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1.
Nature ; 569(7757): E8, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31065057

RESUMEN

Change history: In Fig. 2b of this Letter, 'Relative wetland change (km2)' should have read 'Relative wetland change (%)' and equations (2) and (3) have been changed from 'RSLRcrit = (m × TRe) × Sed + i' and 'Sedcrit = (RSLR - i)/(m × TRe)', respectively. The definition of the variables in equation (2) has been updated. These errors have been corrected online.

2.
Nature ; 561(7722): 231-234, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30209368

RESUMEN

The response of coastal wetlands to sea-level rise during the twenty-first century remains uncertain. Global-scale projections suggest that between 20 and 90 per cent (for low and high sea-level rise scenarios, respectively) of the present-day coastal wetland area will be lost, which will in turn result in the loss of biodiversity and highly valued ecosystem services1-3. These projections do not necessarily take into account all essential geomorphological4-7 and socio-economic system feedbacks8. Here we present an integrated global modelling approach that considers both the ability of coastal wetlands to build up vertically by sediment accretion, and the accommodation space, namely, the vertical and lateral space available for fine sediments to accumulate and be colonized by wetland vegetation. We use this approach to assess global-scale changes in coastal wetland area in response to global sea-level rise and anthropogenic coastal occupation during the twenty-first century. On the basis of our simulations, we find that, globally, rather than losses, wetland gains of up to 60 per cent of the current area are possible, if more than 37 per cent (our upper estimate for current accommodation space) of coastal wetlands have sufficient accommodation space, and sediment supply remains at present levels. In contrast to previous studies1-3, we project that until 2100, the loss of global coastal wetland area will range between 0 and 30 per cent, assuming no further accommodation space in addition to current levels. Our simulations suggest that the resilience of global wetlands is primarily driven by the availability of accommodation space, which is strongly influenced by the building of anthropogenic infrastructure in the coastal zone and such infrastructure is expected to change over the twenty-first century. Rather than being an inevitable consequence of global sea-level rise, our findings indicate that large-scale loss of coastal wetlands might be avoidable, if sufficient additional accommodation space can be created through careful nature-based adaptation solutions to coastal management.


Asunto(s)
Mapeo Geográfico , Calentamiento Global/estadística & datos numéricos , Modelos Teóricos , Agua de Mar/análisis , Humedales , Calibración , Sedimentos Geológicos/análisis , Actividades Humanas , Internacionalidad
3.
J Environ Manage ; 360: 121184, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38796868

RESUMEN

Forest fertilization with municipal biosolids has been shown to increase tree growth and enhance forest soils. However, there are concerns that nitrogen from the biosolids could impact surface waters through movement from subsurface flow. Here we analyzed data on soil and surface water nitrogen from a working tree plantation that has used biosolids for over three decades to see if there was evidence of N movement through the soil to surface waters. GIS (Geographic Information System) was used to map application units over time and LiDAR (Light Detection and Ranging) was used to delineate watersheds. The program is located in King County Washington with biosolids provided by the King County Wastewater Treatment program. We assembled records to determine if there is any evidence of movement of NO3- through soils or any enrichment in surface waters. While soils show evidence of NO3- enrichment following biosolids application with cumulative loading rates up to 26 Mg ha-1, this is generally limited to the 'A' soil horizon and does not increase linearly with increased biosolids loading rates. There was no indication of increased surface water NO3- concentration relative to biosolids application rates, with a small trend of decreasing water NO3- over time. Surface water NO3- concentration was not correlated with the fraction of the watershed area that had been amended with biosolids, and there was no observable increase in surface water NO3- with increased frequency of biosolids applications to the tree plantations. These results suggest that the current biosolids program is sufficiently protective of ground and surface waters. These observations suggest that biosolids application can be conducted on a large scale with multiple benefits and no discernible impact to surface waters.


