46 research outputs found

    Modelling the potential impacts of climate change on the hydrology of the Aipe river basin in Huila, Colombia

    Full text link
    [EN] The dynamics of a global world, and humans performing as a new geological force, require that an effort is undertaken to make robust decisions in order to devise strategies for the management and adaptation to climate change. This study aims to investigate the potential impact of climate change on the hydrology of the Aipe river basin in Huila, Colombia. The abcd Thomas model (four parameters) was calibrated and validated for the stream flows of the Aipe catchment (1992Âż2012). The sensitivity and identifiability of the parameters were evaluated using the Monte Carlo Analysis Toolbox (MCAT). The results show the ability of the model to simulate the monthly stream flow (NashÂżSutcliffe efficiency coefficient of 0,89). The most influential parameters are: a (water storage in the soil) and c (contribution to the aquifer). From the simulated scenarios, the baseline (1992Âż2012) was estimated to be an average flow of 15,44 m3sÂż1; the trend extrapolation scenario estimated a rate 13,79 m3sÂż1 (Âż10,64%); while for the multi-model assembly scenario it was 9,34 m3sÂż1 (Âż39,47%) and for the A2 scenario it was 5,74 m3sÂż1 (Âż62,60%). Lastly, we propose a set of strategies for adaptation to climate change that are committed to the integral management of water resources.[ES] La dinĂĄmica de un mundo global y el hombre como nueva fuerza geolĂłgica plantean la necesidad de tomar decisiones robustas, diseñar estrategias de manejo y de adaptarse al cambio climĂĄtico. Este estudio investiga la respuesta hidrolĂłgica de la cuenca hidrogrĂĄfica del rĂ­o Aipe (688.9 km2 ), en Huila, Colombia, en acorde con los escenarios de cambio climĂĄtico desde 2011 a 2040. El modelo hidrolĂłgico abcd de Thomas (4 parĂĄmetros) fue calibrado y validado comparando el caudal simulado y lo observado en el punto de cierre de la cuenca (en la estaciĂłn Puente Carretera), usando series histĂłricas mensuales (1992Âż2012). Realizamos la evaluaciĂłn de la sensibilidad e identificabilidad de los parĂĄmetros con la herramienta `Monte Carlo Analysis ToolboxÂż (MCAT). Los resultados muestran que el modelo es capaz de representar adecuadamente los caudales mensuales observados en el punto de desagĂŒe de la cuenca, al encontrarse un Ă­ndice de eficiencia de NashÂżSutcliffe (NSE) de 0,89. Los parĂĄmetros mĂĄs influyentes son a (almacenamiento del agua en el suelo) y c (aporte al acuĂ­fero). Con respecto a la simulaciĂłn de los escenarios, la lĂ­nea base (1992Âż2012) estimĂł un caudal medio de 15,44 m3 s Âż1 ; el escenario de extrapolaciĂłn de tendencias estimĂł un caudal de 13,79 m3 s Âż1 (Âż10,64%); el escenario de ensamble multi-modelo de 9,34 m3 s Âż1 (Âż39,47%) y el escenario A2 de 5,74 m3 s Âż1 (Âż62,60%). Proponemos una baterĂ­a de medidas de adaptaciĂłn al cambio climĂĄtico que buscan la gestiĂłn integral del recurso hĂ­drico.Romero-Cuellar, J.; Buitrago-Vargas, A.; Quintero-Ruiz, T.; FrancĂ©s, F. (2018). SimulaciĂłn hidrolĂłgica de los impactos potenciales del cambio climĂĄtico en la cuenca hidrogrĂĄfica del rĂ­o Aipe, en Huila, Colombia. RIBAGUA - Revista Iberoamericana del Agua. 5(1):63-78. https://doi.org/10.1080/23863781.2018.1454574S63785

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

    Get PDF
    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Risky Business: Focus-Group Analysis of Sexual Behaviors, Drug use and Victimization among Incarcerated Women in St. Louis

    No full text
    Incarcerated women report multiple vulnerabilities and, yet, are under-represented in research. This study used focus-group methodology to explore high-risk sexual behaviors, drug use, and victimization among female offenders in St. Louis. Inmates of the St. Louis Medium Security Institution (MSI) were invited to participate in one of five focus groups between May and September 2005 in preparation for an NIH/NINR HIV-prevention intervention study among female offenders in Drug Court. The focus group sample of 30 women was 70% African-American, with a mean age of 36 years. Results indicated that oral sex was the most common sex trade activity. Consistent with the literature, condom usage was described as irregular. In terms of drug use, participants reported that crack was most commonly used, with binges often lasting for several days. Regarding victimization, women frequently reported sexual abuse in childhood, and some described abusive relationships as adults. Participants also reported being beaten and raped by customers, which led to their concealing knives in purses and razors under the tongue. Consequently, perpetrated violence, including murder, was reported as protection against further violence. These findings confirm the vulnerability of this population of women who are at high risk for HIV. Effective HIV-prevention interventions are needed to assist these incarcerated women in making lifestyle changes during incarceration and sustaining them after release

    Transactional relationships and sex with a woman in prostitution: prevalence and patterns in a representative sample of South African men

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Sex motivated by economic exchange is a public health concern as a driver of the Sub-Saharan African HIV epidemic. We describe patterns of engagement in transactional sexual relationships and sex with women in prostitution of South African men, and suggest interpretations that advance our understanding of the phenomenon.</p> <p>Methods</p> <p>Cross-sectional study with a randomly-selected sample of 1645 sexually active men aged 18–49 years who completed interviews in a household study and were asked whether they had had sex with a woman in prostitution, or had had a relationship or sex they took to be motivated by the expectation of material gain (transactional sex).</p> <p>Results</p> <p>18% of men had ever had sex with a woman in prostitution, 66% at least one type of transactional sexual relationship, only 30% of men had done neither. Most men had had a transactional relationship/sex with a main partner (58% of all men), 42% with a concurrent partner (or <it>makhwapheni</it>) and 44% with a once off partner, and there was almost no difference in reports of what was provided to women of different partner types. The majority of men distinguished the two types of sexual relationships and even among men who had once-off transactional sex and gave cash (n = 314), few (34%) reported that they had had sex with a ‘prostitute’. Transactional sex was more common among men aged 25–34 years, less educated men and low income earners rather than those with none or higher income. Having had sex with a woman in prostitution varied little between social and demographic categories, but was less common among the unwaged or very low earners.</p> <p>Conclusions</p> <p>The notion of ‘transactional sex’ developed through research with women does not translate easily to men. Many perceive expectations that they fulfil a provider role, with quid pro quo entitlement to sex. Men distinguished these circumstances of sex from having sex with a woman in prostitution. Whilst there may be similarities, when viewed relationally, these are quite distinct practices. Conflating them is sociologically inappropriate. Efforts to work with men to reduce transactional sex should focus on addressing sexual entitlement and promoting gender inequity.</p
    corecore