Rewarding cooperation in social dilemmas

One of the most direct human mechanisms of promoting cooperation is rewarding it. We study the effect of sharing a reward among cooperators in the most stringent form of social dilemma. Thus, individuals confront a new dilemma: on the one hand, they may be inclined to choose the shared reward despite the possibility of being exploited by defectors; on the other hand, if too many players do that, cooperators will obtain a poor reward and defectors will outperform them. By appropriately tuning the amount to be shared we can cast a vast variety of scenarios, including traditional ones in the study of cooperation as well as more complex situations where unexpected behavior can occur. We provide a complete classification of the equilibria of the nplayer game as well as of the evolutionary dynamics. Beyond, we extend our analysis to a general class of public good games where competition among individuals with the same strategy exists

Effect of zinc intake on growth in infants: A meta-analysis

A systematic review and meta-analysis of available randomized controlled trials (RCTs) was conducted to evaluate the effect of zinc (Zn) intake on growth in infants. Out of 5500 studies identified through electronic searches and reference lists, 19 RCTs were selected after applying the exclusion/inclusion criteria. The influence of Zn intake on growth was considered in the overall meta-analysis. Other variables were also taken into account as possible effect modifiers: doses of Zn intake, intervention duration, nutritional status, and risk of bias. From each select growth study, final measures of weight, length, mid upper arm circumference (MUAC), head circumference, weight for age z-score (WAZ), length for age z-score (LAZ), and weight for length z-score (WLZ) were assessed. Pooled β and 95% confidence interval (CI) were calculated. Additionally, we carried out a sensitivity analysis. Zn intake was not associated with weight, length, MUAC, head circumference, and LAZ in the pooled analyses. However, Zn intake had a positive and statistically effect on WAZ (β = 0.06; 95%CI 0.02 to 0.10) and WLZ (β = 0.05; 95%CI 0.01 to 0.08). The dose–response relationship between Zn intake and these parameters indicated that a doubling of Zn intake increased WAZ and WLZ by approximately 4%. Substantial heterogeneity was present only in length analyses (I2 = 45%; p = 0.03). Zn intake was positively associated with length values at short time (four to 20 weeks) (β = 0.01; CI 95% 0 to 0.02) and at medium doses of Zn (4.1 to 8 mg/day) (β = 0.003; CI 95% 0 to 0.01). Nevertheless, the effect magnitude was small. Our results indicate that Zn intake increases growth parameters of infants. Nonetheless, interpretation of these results should be carefully considered

Actividad neurotóxica y cambios ultraestructurales en musculos causados por el veneno de la araña viuda marrón Latrodectus geometricus

Brown widow spider (Latrodectus geometricus) venom (BrWSV) produces few local lesions and intense systemic reactions such as cramps, harsh muscle pains, nausea, vomiting and hypertension. Approximately 16 protein bands under reducing conditions and ~ 14 bands under non-reducing conditions on a 12.5% sodium dodecyl sulfate-polyacrylamide gel electrophoresis were observed. Neurotoxic clinical manifestations were confirmed in vivo, while proteolytic activity was demonstrated on gelatine film. Severe ultrastructural damages in mice skeletal muscles were observed at 3, 6, 12 and 24 h postinjection with at total of 45 µg of venom protein. Infiltration of eosinophils and ruptures of the cellular membranes were observed in the muscles along with swelling of the nuclear cover and interruption of the collagen periodicity. Altered mitochondrias and autophage vacuoles, nuclear indentation and mitochondria without cristae, slight increment of intermyofibrillar and subsarcolemic spaces and myelinic figures formation were also observed. In the capillary, endothelial membrane unfolding into the lumen was noticed; along with myelinic figures compatible with a toxic myopathy. Swollen sarcotubular systems with lysis of membrane, intense mitochondria autophagia and areas without pinocytic vesicles were observed. Swollen mitochondria surrounded by necrotic areas, myofibrillar disorganization and big vacuolas of the sarcotubular system, degenerated mitochondrium with formation of myelinic figure was seen. Glycogenosomes with small particulate, muscle type glycogen was noticed. Autophagic vacuole (autophagolysosomes) and necrotic areas were also noticed. These damages may be due to interactive effects of the multifactorial action of venom components. However, Latrodectus geometricus venom molecules may also be utilized as neuro therapeutic tools, as they affect neuronal activities with high affinity and selectivity. To our knowledge, the present study is the first ultrastructural report in the literature of muscle injuries and neurological and proteolytic activities caused by BrWSV.El veneno de la araña viuda marrón (Latrodectus geometricus) produce pocas lesiones locales pero intensas reacciones sistémicas, tales como calambres, dolores musculares severos, nauseas, vómitos e hipertensión arterial. Se observaron ~ 16 bandas de proteina bajo condiciones reducidas y ~14 bandas bajo condiciones no reducidas en electroforesis en geles de poliacrilamida al 12.5%. Las manifestaciones neurotóxicas clínicas fueron confirmadas in vivo, mientras que la actividad proteolítica fue demostrada en una placa de gelatina. Los músculos de ratón se estudiaron durante las 3, 6, 12 y 24 horas después de ser inyectados con 45 µg de proteina de veneno. Los músculos fueron seriamente dañados por este veneno. Se demostró una infiltracción de células eosinofílicas y rupturas de membranas celulares en tejido muscular, al mismo tiempo un fuerte incremento de la membrana nuclear y una interrupción de la periodicidad del colágeno. Se observaron daños en la mitocondria y sin cristaes, vacuolas autofágicas e indentación nuclear. Se notó un aumento de la luz de los espacios intermiofibrilares y subsarcolemicos. En los capilares fue visible un desdoblamiento de la membrana endotelial hacia el lúmen vascular. Del mismo modo, fue visto un hinchamiento del sistema sarcotubular con lisis de las membranas; intensa autofagia de mitocondrias y áreas sin vesículas pinocíticas. Fue además observado, glucogenosomas con glucogeno particulado. Se observaron vacuolas autofágicas (autofagolisosomas) y áreas de necrosis. Estos daños podrían ser atribuídos a los efectos interactivos de una acción multifactorial de los componentes del veneno

