120 research outputs found
Un poco de lo que se conoce - Cambio climático y ecosistemas marino-costeros
Una de mis tesistas me comentó, en días pasados, que un profesor que les dictaba un curso sobre los efectos del cambio climático en los ecosistemas, les había planteado que él no creía en el cambio climático. Me sorprendió que un profesor que está dando un curso como ese, no aceptara el cambio climático, pero comencé a divagar sobre el posible razonamiento del profesor. Concluí que el argumento del profesor se debía basar en que los cambios climáticos que estamos observando, de todas maneras iban a ocurrir en algún momento, porque estamos viviendo en una época interglaciar (entre glaciaciones, donde normalmente sucede un calentamiento global). Aunque es cierto que el cambio climático es un evento natural, no lo es la velocidad actual del cambio. El efecto de las actividades del hombre ha resultado en el aceleramiento de estos cambios (Hardoy y Pandiella, 2007). Se ha estimado que en un periodo interglaciar sin la actividad del hombre, la temperatura aumenta 1oC cada 500 años (Leggett, 1990), las predicciones más positivas estiman que la temperatura en la tierra puede aumentar entre 1.5 a 4.5oC para el 2030 (Schneider, 2002). Esto se apoya no sólo en modelos matemáticos, sino en el hecho de que la temperatura ha aumentado 0.6 + 0.2oC en los últimos 200 años (ipcc, 2007)
Review on hard coral recruitment (Cnidaria: Scleractinia) in Colombia
Recruitment, defined and measured as the incorporation of new individuals (i.e. coral juveniles) into a population, is a fundamental process for ecologists, evolutionists and conservationists due to its direct effect on population structure and function. Because most coral populations are self-feeding, a breakdown in recruitment would lead to local extinction. Recruitment indirectly affects both renewal and maintenance of existing and future coral communities, coral reef biodiversity (bottom-up effect) and therefore coral reef resilience. This process has been used as an indirect measure of individual reproductive success (fitness) and is the final stage of larval dispersal leading
to population connectivity. As a result, recruitment has been proposed as an indicator of coral-reef health in marine protected areas, as well as a central aspect of the decision-making process concerning management and conservation. The creation of management plans to promote impact mitigation,rehabilitation and conservation of the Colombian coral reefs is a necessity that requires firstly, a review and integration of existing literature on scleractinian coral recruitment in Colombia and secondly, larger scale field studies. This motivated us to summarize and analyze all existing information on coral recruitment to determine the state of knowledge, isolate patterns, identify gaps, and suggest future lines of research
Cambios que no hemos interiorizado: los arrecifes que aún desconocemos
Hace un par de años, el Instituto de Investigaciones Marinas y Costeras, invemar, inició una campaña llamada “Colombia 50% mar”, con el objetivo de que los colombianos interioricen y comprendan que el país es más grande de lo que se piensa, con un área marina casi tan grande como la terrestre. Esa extensión marina tiene una importancia que abarca muchos aspectos, por ejemplo, le otorga al país fronteras con países como Costa Rica, Nicaragua, Honduras y Jamaica
Animales que parecen piedras
Los corales duros o madreporarios suelen ser confundidos con piedras, sin embargo, estos organismos son animales de gran importancia debido a que son los principales formadores de uno de los ecosistemas más biodiversos del planeta: los arrecifes coralinos. Los corales son animales sencillos morfológicamente, pero complejos ecológicamente. Esta complejidad está asociada a que generalmente viven en colonias clonales que poseen exoesqueletos de carbonato de calcio. Cuando los corales se reproducen y se fecunda un huevo se desarrolla una larva que tiene la capacidad de buscar un sitio en el fondo marino para asentarse y comenzar a crecer. Este comenzar a crecer significa que la larva se transforma en un pólipo y comienza a formar un exoesqueleto de carbonato de calcio el cual le da protección y forma. Una vez el pólipo está totalmente desarrollado puede dividirse en dos y estos dos se dividirán a su vez, por lo que unos años después se tendrá una colonia. Las colonias van creciendo mediante la producción de nuevos pólipos, todos genéticamente idénticos (o clonales), y en este proceso se va acumulando carbonato de calcio, el cual es el material que compone los arrecifes coralinos. En este artículo se resumen los aspectos biológicos y ecológicos más importantes de los corales que forman los arrecifes coralinos
Bleaching susceptibility and recovery of Colombian Caribbean corals in response to water current exposure and seasonal upwelling
Coral bleaching events are globally occurring more frequently and with higher intensity, mainly caused by increases in seawater temperature. In Tayrona National Natural Park (TNNP) in the Colombian Caribbean, local coral communities are subjected to seasonal wind-triggered upwelling events coinciding with stronger water currents depending on location. This natural phenomenon offers the unique opportunity to study potential water current-induced mitigation mechanisms of coral bleaching in an upwelling influenced region. Therefore, coral bleaching susceptibility and recovery patterns were compared during a moderate and a mild bleaching event in December 2010 and 2011, and at the end of the subsequent upwelling periods at a water current-exposed and -sheltered site of an exemplary bay using permanent transect and labeling tools. This was accompanied by parallel monitoring of key environmental variables. Findings revealed that in 2010 overall coral bleaching before upwelling was significantly higher at the sheltered (34%) compared to the exposed site (8%). Whereas 97% of all previously bleached corals at the water current-exposed site had recovered from bleaching by April 2011, only 77% recovered at the sheltered site, but 12% had died there. In December 2011, only mild bleaching
A proposal for a structural equations model to explain academic performance in e-learning
Purpose: In this work we present the advances of a research project whose main goal is the construction and empirical validation of a structural equation modeling to explain the students’ academic performance in Administration distance degree careers of the Universidad de la Defensa Nacional (Argentina).
