176 research outputs found

    Análisis dogmático del derecho penal ambiental chileno, a la luz del derecho comparado y las obligaciones contraídas por Chile en el ámbito del derecho internacional. Conclusiones y propuesta legislativa

    Get PDF
    Indexación: ScieloEl presente artículo corresponde al Informe Final del Proyecto FONDECYT 1010206­2001, sobre tratamiento penal de los delitos contra el medio ambiente en Chile. Sus conclusiones se exponen en siete partes: la primera aborda la cuestión de la necesidad de un derecho penal protector del medio ambiente, ante los riesgos a que se encuentra sometido en las sociedades contemporáneas; la segunda, la necesidad de su regulación desde el punto de vista del Derecho Internacional y las obligaciones contraídas en la materia; la tercera, una descripción sucinta de los modelos de regulación de la protección penal del medio ambiente en el derecho comparado; la cuarta, una explicación acerca de las normas de derecho penal ambiental vigentes en Chile; la quinta, el por qué de la insuficiencia legislativa penal para la protección del medio ambiente, a la luz de las obligaciones internacionales contraídas en la materia, el estado del derecho comparado y la necesidad de evitar la burla del Sistema de Evaluación de Impacto Ambiental; la sexta, una reseña y crítica científica de los proyectos de ley en materia penal ambiental presentados al Congreso Nacional; y la séptima, las ideas matrices de las soluciones de lege ferenda que se ofrecen a los problemas de las insuficiencias del Derecho nacional en la materia y el texto de la propuesta de Proyecto de Ley elaborado, producto final de nuestras investigaciones.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-00122003000200002&nrm=is

    The effect of sintering temperature on the properties of the BiOCl films for potential application in DSSC

    Get PDF
    In this work, BiOCl films were obtained by tape casting using BiOCl powders synthesized by the co-precipitation method. The effect of the film's sintering temperature (300 °C–600 °C) on the morphology, chemical composition, crystalline phases and optical characteristics was studied. The obtained BiOCl powders showed a flake-like morphology, a tetragonal crystalline structure without secondary phases and a wide band gap of 3.53 eV. For BiOCl films, results indicated that as the sintering temperature increased the flake-like shaped particles changed to rectangular ones while the amount of chlorine in the films decreased. A phase transition from tetragonal BiOCl to monoclinic Bi24O31Cl10 was also observed as the sintering temperature increased. Consequently, optical studies revealed that the band gap of BiOCl films decreased from 3.03 eV to 2.82 eV. FTIR analysis demonstrated that the organic groups were removed from the films only for sintering temperatures above 400 °C. The Rhodamine B dye adsorption capacity of BiOCl films decreased with increasing sintering temperature. The results obtained allow us to conclude that BiOCl films are suitable for use in DSSC when the sintering temperature is in the range of 400–500 °C

    DIVERSIDAD DE AVES DE SOTOBOSQUE EN BOSQUES TROPICALES, ÁREAS DE REGENERACIÓN NATURAL Y CULTIVOS DE PALMA AFRICANA EN HUMEDALES DEL LAGO DE IZABAL, GUATEMALA

    Get PDF
    Diversity of understory birds in tropical forests, natural recovery areas, and African oil palm crops in wetlands of the Izabal Lake, Guatemala. – African oil palm (Elaeis guineensis) crops have been identified as one of the most important threats to biodiversity of tropical forests. By mean of mist nets, species richness, diversity and structure of understory bird communities were studied in three vegetation types of a Neotropical wetland: humid tropical forest remnants, natural regeneration sites (“guamiles”), and African oil palm plantations. We captured a total of 734 birds of 106 species, belonging to 22 families. The habitat with highest diversity was forest (63 species and 329 individuals), followed by guamiles (62 species and 368 individuals) and finally oil palm plantations (11 species and 37 individuals). As expected, statistical differences were found among the studied habitats. Only 11% of species and 5% of the total captured birds were recorded in the African oil palm plantations. Our data show that oil palm cultivation represents a serious threat to biological diversity, making it a priority to generate guidelines based on scientific and conservation criteria

