WorldWideScience

Sample records for autoinmune latente del

  1. Nueva definición, prevalencia, caracterización y tratamiento de la diabetes autoinmune latente del adulto A new definition, prevalence, characterization, and treatment of the latent autoimmune diabetes of adult

    Directory of Open Access Journals (Sweden)

    Eduardo Cabrera Rode

    2008-12-01

    Full Text Available La diabetes autoinmune latente del adulto es una forma de diabetes autoinmune que está presente en algunos sujetos equívocamente clasificados como diabéticos tipo 2. La progresión del daño autoinmune de las células ß en esta entidad es más lenta que en los niños con diabetes tipo 1. Las personas que la padecen, al momento del diagnóstico, presentan una mayor preservación de la función de las células ß que aquellos con la diabetes tipo 1 clásica. Su diagnóstico actual está basado en 3 características: edad igual o superior a 30 años (aunque se pueda encontrar también en sujetos con edades inferiores a 30 años; la presencia de al menos 1 de los 5 autoanticuerpos contra los antígenos pancreáticos de las células de los islotes (autoanticuerpos antiislotes [ICA], antidescarboxilasa del ácido glutámico [AGAD], anticuerpos contra la tirosina fosfatasa [AIA2] y contra el transportador del catión zinc dentro las células de los islotes [AZnT8], y la necesidad de requerimientos de insulina, al menos 6 meses después del diagnóstico. Está presente en el 10 % de los individuos con diabetes tipo 2 con edades ³35 años y en el 25 % de los menores de 35. Se han descrito varios genes de susceptibilidad para ella, que incluyen los genes HLA DR3/DR4 y DQB1*0201/DQB1*0302, DQB1*0602, MHC clase I relacionados con la cadena A (MICA, así como del alelo VNTR clase I, entre otros, los que la asemejan o diferencian tanto de la diabetes tipo 1 clásica como de la tipo 2. Estudios prospectivos sobre la función de las células ß muestran que los sujetos que tienen múltiples autoanticuerpos asociados a diabetes tipo 1, desarrollan un fallo de la función de las células ß dentro de los primeros 5 años de duración de la diabetes, mientras que la mayoría de aquellos con solo AGAD ó ICA desarrollan el fallo de la función de estas células después de los 5 años. En estas personas puede ocurrir un fallo de la función de las células

  2. Diabetes autoinmune latente del adulto o diabetes tipo 1 de lenta progresión: definición, patogenia, clínica, diagnóstico y tratamiento Latent autoimmune diabetes of the adult or type 1 diabetes of slow progression: definition, pathogeny, clinic, diagnosis and treatment

    Directory of Open Access Journals (Sweden)

    Eduardo Cabrera Rode

    2002-04-01

    Full Text Available Se sabe que la diabetes mellitus es un síndrome heterogéneo que tiene como elemento común una hiperglucemia crónica, como consecuencia de una deficiencia de insulina o una insuficiente efectividad de su acción. Nos propusimos en este trabajo describir los aspectos más relevantes de la diabetes autoinmune del adulto (LADA y exponer el resultado de nuestra experiencia. Se considera que un sujeto la padece cuando es clasificado inicialmente como diabético tipo 2, el inicio es después de los 34 años, tiene generalmente peso corporal, normal o bajo y en un tiempo relativamente corto necesita tratamiento insulínico para lograr un buen control metabólico y presenta además una mayor asociación con la producción de anticuerpos antiislotes (ICA, antiglutámico descarboxilasa (AGAD65, microsomales tiroideos y antigástricos parietales, con una susceptibilidad genética por la presencia de haplotipos HLA-DR. Al momento del diagnóstico clínico puede presentar o no una insulinodeficiencia. Se ha demostrado que la insulinoterapia es el tratamiento ideal para los individuos con LADA, con el mismo se ha evidenciado una alta tasa de conversión negativa de los ICA con un incremento de los niveles de péptido C en el suero. Por el contrario, el tratamiento con sulfonilureas produce una persistencia de los ICA, los que probablemente sean responsables de una destrucción progresiva de las células b del páncreas. Por tanto, estas observaciones justifican la elección de la insulinoterapia desde el mismo momento del diagnóstico.It is known that diabetes mellitus is an heterogeneous syndrome that has as a common element a chronic hyperglycaemia resulting from an insulin deficiency or from an insufficient effectiveness of its action. It is our purpose to describe the most significant aspects of the autoimmune diabetes of the adult and to show the result of our experience. It is considered that subjects suffer from it when they are initially classified

  3. Seroprevalencia del Virus Linfotrópico Humano de células T tipo 1 (HTLV-1 en pacientes con tiroiditis autoinmune.

    Directory of Open Access Journals (Sweden)

    Ricardo Mori

    2010-10-01

    Full Text Available Objetivo: Describir la seroprevalencia de infección por HTLV-1 en pacientes con tiroiditis autoinmune. Material y Métodos: Estudio transversal realizado en pacientes con tiroiditis autoinmune que acudieron al consultorio de Endocrinología del Hospital Nacional Cayetano Heredia entre octubre del 2008 y enero del 2010. Se usó un cuestionario estructurado para obtener datos epidemiológicos y clínicos, paralelamente, se revisaron las historias clínicas para obtener datos de laboratorio. A los participantes se les tomó una muestra de sangre para el diagnóstico de HTLV-1 mediante prueba de ELISA y confirmación por Western Blot, previa firma de consentimiento informado. Resultados: Durante el período de estudio, se atendieron 285 pacientes con tiroiditis autoinmune. Se incluyeron 145 pacientes (50,9%; la edad media fue 48,1 ± 15 años y 135 (93,1% fueron de sexo femenino. Tres pacientes tuvieron infección por HTLV-1, con una prevalencia estimada de 2,1% (IC 95%: 0-4,4%. Los seropositivos fueron de sexo femenino y tuvieron el diagnóstico de Enfermedad de Graves hipertiroidea. La frecuencia de infección por HTLV-1 en este grupo fue de 5% (3/60; IC 95%: 0-11%. No se encontró diferencia significativa entre los pacientes HTLV-1 positivos y negativos en cuanto a características demográficas, clínicas y de laboratorio. Conclusión: La prevalencia de infección por HTLV-1 en los pacientes con tiroiditis autoinmune fue similar a la prevalencia estimada para la población peruana en general.(Rev Med Hered 2010;21:180-186.

  4. Tiroiditis no-autoinmunes

    Directory of Open Access Journals (Sweden)

    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. Encefalitis autoinmune en pediatría

    Directory of Open Access Journals (Sweden)

    Juan Carlos García-Beristáin

    2017-06-01

    Full Text Available La encefalitis es un desorden inflamatorio del encéfalo que deriva en un estado mental alterado, crisis convulsivas, déficits neurológicos focales, acompañado usualmente de signos de inflamación en el líquido cefalorraquídeo y hallazgos en la resonancia magnética que pueden ir desde normalidad hasta anormalidades extensas. La encefalitis puede ocurrir como resultado de una infección primaria del sistema nervioso central, o bien, por un proceso autoinmune desencadenado por una infección, vacuna o neoplasia oculta. La encefalitis autoinmune involucra varios tipos de entidades con diferentes fisiopatologías, el entender estas entidades nos ayuda a utilizar los recursos y elementos diagnósticos necesarios, así como la mejor estrategia terapéutica.

  6. La crisis latente del Darwinismo

    Directory of Open Access Journals (Sweden)

    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.

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. Diabetes autoinmune del adulto en diabéticos tipo 2: frecuencia y características LADA in type 2 diabetics: frequency and characteristics

    Directory of Open Access Journals (Sweden)

    Eduardo Cabrera-Rode

    2001-04-01

    Full Text Available Se realizó este trabajo para conocer frecuencia, características clínico-bioquímicas, inmunológicas y genéticas de la diabetes autoinmune en adultos (LADA en 1 000 diabéticos tipo 2 con edades ³ 35 años con distintos tiempos de duración de la diabetes. Se les determinó glucemia, anticuerpos antiislotes pancreáticos (ICA, anti-GAD65, anti-ICA512bdc/IA2, antimicrosomales tiroideos (AMT, antigástricos parietales (AGP, antinucleares (AN, microalbuminuria y péptido C en ayunas. Se encuestaron y se registraron algunas características clínicas. Se dividieron en 2 grupos según la presencia de ICA. Todos los diabéticos tipo 2 + para autoanticuerpos antiislotes (ICA y/o anti-GAD65 fueron identificados como LADA. Se detectó el 3,4 % de diabético tipo 2 con ICA +, en los diabéticos tipo 2 ICA- el 22,0 % presentó anticuerpos anti-GAD65. Se encontró que los diabéticos tipo 2 ICA+ eran más jóvenes, la duración de su diabetes era menor, presentaron menor IMC, disminución de los niveles de péptido C en ayunas, menos antecedentes familiares (padres de DM2, valores menores en las tensiones arteriales diastólicas y sistólicas, mayor presencia de anticuerpos anti-GAD65, AMT y AGP en comparación con los diabéticos tipo 2 ICA-. Se observó que los diabéticos tipo 2 ICA+ (LADA tienen características específicas que los asemejan a los diabéticos tipo 1, esto implicaría variaciones importantes en su tratamiento y evolución con respecto a los diabéticos tipo 2 ICA-. Se observó una baja frecuencia de ICA y alta de GAD en los diabéticos tipo 2 cubanos, las cuales fueron diferentes a la encontrada en poblaciones caucasianas. Los anticuerpos anti-GAD65 fueron superiores a los ICA para detectar los LADA. Las características clínicas e inmunológicas de estos pacientes muestran la lenta progresión de la destrucción autoinmune de las células b con implicaciones terapéuticas.This paper was aimed at knowing the frequency, clinico

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  11. Posible participación del sistema complemento en el desarrollo de manifestaciones autoinmunes en la leucemia linfocítica crónica Possible role of the complement system in the development of autoimmune manifestations in chronic lymphocytic leukemias

    Directory of Open Access Journals (Sweden)

    Rinaldo Villaescusa Blanco

    2002-04-01

    Full Text Available Se efectuó la medición de la actividad de la vía clásica, alternativa, factor B, factor D, así como la cuantificación de C1q, C3 y C4 del sistema complemento en 27 pacientes con leucemia linfocítica crónica de tipo B (LLC-B CD5+ estadificados en 2 grupos: 12 pacientes en fase poco avanzada de la enfermedad (estadios 0, I, II y 15 en fase avanzada (estadios III, IV. Se demostró una disminución de la actividad de la vía clásica y de la concentración de C1q y C4 en 10 pacientes en fase avanzada, 7 de los cuales tenían asociada una anemia hemolítica autoinmune (AHAI; en el grupo en fase poco avanzada de la enfermedad no se demostraron deficiencias de complemento ni manifestaciones autoinmunes. Los datos obtenidos sugieren la posible participación del sistema complemento en el mantenimiento de la tolerancia inmunológica, cuya ruptura pudiera provocar la síntesis de anticuerpos antieritrocitarios, y por lo tanto, la anemia hemolítica que se asocia en determinados pacientes en fase avanzada de la enfermedadThe measurement of the activity of the classical pathway, the alternative pathway, factor B, factor D, as well as the quantification of Clq, C3 and C4 of the complement system were made in 27 patients with type B chronic lymphocytic leukemia (CLL-B CD5+, classified into 2 groups: 12 patients at little advanced stage of the disease (stages 0, I, II and 15 patients at advanced stage (stages III, IV. It was proved that the activity of the classical pathway and the concentration of Clq and C4 lowered in 10 patients at advanced stage, 7 of them also had autoimmune hemolytic anemia. Neither complement deficiencies nor autoimmune manifestations were shown in the group of patients at little advanced stage of the disease. Collected data indicates the possible involvement of the complement system in keeping the immune tolerance, the rupture of which may cause the synthesis of anti-erythrocyte antibodies and thus, the hemolytic anemia that

  12. Anticoagulante lúpico en enfermedades autoinmunes Lupus anticoagulant in autoimmune diseases

    Directory of Open Access Journals (Sweden)

    Dunia de la C Castillo González

    2004-08-01

    Full Text Available El tromboembolismo venoso es una complicación reconocida en diferentes enfermedades autoinmunes. Se ha establecido que la detección del anticoagulante lúpico (AL y posiblemente los anticuerpos anticardiolipina (AAC tipo Ig G en título alto y medio, ayuden a identificar pacientes con riesgo de trombosis. Estudiamos el AL en 81 pacientes con enfermedades autoinmunes: 25 pacientes con lupus eritematoso sistémico (LES, 28 pacientes con púrpura trombocitopénica idiopática (PTI, 15 con anemia hemolítica autoinmune (AHAI y 13 que se incluyeron en el grupo de otras enfermedades, que comprendían vasculitis cutánea de pequeños vasos, enfermedad mixta del tejido conectivo, artritis reumatoidea y esclerodermia. El AL se encontró en el 19,7 % del total de los estudiados: 16 % en pacientes con LES, 21,4 % en pacientes con PTI y 40 % en la AHAI. En el grupo de otras enfermedades no se halló ningún paciente con el AL positivo. El 56,3 % de los pacientes con AL positivo presentaron alguna manifestación atribuible al síndrome antifosfolípido (SAFVenous thromboembolism is a well-known complication in different autoimmune diseases. It has been established that detection of lupus anticoagulant (LA and possibly IgG type anticardiolipin antibodies (AAC in high and medium titers help to identify patients with thrombosis risk. We studied LA in 81 patients with autoimmune erythomatous lupus, 28 patients with idiopathic thrombocytopenic purpura, 15 with autoimmune hemolytic anemia and 13 patients who were included in the group covering other diseases such as small vessel skin vasculitis, combined disease of the connective tissue, rheumatoid arthritis and sclerodermia. LA was found in 19,7 % of the total number of cases, in 16% of patients with LES, 21,4 % of those with ITP and 40 % of cases with AIHA. In the group of other diseases, there was no patient with positive LA. 56,3 % of patients with positive AL showed some manifestations related to

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Modalidades terapéuticas en la fase latente prolongada del trabajo de parto Therapeutic modalities in the prolonged latent phase of labor

    Directory of Open Access Journals (Sweden)

    Danilo Nápoles Méndez

    2012-05-01

    Full Text Available En el trabajo de parto, la distocia de fase latente constituye una entidad clínica relacionada con el aumento de la morbilidad y mortalidad materna y perinatal. En este artículo se exponen las modalidades de tratamiento para el trastorno de esta fase del trabajo de parto, a fin de que los obstetras posean alternativas terapéuticas que posibiliten una mayor preparación en la toma de decisiones. Asimismo, se describen tanto las formas de terapia conservadora (reposo terapéutico, como las de la activa. Se concluye que el tratamiento activo no invasivo de base etiológica con misoprostol y la terapia activa con oxitocina y rotura artificial de membranas tardía, son modalidades empleadas en obstetricia con resultados satisfactorios.Dystocia of latent phase constitutes a clinical entity related to the increase of maternal and perinatal morbidity and mortality during labor. The treatment modalities for the disorder of this phase of labor are exposed in this work, so that the obstetricians have therapeutic alternatives which facilitate a greater preparation in the decision-making process. The ways for conservative therapy (therapeutic rest and active therapy are also described. It is concluded that the non-invasive active treatment of etiological basis with misoprostol and the active therapy with oxytocin and late artificial rupture of membranes are the modalities used in obstetrics with satisfactory results.

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

    Directory of Open Access Journals (Sweden)

    M. Romero

    2008-10-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Estructura Latente de las Funciones Ejecutivas en Adolescentes: Invarianza Factorial a través del Sexo

    Directory of Open Access Journals (Sweden)

    Vanessa Arán Filippetti

    2017-09-01

    Full Text Available Los objetivos del presente estudio fueron (i analizar la estructura latente de las Funciones Ejecutivas (FE en adolescentes y (ii comprobar su invarianza factorial (i,e., configural, métrica, escalar, estructural y residual a través del sexo. Se trabajó con una muestra de 125 adolescentes de 11 a 15 años de edad de ambos sexos a los que se administró diferentes tareas de FE. Se empleó Análisis Factorial Confirmatorio (AFC y AFC Multigrupo (AFCMG. El AFC ofreció apoyo para la estructura de tres factores separados pero relacionados: (i Memoria de trabajo, (ii Flexibilidad Cognitiva y (iii Inhibición. Además, el AFCMG reveló que la estructura de tres factores es invariante a través del sexo, lo que permite la comparación entre los grupos de los componentes hallados. Finalmente, el análisis multivariado de varianza (MANOVA reveló diferencias significativas en el factor Flexibilidad Cognitiva a favor de las mujeres. Se discuten los resultados en términos de la naturaleza dimensional del constructo en adolescentes y de las diferencias de rendimiento cognitivo en función del sexo.

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

    Directory of Open Access Journals (Sweden)

    Maycos Leandro Zapata Muñoz

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Claudia Lucía Sossa Melo, MD

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Julio E. Ospina M.

    1995-01-01

    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.

  1. Síndrome de Turner y tiroiditis autoinmune Turner´s syndrome and autoimmune thyroiditis

    Directory of Open Access Journals (Sweden)

    Tamara Fernández Teruel

    2003-12-01

    Full Text Available Paciente de 13 años de edad, del sexo femenino, quien presenta los siguientes antecedentes patológicos familiares: madre que padece de hipertensión arterial, padre con úlcera péptica; sin lazos de consanguinidad entre los progenitores. Antecedentes prenatales: gestación a término de 38 semanas que corresponde al segundo embarazo, signo de menos y escaso incremento de la altura uterina. Motivo de consulta: baja talla. Al examen físico de la paciente se encuentra piel seca y áspera, panículo adiposo aumentado, cubitus valgus, teletelia, implantación baja del cabello y en tridente, así como acortamiento del cuarto metacarpiano. Glándula tiroides: aumentada de volumen ± 25 gramos, superficie lisa, no dolorosa, no se precisan nódulos. Maniobra de Chvostek negativa, no vello sexual, genitales externos de aspecto femenino y estadio I de desarrollo de mamas (Tanner I. Estudios complementarios realizados: TSH 32,6 mU/L, anticuerpos antimicrosomales positivo, anticuerpos antiislotes pancreáticos positivo, cromatina oral 12 %, FSH 68,8 UI/L (elevado, LH 12,5 UI/L (elevado, estrógenos 18 pmol/L. (disminuido, prolactina 72 mU/L (disminuido. En resumen, se trata de una paciente con diagnóstico de síndrome de Turner y enfermedad autoinmune del tiroides, que cursa con hipotiroidismo clínico.A 13-years-old female patient, who presents with the following family pathological history: mother with blood hypertension, father with peptic ulcer; no blood relationship between parents. Prenatal history: term pregnancy of 38 weeks of a second pregnancy, minus sign and little increase of uterine height. Reason for appointment: low height. On physical exam, the patient´s skin was dry and rough, augmented adipose pannicle, cubitus valgus, telethelia, low implantation of hair in trident position as well as shortening of fourth metacarpal. Thyroidal gland: increased volume of ± 25 grams, smooth surface, no pain, no nodules were detected. Negative Chvostek

  2. La variable latente calidad medida a través del modelo de Rasch.

    Directory of Open Access Journals (Sweden)

    Guerrero, Mª M.

    1997-01-01

    Full Text Available La obtención de aceites de oliva de calidad requiere unos cuidados especiales en todas y cada una de las sucesivas fases de elaboración de los mismos, es una cadena que comienza en el olivo y termina en el consumo. Condición indispensable para ello es conocer las características organolépticas del aceite (a fin de potenciar sus atributos y eliminar, en la medida de los posible, sus defectos, y la influencia del proceso de elaboración en las mismas. El control y medida de estos caracteres se hará mediante las catas, realizadas por expertos catadores utilizando para ello las fichas de cata del Consejo Oleícola Internacional. El modelo de Rasch, que emplearemos para obtener la evaluación sensorial de los aceites de oliva virgen, nos permitirá no sólo dar una calificación organoléptica global al aceite (que ya podemos realizar sin necesidad de aplicar ningún método, siguiendo la metodología de valoración del Consejo Oleícola Internacional, sino también clasificar y medir los factores sensoriales que intervienen en la calidad, lo que nos permitirá realizar las acciones oportunas encaminadas a obtener aceites de oliva de cualidades óptimas.

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

    Directory of Open Access Journals (Sweden)

    R. García Romero

    2007-05-01

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

  4. Casos estandarizados en reumatología. Enfermedades autoinmunes sistémicas

    OpenAIRE

    Nolla Solé, Joan Miquel

    2014-01-01

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

  5. Sindromes endocrinos autoinmunes: cuándo sospechar y estudiar un sindrome poliglandular (SPG)

    OpenAIRE

    B. María Carolina Letelier, Dra.

    2013-01-01

    Los síndromes poliglandulares autoinmunes comprenden un amplio espectro de trastornos endocrinos. Estos síndromes incluyen trastornos monogénicos como el síndrome poliglandular tipo 1 (tipo juvenil) y trastornos genéticos complejos como el síndrome poliglandular tipo 2 (tipo adulto). Estos trastornos se basan en la presencia de infiltración linfocitaria de la glándula afectada, anticuerpos órgano-específico en sangre, defectos en la inmunidad celular y asociación con los genes de los antígeno...

  6. Prevalencia de infección tuberculosa latente en trabajadores de salud de establecimientos del primer nivel de atención. Lima, Perú

    Directory of Open Access Journals (Sweden)

    Mirtha Gabriela Soto Cabezas

    Full Text Available RESUMEN Con el propósito de disponer de información sobre los riesgos para infección por tuberculosis, la Dirección General de Epidemiología del Ministerio de Salud, desarrolló una vigilancia centinela en establecimientos de salud de la Provincia constitucional del Callao, dicha vigilancia incluyó el diagnóstico de infección tuberculosa latente (ITL mediante la aplicación del método IGRA. El objetivo del presente estudio fue estimar la prevalencia de ITL en trabajadores de salud de un área con alta carga de enfermedad de tuberculosis. La prevalencia de ITL en trabajadores de salud fue 56%. En trabajadores con más de 10 años de servicio la prevalencia se incrementó a 63% y en trabajadores con más de 35 años de servicio se encontraron prevalencias entre 58 y 60%. Existe una alta prevalencia de ITL en trabajadores de salud de establecimientos del primer nivel de atención, identificándose al mayor tiempo de servicio, como uno de los principales factores de riesgo.

  7. "Curriculitis autoinmune": Una no tan nueva enfermedad del currículo

    OpenAIRE

    Salas,Sofía P; Sánchez D,Ignacio; Larios G,Guillermo; Jeria D,Álvaro; Pertuzé S,Cristóbal

    2009-01-01

    Thirty years ago, Abrahamson described the main curriculum problems in undergraduate medical education as "diseases of the curriculum". Based on our own experience and knowledge, we propose the inclusión of a new condition named "autoimmune curriculitis", which is produced by the students themselves. In this condition, the students are who decide to "swell" the curriculum, by excessively participating in múltiple intra and extramural activities, competing to markedly improve their academic pe...

  8. 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; M. Miquel Feucht; 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...

  9. 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.

  10. Diagnóstico y tratamiento de los síndromes de sobreposición de hepatitis autoinmune

    Directory of Open Access Journals (Sweden)

    O. Aguilar-Nájera

    2015-04-01

    En la actualidad, aún existe controversia acerca de si los síndromes de sobreposición son entidades diferentes o la presencia de 2 enfermedades coexistentes. Deben ser buscados en los pacientes con hepatitis autoinmune que tienen datos de colestasis ya que sabemos que su comportamiento tiende a ser más agresivo con mayores tasas de cirrosis y necesidad de trasplante hepático así como pobre respuesta al tratamiento, el cual debe ser dirigido al fenotipo principal. Hacen falta definiciones estandarizadas que permitan su estudio en ensayos clínicos controlados.

  11. 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.

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

    OpenAIRE

    Julio E. Ospina M.; Sandra P. Cuervo A.

    1995-01-01

    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 ...

  13. Síndrome autoinmune en la paraparesia tropical espástica/ mielopatía asociada a la infección por el virus linfotrópico humano tipo I de la costa pacífica colombiana

    Directory of Open Access Journals (Sweden)

    Felipe García

    2008-12-01

    Full Text Available Introducción. Trabajos previos han aportado evidencias de que en la paraparesia espástica tropical/mielopatía asociada con el virus linfotrópico humano tipo I, existe un componente autoinmune asociado a su patogénesis. Objetivo. Evaluar el estado autoinmune y la existencia de mimetismo molecular en pacientes con paraparesia espástica tropical del pacífico colombiano. Materiales y métodos. A partir de muestras de plasma de 37 pacientes con paraparesia espástica tropical/mielopatía asociada al HTLV-I, 10 con leucemia de células T del adulto, 22 individuos portadores asintomáticos y 20 seronegativos para el HTLV-I, se determinaron niveles plasmáticos de anticuerpos antinucleares y anticardiolipina-2 y de interferón-??e interleucina- 4. Se evaluó, por Western blot, la reactividad cruzada de plasmas contra proteínas obtenidas de varias fuentes celulares normales del sistema nervioso. Además, se estudió la reactividad cruzada de plasmas de seropositivos y del anticuerpo monoclonal LT4 anti-taxp40 en secciones de médula espinal de ratas Wistar no infectadas. Resultados. El 70,2% y el 83,8% de los pacientes con paraparesia espástica tropical fueron reactivos para anticuerpos ANA y ACL-2, respectivamente, en contraste con los de leucemia de células T del adulto y los seropositivos asintomáticos (P<0,001. Además, el 70,3% y el 43,2% de los pacientes con paraparesia espástica tropical tuvieron niveles detectables de IFN-?? e IL-4, respectivamente. El anticuerpo LT4 anti tax-p40 y los plasmas de paraparesia espástica tropical/mielopatía asociada al HTLV-I mostraron una reacción cruzada con una proteína de PMr 33-35 kDa, obtenida del núcleo de neuronas de la médula espinal de ratas Wistar no infectadas. Conclusión. Se obtuvieron evidencias que apoyan la existencia de un síndrome autoinmune mediado por mimetismo molecular como parte de la etiopatogénesis de la degeneración axonal observada en la paraparesia esp

  14. 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; S. Gimenez; P. Galarza; 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...

  15. 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

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

    Directory of Open Access Journals (Sweden)

    J. L. Beristain

    2008-10-01

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

  17. Hepatitis autoinmune en niños: evolución de 20 casos del norte de México

    Directory of Open Access Journals (Sweden)

    J. Nares-Cisneros

    2014-10-01

    Conclusiones: Es necesario sospechar la HAI en pediatría para poder realizar un diagnóstico temprano y así establecer el tratamiento oportuno. Determinar el tipo de HAI nos permitirá establecer el diagnóstico adecuado y elaborar un mejor pronóstico respecto a tasas de recaídas y complicaciones.

  18. Diseño de un plan estratégico en el Instituto de Enfermedades Autoinmunes Renato Guzmán - IDEARG S.A.S.

    OpenAIRE

    Jiménez Serrano, Lorena; Ortegon Lancheros, Carolina

    2012-01-01

    IDEARG S.A.S es una Institución Prestadora de Servicios de Salud dedicada a la atención de pacientes con enfermedades autoinmunes. Dentro de su ordenación se encuentra una planta de personal organizada y comprometida con el progreso de la empresa. Sin embargo, existe una sentida necesidad de implementar estrategias que permitan el fortalecimiento interno de la institución y su posicionamiento en el mercado como una de las empresas de mayor prestigio en su campo de acción. Resulta oportuno...

  19. Enfermedades del tejido conectivo: Importancia del diagnóstico precoz

    Directory of Open Access Journals (Sweden)

    G. Patricia Abumohor, Dra.

    2012-07-01

    Full Text Available Las Enfermedades del Tejido Conectivo (ETC son entidades de baja prevalencia en la población general. Son de naturaleza inflamatoria y autoinmune, tienden a la cronicidad y al compromiso de muchos parénquimas, órganos y tejidos, dejando en ellos daño estructural y funcional. Dado lo anterior, amenazan la vida o disminuyen la expectativa y calidad de vida. El diagnóstico y tratamiento precoz de estas entidades, permite cambiar su curso y muchas veces lograr remisión. Es por lo tanto de suma importancia tenerlas en mente y sospecharlas como entidades de enfermedad e iniciar un tratamiento oportuno.

  20. Enfermedades del tejido conectivo: Importancia del diagnóstico precoz

    OpenAIRE

    G. Patricia Abumohor, Dra.

    2012-01-01

    Las Enfermedades del Tejido Conectivo (ETC) son entidades de baja prevalencia en la población general. Son de naturaleza inflamatoria y autoinmune, tienden a la cronicidad y al compromiso de muchos parénquimas, órganos y tejidos, dejando en ellos daño estructural y funcional. Dado lo anterior, amenazan la vida o disminuyen la expectativa y calidad de vida. El diagnóstico y tratamiento precoz de estas entidades, permite cambiar su curso y muchas veces lograr remisión. Es por lo tanto de suma i...

  1. 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.

  2. Humedad de equilibrio y calor latente de vaporización del ajonjolí. sésamun indicum l.

    OpenAIRE

    Ospina M., Julio E.; Cuervo A., Sandra P.

    2011-01-01

    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 ...

  3. Latent palmprint matching.

    Science.gov (United States)

    Jain, Anil K; Feng, Jianjiang

    2009-06-01

    The evidential value of palmprints in forensic applications is clear as about 30 percent of the latents recovered from crime scenes are from palms. While biometric systems for palmprint-based personal authentication in access control type of applications have been developed, they mostly deal with low-resolution (about 100 ppi) palmprints and only perform full-to-full palmprint matching. We propose a latent-to-full palmprint matching system that is needed in forensic applications. Our system deals with palmprints captured at 500 ppi (the current standard in forensic applications) or higher resolution and uses minutiae as features to be compatible with the methodology used by latent experts. Latent palmprint matching is a challenging problem because latent prints lifted at crime scenes are of poor image quality, cover only a small area of the palm, and have a complex background. Other difficulties include a large number of minutiae in full prints (about 10 times as many as fingerprints), and the presence of many creases in latents and full prints. A robust algorithm to reliably estimate the local ridge direction and frequency in palmprints is developed. This facilitates the extraction of ridge and minutiae features even in poor quality palmprints. A fixed-length minutia descriptor, MinutiaCode, is utilized to capture distinctive information around each minutia and an alignment-based minutiae matching algorithm is used to match two palmprints. Two sets of partial palmprints (150 live-scan partial palmprints and 100 latent palmprints) are matched to a background database of 10,200 full palmprints to test the proposed system. Despite the inherent difficulty of latent-to-full palmprint matching, rank-1 recognition rates of 78.7 and 69 percent, respectively, were achieved in searching live-scan partial palmprints and latent palmprints against the background database.

  4. 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.

  5. 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....

  6. Polimorfismo del TNF-alpha en autoinmunidad y tuberculosis.

    Directory of Open Access Journals (Sweden)

    Paula A. Correa

    2004-06-01

    Full Text Available El factor de necrosis tumoral alfa (TNF-a está incriminado tanto en enfermedades autoinmunes como en infecciosas. En el presente estudio se examinó el polimorfismo de la región promotora -308 del gen del TNF-a en enfermedades autoinmunes [lupus eritematoso sistémico (LES, artritis reumatoidea (AR, síndrome de Sjögren primario (SSp] y en tuberculosis. La genotipificación del polimorfismo -308 del TNF-a se realizó en ADN de pacientes con AR (N=165, LES (N=118, SSp (N=67, tuberculosis (N=138 y controles sanos (N=419, mediante reacción en cadena de la polimerasa con polimorfismos en los tamaños de los fragmentos de restricción (PCR-RFLP. El alelo TNF2 se asoció con la AR (OR=1,6; IC95% 1,2-2,3, p=0,008, el LES (OR=2,3; IC95% 1,6-3,3, p

  7. VACUNACIÓN CONTRA EL VIRUS DEL PAPILOMA HUMANO Y AUTOINMUNIDAD

    Directory of Open Access Journals (Sweden)

    Juan-Manuel Anaya

    2014-10-01

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

  8. 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...

  9. Papel de hemo oxigensa-1 en la artritis inducida por transferencia de suero K/BxN. Caracterización del modelo experimental

    OpenAIRE

    Brines Juan, Rita

    2017-01-01

    La Artritis Reumatoide (AR) es una enfermedad sistémica, crónica y de carácter autoinmune que produce daño articular en los pacientes. Cursa con la degradación del hueso subcondral y del cartílago articular causando un gran dolor; además de ser una enfermedad incapacitante, puede provocar síntomas extraarticulares que afecten a otros órganos. El estudio de la patogenia y del tratamiento de la AR se desarrolla en gran medida sobre modelos animales de artritis experimental. En la actualidad...

  10. Latent semantic analysis.

    Science.gov (United States)

    Evangelopoulos, Nicholas E

    2013-11-01

    This article reviews latent semantic analysis (LSA), a theory of meaning as well as a method for extracting that meaning from passages of text, based on statistical computations over a collection of documents. LSA as a theory of meaning defines a latent semantic space where documents and individual words are represented as vectors. LSA as a computational technique uses linear algebra to extract dimensions that represent that space. This representation enables the computation of similarity among terms and documents, categorization of terms and documents, and summarization of large collections of documents using automated procedures that mimic the way humans perform similar cognitive tasks. We present some technical details, various illustrative examples, and discuss a number of applications from linguistics, psychology, cognitive science, education, information science, and analysis of textual data in general. WIREs Cogn Sci 2013, 4:683-692. doi: 10.1002/wcs.1254 CONFLICT OF INTEREST: The author has declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website. © 2013 John Wiley & Sons, Ltd.

  11. Latent heat coldness storage; Stockage du froid par chaleur latente

    Energy Technology Data Exchange (ETDEWEB)

    Dumas, J.P. [Pau Univ., Lab. de Thermodynamique et Energetique, LTE, 64 (France)

    2002-07-01

    This article presents the advantages of latent heat storage systems which use the solid-liquid phase transformation of a pure substance or of a solution. The three main methods of latent heat storage of coldness are presented: ice boxes, encapsulated nodules, and ice flows: 1 - definition of the thermal energy storage (sensible heat, latent heat, thermochemical storage); 2 - advantages and drawbacks of latent heat storage; 3 - choice criteria for a phase-change material; 4 - phenomenological aspect of liquid-solid transformations (phase equilibrium, crystallisation and surfusion); 5 - different latent heat storage processes (ice boxes, encapsulated nodules, two-phase refrigerating fluids); 6 - ice boxes (internal and external melting, loop, air injection, measurement of ice thickness); 7 - encapsulated nodules (nodules, tank, drainage, advantage and drawbacks, charge and discharge); 8 - two-phase refrigerating fluids (composition, ice fabrication, flow circulation, flow storage, exchangers). (J.S.)

  12. Hepatitis inmune temprana en el curso del síndrome de Sjögren en pediatría

    OpenAIRE

    Baar Z., Alejandro; Harris D., Paul; Talesnik G., Eduardo; Duarte G. de C., Ignacio

    1999-01-01

    La hepatitis inmune corresponde a una enfermedad necroinflamatoria del hígado, de causa desconocida, asociada a la presencia de autoanticuerpos circulantes. Puede presentarse aisladamente, o en asociación a otras enfermedades autoinmunes. Entre estas, destaca el síndrome de Sjögren, que compromete preferentemente a las glándulas salivales, aunque puede afectar a cualquier segmento del tubo digestivo, especialmente el hígado. Reportamos el caso de una niña de 12 años de edad, portadora de Sínd...

  13. AUTOINMUNIDAD NEUROLÓGICA EN LOS TIEMPOS DEL ZIKA

    Directory of Open Access Journals (Sweden)

    Yeny Acosta-Ampudia

    2016-06-01

    Full Text Available

    Desde el año 2015 el mundo se vio enfrentado al renacer de una nueva epidemia por el virus del Zika (vZIKA, cuyas complicaciones neurológicas hicieron que en Febrero de 2016 la Organización Mundial de la Salud declarara la epidemia como una “emergencia de salud pública de importancia internacional”. En el presente artículo se revisan las características de este virus y su asociación con el síndrome de Guillain-Barré, a través de una posible respuesta autoinmune contra gangliósidos mediante mimetismo molecular, en el contexto de la ecología autoinmune.

    NEUROLOGICAL AUTOIMMUNITY IN THE TIME OF ZIKA

    ABSTRACT

    Since 2015 the world is facing a new outbreak of Zika virus (ZIKV. The sudden increase in neurological complications associated with ZIKV prompted the World Health Organization to declare this outbreak in February 2016 a “public health emergency of international concern”. This article reviews the main characteristics of ZIKV and its association with Guillain-Barre syndrome, in the context of autoimmune ecology, through a possible molecular mimicry against gangliosides.

  14. Longitudinal Research with Latent Variables

    CERN Document Server

    van Montfort, Kees; Satorra, Albert

    2010-01-01

    This book combines longitudinal research and latent variable research, i.e. it explains how longitudinal studies with objectives formulated in terms of latent variables should be carried out, with an emphasis on detailing how the methods are applied. Because longitudinal research with latent variables currently utilizes different approaches with different histories, different types of research questions, and different computer programs to perform the analysis, the book is divided into nine chapters. Starting from some background information about the specific approach, short history and the ma

  15. Latent geometry of bipartite networks

    Science.gov (United States)

    Kitsak, Maksim; Papadopoulos, Fragkiskos; Krioukov, Dmitri

    2017-03-01

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

  16. Enfermedad celiaca en niños del noroeste de México: características clínicas de 24 casos

    OpenAIRE

    N. Sotelo Cruz; A.M. Calderón de la Barca; J.G. Hurtado Valenzuela

    2013-01-01

    Antecedentes: La enfermedad celiaca (EC) es una enteropatía autoinmune inducida por el gluten del trigo dietético, con serias consecuencias si no se diagnostica y trata tempranamente. Hay además otras alteraciones asociadas a la ingestión de gluten, que es importante conocer, por su multiplicidad de presentaciones clínicas. Objetivos: Describir los patrones más comunes de presentación de EC y alteraciones asociadas al gluten en niños de la región noroeste de México, con incipiente conocimi...

  17. 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....

  18. Noves tècniques per a la detecció de la tuberculosi latent

    OpenAIRE

    Rivas, Inmaculada

    2010-01-01

    Espanya és un dels països industrialitzats amb major índex de tuberculosi, especialment entre els afectats pel VIH i les persones drogodependents, però la infecció acostuma a romandre latent en la majoria dels casos. La prova in vivo tradicional, coneguda com a PPD, consisteix en un test cutani que pot donar falsos positius o falsos negatius. Aquest estudi ha diagnosticat tuberculosi latent gràcies a dos nous mètodes in vitro, entre la població drogodependent de l'àrea metropolitana de Barcel...

  19. Latent class models for classification

    NARCIS (Netherlands)

    Vermunt, J.K.; Magidson, J.

    2003-01-01

    An overview is provided of recent developments in the use of latent class (LC) and other types of finite mixture models for classification purposes. Several extensions of existing models are presented. Two basic types of LC models for classification are defined: supervised and unsupervised

  20. Treatment of Latent Tuberculosis Infection

    OpenAIRE

    Tang, Patrick; Johnston, James

    2017-01-01

    Opinion statement The treatment of latent tuberculosis infection (LTBI) is an essential component of tuberculosis (TB) elimination in regions that have a low incidence of TB. However, the decision to treat individuals with LTBI must consider the limitations of current diagnostic tests for LTBI, the risk of developing active TB disease, the potential adverse effects from chemoprophylactic therapy, and the importance of treatment adherence. When an individual has been diagnosed with LTBI and ac...

  1. Effect of stimulus intensity on latent inhibition: A case for generalization decrement

    Directory of Open Access Journals (Sweden)

    Gabriel Rodríguez

    2002-01-01

    Full Text Available En dos experimentos se empleó la técnica de aversión condicionada al sabor en ratas para examinar el efecto de la intensidad del estímulo expuesto sobre la inhibición latente. En el Experimento 1 se valoró el efecto de la exposición de un sabor dulce en distintas concentraciones sobre la tasa de adquisición de su condicionamiento posterior. Los resultados de este experimento mostraron un mayor efecto de inhibición latente tras la exposición del sabor en igual concentración a la empleada durante el condicionamiento (grupo EI que tras su exposición en una concentración mayor (grupo EM o menor (grupo Em. Además, esta atenuación del efecto de inhibición latente en las condiciones de cambio en la concentración resultó menor en el grupo EM que en el grupo Em. El Experimento 2 demostró que la generalización de las propiedades aversivas condicionadas al sabor fue mayor entre las concentraciones empleadas en el grupo EM que en el grupo Em. Estos resultados sugieren que el aparente efecto de la intensidad del estímulo en la inhibición latente podría ser explicado en términos de decremento en la generalización.

  2. Latent semantics as cognitive components

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  3. The Latent Structure of Autistic Traits: A Taxometric, Latent Class and Latent Profile Analysis of the Adult Autism Spectrum Quotient

    Science.gov (United States)

    James, Richard J.; Dubey, Indu; Smith, Danielle; Ropar, Danielle; Tunney, Richard J.

    2016-01-01

    Autistic traits are widely thought to operate along a continuum. A taxometric analysis of Adult Autism Spectrum Quotient data was conducted to test this assumption, finding little support but identifying a high severity taxon. To understand this further, latent class and latent profile models were estimated that indicated the presence of six…

  4. Latent variable models are network models.

    Science.gov (United States)

    Molenaar, Peter C M

    2010-06-01

    Cramer et al. present an original and interesting network perspective on comorbidity and contrast this perspective with a more traditional interpretation of comorbidity in terms of latent variable theory. My commentary focuses on the relationship between the two perspectives; that is, it aims to qualify the presumed contrast between interpretations in terms of networks and latent variables.

  5. Learning Latent Vector Spaces for Product Search

    NARCIS (Netherlands)

    Van Gysel, C.; de Rijke, M.; Kanoulas, E.

    2016-01-01

    We introduce a novel latent vector space model that jointly learns the latent representations of words, e-commerce products and a mapping between the two without the need for explicit annotations. The power of the model lies in its ability to directly model the discriminative relation between

  6. Plutonium and latent nuclear proliferation

    International Nuclear Information System (INIS)

    Quester, G.H.

    1992-01-01

    A country producing nuclear electric power acquires an ability to produce atomic bombs quite easily and without taking many steps beyond that which would be perfectly normal for civilian purposes. The role of plutonium in the three fold list of the gains that must be sought in arms control formulated by Schelling and Halpevin are discussed. On the first, that we should seek to reduce the likelihood of war, it can be argued that plutonium reduces the likelihood in some cases. The second, that we should seek to reduce the destruction in war, is made worse by plutonium. On the third criterion, that we should seek to reduce the burdens in peacetime of everyone's being prepared for war, the situation is confusing and depends on the prospects for nuclear electrical power. It is concluded that latent capability to produce nuclear weapons may be sufficient without the need for actual detonations and deployment of bombs. (UK)

  7. Homosexualidad latente en el cine

    OpenAIRE

    Sánchez del Pulgar Legido, Rosa Mª

    2015-01-01

    Desde el principio del siglo XX en los Estados Unidos y Europa, las personas vivían su homosexualidad a escondidas por temor a las leyes que la castigaban; el cine pues, les representa del mismo modo creando una subcultura en la que pueden ser ellos mismos. La cinematografía clásica y los años posteriores se componen de numerosos filmes cargados de representaciones homosexuales de manera oculta. Interpretados desde una lectura queer, conoceremos las mil maneras de sugerir a los gais y a las l...

