bluuebunny/crossref_metadata_2025 huggingface dataset:
Luminescence in diamonds of the São Luiz placer (Brazil)
Authors: Mironov V.P. , Rakevich A.L. , Stepanov F.A. , Emel’yanova A.S. , Zedgenizov D.A. , Shatsky V.S. , Kagi H. , Martynovich E.F.
Published: May 2015

Plates made of diamonds from the São Luiz province (Brazil) were investigated by confocal scanning luminescence microscopy. The samples have many macroinhomogeneities (cracks and inclusions), but there is a quasi-uniform distribution of luminescence centers in the bulk. At all investigated points of the crystals, the same group of centers was observed: N3, H4, 575, and a red band with a maximum at 690–700 nm. The visible nonuniformities in the distribution of luminescence over the area of the plates are determined by relatively small fluctuations in the ratio of the intensities of individual bands in the spectra. Nitrogen centers of different degrees of aggregation (H4, N3, and 575 nm, with four, three, and one nitrogen atom, respectively) coexist in these crystals. In the same zones of the samples, the distribution of blue luminescence (N3 centers) is diffuse (uniform), but the distribution of yellow-green luminescence is characterized by layering on (111). This might be a consequence of the tangential growth of octahedron faces or a result of plastic deformation of the crystals and dislocations along (111).
Gravity monitoring at oil and gas fields: data inversion and errors
Authors: Vasilevskiy A.N. , Dashevsky Yu.A.
Published: May 2015

The present paper considers certain problems of gravity monitoring at oil and gas fields arising due to inversion of repeat measurement data, when finding the positions of water–oil and water–gas contacts. The main sources of noise in gravity data are errors in vertical positioning of the tool, changes in atmospheric pressure, and variations in groundwater level and soil moisture. An algorithm based on using a multisensor borehole tool is proposed for a more accurate inversion. Examples of locating successfully the water front while solving model problems with the help of this algorithm are provided.
X-ray tomography in petrophysical studies of core samples from oil and gas fields
Authors: Galkin S.V. , Efimov A.A. , Krivoshchekov S.N. , Savitskiy Ya.V. , Cherepanov S.S.
Published: May 2015

The porosity and permeability of core rocks were studied by X-ray tomography. This method has a high potential for studying petrophysical properties of rocks, because it permits not only a general quantitative estimation of the void volume but also visualization of the rock texture, including pores, cavities, cracks, and zones of different densities in the matrix. X-ray tomography permits detailed studies of rock inhomogeneity, which are necessary for the elaboration of reliable porosity–permeability models for hydrocarbon pools. The investigations at Perm State National Research Polytechnic University have shown that X-ray tomography of core samples has a wide spectrum of applications in petroleum geology. Nikon Metrology XT H 225 X-ray computed tomography makes it possible to examine samples with a standard diameter (30 mm) and whole core samples (100 mm). The structure of voids in carbonate and terrigenous rocks was studied on samples with standard and full diameters; the results of hydrochloric acid treatment of carbonate reservoir rocks were visualized; and the mechanical properties of rock salts were studied. Three-dimensional models for the structure of voids and mineral matrix of the core samples have been constructed with the use of the Avizo Fire software.
¿Debo utilizar el aprendizaje en línea?
Authors: Cook MD David A.
Published: May 2015

El aprendizaje en línea ha llegado para quedarse. Las computadoras en todos sus tamaños y capacidades se han vuelto omnipresentes, y se han integrado en nuestra sociedad a todos los  niveles de la clase socioeconómica. Nos sentimos cada vez más cómodos con las computadoras, y las computadoras son tan fáciles de manejar, que a menudo nos olvidamos que las estamos usando.
Uso y utilidad de la videoconferencia en la enseñanza de asignaturas preclínicas de medicina en la Universidad Latina de Panamá (ULAT)
Authors: Córdova Alfredo , Staff Carlos , Cubilla Fulvia
Published: May 2015

Introducción: La videoconferencia es un servicio de comunicación que puede ser utilizado en cualquier nivel educativo, y especialmente en la enseñanza superior.

Objetivo: Explorar el punto de vista del alumno, respecto a recibir la enseñanza de la Licenciatura de Medicina, a través de la videoconferencia en una asignatura preclínica.

Método: La muestra que se reporta es de 95 estudiantes. Se seleccionó de los alumnos matriculados en seis semestres de la asignatura de fisiología, con una media de 14-18 alumnos para cada semestre estudiado. Para la exploración de la videoconferencia como método de enseñanza, se realizó una encuesta a los estudiantes, en la cual se interrogó acerca del desarrollo, interacción y utilidad del uso de la videoconferencia en la asignatura.

Resultados: Cabe resaltar de los resultados, que para los estudiantes se estableció una relación académica adecuada con los profesores que impartieron teoría a través de la video conferencia.

Discusión: La videoconferencia como método de enseñanza aunque sea a distancia es en momento real, es un medio y/o método útil en la enseñanza de medicina, al menos en las asignaturas preclínicas.
La técnica de grupos focales
Authors: Hamui-Sutton Alicia , Varela-Ruiz Margarita
Published: May 2015

¿Qué son los grupos focales?, ¿cuándo surgen?, ¿cuáles son sus fundamentos teóricos?, ¿cómo se lleva a cabo esta técnica?, ¿qué utilidad presta a la educación médica? Son las preguntas que guían el presente artículo, cuya finalidad es ofrecer un panorama de la técnica de grupos focales. Es una herramienta de la investigación cualitativa, que ha demostrado ser una fuente de información de enorme riqueza, para la investigación en educación médica, por su sensibilidad para indagar conocimientos, normas y valores de determinados grupos.
Noticias y eventos en educación en Ciencias de la Salud
Authors: Editorial Oficina
Published: May 2015

Eventos académicos.

