characterized by a distinct habitat that may be more or less susceptible to the establishment of disease vector populations and the transmission of vector-borne pathogens. We performed longitudinal entomological and epidemiological surveys in households along a 1900 × 125 m transect of Arequipa, Peru, a major city of nearly one million inhabitants, in which the transmission of Trypanosoma cruzi, the aetiological agent of Chagas disease, by the insect vector Triatoma infestans, is an ongoing problem. The transect spans a cline of urban development from established communities to land invasions. We find that the vector is tracking the development of the city, and the parasite, in turn, is tracking the dispersal of the vector. New urbanizations are free of vector infestation for decades. T. cruzi transmission is very recent and concentrated in more established communities. The increase in land tenure security during the course of urbanization, if not accompanied by reasonable and enforceable zoning codes, initiates an influx of construction materials, people and animals that creates fertile conditions for epidemics of some vector-borne diseases. PMID:24990681

  16. Study of the hypothalamic - hypophyseal - thyroid axis by the administration of TRH to Chagas' disease patients

    International Nuclear Information System (INIS)

    Abelin, N.M.A.

    1978-01-01

    The TSH and T 3 response to synthetic TRH was evaluated in two groups of patients: normal and with Chagas' disease, from the urban area of Sao Paulo (Brazil). Plasma T 4 , PBI and TSH values were within the normal range, when compared with those found in the controls: So were the thyroid uptakes of 2 and 24 hours; the basal levels of T 3 where within the normal range except in three subjects whose values were higher than normal. After TRH administration the amount of TSH secretion in patients with Chagas' disease was increased when compared to normal ones, while T 3 secretion was unaltered. It is suggested that in the Chagas' disease there is an increase in the pituitary TSH, while the thyroid reserve is preserved. This increase could be due to a difference in the regulation rate of TRH, which is determined by the neuronal degeneration caused by the disease itself. (author) [pt

  17. [What is not searched, it is difficult to find: Chagas' disease].

    Science.gov (United States)

    Briceno, Luis; Mosca, Walter

    2016-05-01

    A conservative estimation indicates that more than 400 000 Latin American immigrants are living in Italy. Several studies have shown that among these, the prevalence of Chagas disease is between 3.9% and 17%, so it is not unlikely to find a patient with this disease during a cardiology visit. How many patients from Latin America are diagnosed with heart failure in Italy and no one has ever thought about a possible Chagas disease? This brief review describes the situation of the disease in Italy, its characteristics, the etiology of this disease and its treatment. The latter aspect will be discussed considering the recent published results of the BENEFIT study, where it was found that treatment with benznidazole in patients with Chagas' cardiomyopathy is able to reduce significantly the detection of parasites in the blood, but it is not able to prevent clinical deterioration during 5 years of follow-up. The possible implications of these results will be discussed.

  18. [Control of Chagas disease in pregnant Latin-American women and her children].

    Science.gov (United States)

    Merino, Francisco J; Martínez-Ruiz, Rocío; Olabarrieta, Iciar; Merino, Paloma; García-Bujalance, Silvia; Gastañaga, Teresa; Flores-Chavez, María

    2013-09-01

    Chagas disease is a chronic and systemic infection caused by Trypanosoma cruzi. According to estimates from WHO, 10 million people are affected by this parasite. In the last years, birthrate among the immigrant women from Latin America settled in the Comunidad Autónoma de Madrid has been increasing, and as T. cruzi can be transmitted from mother to child, in fact 11 cases of congenital Chagas disease have been confirmed. Therefore, the aim of this paper is encouraging improvements in the coverage of the anti-T. cruzi antibodies detection in pregnant women from endemic areas. By this strategy, an active search for infected pregnant women and early detection of her infected newborns could be conducted, and then an early specific treatment could be administrated. Thus, there could be an important contribution to the control of Chagas disease in non-endemic area.

  19. Forward and inverse solutions for Risley prism based on the Denavit-Hartenberg methodology

    Science.gov (United States)

    Beltran-Gonzalez, A.; Garcia-Torales, G.; Strojnik, M.; Flores, J. L.; Garcia-Luna, J. L.

    2017-08-01

    In this work forward and inverse solutions for two-element Risley prism for pointing and scanning beam systems are developed. A more efficient and faster algorithm is proposed to make an analogy of the Risley prism system compared with a robotic system with two degrees of freedom. This system of equations controls each Risley prism individually as a planar manipulator arm of two links. In order to evaluate the algorithm we implement it in a pointing system. We perform popular routines such as the linear, spiral and loops traces. Using forward and inverse solutions for two-element Risley prism it is also possible to point at coordinates specified by the user, provided they are within the pointer area of work area. Experimental results are showed as a validation of our proposal.

  20. Accurate geometrical optics model for single-lens stereovision system using a prism.

    Science.gov (United States)

    Cui, Xiaoyu; Lim, Kah Bin; Guo, Qiyong; Wang, DaoLei

    2012-09-01

    In this paper, we proposed a new method for analyzing the image formation of a prism. The prism was considered as a single optical system composed of some planes. By analyzing each plane individually and then combining them together, we derived a transformation matrix which can express the relationship between an object point and its image by the refraction of a prism. We also explained how to use this matrix for epipolar geometry and three-dimensional point reconstruction. Our method is based on optical geometry and could be used in a multiocular prism. Experimentation results are presented to prove the accuracy of our method is better than former researchers' and is comparable with that of the multicamera stereovision system.

  1. Improvement of Mental Imagery after Prism Exposure in Neglect: A Case Study

    Directory of Open Access Journals (Sweden)

    Gilles Rode

    1999-01-01

    Full Text Available Previous work has shown that various symptoms of unilateral neglect, including the pathological shift of the subjective midline to the right, may be improved by a short adaptation period to a prismatic shift of the visual field to the right. We report here the improvement of imagined neglect after prism exposure in a patient with a left unilateral neglect. Despite a strong neglect observed for mental images as well as for conventional tests, the mental evocation of left-sided information from an internal image of the map of France map was fully recovered following prism adaptation to the right. This improvement could not be explained by the alteration of visuomotor responses induced by the prism adaptation. Prism adaptation may therefore act not only on sensory-motor levels but also on a higher cognitive level of mental space representation and/or exploration.

  2. Aspectos neurológicos da moléstia de chagas

    Directory of Open Access Journals (Sweden)

    Fritz Köberle

    1967-09-01

    Full Text Available Carlos Chagas related in more than two 200 cases, what he called "nervous forms" of trypanosomiasis, that is neurological manifestations from central origin (idiotism, infantilism, pseudo-bulbar paralysis, aphasia, cerebellar ataxia, atetosis, espostic or paralytic diplegia, disbasia. At that time Chagas expressed his concepts as follows: "In relation to the frequency of trypanosomiasis nervous forms we have performed many observations which allow us to state that this disease is the one which causes the largest number of organic affections of the central nervous system, in human pathology". We are plenty convinced by Chagas's statement. By experiments on animals of laboratory we have very often noticed a rather varied neurological symptomatology, being worth point out identical syndromes to those observed by Chagas. Our autopsy material non-rarely include chronic Chagas cases presenting a most varied symtomatology. Among them we have named only three cases of discerebral nanism, a rather rare affection in other parts of the world and relatively frequent in our material. The fact which we have demonstrated, i.e., a relatively great decreasing of number of nervous cells in the peripheral system could happen in the central nervous system as well. Provided that there are only two quantitative works on neuron number diminishing in the central nervous system in mice and rats we decline to go into further details about central neuropathies in man. We emphasized the necessity to perform researches on this field by means of intimate collaboration between clinicians and pathologists, as the only way to confirm on scientific basis all that was observed by the panoramic and genial vision of Carlos Chagas.

  3. Chagas Disease Infection among Migrants at the Mexico/Guatemala Border.

    Science.gov (United States)

    Conners, Erin E; Ordoñez, Teresa López; Cordon-Rosales, Celia; Casanueva, Carmen Fernández; Miranda, Sonia Morales; Brouwer, Kimberly C

    2017-10-01

    Chagas disease results in the largest burden, in terms of disability-adjusted-life-years, of any parasitic disease in the Americas. Monitoring Chagas disease among migrants is critical to controlling its spread and to serving the needs of the migrant community. Therefore, we determined the prevalence and correlates of Chagas disease in regional and international migrant populations at the Mexico/Guatemala border. Data were collected as part of a larger study of human immunodeficiency virus (HIV) and migration. Participants were a sample of recent regional and international migrants who used an illicit substance or had recent problem drinking. Trypanosoma cruzi infection was classified as testing positive on two different enzyme-linked immunosorbent assays (ELISAs). Interviewer-administered surveys captured sociodemographics, migration history, Chagas disease knowledge, and access to care. We enrolled 389 recent migrants, and the prevalence of Chagas disease was 3.1%. Only 19% of the participants reported having ever heard of the disease and less than 1% had been previously tested. Trypanosoma cruzi -positive participants were more likely to have been born in a rural area or town than a city (92% yes versus 59% no, P = 0.02) and have recently lived in a house with a makeshift roof (33% yes versus 8% no, P < 0.01), walls (42% yes versus 13% no, P < 0.01), or floor (50% yes versus 21% no, P < 0.02), or cinderblock walls (92% yes versus 63% no, P = 0.04). With migration rapidly changing the distribution of Chagas disease, more work needs to be done to create targeted surveillance programs and provide access to affordable treatment among Latin American migrants.

  4. Evolution of the clinical and epidemiological knowledge about Chagas disease 90 years after its discovery

    Directory of Open Access Journals (Sweden)

    Prata Aluízio

    1999-01-01

    Full Text Available Three different periods may be considered in the evolution of knowledge about the clinical and epidemiological aspects of Chagas disease since its discovery: (a early period concerning the studies carried out by Carlos Chagas in Lassance with the collaboration of other investigators of the Manguinhos School. At that time the disease was described and the parasite, transmitters and reservoirs were studied. The coexistence of endemic goiter in the same region generated some confusion about the clinical forms of the disease; (b second period involving uncertainty and the description of isolated cases, which lasted until the 1940 decade. Many acute cases were described during this period and the disease was recognized in many Latin American countries. Particularly important were the studies of the Argentine Mission of Regional Pathology Studies, which culminated with the description of the Romaña sign in the 1930 decade, facilitating the diagnosis of the early phase of the disease. However, the chronic phase, which was the most important, continued to be difficult to recognize; (c period of consolidation of knowledge and recognition of the importance of Chagas disease. Studies conducted by Laranja, Dias and Nóbrega in Bambuí updated the description of Chagas heart disease made by Carlos Chagas and Eurico Villela. From then on, the disease was more easily recognized, especially with the emphasis on the use of a serologic diagnosis; (d period of enlargement of knowledges on the disease. The studies on denervation conducted in Ribeirão Preto by Fritz Köberle starting in the 1950 decade led to a better understanding of the relations between Chagas disease and megaesophagus and other visceral megas detected in endemic areas.

  5. Design and optical analyses of an arrayed microfluidic tunable prism panel for enhancing solar energy collection

    International Nuclear Information System (INIS)

    Narasimhan, Vinayak; Jiang, Dongyue; Park, Sung-Yong

    2016-01-01

    Highlights: • We present an arrayed tunable prism panel enabling wide tracking and high solar concentration. • A microfluidic technology allows a low-cost, lightweight and precise solar tracking system. • Our prism panel enables high solar concentration up to 2032× factor. • Various liquid prism configurations (stacked prism arrays) and optical materials are considered. • Their impacts on solar beam steering, reflection losses and beam concentration are studied. - Abstract: We present the design and optical analyses of an arrayed microfluidic tunable prism panel that enables wide solar tracking and high solar concentration while minimizing energy loss. Each of the liquid prism modules is implemented by a microfluidic (i.e. non-mechanical) technology based on electrowetting for adaptive solar beam steering. Therefore the proposed platform offers a low-cost, lightweight and precise solar tracking system while obviating the need for bulky and heavy mechanical moving parts essentially required for a conventional motor-driven solar tracker. In this paper, various liquid prism configurations in terms of design (single, double, triple and quad-stacked prism arrays) as well as optical materials are considered and their impact on optical performance aspects such as solar beam steering, reflection losses and beam concentration is studied. Our system is able to achieve a wide solar tracking covering the whole-day movement of the Sun and a reflection loss below 4.4% with a Rayleigh’s film for a quad-stacked prism configuration. Furthermore, an arrayed prism panel is proposed to increase the aperture area and thus allows for the collection of large amounts of sunlight. Our simulation study based on the optical design software, ZEMAX, indicates that the prism panel is capable of high solar concentration up to 2032× factor even without conventional solar tracking devices. We also deal with dispersion characteristics of the materials and their corresponding effect on

  6. PERANCANGAN DAN IMPLEMENTASI SISTEM PENGUKURAN KINERJA DENGAN METODE PERFORMANCE PRISM (Studi Kasus pada Hotel X)

    OpenAIRE

    Iwan Vanany; Dian Tanukhidah

    2004-01-01

    This article described a result of research design of performance measurement system in hotel business with Performance Prism Model. As long as, performance measurement system at hotel X not yet representatived organization performance according to comprehensif and integrated. Because of needed redesign performance measurement system with new model. From the objective condition of hotel X, Performance Prism model more representative than others. The result of design described that stakeholder...

  7. Necroscopic study of a Chagas' disease chronic case with normal electrocardiograms

    International Nuclear Information System (INIS)

    Lopes, E.R.; Rocha, A.; Adad, S.J.; Fernandes, E.L.; Chapadeiro, E.

    1988-01-01

    The morphological changes in the postmortem study of a man probably with the indeterminate form of Chagas' disease are described. The heart exhibited lesions of the epicardium, myocardium and endocardium, as well as of the conduction system, primarily small inflammatory foci. There was mild fibrosis of the myocardium, atrioventricular node, and left bundle branch (at its origin). These alterations, although mild, were similar, in quality, to those described in the other chronic forms of Chagas' disease, and suggest active lesions, with a potential for further development. In the esophagus, among other features, a striking reduction of the number of neurons was observed. (author)

  8. Urban outbreak of acute orally acquired Chagas disease in Táchira, Venezuela

    OpenAIRE

    Benítez, Jesús A.; Araujo, Benjamín; Contreras, Krisell; Rivas, Marianela; Ramírez, Pedro; Guerra, Watermo; Calderón, Noél; Terren, Carlo Ascaso; Barrera, Reggie; Rodríguez Morales, Alfonso Javier

    2013-01-01

    Aguda por vía oral adquirió la enfermedad de Chagas (AOACD) se ha convertido en una amenaza importante en algunos países de América del Sur [1,2]. Hasta marzo de 2013, al menos cuatro han reportado brotes de la enfermedad de Chagas aguda adquirida por vía oral, en concreto Brasil [3], Venezuela [4], Colombia [5] y Bolivia [6]. Los brotes también se están produciendo probablemente en Argentina y Ecuador, según algunos informes antiguos [2]. En Venezuela, ha habido por lo menos tres informes ep...

  9. Drug discovery for Chagas disease should consider Trypanosoma cruzi strain diversity

    Directory of Open Access Journals (Sweden)

    Bianca Zingales

    2014-09-01

    Full Text Available This opinion piece presents an approach to standardisation of an important aspect of Chagas disease drug discovery and development: selecting Trypanosoma cruzi strains for in vitro screening. We discuss the rationale for strain selection representing T. cruzi diversity and provide recommendations on the preferred parasite stage for drug discovery, T. cruzi discrete typing units to include in the panel of strains and the number of strains/clones for primary screens and lead compounds. We also consider experimental approaches for in vitro drug assays. The Figure illustrates the current Chagas disease drug-discovery and development landscape.

  10. Histopathologic identification of Trypanosoma cruzi (Chagas' encephalitis in an AIDS patient

    Directory of Open Access Journals (Sweden)

    Dimath Alyemni

    2017-03-01

    Full Text Available Trypanosoma cruzi (Chagas' encephalitis is an uncommon manifestation of T. cruzi infection, typically seen in immunocompromised patients. Encephalitis results from the reactivation of chronic infection predominately in individuals from endemic areas. Increased awareness of this complication is essential especially with increased migration of patients from endemic areas with concomitant HIV infection. Here we report a case of Chagas' encephalitis in an AIDS patient from Mexico in which there was no evidence of acute serologic, CSF, or blood infection by T. cruzi trypomastigotes.

  11. [Chagas's disease and deep ecology: the anti-vectorial fight in question].

    Science.gov (United States)

    Siqueira-Batista, Rodrigo; Gomes, Andréia Patrícia; Rôças, Giselle; Cotta, Rosângela Minardi Mitre; Rubião, Eduardo Cárdenas Nogueira; Pissinatti, Alcides

    2011-02-01

    The inter-relations between man and the environment are among the main themes currently debated by the Brazilian public health. On such horizon, the questions concerning Chagas's disease are found to remain specially in the scope of the directed actions of control to the triatomine, the anti-vectorial fight , though already a century since its first description by Carlos Chagas, a major epidemiological problem in Latin America. Based on these considerations the present article will seek to discuss the main ecological aspects related to the American trypanosomiasis, emphasizing the control of the vectorial transmission in the context of the deep ecology.

  12. Characterizing structures on borehole images and logging data of the Nankai trough accretionary prism: new insights

    Science.gov (United States)

    Jurado, Maria Jose

    2016-04-01

    IODP has extensively used the D/V Chikyu to drill the Kumano portion of the Nankai Trough, including two well sites within the Kumano Basin. IODP Expeditions 338 and 348 drilled deep into the inner accretionary prism south of the Kii Peninsula collecting a suite of LWD data, including natural gamma ray, electrical resistivity logs and borehole images, suitable to characterize structures (fractures and faults) inside the accretionary prism. Structural interpretation and analysis of logging-while-drilling data in the deep inner prism revealed intense deformation of a generally homogenous lithology characterized by bedding that dips steeply (60-90°) to the NW, intersected by faults and fractures. Multiple phases of deformation are characterized. IODP Expedition borehole images and LWD data acquired in the last decade in previous and results of NantroSEIZE IODP Expeditions (314, 319) were also analyzed to investigate the internal geometries and structures of the Nankai Trough accretionary prism. This study focused mainly on the characterization of the different types of structures and their specific position within the accretionary prism structures. New structural constraints and methodologies as well as a new approach to the characterization of study of active structures inside the prism will be presented.

  13. A study on suppressing transmittance fluctuations for air-gapped Glan-type polarizing prisms

    Science.gov (United States)

    Zhang, Chuanfa; Li, Dailin; Zhu, Huafeng; Li, Chuanzhi; Jiao, Zhiyong; Wang, Ning; Xu, Zhaopeng; Wang, Xiumin; Song, Lianke

    2018-05-01

    Light intensity transmittance is a key parameter for the design of polarizing prisms, while sometimes its experimental curves based on spatial incident angle presents periodical fluctuations. Here, we propose a novel method for completely suppressing these fluctuations via setting a glued error angle in the air gap of Glan-Taylor prisms. The proposal consists of: an accurate formula of the intensity transmittance for Glan-Taylor prisms, a numerical simulation and a contrast experiment of Glan-Taylor prisms for analyzing the causes of the fluctuations, and a simple method for accurately measuring the glued error angle. The result indicates that when the setting glued error angle is larger than the critical angle for a certain polarizing prism, the fluctuations can be completely suppressed, and a smooth intensity transmittance curve can be obtained. Besides, the critical angle in the air gap for suppressing the fluctuations is decreased with the increase of beam spot size. This method has the advantage of having less demand for the prism position in optical systems.

  14. Use of yoked prisms in patients with acquired brain injury: a retrospective analysis.

    Science.gov (United States)

    Bansal, Surbhi; Han, Esther; Ciuffreda, Kenneth J

    2014-01-01

    The purpose of this retrospective study was to determine the clinical practices for prescribing yoked prisms, as well as to assess related patient responses, in a sample of visually-symptomatic patients having acquired brain injury (ABI). The clinical records of individuals with acquired brain injury (ABI) that were assessed for yoked prisms were reviewed retrospectively. This query resulted in 60 patient records for analysis between January 2011 and December 2012. The following diagnostic groups were analysed: homonymous hemianopsia (HH)/homonymous quadranopsia, abnormal egocentric localization (AEL) and visual neglect. HH/homonymous quadranopsia (58.3%) was the primary indication to prescribe yoked prisms, followed by visual neglect/unilateral spatial inattention (USI) (40.0%) and AEL (11.7%). The most common favourable patient responses were increased awareness of their blind visual field and improved gait, mobility and balance. The magnitude and direction of prisms prescribed were dependent upon the subjective responses in patients manifesting AEL. In contrast, base direction was dependent upon the direction of visual field loss in patients with HH/homonymous quadranopsia and visual neglect. Two-thirds of the present sample population responded favourably to the yoked prisms. The results of the present study should prove useful to clinicians for the successful prescription of yoked prisms as a treatment modality in patients presenting with the above three diagnoses.

  15. PRISM Software: Processing and Review Interface for Strong‐Motion Data

    Science.gov (United States)

    Jones, Jeanne M.; Kalkan, Erol; Stephens, Christopher D.; Ng, Peter

    2017-01-01

    A continually increasing number of high‐quality digital strong‐motion records from stations of the National Strong Motion Project (NSMP) of the U.S. Geological Survey, as well as data from regional seismic networks within the United States, calls for automated processing of strong‐motion records with human review limited to selected significant or flagged records. The NSMP has developed the Processing and Review Interface for Strong Motion data (PRISM) software to meet this need. In combination with the Advanced National Seismic System Quake Monitoring System (AQMS), PRISM automates the processing of strong‐motion records. When used without AQMS, PRISM provides batch‐processing capabilities. The PRISM software is platform independent (coded in Java), open source, and does not depend on any closed‐source or proprietary software. The software consists of two major components: a record processing engine composed of modules for each processing step, and a review tool, which is a graphical user interface for manual review, edit, and processing. To facilitate use by non‐NSMP earthquake engineers and scientists, PRISM (both its processing engine and review tool) is easy to install and run as a stand‐alone system on common operating systems such as Linux, OS X, and Windows. PRISM was designed to be flexible and extensible to accommodate implementation of new processing techniques. All the computing features have been thoroughly tested.

  16. Asymmetrical effects of adaptation to left- and right-shifting prisms depends on pre-existing attentional biases.

    Science.gov (United States)

    Goedert, Kelly M; Leblanc, Andrew; Tsai, Sen-Wei; Barrett, Anna M

    2010-09-01

    Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal individuals rely on a dissociation between the postadaptation performance of individuals trained with left- versus right-shifting prisms (e.g., Colent, Pisella, & Rossetti, 2000). A potential problem with this evidence is that normal young adults have an a priori leftward bias (e.g., Jewell & McCourt, 2000). In Experiment 1, we compared the line bisection performance of young adults to that of aged adults, who as a group may lack a leftward bias in line bisection. Participants trained with both left- and right-shifting prisms. Consistent with our hypothesis, while young adults demonstrated aftereffects for left, but not right prisms, aged adults demonstrated reliable aftereffects for both prisms. In Experiment 2, we recruited a larger sample of young adults, some of whom were right-biased at baseline. We observed an interaction between baseline bias and prism-shift, consistent with the results of Experiment 1: Left-biased individuals showed a reduced aftereffect when training with right-shifting prisms and right-biased individuals showed a reduced aftereffect when training with left-shifting prisms. These results suggest that previous failures to find generalizable aftereffects with right-shifting prisms may be driven by participants' baseline biases rather than specific effects of the prism itself.

  17. Comprehensive analysis of three TYK2 gene variants in the susceptibility to Chagas disease infection and cardiomyopathy

    Science.gov (United States)

    Carmona, F. David; Dolade, Nuria; Vargas, Sofia; Echeverría, Luis Eduardo; González, Clara Isabel; Martin, Javier

    2018-01-01

    Tyrosine kinase 2 (TYK2) is a member of the Janus kinases family implicated in the signal transduction of type I interferons and several interleukins. It has been described that genetic mutations within TYK2 lead to multiple deleterious effects in the immune response. In this work, we have analyzed three functional independent variants from the frequency spectrum on the TYK2 gene (common and low-frequency variants) suggested to reduce the function of the gene in mediating cytokine signaling and the susceptibility to infections by Trypanosoma cruzi and/or the development of Chagas cardiomyopathy in the Colombian population. A total of 1,323 individuals from a Colombian endemic region for Chagas disease were enrolled in the study. They were classified as seronegative (n = 445), seropositive asymptomatic (n = 336), and chronic Chagas Cardiomyopathy subjects (n = 542). DNA samples were genotyped using TaqMan probes. Our results showed no statistically significant differences between the allelic frequencies of the three analyzed variants when seropositive and seronegative individuals were compared, therefore these variants were not associated with susceptibility to Chagas disease. Moreover, when Chagas cardiomyopathy patients were compared to asymptomatic patients, no significant associations were found. Previous reports highlighted the association of this gene in immune-related disorders under an autoimmunity context, but not predisposing patients to infectious diseases, which is consistent with our findings. Therefore, according to our results, TYK2 gene variants do not seem to play an important role in Chagas disease susceptibility and/or chronic Chagas cardiomyopathy. PMID:29304122

  18. Técnica do xenodiagnostico na molestia de Chagas

    Directory of Open Access Journals (Sweden)

    Emmanuel Dias

    1940-01-01

    Full Text Available O xenodiagnostico é um processo muito valioso para o diagnostico etiologico da moléstia de Chagas. Consiste em alimentar-se barbeiros normais em supótos portadores da infecção e determinar-se, depois, si eles adquirem ou não o parasitismo. Em cada região deve ser empregada, de preferência, o transmissor local mais importante. Três a seis ninfas famintas são geralmente empregadas em cada prova, devendo ficar em contacto com o doador até encherem-se completamente (15-30 minutos. Si o exame de fezes – espontaneamente eliminadas ou obtidas por punção anal – não revelar a presença de flagelados, os insetos devem ser dissecados 40 a 60 dias depois da sucção, para exame do conteúdo duodenal.Xenodiagnosis is a very valuable method for the etiological diagnosis of Chagas’s disease. It consists in allowing the clean insect transmitter to feed upon the suspected carrier, and in ascertaining whether the bugs become infected. The principal local vector is the most suitable species to be used in a given region. Three to six hungry nymphs are usually employed in each test and must feed until repletion (15-30 minutes. It flagellates are not detected in the faeces or in the rectal contents, obtained by anal puncture, insects are dissected 40-60 days after the and the duodenal contents is examined.

  19. Environmental Changes Can Produce Shifts in Chagas Disease Infection Risk

    Directory of Open Access Journals (Sweden)

    Juan M. Cordovez

    2014-01-01

    Full Text Available An epidemiological network contains all the organisms involved (types in the transmission of a parasite. The nodes of the network represent reservoirs, hosts, and vectors, while the links between the nodes represent the strength and direction of parasite movement. Networks that contain humans are of special interest because they are of concern to public health authorities. Under these circumstances, it is possible, in principle, to identify cycles (closed paths in the network that include humans and select the ones that carry the maximum probability of human infection. The basic reproduction number R 0 in such a network gives the average number of new infections of any type after the introduction of one individual infected by any type. To obtain R 0 for complex networks, one can use the next-generation matrix (NGM approach. Every entry in NGM will average the contribution of each link that connects two types. To tease the contribution of every cycle apart, we define the virulence as the geometric mean of the NGM entries corresponding to the links therein. This approach allows for the quantification of specific cycles of interest while it also makes the computation of the sensitivity and elasticity of the parameters easier. In this work, we compute the virulence for the transmission dynamics of Chagas disease for a typical rural area in Colombia incorporating the effect of environmental changes on the vector population size. We concluded that the highest contribution to human infection comes from humans themselves, which is a surprising and interesting result. In addition, sensitivity analysis revealed that increasing vector population size increases the risk of human infection.

  20. Molecular epidemiology of human oral Chagas disease outbreaks in Colombia.

    Directory of Open Access Journals (Sweden)

    Juan David Ramírez

    Full Text Available BACKGROUND: Trypanosoma cruzi, the causative agent of Chagas disease, displays significant genetic variability revealed by six Discrete Typing Units (TcI-TcVI. In this pathology, oral transmission represents an emerging epidemiological scenario where different outbreaks associated to food/beverages consumption have been reported in Argentina, Bolivia, Brazil, Ecuador and Venezuela. In Colombia, six human oral outbreaks have been reported corroborating the importance of this transmission route. Molecular epidemiology of oral outbreaks is barely known observing the incrimination of TcI, TcII, TcIV and TcV genotypes. METHODOLOGY AND PRINCIPAL FINDINGS: High-throughput molecular characterization was conducted performing MLMT (Multilocus Microsatellite Typing and mtMLST (mitochondrial Multilocus Sequence Typing strategies on 50 clones from ten isolates. Results allowed observing the occurrence of TcI, TcIV and mixed infection of distinct TcI genotypes. Thus, a majority of specific mitochondrial haplotypes and allelic multilocus genotypes associated to the sylvatic cycle of transmission were detected in the dataset with the foreseen presence of mitochondrial haplotypes and allelic multilocus genotypes associated to the domestic cycle of transmission. CONCLUSIONS: These findings suggest the incrimination of sylvatic genotypes in the oral outbreaks occurred in Colombia. We observed patterns of super-infection and/or co-infection with a tailored association with the severe forms of myocarditis in the acute phase of the disease. The transmission dynamics of this infection route based on molecular epidemiology evidence was unraveled and the clinical and biological implications are discussed.

  1. Barriers to treatment access for Chagas disease in Mexico.

    Science.gov (United States)

    Manne, Jennifer M; Snively, Callae S; Ramsey, Janine M; Salgado, Marco Ocampo; Bärnighausen, Till; Reich, Michael R

    2013-01-01

    According to World Health Organization (WHO) prevalence estimates, 1.1 million people in Mexico are infected with Trypanosoma cruzi, the etiologic agent of Chagas disease (CD). However, limited information is available about access to antitrypanosomal treatment. This study assesses the extent of access in Mexico, analyzes the barriers to access, and suggests strategies to overcome them. Semi-structured in-depth interviews were conducted with 18 key informants and policymakers at the national level in Mexico. Data on CD cases, relevant policy documents and interview data were analyzed using the Flagship Framework for Pharmaceutical Policy Reform policy interventions: regulation, financing, payment, organization, and persuasion. Data showed that 3,013 cases were registered nationally from 2007-2011, representing 0.41% of total expected cases based on Mexico's national prevalence estimate. In four of five years, new registered cases were below national targets by 11-36%. Of 1,329 cases registered nationally in 2010-2011, 834 received treatment, 120 were pending treatment as of January 2012, and the treatment status of 375 was unknown. The analysis revealed that the national program mainly coordinated donation of nifurtimox and that important obstacles to access include the exclusion of antitrypanosomal medicines from the national formulary (regulation), historical exclusion of CD from the social insurance package (organization), absence of national clinical guidelines (organization), and limited provider awareness (persuasion). Efforts to treat CD in Mexico indicate an increased commitment to addressing this disease. Access to treatment could be advanced by improving the importation process for antitrypanosomal medicines and adding them to the national formulary, increasing education for healthcare providers, and strengthening clinical guidelines. These recommendations have important implications for other countries in the region with similar problems in access to

  2. Insecticide resistance in vector Chagas disease: evolution, mechanisms and management.

    Science.gov (United States)

    Mougabure-Cueto, Gastón; Picollo, María Inés

    2015-09-01

    Chagas disease is a chronic parasitic infection restricted to America. The disease is caused by the protozoa Trypanosoma cruzi, which is transmitted to human through the feces of infected triatomine insects. Because no treatment is available for the chronic forms of the disease, vector chemical control represents the best way to reduce the incidence of the disease. Chemical control has been based principally on spraying dwellings with insecticide formulations and led to the reduction of triatomine distribution and consequent interruption of disease transmission in several areas from endemic region. However, in the last decade it has been repeatedly reported the presence triatomnes, mainly Triatoma infestans, after spraying with pyrethroid insecticides, which was associated to evolution to insecticide resistance. In this paper the evolution of insecticide resistance in triatomines is reviewed. The insecticide resistance was detected in 1970s in Rhodnius prolixus and 1990s in R. prolixus and T. infestans, but not until the 2000s resistance to pyrthroids in T. infestans associated to control failures was described in Argentina and Bolivia. The main resistance mechanisms (i.e. enhanced metabolism, altered site of action and reduced penetration) were described in the T. infestans resistant to pyrethrods. Different resistant profiles were demonstrated suggesting independent origin of the different resistant foci of Argentina and Bolivia. The deltamethrin resistance in T. infestans was showed to be controlled by semi-dominant, autosomally inherited factors. Reproductive and developmental costs were also demonstrated for the resistant T. infestans. A discussion about resistance and tolerance concepts and the persistence of T. infestans in Gran Chaco region are presented. In addition, theoretical concepts related to toxicological, evolutionary and ecological aspects of insecticide resistance are discussed in order to understand the particular scenario of pyrethroid

  3. Effect of prism adaptation on left dichotic listening deficit in neglect patients: glasses to hear better?

    Science.gov (United States)

    Jacquin-Courtois, S; Rode, G; Pavani, F; O'Shea, J; Giard, M H; Boisson, D; Rossetti, Y

    2010-03-01

    Unilateral neglect is a disabling syndrome frequently observed following right hemisphere brain damage. Symptoms range from visuo-motor impairments through to deficient visuo-spatial imagery, but impairment can also affect the auditory modality. A short period of adaptation to a rightward prismatic shift of the visual field is known to improve a wide range of hemispatial neglect symptoms, including visuo-manual tasks, mental imagery, postural imbalance, visuo-verbal measures and number bisection. The aim of the present study was to assess whether the beneficial effects of prism adaptation may generalize to auditory manifestations of neglect. Auditory extinction, whose clinical manifestations are independent of the sensory modalities engaged in visuo-manual adaptation, was examined in neglect patients before and after prism adaptation. Two separate groups of neglect patients (all of whom exhibited left auditory extinction) underwent prism adaptation: one group (n = 6) received a classical prism treatment ('Prism' group), the other group (n = 6) was submitted to the same procedure, but wore neutral glasses creating no optical shift (placebo 'Control' group). Auditory extinction was assessed by means of a dichotic listening task performed three times: prior to prism exposure (pre-test), upon prism removal (0 h post-test) and 2 h later (2 h post-test). The total number of correct responses, the lateralization index (detection asymmetry between the two ears) and the number of left-right fusion errors were analysed. Our results demonstrate that prism adaptation can improve left auditory extinction, thus revealing transfer of benefit to a sensory modality that is orthogonal to the visual, proprioceptive and motor modalities directly implicated in the visuo-motor adaptive process. The observed benefit was specific to the detection asymmetry between the two ears and did not affect the total number of responses. This indicates a specific effect of prism adaptation on

  4. Further genetic characterization of the two Trypanosoma cruzi Berenice strains (Be-62 and Be-78) isolated from the first human case of Chagas disease (Chagas, 1909).

    Science.gov (United States)

    Cruz, R E; Macedo, A M; Barnabé, C; Freitas, J M; Chiari, E; Veloso, V M; Carneiro, C M; Bahia, M T; Tafuri, Washington L; Lana, M

    2006-03-01

    We describe here an extension of a previous genetic characterization of Trypanosoma cruzi strains (Be-62 and Be-78) isolated from the patient Berenice, the first human case of Chagas disease [Chagas, C., 1909. Nova Tripanomíase humana. Estudos sobre morfologia e o ciclo evolutivo do Schizotrypanum cruzi, n. gen., n. sp., agente etiolójico da nova entidade morbida do homem. Mem. Inst. Oswaldo Cruz 1, 159-218]. We wanted to verify the composition of T. cruzi populations originated from these two isolates. In the present work, 22 enzymatic loci (MLEE), nine RAPD primers and 7 microsatellite loci were analyzed. Clones from both strains were also characterized to verify whether these strains are mono or polyclonal. Be-62 and Be-78 strains were different in 3 out of 22 enzymatic systems, in 3 out of 9 RAPD primers tested and in all microsatellite loci investigated. However, our data suggests that both strains are phylogenetically closely related, belonging to genetic group 32 from Tibayrenc and Ayala [Tibayrenc, M., Ayala, F.J., 1988. Isoenzime variability in Trypanosoma cruzi, the agent of Chagas' disease: genetical, taxonomical, and epidemiological significance. Evolution 42, 277-292], equivalent to zymodeme 2 and T. cruzi II major lineage which, in Brazil, comprises parasites from the domestic cycle of the disease. Microsatellite analyses showed differences between the parental strains but suggested that both populations are monoclonal since each strain and their respective clones showed the same amplification products.

  5. Post-mortem diagnosis of chronic Chagas's disease comparative evaluation of three serological tests on pericardial fluid.

    Science.gov (United States)

    Lopes, E R; Chapadeiro, E; Batista, S M; Cunha, J G; Rocha, A; Miziara, L; Ribeiro, J U; Patto, R J

    1978-01-01

    In an attempt to improve the post-mortem diagnosis of Chagas's disease the authors performed haemagglutination tests (HAT), fluorescent Trypanosoma cruzi antibody tests (FAT), and complement fixation tests (CFT) on the pericardial fluid obtained at autopsy of 50 individuals with Chagas's heart disease, and 93 patients in whom this disease was not thought to be present. The results demonstrate that all three tests are efficient for the post-mortem diagnosis of Chagas's disease but suggest that their combined use would detect more cases than would one isolated reaction only.

  6. Mode of death on Chagas heart disease: comparison with other etiologies. a subanalysis of the REMADHE prospective trial.

    Directory of Open Access Journals (Sweden)

    Silvia M Ayub-Ferreira

    Full Text Available Sudden death has been considered the main cause of death in patients with Chagas heart disease. Nevertheless, this information comes from a period before the introduction of drugs that changed the natural history of heart failure. We sought to study the mode of death of patients with heart failure caused by Chagas heart disease, comparing with non-Chagas cardiomyopathy.We examined the REMADHE trial and grouped patients according to etiology (Chagas vs non-Chagas and mode of death. The primary end-point was all-cause, heart failure and sudden death mortality; 342 patients were analyzed and 185 (54.1% died. Death occurred in 56.4% Chagas patients and 53.7% non-Chagas patients. The cumulative incidence of all-cause mortality and heart failure mortality was significantly higher in Chagas patients compared to non-Chagas. There was no difference in the cumulative incidence of sudden death mortality between the two groups. In the Cox regression model, Chagas etiology (HR 2.76; CI 1.34-5.69; p = 0.006, LVEDD (left ventricular end diastolic diameter (HR 1.07; CI 1.04-1.10; p<0.001, creatinine clearance (HR 0.98; CI 0.97-0.99; p = 0.006 and use of amiodarone (HR 3.05; CI 1.47-6.34; p = 0.003 were independently associated with heart failure mortality. LVEDD (HR 1.04; CI 1.01-1.07; p = 0.005 and use of beta-blocker (HR 0.52; CI 0.34-0.94; p = 0.014 were independently associated with sudden death mortality.In severe Chagas heart disease, progressive heart failure is the most important mode of death. These data challenge the current understanding of Chagas heart disease and may have implications in the selection of treatment choices, considering the mode of death.ClinicalTrials.gov NCT00505050 (REMADHE.

  7. Geochemistry of mud volcano fluids in the Taiwan accretionary prism

    International Nuclear Information System (INIS)

    You Chenfeng; Gieskes, Joris M.; Lee, Typhoon; Yui Tzenfu; Chen Hsinwen

    2004-01-01

    Taiwan is located at the collision boundary between the Philippine Sea Plate and the Asian Continental Plate and is one of the most active orogenic belts in the world. Fluids sampled from 9 sub-aerial mud volcanoes distributed along two major geological structures in southwestern Taiwan, the Chishan fault and the Gutingkeng anticline, were analyzed to evaluate possible sources of water and the degree of fluid-sediment interaction at depth in an accretionary prism. Overall, the Taiwanese mud volcano fluids are characterized by high Cl contents, up to 347 mM, suggesting a marine origin from actively de-watering sedimentary pore waters along major structures on land. The fluids obtained from the Gutingkeng anticline, as well as from the Coastal Plain area, show high Cl, Na, K, Ca, Mg and NH 4 , but low SO 4 and B concentrations. In contrast, the Chishan fault fluids are much less saline (1/4 seawater value), but show much heavier O isotope compositions (δ 18 O=5.1-6.5 %o). A simplified scenario of mixing between sedimentary pore fluids and waters affected by clay dehydration released at depth can explain several crucial observations including heavy O isotopes, radiogenic Sr contents ( 87 Sr/ 86 Sr=0.71136-0.71283), and relatively low salinities in the Chishan fluids. Gases isolated from the mud volcanoes are predominantly CH 4 and CO 2 , where the CH 4 -C isotopic compositions show a thermogenic component of δ 13 C=-38 %o. These results demonstrate that active mud volcano de-watering in Taiwan is a direct product of intense sediment accretion and plate collision in the region

  8. Extended-Range Ultrarefractive 1D Photonic Crystal Prisms

    Science.gov (United States)

    Ting, David Z.

    2007-01-01

    by use of conventional prisms and diffraction gratings and is highly nonlinear.

  9. Experimental Chagas disease-induced perturbations of the fecal microbiome and metabolome.

    Science.gov (United States)

    McCall, Laura-Isobel; Tripathi, Anupriya; Vargas, Fernando; Knight, Rob; Dorrestein, Pieter C; Siqueira-Neto, Jair L

    2018-03-01

    Trypanosoma cruzi parasites are the causative agents of Chagas disease. These parasites infect cardiac and gastrointestinal tissues, leading to local inflammation and tissue damage. Digestive Chagas disease is associated with perturbations in food absorption, intestinal traffic and defecation. However, the impact of T. cruzi infection on the gut microbiota and metabolome have yet to be characterized. In this study, we applied mass spectrometry-based metabolomics and 16S rRNA sequencing to profile infection-associated alterations in fecal bacterial composition and fecal metabolome through the acute-stage and into the chronic stage of infection, in a murine model of Chagas disease. We observed joint microbial and chemical perturbations associated with T. cruzi infection. These included alterations in conjugated linoleic acid (CLA) derivatives and in specific members of families Ruminococcaceae and Lachnospiraceae, as well as alterations in secondary bile acids and members of order Clostridiales. These results highlight the importance of multi-'omics' and poly-microbial studies in understanding parasitic diseases in general, and Chagas disease in particular.

  10. Accelerating the development of a therapeutic vaccine for human Chagas disease: rationale and prospects.

    Science.gov (United States)

    Dumonteil, Eric; Bottazzi, Maria Elena; Zhan, Bin; Heffernan, Michael J; Jones, Kathryn; Valenzuela, Jesus G; Kamhawi, Shaden; Ortega, Jaime; de Leon Rosales, Samuel Ponce; Lee, Bruce Y; Bacon, Kristina M; Fleischer, Bernhard; Slingsby, B T; Cravioto, Miguel Betancourt; Tapia-Conyer, Roberto; Hotez, Peter J

    2012-09-01

    Chagas disease is a leading cause of heart disease affecting approximately 10 million people in Latin America and elsewhere worldwide. The two major drugs available for the treatment of Chagas disease have limited efficacy in Trypanosoma cruzi-infected adults with indeterminate (patients who have seroconverted but do not yet show signs or symptoms) and determinate (patients who have both seroconverted and have clinical disease) status; they require prolonged treatment courses and are poorly tolerated and expensive. As an alternative to chemotherapy, an injectable therapeutic Chagas disease vaccine is under development to prevent or delay Chagasic cardiomyopathy in patients with indeterminate or determinate status. The bivalent vaccine will be comprised of two recombinant T. cruzi antigens, Tc24 and TSA-1, formulated on alum together with the Toll-like receptor 4 agonist, E6020. Proof-of-concept for the efficacy of these antigens was obtained in preclinical testing at the Autonomous University of Yucatan. Here the authors discuss the potential for a therapeutic Chagas vaccine as well as the progress made towards such a vaccine, and the authors articulate a roadmap for the development of the vaccine as planned by the nonprofit Sabin Vaccine Institute Product Development Partnership and Texas Children's Hospital Center for Vaccine Development in collaboration with an international consortium of academic and industrial partners in Mexico, Germany, Japan, and the USA.

  11. Metallothionein-1 and nitric oxide expression are inversely correlated in a murine model of Chagas disease

    Directory of Open Access Journals (Sweden)

    Martha Elba Gonzalez-Mejia

    2014-04-01

    Full Text Available Chagas disease, caused by Trypanosoma cruzi, represents an endemic among Latin America countries. The participation of free radicals, especially nitric oxide (NO, has been demonstrated in the pathophysiology of seropositive individuals with T. cruzi. In Chagas disease, increased NO contributes to the development of cardiomyopathy and megacolon. Metallothioneins (MTs are efficient free radicals scavengers of NO in vitro and in vivo. Here, we developed a murine model of the chronic phase of Chagas disease using endemic T. cruzi RyCH1 in BALB/c mice, which were divided into four groups: infected non-treated (Inf, infected N-monomethyl-L-arginine treated (Inf L-NAME, non-infected L-NAME treated and non-infected vehicle-treated. We determined blood parasitaemia and NO levels, the extent of parasite nests in tissues and liver MT-I expression levels. It was observed that NO levels were increasing in Inf mice in a time-dependent manner. Inf L-NAME mice had fewer T. cruzi nests in cardiac and skeletal muscle with decreased blood NO levels at day 135 post infection. This affect was negatively correlated with an increase of MT-I expression (r = -0.8462, p < 0.0001. In conclusion, we determined that in Chagas disease, an unknown inhibitory mechanism reduces MT-I expression, allowing augmented NO levels.

  12. ADENOSINE DEAMINASE ACTIVITY AND SERUM C-REACTIVE PROTEIN AS PROGNOSTIC MARKERS OF CHAGAS DISEASE SEVERITY

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    Iván Darío BRAVO-TOBAR

    2015-10-01

    Full Text Available SUMMARY Chagas disease is a public health problem worldwide. The availability of diagnostic tools to predict the development of chronic Chagas cardiomyopathy is crucial to reduce morbidity and mortality. Here we analyze the prognostic value of adenosine deaminase serum activity (ADA and C-reactive protein serum levels (CRP in chagasic individuals. One hundred and ten individuals, 28 healthy and 82 chagasic patients were divided according to disease severity in phase I (n = 35, II (n = 29, and III (n = 18. A complete medical history, 12-lead electrocardiogram, chest X-ray, and M-mode echocardiogram were performed on each individual. Diagnosis of Chagas disease was confirmed by ELISA and MABA using recombinant antigens; ADA was determined spectrophotometrically and CRP by ELISA. The results have shown that CRP and ADA increased linearly in relation to disease phase, CRP being significantly higher in phase III and ADA at all phases. Also, CRP and ADA were positively correlated with echocardiographic parameters of cardiac remodeling and with electrocardiographic abnormalities, and negatively with ejection fraction. CRP and ADA were higher in patients with cardiothoracic index ≥ 50%, while ADA was higher in patients with ventricular repolarization disturbances. Finally, CRP was positively correlated with ADA. In conclusion, ADA and CRP are prognostic markers of cardiac dysfunction and remodeling in Chagas disease.

