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Sample records for autoinmune latente del

  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. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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

  9. Importancia del fenotipo de la a1-antitripsina en las manifestaciones clínicas y en el pronóstico de las enfermedades sistémicas autoinmunes

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    Jiménez Moreno, Francesc Xavier

    2001-01-01

    El déficit de a1 -antitripsina (a-1-AT) es una enfermedad hereditaria relativamente frecuente que se caracteriza clásicamente por una reducción de los valores séricos de a-1-AT, y por la presencia de enfisema pulmonar y hepatopatía.Las mutaciones del gen de la a-1-AT provocan una incapacidad de sintetizar y secretar cantidades normales de a-1-AT. Cuando los valores séricos son menores de 50 mg/dl la a-1-AT sintetizada es insuficiente para proteger el alvéolo de la elastasa, provocando una pr...

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

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    F. Javier Jiménez-Balderas; Adolfo Camargo-Coronel; Juan O. Talavera; 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...

  11. 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

  12. 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.

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

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    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...

  14. 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.

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

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    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.

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

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    Pinal Fernández, Iago

    2015-01-01

    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 dia...

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

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    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. Aprendizaje espacial en laberintos en una tarea de discriminación. Los fenómenos de la inhibición latente y del aprendizaje perceptivo.

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    Sansa i Aguilar, Joan

    1995-01-01

    [spa] La exposición previa a un estimulo que se usará como estímulo condicionado (EC) en un paradigma de condicionamiento clásico típicamente retrasa el condicionamiento posterior. Este es el fenómeno de la inhibición latente (IL) (Lubow, 1989). Sin embargo, en ocasiones esta exposición tiene el efecto opuesto. Así, en el aprendizaje latente, la exposición a un laberinto de múltiples unidades facilitará la elección del camino correcto cuando posteriormente se introduce e! reforzador (Tolman y...

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

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    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

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

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    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.

  1. 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

  2. Revelado de manchas latentes: efectividad del luminol y evaluación de su efecto sobre el estudio del DNA Development of latent stains: effectiveness of luminol and evaluation of its effect on DNA analysis

    OpenAIRE

    A. Castelló Ponce; M. Álvarez Seguí; Miquel Feucht, M.; F.A. Verdú Pascual

    2002-01-01

    Con frecuencia, las ropas manchadas de sangre durante un acto violento son lavadas para tratar de eliminar los vestigios. El análisis del DNA mediante PCR ha dotado a la criminalística de la posibilidad de estudiar indicios mínimos que, con otros métodos, sería imposible analizar. Este tipo de muestra plantea una mayor dificultad en la detección de la mancha. En el presente trabajo se analiza la sensibilidad del luminol para encontrar manchas de sangre invisibles. Sobre estas manchas se inten...

  3. 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.

  4. Latent Class Models in the Assessment of Education: The Case of Students’ Academic Attainment in Elementary Education in Zacatecas Modelos de Clase Latente en la Evaluación de la Educación. El Caso del Aprovechamiento Escolar en la Educación Primaria de Zacatecas.

    Directory of Open Access Journals (Sweden)

    Francisco Muro González

    2008-01-01

    Full Text Available Based on an advanced statistical method (Latent Class Analysis, the author jointly examines two crucial factors in the assessment of students? performance in elementary school: School attainment and teacher education ( based on teachers? results in tests taken to earn their teaching credentials. Data from files in the 2001 Archives for the State of Zacatecas, Mexico are used to make this analysis. The author shows that when working with latent class models, one can make a more significant in depth analysis because by virtue of using this method, it is viable to construct suitable clusters and to segment the data files more efficiently in order to find differentiated effects of parameters in the population. A partir de una metodología de estadística avanzada, la de análisis de clase latente, el autor analiza conjuntamente dos archivos cruciales en la evaluación del desempeño de los estudiantes de primaria: los de factor aprovechamiento escolar y factor preparación profesional (o resultados de los exámenes de carrera magisterial. El autor utiliza para ello los archivos correspondientes al año 2001 del estado de Zacatecas. En el texto se muestra que al trabajar con modelos de clase latente se puede ganar significativamente en profundidad en el análisis, pues mediante este método es viable construir clusters adecuados y segmentar eficientemente el archivo de datos para encontrar efectos diferenciados de los parámetros en la población.


    1En el año del 2003 tuve la oportunidad de realizar un estudio para la Secretaría de Educación y Cultura del gobierno del estado de Zacatecas, México, motivo por el cual se me dio acceso a los datos referidos.

  5. Revelado de manchas latentes: efectividad del luminol y evaluación de su efecto sobre el estudio del DNA Development of latent stains: effectiveness of luminol and evaluation of its effect on DNA analysis

    Directory of Open Access Journals (Sweden)

    A. Castelló Ponce

    2002-04-01

    Full Text Available Con frecuencia, las ropas manchadas de sangre durante un acto violento son lavadas para tratar de eliminar los vestigios. El análisis del DNA mediante PCR ha dotado a la criminalística de la posibilidad de estudiar indicios mínimos que, con otros métodos, sería imposible analizar. Este tipo de muestra plantea una mayor dificultad en la detección de la mancha. En el presente trabajo se analiza la sensibilidad del luminol para encontrar manchas de sangre invisibles. Sobre estas manchas se intenta extraer y amplificar DNA. Los resultados indican que el luminol es muy eficaz para detectar indicios invisibles. Además, en las condiciones experimentales con las que se ha elaborado este trabajo, no se produce interferencia del reactivo en la posterior extracción y amplificación del DNA.Frequently, clothes stained with blood during a violent act are washed to try to eliminate the traces. The analysis of DNA by means of PCR has provided criminalistics with the possibility of studying minimum traces which would be impossible to analyse by other methods. Detection of the stain is extremely difficult in this type of sample. The present paper examines the sensitivity of luminol for finding invisible blood stains, and an attempt is made to extract and amplify DNA from them. The results show that luminol is very efficient for the detection of invisible stains. In the experimental conditions used in this work, the reagent does not interfere in the posterior extraction and amplification of DNA.

  6. 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.

  7. 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

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

    OpenAIRE

    M.S. Mallea Gil; M.C. Ballarino; M.M. Aparicio; K. Bertini; M.C. Ridruejo; Gimenez, S.; Galarza, P.; A. Perusco; S. Roveto; D. Rimoldi

    2010-01-01

    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...

  9. 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

  10. 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

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

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    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.

  12. Latent Toxoplasmosis and Human

    OpenAIRE

    Abdoli, A; A Dalimi

    2012-01-01

    Toxoplasmosis is one of the most common parasitic diseases worldwide. Although estimated that one third of the world's population are infected with Toxoplasma gondii, but the most common form of the disease is latent (asymptomatic). On the other hand, recent findings indicated that latent toxoplasmosis is not only unsafe for human, but also may play various roles in the etiology of different mental disorders. This paper reviews new findings about importance of latent toxoplasmosis (except in ...

  13. Contribución de la electrofisiología al diagnóstico de un grupo de neuropatías autoinmunes

    OpenAIRE

    Hernández Hernández, Bárbara Haymeé

    2007-01-01

    El síndrome de Guillain Barré (SGB) y la polineuropatía desmielinizante inflamatoria crónica (CIDP) son polineurorradiculopatías desmielinizantes inflamatorias adquiridas de etiología autoinmune, de curso agudo la primera y crónico la segunda; ambas predominantemente motoras, que en su evolución pueden dejar secuelas invalidantes en los individuos afectados. De ahí la importancia de un diagnóstico precoz y de un tratamiento adecuado desde etapas iniciales. Los estudios neurofisiológicos son u...

  14. 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.

  15. 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.

  16. Latent Structured Ranking

    OpenAIRE

    Weston, Jason; Blitzer, John

    2012-01-01

    Many latent (factorized) models have been proposed for recommendation tasks like collaborative filtering and for ranking tasks like document or image retrieval and annotation. Common to all those methods is that during inference the items are scored independently by their similarity to the query in the latent embedding space. The structure of the ranked list (i.e. considering the set of items returned as a whole) is not taken into account. This can be a problem because the set of top predicti...

  17. Latent classification models

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre

    2005-01-01

    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....

  18. Visualizing latent domain knowledge

    OpenAIRE

    Chen, C.; Kuljis, J; Paul, RJ

    2001-01-01

    Knowledge discovery and data mining commonly rely on finding salient patterns of association from a vast amount of data. Traditional citation analysis of scientific literature draws insights from strong citation patterns. Latent domain knowledge, in contrast to the mainstream domain knowledge, often consists of highly relevant but relatively infrequently cited scientific works. Visualizing latent domain knowledge presents a significant challenge to knowledge discovery and quantitative studies...

  19. 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

  20. Latent Toxoplasmosis and Human

    Directory of Open Access Journals (Sweden)

    A Abdoli

    2012-02-01

    Full Text Available Toxoplasmosis is one of the most common parasitic diseases worldwide. Although estimated that one third of the worlds population are infected with Toxoplasma gondii, but the most common form of the disease is latent (asymptomatic. On the other hand, recent findings indicated that latent toxoplasmosis is not only unsafe for human, but also may play various roles in the etiology of different mental disorders. This paper reviews new findings about importance of latent toxoplasmosis (except in immunocompromised patients in alterations of behavioral parameters and also its role in the etiology of schizophrenia and depressive disorders, obsessive-compulsive disorder, Alzheimers diseases and Parkinson;s disease, epilepsy, headache and or migraine, mental retardation and intelligence quotients, suicide attempt, risk of traffic accidents, sex ratio and some possible mechanisms of T. gondii that could contribute in the etiology of these alterations.

  1. Latent toxoplasmosis and human.

    Science.gov (United States)

    Dalimi, A; Abdoli, A

    2012-01-01

    Toxoplasmosis is one of the most common parasitic diseases worldwide. Although estimated that one third of the world's population are infected with Toxoplasma gondii, but the most common form of the disease is latent (asymptomatic). On the other hand, recent findings indicated that latent toxoplasmosis is not only unsafe for human, but also may play various roles in the etiology of different mental disorders. This paper reviews new findings about importance of latent toxoplasmosis (except in immunocompromised patients) in alterations of behavioral parameters and also its role in the etiology of schizophrenia and depressive disorders, obsessive-compulsive disorder, Alzheimer's diseases and Parkinson's disease, epilepsy, headache and or migraine, mental retardation and intelligence quotients, suicide attempt, risk of traffic accidents, sex ratio and some possible mechanisms of T. gondii that could contribute in the etiology of these alterations.

  2. 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.

  3. Latent Class Models in the Assessment of Education: The Case of Students’ Academic Attainment in Elementary Education in Zacatecas Modelos de Clase Latente en la Evaluación de la Educación. El Caso del Aprovechamiento Escolar en la Educación Primaria de Zacatecas.

    OpenAIRE

    Francisco Muro González

    2008-01-01

    Based on an advanced statistical method (Latent Class Analysis), the author jointly examines two crucial factors in the assessment of students? performance in elementary school: School attainment and teacher education ( based on teachers? results in tests taken to earn their teaching credentials). Data from files in the 2001 Archives for the State of Zacatecas, Mexico are used to make this analysis. The author shows that when working with latent class models, one can make a more significant i...

  4. 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...

  5. 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.

  6. 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.

  7. 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...

  8. Latent heat of nuclear matter

    CERN Document Server

    Carbone, Arianna; Rios, Arnau; Vidaña, Isaac

    2010-01-01

    We study the latent heat of the liquid-gas phase transition in symmetric nuclear matter using self-consistent mean-field calculations with a few Skyrme forces. The temperature dependence of the latent heat is rather independent of the mean-field parametrization and can be characterized by a few parameters. At low temperatures, the latent heat tends to the saturation energy. Near the critical point, the latent heat goes to zero with a well-determined mean-field critical exponent. A maximum value of the latent heat in the range l ~ 25-30 MeV is found at intermediate temperatures, which might have experimental relevance. All these features can be explained from very basic principles.

  9. 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...

  10. 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...

  11. 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...

  12. 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.

  13. Manejo clínico odontológico integral del paciente con síndrome de Sjögren: una propuesta

    OpenAIRE

    G. Sturla Rojas; F Romo Ormazábal; M.A. Torres-Quintana

    2014-01-01

    El síndrome de Sjögren (SS) es una enfermedad autoinmune, crónica e inflamatoria caracterizada por infiltración de células plasmáticas y linfocitos en las glándulas exocrinas, particularmente en las salivales y oculares. La patogénesis del SS está relacionada con factores inmunológicos, neurológicos, genéticos, virales y hormonales. La deficiente calidad y cantidad de saliva trae consecuencias devastadoras para la salud dental y bucal, alteraciones del esmalte, caries en las superficies denta...

  14. 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....

  15. 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...

  16. 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...

  17. 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.

  18. 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...

  19. 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...

  20. 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...

  1. Latent IBP Compound Dirichlet Allocation.

    Science.gov (United States)

    Archambeau, Cedric; Lakshminarayanan, Balaji; Bouchard, Guillaume

    2015-02-01

    We introduce the four-parameter IBP compound Dirichlet process (ICDP), a stochastic process that generates sparse non-negative vectors with potentially an unbounded number of entries. If we repeatedly sample from the ICDP we can generate sparse matrices with an infinite number of columns and power-law characteristics. We apply the four-parameter ICDP to sparse nonparametric topic modelling to account for the very large number of topics present in large text corpora and the power-law distribution of the vocabulary of natural languages. The model, which we call latent IBP compound Dirichlet allocation (LIDA), allows for power-law distributions, both, in the number of topics summarising the documents and in the number of words defining each topic. It can be interpreted as a sparse variant of the hierarchical Pitman-Yor process when applied to topic modelling. We derive an efficient and simple collapsed Gibbs sampler closely related to the collapsed Gibbs sampler of latent Dirichlet allocation (LDA), making the model applicable in a wide range of domains. Our nonparametric Bayesian topic model compares favourably to the widely used hierarchical Dirichlet process and its heavy tailed version, the hierarchical Pitman-Yor process, on benchmark corpora. Experiments demonstrate that accounting for the power-distribution of real data is beneficial and that sparsity provides more interpretable results. PMID:26353244

  2. Information-Theoretic Latent Distribution Modeling: Distinguishing Discrete and Continuous Latent Variable Models

    Science.gov (United States)

    Markon, Kristian E.; Krueger, Robert F.

    2006-01-01

    Distinguishing between discrete and continuous latent variable distributions has become increasingly important in numerous domains of behavioral science. Here, the authors explore an information-theoretic approach to latent distribution modeling, in which the ability of latent distribution models to represent statistical information in observed…

  3. Semi-Nonparametric Methods for Detecting Latent Non-Normality: A Fusion of Latent Trait and Ordered Latent Class Modeling

    Science.gov (United States)

    Schmitt, J. Eric; Mehta, Paras D.; Aggen, Steven H.; Kubarych, Thomas S.; Neale, Michael C.

    2006-01-01

    Ordered latent class analysis (OLCA) can be used to approximate unidimensional latent distributions. The main objective of this study is to evaluate the method of OLCA in detecting non-normality of an unobserved continuous variable (i.e., a common factor) used to explain the covariation between dichotomous item-level responses. Using simulation,…

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

    OpenAIRE

    JORGE E. CÓRDOBA MAQUILÓN; G. PATRICIA JARAMILLO ÁLVAREZ

    2012-01-01

    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 altern...

  5. Analysis of latent structures in linear systems

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2004-01-01

    the latent structure of a linear model. Here the ‘atomic’ parts of the algorithms that generate the latent structure for linear models are analyzed. It is shown how the PLS algorithm fits within this way of presenting the numerical procedures. The second part is concerning graphic illustrations...

  6. Heteroscedastic latent trait models for dichotomous data

    NARCIS (Netherlands)

    D. Molenaar

    2014-01-01

    Effort has been devoted to account for heteroscedasticity with respect to observed or latent moderator variables in item or test scores. For instance, in the multi-group generalized linear latent trait model, it could be tested whether the observed (polychoric) covariance matrix differs across the l

  7. Learning latent structure for activity recognition

    NARCIS (Netherlands)

    N. Hu; G. Englebienne; Z. Lou; B. Kröse

    2014-01-01

    We present a novel latent discriminative model for human activity recognition. Unlike the approaches that require conditional independence assumptions, our model is very flexible in encoding the full connectivity among observations, latent states, and activity states. The model is able to capture ri

  8. Latent variables and route choice behavior

    DEFF Research Database (Denmark)

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

    2012-01-01

    by proposing and estimating a hybrid model that integrates latent variable and route choice models. Data contain information about latent variable indicators and chosen routes of travelers driving regularly from home to work in an urban network. Choice sets include alternative routes generated with a branch...... and bound algorithm. A hybrid model consists of measurement equations, which relate latent variables to measurement indicators and utilities to choice indicators, and structural equations, which link travelers’ observable characteristics to latent variables and explanatory variables to utilities. Estimation...... 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....

  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. Learning Latent Structure in Complex Networks

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai

    Latent structure in complex networks, e.g., in the form of community structure, can help understand network dynamics, identify heterogeneities in network properties, and predict ‘missing’ links. While most community detection algorithms are based on optimizing heuristic clustering objectives...... 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...

  11. 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.

  12. Latent and delayed action polymerization systems.

    Science.gov (United States)

    Naumann, Stefan; Buchmeiser, Michael R

    2014-04-01

    Various approaches to latent polymerization processes are described. In order to highlight recent advances in this field, the discussion is subdivided into chapters dedicated to diverse classes of polymers, namely polyurethanes, polyamides, polyesters, polyacrylates, epoxy resins, and metathesis-derived polymers. The described latent initiating systems encompass metal-containing as well as purely organic compounds that are activated by external triggers such as light, heat, or mechanical force. Special emphasis is put on the different chemical venues that can be taken to achieve true latency, which include masked N-heterocyclic carbenes, latent metathesis catalysts, and photolatent radical initiators, among others. Scientific challenges and the advantageous application of latent polymerization processes are discussed. PMID:24519912

  13. Heteroscedastic Latent Trait Models for Dichotomous Data.

    Science.gov (United States)

    Molenaar, Dylan

    2015-09-01

    Effort has been devoted to account for heteroscedasticity with respect to observed or latent moderator variables in item or test scores. For instance, in the multi-group generalized linear latent trait model, it could be tested whether the observed (polychoric) covariance matrix differs across the levels of an observed moderator variable. In the case that heteroscedasticity arises across the latent trait itself, existing models commonly distinguish between heteroscedastic residuals and a skewed trait distribution. These models have valuable applications in intelligence, personality and psychopathology research. However, existing approaches are only limited to continuous and polytomous data, while dichotomous data are common in intelligence and psychopathology research. Therefore, in present paper, a heteroscedastic latent trait model is presented for dichotomous data. The model is studied in a simulation study, and applied to data pertaining alcohol use and cognitive ability. PMID:25080866

  14. Endogenous Opioid-Masked Latent Pain Sensitization

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...

  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. 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.

  17. Thermally Stable, Latent Olefin Metathesis Catalysts

    OpenAIRE

    Thomas, Renee M.; Fedorov, Alexey; Keitz, Benjamin K.; Grubbs, Robert H.

    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 i...

  18. 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.

  19. Autoimmune polyglandular syndrome type II in Hospital Universitario del Caribe, Cartagena Colombia.

    Directory of Open Access Journals (Sweden)

    Fortich-Revollo Álvaro José

    2011-06-01

    Full Text Available Autoimmune polyglandular syndrome is a polyendocrinopathy characterized by failureof some endocrine glands as well as nonendocrine organs, caused by actions of theimmune system on endocrine tissues. It has been described two groups and at leasttwo or three variants of them. Autoimmune polyglandular autoimmune syndrome typeII is the most common autoimmune endocrinopathy that is characterized mainly bypresence of Addison’s disease in combination with autoimmune thyroid disease or typeI diabetes mellitus. We review the topic and immunogenetics and etiopathological basesand present a case series. The incidence is 1.2/100.000. The most common finding wasAddison’s disease plus autoimmune thyroiditis (80% and the second most frequentassociation was thyroiditis with pernicious anemia (60%. It is important to note thehigh frequency of vitamin B12 deficiency in patients with severe neuronal impairment. Itmay take up to twenty years between diagnosis of an endocrine disease and emergenceof another disease. It is the duty to perform diagnostic tests to evaluate hormonalfunction correlated with an endocrinopathy until senescence.RESUMEN:El Síndrome Poliglandular Autoinmune es una poliendocrinopatía caracterizada porfalla de algunas glándulas endocrinas así como también en órganos no endocrinos,originada por acciones del sistema inmune sobre tejidos endocrinos. Se han descritodos grandes grupos y al menos dos o tres variantes de ellos. El Síndrome PoliglandularAutoinmune tipo II es la más común de las inmunoendocrinopatias. Se caracteriza porla presencia de la enfermedad de Addison en combinación con enfermedad tiroideaautoinmune y/o diabetes mellitus tipo I. Se realizo una revisión del tema con basesinmunogenéticas y etiopatológicas. Se presenta una serie de casos. La incidenciaacumulada es de 1.2/100.000 habitante. El hallazgo más frecuente fue enfermedadde Addison más Tiroiditis autoinmune, (80 % y la segunda asociación m

  20. 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.

  1. 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.

  2. Text Categorization with Latent Dirichlet Allocation

    Directory of Open Access Journals (Sweden)

    ZLACKÝ Daniel

    2014-05-01

    Full Text Available This paper focuses on the text categorization of Slovak text corpora using latent Dirichlet allocation. Our goal is to build text subcorpora that contain similar text documents. We want to use these better organized text subcorpora to build more robust language models that can be used in the area of speech recognition systems. Our previous research in the area of text categorization showed that we can achieve better results with categorized text corpora. In this paper we used latent Dirichlet allocation for text categorization. We divided initial text corpus into 2, 5, 10, 20 or 100 subcorpora with various iterations and save steps. Language models were built on these subcorpora and adapted with linear interpolation to judicial domain. The experiment results showed that text categorization using latent Dirichlet allocation can improve the system for automatic speech recognition by creating the language models from organized text corpora.

  3. Stability of latent class segments over time

    DEFF Research Database (Denmark)

    Mueller, Simone

    2011-01-01

    a stated preference choice experiment for environmental food claims remain stable over time. Following a cross-sectional design, two different consumer samples from an online panel provider participated in two identical choice experiments within eighteen months. On the aggregated level, a heteroskedastic...... in significant differences in the size of two out of seven classes. These differences can largely be accounted for by the changes on the aggregated level. The relative size of latent classes is correlated at 0.52, suggesting a fair robustness. An ex-post characterisation of latent classes by behavioural...

  4. Latent Classification Models for Binary Data

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre

    2009-01-01

    between the attributes. In addition to providing good classification accuracy, the LCM model has several appealing properties, including a relatively small parameter space making it less susceptible to over-fitting. In this paper we take a first-step towards generalizing LCMs to hybrid domains...... the class of that instance. To relax this independence assumption, we have in previous work proposed a family of models, called latent classification models (LCMs). LCMs are defined for continuous domains and generalize the naive Bayes model by using latent variables to model class-conditional dependencies...

  5. Correlated Non-Parametric Latent Feature Models

    CERN Document Server

    Doshi-Velez, Finale

    2012-01-01

    We are often interested in explaining data through a set of hidden factors or features. When the number of hidden features is unknown, the Indian Buffet Process (IBP) is a nonparametric latent feature model that does not bound the number of active features in dataset. However, the IBP assumes that all latent features are uncorrelated, making it inadequate for many realworld problems. We introduce a framework for correlated nonparametric feature models, generalising the IBP. We use this framework to generate several specific models and demonstrate applications on realworld datasets.

  6. 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.

  7. Residual Structures in Latent Growth Curve Modeling

    Science.gov (United States)

    Grimm, Kevin J.; Widaman, Keith F.

    2010-01-01

    Several alternatives are available for specifying the residual structure in latent growth curve modeling. Two specifications involve uncorrelated residuals and represent the most commonly used residual structures. The first, building on repeated measures analysis of variance and common specifications in multilevel models, forces residual variances…

  8. Immune Function and Reactivation of Latent Viruses

    Science.gov (United States)

    Butel, Janet S.

    1999-01-01

    A major concern associated with long-duration space flight is the possibility of infectious diseases posing an unacceptable medical risk to crew members. One major hypothesis addressed in this project is that space flight will cause alterations in the immune system that will allow latent viruses that are endogenous in the human population to reactivate and shed to higher levels than normal, which may affect the health of crew members. The second major hypothesis being examined is that the effects of space flight will alter the mucosal immune system, the first line of defense against many microbial infections, including herpesviruses, polyomaviruses, and gastroenteritis viruses, rendering crew members more susceptible to virus infections across the mucosa. We are focusing the virus studies on the human herpesviruses and polyomaviruses, important pathogens known to establish latent infections in most of the human population. Both primary infection and reactivation from latent infection with these groups of viruses (especially certain herpesviruses) can cause a variety of illnesses that result in morbidity and, occasionally, mortality. Both herpesviruses and polyomaviruses have been associated with human cancer, as well. Effective vaccines exist for only one of the eight known human herpesviruses and available antivirals are of limited use. Whereas normal individuals display minimal consequences from latent viral infections, events which alter immune function (such as immunosuppressive therapy following solid organ transplantation) are known to increase the risk of complications as a result of viral reactivations.

