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  1. Genotipificación del gen HLA DQB1 en diabetes autoinmune del adulto (lada HLA DQB1 genotyping in latent autoimmune diabetes of adults (LADA

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    Mariela Caputo

    2005-06-01

    Full Text Available La diabetes autoinmune es una enfermedad multifactorial causada por factores genéticos predisponentes y ambientales desencadenantes. Se manifiesta en la edad infantojuvenil (diabetes tipo 1, DMID y en la edad adulta (diabetes autoinmune latente del adulto, LADA. La predisposición genética es de tipo poligénico, se ha establecido asociación con alelos polimórficos del gen DQB del sistema HLA, VNTR del gen de insulina y polimorfismos en el gen CTLA4. En el presente trabajo se analizaron las frecuencias de los alelos polimórficos del gen HLA DQB1 en 63 pacientes LADA, 70 pacientes DMID y 79 individuos normales. La tipificación de los alelos del gen DQB1 se llevó a cabo mediante el Kit SSP TM DQ Olerup. Se observó una mayor frecuencia del genotipo *0201-*0302 y *0201-*0201 en ambas poblaciones diabéticas con respecto a normales (pAutoimmune diabetes is a complex, multifactorial disease caused by the interaction of genetic and environmental factors. This autoimmune diabetes is commonly manifested in childhood and adolescence with a fast onset (type 1 diabetes, IDDM and it can occur in adult patients with a slow onset with delayed insulin requirement, (latent autoimmune diabetes in adults, LADA . Autoimmune diabetes has strong class II HLA association mainly with DQB gene which constitutes the first susceptibility locus. However, association with the 5’INS- VNTR and CTLA-4 genes has been established. In this study, we analysed the polimorphic allele frequencies of DQB HLA gene in 63 LADA patients, 70 IDDM and 79 control subjects. The HLA DQB1 alleles typing was detected through Olerup SSP TM DQ kit using sequence specific primers. We observed a positive association of *0201-*0302 and *0201-*0201 genotypes in both types of diabetic patients compared to the control group (p<0.05. Moreover, *0201-*0302 genotype was higher in IDDM than in LADA (p<0.05. On the other hand, the *0602 protective allele analysis showed a high prevalence in the

  2. Enfermedad autoinmune del oído interno

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    Alarcón G,Ricardo

    2006-01-01

    Se presenta un breve análisis de la enfermedad autoinmune del oído interno, descrita por primera vez por Me Cabe. El análisis comprende los aspectos fisiopatológicos, de diagnóstico y tratamiento de esta entidad clínica. Cada aspecto tratado tiene una justificación breve pero precisa de la Información bibliográfica existente al momento

  3. Enfermedades autoinmunes

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    Cañas Dávila, Carlos Alberto; Gabriel J. Tobón

    2008-01-01

    Tomado de: http://www.valledellili.org/sitio/images/stories/pdf/CSAgosto_2008.pdf ¿Qué es el sistema inmunológico?/¿Qué es la autoinmundad?/ ¿Qué tan frecuentes son las enfermedades autoinmunes?/¿Cuáles son las enfermedades autoinmunes?/¿Cómo se tratan las enfermedades autoinmunes?/Enfermedades autoinmunes más comunes.

  4. Hepatitis autoinmune.

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    LOJA OROPEZA, David; VILCA VASQUEZ, Maricela; AVILES GONZAGA, Roberto

    2013-01-01

    Three patients with autoinmune hepatitis type 1 diagnosed at the Hospital Nacional Arzobispo Loayza in Lima-Perú, between 1993 and 1995, are here reported, emphasis is made on the clinical, histological and therapeutical aspects.

  5. Impacto de las enfermedades autoinmunes en el manejo y pronóstico del síndrome coronario agudo

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    Lozano Rivas, Nuria L

    2016-01-01

    ntroducción: Los pacientes con enfermedades autoinmunes (EAI) presentan una carga importante de afectación cardiovascular que conducen tanto a una morbilidad como a una mortalidad prematura. Pero no queda claro si ello se debe a una mayor prevalencia de enfermedad cardiovascular establecida, a una mayor letalidad en la presentación de los casos o bien a un manejo diferente durante el episodio índice. Objetivos: El objetivo primario del estudio fue determinar las implicaciones pronósticas d...

  6. Ecos del deseo en el cuerpo, el enigma de la autoinmunidad // Desire echoes in the body autoinmunity enigma

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    Juliana María Bueno Restrepo

    2012-12-01

    Full Text Available El presente artículo es el resultado de la investigación Afección autoinmune y goce, llevada a cabo en el marco de la Maestría en Investigación psicoanalítica de la Universidad de Antioquia (Colombia. El propósito del mismo es desarrollar uno de los hallazgos de la investigación, según el cual habría una posible articulación entre los enigmas que plantean las afecciones autoinmunes y los avatares del deseo, los cuales tendrían un eco en el cuerpo. Lo anterior, partiendo de la concepción psicoanalítica del cuerpo como territorio de lo psíquico, como lugar de inscripción de las huellas que se producen en la relación al Otro, en la que se juega lo concerniente al goce y al deseo. // This article is the result of Autoimmune Condition and Jouissance research, carried out as part of the Master in Psychoanalytic Research of the University of Antioquia, Colombia. The purpose is to develop one of the research findings, acnigmas posed by autoimmune conditions and the vicissitudes of desire which would have an echo in the body. This is based on the psychoanalytic idea of the body as a psychic territory, place of the inscription of the traces that occur in the relation to the Other, involving jouissance and desire.

  7. Estudio de los resultados del tratamiento con fármacos inmunomoduladores biológicos en la enfermedad autoinmune ocular

    OpenAIRE

    2014-01-01

    Establecer la e\\icacia y seguridad de los fármacos biológicos etenercept, in\\liximab, adalimumab y rituximab en la enfermedad autoinmune ocular en la Unidad de Inmunología Ocular del Hospital Clínico Universitario de Valladolid (HCUV) Diseño: Estudio retrospectivo de investigación clínica observacional. Material y método: Treinta y tres pacientes con enfermedad autoinmune ocular tratados con in\\liximab, adalimumab, etanercept y rituximab fueron identi\\icados de la Unidad de I...

  8. Estudio clínico de la hepatitis autoinmune del adulto en Valencia A clinical study of adult autoimmune hepatitis in Valencia, Spain

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    M. L. García-Torres

    2008-07-01

    Full Text Available Introducción: existen factores geográficos que influyen en las características de la hepatitis autoinmune (HAI. Objetivo: conocer las características epidemiológicas, clínicas y respuesta al tratamiento de la hepatitis autoinmune en la provincia de Valencia. Material y métodos: se trata de un estudio realizado en ocho hospitales de Valencia, recogiendo de forma prospectiva los casos de hepatitis autoinmune diagnosticados en el año 2003 y de forma retrospectiva los diagnosticados entre 1994 y 2002. Resultados: se incluyeron 81 pacientes con HAI, siendo el 94% mujeres. La forma de presentación fue: 43% asintomático, 27% hepatitis aguda y 30% enfermedad hepática crónica. La mayoría (90% fueron del tipo 1, mientras que las de tipo 2 fueron más jóvenes (p = 0,007 y con predominio de hepatitis aguda (p = 0,04. Existía otra enfermedad autoinmune en uno de cada 4 casos. Al momento del diagnóstico una tercera parte de los pacientes presentaba cirrosis. La cirrosis se presentó sobre todo en pacientes de más de 60 años (p Objective: the clinical phenotype of autoimmune hepatitis (AIH varies among geographical areas. The aim of this study is to determine the salient features of AIH in adult patients from the province of Valencia, Spain. Material and methods: eighty-one patients with AIH attended to in eight acute-care hospitals between 1994 and 2003. New patients diagnosed with AIH during year 2003 were evaluated prospectively. Data from patients currently attending follow-up visits and diagnosed before 2003 were collected retrospectively. Results: a total of 94% of patients were females. Forty-three percent were asymptomatic, 27% had acute hepatitis, and 30% had chronic hepatitis. Type 1 AIH was diagnosed in 90% of cases. Type 2 AIH was more frequent in younger patients, and presented with an acute pattern. One third of patients had cirrhosis at onset. Patients with cirrhosis were older than 60 years more frequently. Immunosuppressants

  9. La crisis latente del Darwinismo

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    Abdalla, Maurício

    2006-06-01

    Full Text Available In this article I will be analyzing the Darwinist paradigm in the biological science, discussing its capacity to give satisfactory understanding of the new data from biochemistry, microbiology and genetics. The general aim of this analysis is to contribute for the debate about the statute of the scientific theories. Its specific aim is to reflect upon a possible crisis of the Darwinist paradigm, which could corroborate the conception of scientific theories as something historically transitory, and not as definitive discoveries.

    El presente artículo analiza el paradigma darwinista en las ciencias biológicas a partir de la pregunta sobre su capacidad de explicar satisfactoriamente los nuevos datos obtenidos de la bioquímica, la microbiología y la genética. El objetivo general del análisis es contribuir con una discusión acerca del estado de las teorías científicas y el objetivo específico es reflexionar sobre una posible crisis del paradigma darwinista, lo que corroboraría la concepción de las teorías científicas como algo históricamente transitorio y no como descubrimientos definitivos.

  10. Tiroiditis no-autoinmunes

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    Leonardo F. L Rizzo

    2014-12-01

    Full Text Available El término tiroiditis comprende un grupo de enfermedades de la glándula tiroides caracterizado por la presencia de inflamación, abarcando entidades autoinmunes y no-autoinmunes. Pueden manifestarse como enfermedades agudas con dolor tiroideo severo (tiroiditis subaguda y tiroiditis infecciosas, y condiciones en las cuales la inflamación no es clínicamente evidente, cursando sin dolor y presentando disfunción tiroidea y/o bocio (tiroiditis inducida por fármacos y tiroiditis de Riedel. El objetivo de esta revisión es aportar un enfoque actualizado sobre las tiroiditis no-autoinmunes cubriendo sus aspectos clínicos, diagnósticos y terapéuticos.

  11. Tiroiditis no-autoinmunes

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    Leonardo F. L. Rizzo; Daniela L Mana; Bruno, Oscar D.

    2014-01-01

    El término tiroiditis comprende un grupo de enfermedades de la glándula tiroides caracterizado por la presencia de inflamación, abarcando entidades autoinmunes y no-autoinmunes. Pueden manifestarse como enfermedades agudas con dolor tiroideo severo (tiroiditis subaguda y tiroiditis infecciosas), y condiciones en las cuales la inflamación no es clínicamente evidente, cursando sin dolor y presentando disfunción tiroidea y/o bocio (tiroiditis inducida por fármacos y tiroiditis de Riedel). El obj...

  12. Desarrollos metodológicos para el análisis de polimorfismos de los genes del sistema HLA y otros genes, no HLA, predisponentes a enfermedades autoinmunes

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    Ruiz Ortiz de Arrizabaleta, Estíbaliz

    2013-01-01

    Las enfermedades autoinmunes son enfermedades multifactoriales donde la genética, el sistema inmune y factores ambientales se encuentran relacionados. En muchas de ellas el Sistema Principal de Histocompatibilidad o HLA juega un papel importante. El HLA es un sistema molecular constituido por un conjunto de proteínas de membrana que son extraordinariamente polimórficas y que, debido a que se encuentran en una misma localización cromosómica con alto desequilibrio de ligamiento, se heredan en h...

  13. Agentes infecciosos y enfermedades autoinmunes

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    Carlos Riebeling; Vicente Madrid; Beatriz Elena Camarena; Oscar Peralta; Raúl Barrera

    1992-01-01

    En este trabajo se describen los aspectos molecidares de la relación entre agentes infecciosos y enfermedades autoinrnitnes; los mecanismos de respuesta inmune a los agentes infecciosos, y las Iiiyótesis más recientes de la causa de las enfermedades autoinmunes. Los antígenos son procesados y seleccionados por su inmitnogenicidad, ypresentadospor lasmolécitlasde HLA a los receptores de antígeno de los linfocitos T. Aunque existen rnuclias hipótesk sobre el origen de las enfermedades arrtoinmu...

  14. Anticuerpos anti 21 hidroxilasa séricos en pacientes con anticuerpos antifracción microsomal: Síndrome poliendocrino autoinmune Seric 21- hydroxilase antibodies in patients with anti-microsomal fraction antibodies: Autoimmune polyendocrine syndrome

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    Silvia Botta

    2007-04-01

    Full Text Available El síndrome poliendocrino autoinmune (SPA es la asociación de enfermedades endocrinas autoinmunes con otros desórdenes autoinmunes no endocrinos. Los tipos 1, 2 y 4 presentan adrenalitis autoinmune, esto indica la presencia de autoanticuerpos, y su marcador serológico específico es el anti 21 hidroxilasa (a21-OH. El SPA tipo 2 es la asociación de adrenalitis, enfermedad tiroidea y/o diabetes mellitus inducidas por autoanticuerpos. Como componentes menores, pueden estar asociados entre otros, vitiligo, alopecia y miastenia. Nuestros objetivos fueron: establecer la prevalencia de a21-OH séricos en pacientes con anticuerpos anti fracción microsomal (AFM positivos, enfermedad tiroidea autoinmune y/o afecciones endocrinas y no endocrinas autoinmunes; diagnosticar formas incompletas de SPA y estudiar individuos con probable riesgo de progresión a un SPA completo. Estudiamos 72 pacientes AFM positivos y 60 sujetos tomados como grupo control, AFM negativos. Hallamos a21-OH elevados en dos pacientes: A= 47 U/ml, hipotiroidismo autoinmune y miastenia; y B= 8.75 U/ml, hipotiroidismo autoinmune y vitiligo; ambos con ausencia de insuficiencia adrenal. La prevalencia de a21-OH encontrada fue del 2.8%. Las pacientes A y B corresponden a un SPA tipo 2 incompleto y latente en relación al componente adrenal. Considerando a los a21-OH marcadores de enfermedad autoinmune latente, el eventual riesgo de evolución hacia la afección clínica sugiere la necesidad de estrechos controles clínicos y bioquímicos periódicos.Autoimmune polyendocrine syndrome (APS is the association of autoimmune endocrine diseases, with other autoimmune nonendocrine disorders. APS types 1, 2 and 4 include autoimmune adrenalitis; this suggests the presence of autoantibodies. A specific serological marker for these is the anti 21- hydroxilase autoantibody (a21-OH. APS type 2 is the association of autoimmune adrenalitis, to autoimmune thyroid disease and/or diabetes mellitus, all

  15. Las enfermedades autoinmunes tienen un mismo origen

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    Universidad del Rosario, Programa de Divulgación Científica

    2010-01-01

    Las enfermedades autoinmunes (EAI) pueden ser consideradas como un enemigo interior, pues en éstas el sistema inmunológico ataca al propio organismo. Son complejas y multifactoriales, debido a que sus causas pueden ser medioambientales (tóxicos, virus, contaminantes, muchas veces desconocidas) y genéticas. El Centro de Estudio de Enfermedades Autoinmunes (CREA) estudia las EAI más comunes (artritis reumatoide, diabetes tipo 1, lupus eritematoso sistémico, tiroiditis autoi...

  16. Enfermedades Autoinmunes, tratamiento con Trichuris suis y otros helmintos

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    Iñigo Pallardo Fernández

    2015-01-01

    Objetivos: La "Hipótesis de la Higiene" postula sobre los efectos inmunomoduladores inducidos por agentes infecciosos en los seres humanos. El objetivo principal de este trabajo es indagar sobre las evidencias de esa hipótesis y sobre sus aplicaciones en el campo del tratamiento de las enfermedades autoinmunes, haciendo especial hincapié tanto en los mecanismos de acción en los que se basan estas aplicaciones como en los resultados reales obtenidos. Además analizará la posible evolución de es...

  17. Premisas de la tautología autoinmune en la esclerosis múltiple

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    Díaz Cortes, Diana Vanessa; Rodríguez Rodríguez, Alberto

    2012-01-01

    La esclerosis múltiple (EM) es una enfermedad desmielinizante del sistema nervioso central. Varias características de la EM son comunes a muchas enfermedades autoinmunes, como la mayor prevalencia en las mujeres (razón mujer:hombre 3:1), mecanismos fisiopatológicos comunes, heterogeneidad clínica, factores ambientales, herencia poligénica moderada, susceptibilidad génica, co-ocurrencia de diferentes enfermedades autoinmunes en un individuo y en los miembros de la familia, y respuesta a la ter...

  18. Enfermedades Autoinmunes, tratamiento con Trichuris suis y otros helmintos

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    Iñigo Pallardo Fernández

    2015-01-01

    Full Text Available Objetivos: La "Hipótesis de la Higiene" postula sobre los efectos inmunomoduladores inducidos por agentes infecciosos en los seres humanos. El objetivo principal de este trabajo es indagar sobre las evidencias de esa hipótesis y sobre sus aplicaciones en el campo del tratamiento de las enfermedades autoinmunes, haciendo especial hincapié tanto en los mecanismos de acción en los que se basan estas aplicaciones como en los resultados reales obtenidos. Además analizará la posible evolución de estas terapias, especialmente a la sombra de las controversias éticas que surgen de la aplicación de estos tratamientos en relación a si es lícito causar una infección para curar otra patología, como es el caso que nos ocupa. Resultados: Actualmente existen resultados prometedores de ensayos clínicos sobre terapias helmínticas aplicadas al tratamiento de enfermedades autoinmunes como son la enfermedad de Crohn y la colitis ulcerosa, resumidos en el apartado de resultados de este artículo. Igualmente prometedora es la gran variedad de ensayos clínicos que actualmente están en curso sobre la aplicación de la terapia helmíntica al tratamiento de diversas patologías en las que está involucrado el sistema inmunológico, como son: asma, rinitis alérgica, artritis reumatoide, esclerosis múltiple, diabetes Mellitus tipo I, encefalomielitis autoinmune, obesidad, autismo, etc que han llevado a identificar cuáles son los parásitos indicados en el tratamiento de este amplio espectro de enfermedades. Sin embargo es necesario indicar que no todos los helmintos son inmunorreguladores y, por lo tanto útiles en el tratamiento de estas enfermedades y que, los que lo son, no son útiles en el tratamiento de todas las enfermedades de origen inmunológico sino que presentan una marcada especificidad. Es más, la utilidad de éstos presenta una variabilidad importante, no sólo dependiente de la enfermedad de origen inmunológico a tratar, sino tambi

  19. Aplicación del modelo diagnóstico del grupo internacional para la hepatitis autoinmune (GHAI en una población de pacientes de Medellín

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    Gonzálo Correa Arango

    2001-04-01

    Full Text Available En nuestro medio no se conocen estudios donde se aplique el
    sistema de puntaje propuesto por el GIHAI (1. Nuestro objetivo fue
    evaluar la aplicabilidad del modelo y describir las características de este grupo de pacientes.

  20. Thyroid autoantibodies in autoimmune diseases Anticuerpos antitiroideos en enfermedades autoinmunes

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    Regina M. Innocencio

    2004-06-01

    Full Text Available Abnormalities in the thyroid function and thyroid autoantibodies have been frequently described in patients with autoimmune diseases but seldom in antiphospholipid syndrome patients. In order to determine the prevalence of thyroid function and autoimmune abnormalities, we compared serum thyrotropin (TSH, serum free thyroxine (T4 levels, thyroid antithyroglobulin (TgAb and antithyroperoxidase (TPOAb levels of 25 patients with systemic sclerosis, 25 patients with rheumatoid arthritis and 13 patients with antiphospholipid syndrome to a control group of 113 healthy individuals. Evaluation included a thorough clinical examination with particular attention to thyroid disease and a serologic immune profile including rheumatoid factor, antinuclear and anticardiolipin antibody measurements. Subclinical hypothyroidism (4.2Ciertas anormalidades en la función tiroidea y anticuerpos antitiroideos han sido frecuentemente descriptos en pacientes con enfermedades autoinmunes, y más raramente en pacientes con el síndrome antifosfolipídico. Para determinar la prevalencía de anormalidades en la función tiroidea y de autoinmunidad, comparamos los niveles séricos de tirotropina (TSH tiroxina libre en suero (T4 anticuerpos antitiroglobulina (TgAb y antitiroperoxidasa (TPOAb en 25 pacientes con esclerosis sistémica, 25 pacientes con artritis reumatoidea y 13 pacientes con el síndrome antifosfolipídico con un grupo control de 113 individuos aparentemente sanos. La evaluación incluyó un completo examen clínico con particular atención para las enfermedades de la tiroides y una evaluación inmunológica incluyendo dosaje del factor reumatoideo, anticuerpos antinucleares y anticardiolipina. Hipotiroidismo subclínico (4.2

  1. Evaluación de la reserva ovárica mediante test de clomifeno, ultrasonido vaginal y determinación de hormona antimulleriana en pacientes con hipotiroidismo primario autoinmune

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    Morales Martínez, Felipe Arturo

    2013-01-01

    La enfermedad tiroidea autoinmune se ha asociado a baja reserva ovárica, la cual puede ser causada por muchos otros factores incluyendo iatrogénica, quimioterapia, genética, infecciosa, autoinmune e idiopática. Gerard en el 2000, describió las principales etiologías de el fallo ovárico prematuro, siendo la etiología idiopática y autoinmune las más frecuentes, seguido del Síndrome de Turner y quimioterapia entre otras. Ejemplos de autoinmunidad endocrina auto inmunitaria asociada al fallo ovár...

  2. Estudio de polimorfismos genéticos en tiroiditis autoinmune

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    Iglesias López, Rosa Ana

    2015-01-01

    [ES]Estudio epidemiológico caso-control para comprobar la hipótesis de que ciertos polimorfismos genéticos relacionados con las citosinas y con el proceso de autofagia pueden modificar el riesgo de presentar tiroiditis autoinmune. Se realiza el estudio sobre 200 pacientes con tiroiditis autoinmune reclutados en el Servicio de Endocrinología y Nutrición en el Complejo Asistencial Universitario de Salamanca, en los que se confirma la ausencia de diferencias en cuanto a características epidemiol...

  3. Pancreatitis autoinmune: a propósito de un caso

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    E. Valdivielso Cortázar

    2016-01-01

    Full Text Available La pancreatitis autoinmune (PAI es una patología poco frecuente, aunque con una creciente incidencia en países orientales, si bien esto podría deberse a una mayor tasa de detección. Puede asociarse a otras patologías autoinmunes, y se ha descrito su asociación con la enfermedad sistémica por IgG4. La clínica es variada y el tratamiento habitualmente es médico, mediante corticoides. Se describe un caso clínico diagnosticado.

  4. El índice de anisidina como medida del deterioro latente de un material graso

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    Grompone, M. A.

    1991-02-01

    Full Text Available Although the peroxide value is a common measurement of lipid oxidation, its use is limited to the initial stages of oxidation. Since peroxides are vulnerable to further decomposition, the complete oxidative history of the oil may not be revealed. The anisidine test a measure of secondary oxidation products, is considered useful in that it shows the past history of the oil. Effects of accelerated storage test on the anisidine and peroxide values of commercially samples were studied. The results obtained indicate that the anisidine value is a good method to predict storage stability of fats. Some processing steps in producing edible fats and oils were studied. Bleaching clay performs decomposition of oxidation products and this effect alone would reduce the peroxide value. Comparative studies were undertaken to determine the effects of bleaching on the anisidine value. Analysis of damaged oils before and after deodorization showed that little reduction of anisidine value occurred.

    El índice de anisidina como medida del deterioro latente de un material graso. A pesar de que el índice de peróxido es una medida corriente de la oxidación de los lípidos, su uso está limitado a las etapas iniciales de dicha reacción. Como los peróxidos pueden sufrir descomposiciones posteriores, la historia oxidativa completa del aceite no se conoce por ellos. Se considera que el índice de anisidina, una medida de los productos de la oxidación secundaria, es muy útil para evaluar el pasado del aceite. Se estudiaron los efectos del almacenamiento acelerado de muestras comerciales sobre los índices de anisidina y de peróxido. Los resultados obtenidos indican que el índice de anisidina es un buen método para predecir dicha estabilidad. Se estudiaron algunas etapas del procesamiento de las grasas y aceites comestibles. Las arcillas de blanqueo producen la descomposición de los productos de oxidación y este efecto sólo puede reducir el

  5. Hepatitis autoinmune precedida por infección aguda por citomegalovirus en una mujer inmunocompetente

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    María Vares González

    2012-05-01

    Full Text Available El diagnóstico diferencial de las hepatitis es amplio y complejo, y con mucha frecuencia corresponde al médico internista filiar la etiología de la misma. De etiopatogenia no claramente establecida, lo que caracteriza a la hepatitis autoinmune (HAI es la pérdida de tolerancia inmune frente a los antígenos de los hepatocitos, conduciendo a la destrucción del parénquima hepático por linfocitos T autorreactivos. El papel de ciertos virus como factores favorecedores de la disregulación autoinmune ha sido propuesto previamente, en base a lo demostrado por los estudios de investigación y a la evidencia clínica. A continuación se expone un caso de HAI precedido por una infección aguda por CMV, lo que otorga al caso un interés particular, pues su incidencia es excepcional, existiendo sólo tres casos recogidos en la literatura (dos de ellos en pacientes sanos de 17 años, y otro en un varón inmunodeprimido trasplantado de médula ósea.

  6. Factores latentes del desarrollo en los municipios de la Región de Murcia.

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    José Alberto Hermoso Gutiérrez

    2004-01-01

    Full Text Available Un concepto de gran importancia dentro de la Economía lo constituye el desarrollo de una población, y en particular, el desarrollo económico-comercial de poblaciones. En nuestro caso, nos centraremos en los municipios de la Comunidad Autónoma de la Región de Murcia, con el fin de analizar las analogías y diferencias existentes entre ellos. En este trabajo, determinaremos factores latentes del desarrollo de los municipios de la Región de Murcia, a través de un conjunto de variables de carácter económico-comercial observadas sobre dichas poblaciones. Asimismo, analizaremos si existen diferencias de tipo económico-comercial, entre grupos homogéneos para el desarrollo, de municipios de la Comunidad Autónoma de la Región de Murcia y obtendremos una representación gráfica del posicionamiento relativo de éstos, aplicando el Análisis Canónico de Poblaciones.

  7. Dermamiositis autoinmune: caso clínico

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    Newton, María Belén; Ferrín, G; Frontini, N.; Ramírez, M.; Caíno, Hector; Lupi, Gabriel Horacio

    2016-01-01

    Interés del caso clínico: presentación de una entidad emergente y rara con una forma atípica de presentación. Actualización miopatía necrotizante autoinmunitaria (NAM): es una entidad emergente dentro del espectro de las miopatías inflamatorias. Se caracteriza por presentar pocos infiltrados inflamatorios (macrófagos mas que CD8) o ausentes Existe notable degeneración y necrosis de miocitos, con células musculares de regeneración, la isquemia muscular contribuye en el daño. Se caracterizan...

  8. Parasitosis intestinal extrema en la infancia previa al desarrollo de enfermedades reumáticas inflamatorias/autoinmunes

    OpenAIRE

    F. Javier Jiménez-Balderas; Adolfo Camargo-Coronel; Talavera, Juan O; José Gutiérrez; Abraham Zonana-Nacach; Ernesto A. Jiménez-Balderas

    2008-01-01

    Objetivo. Investigar la asociación del antecedente de parasitosis intestinal extrema (PIE) durante la infancia enpacientes ahora adultos con enfermedades reumáticas/ autoinmunes (ERAI). Métodos. Se estudiaron 54 pacientes consecutivos con ERAI, (27 con espondilitis anquilosante 9 con artritis reumatoide, 19 con lupus eritematoso sistémico) y 54 controles sanos; 27 hombres y 27 mujeres. Todos los sujetos tenían padres que informaran de eventos PIE durante la infancia, previos al inicio de la E...

  9. Humedad de equilibrio y calor latente de vaporización del ajonjolí. Sésamun indicum L.

    Directory of Open Access Journals (Sweden)

    Julio E. Ospina M.

    2011-06-01

    Full Text Available El ajonjolí (Sésamun indicum L., es una oleaginosa originaria de África y cultivada en las regiones tropicales y subtropicales de Asia y América. A los 110 días de sembrada se cosecha la semilla la cual se utiliza como materia prima especialmente en la industria de grasas y aceites comestibles. Actualmente se pierden en Colombia, un alto porcentaje de semillas durante el proceso de secado natura en el campo. Debido a la falta de información técnica, científica en secado y almacenamiento del grana de ajonjolí se procedió a estudiar la metodología para determinar, el contenido de humedad por el método de la estufa, las curvas y modelo para cuantificar la humedad de equilibrio y el calor latente de vaporización.

  10. Anemia hemolítica autoinmune postinfección por virus de la hepatitis A. Informe de caso; Autoimmune haemolytic anaemia associated to hepatitis A. Case report

    OpenAIRE

    Claudia Lucía Sossa Melo, MD; Sara Inés Jiménez Sanguino, MD; Carlos Andrés Pérez Martínez, MD; Amaury Alexis Amaris Vergara, MD; Luis Antonio Salazar Montaña, MD; Ángela Peña Castellanos, MD; Jesica Liliana Pinto Ramírez; Laura Andrea Rincón Arenas

    2010-01-01

    La anemia hemolítica autoinmune se asocia con una variedad de virus hepatotrópicos, en particular citomegalovirus (CMV), virus del Epstein-Barr y de la hepatitis B. No es frecuente dentro de la historia natural de la hepatitis A, la aparición de anemia hemolítica, y cuando se presenta, generalmente se asocia a deficiencia de glucosa-6-fosfato deshidrogenasa. Presentamos el caso de un paciente de sexo masculino sin hemólisis previa, con astenia e ictericia de dos meses de evolución y hepatomeg...

  11. Anemia hemolítica autoinmune mediada por IgG e IgA en un paciente con colitis ulcerativa

    OpenAIRE

    Rivera Barquero, Ángelo; Cano López, Francis

    2015-01-01

    La colitis ulcerativa crónica indeterminada (CUCI) se caracteriza por una inflamación que afecta en su inicio principalmente al recto, pudiendo extenderse en forma continua y difusa hacia el colon. La anemia es muy frecuente en pacientes con CUCI debido a sangrados y a la cronicidad de la enfermedad. Además, la CUCI puede disminuir la tolerancia inmunológica, lo que puede desencadenar en algunos casos la anemia hemolítica autoinmune (AHAI) mediada normalmente por anticuerpos del tipo IgG. La ...

  12. Pancreatitis autoinmune asociada a fibrosis retroperitoneal: evolución tras dos años de seguimiento Autoimmune pancreatitis associated with retroperitoneal fibrosis: outcome after 24 months of follow-up

    Directory of Open Access Journals (Sweden)

    M. Romero

    2008-10-01

    Full Text Available Introducción: la pancreatitis autoinmune es un tipo de pancreatitis crónica caracterizado por un infiltrado linfoplasmocitario y una elevación de IgG e IgG4, que se ha descrito asociada a diversas manifestaciones extrapancreáticas y enfermedades autoinmunes, lo cual apoya la teoría de un mecanismo autoinmune fisiopatólogico de base. Caso clínico: presentamos el caso de un varón que debutó simultáneamente con una pancreatitis autoinmune asociada a fibrosis retroperitoneal y lesión de la vía biliar extrapancreática, con respuesta total tras tratamiento con corticoides durante 4 meses y ausencia de recurrencia tras 24 meses de seguimiento. Discusión: la pancreatitis autoinmune es un tipo de pancreatitis crónica que probablemente forme parte de un proceso sistémico autoinmune, cuyas manifestaciones extrapancreáticas más frecuentes son la fibrosis retroperitoneal y las lesiones de la vía biliar extrapancreática. Su correcto diagnóstico e inicio precoz del tratamiento puede favorecer la resolución completa de las lesiones, principalmente en los casos de bajo grado de actividad, con menor probabilidad de recurrencia.Introduction: autoimmune pancreatitis is a kind of chronic pancreatitis characterized by the presence of lymphoplasmacytic infiltration and severely elevated serum IgG and IgG4, which has been associated to many extrapancreatic lesions and other autoimmune disorders, leading to the theory of an autoimmune mechanism involved in the pathogenesis of this disease. Case report: we report the case of a man who simultaneously presented with autoimmune pancreatitis associated with retroperitonal fibrosis, and a lesion of the extrapancreatic bile duct, with total response to corticosteroid treatment for 4 moths and absence of recurrence after 24 months of follow-up. Discussion: autoimmune pancreatitis is a kind of chronic pancreatitis that is probably a part of a systemic autoinmune disease, with retroperitoneal fibrosis and

  13. Influencia de los marcadores inmunológicos en la presentación clínica y en la evolución de pacientes con enfermedades autoinmunes sistémicas caracterizadas por la hiperactividad de los linfocitos B

    OpenAIRE

    Retamozo, María Soledad

    2014-01-01

    [spa] Las enfermedades autoinmunes sistémicas (EAS) poseen dos características esenciales. En su origen, todas comparten una alteración del sistema inmunológico que ocasiona lesión en los tejidos y células propios (enfermedad autoinmune). La segunda característica es que prácticamente no existe órgano o tejido que no pueda verse afectado por las EAS, siendo habitual que dichas afectaciones sean múltiples y simultáneas (enfermedad sistémica). El conjunto de trabajos presentados en esta Tesis D...

  14. Nuevo protocolo diagnóstico y terapéutico en la distocia de fase latente del trabajo de parto

    OpenAIRE

    Nápoles Méndez, Danilo

    2009-01-01

    Se realizó una investigación cuyo objeto de estudio lo constituye la gestante en fase latente del trabajo de parto con el objetivo de establecer un nuevo protocolo diagnóstico y terapéutico en la distocia de dicha fase. Inicialmente se efectuó un estudio descriptivo de 2 335 embarazadas desde enero de 1995 hasta diciembre del 2000, en el Hospital Ginecoobstétrico “Mariana Grajales Coello” de Santiago de Cuba, demostrándose que 85,3 % pasaron a fase activa en ocho horas o menos y pasado este t...

  15. Manifestaciones clínicas y paraclínicas de la hepatitis autoinmune en 48 pacientes de la ciudad de Medellín, 1980-2004

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    Jorge Hernando Donado Gómez

    2005-02-01

    Full Text Available Objetivo: describir las características clínicas, bioquímicas, histológicas, sociodemográficas y de tratamiento de los pacientes con hepatitis autoinmune (HAI. Metodología: estudio descriptivo retrospectivo de una serie de casos con 48 pacientes de la ciudad de Medellín con diagnóstico de HAI según los criterios del Grupo Internacional de Hepatitis Autoinmune. Resultados: la edad promedio al momento del diagnóstico fue 34 años, 40 pacientes (83.3% eran mujeres. Los hallazgos clínicos más frecuentes fueron fatiga (89.6% e ictericia (81.3%. Las medianas de los hallazgos de laboratorio pretratamiento fueron: AST 626 U/L, ALT 547.5 U/L, bilirrubina total 5.64 mg/dL, bilirrubina directa 3.4 mg/dL. Las medianas de los valores de laboratorio postratamiento fueron: AST 40.5 U/L, ALT 44.4 U/L, bilirrubina total 1.1 mg/dL, bilirrubina directa 0.4 mg/dL (p <0.000. El valor promedio de las gamaglobulinas fue 2.2 g/dL; 81.3% de los pacientes tuvieron biopsia hepática y de ellos 97.4% ten ían hallazgos compatibles con HAI. Cuarenta pacientes tenían anticuerpos antinucleares positivos. Se hallaron enfermedades autoinmunes concurrentes en 19 pacientes, la más frecuente fue la tiroiditis. El tratamiento más frecuentemente administrado fue prednisona más azatioprina en 56.3% de los pacientes. Cuarenta y un pacientes (85.4% respondieron completamente y 12 (25% recayeron. Conclusiones: las características sociodemográficas de este grupo de pacientes no son comparables con las encontradas en otras series. Los hallazgos clínicos, histológicos y bioquímicos son similares a los reportados en la literatura, lo que no se observó con las enfermedades autoinmunes asociadas. La mayoría de los pacientes pertenecen al subtipo 1 de la enfermedad.

  16. Estudio de nuevas técnicas de imagen en la evaluación y seguimiento de la neumopatía intersticial en las enfermedades autoinmunes sistémicas

    OpenAIRE

    Pinal Fernández, Iago

    2014-01-01

    La tomografía computarizada de alta resolución (TCAR) es la prueba de referencia para la valoración de las alteraciones estructurales del parénquima pulmonar en la enfermedad pulmonar intersticial (EPI) de las enfermedades autoinmunes sistémicas, también denominadas enfermedades del tejido conectivo (ETC). Junto con las pruebas de función respiratoria (PFRs), esenciales para el estudio del funcionalismo pulmonar de estos pacientes, la TCAR es la herramienta más útil para el diagnóstico y segu...

  17. Diagnosis and treatment of autoimmune hepatitis Diagnóstico y tratamiento de la hepatitis autoinmune

    Directory of Open Access Journals (Sweden)

    Maycos Leandro Zapata Muñoz

    2006-01-01

    Full Text Available Autoimmune hepatitis is a chronic, progressive disease, more frequent in women than in men, and of unknown etiology. Histologically, it is characterized by mononuclear cell infiltration in the portal tract, and biochemically by elevation of transaminases, hypergammaglobulinemia, and the presence of liver specific autoantibodies. Response to immunosuppressive treatment is generally good and the resolution of inflammation, both biochemically and histologically, is achieved in 87% of patients in 3 years after immunosuppressive treatment is started. Several studies have shown that in the absence of treatment the disease progresses rapidly to fibrosis, and the mortality rate is higher than 80% in the 5 years following diagnosis in untreated patients. Nevertheless, even if the patient has liver fibrosis, treatment decreases the inflammatory response and the histological progression of fibrosis. Life expectancy of patients who respond to treatment exceeds 90% at 10 years, and is 80% at 20 years; however, 10-15% of patients do not have satisfactory response to medical treatment. Standard treatment and new therapeutic options are reviewed in this article. La hepatitis autoinmune (HAI es una enfermedad crónica, progresiva, más frecuente en mujeres y de etiología desconocida, caracterizada histológicamente por infiltrado de células mononucleares en el tracto portal y bioquímicamente por hipertransaminasemia e hipergamaglobulinemia y por la presencia de autoanticuerpos específicos para el hígado. La respuesta al tratamiento inmunosupresor es generalmente buena y la resolución tanto bioquímica como histológica de la inflamación se logra en el 87% de los pacientes en tres años después de haber iniciado dicho tratamiento. Diversos estudios han demostrado que, en ausencia de tratamiento, la enfermedad lleva rápidamente a fibrosis y la tasa de mortalidad es mayor del 80% a los cinco años del diagnóstico. Por el contrario, si el paciente ya

  18. Anemia hemolítica autoinmune postinfección por virus de la hepatitis A. Informe de caso; Autoimmune haemolytic anaemia associated to hepatitis A. Case report

    Directory of Open Access Journals (Sweden)

    Claudia Lucía Sossa Melo, MD

    2010-01-01

    Full Text Available La anemia hemolítica autoinmune se asocia con una variedad de virus hepatotrópicos, en particular citomegalovirus (CMV, virus del Epstein-Barr y de la hepatitis B. No es frecuente dentro de la historia natural de la hepatitis A, la aparición de anemia hemolítica, y cuando se presenta, generalmente se asocia a deficiencia de glucosa-6-fosfato deshidrogenasa. Presentamos el caso de un paciente de sexo masculino sin hemólisis previa, con astenia e ictericia de dos meses de evolución y hepatomegalia 14 cm por debajo del reborde costal derecho. Los hallazgos en los exámenes de laboratorios mostraron anemia hemolítica con Coombs directo positivo, anticuerpos tipo inmunoglobulina M contra el virus de la hepatitis A positivos, niveles de bilirrubinas 20 veces y aminotrasferasas cuatro veces por arriba del rango normal; con estos datos el paciente fue diagnosticado como hepatitis A complicada con anemia hemolítica y probable hepatitis autoinmune asociada, por lo que se inició manejo con corticoides, alcanzándose mejoría clínica. Resaltamos la importancia de descartar la infección por el virus de la hepatitis A como posible etiología de anemia hemolítica autoinmune.______________________________________________________________________ Acute auto inmune haemolytic anaemia is associated with a variety of hepatotropic viruses, in particular cytomegalovirus, Epstein Barr virus and hepatitis B. The typical course of hepatitis A is rarely complicated with glucose-6-phosphate dehydrogenase deficiency. Wepresent the case of a man without previous haemolysis, he had been unwell for two months with fatigue and jaundice, the liver edge was palpable and tender 14 cm below the costal margin. Clinical chemistry showed haemolytic anaemia with positive direct coombs test, immunoglobulin M antibodies to hepatitis A virus were detected, the total bilirrubin concentration 20 times the upper and transaminase 4 times upper limit for normal levels; with this

  19. Hepatitis autoinmune en la edad pediátrica Autoimmune hepatitis in pediatric patients

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    R. García Romero

    2007-05-01

    Full Text Available Introducción: la hepatitis autoinmune es una enfermedad inflamatoria de origen desconocido responsable de una destrucción progresiva del hígado y evolución hacia la cirrosis. Objetivo: el objetivo es evaluar las características de las hepatitis autoinmunes en la población infantil. Material y métodos: estudio retrospectivo de pacientes diagnosticados en nuestro servicio en los últimos 10 años. Las variables analizadas son: edad, sexo, forma de presentación, función hepática, inmunoglobulinas, autoinmunidad, histología, tratamiento, necesidad de trasplante y evolución clínica. Según la positividad de los auto-anticuerpos se clasifican en tipo I (ANA y/o ASMA y tipo II (LKM-1. Resultados: se diagnostica a siete pacientes, 5 mujeres (71,5% y 2 varones (28,5%; tipo I 5 y tipo II dos pacientes. La edad al diagnóstico es 21 meses a 12 años. En el tipo I la presentación clínica es como hepatitis aguda en 3 casos y 2 pacientes con insuficiencia hepática progresiva. Las tipo II se diagnostican tras un hallazgo analítico siendo asintomáticas. La elevación de transaminasas (x10 su valor se observa en el 71,5% e hipergammaglobulinemia en el 85%. El tratamiento instaurado es azatioprina y corticosteroides con un tiempo medio de remisión de 14 meses. Dos pacientes recaen al retirar corticosteroides. Conclusión: las formas de presentación son variadas y puede ser indistinguible a una hepatitis viral. Se debe sospechar ante una elevación de las aminotransferasas y la presencia de hipergammaglobulinemia. Con buenos resultados el tratamiento recomendado sería azatioprina y corticosteroides. Existen altos porcentajes de recaídas al retirar la corticoterapia por lo que algunos pacientes precisarían de dosis mínimas para mantener la remisión.Background: autoimmune hepatitis (AIH is an inflammatory disease of unknown origin that is responsible for progressive liver necrosis and ultimately cirrhosis. Objective: our aim was to evaluate

  20. Características clínicas y sociodemográficas de pacientes colombianos con Síndrome de Sjögren solo y asociado a otras enfermedades autoinmunes

    OpenAIRE

    Amador-Patarroyo, Manuel-José

    2013-01-01

    Introducción: Dado que una de las principales comorbilidades asociadas al síndrome de Sjögren es la presencia de otra enfermedad autoinmune, el objetivo de este estudio fue investigar la frecuencia de poliautoinmunidad en pacientes con síndrome de Sjögren y evaluar sus factores asociados. Métodos: Este fue un estudio de corte transversal en el que 410 pacientes con síndrome de Sjögren (por criterios del Consenso Americano-Europeo, incluyendo biopsia positiva) fueron sistemáticamente inclu...

  1. TAXOMETRÍA DE CONGLOMERADOS DEL TRASTORNO POR DÉFICIT DE ATENCIÓN/HIPERACTIVIDAD CON ANÁLISIS DE CLASES LATENTES Y DE CORRESPONDENCIAS

    OpenAIRE

    Pineda, David A; Universidad de Antioquia, Colombia; Aguirre-Acevedo, Daniel Camilo; Universidad de Antioquia, Colombia; Lopera, Francisco; Universidad de Antioquia; Pineda, Daniel A; Universidad de Antioquia, Colombia; Arcos-Burgos, Mauricio; Universidad de Antioquia, Colombia

    2007-01-01

    Resumen en ingles y en espanolEl trastorno por déficit de atención/hiperactivad (TDA/H) presenta síntomas heterogéneos y con diversos grados de intensidad. El análisis de conglomerados de clases latentes (ACCL) puede clasificar a los niños a partir de los datos directos provenientes de cualquier instrumento que muestre estos síntomas, sin un diagnóstico de patrón de oro previo. Se utilizó un instrumento tipo lista de chequeo para los síntomas de TDA/H y otro para las comorbilidades del TDA/H....

  2. Microscopía confocal en las enfermedades ampollosas subepidérmicas autoinmunes

    OpenAIRE

    Campos Domínguez, Minia

    2016-01-01

    Las enfermedades ampollosas subepidérmicas autoinmunes constituyen un complejo grupo de trastornos cutáneos en cuya patogenia se rompe la unión dermoepidérmica. Su alta morbilidad se debe a la afectación de grandes áreas cutáneas por ampollas, erosiones o cicatrices y a la posible afectación de las mucosas oral, conjuntival, laríngea, esofágica y genitourinaria. Además, se ha demostrado su asociación con enfermedades neurológicas degenerativas y neoplasias. Existe un gran solapamiento clínico...

  3. Casos estandarizados en reumatología. Enfermedades autoinmunes sistémicas

    OpenAIRE

    Nolla Solé, Joan Miquel

    2014-01-01

    Introducción. Las enfermedades autoinmunes sistémicas, denominadas también colagenosis o conectivopatías, constituyen una heterogéneo grupo de procesos que presentan en común: los fenómenos de autoinmunidad, que tienen valor patogénico y, en muchas ocasiones, diagnóstico y que posibilitan la definición de subgrupos pronósticos y terapéuticos, así como la afección simultánea de diversos órganos y sistemas corporales, circunstancia que confiere a las entidades un gran polimorfismo clínico ...

  4. Detección del virus del enanismo amarillo de la cebolla (OYDV y el virus latente común del ajo (GCLV en ajo (Allium sativum L costarricense

    Directory of Open Access Journals (Sweden)

    Anny Vannesa Guillén Watson

    2011-05-01

    Full Text Available Las enfermedades virales son responsables de pérdidas importantes en el rendimiento del cultivo de ajo alrededor del mundo, ya que limitan su producción. En esta investigación se analizó material de ajo costarricense para determinar la incidencia de los virus: Garlic Common Latent Virus (GCLV y Onion Yellow Dwarf Virus (OYDV, mediante la técnica DAS-ELISA, con el fin de conocer el estado fitosanitario del material criollo. Se utilizaron bulbos de campo de apariencia normal (N, normales con túnica amarilla (TA y con deformaciones (D; y hojas de campo normales (N, sintomáticas (S y con presencia de posibles vectores  virales (VT. Se analizaron vitroplantas producto de la introducción de ápices de 1,0 y 0,5cm de longitud procedentes de dientes normales (N y con túnica amarilla (TA; así como dos lotes de bulbillos obtenidos in vitro de introducciones de ápices de 1,0cm de largo a partir de bulbos de apariencia normal. Se encontró que el 33% de los bulbos de campo analizados para GCLV fueron positivos (TA, mientras que OYDV se detectó en el 100%, sin importar la apariencia. El 100% de las hojas fue positivo para GCLV, y para OYDV soloaquellas de apariencia normal (33%. El 100% de las vitroplantas no presentaron infección de GCLV, mientras que para OYDV solo las introducidas de ápices de 1,0cm provenientes de bulbos con túnica amarillenta no mostraron incidencia. Se determinó GCLV en el 100% de lasmuestras para ambos lotes de bulbificación in Vitro, y OYDV solo en el 50%. Se concluye que los virus OYDV y GCLV están presentes en el ajo costarricense y se detectaron mediante la técnica DASELISA, con una alta incidencia en el material local y con infección diferencial según el órgano analizado. Se recomienda combinar diversas metodologías junto con el cultivo de ápices in vitro, para obtener mayor eficacia en la limpieza viral, lo que contribuiría a incrementar el valor y potenciar el cultivo de la semilla local.

  5. Acil coenzima-a sintetasas de cadena larga (acsls) como biomarcadores citoserológicos en enfermedades inflamatorias o autoinmunes

    OpenAIRE

    Matesanz, F.; Fedetz, María; Ndagire, D.; Alcina, Antonio; Sabio, José Mario

    2010-01-01

    [ES] Uso de las Acil-Coenzima-A sintetasas de cadena larga (ACSL) como biomarcadores cito-serológicos de enfennedades inflamatorias o autoinmunes, y especialmente de lupus eritematoso sistémico, y método de obtención de datos útiles para el diagnóstico y seguimiento de dichas enfennedades.

  6. Síndrome Poliglandular Autoinmune Tipo II: Posible Asociación con HLA DRB1*-DQB1* Possible association of Type II Autoimmune Polyendrocrine Syndrome with HLA DRB1*-DQB1*

    Directory of Open Access Journals (Sweden)

    M.S. Mallea Gil

    2010-12-01

    Full Text Available Los síndromes poliendocrinos autoinmunes (APS asocian enfermedades endocrinas autoinmunes con otros desórdenes autoinmunes no endocrinos. El APS tipo II se caracteriza por compromiso primario suprarrenal, tiroideo y/o DM tipo I. Presentamos un paciente masculino de 46 años que fue internado por astenia, adinamia, hiporexia, severa disminución de peso, mareos y vómitos. Antecedente de obesidad y diabetes diagnosticada 3 años antes. Presentaba hipotensión arterial, hiperpigmentación de mucosas y pliegues, anemia, hiponatremia e hipoglucemias frecuentes a pesar de la disminución de la dosis de insulina. Se diagnosticó insuficiencia suprarrenal, concomitantemente con hipotiroidismo y diabetes tipo 1, todas de origen autoinmune, iniciándose reemplazo hormonal. Se encontró una posible asociación del HLA DRB1*-DQB1* en los estudios genéticos. Conclusiones: Nuestro paciente presenta el HLA DQB1*0302 descripto en el APSII, pero el HLA DRB1 *08 encontrado no está descripto en este síndrome ni en ningún otro desorden autoinmune. En pacientes con Diabetes tipo 1 que disminuyan el requerimiento insulínico, habría que descartar insuficiencia suprarrenal, un componente del APS II, como factor etiológico, a pesar de su baja prevalencia.Autoimmune polyendocrine syndromes (APS are the association of autoimmune endocrine diseases with other non-endocrine autoimmune disorders. Type II APS is defined by occurrence of Addison´s disease with thyroid autoimmune disease and/or type 1 diabetes mellitus. We present a 46-year-old male patient who was hospitalized because of asthenia, adynamia, hyporexia, severe loss of weight, dizziness and vomiting. Diabetes mellitus had been diagnosed 3 years earlier when he was obese. He presented arterial hypotension, anemia, darkening of the skin and oral mucosa, hyponatremia and frequent hypoglycemia although his insulin dose was decreased. Adrenal insufficiency was diagnosed together with hypothyroidism and type

  7. Anemia hemolítica autoinmune en un niño con hepatitis de células gigantes

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    Jessica Gómez

    2012-12-01

    Full Text Available La asociación de anemia hemolítica autoinmune (AHAI con hepatitis de células gigantes (HCG es un trastorno raro en la infancia. Son pocos los casos reportados y la gran mayoría fallecen a pesar de transplante hepático. La AHAI usualmente precede el desarrollo de la afección hepática. El diagnóstico temprano de esta asociación y el inicio de terapia inmunosupresora previene la progresión de la enfermedad.

  8. Anemia hemolítica autoinmune en un niño con hepatitis de células gigantes

    OpenAIRE

    Jessica Gómez; Kathia Valverde

    2012-01-01

    La asociación de anemia hemolítica autoinmune (AHAI) con hepatitis de células gigantes (HCG) es un trastorno raro en la infancia. Son pocos los casos reportados y la gran mayoría fallecen a pesar de transplante hepático. La AHAI usualmente precede el desarrollo de la afección hepática. El diagnóstico temprano de esta asociación y el inicio de terapia inmunosupresora previene la progresión de la enfermedad.

  9. Acil Coenzima-A sintetasas de cadena larga (ACSLs) como biomarcadores cito-serológicos en enfermedades inflamatorias o autoinmunes

    OpenAIRE

    Matesanz, F.; Fedetz, María; Ndagire, D.; Alcina, Antonio; Sabio, José Mario

    2010-01-01

    Uso de las Acil-Coenzima-A sintetasas de cadena larga (ACSL) como biomarcadores cito-serológicos de enfermedades inflamatorias o autoinmunes, y especialmente de lupus eritematoso sistémico, y método de obtención de datos útiles para el diagnóstico y seguimiento de dichas enfermedades. Venta

  10. Latent Period of Relaxation.

    Science.gov (United States)

    Kobayashi, M; Irisawa, H

    1961-10-27

    The latent period of relaxation of molluscan myocardium due to anodal current is much longer than that of contraction. Although the rate and the grade of relaxation are intimately related to both the stimulus condition and the muscle tension, the latent period of relaxation remains constant, except when the temperature of the bathing fluid is changed.

  11. Latent myofascial trigger points.

    Science.gov (United States)

    Ge, Hong-You; Arendt-Nielsen, Lars

    2011-10-01

    A latent myofascial trigger point (MTP) is defined as a focus of hyperirritability in a muscle taut band that is clinically associated with local twitch response and tenderness and/or referred pain upon manual examination. Current evidence suggests that the temporal profile of the spontaneous electrical activity at an MTP is similar to focal muscle fiber contraction and/or muscle cramp potentials, which contribute significantly to the induction of local tenderness and pain and motor dysfunctions. This review highlights the potential mechanisms underlying the sensory-motor dysfunctions associated with latent MTPs and discusses the contribution of central sensitization associated with latent MTPs and the MTP network to the spatial propagation of pain and motor dysfunctions. Treating latent MTPs in patients with musculoskeletal pain may not only decrease pain sensitivity and improve motor functions, but also prevent latent MTPs from transforming into active MTPs, and hence, prevent the development of myofascial pain syndrome.

  12. Estudio de Genes Candidatos en la Susceptibilidad y Curso Clínico del Lupus Eritematoso Sistémico.

    OpenAIRE

    Aguilar Silva, Francisco José

    2016-01-01

    Las enfermedades autoinmunes sistémicas constituyen un grupo de patologías donde existen disfunciones del sistema inmunitario con manifestaciones clínicas floridas que se traducen en la afectación simultánea o sucesiva de la mayoría de los órganos y sistemas. El prototipo de este tipo de enfermedades es el lupus eritematoso sistémico (LES). La etiopatogenia de las enfermedades autoinmunes es compleja y en ella intervienen factores gen&...

  13. Frequency Of Pancreatic Beta-Cell Autoimmunity Markers In Patients With Autoimmune Thyroid Disease Frecuencia de marcadores de autoinmunidad beta pancreática en pacientes con enfermedad tiroidea autoinmune

    Directory of Open Access Journals (Sweden)

    María E. Primo

    2008-02-01

    Full Text Available A total of 305 ambulatory patients recruited at the Division of Endocrinology, Hospital de Clínicas, University of Buenos Aires, with autoimmune thyroid disease (AITD were studied to search for associations between autoimmune thyroid disease and presence of serum markers of autoimmune diabetes mellitus. Screening for markers of pancreatic beta-cell autoimmunity was performed by radioligand binding assays (RBA as follows: autoantibodies to glutamic acid decarboxylase (GADA and proinsulin (PAA were determined in all sera, whereas autoantibodies to protein tyrosine phosphatase (IA-2A and insulin (IAA were additionally measured in 200 sera randomly selected from the total collection. In addition, every GADA positive serum among the remaining 105 sera was systematically tested for the presence of IA-2A and IAA. In the cohort of 305 AITD patients 22 (7.2% were previously diagnosed as type 1, type 2 or insulin-requiring type 2 diabetics. Ten of these patients presented serum marker positivity specific for β-cell autoantigens and 12 were marker negative. On the other hand, considering the majority of non-diabetic AITD patients (n=283, β-cell marker positivity was detected in 17 individuals (6.0%. The prevalence of autoimmune diabetes markers was much higher in the studied population than in the general population utilized as a control group, and GADA was the most frequent marker.Se investigó la asociación entre enfermedad tiroidea autoinmune y la presencia de marcadores séricos de diabetes mellitus en 305 pacientes ambulatorios con enfermedad tiroidea autoinmune reclutados en la División Endocrinología. La búsqueda de marcadores de autoinmunidad contra las células beta pancreáticas se realizó por la técnica de unión de radioligandos (RBA como se detalla a continuación: se determinaron autoanticuerpos contra la decarboxilasa del ácido glutámico (GADA y proinsulina (PAA en todos los sueros, mientras que los anticuerpos contra la prote

  14. Latent fingerprint matching.

    Science.gov (United States)

    Jain, Anil K; Feng, Jianjiang

    2011-01-01

    Latent fingerprint identification is of critical importance to law enforcement agencies in identifying suspects: Latent fingerprints are inadvertent impressions left by fingers on surfaces of objects. While tremendous progress has been made in plain and rolled fingerprint matching, latent fingerprint matching continues to be a difficult problem. Poor quality of ridge impressions, small finger area, and large nonlinear distortion are the main difficulties in latent fingerprint matching compared to plain or rolled fingerprint matching. We propose a system for matching latent fingerprints found at crime scenes to rolled fingerprints enrolled in law enforcement databases. In addition to minutiae, we also use extended features, including singularity, ridge quality map, ridge flow map, ridge wavelength map, and skeleton. We tested our system by matching 258 latents in the NIST SD27 database against a background database of 29,257 rolled fingerprints obtained by combining the NIST SD4, SD14, and SD27 databases. The minutiae-based baseline rank-1 identification rate of 34.9 percent was improved to 74 percent when extended features were used. In order to evaluate the relative importance of each extended feature, these features were incrementally used in the order of their cost in marking by latent experts. The experimental results indicate that singularity, ridge quality map, and ridge flow map are the most effective features in improving the matching accuracy.

  15. Sífilis latente

    OpenAIRE

    Arévalo, Jose David

    2012-01-01

    Trabajo leído por su autor en la Academia Nacional de Medicina, el día 20 de mayo de 1948. La sífilis Latente es aquella en que el organismo se ha defendido biológicamente sin ningún tratamiento, En la sífilis latente hay que distinguir: la latencia clínica, la latencia serológica y la latencia patológica.

  16. Pancreatitis autoinmune: pseudotumor inflamatorio, afectación multifocal, hipertensión portal y evolución a largo plazo Autoimmune pancreatitis: inflammatory pseudotumor, multifocal fibrosclerosis, portal hypertension, and long-term outcome

    Directory of Open Access Journals (Sweden)

    J. L. Beristain

    2008-10-01

    Full Text Available La pancreatitis autoinmune es una enfermedad recientemente caracterizada y que en la actualidad constituye un reto diagnóstico especialmente su diferenciación con el cáncer de páncreas. Su evolución a largo plazo es poco conocida, presentándose un caso estudiado a lo largo de 14 años y mostrando su evolución clínica, bioquímica y morfológica. Paciente mujer de 54 años que debuta con un cuadro de ictericia obstructiva y molestias abdominales inespecíficas y constatación en la TAC de un aumento de la cabeza del páncreas, todo ello sugestivo de neoplasia de páncreas. Fue intervenida evidenciándose un aumento difuso de todo el páncreas descartándose malignidad intraoperatoriamente, realizando únicamente colecistectomía y coledocoduodenostomía, quedando diagnosticada entonces como pancreatitis crónica. Durante los años posteriores fueron apareciendo diferentes procesos autoinmunes como asma, sialoadenitis y colangitis esclerosante secundaria, así como episodios recurrentes de ictericia e insuficiencia pancreática endocrina y exocrina. La aparición de estas complicaciones y la detección de niveles séricos elevados de IgG4 y de anticuerpos antianhidrasa carbónica II condujo a la reevaluación de la histología inicial concluyendo finalmente con el diagnóstico de pancreatitis autoinmune al evidenciarse una infiltración linfocitaria y plasmacitaria IgG4+, así como fibrosis y flebitis obliterativa. En los últimos años se ha añadido a las anteriores complicaciones una fibrosis retroperitoneal con hipertensión portal, varices esofágicas y esplenomegalia.Autoimmune pancreatitis is a recently characterized disease that still constitutes a diagnostic challenge, especially regarding differential diagnosis from neoplasia. Long-term outcome is poorly known. We herein report a case of a patient with autoimmune pancreatitis and 14 years of follow-up, and show its clinical, biochemical, and morphological characteristics. A 54

  17. Autoimmune blistering diseases of the pemphigus group = Enfermedades ampollosas autoinmunes del grupo de los pénfigos

    Directory of Open Access Journals (Sweden)

    Juliana Calle Isaza

    2014-07-01

    Full Text Available Autoimmune blistering diseases of the pemphigus group Blisters may appear in many dermatological diseases, but they are not necessarily of autoimmune etiology. For the study of blistering diseases, it is necessary to take into account the clinical aspects, the history of when and how blisters appeared, the epidemiological and histological information (for instance, the skin level at which blisters are located, and whether inflammatory infiltrates are present. In order to corroborate the autoimmune etiology of blisters, it is important to have the results of confirmatory tests such as direct and indirect immunofluorescence, immune blotting, enzyme-linked immune-assay (ELISA, immune precipitation, and electronic microscopy. Information on autoantibodies serum titers may help to conduct a more precise immunosuppressive therapy.