    Complex regional pain syndrome (CRPS), a review

    Get PDF
    Complex regional pain syndrome is a chronic and painful condition that affects the quality of life of patients. It is usually triggered by a traumatic event of the soft tissues involving the nervous tissue. Although the factors that cause the syndrome are varied and not well known, different etiopathologic concepts have been proposed to explain the presence of this syndrome, such as autonomic dysfunction and changes in CNS plasticity, among others. The patient characteristically presents pain, sensory abnormalities, vasomotor disturbances in the skin, edema, changes in sweating, and motor alterations. The pain is associated with changes in the autonomic nervous system and has a distal predominance. Since there is no definitive diagnostic test, diagnosis is mainly based on a complete medical history and physical examination. Treatment is multidisciplinary and based on pain relief. Although in most cases evolution is favorable, rapid diagnosis and treatment are recommended to avoid dystrophic stage as much as possibl

    Predicting potential distribution and identifying priority areas for conservation of the Yellow-tailed Woolly Monkey (Lagothrix flavicauda) in Peru

    Get PDF
    Species distribution models (SDMs) provide conservationist with spatial distributions estimations of priority species. Lagothrix flavicauda (Humboldt, 1812), commonly known as the Yellow-tailed Woolly Monkey, is one of the largest primates in the New World. This species is endemic to the montane forests of northern Peru, in the departments of Amazonas, San Martín, Huánuco, Junín, La Libertad, and Loreto at elevation from1,000 to 2,800 m. It is classified as “Critically Endangered” (CR) by the International Union for Conservation of Nature (IUCN) as well as by Peruvian legislation. Furthermore, it is listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Research on precise estimates of its potential distribution are scare. Therefore, in this study we modeled the potential distribution area of this species in Peru, the model was generated using the MaxEnt algorithm, along with 80 georeferenced occurrence records and 28 environmental variables. The total distribution (high, moderate, and low) for L. flavicauda is 29,383.3 km2, having 3,480.7 km2 as high potential distribution. In effect, 22.64 % (6,648.49 km2) of the total distribution area of L. flavicauda is found within Natural Protected Areas (NPAs), with the following categories representing the largest areas of distribution: Protected Forests (1,620.41 km2), Regional Conservation Areas (1,976.79 km2), and Private Conservation Areas (1,166.55 km2). After comparing the predicted distribution with the current NPAs system, we identified new priority areas for the conservation of the species. We, therefore, believe that this study will contribute significantly to the conservation of L. flavicauda in Peru

    Concentraciones de inmunoglobulina G sérica en alpacas neonatas muertas por enterotoxemia

    Get PDF
    The objective of the present study was to determine the levels of serum immunoglobulin G (IgG) in neonatal alpacas (5-23 days of age) killed by enterotoxemia and in animals of similar ages, but clinically healthy. In a first phase, a standard curve of physiological degradation of serum IgG was established from blood sera of six apparently healthy neonates from day 2 to 21 days of age (n=9). In a second phase, serum IgG concentrations were determined in 17 dead neonatal alpacas with lesions compatible with enterotoxemia and in 26 animals of similar ages, apparently healthy. The concentrations of IgG, determined by the Radial Immunodiffusion test, showed that all the animals at 48 hours of birth had adequate concentrations of IgG, while only three of the animals killed by enterotoxemia had IgG levels below the obtained standard curve, although only one of them with levels below 900 mg/dl at 14 days, which could be considered as a partial passive transfer failure. The serum IgG concentrations of the 26 clinically normal animals (2893 mg/dl) and those obtained from animals killed by enterotoxemia (2361 mg/dl) were statistically similar. The risk analysis using the Odds Ratio test (OR: 5.35, CI = 0.50-57.22) indicated that there is no association between adequate levels of IgG and mortality from enterotoxemia in neonatal alpacas.El presente estudio tuvo como objetivo determinar los niveles de Inmunoglobulina G (IgG) sérica en alpacas neonatas (5-23 días de edad) muertas por enterotoxemia y en animales de edades similares, pero clínicamente sanos. En una primera fase se estableció una curva estándar de degradación fisiológica de la IgG sérica a partir de sueros sanguíneos de seis neonatos aparentemente sanos a partir del día 2 y hasta los 21 días de edad (n=9). En una segunda fase se determinaron las concentraciones de IgG sérica en 17 alpacas neonatas muertas con lesiones compatibles con enterotoxemia y en 26 animales, de edades similares, aparentemente sanos. Las concentraciones de IgG, determinadas por la prueba de Inmunodifusión Radial, evidenciaron que todas las crías a las 48 horas del nacimiento presentaron concentraciones adecuadas de IgG, mientras que solo tres de los animales muertos por enterotoxemia tenían niveles de IgG por debajo de la curva estándar de degradación, aunque solo una de ellas con niveles inferiores a 900 mg/dl a los 14 días, lo que podría ser considerado como falla parcial de transferencia pasiva. Las concentraciones de IgG sérica de los 26 animales clínicamente normales (2893 mg/dl) y aquellas obtenidas de animales muertos por enterotoxemia (2361 mg/dl) fueron estadísticamente similares. El análisis de riesgo mediante la prueba de Odds Ratio (OR: 5.35; IC= 0.50-57.22) indicó que no existe asociación entre niveles adecuados de IgG y la mortalidad por enterotoxemia en alpacas neonatas

