Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.873
Filtrar
1.
J Environ Qual ; 49(2): 324-334, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33016426

RESUMO

Managing a sustainable dairy farm requires balancing phosphorus (P) imports and exports that enter and leave through the farm gate. Over the long term, P surpluses will elevate soil-test P concentrations above crop requirements through routine land applications of manure. The objectives of this study were aimed at Virginia dairy farms (a) to determine P mass balances, (b) to define potential guidelines for a sustainable and feasible zone of operation based on P balance and P use efficiency, and (c) to assess risk factors driving P surplus and P use inefficiencies. Data on farm-gate P imports and exports via feed, manure, crops, fertilizers, bedding, animals, and milk were collected for 58 dairy farms in Virginia. There was no relationship between farm P balance and milk production, indicating that a P surplus was not necessary for good milk productivity. A feasible P balance limit was calculated below which 75% of farms could operate, and this was 18.7 kg P ha-1 . Two risk factors were identified for farms having a P balance above this limit: (a) land application of poultry litter and (b) excessive import of P through feed. Combined dairy and beef operations generally had more land and a lower P balance, whereas having combined dairy and poultry did not raise the P balance as long as poultry litter was exported. Dairy farms in Virginia can operate with a sustainable P balance as long as they avoid using excessive poultry litter and pay attention to P imported through purchased feed.


Assuntos
Indústria de Laticínios , Fósforo/análise , Ração Animal/análise , Animais , Bovinos , Fazendas , Nitrogênio/análise , Virginia
2.
Public Health Rep ; 135(5): 668-675, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32791024

RESUMO

OBJECTIVES: The Virginia Department of Health (VDH) identified an outbreak of Salmonella serotype Javiana infections in Virginia after a chili and chowder cook-off with 11 competitors and about 2500 attendees on September 30, 2017. The objectives of this study were to assess the extent of the outbreak and identify the most likely source of exposure. METHODS: To identify people with suspected Salmonella infection, VDH used press releases and social media posts to recruit event attendees to take an online survey about foods eaten at the cook-off and any gastrointestinal (GI) symptoms experienced. VDH defined a case as reported GI illness that occurred within 1 week after eating food from the cook-off. Confirmed cases required a clinical specimen culture positive for Salmonella. Probable cases reported diarrhea or related clinical symptoms. "Not ill" people did not report GI illness. Investigators calculated unadjusted relative risks of illness and performed stratified analysis to address potential confounding. Available food samples were tested for Salmonella. Environmental health specialists interviewed food handlers and inspected restaurants where 3 competitors had prepared food. RESULTS: Of 438 survey responses, 171 (39%) met the case definition. Of all chilies and chowders consumed, Chowder A was associated with the highest relative risk of illness (8.9; 95% CI, 5.7-13.7). A Chowder A sample tested positive for Salmonella serotype Javiana. The environmental investigation did not identify an original contamination source but did find deficiencies in maintaining safe cooking temperatures. CONCLUSIONS: Epidemiologic and laboratory findings indicated that Chowder A was the most likely cause of outbreak. Recommendations to prevent future outbreaks include preparation of all food on-site to ensure safe temperatures during food preparation and service.


Assuntos
Capsicum/microbiologia , Surtos de Doenças/estatística & dados numéricos , Contaminação de Alimentos/estatística & dados numéricos , Restaurantes/estatística & dados numéricos , Intoxicação Alimentar por Salmonella/epidemiologia , Humanos , Virginia/epidemiologia
3.
PLoS One ; 15(8): e0225355, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750055

RESUMO

Across taxa, sex-specific demands vary temporally in accordance with reproductive investments. In solitary carnivores, females must provision and protect young independently while meeting increased energetic demands. Males seek to monopolize access to females by maintaining large territories and defending them from other males. For many species, it is poorly understood how these demands relate to broad-scale animal movements. To investigate predictions surrounding the reproductive strategies of solitary carnivores and effects of local conditions on bobcat (Lynx rufus) spatial ecology, we examined the effects of sex and reproductive season on home range size, movement rate, and resource selection of bobcats in the central Appalachian Mountains. Male seasonal home ranges were approximately 3 times larger than those of females (33.9 ± 2.6 vs. 12.1 ± 2.4 km2, x±SE), and male movement rates were 1.4 times greater than females (212.6 ± 3.6 vs. 155 ± 8.2 m/hr), likely reflecting male efforts to maximize access to females. Both sexes appear to maintain relatively stable seasonal home ranges despite temporally varying reproductive investments, instead adjusting movements within home ranges. Males increased movements during the dispersal period, potentially reflecting increased territoriality prior to breeding. Females increased movements during the kitten-rearing period, when foraging more intensively, and frequently returning to den sites. Both sexes selected home ranges at higher elevations. However, females selected deciduous forest and avoided fields, whereas males selected fields and avoided deciduous forest, perhaps explained by male pressure to access multiple females across several mountain ridges and higher risk tolerance. Seasonal changes in home range selection likely reflect changes in home range shape. Increased female avoidance of fields during kitten rearing may indicate female avoidance of presumably resource rich, yet risky, fields at the time when kittens are most vulnerable. Our results indicate that while reproductive chronology influences the spatial ecology of solitary carnivores, effects may be constrained by territoriality.