  8. Stability of latent class segments over time

    DEFF Research Database (Denmark)

    Mueller, Simone

    2011-01-01

    Dynamic stability, as the degree to which identified segments at a given time remain unchanged over time in terms of number, size and profile, is a desirable segment property which has received limited attention so far. This study addresses the question to what degree latent classes identified from...... logit model suggests significant changes in the price sensitivity and the utility from environmental claims between both experimental waves. A pooled scale adjusted latent class model is estimated jointly over both waves and the relative size of latent classes is compared across waves, resulting...... 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...

  9. Latent lifestyle preferences and household location decisions

    Science.gov (United States)

    Walker, Joan L.; Li, Jieping

    2007-04-01

    Lifestyle, indicating preferences towards a particular way of living, is a key driver of the decision of where to live. We employ latent class choice models to represent this behavior, where the latent classes are the lifestyles and the choice model is the choice of residential location. Thus, we simultaneously estimate lifestyle groups and how lifestyle impacts location decisions. Empirical results indicate three latent lifestyle segments: suburban dwellers, urban dwellers, and transit-riders. The suggested lifestyle segments have intriguing policy implications. Lifecycle characteristics are used to predict lifestyle preferences, although there remain significant aspects that cannot be explained by observable variables.

  10. Extraction of latent images from printed media

    Science.gov (United States)

    Sergeyev, Vladislav; Fedoseev, Victor

    2015-12-01

    In this paper we propose an automatic technology for extraction of latent images from printed media such as documents, banknotes, financial securities, etc. This technology includes image processing by adaptively constructed Gabor filter bank for obtaining feature images, as well as subsequent stages of feature selection, grouping and multicomponent segmentation. The main advantage of the proposed technique is versatility: it allows to extract latent images made by different texture variations. Experimental results showing performance of the method over another known system for latent image extraction are given.

  11. Bayesian Latent Class Analysis Tutorial.

    Science.gov (United States)

    Li, Yuelin; Lord-Bessen, Jennifer; Shiyko, Mariya; Loeb, Rebecca

    2018-01-01

    This article is a how-to guide on Bayesian computation using Gibbs sampling, demonstrated in the context of Latent Class Analysis (LCA). It is written for students in quantitative psychology or related fields who have a working knowledge of Bayes Theorem and conditional probability and have experience in writing computer programs in the statistical language R . The overall goals are to provide an accessible and self-contained tutorial, along with a practical computation tool. We begin with how Bayesian computation is typically described in academic articles. Technical difficulties are addressed by a hypothetical, worked-out example. We show how Bayesian computation can be broken down into a series of simpler calculations, which can then be assembled together to complete a computationally more complex model. The details are described much more explicitly than what is typically available in elementary introductions to Bayesian modeling so that readers are not overwhelmed by the mathematics. Moreover, the provided computer program shows how Bayesian LCA can be implemented with relative ease. The computer program is then applied in a large, real-world data set and explained line-by-line. We outline the general steps in how to extend these considerations to other methodological applications. We conclude with suggestions for further readings.

  12. OTROS TIPOS ESPECÍFICOS DE DIABETES MELLITUS

    Directory of Open Access Journals (Sweden)

    DRA. M. Gabriela Sanzana G.

    2016-03-01

    En las “Diabetes Atípicas” (no incluidas en la clasificación ADA, se mencionan la DM tipo 2 en niños y adolescentes, favorecida por el aumento de la obesidad y del sedentarismo; la diabetes propensa a la cetosis, que debutan en cetoacidosis, con etiopatogenia y evolución de DM2; los Latent Autoinmune Diabetes of Adults (LADA, DM tipo 1 de lenta aparición y la diabetes postrasplante.

  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.

  14. Latent Heat Storage Through Phase Change Materials

    Indian Academy of Sciences (India)

    IAS Admin

    reducing storage volume for different materials. The examples are numerous: ... Latent heat is an attractive way to store solar heat as it provides high energy storage density, .... Maintenance of the PCM treated fabric is easy. The melted PCM.

  15. New Treatment Regimen for Latent Tuberculosis Infection

    Centers for Disease Control (CDC) Podcasts

    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.

  16. Latent variables and route choice behavior

    DEFF Research Database (Denmark)

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

    2012-01-01

    In the last decade, a broad array of disciplines has shown a general interest in enhancing discrete choice models by considering the incorporation of psychological factors affecting decision making. This paper provides insight into the comprehension of the determinants of route choice behavior...... 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...

  17. UNSOLVED AND LATENT CRIME: DIFFERENCES AND SIMILARITIES

    Directory of Open Access Journals (Sweden)

    Mikhail Kleymenov

    2017-01-01

    Full Text Available УДК 343Purpose of the article is to study the specific legal and informational nature of the unsolved crime in comparison with the phenomenon of delinquency, special study and analysis to improve the efficiency of law enforcement.Methods of research are abstract-logical, systematic, statistical, study of documents. The main results of research. Unsolved crime has specific legal, statistical and informational na-ture as the crime phenomenon, which is expressed in cumulative statistical population of unsolved crimes. An array of unsolved crimes is the sum of the number of acts, things of which is suspended and not terminated. The fault of the perpetrator in these cases is not proven, they are not considered by the court, it is not a conviction. Unsolved crime must be registered. Latent crime has a different informational nature. The main symptom of latent crimes is the uncertainty for the subjects of law enforcement, which delegated functions of identification, registration and accounting. Latent crime is not recorded. At the same time, there is a "border" area between the latent and unsolved crimes, which includes covered from the account of the crime. In modern Russia the majority of crimes covered from accounting by passing the decision about refusal in excitation of criminal case. Unsolved crime on their criminogenic consequences represents a significant danger to the public is higher compared to latent crime.It is conducted in the article a special analysis of the differences and similarities in the unsolved latent crime for the first time in criminological literature.The analysis proves the need for radical changes in the current Russian assessment of the state of crime and law enforcement to solve crimes. The article argues that an unsolved crime is a separate and, in contrast to latent crime, poorly understood phenomenon. However unsolved latent crime and have common features and areas of interaction.

  18. Exposing Latent Information in Folksonomies for Reasoning

    Science.gov (United States)

    2010-01-14

    1.73 $.") http://www.w3.org/2006/07/SWD/ SKOS /reference/20081001/ Spiteri, L.F. (2007) "The structure and form of folksonomy tags: The road to the...Exposing Latent Information in Folksonomies for Reasoning January 14, 2010 Sponsored by Defense Advanced Research Projects Agency (DOD...DATES COVERED (From - To! 4/14/2009-12/23/2009 4. TITLE AND SUBTITLE Exposing Latent Information in Folksonomies for Reasoning Sa. CONTRACT

  19. 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.

  20. The Latent Structure of Dictionaries.

    Science.gov (United States)

    Vincent-Lamarre, Philippe; Massé, Alexandre Blondin; Lopes, Marcos; Lord, Mélanie; Marcotte, Odile; Harnad, Stevan

    2016-07-01

    How many words-and which ones-are sufficient to define all other words? When dictionaries are analyzed as directed graphs with links from defining words to defined words, they reveal a latent structure. Recursively removing all words that are reachable by definition but that do not define any further words reduces the dictionary to a Kernel of about 10% of its size. This is still not the smallest number of words that can define all the rest. About 75% of the Kernel turns out to be its Core, a "Strongly Connected Subset" of words with a definitional path to and from any pair of its words and no word's definition depending on a word outside the set. But the Core cannot define all the rest of the dictionary. The 25% of the Kernel surrounding the Core consists of small strongly connected subsets of words: the Satellites. The size of the smallest set of words that can define all the rest-the graph's "minimum feedback vertex set" or MinSet-is about 1% of the dictionary, about 15% of the Kernel, and part-Core/part-Satellite. But every dictionary has a huge number of MinSets. The Core words are learned earlier, more frequent, and less concrete than the Satellites, which are in turn learned earlier, more frequent, but more concrete than the rest of the Dictionary. In principle, only one MinSet's words would need to be grounded through the sensorimotor capacity to recognize and categorize their referents. In a dual-code sensorimotor/symbolic model of the mental lexicon, the symbolic code could do all the rest through recombinatory definition. Copyright © 2016 Cognitive Science Society, Inc.

  1. 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.

  2. Latent-Trait Latent-Class Analysis of Self-disclosure in the Work Environment

    NARCIS (Netherlands)

    Maij - de Meij, A.M.; Kelderman, H.; van der Flier, H.

    2005-01-01

    Based on the literature about self-disclosure, it was hypothesized that different groups of subjects differ in their pattern of self-disclosure with respect to different areas of social interaction. An extended latent-trait latent-class model was proposed to describe these general patterns of

  3. Latent-trait latent-class analysis of selfdisclosure in the work environment

    NARCIS (Netherlands)

    Maij - de Meij, A.M.; Kelderman, H.; van der Flier, H.

    2006-01-01

    Based on the literature about self-disclosure, it was hypothesized that different groups of subjects differ in their pattern of self-disclosure with respect to different areas of social interaction. An extended latent-trait latent-class model was proposed to describe these general patterns of

  4. Latent-Trait Latent-Class Analysis of Self-Disclosure in the Work Environment

    Science.gov (United States)

    Maij-de Meij, Annette M.; Kelderman, Henk; van der Flier, Henk

    2005-01-01

    Based on the literature about self-disclosure, it was hypothesized that different groups of subjects differ in their pattern of self-disclosure with respect to different areas of social interaction. An extended latent-trait latent-class model was proposed to describe these general patterns of self-disclosure. The model was used to analyze the data…

  5. Latent-trait latent-class analysis of selfdisclosure in the work environment

    NARCIS (Netherlands)

    Maij - de Meij, A.M.; Kelderman, H.; van der Flier, H.

    2005-01-01

    Based on the literature about self-disclosure, it was hypothesized that different groups of subjects differ in their pattern of self-disclosure with respect to different areas of social interaction. An extended latent-trait latent-class model was proposed to describe these general patterns of

  6. Uso del Propanolol en Hipertiroidismo

    Directory of Open Access Journals (Sweden)

    Alfredo Jácome Roca

    1993-08-01

    Full Text Available

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

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

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

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

    Muchas de

  7. Latent Growth and Dynamic Structural Equation Models.

    Science.gov (United States)

    Grimm, Kevin J; Ram, Nilam

    2018-05-07

    Latent growth models make up a class of methods to study within-person change-how it progresses, how it differs across individuals, what are its determinants, and what are its consequences. Latent growth methods have been applied in many domains to examine average and differential responses to interventions and treatments. In this review, we introduce the growth modeling approach to studying change by presenting different models of change and interpretations of their model parameters. We then apply these methods to examining sex differences in the development of binge drinking behavior through adolescence and into adulthood. Advances in growth modeling methods are then discussed and include inherently nonlinear growth models, derivative specification of growth models, and latent change score models to study stochastic change processes. We conclude with relevant design issues of longitudinal studies and considerations for the analysis of longitudinal data.

  8. Learning Latent Structure in Complex Networks

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai

    such as the Modularity, it has recently been shown that latent structure in complex networks is learnable by Bayesian generative link distribution models (Airoldi et al., 2008, Hofman and Wiggins, 2008). In this paper we propose a new generative model that allows representation of latent community structure......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...... as in the previous Bayesian approaches and in addition allows learning of node specific link properties similar to that in the modularity objective. We employ a new relaxation method for efficient inference in these generative models that allows us to learn the behavior of very large networks. We compare the link...

  9. A Multinomial Probit Model with Latent Factors

    DEFF Research Database (Denmark)

    Piatek, Rémi; Gensowski, Miriam

    2017-01-01

    be meaningfully linked to an economic model. We provide sufficient conditions that make this structure identified and interpretable. For inference, we design a Markov chain Monte Carlo sampler based on marginal data augmentation. A simulation exercise shows the good numerical performance of our sampler......We develop a parametrization of the multinomial probit model that yields greater insight into the underlying decision-making process, by decomposing the error terms of the utilities into latent factors and noise. The latent factors are identified without a measurement system, and they can...

  10. Especies reactivas del oxígeno y balance redox, parte I: aspectos básicos y principales especies reactivas del oxígeno Oxygen reactive species and redox balance, part I: basic aspects and main oxygen reactive species

    Directory of Open Access Journals (Sweden)

    Gregorio Martínez Sánchez

    2005-12-01

    Full Text Available El balance redox ha sido reconocido, de forma cada vez más creciente, como un componente crítico del proceso de envejecimiento; la iniciación y desarrollo de enfermedades de notable morbilidad y mortalidad (aterosclerosis, cáncer, enfermedades del sistema nervioso central, enfermedades autoinmunes, daño por isquemia-reperfusión, entre otras y respuestas celulares, inducidas por el estrés oxidativo. Estrechamente vinculado con el estrés oxidativo está la generación de especies reactivas de oxígeno las cuales provocan daño celular directo, además de actuar como segundos mensajeros intracelulares al modular las vías de transducción de señales. En el presente trabajo se recogen los principales antecedentes de las investigaciones relacionadas con este tema y se describen las más importantes características de las especies reactivas del oxígeno.The redox balance has been increasingly recognized as a critical component of the aging process; the onset and development of diseases causing dramatic morbidity and mortality (atherosclerosis, cancer, central nervous system diseases, autoinmune diseases, ischemia-reperfusion damage, among others and oxidative stress-induced cellular responses. Closely related to oxidative stress is the generation of oxygen reactive species, which cause direct cell damage in addition to acting as second intracellular messengers when modulating signal transduction pathways. The present paper presented the main antecedents of pieces of research related to this topic and described the most important characteristics of the oxygen reactive species.

  11. Internet en las elecciones del 2003

    OpenAIRE

    Delia Crovi Druetta

    2004-01-01

    La importancia de Internet como recurso para la comunicación política, se hizo latente por primera vez en una contienda electoral en México. El propósito de este trabajo es analizar los alcances y límites de esta tecnología, en el contexto del reciente proceso electoral de 2003.

  12. Variable importance in latent variable regression models

    NARCIS (Netherlands)

    Kvalheim, O.M.; Arneberg, R.; Bleie, O.; Rajalahti, T.; Smilde, A.K.; Westerhuis, J.A.

    2014-01-01

    The quality and practical usefulness of a regression model are a function of both interpretability and prediction performance. This work presents some new graphical tools for improved interpretation of latent variable regression models that can also assist in improved algorithms for variable

  13. Detection of latent prints by Raman imaging

    Science.gov (United States)

    Lewis, Linda Anne [Andersonville, TN; Connatser, Raynella Magdalene [Knoxville, TN; Lewis, Sr., Samuel Arthur

    2011-01-11

    The present invention relates to a method for detecting a print on a surface, the method comprising: (a) contacting the print with a Raman surface-enhancing agent to produce a Raman-enhanced print; and (b) detecting the Raman-enhanced print using a Raman spectroscopic method. The invention is particularly directed to the imaging of latent fingerprints.

  14. Statistical inference based on latent ability estimates

    NARCIS (Netherlands)

    Hoijtink, H.J.A.; Boomsma, A.

    The quality of approximations to first and second order moments (e.g., statistics like means, variances, regression coefficients) based on latent ability estimates is being discussed. The ability estimates are obtained using either the Rasch, oi the two-parameter logistic model. Straightforward use

  15. 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…

  16. 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…

  17. 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 of chr...

  18. 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,

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

    CERN Document Server

    Skrondal, Anders; Rabe-Hesketh, Sophia

    2004-01-01

    This book unifies and extends latent variable models, including multilevel or generalized linear mixed models, longitudinal or panel models, item response or factor models, latent class or finite mixture models, and structural equation models.

  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…

  1. Latent factors and route choice behaviour

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo

    . A reliable dataset was prepared through measures of internal consistency and sampling adequacy, and data were analyzed with a proper application of factor analysis to the route choice context. For the dataset obtained from the survey, six latent constructs affecting driver behaviour were extracted and scores...... on each factor for each survey participant were calculated. Path generation algorithms were examined with respect to observed behaviour, through a measure of reproduction with deterministic techniques of the routes indicated in the answers to the survey. Results presented evidence that the majority...... 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...

  2. Latent class models in financial data analysis

    Directory of Open Access Journals (Sweden)

    Attilio Gardini

    2007-10-01

    Full Text Available This paper deals with optimal international portfolio choice by developing a latent class approach based on the distinction between international and non-international investors. On the basis of micro data, we analyze the effects of many social, demographic, economic and financial characteristics on the probability to be an international investor. Traditional measures of equity home bias do not allow for the existence of international investment rationing operators. On the contrary, by resorting to latent class analysis it is possible to detect the unobservable distinction between international investors and investors who are precluded from operating into international financial markets and, therefore, to evaluate the role of these unobservable constraints on equity home bias.

  3. Seguimiento multidisciplinario en el control del penfigoide de membranas mucosas

    Directory of Open Access Journals (Sweden)

    Fabiano Jeremias

    2011-06-01

    Full Text Available El término penfigoide de membranas mucosas designa un grupo de enfermedades vesículo-bulosas autoinmunes crónicas, que afectan predominantemente mucosas. El presente artículo describe dos casos clínicos de penfigoide de membranas mucosas con compromiso gingival y tuvo como objetivo resaltar la importancia de un correcto diagnóstico de la lesión y discutir la conducta terapéutica. Fueron realizados diversos exámenes complementares como, examen de Nikolsky, biopsia incisional, investigación de células LE y de anticuerpos antinucleares, además de la evaluación de médicos especializados en dermatología y oftalmología. Fue fundamental la substitución de dentífricos, la orientación nutricional y psicológica, el cuidado con la higiene, además del uso de corticoides tópicos. Hubo periodos de remisión y exacerbación del cuadro clínico durante el seguimiento, fue necesario el ajuste en la terapéutica y refuerzo en los cuidados con la higiene bucal. Es muy importante la interacción multidisciplinaria en la atención de estos casos para el control del tratamiento y seguimiento, además de reforzar todas las orientaciones y cuidados en lo que se refiere a la salud bucal y cautela en el uso de corticoides.

  4. Exploring galaxy evolution with latent space walks

    Science.gov (United States)

    Schawinski, Kevin; Turp, Dennis; Zhang, Ce

    2018-01-01

    We present a new approach using artificial intelligence to perform data-driven forward models of astrophysical phenomena. We describe how a variational autoencoder can be used to encode galaxies to latent space, independently manipulate properties such as the specific star formation rate, and return it to real space. Such transformations can be used for forward modeling phenomena using data as the only constraints. We demonstrate the utility of this approach using the question of the quenching of star formation in galaxies.

  5. 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.

  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. Mental toughness latent profiles in endurance athletes.

    Directory of Open Access Journals (Sweden)

    Joanna S Zeiger

    Full Text Available Mental toughness in endurance athletes, while an important factor for success, has been scarcely studied. An online survey was used to examine eight mental toughness factors in endurance athletes. The study aim was to determine mental toughness profiles via latent profile analysis in endurance athletes and whether associations exist between the latent profiles and demographics and sports characteristics. Endurance athletes >18 years of age were recruited via social media outlets (n = 1245, 53% female. Mental toughness was measured using the Sports Mental Toughness Questionnaire (SMTQ, Psychological Performance Inventory-Alternative (PPI-A, and self-esteem was measured using the Rosenberg Self-Esteem Scale (RSE. A three-class solution emerged, designated as high mental toughness (High MT, moderate mental toughness (Moderate MT and low mental toughness (Low MT. ANOVA tests showed significant differences between all three classes on all 8 factors derived from the SMTQ, PPI-A and the RSE. There was an increased odds of being in the High MT class compared to the Low MT class for males (OR = 1.99; 95% CI, 1.39, 2.83; P<0.001, athletes who were over 55 compared to those who were 18-34 (OR = 2.52; 95% CI, 1.37, 4.62; P<0.01, high sports satisfaction (OR = 8.17; 95% CI, 5.63, 11.87; P<0.001, and high division placement (OR = 2.18; 95% CI, 1.46,3.26; P<0.001. The data showed that mental toughness latent profiles exist in endurance athletes. High MT is associated with demographics and sports characteristics. Mental toughness screening in athletes may help direct practitioners with mental skills training.

  8. 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...

  9. Peces del Noroeste del Ecuador

    OpenAIRE

    Barriga, Ramiro

    1994-01-01

    La ictiofauna del occidente del Ecuador es poco conocida. Los peces del noroccidente son diferentes a los del suroccidente del Ecuador. 34 familias y 82 especies fueron colectadas que equivale al 11 % de las especies de peces continentales registradas en el Ecuador. Icteogeográficamente se sabe que la costa ecuatoriana posee dos provincias: la del Pacifico Norte y la del Guayas, se determinó que el límite de las dos provincias es el río Santiago ya que las especies del mencionado río so...

  10. Aspects of physicochemical methods for the detection of latent fingerprints

    International Nuclear Information System (INIS)

    Knowles, A.M.

    1978-01-01

    This paper reviews physicochemical methods of detecting latent finger-prints on a wide range of materials commonly found at the scene of a crime, with particular emphasis placed on the newer autoradiographic techniques. This is set against a description of studies on the fundamental nature of the latent fingerprint and its host substrate, with a brief review of the history of reagents used in latent fingerprint examination. (author)

  11. 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.

  12. Mental toughness latent profiles in endurance athletes.

    Science.gov (United States)

    Zeiger, Joanna S; Zeiger, Robert S

    2018-01-01

    Mental toughness in endurance athletes, while an important factor for success, has been scarcely studied. An online survey was used to examine eight mental toughness factors in endurance athletes. The study aim was to determine mental toughness profiles via latent profile analysis in endurance athletes and whether associations exist between the latent profiles and demographics and sports characteristics. Endurance athletes >18 years of age were recruited via social media outlets (n = 1245, 53% female). Mental toughness was measured using the Sports Mental Toughness Questionnaire (SMTQ), Psychological Performance Inventory-Alternative (PPI-A), and self-esteem was measured using the Rosenberg Self-Esteem Scale (RSE). A three-class solution emerged, designated as high mental toughness (High MT), moderate mental toughness (Moderate MT) and low mental toughness (Low MT). ANOVA tests showed significant differences between all three classes on all 8 factors derived from the SMTQ, PPI-A and the RSE. There was an increased odds of being in the High MT class compared to the Low MT class for males (OR = 1.99; 95% CI, 1.39, 2.83; Pathletes who were over 55 compared to those who were 18-34 (OR = 2.52; 95% CI, 1.37, 4.62; Pathletes. High MT is associated with demographics and sports characteristics. Mental toughness screening in athletes may help direct practitioners with mental skills training.

  13. Latent heat of traffic moving from rest

    Science.gov (United States)

    Farzad Ahmadi, S.; Berrier, Austin S.; Doty, William M.; Greer, Pat G.; Habibi, Mohammad; Morgan, Hunter A.; Waterman, Josam H. C.; Abaid, Nicole; Boreyko, Jonathan B.

    2017-11-01

    Contrary to traditional thinking and driver intuition, here we show that there is no benefit to ground vehicles increasing their packing density at stoppages. By systematically controlling the packing density of vehicles queued at a traffic light on a Smart Road, drone footage revealed that the benefit of an initial increase in displacement for close-packed vehicles is completely offset by the lag time inherent to changing back into a ‘liquid phase’ when flow resumes. This lag is analogous to the thermodynamic concept of the latent heat of fusion, as the ‘temperature’ (kinetic energy) of the vehicles cannot increase until the traffic ‘melts’ into the liquid phase. These findings suggest that in situations where gridlock is not an issue, drivers should not decrease their spacing during stoppages in order to lessen the likelihood of collisions with no loss in flow efficiency. In contrast, motion capture experiments of a line of people walking from rest showed higher flow efficiency with increased packing densities, indicating that the importance of latent heat becomes trivial for slower moving systems.

  14. 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…

  15. 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…

  16. 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…

  17. Prevalence and risk factors of latent Tuberculosis among ...

    African Journals Online (AJOL)

    Background: Latent Tuberculosis treatment is a key tuberculosis control intervention. Adolescents are a high risk group that is not routinely treated in low income countries. Knowledge of latent Tuberculosis (TB) burden among adolescents may influence policy. Objectives: We determined the prevalence and risk factors of ...

  18. 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…

  19. Tweets clustering using latent semantic analysis

    Science.gov (United States)

    Rasidi, Norsuhaili Mahamed; Bakar, Sakhinah Abu; Razak, Fatimah Abdul

    2017-04-01

    Social media are becoming overloaded with information due to the increasing number of information feeds. Unlike other social media, Twitter users are allowed to broadcast a short message called as `tweet". In this study, we extract tweets related to MH370 for certain of time. In this paper, we present overview of our approach for tweets clustering to analyze the users' responses toward tragedy of MH370. The tweets were clustered based on the frequency of terms obtained from the classification process. The method we used for the text classification is Latent Semantic Analysis. As a result, there are two types of tweets that response to MH370 tragedy which is emotional and non-emotional. We show some of our initial results to demonstrate the effectiveness of our approach.

  20. Iron appetite and latent learning in rats.

    Science.gov (United States)

    Woods, S C; Vasselli, J R; Milam, K M

    1977-11-01

    Two experiments are reported which show that rats are capable of forming an association between the presence of iron in a solution when it is not specifically needed and a subsequent state of iron deficiency. Specifically, rats were trained to lever press for water while thirsty. One group received ferrous ions in addition to the water. When these rats were subsequently rendered iron deficient, they lever pressed more under extinction conditions as a graded function of lower hemoglobin levels. Controls that either did not receive ferrous ions during training or received solutions other than ferrous solutions during training did not respond this way under extinction conditions. This is therefore a type of latent learning previously demonstrated only for sodium appetite.

  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. ENDOGENOUS ANALGESIA, DEPENDENCE, AND LATENT PAIN SENSITIZATION

    Science.gov (United States)

    Taylor, Bradley K; Corder, Gregory

    2015-01-01

    Endogenous activation of μ-opioid receptors (MORs) provides relief from acute pain. Recent studies have established that tissue inflammation produces latent pain sensitization (LS) that is masked by spinal MOR signaling for months, even after complete recovery from injury and re-establishment of normal pain thresholds. Disruption with MOR inverse agonists reinstates pain and precipitates cellular, somatic and aversive signs of physical withdrawal; this phenomenon requires N-methyl-D-aspartate receptor-mediated activation of calcium-sensitive adenylyl cyclase type 1 (AC1). In this review, we present a new conceptual model of the transition from acute to chronic pain, based on the delicate balance between LS and endogenous analgesia that develops after painful tissue injury. First, injury activates pain pathways. Second, the spinal cord establishes MOR constitutive activity (MORCA) as it attempts to control pain. Third, over time, the body becomes dependent on MORCA, which paradoxically sensitizes pain pathways. Stress or injury escalates opposing inhibitory and excitatory influences on nociceptive processing as a pathological consequence of increased endogenous opioid tone. Pain begets MORCA begets pain vulnerability in a vicious cycle. The final result is a silent insidious state characterized by the escalation of two opposing excitatory and inhibitory influences on pain transmission: LS mediated by AC1 (which maintains accelerator), and pain inhibition mediated by MORCA (which maintains the brake). This raises the prospect that opposing homeostatic interactions between MORCA analgesia and latent NMDAR–AC1-mediated pain sensitization create a lasting vulnerability to develop chronic pain. Thus, chronic pain syndromes may result from a failure in constitutive signaling of spinal MORs and a loss of endogenous analgesic control. An overarching long-term therapeutic goal of future research is to alleviate chronic pain by either: a) facilitating endogenous opioid

  3. Laser interrogation of latent vehicle registration number

    Energy Technology Data Exchange (ETDEWEB)

    Russo, R.E. [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.]|[Lawrence Livermore National Lab., CA (United States). Forensic Science Center; Pelkey, G.E. [City of Livermore Police Dept., CA (United States); Grant, P.; Whipple, R.E.; Andresen, B.D. [Lawrence Livermore National Lab., CA (United States). Forensic Science Center

    1994-09-01

    A recent investigation involved automobile registration numbers as important evidentiary specimens. In California, as in most states, small, thin metallic decals are issued to owners of vehicles each year as the registration is renewed. The decals are applied directly to the license plate of the vehicle and typically on top of the previous year`s expired decal. To afford some degree of security, the individual registration decals have been designed to tear easily; they cannot be separated from each other, but can be carefully removed intact from the metal license plate by using a razor blade. In September 1993, the City of Livermore Police Department obtained a blue 1993 California decal that had been placed over an orange 1992 decal. The two decals were being investigated as possible evidence in a case involving vehicle registration fraud. To confirm the suspicion and implicate a suspect, the department needed to known the registration number on the bottom (completely covered) 1992 decal. The authors attempted to use intense and directed light to interrogate the colored stickers. Optical illumination using a filtered white-light source partially identified the latent number. However, the most successful technique used a tunable dye laser pumped by a pulsed Nd:YAG laser. By selectively tuning the wavelength and intensity of the dye laser, backlit illumination of the decals permitted visualization of the underlying registration number through the surface of the top sticker. With optimally-tuned wavelength and intensity, 100% accuracy was obtained in identifying the sequence of latent characters. The advantage of optical techniques is their completely nondestructive nature, thus preserving the evidence for further interrogation or courtroom presentation.

  4. A Probability Distribution over Latent Causes, in the Orbitofrontal Cortex.

    Science.gov (United States)

    Chan, Stephanie C Y; Niv, Yael; Norman, Kenneth A

    2016-07-27

    The orbitofrontal cortex (OFC) has been implicated in both the representation of "state," in studies of reinforcement learning and decision making, and also in the representation of "schemas," in studies of episodic memory. Both of these cognitive constructs require a similar inference about the underlying situation or "latent cause" that generates our observations at any given time. The statistically optimal solution to this inference problem is to use Bayes' rule to compute a posterior probability distribution over latent causes. To test whether such a posterior probability distribution is represented in the OFC, we tasked human participants with inferring a probability distribution over four possible latent causes, based on their observations. Using fMRI pattern similarity analyses, we found that BOLD activity in the OFC is best explained as representing the (log-transformed) posterior distribution over latent causes. Furthermore, this pattern explained OFC activity better than other task-relevant alternatives, such as the most probable latent cause, the most recent observation, or the uncertainty over latent causes. Our world is governed by hidden (latent) causes that we cannot observe, but which generate the observations we see. A range of high-level cognitive processes require inference of a probability distribution (or "belief distribution") over the possible latent causes that might be generating our current observations. This is true for reinforcement learning and decision making (where the latent cause comprises the true "state" of the task), and for episodic memory (where memories are believed to be organized by the inferred situation or "schema"). Using fMRI, we show that this belief distribution over latent causes is encoded in patterns of brain activity in the orbitofrontal cortex, an area that has been separately implicated in the representations of both states and schemas. Copyright © 2016 the authors 0270-6474/16/367817-12$15.00/0.

  5. Assessing Trust and Effectiveness in Virtual Teams: Latent Growth Curve and Latent Change Score Models

    Directory of Open Access Journals (Sweden)

    Michael D. Coovert

    2017-08-01

    Full Text Available Trust plays a central role in the effectiveness of work groups and teams. This is the case for both face-to-face and virtual teams. Yet little is known about the development of trust in virtual teams. We examined cognitive and affective trust and their relationship to team effectiveness as reflected through satisfaction with one’s team and task performance. Latent growth curve analysis reveals both trust types start at a significant level with individual differences in that initial level. Cognitive trust follows a linear growth pattern while affective trust is overall non-linear, but becomes linear once established. Latent change score models are utilized to examine change in trust and also its relationship with satisfaction with the team and team performance. In examining only change in trust and its relationship to satisfaction there appears to be a straightforward influence of trust on satisfaction and satisfaction on trust. However, when incorporated into a bivariate coupling latent change model the dynamics of the relationship are revealed. A similar pattern holds for trust and task performance; however, in the bivariate coupling change model a more parsimonious representation is preferred.

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

    Science.gov (United States)

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

    2016-09-01

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

  7. Morphometry of latent palmprints as a function of time.

    Science.gov (United States)

    Barros, Rodrigo M; Faria, Bruna E F; Kuckelhaus, Selma A S

    2013-12-01

    In many crimes, the elapsed time between production and collecting fingermark traces is crucial. and a method able to detect the aging of latent prints would represent an improvement in forensic procedures. Considering that as the latent print gets older, substantial changes in the relative proportion of individual components secreted by skin glands could affect the morphology of ridges, morphometry could be a potential tool to assess the aging of latent fingermarks. Then, considering the very limited research in the field, the present work aims to evaluate the morphometry of latent palmprint ridges, as a function of time, in order to identify an aging pattern. The latent marks were deposited by 20 donors on glass microscope slides considering pressure and contact angle, and then were maintained under controlled environmental conditions. The morphometric study was conducted on marks developed with magnetic powder in 7 different time intervals after deposition (0, 5, 10, 15, 20, 25 or 30 days); 60 ridges were evaluated for each developed mark. The results showed that: 1) the method for the replacement and mixing of skin secretions on the palm was appropriate to ensure reproducibility of latent prints, and 2) considering the studied group, there was a time-dependent reduction in the width of ridges and on the percentage of visible ridges over 30 days. Results suggest the possibility of using the morphometric method to determine an aging profile of latent palmprints on glass surface, aiming for forensic purposes. © 2013.

  8. 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.

  9. 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.

  10. The latent rationality of risky decisions

    International Nuclear Information System (INIS)

    Japp, K.P.

    1999-01-01

    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

  11. Latent effectiveness of desiccant wheel: A silica gels- water system

    International Nuclear Information System (INIS)

    Rabah, A. A.; Mohamed, S. A.

    2009-01-01

    A latent heat effectiveness model in term of dimensionless groups? =f (NTU, m * ,Crm * ) for energy wheel has been analytically derived. The energy wheel is divided into humidification and dehumidification sections. For each section macroscopic mass differential equations for gas and the matrix were applied. In this process local latent effectiveness (? c ,? h ) for the humidification and dehumidification section of the wheel were obtained. The Latent effectiveness of the wheel is then derived form local effectiveness [? =f (? c ,? h)]. The model is compared with the existing experimental investigation and manufacturer data for energy wheel. More than 90% of the experimental data within a confidence limit of 95%. (Author)

  12. Towards an HIV-1 cure: measuring the latent reservoir

    Science.gov (United States)

    Bruner, Katherine M.; Hosmane, Nina N.; Siliciano, Robert F.

    2015-01-01

    The latent reservoir of HIV-1 in resting memory CD4+ T cells serves as a major barrier to curing HIV-1 infection. While many PCR- and culture-based assays have been used to measure the size of the latent reservoir, correlation between results of different assays is poor and recent studies indicate that no available assay provides an accurate measurement of reservoir size. The discrepancies between assays are a hurdle to clinical trials that aim to measure the efficacy of HIV-1 eradication strategies. Here we describe the advantages and disadvantages of various approaches to measure the latent reservoir. PMID:25747663

  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. 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.

  15. A developmental study of latent absolute pitch memory.

    Science.gov (United States)

    Jakubowski, Kelly; Müllensiefen, Daniel; Stewart, Lauren

    2017-03-01

    The ability to recall the absolute pitch level of familiar music (latent absolute pitch memory) is widespread in adults, in contrast to the rare ability to label single pitches without a reference tone (overt absolute pitch memory). The present research investigated the developmental profile of latent absolute pitch (AP) memory and explored individual differences related to this ability. In two experiments, 288 children from 4 to12 years of age performed significantly above chance at recognizing the absolute pitch level of familiar melodies. No age-related improvement or decline, nor effects of musical training, gender, or familiarity with the stimuli were found in regard to latent AP task performance. These findings suggest that latent AP memory is a stable ability that is developed from as early as age 4 and persists into adulthood.

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

    KAUST Repository

    Irincheeva, Irina; Cantoni, Eva; Genton, Marc G.

    2012-01-01

    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.

  17. Studies of Latent Acidity and Neutral Buffered Chloroaluminate Ionic Liquids

    National Research Council Canada - National Science Library

    Osteryoung, Robert

    2000-01-01

    Studies on ionic liquids composed of aluminum chloride and 1-ethyl-3-methylimidazolium chloride were carried out, with emphasis on understanding and explaining acidity and latent acidity in "neutral buffered" melts...

  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. 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.

  20. Classification criteria of syndromes by latent variable models

    DEFF Research Database (Denmark)

    Petersen, Janne

    2010-01-01

    patient's characteristics. These methods may erroneously reduce multiplicity either by combining markers of different phenotypes or by mixing HALS with other processes such as aging. Latent class models identify homogenous groups of patients based on sets of variables, for example symptoms. As no gold......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...... standard exists for diagnosing HALS the normally applied diagnostic models cannot be used. Latent class models, which have never before been used to diagnose HALS, make it possible, under certain assumptions, to: statistically evaluate the number of phenotypes, test for mixing of HALS with other processes...

  1. Latent-failure risk estimates for computer control

    Science.gov (United States)

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

    1991-01-01

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

  2. 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.

  3. Translating latent trends in food consumer behavior into new products

    OpenAIRE

    Gellynck, Xavier; Kühne, Bianka; Van Wezemael, Lynn; Verbeke, Wim

    2010-01-01

    For successful product development it is important to explore the latent changes in consumer behavior prior to the product development process. The identification of a latent trend before the manifestation moment can be achieved by trend analysis. Trend analysis delivers insights that explore the future in order to identify prospective consumers and new product ideas, but also includes a feeling for the currents in market and technology. Hence, the aim is to identify emerging weak signals in ...

  4. Latent inhibition as a function of US intensity in a two-stage CER procedure

    Directory of Open Access Journals (Sweden)

    Gumersinda Alonso

    2004-01-01

    Full Text Available En el experimento que presentamos se examinó el efecto de la intensidad del estímulo incondicionado (EI sobre la inhibición latente (IL, empleando un procedimiento de respuesta emocional condicionada (REC de dos fases, con ratas como sujetos experimentales. Se utilizó un tono como estímulo preexpuesto y estímulo condicionado (EC, y una descarga, de intensidad baja (0.3 mA o alta (0.7 mA, como EI. Se empleó un diseño factorial 2 x 2. El primer factor fue la condición de preexposición (72 preexposiciones o sin preexposición y el segundo factor fue la intensidad de la descarga (baja o alta. Se observó un efecto de IL más duradero en la condición de intensidad baja que en la condición de intensidad alta. Se discute la posibilidad de que la intensidad del EI module o bien un proceso de restauración de la atención al EC durante el condicionamiento o bien un cambio contextual, responsable de la atenuación del efecto de IL en la condición de intensidad alta, respecto a la condición de intensidad baja.

  5. Cytokine profile in patients with early latent syphilis

    Directory of Open Access Journals (Sweden)

    Zakharov S.V.

    2018-03-01

    Full Text Available The purpose of this study was to study the change in the content of the most active cytokines (interleukins 6 and 10 during the formation of the immune response in patients with latent early syphilis, as well as to study the possible relationship between the concentrations of these cytokines and the duration of the disease. In 50 patients with early latent syphilis, the concentration of interleukins 6 and 10 in serum was studied. The serum level of interleukins was studied by the enzyme immunoassay. A statistically significant increase in the concentration of interleukin 6 in the blood of patients with latent syphilis and decrease in the interleukin 10 concentration in comparison with healthy people was established. At the same time, in patients with latent syphilis with term of infection for more than 1 year, interleukin 10 has been expressed, as compared with healthy people and, especially, with patients with syphilis with a duration of infection of up to 1 year. Along with this, a lower degree of increase in the concentration of interleukin 6 in patients with latent syphilis with a duration of infection over 1 year has been established, as compared with patients with latent syphilis with a term of infection up to 1 year, against the background of its increased concentration as compared with a group of healthy individuals.

  6. Latent fingerprints on different type of screen protective films

    Directory of Open Access Journals (Sweden)

    Yuttana Sudjaroen

    2016-07-01

    Full Text Available The purpose of this research was to study the quality of latent fingerprint on different types of screen protective films including screen protector, matte screen protector, anti-fingerprint clear screen protector and anti-fingerprint matte screen protector by using black powder method in developing latent fingerprints. The fingerprints were performed by 10 volunteers whose fingers (right index, right thumb, left index and left thumb were stubbing at different types of screen protective films and subsequently latent fingerprints were developed by brushing with black powder. Automated Fingerprint Identification System (AFIS counted the numbers of minutiae points from 320 latent fingerprints. Anti-fingerprint matte screen protective film produced the best quality of latent fingerprint with an average minutiae point 72.65, followed by matte screen protective film, clear screen protective film and anti-fingerprint clear screen protective film with an average minutiae point of 155.2, 135.0 and 72.65 respectively. The quality of latent fingerprints developed between a clear and a matte surface of screen protective films showed a significant difference (sig>0.05, whereas the coat and the non-coat with anti-fingerprint chemical revealed a non-significant difference (sig<0.05 in their number of minutiae points.

  7. 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

  8. Avoiding and Correcting Bias in Score-Based Latent Variable Regression with Discrete Manifest Items

    Science.gov (United States)

    Lu, Irene R. R.; Thomas, D. Roland

    2008-01-01

    This article considers models involving a single structural equation with latent explanatory and/or latent dependent variables where discrete items are used to measure the latent variables. Our primary focus is the use of scores as proxies for the latent variables and carrying out ordinary least squares (OLS) regression on such scores to estimate…

  9. A flexible latent class approach to estimating test-score reliability

    NARCIS (Netherlands)

    van der Palm, D.W.; van der Ark, L.A.; Sijtsma, K.

    2014-01-01

    The latent class reliability coefficient (LCRC) is improved by using the divisive latent class model instead of the unrestricted latent class model. This results in the divisive latent class reliability coefficient (DLCRC), which unlike LCRC avoids making subjective decisions about the best solution

  10. Latent Transition Analysis with a Mixture Item Response Theory Measurement Model

    Science.gov (United States)

    Cho, Sun-Joo; Cohen, Allan S.; Kim, Seock-Ho; Bottge, Brian

    2010-01-01

    A latent transition analysis (LTA) model was described with a mixture Rasch model (MRM) as the measurement model. Unlike the LTA, which was developed with a latent class measurement model, the LTA-MRM permits within-class variability on the latent variable, making it more useful for measuring treatment effects within latent classes. A simulation…

  11. 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

  12. 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.

  13. Ridge Width Correlations between Inked Prints and Powdered Latent Fingerprints.

    Science.gov (United States)

    De Alcaraz-Fossoul, Josep; Barrot-Feixat, Carme; Zapico, Sara C; Mancenido, Michelle; Broatch, Jennifer; Roberts, Katherine A; Carreras-Marin, Clara; Tasker, Jack

    2017-10-03

    A methodology to estimate the time of latent fingerprint deposition would be of great value to law enforcement and courts. It has been observed that ridge topography changes as latent prints age, including the widths of ridges that could be measured as a function of time. Crime suspects are commonly identified using fingerprint databases that contain reference inked tenprints (flat and rolled impressions). These can be of interest in aging studies as they provide baseline information relating to the original (nonaged) ridges' widths. In practice, the age of latent fingerprints could be estimated following a comparison process between the evidentiary aged print and the corresponding reference inked print. The present article explores possible correlations between inked and fresh latent fingerprints deposited on different substrates and visualized with TiO 2 . The results indicate that the ridge width of flat inked prints is most similar to fresh latent fingerprints , and these should be used as the comparison standard for future aging studies. © 2017 American Academy of Forensic Sciences.