Recomendación de libro.
Facultad de Medicina, UNAM.
Authors: Editorial Oficina
Published: May 2015

Medical Science Educator es una publicación, con revisión por pares, de la Asociación Internacional de Educadores en Ciencias Médicas (IAMSE). Esta publicación ofrece a todos los educadores del área en la atención de la salud, la información más actualizada para el éxito en su actividad, al publicar actividades, opiniones y recursos académicos en educación en ciencias médicas. Los artículos publicados se enfocan en enseñar las ciencias que son el fundamento de la medicina y la salud modernas, e incluyen la educación en ciencia básica, enseñanza clínica, y el uso de las tecnologías modernas en la educación. La revista es un beneficio de la membresía en IAMSE, pero se puede adquirir como suscripción individual o bibliotecaria.
Educación en ciencias de la salud, caleidoscopio de oportunidades
Authors: Sánchez-Mendiola Melchor
Published: May 2015

“No llores porque ya terminó,sonríe porque sucedió”.Gabriel García Márquez

En las actividades cotidianas de cada uno de nosotros se mezclan, como en un caleidoscopio, las vivencias de nuestras facetas personales y profesionales, a pesar de que tradicionalmente se nos enseña a mantenerlas separadas.
Estrategias docentes en el primer año de la carrera de Médico Cirujano y nivel de aprovechamiento académico
Authors: Urrutia-Aguilar María Esther , Guevara-Guzmán Rosalinda
Published: May 2015

Introducción: El docente es un coadyuvante del éxito o fracaso académico de los estudiantes en el primer año de sus estudios universitarios; sin duda, las estrategias de enseñanza utilizadas en el aula son determinantes para la formación del perfil de egreso.

Objetivo: Relacionar la opinión de los estudiantes sobre las estrategias de enseñanza utilizadas por el profesor en el aula y el aprovechamiento académico de los estudiantes.

Método: Estudio longitudinal, comparativo y pareado. La población de estudio estuvo constituida de 95 profesores que impartieron clase en las asignaturas de Anatomía, Biología Celular, Biología del Desarrollo y Bioquímica durante el ciclo escolar 2006-2007. Para evaluar el aprovechamiento académico de los estudiantes se realizó una comparación entre su promedio de ingreso y egreso. Para explorar la opinión de los estudiantes se utilizó un instrumento validado con 30 reactivos.

Resultados: Este trabajo aportó cuatro tipos de desempeño docente según el promedio de estrategias de enseñanza y de aprovechamiento académico de los estudiantes.

Conclusiones: Los resultados obtenidos denotan la urgencia de impartir formación docente en estrategias de enseñanza, con la finalidad de que los profesores enseñen a los futuros médicos lo que necesitan saber y lo que requieren saber hacer.
La educación en línea: una metodología flexible para formación de residentes de Psiquiatría
Authors: Campillo-Serrano Carlos Daniel , Morales-Gordillo Nadia , Dayran Trejo-Márquez Hugo , Ramírez-Martínez José Luis , Castañeda-Medina Itzamná Kukulkán , Gallegos-Cázares Rogelio , Gálvez-Flores Ana Mirna , Rosas-Magallanes Cynthia
Published: May 2015

Introducción: La educación a distancia es una herramienta eficaz para la enseñanza médica, soluciona los problemas de acceso a la información y homogeneíza la calidad de la educación, fomenta el autoaprendizaje y facilita al estudiante seguir desarrollando competencias y habilidades para su vida profesional.

Objetivo: Mostrar la experiencia sobre el desarrollo y la elaboración de un curso virtual para médicos residentes en Psiquiatría en México.

Método: Se estableció un convenio entre el Instituto Nacional de Salud Pública (INSP) y los Servicios de Atención Psiquiátrica (SAP), que permitió realizar un curso virtual de Sistemas de Salud, parte de la currícula de la especialidad en Psiquiatría. El INSP capacitó a los profesores en diseño instruccional y uso de la plataforma Moodle. Mediante ésta, se midieron las siguientes variables: número de visitas al material bibliográfico, tiempo en la realización de cuestionarios, en la evaluación diagnóstica y en la final, así como la calificación de los mismos; tiempo de permanencia total en plataforma, número de visitas a todos los recursos didácticos y registro de participaciones en dos foros.

Resultados: Participaron 26 alumnos, observándose: tiempo de permanencia en plataforma de 90 min/día, mediana de tiempo invertido en evaluaciones de 1.75 horas, el 38.46% consultó todas las lecturas, se registraron 767 visitas para el primer foro y 448 en el segundo, quienes participaron más de dos veces obtuvieron una calificación final de 92.53. No hubo correlación estadísticamente significativa para ninguna de las variables anteriores.

