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1.
Epidemiol Infect ; 152: e37, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38250791

RESUMO

To investigate the symptoms of SARS-CoV-2 infection, their dynamics and their discriminatory power for the disease using longitudinally, prospectively collected information reported at the time of their occurrence. We have analysed data from a large phase 3 clinical UK COVID-19 vaccine trial. The alpha variant was the predominant strain. Participants were assessed for SARS-CoV-2 infection via nasal/throat PCR at recruitment, vaccination appointments, and when symptomatic. Statistical techniques were implemented to infer estimates representative of the UK population, accounting for multiple symptomatic episodes associated with one individual. An optimal diagnostic model for SARS-CoV-2 infection was derived. The 4-month prevalence of SARS-CoV-2 was 2.1%; increasing to 19.4% (16.0%-22.7%) in participants reporting loss of appetite and 31.9% (27.1%-36.8%) in those with anosmia/ageusia. The model identified anosmia and/or ageusia, fever, congestion, and cough to be significantly associated with SARS-CoV-2 infection. Symptoms' dynamics were vastly different in the two groups; after a slow start peaking later and lasting longer in PCR+ participants, whilst exhibiting a consistent decline in PCR- participants, with, on average, fewer than 3 days of symptoms reported. Anosmia/ageusia peaked late in confirmed SARS-CoV-2 infection (day 12), indicating a low discrimination power for early disease diagnosis.


Assuntos
Ageusia , COVID-19 , Humanos , Anosmia/epidemiologia , Anosmia/etiologia , COVID-19/diagnóstico , Teste para COVID-19 , Vacinas contra COVID-19 , Estudos Longitudinais , SARS-CoV-2 , Ensaios Clínicos Fase III como Assunto
2.
Int J STD AIDS ; 35(4): 244-253, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38016099

RESUMO

INTRODUCTION: Late diagnosis of HIV is associated with increased morbidity and mortality, and an increased risk of non-infectious comorbidities. On a societal level, late diagnosis leads to higher treatment and healthcare costs and is a major driver of HIV transmission. Despite improvements in other areas of the HIV care pathway, late diagnosis remains an individual and public health concern globally. OBJECTIVE: To examine the barriers to HIV testing and highlight successful strategies to improve prompt diagnosis. This review describes the prevalence of late diagnosis in the UK and discusses key factors that contribute to late diagnosis, including the effect of the COVID-19 pandemic. Late HIV diagnosis is lower in the UK than in most other European countries. In this review, pilot projects and ongoing initiatives that have reduced late diagnosis in the UK are highlighted; moreover, further strategies for improving prompt diagnosis are suggested. CONCLUSIONS: Insufficient testing is the fundamental reason for late HIV diagnosis, with societal, systemic, and individual factors all contributing to inadequate testing. Improving access to testing, removing barriers to health-seeking behaviour, and ensuring all people with HIV indicator conditions are promptly tested are key to reducing the rates of late diagnosis globally.


Assuntos
COVID-19 , Infecções por HIV , Humanos , COVID-19/diagnóstico , COVID-19/epidemiologia , Pandemias/prevenção & controle , Europa (Continente) , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Reino Unido/epidemiologia
4.
Front Cell Infect Microbiol ; 13: 1207313, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37424787

RESUMO

Introduction: The heterogeneity of the immunocompromised population means some individuals may exhibit variable, weak or reduced vaccine-induced immune responses, leaving them poorly protected from COVID-19 disease despite receiving multiple SARS-CoV-2 vaccinations. There is conflicting data on the immunogenicity elicited by multiple vaccinations in immunocompromised groups. The aim of this study was to measure both humoral and cellular vaccine-induced immunity in several immunocompromised cohorts and to compare them to immunocompetent controls. Methods: Cytokine release in peptide-stimulated whole blood, and neutralising antibody and baseline SARS-CoV-2 spike-specific IgG levels in plasma were measured in rheumatology patients (n=29), renal transplant recipients (n=46), people living with HIV (PLWH) (n=27) and immunocompetent participants (n=64) post third or fourth vaccination from just one blood sample. Cytokines were measured by ELISA and multiplex array. Neutralising antibody levels in plasma were determined by a 50% neutralising antibody titre assay and SARS-CoV-2 spike specific IgG levels were quantified by ELISA. Results: In infection negative donors, IFN-γ, IL-2 and neutralising antibody levels were significantly reduced in rheumatology patients (p=0.0014, p=0.0415, p=0.0319, respectively) and renal transplant recipients (p<0.0001, p=0.0005, p<0.0001, respectively) compared to immunocompetent controls, with IgG antibody responses similarly affected. Conversely, cellular and humoral immune responses were not impaired in PLWH, or between individuals from all groups with previous SARS-CoV-2 infections. Discussion: These results suggest that specific subgroups within immunocompromised cohorts could benefit from distinct, personalised immunisation or treatment strategies. Identification of vaccine non-responders could be critical to protect those most at risk.


