Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Adv ; 6(36)2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32917614

RESUMO

Global strategies to halt the dual crises of biodiversity loss and climate change are often formulated separately, even though they are interdependent and risk failure if pursued in isolation. The Global Safety Net maps how expanded nature conservation addresses both overarching threats. We identify 50% of the terrestrial realm that, if conserved, would reverse further biodiversity loss, prevent CO2 emissions from land conversion, and enhance natural carbon removal. This framework shows that, beyond the 15.1% land area currently protected, 35.3% of land area is needed to conserve additional sites of particular importance for biodiversity and stabilize the climate. Fifty ecoregions and 20 countries contribute disproportionately to proposed targets. Indigenous lands overlap extensively with the Global Safety Net. Conserving the Global Safety Net could support public health by reducing the potential for zoonotic diseases like COVID-19 from emerging in the future.


Assuntos
Biodiversidade , Mudança Climática , Conservação dos Recursos Naturais/métodos , Clima , Planeta Terra , Ecossistema , Humanos , Saúde Pública
2.
Limnol Oceanogr ; 64(3): 1333-1346, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31741542

RESUMO

Arsenic contamination of lakebed sediments is widespread due to a range of human activities, including herbicide application, waste disposal, mining, and smelter operations. The threat to aquatic ecosystems and human health is dependent on the degree of mobilization from sediments into overlying water columns and exposure of aquatic organisms. We undertook a mechanistic investigation of arsenic cycling in two impacted lakes within the Puget Sound region, a shallow weakly-stratified lake and a deep seasonally-stratified lake, with similar levels of lakebed arsenic contamination. We found that the processes that cycle arsenic between sediments and the water column differed greatly in shallow and deep lakes. In the shallow lake, seasonal temperature increases at the lakebed surface resulted in high porewater arsenic concentrations that drove larger diffusive fluxes of arsenic across the sediment-water interface compared to the deep, stratified lake where the lakebed remained ~10#x00B0;C cooler. Plankton in the shallow lake accumulated up to an order of magnitude more arsenic than plankton in the deep lake due to elevated aqueous arsenic concentrations in oxygenated waters and low phosphate: arsenate ratios in the shallow lake. As a result, strong arsenic mobilization from sediments in the shallow lake was countered by large arsenic sedimentation rates out of the water column driven by plankton settling.

3.
Sci Adv ; 5(4): eaaw2869, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31016243

RESUMO

The Global Deal for Nature (GDN) is a time-bound, science-driven plan to save the diversity and abundance of life on Earth. Pairing the GDN and the Paris Climate Agreement would avoid catastrophic climate change, conserve species, and secure essential ecosystem services. New findings give urgency to this union: Less than half of the terrestrial realm is intact, yet conserving all native ecosystems-coupled with energy transition measures-will be required to remain below a 1.5°C rise in average global temperature. The GDN targets 30% of Earth to be formally protected and an additional 20% designated as climate stabilization areas, by 2030, to stay below 1.5°C. We highlight the 67% of terrestrial ecoregions that can meet 30% protection, thereby reducing extinction threats and carbon emissions from natural reservoirs. Freshwater and marine targets included here extend the GDN to all realms and provide a pathway to ensuring a more livable biosphere.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Planeta Terra , Ecossistema , Modelos Biológicos , Adaptação Fisiológica , Animais , Mudança Climática , Humanos
4.
Sci Total Environ ; 625: 1606-1614, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29996457

