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1.
Evol Appl ; 16(7): 1284-1301, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37492152

RESUMO

How to identify the drivers of population connectivity remains a fundamental question in ecology and evolution. Answering this question can be challenging in aquatic environments where dynamic lake and ocean currents coupled with high levels of dispersal and gene flow can decrease the utility of modern population genetic tools. To address this challenge, we used RAD-Seq to genotype 959 yellow perch (Perca flavescens), a species with an ~40-day pelagic larval duration (PLD), collected from 20 sites circumscribing Lake Michigan. We also developed a novel, integrative approach that couples detailed biophysical models with eco-genetic agent-based models to generate "predictive" values of genetic differentiation. By comparing predictive and empirical values of genetic differentiation, we estimated the relative contributions for known drivers of population connectivity (e.g., currents, behavior, PLD). For the main basin populations (i.e., the largest contiguous portion of the lake), we found that high gene flow led to low overall levels of genetic differentiation among populations (F ST = 0.003). By far the best predictors of genetic differentiation were connectivity matrices that were derived from periods of time when there were strong and highly dispersive currents. Thus, these highly dispersive currents are driving the patterns of population connectivity in the main basin. We also found that populations from the northern and southern main basin are slightly divergent from one another, while those from Green Bay and the main basin are highly divergent (F ST = 0.11). By integrating biophysical and eco-genetic models with genome-wide data, we illustrate that the drivers of population connectivity can be identified in high gene flow systems.

2.
Pediatr Infect Dis J ; 42(8): 654-659, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37200514

RESUMO

BACKGROUND: Laryngeal coccidioidomycosis is a rare but life-threatening manifestation of coccidioidomycosis. Data in children are sparse and limited to case reports. We conducted this study to review the characteristics of laryngeal coccidioidomycosis in children. METHODS: We performed a retrospective review of patients ≤21 years of age with laryngeal coccidioidomycosis who were treated from January 2010 to December 2017. We collected demographic data, clinical and laboratory studies and patient outcomes. RESULTS: Five cases of pediatric laryngeal coccidioidomycosis were reviewed. All children were Hispanic and 3 were female. The median age was 1.8 years and the median duration of symptoms before diagnosis was 24 days. The most common symptoms included fever (100%), stridor (60%), cough (100%) and vocal changes (40%). Airway obstruction requiring tracheostomy and/or intubation for airway management was present in 80%. The most frequent location of lesions was the subglottic area. Coccidioidomycosis complement fixation titers were frequently low and culture/histopathology of laryngeal tissue was necessary to make a definitive diagnosis. All patients required surgical debridement and were treated with antifungal agents. None of the patients had recurrence during the follow-up period. CONCLUSIONS: This study suggests that laryngeal coccidioidomycosis in children presents with refractory stridor or dysphonia and severe airway obstruction. Favorable outcomes can be achieved with a comprehensive diagnostic work-up and aggressive surgical and medical management. With the rise in cases of coccidioidomycosis, physicians should have a heightened awareness regarding the possibility of laryngeal coccidioidomycosis when encountering children who have visited or reside in endemic areas with stridor or dysphonia.


Assuntos
Obstrução das Vias Respiratórias , Coccidioidomicose , Disfonia , Criança , Feminino , Humanos , Lactente , Masculino , Obstrução das Vias Respiratórias/tratamento farmacológico , Obstrução das Vias Respiratórias/etiologia , Antifúngicos/uso terapêutico , Coccidioidomicose/diagnóstico , Coccidioidomicose/tratamento farmacológico , Coccidioidomicose/epidemiologia , Disfonia/complicações , Disfonia/tratamento farmacológico , Sons Respiratórios , Estudos Retrospectivos
3.
Harmful Algae ; 108: 102102, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34588123

