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1.
Plants (Basel) ; 12(5)2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36904044

RESUMO

Although several studies have shown increased native plant establishment with native microbe soil amendments, few studies have investigated how microbes can alter seedling recruitment and establishment in the presence of a non-native competitor. In this study, the effect of microbial communities on seedling biomass and diversity was assessed by seeding pots with both native prairie seeds and a non-native grass that commonly invades US grassland restorations, Setaria faberi. Soil in the pots was inoculated with whole soil collections from ex-arable land, late successional arbuscular mycorrhizal (AM) fungi isolated from a nearby tallgrass prairie, with both prairie AM fungi and ex-arable whole soil, or with a sterile soil (control). We hypothesized (1) late successional plants would benefit from native AM fungi, (2) that non-native plants would outcompete native plants in ex-arable soils, and (3) early successional plants would be unresponsive to microbes. Overall, native plant abundance, late successional plant abundance, and total diversity were greatest in the native AM fungi+ ex-arable soil treatment. These increases led to decreased abundance of the non-native grass S. faberi. These results highlight the importance of late successional native microbes on native seed establishment and demonstrate that microbes can be harnessed to improve both plant community diversity and resistance to invasion during the nascent stages of restoration.

2.
J Agric Biol Environ Stat ; 28(1): 1-19, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36779040

RESUMO

In grassland ecosystems, it is well known that increasing plant species diversity can improve ecosystem functions (i.e., ecosystem responses), for example, by increasing productivity and reducing weed invasion. Diversity-Interactions models use species proportions and their interactions as predictors in a regression framework to assess biodiversity and ecosystem function relationships. However, it can be difficult to model numerous interactions if there are many species, and interactions may be temporally variable or dependent on spatial planting patterns. We developed a new Diversity-Interactions mixed model for jointly assessing many species interactions and within-plot species planting pattern over multiple years. We model pairwise interactions using a small number of fixed parameters that incorporate spatial effects and supplement this by including all pairwise interaction variables as random effects, each constrained to have the same variance within each year. The random effects are indexed by pairs of species within plots rather than a plot-level factor as is typical in mixed models, and capture remaining variation due to pairwise species interactions parsimoniously. We apply our novel methodology to three years of weed invasion data from a 16-species grassland experiment that manipulated plant species diversity and spatial planting pattern and test its statistical properties in a simulation study.Supplementary materials accompanying this paper appear online. Supplementary materials for this article are available at 10.1007/s13253-022-00505-2.

3.
Sci Data ; 9(1): 744, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36460674

RESUMO

The Chesapeake Bay is a region along the eastern coast of the United States where sea-level rise is confounded with poorly resolved rates of land subsidence, thus new constraints on vertical land motions (VLM) in the region are warranted. In this paper, we provide a description of two campaign-style Global Positioning System (GPS) datasets, explain the methods used in data collection and validation, and present the experiment designed to quantify a new baseline of VLM in the Chesapeake Bay region of eastern North America. Data from GPS campaigns in 2019 and 2020 are presented as ASCII RINEX2.11 files and logsheets for each observation from the campaigns. Data were quality checked using the open-source program TEQC, resulting in average multipath 1 and 2 values of 0.68 and 0.57, respectively. All data are archived and publicly available for open access at the geodesy facility UNAVCO to abide by Findable, Accessible, Interoperable, Reusable (FAIR) data principles.