  13. Antagonistic Effect of Atorvastatin on High Fat Diet Induced Survival during Acute Chagas Disease

    Science.gov (United States)

    Zhao, Dazhi; Lizardo, Kezia; Cui, Min Hui; Ambadipudi, Kamalakar; Lora, Jose; Jelicks, Linda A; Nagajyothi, Jyothi F

    2016-01-01

    Chagasic cardiomyopathy, which is seen in Chagas Disease, is the most severe and life-threatening manifestation of infection by the kinetoplastid Trypanosoma cruzi. Adipose tissue and diet play a major role in maintaining lipid homeostasis and regulating cardiac pathogenesis during the development of Chagas cardiomyopathy. We have previously reported that T. cruzi has a high affinity for lipoproteins and that the invasion rate of this parasite increases in the presence of cholesterol, suggesting that drugs that inhibit cholesterol synthesis, such as statins, could affect infection and the development of Chagasic cardiomyopathy. The dual epidemic of diabetes and obesity in Latin America, the endemic regions for Chagas Disease, has led to many patients in the endemic region of infection having hyperlipidemia that is being treated with statins such as atorvastatin. The current study was performed to examine using mice fed on either regular or high fat diet the effect of atorvastatin on T. cruzi infection-induced myocarditis and to evaluate the effect of this treatment during infection on adipose tissue physiology and cardiac pathology. Atorvastatin was found to regulate lipolysis and cardiac lipidopathy during acute T. cruzi infection in mice and to enhance tissue parasite load, cardiac LDL levels, inflammation, and mortality in during acute infection. Overall, these data suggest that statins, such as atorvastatin, have deleterious effects during acute Chagas disease. PMID:27416748

  14. A Deep Insight Into the Sialotranscriptome of the Chagas Disease Vector, Panstrongylus megistus (Hemiptera: Heteroptera)

    Czech Academy of Sciences Publication Activity Database

    Ribeiro, J.M.C.; Schwarz, Alexandra; Francischetti, I.M.B.

    2015-01-01

    Roč. 52, č. 3 (2015), s. 351-358 ISSN 0022-2585 R&D Projects: GA MŠk LH12002; GA ČR GPP302/11/P798 Institutional support: RVO:60077344 Keywords : Chagas disease * vector biology * salivary gland * transcriptome * medical entomology Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.712, year: 2015

  15. Behavioural alterations are independent of sickness behaviour in chronic experimental Chagas disease.

    Science.gov (United States)

    Vilar-Pereira, Glaucia; Ruivo, Leonardo Alexandre de Souza; Lannes-Vieira, Joseli

    2015-12-01

    The existence of the nervous form of Chagas disease is a matter of discussion since Carlos Chagas described neurological disorders, learning and behavioural alterations in Trypanosoma cruzi-infected individuals. In most patients, the clinical manifestations of the acute phase, including neurological abnormalities, resolve spontaneously without apparent consequence in the chronic phase of infection. However, chronic Chagas disease patients have behavioural changes such as psychomotor alterations, attention and memory deficits, and depression. In the present study, we tested whether or not behavioural alterations are reproducible in experimental models. We show that C57BL/6 mice chronically infected with the Colombian strain of T. cruzi (150 days post-infection) exhibit behavioural changes as (i) depression in the tail suspension and forced swim tests, (ii) anxiety analysed by elevated plus maze and open field test sand and (iii) motor coordination in the rotarod test. These alterations are neither associated with neuromuscular disorders assessed by the grip strength test nor with sickness behaviour analysed by temperature variation sand weight loss. Therefore, chronically T. cruzi-infected mice replicate behavioural alterations (depression and anxiety) detected in Chagas disease patients opening an opportunity to study the interconnection and the physiopathology of these two biological processes in an infectious scenario.

  16. Update on oral Chagas disease outbreaks in Venezuela: epidemiological, clinical and diagnostic approaches

    Science.gov (United States)

    de Noya, Belkisyolé Alarcón; Díaz-Bello, Zoraida; Colmenares, Cecilia; Ruiz-Guevara, Raiza; Mauriello, Luciano; Muñoz-Calderón, Arturo; Noya, Oscar

    2015-01-01

    Orally transmitted Chagas disease has become a matter of concern due to outbreaks reported in four Latin American countries. Although several mechanisms for orally transmitted Chagas disease transmission have been proposed, food and beverages contaminated with whole infected triatomines or their faeces, which contain metacyclic trypomastigotes of Trypanosoma cruzi, seems to be the primary vehicle. In 2007, the first recognised outbreak of orally transmitted Chagas disease occurred in Venezuela and largest recorded outbreak at that time. Since then, 10 outbreaks (four in Caracas) with 249 cases (73.5% children) and 4% mortality have occurred. The absence of contact with the vector and of traditional cutaneous and Romana’s signs, together with a florid spectrum of clinical manifestations during the acute phase, confuse the diagnosis of orally transmitted Chagas disease with other infectious diseases. The simultaneous detection of IgG and IgM by ELISA and the search for parasites in all individuals at risk have been valuable diagnostic tools for detecting acute cases. Follow-up studies regarding the microepidemics primarily affecting children has resulted in 70% infection persistence six years after anti-parasitic treatment. Panstrongylus geniculatus has been the incriminating vector in most cases. As a food-borne disease, this entity requires epidemiological, clinical, diagnostic and therapeutic approaches that differ from those approaches used for traditional direct or cutaneous vector transmission. PMID:25946155

  17. Is endothelial microvascular function equally impaired among patients with chronic Chagas and ischemic cardiomyopathy?

    Science.gov (United States)

    Borges, Juliana Pereira; Mendes, Fernanda de Souza Nogueira Sardinha; Lopes, Gabriella de Oliveira; Sousa, Andréa Silvestre de; Mediano, Mauro Felippe Felix; Tibiriçá, Eduardo

    2018-08-15

    Chronic Chagas cardiomyopathy (CCC) and cardiomyopathies due to other etiologies involve differences in pathophysiological pathways that are still unclear. Systemic microvascular abnormalities are associated with the pathogenesis of ischemic heart disease. However, systemic microvascular endothelial function in CCC remains to be elucidated. Thus, we compared the microvascular endothelial function of patients presenting with CCC to those with ischemic cardiomyopathy disease. Microvascular reactivity was assessed in 21 patients with cardiomyopathy secondary to Chagas disease, 21 patients with cardiomyopathy secondary to ischemic disease and 21 healthy controls. Microvascular blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with iontophoresis of acetylcholine (ACh). Peak increase in forearm blood flow with ACh iontophoresis in relation to baseline was greater in healthy controls than in patients with heart disease (controls: 162.7 ± 58.4% vs. ischemic heart disease: 74.1 ± 48.3% and Chagas: 85.1 ± 68.1%; p < 0.0001). Patients with Chagas and ischemic cardiomyopathy presented similar ACh-induced changes from baseline in skin blood flow (p = 0.55). Endothelial microvascular function was equally impaired among patients with CCC and ischemic cardiomyopathy. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Integrated control of Chagas disease for its elimination as public health problem--a review.

    Science.gov (United States)

    Sosa-Estani, Sergio; Segura, Elsa Leonor

    2015-05-01

    Chagas disease or American trypanosomiasis is, together with geohelminths, the neglected disease that causes more loss of years of healthy life due to disability in Latin America. Chagas disease, as determined by the factors and determinants, shows that different contexts require different actions, preventing new cases or reducing the burden of disease. Control strategies must combine two general courses of action including prevention of transmission to prevent the occurrence of new cases (these measures are cost effective), as well as opportune diagnosis and treatment of infected individuals in order to prevent the clinical evolution of the disease and to allow them to recuperate their health. All actions should be implemented as fully as possible and with an integrated way, to maximise the impact. Chagas disease cannot be eradicated due because of the demonstrated existence of infected wild triatomines in permanent contact with domestic cycles and it contributes to the occurrence of at least few new cases. However, it is possible to interrupt the transmission of Trypanosoma cruzi in a large territory and to eliminate Chagas disease as a public health problem with a dramatic reduction of burden of the disease.

  19. Lutte contre la maladie de Chagas en Amérique centrale | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Guatemala,. En Amérique centrale, les insectes qui transmettent la maladie de Chagas sont nombreux. Les équipes de chercheurs mettent la démarche écosanté à l'épreuve dans 15 emplacements différents se trouvant dans les ...

  20. Towards Chagas disease elimination: Neonatal screening for congenital transmission in rural communities.

    Science.gov (United States)

    Pennington, Pamela Marie; Juárez, José Guillermo; Arrivillaga, Margarita Rivera; De Urioste-Stone, Sandra María; Doktor, Katherine; Bryan, Joe P; Escobar, Clara Yaseli; Cordón-Rosales, Celia

    2017-09-01

    Chagas disease is a neglected tropical disease that continues to affect populations living in extreme poverty in Latin America. After successful vector control programs, congenital transmission remains as a challenge to disease elimination. We used the PRECEDE-PROCEED planning model to develop strategies for neonatal screening of congenital Chagas disease in rural communities of Guatemala. These communities have persistent high triatomine infestations and low access to healthcare. We used mixed methods with multiple stakeholders to identify and address maternal-infant health behaviors through semi-structured interviews, participatory group meetings, archival reviews and a cross-sectional survey in high risk communities. From December 2015 to April 2016, we jointly developed a strategy to illustratively advertise newborn screening at the Health Center. The strategy included socioculturally appropriate promotional and educational material, in collaboration with midwives, nurses and nongovernmental organizations. By March 2016, eight of 228 (3.9%) pregnant women had been diagnosed with T. cruzi at the Health Center. Up to this date, no neonatal screening had been performed. By August 2016, seven of eight newborns born to Chagas seropositive women had been parasitologically screened at the Health Center, according to international standards. Thus, we implemented a successful community-based neonatal screening strategy to promote congenital Chagas disease healthcare in a rural setting. The success of the health promotion strategies developed will depend on local access to maternal-infant services, integration with detection of other congenital diseases and reliance on community participation in problem and solution definition.

  1. Towards Chagas disease elimination: Neonatal screening for congenital transmission in rural communities.

    Directory of Open Access Journals (Sweden)

    Pamela Marie Pennington

    2017-09-01

    Full Text Available Chagas disease is a neglected tropical disease that continues to affect populations living in extreme poverty in Latin America. After successful vector control programs, congenital transmission remains as a challenge to disease elimination. We used the PRECEDE-PROCEED planning model to develop strategies for neonatal screening of congenital Chagas disease in rural communities of Guatemala. These communities have persistent high triatomine infestations and low access to healthcare. We used mixed methods with multiple stakeholders to identify and address maternal-infant health behaviors through semi-structured interviews, participatory group meetings, archival reviews and a cross-sectional survey in high risk communities. From December 2015 to April 2016, we jointly developed a strategy to illustratively advertise newborn screening at the Health Center. The strategy included socioculturally appropriate promotional and educational material, in collaboration with midwives, nurses and nongovernmental organizations. By March 2016, eight of 228 (3.9% pregnant women had been diagnosed with T. cruzi at the Health Center. Up to this date, no neonatal screening had been performed. By August 2016, seven of eight newborns born to Chagas seropositive women had been parasitologically screened at the Health Center, according to international standards. Thus, we implemented a successful community-based neonatal screening strategy to promote congenital Chagas disease healthcare in a rural setting. The success of the health promotion strategies developed will depend on local access to maternal-infant services, integration with detection of other congenital diseases and reliance on community participation in problem and solution definition.

  2. Chronic phase of Chagas disease: why should it be treated? A comprehensive review

    Directory of Open Access Journals (Sweden)

    José Rodrigues Coura

    2011-09-01

    Full Text Available The pathogenesis and evolutive pattern of Chagas disease suggests that the chronic phase should be more widely treated in order to (i eliminate Trypanosoma cruzi and prevent new inflammatory foci and the extension of tissue lesions, (ii promote tissue regeneration to prevent fibrosis, (iii reverse existing fibrosis, (iv prevent cardiomyopathy, megaoesophagus and megacolon and (v reduce or eliminate cardiac block and arrhythmia. All cases of the indeterminate chronic form of Chagas disease without contraindications due to other concomitant diseases or pregnancy should be treated and not only cases involving children or recently infected cases. Patients with chronic Chagas cardiomyopathy grade II of the New York Heart Association classification should be treated with specific chemotherapy and grade III can be treated according to medical-patient decisions. We are proposing the following new strategies for chemotherapeutic treatment of the chronic phase of Chagas disease: (i repeated short-term treatments for 30 consecutive days and interval of 30-60 days for six months to one year and (ii combinations of drugs with different mechanisms of action, such as benznidazole + nifurtimox, benznidazole or nifurtimox + allopurinol or triazole antifungal agents, inhibition of sterol synthesis.

  3. La enfermedad de Chagas ya no es tan exótica

    Centers for Disease Control (CDC) Podcasts

    Este podcast tiene el propósito de informar a los profesionales de la salud sobre la enfermedad de Chagas, su diagnóstico y tratamiento, así como orientar en la identificación de pacientes infectados.

  4. Probable brote de transmisión oral de enfermedad de Chagas en Turbo, Antioquia

    Directory of Open Access Journals (Sweden)

    Juan Fernando Ríos

    2011-03-01

    Conclusión. Se identificó un probable brote agudo de enfermedad de Chagas en Antioquia y se plantea como hipótesis la transmisión por vía oral, mediante la ingestión de T. cruzi en alimentos contaminados con restos de triatominos o excrementos de marsupiales.

  5. Challenges and opportunities for primary, secondary, and tertiary prevention of Chagas' disease.

    Science.gov (United States)

    Rassi, A; Dias, J C P; Marin-Neto, J A; Rassi, A

    2009-04-01

    A century after its discovery, Chagas' disease still represents a major public health challenge in Latin America. Moreover, because of growing population movements, an increasing number of cases of imported Chagas' disease have now been detected in non-endemic areas, such as North America and some European countries. This parasitic zoonosis, caused by Trypanosoma cruzi, is transmitted to humans by infected Triatominae insects, or occasionally by non-vectorial mechanisms, such as blood transfusion, mother to fetus, or oral ingestion of materials contaminated with parasites. Following the acute phase of the infection, untreated individuals enter a chronic phase that is initially asymptomatic or clinically unapparent. Usually, a few decades later, 40-50% of patients develop progressive cardiomyopathy and/or motility disturbances of the oesophagus and colon. In the last decades several interventions targeting primary, secondary and tertiary prevention of Chagas' disease have been attempted. While control of both vectorial and blood transfusion transmission of T cruzi (primary prevention) has been successful in many regions of Latin America, early detection and aetiological treatment of asymptomatic subjects with Chagas' disease (secondary prevention) have been largely underutilised. At the same time, in patients with established chronic disease, several pharmacological and non-pharmacological interventions are currently available and have been increasingly used with the intention of preventing or delaying complications of the disease (tertiary prevention). In this review we discuss in detail each of these issues.

  6. Trypanosoma cruzi in the chicken model: Chagas-like heart disease in the absence of parasitism

    Czech Academy of Sciences Publication Activity Database

    Teixeira, A.R.L.; Gomes, C.; Nitz, N.; Sousa, A.O.; Alvez, R.M.; Guimaro, M.C.; Cordeiro, C.; Bernal, F.M.; Rosa, A.C.; Hejnar, Jiří; Leonardecz, E.; Hecht, M.M.

    2011-01-01

    Roč. 5, č. 3 (2011), e1000 ISSN 1935-2735 Institutional research plan: CEZ:AV0Z50520514 Keywords : Chagas disease * Trypanosoma cruzi * kDNA minicircles * inbred chicken Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.716, year: 2011

  7. XeCl excimer laser with new prism resonator configurations and its performance characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Benerji, N. S., E-mail: nsb@rrcat.gov.in, E-mail: bsingh@rrcat.gov.in; Singh, A.; Varshnay, N.; Singh, Bijendra, E-mail: nsb@rrcat.gov.in, E-mail: bsingh@rrcat.gov.in [Excimer Laser Section, LMPD, Raja Ramanna Center for Advanced Technology, Indore 452013 (India)

    2015-07-15

    New resonator cavity configurations, namely, the prism resonator and unstable prism resonator, are demonstrated for the first time in an excimer (XeCl) laser with interesting and novel results. High misalignment tolerance ∼50 mrad is achieved with considerably reduced beam divergence of less than ∼1 mrad without reduction in output power capabilities of the laser. The misalignment tolerance of ∼50 mrad is a dramatic improvement of ∼25 times compared to ∼2 mrad normally observed in standard excimer laser with plane-plane cavity. Increase in depth of focus from 3 mm to 5.5 mm was also achieved in case of prism resonator configuration with an improvement of about 60%. Unstable prism resonator configuration is demonstrated here in this paper with further reduction in beam divergence to about 0.5 mrad using plano-convex lens as output coupler. The misalignment tolerance in case of unstable prism resonator was retained at about 30 mrad which is a high value compared to standard unstable resonators. The output beam spot was completely filled with flat-top profile with prism resonator configurations, which is desired for various material processing applications. Focusing properties and beam divergence in case of prism resonator have been investigated using SEM (scanning electron microscope) images. SEM images of the focused spot size (∼20 μm holes) on metal sheet indicate beam divergence of about 0.05 mrad which is about 1.5 times diffraction limit. Energy contained in this angle is thus sufficient for micro-machining applications. Clean and sharp edges of the micro-holes show high pointing stability with multiple shot exposures. Such characteristics of the excimer laser system will be extremely useful in micro-machining and other field applications.

  8. Prism adaptation does not alter object-based attention in healthy participants

    Science.gov (United States)

    Bultitude, Janet H.

    2013-01-01

    Hemispatial neglect (‘neglect’) is a disabling condition that can follow damage to the right side of the brain, in which patients show difficulty in responding to or orienting towards objects and events that occur on the left side of space. Symptoms of neglect can manifest in both space- and object-based frames of reference. Although patients can show a combination of these two forms of neglect, they are considered separable and have distinct neurological bases. In recent years considerable evidence has emerged to demonstrate that spatial symptoms of neglect can be reduced by an intervention called prism adaptation. Patients point towards objects viewed through prismatic lenses that shift the visual image to the right. Approximately five minutes of repeated pointing results in a leftward recalibration of pointing and improved performance on standard clinical tests for neglect. The understanding of prism adaptation has also been advanced through studies of healthy participants, in whom adaptation to leftward prismatic shifts results in temporary neglect-like performance. Here we examined the effect of prism adaptation on the performance of healthy participants who completed a computerised test of space- and object-based attention. Participants underwent adaptation to leftward- or rightward-shifting prisms, or performed neutral pointing according to a between-groups design. Significant pointing after-effects were found for both prism groups, indicating successful adaptation. In addition, the results of the computerised test revealed larger reaction-time costs associated with shifts of attention between two objects compared to shifts of attention within the same object, replicating previous work. However there were no differences in the performance of the three groups, indicating that prism adaptation did not influence space- or object-based attention for this task. When combined with existing literature, the results are consistent with the proposal that prism

  9. Technological innovation strategies for the specific treatment of Chagas disease based on Benznidazole.

    Science.gov (United States)

    Ferraz, Leslie Raphael de Moura; Alves, Alinne Élida Gonçalves; Nascimento, Débora Dolores Souza da Silva; Amariz, Isabela Araújo E; Ferreira, Aline Silva; Costa, Salvana Priscylla Manso; Rolim, Larissa Araújo; Lima, Ádley Antonini Neves de; Rolim Neto, Pedro José

    2018-02-13

    Caused by Trypanosoma cruzi, Chagas disease is responsible for public health problems greater in magnitude than those attributed to malaria, schistosomiasis, or leishmaniasis. A factor in the socioeconomic development of poor countries, Chagas disease can cause death due to a high parasitic burden during its acute phase due and irreversible damage in organs such as the heart, esophagus, and colon during its chronic phase, even when the number of parasites is minimal. For treating Chagas disease, benznidazole (BNZ) remains the drug of choice and, in Latin America, the only drug on the market for treating the disease. However, BNZ has exhibited insufficient activity in the chronic phase of Chagas disease, required administration in large doses, prolonged treatment, and shown a high incidence of adverse reactions (vomiting, rash, peripheral neuropathy, and spinal cord depression), toxicity, and low solubility in water. As an antidote, pharmaceutical technologies have been introduced that can improve BNZ's solubility and dissolution, as well as reduce side effects in light of its bioavailability, all of which can enhance therapy for Chagas disease. In response to that trend, by conducting a literature review, we sought to identify current pharmaceutical technologies used in tandem with BNZ to improve therapy for Chagas disease. Documented techniques include emulsion and microemulsion formation, solutions, parenteral formulas, micronization, and drug delivery systems supported by the development of nanoparticles and cyclodextrins, solid dispersions, and the use of metal-organic frameworks as innovative excipients. Such technologies increase the water solubility of BNZ by 4-25-fold on dissolution and an 85% release with efficacy in only a few minutes, as recorded during a viability experiment with nanoparticle suspensions. That experiment demonstrated the need for a lower concentration of BNZ to kill 50% of trypomastigote forms of T. cruzi, described in terms of the

  10. Esophageal striated muscle contractions in patients with Chagas' disease and idiopathic achalasia

    Directory of Open Access Journals (Sweden)

    R.O. Dantas

    2002-06-01

    Full Text Available Chagas' disease causes degeneration and reduction of the number of intrinsic neurons of the esophageal myenteric plexus, with consequent absent or partial lower esophageal sphincter relaxation and loss of peristalsis in the esophageal body. The impairment of esophageal motility is seen mainly in the distal smooth muscle region. There is no study about esophageal striated muscle contractions in the disease. In 81 patients with heartburn (44 with esophagitis taken as controls, 51 patients with Chagas' disease (21 with esophageal dilatation and 18 patients with idiopathic achalasia (11 with esophageal dilatation we studied the amplitude, duration and area under the curve of esophageal proximal contractions. Using the manometric method and a continuous perfusion system we measured the esophageal striated muscle contractions 2 to 3 cm below the upper esophageal sphincter after swallows of a 5-ml bolus of water. There was no significant difference in striated muscle contractions between patients with heartburn and esophagitis and patients with heartburn without esophagitis. There was also no significant difference between patients with heartburn younger or older than 50 years or between men and women or in esophageal striated muscle contractions between patients with heartburn and Chagas' disease. The esophageal proximal amplitude of contractions was lower in patients with idiopathic achalasia than in patients with heartburn. In patients with Chagas' disease there was no significant difference between patients with esophageal dilatation and patients with normal esophageal diameter. Esophageal striated muscle contractions in patients with Chagas' disease have the same amplitude and duration as seen in patients with heartburn. Patients with idiopathic achalasia have a lower amplitude of contraction than patients with heartburn.

  11. Morphologic and morphometric evaluation of pancreatic islets in chronic Chagas' disease

    Directory of Open Access Journals (Sweden)

    Saldanha João Carlos

    2001-01-01

    Full Text Available PURPOSE: Hyperglycemia and abnormal glucose tolerance tests observed in some patients with chronic Chagas' disease suggest the possibility of morphological changes in pancreatic islets and/or denervation. The purpose of this study was to describe the morphology and morphometry of pancreatic islets in chronic Chagas' disease. METHODS: Morphologic and computerized morphometric studies were performed in fragments of the head, body, and tail regions of the pancreas obtained at necropsies of 8 normal controls and 17 patients with chronic Chagas' disease: 8 with the digestive form (Megas and 9 with the congestive heart failure form. RESULTS: The Megas group had a larger (p < 0.05 pancreatic islet area in the tail of the pancreas (10649.3 ± 4408.8 µm² than the normal control (9481.8 ± 3242.4 µm² and congestive heart failure (9475.1 ± 2104.9 µm² groups; likewise, the density of the pancreatic islets (PI was greater (1.2 ± 0.7 vs. 0.9 ± 0.6 vs. 1.9 ± 1.0 PI/mm², respectively. In the tail region of the pancreas of patients with the Megas form, there was a significant and positive correlation (r = +0.73 between the area and density of pancreatic islets. Discrete fibrosis and leukocytic infiltrates were found in pancreatic ganglia and pancreatic islets of the patients with Chagas' disease. Trypanosoma cruzi nests were not observed in the examined sections. Individuals with the Megas form of Chagas' disease showed increased area and density of pancreatic islets in the tail of the pancreas. CONCLUSION: The observed morphometric and morphologic alterations are consistent with functional changes in the pancreas, including glycemia and insulin disturbances.

  12. Omega-3 supplementation on inflammatory markers in patients with chronic Chagas cardiomyopathy: a randomized clinical study.

    Science.gov (United States)

    Silva, Paula Simplício da; Mediano, Mauro Felippe Felix; Silva, Gilberto Marcelo Sperandio da; Brito, Patricia Dias de; Cardoso, Claudia Santos de Aguiar; Almeida, Cristiane Fonseca de; Sangenis, Luiz Henrique Conde; Pinheiro, Roberta Olmo; Hasslocher-Moreno, Alejandro Marcel; Brasil, Pedro Emmanuel Alvarenga Americano do; Sousa, Andrea Silvestre de

    2017-06-09

    Several studies have been focusing on the effect of omega-3 polyunsaturated fatty acids on modulation of inflammatory markers in several cardiopathies. Although immunoregulatory dysfunction has been associated to the chronic cardiac involvement in Chagas disease, there is no study examining the effects of omega-3 supplementation in these patients. We investigated the effects of omega-3 PUFAs on markers of inflammation and lipid profile in chronic Chagas cardiomyopathy patients. The present study was a single-center double-blind clinical trial including patients with chronic Chagas cardiomyopathy. Patients were randomly assigned to receive omega-3 PUFAs capsules (1.8g EPA and 1.2g DHA) or placebo (corn oil) during an 8-week period. Cytokines, fasting glucose, lipid, and anthropometric profiles were evaluated. Forty-two patients (23 women and 19 men) were included in the study and there were only two losses to follow-up during the 8-week period. Most of sociodemographic and clinical characteristics were similar between the groups at baseline, except for the cytokines IL-1β, IL-6, IL-8, IL-10, IL-17α, and IFNγ. The omega-3 PUFAs group demonstrated greater improvements in serum triglycerides (-21.1 vs. -4.1; p = 0.05) and IL-10 levels (-10.6 vs. -35.7; p = 0.01) in comparison to controls after 8 weeks of intervention. No further differences were observed between groups. Omega-3 PUFAs supplementation may favorably affect lipid and inflammatory profile in chronic Chagas cardiomyopathy patients, demonstrated by a decrease in triglycerides and improvements on IL-10 concentration. Further studies examining the clinical effects of omega-3 fatty acids supplementation in chronic Chagas cardiomyopathy are necessary. NCT01863576.

  13. Pictorial Representation of Illness and Self Measure (PRISM): A novel visual instrument to measure quality of life in dermatological inpatients.

    Science.gov (United States)

    Mühleisen, Beda; Büchi, Stefan; Schmidhauser, Simone; Jenewein, Josef; French, Lars E; Hofbauer, Günther F L

    2009-07-01

    To validate the PRISM (Pictorial Representation of Illness and Self Measure) tool, a novel visual instrument, for the assessment of health-related quality of life in dermatological inpatients compared with the Dermatology Life Quality Index (DLQI) and the Skindex-29 questionnaires and to report qualitative information on PRISM. In an open longitudinal study, PRISM and Skindex-29 and DLQI questionnaires were completed and HRQOL measurements compared. Academic dermatological inpatient ward. The study population comprised 227 sequential dermatological inpatients on admission. Patients completed the PRISM tool and the Skindex-29 and DLQI questionnaires at admission and discharge. PRISM Self-Illness Separation (SIS) score; Skindex-29 and DLQI scores; and qualitative PRISM information by Mayring inductive qualitative context analysis. The PRISM scores correlated well with those from the Skindex-29 (rho = 0.426; P quality of life questionnaires to assess changes in the burden of suffering during hospitalization. Inductive qualitative context analysis revealed impairment of adjustment and self-image as major aspects. Patients overall expected symptomatic and functional improvement. In patients with psoriasis and leg ulcers, many expected no treatment benefit. The PRISM tool proved to be convenient and reliable for health-related quality of life assessment, applicable for a wide range of skin diseases, and correlated with DLQI and Skindex-29 scores. With the PRISM tool, free-text answers allow for the assessment of individual information and potentially customized therapeutic approaches.

  14. RECUERDO DEL DESCUBRIMIENTO DE LA ENFERMEDAD DE CHAGAS

    Directory of Open Access Journals (Sweden)

    Hernando Groot Liévano

    2016-12-01

    momentos, al rememorar a Carlos Chagas, se haga un breve recuento de aquellas condiciones en las cuales se descubrió esta enfermedad y cómo se movieron los mecanismos de su prodigiosa inteligencia y de su instinto clínico para descubrir tal dolencia. Recordemos por un momento la verdadera ebullición científica que había a principios del siglo una vez se conocieron los descubrimientos de Pasteur, luego los de Koch sobre la tuberculosis, y los de Yersin sobre la peste, así como los de Ross y Grassi al descubrir el modo de transmisión del paludismo para no citar sino unos ejemplos de los formidables avances de la medicina entonces.

    Nuestros jóvenes en América, entusiasmados con tantos progresos ansiaban ir a Europa para beber en París la ciencia nueva que abría perspectivas magníficas para la solución de muchos problemas. Aquí, hace unos pocos días recordábamos como, por ejemplo, Luis Zea Uribe se desplaza a Europa y al tornar trae las ideas de establecer un sistema de diagnóstico adecuado para las enfermedades tropicales que se inicia con el de la fiebre tifoidea; y si pasamos a Venezuela, allá José Gregario Hernández y Luis Razetti, con ideas similares, abren en Caracas un laboratorio para tales fines, mucho más precozmente que nosotros, y Carlos Mabran, en Buenos Aires, hace otro tanto.

    El Brasil no se queda atrás, muchas gentes retornan de Europa con un entusiasmo extraordinario; entre ellas se destaca Oswaldo Goncalves Cruz, quien al llegar a Río recibe la noticia de que una enfermedad muy seria está matando la gente en Santos. El Gobierno le encarga el estudio de la situación y es precisamente hace hoy un siglo, el 23 de octubre de 1899, cuando se encuentra con el primer enfermo y le diagnostica clínica y bacteriológicamente peste bubónica. Esta enfermedad, que estaba cobrando muchas víctimas, hace que el Gobierno de Brasil decida establecer un laboratorio para producir suero y vacuna contra el terrible mal transmitido por las

  15. Beyond the sensorimotor plasticity: cognitive expansion of prism adaptation in healthy individuals.

    Directory of Open Access Journals (Sweden)

    Carine eMICHEL

    2016-01-01

    Full Text Available Sensorimotor plasticity allows us to maintain an efficient motor behavior in reaction to environmental changes. One of the classical models for the study of sensorimotor plasticity is prism adaptation. It consists of pointing to visual targets while wearing prismatic lenses that shift the visual field laterally. The conditions of the development of the plasticity and the sensorimotor after-effects have been extensively studied for more than a century. However, the interest taken in this phenomenon was considerably increased since the demonstration of neglect rehabilitation following prism adaptation by Rossetti and his colleagues in 1998. Mirror effects, i.e. simulation of neglect in healthy individuals, were observed for the first time by Colent and collaborators in 2000. The present review focuses on the expansion of prism adaptation to cognitive functions in healthy individuals during the last 15 years. Cognitive after-effects have been shown in numerous tasks even in those that are not intrinsically spatial in nature. Altogether, these results suggest the existence of a strong link between low-level sensorimotor plasticity and high-level cognitive functions and raise important questions about the mechanisms involved in producing unexpected cognitive effects following prism adaptation. Implications for the functional mechanisms and neuroanatomical network of prism adaptation are discussed to explain how sensorimotor plasticity may affect cognitive processes.

  16. Porous Ni-Co-Mn oxides prisms for high performance electrochemical energy storage

    Science.gov (United States)

    Zhao, Jianbo; Li, Man; Li, Junru; Wei, Chengzhen; He, Yuyue; Huang, Yixuan; Li, Qiaoling

    2017-12-01

    Porous Ni-Co-Mn oxides prisms have been successfully synthesized via a facile route. The process involves the preparation of nickel-cobalt-manganese acetate hydroxide by a simple co-precipitation method and subsequently the thermal treatment. The as-synthesized Ni-Co-Mn oxides prisms had a large surface area (96.53 m2 g-1) and porous structure. As electrode materials for supercapacitors, porous Ni-Co-Mn oxides prisms showed a high specific capacitance of 1623.5 F g-1 at 1.0 A g-1. Moreover, the porous Ni-Co-Mn oxides prisms were also employed as positive electrode materials to assemble flexible solid-state asymmetric supercapacitors. The resulting flexible device had a maximum volumetric energy density (0.885 mW h cm-3) and power density (48.9 mW cm-3). Encouragingly, the flexible device exhibited good cycling stability with only about 2.2% loss after 5000 charge-discharge cycles and excellent mechanical stability. These results indicate that porous Ni-Co-Mn oxides prisms have the promising application in high performance electrochemical energy storage.

  17. Fusional Vergence Detected by Prism Bar and Synoptophore in Chinese Childhood Intermittent Exotropia

    Directory of Open Access Journals (Sweden)

    Tao Fu

    2015-01-01

    Full Text Available Purpose. To measure the changes in fusional vergence in Chinese children with intermittent exotropia (IXT and the association with the control of IXT. Methods. Ninety-two patients with IXT (8–15 years old were compared with 86 controls. Exodeviation control was evaluated using the Revised Newcastle Control Score. Angle of deviation was measured using prism and alternate cover testing at distance and near. Fusional vergence was measured using prism bar and synoptophore. This study was registered with ChiCTR-RCC-13003920. Results. Using prism bar, convergence break points were lower whereas divergence break points were higher in children with IXT at distance (P<0.001 and near (P<0.001 compared with controls. There was no significant difference in mean divergence amplitudes between the two groups when testing using a synoptophore (P=0.53. In children with IXT, the distance between recovery point and break point in both convergence (distance: P=0.02; near: P=0.02 and divergence (distance: P<0.001; near: P<0.001 was larger than controls when detected by prism bar and synoptophore (convergence: P=0.005; divergence: P=0.006. Conclusions. Children with IXT have reduced convergence amplitudes as detected by both prism bar and synoptophore.

  18. Affective three-dimensional brain-computer interface created using a prism array-based display

    Science.gov (United States)

    Mun, Sungchul; Park, Min-Chul

    2014-12-01

    To avoid the vergence-accommodation mismatch and provide a strong sense of presence to users, we applied a prism array-based display when presenting three-dimensional (3-D) objects. Emotional pictures were used as visual stimuli to increase the signal-to-noise ratios of steady-state visually evoked potentials (SSVEPs) because involuntarily motivated selective attention by affective mechanisms can enhance SSVEP amplitudes, thus producing increased interaction efficiency. Ten male and nine female participants voluntarily participated in our experiments. Participants were asked to control objects under three viewing conditions: two-dimension (2-D), stereoscopic 3-D, and prism. The participants performed each condition in a counter-balanced order. One-way repeated measures analysis of variance showed significant increases in the positive predictive values in the prism condition compared to the 2-D and 3-D conditions. Participants' subjective ratings of realness and engagement were also significantly greater in the prism condition than in the 2-D and 3-D conditions, while the ratings for visual fatigue were significantly reduced in the prism condition than in the 3-D condition. The proposed methods are expected to enhance the sense of reality in 3-D space without causing critical visual fatigue. In addition, people who are especially susceptible to stereoscopic 3-D may be able to use the affective brain-computer interface.

  19. [Pancreatic neuronal loss in chronic Chagas' disease patients].

    Science.gov (United States)

    Rocha, A; de Oliveira, L C; Alves, R S; Lopes, E R

    1998-01-01

    We have not found any anatomical studies about the intrapancreatic ganglia in the chronic Chagas' disease. The lesions in these structures could explain at least in part the functional disturbances in the exocrine and endocrine pancreas described in this form of the disease. Thus we decided to morphologically analyze these ganglia. For this analysis, we studied transversal segments of the head, body and tail of the pancreas of twelve chronic chagasics whose mean age were 46.5 +/- 9.1 years and fourteen controls, mean age 41.2 +/- 11.0 years. These segments were histologically processed and cut into sections in a serial form up to the end and one cut of each seven was analyzed. For statistical analysis we used the non-parametric test of Mann-Whitney. In the head of the pancreas, the mean count of neurons was 57.3 +/- 50.8 in the chagasic group and 117.5 +/- 99.0 for the control group (p < 0.05); in the body 25.9 +/- 19.4 for the chagasic group and 54.7 +/- 47.8 for the control group (p < 0.05); in the tail 23.4 +/- 16.3 for the chagasic group and 54.1 +/- 29.2 for the control group (p < 0.01), the total count being 106.6 +/- 71.1 for the chagasic group and 226.3 +/- 156.5 for the controls (p < 0.01). Our data permitted us to conclude that: a) there was a statistically significant neuronal depopulation in the chagasic group, as compared to the control group, in each pancreatic segment that was analyzed, as well as in the organ as a whole; b) 50% of the chagasics had the total number of neurons smaller than the lowest number observed in the controls (80); c) 75% and 91.6% of the chagasics had the number of neurons smaller than, respectively, the median (171) and the mean (226) of the control group; d) therefore, the pancreatic neuronal depopulation was common, but not constant; e) the variable age was apparently not responsible for the neuronal depopulation of the chagasics.

  20. Brain Chagas'disease: increasing differential diagnosis of brain mass in immunosuppressed patients - a case report and literature revision

    International Nuclear Information System (INIS)

    Batista, Laercio Leitao; centola, Crescencio A.P.; Kakudate, Milton Y.

    1995-01-01

    The authors present a case of Chagas'disease as tumor-like lesion of the brain, in a patient with Aids, simulating the lesions most frequently found in these patients, as toxoplasmosis, lymphoma and cryptococcosis. Furthermore, the case reported have peculiarity to be the only with lesion documented in cerebellum, and unusual due to be secondary by reactivation of chronic Chagas disease. Moreover, emphasize analysis of cerebrospinal fluid with realization of sorologic tests to Chagas's disease, as simple as effective method, to make use of biopsy with stereotaxia in unfinished cases and bad evolution. Finally, after a wide world literature review about Chagas'disease as a tumor-like lesion of the brain, emphasizing this publication as the first written in a radiology journal of specialty. (author). 40 refs., 3 figs., 1 tab

  1. Role of T. cruzi exposure in the pattern of T cell cytokines among chronically infected HIV and Chagas disease patients

    Directory of Open Access Journals (Sweden)

    Tania Regina Tozetto-Mendoza

    Full Text Available OBJECTIVES: The impact of Chagas disease (CD in HIV-infected patients is relevant throughout the world. In fact, the characterization of the adaptive immune response in the context of co-infection is important for predicting the need for interventions in areas in which HIV and Chagas disease co-exist. METHODS: We described and compared the frequency of cytokine-producing T cells stimulated with soluble antigen of Trypanosoma cruzi (T. cruzi using a cytometric assay for the following groups: individuals with chronic Chagas disease (CHR, n=10, those with Chagas disease and HIV infection (CO, n=11, those with only HIV (HIV, n=14 and healthy individuals (C, n=15. RESULTS: We found 1 a constitutively lower frequency of IL-2+ and IFN-γ+ T cells in the CHR group compared with the HIV, CO and healthy groups; 2 a suppressive activity of soluble T. cruzi antigen, which down-regulated IL-2+CD4+ and IFN-γ+CD4+ phenotypes, notably in the healthy group; 3 a down-regulation of inflammatory cytokines on CD8+ T cells in the indeterminate form of Chagas disease; and 4 a significant increase in IL-10+CD8+ cells distinguishing the indeterminate form from the cardiac/digestive form of Chagas disease, even in the presence of HIV infection. CONCLUSIONS: Taken together, our data suggest the presence of an immunoregulatory response in chronic Chagas disease, which seems to be driven by T. cruzi antigens. Our findings provide new insights into immunotherapeutic strategies for people living with HIV/AIDS and Chagas disease.

  2. Pacemaker Implants in Children and Adolescents with Chagas Disease in Brazil: 18-Year Incidence.

    Science.gov (United States)

    Mizzaci, Carolina Christianini; Souza, Thiago Gonçalves Schroder E; Targueta, Gabriel Pelegrineti; Tótora, Ana Paula Frederico; Mateos, Juan Carlos Pachón; Mateos, José Carlos Pachon

    2017-06-01

    Chagas disease continues to be a serious public health problem, and accounts for 25-30% of the indications for cardiac stimulation in Brazil. To assess clinical and epidemiological characteristics of patients with Chagas disease, younger than 18 years, who had undergone pacemaker implantation in Brazil between 1994 and 2011, and its temporal trend. This was a cross-sectional analysis of data from the Brazilian Pacemaker Registry database. The following variables were analyzed: year when pacemaker was implanted, location, age, sex, ethnic group, functional class and the main electrocardiographic findings at baseline. In a total of 183,123 implants performed between 1994 and 2011, 214 implants of cardiac stimulation device in Chagas disease patients aged younger than 18 years were identified. Mean age at implantation was 5.6 ± 6.2 years. Second- and third-degree atrioventricular blocks corresponded to 71% of indications for pacemaker implantation. Fifty-six percent of the procedures were performed in the southeast region. Regarding the total number of pacemaker implants per year, there was a remarkable increase in the implants for all causes. However, time series analysis of the implants in Chagas disease patients younger than 18 years revealed a significant reduction in the annual number of implants. There has been an important reduction in the number of pacemaker implantations among children and adolescents with Chagas disease, suggesting a reduction in the vertical transmission of the parasite. A doença de Chagas mantém-se como sério problema de saúde pública e tem sido responsável por aproximadamente 25% a 30% das indicações de estimulação cardíaca no Brasil. Estudar as características clínicas e epidemiológicas dos pacientes menores de 18 anos portadores de doença de Chagas submetidos a implante de marca-passo no território brasileiro entre 1994 e 2011, e sua tendência temporal. Trata-se de um estudo retrospectivo que utilizou informa

  3. Single-Frequency Nd:YAG Ring Lasers with Corner Cube Prism

    Science.gov (United States)

    Wu, Ke-Ying; Yang, Su-Hui; Zhao, Chang-Ming; Wei, Guang-Hui

    2000-10-01

    We put forward another form of the non-planar ring lasers, in which the corner cube prism is the key element and the Nd:YAG crystal is used as a Porro prism to enclose the ring resonator. The phase shift due to the total internal reflections of the three differently orientated reflection planes of the corner cube prism, Faraday rotation in the Nd:YAG crystal placed in a magnetic field and the different output coupling in S and P polarization form an optical diode and enforce the single-frequency generating power. A round trip analysis of the polarization properties of the resonator is made by the evaluation of Jones matrix.

  4. Laser Oscillator Incorporating a Wedged Polarization Rotator and a Porro Prism as Cavity Mirror

    Science.gov (United States)

    Li, Steven

    2011-01-01

    A laser cavity was designed and implemented by using a wedged polarization rotator and a Porro prism in order to reduce the parts count, and to improve the laser reliability. In this invention, a z-cut quartz polarization rotator is used to compensate the wavelength retardance introduced by the Porro prism. The polarization rotator rotates the polarization of the linear polarized beam with a designed angle that is independent of the orientation of the rotator. This unique property was used to combine the retardance compensation and a Risley prism to a single optical component: a wedged polarization rotator. This greatly simplifies the laser alignment procedure and reduces the number of the laser optical components.

  5. Numerical and experimental evaluation of masonry prisms by finite element method

    Directory of Open Access Journals (Sweden)

    C. F.R. SANTOS

    Full Text Available Abstract This work developed experimental tests and numerical models able to represent the mechanical behavior of prisms made of ordinary and high strength concrete blocks. Experimental tests of prisms were performed and a detailed micro-modeling strategy was adopted for numerical analysis. In this modeling technique, each material (block and mortar was represented by its own mechanical properties. The validation of numerical models was based on experimental results. It was found that the obtained numerical values of compressive strength and modulus of elasticity differ by 5% from the experimentally observed values. Moreover, mechanisms responsible for the rupture of the prisms were evaluated and compared to the behaviors observed in the tests and those described in the literature. Through experimental results it is possible to conclude that the numerical models have been able to represent both the mechanical properties and the mechanisms responsible for failure.

  6. Os experimentos prismáticos de Goethe Goethe's prismatic experiments

    Directory of Open Access Journals (Sweden)

    Fred Jordan

    1993-12-01

    Full Text Available O ensaio pretende estimular a realização de experimentos prismáticos com recursos muito simples e, com isso, facilitar o acesso aos fundamentais estudos de Goethe sobre cor, a "Farbenlehre". O encarte anexo contém fotos de um processo prismático complementar, produzido por Imagens-Modelo em Claro-Escuro neutro. Contém ainda fotos de imagens prismáticas produzidas por Imagens-Modelo em cores.The essay intends to stimulate the carrying out of prismatic experiments with very simple resources and, therewith, ease the access to Goethe's fundamental color studies, the "Farbenlehre". The included folder contains photographs of a complementary prismatic process produced by neutral bright-dark Model-Images. It also contains photographs of prismatic images produced by colored Model-Images.

  7. Evaluation of the Chagas Stat-Paktm Assay for Detection of Trypanosoma cruzi Antibodies in Wildlife Reservoirs

    Science.gov (United States)

    Yabsley, Michael J.; Brown, Emily L.; Roellig, Dawn M.