  14. Study of noninvasive detection of latent fingerprints using UV laser

    Science.gov (United States)

    Li, Hong-xia; Cao, Jing; Niu, Jie-qing; Huang, Yun-gang; Mao, Lin-jie; Chen, Jing-rong

    2011-06-01

    Latent fingerprints present a considerable challenge in forensics, and noninvasive procedure that captures a digital image of the latent fingerprints is significant in the field of criminal investigation. The capability of photography technologies using 266nm UV Nd:YAG solid state laser as excitation light source to provide detailed images of unprocessed latent fingerprints is demonstrated. Unprocessed latent fingerprints were developed on various non-absorbent and absorbing substrates. According to the special absorption, reflection, scattering and fluorescence characterization of the various residues in fingerprints (fatty acid ester, protein, and carbosylic acid salts etc) to the UV light to weaken or eliminate the background disturbance and increase the brightness contrast of fingerprints with the background, and using 266nm UV laser as excitation light source, fresh and old latent fingerprints on the surface of four types of non-absorbent objects as magazine cover, glass, back of cellphone, wood desktop paintwork and two types of absorbing objects as manila envelope, notebook paper were noninvasive detected and appeared through reflection photography and fluorescence photography technologies, and the results meet the fingerprint identification requirements in forensic science.

  15. 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.

  16. 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

  17. Potencial del Agua del suelo

    Directory of Open Access Journals (Sweden)

    Bustamante Heliodoro

    1986-12-01

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

  18. 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.

  19. The latent effect of inertia in the modal choice

    DEFF Research Database (Denmark)

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

    2014-01-01

    The existence of habit (leading to inertia) in the choice process has been approached in the literature in a number of ways. In transport, inertia has been studied mainly using “long panel” data, or mixed revealed and stated preference data. In these studies inertia links the choice made in two...... approaches. We assume that inertia is revealed by past behaviour and affects also the initial condition, but we recognise that past behaviour is only an indicator of habitual behaviour, the true process behind the formation of habitual behaviour being latent. We estimate a hybrid choice model using a set...... of 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...

  20. 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

  1. La Antracnosis del olivo y su efecto en la calidad del aceite

    Directory of Open Access Journals (Sweden)

    Moral, J.

    2014-06-01

    Full Text Available Olive (Olea europaea subsp. europaea var. europaea is one of the first domesticated and cultivated trees that is widely distributed in the Mediterranean regions. The Anthracnose, caused by the two complex fungal species Colletotrichum acutatum and C. gloeosporioides, is the most important disease adversely affecting the olive oil quality. Even so, the effect of Anthracnose on oil quality is largely unknown and many questions remain unanswered. This offers a unique opportunity to study how Colletotrichum species, cultivars, infection type (latent or visible and severity, and other factors that may affect different parameters of oil quality, such us acidity, peroxide value, K232, K270, phenolic compounds, or alkyl esters. This review focuses on the current knowledge of the biology, epidemiology, and management of Anthracnose and its effect on olive oil quality.El olivo (Olea europaea subsp. europaea var. europaea es uno de los primeros cultivos leñosos domesticados. Actualmente el olivo se encuentra ampliamente distribuido por todas las regiones de clima mediterráneo. La Antracnosis, causada por las especies complejas Colletotrichum acutatum y C. gloeosporioides, es la enfermedad del olivo que más afecta a la calidad del aceite. Aun así, el efecto de la Antracnosis en la calidad del aceite es ampliamente desconocido. Por lo que creemos esencial que se afronten estudios encaminados a dilucidar el efecto de las especies del patógeno, el cultivar de olivo y el tipo (latente o visible y severidad de las infecciones de la aceituna en los distintos parámetros de calidad del aceite como la acidez, índice de peróxidos, K232, K270, compuestos fenólicos o ésteres alquílicos. Esta revisión presenta los conocimientos actuales sobre la biología, epidemiología, control, y efecto en la calidad del aceite de la Antracnosis del olivo.

  2. 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. Published by Elsevier Ireland Ltd.

  3. Effects of latent toxoplasmosis on autoimmune thyroid diseases in pregnancy.

    Science.gov (United States)

    Kaňková, Šárka; Procházková, Lucie; Flegr, Jaroslav; Calda, Pavel; Springer, Drahomíra; Potluková, Eliška

    2014-01-01

    Toxoplasmosis, one of the most common zoonotic diseases worldwide, can induce various hormonal and behavioural alterations in infected hosts, and its most common form, latent toxoplasmosis, influences the course of pregnancy. Autoimmune thyroid diseases (AITD) belong to the well-defined risk factors for adverse pregnancy outcomes. The aim of this study was to investigate whether there is a link between latent toxoplasmosis and maternal AITD in pregnancy. Cross-sectional study in 1248 consecutive pregnant women in the 9-12th gestational weeks. Serum thyroid-stimulating hormone (TSH), thyroperoxidase antibodies (TPOAb), and free thyroxine (FT4) were assessed by chemiluminescence; the Toxoplasma status was detected by the complement fixation test (CFT) and anti-Toxoplasma IgG enzyme-linked immunosorbent assay (ELISA). Overall, 22.5% of the women were positive for latent toxoplasmosis and 14.7% were screened positive for AITD. Women with latent toxoplasmosis had more often highly elevated TPOAb than the Toxoplasma-negative ones (p = 0.004), and latent toxoplasmosis was associated with decrease in serum TSH levels (p = 0.049). Moreover, we found a positive correlation between FT4 and the index of positivity for anti-Toxoplasma IgG antibodies (p = 0.033), which was even stronger in the TPOAb-positive Toxoplasma-positive women, (p = 0.014), as well as a positive correlation between FT4 and log2 CFT (p = 0.009). Latent toxoplasmosis was associated with a mild increase in thyroid hormone production in pregnancy. The observed Toxoplasma-associated changes in the parameters of AITD are mild and do not seem to be clinically relevant; however, they could provide new clues to the complex pathogenesis of autoimmune thyroid diseases.

  4. 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

    2013-10-01

    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. Using a conventional latent variable approach, we derived an antisocial phenotype in 328 adolescents utilizing data from a 15-year follow-up of a randomized trial of a prenatal and infancy nurse-home visitation programme in Elmira, New York. We then investigated, via a novel latent variable approach, 450 informative genetic polymorphisms in 71 genes previously associated with antisocial behaviour, drug use, affiliative behaviours and stress response in 241 consenting individuals for whom DNA was available. Haplotype and Pathway analyses were also performed. Eight single-nucleotide polymorphisms (SNPs) from eight genes contributed to the latent genetic variable that in turn accounted for 16.0% of the variance within the latent antisocial phenotype. The number of risk alleles was linearly related to the latent antisocial variable scores. Haplotypes that included the putative risk alleles for all eight genes were also associated with higher latent antisocial variable scores. In addition, 33 SNPs from 63 of the remaining genes were also significant when added to the final model. Many of these genes interact on a molecular level, forming molecular networks. The results support a role for genes related to dopamine, norepinephrine, serotonin, glutamate, opioid and cholinergic signalling as well as stress response pathways in mediating susceptibility to antisocial behaviour. This preliminary study supports use of relevant behavioural indicators and latent variable approaches to study the potential 'co-action' of gene variants associated with antisocial behaviour. It also underscores the cumulative relevance of common genetic variants for understanding the aetiology of complex behaviour. If replicated in future studies, this approach may allow the identification of a

  5. A coarse to fine minutiae-based latent palmprint matching.

    Science.gov (United States)

    Liu, Eryun; Jain, Anil K; Tian, Jie

    2013-10-01

    With the availability of live-scan palmprint technology, high resolution palmprint recognition has started to receive significant attention in forensics and law enforcement. In forensic applications, latent palmprints provide critical evidence as it is estimated that about 30 percent of the latents recovered at crime scenes are those of palms. Most of the available high-resolution palmprint matching algorithms essentially follow the minutiae-based fingerprint matching strategy. Considering the large number of minutiae (about 1,000 minutiae in a full palmprint compared to about 100 minutiae in a rolled fingerprint) and large area of foreground region in full palmprints, novel strategies need to be developed for efficient and robust latent palmprint matching. In this paper, a coarse to fine matching strategy based on minutiae clustering and minutiae match propagation is designed specifically for palmprint matching. To deal with the large number of minutiae, a local feature-based minutiae clustering algorithm is designed to cluster minutiae into several groups such that minutiae belonging to the same group have similar local characteristics. The coarse matching is then performed within each cluster to establish initial minutiae correspondences between two palmprints. Starting with each initial correspondence, a minutiae match propagation algorithm searches for mated minutiae in the full palmprint. The proposed palmprint matching algorithm has been evaluated on a latent-to-full palmprint database consisting of 446 latents and 12,489 background full prints. The matching results show a rank-1 identification accuracy of 79.4 percent, which is significantly higher than the 60.8 percent identification accuracy of a state-of-the-art latent palmprint matching algorithm on the same latent database. The average computation time of our algorithm for a single latent-to-full match is about 141 ms for genuine match and 50 ms for impostor match, on a Windows XP desktop system with 2

  6. Rapid detection of drug metabolites in latent fingermarks.

    Science.gov (United States)

    Hazarika, Pompi; Jickells, Sue M; Russell, David A

    2009-01-01

    Magnetic particles functionalised with anti-cotinine antibody have been used to image latent fingermarks through the detection of the cotinine antigen in the sweat deposited within the fingerprints of smokers. The antibody-magnetic particle conjugates are readily applied to latent fingerprints while excess reagents are removed through the use of a magnetic wand. The results have shown that drug metabolites, such as cotinine, can be detected and used to image the fingermark to establish the identity of an individual within 15 minutes.

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

    Science.gov (United States)

    Lieberman, Paul M

    2015-01-01

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

  8. On the explaining-away phenomenon in multivariate latent variable models.

    Science.gov (United States)

    van Rijn, Peter; Rijmen, Frank

    2015-02-01

    Many probabilistic models for psychological and educational measurements contain latent variables. Well-known examples are factor analysis, item response theory, and latent class model families. We discuss what is referred to as the 'explaining-away' phenomenon in the context of such latent variable models. This phenomenon can occur when multiple latent variables are related to the same observed variable, and can elicit seemingly counterintuitive conditional dependencies between latent variables given observed variables. We illustrate the implications of explaining away for a number of well-known latent variable models by using both theoretical and real data examples. © 2014 The British Psychological Society.

  9. Representações de masculinidades latentes em aulas de física do ensino médio

    Directory of Open Access Journals (Sweden)

    Josimeire M. Julio

    2009-01-01

    Full Text Available El estudio caracteriza aspectos latentes de masculinidades que traen implicaciones para el aprendizaje individual y colectivo de una clase de la escuela secundaria. Clases de física del primer año de una escuela secundaria fueron acompañadas a lo largo de un año. A microanálisis de una secuencia de seis clases - gravadas en audio y en video - envolviendo una actividad que simula el trabajo de una comunidad científica, caracteriza las interacciones predominantes entre los jóvenes. Las masculinidades destacadas se movilizan en torno del estímulo frente a situaciones desafiantes y de competición, de la curiosidad por el fenómeno investigado, del desafío a las reglas establecidas en la conducción de la actividad. Entre las implicaciones del estudio, se destaca la necesidad de tener en cuenta las manifestaciones de masculinidades que puedan comprometer el desarrollo de las actividades en la clase y el funcionamiento de los grupos de aprendizaje.

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

    Directory of Open Access Journals (Sweden)

    Diana Isabel Ocampo Rodríguez

    2015-10-01

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

  11. Longitudinal mixed-effects models for latent cognitive function

    NARCIS (Netherlands)

    van den Hout, Ardo; Fox, Gerardus J.A.; Muniz-Terrera, Graciela

    2015-01-01

    A mixed-effects regression model with a bent-cable change-point predictor is formulated to describe potential decline of cognitive function over time in the older population. For the individual trajectories, cognitive function is considered to be a latent variable measured through an item response

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

    Science.gov (United States)

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

    2012-01-01

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

  13. 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…

  14. On Latent Growth Models for Composites and Their Constituents.

    Science.gov (United States)

    Hancock, Gregory R; Mao, Xiulin; Kher, Hemant

    2013-09-01

    Over the last decade and a half, latent growth modeling has become an extremely popular and versatile technique for evaluating longitudinal change and its determinants. Most common among the models applied are those for a single measured variable over time. This model has been extended in a variety of ways, most relevant for the current work being the multidomain and the second-order latent growth models. Whereas the former allows for growth function characteristics to be modeled for multiple outcomes simultaneously, with the degree of growth characteristics' relations assessed within the model (e.g., cross-domain slope factor correlations), the latter models growth in latent outcomes, each of which has effect indicators repeated over time. But what if one has an outcome that is believed to be formative relative to its indicator variables rather than latent? In this case, where the outcome is a composite of multiple constituents, modeling change over time is less straightforward. This article provides analytical and applied details for simultaneously modeling growth in composites and their constituent elements, including a real data example using a general computer self-efficacy questionnaire.

  15. The Latent Structure of Secure Base Script Knowledge

    Science.gov (United States)

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

    2015-01-01

    There is increasing evidence that attachment representations abstracted from childhood experiences with primary caregivers are organized as a cognitive script describing secure base use and support (i.e., the "secure base script"). To date, however, the latent structure of secure base script knowledge has gone unexamined--this despite…

  16. 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…

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

    Directory of Open Access Journals (Sweden)

    Jeban Ganesalingam

    2009-09-01

    Full Text Available 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.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.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.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. Evaluation of AFIS-Ranked latent fingerprint matched templates

    NARCIS (Netherlands)

    Krish, Ram P.; Fierrez, Julian; Ramos, Daniel; Veldhuis, Raymond N.J.; 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

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  20. Latent Toxoplasma gondii infection leads to improved action control.

    Science.gov (United States)

    Stock, Ann-Kathrin; Heintschel von Heinegg, Evelyn; Köhling, Hedda-Luise; Beste, Christian

    2014-03-01

    The parasite Toxoplasma gondii has been found to manipulate the behavior of its secondary hosts to increase its own dissemination which is commonly believed to be to the detriment of the host (manipulation hypothesis). The manipulation correlates with an up-regulation of dopaminergic neurotransmission. In humans, different pathologies have been associated with T. gondii infections but most latently infected humans do not seem to display overt impairments. Since a dopamine plus does not necessarily bear exclusively negative consequences in humans, we investigated potential positive consequences of latent toxoplasmosis (and the presumed boosting of dopaminergic neurotransmission) on human cognition and behavior. For this purpose, we focused on action cascading which has been shown to be modulated by dopamine. Based on behavioral and neurophysiological (EEG) data obtained by means of a stop-change paradigm, we were able to demonstrate that healthy young humans can actually benefit from latent T. gondii infection as regards their performance in this task (as indicated by faster response times and a smaller P3 component). The data shows that a latent infection which is assumed to affect the dopaminergic system can lead to paradoxical improvements of cognitive control processes in humans. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Prevalence and risk factors of latent Tuberculosis among ...

    African Journals Online (AJOL)

    termine the risk factors of prevalent LTBI. We used a mixed effects binomial model with a logarithmic link function to estimate prevalence ratios (PR) for risk fac- tors of latent tuberculosis infection (LTBI). Ethical consideration. The study was approved by the Makerere University. School of Public Health–Higher Degrees and ...

  2. 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...

  3. Latent Partially Ordered Classification Models and Normal Mixtures

    Science.gov (United States)

    Tatsuoka, Curtis; Varadi, Ferenc; Jaeger, Judith

    2013-01-01

    Latent partially ordered sets (posets) can be employed in modeling cognitive functioning, such as in the analysis of neuropsychological (NP) and educational test data. Posets are cognitively diagnostic in the sense that classification states in these models are associated with detailed profiles of cognitive functioning. These profiles allow for…

  4. 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…

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

    Science.gov (United States)

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

    2015-02-01

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

  6. Investigating design: A comparison of manifest and latent approaches

    DEFF Research Database (Denmark)

    Cash, Philip; Snider, Chris

    2014-01-01

    This paper contributes to the on-going focus on improving design research methods, by exploring and synthesising two key interrelated research approaches e manifest and latent. These approaches are widely used individually in design research, however, this paper represents the first work bringing...

  7. Preferences, benefits, and park visits: a latent class segmentation analysis

    NARCIS (Netherlands)

    Kemperman, A.D.A.M.; Timmermans, H.J.P.

    2006-01-01

    This study describes and predicts segments of urban park visitors to support park planning and policy making. A latent class analysis is used to identify segments of park users who differ regarding their preferences for park characteristics, benefits sought in park visits, and sociodemographics.

  8. 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...

  9. Effect Of Prolonged Monocular Occlusion On Latent Nystagms

    NARCIS (Netherlands)

    H.J. Simonsz (Huib); G. Kommerell (Guntram)

    1992-01-01

    textabstractThe authors recorded nystagmus during seeing with one eye in eight patients with latent nystagmus (LN) before and after two or three days of prolonged occlusion of the better eye (POBE). Before POBE, the slow-phase speed of the nystagmus (SPS) was usually higher when the better eye was

  10. del alcoholismo

    Directory of Open Access Journals (Sweden)

    Rodrigo Arias Duque

    2005-01-01

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

  11. Calculating latent frequencies of systems with local damping

    International Nuclear Information System (INIS)

    Kolonits, Ferenc

    2005-01-01

    Modal analysis of damped systems often cannot proceed with common real-eigenvalue techniques. The system of equilibrium equations leads to a matrix with elements being quadratic functions of a parameter λ. The values of that which make the matrix singular are the latent roots, while the solutions of the associated homogenous equation are the latent vectors. They are the (generally complex) characteristic frequencies and the mode shapes of the system, respectively. Although the theory is well developed, the numerical application is open to refinements yet. A reduction to better-known real-domain subtasks deserves attention. With a theorem of Popper and Gaspar, a n x n λ-matrix problem can be cut in two: into n-size asymmetric real matrices having as eigenvalues the n lower and n upper latent roots, ranked by absolute value. This approach may be of use for systems with high number of degrees of freedom while damped by a relatively few concentrated devices. It might fit also an earthquake analysis, where the lower portion of eigenvalues is customarily what counts. The dampers appear in the splitting algorithm as restricted-size modifications, ready for use by the Sherman-Morrison-Woodbury identity. The task is re-traced this way to a more usual real-asymmetric eigenproblem. A requirement of convergence is that the lower and upper n-set of latent values must be distinct. With odd-number degrees of freedom and neither over-damped, i.e. all latent roots being complex, this condition is surely violated. For such cases, a supplemental algorithm is proposed

  12. 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.

  13. Estimators for longitudinal latent exposure models: examining measurement model assumptions.

    Science.gov (United States)

    Sánchez, Brisa N; Kim, Sehee; Sammel, Mary D

    2017-06-15

    Latent variable (LV) models are increasingly being used in environmental epidemiology as a way to summarize multiple environmental exposures and thus minimize statistical concerns that arise in multiple regression. LV models may be especially useful when multivariate exposures are collected repeatedly over time. LV models can accommodate a variety of assumptions but, at the same time, present the user with many choices for model specification particularly in the case of exposure data collected repeatedly over time. For instance, the user could assume conditional independence of observed exposure biomarkers given the latent exposure and, in the case of longitudinal latent exposure variables, time invariance of the measurement model. Choosing which assumptions to relax is not always straightforward. We were motivated by a study of prenatal lead exposure and mental development, where assumptions of the measurement model for the time-changing longitudinal exposure have appreciable impact on (maximum-likelihood) inferences about the health effects of lead exposure. Although we were not particularly interested in characterizing the change of the LV itself, imposing a longitudinal LV structure on the repeated multivariate exposure measures could result in high efficiency gains for the exposure-disease association. We examine the biases of maximum likelihood estimators when assumptions about the measurement model for the longitudinal latent exposure variable are violated. We adapt existing instrumental variable estimators to the case of longitudinal exposures and propose them as an alternative to estimate the health effects of a time-changing latent predictor. We show that instrumental variable estimators remain unbiased for a wide range of data generating models and have advantages in terms of mean squared error. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Perceptions of care in women sent home in latent labor.

    Science.gov (United States)

    Hosek, Claire; Faucher, Mary Ann; Lankford, Janice; Alexander, James

    2014-01-01

    To assess perceptions of care from woman discharged from an obstetrical (OB) triage unit or a labor and delivery unit with a diagnosis of false or latent labor in order to determine factors that may increase or decrease the woman's satisfaction with care. Descriptive, convenience sample. One hundred low-income pregnant women at term presenting for care in latent labor consented to participate in a telephone survey. The survey was based on the relevant research about care of women in early labor and the Donabedian quality improvement framework assessing structure, process, and outcomes of care. Forty-one percent of women did not want to be discharged home in latent labor. Common reasons included women stating they were in too much pain or they were living too far from the birth setting. Eating, drinking, and comfort measures were the most common measures women cited that would have made them feel better when in the hospital. A reoccurring response from women was their desire for very clear and specific written instructions about how to stay comfortable at home and when to return to the hospital. Comfort measures in the birth setting, including in triage, should include a variety of options including ambulation and oral nutrition. Detailed and specific written instructions about early labor and staying comfortable while at home have value for women in this survey regarding their perceptions of care. Results from this survey of low-income women suggest that a subset of women in latent labor just do not want to go home and this may be related to having too much pain and/or travel distance to the hospital. Hospital birth settings also have an opportunity to create a care environment that provides services and embodies attributes that women report as important for their satisfaction with care in latent labor.

  15. Using standard serology blood tests to diagnose latent syphilis

    Directory of Open Access Journals (Sweden)

    G. L. Katunin

    2016-01-01

    Full Text Available Goal. To conduct a comparative assessment of the results of regulated serological tests obtained as a result of blood tests in patients suffering from latent syphilis. Materials and methods. The authors examined 187 patient medical records with newly diagnosed latent syphilis in FGBU GNTsDK (State Research Center for Dermatology, Venereology and Cosmetology, Health Ministry of the Russian Federation, in 2006-2015. The results of patient blood tests were analyzed with the use of non-treponemal (microprecipitation test/RPR and treponemal (passive hemagglutination test, immune-enzyme assay (IgA, IgM, IgG, IFabs, immunofluorescence test and Treponema pallidum immobilization test serology tests. Results. According to the results of blood tests of latent syphilis patients, the largest number of positive results was obtained as a result of treponemal serology tests such as immune-enzyme assay (100%, passive hemagglutination test (100% and IFabs (100%. The greatest number of negative results was observed in non-treponemal (microprecipitation test/RPR serology tests: in 136 (72.7% patients; evidently positive results (4+ test results were obtained in 8 (4.3% patients only. According to the results of a comparative analysis of blood tests in patients suffering from latent syphilis obtained with the use of treponemal serology tests, the greatest number of evidently positive results (4+ was noted for the passive hemagglutination test (67.9%. Negative treponemal test results were obtained with the use of the immunofluorescence test and Treponema pallidum immobilization test (21.9% and 11.8% of cases, respectively. Moreover, weakly positive results prevailed for the immunofluorescence test: in 65 (34.7% patients. Conclusion. These data confirm that the following treponemal tests belong to the most reliable ones for revealing patients suffering from latent syphilis: immune-enzyme assay, passive hemagglutination test and IFabs.

  16. Manejo del plagas de árboles frutales deciduos durante el invierno

    OpenAIRE

    Geisel, Pamela M; Seaver, Donna C

    2009-01-01

    La época latente de invierno es el momento para tratar los árboles frutales contra plagas como la cochinilla, los ácaros, el perforador del duraznero, los áfidos y los hongos como el torque de hoja y el barrenillo. ¡Que aproveche! Spanish edition of “Winter Pest Management in Backyard Deciduous Fruit Trees” (Publication 8368).

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

    Science.gov (United States)

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

    2009-01-01

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

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  19. The Integration of Continuous and Discrete Latent Variable Models: Potential Problems and Promising Opportunities

    Science.gov (United States)

    Bauer, Daniel J.; Curran, Patrick J.

    2004-01-01

    Structural equation mixture modeling (SEMM) integrates continuous and discrete latent variable models. Drawing on prior research on the relationships between continuous and discrete latent variable models, the authors identify 3 conditions that may lead to the estimation of spurious latent classes in SEMM: misspecification of the structural model,…

  20. 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...

  1. 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.

  2. Age is associated with latent tuberculosis in nurses

    Directory of Open Access Journals (Sweden)

    Naesinee Chaiear

    2016-12-01

    Full Text Available Objective: To evaluate risk factors for developing latent tuberculosis (LTB in Thai nurses. Methods: A comparison study was conducted at Srinagarind Hospital, Khon Kaen, Thailand. Clinical factors were compared between persons with tuberculin conversion and those without tuberculin conversion identified by tuberculin skin test. Results: There were 173 eligible persons with the LTB (34.7%. There were five workplaces where participants worked regularly including the general ward, surgical ward, pediatric ward, medical ward and critical care ward. In a multivariate model, two factors were significantly associated with LTB including age and history of tuberculosis in colleagues. The adjusted odds ratio (95% confidence interval of both variables were 1.056 (1.004–1.104 and 0.202 (0.044– 0.941. Conclusions: Older age is associated with latent tuberculosis in nurses. LTB should be screened routinely and treated if diagnosed for nurses.

  3. 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.

  4. Managing latent tuberculosis infection and tuberculosis in children

    Directory of Open Access Journals (Sweden)

    I. Carvalho

    2018-03-01

    Full Text Available Tuberculosis (TB is a major cause of childhood morbidity and mortality worldwide. The aim of this review is to describe the management of the child with TB and latent tuberculosis infection (LTBI.To develop this article, a working group reviewed relevant epidemiological and other scientific studies and established practices in conducting LBTI and TB in children. The article describes how to manage the child with LTBI, considering transmission and infectiousness of tuberculosis, contact screening and prioritization of contacts and recommendations on treatment of children with LTBI and how to manage the child with TB considering the susceptibility of children to developing tuberculosis, epidemiology and classification of tuberculosis in children, diagnosis and treatment. Keywords: Tuberculosis, Pediatric, Childhood, Latent tuberculosis infection

  5. Linear latent variable models: the lava-package

    DEFF Research Database (Denmark)

    Holst, Klaus Kähler; Budtz-Jørgensen, Esben

    2013-01-01

    are implemented including robust standard errors for clustered correlated data, multigroup analyses, non-linear parameter constraints, inference with incomplete data, maximum likelihood estimation with censored and binary observations, and instrumental variable estimators. In addition an extensive simulation......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...

  6. 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.

  7. Latent factor structure of a behavioral economic marijuana demand curve.

    Science.gov (United States)

    Aston, Elizabeth R; Farris, Samantha G; MacKillop, James; Metrik, Jane

    2017-08-01

    Drug demand, or relative value, can be assessed via analysis of behavioral economic purchase task performance. Five demand indices are typically obtained from drug purchase tasks. The goal of this research was to determine whether metrics of marijuana reinforcement from a marijuana purchase task (MPT) exhibit a latent factor structure that efficiently characterizes marijuana demand. Participants were regular marijuana users (n = 99; 37.4% female, 71.5% marijuana use days [5 days/week], 15.2% cannabis dependent) who completed study assessments, including the MPT, during a baseline session. Principal component analysis was used to examine the latent structure underlying MPT indices. Concurrent validity was assessed via examination of relationships between latent factors and marijuana use, past quit attempts, and marijuana expectancies. A two-factor solution was confirmed as the best fitting structure, accounting for 88.5% of the overall variance. Factor 1 (65.8% variance) reflected "Persistence," indicating sensitivity to escalating marijuana price, which comprised four MPT indices (elasticity, O max , P max , and breakpoint). Factor 2 (22.7% variance) reflected "Amplitude," indicating the amount consumed at unrestricted price (intensity). Persistence factor scores were associated with fewer past marijuana quit attempts and lower expectancies of negative use outcomes. Amplitude factor scores were associated with more frequent use, dependence symptoms, craving severity, and positive marijuana outcome expectancies. Consistent with research on alcohol and cigarette purchase tasks, the MPT can be characterized with a latent two-factor structure. Thus, demand for marijuana appears to encompass distinct dimensions of price sensitivity and volumetric consumption, with differential relations to other aspects of marijuana motivation.

  8. Latent Trait Model Contributions to Criterion-Referenced Testing Technology.

    Science.gov (United States)

    1982-02-01

    levels of ability (ranging from very low to very high). The steps in the reserach were as follows: 1. Specify the characteristics of a "typical" pool...conventional testing methodologies displayed good fit to both of the latent trait models. The one-parameter model compared favorably with the three- parameter... Methodological developments: New directions for testing a!nd measurement (No. 4). San Francisco: Jossey-Bass, 1979. Haubleton, R. K. Advances in

  9. HYBRID INDIRECT SOLAR COOKER WITH LATENT HEAT STORAGE

    OpenAIRE

    Benazeer Hassan K. Ibrahim *, Victor Jose

    2016-01-01

    Solar cooking is the simplest, safest, most convenient way to cook food without consuming fuels or heating up the kitchen. All the conventional solar cooker designs have the disadvantage of inability to cook during off-shine and night hours.This disadvantage can be eliminated if the solar cooker is designed with thermal storage arrangement. In this paper, a hybrid solar cooker with evacuated tube collector and latent thermal storage unit and alternate electric heatingsource is simulated. The...

  10. Reversible enlargement of the hypophysis in clinically latent hypothyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Schuemichen, C.

    1982-12-01

    A case is reported, in which the combination of high TT/sub 3/- and FT/sub 4/ plasma levels, increased TSH basal secretion and enlargement of the pituitary gland did not reflect secondary hyperthyroidism, but was cuased by clinically latent hypothyroidism, probably due to thyroid hormone antibodies. High doses of thyroid hormones lowered the TSH and prolactin basal secretion, and reduced the enlargement of the pituitary gland.

  11. Reversible enlargement of the hypophysis in clinically latent hypothyroidism

    International Nuclear Information System (INIS)

    Schuemichen, C.

    1982-01-01

    A case is reported, in which the combination of high TT 3 - and FT 4 plasma levels, increased TSH basal secretion and enlargement of the pituitary gland did not reflect secondary hyperthyroidism, but was cuased by clinically latent hypothyroidism, probably due to thyroid hormone antibodies. High doses of thyroid hormones lowered the TSH and prolactin basal secretion, and reduced the enlargement of the pituitary gland. (orig.) [de

  12. Latent Space Embedding for Retrieval in Question-Answer Archives

    OpenAIRE

    Padmanabhan, Deepak; Garg, Dinesh; Shevade, Shirish

    2017-01-01

    Community-driven Question Answering (CQA) systems such as Yahoo! Answers have become valuable sources of reusable information. CQA retrieval enables usage of historical CQA archives to solve new questions posed by users. This task has received much recent attention, with methods building upon literature from translation models, topic models, and deep learning. In this paper, we devise a CQA retrieval technique, LASER-QA, that embeds question-answer pairs within a unified latent space preservi...

  13. Disintermediation and User-generated Content: A Latent Segmentation Analysis

    OpenAIRE

    Del Chiappa, Giacomo; Lorenzo-Romero, Carlota; Constantinides, Efthymios

    2014-01-01

    This research investigates the perceptions of different groups of consumers for and against the disintermediation of travel agencies also considering the relative power in influencing the tourist's choices exerted by user generated-content (UGC). A web-based survey is carried out in Spain and 961 complete questionnaires was obtained. A latent segmentation was applied on factors identified running an exploratory factor analysis on a list of 16 statements, the use and frequency of use of the In...

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

    Science.gov (United States)

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

    2012-08-01

    The objective of this study was to detect and characterize latent equine herpes virus (EHV)-1 and -4 from the submandibular (SMLN) and bronchial lymph (BLN) nodes, as well as from the trigeminal ganglia (TG) of 70 racing Thoroughbred horses submitted for necropsy following sustaining serious musculoskeletal injuries while racing. A combination of nucleic acid precipitation and pre-amplification steps was used to increase analytical sensitivity. Tissues were deemed positive for latent EHV-1 and/or -4 infection when found PCR positive for the corresponding glycoprotein B (gB) gene in the absence of detectable late structural protein gene (gB gene) mRNA. The EHV-1 genotype was also determined using a discriminatory real-time PCR assay targeting the DNA polymerase gene (ORF 30). Eighteen (25.7%) and 58 (82.8%) horses were PCR positive for the gB gene of EHV-1 and -4, respectively, in at least one of the three tissues sampled. Twelve horses were dually infected with EHV-1 and -4, two carried a latent neurotropic strain of EHV-1, six carried a non-neurotropic genotype of EHV-1 and 10 were dually infected with neurotropic and non-neurotropic EHV-1. The distribution of latent EHV-1 and -4 infection varied in the samples, with the TG found to be most commonly infected. Overall, non-neurotropic strains were more frequently detected than neurotropic strains, supporting the general consensus that non-neurotropic strains are more prevalent in horse populations, and hence the uncommon occurrence of equine herpes myeloencephalopathy. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Test de respiración única para la capacidad de difusión de monóxido de carbono (DLCO) y su interpretación en enfermedades autoinmunes. Aplicación en la práctica clínica -Segunda Parte-

    OpenAIRE

    Mora Alfonso, Sergio Alexander; Bello Gualtero, Juan Manuel; Londoño, John; Valle-Oñate, Rafael Raúl; Quintana, Gerardo

    2011-01-01

    El test de respiración única ha probado por si mismo ser una parte esencial del tamizaje de rutina de la función pulmonar, y de igual valor que la espirometría. A pesar de 100 años de investigación, aún no existe certeza sobre la relativa importancia de las membranas alveolo-capilares vs los eritrocitos como los pasos que sean delimitantes en el transporte global del monóxido de carbono del gas hacia la sangre, pero esto es solo un problema cuantitativo. La naturaleza esencial del test de DLC...

  16. [Latent Class Analysis of Gambling Activities among Korean Adolescents].

    Science.gov (United States)

    Kang, Kyonghwa; Kim, Hyeongsu; Park, Ae Ran; Kim, Hee Young; Lee, Kunsei

    2018-04-01

    The aim of this study is to identify the types of gambling among adolescents and provide basic prevention information regarding adolescents' gambling problems. Secondary data from representative national survey on 2015 Youth Gambling Problems of Korea Center on Gambling Problems were used. Using latent class analysis (LCA), 13 gambling types such as offline and online games of 14,011 adolescents were classified, and gambling experiences and characteristics were analyzed. The subgroups of adolescent gambling were identified as four latent classes: a rare group (84.5% of the sample), a risk group (1.0%), an offline group (11.9%), and an expanded group (2.6%). The types and characteristics of gambling among the latent classes differed. In the risk group, adolescents participated in online illegal sports betting and internet casino, and gambling time, gambling expenses, and the number of gambling types were higher than other groups. Gambling frequently occur among adolescent, and the subtypes of gambling did not reveal homogeneous characteristics. In order to prevent adolescent gambling problems, it is a necessary to develop tailored prevention intervention in the nursing field, which is appropriate to the characteristics of adolescent gambling group and can help with early identification. © 2018 Korean Society of Nursing Science.

  17. 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.

  18. Hidden Markov latent variable models with multivariate longitudinal data.

    Science.gov (United States)

    Song, Xinyuan; Xia, Yemao; Zhu, Hongtu

    2017-03-01

    Cocaine addiction is chronic and persistent, and has become a major social and health problem in many countries. Existing studies have shown that cocaine addicts often undergo episodic periods of addiction to, moderate dependence on, or swearing off cocaine. Given its reversible feature, cocaine use can be formulated as a stochastic process that transits from one state to another, while the impacts of various factors, such as treatment received and individuals' psychological problems on cocaine use, may vary across states. This article develops a hidden Markov latent variable model to study multivariate longitudinal data concerning cocaine use from a California Civil Addict Program. The proposed model generalizes conventional latent variable models to allow bidirectional transition between cocaine-addiction states and conventional hidden Markov models to allow latent variables and their dynamic interrelationship. We develop a maximum-likelihood approach, along with a Monte Carlo expectation conditional maximization (MCECM) algorithm, to conduct parameter estimation. The asymptotic properties of the parameter estimates and statistics for testing the heterogeneity of model parameters are investigated. The finite sample performance of the proposed methodology is demonstrated by simulation studies. The application to cocaine use study provides insights into the prevention of cocaine use. © 2016, The International Biometric Society.

  19. Discriminative latent models for recognizing contextual group activities.

    Science.gov (United States)

    Lan, Tian; Wang, Yang; Yang, Weilong; Robinovitch, Stephen N; Mori, Greg

    2012-08-01

    In this paper, we go beyond recognizing the actions of individuals and focus on group activities. This is motivated from the observation that human actions are rarely performed in isolation; the contextual information of what other people in the scene are doing provides a useful cue for understanding high-level activities. We propose a novel framework for recognizing group activities which jointly captures the group activity, the individual person actions, and the interactions among them. Two types of contextual information, group-person interaction and person-person interaction, are explored in a latent variable framework. In particular, we propose three different approaches to model the person-person interaction. One approach is to explore the structures of person-person interaction. Differently from most of the previous latent structured models, which assume a predefined structure for the hidden layer, e.g., a tree structure, we treat the structure of the hidden layer as a latent variable and implicitly infer it during learning and inference. The second approach explores person-person interaction in the feature level. We introduce a new feature representation called the action context (AC) descriptor. The AC descriptor encodes information about not only the action of an individual person in the video, but also the behavior of other people nearby. The third approach combines the above two. Our experimental results demonstrate the benefit of using contextual information for disambiguating group activities.

  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%). © 2010 American Academy of Forensic Sciences.

  1. Factores asociados a la infección tuberculosa latente en los contactos de pacientes afectados

    Directory of Open Access Journals (Sweden)

    Miquel Alsedà

    2004-04-01

    Full Text Available Fundamento: Una vez obtenidas unas cifras aceptables en la identificación y el tratamiento de los enfermos tuberculosos, se plantea una intervención para evitar la aparición de nuevos casos. Las personas con una infección tuberculosa latente (ITL reciente tienen un mayor riesgo de desarrollar una enfermedad tuberculosa. El objetivo de este estudio es evaluar la prevalencia de ITL y sus factores asociados en los contactos de pacientes tuberculosos. Métodos: Se estudiaron los contactos de estos pacientes examinados en el Centro de Prevención y Control de la Tuberculosis de Lleida en el período 1991-1997. Se recogieron factores asociados con el caso índice (demográficos, radiográficos, bacteriológicos y terapéuticos y el resultado de la prueba de la tuberculina en los contactos y sus datos demográficos. También se recogieron datos del caso índice relacionados con la infección por el VIH, el uso de drogas por vía parenteral y el consumo excesivo de alcohol. Como medida de asociación, se calcularon las odds ratio (OR crudas y ajustadas (ORa. Resultados: La prevalencia global de ITL en los contactos fue del 36,1% (780 de 2.161. En el análisis multivariante se detectó una mayor frecuencia de ITL en los contactos mayores de 14 años (ORa = 3,34; intervalo de confianza [IC] del 95%, 2,51-4,45, en los convivientes (ORa = 1,96; IC del 95%, 1,59-2,42, en los contactos de caso índice con una localización pulmonar de la enfermedad (ORa = 1,54; IC del 95%, 1,01-2,35, en los de caso índice con baciloscopia positiva en las muestras respiratorias (ORa = 1,51; IC del 95%, 1,15-1,99, en los de caso índice con patrón de cavitaciones en la radiografía de tórax (ORa = 1,27; IC del 95%, 1,01-1,61 y en los de casos índice con demora en el inicio del tratamiento (ORa = 1,31; IC del 95%, 1,05-1,62. Conclusiones: La prevalencia global de ITL en los contactos de enfermos tuberculosos es elevada. Entre los factores estudiados, la demora en el

  2. Latent class factor and cluster models, bi-plots and tri-plots and related graphical displays

    NARCIS (Netherlands)

    Magidson, J.; Vermunt, J.K.

    2001-01-01

    We propose an alternative method of conducting exploratory latent class analysis that utilizes latent class factor models, and compare it to the more traditional approach based on latent class cluster models. We show that when formulated in terms of R mutually independent, dichotomous latent

  3. Latent fingermark development using low-vacuum vaporization of ninhydrin.

    Science.gov (United States)

    Chen, Chun-Chieh; Yang, Chao-Kai; Liao, Jeh-Shane; Wang, Sheng-Meng

    2015-12-01

    The vacuum technique is a method of vaporizing a solid material to its gas phase, helping deposit reagents gently on target surfaces to develop latent fingermarks. However, this application is rarely reported in the literature. In this study, a homemade fume hood with a built-in vacuum control system and programmable heating system designed by the Taiwan Criminal Investigation Bureau is introduced. Factors that affect the instrument's performance in developing fingermarks are discussed, including the quantity of chemicals for vaporization, heating program arrangement, and paper of different materials. The results show that fingermarks are effectively developed by vaporizing solid ninhydrin. This would be an alternative application in selecting a solvent-free method for protecting the environment and reducing health hazards in the lab. In terms of the heating program, the result indicates that under a low-vacuum condition (50 mTorr), 80-90 °C is a suitable temperature range for ninhydrin vaporization, allowing ninhydrin to be vaporized without bumping and waste. In terms of the performance on different material papers, this instrument demonstrates its capacity by developing latent fingermarks on thermal paper without discoloration or damaging the original writing, and the same results are also observed on Taiwan and United States banknotes. However, a coherent result could be hardly obtained using the same vaporization setting because different banknotes have their own surface features and water absorption ability or other unique factors may influence the effect of ninhydrin deposition. This study provides a reliable application for developing latent fingermarks without using solvents, and it is also expected to contribute to environmental protection along with the trend of green chemistry technology. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Latent cooling and microphysics effects in deep convection

    Science.gov (United States)

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

    2016-11-01

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

  5. Perturbative corrections for approximate inference in gaussian latent variable models

    DEFF Research Database (Denmark)

    Opper, Manfred; Paquet, Ulrich; Winther, Ole

    2013-01-01

    Expectation Propagation (EP) provides a framework for approximate inference. When the model under consideration is over a latent Gaussian field, with the approximation being Gaussian, we show how these approximations can systematically be corrected. A perturbative expansion is made of the exact b...... illustrate on tree-structured Ising model approximations. Furthermore, they provide a polynomial-time assessment of the approximation error. We also provide both theoretical and practical insights on the exactness of the EP solution. © 2013 Manfred Opper, Ulrich Paquet and Ole Winther....

  6. Amatchmethod Based on Latent Semantic Analysis for Earthquakehazard Emergency Plan

    Science.gov (United States)

    Sun, D.; Zhao, S.; Zhang, Z.; Shi, X.

    2017-09-01

    The structure of the emergency plan on earthquake is complex, and it's difficult for decision maker to make a decision in a short time. To solve the problem, this paper presents a match method based on Latent Semantic Analysis (LSA). After the word segmentation preprocessing of emergency plan, we carry out keywords extraction according to the part-of-speech and the frequency of words. Then through LSA, we map the documents and query information to the semantic space, and calculate the correlation of documents and queries by the relation between vectors. The experiments results indicate that the LSA can improve the accuracy of emergency plan retrieval efficiently.

  7. Latent spatial models and sampling design for landscape genetics

    Science.gov (United States)

    Hanks, Ephraim M.; Hooten, Mevin B.; Knick, Steven T.; Oyler-McCance, Sara J.; Fike, Jennifer A.; Cross, Todd B.; Schwartz, Michael K.

    2016-01-01

    We propose a spatially-explicit approach for modeling genetic variation across space and illustrate how this approach can be used to optimize spatial prediction and sampling design for landscape genetic data. We propose a multinomial data model for categorical microsatellite allele data commonly used in landscape genetic studies, and introduce a latent spatial random effect to allow for spatial correlation between genetic observations. We illustrate how modern dimension reduction approaches to spatial statistics can allow for efficient computation in landscape genetic statistical models covering large spatial domains. We apply our approach to propose a retrospective spatial sampling design for greater sage-grouse (Centrocercus urophasianus) population genetics in the western United States.

