Valence band offset of the ZnO/AlN heterojunction determined by X-ray photoemission spectroscopy

The valence band offset of ZnO/AlN heterojunctions is determined by high resolution x-ray photoemission spectroscopy. The valence band of ZnO is found to be 0.43±0.17 eV below that of AlN. Together with the resulting conduction band offset of 3.29±0.20 eV, this indicates that a type-II (staggered) band line up exists at the ZnO/AlN heterojunction. Using the III-nitride band offsets and the transitivity rule, the valence band offsets for ZnO/GaN and ZnO/InN heterojunctions are derived as 1.37 and 1.95 eV, respectively, significantly higher than the previously determined values

Estudio del comportamiento de dos cepas de Trypanosoma rangelí

ResumenSe estudiaron las cepas Choachi-2V y Durán del tripanosoma rangeli para obtener la mayor información posible acerca del comportamiento biológico de este parácito y su posible relación de protección contra infecciones por T. cruzi. La metaciclogénesis se determinó mediante recuento de las formas metaclínicas en un universo de 200 parásitos durante 5 días de seguimiento. Se produjo la infección, con cultivo axénico por vía intracelomica en grupos de 20 ninfas de quinto estadio de Rodnius prolixus, obteniéndose en hemolinfa y glándulas salivares las diferentes formas del ciclo del parásito incluyendo las metacíclicas infectivas, las cuales fueron inoculadas por vía intraperitoneal a ratones los cuales se les hizo seguimiento de parasitemias por observación en gota de sangre cada 48 horas durante 20 días.Palabras clave: Trypanosoma rangeli; Rhodnius, hemolinfa, glándulas salivares, isoenzimas, cultivo axénico, metaciclogénesis

Experimental observation of strong light-matter coupling in ZnO microcavities: influence of large excitonic absorption

We present experimental observation of the strong light-matter coupling regime in ZnO bulk microcavities grown on silicon. Angle resolved reflectivity measurements, corroborated by transfer-matrix simulations, show that Rabi splittings in the order of 70 meV are achieved even for low finesse cavities. The impact of the large excitonic absorption, which enables a ZnO bulk-like behavior to be observed even in the strong coupling regime, is illustrated both experimentally and theoretically by considering cavities with increasing thickness

Dietary Intervention Modulates the Expression of Splicing Machinery in Cardiovascular Patients at High Risk of Type 2 Diabetes Development: From the CORDIOPREV Study

Type-2 diabetes mellitus (T2DM) has become a major health problem worldwide. T2DM risk can be reduced with healthy dietary interventions, but the precise molecular underpinnings behind this association are still incompletely understood. We recently discovered that the expression profile of the splicing machinery is associated with the risk of T2DM development. Thus, the aim of this work was to evaluate the influence of 3-year dietary intervention in the expression pattern of the splicing machinery components in peripheral blood mononuclear cells (PBMCs) from patients within the CORDIOPREV study. Expression of splicing machinery components was determined in PBMCs, at baseline and after 3 years of follow-up, from all patients who developed T2DM (Incident-T2DM, n = 107) and 108 randomly selected non-T2DM subjects, who were randomly enrolled in two healthy dietary patterns (Mediterranean or low-fat diets). Dietary intervention modulated the expression of key splicing machinery components (i.e., up-regulation of SPFQ/RMB45/RNU6, etc., down-regulation of RNU2/SRSF6) after three years, independently of the type of healthy diet. Some of these changes (SPFQ/RMB45/SRSF6) were associated with key clinical features and were differentially induced in Incident-T2DM patients and non-T2DM subjects. This study reveals that splicing machinery can be modulated by long-term dietary intervention, and could become a valuable tool to screen the progression of T2DM

Helminth-induced arginase-1 exacerbates lung inflammation and disease severity in tuberculosis

Parasitic helminth worms, such as Schistosoma mansoni, are endemic in regions with a high prevalence of tuberculosis (TB) among the population. Human studies suggest that helminth coinfections contribute to increased TB susceptibility and increased rates of TB reactivation. Prevailing models suggest that T helper type 2 (Th2) responses induced by helminth infection impair Th1 immune responses and thereby limit Mycobacterium tuberculosis (Mtb) control. Using a pulmonary mouse model of Mtb infection, we demonstrated that S. mansoni coinfection or immunization with S. mansoni egg antigens can reversibly impair Mtb-specific T cell responses without affecting macrophage-mediated Mtb control. Instead, S. mansoni infection resulted in accumulation of high arginase-1–expressing macrophages in the lung, which formed type 2 granulomas and exacerbated inflammation in Mtb-infected mice. Treatment of coinfected animals with an antihelminthic improved Mtb-specific Th1 responses and reduced disease severity. In a genetically diverse mouse population infected with Mtb, enhanced arginase-1 activity was associated with increased lung inflammation. Moreover, in patients with pulmonary TB, lung damage correlated with increased serum activity of arginase-1, which was elevated in TB patients coinfected with helminths. Together, our data indicate that helminth coinfection induces arginase-1–expressing type 2 granulomas, thereby increasing inflammation and TB disease severity. These results also provide insight into the mechanisms by which helminth coinfections drive increased susceptibility, disease progression, and severity in TB

Uso de bebederos artificiales por el sereque centroamericano (Dasyprocta punctata) en la reserva de la biosfera de Calakmul, México