    2010-01-01

    An immunochromatographic assay (Chagas Stat-Pak™) was evaluated for the detection of Trypanosoma cruzi antibodies in 4 species of wildlife reservoirs. Antibodies to T. cruzi were detected in raccoons (Procyon lotor) (naturally and experimentally infected) and degus (Octodon degu) (experimentally-infected) using the Chagas Stat-Pak. In naturally exposed wild raccoons, the Chagas Stat-Pak had a sensitivity and specificity of 66.7–80.0% and 96.3%, respectively. Compared with indirect immunofluorescent antibody assay results, serocon-version as determined by Chagas Stat-Pak was delayed for experimentally infected raccoons, but occurred sooner in experimentally infected degus. The Chagas Stat-Pak did not detect antibodies in naturally or experimentally infected Virginia opossums (Didelphis virginiana) or in experimentally infected short-tailed opossums (Monodelphis domestica). These data suggest that the Chagas Stat-Pak might be useful in field studies of raccoons and degus when samples would not be available for more-conventional serologic assays. Because this assay did not work on either species of marsupial, the applicability of the assay should be examined before it is used in other wild species. PMID:19016578

  8. Spherical Lenses and Prisms Lead to Postural Instability in Both Dyslexic and Non Dyslexic Adolescents

    Science.gov (United States)

    Kapoula, Zoi; Gaertner, Chrystal; Matheron, Eric

    2012-01-01

    There is controversy as to whether dyslexic children present systematic postural deficiency. Clinicians use a combination of ophthalmic prisms and proprioceptive soles to improve postural performances. This study examines the effects of convergent prisms and spherical lenses on posture. Fourteen dyslexics (13–17 years-old) and 11 non dyslexics (13–16 years-old) participated in the study. Quiet stance posturography was performed with the TechnoConcept device while subjects fixated a target at eye-level from a distance of 1_m. Four conditions were run: normal viewing; viewing the target with spherical lenses of −1 diopter (ACCOM1) over each eye; viewing with −3 diopters over each eye (ACCOM3); viewing with a convergent prism of 8 diopters per eye. Relative to normal viewing, the −1 lenses increased the surface of body sway significantly whereas the −3 diopter lenses only resulted in a significant increase of antero-posterior body sway. Thus, adolescents would appear to cope more effectively with stronger conflicts rather than subtle ones. The prism condition resulted in a significant increase in both the surface and the antero-posterior body sway. Importantly, all of these effects were similar for the two groups. Wavelet analysis (time frequency domain) revealed high spectral power of antero-posterior sway for the prism condition in both groups. In the ACCOM3 condition, the spectral power of antero-posterior sway decreased for non dyslexics but increased for dyslexics suggesting that dyslexics encounter more difficulty with accommodation. The cancelling time for medium range frequency (believed to be controlled by the cerebellum), was shorter in dyslexics, suggesting fewer instances of optimal control. We conclude that dyslexics achieve similar postural performances albeit less efficiently. Prisms and lenses destabilize posture for all teenagers. Thus, contrary to adults, adolescents do not seem to use efferent, proprioceptive ocular motor signals to

  9. Spherical lenses and prisms lead to postural instability in both dyslexic and non dyslexic adolescents.

    Directory of Open Access Journals (Sweden)

    Zoi Kapoula

    Full Text Available There is controversy as to whether dyslexic children present systematic postural deficiency. Clinicians use a combination of ophthalmic prisms and proprioceptive soles to improve postural performances. This study examines the effects of convergent prisms and spherical lenses on posture. Fourteen dyslexics (13-17 years-old and 11 non dyslexics (13-16 years-old participated in the study. Quiet stance posturography was performed with the TechnoConcept device while subjects fixated a target at eye-level from a distance of 1_m. Four conditions were run: normal viewing; viewing the target with spherical lenses of -1 diopter (ACCOM1 over each eye; viewing with -3 diopters over each eye (ACCOM3; viewing with a convergent prism of 8 diopters per eye. Relative to normal viewing, the -1 lenses increased the surface of body sway significantly whereas the -3 diopter lenses only resulted in a significant increase of antero-posterior body sway. Thus, adolescents would appear to cope more effectively with stronger conflicts rather than subtle ones. The prism condition resulted in a significant increase in both the surface and the antero-posterior body sway. Importantly, all of these effects were similar for the two groups. Wavelet analysis (time frequency domain revealed high spectral power of antero-posterior sway for the prism condition in both groups. In the ACCOM3 condition, the spectral power of antero-posterior sway decreased for non dyslexics but increased for dyslexics suggesting that dyslexics encounter more difficulty with accommodation. The cancelling time for medium range frequency (believed to be controlled by the cerebellum, was shorter in dyslexics, suggesting fewer instances of optimal control. We conclude that dyslexics achieve similar postural performances albeit less efficiently. Prisms and lenses destabilize posture for all teenagers. Thus, contrary to adults, adolescents do not seem to use efferent, proprioceptive ocular motor signals to

  10. Strategic Planning for Chronic Disease Prevention in Rural America: Looking Through a PRISM Lens.

    Science.gov (United States)

    Honeycutt, Amanda A; Wile, Kristina; Dove, Cassandra; Hawkins, Jackie; Orenstein, Diane

    2015-01-01

    Community-level strategic planning for chronic disease prevention. To share the outcomes of the strategic planning process used by Mississippi Delta stakeholders to prevent and reduce the negative impacts of chronic disease in their communities. A key component of strategic planning was participants' use of the Prevention Impacts Simulation Model (PRISM) to project the reduction, compared with the status quo, in deaths and costs from implementing interventions in Mississippi Delta communities. Participants in Mississippi Delta strategic planning meetings used PRISM, a user-friendly, evidence-based simulation tool that includes 22 categories of policy, systems, and environmental change interventions, to pose what-if questions that explore the likely short- and long-term effects of an intervention or any desired combination of the 22 categories of chronic disease intervention programs and policies captured in PRISM. These categories address smoking, air pollution, poor nutrition, and lack of physical activity. Strategic planning participants used PRISM outputs to inform their decisions and actions to implement interventions. Rural communities in the Mississippi Delta. A diverse group of 29 to 34 local chronic disease prevention stakeholders, known as the Mississippi Delta Strategic Alliance. Community plans and actions that were developed and implemented as a result of local strategic planning. Existing strategic planning efforts were complemented by the use of PRISM. The Mississippi Delta Strategic Alliance decided to implement new interventions to improve air quality and transportation and to expand existing interventions to reduce tobacco use and increase access to healthy foods. They also collaborated with the Department of Transportation to raise awareness and use of the current transportation network. The Mississippi Delta Strategic Alliance strategic planning process was complemented by the use of PRISM as a tool for strategic planning, which led to the

  11. Instantaneous flow field above the free end of finite-height cylinders and prisms

    International Nuclear Information System (INIS)

    Rostamy, N.; Sumner, D.; Bergstrom, D.J.; Bugg, J.D.

    2013-01-01

    Highlights: • PIV measurements of the flow above the free end of finite-height bodies. • Effect of cross-sectional shape of the models on the instantaneous flow. • Small-scale structures generated by the separated shear layer were revealed. • Effect of aspect ratio on the reattachment of the separated flow on the free end. -- Abstract: The flow above the free ends of surface-mounted finite-height circular cylinders and square prisms was studied experimentally using particle image velocimetry (PIV). Cylinders and prisms with aspect ratios of AR = 9, 7, 5, and 3 were tested at a Reynolds number of Re = 4.2 × 10 4 . The bodies were mounted normal to a ground plane and were partially immersed in a turbulent zero-pressure-gradient boundary layer, where the boundary layer thickness relative to the body width was δ/D = 1.6. PIV measurements were made above the free ends of the bodies in a vertical plane aligned with the flow centreline. The present PIV results provide insight into the effects of aspect ratio and body shape on the instantaneous flow field. The recirculation zone under the separated shear layer is larger for the square prism of AR = 3 compared to the more slender prism of AR = 9. Also, for a square prism with low aspect ratio (AR = 3), the influence of the reverse flow over the free end surface becomes more significant compared to that for a higher aspect ratio (AR = 9). For the circular cylinder, a cross-stream vortex forms within the recirculation zone. As the aspect ratio of the cylinder decreases, the reattachment point of the separated flow on the free end surface moves closer to the trailing edge. For both the square prism and circular cylinder cases, the instantaneous velocity vector field and associated in-plane vorticity field revealed small-scale structures mostly generated by the separated shear layer

  12. Assessment and epidemiology of Chagas' disease in patients treated in Araguaina - Tocantins

    International Nuclear Information System (INIS)

    Correa, Valeria Rita

    2010-01-01

    Chagas disease (AD) was described by Carlos Chagas in 1909. It is caused by a parasite T. cruzi, transmitted by bugs, by blood transfusion, vertical and orally. The DC has two phases: acute and chronic. The evolution to the cardiac form occurs in about 30% of chronic cases and is the largest cause of mortality in chronic Chagas disease. The aim of this study was to Chagas' disease in patients of Tocantins, compared with other heart patients and asymptomatic from the standpoint of non-invasive exams using radiant energies such as echocardiography and ECG and RX. The descriptive study included 80 patients, 20 chronic form of Chagas disease, 20 indeterminate, 20 with other heart diseases, and 20 controls. There was a prevalence of 9.5% of chagasic patients treated in outpatient cardiology at Araguaina Tocantins, and 7.3% in chronic and 2.21% in the indeterminate. Of the chronic patients in the study 50% had mega esophagus and megacolon 4 (20%). Most patients had no family history of AD, nor was a smoker or drinker. Major electrocardiographic abnormalities found refer to driving. The evaluation of ICT, the chronic chagasic showed that increased by 40% of patients, 40% had esophageal changes and 20% of patients had megacolon s. The echocardiogram was abnormal in 42%). 27% of patients had EF below 55% changed. Changes in segmental contractility and Asynchrony septum were found in 80% of chronic Chagas disease. In 80% of the patients was observed diastolic dysfunction. The valvular changes occurred in 75%. Electrocardiographic abnormalities occurred in 80% of patients with CCC, while the other heart had ECG changes. Arterial hypertension had an incidence of 45% in patients with CCC and 40% in FCI. The systolic and diastolic ventricular dysfunction was more prevalent in groups that had an abnormal ECG and arrhythmia. Observed that the group of chagasic decreased ejection fraction is correlated to a higher incidence of arrhythmias besides diastolic dysfunction and related

  13. The application of the right rectangular prism in the process determining the value of terrain correction

    Directory of Open Access Journals (Sweden)

    Odalović Oleg R.

    2015-01-01

    Full Text Available The effects of topographic masses on gravity were determined for the territory of Serbia by using the digital terrain model with resolution of 1 arch second in both directions. For the effect of distant masses, i.e. masses that are out of the territory of Serbia, a global digital model SRTM (Shuttle Radar Topography Mission was used. All the topography masses were divided by using a right rectangle prism and classic terrain corrections was applied. Special attention was dedicated to the curvatures of the Earth surface and singularity points, where equations for first partial derivatives of prism gravity potential are not defined.

  14. Evaluation of the Performance of Routine Information System Management (PRISM framework: evidence from Uganda

    Directory of Open Access Journals (Sweden)

    Aqil Anwer

    2010-07-01

    Full Text Available Abstract Background Sound policy, resource allocation and day-to-day management decisions in the health sector require timely information from routine health information systems (RHIS. In most low- and middle-income countries, the RHIS is viewed as being inadequate in providing quality data and continuous information that can be used to help improve health system performance. In addition, there is limited evidence on the effectiveness of RHIS strengthening interventions in improving data quality and use. The purpose of this study is to evaluate the usefulness of the newly developed Performance of Routine Information System Management (PRISM framework, which consists of a conceptual framework and associated data collection and analysis tools to assess, design, strengthen and evaluate RHIS. The specific objectives of the study are: a to assess the reliability and validity of the PRISM instruments and b to assess the validity of the PRISM conceptual framework. Methods Facility- and worker-level data were collected from 110 health care facilities in twelve districts in Uganda in 2004 and 2007 using records reviews, structured interviews and self-administered questionnaires. The analysis procedures include Cronbach's alpha to assess internal consistency of selected instruments, test-retest analysis to assess the reliability and sensitivity of the instruments, and bivariate and multivariate statistical techniques to assess validity of the PRISM instruments and conceptual framework. Results Cronbach's alpha analysis suggests high reliability (0.7 or greater for the indices measuring a promotion of a culture of information, RHIS tasks self-efficacy and motivation. The study results also suggest that a promotion of a culture of information influences RHIS tasks self-efficacy, RHIS tasks competence and motivation, and that self-efficacy and the presence of RHIS staff have a direct influence on the use of RHIS information, a key aspect of RHIS performance

  15. On improvement of the series convergence in the problem of the vibrations of orhotropic rectangular prism

    Science.gov (United States)

    Lyashko, A. D.

    2017-11-01

    A new analytical presentation of the solution for steady-state oscillations of orthotopic rectangular prism is found. The corresponding infinite system of linear algebraic equations has been deduced by the superposition method. A countable set of precise eigenfrequencies and elementary eigenforms is found. The identities are found which make it possible to improve the convergence of all the infinite series in the solution of the problem. All the infinite series in presentation of solution are analytically summed up. Numerical calculations of stresses in the rectangular orthotropic prism with a uniform along the border and harmonic in time load on two opposite faces have been performed.

  16. Chagas disease as a cause of heart failure and ventricular arrhythmias in patients long removed from endemic areas: an emerging problem in Europe.

    Science.gov (United States)

    Vannucchi, Vieri; Tomberli, Benedetta; Zammarchi, Lorenzo; Fornaro, Alessandra; Castelli, Gabriele; Pieralli, Filippo; Berni, Andrea; Yacoub, Sophie; Bartoloni, Alessandro; Olivotto, Iacopo

    2015-12-01

    Chagas disease is a parasitic disease caused by the protozoan Trypanosoma cruzi. In endemic areas (South and Central America), Chagas disease represents a relevant public health issue, and is the most frequent cause of cardiomyopathy. In nonendemic areas, such as Europe, Chagas disease represents an emerging problem following the establishment of sizeable communities from Brazil and Bolivia. Chagas cardiomyopathy represents the most frequent and serious complication of chronic Chagas disease, affecting about 20-30% of patients, potentially leading to heart failure, arrhythmias, thromboembolism, stroke and sudden death. Because late complications of Chagas disease may develop several years or even decades after the acute infection, it may be extremely challenging to reach the correct diagnosis in patients long removed from the countries of origin. We report two examples of Chagas cardiomyopathy in South American women permanently residing in Italy for more than 20 years, presenting with cardiac manifestations ranging from left ventricular dysfunction and heart failure to isolated ventricular arrhythmias. The present review emphasizes that Chagas disease should be considered as a potential diagnosis in patients from endemic areas presenting with 'idiopathic' cardiac manifestations, even when long removed from their country of origin, with potential implications for treatment and control of Chagas disease transmission.

  17. Evolução tardia do transplante cardíaco na doença de Chagas: long-term evolution in cardiac transplantation Chagas' Disease

    Directory of Open Access Journals (Sweden)

    Alfredo I Fiorelli

    1990-08-01

    Full Text Available Nas formas cardíacas da doença de Chagas que evoluem com insuficiência cardíaca refratária ao tratamento clínico, o transplante é a única alternativa, ao lado da cardiomioplastia. Os autores apresentam a evolução tardia de seis pacientes com miocardiopatia chagásica terminal submetidos a transplante cardíaco ortotópico. O período médio de observação foi de 25,2 meses. O diagnóstico de reativação da doença de Chagas apoiou-se na observação clínica, na investigação laboratorial do parasita, nas biópsias endomiocárdicas e dos nódulos de subcutâneo. A análise dos resultados demonstra que: 1 os testes laboratoriais mostraram-se ineficazes no diagnóstico da reativação da doença, sendo que as biópsias mostraram maior índice de positividade; 2 a pulsoterapia com corticóide predispõe à reativação; 3 a doença linfoproliferativa apresenta alta incidência na doença de Chagas, sendo a principal complicação tardia. Possivelmente, o benzonidazol apresente seu efeito oncogênico potencializado. Tendo em vista o caráter endêmico da doença e a falta de alternativa terapêutica, tornou-se obrigatória a analise do esquema imunossupressor, do tratamento da reativação e a maior experiência clínica, para posições mais definidas.In the cardiac forms of Chagas' Disease that develop with refractory cardiac failure under clinical treatment, the transplant is the only alternative along with the cardiomyoplasty. The authors present the six patient late evolution with terminal chagasic myocardiopathy submitted under on orthopic heart transplantation. The average period of observation was of 25.2 months. The diagnosis of Chagas' Disease reativation relies on the clinical observation, laboratory investigation of parasito, endomyocardial biopsy and subcutaneous nodules. The analyses of the results show that: 1 the laboratory exams were useless in the diagnosis of the disease reativation, but the biopsy presented hight

  18. Pictorial Representation of Self and Illness Measure (PRISM): a graphic instrument to assess suffering in fatigued cancer survivors

    NARCIS (Netherlands)

    Gielissen, M.F.M.; Prins, J.B.; Knoop, H.; Verhagen, S.; Bleijenberg, G.

    2013-01-01

    OBJECTIVE: The Pictorial Representation of Self and Illness Measure (PRISM) measures in a simple, graphic way the burden of suffering due to illness. The question addressed in this study is whether the PRISM is a valid instrument to measure suffering in cancer survivors experiencing severe fatigue.

  19. Usefulness of FC-TRIPLEX Chagas/Leish IgG1 as confirmatory assay for non-negative results in blood bank screening of Chagas disease.

    Science.gov (United States)

    Campos, Fernanda Magalhães Freire; Repoles, Laura Cotta; de Araújo, Fernanda Fortes; Peruhype-Magalhães, Vanessa; Xavier, Marcelo Antônio Pascoal; Sabino, Ester Cerdeira; de Freitas Carneiro Proietti, Anna Bárbara; Andrade, Mariléia Chaves; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis; Gontijo, Célia Maria Ferreira

    2018-04-01

    A relevant issue in Chagas disease serological diagnosis regards the requirement of using several confirmatory methods to elucidate the status of non-negative results from blood bank screening. The development of a single reliable method may potentially contribute to distinguish true and false positive results. Our aim was to evaluate the performance of the multiplexed flow-cytometry anti-T. cruzi/Leishmania IgG1 serology/(FC-TRIPLEX Chagas/Leish IgG1) with three conventional confirmatory criteria (ELISA-EIA, Immunofluorescence assay-IIF and EIA/IIF consensus criterion) to define the final status of samples with actual/previous non-negative results during anti-T. cruzi ELISA-screening in blood banks. Apart from inconclusive results, the FC-TRIPLEX presented a weak agreement index with EIA, while a strong agreement was observed when either IIF or EIA/IIF consensus criteria were applied. Discriminant analysis and Spearman's correlation further corroborates the agreement scores. ROC curve analysis showed that FC-TRIPLEX performance indexes were higher when IIF and EIA/IIF consensus were used as a confirmatory criterion. Logistic regression analysis further demonstrated that the probability of FC-TRIPLEX to yield positive results was higher for inconclusive results from IIF and EIA/IIF consensus. Machine learning tools illustrated the high level of categorical agreement between FC-TRIPLEX versus IIF or EIA/IIF consensus. Together, these findings demonstrated the usefulness of FC-TRIPLEX as a tool to elucidate the status of non-negative results in blood bank screening of Chagas disease. Copyright © 2018. Published by Elsevier B.V.

  20. PRISM: Processing routines in IDL for spectroscopic measurements (installation manual and user's guide, version 1.0)

    Science.gov (United States)

    Kokaly, Raymond F.

    2011-01-01

    This report describes procedures for installing and using the U.S. Geological Survey Processing Routines in IDL for Spectroscopic Measurements (PRISM) software. PRISM provides a framework to conduct spectroscopic analysis of measurements made using laboratory, field, airborne, and space-based spectrometers. Using PRISM functions, the user can compare the spectra of materials of unknown composition with reference spectra of known materials. This spectroscopic analysis allows the composition of the material to be identified and characterized. Among its other functions, PRISM contains routines for the storage of spectra in database files, import/export of ENVI spectral libraries, importation of field spectra, correction of spectra to absolute reflectance, arithmetic operations on spectra, interactive continuum removal and comparison of spectral features, correction of imaging spectrometer data to ground-calibrated reflectance, and identification and mapping of materials using spectral feature-based analysis of reflectance data. This report provides step-by-step instructions for installing the PRISM software and running its functions.

  1. Mortalidad por enfermedad de Chagas: A propósito de los brotes de Chagas agudo como enfermedad reemergente de transmisión alimentaria

    OpenAIRE

    Rísquez, Alejandro

    2009-01-01

    Tras la ocurrencia de los primeros brotes de Chagas agudos en la capital (diciembre 2007) y Estado Vargas (marzo 2009) por trasmisión oral, se procedió a una revisión de la mortalidad por la enfermedad registrada entre 1997 y 2006, cuyos datos se analizaron de acuerdo a la edad, sexo y forma de presentación. El número absoluto de muertes sigue siendo elevado con promedio de 796 muertes anuales, de predominio en el sexo masculino, la mayoría en después de los 60 años de edad. Llama la atención...

  2. Sperm Morphological Features Associated with Chronic Chagas Disease in the Semen of Experimentally Infected Dogs

    Science.gov (United States)

    Rodríguez-Morales, Olivia; Pedro-Martínez, Elvia; Hernández-Pichardo, José Ernesto; Alejandre-Aguilar, Ricardo; Aranda-Fraustro, Alberto; Graullera-Rivera, Verónica; Arce-Fonseca, Minerva

    2014-01-01

    The presence of trypanosomatids in the reproductive systems of different mammals (causing genital lesions in the acute stage of the disease) may predispose the animals to low semen quality. However, there are no studies examining the alterations in the sperm morphological features in the chronic stage of Trypanosoma cruzi infection. Knowledge of these aspects is important to understand the other ways of transmission of the Chagas disease. Progressive motility, mass motility, concentration, and sperm morphology of 84 ejaculates of dogs that were chronically infected with T. cruzi were evaluated. Most of the findings were consistent with the reference values and with those obtained from healthy control dogs. The scrotal circumference was not correlated with spermatozoa concentration in the infected animals. In conclusion, the T. cruzi Ninoa (MHOM/MX/1994/Ninoa) strain does not cause significant alterations in the semen quality of dogs experiencing chronic Chagas disease (at concentrations of 5 × 104 to 1 × 106 parasites per animal). PMID:25114010

  3. Population differentiation of the Chagas disease vector Triatoma maculata (Erichson, 1848) from Colombia and Venezuela.

    Science.gov (United States)

    Monsalve, Yoman; Panzera, Francisco; Herrera, Leidi; Triana-Chávez, Omar; Gómez-Palacio, Andrés

    2016-06-01

    The emerging vector of Chagas disease, Triatoma maculata (Hemiptera, Reduviidae), is one of the most widely distributed Triatoma species in northern South America. Despite its increasing relevance as a vector, no consistent picture of the magnitude of genetic and phenetic diversity has yet been developed. Here, several populations of T. maculata from eleven Colombia and Venezuela localities were analyzed based on the morphometry of wings and the mitochondrial NADH dehydrogenase subunit 4 (ND4) gene sequences. Our results showed clear morphometric and genetic differences among Colombian and Venezuelan populations, indicating high intraspecific diversity. Inter-population divergence is suggested related to East Cordillera in Colombia. Analyses of other populations from Colombia, Venezuela, and Brazil from distinct eco-geographic regions are still needed to understand its systematics and phylogeography as well as its actual role as a vector of Chagas disease. © 2016 The Society for Vector Ecology.

  4. Community resilience and Chagas disease in a rural region of Mexico.

    Science.gov (United States)

    Rangel, José Antonio Santana; Monreal, Luz Arenas; Ramsey, Janine M

    2016-08-04

    To explore the pillars of community resilience in a region where Chagas disease is endemic, with the aim of promoting participatory processes to deal with this condition from the resilience of the population. Qualitative study using ethnographic record and six interviews of focus groups with young people, women and men. The research was carried out in a rural area of the state of Morelos, Mexico, between 2006 and 2007. We carried out educational sessions with the population in general, so that residents could identify the relationship between the vector Triatoma pallidipennis, the parasite (Trypanosoma cruzi), symptoms, and preventive actions for Chagas disease. The ethnographic record and groups were analyzed based on Taylor and Bogdan's modification, and the focus was to understand the socio-cultural meanings that guide the speeches and activities of residents in relation to the pillars of community resilience. The population felt proud of belonging to that location and three pillars of community resilience were clearly identified: collective self-esteem, cultural identity, and social honesty. Having these pillars as bases, we promoted the participation of the population concerning Chagas disease, and a Community Action Group was formed with young people, adult men and women, and social leaders. This Group initiated actions of epidemiological and entomological surveillance in the community to deal with this problem. It is necessary to create more experiences that deepen the understanding of the pillars of community resilience, and how they contribute to enhance participation in health to deal with Chagas disease. Explorar los pilares de la resiliencia comunitaria en una región en la que la enfermedad de Chagas es endémica, con la finalidad de partir de la resiliencia de la población para impulsar procesos participativos para enfrentar este padecimiento. Estudio cualitativo que utilizó registro etnográfico y seis entrevistas de grupos focales con j

  5. Prova do esforço na forma indeterminada da doença de Chagas

    Directory of Open Access Journals (Sweden)

    Vanize Macedo

    1973-10-01

    Full Text Available Os autores realizaram a prova do esforço sub-máximo em 30 portadores da forma indeterminada da doença de Chagas e em 30 normais, a fim de avaliar a capacidade física e a função miocárdica. Os resultados não mostraram diferenciação do grupo positivo e do controle negativo, quanto a queixas, freqüência cardíaca ou respiratória, tensão arterial, consumo de oxigênio e alterações eletrocardiográficas.To evaluate the physical capacity and the myoeardial function in 30 patientes with latent Chagas' disease, the effort test was performed. 30 Controls mere used. According to complains, cardiac and respiratory rate, maximum oxigen consumption and eletrocardiographic changes there was no difference between both groups.

  6. [Management of Chagas disease in Europe. Experiences and challenges in Spain, Switzerland and Italy].

    Science.gov (United States)

    Jackson, Y; Angheben, A; Carrilero Fernandez, B; Jansa i Lopez del Vallado, J M; Jannin, J G; Albajar-Viñas, P

    2009-12-01

    The intention of this article is not to describe the illness or evaluate the number of cases diagnosed in Spain, Switzerland and Italy, nor to analyse the protocols followed in various centres. The authors rather seek to examine the main technical, local and national challenges involved in the care of patients with Chagas disease. To this end, they review concisely a number of themes which are common to the three countries. These are: the detection of disease; confirmation of the diagnosis; treatment; response to treatment; follow-up; the risk of transmission by transfusion, by organ donation and from mother to child; the psychosocial and socio-economic aspects of Chagas disease outside endemic areas; and what progress needs to be made in improving information about the condition.

  7. [Carlos Chagas Filho: an articulator of the history of sciences in Brazil].

    Science.gov (United States)

    Domingues, Heloisa Maria Bertol

    2012-06-01

    A letter sent in 1982 by a group of scientists to the president of Conselho Nacional de Desenvolvimento Científico e Tecnológico appealed for a policy of preservation of Brazilian scientific culture. The name of Carlos Chagas Filho topped the list of signatures thereby proving his commitment to that proposal, the ideological structure of which was part of his experience in scientific policy in Brazil and abroad. This document harks back to the practice of the history of the sciences in Brazil and the creation of places for the safeguard and organization of scientific memory, such as the Museu de Astronomia e Ciências Afins, Casa de Oswaldo Cruz and the Sociedade Brasileira de História da Ciência, of which Carlos Chagas Filho was an inaugural member of the board of directors.

  8. The impact of Chagas disease control in Latin America: a review.

    Science.gov (United States)

    Dias, J C P; Silveira, A C; Schofield, C J

    2002-07-01

    Discovered in 1909, Chagas disease was progressively shown to be widespread throughout Latin America, affecting millions of rural people with a high impact on morbidity and mortality. With no vaccine or specific treatment available for large-scale public health interventions, the main control strategy relies on prevention of transmission, principally by eliminating the domestic insect vectors and control of transmission by blood transfusion. Vector control activities began in the 1940s, initially by means of housing improvement and then through insecticide spraying following successful field trials in Brazil (Bambui Research Centre), with similar results soon reproduced in São Paulo, Argentina, Venezuela and Chile. But national control programmes only began to be implemented after the 1970s, when technical questions were overcome and the scientific demonstration of the high social impact of Chagas disease was used to encourage political determination in favour of national campaigns (mainly in Brazil). Similarly, large-scale screening of infected blood donors in Latin America only began in the 1980s following the emergence of AIDS. By the end of the last century it became clear that continuous control in contiguous endemic areas could lead to the elimination of the most highly domestic vector populations - especially Triatoma infestans and Rhodnius prolixus - as well as substantial reductions of other widespread species such as T. brasiliensis, T. sordida, and T. dimidiata, leading in turn to interruption of disease transmission to rural people. The social impact of Chagas disease control can now be readily demonstrated by the disappearance of acute cases and of new infections in younger age groups, as well as progressive reductions of mortality and morbidity rates in controlled areas. In economic terms, the cost-benefit relationship between intervention (insecticide spraying, serology in blood banks) and the reduction of Chagas disease (in terms of medical and

  9. The impact of Chagas disease control in Latin America: a review

    Directory of Open Access Journals (Sweden)

    JCP Dias

    2002-07-01

    Full Text Available Discovered in 1909, Chagas disease was progressively shown to be widespread throughout Latin America, affecting millions of rural people with a high impact on morbidity and mortality. With no vaccine or specific treatment available for large-scale public health interventions, the main control strategy relies on prevention of transmission, principally by eliminating the domestic insect vectors and control of transmission by blood transfusion. Vector control activities began in the 1940s, initially by means of housing improvement and then through insecticide spraying following successful field trials in Brazil (Bambui Research Centre, with similar results soon reproduced in São Paulo, Argentina, Venezuela and Chile. But national control programmes only began to be implemented after the 1970s, when technical questions were overcome and the scientific demonstration of the high social impact of Chagas disease was used to encourage political determination in favour of national campaigns (mainly in Brazil. Similarly, large-scale screening of infected blood donors in Latin America only began in the 1980s following the emergence of AIDS. By the end of the last century it became clear that continuous control in contiguous endemic areas could lead to the elimination of the most highly domestic vector populations - especially Triatoma infestans and Rhodnius prolixus - as well as substantial reductions of other widespread species such as T. brasiliensis, T. sordida, and T. dimidiata, leading in turn to interruption of disease transmission to rural people. The social impact of Chagas disease control can now be readily demonstrated by the disappearance of acute cases and of new infections in younger age groups, as well as progressive reductions of mortality and morbidity rates in controlled areas. In economic terms, the cost-benefit relationship between intervention (insecticide spraying, serology in blood banks and the reduction of Chagas disease (in terms

  10. [Urbanization of Chagas disease in Peru: experiences in prevention and control].

    Science.gov (United States)

    Náquira, César

    2014-04-01

    In Peru, Chagas disease has an epidemiological significance in three macro-regions, one of them is the southern macro-region formed by the departments of Arequipa, Moquegua and Tacna. In 1965 a successful control was performed by house spraying insecticides, however, the persistence of the vector made it necessary for a second control plan that was implemented in 2000 and followed the guidelines of CONAL Plan, based on the elimination of Triatoma infestans and screening in blood banks.This plan was successful in Tacna and Moquegua, therefore these departments were considered free of vectorial transmission by the Pan American Health Organization. A ssimilar situation has not been achieved in the department of Arequipa because of the presence, among other factors, of rural migration to the city, in this way the urbanization of Chagas disease is a new epidemiological scenario of which we need to know more.

  11. PRISM, a Novel Visual Metaphor Measuring Personally Salient Appraisals, Attitudes and Decision-Making: Qualitative Evidence Synthesis.

    Directory of Open Access Journals (Sweden)

    Tom Sensky

    Full Text Available PRISM (the Pictorial Representation of Illness and Self Measure is a novel, simple visual instrument. Its utility was initially discovered serendipitously, but has been validated as a quantitative measure of suffering. Recently, new applications for different purposes, even in non-health settings, have encouraged further exploration of how PRISM works, and how it might be applied. This review will summarise the results to date from applications of PRISM and propose a generic conceptualisation of how PRISM works which is consistent with all these applications.A systematic review, in the form of a qualitative evidence synthesis, was carried out of all available published data on PRISM.Fifty-two publications were identified, with a total of 8254 participants. Facilitated by simple instructions, PRISM has been used with patient groups in a variety of settings and cultures. As a measure of suffering, PRISM has, with few exceptions, behaved as expected according to Eric Cassell's seminal conceptualisation of suffering. PRISM has also been used to assess beliefs about or attitudes to stressful working conditions, interpersonal relations, alcohol consumption, and suicide, amongst others.This review supports PRISM behaving as a visual metaphor of the relationship of objects (eg 'my illness' to a subject (eg 'myself' in a defined context (eg 'my life at the moment'. As a visual metaphor, it is quick to complete and yields personally salient information. PRISM is likely to have wide applications in assessing beliefs, attitudes, and decision-making, because of its properties, and because it yields both quantitative and qualitative data. In medicine, it can serve as a generic patient-reported outcome measure. It can serve as a tool for representational guidance, can be applied to developing strategies visually, and is likely to have applications in coaching, psychological assessment and therapeutic interventions.

  12. The Prevalence of Chagas Heart Disease in a Central Bolivian Community Endemic for Trypanosoma Cruzi

    Science.gov (United States)

    Yager, Jessica E.; Lozano Beltran, Daniel F.; Torrico, Faustino; Gilman, Robert H.; Bern, Caryn

    2015-01-01

    Background Though the incidence of new Trypanosoma cruzi infections has decreased significantly in endemic regions in the Americas, medical professionals continue to encounter a high burden of resulting Chagas disease among infected adults. The current prevalence of Chagas heart disease in a community setting is not known; nor is it known how recent insecticide vector control measures may have impacted the progression of cardiac disease in an infected population. Objectives and Methods Nested within a community serosurvey in rural and periurban communities in central Bolivia, we performed a cross-sectional cardiac substudy to evaluate adults for historical, clinical, and electrocardiographic evidence of cardiac disease. All adults between the ages of 20 and 60 years old with T. cruzi infection and those with a clinical history, physical exam, or ECG consistent with cardiac abnormalities were also scheduled for echocardiography. Results and conclusions Of the 604 cardiac substudy participants with definitive serology results, 183 were seropositive for infection with T. cruzi (30.3%). Participants who were seropositive for T. cruzi infection were more likely to have conduction system defects (1.6% versus 0 for complete right bundle branch block and 10.4% versus 1.9% for any bundle branch block; p=0.008 and p<0.001, respectively). However, there was no statistically significant difference in the prevalence of bradycardia among seropositive versus seronegative participants. Echocardiogram findings were not consistent with a high burden of Chagas cardiomyopathy: valvulopathies were the most common abnormality, and few participants were found to have low ejection fraction or left ventricular dilatation. No participants had significant heart failure. Though almost one third of adults in the community were seropositive for T. cruzi infection, few had evidence of Chagas heart disease. PMID:26407509

  13. A scientometric evaluation of the Chagas disease implementation research programme of the PAHO and TDR.

    Directory of Open Access Journals (Sweden)

    Ana Laura Carbajal-de-la-Fuente

    2013-11-01

    Full Text Available The Special Programme for Research and Training in Tropical Diseases (TDR is an independent global programme of scientific collaboration cosponsored by the United Nations Children's Fund, the United Nations Development Program, the World Bank, and the World Health Organization. TDR's strategy is based on stewardship for research on infectious diseases of poverty, empowerment of endemic countries, research on neglected priority needs, and the promotion of scientific collaboration influencing global efforts to combat major tropical diseases. In 2001, in view of the achievements obtained in the reduction of transmission of Chagas disease through the Southern Cone Initiative and the improvement in Chagas disease control activities in some countries of the Andean and the Central American Initiatives, TDR transferred the Chagas Disease Implementation Research Programme (CIRP to the Communicable Diseases Unit of the Pan American Health Organization (CD/PAHO. This paper presents a scientometric evaluation of the 73 projects from 18 Latin American and European countries that were granted by CIRP/PAHO/TDR between 1997 and 2007. We analyzed all final reports of the funded projects and scientific publications, technical reports, and human resource training activities derived from them. Results about the number of projects funded, countries and institutions involved, gender analysis, number of published papers in indexed scientific journals, main topics funded, patents inscribed, and triatomine species studied are presented and discussed. The results indicate that CIRP/PAHO/TDR initiative has contributed significantly, over the 1997-2007 period, to Chagas disease knowledge as well as to the individual and institutional-building capacity.

  14. La enfermedad de Chagas ya no es tan exótica

    Centers for Disease Control (CDC) Podcasts

    2008-04-03

    Este podcast tiene el propósito de informar a los profesionales de la salud sobre la enfermedad de Chagas, su diagnóstico y tratamiento, así como orientar en la identificación de pacientes infectados.  Created: 4/3/2008 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 4/9/2008.

  15. La migrazione del chagas: Costruzione bio-medica e socio-politica delle malattie tropicali dimenticate

    OpenAIRE

    Ciannameo, Anna

    2014-01-01

    Questo studio propone un'esplorazione dei nessi tra processi migratori ed esperienze di salute e malattia a partire da un'indagine sulle migrazioni provenienti dall'America latina in Emilia-Romagna. Contemporaneamente indaga i termini del dibattito sulla diffusione della Malattia di Chagas, “infezione tropicale dimenticata” endemica in America centro-meridionale che, grazie all'incremento dei flussi migratori transnazionali, viene oggi riconfigurata come 'emergente' in alcuni contesti di imm...

  16. Population structure of the Chagas disease vector, Triatoma infestans, at the urban-rural interface

    OpenAIRE

    Foley, Erica A.; Khatchikian, Camilo E.; Hwang, Josephine; Ancca-Juárez, Jenny; Borrini-Mayori, Katty; Quıspe-Machaca, Victor R.; Levy, Michael Z.; Brisson, Dustin

    2013-01-01

    The increasing rate of biological invasions resulting from human transport or human-mediated changes to the environment have had devastating ecologic and public health consequences. The kissing bug, Triatoma infestans, has dispersed through the Peruvian city of Arequipa. The biological invasion of this insect has resulted in a public health crisis, putting thousands of residents of this city at risk of infection by Trypanosoma cruzi and subsequent development of Chagas disease. Here we show t...

  17. Human Chagas Disease and Migration in the Context of Globalization: Some Particular Aspects

    Directory of Open Access Journals (Sweden)

    João Carlos Pinto Dias

    2013-01-01

    Full Text Available Human Chagas disease originated in Latin America, being spread around the world in relation with multiple bioecological, sociocultural, and political factors. The process of the disease production and dispersion is discussed, emphasizing the human migration and correlated aspects, in the context of globalization. Positive and negative consequences concern the future of this trypanosomiasis, mainly in terms of the ecologic and sociopolitical characteristics of the endemic and nonendemic countries.

  18. High Resolution Esophageal Manometry in Patients with Chagas Disease: A Cross-Sectional Evaluation.

    Directory of Open Access Journals (Sweden)

    Adrián Sánchez-Montalvá

    2016-02-01

    Full Text Available Gastrointestinal involvement affects 30-40% of the patients with chronic Chagas disease. Esophageal symptoms appear once the structural damage is established. Little is known about the usefulness of high resolution manometry to early identification of esophageal involvement.We performed a cross-sectional study at the Vall d'Hebron University Hospital (Barcelona, Spain between May 2011 and April 2012. Consecutive patients diagnosed with Chagas disease in the chronic phase were offered to participate. All patients underwent a structured questionnaire about digestive symptoms, a barium esophagogram (Rezende classification and an esophageal high resolution manometry (HRM. A control group of patients with heartburn who underwent an esophageal HRM in our hospital was selected.62 out of 73 patients that were included in the study fulfilled the study protocol. The median age of the Chagas disease group (CG was 37 (IQR 32-45 years, and 42 (67.7% patients were female. Twenty-seven (43.5% patients had esophageal symptoms, heartburn being the most frequent. Esophagogram was abnormal in 5 (8.77%. The esophageal HRM in the CG showed a pathological motility pattern in 14 patients (22.6%. All of them had minor disorders of the peristalsis (13 with ineffective esophageal motility and 1 with fragmented peristalsis. Hypotonic lower esophageal sphincter was found more frequently in the CG than in the control group (21% vs 3.3%; p<0.01. Upper esophageal sphincter was hypertonic in 22 (35.5% and hypotonic in 1 patient. When comparing specific manometric parameters or patterns in the CG according to the presence of symptoms or esophagogram no statistically significant association were seen, except for distal latency.The esophageal involvement measured by HRM in patients with chronic Chagas disease in our cohort is 22.6%. All the patients with esophageal alterations had minor disorders of the peristalsis. Symptoms and esophagogram results did not correlate with the HRM

  19. Follow-up Evaluation of Air Force Blood Donors Screening Positive for Chagas Disease

    Science.gov (United States)

    2017-08-27

    Blood Donors Screening Positive for Cbagas Disease presented at/published to Military Health System Research Symposium (Florida, 27-30 Aug 2017) in...disease upon blood donation at JBSA -Lackland 6. TITLE OF MATERIAL TO BE PUBLISHED OR PRESENTED: Follow-up evaluation of Air Force blood donors ...Designated Exempt Reviewer Follow-up evaluation of Air Force blood donors screening positive for Chagas disease Joseph Marcus1, Bryant Webber2, Leo Cropper2

  20. Evaluation of oral mucosal transudate for immunodiagnosis of Chagas´ disease

    Directory of Open Access Journals (Sweden)

    BARROS Maria das Neves D. S.

    1999-01-01

    Full Text Available Anticorpos anti-Trypanosoma cruzi (isotipo IgG foram detectados no transudato da mucosa oral (TMO através de um ensaio imunoenzimático. Foram estudados 21 indivíduos com doença de Chagas crônica comprovada através de diagnóstico clínico, eletrocardiográfico, epidemiológico e sorológico: 10 com forma cardíaca, 2 com forma digestiva, 6 com forma mista e 3 com forma assintomática. Sete indivíduos de área endêmica, com sorologia negativa, constituiram o grupo controle. O soro destes grupos foi armazenado a -20 oC. A coleta de TMO de ambos os grupos foi realizada com o dispositivo OraSureâ seguindo orientação do fabricante (OraSureâ , Epitope Inc., Beaverton, OR, USA. As amostras de TMO foram diluídas (1:2 e testadas em duplicata através de um ensaio imunoenzimático da Abbott Laboratories para detectar anticorpos IgG contra doença de Chagas. Vinte dos vinte e um pacientes chagásicos apresentaram densidade óptica acima do limiar de reatividade e foram considerados positivos para doença de Chagas. Nenhuma das amostras provenientes de indivíduos soronegativos foi positiva. A sensibilidade e especificidade foram de 95% e 100%, respectivamente. Estes resultados indicam que TMO poderá ser utilizado como um fluido biológico alternativo para o diagnóstico da doença de Chagas. Nós estamos aumentando o número de indivíduos para validar estes resultados incluindo a análise comparativa entre amostras de TMO e soro.

  1. [Possible oral transmission of Chagas disease among hydrocarbons sector workers in Casanare, Colombia, 2014].

    Science.gov (United States)

    Zuleta-Dueñas, Liliana Patricia; López-Quiroga, Ángela Johana; Torres-Torres, Fernando; Castañeda-Porras, Oneida

    2017-06-01

    Trypanosoma cruzi, the etiological agent for Chagas disease, can be transmitted by oral intake of contaminated food or drinks. During epidemiological week 14 of 2014, two cases of acute Chagas disease were notified among hydrocarbons sector workers in Paz de Ariporo, Casanare. To characterize the affected population, to establish control and prevention measures and to confirm the outbreak. We conducted an outbreak investigation that included the following components: a) Search for symptomatic people compatible with Chagas disease according to the case definition for their referral to medical services; b) entomological survey (192/197 houses); c) sanitary inspection and microbiological analysis of food samples; and d) study of reservoirs. Data management and analysis were done with Epi-Info 7.1.5 using descriptive statistics. We also calculated intradomicile and peridomicile triatomine infestation indexes. We detected 552 exposed people; 40 had the disease (7.2%), of whom seven were women (17,5%) and 33, men (82.5%), i.e., a male-female ratio of 5:1. The mean age was 39.1 ± 10.8 years; the attack rate was 7.2% and lethality, 5% (2/40). Symptoms included fever (100% of cases), headache (80%), myalgia and arthralgia (65%), facial edema (55%), and abdominal pain (37.5%). The mean incubation time was 17 days (range: 3-21). Rhodnius prolixus domiciliary infestation index was 3.3 % and 2.2% in the peridomicile. In the five restaurants inspected sanitary conditions were deficient and food samples were microbiologically non-conforming. We found a dog and two opossums positive for IgG antibodies by ELISA. Environmental, sanitary and epidemiological conditions at the place confirmed an outbreak of Chagas diseases related to occupational exposure, possibly by oral transmission, which may be the largest to date in Colombia.

  2. Community resilience and Chagas disease in a rural region of Mexico

    Directory of Open Access Journals (Sweden)

    José Antonio Santana Rangel

    2016-01-01

    Full Text Available ABSTRACT OBJECTIVE To explore the pillars of community resilience in a region where Chagas disease is endemic, with the aim of promoting participatory processes to deal with this condition from the resilience of the population. METHODS Qualitative study using ethnographic record and six interviews of focus groups with young people, women and men. The research was carried out in a rural area of the state of Morelos, Mexico, between 2006 and 2007. We carried out educational sessions with the population in general, so that residents could identify the relationship between the vector Triatoma pallidipennis, the parasite (Trypanosoma cruzi, symptoms, and preventive actions for Chagas disease. The ethnographic record and groups were analyzed based on Taylor and Bogdan’s modification, and the focus was to understand the socio-cultural meanings that guide the speeches and activities of residents in relation to the pillars of community resilience. RESULTS The population felt proud of belonging to that location and three pillars of community resilience were clearly identified: collective self-esteem, cultural identity, and social honesty. Having these pillars as bases, we promoted the participation of the population concerning Chagas disease, and a Community Action Group was formed with young people, adult men and women, and social leaders. This Group initiated actions of epidemiological and entomological surveillance in the community to deal with this problem. CONCLUSIONS It is necessary to create more experiences that deepen the understanding of the pillars of community resilience, and how they contribute to enhance participation in health to deal with Chagas disease.

  3. Le Honduras se démarque dans la lutte contre la maladie de Chagas

    International Development Research Centre (IDRC) Digital Library (Canada)

    25 janv. 2011 ... ... en partenariat avec la fondation nationale du logement, ont grandement contribué à la lutte contre la transmission de la maladie de Chagas. À ce jour, 45 % des habitants du comté vivent dans de nouvelles maisons faites de matériaux − murs d'adobe, planchers de ciment, toits de zinc − qui n'attirent pas ...

  4. COMET and PRISM - Search for Charged Lepton Flavor Violation with Muons

    Energy Technology Data Exchange (ETDEWEB)

    Kuno, Yoshitaka [Department of Physics, Osaka University, Osaka, 560-0043 (Japan)

    2012-04-15

    The experiment (COMET) at J-PARC to search for a charged-lepton-flavor-violating process of muon to electron conversion in a muonic atom is described. Future prospects of an experiment (PRISM) with even higher sensitivity is mentioned. On-going R and D on a highly intense muon source (MuSIC) at Osaka University is presented.

  5. Economic assessment of S-prism including development and generating costs

    Energy Technology Data Exchange (ETDEWEB)

    Boardman, Ch.E. [GE Nuclear Energy San Jose (United States)

    2001-07-01

    S-PRISM is an advanced Fast Reactor plant design that utilizes compact modular pool-type reactors sized to enable factory fabrication and an affordable prototype test of a single Nuclear Steam Supply System (NSSS) for design certification at minimum cost and risk. S-PRISM retains all of the key ALMR (advanced liquid metal reactor) design features including passive reactor shutdown, passive shutdown heat removal, and passive reactor cavity cooling that were developed under an earlier DOE program. Key factors that make S-PRISM competitive include: 1) The use of passive safety systems that eliminate the need for diesel generators and hardened active heat sinks to assure that sufficient heat is removed from the core, reactor, and containment systems following design and beyond design basis events. 2) A seven point advantage in the plant capacity factor (93 versus 86%) over a single large plant. 3) A much shorter construction schedule (45%) made possible by a modular design that allows near parallel (sequenced) construction of three relatively small, simple factory fabricated NSSSs instead of one large complex NSSS. This paper describes the approach, methods, and results of an in-depth economic assessment of S-PRISM. The assessment found that the generation cost from an NOAK plant would be less than 3 cents/kW-hr and that a design certification could be obtained in less than 15 years at a cost of 2.1 billion dollars. (authors)

  6. Establishment and correction of an Echelle cross-prism spectrogram reduction model

    Science.gov (United States)

    Zhang, Rui; Bayanheshig; Li, Xiaotian; Cui, Jicheng

    2017-11-01

    The accuracy of an echelle cross-prism spectrometer depends on the matching degree between the spectrum reduction model and the actual state of the spectrometer. However, the error of adjustment can change the actual state of the spectrometer and result in a reduction model that does not match. This produces an inaccurate wavelength calibration. Therefore, the calibration of a spectrogram reduction model is important for the analysis of any echelle cross-prism spectrometer. In this study, the spectrogram reduction model of an echelle cross-prism spectrometer was established. The image position laws of a spectrometer that varies with the system parameters were simulated to the influence of the changes in prism refractive index, focal length and so on, on the calculation results. The model was divided into different wavebands. The iterative method, least squares principle and element lamps with known characteristic wavelength were used to calibrate the spectral model in different wavebands to obtain the actual values of the system parameters. After correction, the deviation of actual x- and y-coordinates and the coordinates calculated by the model are less than one pixel. The model corrected by this method thus reflects the system parameters in the current spectrometer state and can assist in accurate wavelength extraction. The instrument installation and adjustment would be guided in model-repeated correction, reducing difficulty of equipment, respectively.

