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1.
Environ Sci Technol ; 57(27): 10019-10029, 2023 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-37382932

RESUMEN

Over the past several decades, agricultural sulfur (S) use has dramatically increased. Excess S in the environment can cause several biogeochemical and ecologic consequences, including methylmercury production. This study investigated agriculturally associated changes to organic S─the most dominant form of S within soils─from field-to-watershed scales. Using a novel complementary suite of analytical methods, we combined Fourier transform ion cyclotron resonance mass spectrometry, δ34S-DOS, and S X-ray absorption spectroscopy to characterize dissolved organic S (DOS) in soil porewater and surface water samples from vineyard agriculture (S addition) and forest/grassland areas (no S addition) within the Napa River watershed (California, U.S.). Vineyard soil porewater dissolved organic matter samples had two-fold higher S content compared to forest/grasslands and had unique CHOS2 chemical formulas─the latter also found in tributary and Napa River surface water. The isotopic difference between δ34S-DOS and δ34S-SO42- values provided insights into the likely dominant microbial S processes by land use/land cover (LULC), whereas the S oxidation state did not strongly differ by LULC. The results add to our understanding of the modern S cycle and point to upland agricultural areas as S sources with the potential for rapid S transformations in downgradient environments.


Asunto(s)
Agricultura , Materia Orgánica Disuelta , Suelo , Azufre/análisis , Agua
2.
Nat Commun ; 13(1): 2043, 2022 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-35440561

RESUMEN

Rising emissions from wildfires over recent decades in the Pacific Northwest are known to counteract the reductions in human-produced aerosol pollution over North America. Since amplified Pacific Northwest wildfires are predicted under accelerating climate change, it is essential to understand both local and transported contributions to air pollution in North America. Here, we find corresponding increases for carbon monoxide emitted from the Pacific Northwest wildfires and observe significant impacts on both local and down-wind air pollution. Between 2002 and 2018, the Pacific Northwest atmospheric carbon monoxide abundance increased in August, while other months showed decreasing carbon monoxide, so modifying the seasonal pattern. These seasonal pattern changes extend over large regions of North America, to the Central USA and Northeast North America regions, indicating that transported wildfire pollution could potentially impact the health of millions of people.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Incendios Forestales , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Monóxido de Carbono , Humanos , América del Norte , Estaciones del Año
3.
Environ Sci Technol ; 55(14): 9637-9656, 2021 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-34232025

RESUMEN

The biogeochemical cycling of soil organic matter (SOM) plays a central role in regulating soil health, water quality, carbon storage, and greenhouse gas emissions. Thus, many studies have been conducted to reveal how anthropogenic and climate variables affect carbon sequestration and nutrient cycling. Among the analytical techniques used to better understand the speciation and transformation of SOM, Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) is the only technique that has sufficient mass resolving power to separate and accurately assign elemental compositions to individual SOM molecules. The global increase in the application of FTICR MS to address SOM complexity has highlighted the many challenges and opportunities associated with SOM sample preparation, FTICR MS analysis, and mass spectral interpretation. Here, we provide a critical review of recent strategies for SOM characterization by FTICR MS with emphasis on SOM sample collection, preparation, analysis, and data interpretation. Data processing and visualization methods are presented with suggested workflows that detail the considerations needed for the application of molecular information derived from FTICR MS. Finally, we highlight current research gaps, biases, and future directions needed to improve our understanding of organic matter chemistry and cycling within terrestrial ecosystems.


Asunto(s)
Ecosistema , Suelo , Ciclotrones , Análisis de Fourier , Espectrometría de Masas
4.
PLoS One ; 15(4): e0230235, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32240199