Assuntos
Demografia/tendências , Lynx/fisiologia , Reprodução/fisiologia , Animais , Região dos Apalaches , Gatos , Ecossistema , Feminino , Florestas , Comportamento de Retorno ao Território Vital , Masculino , Movimento , Estações do Ano , Caracteres Sexuais , Territorialidade , Virginia
4.
Environ Pollut ; 266(Pt 2): 114820, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32640324

RESUMO

Tobacco is the most widespread non-food crop in the world. In Brazil, tobacco cultivation is one of the main commodities of the southern region. However, its production is associated with environmental impacts and risks to human health, which have yet to be quantified. This paper uses midpoint and endpoint life cycle assessment (LCA) to analyze the potential environmental damage and human health risk associated with agricultural production of conventional Virginia (CV), organic Virginia (OV), and Burley (BU) tobacco varieties. Organic tobacco production substitutes synthetic fertilizers and pesticides with organic compounds in the cropping stage. The results show that for one ton of dried tobacco, BU, CV, and OV emit 1,610, 1,426, and 1,091 kg CO2 eq, respectively. For organic production, greater impacts are linked to the land use (LU) impact category. The endpoint results showed that OV production resulted in a higher potential for human and environmental damage than BU and CV. The drying of green OV and CV tobacco requires the burning of firewood, which emits high levels of particulate matter and is associated with human health (HH) damage. Overall, the HH damage category accounts for 68%, 82%, and 78% of the total score points associated with the production of BU, CV, and OV.


Assuntos
Fertilizantes , Tabaco , Agricultura , Brasil , Humanos , Virginia
5.
Bone Joint J ; 102-B(7_Supple_B): 105-111, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32600211

RESUMO

AIMS: The purpose of this study is to examine six types of bearing surfaces implanted at a single institution over three decades to determine whether the reasons for revision vary among the groups and how long it takes to identify differences in survival. METHODS: We considered six cohorts that included a total of 1,707 primary hips done between 1982 and 2010. These included 223 conventional polyethylene sterilized with γ irradiation in air (CPE-GA), 114 conventional polyethylene sterilized with gas plasma (CPE-GP), 116 crosslinked polyethylene (XLPE), 1,083 metal-on-metal (MOM), 90 ceramic-on-ceramic (COC), and 81 surface arthroplasties (SAs). With the exception of the COC, all other groups used cobalt-chromium (CoCr) femoral heads. The mean follow-up was 10 (0.008 to 35) years. Descriptive statistics with revisions per 100 component years (re/100 yr) and survival analysis with revision for any reason as the endpoint were used to compare bearing surfaces. RESULTS: XLPE liners demonstrated a lower cumulative incidence of revision at 15 years compared to the CPE-GA and CPE-GP groups owing to the absence of wear-related revisions (4% for XLPE vs 18%, p = 0.02, and 15%, p = 0.003, respectively). Revisions for adverse local tissue reactions occurred exclusively among the MOM (0.8 re/100 year) and SA groups (0.1 re/100 year). The revision rate for instability was lower among hips with 36 mm and larger head sizes compared to smaller head sizes (0.2% vs 2%, p < 0.001). CONCLUSION: The introduction of XLPE has eliminated wear-related revisions through 15-year follow-up compared to CPE-GP and CPE-GA. Dislocation incidence has been reduced with the introduction of larger diameter heads but remains a persistent concern. The potential for adverse local tissue reactions with MOM requires continued follow-up. Cite this article: Bone Joint J 2020;102-B(7 Supple B):105-111.


