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2.
Environ Sci Technol ; 52(21): 11995-12009, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30247882

RESUMO

Judicious phosphorus (P) management is a global grand challenge and critical to achieving and maintaining water quality objectives while maintaining food production. The management of point sources has been successful in lowering P inputs to aquatic environments, but more difficult is reducing P discharges associated with diffuse sources, such as nonpoint runoff from agriculture and urban landscapes, as well as P accumulated in soils and sediments. Strategies for effective diffuse-P management are imperative. Many options are currently available, and the most cost-effective and practical choice depends on the local situation. This critical review describes how the metrics of P quantity in kg ha-1 yr-1 and P form can influence decision-making and implementation of diffuse-P management strategies. Quantifying the total available pool of P, and its form, in a system is necessary to inform effective decision-making. The review draws upon a number of " current practice" case studies that span agriculture, cities, and aquatic sectors. These diverse examples from around the world highlight different diffuse-P management approaches, delivered at the source in the catchment watershed or at the aquatic sink. They underscore workable options for achieving water quality improvement and wider P sustainability. The diffuse-P management options discussed in this critical review are transferable to other jurisdictions at the global scale. We demonstrate that P quantity is typically highest and most concentrated at the source, particularly at farm scale. The most cost-effective and practically implementable diffuse-P management options are, therefore, to reduce P use, conserve P, and mitigate P loss at the source. Sequestering and removing P from aquatic sinks involves increasing cost, but is sometimes the most effective choice. Recovery of diffuse-P, while expensive, offers opportunity for the circular economy.


Assuntos
Agricultura , Fósforo , Solo , Qualidade da Água
3.
Proc Natl Acad Sci U S A ; 114(16): 4177-4182, 2017 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-28373560

RESUMO

Managing excess nutrients remains a major obstacle to improving ecosystem service benefits of urban waters. To inform more ecologically based landscape nutrient management, we compared watershed inputs, outputs, and retention for nitrogen (N) and phosphorus (P) in seven subwatersheds of the Mississippi River in St. Paul, Minnesota. Lawn fertilizer and pet waste dominated N and P inputs, respectively, underscoring the importance of household actions in influencing urban watershed nutrient budgets. Watersheds retained only 22% of net P inputs versus 80% of net N inputs (watershed area-weighted averages, where net inputs equal inputs minus biomass removal) despite relatively low P inputs. In contrast to many nonurban watersheds that exhibit high P retention, these urban watersheds have high street density that enhanced transport of P-rich materials from landscapes to stormwater. High P exports in storm drainage networks and yard waste resulted in net P losses in some watersheds. Comparisons of the N/P stoichiometry of net inputs versus storm drain exports implicated denitrification or leaching to groundwater as a likely fate for retained N. Thus, these urban watersheds exported high quantities of N and P, but via contrasting pathways: P was exported primarily via stormwater runoff, contributing to surface water degradation, whereas N losses additionally contribute to groundwater pollution. Consequently, N management and P management require different strategies, with N management focusing on reducing watershed inputs and P management also focusing on reducing P movement from vegetated landscapes to streets and storm drains.


Assuntos
Ecossistema , Nitrogênio/química , Fósforo/química , Poluentes Químicos da Água/química , Poluição da Água , Monitoramento Ambiental , Água Subterrânea , Nitrogênio/análise , Fósforo/análise , Poluentes Químicos da Água/análise
4.
Environ Sci Technol ; 50(13): 6606-20, 2016 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-27214029

RESUMO

Phosphorus (P) is a critical, geographically concentrated, nonrenewable resource necessary to support global food production. In excess (e.g., due to runoff or wastewater discharges), P is also a primary cause of eutrophication. To reconcile the simultaneous shortage and overabundance of P, lost P flows must be recovered and reused, alongside improvements in P-use efficiency. While this motivation is increasingly being recognized, little P recovery is practiced today, as recovered P generally cannot compete with the relatively low cost of mined P. Therefore, P is often captured to prevent its release into the environment without beneficial recovery and reuse. However, additional incentives for P recovery emerge when accounting for the total value of P recovery. This article provides a comprehensive overview of the range of benefits of recovering P from waste streams, i.e., the total value of recovering P. This approach accounts for P products, as well as other assets that are associated with P and can be recovered in parallel, such as energy, nitrogen, metals and minerals, and water. Additionally, P recovery provides valuable services to society and the environment by protecting and improving environmental quality, enhancing efficiency of waste treatment facilities, and improving food security and social equity. The needs to make P recovery a reality are also discussed, including business models, bottlenecks, and policy and education strategies.


Assuntos
Fósforo , Águas Residuárias , Eutrofização , Metais , Nitrogênio
6.
Vet Rec ; 169(21): 562, 2011 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-22102358
8.
Chemosphere ; 84(6): 779-84, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21481910

RESUMO

Achieving better understanding phosphorus (P) flows through urban ecosystems is needed to conserve P, as non-renewable phosphate rock deposits become depleted and the global human population increases. A baseline mass flow analysis (MFA) for P developed for the Twin Cities Watershed (TCW, which includes most of the Minneapolis-St. Paul metropolitan region) showed that most P input was stored in the system (65%) or leaked from it (31%); only 4% was deliberately exported as useful products. In a realistic, comprehensive conservation scenario P input was reduced by 15%; deliberate export of P in the form of sewage sludge, food waste, and landscape waste was 68% of P input. In this scenario, increased deliberate export was accomplished by decreasing leakage (to 9% of input) and storage (to 23% of input). If used as agricultural fertilizer, the deliberately exported P in the conservation scenario would support about half of the food production required by the TCW.