Objective: To describe the use of artificial drinking fountains by the central American Agouti (Dasyprocta punctata) in the Calakmul Biosphere Reserve. Design/methodology/approach: Eight artificial drinking fountains were monitored each one with a trap camera with the aim to estimate the relative abundance index and activity patterns of visits to the drinking fountains. The monitoring was during the dry season of 2019. The analyzes were carried out with the InfoStat and R programs. Results: From January to May 2019, with a sampling effort of 1121 days/camera, average abundance of 160.08±85.44. The pattern of visits to the drinking troughs was mainly diurnal. Limitations of the study/implications: The use of trap cameras in the artificial drinking fountains allows us to know the extent of habitat modification in the Calakmul Biosphere Reserve. Findings/conclusions: The implementation of artificial drinking fountains in the RBC during the dry season was a successful action to mitigate the effects of water scarcity. The use of the water resource by the Central American Agouti in artificial drinking fountains was constant, other species of mammals and birds were also observed making use of artificial drinking fountains.Objetivo: Describir el uso de bebederos artificiales por el sereque (Dasyprocta punctata) en la Reserva de la Biosfera de Calakmul. Diseño/metodología/aproximación: Se monitorearon ocho bebederos artificiales cada uno con una cámara trampa con la finalidad de estimar el índice de abundancia relativa y los patrones de actividad de visitas a los bebederos. El monitoreo fue durante la temporada de secas del 2019. Los análisis se realizaron con los programas R e InfoStat. Resultado: De enero a mayo de 2019, con un esfuerzo de muestreo fue de 1121 días/cámara, abundancia promedio de 160.08±85.44. El patrón de visitas a los bebederos fue principalmente diurno. Limitaciones/implicaciones: El uso de cámaras trampa en los bebederos artificiales nos permite conocer los alcances en la modificación del hábitat en la Reserva de la Biosfera de Calakmul (RBC). Hallazgos/conclusiones: La implementación de bebederos artificiales en la RBC durante la temporada de seca fue una acción de éxito para mitigar los efectos de la escases de agua. El aprovechamiento del recurso agua por el sereque en los bebederos artificiales fue constante, también se observaron otras especies de mamíferos y aves haciendo uso de los bebederos artificiales

Registro fotográfico de un murciélago capturado por Leopardus pardalis (Carnivora: Felidae) en la Reserva de la Biosfera de Calakmul, México

The ocelot faces conservation problems throughout its distribution, mainly due to illegal hunting and habitat transformation. It has been documented that the ocelot diet consists mainly of small nocturnal terrestrial mammals, especially rodents, although it has also been recorded that they can feed on possums, squirrels, rabbits, primates, iguanas, frogs, birds, fish, insects and terrestrial crabs.This note is relevant to the feeding behavior of ocelots in Mexico because it describes a photographic event of an ocelot feeding on a bat, the record was obtained with camera traps placed in the southern core zone of the Calakmul Biosphere Reserve. These cameras were installed to record that species of fauna visitrificiales drinkers (water sources constantly supplied by members of the project) that were placed as part of a pilot project in the years 2018 and 2019 and aim to supply water in the RBC for use of wildlife. As a result of this effort, this photographic record was obtained of an ocelot individual feeding on a bat associated with an artificial drinker.El ocelote enfrenta problemas de conservación a lo largo de su distribución, debido principalmente a la caza ilegal y transformación del hábitat. Se ha documentado que la dieta del ocelote consiste principalmente de pequeños mamíferos terrestres nocturnos, especialmente roedores , aunque también se ha registrado que pueden alimentarse de zarigüeyas, ardillas, conejos, primates, iguanas, ranas, aves, peces, insectos y cangrejos terrestres. La presente nota resulta relevante sobre el comportamiento alimentario de los ocelotes en Mexico debido a que se describe un evento fotográfico de un ocelote alimentándose de un murciélago, el registro fue obtenido con trampas cámara colocadas en la zona nucleo sur de la Reserva de la Biosfera de Calakmul . Estas camaras fueron instaladas para registrar que especies de fauna visitan a los bebederos ariticiales (fuentes de agua abastecidas constantemente por miembros del proyecto) que fueron colocados como parte de un proyecto piloto en los años 2018 y 2019 y tienen como objetivo el abastecimiento de agua en la RBC para uso de la fauna silvestre. Cómo resultado de este esfuerzo, se obtuvo el presente registro fotográfico de un individuo de ocelote alimentandose de un murcielago asociado a un bebedero artificial. &nbsp

Oxidative Stress Mediates Physiological Costs of Begging in Magpie (Pica pica) Nestlings

[Background] Theoretical models predict that a cost is necessary to guarantee honesty in begging displays given by offspring to solicit food from their parents. There is evidence for begging costs in the form of a reduced growth rate and immunocompetence. Moreover, begging implies vigorous physical activity and attentiveness, which should increase metabolism and thus the releasing of pro-oxidant substances. Consequently, we predict that soliciting offspring incur a cost in terms of oxidative stress, and growth rate and immune response (processes that generate pro-oxidants substances) are reduced in order to maintain oxidative balance. [Methodology/Principal Findings] We test whether magpie (Pica pica) nestlings incur a cost in terms of oxidative stress when experimentally forced to beg intensively, and whether oxidative balance is maintained by reducing growth rate and immune response. Our results show that begging provokes oxidative stress, and that nestlings begging for longer bouts reduce growth and immune response, thereby maintaining their oxidative status. [Conclusions/Significance] These findings help explaining the physiological link between begging and its associated growth and immunocompetence costs, which seems to be mediated by oxidative stress. Our study is a unique example of the complex relationships between the intensity of a communicative display (begging), oxidative stress, and life-history traits directly linked to viability.GM-R was supported by the Spanish Government (Ministerio de Ciencia y Tecnología, “Juan de la Cierva” program), and TR was supported by the Consejo Superior de Investigaciones Científicas (CSIC; Proyectos Intramurales Especiales)

A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000