RESUMO

Microcystis is the predominant genus of harmful cyanobacterium in both Lake Erie and Saginaw Bay of Lake Huron and has the capacity to regulate the buoyancy of its colonies, sinking under certain conditions while floating towards the surface in others. Understanding the factors that control buoyancy is critical for interpretation of remote sensing data, modeling and forecasting harmful algal blooms within these two systems. To determine if Microcystis colony buoyancy in the two lakes responds similarly to diurnal light cycles, colony buoyant velocity (floating/sinking terminal velocity in a quiescent water column) and size were measured after manipulating the intensity of sunlight. Overall, there were more positively buoyant (floating) colonies in Lake Erie while most of the colonies in Saginaw Bay were negatively buoyant (sinking). In Lake Erie the colonies became less buoyant at increased light intensities and were less buoyant in the afternoon than in the morning. In both lakes, apparent colony density was more variable among small colonies (< 200 µm), whereas larger colonies showed a diminished response of density to light intensity and duration. These findings suggest that colony density becomes less plastic as colonies increase in size, leading to a weak relationship between size and velocity. These relationships may ultimately affect how the bloom is transported throughout each system and will help explain observed differences in vertical distribution and movement of Microcystis in the two lakes.


Assuntos
Cianobactérias , Microcystis , Baías , Proliferação Nociva de Algas , Lagos
4.
Arthritis Rheumatol ; 72(2): 242-250, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31449733

RESUMO

OBJECTIVE: Autoantibodies against citrullinated proteins are found in 64-89% of rheumatoid arthritis (RA) patients, with 88-99% specificity. This study was undertaken to create an unbiased, comprehensive profile of serum antibodies against the human proteome, including the citrullinome and the homocitrullinome, in RA patients, using a high-density peptide array. METHODS: Our high-density peptide array, consisting of >4.6 million peptides, contained the entire annotated human proteome. The 20,246 proteins were represented as overlapping 16-mer peptides. In addition to native peptides, citrullinated and homocitrullinated peptides were included, as substitutions for arginine and lysine, and provided a comprehensive screen against all possible epitopes. Twenty-six serum samples (from 8 controls and 18 RA patients) were profiled on the high-density peptide array. Using RA-specific epitopes, we constructed an 8-epitope diagnostic biomarker on a Gyrolab xPlore instrument with a cohort of 92 serum samples (from 29 controls and 63 RA patients). The diagnostic biomarker was further validated with an independent cohort of 181 serum samples (from 54 controls and 127 RA patients). RESULTS: In the initial cohort the diagnostic performance of the 8-epitope biomarker yielded 96.6% specificity and 92.1% sensitivity. The overall diagnostic performance in the validation cohort was 94.4% specificity and 85% sensitivity. In both cohorts, the performance of the 8-epitope diagnostic biomarker compared favorably against the Abnova cyclic citrullinated peptide 2 (CCP2) assay. Using data from the peptide array, we identified novel RA-specific epitopes and formed the basis of a new RA diagnostic assay. CONCLUSION: Comprehensive antibody profiling using a high-density peptide array not only identified novel RA-specific epitopes but also allowed us to construct a novel diagnostic biomarker that is as specific as and more sensitive than the Abnova CCP2 assay.


Assuntos
Anticorpos Antiproteína Citrulinada/sangue , Artrite Reumatoide/sangue , Artrite Reumatoide/imunologia , Autoanticorpos/sangue , Epitopos/sangue , Estudos de Coortes , Humanos
5.
Elife ; 82019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30618375

RESUMO

Perception of seasonal cues is critical for reproductive success in many plants. Exposure to winter cold is a cue that can confer competence to flower in the spring via a process known as vernalization. In certain grasses, exposure to short days is another winter cue that can lead to a vernalized state. In Brachypodium distachyon, we find that natural variation for the ability of short days to confer competence to flower is due to allelic variation of the FLOWERING LOCUS T (FT1) paralog FT-like9 (FTL9). An active FTL9 allele is required for the acquisition of floral competence, demonstrating a novel role for a member of the FT family of genes. Loss of the short-day vernalization response appears to have arisen once in B. distachyon and spread through diverse lineages indicating that this loss has adaptive value, perhaps by delaying spring flowering until the danger of cold damage to flowers has subsided.


