CHANG-ES VI: Probing Supernova Energy Deposition in Spiral Galaxies Through Multi-Wavelength Relationships

How a galaxy regulates its SNe energy into different interstellar/circumgalactic medium components strongly affects galaxy evolution. Based on the JVLA D-configuration C- (6 GHz) and L-band (1.6 GHz) continuum observations, we perform statistical analysis comparing multi-wavelength properties of the CHANG-ES galaxies. The high-quality JVLA data and edge-on orientation enable us for the first time to include the halo into the energy budget for a complete radio-flux-limited sample. We find tight correlations of $L_{\rm radio}$ with the mid-IR-based SFR. The normalization of our $I_{\rm 1.6GHz}/{\rm W~Hz^{-1}}-{\rm SFR}$ relation is $\sim$2-3 times of those obtained for face-on galaxies, probably a result of enhanced IR extinction at high inclination. We also find tight correlations between $L_{\rm radio}$ and the SNe energy injection rate $\dot{E}_{\rm SN(Ia+CC)}$, indicating the energy loss via synchrotron radio continuum accounts for $\sim0.1\%$ of $\dot{E}_{\rm SN}$, comparable to the energy contained in CR electrons. The integrated C-to-L-band spectral index is $\alpha\sim0.5-1.1$ for non-AGN galaxies, indicating a dominance by the diffuse synchrotron component. The low-scatter $L_{\rm radio}-{\rm SFR}$/$L_{\rm radio}-\dot{E}_{\rm SN (Ia+CC)}$ relationships have super-linear logarithmic slopes at $\sim2~\sigma$ in L-band ($1.132\pm0.067$/$1.175\pm0.102$) while consistent with linear in C-band ($1.057\pm0.075$/$1.100\pm0.123$). The super-linearity could be naturally reproduced with non-calorimeter models for galaxy disks. Using Chandra halo X-ray measurements, we find sub-linear $L_{\rm X}-L_{\rm radio}$ relations. These results indicate that the observed radio halo of a starburst galaxy is close to electron calorimeter, and a galaxy with higher SFR tends to distribute an increased fraction of SNe energy into radio emission (than X-ray).Comment: 16 pages, 6 figures, 1 table, MNRAS in pres

New density estimates of a threatened sifaka species (Propithecus coquereli) in Ankarafantsika National Park

Propithecus coquereli is one of the last sifaka species for which no reliable and extensive density estimates are yet available. Despite its endangered conservation status [IUCN, 2012] and recognition as a flagship species of the northwestern dry forests of Madagascar, its population in its last main refugium, the Ankarafantsika National Park (ANP), is still poorly known. Using line transect distance sampling surveys we estimated population density and abundance in the ANP. Furthermore, we investigated the effects of road, forest edge, river proximity and group size on sighting frequencies, and density estimates. We provide here the first population density estimates throughout the ANP. We found that density varied greatly among surveyed sites (from 5 to ∼100 ind/km2) which could result from significant (negative) effects of road, and forest edge, and/or a (positive) effect of river proximity. Our results also suggest that the population size may be ∼47,000 individuals in the ANP, hinting that the population likely underwent a strong decline in some parts of the Park in recent decades, possibly caused by habitat loss from fires and charcoal production and by poaching. We suggest community-based conservation actions for the largest remaining population of Coquerel's sifaka which will (i) maintain forest connectivity; (ii) implement alternatives to deforestation through charcoal production, logging, and grass fires; (iii) reduce poaching; and (iv) enable long-term monitoring of the population in collaboration with local authorities and researchers.Optimus!Alive- IGC fellowship, FCT fellowship: (SFRH/BD/64875/2009), University of Mahajanga, Groupement de Recherche International (GDRI), "Laboratoire d'Excellence" (LABEX) entitled TULIP (ANR-10-LABX-41), the Rufford Small Grant Foundation grant: (10941-1)

El Proyecto de Ley 222 sobre el bienestar animal: retos y oportunidades para el cuidado del animal de laboratorio