RESUMO

Arsenic, a priority Superfund contaminant and carcinogen, is a legacy pollutant impacting aquatic ecosystems in urban lakes downwind of the former ASARCO copper smelter in Ruston, WA, now a Superfund site. We examined the mobility of arsenic from contaminated sediments and arsenic bioaccumulation in phytoplankton and zooplankton in lakes with varying mixing regimes. In lakes with strong seasonal thermal stratification, high aqueous arsenic concentrations were limited to anoxic bottom waters that formed during summer stratification, and arsenic concentrations were low in oxic surface waters. However, in weakly-stratified lakes, the entire water column, including the fully oxic surface waters, had elevated concentrations of arsenic (up to 30µgL-1) during the summer. We found enhanced trophic transfer of arsenic through the base of the aquatic food web in weakly-stratified lakes; plankton in these lakes accumulated up to an order of magnitude more arsenic on multiple sampling days than plankton in stratified lakes with similar levels of contamination. We posit that greater bioaccumulation in weakly-stratified lakes was due to elevated arsenic in oxic waters. Aquatic life primarily inhabits oxic waters and in the oxic water column of weakly-stratified lakes arsenic was speciated as arsenate, which is readily taken up by phytoplankton because of its structural similarities to phosphate. Our study indicates that mobilization of arsenic from lake sediments into overlying oxic water columns in weakly-stratified lakes leads to increased arsenic exposure and uptake at the base of the aquatic food web.


Assuntos
Arsênio/análise , Monitoramento Ambiental , Cadeia Alimentar , Plâncton/química , Poluentes Químicos da Água/análise , Animais , Lagos/química , Zooplâncton/química
5.
Perfusion ; 29(1): 53-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23863493

RESUMO

A 50-year-old man was admitted to the intensive care unit with respiratory failure and shock after suffering a massive overdose of amlodipine, lisinopril and hydrochlorothiazide. Despite mechanical ventilation, vasopressors, calcium gluconate, hyperinsulinemia-euglycemia therapy, methylene blue and intravenous fat emulsion, the patient's respiratory and hemodynamic status deteriorated. Venoarterial extracorporeal membrane oxygenation (ECMO) was initiated to provide cardiopulmonary support in the setting of profound respiratory failure and refractory shock. The patient was placed on ECMO 19 hours after arrival to the hospital, after which vasopressor and ventilatory requirements decreased significantly. The patient was decannulated from ECMO after 8 days and was discharged home after a 56-day hospitalization. Early institution of ECMO should be considered for the management of respiratory failure and refractory shock in the setting of calcium channel blocker overdose when medical therapies are insufficient.


Assuntos
Anlodipino/intoxicação , Oxigenação por Membrana Extracorpórea/métodos , Hidroclorotiazida/intoxicação , Lisinopril/intoxicação , Humanos , Masculino , Pessoa de Meia-Idade , Respiração Artificial , Insuficiência Respiratória/terapia , Resultado do Tratamento
6.
Biomarkers ; 18(3): 196-203, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23557128

RESUMO

CONTEXT: Endothelial function is abnormal in chronic obstructive pulmonary disease (COPD); whether endothelial dysfunction causes COPD is unknown. OBJECTIVE: Test associations of endothelial biomarkers with FEV1 using instrumental variables. METHODS: Among 26 907 participants with spirometry, ICAM-1, P-selectin, E-selectin and endothelin-1 were measured in subsets. RESULTS: ICAM-1 and P-selectin were inversely associated with FEV1 among European-Americans (-29 mL and -34 mL per standard deviation of log-transformed biomarker, p < 0.001), as was endothelin-1 among African-Americans (-22 mL, p = 0.008). Genetically-estimated ICAM-1 and P-selectin were not significantly associated with FEV1. The instrumental variable for endothelin-1 was non-informative. CONCLUSION: Although ICAM-1, P-selectin and endothelin-1 were inversely associated with FEV1, associations for ICAM-1 and P-selectin do not appear causal.