  8. AMATCHMETHOD BASED ON LATENT SEMANTIC ANALYSIS FOR EARTHQUAKEHAZARD EMERGENCY PLAN

    Directory of Open Access Journals (Sweden)

    D. Sun

    2017-09-01

    Full Text Available The structure of the emergency plan on earthquake is complex, and it’s difficult for decision maker to make a decision in a short time. To solve the problem, this paper presents a match method based on Latent Semantic Analysis (LSA. After the word segmentation preprocessing of emergency plan, we carry out keywords extraction according to the part-of-speech and the frequency of words. Then through LSA, we map the documents and query information to the semantic space, and calculate the correlation of documents and queries by the relation between vectors. The experiments results indicate that the LSA can improve the accuracy of emergency plan retrieval efficiently.

  9. Towards an HIV-1 cure: measuring the latent reservoir.

    Science.gov (United States)

    Bruner, Katherine M; Hosmane, Nina N; Siliciano, Robert F

    2015-04-01

    The latent reservoir (LR) of HIV-1 in resting memory CD4(+) T cells serves as a major barrier to curing HIV-1 infection. While many PCR- and culture-based assays have been used to measure the size of the LR, correlation between results of different assays is poor and recent studies indicate that no available assay provides an accurate measurement of reservoir size. The discrepancies between assays are a hurdle to clinical trials that aim to measure the efficacy of HIV-1 eradication strategies. Here we describe the advantages and disadvantages of various approaches to measuring the LR. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Manifestaciones mucocutáneas del liquen plano: Revisión bibliográfica

    Directory of Open Access Journals (Sweden)

    Orlando L Rodríguez Calzadilla

    2002-08-01

    Full Text Available El liquen plano es una enfermedad de la piel y las mucosas que aparece con relativa frecuencia. Las lesiones de las membranas mucosas son de color blanquecino y persisten durante años después que desaparecen las lesiones de la piel. El odontólogo la diagnostica con frecuencia por mostrar sus primeros síntomas y signos en la mucosa bucal. Se caracteriza por la aparición de un infiltrado inflamatorio en banda y degeneración vacuolizante de la capa basal del epitelio, hechos que hacen pensar en una reacción autoinmune celular como base del proceso. Dos fenómenos importantes se describen en la respuesta inmunitaria celular: la expresión de antígenos de histocompatibilidad leucocitaria (HLA-DR y la molécula de adhesión intercelular-1 (ICAM-1. Se han reportado casos de transformación maligna en el liquen plano eritematoso o erosivo. El pronóstico del liquen plano es satisfactorio, cura en un tiempo promedio de 2 a 6 meses, pero existen casos cuya evolución se hace crónica y permanece durante años. Se realizó esta revisión bibliográfica con el objetivo de actualizar sobre este tema a estudiantes, estomatólogos y médicos en nuestra provincia.Lichen planus is a skin and mucous disease that is relatively frequent. Mucous membrane lesions are white-coloured and persisted for years after the skin lesions have disappeared. The odontologist often diagnoses it because its first symptoms and signs occurred in the oral mucous membrane. It is characterized by a band inflammatory infiltrate and vacuolizing degeneration of the basal layer of epithelium, events that might indicate an autoimmune cell reaction as a basis of the process. Two important phenomena are described in the immune cell response: the leukocyte histocompatibility antigen expression (HLA-DR and intercellular adhesion molecule-1 (ICAM-1. There have been reported cases of malignant transformation in erythematous or erosive lichen planus. The prognosis of lichen planus is

  11. Il dono del racconto

    DEFF Research Database (Denmark)

    Polito, Paola

    1998-01-01

    L'articolo indaga a vari livelli strutturali del romanzo "Il coraggio del pettirosso" (rete metaforica, dialogismo diegetico, dialogismo come fenomeno di voce, strategie discorsive messe in atto dalla voce narrante, stile colloquiale) la complessa realizzazione testuale del genere narrativo...

  12. Perbandingan Hasil Deteksi Plagiarisme Dokumen dengan Metode Jaro-Winkler Distance dan Metode Latent Semantic Analysis

    Directory of Open Access Journals (Sweden)

    Tinaliah Tinaliah

    2018-01-01

    Full Text Available Various methods are applied in the application of plagiarism detection to help check the similarity of a document. Jaro-Winkler Distance can measure the distance between two strings. However, this method basically depends on the position of the word. Latent Semantic Analysis emphasizes the words contained in the document regardless of its linguistic character. This study compares the results of plagiarism detection using the Jaro-Winkler Distance and the Latent Semantic Analysis method. From comparing results of  Jaro-Winkler Distance method and Latent Semantic Analysis method, Jaro-Winkler Distance method is better than Latent Semantic Analysis method if using the same test data. Jaro-Winkler Distance method will give plagiarism result 100% and Latent Semantic Analysis method will give plagiarism result 97,14%. Beragam metode diterapkan dalam aplikasi deteksi plagiarisme untuk membantu mengecek tingkat kesamaan sebuah dokumen. Metode Jaro-Winkler Distance dapat mengukur kesamaan antara dua buah string dan sangat bergantung pada urutan atau posisi kata. Latent Semantic Analysis mementingkan kata-kata yang terkandung di dalam dokumen tanpa memperhatikan karakter linguistiknya. Penelitian ini melakukan perbandingan hasil deteksi plagiarisme dengan menggunakan metode Jaro-Winkler Distance dan metode Latent Semantic Analysis. Hasil pendeteksian plagiarisme dokumen menggunakan metode Jaro-Winkler Distance memberikan hasil yang lebih baik daripada metode Latent Semantic Analysis, yaitu jika data yang dibandingkan sama persis maka akan menghasilkan nilai plagiat sebesar 100%, sedangkan metode Latent Semantic Analysis menghasilkan nilai plagiat sebesar 97,14%.

  13. A quantitative analysis on latent heat of an aqueous binary mixture.

    Science.gov (United States)

    Han, Bumsoo; Choi, Jeung Hwan; Dantzig, Jonathan A; Bischof, John C

    2006-02-01

    The latent heat during phase change of water-NaCl binary mixture was measured using a differential scanning calorimeter, and the magnitude for two distinct phase change events, water/ice and eutectic phase change, were analyzed considering the phase change characteristics of a binary mixture. During the analysis, the latent heat associated with each event was calculated by normalizing the amount of each endothermic peak with only the amount of sample participating in each event estimated from the lever rule for the phase diagram. The resulting latent heat of each phase change measured is 303.7 +/- 2.5 J/g for water/ice phase change, and 233.0 +/- 1.6 J/g for eutectic phase change, respectively regardless of the initial concentration of mixture. Although the latent heats of water/ice phase change in water-NaCl mixtures are closely correlated, further study is warranted to investigate the reason for smaller latent heat of water/ice phase change than that in pure water (335 J/g). The analysis using the lever rule was extended to estimate the latent heat of dihydrate as 115 J/g with the measured eutectic and water/ice latent heat values. This new analysis based on the lever rule will be useful to estimate the latent heat of water-NaCl mixtures at various concentrations, and may become a framework for more general analysis of latent heat of various biological solutions.

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

    Science.gov (United States)

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

    2015-04-01

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

  15. Shallow and Deep Latent Heating Modes Over Tropical Oceans Observed with TRMM PR Spectral Latent Heating Data

    Science.gov (United States)

    Takayabu, Yukari N.; Shige, Shoichi; Tao, Wei-Kuo; Hirota, Nagio

    2010-01-01

    The global hydrological cycle is central to the Earth's climate system, with rainfall and the physics of its formation acting as the key links in the cycle. Two-thirds of global rainfall occurs in the Tropics. Associated with this rainfall is a vast amount of heat, which is known as latent heat. It arises mainly due to the phase change of water vapor condensing into liquid droplets; three-fourths of the total heat energy available to the Earth's atmosphere comes from tropical rainfall. In addition, fresh water provided by tropical rainfall and its variability exerts a large impact upon the structure and motions of the upper ocean layer. Three-dimensional distributions of latent heating estimated from Tropical Rainfall Measuring Mission Precipitation Radar (TRMM PR)utilizing the Spectral Latent Heating (SLH) algorithm are analyzed. Mass-weighted and vertically integrated latent heating averaged over the tropical oceans is estimated as approx.72.6 J/s (approx.2.51 mm/day), and that over tropical land is approx.73.7 J/s (approx.2.55 mm/day), for 30degN-30degS. It is shown that non-drizzle precipitation over tropical and subtropical oceans consists of two dominant modes of rainfall systems, deep systems and congestus. A rough estimate of shallow mode contribution against the total heating is about 46.7 % for the average tropical oceans, which is substantially larger than 23.7 % over tropical land. While cumulus congestus heating linearly correlates with the SST, deep mode is dynamically bounded by large-scale subsidence. It is notable that substantial amount of rain, as large as 2.38 mm day-1 in average, is brought from congestus clouds under the large-scale subsiding circulation. It is also notable that even in the region with SST warmer than 28 oC, large-scale subsidence effectively suppresses the deep convection, remaining the heating by congestus clouds. Our results support that the entrainment of mid-to-lower-tropospheric dry air, which accompanies the large

  16. Mining Key Skeleton Poses with Latent SVM for Action Recognition

    Directory of Open Access Journals (Sweden)

    Xiaoqiang Li

    2017-01-01

    Full Text Available Human action recognition based on 3D skeleton has become an active research field in recent years with the recently developed commodity depth sensors. Most published methods analyze an entire 3D depth data, construct mid-level part representations, or use trajectory descriptor of spatial-temporal interest point for recognizing human activities. Unlike previous work, a novel and simple action representation is proposed in this paper which models the action as a sequence of inconsecutive and discriminative skeleton poses, named as key skeleton poses. The pairwise relative positions of skeleton joints are used as feature of the skeleton poses which are mined with the aid of the latent support vector machine (latent SVM. The advantage of our method is resisting against intraclass variation such as noise and large nonlinear temporal deformation of human action. We evaluate the proposed approach on three benchmark action datasets captured by Kinect devices: MSR Action 3D dataset, UTKinect Action dataset, and Florence 3D Action dataset. The detailed experimental results demonstrate that the proposed approach achieves superior performance to the state-of-the-art skeleton-based action recognition methods.

  17. Latent hardening size effect in small-scale plasticity

    Science.gov (United States)

    Bardella, Lorenzo; Segurado, Javier; Panteghini, Andrea; Llorca, Javier

    2013-07-01

    We aim at understanding the multislip behaviour of metals subject to irreversible deformations at small-scales. By focusing on the simple shear of a constrained single-crystal strip, we show that discrete Dislocation Dynamics (DD) simulations predict a strong latent hardening size effect, with smaller being stronger in the range [1.5 µm, 6 µm] for the strip height. We attempt to represent the DD pseudo-experimental results by developing a flow theory of Strain Gradient Crystal Plasticity (SGCP), involving both energetic and dissipative higher-order terms and, as a main novelty, a strain gradient extension of the conventional latent hardening. In order to discuss the capability of the SGCP theory proposed, we implement it into a Finite Element (FE) code and set its material parameters on the basis of the DD results. The SGCP FE code is specifically developed for the boundary value problem under study so that we can implement a fully implicit (Backward Euler) consistent algorithm. Special emphasis is placed on the discussion of the role of the material length scales involved in the SGCP model, from both the mechanical and numerical points of view.

  18. Latent hardening size effect in small-scale plasticity

    International Nuclear Information System (INIS)

    Bardella, Lorenzo; Panteghini, Andrea; Segurado, Javier; Llorca, Javier

    2013-01-01

    We aim at understanding the multislip behaviour of metals subject to irreversible deformations at small-scales. By focusing on the simple shear of a constrained single-crystal strip, we show that discrete Dislocation Dynamics (DD) simulations predict a strong latent hardening size effect, with smaller being stronger in the range [1.5 µm, 6 µm] for the strip height. We attempt to represent the DD pseudo-experimental results by developing a flow theory of Strain Gradient Crystal Plasticity (SGCP), involving both energetic and dissipative higher-order terms and, as a main novelty, a strain gradient extension of the conventional latent hardening. In order to discuss the capability of the SGCP theory proposed, we implement it into a Finite Element (FE) code and set its material parameters on the basis of the DD results. The SGCP FE code is specifically developed for the boundary value problem under study so that we can implement a fully implicit (Backward Euler) consistent algorithm. Special emphasis is placed on the discussion of the role of the material length scales involved in the SGCP model, from both the mechanical and numerical points of view. (paper)

  19. Surface latent heat flux as an earthquake precursor

    Directory of Open Access Journals (Sweden)

    S. Dey

    2003-01-01

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

  20. 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.

  1. 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.

  2. Latent period and temporal aspects of lung cancer among miners

    International Nuclear Information System (INIS)

    Sun Shiquan; Yang Xiaoou; Yang Lan; Meng Xianyu; Liu Shengen; You Zhanyun

    1984-01-01

    Data of lung cancer happened in the miners of this reported mine area is of great value to investigate the temporal aspects of miner's lung cancer, owing to its plenty of cases, longterm follow up and mining as child miners in early years before liberation of China. This preliminary analysis showed that the induction-latent period increased with the decrease of age at the year-of-first-employment in this mine and the protraction of follow up. In other words, even they were exposed since childhood, the excess of lung cancer never appeared until certain age for carcinogenesis. Therefore, the long-term follow up and comprehensive analysis of induction-latent period, underground duration-of-employment, time and age at start of mining would be helpful to properly estimating risk level, discovering the cause and predicting the trend of lung cancer incidence. There is no evidence to show whether child miners are more sensitive than adult miners working at the same exposure conditions

  3. 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.

  4. Partial Granger causality--eliminating exogenous inputs and latent variables.

    Science.gov (United States)

    Guo, Shuixia; Seth, Anil K; Kendrick, Keith M; Zhou, Cong; Feng, Jianfeng

    2008-07-15

    Attempts to identify causal interactions in multivariable biological time series (e.g., gene data, protein data, physiological data) can be undermined by the confounding influence of environmental (exogenous) inputs. Compounding this problem, we are commonly only able to record a subset of all related variables in a system. These recorded variables are likely to be influenced by unrecorded (latent) variables. To address this problem, we introduce a novel variant of a widely used statistical measure of causality--Granger causality--that is inspired by the definition of partial correlation. Our 'partial Granger causality' measure is extensively tested with toy models, both linear and nonlinear, and is applied to experimental data: in vivo multielectrode array (MEA) local field potentials (LFPs) recorded from the inferotemporal cortex of sheep. Our results demonstrate that partial Granger causality can reveal the underlying interactions among elements in a network in the presence of exogenous inputs and latent variables in many cases where the existing conditional Granger causality fails.

  5. The relevance of security: A latent domain of attachment relationships.

    Science.gov (United States)

    Mannarini, Stefania; Boffo, Marilisa

    2014-02-01

    In the present study an adult attachment dimension, latent to the constructs of security, anxiety, and avoidance, was hypothesized, wherein security was expected to occupy the most relevant position. Furthermore, the reciprocal functioning of attachment constructs and their interactions with self-esteem were explored. Four hundreds and thirty-four Italian university students responded to two adult attachment questionnaires (Attachment Style Questionnaire and Adult Attachment Questionnaire) and to the Rosenberg Self-esteem scale. A Many-Facet Rasch Measurement modeling approach was adopted. The main results can be summarized as follows: (a) security, anxiety, and avoidance are nested under one latent attachment dimension; (b) security occupies the most prominent position on the dimension; (c) security is positively associated with a moderate level of attachment anxiety and negatively related to avoidance; and (d) a positive interaction between self-esteem and security, and a negative relation between self-esteem and anxiety, were detected. Theoretical, clinical, and empirical implications of the results are further discussed. © 2013 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  6. Inverse Ising problem in continuous time: A latent variable approach

    Science.gov (United States)

    Donner, Christian; Opper, Manfred

    2017-12-01

    We consider the inverse Ising problem: the inference of network couplings from observed spin trajectories for a model with continuous time Glauber dynamics. By introducing two sets of auxiliary latent random variables we render the likelihood into a form which allows for simple iterative inference algorithms with analytical updates. The variables are (1) Poisson variables to linearize an exponential term which is typical for point process likelihoods and (2) Pólya-Gamma variables, which make the likelihood quadratic in the coupling parameters. Using the augmented likelihood, we derive an expectation-maximization (EM) algorithm to obtain the maximum likelihood estimate of network parameters. Using a third set of latent variables we extend the EM algorithm to sparse couplings via L1 regularization. Finally, we develop an efficient approximate Bayesian inference algorithm using a variational approach. We demonstrate the performance of our algorithms on data simulated from an Ising model. For data which are simulated from a more biologically plausible network with spiking neurons, we show that the Ising model captures well the low order statistics of the data and how the Ising couplings are related to the underlying synaptic structure of the simulated network.

  7. Latent heat transport and microlayer evaporation in nucleate boiling

    International Nuclear Information System (INIS)

    Jawurek, H.H.

    1977-08-01

    Part 1 of this work provides a broad overview and, where possible, a quantitative assessment of the complex physical processes which together constitute the mechanism of nucleate boiling heat transfer. It is shown that under a wide range of conditions the primary surface-to-liquid heat flows within an area of bubble influence are so redistributed as to manifest themselves predominantly as latent heat transport, that is, as vaporisation into attached bubbles. Part 2 deals in greater detail with one of the component processes of latent heat transport, namely microlayer evaporation. A literature review reveals the need for synchronised records of microlayer geometry versus time and of normal bubble growth and departure. An apparatus developed to provide such records is described. High-speed cine interference photography from beneath and through a transparent heating surface provided details of microlayer geometry and an image reflection system synchronised these records with the bubble profile views. Results are given for methanol and ethanol boiling at sub-atmospheric pressures and at various heat fluxes and bulk subcoolings. In all cases it is found that microlayers were of sub-micron thickness, that microlayer thinning was restricted to the inner layer edge (with the thickness elsewhere remaining constant or increasing with time) and that the contribution of this visible evaporation to the total vapour flow into bubbles was negligible. The observation of thickening towards the outer microlayer edge, however, demonstrates that a liquid replenishment flow occurred simultaneously with the evaporation process

  8. Dissociative features in posttraumatic stress disorder: A latent profile analysis.

    Science.gov (United States)

    Műllerová, Jana; Hansen, Maj; Contractor, Ateka A; Elhai, Jon D; Armour, Cherie

    2016-09-01

    The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) characterizes the dissociative subtype of posttraumatic stress disorder (PTSD) in terms of the individual meeting the criteria for PTSD and additionally reporting symptoms of depersonalization and/or derealization. The current study aimed to examine whether a dissociative PTSD profile may include alternative features of dissociation and whether it could be differentiated from a nondissociative PTSD profile on certain psychopathologies and demographics. Data from 309 trauma-exposed participants, collected through Amazon Mechanical Turk, were subjected to latent profile analysis. Regression analyses were used to examine the predictors of latent classes. Three discrete profiles named Baseline, PTSD, and Dissociative profile were uncovered. All examined features of dissociation were significantly elevated in the Dissociative profile. Anxiety, male sex, being employed, and having a minority racial background significantly predicted the Dissociative profile relative to the PTSD profile. The study points to the importance of alternative symptoms of dissociation in the dissociative PTSD subtype beyond the symptoms of depersonalization and derealization. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  9. Latent uncertainties of the precalculated track Monte Carlo method

    International Nuclear Information System (INIS)

    Renaud, Marc-André; Seuntjens, Jan; Roberge, David

    2015-01-01

    Purpose: While significant progress has been made in speeding up Monte Carlo (MC) dose calculation methods, they remain too time-consuming for the purpose of inverse planning. To achieve clinically usable calculation speeds, a precalculated Monte Carlo (PMC) algorithm for proton and electron transport was developed to run on graphics processing units (GPUs). The algorithm utilizes pregenerated particle track data from conventional MC codes for different materials such as water, bone, and lung to produce dose distributions in voxelized phantoms. While PMC methods have been described in the past, an explicit quantification of the latent uncertainty arising from the limited number of unique tracks in the pregenerated track bank is missing from the paper. With a proper uncertainty analysis, an optimal number of tracks in the pregenerated track bank can be selected for a desired dose calculation uncertainty. Methods: Particle tracks were pregenerated for electrons and protons using EGSnrc and GEANT4 and saved in a database. The PMC algorithm for track selection, rotation, and transport was implemented on the Compute Unified Device Architecture (CUDA) 4.0 programming framework. PMC dose distributions were calculated in a variety of media and compared to benchmark dose distributions simulated from the corresponding general-purpose MC codes in the same conditions. A latent uncertainty metric was defined and analysis was performed by varying the pregenerated track bank size and the number of simulated primary particle histories and comparing dose values to a “ground truth” benchmark dose distribution calculated to 0.04% average uncertainty in voxels with dose greater than 20% of D max . Efficiency metrics were calculated against benchmark MC codes on a single CPU core with no variance reduction. Results: Dose distributions generated using PMC and benchmark MC codes were compared and found to be within 2% of each other in voxels with dose values greater than 20% of the

  10. Latent uncertainties of the precalculated track Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Renaud, Marc-André; Seuntjens, Jan [Medical Physics Unit, McGill University, Montreal, Quebec H3G 1A4 (Canada); Roberge, David [Département de radio-oncologie, Centre Hospitalier de l’Université de Montréal, Montreal, Quebec H2L 4M1 (Canada)

    2015-01-15

    Purpose: While significant progress has been made in speeding up Monte Carlo (MC) dose calculation methods, they remain too time-consuming for the purpose of inverse planning. To achieve clinically usable calculation speeds, a precalculated Monte Carlo (PMC) algorithm for proton and electron transport was developed to run on graphics processing units (GPUs). The algorithm utilizes pregenerated particle track data from conventional MC codes for different materials such as water, bone, and lung to produce dose distributions in voxelized phantoms. While PMC methods have been described in the past, an explicit quantification of the latent uncertainty arising from the limited number of unique tracks in the pregenerated track bank is missing from the paper. With a proper uncertainty analysis, an optimal number of tracks in the pregenerated track bank can be selected for a desired dose calculation uncertainty. Methods: Particle tracks were pregenerated for electrons and protons using EGSnrc and GEANT4 and saved in a database. The PMC algorithm for track selection, rotation, and transport was implemented on the Compute Unified Device Architecture (CUDA) 4.0 programming framework. PMC dose distributions were calculated in a variety of media and compared to benchmark dose distributions simulated from the corresponding general-purpose MC codes in the same conditions. A latent uncertainty metric was defined and analysis was performed by varying the pregenerated track bank size and the number of simulated primary particle histories and comparing dose values to a “ground truth” benchmark dose distribution calculated to 0.04% average uncertainty in voxels with dose greater than 20% of D{sub max}. Efficiency metrics were calculated against benchmark MC codes on a single CPU core with no variance reduction. Results: Dose distributions generated using PMC and benchmark MC codes were compared and found to be within 2% of each other in voxels with dose values greater than 20% of

  11. 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.

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

    Hosmane, Nina N; Kwon, Kyungyoon J; Bruner, Katherine M; Capoferri, Adam A; Beg, Subul; Rosenbloom, Daniel I S; Keele, Brandon F; Ho, Ya-Chi; Siliciano, Janet D; Siliciano, Robert F

    2017-04-03

    A latent reservoir for HIV-1 in resting CD4 + T lymphocytes precludes cure. Mechanisms underlying reservoir stability are unclear. Recent studies suggest an unexpected degree of infected cell proliferation in vivo. T cell activation drives proliferation but also reverses latency, resulting in productive infection that generally leads to cell death. In this study, we show that latently infected cells can proliferate in response to mitogens without producing virus, generating progeny cells that can release infectious virus. Thus, assays relying on one round of activation underestimate reservoir size. Sequencing of independent clonal isolates of replication-competent virus revealed that 57% had env sequences identical to other isolates from the same patient. Identity was confirmed by full-genome sequencing and was not attributable to limited viral diversity. Phylogenetic and statistical analysis suggested that identical sequences arose from in vivo proliferation of infected cells, rather than infection of multiple cells by a dominant viral species. The possibility that much of the reservoir arises by cell proliferation presents challenges to cure. © 2017 Hosmane et al.

  14. Interferon-gamma release assay for the diagnosis of latent tuberculosis infection: A latent-class analysis.

    Directory of Open Access Journals (Sweden)

    Tan N Doan

    Full Text Available Accurate diagnosis and subsequent treatment of latent tuberculosis infection (LTBI is essential for TB elimination. However, the absence of a gold standard test for diagnosing LTBI makes assessment of the true prevalence of LTBI and the accuracy of diagnostic tests challenging. Bayesian latent class models can be used to make inferences about disease prevalence and the sensitivity and specificity of diagnostic tests using data on the concordance between tests. We performed the largest meta-analysis to date aiming to evaluate the performance of tuberculin skin test (TST and interferon-gamma release assays (IGRAs for LTBI diagnosis in various patient populations using Bayesian latent class modelling.Systematic search of PubMeb, Embase and African Index Medicus was conducted without date and language restrictions on September 11, 2017 to identify studies that compared the performance of TST and IGRAs for LTBI diagnosis. Two IGRA methods were considered: QuantiFERON-TB Gold In Tube (QFT-GIT and T-SPOT.TB. Studies were included if they reported 2x2 agreement data between TST and QFT-GIT or T-SPOT.TB. A Bayesian latent class model was developed to estimate the sensitivity and specificity of TST and IGRAs in various populations, including immune-competent adults, immune-compromised adults and children. A TST cut-off value of 10 mm was used for immune-competent subjects and 5 mm for immune-compromised individuals.A total of 157 studies were included in the analysis. In immune-competent adults, the sensitivity of TST and QFT-GIT were estimated to be 84% (95% credible interval [CrI] 82-85% and 52% (50-53%, respectively. The specificity of QFT-GIT was 97% (96-97% in non-BCG-vaccinated and 93% (92-94% in BCG-vaccinated immune-competent adults. The estimated figures for TST were 100% (99-100% and 79% (76-82%, respectively. T-SPOT.TB has comparable specificity (97% for both tests and better sensitivity (68% versus 52% than QFT-GIT in immune-competent adults

  15. Building latent class trees, with an application to a study of social capital

    NARCIS (Netherlands)

    van den Bergh, M.; Schmittmann, V.D.; Vermunt, J.K.

    2017-01-01

    Researchers use latent class (LC) analysis to derive meaningful clusters from sets of categorical variables. However, especially when the number of classes required to obtain a good fit is large, interpretation of the latent classes may not be straightforward. To overcome this problem, we propose an

  16. 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…

  17. Evaluation of HIV Risk Reduction and Intervention Programs via Latent Growth Model.

    Science.gov (United States)

    Wang, Jichuan; Siegal, Harvey A.; Falck, Russel S.; Carlson, Robert G.; Rahman, Ahmmed

    1999-01-01

    Demonstrates how the latent growth model can be applied to the evaluation of programs targeting HIV risk behavior among drug users. Multigroup piecewise latent growth models were fit to longitudinal data with three repeated response measures. Participants were 430 drug users and their sex partners. (SLD)

  18. A Latent Class Regression Analysis of Men's Conformity to Masculine Norms and Psychological Distress

    Science.gov (United States)

    Wong, Y. Joel; Owen, Jesse; Shea, Munyi

    2012-01-01

    How are specific dimensions of masculinity related to psychological distress in specific groups of men? To address this question, the authors used latent class regression to assess the optimal number of latent classes that explained differential relationships between conformity to masculine norms and psychological distress in a racially diverse…

  19. 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…

  20. How to get rid of W: a latent variables approach to modelling spatially lagged variables

    NARCIS (Netherlands)

    Folmer, H.; Oud, J.

    2008-01-01

    In this paper we propose a structural equation model (SEM) with latent variables to model spatial dependence. Rather than using the spatial weights matrix W, we propose to use latent variables to represent spatial dependence and spillover effects, of which the observed spatially lagged variables are

  1. How to get rid of W : a latent variables approach to modelling spatially lagged variables

    NARCIS (Netherlands)

    Folmer, Henk; Oud, Johan

    2008-01-01

    In this paper we propose a structural equation model (SEM) with latent variables to model spatial dependence. Rather than using the spatial weights matrix W, we propose to use latent variables to represent spatial dependence and spillover effects, of which the observed spatially lagged variables are

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

    Science.gov (United States)

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

    2003-01-01

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

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

    NARCIS (Netherlands)

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

    2004-01-01

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

  4. Cross-Informant Agreement on Child and Adolescent Withdrawn Behavior: A Latent Class Approach

    Science.gov (United States)

    Rubin, David H.; Althoff, Robert R.; Walkup, John T.; Hudziak, James J.

    2013-01-01

    Withdrawn behavior (WB) relates to many developmental outcomes, including pervasive developmental disorders, anxiety, depression, psychosis, personality disorders and suicide. No study has compared the latent profiles of different informants' reports on WB. This study uses multi-informant latent class analyses (LCA) of the child behavior checklist…

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

    Science.gov (United States)

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

    2015-01-01

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

  7. Primiparous women's preferences for care during a prolonged latent phase of labour.

    Science.gov (United States)

    Ängeby, Karin; Wilde-Larsson, Bodil; Hildingsson, Ingegerd; Sandin-Bojö, Ann-Kristin

    2015-10-01

    To investigate primiparous women's preferences for care during a prolonged latent phase of labour. A qualitative study based on focus groups and individual interviews and analysed with inductive content analysis. Sixteen primiparous women with a prolonged latent phase of labour >18 hours were interviewed in five focus groups (n = 11) or individually (n = 5). One main category emerged "Beyond normality - a need of individual adapted guidance in order to understand and manage an extended latent phase of labour" which covers the women's preferences during the prolonged latent phase. Five categories were generated from the data: "A welcoming manner and not being rejected", "Individually adapted care", "Important information which prepares for reality and coping", "Participation and need for feedback" and "Staying nearby the labour ward or being admitted for midwifery support". Women with a prolonged latent phase of labour sought to use their own resources, but their needs for professional support increased as time passed. A welcoming attitude from an available midwife during the latent phase created a feeling of security, and personally adapted care was perceived positively. Women with a prolonged latent phase of labour preferred woman-centred care. Midwives play an important role in supporting these women. Women's need for midwifery-support increases as the time spent in latent phase increases. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. 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…

  9. Modeling Psychological Attributes in Psychology – An Epistemological Discussion: Network Analysis vs. Latent Variables

    Science.gov (United States)

    Guyon, Hervé; Falissard, Bruno; Kop, Jean-Luc

    2017-01-01

    Network Analysis is considered as a new method that challenges Latent Variable models in inferring psychological attributes. With Network Analysis, psychological attributes are derived from a complex system of components without the need to call on any latent variables. But the ontological status of psychological attributes is not adequately defined with Network Analysis, because a psychological attribute is both a complex system and a property emerging from this complex system. The aim of this article is to reappraise the legitimacy of latent variable models by engaging in an ontological and epistemological discussion on psychological attributes. Psychological attributes relate to the mental equilibrium of individuals embedded in their social interactions, as robust attractors within complex dynamic processes with emergent properties, distinct from physical entities located in precise areas of the brain. Latent variables thus possess legitimacy, because the emergent properties can be conceptualized and analyzed on the sole basis of their manifestations, without exploring the upstream complex system. However, in opposition with the usual Latent Variable models, this article is in favor of the integration of a dynamic system of manifestations. Latent Variables models and Network Analysis thus appear as complementary approaches. New approaches combining Latent Network Models and Network Residuals are certainly a promising new way to infer psychological attributes, placing psychological attributes in an inter-subjective dynamic approach. Pragmatism-realism appears as the epistemological framework required if we are to use latent variables as representations of psychological attributes. PMID:28572780

  10. 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...

  11. Full Text or Abstract? : Examining Topic Coherence Scores Using Latent Dirichlet Allocation

    NARCIS (Netherlands)

    Syed, S.; Spruit, M.

    2017-01-01

    This paper assesses topic coherence and human topic ranking of uncovered latent topics from scientific publications when utilizing the topic model latent Dirichlet allocation (LDA) on abstract and full-text data. The coherence of a topic, used as a proxy for topic quality, is based on the

  12. 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.

  13. La superaci??n del modelo del ??ngel del hogar:

    OpenAIRE

    Hurtado Mu??oz, M??nica

    2012-01-01

    La Tesis Doctoral titulada "La superaci??n del modelo del "??ngel del hogar". Recuperaci??n de la escritora Leonor Canalejas y Fustegueras (1869-1945)" aborda, en primer lugar, un an??lisis sociol??gico de las circunstancias que rodearon a la mujer espa??ola en el cambio de siglo en el ??mbito social y educativo, en un intento de esclarecer las caracter??sticas propias del contexto en el que la mujer accede a la intelectualidad en general y a la literatura en particular. Esta parte concluye q...

  14. A Dynamic Compliance Cervix Phantom Robot for Latent Labor Simulation.

    Science.gov (United States)

    Luk, Michelle Jennifer; Lobb, Derek; Smith, James Andrew

    2018-05-09

    Physical simulation systems are commonly used in training of midwifery and obstetrics students, but none of these systems offers a dynamic compliance aspect that would make them more truly representative of cervix ripening. In this study, we introduce a unique soft robot phantom that simulates the cervix softening during the latent labor phase of birth. This proof-of-concept robotic phantom can be dilated by 1 cm and effaced by 35% through the application of a Foley catheter-like loading mechanism. Furthermore, psychophysics trials demonstrate how untrained subjects can identify hard and soft states of the phantom with specificities of 91% and 87%, respectively. Both results indicated the appropriateness for application of this soft robot technology to birth training simulators.

  15. 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.

  16. Obesogenic family types identified through latent profile analysis.

    Science.gov (United States)

    Martinson, Brian C; VazquezBenitez, Gabriela; Patnode, Carrie D; Hearst, Mary O; Sherwood, Nancy E; Parker, Emily D; Sirard, John; Pasch, Keryn E; Lytle, Leslie

    2011-10-01

    Obesity may cluster in families due to shared physical and social environments. This study aims to identify family typologies of obesity risk based on family environments. Using 2007-2008 data from 706 parent/youth dyads in Minnesota, we applied latent profile analysis and general linear models to evaluate associations between family typologies and body mass index (BMI) of youth and parents. Three typologies described most families with 18.8% "Unenriched/Obesogenic," 16.9% "Risky Consumer," and 64.3% "Healthy Consumer/Salutogenic." After adjustment for demographic and socioeconomic factors, parent BMI and youth BMI Z-scores were higher in unenriched/obesogenic families (BMI difference = 2.7, p typology. In contrast, parent BMI and youth BMI Z-scores were similar in the risky consumer families relative to those in healthy consumer/salutogenic type. We can identify family types differing in obesity risks with implications for public health interventions.

  17. Improving knowledge management systems with latent semantic analysis

    International Nuclear Information System (INIS)

    Sebok, A.; Plott, C.; LaVoie, N.

    2006-01-01

    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)

  18. The latent causal chain of industrial water pollution in China.

    Science.gov (United States)

    Miao, Xin; Tang, Yanhong; Wong, Christina W Y; Zang, Hongyu

    2015-01-01

    The purpose of this paper is to discover the latent causal chain of industrial water pollution in China and find ways to cure the want on discharge of toxic waste from industries. It draws evidences from the past pollution incidents in China. Through further digging the back interests and relations by analyzing representative cases, extended theory about loophole derivations and causal chain effect is drawn. This theoretical breakthrough reflects deeper causality. Institutional defect instead of human error is confirmed as the deeper reason of frequent outbreaks of water pollution incidents in China. Ways for collaborative environmental governance are proposed. This paper contributes to a better understanding about the deep inducements of industrial water pollution in China, and, is meaningful for ensuring future prevention and mitigation of environmental pollution. It illuminates multiple dimensions for collaborative environmental governance to cure the stubborn problem.

  19. Stereotype Threat and College Academic Performance: A Latent Variables Approach*

    Science.gov (United States)

    Owens, Jayanti; Massey, Douglas S.

    2013-01-01

    Stereotype threat theory has gained experimental and survey-based support in helping explain the academic underperformance of minority students at selective colleges and universities. Stereotype threat theory states that minority students underperform because of pressures created by negative stereotypes about their racial group. Past survey-based studies, however, are characterized by methodological inefficiencies and potential biases: key theoretical constructs have only been measured using summed indicators and predicted relationships modeled using ordinary least squares. Using the National Longitudinal Survey of Freshman, this study overcomes previous methodological shortcomings by developing a latent construct model of stereotype threat. Theoretical constructs and equations are estimated simultaneously from multiple indicators, yielding a more reliable, valid, and parsimonious test of key propositions. Findings additionally support the view that social stigma can indeed have strong negative effects on the academic performance of pejoratively stereotyped racial-minority group members, not only in laboratory settings, but also in the real world. PMID:23950616

  20. Identifying subgroups of patients using latent class analysis

    DEFF Research Database (Denmark)

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

    2017-01-01

    BACKGROUND: Heterogeneity in patients with low back pain (LBP) is well recognised and different approaches to subgrouping have been proposed. Latent Class Analysis (LCA) is a statistical technique that is increasingly being used to identify subgroups based on patient characteristics. However......, as LBP is a complex multi-domain condition, the optimal approach when using LCA is unknown. Therefore, this paper describes the exploration of two approaches to LCA that may help improve the identification of clinically relevant and interpretable LBP subgroups. METHODS: From 928 LBP patients consulting...... of statistical performance measures, qualitative evaluation of clinical interpretability (face validity) and a subgroup membership comparison. RESULTS: For the single-stage LCA, a model solution with seven patient subgroups was preferred, and for the two-stage LCA, a nine patient subgroup model. Both approaches...

  1. Latent Class Models in action: bridging social capital & Internet usage.

    Science.gov (United States)

    Neves, Barbara Barbosa; Fonseca, Jaime R S

    2015-03-01

    This paper explores how Latent Class Models (LCM) can be applied in social research, when the basic assumptions of regression models cannot be validated. We examine the usefulness of this method with data collected from a study on the relationship between bridging social capital and the Internet. Social capital is defined here as the resources that are potentially available in one's social ties. Bridging is a dimension of social capital, usually related to weak ties (acquaintances), and a source of instrumental resources such as information. The study surveyed a stratified random sample of 417 inhabitants of Lisbon, Portugal. We used LCM to create the variable bridging social capital, but also to estimate the relationship between bridging social capital and Internet usage when we encountered convergence problems with the logistic regression analysis. We conclude by showing a positive relationship between bridging and Internet usage, and by discussing the potential of LCM for social science research. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Residual Entropy, the Third Law and Latent Heat

    Directory of Open Access Journals (Sweden)

    Frank L. Lambert

    2008-09-01

    Full Text Available A novel thermodynamic treatment of residual entropy in crystals, involving the configurational partition function, is suggested, which is consistent with both classical and statistical thermodynamics. It relates residual entropy to the inherent latent heat which would be released upon cooling if the reversible path were available. The nature of this heat is that if the crystal possessing residual entropy freezes above its Boltzmann’s characteristic temperature of molecular alignment, the difference in energy between different molecular arrangements is overcome by the kT heat bath to form a nearly-ideal solution. However, upon cooling below this characteristic temperature, they would separate with a concomitant release of the corresponding energy, provided the reversible path were available.

  3. [Hypothyreodism. From the latent functional disorder up to coma].

    Science.gov (United States)

    Hintze, G; Derwahl, M

    2010-05-01

    An autoimmune thyroiditis represents the main reason of hypothyroidism, defined as a lack of thyroid hormone. This autoimmune process results in destruction of functioning thyroid follicles. While subclinical or latent hypothyroidism is defined on the basis of laboratory values (an elevation of TSH with normal peripheral hormone levels), the typical signs and symptoms are associated with hypothyroidism. In about 80% of cases antibodies against thyroid peroxidase can be measured, but only in about 40-50% of cases antibodies against thyroglobulin are detectable. If hypothyrodism has been diagnosed, substitution with levothyroxine should be initiated, with the therapeutic goal to decrease TSH level to the lower normal range. In cases of subclinical hypothyroidism, levothyroxine medication should be started in patients with a high TSH value, positive antibodies and/or the typical ultrasound of autoimmune thyroiditis. However, substitution with levothyroxine in any case of elevated TSH values should be avoided.

  4. Latent Toxicity of Endothall to Anadromous Salmonids During Seawater Challenge.

    Science.gov (United States)

    Courter, Lauren A; Garrison, Thomas M; Courter, Ian I

    2016-05-01

    Limited evidence exists on the latent effects of toxicant exposure on the seawater adaptability of anadromous salmon and steelhead. It is unclear whether such an effect exists for the widely used and relatively non-toxic herbicide endothall. Coho salmon, Oncorhynchus kisutch (coho), Chinook salmon, O. tshawytscha (Chinook), and anadromous rainbow trout, O. mykiss (steelhead) were subjected to a 10-day seawater challenge following freshwater treatments [0-12 mg acid equivalent (a.e)./L at 96 h]. Mean survival resulted in 82 % (n = 225), 84 % (n = 133), 90 % (n = 73) and 59 % (n = 147) survival for 0, 3-5, 6-8, and 9-12 mg a.e./L, respectively. Our results indicate a lower toxicity threshold compared with previously reported acute toxicity results, but higher compared with previous seawater challenge studies. We demonstrate the utility of the seawater challenge assay to accurately define toxic effects of pesticides on salmonids with complex life-histories.

  5. Computer assessment of interview data using latent semantic analysis.

    Science.gov (United States)

    Dam, Gregory; Kaufmann, Stefan

    2008-02-01

    Clinical interviews are a powerful method for assessing students' knowledge and conceptualdevelopment. However, the analysis of the resulting data is time-consuming and can create a "bottleneck" in large-scale studies. This article demonstrates the utility of computational methods in supporting such an analysis. Thirty-four 7th-grade student explanations of the causes of Earth's seasons were assessed using latent semantic analysis (LSA). Analyses were performed on transcriptions of student responses during interviews administered, prior to (n = 21) and after (n = 13) receiving earth science instruction. An instrument that uses LSA technology was developed to identify misconceptions and assess conceptual change in students' thinking. Its accuracy, as determined by comparing its classifications to the independent coding performed by four human raters, reached 90%. Techniques for adapting LSA technology to support the analysis of interview data, as well as some limitations, are discussed.

  6. Risk for latent and active tuberculosis in Germany.

    Science.gov (United States)

    Herzmann, Christian; Sotgiu, Giovanni; Bellinger, Oswald; Diel, Roland; Gerdes, Silke; Goetsch, Udo; Heykes-Uden, Helga; Schaberg, Tom; Lange, Christoph

    2017-06-01

    Few individuals that are latently infected with M. tuberculosis latent tuberculosis infection(LTBI) progress to active disease. We investigated risk factors for LTBI and active pulmonary tuberculosis (PTB) in Germany. Healthy household contacts (HHCs), health care workers (HCWs) exposed to M. tuberculosis and PTB patients were recruited at 18 German centres. Interferon-γ release assay (IGRA) testing was performed. LTBI risk factors were evaluated by comparing IGRA-positive with IGRA-negative contacts. Risk factors for tuberculosis were evaluated by comparing PTB patients with HHCs. From 2008-2014, 603 HHCs, 295 HCWs and 856 PTBs were recruited. LTBI was found in 34.5% of HHCs and in 38.9% of HCWs. In HCWs, care for coughing patients (p = 0.02) and longstanding nursing occupation (p = 0.04) were associated with LTBI. In HHCs, predictors for LTBI were a diseased partner (odds ratio 4.39), sexual contact to a diseased partner and substance dependency (all p < 0.001). PTB was associated with male sex, low body weight (p < 0.0001), alcoholism (15.0 vs 5.9%; p < 0.0001), glucocorticoid therapy (7.2 vs 2.0%; p = 0.004) and diabetes (7.8 vs. 4.0%; p = 0.04). No contact developed active tuberculosis within 2 years follow-up. Positive IGRA responses are frequent among exposed HHCs and HCWs in Germany and are poor predictors for the development of active tuberculosis.