Conclusiones: Estos cursos requieren colaboración interinstitucional e interdisciplinaria, asícomo su inclusión en los presupuestos de los programas de residencias médicas. La plataforma permitió registrar las actividades de los alumnos, siendo una ventaja sobre la educación tradicional. El tiempo de permanencia en la plataforma fue superior al del aula. Los foros fueron la estrategia de mayor aprendizaje, observándose una participación de mejor calidad.
Cienciometría para ciencias médicas: definiciones, aplicaciones y perspectivas
Authors: Michán Layla , Muñoz-Velasco Israel
Published: May 2015

La cienciometría o bibliometría consiste en el análisis cuantitativo de la producción científica (en especial los artículos científicos), para investigar el desarrollo, estructura, dinámica, tendencias y relaciones de la práctica científica. Su desarrollo es uno de los efectos de la revolución digital en la ciencia, su uso en la medicina ha aumentado y las aplicaciones bibliométricas en el área médica pueden clasificarse en cinco categorías: recuperación de literatura, obtención de nuevo conocimiento, revisiones bibliográficas, análisis de las ciencias médicas, evaluación, gestión y política para medicina, se dan ejemplos de cada una. Los millones de datos médicos que se generan a partir de la literatura, los miles de colecciones bibliográficas que existen y los cientos de aplicaciones que hay en la actualidad para procesar y analizar la literatura, indican la importancia de preparar especialistas en México de alto nivel, capaces de dominar el procesamiento de literatura electrónica por métodos de innovadores y de vanguardia como la cienciometría. El primer paso para lograr este objetivo consistirá en enseñar a los médicos en formación las características, ventajas y perspectivas de este método.
La escuela universitaria y la escuela de la vida: ¿Yin y yang?
Authors: Sánchez-Mendiola Melchor
Published: May 2015

“Nunca he dejado que la escuela interfiera con mi educación”.Mark Twain

El proceso educativo en el ser humano posee una infinidad de aristas que han sido estudiadas por académicos de diversas disciplinas. Una de ellas es el enorme contraste y complementariedad de la educación tal como ocurre en las aulas de las universidades, con el aprendizaje que acontece durante la “escuela de la vida”, en las experiencias vivenciales de los educandos.
Actividad docente facilitadora para la adquisición de aprendizajes significativos y compromiso social
Authors: Moreno-Altamirano Laura , García-García Juan José , Urbina-Cedillo Clara , García-de la Torre Guadalupe S.
Published: May 2015

Introducción: Mediante la actividad facilitadora por parte del docente, se identificó desvinculación de la teoría con una práctica, para lo cual se propuso el estudio de un problema de la Salud Pública.

Objetivo: La finalidad fue identificar si la actividad docente facilitadora fue de utilidad para integración de conocimientos, adquisición de aprendizajes significativos y compromiso social, al promover la participación activa de los estudiantes en la identificación de un problema académico y la reflexión y sistematización del proceso para su solución.

Método: Se adoptó una metodología semejante a la “Investigación-Acción” (IA). Los alumnos del tercer año de la carrera de medicina, fueron los protagonistas del proceso de identificación de la desvinculación entre la teoría y la práctica. Se eligió la diabetes tipo 2 como problema de Salud Pública, se estudió en una comunidad rural de México la relación entre niveles de glucosa en sangre y características sociodemográficas, antropométricas y otros posibles factores de riesgo relacionados. Se indagó el beneficio que tuvo la actividad en cuanto a la aplicación, integración de los conocimientos de la carrera, la relación médico-paciente, el compromiso social e importancia del trabajo comunitario y el papel de la investigación epidemiológica, como estrategia para alcanzar un aprendizaje significativo.

Resultados: Más del 90% de los alumnos señaló que la actividad les permitió integrar-aplicar lo aprendido previamente; identificó a la diabetes como un problema social y señaló que todos los estudiantes de medicina deberían participar en este tipo de trabajos, ya que la investigación ligada a la acción es una buena estrategia de aprendizaje.

Conclusiones: La actividad realizada permitió a los alumnos obtener un aprendizaje significativo al identificar sus limitaciones académicas, aplicar sus conocimientos y desarrollar ciertas habilidades, además de percatarse de que la educación para la salud constituye un campo disciplinario que debe estar enfocado a quienes va dirigido el mensaje.
Cómo elaborar una práctica de fisiología con un enfoque por competencias
Authors: E. García Erasmo David
Published: May 2015

Estas pautas reúnen nueve puntos básicos que deben considerarse en el diseño de una práctica del laboratorio de fisiología, orientadas hacia el logro de competencias médicas. Hacen énfasis en el proceso de transferencia del aprendizaje como parte del ejercicio del estudiante, en el desarrollo de competencias médico-clínicas. Están basadas en un modelo de aprendizaje significativo, como estrategia en educación médica para identificar un problema y abordarlo con una actitud crítica y propositiva. Finalmente, destacan el paralelismo entre el método científico y el método clínico, además de subrayar la relevancia del proceso sobre el resultado final como una característica de la evaluación formativa, elemento crítico en el mejoramiento continuo de un programa por competencias médicas.
Formas de enseñanza y evaluación utilizadas por los docentes de Odontología: resultados y su clasificación psicopedagógica
Authors: Espinosa-Vázquez Olivia , Martínez-González Adrián , Díaz-Barriga Arceo Frida
Published: May 2015

Introducción: Se presenta un estudio de la manera de enseñar y evaluar de los profesores que imparten el Plan de Estudios de Cirujano Dentista de la Facultad de Odontología (FO), UNAM, vigente desde 1992.

Objetivo: Identificar las principales formas de enseñanza y evaluación utilizadas por los docentes de la FO, y clasificarlas psicopedagógicamente.

Método: Estudio observacional, transversal, exploratorio tipo encuesta con escala Likert. Los datos se analizaron con SPSS (Alfa de Cronbach=0.880) a través de estadística descriptiva y con un análisis factorial exploratorio.