  7. COMET and PRISM - Search for Charged Lepton Flavor Violation with Muons

    International Nuclear Information System (INIS)

    Kuno, Yoshitaka

    2012-01-01

    The experiment (COMET) at J-PARC to search for a charged-lepton-flavor-violating process of muon to electron conversion in a muonic atom is described. Future prospects of an experiment (PRISM) with even higher sensitivity is mentioned. On-going R and D on a highly intense muon source (MuSIC) at Osaka University is presented.

  8. The Behaviour of Palm Oil Fibre Block Masonry Prism under Eccentric Compressive Loading

    Science.gov (United States)

    Mokhtar, Mardiha; Kolop, Roslan; Baizura Hamid, Nor; Kaamin, Masiri; Farhan Rosdi, Mohd; Ngadiman, Norhayati; Sahat, Suhaila

    2017-08-01

    Dry-stacked masonry offers great benefits in constructing masonry buildings. Several examples from previous research show that dry masonry is reasonable alternative to the traditional building system. By addition of fibre, the ductility and the propagation of cracking will be improved. This study investigates the dry stack oil palm fibre block prisms which were subjected to eccentricity compression loads. These concrete blocks were cast using a single mould with suitable fibre-cement composition namely 1:4 (cement: sand) and 0.40 water to the cement ratio based on cement weight. Prisms test using 400 (length) × 150 (width) × 510 (height) mm specimen was carried under eccentric load. There were forty eight (48) prisms built with different configurations based on their volume of fibre. In this study, one types of grout were used namely the fine grout of mix 1:3:2 (cement: sand: aggregate (5mm maximum). Based on the test performed, the failure mechanism and influencing parameters were discussed. From compressive strength test result, it shows that the strength of concrete block decreased with the increase of fibre used. Although the control sample has the higher strength compared to concrete with EFB, it can be seen from mode failure of masonry prism that fibre could extend the cracking time. These results show that the oil palm fibre blocks can improve the failure behaviour and suitable to be used as load bearing wall construction in Malaysia.

  9. Direct AFM observation of an opening event of a DNA cuboid constructed via a prism structure.

    Science.gov (United States)

    Endo, Masayuki; Hidaka, Kumi; Sugiyama, Hiroshi

    2011-04-07

    A cuboid structure was constructed using a DNA origami design based on a square prism structure. The structure was characterized by atomic force microscopy (AFM) and dynamic light scattering. The real-time opening event of the cuboid was directly observed by high-speed AFM.

  10. Economic assessment of S-prism including development and generating costs

    International Nuclear Information System (INIS)

    Boardman, Ch.E.

    2001-01-01

    S-PRISM is an advanced Fast Reactor plant design that utilizes compact modular pool-type reactors sized to enable factory fabrication and an affordable prototype test of a single Nuclear Steam Supply System (NSSS) for design certification at minimum cost and risk. S-PRISM retains all of the key ALMR (advanced liquid metal reactor) design features including passive reactor shutdown, passive shutdown heat removal, and passive reactor cavity cooling that were developed under an earlier DOE program. Key factors that make S-PRISM competitive include: 1) The use of passive safety systems that eliminate the need for diesel generators and hardened active heat sinks to assure that sufficient heat is removed from the core, reactor, and containment systems following design and beyond design basis events. 2) A seven point advantage in the plant capacity factor (93 versus 86%) over a single large plant. 3) A much shorter construction schedule (45%) made possible by a modular design that allows near parallel (sequenced) construction of three relatively small, simple factory fabricated NSSSs instead of one large complex NSSS. This paper describes the approach, methods, and results of an in-depth economic assessment of S-PRISM. The assessment found that the generation cost from an NOAK plant would be less than 3 cents/kW-hr and that a design certification could be obtained in less than 15 years at a cost of 2.1 billion dollars. (authors)

  11. Analysis of unscrammed loss of flow and heat sink for PRISM with GEM

    International Nuclear Information System (INIS)

    Slovik, G.C.; Van Tuyle, G.J.; Kennett, R.J.

    1991-01-01

    The US Department of Energy is sponsoring an advanced liquid-metal reactor design by General Electric Company (GE) called PRISM. The intent is to design a reactor with passively safe responses to many operational and severe accidents. PRISM is under review at the US Nuclear Regulatory Commission for licensability with Brookhaven National Laboratory providing technical assistance. Recently, the PRISM design has been modified to include three gas expansion modules (GEMs) on its core periphery. The GEMs were added to quickly reduce the power (by inserting negative reactivity) during loss-of-flow events to curtail peak fuel and clad temperatures predicted in the previous design. The GEM prototypes have been tested at the Fast Flux Test Facility. The significance of the GEMs in PRISM is discussed in this paper through the evaluation of the unprotected loss of flow (ULOF) and loss of heat sink using the SSC code. It has been demonstrated in the past that SSC predicts results similar to GE and other liquid-metal reactor codes

  12. Numerical simulation of blast wave propagation in vicinity of standalone prism on flat plate

    Science.gov (United States)

    Valger, Svetlana; Fedorova, Natalya; Fedorov, Alexander

    2018-03-01

    In the paper, numerical simulation of shock wave propagation in the vicinity of a standalone prism and a prism with a cavity in front of it was carried out. The modeling was based on the solution of 3D Euler equations and Fluent software was used as a main computational tool. The algorithm for local dynamic mesh adaptation to high gradients of pressure was applied. The initial stage of the explosion of condensed explosive was described with the help of "Compressed balloon method". The research allowed describing the characteristic stages of the blast in a semi-closed space, the structure of secondary shock waves and their interaction with obstacles. The numerical approach in Fluent based on combining inviscid gas dynamics methods and "Compressed balloon method" was compared with the method which had been used by the authors earlier with the help of AUTODYN and which is based on the use of the hydrodynamic model of a material to describe state of detonation products. For the problem of shock wave propagation in the vicinity of standalone prism the comparison of the simulation results obtained using both the methods with the experimental data was performed on the dependence of static pressure and effective momentum on time for the characteristic points located on prism walls.

  13. A compact and lightweight off-axis lightguide prism in near to eye display

    Science.gov (United States)

    Zhuang, Zhenfeng; Cheng, Qijia; Surman, Phil; Zheng, Yuanjin; Sun, Xiao Wei

    2017-06-01

    We propose a method to improve the design of an off-axis lightguide configuration for near to eye displays (NED) using freeform optics technology. The advantage of this modified optical system, which includes an organic light-emitting diode (OLED), a doublet lens, an imaging lightguide prism and a compensation prism, is that it increases optical length path, offers a smaller size, as well as avoids the obstructed views, and matches the user's head shape. In this system, the light emitted from the OLED passes through the doublet lens and is refracted/reflected by the imaging lightguide prism, which is used to magnify the image from the microdisplay, while the compensation prism is utilized to correct the light ray shift so that a low-distortion image can be observed in a real-world setting. A NED with a 4 mm diameter exit pupil, 21.5° diagonal full field of view (FoV), 23 mm eye relief, and a size of 33 mm by 9.3 mm by 16 mm is designed. The developed system is compact, lightweight and suitable for entertainment and education application.

  14. Nonlinear attractor dynamics in the fundamental and extended prism adaptation paradigm

    International Nuclear Information System (INIS)

    Frank, T.D.; Blau, Julia J.C.; Turvey, M.T.

    2009-01-01

    Adaptation and re-adaptation processes are studied in terms of dynamic attractors that evolve and devolve. In doing so, a theoretical account is given for the fundamental observation that adaptation and re-adaptation processes do not exhibit one-trial learning. Moreover, the emergence of the latent aftereffect in the extended prism paradigm is addressed

  15. Development and application of GIS-based PRISM integration through a plugin approach

    Science.gov (United States)

    Lee, Woo-Seop; Chun, Jong Ahn; Kang, Kwangmin

    2014-05-01

    A PRISM (Parameter-elevation Regressions on Independent Slopes Model) QGIS-plugin was developed on Quantum GIS platform in this study. This Quantum GIS plugin system provides user-friendly graphic user interfaces (GUIs) so that users can obtain gridded meteorological data of high resolutions (1 km × 1 km). Also, this software is designed to run on a personal computer so that it does not require an internet access or a sophisticated computer system. This module is a user-friendly system that a user can generate PRISM data with ease. The proposed PRISM QGIS-plugin is a hybrid statistical-geographic model system that uses coarse resolution datasets (APHRODITE datasets in this study) with digital elevation data to generate the fine-resolution gridded precipitation. To validate the performance of the software, Prek Thnot River Basin in Kandal, Cambodia is selected for application. Overall statistical analysis shows promising outputs generated by the proposed plugin. Error measures such as RMSE (Root Mean Square Error) and MAPE (Mean Absolute Percentage Error) were used to evaluate the performance of the developed PRISM QGIS-plugin. Evaluation results using RMSE and MAPE were 2.76 mm and 4.2%, respectively. This study suggested that the plugin can be used to generate high resolution precipitation datasets for hydrological and climatological studies at a watershed where observed weather datasets are limited.

  16. Corporate Privacy Policy Changes during PRISM and the Rise of Surveillance Capitalism

    Directory of Open Access Journals (Sweden)

    Priya Kumar

    2017-03-01

    Full Text Available Disclosure of the NSA’s PRISM program demonstrated that Internet companies have become prime targets of government surveillance. But what role do companies themselves play in putting users’ privacy at risk? By comparing the changes in the privacy policies of ten companies—the nine in PRISM plus Twitter—I seek to understand how users’ privacy shifted. Specifically, I study how company practices surrounding the life cycle of user information (e.g. collection, use, sharing, and retention shifted between the times when companies joined PRISM and when PRISM news broke. A qualitative analysis of the changes in the privacy policies suggests that company disclosure of tracking for advertising purposes increased. I draw on business scholar Shoshana Zuboff’s conceptualization of “surveillance capitalism” and legal scholar Joel Reidenberg’s “transparent citizen” to explain the implications such changes hold for users’ privacy. These findings underscore why public debates about post-Snowden privacy rights cannot ignore the role that companies play in legitimizing surveillance activities under the auspices of creating market value.

  17. Propagation of rotational Risley-prism-array-based Gaussian beams in turbulent atmosphere

    Science.gov (United States)

    Chen, Feng; Ma, Haotong; Dong, Li; Ren, Ge; Qi, Bo; Tan, Yufeng

    2018-03-01

    Limited by the size and weight of prism and optical assembling, Rotational Risley-prism-array system is a simple but effective way to realize high power and superior beam quality of deflecting laser output. In this paper, the propagation of the rotational Risley-prism-array-based Gaussian beam array in atmospheric turbulence is studied in detail. An analytical expression for the average intensity distribution at the receiving plane is derived based on nonparaxial ray tracing method and extended Huygens-Fresnel principle. Power in the diffraction-limited bucket is chosen to evaluate beam quality. The effect of deviation angle, propagation distance and intensity of turbulence on beam quality is studied in detail by quantitative simulation. It reveals that with the propagation distance increasing, the intensity distribution gradually evolves from multiple-petal-like shape into the pattern that contains one main-lobe in the center with multiple side-lobes in weak turbulence. The beam quality of rotational Risley-prism-array-based Gaussian beam array with lower deviation angle is better than its counterpart with higher deviation angle when propagating in weak and medium turbulent (i.e. Cn2 beam quality of higher deviation angle arrays degrades faster as the intensity of turbulence gets stronger. In the case of propagating in strong turbulence, the long propagation distance (i.e. z > 10km ) and deviation angle have no influence on beam quality.

  18. Family Perspectives: Using a Cultural Prism to Understand Families from Asian Cultural Backgrounds

    Science.gov (United States)

    Lee, Suk-Hyang; Turnbull, Ann P.; Zan, Fei

    2009-01-01

    Educators can better serve students who come from diverse cultural backgrounds by understanding the differing cultural values of these students and their families. This article explores different cultural perspectives using a cultural prism approach, focused most specifically on the Korean and Chinese cultures. (Contains 2 tables.)

  19. PRISM (Polarized Radiation Imaging and Spectroscopy Mission): an extended white paper

    NARCIS (Netherlands)

    André, Philippe; Baccigalupi, Carlo; Banday, Anthony; Barbosa, Domingos; Barreiro, Belen; Bartlett, James; Bartolo, Nicola; Battistelli, Elia; Battye, Richard; Bendo, George; Benoît, Alain; Bernard, Jean-Philippe; Bersanelli, Marco; Béthermin, Matthieu; Bielewicz, Pawel; Bonaldi, Anna; Bouchet, François; Boulanger, François; Brand, Jan; Bucher, Martin; Burigana, Carlo; Cai, Zhen-Yi; Camus, Philippe; Casas, Francisco; Casasola, Viviana; Castex, Guillaume; Challinor, Anthony; Chluba, Jens; Chon, Gayoung; Colafrancesco, Sergio; Comis, Barbara; Cuttaia, Francesco; D'Alessandro, Giuseppe; Da Silva, Antonio; Davis, Richard; de Avillez, Miguel; de Bernardis, Paolo; de Petris, Marco; de Rosa, Adriano; de Zotti, Gianfranco; Delabrouille, Jacques; Désert, François-Xavier; Dickinson, Clive; Diego, Jose Maria; Dunkley, Joanna; Enßlin, Torsten; Errard, Josquin; Falgarone, Edith; Ferreira, Pedro; Ferrière, Katia; Finelli, Fabio; Fletcher, Andrew; Fosalba, Pablo; Fuller, Gary; Galli, Silvia; Ganga, Ken; García-Bellido, Juan; Ghribi, Adnan; Giard, Martin; Giraud-Héraud, Yannick; Gonzalez-Nuevo, Joaquin; Grainge, Keith; Gruppuso, Alessandro; Hall, Alex; Hamilton, Jean-Christophe; Haverkorn, Marijke; Hernandez-Monteagudo, Carlos; Herranz, Diego; Jackson, Mark; Jaffe, Andrew; Khatri, Rishi; Kunz, Martin; Lamagna, Luca; Lattanzi, Massimiliano; Leahy, Paddy; Lesgourgues, Julien; Liguori, Michele; Liuzzo, Elisabetta; Lopez-Caniego, Marcos; Macias-Perez, Juan; Maffei, Bruno; Maino, Davide; Mangilli, Anna; Martinez-Gonzalez, Enrique; Martins, Carlos J. A. P.; Masi, Silvia; Massardi, Marcella; Matarrese, Sabino; Melchiorri, Alessandro; Melin, Jean-Baptiste; Mennella, Aniello; Mignano, Arturo; Miville-Deschênes, Marc-Antoine; Monfardini, Alessandro; Murphy, Anthony; Naselsky, Pavel; Nati, Federico; Natoli, Paolo; Negrello, Mattia; Noviello, Fabio; O'Sullivan, Créidhe; Paci, Francesco; Pagano, Luca; Paladino, Rosita; Palanque-Delabrouille, Nathalie; Paoletti, Daniela; Peiris, Hiranya; Perrotta, Francesca; Piacentini, Francesco; Piat, Michel; Piccirillo, Lucio; Pisano, Giampaolo; Polenta, Gianluca; Pollo, Agnieszka; Ponthieu, Nicolas; Remazeilles, Mathieu; Ricciardi, Sara; Roman, Matthieu; Rosset, Cyrille; Rubino-Martin, Jose-Alberto; Salatino, Maria; Schillaci, Alessandro; Shellard, Paul; Silk, Joseph; Starobinsky, Alexei; Stompor, Radek; Sunyaev, Rashid; Tartari, Andrea; Terenzi, Luca; Toffolatti, Luigi; Tomasi, Maurizio; Trappe, Neil; Tristram, Matthieu; Trombetti, Tiziana; Tucci, Marco; Van de Weijgaert, Rien; Van Tent, Bartjan; Verde, Licia; Vielva, Patricio; Wandelt, Ben; Watson, Robert; Withington, Stafford

    2014-01-01

    PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013 as a large-class mission for investigating within the framework of the ESA Cosmic Vision program a set of important scientific questions that require high resolution, high sensitivity, full-sky observations

  20. Novel laterally pumped by prism laser configuration for compact solid-state lasers

    International Nuclear Information System (INIS)

    Dascalu, T; Salamu, G; Sandu, O; Voicu, F; Pavel, N

    2013-01-01

    We propose a new laser configuration in which the pump radiation is coupled into the laser crystal through a prism. The laser medium is square shaped and the prism is attached on one of its lateral sides, near one of the crystal extremities. The diode-laser fiber end is placed close to the prism hypotenuse, the pump radiation is coupled into the laser crystal through the opposite surface of the prism and propagates into the crystal through total internal reflections. This laser geometry is simple to align and permits the realization of compact diode-pumped laser systems, as well as power scaling. A diode-pumped Nd:YAG laser yielding pulses of 2.1 mJ energy under a pump with pulses of 9.9 mJ is demonstrated. The laser slope efficiency is 0.22. Furthermore, this geometry enables one to obtain passively Q-switched lasers with the saturable absorber crystal placed between the resonator high-reflectivity mirror and the laser crystal. A Nd:YAG laser, passively Q-switched by a Cr 4+ :YAG crystal with initial transmission T 0 = 0.90, delivering laser output with a pulsed energy of 93 μJ, a duration of 26 ns and a pump threshold of 1.9 mJ, is realized in order to prove the concept. (letter)

  1. [Knowledge of vector-borne diseases (dengue, rickettsiosis and Chagas disease) in physicians].

    Science.gov (United States)

    Lugo-Caballero, César I; Dzul-Rosado, Karla; Dzul-Tut, Irving; Balam-May, Ángel; Zavala-Castro, Jorge

    2017-01-01

    The ecological conditions of Yucatan made it a suitable region for the acquisition of vector-borne diseases such as dengue, rickettsiosis, and Chagas disease. As the epidemiological burden of these diseases shows an alarming increase of severe cases, the early establishment of diagnosis and therapeutics by first-contact physicians is a critical step that is not being fulfilled due to several reasons, including poor knowledge. To determine the level of knowledge related to dengue, Chagas disease, and rickettsiosis among rural first-contact physicians of Yucatan. A survey was applied to 90 first-contact physicians from rural clinics of Yucatan, which included 32 items related to the diagnosis, treatment, and prevention of dengue, rickettsiosis, and Chagas disease. Answers were analyzed by central tendency statistics. Differences were observed among every category, however; diagnosis and therapeutics showed the lower values. Globally, 62.5% of respondents showed moderate knowledge, 37.5% poor knowledge, and 0% adequate knowledge. Results suggest that a strong campaign for a continuous diffusion of knowledge regarding these diseases is needed. In regions with high prevalence of these kinds of diseases, like Yucatan, the impact of these results on the epidemiological burden of these diseases must be evaluated.

  2. Current and developing therapeutic agents in the treatment of Chagas disease

    Directory of Open Access Journals (Sweden)

    Werner Apt

    2010-09-01

    Full Text Available Werner AptUniversity of Chile, Faculty of Medicine, Santiago, ChileAbstract: Chagas disease must be treated in all its stages: acute, indeterminate, chronic, and initial and middle determinant chronic, due to the fact that DNA of the parasite can be demonstrated by PCR in chronic cases, where optical microscopy does not detect parasites. Nifurtimox (NF and benznidazole (BNZ are the drugs accepted to treat humans based upon ethical considerations and efficiency. However, both the drugs produce secondary effects in 30% of the cases, and the treatment must be given for at least 30–60 days. Other useful drugs are itraconazole and posaconazole. The latter may be the drug to treat Chagas disease in the future when all the investigations related to it are finished. At present, there is no criterion of cure for chronic cases since in the majority, the serology remains positive, although it may decrease. In acute cases, 70% cure with NF and 75% with BNZ is achieved. In congenital cases, 100% cure is obtained if the treatment is performed during the first year of life. In chronic acquired cases, 20% cure and 50% improvement of the electrocardiographic changes are obtained with itraconazole.Keywords: Chagas disease, treatment, nifurtimox, benznidazole, allopurinol, itraconazole, posaconazole

  3. Access to benznidazole for Chagas disease in the United States-Cautious optimism?

    Directory of Open Access Journals (Sweden)

    Jonathan D Alpern

    2017-09-01

    Full Text Available Drugs for neglected tropical diseases (NTD are being excessively priced in the United States. Benznidazole, the first-line drug for Chagas disease, may become approved by the Food and Drug Administration (FDA and manufactured by a private company in the US, thus placing it at risk of similar pricing. Chagas disease is an NTD caused by Trypanosoma cruzi; it is endemic to Latin America, infecting 8 million individuals. Human migration has changed the epidemiology causing nonendemic countries to face increased challenges in diagnosing and managing patients with Chagas disease. Only 2 drugs exist with proven efficacy: benznidazole and nifurtimox. Benznidazole has historically faced supply problems and drug shortages, limiting accessibility. In the US, it is currently only available under an investigational new drug (IND protocol from the CDC and is provided free of charge to patients. However, 2 companies have stated that they intend to submit a New Drug Application (NDA for FDA approval. Based on recent history of companies acquiring licensing rights for NTD drugs in the US with limited availability, it is likely that benznidazole will become excessively priced by the manufacturer-paradoxically making it less accessible. However, if the companies can be taken at their word, there may be reason for optimism.

  4. Access to benznidazole for Chagas disease in the United States-Cautious optimism?

    Science.gov (United States)

    Alpern, Jonathan D; Lopez-Velez, Rogelio; Stauffer, William M

    2017-09-01

    Drugs for neglected tropical diseases (NTD) are being excessively priced in the United States. Benznidazole, the first-line drug for Chagas disease, may become approved by the Food and Drug Administration (FDA) and manufactured by a private company in the US, thus placing it at risk of similar pricing. Chagas disease is an NTD caused by Trypanosoma cruzi; it is endemic to Latin America, infecting 8 million individuals. Human migration has changed the epidemiology causing nonendemic countries to face increased challenges in diagnosing and managing patients with Chagas disease. Only 2 drugs exist with proven efficacy: benznidazole and nifurtimox. Benznidazole has historically faced supply problems and drug shortages, limiting accessibility. In the US, it is currently only available under an investigational new drug (IND) protocol from the CDC and is provided free of charge to patients. However, 2 companies have stated that they intend to submit a New Drug Application (NDA) for FDA approval. Based on recent history of companies acquiring licensing rights for NTD drugs in the US with limited availability, it is likely that benznidazole will become excessively priced by the manufacturer-paradoxically making it less accessible. However, if the companies can be taken at their word, there may be reason for optimism.

  5. Value of the radiological study of the thorax for diagnosing left ventricular dysfunction in Chagas' disease

    Directory of Open Access Journals (Sweden)

    Perez Amanda Arantes

    2003-01-01

    Full Text Available OBJECTIVE: To determine the value of the radiological study of the thorax for diagnosing left ventricular dilation and left ventricular systolic dysfunction in patients with Chagas' disease. METHODS: A cross-sectional study of 166 consecutive patients with Chagas' disease and no other associated diseases. The patients underwent cardiac assessment with chest radiography and Doppler echocardiography. Sensitivity, specificity, and positive and negative predictive values of chest radiography were calculated to detect left ventricular dysfunction and the accuracy of the cardiothoracic ratio in the diagnosis of left ventricular dysfunction with the area below the ROC curve. The cardiothoracic ratio was correlated with the left ventricular ejection fraction and the left ventricular diastolic diameter. RESULTS: The abnormal chest radiogram had a sensitivity of 50%, specificity of 80.5%, and positive and negative predictive values of 51.2% and 79.8%, respectively, in the diagnosis of left ventricular dysfunction. The cardiothoracic ratio showed a weak correlation with left ventricular ejection fraction (r=-0.23 and left ventricular diastolic diameter (r=0.30. The area calculated under the ROC curve was 0.734. CONCLUSION: The radiological study of the thorax is not an accurate indicator of left ventricular dysfunction; its use as a screening method to initially approach the patient with Chagas' disease should be reevaluated.

  6. Prevalence and Risk Factors for Chagas Disease in Pregnant Women in Casanare, Colombia

    Science.gov (United States)

    Cucunubá, Zulma M.; Flórez, Astrid C.; Cárdenas, Ángela; Pavía, Paula; Montilla, Marleny; Aldana, Rodrigo; Villamizar, Katherine; Ríos, Lyda C.; Nicholls, Rubén S.; Puerta, Concepción J.

    2012-01-01

    Knowledge of the prevalence and risk factors associated with maternal infection is the first step to develop a surveillance system for congenital transmission of Chagas disease. We conducted a cross-sectional study in Casanare, a disease-endemic area in Colombia. A total of 982 patients were enrolled in the study. A global prevalence of Trypanosoma cruzi infection of 4.0% (95% confidence interval [CI] = 2.8–5.3%) was found. Multivariate analysis showed that the most important risk-associated factors were age > 29 years (adjusted odds ratio [aOR] = 3.4, 95% CI = 0.9–12.4), rural residency (aOR = 2.2, 95% CI = 1.0–4.6), low education level (aOR = 10.2, 95% CI = 1.6–82.7), and previous knowledge of the vector (aOR = 2.2, 95% CI = 1.0–4.9). Relatives and siblings of infected mothers showed a prevalence of 9.3%. These findings may help physicians to investigate congenital cases, screen Chagas disease in siblings and relatives, and provide early treatment to prevent the chronic complications of Chagas disease. PMID:23033397

  7. Positive deviance study to inform a Chagas disease control program in southern Ecuador.

    Science.gov (United States)

    Nieto-Sanchez, Claudia; Baus, Esteban G; Guerrero, Darwin; Grijalva, Mario J

    2015-05-01

    Chagas disease is caused by Trypanosoma cruzi, which is mainly transmitted by the faeces of triatomine insects that find favourable environments in poorly constructed houses. Previous studies have documented persistent triatomine infestation in houses in the province of Loja in southern Ecuador despite repeated insecticide and educational interventions. We aim to develop a sustainable strategy for the interruption of Chagas disease transmission by promoting living environments that are designed to prevent colonisation of rural houses by triatomines. This study used positive deviance to inform the design of an anti-triatomine prototype house by identifying knowledge, attitudes and practices used by families that have remained triatomine-free (2010-2012). Positive deviants reported practices that included maintenance of structural elements of the house, fumigation of dwellings and animal shelters, sweeping with "insect repellent" plants and relocation of domestic animals away from the house, among others. Participants favoured construction materials that do not drastically differ from those currently used (adobe walls and tile roofs). They also expressed their belief in a clear connection between a clean house and health. The family's economic dynamics affect space use and must be considered in the prototype's design. Overall, the results indicate a positive climate for the introduction of housing improvements as a protective measure against Chagas disease in this region.

  8. Positive deviance study to inform a Chagas disease control program in southern Ecuador

    Directory of Open Access Journals (Sweden)

    Claudia Nieto-Sanchez

    2015-05-01

    Full Text Available Chagas disease is caused by Trypanosoma cruzi, which is mainly transmitted by the faeces of triatomine insects that find favourable environments in poorly constructed houses. Previous studies have documented persistent triatomine infestation in houses in the province of Loja in southern Ecuador despite repeated insecticide and educational interventions. We aim to develop a sustainable strategy for the interruption of Chagas disease transmission by promoting living environments that are designed to prevent colonisation of rural houses by triatomines. This study used positive deviance to inform the design of an anti-triatomine prototype house by identifying knowledge, attitudes and practices used by families that have remained triatomine-free (2010-2012. Positive deviants reported practices that included maintenance of structural elements of the house, fumigation of dwellings and animal shelters, sweeping with "insect repellent" plants and relocation of domestic animals away from the house, among others. Participants favoured construction materials that do not drastically differ from those currently used (adobe walls and tile roofs. They also expressed their belief in a clear connection between a clean house and health. The family's economic dynamics affect space use and must be considered in the prototype's design. Overall, the results indicate a positive climate for the introduction of housing improvements as a protective measure against Chagas disease in this region.

  9. The current screening programme for congenital transmission of Chagas disease in Catalonia, Spain.

    Science.gov (United States)

    Basile, L; Oliveira, I; Ciruela, P; Plasencia, A

    2011-09-22

    Due to considerable numbers of migrants from Chagas disease-endemic countries living in Catalonia, the Catalonian Health Department has recently implemented a screening programme for preventing congenital transmission, targeting Latin American pregnant women who attend antenatal consultations. Diagnosis of Trypanosoma cruzi infection in women is based on two positive serological tests. Screening of newborns from mothers with positive serology is based on a parasitological test during the first 48 hours of life and/or conventional serological analysis at the age of nine months. If either of these tests is positive, treatment with benznidazole is started following the World Health Organization's recommendations. The epidemiological surveillance of the programme is based on the Microbiological Reporting System of Catalonia, a well established network of laboratories. Once a positive case is reported, the responsible physician is asked to complete a structured epidemiological questionnaire. Clinical and demographic data are registered in the Voluntary Case Registry of Chagas Disease, a database administered by the Catalonian Health Department. It is expected that this programme will improve the understanding of the real burden of Chagas disease in the region. Furthermore, this initiative could encourage the implementation of similar programmes in other regions of Spain and even in other European countries.

  10. Prioritization Risk Integration Simulation Model (PRISM) For Environmental Remediation and Waste Management - 12097

    Energy Technology Data Exchange (ETDEWEB)

    Pentz, David L.; Stoll, Ralph H.; Greeves, John T. [Predicus LLC, Issaquah, WA 98027 (United States); Miller, R. Ian [GoldSim Technology Group, LLC, Issaquah, WA 98027 (United States); Nutt, W. Mark [Argonne National Laboratory, Argonne, IL 60439 (United States)

    2012-07-01

    The PRISM (Prioritization Risk Integration Simulation Model), a computer model was developed to support the Department of Energy's Office of Environmental Management (DOE-EM) in its mission to clean up the environmental legacy from the Nation's nuclear weapons materials production complex. PRISM provides a comprehensive, fully integrated planning tool that can tie together DOE-EM's projects. It is designed to help DOE managers develop sound, risk-informed business practices and defend program decisions. It provides a better ability to understand and manage programmatic risks. The underlying concept for PRISM is that DOE-EM 'owns' a portfolio of environmental legacy obligations (ELOs), and that its mission is to transform the ELOs from their current conditions to acceptable conditions, in the most effective way possible. There are many types of ELOs - - contaminated soils and groundwater plumes, disused facilities awaiting D and D, and various types of wastes waiting for processing or disposal. For a given suite of planned activities, PRISM simulates the outcomes as they play out over time, allowing for all key identified uncertainties and risk factors. Each contaminated building, land area and waste stream is tracked from cradle to grave, and all of the linkages affecting different waste streams are captured. The progression of the activities is fully dynamic, reflecting DOE-EM's prioritization approaches, precedence requirements, available funding, and the consequences of risks and uncertainties. The top level of PRISM is the end-user interface that allows rapid evaluation of alternative scenarios and viewing the results in a variety of useful ways. PRISM is a fully probabilistic model, allowing the user to specify uncertainties in input data (such as the magnitude of an existing groundwater plume, or the total cost to complete a planned activity) as well as specific risk events that might occur. PRISM is based on the GoldSim software

  11. Seroprevalencia de la enfermedad de Chagas en el cantón Aguarico, Amazonía ecuatoriana Seroprevalence of Chagas disease in Aguarico canton in the Ecuadorian Amazon

    Directory of Open Access Journals (Sweden)

    Manuel Amunárriz

    2010-07-01

    Full Text Available OBJETIVO: Determinar el estado actual de la seroprevalencia de la enfermedad de Chagas en la población del cantón Aguarico, y comparar los resultados obtenidos con datos provenientes de otros estudios epidemiológicos. MÉTODOS: Desde septiembre de 2008 hasta octubre de 2009 se recogieron 2 033 sueros correspondientes a 36,6% de la población total del cantón Aguarico. Se empleó la técnica CHAGATEST/ELISA recombinante v.3.0 para determinar positividad a la enfermedad de Chagas. Los casos positivos se confirmaron con pruebas de hemoaglutinación indirecta y ELISA. RESULTADOS: De las 2 033 muestras de suero obtenidas, 73 fueron positivas para Chagas (3,6%. El rango de variación de seroprevalencia en las comunidades con casos positivos osciló entre 1,4% y 13,3%. Un 60,3% de los casos positivos se encontraron en el sexo femenino. Estos hallazgos son similares a los de estudios previos de comparación realizados en 1990. CONCLUSIONES: Los datos obtenidos confirman la existencia de un foco autóctono de la enfermedad de Chagas en la Amazonía ecuatoriana, con un porcentaje superior a la media de la región amazónica. No se detectaron cuadros clínicos agudos ni patologías crónicas. Es perentorio implementar un programa de control de la enfermedad culturalmente adaptado a la región.OBJECTIVE: Determine the current seroprevalence of Chagas disease in the population of Aguarico canton, and compare the findings with data from other epidemiological studies. METHODS: From September 2008 to October 2009, 2 033 serum samples were collected from 36.6% of the total population in Aguarico canton. The Chagatest recombinant ELISA v.3.0 was used to determine positivity to Chagas disease. Cases that tested positive were confirmed by indirect hemagglutination and ELISA. RESULTS: Of the 2 033 serum samples obtained, 73 tested positive for Chagas disease (3.6%. Seroprevalence in communities with positive cases ranged from 1.4% to 13.3%, with 60.3% of the

  12. Illusory reversal of causality between touch and vision has no effect on prism adaptation rate

    Directory of Open Access Journals (Sweden)

    Hirokazu eTanaka

    2012-12-01

    Full Text Available Learning, according to Oxford Dictionary, is to gain knowledge or skill by studying, from experience, from being taught, etc. In order to learn from experience, the central nervous system has to decide what action leads to what consequence, and temporal perception plays a critical role in determining the causality between actions and consequences. In motor adaptation, causality between action and consequence is implicitly assumed so that a subject adapts to a new environment based on the consequence caused by her action. Adaptation to visual displacement induced by prisms is a prime example; the visual error signal associated with the motor output contributes to the recovery of accurate reaching, and a delayed feedback of visual error can decrease the adaptation rate. Subjective feeling of temporal order of action and consequence, however, can be modified or even reversed when her sense of simultaneity is manipulated with an artificially delayed feedback. Our previous study (Tanaka, Homma & Imamizu (2011 Exp Brain Res demonstrated that the rate of prism adaptation was unaffected when the subjective delay of visual feedback was shortened. This study asked whether subjects could adapt to prism adaptation and whether the rate of prism adaptation was affected when the subjective temporal order was illusory reversed. Adapting to additional 100 ms delay and its sudden removal caused a positive shift of point of simultaneity in a temporal-order judgment experiment, indicating an illusory reversal of action and consequence. We found that, even in this case, the subjects were able to adapt to prism displacement with the learning rate that was statistically indistinguishable to that without temporal adaptation. This result provides further evidence to the dissociation between conscious temporal perception and motor adaptation.

  13. Preapplication safety evaluation report for the Power Reactor Innovative Small Module (PRISM) liquid-metal reactor

    International Nuclear Information System (INIS)

    Donoghue, J.E.; Donohew, J.N.; Golub, G.R.; Kenneally, R.M.; Moore, P.B.; Sands, S.P.; Throm, E.D.; Wetzel, B.A.

    1994-02-01

    This preapplication safety evaluation report (PSER) presents the results of the preapplication desip review for die Power Reactor Innovative Small Module (PRISM) liquid-mew (sodium)-cooled reactor, Nuclear Regulatory Commission (NRC) Project No. 674. The PRISM conceptual desip was submitted by the US Department of Energy in accordance with the NRC's ''Statement of Policy for the Regulation of Advanced Nuclear Power Plants'' (51 Federal Register 24643). This policy provides for the early Commission review and interaction with designers and licensees. The PRISM reactor desip is a small, modular, pool-type, liquid-mew (sodium)-cooled reactor. The standard plant design consists of dim identical power blocks with a total electrical output rating of 1395 MWe- Each power block comprises three reactor modules, each with a thermal rating of 471 MWt. Each module is located in its own below-grade silo and is co to its own intermediate heat transport system and steam generator system. The reactors utilize a metallic-type fuel, a ternary alloy of U-Pu-Zr. The design includes passive reactor shutdown and passive decay heat removal features. The PSER is the NRC's preliminary evaluation of the safety features in the PRISM design, including the projected research and development programs required to support the design and the proposed testing needs. Because the NRC review was based on a conceptual design, the PSER did not result in an approval of the design. Instead it identified certain key safety issues, provided some guidance on applicable licensing criteria, assessed the adequacy of the preapplicant's research and development programs, and concluded that no obvious impediments to licensing the PRISM design had been identified

  14. Illusory Reversal of Causality between Touch and Vision has No Effect on Prism Adaptation Rate.

    Science.gov (United States)

    Tanaka, Hirokazu; Homma, Kazuhiro; Imamizu, Hiroshi

    2012-01-01

    Learning, according to Oxford Dictionary, is "to gain knowledge or skill by studying, from experience, from being taught, etc." In order to learn from experience, the central nervous system has to decide what action leads to what consequence, and temporal perception plays a critical role in determining the causality between actions and consequences. In motor adaptation, causality between action and consequence is implicitly assumed so that a subject adapts to a new environment based on the consequence caused by her action. Adaptation to visual displacement induced by prisms is a prime example; the visual error signal associated with the motor output contributes to the recovery of accurate reaching, and a delayed feedback of visual error can decrease the adaptation rate. Subjective feeling of temporal order of action and consequence, however, can be modified or even reversed when her sense of simultaneity is manipulated with an artificially delayed feedback. Our previous study (Tanaka et al., 2011; Exp. Brain Res.) demonstrated that the rate of prism adaptation was unaffected when the subjective delay of visual feedback was shortened. This study asked whether subjects could adapt to prism adaptation and whether the rate of prism adaptation was affected when the subjective temporal order was illusory reversed. Adapting to additional 100 ms delay and its sudden removal caused a positive shift of point of simultaneity in a temporal order judgment experiment, indicating an illusory reversal of action and consequence. We found that, even in this case, the subjects were able to adapt to prism displacement with the learning rate that was statistically indistinguishable to that without temporal adaptation. This result provides further evidence to the dissociation between conscious temporal perception and motor adaptation.

  15. The personalized reminder information and social management system (PRISM) trial: rationale, methods and baseline characteristics.

    Science.gov (United States)

    Czaja, Sara J; Boot, Walter R; Charness, Neil; A Rogers, Wendy; Sharit, Joseph; Fisk, Arthur D; Lee, Chin Chin; Nair, Sankaran N

    2015-01-01

    Technology holds promise in terms of providing support to older adults. To date, there have been limited robust systematic efforts to evaluate the psychosocial benefits of technology for older people and identify factors that influence both the usability and uptake of technology systems. In response to these issues, we developed the Personal Reminder Information and Social Management System (PRISM), a software application designed for older adults to support social connectivity, memory, knowledge about topics, leisure activities and access to resources. This trail is evaluating the impact of access to the PRISM system on outcomes such as social isolation, social support and connectivity. This paper reports on the approach used to design the PRISM system, study design, methodology and baseline data for the trial. The trial is multi-site randomized field trial. PRISM is being compared to a Binder condition where participants received a binder that contained content similar to that found on PRISM. The sample includes 300 older adults, aged 65-98 years, who lived alone and at risk for being isolated. The primary outcome measures for the trial include indices of social isolation and support and well-being. Secondary outcomes measures include indices of computer proficiency, technology uptake and attitudes towards technology. Follow-up assessments occurred at 6 and 12 months post-randomization. The results of this study will yield important information about the potential value of technology for older adults. The study also demonstrates how a user-centered iterative design approach can be incorporated into the design and evaluation of an intervention protocol. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Enfermedad de Chagas en poblaciones prehistóricas del norte de Chile Chagas disease in prehistoric populations of northern Chile

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    NANCY ORELLANA-HALKYER

    2010-12-01

    Full Text Available La enfermedad de Chagas es producida por el parásito Trypanosoma cruzi, el cual afecta tanto a seres humanos como a animales, en particular mamíferos marsupiales y placentarios. Las vías de transmisión son diversas, siendo una de las más importantes la vía vectorial, en la que participan insectos infectados con este parásito, animales y humanos. En este artículo de revisión discutimos los postulados sobre la vía de transmisión oral, los hallazgos de T. cruzi en momias de América y especialmente en las del norte de Chile. Presentamos además información que apunta a que la enfermedad de Chagas estuvo presente mucho antes de la conquista europea y de la construcción de viviendas de adobe. Comentamos las hipótesis sobre el vector domiciliado más importante de Sudamérica, Triatoma infestans, su antigüedad en la costa de Arica y los reportes más recientes de otros vectores silvestres. También se discute la información relacionada a la participación en el ciclo de T. cruzi de distintos mamíferos silvestres de Chile y asimismo proponemos el estudio paleoparasitológico en restos zooarqueológicos para conocer las especies de mamíferos reservónos de T. cruzi en la antigüedad.Chagas diseases is produced by a parasite named Trypanosoma cruzi, that affects humans and other marsupial and placental mammals. Transmission routes are diverse, but the most important transmission is the vector route, which involves the triatomine insects, wild and domestic infected animáis, and humans. Here we review the data about oral transmission route and the evidences of the etiological agent (Trypanosoma cruzi of Chagas disease in pre-Columbian American mummies, making a critical review of the infection in northern Chile. Moreover, we comment on the hypotheses suggested in relation to the most important vector of the infection in South América Triatoma infestans, its antiquity in the Arica coast, and the recent reports about other wild infected

  17. Estudo longitudinal do eletrocardiograma na doença de Chagas desde a fase aguda

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    Roberto C. Pedrosa

    1993-09-01

    Full Text Available Vários trabalhos com eletrocardiograma na doença de Chagas têm sido feitos. Alguns referindo-se a grupos selecionados de casos, outros a estudos longitudinais, relatam as características da mortalidade nas diversas fases da doença. Com o objetivo de avaliar o valor do eletrocardiograma como índice de avaliação terapêutica e de seu comportamento na doença de Chagas desde a fase aguda, no presente trabalho, analisou-se evolutivamente o eletrocardiograma de 42 pacientes (18 mulheres e 24 homens procedentes da zona rural do Norte de Minas Gerais; predomínio etário foi nas duas primeiras décadas; todos com comprometimento cardíaco; todos receberam tratamento específico. O acompanhamento dos 42 pacientes foi de 9 anos dos quais 3 pacientes tiveram seguimento de 20 anos. Foram analisados 270 eletrocardiogramas. Nós utilizamos os seguintes critérios para a análise do ECG: código de Minnesota modificado para doença de Chagas; WHO/I. S. F. C. TASK FORCE para condução intraventricular e critérios de Pieretti para área eletricamente inativa. Concluímos que as alterações eletrocardiográficas agravam com a evolução da doença e que o eletrocardiograma não serve de índice de avaliação terapêutica.Several studies have been done to analyse the relationship between the characteristics of the electrocardiogram (ECG and mortality in the several stages of the disease, using different methods like multiple case and longitudinal studies. We anatysed the ECGfrom the acute stage up to twenty years of follow-up (±9 years in 42 patients with Chagas ' disease to determine their evolution and it 's value like an indexfor therapeutic evaluation. The 42 patients (18 female, 24 males were originalty from the North of the State of Minas Gerais (Brazil and the initial stage was mainly in the first two decades of age. All bad cardiac involvementand received fiill specific treatment. We utilized the following criteria for the ECG analyses

  18. Chagas disease: what is known and what is needed - A background article

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    José Rodrigues Coura

    2007-10-01

    Full Text Available Chagas disease began millions of years ago as an enzootic disease of wild animals and started to be transmitted to man accidentally in the form of an anthropozoonosis when man invaded wild ecotopes. Endemic Chagas disease became established as a zoonosis over the last 200-300 years through forest clearance for agriculture and livestock rearing and adaptation of triatomines to domestic environments and to man and domestic animals as a food source. It is estimated that 15 to 16 million people are infected with Trypanosoma cruzi in Latin America and 75 to 90 million people are exposed to infection. When T. cruzi is transmitted to man through the feces of triatomines, at bite sites or in mucosa, through blood transfusion or orally through contaminated food, it invades the bloodstream and lymphatic system and becomes established in the muscle and cardiac tissue, the digestive system and phagocytic cells. This causes inflammatory lesions and immune responses, particularly mediated by CD4+, CD8+, interleukin-2 (IL and IL-4, with cell and neuron destruction and fibrosis, and leads to blockage of the cardiac conduction system, arrhythmia, cardiac insufficiency, aperistalsis, and dilatation of hollow viscera, particularly the esophagus and colon. T. cruzi may also be transmitted from mother to child across the placenta and through the birth canal, thus causing abortion, prematurity, and organic lesions in the fetus. In immunosuppressed individuals, T. cruzi infection may become reactivated such that it spreads as a severe disease causing diffuse myocarditis and lesions of the central nervous system. Chagas disease is characterized by an acute phase with or without symptoms, and with entry point signs (inoculation chagoma or Romaña's sign, fever, adenomegaly, hepatosplenomegaly, and evident parasitemia, and an indeterminate chronic phase (asymptomatic, with normal results from electrocardiogram and x-ray of the heart, esophagus, and colon or with a

  19. Chagas' disease: an algorithm for donor screening and positive donor counseling

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    Nelson Hamerschlak

    1997-06-01

    Full Text Available Classical serological screening assays for Chagas' disease are time consuming and subjective. The objective of the present work is to evaluate the enzyme immuno-assay (ELISA methodology and to propose an algorithm for blood banks to be applied to Chagas' disease. Seven thousand, nine hundred and ninety nine blood donor samples were screened by both reverse passive hemagglutination (RPHA and indirect immunofluorescence assay (IFA. Samples reactive on RPHA and/or IFA were submitted to supplementary RPHA, IFA and complement fixation (CFA tests. This strategy allowed us to create a panel of 60 samples to evaluate the ELISA methodology from 3 different manufacturers. The sensitivity of the screening by IFA and the 3 different ELISA's was 100%. The specificity was better on ELISA methodology. For Chagas disease, ELISA seems to be the best test for blood donor screening, because it showed high sensitivity and specificity, it is not subjective and can be automated. Therefore, it was possible to propose an algorithm to screen samples and confirm donor results at the blood bank.Os testes sorológicos clássicos utilizados na triagem de doadores de sangue são trabalhosos e subjetivos. O objetivo do presente trabalho é o de avaliar a metodologia imuno-enzimática (ELISA e propor um algorítmo para doença de Chagas em bancos de sangue. Foram estudados 7999 doadores de sangue e/ou componentes cujas amostras foram testadas com o objetivo de tria-las sorologicamente para doença de Chagas utilizando hemaglutinação passiva reversa (RPHA e imunofluorescência indireta (IFA. As amostras reativas em pelo menos uma destas metodologias, foram retestadas com reativos diferentes por RPHA, IFA e fixação de complemento (CFA. Esta estratégia nos permitiu criar um painel de 60 amostras com as quais tornou-se possível a avaliação do método imunoenzimático (ELISA. A sensibilidade da triagem dos doadores pelos métodos ELISA e IFA foi de 100%. A especificidade

  20. Chagas disease vector blood meal sources identified by protein mass spectrometry.

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    Judith I Keller

    Full Text Available Chagas disease is a complex vector borne parasitic disease involving blood feeding Triatominae (Hemiptera: Reduviidae insects, also known as kissing bugs, and the vertebrates they feed on. This disease has tremendous impacts on millions of people and is a global health problem. The etiological agent of Chagas disease, Trypanosoma cruzi (Kinetoplastea: Trypanosomatida: Trypanosomatidae, is deposited on the mammalian host in the insect's feces during a blood meal, and enters the host's blood stream through mucous membranes or a break in the skin. Identifying the blood meal sources of triatomine vectors is critical in understanding Chagas disease transmission dynamics, can lead to identification of other vertebrates important in the transmission cycle, and aids management decisions. The latter is particularly important as there is little in the way of effective therapeutics for Chagas disease. Several techniques, mostly DNA-based, are available for blood meal identification. However, further methods are needed, particularly when sample conditions lead to low-quality DNA or to assess the risk of human cross-contamination. We demonstrate a proteomics-based approach, using liquid chromatography tandem mass spectrometry (LC-MS/MS to identify host-specific hemoglobin peptides for blood meal identification in mouse blood control samples and apply LC-MS/MS for the first time to Triatoma dimidiata insect vectors, tracing blood sources to species. In contrast to most proteins, hemoglobin, stabilized by iron, is incredibly stable even being preserved through geologic time. We compared blood stored with and without an anticoagulant and examined field-collected insect specimens stored in suboptimal conditions such as at room temperature for long periods of time. To our knowledge, this is the first study using LC-MS/MS on field-collected arthropod disease vectors to identify blood meal composition, and where blood meal identification was confirmed with more

  1. Recuerdo del descubrimiento de la enfermedad de Chagas.

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    Hernando Groot Liévano

    2000-08-01

    Full Text Available

    A través de mis largos años he vivido en el trópico y he visto el sufrimiento de nuestros campesinos por esta grave dolencia y, a la par que he sido testigo de tal situación, he presenciado también los esfuerzos extraordinarios realizados en Colombia para su estudio y para su control, que a todos nos deben enorgullecer; estos fueron hechos en épocas recientes por personas como Augusto Corredor, Felipe Guhl y muchos otros investigadores que sería muy dispendioso enumerar.