  9. 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

  10. 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…

  11. 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…

  12. Thermally Stable, Latent Olefin Metathesis Catalysts.

    Science.gov (United States)

    Thomas, Renee M; Fedorov, Alexey; Keitz, Benjamin K; Grubbs, Robert H

    2011-12-26

    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

  13. On identifiability of certain latent class models.

    NARCIS (Netherlands)

    W.N. van Wieringen

    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

  14. 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.

  15. 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

  16. 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

  17. Latent Heating Processes within Tropical Deep Convection

    Science.gov (United States)

    van den Heever, S. C.; Mcgee, C. J.

    2013-12-01

    It has been suggested that latent heating above the freezing level plays an important role in reconciling Riehl and Malkus' Hot Tower Hypothesis (HTH) with observational evidence of diluted tropical deep convective cores. In this study, recent modifications to the HTH have been evaluated through the use of Lagrangian trajectory analysis of deep convective cores simulated using the Regional Atmospheric Modeling System (RAMS), a cloud-resolving model (CRM) with sophisticated microphysical, surface and radiation parameterization schemes. Idealized, high-resolution simulations of a line of tropical convective cells have been conducted. A two-moment microphysical scheme was utilized, and the initial and lateral boundary grid conditions were obtained from a large-domain CRM simulation approaching radiative convective equilibrium. As the tropics are never too far from radiative convective equilibrium, such a framework is useful for investigating the relationships between radiation, thermodynamics and microphysics in tropical convection. Microphysical impacts on latent heating and equivalent potential temperature (θe) have been analyzed along trajectories ascending within convective regions. Changes in θe along backward trajectories are partitioned into contributions from latent heating due to ice processes and a residual term that is shown to be an approximate representation of mixing. It is apparent from the CRM simulations that mixing with dry environmental air decreases θe along ascending trajectories below the freezing level, while latent heating due to freezing and vapor deposition increase θe above the freezing level. The along-trajectory contributions to latent heating from cloud nucleation, condensation, evaporation, freezing, deposition, and sublimation have also been quantified. Finally, the source regions of trajectories reaching the upper troposphere have been identified. The analysis indicates that while much of the air ascending within convective

  18. The Latent Speaker: Attaining Adult Fluency in an Endangered Language

    Science.gov (United States)

    Basham, Charlotte; Fathman, Ann

    2008-01-01

    This paper focuses on how latent knowledge of an ancestral or heritage language affects subsequent acquisition by adults. The "latent speaker" is defined as an individual raised in an environment where the ancestral language was spoken but who did not become a speaker of that language. The study examines how attitudes, latent knowledge and…

  19. 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.

  20. Modeling Nonlinear Change via Latent Change and Latent Acceleration Frameworks: Examining Velocity and Acceleration of Growth Trajectories

    Science.gov (United States)

    Grimm, Kevin; Zhang, Zhiyong; Hamagami, Fumiaki; Mazzocco, Michele

    2013-01-01

    We propose the use of the latent change and latent acceleration frameworks for modeling nonlinear growth in structural equation models. Moving to these frameworks allows for the direct identification of "rates of change" and "acceleration" in latent growth curves--information available indirectly through traditional growth curve models when change…

  1. 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.

  2. 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...

  3. Latent phenotypes pervade gene regulatory circuits.

    OpenAIRE

    Payne, Joshua L.; Wagner, Andreas

    2014-01-01

    BACKGROUND Latent phenotypes are non-adaptive byproducts of adaptive phenotypes. They exist in biological systems as different as promiscuous enzymes and genome-scale metabolic reaction networks, and can give rise to evolutionary adaptations and innovations. We know little about their prevalence in the gene expression phenotypes of regulatory circuits, important sources of evolutionary innovations. RESULTS Here, we study a space of more than sixteen million three-gene model regulatory circ...

  4. Latent phenotypes pervade gene regulatory circuits

    OpenAIRE

    Payne, Joshua L.; Wagner, Andreas

    2014-01-01

    Background Latent phenotypes are non-adaptive byproducts of adaptive phenotypes. They exist in biological systems as different as promiscuous enzymes and genome-scale metabolic reaction networks, and can give rise to evolutionary adaptations and innovations. We know little about their prevalence in the gene expression phenotypes of regulatory circuits, important sources of evolutionary innovations. Results Here, we study a space of more than sixteen million three-gene model regulatory circuit...

  5. Modeling Word Relatedness in Latent Dirichlet Allocation

    OpenAIRE

    Wang, Xun

    2014-01-01

    Standard LDA model suffers the problem that the topic assignment of each word is independent and word correlation hence is neglected. To address this problem, in this paper, we propose a model called Word Related Latent Dirichlet Allocation (WR-LDA) by incorporating word correlation into LDA topic models. This leads to new capabilities that standard LDA model does not have such as estimating infrequently occurring words or multi-language topic modeling. Experimental results demonstrate the ef...

  6. 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

  7. Targeting Latent TGFβ release in muscular dystrophy

    OpenAIRE

    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.

    2014-01-01

    Latent 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 proteolyzed, and that proteolysis could be blocked by an antibody to the hinge region. Transgenic mice were generated to carry a bacterial artificial chromos...

  8. 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.

  9. 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...

  10. 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

  11. 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

  12. 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......), the aim of this study was to explore and descriptively compare the application of LCA when using questionnaire summary scores and when using single items to subgrouping of patients based on multidimensional data. MATERIALS AND METHODS: Baseline data from 928 LBP patients in an observational study were...

  13. Latent factors and route choice behaviour

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo

    A behaviourally realistic description of the route choice process should consider variables that are both observable, such as travel time and cost, and unobservable, such as attitudes, perceptions, spatial abilities and network knowledge. This manuscript focuses on automotive route choice behaviour...... and Link Nested Logit. Estimates were produced from model specifications that considered level-of-service, label and facility dummy variables. Moreover, a modelling framework was designed to represent drivers’ choices as affected by the latent constructs extracted with factor analysis. Previous experience...

  14. Repeatability and Reproducibility of Decisions by Latent Fingerprint Examiners

    OpenAIRE

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

    2012-01-01

    The interpretation of forensic fingerprint evidence relies on the expertise of latent print examiners. We tested latent print examiners on the extent to which they reached consistent decisions. This study assessed intra-examiner repeatability by retesting 72 examiners on comparisons of latent and exemplar fingerprints, after an interval of approximately seven months; each examiner was reassigned 25 image pairs for comparison, out of total pool of 744 image pairs. We compare these repeatabilit...

  15. Models of Latent Tuberculosis: Their Salient Features, Limitations, and Development

    OpenAIRE

    Kamlesh Patel; Sarbjit Singh Jhamb; Prati Pal Singh

    2011-01-01

    Latent tuberculosis is a subclinical condition caused by Mycobacterium tuberculosis, which affects about one-third of the population across the world. To abridge the chemotherapy of tuberculosis, it is necessary to have active drugs against latent form of M. tuberculosis. Therefore, it is imperative to devise in vitro and models of latent tuberculosis to explore potential drugs. In vitro models such as hypoxia, nutrient starvation, and multiple stresses are based on adverse conditions encount...

  16. The estimation of serological assays for latent syphilis patients

    OpenAIRE

    Ozoliņš, Dzintars

    2010-01-01

    The estimation of serological assays for latent syphilis patients Abstract The aim of the current investigation is to evaluate how informative are serological assays for syphilis screening, the confirmation diagnosis of the late latent syphilis and for monitoring of the serological activity and treatment efficacy. Conclusions SED, TPHA, ELISA IgG, IgM and syphilis imunoblot IgG are useful for the late latent syphilis screening diagnostics. We do not recommend to use RPR for thi...

  17. 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…

  18. A Latent Transition Analysis Model for Latent-State-Dependent Nonignorable Missingness.

    Science.gov (United States)

    Sterba, Sonya K

    2016-06-01

    Psychologists often use latent transition analysis (LTA) to investigate state-to-state change in discrete latent constructs involving delinquent or risky behaviors. In this setting, latent-state-dependent nonignorable missingness is a potential concern. For some longitudinal models (e.g., growth models), a large literature has addressed extensions to accommodate nonignorable missingness. In contrast, little research has addressed how to extend the LTA to accommodate nonignorable missingness. Here we present a shared parameter LTA that can reduce bias due to latent-state-dependent nonignorable missingness: a parallel-process missing-not-at-random (MNAR-PP) LTA. The MNAR-PP LTA allows outcome process parameters to be interpreted as in the conventional LTA, which facilitates sensitivity analyses assessing changes in estimates between LTA and MNAR-PP LTA. In a sensitivity analysis for our empirical example, previous and current membership in high-delinquency states predicted adolescents' membership in missingness states that had high nonresponse probabilities for some or all items. A conventional LTA overestimated the proportion of adolescents ending up in a low-delinquency state, compared to an MNAR-PP LTA. PMID:25697371

  19. 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...

  20. Infrared Spectroscopic Imaging of Latent Fingerprints and Associated Forensic Evidence

    OpenAIRE

    Chen, Tsoching; Schultz, Zachary D.; Ira W. Levin

    2009-01-01

    Fingerprints reflecting a specific chemical history, such as exposure to explosives, are clearly distinguished from overlapping, and interfering latent fingerprints using infrared spectroscopic imaging techniques and multivariate analysis.

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

    OpenAIRE

    Janusz Czapski

    2013-01-01

    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 an...

  2. A Framework for Reproducible Latent Fingerprint Enhancements.

    Science.gov (United States)

    Carasso, Alfred S

    2014-01-01

    Photoshop processing of latent fingerprints is the preferred methodology among law enforcement forensic experts, but that appproach is not fully reproducible and may lead to questionable enhancements. Alternative, independent, fully reproducible enhancements, using IDL Histogram Equalization and IDL Adaptive Histogram Equalization, can produce better-defined ridge structures, along with considerable background information. Applying a systematic slow motion smoothing procedure to such IDL enhancements, based on the rapid FFT solution of a Lévy stable fractional diffusion equation, can attenuate background detail while preserving ridge information. The resulting smoothed latent print enhancements are comparable to, but distinct from, forensic Photoshop images suitable for input into automated fingerprint identification systems, (AFIS). In addition, this progressive smoothing procedure can be reexamined by displaying the suite of progressively smoother IDL images. That suite can be stored, providing an audit trail that allows monitoring for possible loss of useful information, in transit to the user-selected optimal image. Such independent and fully reproducible enhancements provide a valuable frame of reference that may be helpful in informing, complementing, and possibly validating the forensic Photoshop methodology. PMID:26601028

  3. Distance Dependent Infinite Latent Feature Models

    CERN Document Server

    Gershman, Samuel J; Blei, David M

    2011-01-01

    Latent feature models are widely used to decompose data into a small number of components. Bayesian nonparametric variants of these models, which use the Indian buffet process (IBP) as a prior over latent features, allow the number of features to be determined from the data. We present a generalization of the IBP, the distance dependent Indian buffet process (dd-IBP), for modeling non-exchangeable data. It relies on a distance function defined between data points, biasing nearby data to share more features. The choice of distance function allows for many kinds of dependencies, including temporal or spatial. Further, the original IBP is a special case of the dd-IBP. In this paper, we develop the dd-IBP and theoretically characterize the distribution of how features are shared between data. We derive a Markov chain Monte Carlo sampler for a linear Gaussian model with a dd-IBP prior and study its performance on several data sets for which exchangeability is not a reasonable assumption.

  4. 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.

  5. Ensayo de Primera Ola del Factor de Transferencia (HEBERTRANS

    Directory of Open Access Journals (Sweden)

    Lizet Aldana Velazco

    2004-01-01

    Full Text Available El Factor de Transferencia es un agente natural que aumenta la capacidad para combatir las enfermedades y mejorar la calidad de vida, ha sido usado éxitosamente para tratar enfermedades virales, parasitarias, neurológicas, micóticas y autoinmunes y también utilizado en pacientes que no responden a prescripciones convencionales o que desarrollan reacciones de toxicidad severas a estas. Este producto obtenido a partir de células sin inducir (por el virus Sendai constituye una nueva y muy apropiada formulación teniendo en cuenta el método de obtención. La dosis terapéutica en humanos es de 1 mg/mL y su frecuencia de administración está asociada a la patología del paciente. Por su gran importancia para su uso en humanos, se realizó un ensayo toxicológico (toxicología aguda, para determinar la seguridad del producto. Se utilizaron tres dosis superiores a la terapéutica. Se realizaron observaciones clínicas diarias y determinaciones del peso corporal de forma semanal. Transcurrida la fase experimental (14 d, se realizó el sacrificio de los animales, todo lo cual se llevó a cabo cumpliendo las normas éticas, con análisis macroscópicos y microscópicos de órganos relacionados con el sistema hemolinfopoyético y el hígado. Al comparar los resultados de los grupos tratados con el placebo, no se observaron diferencias significativas en el peso corporal ni se reportaron efectos adversos en los órganos estudiados, lo que permitió concluir que la nueva formulación no resulta tóxica.

  6. 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…

  7. Hypothesis Generation in Latent Growth Curve Modeling Using Principal Components

    Science.gov (United States)

    Davison, Mark L.

    2008-01-01

    While confirmatory latent growth curve analyses provide procedures for testing hypotheses about latent growth curves underlying data, one must first derive hypotheses to be tested. It is argued that such hypotheses should be generated from a combination of theory and exploratory data analyses. An exploratory components analysis is described and…

  8. Evaluating Latent Growth Curve Models Using Individual Fit Statistics

    Science.gov (United States)

    Coffman, Donna L.; Millsap, Roger E.

    2006-01-01

    The usefulness of assessing individual fit in latent growth curve models was examined. The study used simulated data based on an unconditional and a conditional latent growth curve model with a linear component and a small quadratic component and a linear model was fit to the data. Then the overall fit of linear and quadratic models to these data…

  9. Intercept Centering and Time Coding in Latent Difference Score Models

    Science.gov (United States)

    Grimm, Kevin J.

    2012-01-01

    Latent difference score (LDS) models combine benefits derived from autoregressive and latent growth curve models allowing for time-dependent influences and systematic change. The specification and descriptions of LDS models include an initial level of ability or trait plus an accumulation of changes. A limitation of this specification is that the…

  10. 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…

  11. A latent variable transformation model approach for exploring dysphagia.

    Science.gov (United States)

    Snavely, Anna C; Harrington, David P; Li, Yi

    2014-11-10

    Multiple outcomes are often collected in applications where the quantity of interest cannot be measured directly or is difficult or expensive to measure. In a head and neck cancer study conducted at Dana-Farber Cancer Institute, the investigators wanted to determine the effect of clinical and treatment factors on unobservable dysphagia through collected multiple outcomes of mixed types. Latent variable models are commonly adopted in this setting. These models stipulate that multiple collected outcomes are conditionally independent given the latent factor. Mixed types of outcomes (e.g., continuous vs. ordinal) and censored outcomes present statistical challenges, however, as a natural analog of the multivariate normal distribution does not exist for mixed data. Recently, Lin et al. proposed a semiparametric latent variable transformation model for mixed outcome data; however, it may not readily accommodate event time outcomes where censoring is present. In this paper, we extend the work of Lin et al. by proposing both semiparametric and parametric latent variable models that allow for the estimation of the latent factor in the presence of measurable outcomes of mixed types, including censored outcomes. Both approaches allow for a direct estimate of the treatment (or other covariate) effect on the unobserved latent variable, greatly enhancing the interpretability of the models. The semiparametric approach has the added advantage of allowing the relationship between the measurable outcomes and latent variables to be unspecified, rendering more robust inference. The parametric and semiparametric models can also be used together, providing a comprehensive modeling strategy for complicated latent variable problems. PMID:24974798

  12. 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…

  13. 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

  14. 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...

  15. 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…

  16. 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

  17. An overview of latent Markov models for longitudinal categorical data

    CERN Document Server

    Bartolucci, F; Pennoni, F

    2010-01-01

    We provide a comprehensive overview of latent Markov (LM) models for the analysis of longitudinal categorical data. The main assumption behind these models is that the response variables are conditionally independent given a latent process which follows a first-order Markov chain. We first illustrate the basic LM model in which the conditional distribution of each response variable given the corresponding latent variable and the initial and transition probabilities of the latent process are unconstrained. For this model we also illustrate in detail maximum likelihood estimation through the Expectation-Maximization algorithm, which may be efficiently implemented by recursions known in the hidden Markov literature. We then illustrate several constrained versions of the basic LM model, which make the model more parsimonious and allow us to include and test hypotheses of interest. These constraints may be put on the conditional distribution of the response variables given the latent process (measurement model) or...

  18. 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.

  19. Sequential Inference for Latent Force Models

    CERN Document Server

    Hartikainen, Jouni

    2012-01-01

    Latent force models (LFMs) are hybrid models combining mechanistic principles with non-parametric components. In this article, we shall show how LFMs can be equivalently formulated and solved using the state variable approach. We shall also show how the Gaussian process prior used in LFMs can be equivalently formulated as a linear statespace model driven by a white noise process and how inference on the resulting model can be efficiently implemented using Kalman filter and smoother. Then we shall show how the recently proposed switching LFM can be reformulated using the state variable approach, and how we can construct a probabilistic model for the switches by formulating a similar switching LFM as a switching linear dynamic system (SLDS). We illustrate the performance of the proposed methodology in simulated scenarios and apply it to inferring the switching points in GPS data collected from car movement data in urban environment.

  20. 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.

  1. 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).

  2. 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.

  3. 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.

  4. Impact of latent infection treatment in indigenous populations.

    Science.gov (United States)

    Yuhara, Lucia Suemi; Sacchi, Flávia Patussi Correia; Croda, Julio

    2013-01-01

    The aims of the present study were to identify risk factors associated with latent tuberculosis (TB), examine the development of active disease among contacts, and assess the effectiveness of treating latent infection in indigenous Brazilians from January 2006 to December 2011. This was a retrospective study consisting of 1,371 tuberculosis contacts, 392 of whom underwent treatment for latent infection. Morbidity-from-TB data were obtained from the Information System for Disease Notification (SINAN) database, and the contacts' data were collected from the clinical records using forms employed by Special Department of Indigenous Health (SESAI) multidisciplinary teams, according to SESAI's instructions. The variables that were associated with latent infection among the contacts were age (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.02-1.04) and close contact with a smear-positive index case (OR: 2.26, 95% CI: 1.59-3.22). The variables associated with the development of active TB among the contacts were a tuberculin skin test (TST) ≥10 mm (relative risk [RR]: 1.12, 95% CI: 1.07-1.17), age (RR: 1.01, 95% CI: 1.00-1.03), and treatment of latent infection (RR: 0.03, 95% CI: 0.01-0.27). The estimated number of latent infection treatments needed to prevent one case of active TB among the contacts was 51 treatments (95% CI: 33-182). In contacts with TST ≥10 mm, 10 (95% CI: 6-19) latent infection treatments were necessary to prevent one case of active TB. Age and close contact with a smear-positive index case were associated with latent TB. Screening with TST is a high priority among individuals contacting smear-positive index cases. Age and TST are associated with the development of active TB among contacts, and treatment of latent infection is an effective measure to control TB in indigenous communities. PMID:23936264

  5. Impact of latent infection treatment in indigenous populations.

    Directory of Open Access Journals (Sweden)

    Lucia Suemi Yuhara

    Full Text Available The aims of the present study were to identify risk factors associated with latent tuberculosis (TB, examine the development of active disease among contacts, and assess the effectiveness of treating latent infection in indigenous Brazilians from January 2006 to December 2011. This was a retrospective study consisting of 1,371 tuberculosis contacts, 392 of whom underwent treatment for latent infection. Morbidity-from-TB data were obtained from the Information System for Disease Notification (SINAN database, and the contacts' data were collected from the clinical records using forms employed by Special Department of Indigenous Health (SESAI multidisciplinary teams, according to SESAI's instructions. The variables that were associated with latent infection among the contacts were age (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.02-1.04 and close contact with a smear-positive index case (OR: 2.26, 95% CI: 1.59-3.22. The variables associated with the development of active TB among the contacts were a tuberculin skin test (TST ≥10 mm (relative risk [RR]: 1.12, 95% CI: 1.07-1.17, age (RR: 1.01, 95% CI: 1.00-1.03, and treatment of latent infection (RR: 0.03, 95% CI: 0.01-0.27. The estimated number of latent infection treatments needed to prevent one case of active TB among the contacts was 51 treatments (95% CI: 33-182. In contacts with TST ≥10 mm, 10 (95% CI: 6-19 latent infection treatments were necessary to prevent one case of active TB. Age and close contact with a smear-positive index case were associated with latent TB. Screening with TST is a high priority among individuals contacting smear-positive index cases. Age and TST are associated with the development of active TB among contacts, and treatment of latent infection is an effective measure to control TB in indigenous communities.

  6. The latent rationality of risky decisions

    International Nuclear Information System (INIS)

    The general question of rationality has changed from the old-fashioned difference of means and ends to the modern difference of system and environment. Organizations as social systems producing and reproducing decisions translate this difference into the difference of stability and variety. The question then is: In which way can the difference between stability and variety express rationality? - In the temporal dimension of risk-taking, re-entries may be expressed as 'present futures' or 'future presences'. These expressions indicate both: The irresolvable uncertainty of any risk-taking, indicated by open futures, and its boundedness by self-application of distinctions, e.g. projected futures from the background of a known past. - In the material dimension of risk-taking, re-entries may be expressed as 'stable flexibility' or 'flexible stability'. Again, these expressions indicate both: The irresolvable uncertainty of any risk-taking, indicted by open flexibilities, and its boundedness by self-application of distinctions, e.g. flexibility and stability after learning the respective costs of the single options. In the social dimension of risk-taking, re-entries may be expressed as 'pragmatic dissent' or 'controversial pragmatism'. Again, these expressions indicate both: The irresolvable uncertainty of any risk-taking, indicated by open dissent or controversies, and its boundedness by self-application of distinctions, e.g. pragmatic agreements and irresolvable dissent. Again, all three asymmetries represent re-entries. The built-in preferences simply do not work without the subtleties of re-entries, at least when these processes are described by sociologically informed observers. Who else should know that he or she is operating on the basis of something called re-entries? In everyday life communication, no one sees a thing like that since every observation has an in-built bias for one side of a distinction. So rationality will stay latent as the operation of re

  7. 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

  8. 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.

  9. 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.

  10. Neuropsychiatric manifestations of latent toxoplasmosis on mothers and their offspring.

    Science.gov (United States)

    Abdoli, Amir; Dalimi, Abdolhossein; Arbabi, Mohsen; Ghaffarifar, Fatemeh

    2014-09-01

    Toxoplasmosis is one of the most common parasitic diseases worldwide. It is estimated that approximately one-third of the world's population is latently infected. Infection generally occurs via oral the route and maternal transmission. Damage of the central nervous system is one of the most serious consequences of congenital toxoplasmosis. Moreover, recent investigations proposed that acute and sub-acute congenital toxoplasmosis as well as latent toxoplasmosis during pregnancy; play various roles in the etiology of different neuropsychiatric disorders in mothers and their offspring. This paper reviews new findings about the role of latent toxoplasmosis in the etiology of various neuropsychiatric disorders in mothers and their offspring.

  11. 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.

  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. PMID:26528550

  13. 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.

  14. 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.

  15. 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.

  16. 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).

  17. 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.

  18. Latent tuberculosis in nursing professionals of a Brazilian hospital

    Directory of Open Access Journals (Sweden)

    Valim Andréia

    2011-05-01

    Full Text Available Abstract Tuberculosis (TB is considered an occupational disease among health-care workers (HCWs. Direct contact with TB patients leads to an increased risk to become latently infected by Mycobacterium tuberculosis. The objective of this study is to estimate the prevalence of latent M. tuberculosis minfection among nursing professionals of a hospital in Rio Grande do Sul, Brazil, assessed by tuberculin skin test (TST. From November 2009 to May 2010, latent M. tuberculosis infection was assessed by TST in 55 nursing professionals. Epidemiological information was collected using a standardized questionnaire. A positive TST result (> or = 10 mm was observed in 47.3% of the HCWs tested. There was no significant difference in TST positivity when duration of employment or professional category (technician or nurse was evaluated. The results of this work reinforce the need for control measures to prevent latent M. tuberculosis infection among nursing professionals at the hospital where the study was conducted.

  19. 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.

  20. 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.

  1. 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.

  2. Pathogenesis, Immunology, and Diagnosis of Latent Mycobacterium tuberculosis Infection

    Directory of Open Access Journals (Sweden)

    Suhail Ahmad

    2011-01-01

    Full Text Available Phagocytosis of tubercle bacilli by antigen-presenting cells in human lung alveoli initiates a complex infection process by Mycobacterium tuberculosis and a potentially protective immune response by the host. M. tuberculosis has devoted a large part of its genome towards functions that allow it to successfully establish latent or progressive infection in the majority of infected individuals. The failure of immune-mediated clearance is due to multiple strategies adopted by M. tuberculosis that blunt the microbicidal mechanisms of infected immune cells and formation of distinct granulomatous lesions that differ in their ability to support or suppress the persistence of viable M. tuberculosis. In this paper, current understanding of various immune processes that lead to the establishment of latent M. tuberculosis infection, bacterial spreading, persistence, reactivation, and waning or elimination of latent infection as well as new diagnostic approaches being used for identification of latently infected individuals for possible control of tuberculosis epidemic are described.

  3. Assessing phenotypic correlation through the multivariate phylogenetic latent liability model

    OpenAIRE

    Cybis, Gabriela B; Janet S Sinsheimer; Bedford, Trevor; Alison E Mather; Lemey, Philippe; Suchard, Marc A.