Resultados: De una muestra de 484 profesores (45.6% mujeres, 54.4% hombres), se determinó que las principales formas de enseñanza utilizadas son: los profesores realizan preguntas sobre temas vistos previamente y la exposición de temas por parte del profesor; las que menos: el dictado y la exposición por parte de los estudiantes. Respecto a las estrategias de enseñanzaaprendizaje utilizan principalmente: demostraciones, ilustraciones y análisis de casos. Las formas de evaluación de la teoría más utilizadas son: participación en clase, exámenes de opción múltiple y listas de control; y en la práctica: exámenes de opción múltiple, número de trabajos y listas de control.

Discusión: De las formas de enseñanza y evaluación que los profesores utilizan, algunas son más eficaces ya que fomentan la solución de problemas, y promueven una fuerte motivación en el estudiante.

Conclusiones: Los profesores utilizan pocas formas de enseñanza y evaluación con diferente enfoque; prevalece la enseñanza centrada en el profesor y el uso excesivo de formas de evaluación relacionadas con el área cognoscitiva, el cumplimiento de tratamientos y el saber teórico de los procedimientos. Se sugiere crear conciencia y enriquecer las prácticas educativas habituales con capacitación continua y actualización constante, respecto a las formas de evaluación fundamentadas en la construcción del conocimiento y en el desarrollo de habilidades y actitudes profesionales.
Church Discipline Chronicled – A New Source for Basel Mission Historiography
Authors: Beutter Anne
Published: May 2015

This article uses a hitherto overlooked category of historical source, an outstation chronicle covering the period 1911‒1920. It shows how juridical practice within the Protestant mission church of Nkoranza (then in the Ashanti region of what is now central Ghana) created and sharpened a Christian group identity in a predominantly non-Christian context. It is argued that the interdependence of the in-group and out-group at the local level helped to shape the church’s juridical forms.
Oral administration of Bifidobacterium breve B-3 modifies metabolic functions in adults with obese tendencies in a randomised controlled trial
Authors: Minami Jun-ichi , Kondo Shizuki , Yanagisawa Naotake , Odamaki Toshitaka , Xiao Jin-zhong , Abe Fumiaki , Nakajima Shigeru , Hamamoto Yukie , Saitoh Sanae , Shimoda Taeko
Published: May 2015

Accumulating evidence suggests an association between gut microbiota and the development of obesity, raising the possibility of probiotic administration as a therapeutic approach. Bifidobacterium breve B-3 was found to exhibit an anti-obesity effect on high-fat diet-induced obesity mice. In the present study, a randomised, double-blind, placebo-controlled trial was conducted to evaluate the effect of the consumption of B. breve B-3 on body compositions and blood parameters in adults with a tendency for obesity. After a 4-week run-in period, the participants were randomised to receive either placebo or a B-3 capsule (approximately 5 × 1010 colony-forming units of B-3/d) daily for 12 weeks. A significantly lowered fat mass was observed in the B-3 group compared with the placebo group at week 12. Improvements were observed for some blood parameters related to liver functions and inflammation, such as γ-glutamyltranspeptidase and high-sensitivity C-reactive protein. Significant correlations were found between the changed values of some blood parameters and the changed fat mass in the B-3 group. These results suggest the beneficial potential of B. breve B-3 in improving metabolic disorders.
FORMAL GROUPS AND INVARIANT DIFFERENTIALS OF ELLIPTIC CURVES
Authors: SADEK MOHAMMAD
Published: May 2015

In this paper, we find a power series expansion of the invariant differential ${\it\omega}_{E}$ of an elliptic curve $E$ defined over $\mathbb{Q}$, where $E$ is described by certain families of Weierstrass equations. In addition, we derive several congruence relations satisfied by the trace of the Frobenius endomorphism of $E$.
EXACT UPPER AND LOWER BOUNDS ON THE DIFFERENCE BETWEEN THE ARITHMETIC AND GEOMETRIC MEANS
Authors: PINELIS IOSIF
Published: May 2015

Exact upper and lower bounds on the difference between the arithmetic and geometric means are obtained. The inequalities providing these bounds may be viewed, respectively, as a reverse Jensen inequality and an improvement of the direct Jensen inequality, in the case when the convex function is the exponential.
‘No Room for Class Struggle in These National Undertakings’: Providing social welfare for Indian state sector industrial workers (circa 1950–2000)
Authors: SUBRAMANIAN DILIP
Published: May 2015

Independent India's new state-owned infrastructural industries were not only entrusted with the mission of producing essential public commodities, but they were also required to promote the economic and social advancement of their workforces. To achieve this objective, big public enterprises in particular, helped by the financial power they derived from their control over the strategic sectors of the domestic economy, established generously endowed welfare programmes. This article argues that such a developmental ideology shaping managerial policy orientations is central to understanding why accepted explanations for the rationale of employer-sponsored social benefits are insufficient when it comes to studying similar initiatives in the Indian public sector. To substantiate its argument, the article explores the provisioning of social needs over a period of roughly half a century (1948–2002) at a large state-run producer of telecommunications equipment, Indian Telephone Industries. The welfare regime as it evolved here boasted one unique feature: it rested on dual foundations, with both the company and the trade union assuming independent responsibility for the well-being of employees. A range of informal self-help schemes devised by workers further supplemented the institutionalized social security net set up by the management and the union. The article also discusses how the firm sought to scale back its largesse in the aftermath of economic liberalization.
Regional Red List assessment of tree species in upper montane forests of the Tropical Andes
Authors: Tejedor Garavito Natalia , Newton Adrian C. , Oldfield Sara
Published: May 2015