Asunto(s)
Bosques , Nitrógeno , Suelo , Nitrógeno/análisis , Suelo/química , Washingtón , Agua , Árboles
4.
Sex Transm Infect ; 99(7): 440-446, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37045586

RESUMEN

OBJECTIVE: The hepatitis C virus (HCV) epidemic among gay, bisexual and other men who have sex with men (GBMSM) is associated with sexual and drug-related behaviours. To stem the tide of HCV infection in GBMSM, regular testing leading to early diagnosis and treatment as prevention is vital. This study aimed to evaluate the success of current HCV testing guidelines from the perspective of GBMSM in four Celtic nations. METHODS: Subpopulation analysis of data from the 2020 cross-sectional online SMMASH3 (social media, men who have sex with men, sexual and holistic health) survey was undertaken to examine HCV testing experiences and sexual behaviours among sexually active GBMSM (n=1886) stratified across three groups: HIV-diagnosed GBMSM (n=124); HIV-negative GBMSM using pre-exposure prophylaxis (PrEP) (n=365); and HIV-negative/untested GBMSM not using PrEP (n=1397). RESULTS: Sexual behaviours associated with HCV acquisition were reported by the majority of HIV-diagnosed (76.6%, n=95) and PrEP-using (93.2%, n=340) GBMSM. Reassuringly, recent testing for HCV in these groups was common, with 79.8% (n=99) and 80.5% (n=294) self-reporting HCV screening within the preceding year, respectively, mostly within sexual health settings. While 54.5% (n=762) of HIV-negative/untested GBMSM not using PrEP reported sexual behaviours associated with HCV, 52.0% had not been screened for HCV in the last year, despite almost half (48.0%, n=190) of unscreened men being in contact with sexual health services in the same period. CONCLUSIONS: Sexual behaviours associated with HCV acquisition among HIV-diagnosed and PrEP-using GBMSM are common but complemented by regular HCV testing within sexual health services. Current testing guidelines for these groups appear to be effective and generally well observed. However, behaviour-based HCV testing for HIV-negative/untested GBMSM not using PrEP appears less effective and may undermine efforts to achieve HCV elimination. Accordingly, we need to increase HCV testing for these men in clinical settings and explore ways to screen those who are not in touch with sexual health services.


Asunto(s)
Infecciones por VIH , Hepatitis C , Profilaxis Pre-Exposición , Minorías Sexuales y de Género , Masculino , Humanos , Homosexualidad Masculina , Estudios Transversales , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Conducta Sexual , Hepatitis C/diagnóstico , Hepatitis C/epidemiología , Hepatitis C/prevención & control , Hepacivirus
5.
J Environ Manage ; 345: 118648, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37506445

RESUMEN

Capturing the value in urban residuals (food scraps and wastewater) is a critical component of urban sustainability and a circular nutrient economy. Food production in urban areas has also been recognized as an important component of urban health. Data from two cities (Seattle and Tacoma, WA) with active resource recovery and community garden programs were used to quantify nutrient recovery and food production potential. Yield data from growth trials conducted using soil amendments produced from locally generated organic residuals were used to model yields in existing urban agriculture programs. Our survey showed much lower than expected volume of food scraps from both residential and multifamily housing for both cities. Nutrient generation rates from food scraps were estimated as 0.55-0.67 kg N and 0.09-0.11 kg P capita-1 yr-1. Recovery rates for Seattle with an established food scrap collection program were 0.21 kg N and 0.006 kg P capita-1 yr-1. Nutrient recovery from wastewater biosolids was higher; 1-1.67 kg N and 0.23-0.76 kg P capita-1 yr-1. Data on effluent quantity and nutrient concentrations from these programs suggests that effluent has a high potential for nutrient recovery (4.03-5 kg N and 0.3-0.5 kg P capita yr-1). Yield was modeled for kale (brassica oleracea) considering the number of people that could be fed per hectare for one year using a 67 g portion by comparing yields from synthetic fertilizer and residuals-based amendments in both high and low quality urban soils. The Tacoma biosolids potting soil yielded enough for 310 and 736 people ha-1 yr-1 for the high and low quality soils, respectively. The modeled food/yard compost produced from the food scraps yielded sufficient kale for 148 to 353 people ha-1 yr-1. Relative yield from fertilizer for the low and high quality soils was 15 and 263 people ha-1yr-1, respectively. Considering yield, enough biosolids are produced to meet 6.7-29.2% of the vegetable needs of each city. These results suggest that significant nutrients can be recovered using existing infrastructure. With enhanced nutrient capture from wastewater effluent, sufficient nutrients could be recovered to meet the N and P needs for food crops for the residents of each city.