RESUMEN

BACKGROUND: Rotator cuff tears are a common cause of shoulder pain and can result in prolonged periods of pain, disability and absence from work. Rotator cuff repair surgery is increasingly used in an attempt to resolve symptoms but has failure rates of around 40%. There is a pressing need to improve the outcome of rotator cuff repairs. Patch augmentation increasingly being used within the NHS in an attempt to reduce repair failures. The aim of this survey was to determine current UK practice and opinion relating to the factors that influence choice of patch, current patient selection and willingness to assist with generation of improved evidence. METHODS: An online survey was sent to the surgeon members of the British Elbow and Shoulder Society (BESS). Questions covered respondent demographics, experience with patches, indications for patch augmentation and willingness to be involved in a randomised trial of patch augmented rotator cuff surgery. RESULTS: The response rate was 105/550 (19%). 58% of respondents had used a patch to augment rotator cuff surgery. 70% of patch users had undertaken an augmented repair within the last 6 months. A wide surgical experience in augmentation was reported (ranging 1 to 200 implants used). However, most surgeons reported low volume usage, with a median of 5 rotator cuff augmentation procedures performed. At least 10 different products had been used. Most of the patches used were constructed from human decellularised dermis tissue, although porcine derived and synthetic based patches had also been used. Only 3-5% stated they would undertake an augmented repair for small tears across ages, whereas 28-40% and 19-59% would do so for large or massive tears respectively. When assessing patient suitability, patient age seemed relevant only for those with large and massive tears. Half of the surgeons reported an interest in taking part in a randomised controlled trial (RCT) evaluating the role of patch augmentation for rotator cuff surgery, with a further 22% of respondent's undecided. CONCLUSIONS: A variety of patches have been used by surgeons to augment rotator cuff repair with a wide range of operator experience. There was substantial uncertainty about which patch to use and differing views on which patients were most suitable. There is a clear need for robust clinical evaluation and further research in this area.


Asunto(s)
Artroplastia/métodos , Artroscopía/métodos , Toma de Decisiones Clínicas/métodos , Lesiones del Manguito de los Rotadores/cirugía , Manguito de los Rotadores/cirugía , Anciano , Anciano de 80 o más Años , Animales , Codo/inervación , Codo/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prótesis e Implantes , Manguito de los Rotadores/inervación , Manguito de los Rotadores/patología , Lesiones del Manguito de los Rotadores/patología , Hombro/inervación , Hombro/patología , Hombro/cirugía , Dolor de Hombro/prevención & control , Dolor de Hombro/cirugía , Encuestas y Cuestionarios , Porcinos , Resultado del Tratamiento , Incertidumbre , Reino Unido , Lesiones de Codo
5.
Bone Joint J ; 101-B(1): 55-62, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30601058

RESUMEN

AIMS: The aims of this study were to compare the use of resources, costs, and quality of life outcomes associated with subacromial decompression, arthroscopy only (placebo surgery), and no treatment for subacromial pain in the United Kingdom National Health Service (NHS), and to estimate their cost-effectiveness. PATIENTS AND METHODS: The use of resources, costs, and quality-adjusted life-years (QALYs) were assessed in the trial at six months and one year. Results were extrapolated to two years after randomization. Differences between treatment arms, based on the intention-to-treat principle, were adjusted for covariates and missing data were handled using multiple imputation. Incremental cost-effectiveness ratios were calculated, with uncertainty around the values estimated using bootstrapping. RESULTS: Cumulative mean QALYs/mean costs of health care service use and surgery per patient from baseline to 12 months were estimated as 0.640 (standard error (se) 0.024)/£3147 (se 166) in the decompression arm, 0.656 (se 0.020)/£2830 (se 183) in the arthroscopy only arm and 0.522 (se 0.029)/£1451 (se 151) in the no treatment arm. Statistically significant differences in cumulative QALYs and costs were found at six and 12 months for the decompression versus no treatment comparison only. The probabilities of decompression being cost-effective compared with no treatment at a willingness-to-pay threshold of £20 000 per QALY were close to 0% at six months and approximately 50% at one year, with this probability potentially increasing for the extrapolation to two years. DISCUSSION: The evidence for cost-effectiveness at 12 months was inconclusive. Decompression could be cost-effective in the longer-term, but results of this analysis are sensitive to the assumptions made about how costs and QALYs are extrapolated beyond the follow-up of the trial.