Assuntos
Brachypodium/metabolismo , Brachypodium/fisiologia , Florígeno/metabolismo , Flores/fisiologia , Fotoperíodo , Homologia de Sequência de Aminoácidos , Brachypodium/genética , Mapeamento Cromossômico , Ritmo Circadiano/genética , Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Genes de Plantas
6.
J Environ Manage ; 227: 248-255, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30199720

RESUMO

Harmful algal blooms (HABs) pose public health risks worldwide, because of the toxins that they can produce. Researchers have explored the impact of HABs on local economies, but know relatively little about the decision-making that informs these behaviors that lead to financial losses. Understanding the factors that inform this decision-making is critical to developing mitigative solutions. This study seeks to understand how HABs in Western Lake Erie affect angler decision-making, before evaluating a possible decision-support tool-a harmful algal bloom forecast known as the Experimental Lake Erie HAB Tracker. The HAB Tracker provides a nowcast and five-day forecast of the spatial distribution and transport of Microcystis, the predominant species of harmful algae in Western Lake Erie. Data collected using focus groups and surveys were coded to identify key themes that influence angler decision-making. The theory of the diffusion of innovations provides an analytical framework to evaluate the potential for widespread adoption of the HAB forecast among Lake Erie anglers. Analysis of emerging themes revealed that Lake Erie anglers face three key decision-points when fishing in HABs: whether to fish, where to fish, and whether to eat the fish. Five primary variables factored into angler decisions on where and whether to fish including 1) perceptions of HAB aesthetics, 2) perceptions of the impact of HABs on angler health, 3) perceptions of the impact of HABs on fish, 4) communication methods, 5) perceptions of HABs by customers of charter captains. Most participants in this study sought to avoid fishing in HABs primarily for aesthetic reasons. Recreational anglers are more likely than charter captains to adopt the HAB Tracker as a decision-support tool, because it is compatible with their information needs and provides a relative advantage over existing sources of information. Charter captains are less likely to adopt the HAB Tracker, because they rely on their existing knowledge and social network for HAB information. If researchers can reduce the complexity of forecast information while increasing its accessibility and reliability, then all anglers will be more likely to adopt a HAB forecast as a decision-support tool while fishing in Lake Erie during bloom season.


Assuntos
Proliferação Nociva de Algas , Modelos Teóricos , Saúde Pública , Animais , Previsões , Humanos , Lagos , Reprodutibilidade dos Testes , Estações do Ano
7.
Breast Cancer (Auckl) ; 12: 1178223418771909, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29881287

RESUMO

Most of the patients undergoing treatment for cancer require placement of a totally implantable venous access device to facilitate safe delivery of chemotherapy. However, implantable ports also increase the risk of deep vein thrombosis and related complications in this high-risk population. The objective of this study was to assess the incidence of upper-extremity deep vein thrombosis (UEDVT) in patients with breast cancer to determine whether the risk of UEDVT was higher with chest versus arm ports, as well as to determine the importance of previously reported risk factors predisposing to UEDVT in the setting of active cancer. We retrospectively reviewed the medical records of 297 women with breast cancer who had ports placed in our institution between the dates of December 1, 2010, and December 31, 2016. The primary outcome was the development of radiologically confirmed UEDVT ipsilateral to the implanted port. Overall, 17 of 297 study subjects (5.7%) were found to have UEDVT. There was 1 documented case of associated pulmonary embolism. Fourteen (9.5%) of 147 subjects with arm ports experienced UEDVT compared with only 3 (2.0%) of 150 subjects with chest ports (P = .0056). Thus, implantation of arm ports as opposed to chest ports may be associated with a higher rate of UEDVT in patients with breast cancer.