Methodology/Approach: A structural model with six latent variables, five endogenous and one exogenous, was formulated as a result of bibliographic background integration.
Findings: a measurement model formulation was obtained which, integrated to the causal model proposed in the previous stage, allowed us to reach a complete structural equation model specification.
Research Limitation/implication: consider that the observed variables selected are the ones that best combine to identify the hypothesized constructs.
Originality/Value of paper: Learning in virtual environments is the main endogenous latent variable of the model, explained by previous knowledge, motivation, digital skills, self-regulation and interaction processes.https://revistas.cefet-rj.br/index.php/producaoedesenvolvimento/article/view/422publishedVersionFil: Moneta Pizarro, Adrián. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: González, Mariana. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Tofful, Carina Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Arrieta, Mercedes. Universidad de la Defensa Nacional; Argentina.Fil: Britos, Valeria. Universidad Nacional de Córdoba. Facultad de Ciencias Sociales. Área de Tecnología Educativa y Acceso Abierto; Argentina.Otras Ciencias de la Educació
Cambios que no hemos interiorizado: los arrecifes que aún desconocemos
Hace un par de años, el Instituto de Investigaciones Marinas y Costeras, INVEMAR, inició una campaña llamada “Colombia 50% mar”, con el objetivo de que los colombianos interioricen y comprendan que el país es más grande de lo que se piensa, con un área marina casi tan grande como la terrestre. Esa extensión marina tiene una importancia que abarca muchos aspectos, por ejemplo, le otorga al país fronteras con países como Costa Rica, Nicaragua, Honduras y Jamaica
Revisión y estado del arte de la restauración ecológica de arrecifes coralinos
Coral reefs are important coastal ecosystems for both humans and marine species due to the diversity of ecosystem services they provide. Unfortunately, and as a consequence of anthropogenic and natural factors these ecosystems are disappearing. To mitigate coral reef degradation and potential loss, several active and passive conservation strategies have been implemented. Active strategies imply the direct intervention of humans in the ecosystem. Ecological restoration (ER) is an active strategy recently used in marine ecosystems. However, since the 1980s, different methodologies have been designed and implemented to mitigate threats and recover degraded coral reefs. Currently, although still under development, the most used ER methodologies on coral reefs are coral rearing through asexual and sexual propagation, and double restoration. This paper presents a general description of coral reef ER. It begins with characteristics of reef building corals ER methods and experiences, and ends with recommendations for those who want to develop and implement ER processes on coral reefs.Los arrecifes coralinos son ecosistemas costeros de gran importancia para el hombre y especies marinas por la diversidad de servicios ecosistémicos que ofrecen. Desafortunadamente y a consecuencia de factores antropogénicos y naturales están perdiéndose rápidamente. Para frenar su degradación y potencial pérdida, se han diseñado e implementado estrategias de conservación pasivas y activas. En estas últimas, que implican la intervención directa del hombre sobre el ecosistema, se ubica la restauración ecológica (RE), la cual lleva pocos años implementándose en ecosistemas marinos. Sin embargo, desde comienzo de la década de 1980 se vienen implementando diferentes métodos con el fin de mitigar amenazas y recuperar los arrecifes degradados. En la actualidad, aunque aún están en etapas experimentales, los métodos de RE en arrecifes coralinos más utilizados son la cría de corales mediante propagación asexual y sexual, y la restauración doble. En este artículo se presenta una descripción general sobre la RE en arrecifes coralinos, comenzando con características de los corales constructores de arrecifes, pasando por los métodos que más se están aplicando y haciendo un recorrido por las experiencias que se han y están desarrollando en todo el mundo. Se finaliza con unas recomendaciones para los interesados implementar procesos de RE en arrecifes coralinos
Auditory processing assessment in children with obstructive sleep apnea syndrome