4.
PLoS One ; 15(6): e0234546, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32589642

RESUMO

Perennial crops in agricultural systems can increase sustainability and the magnitude of ecosystem services, but yield may depend upon biotic context, including soil mutualists, pathogens and cropping diversity. These biotic factors themselves may interact with abiotic factors such as drought. We tested whether perennial crop yield depended on soil microbes, water availability and crop diversity by testing monocultures and mixtures of three perennial crop species: a novel perennial grain (intermediate wheatgrass-Thinopyrum intermedium-- that produces the perennial grain Kernza®), a potential perennial oilseed crop (Silphium intregrifolium), and alfalfa (Medicago sativa). Perennial crop performance depended upon both water regime and the presence of living soil, most likely the arbuscular mycorrhizal (AM) fungi in the whole soil inoculum from a long term perennial monoculture and from an undisturbed native remnant prairie. Specifically, both Silphium and alfalfa strongly benefited from AM fungi. The presence of native prairie AM fungi had a greater benefit to Silphium in dry pots and alfalfa in wet pots than AM fungi present in the perennial monoculture soil. Kernza did not benefit from AM fungi. Crop mixtures that included Kernza overyielded, but overyielding depended upon inoculation. Specifically, mixtures with Kernza overyielded most strongly in sterile soil as Kernza compensated for poor growth of Silphium and alfalfa. This study identifies the importance of soil biota and the context dependence of benefits of native microbes and the overyielding of mixtures in perennial crops.


Assuntos
Agricultura , Medicago sativa/fisiologia , Plantas Daninhas/crescimento & desenvolvimento , Estresse Fisiológico/fisiologia , Biota/fisiologia , Produtos Agrícolas/fisiologia , Ecossistema , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/microbiologia , Micorrizas/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Poaceae/crescimento & desenvolvimento , Poaceae/microbiologia , Microbiologia do Solo , Simbiose/fisiologia
5.
PLoS One ; 15(1): e0228202, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31999724

RESUMO

The use of perennial crop species in agricultural systems may increase ecosystem services and sustainability. Because soil microbial communities play a major role in many processes on which ecosystem services and sustainability depend, characterization of soil community structure in novel perennial crop systems is necessary to understand potential shifts in function and crop responses. Here, we characterized soil fungal community composition at two depths (0-10 and 10-30 cm) in replicated, long-term plots containing one of three different cropping systems: a tilled three-crop rotation of annual crops, a novel perennial crop monoculture (Intermediate wheatgrass, which produces the grain Kernza®), and a native prairie reconstruction. The overall fungal community was similar under the perennial monoculture and native vegetation, but both were distinct from those in annual agriculture. The mutualist and saprotrophic community subsets mirrored differences of the overall community, but pathogens were similar among cropping systems. Depth structured overall communities as well as each functional group subset. These results reinforce studies showing strong effects of tillage and sampling depth on soil community structure and suggest plant species diversity may play a weaker role. Similarities in the overall and functional fungal communities between the perennial monoculture and native vegetation suggest Kernza® cropping systems have the potential to mimic reconstructed natural systems.


Assuntos
Produção Agrícola , Micobioma , Poaceae/crescimento & desenvolvimento , Microbiologia do Solo , Produção Agrícola/métodos , Fungos/classificação , Fungos/isolamento & purificação , Poaceae/microbiologia
6.
Ecol Evol ; 9(21): 12171-12181, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31832151

RESUMO

Biodiversity and Ecosystem Function analyses aim to explain how individual species and their interactions affect ecosystem function. With this study, we asked in what ways do species interact, are these interactions affected by species planting pattern, and are initial (planted) proportions or previous year (realized) proportions a better reference point for characterizing grassland diversity effects?We addressed these questions with experimental communities compiled from a pool of 16 tallgrass prairie species. We planted all species in monocultures and mixtures that varied in their species richness, evenness, and spatial pattern. We recorded species-specific biomass production over three growing seasons and fitted Diversity-Interactions (DI) models to annual plot biomass yields.In the establishment season, all species interacted equally to form the diversity effect. In years 2 and 3, each species contributed a unique additive coefficient to its interaction with every other species to form the diversity effect. These interactions were affected by Helianthus maximiliani and the species planting pattern. Models based on species planted proportions better-fit annual plot yield than models based on species previous contributions to plot biomass.Outcomes suggest that efforts to plant tallgrass prairies to maximize diversity effects should focus on the specific species present and in what arrangement they are planted. Furthermore, for particularly diverse grasslands, the effort of collecting annual species biomass data may not be necessary when quantifying diversity effects with DI models.