The Tropical Andes are characterized by a high level of endemism and plant species richness but are under pressure from human activities. We present the first regional conservation assessment of upper montane tree species in this region. We identified 3,750 tree species as occurring in this region, of which 917 were excluded because of a lack of data on their distribution. We identified a subset of 129 taxa that were restricted to higher elevations (> 1,500 m) but occurred in more than one country, thus excluding local endemics evaluated in previous national assessments. Distribution maps were created for each of these selected species, and extinction risk was assessed according to the IUCN Red List categories and criteria (version 3.1), drawing on expert knowledge elicited from a regional network of specialists. We assessed one species, Polylepis microphylla, as Critically Endangered, 47 species as Endangered and 28 as Vulnerable. Overall, 60% of the species evaluated were categorized as threatened, or 73% if national endemics are included. It is recommended that extinction risk assessments for tree species be used to inform the development of conservation strategies in the region, to avoid further loss of this important element of biodiversity.
Characterization of hydrochlorothiazide in solid formulations
Authors: de Salvi Simone T. B. , Tita Diego Luiz , Paiva-Santos Carlos de O. , Antonio Selma G.
Published: May 2015

Hydrochlorothiazide (HCTZ) is a diuretic used for the treatment of blood pressure (hypertension). HCTZ has two anhydrous polymorphs denoted as Forms I and II. Aiming at solid-state characterization, X-ray powder diffraction (XRPD) is known to be a powerful technique which has been successfully applied in investigating polymorphism in medicines. In this work, three tablets of HCTZ (a reference and two generic) were analyzed. The data were collected using Rigaku RINT2000 diffractometer copper rotate anode. The Rietveld method (RM) was applied for the characterization of HCTZ polymorphic form. For the crystalline excipients where the crystal structure is known, their phases were identified by the RM either. The results showed that all the tablets exhibit Form I of HCTZ, while the excipient lactose monohydrate is found to exhibit the crystalline form. One of the generics is also found to exhibit the excipient sodium lauryl sulfate (SLS) in the crystalline form. Therefore, the RM and XRPD are an efficient methodology for characterization of the crystalline Form I of the active principle of HCTZ and crystalline excipients lactose monohydrate and SLS in solid formulations. It is also interesting to observe excipients not described in the package insert of the medicament.
The contribution of neighbours to an individual's risk of typhoid outcome
Authors: CHAO D. L. , PARK J. K. , MARKS F. , OCHIAI R. L. , LONGINI I. M. , HALLORAN M. E.
Published: May 2015

An individual's risk of infection from an infectious agent can depend on both the individual's own risk and protective factors and those of individuals in the same community. We hypothesize that an individual's exposure to an infectious agent is associated with the risks of infection of those living nearby, whether their risks are modified by pharmaceutical interventions or by other factors, because of the potential for transmission from them. For example, unvaccinated individuals living in a highly vaccinated community can benefit from indirect protection, or living near more children in a typhoid-endemic region (where children are at highest risk) might result in more exposure to typhoid. We tested this hypothesis using data from a cluster-randomized typhoid vaccine trial. We first estimated each individual's relative risk of confirmed typhoid outcome using their vaccination status and age. We defined a new covariate, potential exposure, to be the sum of the relative risks of all who live within 100 m of each person. We found that potential exposure was significantly associated with an individual's typhoid outcome, and adjusting for potential exposure affected estimates of vaccine efficacy. We suggest that it is useful and feasible to adjust for spatially heterogeneous distributions of individual-level risk factors, but further work is required to develop and test such approaches.
A hydrodynamic model for silicon semiconductors including crystal heating
Authors: MASCALI GIOVANNI
Published: May 2015

We present a macroscopic model for describing the electrical and thermal behaviour of silicon devices. The model makes use of a set of macroscopic state variables for phonons and electrons that are moments of their respective distribution functions. The evolution equations for these variables are obtained starting from the Bloch–Boltzmann–Peierls kinetic equations for the phonon and the electron distributions, and are closed by means of the maximum entropy principle. All the main interactions between electrons and phonons, the scattering of electrons with impurities, as well as the scattering of phonons among themselves are considered. In particular, we propose a treatment of the optical phonon decay directly based on the expression of its transition rate (Klemens 1966Phys. Rev.148 845; Aksamija & Ravaioli 2010Appl. Phys. Lett.96, 091911). As an application of the model, we evaluate the silicon thermopower.
Existence and uniqueness of a thermoelastic problem with variable parameters
Authors: BARRAL P. , NAYA-RIVEIRO M. C. , QUINTELA P.
Published: May 2015

The aim of this article is to study the existence and uniqueness of solution for a quasistatic fully coupled thermoelastic problem arising from some metallurgical processes. We consider mixed boundary conditions for both submodels, and a Robin boundary condition for the thermal one. Furthermore, the reference temperature, the thermal conductivity and the Lamé's parameters are assumed to depend on the material point.
The neurobiology of aggression and violence
Authors: Rosell Daniel R. , Siever Larry J.
Published: May 2015

