RESUMEN
The gene regulatory circuitry through which pluripotent embryonic stem (ES) cells choose between self-renewal and differentiation appears vast and has yet to be distilled into an executive molecular program. We developed a data-constrained, computational approach to reduce complexity and to derive a set of functionally validated components and interaction combinations sufficient to explain observed ES cell behavior. This minimal set, the simplest version of which comprises only 16 interactions, 12 components, and three inputs, satisfies all prior specifications for self-renewal and furthermore predicts unknown and nonintuitive responses to compound genetic perturbations with an overall accuracy of 70%. We propose that propagation of ES cell identity is not determined by a vast interactome but rather can be explained by a relatively simple process of molecular computation.
Asunto(s)
Células Madre Embrionarias/metabolismo , Regulación de la Expresión Génica , Redes Reguladoras de Genes , Células Madre Pluripotentes/metabolismo , Factores de Transcripción/metabolismo , Animales , Técnicas de Cultivo de Célula , Biología Computacional , Ratones , Factores de Transcripción/genéticaRESUMEN
Artificially implementing the biological light reactions responsible for the remarkably efficient photon-to-charge conversion in photosynthetic complexes represents a new direction for the future development of photovoltaic devices. Here, we develop such a paradigm and present a model photocell based on the nanoscale architecture and molecular elements of photosynthetic reaction centers. Quantum interference of photon absorption and emission induced by the dipole-dipole interaction between molecular excited states guarantees an enhanced light-to-current conversion and power generation for a wide range of electronic, thermal, and optical parameters for optimized dipolar geometries. This result opens a promising new route for designing artificial light-harvesting devices inspired by biological photosynthesis and quantum technologies.
Asunto(s)
Modelos Químicos , Proteínas del Complejo del Centro de Reacción Fotosintética/química , Teoría CuánticaRESUMEN
OBJECTIVE: The importance of psychosocial factors in patients with Functional Bowel Disorders (FBD) has been well-established. However, most psychosocial measures used in research with FBD patients were not designed or validated on this population. A recent international team report recommended that psychosocial measures be developed to increase our understanding and treatment of FBD. The purpose of this study was to develop a reliable and valid instrument designed specifically to assess cognitions of patients with FBD. METHOD: An initial set of 204 scale items was generated from a large pool of thought diaries from patients diagnosed with FBD. Items were additionally refined using several methods, including consultation with a multidisciplinary team of international experts on FBD. The remaining 95 items were administered, along with a set of validating questionnaires, to a new sample of 75 FBD patients in Canada and the United States. RESULTS: The findings indicate that the final 25-item scale has high reliability (Cronbach's alpha = .93; inter-item correlation = .36); high concurrent criterion validity evidenced by the correlation of the scale with a global rating of life interference caused by bowel symptoms (r = .71; p<.001); acceptable convergent validity evidenced by the correlation of the scale with the Dysfunctional Attitudes Scale (r = .38; p<.01); high content validity and face validity; and minimal social desirability contamination (r = .15; NS). CONCLUSIONS: The Cognitive Scale for Functional Bowel Disorders is a valid and reliable scale that can be used as an outcome measure in evaluating the efficacy of different forms of psychotherapeutic intervention for FBD, and can also serve as a helpful assessment tool for health professionals working with patients diagnosed with FBD.
Asunto(s)
Enfermedades Funcionales del Colon/psicología , Inventario de Personalidad/estadística & datos numéricos , Trastornos Somatomorfos/psicología , Canadá , Terapia Cognitivo-Conductual , Enfermedades Funcionales del Colon/diagnóstico , Enfermedades Funcionales del Colon/terapia , Terapia Combinada , Humanos , Grupo de Atención al Paciente , Psicoterapia de Grupo , Derivación y Consulta , Rol del Enfermo , Trastornos Somatomorfos/diagnóstico , Trastornos Somatomorfos/terapia , Resultado del Tratamiento , Estados UnidosRESUMEN
This article is divided into two parts, the first of which focuses on a general overview of irritable bowel syndrome (IBS) and provides a rationale for the use of cognitive-behavioral therapy (CBT) for IBS based on both theoretical and research perspectives. This section includes a critical review of CBT therapies for IBS and provides a model of CBT for IBS. The second section provides the clinician with practical information concerning the application of cognitive-behavioral group therapy for IBS. Possible scripts and case examples are incorporated into this section to highlight factors that may arise in working with IBS patients relative to other clinical groups. The second section also contains themes that are suggested content areas for group sessions. Contingent on the formulation of the presenting or emerging issues and goals, the order and inclusion of themes can be changed to fit the particular needs of a given group. Finally, this section provides initial preliminary data from a randomized controlled study that is suggestive of the efficacy of cognitive-behavioral therapy for IBS.
Asunto(s)
Terapia Conductista/métodos , Terapia Cognitivo-Conductual/métodos , Enfermedades Funcionales del Colon/psicología , Enfermedades Funcionales del Colon/terapia , Psicoterapia de Grupo/métodos , Adulto , Enfermedades Funcionales del Colon/complicaciones , Enfermedades Funcionales del Colon/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Psicológicos , OntarioRESUMEN
PIP: Millions of people have become refugees or been displaced within Afghanistan during 17 years of war within the country. Conversations with women in a camp for the displaced reveal what it means for women to lose their homes, especially in the context of ongoing instability and conflict. Sections discuss homelessness in Kabul, linking psycho-social and practical needs, coping with dislocation, stability and land ownership, mobility and security, family breakdown, temporary and permanent settlements, and meeting needs versus creating dependency. The author concludes that among people displaced from their homes for so many years, their physical and spiritual homes nonetheless remain inseparable from their lives. It is important to maintain the individual notion of home if life is to be worth living and hope retained. Relief agencies must help in an appropriate manner and to an appropriate extent. Oxfam has been working beyond the refugee camps, in a return to the city of Kabul, since July 1995. When this article was written, the NGO was involved in a joint venture to restore the piped water supply which, like the electricity supply, was looted and damaged. It also plans to distribute plastic sheeting for use as roofs and floor covering during the winter. Oxfam currently plans discreet activities rather than an integrated approach.^ieng
Asunto(s)
Relaciones Interpersonales , Organizaciones , Refugiados , Afganistán , Asia , Demografía , Países en Desarrollo , Emigración e Inmigración , Población , Dinámica Poblacional , MigrantesRESUMEN
Echocardiographic and Doppler-derived measurements of left ventricular (LV) function at rest were examined as predictors of maximal bicycle exercise capacity in a homogeneous group of 115 patients with mild to moderate LV dysfunction (ejection fraction 22 to 56%, median 43%) participating in the DEFIANT study of nisoldipine after acute myocardial infarction. Although the relations were not exact, peak exercise work load 7 weeks after infarction correlated with measurements of diastolic LV function at rest. Exercise work load was inversely related to peak late diastolic transmitral blood flow velocity (A wave) (slope -86.6; 95% confidence interval -120.9 to -52.2) and directly to the E/A ratio (slope 20.5; 95% confidence interval 6.0 to 35.1). The relations between exercise work load and peak late diastolic flow velocity remained significant after correction for age, sex, heart rate at rest, and use of beta-blocking drugs or nisoldipine. There was no relation between peak exercise work load and peak early diastolic transmitral flow velocity (E wave), isovolumic relaxation period or deceleration time. Measurements of systolic LV function (LV end-diastolic and end-systolic volumes, and ejection fraction, stroke volume and cardiac index) were also not significant as predictors of exercise capacity.