7.
Sci Total Environ ; 688: 231-242, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31229820

RESUMO

Global climate change is expected to significantly influence soil respiration. When limited, rainfall and nitrogen (N) deposition strongly modify soil respiration in a broad range of biomes, but uncertainty remains with regards to the influence of the interactions of seasonal rainfall distribution and N deposition on soil respiration in an arid steppe. In the present study, we manipulated precipitation using V-shaped plexiglass gutters (minus 50%, control, and plus 50% treatments) and tested various N additions (control and plus 35 kg N ha-1 yr-1) to evaluate their impact on soil respiration, measured using a Li-Cor 8100, in a desert steppe in China. Increased precipitation stimulated soil respiration by 26.1%, while decreased precipitation significantly reduced soil respiration by 10.8%. There was a significant increase in soil respiration under N addition at 11.5%. Statistical assessment of their interactions demonstrated that N supplementation strengthened the stimulation of soil respiration under increased precipitation, whereas decreased precipitation offset the positive impact of N addition and led to a reduction in soil respiration. Contrasting interannual precipitation patterns strongly influenced the temporal changes in soil respiration as well as its response to N addition, indicating that the desert steppe plant community was co-limited by water and N. Net primary productivity (aboveground and belowground) predominantly drove soil respiration under altered precipitation and N addition. As grasses are better equipped for water deficit due to their previous exposure to long periods without water, there could be a shift from forb to grass communities under drier conditions. These findings highlight the importance of assessing the differential impacts of plant traits and soil physiochemical properties on soil respiration under altered precipitation and N addition.


Assuntos
Monitoramento Ambiental , Nitrogênio/análise , Carbono/análise , China , Mudança Climática , Clima Desértico , Ecossistema , Plantas , Poaceae , Chuva/química , Solo/química , Microbiologia do Solo , Água
8.
Health Phys ; 114(5): 538, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29578902
9.
Ecol Evol ; 6(16): 5788-95, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27547354

RESUMO

Plant performance is determined by the balance of intra- and interspecific neighbors within an individual's zone of influence. If individuals interact over smaller scales than the scales at which communities are measured, then altering neighborhood interactions may fundamentally affect community responses. These interactions can be altered by changing the number (species richness), abundances (species evenness), and positions (species pattern) of the resident plant species, and we aimed to test whether aggregating species at planting would alter effects of species richness and evenness on biomass production at a common scale of observation in grasslands. We varied plant species richness (2, 4, or 8 species and monocultures), evenness (0.64, 0.8, or 1.0), and pattern (planted randomly or aggregated in groups of four individuals) within 1 × 1 m plots established with transplants from a pool of 16 tallgrass prairie species and assessed plot-scale biomass production and diversity over the first three growing seasons. As expected, more species-rich plots produced more biomass by the end of the third growing season, an effect associated with a shift from selection to complementarity effects over time. Aggregating conspecifics at a 0.25-m scale marginally reduced biomass production across all treatments and increased diversity in the most even plots, but did not alter biodiversity effects or richness-productivity relationships. Results support the hypothesis that fine-scale species aggregation affects diversity by promoting species coexistence in this system. However, results indicate that inherent changes in species neighborhood relationships along grassland diversity gradients may only minimally affect community (meter) - scale responses among similarly designed biodiversity-ecosystem function studies. Given that species varied in their responses to local aggregation, it may be possible to use such species-specific results to spatially design larger-scale grassland communities to achieve desired diversity and productivity responses.

