Cosmic reionization by primordial cosmic rays

After the so-called cosmic recombination, the expanding universe entered into a period of darkness since most of the matter was in a neutral state. About a billion years later, however, the intergalactic space was once again ionized. The process, known as the cosmic reionization, required the operation of mechanisms that are not well understood. Among other ionizing sources, Population III stars, mini-quasars, and X-ray emitting microquasars have been invoked. In this article we propose that primordial cosmic rays, accelerated at the termination points of the jets of the first microquasars, may have contributed to the reionization of the intergalactic space as well. For this we quantify the ionization power of cosmic rays (electrons and protons) in the primordial intergalactic medium using extensive particle cascade simulations. We establish that, depending on the fraction of electrons to protons accelerated in the microquasar jets, cosmic rays should have contributed to the reionization of the primordial intergalactic medium as much as X-rays from microquasar accretion disks. If the primordial magnetic field was of the order of $10^{-17}$ G, as some models suggest, cosmic rays had an important role in ionizing the neutral material far beyond the birth places of the first stars.Comment: 4 pages, 2 figures, accepted for publication as a letter to the editor in Astronomy and Astrophysic

Exploring Cosmic Rays Ionization Power

The latest generations of telescopes have revealed a rich sky at high and very high energies. The most abundant identified sources are active galactic nuclei, usually blazars. It has been established that the Extra-galactic Background Light (optical to infrared wavelengths) attenuates high-energy photons through pair production. The development of pair-photon cascades along the line of sight modiies the originally emitted spectrum and have a measurable impact onto the source extent and arriving time of the photons. These effects should be included in our interpretation of the observations in order to progress in the understanding of the physical origin of the emission. We follow the three-dimensional trajectories of such cascades through numerical simulations. We report here the status of our investigations regarding the gamma-ray propagation through a ∼ 100 Mpc scale. Thisindirect study of the background photon ields and the extra-galactic magnetic ield (EGMF) is an exciting aspect of what some authors already call gamma-ray cosmology.Fil: Tueros, Matias Jorge. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: del Valle, Maria Victoria. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Romero, Gustavo Esteban. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaSecond Argentinian-Brazilian Meeting Gravitation, Astrophysics, and CosmologyBuenos AiresArgentinaInstituto de Astronomía y Física del EspacioInstituto Argentino de Radioastronomí

Design of a low-cost electrical resistivity meter for near surface surveys

A programmable automated electrical resistivity meter was designed and constructed. The device was created to perform near surface studies, particularly for archaeogeophysical target characterization. Real field and laboratory model studies can be performed changing the current input of the device. The equipment consists of two independent devices, each one with its own microcontroller platform. They are interconnected through serial data transfer protocol. The first device, works as a resistivity meter where the ABMN electrode positions are programmed and permits the interaction with the user. The second one, connects the current and voltage channels to the programmed electrode positions. A physical model and field measurements were performed with different electrode configurations such as Dipole-Dipole, Werner-Schlumberger and Wenner γ112 in order to verify the performance of the automated electrical resistivity meter. The measurements give mean relative standard deviation values between 0.6% and 5.5% and data inversion convergence between 1.3% and 7.2%. Even though this open source and low cost electrical resistivity meter was design primarily for archaeogeophysical studies, it could be adapted to other geophysical issues such as contamination plumes detection and characterization, tunnel detection, etc.Fil: de la Vega, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Grupo de Geofísica Aplicada; ArgentinaFil: Bongiovanni, Maria Victoria Flavia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ingeniería. Laboratorio de Investigación Desarrollo y Transferencia - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Laboratorio de Investigación Desarrollo y Transferencia; ArgentinaFil: Grünhut Duenyas, Vivian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ingeniería. Laboratorio de Investigación Desarrollo y Transferencia - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Laboratorio de Investigación Desarrollo y Transferencia; Argentin

Biotechnological potential of Phospholipase D for Loxosceles antivenom development