Assuntos
COVID-19 , Imunidade Humoral , Humanos , Vacinas contra COVID-19 , SARS-CoV-2 , COVID-19/prevenção & controle , Vacinação , Anticorpos Neutralizantes , Anticorpos Antivirais , Citocinas , Imunidade Celular , Imunoglobulina G
5.
J Hazard Mater ; 458: 131932, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37390687

RESUMO

Over the last 50 years, the intense use of agricultural plastic in the form of mulch films has led to an accumulation of plastic in soil, creating a legacy of plastic in agricultural fields. Plastic often contains additives, however it is still largely unknown how these compounds affect soil properties, potentially influencing or masking effects of the plastic itself. Therefore, the aim of this study was to investigate the effects of pure plastics of varying sizes and concentrations, to improve our understanding of plastic-only interactions within soil-plant mesocosms. Maize (Zea mays L.) was grown over eight weeks following the addition of micro and macro low-density polyethylene and polypropylene at increasing concentrations (equivalent to 1, 10, 25, and 50 years mulch film use) and the effects of plastic on key soil and plant properties were measured. We found the effect of both macro and microplastic on soil and plant health is negligible in the short-term (1 to <10 years). However, ≥ 10 years of plastic application for both plastic types and sizes resulted in a clear negative effect on plant growth and microbial biomass. This study provides vital insight into the effect of both macro and microplastics on soil and plant properties.


Assuntos
Plásticos , Polietileno , Biomassa , Agricultura , Solo , Microplásticos , Zea mays , Plantas
6.
Biochar ; 5(1): 33, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37325199

RESUMO

Grasslands (natural, semi-natural and improved) occupy approximately one-third of the terrestrial biosphere and are key for global ecosystem service provision, storing up to 30% of soil organic carbon (SOC). To date, most research on soil carbon (C) sequestration has focused on croplands where the levels of native soil organic matter (SOM) are typically low and significant potential exists to replenish SOM stocks. However, with the renewed push to achieve "net zero" C emissions by 2050, grasslands may offer an additional C store, utilising tools such as biochar. Here, we critically evaluate the potential for biochar as a technology for increasing grassland C stocks, identifying a number of practical, economic, social and legislative challenges that need to be addressed before the widescale adoption of biochar may be achieved. We critically assess the current knowledge within the field of grassland biochar research in the context of ecosystem service provision and provide opinions on the applicability of biochar as an amendment to different types of grassland (improved, semi-improved and unimproved) and the potential effect on ecosystem provision using a range of application techniques in the topsoil and subsoil. We concluded that the key question remains, is it possible for managed grasslands to store more C, without causing a loss in additional ecosystem services? To address this question future research must take a more multidisciplinary and holistic approach when evaluating the potential role of biochar at sequestering C in grasslands to mitigate climate change. Supplementary Information: The online version contains supplementary material available at 10.1007/s42773-023-00232-y.

