201 research outputs found
Bursts of ciguatera and endo-upwelling process on coral reef
Il est proposé une relation de cause à affet entre les flambées de ciguatera consécutives à une agression subie par une zone récifale et les sorties d'eaux interstitielles par endo upwelling riches en nutriments. Ceux-ci n'étant plus utilisés par un écosystème algo corallien stressé ou éliminé, le sont par des planctontes épibenthiques comme #Gambierdiscus toxicus$ dont la population augmente brutalement. (Résumé d'auteur
Le blanchiment corallien : cause de prolifération latente de Gambierdiscus toxicus = Coral bleaching as a cause of potential proliferation of Gambierdiscus toxicus
Critical Issues in the Development of Health Information Systems in Supporting Environmental Health: A Case Study of Ciguatera
Emerging environmental pressures resulting from climate change and globalization challenge the capacity of health information systems (HIS) in the Pacific to inform future policy and public health interventions. Ciguatera, a globally common marine food-borne illness, is used here to illustrate specific HIS challenges in the Pacific and how these might be overcome proactively to meet the changing surveillance needs resulting from environmental change.We review and highlight inefficiencies in the reactive nature of existing HIS in the Pacific to collect, collate, and communicate ciguatera fish poisoning data currently used to inform public health intervention. Further, we review the capacity of existing HIS to respond to new data needs associated with shifts in ciguatera disease burden likely to result from coral reef habitat disruption.Improved knowledge on the ecological drivers of ciguatera prevalence at local and regional levels is needed, combined with enhanced surveillance techniques and data management systems, to capture environmental drivers as well as health outcomes data.The capacity of public HIS to detect and prevent future outbreaks is largely dependent on the future development of governance strategies that promote proactive surveillance and health action. Accordingly, we present an innovative framework from which to stimulate scientific debate on how this might be achieved by using existing larger scale data sets and multidisciplinary collaborations
Caracterização de módulos fotovoltáicos orgânicos (P3HT:PCBM) com radiação solar
Los principales parámetros que influyen en la eficiencia de módulo solar orgánico de capa activa P3HT:PCBM, se analizan en este trabajo en condiciones reales de la radiación solar. Los experimentos se llevaron a cabo en la Universidad Federal de Pernambuco en Recife, Pernambuco, Brasil. Por medio del análisis de los resultados se puede observar el comportamiento de los parámetros eléctricos de un módulo orgánico en función de la irradiación y, por tanto, entender cómo funcionaría un sistema que utiliza la electricidad generada a partir de paneles orgánicos.The main parameters that influence the efficiency of organic solar module active layer P3HT:PCBM, are analyzed in this work in real conditions of solar radiation. The experiments were conducted at the Federal University of Pernambuco in Recife, Pernambuco, Brazil. Through analysis of the results, it is possible to observe the behavior of the electrical parameters of an organic module depending on the irradiance and thus, better understand how it would work in a system using electricity generated from organic panels.Tema 4: Energía solar, conversión fotovoltaica.Facultad de Arquitectura y Urbanism
Caracterização de módulos fotovoltáicos orgânicos (P3HT:PCBM) com radiação solar
Los principales parámetros que influyen en la eficiencia de módulo solar orgánico de capa activa P3HT:PCBM, se analizan en este trabajo en condiciones reales de la radiación solar. Los experimentos se llevaron a cabo en la Universidad Federal de Pernambuco en Recife, Pernambuco, Brasil. Por medio del análisis de los resultados se puede observar el comportamiento de los parámetros eléctricos de un módulo orgánico en función de la irradiación y, por tanto, entender cómo funcionaría un sistema que utiliza la electricidad generada a partir de paneles orgánicos.The main parameters that influence the efficiency of organic solar module active layer P3HT:PCBM, are analyzed in this work in real conditions of solar radiation. The experiments were conducted at the Federal University of Pernambuco in Recife, Pernambuco, Brazil. Through analysis of the results, it is possible to observe the behavior of the electrical parameters of an organic module depending on the irradiance and thus, better understand how it would work in a system using electricity generated from organic panels.Tema 4: Energía solar, conversión fotovoltaica.Facultad de Arquitectura y Urbanism
Caracterização de módulos fotovoltáicos orgânicos (P3HT:PCBM) com radiação solar
Los principales parámetros que influyen en la eficiencia de módulo solar orgánico de capa activa P3HT:PCBM, se analizan en este trabajo en condiciones reales de la radiación solar. Los experimentos se llevaron a cabo en la Universidad Federal de Pernambuco en Recife, Pernambuco, Brasil. Por medio del análisis de los resultados se puede observar el comportamiento de los parámetros eléctricos de un módulo orgánico en función de la irradiación y, por tanto, entender cómo funcionaría un sistema que utiliza la electricidad generada a partir de paneles orgánicos.The main parameters that influence the efficiency of organic solar module active layer P3HT:PCBM, are analyzed in this work in real conditions of solar radiation. The experiments were conducted at the Federal University of Pernambuco in Recife, Pernambuco, Brazil. Through analysis of the results, it is possible to observe the behavior of the electrical parameters of an organic module depending on the irradiance and thus, better understand how it would work in a system using electricity generated from organic panels.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES
Tuna labels matter in Europe: Mislabelling rates in different tuna products