  18. Latent tuberculosis infection.

    Science.gov (United States)

    Nuermberger, Eric; Bishai, William R; Grosset, Jacques H

    2004-06-01

    Latent tuberculosis infection (LTBI) is a clinical condition characterized by a positive tuberculin skin test in the absence of clinical or radiological signs of active tuberculosis disease. It has been estimated that one third of the world's population is latently infected with Mycobacterium tuberculosis and serves as an enormous reservoir for future cases of active tuberculosis. The detection and treatment of individuals with LTBI and a high risk of progression to active tuberculosis are effective means to control the spread of tuberculosis. Furthermore, a better understanding of the host-pathogen interactions that result in latent infection could provide important insights for future drug or vaccine development. This chapter reviews recent developments in the molecular genetics, natural history, diagnosis, and treatment of LTBI within its historical context, including the impact of human immunodeficiency virus infection. Current treatment recommendations are also summarized.

  19. Potentiation of latent inhibition.

    Science.gov (United States)

    Rodriguez, Gabriel; Hall, Geoffrey

    2008-07-01

    Rats were given exposure either to an odor (almond) or a compound of odor plus taste (almond plus saline), prior to training in which the odor served as the conditioned stimulus. It was found, for both appetitive and aversive procedures, that conditioning was retarded by preexposure (a latent inhibition effect), and the extent of the retardation was greater in rats preexposed to the compound (i.e., latent inhibition to the odor was potentiated by the presence of the taste). In contrast, the presence of the taste during conditioning itself overshadowed learning about the odor. We argue that the presence of the salient taste in compound with the odor enhances the rate of associative learning, producing a rapid loss in the associability of the odor. This loss of associability will generate both overshadowing and the potentiation of latent inhibition that is observed after preexposure to the compound.

  20. Latent classification models

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre

    2005-01-01

    One of the simplest, and yet most consistently well-performing setof classifiers is the \\NB models. These models rely on twoassumptions: $(i)$ All the attributes used to describe an instanceare conditionally independent given the class of that instance,and $(ii)$ all attributes follow a specific...... parametric family ofdistributions.  In this paper we propose a new set of models forclassification in continuous domains, termed latent classificationmodels. The latent classification model can roughly be seen ascombining the \\NB model with a mixture of factor analyzers,thereby relaxing the assumptions...... classification model, and wedemonstrate empirically that the accuracy of the proposed model issignificantly higher than the accuracy of other probabilisticclassifiers....

  1. Dynamic Latent Classification Model

    DEFF Research Database (Denmark)

    Zhong, Shengtong; Martínez, Ana M.; Nielsen, Thomas Dyhre

    as possible. Motivated by this problem setting, we propose a generative model for dynamic classification in continuous domains. At each time point the model can be seen as combining a naive Bayes model with a mixture of factor analyzers (FA). The latent variables of the FA are used to capture the dynamics...... in the process as well as modeling dependences between attributes....

  2. Esplenectomía en pacientes con enfermedades hematológicas autoinmunes. Estudio comparativo entre técnicas laparoscópica y abierta

    OpenAIRE

    Salvador Francisco Campos-Campos; José Luis Lara-Olmedo; Jorge Cervantes-Cruz; Juan Carlos Licona-Hernández; Germán Delgadillo-Teyer; Manuel Gonzalo Garcés-Monterrubio

    2007-01-01

    Objetivo: Evaluar la utilidad de la esplenectomía laparoscópica en el tratamiento de enfermedades hematológicas y comparar sus resultados con esplenectomía abierta. Material y métodos: Serie comparativa de 37 casos seleccionados en forma aleatoria: 21 pacientes consecutivos con esplenectomía laparoscópica versus 16 con esplenectomía abierta. Resultados: Seis pacientes tenían anemia hemolítica autoinmune, 29 púrpura trombocitopénica idiopática y dos síndrome de Evans. Aquellos con púrpura trom...

  3. Transfusiones en pacientes con pruebas de compatibilidad positivas y en aquellos con anemia hemolítica autoinmune Approach to transfusion support in patients with positive compatibility tests and in those with autoimmune hemolytic anemia

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available Es frecuente la presencia de pruebas de compatibilidad positivas en pacientes que requieren soporte transfusional. Los pacientes con anemia hemolítica autoinmune presentan autoanticuerpos calientes o fríos que reaccionan contra antígenos de los eritrocitos y producen reacciones hemolíticas, que pueden ir desde leves hasta graves. Los pacientes multitransfundidos o con insuficiencia renal crónica o con anemia de células falciformes, presentan aloanticuerpos que dificultan el tratamiento con derivados de la sangre. La frecuencia de los mismos es hasta de 32% en algunas series. Dado el perfeccionamiento de las técnicas de laboratorio, en la actualidad son posibles la detección y determinación de la especificidad de los autoanticuerpos y aloanticuerpos; el enfoque integral del paciente y el conocimiento de dichas técnicas son los mejores fundamentos para un soporte transfusional seguro. Positive compatibility tests in patients who need blood transfusions are common. Patients with autoimmune hemolytic anemia may have warm or cool autoantibodies that react with red blood cell antigens and produce hemolytic transfusion reactions. Multitransfused patients, and those with either chronic renal disease or sickle cell disease, have alloantibodies that make blood transfusion difficult. In some series the frequency of such antibodies is as high as 32%. Detection and determination of specificity of autoantibodies and alloantibodies are now possible because of technical developments in laboratory. An integral approach to patients and the knowledge of these procedures are the best bases to offer secure blood transfusions.

  4. Peach latent mosaic viroid: not so latent.

    Science.gov (United States)

    Flores, Ricardo; Delgado, Sonia; Rodio, María-Elena; Ambrós, Silvia; Hernández, Carmen; Serio, Francesco D I

    2006-07-01

    SUMMARY Taxonomy: Peach latent mosaic viroid (PLMVd) is the type species of the genus Pelamoviroid within the family Avsunviroidae of chloroplastic viroids with hammerhead ribozymes. Physical properties: A small circular RNA of 336-351 nt (differences in size result from the absence or presence of certain insertions) adopting a branched conformation stabilized by a pseudoknot between two kissing loops. This particular conformation is most likely responsible for the insolubility of PLMVd in highly saline conditions (in which other viroids adopting a rod-like conformation are soluble). Both polarity strands are able to form hammerhead structures and to self-cleave during replication as predicted by these ribozymes. Biological properties: Although most infections occur without conspicuous symptoms, certain PLMVd isolates induce leaf mosaics, blotches and in the most extreme cases albinism (peach calico, PC), flower streaking, delays in foliation, flowering and ripening, deformations and decolorations of fruits, which usually present cracked sutures and enlarged roundish stones, bud necrosis, stem pitting and premature ageing of the trees, which also adopt a characteristic growing pattern (open habit). The molecular determinant for PC has been mapped at a 12-14-nt insertion that folds into a hairpin capped by a U-rich loop present only in certain variants. PLMVd is horizontally transmitted by the propagation of infected buds and to a lesser extent by pruning tools and aphids, but not by pollen; the viroid is not vertically transmitted through seed. Interesting features: This provides a suitable system for studying how a minimal non-protein-coding catalytic RNA replicates (subverting a DNA-dependent RNA polymerase to transcribe an RNA template), moves, interferes with the metabolism of its host (inciting specific symptoms and a defensive RNA silencing response) and evolves following a quasi-species model characterized by a complex spectrum of variants.

  5. Latent inhibition in schizophrenia.

    Science.gov (United States)

    Swerdlow, N R; Braff, D L; Hartston, H; Perry, W; Geyer, M A

    1996-05-01

    Latent inhibition (LI) refers to the retarded acquisition of a conditioned response that occurs if the subject being tested is first preexposed to the to-be-conditioned stimulus (CS) without the paired unconditioned stimulus (UCS). Because the 'irrelevance' of the to-be-conditioned stimulus is established during non-contingent preexposure, the slowed acquisition of the CS-UCS association is thought to reflect the process of overcoming this learned irrelevance. Latent inhibition has been reported to be diminished in acutely hospitalized schizophrenia patients. If acutely hospitalized schizophrenia patients are preexposed to the CS, they learn the association as fast as, and perhaps faster than, patients who are not preexposed to the CS. This finding has been interpreted as reflecting the inability of acute schizophrenia patients to ignore irrelevant stimuli. In this study, the LI paradigm was identical to the one used in previous reports of LI deficits in schizophrenia patients (Baruch et al., 1988). Latent inhibition was observed in normal control subjects (n = 73), including individuals identified as 'psychosis-prone' based on established screening criteria, and in anxiety (n = 19) and mood disorder (n = 13) patients. Learning scores (trials to criterion) in "acutely' hospitalized as well as "chronic' hospitalized schizophrenia patients (n = 45) were significantly elevated in both preexposed and non-preexposed subjects, compared to controls. Acute schizophrenia patients exhibited intact LI. Separate cohorts of acute and chronic schizophrenia patients (n = 23) and normal controls (n = 34) exhibited intact LI when tested in a new, easier-to-acquire computerized LI paradigm. These results fail to identify specific LI deficits in schizophrenia patients, and raise the possibility that previously observed LI deficits in schizophrenia patients may reflect, at least in part, performance deficits related to learning acquisition.

  6. Tratamiento sistémico del penfigoide cicatrizal ocular

    OpenAIRE

    María Cecilia Juri; Diego S. Fernández Romero; Martín H. Devoto; Daniel Georgiett; Jorge O. Zárate; Alejandro Malbrán

    2012-01-01

    El penfigoide cicatrizal ocular (PCO) es una enfermedad ampollar autoinmune que produce daño conjuntival grave. Se conoce poco acerca de la respuesta del PCO al tratamiento inmunosupresor. Describimos un grupo de 76 pacientes con PCO, 62 mujeres y 14 hombres. La edad media al diagnóstico fue de 67 ± 14 años, con un retraso de 7.5 ± 10 años. Sesenta se siguieron en nuestro servicio por 19 ± 21 meses. De 51 en quienes se describe la gravedad de la enfermedad al inicio del tratamiento, fue leve ...

  7. Análisis de la asociación de HLA DRB1-DQB1 y autoanticuerpos en familias con Síndrome Poliendocrino Autoinmune (APS An analysis of the relationship between HLA DRB1-DQB1 and autoantibodies, in families with autoinmune polyendocrine syndrome (APS

    Directory of Open Access Journals (Sweden)

    Silvia Botta

    2008-03-01

    Full Text Available El APS es la asociación de enfermedades endocrinas autoinmunes, con otros desórdenes autoinmunes no endocrinos, denominados componentes mayores y menores. Este síndrome se clasificó en 4 tipos. Las alteraciones de la respuesta inmune provocan fallas regulatorias de la misma; y polimorfismos de HLA, entre otros, sumado a factores adquiridos o permanentes, representan gatillos disparadores de la autoinmunidad. Nuestro objetivo fue buscar la asociación de HLA-DRB1*-DQB1* en individuos pertenecientes a dos familias, con diagnóstico en uno o más de ellos de APS, o con enfermedades autoinmunes aisladas. Determinar los anticuerpos séricos: a21-OH, aGAD y aTPO y observar la asociación con el haplotipo HLA. Estudiamos padres e hijos de dos familias, dos integrantes padecían APS tipo 2 y 3; y otros con enfermedades autoinmunes. Buscamos HLA-DRB1*-DQB1* y cuantificamos a21-OH, aTPO y aGAD. Los pacientes con APS 2 y 3 presentaron el HLA-DRB1*0301-DQB1*0201. De los individuos estudiados, 5/9 tenían este haplotipo HLA y al menos un autoanticuerpo positivo. Hallamos el factor genético en 2/3 de los integrantes con enfermedades autoinmunes correspondientes a componentes mayores. La relación observada, entre APS y HLA-DRB1*0301-DQB1*0201, aumenta la posibilidad de identificar personas en riesgo de contraer afecciones autoinmunes en grupos familiares, en los cuales algún integrante padece APS.The APS is the association of autoimmune endocrine diseases, with other non-endocrine autoimmune disorders, named mayor and minor components. This syndrome was classified in 4 types. The alterations of the immune response cause regulatory faults; and HLA polymorphisms, among others; taken in conjunction with acquired or permanent factors, these represent triggers of autoimmunity. Our objective was to find out the association of HLA-DRB1*-DQB1* in individuals belonging to two families, with diagnosis in at least one of them APS, or with isolated autoimmune

  8. Trasplante de células progenitoras hematopoyéticas en enfermedades autoinmunes Hematopoietic stem cell transplantation in autoimmune diseases

    Directory of Open Access Journals (Sweden)

    Flavio Albarracín

    2008-04-01

    Full Text Available El trasplante de células progenitoras hematopoyéticas, células con capacidad de autorrenovación y reconstitución de todos los tipos de células sanguíneas, se utiliza en el tratamiento de numerosas enfermedades potencialmente letales incluyendo leucemias y linfomas. Hoy en día es posible además aplicarlo en el tratamiento de enfermedades autoinmunes graves, como esclerosis múltiple, lupus eritematoso sistémico o esclerosis sistémica, resistentes a la terapia convencional. Estudios en modelos animales nos demuestran que la transferencia de células progenitoras hematopoyéticas podría revertir el proceso de autoinmunidad, un fenómeno que puede explicarse mediante diferentes mecanismos. El resultado de los estudios clínicos que se están llevando a cabo, así como también estudios en pacientes y modelos animales, ayudarán a determinar el rol que el transplante de células progenitoras hematopoyéticas puede jugar en el tratamiento de enfermedades autoinmunes.Transplantation of hematopoietic stem cells, which are capable of self renewal and reconstitution of all types of blood cells, can be a treatment for numerous potential lethal diseases, including leukemias and lymphomas. It may now be applicable for the treatment of severe autoimmune diseases, such as therapy-resistant multiple sclerosis, lupus and systemic sclerosis. Studies in animal models show that the transfer of hematopoietic stem cells can reverse autoimmunity. The outcome of ongoing clinical trials, as well as of studies in patients and animal models, will help to determine the role that stem-cell transplantation can play in the treatment of autoimmune diseases.

  9. Latent catalyst; Senzaisei shokubai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Epoxy resin, an important function material to support such main industries as electric and electronic devices, automobiles, civil engineering, and building construction, is demanded of development of single liquid type resin having excellent quick hardening performance and storage stability. This requirement comes from environmental problems with an intention of saving energies and reducing resin wastes. The Company, using freely its independent phase separation technology that controls molecular structure of catalysts, developed a latent catalyst having excellent storage stability and high-temperature quick hardening performance. Its major features may be summarized as follows: (1) excellent storage stability at room temperature keeping the product stable for 2.5 months or longer (2 days in conventional products); (2) quick hardening performance hardening the resin in seven seconds at 150 degrees C (equivalent to conventional products); and (3) excellent insulation performance of hardened resin at 140 degrees C of 7 times 10 {sup 13} (ohm) (center dot) cm (2 times 10 {sup 12} (ohm) (center dot) cm in conventional products) (translated by NEDO)

  10. Fast discriminative latent Dirichlet allocation

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the code for fast discriminative latent Dirichlet allocation, which is an algorithm for topic modeling and text classification. The related paper is at...

  11. The Infinite Latent Events Model

    CERN Document Server

    Wingate, David; Roy, Daniel; Tenenbaum, Joshua

    2012-01-01

    We present the Infinite Latent Events Model, a nonparametric hierarchical Bayesian distribution over infinite dimensional Dynamic Bayesian Networks with binary state representations and noisy-OR-like transitions. The distribution can be used to learn structure in discrete timeseries data by simultaneously inferring a set of latent events, which events fired at each timestep, and how those events are causally linked. We illustrate the model on a sound factorization task, a network topology identification task, and a video game task.

  12. Tiroiditis autoinmune inducida por interferón en pacientes con infección por virus de la hepatitis C. Interferon-induced autoimmune thyroiditis in a patient with hepatitis C virus infection

    Directory of Open Access Journals (Sweden)

    José L. Pinto

    2011-06-01

    Full Text Available Se reporta el caso de un varón de 43 años de edad, sin antecedentes patológicos de importancia, que acudió por elevación asintomática de la alanino aminotransferasa (ALT. El paciente negó ser bebedor crónico de alcohol. Se hizo el diagnóstico serológico de infección activa por hepatitis C y la biopsia de hígado reveló inflamación crónica activa. Con estos resultados, se inició tratamiento con interferón-alfa y ribavirina. Durante el tratamiento de 48 semanas, el paciente presentó anticuerpos antitiroideos positivos con variaciones en sus niveles de tirotropina (TSH y hormonas tiroideas. En el seguimiento postratamiento, el paciente continuó con hipertiroidismo por enfermedad de Graves. La tiroiditis autoinmune es una complicación frecuente del uso de interferón en pacientes con hepatitis C. En algunos casos se presenta como hipertiroidismo por enfermedad de Graves. Se debe evaluar la función tiroidea y los anticuerpos antitiroideos antes y durante el tratamiento con interferón.A 43 year old man presented with asymptomatic elevation of alanine aminotransferase (ALT and no relevant past history. The patient denied being a chronic alcohol drinker. Work-up revealed an active hepatitis C, and liver biopsy showed active inflammation. Treatment was started with interferon-alfa and ribavirin. During the 48 weeks of treatment, the patient developed positive thyroid antibodies with varying level of thyrotropin (TSH and thyroid hormones. At follow-up after treatment, the patient continued with hyperthyroidism due to Graves’ disease. Autoimmune thyroiditis is a common complication of using interferon in patients with hepatitis C. In some cases, it is presented as hyperthyroidism because of Graves’ disease. Thyroid function and thyroid antibodies should be evaluated before and during treatment with interferon.

  13. Latent geometry of bipartite networks

    Science.gov (United States)

    Kitsak, Maksim; Papadopoulos, Fragkiskos; Krioukov, Dmitri

    2017-03-01

    Despite the abundance of bipartite networked systems, their organizing principles are less studied compared to unipartite networks. Bipartite networks are often analyzed after projecting them onto one of the two sets of nodes. As a result of the projection, nodes of the same set are linked together if they have at least one neighbor in common in the bipartite network. Even though these projections allow one to study bipartite networks using tools developed for unipartite networks, one-mode projections lead to significant loss of information and artificial inflation of the projected network with fully connected subgraphs. Here we pursue a different approach for analyzing bipartite systems that is based on the observation that such systems have a latent metric structure: network nodes are points in a latent metric space, while connections are more likely to form between nodes separated by shorter distances. This approach has been developed for unipartite networks, and relatively little is known about its applicability to bipartite systems. Here, we fully analyze a simple latent-geometric model of bipartite networks and show that this model explains the peculiar structural properties of many real bipartite systems, including the distributions of common neighbors and bipartite clustering. We also analyze the geometric information loss in one-mode projections in this model and propose an efficient method to infer the latent pairwise distances between nodes. Uncovering the latent geometry underlying real bipartite networks can find applications in diverse domains, ranging from constructing efficient recommender systems to understanding cell metabolism.

  14. Lengua plicata: debut del síndrome de Melkersson-Rosenthal

    OpenAIRE

    Crespo Escudero, P.; Ibáñez Muñoz, Cristina; Tejero Cavero, M.; Salcedo de la Cruz, W.; Escobar Martínez, M.

    2011-01-01

    [ES] Introducción: De las múltiples causas de parálisis faciales, uni o bilaterales, la gran dominadora es la parálisis de Bell o idiopática (40-75%). Melkersson (1928) y Rosenthal (1930) describieron este síndrome, todavía de etiopatogenia desconocida; algunos autores defienden la hipótesis autoinmune (mejora con corticoides), la infecciosa, o la genética (alteraciones en el brazo corto del cromosoma 9). Se estima una prevalencia entre la población general del 0,08%, sin objetiva...

  15. Biomarkers of latent TB infection

    DEFF Research Database (Denmark)

    Ruhwald, Morten; Ravn, Pernille

    2009-01-01

    For the last 100 years, the tuberculin skin test (TST) has been the only diagnostic tool available for latent TB infection (LTBI) and no biomarker per se is available to diagnose the presence of LTBI. With the introduction of M. tuberculosis-specific IFN-gamma release assays (IGRAs), a new area...... of in vitro immunodiagnostic tests for LTBI based on biomarker readout has become a reality. In this review, we discuss existing evidence on the clinical usefulness of IGRAs and the indefinite number of potential new biomarkers that can be used to improve diagnosis of latent TB infection. We also present...... early data suggesting that the monocyte-derived chemokine inducible protein-10 may be useful as a novel biomarker for the immunodiagnosis of latent TB infection....

  16. Modeling Relational Data via Latent Factor Blockmodel

    CERN Document Server

    Gao, Sheng; Gallinari, Patrick

    2012-01-01

    In this paper we address the problem of modeling relational data, which appear in many applications such as social network analysis, recommender systems and bioinformatics. Previous studies either consider latent feature based models but disregarding local structure in the network, or focus exclusively on capturing local structure of objects based on latent blockmodels without coupling with latent characteristics of objects. To combine the benefits of the previous work, we propose a novel model that can simultaneously incorporate the effect of latent features and covariates if any, as well as the effect of latent structure that may exist in the data. To achieve this, we model the relation graph as a function of both latent feature factors and latent cluster memberships of objects to collectively discover globally predictive intrinsic properties of objects and capture latent block structure in the network to improve prediction performance. We also develop an optimization transfer algorithm based on the general...

  17. Analysis of latent structures in linear systems

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2004-01-01

    In chemometrics the emphasis is on latent structure models. The latent structure is the part of the data that the modeling task is based upon. This paper is addressing some fundamental issues, when latent structures are used. The paper consists of three parts. The first part is concerned defining...

  18. A Multicomponent Latent Trait Model for Diagnosis

    Science.gov (United States)

    Embretson, Susan E.; Yang, Xiangdong

    2013-01-01

    This paper presents a noncompensatory latent trait model, the multicomponent latent trait model for diagnosis (MLTM-D), for cognitive diagnosis. In MLTM-D, a hierarchical relationship between components and attributes is specified to be applicable to permit diagnosis at two levels. MLTM-D is a generalization of the multicomponent latent trait…

  19. Caracterización clínicoevolutiva de la afección neurológica del síndrome de Sjögren

    OpenAIRE

    Akasbi Montalvo, Miriam

    2012-01-01

    Los artículos que se han incluido en esta Tesis Doctoral se centran en el estudio y caracterización de la afección neurológica que presentan los pacientes con Síndrome de Sjögren (SS) primario, incluyendo la evaluación tanto de la afección del sistema nervioso central como del sistema nervioso periférico en una cohorte de pacientes que ha sido estudiada de forma estandarizada y prospectiva en el Servicio de Enfermedades Autoinmunes del Hospital Clínic de Barcelona desde principios de los años...

  20. Estudio numérico de combustión latente en flujo directo

    OpenAIRE

    Rein, Guillermo; Torero, José Luis; Ellzey, Janet

    2002-01-01

    Este artículo presenta los resultados del estudio numérico del proceso de combustión latente en flujo directo. La combustión latente es una reacción exotérmica sin llama que se propaga en combustibles porosos. El estudio se basa en el modelo transitorio desarrollado en la Universidad de Texas en Austin, pero ampliado con varias modificaciones. En el modelo se resuelven las ecuaciones de conservación de la energía y la masa. La cinética química se modela con un esquema simplificado de tr...

  1. Evaluación del estado de salud y nutricional de pacientes celiacos de la Comunidad Valenciana

    OpenAIRE

    Pelegrí Calvo, Cristina

    2011-01-01

    INTRODUCCIÓN La enfermedad celíaca es una enfermedad autoinmune caracterizada por una inflamación crónica de la parte proximal del intestino delgado, causada por la exposición de una proteína vegetal llamada gluten de algunos cereales en la dieta: trigo, cebada, centeno y posiblemente avena. Debido a los cambios en la estructura y función de la mucosa del intestino delgado, se pierde la capacidad de digerir y absorber los nutrientes de la comida. La principal causa de este trastorno e...

  2. Latent geometry of bipartite networks

    CERN Document Server

    Kitsak, Maksim; Krioukov, Dmitri

    2016-01-01

    Despite the abundance of bipartite networked systems, their organizing principles are less studied, compared to unipartite networks. Bipartite networks are often analyzed after projecting them onto one of the two sets of nodes. As a result of the projection, nodes of the same set are linked together if they have at least one neighbor in common in the bipartite network. Even though these projections allow one to study bipartite networks using tools developed for unipartite networks, one-mode projections lead to significant loss of information and artificial inflation of the projected network with fully connected subgraphs. Here we pursue a different approach for analyzing bipartite systems that is based on the observation that such systems have a latent metric structure: network nodes are points in a latent metric space, while connections are more likely to form between nodes separated by shorter distances. This approach has been developed for unipartite networks, and relatively little is known about its appli...

  3. Advancement of Latent Trait Theory.

    Science.gov (United States)

    1988-02-01

    Estimation with the Multiple-Choice Test Item. American Educational Research Association Meeting, New Orleans, 1984. (Coauthorship with Paul S. Changas...Chicago, 1985. U. S. A. (Coauthorship with Paul S. Changas) (10) Expansion of the General Model for the Homogeneous Case of the Continuous Response Level...17-20. [2] Lazarsfeld , P. F. Latent structure analysis. In S. Koch (Ed.), Psychology: a study of a science, Volume 3. McGraw-Hill, 1959, pages 476-542

  4. Latent heat of vehicular motion

    Science.gov (United States)

    Ahmadi, Farzad; Berrier, Austin; Habibi, Mohammad; Boreyko, Jonathan

    2016-11-01

    We have used the thermodynamic concept of latent heat, where a system loses energy due to a solid-to-liquid phase transition, to study the flow of a group of vehicles moving from rest. During traffic flow, drivers keep a large distance from the car in front of them to ensure safe driving. When a group of cars comes to a stop, for example at a red light, drivers voluntarily induce a "phase transition" from this "liquid phase" to a close-packed "solid phase." This phase transition is motivated by the intuition that maximizing displacement before stopping will minimize the overall travel time. To test the effects of latent heat on flow efficiency, a drone captured the dynamics of cars flowing through an intersection on a Smart Road where the initial spacing between cars at the red light was systematically varied. By correlating the experimental results with the Optimal Velocity Model (OVM), we find that the convention of inducing phase transitions at intersections offers no benefit, as the lag time (latent heat) of resumed flow offsets the initial increase in displacement. These findings suggest that in situations where gridlock is not an issue, drivers should not decrease their spacing during stoppages in order to maximize safety with no loss in flow efficiency.

  5. Hacia la caracterización del epítopo del autoantígeno en el Síndrome de Goodpasture

    OpenAIRE

    Gozalbo Rovira, Roberto Vicente

    2014-01-01

    El síndrome de Goodpasture (GP) es un desorden autoinmune que cursa con glomerulonefritis rápidamente progresiva y hemorragia pulmonar. El ataque inmunológico se lleva a cabo mediante (auto)-anticuerpos (anticuerpos GP) dirigidos contra el dominio C terminal, no colagenoso (NC1), de la cadena α3 del colágeno IV, presente en la membrana basal glomerular (GBM), así como en la membrana basal alveolar. Tres cadenas α se asocian para construir una molécula de colágeno IV, que recibe el nombre de p...

  6. Anemia hemolítica autoinmune en un niño con hepatitis de células gigantes Autoimmune hemolytic anemia in an infant with giant cell hepatitis

    OpenAIRE

    Jessica Gómez; Kathia Valverde

    2012-01-01

    La asociación de anemia hemolítica autoinmune (AHAI) con hepatitis de células gigantes (HCG) es un trastorno raro en la infancia. Son pocos los casos reportados y la gran mayoría fallecen a pesar de transplante hepático. La AHAI usualmente precede el desarrollo de la afección hepática. El diagnóstico temprano de esta asociación y el inicio de terapia inmunosupresora previene la progresión de la enfermedad.Autoimmune hemolytic anemia (AIHA) associated with giant cell hepatitis (GCH) is a rare ...

  7. Latent herpesvirus infection arms NK cells.

    Science.gov (United States)

    White, Douglas W; Keppel, Catherine R; Schneider, Stephanie E; Reese, Tiffany A; Coder, James; Payton, Jacqueline E; Ley, Timothy J; Virgin, Herbert W; Fehniger, Todd A

    2010-06-03

    Natural killer (NK) cells were identified by their ability to kill target cells without previous sensitization. However, without an antecedent "arming" event, NK cells can recognize, but are not equipped to kill, target cells. How NK cells become armed in vivo in healthy hosts is unclear. Because latent herpesviruses are highly prevalent and alter multiple aspects of host immunity, we hypothesized that latent herpesvirus infection would arm NK cells. Here we show that NK cells from mice latently infected with Murid herpesvirus 4 (MuHV-4) were armed as evidenced by increased granzyme B protein expression, cytotoxicity, and interferon-gamma production. NK-cell arming occurred rapidly in the latently infected host and did not require acute viral infection. Furthermore, NK cells armed by latent infection protected the host against a lethal lymphoma challenge. Thus, the immune environment created by latent herpesvirus infection provides a mechanism whereby host NK-cell function is enhanced in vivo.

  8. Latent semantics as cognitive components

    DEFF Research Database (Denmark)

    Petersen, Michael Kai; Mørup, Morten; Hansen, Lars Kai

    2010-01-01

    Cognitive component analysis, defined as an unsupervised learning of features resembling human comprehension, suggests that the sensory structures we perceive might often be modeled by reducing dimensionality and treating objects in space and time as linear mixtures incorporating sparsity...... emotional responses can be encoded in words, we propose a simplified cognitive approach to model how we perceive media. Representing song lyrics in a vector space of reduced dimensionality using LSA, we combine bottom-up defined term distances with affective adjectives, that top-down constrain the latent......, which we suggest might function as cognitive components for perceiving the underlying structure in lyrics....

  9. Latent methane in fossil coals

    Energy Technology Data Exchange (ETDEWEB)

    A.D. Alexeev; E.V. Ulyanova; G.P. Starikov; N.N. Kovriga [Academy of Sciences of Ukraine, Donetsk (Ukraine). Institute for Physics of Mining Processes

    2004-07-01

    It is established experimentally using 1H NMR wide line spectroscopy that methane can exist in coals not only in open or closed porosity and fracture systems but also in solid solutions in coal substance, in particular, under methane pressure 2 MPa or higher. Methane dissolved in coal minerals reversibly modifies their lattice parameters as determined from X-ray diffraction analysis. Co-existence of these methane forms in fossil coals causes multi-step desorption kinetics. It is shown experimentally that the long-term latent methane desorption is effected mainly by closed porosity, which in turn is determined by coal rank. 21 refs., 3 figs., 2 tabs.

  10. Enhanced latent inhibition in high schizotypy individuals

    OpenAIRE

    Granger, Kiri T.; Moran, Paula M.; Buckley, Matthew G.; Haselgrove, Mark

    2016-01-01

    Latent inhibition refers to a retardation in learning about a stimulus that has been rendered familiar by non-reinforced preexposure, relative to a non-preexposed stimulus. Latent inhibition has been shown to be inversely correlated with schizotypy, and abnormal in people with schizophrenia, but these findings are inconsistent. One potential contributing factor to this inconsistency is that many tasks that purport to measure latent inhibition are confounded by alternative effects that also re...

  11. Bayesian variable selection for latent class models.

    Science.gov (United States)

    Ghosh, Joyee; Herring, Amy H; Siega-Riz, Anna Maria

    2011-09-01

    In this article, we develop a latent class model with class probabilities that depend on subject-specific covariates. One of our major goals is to identify important predictors of latent classes. We consider methodology that allows estimation of latent classes while allowing for variable selection uncertainty. We propose a Bayesian variable selection approach and implement a stochastic search Gibbs sampler for posterior computation to obtain model-averaged estimates of quantities of interest such as marginal inclusion probabilities of predictors. Our methods are illustrated through simulation studies and application to data on weight gain during pregnancy, where it is of interest to identify important predictors of latent weight gain classes.

  12. Inmunopatogenia del pénfigo vulgar y el pénfigo foliáceo = Immunopathogenesis of pemphigus vulgaris and pemphigus foliaceus

    OpenAIRE

    Valencia Ocampo, Óscar Jairo; Velásquez Lopera, Margarita María

    2011-01-01

    El pénfigo vulgar y el pénfigo foliáceo son enfermedades ampollosas autoinmunes mediadas por autoanticuerpos dirigidos contra proteínas de los desmosomas, las desmogleínas 1 y 3. Están asociadas con moléculas del complejo mayor de histocompatibilidad (HLA) que por su estructura tienen la capacidad de presentar péptidos antigénicos de las desmogleínas. En los individuos afectados se han descrito la presencia de linfocitos T y B autorreactivos y alteraciones en la regulación del sistema inmune ...

  13. Learning Latent Structure in Complex Networks

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai

    such as the Modularity, it has recently been shown that latent structure in complex networks is learnable by Bayesian generative link distribution models (Airoldi et al., 2008, Hofman and Wiggins, 2008). In this paper we propose a new generative model that allows representation of latent community structure...

  14. Introduction to Latent Class Analysis with Applications

    Science.gov (United States)

    Porcu, Mariano; Giambona, Francesca

    2017-01-01

    Latent class analysis (LCA) is a statistical method used to group individuals (cases, units) into classes (categories) of an unobserved (latent) variable on the basis of the responses made on a set of nominal, ordinal, or continuous observed variables. In this article, we introduce LCA in order to demonstrate its usefulness to early adolescence…

  15. Sampling Weights in Latent Variable Modeling

    Science.gov (United States)

    Asparouhov, Tihomir

    2005-01-01

    This article reviews several basic statistical tools needed for modeling data with sampling weights that are implemented in Mplus Version 3. These tools are illustrated in simulation studies for several latent variable models including factor analysis with continuous and categorical indicators, latent class analysis, and growth models. The…

  16. Latent Class and Latent Transition Analysis With Applications in the Social, Behavioral, and Health Sciences

    CERN Document Server

    Collins, Linda M

    2010-01-01

    One of the few books on latent class analysis (LCA) and latent transition analysis (LTA) with a comprehensive treatment of longitudinal latent class models, Latent Class and Latent Transition Analysis reflects improvements in statistical computing as the most up-to-date reference for theoretical, technical, and practical issues in cross-sectional and longitudinal data. Plentiful examples enable the reader to acquire a thorough conceptual and technical understanding and to apply techniques to address empirical research questions. Researchers seeking an advanced introduction to LCA and LTA and g

  17. Latent inhibition in human adults without masking.

    Science.gov (United States)

    Escobar, Martha; Arcediano, Francisco; Miller, Ralph R

    2003-09-01

    Latent inhibition refers to attenuated responding to Cue X observed when the X-outcome pairings are preceded by X-alone presentations. It has proven difficult to obtain in human adults unless the preexposure (X-alone) presentations are embedded within a masking (i.e., distracting) task. The authors hypothesized that the difficulty in obtaining latent inhibition with unmasked tasks is related to the usual training procedures, in which the preexposure and conditioning experiences are separated by a set of instructions. Experiment 1 reports latent inhibition without masking in a task in which preexposure and conditioning occur without interruption. Experiments 2 and 3 demonstrate that this attenuation in responding to target Cue X does not pass a summation test for conditioned inhibition and is context specific, thereby confirming that it is latent inhibition. Experiments 3 and 4 confirm that introducing instructions between preexposure and conditioning disrupts latent inhibition.

  18. Quality of life of patients with autoimmune diseases submitted to bone marrow transplantation: a longitudinal study Calidad de vida de pacientes con enfermedades autoinmunes sometidos a transplante de médula ósea: un estudio longitudinal Qualidade de vida de pacientes com doenças auto-imunes submetidos ao transplante de medula óssea: um estudo longitudinal

    Directory of Open Access Journals (Sweden)

    Fabio Augusto Bronzi Guimarães

    2008-10-01

    Full Text Available This study aimed to assess the quality of life of patients with autoimmune diseases (AID submitted to Bone Marrow Transplantation (BMT at two different moments: when the patient is admitted at the hospital and at the moment of hospital discharge (30 days after the transplantation. Patients who attended the BMT unit, were older than 18 years, with conditions and availability to voluntarily collaborate to the study were selected. Data were collected through a semi-structured interview and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36. The sample consisted of 19 patients attended at a university hospital in the interior of São Paulo State, Brazil. The collected data suggest these patients' quality of life is reduced before the realization of the transplantation, followed by a progression in their diseases. Immediately after the transplantation, an improved capacity to perform daily activities is observed, as well as a renewed possibility of making future plans.El objetivo de este estudio fue evaluar la calidad de vida de pacientes con enfermedades auto-inmunes (EAI, sometidos al Transplante de Médula Ósea (TMO, en dos momentos distintos: en la admisión del paciente y durante la ocasión del alta hospitalaria (30 días después del transplante. Fueron seleccionados pacientes atendidos en la unidad de TMO, mayores de 18 años, que presentaron condiciones y disponibilidad para colaborar voluntariamente. Para recolectar los datos se utilizó un cuestionario de entrevista semi-estructurado y el Cuestionario de Evaluación de Calidad de Vida - SF-36. La muestra fue compuesta por 19 pacientes atendidos en un hospital-escuela del interior del Estado de San Pablo, Brasil. Los datos obtenidos sugieren depreciación en la calidad de vida de esos pacientes antes de la realización del transplante, acompañada de la progresión de sus enfermedades. Inmediatamente después del transplante ya se observa una percepción de mejoría en la

  19. Apoptosis de las células beta del páncreas durante la diabetes de tipo i

    OpenAIRE

    Manrique, Camila; Silva, Diego G.

    2014-01-01

    La diabetes de tipo 1 se produce como resultadode la destrucción de las células â del páncreas.Durante la progresión de la enfermedad las célulasâ se ven crónicamente atacadas por uninfiltrado inflamatorio de tipo autoinmune congran cantidad de productos entre los cuales seencuentran citocinas y derivados de la oxidación.Estos compuestos son dañinos para la célulaâ, y la obligan a montar mecanismos de defensapara contrarrestar el ataque inmunológicoinespecífico. Sin embargo, y debido a lacron...

  20. Asociación HLA y artritis reumatoidea juvenil en busca de las bases moleculares dependiente del MHC /

    OpenAIRE

    Garavito de Egea, Gloria

    2004-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada Artritis reumatoidea Juvenil (ARJ) es una enfermedad inflamatoria crónica, autoinmune que afecta a mas de una articulación en lugar y numero. Es una de las enfermedades más comunes en la consulta pediátrica reumatológica y una de las menos estudiadas desde el punto de vista inmunogenetico. En la literatura se ha reportado varias asociaciones de (HLA) Antigenos de Leucocitos Humanos y ARJ con diferentes grupos étnicos, so...

  1. Fiebre amarilla: un peligro latente

    Directory of Open Access Journals (Sweden)

    Marvin Yglesias-Rosales

    2005-07-01

    Full Text Available La fiebre amarilla es una zoonosis, aguda, febril que se encuentra catalogada como una fiebre hemorrágica potencialmente mortal. Es causada por un arbovirus y transmitida por un artrópodo del cual se conocen dos modalidades epidemiológicas, con un área endémica que corresponde a la mayoría de América del Sur y parte del continente africano. En Costa Rica la última epidemia de fiebre amarilla ocurrió a principios de los años cincuenta. La fisiopatología de la fiebre amarilla no es bien conocida. La mayoría de las infecciones son sintomáticas, y tienen una alta mortalidad que varia según la epidemia. El diagnóstico se confirma de forma definitiva con la serología y aunque éste examen no se realiza en el país, las muestras de los casos sospechosos son enviadas a laboratorios panameños. Con base en su gran mortalidad y a la ausencia de un tratamiento específico, es obvio que el camino a seguir en el manejo de la fiebre amarilla es la prevención mediante las vacunaciones masivas en las áreas endémicas y grupos de riesgo, así como el control del vector. La fiebre amarilla sigue siendo una entidad que afecta considerablemente la salud pública en varios países del mundo; Costa Rica reúne un conjunto de condiciones que facilitarían su aparición y propagación, por lo que es una patología cuyas características convendría mantener en mente

  2. Anemia hemolítica autoinmune en un niño con hepatitis de células gigantes Autoimmune hemolytic anemia in an infant with giant cell hepatitis

    Directory of Open Access Journals (Sweden)

    Jessica Gómez

    2012-12-01

    Full Text Available La asociación de anemia hemolítica autoinmune (AHAI con hepatitis de células gigantes (HCG es un trastorno raro en la infancia. Son pocos los casos reportados y la gran mayoría fallecen a pesar de transplante hepático. La AHAI usualmente precede el desarrollo de la afección hepática. El diagnóstico temprano de esta asociación y el inicio de terapia inmunosupresora previene la progresión de la enfermedad.Autoimmune hemolytic anemia (AIHA associated with giant cell hepatitis (GCH is a rare disorder in infants. Few cases have been reported and despite receiving a liver transplant, there is high mortality among patients. AIHA usually precedes the development of liver disease. Early recognition of this association and the administration of immunosuppressive therapy prevent progression of the disease. Keywords: Autoimmune hemolytic anemia, giant cell hepatitis La asociación de anemia hemolítica autoinmune (AHAI con hepatitis de células gigantes (HCG es un trastorno raro en la infancia. Son pocos los casos reportados y la gran mayoría fallecen por fallo hepático, a pesar de trasplante. La AHAI suele preceder el desarrollo de la afección hepática. El diagnóstico temprano de esta asociación y el inicio de terapia inmunosupresora evitan la progresión de la enfermedad. Se reporta un niño de 1 año de edad al que se le diagnosticó AHAI al mes y medio de edad y luego desarrolló HCG. Para su manejo, ameritó terapia inmunosupresora con corticoesteroides, inmunoglobulina intravenosa, anticuerpo monoclonal anti-CD20 (Rituximab y, además, plasmeferésis.

  3. First Versus Second Order Latent Growth Curve Models: Some Insights From Latent State-Trait Theory

    OpenAIRE

    Geiser, Christian; Keller, Brian; Lockhart, Ginger

    2013-01-01

    First order latent growth curve models (FGMs) estimate change based on a single observed variable and are widely used in longitudinal research. Despite significant advantages, second order latent growth curve models (SGMs), which use multiple indicators, are rarely used in practice, and not all aspects of these models are widely understood. In this article, our goal is to contribute to a deeper understanding of theoretical and practical differences between FGMs and SGMs. We define the latent ...

  4. Expected Classification Accuracy using the Latent Distribution

    Directory of Open Access Journals (Sweden)

    Fanmin Guo

    2006-10-01

    Full Text Available Rudner (2001, 2005 proposed a method for evaluating classification accuracy in tests based on item response theory (IRT. In this paper, a latent distribution method is developed. For comparison, both methods are applied to a set of real data from a state test. While the latent distribution method relaxes several of the assumptions needed to apply Rudner's method, both approaches yield extremely comparable results. A simplified approach for applying Rudner's method and a short SPSS routine are presented.

  5. Handbook of latent variable and related models

    CERN Document Server

    Lee, Sik-Yum

    2011-01-01

    This Handbook covers latent variable models, which are a flexible class of models for modeling multivariate data to explore relationships among observed and latent variables.- Covers a wide class of important models- Models and statistical methods described provide tools for analyzing a wide spectrum of complicated data- Includes illustrative examples with real data sets from business, education, medicine, public health and sociology.- Demonstrates the use of a wide variety of statistical, computational, and mathematical techniques.

  6. Habituation, latent inhibition, and extinction.

    Science.gov (United States)

    Jordan, Wesley P; Todd, Travis P; Bucci, David J; Leaton, Robert N

    2015-06-01

    In two conditioned suppression experiments with a latent inhibition (LI) design, we measured the habituation of rats in preexposure, their LI during conditioning, and then extinction over days. In the first experiment, lick suppression, the preexposed group (PE) showed a significant initial unconditioned response (UR) to the target stimulus and significant long-term habituation (LTH) of that response over days. The significant difference between the PE and nonpreexposed (NPE) groups on the first conditioning trial was due solely to the difference in their URs to the conditioned stimulus (CS)-a habituated response (PE) and an unhabituated response (NPE). In the second experiment, bar-press suppression, little UR to the target stimulus was apparent during preexposure, and no detectable LTH. Thus, there was no difference between the PE and NPE groups on the first conditioning trial. Whether the UR to the CS confounds the interpretation of LI (Exp. 1) or not (Exp. 2) can only be known if the UR is measured. In both experiments, LI was observed in acquisition. Also in both experiments, rats that were preexposed and then conditioned to asymptote were significantly more resistant to extinction than were the rats not preexposed. This result contrasts with the consistently reported finding that preexposure either produces less resistance to extinction or has no effect on extinction. The effect of stimulus preexposure survived conditioning to asymptote and was reflected directly in extinction. These two experiments provide a cautionary procedural note for LI experiments and have shown an unexpected extinction effect that may provide new insights into the interpretation of LI.

  7. Efecto neuroprotector de la coadministración del factor de crecimiento epidérmico y el péptido-6 liberador de hormona de crecimiento

    OpenAIRE

    García del Barco Herrera, Diana

    2012-01-01

    Los enfoques terapéuticos dirigidos a la neuroprotección en el campo de la neurología clínica constituyen grandes retos para la medicina contemporánea. La fisiopatología compleja de las enfermedades neurodegenerativas, autoinmunes e isquémicas del sistema nervioso central es una de las causas que explican por qué, aun existiendo numerosas investigaciones en este campo, no se ha logrado disponer de alternativas terapéuticas exitosas. El objetivo de este trabajo fue analizar el efecto terapé...

  8. Fiebre amarilla: un peligro latente

    Directory of Open Access Journals (Sweden)

    Marvin Yglesias-Rosales

    2005-07-01

    Full Text Available La fiebre amarilla es una zoonosis, aguda, febril que se encuentra catalogada como una fiebre hemorrágica potencialmente mortal. Es causada por un arbovirus y transmitida por un artrópodo del cual se conocen dos modalidades epidemiológicas, con un área endémica que corresponde a la mayoría de América del Sur y parte del continente africano. En Costa Rica la última epidemia de fiebre amarilla ocurrió a principios de los años cincuenta. La fisiopatología de la fiebre amarilla no es bien conocida. La mayoría de las infecciones son sintomáticas, y tienen una alta mortalidad que varia según la epidemia. El diagnóstico se confirma de forma definitiva con la serología y aunque éste examen no se realiza en el país, las muestras de los casos sospechosos son enviadas a laboratorios panameños. Con base en su gran mortalidad y a la ausencia de un tratamiento específico, es obvio que el camino a seguir en el manejo de la fiebre amarilla es la prevención mediante las vacunaciones masivas en las áreas endémicas y grupos de riesgo, así como el control del vector. La fiebre amarilla sigue siendo una entidad que afecta considerablemente la salud pública en varios países del mundo; Costa Rica reúne un conjunto de condiciones que facilitarían su aparición y propagación, por lo que es una patología cuyas características convendría mantener en menteYellow fever is an acute febrile zoonosis, catalogued as a hemorrhagic fever that is potentially deadly. It is caused by an arbovirus and transmitted by an arthropod; there are two known epidemiologic modalities, and it has an endemic area that comprises most of South America and part of the African continent. In Costa Rica the last outbreak of yellow fever was in the fifties. The physiopathology of yellow fever is not well known. Most of the infections are symptomatic and have a high mortality that varies from outbreak to outbreak. The diagnosis is definitely confirmed by serology and

  9. Human Cytomegalovirus Manipulation of Latently Infected Cells

    Directory of Open Access Journals (Sweden)

    John H. Sinclair

    2013-11-01

    Full Text Available Primary infection with human cytomegalovirus (HCMV results in the establishment of a lifelong infection of the host which is aided by the ability of HCMV to undergo a latent infection. One site of HCMV latency in vivo is in haematopoietic progenitor cells, resident in the bone marrow, with genome carriage and reactivation being restricted to the cells of the myeloid lineage. Until recently, HCMV latency has been considered to be relatively quiescent with the virus being maintained essentially as a “silent partner” until conditions are met that trigger reactivation. However, advances in techniques to study global changes in gene expression have begun to show that HCMV latency is a highly active process which involves expression of specific latency-associated viral gene products which orchestrate major changes in the latently infected cell. These changes are argued to help maintain latent infection and to modulate the cellular environment to the benefit of latent virus. In this review, we will discuss these new findings and how they impact not only on our understanding of the biology of HCMV latency but also how they could provide tantalising glimpses into mechanisms that could become targets for the clearance of latent HCMV.

  10. INCLUSION OF THE LATENT PERSONALITY VARIABLE IN MULTINOMIAL LOGIT MODELS USING THE 16PF PSYCHOMETRIC TEST

    Directory of Open Access Journals (Sweden)

    JORGE E. CÓRDOBA MAQUILÓN

    2012-01-01

    Full Text Available Los modelos de demanda de viajes utilizan principalmente los atributos modales y las características socioeconómicas como variables explicativas. También se ha establecido que las actitudes y percepciones influyen en el comportamiento de los usuarios. Sin embargo, las variables psicológicas del individuo condicionan la conducta del usuario. En este estudio se incluyó la variable latente personalidad, en la estimación del modelo híbrido de elección discreta, el cual constituye una buena alternativa para incorporar los efectos de los factores subjetivos. La variable latente personalidad se evaluó con la prueba psicométrica 16PF de validez internacional. El artículo analiza los resultados de la aplicación de este modelo a una población de empleados y docentes universitarios, y también propone un camino para la utilización de pruebas psicométricas en los modelos híbridos de elección discreta. Nuestros resultados muestran que los modelos híbridos que incluyen variables latentes psicológicas son superiores a los modelos tradicionales que ignoran los efectos de la conducta de los usuarios.

  11. Learning with Latent Factors in Time Series

    CERN Document Server

    Jalali, Ali

    2011-01-01

    This paper considers the problem of learning, from samples, the dependency structure of a system of linear stochastic differential equations, when some of the variables are latent. In particular, we observe the time evolution of some variables, and never observe other variables; from this, we would like to find the dependency structure between the observed variables -- separating out the spurious interactions caused by the (marginalizing out of the) latent variables' time series. We develop a new method, based on convex optimization, to do so in the case when the number of latent variables is smaller than the number of observed ones. For the case when the dependency structure between the observed variables is sparse, we theoretically establish a high-dimensional scaling result for structure recovery. We verify our theoretical result with both synthetic and real data (from the stock market).

  12. Latent Fingerprint Matching: Performance Gain via Feedback from Exemplar Prints.

    Science.gov (United States)

    Arora, Sunpreet S; Liu, Eryun; Cao, Kai; Jain, Anil K

    2014-12-01

    Latent fingerprints serve as an important source of forensic evidence in a court of law. Automatic matching of latent fingerprints to rolled/plain (exemplar) fingerprints with high accuracy is quite vital for such applications. However, latent impressions are typically of poor quality with complex background noise which makes feature extraction and matching of latents a significantly challenging problem. We propose incorporating top-down information or feedback from an exemplar to refine the features extracted from a latent for improving latent matching accuracy. The refined latent features (e.g. ridge orientation and frequency), after feedback, are used to re-match the latent to the top K candidate exemplars returned by the baseline matcher and resort the candidate list. The contributions of this research include: (i) devising systemic ways to use information in exemplars for latent feature refinement, (ii) developing a feedback paradigm which can be wrapped around any latent matcher for improving its matching performance, and (iii) determining when feedback is actually necessary to improve latent matching accuracy. Experimental results show that integrating the proposed feedback paradigm with a state-of-the-art latent matcher improves its identification accuracy by 0.5-3.5 percent for NIST SD27 and WVU latent databases against a background database of 100k exemplars.

  13. Dish-mounted latent heat buffer storage

    Science.gov (United States)

    Manvi, R.

    1981-01-01

    Dish-mounted latent heat storage subsystems for Rankine, Brayton, and Stirling engines operating at 427 C, 816 C, and 816 C respectively are discussed. Storage requirements definition, conceptual design, media stability and compatibility tests, and thermal performance analyses are considered.

  14. Random Effect and Latent Variable Model Selection

    CERN Document Server

    Dunson, David B

    2008-01-01

    Presents various methods for accommodating model uncertainty in random effects and latent variable models. This book focuses on frequentist likelihood ratio and score tests for zero variance components. It also focuses on Bayesian methods for random effects selection in linear mixed effects and generalized linear mixed models

  15. Forensic Chemistry: The Revelation of Latent Fingerprints

    Science.gov (United States)

    Friesen, J. Brent

    2015-01-01

    The visualization of latent fingerprints often involves the use of a chemical substance that creates a contrast between the fingerprint residues and the surface on which the print was deposited. The chemical-aided visualization techniques can be divided into two main categories: those that chemically react with the fingerprint residue and those…

  16. Generalized Structured Component Analysis with Latent Interactions

    Science.gov (United States)

    Hwang, Heungsun; Ho, Moon-Ho Ringo; Lee, Jonathan

    2010-01-01

    Generalized structured component analysis (GSCA) is a component-based approach to structural equation modeling. In practice, researchers may often be interested in examining the interaction effects of latent variables. However, GSCA has been geared only for the specification and testing of the main effects of variables. Thus, an extension of GSCA…

  17. Charging characteristics of ionographic latent images

    Energy Technology Data Exchange (ETDEWEB)

    Fallone, B.G.; Podgorsak, E.B.

    The charging characteristics of ionographic latent images are discussed in terms of the saturation characteristics of ionographic chambers. It is shown that latent images are essentially foil electrets with surface charge densities modulated by the x-ray transmission through the object. Empirical methods for the calculation of saturation current densities and extrapolated electric fields are given. Both the saturation current density and the extrapolated field consist of two components: one, which is linear with the air gap thickness, is produced by primary photon interactions in the chamber-sensitive volume; the other, exhibiting an exponential saturation, is attributed to photoelectrons backscattered from the polarizing electrode into the chamber-sensitive volume. The minimum applied electric field needed for an optimized charge collection in the ionographic chamber is presented in terms of both the characteristic polarization time and the electret relaxation time. The maximum possible surface charge density in the latent image is calculated, first exhibiting direct proportionality with the polarizing voltage V0, and then following a V0 (1/2) dependence for voltages larger than the breakpoint voltage. The optimum exposure for latent image production is calculated. Exposures below this optimum give insufficient charge densities for subsequent development, while exposures above it degrade the image and eventually result in a uniform foil electret charged to its maximum theoretical value.

  18. Stability of latent class segments over time

    DEFF Research Database (Denmark)

    Mueller, Simone

    2011-01-01

    Dynamic stability, as the degree to which identified segments at a given time remain unchanged over time in terms of number, size and profile, is a desirable segment property which has received limited attention so far. This study addresses the question to what degree latent classes identified from...

  19. Bayesian Multitask Learning with Latent Hierarchies

    CERN Document Server

    Daumé, Hal

    2009-01-01

    We learn multiple hypotheses for related tasks under a latent hierarchical relationship between tasks. We exploit the intuition that for domain adaptation, we wish to share classifier structure, but for multitask learning, we wish to share covariance structure. Our hierarchical model is seen to subsume several previously proposed multitask learning models and performs well on three distinct real-world data sets.

  20. Thermally Stable, Latent Olefin Metathesis Catalysts

    Science.gov (United States)

    Thomas, Renee M.; Fedorov, Alexey; Keitz, Benjamin K.

    2011-01-01

    Highly thermally stable N-aryl,N-alkyl N-heterocyclic carbene (NHC) ruthenium catalysts were designed and synthesized for latent olefin metathesis. These catalysts showed excellent latent behavior toward metathesis reactions, whereby the complexes were inactive at ambient temperature and initiated at elevated temperatures, a challenging property to achieve with second generation catalysts. A sterically hindered N-tert-butyl substituent on the NHC ligand of the ruthenium complex was found to induce latent behavior toward cross-metathesis reactions, and exchange of the chloride ligands for iodide ligands was necessary to attain latent behavior during ring-opening metathesis polymerization (ROMP). Iodide-based catalysts showed no reactivity toward ROMP of norbornene-derived monomers at 25 °C, and upon heating to 85 °C gave complete conversion of monomer to polymer in less than 2 hours. All of the complexes were very stable to air, moisture, and elevated temperatures up to at least 90 °C, and exhibited a long catalyst lifetime in solution at elevated temperatures. PMID:22282652

  1. On identifiability of certain latent class models.

    NARCIS (Netherlands)

    van Wieringen, W.N.

    2005-01-01

    Blischke [1962. Moment estimators for the parameters of a mixture of two binomial distributions. Ann. Math. Statist. 33, 444-454] studies a mixture of two binomials, a latent class model. In this article we generalize this model to a mixture of two products of binomials. We show when this generalize

  2. Latent Trait Estimation: Theory vs. Practice.

    Science.gov (United States)

    Kolakowski, Donald

    Empirical results are presented as regards the implementation of a latent-trait psychometric model by means of conditional maximum likelihood estimation. Items are scored polychotomously into varying numbers of nominal categories and the test and item characteristic curves and information functions are examined. It is concluded that scoring items…

  3. CICATRIZATION OF WOUNDS : XI. LATENT PERIOD.

    Science.gov (United States)

    Carrel, A; du Noüy, P L

    1921-09-30

    1. The latent period of cicatrization varies generally from 5 to 7 days. 2. It stops abruptly and contraction starts with its maximum velocity. 3. The formula of du Noüy applies to the beginning of the contraction period as well as to the subsequent periods.

  4. Controlling for Latent Homophily in Social Networks through Inferring Latent Locations

    CERN Document Server

    Shalizi, Cosma Rohilla

    2016-01-01

    Social influence cannot be identified from purely observational data on social networks, because such influence is generically confounded with latent homophily, i.e., with a node's network partners being informative about the node's attributes and therefore its behavior. We show that {\\em if} the network grows according to either a community (stochastic block) model, or a continuous latent space model, then latent homophilous attributes can be consistently estimated from the global pattern of social ties. Moreover, these estimates are informative enough that controlling for them allows for unbiased and consistent estimation of social-influence effects in additive models. For community models, we also provide bounds on the finite-sample bias. These are the first results on the consistent estimation of social-influence effects in the presence of latent homophily, and we discuss the prospects for generalizing them.

  5. Latent mnemonic strengths are latent: a comment on Mickes, Wixted, and Wais (2007).

    Science.gov (United States)

    Rouder, Jeffrey N; Pratte, Michael S; Morey, Richard D

    2010-06-01

    Mickes, Wixted, and Wais (2007) proposed a simple test of latent strength variability in recognition memory. They asked participants to rate their confidence using either a 20-point or a 99-point strength scale and plotted distributions of the resulting ratings. They found 25% more variability in ratings for studied than for new items, which they interpreted as providing evidence that latent mnemonic strength distributions are 25% more variable for studied than for new items. We show here that this conclusion is critically dependent on assumptions--so much so that these assumptions determine the conclusions. In fact, opposite conclusions, such that study does not affect the variability of latent strength, may be reached by making different but equally plausible assumptions. Because all measurements of mnemonic strength variability are critically dependent on untestable assumptions, all are arbitrary. Hence, there is no principled method for assessing the relative variability of latent mnemonic strength distributions.