This article reviews the treatment of research with laboratory animals as contained in Draft Legislation 222 of the Colombian Senate. The bill is compared with international norms, such as the iclas guidelines, the ets 123 of the European Union and the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. Finally, the main limitations of the bill are addressed.El presente artículo revisa el tratamiento de la investigación con animales de laboratorio tal y como figuran en el Proyecto de Ley 222 del Senado de la República de Colombia. Se compara este proyecto de ley con normativas internacionales, tales como los lineamientos del International Council for Laboratory Animal Science (iclas), el ets 123 de la Unión Europea y la Guía para el Cuidado y Uso de Animales de Laboratorio del Instituto Norteamericano de Salud. Finalmente, se discuten las principales limitaciones del Proyecto de Ley

A new model of Hantaan virus persistence in mice: the balance between HTNV infection and CD8+ T-cell responses

AbstractWe established a viral persistence model that involves the adoptive transfer of spleen cells from immunocompetent mice (H-2d) into Hantaan virus (HTNV)-infected severe combined immunodeficient (SCID, H-2d) mice. The infection is maintained despite the presence of neutralizing antibodies, without apparent signs of disease, and there is a correlation between HTNV persistence and the lack of HTNV-specific CD8+ T cells. In addition, disseminated HTNV infection before the initiation of immune responses appears to be important for virus persistence. The suppression of HTNV-specific CD8+ T cells in the present model appears to occur at the periphery. The present study also demonstrates that CD8+ T cells contribute to the clearance of HTNV. Thus, it seems that HTNV-specific CD8+ T cells play a key role in HTNV persistence in mice. This model of viral persistence is useful for studies of immune responses and immunocytotherapy against viral infection

Properties of stellar generations in Globular Clusters and relations with global parameters

ABRIDGED) We revise the formation of Galactic GCs by adding the detailed chemical composition of their different stellar generations (from 1200 giants in 19 GCs) to their global parameters. We propose to identify as GCs those showing the Na-O anticorrelation, and we classify the GCs according to kinematics and location in the Galaxy in disk/bulge, inner, and outer halo. We find that the LF of GCs is fairly independent of their population, suggesting that it is imprinted by the formation mechanism, and only marginally affected by the ensuing evolution. We show that a large fraction of the primordial population should have been lost by the proto-GCs. The extremely low Al abundances found for the primordial population of massive GCs indicate a very fast enrichment process before the formation of the primordial population. We suggest a scenario for the formation of GCs including at least 3 main phases: i) the formation of a precursor population (likely due to the interaction of cosmological structures similar to those leading to dwarf spheroidals, but residing at smaller Rgc, with the early Galaxy or with other structures), ii) which triggers a large episode of star formation (the primordial population), and iii) the formation of the current GC, mainly within a cooling flow formed by the slow winds of a fraction of the primordial population. The precursor population is very effective in raising the metal content in massive and/or metal poor (mainly halo) clusters, while its role is minor in small and/or metal rich (mainly disk) ones. Finally, we use PCA and multivariate relations to study the phase of metal-enrichment from 1st to 2nd generation. Most of the chemical signatures of GCs may be ascribed to a few parameters, the most important being [Fe/H], mass, and age of the cluster, with the location within the Galaxy also playing some role.Comment: 24 pages (+2 pages of bibliography and 5 of Appendix), 19 figures, accepted for publication on Astronomy and Astrophysic

Low-resolution spectroscopy of main sequence stars belonging to 12 Galactic globular clusters. I. CH and CN band strength variations