Assuntos
Endotélio Vascular/metabolismo , Expressão Gênica , Pulmão/metabolismo , Doença Pulmonar Obstrutiva Crônica/genética , Biomarcadores/metabolismo , População Negra , Estudos de Coortes , Selectina E/genética , Selectina E/metabolismo , Endotelina-1/genética , Endotelina-1/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Selectina-P/genética , Selectina-P/metabolismo , Doença Pulmonar Obstrutiva Crônica/etnologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Testes de Função Respiratória , Espirometria , População Branca
8.
J Clin Microbiol ; 26(1): 72-8, 1988 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3257763

RESUMO

The measurement of antibody to Haemophilus influenzae type b capsular polysaccharide is important in the study of natural immunity and in the immunogenicity evaluation of H. influenzae type b vaccines. Several radioantigen binding assays (RABA) have been developed to measure H. influenzae type b anticapsular antibody, but recent immunogenicity data obtained with structurally similar vaccines suggest major differences in antibody quantitation in different laboratories. To evaluate interlaboratory variability in the measurement of anticapsular antibody levels, we blindly evaluated a sample of 40 pre- and postimmunization sera by eight RABAs in different laboratories. Evaluation of RABA methods revealed differences in polysaccharide antigens, radiolabeling methods, concentration and volume of antigen and antibody, and other assay methods. The reported results of assays varied significantly between laboratories (up to sixfold differences in geometric means), in part because of differences in assay sensitivity and different proportions of samples having undetectable levels of antibody (0 to 65% of specimens with undetectable levels). After standardizing the limit of sensitivity for all assays (0.125 microgram/ml), the results of all combinations of paired analyses of RABA assays correlated well (r = 0.88 to 0.99) but the geometric mean levels still varied as much as twofold. For individual sera, the differences between paired assays often were substantial (P less than or equal to 0.0001, paired t test), with some results varying as much as 64-fold. Differences were greatest for lower levels of antibody. There was good comparability and interlaboratory reproducibility of some assays but not of others. Intrinsic or extrinsic labeling of the antigen was not a major determinant of comparability. In most instances, the current variation in the quantitation of antibody levels by these assays precludes interassay comparisons. A standardized measurement of antibody needs to be developed to adequately compare results between different H. influenzae type b immunogenicity studies.


Assuntos
Anticorpos Antibacterianos/análise , Vacinas Anti-Haemophilus , Haemophilus influenzae/imunologia , Polissacarídeos Bacterianos/imunologia , Polissacarídeos/imunologia , Radioimunoensaio/normas , Cápsulas Bacterianas , Vacinas Bacterianas/imunologia , Pré-Escolar , Humanos , Lactente , Radioimunoensaio/métodos
9.
Pediatr Infect Dis J ; 6(7): 660-5, 1987 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3497380

RESUMO

The purpose of this study was to evaluate differences in the safety and immunogenicity of Haemophilus influenzae type b (Hib) capsular polysaccharide vaccine produced by two manufacturers (Connaught and Praxis) in children 18 and 24 months of age. Eighty-five children were evaluated in a prospective, double-blind, randomized fashion. Postvaccination antibody concentrations (measured by radioimmunoassay) and response rates were not significantly different between the two manufacturers' vaccines but immunogenicity was significantly less in 18-month-old children (antibody concentration, 0.149 microgram/ml) compared with 24-month-old children (0.838 microgram/ml) (P = 0.001). No significant differences were noted in the safety of the two vaccines. This study suggests that previously observed differences of immunogenicity data between various type b capsular polysaccharide vaccines are due to differences in antibody assays, not in vaccines. Eighteen-month-old children appear to have a relatively poor immune response to type b capsular polysaccharide. Therefore to optimize the benefits of immunization, we suggest children receive this vaccine at 24 months of age.


Assuntos
Anticorpos Antibacterianos/biossíntese , Vacinas Bacterianas/imunologia , Vacinas Anti-Haemophilus , Haemophilus influenzae/imunologia , Polissacarídeos Bacterianos , Fatores Etários , Cápsulas Bacterianas , Vacinas Bacterianas/efeitos adversos , Pré-Escolar , Método Duplo-Cego , Humanos , Lactente , Estudos Prospectivos , Distribuição Aleatória
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...