The WHaD diagram: Classifying the ionizing source with one single emission line

The usual approach to classify the ionizing source using optical spectroscopy is based on the use of diagnostic diagrams that compares the relative strength of pairs of collisitional metallic lines (e.g., [O iii] and [N ii]) with respect to recombination hydrogen lines (e.g., H{\beta} and H{\alpha}). Despite of being accepted as the standard procedure, it present known problems, including confusion regimes and/or limitations related to the required signal-to-noise of the involved emission lines. These problems affect not only our intrinsic understanding of inter-stellar medium and its poroperties, but also fundamental galaxy properties, such as the star-formation rate and the oxygen abundance, and key questions just as the fraction of active galactic nuclei, among several others. We explore the existing alternatives in the literature to minimize the confusion among different ionizing sources and proposed a new simple diagram that uses the equivalent width and the velocity dispersion from one single emission line, H{\alpha}, to classify the ionizing sources. We use aperture limited and spatial resolved spectroscopic data in the nearby Universe (z{\sim}0.01) to demonstrate that the new diagram, that we called WHaD, segregates the different ionizing sources in a more efficient way that previously adopted procedures. A new set of regions are defined in this diagram to select betweeen different ionizing sources. The new proposed diagram is well placed to determine the ionizing source when only H{\alpha} is available, or when the signal-to-noise of the emission lines involved in the classical diagnostic diagrams (e.g., H{\beta}).Comment: 10 pages, 5 figures, accepted for publishing in A&

Evaluación preliminar técnica, económica e institucional para la implementación de un servicio de ferris en el Caribe Oriental

La Comisión Económica para América Latina y el Caribe (CEPAL), en el marco de una asistencia técnica a la Asociación de Estados del Caribe (AEC), realizó, entre otras actividades, un primer estudio sobre la posibilidad de lanzar una red regional de ferris, cuyos resultados se exponen en este documento. En la primera parte se presenta una evaluación técnica y económica del mercado del Caribe Oriental, incluidos cuatro países del continente (Colombia, Guyana, Suriname y Venezuela (República Bolivariana de)), en la que se identifican los flujos potenciales y las posibles rutas para la implementación de un plan piloto, y se propone la flota que se emplazaría y las necesidades de infraestructura. En la segunda parte se analiza la posible inclusión de la participación privada, en su versión de asociaciones público-privadas, para el financiamiento y la operación de dichas rutas en el Caribe, así como para el financiamiento y la operación de los puertos requeridos para ello. También se analizan casos similares exitosos de asociaciones público-privadas, de los cuales se pueden extraer elementos clave al momento de impulsar el proyecto de ferris para el Caribe.Introducción .-- I. Análisis técnico y económico para la propuesta de una red regional de ferris .-- II. Participación privada en el desarrollo de sistema de ferris en el Caribe

Exploring the Impact of Galactic Interactions and Mergers on the Central Star Formation of APEX/EDGE-CALIFA Galaxies