  7. Heterogeneity of postpartum depression: a latent class analysis

    Science.gov (United States)

    2016-01-01

    Summary Background Maternal depression in the postpartum period confers substantial morbidity and mortality, but the definition of postpartum depression remains controversial. We investigated the heterogeneity of symptoms with the aim of identifying clinical subtypes of postpartum depression. Methods Data were aggregated from the international perinatal psychiatry consortium Postpartum Depression: Action Towards Causes and Treatment, which represents 19 institutions in seven countries. 17 912 unique subject records with phenotypic data were submitted. We applied latent class analyses in a two-tiered approach to assess the validity of empirically defined subtypes of postpartum depression. Tier one assessed heterogeneity in women with complete data on the Edinburgh postnatal depression scale (EPDS) and tier two in those with postpartum depression case status. Findings 6556 individuals were assessed in tier one and 4245 in tier two. A final model with three latent classes was optimum for both tiers. The most striking characteristics associated with postpartum depression were severity, timing of onset, comorbid anxiety, and suicidal ideation. Women in class 1 had the least severe symptoms (mean EPDS score 10·5), followed by those in class 2 (mean EPDS score 14·8) and those in class 3 (mean EPDS score 20·1). The most severe symptoms of postpartum depression were significantly associated with poor mood (mean EPDS score 20·1), increased anxiety, onset of symptoms during pregnancy, obstetric complications, and suicidal ideation. In class 2, most women (62%) reported symptom onset within 4 weeks postpartum and had more pregnancy complications than in other two classes (69% vs 67% in class 1 and 29% in class 3). Interpretation PPD seems to have several distinct phenotypes. Further assessment of PPD heterogeneity to identify more precise phenotypes will be important for future biological and genetic investigations. Funding Sources of funding are listed at the end of the

  8. Determining of migraine prognosis using latent growth mixture models.

    Science.gov (United States)

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

    2011-04-01

    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. 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. 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. Nausea, vomiting and photophobia were the most significant factors to identify developmental trajectories. The remission time was not the same for the severity, frequency, and duration of headache.

  9. Wallboard with Latent Heat Storage for Passive Solar Applications; TOPICAL

    International Nuclear Information System (INIS)

    Kedl, R.J.

    2001-01-01

    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

  10. Porphyromonas endodontalis reactivates latent Epstein-Barr virus.

    Science.gov (United States)

    Makino, K; Takeichi, O; Imai, K; Inoue, H; Hatori, K; Himi, K; Saito, I; Ochiai, K; Ogiso, B

    2018-06-01

    To determine whether Porphyromonas endodontalis can reactivate latent Epstein-Barr virus (EBV). The concentrations of short-chain fatty acids (SCFAs) in P. endodontalis culture supernatants were determined using high-performance liquid chromatography. A promoter region of BamHI fragment Z leftward open reading frame 1 (BZLF-1), which is a transcription factor that controls the EBV lytic cycle, was cloned into luciferase expression vectors. Then, the luciferase assay was performed using P. endodontalis culture supernatants. Histone acetylation using Daudi cells treated with P. endodontalis culture supernatants was examined using Western blotting. BZLF-1 mRNA and BamHI fragment Z EB replication activator (ZEBRA) protein were also detected quantitatively using real-time polymerase chain reaction (PCR) and Western blotting. Surgically removed periapical granulomas were examined to detect P. endodontalis, EBV DNA, and BZLF-1 mRNA expression using quantitative real-time PCR. Statistical analysis using Steel tests was performed. The concentrations of n-butyric acid in P. endodontalis culture supernatants were significantly higher than those of other SCFAs (P=0.0173). Using B-95-8-221 Luc cells treated with P. endodontalis culture supernatants, the luciferase assay demonstrated that P. endodontalis induced BZLF-1 expression. Hyperacetylation of histones was also observed with the culture supernatants. BZLF-1 mRNA and ZEBRA protein were expressed by Daudi cells in a dose-dependent manner after the treatment with P. endodontalis culture supernatants. P. endodontalis and BZLF-1 in periapical granulomas were also detected. The expression levels of BZLF-1 mRNA were similar to the numbers of P. endodontalis cells in each specimen. n-butyric acid produced by P. endodontalis reactivated latent EBV. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. LATENT STRUCTURE OF MOTOR ABILITIES AND SKILLS OF DEAF CHILDREN

    Directory of Open Access Journals (Sweden)

    Husnija Hasanbegović

    2012-04-01

    Full Text Available In this work surveys of latent motility abilities and skills of school children are shown. The sample for this survey was consisted of two subsamples. First one has consisted of deaf children N=29, and the second one has consisted hearing children of same age N=69. Subsamples of deaf is chosen according to model of applied sample, and subsample is chosen randomly, so two stages group sample N=90 has been created. After quantitative differences have been discovered between subsamples, hearing pupils have shown statistically better results at motility skills and techniques than deaf children and cumulative results have been subjected to inter correlation of variables. The target of using this method was determination of saturation of common variability through saturation of variables and their correlation by Ortoblique rotation for determination of latent information that are going to serve as practical guides at education and deaf children treatment, because of improvement of their motility abilities and skills according to hearing children. Three factors have been singled out as main preview of measurement on manifest variables. According to first review of measuring it has been established that at deaf children is needed to work on improving of physical abilities and mobility and then developed motility abilities and skills. Their information has been gained most probably by non system fluctuations as information about ability of balance maintaining which is most probably non dependable of motility abilities and skills as at deaf and hearing children too. According to this survey by entering the structure of measuring instrument it is possible to create programs for improving motility abilities and skills at deaf children.

  12. Flat plate solar air heater with latent heat storage

    Science.gov (United States)

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

    2017-02-01

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    Bi-partite networks are commonly modelled using latent class or latent feature models. Whereas the existing latent class models admit marginalization of parameters specifying the strength of interaction between groups, existing latent feature models do not admit analytical marginalization...... by the notion of community structure such that the edge density within groups is higher than between groups. Our model further assumes that entities can have different propensities of generating links in one of the modes. The proposed framework is contrasted on both synthetic and real bi-partite networks...... feature representations in bipartite networks provides a new framework for accounting for structure in bi-partite networks using binary latent feature representations providing interpretable representations that well characterize structure as quantified by link prediction....

  14. 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.

  15. poLCA: An R Package for Polytomous Variable Latent Class Analysis

    Directory of Open Access Journals (Sweden)

    Drew A. Linzer

    2011-08-01

    Full Text Available poLCA is a software package for the estimation of latent class and latent class regression models for polytomous outcome variables, implemented in the R statistical computing environment. Both models can be called using a single simple command line. The basic latent class model is a finite mixture model in which the component distributions are assumed to be multi-way cross-classification tables with all variables mutually independent. The latent class regression model further enables the researcher to estimate the effects of covariates on predicting latent class membership. poLCA uses expectation-maximization and Newton-Raphson algorithms to find maximum likelihood estimates of the model parameters.

  16. Latent Class Analysis of Criminal Social Identity in a Prison Sample

    Directory of Open Access Journals (Sweden)

    Boduszek Daniel

    2014-06-01

    Full Text Available This study aimed to examine the number of latent classes of criminal social identity that exist among male recidivistic prisoners. Latent class analysis was used to identify homogeneous groups of criminal social identity. Multinomial logistic regression was used to interpret the nature of the latent classes, or groups, by estimating the associationsto number of police arrests, recidivism, and violent offending while controlling for current age. The best fitting latent class model was a five-class solution: ‘High criminal social identity’ (17%, ‘High Centrality, Moderate Affect, Low Ties’ (21.7%, ‘Low Centrality, Moderate Affect, High Ties’ (13.3%,‘Low Cognitive, High Affect, Low Ties’ (24.6%, and ‘Low criminal social identity’ (23.4%. Each of the latent classes was predicted by differing external variables. Criminal social identity is best explained by five homogenous classes that display qualitative and quantitative differences.

  17. Consecuencias del desempleo en la salud mental de una muestra de jóvenes angoleños

    OpenAIRE

    José Manuel Tomás; Melchor Gutiérrez; Irene Fernández

    2017-01-01

    Entre los efectos del desempleo en la salud mental, destacan problemas de confianza, depresión y pérdida de recursos psicosociales. El objetivo es investigar las variables atenuantes del estrés sobre la salud mental en desempleados jóvenes angoleños mediante un modelo estructural con variables latentes. Se probaron los efectos del apoyo social, la resiliencia y las estrategias de afrontamiento sobre la salud mental, controlando por los efectos de ser económicamente suficiente. Para poner a ...

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

    NARCIS (Netherlands)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2008-01-01

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

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

    Science.gov (United States)

    Jensen, Robert

    2006-01-01

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

  1. Broad CTL response is required to clear latent HIV-1 due to dominance of escape mutations

    Science.gov (United States)

    Deng, Kai; Pertea, Mihaela; Rongvaux, Anthony; Wang, Leyao; Durand, Christine M.; Ghiaur, Gabriel; Lai, Jun; McHugh, Holly L.; Hao, Haiping; Zhang, Hao; Margolick, Joseph B.; Gurer, Cagan; Murphy, Andrew J.; Valenzuela, David M.; Yancopoulos, George D.; Deeks, Steven G.; Strowig, Till; Kumar, Priti; Siliciano, Janet D.; Salzberg, Steven L.; Flavell, Richard A.; Shan, Liang; Siliciano, Robert F.

    2015-01-01

    Despite antiretroviral therapy (ART), HIV-1 persists in a stable latent reservoir1, 2, primarily in resting memory CD4+ T cells3, 4. This reservoir presents a major barrier to the cure of HIV-1 infection. To purge the reservoir, pharmacological reactivation of latent HIV-1 has been proposed5 and tested both in vitro and in vivo6–8. A key remaining question is whether virus-specific immune mechanisms including cytolytic T lymphocytes (CTL) can clear infected cells in ART-treated patients after latency is reversed. Here we show that there is a striking all or none pattern for CTL escape mutations in HIV-1 Gag epitopes. Unless ART is started early, the vast majority (>98%) of latent viruses carry CTL escape mutations that render infected cells insensitive to CTLs directed at common epitopes. To solve this problem, we identified CTLs that could recognize epitopes from latent HIV-1 that were unmutated in every chronically infected patient tested. Upon stimulation, these CTLs eliminated target cells infected with autologous virus derived from the latent reservoir, both in vitro and in patient-derived humanized mice. The predominance of CTL-resistant viruses in the latent reservoir poses a major challenge to viral eradication. Our results demonstrate that chronically infected patients retain a broad spectrum viral-specific CTL response and that appropriate boosting of this response may be required for the elimination of the latent reservoir. PMID:25561180

  2. Homeostatic proliferation fails to efficiently reactivate HIV-1 latently infected central memory CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Alberto Bosque

    2011-10-01

    Full Text Available Homeostatic proliferation ensures the longevity of central memory T-cells by inducing cell proliferation in the absence of cellular differentiation or activation. This process is governed mainly by IL-7. Central memory T-cells can also be stimulated via engagement of the T-cell receptor, leading to cell proliferation but also activation and differentiation. Using an in vitro model of HIV-1 latency, we have examined in detail the effects of homeostatic proliferation on latently infected central memory T cells. We have also used antigenic stimulation via anti-CD3/anti-CD28 antibodies and established a comparison with a homeostatic proliferation stimulus, to evaluate potential differences in how either treatment affects the dynamics of latent virus populations. First, we show that homeostatic proliferation, as induced by a combination of IL-2 plus IL-7, leads to partial reactivation of latent HIV-1 but is unable to reduce the size of the reservoir in vitro. Second, latently infected cells are able to homeostatically proliferate in the absence of viral reactivation or cell differentiation. These results indicate that IL-2 plus IL-7 may induce a detrimental effect by favoring the maintenance of the latent HIV-1 reservoir. On the other hand, antigenic stimulation efficiently reactivated latent HIV-1 in cultured central memory cells and led to depletion of the latently infected cells via virus-induced cell death.

  3. National position statement for the management of latent tuberculosis infection.

    Science.gov (United States)

    Stock, David

    2017-09-01

    The primary role of any tuberculosis (TB) control program is to ensure the prompt identification and effective treatment of active disease. The host immune system often succeeds in containing the initial (or primary) infection with Mycobacterium tuberculosis (Mtb), but may fail to eliminate the pathogen. The persistence of viable organisms explains the potential for the development of active disease years or even decades after infection. This is known as latent tuberculosis infection (LTBI) although, rather than a distinct entity, this probably represents part of a dynamic spectrum. Individuals with LTBI are asymptomatic and it is therefore clinically undetectable. The World Health Organization (WHO) estimates that one-third of the global population has been infected with Mtb, with highest prevalence of LTBI in countries/regions with the highest prevalence of active disease. In 2013, 88% of 1322 notifications in Australia were in the overseas-born population (incidence 19.5 per 100,000 v. 1.0 per 100,000), with this proportion rising over the course of the last decade. Combined with epidemiological evidence of low local transmission, this strongly implies that the vast majority resulted from reactivation of latent infection acquired prior to immigration. Contrasting trends in TB incidence in other developed countries probably reflect differences in policy regarding LTBI. The diagnosis and treatment of LTBI represents an important opportunity for intervention by jurisdictional TB control programs. This work is copyright. You may download, display, print and reproduce the whole or part of this work in unaltered form for your own personal use or, if you are part of an organisation, for internal use within your organisation, but only if you or your organisation do not use the reproduction for any commercial purpose and retain this copyright notice and all disclaimer notices as part of that reproduction. Apart from rights to use as permitted by the Copyright Act 1968 or

  4. [sup 31]P-magnetic resonance spectroscopy: Impaired energy metabolism in latent hyperthyroidism. [sup 31]Phosphor-Kernspinspektroskopie: Gestoerter Energiestoffwechsel bei latenter Hyperthyreose

    Energy Technology Data Exchange (ETDEWEB)

    Theissen, P. (Klinik und Poliklinik fuer Nuklearmedizin, Univ. Koeln (Germany)); Kaldewey, S. (Klinik und Poliklinik fuer Nuklearmedizin, Univ. Koeln (Germany)); Moka, D. (Klinik und Poliklinik fuer Nuklearmedizin, Univ. Koeln (Germany)); Bunke, J. (Philips Medizin Systeme, Hamburg (Germany)); Voth, E. (Klinik und Poliklinik fuer Nuklearmedizin, Univ. Koeln (Germany)); Schicha, H. (Klinik und Poliklinik fuer Nuklearmedizin, Univ. Koeln (Germany))

    1993-06-01

    [sup 31]Phosphorous magnetic resonance spectroscopy allows an in vivo examination of energy metabolism. The present study was designed to evaluate whether in patients with latent hyperthyroidism alterations of muscle energy metabolism could be found similar to those observed in patients with overt hyperthyroidism. In 10 patients with overt hyperthyroidism before therapy and 20 with latent hyperthyroidism (also without therapy) and in 24 healthy volunteers magnetic resonance spectroscopy of the calf muscle was performed within a 1.5-Tesla magnet. Muscle concentrations of phosphocreatine, inorganic phosphate, and ATP were quantified compared to an external standard solution of K[sub 2]HPO[sub 4]. In the patients with overt hyperthyroidism and with latent hyperthyroidism a significant decrease of phosphocreatine was found. Further, the ATP concentration in patients with latent and manifest hyperthyroidism tended towards lower values. There were no significant differences in the decrease of phosphocreatine and ATP between both patient groups. Therefore, this study for the first time shows that alterations of energy metabolism in latent hyperthyroidism can be measured and that they are similar to those observed in overt hyperthyroidism. (orig.)

  5. Merchandising. Alternativa estratégica del marketing en el punto de venta

    OpenAIRE

    Cruz, Darwin

    2007-01-01

    Conociendo que entre las funciones de Merchandising, están las técnicas de colocación se productos, las mismas que han alcanzado madurez a partir del desarrollo de las ventas por el sistema auto-selección, donde las compras que realiza el cliente no necesitasen de la presencia del vendedor.Es necesario, hoy en día, que las empresas cubran de la mejor manera todas las necesidades o deseos latentes que puede tener el cliente. Por esta razón, todo lo que trata el Merchandising, tiene que esta...

  6. The application of seasonal latent variable in forecasting electricity demand as an alternative method

    International Nuclear Information System (INIS)

    Sumer, Kutluk Kagan; Goktas, Ozlem; Hepsag, Aycan

    2009-01-01

    In this study, we used ARIMA, seasonal ARIMA (SARIMA) and alternatively the regression model with seasonal latent variable in forecasting electricity demand by using data that belongs to 'Kayseri and Vicinity Electricity Joint-Stock Company' over the 1997:1-2005:12 periods. This study tries to examine the advantages of forecasting with ARIMA, SARIMA methods and with the model has seasonal latent variable to each other. The results support that ARIMA and SARIMA models are unsuccessful in forecasting electricity demand. The regression model with seasonal latent variable used in this study gives more successful results than ARIMA and SARIMA models because also this model can consider seasonal fluctuations and structural breaks

  7. Development of molecular tests for the detection of ILAR and latent viruses in fruit trees.

    Science.gov (United States)

    Roussel, S; Kummert, J; Dutrecq, O; Lepoivre, P; Jijakli, M H

    2004-01-01

    The detection throughout the year of latent and ILAR viruses in fruit tress by classical serological tests appear to be unreliable. We have developed RT-PCR tests for a reliable detection of latent and ILAR viruses in fruit trees. These assays were then simplified to allow the direct use of crude plant extracts instead of total RNA preparations, and the analyses of pooled samples. In this way, such RT-PCR protocols are suitable for a routine diagnosis of latent and ILAR viruses in fruit tree certification.

  8. Probabilistic Latent Semantic Analyses (PLSA in Bibliometric Analysis for Technology Forecasting

    Directory of Open Access Journals (Sweden)

    Wang Zan

    2007-03-01

    Full Text Available Due to the availability of internet-based abstract services and patent databases, bibliometric analysis has become one of key technology forecasting approaches. Recently, latent semantic analysis (LSA has been applied to improve the accuracy in document clustering. In this paper, a new LSA method, probabilistic latent semantic analysis (PLSA which uses probabilistic methods and algebra to search latent space in the corpus is further applied in document clustering. The results show that PLSA is more accurate than LSA and the improved iteration method proposed by authors can simplify the computing process and improve the computing efficiency

  9. ESTRUCTURA PRIMARIA DE LA CADENA Z EN EL MONO DEL NUEVO MUNDO AOTUS NANCYMAAE

    Directory of Open Access Journals (Sweden)

    HERNANDO DEL CASTILLO

    2008-12-01

    Full Text Available La cadena z es una proteína transmembranal que se encuentra en los linfocitos T, uno de los tipos de células más importantes en el sistema inmune adaptativo, haciendo parte de un complejo multimérico que se ubica en la superficie de la célula y que se encarga, por un lado, del reconocimiento antigénico y por otro, de la transmisión de señales durante la activación de la misma. Esta proteína es una de las que primero se fosforila luego de la estimulación a través del receptor y se sabe que es esencial en los primeros eventos de señalización. Dobles mutantes de esta molécula muestran una respuesta adaptativa inadecuada; así mismo, se ha visto que su expresión está alterada en cáncer y en algunas enfermedades auto-inmunes. La fosforilación en residuos de tirosina que se encuentran en los motivos de activación de residuos de tirosina de los receptores inmunes (ITAMs, de los cuales hay tres en la región citoplasmática, ha demostrado ser uno de los eventos principales durante la activación. En este reporte se presenta la caracterización de la estructura primaria de la cadena z en los monos del nuevo mundo Aotus nancymaae; la secuencia de aminoácidos se dedujo a partir de la secuencia nucleotídica de su cADN. Las moléculas de Aotus presentaron una identidad del 95.5 y del 95.7% con la molécula de humano en las secuencias de nucleótidos y de aminoácidos, respectivamente. Una comparación de la proteína por regiones, mostró una identidad del 100% en la región extracelular y la conservación de residuos y regiones importantes en el resto de la molécula; esto incluye aminoácidos polares en la región transmembranal y los ITAMs en la región citoplasmática. Los resultados sugieren que la proteína de Aotus es plenamente funcional y que los procesos de activación de los linfocitos T se suceden de manera similar a lo descrito en humanos. El resultado mostrado aquí soporta las evidencias previas en el sentido de que las

  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. 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.

  12. Labour market participants’ competitiveness assessment based on latent variables theory

    Directory of Open Access Journals (Sweden)

    T. V. Sabetova

    2017-01-01

    Full Text Available The article suggests innovative model for assessment of labour market subjects’ competitiveness, or successfulness. The authors state that general complex indicator for individual competitiveness within the labour market cannot be identified. Instead, precise enough assessment of such competitiveness can be based on some variables, though different for in-house and external labour market. The model of latent variables’ assessment based on Rasch’s method was selected as the base for the suggested method. The assessment model gives unbiased generalized values of subjects’ competitiveness on the linear non-dimensional scale based on the partial estimates of the selected criteria. The free choice of these criteria allows the model’s appliance for various labour market segments. The article demonstrates the mathematical grounding for the model; methodic of the assessment criteria selection; the way of assessment performance using MS Excel. It also analyses the features of the obtained estimates and shows their comparison with the estimates obtained by traditional methods. The model suggested by the authors can introduce any quantitative parameter of competitiveness as a variable after analysis of the factors affecting it. The quantitative estimates of these factors become the model’s criteria, but the assessment precision does not alter.

  13. 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. (c) 2014 APA, all rights reserved.

  14. The Stability of Social Desirability: A Latent Change Analysis.

    Science.gov (United States)

    Haberecht, Katja; Schnuerer, Inga; Gaertner, Beate; John, Ulrich; Freyer-Adam, Jennis

    2015-08-01

    Social desirability has been shown to be stable in samples with higher school education. However, little is known about the stability of social desirability in more heterogeneous samples differing in school education. This study aimed to investigate the stability of social desirability and which factors predict interindividual differences in intraindividual change. As part of a randomized controlled trial, 1,243 job seekers with unhealthy alcohol use were systematically recruited at three job agencies. A total of 1,094 individuals (87.8%) participated in at least one of two follow-ups (6 and 15 months after baseline) and constitute this study's sample. The Social Desirability Scale-17 was applied. Two latent change models were conducted: Model 1 tested for interindividual differences in intraindividual change of social desirability between both follow-ups; Model 2 included possible predictors (age, sex, education, current employment status) of interindividual differences in intraindividual change. Model 1 revealed a significant decrease of social desirability over time. Model 2 revealed school education to be the only significant predictor of change. These findings indicate that stability of social desirability may depend on school education. It may not be as stable in individuals with higher school education as in individuals with lower education. © 2014 Wiley Periodicals, Inc.

  15. 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.

  16. Latent Factors Limiting the Performance of sEMG-Interfaces

    Directory of Open Access Journals (Sweden)

    Sergey Lobov

    2018-04-01

    Full Text Available Recent advances in recording and real-time analysis of surface electromyographic signals (sEMG have fostered the use of sEMG human–machine interfaces for controlling personal computers, prostheses of upper limbs, and exoskeletons among others. Despite a relatively high mean performance, sEMG-interfaces still exhibit strong variance in the fidelity of gesture recognition among different users. Here, we systematically study the latent factors determining the performance of sEMG-interfaces in synthetic tests and in an arcade game. We show that the degree of muscle cooperation and the amount of the body fatty tissue are the decisive factors in synthetic tests. Our data suggest that these factors can only be adjusted by long-term training, which promotes fine-tuning of low-level neural circuits driving the muscles. Short-term training has no effect on synthetic tests, but significantly increases the game scoring. This implies that it works at a higher decision-making level, not relevant for synthetic gestures. We propose a procedure that enables quantification of the gestures’ fidelity in a dynamic gaming environment. For each individual subject, the approach allows identifying “problematic” gestures that decrease gaming performance. This information can be used for optimizing the training strategy and for adapting the signal processing algorithms to individual users, which could be a way for a qualitative leap in the development of future sEMG-interfaces.

  17. Exploratory Research on Latent Esophageal Motility Disorders in Dysphagia Patients.

    Science.gov (United States)

    Kawaguchi, Shinpei; Takeuchi, Toshihisa; Inoue, Yousuke; Takahashi, Yoshiaki; Ozaki, Haruhiko; Ota, Kazuhiro; Harada, Satoshi; Edogawa, Shoko; Kojima, Yuichi; Yamashita, Hiroshi; Fukuchi, Takumi; Ashida, Kiyoshi; Higuchi, Kazuhide

    2017-01-01

    High-resolution manometry (HRM) has been applied to assess esophageal motility disorders. However, the frequency and types of motility disorders in patients with dysphagia, which are frequently seen in clinical practice, are not clear. We evaluated latent esophageal motility disorders associated with dysphagia. The study included patients without erosive esophageal mucosal damage and with dysphagia symptoms refractory to at least 8 weeks of standard-dose proton pump inhibitors. After enrolment, HRM was used to evaluate for esophageal motility disorder based on the Chicago classification. Esophageal motility disorder was found in 58 of 100 patients and was classified based on the causes: achalasia (13%), esophagogastric junction outflow obstruction (16%), distal esophageal spasms (3%), weak peristalsis (14%), frequently failed peristalsis (5%), and hypertensive peristalsis (7%). Primary esophageal motility disorder was found in approximately 50% of cases in dysphagia patients. Therefore, esophageal motility disorder is not an uncommon condition and should be sought for in order to elucidate precisely the cause of dysphagia. © 2017 S. Karger AG, Basel.

  18. Reward devaluation disrupts latent inhibition in fear conditioning.

    Science.gov (United States)

    De la Casa, Luís Gonzalo; Mena, Auxiliadora; Ruiz-Salas, Juán Carlos; Quintero, Esperanza; Papini, Mauricio R

    2018-03-01

    Three experiments explored the link between reward shifts and latent inhibition (LI). Using consummatory procedures, rewards were either downshifted from 32% to 4% sucrose (Experiments 1-2), or upshifted from 4% to 32% sucrose (Experiment 3). In both cases, appropriate unshifted controls were also included. LI was implemented in terms of fear conditioning involving a single tone-shock pairing after extensive tone-only preexposure. Nonpreexposed controls were also included. Experiment 1 demonstrated a typical LI effect (i.e., disruption of fear conditioning after preexposure to the tone) in animals previously exposed only to 4% sucrose. However, the LI effect was eliminated by preexposure to a 32%-to-4% sucrose devaluation. Experiment 2 replicated this effect when the LI protocol was administered immediately after the reward devaluation event. However, LI was restored when preexposure was administered after a 60-min retention interval. Finally, Experiment 3 showed that a reward upshift did not affect LI. These results point to a significant role of negative emotion related to reward devaluation in the enhancement of stimulus processing despite extensive nonreinforced preexposure experience.

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

    Science.gov (United States)

    Chen, Shuo; Xing, Yishi; Kang, Jian

    2017-01-01

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

  20. On the Latent Variable Interpretation in Sum-Product Networks.

    Science.gov (United States)

    Peharz, Robert; Gens, Robert; Pernkopf, Franz; Domingos, Pedro

    2017-10-01

    One of the central themes in Sum-Product networks (SPNs) is the interpretation of sum nodes as marginalized latent variables (LVs). This interpretation yields an increased syntactic or semantic structure, allows the application of the EM algorithm and to efficiently perform MPE inference. In literature, the LV interpretation was justified by explicitly introducing the indicator variables corresponding to the LVs' states. However, as pointed out in this paper, this approach is in conflict with the completeness condition in SPNs and does not fully specify the probabilistic model. We propose a remedy for this problem by modifying the original approach for introducing the LVs, which we call SPN augmentation. We discuss conditional independencies in augmented SPNs, formally establish the probabilistic interpretation of the sum-weights and give an interpretation of augmented SPNs as Bayesian networks. Based on these results, we find a sound derivation of the EM algorithm for SPNs. Furthermore, the Viterbi-style algorithm for MPE proposed in literature was never proven to be correct. We show that this is indeed a correct algorithm, when applied to selective SPNs, and in particular when applied to augmented SPNs. Our theoretical results are confirmed in experiments on synthetic data and 103 real-world datasets.

  1. Latent Clustering Models for Outlier Identification in Telecom Data

    Directory of Open Access Journals (Sweden)

    Ye Ouyang

    2016-01-01

    Full Text Available Collected telecom data traffic has boomed in recent years, due to the development of 4G mobile devices and other similar high-speed machines. The ability to quickly identify unexpected traffic data in this stream is critical for mobile carriers, as it can be caused by either fraudulent intrusion or technical problems. Clustering models can help to identify issues by showing patterns in network data, which can quickly catch anomalies and highlight previously unseen outliers. In this article, we develop and compare clustering models for telecom data, focusing on those that include time-stamp information management. Two main models are introduced, solved in detail, and analyzed: Gaussian Probabilistic Latent Semantic Analysis (GPLSA and time-dependent Gaussian Mixture Models (time-GMM. These models are then compared with other different clustering models, such as Gaussian model and GMM (which do not contain time-stamp information. We perform computation on both sample and telecom traffic data to show that the efficiency and robustness of GPLSA make it the superior method to detect outliers and provide results automatically with low tuning parameters or expertise requirement.

  2. Preparation of fine powdered composite for latent heat storage

    Energy Technology Data Exchange (ETDEWEB)

    Fořt, Jan, E-mail: jan.fort.1@fsv.cvut.cz; Trník, Anton, E-mail: anton.trnik@fsv.cvut.cz; Pavlíková, Milena, E-mail: milena.pavlikova@fsv.cvut.cz; Pavlík, Zbyšek, E-mail: pavlikz@fsv.cvut.cz [Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic); Pomaleski, Marina, E-mail: marina-pomaleski@fsv.cvut.cz [Faculty of Civil Engineering, Architecture and Urbanism, University of Campinas, R. Saturnino de Brito 224, 13083-889 Campinas – SP (Brazil)

    2016-07-07

    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.

  3. Is there any role of latent toxoplasmosis in schizophrenia disease?

    Science.gov (United States)

    Karabulut, Nuran; Bilgiç, Serkan; Gürok, Mehmet Gürkan; Karaboğa, Fatih

    2015-09-01

    A large number of studies have hypothesized that Toxoplasma gondii is a potentially relevant etiological factor in some cases of schizophrenia. By contrast, some studies have disproved this association. The aim of this study was to investigate whether latent toxoplasmosis has any role in schizophrenia disease. Additionally, the association between T. gondii and subtypes of schizophrenia, and the impacts of toxoplasmosis on psychopathology were examined in the study. A total of 85 patients with schizophrenia and 60 healthy volunteers were included in this prospective study. Immunoglobulin G (IgG) antibody to T. gondii was examined by enzyme-linked immune-sorbent assay method. Seropositivity rates were 43.5% for the patients with schizophrenia and 43.3% for the healthy controls (odds ratio: 1.008, 95% confidence interval: 0.517-1.964, p = 0.981).There was no significant difference in T. gondii IgG positivity between the schizophrenia and control groups with respect to sex and age. The difference in seroprevalence of T. gondii IgG antibodies among the schizophrenia subtypes was not statistically significant (p = 0.934). No significant difference was found in Positive and Negative Syndrome Subscales between Toxoplasma-infected and Toxoplasma-free patients. In the study area with a high prevalence of T. gondii, no association between toxoplasmosis and schizophrenia was detected. These findings showed that toxoplasmosis has no role in the risk of schizophrenia disease. Copyright © 2015. Published by Elsevier Taiwan.

  4. Parent involvement and science achievement: A latent growth curve analysis

    Science.gov (United States)

    Johnson, Ursula Yvette

    This study examined science achievement growth across elementary and middle school and parent school involvement using the Early Childhood Longitudinal Study - Kindergarten Class of 1998--1999 (ECLS-K). The ECLS-K is a nationally representative kindergarten cohort of students from public and private schools who attended full-day or half-day kindergarten class in 1998--1999. The present study's sample (N = 8,070) was based on students that had a sampling weight available from the public-use data file. Students were assessed in science achievement at third, fifth, and eighth grades and parents of the students were surveyed at the same time points. Analyses using latent growth curve modeling with time invariant and varying covariates in an SEM framework revealed a positive relationship between science achievement and parent involvement at eighth grade. Furthermore, there were gender and racial/ethnic differences in parents' school involvement as a predictor of science achievement. Findings indicated that students with lower initial science achievement scores had a faster rate of growth across time. The achievement gap between low and high achievers in earth, space and life sciences lessened from elementary to middle school. Parents' involvement with school usually tapers off after elementary school, but due to parent school involvement being a significant predictor of eighth grade science achievement, later school involvement may need to be supported and better implemented in secondary schooling.

  5. Latent Factor Structure of DSM-5 Posttraumatic Stress Disorder

    Science.gov (United States)

    Gentes, Emily; Dennis, Paul A.; Kimbrel, Nathan A.; Kirby, Angela C.; Hair, Lauren P.; Beckham, Jean C.; Calhoun, Patrick S.

    2015-01-01

    The current study examined the latent factor structure of posttraumatic stress disorder (PTSD) based on DSM-5 criteria in a sample of participants (N = 374) recruited for studies on trauma and health. Confirmatory factor analyses (CFA) were used to compare the fit of the previous 3-factor DSM-IV model of PTSD to the 4-factor model specified in DSM-5 as well as to a competing 4-factor “dysphoria” model (Simms, Watson, & Doebbeling, 2002) and a 5-factor (Elhai et al., 2011) model of PTSD. Results indicated that the Elhai 5-factor model (re-experiencing, active avoidance, emotional numbing, dysphoric arousal, anxious arousal) provided the best fit to the data, although substantial support was demonstrated for the DSM-5 4-factor model. Low factor loadings were noted for two of the symptoms in the DSM-5 model (psychogenic amnesia and reckless/self-destructive behavior), which raises questions regarding the adequacy of fit of these symptoms with other core features of the disorder. Overall, the findings from the present research suggest the DSM-5 model of PTSD is a significant improvement over the previous DSM-IV model of PTSD. PMID:26366290

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

    Science.gov (United States)

    Hebbern, Christopher A; Laursen, Kristian Holst; Ladegaard, Anne H; Schmidt, Sidsel B; Pedas, Pai; Bruhn, Dan; Schjoerring, Jan K; Wulfsohn, Dvoralai; Husted, Søren

    2009-03-01

    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 revealed that the quantum yield efficiency of PSII (F(v)/F(m)) was reduced from 0.83 in Mn-sufficient control plants to below 0.5 in Mn-starved plants. Leaf Mn concentrations declined from 30 to 7 microg Mn g(-1) dry weight in control and Mn-starved plants, respectively. Mn-starved plants had up to four-fold higher transpiration than control plants. Stomatal closure and opening upon light/dark transitions took place at the same rate in both Mn treatments, but the nocturnal leaf conductance for water vapour was still twice as high in Mn-starved plants compared with the control. The observed increase in transpiration was substantiated by (13)C-isotope discrimination analysis and gravimetric measurement of the water consumption, showing significantly lower water use efficiency in Mn-starved plants. The extractable wax content of leaves of Mn-starved plants was approximately 40% lower than that in control plants, and it is concluded that the increased leaf conductance and higher transpirational water loss are correlated with a reduction in the epicuticular wax layer under Mn deficiency.

  7. A latent low-dimensional common input drives a pool of motor neurons: a probabilistic latent state-space model.

    Science.gov (United States)

    Feeney, Daniel F; Meyer, François G; Noone, Nicholas; Enoka, Roger M

    2017-10-01

    Motor neurons appear to be activated with a common input signal that modulates the discharge activity of all neurons in the motor nucleus. It has proven difficult for neurophysiologists to quantify the variability in a common input signal, but characterization of such a signal may improve our understanding of how the activation signal varies across motor tasks. Contemporary methods of quantifying the common input to motor neurons rely on compiling discrete action potentials into continuous time series, assuming the motor pool acts as a linear filter, and requiring signals to be of sufficient duration for frequency analysis. We introduce a space-state model in which the discharge activity of motor neurons is modeled as inhomogeneous Poisson processes and propose a method to quantify an abstract latent trajectory that represents the common input received by motor neurons. The approach also approximates the variation in synaptic noise in the common input signal. The model is validated with four data sets: a simulation of 120 motor units, a pair of integrate-and-fire neurons with a Renshaw cell providing inhibitory feedback, the discharge activity of 10 integrate-and-fire neurons, and the discharge times of concurrently active motor units during an isometric voluntary contraction. The simulations revealed that a latent state-space model is able to quantify the trajectory and variability of the common input signal across all four conditions. When compared with the cumulative spike train method of characterizing common input, the state-space approach was more sensitive to the details of the common input current and was less influenced by the duration of the signal. The state-space approach appears to be capable of detecting rather modest changes in common input signals across conditions. NEW & NOTEWORTHY We propose a state-space model that explicitly delineates a common input signal sent to motor neurons and the physiological noise inherent in synaptic signal

  8. Acerca del moho

    Science.gov (United States)

    El moho forma parte del medio ambiente natural. Afuera del hogar, el moho juega un papel en la naturaleza al desintegrar materias organicas tales como las hojas que se han caido o los arboles muertos. El moho puede crecer adentro del hogar cuando las espor

  9. Del bit al qubit

    OpenAIRE

    Torras Font, Josep

    2011-01-01

    Aquest document pretén donar una visió del desenvolupament dels computadors electrònics i dels components que els han fet possibles. Dintre de les opcions de futur en computació, també intenta donar una visió de les bases en que es fonamenta la computació quàntica.

  10. Fatal and serious road crashes involving young New Zealand drivers: a latent class clustering approach

    DEFF Research Database (Denmark)

    Weiss, Harold B.; Kaplan, Sigal; Prato, Carlo Giacomo

    2016-01-01

    , infrastructure characteristics, environmental conditions, demographic characteristics, driving behaviour, and pre-crash manoeuvres. The analysis yielded 15 and 8 latent classes of, respectively, single-vehicle and multi-vehicle crashes, and average posterior probabilities measured the odds of correct...

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

    Science.gov (United States)

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

    2012-01-01

    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 prevalent than ADHD in youth (which could suggest a more severe adult ADHD taxon), researchers have yet to examine the latent structure of ADHD in adults. The present study used a sample (N = 600) of adults who completed a self-report measure of ADHD symptoms. The taxometric analyses revealed a dimensional latent structure for inattention, hyperactivity/impulsivity, and ADHD. These findings are consistent with previous taxometric studies that examined ADHD in children and adolescents, and with contemporary polygenic and multifactorial models of ADHD. PMID:22480749

  12. Latent M. tuberculosis infection--pathogenesis, diagnosis, treatment and prevention strategies.

    Science.gov (United States)

    Druszczyńska, Magdalena; Kowalewicz-Kulbat, Magdalena; Fol, Marek; Włodarczyk, Marcin; Rudnicka, Wiesława

    2012-01-01

    One third of the earths population is infected with Mycobacterium tuberculosis (Mtb), but only 5-10% of the infected individuals develop active tuberculosis (TB) over their lifetime. The remaining 90-95% stay healthy and are called latently infected individuals. They are the biggest reservoir of the tubercle bacilli and identifying the cases of latent TB is a part of the global plan of TB control. From the clinical point of view detection of latent TB infections (LTBI) in individuals with the highest active TB risk including cases of HIV infection, autoimmune inflammatory diseases or cancer, is a priority. This review summarizes the recent findings in the pathogenesis of latent TB, its diagnosis, treatment and prevention.

  13. The Latent Class Model as a Measurement Model for Situational Judgment Tests

    Directory of Open Access Journals (Sweden)

    Frank Rijmen

    2011-11-01

    Full Text Available In a situational judgment test, it is often debatable what constitutes a correct answer to a situation. There is currently a multitude of scoring procedures. Establishing a measurement model can guide the selection of a scoring rule. It is argued that the latent class model is a good candidate for a measurement model. Two latent class models are applied to the Managing Emotions subtest of the Mayer, Salovey, Caruso Emotional Intelligence Test: a plain-vanilla latent class model, and a second-order latent class model that takes into account the clustering of several possible reactions within each hypothetical scenario of the situational judgment test. The results for both models indicated that there were three subgroups characterised by the degree to which differentiation occurred between possible reactions in terms of perceived effectiveness. Furthermore, the results for the second-order model indicated a moderate cluster effect.

  14. Resveratrol Reactivates Latent HIV through Increasing Histone Acetylation and Activating Heat Shock Factor 1.

    Science.gov (United States)

    Zeng, Xiaoyun; Pan, Xiaoyan; Xu, Xinfeng; Lin, Jian; Que, Fuchang; Tian, Yuanxin; Li, Lin; Liu, Shuwen

    2017-06-07

    The persistence of latent HIV reservoirs presents a significant challenge to viral eradication. Effective latency reversing agents (LRAs) based on "shock and kill" strategy are urgently needed. The natural phytoalexin resveratrol has been demonstrated to enhance HIV gene expression, although its mechanism remains unclear. In this study, we demonstrated that resveratrol was able to reactivate latent HIV without global T cell activation in vitro. Mode of action studies showed resveratrol-mediated reactivation from latency did not involve the activation of silent mating type information regulation 2 homologue 1 (SIRT1), which belonged to class-3 histone deacetylase (HDAC). However, latent HIV was reactivated by resveratrol mediated through increasing histone acetylation and activation of heat shock factor 1 (HSF1). Additionally, synergistic activation of the latent HIV reservoirs was observed under cotreatment with resveratrol and conventional LRAs. Collectively, this research reveals that resveratrol is a natural LRA and shows promise for HIV therapy.

  15. 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

  16. Alexithymia and psychosocial problems among Italian preadolescents. A latent class analysis approach.

    Science.gov (United States)

    Mannarini, Stefania; Balottin, Laura; Toldo, Irene; Gatta, Michela

    2016-10-01

    The study, conducted on Italian preadolscents aged 11 to 13 belonging to the general population, aims to investigate the relationship between the emotional functioning, namely, alexithymia, and the risk of developing behavioral and emotional problems measured using the Strength and Difficulty Questionnaire. The latent class analysis approach allowed to identify two latent variables, accounting for the internalizing (emotional symptoms and difficulties in emotional awareness) and for the externalizing problems (conduct problems and hyperactivity, problematic relationships with peers, poor prosocial behaviors and externally oriented thinking). The two latent variables featured two latent classes: the difficulty in dealing with problems and the strength to face problems that was representative of most of the healthy participants with specific gender differences. Along with the analysis of psychopathological behaviors, the study of resilience and strengths can prove to be a key step in order to develop valuable preventive approaches to tackle psychiatric disorders. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  17. Managerial performance and cost efficiency of Japanese local public hospitals: a latent class stochastic frontier model.