  6. Generalized latent variable modeling multilevel, longitudinal, and structural equation models

    CERN Document Server

    Skrondal, Anders

    2004-01-01

    METHODOLOGY THE OMNI-PRESENCE OF LATENT VARIABLES Introduction 'True' variable measured with error Hypothetical constructs Unobserved heterogeneity Missing values and counterfactuals Latent responses Generating flexible distributions Combining information Summary MODELING DIFFERENT RESPONSE PROCESSES Introduction Generalized linear models Extensions of generalized linear models Latent response formulation Modeling durations or survival Summary and further reading CLASSICAL LATENT VARIABLE MODELS Introduction Multilevel regression models Factor models and item respons

  7. Fingerprint Minutiae from Latent and Matching Tenprint Images

    Science.gov (United States)

    NIST Fingerprint Minutiae from Latent and Matching Tenprint Images (PC database for purchase)   NIST Special Database 27 contains latent fingerprints from crime scenes and their matching rolled fingerprint mates. This database can be used to develop and test new fingerprint algorithms, test commercial and research AFIS systems, train latent examiners, and promote the ANSI/NIST file format standard.

  8. Stochastic Approximation Methods for Latent Regression Item Response Models

    Science.gov (United States)

    von Davier, Matthias; Sinharay, Sandip

    2010-01-01

    This article presents an application of a stochastic approximation expectation maximization (EM) algorithm using a Metropolis-Hastings (MH) sampler to estimate the parameters of an item response latent regression model. Latent regression item response models are extensions of item response theory (IRT) to a latent variable model with covariates…

  9. Modelo computacional para la identificación de endofenotipos en pacientes con artritis reumatoide utilizando información del antígeno leucocitario humano HLA clase II

    OpenAIRE

    Morales Muñoz, Luis Antonio

    2014-01-01

    La Artritis Reumatoide es una enfermedad autoinmune que afecta del 0.4% al 1% de la población humana y existen marcadores genéticos implicados en esta enfermedad. Se han utilizado varios modelos de inteligencia computacional para la clasificación e identificación de endofenotipos (relación entre fenotipo y marcadores genéticos) en pacientes con Artritis Reumatoide y controles sanos a partir de información genética, principalmente el HLA DRB1 (Antígeno Leucocitario Humano), así como la teoría ...

  10. Prevalencia de infección latente tuberculosa en trabajadores sanitarios Prevalence of the latent tuberculosis infection in sanity workers

    Directory of Open Access Journals (Sweden)

    Brígido Pérez Bermúdez

    2011-03-01

    Full Text Available Introducción: En el ámbito laboral sanitario la Tuberculosis (TBC es una enfermedad considerada de elevado riesgo para la salud de los trabajadores. Objetivos: El objetivo fundamental de este trabajo consiste en estudiar la prevalencia de Infección Latente Tuberculosa (I.L.T. en dos centros hospitalarios del Área 2 de Madrid y la distribución de esta I.L.T. entre las categorías y los servicios clínicos. Material y métodos: Estudio transversal. La población analizada ha sido de 455 trabajadores sanitarios de los Hospitales Universitarios de La Princesa e Infantil del Niño Jesús. El marco temporal del estudio abarca desde los años 2006 a 2009. Las variables analizadas han sido la edad, el sexo, tipo de hospital, la categoría profesional y los servicios clínicos. Resultados: La prevalencia de I.L.T observada ha sido del 11.4 % (8.3 %-14.1 %. No se han encontrado diferencias significativas de I.L.T. entre los distintos centros sanitarios estudiados, servicios clínicos, categorías y sexo. Sí es significativa la edad con una Odds Ratio de 1.05 (1.02-1.08. Conclusiones: En nuestra área sanitaria la I.L.T en los trabajadores sanitarios es de un 10% aproximadamente, y esta no tiene relación con los puestos de trabajo sino con la edad.Introduction: In the health sector, Tuberculosis is considered as a high risk disease for workers. Objectives: The main objective of this report is to study the prevalence of the Latent Tuberculosis Infection (I.L.T. in two hospitals of the Area 2 of Madrid and the distribution of this infection among the clinical categories and services. Material and methods: Transversal study. We have analyzed 455 health workers of the University Hospital "La Princesa" and children's Hospital "El Niño Jesús". The study began in 2006 and ended in 2009. The analyzed variables have been age, sex, type of hospital, professional category and clinical services. Results: The prevalence of the observed latent tuberculosis

  11. Noisy-OR Models with Latent Confounding

    CERN Document Server

    Hyttinen, Antti; Hoyer, Patrik O

    2012-01-01

    Given a set of experiments in which varying subsets of observed variables are subject to intervention, we consider the problem of identifiability of causal models exhibiting latent confounding. While identifiability is trivial when each experiment intervenes on a large number of variables, the situation is more complicated when only one or a few variables are subject to intervention per experiment. For linear causal models with latent variables Hyttinen et al. (2010) gave precise conditions for when such data are sufficient to identify the full model. While their result cannot be extended to discrete-valued variables with arbitrary cause-effect relationships, we show that a similar result can be obtained for the class of causal models whose conditional probability distributions are restricted to a `noisy-OR' parameterization. We further show that identification is preserved under an extension of the model that allows for negative influences, and present learning algorithms that we test for accuracy, scalabili...

  12. Biomedical Literature Exploration through Latent Semantics

    Directory of Open Access Journals (Sweden)

    Hugo ARAÚJO

    2013-08-01

    Full Text Available The fast increasing amount of articles published in the biomedical field is creating difficulties in the way this wealth of information can be efficiently exploited by researchers. As a way of overcoming these limitations and potentiating a more efficient use of the literature, we propose an approach for structuring the results of a literature search based on the latent semantic information extracted from a corpus. Moreover, we show how the results of the Latent Semantic Analysis method can be adapted so as to evidence differences between results of different searches. We also propose different visualization techniques that can be applied to explore these results. Used in combination, these techniques could empower users with tools for literature guided knowledge exploration and discovery.

  13. Blocking of potentiation of latent inhibition.

    Science.gov (United States)

    Hall, Geoffrey; Rodriguez, Gabriel

    2011-01-01

    We present a theory of latent inhibition based on the Pearce-Hall (Pearce & Hall, 1980) model for classical conditioning. Its central features are (1) that the associability of a stimulus declines as it comes to predict its consequences and (2) that nonreinforced exposure to a stimulus engages an associative learning process that makes the stimulus an accurate predictor of its consequences (in this case, the occurrence of no event). A formalization of this theory is shown to accommodate the finding that preexposure in compound with another cue can potentiate latent inhibition to the target cue. It further predicts that preexposure to the added cue will eliminate the potentiation effect. An experiment using rats and the flavor-aversion procedure confirmed this prediction.

  14. Análisis molecular de los genes TAP1 y TAP2 en enfermedades autoinmunes reumatológicas (EAR

    Directory of Open Access Journals (Sweden)

    Juan Manuel Anaya

    2001-04-01

    Full Text Available

    Las EAR como la artritis reumatoidea (AR, el síndrome de Sjögren (SS y el lupus eritematoso sistémico (LES son enfermedades crónicas frecuentes. A pesar de que su origen es desconocido, existe una susceptibilidad genética (1. Los genes TAP, ubicados en el complejo mayor de histocompatibilidad clase II, codifican un dímero asociado al procesamiento antigénico, encargado de transportar péptidos hasta el retículo endoplásmico para las moléculas HLA, en particular de Clase I (2. En trabajos anteriores hemos sugerido una asociación de alelos TAP con EAR. En este estudio se analizó, en nuevos grupos de pacientes, la asociación del polimorfismo de los genes TAP a EAR.

  15. Inmunopatogenia del pénfigo vulgar y el pénfigo foliáceo = Immunopathogenesis of pemphigus vulgaris and pemphigus foliaceus

    Directory of Open Access Journals (Sweden)

    Valencia Ocampo, Óscar Jairo

    2011-09-01

    Full Text Available El pénfigo vulgar y el pénfigo foliáceo son enfermedades ampollosas autoinmunes mediadas por autoanticuerpos dirigidos contra proteínas de los desmosomas, las desmogleínas 1 y 3. Están asociadas con moléculas del complejo mayor de histocompatibilidad (HLA que por su estructura tienen la capacidad de presentar péptidos antigénicos de las desmogleínas. En los individuos afectados se han descrito la presencia de linfocitos T y B autorreactivos y alteraciones en la regulación del sistema inmune con desequilibrio de las respuestas Th1/Th2. No se conocen con precisión los mecanismos de daño pero la investigación actual indica que los anticuerpos tienen un papel patogénico, inician diferentes cascadas de señalización que provocan la acantólisis y apoptosis de los queratinocitos. El conocimiento de la inmunopatogenia de las enfermedades ampollosas autoinmunes ha permitido el desarrollo y la puesta en práctica de nuevas alternativas terapéuticas.

  16. Latent variables and route choice behavior

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo; Bekhor, Shlomo; Pronello, Cristina

    2012-01-01

    In the last decade, a broad array of disciplines has shown a general interest in enhancing discrete choice models by considering the incorporation of psychological factors affecting decision making. This paper provides insight into the comprehension of the determinants of route choice behavior by...... results illustrate that considering latent variables (i.e., memory, habit, familiarity, spatial ability, time saving skills) alongside traditional variables (e.g., travel time, distance, congestion level) enriches the comprehension of route choice behavior....

  17. Barcelona - Talent Latent 09 / Ahto Sooaru

    Index Scriptorium Estoniae

    Sooaru, Ahto

    2010-01-01

    Fotonäitusest "Talent Latent 09" Barcelonas Arts Santa Monica kunstikeskuses. Loetletud näitusel eksponeeritud fotode autorid. Pikemalt Rafael Milach'i (sünd. 1978), Lucia Ganieva, Javier Marquerie Thomas'i (sünd. 1986), Amaury da Cunha (sünd. 1976) töödest. Lühidalt ka teistest näitustest Arts Santa Monica kunstikeskuses

  18. New Treatment Regimen for Latent Tuberculosis Infection

    Centers for Disease Control (CDC) Podcasts

    2012-03-15

    In this podcast, Dr. Kenneth Castro, Director of the Division of Tuberculosis Elimination, discusses the December 9, 2011 CDC guidelines for the use of a new regimen for the treatment of persons with latent tuberculosis infection.  Created: 3/15/2012 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 3/15/2012.

  19. The latent class multitrait-multimethod model.

    Science.gov (United States)

    Oberski, Daniel L; Hagenaars, Jacques A P; Saris, Willem E

    2015-12-01

    A latent class multitrait-multimethod (MTMM) model is proposed to estimate random and systematic measurement error in categorical survey questions while making fewer assumptions than have been made so far in such evaluations, allowing for possible extreme response behavior and other nonmonotone effects. The method is a combination of the MTMM research design of Campbell and Fiske (1959), the basic response model for survey questions of Saris and Andrews (1991), and the latent class factor model of Vermunt and Magidson (2004, pp. 227-230). The latent class MTMM model thus combines an existing design, model, and method to allow for the estimation of the degree to and manner in which survey questions are affected by systematic measurement error. Starting from a general form of the response function for a survey question, we present the MTMM experimental approach to identification of the response function's parameters. A "trait-method biplot" is introduced as a means of interpreting the estimates of systematic measurement error, whereas the quality of the questions can be evaluated by item information curves and the item information function. An experiment from the European Social Survey is analyzed and the results are discussed, yielding valuable insights into the functioning of a set of example questions on the role of women in society in 2 countries.

  20. Factors associated with latent fingerprint exclusion determinations.

    Science.gov (United States)

    Ulery, Bradford T; Hicklin, R Austin; Roberts, Maria Antonia; Buscaglia, JoAnn

    2017-02-22

    Exclusion is the determination by a latent print examiner that two friction ridge impressions did not originate from the same source. The concept and terminology of exclusion vary among agencies. Much of the literature on latent print examination focuses on individualization, and much less attention has been paid to exclusion. This experimental study assesses the associations between a variety of factors and exclusion determinations. Although erroneous exclusions are more likely to occur on some images and for some examiners, they were widely distributed among images and examiners. Measurable factors found to be associated with exclusion rates include the quality of the latent, value determinations, analysis minutia count, comparison difficulty, and the presence of cores or deltas. An understanding of these associations will help explain the circumstances under which errors are more likely to occur and when determinations are less likely to be reproduced by other examiners; the results should also lead to improved effectiveness and efficiency of training and casework quality assurance. This research is intended to assist examiners in improving the examination process and provide information to the broader community regarding the accuracy, reliability, and implications of exclusion decisions.

  1. Mixture latent autoregressive models for longitudinal data

    CERN Document Server

    Bartolucci, Francesco; Pennoni, Fulvia

    2011-01-01

    Many relevant statistical and econometric models for the analysis of longitudinal data include a latent process to account for the unobserved heterogeneity between subjects in a dynamic fashion. Such a process may be continuous (typically an AR(1)) or discrete (typically a Markov chain). In this paper, we propose a model for longitudinal data which is based on a mixture of AR(1) processes with different means and correlation coefficients, but with equal variances. This model belongs to the class of models based on a continuous latent process, and then it has a natural interpretation in many contexts of application, but it is more flexible than other models in this class, reaching a goodness-of-fit similar to that of a discrete latent process model, with a reduced number of parameters. We show how to perform maximum likelihood estimation of the proposed model by the joint use of an Expectation-Maximisation algorithm and a Newton-Raphson algorithm, implemented by means of recursions developed in the hidden Mark...

  2. First Versus Second Order Latent Growth Curve Models: Some Insights From Latent State-Trait Theory.

    Science.gov (United States)

    Geiser, Christian; Keller, Brian; Lockhart, Ginger

    2013-07-01

    First order latent growth curve models (FGMs) estimate change based on a single observed variable and are widely used in longitudinal research. Despite significant advantages, second order latent growth curve models (SGMs), which use multiple indicators, are rarely used in practice, and not all aspects of these models are widely understood. In this article, our goal is to contribute to a deeper understanding of theoretical and practical differences between FGMs and SGMs. We define the latent variables in FGMs and SGMs explicitly on the basis of latent state-trait (LST) theory and discuss insights that arise from this approach. We show that FGMs imply a strict trait-like conception of the construct under study, whereas SGMs allow for both trait and state components. Based on a simulation study and empirical applications to the CES-D depression scale (Radloff, 1977) we illustrate that, as an important practical consequence, FGMs yield biased reliability estimates whenever constructs contain state components, whereas reliability estimates based on SGMs were found to be accurate. Implications of the state-trait distinction for the measurement of change via latent growth curve models are discussed.

  3. Association of interferon-γ gene polymorphisms with susceptibility to autoinmune thyroid disease%γ干扰素基因多态性与自身免疫性甲状腺疾病易感性的关系

    Institute of Scientific and Technical Information of China (English)

    龚莹; 梁军; 刘学奎; 王玉; 司冬芹; 杜振玲

    2014-01-01

    目的 探讨γ干扰素(IFN-γ)基因多态性与自身免疫性甲状腺疾病(autoinmune thyroid disease,AI-TD)发病易感性的关系.方法 选择汉族弥漫性毒性甲状腺肿(Graves disease,GD)患者(GD组)、桥本甲状腺炎(Hashimoto thyroiditis,HT)患者(HT组)和正常人(对照组)各100例,采用序列特异性引物聚合酶链反应检测等位基因和基因型.结果 GD组IFN-γ基因+874位点A等位基因的频率明显高于对照组(83.5% vs.70.5%,P<0.01);GD组IFN-γ+874 AA基因型频率显著高于对照组(72.0% vs.51.0%,P<0.01).HT组中IFN-γ+ 874位点A及T等位基因的频率与对照组之间的差异无统计学意义(P>0.05).结论 在中国汉族人群中,GD患者和正常人之间存在IFN-γ基因+874位点A等位基因分布的差异.IFN-γ基因+874位点单核苷酸多态性可能是GD的易感因素.

  4. VACUNACIÓN CONTRA EL VIRUS DEL PAPILOMA HUMANO Y AUTOINMUNIDAD

    Directory of Open Access Journals (Sweden)

    Juan-Manuel Anaya

    2014-10-01

    Full Text Available

    RESUMEN
    El desarrollo de enfermedades autoinmunes es un tema de suma importancia cuando de vacunas se trata, dado el riesgo que pueden tener éstas de favorecer fenómenos de autoinmunidad en individuos susceptibles. La relación riesgo/beneficio de desarrollar enfermedades autoinmunes luego de la vacunación contra el virus del papiloma humano (VPH aún no se ha resuelto. Los datos disponibles son limitados para ofrecer conclusiones definitivas. Dado el aumento reciente de reporte de efectos adversos, se espera que estudios con suficiente tamaño muestral, en diversas poblaciones, confirmen la seguridad de la vacunación contra el VPH en niñas con enfermedades autoinmunes. Un análisis personalizado de cada paciente, que incluya la evaluación de autoinmunidad personal y familiar, podría ser sugerido, aunque no hay estudios que demuestren que sea costo-efectivo. Por lo tanto, la farmacovigilancia permanente de esta vacuna sigue siendo de suma importancia.

    Palabras clave: Virus del papiloma humano VPH, vacunación, autoinmunidad, efectos colaterales.

    VACCINATION AGAINST HUMAN PAPILLOMAVIRUS AND AUTOIMMUNITY

    ABSTRACT
    Development of autoimmune diseases is a very important issue in relation to vaccines, because there is a risk that they might promote autoimmune phenomena in susceptible individuals. The risk: benefit ratio of developing autoimmune diseases after human papillomavirus (HPV vaccination has not yet been resolved. Data available are limited to provide definitive conclusions. Given the recent increase of adverse effect reports, studies with sufficient sample size are expected in various populations, aimed to confirm the safety of HPV vaccination in children with autoimmune diseases. A personalized analysis of each individual, including evaluation of personal and familial autoimmunity, may be suggested; however, there are no studies showing that this policy is cost

  5. Latent Viruses: A Space Travel Hazard??

    Science.gov (United States)

    Ling, P. D.; Peng, R. S.; Pierson, D.; Lednicky, J.; Butel, J. S.

    1999-01-01

    A major issue associated with long-duration space flight is the possibility of infectious disease causing an unacceptable medical risk to crew members. Our proposal is designed to gain information that addresses several issues outlined in the Immunology/Infectious disease critical path. The major hypothesis addressed is that space flight causes alterations in the immune system that may allow latent viruses which are endogenous in the human population to reactivate and shed to higher levels than normal which can affect the health of crew members during a long term space-flight mission. We will initially focus our studies on the human herpesviruses and human polyomaviruses which are important pathogens known to establish latent infections in the human population. Both primary infection and reactivation from latent infection with this group of viruses can cause a variety of illnesses that result in morbidity and occasionally mortality of infected individuals. Effective vaccines exist for only one of the eight known human herpesviruses and the vaccine itself can still reactivate from latent infection. Available antivirals are of limited use and are effective against only a few of the human herpesviruses. Although most individuals display little if any clinical consequences from latent infection, events which alter immune function such as immunosuppressive therapy following solid organ transplantation are known to increase the risk of developing complications as a result of latent virus reactivation. This proposal will measure both the frequency and magnitude of viral shedding and genome loads in the blood from humans participating in activities that serve as ground based models of space flight conditions. Our initial goal is to develop sensitive quantitative competitive PCR- based assays (QC-PCR) to detect the herpesvirus Epstein-Barr virus (EBV), and the polyomaviruses SV40, BKV, and JCV. Using these assays we will establish baseline patterns of viral genome load in

  6. Tratamiento sistémico del penfigoide cicatrizal ocular

    Directory of Open Access Journals (Sweden)

    María Cecilia Juri

    2012-04-01

    Full Text Available El penfigoide cicatrizal ocular (PCO es una enfermedad ampollar autoinmune que produce daño conjuntival grave. Se conoce poco acerca de la respuesta del PCO al tratamiento inmunosupresor. Describimos un grupo de 76 pacientes con PCO, 62 mujeres y 14 hombres. La edad media al diagnóstico fue de 67 ± 14 años, con un retraso de 7.5 ± 10 años. Sesenta se siguieron en nuestro servicio por 19 ± 21 meses. De 51 en quienes se describe la gravedad de la enfermedad al inicio del tratamiento, fue leve en 19 pacientes, moderada en 19, grave en cinco y muy grave en ocho. Las drogas mayormente prescriptas fueron dapsona en 35 pacientes, de los que 23 la discontinuaron por efectos adversos, y metotrexate en 42, de los que nueve lo suspendieron. Otros recibieron azatioprina, ciclofosfamida y ciclosporina. A 17 se les indicaron corticoides orales, además del inmunosupresor. Cuatro combinaron dos drogas para controlar la enfermedad. Tres pacientes refractarios recibieron gammaglobulina EV con buena respuesta. De 48 evaluados, 39 mostraron mejoría, ocho no tuvieron cambios y uno progresó. En nuestra experiencia, metotrexate y azatioprina son efectivos, con baja toxicidad. Dapsona es útil en casos leves, con efectos adversos frecuentes. La gammaglobulina EV fue efectiva en casos refractarios.

  7. Latent inhibition and autonomic responses: a psychophysiological approach.

    Science.gov (United States)

    Vaitl, D; Lipp, O V

    1997-10-01

    Latent inhibition, retarded learning after preexposure to the to-be-conditioned stimulus, has been implied as a tool for the investigation of attentional deficits in schizophrenia and related disorders. The present paper reviews research that used Pavlovian conditioning as indexed by autonomic responses (electrodermal, vasomotor, cardiac) to investigate latent inhibition in adult humans. Latent inhibition has been demonstrated repeatedly in healthy subjects in absence of a masking task that is required in other latent inhibition paradigms. Moreover, latent inhibition of Pavlovian conditioning is stimulus-specific and increases with an increased number of preexposure trials which mirrors results from research in animals. A reduction of latent inhibition has been shown in healthy subjects who score high on questionnaire measures of psychosis proneness and in unmedicated schizophrenic patients. The latter result was obtained in a within-subject paradigm that holds promise for research with patient samples.

  8. Encuadres noticiosos latentes bajo el paradigma positivista: propuesta de análisis factorial exploratorio

    OpenAIRE

    Sánchez Castillo, Sebastián; Mercado Sáez, María Teresa

    2013-01-01

    Producción Científica A partir del descubrimiento de los encuadres noticiosos latentes extraídos desde una formulación inductiva, se propone un análisis de contenido complejo que considere el índice de importancia de las noticias analizadas, la caracterización de la agenda temática, las funciones básicas de los encuadres y finalmente los encuadres genéricos. El desarrollo de esta propuesta metodológica se basa en el análisis en prensa de las denominadas Enfermedades Raras. P...

  9. Revelado de huellas labiales invisibles con reactivos fluorescentes Development of latent lip prints with fluorescent powders

    Directory of Open Access Journals (Sweden)

    A. Castelló Ponce

    2003-10-01

    Full Text Available La localización de huellas latentes es especialmente dificil cuando se encuentran sobre superficies porosas (por ejemplo papel. La dificultad es todavía mayor si son antiguas. Para conseguir detectarlas es necesario utilizar reactivos muy sensibles a algún componente de la huella y que formen derivados coloreados que permitan su visualización. En el caso de las huellas labiales, la presencia de lípidos en la huella hace posible su revelado utilizando compuestos del tipo de los lisocromos (Sudan III, Sudan black y Oil Red O. Sin embargo, aunque estos reactivos resultan muy útiles, en ocasiones el revelado puede no ser visible por problemas de contraste entre el color del reactivo (negro del Sudan Black o rojo del Sudan III y el Oil Red O y el de la superficie que contiene la huella. Para solucionar este problema se ha pensado en emplear reactivos fluorescentes de los que se utilizan para el revelado de huellas dactilares. Según los resultados obtenidos en las condiciones de este estudio, se puede afirmar que los reactivos fluorescentes para huellas dactilares son útiles para el revelado de huellas labiales sobre superficies porosas oscuras o multicolores.The search for latent prints is very difficult when they are placed on porous surfaces (i.e. on paper. The difficulty is even greater when the prints are old. To detect them it is necessary to use very sensitive reagents that will produce coloured products that we can detect. Lip prints contains lipids which make possible their development by using lysochrome dyes (Sudan III, Oil Red O and Sudan Black . Nonetheless, when the print is on dark or multicoloured surfaces, development could not be seen at all. This problem could be solved using fluorescent reagents. These reagents are being used for fingerprint development. The results of this work show that fluorescent powders for latent fingerprints are useful for the development of latent lip prints on porous surfaces or on multicoloured

  10. Using existing questionnaires in latent class analysis

    DEFF Research Database (Denmark)

    Nielsen, Anne Molgaard; Vach, Werner; Kent, Peter;

    2016-01-01

    BACKGROUND: Latent class analysis (LCA) is increasingly being used in health research, but optimal approaches to handling complex clinical data are unclear. One issue is that commonly used questionnaires are multidimensional, but expressed as summary scores. Using the example of low back pain (LBP...... classified into four health domains (psychology, pain, activity, and participation) using the World Health Organization's International Classification of Functioning, Disability, and Health framework. LCA was performed within each health domain using the strategies of summary-score and single-item analyses...

  11. Functional networks underlying latent inhibition learning in the mouse brain

    OpenAIRE

    Puga, Frank; Barrett, Douglas W.; Bastida, Christel C.; Gonzalez-Lima, F.

    2007-01-01

    The present study reports the first comprehensive map of brain networks underlying latent inhibition learning and the first application of structural equation modeling to cytochrome oxidase data. In latent inhibition, repeated exposure to a stimulus results in a latent form of learning that inhibits subsequent associations with that stimulus. As neuronal energy demand to form learned associations changes, so does the induction of the respiratory enzyme cytochrome oxidase. Therefore, cytochrom...

  12. Protection from Latent Inhibition Provided by a Conditioned Inhibitor

    OpenAIRE

    McConnell, Bridget L.; Wheeler, Daniel S.; Urcelay, Gonzalo P; Miller, Ralph R.

    2009-01-01

    Two conditioned suppression experiments with rats investigated the influence on latent inhibition of compounding a Pavlovian conditioned inhibitor with the target cue during preexposure treatment. Results were compared to subjects that received conventional latent inhibition training, no preexposure, or preexposure to the target cue in compound with a neutral stimulus. In Experiment 1, greater attenuation of the latent inhibition effect was observed in subjects that received target preexposur...

  13. Latent mnemonic strengths are latent : A comment on Mickes, Wixted, and Wais

    NARCIS (Netherlands)

    Rouder, J.N.; Pratte, M.S.; Morey, R.D.

    2010-01-01

    Mickes, Wixted, and Wais (2007) proposed a simple test of latent strength variability in recognition memory. They asked participants to rate their confidence using either a 20-point or a 99-point strength scale and plotted distributions of the resulting ratings. They found 25% more variability in ra

  14. Bayesian Analysis of Multivariate Latent Curve Models with Nonlinear Longitudinal Latent Effects

    Science.gov (United States)

    Song, Xin-Yuan; Lee, Sik-Yum; Hser, Yih-Ing

    2009-01-01

    In longitudinal studies, investigators often measure multiple variables at multiple time points and are interested in investigating individual differences in patterns of change on those variables. Furthermore, in behavioral, social, psychological, and medical research, investigators often deal with latent variables that cannot be observed directly…

  15. A solar air collector with integrated latent heat thermal storage

    OpenAIRE

    Klimes Lubomir; Mauder Tomas; Ostry Milan; Charvat Pavel

    2012-01-01

    Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM) was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage...

  16. Higher-Order Item Response Models for Hierarchical Latent Traits

    Science.gov (United States)

    Huang, Hung-Yu; Wang, Wen-Chung; Chen, Po-Hsi; Su, Chi-Ming

    2013-01-01

    Many latent traits in the human sciences have a hierarchical structure. This study aimed to develop a new class of higher order item response theory models for hierarchical latent traits that are flexible in accommodating both dichotomous and polytomous items, to estimate both item and person parameters jointly, to allow users to specify…

  17. A Simplified Estimation of Latent State--Trait Parameters

    Science.gov (United States)

    Hagemann, Dirk; Meyerhoff, David

    2008-01-01

    The latent state-trait (LST) theory is an extension of the classical test theory that allows one to decompose a test score into a true trait, a true state residual, and an error component. For practical applications, the variances of these latent variables may be estimated with standard methods of structural equation modeling (SEM). These…

  18. Nonlinear Latent Curve Models for Multivariate Longitudinal Data

    Science.gov (United States)

    Blozis, Shelley A.; Conger, Katherine J.; Harring, Jeffrey R.

    2007-01-01

    Latent curve models have become a useful approach to analyzing longitudinal data, due in part to their allowance of and emphasis on individual differences in features that describe change. Common applications of latent curve models in developmental studies rely on polynomial functions, such as linear or quadratic functions. Although useful for…

  19. A Review of the Latent and Manifest Benefits (LAMB) Scale

    Science.gov (United States)

    Muller, Juanita; Waters, Lea

    2012-01-01

    The latent and manifest benefits (LAMB) scale (Muller, Creed, Waters & Machin, 2005) was designed to measure the latent and manifest benefits of employment and provide a single scale to test Jahoda's (1981) and Fryer's (1986) theories of unemployment. Since its publication in 2005 there have been 13 studies that have used the scale with 5692…

  20. PROC LCA: A SAS Procedure for Latent Class Analysis

    Science.gov (United States)

    Lanza, Stephanie T.; Collins, Linda M.; Lemmon, David R.; Schafer, Joseph L.

    2007-01-01

    Latent class analysis (LCA) is a statistical method used to identify a set of discrete, mutually exclusive latent classes of individuals based on their responses to a set of observed categorical variables. In multiple-group LCA, both the measurement part and structural part of the model can vary across groups, and measurement invariance across…

  1. Latent lifestyle and mode choice decisions when travelling short distances

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo; Halldórsdóttir, Katrín; Nielsen, Otto Anker

    2016-01-01

    of a representative sample of the Danish population in the Copenhagen Region were analysed, and more specifically a latent class choice model was estimated to uncover latent lifestyle groups and choice specific travel behaviour. Results show that four lifestyle groups are identified in the population: car oriented...

  2. Incorporating direct marketing activity into latent attrition models

    NARCIS (Netherlands)

    Schweidel, David A.; Knox, George

    2013-01-01

    When defection is unobserved, latent attrition models provide useful insights about customer behavior and accurate forecasts of customer value. Yet extant models ignore direct marketing efforts. Response models incorporate the effects of direct marketing, but because they ignore latent attrition, th

  3. Gene Variants Associated with Antisocial Behaviour: A Latent Variable Approach

    Science.gov (United States)

    Bentley, Mary Jane; Lin, Haiqun; Fernandez, Thomas V.; Lee, Maria; Yrigollen, Carolyn M.; Pakstis, Andrew J.; Katsovich, Liliya; Olds, David L.; Grigorenko, Elena L.; Leckman, James F.

    2013-01-01

    Objective: The aim of this study was to determine if a latent variable approach might be useful in identifying shared variance across genetic risk alleles that is associated with antisocial behaviour at age 15 years. Methods: Using a conventional latent variable approach, we derived an antisocial phenotype in 328 adolescents utilizing data from a…

  4. A Latent Class Approach to Estimating Test-Score Reliability

    Science.gov (United States)

    van der Ark, L. Andries; van der Palm, Daniel W.; Sijtsma, Klaas

    2011-01-01

    This study presents a general framework for single-administration reliability methods, such as Cronbach's alpha, Guttman's lambda-2, and method MS. This general framework was used to derive a new approach to estimating test-score reliability by means of the unrestricted latent class model. This new approach is the latent class reliability…

  5. A LATENT TRAIT MODEL FOR DICHOTOMOUS CHOICE DATA

    NARCIS (Netherlands)

    HOIJTINK, H

    1990-01-01

    The PARELLA model is a probabilistic parallelogram model that can be used for the measurement of latent attitudes or latent preferences. The data analyzed are the dichotomous responses of persons to stimuli, with a one (zero) indicating agreement (disagreement) with the content of the stimulus. The

  6. Latent Images, Blind Comments on Photography

    Directory of Open Access Journals (Sweden)

    Jenny Feray

    2013-12-01

    Full Text Available Photographs, or images as the final result of a process, merely mark out the moment when the eye is helplessly limited to what it sees. Thus, what escapes the eye in the physical sense, i.e. what the eye will never see, is what occurs before the product- image, within the act itself. The latent image, the desire-image, unfolds throughout the duration of the photographic act. When the picture is ‘taken’, then the desire subsides until the next desire for another image arises. Based on the photographic experiment by Jerry Chan, member of a group of blind people, this article aims at rethinking the photographic act as the real- life experience of an impression process, leading the blind apprentice photographer to experience sightedness within his very flesh.  

  7. Endogenous Opioid-Masked Latent Pain Sensitization

    DEFF Research Database (Denmark)

    Pereira, Manuel P; Donahue, Renee R; Dahl, Jørgen B

    2015-01-01

    naloxone dose (0.021 mg/kg). However, while LS was consistently demonstrated in 21/24 mice, LS was only seen in 4/12 subjects. This difference is likely due to selection bias since the C57BL/6 mouse strain exhibits markedly enhanced pain sensitivity in assays of acute thermal nociception. Future......UNLABELLED: Following the resolution of a severe inflammatory injury in rodents, administration of mu-opioid receptor inverse agonists leads to reinstatement of pain hypersensitivity. The mechanisms underlying this form of latent pain sensitization (LS) likely contribute to the development...... of chronic pain, but LS has not yet been demonstrated in humans. Using a C57BL/6 mouse model of cutaneous mild heat injury (MHI) we demonstrated a dose-dependent reinstatement of pain sensitization, assessed as primary (P

  8. Unsupervised Feature Selection for Latent Dirichlet Allocation

    Institute of Scientific and Technical Information of China (English)

    Xu Weiran; Du Gang; Chen Guang; Guo Jun; Yang Jie

    2011-01-01

    As a generative model Latent Dirichlet Allocation Model,which lacks optimization of topics' discrimination capability focuses on how to generate data,This paper aims to improve the discrimination capability through unsupervised feature selection.Theoretical analysis shows that the discrimination capability of a topic is limited by the discrimination capability of its representative words.The discrimination capability of a word is approximated by the Information Gain of the word for topics,which is used to distinguish between “general word” and “special word” in LDA topics.Therefore,we add a constraint to the LDA objective function to let the “general words” only happen in “general topics”other than “special topics”.Then a heuristic algorithm is presented to get the solution.Experiments show that this method can not only improve the information gain of topics,but also make the topics easier to understand by human.

  9. Pretreatment of Latent Prints for Laser Development.

    Science.gov (United States)

    Menzel, E R

    1989-06-01

    The pretreatment procedures for laser detection of latent fingerprints is reviewed. The general features of laser detection and the operational aspects of the examination of physical evidence for laser fingerprint detection are enumerated in the initial sections. The literature review is divided into various pretreatment approaches. Cited studies prior to 1981 are primarily concerned with the demonstration of the viability of laser fingerprint detection, whereas work post-1981 addresses issues of compatibility with the traditional methods of fingerprint development, examination of difficult surfaces, and the routine implementation of laser detection by law enforcement agencies. Related topics of research, review articles, conference reports, case examinations, the research support climate, and future trends are also briefly addressed.

  10. A latent classification of male batterers.

    Science.gov (United States)

    Mauricio, Anne M; Lopez, Frederick G

    2009-01-01

    Regression latent class analysis was used to identify batterer subgroups with distinct violence patterns and to examine associations between class membership and adult attachment orientations as well as antisocial and borderline personality disorders. Results supported three batterer subgroups, with classes varying on frequency and severity of violence. The high-level violence class represented 40% of batterers, and both anxious and avoidant adult attachment orientations as well as borderline personality characteristics predicted membership in this class. The moderate-level violence class represented 35% of the batterers, and adult anxious attachment orientation was associated with membership in this class. The low-level violence class represented 25% of the sample and reported significantly less violence than other classes. Neither adult attachment orientations nor personality disorders predicted membership in this class.

  11. Targeting latent TGFβ release in muscular dystrophy.

    Science.gov (United States)

    Ceco, Ermelinda; Bogdanovich, Sasha; Gardner, Brandon; Miller, Tamari; DeJesus, Adam; Earley, Judy U; Hadhazy, Michele; Smith, Lucas R; Barton, Elisabeth R; Molkentin, Jeffery D; McNally, Elizabeth M

    2014-10-22

    Latent transforming growth factor-β (TGFβ) binding proteins (LTBPs) bind to inactive TGFβ in the extracellular matrix. In mice, muscular dystrophy symptoms are intensified by a genetic polymorphism that changes the hinge region of LTBP, leading to increased proteolytic susceptibility and TGFβ release. We have found that the hinge region of human LTBP4 was also readily proteolysed and that proteolysis could be blocked by an antibody to the hinge region. Transgenic mice were generated to carry a bacterial artificial chromosome encoding the human LTBP4 gene. These transgenic mice displayed larger myofibers, increased damage after muscle injury, and enhanced TGFβ signaling. In the mdx mouse model of Duchenne muscular dystrophy, the human LTBP4 transgene exacerbated muscular dystrophy symptoms and resulted in weaker muscles with an increased inflammatory infiltrate and greater LTBP4 cleavage in vivo. Blocking LTBP4 cleavage may be a therapeutic strategy to reduce TGFβ release and activity and decrease inflammation and muscle damage in muscular dystrophy.

  12. Latent factors and route choice behaviour

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo

    . A reliable dataset was prepared through measures of internal consistency and sampling adequacy, and data were analyzed with a proper application of factor analysis to the route choice context. For the dataset obtained from the survey, six latent constructs affecting driver behaviour were extracted and scores...... by proposing a methodology for collecting and analyzing behavioural indicators and modelling route choices of individuals driving habitually from home to their workplace. A web-based survey was designed to collect attitudinal data and observed route choices among faculty and staff members of Turin Polytechnic...... on each factor for each survey participant were calculated. Path generation algorithms were examined with respect to observed behaviour, through a measure of reproduction with deterministic techniques of the routes indicated in the answers to the survey. Results presented evidence that the majority...

  13. Latent Herpes Viral Reactivation in Astronauts

    Science.gov (United States)

    Pierson, D. L.; Mehta, S. K.; Stowe, R.

    2008-01-01

    Latent viruses are ubiquitous and reactivate during stressful periods with and without symptoms. Latent herpes virus reactivation is used as a tool to predict changes in the immune status in astronauts and to evaluate associated health risks. Methods: Viral DNA was detected by real time polymerase chain reaction in saliva and urine from astronauts before, during and after short and long-duration space flights. Results and Discussion: EpsteinBarr virus (EBV), cytomegalovirus (CMV), and varicella zoster virus (VZV) reactivated, and viral DNA was shed in saliva (EBV and VZV) or urine (CMV). EBV levels in saliva during flight were 10fold higher than baseline levels. Elevations in EBV specific CD8+ T-cells, viral antibody titers, and specific cytokines were consistent with viral reactivation. Intracellular levels of cytokines were reduced in EBVspecific Tcells. CMV, rarely present in urine of healthy individuals, was shed in urine of 27% of astronauts during all phases of spaceflight. VZV, not found in saliva of asymptomatic individuals, was found in saliva of 50% of astronauts during spaceflight and 35 days after flight. VZV recovered from astronaut saliva was found to be live, infectious virus. DNA sequencing demonstrated that the VZV recovered from astronauts was from the common European strain of VZV. Elevation of stress hormones accompanied viral reactivation indicating involvement of the hypothalmic-pituitary-adrenal and sympathetic adrenal-medullary axes in the mechanism of viral reactivation in astronauts. A study of 53 shingles patients found that all shingles patients shed VZV DNA in their saliva and the VZV levels correlated with the severity of the disease. Lower VZV levels in shingles patients were similar to those observed in astronauts. We proposed a rapid, simple, and cost-effective assay to detect VZV in saliva of patients with suspected shingles. Early detection of VZV infection allows early medical intervention.

  14. Latent Virus Reactivation in Space Shuttle Astronauts

    Science.gov (United States)

    Mehta, S. K.; Crucian, B. E.; Stowe, R. P.; Sams, C.; Castro, V. A.; Pierson, D. L.

    2011-01-01

    Latent virus reactivation was measured in 17 astronauts (16 male and 1 female) before, during, and after short-duration Space Shuttle missions. Blood, urine, and saliva samples were collected 2-4 months before launch, 10 days before launch (L-10), 2-3 hours after landing (R+0), 3 days after landing (R+14), and 120 days after landing (R+120). Epstein-Barr virus (EBV) DNA was measured in these samples by quantitative polymerase chain reaction. Varicella-zoster virus (VZV) DNA was measured in the 381 saliva samples and cytomegalovirus (CMV) DNA in the 66 urine samples collected from these subjects. Fourteen astronauts shed EBV DNA in 21% of their saliva samples before, during, and after flight, and 7 astronauts shed VZV in 7.4% of their samples during and after flight. It was interesting that shedding of both EBV and VZV increased during the flight phase relative to before or after flight. In the case of CMV, 32% of urine samples from 8 subjects contained DNA of this virus. In normal healthy control subjects, EBV shedding was found in 3% and VZV and CMV were found in less than 1% of the samples. The circadian rhythm of salivary cortisol measured before, during, and after space flight did not show any significant difference between flight phases. These data show that increased reactivation of latent herpes viruses may be associated with decreased immune system function, which has been reported in earlier studies as well as in these same subjects (data not reported here).

  15. Data on the interexaminer variation of minutia markup on latent fingerprints

    Directory of Open Access Journals (Sweden)

    Bradford T. Ulery

    2016-09-01

    Full Text Available The data in this article supports the research paper entitled “Interexaminer variation of minutia markup on latent fingerprints” [1]. The data in this article describes the variability in minutia markup during both analysis of the latents and comparison between latents and exemplars. The data was collected in the “White Box Latent Print Examiner Study,” in which each of 170 volunteer latent print examiners provided detailed markup documenting their examinations of latent-exemplar pairs of prints randomly assigned from a pool of 320 pairs. Each examiner examined 22 latent-exemplar pairs; an average of 12 examiners marked each latent.

  16. Frecuencia, características clínicas, serológicas, patrón radiológico y severidad del compromiso pulmonar intersticial en enfermedades del tejido conectivo en una cohorte de pacientes colombianos

    OpenAIRE

    Pertuz Charris, Neil Smith

    2014-01-01

    Introducción: La enfermedad pulmonar intersticial (EPI) asociada a Enfermedades del Tejido Conectivo (ETC) es una complicación asociada por el papel autoinmune inflamatorio característico de este tipo de patologías. La frecuencia de EPI en ETC es variable, siendo más frecuente como complicación en Esclerosis sistémica con patrón de Neumonía Intersticial No específica, en Artritis Reumatoide patrón de Neumonía Intersticial Usual, en Sindrome de Sjögren la Neumonía Intersticial No específica, e...

  17. Uso del Propanolol en Hipertiroidismo

    Directory of Open Access Journals (Sweden)

    Alfredo Jácome Roca

    1993-08-01

    Full Text Available

    Cuando el organismo se encuentra expuesto a concentraciones elevadas de T4 y/o de T3. La fracción libre de estas hormonas es la que ejerce su función biológica, mientras que la mayor parte de la concentración total está ligada a proteínas transportadoras, formando un reservorio hormonal tiroideo.

    El estado hipermetabólico observado en el hipertiroidismo, variable en severidad de acuerdo con niveles hormonales, causa y edad, produce síntomas que pueden relacionarse con una actividad simpático-mimética excesiva y a un aumento del catabolismo. Aunque los tratamientos clásicos del hipertiroidismo incluyen las tioureas, el yodo radiactivo y la cirugía, preferidos en forma prioritaria de acuerdo con la causa y con la edad, en la mayoría de los casos debe realizarse un bloqueo beta-adrenérgico como tratamiento coadyuvante, precisamente para antagonizar la excesiva actividad simpático-mimética (1.

    Las causas más frecuentes del síndrome hipertiroideo son la Enfermedad de Graves, el bocio no dular tóxico (anteriormente llamado Enfermedad de Plummer, el adenoma tóxico, la toroiditis subaguda de De Quervain y la tirotoxicosis factitia o la iatrogénica. Hay causas más raras como la Hashitoxicosis, los TSH-omas, los tumores trofoblásticos, el estruma ovárico y el hipertiroidismo yodo-inducido. Situaciones especiales se consideran el hipertiroidismo durante el embarazo o la cirugía, la crisis o tormenta tirotóxica y las complicaciones cardiacas.

    El Graves se caracteriza por un bocio difuso hiperfuncionante asociado a exoftalmos y mixedema pretibial, con presencia de inmunoglobulinas estimulantes de la tiroides (TSI, por lo que hace parte de la llamada Enfermedad Tiroidea Autoinmune y del Síndrome Poliglandular Autoinmune. El bocio nodular tóxico, observado en personas de mayor edad, es más bien un proceso evolutivo de un bocio presente por muchos años, con un cuadro clínico no siempre florido.

    Muchas de

  18. Tropical Gravity Wave Momentum Fluxes and Latent Heating Distributions

    Science.gov (United States)

    Geller, Marvin A.; Zhou, Tiehan; Love, Peter T.

    2015-01-01

    Recent satellite determinations of global distributions of absolute gravity wave (GW) momentum fluxes in the lower stratosphere show maxima over the summer subtropical continents and little evidence of GW momentum fluxes associated with the intertropical convergence zone (ITCZ). This seems to be at odds with parameterizations forGWmomentum fluxes, where the source is a function of latent heating rates, which are largest in the region of the ITCZ in terms of monthly averages. The authors have examined global distributions of atmospheric latent heating, cloud-top-pressure altitudes, and lower-stratosphere absolute GW momentum fluxes and have found that monthly averages of the lower-stratosphere GW momentum fluxes more closely resemble the monthly mean cloud-top altitudes rather than the monthly mean rates of latent heating. These regions of highest cloud-top altitudes occur when rates of latent heating are largest on the time scale of cloud growth. This, plus previously published studies, suggests that convective sources for stratospheric GW momentum fluxes, being a function of the rate of latent heating, will require either a climate model to correctly model this rate of latent heating or some ad hoc adjustments to account for shortcomings in a climate model's land-sea differences in convective latent heating.

  19. In vivo disruption of latent HSV by designer endonuclease therapy.

    Science.gov (United States)

    Aubert, Martine; Madden, Emily A; Loprieno, Michelle; DeSilva Feelixge, Harshana S; Stensland, Laurence; Huang, Meei-Li; Greninger, Alexander L; Roychoudhury, Pavitra; Niyonzima, Nixon; Nguyen, Thuy; Magaret, Amalia; Galleto, Roman; Stone, Daniel; Jerome, Keith R

    2016-09-08

    A large portion of the global population carries latent herpes simplex virus (HSV), which can periodically reactivate, resulting in asymptomatic shedding or formation of ulcerative lesions. Current anti-HSV drugs do not eliminate latent virus from sensory neurons where HSV resides, and therefore do not eliminate the risk of transmission or recurrent disease. Here, we report the ability of HSV-specific endonucleases to induce mutations of essential HSV genes both in cultured neurons and in latently infected mice. In neurons, viral genomes are susceptible to endonuclease-mediated mutagenesis, regardless of the time of treatment after HSV infection, suggesting that both HSV lytic and latent forms can be targeted. Mutagenesis frequency after endonuclease exposure can be increased nearly 2-fold by treatment with a histone deacetylase (HDAC) inhibitor. Using a mouse model of latent HSV infection, we demonstrate that a targeted endonuclease can be delivered to viral latency sites via an adeno-associated virus (AAV) vector, where it is able to induce mutation of latent HSV genomes. These data provide the first proof-of-principle to our knowledge for the use of a targeted endonuclease as an antiviral agent to treat an established latent viral infection in vivo.

  20. [Celiac disease: an unique autoinmune model].

    Science.gov (United States)

    Rodrigo Sáez, Luis Ricardo

    2008-01-01

    Celiac disease is a unique autoimmune disorder, because the environmental precipitant factor is known. It is gluten, the major storage protein of wheat and similar grains. Originally was considered a rare malabsorption syndrome of childhood, but nowadays is recognized a common condition, that affects to 1% of the general population, all over the world', involves to all different races, may be diagnosed at any age, and affects to many organ systems. Therapy for the disease is a gluten-free-diet that must be strict and long-term. This diet cause a total recovery clinical and analytical, with excellent quality of life of patients.

  1. Application of cross finned tubes in latent heat storages

    Energy Technology Data Exchange (ETDEWEB)

    Schwind, H.; Wolff, D. (Dortmund Univ. (Germany, F.R.). Lehrstuhl fuer Anlagentechnik); Brose, J. (Dortmund Univ. (Germany, F.R.). Arbeitsgruppe Chemieapparatebau)

    1978-01-01

    Heat storages, utilizing the latent heat of materials have in comparison with sensible heat storages the two fundamental advantages of small storage volumes and constant temperatures during charge and discharge. Known storage systems in the field of industrial heating may be replaced advantageous by latent heat storage systems. A new latent heat storage, applying storage material around vertical arranged cross finned tubes is presented. It results in good heat transfer rates and avoids degredation and stratification of salthydrates during operation. The scaling-up of a single cross finned tube to a compact unit with plate fins seems to be practicable without problems. Some experimental results are presented.

  2. Optical Properties of Drug Metabolites in Latent Fingermarks

    CERN Document Server

    Shen, Yao

    2015-01-01

    Drug metabolites usually have structures of split-ring resonators (SRRs), which might lead to negative permittivity and permeability in electromagnetic field. As a result, in the UV-vis region, the latent fingermarks images of drug addicts and non drug users are inverse. The optical properties of latent fingermarks are quite different between drug addicts and non-drug users. This is a technic superiority for crime scene investigation to distinguish them. In this paper, we calculate the permittivity and permeability of drug metabolites using tight-binding model. The latent fingermarks of smokers and non-smokers are given as an example.

  3. Group Lasso with Overlaps: the Latent Group Lasso approach

    CERN Document Server

    Obozinski, Guillaume; Vert, Jean-Philippe

    2011-01-01

    We study a norm for structured sparsity which leads to sparse linear predictors whose supports are unions of prede ned overlapping groups of variables. We call the obtained formulation latent group Lasso, since it is based on applying the usual group Lasso penalty on a set of latent variables. A detailed analysis of the norm and its properties is presented and we characterize conditions under which the set of groups associated with latent variables are correctly identi ed. We motivate and discuss the delicate choice of weights associated to each group, and illustrate this approach on simulated data and on the problem of breast cancer prognosis from gene expression data.

  4. The latent rationality of risky decisions

    Energy Technology Data Exchange (ETDEWEB)

    Japp, K.P. [Bielefeld Univ. (Germany). Faculty for Sociology

    1999-12-01

    . So rationality will stay latent as the operation of re-entry. It may become manifest as legitimating of something else, for instance as rational choice. In everyday life re-entries emerge as compromise. But compromises conceal the relevant difference. In scientific life re-entries emerge as mixed scanning. But mixed scanning displays a mix, not a difference. And it is always a difference which makes a difference. This remains latent.

  5. Latent Herpes Viruses Reactivation in Astronauts

    Science.gov (United States)

    Mehta, Satish K.; Pierson, Duane L.

    2008-01-01

    Space flight has many adverse effects on human physiology. Changes in multiple systems, including the cardiovascular, musculoskeletal, neurovestibular, endocrine, and immune systems have occurred (12, 32, 38, 39). Alterations in drug pharmacokinetics and pharmacodynamics (12), nutritional needs (31), renal stone formation (40), and microbial flora (2) have also been reported. Evidence suggests that the magnitude of some changes may increase with time in space. A variety of changes in immunity have been reported during both short (.16 days) and long (>30 days) space missions. However, it is difficult to determine the medical significance of these immunological changes in astronauts. Astronauts are in excellent health and in superb physical condition. Illnesses in astronauts during space flight are not common, are generally mild, and rarely affect mission objectives. In an attempt to clarify this issue, we identified the latent herpes viruses as medically important indicators of the effects of space flight on immunity. This chapter demonstrates that space flight leads to asymptomatic reactivation of latent herpes viruses, and proposes that this results from marked changes in neuroendocrine function and immunity caused by the inherent stressfullness of human space flight. Astronauts experience uniquely stressful environments during space flight. Potential stressors include confinement in an unfamiliar, crowded environment, isolation, separation from family, anxiety, fear, sleep deprivation, psychosocial issues, physical exertion, noise, variable acceleration forces, increased radiation, and others. Many of these are intermittent and variable in duration and intensity, but variable gravity forces (including transitions from launch acceleration to microgravity and from microgravity to planetary gravity) and variable radiation levels are part of each mission and contribute to a stressful environment that cannot be duplicated on Earth. Radiation outside the Earth

  6. Latent Infections with Plasmodium ovale Malaria

    Science.gov (United States)

    Miller, Max J.; Marcus, David M.; Cameron, Douglas G.

    1965-01-01

    Two cases of Plasmodium ovale malaria acquired in West Africa appeared as primary delayed attacks after one year's continuous residence in Canada. Both patients took full prophylactic doses of chloroquine before, during, and for several weeks after exposure. The inadequacy of the 4-aminoquinolines for protection against latent benign tertian malaria is noted, and the use of primaquine is recommended. Paroxysms occurred in the evening and were accompanied by severe muscle pain, features considered typical of ovale malaria. One patient showed electrocardiographic changes and clinical signs of cardiac malfunction; these disappeared following specific treatment for malaria. In this age of accelerated travel and international movements of people it is important that physicians in temperate regions be aware of the exotic infections of the tropics, as well as of the need for protective measures for travellers to areas where these diseases are endemic. ImagesFig. 1aFig. 1b,1cFig. 3 a-dFig. 3 e-h PMID:14296004

  7. Predicting Component Failures Using Latent Dirichlet Allocation

    Directory of Open Access Journals (Sweden)

    Hailin Liu

    2015-01-01

    Full Text Available Latent Dirichlet Allocation (LDA is a statistical topic model that has been widely used to abstract semantic information from software source code. Failure refers to an observable error in the program behavior. This work investigates whether semantic information and failures recorded in the history can be used to predict component failures. We use LDA to abstract topics from source code and a new metric (topic failure density is proposed by mapping failures to these topics. Exploring the basic information of topics from neighboring versions of a system, we obtain a similarity matrix. Multiply the Topic Failure Density (TFD by the similarity matrix to get the TFD of the next version. The prediction results achieve an average 77.8% agreement with the real failures by considering the top 3 and last 3 components descending ordered by the number of failures. We use the Spearman coefficient to measure the statistical correlation between the actual and estimated failure rate. The validation results range from 0.5342 to 0.8337 which beats the similar method. It suggests that our predictor based on similarity of topics does a fine job of component failure prediction.

  8. Latent learning in zebrafish (Danio rerio).

    Science.gov (United States)

    Gómez-Laplaza, Luis M; Gerlai, Robert

    2010-04-02

    The zebrafish may represent an excellent compromise between system complexity and practical simplicity for behavioral brain research. It may be particularly appropriate for large scale screening studies whose aim is to identify mutants with altered phenotypes or novel compounds with particular efficacy. For example, the zebrafish may have utility in the analysis of the biological mechanisms of learning and memory. Although learning and memory have been extensively studied and hundreds of underlying molecular mechanisms have been identified, this number may represent only the fraction of genes involved in these complex brain functions. Thus large scale mutagenesis screens may have utility. In order for such screens to succeed, appropriate screening paradigms must be developed. The first step in this research is the characterization of learning and memory capabilities of zebrafish and the development of automatable tasks. Here we show that zebrafish is capable of latent learning, i.e. can acquire memory of their environment after being allowed to explore it. For example, we found experimental zebrafish that experienced an open left tunnel or an open right tunnel of a maze during the unrewarded exploration phase of the test to show the appropriate side bias during a probe trial when they had to swim to a group of conspecifics (the reward). Given that exploration of the maze does not require the presence of the experimenter and the probe trial, during which the subjects are video-recorded and their memory is tested, is short, we argue that the paradigm has utility in high-throughput screening.

  9. Effects of fencamfamine on latent inhibition.

    Science.gov (United States)

    Alves, Cilene R R; Delucia, Roberto; Silva, M Teresa A

    2002-10-01

    The effects of fencamfamine (FCF), an indirect dopamine (DA) agent, were investigated using the latent inhibition (LI) model of schizophrenia. In the LI procedure, rats preexposed (PE) to an unreinforced stimulus show difficulty in subsequent learning of an association in which that stimulus is predictive of an unconditioned stimulus (US). FCF (1.75, 3.5 and 7.0 mg/kg i.p.) yielded an inverse dose-response relationship regarding LI. At 3.5 mg/kg, LI was abolished and no effect was observed at 1.75 and 7.0 mg/kg. The effect of FCF (3.5 mg/kg) on LI was blocked by the antipsychotic risperidone (RIS; 4.0 mg/kg), a D2/5HT2 antagonist. These results confirm the similarity of the behavioral profile of FCF and amphetamine (AMPH). In addition, they provide a further validation of the LI model for psychosis, since RIS was shown to prevent a psychostimulant-induced disruption of LI.

  10. Solar Thermoelectricity via Advanced Latent Heat Storage

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Michele L.; Rea, J.; Glatzmaier, Greg C.; Hardin, C.; Oshman, C.; Vaughn, J.; Roark, T.; Raade, J. W.; Bradshaw, R. W.; Sharp, J.; Avery, Azure D.; Bobela, David; Bonner, R.; Weigand, R.; Campo, D.; Parilla, Philip A.; Siegel, N. P.; Toberer, Eric S.; Ginley, David S.

    2016-05-31

    We report on a new modular, dispatchable, and cost-effective solar electricity-generating technology. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) integrates several state-of-the-art technologies to provide electricity on demand. In the envisioned STEALS system, concentrated sunlight is converted to heat at a solar absorber. The heat is then delivered to either a thermoelectric (TE) module for direct electricity generation, or to charge a phase change material for thermal energy storage, enabling subsequent generation during off-sun hours, or both for simultaneous electricity production and energy storage. The key to making STEALS a dispatchable technology lies in the development of a 'thermal valve,' which controls when heat is allowed to flow through the TE module, thus controlling when electricity is generated. The current project addresses each of the three major subcomponents, (i) the TE module, (ii) the thermal energy storage system, and (iii) the thermal valve. The project also includes system-level and techno- economic modeling of the envisioned integrated system and will culminate in the demonstration of a laboratory-scale STEALS prototype capable of generating 3kWe.

  11. Solar thermoelectricity via advanced latent heat storage

    Science.gov (United States)

    Olsen, M. L.; Rea, J.; Glatzmaier, G. C.; Hardin, C.; Oshman, C.; Vaughn, J.; Roark, T.; Raade, J. W.; Bradshaw, R. W.; Sharp, J.; Avery, A. D.; Bobela, D.; Bonner, R.; Weigand, R.; Campo, D.; Parilla, P. A.; Siegel, N. P.; Toberer, E. S.; Ginley, D. S.

    2016-05-01

    We report on a new modular, dispatchable, and cost-effective solar electricity-generating technology. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) integrates several state-of-the-art technologies to provide electricity on demand. In the envisioned STEALS system, concentrated sunlight is converted to heat at a solar absorber. The heat is then delivered to either a thermoelectric (TE) module for direct electricity generation, or to charge a phase change material for thermal energy storage, enabling subsequent generation during off-sun hours, or both for simultaneous electricity production and energy storage. The key to making STEALS a dispatchable technology lies in the development of a "thermal valve," which controls when heat is allowed to flow through the TE module, thus controlling when electricity is generated. The current project addresses each of the three major subcomponents, (i) the TE module, (ii) the thermal energy storage system, and (iii) the thermal valve. The project also includes system-level and techno- economic modeling of the envisioned integrated system and will culminate in the demonstration of a laboratory-scale STEALS prototype capable of generating 3kWe.

