Guidelines Used (guideline + used)

Distribution by Scientific Domains

Selected Abstracts

Quantification of Extinction Risk: IUCN's System for Classifying Threatened Species

definición de prioridades de conservación; especies amenazadas; Lista Roja UICN; riesgo de extinción Abstract:,The International Union for Conservation of Nature (IUCN) Red List of Threatened Species was increasingly used during the 1980s to assess the conservation status of species for policy and planning purposes. This use stimulated the development of a new set of quantitative criteria for listing species in the categories of threat: critically endangered, endangered, and vulnerable. These criteria, which were intended to be applicable to all species except microorganisms, were part of a broader system for classifying threatened species and were fully implemented by IUCN in 2000. The system and the criteria have been widely used by conservation practitioners and scientists and now underpin one indicator being used to assess the Convention on Biological Diversity 2010 biodiversity target. We describe the process and the technical background to the IUCN Red List system. The criteria refer to fundamental biological processes underlying population decline and extinction. But given major differences between species, the threatening processes affecting them, and the paucity of knowledge relating to most species, the IUCN system had to be both broad and flexible to be applicable to the majority of described species. The system was designed to measure the symptoms of extinction risk, and uses 5 independent criteria relating to aspects of population loss and decline of range size. A species is assigned to a threat category if it meets the quantitative threshold for at least one criterion. The criteria and the accompanying rules and guidelines used by IUCN are intended to increase the consistency, transparency, and validity of its categorization system, but it necessitates some compromises that affect the applicability of the system and the species lists that result. In particular, choices were made over the assessment of uncertainty, poorly known species, depleted species, population decline, restricted ranges, and rarity; all of these affect the way red lists should be viewed and used. Processes related to priority setting and the development of national red lists need to take account of some assumptions in the formulation of the criteria. Resumen:,La Lista Roja de Especies Amenazadas de la UICN (Unión Internacional para la Conservación de la Naturaleza) fue muy utilizada durante la década de l980 para evaluar el estatus de conservación de especies para fines políticos y de planificación. Este uso estimuló el desarrollo de un conjunto nuevo de criterios cuantitativos para enlistar especies en las categorías de amenaza: en peligro crítico, en peligro y vulnerable. Estos criterios, que se pretendía fueran aplicables a todas las especies excepto microorganismos, eran parte de un sistema general para clasificar especies amenazadas y fueron implementadas completamente por la UICN en 2000. El sistema y los criterios han sido ampliamente utilizados por practicantes y científicos de la conservación y actualmente apuntalan un indicador utilizado para evaluar el objetivo al 2010 de la Convención de Diversidad Biológica. Describimos el proceso y el respaldo técnico del sistema de la Lista Roja de la IUCN. Los criterios se refieren a los procesos biológicos fundamentales que subyacen en la declinación y extinción de una población. Pero, debido a diferencias mayores entre especies, los procesos de amenaza que los afectan y la escasez de conocimiento sobre la mayoría de las especies, el sistema de la UICN tenía que ser amplio y flexible para ser aplicable a la mayoría de las especies descritas. El sistema fue diseñado para medir los síntomas del riesgo de extinción, y utiliza cinco criterios independientes que relacionan aspectos de la pérdida poblacional y la declinación del rango de distribución. Una especie es asignada a una categoría de amenaza si cumple el umbral cuantitativo por lo menos para un criterio. Los criterios, las reglas acompañantes y las directrices utilizadas por la UICN tienen la intención de incrementar la consistencia, transparencia y validez de su sistema de clasificación, pero requiere algunos compromisos que afectan la aplicabilidad del sistema y las listas de especies que resultan. En particular, se hicieron selecciones por encima de la evaluación de incertidumbre, especies poco conocidas, especies disminuidas, declinación poblacional, rangos restringidos y rareza; todas estas afectan la forma en que las listas rojas deberían ser vistas y usadas. Los procesos relacionados con la definición de prioridades y el desarrollo de las listas rojas nacionales necesitan considerar algunos de los supuestos en la formulación de los criterios. [source]

Contaminated suspended sediments toxic to an Antarctic filter feeder: Aqueous- and particulate-phase effects

Nicole A. Hill
Abstract Disturbances such as dredging, storms, and bioturbation result in the resuspension of sediments. This may affect sessile organisms that live on hard substrates directly above the sediment. Localized sediment contamination exists around many Antarctic research stations, often resulting in elevated contamination loads in marine sediments. To our knowledge, the potential impact of resuspended contaminated sediments on sessile fauna has not been considered, so in the present study, we assessed the sensitivity of Antarctic spirorbid polychaetes to aqueous metals and to metal-contaminated sediments that had been experimentally resuspended. Worms were first exposed to aqueous metals, both singly and in combination, over 10 d. Spirorbid mortality was tolerant to copper (median lethal concentration [LC50], 570 ,g/L), zinc (LC50, >4,910 ,g/L), and lead (LC50, >2,905 ,g/L); however, spirorbid behavior responded to copper concentrations as low as 20,g/L. When in combination, zinc significantly reduced mortality caused by copper. A novel technique was used to resuspend sediments spiked with four concentrations of three metals (up to 450 ,g/g dry wt of copper, 525 ,g/g dry wt of lead, and 2,035 ,g/g dry wt of zinc). The response of spirorbids to unfiltered suspended sediment solutions and filtered solutions (aqueous metal exposure) was measured. Suspended sediments were toxic to filter-feeding spirorbids at concentrations approximating those found in contaminated Antarctica areas. Toxicity resulted both from aqueous metals and from metals associated with the suspended sediments, although suspended clean sediments had no impact. To our knowledge, the present study is the first to show that resuspension of contaminated sediments can be an important pathway for toxicity to Antarctic hard substrate organisms. Based on the present results, current sediment-quality guidelines used in the evaluation of Australian sediments may be applicable to Antarctic ecosystems. [source]