    2015-01-01

    © Institute of Mathematical Statistics, 2015. Understanding which phenotypic traits are consistently correlated throughout evolution is a highly pertinent problem in modern evolutionary biology. Here, we propose a multivariate phylogenetic latent liability model for assessing the correlation between multiple types of data, while simultaneously controlling for their unknown shared evolutionary history informed through molecular sequences. The latent formulation enables us to consider in a sing...

  4. 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.

  5. The latent effect of inertia in the modal choice

    DEFF Research Database (Denmark)

    Cherchi, Elisabetta; Meloni, Italo; Ortúzar, Juan de Dios

    2014-01-01

    revealed and stated mode choice preferences collected in Cagliari (Italy). We found a significant latent inertia in the revealed preference data, indicating that inertia affects the initial conditions. The latent inertia is revealed by the frequency of past behaviour but the effect of trip frequency is...... somehow different from the effect of the habitual use of a given mode, indicating that it is important to distinguish these two effects....

  6. 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.

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

    OpenAIRE

    Nidhi Dwivedi; Akhil Agarwal; Bina Kashyap; Vineet Raj; Shaleen Chandra

    2013-01-01

    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 sprinkl...

  8. 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.

  9. Del Piero

    OpenAIRE

    Umbaca, Enzo

    2015-01-01

    Rifacendosi al “Pinturicchio”, epiteto con cui Gianni Agnelli consacrava il calciatore Alessandro Del Piero un “artista del calcio”, Enzo Umbaca scrisse al popolare personaggio invitandolo a collaborare ad una performance durante la quale Pinturicchio-Del Piero avrebbe affrescato il muro di una galleria torinese calciando un pallone macchiato di grafite contro un muro sul quale è appesa la copia di un opera del Pinturicchio.

  10. Función de las metalotioneínas en la patogenia de la encefalomielitis autoinmune experimental y de la esclerosis múltiple. Implicaciones terapéuticas

    OpenAIRE

    Espejo Ruiz, Carmen

    2005-01-01

    [spa] La esclerosis múltiple (EM) es una enfermedad crónica, inflamatoria y desmielinizante del sistema nervioso central (SNC) siendo la principal causa de discapacidad en adultos jóvenes después de los traumatismos. Su prevalencia en nuestra área geográfica es aproximadamente 60-70 pacientes cada 100.000 habitantes. La causa de la enfermedad es aún desconocida y se han implicado tanto factores genéticos como ambientales. Se considera que es una enfermedad mediada por el sistema inmunitario, ...

  11. Incorporating comorbidities into latent treatment pattern mining for clinical pathways.

    Science.gov (United States)

    Huang, Zhengxing; Dong, Wei; Ji, Lei; He, Chunhua; Duan, Huilong

    2016-02-01

    In healthcare organizational settings, the design of a clinical pathway (CP) is challenging since patients following a particular pathway may have not only one single first-diagnosis but also several typical comorbidities, and thus it requires different disciplines involved to put together their partial knowledge about the overall pathway. Although many data mining techniques have been proposed to discover latent treatment information for CP analysis and reconstruction from a large volume of clinical data, they are specific to extract nontrivial information about the therapy and treatment of the first-diagnosis. The influence of comorbidities on adopting essential treatments is crucial for a pathway but has seldom been explored. This study proposes to extract latent treatment patterns that characterize essential treatments for both first-diagnosis and typical comorbidities from the execution data of a pathway. In particular, we propose a generative statistical model to extract underlying treatment patterns, unveil the latent associations between diagnosis labels (including both first-diagnosis and comorbidities) and treatments, and compute the contribution of comorbidities in these patterns. The proposed model extends latent Dirichlet allocation with an additional layer for diagnosis modeling. It first generates a set of latent treatment patterns from diagnosis labels, followed by sampling treatments from each pattern. We verify the effectiveness of the proposed model on a real clinical dataset containing 12,120 patient traces, which pertain to the unstable angina CP. Three treatment patterns are discovered from data, indicating latent correlations between comorbidities and treatments in the pathway. In addition, a possible medical application in terms of treatment recommendation is provided to illustrate the potential of the proposed model. Experimental results indicate that our approach can discover not only meaningful latent treatment patterns exhibiting

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Models of latent tuberculosis: their salient features, limitations, and development.

    Science.gov (United States)

    Patel, Kamlesh; Jhamb, Sarbjit Singh; Singh, Prati Pal

    2011-07-01

    Latent tuberculosis is a subclinical condition caused by Mycobacterium tuberculosis, which affects about one-third of the population across the world. To abridge the chemotherapy of tuberculosis, it is necessary to have active drugs against latent form of M. tuberculosis. Therefore, it is imperative to devise in vitro and models of latent tuberculosis to explore potential drugs. In vitro models such as hypoxia, nutrient starvation, and multiple stresses are based on adverse conditions encountered by bacilli in granuloma. Bacilli experience oxygen depletion condition in hypoxia model, whereas the nutrient starvation model is based on deprivation of total nutrients from a culture medium. In the multiple stress model dormancy is induced by more than one type of stress. In silico mathematical models have also been developed to predict the interactions of bacilli with the host immune system and to propose structures for potential anti tuberculosis compounds. Besides these in vitro and in silico models, there are a number of in vivo animal models like mouse, guinea pig, rabbit, etc. Although they simulate human latent tuberculosis up to a certain extent but do not truly replicate human infection. All these models have their inherent merits and demerits. However, there is no perfect model for latent tuberculosis. Therefore, it is imperative to upgrade and refine existing models or develop a new model. However, battery of models will always be a better alternative to any single model as they will complement each other by overcoming their limitations. PMID:22219558

  18. Models of latent tuberculosis: Their salient features, limitations, and development

    Directory of Open Access Journals (Sweden)

    Kamlesh Patel

    2011-01-01

    Full Text Available Latent tuberculosis is a subclinical condition caused by Mycobacterium tuberculosis, which affects about one-third of the population across the world. To abridge the chemotherapy of tuberculosis, it is necessary to have active drugs against latent form of M. tuberculosis. Therefore, it is imperative to devise in vitro and models of latent tuberculosis to explore potential drugs. In vitro models such as hypoxia, nutrient starvation, and multiple stresses are based on adverse conditions encountered by bacilli in granuloma. Bacilli experience oxygen depletion condition in hypoxia model, whereas the nutrient starvation model is based on deprivation of total nutrients from a culture medium. In the multiple stress model dormancy is induced by more than one type of stress. In silico mathematical models have also been developed to predict the interactions of bacilli with the host immune system and to propose structures for potential anti tuberculosis compounds. Besides these in vitro and in silico models, there are a number of in vivo animal models like mouse, guinea pig, rabbit, etc. Although they simulate human latent tuberculosis up to a certain extent but do not truly replicate human infection. All these models have their inherent merits and demerits. However, there is no perfect model for latent tuberculosis. Therefore, it is imperative to upgrade and refine existing models or develop a new model. However, battery of models will always be a better alternative to any single model as they will complement each other by overcoming their limitations.

  19. 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.

  20. 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. PMID:26895283

  1. 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.

  2. 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.

  3. 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

  4. Efficient Latent Variable Graphical Model Selection via Split Bregman Method

    CERN Document Server

    Ye, Gui-Bo; Chen, Yifei; Xie, Xiaohui

    2011-01-01

    We consider the problem of covariance matrix estimation in the presence of latent variables. Under suitable conditions, it is possible to learn the marginal covariance matrix of the observed variables via a tractable convex program, where the concentration matrix of the observed variables is decomposed into a sparse matrix (representing the graphical structure of the observed variables) and a low rank matrix (representing the marginalization effect of latent variables). We present an efficient first-order method based on split Bregman to solve the convex problem. The algorithm is guaranteed to converge under mild conditions. We show that our algorithm is significantly faster than the state-of-the-art algorithm on both artificial and real-world data. Applying the algorithm to a gene expression data involving thousands of genes, we show that most of the correlation between observed variables can be explained by only a few dozen latent factors.

  5. 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.

  6. 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

  7. Interexaminer variation of minutia markup on latent fingerprints.

    Science.gov (United States)

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

    2016-07-01

    Latent print examiners often differ in the number of minutiae they mark during analysis of a latent, and also during comparison of a latent with an exemplar. Differences in minutia counts understate interexaminer variability: examiners' markups may have similar minutia counts but differ greatly in which specific minutiae were marked. We assessed variability in minutia markup among 170 volunteer latent print examiners. Each provided detailed markup documenting their examinations of 22 latent-exemplar pairs of prints randomly assigned from a pool of 320 pairs. An average of 12 examiners marked each latent. The primary factors associated with minutia reproducibility were clarity, which regions of the prints examiners chose to mark, and agreement on value or comparison determinations. In clear areas (where the examiner was "certain of the location, presence, and absence of all minutiae"), median reproducibility was 82%; in unclear areas, median reproducibility was 46%. Differing interpretations regarding which regions should be marked (e.g., when there is ambiguity in the continuity of a print) contributed to variability in minutia markup: especially in unclear areas, marked minutiae were often far from the nearest minutia marked by a majority of examiners. Low reproducibility was also associated with differences in value or comparison determinations. Lack of standardization in minutia markup and unfamiliarity with test procedures presumably contribute to the variability we observed. We have identified factors accounting for interexaminer variability; implementing standards for detailed markup as part of documentation and focusing future training efforts on these factors may help to facilitate transparency and reduce subjectivity in the examination process. PMID:27046517

  8. 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.

  9. Manifest latent nystagmus: a case of sensori-motor switching.

    Science.gov (United States)

    Abadi, Richard; Clement, Richard; Theodorou, Theofana; Scallan, Columba

    2008-01-01

    Latent nystagmus (LN) and manifest latent nystagmus (MLN) are closely associated with early visual deprivation and strabismus. In both cases, the eyes oscillate horizontally in an involuntary manner and the fast phases always beat towards the attending or fixing eye. By simultaneously recording eye movements during the dichoptic viewing of dissimilar visual stimuli we present evidence that MLN offers a unique opportunity to examine the nature of sensori-motor switching. In particular, we show how the nystagmus beat direction is strongly influenced by endogenous and exogenous attention. A model describing the possible mechanisms underpinning the sensori-motor switching is proposed. PMID:18718345

  10. 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

  11. 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

  12. 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.

  13. Symmetry Breaking Analysis of Prism Adaptation's Latent Aftereffect

    Science.gov (United States)

    Frank, Till D.; Blau, Julia J. C.; Turvey, Michael T.

    2012-01-01

    The effect of prism adaptation on movement is typically reduced when the movement at test (prisms off) differs on some dimension from the movement at training (prisms on). Some adaptation is latent, however, and only revealed through further testing in which the movement at training is fully reinstated. Applying a nonlinear attractor dynamic model…

  14. 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...

  15. 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

  16. On Latent Change Model Choice in Longitudinal Studies

    Science.gov (United States)

    Raykov, Tenko; Zajacova, Anna

    2012-01-01

    An interval estimation procedure for proportion of explained observed variance in latent curve analysis is discussed, which can be used as an aid in the process of choosing between linear and nonlinear models. The method allows obtaining confidence intervals for the R[squared] indexes associated with repeatedly followed measures in longitudinal…

  17. 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.

  18. Regime Switching in the Latent Growth Curve Mixture Model

    Science.gov (United States)

    Dolan, Conor V.; Schmittmann, Verena D.; Lubke, Gitta H.; Neale, Michael C.

    2005-01-01

    A linear latent growth curve mixture model is presented which includes switching between growth curves. Switching is accommodated by means of a Markov transition model. The model is formulated with switching as a highly constrained multivariate mixture model and is fitted using the freely available Mx program. The model is illustrated by analyzing…

  19. 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…

  20. Estimation of bulk transfer coefficient for latent heat flux (Ce)

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.

    The bulk transfer coefficient for latent heat flux (Ce) has been estimated over the Arabian Sea from the moisture budget during the pre-monsoon season of 1988. The computations have been made over two regions (A: 0-8 degrees N: 60-68 degrees E: B: 0...

  1. 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.

  2. 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...

  3. 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

  4. Stochastic Collapsed Variational Bayesian Inference for Latent Dirichlet Allocation

    NARCIS (Netherlands)

    J. Foulds; L. Boyles; C. DuBois; P. Smyth; M. Welling

    2013-01-01

    There has been an explosion in the amount of digital text information available in recent years, leading to challenges of scale for traditional inference algorithms for topic models. Recent advances in stochastic variational inference algorithms for latent Dirichlet allocation (LDA) have made it fea

  5. 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…

  6. 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…

  7. QUALITY AS A LATENT VARIABLE IN RECREATION ACCESS ANALYSIS

    OpenAIRE

    Luzar, E. Jane; Gan, Christopher E.C.; Kanjilal, Barun; Messonnier, Mark L.

    1992-01-01

    Recreation trends indicating an increasing demand for quality recreation experiences suggest the need for special consideration of quality in analysis of fee access recreation. By viewing quality as a subjective latent variable, this paper uses a simultaneous equation framework to consider the use of subjective versus objective appraisals of quality in fee-based recreation access analysis.

  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. 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.

  10. 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…

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

    NARCIS (Netherlands)

    J.J. Ebbers; N.M. Wijnberg

    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

  13. Classifying depression in university students by using the latent structure model

    OpenAIRE

    Kawamoto, Shizuka; Kosugi, Koji

    2011-01-01

    The goal of the present study is to reexamine whether the latent structure of depression is dimensional or categorical.Participants comprises 129 undergraduates (76 male and 53 female). The participants completed the Japanese version of the self-rated depression scale. The results, using the latent class model, suggest that: (1) the latent structure of depression is categorical (extracting the four latent classes) and (2) differences in each category are the degree of the depression's symptoms.

  14. 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.

  15. del Nim

    Directory of Open Access Journals (Sweden)

    Arturo Martínez Rodríguez

    2007-01-01

    Full Text Available Dado su uso específico como fuente de insecticidas naturales de fácil biodegradación, entre otras ventajas, el cultivo del árbol Nim ha sido mundialmente extendido en muchas regiones de Asia, África, Australia y América Latina, incluyendo Cuba. La cosecha del fruto del Nim se hace engorrosa debido a la altura que adquieren estos árboles a los pocos años de sembrados, siendo la cosecha mecánica mediante sacudidores de ramas o del tronco, una posible vía de solución práctica de esta problemática. En el presente trabajo se efectúa, mediante la simulación con el empleo de herramientas CAD-3D y programas de análisis por elementos finitos, un análisis modal abarcador de un número importante de modos de vibración del sistema fruto-pedúnculo del Nim. Como resultado del estudio se pudieron recomendar entornos de frecuencias de las vibraciones a aplicar con mejores expectativas durante la cosecha mecanizada de este producto.

  16. Discrete time, discrete state latent Markov modelling for assessing and predicting household acquisitions of financial products

    NARCIS (Netherlands)

    Paas, Leonard J.; Vermunt, Jeroen K.; Bijmolt, Tammo H. A.

    2007-01-01

    The paper demonstrates application of the latent Markov model for assessing developments by individuals through stages of a process. This approach is applied by using a database on ownership of 12 financial products and various demographic variables. The latent Markov model derives latent classes, r

  17. Psychosocial Functioning Problems over Time among High-Risk Youths: A Latent Class Transition Analysis

    Science.gov (United States)

    Dembo, Richard; Wareham, Jennifer; Poythress, Norman; Meyers, Kathleen; Schmeidler, James

    2008-01-01

    The authors report the results of latent class analyses and latent class transition analyses of antisocial behavior risk factors among 137 youths participating in a juvenile diversion program. The study examined the youths' latent classifications using baseline and 1-year follow-up measures of family, peer, education, and mental health risk…

  18. Examining Factor Score Distributions to Determine the Nature of Latent Spaces

    Science.gov (United States)

    Steinley, Douglas; McDonald, Roderick P.

    2007-01-01

    Similarities between latent class models with K classes and linear factor models with K-1 factors are investigated. Specifically, the mathematical equivalence between the covariance structure of the two models is discussed, and a Monte Carlo simulation is performed using generated data that represents both latent factors and latent classes with…

  19. 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.

  20. 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...

  1. 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.

  2. Using Latent Sleepiness to Evaluate an Important Effect of Promethazine

    Science.gov (United States)

    Feiveson, Alan H.; Hayat, Matthew; Vksman, Zalman; Putcha, Laksmi

    2007-01-01

    Astronauts often use promethazine (PMZ) to counteract space motion sickness; however PMZ may cause drowsiness, which might impair cognitive function. In a NASA ground study, subjects received PMZ and their cognitive performance was then monitored over time. Subjects also reported sleepiness using the Karolinska Sleepiness Score (KSS), which ranges from 1 - 9. A problem arises when using KSS to establish an association between true sleepiness and performance because KSS scores tend to overly concentrate on the values 3 (fairly awake) and 7 (moderately tired). Therefore, we defined a latent sleepiness measure as a continuous random variable describing a subject s actual, but unobserved true state of sleepiness through time. The latent sleepiness and observed KSS are associated through a conditional probability model, which when coupled with demographic factors, predicts performance.

  3. FLDA: Latent Dirichlet Allocation Based Unsteady Flow Analysis.

    Science.gov (United States)

    Hong, Fan; Lai, Chufan; Guo, Hanqi; Shen, Enya; Yuan, Xiaoru; Li, Sikun

    2014-12-01

    In this paper, we present a novel feature extraction approach called FLDA for unsteady flow fields based on Latent Dirichlet allocation (LDA) model. Analogous to topic modeling in text analysis, in our approach, pathlines and features in a given flow field are defined as documents and words respectively. Flow topics are then extracted based on Latent Dirichlet allocation. Different from other feature extraction methods, our approach clusters pathlines with probabilistic assignment, and aggregates features to meaningful topics at the same time. We build a prototype system to support exploration of unsteady flow field with our proposed LDA-based method. Interactive techniques are also developed to explore the extracted topics and to gain insight from the data. We conduct case studies to demonstrate the effectiveness of our proposed approach. PMID:26356968

  4. 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.

  5. 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.

  6. Latent progenitor cells as potential regulators for tympanic membrane regeneration

    Science.gov (United States)

    Kim, Seung Won; Kim, Jangho; Seonwoo, Hoon; Jang, Kyung-Jin; Kim, Yeon Ju; Lim, Hye Jin; Lim, Ki-Taek; Tian, Chunjie; Chung, Jong Hoon; Choung, Yun-Hoon

    2015-06-01

    Tympanic membrane (TM) perforation, in particular chronic otitis media, is one of the most common clinical problems in the world and can present with sensorineural healing loss. Here, we explored an approach for TM regeneration where the latent progenitor or stem cells within TM epithelial layers may play an important regulatory role. We showed that potential TM stem cells present highly positive staining for epithelial stem cell markers in all areas of normal TM tissue. Additionally, they are present at high levels in perforated TMs, especially in proximity to the holes, regardless of acute or chronic status, suggesting that TM stem cells may be a potential factor for TM regeneration. Our study suggests that latent TM stem cells could be potential regulators of regeneration, which provides a new insight into this clinically important process and a potential target for new therapies for chronic otitis media and other eardrum injuries.

  7. Asymmetric latent semantic indexing for gene expression experiments visualization.

    Science.gov (United States)

    González, Javier; Muñoz, Alberto; Martos, Gabriel

    2016-08-01

    We propose a new method to visualize gene expression experiments inspired by the latent semantic indexing technique originally proposed in the textual analysis context. By using the correspondence word-gene document-experiment, we define an asymmetric similarity measure of association for genes that accounts for potential hierarchies in the data, the key to obtain meaningful gene mappings. We use the polar decomposition to obtain the sources of asymmetry of the similarity matrix, which are later combined with previous knowledge. Genetic classes of genes are identified by means of a mixture model applied in the genes latent space. We describe the steps of the procedure and we show its utility in the Human Cancer dataset. PMID:27427382

  8. Image Annotation by Latent Community Detection and Multikernel Learning.

    Science.gov (United States)

    Gu, Yun; Qian, Xueming; Li, Qing; Wang, Meng; Hong, Richang; Tian, Qi

    2015-11-01

    Automatic image annotation is an attractive service for users and administrators of online photo sharing websites. In this paper, we propose an image annotation approach that exploits latent semantic community of labels and multikernel learning (LCMKL). First, a concept graph is constructed for labels indicating the relationship between the concepts. Based on the concept graph, semantic communities are explored using an automatic community detection method. For an image to be annotated, a multikernel support vector machine is used to determine the image's latent community from its visual features. Then, a candidate label ranking based approach is determined by intracommunity and intercommunity ranking. Experiments on the NUS-WIDE database and IAPR TC-12 data set demonstrate that LCMKL outperforms some state-of-the-art approaches. PMID:26068319

  9. 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,...

  10. Discovering shared and individual latent structure in multiple time series

    CERN Document Server

    Saria, Suchi; Penn, Anna

    2010-01-01

    This paper proposes a nonparametric Bayesian method for exploratory data analysis and feature construction in continuous time series. Our method focuses on understanding shared features in a set of time series that exhibit significant individual variability. Our method builds on the framework of latent Diricihlet allocation (LDA) and its extension to hierarchical Dirichlet processes, which allows us to characterize each series as switching between latent ``topics'', where each topic is characterized as a distribution over ``words'' that specify the series dynamics. However, unlike standard applications of LDA, we discover the words as we learn the model. We apply this model to the task of tracking the physiological signals of premature infants; our model obtains clinically significant insights as well as useful features for supervised learning tasks.

  11. 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...... interface covering a broad range of non-linear generalized structural equation models is described. The model and software are demonstrated in data of measurements of the serotonin transporter in the human brain. © 2012 Springer-Verlag....

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

    OpenAIRE

    Bajare, Diana; Janis KAZJONOVS; Aleksandrs KORJAKINS

    2016-01-01

    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 adva...

  13. Latent autoimmune diabetes of the adult: current knowledge and uncertainty

    OpenAIRE

    Laugesen, E; Østergaard, J A; Leslie, R D G

    2015-01-01

    Patients with adult-onset autoimmune diabetes have less Human Leucocyte Antigen (HLA)-associated genetic risk and fewer diabetes-associated autoantibodies compared with patients with childhood-onset Type 1 diabetes. Metabolic changes at diagnosis reflect a broad clinical phenotype ranging from diabetic ketoacidosis to mild non-insulin-requiring diabetes, also known as latent autoimmune diabetes of the adult (LADA). This latter phenotype is the most prevalent form of adult-onset autoimmune dia...

  14. Developing Coping Typologies of Minority Adolescents: A Latent Profile Analysis

    OpenAIRE

    Aldridge, Arianna A.; Roesch, Scott C.

    2007-01-01

    Latent profile analysis (LPA) was used to develop a coping typology of minority adolescents (M = 15.5 yrs). A multiethnic sample (n = 354) was recruited from a program aimed at serving low-income students. LPA revealed three distinct coping profiles. The first comprised adolescents who used a number of specific coping strategies at a low level (Low Generic Copers). The second comprised adolescents who emphasized active/approach strategies (e.g., planning; Active Copers). The third comprised a...

  15. Correcting for measurement error in latent variables used as predictors

    OpenAIRE

    Schofield, Lynne Steuerle

    2015-01-01

    This paper represents a methodological-substantive synergy. A new model, the Mixed Effects Structural Equations (MESE) model which combines structural equations modeling and item response theory, is introduced to attend to measurement error bias when using several latent variables as predictors in generalized linear models. The paper investigates racial and gender disparities in STEM retention in higher education. Using the MESE model with 1997 National Longitudinal Survey of Youth data, I fi...

  16. Repeatability and reproducibility of decisions by latent fingerprint examiners.

    Directory of Open Access Journals (Sweden)

    Bradford T Ulery

    Full Text Available The interpretation of forensic fingerprint evidence relies on the expertise of latent print examiners. We tested latent print examiners on the extent to which they reached consistent decisions. This study assessed intra-examiner repeatability by retesting 72 examiners on comparisons of latent and exemplar fingerprints, after an interval of approximately seven months; each examiner was reassigned 25 image pairs for comparison, out of total pool of 744 image pairs. We compare these repeatability results with reproducibility (inter-examiner results derived from our previous study. Examiners repeated 89.1% of their individualization decisions, and 90.1% of their exclusion decisions; most of the changed decisions resulted in inconclusive decisions. Repeatability of comparison decisions (individualization, exclusion, inconclusive was 90.0% for mated pairs, and 85.9% for nonmated pairs. Repeatability and reproducibility were notably lower for comparisons assessed by the examiners as "difficult" than for "easy" or "moderate" comparisons, indicating that examiners' assessments of difficulty may be useful for quality assurance. No false positive errors were repeated (n = 4; 30% of false negative errors were repeated. One percent of latent value decisions were completely reversed (no value even for exclusion vs. of value for individualization. Most of the inter- and intra-examiner variability concerned whether the examiners considered the information available to be sufficient to reach a conclusion; this variability was concentrated on specific image pairs such that repeatability and reproducibility were very high on some comparisons and very low on others. Much of the variability appears to be due to making categorical decisions in borderline cases.

  17. Latent class models for utilisation of health care

    OpenAIRE

    Teresa Bago d’Uva

    2005-01-01

    This paper explores different approaches to econometric modelling of count measures of health care utilisation, with an emphasis on latent class models. A new model is proposed that combines the features of the two most common approaches- the hurdle model and the finite mixture Negative Binomial. Additionally, the panel structure of the data is taken into account. The proposed model is shown to perform better than the existing models for a particular application with data from the RAND Health...