8.
Environ Sci Technol ; 51(12): 6745-6755, 2017 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-28535339

RESUMO

Annual cyanobacterial blooms dominated by Microcystis have occurred in western Lake Erie (U.S./Canada) during summer months since 1995. The production of toxins by bloom-forming cyanobacteria can lead to drinking water crises, such as the one experienced by the city of Toledo in August of 2014, when the city was rendered without drinking water for >2 days. It is important to understand the conditions and environmental cues that were driving this specific bloom to provide a scientific framework for management of future bloom events. To this end, samples were collected and metatranscriptomes generated coincident with the collection of environmental metrics for eight sites located in the western basin of Lake Erie, including a station proximal to the water intake for the city of Toledo. These data were used to generate a basin-wide ecophysiological fingerprint of Lake Erie Microcystis populations in August 2014 for comparison to previous bloom communities. Our observations and analyses indicate that, at the time of sample collection, Microcystis populations were under dual nitrogen (N) and phosphorus (P) stress, as genes involved in scavenging of these nutrients were being actively transcribed. Targeted analysis of urea transport and hydrolysis suggests a potentially important role for exogenous urea as a nitrogen source during the 2014 event. Finally, simulation data suggest a wind event caused microcystin-rich water from Maumee Bay to be transported east along the southern shoreline past the Toledo water intake. Coupled with a significant cyanophage infection, these results reveal that a combination of biological and environmental factors led to the disruption of the Toledo water supply. This scenario was not atypical of reoccurring Lake Erie blooms and thus may reoccur in the future.


Assuntos
Microcystis , Abastecimento de Água , Canadá , Cianobactérias , Eutrofização , Lagos
9.
J Affect Disord ; 192: 104-8, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26717522

RESUMO

BACKGROUND: Three symptoms of (hypo)mania that clinically represent mood disorders mixed states have been omitted from the DSM-5 mixed features specifier because 'they fail to discriminate between manic and depressive syndromes'. Therefore, the present study examined the role of distractibility, irritability and psychomotor agitation (DIP) in characterising mixed depressive states. METHODS: Fifty in-patients at a specialist mood disorders unit underwent a detailed longitudinal clinical evaluation (3-6 weeks) and were assessed on a range of standardized measures to characterise their illness according to depression subtype, duration of illness and clinical features-including specifically depressive and manic symptoms and the context in which these occur. RESULTS: 49 patients met criteria for major depressive episode, and of these, 34 experienced at least one dip symptom. Patients who endorsed distractibility were more likely to be diagnosed with Bipolar Disorder than Major Depressive Disorder; patients who endorsed irritable mood were more likely to have non-melancholic depression (admixture of depressive and anxiety symptoms), and patients who reported psychomotor agitation experienced a significantly greater number of distinct periods of (hypo)manic symptoms compared with those who did not. LIMITATIONS: The present study used a modest sample size and did not control for medication or comorbid illness. Although this is inevitable when examining real-world patients in a naturalistic setting, future research needs to allow for comorbidity and its impact, specifically anxiety. CONCLUSIONS: The present findings suggest that all 3 symptoms that have been excluded from DSM-5 may be cardinal features of mixed states, as they 'dip' into depressive symptoms to create a mixed state.


Assuntos
Transtorno Ciclotímico/diagnóstico , Depressão/diagnóstico , Humor Irritável , Transtornos do Humor/diagnóstico , Adulto , Ansiedade/diagnóstico , Comorbidade , Transtorno Ciclotímico/complicações , Depressão/complicações , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Transtornos do Humor/complicações
11.
Arch Otolaryngol Head Neck Surg ; 138(7): 680-2, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22801893

RESUMO

Disk (or button) battery ingestion is not uncommon, with an estimated US incidence of 2 to 8 per million annually.(1) Reported serious adverse sequelae include esophageal stenosis, tracheoesophageal fistula, vocal cord paralysis, massive bleeding, and death.(1,2) There are, however, surprisingly few reports of aspirated batteries in the searchable literature; we found only 2. We present the diagnostic workup and treatment of a previously healthy 4-year-old boy with an aspirated disk battery in the bronchus.