Aggression and violence represent a significant public health concern and a clinical challenge for the mental healthcare provider. A great deal has been revealed regarding the neurobiology of violence and aggression, and an integration of this body of knowledge will ultimately serve to advance clinical diagnostics and therapeutic interventions. We will review here the latest findings regarding the neurobiology of aggression and violence. First, we will introduce the construct of aggression, with a focus on issues related to its heterogeneity, as well as the importance of refining the aggression phenotype in order to reduce pathophysiologic variability. Next we will examine the neuroanatomy of aggression and violence, focusing on regional volumes, functional studies, and interregional connectivity. Significant emphasis will be on the amygdala, as well as amygdala–frontal circuitry. Then we will turn our attention to the neurochemistry and molecular genetics of aggression and violence, examining the extensive findings on the serotonergic system, as well as the growing literature on the dopaminergic and vasopressinergic systems. We will also address the contribution of steroid hormones, namely, cortisol and testosterone. Finally, we will summarize these findings with a focus on reconciling inconsistencies and potential clinical implications; and, then we will suggest areas of focus for future directions in the field.
New record of the frogfish Fowlerichthys avalonis (Actinopterygii, Antennariidae) at the oceanic Revillagigedo Archipelago, west Mexico
Authors: Ayala-Bocos Arturo , Hoyos-Padilla Mauricio , García-Benito Diana , Martínez-Castillo Violeta
Published: May 2015

The roughbar frogfish,Fowlerichthys avalonis, is one of the largest frogfish residents of rocky bottoms, at depths of 10 to 300 m, inhabiting the eastern Pacific. It is an endemic species with a geographic range along the continental shelf from the southern United States to Chile. This study provides evidence for the occurrence of the species at Socorro Island (18°46′19″N 110°53′43″W), Revillagigedo Archipelago, Mexico, obtained from videos taken in a submersible at a depth of 66 m. This report extends the known distribution ofF. avalonisto 400 km off the mainland coast of the Americas, and represents the fourth species of the family Antennariidae to be reported for the Revillagigedo Archipelago.
First record of Beroe gracilis Künne, 1939 (Ctenophora: Beroida: Beroidae) from Norway, found in a Mnemiopsis leidyi A. Agassiz, 1865 bloom
Authors: Ringvold Halldis , Shiganova Tamara A. , Knott K. Emily , Galil Bella S.
Published: May 2015

In September 2014 an unusual mixture of ctenophores was recorded at Arboretet, south-western Norway and at Flødevigen, near Arendal on the south coast of Norway. In addition to the invasive American lobate ctenophore,Mnemiopsis leidyi, the common northern lobate ctenophoreBolinopsis infundibulumand the cydippidPleurobrachia pileus, two beroid ctenophores, were noted –Beroe cucumisandBeroegracilis. The latter species had not been documented before in Norwegian waters.
Observation of a living macroalga at 166 m in a high Arctic fjord
Authors: Meyer Kirstin S. , Sweetman Andrew K.
Published: May 2015

Still photos of the seafloor in Raudfjorden, Spitsbergen, recorded in 2011, showed an abundant macroalga at a depth of 166 m. The macroalga was observed attached to stones of varying size and streaming in the bottom current, which would imply that the alga was alive and growingin situ. The alga likely experiences very low-light conditions, as it is present in a turbid fjord influenced by glacial sedimentation. Arctic macroalgae are often adapted to low-light conditions, but to the authors’ knowledge, the present report is the deepest record of living macroalgae in the high Arctic.
Maternal and early life factors of tooth emergence patterns and number of teeth at 1 and 2 years of age
Authors: Ntani G. , Day P. F. , Baird J. , Godfrey K. M. , Robinson S. M. , Cooper C. , Inskip H. M. ,   the Southampton Women’s Survey Study Group
Published: May 2015

Various environmental factors have been associated with the timing of eruption of primary dentition, but the evidence to date comes from small studies with limited information on potential risk factors. We aimed to investigate associations between tooth emergence patterns and pre-conception, pregnancy and postnatal influences. Dentition patterns were recorded at ages 1 and 2 years in 2915 children born to women in the Southampton Women’s Survey from whom information had been collected on maternal factors before conception and during pregnancy. In mutually adjusted regression models we found that: children were more dentally advanced at ages 1 and 2 years if their mothers had smoked during pregnancy or they were longer at birth; mothers of children whose dental development was advanced at age 2 years tended to have poorer socioeconomic circumstances, and to have reported a slower walking speed pre-pregnancy; and children of mothers of Asian ethnicity had later tooth development than those of white mothers. The findings add to the evidence of environmental impacts on the timing of the eruption of primary dentition in indicating that maternal smoking during pregnancy, socio-economic status and physical activity (assessed by reported walking speed) may influence the child’s primary dentition. Early life factors, including size at birth are also associated with dentition patterns, as is maternal ethnicity.
The Emotions Sumanai, Gratitude, and Indebtedness, and Their Relations to Interpersonal Orientation and Psychological Well-Being Among Japanese University Students
Authors: Washizu Naoko , Naito Takashi
Published: May 2015

Sumanai is a Japanese word that refers to a feeling in response to a favor; it includes gratitude, along with sorrow and sometimes guilt for having put the benefactor to so much trouble. The purpose of the current research was to explore sumanai, gratitude, and indebtedness, and their relations to interpersonal orientation and psychological well-being. Results from Study 1 with 115 female Japanese university students confirmed the distinct meanings of gratitude, sumanai, and indebtedness in terms of their dissimilar correlations with other feelings. The results also revealed that when the benefactor’s expectation for repayment was manipulated, gratitude and sumanai, but not indebtedness, decreased with increasing benefactor expectations. In Study 2 with a sample of 179 female Japanese university students, sumanai had a significant positive correlation with interpersonal orientation but did not have a significant positive correlation with psychological well-being. Interpersonal orientation mediated the relation between indebtedness and psychological well-being, but did not mediate the relation between gratitude and psychological well-being. Gratitude had significant direct paths to psychological well-being and interpersonal orientation. An alternative model was also supported; gratitude mediated the relation between interpersonal orientation and psychological well-being. The contribution of gratitude to well-being and interpersonal orientation are consistent with the extant literature, pointing to gratitude’s ability to build and maintain social relationships.
On resin synthesis and cross-linking of collagen peptides containing the advanced glycation end-product pyrraline via Maillard condensation
Authors: Kamalov Meder , Harris Paul W. R. , Wood James M. , Brimble Margaret A.
Published: May 2015