10.
J Wildl Dis ; 52(4): 862-873, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27525593

RESUMO

There is limited information on the pathogenesis and epidemiology of foot-and-mouth disease (FMD) in North American wildlife and none concerning pronghorn ( Antilocapra americana ). In an experimental study of 13 pronghorn and six steers ( Bos taurus ), we compared the susceptibility of pronghorn to FMD virus (FMDV) strain O, with that of cattle ( Bos taurus ). We also determined the potential for intra- and interspecies transmission of FMDV strain O in pronghorn and cattle, assessed the application of conventional laboratory tests in their suitability to detect FMDV infection in pronghorn, and evaluated the potential role of pronghorn as efficient long-term carriers of FMDV. After acclimation to containment at Plum Island Animal Disease Center, two pronghorn and one steer were each infected by intraepithelial tongue inoculation with 10,000 bovine tongue infective doses of FMDV, strain O1 Manisa. Inoculated animals were housed with contact animals. When contact-exposed animals developed fever they were placed in rooms with previously unexposed animals. All inoculated and exposed cattle and pronghorn developed clinical disease typical of FMD. Pronghorn developed severe foot lesions and mild to moderate oral lesions, primarily on the tongue. Duration of clinical signs in both species was 2-3 wk with foot abnormalities evident to the end of the study (51 d postexposure). Other lesions included pancreatitis, myositis of the tongue, and secondary lesions including pleuritis, pneumonia, decubital ulcers, and tenosynovitis. Virus transmission occurred between pronghorn, from cattle to pronghorn, and from pronghorn to cattle. Conventional laboratory tests detected virus and antibodies against nonstructural and structural FMDV proteins in pronghorn and cattle. Virus was present in some animals for 1 wk but was not detectable by virus isolation or PCR at 3 wk postinfection or afterward.


Assuntos
Animais Selvagens , Vírus da Febre Aftosa , Febre Aftosa , Animais , Bovinos , Doenças dos Bovinos , Ovinos , Vacinação
11.
Health Phys ; 108(1): 15-31, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25437516

RESUMO

Experience from past nuclear and radiological emergencies shows that placing the radiological health hazard in perspective and having a definition of "safe" are required in order to prevent members of the public, those responsible for protecting the public (i.e., decision makers), and others from taking inappropriate and damaging actions that are not justified based on the radiological health hazard. The principle concerns of the public during a severe nuclear power plant or spent fuel pool emergency are "Am I safe?" and "What should I do to be safe?" However, these questions have not been answered to the satisfaction of the public, despite various protective actions being implemented to ensure their safety. Instead, calculated doses or various measured quantities (e.g., ambient dose rate or radionuclide concentrations) are used to describe the situation to the public without placing them into perspective in terms of the possible radiological health hazard, or if they have, it has been done incorrectly. This has contributed to members of the public taking actions that do more harm than good in the belief that they are protecting themselves. Based on established international guidance, this paper provides a definition of "safe" for the radiological health hazard for use in nuclear or radiological emergencies and a system for putting the radiological health hazard in perspective for quantities most commonly measured after a release resulting from a severe emergency at a light water reactor or its spent fuel pool.


Assuntos
Emergências , Centrais Nucleares , Liberação Nociva de Radioativos , Saúde Radiológica , Exposição Ambiental/prevenção & controle , Humanos , Doses de Radiação , Lesões por Radiação/prevenção & controle , Monitoramento de Radiação/métodos , Proteção Radiológica/métodos , Liberação Nociva de Radioativos/prevenção & controle , Medição de Risco , Gestão da Segurança
12.
Dig Dis Sci ; 57(12): 3098-105, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22711499