  12. Photoacoustic and Colorimetric Visualization of Latent Fingerprints.

    Science.gov (United States)

    Song, Kai; Huang, Peng; Yi, Chenglin; Ning, Bo; Hu, Song; Nie, Liming; Chen, Xiaoyuan; Nie, Zhihong

    2015-12-22

    There is a high demand on a simple, rapid, accurate, user-friendly, cost-effective, and nondestructive universal method for latent fingerprint (LFP) detection. Herein, we describe a combination imaging strategy for LFP visualization with high resolution using poly(styrene-alt-maleic anhydride)-b-polystyrene (PSMA-b-PS) functionalized gold nanoparticles (GNPs). This general approach integrates the merits of both colorimetric imaging and photoacoustic imaging. In comparison with the previous methods, our strategy is single-step and does not require the signal amplification by silver staining. The PSMA-b-PS functionalized GNPs have good stability, tunable color, and high affinity for universal secretions (proteins/polypeptides/amino acids), which makes our approach general and flexible for visualizing LFPs on different substrates (presumably with different colors) and from different people. Moreover, the unique optical property of GNPs enables the photoacoustic imaging of GNPs-deposited LFPs with high resolution. This allows observation of level 3 hyperfine features of LFPs such as the pores and ridge contours by photoacoustic imaging. This technique can potentially be used to identify chemicals within LFP residues. We believe that this dual-modality imaging of LFPs will find widespread use in forensic investigations and medical diagnostics.

  13. Gaussian Process Structural Equation Models with Latent Variables

    CERN Document Server

    Silva, Ricardo

    2010-01-01

    In a variety of disciplines such as social sciences, psychology, medicine and economics, the recorded data are considered to be noisy measurements of latent variables connected by some causal structure. This corresponds to a family of graphical models known as the structural equation model with latent variables. While linear non-Gaussian variants have been well-studied, inference in nonparametric structural equation models is still underdeveloped. We introduce a sparse Gaussian process parameterization that defines a non-linear structure connecting latent variables, unlike common formulations of Gaussian process latent variable models. An efficient Markov chain Monte Carlo procedure is described. We evaluate the stability of the sampling procedure and the predictive ability of the model compared against the current practice.

  14. Effect of Boundary Layer Latent Heating on MJO Simulations

    Institute of Scientific and Technical Information of China (English)

    LING Jian; LI Chongyin; ZHOU Wen; JIA Xiaolong; Chidong ZHANG

    2013-01-01

    A latent heating peak in the PBL was detected in a simulation by a global GCM that failed to reproduce Madden-Julian Oscillation (MJO).The latent heating peak in the PBL was generated by very shallow convection,which prevented moisture from being transported to the free troposphere.Large amount of moisture was therefore confined to the PBL,leading to a dry bias in the free atmosphere.Suffering from this dry bias,deep convection became lethargic,and MJO signals failed to occur.When the latent heating peak in the PBL was removed in another simulation,reasonable MJO signals,including the eastward propagation and the structure of its large-scale circulation,appeared.We therefore propose that the excessive latent heating peak in the PBL due to hyperactive shallow convection may be a reason for a lack of MJO signals in some simulations by other GCMs as well.

  15. A solar air collector with integrated latent heat thermal storage

    Science.gov (United States)

    Charvat, Pavel; Ostry, Milan; Mauder, Tomas; Klimes, Lubomir

    2012-04-01

    Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM) was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data).

  16. A solar air collector with integrated latent heat thermal storage

    Directory of Open Access Journals (Sweden)

    Klimes Lubomir

    2012-04-01

    Full Text Available Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data.

  17. Understanding the sufficiency of information for latent fingerprint value determinations.

    Science.gov (United States)

    Ulery, Bradford T; Hicklin, R Austin; Kiebuzinski, George I; Roberts, Maria Antonia; Buscaglia, Joann

    2013-07-10

    A latent print examiner's assessment of the value, or suitability, of a latent impression is the process of determining whether the impression has sufficient information to make a comparison. A "no value" determination preemptively states that no individualization or exclusion determination could be made using the impression, regardless of quality of the comparison prints. Factors contributing to a value determination include clarity and the types, quantity, and relationships of features. These assessments are made subjectively by individual examiners and may vary among examiners. We modeled the relationships between value determinations and feature annotations made by 21 certified latent print examiners on 1850 latent impressions. Minutia count was strongly associated with value determinations. None of the models resulted in a stronger intraexaminer association with "value for individualization" determinations than minutia count alone. The association between examiner annotation and value determinations is greatly limited by the lack of reproducibility of both annotation and value determinations.

  18. Protection from latent inhibition provided by a conditioned inhibitor.

    Science.gov (United States)

    McConnell, Bridget L; Wheeler, Daniel S; Urcelay, Gonzalo P; Miller, Ralph R

    2009-10-01

    Two conditioned suppression experiments with rats investigated the influence on latent inhibition of compounding a Pavlovian conditioned inhibitor with the target cue during preexposure treatment. Results were compared with those of subjects that received conventional latent inhibition training, no preexposure, or preexposure to the target cue in compound with a neutral stimulus. In Experiment 1, greater attenuation of the latent inhibition effect was observed in subjects that received target preexposure in compound with a Pavlovian conditioned inhibitor relative to subjects that received preexposure with a neutral stimulus or to the target alone. In Experiment 2, this protection from latent inhibition was attenuated if the excitor that was used to train the conditioned inhibitor was extinguished between preexposure and target training. The results are consistent with an account offered by the extended comparator hypothesis.

  19. Motivational control of latent inhibition in flavor preference conditioning.

    Science.gov (United States)

    Garcia-Burgos, David; González, Felisa; Hall, Geoffrey

    2013-09-01

    In three experiments, rats given pairings of a neutral flavor with sucrose showed a preference for that flavor when subsequently allowed to choose between it and water. Preexposure to the flavor produced a latent inhibition effect (reduced the size of the preference) when the rats were hungry during the test (Experiments 1 and 2). Rats that were not hungry during the test failed to show latent inhibition (Experiments 1-3). Experiment 3 confirmed that sucrose-flavor pairings were capable of producing a preference even in nonhungry rats. It is argued that the preference shown by rats that are hungry on test depends on a flavor-nutrient association, a form of learning that is susceptible to latent inhibition in the same way as standard conditioning procedures are. The failure to obtain latent inhibition in nonhungry rats suggests that the preference obtained in these conditions depends on a different form of learning that is less susceptible to the effects of stimulus exposure.

  20. A Non-Gaussian Spatial Generalized Linear Latent Variable Model

    KAUST Repository

    Irincheeva, Irina

    2012-08-03

    We consider a spatial generalized linear latent variable model with and without normality distributional assumption on the latent variables. When the latent variables are assumed to be multivariate normal, we apply a Laplace approximation. To relax the assumption of marginal normality in favor of a mixture of normals, we construct a multivariate density with Gaussian spatial dependence and given multivariate margins. We use the pairwise likelihood to estimate the corresponding spatial generalized linear latent variable model. The properties of the resulting estimators are explored by simulations. In the analysis of an air pollution data set the proposed methodology uncovers weather conditions to be a more important source of variability than air pollution in explaining all the causes of non-accidental mortality excluding accidents. © 2012 International Biometric Society.

  1. Latent-failure risk estimates for computer control

    Science.gov (United States)

    Dunn, William R.; Folsom, Rolfe A.; Green, Owen R.

    1991-01-01

    It is shown that critical computer controls employing unmonitored safety circuits are unsafe. Analysis supporting this result leads to two additional, important conclusions: (1) annual maintenance checks of safety circuit function do not, as widely believed, eliminate latent failure risk; (2) safety risk remains even if multiple, series-connected protection circuits are employed. Finally, it is shown analytically that latent failure risk is eliminated when continuous monitoring is employed.

  2. Time-resolved imaging of latent fingerprints with nanosecond resolution

    Science.gov (United States)

    Seah, L. K.; Dinish, U. S.; Ong, S. K.; Chao, Z. X.; Murukeshan, V. M.

    2004-07-01

    Imaging of latent fingerprints using time-resolved (TR) method offers a broader platform to eliminate the unwanted background emission. In this paper, a novel TR imaging technique is demonstrated and implemented, which facilitates the detection of latent fingerprints with nanosecond resolution. Simulated experiments were carried out with two overlapping fingerprints treated with two fluorescent powders having different lifetimes in nanosecond range. The dependence of the fluorescence emission intensity in nanosecond resolution of TR imaging is also revealed.

  3. LATENT INHIBITION AND PSYCHOMETRICALLY DEFINED SCHIZOTYPY: AN EXPERIMENTAL INVESTIGATION

    OpenAIRE

    Tsakanikos, Elias

    2003-01-01

    The review of the literature suggests that the interpretation of the disruption of latent inhibition within the schizophrenia continuum remains elusive due to a number of methodological and theoretical problems. This thesis adopted a personality-based approach to experimental psychopathology testing alternative interpretations of latent inhibition deficits as a function of psychotic-like features in non-clinical participants. Results from 12 Experiments are discussed in terms of a two-compone...

  4. Fitting Latent Cluster Models for Networks with latentnet

    Directory of Open Access Journals (Sweden)

    Pavel N. Krivitsky

    2007-12-01

    Full Text Available latentnet is a package to fit and evaluate statistical latent position and cluster models for networks. Hoff, Raftery, and Handcock (2002 suggested an approach to modeling networks based on positing the existence of an latent space of characteristics of the actors. Relationships form as a function of distances between these characteristics as well as functions of observed dyadic level covariates. In latentnet social distances are represented in a Euclidean space. It also includes a variant of the extension of the latent position model to allow for clustering of the positions developed in Handcock, Raftery, and Tantrum (2007.The package implements Bayesian inference for the models based on an Markov chain Monte Carlo algorithm. It can also compute maximum likelihood estimates for the latent position model and a two-stage maximum likelihood method for the latent position cluster model. For latent position cluster models, the package provides a Bayesian way of assessing how many groups there are, and thus whether or not there is any clustering (since if the preferred number of groups is 1, there is little evidence for clustering. It also estimates which cluster each actor belongs to. These estimates are probabilistic, and provide the probability of each actor belonging to each cluster. It computes four types of point estimates for the coefficients and positions: maximum likelihood estimate, posterior mean, posterior mode and the estimator which minimizes Kullback-Leibler divergence from the posterior. You can assess the goodness-of-fit of the model via posterior predictive checks. It has a function to simulate networks from a latent position or latent position cluster model.

  5. Latent class instrumental variables: a clinical and biostatistical perspective.

    Science.gov (United States)

    Baker, Stuart G; Kramer, Barnett S; Lindeman, Karen S

    2016-01-15

    In some two-arm randomized trials, some participants receive the treatment assigned to the other arm as a result of technical problems, refusal of a treatment invitation, or a choice of treatment in an encouragement design. In some before-and-after studies, the availability of a new treatment changes from one time period to this next. Under assumptions that are often reasonable, the latent class instrumental variable (IV) method estimates the effect of treatment received in the aforementioned scenarios involving all-or-none compliance and all-or-none availability. Key aspects are four initial latent classes (sometimes called principal strata) based on treatment received if in each randomization group or time period, the exclusion restriction assumption (in which randomization group or time period is an instrumental variable), the monotonicity assumption (which drops an implausible latent class from the analysis), and the estimated effect of receiving treatment in one latent class (sometimes called efficacy, the local average treatment effect, or the complier average causal effect). Since its independent formulations in the biostatistics and econometrics literatures, the latent class IV method (which has no well-established name) has gained increasing popularity. We review the latent class IV method from a clinical and biostatistical perspective, focusing on underlying assumptions, methodological extensions, and applications in our fields of obstetrics and cancer research.

  6. Cultured Vestibular Ganglion Neurons Demonstrate Latent HSV1 Reactivation

    Science.gov (United States)

    Roehm, Pamela C.; Camarena, Vladimir; Nayak, Shruti; Gardner, James B.; Wilson, Angus; Mohr, Ian; Chao, Moses V.

    2013-01-01

    Objectives/Hypothesis Vestibular neuritis is a common cause of both acute and chronic vestibular dysfunction. Multiple pathologies have been hypothesized to be the causative agent of vestibular neuritis; however, whether herpes simplex type I (HSV1) reactivation occurs within the vestibular ganglion has not been demonstrated previously by experimental evidence. We developed an in vitro system to study HSV1 infection of vestibular ganglion neurons (VGNs) using a cell culture model system. Study design basic science study. Results Lytic infection of cultured rat VGNs was observed following low viral multiplicity of infection (MOI). Inclusion of acyclovir suppressed lytic replication and allowed latency to be established. Upon removal of acyclovir, latent infection was confirmed with reverse-transcription polymerase chain reaction and by RNA fluorescent in situ hybridization for the latency-associated transcript (LAT). 29% cells in latently infected cultures were LAT positive. The lytic IPC27 transcript was not detected by reverse-transcription polymerase chain reaction (RT-PCR). Reactivation of HSV1 occurred at a high frequency in latently infected cultures following treatment with trichostatin A (TSA), a histone deactylase inhibitor. Conclusions VGNs can be both lytically and latently infected with HSV1. Furthermore, latently infected VGNs can be induced to reactivate using TSA. This demonstrates that reactivation of latent HSV1 infection in the vestibular ganglion can occur in a cell culture model, and suggests that reactivation of HSV1 infection a plausible etiologic mechanism of vestibular neuritis. PMID:21898423

  7. Comparing the context specificity of extinction and latent inhibition.

    Science.gov (United States)

    Miller, Ralph R; Laborda, Mario A; Polack, Cody W; Miguez, Gonzalo

    2015-12-01

    Exposure to a cue alone either before (i.e., latent inhibition treatment) or after (i.e., extinction) the cue is paired with an unconditioned stimulus results in attenuated conditioned responding to the cue. Here we report two experiments in which potential parallels between the context specificity of the effects of extinction and latent inhibition treatments were directly compared in a lick suppression preparation with rats. The reversed ordering of conditioning and nonreinforcement in extinction and latent inhibition designs allowed us to examine the effect of training order on the context specificity of what is learned given phasic reinforcement and nonreinforcement of a target cue. Experiment 1 revealed that when conditioned-stimulus (CS) conditioning and CS nonreinforcement were administered in the same context, both extinction and latent inhibition treatments had reduced impacts on test performance, relative to excitatory conditioning when testing occurred outside the treatment context. Similarly, Experiment 2 showed that when conditioning was administered in one context and nonreinforcement was administered in a second context, the effects of both extinction and latent inhibition treatments were attenuated when testing occurred in a neutral context, relative to the context in which the CS was nonreinforced. The observed context specificity of extinction and latent inhibition treatments has been previously reported in both cases, but not in a single experiment under otherwise identical conditions. The results of the two experiments convergently suggest that memory of nonreinforcement becomes context dependent after a cue is both reinforced and nonreinforced, independent of the order of training.

  8. Latent viral immune inflammatory response model for chronic multisymptom illness.

    Science.gov (United States)

    Maloney, Sean R; Jensen, Susan; Gil-Rivas, Virginia; Goolkasian, Paula

    2013-03-01

    A latent viral immune inflammatory response (LVIIR) model is presented which integrates factors that contribute to chronic multisymptom illness (CMI) in both the veteran and civilian populations. The LVIIR model for CMI results from an integration of clinical experience with a review of the literature in four distinct areas: (1) studies of idiopathic multisymptom illness in the veteran population including two decades of research on Gulf War I veterans with CMI, (2) new evidence supporting the existence of chronic inflammatory responses to latent viral antigens and the effect these responses may have on the nervous system, (3) recent discoveries concerning the role of vitamin D in maintaining normal innate and adaptive immunity including suppression of latent viruses and regulation of the immune inflammatory response, and (4) the detrimental effects of extreme chronic repetitive stress (ECRS) on the immune and nervous systems. The LVIIR model describes the pathophysiology of a pathway to CMI and presents a new direction for the clinical assessment of CMI that includes the use of neurological signs from a physical exam, objective laboratory data, and a new proposed latent viral antigen-antibody imaging technique for the peripheral and central nervous system. The LVIIR model predicts that CMI can be treated by a focus on reversal of immune system impairment, suppression of latent viruses and their antigens, and healing of nervous system tissue damaged by chronic inflammation associated with latent viral antigens and by ECRS. In addition, the LVIIR model suggests that maintaining optimal serum 25 OH vitamin D levels will maximize immune system suppression of latent viruses and their antigens and will minimize immune system inflammation. This model also emphasizes the importance of decreasing ECRS to improve immune system function and to minimize nervous system injury from excess serum glucocorticoid levels. The proposed model supports growing evidence that increasing

  9. Latent Virus Reactivation: From Space to Earth

    Science.gov (United States)

    Mehta, Satish K.; Cohrs, Randall J.; Gilden, Donald H.; Tyring, Stephen K.; Castro, Victoria A.; Ott, C. Mark; Pierson, Duane L.

    2010-01-01

    Reactivation of latent viruses is a recognized consequence of decreased immunity. More recently viral reactivation has been identified as an important in vivo indicator of clinically relevant immune changes. Viral reactivation can be determined quickly and easily by the presence of virus in saliva and other body fluids. Real-time polymerase chain reaction (PCR) is a highly sensitive and specific molecular method to detect the presence of specific viral DNA. Studies in astronauts demonstrated that herpes simplex virus type 1(HSV-1), Epstein-Barr Virus (EBV), cytomegalovirus (CMV), and varicella zoster virus (VZV) reactivate at rates above normal during and after spaceflight in response to moderately decreased T-cell immunity. This technology was expanded to patients on Earth beginning with human immune deficiency virus (HIV) immuno-compromised patients. The HIV patients shed EBV in saliva at rates 9-fold higher than observed in astronauts demonstrating that the level of EBV shedding reflects the severity of impaired immunity. Whereas EBV reactivation is not expected to produce serious effects in astronauts on missions of 6 months or less, VZV reactivation in astronauts could produce shingles. Reactivation of live, infectious VZV in astronauts with no symptoms was demonstrated in astronauts during and after spaceflight. We applied our technology to study VZV-induced shingles in patients. In a study of 54 shingles patients, we showed salivary VZV was present in every patient on the day antiviral (acyclovir) treatment was initiated. Pain and skin lesions decreased with antiviral treatment. Corresponding decreases in levels of VZV were also observed and accompanied recovery. Although the level of VZV in shingles patients before the treatment was generally higher than those found in astronauts, lower range of VZV numbers in shingles patients overlapped with astronaut s levels. This suggests a potential risk of shingles to astronauts resulting from reactivation of VZV. In

  10. A Magnetically Responsive Polydiacetylene Precursor for Latent Fingerprint Analysis.

    Science.gov (United States)

    Lee, Joosub; Lee, Chan Woo; Kim, Jong-Man

    2016-03-01

    A magnetically responsive diacetylene (DA) powder was developed for the visualization of latent fingerprints. A mixture of the DA and magnetite nanoparticles, applied to a surface containing latent fingermarks, becomes immobilized along the ridge patterns of the fingerprints when a magnetic field is applied. Alignment along the ridge structures is a consequence of favorable hydrophobic interactions occurring between the long alkyl chains in the DAs and the lipid-rich, sebaceous latent fingermarks. UV irradiation of the DA-magnetite composite immobilized on the latent fingerprint results in the generation of blue-colored PDAs. Heat treatment of the blue-colored image promotes a blue-to-red transition as well as fluorescence turn-on. A combination of the aligned pale brown-colored monomeric state, UV irradiation generated blue-colored PDA state, as well as the heat treatment generated red-colored and fluorescent PDA state enables efficient visual imaging of a latent fingerprint, which is deposited on various colored solid surfaces.

  11. Latent lip print development and its role in suspect identification

    Directory of Open Access Journals (Sweden)

    Nidhi Dwivedi

    2013-01-01

    Full Text Available Aims and Objective: The study aims to develop latent lip prints on glass surface using fingerprint black powder and its comparison with standard lipstick prints and also determines the effectiveness of the technique. Materials and Methods: This study included a total of 100 subjects, comprising of 50 males and 50 females with age ranging from 17 to 38 years. Latent lipprint was developed by pressing the lips against a glass slab with lips together and the print formed was developed by sprinkling the black finger print powder and transferred to a bond sheet. Subsequently, standard lipstick print was developed from the same subject. All the samples were coded and graded according to the patterns suggested in the literature. Results: Out of 100 latent prints only 29 prints showed lip patterns in all four quadrants. The percentage matching with self lipstick print of good latent prints ranged from 25% to 100% and those of random prints ranged from 8% to 92%. Quadrant wise matching ranged from 52.67% to 57.67%. Statistically significant difference was observed between males and females. Conclusion: The study demonstrates the usefulness of latent lip print in personal identification.

  12. Learning From Hidden Traits: Joint Factor Analysis and Latent Clustering

    Science.gov (United States)

    Yang, Bo; Fu, Xiao; Sidiropoulos, Nicholas D.

    2017-01-01

    Dimensionality reduction techniques play an essential role in data analytics, signal processing and machine learning. Dimensionality reduction is usually performed in a preprocessing stage that is separate from subsequent data analysis, such as clustering or classification. Finding reduced-dimension representations that are well-suited for the intended task is more appealing. This paper proposes a joint factor analysis and latent clustering framework, which aims at learning cluster-aware low-dimensional representations of matrix and tensor data. The proposed approach leverages matrix and tensor factorization models that produce essentially unique latent representations of the data to unravel latent cluster structure -- which is otherwise obscured because of the freedom to apply an oblique transformation in latent space. At the same time, latent cluster structure is used as prior information to enhance the performance of factorization. Specific contributions include several custom-built problem formulations, corresponding algorithms, and discussion of associated convergence properties. Besides extensive simulations, real-world datasets such as Reuters document data and MNIST image data are also employed to showcase the effectiveness of the proposed approaches.

  13. Regression of latent endometrial precancers by progestin infiltrated intrauterine device.

    Science.gov (United States)

    Ørbo, Anne; Rise, Cecil E; Mutter, George L

    2006-06-01

    PTEN tumor suppressor inactivation is the earliest step in endometrial carcinogenesis, occurring in morphologically unremarkable endometrial glands in half of normal women. We test the hypothesis that sex hormones positively or negatively select for these "latent precancers" by examining their emergence, persistence, and regression rates under differing hormonal conditions. Perimenopausal and postmenopausal women had an intake endometrial biopsy and underwent hormonal therapy with progestin-impregnated intrauterine device (IUD; n = 21), cyclic oral progestins (n = 28), or surveillance only (n = 22) with follow-up biopsies. For comparison, premenopausal naturally cycling endometrial biopsies were studied as single time points in 87 patients and multiple surveillance time points in 34 patients. Biopsies in which any PTEN protein-null glands were found by immunohistochemistry were scored as containing a latent endometrial precancer. All groups had a similar proportion of latent precancers at intake but differed after therapy. Emergence rates were highest (21%) for the naturally cycling premenopausal group compared with just 9% for untreated perimenopausal women. The IUD group had the highest rate of regression, with a 62% pretherapy and 5% post-therapy rate of latent precancers. This contrasted to nonsignificant changes for the oral progestin and untreated control groups. Delivery of high doses of progestins locally to the endometrium by IUD leads to ablation of preexisting PTEN-inactivated endometrial latent precancers and is a possible mechanism for reduction of long-term endometrial cancer risk known to occur in response to this hormone.

  14. Some properties of active and latent catechol oxidase of mushroom

    Directory of Open Access Journals (Sweden)

    Janusz Czapski

    2013-12-01

    Full Text Available Latent form of mushroom catechol oxidase was activated by O,1% sodium dodecyl sulfate (SDS. Catalytic power of the latent form, calculated from the kinetic parameters was 1,8 times higher than that of active one. Salicyl hydroxamic acid (SHAM appeared as a powerful inhibitor for both active and latent forms of catechol oxidase. However, in the range of 150-250 μM SHAM the inhibitory effect for active catechol oxidase was significantly higher than that for the latent one. Non-competitive and irreversible characteristics of inhibition of latent and active catechol oxidase was calculated from kinetic data. Electrophoretic analysis followed by scanning of the gels was used. The spots' absorbance was determined from a computer image of the isoenzyme band patterns. It allowed us to estimate gels quantitatively. Presence of one additional clearly defined slow moving isoform of SDS-activated catechol oxidase, differed in the respect of 3 bands for the active and 4 bands for the total.

  15. Enfermedad celíaca del adulto: aspectos endocrinológicos y nutricionales Adult celiac disease: endocrinological and nutritional issues

    Directory of Open Access Journals (Sweden)

    D. Peteiro-González

    2010-10-01

    Full Text Available La enfermedad celíaca es una enteropatía autoinmune que aparece como respuesta a la ingesta de gluten en sujetos genéticamente predispuestos. Aunque históricamente se la ha considerado una patología pediátrica e infrecuente su prevalencia está próxima al 1% de la población general, siendo todavía más elevada en pacientes con determinadas patologías endocrinológicas y déficits nutricionales. El empleo de los anticuerpos antitransglutaminasa y antiendomisio y la endoscopia digestiva con toma de biopsia serán elementos clave para su diagnóstico. La instauración de una dieta sin gluten logrará la recuperación del trofismo intestinal y evitará el riesgo de complicaciones a largo plazo a la vez que mejora la calidad de vida del paciente. El seguimiento médico y nutricional será clave para lograr una buena adherencia terapéutica.Celiac disease is an autoinmune enterophaty induced by the ingestion of gluten in genetically susceptible individuals. Although historically it was thought that it was an infrequent pediatric disease, now it is know that its prevalence is close to 1% in the general population. It is even higher between patients with some endocrine disorders and nutritional deficits. The use of antitransglutaminase and antiendomisium antibodies and the endoscopical duodenal biopsy are the cornerstones for its diagnosis. The introduction of a gluten-free diet will achieve the normalization of the intestinal mucosa. It will avoid the risk of long term complications and an it will achieve an improvement in quality of life. Medical and dietitian long term follow-up will be important to improve the compliance to the treatment.

  16. Use of fluorescence lifetime imaging (FLIM) for latent fingerprints detection

    Science.gov (United States)

    Wang, Peng; Chao, Zhi Xia; Seah, Leong K.; Murukeshan, Vadakke M.

    2005-04-01

    Fluorescence lifetime imaging (FLIM) in frequency domain enables the mapping of the spatial distribution of fluorescence lifetimes of a specimen. FLIM can provide unique information about fluorophores and hence is widely used in biology and for medical diagnostics. In this paper, a theoretical analysis for the fluorescence lifetime determination of latent fingerprint samples is described, which is followed by the feasibility study of using FLIM in frequency domain for latent fingerprints detection. Experiments are carried out with fingerprint on green paper substrate and postcard substrate treated with certain fluorescent powder. The total phase lag and demodulation factor are calculated to determine the lifetimes pixel by pixel. The resulting fluorescence lifetime image of fingerprint revealed an improvement in the contrast, and was able to detect the latent fingerprint clearly.

  17. Latent Fundamentals Arbitrage with a Mixed Effects Factor Model

    Directory of Open Access Journals (Sweden)

    Andrei Salem Gonçalves

    2012-09-01

    Full Text Available We propose a single-factor mixed effects panel data model to create an arbitrage portfolio that identifies differences in firm-level latent fundamentals. Furthermore, we show that even though the characteristics that affect returns are unknown variables, it is possible to identify the strength of the combination of these latent fundamentals for each stock by following a simple approach using historical data. As a result, a trading strategy that bought the stocks with the best fundamentals (strong fundamentals portfolio and sold the stocks with the worst ones (weak fundamentals portfolio realized significant risk-adjusted returns in the U.S. market for the period between July 1986 and June 2008. To ensure robustness, we performed sub period and seasonal analyses and adjusted for trading costs and we found further empirical evidence that using a simple investment rule, that identified these latent fundamentals from the structure of past returns, can lead to profit.

  18. Classification criteria of syndromes by latent variable models

    DEFF Research Database (Denmark)

    Petersen, Janne

    2010-01-01

    The thesis has two parts; one clinical part: studying the dimensions of human immunodeficiency virus associated lipodystrophy syndrome (HALS) by latent class models, and a more statistical part: investigating how to predict scores of latent variables so these can be used in subsequent regression...... analyses. Part 1: HALS engages different phenotypic changes of peripheral lipoatrophy and central lipohypertrophy.  There are several different definitions of HALS and no consensus on the number of phenotypes. Many of the definitions consist of counting fulfilled criteria on markers and do not include...... patient's characteristics. These methods may erroneously reduce multiplicity either by combining markers of different phenotypes or by mixing HALS with other processes such as aging. Latent class models identify homogenous groups of patients based on sets of variables, for example symptoms. As no gold...

  19. Current management options for latent tuberculosis: a review

    Directory of Open Access Journals (Sweden)

    Norton BL

    2012-11-01

    Full Text Available Brianna L Norton, David P HollandDepartment of Medicine, Division of Infectious Diseases, Duke University Medical Center, Durham, NC, USAAbstract: Tuberculosis remains the world’s second leading infectious cause of death, with nearly one-third of the global population latently infected. Treatment of latent tuberculosis infection is a mainstay of tuberculosis-control efforts in low-to medium-incidence countries. Isoniazid monotherapy has been the standard of care for decades, but its utility is impaired by poor completion rates. However, new, shorter-course regimens using rifamycins improve completion rates and are cost-saving compared with standard isoniazid monotherapy. We review the currently available therapies for latent tuberculosis infection and their toxicities and include a brief economic comparison of the different regimens.Keywords: isoniazid, rifampin, rifapentine, tuberculin skin test, interferon-gamma release assay

  20. Cosine Based Latent Factor Model for Precision Oriented Recommendation

    Directory of Open Access Journals (Sweden)

    Bipul Kumar

    2016-01-01

    Full Text Available Recommender systems suggest a list of interesting items to users based on their prior purchase or browsing behaviour on e-commerce platforms. The continuing research in recommender systems have primarily focused on developing algorithms for rating prediction task. However, most e-commerce platforms provide ‘top-k’ list of interesting items for every user. In line with this idea, the paper proposes a novel machine learning algorithm to predict a list of ‘top-k’ items by optimizing the latent factors of users and items with the mapped scores from ratings. The basic idea is to learn latent factors based on the cosine similarity between the users and items latent features which is then used to predict the scores for unseen items for every user. Comprehensive empirical evaluations on publicly available benchmark datasets reveal that the proposed model outperforms the state-of-the-art algorithms in recommending good items to a user.

  1. Latent Tuberculosis in Pregnancy: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Isabelle Malhamé

    Full Text Available In countries with low tuberculosis (TB incidence, immigrants from higher incidence countries represent the major pool of individuals with latent TB infection (LTBI. The antenatal period represents an opportunity for immigrant women to access the medical system, and hence for potential screening and treatment of LTBI. However, such screening and treatment during pregnancy remains controversial.In order to further understand the prevalence, natural history, screening and management of LTBI in pregnancy, we conducted a systematic literature review addressing the screening and treatment of LTBI, in pregnant women without known HIV infection.A systematic review of 4 databases (Embase, Embase Classic, Medline, Cochrane Library covering articles published from January 1st 1980 to April 30th 2014. Articles in English, French or Spanish with relevant information on prevalence, natural history, screening tools, screening strategies and treatment of LTBI during pregnancy were eligible for inclusion. Articles were excluded if (1 Full text was not available (2 they were case series or case studies (3 they focused exclusively on prevalence, diagnosis and treatment of active TB (4 the study population was exclusively HIV-infected.Of 4,193 titles initially identified, 208 abstracts were eligible for review. Of these, 30 articles qualified for full text review and 22 were retained: 3 cohort studies, 2 case-control studies, and 17 cross-sectional studies. In the USA, the estimated prevalence of LTBI ranged from 14 to 48% in women tested, and tuberculin skin test (TST positivity was associated with ethnicity. One study suggested that incidence of active TB was significantly increased during the 180 days postpartum (Incidence rate ratio, 1.95 (95% CI 1.24-3.07. There was a high level of adherence with both skin testing (between 90-100% and chest radiography (93-100%.. In three studies from low incidence settings, concordance between TST and an interferon

  2. Treatment guidelines for latent tuberculosis infection.

    Science.gov (United States)

    2014-01-01

    The treatment of latent tuberculosis infection (LTBI) has been established as valid for patients at high risk for developing active tuberculosis. Treatment of LTBI is also considered an important strategy for eliminating tuberculosis (TB) in Japan. In recent years, interferon-gamma release assays have come into widespread use; isoniazid (INH) preventive therapy for HIV patients has come to be recommended worldwide; and there have been increases in both types of biologics used in the treatment of immune diseases as well as the diseases susceptible to treatment. In light of the above facts, the Prevention Committee and the Treatment Committee of the Japanese Society for Tuberculosis have jointly drafted these guidelines. In determining subjects for LTBI treatment, the following must be considered: 1) risk of TB infection/ development; 2) infection diagnosis; 3) chest image diagnosis; 4) the impact of TB development; 5) the possible manifestation of side effects; and 6) the prospects of treatment completion. LTBI treatment is actively considered when relative risk is deemed 4 or higher, including risk factors such as the following: HIV/AIDS, organ transplants (immunosuppressant use), silicosis, dialysis due to chronic renal failure, recent TB infection (within 2 years), fibronodular shadows in chest radiographs (untreated old TB), the use of biologics, and large doses of corticosteroids. Although the risk is lower, the following risk factors require consideration of LTBI treatment when 2 or more of them are present: use of oral or inhaled corticosteroids, use of other immunosuppressants, diabetes, being underweight, smoking, gastrectomy, and so on. In principle, INH is administered for a period of 6 or 9 months. When INH cannot be used, rifampicin is administered for a period of 4 or 6 months. It is believed that there are no reasons to support long-term LTBI treatment for immunosuppressed patients in Japan, where the risk of infection is not considered markedly high

  3. Design and simulation of latent heat storage units. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Shamsundar, N.; Stein, E.; Rooz, E.; Bascaran, E.; Lee, T.C. [Houston Univ., TX (United States)

    1992-04-01

    This report presents the results of two years of research and development on passive latent heat storage systems. Analytical models have been developed and extended, and a computer code for simulating the performance of a latent heat storage has been developed. The code is intended to be merged into a larger solar energy system simulation code and used for making realistic system studies. Simulation studies using a code which has a flexible and accurate routine for handling the storage subsystem should lead to the development of better systems than those in which storage is added on after the rest of the system has already been selected and optimized.

  4. Design and simulation of latent heat storage units

    Energy Technology Data Exchange (ETDEWEB)

    Shamsundar, N.; Stein, E.; Rooz, E.; Bascaran, E.; Lee, T.C. (Houston Univ., TX (United States))

    1992-04-01

    This report presents the results of two years of research and development on passive latent heat storage systems. Analytical models have been developed and extended, and a computer code for simulating the performance of a latent heat storage has been developed. The code is intended to be merged into a larger solar energy system simulation code and used for making realistic system studies. Simulation studies using a code which has a flexible and accurate routine for handling the storage subsystem should lead to the development of better systems than those in which storage is added on after the rest of the system has already been selected and optimized.

  5. Chromatin Structure of Epstein-Barr Virus Latent Episomes.

    Science.gov (United States)

    Lieberman, Paul M

    2015-01-01

    EBV latent infection is characterized by a highly restricted pattern of viral gene expression. EBV can establish latent infections in multiple different tissue types with remarkable variation and plasticity in viral transcription and replication. During latency, the viral genome persists as a multi-copy episome, a non-integrated-closed circular DNA with nucleosome structure similar to cellular chromosomes. Chromatin assembly and histone modifications contribute to the regulation of viral gene expression, DNA replication, and episome persistence during latency. This review focuses on how EBV latency is regulated by chromatin and its associated processes.

  6. Powder method for detecting latent fingerprints: a review.

    Science.gov (United States)

    Sodhi, G S; Kaur, J

    2001-09-01

    The powder technique for detecting latent fingerprints involves the application of a finely divided formulation to the fingermark impression, generally with a glass-fibre or a camel hair brush. The powder gets mechanically adhered to the sweat residue defining the ridge pattern. The furrows which are devoid of the fingerprint residue, do not adhere the powder onto them. The final outcome is that the powder formulation sticks to the ridges, but is easily blown off the furrows. Since the powder is normally coloured, the ridge pattern becomes visible and the latent print is said to have developed.

  7. Latent common manifold learning with alternating diffusion: analysis and applications

    CERN Document Server

    Talmon, Ronen

    2016-01-01

    The analysis of data sets arising from multiple sensors has drawn significant research attention over the years. Traditional methods, including kernel-based methods, are typically incapable of capturing nonlinear geometric structures. We introduce a latent common manifold model underlying multiple sensor observations for the purpose of multimodal data fusion. A method based on alternating diffusion is presented and analyzed; we provide theoretical analysis of the method under the latent common manifold model. To exemplify the power of the proposed framework, experimental results in several applications are reported.

  8. Hippocampus NMDA receptors selectively mediate latent extinction of place learning.

    Science.gov (United States)

    Goodman, Jarid; Gabriele, Amanda; Packard, Mark G

    2016-09-01

    Extinction of maze learning may be achieved with or without the animal performing the previously acquired response. In typical "response extinction," animals are given the opportunity to make the previously acquired approach response toward the goal location of the maze without reinforcement. In "latent extinction," animals are not given the opportunity to make the previously acquired response and instead are confined to the previous goal location without reinforcement. Previous evidence indicates that the effectiveness of these protocols may depend on the type of memory being extinguished. Thus, one aim of the present study was to further examine the effectiveness of response and latent extinction protocols across dorsolateral striatum (DLS)-dependent response learning and hippocampus-dependent place learning tasks. In addition, previous neural inactivation experiments indicate a selective role for the hippocampus in latent extinction, but have not investigated the precise neurotransmitter mechanisms involved. Thus, the present study also examined whether latent extinction of place learning might depend on NMDA receptor activity in the hippocampus. In experiment 1, adult male Long-Evans rats were trained in a response learning task in a water plus-maze, in which animals were reinforced to make a consistent body-turn response to reach an invisible escape platform. Results indicated that response extinction, but not latent extinction, was effective at extinguishing memory in the response learning task. In experiment 2, rats were trained in a place learning task, in which animals were reinforced to approach a consistent spatial location containing the hidden escape platform. In experiment 2, animals also received intra-hippocampal infusions of the NMDA receptor antagonist 2-amino-5-phosphopentanoic acid (AP5; 5.0 or 7.5 ug/0.5 µg) or saline vehicle immediately before response or latent extinction training. Results indicated that both extinction protocols were

  9. Incorporación de materiales de cambio de fase en placas de yeso para almacenamiento de energía térmica mediante calor latente: caracterización térmica del material mediante la técnica DSC

    Directory of Open Access Journals (Sweden)

    Oliver, A.

    2011-06-01

    Full Text Available Differential Scanning Calorimetry (DSC is a thermal analysis technique which has been used for more than three decades to measure the temperatures and heat flows associated with transitions in materials as a function of time. Other techniques, are Differential Thermal Analysis DTA and Conventional Calorimetry. There is great uncertainty in the values supplied by the manufacturers (because they are referred to pure substances and the DSC should be used to get more accurate values. It will be analyzed the thermal storage capacity depending on temperature for several compound materials formed by some aggregates, mainly gypsum and phase change materials, in various proportions. The results have been compared with other building materials such as gypsum boards and brick layer. The suitability of the new construction material for thermal energy storage will be assessed in comparison with other materials traditionally used for this purpose.

    La Calorimetría Diferencial de Barrido es una técnica de análisis térmico, usada desde hace décadas, para medir la entalpía asociada al cambio de fase de un material como función del tiempo y de la temperatura. Otras técnicas menos utilizadas son la Calorimetría Convencional el Análisis Térmico Diferencial. Existe una gran incertidumbre en los valores de propiedades suministrados por los fabricantes (puesto que éstos se refieren a las sustancias puras y es conveniente utilizar DSC para tener valores más exactos. Se va a analizar la capacidad de almacenamiento térmico en función de la temperatura de varios materiales compuestos formados por los mismos agregados -principalmente yeso y material de cambio de fase- en distintas proporciones. Los valores obtenidos se comparan con otros materiales constructivos, yeso laminado y ladrillo. También se verifica la idoneidad del nuevo material constructivo para el almacenamiento de energía térmica frente a otros materiales utilizados

  10. Asymptotic accuracy of Bayesian estimation for a single latent variable.

    Science.gov (United States)

    Yamazaki, Keisuke

    2015-09-01

    In data science and machine learning, hierarchical parametric models, such as mixture models, are often used. They contain two kinds of variables: observable variables, which represent the parts of the data that can be directly measured, and latent variables, which represent the underlying processes that generate the data. Although there has been an increase in research on the estimation accuracy for observable variables, the theoretical analysis of estimating latent variables has not been thoroughly investigated. In a previous study, we determined the accuracy of a Bayes estimation for the joint probability of the latent variables in a dataset, and we proved that the Bayes method is asymptotically more accurate than the maximum-likelihood method. However, the accuracy of the Bayes estimation for a single latent variable remains unknown. In the present paper, we derive the asymptotic expansions of the error functions, which are defined by the Kullback-Leibler divergence, for two types of single-variable estimations when the statistical regularity is satisfied. Our results indicate that the accuracies of the Bayes and maximum-likelihood methods are asymptotically equivalent and clarify that the Bayes method is only advantageous for multivariable estimations.

  11. Immune parameters differentiating active from latent tuberculosis infection in humans.

    Science.gov (United States)

    Lee, Ji Yeon; Jung, Young Won; Jeong, Ina; Joh, Joon-Sung; Sim, Soo Yeon; Choi, Boram; Jee, Hyeon-Gun; Lim, Dong-Gyun

    2015-12-01

    Tuberculosis remains a highly prevalent infectious disease worldwide. Identification of the immune parameters that differentiate active disease from latent infection will facilitate the development of efficient control measures as well as new diagnostic modalities for tuberculosis. Here, we investigated the cytokine production profiles of monocytes and CD4(+) T lymphocytes upon encountering mycobacterial antigens. In addition, cytokines and lipid mediators with immune-modulating activities were examined in plasma samples ex vivo. Comparison of these parameters in active tuberculosis patients and healthy subjects with latent infection revealed that, active tuberculosis was associated with diminished Th1-type cytokine secretion from CD4(+) T cells and less augmented inflammatory cytokine secretion from monocytes induced by IFN-γ than that in latent tuberculosis infection. In addition, a higher plasma concentration of lipoxin A4 and lower ratio of prostaglandin E2 to lipoxin A4 were observed in active cases than in latent infections. These findings have implications for preparing new therapeutic strategies and for differential diagnosis of the two types of tuberculosis infection.

  12. Bayesian latent factor regression for functional and longitudinal data.

    Science.gov (United States)

    Montagna, Silvia; Tokdar, Surya T; Neelon, Brian; Dunson, David B

    2012-12-01

    In studies involving functional data, it is commonly of interest to model the impact of predictors on the distribution of the curves, allowing flexible effects on not only the mean curve but also the distribution about the mean. Characterizing the curve for each subject as a linear combination of a high-dimensional set of potential basis functions, we place a sparse latent factor regression model on the basis coefficients. We induce basis selection by choosing a shrinkage prior that allows many of the loadings to be close to zero. The number of latent factors is treated as unknown through a highly-efficient, adaptive-blocked Gibbs sampler. Predictors are included on the latent variables level, while allowing different predictors to impact different latent factors. This model induces a framework for functional response regression in which the distribution of the curves is allowed to change flexibly with predictors. The performance is assessed through simulation studies and the methods are applied to data on blood pressure trajectories during pregnancy.

  13. Removing systematic errors for exoplanet search via latent causes

    CERN Document Server

    Schölkopf, Bernhard; Wang, Dun; Foreman-Mackey, Daniel; Janzing, Dominik; Simon-Gabriel, Carl-Johann; Peters, Jonas

    2015-01-01

    We describe a method for removing the effect of confounders in order to reconstruct a latent quantity of interest. The method, referred to as half-sibling regression, is inspired by recent work in causal inference using additive noise models. We provide a theoretical justification and illustrate the potential of the method in a challenging astronomy application.

  14. Evaluation of AFIS-Ranked latent fingerprint matched templates

    NARCIS (Netherlands)

    Krish, Ram P.; Fierrez, Julian; Ramos, Daniel; Veldhuis, Raymond; Wang, Ruifang; Klette, Reinhard; Rivera, Mariano; Satoh, Shin'ichi

    2013-01-01

    The methodology currently practiced in latent print examination (known as ACE-V) yields only a decision as result, namely individualization, exclusion or inconclusive. From such a decision, it is not possible to express the strength of opinion of a forensic examiner quantitatively with a scientific

  15. A Taxometric Exploration of the Latent Structure of Hoarding

    Science.gov (United States)

    Timpano, Kiara R.; Broman-Fulks, Joshua J.; Glaesmer, Heide; Exner, Cornelia; Rief, Winfried; Olatunji, Bunmi O.; Keough, Meghan E.; Riccardi, Christina J.; Brahler, Elmar; Wilhelm, Sabine; Schmidt, Norman B.

    2013-01-01

    Despite controversy regarding the classification and diagnostic status of hoarding disorder, there remains a paucity of research on the nosology of hoarding that is likely to inform the classification debate. The present investigation examined the latent structure of hoarding in three, large independent samples. Data for three well-validated…

  16. Identifying subgroups of patients using latent class analysis

    DEFF Research Database (Denmark)

    Nielsen, Anne Mølgaard; Kent, Peter; Hestbæk, Lise

    2017-01-01

    BACKGROUND: Heterogeneity in patients with low back pain (LBP) is well recognised and different approaches to subgrouping have been proposed. Latent Class Analysis (LCA) is a statistical technique that is increasingly being used to identify subgroups based on patient characteristics. However, as ...

  17. Temporal analysis of text data using latent variable models

    DEFF Research Database (Denmark)

    Mølgaard, Lasse Lohilahti; Larsen, Jan; Goutte, Cyril

    2009-01-01

    Detecting and tracking of temporal data is an important task in multiple applications. In this paper we study temporal text mining methods for Music Information Retrieval. We compare two ways of detecting the temporal latent semantics of a corpus extracted from Wikipedia, using a stepwise...

  18. Complete genome sequence of the alfalfa latent virus

    Science.gov (United States)

    Alfalfa latent virus (ALV) is a member of the carlavirus group and occurs symptomlessly in alfalfa (Medicago sativa). In the US it is prevalent in Nebraska and Wisconsin. The virus is recognized as a strain of Pea streak virus (PeSV) So far, no complete genomic sequence of PSV or ALV is availab...

  19. Latent cluster analysis of ALS phenotypes identifies prognostically differing groups.

    Directory of Open Access Journals (Sweden)

    Jeban Ganesalingam

    Full Text Available BACKGROUND: Amyotrophic lateral sclerosis (ALS is a degenerative disease predominantly affecting motor neurons and manifesting as several different phenotypes. Whether these phenotypes correspond to different underlying disease processes is unknown. We used latent cluster analysis to identify groupings of clinical variables in an objective and unbiased way to improve phenotyping for clinical and research purposes. METHODS: Latent class cluster analysis was applied to a large database consisting of 1467 records of people with ALS, using discrete variables which can be readily determined at the first clinic appointment. The model was tested for clinical relevance by survival analysis of the phenotypic groupings using the Kaplan-Meier method. RESULTS: The best model generated five distinct phenotypic classes that strongly predicted survival (p<0.0001. Eight variables were used for the latent class analysis, but a good estimate of the classification could be obtained using just two variables: site of first symptoms (bulbar or limb and time from symptom onset to diagnosis (p<0.00001. CONCLUSION: The five phenotypic classes identified using latent cluster analysis can predict prognosis. They could be used to stratify patients recruited into clinical trials and generating more homogeneous disease groups for genetic, proteomic and risk factor research.

  20. Censored latent effects autoregression, with an application to US unemployment

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)

    1998-01-01

    textabstractA new time series model is proposed to describe observed asymmetries in postwar unemployment data. We assume that recession periods, when unemployment increases rapidly, are caused by unobserved positive shocks. The generating mechanism of these latent shocks is a censored regression mod

  1. Blueberry latent virus: An Amalgam of the Totiviridae and Partitiviridae

    Science.gov (United States)

    A new, symptomless virus was identified in blueberry. The dsRNA genome of the virus, provisionally named Blueberry latent virus (BBLV), codes for two putative proteins and lacks a movement protein, a property only shared with cryptic viruses. More than 35 isolates of the virus from different cultiv...

  2. Treatment: Latent TB Infection (LTBI) and TB Disease

    Science.gov (United States)

    ... the Facts Tuberculosis - The Connection between TB and HIV 12-Dose Regimen for Latent TB Infection-Patient Education Brochure Posters Mantoux Tuberculin Skin Test Wall Chart World TB Day Think TB Stop TB Reports & Articles Morbidity and Mortality Weekly Reports (MMWRs) DTBE Authored ...

  3. Improving Measurement Precision of Hierarchical Latent Traits Using Adaptive Testing

    Science.gov (United States)

    Wang, Chun

    2014-01-01

    Many latent traits in social sciences display a hierarchical structure, such as intelligence, cognitive ability, or personality. Usually a second-order factor is linearly related to a group of first-order factors (also called domain abilities in cognitive ability measures), and the first-order factors directly govern the actual item responses.…

  4. An Alternative Approach for Nonlinear Latent Variable Models

    Science.gov (United States)

    Mooijaart, Ab; Bentler, Peter M.

    2010-01-01

    In the last decades there has been an increasing interest in nonlinear latent variable models. Since the seminal paper of Kenny and Judd, several methods have been proposed for dealing with these kinds of models. This article introduces an alternative approach. The methodology involves fitting some third-order moments in addition to the means and…

  5. Exploring Different Types of Academic Delayers: A Latent Profile Analysis

    Science.gov (United States)

    Grunschel, Carola; Patrzek, Justine; Fries, Stefan

    2013-01-01

    In this study, we explored whether there are different types of academic delayers (i.e., types of students who delay academic tasks). Latent profile analysis based on 554 university students' reasons for academic delay revealed four distinct types: inconspicuous, successful pressure-seeking, worried/anxious, and discontent with studies. The types…

  6. Mediation Analysis in a Latent Growth Curve Modeling Framework

    Science.gov (United States)

    von Soest, Tilmann; Hagtvet, Knut A.

    2011-01-01

    This article presents several longitudinal mediation models in the framework of latent growth curve modeling and provides a detailed account of how such models can be constructed. Logical and statistical challenges that might arise when such analyses are conducted are also discussed. Specifically, we discuss how the initial status (intercept) and…

  7. Model Criticism of Bayesian Networks with Latent Variables.

    Science.gov (United States)

    Williamson, David M.; Mislevy, Robert J.; Almond, Russell G.

    This study investigated statistical methods for identifying errors in Bayesian networks (BN) with latent variables, as found in intelligent cognitive assessments. BN, commonly used in artificial intelligence systems, are promising mechanisms for scoring constructed-response examinations. The success of an intelligent assessment or tutoring system…

  8. Combining SNPs in latent variables to improve genomic prediction

    DEFF Research Database (Denmark)

    Heuven, Henri C M; Rosa, G J M; Janss, Luc

    The objective of this study was to develop and test hierarchical genomic models with latent variables that represent parts of the genomic values. An interaction model and a chromosome model were compared with a model based on variable selection in a simulated and real dataset. The program Bayz......: Hierarchical genetic model; Predictive value; Gibbs sampling; Variable selection....

  9. The relationship between cub and loglinear models with latent variables

    NARCIS (Netherlands)

    Oberski, D. L.; Vermunt, J. K.

    2015-01-01

    The "combination of uniform and shifted binomial"(cub) model is a distribution for ordinal variables that has received considerable recent attention and specialized development. This article notes that the cub model is a special case of the well-known loglinear latent class model, an observation tha

  10. Latent organizations in the film industry: contracts, rewards and resources

    NARCIS (Netherlands)

    Ebbers, J.J.; Wijnberg, N.M.

    2009-01-01

    The main aim of this article is to study the extent to which the project-based organization (PBO) and the latent organization determine the actual behavior of actors in a project-based industry and how this is mediated by the types of contracts and rewarding practices these organizational forms allo

  11. Multilevel Latent Class Analysis: Parametric and Nonparametric Models

    Science.gov (United States)

    Finch, W. Holmes; French, Brian F.

    2014-01-01

    Latent class analysis is an analytic technique often used in educational and psychological research to identify meaningful groups of individuals within a larger heterogeneous population based on a set of variables. This technique is flexible, encompassing not only a static set of variables but also longitudinal data in the form of growth mixture…

  12. Layout of a latent heat storage system with finned tubes

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, D.

    1980-10-26

    The theoretical and experimental investigations show by the example of Glauber's salt in a finned-tube latent heat storage vessel how heat transfer and storage capacity at charging and discharging depend on the variables of geometry, temperature, time and on the composition of the storing medium. By vertical arrangement of transversely finned tubes the separation problems occurring with Glauber's salt are solved insofar as the technical utilization of the latent heat of conversion corresponding to the complete conversion during charging and discharging not being possible, no decrease, of the reduced storage capacity, however, is found even after very many charging/discharging cycles. For the heat transfer during discharging correlations can be given on the basis of a model concept, be means of which a heat transfer coefficient, varying during the discharging process, can be predicted almost for the total range of discharge as a function of geometry, temperature and state of discharge. On the basis of the simple working formula for the heat transfer coefficient at crystallization of a latent heat storing medium the dynamic behavior of a compact finned-tube storage vessel can be predicted by means of a computer code. These means allow to perform the thermal design of a compact latent heat storage facility according to given design criteria accounting for economic aspects.

  13. A Hierarchical Latent Stochastic Differential Equation Model for Affective Dynamics

    Science.gov (United States)

    Oravecz, Zita; Tuerlinckx, Francis; Vandekerckhove, Joachim

    2011-01-01

    In this article a continuous-time stochastic model (the Ornstein-Uhlenbeck process) is presented to model the perpetually altering states of the core affect, which is a 2-dimensional concept underlying all our affective experiences. The process model that we propose can account for the temporal changes in core affect on the latent level. The key…

  14. Changes in latent fingerprint examiners' markup between analysis and comparison.

    Science.gov (United States)

    Ulery, Bradford T; Hicklin, R Austin; Roberts, Maria Antonia; Buscaglia, JoAnn

    2015-02-01

    After the initial analysis of a latent print, an examiner will sometimes revise the assessment during comparison with an exemplar. Changes between analysis and comparison may indicate that the initial analysis of the latent was inadequate, or that confirmation bias may have affected the comparison. 170 volunteer latent print examiners, each randomly assigned 22 pairs of prints from a pool of 320 total pairs, provided detailed markup documenting their interpretations of the prints and the bases for their comparison conclusions. We describe changes in value assessments and markup of features and clarity. When examiners individualized, they almost always added or deleted minutiae (90.3% of individualizations); every examiner revised at least some markups. For inconclusive and exclusion determinations, changes were less common, and features were added more frequently when the image pair was mated (same source). Even when individualizations were based on eight or fewer corresponding minutiae, in most cases some of those minutiae had been added during comparison. One erroneous individualization was observed: the markup changes were notably extreme, and almost all of the corresponding minutiae had been added during comparison. Latents assessed to be of value for exclusion only (VEO) during analysis were often individualized when compared to a mated exemplar (26%); in our previous work, where examiners were not required to provide markup of features, VEO individualizations were much less common (1.8%).

  15. The Latent Structure of Psychopathy in Youth: A Taxometric Investigation

    Science.gov (United States)

    Vasey, Michael W.; Kotov, Roman; Frick, Paul J.; Loney, Bryan R.

    2005-01-01

    Using taxometric procedures, the latent structure of psychopathy was investigated in two studies of children and adolescents. Prior studies have identified a taxon (i.e., a natural category) associated with antisocial behavior in adults as well as children and adolescents. However, features of this taxon suggest that it is not psychopathy but…

  16. Augmenting Latent Dirichlet Allocation and Rank Threshold Detection with Ontologies

    Science.gov (United States)

    2010-03-01

    Department of Defense, or the United States Government . AFIT/GCS/ENG/10-03 Augmenting Latent Dirichlet Allocation and Rank Threshold Detection with...dog great pyrenees dalmation dog domestic dog canis familiaris dog andiron firedog dog dog-iron frump dog pawl detent click dog chap fellow feller

  17. Some Determinants of Latent Inhibition in Human Predictive Learning

    Science.gov (United States)

    Pineno, Oskar; de la Casa, Luis Gonzalo; Lubow, R. E.; Miller, Ralph R.

    2006-01-01

    The present experiments assessed the effects of different manipulations between cue preexposure and cue-outcome pairings on latent inhibition (LI) in a predictive learning task with human participants. To facilitate LI, preexposure and acquisition with the target cues took place while participants performed a secondary task. Presentation of…

  18. Estrogen Abolishes Latent Inhibition in Ovariectomized Female Rats

    Science.gov (United States)

    Nofrey, Barbara S.; Ben-Shahar, Osnat M.; Brake, Wayne G.

    2008-01-01

    Estrogen is frequently prescribed as a method of birth control and as hormone replacement therapy for post-menopausal women with varied effects on cognition. Here the effects of estrogen on attention were examined using the latent inhibition (LI) behavioral paradigm. Ovariectomized (OVX) female rats were given either estrogen benzoate (EB, 10 or…

  19. Context-dependent latent inhibition in preweanling rats.

    Science.gov (United States)

    Revillo, D A; Gaztañaga, M; Aranda, E; Paglini, M G; Chotro, M G; Arias, C

    2014-11-01

    Preexposure to a conditioned stimulus (CS) usually weakens conditioning, an effect known as latent inhibition. Similar to other learning interference effects, latent inhibition has been characterized as context-dependent, which means that the magnitude of this effect can be attenuated by changing the context between the different phases of the procedure (e.g., preexposure and conditioning). Latent inhibition has been found with a variety of procedures in infant rats, but the few studies that examined the context-dependency of this phenomenon during this ontogenetic period found no context-change effect. The present study explored the context-dependency of latent inhibition during infancy using a conditioned taste aversion preparation and employing contexts enriched with distinctive odors to increase the possible efficacy of the context manipulation. Experiment 1 showed that three preexposures to the CS (saccharin) were sufficient to retard conditioning to the same CS, although this effect was also observed in a control group preexposed to an alternative taste stimulus (saline), in comparison with a non-preexposed control group. In Experiment 2a, the CS-preexposure effect was found to be specific to the preexposed CS when the number of preexposures was increased. This effect was revealed as context-dependent in Experiment 2b, since it was attenuated by changing the context between preexposure and conditioning. The present result is consistent with recent studies showing the context-dependency of extinction in preweanling rats, thus demonstrating these animals' capacity to learn about context early on in their development.

  20. Latent Inhibition in an Insect: The Role of Aminergic Signaling

    Science.gov (United States)

    Fernandez, Vanesa M.; Giurfa, Martin; Devaud, Jean-Marc; Farina, Walter M.

    2012-01-01

    Latent inhibition (LI) is a decrement in learning performance that results from the nonreinforced pre-exposure of the to-be-conditioned stimulus, in both vertebrates and invertebrates. In vertebrates, LI development involves dopamine and serotonin; in invertebrates there is yet no information. We studied differential olfactory conditioning of the…

  1. Rolipram attenuates MK-801-induced deficits in latent inhibition.

    Science.gov (United States)

    Davis, Jennifer A; Gould, Thomas J

    2005-04-01

    Latent inhibition is used to examine attention and study cognitive deficits associated with schizophrenia. Research using MK-801, an N-methyl-D-aspartate (NMDA) open channel blocker, implicates glutamate receptors in acquisition of latent inhibition of cued fear conditioning. Evidence suggests an important relationship between NMDA-induced increases in cyclic adenosine monophosphate (cAMP) and learning and memory. The authors examine whether amplification of the cAMP signaling pathway by rolipram, a selective Type 4 cAMP phosphodiesterase inhibitor, reverses MK-801-induced impairments in latent inhibition. One day before training, mice were injected with MK-801, rolipram, MK-801 and rolipram, or vehicle and received 20 preexposures or no preexposures to an auditory conditioned stimulus (CS). Training consisted of 2 CS-footshock unconditioned stimulus pairings. Rolipram attenuated the disruptive effect of MK-801 on latent inhibition, which suggests a role for the cAMP signaling pathway in the task and implicates phosphodiesterase inhibition as a target for treating cognitive impairments associated with schizophrenia.