Asunto(s)
Fertilizantes , Aguas Residuales , Humanos , Ciudades , Washingtón , Biosólidos , Crecimiento Sostenible , Agricultura/métodos , Suelo/química
6.
Camb Q Healthc Ethics ; : 1-9, 2022 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-36511321

RESUMEN

After a brief overview of ethical issues in an Australian context catalyzed by the current pandemic, this article focuses on data protection in the light of recent debates about COVID-19 data tracking in Australia and globally. This article looks at the issue of trust as a fundamental principle of effective and ethical COVID-safe measures undertaken by the government. Key to ensuring such trust are Habermasian participatory dialogs, which assume trust as a condition of authentic illocution, and an emphasis on short-term data capture.

7.
J Ment Health ; 31(1): 139-146, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32909854

RESUMEN

BACKGROUND: Numerous studies have explored the concept of 'professionalism' in medicine, yet little attention has been paid to the concept in a mental health services context. AIMS: This study sought to determine how the lived experience of patients, carers and healthcare professionals in mental health services align with medically defined, generic, professionalism standards. METHOD: Interviews and focus groups were conducted with patients, carers, nurses, occupational therapists, psychiatrists and psychologists. A framework analysis approach was used to analyse the data, based on the 'Improving Selection to the Foundation Programmes' Professional Attributes Framework. RESULTS: Fifty-six individuals participated. Data aligned to all nine attributes of the Professional Attributes Framework, however the expectations within each attribute varied from that originally cited. A tenth attribute was devised during the process of analysis; Working with Carers. This attribute acknowledges the need to liaise with, and support carers in mental health services. Situational examples included both online and offline behaviours and the topic of 'black humour' emerged. CONCLUSIONS: Compared to a conventional medical definition of professionalism, additional themes and differing emphases were observed for mental health and learning disability services. These findings should be used to inform the teaching and evaluation of professionalism, especially for staff pursuing mental health service careers.


Asunto(s)
Cuidadores , Servicios de Salud Mental , Personal de Salud , Humanos , Motivación , Profesionalismo
8.
Nature ; 2020 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-32710007
9.
J Environ Manage ; 295: 113115, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34167053

RESUMEN

Municipal biosolids are commonly used to fertilize Douglas fir (Pseudotsuga menziesii) plantations in the Pacific Northwest. An intensive soil sampling was conducted to quantify the effects of long-term biosolids application on soil carbon, nitrogen and bulk density for forest soils. This information was used to calculate a carbon balance for biosolids use in commercial tree plantations. Paired control and treated sites on two soil series (Klaus and Tokul) were included with samples collected to a 30 cm depth. A significant decrease in bulk density for two depths, but no changes in total C or N were observed in the Klaus soil. In the Tokul soil, biosolids fertilization increased C storage (total C * bulk density) for three of the four measured depths, resulting in an increase in total C from 112.8 Mg C ha-1 to 172 Mg C ha-1 for the 0-30 cm depth. A comparable increase in N was observed, with significant increases in N storage for all measured depths. The C balance considered fuel use associated with transport and application as costs. The fertilizer (N and P) content of the biosolids and changes in soil C were considered as credits. The balance showed net sequestration for both soil series. Carbon benefits for the Klaus soil totaled -0.2 Mg CO2 per Mg biosolids. Benefits in the Tokul soil totaled -5.15 Mg CO2 per Mg biosolids. Based on diameter at breast height (DBH) biosolids use also resulted in increased tree growth for both soil series. However, differences in stand age and stocking rate complicated interpretation of these results.