  18. Application of latent variable models to autoimmune diseases clinimetry

    OpenAIRE

    Molano González, Nicolás

    2015-01-01

    Abstract: Clinical manifestations of autoimmune diseases often are presented as presence or absence of certain symptoms, which in the clinical context can be associated with disease severity. Classical measures like number of symptoms present have been used to assess the severity of disease, nevertheless this score does not reflect particular aspects of each symptom in the severity manifestation. In this setting latent variable models are a natural choice to address the pro...

  19. CRISPR-mediated Activation of Latent HIV-1 Expression.

    Science.gov (United States)

    Limsirichai, Prajit; Gaj, Thomas; Schaffer, David V

    2016-03-01

    Complete eradication of HIV-1 infection is impeded by the existence of cells that harbor chromosomally integrated but transcriptionally inactive provirus. These cells can persist for years without producing viral progeny, rendering them refractory to immune surveillance and antiretroviral therapy and providing a permanent reservoir for the stochastic reactivation and reseeding of HIV-1. Strategies for purging this latent reservoir are thus needed to eradicate infection. Here, we show that engineered transcriptional activation systems based on CRISPR/Cas9 can be harnessed to activate viral gene expression in cell line models of HIV-1 latency. We further demonstrate that complementing Cas9 activators with latency-reversing compounds can enhance latent HIV-1 transcription and that epigenome modulation using CRISPR-based acetyltransferases can also promote viral gene activation. Collectively, these results demonstrate that CRISPR systems are potentially effective tools for inducing latent HIV-1 expression and that their use, in combination with antiretroviral therapy, could lead to improved therapies for HIV-1 infection. PMID:26607397

  20. 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%).

  1. 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.

  2. Latent subspace sparse representation-based unsupervised domain adaptation

    Science.gov (United States)

    Shuai, Liu; Sun, Hao; Zhao, Fumin; Zhou, Shilin

    2015-12-01

    In this paper, we introduce and study a novel unsupervised domain adaptation (DA) algorithm, called latent subspace sparse representation based domain adaptation, based on the fact that source and target data that lie in different but related low-dimension subspaces. The key idea is that each point in a union of subspaces can be constructed by a combination of other points in the dataset. In this method, we propose to project the source and target data onto a common latent generalized subspace which is a union of subspaces of source and target domains and learn the sparse representation in the latent generalized subspace. By employing the minimum reconstruction error and maximum mean discrepancy (MMD) constraints, the structure of source and target domain are preserved and the discrepancy is reduced between the source and target domains and thus reflected in the sparse representation. We then utilize the sparse representation to build a weighted graph which reflect the relationship of points from the different domains (source-source, source- target, and target-target) to predict the labels of the target domain. We also proposed an efficient optimization method for the algorithm. Our method does not need to combine with any classifiers and therefore does not need train the test procedures. Various experiments show that the proposed method perform better than the competitive state of art subspace-based domain adaptation.

  3. 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.

  4. 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. PMID:26898516

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. TRMM observations of latent heat distribution over the Indian summer monsoon region and associated dynamics

    Science.gov (United States)

    Subrahmanyam, Kandula V.; Kishore Kumar, Karanam

    2016-05-01

    The latent heat released/absorbed in the Earth's atmosphere due to phase change of water molecule plays a vital role in various atmospheric processes. It is now well established that the latent heat released in the clouds is the secondary source of energy for driving the atmosphere, the Sun being the primary. In this context, studies on latent heat released in the atmosphere become important to understand the some of the physical processes taking place in the atmosphere. One of the important implications of latent heat release is its role in driving the circulations on various temporal and spatial scales. Realizing the importance of latent heat released in the clouds, a comprehensive study is carried out to understand its role in driving the mesoscale circulation. As Indian summer monsoon (ISM) serves as natural laboratory for studying the clouds and their microphysics, an attempt is made to explore the latent heat distribution over this region using 13 years of Tropical Rainfall Measuring Mission (TRMM) observations. The observed profiles of latent heating over ISM region showed large spatial and temporal variability in the magnitude thus reflecting the presence of organization of convection on mesoscale. The latent profiles in convective and stratiform regions are segregated to study the differences in their interaction with large-scale environment. Various re-analysis dataset were used to examine the role of latent heating distribution on the mesoscale circulation. The significance of the present study lies in establishing the vertical distribution of latent heating and their impact on the background circulation.

  11. 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...

  12. Inducible Cyclic AMP Early Repressor Produces Reactivation of Latent Herpes Simplex Virus Type 1 in Neurons In Vitro

    OpenAIRE

    Colgin, Mark A.; Smith, Roderic L.; Wilcox, Christine L.

    2001-01-01

    Herpes simplex virus type 1 (HSV-1) establishes a latent infection in neurons of the peripheral nervous system. During latent HSV-1 infection, viral gene expression is limited to latency-associated transcripts (LAT). HSV-1 remains latent until an unknown mechanism induces reactivation. The ability of the latent virus to periodically reactivate and be shed is essential to the transmission of disease. In vivo, the stimuli that induce reactivation of latent HSV-1 include stress, fever, and UV da...

  13. Competenca, competencias profesionales y perfil profesional: retrato del perfil del psicopedagogo

    OpenAIRE

    Aznar D??az, Inmaculada; Hinojo Lucena, Francisco Javier; Fern??ndez Mart??n, Francisco D.

    2007-01-01

    Cada d??a est?? adquiriendo mayor peso la formaci??n por competencias en los dis??tintos entornos educativos y laborales. La necesidad de contar con buenos profesionales que ejecuten sus funciones y tareas de un modo eficaz est?? latente en nuestra sociedad. Se requiere, por tanto, un estudio y an??lisis pormenorizado de las diferentes ocupaciones que encontramos en el entorno laboral, extrapolando las caracter??sticas esenciales de cada una de ellas con objeto de obtener una imagen del pe...

  14. Modeling latently infected cell activation: viral and latent reservoir persistence, and viral blips in HIV-infected patients on potent therapy.

    Directory of Open Access Journals (Sweden)

    Libin Rong

    2009-10-01

    Full Text Available Although potent combination therapy is usually able to suppress plasma viral loads in HIV-1 patients to below the detection limit of conventional clinical assays, a low level of viremia frequently can be detected in plasma by more sensitive assays. Additionally, many patients experience transient episodes of viremia above the detection limit, termed viral blips, even after being on highly suppressive therapy for many years. An obstacle to viral eradication is the persistence of a latent reservoir for HIV-1 in resting memory CD4(+ T cells. The mechanisms underlying low viral load persistence, slow decay of the latent reservoir, and intermittent viral blips are not fully characterized. The quantitative contributions of residual viral replication to viral and the latent reservoir persistence remain unclear. In this paper, we probe these issues by developing a mathematical model that considers latently infected cell activation in response to stochastic antigenic stimulation. We demonstrate that programmed expansion and contraction of latently infected cells upon immune activation can generate both low-level persistent viremia and intermittent viral blips. Also, a small fraction of activated T cells revert to latency, providing a potential to replenish the latent reservoir. By this means, occasional activation of latently infected cells can explain the variable decay characteristics of the latent reservoir observed in different clinical studies. Finally, we propose a phenomenological model that includes a logistic term representing homeostatic proliferation of latently infected cells. The model is simple but can robustly generate the multiphasic viral decline seen after initiation of therapy, as well as low-level persistent viremia and intermittent HIV-1 blips. Using these models, we provide a quantitative and integrated prospective into the long-term dynamics of HIV-1 and the latent reservoir in the setting of potent antiretroviral therapy.

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

    OpenAIRE

    Regina M. Innocencio; João H. Romaldini; Ward, Laura S.

    2004-01-01

    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 ...

  16. Latent deprivation among people who are employed, unemployed, or out of the labor force.

    Science.gov (United States)

    Paul, Karsten I; Geithner, Eva; Moser, Klaus

    2009-10-01

    Using a Web-based survey, the authors tested M. Jahoda's (1981, 1982, 1997) latent deprivation model among employed, unemployed, and out-of-the-labor-force (OLF) people. The model predicted that employment is the main provider of 5 specific subconstructs of experience important to mental health: time structure, social contact, collective purpose, status, and activity. As expected, deprivation of these latent functions correlated with distress not only among employed and unemployed people, but also among OLF people. OLF people reported significantly more latent deprivation than did employed people, but they reported significantly less latent deprivation than did unemployed people. Furthermore, latent deprivation mediated the negative effects of unemployment and OLF status on mental health. When the authors statistically controlled the influence of manifest deprivation, the effect of latent deprivation on mental health remained stable. PMID:19943399

  17. 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.

  18. 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

  19. Cosine Based Latent Factor Model for Precision Oriented Recommendation

    OpenAIRE

    Bipul Kumar; Pradip Kumar Bala; Abhishek Srivastava

    2016-01-01

    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 f...

  20. Interpretation of Hospital Nurse Fatigue Using Latent Profile Analysis.

    Science.gov (United States)

    Drake, Diane Ash; Steege, Linsey M Barker

    2016-01-01

    There has been a lack of consensus in the literature related to the conceptualization, definition, and measurement of hospital nurse fatigue. Using latent profile analysis, the Hospital Nurse Force Theory provided a conceptual format to identify 3 profiles of nurse fatigue from subjective reports of hospital patient care nurses in a survey cohort. All fatigue and adaptation variables demonstrated significant inverse relationships. Describing nurse fatigue in profiles that include measures of acute, chronic, physical, and mental fatigue dimensions provided a new and expanded view of nurse fatigue to monitor trends comprehensively and evaluate fatigue risk management strategies. PMID:27490883

  1. 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.

  2. Maximum Likelihood Estimation in Latent Class Models For Contingency Table Data

    OpenAIRE

    Fienberg, S.E.; Hersh, P.; Rinaldo, A.; Zhou, Y

    2007-01-01

    Statistical models with latent structure have a history going back to the 1950s and have seen widespread use in the social sciences and, more recently, in computational biology and in machine learning. Here we study the basic latent class model proposed originally by the sociologist Paul F. Lazarfeld for categorical variables, and we explain its geometric structure. We draw parallels between the statistical and geometric properties of latent class models and we illustrate geometrically the ca...

  3. Low incidence of peach latent mosaic viroid in peach mother blocks in Serbia

    OpenAIRE

    Darko Jevremović; Svetlana Paunović

    2014-01-01

    Peach latent mosaic viroid (PLMVd) is the causal agent of peach latent mosaic disease that is common on peaches and nectarines worldwide. Most of the isolates do not cause any symptoms on the foliage and the disease may be latent for years. A survey to investigate the presence of PLMVd in selected peach mother blocks in 9 Serbian districts was carried out in 2011 through 2013. A total of 315 trees/samples originating from 43 mother blocks, representing 35 p...

  4. Stochastic model of homogeneous coding and latent periodicity in DNA sequences.

    Science.gov (United States)

    Chaley, Maria; Kutyrkin, Vladimir

    2016-02-01

    The concept of latent triplet periodicity in coding DNA sequences which has been earlier extensively discussed is confirmed in the result of analysis of a number of eukaryotic genomes, where latent periodicity of a new type, called profile periodicity, is recognized in the CDSs. Original model of Stochastic Homogeneous Organization of Coding (SHOC-model) in textual string is proposed. This model explains the existence of latent profile periodicity and regularity in DNA sequences. PMID:26656186

  5. Aplicación del análisis factorial confirmatorio a un modelo de medición del rendimiento académico en lectura

    Directory of Open Access Journals (Sweden)

    Andrés Fernández Aráuz

    2015-12-01

    Full Text Available El objetivo de este trabajo es mostrar mediante un ejemplo empírico las diferencias entre las técnicas estadísticas de análisis factorial exploratorio y confirmatorio. Los resultados obtenidos con el análisis factorial confirmatorio muestran que tanto el nivel educativo como el estatus socioeconómico, así como las posesiones del hogar son buenos indicadores para la medición de la variable latente llamada Extracción Socioeconómica. El gusto de los estudiantes por la lectura y la diversidad de lecturas son buenos indicadores de medición para la variable latente de Actitud Personal del estudiante, mientras que la actitud del estudiante hacia el centro educativo no es una buena medición para la variable latente de Actitud Personal. Estos resultados sugieren que los factores inobservables de Extracción Socioeconómica, Estrategias de Lectura y Actitud Personal podrían ser utilizados para evaluar la hipótesis causal del efecto de estas variables sobre el rendimiento educativo de los estudiantes en la prueba de lectura.

  6. 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

    confirmed cases, and used whole genome sequencing to investigate the mutational processes that occur over decades in latent Mtb. We found an estimated mutation rate between 0.2 and 0.3 over 33 years, suggesting that latent Mtb accumulates mutations at rates similar to observations from cases of active......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...

  7. 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.

  8. Chlamydia trachomatis infection induces replication of latent HHV-6.

    Directory of Open Access Journals (Sweden)

    Bhupesh K Prusty

    Full Text Available Human herpesvirus-6 (HHV-6 exists in latent form either as a nuclear episome or integrated into human chromosomes in more than 90% of healthy individuals without causing clinical symptoms. Immunosuppression and stress conditions can reactivate HHV-6 replication, associated with clinical complications and even death. We have previously shown that co-infection of Chlamydia trachomatis and HHV-6 promotes chlamydial persistence and increases viral uptake in an in vitro cell culture model. Here we investigated C. trachomatis-induced HHV-6 activation in cell lines and fresh blood samples from patients having Chromosomally integrated HHV-6 (CiHHV-6. We observed activation of latent HHV-6 DNA replication in CiHHV-6 cell lines and fresh blood cells without formation of viral particles. Interestingly, we detected HHV-6 DNA in blood as well as cervical swabs from C. trachomatis-infected women. Low virus titers correlated with high C. trachomatis load and vice versa, demonstrating a potentially significant interaction of these pathogens in blood cells and in the cervix of infected patients. Our data suggest a thus far underestimated interference of HHV-6 and C. trachomatis with a likely impact on the disease outcome as consequence of co-infection.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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…

  15. 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…

  16. Piecewise Linear-Linear Latent Growth Mixture Models with Unknown Knots

    Science.gov (United States)

    Kohli, Nidhi; Harring, Jeffrey R.; Hancock, Gregory R.

    2013-01-01

    Latent growth curve models with piecewise functions are flexible and useful analytic models for investigating individual behaviors that exhibit distinct phases of development in observed variables. As an extension of this framework, this study considers a piecewise linear-linear latent growth mixture model (LGMM) for describing segmented change of…

  17. Evaluating the Power of Latent Growth Curve Models to Detect Individual Differences in Change

    Science.gov (United States)

    Hertzog, Christopher; von Oertzen, Timo; Ghisletta, Paolo; Lindenberger, Ulman

    2008-01-01

    We evaluated the statistical power of single-indicator latent growth curve models to detect individual differences in change (variances of latent slopes) as a function of sample size, number of longitudinal measurement occasions, and growth curve reliability. We recommend the 2 degree-of-freedom generalized test assessing loss of fit when both…

  18. Modeling Pacing Behavior and Test Speededness Using Latent Growth Curve Models

    Science.gov (United States)

    Kahraman, Nilufer; Cuddy, Monica M.; Clauser, Brian E.

    2013-01-01

    This research explores the usefulness of latent growth curve modeling in the study of pacing behavior and test speededness. Examinee response times from a high-stakes, computerized examination, collected before and after the examination was subjected to a timing change, were analyzed using a series of latent growth curve models to detect…

  19. Using Design-Based Latent Growth Curve Modeling with Cluster-Level Predictor to Address Dependency

    Science.gov (United States)

    Wu, Jiun-Yu; Kwok, Oi-Man; Willson, Victor L.

    2014-01-01

    The authors compared the effects of using the true Multilevel Latent Growth Curve Model (MLGCM) with single-level regular and design-based Latent Growth Curve Models (LGCM) with or without the higher-level predictor on various criterion variables for multilevel longitudinal data. They found that random effect estimates were biased when the…

  20. Modeling Relations among Discrete Developmental Processes: A General Approach to Associative Latent Transition Analysis

    Science.gov (United States)

    Bray, Bethany C.; Lanza, Stephanie T.; Collins, Linda M.

    2010-01-01

    To understand one developmental process, it is often helpful to investigate its relations with other developmental processes. Statistical methods that model development in multiple processes simultaneously over time include latent growth curve models with time-varying covariates, multivariate latent growth curve models, and dual trajectory models.…

  1. Planned Missing Designs to Optimize the Efficiency of Latent Growth Parameter Estimates

    Science.gov (United States)

    Rhemtulla, Mijke; Jia, Fan; Wu, Wei; Little, Todd 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 missingness using a three-form design at each wave such…

  2. 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…

  3. 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

  4. Diagnostic Performance Tests for Suspected Scaphoid Fractures Differ with Conventional and Latent Class Analysis

    NARCIS (Netherlands)

    G.A. Buijze; W.H. Mallee; F.J.P. Beeres; T.E. Hanson; W.O. Johnson; D. Ring

    2011-01-01

    Evaluation of the diagnostic performance characteristics of radiographic tests for diagnosing a true fracture among suspected scaphoid fractures is hindered by the lack of a consensus reference standard. Latent class analysis is a statistical method that takes advantage of unobserved, or latent, cla

  5. Confidence Intervals for a Semiparametric Approach to Modeling Nonlinear Relations among Latent Variables

    Science.gov (United States)

    Pek, Jolynn; Losardo, Diane; Bauer, Daniel J.

    2011-01-01

    Compared to parametric models, nonparametric and semiparametric approaches to modeling nonlinearity between latent variables have the advantage of recovering global relationships of unknown functional form. Bauer (2005) proposed an indirect application of finite mixtures of structural equation models where latent components are estimated in the…

  6. 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 academic…

  7. 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...

  8. 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…

  9. Estimating Latent Variable Interactions with Nonnormal Observed Data: A Comparison of Four Approaches

    Science.gov (United States)

    Cham, Heining; West, Stephen G.; Ma, Yue; Aiken, Leona S.

    2012-01-01

    A Monte Carlo simulation was conducted to investigate the robustness of 4 latent variable interaction modeling approaches (Constrained Product Indicator [CPI], Generalized Appended Product Indicator [GAPI], Unconstrained Product Indicator [UPI], and Latent Moderated Structural Equations [LMS]) under high degrees of nonnormality of the observed…

  10. 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…

  11. An NCME Instructional Module on Latent DIF Analysis Using Mixture Item Response Models

    Science.gov (United States)

    Cho, Sun-Joo; Suh, Youngsuk; Lee, Woo-yeol

    2016-01-01

    The purpose of this ITEMS module is to provide an introduction to differential item functioning (DIF) analysis using mixture item response models. The mixture item response models for DIF analysis involve comparing item profiles across latent groups, instead of manifest groups. First, an overview of DIF analysis based on latent groups, called…

  12. 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…

  13. 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…

  14. 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…

  15. 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. PMID:21264612

  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. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Water content of latent fingerprints - Dispelling the myth.

    Science.gov (United States)

    Kent, Terry

    2016-09-01

    Changing procedures in the handling of rare and precious documents in museums and elsewhere, based on assumptions about constituents of latent fingerprints, have led the author to an examination of available data. These changes appear to have been triggered by one paper using general biological data regarding eccrine sweat production to infer that deposited fingerprints are mostly water. Searching the fingerprint literature has revealed a number of reference works similarly quoting figures for average water content of deposited fingerprints of 98% or more. Whilst accurate estimation is difficult there is no evidence that the residue on fingers could be anything like 98% water, even if there were no contamination from sebaceous glands. Consideration of published analytical data of real fingerprints, and several theoretical considerations regarding evaporation and replenishment rates, indicates a probable initial average water content of a fingerprint, soon after deposition, of 20% or less. PMID:27262684

  2. Chronic stress, leukocyte subpopulations, and humoral response to latent viruses

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, W.; Weisse, C.S.; Reynolds, C.P.; Bowles, C.A.; Baum, A. (Uniformed Services Univ. of the Health Sciences, Bethesda, MD (USA))

    1989-01-01

    Psychological stress has been shown to affect immune system status and function, but most studies of this relationship have focused on acute stress and/or laboratory situations. The present study compared total numbers of leukocytes and lymphocyte subpopulations (determined by flow cytometry) and antibody titers to latent and nonlatent viruses among a group of chronically stressed individuals living near the damaged Three Mile Island (TMI) nuclear power plant with those of a demographically comparable control group. Urinary catecholamine and cortisol levels were also examined. Residents of the TMI area exhibited greater numbers of neutrophils, which were positively correlated with epinephrine levels. The TMI group also exhibited fewer B lymphocytes, T-suppressor/cytotoxic lymphocytes, and natural killer cells. Antibody titers to herpes simplex were significantly different across groups as well, whereas titers to nonlatent rubella virus as well as IgG and IgM levels were comparable.

  3. 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.

  4. Image Hierarchical Representations Models based on Latent Dirichlet Allocation

    Directory of Open Access Journals (Sweden)

    Fushun WANG

    2013-08-01

    Full Text Available Existing image layer representations methods are very feed-forward, and then not able to deal with small ambiguities. A probabilistic model is proposed, and it learns and deduces each layer in that hierarchy together. Therefore, we consider a recursive probabilistic decomposition process, and derive a new yielded method based on recursive Latent Dirichlet Allocation. We show 2 significant properties of the novel probabilistic method: 1 pulsing another hierarchical to represent the enhanced results on that smooth method; 2 an entire Bayesian method beats a feed-forward running of the novel method. The method can be evaluated on a criterion recognition dataset. It takes the probability of recursive decomposition process into account, and obtains multilayer structure pyramid LDA derived model through the derivation. Experiments demonstrate that the novel technique beats existing hierarchical approaches, and present better performance

  5. Fluid Latent Heat Storage Material Using Ethanol Water Mixture

    Science.gov (United States)

    Ohkubo, Hidetoshi; Yasunari, Yuki

    Ethanol water mixture has a liquidus line ( or crystallizing line) and a solidus line (or melting line) that are separated, and therefore it can have both liquid and solid phases existing together. With advances in low temperature technology in recent days, ethanol water mixture is attaching more and more attention as an environment-friendly coolant or as a thermal storage material. In the present study, we observed the crystallization process in the mixture and carried out experiments to evaluate fluidity of the mixture, with the objective of utilizing an ethanol water mixture as a coolant or a thermal energy storage material. Crystal formation and growing process within a minute droplet of a binary mixture was modeled. As a result, we found a novel method to produce a fluid latent heat storage material continuously and an apparent coefficient of viscosity show that rotational speed and solid phase fraction have a strong effect on the fluidity of the mixture.

  6. 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.

  7. 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)

  8. Chronic stress, leukocyte subpopulations, and humoral response to latent viruses

    International Nuclear Information System (INIS)

    Psychological stress has been shown to affect immune system status and function, but most studies of this relationship have focused on acute stress and/or laboratory situations. The present study compared total numbers of leukocytes and lymphocyte subpopulations (determined by flow cytometry) and antibody titers to latent and nonlatent viruses among a group of chronically stressed individuals living near the damaged Three Mile Island (TMI) nuclear power plant with those of a demographically comparable control group. Urinary catecholamine and cortisol levels were also examined. Residents of the TMI area exhibited greater numbers of neutrophils, which were positively correlated with epinephrine levels. The TMI group also exhibited fewer B lymphocytes, T-suppressor/cytotoxic lymphocytes, and natural killer cells. Antibody titers to herpes simplex were significantly different across groups as well, whereas titers to nonlatent rubella virus as well as IgG and IgM levels were comparable

  9. Controlling disasters: recognising latent goals after Hurricane Katrina.

    Science.gov (United States)

    Miller, Lee M

    2012-01-01

    Classic sociological theory can be used to interpret the aftermath of Hurricane Katrina, which made landfall in the United States on 29 August 2005. The delayed and ineffective response to the storm and the subsequent failure of the levees become more understandable when one considers the latent goals of social control in disaster recovery. Constructing the survivors as suspect or criminal and conceptualising the impacts of the disaster as individual problems occurred in order to justify the emphasis on controlling the survivors of Katrina rather than on assisting them. Parallels are drawn here between the disaster response featuring social control efforts and a recent paradigmatic shift in criminal justice from justice to 'risk management'. Recognition of the implicit aims of the inadequate disaster response provides a more complete explanation of why post-Katrina efforts failed to achieve the manifest goals of response and recovery. The conclusion suggests ways to ensure more equitable and just disaster responses. PMID:21623890

  10. Improving knowledge management systems with latent semantic analysis

    International Nuclear Information System (INIS)

    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)

  11. 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...