  2. Bayesian latent feature modeling for modeling bipartite networks with overlapping groups

    DEFF Research Database (Denmark)

    Jørgensen, Philip H.; Mørup, Morten; Schmidt, Mikkel Nørgaard;

    2016-01-01

    Bi-partite networks are commonly modelled using latent class or latent feature models. Whereas the existing latent class models admit marginalization of parameters specifying the strength of interaction between groups, existing latent feature models do not admit analytical marginalization...... of the parameters accounting for the interaction strength within the feature representation. We propose a new binary latent feature model that admits analytical marginalization of interaction strengths such that model inference reduces to assigning nodes to latent features. We propose a constraint inspired...... to the infinite relational model and the infinite Bernoulli mixture model. We find that the model provides a new latent feature representation of structure while in link-prediction performing close to existing models. Our current extension of the notion of communities and collapsed inference to binary latent...

  3. Skin Resistivity Value of Upper Trapezius Latent Trigger Points

    Directory of Open Access Journals (Sweden)

    Elżbieta Skorupska

    2015-01-01

    Full Text Available Introduction. The skin resistivity (SkR measurement is commonly recommended for acupoints measurement, but for trigger points (TrPs only one study is available. The purpose of the study was to evaluate SkR for latent TrPs compared to non-TrPs and the surrounding tissue. Material and Methods. Forty-two healthy volunteers with unilateral latent upper trapezius TrPs (12 men, 30 women aged 21–23 (mean age: 22.1 ± 0.6 y participated in the study. Keithley electrometer 610B was used for measuring SkR (Ag/AgCl self-adhesive, disposable ground electrode: 30 mm diameter. SkR was measured for latent TrPs and compared to opposite non-TrPs sites and the surrounding tissue. Results. The SkR decrease of TrPs-positive sites as compared to TrPs-negative sites and the surrounding tissue was confirmed. However, no statistically significant difference in the SkR value occurred when all data were analyzed. The same was confirmed after gender division and for TrPs-positive subjects examined for referred pain and twitch response presence. Conclusion. SkR reactive changes at latent TrPs are possible but the results were not consistent with the previous study. Thus, caution in applying SkR to latent TrPs isolation is recommended and its clinical use should not be encouraged yet. Further studies, especially on active TrPs, are yet required.

  4. Exploring the Estimation of Examinee Locations Using Multidimensional Latent Trait Models under Different Distributional Assumptions

    Science.gov (United States)

    Jang, Hyesuk

    2014-01-01

    This study aims to evaluate a multidimensional latent trait model to determine how well the model works in various empirical contexts. Contrary to the assumption of these latent trait models that the traits are normally distributed, situations in which the latent trait is not shaped with a normal distribution may occur (Sass et al, 2008; Woods…

  5. Marginal Maximum Likelihood Estimation of a Latent Variable Model with Interaction

    Science.gov (United States)

    Cudeck, Robert; Harring, Jeffrey R.; du Toit, Stephen H. C.

    2009-01-01

    There has been considerable interest in nonlinear latent variable models specifying interaction between latent variables. Although it seems to be only slightly more complex than linear regression without the interaction, the model that includes a product of latent variables cannot be estimated by maximum likelihood assuming normality.…

  6. Defining a Family of Cognitive Diagnosis Models Using Log-Linear Models with Latent Variables

    Science.gov (United States)

    Henson, Robert A.; Templin, Jonathan L.; Willse, John T.

    2009-01-01

    This paper uses log-linear models with latent variables (Hagenaars, in "Loglinear Models with Latent Variables," 1993) to define a family of cognitive diagnosis models. In doing so, the relationship between many common models is explicitly defined and discussed. In addition, because the log-linear model with latent variables is a general model for…

  7. Stochastic Approximation Methods for Latent Regression Item Response Models. Research Report. ETS RR-09-09

    Science.gov (United States)

    von Davier, Matthias; Sinharay, Sandip

    2009-01-01

    This paper presents an application of a stochastic approximation EM-algorithm using a Metropolis-Hastings sampler to estimate the parameters of an item response latent regression model. Latent regression models are extensions of item response theory (IRT) to a 2-level latent variable model in which covariates serve as predictors of the…

  8. Polytomous latent scales for the investigation of the ordering of items

    NARCIS (Netherlands)

    Ligtvoet, R.; van der Ark, L.A.; Bergsma, W. P.; Sijtsma, K.

    2011-01-01

    We propose three latent scales within the framework of nonparametric item response theory for polytomously scored items. Latent scales are models that imply an invariant item ordering, meaning that the order of the items is the same for each measurement value on the latent scale. This ordering prope

  9. Studies of Phase Change Materials and a Latent Heat Storage Unit Used for a Natural Circulation Cooling/Latent Heat Storage System

    Science.gov (United States)

    Sakitani, Katsumi; Honda, Hiroshi

    Experimental and theoretical studies were made of the heat transfer characteristics of a latent heat storage unit used for a natural circulation cooling /latent heat storage system. Heating and cooling curves of the latent heat storage unit undergoing solid-liquid phase change of a PCM (lauric acid) was obtained by using anatural circulation loop of R22 which consisted of an electrically heated evaporater, a water cooled condenser and the latent heat storage unit. The latent heat storage unit showed a heat transfer performance which was high enough for practical use. An approximate theoretical analysis was conducted to investigate transient behavior of the latent heat storage unit. Predictions of the refrigerant and outer surface temperatures during the melting process were in fair agreement with the experimental data, whereas that of the refrigerant temperature during the solidification process was considerably lower than the measurement.

  10. Viral Interleukin-10 Expressed by Human Cytomegalovirus during the Latent Phase of Infection Modulates Latently Infected Myeloid Cell Differentiation ▿ †

    OpenAIRE

    Avdic, Selmir; Cao, John Z.; Cheung, Allen K.L.; Abendroth, Allison; Slobedman, Barry

    2011-01-01

    The human cytomegalovirus UL111A gene is expressed during latent and productive infections, and it codes for homologs of interleukin-10 (IL-10). We examined whether viral IL-10 expressed during latency altered differentiation of latently infected myeloid progenitors. In comparison to infection with parental virus or mock infection, latent infection with a virus in which the gene encoding viral IL-10 has been deleted upregulated cytokines associated with dendritic cell (DC) formation and incre...

  11. Activation of Latent HIV Using Drug-loaded Nanoparticles

    Science.gov (United States)

    Kovochich, Michael

    Antiretroviral therapy is currently only capable of controlling human immunodeficiency virus (HIV) replication, rather than completely eradicating virus from patients. This is due in part to the establishment of a latent virus reservoir in resting CD4+ T-cells, which persists even in the presence of highly active antiretroviral therapy (HAART). It is thought that forced activation of latently infected cells could induce virus production, allowing targeting of the cell by the immune response. A variety of molecules are able to stimulate HIV from latency. However, no tested purging strategy has proven capable of eliminating the infection completely or preventing viral rebound if therapy is stopped. Hence, novel latency activation approaches are required. Nanoparticles can offer several advantages over more traditional drug delivery methods, including improved drug solubility, stability, and the ability to simultaneously target multiple different molecules to particular cell or tissue types. Here we describe the development of a novel lipid nanoparticle with the protein kinase C activator bryostatin-2 incorporated (LNP-Bry). These particles can target, activate primary human CD4+ T-cells, and stimulate latent virus production from human T-cell lines in vitro and from latently infected cells in a humanized mouse model ex vivo. This activation was synergistically enhanced by the histone deacetylase inhibitor (HDACi) sodium butyrate. Furthermore, LNP-Bry can also be loaded with the protease inhibitor nelfinavir (LNP-Bry-Nel), producing a particle capable of both activating latent virus and inhibiting viral spread. LNP-Bry was further tested for its in vivo biodistribution in both wild type mice (C57 black 6), as well as humanized mice (SCID-hu Thy/Liv, and bone marrow-liver-thymus [BLT]). LNP-Bry accumulated in the spleen and induced the early activation marker CD69 in wild type mice. Taken together, these data demonstrate the ability of nanotechnological approaches to

  12. Fronteras porosas: la minería ilegal y el narcotráfico como amenazas latentes a la seguridad

    Directory of Open Access Journals (Sweden)

    Diana Isabel Ocampo Rodríguez

    2015-10-01

    Full Text Available El crimen transnacional se ha consolidado como una amenaza latente para la seguridad del Estado colombiano y de otros países de la región demandando acciones estratégicas por parte de la fuerza pública que vayan más allá de las operaciones conjuntas y coordinadas exigiendo, por su capacidad y dinamismo, que se actúe bajo un marco de interoperabilidad. En este sentido, se da a conocer un análisis descriptivo de dos de las principales amenazas transnacionales que afectan algunos países latinoamericanos y un planteamiento de la autora sobre cuál debe ser la estrategia para enfrentar este tipo de desafíos. El presente artículo de reflexión se desarrolla en tres fases con un enfoque de investigación cualitativo y de tipo de revisión documental descriptiva y propositiva. La primera corresponde a un análisis sobre la evolución del concepto de seguridad y el crimen transnacional, la segunda al estudio del caso específico del narcotráfico y la minería ilegal, y la tercera a las recomendaciones que se plantean con el fin de evidenciar por qué se debe hacer frente de manera coordinada y bajo un marco de cooperación e integración entre los Estados.

  13. Explicit estimating equations for semiparametric generalized linear latent variable models

    KAUST Repository

    Ma, Yanyuan

    2010-07-05

    We study generalized linear latent variable models without requiring a distributional assumption of the latent variables. Using a geometric approach, we derive consistent semiparametric estimators. We demonstrate that these models have a property which is similar to that of a sufficient complete statistic, which enables us to simplify the estimating procedure and explicitly to formulate the semiparametric estimating equations. We further show that the explicit estimators have the usual root n consistency and asymptotic normality. We explain the computational implementation of our method and illustrate the numerical performance of the estimators in finite sample situations via extensive simulation studies. The advantage of our estimators over the existing likelihood approach is also shown via numerical comparison. We employ the method to analyse a real data example from economics. © 2010 Royal Statistical Society.

  14. Identification of Novel Type III Effectors Using Latent Dirichlet Allocation

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2012-01-01

    Full Text Available Among the six secretion systems identified in Gram-negative bacteria, the type III secretion system (T3SS plays important roles in the disease development of pathogens. T3SS has attracted a great deal of research interests. However, the secretion mechanism has not been fully understood yet. Especially, the identification of effectors (secreted proteins is an important and challenging task. This paper adopts machine learning methods to identify type III secreted effectors (T3SEs. We extract features from amino acid sequences and conduct feature reduction based on latent semantic information by using latent Dirichlet allocation model. The experimental results on Pseudomonas syringae data set demonstrate the good performance of the new methods.

  15. Latent state-space models for neural decoding.

    Science.gov (United States)

    Aghagolzadeh, Mehdi; Truccolo, Wilson

    2014-01-01

    Ensembles of single-neurons in motor cortex can show strong low-dimensional collective dynamics. In this study, we explore an approach where neural decoding is applied to estimated low-dimensional dynamics instead of to the full recorded neuronal population. A latent state-space model (SSM) approach is used to estimate the low-dimensional neural dynamics from the measured spiking activity in population of neurons. A second state-space model representation is then used to decode kinematics, via a Kalman filter, from the estimated low-dimensional dynamics. The latent SSM-based decoding approach is illustrated on neuronal activity recorded from primary motor cortex in a monkey performing naturalistic 3-D reach and grasp movements. Our analysis show that 3-D reach decoding performance based on estimated low-dimensional dynamics is comparable to the decoding performance based on the full recorded neuronal population.

  16. The latent structure of secure base script knowledge.

    Science.gov (United States)

    Waters, Theodore E A; Fraley, R Chris; Groh, Ashley M; Steele, Ryan D; Vaughn, Brian E; Bost, Kelly K; Veríssimo, Manuela; Coppola, Gabrielle; Roisman, Glenn I

    2015-06-01

    There is increasing evidence that attachment representations abstracted from childhood experiences with primary caregivers are organized as a cognitive script describing secure base use and support (i.e., the secure base script). To date, however, the latent structure of secure base script knowledge has gone unexamined-this despite that such basic information about the factor structure and distributional properties of these individual differences has important conceptual implications for our understanding of how representations of early experience are organized and generalized, as well as methodological significance in relation to maximizing statistical power and precision. In this study, we report factor and taxometric analyses that examined the latent structure of secure base script knowledge in 2 large samples. Results suggested that variation in secure base script knowledge-as measured by both the adolescent (N = 674) and adult (N = 714) versions of the Attachment Script Assessment-is generalized across relationships and continuously distributed.

  17. Switched Dynamical Latent Force Models for Modelling Transcriptional Regulation

    CERN Document Server

    López-Lopera, Andrés F

    2015-01-01

    In order to develop statistical approaches for transcription networks, statistical community has proposed several methods to infer activity levels of proteins, from time-series measurements of targets' expression levels. A few number of approaches have been proposed in order to outperform the representation of fast switching time instants, but computational overheads are significant due to complex inference algorithms. Using the theory related to latent force models (LFM), the development of this project provide a switched dynamical hybrid model based on Gaussian processes (GPs). To deal with discontinuities in dynamical systems (or latent driving force), an extension of the single input motif approach is introduced, that switches between different protein concentrations, and different dynamical systems. This creates a versatile representation for transcription networks that can capture discrete changes and non-linearities in the dynamics. The proposed method is evaluated on both simulated data and real data,...

  18. Modeling the latent dimensions of multivariate signaling datasets

    Science.gov (United States)

    Jensen, Karin J.; Janes, Kevin A.

    2012-08-01

    Cellular signal transduction is coordinated by modifications of many proteins within cells. Protein modifications are not independent, because some are connected through shared signaling cascades and others jointly converge upon common cellular functions. This coupling creates a hidden structure within a signaling network that can point to higher level organizing principles of interest to systems biology. One can identify important covariations within large-scale datasets by using mathematical models that extract latent dimensions—the key structural elements of a measurement set. In this paper, we introduce two principal component-based methods for identifying and interpreting latent dimensions. Principal component analysis provides a starting point for unbiased inspection of the major sources of variation within a dataset. Partial least-squares regression reorients these dimensions toward a specific hypothesis of interest. Both approaches have been used widely in studies of cell signaling, and they should be standard analytical tools once highly multivariate datasets become straightforward to accumulate.

  19. Application of evolutionary algorithm for cast iron latent heat identification

    Directory of Open Access Journals (Sweden)

    J. Mendakiewicz

    2008-12-01

    Full Text Available In the paper the cast iron latent heat in the form of two components corresponding to the solidification of austenite and eutectic phases is assumed. The aim of investigations is to estimate the values of austenite and eutectic latent heats on the basis of cooling curve at the central point of the casting domain. This cooling curve has been obtained both on the basis of direct problem solution as well as from the experiment. To solve such inverse problem the evolutionary algorithm (EA has been applied. The numerical computations have been done using the finite element method by means of commercial software MSC MARC/MENTAT. In the final part of the paper the examples of identification are shown.

  20. Disruption of overshadowing and latent inhibition in high schizotypy individuals.

    Science.gov (United States)

    Granger, K T; Prados, J; Young, A M J

    2012-07-15

    Deficits in selective attention are seen in positively symptomatic schizophrenia sufferers, and in normal people displaying schizotypal traits. We investigated the relationship between selective attention and schizotypy in undergraduate students, by comparing participants' performance in two models of selective attention, overshadowing and latent inhibition, with psychoticism scores derived from the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE). Using a novel within-subject overshadowing task, we showed that the unusual experiences dimension of schizotypy, but not the other three O-LIFE dimensions, was negatively related to overshadowing score. We also replicated findings that the unusual experiences dimension of schizotypy was negatively related to latent inhibition score. These experiments provide evidence that selective attention is disrupted in normal individuals showing traits relating to positive-like schizophrenic symptoms, and has implications for interpreting selective attention deficits measured in schizophrenia patients.

  1. Prevalence of latent alpha-herpesviruses in Thoroughbred racing horses.

    Science.gov (United States)

    Pusterla, Nicola; Mapes, Samantha; David Wilson, W

    2012-08-01

    The objective of this study was to detect and characterize latent equine herpes virus (EHV)-1 and -4 from the submandibular (SMLN) and bronchial lymph (BLN) nodes, as well as from the trigeminal ganglia (TG) of 70 racing Thoroughbred horses submitted for necropsy following sustaining serious musculoskeletal injuries while racing. A combination of nucleic acid precipitation and pre-amplification steps was used to increase analytical sensitivity. Tissues were deemed positive for latent EHV-1 and/or -4 infection when found PCR positive for the corresponding glycoprotein B (gB) gene in the absence of detectable late structural protein gene (gB gene) mRNA. The EHV-1 genotype was also determined using a discriminatory real-time PCR assay targeting the DNA polymerase gene (ORF 30). Eighteen (25.7%) and 58 (82.8%) horses were PCR positive for the gB gene of EHV-1 and -4, respectively, in at least one of the three tissues sampled. Twelve horses were dually infected with EHV-1 and -4, two carried a latent neurotropic strain of EHV-1, six carried a non-neurotropic genotype of EHV-1 and 10 were dually infected with neurotropic and non-neurotropic EHV-1. The distribution of latent EHV-1 and -4 infection varied in the samples, with the TG found to be most commonly infected. Overall, non-neurotropic strains were more frequently detected than neurotropic strains, supporting the general consensus that non-neurotropic strains are more prevalent in horse populations, and hence the uncommon occurrence of equine herpes myeloencephalopathy.

  2. Reactivation of latent viruses after treatment with biological therapies

    Directory of Open Access Journals (Sweden)

    Asthana AK

    2014-06-01

    Full Text Available Anil Kumar Asthana,1 John Samuel Lubel2,31Department of Gastroenterology, The Alfred Hospital, Melbourne, 2Department of Gastroenterology and Hepatology, Eastern Health, 3Eastern Health Clinical School, Monash University, Melbourne, VIC, AustraliaAbstract: Biological therapies are used extensively for malignant (eg, lymphoma and autoimmune (eg, rheumatoid arthritis conditions. These agents include anti-tumor necrosis factor antagonists, such as infliximab, and B-cell-depleting therapies, such as rituximab. In the past decade, there has been an explosion in the types and numbers of agents being used. One of the known risks with these agents is infection. In particular, there is increasing awareness regarding latent virus reactivation. This occurs when a latent virus is reactivated into its active replicative phase as a result of an internal or external trigger, such as immunosuppression. It is challenging, however, to quantitatively attribute the risk of reactivation to biological therapy alone because the underlying malignant or autoimmune condition could also be a contributing factor. There is well documented evidence regarding the reactivation of viruses such as hepatitis B virus and cytomegalovirus with drugs such as rituximab. Long-term data are lacking; such data are essential to guide risk stratification and chemoprophylaxis. Universally accepted viral screening guidelines prior to commencement of immunosuppression are lacking. As an example, the US Centers for Disease Control and Prevention have published recommendations regarding hepatitis B virus screening prior to commencing immunosuppression, but this action has not translated into universally accepted guidelines. Some of the other relevant viruses involved include cytomegalovirus, hepatitis C virus, varicella zoster virus, Epstein–Barr virus, and other members of the herpes family. This article reviews the current literature on the risk of latent viral reactivation with biological

  3. THE IMPACT OF PROMOTION AND ADVERTISING: A LATENT CLASS APPROACH

    OpenAIRE

    Richards, Timothy J.

    2000-01-01

    Typically, marketers define market segments by their demographic characteristics, assuming that these segments represent consumers with relatively homogeneous buying patterns. A more managerially useful definition, however, groups consumers of similar behavior directly and then seeks to find demographic commonalities among them. This study uses a latent class analysis technique to segment consumers based on their responsiveness to a set of marketing variables, finding that a multiple-segment ...

  4. Potential immunomodulatory effects of latent toxoplasmosis in humans

    Directory of Open Access Journals (Sweden)

    Stříž Ilja

    2011-10-01

    Full Text Available Abstract Background About 30% of the population worldwide are infected with the protozoan parasite Toxoplasma gondii. Latent toxoplasmosis has many specific behavioral and physiological effects on the human organism. Modified reactivity of the immune system has been suggested to play a key role in many of these effects. For example, the immunosuppression hypothesis explains the higher probability of the birth of male offspring observed in Toxoplasma-positive humans and mice by the protection of the (more immunogenic male embryos against abortion. Methods Here we searched for indices of immunosuppression in Toxoplasma-positive subjects by comparing clinical records of immunology outpatients. Results Our cohort study showed that the male patients with latent toxoplasmosis had decreased and the Toxoplasma-positive women had increased leukocyte, NK-cell and monocyte counts in comparison with controls. The B-cell counts were reduced in both Toxoplasma-positive men and women. The difference between Toxoplasma-positive and Toxoplasma-negative subjects diminished with the decline of the specific Toxoplasma antibody titre (a proxy for the length of infection, which is consistent with the observed decreasing strength of the effect of latent toxoplasmosis on human reproduction. The prevalence of toxoplasmosis in 128 male patients was unusually low (10.9% which contrasted with normal prevalence in 312 female patients (23.7% and in general population Prague (20-30%. Conclusions Latent toxoplasmosis has immunomodulatory effects in human and probably protects men against some classes of immunopathological diseases. The main limitation of the present study was the absence of the data on the immunoreactivity of immune cells subpopulations. Therefore further studies are needed to search for indices of immunosuppression in human using more specific markers.

  5. A discrete latent factor model for smoking, cancer and mortality.

    OpenAIRE

    Howdon, D.; Jones, A

    2013-01-01

    This paper investigates the relationships between social circumstances, individual behaviours, and ill-health later in life, with a particular focus on the development of cancer. A discrete latent factor model incorporating individuals' smoking and health outcomes (lifespan and time-to-cancer) is jointly estimated, using the 1984/5 British Health and Lifestyle Survey (HALS) dataset and its July 2009 follow-up, allowing for unobservable factors to affect decisions regarding smoking behaviours ...

  6. Sex determination of human skeletal populations using latent profile analysis.

    Science.gov (United States)

    Passalacqua, Nicholas V; Zhang, Zhen; Pierce, Steven J

    2013-08-01

    Accurately estimating biological sex from the human skeleton can be especially difficult for fragmentary or incomplete remains often encountered in bioarchaeological contexts. Where typical anatomically dimorphic skeletal regions are incomplete or absent, observers often take their best guess to classify biological sex. Latent profile analysis (LPA) is a mixture modeling technique which uses observed continuous data to estimate unobserved categorical group membership using posterior probabilities. In this study, sex is the latent variable (male and female are the two latent classes), and the indicator variables used here were eight standard linear measurements (long bone lengths, diaphyseal and articular breadths, and circumferences). Mplus (Muthén and Muthén: Mplus user's guide, 6th ed. Los Angeles: Muthén & Muthén, 2010) was used to obtain maximum likelihood estimates for latent class membership from a known sample of individuals from the forensic data bank (FDB) (Jantz and Moore-Jansen: Database for forensic anthropology in the United States 1962-1991, Ann Arbor, MI: Interuniversity Consortium for Political and Social Research, 2000) (n = 1,831), yielding 87% of correct classification for sex. Then, a simulation extracted 5,000 different random samples of 206 complete cases each from the FDB (these cases also had known sex). We then artificially imposed patterns of missing data similar to that observed in a poorly preserved bioarchaeological sample from Medieval Asturias, Spain (n = 206), and ran LPA on each sample. This tested the efficacy of LPA under extreme conditions of poor preservation (missing data, 42%). The simulation yielded an average of 82% accuracy, indicating that LPA is robust to large amounts of missing data when analyzing incomplete skeletons.

  7. Linear latent variable models: the lava-package

    DEFF Research Database (Denmark)

    Holst, Klaus Kähler; Budtz-Jørgensen, Esben

    2013-01-01

    An R package for specifying and estimating linear latent variable models is presented. The philosophy of the implementation is to separate the model specification from the actual data, which leads to a dynamic and easy way of modeling complex hierarchical structures. Several advanced features...... are implemented including robust standard errors for clustered correlated data, multigroup analyses, non-linear parameter constraints, inference with incomplete data, maximum likelihood estimation with censored and binary observations, and instrumental variable estimators. In addition an extensive simulation...

  8. Modeling, estimation and identification of stochastic systems with latent variables

    OpenAIRE

    Bottegal, Giulio

    2013-01-01

    The main topic of this thesis is the analysis of static and dynamic models in which some variables, although directly influencing the behavior of certain observables, are not accessible to measurements. These models find applications in many branches of science and engineering, such as control systems, communications, natural and biological sciences and econometrics. It is well-known that models with unaccessible - or latent - variables, usually suffer from a lack of uniqueness of representat...

  9. Segmentation and Enhancement of Latent Fingerprints: A Coarse to Fine Ridge Structure Dictionary.

    Science.gov (United States)

    Cao, Kai; Liu, Eryun; Jain, Anil K

    2014-09-01

    Latent fingerprint matching has played a critical role in identifying suspects and criminals. However, compared to rolled and plain fingerprint matching, latent identification accuracy is significantly lower due to complex background noise, poor ridge quality and overlapping structured noise in latent images. Accordingly, manual markup of various features (e.g., region of interest, singular points and minutiae) is typically necessary to extract reliable features from latents. To reduce this markup cost and to improve the consistency in feature markup, fully automatic and highly accurate ("lights-out" capability) latent matching algorithms are needed. In this paper, a dictionary-based approach is proposed for automatic latent segmentation and enhancement towards the goal of achieving "lights-out" latent identification systems. Given a latent fingerprint image, a total variation (TV) decomposition model with L1 fidelity regularization is used to remove piecewise-smooth background noise. The texture component image obtained from the decomposition of latent image is divided into overlapping patches. Ridge structure dictionary, which is learnt from a set of high quality ridge patches, is then used to restore ridge structure in these latent patches. The ridge quality of a patch, which is used for latent segmentation, is defined as the structural similarity between the patch and its reconstruction. Orientation and frequency fields, which are used for latent enhancement, are then extracted from the reconstructed patch. To balance robustness and accuracy, a coarse to fine strategy is proposed. Experimental results on two latent fingerprint databases (i.e., NIST SD27 and WVU DB) show that the proposed algorithm outperforms the state-of-the-art segmentation and enhancement algorithms and boosts the performance of a state-of-the-art commercial latent matcher.

  10. [Latent infection of human herpes virus in hematopoietic system].

    Science.gov (United States)

    Wu, Ke-Fu; Ma, Xiao-Tong; Zheng, Guo-Guang; Song, Yu-Hua

    2008-12-01

    Up to date, eight types of human herpes viruses have been identified, all of which are ubiquitous, and usually establish latent infection in the host after primary infection. Since most of the herpes viruses are maintained in an asymptomatic form, they are often neglected. However, under some circumstances, these herpes viruses can cause fatal or severe diseases. Furthermore, the association of herpes viruses with hematopoietic malignancies is attracting researchers' attention. With the extensive development of hematopoietic stem cell and organ transplantation, reports regarding transplantation failure and complication caused by infection of human herpes virus has been increasing. Cytokine storm was firstly suggested as the mechanism of graft-versus-host diseases. In recent years, which has also been applied in the pathogenesis research of inflammation, and is supposed to play an important role in severe virus infection. In this paper, through discussing the possible role of latent infection of human herpes virus in the failure or complication of bone marrow or hematopoietic stem cell transplantation, and in refractory leukemia, the function and significance of latent infection of human herpes virus and the cytokine storm it caused were investigated.

  11. Recovery of latent fingerprints and DNA on human skin.

    Science.gov (United States)

    Färber, Doris; Seul, Andrea; Weisser, Hans-Joachim; Bohnert, Michael

    2010-11-01

    The project "Latent Fingerprints and DNA on Human Skin" was the first systematic research in Europe dealing with detection of fingerprints and DNA left by offenders on the skin of corpses. One thousand samples gave results that allow general statements on the materials and methods used. The tests were carried out according to a uniform trial structure. Fingerprints were deposited by natural donors on corpses. The latent fingerprints were treated with magnetic powder or black fingerprint powder. Afterward, they were lifted with silicone casting material (Isomark(®)) or gelatine foil. All lifts were swabbed to recover DNA. It was possible to visualize comparable and identifiable fingerprints on the skin of corpses (16%). In the same categories, magnetic powder (18.4%) yielded better results than black fingerprint powder (13.6%). The number of comparable and identifiable fingerprints decreased on the lifts (12.7%). Isomark(®) (14.9%) was the better lifting material in comparison with gelatine foil (10.1%). In one-third of the samples, DNA could be extracted from the powdered and lifted latents. Black fingerprint powder delivered the better result with a rate of 2.2% for full DNA profiles and profiles useful for exclusion in comparison with 1.8% for the magnetic powder traces. Isomark(®) (3.1%) yielded better results than gelatine foil (0.6%).

  12. Latent structure and construct validity of the reinforcement sensitivity questionnaire

    Directory of Open Access Journals (Sweden)

    Mitrović Dušanka

    2008-01-01

    Full Text Available The Revised reinforcement sensitivity theory contains three basic systems: Behavioral inhibition system (BAS, Behavioral activation system (BIS and the Fight/ Flight/ Freeze (FFF system. In this model, BIS is a system for detection of potential conflict or threat, and FFFS differs three basic patterns of reaction to actual or perceived danger. In Study 1, which was aimed at the examination of the latent structure of the RSQ, was conducted on a sample of 472 participants of both genders. The best - fitting model suggests that, at the top level of hierarchy, three dimensions exist, which are analogous to the BIS, BAS and FFF. The last dimension contains three subordinate dimensions, which represent the subsystems of the FFF. Study 2, in which 203 subjects participated, was aimed at examination of the relations between the dimensions of the Revised reinforcement sensitivity theory and dimensions of the PEN model. Confirmatory factor analyses of the RSQ and EPQ-R dimensions revealed that the best-fitting model comprised three latent dimensions, the first one being analogous to the BIS - Neuroticism, the second one to the BAS - Extraversion, and the third to the Aggressiveness- Psychoticism. The structure of the latent dimensions is in accordance with the expectations. The results state that fear and anxiety (which neurophysiological distinction is emphasized by Gray, are substantively similar on the behavioral level. Also, the results suggest that the Freeze dimension is probably closer to the BIS system than to the FFF.

  13. Latent developmental and evolutionary shapes embedded within the grapevine leaf.

    Science.gov (United States)

    Chitwood, Daniel H; Klein, Laura L; O'Hanlon, Regan; Chacko, Steven; Greg, Matthew; Kitchen, Cassandra; Miller, Allison J; Londo, Jason P

    2016-04-01

    Across plants, leaves exhibit profound diversity in shape. As a single leaf expands, its shape is in constant flux. Plants may also produce leaves with different shapes at successive nodes. In addition, leaf shape varies among individuals, populations and species as a result of evolutionary processes and environmental influences. Because leaf shape can vary in many different ways, theoretically, the effects of distinct developmental and evolutionary processes are separable, even within the shape of a single leaf. Here, we measured the shapes of > 3200 leaves representing > 270 vines from wild relatives of domesticated grape (Vitis spp.) to determine whether leaf shapes attributable to genetics and development are separable from each other. We isolated latent shapes (multivariate signatures that vary independently from each other) embedded within the overall shape of leaves. These latent shapes can predict developmental stages independent from species identity and vice versa. Shapes predictive of development were then used to stage leaves from 1200 varieties of domesticated grape (Vitis vinifera), revealing that changes in timing underlie leaf shape diversity. Our results indicate that distinct latent shapes combine to produce a composite morphology in leaves, and that developmental and evolutionary contributions to shape vary independently from each other.

  14. Statistical study and review of prostatic latent carcinoma

    Directory of Open Access Journals (Sweden)

    Jamali M

    1996-06-01

    Full Text Available The autopsies, which have been performed within the last 50 years, have revealed that real prevalence of prostatic carcinoma is more frequent than clinical one. The real prevalence of prostatic carcinoma, is prevalence combination of carcinomas which have been revealed clinically (They have been confirmed by autopsy or by operation and the prostatic latent carcinomas are those, which are found in autopsy or randomly in the biopsies taken for hyperplasia. But they have no clinical syndromes. In order to review prevalence of prostatic latent carcinoma in Iran, all prostatic lesions (Including hyperplasia or carcinoma were studied in Imam Khomeini medical complex during 10 years (1981-91, in university Jihad center and medical center of Iran within 2 years and in Yazd faculty of medicine within 3 years (1981-84. The total cases were 1110 among which 1085 cases were selected upon reviewing for statistical analysis. At first all lamellas were studied, then the ratio of adenocarcinoma to total prostatic lesions were analyzed and types of carcinoma and their percentage in total cases were identified. Finally the prostatic latent carcinoma and its percentage in total malignancy cases were presented

  15. Modeling healthcare data using multiple-channel latent Dirichlet allocation.

    Science.gov (United States)

    Lu, Hsin-Min; Wei, Chih-Ping; Hsiao, Fei-Yuan

    2016-04-01

    Information and communications technologies have enabled healthcare institutions to accumulate large amounts of healthcare data that include diagnoses, medications, and additional contextual information such as patient demographics. To gain a better understanding of big healthcare data and to develop better data-driven clinical decision support systems, we propose a novel multiple-channel latent Dirichlet allocation (MCLDA) approach for modeling diagnoses, medications, and contextual information in healthcare data. The proposed MCLDA model assumes that a latent health status group structure is responsible for the observed co-occurrences among diagnoses, medications, and contextual information. Using a real-world research testbed that includes one million healthcare insurance claim records, we investigate the utility of MCLDA. Our empirical evaluation results suggest that MCLDA is capable of capturing the comorbidity structures and linking them with the distribution of medications. Moreover, MCLDA is able to identify the pairing between diagnoses and medications in a record based on the assigned latent groups. MCLDA can also be employed to predict missing medications or diagnoses given partial records. Our evaluation results also show that, in most cases, MCLDA outperforms alternative methods such as logistic regressions and the k-nearest-neighbor (KNN) model for two prediction tasks, i.e., medication and diagnosis prediction. Thus, MCLDA represents a promising approach to modeling healthcare data for clinical decision support.

  16. Latent resonance in tidal rivers, with applications to River Elbe

    Science.gov (United States)

    Backhaus, Jan O.

    2015-11-01

    We describe a systematic investigation of resonance in tidal rivers, and of river oscillations influenced by resonance. That is, we explore the grey-zone between absent and fully developed resonance. Data from this study are the results of a one-dimensional numerical channel model applied to a four-dimensional parameter space comprising geometry, i.e. length and depths of rivers, and varying dissipation and forcing. Similarity of real rivers and channels from parameter space is obtained with the help of a 'run-time depth'. We present a model-channel, which reproduces tidal oscillations of River Elbe in Hamburg, Germany with accuracy of a few centimetres. The parameter space contains resonant regions and regions with 'latent resonance'. The latter defines tidal oscillations that are elevated yet not in full but juvenile resonance. Dissipation reduces amplitudes of resonance while creating latent resonance. That is, energy of resonance radiates into areas in parameter space where periods of Eigen-oscillations are well separated from the period of the forcing tide. Increased forcing enhances the re-distribution of resonance in parameter space. The River Elbe is diagnosed as being in a state of anthropogenic latent resonance as a consequence of ongoing deepening by dredging. Deepening the river, in conjunction with the expected sea level rise, will inevitably cause increasing tidal ranges. As a rule of thumb, we found that 1 m deepening would cause 0.5 m increase in tidal range.

  17. Limits of the lab: diagnosing "latent gonorrhea," 1872-1910.

    Science.gov (United States)

    Bowen, Elliott

    2013-01-01

    One of the most heatedly contested disease entities in turn-of-the-century medicine was "latent gonorrhea," a condition first discussed in an 1872 paper published by the German-born gynecologist Emil Noeggerath. Although none of the bacteriological discoveries of the next few decades-including the isolation of the gonococcus in 1879-provided much evidence of its existence, by the 1890s most Western physicians and medical scientists had nonetheless come to believe that latent gonorrhea was a real, diagnosable disease. While in the wake of its resolution, leading gynecologists contended that laboratory science had cleared up the controversy over latent gonorrhea, in reality it was through more "traditional" diagnostic methods (especially the taking of case histories) that Noeggerath's once-debatable theory gained acceptance. As such, this episode challenges the idea that turn-of-the-century Western medicine witnessed a "laboratory revolution," and that with the rise of bacteriology "the clinic" no longer informed the processes by which doctors defined and diagnosed disease.

  18. Psychiatric comorbidity among adults with schizophrenia: a latent class analysis.

    Science.gov (United States)

    Tsai, Jack; Rosenheck, Robert A

    2013-11-30

    Schizophrenia is a severe mental illness that often co-occurs with and can be exacerbated by other psychiatric conditions. There have not been adequate efforts to examine schizophrenia and psychiatric comorbidity beyond pairwise examination using clusters of diagnoses. This study used latent class analysis to characterize patterns of 5-year psychiatric comorbidity among a national sample of adults with schizophrenia. Baseline data from 1446 adults with schizophrenia across 57 sites in the United States were analyzed. Three latent classes were identified labeled Solely Schizophrenia, Comorbid Anxiety and Depressive Disorders with Schizophrenia, and Comorbid Addiction and Schizophrenia. Adults in the Solely Schizophrenia class had significantly better mental health than those in the two comorbid classes, but poorer illness and treatment insight than those with comorbid anxiety and depressive disorders. These results suggest that addiction and schizophrenia may represent a separate latent profile from depression, anxiety, and schizophrenia. More research is needed on how treatment can take advantage of the greater insight possessed by those with schizophrenia and comorbid anxiety and depression.

  19. Acción terapéutica de cortistatina en la encefalomielitis autoinmune experimental y el efecto paradójico de su ausencia en inflamación y autoinmunidad

    OpenAIRE

    2013-01-01

    La esclerosis múltiple (EM) es una enfermedad neurodegenerativa autoinmunitaria inflamatoria crónica que cursa con destrucción de la mielina y causa alteraciones neurológicas graves. Actualmente se desconoce su etiología, aunque se ha demostrado que existe un componente inflamatorio y autoinmunitario. Se produce neurodegeneración mediada por células T autorreactivas Th1/Th17 acompañada por un desbalance de células T reguladoras (Treg) responsables del mantenimiento de la tolerancia inmunológi...

  20. The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons.

    Science.gov (United States)

    Nicoll, Michael P; Hann, William; Shivkumar, Maitreyi; Harman, Laura E R; Connor, Viv; Coleman, Heather M; Proença, João T; Efstathiou, Stacey

    2016-04-01

    Herpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir.

  1. EVALUACIÓN AUTOMÁTICA DE COHERENCIA TEXTUAL EN NOTICIAS POLICIALES UTILIZANDO ANÁLISIS SEMÁNTICO LATENTE AUTOMATIC EVALUATION OF TEXTUAL COHERENCE IN POLICE NEWS USING LATENT SEMANTIC ANALYSIS

    Directory of Open Access Journals (Sweden)

    SERGIO HERNÁNDEZ OSUNA

    2010-01-01

    Full Text Available El presente artículo expone los resultados de una investigación que buscó evaluar la coherencia textual en forma automática, utilizando el método de Análisis Semántico Latente, en el dominio formado por noticias policiales. Con este fin se construyó una herramienta prototipo, empleando únicamente software libre, que se puede obtener desde Internet. Para validar el funcionamiento del prototipo se comparó su evaluación con la realizada por ocho evaluadores humanos: cuatro periodistas y cuatro profesores de español con estudios de postgrado en lingüística.This article presents the results of an investigation that aimed to assess textual coherence automatically, using the method of Latent Semantic Analysis in the domain formed by police news. For this purpose, a prototype tool was built using only free software, which can be obtained from the Internet. To validate the performance of the prototype, its evaluation was compared with that made by eight human evaluators: four journalists and four spanish’s teachers with graduate studies in linguistics.

  2. El Potencial de las Variables Latentes en Modelos Explicativos del Uso de la Bicicleta

    OpenAIRE

    Fernández Heredia, Álvaro

    2012-01-01

    La necesidad de una movilidad más sostenible en nuestras ciudades hacen que la bicicleta tome cada vez mayor importancia como modo de transporte urbano. A su vez, también aumenta el interés de los investigadores por conocer mejor los factores relacionados con el uso de la bicicleta. Tradicionalmente se ha prestado atención a los factores relacionados con el uso de la bicicleta que son directamente observables, dejando en un segundo plano las percepciones, acti...

  3. Latent HIV in primary T lymphocytes is unresponsive to histone deacetylase inhibitors

    Directory of Open Access Journals (Sweden)

    Sahu Gautam K

    2011-08-01

    Full Text Available Abstract Recently, there is considerable interest in the field of anti-HIV therapy to identify and develop chromatin-modifying histone deacetylase (HDAC inhibitors that can effectively reactivate latent HIV in patients. The hope is that this would help eliminate cells harboring latent HIV and achieve an eventual cure of the virus. However, how effectively these drugs can stimulate latent HIVs in quiescent primary CD4 T cells, despite their relevant potencies demonstrated in cell line models of HIV latency, is not clear. Here, we show that the HDAC inhibitors valproic acid (VPA and trichostatin A (TSA are unable to reactivate HIV in latently infected primary CD4 T cells generated in the H80 co-culture system. This raises a concern that the drugs inhibiting HDAC function alone might not be sufficient for stimulating latent HIV in resting CD4 T cells in patients and not achieve any anticipated reduction in the pool of latent reservoirs.

  4. Integrated Evaluation of Latent Viral Reactivation During Spaceflight

    Science.gov (United States)

    Pierson, Duane L.; Paloski, W. H. (Technical Monitor)

    2000-01-01

    This application proposes a continuation of our current effort, which has provided the first demonstration of viral reactivation during space flight. We have used the herpesvirus EBV as a model for latent viral reactivation and have shown that increased amounts of EBV DNA were shed by astronauts during space flight. Analysis of the Antarctic space flight analog indicated that the frequency of viral shedding may also increase (along with the increased numbers of virus) during long periods of isolation. However, a number of critical questions remain before the findings may be considered a significant health risk during extended space flight. These include: Are other latent viruses (e.g., other herpesviruses and polyornaviruses) in addition to EBV also reactivated and shed more frequently and/or in higher numbers during space flight? Is the viral reactivation observed in space flight and ground-based analogs mediated through the hypothalamus-pituitary-adrenal (HPA) axis resulting in a decreased cell-mediated immune response? How does detection of viral DNA by PCR analysis correlate with infectious virus? How does the amount of virus found during flight compare with viral levels observed in acute/chronic viral illnesses and in control individuals? This expanded study will examine the phenomenon of viral reactivation from the initiating stress through the HPA axis with the accompanying suppression of the immune system resulting in viral reactivation. This information is essential to determine if latent viral reactivation among crewmembers represents a sufficient medical risk to space travel to require the development of suitable countermeasures.

  5. From paragraph to graph: latent semantic analysis for information visualization.

    Science.gov (United States)

    Landauer, Thomas K; Laham, Darrell; Derr, Marcia

    2004-04-01

    Most techniques for relating textual information rely on intellectually created links such as author-chosen keywords and titles, authority indexing terms, or bibliographic citations. Similarity of the semantic content of whole documents, rather than just titles, abstracts, or overlap of keywords, offers an attractive alternative. Latent semantic analysis provides an effective dimension reduction method for the purpose that reflects synonymy and the sense of arbitrary word combinations. However, latent semantic analysis correlations with human text-to-text similarity judgments are often empirically highest at approximately 300 dimensions. Thus, two- or three-dimensional visualizations are severely limited in what they can show, and the first and/or second automatically discovered principal component, or any three such for that matter, rarely capture all of the relations that might be of interest. It is our conjecture that linguistic meaning is intrinsically and irreducibly very high dimensional. Thus, some method to explore a high dimensional similarity space is needed. But the 2.7 x 10(7) projections and infinite rotations of, for example, a 300-dimensional pattern are impossible to examine. We suggest, however, that the use of a high dimensional dynamic viewer with an effective projection pursuit routine and user control, coupled with the exquisite abilities of the human visual system to extract information about objects and from moving patterns, can often succeed in discovering multiple revealing views that are missed by current computational algorithms. We show some examples of the use of latent semantic analysis to support such visualizations and offer views on future needs.

  6. Latent cooling and microphysics effects in deep convection

    Science.gov (United States)

    Fernández-González, S.; Wang, P. K.; Gascón, E.; Valero, F.; Sánchez, J. L.

    2016-11-01

    Water phase changes within a storm are responsible for the enhancement of convection and therefore the elongation of its lifespan. Specifically, latent cooling absorbed during evaporation, melting and sublimation is considered the main cause of the intensification of downdrafts. In order to know more accurately the consequences of latent cooling caused by each of these processes (together with microphysical effects that they induce), four simulations were developed with the Wisconsin Dynamical and Microphysical Model (WISCDYMM): one with all the microphysical processes; other without sublimation; melting was suppressed in the third simulation; and evaporation was disabled in the fourth. The results show that sublimation cooling is not essential to maintain the vertical currents of the storm. This is demonstrated by the fact that in the simulation without sublimation, maximum updrafts are in the same range as in the control simulation, and the storm lifespan is similar or even longer. However, melting was of vital importance. The storm in the simulation without melting dissipated prematurely, demonstrating that melting is indispensable to the enhancement of downdrafts below the freezing level and for avoiding the collapse of low level updrafts. Perhaps the most important finding is the crucial influence of evaporative cooling above the freezing level that maintains and enhances mid-level downdrafts in the storm. It is believed that this latent cooling comes from the evaporation of supercooled liquid water connected with the Bergeron-Findeisen process. Therefore, besides its influence at low levels (which was already well known), this evaporative cooling is essential to strengthen mid-level downdrafts and ultimately achieve a quasi-steady state.

  7. Visualization of latent fingerprints using Prussian blue thin films

    Institute of Scientific and Technical Information of China (English)

    Gang Qin; Mei-Qin Zhang; Yang Zhang; Yu Zhu; Shou-Liang Liu; Wen-Jin Wu; Xue-Ji Zhang

    2013-01-01

    Herein,a facile and effective approach was proposed for visualizing latent fingerprints (LFPs) on two kinds of conductive surfaces by spatially selective electrochemical deposition of Prussian blue (PB) thin films.This strategy exploited the fingerprint residue as an insulating mask and the PB thin films were only generated on the bare surface including the valleys between the papillary ridges,which produced a negative image of LFPs with high resolution up to the third level information.The surface morphology of PB films was characterized by the field emission scanning electron microscopy (FE-SEM).This enhancement technique showed promising performance in selected materials of practical interest.

  8. Inhibitory processes in toddlers: a latent-variable approach

    Science.gov (United States)

    Gandolfi, Elena; Viterbori, Paola; Traverso, Laura; Usai, M. Carmen

    2014-01-01

    The aim of this study was to investigate the nature of inhibitory processes in early childhood. A confirmatory factor analysis was used to examine the latent structure of inhibitory processes in day-care center children aged 24–32 months and in preschool children aged 36–48 months. The best fit to the data for the younger sample was a single undifferentiated inhibition factor model; in older children, a two-factor model was differently identified in which response inhibition and interference suppression were distinguished. PMID:24817858

  9. Inhibitory processes in toddlers: A latent-variable approach

    Directory of Open Access Journals (Sweden)

    Elena eGandolfi

    2014-04-01

    Full Text Available The aim of this study was to investigate the nature of inhibitory processes in early childhood. A confirmatory factor analysis was used to examine the latent structure of inhibitory processes in day-care center children aged 24-32 months and in preschool children aged 36-48 months. The best fit to the data for the younger sample was a single undifferentiated inhibition factor model; in older children, a two-factor model was differently identified in which response inhibition and interference suppression were distinguished.

  10. Modeling Individual Subtests of the WAIS IV with Multiple Latent Factors

    OpenAIRE

    2013-01-01

    Performance on a cognitive test can be viewed either as measuring a unitary function or as reflecting the operation of multiple factors. Individual subtests in batteries designed to measure human abilities are commonly modeled as a single latent factor. Several latent factors are then used to model groups of subtests. However these latent factors are not independent as they are related through hierarchical or oblique structures. As a result, the simple structure of subtest performance results...

  11. Effects of swim stress on latent inhibition using a conditioned taste aversion procedure.

    Science.gov (United States)

    Smith, Shawn; Fieser, Sarah; Jones, Jennifer; Schachtman, Todd R

    2008-10-20

    Rats were used to examine the effects of inescapable swim stress on latent inhibition using a conditioned taste aversion procedure. Subjects were subjected to inescapable swim after each of three saccharin taste preexposures and saccharin was later paired with LiCl. The ability of swim to influence latent inhibition was assessed on subsequent saccharin test trials. Swim stress significantly attenuated latent inhibition. The implications of these results regarding the effects of swim stress on conditioned taste aversion are discussed.

  12. Association between latent toxoplasmosis and cognition in adults: a cross-sectional study.

    Science.gov (United States)

    Gale, S D; Brown, B L; Erickson, L D; Berrett, A; Hedges, D W

    2015-04-01

    Latent infection from Toxoplasma gondii (T. gondii) is widespread worldwide and has been associated with cognitive deficits in some but not all animal models and in humans. We tested the hypothesis that latent toxoplasmosis is associated with decreased cognitive function in a large cross-sectional dataset, the National Health and Nutrition Examination Survey (NHANES). There were 4178 participants aged 20-59 years, of whom 19.1% had IgG antibodies against T. gondii. Two ordinary least squares (OLS) regression models adjusted for the NHANES complex sampling design and weighted to represent the US population were estimated for simple reaction time, processing speed and short-term memory or attention. The first model included only main effects of latent toxoplasmosis and demographic control variables, and the second added interaction terms between latent toxoplasmosis and the poverty-to-income ratio (PIR), educational attainment and race-ethnicity. We also used multivariate models to assess all three cognitive outcomes in the same model. Although the models evaluating main effects only demonstrated no association between latent toxoplasmosis and the cognitive outcomes, significant interactions between latent toxoplasmosis and the PIR, between latent toxoplasmosis and educational attainment, and between latent toxoplasmosis and race-ethnicity indicated that latent toxoplasmosis may adversely affect cognitive function in certain groups.

  13. Bayesian latent structure modeling of walking behavior in a physical activity intervention

    Science.gov (United States)

    Lawson, Andrew B; Ellerbe, Caitlyn; Carroll, Rachel; Alia, Kassandra; Coulon, Sandra; Wilson, Dawn K; VanHorn, M Lee; St George, Sara M

    2017-01-01

    The analysis of walking behavior in a physical activity intervention is considered. A Bayesian latent structure modeling approach is proposed whereby the ability and willingness of participants is modeled via latent effects. The dropout process is jointly modeled via a linked survival model. Computational issues are addressed via posterior sampling and a simulated evaluation of the longitudinal model’s ability to recover latent structure and predictor effects is considered. We evaluate the effect of a variety of socio-psychological and spatial neighborhood predictors on the propensity to walk and the estimation of latent ability and willingness in the full study. PMID:24741000

  14. Peculiarities of latent inhibition formation in SHR rats in conditioned task of different complexity.

    Science.gov (United States)

    Kostyunina, N V; Loskutova, L V

    2012-05-01

    Inhibition of attention to irrelevant stimuli was studied in SHR rats using latent inhibition test. Latent inhibition was formed in two types of conditioned tasks with different levels of complexity and stress. Passive and active avoidance conditioning was preceded by preexposure to conditioned stimulus consisting of 20 and 100 non-reinforced presentations, respectively. Control Wistar rats demonstrated successful formation of latent inhibition in both tasks. SHR rats showed different degree of disruption of latent inhibition depending on the type of behavioral task. We assume that learning defect in these animals in respect to both novel and preexposed conditioned stimuli is associated with the lack of behavioral inhibition.

  15. Additional exposures to a compound of two preexposed stimuli deepen latent inhibition.

    Science.gov (United States)

    Leung, Hiu Tin; Killcross, A S; Westbrook, R Frederick

    2011-10-01

    The present experiments studied the role of error correction mechanisms in the latent inhibition of conditioned fear responses by conditioned stimulus (CS) preexposure. They demonstrated that a preexposed CS subjected to additional exposures in compound with either another preexposed stimulus or a novel stimulus was more latently inhibited than a preexposed CS which received additional exposures in isolation. They also showed that a preexposed CS subjected to additional exposures in compound with another preexposed stimulus was more latently inhibited than a preexposed CS given additional exposures in compound with a novel stimulus. These results were discussed in terms of the Hall-Rodriguez (2010) model of latent inhibition.

  16. Missing Modality Transfer Learning via Latent Low-Rank Constraint.

    Science.gov (United States)

    Ding, Zhengming; Shao, Ming; Fu, Yun

    2015-11-01

    Transfer learning is usually exploited to leverage previously well-learned source domain for evaluating the unknown target domain; however, it may fail if no target data are available in the training stage. This problem arises when the data are multi-modal. For example, the target domain is in one modality, while the source domain is in another. To overcome this, we first borrow an auxiliary database with complete modalities, then consider knowledge transfer across databases and across modalities within databases simultaneously in a unified framework. The contributions are threefold: 1) a latent factor is introduced to uncover the underlying structure of the missing modality from the known data; 2) transfer learning in two directions allows the data alignment between both modalities and databases, giving rise to a very promising recovery; and 3) an efficient solution with theoretical guarantees to the proposed latent low-rank transfer learning algorithm. Comprehensive experiments on multi-modal knowledge transfer with missing target modality verify that our method can successfully inherit knowledge from both auxiliary database and source modality, and therefore significantly improve the recognition performance even when test modality is inaccessible in the training stage.

  17. The Latent Curriculum: Breaking Conceptual Barriers to Information Architecture

    Directory of Open Access Journals (Sweden)

    Catherine Boden

    2012-05-01

    Full Text Available In online instruction there is a physical and temporal distance between students and instructors that is not present in face-to-face instruction, which has implications for developing online curricula. This paper examines information literacy components of Introduction to Systematic Reviews, an online graduate-level course offered at the University of Saskatchewan. Course evaluation suggested that, although the screencast tutorials were well accepted by the students as a method of learning, there was need to enhance their content. Through grading of assignments, consultations with the students, and evaluation of the final search strategies, the authors identified common aspects of search strategy development with which the students struggled throughout the course. There was a need to unpack the curriculum to more clearly identify specific areas that needed to be expanded or improved. Bloom’s Revised Taxonomy was utilized as the construct to identify information literacy learning objectives at a relatively granular level. Comparison of learning objectives and the content of the screencast tutorials revealed disparities between desired outcomes and the curriculum (particularly for high-level thinking – the latent curriculum. Analyzing curricula using a tool like Bloom’s Revised Taxonomy will help information literacy librarians recognize hidden or latent learning objectives.

  18. A review of murine models of latent tuberculosis infection.

    Science.gov (United States)

    Shi, Changhong; Shi, Jieran; Xu, Zhikai

    2011-12-01

    The mechanisms of latency and the causes of reactivation of Mycobacterium tuberculosis remain poorly understood; an important reason for this gap in knowledge is the absence of a standardized animal model of latent tuberculosis infection (LTBI). A complete LTBI model should incorporate 2 aspects of LTBI: a persistent infection model with a low bacterial load and a latent infection model that is modified from the Cornell model. Many parameters must be carefully considered to establish an LTBI model, including the inoculating dose, the route of infection, the time interval between infection and the initiation of antibiotic therapy, and the genetic background of the host animal. The responsiveness of this mouse model of LTBI can be assessed through the integrated use of indices, including Karnofsky performance status, bacterial load in spleen and lungs, induced levels of interferon-gamma and tumour necrosis factor-alpha, expression of interleukin (IL)-10 and IL-4 in tissues, specific antigen load in organs, time required for hormone-induced TB relapse, expression level of dormancy genes, and CD4 T-cell count.

  19. Investigation of Latent Traces Using Infrared Reflectance Hyperspectral Imaging

    Science.gov (United States)

    Schubert, Till; Wenzel, Susanne; Roscher, Ribana; Stachniss, Cyrill

    2016-06-01

    The detection of traces is a main task of forensics. Hyperspectral imaging is a potential method from which we expect to capture more fluorescence effects than with common forensic light sources. This paper shows that the use of hyperspectral imaging is suited for the analysis of latent traces and extends the classical concept to the conservation of the crime scene for retrospective laboratory analysis. We examine specimen of blood, semen and saliva traces in several dilution steps, prepared on cardboard substrate. As our key result we successfully make latent traces visible up to dilution factor of 1:8000. We can attribute most of the detectability to interference of electromagnetic light with the water content of the traces in the shortwave infrared region of the spectrum. In a classification task we use several dimensionality reduction methods (PCA and LDA) in combination with a Maximum Likelihood classifier, assuming normally distributed data. Further, we use Random Forest as a competitive approach. The classifiers retrieve the exact positions of labelled trace preparation up to highest dilution and determine posterior probabilities. By modelling the classification task with a Markov Random Field we are able to integrate prior information about the spatial relation of neighboured pixel labels.

  20. Analyzing large-scale proteomics projects with latent semantic indexing.

    Science.gov (United States)

    Klie, Sebastian; Martens, Lennart; Vizcaíno, Juan Antonio; Côté, Richard; Jones, Phil; Apweiler, Rolf; Hinneburg, Alexander; Hermjakob, Henning

    2008-01-01

    Since the advent of public data repositories for proteomics data, readily accessible results from high-throughput experiments have been accumulating steadily. Several large-scale projects in particular have contributed substantially to the amount of identifications available to the community. Despite the considerable body of information amassed, very few successful analyses have been performed and published on this data, leveling off the ultimate value of these projects far below their potential. A prominent reason published proteomics data is seldom reanalyzed lies in the heterogeneous nature of the original sample collection and the subsequent data recording and processing. To illustrate that at least part of this heterogeneity can be compensated for, we here apply a latent semantic analysis to the data contributed by the Human Proteome Organization's Plasma Proteome Project (HUPO PPP). Interestingly, despite the broad spectrum of instruments and methodologies applied in the HUPO PPP, our analysis reveals several obvious patterns that can be used to formulate concrete recommendations for optimizing proteomics project planning as well as the choice of technologies used in future experiments. It is clear from these results that the analysis of large bodies of publicly available proteomics data by noise-tolerant algorithms such as the latent semantic analysis holds great promise and is currently underexploited.

  1. Development of Fraction Comparison Strategies: A Latent Transition Analysis.

    Science.gov (United States)

    Rinne, Luke F; Ye, Ai; Jordan, Nancy C

    2017-02-20

    The present study investigated the development of fraction comparison strategies through a longitudinal analysis of children's responses to a fraction comparison task in 4th through 6th grades (N = 394). Participants were asked to choose the larger value for 24 fraction pairs blocked by fraction type. Latent class analysis of performance over item blocks showed that most children initially exhibited a "whole number bias," indicating that larger numbers in numerators and denominators produce larger fraction values. However, some children instead chose fractions with smaller numerators and denominators, demonstrating a partial understanding that smaller numbers can yield larger fractions. Latent transition analysis showed that most children eventually adopted normative comparison strategies. Children who exhibited a partial understanding by choosing fractions with smaller numbers were more likely to adopt normative comparison strategies earlier than those with larger number biases. Controlling for general math achievement and other cognitive abilities, whole number line estimation accuracy predicted the probability of transitioning to normative comparison strategies. Exploratory factor analyses showed that over time, children appeared to increasingly represent fractions as discrete magnitudes when simpler strategies were unavailable. These results support the integrated theory of numerical development, which posits that an understanding of numbers as magnitudes unifies the process of learning whole numbers and fractions. The findings contrast with conceptual change theories, which propose that children must move from a view of numbers as counting units to a new view that accommodates fractions to overcome whole number bias. (PsycINFO Database Record

  2. A Probabilistic Recommendation Method Inspired by Latent Dirichlet Allocation Model

    Directory of Open Access Journals (Sweden)

    WenBo Xie

    2014-01-01

    Full Text Available The recent decade has witnessed an increasing popularity of recommendation systems, which help users acquire relevant knowledge, commodities, and services from an overwhelming information ocean on the Internet. Latent Dirichlet Allocation (LDA, originally presented as a graphical model for text topic discovery, now has found its application in many other disciplines. In this paper, we propose an LDA-inspired probabilistic recommendation method by taking the user-item collecting behavior as a two-step process: every user first becomes a member of one latent user-group at a certain probability and each user-group will then collect various items with different probabilities. Gibbs sampling is employed to approximate all the probabilities in the two-step process. The experiment results on three real-world data sets MovieLens, Netflix, and Last.fm show that our method exhibits a competitive performance on precision, coverage, and diversity in comparison with the other four typical recommendation methods. Moreover, we present an approximate strategy to reduce the computing complexity of our method with a slight degradation of the performance.