Assuntos
Brônquios , Fontes de Energia Elétrica , Corpos Estranhos/diagnóstico por imagem , Corpos Estranhos/cirurgia , Broncoscopia , Cateterismo , Pré-Escolar , Diagnóstico Diferencial , Humanos , Masculino , Radiografia Torácica
12.
Arch Otolaryngol Head Neck Surg ; 138(2): 119-21, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22248562

RESUMO

OBJECTIVE: To determine the efficacy of various cleaning and disinfective methods in reducing bacterial and fungal load on flexible fiberoptic laryngoscopes (FFLs). DESIGN: In vitro model. SUBJECTS: Flexible fiberoptic laryngoscopes contaminated with Staphylococcus aureus and Candida albicans. INTERVENTIONS: Contamination with S aureus and C albicans was separately induced on FFLs, which were then disinfected with different protocols: 20-, 15-, 10-, and 5-minute soaks in ortho-phthalaldehyde (Cidex OPA; Johnson & Johnson) with or without presoaking in an enzymatic soap solution for 5 minutes; an isolated 5-minute soak in an enzymatic soap solution; a 30-second wipe with antibacterial soap and water; a 30-second wipe with isopropyl alcohol; a 30-second wipe with antibacterial soap, followed by a 30-second scrub with isopropyl alcohol; and a 30-second wipe with germicidal cloth, all accompanied by previous rinsing with 30 seconds of running tap water. RESULTS: All protocols except the isolated 5-minute soak in enzymatic soap solution were successful in completely disinfecting the FFLs after experimental contamination with S aureus or C albicans. CONCLUSION: Various different cleaning methods appeared to properly disinfect FFLs after inoculation with S aureus and C albicans in an in vitro model.


Assuntos
2-Propanol/farmacologia , Desinfecção/métodos , Contaminação de Equipamentos/prevenção & controle , Glutaral/farmacologia , Laringoscópios/microbiologia , Sabões/farmacologia , Candida albicans , Tecnologia de Fibra Óptica , Humanos , Doença Iatrogênica/prevenção & controle , Staphylococcus aureus
13.
J Forensic Sci ; 57(2): 509-14, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22103855

RESUMO

Three relatively new reagents for developing latent fingermarks on porous substrates, 1,2-indandione (IND), 5-methylthioninhydrin (5-MTN), and lawsone, are compared with the more widely used ninhydrin and 1,8-diazofluoren (DFO). Developed latent fingermark visualization on 10 different substrates comprising colored papers, cardboard, and cellophane rather than conventional printer and writing/notepad paper is assessed using latent fingermark deposits from 48 donors. Results show improved fluorescent fingermark visualization using IND compared with DFO on a range of colored cardboards and thick white paper, thus extending the range of substrates known to yield improved visualization with IND. Adding zinc chloride to IND failed to yield any further improvement in fluorescent fingermark visualization. 5-MTN (with and without zinc chloride posttreatment) showed no improvement in visualization compared with ninhydrin and DFO although visible fingermarks were developed. Lawsone produced fluorescent visible fingermarks only with white substrates, which were inferior to those produced with DFO.


Assuntos
Compostos Aza/química , Dermatoglifia , Ninidrina/análogos & derivados , Adolescente , Adulto , Feminino , Humanos , Indanos/química , Indicadores e Reagentes , Masculino , Pessoa de Meia-Idade , Naftoquinonas/química , Porosidade , Propriedades de Superfície , Adulto Jovem
14.
Med J Aust ; 194(11): S92-6, 2011 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-21644862

RESUMO

The 1998 Ministerial Review of General Practice Training identified several areas for improvement that led to major changes in the provision of general practice training, including the establishment of General Practice Education and Training (GPET) and the regionalisation of training. The regionalised training business model has been in place for nearly 10 years, and several key organisations have been involved in its evolution, including the Australian Government, speciality colleges, GPET and regionalised training providers. Both the college-focused and regionalised-focused models have had some successes. These include recognition and support of general practice as a vocational specialty, increased numbers of junior doctors undertaking placements in general practice, and increased numbers of registrars training in rural areas. This period has also seen changes in the governance and decision-making processes with creation of a new framework that is inclusive of all the key players in the new regionalised training system. The future holds challenges for the regionalised training business model as the general practice education and training landscape becomes more complex. The framework in the current model will provide a base to help meet these challenges and allow for further sustainable expansion.


