191 research outputs found
Control of hyperglycaemia in paediatric intensive care (CHiP): study protocol.
BACKGROUND: There is increasing evidence that tight blood glucose (BG) control improves outcomes in critically ill adults. Children show similar hyperglycaemic responses to surgery or critical illness. However it is not known whether tight control will benefit children given maturational differences and different disease spectrum. METHODS/DESIGN: The study is an randomised open trial with two parallel groups to assess whether, for children undergoing intensive care in the UK aged <or= 16 years who are ventilated, have an arterial line in-situ and are receiving vasoactive support following injury, major surgery or in association with critical illness in whom it is anticipated such treatment will be required to continue for at least 12 hours, tight control will increase the numbers of days alive and free of mechanical ventilation at 30 days, and lead to improvement in a range of complications associated with intensive care treatment and be cost effective. Children in the tight control group will receive insulin by intravenous infusion titrated to maintain BG between 4 and 7.0 mmol/l. Children in the control group will be treated according to a standard current approach to BG management. Children will be followed up to determine vital status and healthcare resources usage between discharge and 12 months post-randomisation. Information regarding overall health status, global neurological outcome, attention and behavioural status will be sought from a subgroup with traumatic brain injury (TBI). A difference of 2 days in the number of ventilator-free days within the first 30 days post-randomisation is considered clinically important. Conservatively assuming a standard deviation of a week across both trial arms, a type I error of 1% (2-sided test), and allowing for non-compliance, a total sample size of 1000 patients would have 90% power to detect this difference. To detect effect differences between cardiac and non-cardiac patients, a target sample size of 1500 is required. An economic evaluation will assess whether the costs of achieving tight BG control are justified by subsequent reductions in hospitalisation costs. DISCUSSION: The relevance of tight glycaemic control in this population needs to be assessed formally before being accepted into standard practice
Hyperdominance in the Amazonian tree flora
The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees. Most of these are habitat specialists and only dominant in one or two regions of the basin. We discuss some implications of the finding that a small group of species--less diverse than the North American tree flora--accounts for half of the world's most diverse tree community.This work was
supported by Alberta Mennega Stichting; ALCOA Suriname;
Banco de la República; Center for Agricultural Research in
Suriname; Coordenação de Aperfeiçoamento de Pessoal de
Nível Superior (Plano Nacional de Pós-Graduação); Conselho
Nacional de Desenvovimento Científico e Tecnológico of Brazil
(CNPq) projects Programa de Pesquisas Ecológicas de Longa
Duração (PELD) (558069/2009-6), Programa de Apoio a
Núcleos de Excelência da Fundação de Amparo à Pesquisa
do Estado do Amazonas (PRONEX-FAPEAM) (1600/2006), Áreas
Úmidas, and MAUA; PELD (403792/2012-6), PPBio, CENBAM,
Universal (479599/2008-4), and Universal 307807-2009-6;
Fundação de Amparo À Pesquisa Do Estado Do Amazonas
(APEAM) projects DCR/2006, Hidroveg with FAPESP, and
PRONEX with CNPq; FAPESP; Colciencias; Duke University;
Ecopetrol; FEPIM 044/2003; the Field Museum; Conservation
International/DC (TEAM/INPA Manuas), Gordon and Betty
Moore Foundation; Guyana Forestry Commission; Investissement
d’Avenir grant of the French Agence Nationale de la Recherche
(ANR) (Centre d’Étude de la Biodiversité Amazonienne
ANR-10-LABX-0025); Margaret Mee Amazon Trust; Miquel
fonds; National Geographic Society (7754-04, 8047-06 to
P.M.J.); Netherlands Foundation for the Advancement of
Tropical Research WOTRO grants WB85- 335 and W84-581;
Primate Conservation Incorporated; Programme Ecosystèmes
Tropicaux (French Ministry of Ecology and Sustainable
Development; Shell Prospecting and Development Peru;
Smithsonian Institution’s Biological Diversity of the Guiana
Shield Program; Stichting het van Eeden-fonds; the Body
Shop; the Ministry of the Environment of Ecuador;
TROBIT; Tropenbos International; NSF (NSF-0743457 and
NSF-0101775 to P.M.J.); USAID; Variety Woods Guyana;
WWF-Brazil; WWF-Guianas; XIIéme Contrat de Plan Etat
Région-Guyane (French Government and European Union); and
grants to RAINFOR from the European Union, UK Natural
Environment Research Council, the Gordon and Betty Moore
Foundation, and U.S. National Geographic Society. O.L.P. is
supported by a European Research Council Advanced Grant and a
Royal Society Wolfson Research Merit Award
Seasonal drought limits tree species across the Neotropics
Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on the physiological processes of most tree species. This process implies that the range limits of taxa are defined by their ability to occur under dry conditions, and thus in terms of species distributions it predicts a nested pattern of taxa distribution from wet to dry areas. However, this ‘dry-tolerance’ hypothesis has yet to be adequately tested at large spatial and taxonomic scales. Here, using a dataset of 531 inventory plots of closed canopy forest distributed across the Western Neotropics we investigated how precipitation, evaluated both as mean annual precipitation and as the maximum climatological water deficit, influences the distribution of tropical tree species, genera and families. We find that the distributions of tree taxa are indeed nested along precipitation gradients in the western Neotropics. Taxa tolerant to seasonal drought are disproportionally widespread across the precipitation gradient, with most reaching even the wettest climates sampled; however, most taxa analysed are restricted to wet areas. Our results suggest that the ‘dry tolerance’ hypothesis has broad applicability in the world's most species-rich forests. In addition, the large number of species restricted to wetter conditions strongly indicates that an increased frequency of drought could severely threaten biodiversity in this region. Overall, this study establishes a baseline for exploring how tropical forest tree composition may change in response to current and future environmental changes in this region
Estimating the global conservation status of more than 15,000 Amazonian tree species
Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century
Seasonal drought limits tree species across the Neotropics
AcceptedArticle in Press© 2016 Nordic Society Oikos.Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on the physiological processes of most tree species. This implies that the range limits of taxa are defined by their ability to occur under dry conditions, and thus in terms of species distributions predicts a nested pattern of taxa distribution from wet to dry areas. However, this 'dry-tolerance' hypothesis has yet to be adequately tested at large spatial and taxonomic scales. Here, using a dataset of 531 inventory plots of closed canopy forest distributed across the western Neotropics we investigated how precipitation, evaluated both as mean annual precipitation and as the maximum climatological water deficit, influences the distribution of tropical tree species, genera and families. We find that the distributions of tree taxa are indeed nested along precipitation gradients in the western Neotropics. Taxa tolerant to seasonal drought are disproportionally widespread across the precipitation gradient, with most reaching even the wettest climates sampled; however, most taxa analysed are restricted to wet areas. Our results suggest that the 'dry tolerance' hypothesis has broad applicability in the world's most species-rich forests. In addition, the large number of species restricted to wetter conditions strongly indicates that an increased frequency of drought could severely threaten biodiversity in this region. Overall, this study establishes a baseline for exploring how tropical forest tree composition may change in response to current and future environmental changes in this region.This paper is a product of the RAINFOR and ATDN networks and of ForestPlots.net
researchers (http://www.forestplots.net). RAINFOR and ForestPlots have been
supported by a Gordon and Betty Moore Foundation grant, the European Union’s
Seventh Framework Programme (283080, ‘GEOCARBON’; 282664,
‘AMAZALERT’); European Research Council (ERC) grant ‘Tropical Forests in the
Changing Earth System’ (T-FORCES), and Natural Environment Research Council
(NERC) Urgency Grant and NERC Consortium Grants ‘AMAZONICA’
(NE/F005806/1) and ‘TROBIT’ (NE/D005590/1). Additional funding for fieldwork was
provided by Tropical Ecology Assessment and Monitoring (TEAM) Network, a
collaboration among Conservation International, the Missouri Botanical Garden, the
Smithsonian Institution, and the Wildlife Conservation Society. A.E.M. receives a PhD
scholarship from the T-FORCES ERC grant. O.L.P. is supported by an ERC Advanced
Grant and a Royal Society Wolfson Research Merit Award. We thank Jon J. Lloyd,
Chronis Tzedakis, David Galbraith, and two anonymous reviewers for helpful
comments and Dylan Young for helping with the analyses. This study would not be
possible without the extensive contributions of numerous field assistants and rural
communities in the Neotropical forests. Alfredo Alarcón, Patricia Alvarez Loayza,
Plínio Barbosa Camargo, Juan Carlos Licona, Alvaro Cogollo, Massiel Corrales
Medina, Jose Daniel Soto, Gloria Gutierrez, Nestor Jaramillo Jarama, Laura Jessica
Viscarra, Irina Mendoza Polo, Alexander Parada Gutierrez, Guido Pardo, Lourens
Poorter, Adriana Prieto, Freddy Ramirez Arevalo, Agustín Rudas, Rebeca Sibler and
Javier Silva Espejo additionally contributed data to this study though their RAINFOR
participations. We further thank those colleagues no longer with us, Jean Pierre Veillon,
Samuel Almeida, Sandra Patiño and Raimundo Saraiva. Many data come from Alwyn
Gentry, whose example has inspired new generations to investigate the diversity of the
Neotropics
Measuring adherence to antiretroviral treatment in resource-poor settings: The feasibility of collecting routine data for key indicators