  3. Screening for latent tuberculosis in refugees with renal failure

    Directory of Open Access Journals (Sweden)

    Ghanshyam Palamaner Subash Shantha

    2012-01-01

    Full Text Available Refugee camps are prone for easy spread of infections of various kinds and tuberculosis (TB is no exception. Refugees with renal failure are often a vulnerable group because they are immunocompromised due to reasons such as poor nutrition, overcrowding and immune suppression due to renal failure. Latent pulmonary TB is a particular problem in this patient population as it is not easily diagnosed and has immense potential for spread. Tuberculin Skin Test (TST, although easy to perform and is cost-effective, suffers from the limitations of giving false positive results due to cross-reaction with the vaccination. Chest radiography though cheap, has not yet been validated in refugee populations for this purpose. Sputum analysis shows promise due to ease of performing but again has not been validated in refugees. Newer assays such as IF-γ show great promise but needs large scale studies for validation and cheaper assays need to be developed for use in resource poor refugee setting. In short, an ideal tool for effective screening of latent TB in refugees with renal failure is lacking. Future studies are required to identify this ideal tool.

  4. Latent log-linear models for handwritten digit classification.

    Science.gov (United States)

    Deselaers, Thomas; Gass, Tobias; Heigold, Georg; Ney, Hermann

    2012-06-01

    We present latent log-linear models, an extension of log-linear models incorporating latent variables, and we propose two applications thereof: log-linear mixture models and image deformation-aware log-linear models. The resulting models are fully discriminative, can be trained efficiently, and the model complexity can be controlled. Log-linear mixture models offer additional flexibility within the log-linear modeling framework. Unlike previous approaches, the image deformation-aware model directly considers image deformations and allows for a discriminative training of the deformation parameters. Both are trained using alternating optimization. For certain variants, convergence to a stationary point is guaranteed and, in practice, even variants without this guarantee converge and find models that perform well. We tune the methods on the USPS data set and evaluate on the MNIST data set, demonstrating the generalization capabilities of our proposed models. Our models, although using significantly fewer parameters, are able to obtain competitive results with models proposed in the literature.

  5. Surface latent heat flux as an earthquake precursor

    Directory of Open Access Journals (Sweden)

    S. Dey

    2003-01-01

    Full Text Available The analysis of surface latent heat flux (SLHF from the epicentral regions of five recent earthquakes that occurred in close proximity to the oceans has been found to show anomalous behavior. The maximum increase of SLHF is found 2–7 days prior to the main earthquake event. This increase is likely due to an ocean-land-atmosphere interaction. The increase of SLHF prior to the main earthquake event is attributed to the increase in infrared thermal (IR temperature in the epicentral and surrounding region. The anomalous increase in SLHF shows great potential in providing early warning of a disastrous earthquake, provided that there is a better understanding of the background noise due to the tides and monsoon in surface latent heat flux. Efforts have been made to understand the level of background noise in the epicentral regions of the five earthquakes considered in the present paper. A comparison of SLHF from the epicentral regions over the coastal earthquakes and the earthquakes that occurred far away from the coast has been made and it has been found that the anomalous behavior of SLHF prior to the main earthquake event is only associated with the coastal earthquakes.

  6. Potencial del Agua del suelo

    Directory of Open Access Journals (Sweden)

    Bustamante Heliodoro

    1986-12-01

    Full Text Available La energía potencial del agua presenta diferencias de un punto del suelo a otro; esas diferencias son las que originan el movimiento del agua de acuerdo a la tendencia universal de la materia en el sentido de moverse de donde la energía potencial es mayor a donde dicha energía es menor. En el suelo el agua en consecuencia se mueve hacia donde su energía decrece hasta lograr su estado de equilibrio. Se desprende entonces que la cantidad de energía potencial absoluta contenida en el agua, no es importante por sí misma, sino por su relación con la energía en diferentes lugares dentro del suelo. El concepto Potencial de agua del suelo es un criterio para esta energía.

  7. Proliferation of latently infected CD4+ T cells carrying replication-competent HIV-1: Potential role in latent reservoir dynamics

    Science.gov (United States)

    Hosmane, Nina N.; Kwon, Kyungyoon J.; Bruner, Katherine M.; Capoferri, Adam A.; Rosenbloom, Daniel I.S.; Keele, Brandon F.; Ho, Ya-Chi

    2017-01-01

    A latent reservoir for HIV-1 in resting CD4+ T lymphocytes precludes cure. Mechanisms underlying reservoir stability are unclear. Recent studies suggest an unexpected degree of infected cell proliferation in vivo. T cell activation drives proliferation but also reverses latency, resulting in productive infection that generally leads to cell death. In this study, we show that latently infected cells can proliferate in response to mitogens without producing virus, generating progeny cells that can release infectious virus. Thus, assays relying on one round of activation underestimate reservoir size. Sequencing of independent clonal isolates of replication-competent virus revealed that 57% had env sequences identical to other isolates from the same patient. Identity was confirmed by full-genome sequencing and was not attributable to limited viral diversity. Phylogenetic and statistical analysis suggested that identical sequences arose from in vivo proliferation of infected cells, rather than infection of multiple cells by a dominant viral species. The possibility that much of the reservoir arises by cell proliferation presents challenges to cure. PMID:28341641

  8. Analyzing Latent State-Trait and Multiple-Indicator Latent Growth Curve Models as Multilevel Structural Equation Models

    Directory of Open Access Journals (Sweden)

    Christian eGeiser

    2013-12-01

    Full Text Available Latent state-trait (LST and latent growth curve (LGC models are frequently used in the analysis of longitudinal data. Although it is well-known that standard single-indicator LGC models can be analyzed within either the structural equation modeling (SEM or multilevel (ML; hierarchical linear modeling frameworks, few researchers realize that LST and multivariate LGC models, which use multiple indicators at each time point, can also be specified as ML models. In the present paper, we demonstrate that using the ML-SEM rather than the SL-SEM framework to estimate the parameters of these models can be practical when the study involves (1 a large number of time points, (2 individually-varying times of observation, (3 unequally spaced time intervals, and/or (4 incomplete data. Despite the practical advantages of the ML-SEM approach under these circumstances, there are also some limitations that researchers should consider. We present an application to an ecological momentary assessment study (N = 158 youths with an average of 23.49 observations of positive mood per person using the software Mplus (Muthén & Muthén, 1998-2012 and discuss advantages and disadvantages of using the ML-SEM approach to estimate the parameters of LST and multiple-indicator LGC models.

  9. Potencial del agua del suelo

    OpenAIRE

    Bustamante Heliodoro

    2012-01-01

    La energía potencial del agua presenta diferencias de un punto del suelo a otro; esas diferencias son las que originan el movimiento del agua de acuerdo a la tendencia universal de la materia en el sentido de moverse de donde la energía potencial es mayor a donde dicha energía es menor. En el suelo el agua en consecuencia se mueve hacia donde su energía decrece hasta lograr su estado de equilibrio. Se desprende entonces que la cantidad de energía potencial absoluta contenida en el agua, no es...

  10. Incidence of Latent Virus Shedding during Space Flight

    Science.gov (United States)

    Mehta, Satish K.; Cohrs, Randall J.; Gilden, Donald H.; Tyring, Stephen K.; Ott, C. Mark; Pierson, Duane L.

    2008-01-01

    Measurements of immune parameters of both cellular and innate immunity indicate alterations in immune function in astronauts. Immune changes are due to stress and perhaps other factors associated with launch, flight, and landing phases. Medical relevance of observed changes is not known. The reactivation of latent viruses has been identified as an important in vivo indicator of clinically relevant immune changes. The polymerase chain reaction (PCR) was used to detect the presence of specific viral DNA in body fluids. Initial studies demonstrated Epstein-Barr virus (EBV) reactivation during all 3 mission phases. EBV is shed in saliva following reactivation from B-cells. Incidence of EBV in saliva was higher than control subjects during all 3 mission phases. However, quantitative PCR revealed 10-fold higher levels of EBV DNA present in saliva collected during flight than found in pre- and post flight specimens. To determine if other latent viruses showed similar effects, cytomegalovirus (CMV), another herpes virus, shed in urine following reactivation was studied. A very low incidence (less than 2%) of CMV in urine is found in healthy, lowstressed individuals. However, 25-50% of astronauts shed CMV in their urine before, during, or after flight. Our studies are now focused on varicella-zoster virus (VZV), the etiological agent of chicken-pox during childhood and shingles later in life. We demonstrated reactivation of VZV and shedding of the virus during and after spaceflight in saliva of astronauts with no sign of active infection or symptoms. The maximum shedding of VZV occurred during the flight phase and diminishes rapidly during the first five days after landing. We have utilized the same PCR assay for VZV in a clinical study of shingles patients. Generally, shingles patients shed much more VZV in saliva than astronauts. However, the VZV levels in astronauts overlap with the lower range of VZV numbers in shingles patients. Saliva from shingles patients and

  11. Sensible and latent heating of the atmosphere as inferred from DST-6 data

    Science.gov (United States)

    Herman, G. F.; Schubert, S. D.; Johnson, W. T.

    1979-01-01

    The average distribution of convective latent heating, boundary layer sensible heat flux, and vertical velocity are determined for the winter 1976 DST period from GLAS model diagnostics. Key features are the regions of intense latent heating over Brazil, Central Africa, and Indonesia; and the regions of strong sensible heating due to air mass modification over the North Atlantic and North Pacific Oceans.

  12. A Herpesviral Lytic Protein Regulates the Structure of Latent Viral Chromatin

    Directory of Open Access Journals (Sweden)

    Priya Raja

    2016-05-01

    Full Text Available Latent infections by viruses usually involve minimizing viral protein expression so that the host immune system cannot recognize the infected cell through the viral peptides presented on its cell surface. Herpes simplex virus (HSV, for example, is thought to express noncoding RNAs such as latency-associated transcripts (LATs and microRNAs (miRNAs as the only abundant viral gene products during latent infection. Here we describe analysis of HSV-1 mutant viruses, providing strong genetic evidence that HSV-infected cell protein 0 (ICP0 is expressed during establishment and/or maintenance of latent infection in murine sensory neurons in vivo. Studies of an ICP0 nonsense mutant virus showed that ICP0 promotes heterochromatin and latent and lytic transcription, arguing that ICP0 is expressed and functional. We propose that ICP0 promotes transcription of LATs during establishment or maintenance of HSV latent infection, much as it promotes lytic gene transcription. This report introduces the new concept that a lytic viral protein can be expressed during latent infection and can serve dual roles to regulate viral chromatin to optimize latent infection in addition to its role in epigenetic regulation during lytic infection. An additional implication of the results is that ICP0 might serve as a target for an antiviral therapeutic acting on lytic and latent infections.

  13. The Use of Loglinear Models for Assessing Differential Item Functioning Across Manifest and Latent Examinee Groups

    NARCIS (Netherlands)

    Kelderman, Henk; Macready, George B.

    1990-01-01

    Loglinear latent class models are used to detect differential item functioning (DIF). These models are formulated in such a manner that the attribute to be assessed may be continuous, as in a Rasch model, or categorical, as in Latent Class Mastery models. Further, an item may exhibit DIF with respec

  14. Longitudinal Data Analysis with Latent Growth Modeling: An Introduction and Illustration for Higher Education Researchers

    Science.gov (United States)

    Blanchard, Rebecca D.; Konold, Timothy R.

    2011-01-01

    This paper introduces latent growth modeling (LGM) as a statistical method for analyzing change over time in latent, or unobserved, variables, with particular emphasis of the application of this method in higher education research. While increasingly popular in other areas of education research and despite a wealth of publicly-available datasets…

  15. Planned missing designs to optimize the efficiency of latent growth parameter estimates

    NARCIS (Netherlands)

    Rhemtulla, M.; Jia, F.; Wu, W.; Little, T.D.

    2014-01-01

    We examine the performance of planned missing (PM) designs for correlated latent growth curve models. Using simulated data from a model where latent growth curves are fitted to two constructs over five time points, we apply three kinds of planned missingness. The first is item-level planned missingn

  16. A Taxonomy of Latent Structure Assumptions for Probability Matrix Decomposition Models.

    Science.gov (United States)

    Meulders, Michel; De Boeck, Paul; Van Mechelen, Iven

    2003-01-01

    Proposed a taxonomy of latent structure assumptions for probability matrix decomposition (PMD) that includes the original PMD model and a three-way extension of the multiple classification latent class model. Simulation study results show the usefulness of the taxonomy. (SLD)

  17. Visualizing Confidence Bands for Semiparametrically Estimated Nonlinear Relations among Latent Variables

    Science.gov (United States)

    Pek, Jolynn; Chalmers, R. Philip; Kok, Bethany E.; Losardo, Diane

    2015-01-01

    Structural equation mixture models (SEMMs), when applied as a semiparametric model (SPM), can adequately recover potentially nonlinear latent relationships without their specification. This SPM is useful for exploratory analysis when the form of the latent regression is unknown. The purpose of this article is to help users familiar with structural…

  18. A Composite Likelihood Inference in Latent Variable Models for Ordinal Longitudinal Responses

    Science.gov (United States)

    Vasdekis, Vassilis G. S.; Cagnone, Silvia; Moustaki, Irini

    2012-01-01

    The paper proposes a composite likelihood estimation approach that uses bivariate instead of multivariate marginal probabilities for ordinal longitudinal responses using a latent variable model. The model considers time-dependent latent variables and item-specific random effects to be accountable for the interdependencies of the multivariate…

  19. Advanced Nonlinear Latent Variable Modeling: Distribution Analytic LMS and QML Estimators of Interaction and Quadratic Effects

    Science.gov (United States)

    Kelava, Augustin; Werner, Christina S.; Schermelleh-Engel, Karin; Moosbrugger, Helfried; Zapf, Dieter; Ma, Yue; Cham, Heining; Aiken, Leona S.; West, Stephen G.

    2011-01-01

    Interaction and quadratic effects in latent variable models have to date only rarely been tested in practice. Traditional product indicator approaches need to create product indicators (e.g., x[superscript 2] [subscript 1], x[subscript 1]x[subscript 4]) to serve as indicators of each nonlinear latent construct. These approaches require the use of…

  20. A Note on Stochastic Ordering of the Latent Trait Using the Sum of Polytomous Item Scores

    Science.gov (United States)

    van der Ark, L. Andries; Bergsma, Wicher P.

    2010-01-01

    In contrast to dichotomous item response theory (IRT) models, most well-known polytomous IRT models do not imply stochastic ordering of the latent trait by the total test score (SOL). This has been thought to make the ordering of respondents on the latent trait using the total test score questionable and throws doubt on the justifiability of using…

  1. Measurement Uncertainty in Racial and Ethnic Identification among Adolescents of Mixed Ancestry: A Latent Variable Approach

    Science.gov (United States)

    Tracy, Allison J.; Erkut, Sumru; Porche, Michelle V.; Kim, Jo; Charmaraman, Linda; Grossman, Jennifer M.; Ceder, Ineke; Garcia, Heidie Vazquez

    2010-01-01

    In this article, we operationalize identification of mixed racial and ethnic ancestry among adolescents as a latent variable to (a) account for measurement uncertainty, and (b) compare alternative wording formats for racial and ethnic self-categorization in surveys. Two latent variable models were fit to multiple mixed-ancestry indicator data from…

  2. A Latent Transition Analysis of Academic Intrinsic Motivation from Childhood through Adolescence

    Science.gov (United States)

    Marcoulides, George A.; Gottfried, Adele Eskeles; Gottfried, Allen W.; Oliver, Pamella H.

    2008-01-01

    A longitudinal modeling approach was utilized to determine the existence of latent classes with regard to academic intrinsic motivation and the points of stability and transition of individuals between and within classes. A special type of latent Markov Chain model using "Mplus" was fit to data from the Fullerton Longitudinal Study, with…

  3. Bayesian Methods for Analyzing Structural Equation Models with Covariates, Interaction, and Quadratic Latent Variables

    Science.gov (United States)

    Lee, Sik-Yum; Song, Xin-Yuan; Tang, Nian-Sheng

    2007-01-01

    The analysis of interaction among latent variables has received much attention. This article introduces a Bayesian approach to analyze a general structural equation model that accommodates the general nonlinear terms of latent variables and covariates. This approach produces a Bayesian estimate that has the same statistical optimal properties as a…

  4. Substantial molecular evolution and mutation rates in prolonged latent Mycobacterium tuberculosis infection in humans

    DEFF Research Database (Denmark)

    Lillebaek, Troels; Norman, Anders; Rasmussen, Erik Michael;

    2016-01-01

    The genome of Mycobacterium tuberculosis (Mtb) of latently infected individuals may hold the key to understanding the processes that lead to reactivation and progression to clinical disease. We report here analysis of pairs of Mtb isolates from putative prolonged latent TB cases. We identified tw...

  5. Latent tuberculosis in HIV positive, diagnosed by the M. tuberculosis specific interferon-gamma test

    DEFF Research Database (Denmark)

    Brock, Inger; Ruhwald, Morten; Lundgren, Bettina

    2006-01-01

    Although tuberculosis (TB) is a minor problem in Denmark, severe and complicated cases occur in HIV positive. Since the new M. tuberculosis specific test for latent TB, the QuantiFERON-TB In-Tube test (QFT-IT) became available the patients in our clinic have been screened for the presence of latent...

  6. Assessment of School Performance through a Multilevel Latent Markov Rasch Model

    Science.gov (United States)

    Bartolucci, Francesco; Pennoni, Fulvia; Vittadini, Giorgio

    2011-01-01

    An extension of the latent Markov Rasch model is described for the analysis of binary longitudinal data with covariates when subjects are collected in clusters, such as students clustered in classes. For each subject, a latent process is used to represent the characteristic of interest (e.g., ability) conditional on the effect of the cluster to…

  7. A Comparison of Latent Growth Models for Constructs Measured by Multiple Items

    Science.gov (United States)

    Leite, Walter L.

    2007-01-01

    Univariate latent growth modeling (LGM) of composites of multiple items (e.g., item means or sums) has been frequently used to analyze the growth of latent constructs. This study evaluated whether LGM of composites yields unbiased parameter estimates, standard errors, chi-square statistics, and adequate fit indexes. Furthermore, LGM was compared…

  8. Substantial molecular evolution and mutation rates in prolonged latent Mycobacterium tuberculosis infection in humans

    DEFF Research Database (Denmark)

    Lillebaek, Troels; Norman, Anders; Rasmussen, Erik Michael;

    2016-01-01

    The genome of Mycobacterium tuberculosis (Mtb) of latently infected individuals may hold the key to understanding the processes that lead to reactivation and progression to clinical disease. We report here analysis of pairs of Mtb isolates from putative prolonged latent TB cases. We identified two...

  9. D-Cycloserine Enhances Memory Consolidation of Hippocampus-Dependent Latent Extinction

    Science.gov (United States)

    Gabriele, Amanda; Packard, Mark G.

    2007-01-01

    Adult male Long-Evans rats were trained to run in a straight-alley maze for food reward and subsequently received hippocampus-dependent latent extinction training. Immediately following latent extinction, rats received peripheral injections of the NMDA receptor partial agonist D-cycloserine (DCS, 15 mg/kg), or saline. Twenty-four hours later, rats…

  10. Detecting Appropriate Trajectories of Growth in Latent Growth Models: The Performance of Information-Based Criteria

    Science.gov (United States)

    Whittaker, Tiffany A.; Khojasteh, Jam

    2017-01-01

    Latent growth modeling (LGM) is a popular and flexible technique that may be used when data are collected across several different measurement occasions. Modeling the appropriate growth trajectory has important implications with respect to the accurate interpretation of parameter estimates of interest in a latent growth model that may impact…

  11. Selection between Linear Factor Models and Latent Profile Models Using Conditional Covariances

    Science.gov (United States)

    Halpin, Peter F.; Maraun, Michael D.

    2010-01-01

    A method for selecting between K-dimensional linear factor models and (K + 1)-class latent profile models is proposed. In particular, it is shown that the conditional covariances of observed variables are constant under factor models but nonlinear functions of the conditioning variable under latent profile models. The performance of a convenient…

  12. Extending dynamic segmentation with lead generation : A latent class Markov analysis of financial product portfolios

    NARCIS (Netherlands)

    Paas, L.J.; Bijmolt, T.H.A.; Vermunt, J.K.

    2004-01-01

    A recent development in marketing research concerns the incorporation of dynamics in consumer segmentation.This paper extends the latent class Markov model, a suitable technique for conducting dynamic segmentation, in order to facilitate lead generation.We demonstrate the application of the latent M

  13. The Biplot as a diagnostic tool of local dependence in latent class models. A medical application.

    Science.gov (United States)

    Sepúlveda, R; Vicente-Villardón, J L; Galindo, M P

    2008-05-20

    Latent class models (LCMs) can be used to assess diagnostic test performance when no reference test (a gold standard) is available, considering two latent classes representing disease or non-disease status. One of the basic assumptions in such models is that of local or conditional independence: all indicator variables (tests) are statistically independent within each latent class. However, in practice this assumption is often violated; hence, the two-LCM fits the data poorly. In this paper, we propose the use of Biplot methods to identify the conditional dependence between pairs of manifest variables within each latent class. Additionally, we propose incorporating such dependence in the corresponding latent class using the log-linear formulation of the model.

  14. DISCOVERY OF LATENT STRUCTURES: EXPERIENCE WITH THE COIL CHALLENGE 2000 DATA SET

    Institute of Scientific and Technical Information of China (English)

    Nevin L. ZHANG; Yi WANG; Tao CHEN

    2008-01-01

    The authors present a case study to demonstrate the possibility of discovering complex and interesting latent structures using hierarchical latent class (HLC) models. A similar effort was made earlier by Zhang (2002), but that study involved only small applications with 4 or 5 observed variables and no more than 2 latent variables due to the lack of efficient learning algorithms. Significant progress has been made since then on algorithmic research, and it is now possible to learn HLC models with dozens of observed variables. This allows us to demonstrate the benefits of HLC models more convincingly than before. The authors have successfully analyzed the CoIL Challenge 2000 data set using HLC models. The model obtained consists of 22 latent variables, and its structure is intuitively appealing. It is exciting to know that such a large and meaningful latent structure can be automatically inferred from data.

  15. Social Stress and the Reactivation of Latent Herpes Simplex Virus Type 1

    Science.gov (United States)

    Padgett, David A.; Sheridan, John F.; Dorne, Julianne; Berntson, Gary G.; Candelora, Jessica; Glaser, Ronald

    1998-06-01

    Psychological stress is thought to contribute to reactivation of latent herpes simplex virus (HSV). Although several animal models have been developed in an effort to reproduce different pathogenic aspects of HSV keratitis or labialis, until now, no good animal model existed in which application of a psychological laboratory stressor results in reliable reactivation of the virus. Reported herein, disruption of the social hierarchy within colonies of mice increased aggression among cohorts, activated the hypothalamic-pituitary-adrenal axis, and caused reactivation of latent HSV type 1 in greater than 40% of latently infected animals. However, activation of the hypothalamic-pituitary-adrenal axis using restraint stress did not activate the latent virus. Thus, the use of social stress in mice provides a good model in which to investigate the neuroendocrine mechanisms that underlie behaviorally mediated reactivation of latent herpes-viruses.

  16. Harry Potter and the sorcerer's scope: latent scope biases in explanatory reasoning.

    Science.gov (United States)

    Khemlani, Sangeet S; Sussman, Abigail B; Oppenheimer, Daniel M

    2011-04-01

    What makes a good explanation? We examine the function of latent scope, i.e., the number of unobserved phenomena that an explanation can account for. We show that individuals prefer narrow latent scope explanations-those that account for fewer unobserved effects-to broader explanations. In Experiments 1a-d, participants found narrow latent scope explanations to be both more satisfying and more likely. In Experiment 2 we directly manipulated base rate information and again found a preference for narrow latent scope explanations. Participants in Experiment 3 evaluated more natural explanations of unexpected observations, and again displayed a bias for narrow latent scope explanations. We conclude by considering what this novel bias tells us about how humans evaluate explanations and engage in causal reasoning.

  17. Disruption of latent inhibition by interpolation of task-irrelevant stimulation between preexposure and conditioning.

    Science.gov (United States)

    Escobar, Martha; Arcediano, Francisco; Miller, Ralph R

    2005-08-01

    Latent inhibition refers to attenuated responding to a conditioned stimulus (CS) that was repeatedly presented without reinforcement prior to the CS-unconditioned stimulus (US) pairings. Using water-deprived rats as subjects, we observed that interpolating task-irrelevant stimulation between the preexposure and conditioning phases of a latent inhibition procedure attenuated latent inhibition (Experiments 1A, 1B, and 2). Apparently, interpolated stimulation segments the preexposure and conditioning treatments into two separate experiences, much in the same way that a change of context would. Consistent with this view, the interpolated stimulation did not disrupt latent inhibition if it was also presented during both preexposure and conditioning (Experiment 3). We view these results as analogous to those of Escobar, Arcediano, and Miller (2003), who suggested that the difficulty in observing latent inhibition in human adults is related to the segmentation between preexposure and conditioning caused by the usual interpolation of instructions in preparations with humans.

  18. Spread of Infectious Diseases with a Latent Period

    CERN Document Server

    Mizuno, Kanako

    2015-01-01

    Infectious diseases spread through human networks. Susceptible-Infected-Removed (SIR) model is one of the epidemic models to describe infection dynamics on a complex network connecting individuals. In the metapopulation SIR model, each node represents a population (group) which has many individuals. In this paper, we propose a modified metapopulation SIR model in which a latent period is taken into account. We call it SIIR model. We divide the infection period into two stages: an infected stage, which is the same as the previous model, and a seriously ill stage, in which individuals are infected and cannot move to the other populations. The two infectious stages in our modified metapopulation SIR model produce a discontinuous final size distribution. Individuals in the infected stage spread the disease like individuals in the seriously ill stage and never recover directly, which makes an effective recovery rate smaller than the given recovery rate.

  19. Improving knowledge management systems with latent semantic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sebok, A.; Plott, C. [Alion Science and Technology, MA and D Operation, 4949 Pearl East Circle, Boulder, CO 80301 (United States); LaVoie, N. [Pearson Knowledge Technologies, 4940 Pearl East Circle, Boulder, CO 80301 (United States)

    2006-07-01

    Latent Semantic Analysis (LSA) offers a technique for improving lessons learned and knowledge management systems. These systems are expected to become more widely used in the nuclear industry, as experienced personnel leave and are replaced by younger, less-experienced workers. LSA is a machine learning technology that allows searching of text based on meaning rather than predefined keywords or categories. Users can enter and retrieve data using their own words, rather than relying on constrained language lists or navigating an artificially structured database. LSA-based tools can greatly enhance the usability and usefulness of knowledge management systems and thus provide a valuable tool to assist nuclear industry personnel in gathering and transferring worker expertise. (authors)

  20. Development of Latent Heat Storage Phase Change Material Containing Plaster

    Directory of Open Access Journals (Sweden)

    Diana BAJARE

    2016-05-01

    Full Text Available This paper reviews the development of latent heat storage Phase Change Material (PCM containing plaster as in passive application. Due to the phase change, these materials can store higher amounts of thermal energy than traditional building materials and can be used to add thermal inertia to lightweight constructions. It was shown that the use of PCMs have advantages stabilizing the room temperature variations during summer days, provided sufficient night ventilation is allowed. Another advantage of PCM usage is stabilized indoor temperature on the heating season. The goal of this study is to develop cement and lime based plaster containing microencapsulated PCM. The plaster is expected to be used for passive indoor applications and enhance the thermal properties of building envelope. The plaster was investigated under Scanning Electron Microscope and the mechanical, physical and thermal properties of created plaster samples were determined.

  1. A calibration test for latent fingerprint development on thermal paper.

    Science.gov (United States)

    Spencer, Caroline A; Bond, John W

    2014-11-01

    A calibration test is described for monitoring the operation of equipment used to develop latent fingerprints on thermal paper by the application of either controlled or uncontrolled heat. A working solution of a water/glycerol emulsion and butylene glycol is applied to thermal paper by means of either a vinyl stamp and pad, or a marker pen. Varying the amount of butylene glycol enables the thermal paper to change color at different temperatures between approximately 40 and 60°C, which is below the normal color change temperature of the paper. The described test may be used to verify the correct operation, at different temperatures, of a controlled heat source during and after fingerprint development (such as the Hot Print System) or to monitor the paper temperature with an uncontrolled heat source (such as a warm air blower), thereby avoiding unintentional coloring of the entire paper surface.

  2. Monocyte Signal Transduction Receptors in Active and Latent Tuberculosis

    Directory of Open Access Journals (Sweden)

    Magdalena Druszczynska

    2013-01-01

    Full Text Available The mechanisms that promote either resistance or susceptibility to TB disease remain insufficiently understood. Our aim was to compare the expression of cell signaling transduction receptors, CD14, TLR2, CD206, and β2 integrin LFA-1 on monocytes from patients with active TB or nonmycobacterial lung disease and healthy individuals with M.tb latency and uninfected controls to explain the background of the differences between clinical and subclinical forms of M.tb infection. A simultaneous increase in the expression of the membrane bound mCD14 receptor and LFA-1 integrin in patients with active TB may be considered a prodrome of breaking immune control by M.tb bacilli in subjects with the latent TB and absence of clinical symptoms.

  3. Latent semantic analysis: a new method to measure prose recall.

    Science.gov (United States)

    Dunn, John C; Almeida, Osvaldo P; Barclay, Lee; Waterreus, Anna; Flicker, Leon

    2002-02-01

    The aim of this study was to compare traditional methods of scoring the Logical Memory test of the Wechsler Memory Scale-III with a new method based on Latent Semantic Analysis (LSA). LSA represents texts as vectors in a high-dimensional semantic space and the similarity of any two texts is measured by the cosine of the angle between their respective vectors. The Logical Memory test was administered to a sample of 72 elderly individuals, 14 of whom were classified as cognitively impaired by the Mini-Mental State Examination (MMSE). The results showed that LSA was at least as valid and sensitive as traditional measures. Partial correlations between prose recall measures and measures of cognitive function indicated that LSA explained all the relationship between Logical Memory and general cognitive function. This suggests that LSA may serve as an improved measure of prose recall.

  4. Etchability of Latent Fission Fragment Tracks in CR-39

    Institute of Scientific and Technical Information of China (English)

    Mukhtar Ahmed Rana

    2007-01-01

    We report the chemical etching behaviour of the CR-39 polymer detector exposed to fission fragments of 252 Cf describing etchability of latent tracks, which are like nanocylinders. The fission fragment exposed detectors were etched in 1-7N NaOH water solutions at temperatures 50-80°C for 45 min in the case of track length and 180min in the case of track diameter measurements. The reduced etch rate S (called here etchability) is determined using experimental results for all etching conditions and the etching conditions with the highest reduced etch are obtained. Physics and energetics of bulk and track etching are discussed. Possible effects causing spurious changes in determination of activation energy of etching are investigated.

  5. Broad activation of latent HIV-1 in vivo

    DEFF Research Database (Denmark)

    Barton, Kirston; Hiener, Bonnie; Winckelmann, Anni;

    2016-01-01

    The 'shock and kill' approach to cure human immunodeficiency virus (HIV) includes transcriptional induction of latent HIV-1 proviruses using latency-reversing agents (LRAs) with targeted immunotherapy to purge infected cells. The administration of LRAs (panobinostat or vorinostat) to HIV-1-infected...... individuals on antiretroviral therapy induces a significant increase in cell-associated unspliced (CA-US) HIV-1 RNA from CD4(+) T cells. However, it is important to discern whether the increases in CA-US HIV-1 RNA are due to limited or broad activation of HIV-1 proviruses. Here we use single-genome sequencing...... to find that the RNA transcripts observed following LRA administration are genetically diverse, indicating activation of transcription from an extensive range of proviruses. Defective sequences are more frequently found in CA HIV-1 RNA than in HIV-1 DNA, which has implications for developing an accurate...

  6. The latent heat of vaporization of supercritical fluids

    Science.gov (United States)

    Banuti, Daniel; Raju, Muralikrishna; Hickey, Jean-Pierre; Ihme, Matthias

    2016-11-01

    The enthalpy of vaporization is the energy required to overcome intermolecular attractive forces and to expand the fluid volume against the ambient pressure when transforming a liquid into a gas. It diminishes for rising pressure until it vanishes at the critical point. Counterintuitively, we show that a latent heat is in fact also required to heat a supercritical fluid from a liquid to a gaseous state. Unlike its subcritical counterpart, the supercritical pseudoboiling transition is spread over a finite temperature range. Thus, in addition to overcoming intermolecular attractive forces, added energy simultaneously heats the fluid. Then, considering a transition from a liquid to an ideal gas state, we demonstrate that the required enthalpy is invariant to changes in pressure for 0 intermolecular forces in the real fluid vapor during heating. At supercritical pressures, all of the transition occurs at non-equilibrium; for p -> 0 , all of the transition occurs at equilibrium.

  7. Restoring Latent Visual Working Memory Representations in Human Cortex.

    Science.gov (United States)

    Sprague, Thomas C; Ester, Edward F; Serences, John T

    2016-08-03

    Working memory (WM) enables the storage and manipulation of limited amounts of information over short periods. Prominent models posit that increasing the number of remembered items decreases the spiking activity dedicated to each item via mutual inhibition, which irreparably degrades the fidelity of each item's representation. We tested these models by determining if degraded memory representations could be recovered following a post-cue indicating which of several items in spatial WM would be recalled. Using an fMRI-based image reconstruction technique, we identified impaired behavioral performance and degraded mnemonic representations with elevated memory load. However, in several cortical regions, degraded mnemonic representations recovered substantially following a post-cue, and this recovery tracked behavioral performance. These results challenge pure spike-based models of WM and suggest that remembered items are additionally encoded within latent or hidden neural codes that can help reinvigorate active WM representations.

  8. Determining of migraine prognosis using latent growth mixture models

    Institute of Scientific and Technical Information of China (English)

    Bahar Tasdelen; Aynur Ozge; Hakan Kaleagasi; Semra Erdogan; Tufan Mengi

    2011-01-01

    Background This paper presents a retrospective study to classify patients into subtypes of the treatment according to baseline and longitudinally observed values considering heterogenity in migraine prognosis. In the classical prospective clinical studies,participants are classified with respect to baseline status and followed within a certain time period.However,latent growth mixture model is the most suitable method,which considers the population heterogenity and is not affected drop-outs if they are missing at random. Hence,we planned this comprehensive study to identify prognostic factors in migraine.Methods The study data have been based on a 10-year computer-based follow-up data of Mersin University Headache Outpatient Department. The developmental trajectories within subgroups were described for the severity,frequency,and duration of headache separately and the probabilities of each subgroup were estimated by using latent growth mixture models. SAS PROC TRAJ procedures,semiparametric and group-based mixture modeling approach,were applied to define the developmental trajectories.Results While the three-group model for the severity (mild,moderate,severe) and frequency (low,medium,high) of headache appeared to be appropriate,the four-group model for the duration (low,medium,high,extremely high) was more suitable. The severity of headache increased in the patients with nausea,vomiting,photophobia and phonophobia.The frequency of headache was especially related with increasing age and unilateral pain. Nausea and photophobia were also related with headache duration.Conclusions Nausea,vomiting and photophobia were the most significant factors to identify developmental trajectories.The remission time was not the same for the severity,frequency,and duration of headache.

  9. Flat plate solar air heater with latent heat storage

    Science.gov (United States)

    Touati, B.; Kerroumi, N.; Virgone, J.

    2017-02-01

    Our work contains two parts, first is an experimental study of the solar air heater with a simple flow and forced convection, we can use thatlaste oneit in many engineering's sectors as solardrying, space heating in particular. The second part is a numerical study with ansys fluent 15 of the storage of part of this solar thermal energy produced,using latent heat by using phase change materials (PCM). In the experimental parts, we realize and tested our solar air heater in URER.MS ADRAR, locate in southwest Algeria. Where we measured the solarradiation, ambient temperature, air flow, thetemperature of the absorber, glasses and the outlet temperature of the solar air heater from the Sunrise to the sunset. In the second part, we added a PCM at outlet part of the solar air heater. This PCM store a part of the energy produced in the day to be used in peak period at evening by using the latent heat where the PCMs present a grateful storagesystem.A numerical study of the fusion or also named the charging of the PCM using ANSYS Fluent 15, this code use the method of enthalpies to solve the fusion and solidification formulations. Furthermore, to improve the conjugate heat transfer between the heat transfer fluid (Air heated in solar plate air heater) and the PCM, we simulate the effect of adding fins to our geometry. Also, four user define are write in C code to describe the thermophysicalpropriety of the PCM, and the inlet temperature of our geometry which is the temperature at the outflow of the solar heater.

  10. Nanoscale control of interfacial processes for latent fingerprint enhancement.

    Science.gov (United States)

    Sapstead, Rachel M; Ryder, Karl S; Fullarton, Claire; Skoda, Maximilian; Dalgliesh, Robert M; Watkins, Erik B; Beebee, Charlotte; Barker, Robert; Glidle, Andrew; Hillman, A Robert

    2013-01-01

    Latent fingerprints on metal surfaces may be visualized by exploiting the insulating characteristics of the fingerprint deposit as a "mask" to direct electrodeposition of an electroactive polymer to the bare metal between the fingerprint ridges. This approach is complementary to most latent fingerprint enhancement methods, which involve physical or chemical interaction with the fingerprint residue. It has the advantages of sensitivity (a nanoscale residue can block electron transfer) and, using a suitable polymer, optimization of visual contrast. This study extends the concept in two significant respects. First, it explores the feasibility of combining observation based on optical absorption with observation based on fluorescence. Second, it extends the methodology to materials (here, polypyrrole) that may undergo post-deposition substitution chemistry, here binding of a fluorophore whose size and geometry preclude direct polymerization of the functionalised monomer. The scenario involves a lateral spatial image (the whole fingerprint, first level detail) at the centimetre scale, with identification features (minutiae, second level detail) at the 100-200 microm scale and finer features (third level detail) at the 10-50 microm scale. However, the strategy used requires vertical spatial control of the (electro)chemistry at the 10-100 nm scale. We show that this can be accomplished by polymerization of pyrrole functionalised with a good leaving group, ester-bound FMOC, which can be hydrolysed and eluted from the deposited polymer to generate solvent "voids". Overall the "void" volume and the resulting effect on polymer dynamics facilitate entry and amide bonding of Dylight 649 NHS ester, a large fluorophore. FTIR spectra demonstrate the spatially integrated compositional changes. Both the hydrolysis and fluorophore functionalization were followed using neutron reflectivity to determine vertical spatial composition variations, which control image development in the

  11. del alcoholismo

    Directory of Open Access Journals (Sweden)

    Rodrigo Arias Duque

    2005-01-01

    Full Text Available Desde el punto de vista farmacológico, es importante comprender qué es el alcohol y cómo actúa en el organismo. No existe una causa simple, sino una interacción complicada de factores neuroquímicos, fisiológicos, psicológicos y sociales que originan y desarrollan esta grave enfermedad fármaco-dependiente. La acción psicofisiológica y farmacodinámica del alcohol es fundamentalmente depresiva, por la reducción de la transmisión sináptica en el sistema nervioso humano. Es un hecho conocido que el consumo excesivo de alcohol causa una disfunción aguda y crónica del cerebro, produciendo trastornos en el sistema nervioso central, presentando alteraciones en la memoria y en las funciones intelectuales como cálculo, comprensión y aprendizaje. A nivel hepático tiene lugar, en su mayoría, el metabolismo del alcohol, produciéndose un hígado graso alcohólico, aumentando el tamaño, terminando en necrosis e inflamación grave del hígado; esto se llama hepatitis alcohólica, y si se sigue consumiendo alcohol se desarrollará la cirrosis. El alcohol también ha estado relacionado con alteraciones del miocardio; se ha constatado en animales de experimentación sanos que tanto la velocidad de contracción del músculo cardiaco y su máxima tensión disminuyen en presencia del alcohol, como consecuencia, la fuerza de cada contracción y el aumento de presión en el ventrículo izquierdo son menores, perdiendo eficacia el corazón como bomba.

  12. Personality types in childhood: relations to latent trajectory classes of problem behavior and overreactive parenting across the transition into adolescence

    NARCIS (Netherlands)

    van den Akker, A.L.; Deković, M.; Asscher, J.J.; Shiner, R.L.; Prinzie, P.

    2013-01-01

    This study investigated relations among children's personality types, trajectories of internalizing and externalizing problems, and overreactive parenting across 6 years. Latent Class Analysis of the Big 5 personality dimensions (modeled as latent factors, based on mother, father and teacher reports

  13. Effect of dopamine and serotonin receptor antagonists on fencamfamine-induced abolition of latent inhibition.

    Science.gov (United States)

    de Aguiar, Cilene Rejane Ramos Alves; de Aguiar, Marlison José Lima; DeLucia, Roberto; Silva, Maria Teresa Araujo

    2013-01-05

    The purpose of this investigation was to verify the role of dopamine and serotonin receptors in the effect of fencamfamine (FCF) on latent inhibition. FCF is a psychomotor stimulant with an indirect dopaminergic action. Latent inhibition is a model of attention. Latent inhibition is blocked by dopaminergic agents and facilitated by dopamine receptor agonists. FCF has been shown to abolish latent inhibition. The serotonergic system may also participate in the neurochemical mediation of latent inhibition. The selective dopamine D(1) receptor antagonist SCH 23390 (7-chloro-3-methyl-1-phenyl-1,2,4,5-tetrahydro-3-benzazepin-8-ol), D(2) receptor antagonists pimozide (PIM) and methoclopramide (METH), and serotonin 5-HT(2A/C) receptor antagonist ritanserin (RIT) were used in the present study. Latent inhibition was evaluated using a conditioned emotional response procedure. Male Wistar rats that were water-restricted were subjected to a three-phase procedure: preexposure to a tone, tone-shock conditioning, and a test of the effect of the tone on licking frequency. All of the drugs were administered before the preexposure and conditioning phases. The results showed that FCF abolished latent inhibition, and this effect was clearly antagonized by PIM and METH and moderately attenuated by SCH 23390. At the doses used in the present study, RIT pretreatment did not affect latent inhibition and did not eliminate the effect of FCF, suggesting that the FCF-induced abolition of latent inhibition is not mediated by serotonin 5-HT(2A/C) receptors. These results suggest that the effect of FCF on latent inhibition is predominantly related to dopamine D(2) receptors and that dopamine D(2) receptors participate in attention processes.

  14. The GABAА receptors agonists and antagonists influence on formation of a latent inhibition at rats with different levels of anxiety

    OpenAIRE

    A. V. Redkina; L. V. Loskutova; Т. A. Zamoshchina

    2012-01-01

    Latent inhibition phenomenon indexes the ability to ignore irrelevant stimuli. Disturbance of latent inhibition is registered in different psychiatric populations with pathology in the emotional and cognitive spheres. In our experiments latent inhibition was measured in a conditioned passive avoidance reaction in rats that previously received 0 or 20 conditioned stimuli exposures followed by foot shock. Latent inhibition was disrupted in high-anxiety rats and pathologically enhanced in low-an...

  15. Repercusión perinatal de los trastornos inmunológicos del embarazo Perintal effect of immunological disorders during pregnancy

    Directory of Open Access Journals (Sweden)

    Rafael J. Manotas Cabarcas

    1993-03-01

    Full Text Available

    En esta revisión se analizan varios trastornos de índole inmunológica, comprobada o supuesta, que ocurren durante el embarazo, a saber: hipertensión, diabetes mellitus, hipertiroidismo, hipotiroidismo, trombocitopenia aloinmune y autoinmune, lupus eritematoso sistémico y miastenia gravis. En cada caso se describen la patogénesis y los efectos perinatales y se hacen consideraciones diagnósticas y terapéuticas para la orientación del obstetra y del pediatra.

    Several disorders of proven or supposed immunological nature, that occur during pregnancy are described, namely: arterial hypertension, diabetes mellitus, hyperthyroidism, hypothyroidism, alloimmune and autoimmune thrombocytopenia, erythematous systemic lupus and myastenia gravis. The pathogenesis and perinatal effects of each one are described and diagnostic and therapeutic considerations are made for orientation of obstetricians and pediatricians.

  16. Decomposing Person and Occasion-Specific Effects: An Extension of Latent State-Trait (LSI) Theory to Hierarchical LST Models

    Science.gov (United States)

    Schermelleh-Engel, Karin; Keith, Nina; Moosbrugger, Helfried; Hodapp, Volker

    2004-01-01

    An extension of latent state-trait (LST) theory to hierarchical LST models is presented. In hierarchical LST models, the covariances between 2 or more latent traits are explained by a general 3rd-order factor, and the covariances between latent state residuals pertaining to different traits measured on the same measurement occasion are explained…

  17. Estimating Non-Normal Latent Trait Distributions within Item Response Theory Using True and Estimated Item Parameters

    Science.gov (United States)

    Sass, D. A.; Schmitt, T. A.; Walker, C. M.

    2008-01-01

    Item response theory (IRT) procedures have been used extensively to study normal latent trait distributions and have been shown to perform well; however, less is known concerning the performance of IRT with non-normal latent trait distributions. This study investigated the degree of latent trait estimation error under normal and non-normal…

  18. Joint modeling of repeated multivariate cognitive measures and competing risks of dementia and death: a latent process and latent class approach.

    Science.gov (United States)

    Proust-Lima, Cécile; Dartigues, Jean-François; Jacqmin-Gadda, Hélène

    2016-02-10

    Joint models initially dedicated to a single longitudinal marker and a single time-to-event need to be extended to account for the rich longitudinal data of cohort studies. Multiple causes of clinical progression are indeed usually observed, and multiple longitudinal markers are collected when the true latent trait of interest is hard to capture (e.g., quality of life, functional dependency, and cognitive level). These multivariate and longitudinal data also usually have nonstandard distributions (discrete, asymmetric, bounded, etc.). We propose a joint model based on a latent process and latent classes to analyze simultaneously such multiple longitudinal markers of different natures, and multiple causes of progression. A latent process model describes the latent trait of interest and links it to the observed longitudinal outcomes using flexible measurement models adapted to different types of data, and a latent class structure links the longitudinal and cause-specific survival models. The joint model is estimated in the maximum likelihood framework. A score test is developed to evaluate the assumption of conditional independence of the longitudinal markers and each cause of progression given the latent classes. In addition, individual dynamic cumulative incidences of each cause of progression based on the repeated marker data are derived. The methodology is validated in a simulation study and applied on real data about cognitive aging obtained from a large population-based study. The aim is to predict the risk of dementia by accounting for the competing death according to the profiles of semantic memory measured by two asymmetric psychometric tests.

  19. Fisiopatología del exoftalmos endocrino: Aspectos históricos Pathophysiology of Endocrine Exophthalmos

    Directory of Open Access Journals (Sweden)

    MA Pisarev

    2012-09-01

    Full Text Available La fisiopatología del exoftalmos endocrino ha ido evolucionando a lo largo del tiempo. En primer lugar fue necesario que los trabajos originales de Graves y de Basedow asociaran la alteración ocular con la disfunción tiroidea. Estudios complementarios demostraron que el exoftalmos también se puede observar en pacientes con Tiroiditis de Hashimoto. Estudios posteriores han demostrado la presencia de una sustancia o factor al que denominaron Factor exoftalmizante en el suero de pacientes. La demostración experimental de que se podía producir exoftalmos por un mecanismo autoinmune y la demostración de la presencia de un estimulador tiroideo de acción prolongada (LATS llevó al concepto actual acerca de la participación de un mecanismo inmunológico en la fisipatología de esta afección. Los autores declaran no poseer conflictos de interés.The pathophysiology of endocrine exophthalmos has changed with the advances of Medicine. Described for the first time associated with hyperthyroidism by Graves and von Basedow, further studies demonstrated that it also may occur in patients with autoimmune thyroiditis. It is caused by the increase of retro ocular tissue volume. An exophthalmos producing substance (EPS was found in the serum of those patients. The experimental demonstration that exophthalmos may be prduced by an autoimmune mechanism, and the finding that a circulating immunoglobulin, the Long Acting Thyroid Stimulator (LATS is the cause of Graves disease, led to the present concept on the pathogrenesis of this disease The authors do not have conflicts of interest.

  20. Valoración médico-laboral del trabajador con Síndrome de Sjögren

    Directory of Open Access Journals (Sweden)

    Maider Usarbarrena Ekiza

    2014-03-01

    Full Text Available El Síndrome de Sjögren (SS es una patología inflamatoria crónica, infradiagnosticada y de etiología desconocida, que se caracteriza por la infiltración linfocitaria de las glándulas exocrinas. La sintomatología puede ser muy variada. Inicialmente, lo más común es que se presente sequedad de mucosas (principalmente oculares y bucales; también se puede asociar a otras enfermedades autoinmunes, y hasta en el 65% de los casos, se pueden presentar manifestaciones extraglandulares, pudiéndose afectar cualquier parte del organismo. En muchos casos, la sintomatología inicial es leve, achacándose habitualmente a un posible disconfort en el puesto de trabajo. A esto hay que añadir que a nivel laboral no existe literatura específica en la que poder basarse para realizar una adecuada valoración médico-laboral. El objetivo de este trabajo ha sido crear una herramienta que englobe, por una parte, la vigilancia de la salud específica, y por otra, definir (aunque sea de forma orientativa, los criterios para poder realizar una correcta valoración de la capacidad laboral en los trabajadores con Síndrome de Sjögren.

  1. La responsabilídad social en empresas del Valle de Toluca (México): un estudio exploratorio

    OpenAIRE

    Mercado Salgado, Patricia

    2007-01-01

    En un mundo globalizado, el sector empresarial no puede seguir negando la necesidad de adoptar la responsabilidad social como estrategia para alcanzar beneficios externos e internos, pues sigue latente cierto comportamiento dominante de rechazo hacia ella. Por ello, el objetivo de esta investigación exploratoria, no experimental, es describir la responsabilidad social en empresas del Valle de Toluca (México) mediante cuatro componentes: ética empresarial, preservación del medio ambiente, cali...

  2. Behaviorism, latent learning, and cognitive maps: needed revisions in introductory psychology textbooks.

    Science.gov (United States)

    Jensen, Robert

    2006-01-01

    This paper critically assesses the scholarship in introductory psychology textbooks in relation to the topic of latent learning. A review of the treatment of latent learning in 48 introductory psychology textbooks published between 1948 and 2004, with 21 of these texts published since 1999, reveals that the scholarship on the topic of latent learning demonstrated in introductory textbooks warrants improvement. Errors that persist in textbooks include the assertion that the latent learning experiments demonstrate unequivocally that reinforcement was not necessary for learning to occur, that behavioral theories could not account for the results of the latent learning experiments, that B. F. Skinner was an S-R association behaviorist who argued that reinforcement is necessary for learning to occur, and that because behavioral theories (including that of B. F. Skinner) were unable explain the results of the latent learning experiments the cognitive map invoked by Edward Tolman is the only explanation for latent learning. Finally, the validity of the cognitive map is typically accepted without question. Implications of the presence of these errors for students and the discipline are considered. Lastly, remedies are offered to improve the scholarship found in introductory psychology textbooks.

  3. Does a latent class underlie schizotypal personality disorder? Implications for schizophrenia.

    Science.gov (United States)

    Ahmed, Anthony O; Green, Bradley A; Goodrum, Nada M; Doane, Nancy J; Birgenheir, Denis; Buckley, Peter F

    2013-05-01

    Despite growing enthusiasm for dimensional models of personality pathology, the taxonic versus dimensional status of schizotypal personality disorder (PD) remains a point of contention in modern psychiatry. The current study aimed to determine empirically the latent structure of schizotypal PD. We examined the latent structure of schizotypal PD in the Psychiatric Morbidity Survey in Great Britain and the second wave of the U.S.-based National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) survey. We analyzed composite indicators created from participant responses using the mean above minus mean below a cut (MAMBAC), Maximum Covariance (MAXCOV), and latent mode factor analysis (L-Mode) taxometric procedures. We also analyzed item-level responses using two latent variable mixture models--latent class analysis and latent class factor analysis. Taxometric and latent variable mixture analyses supported a dimensional, rather than taxonic, structure in both epidemiological samples. The dimensional model better predicted psychosis, intellectual functioning, disability, and treatment seeking than the categorical model based on DSM-IV diagnosis. People meeting criteria for schizotypal PD appear to exist on a spectrum of severity with the rest of the population. The possible dimensionality of schizotypal PD adds to growing support for a dimensional structure of PDs including other Cluster A disorders.

  4. El Shock de los precios del Petróleo en América Central: Implicancias fiscales y energéticas

    OpenAIRE

    Artana, Daniel; Catena, Marcelo; Navajas, Fernando

    2007-01-01

    Se estudian las implicancias fiscales y energéticas de la escalada en los precios del petróleo estimando efectos directos e indirectos. Dado que las economías se hallan en una fase expansiva, estimamos, un impacto “latente”sobre el PIB, respecto de las condiciones iniciales (año 2003), que a su vez lleva a una pérdida latente en la recaudación fiscal del 0. 7% PIB promedio entre países. A diferencia de este efecto latente, la perdida directa observada en la recaudación de impuestos a los hidr...

  5. Culturas del Mundo

    DEFF Research Database (Denmark)

    Benwell, Ann Fenger; Costa, Alberto; Waehle, Espen

    2006-01-01

    ’Culturas del mundo. Colecciones del Museo Nacional de Dinamarca’ with Ann Fenger Benwell in Culturas del Mundo. Colecciones del Museo Nacional de Dinamarca, ed. Silvia Sauquet, Fundación "la Caixa", Barcelona 2006, pp. 31-39......’Culturas del mundo. Colecciones del Museo Nacional de Dinamarca’ with Ann Fenger Benwell in Culturas del Mundo. Colecciones del Museo Nacional de Dinamarca, ed. Silvia Sauquet, Fundación "la Caixa", Barcelona 2006, pp. 31-39...

  6. Extraction of Latent Dynamical Structure from Time-Series Spectral Data

    Science.gov (United States)

    Murata, Shin; Nagata, Kenji; Uemura, Makoto; Okada, Masato

    2016-10-01

    The estimation of latent dynamics from time-series data is an important problem in a broad range of fields. In this research, we focused on time-series spectral data, which are obtained in planetary science, condensed matter science, and many other fields, and their latent dynamics. Time-series spectral data have a multiple-peak structure and the center, width, and amplitude of each peak reflect the nature of the subject. Here, we propose a method to estimate the parameters of peaks, the parameters of their latent dynamics, the number of peaks, and the order of the model by using Bayesian inference.

  7. Latent Variable Selection for Multidimensional Item Response Theory Models via [Formula: see text] Regularization.

    Science.gov (United States)

    Sun, Jianan; Chen, Yunxiao; Liu, Jingchen; Ying, Zhiliang; Xin, Tao

    2016-12-01

    We develop a latent variable selection method for multidimensional item response theory models. The proposed method identifies latent traits probed by items of a multidimensional test. Its basic strategy is to impose an [Formula: see text] penalty term to the log-likelihood. The computation is carried out by the expectation-maximization algorithm combined with the coordinate descent algorithm. Simulation studies show that the resulting estimator provides an effective way in correctly identifying the latent structures. The method is applied to a real dataset involving the Eysenck Personality Questionnaire.

  8. Vasopeptidase-activated latent ligands of the histamine receptor-1.

    Science.gov (United States)

    Gera, Lajos; Roy, Caroline; Charest-Morin, Xavier; Marceau, François

    2013-11-01

    Whether peptidases present in vascular cells can activate prodrugs active on vascular cells has been tested with 2 potential latent ligands of the histamine H1 receptor (H1R). First, a peptide consisting of the antihistamine cetirizine (CTZ) condensed at the N-terminus of ε-aminocaproyl-bradykinin (εACA-BK) was evaluated for an antihistamine activity that could be revealed by degradation of the peptide part of the molecule. CTZ-εACA-BK had a submicromolar affinity for the BK B2 receptor (B2R; IC50 of 590 nM, [(3)H]BK binding competition), but a non-negligible affinity for the human H1 receptor (H1R; IC50 of 11 μM for [(3)H]pyrilamine binding). In the human isolated umbilical vein, a system where both endogenous B2R and H1R mediate strong contractions, CTZ-εACA-BK exerted mild antagonist effects on histamine-induced contraction that were not modified by omapatrilat or by a B2R antagonist that prevents endocytosis of the BK conjugate. Cells expressing recombinant ACE or B2R incubated with CTZ-εACA-BK did not release a competitor of [(3)H]pyrilamine binding to H1Rs. Thus, there is no evidence that CTZ-εACA-BK can release free cetirizine in biological environments. The second prodrug was a blocked agonist, L-alanyl-histamine, potentially activated by aminopeptidase N (APN). This compound did not compete for [(3)H]pyrilamine binding to H1Rs. The human umbilical vein contractility assay responded to L-alanyl-histamine (EC50 54.7 μM), but the APN inhibitor amastatin massively (17-fold) reduced its apparent potency. Amastatin did not influence the potency of histamine as a contractile agent. One of the 2 tested latent H1R ligands, L-alanyl-histamine, supported the feasibility of pro-drug activation by vascular ectopeptidases.

  9. Latent and Abnormal Functional Connectivity Circuits in Autism Spectrum Disorder

    Science.gov (United States)

    Chen, Shuo; Xing, Yishi; Kang, Jian

    2017-01-01

    Autism spectrum disorder (ASD) is associated with disrupted brain networks. Neuroimaging techniques provide noninvasive methods of investigating abnormal connectivity patterns in ASD. In the present study, we compare functional connectivity networks in people with ASD with those in typical controls, using neuroimaging data from the Autism Brain Imaging Data Exchange (ABIDE) project. Specifically, we focus on the characteristics of intrinsic functional connectivity based on data collected by resting-state functional magnetic resonance imaging (rs-fMRI). Our aim was to identify disrupted brain connectivity patterns across all networks, instead of in individual edges, by using advanced statistical methods. Unlike many brain connectome studies, in which networks are prespecified before the edge connectivity in each network is compared between clinical groups, we detected the latent differentially expressed networks automatically. Our network-level analysis identified abnormal connectome networks that (i) included a high proportion of edges that were differentially expressed between people with ASD and typical controls; and (ii) showed highly-organized graph topology. These findings provide new insight into the study of the underlying neuropsychiatric mechanism of ASD.

  10. Future expectations among adolescents: a latent class analysis.

    Science.gov (United States)

    Sipsma, Heather L; Ickovics, Jeannette R; Lin, Haiqun; Kershaw, Trace S

    2012-09-01

    Future expectations have been important predictors of adolescent development and behavior. Its measurement, however, has largely focused on single dimensions and misses potentially important components. This analysis investigates whether an empirically-driven, multidimensional approach to conceptualizing future expectations can substantively contribute to our understanding of adolescent risk behavior. We use data from the National Longitudinal Survey of Youth 1997 to derive subpopulations of adolescents based on their future expectations with latent class analysis. Multinomial regression then determines which covariates from Bronfenbrenner's ecological systems theory are associated with class membership. After modeling these covariates, we examine whether future expectations is associated with delinquency, substance use, and sexual experience. Our analysis suggests the emergence of four distinct classes labeled the Student Expectations, Student/Drinking Expectations, Victim Expectations, and Drinking/Arrest Expectations classes according to their indicator profiles. These classes differ with respect to covariates associated with membership; furthermore, they are all statistically and differentially associated with at least one adolescent risk behavior. This analysis demonstrates the additional benefit derived from using this multidimensional approach for studying future expectations. Further research is needed to investigate its stability and role in predicting adolescent risk behavior over time.