Globular clusters show abundance variations for light elements that are not yet well understood. The preferred explanation involves a self-enrichment scenario, with two subsequent generations of stars. Observations of main sequence stars allow us to investigate the signature of this chemically processed material without the complicating effects of internal mixing. Our goal is to investigate the C-N anti-correlation with low-resolution spectroscopy of 20-50 stars fainter than the first dredge-up in seven globular clusters (NGC288, NGC1851, NGC5927, NGC6352, NGC6388, and Pal12) with different properties. We complemented our observations with 47~Tuc archival data, with four additional clusters from the literature (M15, M22, M55, NGC362), and with additional literature data on NGC288. In this first paper, we measured the strength of CN and CH band indices, and we investigated the anti-correlation and bimodality of these indices. We compared r_CN, the ratio of stars belonging to the CN-strong and weak groups, with 15 different cluster parameters. We clearly see bimodal anti-correlation of the CH and CN band stregths in the metal-rich clusters (Pal12, 47Tuc, NGC6352, NGC5927). Only M15 among the metal-poor clusters shows a clearly bimodal anti-correlation. We found weak correlations (sligthly above 1 sigma) of r_CN with the cluster orbital parameters, present-day total mass, cluster concentration, and age. Our findings support the self-enrichment scenario, and suggest that the occurrence of more than two major generations of stars in a GGC should be rare. Small additional generations (<10-20% of the total) would be difficult to detect with our samples. The first generation, which corresponds to the CN-weak stars, usually contains more stars than the second one (=0.82+/-0.29), as opposed to results based on the Na-O anti-correlations.Comment: 18 pages, 10 figures, 1 electronic table, accepted for publication in A&A (language edited version

Effect of sampling frequency on automatically-generated activity and freezing scores in a Pavlovian fear-conditioning preparation

La respuesta condicionada de congelamiento tiene importancia conceptual de larga data para el Análisis Conductual, siendo clave en la explicación de las conductas de ansiedad. Aún cuando inicialmente fue medida de forma indirecta, mediante sus efectos sobre la conducta operante (como en el arreglo de supresión condicionada) y más tarde mediante la observación directa, recientemente se han hecho disponibles alternativas para la medición automática del movimiento que permiten también la medición del congelamiento condicionado. Estas nuevas técnicas de video permiten la medición directa y virtualmente constante de la actividad del organismo, por contraposición a las técnicas tradicionales de muestreo de tiempo características del registro observacional. En el presente artículo se compara el efecto de manipulaciones pavlovianas tradicionales sobre la sensibilidad de los de los índices automatizados de congelamiento y actividad, así como el posible efecto de la densidad de muestreo sobre dicha sensibilidad. Para ello se analizan datos provenientes de sesiones de extinción pavloviana de 42 ratones, recogidos con una frecuencia 30 Hz y transformados mediante una técnica de remuestreo, para luego ser analizado mediante un modelo lineal generalizado, a fin de determinar la magnitud del efecto de la presencia del estímulo condicionado en cada una de cuatro condiciones: puntajes brutos de actividad de alta y baja resolución y puntajes dicotómicos de congelamiento de alta y baja resolución. La resolución de los datos mostró ser la dimensión más relevante para la estimación de cambios locales de nivel en las series temporales individuales, siendo dichos cambios igualmente fáciles de detectar en los índices de congelamiento y de actividad. A diferencia de lo anterior, sólo las medidas de actividad de alta resolución permitieron la detección de cambios locales de tendencia

Análisis intra - sesión de la extinción del condicionamiento Pavloviano de miedo usando regresión robusta

Traditionally , the analysis of extinction data in fear conditioning experiments has involved the use of standard linear models, mostly ANOVA of between-group differences of subjects that have undergone different extinction protocols, pharmacological manipulations or some other treatment. Although some studies report individual differences in quantities such as suppression rates or freezing percentages, these differences are not included in the statistical modeling. Withinsubject response patterns are then averaged using coarse-grain time windows which can overlook these individual performance dynamics. Here we illustrate an alternative analytical procedure consisting of 2 steps: the estimation of a trend for within-session data and analysis of group differences in trend as main outcome. This procedure is tested on real fear-conditioning extinction data, comparing trend estimates via Ordinary Least Squares (OLS) and robust Least Median of Squares (LMS) regression estimates, as well as comparing between-group differences and analyzing mean freezing percentage versus LMS slopes as outcomes.El an&aacute;lisis de datos de extinci&oacute;n en experimentos de miedo condicionado ha involucrado, tradicionalmente, el uso de modelos lineales est&aacute;ndar, primordialmente ANOVA de diferencias entre grupos de sujetos sometidos a diferentes protocolos de extinci&oacute;n, manipulaciones farmacol&oacute;gicas o alg&uacute;n otro tratamiento.A&uacute;n cuando algunos estudios reportan diferencias individuales en indicadores como tasas de supresi&oacute;n o porcentajes de congelamiento, esas diferencias no son incluidas en el an&aacute;lisis estad&iacute;stico. Los patrones de respuesta intra-sujeto son entonces promediados usando ventanas temporales de baja resoluci&oacute;n, las cuales pueden ignorar esta din&aacute;mica del desempe&ntilde;o individual. Este trabajo ilustra un procedimiento anal&iacute;tico alternativo que consta de 2 pasos: estimaci&oacute;n de la tendencia para los datos intra-sesi&oacute;n y el an&aacute;lisis de las diferencias entre-grupo usando la tendencia como variable de respuesta. Este procedimiento se pone a prueba usando datos reales de extinci&oacute;n de miedo condicionado, comparando estimaciones de tendencia robusta v&iacute;a M&iacute;nimos Cuadrados Medianos con M&iacute;nimos Cuadrados Ordinarios, y comparando las diferencias de grupo usando la pendiente robusta versus la mediana del porcentaje de congelamiento como variable dependiente