Assuntos
Artroplastia de Quadril/instrumentação , Prótese de Quadril , Desenho de Prótese , Falha de Prótese/tendências , Adulto , Idoso , Cerâmica , Ligas de Cromo , Estudos de Coortes , Seguimentos , Humanos , Instabilidade Articular/cirurgia , Masculino , Próteses Articulares Metal-Metal , Pessoa de Meia-Idade , Polietileno , Reoperação/estatística & dados numéricos , Virginia
7.
Water Res ; 182: 115971, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32554269

RESUMO

The presence of earthy-musty odors in drinking water is a major concern for water suppliers and consumers worldwide. While geosmin and 2-methylisoborneol are the most studied earthy-musty odor-causing compounds, pyrazine and its alkyl and methoxy compounds possess similar odors and are widely distributed in nature, foods, and beverages. In this study, odor characteristics of pyrazines and their presence in natural and treated waters were determined. Pyrazine, 2,6-dimethyl-pyrazine (DMP), 2,3,5-trimethyl-pyrazine (TrMP), 2-ethyl-5(6)-methyl-pyrazine (EMP), 2,3,5,6-tetramethyl-pyrazine (TeMP), 2-isobutyl-3-methoxy-pyrazine (IBMP) and 2-isopropyl-3-methoxy-pyrazine (IPMP) were measured in source and finished drinking water across China. 2-Methoxy-3,5-dimethyl-pyrazine (MDMP), IBMP, and IPMP were investigated in rivers in Virginia, USA. The results showed that "musty" and "sweet" were the most common descriptors for pyrazine, DMP, MDMP, TrMP, and TeMP. While IBMP and IPMP were never detected in 140 source or drinking water samples from across China, pyrazine, DMP, MDMP, TrMP, and TeMP occurred throughout with concentrations of n.d.-62.2 ng/L-aq in source water and n.d.-39.6 ng/L-aq in finished water. IBMP, IPMP, and MDMP were present in two Virginia rivers; MDMP occurred in 18% of the samples with concentrations of n.d.-4.4 ng/L, many of which were above the aqueous odor threshold of 0.043 ng/L MDMP. The removal efficiencies through conventional water treatment were poor, ranging from negative removals to ∼10%. Advanced oxidation water treatment could only remove EMP and TrMP. The widespread presence of earthy-musty-sweet pyrazines in source and drinking waters on two continents, their poor removal during water treatment, and ng/L odor threshold concentrations confirm their potential to be T&O issues for consumers.


Assuntos
Água Potável , Poluentes Químicos da Água/análise , China , Comportamento do Consumidor , Odorantes/análise , Pirazinas/análise , Virginia
8.
J Dent Hyg ; 94(3): 37-47, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32554414

RESUMO

Purpose: The "#MeToo" movement has increased awareness of sexual harassment in the workplace and its detrimental effects on the work environment. The purpose of this study was to determine the prevalence of sexual harassment in a convenience sample of dental hygienists in the state of Virginia (VA).Methods: A cross-sectional research design was used to determine the experiences of VA dental hygienists with sexual harassment in the workplace occurring over the previous twenty-four months. The revised Sexual Experiences Questionnaire (SEQ-W) measured three constructs: gender harassment, unwanted sexual attention, and sexual coercion and was administered electronically to a convenience sample of 238 dental hygienists attending a continuing education conference. Chi-square was used to determine significant associations between survey scores and demographics.Results: A total of 161 dental hygienists completed the survey (n=161) for a response rate of 68%. A little more than one-quarter of the respondents (27%) reported at least one experience of sexual harassment in the previous 24 months. Of the three constructs measured, 27.3% of participants reported gender harassment, 18.6% unwanted sexual attention, and 6.8% sexual coercion. The most commonly reported items were being told offensive sexual jokes or stories (21%) and hearing someone make crude and offensive sexual remarks (18%). A definition of sexual harassment was provided and participants were asked, "During your career as a dental hygienist, have you experienced sexual harassment?" to which 24.2% (n=39) responded yes.Conclusion: Sexual harassment is a contemporary problem in dental hygiene employment settings in the state of Virginia. Effective training and policies in sexual harassment is needed to prevent these behaviors from occurring in the workplace.


Assuntos
Assédio Sexual , Estudos Transversais , Higienistas Dentários , Humanos , Inquéritos e Questionários , Virginia , Local de Trabalho
9.
MMWR Morb Mortal Wkly Rep ; 69(24): 740-743, 2020 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-32555139

RESUMO

In August 2019, the Virginia Poison Center (VPC) and the Blue Ridge Poison Center (BRPC) were contacted concerning patients experiencing repeated episodes of marked hypoglycemia following ingestion of a male enhancement supplement tablet marketed as "V8" in convenience stores in central Virginia. Over the following 3 months, the Virginia Department of Agriculture and Consumer Services (VDACS) and the Virginia Department of Health (VDH) conducted an investigation and identified 17 patients meeting the case definition (severe hypoglycemia within 48 hours of consuming an over-the-counter male enhancement supplement in a man with no history of use of insulin or other medication used to control blood glucose). Analysis of the V8 tablets revealed that most contained glyburide, a sulfonylurea oral hypoglycemic used in the treatment of diabetes and associated with prolonged hypoglycemia following overdose (1). To stem this outbreak, V8 was removed from stores when found, and public service announcements were released. The public health implications of V8 use include the potential for substantial morbidity from hypoglycemic episodes and the potential for mortality if health care services are not accessed in a timely manner when hypoglycemia occurs. The presence of V8 in the market poses a serious threat to public health because of its potentially life-threatening adverse effects.