    Años atrás los nombres de Benjamín Otálora, Hernando Ucrós y especialmente Santiago Renjifo y César Uribe Piedrahíta, tienen que venir a nuestra mente. Santiago Renjifo, investigador infatiga-ble de la enfermedad, fue además creador del Instituto “Roberto Franco” de Villavicencio y uno de los artífices más importantes de la Facultad de Medicina de la Universidad del Valle. A César Uribe Piedrahíta se debe, el haber iniciado el interés en Colombia por el estudio de esta parasitosis; fue él quien identificó por primera vez el agente causal en nuestro país. Así mismo formó un sinnúmero de investigadores que, con sus estudios, han dado luz sobre la dolencia y han sido lustre para la ciencia en América Latina.

    César Uribe Piedrahíta, mi profesor y luego mi amigo, es una de las personas de la medicina nacional que se debe exaltar con más vehemencia porque era el individuo que no solamente dominaba el campo médico sino que, como un Pico de la Mirán-dola del siglo XX, era experto en antropología, en arqueología, en botánica, habilísimo pintor y tallista, propulsor de las investigaciones sobre las bondades de las plantas, así como escritor de primera línea y dotado de excepcionales cualidades docentes para inculcar en sus estudiantes la disciplina por el estudio y la necesidad de trabajar cada vez más por este país.

    Parece oportuno que en estos momentos al rememorar a Carlos Chagas se haga un breve recuento de aquellas

  2. Transfer of memory trace of cerebellum-dependent motor learning in human prism adaptation: a model study.

    Science.gov (United States)

    Nagao, Soichi; Honda, Takeru; Yamazaki, Tadashi

    2013-11-01

    Accumulating experimental evidence suggests that the memory trace of ocular reflex adaptation is initially encoded in the cerebellar cortex, and later transferred to the cerebellar nuclei for consolidation through repetitions of training. However, the memory transfer is not well characterized in the learning of voluntary movement. Here, we implement our model of memory transfer to interpret the data of prism adaptation (Martin, Keating, Goodkin, Bastian, & Thach, 1996a, 1996b), assuming that the cerebellar nuclear memory formed by memory transfer is used for normal throwing. When the subject was trained to throw darts wearing prisms in 30-40 trials, the short-term memory for recalibrating the throwing direction by gaze would be formed in the cerebellar cortex, which was extinguished by throwing with normal vision in a similar number of trials. After weeks of repetitions of short-term prism adaptation, the long-term memory would be formed in the cerebellar nuclei through memory transfer, which enabled one to throw darts to the center wearing prisms without any training. These two long-term memories, one for throwing with normal vision and the other for throwing wearing prisms, are assumed to be utilized automatically under volitional control. Moreover, when the prisms were changed to new prisms, a new memory for adapting to the new prisms would be formed in the cerebellar cortex, just to counterbalance the nuclear memory of long-term adaptation to the original prisms in a similar number of trials. These results suggest that memory transfer may occur in the learning of voluntary movements. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Eu3+-doped Y2O3 hexagonal prisms: Shape-controlled synthesis and tailored luminescence properties

    International Nuclear Information System (INIS)

    Yang, Errui; Li, Guangshe; Fu, Chaochao; Zheng, Jing; Huang, Xinsong; Xu, Wen; Li, Liping

    2015-01-01

    In this work, Eu 3+ doped Y 2 O 3 hexagonal prisms were synthesized by a novel two-phase approach, which involves water at the bottom as aqueous phase and oleylamine in the above as oil phase. With this unique reaction system, precursors of hexagonal prisms Y 4 O(OH) 9 (NO 3 ) were first obtained by simply varying the volume ratio of water to oleylamine. Time-dependent experiments were systematically performed to reveal the growth mechanism of the precursor. After subsequent heat treatment, these precursors transformed to Y 2 O 3 hexagonal prisms with controlled diameters and aspect ratios varying from 4 to 19. Such a transformation is preceded via a topotactic process, as indicated by TG-DTA and mass spectra. Eventually, all Eu 3+ doped Y 2 O 3 hexagonal prisms were found to exhibit an intensive red emission at 611 nm, which corresponds to 5 D 0 → 7 F 2 transition of Eu 3+ . With varying the aspect ratio of hexagonal prisms and increasing Eu 3+ concentration in Y 2 O 3 , an optimum external quantum efficiency was achieved. - Graphical abstract: In this work, Eu 3+ doped Y 2 O 3 hexagonal prisms with controlled aspect ratio from 4.4 to 19.3 were synthesized by transformation of the precursor Y 4 O(OH) 9 (NO 3 ) hexagonal prisms from a novel two-phase reaction system. The growth mechanism of the precursor has been systematically investigated, and a topotactic phase transformation from precursors to cubic Y 2 O 3 is for the first time put forward. By the size controlling and aspect ratio adjusting, the luminescence emission intensity as well as external quantum efficiency of Eu 3+ doped Y 2 O 3 hexagonal prisms is further tailored to show an optimum. - Highlights: • Eu 3+ doped Y 2 O 3 hexagonal prisms were synthesized by a novel two-phase approach. • Inheriting mechanism of prisms morphology from Y 4 O(OH) 9 (NO 3 ) to Y 2 O 3 was discussed. • Aspect ratio of prisms was tailored by the volume ratio of water to oleylamine. • Luminescence properties were

  4. A ciência como profissão: entrevista com Carlos Chagas Filho Science as a profession: an interview with Carlos Chagas Filho

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    Nara Azevedo

    2012-06-01

    Full Text Available A edição desta entrevista privilegia aspectos da extensa trajetória profissional de Carlos Chagas Filho, fundador do Instituto de Biofísica da Universidade do Brasil, atual Universidade Federal do Rio de Janeiro. Evidencia seu papel científico e político na ciência brasileira e no cenário internacional. As memórias de Chagas Filho abrangem a vivência no Instituto Oswaldo Cruz, onde iniciou seu treinamento científico; os esforços para estruturar o Laboratório de Física Biológica, sucedido pelo Instituto de Biofísica; a atuação no Conselho Nacional de Pesquisas e na Academia Brasileira de Ciências; a participação na Organização das Nações Unidas para a Educação, a Ciência e a Cultura; a presidência da Academia Pontifícia do Vaticano, que o leva a tecer considerações sobre a relação entre ciência e religião.The editing of this interview focuses on aspects of the extensive professional career of Carlos Chagas Filho, who was the founder of the Instituto de Biofísica of the Universidade do Brasil, currently the Universidade Federal do Rio de Janeiro. It highlights the scientific and political role he played in Brazilian science and on the international scene. His memoirs include his experience at the Instituto Oswaldo Cruz, where he began his scientific training; the efforts to create the Laboratório de Física Biológica, succeeded by the Instituto de Biofísica; his work on the Conselho Nacional de Pesquisas and the Academia Brasileira de Ciências; the part he played at the United Nations Educational, Scientific and Cultural Organization; his time as president of the Pontifical Academy of Sciences of the Vatican, which led him to ponder questions about the relationship between science and religion.

  5. Area-wide control of Chagas disease vectors in Latin America

    International Nuclear Information System (INIS)

    Schofield, C.J.

    2000-01-01

    Chagas disease (American trypanosomiasis) is now ranked by the World Bank as the most serious parasitic disease of the Americas, with a medical and economic impact far outranking even the combined effects of other parasitic diseases such as malaria and schistosomiasis (World Bank 1993). The infection is virtually impossible to cure and the disease is difficult and costly to treat. In contrast, transmission can be halted by eliminating the domestic insect vectors - large blood sucking reduviids of the subfamily Triatominae - and by improved screening of blood donors to minimise the risk of transfusional transmission (WHO 1991). Improved screening of blood banks requires appropriate legislation backed by a well-developed system of reference laboratories and standardised procedures, although to a large extent, this can be implemented in a progressive way from local to national levels (Schmunis 1991). By contrast, the key to success in Chagas disease vector control lies in the implementation of large-scale regional or international programmes coupled with long-term community-based vigilance. This is a classic intervention model beginning with a vertical intervention, the attack phase, in which all infested houses are sprayed by trained professionals, progressively backed by a more horizontal community-based system where householders themselves can report the presence of any residual infestations for retreatment where necessary. Elimination of domestic vectors of Chagas disease is facilitated by their slow reproductive rates and limited genetic variability, but is hampered by the ease of passive transport of the insects from one house to another, even across state and international boundaries (Schofield 1994). For this reason, international collaboration is particularly important in Chagas disease vector control. Since early trials in the 1940s, there have been many local and regional campaigns designed to control domestic populations of Triatominae, especially in

  6. Next-generation ELISA diagnostic assay for Chagas Disease based on the combination of short peptidic epitopes

    DEFF Research Database (Denmark)

    Mucci, Juan; Carmona, Santiago J.; Volcovich, Romina

    2017-01-01

    Chagas Disease, caused by the protozoan Trypanosoma cruzi, is a major health and economic problem in Latin America for which no vaccine or appropriate drugs for large-scale public health interventions are yet available. Accurate diagnosis is essential for the early identification and follow up....... cruzi linear B-cell epitopes using high-density peptide chips, leading to the identification of several hundred novel sequence signatures associated to chronic Chagas Disease. Here, we performed a serological assessment of 27 selected epitopes and of their use in a novel multipeptide-based diagnostic...... method. A combination of 7 of these peptides were finally evaluated in ELISA format against a panel of 199 sera samples (Chagas-positive and negative, including sera from Leishmaniasis-positive subjects). The multipeptide formulation displayed a high diagnostic performance, with a sensitivity of 96...

  7. Seroprevalence and sociocultural conditionants of Chagas disease in school aged children of marginal zones of Asunción

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    Vera Ninfa I.

    1998-01-01

    Full Text Available Chagas disease is becoming a public health problem in Latin America due to the wide distribution, the high prevalence, the magnitude of the damage caused and the difficulties to control it. In Paraguay, the disease is mainly distributed in the departments of Paraguari, Cordillera and Central. Prevalence in marginal zones, where migrations from rural populations and endemic areas make possible the urbanization of the disease, has no been studied yet. This is a descriptive study with a cross-sectional sampling and a probabilistic system recruitment carried out in school aged children from marginal zones of Asuncion to determine the prevalence of Chagas' disease. Serological methods, parasite isolation and questionnaires were used to achieve the goals. Nine hundred and fifty three children were studied to determine the prevalence of Chagas' disease in marginal zones which was 1.4%.

  8. Comparison of parasite loads in serum and blood samples from patients in acute and chronic phases of Chagas disease.

    Science.gov (United States)

    Hernández, Carolina; Teherán, Aníbal; Flórez, Carolina; Ramírez, Juan David

    2018-04-17

    Molecular methods have been developed for the detection and quantification of Trypanosoma cruzi DNA in blood samples from patients with Chagas disease. However, aspects of sample processing necessary for quantitative real-time PCR (qPCR), such as the addition of guanidine hydrochloride to whole blood samples, may limit timely access to molecular diagnosis. We analysed 169 samples from serum and guanidine-EDTA blood (GEB) obtained from patients in acute and chronic phases of Chagas disease. We applied qPCR targeted to the satellite DNA region. Finally, we compared the parasite loads and cycle of threshold values of the qPCR. The results confirmed the usefulness of serum samples for the detection and quantification of parasite DNA in patients with Chagas disease, especially in the acute phase. However, the parasite loads detected in serum samples from patients in the chronic phase were lower than those detected in GEB samples. The epidemiological implications of the findings are herein discussed.

  9. Discrete typing units of Trypanosoma cruzi detected by real-time PCR in Chilean patients with chronic Chagas cardiomyopathy.

    Science.gov (United States)

    Muñoz-San Martín, Catalina; Zulantay, Inés; Saavedra, Miguel; Fuentealba, Cristián; Muñoz, Gabriela; Apt, Werner

    2018-05-07

    Chagas disease is a major public health problem in Latin America and has spread to other countries due to immigration of infected persons. 10-30% of patients with chronic Chagas disease will develop cardiomyopathy. Chagas cardiomyopathy is the worst form of the disease, due to its high morbidity and mortality. Because of its prognostic value and adequate medical monitoring, it is very important to identify infected people who could develop Chagas cardiomyopathy. The aim of this study was to determine if discrete typing units (DTUs) of Trypanosoma cruzi are related to the presence of heart disease in patients with chronic Chagas disease. A total of 86 untreated patients, 41 with cardiomyopathy and 45 without heart involvement were submitted to clinical study. Electrocardiograms and echocardiograms were performed on the group of cardiopaths, in which all important known causes of cardiomyopathy were discarded. Sinus bradycardia and prolonged QTc interval were the most frequent electrocardiographic alterations and patients were classified in group I (46%) and group II (54%) of New York Hearth Association. In all cases real-time PCR genotyping assays were performed. In the group with cardiomyopathy, the most frequent DTU was TcI (56.1%), followed by TcII (19.5%). Mixed infections TcI + TcII were observed in 7.3% of the patients. In the group without cardiac pathologies, TcI and TcII were found at similar rates (28.9 and 31.1%, respectively) and mixed infections TcI + TcII in 17.8% of the cases. TcIII and TcIV were not detected in any sample. Taken together, our data indicate that chronic Chagas cardiomyopathy in Chile can be caused by strains belonging to TcI and TcII. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. How universal is coverage and access to diagnosis and treatment for Chagas disease in Colombia? A health systems analysis.

    Science.gov (United States)

    Cucunubá, Zulma M; Manne-Goehler, Jennifer M; Díaz, Diana; Nouvellet, Pierre; Bernal, Oscar; Marchiol, Andrea; Basáñez, María-Gloria; Conteh, Lesong

    2017-02-01

    Limited access to Chagas disease diagnosis and treatment is a major obstacle to reaching the 2020 World Health Organization milestones of delivering care to all infected and ill patients. Colombia has been identified as a health system in transition, reporting one of the highest levels of health insurance coverage in Latin America. We explore if and how this high level of coverage extends to those with Chagas disease, a traditionally marginalised population. Using a mixed methods approach, we calculate coverage for screening, diagnosis and treatment of Chagas. We then identify supply-side constraints both quantitatively and qualitatively. A review of official registries of tests and treatments for Chagas disease delivered between 2008 and 2014 is compared to estimates of infected people. Using the Flagship Framework, we explore barriers limiting access to care. Screening coverage is estimated at 1.2% of the population at risk. Aetiological treatment with either benznidazol or nifurtimox covered 0.3-0.4% of the infected population. Barriers to accessing screening, diagnosis and treatment are identified for each of the Flagship Framework's five dimensions of interest: financing, payment, regulation, organization and persuasion. The main challenges identified were: a lack of clarity in terms of financial responsibilities in a segmented health system, claims of limited resources for undertaking activities particularly in primary care, non-inclusion of confirmatory test(s) in the basic package of diagnosis and care, poor logistics in the distribution and supply chain of medicines, and lack of awareness of medical personnel. Very low screening coverage emerges as a key obstacle hindering access to care for Chagas disease. Findings suggest serious shortcomings in this health system for Chagas disease, despite the success of universal health insurance scale-up in Colombia. Whether these shortcomings exist in relation to other neglected tropical diseases needs investigating

  11. Protective human leucocyte antigen haplotype, HLA-DRB1*01-B*14, against chronic Chagas disease in Bolivia.

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    Florencia del Puerto

    Full Text Available BACKGROUND: Chagas disease, caused by the flagellate parasite Trypanosoma cruzi affects 8-10 million people in Latin America. The mechanisms that underlie the development of complications of chronic Chagas disease, characterized primarily by pathology of the heart and digestive system, are not currently understood. To identify possible host genetic factors that may influence the clinical course of Chagas disease, Human Leucocyte Antigen (HLA regional gene polymorphism was analyzed in patients presenting with differing clinical symptoms. METHODOLOGY: Two hundred and twenty nine chronic Chagas disease patients in Santa Cruz, Bolivia, were examined by serological tests, electrocardiogram (ECG, and Barium enema colon X-ray. 31.4% of the examinees showed ECG alterations, 15.7% megacolon and 58.1% showed neither of them. A further 62 seropositive megacolon patients who had undergone colonectomy due to acute abdomen were recruited. We analyzed their HLA genetic polymorphisms (HLA-A, HLA-B, MICA, MICB, DRB1 and TNF-alpha promoter region mainly through Sequence based and LABType SSO typing test using LUMINEX Technology. PRINCIPAL FINDINGS: The frequencies of HLA-DRB1*01 and HLA-B*14:02 were significantly lower in patients suffering from megacolon as well as in those with ECG alteration and/or megacolon compared with a group of patients with indeterminate symptoms. The DRB1*0102, B*1402 and MICA*011 alleles were in strong Linkage Disequilibrium (LD, and the HLA-DRB1*01-B*14-MICA*011 haplotype was associated with resistance against chronic Chagas disease. CONCLUSIONS: This is the first report of HLA haplotype association with resistance to chronic Chagas disease.

  12. Impact of Helminth Infection on the Clinical and Microbiological Presentation of Chagas Diseases in Chronically Infected Patients.

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    Fernando Salvador

    2016-04-01

    Full Text Available Helminth infections are highly prevalent in tropical and subtropical countries, coexisting in Chagas disease endemic areas. Helminth infections in humans may modulate the host immune system, changing the Th1/Th2 polarization. This immunological disturbance could modify the immune response to other infections. The aim of this study is to evaluate the relationship between clinical, microbiological and epidemiological characteristics of Chagas disease patients, with the presence of helminth infection.A prospective observational study was conducted at Vall d'Hebron University Hospital (Barcelona, Spain. Inclusion criteria were: age over 18 years, diagnosis of Chagas disease, and not having received specific treatment for Chagas disease previously to the inclusion. The study protocol included Chagas disease assessment (cardiac and digestive evaluation, detection of T. cruzi DNA measured by PCR in peripheral blood, and helminth infection diagnosis (detection of IgG anti-Strongyloides stercoralis by ELISA, microscopic examination of stool samples from three different days, and specific faecal culture for S. stercoralis larvae.Overall, 65 patients were included, median age was 38 years, 75.4% were women and most of them came from Bolivia. Cardiac and digestive involvement was present in 18.5% and 27.7% of patients respectively. T. cruzi PCR was positive in 28 (43.1% patients. Helminth infection was diagnosed in 12 (18.5% patients. No differences were observed in clinical and epidemiological characteristics between patients with and without helminth infection. Nevertheless, the proportion of patients with positive T. cruzi PCR was higher among patients with helminth infection compared with patients without helminth infection (75% vs 35.8%, p = 0.021.We observed a high prevalence of S. stercoralis infection among chronic Chagas disease patients attended in our tropical medicine unit. Strongyloidiasis was associated with significantly higher proportion of

  13. Evaluation of the Chagas disease control program in Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil.

    Science.gov (United States)

    Santos, Adriana dos; Letro, Rejane Balmant; Lemos do Bem, Vitor Antônio; Azeredo, Bernardino Vaz de Melo; Coelho, George Luiz Lins Machado; Diotaiuti, Liléia; Machado-de-Assis, Girley Francisco; de Lana, Marta

    2014-01-01

    Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil temporarily (2001-2005) interrupted epidemiological surveillance for Chagas disease. The objective of this work was to evaluate the Chagas Disease Control Program (CDCP) in Açucena and to offer suggestions for improving local epidemiological surveillance. This study was conducted in three phases: I) a serological investigation of schoolchildren aged 5 to 15 years using an enzyme-linked immunosorbent assay (ELISA) test performed on blood collected on filter paper followed by ELISA, indirect immunofluorescence (IIF) and indirect hemaglutination (IHA) on venous blood for borderline cases and those in the gray zone of reactivity; II) vector evaluation using the data obtained by local health agents during 2006-2010; and III) examination by ELISA, IIF and IHA of serum samples from the inhabitants of houses where infected Triatoma vitticeps was found and evaluation of their knowledge about Chagas disease. Five individuals had inconclusive results in the ELISA screening but were seronegative for Chagas disease. The triatomine evaluation revealed the presence of three species: Triatoma vitticeps, Panstrongylus megistus and Panstrongylus diasi. Triatoma vitticeps was the most prevalent and widespread, with a higher (67%) index of Trypanosoma cruzi flagellates and evidence of colonization. Most of the inhabitants of the infested houses recognized triatomines and had basic knowledge about Chagas disease. Although T. vitticeps is not clearly associated with Chagas disease transmission, these results highlight the importance of maintaining CDCP in endemic areas and the need for greater emphasis on epidemiological surveillance, especially in areas with important vectorial changes or that have been modified by human intervention.

  14. Evaluation of the Chagas Disease Control Program in Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Adriana dos Santos

    2014-04-01

    Full Text Available Introduction Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil temporarily (2001-2005 interrupted epidemiological surveillance for Chagas disease. The objective of this work was to evaluate the Chagas Disease Control Program (CDCP in Açucena and to offer suggestions for improving local epidemiological surveillance. Methods This study was conducted in three phases: I a serological investigation of schoolchildren aged 5 to 15 years using an enzyme-linked immunosorbent assay (ELISA test performed on blood collected on filter paper followed by ELISA, indirect immunofluorescence (IIF and indirect hemaglutination (IHA on venous blood for borderline cases and those in the gray zone of reactivity; II vector evaluation using the data obtained by local health agents during 2006-2010; and III examination by ELISA, IIF and IHA of serum samples from the inhabitants of houses where infected Triatoma vitticeps was found and evaluation of their knowledge about Chagas disease. Results Five individuals had inconclusive results in the ELISA screening but were seronegative for Chagas disease. The triatomine evaluation revealed the presence of three species: Triatoma vitticeps, Panstrongylus megistus and Panstrongylus diasi. Triatoma vitticeps was the most prevalent and widespread, with a higher (67% index of Trypanosoma cruzi flagellates and evidence of colonization. Most of the inhabitants of the infested houses recognized triatomines and had basic knowledge about Chagas disease. Conclusions Although T. vitticeps is not clearly associated with Chagas disease transmission, these results highlight the importance of maintaining CDCP in endemic areas and the need for greater emphasis on epidemiological surveillance, especially in areas with important vectorial changes or that have been modified by human intervention.

  15. Accelerated Determination of ASR Susceptibility during Concrete Prism Testing through Nonlinear Resonance Ultrasonic Spectroscopy : TechBrief

    Science.gov (United States)

    2013-10-01

    The research has been conducted on laboratory-cast concrete prism specimens containing both fine and coarse aggregates obtained from different sources to provide a spectrum of reactivity for assessment through the developed NIRAS technique. The NIRAS...

  16. Experimental Evaluation of Lightweight AAC Masonry Wall Prisms with Ferrocement Layers in Compression and Flexure

    KAUST Repository

    Abdel Mooty, Mohamed; Hendam, Ahmed; Fahmy, Ezzat; Abou Zeid, Mohamed; Haroun, Medhat

    2012-01-01

    An experimental program is designed to evaluate the performance of lightweight autoclaved aerated concrete masonry wall strengthened using ferrocement layers, in a sandwich structure, under in-plane compression and out-of-plane bending. The 25 mm thick ferrocement mortar is reinforced with steel welded wire mesh of 1 mm diameters at 15 mm spacing. Different types of shear connectors are used to evaluate their effect on failure loads. The effect of different design parameters on the wall strength are considered including wall thickness, mortar strength, and type and distribution of shear connectors. A total of 20 prisms are tested in compression and 5 prisms are tested under bending. The proposed ferrocement strengthening technique is easy to apply on existing wall system and results in significant strength and stiffness enhancement of the tested wall specimens. © (2012) Trans Tech Publications.

  17. Moving forward with prisms: Sensory-motor adaptation improves gait initiation in Parkinson’s disease.

    Directory of Open Access Journals (Sweden)

    Janet Helen Bultitude

    2012-09-01

    Full Text Available It is postulated that the decreased walking speed; small, shuffling steps; and ‘freezing’ shown by patients with Parkinson’s disease could stem from an inability to tilt the body forward enough to provide sufficient forward propulsion. In two repeated-measures studies we examined whether adaptation to upward-shifting prisms, resulting in a downward after-effect, could improve gait initiation in healthy participants and patients with Parkinson’s disease. Faster forward stepping followed a brief (5 min exposure period for patients, and a longer (20 min exposure period for age-matched controls. Backward stepping was unchanged, and adaptation to downward-shifting prisms with control participants showed no effect on forward or backward stepping. These results suggest that adaptation of arm proprioception in the vertical plane may generalise to anterior-posterior postural control, presenting new possibilities for the treatment of gait disturbance in basal ganglia disorders.

  18. Facile synthesis and photoluminescence spectroscopy of 3D-triangular GaN nano prism islands.

    Science.gov (United States)

    Kumar, Mukesh; Pasha, S K; Shibin Krishna, T C; Singh, Avanish Pratap; Kumar, Pawan; Gupta, Bipin Kumar; Gupta, Govind

    2014-08-21

    We report a strategy for fabrication of 3D triangular GaN nano prism islands (TGNPI) grown on Ga/Si(553) substrate at low temperature by N2(+) ions implantation using a sputtering gun technique. The annealing of Ga/Si(553) (600 °C) followed by nitridation (2 keV) shows the formation of high quality GaN TGNPI cross-section. TGNPI morphology has been confirmed by atomic force microscopy. Furthermore, these nano prism islands exhibit prominent ultra-violet luminescence peaking at 366 nm upon 325 nm excitation wavelength along with a low intensity yellow luminescence broad peak at 545 nm which characterizes low defects density TGNPI. Furthermore, the time-resolved spectroscopy of luminescent TGNPI in nanoseconds holds promise for its futuristic application in next generation UV-based sensors as well as many portable optoelectronic devices.

  19. Experimental Evaluation of Lightweight AAC Masonry Wall Prisms with Ferrocement Layers in Compression and Flexure

    KAUST Repository

    Abdel Mooty, Mohamed

    2012-05-01

    An experimental program is designed to evaluate the performance of lightweight autoclaved aerated concrete masonry wall strengthened using ferrocement layers, in a sandwich structure, under in-plane compression and out-of-plane bending. The 25 mm thick ferrocement mortar is reinforced with steel welded wire mesh of 1 mm diameters at 15 mm spacing. Different types of shear connectors are used to evaluate their effect on failure loads. The effect of different design parameters on the wall strength are considered including wall thickness, mortar strength, and type and distribution of shear connectors. A total of 20 prisms are tested in compression and 5 prisms are tested under bending. The proposed ferrocement strengthening technique is easy to apply on existing wall system and results in significant strength and stiffness enhancement of the tested wall specimens. © (2012) Trans Tech Publications.

  20. Using the accelerated Brazilian concrete prism test (ABCPT to evaluate alkali aggregate reaction (AAR

    Directory of Open Access Journals (Sweden)

    L. Sanchez

    Full Text Available There are many test methods used in the laboratory to detect potential alkali-aggregate reactions (AAR. However, up to now, there is no consensus if they are reliable and efficient. This work presents the development of a new and accelerated concrete prism test called ABCPT (accelerate Brazilian concrete prism test as an attempt to create a reliable and fast test that can analyze and classify the potential reactivity of aggregates in the laboratory. For this research, six aggregates from different lithotypes were used. The methods CPT, ACPT and ABCPT were carried out with all the aggregates and a comparative analysis among all tests was performed. ABCPT seems to have a great potential to analyze and classify aggregates in the laboratory, although it needs further testing with other lithotypes to be confirmed as feasible.

  1. Progress on PRISM, an inherently safe, economic, and testable advanced liquid metal reactor

    International Nuclear Information System (INIS)

    Tippets, F.E.; Salerno, L.N.; Boardman, C.E.; Kwant, W.; Murata, R.E.; Snyder, C.R.

    1987-01-01

    This paper reports progress on the design of PRISM (Power Reactor Inherently Safe Module) under the DOE-sponsored innovative reactor program now in its third year at General Electric. The purpose of this program is to develop a design for an inherently safe, reliable, and marketable liquid metal fast reactor power plant. The PRISM design approach includes the following key elements: Compact sodium-cooled pool-type reactor modules that are sized to enable factory fabrication, economical shipment to inland as well as water-side sites, and economical full-scale prototype testing for design certification; Nuclear safety-related envelope limited to the reactor modules and their service systems; Inherent, passive shutdown heat removal for loss-of-cooling events; Inherent, passive reactivity shutdown for failure-to-scram events

  2. Analysis of the applicability of acceleration methods for a triangular prism geometry nodal diffusion code

    International Nuclear Information System (INIS)

    Fujimura, Toichiro; Okumura, Keisuke

    2002-11-01

    A prototype version of a diffusion code has been developed to analyze the hexagonal core as reduced moderation reactor and the applicability of some acceleration methods have been investigated to accelerate the convergence of the iterative solution method. The hexagonal core is divided into regular triangular prisms in the three-dimensional code MOSRA-Prism and a polynomial expansion nodal method is applied to approximate the neutron flux distribution by a cubic polynomial. The multi-group diffusion equation is solved iteratively with ordinal inner and outer iterations and the effectiveness of acceleration methods is ascertained by applying an adaptive acceleration method and a neutron source extrapolation method, respectively. The formulation of the polynomial expansion nodal method is outlined in the report and the local and global effectiveness of the acceleration methods is discussed with various sample calculations. A new general expression of vacuum boundary condition, derived in the formulation is also described. (author)

  3. Watching Nanoscale Self-Assembly Kinetics of Gold Prisms in Liquids

    Science.gov (United States)

    Kim, Juyeong; Ou, Zihao; Jones, Matthew R.; Chen, Qian

    We use liquid-phase transmission electron microscopy to watch self-assembly of gold triangular prisms into polymer-like structures. The in situ dynamics monitoring enabled by liquid-phase transmission electron microscopy, single nanoparticle tracking, and the marked conceptual similarity between molecular reactions and nanoparticle self-assembly combined elucidate the following mechanistic understanding: a step-growth polymerization based assembly statistics, kinetic pathways sampling particle curvature dependent energy minima and their interconversions, and directed assembly into polymorphs (linear or cyclic chains) through in situ modulation of the prism bonding geometry. Our study bridges the constituent kinetics on the molecular and nanoparticle length scales, which enriches the design rules in directed self-assembly of anisotropic nanoparticles.

  4. PERANCANGAN SISTEM PENGUKURAN KINERJA DENGAN METODE PERFORMANCE PRISM (Studi Kasus di Plaza Hotel Semarang

    Directory of Open Access Journals (Sweden)

    Hery Suliantoro

    2012-03-01

    Full Text Available Selama ini Plaza hotel belum pernah melakukan pengukuran kinerja yang terintegrasi yang terdiri dari aspek finansial dan non finansial. Dilihat dari prosentase tingkat hunian yang tidak memenuhi target yang ditetapkan, maka pengukuran kinerja yang terintegrasi diharapkan mampu memberikan perbaikan kinerja yang diharapkan. Dengan menggunakan performance prism, dilakukan identifikasi kebutuhan dan kontribusi stakeholder secara keseluruhan sehingga didapat indikator kinerja dari kriteria strategi, proses dan kapabilitas yang dijadikan tolok ukur perbaikan kinerja.. tahap pengumpulan data dengan menyebarkan matriks perbandingan berpasangan sebagai dasar penyusunan bobot kepentingan pada AHP dan kuesioner target pencapaian kinerja sebagai dasar penetapan skor aktual pada OMAX. Dari analisis yang dilakukan setelah bobot kepentingan diperoleh dan perhitungan nilai performansi, dilakukan simulasi perbaikan satu-satuan nilai performansi agar didapat kriteria dan elemen apa saja yang mendapat prioritas perbaikan dan rekomendasi perbaikan yang perlu dilakukan untuk meningkatkan kinerja Plaza Hotel Semarang. Kata kunci : Performance Prism, AHP, OMAX, skor aktual

  5. The Refractive Index Measurement Of Silicon Dioxide Thin Film by the Coupling Prism Method

    International Nuclear Information System (INIS)

    Budianto, Anwar; Hariyanto, Sigit; Subarkah

    1996-01-01

    Refractive index of silicon dioxide thin film that doped with phosphor (SiO 2 :P) above the pure silicon dioxide substrate has been measured by light coupling prism method. The method principle is focusing the light on coupling prism base so that the light propagates into the waveguide layer while the reflected one forms a mode in the observation plane. The SiO 2 thin film as waveguide layer has a refractive index that give the thick and refractive index relation. The He-Ne laser as light source has the wavelength λ 0,6328 μm. The refractive index measurement of the thin film with the substrate refractive index n sb = 1,47 and the thin film thick d = 2μm gives n g = 1,5534 ± 0,01136. This method can distinguish the refractive index of thin film about 6% to the refractive index of substrate

  6. Doença de Chagas: Desafios no Desenvolvimento de Novas Substâncias Líderes Tripanomicidas

    OpenAIRE

    Fernando de C. da Silva; Universidade Federal Fluminense; Sabrina B. Ferreira; Universidade Federal do Rio de Janeiro; David R. da Rocha; Universidade Federal Fluminense; Vitor F. Ferreira; Universidade Federal Fluminense

    2012-01-01

    A doença de Chagas teve seu ciclo completamente elucidado em 1909 por Carlos Chagas, quando ele relatou sua descoberta para a comunidade científica em dois artigos seminais. Hoje ainda existem inúmeros fatores que limitam o seu tratamento terapêutico. Um deles é a falta de novas drogas no mercado, pois é bem conhecido que as drogas existentes são fracamente ativas e tem baixa eficácia e consideráveis efeitos colaterais. Atualmente muitos esforços têm sido feito em química combinatória e sínte...

  7. Synthetic Medicinal Chemistry in Chagas' Disease: Compounds at The Final Stage of "Hit-To-Lead" Phase.

    Science.gov (United States)

    Cerecetto, Hugo; González, Mercedes

    2010-03-25

    Chagas' disease, or American trypanosomosiasis, has been the most relevant illness produced by protozoa in Latin America. Synthetic medicinal chemistry efforts have provided an extensive number of chemodiverse hits at the "active-to-hit" stage. However, only a more limited number of these have been studied in vivo in models of Chagas' disease. Herein, we survey some of the cantidates able to surpass the "hit-to-lead" stage discussing their limitations or merit to enter in clinical trials in the short term.

  8. Advanced megaesophagus (Group III secondary to vector-borne Chagas disease in a 20-month-old infant

    Directory of Open Access Journals (Sweden)

    Anis Rassi

    2012-04-01

    Full Text Available The authors report the case of a female infant with Group III (or Grade III megaesophagus secondary to vector-borne Chagas disease, resulting in severe malnutrition that reversed after surgery (Heller technique. The infant was then treated with the antiparasitic drug benznidazole, and the infection was cured, as demonstrated serologically and parasitologically. After follow-up of several years without evidence of disease, with satisfactory weight and height development, the patient had her first child at age 23, in whom serological tests for Chagas disease yielded negative results. Thirty years after the initial examination, the patient's electrocardiogram, echocardiogram, and chest radiography remained normal.

  9. Indirect versus direct feedback in computer-based Prism Adaptation Therapy

    DEFF Research Database (Denmark)

    Wilms, Inge Linda; Rytter, Hana Malá

    2010-01-01

    Prism Adaptation Therapy (PAT) is an intervention method in the treatment of the attention disorder neglect (Frassinetti, Angeli, Meneghello, Avanzi, & Ladavas, 2002; Rossetti, et al., 1998). The aim of this study was to investigate whether one session of PAT using a computer-attached touchscreen...... in the aftereffect. The findings have direct implications for future implementations of computer-based methods of treatment of visuospatial disorders and computer-assisted rehabilitation in general....

  10.   Indirect versus direct feedback in computer-based Prism Adaptation Therapy

    DEFF Research Database (Denmark)

    Wilms, Inge Linda; Rytter, Hana Malá

    2010-01-01

      Prism Adaptation Therapy (PAT) is an intervention method in the treatment of the attention disorder neglect (Frassinetti, Angeli, Meneghello, Avanzi, & Ladavas, 2002; Rossetti, et al., 1998). The aim of this study was to investigate whether one session of PAT using a computer-attached touchscreen...... have direct implications for future implementations of computer-based methods of treatment of visuospatial disorders and computer-assisted rehabilitation in general....

  11. HEATING OF BLANK IN FORM OF PRISM IN ACCORDANCE WITH TECHNOLOGICAL LIMITATIONS

    Directory of Open Access Journals (Sweden)

    V. B. Kovalevsky

    2009-01-01

    Full Text Available The paper considers a problem on optimum heating control of a blank in the form of prism under complicated conditions of heat-transfer in accordance with criteria of gas consumption minimization, decarburized layer and scaling. Numerical algorithm of the problem solution and examples are given in the paper. A new technology of the flame furnace operation has been developed in the paper. 

  12. Bisecting real and fake body parts: effects of prism adaptation after right brain damage

    Directory of Open Access Journals (Sweden)

    Nadia eBolognini

    2012-06-01

    Full Text Available The representation of body parts holds a special status in the brain, due to their prototypical shape and the contribution of multisensory (visual and somatosensory-proprioceptive information. In a previous study (Sposito et al., 2010, we showed that patients with left unilateral spatial neglect exhibit a rightward bias in setting the mid-point of their left forearm, which becomes larger when bisecting a cylindrical object comparable in size. This body part advantage, found also in control participants, suggests partly different processes for computing the extent of body parts and objects. In this study we tested 16 right-brain-damaged patients, and 10 unimpaired participants, on a manual bisection task of their own (real left forearm, or a size-matched fake forearm. We then explored the effects of adaptation to rightward displacing prism exposure, which brings about leftward aftereffects. We found that all participants showed prism adaptation and aftereffects, with right-brain-damaged patients exhibiting a reduction of the rightward bias for both real and fake forearm, with no overall differences between them. Second, correlation analyses highlighted the role of visual and proprioceptive information for the metrics of body parts. Third, single-patient analyses showed dissociations between real and fake forearm bisections, and the effects of prism adaptation, as well as a more frequent impairment with fake body parts. In sum, the rightward bias shown by right-brain-damaged patients in bisecting body parts is reduced by prism exposure, as other components of the neglect syndrome; discrete spatial representations for real and fake body parts, for which visual and proprioceptive codes play different roles, are likely to exist. Multisensory information seems to render self bodily segments more resistant to the disruption brought about by right-hemisphere injury.

  13. PRISM [Power Reactor Inherently Safe Module] design concept enhances waste management

    International Nuclear Information System (INIS)

    Thompson, M.L.; Berglund, R.C.

    1989-01-01

    PRISM, a modular advanced liquid metal reactor (ALMR), has been designed conceptually by GE under the US Department of Energy sponsorship. The concept design and analyses have been primarily focused on passive safety and improved construction and operating costs. Significantly, the unique design of multiple modules and features of PRISM enhance waste management over conventional reactor systems. This paper provides an overview of PRISM of these enhancements. Inherent to the ALMR's, the sodium coolant precludes crud buildup on reactor surfaces and in components and waste for disposal. Preliminary evaluations indicate this fundamental feature results in factors of 2-4 less waste volume and 2-3 orders of magnitude less curies per megawatt-electric for ultimate disposal. For example, the tap designed for sodium cleanup is expected to be exchanged only once every thirty years. Also, inherent to ALMR's, burning waste actinides and selected fission products to preclude their accumulation and burial is very attractive. The hard neutron spectrum of ALMR burns the actinides efficiently and is not poisoned by the actinides and fission products. The modular design of PRISM components (and the fuel cycle equipment) permit replacement without expensive and potentially hazardous volume reduction. For example, the functional components of the reference electromagnetic pump and IHK can be removed intact for waste disposal. Although development of the reference metal fuel is not completed, it is estimated that (low-level) waste from recycle of the fuel will result in significantly less volume than would be generated by aqueous recycle of oxide fuel. 6 refs., 10 figs

  14. Analysis of postulated events for the revised ALMR/PRISM design

    International Nuclear Information System (INIS)

    Slovik, G.C.; Van Tuyle, G.J.

    1991-01-01

    The PRISM reactor is presently under pre-application licensing review by the NRC, with Brookhaven National Laboratory (BNL) providing technical assistance. In this paper, the authors describe the latest set of results from their SSC and MINET code calculations. Series of postulated events were analyzed, for the most current PRISM design, to evaluate the system performance under unscrammed conditions. The PRISM reactor utilizes a metal fuel composed of 27% Pu, 10% Zr, and 63% U, based on the fuel developed by Argonne National Laboratory as part of the Integral Fast Reactor program. The fuel has a small power and temperature defect as a result of the high fuel thermal conductivity of metal and a hard neutron spectrum. The reactivity feedbacks of the core are designed to provide a negative response to off-normal, high temperature conditions, by invoking negative responses from the thermal expansion of the fuel, control rods, and core radial dimensions. The core restraint system incorporates the limited free bowing feature, which generates an outward bow of the in-core portion of the fuel assembly when a temperature gradient exits. The core also has three Gas Expansion Modules (GEMs) placed around the periphery, which will remove a combined worth of -69 cents of reactivity when the pumps are tripped from full power conditions. In evaluating this passive shutdown response, in which the PRISM reactor power should decrease significantly in response to overheated conditions, one considers three classes of unscrammed events. These include the unscrammed loss of flow (ULOF), loss of heat sink (ULOHS), and transient over power (UTOP) events

  15. Radiometric, geometric, and image quality assessment of ALOS AVNIR-2 and PRISM sensors

    Science.gov (United States)

    Saunier, S.; Goryl, P.; Chander, G.; Santer, R.; Bouvet, M.; Collet, B.; Mambimba, A.; Kocaman, Aksakal S.

    2010-01-01

    The Advanced Land Observing Satellite (ALOS) was launched on January 24, 2006, by a Japan Aerospace Exploration Agency (JAXA) H-IIA launcher. It carries three remote-sensing sensors: 1) the Advanced Visible and Near-Infrared Radiometer type 2 (AVNIR-2); 2) the Panchromatic Remote-Sensing Instrument for Stereo Mapping (PRISM); and 3) the Phased-Array type L-band Synthetic Aperture Radar (PALSAR). Within the framework of ALOS Data European Node, as part of the European Space Agency (ESA), the European Space Research Institute worked alongside JAXA to provide contributions to the ALOS commissioning phase plan. This paper summarizes the strategy that was adopted by ESA to define and implement a data verification plan for missions operated by external agencies; these missions are classified by the ESA as third-party missions. The ESA was supported in the design and execution of this plan by GAEL Consultant. The verification of ALOS optical data from PRISM and AVNIR-2 sensors was initiated 4 months after satellite launch, and a team of principal investigators assembled to provide technical expertise. This paper includes a description of the verification plan and summarizes the methodologies that were used for radiometric, geometric, and image quality assessment. The successful completion of the commissioning phase has led to the sensors being declared fit for operations. The consolidated measurements indicate that the radiometric calibration of the AVNIR-2 sensor is stable and agrees with the Landsat-7 Enhanced Thematic Mapper Plus and the Envisat MEdium-Resolution Imaging Spectrometer calibration. The geometrical accuracy of PRISM and AVNIR-2 products improved significantly and remains under control. The PRISM modulation transfer function is monitored for improved characterization.

  16. Role of Prism Decussation on Fatigue Crack Growth and Fracture of Human Enamel

    OpenAIRE

    Bajaj, Devendra; Arola, Dwayne

    2009-01-01

    The role of prism decussation on the crack growth resistance of human enamel is evaluated. Miniature inset Compact Tension (CT) specimens embodying a section of cuspal enamel were subjected to Mode I cyclic or monotonic loads. Cracks were grown in either the forward (from outer enamel inwards) or reverse (from inner enamel outwards) direction and the responses were compared quantitatively. Results showed that the outer enamel exhibits lower resistance to the inception and growth of cracks. Re...

  17. Cultivation-independent methods reveal differences among bacterial gut microbiota in triatomine vectors of Chagas disease.