  11. Multiplexed Imaging of Trace Residues in a Single Latent Fingerprint.

    Science.gov (United States)

    Zhang, Yuyan; Zhou, Wen; Xue, Yang; Yang, Jie; Liu, Dingbin

    2016-12-20

    The development of highly sensitive, selective, nondestructive, and multiplexed imaging modalities is essential for latent fingerprint (LFP) identification and fingerprint residues detection. Herein, we present a versatile strategy to identify LFPs and to probe the multiple trace residues in a single LFP simultaneously. With the purpose of achieving high sensitivity, we for the first time introduced a polydopamine (PDA)-triggered Au growth method to prepare superbright and multiplex surface-enhanced Raman scattering (SERS) tags, which were endowed with high selectivity by conjugating with specific antibodies. In combination with a rapid Raman mapping technique, the sensitivity of the SERS probes was down to picogram scale and all the three levels of LFP features can be clearly seen. More significantly, the multiplexed imaging of diverse residues in a single LFP provides more accurate information than that using monochromatic imaging of individuals alone. The high analytical figures of merit enable this approach great promise for use in the fields ranging from chemical detection to molecular imaging.

  12. Integrated Multiscale Latent Variable Regression and Application to Distillation Columns

    Directory of Open Access Journals (Sweden)

    Muddu Madakyaru

    2013-01-01

    Full Text Available Proper control of distillation columns requires estimating some key variables that are challenging to measure online (such as compositions, which are usually estimated using inferential models. Commonly used inferential models include latent variable regression (LVR techniques, such as principal component regression (PCR, partial least squares (PLS, and regularized canonical correlation analysis (RCCA. Unfortunately, measured practical data are usually contaminated with errors, which degrade the prediction abilities of inferential models. Therefore, noisy measurements need to be filtered to enhance the prediction accuracy of these models. Multiscale filtering has been shown to be a powerful feature extraction tool. In this work, the advantages of multiscale filtering are utilized to enhance the prediction accuracy of LVR models by developing an integrated multiscale LVR (IMSLVR modeling algorithm that integrates modeling and feature extraction. The idea behind the IMSLVR modeling algorithm is to filter the process data at different decomposition levels, model the filtered data from each level, and then select the LVR model that optimizes a model selection criterion. The performance of the developed IMSLVR algorithm is illustrated using three examples, one using synthetic data, one using simulated distillation column data, and one using experimental packed bed distillation column data. All examples clearly demonstrate the effectiveness of the IMSLVR algorithm over the conventional methods.

  13. Visualization of latent fingerprint corrosion of metallic surfaces.

    Science.gov (United States)

    Bond, John W

    2008-07-01

    Chemical reactions between latent fingerprints and a variety of metal surfaces are investigated by heating the metal up to temperatures of approximately 600 degrees C after deposition of the fingerprint. Ionic salts present in the fingerprint residue corrode the metal surface to produce an image of the fingerprint that is both durable and resistant to cleaning of the metal. The degree of fingerprint enhancement appears independent of the elapsed time between deposition and heating but is very dependent on both the composition of the metal and the level of salt secretion by the fingerprint donor. Results are presented that show practical applications for the enhancement to fingerprints deposited in arson crime scenes, contaminated by spray painting, or deposited on brass cartridge cases prior to discharge. The corrosion of the metal surface is further exploited by the demonstration of a novel technique for fingerprint enhancement based on the electrostatic charging of the metal and then the preferential adherence of a metallic powder to the corroded part of the metal surface.

  14. Enhancing multilingual latent semantic analysis with term alignment information.

    Energy Technology Data Exchange (ETDEWEB)

    Chew, Peter A.; Bader, Brett William

    2008-08-01

    Latent Semantic Analysis (LSA) is based on the Singular Value Decomposition (SVD) of a term-by-document matrix for identifying relationships among terms and documents from co-occurrence patterns. Among the multiple ways of computing the SVD of a rectangular matrix X, one approach is to compute the eigenvalue decomposition (EVD) of a square 2 x 2 composite matrix consisting of four blocks with X and XT in the off-diagonal blocks and zero matrices in the diagonal blocks. We point out that significant value can be added to LSA by filling in some of the values in the diagonal blocks (corresponding to explicit term-to-term or document-to-document associations) and computing a term-by-concept matrix from the EVD. For the case of multilingual LSA, we incorporate information on cross-language term alignments of the same sort used in Statistical Machine Translation (SMT). Since all elements of the proposed EVD-based approach can rely entirely on lexical statistics, hardly any price is paid for the improved empirical results. In particular, the approach, like LSA or SMT, can still be generalized to virtually any language(s); computation of the EVD takes similar resources to that of the SVD since all the blocks are sparse; and the results of EVD are just as economical as those of SVD.

  15. The Stability of Social Desirability: A Latent Change Analysis.

    Science.gov (United States)

    Haberecht, Katja; Schnuerer, Inga; Gaertner, Beate; John, Ulrich; Freyer-Adam, Jennis

    2015-08-01

    Social desirability has been shown to be stable in samples with higher school education. However, little is known about the stability of social desirability in more heterogeneous samples differing in school education. This study aimed to investigate the stability of social desirability and which factors predict interindividual differences in intraindividual change. As part of a randomized controlled trial, 1,243 job seekers with unhealthy alcohol use were systematically recruited at three job agencies. A total of 1,094 individuals (87.8%) participated in at least one of two follow-ups (6 and 15 months after baseline) and constitute this study's sample. The Social Desirability Scale-17 was applied. Two latent change models were conducted: Model 1 tested for interindividual differences in intraindividual change of social desirability between both follow-ups; Model 2 included possible predictors (age, sex, education, current employment status) of interindividual differences in intraindividual change. Model 1 revealed a significant decrease of social desirability over time. Model 2 revealed school education to be the only significant predictor of change. These findings indicate that stability of social desirability may depend on school education. It may not be as stable in individuals with higher school education as in individuals with lower education.

  16. Identifying gene regulatory network rewiring using latent differential graphical models.

    Science.gov (United States)

    Tian, Dechao; Gu, Quanquan; Ma, Jian

    2016-09-30

    Gene regulatory networks (GRNs) are highly dynamic among different tissue types. Identifying tissue-specific gene regulation is critically important to understand gene function in a particular cellular context. Graphical models have been used to estimate GRN from gene expression data to distinguish direct interactions from indirect associations. However, most existing methods estimate GRN for a specific cell/tissue type or in a tissue-naive way, or do not specifically focus on network rewiring between different tissues. Here, we describe a new method called Latent Differential Graphical Model (LDGM). The motivation of our method is to estimate the differential network between two tissue types directly without inferring the network for individual tissues, which has the advantage of utilizing much smaller sample size to achieve reliable differential network estimation. Our simulation results demonstrated that LDGM consistently outperforms other Gaussian graphical model based methods. We further evaluated LDGM by applying to the brain and blood gene expression data from the GTEx consortium. We also applied LDGM to identify network rewiring between cancer subtypes using the TCGA breast cancer samples. Our results suggest that LDGM is an effective method to infer differential network using high-throughput gene expression data to identify GRN dynamics among different cellular conditions.

  17. Development of composite latent/sensible heat storage media

    Science.gov (United States)

    Petri, R.; Ong, E. T.; Kardas, A.

    1990-12-01

    Results of an on-going program to develop a composite latent-sensible thermal energy storage medium, trade marked CompPhase, are presented. The target application area was periodic kiln energy recovery. The concept is that of a composite salt/ceramic material processed such that the medium maintains its shape and mechanical integrity through the salt melting temperature. As such, the media can be fabricated into a variety of shapes suitable for packed beds, fluidized beds, or direct contact heat exchangers. The properties of ten carbonate salt or eutectic mixtures of carbonate salts were reviewed to select the most appropriate candidates for development. Three salts and two ceramic materials were evaluated in laboratory tests to select the final material, a composite of sodium-barium eutectic/magnesium oxide, for development. Two methods of processing the constituent powders for fabrication into storage pellets were developed, and one method was applied to pellet fabrication by commercial processing equipment. Two different preliminary cost estimates bracketed the expected cost of commercially fabricating storage pellets. Also, two modifications to the material processing method were suggested to reduce costs. Thermal cycling was conducted on laboratory produced experimental pellets and on prototype pellets fabricated by commercial processes. Detailed laboratory tests to determine composite mechanical and thermal properties were conducted. It is concluded that further laboratory, field, and economic studies are required before the concept of composite storage media can be considered fully developed for commercialization.

  18. Modeling media as latent semantics based on cognitive components

    DEFF Research Database (Denmark)

    Petersen, Michael Kai

    Though one might think of media as an audiovisual stream of consciousness, we frequently encode frames of video sequences and waves of sound into strings of text. Language allows us to both share the internal representations of what we perceive as mental concepts, as well as categorizing them as ...... with aspects of cognitive linguistics that potentially could be utilized in applications ranging from information retrieval and media personalization, to emotional brand building or neuroscientific modeling of syntax and semantics....... and share the meaning contained within a sentence or a melodic phrase. As both low-level semantic structure of texts and our affective responses can be encoded in words, a simplified cognitive model can be constructed which uses LSA latent semantic analysis to emulate how we perceive the emotional context...... of media based on lyrics, synopses, subtitles, blogs or web pages associated with the content. In the proposed model the bottom-up generated sensory input is a matrix of tens of thousands of words co-occurring within multiple contexts, that are in turn represented as vectors in a semantic space of reduced...

  19. Latent Clustering Models for Outlier Identification in Telecom Data

    Directory of Open Access Journals (Sweden)

    Ye Ouyang

    2016-01-01

    Full Text Available Collected telecom data traffic has boomed in recent years, due to the development of 4G mobile devices and other similar high-speed machines. The ability to quickly identify unexpected traffic data in this stream is critical for mobile carriers, as it can be caused by either fraudulent intrusion or technical problems. Clustering models can help to identify issues by showing patterns in network data, which can quickly catch anomalies and highlight previously unseen outliers. In this article, we develop and compare clustering models for telecom data, focusing on those that include time-stamp information management. Two main models are introduced, solved in detail, and analyzed: Gaussian Probabilistic Latent Semantic Analysis (GPLSA and time-dependent Gaussian Mixture Models (time-GMM. These models are then compared with other different clustering models, such as Gaussian model and GMM (which do not contain time-stamp information. We perform computation on both sample and telecom traffic data to show that the efficiency and robustness of GPLSA make it the superior method to detect outliers and provide results automatically with low tuning parameters or expertise requirement.

  20. Latent Factor Structure of DSM-5 Posttraumatic Stress Disorder.

    Science.gov (United States)

    Gentes, Emily; Dennis, Paul A; Kimbrel, Nathan A; Kirby, Angela C; Hair, Lauren P; Beckham, Jean C; Calhoun, Patrick S

    The current study examined the latent factor structure of posttraumatic stress disorder (PTSD) based on DSM-5 criteria in a sample of participants (N = 374) recruited for studies on trauma and health. Confirmatory factor analyses (CFA) were used to compare the fit of the previous 3-factor DSM-IV model of PTSD to the 4-factor model specified in DSM-5 as well as to a competing 4-factor "dysphoria" model (Simms, Watson, & Doebbeling, 2002) and a 5-factor (Elhai et al., 2011) model of PTSD. Results indicated that the Elhai 5-factor model (re-experiencing, active avoidance, emotional numbing, dysphoric arousal, anxious arousal) provided the best fit to the data, although substantial support was demonstrated for the DSM-5 4-factor model. Low factor loadings were noted for two of the symptoms in the DSM-5 model (psychogenic amnesia and reckless/self-destructive behavior), which raises questions regarding the adequacy of fit of these symptoms with other core features of the disorder. Overall, the findings from the present research suggest the DSM-5 model of PTSD is a significant improvement over the previous DSM-IV model of PTSD.

  1. Latent inhibition of conditioned disgust reactions in rats.

    Science.gov (United States)

    López, Matías; Gasalla, Patricia; Vega, Mercedes; Limebeer, Cheryl L; Rock, Erin M; Tuerke, Katharine J; Bedard, Holly; Parker, Linda A

    2010-05-01

    The present experiments, using the latent inhibition (LI) paradigm, evaluated the effect of nonreinforced exposure to saccharin on the acquisition of an LiCl-induced saccharin aversion as measured by conditioned disgust reactions in the taste reactivity test and conditioned taste avoidance in a consumption test. When rats were preexposed to saccharin by bottle exposure (Experiments 1 and 3), LI was evidenced only by conditioned taste avoidance (bottle testing), but not by conditioned disgust reactions (intraoral [IO] testing). On the other hand, when rats were preexposed to saccharin by IO infusion (Experiments 2 and 3), LI was evidenced only by conditioned disgust reactions, but not by conditioned taste avoidance. Experiment 4 showed that LI of conditioned disgust reactions does not appear to be affected by a context shift from preexposure to testing phases. These results show that the expression of LI of both conditioned taste avoidance and conditioned disgust reactions depends critically on a common method of flavor exposure during preexposure and testing.

  2. Latent inhibition of a conditioned taste aversion in fetal rats.

    Science.gov (United States)

    Mickley, G Andrew; Hoxha, Zana; DiSorbo, Anthony; Wilson, Gina N; Remus, Jennifer L; Biesan, Orion; Ketchesin, Kyle D; Ramos, Linnet; Luchsinger, Joseph R; Prodan, Suzanna; Rogers, Morgan; Wiles, Nathanael R; Hoxha, Nita

    2014-04-01

    The etiology of schizophrenia's cognitive symptoms may have its basis in prenatal alterations of glutamate N-methyl-D-aspartate (NMDA) receptor functioning. Therefore, the current study investigated the effects of ketamine (an NMDA receptor blocking drug) on both a conditioned taste aversion (CTA) and latent inhibition (LI; a model of attentional capacity) in rat fetuses. We first sought to determine if a CTA could be diminished by nonreinforced preexposure to a CS in fetal rats (i.e., LI). We injected E18 pregnant Sprague-Dawley rats with 100% allicin (garlic taste) or an equal volume of saline. Some of the pregnant dams also received ketamine (100 mg/kg, i.p.). One day later (E19), the dams received a second injection of the CS, followed by either lithium chloride (the US) or saline. Finally, on E21 pups received oral lavage with allicin and observations of ingestive orofacial motor responses were recorded. When allicin had been paired with LiCl in utero, E21 fetuses exhibited a conditioned suppression of orofacial movements, indicative of an aversion to this taste. Preexposure to the garlic taste on E18 produced a LI of this CTA. Ketamine significantly disrupted the formation of the CTA and had some impact on LI. However, the direct effect of ketamine on LI is less certain since the drug also blocked the original CTA.

  3. The loss of latent inhibition across compound conditioning.

    Science.gov (United States)

    Holmes, Nathan M; Harris, Justin A

    2009-07-01

    Six experiments used a magazine approach paradigm with rats to investigate latent inhibition (LI). Experiment 1 found that compound conditioning did not increase evidence for LI, in contrast to predictions from acquisition-deficit models that are based on a common error term (e.g., J. M. Pearce & G. Hall, 1980; A. R. Wagner, 1981). Instead, it appeared that preexposed and non-preexposed stimuli conditioned to the same asymptote following compound conditioning, as is the case when these stimuli are conditioned separately. This was confirmed in three further experiments that used probe trials to measure conditioning to each conditioned stimulus across the course of compound training. In these experiments, LI was observed during initial but not extended compound training, consistent with predictions derived from M. E. Bouton (1997) and the SLG model (N. A. Schmajuk, Y. Lam, & J. A. Gray, 1996). However, 2 further experiments did not support these models. Instead, these findings are most consistent with models that use separate error terms to compute the associative strength of conditioned stimuli conditioned in compound (S. E. Brandon, E. H. Vogel, & A. R. Wagner, 2003; M. E. Le Pelley, 2004; N. J. Mackintosh, 1975).

  4. The forgetting of stimulus attributes in latent inhibition.

    Science.gov (United States)

    Metzger, Mitchell M; Riccio, David C

    2009-01-08

    Numerous studies have demonstrated that the forgetting of stimulus attributes is a common occurrence; that is, organisms forget the specific characteristics of training stimuli over long retention intervals, while retaining general information of the training stimuli themselves. However, most studies have examined this effect after a learning episode, and there have been virtually no accounts to test whether the forgetting of attributes occurs for stimuli presented prior to training. Therefore, this experiment was designed to test that possibility, and it examined whether the forgetting of stimulus attributes occurred prior to training for the flavor stimulus in a conditioned taste aversion (CTA) procedure. Specifically, a latent inhibition (LI) procedure was used to measure the extent of forgetting for a pre-exposed flavor over short and long retention intervals. The results indicate that rats forgot the specific characteristics of the flavor stimulus (CS) while retaining memory for pre-exposure sessions over a long retention interval. That is, subjects pre-exposed and conditioned with different concentrations of sucrose showed no LI effect with a 1-day delay between pre-exposure and training, but demonstrated a generalized LI with an 8-day delay between pre-exposure and conditioning. This experiment provides further evidence for the robustness of the forgetting of stimulus attributes, and demonstrates that this specific type of forgetting also occurs prior to the learning of a CTA task.

  5. Latent Virus Reactivation in Astronauts and Shingles Patients

    Science.gov (United States)

    Mehta, Satish K.; Cohrs, Randall J.; Gilden, Donald H.; Tyring, Stephen K.; Castro, Victoria A.; Ott, C. Mark; Pierson, Duane L.

    2010-01-01

    Spaceflight is a uniquely stressful environment with astronauts experiencing a variety of stressors including: isolation and confinement, psychosocial, noise, sleep deprivation, anxiety, variable gravitational forces, and increased radiation. These stressors are manifested through the HPA and SAM axes resulting in increased stress hormones. Diminished T-lymphocyte functions lead to reactivation of latent herpesviruses in astronauts during spaceflight. Herpes simplex virus reactivated with symptoms during spaceflight whereas Epstein-Barr virus (EBV), cytomegalovirus (CMV), and varicella zoster virus (VZV) reactivate and are shed without symptoms. EBV and VZV are shed in saliva and CMV in the urine. The levels of EBV shed in astronauts increased 10-fold during the flight; CMV and VZV are not typically shed in low stressed individuals, but both were shed in astronauts during spaceflight. All herpes viruses were detected by polymerase chain reaction (PCR) assay. Culturing revealed that VZV shed in saliva was infectious virus. The PCR technology was extended to test saliva of 54 shingles patients. All shingles patients shed VZV in their saliva, and the levels followed the course of the disease. Viremia was also found to be common during shingles. The technology may be used before zoster lesions appear allowing for prevention of disease. The technology may be used for rapid detection of VZV in doctors offices. These studies demonstrated the value of applying technologies designed for astronauts to people on Earth.

  6. Invariant Gaussian Process Latent Variable Models and Application in Causal Discovery

    CERN Document Server

    Zhang, Kun; Janzing, Dominik

    2012-01-01

    In nonlinear latent variable models or dynamic models, if we consider the latent variables as confounders (common causes), the noise dependencies imply further relations between the observed variables. Such models are then closely related to causal discovery in the presence of nonlinear confounders, which is a challenging problem. However, generally in such models the observation noise is assumed to be independent across data dimensions, and consequently the noise dependencies are ignored. In this paper we focus on the Gaussian process latent variable model (GPLVM), from which we develop an extended model called invariant GPLVM (IGPLVM), which can adapt to arbitrary noise covariances. With the Gaussian process prior put on a particular transformation of the latent nonlinear functions, instead of the original ones, the algorithm for IGPLVM involves almost the same computational loads as that for the original GPLVM. Besides its potential application in causal discovery, IGPLVM has the advantage that its estimat...

  7. Using Latent Mixed Markov Models for the choice of the best pharmacological treatment.

    Science.gov (United States)

    Reuter, Martin; Hennig, Juergen; Netter, Petra; Buehner, Markus; Hueppe, Michael

    2004-05-15

    The choice of the best pharmacological treatment for an individual patient is crucial to optimize convalescence. Due to their effects on pharmacokinetics variables like gender and age are important factors when the pharmacological regimen is planned. By means of an example from anaesthesiology the usefulness of Latent Mixed Markov Models for choosing the optimal anaesthetic considering patient characteristics is demonstrated. Latent Mixed Markov models allow to predict and compare the quality of recovery from anaesthesia for different patient groups (defined by age and gender and treated with different anaesthetic regimens) in a multivariate non-parametric approach. On the basis of observed symptoms immediately after surgery and a few days later the probabilities for the respective dynamic latent status (like health or illness) and the probabilities for transition from one status to another are estimated depending on latent class membership (patient group).

  8. TAO/TRITON, RAMA, and PIRATA Buoys, Daily, Latent Heat Flux

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has daily Latent Heat Flux data from the TAO/TRITON (Pacific Ocean, http://www.pmel.noaa.gov/tao/), RAMA (Indian Ocean,...

  9. TAO/TRITON, RAMA, and PIRATA Buoys, Monthly, Latent Heat Flux

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has monthly Latent Heat Flux data from the TAO/TRITON (Pacific Ocean, http://www.pmel.noaa.gov/tao/), RAMA (Indian Ocean,...

  10. TAO/TRITON, RAMA, and PIRATA Buoys, 5-Day, Latent Heat Flux

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has 5-day Latent Heat Flux data from the TAO/TRITON (Pacific Ocean, http://www.pmel.noaa.gov/tao/), RAMA (Indian Ocean,...

  11. Latent and Active Tuberculosis Infection Increase Immune Activation in Individuals Co-Infected with HIV

    Directory of Open Access Journals (Sweden)

    Zuri A. Sullivan

    2015-04-01

    Significance: Latent tuberculosis, which affects an estimated 1/3 of the world's population, has long been thought to be a relatively benign, quiescent state of M. tuberculosis infection. While HIV co-infection is known to exacerbate M. tuberculosis infection and increase the risk of developing active TB, little is known about the potential effect of latent TB infection on HIV disease. This study shows that HIV-infected individuals with both active and latent TB have elevated levels of inflammation and immune activation, biomarkers of HIV disease progression and elevated risk of mortality. These results suggest that, in the context of HIV, latent TB infection may be associated with increased risk of progression to AIDS and mortality.

  12. TAO/TRITON, RAMA, and PIRATA Buoys, Quarterly, Latent Heat Flux

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has quarterly Latent Heat Flux data from the TAO/TRITON (Pacific Ocean, http://www.pmel.noaa.gov/tao/), RAMA (Indian Ocean,...

  13. The Latent Class Model as a Measurement Model for Situational Judgment Tests

    Directory of Open Access Journals (Sweden)

    Frank Rijmen

    2011-11-01

    Full Text Available In a situational judgment test, it is often debatable what constitutes a correct answer to a situation. There is currently a multitude of scoring procedures. Establishing a measurement model can guide the selection of a scoring rule. It is argued that the latent class model is a good candidate for a measurement model. Two latent class models are applied to the Managing Emotions subtest of the Mayer, Salovey, Caruso Emotional Intelligence Test: a plain-vanilla latent class model, and a second-order latent class model that takes into account the clustering of several possible reactions within each hypothetical scenario of the situational judgment test. The results for both models indicated that there were three subgroups characterised by the degree to which differentiation occurred between possible reactions in terms of perceived effectiveness. Furthermore, the results for the second-order model indicated a moderate cluster effect.

  14. Latent curing systems stabilized by reaction equilibrium in homogeneous mixtures of benzoxazine and amine

    Science.gov (United States)

    Wang, Jun; Xu, Ya Zhen; Fu, Ya Fei; Liu, Xiang Dong

    2016-12-01

    Latent curing systems are widely used in industrial thermosets in applications such as adhesion, coating, and composites. Despite many attempts to improve the practicality of this dormant reaction system, the majority of commercially available latent products still use particulate hardeners or liquid compounds with blocked active groups. These formulations generally lack fluidity or rapid reaction characteristics and thus are problematic in some industry applications. Here we describe a novel concept that stabilizes highly reactive benzoxazine/amine mixtures by reaction equilibrium. These new latent benzoxazine curing systems have a long storable lifetime but very short gel time at 150 °C. The reversible reaction between benzoxazine and amine is further demonstrated by FT-IR spectral measurements and rheological experiments, and it is shown that the overall characteristics of the latent system are promising for many industrial applications.

  15. Convective heat transfer characters of nanoparticle enhanced latent functionally thermal fluid

    Institute of Scientific and Technical Information of China (English)

    WANG Liang; LIN GuiPing; CHEN HaiSheng; DING YuLong

    2009-01-01

    The latent heat of the microencapsulated phase change material (MPCM) increases the effective ther-mal capacity of latent functionally thermal fluid. However, researchers found that the heat transfer performance of such fluids was diminished due to the reduction of the low thermal conductivity of MPCM. For this reason, the nanoparticle enhanced latent functionally thermal fluids were formulated and the heat transfer behaviors of these fluids in a vertical circular tube at the laminar regime were conducted. The result showed that slurries containing 0.5% TiO2 nanoparticles by mass and 5%-20% MPCM by mass exhibited improved heat transfer rates in comparison with the conventional latent functionally thermal fluid and that the enhancement increased with the increasing MPCM concentration and up to 18.9% of the dimensionless wall temperature was reduced.

  16. Visualization of latent fingerprint corrosion on a discharged brass shell casing.

    Science.gov (United States)

    Bond, John W; Heidel, Chuck

    2009-07-01

    Latent fingerprint visualization on discharged shell casings can provide good forensic evidence, particularly if the casing is recovered at the scene of a crime where a firearm has been discharged. Unfortunately, visualization of such latent fingerprints when they were deposited prior to discharge of the firearm is problematic as both increased temperature and abrasive friction can inhibit fingerprint visualization with conventional techniques. We present a case study that demonstrates latent fingerprint visualization on a discharged shell casing recovered 14 years ago from the scene of a homicide. Previous cyanoacrylate fuming of the casing had failed to reveal any fingerprints. We use a visualization technique in which a conducting carbon powder adheres preferentially to latent fingerprint corrosion of the casing surface, following the application of a potential of 2.5 kV to the casing. This technique presents opportunities for the review of old cases and for consideration of its use in current cases.

  17. Active and latent tuberculosis in prisoners in the Central-West Region of Brazil

    Directory of Open Access Journals (Sweden)

    Anderson Oliveira Estevan

    2013-07-01

    Full Text Available Introduction Jailed populations exhibit high rates of tuberculosis (TB infection and active disease. Methods A cross-sectional study was performed to estimate the prevalence of latent and active TB and to identify factors associated with latent infection in inmates. Results The prevalence of latent TB was 49%, and the prevalence of active TB was 0.4%. The presence of a Bacille Calmette-Guérin (BCG scar (prevalence ratio (PR=1.65; 95% confidence interval (CI: 1.09-2.50; p=0.0162 and the World Health Organization (WHO score for active TB in prisons (PR=1.07; 95% CI: 1.01-1.14; p=0.0181 were correlated with infection. Conclusions The identification of associated factors and the prevalence of latent and active TB allows the development of plans to control this disease in jails.

  18. The latent structure of attention deficit/hyperactivity disorder in an adult sample.

    Science.gov (United States)

    Marcus, David K; Norris, Alyssa L; Coccaro, Emil F

    2012-06-01

    The vast majority of studies that have examined the latent structure of attention deficit/hyperactivity disorder (ADHD) in children and adolescents have concluded that ADHD has a dimensional latent structure. In other words, ADHD symptomatology exists along a continuum and there is no natural boundary or qualitative distinction (i.e., taxon) separating youth with ADHD from those with subclinical inattention or hyperactivity/impulsivity problems. Although adult ADHD appears to be less prevalent than ADHD in youth (which could suggest a more severe adult ADHD taxon), researchers have yet to examine the latent structure of ADHD in adults. The present study used a sample (N = 600) of adults who completed a self-report measure of ADHD symptoms. The taxometric analyses revealed a dimensional latent structure for inattention, hyperactivity/impulsivity, and ADHD. These findings are consistent with previous taxometric studies that examined ADHD in children and adolescents, and with contemporary polygenic and multifactorial models of ADHD.

  19. Latent variable modeling%建立隐性变量模型

    Institute of Scientific and Technical Information of China (English)

    蔡力

    2012-01-01

    @@ A latent variable model, as the name suggests,is a statistical model that contains latent, that is, unobserved, variables.Their roots go back to Spearman's 1904 seminal work[1] on factor analysis,which is arguably the first well-articulated latent variable model to be widely used in psychology, mental health research, and allied disciplines.Because of the association of factor analysis with early studies of human intelligence, the fact that key variables in a statistical model are, on occasion, unobserved has been a point of lingering contention and controversy.The reader is assured, however, that a latent variable,defined in the broadest manner, is no more mysterious than an error term in a normal theory linear regression model or a random effect in a mixed model.

  20. Amino-terminal pro-brain natriuretic peptide in children with latent rheumatic heart disease

    Directory of Open Access Journals (Sweden)

    Justin P Zachariah

    2016-01-01

    Conclusion: Serum NT-proBNP did not distinguish between latent RHD cases and the controls. Sex and within-family exposures may confound this result. More investigation into biomarker-based RHD detection is warranted.

  1. The role of latent heat in kinetic energy conversions of South Pacific cyclones

    Science.gov (United States)

    Kann, Deirdre M.; Vincent, Dayton G.

    1986-01-01

    The four-dimensional behavior of cyclone systems in the South Pacific Convergence Zone (SPCZ) is analyzed. Three cyclone systems, which occurred during the period from January 10-16, 1979, are examined using the data collected during the first special observing period of the FGGE. The effects of latent heating on the life cycles of the cyclones are investigated. Particular attention is given to the conversions of eddy available potential energy to eddy kinetic energy and of mean kinetic energy to eddy kinetic energy. The net radiation profile, sensible heat flux, total field of vertical motion, and latent heat component were computed. The life cycles of the cyclones are described. It is observed that the latent heating component accounts for nearly all the conversion in the three cyclones, and latent heating within the SPCZ is the major source of eddy kinetic energy for the cyclones.

  2. Designed, synthetically accessible bryostatin analogues potently induce activation of latent HIV reservoirs in vitro

    Science.gov (United States)

    Dechristopher, Brian A.; Loy, Brian A.; Marsden, Matthew D.; Schrier, Adam J.; Zack, Jerome A.; Wender, Paul A.

    2012-09-01

    Bryostatin is a unique lead in the development of potentially transformative therapies for cancer, Alzheimer's disease and the eradication of HIV/AIDS. However, the clinical use of bryostatin has been hampered by its limited supply, difficulties in accessing clinically relevant derivatives, and side effects. Here, we address these problems through the step-economical syntheses of seven members of a new family of designed bryostatin analogues using a highly convergent Prins-macrocyclization strategy. We also demonstrate for the first time that such analogues effectively induce latent HIV activation in vitro with potencies similar to or better than bryostatin. Significantly, these analogues are up to 1,000-fold more potent in inducing latent HIV expression than prostratin, the current clinical candidate for latent virus induction. This study provides the first demonstration that designed, synthetically accessible bryostatin analogues could serve as superior candidates for the eradication of HIV/AIDS through induction of latent viral reservoirs in conjunction with current antiretroviral therapy.

  3. Convective heat transfer characters of nanoparticle enhanced latent functionally thermal fluid

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The latent heat of the microencapsulated phase change material(MPCM)increases the effective ther-mal capacity of latent functionally thermal fluid.However,researchers found that the heat transfer performance of such fluids was diminished due to the reduction of the low thermal conductivity of MPCM.For this reason,the nanoparticle enhanced latent functionally thermal fluids were formulated and the heat transfer behaviors of these fluids in a vertical circular tube at the laminar regime were conducted.The result showed that slurries containing 0.5% TiO2 nanoparticles by mass and 5%―20% MPCM by mass exhibited improved heat transfer rates in comparison with the conventional latent functionally thermal fluid and that the enhancement increased with the increasing MPCM concentration and up to 18.9% of the dimensionless wall temperature was reduced.

  4. Dorsal hippocampal lesions impair blocking but not latent inhibition of taste aversion learning in rats.

    Science.gov (United States)

    Gallo, M; Cándido, A

    1995-06-01

    The aim of the present experiments was to study the effect of nonselective electrolytic lesions of the rat dorsal hippocampus on 2 learning phenomena: the L.J. Kamin (1969) blocking effect and latent inhibition of taste aversion learning. Bilateral dorsal hippocampal lesions selectively impaired blocking induced by 1 saccharin-lithium chloride pairing previous to 1 serial compound (saccharin-cider vinegar)-lithium pairing, but lesions had no effect on latent inhibition of a saline aversion, induced by 6 saline preexposures, in the same group of animals. Moreover, dorsal hippocampal lesions did not affect latent inhibition of saccharin-conditioned aversion induced by 1 or 6 preexposures. It is argued that blocking and latent inhibition of taste aversion learning do not share a common neural mechanism.

  5. Job performance over time is a function of latent trajectories and previous performance.

    Science.gov (United States)

    Zyphur, Michael J; Chaturvedi, Sankalp; Arvey, Richard D

    2008-01-01

    Previous literature addressing job performance over time notes that past performance can affect future performance and that individuals often have distinct latent performance trajectories. However, no research to date has modeled these 2 aspects of job performance in tandem. Drawing on previous literature, the authors note that current performance may act as performance feedback, influencing future performance directly (i.e., autoregression), and that individuals differ in their performance trajectories due to individual-difference factors (i.e., latent trajectories). The authors demonstrate an autoregressive latent trajectory (ALT) model to show how both autoregressive and latent trajectory parameters may be incorporated in modeling job performance over time. Also discussed are the implications of the ALT model for future studies examining job performance longitudinally.

  6. Latent variable models an introduction to factor, path, and structural equation analysis

    CERN Document Server

    Loehlin, John C

    2004-01-01

    This fourth edition introduces multiple-latent variable models by utilizing path diagrams to explain the underlying relationships in the models. The book is intended for advanced students and researchers in the areas of social, educational, clinical, ind

  7. New developing reagent for latent fingermark visualization: Fuller’s earth (Multani Mitti

    Directory of Open Access Journals (Sweden)

    Pallavi Thakur

    2016-12-01

    Full Text Available A number of methods have been reported in the literature for the development of latent fingermarks on different surfaces. This paper reports a new and simple powdering method which is non-toxic and has been employed on different substrates successfully for the development and visualization of latent fingermarks up to the time period of 6 days in varying temperature conditions. In this investigation a less expensive, simple and easily available fuller’s earth (Multani Mitti powder has been used to decipher the latent fingermarks on different substrates namely black cardboard box, clear glass, coverslip box, steel surface, laminated wooden sheet, clear plastic, colored plastic bag and surface of highlighter pen. It is observed that it gives very clear results on majority of substrates and can be successfully used for the development and visualization of latent fingermarks.

  8. Conditioned and Latent Inhibition in Taste-Aversion Learning: Clarifying the Role of Learned Safety

    Science.gov (United States)

    Best, Michael R.

    1975-01-01

    The following experiments are an attempt to clarify the role of learned safety by investigating the applicability of the concept of conditioned inhibition to a taste-aversion procedure and by differentiating its effects fromthose of latent inhibition. (Author)

  9. Attenuation of the Latent Inhibition Effect by Prior Exposure to Another Stimulus

    Science.gov (United States)

    Rudy, Jerry W.; And Others

    1976-01-01

    Repeated, isolated presentations of a stimulus typically reduce the subsequent ability of that cue to become an effective conditioned stimulus. This phenomenon is known as the latent inhibition effect. Four experiments investigate this effect. (Editor/RK)

  10. Synthesis and characterization of multicolour fluorescent nanoparticles for latent fingerprint detection

    Indian Academy of Sciences (India)

    G A SOBRAL Jr; M A GOMES; Z S MACEDO; M A R C ALENCAR; S M V NOVAIS

    2016-10-01

    In this study, we successfully developed Y$_2$O$_3$ nanoparticles doped with Tb$^{3+}$ and Eu$^{3+}$ ions to generate fluorescent images of latent fingerprints. The optical and structural characterization of the nanoparticles was carried out and the fluorescence mechanisms are discussed. In our studies, the developed nanoparticles were effective in producing fluorescent images of latent fingerprints in shades of green, red and yellow with high-contrast colour under ultraviolet lighting.

  11. Inflation, monetary policy and stock market conditions: quantitative evidence from a hybrid latent-variable VAR

    OpenAIRE

    Bordo, Michael D.; Dueker, Michael J.; David C. Wheelock

    2009-01-01

    This paper examines the association between inflation, monetary policy and U.S. stock market conditions during the second half of the 20th century. We use a latent-variable VAR to estimate the impact of inflation and other macroeconomic shocks on a latent index of stock market conditions. Our objective is to investigate the extent to which various shocks contribute to changes in market conditions, above and beyond their direct effects on real stock prices. We find that disinflation shocks pro...

  12. Factors Affecting Medication Adherence among Vietnamese Immigrants with Latent Tuberculosis Infection: A Mixed Design

    OpenAIRE

    Nguyen Truax, Fayette Khue

    2016-01-01

    ABSTRACT OF THE DISSERTATIONFactors Affecting Medication Adherence among Vietnamese Immigrantswith Latent Tuberculosis Infection: A Mixed DesignbyFayette Nguyen TruaxDoctor of Philosophy in NursingUniversity of California, Los Angeles, 2016Professor Adeline M. Nyamathi, Chair Completion of latent tuberculosis infection (LTBI) treatment among foreign-born Asians in the United States (US) is suboptimal, thus leading to high rates of reactivation tuberculosis (TB) among this population. Approxi...

  13. Latent Class Analysis of Differential Item Functioning on the Peabody Picture Vocabulary Test-III

    Science.gov (United States)

    Webb, Mi-young Lee; Cohen, Allan S.; Schwanenflugel, Paula J.

    2008-01-01

    This study investigated the use of latent class analysis for the detection of differences in item functioning on the Peabody Picture Vocabulary Test-Third Edition (PPVT-III). A two-class solution for a latent class model appeared to be defined in part by ability because Class 1 was lower in ability than Class 2 on both the PPVT-III and the…

  14. PET CT Identifies Reactivation Risk in Cynomolgus Macaques with Latent M. tuberculosis

    Science.gov (United States)

    Lin, Philana Ling; Maiello, Pauline; Gideon, Hannah P.; Cadena, Anthony M.; Rodgers, Mark A.; Gregg, Robert; O’Malley, Melanie; Fillmore, Daniel; Frye, L. James; Rutledge, Tara; DiFazio, Robert M.; Janssen, Christopher; Klein, Edwin; Andersen, Peter L.; Fortune, Sarah M.; Flynn, JoAnne L.

    2016-01-01

    Mycobacterium tuberculosis infection presents across a spectrum in humans, from latent infection to active tuberculosis. Among those with latent tuberculosis, it is now recognized that there is also a spectrum of infection and this likely contributes to the variable risk of reactivation tuberculosis. Here, functional imaging with 18F-fluorodeoxygluose positron emission tomography and computed tomography (PET CT) of cynomolgus macaques with latent M. tuberculosis infection was used to characterize the features of reactivation after tumor necrosis factor (TNF) neutralization and determine which imaging characteristics before TNF neutralization distinguish reactivation risk. PET CT was performed on latently infected macaques (n = 26) before and during the course of TNF neutralization and a separate set of latently infected controls (n = 25). Reactivation occurred in 50% of the latently infected animals receiving TNF neutralizing antibody defined as development of at least one new granuloma in adjacent or distant locations including extrapulmonary sites. Increased lung inflammation measured by PET and the presence of extrapulmonary involvement before TNF neutralization predicted reactivation with 92% sensitivity and specificity. To define the biologic features associated with risk of reactivation, we used these PET CT parameters to identify latently infected animals at high risk for reactivation. High risk animals had higher cumulative lung bacterial burden and higher maximum lesional bacterial burdens, and more T cells producing IL-2, IL-10 and IL-17 in lung granulomas as compared to low risk macaques. In total, these data support that risk of reactivation is associated with lung inflammation and higher bacterial burden in macaques with latent Mtb infection. PMID:27379816

  15. PET CT Identifies Reactivation Risk in Cynomolgus Macaques with Latent M. tuberculosis.

    Directory of Open Access Journals (Sweden)

    Philana Ling Lin

    2016-07-01

    Full Text Available Mycobacterium tuberculosis infection presents across a spectrum in humans, from latent infection to active tuberculosis. Among those with latent tuberculosis, it is now recognized that there is also a spectrum of infection and this likely contributes to the variable risk of reactivation tuberculosis. Here, functional imaging with 18F-fluorodeoxygluose positron emission tomography and computed tomography (PET CT of cynomolgus macaques with latent M. tuberculosis infection was used to characterize the features of reactivation after tumor necrosis factor (TNF neutralization and determine which imaging characteristics before TNF neutralization distinguish reactivation risk. PET CT was performed on latently infected macaques (n = 26 before and during the course of TNF neutralization and a separate set of latently infected controls (n = 25. Reactivation occurred in 50% of the latently infected animals receiving TNF neutralizing antibody defined as development of at least one new granuloma in adjacent or distant locations including extrapulmonary sites. Increased lung inflammation measured by PET and the presence of extrapulmonary involvement before TNF neutralization predicted reactivation with 92% sensitivity and specificity. To define the biologic features associated with risk of reactivation, we used these PET CT parameters to identify latently infected animals at high risk for reactivation. High risk animals had higher cumulative lung bacterial burden and higher maximum lesional bacterial burdens, and more T cells producing IL-2, IL-10 and IL-17 in lung granulomas as compared to low risk macaques. In total, these data support that risk of reactivation is associated with lung inflammation and higher bacterial burden in macaques with latent Mtb infection.

  16. A Retrieval of Tropical Latent Heating Using the 3D Structure of Precipitation Features

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Fiaz; Schumacher, Courtney; Feng, Zhe; Hagos, Samson

    2016-09-01

    Traditionally, radar-based latent heating retrievals use rainfall to estimate the total column-integrated latent heating and then distribute that heating in the vertical using a model-based look-up table (LUT). In this study, we develop a new method that uses size characteristics of radar-observed precipitating echo (i.e., area and mean echo-top height) to estimate the vertical structure of latent heating. This technique (named the Convective-Stratiform Area [CSA] algorithm) builds on the fact that the shape and magnitude of latent heating profiles are dependent on the organization of convective systems and aims to avoid some of the pitfalls involved in retrieving accurate rainfall amounts and microphysical information from radars and models. The CSA LUTs are based on a high-resolution Weather Research and Forecasting model (WRF) simulation whose domain spans much of the near-equatorial Indian Ocean. When applied to S-PolKa radar observations collected during the DYNAMO/CINDY2011/AMIE field campaign, the CSA retrieval compares well to heating profiles from a sounding-based budget analysis and improves upon a simple rain-based latent heating retrieval. The CSA LUTs also highlight the fact that convective latent heating increases in magnitude and height as cluster area and echo-top heights grow, with a notable congestus signature of cooling at mid levels. Stratiform latent heating is less dependent on echo-top height, but is strongly linked to area. Unrealistic latent heating profiles in the stratiform LUT, viz., a low-level heating spike, an elevated melting layer, and net column cooling were identified and corrected for. These issues highlight the need for improvement in model parameterizations, particularly in linking microphysical phase changes to larger mesoscale processes.

  17. PET CT Identifies Reactivation Risk in Cynomolgus Macaques with Latent M. tuberculosis.

    Science.gov (United States)

    Lin, Philana Ling; Maiello, Pauline; Gideon, Hannah P; Coleman, M Teresa; Cadena, Anthony M; Rodgers, Mark A; Gregg, Robert; O'Malley, Melanie; Tomko, Jaime; Fillmore, Daniel; Frye, L James; Rutledge, Tara; DiFazio, Robert M; Janssen, Christopher; Klein, Edwin; Andersen, Peter L; Fortune, Sarah M; Flynn, JoAnne L

    2016-07-01

    Mycobacterium tuberculosis infection presents across a spectrum in humans, from latent infection to active tuberculosis. Among those with latent tuberculosis, it is now recognized that there is also a spectrum of infection and this likely contributes to the variable risk of reactivation tuberculosis. Here, functional imaging with 18F-fluorodeoxygluose positron emission tomography and computed tomography (PET CT) of cynomolgus macaques with latent M. tuberculosis infection was used to characterize the features of reactivation after tumor necrosis factor (TNF) neutralization and determine which imaging characteristics before TNF neutralization distinguish reactivation risk. PET CT was performed on latently infected macaques (n = 26) before and during the course of TNF neutralization and a separate set of latently infected controls (n = 25). Reactivation occurred in 50% of the latently infected animals receiving TNF neutralizing antibody defined as development of at least one new granuloma in adjacent or distant locations including extrapulmonary sites. Increased lung inflammation measured by PET and the presence of extrapulmonary involvement before TNF neutralization predicted reactivation with 92% sensitivity and specificity. To define the biologic features associated with risk of reactivation, we used these PET CT parameters to identify latently infected animals at high risk for reactivation. High risk animals had higher cumulative lung bacterial burden and higher maximum lesional bacterial burdens, and more T cells producing IL-2, IL-10 and IL-17 in lung granulomas as compared to low risk macaques. In total, these data support that risk of reactivation is associated with lung inflammation and higher bacterial burden in macaques with latent Mtb infection.

  18. Prevalence of latent Mycobacterium tuberculosis infection among professionals of the primary healthcare network

    OpenAIRE

    Tássia Silvana Borges; Eduardo Chaida Sonda; Alexandre Daronco; Fabiana Battisti; Marcos Moura Baptista Dos Santos; Andréia Rosane de Moura Valim; Mariana Valença; Lia Gonçalves Possuelo

    2014-01-01

    Objective: To estimate the prevalence of latent M. tuberculosis infection and identify characteristics related to latent infection among workers of the primary healthcare network.Methods: Cross-sectional, observational and descriptive study, conducted in 2011, included 137 basic health workers who performed their activities in a municipality. Interviews were carried out addressing characteristics of exposure at work (BCG vaccination, length of time working in the health system, potential expo...

  19. Induction of muscle cramps by nociceptive stimulation of latent myofascial trigger points.

    Science.gov (United States)

    Ge, Hong-You; Zhang, Yang; Boudreau, Shellie; Yue, Shou-Wei; Arendt-Nielsen, Lars

    2008-06-01

    The aim of this present study is to test the hypothesis that nociceptive stimulation of latent myofascial trigger points (MTrPs) increases the occurrence of local muscle cramps. Nociceptive muscle stimulation was obtained by a bolus injection of glutamate (0.1 ml, 0.5 M) into a latent MTrP and a control point (a non-MTrP) located in the right or left gastrocnemius medialis muscles in 14 healthy subjects. A bolus of isotonic saline (0.9%, 0.1 ml) injection served as a control. The injections were guided by intramuscular electromyography (EMG) showing resting spontaneous electrical activity at a latent MTrP and no such activity at a non-MTrP. Intramuscular and surface EMG activities in the gastrocnemius medialis muscle were recorded pre-, during-, and post-injection for a period of 8 min to monitor the occurrence of muscle cramps, which are characterized by a brief episodic burst of high levels of EMG activity. The results showed that glutamate and isotonic saline injections into the latent MTrPs induced higher peak pain intensity than into the non-MTrPs (both P < 0.05). Glutamate injection induced higher peak pain intensity than isotonic saline injection into either latent MTrPs or non-MTrPs (both P < 0.05). Muscle camps were observed in 92.86% of the subjects following glutamate injection into the latent MTrPs, but not into the non-MTrPs (P < 0.001). No muscle cramps were recorded following isotonic saline injection into either the latent MTrPs or the non-MTrPs. These results suggest that latent MTrPs could be involved in the genesis of muscle cramps. Focal increase in nociceptive sensitivity at MTrPs constitutes one of the mechanisms underlying muscle cramps.

  20. Latent Inhibition of US Signal Value Following CS-US Training

    OpenAIRE

    Goddard, Murray J.

    2004-01-01

    Two experiments with rats examined latent inhibition of unconditioned stimulus (US) signal value. In Experiment 1, latent inhibition (LI) rats showed attenuated conditioning, compared to control (C) rats, when a single food pellet, delivered 10 min into a session, was followed by three additional pellets. In preexposure, one pellet had been delivered 10 min into the session (in Group LI), or placed into the magazine at the beginning of the session (in Group C). Experiment 2 replicated Experim...

  1. Error Correction in Latent Inhibition and its Disruption by Opioid Receptor Blockade with Naloxone

    OpenAIRE

    Leung, Hiu T; Killcross, A S; Westbrook, R. Frederick

    2013-01-01

    Latent inhibition refers to the retardation in the development of conditioned responding when a pre-exposed stimulus is used to signal an unconditioned stimulus. This effect is described by error-correction models as an attentional deficit and is commonly used as an animal model of schizophrenia. A series of experiments studied the role of error-correction mechanism in latent inhibition and its interaction with the endogenous opioid system. Systemic administration of the competitive opioid re...

  2. Extending dynamic segmentation with lead generation: A latent class Markov analysis of financial product portfolios

    OpenAIRE

    Paas, L.J.; Bijmolt, T.H.A.; Vermunt, J.K.

    2004-01-01

    A recent development in marketing research concerns the incorporation of dynamics in consumer segmentation.This paper extends the latent class Markov model, a suitable technique for conducting dynamic segmentation, in order to facilitate lead generation.We demonstrate the application of the latent Markov model for these purposes using a database containing information on the ownership of twelve financial products and demographics for explaining (changes in) consumer product portfolios.Data we...

  3. del Norte

    Directory of Open Access Journals (Sweden)

    Heydi Robles

    2005-01-01

    Full Text Available Este artículo muestra los resultados de una investigación sobre la ansiedad causada por el aprendizaje de idiomas. Está centrado en la ansiedad relacionada con la habilidad de producción oral. El objetivo del estudio era identificar los factores externos que producen ansiedad en el desarrollo de la competencia oral en un grupo de estudiantes de Psicología. Para lograr su objetivo, la investigación utilizó diarios, cuestionarios, grabaciones (opiniones personales, presentaciones orales breves y entrevistas. Con respecto de los factores externos que producen ansiedad en relación con las actividades, los resultados muestran que todas las actividades orales producen un alto grado de ansiedades en los estudiantes, especialmente las actividades no programadas. También muestran una falta de participación en clase con un fuerte rechazo a las actividades orales. Entre las posibles causas de reticencia puede estar el hecho de que los estudiantes no quieren ser objeto de burla. Además, la habilidad de producción oral no fue estimulada en los niveles anteriores del programa de inglés. Es vital mencionar que los alumnos son conscientes de sus carencias en algunos aspectos del idioma como vocabulario, gramática y fluidez.

  4. The detection of drugs of abuse in fingerprints using Raman spectroscopy I: latent fingerprints

    Science.gov (United States)

    Day, Joanna S.; Edwards, Howell G. M.; Dobrowski, Steven A.; Voice, Alison M.

    2004-02-01

    This paper describes the application of Raman spectroscopy to the detection of exogenous substances in latent fingerprints. The scenario considered was that of an individual handling a substance and subsequently depositing a contaminated fingerprint. Five drugs of abuse (codeine phosphate, cocaine hydrochloride, amphetamine sulphate, barbital and nitrazepam) and five non-controlled substances of similar appearance, which may be used in the adulteration of drugs of abuse (caffeine, aspirin, paracetamol, starch and talc), were studied in both sweat-rich and sebum-rich latent fingerprints. The substances studied could be clearly distinguished using their Raman spectra and were all successfully detected in latent fingerprints. Photobleaching was necessary to reduce the fluorescence background in the spectra of some substances. Raman spectra obtained from the substances in sweat-rich latent fingerprints were of a similar quality to spectra that obtained from the substances under normal sampling conditions. Interfering Raman bands arising from latent fingerprint material were present in the spectra obtained from the substances in sebum-rich fingerprints. These bands did not prevent identification of the substances and could be successfully removed by spectral subtraction. The most difficult aspect of the detection of these substances in latent fingerprints was visually locating the substance in the fingerprint in order to obtain a Raman spectrum.

  5. Modeling individual subtests of the WAIS IV with multiple latent factors.

    Science.gov (United States)

    McFarland, Dennis J

    2013-01-01

    Performance on a cognitive test can be viewed either as measuring a unitary function or as reflecting the operation of multiple factors. Individual subtests in batteries designed to measure human abilities are commonly modeled as a single latent factor. Several latent factors are then used to model groups of subtests. However these latent factors are not independent as they are related through hierarchical or oblique structures. As a result, the simple structure of subtest performance results in complex latent factors. The present study used structural equation modeling to evaluate several multidimensional models of the Wechsler Adult Intelligence Scales-fourth edition (WAIS-IV) subtests. Multidimensional models of subtest performance provided better model fit as compared to several previously proposed one dimensional models. These multidimensional models also generalized well to new samples of populations differing in age from that used to estimate the model parameters. Overall these results show that models that describe subtests as multidimensional functions of uncorrelated factors provided a better fit to the WAIS-IV correlations than models that describe subtests as one dimensional functions of correlated factors. There appears to be a trade-off in modeling subtests as one dimensional and modeling with homogeneous latent traits. More consideration should be given to models that include multiple uncorrelated latent factors as determinants of the performance on a given subtest. These results support the view that performance on any given cognitive test is potentially the result of multiple factors. Simple structure may be too simple.

  6. Modeling individual subtests of the WAIS IV with multiple latent factors.

    Directory of Open Access Journals (Sweden)

    Dennis J McFarland

    Full Text Available Performance on a cognitive test can be viewed either as measuring a unitary function or as reflecting the operation of multiple factors. Individual subtests in batteries designed to measure human abilities are commonly modeled as a single latent factor. Several latent factors are then used to model groups of subtests. However these latent factors are not independent as they are related through hierarchical or oblique structures. As a result, the simple structure of subtest performance results in complex latent factors. The present study used structural equation modeling to evaluate several multidimensional models of the Wechsler Adult Intelligence Scales-fourth edition (WAIS-IV subtests. Multidimensional models of subtest performance provided better model fit as compared to several previously proposed one dimensional models. These multidimensional models also generalized well to new samples of populations differing in age from that used to estimate the model parameters. Overall these results show that models that describe subtests as multidimensional functions of uncorrelated factors provided a better fit to the WAIS-IV correlations than models that describe subtests as one dimensional functions of correlated factors. There appears to be a trade-off in modeling subtests as one dimensional and modeling with homogeneous latent traits. More consideration should be given to models that include multiple uncorrelated latent factors as determinants of the performance on a given subtest. These results support the view that performance on any given cognitive test is potentially the result of multiple factors. Simple structure may be too simple.

  7. Original article Latent classes of criminal intent associated with criminal behaviour

    Directory of Open Access Journals (Sweden)

    Daniel Boduszek

    2014-07-01

    Full Text Available Background This study aimed to examine the number of latent classes of criminal intent that exist among prisoners and to look at the associations with recidivism, number of police arrests, type of offending (robbery, violent offences, murder, and multiple offences, and age. Participants and procedure Latent class analysis was used to identify homogeneous subgroups of prisoners based on their responses to the 10 questions reflecting criminal intent. Participants were 309 male recidivistic prisoners incarcerated in a maximum security prison. Multinomial logistic regression was used to interpret the nature of the latent classes, or groups, by estimating the association between recidivism and latent classes of criminal intent while controlling for offence type (robbery, violent offences, murder, and multiple offences, number of arrests, and age. Results The best fitting latent class model was a three-class solution: ‘High criminal intent’ (49.3%, ‘Intermediate criminal intent’ (41.3%, and ‘Low criminal intent’ (9.4%. The latent classes were differentially related to the external variables (recidivism, violent offences, and age. Conclusions Criminal intent is best explained by three homogeneous classes that appear to represent an underlying continuum. Future work is needed to identify whether these distinct classes of criminal intent may predict engagement in various types of criminal behaviour.

  8. Technology of latent-heat recovery for boiler system; Boira ni okeru sennetsu kaishu gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Moriyama, T. [Tokyo Gas Co. Ltd. (Japan)

    1996-08-01

    The boiler has reached the highest degree of completion among combustion equipment and is highly efficient. In order to enhance its efficiency further, it is ordinary to recover the retention heat of the combustion exhaust gas, but due to the problem of low temperature corrosion caused by the sulfur content in fuel resulted from a temperature drop of the exhaust gas, heat recovery has been done not sufficiently. In this article, an example is introduced to plan the betterment of efficiency by application of a latent heat recovering economizer to a sugar manufactory and a report is made on the energy saving effect by recovering the latent heat and a study on the quality of the material for the latent heat reclaimer. The above latent heat reclaimer is a system which takes advantage of the feature of the natural gas reportedly having no sulfur content, brings down the temperature at the outlet of a heat exchanger of the boiler exhaust gas to below the dew point, thereby recovers the condensed latent heat of the vapor in the exhaust gas and utilizes it for heating up the boiler feed water. In this example, the line of an already installed boiler has been partially modified and only a latent heat reclaimer has been installed newly. The increase of efficiency has been as high as 5.28%. 5 figs., 5 tabs.

  9. Prevalence of latent Mycobacterium tuberculosis infection among professionals of the primary healthcare network

    Directory of Open Access Journals (Sweden)

    Tássia Silvana Borges

    2014-06-01

    Full Text Available Objective: To estimate the prevalence of latent M. tuberculosis infection and identify characteristics related to latent infection among workers of the primary healthcare network.Methods: Cross-sectional, observational and descriptive study, conducted in 2011, included 137 basic health workers who performed their activities in a municipality. Interviews were carried out addressing characteristics of exposure at work (BCG vaccination, length of time working in the health system, potential exposure to tuberculosis, HIV infection, use of corticosteroids, diabetes, use of tobacco or alcohol and subsequently performed tuberculin skin test (TST. Data was analyzed with Fischer and Student’s t-test (p < 0.05. Results: Health professionals were mostly women (n=126, 92% with mean age of 35.3 (± 9.1 years. Among the reactors, 25 (55.5% sought medical care, and of these, 7 (28% underwent prophylactic treatment. The prevalence of latent tuberculosis was 32.8%. Of the characteristics evaluated, only smoking (OR 3.03; 95%CI 1.05-8.77 was associated with latent infection. Conclusion: The estimated prevalence of latent M. tuberculosis infection among the evaluated health workers was 32.8%. As for the characteristics studied, it was not possible to relate them to latent infection among workers in primary healthcare network, with the exception of the smoking habit. doi: 10.5020/18061230.2014.p269

  10. Error correction in latent inhibition and its disruption by opioid receptor blockade with naloxone.

    Science.gov (United States)

    Leung, Hiu T; Killcross, A S; Westbrook, R Frederick

    2013-11-01

    Latent inhibition refers to the retardation in the development of conditioned responding when a pre-exposed stimulus is used to signal an unconditioned stimulus. This effect is described by error-correction models as an attentional deficit and is commonly used as an animal model of schizophrenia. A series of experiments studied the role of error-correction mechanism in latent inhibition and its interaction with the endogenous opioid system. Systemic administration of the competitive opioid receptor antagonist naloxone before rats were pre-exposed to a target stimulus prevented latent inhibition of its subsequent fear conditioning; it was without effect on a non-pre-exposed stimulus and did not produce state-dependent learning (Experiments 1a and 1b). Naloxone did not reverse the latent inhibitory effect already accrued to a pre-exposed target. However, it did prevent the enhancement of latent inhibition by a long retention interval interpolated between its initial exposure and re-exposure (Experiment 2) or by a novel stimulus compounded with the pre-exposed target during re-exposure (Experiment 3). These results provide evidence that attentional loss in latent inhibition is instructed by an opioid-mediated error signal which diminishes with repeated stimulus exposures but recovers with the passage of time or reintroduction of novelty.

  11. A Latent Class Analysis of Heterosexual Young Men's Masculinities.

    Science.gov (United States)

    Casey, Erin A; Masters, N Tatiana; Beadnell, Blair; Wells, Elizabeth A; Morrison, Diane M; Hoppe, Marilyn J

    2016-07-01

    Parallel bodies of research have described the diverse and complex ways that men understand and construct their masculine identities (often termed "masculinities") and, separately, how adherence to traditional notions of masculinity places men at risk for negative sexual and health outcomes. The goal of this analysis was to bring together these two streams of inquiry. Using data from a national, online sample of 555 heterosexually active young men, we employed latent class analysis (LCA) to detect patterns of masculine identities based on men's endorsement of behavioral and attitudinal indicators of "dominant" masculinity, including sexual attitudes and behaviors. LCA identified four conceptually distinct masculine identity profiles. Two groups, termed the Normative and Normative/Male Activities groups, respectively, constituted 88 % of the sample and were characterized by low levels of adherence to attitudes, sexual scripts, and behaviors consistent with "dominant" masculinity, but differed in their levels of engagement in male-oriented activities (e.g., sports teams). Only eight percent of the sample comprised a masculinity profile consistent with "traditional" ideas about masculinity; this group was labeled Misogynistic because of high levels of sexual assault and violence toward female partners. The remaining four percent constituted a Sex-Focused group, characterized by high numbers of sexual partners, but relatively low endorsement of other indicators of traditional masculinity. Follow-up analyses showed a small number of differences across groups on sexual and substance use health indicators. Findings have implications for sexual and behavioral health interventions and suggest that very few young men embody or endorse rigidly traditional forms of masculinity.