Asunto(s)
Artroscopía/economía , Descompresión Quirúrgica/economía , Dolor de Hombro/economía , Adulto , Anciano , Artroscopía/métodos , Análisis Costo-Beneficio , Descompresión Quirúrgica/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud/estadística & datos numéricos , Años de Vida Ajustados por Calidad de Vida , Dolor de Hombro/cirugía , Resultado del Tratamiento
6.
Artículo en Inglés | MEDLINE | ID: mdl-30297463

RESUMEN

The outstanding tropical land climate characteristic over the past decades is rapid warming, with no significant large-scale precipitation trends. This warming is expected to continue but the effects on tropical vegetation are unknown. El Niño-related heat peaks may provide a test bed for a future hotter world. Here we analyse tropical land carbon cycle responses to the 2015/16 El Niño heat and drought anomalies using an atmospheric transport inversion. Based on the global atmospheric CO2 and fossil fuel emission records, we find no obvious signs of anomalously large carbon release compared with earlier El Niño events, suggesting resilience of tropical vegetation. We find roughly equal net carbon release anomalies from Amazonia and tropical Africa, approximately 0.5 PgC each, and smaller carbon release anomalies from tropical East Asia and southern Africa. Atmospheric CO anomalies reveal substantial fire carbon release from tropical East Asia peaking in October 2015 while fires contribute only a minor amount to the Amazonian carbon flux anomaly. Anomalously large Amazonian carbon flux release is consistent with downregulation of primary productivity during peak negative near-surface water anomaly (October 2015 to March 2016) as diagnosed by solar-induced fluorescence. Finally, we find an unexpected anomalous positive flux to the atmosphere from tropical Africa early in 2016, coincident with substantial CO release.This article is part of a discussion meeting issue 'The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.


Asunto(s)
Atmósfera/análisis , Ciclo del Carbono , El Niño Oscilación del Sur , Gases de Efecto Invernadero/análisis , Tecnología de Sensores Remotos , Clima Tropical , Sequías , Calor
7.
Artículo en Inglés | MEDLINE | ID: mdl-30297466

RESUMEN

Southeast Asia, in particular Indonesia, has periodically struggled with intense fire events. These events convert substantial amounts of carbon stored as peat to atmospheric carbon dioxide (CO2) and significantly affect atmospheric composition on a regional to global scale. During the recent 2015 El Niño event, peat fires led to strong enhancements of carbon monoxide (CO), an air pollutant and well-known tracer for biomass burning. These enhancements were clearly observed from space by the Infrared Atmospheric Sounding Interferometer (IASI) and the Measurements of Pollution in the Troposphere (MOPITT) instruments. We use these satellite observations to estimate CO fire emissions within an inverse modelling framework. We find that the derived CO emissions for each sub-region of Indonesia and Papua are substantially different from emission inventories, highlighting uncertainties in bottom-up estimates. CO fire emissions based on either MOPITT or IASI have a similar spatial pattern and evolution in time, and a 10% uncertainty based on a set of sensitivity tests we performed. Thus, CO satellite data have a high potential to complement existing operational fire emission estimates based on satellite observations of fire counts, fire radiative power and burned area, in better constraining fire occurrence and the associated conversion of peat carbon to atmospheric CO2 A total carbon release to the atmosphere of 0.35-0.60 Pg C can be estimated based on our results.This article is part of a discussion meeting issue 'The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monóxido de Carbono/análisis , Incendios , El Niño Oscilación del Sur , Indonesia , Tecnología de Sensores Remotos
8.
Nat Commun ; 9(1): 536, 2018 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-29440640

RESUMEN

Tropical carbon emissions are largely derived from direct forest clearing processes. Yet, emissions from drought-induced forest fires are, usually, not included in national-level carbon emission inventories. Here we examine Brazilian Amazon drought impacts on fire incidence and associated forest fire carbon emissions over the period 2003-2015. We show that despite a 76% decline in deforestation rates over the past 13 years, fire incidence increased by 36% during the 2015 drought compared to the preceding 12 years. The 2015 drought had the largest ever ratio of active fire counts to deforestation, with active fires occurring over an area of 799,293 km2. Gross emissions from forest fires (989 ± 504 Tg CO2 year-1) alone are more than half as great as those from old-growth forest deforestation during drought years. We conclude that carbon emission inventories intended for accounting and developing policies need to take account of substantial forest fire emissions not associated to the deforestation process.

10.
Appl Opt ; 43(24): 4685-96, 2004 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-15352393

RESUMEN

The Measurements of Pollution in the Troposphere (MOPITT) Airborne Test Radiometer (MATR) uses gas correlation filter radiometry from high-altitude aircraft to measure tropospheric carbon monoxide. This radiometer is used in support of the ongoing validation campaign for the MOPITT instrument aboard the Earth Observation System Terra satellite. A recent study of MATR CO retrievals that used data from the autumn of 2001 in the western United States is presented. Retrievals of the CO total column were performed and compared to in situ sampling with less than 10% retrieval error. Effects that influence retrieval, such as instrument sensitivity, retrieval sensitivity, and the bias between observations and the radiative transfer model, are discussed. Comparisons of MATR and MOPITT retrievals show promising consistency. A preliminary interpretation of MATR results is also presented.