Loxoscelism is one of the most important forms of araneism in South America. The Health Authorities from countries with the highest incidence and longer history in registering loxoscelism cases indicate that specific antivenom should be administered during the first hours after the accident, especially in the presence or at risk of the most severe clinical outcome. Current antivenoms are based on immunoglobulins or their fragments, obtained from plasma of hyperimmunized horses. Antivenom has been produced using the same traditional techniques for more than 120 years. Although the whole composition of the spider venom remains unknown, the discovery and biotechnological production of the phospholipase D enzymes represented a milestone for the knowledge of the physiopathology of envenomation and for the introduction of new innovative tools in antivenom production. The fact that this protein is a principal toxin of the venom opens the possibility of replacing the use of whole venom as an immunogen, an attractive alternative considering the laborious techniques and low yields associated with venom extraction. This challenge warrants technological innovation to facilitate production and obtain more effective antidotes. In this review, we compile the reported studies, examining the advances in the expression and application of phospholipase D as a new immunogen and how the new biotechnological tools have introduced some degree of innovation in this field.Fil: Fingermann, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Salud de la Nación. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud "Doctor Carlos G. Malbrán". Instituto Nacional de Producción de Biológicos; ArgentinaFil: de Roodt, Adolfo Rafael. Ministerio de Salud de la Nación. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud "Doctor Carlos G. Malbrán". Instituto Nacional de Producción de Biológicos; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Cascone, Osvaldo. Ministerio de Salud de la Nación. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud "Doctor Carlos G. Malbrán". Instituto Nacional de Producción de Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; ArgentinaFil: Miranda, Maria Victoria. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; Argentin

Historical consideration of the gender differences in intelligence measurements in the beginnings of the 20th century

El objetivo de este artículo es investigar las diferentes concepciones de la categoría inteligencia así como sus instrumentos de medición en relación a las diferencias entre hombres y mujeres en las primeras décadas del Siglo XX. La medición de la inteligencia fue un instrumento que sirvió para definir las posibilidades de adaptación de los individuos, bajo las consideraciones científicas de sus capacidades y el establecimiento de cierto orden que fuera útil para el progreso de la Nación. La mujer aparece señalada como un ser de menor inteligencia que el hombre y por ello debía ser sometida a actividades sin exigencias creadoras, similares a aquellas llevadas a cabo por los individuos con retraso mental. Debajo de esta discusión, yace la polémica sobre la predominancia del ambiente por sobre los factores heredados y constitutivos en términos no solo etiológicos, sino también respecto de las posibilidades de la educación como una forma de mejora del nivel de inteligencia de la población.The aim of this article is to investigate the different conceptions of intelligence and its measurement in relation to intellectual level of men and women in the first decades of the 20th century. Classification could predict the future adaptation to society of affected individuals considering the scientific consideration of their capabilities and establish some social order, useful for the progress of the nation. Women appear as having lower intelligence than men: therefore, should be subject to activities which did not require creativity or ideation, like those carried by individuals who suffered from mental retardation. Beneath this discussion, lies the controversy over the prevalence of environment over inherited traits; not only to establish etiological factors, but also because of the possibility to turn to education as a way of improving the level of intelligence of the entire population.Fil: Benitez, Sebastian Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Molinari, Victoria. Universidad de Buenos Aires. Facultad de Psicología. Instituto de Investigaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Lifetime glucocorticoid profiles in baleen of right whale calves: Potential relationships to chronic stress of repeated wounding by Kelp Gulls