Asunto(s)
Carbono , Pseudotsuga , Biosólidos , Carbono/análisis , Fertilizantes , Noroeste de Estados Unidos , Suelo
10.
Nature ; 572(7769): 312, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31409935
11.
Camb Q Healthc Ethics ; 29(1): 115-121, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31858938

RESUMEN

This article considers recent ethical topics relating to medical AI. After a general discussion of recent medical AI innovations, and a more analytic look at related ethical issues such as data privacy, physician dependency on poorly understood AI helpware, bias in data used to create algorithms post-GDPR, and changes to the patient-physician relationship, the article examines the issue of so-called robot doctors. Whereas the so-called democratization of healthcare due to health wearables and increased access to medical information might suggest a positive shift in the patient-physician relationship, the physician's 'need to care' might be irreplaceable, and robot healthcare workers ('robot carers') might be seen as contributing to dehumanized healthcare practices.


Asunto(s)
Inteligencia Artificial/ética , Ética Médica , Relaciones Médico-Paciente , Inteligencia Artificial/legislación & jurisprudencia , Confidencialidad/ética , Unión Europea , Humanos , Consentimiento Informado , Médicos , Robótica/ética , Robótica/legislación & jurisprudencia
12.
BMC Public Health ; 19(1): 992, 2019 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-31340797

RESUMEN

BACKGROUND: Chlamydia trachomatis (C. trachomatis) is the most common bacterial sexually transmitted infection in the UK. Recent studies suggest that in addition to the genital tract, C. trachomatis is found in the throat and rectum, suggesting the number of infections is under-reported. There is an urgent need to study the impact of extending diagnosis to include extra-genital samples; however, there is a lack of evidence on the acceptability of asking young women to provide these samples. METHOD: A mixed methods single group feasibility study explored the acceptability of combined genital and extra-genital testing in young women aged 16-25 years consecutively attending a sexual health centre in Edinburgh, Scotland. Young women were asked to complete a self- administered anonymous questionnaire whether they would be willing to give self-taken throat and ano-rectal samples. Interviews with women (n = 20) willing to self-sample were conducted before and after self-sampling, and these explored the underlying reasons behind their decision, and feelings about the tests. RESULTS: Of 500 women recruited to the study, 422 (84.4%) women provided sufficient data for analysis. From completed questionnaires, 86.3% of respondents reported willingness to self-sample from the throat. Willingness of ano-rectal self-sampling was lower (59.1%), particularly in women under 20 (< 20 years: 44.4%; ≥20 years, 68.2%). Willingness of ano-rectal self-sampling was higher in women who had more sexual partners in the last 6 months (0 partners, 48.3%, n = 14, 3 or more partners, 67.4%, n = 60) and in those who have previous experience of a positive test for a sexually transmitted infection (STI) (positive: 64.5%; negative: 57%). Interviewed women suggested that a lack of knowledge of STIs, embarrassment and lack of confidence in the ability to carry out the sampling were barriers towards acceptability. CONCLUSIONS: In this study, self-sampling of throat samples is largely acceptable; however, the acceptability of taking an ano-rectal sample for C. trachomatis testing in young women was lower in younger women. The study suggests further research to investigate the acceptability of extra-genital testing as an addition to routine C. trachomatis testing, and whether this increases detection and prevents infective sequelae for women.