Pyrraline and a novel pyrraline-derived cross-link have been incorporated into collagenous peptides via Maillard condensations performed on resin-bound peptide sequences.
Electrifying the disk: a modular rotating platform for wireless power and data transmission for Lab on a disk application
Authors: Höfflin Jens , Torres Delgado Saraí M. , Suárez Sandoval Fralett , Korvink Jan G. , Mager Dario
Published: May 2015

We present a design for wireless power transfer, via inductively coupled coils, to a spinning disk. This is an important demonstration of what we believe will have numerous applications in the future.
Azetidine- and N-carboxylic azetidine-iminosugars as amyloglucosidase inhibitors: synthesis, glycosidase inhibitory activity and molecular docking studies
Authors: Gavale Kishor S. , Chavan Shrawan R. , Khan Ayesha , Joshi Rakesh , Dhavale Dilip D.
Published: May 2015

Azetidine and an unprecedentedN-carboxylic azetidine iminosugars were synthesized fromd-glucose, which showed prominent amyloglucosidase inhibitory activity.
Fabrication of multi-layered DNA nanostructures using single-strand and double-crossover tile connectors
Authors: Tandon Anshula , Mitta Sekhar Babu , Vellampatti Srivithya , Kim Byeonghoon , Lee Junwye , Kim Soyeon , Son Junyoung , Park Sung Ha
Published: May 2015

We demonstrated the sequential fabrication of multi-layered DNA nanostructures by single-strand and double-crossover tile connectors via substrate-assisted and multi-step annealings.
The effect of precursor types on the magnetic properties of Y-type hexa-ferrite composite
Authors: Kim Chin Mo , Na Eunhye , Kim Ingyu , An Sung Yong , Seo Jung-wook , Hur Kangheon , Kim Hakkwan
Published: May 2015

With magnetic composite including uniform magnetic particles, we expect to realize good high-frequency soft magnetic properties. We produced needle-like (α-FeOOH) nanoparticles with nearly uniform diameter and length of 20 and 500 nm. Zn-doped Y-type hexa-ferrite samples were prepared by solid state reaction method using the uniform goethite and non-uniform hematite (Fe2O3) with size of <1 μm, respectively. The micrographs observed by scanning electron microscopy show that more uniform hexagonal plates are observed in ZYG-sample (Zn-doped Y-type hexa-ferrite prepared with non-uniform hematite) than in ZYH-sample (Zn-doped Y-type hexa-ferrite prepared with uniform goethite). The permeability (μ′) and loss tangent (δ) at 2 GHz are 2.31 and 0.07 in ZYG-sample and 2.0 and 0.07 in ZYH sample, respectively. We can observe that permeability and loss tangent are strongly related to the particle size and uniformity based on the nucleation, growth, and two magnetizing mechanisms: spin rotation and domain wall motion. The complex permeability spectra also can be numerically separated into spin rotational and domain wall resonance components.
p-GaAs(Cs,O)-photocathodes: Demarcation of domains of validity for practical models of the activation layer
Authors: Bakin V. V. , Toropetsky K. V. , Scheibler H. E. , Terekhov A. S. , Jones L. B. , Militsyn B. L. , Noakes T. C. Q.
Published: May 2015

The (Cs,O)-activation procedure for p-GaAs(Cs,O)-photocathodes was studied with the aim of demarcating the domains of validity for the two practical models of the (Cs,O)-activation layer: The dipole layer (DL) model and the heterojunction (HJ) model. To do this, the photocathode was activated far beyond the normal maximum of quantum efficiency, and several photocathode parameters were measured periodically during this process. In doing so, the data obtained enabled us to determine the domains of validity for the DL- and HJ-models, to define more precisely the characteristic parameters of the photocathode within both of these domains and thus to reveal the peculiarities of the influence of the (Cs,O)-layer on the photoelectron escape probability.
Vibronic coupling explains the ultrafast carotenoid-to-bacteriochlorophyll energy transfer in natural and artificial light harvesters
Authors: Perlík Václav , Seibt Joachim , Cranston Laura J. , Cogdell Richard J. , Lincoln Craig N. , Savolainen Janne , Šanda František , Mančal Tomáš , Hauer Jürgen
Published: May 2015

The initial energy transfer steps in photosynthesis occur on ultrafast timescales. We analyze the carotenoid to bacteriochlorophyll energy transfer in LH2 Marichromatium purpuratum as well as in an artificial light-harvesting dyad system by using transient grating and two-dimensional electronic spectroscopy with 10 fs time resolution. We find that Förster-type models reproduce the experimentally observed 60 fs transfer times, but overestimate coupling constants, which lead to a disagreement with both linear absorption and electronic 2D-spectra. We show that a vibronic model, which treats carotenoid vibrations on both electronic ground and excited states as part of the system’s Hamiltonian, reproduces all measured quantities. Importantly, the vibronic model presented here can explain the fast energy transfer rates with only moderate coupling constants, which are in agreement with structure based calculations. Counterintuitively, the vibrational levels on the carotenoid electronic ground state play the central role in the excited state population transfer to bacteriochlorophyll; resonance between the donor-acceptor energy gap and the vibrational ground state energies is the physical basis of the ultrafast energy transfer rates in these systems.
Linking structure to fragility in bulk metallic glass-forming liquids
Authors: Wei Shuai , Stolpe Moritz , Gross Oliver , Evenson Zach , Gallino Isabella , Hembree William , Bednarcik Jozef , Kruzic Jamie J. , Busch Ralf
Published: May 2015