    Science.gov (United States)

    Besstremyannaya, Galina

    2011-09-01

    The paper explores the link between managerial performance and cost efficiency of 617 Japanese general local public hospitals in 1999-2007. Treating managerial performance as unobservable heterogeneity, the paper employs a panel data stochastic cost frontier model with latent classes. Financial parameters associated with better managerial performance are found to be positively significant in explaining the probability of belonging to the more efficient latent class. The analysis of latent class membership was consistent with the conjecture that unobservable technological heterogeneity reflected in the existence of the latent classes is related to managerial performance. The findings may support the cause for raising efficiency of Japanese local public hospitals by enhancing the quality of management. Copyright © 2011 John Wiley & Sons, Ltd.

  18. Cross-covariance functions for multivariate random fields based on latent dimensions

    KAUST Repository

    Apanasovich, T. V.; Genton, M. G.

    2010-01-01

    The problem of constructing valid parametric cross-covariance functions is challenging. We propose a simple methodology, based on latent dimensions and existing covariance models for univariate random fields, to develop flexible, interpretable

  19. 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.

  20. New developing reagent for latent fingermark visualization: Fuller’s earth (Multani Mitti

    Directory of Open Access Journals (Sweden)

    Pallavi Thakur

    2016-12-01

    Full Text Available A number of methods have been reported in the literature for the development of latent fingermarks on different surfaces. This paper reports a new and simple powdering method which is non-toxic and has been employed on different substrates successfully for the development and visualization of latent fingermarks up to the time period of 6 days in varying temperature conditions. In this investigation a less expensive, simple and easily available fuller’s earth (Multani Mitti powder has been used to decipher the latent fingermarks on different substrates namely black cardboard box, clear glass, coverslip box, steel surface, laminated wooden sheet, clear plastic, colored plastic bag and surface of highlighter pen. It is observed that it gives very clear results on majority of substrates and can be successfully used for the development and visualization of latent fingermarks.

  1. 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.

  2. Latent Tuberculosis Infection in an Urban Cohort: Screening and Treatment for Latent TB in an Urban Setting

    Science.gov (United States)

    Morano, Jamie P.; Walton, Mary R.; Zelenev, Alexei; Bruce, R. Douglas; Altice, Frederick L.

    2013-01-01

    Background Despite its benefit for treating active tuberculosis, directly observed therapy (DOT) for latent tuberculosis infection (LTBI) has been largely understudied among challenging inner city populations. Methods Utilizing questionnaire data from a comprehensive mobile healthcare clinic in New Haven, CT from 2003 to July 2011, a total of 2523 completed tuberculin skin tests (TST’s) resulted in 357 new LTBIs. Multivariate logistic regression correlated covariates of the two outcomes 1) initiation of isoniazid preventative therapy (IPT) and 2) completion of 9-months IPT. Results Of 357 new LTBIs, 86.3% (n=308) completed screening CXRs: 90.3% (n=278) were normal and 0.3% (n=1) with active tuberculosis. Of those completing CXR screening, 44.0% (n=135) agreed to IPT: 69.6% (n=94) selected DOT, and 30.4% (n=41) selected SAT. Initiating IPT was correlated with undocumented status (AOR=3.43; pmodels for LTBI treatment resulted in similar outcomes, yet outcomes were hampered by differential measurement bias between DOT and SAT participants. PMID:23728822

  3. Some children with autism have latent social skills that can be tested

    Czech Academy of Sciences Publication Activity Database

    Hrdlička, M.; Urbánek, Tomáš; Vacová, M.; Beranová, Š.; Dudová, I.

    2017-01-01

    Roč. 13, March (2017), s. 827-833 ISSN 1178-2021 Institutional support: RVO:68081740 Keywords : autism * latent social skills * Autism Diagnostic Interview – Revised * Autism Diagnostic Observation Schedule * prediction Subject RIV: AN - Psychology OBOR OECD: Psychology (including human - machine relations) Impact factor: 2.198, year: 2016 https://www.dovepress.com/some-children-with- autism -have-latent-social-skills-that-can-be-tested-peer-reviewed-article-NDT

  4. Substantiation for Approaches to Treatment of Latent Autoimmune Diabetes in Adults

    Directory of Open Access Journals (Sweden)

    T.M. Tykhonova

    2014-10-01

    Conclusions. Analysis of carbohydrate metabolism on the manifestation stage and over time development of latent autoimmune diabetes in adults as well as reduction of β-cells insulin-producing function associated with autoimmune insulitis and progressing while the development of this form of disease, substantiate the rational for insulin administration as this form of diabetes has been diagnosed. If patients with latent autoimmune diabetes in adults have metabolic syndrome clusters it is quite reasonable to add metformin to insulin.

  5. Some children with autism have latent social skills that can be tested

    Czech Academy of Sciences Publication Activity Database

    Hrdlička, M.; Urbánek, Tomáš; Vacová, M.; Beranová, Š.; Dudová, I.

    2017-01-01

    Roč. 13, March (2017), s. 827-833 ISSN 1178-2021 Institutional support: RVO:68081740 Keywords : autism * latent social skills * Autism Diagnostic Interview – Revised * Autism Diagnostic Observation Schedule * prediction Subject RIV: AN - Psychology OBOR OECD: Psychology (including human - machine relations) Impact factor: 2.198, year: 2016 https://www.dovepress.com/some-children-with-autism-have-latent- social -skills-that-can-be-tested-peer-reviewed-article-NDT

  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. Dorsal bundle lesions do not affect latent inhibition of conditioned suppression.

    Science.gov (United States)

    Tsaltas, E; Preston, G C; Rawlins, J N; Winocur, G; Gray, J A

    1984-01-01

    Three experiments are reported which examine the effects of lesions of the dorsal ascending noradrenergic bundle (DB) on latent inhibition using a conditioned suppression procedure in rats. In none of the experiments did the DB lesion have any effect, despite changes in the extent of latent inhibition and in the control procedures used to assess it. The results are discussed in relation to the attentional theory of DB function.

  8. Assessing Factors Related to Waist Circumference and Obesity: Application of a Latent Variable Model

    OpenAIRE

    Dalvand, Sahar; Koohpayehzadeh, Jalil; Karimlou, Masoud; Asgari, Fereshteh; Rafei, Ali; Seifi, Behjat; Niksima, Seyed Hassan; Bakhshi, Enayatollah

    2015-01-01

    Background. Because the use of BMI (Body Mass Index) alone as a measure of adiposity has been criticized, in the present study our aim was to fit a latent variable model to simultaneously examine the factors that affect waist circumference (continuous outcome) and obesity (binary outcome) among Iranian adults. Methods. Data included 18,990 Iranian individuals aged 20–65 years that are derived from the third National Survey of Noncommunicable Diseases Risk Factors in Iran. Using latent variabl...

  9. Space-time latent component Modeling of Geo-referenced health data

    OpenAIRE

    Lawson, Andrew B.; Song, Hae-Ryoung; Cai, Bo; Hossain, Md Monir; Huang, Kun

    2010-01-01

    Latent structure models have been proposed in many applications. For space time health data it is often important to be able to find underlying trends in time which are supported by subsets of small areas. Latent structure modeling is one approach to this analysis. This paper presents a mixture-based approach that can be appied to component selction. The analysis of a Georgia ambulatory asthma county level data set is presented and a simulation-based evaluation is made.

  10. Experimental Examination of Bacteriophage Latent-Period Evolution as a Response to Bacterial Availability

    OpenAIRE

    Abedon, Stephen T.; Hyman, Paul; Thomas, Cameron

    2003-01-01

    For obligately lytic bacteriophage (phage) a trade-off exists between fecundity (burst size) and latent period (a component of generation time). This trade-off occurs because release of phage progeny from infected bacteria coincides with destruction of the machinery necessary to produce more phage progeny. Here we employ phage mutants to explore issues of phage latent-period evolution as a function of the density of phage-susceptible bacteria. Theory suggests that higher bacterial densities s...

  11. Tuberculosis and latent tuberculosis infection among healthcare workers in Kisumu, Kenya.

    Science.gov (United States)

    Agaya, Janet; Nnadi, Chimeremma D; Odhiambo, Joseph; Obonyo, Charles; Obiero, Vincent; Lipke, Virginia; Okeyo, Elisha; Cain, Kevin; Oeltmann, John E

    2015-12-01

    To assess prevalence and occupational risk factors of latent TB infection and history of TB disease ascribed to work in a healthcare setting in western Kenya. We conducted a cross-sectional survey among healthcare workers in western Kenya in 2013. They were recruited from dispensaries, health centres and hospitals that offer both TB and HIV services. School workers from the health facilities' catchment communities were randomly selected to serve as the community comparison group. Latent TB infection was diagnosed by tuberculin skin testing. HIV status of participants was assessed. Using a logistic regression model, we determined the adjusted odds of latent TB infection among healthcare workers compared to school workers; and among healthcare workers only, we assessed work-related risk factors for latent TB infection. We enrolled 1005 healthcare workers and 411 school workers. Approximately 60% of both groups were female. A total of 22% of 958 healthcare workers and 12% of 392 school workers tested HIV positive. Prevalence of self-reported history of TB disease was 7.4% among healthcare workers and 3.6% among school workers. Prevalence of latent TB infection was 60% among healthcare workers and 48% among school workers. Adjusted odds of latent TB infection were 1.5 times higher among healthcare workers than school workers (95% confidence interval 1.2-2.0). Healthcare workers at all three facility types had similar prevalence of latent TB infection (P = 0.72), but increasing years of employment was associated with increased odds of LTBI (P Kenya which offer TB and HIV services are at increased risk of latent TB infection, and the risk is similar across facility types. Implementation of WHO-recommended TB infection control measures are urgently needed in health facilities to protect healthcare workers. © 2015 John Wiley & Sons Ltd.

  12. A model for the latent heat of melting in free standing metal nanoparticles

    International Nuclear Information System (INIS)

    Shin, Jeong-Heon; Deinert, Mark R.

    2014-01-01

    Nanoparticles of many metals are known to exhibit scale dependent latent heats of melting. Analytical models for this phenomenon have so far failed to completely capture the observed phenomena. Here we present a thermodynamic analysis for the melting of metal nanoparticles in terms of their internal energy and a scale dependent surface tension proposed by Tolman. The resulting model predicts the scale dependence of the latent heat of melting and is confirmed using published data for tin and aluminum

  13. Clonal deleted latent membrane protein 1 variants of Epstein-Barr virus are predominant in European extranodal NK/T lymphomas and disappear during successful treatment.

    Science.gov (United States)

    Halabi, Mohamad Adnan; Jaccard, Arnaud; Moulinas, Rémi; Bahri, Racha; Al Mouhammad, Hazar; Mammari, Nour; Feuillard, Jean; Ranger-Rogez, Sylvie

    2016-08-15

    Extranodal natural killer/T-cell lymphomas (NK/TL), rare in Europe, are Epstein-Barr virus (EBV) associated lymphomas with poor outcomes. Here, we determined the virus type and analyzed the EBV latent membrane protein-1 (LMP1) gene sequence in NK/TL from French patients. Six clones of viral LMP1 were sequenced by Sanger technology in blood from 13 patients before treatment with an l-asparaginase based regimen and, for 8 of them, throughout the treatment. Blood LMP1 sequences from 21 patients without any known malignancy were tested as controls. EBV Type A was identified for 11/13 patients and for all controls. Before treatment, a clonal LMP1 gene containing a 30 bp deletion (del30) was found in 46.1% of NK/TL and only in 4.8% of controls. Treatment was less effective in these patients who died more rapidly than the others. Patients with a deleted strain evolving toward a wild-type strain during treatment reached complete remission. The LMP1 gene was sequenced by highly sensitive next-generation sequencing technology in five NK/TL nasopharyngeal biopsies, two of them originating from the previous patients. Del30 was present in 100% of the biopsies; two viruses at least coexisted in three biopsies. These results suggest that del30 may be associated with poor prognosis NK/TL and that strain evolution could be used as a potential marker to monitor treatment. © 2016 UICC.

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

    International Nuclear Information System (INIS)

    Davis, H.T.

    1978-01-01

    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

  15. 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.

  16. Prevalence of latent Mycobacterium tuberculosis infection among professionals of the primary healthcare network

    Directory of Open Access Journals (Sweden)

    Tássia Silvana Borges

    2014-06-01

    Full Text Available Objective: To estimate the prevalence of latent M. tuberculosis infection and identify characteristics related to latent infection among workers of the primary healthcare network.Methods: Cross-sectional, observational and descriptive study, conducted in 2011, included 137 basic health workers who performed their activities in a municipality. Interviews were carried out addressing characteristics of exposure at work (BCG vaccination, length of time working in the health system, potential exposure to tuberculosis, HIV infection, use of corticosteroids, diabetes, use of tobacco or alcohol and subsequently performed tuberculin skin test (TST. Data was analyzed with Fischer and Student’s t-test (p < 0.05. Results: Health professionals were mostly women (n=126, 92% with mean age of 35.3 (± 9.1 years. Among the reactors, 25 (55.5% sought medical care, and of these, 7 (28% underwent prophylactic treatment. The prevalence of latent tuberculosis was 32.8%. Of the characteristics evaluated, only smoking (OR 3.03; 95%CI 1.05-8.77 was associated with latent infection. Conclusion: The estimated prevalence of latent M. tuberculosis infection among the evaluated health workers was 32.8%. As for the characteristics studied, it was not possible to relate them to latent infection among workers in primary healthcare network, with the exception of the smoking habit. doi: 10.5020/18061230.2014.p269

  17. A stable latent reservoir for HIV-1 in resting CD4+ T lymphocytes in infected children

    Science.gov (United States)

    Persaud, Deborah; Pierson, Theodore; Ruff, Christian; Finzi, Diana; Chadwick, Karen R.; Margolick, Joseph B.; Ruff, Andrea; Hutton, Nancy; Ray, Stuart; Siliciano, Robert F.

    2000-01-01

    HIV-1 persists in a latent state in resting CD4+ T lymphocytes of infected adults despite prolonged highly active antiretroviral therapy (HAART). To determine whether a latent reservoir for HIV-1 exists in infected children, we performed a quantitative viral culture assay on highly purified resting CD4+ T cells from 21 children with perinatally acquired infection. Replication-competent HIV-1 was recovered from all 18 children from whom sufficient cells were obtained. The frequency of latently infected resting CD4+ T cells directly correlated with plasma virus levels, suggesting that in children with ongoing viral replication, most latently infected cells are in the labile preintegration state of latency. However, in each of 7 children who had suppression of viral replication to undetectable levels for 1–3 years on HAART, latent replication-competent HIV-1 persisted with little decay, owing to a stable reservoir of infected cells in the postintegration stage of latency. Drug-resistance mutations generated by previous nonsuppressive regimens persisted in this compartment despite more than 1 year of fully suppressive HAART, rendering untenable the idea of recycling drugs that were part of failed regimens. Thus the latent reservoir for HIV-1 in resting CD4+ T cells will be a major obstacle to HIV-1 eradication in children. PMID:10749578

  18. Latent memory facilitates relearning through molecular signaling mechanisms that are distinct from original learning.

    Science.gov (United States)

    Menges, Steven A; Riepe, Joshua R; Philips, Gary T

    2015-09-01

    A highly conserved feature of memory is that it can exist in a latent, non-expressed state which is revealed during subsequent learning by its ability to significantly facilitate (savings) or inhibit (latent inhibition) subsequent memory formation. Despite the ubiquitous nature of latent memory, the mechanistic nature of the latent memory trace and its ability to influence subsequent learning remains unclear. The model organism Aplysia californica provides the unique opportunity to make strong links between behavior and underlying cellular and molecular mechanisms. Using Aplysia, we have studied the mechanisms of savings due to latent memory for a prior, forgotten experience. We previously reported savings in the induction of three distinct temporal domains of memory: short-term (10min), intermediate-term (2h) and long-term (24h). Here we report that savings memory formation utilizes molecular signaling pathways that are distinct from original learning: whereas the induction of both original intermediate- and long-term memory in naïve animals requires mitogen activated protein kinase (MAPK) activation and ongoing protein synthesis, 2h savings memory is not disrupted by inhibitors of MAPK or protein synthesis, and 24h savings memory is not dependent on MAPK activation. Collectively, these findings reveal that during forgetting, latent memory for the original experience can facilitate relearning through molecular signaling mechanisms that are distinct from original learning. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Prevalence of latent Mycobacterium tuberculosis infection in prisoners.

    Science.gov (United States)

    Navarro, Pedro Daibert de; Almeida, Isabela Neves de; Kritski, Afrânio Lineu; Ceccato, Maria das Graças; Maciel, Mônica Maria Delgado; Carvalho, Wânia da Silva; Miranda, Silvana Spindola de

    2016-01-01

    To determine the prevalence of and the factors associated with latent Mycobacterium tuberculosis infection (LTBI) in prisoners in the state of Minas Gerais, Brazil. This was a cross-sectional cohort study conducted in two prisons in Minas Gerais. Tuberculin skin tests were performed in the individuals who agreed to participate in the study. A total of 1,120 individuals were selected for inclusion in this study. The prevalence of LTBI was 25.2%. In the multivariate analysis, LTBI was associated with self-reported contact with active tuberculosis patients within prisons (adjusted OR = 1.51; 95% CI: 1.05-2.18) and use of inhaled drugs (adjusted OR = 1.48; 95% CI: 1.03-2.13). Respiratory symptoms were identified in 131 (11.7%) of the participants. Serological testing for HIV was performed in 940 (83.9%) of the participants, and the result was positive in 5 (0.5%). Two cases of active tuberculosis were identified during the study period. Within the prisons under study, the prevalence of LTBI was high. In addition, LTBI was associated with self-reported contact with active tuberculosis patients and with the use of inhaled drugs. Our findings demonstrate that it is necessary to improve the conditions in prisons, as well as to introduce strategies, such as chest X-ray screening, in order to detect tuberculosis cases and, consequently, reduce M. tuberculosis infection within the prison system. Determinar a prevalência e os fatores associados à infecção latente por Mycobacterium tuberculosis (ILTB) em pessoas privadas de liberdade no Estado de Minas Gerais. Estudo de coorte transversal realizado em duas penitenciárias em Minas Gerais. Foi realizada a prova tuberculínica nos indivíduos que aceitaram participar do estudo. Foram selecionados 1.120 indivíduos para a pesquisa. A prevalência da ILTB foi de 25,2%. Na análise multivariada, a ILTB esteve associada com relato de contato com caso de tuberculose ativa dentro da penitenciária (OR ajustada = 1,51; IC95%: 1

  20. 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.

  1. 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.

  2. 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.

  3. Latent tuberculous infection screening using recombinant tuberculous allergen

    Directory of Open Access Journals (Sweden)

    N. A. Barmina

    2016-01-01

    Full Text Available In recent years the significant deterioration of health has been observed in schoolchildren. As per official data only 20% of children graduating from school are considered to be completely healthy, and 60% suffer from chronic diseases, i.e. belong to health groups III, IV and V, among which there are many children belonging to tuberculosis risk groups and suffering from undetected latent tuberculous infection. The efficiency of the new technique aimed to detect active tuberculous infection in children and adolescents of health groups III, IV and V has been evaluated. Screening proved the reduction in the number of patients in need of TB doctor advising by 8.4 fold compared to traditional mass diagnostics with tuberculin. Hyperergic reactions to diaskintest are 6 fold less common compared to Mantoux test. And 99.2% of children referred to TB doctor were registered to the dispensary follow-up versus 23.4% of children referred to TB doctor as per mass tuberculin testing results. (p < 0.001. Thus the validity of referral to TB doctor increased 4.2 fold. The detection rate of active forms of tuberculosis made 0.4 per 1000 examinations versus 0.1 in case of mass screening with tuberculin testing.

  4. Persistent Latent Tuberculosis Reactivation Risk in United States Immigrants

    Science.gov (United States)

    Painter, John; Parker, Matthew; Lowenthal, Phillip; Flood, Jennifer; Fu, Yunxin; Asis, Redentor; Reves, Randall

    2014-01-01

    Rationale: Current guidelines limit latent tuberculosis infection (LTBI) evaluation to persons in the United States less than or equal to 5 years based on the assumption that high TB rates among recent entrants are attributable to high LTBI reactivation risk, which declines over time. We hypothesized that high postarrival TB rates may instead be caused by imported active TB. Objectives: Estimate reactivation and imported TB in an immigrant cohort. Methods: We linked preimmigration records from a cohort of California-bound Filipino immigrants during 2001–2010 with subsequent TB reports. TB was likely LTBI reactivation if the immigrant had no evidence of active TB at preimmigration examination, likely imported if preimmigration radiograph was abnormal and TB was reported less than or equal to 6 months after arrival, and likely reactivation of inactive TB if radiograph was abnormal but TB was reported more than 6 months after arrival. Measurements and Main Results: Among 123,114 immigrants, 793 TB cases were reported. Within 1 year of preimmigration examination, 85% of TB was imported; 6 and 9% were reactivation of LTBI and inactive TB, respectively. Conversely, during Years 2–9 after U.S. entry, 76 and 24% were reactivation of LTBI and inactive TB, respectively. The rate of LTBI reactivation (32 per 100,000) did not decline during Years 1–9. Conclusions: High postarrival TB rates were caused by detection of imported TB through active postarrival surveillance. Among immigrants without active TB at baseline, reported TB did not decline over 9 years, indicating sustained high risk of LTBI reactivation. Revised guidelines should support LTBI screening and treatment more than 5 years after U.S. arrival. PMID:24308495

  5. STATUS SOSIAL EKONOMI DAN FERTILITAS: A Latent Variable Approach

    Directory of Open Access Journals (Sweden)

    Suandi -

    2012-11-01

    Full Text Available The main problems faced by developing countries including Indonesia are not onlyeconomic problems that tend to harm, but still met the high fertility rate. The purpose ofwriting to find out the relationship between socioeconomic status to the level of fertilitythrough the "A Latent Variable Approach." The study adopts the approach of fertility oneconomic development. Economic development based on the theories of Malthus: anincrease in "income" is slower than the increase in births (fertility and is the root ofpeople falling into poverty. However, Becker made linkage model or the influence ofchildren income and price. According to Becker, viewed from the aspect of demand thatthe price of children is greater than the income effect.The study shows that (1 level of education correlates positively on income andnegatively affect fertility, (2 age structure of women (control contraceptives adverselyaffect fertility. That is, the older the age, the level of individual productivity and lowerfertility or declining, and (3 husband's employment status correlated positively to theearnings (income. Through a permanent factor income or household income referred toas a negative influence on fertility. There are differences in value orientation of childrenbetween advanced society (rich with a backward society (the poor. The poor, forexample, the value of children is more production of goods. That is, children born moreemphasis on aspects of the number or the number of children owned (quantity, numberof children born by the poor is expected to help their parents at the age of retirement orno longer productive so that the child is expected to assist them in economic, security,and social security (insurance, while the developed (rich children are moreconsumption value or quality of the child.

  6. Latent stereopsis for motion in depth in strabismic amblyopia.

    Science.gov (United States)

    Hess, Robert F; Mansouri, Behzad; Thompson, Benjamin; Gheorghiu, Elena

    2009-10-01

    To investigate the residual stereo function of a group of 15 patients with strabismic amblyopia, by using motion-in-depth stimuli that allow discrimination of contributions from local disparity as opposed to those from local velocity mechanisms as a function of the rate of depth change. The stereo performance (percentage correct) was measured as a function of the rate of depth change for dynamic random dot stimuli that were either temporally correlated or uncorrelated. Residual stereoscopic function was demonstrated for motion in depth based on local disparity information in 2 of the 15 observers with strabismic amblyopia. The use of a neutral-density (ND) filter in front of the fixing eye enhanced motion-in-depth performance in four subjects randomly selected from the group that originally displayed only chance performance. This finding was true across temporal rate and for correlated and uncorrelated stimuli, suggesting that it was disparity based. The opposite occurred in a group of normal subjects. In a separate experiment, the hypothesis was that the beneficial effect of the ND filter is due to its contrast and/or mean luminance-reducing effects rather than any interocular time delay that it may introduce and that it is specific to motion-in-depth performance, as similar improvements were not found for static stereopsis. A small proportion of observers with strabismic amblyopia exhibit residual performance for motion in depth, and it is disparity based. Furthermore, some observers with strabismic amblyopia who do not display any significant stereo performance for motion in depth under normal binocular viewing may display above-chance stereo performance if the degree of interocular suppression is reduced. The authors term this phenomenon latent stereopsis.

  7. Human matching performance of genuine crime scene latent fingerprints.

    Science.gov (United States)

    Thompson, Matthew B; Tangen, Jason M; McCarthy, Duncan J

    2014-02-01

    There has been very little research into the nature and development of fingerprint matching expertise. Here we present the results of an experiment testing the claimed matching expertise of fingerprint examiners. Expert (n = 37), intermediate trainee (n = 8), new trainee (n = 9), and novice (n = 37) participants performed a fingerprint discrimination task involving genuine crime scene latent fingerprints, their matches, and highly similar distractors, in a signal detection paradigm. Results show that qualified, court-practicing fingerprint experts were exceedingly accurate compared with novices. Experts showed a conservative response bias, tending to err on the side of caution by making more errors of the sort that could allow a guilty person to escape detection than errors of the sort that could falsely incriminate an innocent person. The superior performance of experts was not simply a function of their ability to match prints, per se, but a result of their ability to identify the highly similar, but nonmatching fingerprints as such. Comparing these results with previous experiments, experts were even more conservative in their decision making when dealing with these genuine crime scene prints than when dealing with simulated crime scene prints, and this conservatism made them relatively less accurate overall. Intermediate trainees-despite their lack of qualification and average 3.5 years experience-performed about as accurately as qualified experts who had an average 17.5 years experience. New trainees-despite their 5-week, full-time training course or their 6 months experience-were not any better than novices at discriminating matching and similar nonmatching prints, they were just more conservative. Further research is required to determine the precise nature of fingerprint matching expertise and the factors that influence performance. The findings of this representative, lab-based experiment may have implications for the way fingerprint examiners testify in

  8. Internet Gamblers Differ on Social Variables: A Latent Class Analysis.

    Science.gov (United States)

    Khazaal, Yasser; Chatton, Anne; Achab, Sophia; Monney, Gregoire; Thorens, Gabriel; Dufour, Magali; Zullino, Daniele; Rothen, Stephane

    2017-09-01

    Online gambling has gained popularity in the last decade, leading to an important shift in how consumers engage in gambling and in the factors related to problem gambling and prevention. Indebtedness and loneliness have previously been associated with problem gambling. The current study aimed to characterize online gamblers in relation to indebtedness, loneliness, and several in-game social behaviors. The data set was obtained from 584 Internet gamblers recruited online through gambling websites and forums. Of these gamblers, 372 participants completed all study assessments and were included in the analyses. Questionnaires included those on sociodemographics and social variables (indebtedness, loneliness, in-game social behaviors), as well as the Gambling Motives Questionnaire, Gambling Related Cognitions Scale, Internet Addiction Test, Problem Gambling Severity Index, Short Depression-Happiness Scale, and UPPS-P Impulsive Behavior Scale. Social variables were explored with a latent class model. The clusters obtained were compared for psychological measures and three clusters were found: lonely indebted gamblers (cluster 1: 6.5%), not lonely not indebted gamblers (cluster 2: 75.4%), and not lonely indebted gamblers (cluster 3: 18%). Participants in clusters 1 and 3 (particularly in cluster 1) were at higher risk of problem gambling than were those in cluster 2. The three groups differed on most assessed variables, including the Problem Gambling Severity Index, the Short Depression-Happiness Scale, and the UPPS-P subscales (except the sensation seeking subscore). Results highlight significant between-group differences, suggesting that Internet gamblers are not a homogeneous group. Specific intervention strategies could be implemented for groups at risk.

  9. Comorbidity profiles of psoriasis in Taiwan: A latent class analysis.

    Science.gov (United States)

    Wu, Chen-Yi; Hu, Hsiao-Yun; Li, Chung-Pin; Chou, Yiing-Jeng; Chang, Yun-Ting

    2018-01-01

    Psoriasis is associated with many comorbidities. An understanding of these comorbidity patterns can help foster better care of patients with psoriasis. To identify the heterogeneity of psoriasis comorbidities using latent class analysis (LCA). LCA was used to empirically identify psoriasis comorbidity patterns in a nationwide sample of 110,729 incident cases of psoriasis (2002-2012) from the National Health Insurance database in Taiwan. The mean age of incident psoriasis was 46.1 years. Hypertension (28.8%), dyslipidemia (18.9%), and chronic liver disease/cirrhosis/hepatitis (18.1%) were the top three comorbidities in patients with psoriasis. LCA identified four distinct comorbidity classes among these patients, including 9.9% of patients in the "multi-comorbidity" class, 17.9% in the "metabolic syndrome" class, 11.3% in the "hypertension and chronic obstructive pulmonary disease (COPD)" class, and 60.9% in the "relatively healthy" class. Psoriatic arthritis was evenly distributed among each class. Relative to membership in the "relative healthy" class, an increase of one year of age had a higher probability of membership in the "multi-comorbidity" (odds ratio [OR], 1.25), "metabolic syndrome" (OR, 1.11), or "hypertension and COPD" (OR, 1.34) classes. Relative to membership in the "relative healthy" class, compared to women, men had a higher probability of membership in the "multi-comorbidity" (OR, 1.39), "metabolic syndrome" (OR, 1.77), or "hypertension and COPD" (OR, 1.22) classes. We observed four distinct classes of psoriasis comorbidities, including the "multi-comorbidity", "metabolic syndrome", "hypertension and COPD", and "relatively healthy" classes, as well as the clustering of liver diseases with metabolic syndrome and clustering of COPD with hypertension.

  10. Computerized summary scoring: crowdsourcing-based latent semantic analysis.

    Science.gov (United States)

    Li, Haiying; Cai, Zhiqiang; Graesser, Arthur C

    2017-11-03

    In this study we developed and evaluated a crowdsourcing-based latent semantic analysis (LSA) approach to computerized summary scoring (CSS). LSA is a frequently used mathematical component in CSS, where LSA similarity represents the extent to which the to-be-graded target summary is similar to a model summary or a set of exemplar summaries. Researchers have proposed different formulations of the model summary in previous studies, such as pregraded summaries, expert-generated summaries, or source texts. The former two methods, however, require substantial human time, effort, and costs in order to either grade or generate summaries. Using source texts does not require human effort, but it also does not predict human summary scores well. With human summary scores as the gold standard, in this study we evaluated the crowdsourcing LSA method by comparing it with seven other LSA methods that used sets of summaries from different sources (either experts or crowdsourced) of differing quality, along with source texts. Results showed that crowdsourcing LSA predicted human summary scores as well as expert-good and crowdsourcing-good summaries, and better than the other methods. A series of analyses with different numbers of crowdsourcing summaries demonstrated that the number (from 10 to 100) did not significantly affect performance. These findings imply that crowdsourcing LSA is a promising approach to CSS, because it saves human effort in generating the model summary while still yielding comparable performance. This approach to small-scale CSS provides a practical solution for instructors in courses, and also advances research on automated assessments in which student responses are expected to semantically converge on subject matter content.

  11. Micología en Bolivia: Un tema Latente

    Directory of Open Access Journals (Sweden)

    Fernando Pacasa-Quisbert

    2017-02-01

    Full Text Available El reino de los hongos es uno de los más diversos grupos de organismos en el planeta, están ampliamente distribuidos en la naturaleza, principalmente en ambientes terrestres y en menor proporción en ambientes acuáticos. Muchos científicos sugieren que el Reino de los Hongos seria hiperdiverso y podría superar los 3.5 M de especies (O’Brien et al. 2005. Muchas especies aun no fueron descritas y podrían estar presentes en ecosistemas tropicales, en ambientes no explorados, aunque también existirían especies cripticas. Bolivia es considerada como uno de los países megadiversos a nivel mundial en riqueza animal, vegetal, insectos y microorganismos, en su amplio territorio contiene diversos ecosistemas que ofrecen una amplia variedad de hábitats de esta riqueza. Las investigaciones micológicas se han concentrado en las ramas médicas y afines, estudiando patógenos de humanos y animales, pero ¿Cuál es el avance de la ciencia micológica en Bolivia con relación con otras ciencias como la Agronomía, Ecología, Medio Ambiente, Fitopatología, entre otras? Se han conseguido importantes avances en la descripción de la diversidad de plantas, animales e insectos, en cambio investigaciones en microbiología del suelo se han concentrado en el uso o aplicación de algún microorganismo benéfico para el control de plagas, enfermedades y promoción del crecimiento de las plantas en nuestro país. El reino de los hongos es hiperdiverso, pero escasamente estudiados en nuestro país, buscando exhaustivamente recursos en Google search con las frases: “diversidad de microorganismos del suelo en Bolivia”, “hongos de Bolivia” y “diversidad de hongos en Bolivia”, hay muy pocas investigaciones y referencias de nuestro país, a pesar de su importancia, la diversidad taxonómica, distribución de especies y funciones que desempeñan en los ecosistemas son poco documentadas en Bolivia. La amplia variedad de ecosistemas de Bolivia podr

  12. Algunas aclaraciones acerca del conocimiento del singular.

    Directory of Open Access Journals (Sweden)

    Carlos Llano Cifuentes

    2013-11-01

    Full Text Available Llano tries to explain the main purpose of El Conocimiento del Singular, showing how the individuals about which the book is concerned are basically human individuals: people as decision makers.

  13. Tratamento da tuberculose de infecção latente: As recomendações actuais Latent tuberculosis infection treatment: Current recommendations

    Directory of Open Access Journals (Sweden)

    R Duarte

    2010-09-01

    Full Text Available O diagnóstico e tratamento da infecção latente por Mycobacterium tuberculosis reduz significativamente o risco de desenvolvimento de tuberculose activa e a transmissão da doença na comunidade. O rastreio da tuberculose infecção latente deve passar pela exclusão de doença activa (inquérito de sintomas e radiografia pulmonar e avaliação da resposta imunológica ao M. tuberculosis através dos testes actualmente ao dispor, como o teste tuberculínico e os testes IGRA (interferon-gamma release assay. A escolha do esquema de tratamento deve ter em linha de conta a eficácia, a adesão e os efeitos colaterais associados ao mesmo Este documento actualiza as recomendações sobre tratamento da tuberculose infecção latente. São apresentadas indicações sobre quem deve ser rastreado e revistos os esquemas de tratamento.Diagnosis and treatment of latent infection with Mycobacterium tuberculosis (LTBI, significantly reduces the risk of developing active tuberculosis and the transmission of the disease in the community. LTBI screening must pass by the exclusion of active disease (symptoms enquiry and chest radiography and assessment of immune response to Mycobacterium tuberculosis testing with the tests currently available - tuberculin skin test and interferon-gamma release assay (IGRA. The choice of treatment must take into account the efficacy and side effects associated with the same. This document provides updated recommendations on latent tuberculosis infection treatment. Topics covered include whom to test for TB and reviewed LTBI treatment regimens.

  14. Effect of Latent Heat Released by Freezing Droplets during Frost Wave Propagation.

    Science.gov (United States)

    Chavan, Shreyas; Park, Deokgeun; Singla, Nitish; Sokalski, Peter; Boyina, Kalyan; Miljkovic, Nenad

    2018-05-21

    Frost spreads on nonwetting surfaces during condensation frosting via an interdroplet frost wave. When a supercooled condensate water droplet freezes on a hydrophobic or superhydrophobic surface, neighboring droplets still in the liquid phase begin to evaporate. Two possible mechanisms govern the evaporation of neighboring water droplets: (1) The difference in saturation pressure of the water vapor surrounding the liquid and frozen droplets induces a vapor pressure gradient, and (2) the latent heat released by freezing droplets locally heats the substrate, leading to evaporation of nearby droplets. The relative significance of these two mechanisms is still not understood. Here, we study the significance of the latent heat released into the substrate by freezing droplets, and its effect on adjacent droplet evaporation, by studying the dynamics of individual water droplet freezing on aluminum-, copper-, and glass-based hydrophobic and superhydrophobic surfaces. The latent heat flux released into the substrate was calculated from the measured droplet sizes and the respective freezing times ( t f ), defined as the time from initial ice nucleation within the droplet to complete droplet freezing. To probe the effect of latent heat release, we performed three-dimensional transient finite element simulations showing that the transfer of latent heat to neighboring droplets is insignificant and accounts for a negligible fraction of evaporation during microscale frost wave propagation. Furthermore, we studied the effect of substrate thermal conductivity on the transfer of latent heat transfer to neighboring droplets by investigating the velocity of ice bridge formation. The velocity of the ice bridge was independent of the substrate thermal conductivity, indicating that adjacent droplet evaporation during condensation frosting is governed solely by vapor pressure gradients. This study not only provides key insights into the individual droplet freezing process but also

  15. Rapid quantification of the latent reservoir for HIV-1 using a viral outgrowth assay.

    Directory of Open Access Journals (Sweden)

    Gregory M Laird

    Full Text Available HIV-1 persists in infected individuals in a stable pool of resting CD4(+ T cells as a latent but replication-competent provirus. This latent reservoir is the major barrier to the eradication of HIV-1. Clinical trials are currently underway investigating the effects of latency-disrupting compounds on the persistence of the latent reservoir in infected individuals. To accurately assess the effects of such compounds, accurate assays to measure the frequency of latently infected cells are essential. The development of a simpler assay for the latent reservoir has been identified as a major AIDS research priority. We report here the development and validation of a rapid viral outgrowth assay that quantifies the frequency of cells that can release replication-competent virus following cellular activation. This new assay utilizes bead and column-based purification of resting CD4(+ T cells from the peripheral blood of HIV-1 infected patients rather than cell sorting to obtain comparable resting CD4(+ T cell purity. This new assay also utilizes the MOLT-4/CCR5 cell line for viral expansion, producing statistically comparable measurements of the frequency of latent HIV-1 infection. Finally, this new assay employs a novel quantitative RT-PCR specific for polyadenylated HIV-1 RNA for virus detection, which we demonstrate is a more sensitive and cost-effective method to detect HIV-1 replication than expensive commercial ELISA detection methods. The reductions in both labor and cost make this assay suitable for quantifying the frequency of latently infected cells in clinical trials of HIV-1 eradication strategies.

  16. Reliability measures in item response theory: manifest versus latent correlation functions.

    Science.gov (United States)

    Milanzi, Elasma; Molenberghs, Geert; Alonso, Ariel; Verbeke, Geert; De Boeck, Paul

    2015-02-01

    For item response theory (IRT) models, which belong to the class of generalized linear or non-linear mixed models, reliability at the scale of observed scores (i.e., manifest correlation) is more difficult to calculate than latent correlation based reliability, but usually of greater scientific interest. This is not least because it cannot be calculated explicitly when the logit link is used in conjunction with normal random effects. As such, approximations such as Fisher's information coefficient, Cronbach's α, or the latent correlation are calculated, allegedly because it is easy to do so. Cronbach's α has well-known and serious drawbacks, Fisher's information is not meaningful under certain circumstances, and there is an important but often overlooked difference between latent and manifest correlations. Here, manifest correlation refers to correlation between observed scores, while latent correlation refers to correlation between scores at the latent (e.g., logit or probit) scale. Thus, using one in place of the other can lead to erroneous conclusions. Taylor series based reliability measures, which are based on manifest correlation functions, are derived and a careful comparison of reliability measures based on latent correlations, Fisher's information, and exact reliability is carried out. The latent correlations are virtually always considerably higher than their manifest counterparts, Fisher's information measure shows no coherent behaviour (it is even negative in some cases), while the newly introduced Taylor series based approximations reflect the exact reliability very closely. Comparisons among the various types of correlations, for various IRT models, are made using algebraic expressions, Monte Carlo simulations, and data analysis. Given the light computational burden and the performance of Taylor series based reliability measures, their use is recommended. © 2014 The British Psychological Society.

  17. Latent Fairness in Adults' Relationship-Based Moral Judgments.

    Science.gov (United States)

    Hao, Jian; Liu, Yanchun; Li, Jiafeng

    2015-01-01

    two experiments. Therefore, the present study shows that, in addition to apparent unfairness, latent fairness exists in adults' relationship-based moral judgments. Moral judgments involving individuals with whom adults have different relationships have different cognitive and affective bases.

  18. Latent Fairness in Adults’ Relationship-Based Moral Judgments

    Science.gov (United States)

    Hao, Jian; Liu, Yanchun; Li, Jiafeng

    2015-01-01

    previous two experiments. Therefore, the present study shows that, in addition to apparent unfairness, latent fairness exists in adults’ relationship-based moral judgments. Moral judgments involving individuals with whom adults have different relationships have different cognitive and affective bases. PMID:26696935

  19. 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

  20. Environmental Forcing of Supertyphoon Paka's (1997) Latent Heat Structure.

    Science.gov (United States)

    Rodgers, Edward; Olson, William; Halverson, Jeff; Simpson, Joanne; Pierce, Harold

    2000-12-01

    The distribution and intensity of total (i.e., combined stratified and convective processes) rain rate/latent heat release (LHR) were derived for Tropical Cyclone Paka during the period 9-21 December 1997 from the F-10, F-11, F-13, and F-14 Defense Meteorological Satellite Special Sensor Microwave Imager and the Tropical Rainfall Measuring Mission Microwave Imager observations. These observations were frequent enough to capture three episodes of inner-core convective bursts and a convective rainband cycle that preceded periods of rapid intensification. During these periods of convective bursts, satellite sensors revealed that the rain rates/LHR 1) increased within the inner-core region, 2) were mainly convectively generated (nearly a 65% contribution), 3) propagated inward, 4) extended upward within the mid- and upper troposphere, and 5) became electrically charged. These factors may have increased the areal mean ascending motion in the mid- and upper-troposphere eyewall region, creating greater cyclonic angular momentum, and, thereby, warming the center and intensifying the system.Radiosonde measurements from Kwajalein Atoll and Guam, sea surface temperature observations, and the European Centre for Medium-Range Forecasts analyses were used to examine the necessary and sufficient conditions for initiating and maintaining these inner-core convective bursts. For example, the necessary conditions such as the atmospheric thermodynamics [i.e., cold tropopause temperatures, moist troposphere, and warm SSTs (>26°C)] fulfill the necessary conditions and suggested that the atmosphere was ideally suited for Paka's maximum potential intensity to approach supertyphoon strength. Further, Paka encountered moderate vertical wind shear (<15 m s1) before interacting with the westerlies on 21 December. The sufficient conditions that include horizontal moisture and the upper-tropospheric eddy relative angular momentum fluxes, on the other hand, appeared to have some influence on

  1. Psicodrama del duelo.

    OpenAIRE

    José Antonio Espina Barrio; Marisol Filgueira Bouza

    1997-01-01

    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.