    Flavonoids as a Natural Treatment Against Entamoeba histolytica

    Get PDF
    Over the past 20 years, gastrointestinal infections in developing countries have been a serious health problem and are the second leading cause of morbidity among all age groups. Among pathogenic protozoans that cause diarrheal disease, the parasite Entamoeba histolytica produces amebic colitis as well as the most frequent extra-intestinal lesion, an amebic liver abscess (ALA). Usually, intestinal amebiasis and ALA are treated with synthetic chemical compounds (iodoquinol, paromomycin, diloxanide furoate, and nitroimidazoles). Metronidazole is the most common treatment for amebiasis. Although the efficacy of nitroimidazoles in killing amebas is known, the potential resistance of E. histolytica to this treatment is a concern. In addition, controversial studies have reported that metronidazole could induce mutagenic effects and cerebral toxicity. Therefore, natural and safe alternative drugs against this parasite are needed. Flavonoids are natural polyphenolic compounds. Flavonoids depend on malonyl-CoA and phenylalanine to be synthesized. Several flavonoids have anti-oxidant and anti-microbial properties. Since the 1990s, several works have focused on the identification and purification of different flavonoids with amebicidal effects, such as, -(-)epicatechin, kaempferol, and quercetin. In this review, we investigated the effects of flavonoids that have potential amebicidal activity and that can be used as complementary and/or specific therapeutic strategies against E. histolytica trophozoites. Interestingly, it was found that these natural compounds can induce morphological changes in the amebas, such as chromatin condensation and cytoskeletal protein re-organization, as well as the upregulation and downregulation of fructose-1,6-bisphosphate aldolase, glyceraldehyde-phosphate dehydrogenase, and pyruvate:ferredoxin oxidoreductase (enzymes of the glycolytic pathway). Although the specific molecular targets, bioavailability, route of administration, and doses of some of these natural compounds need to be determined, flavonoids represent a very promising and innocuous strategy that should be considered for use against E. histolytica in the era of microbial drug resistance

    VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

    Full text link
    VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaboro

    Vertical Boundary Mixing Events during Stratification Govern Heat and Nutrient Dynamics in a Windy Tropical Reservoir Lake with Important Water-Level Fluctuations: A Long-Term (2001–2021) Study

    Get PDF
    hysical processes play important roles in controlling eutrophication and oligotrophication. In stratified lakes, internal waves can cause vertical transport of heat and nutrients without breaking the stratification, through boundary mixing events. Such is the case in tropical Valle de Bravo (VB) reservoir lake, where strong diurnal winds drive internal waves, boundary mixing, and hypolimnetic warming during stratification periods. We monitored VB during 21 years (2001–2021) when important water-level fluctuations occurred, affecting mixing and nutrient flux. Stability also varied as a function of water level. Hypolimnetic warming (0.009–0.028 °C day−1) occurred in all the stratifications monitored. We analyzed temperature distributions and modeled the hypolimnion heat budget to assess vertical mixing between layers (0.639–3.515 × 10−6 m3 day−1), vertical diffusivity coefficient KZ (2.5 × 10−6–13.6 × 10−6 m2 s−1), and vertical nutrient transport to the epilimnion. Nutrient flux from the metalimnion to the epilimnion ranged 0.42–5.99 mg P m−2day−1 for soluble reactive phosphorus (SRP) and 5.8–101.7 mg N m−2day−1 for dissolved inorganic nitrogen (DIN). Vertical mixing and the associated nutrient fluxes increase evidently as the water level decreases 8 m below capacity, and they can increase up to fivefold if the water level drops over 12 m. The observed changes related to water level affect nutrient recycling, ecosystemic metabolic balance, and planktonic composition of VB.This research was funded by UNAM (PAPIIT-IN207702 and PAPIIT-IN111321) and by CONACYT-SEMARNAT (C01-1125) projects to M.M.-I.Peer reviewe
    corecore