7.
Br Med Bull ; 147(1): 20-30, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37312594

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) and human immunodeficiency virus (HIV) are intersecting pandemics, with implications for care at an individual and global scale. SOURCES OF DATA: PubMed search with relevant articles and their references reviewed. AREAS OF AGREEMENT: COVID-19 has changed the delivery of care to people living with HIV (PLWH). Vaccines are efficacious and safe for PLWH; patient care for symptomatic COVID-19 is similar to that of people without HIV. AREAS OF CONTROVERSY: It remains unclear whether PLWH experience increased COVID-19-specific mortality. Treatments to reduce severity in early COVID-19 infection lack evidence in PLWH. GROWING POINTS: The effects of the COVID-19 pandemic on HIV-related morbidity and mortality are yet to be seen. COVID-19 epidemiology among PLWH is complicated by changes to the severe acute respiratory syndrome coronavirus 2, population behaviours and vaccine availability. AREAS TIMELY FOR DEVELOPING RESEARCH: Global trends in HIV-related morbidity and mortality should be monitored to appreciate the effects of the COVID-19 pandemic. The benefits of early antiviral and/or neutralizing monoclonal antibody (nMAb) treatment for PLWH and nMAb prophylaxis require investigation.


Assuntos
COVID-19 , Infecções por HIV , Humanos , Antivirais , COVID-19/epidemiologia , COVID-19/terapia , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Pandemias , SARS-CoV-2
8.
PLOS Glob Public Health ; 3(2): e0001053, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36963011

RESUMO

Prior studies suggest that adverse events (AEs) following doses one and two of BNT162b2/Pfizer vaccine are worse in those with a prior history of COVID-19. To establish whether this outcome applies to a third/booster dose, we conducted a survey with 534 healthcare workers (HCW) in Northeast England, who reported AEs following all three doses of BNT162b2/Pfizer vaccine. We also explored AEs associated with concurrent seasonal influenza immunisation, in a subset of 492 HCWs. For all doses of BNT162b2/Pfizer vaccine there was a cluster of systemic AEs that were consistently worse in HCWs with a prior history of COVID-19. AEs were no worse in HCWs who received their third/booster dose within 7 days of the influenza jab, rather than further apart. Gender and the presence of ongoing COVID-19 symptoms (OCS) had no effect on AEs associated with COVID-19 or influenza vaccination, though younger HCWs experienced more AEs overall. Our findings have implications for vaccine hesitancy and immunisation protocols.

9.
Sci Total Environ ; 877: 162947, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36940745

RESUMO

Microplastics (MPs) pollution is becoming one of the most pressing environmental issues globally. MPs in the marine, freshwater and terrestrial environments have been fairly well investigated. However, knowledge of the atmospheric-mediated deposition of MPs within rural environments is limited. Here, we present the results of bulk (dry and wet) atmospheric MPs deposition in a rural region of Quzhou County in the North China Plain (NCP). Samples of MPs in the atmospheric bulk deposition were collected for individual rainfall events over a 12-month period from August 2020 to August 2021. The number and size of MPs from 35 rainfall samples were measured by fluorescence microscopy, while the chemical composition of MPs was identified using micro-Fourier transform infrared spectroscopy (µ-FTIR). The results showed that the atmospheric MPs deposition rate in summer (892-75,421 particles/m2/day) was highest compared to 735-9428, 280-4244 and 86-1347 particles/m2/day in spring, autumn, and winter, respectively. Furthermore, the MPs deposition rates in our study were 1-2 orders of magnitude higher than those in other regions, indicating a higher rate of MPs deposition in the rural region of the NCP. MPs with a diameter of 3-50 µm accounted for 75.6 %, 78.4 %, 73.4 % and 66.1 % of total MPs deposition in spring, summer, autumn, and winter, respectively, showing that the majority of MPs in the current study were small in size. Rayon fibers accounted for the largest proportion (32 %) of all MPs, followed by polyethylene terephthalate (12 %) and polyethylene (8 %). This study also found that a significant positive correlation between rainfall volume and MPs deposition rate. In addition, HYSPLIT back-trajectory modelling showed that the farthest source of deposition MPs may have come from Russia.

10.
Lancet HIV ; 10(3): e195-e201, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36610439

RESUMO

Getting to Zero is a commonly cited strategic aim to reduce mortality due to both HIV and avoidable deaths among people with HIV. However, no clear definitions are attached to these aims with regard to what constitutes HIV-related or preventable mortality, and their ambition is limited. This Position Paper presents consensus recommendations to define preventable HIV-related mortality for a pragmatic approach to public health monitoring by use of national HIV surveillance data. These recommendations were informed by a comprehensive literature review and agreed by 42 international experts, including clinicians, public health professionals, researchers, commissioners, and community representatives. By applying the recommendations to 2019 national HIV surveillance data from the UK, we show that 30% of deaths among people with HIV were HIV-related or possibly HIV-related, and at least 63% of these deaths were preventable or potentially preventable. The application of these recommendations by health authorities will ensure consistent monitoring of HIV elimination targets and allow for the identification of inequalities and areas for intervention.