Activity in ventral premotor cortex is modulated by vision of own hand in action

Parietal and premotor cortices of the macaque monkey contain distinct populations of neurons which, in addition to their motor discharge, are also activated by visual stimulation. Among these visuomotor neurons, a population of grasping neurons located in the anterior intraparietal area (AIP) shows discharge modulation when the own hand is visible during object grasping. Given the dense connections between AIP and inferior frontal regions, we aimed at investigating whether two hand-related frontal areas, ventral premotor area F5 and primary motor cortex (area F1), contain neurons with similar properties. Two macaques were involved in a grasping task executed in various light/dark conditions in which the to-be-grasped object was kept visible by a dim retro-illumination. Approximately 62% of F5 and 55% of F1 motor neurons showed light/dark modulations. To better isolate the effect of hand-related visual input, we introduced two further conditions characterized by kinematic features similar to the dark condition. The scene was briefly illuminated (i) during hand preshaping (pre-touch flash, PT-flash) and (ii) at hand-object contact (touch flash, T-flash). Approximately 48% of F5 and 44% of F1 motor neurons showed a flash-related modulation. Considering flash-modulated neurons in the two flash conditions, ∼40% from F5 and ∼52% from F1 showed stronger activity in PT- than T-flash (PT-flash-dominant), whereas ∼60% from F5 and ∼48% from F1 showed stronger activity in T- than PT-flash (T-flash-dominant). Furthermore, F5, but not F1, flash-dominant neurons were characterized by a higher peak and mean discharge in the preferred flash condition as compared to light and dark conditions. Still considering F5, the distribution of the time of peak discharge was similar in light and preferred flash conditions. This study shows that the frontal cortex contains neurons, previously classified as motor neurons, which are sensitive to the observation of meaningful phases of the own grasping action. We conclude by discussing the possible functional role of these populations

Reach and grasp by people with tetraplegia using a neurally controlled robotic arm

Paralysis following spinal cord injury (SCI), brainstem stroke, amyotrophic lateral sclerosis (ALS) and other disorders can disconnect the brain from the body, eliminating the ability to carry out volitional movements. A neural interface system (NIS)1–5 could restore mobility and independence for people with paralysis by translating neuronal activity directly into control signals for assistive devices. We have previously shown that people with longstanding tetraplegia can use an NIS to move and click a computer cursor and to control physical devices6–8. Able-bodied monkeys have used an NIS to control a robotic arm9, but it is unknown whether people with profound upper extremity paralysis or limb loss could use cortical neuronal ensemble signals to direct useful arm actions. Here, we demonstrate the ability of two people with long-standing tetraplegia to use NIS-based control of a robotic arm to perform three-dimensional reach and grasp movements. Participants controlled the arm over a broad space without explicit training, using signals decoded from a small, local population of motor cortex (MI) neurons recorded from a 96-channel microelectrode array. One of the study participants, implanted with the sensor five years earlier, also used a robotic arm to drink coffee from a bottle. While robotic reach and grasp actions were not as fast or accurate as those of an able-bodied person, our results demonstrate the feasibility for people with tetraplegia, years after CNS injury, to recreate useful multidimensional control of complex devices directly from a small sample of neural signals