<p>Abstract</p> <p>Background</p> <p>An East African survey showed that among the few health facilities that measured adherence to antiretroviral therapy, practices and definitions varied widely. We evaluated the feasibility of collecting routine data to standardize adherence measurement using a draft set of indicators.</p> <p>Methods</p> <p>Targeting 20 facilities each in Ethiopia, Kenya, Rwanda, and Uganda, in each facility we interviewed up to 30 patients, examined 100 patient records, and interviewed staff.</p> <p>Results</p> <p>In 78 facilities, we interviewed a total of 1,631 patients and reviewed 8,282 records. Difficulties in retrieving records prevented data collection in two facilities. Overall, 94.2% of patients reported perfect adherence; dispensed medicine covered 91.1% of days in a six month retrospective period; 13.7% of patients had a gap of more than 30 days in their dispensed medication; 75.8% of patients attended clinic on or before the date of their next appointment; and 87.1% of patients attended within 3 days.</p> <p>In each of the four countries, the facility-specific median indicators ranged from: 97%-100% for perfect self-reported adherence, 90%-95% of days covered by dispensed medicines, 2%-19% of patients with treatment gaps of 30 days or more, and 72%-91% of appointments attended on time. Individual facilities varied considerably.</p> <p>The percentages of days covered by dispensed medicine, patients with more than 95% of days covered, and patients with a gap of 30 days or more were all significantly correlated with the percentages of patients who attended their appointments on time, within 3 days, or within 30 days of their appointment. Self reported recent adherence in exit interviews was significantly correlated only with the percentage of patients who attended within 3 days of their appointment.</p> <p>Conclusions</p> <p>Field tests showed that data to measure adherence can be collected systematically from health facilities in resource-poor settings. The clinical validity of these indicators is assessed in a companion article. Most patients and facilities showed high levels of adherence; however, poor levels of performance in some facilities provide a target for quality improvement efforts.</p
Volume and geographical distribution of ecological research in the Andes and the Amazon, 1995-2008
Applied science facilitates the large-scale expansion of protected areas in an Amazonian hot spot
Meeting international commitments to protect 17% of terrestrial ecosystems worldwide will require \u3e3 million square kilometers of new protected areas and strategies to create those areas in a way that respects local communities and land use. In 2000–2016, biological and social scientists worked to increase the protected proportion of Peru’s largest department via 14 interdisciplinary inventories covering \u3e9 million hectares of this megadiverse corner of the Amazon basin. In each landscape, the strategy was the same: convene diverse partners, identify biological and sociocultural assets, document residents’ use of natural resources, and tailor the findings to the needs of decision-makers. Nine of the 14 landscapes have since been protected (5.7 million hectares of new protected areas), contributing to a quadrupling of conservation coverage in Loreto (from 6 to 23%). We outline the methods and enabling conditions most crucial for successfully applying similar campaigns elsewhere on Earth
Computer-assisted glucose control in critically ill patients
Objective: Intensive insulin therapy is associated with the risk of hypoglycemia and increased costs of material and personnel. We therefore evaluated the safety and efficiency of a computer-assisted glucose control protocol in a large population of critically ill patients. Design and setting: Observational cohort study in three intensive care units (32 beds) in a 1,300-bed university teaching hospital. Patients: All 2,800 patients admitted to the surgical, neurosurgical, and cardiothoracic units; the study period started at each ICU after implementation of Glucose Regulation for Intensive Care Patients (GRIP), a freely available computer-assisted glucose control protocol. Measurements and results: We analysed compliance in relation to recommended insulin pump rates and glucose measurement frequency. Patients were on GRIP-ordered pump rates 97% of time. Median measurement time was 5 min late (IQR 20 min early to 34 min late). Hypoglycemia was uncommon (7% of patients for mild hypoglycemia, <3.5 mmol/l; 0.86% for severe hypoglycemia, <2.2 mmol/l). Our predefined target range (4.0 - 7.5 mmol/l) was reached after a median of 5.6h (IQR 0.2 - 11.8) and maintained for 89% (70 - 100%) of the remaining stay at the ICU. The number of measurements needed was 5.9 (4.8 - 7.3) per patient per day. In-hospital mortality was 10.1%. Conclusions: Our computer-assisted glucose control protocol provides safe and efficient glucose regulation in routine intensive care practice. A low rate of hypoglycemic episodes was achieved with a considerably lower number of glucose measurements than used in most other schemes
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