Assuntos
Suplementos Nutricionais/toxicidade , Surtos de Doenças , Hipoglicemia/induzido quimicamente , Hipoglicemia/epidemiologia , Índice de Gravidade de Doença , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Virginia/epidemiologia
10.
Sci Total Environ ; 729: 138736, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32361433

RESUMO

Winter deicing salt application has led to water quality impairment as stormwater carries salt ions (Na+ and Cl-) through watersheds. Green infrastructure (GI) is a promising urban stormwater management practice, but its efficacy in managing salt is unknown. GI is not yet designed to remove salt, but may have potential to mitigate its loading to surface waters. Two roadside infiltration-based GI practices in Northern Virginia (bioretention and bioswale) were monitored year-round over 28 precipitation events to investigate the transport of salt through modern stormwater infrastructure. Stormwater runoff volumes and concentrations of salt ions entering and exiting each GI were monitored to determine reductions of salt ions. Both the bioretention and bioswale significantly reduced effluent surface loads of Cl- and Na+ (76% to 82%), displaying ability to temporarily retain and infiltrate salts and delay their release to surface waters. Changes in bioretention soil chemistry revealed a small percentage of Na+ was stored long-term by ion exchange, but no long-term Cl- storage was observed. Limited soil storage along with groundwater observations suggest the majority of salt removed from stormwater by the bioretention infiltrates into groundwater. Infiltration GI can buffer surface waters from salt, but are also an avenue for groundwater salt loading.


Assuntos
Água Subterrânea , Chuva , Cloreto de Sódio , Solo , Virginia , Movimentos da Água , Qualidade da Água
11.
PLoS One ; 15(5): e0232398, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413031

RESUMO

The microbial community composition of disease vectors can impact pathogen establishment and transmission as well as on vector behavior and fitness. While data on vector microbiota are accumulating quickly, determinants of the variation in disease vector microbial communities are incompletely understood. We explored the microbiome of two human-biting tick species abundant in eastern North America (Amblyomma americanum and Ixodes scapularis) to identify the relative contribution of tick species, tick life stage, tick sex, environmental context and vertical transmission to the richness, diversity, and species composition of the tick microbiome. We sampled 89 adult and nymphal Ixodes scapularis (N = 49) and Amblyomma americanum (N = 40) from two field sites and characterized the microbiome of each individual using the v3-v4 hypervariable region of the 16S rRNA gene. We identified significant variation in microbial community composition due to tick species and life stage with lesser impact of sampling site. Compared to unfed nymphs and males, the microbiome of engorged adult female I. scapularis, as well as the egg masses they produced, were low in bacterial richness and diversity and were dominated by Rickettsia, suggesting strong vertical transmission of this genus. Likewise, microbiota of A. americanum nymphs and males were more diverse than those of adult females. Among bacteria of public health importance, we detected several different Rickettsia sequence types, several of which were distinct from known species. Borrelia was relatively common in I. scapularis but did not show the same level of sequence variation as Rickettsia. Several bacterial genera were significantly over-represented in Borrelia-infected I. scapularis, suggesting a potential interaction of facilitative relationship between these taxa; no OTUs were under-represented in Borrelia-infected ticks. The systematic sampling we conducted for this study allowed us to partition the variation in tick microbial composition as a function of tick- and environmentally-related factors. Upon more complete understanding of the forces that shape the tick microbiome it will be possible to design targeted experimental studies to test the impacts of individual taxa and suites of microbes on vector-borne pathogen transmission and on vector biology.


