Magnetic-field control of near-field radiative heat transfer and the realization of highly tunable hyperbolic thermal emitters

We present a comprehensive theoretical study of the magnetic field dependence of the near-field radiative heat transfer (NFRHT) between two parallel plates. We show that when the plates are made of doped semiconductors, the near-field thermal radiation can be severely affected by the application of a static magnetic field. We find that irrespective of its direction, the presence of a magnetic field reduces the radiative heat conductance, and dramatic reductions up to 700% can be found with fields of about 6 T at room temperature. We show that this striking behavior is due to the fact that the magnetic field radically changes the nature of the NFRHT. The field not only affects the electromagnetic surface waves (both plasmons and phonon polaritons) that normally dominate the near-field radiation in doped semiconductors, but it also induces hyperbolic modes that progressively dominate the heat transfer as the field increases. In particular, we show that when the field is perpendicular to the plates, the semiconductors become ideal hyperbolic near-field emitters. More importantly, by changing the magnetic field, the system can be continuously tuned from a situation where the surface waves dominate the heat transfer to a situation where hyperbolic modes completely govern the near-field thermal radiation. We show that this high tunability can be achieved with accessible magnetic fields and very common materials like n-doped InSb or Si. Our study paves the way for an active control of NFRHT and it opens the possibility to study unique hyperbolic thermal emitters without the need to resort to complicated metamaterials.Comment: 21 pages, 10 figure

Diseño de competencias tecnico funcionales de planeamiento estrategico para mejorar la gestión institucional de la Municipalidad distrital de Motupe, 2016

El presente trabajo de investigación, por su alcance y objetivos establecidos, es de tipo sustantivo – descriptivo, de nivel propositivo, con un enfoque cuantitativo. En primera instancia describe la situación determinada en el periodo 2016, respecto a la problemática advertida en cuanto a la organización, comprensión y operatividad del sistema de planeamiento estratégico, y su importancia para el normal y adecuado desarrollo de la gestión institucional de la Municipalidad Distrital de Motupe, de la provincia y departamento de Lambayeque. En la fase siguiente, se ha comparado la realidad percibida y operacionalizado con las dimensiones teóricas científicas que fundamentan el proceso de planeamiento estratégico y su incidencia en la gestión institucional de los gobiernos locales. Configurándose ambas como las variables establecidas para la investigación. La población de la unidad de análisis ha estado constituida por la totalidad de los trabajadores administrativos permanentes de la entidad, que suman cincuenta y nueve (59). Así mismo, el cuestionario, la guía de entrevista, y la hoja de cotejo y análisis, se constituyeron en los instrumentos utilizados en el estudio. Finalmente, se exponen los resultados obtenidos con relación a cada una de las variables establecidas para el estudio, que han permitido advertir el nivel de organización y operatividad del sistema de planeamiento estratégico como una herramienta efectiva para el desarrollo de la gestión institucional. Así como, se plantea, a manera de propuesta, un conjunto de competencias técnico-funcionales en planeamiento estratégico para mejorar el desempeño de los trabajadores, y por ende la gestión estratégica institucional de la entidad

A molecular genetic perspective of reproductive development in grapevine

The grapevine reproductive cycle has a number of unique features. Inflorescences develop from lateral meristems (anlagen) in latent buds during spring and summer and enter a dormant state at a very immature stage before completing development and producing flowers and berries the following spring. Lateral meristems are unique structures derived from the shoot apical meristem and can either develop into an inflorescence or a tendril. How the grapevine plant controls these processes at the molecular level is not understood, but some progress has been made by isolating and studying the expression of flowering genes in wild-type and mutant grapevine plants. Interestingly, a number of flowering genes are also expressed during berry development. This paper reviews the current understanding of the genetic control of grapevine flowering and the impact of viticulture management treatments and environmental variables on yield. While the availability of the draft genome sequence of grapevine will greatly assist future molecular genetic studies, a number of issues are identified that need to be addressed—particularly rapid methods for confirming gene function and linking genes to biological processes and traits. Understanding the key interactions between environmental factors and genetic mechanisms controlling the induction and development of inflorescences, flowers, and berries is also an important area that requires increased emphasis, especially given the large seasonal fluctuations in yield experienced by the crop and the increasing concern about the effect of climate change on existing wine-producing regions

Relación entre clima organizacional y satisfacción laboral en trabajadores dependientes