Baleen tissue accumulates stress hormones (glucocorticoids, GC) as it grows, along with other adrenal, gonadal and thyroid hormones. The hormones are deposited in a linear fashion such that a single plate of baleen allows retrospective assessment and evaluation of long-term trends in the whales´ physiological condition. In whale calves, a single piece of baleen contains hormones deposited across the lifespan of the animal, with the tip of the baleen representing prenatally grown baleen. This suggests that baleen recovered from stranded carcasses of whale calves could be used to examine lifetime patterns of stress physiology. Here we report lifetime profiles of cortisol and corticosterone in baleen of a North Atlantic right whale ("NARW" - Eubalaena glacialis) calf that died from a vessel strike, as well as four southern right whale ("SRW" - Eubalaena australis) calves that were found dead with varying severity of chronic wounding from Kelp Gull (Larus dominicanus) attacks. In all five calves, prenatally grown baleen exhibited a distinctive profile of elevated glucocorticoids that declined shortly before birth, similar to GC profiles reported from baleen of pregnant females. After birth, GC profiles in calf baleen corresponded with the degree of wounding. The NARW calf and two SRW calves with no or few gull wounds had relatively low and constant GC content throughout life, while two SRW calves with high numbers of gull wounds had pronounced elevations in baleen GC content in postnatal baleen followed by a precipitous decline shortly before death, a profile suggestive of prolonged chronic stress. Baleen samples may present a promising and valuable tool for defining the baseline physiology of whale calves and may prove useful for addressing conservation-relevant questions such as distinguishing acute from chronic stress and, potentially, determining cause of death.Fil: Ajó, Alejandro A. Fernández. Northern Arizona University; Estados UnidosFil: Hunt, Kathleen E.. Northern Arizona University; Estados UnidosFil: Uhart, Marcela María. University of California at Davis; Estados UnidosFil: Rowntree, Victoria. University of Utah; Estados UnidosFil: Sironi, Mariano. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica; Argentina. Instituto de Conservación de Ballenas; ArgentinaFil: Marón, Carina Flavia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica; Argentina. Instituto de Conservación de Ballenas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Martino, Matias. Southern Right Whale Health Monitoring Program; ArgentinaFil: Buck, Charles Loren. Northern Arizona University; Estados Unido

Intestinal parasitic infections in a community from Pampa del Indio, Chaco (Argentina) and their association with socioeconomic and environmental factors

Neglected tropical diseases are a group of 20 disabling diseases, which, in particular, are the most common chronic infections in the most vulnerable people. This study aimed to characterize the infection by intestinal parasites (IPs) in dwellings from a peri-urban neighborhood in Pampa del Indio, Chaco (Argentina), and its association with socioeconomic and environmental variables. Single stool samples were collected from all individuals older than 1 year through household visits and processed using coprological sedimentation and flotation techniques. Standardized questionnaires were used at the household level to collect socio-economic information. Environmental variables were obtained from the Planetscope image, Landsat 8 images and remote sensors, while land-use layers were obtained through the use of a maximum likelihood algorithm. Stool samples were provided by 314 individuals. The prevalence of IPs found was 30.6% (n = 96), with a predominance of Giardia lamblia (12.7%, n = 40) and Hymenolepis nana (7.6%, n = 24). The only soil-transmitted helminth found was Strongyloides stercoralis with a 2.5% prevalence (n = 8). Individuals of adult age (> 18 years) were 0.65 times less likely to present parasitic infections with respect to children and adolescents. The only environmental variable that was closely associated with the presence of IPs, was the Normalized Difference Water Index (NDWI), a measure of humidity; being higher around houses with positive individuals. Most of the IPs found in this study were of water-borne transmission and those transmitted directly from person-to-person, therefore fecal contamination is present. We believe that the low prevalence of STH in this area, which requires a passage through the soil, is related to the environmental characteristics, which are unsuitable for the development/permanence of the infective stages of these parasites. The geospatial data and tools used herein proved to be useful for the study of the relationship between the different factors that influence the presence of IPs in a community, from an eco-health approach.Fil: Scavuzzo, Carlos Matias. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Fundación Mundo Sano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Delgado, Cintia. Fundación Mundo Sano; ArgentinaFil: Goy, Marcia. Hospital Dr. Dante Tardelli; ArgentinaFil: Crudo, Favio. Fundación Mundo Sano; ArgentinaFil: Porcasi, Ximena. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; ArgentinaFil: Periago, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Mundo Sano; Argentin

Mandatory cost and other cost coming from the adoption of quality certifications in the hospitality business