Assuntos
Vetores Artrópodes/microbiologia , Ixodes/microbiologia , Ixodidae/microbiologia , Microbiota/genética , Animais , Vetores Artrópodes/crescimento & desenvolvimento , Biodiversidade , Borrelia/genética , Borrelia/isolamento & purificação , Borrelia/patogenicidade , Cervos/parasitologia , Ecossistema , Feminino , Humanos , Ixodes/crescimento & desenvolvimento , Ixodidae/crescimento & desenvolvimento , Masculino , RNA Ribossômico 16S/genética , Rickettsia/genética , Rickettsia/isolamento & purificação , Rickettsia/patogenicidade , Especificidade da Espécie , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/transmissão , Virginia
12.
Environ Pollut ; 262: 114351, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32443221

RESUMO

Forest understory plant communities in the eastern United States are often diverse and are potentially sensitive to changes in climate and atmospheric inputs of nitrogen caused by air pollution. In recent years, empirical and processed-based mathematical models have been developed to investigate such changes in plant communities. In the study reported here, a robust set of understory vegetation response functions (expressed as version 2 of the Probability of Occurrence of Plant Species model for the United States [US-PROPS v2]) was developed based on observations of forest understory and grassland plant species presence/absence and associated abiotic characteristics derived from spatial datasets. Improvements to the US-PROPS model, relative to version 1, were mostly focused on inclusion of additional input data, development of custom species-level input datasets, and implementation of methods to address uncertainty. We investigated the application of US-PROPS v2 to evaluate the potential impacts of atmospheric nitrogen (N) and sulfur (S) deposition, and climate change on forest ecosystems at three forested sites located in New Hampshire, Virginia, and Tennessee in the eastern United States. Species-level N and S critical loads (CLs) were determined under ambient deposition at all three modeled sites. The lowest species-level CLs of N deposition at each site were between 2 and 11 kg N/ha/yr. Similarly, the lowest CLs of S deposition, based on the predicted soil pH response, were less than 2 kg S/ha/yr among the three sites. Critical load exceedance was found at all three model sites. The New Hampshire site included the largest percentage of species in exceedance. Simulated warming air temperature typically resulted in lower maximum occurrence probability, which contributed to lower CLs of N and S deposition. The US-PROPS v2 model, together with the PROPS-CLF model to derive CL functions, can be used to develop site-specific CLs for understory plants within broad regions of the United States. This study demonstrates that species-level CLs of N and S deposition are spatially variable according to the climate, light availability, and soil characteristics at a given location. Although the species niche models generally performed well in predicting occurrence probability, there remains uncertainty with respect to the accuracy of reported CLs. As such, the specific CLs reported here should be considered as preliminary estimates.


Assuntos
Poluição do Ar , Mudança Climática , Ecossistema , Florestas , Nitrogênio/análise , Tennessee , Estados Unidos , Virginia
13.
Parasit Vectors ; 13(1): 188, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32276649

RESUMO

BACKGROUND: Vector-borne diseases are a major public health concern and cause significant morbidity and mortality. Zika virus (ZIKV) is the etiologic agent of a massive outbreak in the Americas that originated in Brazil in 2015 and shows a strong association with congenital ZIKV syndrome in newborns. Cache Valley virus (CVV) is a bunyavirus that causes mild to severe illness in humans and ruminants. In this study, we investigated the vector competence of Virginia mosquitoes for ZIKV and CVV to explore their abilities to contribute to potential outbreaks. METHODS: To determine vector competence, mosquitoes were fed a blood meal comprised of defibrinated sheep blood and virus. The presence of midgut or salivary gland barriers to ZIKV infection were determined by intrathoracic inoculation vs oral infection. After 14-days post-exposure, individual mosquitoes were separated into bodies, legs and wings, and saliva expectorant. Virus presence was detected by plaque assay to determine midgut infection, dissemination, and transmission rates. RESULTS: Transmission rates for Ae. albopictus orally infected (24%) and intrathoracically inoculated (63%) with ZIKV was similar to Ae. aegypti (48% and 71%, respectively). Transmission rates of ZIKV in Ae. japonicus were low, and showed evidence of a midgut infection barrier demonstrated by low midgut infection and dissemination rates from oral infection (3%), but increased transmission rates after intrathoracic inoculation (19%). Aedes triseriatus was unable to transmit ZIKV following oral infection or intrathoracic inoculation. CVV transmission was dose-dependent where mosquitoes fed high titer (ht) virus blood meals developed higher rates of midgut infection, dissemination, and transmission compared to low titer (lt) virus blood meals. CVV was detected in the saliva of Ae. albopictus (ht: 68%, lt: 24%), Ae. triseriatus (ht: 52%, lt: 7%), Ae. japonicus (ht: 22%, lt: 0%) and Ae. aegypti (ht: 10%; lt: 7%). Culex pipiens and Cx. restuans were not competent for ZIKV or CVV. CONCLUSIONS: This laboratory transmission study provided further understanding of potential ZIKV and CVV transmission cycles with Aedes mosquitoes from Virginia. The ability for these mosquitoes to transmit ZIKV and CVV make them a public health concern and suggest targeted control programs by mosquito and vector abatement districts.