La presente investigación aplicada tuvo como objetivo analizar la relación entre el clima organizacional y la satisfacción laboral en trabajadores dependientes por medio de una búsqueda sistemática en investigaciones que tratan ambas variables. Por ello, se consideraron 10 estudios publicados entre 2020 y 2024, extraídos de las bases de datos: Scopus, Scielo y ResearchGate, y seleccionados bajo criterios de inclusión y exclusión. Los resultados indican una relación positiva y significativa entre el clima organizacional y la satisfacción laboral. Se encontró que un entorno laboral favorable, caracterizado por apoyo organizacional, reconocimiento y comunicación efectiva, influye directamente en el bienestar y la motivación de los trabajadores. Además, se identificaron variables moderadoras y mediadoras, como el estrés ocupacional, el bienestar psicológico, la regulación emocional y la autoeficacia, que pueden modificar dicha relación. Se concluye que el clima organizacional desempeña un papel clave en la satisfacción laboral y que su adecuada gestión con estrategias como programas de bienestar y reconocimiento, contribuye a mejorar el compromiso y la productividad de los colaboradores dentro de las organizaciones.The objective of this paper was to analyze the relationship between the organizational climate and job satisfaction in dependent workers through a systematic search in research that deals with both variables. For this reason, 10 studies published between 2020 and 2024 were considered, extracted from the databases: Scopus, Scielo and ResearchGate, and selected under inclusion and exclusion criteria. The results indicate a positive and significant relationship between organizational climate and job satisfaction. It was found that a favorable work environment, characterized by organizational support, recognition and effective communication, directly influences the well-being and motivation of workers. In addition, moderating and mediating variables were identified, such as occupational stress, psychological well-being, emotional regulation and self-efficacy, which can modify this relationship. It is concluded that the organizational climate plays a key role in job satisfaction and that its proper management with strategies such as well-being and recognition programs, contributes to improving the commitment and productivity of employees within organizations

Sodium signaling and astrocyte energy metabolism.

The Na(+) gradient across the plasma membrane is constantly exploited by astrocytes as a secondary energy source to regulate the intracellular and extracellular milieu, and discard waste products. One of the most prominent roles of astrocytes in the brain is the Na(+) -dependent clearance of glutamate released by neurons during synaptic transmission. The intracellular Na(+) load collectively generated by these processes converges at the Na,K-ATPase pump, responsible for Na(+) extrusion from the cell, which is achieved at the expense of cellular ATP. These processes represent pivotal mechanisms enabling astrocytes to increase the local availability of metabolic substrates in response to neuronal activity. This review presents basic principles linking the intracellular handling of Na(+) following activity-related transmembrane fluxes in astrocytes and the energy metabolic pathways involved. We propose a role of Na(+) as an energy currency and as a mediator of metabolic signals in the context of neuron-glia interactions. We further discuss the possible impact of the astrocytic syncytium for the distribution and coordination of the metabolic response, and the compartmentation of these processes in cellular microdomains and subcellular organelles. Finally, we illustrate future avenues of investigation into signaling mechanisms aimed at bridging the gap between Na(+) and the metabolic machinery. GLIA 2016;64:1667-1676

"Evaluación superficial empleando el método PCI y VIZIR del pavimento flexible en la Ruta LI-1225 Km: 0+000 al 3+000, Guadalupito-Virú-La Libertad, 2022"

El objetivo del presente trabajo investigación fue determinar la condición del pavimento flexible en base a los estándares normativos empleando el Método PCI y VIZIR en la Ruta LI-1225 Km: 0+000 al 3+000, Guadalupito – Virú - La Libertad, 2022. Para ello se realizó una inspección visual en campo, estudios de suelos y estudio de tráfico. El tipo de investigación según su finalidad es Aplicada, según su nivel es explicativo causal y según su enfoque es cuantitativo. La información fue ordenada y colocada en fichas observacionales para ambos métodos y como resultado Concluyendo que para el método PCI se obtuvo un valor de 37.84 obteniendo una clasificación de condición de pavimento MALO; con respecto al método VIZIR se obtuvo un 56% en estado regular con un rango de clasificación N°3. Llegando a la conclusión que el método PCI logra detallar de forma detallada y precisa la condición del pavimento a diferencia del método VIZIR

Evaluating social choice techniques into intelligent environments by agent based social simulation

The primary hypothesis stated by this paper is that the use of social choice theory in Ambient Intelligence systems can improve significantly users satisfaction when accessing shared resources. A research methodology based on agent based social simulations is employed to support this hypothesis and to evaluate these benefits. The result is a six-fold contribution summarized as follows. Firstly, several considerable differences between this application case and the most prominent social choice application, political elections, have been found and described. Secondly, given these differences, a number of metrics to evaluate different voting systems in this scope have been proposed and formalized. Thirdly, given the presented application and the metrics proposed, the performance of a number of well known electoral systems is compared. Fourthly, as a result of the performance study, a novel voting algorithm capable of obtaining the best balance between the metrics reviewed is introduced. Fifthly, to improve the social welfare in the experiments, the voting methods are combined with cluster analysis techniques. Finally, the article is complemented by a free and open-source tool, VoteSim, which ensures not only the reproducibility of the experimental results presented, but also allows the interested reader to adapt the case study presented to different environments