INTRODUCTION: The obstructive sleep apnea syndrome (OSAS) is a respiratory disorder that occurs during sleep and it is relatively common in children. AIM: The goal of this paper is to verify if there is a relationship between the obstructive sleep apnea syndrome (OSAS) and auditory processing. METHOD: In order to do that, three groups of children ranging in age from 5 to 11 were studied, including a normal group. Twenty subjects who made up the study group were submitted to ear, nose and throat (ENT) exams and to polysomnography (PSG), and were divided in two groups: GROUP I (RO) comprised of 10 children who presented oral breathing and displayed normal PSG, and GROUP II (SAS) comprised of 10 children who presented oral breathing and displayed abnormal PSG. Their performance was compared to the performance of the third group - GROUP III (REN) comprised of 10 children who did not refer ENT difficulties. All the subjects completed a basic audiometric assessment as well as an auditory processing diagnosis. RESULTS: The analyses of the results revealed a statistically significant difference in ENT exams related to the turbinate and the palatine tonsils. Group II presented a higher incidence of turbinate hypertrophy levels II and III (p < 0.001) and palatine tonsils hypertrophy grades III and IV (p 0.007). Regarding the auditory processing assessment, a statistically significant difference (p < 0.001) was obtained in the dichotic digits test. Group II performed worse than group III. Also, for the non-verbal sequence memory test, Group II obtained a worse result (p < 0.022) than Group I. CONCLUSIONS: Subjects with OSAS obtained worse results in auditory processing tests.INTRODUÇÃO: síndrome da apnéia/hipopnéia obstrutiva do sono (SAHOS) é uma desordem de respiração durante o sono e tem sido descrita como uma condição relativamente comum em crianças. OBJETIVO: Verificar se existe relação entre a presença da Síndrome da Apnéia/Hipopnéia Obstrutiva do Sono e alteração de processamento auditivo. MÉTODOS: Foram avaliados 3 grupos de crianças na faixa etária de 5 a 11 anos, incluindo um grupo controle. Vinte indivíduos que constituíram o grupo de estudo foram submetidos à avaliação otorrinolaringológica e ao exame de polissonografia (PSG) e foram divididos em dois grupos: Grupo I (RO) constituído por 10 indivíduos respiradores orais e PSG normal e Grupo II (SAS) constituído por 10 indivíduos respiradores orais e PSG alterado. O desempenho destes indivíduos foi comparado a um terceiro grupo - Grupo III (REN) composto de 10 crianças sem queixas otorrinolaringológicas. Todos os sujeitos foram submetidos à avaliação audiológica básica e à avaliação do PA. RESULTADOS: Quanto à avaliação otorrinolaringológica, houve diferença estatisticamente significante no que se refere à avaliação dos cornetos nasais e das tonsilas palatinas. No grupo II, verificou-se maior número de indivíduos com hipertrofia de cornetos nasais grau II e III (p < 0,001) e com hipertrofia de tonsila palatina grau III e IV (p 0,007). Em relação à avaliação de PA, os resultados mostraram que houve diferença estatisticamente significante (p < 0,001) no teste dicótico de dígitos, tendo o grupo II apresentado pior desempenho do que o grupo III e, no resultado do teste de memória para sons não-verbais em seqüência (p < 0,022), tendo o grupo II apresentado pior desempenho do que o grupo I. CONCLUSÃO: A presença da SAHOS relacionou-se positivamente com a alteração de processamento auditivo.UNIFESP/ EPMUNICAMP FCMUNIFESP / EPM Departamento de PsicobiologiaUNIFESP / EPM Departamento de FonoaudiologiaUniversidade Federal de São Paulo (UNIFESP) - UNIFESPUNIFESPUNIFESP/ EPMUNIFESP, / EPM Depto. de PsicobiologiaUNIFESP, / EPM Depto. de FonoaudiologiaUNIFESP, - UNIFESPSciEL
Psychological Impact of COVID-19 Lockdown on Well-being: Comparisons between People with Obesity, with Diabetes and without Diseases
Introduction: Obesity and type 2 diabetes mellitus are two chronic diseases most associated with hospitalizationsand deaths from COVID-19.Background: This study compared psychological impact of COVID-19 lockdown in people with obesity, people with type 2 diabetes (T2D) and people without diseases, and determined the factors associated with well-being.Materials and methods: An online survey on negative affect, attitudes, social support and sharing, coping,well-being, and eating behavior was conducted in 157 people with obesity, 92 with type 2 diabetes and 288without diseases.Results: People with obesity were the most worried of getting infected (70%) or dying (64%) and had the highest levels of emotional eating. People with T2D showed better coping strategies and higher well-being. Negative affect, worries about COVID-19 consequences and uncontrolled eating had negative impact, but social support, social sharing, and coping contributed positively (p < 0.001) to well-being. A 48.7% of people with obesity experienced more difficulties to adhere to treatment compared to only 11.1% of people with T2D.Conclusions: People with obesity had less well-being and more COVID-19 worries and emotional eating than people with T2D and without diseases. Well-being depends on negative affect, worries and eating behavior. Future research about the impact in long-term on weight and health status in patients with chronic diseases is needed
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