RESUMO

BACKGROUND: Four liters of polyethylene glycol 3350 (PEG) with balanced electrolytes for colonoscopy preparation has had poor acceptance. Another approach is the use of electrolyte-free PEG combined with 1.9 L of Gatorade. Despite its widespread use, there are no data on metabolic safety and minimal data on efficacy. Our aim was to assess the efficacy and electrolyte safety of these two PEG-based preparations. METHODS: This was a prospective, randomized, single-blind, non-inferiority trial. Patients were randomized to 238 g PEG + 1.9 L Gatorade or 4 L of PEG-ELS containing 236 g PEG. Split dosing was not performed. On procedure day blood was drawn for basic chemistries. The primary outcome was preparation quality from procedure photos using the Boston Bowel Preparation Scale. RESULTS: We randomized 136 patients (66 PEG + Gatorade, 70 PEG-ELS). There were no differences in preparation scores between the two agents in the ITT analysis (7.2 ± 1.9 for PEG-ELS and 7.0 ± 2.1 for PEG + Gatorade; p = 0.45). BBPS scores were identical for those who completed the preparation and dietary instructions as directed (7.4 ± 1.7 for PEG-ELS, and 7.4 ± 1.8 for PEG + Gatorade; p = 0.98). There were no statistical differences in serum electrolytes between the two preparations. Patients who received PEG + Gatorade gave higher overall satisfaction scores for the preparation experience (p = 0.001), and had fewer adverse effects. CONCLUSIONS: Use of 238 g PEG + 1.9 L Gatorade appears to be safe, better tolerated, and non-inferior to 4 L PEG-ELS. This preparation may be especially useful for patients who previously tolerated PEG-ELS poorly.


Assuntos
Catárticos/farmacologia , Colonoscopia , Eletrólitos/farmacologia , Soluções Isotônicas/farmacologia , Polietilenoglicóis/farmacologia , Quimioterapia Combinada , Eletrólitos/administração & dosagem , Feminino , Humanos , Soluções Isotônicas/administração & dosagem , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/administração & dosagem , Método Simples-Cego , Resultado do Tratamento
13.
Shock ; 31(6): 574-80, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19008777

RESUMO

Respiratory rate (RR) is a basic vital sign, measured and monitored throughout a wide spectrum of health care settings, although RR is historically difficult to measure in a reliable fashion. We explore an automated method that computes RR only during intervals of clean, regular, and consistent respiration and investigate its diagnostic use in a retrospective analysis of prehospital trauma casualties. At least 5 s of basic vital signs, including heart rate, RR, and systolic, diastolic, and mean arterial blood pressures, were continuously collected from 326 spontaneously breathing trauma casualties during helicopter transport to a level I trauma center. "Reliable" RR data were identified retrospectively using automated algorithms. The diagnostic performances of reliable versus standard RR were evaluated by calculation of the receiver operating characteristic curves using the maximum-likelihood method and comparison of the summary areas under the receiver operating characteristic curves (AUCs). Respiratory rate shows significant data-reliability differences. For identifying prehospital casualties who subsequently receive a respiratory intervention (hospital intubation or tube thoracotomy), standard RR yields an AUC of 0.59 (95% confidence interval, 0.48-0.69), whereas reliable RR yields an AUC of 0.67 (0.57-0.77), P < 0.05. For identifying casualties subsequently diagnosed with a major hemorrhagic injury and requiring blood transfusion, standard RR yields an AUC of 0.60 (0.49-0.70), whereas reliable RR yields 0.77 (0.67-0.85), P < 0.001. Reliable RR, as determined by an automated algorithm, is a useful parameter for the diagnosis of respiratory pathology and major hemorrhage in a trauma population. It may be a useful input to a wide variety of clinical scores and automated decision-support algorithms.