    Directory of Open Access Journals (Sweden)

    Fabio Faria da Mota

    Full Text Available BACKGROUND: Chagas disease is a trypanosomiasis whose agent is the protozoan parasite Trypanosoma cruzi, which is transmitted to humans by hematophagous bugs known as triatomines. Even though insecticide treatments allow effective control of these bugs in most Latin American countries where Chagas disease is endemic, the disease still affects a large proportion of the population of South America. The features of the disease in humans have been extensively studied, and the genome of the parasite has been sequenced, but no effective drug is yet available to treat Chagas disease. The digestive tract of the insect vectors in which T. cruzi develops has been much less well investigated than blood from its human hosts and constitutes a dynamic environment with very different conditions. Thus, we investigated the composition of the predominant bacterial species of the microbiota in insect vectors from Rhodnius, Triatoma, Panstrongylus and Dipetalogaster genera. METHODOLOGY/PRINCIPAL FINDINGS: Microbiota of triatomine guts were investigated using cultivation-independent methods, i.e., phylogenetic analysis of 16s rDNA using denaturing gradient gel electrophoresis (DGGE and cloned-based sequencing. The Chao index showed that the diversity of bacterial species in triatomine guts is low, comprising fewer than 20 predominant species, and that these species vary between insect species. The analyses showed that Serratia predominates in Rhodnius, Arsenophonus predominates in Triatoma and Panstrongylus, while Candidatus Rohrkolberia predominates in Dipetalogaster. CONCLUSIONS/SIGNIFICANCE: The microbiota of triatomine guts represents one of the factors that may interfere with T. cruzi transmission and virulence in humans. The knowledge of its composition according to insect species is important for designing measures of biological control for T. cruzi. We found that the predominant species of the bacterial microbiota in triatomines form a group of low

  18. Chagas disease: national survey of seroprevalence in children under five years of age conducted in 2008.

    Science.gov (United States)

    Russomando, Graciela; Cousiño, Blanca; Sanchez, Zunilda; Franco, Laura X; Nara, Eva M; Chena, Lilian; Martínez, Magaly; Galeano, María E; Benitez, Lucio

    2017-05-01

    Since the early 1990s, programs to control Chagas disease in South America have focused on eradicating domiciliary Triatoma infestans, the main vector. Seroprevalence studies of the chagasic infection are included as part of the vector control programs; they are essential to assess the impact of vector control measures and to monitor the prevention of vector transmission. To assess the interruption of domiciliary vector transmission of Chagas disease by T. infestans in Paraguay by evaluating the current state of transmission in rural areas. A survey of seroprevalence of Chagas disease was carried out in a representative sample group of Paraguayans aged one to five years living in rural areas of Paraguay in 2008. Blood samples collected on filter paper from 12,776 children were tested using an enzyme-linked immunosorbent assay. Children whose serology was positive or undetermined (n = 41) were recalled to donate a whole blood sample for retesting. Their homes were inspected for current triatomine infestation. Blood samples from their respective mothers were also collected and tested to check possible transmission of the disease by a congenital route. A seroprevalence rate of 0.24% for Trypanosoma cruzi infection was detected in children under five years of age among the country's rural population. Our findings indicate that T. cruzi was transmitted to these children vertically. The total number of infected children, aged one to five years living in these departments, was estimated at 1,691 cases with an annual incidence of congenital transmission of 338 cases per year. We determined the impact of vector control in the transmission of T. cruzi, following uninterrupted vector control measures employed since 1999 in contiguous T. infestans-endemic areas of Paraguay, and this allowed us to estimate the degree of risk of congenital transmission in the country.

  19. Suicide risk and alcohol and drug abuse in outpatients with HIV infection and Chagas disease.

    Science.gov (United States)

    Guimarães, Patrícia M; Passos, Sonia R; Calvet, Guilherme A; Hökerberg, Yara H; Lessa, José L; Andrade, Carlos A de

    2014-01-01

    To evaluate psychiatric comorbidities in outpatients receiving care for HIV and Chagas disease at Instituto de Pesquisa Clínica Evandro Chagas (IPEC), Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil. Cross-sectional study with a consecutive sample of 125 patients referred to an outpatient psychiatric clinic from February to December 2010. The Mini International Neuropsychiatric Interview (MINI) was used. Factors associated with more frequent mental disorders were estimated by odds ratios (OR) with 95% confidence intervals (95%CI) by multiple logistic regression. Seventy-six (60.8%) patients with HIV, 40 (32%) patients with Chagas disease, and nine (7.2%) patients with human T-lymphotropic virus were interviewed. The majority were women (64%), with up to 8 years of formal education (56%), and unemployed (81.6%). The median age was 49 years. Suicide risk (n=71) (56%), agoraphobia (n=65) (52%), major depressive episode (n=56) (44.8%), and alcohol/drug abuse (n=43) (34.4%) predominated, the latter being directly associated with lower family income (OR = 2.64; 95%CI 1.03-6.75) and HIV infection (OR = 5.24; 95%CI 1.56-17.61). Suicide risk was associated with non-white skin color (OR = 2.21; 95%CI 1.03-4.75), unemployment (OR = 2.72; 95%CI 1.01-7.34), and diagnosis of major depression (OR = 3.34; 95%CI 1.54-7.44). Measures targeting adverse socioeconomic conditions and psychiatric and psychological monitoring and care should be encouraged in this population, considering the association with abuse of alcohol/other psychoactive drugs and suicide risk.

  20. Suicide risk and alcohol and drug abuse in outpatients with HIV infection and Chagas disease

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    Patrícia M. Guimarães

    2014-05-01

    Full Text Available Objective: To evaluate psychiatric comorbidities in outpatients receiving care for HIV and Chagas disease at Instituto de Pesquisa Clínica Evandro Chagas (IPEC, Fundação Oswaldo Cruz (Fiocruz, Rio de Janeiro, Brazil. Methods: Cross-sectional study with a consecutive sample of 125 patients referred to an outpatient psychiatric clinic from February to December 2010. The Mini International Neuropsychiatric Interview (MINI was used. Factors associated with more frequent mental disorders were estimated by odds ratios (OR with 95% confidence intervals (95%CI by multiple logistic regression. Results: Seventy-six (60.8% patients with HIV, 40 (32% patients with Chagas disease, and nine (7.2% patients with human T-lymphotropic virus were interviewed. The majority were women (64%, with up to 8 years of formal education (56%, and unemployed (81.6%. The median age was 49 years. Suicide risk (n=71 (56%, agoraphobia (n=65 (52%, major depressive episode (n=56 (44.8%, and alcohol/drug abuse (n=43 (34.4% predominated, the latter being directly associated with lower family income (OR = 2.64; 95%CI 1.03-6.75 and HIV infection (OR = 5.24; 95%CI 1.56-17.61. Suicide risk was associated with non-white skin color (OR = 2.21; 95%CI 1.03-4.75, unemployment (OR = 2.72; 95%CI 1.01-7.34, and diagnosis of major depression (OR = 3.34; 95%CI 1.54-7.44. Conclusion: Measures targeting adverse socioeconomic conditions and psychiatric and psychological monitoring and care should be encouraged in this population, considering the association with abuse of alcohol/other psychoactive drugs and suicide risk.

  1. II Consenso Brasileiro em Doença de Chagas, 2015

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    João Carlos Pinto Dias

    Full Text Available RESUMO A doença de Chagas é uma condição crônica negligenciada com elevada carga de morbimortalidade e impacto dos pontos de vista psicológico, social e econômico. Representa um importante problema de saúde pública no Brasil, com diferentes cenários regionais. Este documento traduz a sistematização das evidências que compõe o Consenso Brasileiro de Doença de Chagas. O objetivo foi sistematizar estratégias de diagnóstico, tratamento, prevenção e controle da doença de Chagas no país, de modo a refletir as evidências científicas disponíveis. Sua construção fundamentou-se na articulação e contribuição estratégica de especialistas brasileiros com conhecimento, experiência e atualização sobre diferentes aspectos da doença. Representa o resultado da estreita colaboração entre a Sociedade Brasileira de Medicina Tropical e o Ministério da Saúde. Espera-se com este documento fortalecer o desenvolvimento de ações integradas para enfrentamento da doença no país com foco em epidemiologia, gestão, atenção integral (incluindo famílias e comunidades, comunicação, informação, educação e pesquisas.

  2. Relationship between Fibrosis and Ventricular Arrhythmias in Chagas Heart Disease Without Ventricular Dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Tassi, Eduardo Marinho, E-mail: etassi@ibest.com.br [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Continentino, Marcelo Abramoff [Hospital Frei Galvão, Guaratinguetá, SP (Brazil); Nascimento, Emília Matos do; Pereira, Basílio de Bragança [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Coppe - Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia - UFRJ, Rio de Janeiro, RJ (Brazil); Pedrosa, Roberto Coury [Instituto de Cardiologia Edson Saad - Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2014-05-15

    Patients with Chagas disease and segmental wall motion abnormality (SWMA) have worse prognosis independent of left ventricular ejection fraction (LVEF). Cardiac magnetic resonance (CMR) is currently the best method to detect SWMA and to assess fibrosis. To quantify fibrosis by using late gadolinium enhancement CMR in patients with Chagas disease and preserved or minimally impaired ventricular function (> 45%), and to detect patterns of dependence between fibrosis, SWMA and LVEF in the presence of ventricular arrhythmia. Electrocardiogram, treadmill exercise test, Holter and CMR were carried out in 61 patients, who were divided into three groups as follows: (1) normal electrocardiogram and CMR without SWMA; (2) abnormal electrocardiogram and CMR without SWMA; (3) CMR with SWMA independently of electrocardiogram. The number of patients with ventricular arrhythmia in relation to the total of patients, the percentage of fibrosis, and the LVEF were, respectively: Group 1, 4/26, 0.74% and 74.34%; Group 2, 4/16, 3.96% and 68.5%; and Group 3, 11/19, 14.07% and 55.59%. Ventricular arrhythmia was found in 31.1% of the patients. Those with and without ventricular arrhythmia had mean LVEF of 59.87% and 70.18%, respectively, and fibrosis percentage of 11.03% and 3.01%, respectively. Of the variables SWMA, groups, age, LVEF and fibrosis, only the latter was significant for the presence of ventricular arrhythmia, with a cutoff point of 11.78% for fibrosis mass (p < 0.001). Even in patients with Chagas disease and preserved or minimally impaired ventricular function, electrical instability can be present. Regarding the presence of ventricular arrhythmia, fibrosis is the most important variable, its amount being proportional to the complexity of the groups.

  3. Relationship between Fibrosis and Ventricular Arrhythmias in Chagas Heart Disease Without Ventricular Dysfunction

    International Nuclear Information System (INIS)

    Tassi, Eduardo Marinho; Continentino, Marcelo Abramoff; Nascimento, Emília Matos do; Pereira, Basílio de Bragança; Pedrosa, Roberto Coury

    2014-01-01

    Patients with Chagas disease and segmental wall motion abnormality (SWMA) have worse prognosis independent of left ventricular ejection fraction (LVEF). Cardiac magnetic resonance (CMR) is currently the best method to detect SWMA and to assess fibrosis. To quantify fibrosis by using late gadolinium enhancement CMR in patients with Chagas disease and preserved or minimally impaired ventricular function (> 45%), and to detect patterns of dependence between fibrosis, SWMA and LVEF in the presence of ventricular arrhythmia. Electrocardiogram, treadmill exercise test, Holter and CMR were carried out in 61 patients, who were divided into three groups as follows: (1) normal electrocardiogram and CMR without SWMA; (2) abnormal electrocardiogram and CMR without SWMA; (3) CMR with SWMA independently of electrocardiogram. The number of patients with ventricular arrhythmia in relation to the total of patients, the percentage of fibrosis, and the LVEF were, respectively: Group 1, 4/26, 0.74% and 74.34%; Group 2, 4/16, 3.96% and 68.5%; and Group 3, 11/19, 14.07% and 55.59%. Ventricular arrhythmia was found in 31.1% of the patients. Those with and without ventricular arrhythmia had mean LVEF of 59.87% and 70.18%, respectively, and fibrosis percentage of 11.03% and 3.01%, respectively. Of the variables SWMA, groups, age, LVEF and fibrosis, only the latter was significant for the presence of ventricular arrhythmia, with a cutoff point of 11.78% for fibrosis mass (p < 0.001). Even in patients with Chagas disease and preserved or minimally impaired ventricular function, electrical instability can be present. Regarding the presence of ventricular arrhythmia, fibrosis is the most important variable, its amount being proportional to the complexity of the groups

  4. Utilizing Chemical Genomics to Identify Cytochrome b as a Novel Drug Target for Chagas Disease.

    Directory of Open Access Journals (Sweden)

    Shilpi Khare

    2015-07-01

    Full Text Available Unbiased phenotypic screens enable identification of small molecules that inhibit pathogen growth by unanticipated mechanisms. These small molecules can be used as starting points for drug discovery programs that target such mechanisms. A major challenge of the approach is the identification of the cellular targets. Here we report GNF7686, a small molecule inhibitor of Trypanosoma cruzi, the causative agent of Chagas disease, and identification of cytochrome b as its target. Following discovery of GNF7686 in a parasite growth inhibition high throughput screen, we were able to evolve a GNF7686-resistant culture of T. cruzi epimastigotes. Clones from this culture bore a mutation coding for a substitution of leucine by phenylalanine at amino acid position 197 in cytochrome b. Cytochrome b is a component of complex III (cytochrome bc1 in the mitochondrial electron transport chain and catalyzes the transfer of electrons from ubiquinol to cytochrome c by a mechanism that utilizes two distinct catalytic sites, QN and QP. The L197F mutation is located in the QN site and confers resistance to GNF7686 in both parasite cell growth and biochemical cytochrome b assays. Additionally, the mutant cytochrome b confers resistance to antimycin A, another QN site inhibitor, but not to strobilurin or myxothiazol, which target the QP site. GNF7686 represents a promising starting point for Chagas disease drug discovery as it potently inhibits growth of intracellular T. cruzi amastigotes with a half maximal effective concentration (EC50 of 0.15 µM, and is highly specific for T. cruzi cytochrome b. No effect on the mammalian respiratory chain or mammalian cell proliferation was observed with up to 25 µM of GNF7686. Our approach, which combines T. cruzi chemical genetics with biochemical target validation, can be broadly applied to the discovery of additional novel drug targets and drug leads for Chagas disease.

  5. Polymorphisms in the gene for lymphotoxin-alpha predispose to chronic Chagas cardiomyopathy.

    Science.gov (United States)

    Ramasawmy, Rajendranath; Fae, Kellen C; Cunha-Neto, Edecio; Müller, Natalie G; Cavalcanti, Vanessa L; Ferreira, Renata C; Drigo, Sandra A; Ianni, Barbara; Mady, Charles; Goldberg, Anna C; Kalil, Jorge

    2007-12-15

    Chagas disease, caused by Trypanosoma cruzi infection, displays clinical heterogeneity and may be attributable to differential genetic susceptibility. Chronic Chagas cardiomyopathy (CCC) develops only in a subset of T. cruzi-infected individuals and may lead to heart failure that has a worse clinical course and that leads to reduced life expectancy, compared with heart failure of other etiologies. Proinflammatory cytokines play a key role in the development of CCC. Clinical, genetic, and epidemiological studies have linked lymphotoxin-alpha (LTA), a proinflammatory cytokine, to coronary artery disease and myocardial infarction. We used polymerase chain reaction to genotype the LTA +80A-->C and LTA +252A-->G variants in 169 patients with CCC and in 76 T. cruzi-infected asymptomatic (ASY) patients. Homozygosity with respect to the LTA +80C and LTA +252G alleles was significantly more frequent in the patients with CCC than in the ASY patients (homozygosity for LTA +80C, 47% vs. 33%; homozygosity for LTA +252G, 16% vs. 8%). Haplotype LTA +80A-252A was associated with protection against CCC, whereas haplotype LTA +80C-252G was associated with susceptibility to CCC. Furthermore, homozygosity for the LTA +80A allele correlated with the lowest levels of plasmatic tumor-necrosis factor-alpha. Our results suggest that the study of genetic variations in patients with Chagas disease may help in the identification of individuals at increased risk of progressing to CCC and, by providing early treatment, reduce the morbidity and mortality associated with this disease.

  6. Estudo longitudinal do eletrocardiograma na doença de Chagas desde a fase aguda

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    Roberto C. Pedrosa

    1993-09-01

    Full Text Available Vários trabalhos com eletrocardiograma na doença de Chagas têm sido feitos. Alguns referindo-se a grupos selecionados de casos, outros a estudos longitudinais, relatam as características da mortalidade nas diversas fases da doença. Com o objetivo de avaliar o valor do eletrocardiograma como índice de avaliação terapêutica e de seu comportamento na doença de Chagas desde a fase aguda, no presente trabalho, analisou-se evolutivamente o eletrocardiograma de 42 pacientes (18 mulheres e 24 homens procedentes da zona rural do Norte de Minas Gerais; predomínio etário foi nas duas primeiras décadas; todos com comprometimento cardíaco; todos receberam tratamento específico. O acompanhamento dos 42 pacientes foi de 9 anos dos quais 3 pacientes tiveram seguimento de 20 anos. Foram analisados 270 eletrocardiogramas. Nós utilizamos os seguintes critérios para a análise do ECG: código de Minnesota modificado para doença de Chagas; WHO/I. S. F. C. TASK FORCE para condução intraventricular e critérios de Pieretti para área eletricamente inativa. Concluímos que as alterações eletrocardiográficas agravam com a evolução da doença e que o eletrocardiograma não serve de índice de avaliação terapêutica.

  7. Cultivation-independent methods reveal differences among bacterial gut microbiota in triatomine vectors of Chagas disease.

    Science.gov (United States)

    da Mota, Fabio Faria; Marinho, Lourena Pinheiro; Moreira, Carlos José de Carvalho; Lima, Marli Maria; Mello, Cícero Brasileiro; Garcia, Eloi Souza; Carels, Nicolas; Azambuja, Patricia

    2012-01-01

    Chagas disease is a trypanosomiasis whose agent is the protozoan parasite Trypanosoma cruzi, which is transmitted to humans by hematophagous bugs known as triatomines. Even though insecticide treatments allow effective control of these bugs in most Latin American countries where Chagas disease is endemic, the disease still affects a large proportion of the population of South America. The features of the disease in humans have been extensively studied, and the genome of the parasite has been sequenced, but no effective drug is yet available to treat Chagas disease. The digestive tract of the insect vectors in which T. cruzi develops has been much less well investigated than blood from its human hosts and constitutes a dynamic environment with very different conditions. Thus, we investigated the composition of the predominant bacterial species of the microbiota in insect vectors from Rhodnius, Triatoma, Panstrongylus and Dipetalogaster genera. Microbiota of triatomine guts were investigated using cultivation-independent methods, i.e., phylogenetic analysis of 16s rDNA using denaturing gradient gel electrophoresis (DGGE) and cloned-based sequencing. The Chao index showed that the diversity of bacterial species in triatomine guts is low, comprising fewer than 20 predominant species, and that these species vary between insect species. The analyses showed that Serratia predominates in Rhodnius, Arsenophonus predominates in Triatoma and Panstrongylus, while Candidatus Rohrkolberia predominates in Dipetalogaster. The microbiota of triatomine guts represents one of the factors that may interfere with T. cruzi transmission and virulence in humans. The knowledge of its composition according to insect species is important for designing measures of biological control for T. cruzi. We found that the predominant species of the bacterial microbiota in triatomines form a group of low complexity whose structure differs according to the vector genus.

  8. Chagas disease: national survey of seroprevalence in children under five years of age conducted in 2008

    Directory of Open Access Journals (Sweden)

    Graciela Russomando

    Full Text Available BACKGROUND Since the early 1990s, programs to control Chagas disease in South America have focused on eradicating domiciliary Triatoma infestans, the main vector. Seroprevalence studies of the chagasic infection are included as part of the vector control programs; they are essential to assess the impact of vector control measures and to monitor the prevention of vector transmission. OBJECTIVE To assess the interruption of domiciliary vector transmission of Chagas disease by T. infestans in Paraguay by evaluating the current state of transmission in rural areas. METHODS A survey of seroprevalence of Chagas disease was carried out in a representative sample group of Paraguayans aged one to five years living in rural areas of Paraguay in 2008. Blood samples collected on filter paper from 12,776 children were tested using an enzyme-linked immunosorbent assay. Children whose serology was positive or undetermined (n = 41 were recalled to donate a whole blood sample for retesting. Their homes were inspected for current triatomine infestation. Blood samples from their respective mothers were also collected and tested to check possible transmission of the disease by a congenital route. FINDINGS A seroprevalence rate of 0.24% for Trypanosoma cruzi infection was detected in children under five years of age among the country’s rural population. Our findings indicate that T. cruzi was transmitted to these children vertically. The total number of infected children, aged one to five years living in these departments, was estimated at 1,691 cases with an annual incidence of congenital transmission of 338 cases per year. MAIN CONCLUSION We determined the impact of vector control in the transmission of T. cruzi, following uninterrupted vector control measures employed since 1999 in contiguous T. infestans-endemic areas of Paraguay, and this allowed us to estimate the degree of risk of congenital transmission in the country.

  9. A Concentrator Photovoltaic System Based on a Combination of Prism-Compound Parabolic Concentrators

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    Ngoc Hai Vu

    2016-08-01

    Full Text Available We present a cost-effective concentrating photovoltaic system composed of a prism and a compound parabolic concentrator (P-CPC. In this approach, the primary collector consists of a prism, a solid compound parabolic concentrator (CPC, and a slab waveguide. The prism, which is placed on the input aperture of CPC, directs the incoming sunlight beam to be parallel with the main axes of parabolic rims of CPC. Then, the sunlight is reflected at the parabolic rims and concentrated at the focal point of these parabolas. A slab waveguide is coupled at the output aperture of the CPC to collect focused sunlight beams and to guide them to the solar cell. The optical system was modeled and simulated with commercial ray tracing software (LightTools™. Simulation results show that the optical efficiency of a P-CPC can achieve up to 89%. when the concentration ratio of the P-CPC is fixed at 50. We also determine an optimal geometric structure of P-CPC based on simulation. Because of the simplicity of the P-CPC structure, a lower-cost mass production process is possible. A simulation based on optimal structure of P-CPC was performed and the results also shown that P-CPC has high angular tolerance for input sunlight. The high tolerance of the input angle of sunlight allows P-CPC solar concentrator utilize a single sun tracking system instead of a highly precise dual suntracking system as cost effective solution.

  10. Fluid expulsion sites on the Cascadia accretionary prism: mapping diagenetic deposits with processed GLORIA imagery

    Science.gov (United States)

    Carson, Bobb; Seke, Erol; Paskevich, Valerie F.; Holmes, Mark L.

    1994-01-01

    Point-discharge fluid expulsion on accretionary prisms is commonly indicated by diagenetic deposition of calcium carbonate cements and gas hydrates in near-surface (topographic and lithologic information. We have processed GLORIA imagery from the Oregon continental margin to remove topographic effects. A synthetic side scan image was created initially from Sea Beam bathymetric data and then was subtracted iteratively from the original GLORIA data until topographic features disappeared. The residual image contains high-amplitude backscattering that we attribute to diagenetic deposits associated with fluid discharge, based on submersible mapping, Ocean Drilling Program drilling, and collected samples. Diagenetic deposits are concentrated (1) near an out-of-sequence thrust fault on the second ridge landward of the base of the continental slope, (2) along zones characterized by deep-seated strikeslip faults that cut transversely across the margin, and (3) in undeformed Cascadia Basin deposits which overlie incipient thrust faults seaward of the toe of the prism. There is no evidence of diagenetic deposition associated with the frontal thrust that rises from the dècollement. If the dècollement is an important aquifer, apparently the fluids are passed either to the strike-slip faults which intersect the dècollement or to the incipient faults in Cascadia Basin for expulsion. Diagenetic deposits seaward of the prism toe probably consist dominantly of gas hydrates.

  11. Use of the Tax Prism Method When Forming Tax Part of the Budget

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    Verovska Ludmila

    2017-06-01

    Full Text Available The tax prism method is developed for the assessment of tax part of the budget as well as for forecasting the influence of tax optimisation on it. There are certain trends in global practice. Developing and transition economies are characterised by low tax burden. Economically developed countries with a high level of social security of population are characterised by high tax burden. The analytical and graphic-analytical research for the purpose of determination of optimum size of the taxation using the tax prism has been conducted. In addition to the concept of ‘tax prism’, concepts such as static and dynamic tax prisms have been introduced, allowing to consider changes in the part of the budget of interest in connection with a possibility of taxation subjects to reduce the size of a tax burden by various methods of tax optimisation, and also to consider the influence of other factors on it. The use of this approach helps effectively to enhance the tax legislation by modelling high-quality and quantitative consequences of one or another changes and innovations.

  12. The PRISM reactor as a possible option to deal with the british civilian plutonium stockpile

    Energy Technology Data Exchange (ETDEWEB)

    Fichtlscherer, Christopher [IANUS, TU Darmstadt (Germany); Friess, Friederike [IANUS, TU Darmstadt (Germany); ISR, Universitaet fuer Bodenkultur Wien (Boku) (Austria)

    2017-07-01

    Dealing with stocks of separated weapon-usable plutonium is a big challenge for our modern society. This work focuses on the British civil plutonium stockpiles, which amount to 103.3 tons. One option is seen in irradiating the plutonium in a fast reactor under development, namely the GE PRISM reactor. The PRISM reactor is a small modular, fast reactor which has a thermal power of 840 MW and an electrical output of 311 MW. It is intended to use MOX fuel and proponents claim, that it thus would be possible to produce clean energy, while making the plutonium proliferation resistant. A MCNP model of the reactor is built and depletion calculations with different target burnups of the fuel were conducted to check whether the burned material would fulfil the Spent-Fuel Standard. Particularly it was checked whether the spent fuel is self protecting, meaning that the dose rate does not fall below a limit of 1 Sv/h in 1 meter distance after a cooling period of 30 years. Based on the reactor model calculations the irradiation time to fulfill this limit for the spent fuel is calculated. Based on the needed target burnup, it can be verified, whether it is possible for the PRISM reactor to render the civil plutonium proliferation resistant in only 20 years as is is claimed by its proponents.

  13. The PRISM concept for a safe, economic and testable liquid metal fast reactor plant

    International Nuclear Information System (INIS)

    Berglund, R.C.; Salerno, L.N.; Tippets, F.E.

    1987-01-01

    The PRISM project is underway at General Electric as part of an advanced reactor conceptual design program sponsored by the US Department of Energy. The PRISM concept emphasizes inherent safety, modular construction, and factory fabrication. These features are intended to improve the basis for public acceptance, reduce cost,improve licensability, and reduce the risk of schedule delays and cost increases during construction. A PRISM power plant comprises a number of reactor modules. The relatively small size of the reactor module facilitates the use of passive, inherent self-shutdown and shutdown heat removal features for safe accommodation of accidents. These inherent safety features permit simplification and reduction of conventional safety-related systems in the plant. Testing of a full-size prototype reactor module is planned in the late 1990's to demonstrate these inherent safety characteristics. It is intended that the results of the test be used to obtain certification of the design by the US Nuclear Regulatory Commission preparatory to use of reactor modules built to this standard design in licensed commercial plants

  14. Diamond-coated ATR prism for infrared absorption spectroscopy of surface-modified diamond nanoparticles

    Science.gov (United States)

    Remes, Z.; Kozak, H.; Rezek, B.; Ukraintsev, E.; Babchenko, O.; Kromka, A.; Girard, H. A.; Arnault, J.-C.; Bergonzo, P.

    2013-04-01

    Linear antenna microwave chemical vapor deposition process was used to homogeneously coat a 7 cm long silicon prism by 85 nm thin nanocrystalline diamond (NCD) layer. To show the advantages of the NCD-coated prism for attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) of nanoparticles, we apply diamond nanoparticles (DNPs) of 5 nm nominal size with various surface modifications by a drop-casting of their methanol dispersions. ATR-FTIR spectra of as-received, air-annealed, plasma-oxidized, and plasma-hydrogenated DNPs were measured in the 4000-1500 cm-1 spectral range. The spectra show high spectral resolution, high sensitivity to specific DNP surface moieties, and repeatability. The NCD coating provides mechanical protection against scratching and chemical stability of the surface. Moreover, unlike on bare Si surface, NCD hydrophilic properties enable optically homogeneous coverage by DNPs with some aggregation on submicron scale as evidenced by scanning electron microscopy and atomic force microscopy. Compared to transmission FTIR regime with KBr pellets, direct and uniform deposition of DNPs on NCD-ATR prism significantly simplifies and speeds up the analysis (from days to minutes). We discuss prospects for in situ monitoring of surface modifications and molecular grafting.

  15. Neural mechanisms underlying spatial realignment during adaptation to optical wedge prisms.

    Science.gov (United States)

    Chapman, Heidi L; Eramudugolla, Ranmalee; Gavrilescu, Maria; Strudwick, Mark W; Loftus, Andrea; Cunnington, Ross; Mattingley, Jason B

    2010-07-01

    Visuomotor adaptation to a shift in visual input produced by prismatic lenses is an example of dynamic sensory-motor plasticity within the brain. Prism adaptation is readily induced in healthy individuals, and is thought to reflect the brain's ability to compensate for drifts in spatial calibration between different sensory systems. The neural correlate of this form of functional plasticity is largely unknown, although current models predict the involvement of parieto-cerebellar circuits. Recent studies that have employed event-related functional magnetic resonance imaging (fMRI) to identify brain regions associated with prism adaptation have discovered patterns of parietal and cerebellar modulation as participants corrected their visuomotor errors during the early part of adaptation. However, the role of these regions in the later stage of adaptation, when 'spatial realignment' or true adaptation is predicted to occur, remains unclear. Here, we used fMRI to quantify the distinctive patterns of parieto-cerebellar activity as visuomotor adaptation develops. We directly contrasted activation patterns during the initial error correction phase of visuomotor adaptation with that during the later spatial realignment phase, and found significant recruitment of the parieto-cerebellar network--with activations in the right inferior parietal lobe and the right posterior cerebellum. These findings provide the first evidence of both cerebellar and parietal involvement during the spatial realignment phase of prism adaptation. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  16. Possibilities of magnet prism β-spectrometer application in on-line experiments

    International Nuclear Information System (INIS)

    Akhmetov, K.M.; Arynov, S.

    1996-01-01

    The main attention is paid to works with particle beam in up-to-date nuclear investigations. The application of magnet prism β-spectrometer for works in 'on-line' experiments is considered in this article. The source chamber and detector chamber are distanted from each other on great distance (4 m) and are out of operation field of spectrometer. There is a reliable defence of operating field of device from external parasitic fields by the magnetic screens system. The additional advantage is a factor that source (target) and detector could replacing in specific directions about few centimetres during the device operating. The main β-spectroscopic performances of device are compared with Grenoble spectroscopic complex. The liner depression of prism spectrometer account for from 3,6 up to 6 m; light force - from 2·10 -4 up to 6·10 -4 up to 4π; operating resolving power - 0,02-0,05% by impulse. Investigation range is from several keV up to 3 MeV. There are all opportunities for installing of the on-line magnetic prism spectrometer on the U-150 accelerator and the WWR-K reactor. Spectrometer application in 'on-line' experiments gives possibility to obtain more wide information. 4 refs

  17. Diamond-coated ATR prism for infrared absorption spectroscopy of surface-modified diamond nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Remes, Z., E-mail: remes@fzu.cz [Institute of Physics of the ASCR, v.v.i., Cukrovarnicka 10, Praha 6 (Czech Republic); Kozak, H.; Rezek, B.; Ukraintsev, E.; Babchenko, O.; Kromka, A. [Institute of Physics of the ASCR, v.v.i., Cukrovarnicka 10, Praha 6 (Czech Republic); Girard, H.A.; Arnault, J.-C.; Bergonzo, P. [CEA, LIST, Diamond Sensors Laboratory, F-91191 Gif-sur-Yvette (France)

    2013-04-01

    Linear antenna microwave chemical vapor deposition process was used to homogeneously coat a 7 cm long silicon prism by 85 nm thin nanocrystalline diamond (NCD) layer. To show the advantages of the NCD-coated prism for attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) of nanoparticles, we apply diamond nanoparticles (DNPs) of 5 nm nominal size with various surface modifications by a drop-casting of their methanol dispersions. ATR-FTIR spectra of as-received, air-annealed, plasma-oxidized, and plasma-hydrogenated DNPs were measured in the 4000–1500 cm{sup −1} spectral range. The spectra show high spectral resolution, high sensitivity to specific DNP surface moieties, and repeatability. The NCD coating provides mechanical protection against scratching and chemical stability of the surface. Moreover, unlike on bare Si surface, NCD hydrophilic properties enable optically homogeneous coverage by DNPs with some aggregation on submicron scale as evidenced by scanning electron microscopy and atomic force microscopy. Compared to transmission FTIR regime with KBr pellets, direct and uniform deposition of DNPs on NCD-ATR prism significantly simplifies and speeds up the analysis (from days to minutes). We discuss prospects for in situ monitoring of surface modifications and molecular grafting.

  18. Prism-coupled Cherenkov phase-matched terahertz wave generation using a DAST crystal.

    Science.gov (United States)

    Suizu, Koji; Shibuya, Takayuki; Uchida, Hirohisa; Kawase, Kodo

    2010-02-15

    Terahertz (THz) wave generation based on nonlinear frequency conversion is a promising method for realizing a tunable monochromatic high-power THz-wave source. Unfortunately, many nonlinear crystals have strong absorption in the THz frequency region. This limits efficient and widely tunable THz-wave generation. The Cherenkov phase-matching method is one of the most promising techniques for overcoming these problems. Here, we propose a prism-coupled Cherenkov phase-matching (PCC-PM) method, in which a prism with a suitable refractive index at THz frequencies is coupled to a nonlinear crystal. This has the following advantages. Many crystals can be used as THz-wave emitters; the phase-matching condition inside the crystal does not have to be observed; the absorption of the crystal does not prevent efficient generation of radiation; and pump sources with arbitrary wavelengths can be employed. Here we demonstrate PCC-PM THz-wave generation using the organic crystal 4-dimethylamino-N-metyl-4-stilbazolium tosylate (DAST) and a Si prism coupler. We obtain THz-wave radiation with tunability of approximately 0.1 to 10 THz and with no deep absorption features resulting from the absorption spectrum of the crystal. The obtained spectra did not depend on the pump wavelength in the range 1300 to 1450 nm. This simple technique shows promise for generating THz radiation using a wide variety of nonlinear crystals.

  19. Compact, semi-passive beam steering prism array for solar concentrators.

    Science.gov (United States)

    Zheng, Cheng; Li, Qiyuan; Rosengarten, Gary; Hawkes, Evatt; Taylor, Robert A

    2017-05-10

    In order to maximize solar energy utilization in a limited space (e.g., rooftops), solar collectors should track the sun. As an alternative to rotational tracking systems, this paper presents a compact, semi-passive beam steering prism array which has been designed, analyzed, and tested for solar applications. The proposed prism array enables a linear concentrator system to remain stationary so that it can integrate with a variety of different solar concentrators, and which should be particularly useful for systems which require a low profile (namely rooftop-mounted systems). A case study of this prism array working within a specific rooftop solar collector demonstrates that it can boost the average daily optical efficiency of the collector by 32.7% and expand its effective working time from 6 h to 7.33 h. Overall, the proposed design provides an alternative way to "follow" the sun for a wide range of solar thermal and photovoltaic concentrator systems.

  20. A novel and compact spectral imaging system based on two curved prisms

    Science.gov (United States)

    Nie, Yunfeng; Bin, Xiangli; Zhou, Jinsong; Li, Yang

    2013-09-01

    As a novel detection approach which simultaneously acquires two-dimensional visual picture and one-dimensional spectral information, spectral imaging offers promising applications on biomedical imaging, conservation and identification of artworks, surveillance of food safety, and so forth. A novel moderate-resolution spectral imaging system consisting of merely two optical elements is illustrated in this paper. It can realize the function of a relay imaging system as well as a 10nm spectral resolution spectroscopy. Compared to conventional prismatic imaging spectrometers, this design is compact and concise with only two special curved prisms by utilizing two reflective surfaces. In contrast to spectral imagers based on diffractive grating, the usage of compound-prism possesses characteristics of higher energy utilization and wider free spectral range. The seidel aberration theory and dispersive principle of this special prism are analyzed at first. According to the results, the optical system of this design is simulated, and the performance evaluation including spot diagram, MTF and distortion, is presented. In the end, considering the difficulty and particularity of manufacture and alignment, an available method for fabrication and measurement is proposed.

  1. La enfermedad de Chagas en la zona central de Honduras: conocimientos, creencias y prácticas Knowledge, beliefs and practices about Chagas' disease in central Honduras

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    Gustavo Ávila Montes

    1998-03-01

    Full Text Available En el período de noviembre a diciembre de 1991 y en marzo de 1993 se realizó una encuesta en 17 comunidades rurales de la parte central de Honduras. Las comunidades correspondían a dos zonas en las que la enfermedad de Chagas es endémica. En una de las zonas habían tenido lugar actividades de control de la enfermedad. Fueron entrevistados 849 adultos, uno en cada uno de otros tantos hogares familiares. El objetivo de la encuesta fue investigar y comparar en ambas zonas los conocimientos sobre la enfermedad de Chagas y sus mecanismos de transmisión, las prácticas para evitar la presencia de triatómidos en las viviendas, las creencias acerca de los triatómidos y su control, y las fuentes a partir de las cuales la población obtiene información sobre la enfermedad. Se utilizó un cuestionario de 23 preguntas validado y precodificado. Casi 100% de los entrevistados pudieron reconocer el vector y conocían sus hábitos, pero solo 30,1% sabían que el Triatoma es vector transmisor de la enfermedad y apenas 6% pudieron mencionar su relación con una afección cardíaca crónica. El 47,9% de los entrevistados indicó que la responsabilidad de eliminar los triatómidos de la vivienda es personal, aunque 78% consideraron como medida de control la aplicación institucional de insecticidas. El contacto personal entre el funcionario institucional y los miembros de la comunidad fue la principal fuente de información entre los que mencionaron haber oído de la enfermedad de Chagas (41,0%. Los resultados sugieren que al planificar medidas de control se debe incluir el componente de educación sanitaria. Ha de ponerse énfasis en el papel que desempeñan los triatómidos en la transmisión, así como en la importancia de mejorar la vivienda como medida eficaz y sostenible mediante la participación de la comunidad. Este componente deberá ser desarrollado por canales de comunicación interpersonales para obtener un mayor impacto.From November to

  2. [The history of Chagas' disease in Argentina: conceptual, institutional, and political evolution].

    Science.gov (United States)

    Zabala, Juan Pablo

    2009-07-01

    In the one hundred years since the identification of Chagas disease, major changes have occurred in its scientific conception, institutional recognition, and political weight. From a medical perspective, it was seen as the cause of goiter, next its acute effects were emphasized, and then its effects on cardiac health received greater attention. In similar fashion, sanitary policy first downplayed the disease's importance, then elevated it to the role of a national cause, and gradually relegated it to the bottom of the agenda. The article briefly presents the key points of this historical trajectory in Argentina, exploring the cognitive, political, and institutional underpinnings of the disease as both a social and biological fact.

  3. Training the Next Generation of Scientists: System Dynamics Modeling of Chagas Disease (American Trypanosomiasis) transmission.

    Science.gov (United States)

    Goff, P.; Hulse, A.; Harder, H. R.; Pierce, L. A.; Rizzo, D.; Hanley, J.; Orantes, L.; Stevens, L.; Justi, S.; Monroy, C.

    2015-12-01

    A computational simulation has been designed as an investigative case study by high school students to introduce system dynamics modeling into high school curriculum. This case study approach leads users through the forensics necessary to diagnose an unknown disease in a Central American village. This disease, Chagas, is endemic to 21 Latin American countries. The CDC estimates that of the 110 million people living in areas with the disease, 8 million are infected, with as many as 300,000 US cases. Chagas is caused by the protozoan parasite, Trypanosoma cruzi, and is spread via blood feeding insect (vectors), that feed on vertebrates and live in crevasses in the walls and roofs of adobe homes. One-third of the infected people will develop chronic Chagas who are asymptomatic for years before their heart or GI tract become enlarged resulting in death. The case study has three parts. Students play the role of WHO field investigators and work collaboratively to: 1) use genetics to identify the host(s) and vector of the disease 2) use a STELLA™ SIR (Susceptible, Infected, Recovered) system dynamics model to study Chagas at the village scale and 3) develop management strategies. The simulations identify mitigation strategies known as Ecohealth Interventions (e.g., home improvements using local materials) to help stakeholders test and compare multiple optima. High school students collaborated with researchers from the University of Vermont, Loyola University and Universidad de San Carlos, Guatemala, working in labs, interviewing researchers, and incorporating mulitple field data as part of a NSF-funded multiyear grant. The model displays stable equilibria of hosts, vectors, and disease-states. Sensitivity analyses show measures of household condition and presence of vertebrates were significant leverage points, supporting other findings by the University research team. The village-scale model explores multiple solutions to disease mitigation for the purpose of producing

  4. PREVALENCE OF CHAGAS DISEASE IN A RURAL AREA IN THE STATE OF CEARA, BRAZIL

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    Erlane Chaves FREITAS

    2015-10-01

    Full Text Available SUMMARY Chagas disease is caused by Trypanosoma cruzi and affects about two to three million people in Brazil, still figuring as an important public health problem. A study was conducted in a rural area of the municipality of Limoeiro do Norte - CE, northeastern Brazil, aiming to determine the prevalence of T. cruzi infection. Of the inhabitants, 52% were examined, among whom 2.6% (4/154 were seropositive in at least two serological tests. All seropositive individuals were older than 50 years, farmers, with a low education and a family income of less than three minimum wages. Active surveillance may be an alternative for early detection of this disease.

  5. Carvedilol Enhances the Antioxidant Effect of Vitamins E and C in Chronic Chagas Heart Disease

    International Nuclear Information System (INIS)

    Budni, Patrícia; Pedrosa, Roberto Coury; Dalmarco, Eduardo Monguilhott; Dalmarco, Juliana Bastos; Frode, Tânia Sílvia; Wilhelm, Danilo Filho

    2013-01-01

    Chagas disease is still an important endemic disease in Brazil, and the cardiac involvement is its more severe manifestation. To verify whether the concomitant use of carvedilol will enhance the antioxidant effect of vitamins E and C in reducing the systemic oxidative stress in chronic Chagas heart disease. A total of 42 patients with Chagas heart disease were studied. They were divided into four groups according to the modified Los Andes classification: 10 patients in group IA (normal electrocardiogram and echocardiogram; no cardiac involvement); 20 patients in group IB (normal electrocardiogram and abnormal echocardiogram; mild cardiac involvement); eight patients in group II (abnormal electrocardiogram and echocardiogram; no heart failure; moderate cardiac involvement); and four patients in group III (abnormal electrocardiogram and echocardiogram with heart failure; severe cardiac involvement). Blood levels of markers of oxidative stress were determined before and after a six-month period of treatment with carvedilol, and six months after combined therapy of carvedilol with vitamins E and C. The markers analyzed were as follows: activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase and reductase, myeloperoxidade and adenosine deaminase; and the levels of reduced glutathione, thiobarbituric-acid reactive substances, protein carbonyls, vitamin E, and nitric oxide. After treatment with carvedilol, all groups showed significant decrease in protein carbonyls and reduced glutathione levels, whereas nitric oxide levels and adenosine activity increased significantly only in the less severely affected group (IA). In addition, the activity of most of the antioxidant enzymes was decreased in the less severely affected groups (IA and IB). By combining the vitamins with carvedilol, a reduction in protein damage, in glutathione levels, and in the activity of most of the antioxidant enzymes were observed. The decrease in oxidative

  6. Description of an oral Chagas disease outbreak in Venezuela, including a vertically transmitted case.

    Science.gov (United States)

    Noya, Belkisyolé Alarcón de; Pérez-Chacón, Gladymar; Díaz-Bello, Zoraida; Dickson, Sonia; Muñoz-Calderón, Arturo; Hernández, Carlos; Pérez, Yadira; Mauriello, Luciano; Moronta, Eyleen

    2017-08-01

    We describe the eleventh major outbreak of foodborne Trypanosoma cruzi transmission in urban Venezuela, including evidence for vertical transmission from the index case to her fetus. After confirming fetal death at 24 weeks of gestation, pregnancy interruption was performed. On direct examination of the amniotic fluid, trypomastigotes were detected. T. cruzi specific-polymerase chain reaction (PCR) also proved positive when examining autopsied fetal organs. Finally, microscopic fetal heart examination revealed amastigote nests. Acute orally transmitted Chagas disease can be life threatening or even fatal for pregnant women and unborn fetuses owing to vertical transmission. There is therefore an urgent need to improve national epidemiologic control measures.

  7. A inserção institucional do controle da doença de Chagas

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    Antônio Carlos Silveira

    2011-01-01

    Full Text Available Em 1943, a partir da criação do "Centro de Estudos e Profilaxia da Moléstia de Chagas" da Fundação Oswaldo Cruz de Bambuí em Minas Gerais, são concebidas as bases tecnológicas e metodológicas para o controle extensivo da enfermidade. Para isso foi decisivo o advento de um novo inseticida (o gammexane, P 530 e a demonstração de sua eficácia no controle dos vetores da doença de Chagas. Como resultado prático desses acontecimentos em "maio de 1950 foi oficialmente inaugurada, em Uberaba, a primeira campanha de profilaxia da doença de Chagas, no Brasil". Mesmo que se dispusesse desde então de meios para fazer o controle da transmissão vetorial da endemia chagásica, não se dispunha dos recursos financeiros exigidos para fazê-lo de forma abrangente e regular. O baixo nível de prioridade conferida a essa atividade se expressava em sua inserção institucional. Em 1941, foram criados os Serviços Nacionais, de malária, peste, varíola, entre outros, enquanto a doença de Chagas fazia parte da Divisão de Organização Sanitária (DOS, que reunia enfermidades consideradas de menor importância. Em 1956 o Departamento Nacional de Endemias Rurais (DNERu incorporou todas as chamadas grandes endemias em uma única instituição, mas na prática isso não significou a implementação das ações de controle da doença de Chagas. Com a reestruturação do Ministério da Saúde em 1970, a Superintendência de Campanhas de Saúde Pública (SUCAM abarcou todas as endemias rurais, e a doença de Chagas passou a ter o status de Divisão Nacional, na mesma posição hierárquica daquelas outras doenças transmitidas por vetores antes consideradas prioritárias. Essa condição determinou a possibilidade de uma repartição de recursos mais equilibrada, o que efetivamente ocorreu, com a realocação de pessoal e insumos do programa de malária para o controle vetorial da doença de Chagas. Em 1991, a Fundação Nacional de Saúde sucedeu a SUCAM

  8. Distantiae transmission of Trypanosoma cruzi: a new epidemiological feature of acute Chagas disease in Brazil.

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    Samanta Cristina das Chagas Xavier

    2014-05-01

    Full Text Available BACKGROUND: The new epidemiological scenario of orally transmitted Chagas disease that has emerged in Brazil, and mainly in the Amazon region, needs to be addressed with a new and systematic focus. Belém, the capital of Pará state, reports the highest number of acute Chagas disease (ACD cases associated with the consumption of açaí juice. METHODOLOGY/PRINCIPAL FINDINGS: The wild and domestic enzootic transmission cycles of Trypanosoma cruzi were evaluated in the two locations (Jurunas and Val-de Cães that report the majority of the autochthonous cases of ACD in Belém city. Moreover, we evaluated the enzootic cycle on the three islands that provide most of the açaí fruit that is consumed in these localities. We employed parasitological and serological tests throughout to evaluate infectivity competence and exposure to T. cruzi. In Val-de-Cães, no wild mammal presented positive parasitological tests, and 56% seroprevalence was observed, with low serological titers. Three of 14 triatomines were found to be infected (TcI. This unexpected epidemiological picture does not explain the high number of autochthonous ACD cases. In Jurunas, the cases of ACD could not be autochthonous because of the absence of any enzootic cycle of T. cruzi. In contrast, in the 3 island areas from which the açaí fruit originates, 66.7% of wild mammals and two dogs displayed positive hemocultures, and 15.6% of triatomines were found to be infected by T. cruzi. Genotyping by mini-exon gene and PCR-RFLP (1f8/Akw21I targeting revealed that the mammals and triatomines from the islands harbored TcI and Trypanosoma rangeli in single and mixed infections. CONCLUSION/SIGNIFICANCE: These findings show that cases of Chagas disease in the urban area of Belém may be derived from infected triatomines coming together with the açaí fruits from distant islands. We term this new epidemiological feature of Chagas disease as "Distantiae transmission".