  2. Valor de la determinación de anticuerpos antitiroideos plasmáticos para el diagnóstico de tiroiditis crónica autoinmune Value of the determination of plasmatic antithyroid antibodies for the diagnosis of chronic autoimmune thyroiditis

    Directory of Open Access Journals (Sweden)

    Francisco Ochoa Torres

    2001-08-01

    Full Text Available Se valoró la eficacia de los métodos de detección de anticuerpos humorales empleados en el Instituto Nacional de Endocrinología para el diagnóstico de TCA. Se estudió un grupo de 100 pacientes con bocio y la sospecha clínica de que padecieran de TCA. A cada uno se le realizó una biopsia con aguja fina (BAF, que se tomó como la regla de oro del diagnóstico, determinación de anticuerpos plasmáticos antitiroglobulina por el método del TRC y antimicrosomales (AMS, para hacer una validación estadística de ambos métodos; sensibilidad, especificidad, valor predictivo para casos positivos, valor predictivo para casos negativos y el índice general de eficacia diagnóstica. Se hallaron 70 pacientes con resultados positivos de TCA por la BAF y 30, negativos. La sensibilidad de ambos métodos de detección de anticuerpos humorales fue pobre (45,7 % para el AMS y 30 % para el TRC. Aún aplicados los dos al mismo paciente no sobrepasó del 60 %. La especificidad fue mucho mejor para ambos métodos (73,3 % para la AMS, 90 % para el TRC y 70 % para ambos métodos juntos. El valor predictivo para casos positivos fue bueno (80 % para AMS, 87,5 % para TRC y 82,3 % para los métodos de conjunto y el predictivo para casos negativos fue 36,3, 35,5 y 42,9 %, respectivamente. La eficacia general fue tan solo del 54 % para el TRC, 48 % para AMS y 63 % para ambos métodos de conjunto. Se concluyó que estos métodos son útiles para reafirmar el diagnóstico cuando resultan positivos, pero de poca utilidad para asegurar que no se trata de esta afección cuando resultan negativosThe effectiveness of the humoral antibody detection methods used in the diagnosis of chronic autoimmune thyroiditis (CAT in the National Institute of Endocrinology was assessed. A group of 100 patients with goitier and presenting with clinical suspicion of CAT was studied. A fine needle biopsy was performed on each of the patients, which was taken as the golden rule of the

  3. 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.

  4. Vigencia del Darwinismo

    OpenAIRE

    Lessa, Enrique P

    2009-01-01

    En este ensayo se presenta una revisión histórica del signifcado y legado del darwinismo, con énfasis en el último siglo. La principal conclusión es que la visión darwiniana de la evolución, con las modifcaciones requeridas para dar cuenta de los grandes desarrollos de la disciplina, se ha impuesto y mantiene vigencia en nuestros días. En particular, el papel del azar, la evolución como proceso de “descendencia con modifcación” a lo largo de diversas ramas del árbol de la vida, el pensamiento...

  5. Altered intrinsic functional connectivity in the latent period of epileptogenesis in a temporal lobe epilepsy model.

    Science.gov (United States)

    Lee, Hyoin; Jung, Seungmoon; Lee, Peter; Jeong, Yong

    2017-10-01

    The latent period, a seizure-free phase, is the duration between brain injury and the onset of spontaneous recurrent seizures (SRSs) during epileptogenesis. The latent period is thought to involve several progressive pathophysiological events that lead to the evolution of the chronic epilepsy phase. Hence, it is vital to investigate the changes in the latent period during epileptogenesis in order to better understand temporal lobe epilepsy (TLE), and to achieve early diagnosis and appropriate management of the condition. Accordingly, recent studies with patients with TLE using resting-state functional magnetic resonance imaging (rs-fMRI) have reported that alterations of resting-state functional connectivity (rsFC) during the chronic period are associated with some clinical manifestations, including learning and memory impairments, emotional instability, and social behavior deficits, in addition to repetitive seizure episodes. In contrast, the changes in the intrinsic rsFC during epileptogenesis, particularly during the latent period, remain unclear. In this study, we investigated the alterations in intrinsic rsFC during the latent and chronic periods in a pilocarpine-induced TLE mouse model using intrinsic optical signal imaging (IOSI). This technique can monitor the changes in the local hemoglobin concentration according to neuronal activity and can help investigate large-scale brain intrinsic networks. After seeding on the anatomical regions of interest (ROIs) and calculating the correlation coefficients between each ROI, we established and compared functional correlation matrices and functional connectivity maps during the latent and chronic periods of epilepsy. We found a decrease in the interhemispheric rsFC at the frontal and temporal regions during both the latent and chronic periods. Furthermore, a significant decrease in the interhemispheric rsFC was observed in the somatosensory area during the chronic period. Changes in network configurations during

  6. Latent myostatin has significant activity and this activity is controlled more efficiently by WFIKKN1 than by WFIKKN2

    OpenAIRE

    Szláma, György; Trexler, Mária; Patthy, László

    2013-01-01

    Myostatin, a negative regulator of skeletal muscle growth, is produced from myostatin precursor by multiple steps of proteolytic processing. After cleavage by a furin-type protease, the propeptide and growth factor domains remain associated, forming a noncovalent complex, the latent myostatin complex. Mature myostatin is liberated from latent myostatin by bone morphogenetic protein 1/tolloid proteases. Here, we show that, in reporter assays, latent myostatin preparations have significant myos...

  7. APLICACIÓN DE UN MODELO FACTORIAL CONFIRMATORIO PARA ENCONTRAR LOS FACTORES LATENTES QUE DETERMINAN LA CALIDAD DE VIDA PERCIBIDA

    Directory of Open Access Journals (Sweden)

    Valeria Gogni

    2016-08-01

    Full Text Available Tanto a nivel teórico como práctico, no existe un consenso acerca de qué se entiende por Calidad de Vida dado que este concepto posee un carácter complejo y multidimensional. En algunos casos, la satisfacción de vida se equipara con la Calidad de Vida y se refiere a la evaluación subjetiva que realiza un individuo del grado en el cual sus necesidades, deseos y metas más importantes se encuentran realizadas. Se asume que la satisfacción de vida total de una persona consiste en una amplia suma de satisfacciones en áreas particulares de la vida que son valoradas o juzgadas importantes, considerando que es un estado fluctuante y no un rasgo constante [6]. Campbell [4] plantea que la satisfacción de una persona en un área particular se integra con diversas componentes que cubren los distintos aspectos de la vida de una persona y que son evaluados subjetivamente por los individuos tanto en lo referido a la importancia en su contexto vital, como en relación a su felicidad o bienestar en dichos aspectos. En este trabajo, se evalúa la validez de este modelo teórico en la población de la ciudad de Buenos Aires, Argentina, mediante el ajuste de un modelo de Análisis Factorial Confirmatorio de segundo orden, aplicado a los ítems de una prueba que mide la calidad de vida percibida por los sujetos. El modelo se aplicó sobre una muestra de 1336 individuos de entre 18 y 65 años y los resultados del Análisis Factorial Confirmatorio muestran que la calidad de vida percibida por los sujetos está en estrecha relación con su nivel de satisfacción con una serie dimensiones o factores latentes: Ambiente o hábitat del sujeto, su Necesidad de trascendencia,las Redes sociales que lo contienen, y su Crecimiento Personal.

  8. A latent transition model of the effects of a teen dating violence prevention initiative.

    Science.gov (United States)

    Williams, Jason; Miller, Shari; Cutbush, Stacey; Gibbs, Deborah; Clinton-Sherrod, Monique; Jones, Sarah

    2015-02-01

    Patterns of physical and psychological teen dating violence (TDV) perpetration, victimization, and related behaviors were examined with data from the evaluation of the Start Strong: Building Healthy Teen Relationships initiative, a dating violence primary prevention program targeting middle school students. Latent class and latent transition models were used to estimate distinct patterns of TDV and related behaviors of bullying and sexual harassment in seventh grade students at baseline and to estimate transition probabilities from one pattern of behavior to another at the 1-year follow-up. Intervention effects were estimated by conditioning transitions on exposure to Start Strong. Latent class analyses suggested four classes best captured patterns of these interrelated behaviors. Classes were characterized by elevated perpetration and victimization on most behaviors (the multiproblem class), bullying perpetration/victimization and sexual harassment victimization (the bully-harassment victimization class), bullying perpetration/victimization and psychological TDV victimization (bully-psychological victimization), and experience of bully victimization (bully victimization). Latent transition models indicated greater stability of class membership in the comparison group. Intervention students were less likely to transition to the most problematic pattern and more likely to transition to the least problem class. Although Start Strong has not been found to significantly change TDV, alternative evaluation models may find important differences. Latent transition analysis models suggest positive intervention impact, especially for the transitions at the most and the least positive end of the spectrum. Copyright © 2015. Published by Elsevier Inc.

  9. Examination of the change in latent statuses in bullying behaviors across time.

    Science.gov (United States)

    Ryoo, Ji Hoon; Wang, Cixin; Swearer, Susan M

    2015-03-01

    Involvement in bullying and victimization has been mostly studied using cross-sectional data from 1 time point. As such, much of our understanding of bullying and victimization has not captured the dynamic experiences of youth over time. To examine the change of latent statuses in bullying and victimization, we applied latent transition analysis examining self-reported bullying involvement from 1,180 students in 5th through 9th grades across 3 time points. We identified unobserved heterogeneous subgroups (i.e., latent statuses) and investigated how students transition between the unobserved subgroups over time. For victimization, 4 latent statuses were identified: frequent victim (11.23%), occasional traditional victim (28.86%), occasional cyber and traditional victim (10.34%), and infrequent victim (49.57%). For bullying behavior, 3 latent statuses were identified: frequent perpetrator (5.12%), occasional verbal/relational perpetrator (26.04%), and infrequent perpetrator (68.84%). The characteristics of the transitions were examined. The multiple-group effects of gender, grade, and first language learned on transitions across statuses were also investigated. The infrequent victim and infrequent perpetrator groups were the most stable, and the frequent victim and frequent perpetrator groups were the least stable. These findings suggest instability in perpetration and victimization over time, as well as significant changes, especially during school transition years. Findings suggest that school-based interventions need to address the heterogeneity in perpetrator and victim experiences in adolescence.

  10. Reactivation of Latent Epstein-Barr Virus; A Comparison After Gamma Rays and Proton Treatment

    Science.gov (United States)

    Mehta, Satish K.; Plante, Ianik; Bloom, David C.; Stowe, Raymond; Renner, Ashlie; Wu, Honglu; Crucian, Brian; Pierson, Duane L.

    2017-01-01

    Among different unique stressors astronauts are exposed to during spaceflight, cosmic radiation constitutes an important one that leads to various health effects. In particular, space radiation may contribute to decreased immunity, which has been observed in astronauts during short and long duration missions, as evidenced by several changes in cellular immunity and plasma cytokines levels. Reactivation of latent herpes viruses, either directly from radiation or resulting from perturbation in the immune system, is also observed in astronauts. While EBV is one of the eight human herpes viruses known to infect more than 90% human adults and stays latent for the life of the host without normally causing adverse effects of reactivation, increased reactivation in astronauts is well-documented, though the mechanism of this increase is not understood. In this work, we have studied the effect of two different types of radiations, Cs-137 gamma and 150-MeV proton on the reactivation rates of the Epstein - Barr virus (EBV) in vitro in EBV latent cell lines at doses of 0.1, 0.5, 1.0 and 2.0 Gy. While we find that both types of radiations reactivated latent EBV in vitro, we observe that at equivalent doses, early response is stronger for protons but with time, the reactivation induced by gamma rays is more persistent. These differences between the protons and gamma rays curves in latent virus reactivation challenge the common paradigm that protons and gamma rays have similar biological effects.

  11. Forensic Discrimination of Latent Fingerprints Using Laser-Induced Breakdown Spectroscopy (LIBS) and Chemometric Approaches.

    Science.gov (United States)

    Yang, Jun-Ho; Yoh, Jack J

    2018-01-01

    A novel technique is reported for separating overlapping latent fingerprints using chemometric approaches that combine laser-induced breakdown spectroscopy (LIBS) and multivariate analysis. The LIBS technique provides the capability of real time analysis and high frequency scanning as well as the data regarding the chemical composition of overlapping latent fingerprints. These spectra offer valuable information for the classification and reconstruction of overlapping latent fingerprints by implementing appropriate statistical multivariate analysis. The current study employs principal component analysis and partial least square methods for the classification of latent fingerprints from the LIBS spectra. This technique was successfully demonstrated through a classification study of four distinct latent fingerprints using classification methods such as soft independent modeling of class analogy (SIMCA) and partial least squares discriminant analysis (PLS-DA). The novel method yielded an accuracy of more than 85% and was proven to be sufficiently robust. Furthermore, through laser scanning analysis at a spatial interval of 125 µm, the overlapping fingerprints were reconstructed as separate two-dimensional forms.

  12. Sensible and latent heat forced divergent circulations in the West African Monsoon System

    Science.gov (United States)

    Hagos, S.; Zhang, C.

    2008-12-01

    Field properties of divergent circulation are utilized to identify the roles of various diabatic processes in forcing moisture transport in the dynamics of the West African Monsoon and its seasonal cycle. In this analysis, the divergence field is treated as a set of point sources and is partitioned into two sub-sets corresponding to latent heat release and surface sensible heat flux at each respective point. The divergent circulation associated with each set is then calculated from the Poisson's equation using Gauss-Seidel iteration. Moisture transport by each set of divergent circulation is subsequently estimated. The results show different roles of the divergent circulations forced by surface sensible and latent heating in the monsoon dynamics. Surface sensible heating drives a shallow meridional circulation, which transports moisture deep into the continent at the polar side of the monsoon rain band and thereby promotes the seasonal northward migration of monsoon precipitation during the monsoon onset season. In contrast, the circulation directly associated with latent heating is deep and the corresponding moisture convergence is within the region of precipitation. Latent heating also induces dry air advection from the north. Neither effect promotes the seasonal northward migration of precipitation. The relative contributions of the processes associated with latent and sensible heating to the net moisture convergence, and hence the seasonal evolution of monsoon precipitation, depend on the background moisture.

  13. Short-term memory development: differences in serial position curves between age groups and latent classes.

    Science.gov (United States)

    Koppenol-Gonzalez, Gabriela V; Bouwmeester, Samantha; Vermunt, Jeroen K

    2014-10-01

    In studies on the development of cognitive processes, children are often grouped based on their ages before analyzing the data. After the analysis, the differences between age groups are interpreted as developmental differences. We argue that this approach is problematic because the variance in cognitive performance within an age group is considered to be measurement error. However, if a part of this variance is systematic, it can provide very useful information about the cognitive processes used by some children of a certain age but not others. In the current study, we presented 210 children aged 5 to 12 years with serial order short-term memory tasks. First we analyze our data according to the approach using age groups, and then we apply latent class analysis to form latent classes of children based on their performance instead of their ages. We display the results of the age groups and the latent classes in terms of serial position curves, and we discuss the differences in results. Our findings show that there are considerable differences in performance between the age groups and the latent classes. We interpret our findings as indicating that the latent class analysis yielded a much more meaningful way of grouping children in terms of cognitive processes than the a priori grouping of children based on their ages. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. New approaches for examining associations with latent categorical variables: applications to substance abuse and aggression.

    Science.gov (United States)

    Feingold, Alan; Tiberio, Stacey S; Capaldi, Deborah M

    2014-03-01

    Assessments of substance use behaviors often include categorical variables that are frequently related to other measures using logistic regression or chi-square analysis. When the categorical variable is latent (e.g., extracted from a latent class analysis [LCA]), classification of observations is often used to create an observed nominal variable from the latent one for use in a subsequent analysis. However, recent simulation studies have found that this classical 3-step analysis championed by the pioneers of LCA produces underestimates of the associations of latent classes with other variables. Two preferable but underused alternatives for examining such linkages-each of which is most appropriate under certain conditions-are (a) 3-step analysis, which corrects the underestimation bias of the classical approach, and (b) 1-step analysis. The purpose of this article is to dissuade researchers from conducting classical 3-step analysis and to promote the use of the 2 newer approaches that are described and compared. In addition, the applications of these newer models-for use when the independent, the dependent, or both categorical variables are latent-are illustrated through substantive analyses relating classes of substance abusers to classes of intimate partner aggressors.

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

    International Nuclear Information System (INIS)

    Ban-Weiss, George A; Cao Long; Pongratz, Julia; Caldeira, Ken; Bala, Govindasamy

    2011-01-01

    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.

  16. 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.

  17. Transcriptional regulation of latent feline immunodeficiency virus in peripheral CD4+ T-lymphocytes.

    Science.gov (United States)

    McDonnel, Samantha J; Sparger, Ellen E; Luciw, Paul A; Murphy, Brian G

    2012-05-01

    Feline immunodeficiency virus (FIV), the lentivirus of domestic cats responsible for feline AIDS, establishes a latent infection in peripheral blood CD4+ T-cells approximately eight months after experimental inoculation. In this study, cats experimentally infected with the FIV-C strain in the asymptomatic phase demonstrated an estimated viral load of 1 infected cell per approximately 10(3) CD4+ T-cells, with about 1 copy of viral DNA per cell. Approximately 1 in 10 proviral copies was capable of transcription in the asymptomatic phase. The latent FIV proviral promoter was associated with deacetylated, methylated histones, which is consistent with a condensed chromatin structure. In contrast, the transcriptionally active FIV promoter was associated with histone acetylation and demethylation. In addition, RNA polymerase II appeared to be paused on the latent viral promoter, and short promoter-proximal transcripts were detected. Our findings for the FIV promoter in infected cats are similar to results obtained in studies of human immunodeficiency virus (HIV)-1 latent proviruses in cell culture in vitro studies. Thus, the FIV/cat model may offer insights into in vivo mechanisms of HIV latency and provides a unique opportunity to test novel therapeutic interventions aimed at eradicating latent virus.

  18. Transcriptional Regulation of Latent Feline Immunodeficiency Virus in Peripheral CD4+ T-lymphocytes

    Directory of Open Access Journals (Sweden)

    Brian G. Murphy

    2012-05-01

    Full Text Available Feline immunodeficiency virus (FIV, the lentivirus of domestic cats responsible for feline AIDS, establishes a latent infection in peripheral blood CD4+ T-cells approximately eight months after experimental inoculation. In this study, cats experimentally infected with the FIV-C strain in the asymptomatic phase demonstrated an estimated viral load of 1 infected cell per approximately 103 CD4+ T-cells, with about 1 copy of viral DNA per cell. Approximately 1 in 10 proviral copies was capable of transcription in the asymptomatic phase. The latent FIV proviral promoter was associated with deacetylated, methylated histones, which is consistent with a condensed chromatin structure. In contrast, the transcriptionally active FIV promoter was associated with histone acetylation and demethylation. In addition, RNA polymerase II appeared to be paused on the latent viral promoter, and short promoter-proximal transcripts were detected. Our findings for the FIV promoter in infected cats are similar to results obtained in studies of human immunodeficiency virus (HIV-1 latent proviruses in cell culture in vitro studies. Thus, the FIV/cat model may offer insights into in vivo mechanisms of HIV latency and provides a unique opportunity to test novel therapeutic interventions aimed at eradicating latent virus.

  19. 31P-magnetic resonance spectroscopy: Impaired energy metabolism in latent hyperthyroidism

    International Nuclear Information System (INIS)

    Theissen, P.; Kaldewey, S.; Moka, D.; Bunke, J.; Voth, E.; Schicha, H.

    1993-01-01

    31 Phosphorous magnetic resonance spectroscopy allows an in vivo examination of energy metabolism. The present study was designed to evaluate whether in patients with latent hyperthyroidism alterations of muscle energy metabolism could be found similar to those observed in patients with overt hyperthyroidism. In 10 patients with overt hyperthyroidism before therapy and 20 with latent hyperthyroidism (also without therapy) and in 24 healthy volunteers magnetic resonance spectroscopy of the calf muscle was performed within a 1.5-Tesla magnet. Muscle concentrations of phosphocreatine, inorganic phosphate, and ATP were quantified compared to an external standard solution of K 2 HPO 4 . In the patients with overt hyperthyroidism and with latent hyperthyroidism a significant decrease of phosphocreatine was found. Further, the ATP concentration in patients with latent and manifest hyperthyroidism tended towards lower values. There were no significant differences in the decrease of phosphocreatine and ATP between both patient groups. Therefore, this study for the first time shows that alterations of energy metabolism in latent hyperthyroidism can be measured and that they are similar to those observed in overt hyperthyroidism. (orig.) [de

  20. Mycobacteria-specific cytokine responses as correlates of treatment response in active and latent tuberculosis.

    Science.gov (United States)

    Clifford, Vanessa; Tebruegge, Marc; Zufferey, Christel; Germano, Susie; Forbes, Ben; Cosentino, Lucy; McBryde, Emma; Eisen, Damon; Robins-Browne, Roy; Street, Alan; Denholm, Justin; Curtis, Nigel

    2017-08-01

    A biomarker indicating successful tuberculosis (TB) therapy would assist in determining appropriate length of treatment. This study aimed to determine changes in mycobacteria-specific antigen-induced cytokine biomarkers in patients receiving therapy for latent or active TB, to identify biomarkers potentially correlating with treatment success. A total of 33 adults with active TB and 36 with latent TB were followed longitudinally over therapy. Whole blood stimulation assays using mycobacteria-specific antigens (CFP-10, ESAT-6, PPD) were done on samples obtained at 0, 1, 3, 6 and 9 months. Cytokine responses (IFN-γ, IL-1ra, IL-2, IL-10, IL-13, IP-10, MIP-1β, and TNF-α) in supernatants were measured by Luminex xMAP immunoassay. In active TB cases, median IL-1ra (with CFP-10 and with PPD stimulation), IP-10 (CFP-10, ESAT-6), MIP-1β (ESAT-6, PPD), and TNF-α (ESAT-6) responses declined significantly over the course of therapy. In latent TB cases, median IL-1ra (CFP-10, ESAT-6, PPD), IL-2 (CFP-10, ESAT-6), and IP-10 (CFP-10, ESAT-6) responses declined significantly. Mycobacteria-specific cytokine responses change significantly over the course of therapy, and their kinetics in active TB differ from those observed in latent TB. In particular, mycobacteria-specific IL-1ra responses are potential correlates of successful therapy in both active and latent TB. Copyright © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  1. Accuracy of latent-variable estimation in Bayesian semi-supervised learning.

    Science.gov (United States)

    Yamazaki, Keisuke

    2015-09-01

    Hierarchical probabilistic models, such as Gaussian mixture models, are widely used for unsupervised learning tasks. These models consist of observable and latent variables, which represent the observable data and the underlying data-generation process, respectively. Unsupervised learning tasks, such as cluster analysis, are regarded as estimations of latent variables based on the observable ones. The estimation of latent variables in semi-supervised learning, where some labels are observed, will be more precise than that in unsupervised, and one of the concerns is to clarify the effect of the labeled data. However, there has not been sufficient theoretical analysis of the accuracy of the estimation of latent variables. In a previous study, a distribution-based error function was formulated, and its asymptotic form was calculated for unsupervised learning with generative models. It has been shown that, for the estimation of latent variables, the Bayes method is more accurate than the maximum-likelihood method. The present paper reveals the asymptotic forms of the error function in Bayesian semi-supervised learning for both discriminative and generative models. The results show that the generative model, which uses all of the given data, performs better when the model is well specified. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Longitudinal Physical Activity Patterns Among Older Adults: A Latent Transition Analysis.

    Science.gov (United States)

    Mooney, Stephen J; Joshi, Spruha; Cerdá, Magdalena; Kennedy, Gary J; Beard, John R; Rundle, Andrew G

    2018-05-14

    Most epidemiologic studies of physical activity measure either total energy expenditure or engagement in a single activity type, such as walking. These approaches may gloss over important nuances in activity patterns. We performed a latent transition analysis to identify patterns of activity types as well as neighborhood and individual determinants of changes in those activity patterns over two years in a cohort of 2,023 older adult residents of New York City, NY, surveyed between 2011 and 2013. We identified seven latent classes: 1) Mostly Inactive, 2) Walking, 3) Exercise, 4) Household Activities and Walking, 5) Household Activities and Exercise, 6) Gardening and Household Activities, and 7) Gardening, Household Activities, and Exercise. The majority of subjects retained the same activity patterns between waves (54% unchanged between waves 1 and 2, 66% unchanged between waves 2 and 3).Most latent class transitions were between classes distinguished only by one form of activity, and only neighborhood unemployment was consistently associated with changing between activity latent classes. Future latent transition analyses of physical activity would benefit from larger cohorts and longer follow-up periods to assess predictors of and long-term impacts of changes in activity patterns.

  3. A Cell Culture Model of Latent and Lytic Herpes Simplex Virus Type 1 Infection in Spiral Ganglion.

    Science.gov (United States)

    Liu, Yuehong; Li, Shufeng

    2015-01-01

    Reactivation of latent herpes simplex virus type 1 (HSV-1) in spiral ganglion neurons (SGNs) is supposed to be one of the causes of idiopathic sudden sensorineural hearing loss. This study aims to establish a cell culture model of latent and lytic HSV-1 infection in spiral ganglia. In the presence of acyclovir, primary cultures of SGNs were latently infected with HSV-1 expressing green fluorescent protein. Four days later, these cells were treated with trichostatin A (TSA), a known chemical reactivator of HSV-1. TCID50 was used to measure the titers of virus in cultures on Vero cells. RNA from cultures was detected for the presence of transcripts of ICP27 and latency-associated transcript (LAT) using reverse transcription polymerase chain reaction. There is no detectable infectious HSV-1 in latently infected cultures, whereas they could be observed in both lytically infected and latently infected/TSA-treated cultures. LAT was the only detectable transcript during latent infection, whereas lytic ICP27 transcript was detected in lytically infected and latently infected/TSA-treated cultures. Cultured SGNs can be both latently and lytically infected with HSV-1. Furthermore, latently infected SGNs can be reactivated using TSA, yielding infectious virus.

  4. La luz del origen del universo

    Directory of Open Access Journals (Sweden)

    Casas, Alberto

    2015-10-01

    Full Text Available Penzias and Wilson discovered the cosmic microwave background, a luminous echo of the Big Bang, in 1965. The amount of information encoded in this relic of the early universe is truly extraordinary. At present, the most precise data about the origin and structure of the universe comes from the study of this primordial light, the full potential of which has yet to be explored.En 1965 se descubrió el fondo de radiación de microondas, un eco luminoso de la Gran Explosión (Big Bang. La cantidad de información contenida en esta reliquia del universo primitivo es verdaderamente extraordinaria. En la actualidad los datos más precisos sobre el origen y estructura del universo provienen del estudio de esta luz primigenia, que aún no ha sido explorada en todo su potencial.

  5. 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.

  6. 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.

  7. Does Attention-Deficit/Hyperactivity Disorder Have a Dimensional Latent Structure? A Taxometric Analysis

    Science.gov (United States)

    Marcus, David K.; Barry, Tammy D.

    2010-01-01

    An understanding of the latent structure of attention-deficit/hyperactivity disorder (ADHD) is essential for developing causal models of this disorder. Although some researchers have presumed that ADHD is dimensional and others have assumed that it is taxonic, there has been relatively little research directly examining the latent structure of ADHD. The authors conducted a set of taxometric analyses using data from the NICHD Study of Early Child Care and Youth Development (ns between 667–1078). The results revealed a dimensional latent structure across a variety of different analyses and sets of indicators, for inattention, hyperactivity/impulsivity, and ADHD. Furthermore, analyses of correlations with associated features indicated that dimensional models demonstrated stronger validity coefficients with these criterion measures than dichotomous models. These findings jibe with recent research on the genetic basis of ADHD and with contemporary models of ADHD. PMID:20973595

  8. Characterization of a Latent Virus-Like Infection of Symbiotic Zooxanthellae▿

    Science.gov (United States)

    Lohr, Jayme; Munn, Colin B.; Wilson, William H.

    2007-01-01

    A latent virus-like agent, which we designated zooxanthella filamentous virus 1 (ZFV1), was isolated from Symbiodinium sp. strain CCMP 2465 and characterized. Transmission electron microscopy and analytical flow cytometry revealed the presence of a new group of distinctive filamentous virus-like particles after exposure of the zooxanthellae to UV light. Examination of thin sections of the zooxanthellae revealed the formation and proliferation of filamentous virus-like particles in the UV-induced cells. Assessment of Symbiodinium sp. cultures was used here as a model to show the effects of UV irradiance and induction of potential latent viruses. The unique host-virus system described here provides insight into the role of latent infections in zooxanthellae through environmentally regulated viral induction mechanisms. PMID:17351090

  9. Characterization of a latent virus-like infection of symbiotic zooxanthellae.

    Science.gov (United States)

    Lohr, Jayme; Munn, Colin B; Wilson, William H

    2007-05-01

    A latent virus-like agent, which we designated zooxanthella filamentous virus 1 (ZFV1), was isolated from Symbiodinium sp. strain CCMP 2465 and characterized. Transmission electron microscopy and analytical flow cytometry revealed the presence of a new group of distinctive filamentous virus-like particles after exposure of the zooxanthellae to UV light. Examination of thin sections of the zooxanthellae revealed the formation and proliferation of filamentous virus-like particles in the UV-induced cells. Assessment of Symbiodinium sp. cultures was used here as a model to show the effects of UV irradiance and induction of potential latent viruses. The unique host-virus system described here provides insight into the role of latent infections in zooxanthellae through environmentally regulated viral induction mechanisms.

  10. Extra Heat Loss Through Light Weight Roofs Due to Latent Heat

    DEFF Research Database (Denmark)

    Rode, Carsten

    1996-01-01

    that changes phase at the terminals of its passage.Note however, that convection of air most often will have an important effect on the overall heat flow - but that is a different topic.Macroscopic latent heat transferConsider the following scenario: Initially, moisture is present in its condensed or frozen......This report is one in a series of papers in Task 5 of IEA Annex 24 on how moisture and air movements affect the energy performance of building constructions. The effect of latent heat flow will be demonstrated by means of an example: a light weight flat roof.Latent heat flow is one of three...... processes by which moisture affects energy performance:Higher thermal conductivityMoist materials have higher thermal con-ductivity than when they are dry. This is because thermally conducting moisture replaces the better insulating air in the pores of the materials. Moisture also enhan-ces the thermal...

  11. A Modified Electrostatic Adsorption Apparatus for Latent Fingerprint Development on Unfired Cartridge Cases.

    Science.gov (United States)

    Xu, Jingyang; Zhang, Ziyuan; Zheng, Xiaochun; Bond, John W

    2017-05-01

    Visualization of latent fingerprints on metallic surfaces by the method of applying electrostatic charging and adsorption is considered as a promising chemical-free method, which has the merit of nondestruction, and is considered to be effective for some difficult situations such as aged fingerprint deposits or those exposed to environmental extremes. In fact, a portable electrostatic generator can be easily accessible in a local forensic technology laboratory, which is already widely used in the visualization of footwear impressions. In this study, a modified version of this electrostatic apparatus is proposed for latent fingerprint development and has shown great potential in visualizing fingerprints on metallic surfaces such as cartridge cases. Results indicate that this experimental arrangement can successfully develop aged latent fingerprints on metal surfaces, and we demonstrate its effectiveness compared with existing conventional fingerprint recovery methods. © 2016 American Academy of Forensic Sciences.

  12. Realist identification of group-level latent variables for perinatal social epidemiology theory building.

    Science.gov (United States)

    Eastwood, John Graeme; Jalaludin, Bin Badrudin; Kemp, Lynn Ann; Phung, Hai Ngoc

    2014-01-01

    We have previously reported in this journal on an ecological study of perinatal depressive symptoms in South Western Sydney. In that article, we briefly reported on a factor analysis that was utilized to identify empirical indicators for analysis. In this article, we report on the mixed method approach that was used to identify those latent variables. Social epidemiology has been slow to embrace a latent variable approach to the study of social, political, economic, and cultural structures and mechanisms, partly for philosophical reasons. Critical realist ontology and epistemology have been advocated as an appropriate methodological approach to both theory building and theory testing in the health sciences. We describe here an emergent mixed method approach that uses qualitative methods to identify latent constructs followed by factor analysis using empirical indicators chosen to measure identified qualitative codes. Comparative analysis of the findings is reported together with a limited description of realist approaches to abstract reasoning.

  13. 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...

  14. Latent constructs of the autobiographical memory questionnaire: a recollection-belief model of autobiographical experience.

    Science.gov (United States)

    Fitzgerald, Joseph M; Broadbridge, Carissa L

    2013-01-01

    Many researchers employ single-item scales of subjective experiences such as imagery and confidence to assess autobiographical memory. We tested the hypothesis that four latent constructs, recollection, belief, impact, and rehearsal, account for the variance in commonly used scales across four different types of autobiographical memory: earliest childhood memory, cue word memory of personal experience, highly vivid memory, and most stressful memory. Participants rated each memory on scales hypothesised to be indicators of one of four latent constructs. Multi-group confirmatory factor analyses and structural analyses confirmed the similarity of the latent constructs of recollection, belief, impact, and rehearsal, as well as the similarity of the structural relationships among those constructs across memory type. The observed pattern of mean differences between the varieties of autobiographical experiences was consistent with prior research and theory in the study of autobiographical memory.

  15. Latent human error analysis and efficient improvement strategies by fuzzy TOPSIS in aviation maintenance tasks.

    Science.gov (United States)

    Chiu, Ming-Chuan; Hsieh, Min-Chih

    2016-05-01

    The purposes of this study were to develop a latent human error analysis process, to explore the factors of latent human error in aviation maintenance tasks, and to provide an efficient improvement strategy for addressing those errors. First, we used HFACS and RCA to define the error factors related to aviation maintenance tasks. Fuzzy TOPSIS with four criteria was applied to evaluate the error factors. Results show that 1) adverse physiological states, 2) physical/mental limitations, and 3) coordination, communication, and planning are the factors related to airline maintenance tasks that could be addressed easily and efficiently. This research establishes a new analytic process for investigating latent human error and provides a strategy for analyzing human error using fuzzy TOPSIS. Our analysis process complements shortages in existing methodologies by incorporating improvement efficiency, and it enhances the depth and broadness of human error analysis methodology. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  16. Does attention-deficit/hyperactivity disorder have a dimensional latent structure? A taxometric analysis.

    Science.gov (United States)

    Marcus, David K; Barry, Tammy D

    2011-05-01

    An understanding of the latent structure of attention-deficit/hyperactivity disorder (ADHD) is essential for developing causal models of this disorder. Although some researchers have presumed that ADHD is dimensional and others have assumed that it is taxonic, there has been relatively little research directly examining the latent structure of ADHD. The authors conducted a set of taxometric analyses using data from the NICHD Study of Early Child Care and Youth Development (ns between 667 and 1,078). The results revealed a dimensional latent structure across a variety of different analyses and sets of indicators for inattention, hyperactivity/impulsivity, and ADHD. Furthermore, analyses of correlations with associated features indicated that dimensional models demonstrated stronger validity coefficients with these criterion measures than dichotomous models. These findings jibe with recent research on the genetic basis of ADHD and with contemporary models of ADHD.

  17. Acetone facilitated DNA sampling from electrical tapes improves DNA recovery and enables latent fingerprints development.

    Science.gov (United States)

    Feine, Ilan; Shpitzen, Moshe; Geller, Boris; Salmon, Eran; Peleg, Tsach; Roth, Jonathan; Gafny, Ron

    2017-07-01

    Electrical tapes (ETs) are a common component of improvised explosive devices (IEDs) used by terrorists or criminal organizations and represent a valuable forensic resource for DNA and latent fingerprints recovery. However, DNA recovery rates are typically low and usually below the minimal amount required for amplification. In addition, most DNA extraction methods are destructive and do not allow further latent fingerprints development. In the present study a cell culture based touch DNA model was used to demonstrate a two-step acetone-water DNA recovery protocol from ETs. This protocol involves only the adhesive side of the ET and increases DNA recovery rates by up to 70%. In addition, we demonstrated partially successful latent fingerprints development from the non-sticky side of the ETs. Taken together, this protocol maximizes the forensic examination of ETs and is recommended for routine casework processing. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. A Bayesian approach to estimate sensible and latent heat over vegetated land surface

    Directory of Open Access Journals (Sweden)

    C. van der Tol

    2009-06-01

    Full Text Available Sensible and latent heat fluxes are often calculated from bulk transfer equations combined with the energy balance. For spatial estimates of these fluxes, a combination of remotely sensed and standard meteorological data from weather stations is used. The success of this approach depends on the accuracy of the input data and on the accuracy of two variables in particular: aerodynamic and surface conductance. This paper presents a Bayesian approach to improve estimates of sensible and latent heat fluxes by using a priori estimates of aerodynamic and surface conductance alongside remote measurements of surface temperature. The method is validated for time series of half-hourly measurements in a fully grown maize field, a vineyard and a forest. It is shown that the Bayesian approach yields more accurate estimates of sensible and latent heat flux than traditional methods.

  19. 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.

  20. Effect of Acycloguanosine Treatment on Acute and Latent Herpes Simplex Infections in Mice

    Science.gov (United States)

    Field, Hugh J.; Bell, Susanne E.; Elion, Gertrude B.; Nash, Anthony A.; Wildy, Peter

    1979-01-01

    Systemic treatment of mice with the nucleoside analog 9-(2-hydroxyethoxymethyl)guanine (acycloguanosine [aciclovir]) was found to be highly effective against acute type 1 herpes simplex virus infection of the pinna. The drug ablated clinical signs and reduced virus replication both in tissue local to the inoculation site and within the nervous system. Provided that moderate-sized virus inocula were used, acycloguanosine treatment reduced or prevented the establishment of a latent infection in the dorsal root ganglia relating to the sensory nerve supply of the ear. However, although it aborted artificially produced infections in dorsal root ganglia, acycloguanosine was found not to be effective against the latent infection once established. This finding strongly indicated that latent herpes simplex virus in mice can exist in a nonreplicating form. PMID:464587

  1. Effect of acycloguanosine treatment of acute and latent herpes simplex infections in mice.

    Science.gov (United States)

    Field, H J; Bell, S E; Elion, G B; Nash, A A; Wildy, P

    1979-04-01

    Systemic treatment of mice with the nucleoside analog 9-(2-hydroxyethoxymethyl)guanine (acycloguanosine [aciclovir]) was found to be highly effective against acute type 1 herpes simplex virus infection of the pinna. The drug ablated clinical signs and reduced virus replication both in tissue local to the inoculation site and within the nervous system. Provided that moderate-sized virus inocula were used, acycloguanosine treatment reduced or prevented the establishment of a latent infection in the dorsal root ganglia relating to the sensory nerve supply of the ear. However, although it aborted artificially produced infections in dorsal root ganglia, acycloguanosine was found not to be effective against the latent infection once established. This finding strongly indicated that latent herpes simplex virus in mice can exist in a nonreplicating form.

  2. Do gender and directness of trauma exposure moderate PTSD's latent structure?

    Science.gov (United States)

    Frankfurt, Sheila B; Armour, Cherie; Contractor, Ateka A; Elhai, Jon D

    2016-11-30

    The PTSD diagnosis and latent structure were substantially revised in the transition from DSM-IV to DSM-5. However, three alternative models (i.e., anhedonia model, externalizing behavior model, and hybrid model) of PTSD fit the DSM-5 symptom criteria better than the DSM-5 factor model. Thus, the psychometric performance of the DSM-5 and alternative models' PTSD factor structure needs to be critically evaluated. The current study examined whether gender or trauma directness (i.e., direct or indirect trauma exposure) moderates the PTSD latent structure when using the DSM-5 or alternative models. Model performance was evaluated with measurement invariance testing procedures on a large undergraduate sample (n=455). Gender and trauma directness moderated the DSM-5 PTSD and externalizing behavior model and did not moderate the anhedonia and hybrid models' latent structure. Clinical implications and directions for future research are discussed. Published by Elsevier Ireland Ltd.

  3. Immunization against Genital Herpes with a Vaccine Virus That has Defects in Productive and Latent Infection

    Science.gov (United States)

    da Costa, Xavier J.; Jones, Cheryl A.; Knipe, David M.

    1999-06-01

    An effective vaccine for genital herpes has been difficult to achieve because of the limited efficacy of subunit vaccines and the safety concerns about live viruses. As an alternative approach, mutant herpes simplex virus strains that are replication-defective can induce protective immunity. To increase the level of safety and to prove that replication was not needed for immunization, we constructed a mutant herpes simplex virus 2 strain containing two deletion mutations, each of which eliminated viral replication. The double-mutant virus induces protective immunity that can reduce acute viral shedding and latent infection in a mouse genital model, but importantly, the double-mutant virus shows a phenotypic defect in latent infection. This herpes vaccine strain, which is immunogenic but has defects in both productive and latent infection, provides a paradigm for the design of vaccines and vaccine vectors for other sexually transmitted diseases, such as AIDS.

  4. Archivo del Duelo

    OpenAIRE

    Ferrera, Tamara

    2010-01-01

    Photos taken from the Archive of Mourning following the March 11 terrorist attacks El Archivo del Duelo. Creación de un archivo etnográfico de los Atentados del 11 de marzo en Madrid. Ministerio de Educación y Ciencia HUM2005-03490.

  5. Displasias del seno

    Directory of Open Access Journals (Sweden)

    Ernesto Andrade Valderrama

    1971-04-01

    Full Text Available En general, las Displasias no se presentan antes de la iniciación del estímulo Gonadal y tienden a desaparecer con el climaterio. Se definen entonces como las afecciones benignas del Seno, de origen endocrino.

  6. A comparative study of matrix metalloproteinase and aggrecanase mediated release of latent cytokines at arthritic joints.

    Science.gov (United States)

    Mullen, Lisa; Adams, Gill; Foster, Julie; Vessillier, Sandrine; Köster, Mario; Hauser, Hansjörg; Layward, Lorna; Gould, David; Chernajovsky, Yuti

    2014-09-01

    Latent cytokines are engineered by fusing the latency associated peptide (LAP) derived from transforming growth factor-β (TGF-β) with the therapeutic cytokine, in this case interferon-β (IFN-β), via an inflammation-specific matrix metalloproteinase (MMP) cleavage site. To demonstrate latency and specific delivery in vivo and to compare therapeutic efficacy of aggrecanase-mediated release of latent IFN-β in arthritic joints to the original MMP-specific release. Recombinant fusion proteins with MMP, aggrecanase or devoid of cleavage site were expressed in CHO cells, purified and characterised in vitro by Western blotting and anti-viral protection assays. Therapeutic efficacy and half-life were assessed in vivo using the mouse collagen-induced arthritis model (CIA) of rheumatoid arthritis and a model of acute paw inflammation, respectively. Transgenic mice with an IFN-regulated luciferase gene were used to assess latency in vivo and targeted delivery to sites of disease. Efficient localised delivery of IFN-β to inflamed paws, with low levels of systemic delivery, was demonstrated in transgenic mice using latent IFN-β. Engineering of latent IFN-β with an aggrecanase-sensitive cleavage site resulted in efficient cleavage by ADAMTS-4, ADAMTS-5 and synovial fluid from arthritic patients, with an extended half-life similar to the MMP-specific molecule and greater therapeutic efficacy in the CIA model. Latent cytokines require cleavage in vivo for therapeutic efficacy, and they are delivered in a dose dependent fashion only to arthritic joints. The aggrecanase-specific cleavage site is a viable alternative to the MMP cleavage site for the targeting of latent cytokines to arthritic joints. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Rapid visualization of latent fingermarks using gold seed-mediated enhancement

    Directory of Open Access Journals (Sweden)

    Chia-Hao Su

    2016-11-01

    Full Text Available Abstract Background Fingermarks are one of the most important and useful forms of physical evidence in forensic investigations. However, latent fingermarks are not directly visible, but can be visualized due to the presence of other residues (such as inorganic salts, proteins, polypeptides, enzymes and human metabolites which can be detected or recognized through various strategies. Convenient and rapid techniques are still needed to provide obvious contrast between the background and the fingermark ridges and to then visualize latent fingermark with a high degree of selectivity and sensitivity. Results In this work, lysozyme-binding aptamer-conjugated Au nanoparticles (NPs are used to recognize and target lysozyme in the fingermark ridges, and Au+-complex solution is used as a growth agent to reduce Au+ from Au+ to Au0 on the surface of the Au NPs. Distinct fingermark patterns were visualized on a range of professional forensic within 3 min; the resulting images could be observed by the naked eye without background interference. The entire processes from fingermark collection to visualization only entails two steps and can be completed in less than 10 min. The proposed method provides cost and time savings over current fingermark visualization methods. Conclusions We report a simple, inexpensive, and fast method for the rapid visualization of latent fingermarks on the non-porous substrates using Au seed-mediated enhancement. Au seed-mediated enhancement is used to achieve the rapid visualization of latent fingermarks on non-porous substrates by the naked eye without the use of expensive or sophisticated instruments. The proposed approach offers faster detection and visualization of latent fingermarks than existing methods. The proposed method is expected to increase detection efficiency for latent fingermarks and reduce time requirements and costs for forensic investigations.