Galactic interactions and subsequent mergers are a paramount channel for galaxy evolution. In this work, we use the data from 236 star forming CALIFA galaxies with integrated molecular gas observations in their central region (approximately within an effective radius) -- from the APEX millimeter telescope and the CARMA millimeter telescope array. This sample includes isolated (126 galaxies) and interacting galaxies in different merging stages (110 galaxies; from pairs, merging and post-merger galaxies). We show that the impact of interactions and mergers in the center of galaxies is revealed as an increase in the fraction of molecular gas (compared to isolated galaxies). Furthermore, our results suggest that the change in star formation efficiency is the main driver for both an enhancement and/or suppression of the central star formation -- except in merging galaxies where the enhanced star formation appears to be driven by an increase of molecular gas. We suggest that gravitational torques due to the interaction and subsequent merger transport cold molecular gas inwards, increasing the gas fraction without necessarily increasing star formation.Comment: 3 Figures, 13 Pages. Accepted for publication in Ap

pyFIT3D and pyPipe3D -- The new version of the Integral Field Spectroscopy data analysis pipeline

We present a new version of the FIT3D and Pipe3D codes, two packages to derive properties of the stellar populations and the ionized emission lines from optical spectroscopy and integral field spectroscopy data respectively. The new codes have been fully transcribed to Python from the original Perl and C versions, modifying the algorithms when needed to make use of the unique capabilities of this language with the main goals of (1) respecting as much as possible the original philosophy of the algorithms, (2) maintaining a full compatibility with the original version in terms of the format of the required input and produced output files, and (3) improving the efficiency and accuracy of the algorithms, and solving known (and newly discovered) bugs. The complete package is freely distributed, with an available repository online. pyFIT3D and pyPipe3D are fully tested with data of the most recent IFS data surveys and compilations (e.g. CALIFA, MaNGA, SAMI and AMUSING++), and confronted with simulations. We describe here the code, its new implementation, its accuracy in recovering the parameters based on simulations, and a showcase of its implementation on a particular dataset.Comment: New Astronomy - 29 pages, 19 figures - Received on 7 Dec 2021 - Accepted for publication on 8 Jul 202

Effect of Defoliation Frequency on Forage Yield from Intensive Silvopastoral Systems Compared to a Monoculture Grassland

Livestock production in the tropical regions of the world faces serious constraints as a result of climate change. Monoculture based pastures require the use of large amounts of nitrogen fertilizers to sustain production throughout the year. In general terms, tropical grasses are of low quality and when consumed by ruminant species, contribute to the emission of greenhouse gases (methane, carbon dioxide and nitrous oxide) (Herrero et al. 2009; Place et al. 2009). The establishment of intensive silvopastoral systems (iSPS) with associated shrubs legumes and grasses can increase the yield and quality of forage as well as fixation and transfer of atmospheric nitrogen (N) (Murgueitio et al. 2011). Therefore, the costs of nitrogen fertilizers and the emissions of greenhouse gases under practical conditions can be reduced. The intensive silvopastoral system is a kind of agroforestal practice that it is environmentally friendly and at the same time improves productivity of livestock systems. However, several aspects of its management have not been fully evaluated. This is the case of the response to defoliation, which is an important management factor associated to the overall biomass productivity (Solorio 2005)

Detección de la mutación JAK2V617F en pacientes con sospecha clínica de neoplasia mieloproliferativa sin expresión leucémica. Estudio preliminar

Se define como neoplasia mieloproliferativa a la alteración clonal de la célula madre hematopoyética caracterizada por la proliferación de uno o más linajes celulares mieloides en la médula ósea. La policitemia vera, la mielofibrosis primaria y la trombocitemia esencial son las entidades sin expresión leucémica más frecuentes en este grupo. La mutación puntual en el gen Januskinase 2 conocida como JAK2V617F, es una lesión génica encontrada en estas patologías. El objetivo de este estudio preliminar fue determinar la presencia de la mutación JAK2V617F en pacientes con sospecha clínico-patológica de neoplasia mieloproliferativa sin expresión leucémica utilizando la técnica de ARMS-PCR en los Laboratorios de Hematopatología y Genética Molecular del Instituto de Investigaciones en Ciencias de la Salud. En el 64% de pacientes (9 de 14 muestras de sangre periférica) se detectó la mutación. Su presencia constituye un valor diagnóstico sub-clasificatorio, pronóstico y terapéutico, siendo la técnica empleada de fácil ejecución e interpretación, obteniéndose resultados satisfactorios