  9. Carvedilol Enhances the Antioxidant Effect of Vitamins E and C in Chronic Chagas Heart Disease

    Energy Technology Data Exchange (ETDEWEB)

    Budni, Patrícia, E-mail: budnip@gmail.com [Universidade Federal de Santa Catarina, Florianópolis, SC (Brazil); Pedrosa, Roberto Coury [Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Hospital Universitário Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Dalmarco, Eduardo Monguilhott; Dalmarco, Juliana Bastos; Frode, Tânia Sílvia; Wilhelm, Danilo Filho [Universidade Federal de Santa Catarina, Florianópolis, SC (Brazil)

    2013-10-15

    Chagas disease is still an important endemic disease in Brazil, and the cardiac involvement is its more severe manifestation. To verify whether the concomitant use of carvedilol will enhance the antioxidant effect of vitamins E and C in reducing the systemic oxidative stress in chronic Chagas heart disease. A total of 42 patients with Chagas heart disease were studied. They were divided into four groups according to the modified Los Andes classification: 10 patients in group IA (normal electrocardiogram and echocardiogram; no cardiac involvement); 20 patients in group IB (normal electrocardiogram and abnormal echocardiogram; mild cardiac involvement); eight patients in group II (abnormal electrocardiogram and echocardiogram; no heart failure; moderate cardiac involvement); and four patients in group III (abnormal electrocardiogram and echocardiogram with heart failure; severe cardiac involvement). Blood levels of markers of oxidative stress were determined before and after a six-month period of treatment with carvedilol, and six months after combined therapy of carvedilol with vitamins E and C. The markers analyzed were as follows: activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase and reductase, myeloperoxidade and adenosine deaminase; and the levels of reduced glutathione, thiobarbituric-acid reactive substances, protein carbonyls, vitamin E, and nitric oxide. After treatment with carvedilol, all groups showed significant decrease in protein carbonyls and reduced glutathione levels, whereas nitric oxide levels and adenosine activity increased significantly only in the less severely affected group (IA). In addition, the activity of most of the antioxidant enzymes was decreased in the less severely affected groups (IA and IB). By combining the vitamins with carvedilol, a reduction in protein damage, in glutathione levels, and in the activity of most of the antioxidant enzymes were observed. The decrease in oxidative

  10. Training Systems Modelers through the Development of a Multi-scale Chagas Disease Risk Model

    Science.gov (United States)

    Hanley, J.; Stevens-Goodnight, S.; Kulkarni, S.; Bustamante, D.; Fytilis, N.; Goff, P.; Monroy, C.; Morrissey, L. A.; Orantes, L.; Stevens, L.; Dorn, P.; Lucero, D.; Rios, J.; Rizzo, D. M.

    2012-12-01

    The goal of our NSF-sponsored Division of Behavioral and Cognitive Sciences grant is to create a multidisciplinary approach to develop spatially explicit models of vector-borne disease risk using Chagas disease as our model. Chagas disease is a parasitic disease endemic to Latin America that afflicts an estimated 10 million people. The causative agent (Trypanosoma cruzi) is most commonly transmitted to humans by blood feeding triatomine insect vectors. Our objectives are: (1) advance knowledge on the multiple interacting factors affecting the transmission of Chagas disease, and (2) provide next generation genomic and spatial analysis tools applicable to the study of other vector-borne diseases worldwide. This funding is a collaborative effort between the RSENR (UVM), the School of Engineering (UVM), the Department of Biology (UVM), the Department of Biological Sciences (Loyola (New Orleans)) and the Laboratory of Applied Entomology and Parasitology (Universidad de San Carlos). Throughout this five-year study, multi-educational groups (i.e., high school, undergraduate, graduate, and postdoctoral) will be trained in systems modeling. This systems approach challenges students to incorporate environmental, social, and economic as well as technical aspects and enables modelers to simulate and visualize topics that would either be too expensive, complex or difficult to study directly (Yasar and Landau 2003). We launch this research by developing a set of multi-scale, epidemiological models of Chagas disease risk using STELLA® software v.9.1.3 (isee systems, inc., Lebanon, NH). We use this particular system dynamics software as a starting point because of its simple graphical user interface (e.g., behavior-over-time graphs, stock/flow diagrams, and causal loops). To date, high school and undergraduate students have created a set of multi-scale (i.e., homestead, village, and regional) disease models. Modeling the system at multiple spatial scales forces recognition that

  11. Inositol metabolism in Trypanosoma cruzi: potential target for chemotherapy against Chagas' disease

    Directory of Open Access Journals (Sweden)

    MECIA M. OLIVEIRA

    2000-09-01

    Full Text Available Chagas' disease is a debilitating and often fatal disease caused by the protozoan parasite Trypanosoma cruzi. The great majority of surface molecules in trypanosomes are either inositol-containing phospholipids or glycoproteins that are anchored into the plasma membrane by glycosylphosphatidylinositol anchors. The polyalcohol myo-inositol is the precursor for the biosynthesis of these molecules. In this brief review, recent findings on some aspects of the molecular and cellular fate of inositol in T. cruzi life cycle are discussed and identified some points that could be targets for the development of parasite-specific therapeutic agents.

  12. [Why defer blood donor candidates because of an exposure risk to Chagas disease?].

    Science.gov (United States)

    Garraud, O; Pelletier, B; Aznar, C

    2008-06-01

    Various infectious agents can be transmitted by blood exposure, which comprises of transfusion, of which hemoparasites that are commonly absent from European countries but that can have infected blood donor candidates born, raised or having been living in the Tropics. Among those hemoparasites is Trypanosoma cruzi, responsible for Chagas disease. T. cruzi is responsible for acute post-transfusion infections every year in endemic areas (South America) and also, more incidently, in North America. There are situations which expose European blood donors to this risk and the present essay discusses arguments which have now been taken into consideration by certain transfusion systems such as the French one.

  13. PERANCANGAN DAN IMPLEMENTASI SISTEM PENGUKURAN KINERJA DENGAN METODE PERFORMANCE PRISM (Studi Kasus pada Hotel X

    Directory of Open Access Journals (Sweden)

    Iwan Vanany

    2004-01-01

    Full Text Available This article described a result of research design of performance measurement system in hotel business with Performance Prism Model. As long as, performance measurement system at hotel X not yet representatived organization performance according to comprehensif and integrated. Because of needed redesign performance measurement system with new model. From the objective condition of hotel X, Performance Prism model more representative than others. The result of design described that stakeholder in hotel X such as: customer, employee, supplier, owner and investor, and regulator and community. From the performance measurement system design are obtained 36 types Key Performance Indicator (KPI such as: 6 KPI of customer, 9 KPI of staff manajerial, 9 KPI of staff operational, 4 KPI of supplier, 3 KPI of investor, and 5 KPI of regulator & community. Result of implementation performance measurement system with scoring system indicates that the amount of scor current performance indicator is 50,75%. Result of measurement can be based management act evaluation and choice planning improvement organization and all Stakeholder requirements must be request. Abstract in Bahasa Indonesia : Artikel ini menguraikan hasil penelitian perancangan sistem pengukuran kinerja pada sebuah perusahaan dalam bisnis hotel dengan model Performance Prism. Selama ini, sistem pengukuran kinerja di Hotel X belum merepresentasikan kinerja organisasi secara komprehensif dan integratif. Oleh karena itu, perlu dilakukan perancangan kembali sistem pengukuran kinerjanya. Dari kondisi objektif hotel X, model yang tepat digunakan adalah model Performance Prism dibanding model lain. Hasil rancangan menunjukkan bahwa stakeholder hotel X meliputi: konsumen, tenaga kerja, supplier, pemilik/investor, serta pemerintah dan masyarakat sekitar lingkungan hotel. Sistem pengukuran kinerja memuat 36 KPI yang meliputi 6 KPI konsumen, 9 KPI staff manajerial, 9 KPI staff operasional, 4 KPI supplier, 3

  14. A regional fight against Chagas disease: lessons learned from a successful collaborative partnership.

    Science.gov (United States)

    Salerno, Rosina; Salvatella, Roberto; Issa, Julie; Anzola, Maria Carolina

    2015-01-01

    To identify the intangible elements that characterize the successful effort to fight Chagas disease in the Americas, determine how they contributed to the overall success of the partnership, and learn lessons from the experience that could be applied to other programs. This study was based on the Partnership Assessment Tool (PAT) developed by the Nuffield Institute for Health ("the Institute") at the University of Leeds (London). The PAT draws heavily on scientific literature and the extensive experience of sociologists and health experts working for the Institute. The Pan American Health Organization (PAHO) modified the tool slightly to adapt it to its needs and provide a general structure for the study. The six key principles of the PAT framework were applied in the design of the research questionnaires. The findings show that a successful collaboration requires a clear objective; a good-quality pool of data; and comprehensive qualitative and quantitative knowledge of the problem, its dimensions, and its impact. The collaboration was elaborated from a common idea and a shared, quantified plan based on data gathered by independent scientists plus a strategy with explicit milestones. The clarity of purpose allowed for an improved synergy of efforts and made it possible to resolve differences in opinions and approaches. PAHO's experience with effective collaborations such as the joint initiative to fight Chagas disease provides a rich knowledge base for analysis of the advantages, limitations, and paradigms of community involvement, collaborative practices, and partnerships.

  15. Molecular diagnostics for Chagas disease: up to date and novel methodologies.

    Science.gov (United States)

    Alonso-Padilla, Julio; Gallego, Montserrat; Schijman, Alejandro G; Gascon, Joaquim

    2017-07-01

    Chagas disease is caused by the parasite Trypanosoma cruzi. It affects 7 million people, mainly in Latin America. Diagnosis is usually made serologically, but at some clinical scenarios serology cannot be used. Then, molecular detection is required for early detection of congenital transmission, treatment response follow up, and diagnosis of immune-suppression reactivation. However, present tests are technically demanding and require well-equipped laboratories which make them unfeasible in low-resources endemic regions. Areas covered: Available molecular tools for detection of T. cruzi DNA, paying particular attention to quantitative PCR protocols, and to the latest developments of user-friendly molecular diagnostic methodologies. Expert commentary: In the absence of appropriate biomarkers, molecular diagnosis is the only option for the assessment of treatment response. Besides, it is very useful for the early detection of acute infections, like congenital cases. Since current Chagas disease molecular tests are restricted to referential labs, research efforts must focus in the implementation of easy-to-use diagnostic tools in order to overcome the access to diagnosis gap.

  16. Chagas disease: modulation of the inflammatory response by acetylcholinesterase in hematological cells and brain tissue.

    Science.gov (United States)

    Silva, Aniélen D; Bottari, Nathieli B; do Carmo, Guilherme M; Baldissera, Matheus D; Souza, Carine F; Machado, Vanessa S; Morsch, Vera M; Schetinger, Maria Rosa C; Mendes, Ricardo E; Monteiro, Silvia G; Da Silva, Aleksandro S

    2018-01-01

    Chagas disease is an acute or chronic illness that causes severe inflammatory response, and consequently, it may activate the inflammatory cholinergic pathway, which is regulated by cholinesterases, including the acetylcholinesterase. This enzyme is responsible for the regulation of acetylcholine levels, an anti-inflammatory molecule linked to the inflammatory response during parasitic diseases. Thus, the aim of this study was to investigate whether Trypanosoma cruzi infection can alter the activity of acetylcholinesterase and acetylcholine levels in mice, and whether these alterations are linked to the inflammatory cholinergic signaling pathway. Twenty-four mice were divided into two groups: uninfected (control group, n = 12) and infected by T. cruzi, Y strain (n = 12). The animals developed acute disease with a peak of parasitemia on day 7 post-infection (PI). Blood, lymphocytes, and brain were analyzed on days 6 and 12 post-infection. In the brain, acetylcholine and nitric oxide levels, myeloperoxidase activity, and histopathology were analyzed. In total blood and brain, acetylcholinesterase activity decreased at both times. On the other hand, acetylcholinesterase activity in lymphocytes increased on day 6 PI compared with the control group. Infection by T. cruzi increased acetylcholine and nitric oxide levels and histopathological damage in the brain of mice associated to increased myeloperoxidase activity. Therefore, an intense inflammatory response in mice with acute Chagas disease in the central nervous system caused an anti-inflammatory response by the activation of the cholinergic inflammatory pathway.

  17. Influence of the HLA class II polymorphism in chronic Chagas' disease.

    Science.gov (United States)

    Fernandez-Mestre, M T; Layrisse, Z; Montagnani, S; Acquatella, H; Catalioti, F; Matos, M; Balbas, O; Makhatadze, N; Dominguez, E; Herrera, F; Madrigal, A

    1998-04-01

    Chagas' disease or American trypanosomiasis due to Trypanosoma cruzi has existed at least since the time of the Inca empire and contributes significantly to cardiovascular morbidity and mortality in several countries of this continent. Due to the fundamental role of human class II molecules polymorphic residues in the control of the immune response, a study was designed to define by DNA typing HLA class II alleles in a sample of 67 serologically positive individuals with and without cardiomyopathy and in 156 healthy controls of similar ethnic origin. Genomic DNA extraction, PCR amplification of the HLA-DRB1 and DQB1 second exon regions and hybridization to labelled specific probes were carried out following the 11th International Histocompatibility Workshop reference protocol. Comparison of DRB1 and DQB1 allele frequencies among the patients and control subjects showed a decreased frequency of DRB1*14 and DQB1*0303 in the patients, suggesting independent protective effects to the chronic infection in this population. Allele frequencies comparison between patients with and without cardiomyopathy showed a higher frequency of DRB1*01, DRB1*08 and DQB1*0501 and a decreased frequency of DRB1*1501 in the patients with arrhythmia and congestive heart failure. The results suggest that HLA Class II genes may be associated with the development of a chronic infection and with heart damage in Chagas' disease.

  18. Acute Chagas' cardiopathy in a polar bear (Ursus maritimus in Guadalajara, Mexico

    Directory of Open Access Journals (Sweden)

    J. Jaime-Andrade G.

    1997-08-01

    Full Text Available We report a 24 year old female polar bear (Ursus maritimus who contracted Chagas' infection at the Guadalajara Zoo, in Jalisco, México, and died of acute Chagas' carditis 15 days later. The histopathological findings are described, as well as the presence of triatomines (Triatoma longipennis Usinger infected with Trypanosoma cruzi collected within 5 meters from the place where the animal lived in the city of Guadalajara.Relatamos o caso de uma ursa polar (Ursus maritimus de 24 anos de idade, que contraiu a infecção chagásica no Zoológico de Guadalajara, em Jalisco, no México, e morreu de cardite chagásica aguda 15 dias após o início da sintomatologia. Os achados histopatológicos são descritos, bem como a presença de triatomíneos (Triatoma longipennis Usinger infectados por Trypanosoma cruzi coletados a 5 metros do local onde o animal vivia, na cidade de Guadalajara.

  19. Evolution of Chagas' disease in Brazil. Epidemiological perspective and challenges for the future: a critical review.

    Science.gov (United States)

    Bello Corassa, Rafael; Aceijas, Carmen; Alves, Paula Aryane Brito; Garelick, Hemda

    2017-09-01

    This article aimed to provide a critical review of the evolution of Chagas' disease (ChD) in Brazil, its magnitude, historical development and management, and challenges for the future. A literature search was performed using PubMed, SciELO and Google Scholar and throughout collected articles' references. Narrative analysis was structured around five main themes identified: vector transmission, control programme, transfusion, oral and congenital transmission. In Brazil, the Chagas' Disease Control Programme was fully implemented in the 1980s, when it reached practically all the endemic areas, and in 1991, the Southern Cone Initiative was created, aiming to control the disease transmission through eliminating the Triatoma infestans and controlling blood banks. As a result, the prevalence of chagasic donors in blood banks reduced from 4.4% in the 1980s to 0.2% in 2005. In 2006, Pan American Health Organization (PAHO) certified the interruption of transmission of ChD through this vector in Brazil. However, there are still challenges, such as the domiciliation of new vector species, the need for medical care of the infected individuals, the prevention of alternative mechanisms of transmission, the loss of political concern regarding the disease and the weakening of the control programme. Despite the progress towards control, there are still many challenges ahead to maintain and expand such control and minimise the risk of re-emergence.

  20. Congenital Chagas's disease in an urban population: investigation of infected twins.

    Science.gov (United States)

    Hoff, R; Mott, K E; Milanesi, M L; Bittencourt, A L; Barbosa, H S

    1978-01-01

    In the Nordeste de Amaralina suburb of Salvador Bahia, Brazil, 47 of 285 pregnant women surveyed had complement fixing antibodies to Trypanosoma cruzi. At delivery T. cruzi was detected in one of 17 placentas from the sero-positive women. The offspring of this case were premature twins and T. cruzi was detected in the peripheral blood of each before death. At autopsy the gastro-intestinal tract and urinary bladder of both were severely affected. Immunofluorescence tests on cord sera, including the single case with T. cruzi in the placenta, were negative for IgM antibodies to T. cruzi. The mother of the infected twins and three of her living children, who were born and have resided in the city, were also infected with T. cruzi. Although the children had visited an area endemic for Chagas's disease for short periods, the mode of transmission in this family may have been transplacental. The value of the immunofluorescence test in the diagnosis of congenital Chagas's disease is discussed.

  1. Prevalence of Chagas disease in medical students from 16 Latin American countries attending

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    Miguel A. Serra Valdés

    2012-06-01

    Full Text Available Introduction: One of the infectious illnesses that have repercussion in Latin America are the Chagas illness. Objective: with the objective of identifying the students with positive serology for the illness of Chagas and describe the characteristics in the same thing with focussing epidemiological carried out to him the present study. Method: It become fulfilled a observational investigation, descriptive and prospectival. It decided the prevalencial in the Latin American students of medicine that resides in the school Salvador Allende in the period understanded between October of the 2009 to January of the 2010 by means of serology, other clinical studieses and examination. They took shelter the variables of the clinical records and of personal interview.. Results: Affected 50 of the Bolivian delegation. The prevalence went of 6.6% of this delegation. Have clinical symptoms. The detected alterations went the ventricular hypertrophy left and the disorders of transportation and of the rhythm for electrocardiogram. It predominated the masculine sex and the rural origin. It found variability in the results of laboratory, being positive in their country and negative in Cuba and vice versa. Single 56% fulfilled the treatment. The adverse reactions went minims. Conclusion: It constitutes a sanitary problem and demands a better diagnosis, control and follow-up.

  2. A revision of thirteen species of Triatominae (Hemiptera: Reduviidae vectors of Chagas disease in Mexico

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    Salazar-Schettino Paz Maria

    2010-10-01

    Full Text Available Vectors of Trypanosoma cruzi, parasite responsible for Chagas disease, are divided in intradomestic, peridomestic and sylvatic. The intradomestic are Triatoma barberi and Triatoma dimidiata, two species that represent the highest health risk among the Mexican population. Triatoma dimidiata is a species found mainly inside human habitats, but in Yucatan, it corresponds to the peridomicile vectors. Also in the peridomicile most of Chagas disease vectors are found: Meccus bassolsae, M. longipennis, M. mazzottii, M pallidipennis, M. phyllosomus, M picturata, Triatoma gerstaeckeri, T mexicana, T rubida, Dipetalogaster máxima (the last two are in the process of becoming adapted to the domicile, Panstrongylus rufotuberculatus which occasionally enters the domicile in its adult stage, and Rhodnius prolixus, which is practically controlled in the country. Peridomestic vectors are of lower risk in the transmission dynamics, as compared to the intradomestic ones. For the control of the intradomestic vectors, health education programs, improvements of housing, and the use of pesticides are essential To control the peridomestic vectors, health education programs are required, as well as the use of mosquito nets on doors and windows and around beds, aside from cementing the stone wall fences.

  3. Diagnostic electrocardiography in epidemiological studies of Chagas' disease: multicenter evaluation of a standardized method

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    Lázzari Julio O.

    1998-01-01

    Full Text Available An electrocardiographic recording method with an associated reading guide, designed for epidemiological studies on Chagas' disease, was tested to assess its diagnostic reproducibility. Six cardiologists from five countries each read 100 electrocardiographic (ECG tracings, including 30 from chronic chagasic patients, then reread them after an interval of 6 months. The readings were blind, with the tracings numbered randomly for the first reading and renumbered randomly for the second reading. The physicians, all experienced in interpreting ECGs from chagasic patients, followed printed instructions for reading the tracings. Reproducibility of the readings was evaluated using the kappa (k index for concordance. The results showed a high degree of interobserver concordance with respect to the diagnosis of normal vs. abnormal tracings (k = 0.66; SE 0.02. While the interpretations of some categories of ECG abnormalities were highly reproducible, others, especially those having a low prevalence, showed lower levels of concordance. Intraobserver concordance was uniformly higher than interobserver concordance. The findings of this study justify the use by specialists of the recording of readings method proposed for epidemiological studies on Chagas' disease, but warrant caution in the interpretation of some categories of electrocardiographic alterations.

  4. Diagnostic electrocardiography in epidemiological studies of Chagas' disease: multicenter evaluation of a standardized method

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    Julio O. Lázzari

    1998-11-01

    Full Text Available An electrocardiographic recording method with an associated reading guide, designed for epidemiological studies on Chagas' disease, was tested to assess its diagnostic reproducibility. Six cardiologists from five countries each read 100 electrocardiographic (ECG tracings, including 30 from chronic chagasic patients, then reread them after an interval of 6 months. The readings were blind, with the tracings numbered randomly for the first reading and renumbered randomly for the second reading. The physicians, all experienced in interpreting ECGs from chagasic patients, followed printed instructions for reading the tracings. Reproducibility of the readings was evaluated using the kappa (k index for concordance. The results showed a high degree of interobserver concordance with respect to the diagnosis of normal vs. abnormal tracings (k = 0.66; SE 0.02. While the interpretations of some categories of ECG abnormalities were highly reproducible, others, especially those having a low prevalence, showed lower levels of concordance. Intraobserver concordance was uniformly higher than interobserver concordance. The findings of this study justify the use by specialists of the recording of readings method proposed for epidemiological studies on Chagas' disease, but warrant caution in the interpretation of some categories of electrocardiographic alterations.

  5. Bibliometric assessment of the contributions of literature on Chagas disease in Latin America and the Caribbean.

    Science.gov (United States)

    Delgado-Osorio, Nathalia; Vera-Polania, Felipe; Lopez-Isaza, Andres F; Martinez-Pulgarin, Dayron F; Murillo-Abadia, Jonathan; Munoz-Urbano, Marcela; Cardona-Ospina, Jaime A; Bello, Ricardo; Lagos-Grisales, Guillermo J; Villegas-Rojas, Soraya; Rodriguez-Morales, Alfonso J

    2014-01-01

    Chagas disease, considered a parasitic neglected disease, is endemic in Latin America. Although, its mortality rate has decreased over time, it still represents a public health problem in the region. A bibliometric evaluation of the Latin American contributions on this disease was done. This study used SCI (1980-2013), MEDLINE/GOPUBMED (1802-2013), Scopus (1959-2013), SCIELO (2004-2013), and LILACS (1980-2013). Different study types have been characterized by years, origin city/country, journals and most productive authors, by country, cites and H-index. 2988 articles were retrieved from SCI (30.85% of total). Brazil was found to be the highest producer (31.22%), followed by Argentina (18.14%) and México (9.57%); the region received 47241 citations, 28.60% for Brazil (H-index=52), 18.26% of Argentina (Hindex= 43), 11.40% Bolivia (H-index=37). 4484 were retrieved from Scopus (30.20% of the total), 38.58% of which were from Brazil, 12.40% from Argentina and 8.90% from Mexico. From Medline, 6647 records were retrieved (45.58% Brazil). From SciELO, 917 articles (47.66% Brazil). From LILACS, 2165 articles (60.05% Brazil). Brazil has the highest output in the region. Despite advances in controlling Chagas disease, scientific production is low, particularly for regional bibliographic databases, which calls for more research on this disease.

  6. Cardiac Magnetic Resonance-Verified Myocardial Fibrosis in Chagas Disease: Clinical Correlates and Risk Stratification

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    Marly Uellendahl

    Full Text Available Abstract Background: Chagas disease (CD is an important cause of heart failure and mortality, mainly in Latin America. This study evaluated the morphological and functional characteristics of the heart as well the extent of myocardial fibrosis (MF in patients with CD by cardiac magnetic resonance (CMR. The prognostic value of MF evaluated by myocardial-delayed enhancement (MDE was compared with that via Rassi score. Methods: This study assessed 39 patients divided into 2 groups: 28 asymptomatic patients as indeterminate form group (IND; and symptomatic patients as Chagas Heart Disease (CHD group. All patients underwent CMR using the techniques of cine-MRI and MDE, and the amount of MF was compared with the Rassi score. Results: Regarding the morphological and functional analysis, significant differences were observed between both groups (p < 0.001. Furthermore, there was a strong correlation between the extent of MF and the Rassi score (r = 0.76. Conclusions: CMR is an important technique for evaluating patients with CD, stressing morphological and functional differences in all clinical presentations. The strong correlation with the Rassi score and the extent of MF detected by CMR emphasizes its role in the prognostic stratification of patients with CD.

  7. Soro-epidemiologia da doença de Chagas em Santa Catarina

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    BR Schlemper Jr

    1983-12-01

    Full Text Available Em Santa Catarina, o Inquérito Sorológico Nacional para doença de Chagas (CNPq-SUCAM revelou positividade de 1,3% em cerca de 74.000 amostras de soro processadas pela reação de imunofluorescência indireta em papel de filtro, com 15 municípios apresentando prevalências de 5,4% a 41,3%. Na presente investigação, em 9 dos municípios com alta prevalência, foram obtidas amostras de sangue, por punção venosa, de 222 indivíduos dos quais 140 haviam sido sorologicamente positivos e 58 negativos no Inquérito Nacional. Em 24 outros indivíduos a reação foi executada pela primeira vez. Os testes sorológicos (imunofluorescência indireta, hemaglutinação indireta, aglutinação direta com e sem 2-mercaptoetanol e fixação do complemento realizados em 3 diferentes laboratórios evidenciaram 220 soros negativos e apenas 2 positivos. Dados epidenúológicos obtidos nas áreas trabalhadas confirmaram estes resultados negativos. Os resultados discordam daqueles encontrados pelo Inquérito Sorológico Nacional e confirmam a inexistência de focos domiciliares de transmissão da doença de Chagas em Santa Catarina.

  8. Geographic Distribution of Chagas Disease Vectors in Brazil Based on Ecological Niche Modeling

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    Rodrigo Gurgel-Gonçalves

    2012-01-01

    Full Text Available Although Brazil was declared free from Chagas disease transmission by the domestic vector Triatoma infestans, human acute cases are still being registered based on transmission by native triatomine species. For a better understanding of transmission risk, the geographic distribution of Brazilian triatomines was analyzed. Sixteen out of 62 Brazilian species that both occur in >20 municipalities and present synanthropic tendencies were modeled based on their ecological niches. Panstrongylus geniculatus and P. megistus showed broad ecological ranges, but most of the species sort out by the biome in which they are distributed: Rhodnius pictipes and R. robustus in the Amazon; R. neglectus, Triatoma sordida, and T. costalimai in the Cerrado; R. nasutus, P. lutzi, T. brasiliensis, T. pseudomaculata, T. melanocephala, and T. petrocchiae in the Caatinga; T. rubrovaria in the southern pampas; T. tibiamaculata and T. vitticeps in the Atlantic Forest. Although most occurrences were recorded in open areas (Cerrado and Caatinga, our results show that all environmental conditions in the country are favorable to one or more of the species analyzed, such that almost nowhere is Chagas transmission risk negligible.

  9. Mannose-Binding Lectin and Toll-Like Receptor Polymorphisms and Chagas Disease in Chile

    Science.gov (United States)

    Zulantay, Inés; Danquah, Ina; Hamann, Lutz; Schumann, Ralf R.; Apt, Werner; Mockenhaupt, Frank P.

    2012-01-01

    Mannose-binding lectin (MBL) and Toll-like receptor (TLR) polymorphisms may influence susceptibility and manifestation of Trypanosoma cruzi infection. In northern Chile, we examined 61 asymptomatic patients with chronic Chagas disease (CD), 64 patients with chronic Chagas cardiomyopathy (CCC), and 45 healthy individuals. Low-producer MBL2*B genotypes were more common in CD patients (48%) than healthy individuals (31%; adjusted odds ratio = 2.3, 95% confidence interval = 1.01–5.4, P = 0.047) but did not differ with manifestation. In contrast, the heterozygous Toll-like receptor 4 (TLR4)-deficiency genotype D299G/T399I occurred more frequently in asymptomatic (14.8%) than CCC patients (3.1%; P = 0.02). TLR1-I602S, TLR2-R753Q, TLR6-S249P, and MAL/TIRAP-S180L did not associate with CD or CCC. These findings support the complement system to be involved in defense against Trypanosoma cruzi infection and indicate that curbed TLR4 activation might be beneficial in preventing CCC. PMID:22302853

  10. Echocardiographic parameters and survival in Chagas heart disease with severe systolic dysfunction.

    Science.gov (United States)

    Rassi, Daniela do Carmo; Vieira, Marcelo Luiz Campos; Arruda, Ana Lúcia Martins; Hotta, Viviane Tiemi; Furtado, Rogério Gomes; Rassi, Danilo Teixeira; Rassi, Salvador

    2014-03-01

    Echocardiography provides important information on the cardiac evaluation of patients with heart failure. The identification of echocardiographic parameters in severe Chagas heart disease would help implement treatment and assess prognosis. To correlate echocardiographic parameters with the endpoint cardiovascular mortality in patients with ejection fraction Celular em Cardiopatias) - Chagas heart disease arm. The following parameters were collected: left ventricular systolic and diastolic diameters and volumes; ejection fraction; left atrial diameter; left atrial volume; indexed left atrial volume; systolic pulmonary artery pressure; integral of the aortic flow velocity; myocardial performance index; rate of increase of left ventricular pressure; isovolumic relaxation time; E, A, Em, Am and Sm wave velocities; E wave deceleration time; E/A and E/Em ratios; and mitral regurgitation. In the mean 24.18-month follow-up, 27 patients died. The mean ejection fraction was 26.6 ± 5.34%. In the multivariate analysis, the parameters ejection fraction (HR = 1.114; p = 0.3704), indexed left atrial volume (HR = 1.033; p 70.71 mL/m2 were associated with a significant increase in mortality (log rank p < 0.0001). The indexed left atrial volume was the only independent predictor of mortality in this population of Chagasic patients with severe systolic dysfunction.

  11. Gas exchange during exercise in different evolutional stages of chronic Chagas' heart disease

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    Fátima Palha de Oliveira

    2000-12-01

    Full Text Available OBJECTIVE: To compare gas exchange at rest and during exercise in patients with chronic Chagas' heart disease grouped according to the Los Andes clinical/hemodynamic classification. METHODS: We studied 15 healthy volunteers and 52 patients grouped according to the Los Andes clinical/hemodynamic classification as follows: 17 patients in group IA (normal electrocardiogram/echocardiogram, 9 patients in group IB (normal electrocardiogram and abnormal echocardiogram, 14 patients in group II (abnormal electrocardiogram/echocardiogram, without congestive heart failure, and 12 patients in group III (abnormal electrocardiogram/echocardiogram with congestive heart failure. The following variables were analyzed: oxygen consumption (V O2, carbon dioxide production (V CO2, gas exchange rate (R, inspiratory current volume (V IC, expiratory current volume (V EC, respiratory frequency, minute volume (V E, heart rate (HR, maximum load, O2 pulse, and ventilatory anaerobic threshold (AT. RESULTS: When compared with the healthy group, patients in groups II and III showed significant changes in the following variables: V O2peak, V CO2peak, V ICpeak, V ECpeak, E, HR, and maximum load. Group IA showed significantly better results for these same variables as compared with group III. CONCLUSION: The functional capacity of patients in the initial phase of chronic Chagas' heart disease is higher than that of patients in an advanced phase and shows a decrease that follows the loss in cardiac-hemodynamic performance.

  12. Gas exchange during exercise in different evolutional stages of chronic Chagas' heart disease.

    Science.gov (United States)

    Oliveira, F P; Pedrosa, R C; Giannella-Neto, A

    2000-12-01

    To compare gas exchange at rest and during exercise in patients with chronic Chagas' heart disease grouped according to the Los Andes clinical hemodynamic classification. We studied 15 healthy volunteers and 52 patients grouped according to the Los Andes clinical and hemodynamic classification as follows: 17 patients in group IA (normal electrocardiogram and echocardiogram), 9 patients in group IB (normal electrocardiogram and abnormal echocardiogram), 14 patients in group II (abnormal electrocardiogram and echocardiogram, without congestive heart failure), and 12 patients in group III (abnormal electrocardiogram and echocardiogram with congestive heart failure). The following variables were analyzed: oxygen consumption (V O2), carbon dioxide production (V CO2), gas exchange rate (R), inspiratory current volume (V IC), expiratory current volume (V EC), respiratory frequency, minute volume (V E), heart rate (HR), maximum load, O2 pulse, and ventilatory anaerobic threshold (AT). When compared with the healthy group, patients in groups II and III showed significant changes in the following variables: V O2 peak, V CO2 peak, V IC peak, V EC peak, E, HR, and maximum load. Group IA showed significantly better results for these same variables as compared with group III. The functional capacity of patients in the initial phase of chronic Chagas' heart disease is higher than that of patients in an advanced phase and shows a decrease that follows the loss in cardiac-hemodynamic performance.

  13. A regional fight against Chagas disease: lessons learned from a successful collaborative partnership

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    Rosina Salerno

    2015-01-01

    Full Text Available Objective. To identify the intangible elements that characterize the successful effort to fight Chagas disease in the Americas, determine how they contributed to the overall success of the partnership, and learn lessons from the experience that could be applied to other programs. Methods. This study was based on the Partnership Assessment Tool (PAT developed by the Nuffield Institute for Health ("the Institute" at the University of Leeds (London. The PAT draws heavily on scientific literature and the extensive experience of sociologists and health experts working for the Institute. The Pan American Health Organization (PAHO modified the tool slightly to adapt it to its needs and provide a general structure for the study. The six key principles of the PAT framework were applied in the design of the research questionnaires. Results. The findings show that a successful collaboration requires a clear objective; a good-quality pool of data; and comprehensive qualitative and quantitative knowledge of the problem, its dimensions, and its impact. The collaboration was elaborated from a common idea and a shared, quantified plan based on data gathered by independent scientists plus a strategy with explicit milestones. The clarity of purpose allowed for an improved synergy of efforts and made it possible to resolve differences in opinions and approaches. Conclusions. PAHO's experience with effective collaborations such as the joint initiative to fight Chagas disease provides a rich knowledge base for analysis of the advantages, limitations, and paradigms of community involvement, collaborative practices, and partnerships.

  14. The effect of Ageratum fastigiatum extract on Rhodnius nasutus, vector of Chagas disease

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    Bethânia A. Avelar-Freitas

    2013-04-01

    Full Text Available Control of Chagas disease is based on insecticide spraying in domiciles in order to exterminate triatomine populations. However, since the vectors differ in susceptibility to currently used insecticides, the screening of the toxic potential of Brazilian flora may identify new molecules lethal to triatomines. This study evaluated the toxicity of ethanolic extract of Ageratum fastigiatum (Gardner R.M. King & H. Rob., Asteraceae, on Rhodnius nasutus, a known vector of Chagas disease. Ethanolic extracts of the aerial parts of A. fastigiatum were prepared at 25 and 50 mg/mL concentrations, and 5 µL was applied to fifth-instar nymphs of R. nasutus (n=30. Controls included nymphs that were treated with 5 µL ethanol (n=30 or left untreated (n=30. The percentage of dead insects in each group was observed at 24, 48, 72, 96 and 120 h after application. The extracts of A. fastigiatum showed a mortality rate of about 37% and 77% after 120 h, at concentrations of 25 and 50 mg/mL, respectively. In control groups, the mortality rate remained under 7%. The extract of A. fastigiatum contains a coumarin, a molecule with recognized toxicity in insects, and which may be responsible for killing the triatomines.

  15. Seroprevalencia de la enfermedad de Chagas y factores de riesgo asociados en una población de Morroa, Sucre

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    Richard Hoyos

    2007-01-01

    Conclusiones. Nuestros resultados indican que la zona estudiada presenta elementos de riesgo para el establecimiento de un ciclo de transmisión activa, se hace necesario verificar la presencia de triatominos en la zona de estudio y establecer medidas para prevenir la presencia de la enfermedad de Chagas en el área de Morroa, Sucre.

  16. Análisis epidemiológico de pacientes coinfectados con enfermedad de Chagas y cisticercosis

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    Ana Carolina Guimaraes

    2009-03-01

    Conclusión. En teoría, todos los pacientes tuvieron un riesgo similar de exposición para ambos parásitos. Sin embargo, este trabajo demuestra que, en la población estudiada, la enfermedad de Chagas fue, aproximadamente, 10 veces más frecuente en los casos coinfectados con cisticercosis.

  17. Case-control study of factors associated with chronic Chagas heart disease in patients over 50 years of age

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    Silvana de Araújo Silva

    2007-11-01

    Full Text Available A case-control study on chronic Chagas heart disease (CCHD was carried out between 1997 and 2005. Ninety patients over 50 years of age were examined for factors related to (CCHD. Fourty-six patients (51.1% with Chagas heart disease (anomalous ECG were assigned to the case group and 44 (48.9% were included in the control group as carriers of undetermined forms of chronic disease. Social, demographic (age, gender, skin color, area of origin, epidemiological (permanence within an endemic zone, family history of Chagas heart disease or sudden death, physical strain, alcoholism, and smoking, and clinical (systemic hypertension variables were analyzed. The data set was assessed through single-variable and multivariate analysis. The two factors independently associated with heart disease were age - presence of heart disease being three times higher in patients over 60 years of age (odds ratio, OR: 2.89; confidence interval of 95%: 1.09-7.61 - and family history of Chagas heart disease (OR: 2.833, CI 95%: 1.11-7.23. Systemic hypertension and gender did not prove to hold any association with heart disease, as neither did skin color, but this variable showed low statistical power due to reduced sample size.

  18. CHARITY: Chagas cardiomyopathy bisoprolol intervention study: a randomized double-blind placebo force-titration controlled study with Bisoprolol in patients with chronic heart failure secondary to Chagas cardiomyopathy [NCT00323973

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    Casas Juan P

    2006-06-01

    Full Text Available Abstract Background Chagas' disease is the major cause of disability secondary to tropical diseases in young adults from Latin America, and around 20 million people are currently infected by T. cruzi. Heart failure due to Chagas cardiomyopathy is the main clinical presenation in Colombia. Heart failure due to Chagas' disease may respond to digoxin, diuretics and vasodilator therapy. Beta-adrenoreceptor antagonism seems to protect against the increased risk of cardiac arrhythmia and sudden death due to chronic sympathetic stimulation. The aim of this study is to evaluate the effects of the selective beta-adrenergic receptor blocker Bisoprolol on cardiovascular mortality, hospital readmission due to progressive heart failure and functional status in patients with heart failure secondary to Chagas' cardiomyopathy. Methods/design A cohort of 500 T. cruzi seropositive patients (250 per arm will be selected from several institutions in Colombia. During the pretreatment period an initial evaluation visit will be scheduled in which participants will sign consent forms and baseline measurements and tests will be conducted including blood pressure measurements, twelve-lead ECG and left ventricular ejection fraction assessment by 2D echocardiography. Quality of life questionnaire will be performed two weeks apart during baseline examination using the "Minnesota living with heart failure" questionnaire. A minimum of two 6 minutes corridor walk test once a week over a two-week period will be performed to measure functional class. During the treatment period patients will be randomly assigned to receive Bisoprolol or placebo, initially taking a total daily dose of 2.5 mgrs qd. The dose will be increased every two weeks to 5, 7.5 and 10 mgrs qd (maximum maintenance dose. Follow-up assessment will include clinical check-up, and blood collection for future measurements of inflammatory reactants and markers. Quality of life measurements will be obtained at six

  19. Chagas disease: current epidemiological trends after the interruption of vectorial and transfusional transmission in the Southern Cone countries.

    Science.gov (United States)

    Moncayo, Alvaro

    2003-07-01

    Chagas disease, named after Carlos Chagas who first described it in 1909, exists only on the American Continent. It is caused by a parasite, Trypanosoma cruzi, transmitted to humans by blood-sucking triatomine bugs and by blood transfusion. Chagas disease has two successive phases, acute and chronic. The acute phase lasts 6 to 8 weeks. After several years of starting the chronic phase, 20% to 35% of the infected individuals, depending on the geographical area will develop irreversible lesions of the autonomous nervous system in the heart, esophagus, colon and the peripheral nervous system. Data on the prevalence and distribution of Chagas disease improved in quality during the 1980's as a result of the demographically representative cross-sectional studies carried out in countries where accurate information was not available. A group of experts met in Bras lia in 1979 and devised standard protocols to carry out countrywide prevalence studies on human T. cruzi infection and triatomine house infestation. Thanks to a coordinated multi-country program in the Southern Cone countries the transmission of Chagas disease by vectors and by blood transfusion has been interrupted in Uruguay in1997, in Chile in 1999, and in 8 of the 12 endemic states of Brazil in 2000 and so the incidence of new infections by T. cruzi in the whole continent has decreased by 70%. Similar control multi-country initiatives have been launched in the Andean countries and in Central America and rapid progress has been recorded to ensure the interruption of the transmission of Chagas disease by 2005 as requested by a Resolution of the World Health Assembly approved in 1998. The cost-benefit analysis of the investments of the vector control program in Brazil indicate that there are savings of US$17 in medical care and disabilities for each dollar spent on prevention, showing that the program is a health investment with good return. Since the inception in 1979 of the Steering Committee on Chagas Disease

  20. Lineage Analysis of Circulating Trypanosoma cruzi Parasites and Their Association with Clinical Forms of Chagas Disease in Bolivia

    Science.gov (United States)

    del Puerto, Ramona; Nishizawa, Juan Eiki; Kikuchi, Mihoko; Iihoshi, Naomi; Roca, Yelin; Avilas, Cinthia; Gianella, Alberto; Lora, Javier; Gutierrez Velarde, Freddy Udalrico; Renjel, Luis Alberto; Miura, Sachio; Higo, Hiroo; Komiya, Norihiro; Maemura, Koji; Hirayama, Kenji

    2010-01-01

    Background The causative agent of Chagas disease, Trypanosoma cruzi, is divided into 6 Discrete Typing Units (DTU): Tc I, IIa, IIb, IIc, IId and IIe. In order to assess the relative pathogenicities of different DTUs, blood samples from three different clinical groups of chronic Chagas disease patients (indeterminate, cardiac, megacolon) from Bolivia were analyzed for their circulating parasites lineages using minicircle kinetoplast DNA polymorphism. Methods and Findings Between 2000 and 2007, patients sent to the Centro Nacional de Enfermedades Tropicales for diagnosis of Chagas from clinics and hospitals in Santa Cruz, Bolivia, were assessed by serology, cardiology and gastro-intestinal examinations. Additionally, patients who underwent colonectomies due to Chagasic magacolon at the Hospital Universitario Japonés were also included. A total of 306 chronic Chagas patients were defined by their clinical types (81 with cardiopathy, 150 without cardiopathy, 100 with megacolon, 144 without megacolon, 164 with cardiopathy or megacolon, 73 indeterminate and 17 cases with both cardiopathy and megacolon). DNA was extracted from 10 ml of peripheral venous blood for PCR analysis. The kinetoplast minicircle DNA (kDNA) was amplified from 196 out of 306 samples (64.1%), of which 104 (53.3%) were Tc IId, 4 (2.0%) Tc I, 7 (3.6%) Tc IIb, 1 (0.5%) Tc IIe, 26 (13.3%) Tc I/IId, 1 (0.5%) Tc I/IIb/IId, 2 (1.0%) Tc IIb/d and 51 (25.9%) were unidentified. Of the 133 Tc IId samples, three different kDNA hypervariable region patterns were detected; Mn (49.6%), TPK like (48.9%) and Bug-like (1.5%). There was no significant association between Tc types and clinical manifestations of disease. Conclusions None of the identified lineages or sublineages was significantly associated with any particular clinical manifestations in the chronic Chagas patients in Bolivia. PMID:20502516

  1. Histological and endoscopic features of the stomachs of patients with Chagas disease in the era of Helicobacter pylori

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    Fernanda Machado Fonseca

    2014-12-01

    Full Text Available Introduction Most studies that have evaluated the stomachs of patients with Chagas disease were performed before the discovery of Helicobacter pylori and used no control groups. This study compared the gastric features of chagasic and non-chagasic patients and assessed whether gastritis could be associated with Chagas disease. Methods Gastric biopsy samples were taken from patients who underwent endoscopy for histological analysis according to the Updated Sydney System. H. pylori infection was assessed by histology, 16S ribosomal ribonucleic acid (rRNA polymerase chain reaction (PCR, serology and the 13C-urea breath test. Patients were considered H. pylori-negative when all of these diagnostic tests were negative. Clinical and socio-demographic data were obtained by reviewing medical records and using a questionnaire. Results The prevalence of H. pylori infection (70.3% versus 71.7% and chronic gastritis (92.2% versus 85% was similar in the chagasic and non-chagasic groups, respectively; such as peptic ulcer, atrophy and intestinal metaplasia. Gastritis was associated with H. pylori infection independent of Chagas disease in a log-binomial regression model. However, the chagasic H. pylori-negative patients showed a significantly higher grade of mononuclear (in the corpus and polymorphonuclear (PMN (in the antrum cell infiltration. Additionally, the patients with the digestive form of Chagas disease showed a significantly lower prevalence of corpus atrophy than those with other clinical forms. Conclusions The prevalence of H. pylori infection and of gastric histological and endoscopic features was similar among the chagasic and non-chagasic patients. Additionally, this is the first controlled study to demonstrate that H. pylori is the major cause of gastritis in patients with Chagas disease.