Asunto(s)
Infecciones por Chlamydia/diagnóstico , Infecciones por Chlamydia/psicología , Conocimientos, Actitudes y Práctica en Salud , Tamizaje Masivo/psicología , Aceptación de la Atención de Salud/psicología , Adolescente , Adulto , Chlamydia trachomatis , Estudios de Factibilidad , Femenino , Humanos , Tamizaje Masivo/métodos , Escocia , Conducta Sexual/psicología , Parejas Sexuales/psicología , Enfermedades de Transmisión Sexual/psicología , Encuestas y Cuestionarios , Adulto Joven
13.
Sociol Health Illn ; 41(6): 1071-1087, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30908680

RESUMEN

Using data collected through semi-structured interviews and focus group discussions with 37 adult men living in Brunei Darussalam, this paper explores how masculinities and expectations about male roles across the life course influence men's perceptions, of and attitudes towards health and health help-seeking behaviour. Bruneian men gave accounts that consistently spoke of a series of masculine roles and associated attributes and behaviours, which mapped across the life course. Men described health and the steps that they had taken to protect their health in terms of responsibilities associated with being a breadwinner, provider of support for parents, role model and leader of the family. Whilst adherence to Bruneian norms about masculinity could obstruct men's engagement with health help-seeking, we also found that men mobilised their understanding of Bruneian masculinity such that it provided culturally legitimate way of engaging in health help-seeking. We conclude by considering implications for further development of conceptualisations of masculinities, particularly responding to the call to consider Connell's theory of 'hegemonic masculinity' in the context of the Global South. We also consider the implications of the findings of this research for policy and practice in provision of health promotion and services in Brunei.


Asunto(s)
Masculinidad , Salud del Hombre , Aceptación de la Atención de Salud , Adulto , Brunei , Grupos Focales , Teoría Fundamentada , Humanos , Entrevistas como Asunto , Masculino , Conducta Social
14.
Philos Trans A Math Phys Eng Sci ; 376(2119)2018 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-29610380

RESUMEN

The effectiveness of stringent climate stabilization scenarios for coastal areas in terms of reduction of impacts/adaptation needs and wider policy implications has received little attention. Here we use the Warming Acidification and Sea Level Projector Earth systems model to calculate large ensembles of global sea-level rise (SLR) and ocean pH projections to 2300 for 1.5°C and 2.0°C stabilization scenarios, and a reference unmitigated RCP8.5 scenario. The potential consequences of these projections are then considered for global coastal flooding, small islands, deltas, coastal cities and coastal ecology. Under both stabilization scenarios, global mean ocean pH (and temperature) stabilize within a century. This implies significant ecosystem impacts are avoided, but detailed quantification is lacking, reflecting scientific uncertainty. By contrast, SLR is only slowed and continues to 2300 (and beyond). Hence, while coastal impacts due to SLR are reduced significantly by climate stabilization, especially after 2100, potential impacts continue to grow for centuries. SLR in 2300 under both stabilization scenarios exceeds unmitigated SLR in 2100. Therefore, adaptation remains essential in densely populated and economically important coastal areas under climate stabilization. Given the multiple adaptation steps that this will require, an adaptation pathways approach has merits for coastal areas.This article is part of the theme issue 'The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.

15.
J Environ Qual ; 47(6): 1504-1512, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30512065

RESUMEN

This study examined the impact of soil filtration on water quality for reclaimed water from two municipal wastewater treatment processes with two soils (forest and farm). Soils were watered for 16 wk. Nutrients (NO-N, NH-N, and PO), electrical conductivity, hardness, pH, total metals, and estrogenic activity in source and effluents were measured. Results were evaluated in reference to current regulations in Washington State. Both reclaimed waters met standards for unrestricted agricultural use but did not meet current state regulations for ecological use. Metal concentrations in reclaimed waters were generally similar to the control (tap water). Both source and soil filtered water met Washington State stream water criteria for chronic exposure for As but exceeded groundwater standards. Concentrations of Cd, Pb, Ag, and Zn in the effluents were similar or slightly elevated to reclaimed source water for both soils and water types. Soil filtration improved water quality to levels within Washington State regulatory limits for ecological use for Cd, Cu, and Zn but decreased water quality for Pb for both soil and reclaimed water types. Phosphate concentrations were reduced by soil filtration, but NO concentrations were increased for both soils and all water types above source water concentrations. The estrogenic activity of the sand-filtered water decreased to near detection limits in the forest soil and by >200% in the farm soil. The degradation in water quality (increased NO, As, and Mn) after soil filtration observed in this study would likely occur with any water type, including rainwater.