The adaptation to the regulation of hospitality business implies a relevant cost in the profit and loss account. Additionally, some companies in this business decide to add some voluntary quality and environmental certification systems, which also yields to increased costs. The purpose of this paper is to quantify these costs and to analyse if the hotel size influences them. A total of 67 different costs were considered in hotels of all sizes, in the region of Catalonia as one of the most relevant touristic markets in Europe. Data were collected from the regulation applied to the hospitality sector, from specialised consultant companies and from a questionnaire supplied to 472 hotels in August and September 2008. The main results of this study show that the unitary cost by room, considering both, compulsory and voluntary costs, is lower in big hotels. On the other side, the smaller hotels are suffering high unitary costs. These results could be useful for the strategic orientation of hotels due to the relevance of costs to determine the competitive position of a firm. The main contribution of this work is to analyse the effects of compulsory costs and voluntary cost derived from the implementation of quality and environmental certifications in the hospitality sector, which could strongly affect the performance of this industry

Building Shape that Promotes Sustainable Architecture. Evaluation of the Indicative Factors and Its Relation with the Construction Costs

The energy that the building sector consume including both, the production and operation of buildings are directly proportional to the shape and the thermo-physical properties of the building envelope. The shapes that the architect decides on influences the costs of the construction as well as the energy demands for the life-cycle of the building. The present paper analyse four factors indicated by the bibliography to measure efficiency of the shape of the building. Theserelate different building variables: Envelope Area of Building (Ae), Conditioned Volume (Vc), Floor Area of Building (Ac), Perimeter of Building (Pb). The four factors studied are: Compactness Factor (Ae/Vc); Characteristic Length (Vc/Ae); Compactness Index (Pb/Pc) and Shape Factor (Ae/Ac). This paper also explores the relationship between the SF (shapefactor) and the cost of the construction of the building in relation to floor area, where a high degree of correlation is found, high R2 (<0.89). Therefore, it can be concluded that SF optimizes decisions concerning the shape of building in order to reach lower surface areas (compatible with an aesthetic, harmonic and functional design) that yield the lowest economic and energetic costs of construction.Fil: Esteves Miramont, Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ambiente, Hábitat y Energía; ArgentinaFil: Esteves, Matias Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Mercado, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ambiente, Hábitat y Energía; ArgentinaFil: Barea Paci, Gustavo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ambiente, Hábitat y Energía; ArgentinaFil: Gelardi, Daniel. Universidad de Mendoza. Instituto Para El Estudio del Medio Ambiente; Argentin

Enhanced LH action in transgenic female mice expressing hCGβ-subunit induces pituitary prolactinomas; the role of high progesterone levels

The etiology of pituitary adenomas remains largely unknown, with the exception of involvement of estrogens in the formation of prolactinomas. We have examined the molecular pathogenesis of prolactin-producing pituitary adenomas in transgenic female mice expressing the human choriongonadotropin (hCG) β-subunit. The LH/CG bioactivity is elevated in the mice, with consequent highly stimulated ovarian progesterone (P4) production, in the face of normal estrogen secretion. Curiously, despite normal estrogen levels, large prolactinomas developed in these mice, and we provide here several lines of evidence that the elevated P4 levels are involved in the growth of these estrogen-dependent tumors. The antiprogestin mifepristone inhibited tumor growth, and combined postgonadectomy estradiol/P4 treatment was more effective than estrogen alone in inducing tumor growth. Evidence for direct growth-promoting effect of P4 was obtained from cultures of primary mouse pituitary cells and rat somatomammotroph GH3 cells. The mouse tumors and cultured cells revealed stimulation of the cyclin D1/cyclin-dependent kinase 4/retinoblastoma protein/transcription factor E2F1 pathway in the growth response to P4. If extrapolated to humans, and given the importance of endogenous P4 and synthetic progestins in female reproductive functions and their pharmacotherapy, it is relevant to revisit the potential role of these hormones in the origin and growth of prolactinomas