European AIDS Clinical Society (EACS) guidelines on the prevention and management of metabolic diseases in HIV,

HIV MEDICINE, Issue 2 2008
JD Lundgren
Background Metabolic diseases are frequently observed in HIV-infected persons and, as the risk of contracting these diseases is age-related, their prevalence will increase in the future as a consequence of the benefits of antiretroviral therapy (ART). Summary of guidelines All HIV-infected persons should be screened at regular intervals for a history of metabolic disease, dyslipidaemia, diabetes mellitus, hypertension and alteration of body composition; cardiovascular risk and renal function should also be assessed. Efforts to prevent cardiovascular disease will vary in intensity depending on an individual's absolute risk of ischaemic heart disease and should be comprehensive in nature. Lifestyle interventions should focus on counselling to stop smoking, modify diet and take regular exercise. A healthy diet, exercise and maintaining normal body weight tend to reduce dyslipidaemia; if not effective, a change of ART should be considered, followed by use of lipid-lowering medication in high-risk patients. A pre-emptive switch from thymidine analogues is recommended to reduce the risk of development or progression of lipoatrophy. Intra-abdominal fat accumulation is best managed by exercise and diet. Prevention and management of type 2 diabetes mellitus and hypertension follow guidelines used in the general population. When using medical interventions to prevent and/or treat metabolic disease(s), impairment of the efficacy of ART should be avoided by considering the possibility of pharmacokinetic interactions and compromised adherence. Specialists in HIV and specialists in metabolic diseases should consult each other, in particular in difficult-to-treat cases. Conclusion Multiple and relatively simple approaches exist to prevent metabolic diseases in HIV-infected persons; priority should be given to patients at high risk of contracting these diseases. [source]

Are guidelines on use of colony-stimulating factors in solid cancers flawed?

I. E. Haines
Abstract In cancer care in Australia, we are very reliant on an array of expensive pharmaceuticals. Our use of these treatments is often based on multinational or foreign clinical studies. Oncologists are, to varying degrees, reliant on how the studies are interpreted by the writers of journal editorials, clinical guidelines and opinion pieces. Therefore it is important that these guidelines are balanced and evidence based. We have examined in detail one of the most influential and wide ranging clinical guidelines used in oncology, The American Society of Clinical Oncology (ASCO) 2006 Update of Recommendations for the use of White Blood Cell Factors: An Evidence-Based Clinical Practice Guideline. We have discussed in detail some of the controversial recommendations in this guideline and have exposed what we believe are some flaws in these recommendations. We would urge that we continue to be rigorous in our oversight of international research agendas and international clinical guidelines in the future. [source]

Palliation in cancer of the oesophagus , what passes down an oesophageal stent?

A. Holdoway
Introduction: Self-expanding metal stents are becoming an increasingly popular method of palliation of dysphagia in advanced oesophageal carcinoma. Approximately 10% require intervention post-placement because of blockage (Angorn, 1981). This could be prevented by effective dietary advice. We set out to write evidence-based dietary guidelines for patients undergoing oesophageal stent insertion. A comprehensive literature search failed to identify evidence to support the present guidelines used by manufacturers and dietitians on foods allowed or to avoid and the use of fizzy drinks to ,clean' the stent. Only reference on the ability to consume a semi-solid or solid diet was made (Nedin, 2002). We therefore tested the ability of 50 foods to pass through a stent and the efficacy of fizzy water in unblocking an occluded stent. Method: Normal mouthfuls of raw and cooked, peeled/unpeeled fruit and vegetables, casseroles, griddle or grilled plain meat, poultry or fish, eggs, nuts, dried fruit and bread in various forms were tested. An adult female chewed a ,normal' mouthful of each test food and at the point of swallowing the bolus of food was passed into an expanded Ultraflex metal covered stent (internal diameter 18 mm). If occlusion occurred, water was dribbled through the stent, simulating swallowing fluid, in an attempt to unblock the stent. If the occlusion remained, the stent was agitated to mimic advice given about moving around to unblock a stent in a patient. If it remained occluded, a smaller amount of food, approximately half a mouthful, was chewed for twice as long and re-tested. To test the efficacy of fizzy water to clear an occlusion, we compared the ability of water, warm water and fizzy water to unblock a stent artificially occluded with a bolus of bread. Results: Foods that occluded the stent but passed through if eaten in half mouthfuls and chewed for twice normal chewing time included sandwiches, dry toast, apple, tinned pineapple, fresh orange segments with pith removed, up to six sultanas, chopped dried apricot, boiled egg, muesli, meat and poultry. Dry meat, fruit with pith, skins of capsicum peppers and tomatoes, more than seven sultanas and dried apricots caused occlusion. Nuts and vegetables such as lettuce, which are cited in many diet sheets as items to avoid (Nedin, 2002), passed through the stent when chewed to a normal level. The volumes of fluid required to unblock a stent occluded with bread were 5 l of fizzy water, 3.5 l of cold water or 1 l of warm water. Conclusion: If a patient has good dentition and can chew well and take small mouthfuls and prepare and cook food appropriately, it is likely that they can enjoy a wide variety of solid foods. The use of fizzy drinks to maintain the patency of the stent in patients prone to reflux is questionable, warm fluids may be more efficacious. Based on these initial findings we are updating our dietary guidelines for patients undergoing oesophageal stent insertion and hope to audit stent occlusion following implementation. [source]