  12. Latent heat exchange in the boreal and arctic biomes.

    Science.gov (United States)

    Kasurinen, Ville; Alfredsen, Knut; Kolari, Pasi; Mammarella, Ivan; Alekseychik, Pavel; Rinne, Janne; Vesala, Timo; Bernier, Pierre; Boike, Julia; Langer, Moritz; Belelli Marchesini, Luca; van Huissteden, Ko; Dolman, Han; Sachs, Torsten; Ohta, Takeshi; Varlagin, Andrej; Rocha, Adrian; Arain, Altaf; Oechel, Walter; Lund, Magnus; Grelle, Achim; Lindroth, Anders; Black, Andy; Aurela, Mika; Laurila, Tuomas; Lohila, Annalea; Berninger, Frank

    2014-11-01

    In this study latent heat flux (λE) measurements made at 65 boreal and arctic eddy-covariance (EC) sites were analyses by using the Penman-Monteith equation. Sites were stratified into nine different ecosystem types: harvested and burnt forest areas, pine forests, spruce or fir forests, Douglas-fir forests, broadleaf deciduous forests, larch forests, wetlands, tundra and natural grasslands. The Penman-Monteith equation was calibrated with variable surface resistances against half-hourly eddy-covariance data and clear differences between ecosystem types were observed. Based on the modeled behavior of surface and aerodynamic resistances, surface resistance tightly control λE in most mature forests, while it had less importance in ecosystems having shorter vegetation like young or recently harvested forests, grasslands, wetlands and tundra. The parameters of the Penman-Monteith equation were clearly different for winter and summer conditions, indicating that phenological effects on surface resistance are important. We also compared the simulated λE of different ecosystem types under meteorological conditions at one site. Values of λE varied between 15% and 38% of the net radiation in the simulations with mean ecosystem parameters. In general, the simulations suggest that λE is higher from forested ecosystems than from grasslands, wetlands or tundra-type ecosystems. Forests showed usually a tighter stomatal control of λE as indicated by a pronounced sensitivity of surface resistance to atmospheric vapor pressure deficit. Nevertheless, the surface resistance of forests was lower than for open vegetation types including wetlands. Tundra and wetlands had higher surface resistances, which were less sensitive to vapor pressure deficits. The results indicate that the variation in surface resistance within and between different vegetation types might play a significant role in energy exchange between terrestrial ecosystems and atmosphere. These results suggest the need

  13. Multiple latent viruses reactivate in astronauts during Space Shuttle missions.

    Science.gov (United States)

    Mehta, S K; Laudenslager, M L; Stowe, R P; Crucian, B E; Sams, C F; Pierson, D L

    2014-10-01

    Latent virus reactivation and diurnal salivary cortisol and dehydroepiandrosterone were measured prospectively in 17 astronauts (16 male and 1 female) before, during, and after short-duration (12-16 days) Space Shuttle missions. Blood, urine, and saliva samples were collected during each of these phases. Antiviral antibodies and viral load (DNA) were measured for Epstein-Barr virus (EBV), varicella-zoster virus (VZV), and cytomegalovirus (CMV). Three astronauts did not shed any virus in any of their samples collected before, during, or after flight. EBV was shed in the saliva in all of the remaining 14 astronauts during all 3 phases of flight. Seven of the 14 EBV-shedding subjects also shed VZV during and after the flight in their saliva samples, and 8 of 14 EBV-shedders also shed CMV in their urine samples before, during, and after flight. In 6 of 14 crewmembers, all 3 target viruses were shed during one or more flight phases. Both EBV and VZV DNA copies were elevated during the flight phase relative to preflight or post-flight levels. EBV DNA in peripheral blood was increased preflight relative to post-flight. Eighteen healthy controls were also included in the study. Approximately 2-5% of controls shed EBV while none shed VZV or CMV. Salivary cortisol measured preflight and during flight were elevated relative to post-flight. In contrast DHEA decreased during the flight phase relative to both preflight and post-flight. As a consequence, the molar ratio of the area under the diurnal curve of cortisol to DHEA with respect to ground (AUCg) increased significantly during flight. This ratio was unrelated to viral shedding. In summary, three herpes viruses can reactivate individually or in combination during spaceflight.

  14. Internet Gamblers Differ on Social Variables: A Latent Class Analysis.

    Science.gov (United States)

    Khazaal, Yasser; Chatton, Anne; Achab, Sophia; Monney, Gregoire; Thorens, Gabriel; Dufour, Magali; Zullino, Daniele; Rothen, Stephane

    2016-12-27

    Online gambling has gained popularity in the last decade, leading to an important shift in how consumers engage in gambling and in the factors related to problem gambling and prevention. Indebtedness and loneliness have previously been associated with problem gambling. The current study aimed to characterize online gamblers in relation to indebtedness, loneliness, and several in-game social behaviors. The data set was obtained from 584 Internet gamblers recruited online through gambling websites and forums. Of these gamblers, 372 participants completed all study assessments and were included in the analyses. Questionnaires included those on sociodemographics and social variables (indebtedness, loneliness, in-game social behaviors), as well as the Gambling Motives Questionnaire, Gambling Related Cognitions Scale, Internet Addiction Test, Problem Gambling Severity Index, Short Depression-Happiness Scale, and UPPS-P Impulsive Behavior Scale. Social variables were explored with a latent class model. The clusters obtained were compared for psychological measures and three clusters were found: lonely indebted gamblers (cluster 1: 6.5%), not lonely not indebted gamblers (cluster 2: 75.4%), and not lonely indebted gamblers (cluster 3: 18%). Participants in clusters 1 and 3 (particularly in cluster 1) were at higher risk of problem gambling than were those in cluster 2. The three groups differed on most assessed variables, including the Problem Gambling Severity Index, the Short Depression-Happiness Scale, and the UPPS-P subscales (except the sensation seeking subscore). Results highlight significant between-group differences, suggesting that Internet gamblers are not a homogeneous group. Specific intervention strategies could be implemented for groups at risk.

  15. Sentiment Detection of Web Users Using Probabilistic Latent Semantic Analysis

    Directory of Open Access Journals (Sweden)

    Weijian Ren

    2014-10-01

    Full Text Available With the wide application of Internet in almost all fields, it has become the most important way for information publication, providing a large number of channels for spreading public opinion. Public opinions, as the response of Internet users to the information such as social events and government policies, reflect the status of both society and economics, which is highly valuable for the decision-making and public relations of enterprises. At present, the analysis methods for Internet public opinion are mainly based on discriminative approaches, such as Support Vector Machine (SVM and neural network. However, when these approaches analyze the sentiment of Internet public opinion, they are failed to exploit information hidden in text, e.g. topic. Motivated by the above observation, this paper proposes a detection method for public sentiment based on Probabilistic Latent Semantic Analysis (PLSA model. PLSA inherits the advantages of LSA, exploiting the semantic topic hidden in data. The procedure of detecting the public sentiment using this algorithm is composed of three main steps: (1 Chinese word segmentation and word refinement, with which each document is represented by a bag of words; (2 modeling the probabilistic distribution of documents using PLSA; (3 using the Z-vector of PLSA as the features of documents and delivering it to SVM for sentiment detection. We collect a set of text data from Weibo, blog, BBS etc. to evaluate our proposed approach. The experimental results shows that the proposed method in this paper can detect the public sentiment with high accuracy, outperforming the state-of-the-art approaches, i.e., word histogram based approach. The results also suggest that, text semantic analysis using PLSA could significantly boost the sentiment detection

  16. MASSIVELY PARALLEL LATENT SEMANTIC ANALYSES USING A GRAPHICS PROCESSING UNIT

    Energy Technology Data Exchange (ETDEWEB)

    Cavanagh, J.; Cui, S.

    2009-01-01

    Latent Semantic Analysis (LSA) aims to reduce the dimensions of large term-document datasets using Singular Value Decomposition. However, with the ever-expanding size of datasets, current implementations are not fast enough to quickly and easily compute the results on a standard PC. A graphics processing unit (GPU) can solve some highly parallel problems much faster than a traditional sequential processor or central processing unit (CPU). Thus, a deployable system using a GPU to speed up large-scale LSA processes would be a much more effective choice (in terms of cost/performance ratio) than using a PC cluster. Due to the GPU’s application-specifi c architecture, harnessing the GPU’s computational prowess for LSA is a great challenge. We presented a parallel LSA implementation on the GPU, using NVIDIA® Compute Unifi ed Device Architecture and Compute Unifi ed Basic Linear Algebra Subprograms software. The performance of this implementation is compared to traditional LSA implementation on a CPU using an optimized Basic Linear Algebra Subprograms library. After implementation, we discovered that the GPU version of the algorithm was twice as fast for large matrices (1 000x1 000 and above) that had dimensions not divisible by 16. For large matrices that did have dimensions divisible by 16, the GPU algorithm ran fi ve to six times faster than the CPU version. The large variation is due to architectural benefi ts of the GPU for matrices divisible by 16. It should be noted that the overall speeds for the CPU version did not vary from relative normal when the matrix dimensions were divisible by 16. Further research is needed in order to produce a fully implementable version of LSA. With that in mind, the research we presented shows that the GPU is a viable option for increasing the speed of LSA, in terms of cost/performance ratio.

  17. Massively Parallel Latent Semantic Analyzes using a Graphics Processing Unit

    Energy Technology Data Exchange (ETDEWEB)

    Cavanagh, Joseph M [ORNL; Cui, Xiaohui [ORNL

    2009-01-01

    Latent Semantic Indexing (LSA) aims to reduce the dimensions of large Term-Document datasets using Singular Value Decomposition. However, with the ever expanding size of data sets, current implementations are not fast enough to quickly and easily compute the results on a standard PC. The Graphics Processing Unit (GPU) can solve some highly parallel problems much faster than the traditional sequential processor (CPU). Thus, a deployable system using a GPU to speedup large-scale LSA processes would be a much more effective choice (in terms of cost/performance ratio) than using a computer cluster. Due to the GPU s application-specific architecture, harnessing the GPU s computational prowess for LSA is a great challenge. We present a parallel LSA implementation on the GPU, using NVIDIA Compute Unified Device Architecture and Compute Unified Basic Linear Algebra Subprograms. The performance of this implementation is compared to traditional LSA implementation on CPU using an optimized Basic Linear Algebra Subprograms library. After implementation, we discovered that the GPU version of the algorithm was twice as fast for large matrices (1000x1000 and above) that had dimensions not divisible by 16. For large matrices that did have dimensions divisible by 16, the GPU algorithm ran five to six times faster than the CPU version. The large variation is due to architectural benefits the GPU has for matrices divisible by 16. It should be noted that the overall speeds for the CPU version did not vary from relative normal when the matrix dimensions were divisible by 16. Further research is needed in order to produce a fully implementable version of LSA. With that in mind, the research we presented shows that the GPU is a viable option for increasing the speed of LSA, in terms of cost/performance ratio.

  18. Benchmarking contactless acquisition sensor reproducibility for latent fingerprint trace evidence

    Science.gov (United States)

    Hildebrandt, Mario; Dittmann, Jana

    2015-03-01

    Optical, nano-meter range, contactless, non-destructive sensor devices are promising acquisition techniques in crime scene trace forensics, e.g. for digitizing latent fingerprint traces. Before new approaches are introduced in crime investigations, innovations need to be positively tested and quality ensured. In this paper we investigate sensor reproducibility by studying different scans from four sensors: two chromatic white light sensors (CWL600/CWL1mm), one confocal laser scanning microscope, and one NIR/VIS/UV reflection spectrometer. Firstly, we perform an intra-sensor reproducibility testing for CWL600 with a privacy conform test set of artificial-sweat printed, computer generated fingerprints. We use 24 different fingerprint patterns as original samples (printing samples/templates) for printing with artificial sweat (physical trace samples) and their acquisition with contactless sensory resulting in 96 sensor images, called scan or acquired samples. The second test set for inter-sensor reproducibility assessment consists of the first three patterns from the first test set, acquired in two consecutive scans using each device. We suggest using a simple feature space set in spatial and frequency domain known from signal processing and test its suitability for six different classifiers classifying scan data into small differences (reproducible) and large differences (non-reproducible). Furthermore, we suggest comparing the classification results with biometric verification scores (calculated with NBIS, with threshold of 40) as biometric reproducibility score. The Bagging classifier is nearly for all cases the most reliable classifier in our experiments and the results are also confirmed with the biometric matching rates.

  19. Latent Autoimmune Diabetes in Adults: a case report.

    Science.gov (United States)

    Bermúdez, Valmore; Aparicio, Daniel; Colmenares, Carlos; Peñaranda, Lianny; Luti, Yettana; Gotera, Daniela; Rojas, Joselyn; Cabrera, Mayela; Reyna, Nadia; Velasco, Manuel; Israili, Zafar H

    2010-01-01

    Latent Autoimmune Diabetes in Adults (LADA) is an autoimmune endocrine disorder in which despite the presence of antipancreatic islets antibodies in the moment of diagnostics, the progression to beta-cell secretory insufficiency is slow. It is often confused with others types of diabetes and therefore the management is frequently inadequate. We report a clinical case of a 23-year-old man with diagnosis of type 2 diabetes since 6 months ago, poorly controlled with a sulfonylurea, who initially presented 2 months ago from polyuria, polydipsia, and asthenia and 6 kg weight loss. History of past illness was negative, however, his mother relates exclusive breastfeeding during the first 15 days of life and later (until the 6 months) he was fed with infant formula (S-26). Family history revealed a first-degree relative (father) with diabetes mellitus secondary to steroid administration due to diagnosis of bone marrow hypoplasia. Also presents second-degree family history (uncle and grandfather) of type 2 diabetes mellitus. There were no pathologic findings at the physical examination. Anthropometry and laboratory tests were as follows: body mass index (BMI) = 19.66 kg/m, basal and postprandial glycemia = 108, and 276 mg/dL respectively, glycated haemoglobin = 8.9%, basal and postprandial C-peptide (2 hours) = 1.9, and 3.2 ng/mL, homeostasis model assessment of beta cell function: 87.5%, homeostasis model assessment of insulin resistance: 1.6. LADA presumptive diagnosis was confirmed with presence of autoantibodies anti-tyrosin-phosphatase and GAD65. At the time of diagnosis, individuals with LADA present an onset age <50, BMI <25 kg/m2, low magnitude postprandial and basal hyperglycemia, normal or close to normal C-peptide values, and thus not occur with acute hyperglycemic crises. Insulin therapy preserves pancreatic b-cell function, at the point that eventually prescribed insulin doses need to be reduced.

  20. Dopamine D1 receptor involvement in latent inhibition and overshadowing.

    Science.gov (United States)

    Nelson, Andrew J D; Thur, Karen E; Cassaday, Helen J

    2012-11-01

    Latent inhibition (LI) manifests as poorer conditioning to a stimulus that has previously been experienced without consequence. There is good evidence of dopaminergic modulation of LI, as the effect is reliably disrupted by the indirect dopamine (DA) agonist amphetamine. The disruptive effects of amphetamine on LI are reversed by both typical and atypical antipsychotics, which on their own are able to facilitate LI. However, the contribution of different DA receptors to these effects is poorly understood. Amphetamine effects on another stimulus selection procedure, overshadowing, have been suggested to be D1-mediated. Thus, in the current experiments, we systematically investigated the role of D1 receptors in LI. First, we tested the ability of the full D1 agonist SKF 81297 to abolish LI and compared the effects of this drug on LI and overshadowing. Subsequently, we examined whether the D1 antagonist SCH 23390 can lead to the emergence of LI under conditions that do not produce the effect in normal animals (weak pre-exposure). Finally, we tested the ability of SCH 23390 to block amphetamine-induced disruption of LI. We found little evidence that direct stimulation of D1 receptors abolishes LI (although there was some attenuation of LI at 0.4 mg/kg SKF 81297). Similarly, SCH 23390 failed to enhance LI. However, SCH 23390 did block amphetamine-induced disruption of LI. These data indicate that, while LI may be unaffected by selective manipulation of activity at D1 receptors, the effects of amphetamine on LI are to some extent dependent on actions at D1 receptors.

  1. Latent KSHV Infected Endothelial Cells Are Glutamine Addicted and Require Glutaminolysis for Survival.

    Directory of Open Access Journals (Sweden)

    Erica L Sanchez

    2015-07-01

    Full Text Available Kaposi's Sarcoma-associated Herpesvirus (KSHV is the etiologic agent of Kaposi's Sarcoma (KS. KSHV establishes a predominantly latent infection in the main KS tumor cell type, the spindle cell, which is of endothelial cell origin. KSHV requires the induction of multiple metabolic pathways, including glycolysis and fatty acid synthesis, for the survival of latently infected endothelial cells. Here we demonstrate that latent KSHV infection leads to increased levels of intracellular glutamine and enhanced glutamine uptake. Depletion of glutamine from the culture media leads to a significant increase in apoptotic cell death in latently infected endothelial cells, but not in their mock-infected counterparts. In cancer cells, glutamine is often required for glutaminolysis to provide intermediates for the tri-carboxylic acid (TCA cycle and support for the production of biosynthetic and bioenergetic precursors. In the absence of glutamine, the TCA cycle intermediates alpha-ketoglutarate (αKG and pyruvate prevent the death of latently infected cells. Targeted drug inhibition of glutaminolysis also induces increased cell death in latently infected cells. KSHV infection of endothelial cells induces protein expression of the glutamine transporter, SLC1A5. Chemical inhibition of SLC1A5, or knockdown by siRNA, leads to similar cell death rates as glutamine deprivation and, similarly, can be rescued by αKG. KSHV also induces expression of the heterodimeric transcription factors c-Myc-Max and related heterodimer MondoA-Mlx. Knockdown of MondoA inhibits expression of both Mlx and SLC1A5 and induces a significant increase in cell death of only cells latently infected with KSHV, again, fully rescued by the supplementation of αKG. Therefore, during latent infection of endothelial cells, KSHV activates and requires the Myc/MondoA-network to upregulate the glutamine transporter, SLC1A5, leading to increased glutamine uptake for glutaminolysis. These findings

  2. Aportaciones a la transición del hiero I al hierro II en el centro de la cuenca del udero

    Directory of Open Access Journals (Sweden)

    Manuel GARCÍA ALONSO

    2009-10-01

    Full Text Available En la diversidad de publicaciones que se ponen al alcance del investigador, y que son referidas a la Edad del Hierro, entendida de una manera amplia, se viene observando, en el manejo terminológico más bien, una serie de cuestiones que quedan latentes entre las diferentes tomas de postura; pero que, salvo excepciones, no dan pie a una discusión o puesta en común de las mismas, y que entendemos son de capital importancia para la zona objeto de la presente comunicación.

  3. Using latent growth curve modeling in clinical treatment research: An example comparing guided self-change and cognitive behavioral therapy treatments for bulimia nervosa

    Directory of Open Access Journals (Sweden)

    Sam A. Hardy

    2009-01-01

    Full Text Available Este estudio experimental muestra la utilidad de los modelos multigrupo de curva de crecimiento latente por etapas en investigación clínica, concretamente en la evaluación y comparación de los efectos de tratamiento. Sesenta y dos pacientes femeninas (media de edad = 28,1; DT = 8 con bulimia nerviosa fueron asignadas al azar a: a un auto-tratamiento guiado compuesto por un manual de autocuidados más ocho sesiones quincenales de terapia cognitivo conductual (TCC, o b a 16 sesiones semanales de terapia cognitivo conductual (TCC. Ambos grupos mostraron mejorías significativas durante el tratamiento, aunque la TCC mostró mayor mejoría. Sin embargo, el tratamiento auto-guiado evidenció una mejoría más continuada después del tratamiento. Ambos programas mostraron variabilidad en la eficacia durante el tratamiento al menos en un resultado, mientras que el auto-tratamiento mostró una mayor variabilidad que la TCC durante el seguimiento en dos resultados. Los niveles de la línea de base estaban relacionados con los niveles en el seguimiento, particularmente en el tratamiento auto-guiado. Los modelos de curva latente ofrecen un análisis rico de estos datos y resuelven importantes cuestiones sobre las diferencias en la efectividad de los dos programas de tratamiento.

  4. Del Derecho laboral al Derecho del trabajo

    OpenAIRE

    Jaramillo Jassir, Ivan Daniel

    2011-01-01

    El Derecho Laboral hijo de la revolución industrial, calificado como el acontecimiento jurídico del siglo XX, reduce su ámbito de estudio al trabajo subordinado. Los cambios del sistema de producción superan la centralidad del contrato de trabajo subordinado a tiempo indeterminado, situación que demanda ampliación del ámbito de aplicación subjetivo y objetivo de la materia, dando paso al Derecho del Trabajo que se ocupa del trabajo en todas sus modalidades como fuente de ingreso para satisfac...

  5. Valoración del Hiper e Hipotiroidismo Post operatorio en la enfermedad de graves Basedow

    OpenAIRE

    De La Fuente, Edgardo León

    2010-01-01

    Tesis Doctor en Medicina y Cirugía -- Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. La enfermedad de Graves es una enfermedad autoinmune que tiene múltiples factores que la mantienen y que aún no pueden ser determinados. En este trabajo se investigo, sin haber precedentes, el factor de proliferación celular en relación a la función tiroidea post operatoria como principal objetivo de esta tesis, además de otros factores como las tiroiditis autoinmune que potencialmente podr...

  6. Signal transduction mechanisms within the entorhinal cortex that support latent inhibition of cued fear conditioning.

    Science.gov (United States)

    Lewis, Michael C; Gould, Thomas J

    2007-10-01

    Latent inhibition is a phenomenon by which pre-exposure to a conditioned-stimulus (CS), prior to subsequent pairings of that same CS with an unconditioned-stimulus (US), results in decreased conditioned responding to the CS. Previous work in our laboratory has suggested that the entorhinal cortex is critically involved in the establishment of latent inhibition of cued fear conditioning. Furthermore, utilizing systemic pharmacology, we have demonstrated a role for of NMDA receptors, protein kinase A (PKA), and mitogen activated protein kinase (MAPK, also known as ERK) in latent inhibition of cued fear conditioning, but until now, where these cell signaling cascades are critically activated during latent inhibition of cued fear was unknown. Here, we use direct drug infusion to demonstrate that cell signaling via NMDA receptors, the cAMP/PKA pathway, and the MAPK pathway within the entorhinal cortex are critically involved in latent inhibition of cued fear conditioning. In the present study, CS pre-exposed mice received 20 CS pre-exposures 24h prior to two pairings of the same CS with a 0.53 mA foot shock US, while control animals receive no pre-exposure to the CS. The NMDA antagonist APV (0.25 or 2.5 microg/side), the cAMP inhibitor Rp-cAMP (1.8 or 18.0 microg/side), or the MAPK inhibitor U0126 (0.1 or 1.0 microg/side) were directly infused into the entorhinal cortex prior to pre-exposure. All three drugs produced dose-dependent disruptions in latent inhibition of cued fear conditioning. Importantly, none of the drugs had any effect on cued fear conditioning when administered on training day, suggesting that the effects of each of the drugs were specific to CS pre-exposure. These results are discussed in relation to the potential mechanisms of plasticity that support latent inhibition of cued fear conditioning.

  7. Latent trajectory studies: the basics, how to interpret the results, and what to report

    Directory of Open Access Journals (Sweden)

    Rens van de Schoot

    2015-03-01

    Full Text Available Background: In statistics, tools have been developed to estimate individual change over time. Also, the existence of latent trajectories, where individuals are captured by trajectories that are unobserved (latent, can be evaluated (Muthén & Muthén, 2000. The method used to evaluate such trajectories is called Latent Growth Mixture Modeling (LGMM or Latent Class Growth Modeling (LCGA. The difference between the two models is whether variance within latent classes is allowed for (Jung & Wickrama, 2008. The default approach most often used when estimating such models begins with estimating a single cluster model, where only a single underlying group is presumed. Next, several additional models are estimated with an increasing number of clusters (latent groups or classes. For each of these models, the software is allowed to estimate all parameters without any restrictions. A final model is chosen based on model comparison tools, for example, using the BIC, the bootstrapped chi-square test, or the Lo-Mendell-Rubin test. Method: To ease the use of LGMM/LCGA step by step in this symposium (Van de Schoot, 2015 guidelines are presented which can be used for researchers applying the methods to longitudinal data, for example, the development of posttraumatic stress disorder (PTSD after trauma (Depaoli, van de Schoot, van Loey, & Sijbrandij, 2015; Galatzer-Levy, 2015. The guidelines include how to use the software Mplus (Muthén & Muthén, 1998–2012 to run the set of models needed to answer the research question: how many latent classes exist in the data? The next step described in the guidelines is how to add covariates/predictors to predict class membership using the three-step approach (Vermunt, 2010. Lastly, it described what essentials to report in the paper. Conclusions: When applying LGMM/LCGA models for the first time, the guidelines presented can be used to guide what models to run and what to report.

  8. A further assessment of the Hall-Rodriguez theory of latent inhibition.

    Science.gov (United States)

    Leung, Hiu Tin; Killcross, A S; Westbrook, R Frederick

    2013-04-01

    The Hall-Rodriguez (G. Hall & G. Rodriguez, 2010, Associative and nonassociative processes in latent inhibition: An elaboration of the Pearce-Hall model, in R. E. Lubow & I. Weiner, Eds., Latent inhibition: Data, theories, and applications to schizophrenia, pp. 114-136, Cambridge, England: Cambridge University Press) theory of latent inhibition predicts that it will be deepened when a preexposed target stimulus is given additional preexposures in compound with (a) a novel stimulus or (b) another preexposed stimulus, and (c) that deepening will be greater when the compound contains a novel rather than another preexposed stimulus. A series of experiments studied these predictions using a fear conditioning procedure with rats. In each experiment, rats were preexposed to 3 stimuli, 1 (A) taken from 1 modality (visual or auditory) and the remaining 2 (X and Y) taken from another modality (auditory or visual). Then A was compounded with X, and Y was compounded with a novel stimulus (B) taken from the same modality as A. A previous series of experiments (H. T. Leung, A. S. Killcross, & R. F. Westbrook, 2011, Additional exposures to a compound of two preexposed stimuli deepen latent inhibition, Journal of Experimental Psychology: Animal Behavior Processes, Vol. 37, pp. 394-406) compared A with Y, finding that A was more latently inhibited than Y, the opposite of what was predicted. The present experiments confirmed that A was more latently inhibited than Y, showed that this was due to A entering the compound more latently inhibited than Y, and finally, that a comparison of X and Y confirmed the 3 predictions made by the theory.

  9. Haloperidol treatment at pre-exposure phase reduces the disturbance of latent inhibition in rats with neonatal ventral hippocampus lesions.

    Science.gov (United States)

    Ouhaz, Zakaria; Ba-M'hamed, Saadia; Bennis, Mohamed

    2014-10-01

    Animals with neonatal ventral hippocampal lesions develop during or after adolescence abnormal behaviors related to schizophrenia such as anxiety and latent inhibition disruption. The aim of this study was to test whether haloperidol injection prior to pre-exposure session in the latent inhibition test would facilitate latent inhibition. Lesioned animals showed a significant decrease in the number and duration of social interactions, a decrease in the marbles buried, a significant increase in locomotor activity, and a disruption of latent inhibition. In the conditioned taste aversion test, injection of haloperidol produced the recovery of latent inhibition. These findings demonstrate that neonatal lidocaine lesion of the ventral hippocampus can induce behavioral changes related to schizophrenia, and injection of haloperidol, when restricted only to a three-day pre-exposure, is sufficient to facilitate latent inhibition.

  10. Osteoporosis grave con aplastamientos vertebrales en dermatomiositis juvenil: Efecto del tratamiento con alendronato oral Severe osteoporosis with vertebral crushes in juvenile dermatomyositis: Effect of oral alendronate therapy

    Directory of Open Access Journals (Sweden)

    Cristina Tau

    2007-02-01

    Full Text Available Los glucocorticoides son usados comúnmente para el tratamiento de enfermedades inflamatorias, autoinmunes, enfermedades malignas, y en la prevención de rechazo de órganos trasplantados. Un efecto secundario frecuente del tratamiento prolongado es la pérdida de masa ósea que se produce por varios mecanismos y es causa de osteoporosis y fracturas vertebrales. El tratamiento con disfosfonatos ha sido propuesto para esta situación. Presentamos un caso clínico de osteoporosis grave en una niña con dermatomiositis juvenil, que respondió favorablemente al tratamiento con disfosfonatos orales.Glucocorticoids are used for the treatment of inflammatory and autoimmune diseases, cancer, and in prevention of organ rejects. A frequent secondary effect of longterm treatment with corticoids is the loss of bone mass, caused by several mechanisms: decrease in the intestinal calcium absorption, increase of the renal calcium excretion at the distal renal tubule, suppressive effect on the osteoblast and also in apoptosis of osteoclasts, inhibition in local production of IGF I (Insulin-like growth factor and IGFBPs (binding IGF I proteins necessary for bone metabolism, and decrease on osteocalcin production. Longterm treatment with corticoids is associated with osteoporosis and vertebral fractures. To improve this condition, treatment with bisphosphonates has been proposed. We present here a clinical case of a girl with dermatomyositis and severe osteoporosis with vertebral crushes, who responded well to oral bisphophonate treatment.

  11. The latent fingerprint in mass transport of polycrystalline materials

    Science.gov (United States)

    Thirunavukarasu, Gopinath; Kundu, Sukumar; Chatterjee, Subrata

    2016-02-01

    Herein, a systematic investigation was carried out to reach a rational understanding and to provide information concerning the possible causes for a significant influence of pressure variation in the underlying processes of mass transport in polycrystalline materials. The authors focused their research in solid-state diffusion, a part of the subject "Mass Transport in Solids". Theories on diffusion are the subject by itself which exists as a latent fingerprint in every text of higher learning in interdisciplinary science. In this research, authors prepared sandwich samples of titanium alloy and stainless steel using nickel as an intermediate metal. The samples were processed at three different levels of bonding pressure (3, 4 and 5 MPa) while bonding temperature and bonding time was maintained at 750 °C and 1 h, respectively, throughout the experiments. It was observed that the net flux of atomic diffusion of nickel atoms into Ti-alloy at TiA/Ni interface increased by ~63 % with the rise in the bonding pressure from 3 to 4 MPa, but decreased by ~40 % with the rise in the bonding pressure from 4 to 5 MPa. At the same time, the net flux of atomic diffusion of nickel atoms into stainless steel at Ni/SS interface increased by ~19 % with the rise in the bonding pressure from 3 to 4 MPa, but increased by ~17 % with the rise in the bonding pressure from 4 to 5 MPa. Here authors showed that the pressure variations have different effects at the TiA/Ni interface and Ni/SS interface, and tried to explain the explicit mechanisms operating behind them. In general for sandwich samples processed irrespective of bonding pressure chosen, the net flux of Ni-atoms diffused into SS is greater than that of the net flux of Ni-atoms diffused in Ti-alloy matrix by four orders of magnitude. The calculated diffusivity of Ni-atoms into Ti-alloy reaches its highest value of ~5.083 × 10-19 m2/s for the sandwich sample processed using 4-MPa bonding-pressure, whereas the diffusivity of Ni

  12. Latent Fairness in Adults’ Relationship-Based Moral Judgments

    Science.gov (United States)

    Hao, Jian; Liu, Yanchun; Li, Jiafeng

    2015-01-01

    previous two experiments. Therefore, the present study shows that, in addition to apparent unfairness, latent fairness exists in adults’ relationship-based moral judgments. Moral judgments involving individuals with whom adults have different relationships have different cognitive and affective bases. PMID:26696935

  13. Latent Fairness in Adults' Relationship-Based Moral Judgments.

    Science.gov (United States)

    Hao, Jian; Liu, Yanchun; Li, Jiafeng

    2015-01-01

    two experiments. Therefore, the present study shows that, in addition to apparent unfairness, latent fairness exists in adults' relationship-based moral judgments. Moral judgments involving individuals with whom adults have different relationships have different cognitive and affective bases.

  14. Latent Fairness in Adults’ Relationship-Based Moral Judgments

    Directory of Open Access Journals (Sweden)

    Jian eHao

    2015-12-01

    replicated those of the previous two experiments. Therefore, the present study shows that, in addition to apparent unfairness, latent fairness exists in adults’ relationship-based moral judgments. Moral judgments involving individuals with whom adults have different relationships have different cognitive and affective bases.

  15. La responsabilidad social en empresas del Valle de Toluca (México). Un estudio exploratorio

    OpenAIRE

    Patricia Mercado Salgado; Patricia García Hernández

    2007-01-01

    En un mundo globalizado, el sector empresarial no puede seguir negando la necesidad de adoptar la responsabilidad social como estrategia para alcanzar beneficios externos e internos, pues sigue latente cierto comportamiento dominante de rechazo hacia ella. Por ello, el objetivo de esta investigación exploratoria, no experimental, es describir la responsabilidad social en empresas del Valle de Toluca (México) mediante cuatro componentes: ética empresarial, ...

  16. THE STUDY ON LATENT AND SENSIBLE HEAT FLUX OVER MIRE IN THE SANJIANG PLAIN

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Understanding how surface energy fluxes respond to environmental variables and how their components vary on daily and seasonal temporal scales are critical for understanding the ecological process of wetland ecosystem. In view of the fact that studies on surface energy flux over mire in China have been very limited, we have initiated a long-term latent and sensible heat flux (two main components of the surface energy balance) observation over mire in the Sanjiang Plain from June to October in 2004 with the eddy covariance technique. Results showed that the latent and sensible heat flux had large seasonal and diurnal variation during the period of measurement. Generally, latent heat flux between the mire wetland and the atmosphere reached the maximum value in June and then gradually decreased from June to October, whose daily mean fluxes were 9.83,8.00,7.33, 4.82 and 2.04 MJ/(m2·d), respectively. By comparison, sensible heat flux changed unnoticeably with season change from June to October, which were 1.47,0.88,1.75, 1.61,1.33 MJ/(m2·d) respectively. The diurnal variation of both latent and sensible heat flux varied noticeably within a day. After the sunrise, the latent and sensible heat flux increased and reached the maximum at noon (11:00-13:00). Then they decreased gradually and reached the minimum value during the nighttime. The patterns of temporal variation in latent and sensible heat flux were significantly controlled by environmental factors. The latent heat flux was linearly dependent on net radiation and increased with increasing vapour pressure deficit until the vapour pressure deficit surpassed 11 hPa. Wind speed effect on latent heat flux was more complicated and, in general, showed a positive correlation between them in daytime. The sensible heat flux was controlled mainly by air temperature difference between the land surface and the overlying air. However, when the temperature difference was larger than 0.3 ℃, it had no effect on the sensible

  17. [Dynamics of sensible and latent heat fluxes over a temperate desert steppe ecosystem in Inner Mongolia].

    Science.gov (United States)

    Zhang, Guo; Zhou, Guang-Sheng; Yang, Fu-Lin

    2010-03-01

    This paper studied the diurnal and seasonal characteristics of sensible and latent heat fluxes over a temperate desert steppe ecosystem in Inner Mongolia, based on the 2008 observation data from eddy covariance tower. The diurnal patterns of sensible and latent heat fluxes over the ecosystem were both single kurtosis, with the maximum value being 319.01 W x m(-2) (on May 30th, 2008) and 425.37 W x m(-2) (on Jun 2nd, 2008), respectively, and occurred at about 12:00-13:30 (local time), which was similar to the diurnal pattern of net radiation but lagged about one hour of the maximum net radiation. The maximum diurnal variations of monthly mean sensible and latent heat fluxes occurred in May and June, and their minimum diurnal variations occurred in January and November, respectively. There was a closer relationship between soil moisture content and precipitation. Surface soil moisture content was most sensitive to precipitation, while the moisture content in deeper soil layers had a lagged response to precipitation. The seasonal dynamics of sensible and latent heat fluxes was similar to that of net radiation, and affected by precipitation. Sensible heat flux was obviously affected by net radiation, but latent heat flux was more sensitive to precipitation and mainly controlled by soil moisture content.

  18. Determination of latent fingerprint degradation patterns-a real fieldwork study.

    Science.gov (United States)

    De Alcaraz-Fossoul, Josep; Mestres Patris, Cristina; Balaciart Muntaner, Antoni; Barrot Feixat, Carme; Gené Badia, Manel

    2013-07-01

    For over a century, law enforcement agencies, forensic laboratories, and penal courts worldwide have used fingerprint impressions as reliable and conclusive evidence to identify perpetrators of criminal activity. Although fingerprint identification has been repeatedly proven as one of the most robust and definite forensic techniques, a measure of the rate at which latent fingerprints degrade over time has not been established effectively. Ideally, criminal investigators should be able not only to place any given individual at a crime scene but also be able to date the moment any latent fingerprints were deposited at the location. The present report aims to determine particular visual patterns of degradation of latent fingerprints exposed to certain monitored laboratory conditions simulating those in the field. Factors considered include temperature, relative humidity, air currents, composition of fingerprint depositions (sebaceous and eccrine), various exposures to daylight (direct, penumbra, and darkness), and type of physical substrate (glass and plastic) over a period of 6 months. The study employs a titanium dioxide-based powder as developer. Our results indicate that, contrary to common belief, certain latent fingerprints exposed to direct sunlight indoors degrade similarly to those in the dark where environmental conditions are more constant. While all sebaceous latent fingerprints on glass are still useful for identification after 6 months, diverse results are obtained with impressions on plastic; these demonstrate a much higher and faster degree of decay, making identification difficult or impossible, especially for eccrine depositions.

  19. Latent Semantic Learning with Structured Sparse Representation for Human Action Recognition

    CERN Document Server

    Lu, Zhiwu

    2011-01-01

    This paper proposes a novel latent semantic learning method for extracting high-level features (i.e. latent semantics) from a large vocabulary of abundant mid-level features (i.e. visual keywords) with structured sparse representation, which can help to bridge the semantic gap in the challenging task of human action recognition. To discover the manifold structure of midlevel features, we develop a spectral embedding approach to latent semantic learning based on L1-graph, without the need to tune any parameter for graph construction as a key step of manifold learning. More importantly, we construct the L1-graph with structured sparse representation, which can be obtained by structured sparse coding with its structured sparsity ensured by novel L1-norm hypergraph regularization over mid-level features. In the new embedding space, we learn latent semantics automatically from abundant mid-level features through spectral clustering. The learnt latent semantics can be readily used for human action recognition with ...

  20. Vpx-containing Dendritic Cell Vaccine Vectors Induce CTLs and Reactivate Latent HIV-1 in vitro

    Science.gov (United States)

    Norton, Thomas D.; Miller, Elizabeth A.; Bhardwaj, Nina; Landau, Nathaniel R.

    2015-01-01

    Eradication of HIV-1 from an infected individual requires a means of inducing production of virus from latently infected cells and stimulating an immune response against the infected cells. We report the development of lentiviral vectors that transduce dendritic cells (DCs) to both induce production of virus from latently infected cells and stimulate antigen-specific CTLs. The vectors package Vpx, a lentiviral accessory protein that counteracts the SAMHD1-mediated block to DC transduction, allowing for long-term expression of vector-encoded proteins. The vectors encode influenza or HIV-1-derived epitopes fused via a self-cleaving peptide to CD40L that releases the peptide into the endoplasmic reticulum for entry into the antigen presentation pathway. Expression of CD40L caused transduced DCs to mature and produce Th1-skewing cytokines. The DCs presented antigen to CD8 T cells, enhancing antigen-specific CTLs. Coculture of the transduced DCs with latently infected cells induced high level virus production, an effect that was mediated by TNF-α. The ability of a DC vaccine to reactivate latent HIV-1 and stimulate an adaptive immune response provides a means to reduce the size of the latent reservoir in patients. This strategy can also be applied to develop DC vaccines for other diseases. PMID:25567537

  1. Latent Toxoplasma gondii infection leads to deficits in goal-directed behavior in healthy elderly.

    Science.gov (United States)

    Beste, Christian; Getzmann, Stephan; Gajewski, Patrick D; Golka, Klaus; Falkenstein, Michael

    2014-05-01

    Goal-directed behavior is well-known to show declines in elderly individuals, possibly because of alterations in dopaminergic neural transmission. The dopaminergic system is modulated by a number of other different factors. One of these factors, which has attracted a considerable amount of interest in neurobiology, but has only rarely been examined with respect to its possible modulatory role for cognitive functions in elderly individuals, is latent Toxoplasma gondii (T. gondii) infection. Latent T. gondii infection may be of relevance to goal-directed behavior as it alters dopaminergic neural transmission. We examine goal-directed behavior in T. gondii IgG positive and negative elderly subjects in auditory distraction paradigm. We apply event-related potentials to examine which cognitive subprocesses are affected by latent T. gondii infection on a neurophysiological level. We show that latent T. gondii infection compromises the management of auditory distraction in elderly by specifically delaying processes of attentional allocation and disengagement. The results show that latent T. gondii infection is neglected but an important neurobiological modulator of cognitive functions in elderly individuals.

  2. Examination of the change in latent statuses in bullying behaviors across time.

    Science.gov (United States)

    Ryoo, Ji Hoon; Wang, Cixin; Swearer, Susan M

    2015-03-01

    Involvement in bullying and victimization has been mostly studied using cross-sectional data from 1 time point. As such, much of our understanding of bullying and victimization has not captured the dynamic experiences of youth over time. To examine the change of latent statuses in bullying and victimization, we applied latent transition analysis examining self-reported bullying involvement from 1,180 students in 5th through 9th grades across 3 time points. We identified unobserved heterogeneous subgroups (i.e., latent statuses) and investigated how students transition between the unobserved subgroups over time. For victimization, 4 latent statuses were identified: frequent victim (11.23%), occasional traditional victim (28.86%), occasional cyber and traditional victim (10.34%), and infrequent victim (49.57%). For bullying behavior, 3 latent statuses were identified: frequent perpetrator (5.12%), occasional verbal/relational perpetrator (26.04%), and infrequent perpetrator (68.84%). The characteristics of the transitions were examined. The multiple-group effects of gender, grade, and first language learned on transitions across statuses were also investigated. The infrequent victim and infrequent perpetrator groups were the most stable, and the frequent victim and frequent perpetrator groups were the least stable. These findings suggest instability in perpetration and victimization over time, as well as significant changes, especially during school transition years. Findings suggest that school-based interventions need to address the heterogeneity in perpetrator and victim experiences in adolescence.

  3. Latent inhibition in the developing rat: an examination of context-specific effects.

    Science.gov (United States)

    Yap, Carol S L; Richardson, Rick

    2005-07-01

    Latent inhibition (LI) refers to the reduction in conditioned responding when the conditioned stimulus (CS) is preexposed prior to CS-unconditioned stimulus pairings. Experiment 1a demonstrated that preexposure to an odor CS prior to odor-shock pairings markedly reduced conditioned freezing in 25-day-old rats; however, this LI effect was observed only if odor preexposure and odor-shock pairings occurred in the same context (i.e., LI was context-specific at this age). The results of Experiment 1b showed that 18-day-olds also exhibited LI, but this effect was not context-specific at this age. In Experiment 2, rats were preexposed to the odor at 18 days of age and given odor-shock pairings at 25 days of age. These rats exhibited context-specific latent inhibition, suggesting that 18-day-old rats encoded the preexposure context. In Experiment 3, all parameters were identical to Experiment 2, with the exception that odor-shock pairings were given at approximately PN18 and testing occurred at approximately PN25. These rats exhibited latent inhibition at test, but this effect was not context-specific. The results of this study suggest that (a) PN18 rats can exhibit latent inhibition, and (b) the expression of context-specific latent inhibition depends on the age at which conditioning occurs.

  4. Application of mercaptosuccinic acid capped CdTe quantum dots for latent fingermark development.

    Science.gov (United States)

    Yu, Xuejiao; Liu, Jianjun; Zuo, Shengli; Yu, Yingchun; Cai, Kaiyang; Yang, Ruiqin

    2013-09-10

    The aqueous synthesis of mercaptosuccinic acid (MSA) capped CdTe quantum dots (QDs) solution for quickly and sensitively developing latent fingermarks is described. The rapid growth mechanism of CdTe/MSA QDs, which depends on the molecule structure of MSA, is briefly discussed and compared with that of thioglycolic acid (TGA) and mercaptopropionic acid (MPA) capped CdTe QDs. Development of latent fingermarks with the synthesized CdTe/MSA QDs was faster and the ridge details were clearer compared with CdTe/TGA QDs. In addition, latent fingermarks developed with CdTe/MSA QDs showed less background and better contrast than that of gentian violet or rhodamine 6G. Latent fingermarks could be well developed on black tape, scotch tape, tinfoil, aluminum alloy, stainless steel as well as on the adhesive side of yellow tape, even when the latter were aged up to seven days. As immersion time greatly reduced to 10 s by using CdTe/MSA QDs, a preliminary result of latent fingermark development by spraying was presented also.

  5. GABA transmission in the ventral pallidum is not involved in the control of latent inhibition in the rat.

    Science.gov (United States)

    Lawrence, N S; Sharp, T; Peters, S P; Gray, J A; Young, A M J

    2003-01-01

    Latent inhibition describes a process of learning to ignore stimuli of no consequence, and is disrupted in acute, positive-symptomatic schizophrenia. Understanding the neural basis of latent inhibition in animals may help to elucidate the neural dysfunction underlying positive schizophrenic symptoms in man. Evidence suggests a crucial role for dopamine transmission in the nucleus accumbens in the control of latent inhibition. The present studies investigated the role of the GABA-ergic efferent from the nucleus accumbens to the ventral pallidum in latent inhibition. The GABA(A) agonist muscimol (4.56 ng/microl), and antagonist picrotoxin (0.2 microg/microl), were infused into the ventral pallidum, and effects on latent inhibition were assessed using a conditioned suppression procedure. Neither drug produced specific effects on latent inhibition when given alone and, in the case of muscimol, failed to reverse the disruption of latent inhibition induced by systemic amphetamine. In addition to significant non-specific drug effects, a positive control experiment revealed that intra-pallidal picrotoxin significantly enhanced locomotion, suggesting that our manipulations of ventral pallidal GABA function were behaviourally effective. We conclude that modulating ventral pallidal GABA transmission does not affect latent inhibition. The implications of this finding for theories of the neural circuitry mediating latent inhibition and for understanding the functional role of ventral pallidal GABA transmission are discussed.

  6. del cambio

    Directory of Open Access Journals (Sweden)

    Alejandro Canales

    2006-01-01

    Full Text Available El artículo analiza las propuestas y los compromisos en materia de cobertura y de financiamiento en el periodo 2000-2006. En particular, revisa las modificaciones y los ajustes de los tres principales documentos en los que se expresaron las iniciativas: el de la Asociación Nacional de Universidades e Instituciones de Educación Superior, el del equipo de la transición y el programa sectorial. Los resultados muestran que las cifras de atención a la demanda educativa e inversión quedaron lejos de las metas autoimpuestas por el gobierno federal y que será necesario realizar mayores esfuerzos para atender tales desafíos.

  7. When Factorization Meets Heterogeneous Latent Topics:An Interpretable Cross-Site Recommendation Framework

    Institute of Scientific and Technical Information of China (English)

    辛欣; 林钦佑; 魏骁驰; 黄河燕

    2015-01-01

    Data sparsity is a well-known challenge in recommender systems. Previous studies alleviate this problem by incorporating the information within the corresponding social media site. In this paper, we solve this challenge by exploring cross-site information. Specifically, we examine: 1) how to effectively and efficiently utilize cross-site ratings and content features to improve recommendation performance and 2) how to make the recommendation interpretable by utilizing content features. We propose a joint model of matrix factorization and latent topic analysis. Heterogeneous content features are modeled by multiple kinds of latent topics. In addition, the combination of matrix factorization and latent topics makes the recommendation result interpretable. Therefore, the above two issues are simultaneously solved. Through a real-world dataset, where user behaviors in three social media sites are collected, we demonstrate that the proposed model is effective in improving recommendation performance and interpreting the rationale of ratings.

  8. Protein Kinase C: One Pathway towards the Eradication of Latent HIV-1 Reservoirs

    Directory of Open Access Journals (Sweden)

    Lisa N. McKernan

    2012-01-01

    Full Text Available An effective means to eradicate latent reservoirs in HIV-1-infected individuals remains elusive. Attempts to purge these reservoirs were undertaken over a decade ago without success. The subsequent lapse in further clinical attempts since may have been justified as our knowledge of the mechanisms which underpin the latent state still evolves. Although additional novel molecular antagonists of HIV-1 latency have subsequently been reported, these candidate agents have not been tested in human trials for reservoir ablation. This review provides an overview of the protein kinase C (PKC pathway which can be modulated by small molecular agents to induce the expression of latent HIV-1 from within infected reservoir cells. Some of these agents have been tested against select cancers with seemingly tolerable side effects. As such, modulation of the PKC pathway may yet be a viable mechanism toward HIV-1 reservoir eradication.

  9. A Modified Electrostatic Adsorption Apparatus for Latent Fingerprint Development on Unfired Cartridge Cases.

    Science.gov (United States)

    Xu, Jingyang; Zhang, Ziyuan; Zheng, Xiaochun; Bond, John W

    2016-12-13

    Visualization of latent fingerprints on metallic surfaces by the method of applying electrostatic charging and adsorption is considered as a promising chemical-free method, which has the merit of nondestruction, and is considered to be effective for some difficult situations such as aged fingerprint deposits or those exposed to environmental extremes. In fact, a portable electrostatic generator can be easily accessible in a local forensic technology laboratory, which is already widely used in the visualization of footwear impressions. In this study, a modified version of this electrostatic apparatus is proposed for latent fingerprint development and has shown great potential in visualizing fingerprints on metallic surfaces such as cartridge cases. Results indicate that this experimental arrangement can successfully develop aged latent fingerprints on metal surfaces, and we demonstrate its effectiveness compared with existing conventional fingerprint recovery methods.

  10. Joint analysis of time-to-event and multiple binary indicators of latent classes

    DEFF Research Database (Denmark)

    Larsen, Klaus

    2004-01-01

    Multiple categorical variables are commonly used in medical and epidemiological research to measure specific aspects of human health and functioning. To analyze such data, models have been developed considering these categorical variables as imperfect indicators of an individual's "true" status......, such as no additional effect of the observed indicators given latent class. The usefulness of the model framework and the proposed techniques are illustrated in an analysis of data from the Women's Health and Aging Study concerning the effect of severe mobility disability on time-to-death for elderly women....... of health or functioning. In this article, the latent class regression model is used to model the relationship between covariates, a latent class variable (the unobserved status of health or functioning), and the observed indicators (e.g., variables from a questionnaire). The Cox model is extended...

  11. Polarization-based and specular-reflection-based noncontact latent fingerprint imaging and lifting

    Science.gov (United States)

    Lin, Shih-Schön; Yemelyanov, Konstantin M.; Pugh, Edward N., Jr.; Engheta, Nader

    2006-09-01

    In forensic science the finger marks left unintentionally by people at a crime scene are referred to as latent fingerprints. Most existing techniques to detect and lift latent fingerprints require application of a certain material directly onto the exhibit. The chemical and physical processing applied to the fingerprint potentially degrades or prevents further forensic testing on the same evidence sample. Many existing methods also have deleterious side effects. We introduce a method to detect and extract latent fingerprint images without applying any powder or chemicals on the object. Our method is based on the optical phenomena of polarization and specular reflection together with the physiology of fingerprint formation. The recovered image quality is comparable to existing methods. In some cases, such as the sticky side of tape, our method shows unique advantages.

  12. Roles of Mesoscale Terrain and Latent Heat Release in Typhoon Precipitation: A Numerical Case Study

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The mesoscale orographic effects on typhoon Aere's precipitation are simulated using an Advanced Regional Eta-coordinate Model (AREM) version 3.0. In particular, the effects of the latent heat release are studied by two comparable experiments: with and without condensational heating. The results show that the typhoon rainfall is tripled by the southeastern China mesoscale terrain, and the condensational heating is responsible for at least half of the increase. One role of the latent heat release is to warm the atmosphere,leading to a depression of the surface pressure, which then causes a larger pressure difference in the zonal direction. This pressure gradient guides the water vapour to flow into the foothills, which in turn amplifies the water vapour flux divergence amplified, causing the typhoon rainfall to increase eventually. The other role of the latent heat release is to make the convection more organized, resulting in a relatively smaller rain area and stronger precipitation.

  13. Does attention-deficit/hyperactivity disorder have a dimensional latent structure? A taxometric analysis.

    Science.gov (United States)

    Marcus, David K; Barry, Tammy D

    2011-05-01

    An understanding of the latent structure of attention-deficit/hyperactivity disorder (ADHD) is essential for developing causal models of this disorder. Although some researchers have presumed that ADHD is dimensional and others have assumed that it is taxonic, there has been relatively little research directly examining the latent structure of ADHD. The authors conducted a set of taxometric analyses using data from the NICHD Study of Early Child Care and Youth Development (ns between 667 and 1,078). The results revealed a dimensional latent structure across a variety of different analyses and sets of indicators for inattention, hyperactivity/impulsivity, and ADHD. Furthermore, analyses of correlations with associated features indicated that dimensional models demonstrated stronger validity coefficients with these criterion measures than dichotomous models. These findings jibe with recent research on the genetic basis of ADHD and with contemporary models of ADHD.

  14. Fractional Stefan problems exhibiting lumped and distributed latent-heat memory effects

    Science.gov (United States)

    Voller, Vaughan R.; Falcini, Federico; Garra, Roberto

    2013-04-01

    We consider fractional Stefan melting problems which involve a memory of the latent-heat accumulation. We show that the manner in which the memory of the latent-heat accumulation is recorded depends on the assumed nature of the transition between the liquid and the solid phases. When a sharp interface between the liquid and the solid phases is assumed, the memory of the accumulation of the latent heat is “lumped” in the history of the speed of the interface. In contrast, when a diffuse interface is assumed, the memory of the accumulation is “distributed” throughout the liquid phase. By use of an example problem, we demonstrate that the equivalence of the sharp- and diffuse-interface models can only occur when there is no memory in the system.

  15. Heat requirement of greenhouses including latent heat flux; Waermebedarf von Gewaechshaeusern unter Beruecksichtigung des latenten Waermetransportes

    Energy Technology Data Exchange (ETDEWEB)

    Tantau, Hans-Juergen [Hannover Univ. (Germany). Fachgebiet Biosystem- und Gartenbautechnik

    2013-03-01

    Unlike buildings, the heat demand of greenhouses is affected also by the evaporation of the respective crop. Due to condensation of water vapour inside the covering material, latent heat is converted into sensible heat and transported outwards through the covering material. The portion of latent heat can increase to more than 50 % of the internal heat transfer and is therefore a significant heat flux, which must be considered in calculations of heat demand. The heat transfer coefficients (U-values), as they are given in literature, are only valid for dry conditions without condensation. In this work, a simplified methodological approach was chosen using heat transfer resistances to consider the latent heat flux and thus, to calculate U-values for greenhouse conditions including condensation. (orig.)

  16. Latent human error analysis and efficient improvement strategies by fuzzy TOPSIS in aviation maintenance tasks.

    Science.gov (United States)

    Chiu, Ming-Chuan; Hsieh, Min-Chih

    2016-05-01

    The purposes of this study were to develop a latent human error analysis process, to explore the factors of latent human error in aviation maintenance tasks, and to provide an efficient improvement strategy for addressing those errors. First, we used HFACS and RCA to define the error factors related to aviation maintenance tasks. Fuzzy TOPSIS with four criteria was applied to evaluate the error factors. Results show that 1) adverse physiological states, 2) physical/mental limitations, and 3) coordination, communication, and planning are the factors related to airline maintenance tasks that could be addressed easily and efficiently. This research establishes a new analytic process for investigating latent human error and provides a strategy for analyzing human error using fuzzy TOPSIS. Our analysis process complements shortages in existing methodologies by incorporating improvement efficiency, and it enhances the depth and broadness of human error analysis methodology.

  17. Super fast detection of latent fingerprints with water soluble CdTe quantum dots.

    Science.gov (United States)

    Cai, Kaiyang; Yang, Ruiqin; Wang, Yanji; Yu, Xuejiao; Liu, Jianjun

    2013-03-10

    A new method based on the use of highly fluorescent water-soluble cadmium telluride (CdTe) quantum dots (QDs) capped with mercaptosuccinic acid (MSA) was explored to develop latent fingerprints. After optimized the effectiveness of QDs method contains pH value and developing time, super fast detection was achieved. Excellent fingerprint images were obtained in 1-3s after immersed the latent fingerprints into quantum dots solution on various non-porous surfaces, i.e. adhesive tape, transparent tape, aluminum foil and stainless steel. High sensitivity of the new latent fingerprints develop method was obtained by developing the fingerprints pressed on aluminum foil successively with the same finger. Compared with methyl violet and rhodamine 6G, the MSA-CdTe QDs showed the higher develop speed and fingerprint image quality. Clear image can be maintained for months by extending exposure time of CCD camera, storing fingerprints in a low temperature condition and secondary development.

  18. Thermal cycle testing of calcium chloride hexahydrate as a possible PCM for latent heat storage

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, V.V.; Buddhi, D. [Thermal Energy Storage Laboratory, School of Energy and Environmental Studies, Devi Ahilya University, Indore 452017 (India)

    2008-08-15

    In order to study the changes in latent heat of fusion and melting temperature of calcium chloride hexahydrate (CaCl{sub 2}.6H{sub 2}O) inorganic salt as a latent heat storage material, a thousand accelerated thermal cycle tests have been conducted. The effect of thermal cycling and the reliability in terms of the changing of the melting temperature using a differential scanning calorimeter (DSC) is determined. It has been noticed that the CaCl{sub 2}.6H{sub 2}O melts between a stable range of temperature and has shown small variations in the latent heat of fusion during the thermal cycling process. Thus, it can be a promising phase change material (PCM) for heating and cooling applications for various building/storage systems. (author)

  19. The Latent Factor Structure of Acute Stress Disorder following Bank Robbery

    DEFF Research Database (Denmark)

    Hansen, M.; Lasgaard, M.; Elklit, A.

    2013-01-01

    to identify victims at risk of developing posttraumatic stress disorder (PTSD). Since its introduction, research into ASD has focused on the prediction of PTSD, whereas only a few studies have investigated the latent structure of ASD. Results of the latter have been mixed. In light of the current proposal...... for the ASD diagnosis in the pending DSM-5, there is a profound need for empirical studies that investigate the latent structure of ASD prior to the DSM-5 being finalized. DESIGN: Based on previous factor analytic research, the DSM-IV, and the proposed DSM-5 formulation of ASD, four different models...... of the latent structure of ASD were specified and estimated. METHOD: The analyses were based on a national study of bank robbery victims (N = 450) using the acute stress disorder scale. RESULTS: The results of the confirmatory factor analyses showed that the DSM-IV model provided the best fit to the data. Thus...

  20. Latent acyclovir-resistant herpes simplex virus type 1 in trigeminal ganglia of immunocompetent individuals.

    Science.gov (United States)

    van Velzen, Monique; van Loenen, Freek B; Meesters, Roland J W; de Graaf, Miranda; Remeijer, Lies; Luider, Theo M; Osterhaus, Albert D M E; Verjans, Georges M G M

    2012-05-15

    Specific mutations within the hypervariable herpes simplex virus (HSV) gene thymidine kinase (TK) gene lead to acyclovir (ACV) resistance. To uncover the existence of latent ACV-resistant (ACV(R)) HSV-1, we determined the genetic and functional variability of the HSV-1 TK gene pool in paired trigeminal ganglia (TG) of 5 immunocompetent individuals. The latent virus pool consisted of a donor-specific HSV-1 quasispecies, including one major ACV-sensitive (ACV(S)) and multiple phylogenetic-related minor ACV(S) and ACV(R) TK variants. Contrary to minor variants, major TK variants were shared between paired TG. The data demonstrate the coexistence of phylogenetic-related ACV(S) and ACV(R) latent HSV-1 in human TG.