11.
J Surg Oncol ; 78(3): 171-4, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11745800

RESUMEN

BACKGROUND AND OBJECTIVES: Malignant mesothelioma is a lethal disease. Aggressive multimodality treatment protocols are reportedly associated with improved survival, but the apparent survival benefits may simply reflect patient selection and the variable natural history of this malignancy. Before embarking on our own protocol of experimental treatment for mesothelioma, we sought to identify important prognostic factors and document the survival of patients treated conservatively (with palliative intent only) in our region. METHODS: We performed a retrospective review of all patients with a diagnosis of malignant mesothelioma seen at our center between 1987 and 1999. Since curative intent treatment had not been given, we assumed that measured survival would largely reflect the natural history of the malignancy. RESULTS: There were 101 patients (80 males and 21 females). Mean age was 65 +/- 9.2 years. Symptoms of disease were present for a median time of 5 months before the diagnosis was established. The most common presenting symptoms were dyspnea (46 patients), chest pain (30 patients), and weight loss (22 patients). Sixty-eight patients (68%) had a history of asbestos exposure. Mesothelioma subtypes included epithelial (43 patients), sarcomatous (26 patients), mixed (19 patients), desmoplastic (4 patients), and unspecified (9 patients). All 101 patients were treated with palliative intent. Talc pleurodesis was performed in 70 patients. At the time of analysis, 90 patients had died and 11 remained alive. Median survival was 213 (95% CI 137-289) days. Survival for the three major histological subtypes was significantly different (log rank, P = 0.0016). Histological subtype (epithelial favorable) was the only significant independent prognostic factor (Cox proportional hazard regression, P = 0.0009). CONCLUSIONS: Patients with epithelial mesothelioma survive longer than those with other histological subtypes. Conservatively managed patients with pleural malignant mesothelioma have a median survival of approximately 7 months. These data from conservatively treated patients can serve as baseline information for future studies of experimental treatments.


Asunto(s)
Mesotelioma/mortalidad , Cuidados Paliativos , Neoplasias Pleurales/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Mesotelioma/terapia , Persona de Mediana Edad , Neoplasias Pleurales/terapia , Estudios Retrospectivos , Análisis de Supervivencia
12.
Behav Res Methods Instrum Comput ; 33(2): 115-23, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11447663

RESUMEN

Previous studies of the perceptual processing and dynamics of emotional expression in faces have been limited by the lack of realistic yet controlled stimuli. The present work offers researchers a method for creating such stimuli for exploring these phenomena. We describe the creation of the stimuli and a series of experiments testing the validity of these stimuli with respect to emotional expressions in humans. Participants evaluated synthesized facial images and standardized photographs of six basic emotional expressions for intensity and accuracy of perceived emotion. Comparisons of these measures were qualitatively similar for synthesized and photographed faces. A manipulation of the magnitude of the synthesized expressions yielded a significant effect on the perceived intensity of expression. In a subsequent multidimensional scaling study, no systematic differences were uncovered in the derived configurations of the synthesized expressions and the photographs. These results are discussed in the context of possible future research applications.


Asunto(s)
Cara , Expresión Facial , Emociones , Femenino , Humanos , Masculino , Percepción Visual
13.
Acad Manage J ; 35(3): 653-70, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10120414

RESUMEN

Researchers have recommended that the theoretical constructs underlying just-in-time (JIT) management systems be identified and developed if JIT is to be fully understood and its full capabilities realized. In this study, we advanced this conceptual development through an instrument based on the relevant literature and empirically deriving three underlying constructs: (1) operating structure and control, (2) product scheduling, and (3) quality implementation. We report a content analysis of these constructs and develop propositions regarding their relationships, predecessors, and outcomes.


Asunto(s)
Industrias/organización & administración , Administración de Línea de Producción/métodos , Recolección de Datos , Análisis Factorial , Industrias/estadística & datos numéricos , Inventarios de Hospitales/organización & administración , Participación en las Decisiones , Solución de Problemas , Factores de Tiempo , Estados Unidos
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