Assuntos
Governança Clínica , Medicina Geral/educação , Modelos Educacionais , Austrália , Humanos
15.
J Neurosurg Pediatr ; 7(2): 157-60, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21284461

RESUMO

Cerebellopontine angle arachnoid cysts are usually asymptomatic, but are frequently found incidentally because of increased use of neuroimaging. Nevertheless, as these cysts enlarge, they may compress surrounding structures and cause neurological symptoms. Patients may present with vague, nonspecific symptoms such as headache, nausea, vomiting, and vertigo. Cranial nerve palsies, including sensorineural hearing loss and facial weakness, although rare, have also been reported in association with posterior fossa arachnoid cysts. Although surgery for these entities is controversial, arachnoid cysts can be treated surgically with open craniotomy for cyst removal, fenestration into adjacent arachnoid spaces, shunting of cyst contents, or endoscopic fenestration. Reversal of sensorineural hearing loss following open craniotomy treatment has been described in the literature in only 1 adult and 1 pediatric case. Improvement in facial weakness has also been reported after open craniotomy and arachnoid cyst fenestration. The authors report the first case of complete recovery from sensorineural hearing loss and facial weakness following endoscopic fenestration in a patient with a cerebellopontine angle arachnoid cyst.


Assuntos
Cistos Aracnóideos/cirurgia , Ângulo Cerebelopontino , Endoscopia , Doenças do Nervo Facial/cirurgia , Perda Auditiva Neurossensorial/cirurgia , Cistos Aracnóideos/complicações , Criança , Doenças do Nervo Facial/etiologia , Perda Auditiva Neurossensorial/etiologia , Humanos , Masculino , Procedimentos Neurocirúrgicos/métodos
16.
Australas Psychiatry ; 18(5): 413-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20863179

RESUMO

OBJECTIVE: The aim of this paper is to evaluate the accuracy of a new genotyping test (Antidepressant PredictAR) in assigning patients as likely 'poor', 'rapid' or 'normal' metabolizers of antidepressant drugs. METHOD: Eighty-nine patients were clinically assigned (on the basis of their historical response to antidepressant drugs) as 'poor', 'rapid' or 'normal' metabolizers and comparison was then made to their test-based 2D6 and C19 genotyping status reports. RESULTS: The overall capacity of the test to allocate patients to four differing phenotypic categories reporting for the genotyping test was not significant in relation to either C19 or 2D6 analyses. However, the C19 test did appear to have some capacity to identify rapid metabolizers, and we note how we then sought to manage such patients clinically. CONCLUSIONS: The test may have some capacity to identify patients with a rapid metabolizing profile. Any further advantages were not identified by this study, whether reflecting methodological and/or assay limitations.


Assuntos
Antidepressivos/farmacocinética , Antidepressivos/uso terapêutico , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/genética , Adolescente , Adulto , Idoso , Hidrocarboneto de Aril Hidroxilases/genética , Citocromo P-450 CYP2C19 , Citocromo P-450 CYP2D6/genética , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Valor Preditivo dos Testes , Adulto Jovem
17.
Environ Sci Technol ; 44(6): 2098-104, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20148550

RESUMO

A high flow rate (300 L min(-1)) multicapillary denuder was designed to collect trace atmospheric semivolatile organic compounds (SOCs). The denuder is coated with a reusable, polydimethylsiloxane stationary phase as a nonselective absorbent for SOCs. A solvent-free thermal desorption method was developed, including sample cleanup, that is selective for nonpolar SOCs, and has low consumables cost per sample. The entire sample is transferred into the gas chromatograph to minimize the sampling time required to collect detectable analyte mass. Trace concentrations (0.1-100 pg m(-3)) of polychlorinated biphenyls and hexachlorobenzene were measured in the atmosphere near Lake Superior in sample times of 3.2-6.2 h. Overall method precision was determined using field duplicates and compared to the conventional high-volume sampler method. Method precision (coefficient of variation) of 16% was found for the high-flow denuder compared to 21% for the high-volume method. The relative difference between the two methods was 25%, with the high-flow denuder method giving generally lower concentrations. The high-flow denuder is an alternative to high-volume or passive samplers when it is desirable to separate gaseous from particle-associated SOCs upstream of a filter. The method is advantageous for studies that require high temporal resolution.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Compostos Orgânicos Voláteis/análise , Poluentes Atmosféricos/química , Atmosfera/química , Monitoramento Ambiental/instrumentação , Hexaclorobenzeno/análise , Hexaclorobenzeno/química , Bifenilos Policlorados/análise , Bifenilos Policlorados/química , Compostos Orgânicos Voláteis/química
18.
Aust Fam Physician ; 39(11): 869-74, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21301663