Assuntos
Vírus Bunyamwera/isolamento & purificação , Mosquitos Vetores/virologia , Zika virus/isolamento & purificação , Aedes/virologia , Animais , Bioensaio , Sangue/virologia , Infecções por Bunyaviridae/transmissão , Culex/virologia , Vetores de Doenças , Humanos , Intestinos/virologia , Saliva/virologia , Estados Unidos , Carga Viral , Virginia , Infecção por Zika virus/transmissão
14.
J Environ Manage ; 262: 110262, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32250778

RESUMO

The preservation of salt marshes under rapid sea-level rise (SLR) typically requires the conservation of marsh transgression zones-undeveloped uplands onto which marshes can migrate. Optimal planning for conservation of this type requires information on the expected benefit of marsh conservation and the cost of land suitable for marsh migration in particular areas. While information is available on marsh benefits within the literature, prior research provides little insight on associated land conservation costs. The coastal hedonic pricing literature focuses primarily on developed land, and there are no models designed to predict the cost of conserving land suitable for marsh migration. This paper develops a hedonic property value model to predict cost and explore price patterns associated with purchases of undeveloped land suitable for salt marsh migration under SLR. The model is illustrated using a case study from the Eastern Shore of Virginia, with a dataset consisting of open-market sales of undeveloped land from 2014 to 2017. Particular attention is paid to characteristics that determine marsh migration potential such as coastal distance, elevation and connectivity. Results demonstrate the insight for conservation planning that can be provided by models of this type and the errors associated with the use of simplified proxies to predict conservation costs of land suitable for marsh migration.


Assuntos
Conservação dos Recursos Naturais , Áreas Alagadas , Análise Custo-Benefício , Virginia
15.
Plant Dis ; 104(5): 1390-1399, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32223639

RESUMO

Late and early leaf spot, respectively caused by Nothopassalora personata and Passalora arachidicola, are damaging diseases of peanut (Arachis hypogaea) capable of defoliating canopies and reducing yield. Although one of these diseases may be more predominant in a given area, both are important on a global scale. To assist informed management decisions and quantify relationships between end-of-season defoliation and yield loss, meta-analyses were conducted over 140 datasets meeting established criteria. Slopes of proportion yield loss with increasing defoliation were estimated separately for Virginia and runner market type cultivars. Yield loss for Virginia types was described by an exponential function over the range of defoliation levels, with a loss increase of 1.2 to 2.2% relative to current loss levels per additional percent defoliation. Results for runner market type cultivars showed yield loss to linearly increase 2.2 to 2.8% per 10% increase in defoliation for levels up to approximately 95% defoliation, after which the rate of yield loss was exponential. Defoliation thresholds to prevent economic yield loss for Virginia and runner types were estimated at 40 and 50%, respectively. Although numerous factors remain important in mitigating overall yield losses, the integration of these findings should aid recommendations about digging under varying defoliation intensities and peanut maturities to assist in minimizing yield losses.


Assuntos
Arachis , Ascomicetos , Virginia
16.
Mar Pollut Bull ; 154: 111002, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32174483

RESUMO

In response to the oil spill caused by the collision between the Ro-Ro ship Ulysse and CSL Virginia on 7th October 2018, the Lagrangian oil spill model MEDSLIK-II was utilized to predict spill transport and fate. Oil drift was forced by the high-resolution sea circulation provided by CMEMS and the ECMWF wind. Successive model runs were restarted 5 times with the distinct overflight- and satellite-derived observations provided by REMPEC and the Copernicus Sentinel-1 mission. The results were verified based on the ability to predict the first oil-beaching event that happened near Saint-Tropez (France) in the early afternoon of 16th October. Despite the general consistency among the runs, only the last initialization was able to forecast the oil beaching. Stochastic MEDSLIK-II simulations forced by the historical meteo-oceanographic datasets 2014-2018 revealed that the coastlines between Cap Lardier and the Gulf of Saint-Tropez were among the most impacted areas.