  2. Globalização, iniqüidade e doença de Chagas Globalization, inequity and Chagas disease

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    João Carlos Pinto Dias

    2007-01-01

    Full Text Available A doença de Chagas (tripanossomíase americana, apresenta múltiplos aspectos sócio-culturais e político-econômicos que envolvem questões de iniqüidade e globalização. São relações presentes tanto nos processos de produção da doença como nas possibilidades de sua prevenção e manejo. Apesar da pobreza da região, envolvendo questões de iniqüidade e globalização, a doença tem sido controlada em várias áreas, o que reforça a auto-estima dos países. Para o futuro, problemas e desafios podem ser esperados, principalmente em termos da assistência médica para os indivíduos já infectados e da sustentação de uma vigilância epidemiológica permanente. Ambos estes pontos dependem de um melhor desempenho dos sistemas nacionais de saúde, principalmente em termos de sua competência e da superação de situações de iniqüidade. Particularmente, tem cabido à comunidade científica e acadêmica latino-americana um papel de grande destaque na implementação e sustentação de políticas de controle da doença, que hoje evoluíram para estratégias de ação compartida entre países, o que pode significar importante avanço no contexto político da região.Chagas disease (American trypanosomiasis bears a close relationship to multiple social and political aspects involving issues of globalization and inequity. Such relations concern the process of disease production and control in parallel with medical management. Despite the poverty in Latin America and various problems related to inequities and globalization, Chagas disease has been controlled in several areas, a fact that reinforces the countries' self-reliance. Several problems and challenges related to the disease can be expected in the future, mainly concerning medical care for already infected individuals and the sustainability of effective epidemiological surveillance. Both points depend heavily on improved performance by the national health systems, principally in

  3. Epidemiología de la enfermedad de Chagas en el estado de Veracruz Epidemiology of Chagas disease in the state of Veracruz

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    Elsa L Segura

    2005-06-01

    Full Text Available OBJETIVO: Identificar la seroprevalencia de enfermedad de Chagas, los factores de riesgo de la vivienda e índices entomológicos, para proponer medidas de control en 11 jurisdicciones sanitarias del estado de Veracruz. MATERIAL Y MÉTODOS: Entre 1997 y 2001 se hizo un estudio transversal cuya muestra quedó integrada por 281 localidades, 2 526 viviendas y 9 782 individuos. Se aplicó un cuestionario sobre factores de riesgo, se tomó sangre en papel filtro y se buscaron triatominos en el intra y peridomicilio. Se obtuvo la prevalencia de exposición a factores de riesgo y de seropositividad para la enfermedad. Se hizo análisis bivariado mediante la razón de momios, ji de Mantel y Haenszel e intervalo de confianza a 95% como prueba de significancia estadística. El análisis multivariado se hizo mediante la regresión logística no condicional y se incluyeron las variables que durante el análisis bivariado mostraron un valor de p hasta de 0.20. El impacto potencial se estimó con base en la fracción etiológica en expuestos. RESULTADOS: La prevalencia de enfermedad de Chagas fluctuó entre 0 y 2.8%. Las jurisdicciones con mayor riesgo fueron Tuxpan, Pánuco y Córdoba, y sin riesgo, Orizaba. Los principales factores de riesgo de la vivienda fueron el techo y muro de palma/zacate y piso de tierra, así como la presencia del vector y la ventilación. CONCLUSIONES: Es necesario realizar vigilancia epidemiológica basada en educación para la salud, mejoramiento de la vivienda y uso de insecticidas.OBJECTIVE: To assess the seroprevalence, household risk factors, and entomological indicators, in order to frame control measures in 11 Sanitary Jurisdictions of the state. MATERIAL AND METHODS: This study included 281 towns, 2 526 households, and 9782 individuals. Data were collected using a questionnaire. Blood was obtained in filter paper and a search for triatomines was conducted inside of and around dwellings. Prevalence rates were used to

  4. Clínica e terapêutica da doença de Chagas

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    Francisco S. Laranja

    1948-06-01

    Full Text Available 1 - Baseados na experiência adquirida nos últimos cinco anos em Bambuí, Minas Gerais, onde mais de seiscentos casos de doença de Chagas tém sido estudados, os autores fazem uma revisão das manifestações clínicas desta doença. mencionam alguns dados sôbre a incidência da esquizotripanose e chamam a atenção para a importância social desta moléstia. 2 - Sugerem a seguinte sistematização das fórmas clinicas da esquizotripanose: a Forma aguda; b Formas crônicas: 1 - Forma indeterminada (cardiacos potenciais, 2 - Forma cardíaca (cardiopatia crônica. Os autores não encontraram no material estudado em Bambuí casos classificaveis como forma nervosa crônica. 3 - Apresentam evidências de ordem clínica e experimental que justificam admitir-se a cardiopatia crônica da doença de Chagas como entidade clinica definida. 4 - As manifestações da infecção aguda são estudadas à luz da experiência adquirida com os 103 casos agudos diagnosticados em Bambuí. Dois tipos de fenômenos edematosos podem ocorrer em pacientes com esquizotripanose aguda: o edema local, de porta de entrada do parasito, e o edema generalizado (o chamado "mixedema". A patogenia dêste último é revista e sugere-se que ele seja devido a uma hipoproteinemia. O edema local parece de natureza inflamatória. As manifestações da cardiopatia aguda da doença de Chagas são descritas. Ritmo de galope, aumento da area cardíaca (em alguns casos devido a transudato pericárdico, prolongamento do espaço P-R, alterações primárias da onda T e extra-sístoles ventriculares - constituem os sinais mais importantes para o diagnóstico da cardiopatia aguda. Bloqueio de ramo direito foi encontrado em três casos fatais de cardiopatia aguda, um dos quais apresentou também pronunciado desnivelamento de ST (padrão de injúria. A morte durante a infecção aguda é usualmente precedida por manifestações convulsivas. Na maioria dos casos as manifestações, da infec

  5. Prion-like nanofibrils of small molecules (PriSM): A new frontier at the intersection of supramolecular chemistry and cell biology.

    Science.gov (United States)

    Zhou, Jie; Du, Xuewen; Xu, Bing

    2015-01-01

    Formed by non-covalent interactions and not defined at genetic level, the assemblies of small molecules in biology are complicated and less explored. A common morphology of the supramolecular assemblies of small molecules is nanofibrils, which coincidentally resembles the nanofibrils formed by proteins such as prions. So these supramolecular assemblies are termed as prion-like nanofibrils of small molecules (PriSM). Emerging evidence from several unrelated fields over the past decade implies the significance of PriSM in biology and medicine. This perspective aims to highlight some recent advances of the research on PriSM. This paper starts with description of the intriguing similarities between PriSM and prions, discusses the paradoxical features of PriSM, introduces the methods for elucidating the biological functions of PriSM, illustrates several examples of beneficial aspects of PriSM, and finishes with the promises and current challenges in the research of PriSM. We anticipate that the research of PriSM will contribute to the fundamental understanding at the intersection of supramolecular chemistry and cell biology and ultimately lead to a new paradigm of molecular (or supramolecular) therapeutics for biomedicine.

  6. Behaviour of concrete beams reinforced withFRP prestressed concrete prisms

    Science.gov (United States)

    Svecova, Dagmar

    The use of fibre reinforced plastics (FRP) to reinforce concrete is gaining acceptance. However, due to the relatively low modulus of FRP, in comparison to steel, such structures may, if sufficient amount of reinforcement is not used, suffer from large deformations and wide cracks. FRP is generally more suited for prestressing. Since it is not feasible to prestress all concrete structures to eliminate the large deflections of FRP reinforced concrete flexural members, researchers are focusing on other strategies. A simple method for avoiding excessive deflections is to provide sufficiently high amount of FRP reinforcement to limit its stress (strain) to acceptable levels under service loads. This approach will not be able to take advantage of the high strength of FRP and will be generally uneconomical. The current investigation focuses on the feasibility of an alternative strategy. This thesis deals with the flexural and shear behaviour of concrete beams reinforced with FRP prestressed concrete prisms. FRP prestressed concrete prisms (PCP) are new reinforcing bars, made by pretensioning FRP and embedding it in high strength grout/concrete. The purpose of the research is to investigate the feasibility of using such pretensioned rebars, and their effect on the flexural and shear behaviour of reinforced concrete beams over the entire loading range. Due to the prestress in the prisms, deflection of concrete beams reinforced with this product is substantially reduced, and is comparable to similarly steel reinforced beams. The thesis comprises both theoretical and experimental investigations. In the experimental part, nine beams reinforced with FRP prestressed concrete prisms, and two companion beams, one steel and one FRP reinforced were tested. All the beams were designed to carry the same ultimate moment. Excellent flexural and shear behaviour of beams reinforced with higher prestressed prisms is reported. When comparing deflections of three beams designed to have the

  7. Cardiac beta-receptors in experimental Chagas' disease Receptores beta cardíacos na doença de Chagas experimental

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    Julio E. Enders

    1995-02-01

    Full Text Available Experimental Chagas' disease (45 to 90 days post-infection showed serious cardiac alterations in the contractility and in the pharmacological response to beta adrenergic receptors in normal and T. cruzi infected mice (post-acute phase. Chagasic infection did not change the beta receptors density (78.591 ± 3.125 fmol/mg protein and 73.647 ± 2.194 fmol/mg protein for controls but their affinity was significantly diminished (Kd = 7.299 ± 0.426 nM and Kd = 3.759 ± 0.212 nM for the control p Estudaram-se os receptores beta cardíacos de camundongos infectados pelo Trypanosoma cruzi na fase pós-aguda da doença de Chagas para estabelecer em que medida os mesmos contribuem a gerar respostas anômalas às catecolaminas observadas nestes miocardios. Utilizara-se 3-H/DHA para a marcação dos receptores beta cardíacos dos camundongos normais e dos infectados na fase pós-aguda (45 a 90 dias pós-infecção. O número dos sítios de fixação foi similar nos dois grupos, 78.591 ± 3.125 fmol/mg. Proteína nos chagásicos e 73.647 ± 2.194 fmol/mg. Proteína no grupo controle. Em vez disso, a afinidade verificou-se significativamente diminuida no grupo chagásico (Kd = 7.299 ± 0.426 nM respeito do controle (Kd = 3.759 ± 0.212 nM p < 0.001. Os resultados obtidos demonstram que as modificações observadas na estimulação adrenérgica do miocárdio chagásico se correlacionam com a menor afinidade dos receptores beta cardíacos e que estas alterações exerceriam uma parte determinante para as consequências funcionais que são detectadas na fase crônica.

  8. Inoculação experimental de Equus asinus com Leishmania chagasi Cunha & Chagas, 1937 Experimental infection of Equus asinus with Leishmania chagasi Cunha & Chagas, 1937

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    Elúzio José Lima Cerqueira

    2003-12-01

    Full Text Available Quatro Equus asinus foram inoculados com promastigotas de Leishmania chagasi Cunha & Chagas, 1937 e acompanhados durante 12 meses através de: pesquisa de amastigotas em esfregaços e culturas de sangue periférico em fragmentos de tecido do lábio inferior, medula óssea, baço e fígado e de testes de ELISA e TRALd. Estes foram positivos nos 8º, 10º e 12º meses após a inoculação. O exame histopatológico pós necropsia, demonstrou discreto número de amastigotas no fígado de dois dos eqüídeos inoculados. Apesar de desafiados com elevado número de promastigotas, os animais não desenvolveram infecções patentes e não infectaram experimentalmente a vetora Lutzomya longipalpis. Os resultados induzem a acreditar que os eqüídeos são desprovidos de importância como reservatórios na cadeia de transmissão da leishmaniose visceral, embora sirvam como boa fonte de alimentação sangüínea e proliferação da vetora Lutzomyia longipalpis.Four Equus asinus were challenged with promastigotes of Leishmania chagasi Cunha & Chagas, 1937, and followed up for 12 months. They were observed by means of direct testing for promastigotes in smears and culture of peripheral blood, fragments from inferior lip, bone marrow, spleen and liver and the immunological assays ELISA and TRALd. The post-necropsy histological examination demonstrated a small number of amastigotes in the liver of two animals. ELISA and TRALd tests were positive at the 8th, 10th and 12th month after inoculation. The results suggest that the donkeys were able to overcome the experimental leishmanial infection and did not infect the vector Lutzomyia longipalpis in the laboratory. Consequently they can not be considered an important reservoir in the epidemiological chain of transmission of visceral leishmaniasis, although they represent an important blood source for the vector and its proliferation.

  9. Post-cracking behavior of blocks, prisms, and small concrete walls reinforced with plant fiber

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    I. I. Soto

    Full Text Available Structural masonry using concrete blocks promotes the rationalization of construction projects, lowering the final cost of a building through the elimination of forms and the reduction of the consumption of reinforcement bars. Moreover, production of a block containing a combination of concrete and vegetable fiber sisal results in a unit with properties such as mechanical strength, stiffness, flexibility, ability to absorb energy, and post-cracking behavior that are comparable to those of a block produced with plain concrete. Herein are reported the results of a study on the post-cracking behavior of blocks, prisms, and small walls reinforced with sisal fibers (lengths of 20 mm and 40 mm added at volume fractions of 0.5% and 1%. Tests were performed to characterize the fibers and blocks and to determine the compressive strength of the units, prisms, and small walls. The deformation modulus of the elements was calculated and the stress-strain curves were plotted to gain a better understanding of the values obtained. The compression test results for the small walls reinforced with fibers were similar to those of the reference walls and better than the blocks and prisms with added fibers, which had resistances lower than those of the corresponding conventional materials. All elements prepared with the addition of sisal exhibited an increase in the deformation capacity (conferred by the fibers, which was observed in the stress-strain curves. The failure mode of the reference elements was characterized by an abrupt fracture, whereas the reinforced elements underwent ductile breakage. This result was because of the presence of the fibers, which remained attached to the faces of the cracks via adhesion to the cement matrix, thus preventing loss of continuity in the material. Therefore, the cement/plant fiber composites are advantageous in terms of their ductility and ability to resist further damage after cracking.

  10. Using brain potentials to understand prism adaptation: the error-related negativity and the P300

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    Stephane Joseph Maclean

    2015-06-01

    Full Text Available Prism adaptation (PA is both a perceptual-motor learning task as well as a promising rehabilitation tool for visuo-spatial neglect (VSN – a spatial attention disorder often experienced after stroke resulting in slowed and/or inaccurate motor responses to contralesional targets. During PA, individuals are exposed to prism-induced shifts of the visual-field while performing a visuo-guided reaching task. After adaptation, with goggles removed, visuo-motor responding is shifted to the opposite direction of that initially induced by the prisms. This visuo-motor aftereffect has been used to study visuo-motor learning and adaptation and has been applied clinically to reduce VSN severity by improving motor responding to stimuli in contralesional (usually left-sided space. In order to optimize PA’s use for VSN patients, it is important to elucidate the neural and cognitive processes that alter visuomotor function during PA. In the present study, healthy young adults underwent PA while event-related potentials (ERPs were recorded at the termination of each reach (screen-touch, then binned according to accuracy (hit vs. miss and phase of exposure block (early, middle, late. Results show that two ERP components were evoked by screen-touch: an early error-related negativity (ERN, and a P300. The ERN was consistently evoked on miss trials during adaptation, while the P300 amplitude was largest during the early phase of adaptation for both hit and miss trials. This study provides evidence of two neural signals sensitive to visual feedback during PA that may sub-serve changes in visuomotor responding. Prior ERP research suggests that the ERN reflects an error processing system in medial-frontal cortex, while the P300 is suggested to reflect a system for context updating and learning. Future research is needed to elucidate the role of these ERP components in improving visuomotor responses among individuals with VSN.

  11. Using brain potentials to understand prism adaptation: the error-related negativity and the P300.

    Science.gov (United States)

    MacLean, Stephane J; Hassall, Cameron D; Ishigami, Yoko; Krigolson, Olav E; Eskes, Gail A

    2015-01-01

    Prism adaptation (PA) is both a perceptual-motor learning task as well as a promising rehabilitation tool for visuo-spatial neglect (VSN)-a spatial attention disorder often experienced after stroke resulting in slowed and/or inaccurate motor responses to contralesional targets. During PA, individuals are exposed to prism-induced shifts of the visual-field while performing a visuo-guided reaching task. After adaptation, with goggles removed, visuomotor responding is shifted to the opposite direction of that initially induced by the prisms. This visuomotor aftereffect has been used to study visuomotor learning and adaptation and has been applied clinically to reduce VSN severity by improving motor responding to stimuli in contralesional (usually left-sided) space. In order to optimize PA's use for VSN patients, it is important to elucidate the neural and cognitive processes that alter visuomotor function during PA. In the present study, healthy young adults underwent PA while event-related potentials (ERPs) were recorded at the termination of each reach (screen-touch), then binned according to accuracy (hit vs. miss) and phase of exposure block (early, middle, late). Results show that two ERP components were evoked by screen-touch: an error-related negativity (ERN), and a P300. The ERN was consistently evoked on miss trials during adaptation, while the P300 amplitude was largest during the early phase of adaptation for both hit and miss trials. This study provides evidence of two neural signals sensitive to visual feedback during PA that may sub-serve changes in visuomotor responding. Prior ERP research suggests that the ERN reflects an error processing system in medial-frontal cortex, while the P300 is suggested to reflect a system for context updating and learning. Future research is needed to elucidate the role of these ERP components in improving visuomotor responses among individuals with VSN.

  12. Intravesicular Phosphatase PHOSPHO1 Function in Enamel Mineralization and Prism Formation

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    Mirali Pandya

    2017-10-01

    Full Text Available The transport of mineral ions from the enamel organ-associated blood vessels to the developing enamel crystals involves complex cargo packaging and carriage mechanisms across several cell layers, including the ameloblast layer and the stratum intermedium. Previous studies have established PHOSPHO1 as a matrix vesicle membrane-associated phosphatase that interacts with matrix vesicles molecules phosphoethanolamine and phosphocholine to initiate apatite crystal formation inside of matrix vesicles in bone. In the present study, we sought to determine the function of Phospho1 during amelogenesis. PHOSPHO1 protein localization during amelogenesis was verified using immunohistochemistry, with positive signals in the enamel layer, ameloblast Tomes' processes, and in the walls of ameloblast secretory vesicles. These ameloblast secretory vesicle walls were also labeled for amelogenin and the exosomal protein marker HSP70 using immunohistochemistry. Furthermore, PHOSPHO1 presence in the enamel organ was confirmed by Western blot. Phospho1−/− mice lacked sharp incisal tips, featured a significant 25% increase in total enamel volume, and demonstrated a significant 2-fold reduction in silver grain density of von Kossa stained ground sections indicative of reduced mineralization in the enamel layer when compared to wild-type mice (p < 0.001. Scanning electron micrographs of Phospho1−/− mouse enamel revealed a loss of the prominent enamel prism “picket fence” structure, a loss of parallel crystal organization within prisms, and a 1.56-fold increase in enamel prism width (p < 0.0001. Finally, EDS elemental analysis demonstrated a significant decrease in phosphate incorporation in the enamel layer when compared to controls (p < 0.05. Together, these data establish that the matrix vesicle membrane-associated phosphatase PHOSPHO1 is essential for physiological enamel mineralization. Our findings also suggest that intracellular ameloblast secretory

  13. High-performance beam steering using electrowetting-driven liquid prism fabricated by a simple dip-coating method

    Energy Technology Data Exchange (ETDEWEB)

    Enrico Clement, Carlos; Park, Sung-Yong, E-mail: mpeps@nus.edu.sg [Department of Mechanical Engineering, National University of Singapore, Block EA, #07-08, 9 Engineering Drive 1, 117576 (Singapore)

    2016-05-09

    A high degree of beam steering is demonstrated using an electrowetting-driven liquid prism. While prism devices have typically relied on complex and expensive laboratory setups, such as high-vacuum facilities for fabrication of dielectric layers, this work utilizes a simple dip-coating method to provide an ion gel layer as a dielectric, offering 2 or 3 orders higher specific capacitance (c ≈ 10 μF/cm{sup 2}) than that of conventional dielectrics. Analytical studies present the effects of liquid selection and arrangement on overall prism performance. For experimental demonstrations of high-performance beam steering, we not only selected two immiscible liquids of water and 1-bromonaphthalene (1-BN) oil which provide the large refractive index difference (n{sub water} = 1.33 and n{sub 1-BN} = 1.65 at λ = 532 nm) between them, but also utilized a double-stacked prism configuration which increases the number of interfaces for incoming light to be steered. At a prism apex angle of φ = 27°, we were able to achieve significantly large beam steering of up to β = 19.06°, which is the highest beam steering performance ever demonstrated using electrowetting technology.

  14. Multisensory and Modality-Specific Influences on Adaptation to Optical Prisms

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    Elena Calzolari

    2017-11-01

    Full Text Available Visuo-motor adaptation to optical prisms displacing the visual scene (prism adaptation, PA is a method used for investigating visuo-motor plasticity in healthy individuals and, in clinical settings, for the rehabilitation of unilateral spatial neglect. In the standard paradigm, the adaptation phase involves repeated pointings to visual targets, while wearing optical prisms displacing the visual scene laterally. Here we explored differences in PA, and its aftereffects (AEs, as related to the sensory modality of the target. Visual, auditory, and multisensory – audio-visual – targets in the adaptation phase were used, while participants wore prisms displacing the visual field rightward by 10°. Proprioceptive, visual, visual-proprioceptive, auditory-proprioceptive straight-ahead shifts were measured. Pointing to auditory and to audio-visual targets in the adaptation phase produces proprioceptive, visual-proprioceptive, and auditory-proprioceptive AEs, as the typical visual targets did. This finding reveals that cross-modal plasticity effects involve both the auditory and the visual modality, and their interactions (Experiment 1. Even a shortened PA phase, requiring only 24 pointings to visual and audio-visual targets (Experiment 2, is sufficient to bring about AEs, as compared to the standard 92-pointings procedure. Finally, pointings to auditory targets cause AEs, although PA with a reduced number of pointings (24 to auditory targets brings about smaller AEs, as compared to the 92-pointings procedure (Experiment 3. Together, results from the three experiments extend to the auditory modality the sensorimotor plasticity underlying the typical AEs produced by PA to visual targets. Importantly, PA to auditory targets appears characterized by less accurate pointings and error correction, suggesting that the auditory component of the PA process may be less central to the building up of the AEs, than the sensorimotor pointing activity per se. These

  15. The Implementation of Cumulative Learning Theory in Calculating Triangular Prism and Tube Volumes

    Science.gov (United States)

    Muklis, M.; Abidin, C.; Pamungkas, M. D.; Masriyah

    2018-01-01

    This study aims at describing the application of cumulative learning theory in calculating the volume of a triangular prism and a tube as well as revealing the students’ responses toward the learning. The research method used was descriptive qualitative with elementary school students as the subjects of the research. Data obtained through observation, field notes, questionnaire, tests, and interviews. The results from the application of cumulative learning theory obtained positive students’ responses in following the learning and students’ learning outcomes was dominantly above the average. This showed that cumulative learning could be used as a reference to be implemented in learning, so as to improve the students’ achievement.

  16. Compact surface plasmon resonance biosensor utilizing an injection-molded prism

    Science.gov (United States)

    Chen, How-Foo; Chen, Chih-Han; Chang, Yun-Hsiang; Chuang, Hsin-Yuan

    2016-05-01

    Targeting at a low cost and accessible diagnostic device in clinical practice, a compact surface plasmon resonance (SPR) biosensor with a large dynamic range in high sensitivity is designed to satisfy commercial needs in food safety, environmental bio-pollution monitoring, and fast clinical diagnosis. The core component integrates an optical coupler, a sample-loading plate, and angle-tuning reflectors is injection-molded as a free-from prism made of plastic optics. This design makes a matching-oil-free operation during operation. The disposability of this low-cost component ensures testing or diagnosis without cross contamination in bio-samples.

  17. PRISM (Polarized Radiation Imaging and Spectroscopy Mission): an extended white paper

    Energy Technology Data Exchange (ETDEWEB)

    André, Philippe [Laboratoire d' Astrophysique de Paris-Saclay, Gif-sur-Yvette Cedex (France); Baccigalupi, Carlo; Bielewicz, Pawel [SISSA, Via Bonomea 265, 34136, Trieste (Italy); Banday, Anthony [Université de Toulouse, UPS-OMP, IRAP, F-31028 Toulouse cedex 4 (France); Barbosa, Domingos [Grupo de Radio Astronomia Basic Sciences and Enabling Technologies Instituto de Telecomunicações, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Barreiro, Belen [Instituto de Fìsica de Cantabria (CSIC-Universidad de Cantabria) Avda. de los Castros s/n, 39005 Santander (Spain); Bartlett, James [APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/lrfu, Observatoire de Paris, Sorbonne Paris, Cité, 10, rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); Bartolo, Nicola [Dipartimento di Fisica e Astronomia ' ' G. Galilei" , Università degli studi di Padova, via Marzolo 8, I-35131, Padova (Italy); Battistelli, Elia [Dipartimento di Fisica, Università di Roma La Sapienza, P.le A. Moro 2, 00185 Roma (Italy); Battye, Richard; Bonaldi, Anna [Jordell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Bendo, George [U.K. ALMA Regional Centre Node, Jordell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Benoȋt, Alain [Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Bernard, Jean-Philippe [CNRS, IRAP, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4 (France); Bersanelli, Marco [Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria, 16, Milano (Italy); Béthermin, Matthieu, E-mail: naselsky@nbi.dk [European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching (Germany); and others

    2014-02-01

    PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to ESA in May 2013 as a large-class mission for investigating within the framework of the ESA Cosmic Vision program a set of important scientific questions that require high resolution, high sensitivity, full-sky observations of the sky emission at wavelengths ranging from millimeter-wave to the far-infrared. PRISM's main objective is to explore the distant universe, probing cosmic history from very early times until now as well as the structures, distribution of matter, and velocity flows throughout our Hubble volume. PRISM will survey the full sky in a large number of frequency bands in both intensity and polarization and will measure the absolute spectrum of sky emission more than three orders of magnitude better than COBE FIRAS. The data obtained will allow us to precisely measure the absolute sky brightness and polarization of all the components of the sky emission in the observed frequency range, separating the primordial and extragalactic components cleanly from the galactic and zodiacal light emissions. The aim of this Extended White Paper is to provide a more detailed overview of the highlights of the new science that will be made possible by PRISM, which include: (1) the ultimate galaxy cluster survey using the Sunyaev-Zeldovich (SZ) effect, detecting approximately 10{sup 6} clusters extending to large redshift, including a characterization of the gas temperature of the brightest ones (through the relativistic corrections to the classic SZ template) as well as a peculiar velocity survey using the kinetic SZ effect that comprises our entire Hubble volume; (2) a detailed characterization of the properties and evolution of dusty galaxies, where the most of the star formation in the universe took place, the faintest population of which constitute the diffuse CIB (Cosmic Infrared Background); (3) a characterization of the B modes from primordial gravity waves generated during

  18. Calculation of gravity and magnetic anomalies of finite-length right polygonal prisms.

    Science.gov (United States)

    Cady, J.W.

    1980-01-01

    An equation is derived for the vertical gravity field due to a homogeneous body with polygonal cross‐section and finite strike‐length. The equation can be separated into the two‐dimensional (2-D) terms of Talwani et al. (1959) and exact terms for the contributions of the ends of the prism. Equations for the magnetic field due to a similar body were derived by Shuey and Pasquale (1973), who coined the term “two‐and‐a‐half dimensional” (2 1/2-D) to describe the geometry. Magnetic intensities are expressed as a vector sum, from which the common dot product formulation can be obtained by binomial expansion.

  19. Note: Using a Kösters prism to create a fringe pattern.

    Science.gov (United States)

    Capellmann, R F; Bewerunge, J; Platten, F; Egelhaaf, S U

    2017-05-01

    The interference of two crossed laser beams results in a standing wave. Such fringe patterns are exploited in different instruments such as interferometers or laser-Doppler anemometers. We create a fringe pattern in the sample plane of a microscope using a compact apparatus based on a Kösters prism. The fringe pattern is shown to be spatially and temporally very stable, covers a large area, and its spacing is easily tunable. In addition, we exploit it to impose a sinusoidal potential on colloidal particles.

  20. Evaluation of postulated LOF [loss-of-flow] events in PRISM and SAFR

    International Nuclear Information System (INIS)

    Chan, B.C.; Van Tuyle, G.J.; Slovik, G.C.; Aronson, A.L.

    1987-01-01

    The PRISM and SAFR designs, as currently proposed by DOE, are designed for ''inherent'', as opposed to ''engineered'', safety. Brookhaven National Laboratory is supporting the initial NRC review of these advanced LMR concepts. A loss-of-flow (LOF) accident coupled with a failure of the reactor shutdown system is one of the major safety concerns in the advanced liquid metal reactor (LMR) evaluation effort. The analysis discussed here covers: (1) primary pipe break without pump trip, (2) primary coolant pump seizure, and (3) primary coolant pump coastdown. The analytical modelling and the calculated thermal and hydraulic behavior are described in detail

  1. Simplified analysis of PRISM RVACS [Reactor Vessel Auxiliary Cooling System] performance without liner spill-over

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.

    1990-01-01

    Simplified analysis of the performance of the PRISM RVACS decay heat removal system under off-normal conditions, i.e., without the liner spill-over, is described. Without the spilling of hot-pool sodium over the liner and the resultant down-flow along the inside of the reactor vessel wall, the RVACS system performance becomes dominated by the radial heat condition and radiation. Simple estimates of the resulting heat conduction and radiation processes support GE's contention that the RVACS performance is not severely impacted by the absence of spillover, and can improve significantly if sodium has leaked into the region between the reactor and containment vessels. 7 refs

  2. The eclipse of CI Cygni in 1980 on the objective prism spectra

    International Nuclear Information System (INIS)

    Mikolajewska, J.; Mikolajewski, M.

    1982-01-01

    The observations of CI Cyg were carried out with the Torun 60/90 cm Schmidt telescope with the objective prism giving a dispersion of 250 A/mm at H-gamma. Intensity traces of 20 selected spectra, made on the Kodak IIa-O plates, were made. The results were corrected for all instrumental effects and the interstellar extinction. The relative emission lines intensities have been obtained from the tracings after normalization to H-beta = 100. The spectra were typical for the quiet symbiotic star. So, all changes in the spectrum were caused by geometrical effects (eclipse). A preliminary analysis of the obtained spectra is presented. (Auth.)

  3. Association of L-ficolin levels and FCN2 genotypes with chronic Chagas disease.

    Directory of Open Access Journals (Sweden)

    Paola R Luz

    Full Text Available BACKGROUND: L-ficolin (encoded by FCN2 binds to acetylated sugar moieties of many pathogens, including Trypanosoma cruzi, promoting their phagocytosis and lysis by the complement system. METHODS: We investigated L-ficolin levels in 160 T. cruzi infected patients with chronic Chagas disease and 71 healthy individuals, and FCN2 polymorphisms (-986 G>A, -602 G>A, and -4 A>G in the promoter and A258S in exon 8 in 243 patients, being 88 indeterminate (asymptomatic, 96 with cardiac, 23 with digestive and 33 with cardiodigestive manifestations (two were unspecified and 305 controls (135 for A258S. RESULTS: Patients presented lower L-ficolin plasma levels than controls (p<0.0001. Among the different groups of cardiac commitment, individuals with moderate forms had higher L-ficolin levels than the severe forms (P = 0.039. Lower L-ficolin levels were found associated with the 258S variant in the patients (P = 0.034. We found less -4A/G heterozygotes in the cardiac patients, than in the controls (OR = 0.56 [95% CI = 0.33-0.94], P = 0.034. Heterozygote -4A/G genotypes with the 258S variant and 258SS homozygotes were nevertheless more frequent among cardiodigestive patients than in controls (OR = 14.1 [95% CI = 3.5-56.8], P = 0.0001 and in indeterminate patients (OR = 3.2 [95% CI = 1.1-9.4], P = 0.037. We also found an association of the allelic frequency of the 258S variant with cardiodigestive Chagas disease compared to controls (OR = 2.24 [95% CI = 1.1-4.5], P = 0.037. Thus, decreased patient levels of L-ficolin reflect not only protein consumption due to the disease process, but also the higher frequency of the 258S variant in patients with cardiodigestive symptoms. CONCLUSION: The very first study on Brazilian cohort associates both L-ficolin plasma levels and FCN2 variants to Chagas disease and subsequent disease progression. The prognostic value of L-ficolin levels and the FCN2*A258S polymorphism

  4. A field trial of alternative targeted screening strategies for Chagas disease in Arequipa, Peru.

    Directory of Open Access Journals (Sweden)

    Gabrielle C Hunter

    2012-01-01

    Full Text Available Chagas disease is endemic in the rural areas of southern Peru and a growing urban problem in the regional capital of Arequipa, population ∼860,000. It is unclear how to implement cost-effective screening programs across a large urban and periurban environment.We compared four alternative screening strategies in 18 periurban communities, testing individuals in houses with 1 infected vectors; 2 high vector densities; 3 low vector densities; and 4 no vectors. Vector data were obtained from routine Ministry of Health insecticide application campaigns. We performed ring case detection (radius of 15 m around seropositive individuals, and collected data on costs of implementation for each strategy.Infection was detected in 21 of 923 (2.28% participants. Cases had lived more time on average in rural places than non-cases (7.20 years versus 3.31 years, respectively. Significant risk factors on univariate logistic regression for infection were age (OR 1.02; p = 0.041, time lived in a rural location (OR 1.04; p = 0.022, and time lived in an infested area (OR 1.04; p = 0.008. No multivariate model with these variables fit the data better than a simple model including only the time lived in an area with triatomine bugs. There was no significant difference in prevalence across the screening strategies; however a self-assessment of disease risk may have biased participation, inflating prevalence among residents of houses where no infestation was detected. Testing houses with infected-vectors was least expensive. Ring case detection yielded four secondary cases in only one community, possibly due to vector-borne transmission in this community, apparently absent in the others.Targeted screening for urban Chagas disease is promising in areas with ongoing vector-borne transmission; however, these pockets of epidemic transmission remain difficult to detect a priori. The flexibility to adapt to the epidemiology that emerges during screening is key to

  5. A Field Trial of Alternative Targeted Screening Strategies for Chagas Disease in Arequipa, Peru

    Science.gov (United States)

    Hunter, Gabrielle C.; Borrini-Mayorí, Katty; Ancca Juárez, Jenny; Castillo Neyra, Ricardo; Verastegui, Manuela R.; Malaga Chavez, Fernando S.; Cornejo del Carpio, Juan Geny; Córdova Benzaquen, Eleazar; Náquira, César; Gilman, Robert H.; Bern, Caryn; Levy, Michael Z.

    2012-01-01

    Background Chagas disease is endemic in the rural areas of southern Peru and a growing urban problem in the regional capital of Arequipa, population ∼860,000. It is unclear how to implement cost-effective screening programs across a large urban and periurban environment. Methods We compared four alternative screening strategies in 18 periurban communities, testing individuals in houses with 1) infected vectors; 2) high vector densities; 3) low vector densities; and 4) no vectors. Vector data were obtained from routine Ministry of Health insecticide application campaigns. We performed ring case detection (radius of 15 m) around seropositive individuals, and collected data on costs of implementation for each strategy. Results Infection was detected in 21 of 923 (2.28%) participants. Cases had lived more time on average in rural places than non-cases (7.20 years versus 3.31 years, respectively). Significant risk factors on univariate logistic regression for infection were age (OR 1.02; p = 0.041), time lived in a rural location (OR 1.04; p = 0.022), and time lived in an infested area (OR 1.04; p = 0.008). No multivariate model with these variables fit the data better than a simple model including only the time lived in an area with triatomine bugs. There was no significant difference in prevalence across the screening strategies; however a self-assessment of disease risk may have biased participation, inflating prevalence among residents of houses where no infestation was detected. Testing houses with infected-vectors was least expensive. Ring case detection yielded four secondary cases in only one community, possibly due to vector-borne transmission in this community, apparently absent in the others. Conclusions Targeted screening for urban Chagas disease is promising in areas with ongoing vector-borne transmission; however, these pockets of epidemic transmission remain difficult to detect a priori. The flexibility to adapt to the epidemiology that

  6. Chagas disease in an area of recent occupation in Cochabamba, Bolivia

    Directory of Open Access Journals (Sweden)

    Albarracin-Veizaga Hugo

    1999-01-01

    Full Text Available INTRODUCTION: A descriptive, entomological and seroepidemiological study on Chagas disease was conducted in a place of recent occupation on the outskirts of Cochabamba, Bolivia: Avaroa/Primer de Mayo (population:3,000, where the socio-economic level is low and no control measures have been made available. METHODS: The immunofluorescent antibody test (IFAT was used for IgG and IgM anti-Trypanosoma cruzi antibodies in filter paper bloodspot eluates from 128 subjects (73 females, 55 males selected by systematic sampling. Concerning each subject age, gender, birthplace, occupation, duration of residence and building materials used in their houses were recorded. Vectors were captured both in domestic and peridomestic environments. RESULTS: Seropositive, 12.5% (16/128: females, 15.1% (11/73; males, 9.1% (5/55. Average time of residence: 6.1 years for the whole population sample and 7.4 years for the seropositive subjects. Most houses had adobe walls (76.7% , n= 30, galvanized iron rooves (86.7% and earthen floors (53.4% 80% of the walls had crevices. One hundred forty seven specimens of Triatoma infestans were captured, of which 104 (70.7% were domestic, and 1 peridomestic Triatoma sordida. Precipitin host identification: birds, 67.5%; humans, 27.8%; rodents, 11.9%; dogs, 8.7%; cats, 1.6%. House infestation and density indices were 53.3 and 493.0 respectively. We found 21 (14.3% specimens of T. infestans infected with trypanosomes, 18 (85.7% of which in domestic environments. DISCUSSION: The elements for the vector transmission of Chagas disease are present in Avaroa/Primer de Mayo and the ancient custom of keeping guinea pigs indoors adds to the risk of human infection. In neighboring Cochabamba, due to substandard quality control, contaminated blood transfusions are not infrequent, which further aggravates the spread of Chagas disease. Prompt action to check the transmission of this infection, involving additionally the congenital and transfusional

  7. Modeling horizontal gene transfer (HGT in the gut of the Chagas disease vector Rhodnius prolixus

    Directory of Open Access Journals (Sweden)

    Durvasula Ravi V

    2011-05-01

    Full Text Available Abstract Background Paratransgenesis is an approach to reducing arthropod vector competence using genetically modified symbionts. When applied to control of Chagas disease, the symbiont bacterium Rhodococcus rhodnii, resident in the gut lumen of the triatomine vector Rhodnius prolixus (Hemiptera: Reduviidae, is transformed to export cecropin A, an insect immune peptide. Cecropin A is active against Trypanosoma cruzi, the causative agent of Chagas disease. While proof of concept has been achieved in laboratory studies, a rigorous and comprehensive risk assessment is required prior to consideration of field release. An important part of this assessment involves estimating probability of transgene horizontal transfer to environmental organisms (HGT. This article presents a two-part risk assessment methodology: a theoretical model predicting HGT in the gut of R. prolixus from the genetically transformed symbiont R. rhodnii to a closely related non-target bacterium, Gordona rubropertinctus, in the absence of selection pressure, and a series of laboratory trials designed to test the model. Results The model predicted an HGT frequency of less than 1.14 × 10-16 per 100,000 generations at the 99% certainty level. The model was iterated twenty times, with the mean of the ten highest outputs evaluated at the 99% certainty level. Laboratory trials indicated no horizontal gene transfer, supporting the conclusions of the model. Conclusions The model treats HGT as a composite event, the probability of which is determined by the joint probability of three independent events: gene transfer through the modalities of transformation, transduction, and conjugation. Genes are represented in matrices and Monte Carlo method and Markov chain analysis are used to simulate and evaluate environmental conditions. The model is intended as a risk assessment instrument and predicts HGT frequency of less than 1.14 × 10-16 per 100,000 generations. With laboratory studies that

  8. Accuracy of chimeric proteins in the serological diagnosis of chronic chagas disease - a Phase II study.

    Directory of Open Access Journals (Sweden)

    Fred Luciano Neves Santos

    2017-03-01

    Full Text Available The performance of current serologic tests for diagnosing chronic Chagas disease (CD is highly variable. The search for new diagnostic markers has been a constant challenge for improving accuracy and reducing the number of inconclusive results.Here, four chimeric proteins (IBMP-8.1 to -8.4 comprising immunodominant regions of different Trypanosoma cruzi antigens were tested by enzyme-linked immunosorbent assay. The proteins were used to detect specific anti-T. cruzi antibodies in the sera of 857 chagasic and 689 non-chagasic individuals to evaluate their accuracy for chronic CD diagnosis. The antigens were recombinantly expressed in Escherichia coli and purified by chromatographic methods. The sensitivity and specificity values ranged from 94.3% to 99.3% and 99.4% to 100%, respectively. The diagnostic odds ratio (DOR values were 6,462 for IBMP-8.1, 3,807 for IBMP-8.2, 32,095 for IBMP-8.3, and 283,714 for IBMP-8.4. These chimeric antigens presented DORs that were higher than the commercial test Pathozyme Chagas. The antigens IBMP-8.3 and -8.4 also showed DORs higher than the Gold ELISA Chagas test. Mixtures with equimolar concentrations were tested in order to improve the diagnosis accuracy of negative samples with high signal and positive samples with low signal. However, no gain in accuracy was observed relative to the individual antigens. A total of 1,079 additional sera were used to test cross-reactivity to unrelated diseases. The cross-reactivity rates ranged from 0.37% to 0.74% even for Leishmania spp., a pathogen showing relatively high genome sequence identity to T. cruzi. Imprecision analyses showed that IBMP chimeras are very stable and the results are highly reproducible.Our findings indicate that the IBMP-8.4 antigen can be safely used in serological tests for T. cruzi screening in blood banks and for chronic CD laboratory diagnosis.

  9. Antigenicity and diagnostic potential of vaccine candidates in human Chagas disease.

    Directory of Open Access Journals (Sweden)

    Shivali Gupta

    Full Text Available Chagas disease, caused by Trypanosoma cruzi, is endemic in Latin America and an emerging infectious disease in the US and Europe. We have shown TcG1, TcG2, and TcG4 antigens elicit protective immunity to T. cruzi in mice and dogs. Herein, we investigated antigenicity of the recombinant proteins in humans to determine their potential utility for the development of next generation diagnostics for screening of T. cruzi infection and Chagas disease.Sera samples from inhabitants of the endemic areas of Argentina-Bolivia and Mexico-Guatemala were analyzed in 1(st-phase for anti-T. cruzi antibody response by traditional serology tests; and in 2(nd-phase for antibody response to the recombinant antigens (individually or mixed by an ELISA. We noted similar antibody response to candidate antigens in sera samples from inhabitants of Argentina and Mexico (n=175. The IgG antibodies to TcG1, TcG2, and TcG4 (individually and TcG(mix were present in 62-71%, 65-78% and 72-82%, and 89-93% of the subjects, respectively, identified to be seropositive by traditional serology. Recombinant TcG1- (93.6%, TcG2- (96%, TcG4- (94.6% and TcG(mix- (98% based ELISA exhibited significantly higher specificity compared to that noted for T. cruzi trypomastigote-based ELISA (77.8% in diagnosing T. cruzi-infection and avoiding cross-reactivity to Leishmania spp. No significant correlation was noted in the sera levels of antibody response and clinical severity of Chagas disease in seropositive subjects.Three candidate antigens were recognized by antibody response in chagasic patients from two distinct study sites and expressed in diverse strains of the circulating parasites. A multiplex ELISA detecting antibody response to three antigens was highly sensitive and specific in diagnosing T. cruzi infection in humans, suggesting that a diagnostic kit based on TcG1, TcG2 and TcG4 recombinant proteins will be useful in diverse situations.

  10. Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients

    Science.gov (United States)

    Castro-Sesquen, Yagahira E.; Gilman, Robert H.; Mejia, Carolina; Clark, Daniel E.; Choi, Jeong; Reimer-McAtee, Melissa J.; Castro, Rosario; Valencia-Ayala, Edward; Flores, Jorge; Bowman, Natalie; Castillo-Neyra, Ricardo; Torrico, Faustino; Liotta, Lance; Bern, Caryn; Luchini, Alessandra

    2016-01-01

    Background Early diagnosis of reactivated Chagas disease in HIV patients could be lifesaving. In Latin America, the diagnosis is made by microscopical detection of the T. cruzi parasite in the blood; a diagnostic test that lacks sensitivity. This study evaluates if levels of T. cruzi antigens in urine, determined by Chunap (Chagas urine nanoparticle test), are correlated with parasitemia levels in T. cruzi/HIV co-infected patients. Methodology/Principal Findings T. cruzi antigens in urine of HIV patients (N = 55: 31 T. cruzi infected and 24 T. cruzi serology negative) were concentrated using hydrogel particles and quantified by Western Blot and a calibration curve. Reactivation of Chagas disease was defined by the observation of parasites in blood by microscopy. Parasitemia levels in patients with serology positive for Chagas disease were classified as follows: High parasitemia or reactivation of Chagas disease (detectable parasitemia by microscopy), moderate parasitemia (undetectable by microscopy but detectable by qPCR), and negative parasitemia (undetectable by microscopy and qPCR). The percentage of positive results detected by Chunap was: 100% (7/7) in cases of reactivation, 91.7% (11/12) in cases of moderate parasitemia, and 41.7% (5/12) in cases of negative parasitemia. Chunap specificity was found to be 91.7%. Linear regression analysis demonstrated a direct relationship between parasitemia levels and urine T. cruzi antigen concentrations (p 105 pg was chosen to determine patients with reactivation of Chagas disease (7/7). Antigenuria levels were 36.08 times (95% CI: 7.28 to 64.88) higher in patients with CD4+ lymphocyte counts below 200/mL (p = 0.016). No significant differences were found in HIV loads and CD8+ lymphocyte counts. Conclusion Chunap shows potential for early detection of Chagas reactivation. With appropriate adaptation, this diagnostic test can be used to monitor Chagas disease status in T. cruzi/HIV co-infected patients. PMID:26919324

  11. Abbot Close Nursing Home, St. Marys Terrace, Askeaton, Limerick.

    LENUS (Irish Health Repository)

    Brown, Aisling F

    2015-01-01

    Mechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we demonstrated that prior exposure to S. aureus enhanced IFNγ responses upon subsequent infection, while adoptive transfer of S. aureus antigen-specific Th1 cells was protective in naïve mice. Translating these findings, we found that S. aureus antigen-specific Th1 cells were also significantly expanded during human S. aureus bloodstream infection (BSI). These Th1 cells were CD45RO+, indicative of a memory phenotype. Thus, exposure to S. aureus induces memory Th1 cells in mice and humans, identifying Th1 cells as potential S. aureus vaccine targets. Consequently, we developed a model vaccine comprising staphylococcal clumping factor A, which we demonstrate to be an effective human T cell antigen, combined with the Th1-driving adjuvant CpG. This novel Th1-inducing vaccine conferred significant protection during S. aureus infection in mice. This study notably advances our understanding of S. aureus cellular immunity, and demonstrates for the first time that a correlate of S. aureus protective immunity identified in mice may be relevant in humans.

  12. Quality assurance of the serologic diagnosis of Chagas' disease Garantía de calidad en el diagnóstico serológico de la enfermedad de Chagas

    Directory of Open Access Journals (Sweden)

    Estela N. Cura

    1998-04-01

    Full Text Available A quality assurance program of the Chagas' disease laboratory network of Argentina has been conducted by the National Reference Center since 1988, with the aim of assessing the reliability of serologic test results. Chagas' disease is endemic in Argentina, but the prevalence of seropositivity for Trypanosoma cruzi among 18- to 20-year-old men decreased from 5.8% in 1981 to 1.8% in 1994. About 600 laboratories form the Chagas' disease laboratory network, with main central laboratories in each of the 24 provinces in Argentina. The quality assurance program promotes regular use of good laboratory practice and internal and external quality control to improve performance of the participants; it also provides technical assistance and guidelines. Eventual corrective measures are discussed in workshops. Results of the first external evaluation by proficiency testing of serum panels and confirmation of results for 58 of the main laboratories reveal that from 1988 to 1994 the rate of agreement has increased.El Centro Nacional de Referencia ha llevado a cabo desde 1988 un programa de garantía de calidad en la red de laboratorios para el diagnóstico de la enfermedad de Chagas en Argentina. El propósito ha sido evaluar la confiabilidad de los resultados de la prueba serológica. La enfermedad de Chagas es endémica en Argentina, pero la prevalencia de seropositividad a Trypanosoma cruzi en hombres de 18 a 24 años bajó de 5,8% en 1981 a 1,8%