RESUMO

Regional training providers face many challenges in delivering vocational training to general practice registrars across Australia. They need to be able to respond to new learning theories and the ever expanding volume of medical knowledge, as well as the changing medical workforce. In 2008, the Victorian Metropolitan Alliance (VMA) embarked on a project to map the new Royal Australian College of General Practitioners curriculum to the VMA program. The aim of this article is to describe the processes through which the VMA created a curriculum guide for peer learning workshops, supervisors and registrars, designed to be adaptable to various Australian curricula and to be flexible and robust, as well as accessible to the intended users.


Assuntos
Currículo , Educação de Pós-Graduação em Medicina/métodos , Educação Vocacional/métodos , Austrália , Educação , Humanos , Modelos Educacionais , Grupo Associado , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Vitória
19.
J Chromatogr A ; 1217(3): 256-63, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19959174

RESUMO

A modeling approach is presented to predict the sorptive sampling collection efficiency of gaseous semivolatile organic compounds (SOCs) and the artifact caused by collection of particle-associated SOCs in multicapillary diffusion denuders containing polydimethylsiloxane (PDMS) stationary phase. Approaches are presented to estimate the equilibrium PDMS-gas partition coefficient (K(pdms)) from a solvation parameter model for any compound, and, for nonpolar compounds, from the octanol-air partition coefficient (K(oa)) if measured K(pdms) values are not available. These estimated K(pdms) values are compared with K(pdms) measured by gas chromatography. Breakthrough fraction was measured for SOCs collected from ambient air using high-flow (300 L min(-1)) and low-flow (13 L min(-1)) denuders under a range of sampling conditions (-10 to 25 degrees C; 11-100% relative humidity). Measured breakthrough fraction agreed with predictions based on frontal chromatography theory using K(pdms) and equations of Golay, Lövkvist and Jönsson within measurement precision. Analytes included hexachlorobenzene, 144 polychlorinated biphenyl congeners, and polybrominated diphenyl ethers 47 and 99. Atmospheric particle transmission efficiency was measured for the high-flow denuder (0.037-6.3 microm diameter), and low-flow denuder (0.015-3.1 microm diameter). Particle transmission predicted using equations of Gormley and Kennedy, Pich, and a modified filter model, agreed within measurement precision (high-flow denuder) or were slightly greater than (low-flow denuder) measured particle transmission. As an example application of the model, breakthrough volume and particle collection artifact for the two denuder designs were predicted as a function of K(oa) for nonpolar SOCs. The modeling approach is a necessary tool for the design and use of denuders for sorptive sampling with PDMS stationary phase.


Assuntos
Cromatografia Gasosa/instrumentação , Cromatografia Gasosa/métodos , Gases/química , Modelos Químicos , Compostos Orgânicos Voláteis/química , Algoritmos , Artefatos , Dimetilpolisiloxanos/química , Distribuição de Poisson , Análise de Regressão
20.
J Chromatogr A ; 1216(32): 5940-8, 2009 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-19570539

RESUMO

A novel gas-phase cleanup method was developed for use with a thermal desorption method for analysis of trace semivolatile organic compounds (SOCs) in the atmosphere using diffusion denuder samplers to separate gas-phase from particle-associated fractions. The cleanup selectively removed hydrogen-bonding chemicals from samples, including much of the background matrix of oxidized organic compounds that is present in ambient air samples. Abraham solvation parameters were found to be useful predictors of recovery of compounds through the cleanup method; most compounds with A+B<0.3 and L

Assuntos
Poluentes Atmosféricos/análise , Cromatografia Gasosa/métodos , Monitoramento Ambiental/métodos , Compostos Orgânicos Voláteis/análise , Éteres Difenil Halogenados/análise , Bifenilos Policlorados/análise , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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