Tuna fisheries and processing represent economic activities of paramount importance around the world. Most of these products are traded for human consumption and in general are highly demanded commodities. However, not all tuna products achieve the same market price, some consumers are willing to pay a huge amount of money for certain species (i.e. Japanese market for Bluefin tuna) while other species are rather affordable (i.e. Skipjack tuna), therefore mislabelling has been observed frequently. We collected and analysed 545 tuna samples in six European countries, including fresh, frozen and canned products, and we have investigated whether or not these products were correctly labelled under European and national legislations. We found an overall mislabelling rate of 6.79%; in particular, 6.70% of the fresh and frozen tuna products and 7.84% of canned tuna were mislabelled, and only in the case of fresh and frozen tuna samples significant differences among countries were found. Mislabelling rates for Atlantic Bluefin tuna labelled products were very high, ranging from 50 up to 100%. In general, mislabelling was higher when specific names were included in the labels. The “tuna” umbrella term is a very popular one with consumers, but also one that remains vulnerable to ambiguity, hampering efforts towards market transparency and with potential negative consequences to the adequate management of tuna species stocks
Utilization of a deoxynucleoside diphosphate substrate by HIV reverse transcriptase
Background: Deoxynucleoside triphosphates (dNTPs) are the normal substrates for DNA sysnthesis is catalyzed by polymerases such as HIV-1 reverse transcriptase (RT). However, substantial amounts of deoxynucleoside diphosphates (dNDPs) are also present in the cell. Use of dNDPs in HIV-1 DNA sysnthesis could have significant implications for the efficacy of nucleoside RT inhibitors such as AZT which are first line therapeutics fro treatment of HIV infection. Our earlier work on HIV-1 reverse transcriptase (RT) suggested that the interaction between the γ phosphate of the incoming dNTP and RT residue K65 in the active site is not essential for dNTP insertion, implying that this polymerase may be able to insert dNPs in addition to dNTPs. Methodology/Principal Findings: We examined the ability of recombinant wild type (wt) and mutant RTs with substitutions at residue K65 to utilize a dNDP substrate in primer extension reactions. We found that wild type HIV-1 RT indeed catalyzes incorporation of dNDP substrates whereas RT with mutations of residue K645 were unable to catalyze this reaction. Wild type HIV-1 RT also catalyzed the reverse reaction, inorganic phosphate-dependent phosphorolysis. Nucleotide-mediated phosphorolytic removal of chain-terminating 3′-terminal nucleoside inhibitors such as AZT forms the basis of HIV-1 resistance to such drugs, and this removal is enhanced by thymidine analog mutations (TAMs). We found that both wt and TAM-containing RTs were able to catalyze Pi-mediated phosphorolysis of 3′-terminal AZT at physiological levels of Pi with an efficacy similar to that for ATP-dependent AZT-excision. Conclusion: We have identified two new catalytic function of HIV-1 RT, the use of dNDPs as substrates for DNA synthesis, and the use of Pi as substrate for phosphorolytic removal of primer 3′-terminal nucleotides. The ability to insert dNDPs has been documented for only one other DNA polymerase The RB69 DNA polymerase and the reverse reaction employing inorganic phosphate has not been documented for any DNA polymerase. Importantly, our results show that Pi-mediated phosphorolysis can contribute to AZT resistance and indicates that factors that influence HIV resistance to AZT are more complex than previously appreciated. © 2008 Garforth et al
Outdoor performance of organic photovoltaics at two different locations: a comparison of degradation and the effect of condensation
Tests on organic photovoltaics (OPV) mini modules, fabricated through a R2R process, in air and without hazardous solvents have been conducted in order to compare their outdoor performance, in Belo Horizonte, Brazil, and Bangor, North Wales, and assess the impact of the latitude and climate of the installation on the power generation and modules' lifetime. The test showed different profiles of degradation for each region and formulation, with a surprisingly faster degradation in Bangor. One of the possible sources of the increased degradation is the greater levels of condensation observed in Bangor. To verify the impact of condensation on the module stability, indoor tests have been conducted to relate the dew point depression to module degradation times. The results show that condensation is a significant stress factor in OPV and should be considered more prominently in reliability studies
Aquatic food security:insights into challenges and solutions from an analysis of interactions between fisheries, aquaculture, food safety, human health, fish and human welfare, economy and environment
Fisheries and aquaculture production, imports, exports and equitability of distribution determine the supply of aquatic food to people. Aquatic food security is achieved when a food supply is sufficient, safe, sustainable, shockproof and sound: sufficient, to meet needs and preferences of people; safe, to provide nutritional benefit while posing minimal health risks; sustainable, to provide food now and for future generations; shock-proof, to provide resilience to shocks in production systems and supply chains; and sound, to meet legal and ethical standards for welfare of animals, people and environment. Here, we present an integrated assessment of these elements of the aquatic food system in the United Kingdom, a system linked to dynamic global networks of producers, processors and markets. Our assessment addresses sufficiency of supply from aquaculture, fisheries and trade; safety of supply given biological, chemical and radiation hazards; social, economic and environmental sustainability of production systems and supply chains; system resilience to social, economic and environmental shocks; welfare of fish, people and environment; and the authenticity of food. Conventionally, these aspects of the food system are not assessed collectively, so information supporting our assessment is widely dispersed. Our assessment reveals trade-offs and challenges in the food system that are easily overlooked in sectoral analyses of fisheries, aquaculture, health, medicine, human and fish welfare, safety and environment. We highlight potential benefits of an integrated, systematic and ongoing process to assess security of the aquatic food system and to predict impacts of social, economic and environmental change on food supply and demand
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