  8. Influence of WFIKKN1 on BMP1-mediated activation of latent myostatin.

    Science.gov (United States)

    Szláma, György; Vásárhelyi, Viktor; Trexler, Mária; Patthy, László

    2016-12-01

    The NTR domain of WFIKKN1 protein has been shown to have significant affinity for the prodomain regions of promyostatin and latent myostatin but the biological significance of these interactions remained unclear. In view of its role as a myostatin antagonist, we tested the assumption that WFIKKN1 inhibits the release of myostatin from promyostatin and/or latent myostatin. WFIKKN1 was found to have no effect on processing of promyostatin by furin, the rate of cleavage of latent myostatin by BMP1, however, was significantly enhanced in the presence of WFIKKN1 and this enhancer activity was superstimulated by heparin. Unexpectedly, WFIKKN1 was also cleaved by BMP1 and our studies have shown that the KKN1 fragment generated by BMP1-cleavage of WFIKKN1 contributes most significantly to the observed enhancer activity. Analysis of a pro-TGF-β -based homology model of homodimeric latent myostatin revealed that the BMP1-cleavage sites are buried and not readily accessible to BMP1. In view of this observation, the most plausible explanation for the BMP1-enhancer activity of the KKN1 fragment is that it shifts a conformational equilibrium of latent myostatin from the closed circular structure of the homodimer to a more open form, making the cleavage sites more accessible to BMP1. On the other hand, the observation that the enhancer activity of KKN1 is superstimulated in the presence of heparin is explained by the fact KKN1, latent myostatin, and BMP1 have affinity for heparin and these interactions with heparin increase the local concentrations of the reactants thereby facilitating the action of BMP1. Furin: EC 3.4.21.75; BMP1, bone morphogentic protein 1 or procollagen C-endopeptidase: EC 3.4.24.19. © 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

  9. Accounting for standard errors of vision-specific latent trait in regression models.

    Science.gov (United States)

    Wong, Wan Ling; Li, Xiang; Li, Jialiang; Wong, Tien Yin; Cheng, Ching-Yu; Lamoureux, Ecosse L

    2014-07-11

    To demonstrate the effectiveness of Hierarchical Bayesian (HB) approach in a modeling framework for association effects that accounts for SEs of vision-specific latent traits assessed using Rasch analysis. A systematic literature review was conducted in four major ophthalmic journals to evaluate Rasch analysis performed on vision-specific instruments. The HB approach was used to synthesize the Rasch model and multiple linear regression model for the assessment of the association effects related to vision-specific latent traits. The effectiveness of this novel HB one-stage "joint-analysis" approach allows all model parameters to be estimated simultaneously and was compared with the frequently used two-stage "separate-analysis" approach in our simulation study (Rasch analysis followed by traditional statistical analyses without adjustment for SE of latent trait). Sixty-six reviewed articles performed evaluation and validation of vision-specific instruments using Rasch analysis, and 86.4% (n = 57) performed further statistical analyses on the Rasch-scaled data using traditional statistical methods; none took into consideration SEs of the estimated Rasch-scaled scores. The two models on real data differed for effect size estimations and the identification of "independent risk factors." Simulation results showed that our proposed HB one-stage "joint-analysis" approach produces greater accuracy (average of 5-fold decrease in bias) with comparable power and precision in estimation of associations when compared with the frequently used two-stage "separate-analysis" procedure despite accounting for greater uncertainty due to the latent trait. Patient-reported data, using Rasch analysis techniques, do not take into account the SE of latent trait in association analyses. The HB one-stage "joint-analysis" is a better approach, producing accurate effect size estimations and information about the independent association of exposure variables with vision-specific latent traits

  10. 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.

  11. 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.

  12. Bayesian leave-one-out cross-validation approximations for Gaussian latent variable models

    DEFF Research Database (Denmark)

    Vehtari, Aki; Mononen, Tommi; Tolvanen, Ville

    2016-01-01

    The future predictive performance of a Bayesian model can be estimated using Bayesian cross-validation. In this article, we consider Gaussian latent variable models where the integration over the latent values is approximated using the Laplace method or expectation propagation (EP). We study...... the properties of several Bayesian leave-one-out (LOO) cross-validation approximations that in most cases can be computed with a small additional cost after forming the posterior approximation given the full data. Our main objective is to assess the accuracy of the approximative LOO cross-validation estimators...

  13. 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.

  14. On the Integrity of Online Testing for Introductory Statistics Courses: A Latent Variable Approach

    Directory of Open Access Journals (Sweden)

    Alan Fask

    2015-04-01

    Full Text Available There has been a remarkable growth in distance learning courses in higher education. Despite indications that distance learning courses are more vulnerable to cheating behavior than traditional courses, there has been little research studying whether online exams facilitate a relatively greater level of cheating. This article examines this issue by developing an approach using a latent variable to measure student cheating. This latent variable is linked to both known student mastery related variables and variables unrelated to student mastery. Grade scores from a proctored final exam and an unproctored final exam are used to test for increased cheating behavior in the unproctored exam

  15. Space-time latent component modeling of geo-referenced health data.

    Science.gov (United States)

    Lawson, Andrew B; Song, Hae-Ryoung; Cai, Bo; Hossain, Md Monir; Huang, Kun

    2010-08-30

    Latent structure models have been proposed in many applications. For space-time health data it is often important to be able to find the underlying trends in time, which are supported by subsets of small areas. Latent structure modeling is one such approach to this analysis. This paper presents a mixture-based approach that can be applied to component selection. The analysis of a Georgia ambulatory asthma county-level data set is presented and a simulation-based evaluation is made. Copyright (c) 2010 John Wiley & Sons, Ltd.

  16. Scintigraphy in detection of latent inflammatory foci in patients with pseudarthroses

    International Nuclear Information System (INIS)

    Woy-Wojciechowski, J.; Zawadzinski, S.

    1982-01-01

    Treatment of infected pseudarthroses is one of the most difficult problems in orthopaedic surgery. Presence of latent inflammatory foci may be a serious complication after bone grafting. In 14 cases of pseudarthroses radioisotope scanning demonstrated in 5 cases presence of additional latent inflammatory foci which gave cues as to the type and extent of surgical treatment. In all these cases evaluation of the local condition by X-ray examination was insufficient. Isotope scanning was useful for a radical surgical treatment making possible complete eradication of the inflammation and reducing thus the risk of inflammation recurrence at the site of the operation performed for achieving bone union or for implanting bone graft. (author)

  17. STRUCTURE RELATION OF VIOLENCE AND PERSONALITY LATENT DIMENSIONS OF PREADOLESCENT BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Miroljub Ivanović

    2012-09-01

    Full Text Available The aim of this research was to define structure relations of latent dimension violence among peers structure, characteristics and parent’s educational attitudes. In this research participated 134 basketball players (mini-jam, younger pioneers and pioneers. The research was conducted using the PRONA questionnaire for peers violence evaluation (Maksimovic and collaborators, 2008. Analysing the main components space of peers’ violence, three main components have been determined as dangerous behaviour exposure, announced victim and physiological violence. Mutual relation of these latent personality characteristics examinees dimensions and educational attitudes of their parents has been determined using the Pirson’s correlation coefficien.

  18. Ultra high temperature latent heat energy storage and thermophotovoltaic energy conversion

    OpenAIRE

    Datas Medina, Alejandro; Ramos Cabal, Alba; Martí Vega, Antonio; Cañizo Nadal, Carlos del; Luque López, Antonio

    2016-01-01

    A conceptual energy storage system design that utilizes ultra high temperature phase change materials is presented. In this system, the energy is stored in the form of latent heat and converted to electricity upon demand by TPV (thermophotovoltaic) cells. Silicon is considered in this study as PCM (phase change material) due to its extremely high latent heat (1800 J/g or 500 Wh/kg), melting point (1410 C), thermal conductivity (~25 W/mK), low cost (less than $2/kg or $4/kWh) and a...

  19. La crisi del diritto del lavoro

    Directory of Open Access Journals (Sweden)

    Alessandro Garilli

    2012-01-01

    Full Text Available Riassunto - L’Autore ripercorre in chiave critica l’evoluzione delle politiche legislative in materia di lavoro, alla luce dell’attuale fase di crisi economico finanziaria. Nell’esaminare i principali interventi normativi attuati da inizio secolo, l’Autore mette in evidenza le scelte di metodo e gli elementi di continuità che accomunano i vari provvedimenti, individuandoli nell’affannosa ricerca del punto di equilibrio tra flessibilità e garantismo. La riflessione si chiude con alcuni interrogativi sulle ultime linee di riforma del mercato del lavoro e con l’auspicio che, anche al cospetto delle imprescindibili ragioni dell’economia, il diritto del lavoro possa continuare a svolgere il proprio tradizionale ruolo di disciplina di tutela della persona.   Abstract - The author analyzes, with a critically oriented approach, the development of the employment law, in the light of the current economic and financial crisis. In examining the main regulatory measures implemented since the beginning of the century, the author highlights the methodological choices and the elements of continuity that unite the various measures, focusing them in a hard research of a point of balance between flexibility and security. The discussion concludes with some questions about the last lines of the reform of the labor market and with the hope that, even in the face of compelling reasons of economy, labor law can continue to play its traditional role of governing the protection of person.

  20. OBJETIVO DEL DESARROLLO DEL MILENIO 7

    Directory of Open Access Journals (Sweden)

    Margarita M. Pérez O.

    2013-10-01

    Full Text Available Los Objetivos de Desarrollo del Milenio, también conocidos como los Objetivos del Milenio, constituyeron las metas finales que aprobaron los dirigentes mundiales, 189 jefes de estado y de gobierno en la Cumbre del Milenio de las Naciones Unidas celebrada en Nueva York en el año 2000, en la cual los Estados miembros de la organización reafirmaron su compromiso de luchar por un mundo en el que el desarrollo sostenible y la eliminación de la pobreza tuvieran máxima prioridad1 . En la cumbre se definió la Declaración del Milenio, la cual detalla los objetivos, principios, valores, metas y acciones para erradicar la pobreza Mundial hacia el año 2015, todos ellos ratificados con alto interés y acción estratégica de carácter global, como marco para la medición de los progresos en materia de desarrollo.

  1. Elementos del sistema electoral del Congreso Mexicano

    Directory of Open Access Journals (Sweden)

    Aldo Medina García

    2013-08-01

    Full Text Available El presente artículo es un estudio de los componentes del sistema electoral, diseñado por el legislador mexicano para integrar al parlamento federal. Estudio desarrollado a sabiendas de la importancia que reviste el sistema electoral como un medio que permite a los ciudadanos convertir su voto expresado en las urnas en escaños a favor de determinado candidato o partido. En dicho análisis tomamos en cuenta la evolución constitucional del sistema electoral mexicano, la participación de las fuerzas minoritarias en la integración del Senado y de la Cámara de Diputados, la división que se hace del territorio en circunscripciones electorales, la barrera electoral que se fija a los partidos políticos para acceder a la representación en el Parlamento, la fórmula de asignación que se aplica a la votación obtenida, para finalmente concluir que el sistema electoral mexicano es esencialmente mayoritario aun cuando se vista de proporcional.

  2. 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…

  3. Prevalence Estimation and Validation of New Instruments in Psychiatric Research: An Application of Latent Class Analysis and Sensitivity Analysis

    Science.gov (United States)

    Pence, Brian Wells; Miller, William C.; Gaynes, Bradley N.

    2009-01-01

    Prevalence and validation studies rely on imperfect reference standard (RS) diagnostic instruments that can bias prevalence and test characteristic estimates. The authors illustrate 2 methods to account for RS misclassification. Latent class analysis (LCA) combines information from multiple imperfect measures of an unmeasurable latent condition to…

  4. A Comparison of Approaches for the Analysis of Interaction Effects between Latent Variables Using Partial Least Squares Path Modeling

    Science.gov (United States)

    Henseler, Jorg; Chin, Wynne W.

    2010-01-01

    In social and business sciences, the importance of the analysis of interaction effects between manifest as well as latent variables steadily increases. Researchers using partial least squares (PLS) to analyze interaction effects between latent variables need an overview of the available approaches as well as their suitability. This article…

  5. Mixture Item Response Theory-MIMIC Model: Simultaneous Estimation of Differential Item Functioning for Manifest Groups and Latent Classes

    Science.gov (United States)

    Bilir, Mustafa Kuzey

    2009-01-01

    This study uses a new psychometric model (mixture item response theory-MIMIC model) that simultaneously estimates differential item functioning (DIF) across manifest groups and latent classes. Current DIF detection methods investigate DIF from only one side, either across manifest groups (e.g., gender, ethnicity, etc.), or across latent classes…

  6. Bartonelosis aguda en niños: Estudio de 32 casos en el Instituto Especializado de Salud del Niño y el Hospital Nacional Cayetano Heredia (Período 1993-2003.

    Directory of Open Access Journals (Sweden)

    Judith Patricia BREÑA CHÁVEZ

    2006-07-01

    Full Text Available Objetivos: Determinar las características epidemiológicas, clínicas, datos de laboratorio y tratamiento de la Bartonelosis aguda en niños. Materiales y métodos: Se revisaron las historias clínicas de 32 niños con Bartonelosis aguda, internados en el Hospital Nacional Cayetano Heredia y en el Instituto Especializado de Salud del Niño entre 1993 y 2003. Resultados: La edad promedio fue 9,8 años, 72% fueron varones, los lugares de exposición probable fueron principalmente las zonas endémicas de los valles interandinos de Perú, pero hubieron pacientes procedentes de zonas no endémicas de la selva alta; fueron nativos de éstas zonas el 72%. Los síntomas principales fueron fiebre (97%, hiporexia (91%, síntomas gastrointestinales (66% y malestar general (53%; los signos principales fueron palidez (97%, hepatomegalia (78%, taquicardia (75% y linfadenomegalia (72%. El promedio de hematocrito fue 18,8 %, 63% cursaron con anemia severa, leucocitosis 63%, hiperbilirrubinemia a predominio indirecto 45% de casos e hipoalbuminemia el 68%. Las complicaciones fueron frecuentes (78%, siendo las infecciosas 25%, no infecciosas 22%, infecciosas y no infecciosas 31%. De las infecciosas destacan las respiratorias (25%, fiebre tifoidea / salmonelosis (19%, un caso de endocarditis infecciosa y otro de probable púrpura fulminans. De las complicaciones no infecciosas desatacan las complicaciones cardiovasculares (34% y la neurobartonelosis (34%; hubo un caso de anemia hemolítica autoinmune. El 72% recibió transfusiones sanguíneas; el 97% recibió antibiótico, utilizando cloranfenicol (56% y ciprofloxacino (34%. La letalidad fue de 6%. Conclusiones: La Bartonelosis aguda en esta serie tuvo gran morbilidad, siendo frecuentes las complicaciones cardiovasculares, neurológicas y respiratorias. (Rev Med Hered 2006;17:122-131.

  7. Castillo del Real. Olocau

    OpenAIRE

    AUÑÓN VALLEJO, JONATAN

    2012-01-01

    El objetivo que se quiere alcanzar con este proyecto es el de realizar un estudio lo más cercano posible del Catillo del Real, de manera que se pueda conocer su origen, su evolución a lo largo de la historia, así como las diferentes técnicas y sistemas constructivos utilizados en su construcción. Auñón Vallejo, J. (2011). Castillo del Real. Olocau. http://hdl.handle.net/10251/14244. Archivo delegado

  8. La Representabilidad del Genocidio

    OpenAIRE

    Cardona González, Lorena

    2012-01-01

    El presente artículo intenta hacer una aproximación histórica y analítica al fenómeno del Genocidio, sus implicaciones sociales y culturales que dieron como resultado la reformulación analítica y conceptual de hechos que hasta entonces superaban el conocimiento y la moral humana. De este modo, se hace un trayecto histórico de la paulatina aparición del asesinato masivo como practica de Estado, enmarcado en las experiencias del genocidio armenio y el alemán. A su vez, se hace una mirada sobre ...

  9. Significado presente del CSIC

    OpenAIRE

    Garrido Gallardo, Miguel Angel

    2000-01-01

    Not available

    Este artículo, elaborado en 1999, ofrece una panorámica de la realidad del Consejo Superior de Investigaciones Científicas en la actualidad. Repasa su organización, su volumen de publicaciones, sus indicadores de productividad, su capacidad de obtener recursos y, en suma, su lugar en el conjunto del sistema español de Ciencia y Tecnología, considerado en sí mismo y en relación con la Universidad. Como conclusión del repaso de datos, se afirma que, aunque la fó...

  10. Tratamiento del pie equino

    OpenAIRE

    Robles, Fernanda

    2012-01-01

    El pie equino varo es una patología frecuente en los pacientes con Encefalopatía crónica no evolutiva (ECNE).Se observó que existe una mayor frecuencia en el sexo masculino. Se realizó un estudio descriptivo, comparativo y secundario, durante el periodo de septiembre del 2006 a septiembre del 2011, con un total de 125 pacientes con Ecne, de los cuales se encontraron 101 con pie equino varo congénito. Objetivo: observar los resultados obtenidos en la rehabilitación del pie equino, en niños de ...

  11. Del Pasadismo al Futurismo

    OpenAIRE

    Agudo-Martínez, M. J.

    2003-01-01

    Uno de los habituales prejuicios a la hora de abordar el análisis del movimiento futurista, al igual que sucede con el constructivismo, es la consideración del contexto político en el que se desarrollaron ambas vanguardias. Sin embargo, y dejando a un lado un enfoque del arte con finalidad política de signo diverso, habría que insistir en el hecho de que posiblemente sean tanto el futurismo italiano como el constructivismo ruso, los movimientos que con mayor entusiasmo se manifestaron, en un ...

  12. Análisis del comportamiento del consumidor: medición cuantitativa del servicio en estudiantes de administración de una universidad acreditada en Barranquilla

    Directory of Open Access Journals (Sweden)

    Gustavo R. Henríquez Fuentes

    2016-07-01

    Full Text Available El presente artículo es resultado de una investigación que se realizó en una Universidad acreditada de la ciudad de Barranquilla, con una muestra de aproximadamente 90 estudiantes, sobre una población total de 1143 estudiantes del programa de Administración de Empresas. El objetivo principal consistió en revelar las variables latentes que permitan conocer el comportamiento del consumidor (estudiantes y el desarrollo de un modelo para la medición del servicio. Se presentan resultados empíricos, a partir del método cuantitativo y técnicas de estadística inferencial como el análisis factorial y clusterización. Los resultados permitieron conocer a través de las dimensiones de la escala Servqual, lo que demandan los estudiantes, así como reconocer dos grupos. Se propone, además, el rediseño de la encuesta SERVQUAL, adaptándola a una tipo Likert, así como correr los datos en procesadores estadísticos como Statgraphics y SSPS para realizar el análisis de la información. Abstract This research was conducted at an accredited University in the city of Barranquilla, from a sample of about 90 students, out of a total population of 1143 students of their Business Administration program. This article is the result of an investigation, presenting empirical results through the use of a quantitative technique method and inferential statistics such as factor analysis and clustering. The main objective is to reveal the latent variables that show consumer behavior on students and the development of a model for service measurement. It is proposed for application on the consumer psychology when being served, the redesign of the SERVQUAL survey, through a survey Likert, running statistical data processors like Statgraphics and SSPS for the analysis of information. The results allowed to know through the dimensions of the Servqual scale, what students require , thus recognizing two groups.

  13. Micro-macro multilevel latent class models with multiple discrete individual-level variables

    NARCIS (Netherlands)

    Bennink, M.; Croon, M.A.; Kroon, B.; Vermunt, J.K.

    2016-01-01

    An existing micro-macro method for a single individual-level variable is extended to the multivariate situation by presenting two multilevel latent class models in which multiple discrete individual-level variables are used to explain a group-level outcome. As in the univariate case, the

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

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2013-01-01

    to prioritize safety issues and to devise efficient preventive measures. Method: The current study focused on cyclist–motorist crashes that occurred in Denmark during the period between 2007 and 2011. To uncover crash patterns, the current analysis applied latent class clustering, an unsupervised probabilistic...

  15. 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

  16. 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…

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

    NARCIS (Netherlands)

    Tang, Jianjun; Folmer, Henk

    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

  19. The Latent Curve ARMA (P, Q) Panel Model: Longitudinal Data Analysis in Educational Research and Evaluation

    Science.gov (United States)

    Sivo, Stephen; Fan, Xitao

    2008-01-01

    Autocorrelated residuals in longitudinal data are widely reported as common to longitudinal data. Yet few, if any, researchers modeling growth processes evaluate a priori whether their data have this feature. Sivo, Fan, and Witta (2005) found that not modeling autocorrelated residuals present in longitudinal data severely biases latent curve…

  20. 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...

  1. An Evaluation of the Materialization of the Latent Functions of Education According to Student Perceptions

    Science.gov (United States)

    Aydogan, Ismail

    2009-01-01

    The problem of the study centers on determining the level to which such latent functions of education are materialized for university graduates. The study was conducted on a total of 231 graduate students undertaking a thesis or non-thesis Master's degree at Erciyes University School of Social Sciences. Data was collected by using a questionnaire…

  2. Clinical and Diagnostic Features of Bronchial Asthma in Children on the Background of Latent Food Allergy

    Directory of Open Access Journals (Sweden)

    V.M. Levytskyi

    2015-09-01

    Full Text Available Based on clinical and paraclinical examination of 112 children with bronchial asthma, there were studied the features of its course against the background of food allergy. It was found that only a set of clinical and paraclinical signs is the most important for the diagnosis of bronchial asthma in children on the background of latent food allergy.

  3. Evaluation of Validity and Reliability for Hierarchical Scales Using Latent Variable Modeling

    Science.gov (United States)

    Raykov, Tenko; Marcoulides, George A.

    2012-01-01

    A latent variable modeling method is outlined, which accomplishes estimation of criterion validity and reliability for a multicomponent measuring instrument with hierarchical structure. The approach provides point and interval estimates for the scale criterion validity and reliability coefficients, and can also be used for testing composite or…

  4. 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…

  5. Targeting the latent cytomegalovirus reservoir with an antiviral fusion toxin protein

    DEFF Research Database (Denmark)

    Krishna, B A; Spiess, K; Poole, E L

    2017-01-01

    Reactivation of human cytomegalovirus (HCMV) in transplant recipients can cause life-threatening disease. Consequently, for transplant recipients, killing latently infected cells could have far-reaching clinical benefits. In vivo, myeloid cells and their progenitors are an important site of HCMV ...

  6. Occurence of internet addiction in a general population sample: A latent class analysis

    NARCIS (Netherlands)

    Rumpf, H.J.; Vermulst, A.A.; Bischof, A.; Kastirke, N.; Gürtler, D.; Bischof, G.; Meerkerk, G.J.; John, U.; Meyer, C.

    2014-01-01

    Background: Prevalence studies of Internet addiction in the general population are rare. In addition, a lack of approved criteria hampers estimation of its occurrence. Aims: This study conducted a latent class analysis (LCA) in a large general population sample to estimate prevalence. Methods: A

  7. Computational Tools for Probing Interactions in Multiple Linear Regression, Multilevel Modeling, and Latent Curve Analysis

    Science.gov (United States)

    Preacher, Kristopher J.; Curran, Patrick J.; Bauer, Daniel J.

    2006-01-01

    Simple slopes, regions of significance, and confidence bands are commonly used to evaluate interactions in multiple linear regression (MLR) models, and the use of these techniques has recently been extended to multilevel or hierarchical linear modeling (HLM) and latent curve analysis (LCA). However, conducting these tests and plotting the…

  8. The latent structure of oppositional defiant disorder in children and adults.

    Science.gov (United States)

    Barry, Tammy D; Marcus, David K; Barry, Christopher T; Coccaro, Emil F

    2013-12-01

    An understanding of the latent structure of oppositional defiant disorder (ODD) is essential for better developing causal models, improving diagnostic and assessment procedures, and enhancing treatments for the disorder. Although much research has focused on ODD-including recent studies informing the diagnostic criteria for DSM-5-research examining the latent structure of ODD is sparse, and no known study has specifically undertaken a taxometric analysis to address the issue of whether ODD is a categorical or dimensional construct. To address this gap, the authors conducted two separate studies using a set of taxometric analyses with data from the NICHD Study of Early Child Care and Youth Development (child study; n = 969) and with data from a large mixed sample of adults, which included participants reporting psychiatric difficulties as well as healthy controls (adult study; n = 600). The results of a variety of non-redundant analyses across both studies revealed a dimensional latent structure for ODD symptoms among both children and adults. These findings are consistent with previous studies that have examined latent structure of related constructs (e.g., aggression, antisocial behavior) as well as studies that have examined the dimensional versus categorical structure of ODD using methods other than taxometric analysis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Correcting Model Fit Criteria for Small Sample Latent Growth Models with Incomplete Data

    Science.gov (United States)

    McNeish, Daniel; Harring, Jeffrey R.

    2017-01-01

    To date, small sample problems with latent growth models (LGMs) have not received the amount of attention in the literature as related mixed-effect models (MEMs). Although many models can be interchangeably framed as a LGM or a MEM, LGMs uniquely provide criteria to assess global data-model fit. However, previous studies have demonstrated poor…

  10. 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.…

  11. Time of day-dependent latent inhibition of conditioned taste aversions in rats

    Czech Academy of Sciences Publication Activity Database

    Manrique, T.; Molero, A.; Ballesteros, M. A.; Morón, I.; Gallo, M.; Fenton, André Antonio

    2004-01-01

    Roč. 82, č. 2 (2004), s. 77-80 ISSN 1074-7427 Grant - others:CICYT(ES) BSO2002-01215 Institutional research plan: CEZ:AV0Z5011922 Keywords : condition taste aversion * latent inhibition * temporal context Subject RIV: FH - Neurology Impact factor: 4.443, year: 2004

  12. Elimination of hop latent viroid upon developmental activation of pollen nucleases

    Czech Academy of Sciences Publication Activity Database

    Matoušek, Jaroslav; Orctová, Lidmila; Škopek, Josef; Pešina, Karel; Steger, G.

    2008-01-01

    Roč. 389, č. 7 (2008), s. 905-918 ISSN 1431-6730 R&D Projects: GA AV ČR(CZ) 1QS500510558; GA ČR GA521/06/1149 Institutional research plan: CEZ:AV0Z50510513 Keywords : hop latent viroid * elimination Subject RIV: EE - Microbiology, Virology Impact factor: 3.035, year: 2008

  13. Latent Heat Flow in Light Weight Roofs and its Influence on the Thermal Performance

    DEFF Research Database (Denmark)

    Rode, Carsten; Rudbeck, Claus Christian

    1998-01-01

    Under certain conditions, migration of small amounts of moisture in the envelope of buildings can cause heat flow through permeable thermal insulation materials due to the conversion of latent heat when moisture evaporates from a warm surface, diffuses through the insulation, and condenses...

  14. Management of latent Mycobacterium tuberculosis infection: WHO guidelines for low tuberculosis burden countries

    NARCIS (Netherlands)

    Getahun, Haileyesus; Matteelli, Alberto; Abubakar, Ibrahim; Aziz, Mohamed Abdel; Baddeley, Annabel; Barreira, Draurio; den Boon, Saskia; Borroto Gutierrez, Susana Marta; Bruchfeld, Judith; Burhan, Erlina; Cavalcante, Solange; Cedillos, Rolando; Chaisson, Richard; Chee, Cynthia Bin-Eng; Chesire, Lucy; Corbett, Elizabeth; Dara, Masoud; Denholm, Justin; de Vries, Gerard; Falzon, Dennis; Ford, Nathan; Gale-Rowe, Margaret; Gilpin, Chris; Girardi, Enrico; Go, Un-Yeong; Govindasamy, Darshini; D Grant, Alison; Grzemska, Malgorzata; Harris, Ross; Horsburgh, C. Robert; Ismayilov, Asker; Jaramillo, Ernesto; Kik, Sandra; Kranzer, Katharina; Lienhardt, Christian; LoBue, Philip; Lönnroth, Knut; Marks, Guy; Menzies, Dick; Migliori, Giovanni Battista; Mosca, Davide; Mukadi, Ya Diul; Mwinga, Alwyn; Nelson, Lisa; Nishikiori, Nobuyuki; Oordt-Speets, Anouk; Rangaka, Molebogeng Xheedha; Reis, Andreas; Rotz, Lisa; Sandgren, Andreas; Sañé Schepisi, Monica; Schünemann, Holger J.; Sharma, Surender Kumar; Sotgiu, Giovanni; Stagg, Helen R.; Sterling, Timothy R.; Tayeb, Tamara; Uplekar, Mukund; van der Werf, Marieke J.; Vandevelde, Wim; van Kessel, Femke; van't Hoog, Anna; Varma, Jay K.; Vezhnina, Natalia; Voniatis, Constantia; Vonk Noordegraaf-Schouten, Marije; Weil, Diana; Weyer, Karin; Wilkinson, Robert John; Yoshiyama, Takashi; Zellweger, Jean Pierre; Raviglione, Mario

    2015-01-01

    Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health

  15. Realizing the Latent Potential in the Part-Time Student Workforce

    Science.gov (United States)

    Evans, Carl; Richardson, Mark

    2016-01-01

    The purpose of this article is to challenge employers to make the best use of the latent potential of their part-time student workforce and to retain this talent postgraduation. The authors report research which shows that increasing numbers of university students are working part-time alongside their degree studies, while at the same time…

  16. 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…

  17. 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…

  18. Identifying person-fit latent classes, and explanation of categorical and continuous person misfit

    NARCIS (Netherlands)

    Conijn, J.M.; Sijtsma, K.; Emons, W.H.M.

    2016-01-01

    Latent class (LC) cluster analysis of a set of subscale lz person-fit statistics was proposed to explain person misfit on multiscale measures. The proposed explanatory LC person-fit analysis was used to analyze data of students (N = 91,648) on the nine-subscale School Attitude Questionnaire Internet

  19. 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…

  20. The effect of DNA recovery on the subsequent quality of latent fingermarks.

    Science.gov (United States)

    Fieldhouse, Sarah; Oravcova, Eliska; Walton-Williams, Laura

    2016-10-01

    The recovery of DNA and fingermark evidence from the same site can be problematic on account of potential contamination from fingermark visualisation techniques, and/or the destructive capability of the DNA recovery method. Forensic investigators are therefore often required to choose which evidence type to recover, or to recover both evidence types from different sites. Research typically documents the effects of fingermark visualisation techniques on the subsequent recovery of DNA, whereas this research has investigated the effects of DNA recovery on the quality of subsequently recovered latent fingermarks. Eccrine rich, sebaceous rich, and 'normal' latent fingermarks were deposited onto five substrates: glass; aluminium; textured plastic; varnished wood; photocopier paper and aged from 4h to 4 weeks. Approximately half of the control fingermarks were developed without DNA recovery on all substrates. The remaining samples were subjected to one of five DNA recovery methods prior to fingermark development. Pre and post DNA recovered fingermarks were graded for quality, and AFIS correlations scores were obtained and analysed for statistically significant differences using Wilcoxon Signed Rank tests and Friedman tests. All of the DNA recovery methods reduced the quality of latent fingermarks on glass surfaces. Flocked swabs and gel lifts were the least destructive DNA recovery methods on the remaining surfaces, except for aluminium sheet metal. The quality of latent fingermarks deposited onto glossed wood and textured plastic and paper were less affected by dry swabbing. Wet swabbing and tape lifting were very damaging methods of DNA recovery. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. RMT Assessments of the Market Latent Information Embedded in the Stocks' Raw, Normalized, and Partial Correlations

    OpenAIRE

    Kenett, Dror Y.; Shapira, Yoash; Ben-Jacob, Eshel

    2009-01-01

    We present here assessment of the latent market information embedded in the raw, affinity (normalized), and partial correlations. We compared the Zipf plot, spectrum, and distribution of the eigenvalues for each matrix with the results of the corresponding random matrix. The analysis was performed on stocks belonging to the New York ...

  2. 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…

  3. Refining the Classification of Children with Selective Mutism: A Latent Profile Analysis

    Science.gov (United States)

    Cohan, Sharon L.; Chavira, Denise A.; Shipon-Blum, Elisa; Hitchcock, Carla; Roesch, Scott C.; Stein, Murray B.

    2008-01-01

    The goal of this study was to develop an empirically derived classification system for selective mutism (SM) using parent-report measures of social anxiety, behavior problems, and communication delays. The sample consisted of parents of 130 children (ages 5-12) with SM. Results from latent profile analysis supported a 3-class solution made up of…

  4. PR.Latent-class methods to evaluate diagnostics tests for echinococcus infections in dogs.

    NARCIS (Netherlands)

    Hartnack, S.; Budke, C.M.; Craig, P.S.; Jiamin, Q.; Boufana, B.; Campos Ponce, M.; Torgerson, P.R.

    2013-01-01

    Background: The diagnosis of canine echinococcosis can be a challenge in surveillance studies because there is no perfect gold standard that can be used routinely. However, unknown test specificities and sensitivities can be overcome using latent-class analysis with appropriate data. Methodology: We

  5. Joint Textual And Visual Cues For Retrieving Images Using Latent Semantic Indexing

    OpenAIRE

    Pecenovic, Zoran; Ayer, Serge; Vetterli, Martin

    2001-01-01

    In this article we present a novel approach of integrating textual and visual descriptors of images in a unified retrieval structure. The methodology, inspired from text retrieval and information filtering is based on Latent Semantic Indexing (LS1).

  6. Comparing methods of classifying life courses: Sequence analysis and latent class analysis

    NARCIS (Netherlands)

    Elzinga, C.H.; Liefbroer, Aart C.; Han, Sapphire

    2017-01-01

    We compare life course typology solutions generated by sequence analysis (SA) and latent class analysis (LCA). First, we construct an analytic protocol to arrive at typology solutions for both methodologies and present methods to compare the empirical quality of alternative typologies. We apply this

  7. Comparing methods of classifying life courses: sequence analysis and latent class analysis

    NARCIS (Netherlands)

    Han, Y.; Liefbroer, A.C.; Elzinga, C.

    2017-01-01

    We compare life course typology solutions generated by sequence analysis (SA) and latent class analysis (LCA). First, we construct an analytic protocol to arrive at typology solutions for both methodologies and present methods to compare the empirical quality of alternative typologies. We apply this

  8. Latent heat storage by silica-coated polymer beads containing organic phase change materials

    Czech Academy of Sciences Publication Activity Database

    Feczkó, T.; Trif, L.; Horák, Daniel

    2016-01-01

    Roč. 132, July (2016), s. 405-414 ISSN 0038-092X R&D Projects: GA MŠk(CZ) LH14318 Institutional support: RVO:61389013 Keywords : latent heat storage * phase change materials * porous beads by suspension polymerization Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.018, year: 2016

  9. Complete genome sequence of currant latent virus (genus Cheravirus, family Secoviridae)

    Czech Academy of Sciences Publication Activity Database

    Petrzik, Karel; Koloniuk, Igor; Přibylová, Jaroslava; Špak, Josef

    2016-01-01

    Roč. 161, č. 2 (2016), s. 491-493 ISSN 0304-8608 Institutional support: RVO:60077344 Keywords : Stranded-RNA * complete genome sequence * Currant latent virus Subject RIV: EE - Microbiology, Virology Impact factor: 2.058, year: 2016

  10. Reactivation of Latent HIV-1 Expression by Engineered TALE Transcription Factors.

    Science.gov (United States)

    Perdigão, Pedro; Gaj, Thomas; Santa-Marta, Mariana; Barbas, Carlos F; Goncalves, Joao

    2016-01-01

    The presence of replication-competent HIV-1 -which resides mainly in resting CD4+ T cells--is a major hurdle to its eradication. While pharmacological approaches have been useful for inducing the expression of this latent population of virus, they have been unable to purge HIV-1 from all its reservoirs. Additionally, many of these strategies have been associated with adverse effects, underscoring the need for alternative approaches capable of reactivating viral expression. Here we show that engineered transcriptional modulators based on customizable transcription activator-like effector (TALE) proteins can induce gene expression from the HIV-1 long terminal repeat promoter, and that combinations of TALE transcription factors can synergistically reactivate latent viral expression in cell line models of HIV-1 latency. We further show that complementing TALE transcription factors with Vorinostat, a histone deacetylase inhibitor, enhances HIV-1 expression in latency models. Collectively, these findings demonstrate that TALE transcription factors are a potentially effective alternative to current pharmacological routes for reactivating latent virus and that combining synthetic transcriptional activators with histone deacetylase inhibitors could lead to the development of improved therapies for latent HIV-1 infection.

  11. 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…

  12. DIF Testing with an Empirical-Histogram Approximation of the Latent Density for Each Group

    Science.gov (United States)

    Woods, Carol M.

    2011-01-01

    This research introduces, illustrates, and tests a variation of IRT-LR-DIF, called EH-DIF-2, in which the latent density for each group is estimated simultaneously with the item parameters as an empirical histogram (EH). IRT-LR-DIF is used to evaluate the degree to which items have different measurement properties for one group of people versus…

  13. Visualization of latent blood stains using visible reflectance hyperspectral imaging and chemometrics

    NARCIS (Netherlands)

    Edelman, Gerda J.; van Leeuwen, Ton G.; Aalders, Maurice C.

    2015-01-01

    The detection of latent traces is an important aspect of crime scene investigation. Blood stains on black backgrounds can be visualized using chemiluminescence, which is invasive and requires a darkened room, or near-infrared photography, for which investigators need to change filters manually to

  14. "Latent" infection with Toxoplasma gondii: association with trait aggression and impulsivity in healthy adults.

    Science.gov (United States)

    Cook, Thomas B; Brenner, Lisa A; Cloninger, C Robert; Langenberg, Patricia; Igbide, Ajirioghene; Giegling, Ina; Hartmann, Annette M; Konte, Bettina; Friedl, Marion; Brundin, Lena; Groer, Maureen W; Can, Adem; Rujescu, Dan; Postolache, Teodor T

    2015-01-01

    Latent chronic infection with Toxoplasma gondii (T. gondii), a common neurotropic pathogen, has been previously linked with suicidal self-directed violence (SSDV). We sought to determine if latent infection with T. gondii is associated with trait aggression and impulsivity, intermediate phenotypes for suicidal behavior, in psychiatrically healthy adults. Traits of aggression and impulsivity were analyzed in relationship to IgG antibody seropositivity for T. gondii and two other latent neurotropic infections, herpes simplex virus 1 (HSV1) and cytomegalovirus (CMV). One thousand community-residing adults residing in the Munich metropolitan area with no Axis I or II conditions by SCID for DSM-IV (510 men, 490 women, mean age 53.6 ± 15.8, range 20-74). Plasma samples were tested for IgG antibodies to T. gondii, HSV-1 and CMV by ELISA. Self-reported ratings of trait aggression scores (Questionnaire for Measuring Factors of Aggression [FAF]) and trait impulsivity (Sensation-Seeking Scale-V [SSS-V]) were analyzed using linear multivariate methods. T. gondii IgG seropositivity was significantly associated with higher trait reactive aggression scores among women (p impulsive sensation-seeking (SSS-V Disinhibition) among younger men (p impulsivity, personality traits considered as endophenotypes for SSDV, are associated with latent T. gondii infection in a gender and age-specific manner, and could be further investigated as prognostic and treatment targets in T. gondii-positive individuals at risk for SSDV. Published by Elsevier Ltd.

  15. The Multi-state Latent Factor Intensity Model for Credit Rating Transitions

    NARCIS (Netherlands)

    Koopman, S.J.; Lucas, A.; Monteiro, A.

    2008-01-01

    A new empirical reduced-form model for credit rating transitions is introduced. It is a parametric intensity-based duration model with multiple states and driven by exogenous covariates and latent dynamic factors. The model has a generalized semi-Markov structure designed to accommodate many of the

  16. Role of scission and cross-linking in latent track formation in polymers

    Czech Academy of Sciences Publication Activity Database

    Hnatowicz, Vladimír

    2003-01-01

    Roč. 209, - (2003), s. 145-148 ISSN 0168-583X R&D Projects: GA ČR GA106/03/0514 Institutional research plan: CEZ:AV0Z1048901 Keywords : heavy ions * polymers * latent tracks Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.041, year: 2003

  17. Assessing the Reliability of Curriculum-Based Measurement: An Application of Latent Growth Modeling

    Science.gov (United States)

    Yeo, Seungsoo; Kim, Dong-Il; Branum-Martin, Lee; Wayman, Miya Miura; Espin, Christine A.

    2012-01-01

    The purpose of this study was to demonstrate the use of Latent Growth Modeling (LGM) as a method for estimating reliability of Curriculum-Based Measurement (CBM) progress-monitoring data. The LGM approach permits the error associated with each measure to differ at each time point, thus providing an alternative method for examining of the…

  18. Solidarity and conflict between adult children and parents: a latent class analysis

    NARCIS (Netherlands)

    van Gaalen, R.I.A.; Dykstra, P.A.

    2006-01-01

    Using multiple dimensions of solidarity and conflict in a latent class analysis, we develop a typology of adult child–parent relationships. The data (N= 4,990) are from the first wave of the Netherlands Kinship Panel Study. In descending order of relationship quality, the 5 types are harmonious

  19. High-temperature thermocline TES combining sensible and latent heat - CFD modeling and experimental validation

    Science.gov (United States)

    Zavattoni, Simone A.; Geissbühler, Lukas; Barbato, Maurizio C.; Zanganeh, Giw; Haselbacher, Andreas; Steinfeld, Aldo

    2017-06-01

    The concept of combined sensible/latent heat thermal energy storage (TES) has been exploited to mitigate an intrinsic thermocline TES systems drawback of heat transfer fluid outflow temperature reduction during discharging. In this study, the combined sensible/latent TES prototype under investigation is constituted by a packed bed of rocks and a small amount of encapsulated phase change material (AlSi12) as sensible heat and latent heat sections respectively. The thermo-fluid dynamics behavior of the combined TES prototype was analyzed by means of a computational fluid dynamics approach. Due to the small value of the characteristic vessel-to-particles diameter ratio, the effect of radial void-fraction variation, also known as channeling, was accounted for. Both the sensible and the latent heat sections of the storage were modeled as porous media under the assumption of local thermal non-equilibrium (LTNE). The commercial code ANSYS Fluent 15.0 was used to solve the model's constitutive conservation and transport equations obtaining a fairly good agreement with reference experimental measurements.

  20. Latent interface-trap building in power VDMOSFETs: new experimental evidence and numerical simulation

    International Nuclear Information System (INIS)

    Ristic, G.F.; Jaksic, A.B.; Pejovic, M.M.

    1999-01-01

    The paper presents new experimental evidence of the latent interface-trap buildup during annealing of gamma-ray irradiated power VDMOSFETs. We try to reveal the nature of this still ill-understood phenomenon by isothermal annealing, switching temperature annealing and switching bias annealing experiments. The results of numerical simulation of interface-trap kinetics during annealing are also shown. (authors)