Assuntos
Conservação dos Recursos Naturais/métodos , Fenômenos Ecológicos e Ambientais , Fósforo/análise , Cidades , Meio Ambiente , Monitoramento Ambiental , Poluição Ambiental/estatística & dados numéricos
9.
J Clin Virol ; 43(2): 169-75, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18635392

RESUMO

BACKGROUND: Detection of HBeAg and anti-HBe is valuable for the evaluation and therapeutic management of hepatitis B infection. OBJECTIVES: To determine the clinical performance of the newly CE-approved(a) HBeAg and anti-HBe assays on the fully automated, random access ADVIA Centaur immunoassay system. STUDY DESIGN: Patient samples collected at two sites were used to compare the ADVIA Centaur assays to Abbott AxSYM assays. Consensus of discordant results was reached using Roche Elecsys assays. Additionally, two well-characterized seroconversion panels were evaluated. RESULTS: The ADVIA Centaur HBeAg assay sensitivity was 100% and specificity was 99.5%. The ADVIA Centaur anti-HBe assay sensitivity was 100% and the resolved specificity was 98.2%. Fewer samples required retesting with the ADVIA Centaur assays than with the AxSYM. In two well-characterized seroconversion panels, the ADVIA Centaur anti-HBe assay detected anti-HBe 20-25 days earlier than the AxSYM assay; the ADVIA Centaur and AxSYM HBeAg assays detected HBe reactivity on the same day. CONCLUSIONS: The ADVIA Centaur HBeAg and anti-HBe assays demonstrated good sensitivity and specificity, and thus are suitable for clinical use. Their novel algorithms require reduced retesting, suggesting these assays may be more cost effective.


Assuntos
Anticorpos Anti-Hepatite B/sangue , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/diagnóstico , Hepatite B/diagnóstico , Kit de Reagentes para Diagnóstico , Automação , Hepatite B/imunologia , Hepatite B/virologia , Antígenos E da Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Hepatite B Crônica/imunologia , Hepatite B Crônica/virologia , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Sensibilidade e Especificidade
10.
Health Psychol ; 26(6): 718-27, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18020844

RESUMO

PURPOSE: Given the prevalence of physical inactivity among American adults, convenient, low-cost interventions are strongly indicated. This study determined the 6- and 12-month effectiveness of telephone interventions delivered by health educators or by an automated computer system in promoting physical activity. DESIGN: Initially inactive men and women age 55 years and older (N = 218) in stable health participated. Participants were randomly assigned to human advice, automated advice, or health education control. MEASURES: The validated 7-day physical activity recall interview was used to estimate minutes of moderate to vigorous physical activity. Physical activity differences by experimental arm were verified on a random subsample via accelerometry. RESULTS: Using intention-to-treat analysis, at 6 months, participants in both interventions, although not differing from one another, showed significant improvements in weekly physical activity compared with controls. These differences were generally maintained at 12 months, with both intervention arms remaining above the target of 150 min per week of moderate to vigorous physical activity on average. CONCLUSION: Automated telephone-linked delivery systems represent an effective alternative for delivering physical activity advice to inactive older adults.


Assuntos
Instrução por Computador , Exercício , Educação em Saúde , Telefone , Análise de Variância , Metabolismo Energético , Feminino , Seguimentos , Humanos , Cinetocardiografia , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente
11.
Clin Chim Acta ; 372(1-2): 158-66, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16769045

RESUMO

BACKGROUND: It is important that serological assays detect antibodies to human immunodeficiency virus (HIV) in all infected individuals, including those infected with less prevalent, more diverse subtypes. METHODS: Performance of the ADVIA Centaur HIV 1/O/2 Enhanced (EHIV) Assay was tested on 1344 samples from HIV-positive subjects, 6061 samples from groups at low-risk for HIV infection, and 1042 samples from groups at high-risk for HIV-1 and HIV-2 infection. Results were compared with those of an FDA-approved predicate assay. RESULTS: The ADVIA Centaur EHIV Assay showed good precision with a diagnostic specificity of 99.9% and diagnostic sensitivity of 100%. HIV seroconversion was detected earlier in 6 panels, at the same time in 13 panels and later in only 1 of the panels when compared to the predicate assay, thereby narrowing the window period between infection and antibody detection. Of clinical significance, a blood donor sample that was indeterminate by HIV-1 Western blot and non-reactive by the predicate assay was repeatedly reactive in the ADVIA Centaur Assay and confirmed as positive by HIV-2 immunoblot. CONCLUSIONS: The ADVIA Centaur EHIV Assay is useful as an aid in the diagnosis of individuals infected with HIV-1 and/or HIV-2.


Assuntos
Sorodiagnóstico da AIDS/métodos , HIV-1/isolamento & purificação , HIV-2/isolamento & purificação , Algoritmos , Western Blotting , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Trends Ecol Evol ; 21(4): 192-9, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16701085

RESUMO

Most of the global human population lives in urban areas where biogeochemical cycles are controlled by complex interactions between society and the environment. Urban ecology is an emerging discipline that seeks to understand these interactions, and one of the grand challenges for urban ecologists is to develop models that encompass the myriad influences of people on biogeochemistry. We suggest here that existing models, developed primarily in unmanaged and agricultural ecosystems, work poorly in urban ecosystems because they do not include human biogeochemical controls such as impervious surface proliferation, engineered aqueous flow paths, landscaping choices, and human demographic trends. Incorporating these human controls into biogeochemical models will advance urban ecology and will require enhanced collaborations with engineers and social scientists.


Assuntos
Bioquímica , Ecossistema , Geologia , Urbanização , Fenômenos Bioquímicos , Orçamentos , Fenômenos Geológicos
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