Assuntos
Monitorização Fisiológica/métodos , Respiração , Pressão Sanguínea/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Hemorragia/diagnóstico , Humanos , Masculino , Estudos Retrospectivos
14.
J Trauma ; 65(4): 915-23, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18849811

RESUMO

BACKGROUND: Prehospital severity scores can be used in routine prehospital care, mass casualty care, and military triage. If computers could reliably calculate clinical scores, new clinical and research methodologies would be possible. One obstacle is that vital signs measured automatically can be unreliable. We hypothesized that Signal Quality Indices (SQI's), computer algorithms that differentiate between reliable and unreliable monitored physiologic data, could improve the predictive power of computer-calculated scores. METHODS: In a retrospective analysis of trauma casualties transported by air ambulance, we computed the Triage Revised Trauma Score (RTS) from archived travel monitor data. We compared the areas-under-the-curve (AUC's) of receiver operating characteristic curves for prediction of mortality and red blood cell transfusion for 187 subjects with comparable quantities of good-quality and poor-quality data. RESULTS: Vital signs deemed reliable by SQI's led to significantly more discriminatory severity scores than vital signs deemed unreliable. We also compared automatically-computed RTS (using the SQI's) versus RTS computed from vital signs documented by medics. For the subjects in whom the SQI algorithms identified 15 consecutive seconds of reliable vital signs data (n = 350), the automatically-computed scores' AUC's were the same as the medic-based scores' AUC's. Using the Prehospital Index in place of RTS led to very similar results, corroborating our findings. CONCLUSIONS: SQI algorithms improve automatically-computed severity scores, and automatically-computed scores using SQI's are equivalent to medic-based scores.


Assuntos
Algoritmos , Documentação/métodos , Processamento Eletrônico de Dados , Índices de Gravidade do Trauma , Triagem , Ferimentos e Lesões/diagnóstico , Resgate Aéreo , Serviços Médicos de Emergência/normas , Feminino , Humanos , Masculino , Militares , Monitorização Fisiológica/métodos , Controle de Qualidade , Estudos Retrospectivos , Sensibilidade e Especificidade , Transporte de Pacientes , Ferimentos e Lesões/classificação
15.
J Wildl Dis ; 44(2): 269-79, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18436660

RESUMO

There is limited information about the pathogenesis and epidemiology of foot-and-mouth disease (FMD) in North American bison (Bison bison) or elk (Cervus elaphus nelsoni). In these two experimental infection studies, we compared the susceptibilities of bison and elk to FMD virus (FMDV), respectively, with that of cattle; determined whether intra- and interspecies transmission could occur in bison and cattle, and elk and cattle; determined suitability of conventional available laboratory tests to detect FMDV infection in bison and elk; and investigated whether bison or elk are efficient long-term carriers of FMDV. In both studies, after a period of acclimation to the containment at Plum Island Animal Disease Center, animals were infected by intraepithelial tongue inoculation with 10,000 bovine tongue infective doses of FMDV, strain O1 Manisa. Inoculated animals were kept with contact animals; subsequently, inoculated and/or exposed contact animals were placed in rooms with unexposed animals. All bison developed oral mucosal and foot lesions similar to those of cattle. Bison developed fever, lameness, inappetence, and ptyalism. Physical examinations on bison revealed numerous small vesicles and erosions affecting tongue, gingiva, muzzle, hard and soft palates, coronary bands, and interdigital skin. Inoculated elk developed transient fever and mild focal tongue and foot lesions. Contact elk developed neither clinical signs nor gross pathologic lesions of FMD. At necropsy, lesions in bison included numerous extensive vesicles, erosions, and/or ulcers in the oral cavities, feet, and rumen pillars depending on the stage of disease. Less extensive oral, foot, and rumen lesions were present in the inoculated elk. All bison and inoculated elk developed antibodies to FMDV and were positive for FMDV by reverse transcription-polymerase chain reaction (RT-PCR). Transmission occurred between cattle and bison, and bison and bison. It did not occur between elk and cattle. Elk-to-elk transmission studies resulted in only one contact elk developing serologic evidence of a subclinical infection. Other exposed elk developed neither clinical, pathologic, virologic, nor serologic evidence of disease. FMDV was not isolated from animals past 28 days postinfection.