Asunto(s)
Estrógenos/análisis , Metales Pesados/análisis , Contaminantes del Suelo/análisis , Eliminación de Residuos Líquidos/métodos , Monitoreo del Ambiente , Filtración , Nitrógeno/análisis , Fósforo/análisis , Suelo/química
16.
Camb Q Healthc Ethics ; 27(3): 440-446, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29845915

RESUMEN

This article considers recent ethical topics in Australia relating to the health rights of children in the contexts of (1) detention centers, (2) vaccination, and (3) procreative liberty, within a wider framework of discussion of the competing rights of society, parents, the child, and future generations.


Asunto(s)
Protección a la Infancia/ética , Eticistas , Derechos Humanos , Australia , Preescolar , Libertad , Humanos , Padres , Vacunación
17.
Environ Sci Technol ; 51(10): 5360-5367, 2017 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-28414913

RESUMEN

This study reviewed 147 life cycle studies, with 28 found suitable for harmonizing food waste management methods' climate and energy impacts. A total of 80 scientific soil productivity studies were assessed to rank management method soil benefits. Harmonized climate impacts per kilogram of food waste range from -0.20 kg of carbon dioxide equivalents (CO2e) for anaerobic digestion (AD) to 0.38 kg of CO2e for landfill gas-to-energy (LFGTE). Aerobic composting (AC) emits -0.10 kg of CO2e. In-sink grinding (ISG) via a food-waste disposer and flushing for management with other sewage at a wastewater treatment plant emits 0.10 kg of CO2e. Harmonization reduced climate emissions versus nonharmonized averages. Harmonized energy impacts range from -0.32 MJ for ISG to 1.14 MJ for AC. AD at 0.27 MJ and LFGTE at 0.40 MJ fall in between. Rankings based on soil studies show AC first for carbon storage and water conservation, with AD second. AD first for fertilizer replacement, with AC second, and AC and AD tied for first for plant yield increase. ISG ranks third and LFGTE fourth on all four soil-quality and productivity indicators. Suggestions for further research include developing soil benefits measurement methods and resolving inconsistencies in the results between life-cycle assessments and soil science studies.


Asunto(s)
Alimentos , Instalaciones de Eliminación de Residuos , Administración de Residuos , Dióxido de Carbono , Suelo
18.
J Environ Qual ; 46(5): 1098-1105, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28991987

RESUMEN

The phosphorus saturation index (PSI) and P saturation ratio (PSR) were tested across a wide range of bioretention soil mixtures (BSMs) for their relationship to total and dissolved P in column leachate. The BSMs tested were made using different feedstocks including sand alone, food and yard waste compost, biosolids and yard compost, and high Fe biosolids. The PSI of the mixtures ranged from 0.23 ± 0.03 (biosolids and yard waste compost 15%, oyster shells 5%) to 1.26 ± 0.02 (biosolids and yard waste compost 80%). The PSR of the mixtures ranged from 0.05 ± 0 (100% sand) to 3.12 ± 0.12 (biosolids and yard waste compost 80%). A total of 12 storm events were staged using both synthetic rainwater (total P = 1.71 ± 0.3 mg L) and actual stormwater (total P = 0.08 ± 0.03 mg L). Excluding the sand-only mixture, all treatments were a source of P for the duration of the study. However both total and dissolved P concentrations decreased over time. Effluent concentrations of total P in the first event ranged from 0.59 to 75.55 mg L but decreased by the final event to between 0.15 and 10.73 mg L. The PSR was found to be a good predictor of P leaching from all BSMs with an of 0.73 for total mass of P leached across all leaching events. The PSI was a poor predictor ( < 0.3). The PSR also predicted total P in leachate for individual events more effectively than the PSI. Total P in the BSMs had no relationship to P in the leachate.