Annu Rev Physiol

Information processing imposes urgent metabolic demands on neurons, which have negligible energy stores and restricted access to fuel. Here, we discuss metabolic recruitment, the tissue-level phenomenon whereby active neurons harvest resources from their surroundings. The primary event is the neuronal release of K+ that mirrors workload. Astrocytes sense K+ in exquisite fashion thanks to their unique coexpression of NBCe1 and α2β2 Na+/K+ ATPase, and within seconds switch to Crabtree metabolism, involving GLUT1, aerobic glycolysis, transient suppression of mitochondrial respiration, and lactate export. The lactate surge serves as a secondary recruiter by inhibiting glucose consumption in distant cells. Additional recruiters are glutamate, nitric oxide, and ammonium, which signal over different spatiotemporal domains. The net outcome of these events is that more glucose, lactate, and oxygen are made available. Metabolic recruitment works alongside neurovascular coupling and various averaging strategies to support the inordinate dynamic range of individual neurons. Copyright © 2023 by the author(s)

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Decrecimiento de Streptococcus mutans después de la aplicación de sellantes en superficies oclusales de molares permanentes en adultos

Introduction: The main strategy for the prevention of caries disease is the use of pit and fissure sealants, which are indicated for posterior occlusal surfaces that are difficult to clean and cannot be protected very well by fluoride. This strategy is considered to be very important in caries prevention, especially in patients at high cariogenic risk.Objective: Evaluate whether the count of colony forming units of S. mutans per cm2 on the occlusal surface of posterior permanent teeth changes after applying resin-based sealant.Methods: A study was conducted of 38 patients of both genders aged 18-30 years. The patients were at high cariogenic risk and had an indication of occlusal sealant application on at least one permanent posterior tooth. Two samples were taken of dental biofilm from the same teeth before (group T0) and after (group T1) applying sealant obtained by direct impression by tray technique with trypticase yeast extract, cysteine, sucrose with bacitracin (TYCSB), and agar previously made and solidified. The samples were incubated at 37 ºC for 48 hours. The colony forming units (CFU/cm2) were counted. The results were statistically analyzed with the Wilcoxon test at 95 % confidence.Results: Average expression in CFU/cm2 before applying the sealant (T0) and standard deviation was 13.48 (± 14.2), whereas after applying the sealant (T1) it was 5.37 (± 8.90). There was a statistical difference between the two measures T0 and T1 (p< 0.05).Conclusions: Sealant application on occlusal surfaces of posterior permanent teeth significantly reduces the count of CFU/cm2 of S. mutans.Introducción: La estrategia principal para la prevención de la enfermedad de caries es el uso de selladores de fosas y fisuras, que están indicados para las superficies oclusales posteriores que son difíciles de limpiar y no se pueden proteger muy bien con fluoruro. Esta estrategia se considera muy importante en la prevención de caries, especialmente en pacientes con alto riesgo cariogénico.Objetivo: Evaluar si el recuento de unidades formadoras de colonias de S. mutans por cm2 en la superficie oclusal de los dientes permanentes posteriores cambia después de aplicar un sellador a base de resina.Métodos: Se seleccionaron 38 pacientes con alto riesgo cariogénico, de ambos sexos entre 18 y 30 años de edad, con al menos un diente posterior permanente con una indicación de sellador oclusal. Se tomaron dos muestras de biofilm dental de los mismos dientes antes (grupo T0) y después (grupo T1) de aplicar sellador obtenido con una técnica de impresión directa por bandeja con extracto de levadura de tripticasa, cisteína, sacarosa con bacitracina (TYCSB), agar previamente preparado y solidificado, y se incubaron a 37 ºC durante 48 horas. Se contaron las unidades formadoras de colonias (UFC/cm2). Los resultados se analizaron estadísticamente mediante la prueba de Wilcoxon con una confianza del 95 %.Resultados: El promedio de expresión en UFC/cm2 antes de aplicar el sellador (T0) y la desviación estándar fue de 13,48 (± 14,2), y después de aplicar el sellador (T1) fue de 5,37 (± 8,90). Hubo una diferencia estadística entre las dos medidas T0 y T1 (p< 0,05).Conclusiones: La aplicación de sellador en las superficies oclusales de los dientes permanentes posteriores reduce significativamente el recuento de UFC/cm2 de S. mutans