Assuntos
Bison , Cervos , Vírus da Febre Aftosa/patogenicidade , Febre Aftosa/patologia , Febre Aftosa/transmissão , Animais , Bison/imunologia , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/patologia , Doenças dos Bovinos/transmissão , Cervos/imunologia , Reservatórios de Doenças/veterinária , Transmissão de Doença Infecciosa/veterinária , Febre Aftosa/imunologia , Masculino , Especificidade da Espécie , Carga Viral , Viremia/imunologia , Viremia/patologia , Viremia/transmissão , Viremia/veterinária , Eliminação de Partículas Virais
16.
J Biomed Inform ; 41(3): 469-78, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18255342

RESUMO

We present a classifier for use as a decision assist tool to identify a hypovolemic state in trauma patients during helicopter transport to a hospital, when reliable acquisition of vital-sign data may be difficult. The decision tool uses basic vital-sign variables as input into linear classifiers, which are then combined into an ensemble classifier. The classifier identifies hypovolemic patients with an area under a receiver operating characteristic curve (AUC) of 0.76 (standard deviation 0.05, for 100 randomly-reselected patient subsets). The ensemble classifier is robust; classification performance degrades only slowly as variables are dropped, and the ensemble structure does not require identification of a set of variables for use as best-feature inputs into the classifier. The ensemble classifier consistently outperforms best-features-based linear classifiers (the classification AUC is greater, and the standard deviation is smaller, p<0.05). The simple computational requirements of ensemble classifiers will permit them to function in small fieldable devices for continuous monitoring of trauma patients.


Assuntos
Inteligência Artificial , Sistemas de Apoio a Decisões Clínicas , Diagnóstico por Computador/métodos , Serviços Médicos de Emergência/métodos , Hipovolemia/diagnóstico , Ferimentos e Lesões/diagnóstico , Humanos , Hipovolemia/complicações , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ferimentos e Lesões/complicações
17.
Virus Genes ; 36(2): 401-13, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18278548

RESUMO

Foot-and-mouth disease virus (FMDV) isolates collected from various geographic locations in Afghanistan between 2003 and 2005 were genetically characterized, and their phylogeny was reconstructed utilizing nucleotide sequences of the complete VP1 coding region. Three serotypes of FMDV (types A, O, and Asia 1) were identified as causing clinical disease in Afghanistan during this period. Phylogenetic analysis revealed that the type A viruses were most closely related to isolates collected in Iran during 2002-2004. This is the first published report of serotype A in Afghanistan since 1975, therefore indicating the need for inclusion of serotype A in vaccine formulations that will be used to control disease outbreaks in this country. Serotype O virus isolates were closely related to PanAsia strains, including those that originated from Bhutan and Nepal during 2003-2004. The Asia 1 viruses, collected along the northern and eastern borders of Afghanistan, were most closely related to FMDV isolates collected in Pakistan during 2003 and 2004. Data obtained from this study provide valuable information on the FMDV serotypes circulating in Afghanistan and their genetic relationship with strains causing FMD in neighboring countries.


Assuntos
Proteínas do Capsídeo/genética , Vírus da Febre Aftosa/genética , Febre Aftosa/epidemiologia , Febre Aftosa/virologia , Genes Virais , Filogenia , Afeganistão/epidemiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteínas do Capsídeo/química , Bovinos , Vírus da Febre Aftosa/classificação , Vírus da Febre Aftosa/isolamento & purificação , Epidemiologia Molecular , Dados de Sequência Molecular , RNA Viral/análise , RNA Viral/genética , Alinhamento de Sequência , Sorotipagem
18.
Health Phys ; 93(5): 527-37, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18049230