  12. Latent microsporidial infection in immunocompetent individuals - a longitudinal study.

    Directory of Open Access Journals (Sweden)

    Bohumil Sak

    2011-05-01

    Full Text Available BACKGROUND: Microsporidia (Fungi have been repeatedly identified as the cause of opportunistic infections predominantly in immunodeficient individuals such as AIDS patients. However, the global epidemiology of human microsporidiosis is poorly understood and the ability of microsporidia to survive and multiply in immunocompetent hosts remains unsolved. AIMS: To determine the presence of latent microsporidia infections in apparently healthy humans in the Czech Republic, the authors tested sera, urine and stool originating from fifteen persons within a three month period examined on a weekly basis. METHODS: Sera, stool and urine samples originating from fifteen HIV-negative people at risk with occupational exposure to animals, aged 22-56 years, living in the Czech Republic were tested by indirect immunofluorescence assay (IFA for the presence of specific anti-microsporidial antibodies, standard Calcofluor M2R staining for the detection of microsporidian spores in all urine sediments and stool smears and molecular methods for the microsporidial species determination. RESULTS: Specific anti-microsporidial antibodies were detected in fourteen individuals, asymptomatic Encephalitozoon spp. infection was found in thirteen and E. bieneusi infection was detected in seven of those examined. While E. hellem 1A and E. cuniculi II were the major causative agents identified, seven different genotypes of E. bieneusi were recorded. CONCLUSIONS: These findings clearly show that exposure to microsporidia is common and chronic microsporidiosis is not linked to any clinical manifestation in healthy population. Moreover, our results indicate much higher incidence of microsporidial infections among an apparently healthy population than previously reported. These results open the question about the potential risk of reactivation of latent microsporidiosis in cases of immunosupression causing life-threatening disease.

  13. 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.

  14. Wallboard with Latent Heat Storage for Passive Solar Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kedl, R.J.

    2001-05-31

    Conventional wallboard impregnated with octadecane paraffin [melting point-23 C (73.5 F)] is being developed as a building material with latent heat storage for passive solar and other applications. Impregnation was accomplished simply by soaking the wallboard in molten wax. Concentrations of wax in the combined product as high as 35% by weight can be achieved. Scale-up of the soaking process, from small laboratory samples to full-sized 4- by 8-ft sheets, has been successfully accomplished. The required construction properties of wallboard are maintained after impregnation, that is, it can be painted and spackled. Long-term, high-temperature exposure tests and thermal cycling tests showed no tendency of the paraffin to migrate within the wallboard, and there was no deterioration of thermal energy storage capacity. In support of this concept, a computer model was developed to handle thermal transport and storage by a phase change material (PCM) dispersed in a porous media. The computer model was confirmed by comparison with known analytical solutions and also by comparison with temperatures measured in wallboard during an experimentally generated thermal transient. Agreement between the model and known solution was excellent. Agreement between the model and thermal transient was good, only after the model was modified to allow the PCM to melt over a temperature range, rather than at a specific melting point. When the melting characteristics of the PCM (melting point, melting range, and heat of fusion), as determined from a differential scanning calorimeter plot, were used in the model, agreement between the model and transient data was very good. The confirmed computer model may now be used in conjunction with a building heating and cooling code to evaluate design parameters and operational characteristics of latent heat storage wallboard for passive solar applications.

  15. 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...

  16. A novel approach for latent print identification using accurate overlays to prioritize reference prints.

    Science.gov (United States)

    Gantz, Daniel T; Gantz, Donald T; Walch, Mark A; Roberts, Maria Antonia; Buscaglia, JoAnn

    2014-12-01

    A novel approach to automated fingerprint matching and scoring that produces accurate locally and nonlinearly adjusted overlays of a latent print onto each reference print in a corpus is described. The technology, which addresses challenges inherent to latent prints, provides the latent print examiner with a prioritized ranking of candidate reference prints based on the overlays of the latent onto each candidate print. In addition to supporting current latent print comparison practices, this approach can make it possible to return a greater number of AFIS candidate prints because the ranked overlays provide a substantial starting point for latent-to-reference print comparison. To provide the image information required to create an accurate overlay of a latent print onto a reference print, "Ridge-Specific Markers" (RSMs), which correspond to short continuous segments of a ridge or furrow, are introduced. RSMs are reliably associated with any specific local section of a ridge or a furrow using the geometric information available from the image. Latent prints are commonly fragmentary, with reduced clarity and limited minutiae (i.e., ridge endings and bifurcations). Even in the absence of traditional minutiae, latent prints contain very important information in their ridges that permit automated matching using RSMs. No print orientation or information beyond the RSMs is required to generate the overlays. This automated process is applied to the 88 good quality latent prints in the NIST Special Database (SD) 27. Nonlinear overlays of each latent were produced onto all of the 88 reference prints in the NIST SD27. With fully automated processing, the true mate reference prints were ranked in the first candidate position for 80.7% of the latents tested, and 89.8% of the true mate reference prints ranked in the top ten positions. After manual post-processing of those latents for which the true mate reference print was not ranked first, these frequencies increased to 90

  17. 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.

  18. Detecting Mixtures from Structural Model Differences Using Latent Variable Mixture Modeling: A Comparison of Relative Model Fit Statistics

    Science.gov (United States)

    Henson, James M.; Reise, Steven P.; Kim, Kevin H.

    2007-01-01

    The accuracy of structural model parameter estimates in latent variable mixture modeling was explored with a 3 (sample size) [times] 3 (exogenous latent mean difference) [times] 3 (endogenous latent mean difference) [times] 3 (correlation between factors) [times] 3 (mixture proportions) factorial design. In addition, the efficacy of several…

  19. The role of endoscopic ultrasound (EUS in relation to other imaging modalities in the differential diagnosis between mass forming chronic pancreatitis, autoimmune pancreatitis and ductal pancreatic adenocarcinoma Papel de la endoscopia en relación con otras modalidades de imagen en el diagnóstico diferencial entre pancreatitis crónica en forma de masa, pancreatitis autoinmune y adenocarcinoma pancreático

    Directory of Open Access Journals (Sweden)

    Julio Iglesias-García

    2012-06-01

    Full Text Available Differential diagnosis of solid pancreatic lesions remains as an important clinical challenge, mainly for the differentiation between mass forming chronic pancreatitis, autoimmune pancreatitis and pancreatic adenocarcinoma. Endoscopic ultrasound (EUS, computed tomography (CT and magnetic resonance imaging (MRI can all provide valuable and complementary information in this setting. Among them, EUS has the unique ability to obtain specimens for histopathological diagnosis and can therefore play a crucial role in the evaluation patients with inconclusive findings on initial examinations. Nowadays, new developed techniques associated to EUS, like elastography and contrast enhancement, have shown promising results for the differential diagnosis of these pancreatic lesions.El diagnóstico diferencial de las lesiones sólidas pancreáticas permanece como un reto clínico importante, sobre todo para la diferenciación entre la masa de conformación pancreatitis crónica, pancreatitis autoinmune y el adenocarcinoma de páncreas. Ecografía endoscópica (USE, la tomografía computarizada (TC y la resonancia magnética (MRI pueden proporcionar información valiosa y complementaria en este entorno. Entre ellos, la USE tiene la capacidad única de obtener muestras para diagnóstico histopatológico y por lo tanto, puede desempeñar un papel crucial en la evaluación de los pacientes con resultados poco concluyentes en los exámenes iniciales. Hoy en día, las nuevas técnicas desarrolladas asociadas a la USE, como la elastografía y realce de contraste, han mostrado resultados prometedores para el diagnóstico diferencial de las lesiones pancreáticas.

  20. 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.

  1. 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.

  2. Tratamiento sistémico del penfigoide cicatrizal ocular Systemic treatment of ocular cicatricial pemphigoid

    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.Ocular cicatricial pemphigoid (OCP is a blistering autoimmune disease that can produce severe conjunctival damage. Its response to immunosuppressive treatment is poorly known. We describe a group of 76 patients, 62 women and 14 men. Mean age at diagnosis was 67±14 years old, with a delay to diagnosis of 7.5±10 years. Sixty patients continued their follow up in our services for 19±21 months. Nineteen out of 51 had mild disease, 19 moderate, 5 severe and 8 very severe at onset of treatment. The more frequently prescribed drugs were dapsone, in 35 (23 discontinued it because of adverse effects, and methotrexate in 42 patients, nine of them stopped it. Other patients

  3. Latent autoimmune diabetes of the adult: current knowledge and uncertainty

    Science.gov (United States)

    Laugesen, E; Østergaard, J A; Leslie, R D G

    2015-01-01

    Patients with adult-onset autoimmune diabetes have less Human Leucocyte Antigen (HLA)-associated genetic risk and fewer diabetes-associated autoantibodies compared with patients with childhood-onset Type 1 diabetes. Metabolic changes at diagnosis reflect a broad clinical phenotype ranging from diabetic ketoacidosis to mild non-insulin-requiring diabetes, also known as latent autoimmune diabetes of the adult (LADA). This latter phenotype is the most prevalent form of adult-onset autoimmune diabetes and probably the most prevalent form of autoimmune diabetes in general. Although LADA is associated with the same genetic and immunological features as childhood-onset Type 1 diabetes, it also shares some genetic features with Type 2 diabetes, which raises the question of genetic heterogeneity predisposing to this form of the disease. The potential value of screening patients with adult-onset diabetes for diabetes-associated autoantibodies to identify those with LADA is emphasized by their lack of clinically distinct features, their different natural history compared with Type 2 diabetes and their potential need for a dedicated management strategy. The fact that, in some studies, patients with LADA show worse glucose control than patients with Type 2 diabetes, highlights the need for further therapeutic studies. Challenges regarding classification, epidemiology, genetics, metabolism, immunology, clinical presentation and treatment of LADA were discussed at a 2014 workshop arranged by the Danish Diabetes Academy. The presentations and discussions are summarized in this review, which sets out the current ideas and controversies surrounding this form of diabetes. What’s new? Latent autoimmune diabetes of the adult (LADA) is an autoimmune diabetes defined by adult-onset, presence of diabetes associated autoantibodies, and no insulin treatment requirement for a period after diagnosis. Immunologically, glutamic acid decarboxylase 65 autoantibodies are by far the most

  4. 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.

  5. Coupled latent differential equation with moderators: simulation and application.

    Science.gov (United States)

    Hu, Yueqin; Boker, Steve; Neale, Michael; Klump, Kelly L

    2014-03-01

    Latent differential equations (LDE) use differential equations to analyze time series data. Because of the recent development of this technique, some issues critical to running an LDE model remain. In this article, the authors provide solutions to some of these issues and recommend a step-by-step procedure demonstrated on a set of empirical data, which models the interaction between ovarian hormone cycles and emotional eating. Results indicated that emotional eating is self-regulated. For instance, when people do more emotional eating than normal, they will subsequently tend to decrease their emotional eating behavior. In addition, a sudden increase will produce a stronger tendency to decrease than will a slow increase. We also found that emotional eating is coupled with the cycle of the ovarian hormone estradiol, and the peak of emotional eating occurs after the peak of estradiol. The self-reported average level of negative affect moderates the frequency of eating regulation and the coupling strength between eating and estradiol. Thus, people with a higher average level of negative affect tend to fluctuate faster in emotional eating, and their eating behavior is more strongly coupled with the hormone estradiol. Permutation tests on these empirical data supported the reliability of using LDE models to detect self-regulation and a coupling effect between two regulatory behaviors. PMID:23646992

  6. 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.

  7. 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.

  8. Preparation of fine powdered composite for latent heat storage

    Science.gov (United States)

    Fořt, Jan; Pomaleski, Marina; Trník, Anton; Pavlíková, Milena; Pavlík, Zbyšek

    2016-07-01

    Application of latent heat storage building envelope systems using phase-change materials represents an attractive method of storing thermal energy and has the advantages of high-energy storage density and the isothermal nature of the storage process. This study deals with a preparation of a new type of powdered phase change composite material for thermal energy storage. The idea of a composite is based upon the impregnation of a natural silicate material by a reasonably priced commercially produced pure phase change material and forming the homogenous composite powdered structure. For the preparation of the composite, vacuum impregnation method is used. The particle size distribution accessed by the laser diffraction apparatus proves that incorporation of the organic phase change material into the structure of inorganic siliceous pozzolana does not lead to the clustering of the particles. The compatibility of the prepared composite is characterized by the Fourier transformation infrared analysis (FTIR). Performed DSC analysis shows potential of the developed composite for thermal energy storage that can be easily incorporated into the cement-based matrix of building materials. Based on the obtained results, application of the developed phase change composite can be considered with a great promise.

  9. 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.

  10. 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.

  11. Answer Extraction System Based on Latent Dirichlet Allocation

    Directory of Open Access Journals (Sweden)

    Mohammed A. S. Ali

    2016-04-01

    Full Text Available Question Answering (QA task is still an active area of research in information retrieval. A variety of methods which have been proposed in the literature during the last few decades to solve this task have achieved mixed success. However, such methods developed in the Arabic language are scarce and do not have a good performance record. This is due to the challenges of Arabic language. QA based on Frequently Asked Questions is an important branch of QA in which a question is answered based on pre-answered ones. In this paper, the aim is to build a question answering system that responds to a user inquiry based on pre-answered questions. The proposed approach is based on Latent Dirichlet Allocation. Firstly, the dataset, pairs of questions and associated answers, will be grouped into several clusters of related documents. Next, when a new question to be answered is posed to the system, it,therefore, starts to assign this question to its appropriate cluster, then, use a similarity measure to get the top ten closest possible answers. Preliminary results show that the proposed method is achieving a good level of performance.

  12. Young men's condom use resistance tactics: a latent profile analysis.

    Science.gov (United States)

    Davis, Kelly Cue; Stappenbeck, Cynthia A; Norris, Jeanette; George, William H; Jacques-Tiura, Angela J; Schraufnagel, Trevor J; Kajumulo, Kelly F

    2014-01-01

    Research suggests that many men have used a variety of tactics to avoid using condoms when having sex with women. Guided by previous work demonstrating that men's use of coercive condom resistance tactics was predicted by negative attitudes toward women, inconsistent condom use, multiple partners, and sexual sensation seeking, the current study used latent profile analysis (LPA) to determine whether similar constructs were associated with a variety of resistance tactics. A community sample of 313 moderate-drinking men participated, of whom 80% reported employing at least one condom use resistance tactic since adolescence. The LPA revealed three classes of men. In general, men with the least negative beliefs about women, low levels of sexual sensation seeking and impulsivity, and positive beliefs about condoms (Condom Positive/Low Hostility) reported less use of resistance tactics than men with moderate sexual sensation seeking and impulsivity, negative beliefs about condoms, and moderate (Condom Negative/Moderate Hostility) or high (Condom Negative/High Hostility) negative attitudes about women. The classes also differed in terms of their sexual behaviors. This study demonstrated that sexual risk behavior interventions should not only address the tactics through which men resist using condoms but also tailor these efforts to men's individual characteristics. PMID:23548069

  13. 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...

  14. 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.

  15. del discurso

    Directory of Open Access Journals (Sweden)

    Alexander Mosquera

    2006-01-01

    Full Text Available En varios comunicados quedó reflejada la tensión de la reciente crisis entre Colombia y Venezuela, suscitada a raíz de la captura en diciembre de 2004 de un guerrillero de la FARC en Caracas (Rodrigo Granda. El presente trabajo es un avance de un proyecto de investigación, que persigue como objetivos: 1 describir el discurso implícito en dichos comunicados; 2 identificar los aspectos semánticos y pragmáticos presentes en la confrontación discursiva; y 3 delinear el componente ideológico reflejado en los comunicados. Para el respectivo análisis se siguieron algunos aspectos teóricos y metodológicos de Colle (2000, Bolívar (1998 yMolero de Cabeza (1985. Entre las conclusiones preliminares de este avance se tiene que, con el caso Granda, Colombia recurrió a la vieja política del "fin justifica los medios", a la vez que puso en entredicho el papel de Venezuela en la lucha contra el terrorismo, quizás como respuesta a su política exterior de estrechos vínculos con el gobierno estadounidense

  16. 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...... to encompass a latent class variable as predictor of time-to-event, while using information about latent class membership available from multiple categorical indicators. The expectation-maximization (EM) algorithm is employed to obtain maximum likelihood estimates, and standard errors are calculated based...... 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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,...

  4. 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,...

  5. 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,...

  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. 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.

  8. LTBI: latent tuberculosis infection or lasting immune responses to M. tuberculosis? A TBNET consensus statement

    DEFF Research Database (Denmark)

    Mack, U; Migliori, G B; Sester, M;

    2009-01-01

    Tuberculosis control relies on the identification and preventive treatment of individuals who are latently infected with Mycobacterium tuberculosis. However, direct identification of latent tuberculosis infection is not possible. The diagnostic tests used to identify individuals latently infected...... with M. tuberculosis, the in vivo tuberculin skin test and the ex vivo interferon-gamma release assays (IGRAs), are designed to identify an adaptive immune response against, but not necessarily a latent infection with, M. tuberculosis. The proportion of individuals who truly remain infected with M....... tuberculosis after tuberculin skin test or IGRA conversion is unknown. It is also uncertain how long adaptive immune responses towards mycobacterial antigens persist in the absence of live mycobacteria. Clinical management and public healthcare policies for preventive chemotherapy against tuberculosis could...

  9. 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.

  10. Chemical Composition of Latent Fingerprints by Gas Chromatography-Mass Spectrometry

    Science.gov (United States)

    Hartzell-Baguley, Brittany; Hipp, Rachael E.; Morgan, Neal R.; Morgan, Stephen L.

    2007-01-01

    An experiment in which gas chromatography-mass spectrometry (GC-MS) is used for latent fingerprint extraction and analysis on glass beads or glass slides is conducted. The results determine that the fingerprint residues are gender dependent.

  11. Human Herpesvirus 6 Latently Infects Early Bone Marrow Progenitors In Vivo

    OpenAIRE

    Luppi, Mario; Barozzi, Patrizia; Morris, Christine; Maiorana, Antonio; Garber, Richard; Bonacorsi, Goretta; Donelli, Amedea; Marasca, Roberto; Tabilio, Antonio; Torelli, Giuseppe

    1999-01-01

    We have studied the in vivo tropism of human herpesvirus 6 (HHV-6) for hemopoietic cells in patients with latent HHV-6 infection. Having used a variety of cell purification, molecular, cytogenetic, and immunocytochemical procedures, we report the first evidence that HHV-6 latently infects early bone marrow progenitor cells and that HHV-6 may be transmitted longitudinally to cells which differentiate along the committed pathways.

  12. Variants of psychopathy in adult male offenders: A latent profile analysis.

    Science.gov (United States)

    Mokros, Andreas; Hare, Robert D; Neumann, Craig S; Santtila, Pekka; Habermeyer, Elmar; Nitschke, Joachim

    2015-05-01

    As measured with the Psychopathy Checklist-Revised (PCL-R), psychopathy is a dimensional construct underpinned by 4 correlated factors: Interpersonal, Affective, Lifestyle, and Antisocial. Theorists and clinicians (e.g., Karpman and Arieti) have posited 2 variants of "primary" or "true" psychopathy, both distinct from so-called "secondary" or "pseudopsychopathy." We used latent profile analysis to determine if homogeneous classes exist within a sample of 1,451 male offenders with high PCL-R scores (≥ 27). The 4 PCL-R factors were the dependent variables for clustering. A solution with 3 latent classes showed a better fit to the data than did a unitary model without latent classes. Tentative labels for the latent classes are Manipulative (Latent Class 1 [LC1]), Aggressive (Latent Class 2 [LC2]), and Sociopathic (Latent Class 3 [LC3]). The latter class represented an antisocial group that lacked the emotional detachment observed in the other 2 groups. We propose that LC1 and LC2 reflect phenotypic variations on a theme of the traditional construct of psychopathy, and that LC3 is consistent with conceptions of antisocial personality disorder and sociopathy. Replication and external classification with an independent data set of 497 adult male offenders again yielded clearly separable clusters, as well as meaningful differences or trends among latent classes on education, intelligence, symptoms of antisocial personality disorder, and self-reported psychopathic traits and negative affect. The conceptualization of psychopathy in terms of manipulative and aggressive variants is consistent with clinical theory and is empirically grounded. PMID:25643206

  13. 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.

  14. The Latent Structure of Attention Deficit/Hyperactivity Disorder in an Adult Sample

    OpenAIRE

    Marcus, David K.; Norris, Alyssa L.; Coccaro, Emil F.

    2012-01-01

    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 prevalen...

  15. 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...

  16. Latent profile analysis of healthy schizotypy within the extended psychosis phenotype

    OpenAIRE

    Tabak, Naomi Tuchman; de Mamani, Amy Gina Weisman

    2013-01-01

    Converging evidence suggests that psychosis exists on a continuum, and that even mentally “healthy” individuals may experience subclinical psychotic experiences. However, little research has examined the subjective and psychological well-being of individuals in the putatively healthy end of the continuum. This study explored the latent profile structure of schizotypy in a non-clinical sample and compared subjective and psychological well-being across schizotypy profiles. Latent profile analys...

  17. Genes Expressed in Grapevine Leaves Reveal Latent Wood Infection by the Fungal Pathogen Neofusicoccum parvum

    OpenAIRE

    Czemmel, Stefan; Galarneau, Erin R.; Travadon, Renaud; McElrone, Andrew J.; Cramer, Grant R; Baumgartner, Kendra

    2015-01-01

    Some pathogenic species of the Botryosphaeriaceae have a latent phase, colonizing woody tissues while perennial hosts show no apparent symptoms until conditions for disease development become favorable. Detection of these pathogens is often limited to the later pathogenic phase. The latent phase is poorly characterized, despite the need for non-destructive detection tools and effective quarantine strategies, which would benefit from identification of host-based markers in leaves. Neofusicoccu...

  18. Efficient Reactivation of Latent Herpes Simplex Virus from Mouse Central Nervous System Tissues▿

    OpenAIRE

    Chen, Shih-Heng; Yao, Hui-Wen; Huang, Wen-Yen; Hsu, Kuei-Sen; Lei, Huan-Yao; Shiau, Ai-Li; Chen, Shun-Hua

    2006-01-01

    For decades, numerous ex vivo studies have documented that latent herpes simplex virus (HSV) reactivates efficiently from ganglia, but rarely from the central nervous systems (CNS), of mice when assayed by mincing tissues before explant culture, despite the presence of viral genomes in both sites. Here we show that 88% of mouse brain stems reactivated latent virus when they were dissociated into cell suspensions before ex vivo explant culture. The efficient reactivation of HSV from the mouse ...

  19. Latent feature representation with stacked auto-encoder for AD/MCI diagnosis

    OpenAIRE

    Suk, Heung-Il; Lee, Seong-Whan; Shen, Dinggang

    2013-01-01

    Recently, there have been great interests for computer-aided diagnosis of Alzheimer’s disease (AD) and its prodromal stage, mild cognitive impairment (MCI). Unlike the previous methods that considered simple low-level features such as gray matter tissue volumes from MRI, and mean signal intensities from PET, in this paper, we propose a deep learning-based latent feature representation with a stacked auto-encoder (SAE). We believe that there exist latent non-linear complicated patterns inheren...

  20. ADVERTISING AND RETAIL PROMOTION OF WASHINGTON APPLES: A STRUCTURAL LATENT VARIABLE APPROACH TO PROMOTION EVALUATION

    OpenAIRE

    Richards, Timothy J.; Gao, Xiaoming; Patterson, Paul M.

    1999-01-01

    "Commodity promotion" consists of many activities, each designed to contribute to a consumer's product knowledge or influence tastes. However, both knowledge and tastes are unobservable, or latent, variables influencing demand. This paper specifies a dynamic structural model of fresh fruit demand that treats promotion and other socioeconomic variables as "causal" variables influencing these latent variables. Estimating this state-space model using a Kalman filter approach provides estimates o...

  1. A finite mixture latent trajectory model for modeling ultrarunners' behavior in a 24-hour race

    OpenAIRE

    Bartolucci, Francesco; Murphy, Thomas Brendan

    2015-01-01

    A finite mixture latent trajectory model is developed to study the performance and strategy of runners in a 24-h long ultra running race. The model facilitates clustering of runners based on their speed and propensity to rest and thus reveals the strategies used in the race. Inference for the adopted latent trajectory model is achieved using an expectation-maximization algorithm. Fitting the model to data from the 2013 World Championships reveals three clearly separated clusters of runners wh...

  2. Overexpression of Latent TGFβ Binding Protein 4 in Muscle Ameliorates Muscular Dystrophy through Myostatin and TGFβ

    OpenAIRE

    Kay-Marie Lamar; Sasha Bogdanovich; Gardner, Brandon B.; Gao, Quan Q.; Tamari Miller; Earley, Judy U.; Michele Hadhazy; Vo, Andy H.; Lisa Wren; Molkentin, Jeffery D.; McNally, Elizabeth M.

    2016-01-01

    Latent TGFβ binding proteins (LTBPs) regulate the extracellular availability of latent TGFβ. LTBP4 was identified as a genetic modifier of muscular dystrophy in mice and humans. An in-frame insertion polymorphism in the murine Ltbp4 gene associates with partial protection against muscular dystrophy. In humans, nonsynonymous single nucleotide polymorphisms in LTBP4 associate with prolonged ambulation in Duchenne muscular dystrophy. To better understand LTBP4 and its role in modifying muscular ...

  3. Latent Semantic Indexing and Information Retrieval-A quest with BosSE

    OpenAIRE

    Geiß, Johanna

    2006-01-01

    This master thesis deals with the implementation of a search engine using Latent Semantic Indexing (LSI) called BoSSE. Four different search types were implemented which allow a search for documents or terms similar to a given term, query or document. These search types are evaluated and the importance of term weighting, exclusion of non content words and the right selection of k for the reduction of dimension are discussed. Furthermore, an introduction to Latent Semantic Indexing (LSI) and a...

  4. 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 M.

    2016-09-07

    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.

  5. Invariant Gaussian Process Latent Variable Models and Application in Causal Discovery

    OpenAIRE

    Zhang, Kun; Schoelkopf, Bernhard; 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...

  6. 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.

  7. 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.

  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. 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.