Asunto(s)
Fósforo/química , Instalaciones de Eliminación de Residuos , Dióxido de Silicio , Suelo , Contaminantes del Suelo , Movimientos del Agua
19.
Environ Microbiol ; 18(6): 1918-29, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26526405

RESUMEN

Application of nitrogen fertilizer has altered terrestrial ecosystems. Ammonia is nitrified by ammonia and nitrite-oxidizing microorganisms, converting ammonia to highly mobile nitrate, contributing to the loss of nitrogen, soil nutrients and production of detrimental nitrogen oxides. Mitigating these costs is of critical importance to a growing bioenergy industry. To resolve the impact of management on nitrifying populations, amplicon sequencing of markers associated with ammonia and nitrite-oxidizing taxa (ammonia monooxygenase-amoA, nitrite oxidoreductase-nxrB, respectively) was conducted from long-term managed and nearby native soils in Eastern Washington, USA. Native nitrifier population structure was altered profoundly by management. The native ammonia-oxidizing archaeal community (comprised primarily by Nitrososphaera sister subclusters 1.1 and 2) was displaced by populations of Nitrosopumilus, Nitrosotalea and different assemblages of Nitrososphaera (subcluster 1.1, and unassociated lineages of Nitrososphaera). A displacement of ammonia-oxidizing bacterial taxa was associated with management, with native groups of Nitrosospira (cluster 2 related, cluster 3A.2) displaced by Nitrosospira clusters 8B and 3A.1. A shift in nitrite-oxidizing bacteria (NOB) was correlated with management, but distribution patterns could not be linked exclusively to management. Dominant nxrB sequences displayed only distant relationships to other NOB isolates and environmental clones.


Asunto(s)
Archaea/aislamiento & purificación , Bacterias/aislamiento & purificación , Nitritos/metabolismo , Microbiología del Suelo , Agricultura , Amoníaco/metabolismo , Archaea/clasificación , Archaea/genética , Archaea/metabolismo , Bacterias/clasificación , Bacterias/genética , Bacterias/metabolismo , Ecología , Ecosistema , Fertilizantes , Nitrificación , Oxidación-Reducción , Filogenia , Suelo/química , Washingtón
20.
J Environ Qual ; 45(1): 26-36, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26828157

RESUMEN

Urban agriculture is growing in cities across the United States. It has the potential to provide multiple benefits, including increased food security. Concerns about soil contamination in urban areas can be an impediment to urban agriculture. Lead is the most common contaminant in urban areas. In this paper, direct (soil ingestion via outdoor and indoor exposure) and indirect (consumption of food grown in Pb-contaminated soils) exposure pathways are reviewed. It is highly unlikely that urban agriculture will increase incidences of elevated blood Pb for children in urban areas. This is due to the high likelihood that agriculture will improve soils in urban areas, resulting in reduced bioavailability of soil Pb and reduced fugitive dust. Plant uptake of Pb is also typically very low. The exceptions are low-growing leafy crops where soil-splash particle contamination is more likely and expanded hypocotyl root vegetables (e.g., carrot). However, even with higher bioaccumulation factors, it is not clear that the Pb in root vegetables or any other crops will be absorbed after eating. Studies have shown limited absorption of Pb when ingested with food. Best management practices to assure minimal potential for exposure are also common practices in urban gardens. These include the use of residuals-based composts and soil amendments and attention to keeping soil out of homes. This review suggests that benefits associated with urban agriculture far outweigh any risks posed by elevated soil Pb.


Asunto(s)
Agricultura , Plomo/análisis , Contaminantes del Suelo/análisis , Ciudades , Humanos , Suelo
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