RESUMO

In the past 25 years, nuclear and radiological emergencies have occurred that cover much of the range of causes and types that had been anticipated by experts. Experience from response to these emergencies has clearly demonstrated the importance of an efficient response system that includes, among other components, emergency plans, procedures, and internally consistent operational criteria. An analysis of lessons identified from recent responses has shown that a lack of crucial components in the emergency response system could result in major radiological and nonradiological consequences at the national level. A rigorous examination of the response to past emergencies has shown that there is a need for additional consistent international guidance on taking protective and other response actions and for placing the guidance in a context that is both comprehensive for the decision makers and can be explained to the public. This paper briefly describes the lessons learned from past radiation emergencies and how these lessons are used by the International Atomic Energy Agency in developing the international guidance in the area of emergency preparedness and response. In particular, the paper discusses the proposed extended framework of emergency response criteria. The framework is composed of two fundamental parts: (1) generic reference levels and (2) a plain language explanation for each generic reference level to assist the decisions makers and the public in making informed decisions on the actions they should take when this level is reached. The system of generic reference levels covers the full range of potential and actual exposures, from those levels that can result in severe deterministic health effects down to those that allow for a return to normality.


Assuntos
Acidente Nuclear de Chernobyl , Emergências , Cooperação Internacional , Proteção Radiológica/métodos , Guias como Assunto , Humanos , Lesões por Radiação/prevenção & controle , Gestão da Segurança
19.
Artigo em Inglês | MEDLINE | ID: mdl-18002813

RESUMO

In this study, we analyzed a dataset of time-series vital-signs data collected by standard Propaq travel monitor during helicopter transport of 898 civilian trauma casualties from the scene of injury to a receiving trauma center. The goals of the analysis are two fold. First, to determine which combination of the automatically-collected and -qualified vital signs provides the best discrimination between casualties with and without major hemorrhage. Second, to determine whether nonlinear classifiers provide improved discrimination over simpler, linear classifiers. Major hemorrhage is defined by the presence of injuries consistent with hemorrhage in casualties who received one or more units of blood. We randomly selected a subset of the casualties to train and test the classifiers with multiple combinations of the vital-signs variables, and used the area under the receiver operating characteristic curve (ROC AUC) as a decision metric. Based on the results of 100 simulations, we observe that: (i) the best two features obtained are systolic blood pressure and heart rate (mean AUC = 0.75 from a linear classifier), and (ii) the use of nonlinear classifiers does not improve discrimination. These results support earlier findings that the interaction of systolic blood pressure and heart rate is useful for the identification of trauma hemorrhage and that linear classifiers are adequate for many real-world applications.


Assuntos
Resgate Aéreo , Sistemas de Apoio a Decisões Clínicas , Diagnóstico por Computador/métodos , Hemorragia/diagnóstico , Monitorização Fisiológica/métodos , Triagem/métodos , Ferimentos e Lesões/diagnóstico , Algoritmos , Simulação por Computador , Sistemas Inteligentes , Hemorragia/etiologia , Modelos Lineares , Dinâmica não Linear , Reconhecimento Automatizado de Padrão/métodos , Medição de Risco/métodos , Fatores de Risco , Estados Unidos , Ferimentos e Lesões/complicações
20.
Comput Methods Programs Biomed ; 86(1): 62-72, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17287043

RESUMO

The physiology analysis system (PAS) was developed as a resource to support the efficient warehousing, management, and analysis of physiology data, particularly, continuous time-series data that may be extensive, of variable quality, and distributed across many files. The PAS incorporates time-series data collected by many types of data-acquisition devices, and it is designed to free users from data management burdens. This Web-based system allows both discrete (attribute) and time-series (ordered) data to be manipulated, visualized, and analyzed via a client's Web browser. All processes occur on a server, so that the client does not have to download data or any application programs, and the PAS is independent of the client's computer operating system. The PAS contains a library of functions, written in different computer languages that the client can add to and use to perform specific data operations. Functions from the library are sequentially inserted into a function chain-based logical structure to construct sophisticated data operators from simple function building blocks, affording ad hoc query and analysis of time-series data. These features support advanced mining of physiology data.


Assuntos
Gestão da Informação/organização & administração , Fisiologia/estatística & dados numéricos , Apresentação de Dados , Internet , Informática Médica , Estados Unidos
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