  10. Competing risk model for reduction in life expectancy from radiogenic latent cancer

    International Nuclear Information System (INIS)

    Because of the large number of persons who could potentially receive low doses of radiation as a result of a nuclear reactor accident, the number of fatalities from latent cancers is generally larger than the early, or prompt, fatalities. For this reason the latent cancer fatality risk of reactor accidents is perceived as being more important than the early fatality risk. In addition, there exists the temptation to add the latent cancer fatality risk to the early fatality risk for the purpose of comparing reactor accident risks to other risks that society is exposed to, such as automobile accidents, airplane accidents, hurricanes, etc. However, the impact on the individual, and society as a whole, due to latent cancer fatalities is significantly different from the impact produced by early fatalities. Early fatalities generally result in appreciable life shortening for the affected individual while latent cancer fatalities generally result in very limited life shortening. A mathematical model was developed to express the reduction in life expectancy due to latent radiogenic cancer as a function of dose received

  11. 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.

  12. Manejo clínico odontológico integral del paciente con síndrome de Sjögren: una propuesta

    Directory of Open Access Journals (Sweden)

    G. Sturla Rojas

    2014-08-01

    Full Text Available El síndrome de Sjögren (SS es una enfermedad autoinmune, crónica e inflamatoria caracterizada por infiltración de células plasmáticas y linfocitos en las glándulas exocrinas, particularmente en las salivales y oculares. La patogénesis del SS está relacionada con factores inmunológicos, neurológicos, genéticos, virales y hormonales. La deficiente calidad y cantidad de saliva trae consecuencias devastadoras para la salud dental y bucal, alteraciones del esmalte, caries en las superficies dentarias expuestas, principalmente cervicales, fallas en la adhesión de los materiales obturadores, queratosis en las mucosas, síndrome de boca urente y disconfort en el uso de prótesis dentarias, a pesar de un manejo exhaustivo del medio bucal. Un diagnóstico tardío del SS conlleva a graves consecuencias físicas, sicológicas y económicas en estos pacientes. Su diagnóstico y tratamiento son de gran interés para el odontólogo. La experiencia clínica señala que aquellas piezas dentarias restauradas con prótesis fijas tienen mayor sobrevida y la rehabilitación con prótesis implantosoportadas brindaría un mayor confort para los pacientes. La clínica odontológica debe tener un enfoque integral del daño y la forma de tratamiento debe considerarlos como pacientes de muy alto riesgo de caries basados en CAMBRA (Caries management by risk assesement. El manejo eficaz de la salud oral en estos pacientes comprende la mejora de la producción salival, preservación de mucosas orales y la evaluación periódica del estado bucal. Se propone un protocolo de atención odontológica integral que consta de tres fases: 1 Fase inicial, paliativa y preventiva; 2 Fase restauradora y rehabilitadora, y 3 Fase de mantenimiento.

  13. Tecnolog??as del cuidado del mundo

    OpenAIRE

    Higuera Esp??n, Javier de la

    2011-01-01

    Desde la ??ptica de la ontolog??a de la actualidad, este texto pretende pensar en la posibilidad de unas ???tecnolog??as del mundo??? que, en correlaci??n con las ???tecnolog??as del yo???, sean responsables del cuidado del acontecer singular que define nuestro presente, amenazado por fuertes tendencias homogeneizadoras capaces de cerrar o compactar el mundo. Por el contrario, el mundo s??lo es mundo si ???en ??l puede abrirse un afuera??? (J.-L. Nancy). Para ello analiza la naturaleza de es...

  14. 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.

  15. El Banco del Sur

    OpenAIRE

    Espejo, Silvana

    2012-01-01

    En este trabajo abordaremos las características principales del Banco del Sur como una institución financiera sudamericana. Primero presentaremos sus principales características y explicaremos las características de un banco de desarrollo regional. Luego, expondremos el proceso de conformación del mismo haciendo un recorrido por sus principales antecedentes. Por último, cerraremos con una evaluación sobre el estado actual del Banco del Sur. (Párrafo extraído del texto a modo de resumen)...

  16. 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. PMID:26496914

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. Inducible cyclic AMP early repressor produces reactivation of latent herpes simplex virus type 1 in neurons in vitro.

    Science.gov (United States)

    Colgin, M A; Smith, R L; Wilcox, C L

    2001-03-01

    Herpes simplex virus type 1 (HSV-1) establishes a latent infection in neurons of the peripheral nervous system. During latent HSV-1 infection, viral gene expression is limited to latency-associated transcripts (LAT). HSV-1 remains latent until an unknown mechanism induces reactivation. The ability of the latent virus to periodically reactivate and be shed is essential to the transmission of disease. In vivo, the stimuli that induce reactivation of latent HSV-1 include stress, fever, and UV damage to the skin at the site of initial infection. In vitro, in primary neurons harboring latent HSV-1, nerve growth factor (NGF) deprivation or forskolin treatment induces reactivation. However, the mechanism involved in the induction of reactivation remains poorly understood. An in vitro neuronal model of HSV-1 latency was used to investigate potential mechanisms involved in the induction of reactivation of latent HSV-1. In situ hybridization analysis of neuronal cultures harboring latent HSV-1 showed a marked, rapid decrease in the percentage of LAT-positive neurons following induction of reactivation by NGF deprivation or forskolin treatment. Western blot analysis showed a corresponding increase in expression of the cellular transcription factor inducible cyclic AMP early repressor (ICER) during reactivation. In transient-transfection assays, ICER downregulated LAT promoter activity. Expression of ICER from a recombinant adenoviral vector induced reactivation and decreased the percentage of LAT-positive neurons in neuronal cultures harboring latent HSV-1. These results indicate that ICER represses LAT expression and induces reactivation of latent HSV-1. PMID:11222716

  2. 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

  3. Accesibilidad del sitio web del CONAPRED

    OpenAIRE

    Luján Mora, Sergio

    2012-01-01

    Accesibilidad del sitio web del CONAPRED (Consejo Nacional para Prevenir la Discriminación) de México. Más información: - http://accesibilidadweb.dlsi.ua.es - http://desarrolloweb.dlsi.ua.es Autor: Sergio Luján Mora, profesor de la Universidad de Alicante (http://www.ua.es).

  4. Geologia del Baix Ter

    OpenAIRE

    Mas-Pla, Josep

    1986-01-01

    Article que analitza el valor i la singularitat de les zones humides del Baix Ter, tenint en compte la descripció de les característiques geològiques de la Plana del Ter i dels diferents ambients morfodinàmics que s' hi troben

  5. 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

  6. Latent Dirichlet Allocation Model for Raga Identification of Carnatic Music

    Directory of Open Access Journals (Sweden)

    Rajeswari Sridhar

    2011-01-01

    Full Text Available Problem statement: In this study the Raga of South Indian Carnatic music is determined by constructing a model. Raga is a pre-determined arrangement of notes, which is characterized by an Arohana and Avarohana, which is the ascending and descending arrangement of notes and Raga lakshana. Approach: In this study a Latent Dirichlet Allocation (LDA model is constructed to identify the Raga of South Indian Carnatic music. LDA is an unsupervised statistical approach which is being used for document classification to determine the underlying topics in a given document. The construction of LDA is based on the assumption that the notes of a given music piece can be mapped to the words in a topic and the topics in a document can be mapped to the Raga. The identification of notes is very difficult due to the narrow range of frequency and the characteristics of Carnatic music. This inclined us in moving to a probabilistic approach for the identification of Raga. In this study we identify the notes of a given signal and using these notes and Raga lakshana, a probabilistic model in terms of LDA's parameters ∝ and θ are computed and constructed for every Raga by initially assuming a value which is constant for every Raga. This value of ∝ is cultured after determining θ for a given Raga. The θ of a given Raga is computed using the characteristic phrases which is a sequence of notes and is unique for a given Raga. During the Raga identification phase, the value of ∝ and θ are computed and is matched with the constructed LDA model to identify the given Raga. Results: Using this model, the Raga identification of Parent Ragas had a lower error rate than that of Child Raga. For parent Raga an average identification rate of 75% was achieved. Conclusion/Recommendations: The accuracy of the algorithm can be improved by using more features of Raga lakshana. After identifying the Raga, it can be used as features to be used by a Music Information Retrieval

  7. Del territorio del sujeto al emplazamiento del Común

    Directory of Open Access Journals (Sweden)

    Mariano Adrían Ferretti

    2016-01-01

    Full Text Available La construcción de lo público abarca una variedad de dinámicas que condicionan el resultado físico de los espacios donde actúan los individuos en sus necesidades de habitar, modificando su realidad desde la diferenciación y la singularización subjetiva del entorno que derivan en nuevas formas de territorialidad de lo público a partir de la dialéctica entre lo público y lo privado. Sin embargo, los resultados de tales representaciones entendidas como acciones colectivas –y por tanto comunes- no siempre explican los valores que desde lo simbólico partiendo del sujeto constituyan un estatus diferente de lo público en los procesos de territorialización. Se propone una aproximación que aborde de manera teórica cuestiones tales como: los vínculos del individuo con los procesos de acumulación material y transformación del territorio y las implicaciones que dichos fenómenos tienen en la posibilidad de constitución de un sujeto que trascendiendo al individuo sea capaz de conformar un nuevo estatus del sujeto o, dicho de otro modo, un emplazamiento del Común.

  8. 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

  9. 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.

  10. Large-scale weakly supervised object localization via latent category learning.

    Science.gov (United States)

    Chong Wang; Kaiqi Huang; Weiqiang Ren; Junge Zhang; Maybank, Steve

    2015-04-01

    Localizing objects in cluttered backgrounds is challenging under large-scale weakly supervised conditions. Due to the cluttered image condition, objects usually have large ambiguity with backgrounds. Besides, there is also a lack of effective algorithm for large-scale weakly supervised localization in cluttered backgrounds. However, backgrounds contain useful latent information, e.g., the sky in the aeroplane class. If this latent information can be learned, object-background ambiguity can be largely reduced and background can be suppressed effectively. In this paper, we propose the latent category learning (LCL) in large-scale cluttered conditions. LCL is an unsupervised learning method which requires only image-level class labels. First, we use the latent semantic analysis with semantic object representation to learn the latent categories, which represent objects, object parts or backgrounds. Second, to determine which category contains the target object, we propose a category selection strategy by evaluating each category's discrimination. Finally, we propose the online LCL for use in large-scale conditions. Evaluation on the challenging PASCAL Visual Object Class (VOC) 2007 and the large-scale imagenet large-scale visual recognition challenge 2013 detection data sets shows that the method can improve the annotation precision by 10% over previous methods. More importantly, we achieve the detection precision which outperforms previous results by a large margin and can be competitive to the supervised deformable part model 5.0 baseline on both data sets. PMID:25643405

  11. 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.

  12. [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.

  13. Climate forcing and response to idealized changes in surface latent and sensible heat

    International Nuclear Information System (INIS)

    Land use and land cover changes affect the partitioning of latent and sensible heat, which impacts the broader climate system. Increased latent heat flux to the atmosphere has a local cooling influence known as 'evaporative cooling', but this energy will be released back to the atmosphere wherever the water condenses. However, the extent to which local evaporative cooling provides a global cooling influence has not been well characterized. Here, we perform a highly idealized set of climate model simulations aimed at understanding the effects that changes in the balance between surface sensible and latent heating have on the global climate system. We find that globally adding a uniform 1 W m-2 source of latent heat flux along with a uniform 1 W m-2 sink of sensible heat leads to a decrease in global mean surface air temperature of 0.54 ± 0.04 K. This occurs largely as a consequence of planetary albedo increases associated with an increase in low elevation cloudiness caused by increased evaporation. Thus, our model results indicate that, on average, when latent heating replaces sensible heating, global, and not merely local, surface temperatures decrease.

  14. Latent risk and trend models for the evolution of annual fatality numbers in 30 European countries.

    Science.gov (United States)

    Dupont, Emmanuelle; Commandeur, Jacques J F; Lassarre, Sylvain; Bijleveld, Frits; Martensen, Heike; Antoniou, Constantinos; Papadimitriou, Eleonora; Yannis, George; Hermans, Elke; Pérez, Katherine; Santamariña-Rubio, Elena; Usami, Davide Shingo; Giustiniani, Gabriele

    2014-10-01

    In this paper a unified methodology is presented for the modelling of the evolution of road safety in 30 European countries. For each country, annual data of the best available exposure indicator and of the number of fatalities were simultaneously analysed with the bivariate latent risk time series model. This model is based on the assumption that the amount of exposure and the number of fatalities are intrinsically related. It captures the dynamic evolution in the fatalities as the product of the dynamic evolution in two latent trends: the trend in the fatality risk and the trend in the exposure to that risk. Before applying the latent risk model to the different countries it was first investigated and tested whether the exposure indicator at hand and the fatalities in each country were in fact related at all. If they were, the latent risk model was applied to that country; if not, a univariate local linear trend model was applied to the fatalities series only, unless the latent risk time series model was found to yield better forecasts than the univariate local linear trend model. In either case, the temporal structure of the unobserved components of the optimal model was established, and structural breaks in the trends related to external events were identified and captured by adding intervention variables to the appropriate components of the model. As a final step, for each country the optimally modelled developments were projected into the future, thus yielding forecasts for the number of fatalities up to and including 2020. PMID:25000194

  15. Biodiversidad del margen continental del Caribe colombiano.

    OpenAIRE

    2010-01-01

    Incluye valiosa información producto de varios años de investigación marina de las aguas profundas, la plataforma continental y el talud superior del Caribe colombiano, llevada a cabo por un grupo multidisciplinario de investigadores en áreas de taxonomía, geología, ecología, cartografía y conservación del Invemar. Dentro de los resultados más destacados se encuentra el haber colectado e identificado más de 1600 especies, de las cuales alrededor del 35% se constituyeron en primeros registr...

  16. Interlocking directorates in Irish companies using a latent space model for bipartite networks.

    Science.gov (United States)

    Friel, Nial; Rastelli, Riccardo; Wyse, Jason; Raftery, Adrian E

    2016-06-14

    We analyze the temporal bipartite network of the leading Irish companies and their directors from 2003 to 2013, encompassing the end of the Celtic Tiger boom and the ensuing financial crisis in 2008. We focus on the evolution of company interlocks, whereby a company director simultaneously sits on two or more boards. We develop a statistical model for this dataset by embedding the positions of companies and directors in a latent space. The temporal evolution of the network is modeled through three levels of Markovian dependence: one on the model parameters, one on the companies' latent positions, and one on the edges themselves. The model is estimated using Bayesian inference. Our analysis reveals that the level of interlocking, as measured by a contraction of the latent space, increased before and during the crisis, reaching a peak in 2009, and has generally stabilized since then. PMID:27247395

  17. 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.

  18. Low incidence of Peach latent mosaic viroid in peach mother blocks in Serbia

    Directory of Open Access Journals (Sweden)

    Darko Jevremović

    2014-06-01

    Full Text Available Peach latent mosaic viroid (PLMVd is the causal agent of peach latent mosaic disease that is common on peaches and nectarines worldwide. Most of the isolates do not cause any symptoms on the foliage and the disease may be latent for years. A survey to investigate the presence of PLMVd in selected peach mother blocks in 9 Serbian districts was carried out in 2011 through 2013. A total of 315 trees/samples originating from 43 mother blocks, representing 35 peach and nectarine varieties and 2 rootstocks, were tested by Reverse Transcription - Polymerase Chain Reaction (RT-PCR. PLMVd was detected in 13 samples (4.13% belonging to 7 varieties and one vineyard peach rootstock. Infected samples were found in 7 mother blocks from 3 districts. Our results indicated a low incidence of PLMVd in the analyzed peach mother blocks.

  19. 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.

  20. 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.

  1. 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.

  2. Automatic sleep classification using a data-driven topic model reveals latent sleep states

    DEFF Research Database (Denmark)

    Koch, Henriette; Christensen, Julie Anja Engelhard; Frandsen, Rune;

    2014-01-01

    Latent Dirichlet Allocation. Model application was tested on control subjects and patients with periodic leg movements (PLM) representing a non-neurodegenerative group, and patients with idiopathic REM sleep behavior disorder (iRBD) and Parkinson's Disease (PD) representing a neurodegenerative group......Background: The golden standard for sleep classification uses manual scoring of polysomnography despite points of criticism such as oversimplification, low inter-rater reliability and the standard being designed on young and healthy subjects. New method: To meet the criticism and reveal the latent...... sleep states, this study developed a general and automatic sleep classifier using a data-driven approach. Spectral EEG and EOG measures and eye correlation in 1 s windows were calculated and each sleep epoch was expressed as a mixture of probabilities of latent sleep states by using the topic model...

  3. Failure of PCR to Detect Treponema pallidum ssp. pertenue DNA in Blood in Latent Yaws.

    Directory of Open Access Journals (Sweden)

    Michael Marks

    Full Text Available Yaws, caused by Treponema pallidum ssp. pertenue, is a neglected tropical disease closely related to venereal syphilis and is targeted for eradication by 2020. Latent yaws represents a diagnostic challenge, and current tools cannot adequately distinguish between individuals with true latent infection and individuals who are serofast following successful treatment. PCR on blood has previously been shown to detect T. pallidum DNA in patients with syphilis, suggesting that this approach may be of value in yaws. We performed real-time PCR for Treponema pallidum ssp. pertenue on blood samples from 140 children with positive T. pallidum Particle Agglutination (TPPA and Rapid Plasma Reagin (RPR tests and 7 controls (negative serology, all collected as part of a prospective study of yaws in the Solomon Islands. All samples were also tested by a nested PCR for T. pallidum. 12 patients had clinical evidence of active yaws whilst 128 were considered to have latent yaws. 43 children had high titre rapid plasma reagins (RPRs of ≥1:32. PCR testing with both assays gave negative results in all cases. It is possible that the failure to detect T. pallidum ssp. pertenue in blood reflects lower loads of organism in latent yaws compared to those in latent infection with T. pallidum ssp. pertenue, and/or a lower propensity for haematogenous dissemination in yaws than in syphilis. As the goal of the yaws control programme is eradication, a tool that can differentiate true latent infection from individuals who are serofast would be of value; however, PCR of blood is not that tool.

  4. Failure of PCR to Detect Treponema pallidum ssp. pertenue DNA in Blood in Latent Yaws.

    Science.gov (United States)

    Marks, Michael; Katz, Samantha; Chi, Kai-Hua; Vahi, Ventis; Sun, Yongcheng; Mabey, David C; Solomon, Anthony W; Chen, Cheng Y; Pillay, Allan

    2015-01-01

    Yaws, caused by Treponema pallidum ssp. pertenue, is a neglected tropical disease closely related to venereal syphilis and is targeted for eradication by 2020. Latent yaws represents a diagnostic challenge, and current tools cannot adequately distinguish between individuals with true latent infection and individuals who are serofast following successful treatment. PCR on blood has previously been shown to detect T. pallidum DNA in patients with syphilis, suggesting that this approach may be of value in yaws. We performed real-time PCR for Treponema pallidum ssp. pertenue on blood samples from 140 children with positive T. pallidum Particle Agglutination (TPPA) and Rapid Plasma Reagin (RPR) tests and 7 controls (negative serology), all collected as part of a prospective study of yaws in the Solomon Islands. All samples were also tested by a nested PCR for T. pallidum. 12 patients had clinical evidence of active yaws whilst 128 were considered to have latent yaws. 43 children had high titre rapid plasma reagins (RPRs) of ≥1:32. PCR testing with both assays gave negative results in all cases. It is possible that the failure to detect T. pallidum ssp. pertenue in blood reflects lower loads of organism in latent yaws compared to those in latent infection with T. pallidum ssp. pertenue, and/or a lower propensity for haematogenous dissemination in yaws than in syphilis. As the goal of the yaws control programme is eradication, a tool that can differentiate true latent infection from individuals who are serofast would be of value; however, PCR of blood is not that tool. PMID:26125585

  5. Inspection technique of latent flaws on fine polished glass substrates using stress-induced light scattering method

    Science.gov (United States)

    Sakata, Yoshitaro; Sakai, Kazufumi; Nonaka, Kazuhiro

    2014-05-01

    The fine polishing technique, e.g. Chemical Mechanical Polishing treatment (CMP), is one of the most important techniques in the glass substrate manufacturing. However, mechanical interaction, e.g. friction, occurs between the abrasive and the surface of substrates. Therefore, latent flaws are formed in the surfaces of glass substrates depending on the polishing condition. In the case of the cleaning process of the glass substrate in which the latent flaws existed, latent flaws become obvious because glass surfaces were eaten away by chemical interaction of cleaning liquid. Therefore, latent flaws are the cause of decrease the yield of products. In general, non-destructive inspection techniques, e.g. light scattering method, foreign matter on the surface of glass substrates. Though, it is difficult to detect the latent flaws by these method, because these are closed. The present authors propose a novel inspection technique of latent flaws which occurred by the fine polishing technique, using light scattering method with stress concentration (Stress-Induced Light scattering Method; SILSM). SILSM is possible to classify and separately detect latent flaws and particles on the surfaces. Samples are deformed by the actuator and stress concentrations are occurred around the tip of latent flaws. By photo-elastic effect, the refractive index of around the tip of latent flaws is changed. And then, changed refractive index is detected by cooled CCD camera as the light scattering intensity. In this report, applying SILSM to glass substrates, latent flaws on the surface of glass substrates are detected non-destructively, and the usefulness of SILSM is evaluated as novel inspection technique of latent flaws.

  6. Efficient reactivation of latent herpes simplex virus from mouse central nervous system tissues.

    Science.gov (United States)

    Chen, Shih-Heng; Yao, Hui-Wen; Huang, Wen-Yen; Hsu, Kuei-Sen; Lei, Huan-Yao; Shiau, Ai-Li; Chen, Shun-Hua

    2006-12-01

    For decades, numerous ex vivo studies have documented that latent herpes simplex virus (HSV) reactivates efficiently from ganglia, but rarely from the central nervous systems (CNS), of mice when assayed by mincing tissues before explant culture, despite the presence of viral genomes in both sites. Here we show that 88% of mouse brain stems reactivated latent virus when they were dissociated into cell suspensions before ex vivo explant culture. The efficient reactivation of HSV from the mouse CNS was demonstrated with more than one viral strain, viral serotype, and mouse strain, further indicating that the CNS can be an authentic latency site for HSV with the potential to cause recurrent disease. PMID:17005636

  7. Lanthanide mixed ligand chelates for DNA profiling and latent fingerprint detection

    Science.gov (United States)

    Menzel, E. R.; Allred, Clay

    1997-02-01

    It is our aim to develop a universally applicable latent fingerprint detection method using lanthanide (rare-earth) complexes as a source of luminescence. Use of these lanthanide complexes offers advantages on several fronts, including benefits from large Stokes shifts, long luminescence lifetimes, narrow emissions, ability of sequential assembly of complexes, and chemical variability of the ligands. Proper exploitation of these advantages would lead to a latent fingerprint detection method superior to any currently available. These same characteristics also lend themselves to many of the problems associated with DNA processing in the forensic science context.

  8. Analysis of counts with two latent classes, with application to risk assessment using physician visit records

    OpenAIRE

    Wang, Huijing

    2012-01-01

    Motivated by the CAYACS program at BC Cancer Research Center, this thesis project introduces a latent class model to formulate event counts. In particular, we consider a pop- ulation with two latent classes, such as an at-risk group and a not-at-risk group of cancer survivors in the CAYACS program. Likelihood-based inference procedures are proposed for estimating the model parameters with or without one class fully specified. The EM algo- rithm is adapted to compute the MLE; a pseudo MLE of t...

  9. Cyclist–motorist crash patterns in Denmark: A latent class clustering approach

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2013-01-01

    differentiating the latent classes were speed limit, infrastructure type, road surface conditions, number of lanes, motorized vehicle precrash maneuvers, the availability of a cycle lane, cyclist intoxication, and helmet wearing behavior. After the latent class clustering, the distribution of cyclists’ injury......Objective: The current study aimed at uncovering patterns of cyclist–motorist crashes in Denmark and investigating their prevalence and severity. The importance of implementing clustering techniques for providing a holistic overview of vulnerable road users’ crash patterns derives from the need...

  10. Facies del subfondo del canal Beagle, Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    Gustavo Bujalesky

    2004-03-01

    Full Text Available El canal Beagle conecta los océanos Pacífico y Atlántico en el extremo meridional de Sudamérica y se ubica en el ambiente subantártico. Conforma una cuenca de unos 300 m de profundidad máxima y está separada del océano Atlántico por un umbral de 30 m de profundidad. El canal es un valle tectónico que fue completamente cubierto por el hielo glacial durante la última glaciación. Posteriormente, el canal fue ocupado por un lago glacial desde los 12.000 a los 8.000 años A.P., cuando fue invadido por el mar que alcanzó un nivel máximo entre los 6.000 y 5.000 años A.P. Con el objetivo de analizar las facies sedimentarias superficiales y del subfondo del canal se realizó un relevamiento geofísico con sonar de barrido lateral y un perfilador de 3,5 kHz. Sobre un basamento constituido por rocas metamórficas del Mesozoico, se identificaron depósitos de till y secuencias granodecrecientes que representan distintos estadios del retroceso glaciar, evidenciando hacia la sección superior facies lacustres y por encima depósitos de la transgresión marina del Holoceno. Además, se han identificado paleocauces y secuencias fluviales cubiertas por sedimentos marinos transgresivos.