Using in-situ synchrotron X-ray scattering, we show that the structural evolution of various bulk metallic glass-forming liquids can be quantitatively connected to their viscosity behavior in the supercooled liquid near Tg. The structural signature of fragility is identified as the temperature dependence of local dilatation on distinct key atomic length scales. A more fragile behavior results from a more pronounced thermally induced dilatation of the structure on a length scale of about 3 to 4 atomic diameters, coupled with shallower temperature dependence of structural changes in the nearest neighbor environment. These findings shed light on the structural origin of viscous slowdown during undercooling of bulk metallic glass-forming liquids and demonstrate the promise of predicting the properties of bulk metallic glasses from the atomic scale structure.
Temperature dependence of the cross section for the fragmentation of thymine via dissociative electron attachment
Authors: Kopyra Janina , Abdoul-Carime Hassan
Published: May 2015

Providing experimental values for absolute Dissociative Electron Attachment (DEA) cross sections for nucleobases at realistic biological conditions is a considerable challenge. In this work, we provide the temperature dependence of the cross section, σ, of the dehydrogenated thymine anion (T − H)− produced via DEA. Within the 393-443 K temperature range, it is observed that σ varies by one order of magnitude. By extrapolating to a temperature of 313 K, the relative DEA cross section for the production of the dehydrogenated thymine anion at an incident energy of 1 eV decreases by 2 orders of magnitude and the absolute value reaches approximately 6 × 10−19 cm2. These quantitative measurements provide a benchmark for theoretical prediction and also a contribution to a more accurate description of the effects of ionizing radiation on molecular medium.
Collision-induced Raman scattering by rare-gas atoms: The isotropic spectrum of Ne–Ne and its mean polarizability
Authors: Rachet Florent , Dixneuf Sophie , Chrysos Michael
Published: May 2015

We report the room-temperature isotropic collision-induced light scattering spectrum of Ne–Ne over a wide interval of Raman shifts, and we compare it with the only available experimental spectrum for that system as well as with spectra calculated quantum-mechanically with the employ of advanced ab initio-computed data for the incremental mean polarizability. The spectral range previously limited to 170 cm−1 is now extended to 485 cm−1 allowing us to successfully solve the inverse-scattering problem toward an analytic model for the mean polarizability that perfectly matches our measurements. We also report the depolarization ratio of the scattering process, lingering over the usefulness of this property for more stringent checks between the various polarizability models.
Dzyaloshinskii-Moriya domain wall resonance in ferromagnetic nanowires with a spin-transfer torque
Authors: Li Zai-Dong , Liu Fei , Li Qiu-Yan , He P. B.
Published: May 2015

We theoretically investigate the current-induced domain wall resonance in ferromagnetic nanowires with a Dzyaloshinskii-Moriya interaction. The adiabatic and nonadiabatic torques distort the wall's internal structure and exert a global pressure on the wall. An effective Newton's equation is obtained analytically for a domain wall moving in one-dimensional potential and subject to a viscous friction and a driving force. Our results demonstrate that the Dzyaloshinskii-Moriya interaction affects the critical current density for depinning the wall, resonance frequency, and amplitude.
Efficiency enhancement in solution-processed organic small molecule: Fullerene solar cells via solvent vapor annealing
Authors: Miao Jingsheng , Chen Hui , Liu Feng , Zhao Baofeng , Hu Lingyu , He Zhicai , Wu Hongbin
Published: May 2015

We report highly efficient small molecule solar cells (SMSCs) by using dichloromethane solvent vapor annealing method. The resulted devices delivered a power conversion efficiency (PCE) of 8.3%, which is among the highest in SMSCs. Comparing to the control devices, the short circuit current (Jsc), fill factor, and PCE of solvent vapor annealed devices are significantly improved. Summarizing the results of optical absorption, film morphology, and charge carrier transporting properties, we see that the enhanced structure order and reduced size of phase separation are major reasons for the improved device performances, establishing a solid structure-property relationship. The solvent vapor annealing method can thus be a useful method in device fabrication to enhance performances of SMSCs.
Magnetoelectric effect in shear-mode Pb(Zr,Ti)O3/NdFeB composite cantilever
Authors: Han Jinchi , Hu Jun , Wang Zhongxu , Wang Shan X. , He Jinliang
Published: May 2015

A magnetoelectric (ME) composite cantilever consisting of two shear-mode Pb(Zr,Ti)O3 unimorphs and a tip NdFeB permanent magnet has been demonstrated to exhibit strong ME coupling based on the superior d15 shear response of the piezoelectric phase. The static ME coefficient and the power density under resonance condition of the fabricated samples reach 300 mV/cm·Oe and 2.25 μW/cm3·Oe2, respectively, without demand for DC bias field, which make it outperform previous designs of shear-mode ME composites. These good properties of the ME composite cantilever promise its prospects as a miniature device for sensing, transducing, and energy harvesting applications.