Assuntos
Infecções por HIV , Humanos , Consenso , Saúde Pública , Pessoal de Saúde
11.
J Hazard Mater ; 443(Pt B): 130256, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36327845

RESUMO

Phthalate acid esters (PAEs) are commonly used plastic additives, not chemically bound to the plastic that migrate into surrounding environments, posing a threat to environmental and human health. Dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) are two common PAEs found in agricultural soils, where degradation is attributed to microbial decomposition. Yet the impact of the plastic matrix on PAE degradation rates is poorly understood. Using 14C-labelled DBP and DEHP we show that migration from the plastic matrix into soil represents a key rate limiting step in their bioavailability and subsequent degradation. Incorporating PAEs into plastic film decreased their degradation in soil, DBP (DEHP) from 79% to 21% (9% to <1%), over four months when compared to direct application of PAEs. Mimicking surface soil conditions, we demonstrated that exposure to ultraviolet radiation accelerated PAE mineralisation twofold. Turnover of PAE was promoted by the addition of biosolids, while the presence of plants and other organic residues failed to promote degradation. We conclude that PAEs persist in soil for longer than previously thought due to physical trapping within the plastic matrix, suggesting PAEs released from plastics over very long time periods lead to increasing levels of contamination.


Assuntos
Dietilexilftalato , Ácidos Ftálicos , Poluentes do Solo , Humanos , China , Dibutilftalato/metabolismo , Ésteres/química , Ácidos Ftálicos/química , Plásticos/química , Solo/química , Poluentes do Solo/metabolismo , Raios Ultravioleta
12.
Sci Total Environ ; 861: 160660, 2023 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-36464051

RESUMO

Extreme weather events are increasing in frequency and magnitude with profound effects on ecosystem functioning. Further, there is now a greater likelihood that multiple extreme events are occurring within a single year. Here we investigated the effect of a single drought, flood or compound (flood + drought) extreme event on temperate grassland ecosystem processes in a field experiment. To assess system resistance and resilience, we studied changes in a wide range of above- and below-ground indicators (plant diversity and productivity, greenhouse gas emissions, soil chemical, physical and biological metrics) during the 8 week stress events and then for 2 years post-stress. We hypothesized that agricultural grasslands would have different degrees of resistance and resilience to flood and drought stress. We also investigated two alternative hypotheses that the combined flood + drought treatment would either, (A) promote ecosystem resilience through more rapid recovery of soil moisture conditions or (B) exacerbate the impact of the single flood or drought event. Our results showed that flooding had a much greater effect than drought on ecosystem processes and that the grassland was more resistant and resilient to drought than to flood. The immediate impact of flooding on all indicators was negative, especially for those related to production, and climate and water regulation. Flooding stress caused pronounced and persistent shifts in soil microbial and plant communities with large implications for nutrient cycling and long-term ecosystem function. The compound flood + drought treatment failed to show a more severe impact than the single extreme events. Rather, there was an indication of quicker recovery of soil and microbial parameters suggesting greater resilience in line with hypothesis (A). This study clearly reveals that contrasting extreme weather events differentially affect grassland ecosystem function but that concurrent events of a contrasting nature may promote ecosystem resilience to future stress.


Assuntos
Ecossistema , Clima Extremo , Pradaria , Plantas , Solo/química , Secas
13.
Clin Infect Dis ; 76(3): 398-407, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36210481