  11. Estudio del proceso de crecimiento del cultivo del tomate

    OpenAIRE

    Barraza, Fernando V.; Fischer, Gerhard; Cardona, Carlos E.

    2010-01-01

    Para conocer la densidad poblacional óptimay obtener el mayor rendimiento en el cultivo deltomate en el Valle del Sinú medio, se hizo una investigaciónmediante diseño completamente al azar con cuatrotratamientos (densidades poblacionales de 20.000,25.000, 33.333 y 50.000 plantas∙ha -1) y tres repeticiones.Se tomaron las medidas directas: altura de planta, númerode hojas, área foliar, número de frutos y rendimiento.También se calcularon los índices de crecimiento: tasa decrecimiento del cultiv...

  12. Psicodrama del duelo.

    Directory of Open Access Journals (Sweden)

    José Antonio Espina Barrio

    1997-01-01

    Full Text Available La pérdida de rituales agrava y alarga la reacción del duelo. Se define el Psicodrama Antropológico y su intervención en el proceso del duelo. El Psicodrama Focal del Duelo es una psicoterapia breve centrada en el proceso de Duelo. Se comentan varios casos y resultados. Se concluye con un programa sencillo para el duelo en Atención Primaria.

  13. Automatic hyperspectral camera for latent fingerprint detection and contrast enhancement. Final report, September 2, 1998 - March 17, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Paul Shnitser

    1999-06-01

    Physical Optics Corporation demonstrated the feasibility of the contrast enhancement of the latent fingerprint by portable hyperspectral imaging camera. The demonstrated non-contact technology is applicable for observation of the low contrast laser excited fluorescence from latent fingerprints as well as for the contrast enhancement of chemically processed fingerprints. Experiments were conducted with fingerprints on various types of substrates.

  14. The Latent Structure of Dietary Restraint, Body Dissatisfaction, and Drive for Thinness: A Series of Taxometric Analyses

    Science.gov (United States)

    Holm-Denoma, Jill M.; Richey, J. Anthony; Joiner, Thomas E., Jr.

    2010-01-01

    Although the latent structure of various eating disorders has been explored in previous studies, no published studies have examined the latent structure of theoretically relevant variables that have been shown to cut across eating disorder diagnoses. The current study examined 3 such variables (dietary restraint, body dissatisfaction, and drive…

  15. Sensitivity of model parameterizations for simulated latent heat flux at the snow surface for complex mountain sites

    Science.gov (United States)

    The snowcover energy balance is typically dominated by net radiation and sensible and latent heat fluxes. Validation of the two latter components is rare and often difficult to undertake at complex mountain sites. Latent heat flux, the focus of this paper, is the primary coupling mechanism between...

  16. Indentifying Latent Classes and Testing Their Determinants in Early Adolescents' Use of Computers and Internet for Learning

    Science.gov (United States)

    Heo, Gyun

    2013-01-01

    The purpose of the present study was to identify latent classes resting on early adolescents' change trajectory patterns in using computers and the Internet for learning and to test the effects of gender, self-control, self-esteem, and game use in South Korea. Latent growth mixture modeling (LGMM) was used to identify subpopulations in the Korea…

  17. No sex diference in contextual control over the expression of latent inhibition and extinction in pavlovian fear conditioning in rats

    NARCIS (Netherlands)

    Maes, J.H.R.

    2002-01-01

    Three experiments with Wistar rats searched for a sex difference in contextual control over the expression of latent inhibition and extinction. Experiment 1 used a latent inhibition procedure; Experiments 2 and 3 employed an extinction preparation. All experiments used a shock as the unconditioned s

  18. Rasch Model Parameter Estimation in the Presence of a Nonnormal Latent Trait Using a Nonparametric Bayesian Approach

    Science.gov (United States)

    Finch, Holmes; Edwards, Julianne M.

    2016-01-01

    Standard approaches for estimating item response theory (IRT) model parameters generally work under the assumption that the latent trait being measured by a set of items follows the normal distribution. Estimation of IRT parameters in the presence of nonnormal latent traits has been shown to generate biased person and item parameter estimates. A…

  19. Developmental Relations between Reading and Writing at the Word, Sentence, and Text Levels: A Latent Change Score Analysis

    Science.gov (United States)

    Ahmed, Yusra; Wagner, Richard K.; Lopez, Danielle

    2014-01-01

    Relations between reading and writing have been studied extensively, but the less is known about the developmental nature of their interrelations. This study applied latent change score modeling to investigate longitudinal relations between reading and writing skills at the word, sentence, and text levels. Latent change score models were used to…

  20. Satisfacción de programas sociales. El caso del programa de abasto de leche Liconsa

    Directory of Open Access Journals (Sweden)

    Adolfo Cogco

    2013-12-01

    Full Text Available El programa Abasto Social de Leche, que otorga esta bebida de manera subsidiada a personas enestado de pobreza, es uno de los más antiguos en México. El producto ha pasado por diversosmejoramientos de corte nutricional y de imagen; en este el artículo se presentarán los hallazgos sobrela satisfacción que tienen los beneficiarios del programa, a través del uso de una metodologíaintegral que abarca la gestión del mismo, la perspectiva de los beneficiarios en diversos ámbitosy el aspecto comunitario. Los resultados, obtenidos por medio de un modelo de ecuaciones estructuralescon variables latentes, señalan que la población objetivo se encuentra satisfecha con el programa.

  1. Fractura triple del complejo suspensorio del hombro

    Directory of Open Access Journals (Sweden)

    Eraclio Delgado Rifá

    2015-06-01

    Full Text Available El complejo suspensorio del hombro es una estructura sumamente importante, compuesta por un anillo de huesos y tejidos blandos. Las lesiones aisladas de este complejo anatómico son frecuentes y no afectan su estabilidad. La interrupción doble conduce a la inestabilidad de esta estructura y usualmente requiere tratamiento quirúrgico. La triple interrupción, por su parte, es sumamente rara y es encontrada en casos de trauma de alta energía a menudo en asociación con otras lesiones. Se presenta una triple lesión del complejo suspensorio del hombro en un paciente de 46 años de edad, con una fractura de la glenoides, del acromion tipo III de Kuhn y de la coracoides tipo II de Ogawa. En este caso, la fractura del acromion fue tratada con fijación percutánea con alambres de Kirschner, por tener asociado lesiones de partes blandas que contraindicaron la reducción abierta. La fractura de la glenoides y de la apófisis coracoides fueron tratadas conservadoramente. Después de 6 meses de evolución, el paciente tuvo un resultado funcional aceptable, con una abducción de 90 grados, los 30 grados de rotación externa y 70 de rotación interna, además asintomático y consolidación de todas las fracturas. A pesar de ser catalogada de una lesión grave del cinturón escapular y estar asociada a otras lesiones se obtuvo un resultado satisfactorio al final del tratamiento.

  2. Marketing Mix del Software.

    OpenAIRE

    Yudith del Carmen Rodríguez Pérez

    2006-01-01

    La ingeniería del software y los modelos de calidad del software han consolidado sus esfuerzos en el proceso de producción del mismo, sin embargo son pocos sus aportes en el proceso de comercialización. Es esencial en la ciencia de la computación desarrollar un modelo de comercialización para las organizaciones productoras de software con el fin de elevar la productividad de las mismas. Sin embargo, es preciso primero conocer las características del producto software que los diferencian de ot...

  3. Estudio del léxico del Ecuador

    OpenAIRE

    Estrella Santos, Ana Teresa

    2008-01-01

    El presente trabajo de investigación pretende proporcionar una descripción del léxico del español del Ecuador, a partir de materiales de la lengua hablada. Hemos llevado a cabo un análisis contrastivo del léxico de las provincias de Pichincha y Guayas, una recopilación del léxico general del Ecuador y un análisis de los quichuismos presentes en nuestro corpus.

  4. LA POLITICA SOCIAL DEL "GOBIERNO DEL CAMBIO"

    Directory of Open Access Journals (Sweden)

    Laura Mota Díaz

    2002-01-01

    Full Text Available El artículo se centra en la política social del actual sexenio foxista , la cual se ha definido como incluyente y equitativa dentro del marco de un gobierno autodenominado del cambio, no sólo por lo que se refiere a la alternancia política del poder, sino porque además pretende ser un gobierno con una visión más amplia del desarrollo. Todo ello se traduce en “nuevas” estrategias para alcanzar la democracia, la equidad, la justicia social y el bienestar general de la población. El objetivo es analizar las posibilidades y limitaciones de un verdadero cambio que contribuya a mejorar la calidad de vida de la población en su sentido más amplio, pues los retos son cada vez mayores dado el incremento en los niveles de pobreza, el creciente desempleo y la constante violación a los derechos humanos.

  5. Further Examining Berry's Model: The Applicability of Latent Profile Analysis to Acculturation

    Science.gov (United States)

    Fox, Rina S.; Merz, Erin L.; Solórzano, Martha T.; Roesch, Scott C.

    2013-01-01

    This study used latent profile analysis (LPA) to identify acculturation profiles. A three-profile solution fit the data best, and comparisons on demographic and psychosocial outcomes as a function of profile yielded expected results. The findings support using LPA as a parsimonious way to model acculturation without anticipating profiles in…

  6. Estimating and Visualizing Nonlinear Relations among Latent Variables: A Semiparametric Approach

    Science.gov (United States)

    Pek, Jolynn; Sterba, Sonya K.; Kok, Bethany E.; Bauer, Daniel J.

    2009-01-01

    The graphical presentation of any scientific finding enhances its description, interpretation, and evaluation. Research involving latent variables is no exception, especially when potential nonlinear effects are suspect. This article has multiple aims. First, it provides a nontechnical overview of a semiparametric approach to modeling nonlinear…

  7. Intraclass Correlation Coefficients in Hierarchical Designs: Evaluation Using Latent Variable Modeling

    Science.gov (United States)

    Raykov, Tenko

    2011-01-01

    Interval estimation of intraclass correlation coefficients in hierarchical designs is discussed within a latent variable modeling framework. A method accomplishing this aim is outlined, which is applicable in two-level studies where participants (or generally lower-order units) are clustered within higher-order units. The procedure can also be…

  8. Modeling change in learning strategies throughout higher education: a multi-indicator latent growth perspective.

    Directory of Open Access Journals (Sweden)

    Liesje Coertjens

    Full Text Available The change in learning strategies during higher education is an important topic of research in the Student Approaches to Learning field. Although the studies on this topic are increasingly longitudinal, analyses have continued to rely primarily on traditional statistical methods. The present research is innovative in the way it uses a multi-indicator latent growth analysis in order to more accurately estimate the general and differential development in learning strategy scales. Moreover, the predictive strength of the latent growth models are estimated. The sample consists of one cohort of Flemish University College students, 245 of whom participated in the three measurement waves by filling out the processing and regulation strategies scales of the Inventory of Learning Styles--Short Versions. Independent-samples t-tests revealed that the longitudinal group is a non-random subset of students starting University College. For each scale, a multi-indicator latent growth model is estimated using Mplus 6.1. Results suggest that, on average, during higher education, students persisting in their studies in a non-delayed manner seem to shift towards high-quality learning and away from undirected and surface-oriented learning. Moreover, students from the longitudinal group are found to vary in their initial levels, while, unexpectedly, not in their change over time. Although the growth models fit the data well, significant residual variances in the latent factors remain.

  9. Modeling change in learning strategies throughout higher education: a multi-indicator latent growth perspective.

    Science.gov (United States)

    Coertjens, Liesje; Donche, Vincent; De Maeyer, Sven; Vanthournout, Gert; Van Petegem, Peter

    2013-01-01

    The change in learning strategies during higher education is an important topic of research in the Student Approaches to Learning field. Although the studies on this topic are increasingly longitudinal, analyses have continued to rely primarily on traditional statistical methods. The present research is innovative in the way it uses a multi-indicator latent growth analysis in order to more accurately estimate the general and differential development in learning strategy scales. Moreover, the predictive strength of the latent growth models are estimated. The sample consists of one cohort of Flemish University College students, 245 of whom participated in the three measurement waves by filling out the processing and regulation strategies scales of the Inventory of Learning Styles--Short Versions. Independent-samples t-tests revealed that the longitudinal group is a non-random subset of students starting University College. For each scale, a multi-indicator latent growth model is estimated using Mplus 6.1. Results suggest that, on average, during higher education, students persisting in their studies in a non-delayed manner seem to shift towards high-quality learning and away from undirected and surface-oriented learning. Moreover, students from the longitudinal group are found to vary in their initial levels, while, unexpectedly, not in their change over time. Although the growth models fit the data well, significant residual variances in the latent factors remain.

  10. On Fitting Nonlinear Latent Curve Models to Multiple Variables Measured Longitudinally

    Science.gov (United States)

    Blozis, Shelley A.

    2007-01-01

    This article shows how nonlinear latent curve models may be fitted for simultaneous analysis of multiple variables measured longitudinally using Mx statistical software. Longitudinal studies often involve observation of several variables across time with interest in the associations between change characteristics of different variables measured…

  11. Latent vs. Observed Variables : Analysis of Irrigation Water Efficiency Using SEM and SUR

    NARCIS (Netherlands)

    Tang, Jianjun; Folmer, Henk

    2016-01-01

    In this paper we compare conceptualising single factor technical and allocative efficiency as indicators of a single latent variable, or as separate observed variables. In the former case, the impacts on both efficiency types are analysed by means of structural equationmodeling (SEM), in the latter

  12. A Latent Consolidation Phase in Auditory Identification Learning: Time in the Awake State Is Sufficient

    Science.gov (United States)

    Roth, Daphne Ari-Even; Kishon-Rabin, Liat; Hildesheimer, Minka; Karni, Avi

    2005-01-01

    Large gains in performance, evolving hours after practice has terminated, were reported in a number of visual and some motor learning tasks, as well as recently in an auditory nonverbal discrimination task. It was proposed that these gains reflect a latent phase of experience-triggered memory consolidation in human skill learning. It is not clear,…

  13. Latent hepatitis B is a risk factor for hepatocellular carcinoma in patients with chronic hepatitis C

    OpenAIRE

    Reddy, Arvind; May, Elizabeth; Ehrinpreis, Murray; Mutchnick, Milton

    2013-01-01

    AIM: To study the potential association between hepatocellular carcinoma (HCC) in patients with chronic hepatitis C (CHC), cirrhosis and latent hepatitis B (LHB) infection, defined as the absence of detectable serum hepatitis B surface antigen (HBsAg) and the presence of hepatitis B core antibody (HBcAb).

  14. An Evaluation of Latent Growth Models for Propensity Score Matched Groups

    Science.gov (United States)

    Leite, Walter L.; Sandbach, Robert; Jin, Rong; MacInnes, Jann W.; Jackman, M. Grace-Anne

    2012-01-01

    Because random assignment is not possible in observational studies, estimates of treatment effects might be biased due to selection on observable and unobservable variables. To strengthen causal inference in longitudinal observational studies of multiple treatments, we present 4 latent growth models for propensity score matched groups, and…

  15. Latent Inhibition Is Affected by Phase of Estrous Cycle in Female Rats

    Science.gov (United States)

    Quinlan, Matthew G.; Duncan, Andrew; Loiselle, Catherine; Graffe, Nicole; Brake, Wayne G.

    2010-01-01

    Estrogen has been shown to have a strong modulatory influence on several types of cognition in both women and female rodents. Latent inhibition is a task in which pre-exposure to a neutral stimulus, such as a tone, later impedes the association of that stimulus with a particular consequence, such as a shock. Previous work from our lab demonstrates…

  16. Histone deacetylase inhibitors for purging HIV-1 from the latent reservoir.

    NARCIS (Netherlands)

    Matalon, S.; Rasmussen, T.A.; Dinarello, C.A.

    2011-01-01

    A reservoir of latently infected memory CD4(+) T cells is believed to be the source of HIV-1 reemergence after discontinuation of antiretroviral therapy. HIV-1 eradication may depend on depletion of this reservoir. Integrated HIV-1 is inaccessible for expression, in part because of histone deacetyla

  17. Exploring the Relationship between Autism Spectrum Disorder and Epilepsy Using Latent Class Cluster Analysis

    Science.gov (United States)

    Cuccaro, Michael L.; Tuchman, Roberto F.; Hamilton, Kara L.; Wright, Harry H.; Abramson, Ruth K.; Haines, Jonathan L.; Gilbert, John R.; Pericak-Vance, Margaret

    2012-01-01

    Epilepsy co-occurs frequently in autism spectrum disorders (ASD). Understanding this co-occurrence requires a better understanding of the ASD-epilepsy phenotype (or phenotypes). To address this, we conducted latent class cluster analysis (LCCA) on an ASD dataset (N = 577) which included 64 individuals with epilepsy. We identified a 5-cluster…

  18. Selecting antagonists for control of postharvest brown rot of stone fruits originating from latent infections

    Science.gov (United States)

    In contrast to biological control of postharvest decays (BCPD) of fruits originating from wound infections after harvest, BCPD originating from latent infections occurring in the orchard has not been developed. This is largely due to the lack of methodology to screen and evaluate microbes for bioco...

  19. Determination of Urinary Neopterin/Creatinine Ratio to Distinguish Active Tuberculosis from Latent Mycobacterium tuberculosis Infection

    Directory of Open Access Journals (Sweden)

    Michael Eisenhut

    2016-01-01

    Full Text Available Background. Biomarkers to distinguish latent from active Mycobacterium (M. tuberculosis infection in clinical practice are lacking. The urinary neopterin/creatinine ratio can quantify the systemic interferon-gamma effect in patients with M. tuberculosis infection. Methods. In a prospective observational study, urinary neopterin levels were measured by enzyme linked immunosorbent assay in patients with active tuberculosis, in people with latent M. tuberculosis infection, and in healthy controls and the urinary neopterin/creatinine ratio was calculated. Results. We included a total of 44 patients with M. tuberculosis infection and nine controls. 12 patients had active tuberculosis (8 of them culture-confirmed. The median age was 15 years (range 4.5 to 49. Median urinary neopterin/creatinine ratio in patients with active tuberculosis was 374.1 micromol/mol (129.0 to 1072.3, in patients with latent M. tuberculosis infection it was 142.1 (28.0 to 384.1, and in controls it was 146.0 (40.3 to 200.0, with significantly higher levels in patients with active tuberculosis (p<0.01. The receiver operating characteristics curve had an area under the curve of 0.84 (95% CI 0.70 to 0.97 (p<0.01. Conclusions. Urinary neopterin/creatinine ratios are significantly higher in patients with active tuberculosis compared to patients with latent infection and may be a significant predictor of active tuberculosis in patients with M. tuberculosis infection.

  20. A Latent Growth Curve Analysis of Reading Achievement for an At-Risk Population

    Science.gov (United States)

    Beecher, Constance C.

    2011-01-01

    The development of reading skills from age seven until age 19 was investigated for children who were referred for special education preschool intervention using latent growth curve analysis (n=206). Approximately one-third of the study sample did not require special education services after preschool, providing a natural comparison group. Reading…

  1. Accuracy of Estimates and Statistical Power for Testing Meditation in Latent Growth Curve Modeling

    Science.gov (United States)

    Cheong, JeeWon

    2011-01-01

    The latent growth curve modeling (LGCM) approach has been increasingly utilized to investigate longitudinal mediation. However, little is known about the accuracy of the estimates and statistical power when mediation is evaluated in the LGCM framework. A simulation study was conducted to address these issues under various conditions including…

  2. Aptitude-Treatment Interaction Effects on Explicit Rule Learning: A Latent Growth Curve Analysis

    Science.gov (United States)

    Hwu, Fenfang; Pan, Wei; Sun, Shuyan

    2014-01-01

    Finding the match between individuals and educational treatments is the aim of both educators and the aptitude-treatment interaction research paradigm. Using the latent growth curve analysis, the present study investigates the interaction between the type of explicit instructional approaches (deductive vs. explicit-inductive) and the level of…

  3. Parent Involvement and Science Achievement: A Cross-Classified Multilevel Latent Growth Curve Analysis

    Science.gov (United States)

    Johnson, Ursula Y.; Hull, Darrell M.

    2014-01-01

    The authors examined science achievement growth at Grades 3, 5, and 8 and parent school involvement at the same time points using the Early Childhood Longitudinal Study-Kindergarten Class of 1998-1999. Data were analyzed using cross-classified multilevel latent growth curve modeling with time invariant and varying covariates. School-based…

  4. Thermostability of IFN-γ and IP-10 release assays for latent infection with Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Blauenfeldt, Thomas; Wagner, Dirk; Aabye, Martine;

    2016-01-01

    INTRODUCTION: Interferon-γ (IFN-γ) inducible protein 10kD (IP-10) and IFN-γ release assays (IGRAs) are immunodiagnostic tests aiming to identify the presence of specific cellular immune responses, interpreted as markers for latent infection with Mycobacterium tuberculosis. Incubation at higher te...

  5. Evaporative cooling: Effective latent heat of evaporation in relation to evaporation distance from the skin

    NARCIS (Netherlands)

    Havenith, G.; Bröde, P.; Hartog, E.A. den; Kuklane, K.; Holmer, I.; Rossi, R.M.; Richards, M.; Farnworth, B.; Wang, X.

    2013-01-01

    Calculation of evaporative heat loss is essential to heat balance calculations. Despite recognition that the value for latent heat of evaporation, used in these calculations, may not always reflect the real cooling benefit to the body, only limited quantitative data on this is available, which has f

  6. Detecting Growth Shape Misspecifications in Latent Growth Models: An Evaluation of Fit Indexes

    Science.gov (United States)

    Leite, Walter L.; Stapleton, Laura M.

    2011-01-01

    In this study, the authors compared the likelihood ratio test and fit indexes for detection of misspecifications of growth shape in latent growth models through a simulation study and a graphical analysis. They found that the likelihood ratio test, MFI, and root mean square error of approximation performed best for detecting model misspecification…

  7. A Direct Latent Variable Modeling Based Method for Point and Interval Estimation of Coefficient Alpha

    Science.gov (United States)

    Raykov, Tenko; Marcoulides, George A.

    2015-01-01

    A direct approach to point and interval estimation of Cronbach's coefficient alpha for multiple component measuring instruments is outlined. The procedure is based on a latent variable modeling application with widely circulated software. As a by-product, using sample data the method permits ascertaining whether the population discrepancy…

  8. Paternal Work Stress and Latent Profiles of Father-Infant Parenting Quality

    Science.gov (United States)

    Goodman, W. Benjamin; Crouter, Ann C.; Lanza, Stephanie T.; Cox, Martha J.; Vernon-Feagans, Lynne

    2011-01-01

    The current study used latent profile analysis (LPA) to examine the implications of fathers' experiences of work stress for paternal behaviors with infants across multiple dimensions of parenting in a sample of fathers living in nonmetropolitan communities (N = 492). LPA revealed five classes of fathers based on levels of social-affective…

  9. Dr. Lu Renhe's Experience in Treating Latent Nephritis with Traditional Chinese Medicine

    Institute of Scientific and Technical Information of China (English)

    Chen Jie

    2005-01-01

    @@ Dr. Lu Renhe of the First Clinical Medical College affiliated to Beijing University of Traditional Chinese Medicine has engaged in clinical practice,teaching and research for more than 40 years and accumulated rich experience of treating various kinds of nephritis, diabetes and their complications.The following is an introduction to his experience of treating latent nephritis.

  10. A new method of artificial latent fingerprint creation using artificial sweat and inkjet printer.

    Science.gov (United States)

    Hong, Sungwook; Hong, Ingi; Han, Aleum; Seo, Jin Yi; Namgung, Juyoung

    2015-12-01

    In order to study fingerprinting in the field of forensic science, it is very important to have two or more latent fingerprints with identical chemical composition and intensity. However, it is impossible to obtain identical fingerprints, in reality, because fingerprinting comes out slightly differently every time. A previous research study had proposed an artificial fingerprint creation method in which inkjet ink was replaced with amino acids and sodium chloride solution: the components of human sweat. But, this method had some drawbacks: divalent cations were not added while formulating the artificial sweat solution, and diluted solutions were used for creating weakly deposited latent fingerprint. In this study, a method was developed for overcoming the drawbacks of the methods used in the previous study. Several divalent cations were added in this study because the amino acid-ninhydrin (or some of its analogues) complex is known to react with divalent cations to produce a photoluminescent product; and, similarly, the amino acid-1,2-indanedione complex is known to be catalyzed by a small amount of zinc ions to produce a highly photoluminescent product. Also, in this study, a new technique was developed which enables to adjust the intensity when printing the latent fingerprint patterns. In this method, image processing software is used to control the intensity of the master fingerprint patterns, which adjusts the printing intensity of the latent fingerprints. This new method opened the way to produce a more realistic artificial fingerprint in various strengths with one artificial sweat working solution.

  11. Deep Processing Strategies and Critical Thinking: Developmental Trajectories Using Latent Growth Analyses

    Science.gov (United States)

    Phan, Huy P.