Assuntos
Monitoramento Ambiental , Modelos Teóricos , Poluição por Petróleo , França , Virginia , Vento
17.
Environ Sci Technol ; 54(8): 4974-4983, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32142613

RESUMO

Petroleum products and essential oils are complex mixtures of hydrophobic and volatile chemicals and are categorized as substances of unknown or variable composition, complex reaction products, or biological materials (UVCBs). In aquatic testing and research of such mixtures, it is challenging to establish initial concentrations without the addition of cosolvents, to maintain constant concentrations during the test, and to keep a constant mixture composition in dilution series and throughout test duration. Passive dosing was here designed to meet these challenges by maximizing the surface area (Adonor/Vmedium = 3.8 cm2/mL) and volume (Vdonor/Vmedium > 0.1 L/L) of the passive dosing donor in order to ensure rapid mass transfer and avoid donor depletion for all mixture constituents. Cracked gas oil, cedarwood Virginia oil, and lavender oil served as model mixtures. This study advances the field by (i) showing accelerated passive dosing kinetics for 68 cracked gas oil constituents with typical equilibration times of 5-10 min and for 21 cederwood Virginia oil constituents with typical equilibration times < 1 h, (ii) demonstrating how to control mixture concentration and composition in aquatic tests, and (iii) discussing the fundamental differences between solvent spiking, water-accommodated fractions, and passive dosing.


Assuntos
Petróleo , Poluentes Químicos da Água/análise , Misturas Complexas , Interações Hidrofóbicas e Hidrofílicas , Virginia
18.
Sci Justice ; 60(2): 173-179, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32111291

RESUMO

Blow flies are common primary colonizers of carrion, play an important role in the transfer of microbes between environments, and serve as a vector for many human pathogens. While some investigation has begun regarding the bacteria associated with different life stages of blow flies, a well replicated study is currently not available for the majority of blow flies. This study investigated bacteria associated with successive life stages of blow fly species Lucilia sericata and Phormia regina. A total of 38 samples were collected from four true replicates of L. sericata and P. regina. Variable region four (V4) of 16S ribosomal DNA (16S rDNA) was amplified and sequenced on MiSeq FGx sequencing platform using universal 16S rDNA primers and dual-index sequencing strategy. Bacterial communities associated with different life stages of L. sericata and P. regina didn't differ significantly from each other. In both blow fly species, Bacilli (e.g., Lactococcus) and Gammaproteobacteria (e.g., Providencia) constituted >95% of all bacterial classes across all life stages. At the genus level, Vagococcus and Leuconostoc were present at relatively high abundances in L. sericata whereas Yersinia and Proteus were present at comparatively high abundances in P. regina. Overall, information on bacterial structures associated with various life stages of blow flies can help scientists in better understanding or management of vector-borne pathogen dispersal and in increasing the accuracy of microbial evidence based postmortem interval (PMI) prediction models.


Assuntos
Bactérias/classificação , Dípteros/crescimento & desenvolvimento , Dípteros/microbiologia , Entomologia Forense , Animais , Microbiota , Análise de Sequência de DNA , Virginia
19.
Artigo em Inglês | MEDLINE | ID: mdl-32150930

RESUMO

This article describes a collaboration among a group of university faculty, undergraduate students, local governments, local residents, and U.S. Army staff to address long-standing concerns about the environmental health effects of an Army ammunition plant. The authors describe community-responsive scientific pilot studies that examined potential environmental contamination and a related undergraduate research course that documented residents' concerns, contextualized those concerns, and developed recommendations. We make a case for the value of resource-intensive university-community partnerships that promote the production of knowledge through collaborations across disciplinary paradigms (natural/physical sciences, social sciences, health sciences, and humanities) in response to questions raised by local residents. Our experience also suggests that enacting this type of research through a university class may help promote researchers' adoption of "epistemological pluralism", and thereby facilitate the movement of a study from being "multidisciplinary" to "transdisciplinary".


Assuntos
Saúde Ambiental , Saúde Pública , Parcerias Público-Privadas , Humanos , Comunicação Interdisciplinar , Pesquisadores , Universidades , Virginia
20.
Dis Colon Rectum ; 63(4): 538-544, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32015289