RESUMO

BACKGROUND: The recombinant protein-based vaccine, NVX-CoV2373, demonstrated 89.7% efficacy against coronavirus disease 2019 (COVID-19) in a phase 3, randomized, observer-blinded, placebo-controlled trial in the United Kingdom. The protocol was amended to include a blinded crossover. Data to the end of the placebo-controlled phase are reported. METHODS: Adults aged 18-84 years received 2 doses of NVX-CoV2373 or placebo (1:1) and were monitored for virologically confirmed mild, moderate, or severe COVID-19 (onset from 7 days after second vaccination). Participants who developed immunoglobulin G (IgG) against nucleocapsid protein but did not show symptomatic COVID-19 were considered asymptomatic. Secondary outcomes included anti-spike (S) IgG responses, wild-type virus neutralization, and T-cell responses. RESULTS: Of 15 185 participants, 13 989 remained in the per-protocol efficacy population (6989 NVX-CoV2373, 7000 placebo). At a maximum of 7.5 months (median, 4.5) postvaccination, there were 24 cases of COVID-19 among NVX-CoV2373 recipients and 134 cases among placebo recipients, a vaccine efficacy of 82.7% (95% confidence interval [CI], 73.3%-88.8%). Vaccine efficacy was 100% (95% CI, 17.9%-100.0%) against severe disease and 76.3% (95% CI, 57.4%-86.8%) against asymptomatic disease. High anti-S and neutralization responses to vaccination were evident, together with S-protein-specific induction of interferon-γ secretion in peripheral blood T cells. Incidence of serious adverse events and adverse events of special interest were similar between groups. CONCLUSIONS: A 2-dose regimen of NVX-CoV2373 conferred a high level of ongoing protection against asymptomatic, symptomatic, and severe COVID-19 through >6 months postvaccination. A gradual decrease of protection suggests that a booster may be indicated. CLINICAL TRIALS REGISTRATION: EudraCT, 2020-004123-16.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Adulto , Humanos , Vacinas contra COVID-19/efeitos adversos , COVID-19/prevenção & controle , SARS-CoV-2 , Vacinas Sintéticas/efeitos adversos , Imunoglobulina G , Imunogenicidade da Vacina , Método Duplo-Cego , Anticorpos Antivirais
14.
Eur J Soil Sci ; 74(2): e13363, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38529015

RESUMO

Agricultural soils are a major source of the potent greenhouse gas and ozone depleting substance, N2O. To implement management practices that minimize microbial N2O production and maximize its consumption (i.e., complete denitrification), we must understand the interplay between simultaneously occurring biological and physical processes, especially how this changes with soil depth. Meaningfully disentangling of these processes is challenging and typical N2O flux measurement techniques provide little insight into subsurface mechanisms. In addition, denitrification studies are often conducted on sieved soil in altered O2 environments which relate poorly to in situ field conditions. Here, we developed a novel incubation system with headspaces both above and below the soil cores and field-relevant O2 concentrations to better represent in situ conditions. We incubated intact sandy clay loam textured agricultural topsoil (0-10 cm) and subsoil (50-60 cm) cores for 3-4 days at 50% and 70% water-filled pore space, respectively. 15N-N2O pool dilution and an SF6 tracer were injected below the cores to determine the relative diffusivity and the net N2O emission and gross N2O emission and consumption fluxes. The relationship between calculated fluxes from the below and above soil core headspaces confirmed that the system performed well. Relative diffusivity did not vary with depth, likely due to the preservation of preferential flow pathways in the intact cores. Gross N2O emission and uptake also did not differ with depth but were higher in the drier cores, contrary to expectation. We speculate this was due to aerobic denitrification being the primary N2O consuming process and simultaneously occurring denitrification and nitrification both producing N2O in the drier cores. We provide further evidence of substantial N2O consumption in drier soil but without net negative N2O emissions. The results from this study are important for the future application of the 15N-N2O pool dilution method and N budgeting and modelling, as required for improving management to minimize N2O losses.

15.
Sensors (Basel) ; 22(23)2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36501798

RESUMO

Crop productivity is highly dependent on the availability of soluble nitrogen (N), e.g. nitrate, in soil. When N levels are low, fertilisers are applied to replenish the soil's reserves. Typically the timing of these applications is based on paper-based guidance and sensor-based measurements of canopy greenness, which provides an indirect measure of soil N status. However this approach often means that N fertiliser is applied inappropriately or too late, resulting in excess N being lost to the environment, or too little N to meet crop demand. To promote greater N use efficiency and improve agricultural sustainability, we developed an Internet of Things (IoT) approach for the real-time measurement of soil nitrate levels using ion-selective membrane sensors in combination with digital soil moisture probes. The node incorporates state-of-the-art IoT connectivity using a LoRaWAN transceiver. The sensing platform can transfer real-time data via a cloud-connected gateway for processing and storage. In summary, we present a validated soil sensor system for real-time monitoring of soil nitrate concentrations, which can support fertiliser management decisions, improve N use efficiency and reduce N losses to the environment.