    2011-01-01

    The author explored the developmental courses of deep learning approach and critical thinking over a 2-year period. Latent growth curve modeling (LGM) procedures were used to test and trace the trajectories of both theoretical frameworks over time. Participants were 264 (119 women, 145 men) university undergraduates. The Deep Learning subscale of…

  12. Further Evidence for the Summation of Latent Inhibition and Overshadowing in Rats' Conditioned Taste Aversion

    Science.gov (United States)

    Nagaishi, Takatoshi; Nakajima, Sadahiko

    2008-01-01

    Repeated exposures to a target taste (X) attenuated subsequent development of rats' conditioned aversion to X (latent inhibition effect). Presentation of another taste (A) after X in conditioning (serial X-A compound conditioning) also attenuated conditioned X aversion compared with conditioning without A (overshadowing). Furthermore, the latent…

  13. Exponential martingale for compound Poisson process with latent variable and its applications

    Institute of Scientific and Technical Information of China (English)

    YAN Jun

    2015-01-01

    In this article, we construct an exponential martingale for the compound Poisson process with latent variable. With the help of this exponential martingale, we provide an asymptotic behavior of the coherent entropic risk measure for the compound Poisson process and a deviation inequality for the ruin probability of the partly shifted risk process.

  14. Using Latent Class Analysis to Identify Academic and Behavioral Risk Status in Elementary Students

    Science.gov (United States)

    King, Kathleen R.; Lembke, Erica S.; Reinke, Wendy M.

    2016-01-01

    Identifying classes of children on the basis of academic and behavior risk may have important implications for the allocation of intervention resources within Response to Intervention (RTI) and Multi-Tiered System of Support (MTSS) models. Latent class analysis (LCA) was conducted with a sample of 517 third grade students. Fall screening scores in…

  15. Latent Profile Analysis to Determine the Typology of Disinhibited Eating Behaviors in Children and Adolescents

    Science.gov (United States)

    Vannucci, Anna; Tanofsky-Kraff, Marian; Crosby, Ross D.; Ranzenhofer, Lisa M.; Shomaker, Lauren B.; Field, Sara E.; Mooreville, Mira; Reina, Samantha A.; Kozlosky, Merel; Yanovski, Susan Z.; Yanovski, Jack A.

    2013-01-01

    Objective: We used latent profile analysis (LPA) to classify children and adolescents into subtypes based on the overlap of disinhibited eating behaviors--eating in the absence of hunger, emotional eating, and subjective and objective binge eating. Method: Participants were 411 youths (8-18 years) from the community who reported on their…

  16. A person-fit index for polytomous Rasch models, latent class models, and their mixture generalizations

    NARCIS (Netherlands)

    von Davier, M; Molenaar, IW

    2003-01-01

    A normally distributed person-fit index is proposed for detecting aberrant response patterns in latent class models and mixture distribution IRT models for dichotomous and polytomous data. This article extends previous work on the null distribution of person-fit indices for the dichotomous Rasch mod

  17. Capitalism and Crime in the Classroom: An Analysis of Academic Dishonesty and Latent Student Attitudes

    Science.gov (United States)

    Burrus, Robert T.; Jones, Adam T.; Schuhmann, Peter W.

    2016-01-01

    University students' latent attitudes toward capitalism were quantified and used to predict self-reported cheating behaviors. Results suggest that the relationship between student academic dishonesty and attitudes toward capitalism are complex. Students indicating a strong degree of risk aversion are less likely to report cheating behaviors.…

  18. Substantial Molecular Evolution In Prolonged Latent Mycobacterium Tuberculosis Infections In Humans

    DEFF Research Database (Denmark)

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

    2015-01-01

    , as well as evidence for distinct processes such as oxidative damage or natural selection having contributed to mutation accumulation. Conclusions: Our study shows that distinct processes can shape Mtb genomes during latent infection. Most importantly, we document substantial molecular evolution of Mtb...

  19. Trading Dynamics in the Foreign Exchange Market: A Latent Factor Panel Intensity Approach

    DEFF Research Database (Denmark)

    Nolte, Ingmar; Voev, Valeri

    2011-01-01

    We develop a panel intensity framework for the analysis of complex trading activity datasets containing detailed information on individual trading actions in different securities for a set of investors. A feature of the model is the presence of a time varying latent factor, which captures...

  20. Cognitive Preconditions of Early Reading and Spelling: A Latent-Variable Approach with Longitudinal Data

    Science.gov (United States)

    Preßler, Anna-Lena; Könen, Tanja; Hasselhorn, Marcus; Krajewski, Kristin

    2014-01-01

    The aim of the present study was to empirically disentangle the interdependencies of the impact of nonverbal intelligence, working memory capacities, and phonological processing skills on early reading decoding and spelling within a latent variable approach. In a sample of 127 children, these cognitive preconditions were assessed before the onset…

  1. Latent Class Analysis of Peer Conformity: Who Is Yielding to Pressure and Why?

    Science.gov (United States)

    Kosten, Paul A.; Scheier, Lawrence M.; Grenard, Jerry L.

    2013-01-01

    This study used latent class analysis to examine typologies of peer conformity in a community sample of middle school students. Students responded to 31 items assessing diverse facets of conformity dispositions. The most parsimonious model produced three qualitatively distinct classes that differed on the basis of conformity to recreational…

  2. Longitudinal Changes in Physical Fitness Performance in Youth: A Multilevel Latent Growth Curve Modeling Approach

    Science.gov (United States)

    Wang, Chee Keng John; Pyun, Do Young; Liu, Woon Chia; Lim, Boon San Coral; Li, Fuzhong

    2013-01-01

    Using a multilevel latent growth curve modeling (LGCM) approach, this study examined longitudinal change in levels of physical fitness performance over time (i.e. four years) in young adolescents aged from 12-13 years. The sample consisted of 6622 students from 138 secondary schools in Singapore. Initial analyses found between-school variation on…

  3. Complete Genome Sequences of Peach Latent Mosaic Viroid from a Single Peach Cultivar

    OpenAIRE

    Jo, Yeonhwa; Yoo, Su-Hyun; Chu, Hyosub; Cho, Jin Kyong; Choi, Hoseong; Yoon, Ju-Yeon; Choi, Seung-Kook; Cho, Won Kyong

    2015-01-01

    Peach latent mosaic viroid (PLMVd) is a member of the genus Pelamoviroid in the family Avsunviroidae and infects peach trees. We de novo assembled a PLMVd genome from a peach transcriptome and identified 18 variants in a single peach cultivar, after sequencing 20 PLMVd genomes by Sanger sequencing.

  4. A Note on Confidence Intervals for Two-Group Latent Mean Effect Size Measures

    Science.gov (United States)

    Choi, Jaehwa; Fan, Weihua; Hancock, Gregory R.

    2009-01-01

    This note suggests delta method implementations for deriving confidence intervals for a latent mean effect size measure for the case of 2 independent populations. A hypothetical kindergarten reading example using these implementations is provided, as is supporting LISREL syntax. (Contains 1 table.)

  5. Multivariate Effect Size Estimation: Confidence Interval Construction via Latent Variable Modeling

    Science.gov (United States)

    Raykov, Tenko; Marcoulides, George A.

    2010-01-01

    A latent variable modeling method is outlined for constructing a confidence interval (CI) of a popular multivariate effect size measure. The procedure uses the conventional multivariate analysis of variance (MANOVA) setup and is applicable with large samples. The approach provides a population range of plausible values for the proportion of…

  6. Applications of Latent-Variable Models in Educational Psychology: The Need for Methodological-Substantive Synergies

    Science.gov (United States)

    Marsh, Herbert W.; Hau, Kit-Tai

    2007-01-01

    As emphasized in the call for papers by Jonna Kulikowich and Gregory Hancock, the primary goal of this special issue of "Contemporary Educational Psychology" is to assemble a collection of illustrative empirical studies in educational psychology that utilize one or more state-of-the-art latent variable modeling procedures. Distinguishing these…

  7. Specification Search for Identifying the Correct Mean Trajectory in Polynomial Latent Growth Models

    Science.gov (United States)

    Kim, Minjung; Kwok, Oi-Man; Yoon, Myeongsun; Willson, Victor; Lai, Mark H. C.

    2016-01-01

    This study investigated the optimal strategy for model specification search under the latent growth modeling (LGM) framework, specifically on searching for the correct polynomial mean or average growth model when there is no a priori hypothesized model in the absence of theory. In this simulation study, the effectiveness of different starting…

  8. Modeling anger and aggressive driving behavior in a dynamic choice-latent variable model.

    Science.gov (United States)

    Danaf, Mazen; Abou-Zeid, Maya; Kaysi, Isam

    2015-02-01

    This paper develops a hybrid choice-latent variable model combined with a Hidden Markov model in order to analyze the causes of aggressive driving and forecast its manifestations accordingly. The model is grounded in the state-trait anger theory; it treats trait driving anger as a latent variable that is expressed as a function of individual characteristics, or as an agent effect, and state anger as a dynamic latent variable that evolves over time and affects driving behavior, and that is expressed as a function of trait anger, frustrating events, and contextual variables (e.g., geometric roadway features, flow conditions, etc.). This model may be used in order to test measures aimed at reducing aggressive driving behavior and improving road safety, and can be incorporated into micro-simulation packages to represent aggressive driving. The paper also presents an application of this model to data obtained from a driving simulator experiment performed at the American University of Beirut. The results derived from this application indicate that state anger at a specific time period is significantly affected by the occurrence of frustrating events, trait anger, and the anger experienced at the previous time period. The proposed model exhibited a better goodness of fit compared to a similar simple joint model where driving behavior and decisions are expressed as a function of the experienced events explicitly and not the dynamic latent variable.

  9. Aptitude, Achievement and Competence in Medicine: A Latent Variable Path Model

    Science.gov (United States)

    Collin, V. Terri; Violato, Claudio; Hecker, Kent

    2009-01-01

    To develop and test a latent variable path model of general achievement, aptitude for medicine and competence in medicine employing data from the Medical College Admission Test (MCAT), pre-medical undergraduate grade point average (UGPA) and demographic characteristics for competence in pre-clinical and measures of competence (United States…

  10. The effect of prolonged monocular occlusion on latent nystagmus in the treatment of amblyopia

    NARCIS (Netherlands)

    H.J. Simonsz (Huib)

    1989-01-01

    textabstractWe recorded eye movements in 5 patients with latent nystagmus (LN) before and after 2 days of occlusion of the better eye. The slow-phase speed of the nystagmus (SPS) was in general, before occlusion, lower when the better eye fixated but, after occlusion, lower when the worse eye fixate

  11. Latent Patterns of Risk Behavior in Urban African-American Middle School Students in Baltimore City

    Science.gov (United States)

    Hedden, Sarra L.; Whitaker, Damiya E.; von Thomsen, Sarah; Severtson, S. Geoffrey; Latimer, William W.

    2011-01-01

    Students who engage in high-risk behaviors, including early initiation of sexual intercourse, alcohol use, marijuana use, tobacco use, and externalizing behavior are vulnerable to a broad range of adverse outcomes as adults. Latent class analysis was used to determine whether varying patterns of risk behavior existed for 212 urban African-American…

  12. An Explanation of the Effectiveness of Latent Semantic Indexing by Means of a Bayesian Regression Model.

    Science.gov (United States)

    Story, Roger E.

    1996-01-01

    Discussion of the use of Latent Semantic Indexing to determine relevancy in information retrieval focuses on statistical regression and Bayesian methods. Topics include keyword searching; a multiple regression model; how the regression model can aid search methods; and limitations of this approach, including complexity, linearity, and…

  13. Divorce and Child Behavior Problems: Applying Latent Change Score Models to Life Event Data

    Science.gov (United States)

    Malone, Patrick S.; Lansford, Jennifer E.; Castellino, Domini R.; Berlin, Lisa J.; Dodge, Kenneth A.; Bates, John E.; Pettit, Gregory S.

    2004-01-01

    Effects of parents' divorce on children's adjustment have been studied extensively. This article applies new advances in trajectory modeling to the problem of disentangling the effects of divorce on children's adjustment from related factors such as the child's age at the time of divorce and the child's gender. Latent change score models were used…

  14. A Taxometric Study of the Latent Structure of Disgust Sensitivity: Converging Evidence for Dimensionality

    Science.gov (United States)

    Olatunji, Bunmi O.; Broman-Fulks, Joshua J.

    2007-01-01

    Disgust sensitivity has recently been implicated as a specific vulnerability factor for several anxiety-related disorders. However, it is not clear whether disgust sensitivity is a dimensional or categorical phenomenon. The present study examined the latent structure of disgust by applying three taxometric procedures (maximum eigenvalue, mean…

  15. The Measurement of the Specific Latent Heat of Fusion of Ice: Two Improved Methods.

    Science.gov (United States)

    Mak, S. Y.; Chun, C. K. W.

    2000-01-01

    Suggests two methods for measuring the specific latent heat of ice fusion for high school physics laboratories. The first method is an ice calorimeter which is made from simple materials. The second method improves the thermal contact and allows for a more accurate measurement. Lists instructions for both methods. (Author/YDS)

  16. Exploring context and content links in social media: a latent space method.

    Science.gov (United States)

    Qi, Guo-Jun; Aggarwal, Charu; Tian, Qi; Ji, Heng; Huang, Thomas S

    2012-05-01

    Social media networks contain both content and context-specific information. Most existing methods work with either of the two for the purpose of multimedia mining and retrieval. In reality, both content and context information are rich sources of information for mining, and the full power of mining and processing algorithms can be realized only with the use of a combination of the two. This paper proposes a new algorithm which mines both context and content links in social media networks to discover the underlying latent semantic space. This mapping of the multimedia objects into latent feature vectors enables the use of any off-the-shelf multimedia retrieval algorithms. Compared to the state-of-the-art latent methods in multimedia analysis, this algorithm effectively solves the problem of sparse context links by mining the geometric structure underlying the content links between multimedia objects. Specifically for multimedia annotation, we show that an effective algorithm can be developed to directly construct annotation models by simultaneously leveraging both context and content information based on latent structure between correlated semantic concepts. We conduct experiments on the Flickr data set, which contains user tags linked with images. We illustrate the advantages of our approach over the state-of-the-art multimedia retrieval techniques. PMID:21968917

  17. Isoniazid Completion Rates for Latent Tuberculosis Infection among College Students Managed by a Community Pharmacist

    Science.gov (United States)

    Hess, Karl; Goad, Jeffery; Wu, Joanne; Johnson, Kathleen

    2009-01-01

    Objective: The authors' objective was to document 9-month and previously recommended 6-month treatment completion rates for latent tuberculosis infection (LTBI) in a pharmacist-managed LTBI clinic in a community pharmacy on a college campus, and to describe patient characteristics. Participants: Participants were university students diagnosed with…

  18. Self-Esteem and Delinquency in South Korean Adolescents: Latent Growth Modeling

    Science.gov (United States)

    Lee, Kyungeun; Lee, Julie

    2012-01-01

    This study examined the inter-related development of self-esteem and delinquency across three years. Participants were 3449 Korean high school adolescents (age M = 15.8, SD = 0.42, 1725 boys, 1724 girls) from Korea Youth Panel Study (KYPS), in 2005-2007, nationally representative of Korean adolescents. Latent growth modeling was employed for…

  19. 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

    BACKGROUND: 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...

  20. Sensible and latent heat flux from radiometric surface temperatures at the regional scale: methodology and validation

    NARCIS (Netherlands)

    Miglietta, F.; Gioli, B.; Brunet, Y.; Hutjes, R.W.A.; Matese, A.; Sarrat, C.; Zaldei, A.

    2009-01-01

    The CarboEurope Regional Experiment Strategy (CERES) was designed to develop and test a range of methodologies to assess regional surface energy and mass exchange of a large study area in the south-western part of France. This paper describes a methodology to estimate sensible and latent heat fluxes

  1. Examining Combinations of Social Physique Anxiety and Motivation Regulations Using Latent Profile Analysis

    Science.gov (United States)

    Ullrich-French, Sarah; Cox, Anne E.; Cooper, Brittany Rhoades

    2016-01-01

    Previous research has used cluster analysis to examine how social physique anxiety (SPA) combines with motivation in physical education. This study utilized a more advanced analytic approach, latent profile analysis (LPA), to identify profiles of SPA and motivation regulations. Students in grades 9-12 (N = 298) completed questionnaires at two time…

  2. A latent class distance association model for cross-classified data with a categorical response variable

    NARCIS (Netherlands)

    Vera, J.F.; Rooij, M. de; Heiser, W.J.

    2014-01-01

    In this paper we propose a latent class distance association model for clustering in the predictor space of large contingency tables with a categorical response variable. The rows of such a table are characterized as profiles of a set of explanatory variables, while the columns represent a single ou

  3. Vaccinia Virus Recombinant Expressing Herpes Simplex Virus Type 1 Glycoprotein D Prevents Latent Herpes in Mice

    Science.gov (United States)

    Cremer, Kenneth J.; Mackett, Michael; Wohlenberg, Charles; Notkins, Abner Louis; Moss, Bernard

    1985-05-01

    In humans, herpes simplex virus causes a primary infection and then often a latent ganglionic infection that persists for life. Because these latent infections can recur periodically, vaccines are needed that can protect against both primary and latent herpes simplex infections. Infectious vaccinia virus recombinants that contain the herpes simplex virus type 1 (HSV-1) glycoprotein D gene under control of defined early or late vaccinia virus promoters were constructed. Tissue culture cells infected with these recombinant viruses synthesized a glycosylated protein that had the same mass (60,000 daltons) as the glycoprotein D produced by HSV-1. Immunization of mice with one of these recombinant viruses by intradermal, subcutaneous, or intraperitoneal routes resulted in the production of antibodies that neutralized HSV-1 and protected the mice against subsequent lethal challenge with HSV-1 or HSV-2. Immunization with the recombinant virus also protected the majority of the mice against the development of a latent HSV-1 infection of the trigeminal ganglia. This is the first demonstration that a genetically engineered vaccine can prevent the development of latency.

  4. Measurement Equivalence of Teachers' Sense of Efficacy Scale Using Latent Growth Methods

    Science.gov (United States)

    Basokçu, T. Oguz; Ögretmen, T.

    2016-01-01

    This study is based on the application of latent growth modeling, which is one of structural equation models on real data. Teachers' Sense of Efficacy Scale (TSES), which was previously adapted into Turkish was administered to 200 preservice teachers at different time intervals for three times and study data was collected. Measurement equivalence…

  5. Latent Class Models for Diary Method Data: Parameter Estimation by Local Computations

    Science.gov (United States)

    Rijmen, Frank; Vansteelandt, Kristof; De Boeck, Paul

    2008-01-01

    The increasing use of diary methods calls for the development of appropriate statistical methods. For the resulting panel data, latent Markov models can be used to model both individual differences and temporal dynamics. The computational burden associated with these models can be overcome by exploiting the conditional independence relations…

  6. Latent Semantic Analysis as a Method of Content-Based Image Retrieval in Medical Applications

    Science.gov (United States)

    Makovoz, Gennadiy

    2010-01-01

    The research investigated whether a Latent Semantic Analysis (LSA)-based approach to image retrieval can map pixel intensity into a smaller concept space with good accuracy and reasonable computational cost. From a large set of M computed tomography (CT) images, a retrieval query found all images for a particular patient based on semantic…

  7. A Bayesian latent group analysis for detecting poor effort in the assessment of malingering

    NARCIS (Netherlands)

    A. Ortega; E.-J. Wagenmakers; M.D. Lee; H.J. Markowitsch; M. Piefke

    2012-01-01

    Despite their theoretical appeal, Bayesian methods for the assessment of poor effort and malingering are still rarely used in neuropsychological research and clinical diagnosis. In this article, we outline a novel and easy-to-use Bayesian latent group analysis of malingering whose goal is to identif

  8. Global Convergence of the EM Algorithm for Unconstrained Latent Variable Models with Categorical Indicators

    Science.gov (United States)

    Weissman, Alexander

    2013-01-01

    Convergence of the expectation-maximization (EM) algorithm to a global optimum of the marginal log likelihood function for unconstrained latent variable models with categorical indicators is presented. The sufficient conditions under which global convergence of the EM algorithm is attainable are provided in an information-theoretic context by…

  9. A mixture model for the joint analysis of latent developmental trajectories and survival

    NARCIS (Netherlands)

    Klein Entink, R.H.; Fox, J.P.; Hout, A. van den

    2011-01-01

    A general joint modeling framework is proposed that includes a parametric stratified survival component for continuous time survival data, and a mixture multilevel item response component to model latent developmental trajectories given mixed discrete response data. The joint model is illustrated in

  10. A Latent Class Analysis of Dyadic Perfectionism in a College Sample

    Science.gov (United States)

    Lopez, Frederick G.; Fons-Scheyd, Alia; Bush-King, Imelda; McDermott, Ryon C.

    2011-01-01

    A latent class analysis of dyadic perfectionism scores within a college sample (N = 369) identified four classes of participants. Controlling for gender and current dating status, class membership was associated with significant differences on several measures of relationship attitudes. Gender and class membership also significantly interacted in…

  11. Experimental investigations on cylindrical latent heat storage units with sodium acetate trihydrate composites utilizing supercooling

    DEFF Research Database (Denmark)

    Dannemand, Mark; Johansen, Jakob Berg; Kong, Weiqiang;

    2016-01-01

    Latent heat storage units utilizing stable supercooling of sodium acetate trihydrate (SAT) composites were tested in a laboratory. The stainless steel units were 1.5 m high cylinders with internal heat exchangers of tubes with fins. One unit was tested with 116 kg SAT with 6% extra water. Another...

  12. Latent Curve Modeling of Internalizing Behaviors and Interpersonal Skills through Elementary School

    Science.gov (United States)

    Reynolds, Matthew R.; Sander, Janay B.; Irvin, Matthew J.

    2010-01-01

    The trajectories of internalizing and interpersonal behaviors from kindergarten through fifth grade were studied using univariate and bivariate latent curve models. Internalizing behaviors demonstrated a small, yet statistically significant, linear increase over time, while interpersonal behaviors showed a small, yet statistically significant,…

  13. Structural Equation Models of Latent Interactions: Evaluation of Alternative Estimation Strategies and Indicator Construction

    Science.gov (United States)

    Marsh, Herbert W.; Wen, Zhonglin; Hau, Kit-Tai

    2004-01-01

    Interactions between (multiple indicator) latent variables are rarely used because of implementation complexity and competing strategies. Based on 4 simulation studies, the traditional constrained approach performed more poorly than did 3 new approaches-unconstrained, generalized appended product indicator, and quasi-maximum-likelihood (QML). The…

  14. Latent manganese deficiency increases transpiration in barley (Hordeum vulgare)

    DEFF Research Database (Denmark)

    Hebbern, Christopher Alan; Laursen, Kristian Holst; Ladegaard, Anne Hald;

    2009-01-01

    To investigate if latent manganese (Mn) deficiency leads to increased transpiration, barley plants were grown for 10 weeks in hydroponics with daily additions of Mn in the low nM range. The Mn-starved plants did not exhibit visual leaf symptoms of Mn deficiency, but Chl a fluorescence measurements...

  15. Measurement Invariance and Latent Mean Differences of the Beck Depression Inventory II across Gender Groups

    Science.gov (United States)

    Wu, Pei-Chen

    2010-01-01

    This study examined measurement invariance (i.e., configural invariance, metric invariance, scalar invariance) of the Chinese version of Beck Depression Inventory II (BDI-II-C) across college males and females and compared gender differences on depression at the latent factor mean level. Two samples composed of 402 male college students and 595…

  16. A Latent Profile Analysis of Math Achievement, Numerosity, and Math Anxiety in Twins

    Science.gov (United States)

    Hart, Sara A.; Logan, Jessica A. R.; Thompson, Lee; Kovas, Yulia; McLoughlin, Gráinne; Petrill, Stephen A.

    2016-01-01

    Underperformance in math is a problem with increasing prevalence, complex etiology, and severe repercussions. This study examined the etiological heterogeneity of math performance in a sample of 264 pairs of 12-year-old twins assessed on measures of math achievement, numerosity, and math anxiety. Latent profile analysis indicated 5 groupings of…

  17. Structural Equation Models of Latent Interactions: An Appropriate Standardized Solution and Its Scale-Free Properties

    Science.gov (United States)

    Wen, Zhonglin; Marsh, Herbert W.; Hau, Kit-Tai

    2010-01-01

    Standardized parameter estimates are routinely used to summarize the results of multiple regression models of manifest variables and structural equation models of latent variables, because they facilitate interpretation. Although the typical standardization of interaction terms is not appropriate for multiple regression models, straightforward…

  18. Evaluations of Child Sexual Abuse: Recognition of Overt and Latent Family Concerns

    Science.gov (United States)

    Leventhal, John M.; Murphy, Janet L.; Asnes, Andrea G.

    2010-01-01

    Objective: To describe a clinical approach to the recognition of overt and latent concerns of parents and children when children are evaluated for suspected sexual abuse by medical examiners. Method: Description of a clinical approach. Results: We describe 10 concerns-six of parents: (1) should we believe our child?; (2) worries about the child's…

  19. Testing Latent Mean Differences between Observed and Unobserved Groups Using Multilevel Factor Mixture Models

    Science.gov (United States)

    Allua, Shane; Stapleton, Laura M.; Beretvas, S. Natasha

    2008-01-01

    When assessing latent mean differences, researchers frequently do not explore possible heterogeneity within their data sets. Sources of differences may be functions of a nested data structure or heterogeneity in the form of unobserved classes of observations defined by a difference in factor means. In this study, the use of multilevel structural…

  20. What Do Test Scores Really Mean? A Latent Class Analysis of Danish Test Score Performance

    DEFF Research Database (Denmark)

    Munk, Martin D.; McIntosh, James

    2014-01-01

    Latent class Poisson count models are used to analyze a sample of Danish test score results from a cohort of individuals born in 1954-55, tested in 1968, and followed until 2011. The procedure takes account of unobservable effects as well as excessive zeros in the data. We show that the test scores...