160 research outputs found
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
Measuring agreement between decision support reminders: the cloud vs. the local expert
Oxidative Inactivation of Mitochondrial Aconitase Results in Iron and H2O2-Mediated Neurotoxicity in Rat Primary Mesencephalic Cultures
BACKGROUND:Mitochondrial oxidative stress is a contributing factor in the etiology of numerous neuronal disorders. However, the precise mechanism(s) by which mitochondrial reactive oxygen species (ROS) modify cellular targets to induce the death of neurons remains unknown. The goal of this study was to determine if oxidative inactivation of mitochondrial aconitase (m-aconitase) resulted in the release of redox-active iron (Fe2+) and hydrogen peroxide (H2O2) and whether this contributes to cell death. METHODOLOGY/PRINCIPAL FINDINGS:Incubation of rat primary mesencephalic cultures with the redox cycling herbicide paraquat (PQ2+) resulted in increased production of H2O2 and Fe2+ at times preceding cell death. To confirm the role of m-aconitase as a source of Fenton reagents and death, we overexpressed m-aconitase using an adenoviral construct thereby increasing the target available for inactivation by ROS. Co-labeling studies identified astrocytes as the predominant cell type expressing transduced m-aconitase although neurons were identified as the primary cell type dying. Oxidative inactivation of m-aconitase overexpressing cultures resulted in exacerbation of H2O2 production, Fe2+ accumulation and increased neuronal death. Increased cell death in m-aconitase overexpressing cultures was attenuated by addition of catalase and/or a cell permeable iron chelator suggesting that neuronal death occurred in part via astrocyte-derived H2O2. CONCLUSIONS:These results suggest a role of ROS-sensitive m-aconitase as a source of Fe2+ and H2O2 and as a contributing factor to neurotoxicity
Computerized clinical decision support systems for primary preventive care: A decision-maker-researcher partnership systematic review of effects on process of care and patient outcomes
Health care providers’ perceptions of use and influence of clinical decision support reminders: qualitative study following a randomized trial to improve HPV vaccination rates
Facile Synthesis of Amine-Functionalized Eu3+-Doped La(OH)3 Nanophosphors for Bioimaging
Here, we report a straightforward synthesis process to produce colloidal Eu3+-activated nanophosphors (NPs) for use as bioimaging probes. In this procedure, poly(ethylene glycol) serves as a high-boiling point solvent allowing for nanoscale particle formation as well as a convenient medium for solvent exchange and subsequent surface modification. The La(OH)3:Eu3+ NPs produced by this process were ~3.5 nm in diameter as determined by transmission electron microscopy. The NP surface was coated with aminopropyltriethoxysilane to provide chemical functionality for attachment of biological ligands, improve chemical stability and prevent surface quenching of luminescent centers. Photoluminescence spectroscopy of the NPs displayed emission peaks at 597 and 615 nm (λex = 280 nm). The red emission, due to 5D0 → 7F1 and 5D0 → 7F2 transitions, was linear with concentration as observed by imaging with a conventional bioimaging system. To demonstrate the feasibility of these NPs to serve as optical probes in biological applications, an in vitro experiment was performed with HeLa cells. NP emission was observed in the cells by fluorescence microscopy. In addition, the NPs displayed no cytotoxicity over the course of a 48-h MTT cell viability assay. These results suggest that La(OH)3:Eu3+ NPs possess the potential to serve as a luminescent bioimaging probe
Computerized clinical decision support systems for acute care management: A decision-maker-researcher partnership systematic review of effects on process of care and patient outcomes
<p>Abstract</p> <p>Background</p> <p>Acute medical care often demands timely, accurate decisions in complex situations. Computerized clinical decision support systems (CCDSSs) have many features that could help. However, as for any medical intervention, claims that CCDSSs improve care processes and patient outcomes need to be rigorously assessed. The objective of this review was to systematically review the effects of CCDSSs on process of care and patient outcomes for acute medical care.</p> <p>Methods</p> <p>We conducted a decision-maker-researcher partnership systematic review. MEDLINE, EMBASE, Evidence-Based Medicine Reviews databases (Cochrane Database of Systematic Reviews, DARE, ACP Journal Club, and others), and the Inspec bibliographic database were searched to January 2010, in all languages, for randomized controlled trials (RCTs) of CCDSSs in all clinical areas. We included RCTs that evaluated the effect on process of care or patient outcomes of a CCDSS used for acute medical care compared with care provided without a CCDSS. A study was considered to have a positive effect (<it>i.e.</it>, CCDSS showed improvement) if at least 50% of the relevant study outcomes were statistically significantly positive.</p> <p>Results</p> <p>Thirty-six studies met our inclusion criteria for acute medical care. The CCDSS improved process of care in 63% (22/35) of studies, including 64% (9/14) of medication dosing assistants, 82% (9/11) of management assistants using alerts/reminders, 38% (3/8) of management assistants using guidelines/algorithms, and 67% (2/3) of diagnostic assistants. Twenty studies evaluated patient outcomes, of which three (15%) reported improvements, all of which were medication dosing assistants.</p> <p>Conclusion</p> <p>The majority of CCDSSs demonstrated improvements in process of care, but patient outcomes were less likely to be evaluated and far less likely to show positive results.</p
Standing orders for influenza and pneumococcal polysaccharide vaccination: Correlates identified in a national survey of U.S. Primary care physicians
<p>Abstract</p> <p>Background</p> <p>Standing orders programs (SOPs) allow non-physician medical staff to assess eligibility and administer vaccines without a specific physician's order. SOPs increase vaccination rates but are underutilized.</p> <p>Method</p> <p>In 2009, correlates of SOPs use for influenza vaccine and pneumococcal polysaccharide vaccination (PPV) were assessed in a nationally representative, stratified random sample of U.S. physicians (n = 880) in family and internal medicine who provided office immunization. The response rate was 67%. Physicians reporting no SOPs, only influenza SOPs, and joint influenza and PPV SOPs were compared using multinomial and logistic regression models to examine individual and practice-level correlates.</p> <p>Results</p> <p>23% reported using SOPs consistently for both influenza vaccine and PPV, and 20% for influenza vaccination only, with the remainder not using SOPs. Practice-level factors that distinguished practices with joint influenza-PPV SOPs included perceived practice openness to change, strong practice teamwork, access to an electronic medical record, presence of an immunization champion in the practice, and access to nurse/physician assistant staff as opposed to medical assistants alone.</p> <p>Discussion</p> <p>Physicians in practices with SOPs for both vaccines reported greater awareness of ACIP recommendations and/or Medicare regulations and were more likely to agree that SOPs are an effective way to boost vaccination coverage. However, implementation of both influenza and PPV SOPs was also associated with a variety of practice-level factors, including teamwork, the presence of an immunization champion, and greater availability of clinical assistants with advanced training.</p> <p>Conclusions</p> <p>Practice-level factors are critical for the adoption of more complex SOPs, such as joint SOPs for influenza and PPV.</p
- …