Assuntos
Nitratos , Solo , Eletrodos Seletivos de Íons , Agricultura/métodos , Fertilizantes/análise
16.
Int J STD AIDS ; 33(11): 1013-1017, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36062733

RESUMO

BACKGROUND: HIV-2 is rare in the UK. Many UK centres therefore only treat small numbers of people and there are few clinical trials to guide treatment. The British HIV Association (BHIVA) 2010 guidelines for management of HIV-2 formed the basis for this national audit, which aims to describe current practice and adherence to guidelines. METHODS: All UK centres providing HIV care were contacted via the BHIVA "Members Matters" newsletter, and asked to submit anonymised, retrospective data for individuals living with HIV-2 accessing care at their service. RESULTS: Thirty-five sites responded and data were analysed for 167 individuals. Nearly half of individuals accessed care at one of four large London centres (77/167, 46%).Most people living with HIV-2 have taken antiretroviral therapy (ART) (132/167, 79%). The most common reasons for initiating treatment were clinical disease (34/89, 38%) and pregnancy (11/89, 12%). Most treatment-naïve individuals were initiated on a protease inhibitor based regimen (70/89, 79%). The use of integrase strand transfer inhibitor based regimens has increased over time.A significant minority of patients did not have baseline drug resistance testing performed, despite having a detectable viral load (15/52, 29%). Virological failure occurred in a minority of individuals (21/132, 16%); the most common drug regimen change in this context was the addition of an integrase strand transfer inhibitor (12/26 regimen changes, 46%). CONCLUSIONS: Most individuals living with HIV-2 were managed according to national guidance, with key areas for improvement including the choice of ART, drug resistance testing and the management of virological failure. It is hoped that this national audit, performed in conjunction with the updated 2021 BHIVA guidelines will improve the care of individuals living with HIV-2 in the UK.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Adulto , Fármacos Anti-HIV/uso terapêutico , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , HIV-2 , Humanos , Integrases/uso terapêutico , Gravidez , Inibidores de Proteases/uso terapêutico , Estudos Retrospectivos , Reino Unido/epidemiologia , Carga Viral
17.
Environ Res ; 214(Pt 4): 114142, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35995222

RESUMO

Increasing tropospheric ozone poses a potential threat to both above- and belowground components of the terrestrial biosphere. Microorganisms are the main drivers of soil ecological processes, however, the link between soil microbial communities and ecological functions under elevated ozone remains poorly understood. In this study, we assessed the responses of three crop seedlings (i.e., soybean, maize, and wheat) growth and soil microbial communities to elevated ozone (40 ppb O3 above ambient air) in a pot experiment in the solardomes. Results showed that elevated ozone adversely affected ecosystem multifunctionality by reducing crop biomass, inhibiting soil extracellular enzyme activities, and altering nutrient availability. Elevated ozone increased bacterial and fungal co-occurrence network complexity, negatively correlated with ecosystem multifunctionality. Changes in the relative abundance of some specific bacteria and fungi were associated with multiple ecosystem functioning. In addition, elevated ozone significantly affected fungal community composition but not bacterial community composition and microbial alpha-diversity. Crop type played a key role in determining bacterial alpha-diversity and microbial community composition. In conclusion, our findings suggest that short-term elevated ozone could lead to a decrease in ecosystem multifunctionality associated with changes in the complexity of microbial networks in soils.


Assuntos
Microbiota , Ozônio , Bactérias , Ecossistema , Fungos , Ozônio/análise , Ozônio/toxicidade , Solo , Microbiologia do Solo
18.
Sci Total Environ ; 850: 158070, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-35981583

RESUMO

Nitrous oxide (N2O) is a potent greenhouse gas (GHG) whose emission from soil can be enhanced by ruminant excretal returns in grasslands. The default (Tier 1) emission factors (EF3PRP; i.e. proportion of deposited nitrogen emitted as N2O) for ruminant excreta deposition are associated with a wide range of uncertainties and the development of country-specific (Tier 2) EF3PRP is encouraged. In Ireland, a Tier 2 EF3PRP has been developed for cattle excreta but no data are available for sheep. The aim of this study was to generate data to contribute to the derivation of a Tier 2 EF3PRP for sheep excreta, while assessing the effect of excreta type, grassland type and season of deposition on N2O emissions. An experiment was carried out on two sites in the west of Ireland: a managed lowland grassland (LOW) and an extensively grazed hill pasture (HILL), characterised by mineral and acid peat soils, respectively. For each season, four treatments were applied to the soil in a fully randomized block design: control (C), sheep urine (U), sheep dung (D), and artificial urine (AU). Nitrous oxide fluxes were assessed over a full year following each application of treatments, using a static chambers methodology. Results showed a brief initial peak following each application of U/AU in LOW but not in HILL. Cumulative N2O emissions were significantly higher from the lowland site. Average EF3PRP for combined excreta was negligible on both sites, thus lower than the IPCC Tier 1 EF3PRP. Causes of low emissions are likely to depend on site characteristics (e.g. soil acidity in HILL) and season of application (i.e. ammonia volatilisation in summer). This study showed very low N2O emissions from sheep excretal returns in Irish grasslands and highlighted the importance of developing Tier 2, animal-specific EF3PRP. More experimental grasslands should be assessed to confirm these results.


Assuntos
Gases de Efeito Estufa , Óxido Nitroso , Amônia/análise , Animais , Bovinos , Pradaria , Nitrogênio , Óxido Nitroso/análise , Ovinos , Solo
19.
Front Microbiol ; 13: 901658, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35847072

RESUMO

Currently, modified biochar has been successfully used in the remediation of soil polluted with heavy metals. However, the effects of the modified biochar on pesticides (such as simazine) are still unclear. Herein, the environmental fate of simazine, such as decomposition, leaching, and adsorption in unamended soil, in the soil amended with unmodified and modified biochar (biochar + FeCl3, biochar + FeOS, biochar + Fe) were evaluated. In addition, an incubation experiment was also performed to observe the influence of modified biochar on the microbial community and diversity in the soil. The results showed that modified biochar significantly decreased the decomposition of simazine in the soil compared to its counterpart. Modified biochar also reduced the concentration of simazine in the leachate. Compared with the control, soil microbial biomass in the soil amended with unmodified biochar, biochar + FeCl3, biochar + Fe, and biochar + FeOS was decreased by 5.3%, 18.8%, 8.7%, and 18.1%, respectively. Furthermore, modified biochar changed the structure of the microbial community. This shows that modified biochar could increase the soil adsorption capacity for simazine and change the amount and microbial community that regulates the fate of simazine in the soil. This study concludes that iron-modified biochar has positive and negative effects on the soil. Therefore, its advantages and side effects should be considered before applying it to the soil.

20.
J Hazard Mater ; 435: 129065, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35650746

RESUMO

Plastic pollution is one of the global pressing environmental problems, threatening the health of aquatic and terrestrial ecosystems. However, the influence of plastic residues and microplastics (MPs) in soil ecosystems remains unclear. We conducted a global meta-analysis to quantify the effect of plastic residues and MPs on indicators of global soil ecosystem functioning (i.e. soil physicochemical properties, plant and soil animal health, abundance and diversity of soil microorganisms). Concentrations of plastic residues and MPs were 1-2700 kg ha-1 and 0.01-600,000 mg kg-1, respectively, based on 6223 observations. Results show that plastic residues and MPs can decrease soil wetting front vertical and horizontal movement, dissolved organic carbon, and total nitrogen content of soil by 14%, 10%, 9%, and 7%, respectively. Plant height and root biomass were decreased by 13% and 14% in the presence of plastic residues and MPs, while the body mass and reproduction rate of soil animals decreased by 5% and 11%, respectively. However, soil enzyme activity increased by 7%441% in the presence of plastic residues and MPs. For soil microorganisms, plastic residues and MPs can change the abundance of several bacteria phyla and families, but the effects vary between different bacteria.


Assuntos
Microplásticos , Solo , Animais , Ecossistema , Microplásticos/toxicidade , Plásticos , Solo/química , Microbiologia do Solo
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