RESUMO

BACKGROUND: The implementation of protocolized care pathways has resulted in major improvements in surgical outcomes. Additional gains will require focused efforts to alter preexisting risk. Prehabilitation programs provide a promising avenue for risk reduction. OBJECTIVE: This study used wearable technology to monitor activity levels before colorectal surgery to evaluate the impact of preoperative activity on postoperative outcomes. DESIGN: This was a prospective nonrandomized observational study. SETTINGS: The study was conducted at a large academic medical center. PATIENTS: Patients undergoing elective colorectal surgery from January 2018 to February 1, 2019, were included. MAIN OUTCOME MEASURES: Patients were trained in the usage of wearable activity-tracking devices and instructed to wear the device for 30 days before surgery. Patients were stratified as active (≥5000 steps per day) and inactive (<5000 steps per day) based on preoperative step counts. Univariate analyses compared postoperative outcomes. Multivariable regression models analyzed the impact of preoperative activity on postoperative complications, adjusting for each patient's baseline risk as calculated using the American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator. Models were rerun without the addition of activity and the predictive ability of the models compared. RESULTS: Ninety-nine patients were included, with 40 (40.4%) classified as active. Active patients experienced fewer overall complications (11/40 (27.5%) vs 33/59 (55.9%); p = 0.005) and serious complications (2/40 (5%) vs 12/59 (20.3%); p = 0.032). Increased preoperative activity was associated with a decreased risk of any postoperative complication (OR = 0.386; p = 0.0440) on multivariable analysis. The predictive ability of the models for complications and serious complications was improved with the addition of physical activity. LIMITATIONS: The study was limited by its small sample size and single institution. CONCLUSIONS: There is significant room for improvement in baseline preoperative activity levels of patients undergoing colorectal surgery, and poor activity is associated with increased postoperative complications. These data will serve as the basis for an interventional trial investigating whether wearable devices help improve surgical outcomes through a monitored preoperative exercise program. See Video Abstract at http://links.lww.com/DCR/B145. TECNOLOGÍA PORTÁTIL EN EL PERÍODO PERIOPERATORIO: PREDICCIÓN DEL RIESGO DE COMPLICACIONES POSTOPERATORIAS EN PACIENTES SOMETIDOS A CIRUGÍA COLORRECTAL ELECTIVA: La implementación de vías de atención protocolizadas ha dado lugar a importantes mejoras en los resultados quirúrgicos. Para obtener más beneficios será necesario realizar esfuerzos concentrados para modificar el riesgo preexistente. Los programas de rehabilitación proporcionan una vía prometedora para la reducción del riesgo.Este estudio utilizó tecnología portátil para monitorear los niveles de actividad antes de la cirugía colorrectal para evaluar el impacto de la actividad preoperatoria en los resultados postoperatorios.Estudio observacional prospectivo no aleatorizado.Gran centro médico académico.Pacientes sometidos a cirugía colorrectal electiva desde enero de 2018 hasta el 1 de febrero de 2019.Los pacientes fueron entrenados en el uso de dispositivos portátiles para el seguimiento de la actividad y se les indicó usar el dispositivo durante 30 días antes de la cirugía. Los pacientes fueron estratificados como activos (> 5000 pasos / día) e inactivos (<5000 pasos / día) en base a los recuentos de pasos preoperatorios. Los análisis univariados compararon los resultados postoperatorios. Los modelos de regresión multivariable analizaron el impacto de la actividad preoperatoria en las complicaciones postoperatorias, ajustando el riesgo de referencia de cada paciente según lo calculado utilizando la Calculadora de riesgo quirúrgico del Programa Nacional de Mejora de la Calidad Quirúrgica del Colegio Americano de Cirujanos. Los modelos se volvieron a ejecutar sin agregar actividad, y se comparó la capacidad de predicción de los modelos.Noventa y nueve pacientes fueron incluidos con 40 (40.4%) clasificados como activos. Los pacientes activos experimentaron menos complicaciones generales [11/40 (27,5%) frente a 33/59 (55,9%); p = 0,005] y complicaciones graves [2/40 (5%) frente a 12/59 (20,3%); p = 0,032]. El aumento de la actividad preoperatoria se asoció con una disminución del riesgo de cualquier complicación postoperatoria (OR 0.386, p = 0.0440) en el análisis multivariable. La capacidad predictiva de los modelos para complicaciones y complicaciones graves mejoró con la adición de actividad física.Tamaño de muestra pequeño, una sola institución.Existe un margen significativo para mejorar los niveles basales de actividad preoperatoria de los pacientes de cirugía colorrectal, y la escasa actividad se asocia con mayores complicaciones postoperatorias. Estos datos servirán de base para un ensayo intervencionista que investigue si los dispositivos portátiles ayudan a mejorar los resultados quirúrgicos a través de un programa de ejercicio preoperatorio monitoreado. Consulte Video Resumen en http://links.lww.com/DCR/B145.


Assuntos
Colectomia/métodos , Procedimentos Cirúrgicos Eletivos/métodos , Complicações Pós-Operatórias/prevenção & controle , Melhoria de Qualidade , Medição de Risco/métodos , Dispositivos Eletrônicos Vestíveis , Adulto , Idoso , Feminino , Seguimentos , Humanos , Incidência , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Período Perioperatório , Complicações Pós-Operatórias/epidemiologia , Prognóstico , Estudos Prospectivos , Fatores de Risco , Virginia/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA