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1.
Philos Trans A Math Phys Eng Sci ; 382(2270): 20230155, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38403058

RESUMEN

This paper investigates the potential for reducing the complexity of AI and Law and empirical legal studies projects through a novel annotation methodology that relies on GPT Family Models to assist human annotators. Improving the speed, cost and quality of annotation could greatly benefit such projects. In modelling types of legal claims, researchers in the fields of empirical legal studies and AI and Law have long relied on manually annotating factors in case texts. To demonstrate our methodology, we employ cases and factors regarding whether a police officer has constitutional authority to detain a motorist on the basis of the officer's suspicion that the motorist is trafficking drugs. Our results demonstrate how recent advances in text analytics can reduce the burden of identifying factors in large numbers of cases and improve machine learning models' predictions of case outcomes. This article is part of the theme issue 'A complexity science approach to law and governance'.

3.
J Occup Environ Hyg ; 16(9): 634-642, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31298629

RESUMEN

An ideal inhalable aerosol sampler for occupational exposure monitoring would have a sampling efficiency that perfectly matches the inhalable particulate matter (IPM) criterion. Two common aerosol samplers in use worldwide are the closed-face cassette (CFC) and the Institute of Occupational Medicine (IOM) sampler. However, the CFC is known to under-sample, with near zero sampling efficiency for particles >30 µm, whereas the IOM, considered by many to be the "gold standard" in inhalable samplers, has been shown to over-sample particles >60 µm. A new sampler in development incorporates characteristics of both the CFC and the IOM. Like the CFC, it would be disposable, have a simple design, and is intended to be oriented at a 45° downward angle. Like the IOM, the new sampler has a 15-mm inlet diameter and incorporates a 25-mm filter cassette with a protruding lip. The IOM is oriented at 0° to the horizontal, so it is hypothesized that orienting the new sampler at ∼45° downward angle will reduce oversampling of larger particles. In comparison, the CFC's inlet diameter is 4 mm; increasing the size of the inlet should allow the new sampler to have an increased efficiency relative to the CFC for all particles. A unique characteristic of the new sampler is the incorporation of a one-piece capsule-style filter that mimics the IOM's cassette but is made of disposable material. Seven different sizes of alumina particles (mean aerodynamic diameters from 4.9-62.4 µm) were tested (total = 124 samples collected). For each test, six samplers were placed on a manikin located inside a wind tunnel operated at 0.2 m/sec. Results indicated that the new sampler improved on the CFC for smaller particles, providing a larger range for which it matches the IPM criterion, up to 44.3 µm. However, the efficiency was significantly lower in comparison to the IPM criterion for particle sizes above 60 µm. Overall, the new sampler showed promise, but additional modifications may help improve sampling efficiency for larger particles.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Equipos Desechables , Monitoreo del Ambiente/instrumentación , Exposición por Inhalación/análisis , Exposición Profesional/análisis , Aerosoles , Diseño de Equipo , Humanos , Tamaño de la Partícula , Material Particulado/análisis
4.
Anal Chem ; 90(10): 6229-6239, 2018 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-29659249

RESUMEN

A Raman spectroscopy based method has been developed for measurement of trace airborne concentrations of respirable crystalline silica (RCS) using various aerosol sampling and analysis techniques. Three aerosol microconcentration techniques were investigated for effective coupling of collected particulate samples with micro-Raman spectroscopy: (i) direct analysis on a particulate filter after focused aerosol collection using a converging nozzle; (ii) analysis of dried particulate deposit on a filter obtained directly from the aerosol phase using the Spotsampler device; and (iii) analysis of a dried spot (∼1-3 mm diameter) obtained by redepositing the particulate sample, after low-temperature plasma ashing of the filter sample. The deposition characteristics (i.e., spot diameter, shape, and deposit uniformity) of each technique were investigated. Calibration curves were constructed and detection limits were estimated for α-quartz using the A1 Raman Si-O-Si stretching-bending phonon mode at 465 cm-1. The measurement sensitivity could be substantially improved by increasing the signal integration time and by reducing the particle deposition area. Detection limits in the range of 8-55 ng could be achieved by microconcentrating the aerosol sample over a spot measuring 400-1000 µm in diameter. These detection limits were two to three orders of magnitude lower compared to those attainable using current standardized X-ray diffraction and infrared spectroscopy methods. The low detection limits suggest that near real-time measurements of RCS could be achieved with limits of quantification ranging from 2 to 18.5 µg/m3 (at 10 min collection time and 1.2 L/min sampling flow rate), depending on microconcentration technique used. The method was successfully extended to the measurement of α-quartz air concentration in representative workplace aerosol samples. This study demonstrates the potential of portable micro-Raman spectroscopy for near-real time measurement of trace RCS in air.


Asunto(s)
Dióxido de Silicio/análisis , Dióxido de Silicio/química , Aerosoles , Cristalización , Tamaño de la Partícula , Espectrometría Raman , Propiedades de Superficie , Factores de Tiempo
5.
J Occup Environ Hyg ; 13(1): 40-7, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26308974

RESUMEN

An interlaboratory study was carried out to evaluate the use of acid-soluble cellulosic air sampling capsules for their suitability in the measurement of trace elements in workplace atmospheric samples. These capsules are used as inserts to perform closed-face cassette sample collection for occupational exposure monitoring. The interlaboratory study was performed in accordance with NIOSH guidelines that describe statistical procedures for evaluating measurement accuracy of air monitoring methods. The performance evaluation materials used consisted of cellulose acetate capsules melded to mixed-cellulose ester filters that were dosed with multiple elements from commercial standard aqueous solutions. The cellulosic capsules were spiked with the following 33 elements of interest in workplace air monitoring: Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, In, K, La, Li, Mg, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Sr, Te, Ti, Tl, V, W, Y, Zn, Zr. The elemental loading levels were certified by an accredited provider of certified reference materials. Triplicates of media blanks and multielement-spiked capsules at three different elemental loadings were sent to each participating laboratory; the elemental loading levels were not revealed to the laboratories. The volunteer participating laboratories were asked to prepare the samples by acid dissolution and to analyze aliquots of extracted samples by inductively coupled plasma atomic emission spectrometry in accordance with NIOSH methods. It was requested that the study participants report their analytical results in units of µg of each target element per internal capsule sample. For the majority of the elements investigated (30 out of 33), the study accuracy estimates obtained satisfied the NIOSH accuracy criterion (A < 25%). This investigation demonstrates the utility of acid-soluble internal sampling capsules for multielement analysis by atomic spectrometry.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Laboratorios , Exposición Profesional/análisis , Oligoelementos/análisis , Celulosa/análogos & derivados , Celulosa/química , Monitoreo del Ambiente/métodos , Filtración/instrumentación , Espectrofotometría Atómica/métodos
6.
Sci Eng Ethics ; 21(3): 789-807, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25820149

RESUMEN

Assessment in ethics education faces a challenge. From the perspectives of teachers, students, and third-party evaluators like the Accreditation Board for Engineering and Technology and the National Institutes of Health, assessment of student performance is essential. Because of the complexity of ethical case analysis, however, it is difficult to formulate assessment criteria, and to recognize when students fulfill them. Improvement in students' moral reasoning skills can serve as the focus of assessment. In previous work, Rosa Lynn Pinkus and Claire Gloeckner developed a novel instrument for assessing moral reasoning skills in bioengineering ethics. In this paper, we compare that approach to existing assessment techniques, and evaluate its validity and reliability. We find that it is sensitive to knowledge gain and that independent coders agree on how to apply it.


Asunto(s)
Bioingeniería/ética , Evaluación Educacional/normas , Ética Profesional/educación , Encuestas y Cuestionarios/normas , Bioingeniería/educación , Humanos , Reproducibilidad de los Resultados
7.
J Occup Environ Hyg ; 12(11): 774-84, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26011602

RESUMEN

The National Institute for Occupational Safety and Health has conducted an occupational exposure assessment study of manganese (Mn) in welding fume of construction workers rebuilding tanks, piping, and process equipment at two oil refineries. The objective of this study was to evaluate exposures to different Mn fractions using a sequential extraction procedure. Seventy-two worker-days were monitored for either total or respirable Mn during stick welding and associated activities both within and outside of confined spaces. The samples were analyzed using an experimental method to separate different Mn fractions by valence states based on selective chemical solubility. The full-shift total particulate Mn time-weighted average (TWA) breathing zone concentrations ranged from 0.013-29 for soluble Mn in a mild ammonium acetate solution; from 0.26-250 for Mn(0,2+) in acetic acid; from non-detectable (ND) - 350 for Mn(3+,4+) in hydroxylamine-hydrochloride; and from ND - 39 micrograms per cubic meter (µg/m(3)) for insoluble Mn fractions in hydrochloric and nitric acid. The summation of all Mn fractions in total particulate TWA ranged from 0.52-470 µg/m(3). The range of respirable particulate Mn TWA concentrations were from 0.20-28 for soluble Mn; from 1.4-270 for Mn(0,2+); from 0.49-150 for Mn(3+,4+); from ND - 100 for insoluble Mn; and from 2.0-490 µg/m(3) for Mn (sum of fractions). For all jobs combined, total particulate TWA GM concentrations of the Mn(sum) were 99 (GSD = 3.35) and 8.7 (GSD = 3.54) µg/m(3) for workers inside and outside of confined spaces; respirable Mn also showed much higher levels for welders within confined spaces. Regardless of particle size and confined space work status, Mn(0,2+) fraction was the most abundant followed by Mn(3+,4+) fraction, typically >50% and ∼30-40% of Mn(sum), respectively. Eighteen welders' exposures exceeded the ACGIH Threshold Limit Values for total Mn (100 µg/m(3)) and 25 exceeded the recently adopted respirable Mn TLV (20 µg/m(3)). This study shows that a welding fume exposure control and management program is warranted, especially for welding jobs in confined spaces.


Asunto(s)
Manganeso/análisis , Exposición Profesional/análisis , Material Particulado/análisis , Soldadura , Contaminantes Ocupacionales del Aire/análisis , Contaminantes Ocupacionales del Aire/química , Espacios Confinados , Industria de la Construcción , Exposición por Inhalación/análisis , Manganeso/química , National Institute for Occupational Safety and Health, U.S. , Industria del Petróleo y Gas , Tamaño de la Partícula , Material Particulado/química , Estados Unidos
8.
Gefahrst Reinhalt Luft ; 2015(1-2): 7-16, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26309348

RESUMEN

The NIOSH Manual of Analytical Methods (NMAM: www.cdc.gov/niosh/nmam) is a collection of methods for sampling and analysis of contaminants in workplace air (or surfaces) and in the blood and urine of workers who are occupationally exposed. NIOSH methods are used worldwide for occupational exposure assessment to chemical and biological agents. These methods have been developed or adapted by NIOSH and/or its partners and have been evaluated according to established experimental protocols and performance criteria. NMAM also includes associated chapters on quality assurance, sampling guidance, instrumentation, aerosol measurement, gas and vapor monitoring, portable monitoring devices, and so forth. Often NIOSH methods are developed in coordination with voluntary consensus standards organizations such as ASTM International, the Comité Européen de Normalisation (European Committee for Standardization, CEN) and the International Organization for Standardization (ISO). Efforts to harmonize NIOSH methods with relevant consensus standards procedures are of particular interest and are highlighted. NIOSH also has a formal Memorandum of Understanding (MOU) with the Institut für Arbeitsschutz der Deutschen Geseltzlichen Unfallversicherung (Institute for Occupational Safety and Health of the German Social Accident Insurances, IFA), whereby NIOSH is adopting selected IFA methods and vice-versa. An overview of recent research and technology transfer activities relating to NMAM methods is provided, with selected examples in applications to exposure science, notably workplace air monitoring. Included in the discussion are newly approved methods and those under development, as well as needs for new methods and updates. Of particular interest are recent NIOSH recommendations and associated research on air samplers used for sampling and analysis of airborne particles.

9.
Gefahrst Reinhalt Luft ; 74(10): 403-410, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26435581

RESUMEN

An evaluation was carried out to investigate the suitability of polyvinyl chloride (PVC) internal capsules, housed within air sampling devices, for gravimetric analysis of airborne particles collected in workplaces. Experiments were carried out using blank PVC capsules and PVC capsules spiked with 0,1 - 4 mg of National Institute of Standards and Technology Standard Reference Material® (NIST SRM) 1648 (Urban Particulate Matter) and Arizona Road Dust (Air Cleaner Test Dust). The capsules were housed within plastic closed-face cassette samplers (CFCs). A method detection limit (MDL) of 0,075 mg per sample was estimated. Precision Sr at 0,5 - 4 mg per sample was 0,031 and the estimated bias was 0,058. Weight stability over 28 days was verified for both blanks and spiked capsules. Independent laboratory testing on blanks and field samples verified long-term weight stability as well as sampling and analysis precision and bias estimates. An overall precision estimate Srt of 0,059 was obtained. An accuracy measure of ±15,5% was found for the gravimetric method using PVC internal capsules.

11.
J Occup Environ Hyg ; 10(6): 297-306, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23548078

RESUMEN

Airborne particles that are collected using closed-face filter cassettes (CFCs), which are used widely in the sampling of workplace aerosols, can deposit in places other than on the filter and thereby may not be included in the ensuing analysis. A technique for ensuring that internal non-filter deposits are included in the analysis is to collect airborne particles within an acid-soluble internal capsule that, following sampling, can be dissolved along with the filter for subsequent elemental analysis. An interlaboratory study (ILS) was carried out to evaluate the use of cellulosic CFC capsule inserts for their suitability in the determination of trace elements in airborne samples. The ILS was performed in accordance with an applicable ASTM International standard practice, ASTM E691, which describes statistical procedures for investigating interlaboratory precision. Performance evaluation materials consisted of prototype cellulose acetate capsules attached to mixed-cellulose ester filters. Batches of capsules were dosed with Pb-containing materials (standard aqueous solutions, and certified reference material soil and paint). Also, aerosol samples containing nine target analyte elements (As, Cd, Co, Cr, Cu, Fe, Pb, Mn, and Ni) were generated using a multiport sampler; various concentrations and sampling times were employed to yield samples fortified at desired loading levels. Triplicates of spiked capsules at three different loadings were conveyed to each volunteer laboratory; loading levels were unknown to the participants. The laboratories were asked to prepare the samples by acid dissolution and to analyze aliquots of extracted samples by atomic spectrometry in accordance with applicable ASTM International Standards. Participants were asked to report their results in units of µg of each target element per sample. For the elements investigated, inter-laboratory precision and recovery estimates from the participating laboratories demonstrated the utility of the cellulosic capsule inserts for the measurement of sampled trace elements.


Asunto(s)
Aerosoles/análisis , Contaminantes Ocupacionales del Aire/análisis , Monitoreo del Ambiente/instrumentación , Exposición Profesional/análisis , Celulosa/análogos & derivados , Celulosa/química , Monitoreo del Ambiente/métodos
12.
Front Artif Intell ; 6: 1279794, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38045764

RESUMEN

The emergence of ChatGPT has sensitized the general public, including the legal profession, to large language models' (LLMs) potential uses (e.g., document drafting, question answering, and summarization). Although recent studies have shown how well the technology performs in diverse semantic annotation tasks focused on legal texts, an influx of newer, more capable (GPT-4) or cost-effective (GPT-3.5-turbo) models requires another analysis. This paper addresses recent developments in the ability of LLMs to semantically annotate legal texts in zero-shot learning settings. Given the transition to mature generative AI systems, we examine the performance of GPT-4 and GPT-3.5-turbo(-16k), comparing it to the previous generation of GPT models, on three legal text annotation tasks involving diverse documents such as adjudicatory opinions, contractual clauses, or statutory provisions. We also compare the models' performance and cost to better understand the trade-offs. We found that the GPT-4 model clearly outperforms the GPT-3.5 models on two of the three tasks. The cost-effective GPT-3.5-turbo matches the performance of the 20× more expensive text-davinci-003 model. While one can annotate multiple data points within a single prompt, the performance degrades as the size of the batch increases. This work provides valuable information relevant for many practical applications (e.g., in contract review) and research projects (e.g., in empirical legal studies). Legal scholars and practicing lawyers alike can leverage these findings to guide their decisions in integrating LLMs in a wide range of workflows involving semantic annotation of legal texts.

13.
JCPP Adv ; 3(1): e12140, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37033195

RESUMEN

Background: Reporting retention data is critical to determining the soundness of a study's conclusions (internal validity) and broader generalizability (external validity). Although selective attrition can lead to overestimates of effects, biased conclusions, or overly expansive generalizations, retention rates are not reported in many longitudinal studies. Methods: We examined multiple child- and family-level factors potentially associated with retention in a longitudinal study of younger siblings of children with autism spectrum disorder (ASD; n = 304) or typical development (n = 163). The sample was followed from the first year of life to 36 months of age, for up to 7 visits. Results: Of the 467 infant siblings who were consented and participated in at least one research visit, 397 (85.0%) were retained to study completion at 36 months. Retention rates did not differ by familial risk group (ASD-risk vs. Low-risk), sex, race, ethnicity, age at enrollment, number of children in the family, maternal employment, marital status, or parent concerns about the child at enrollment. A stepwise regression model identified 4 variables that, together, provided the most parsimonious predictive model of study retention: maternal education, maternal age at child's birth, travel distance to the study site, and diagnostic outcome classification at the final study visit. Conclusions: The retained and not-retained groups did not differ on most demographic and clinical variables, suggesting few threats to internal and external validity. The significantly higher rate of retention of children diagnosed with ASD (95%) than typically developing children (83%) may, however, present biases when studying recurrence risk. We conclude by describing engagement and tracking methods that can be used to maximize retention in longitudinal studies of children at risk of ASD.

14.
J Environ Monit ; 14(2): 360-7, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22038017

RESUMEN

Inductively coupled plasma mass spectrometry (ICP-MS) is becoming more widely used for trace elemental analysis in the occupational hygiene field, and consequently new ICP-MS international standard procedures have been promulgated by ASTM International and ISO. However, there is a dearth of interlaboratory performance data for this analytical methodology. In an effort to fill this data void, an interlaboratory evaluation of ICP-MS for determining trace elements in workplace air samples was conducted, towards fulfillment of method validation requirements for international voluntary consensus standard test methods. The study was performed in accordance with applicable statistical procedures for investigating interlaboratory precision. The evaluation was carried out using certified 37-mm diameter mixed-cellulose ester (MCE) filters that were fortified with 21 elements of concern in occupational hygiene. Elements were spiked at levels ranging from 0.025 to 10 µg filter(-1), with three different filter loadings denoted "Low", "Medium" and "High". Participating laboratories were recruited from a pool of over fifty invitees; ultimately twenty laboratories from Europe, North America and Asia submitted results. Triplicates of each certified filter with elemental contents at three different levels, plus media blanks spiked with reagent, were conveyed to each volunteer laboratory. Each participant was also provided a copy of the test method which each participant was asked to follow; spiking levels were unknown to the participants. The laboratories were requested to prepare the filters by one of three sample preparation procedures, i.e., hotplate digestion, microwave digestion or hot block extraction, which were described in the test method. Participants were then asked to analyze aliquots of the prepared samples by ICP-MS, and to report their data in units of µg filter(-1). Most interlaboratory precision estimates were acceptable for medium- and high-level spikes (RSD <25%), but generally yielded greater uncertainties than were anticipated at the outset of the study.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Contaminación del Aire Interior/análisis , Monitoreo del Ambiente/métodos , Laboratorios , Oligoelementos/análisis , Contaminación del Aire Interior/estadística & datos numéricos , Monitoreo del Ambiente/instrumentación , Filtración/instrumentación , Humanos , Exposición por Inhalación/análisis , Exposición por Inhalación/estadística & datos numéricos , Exposición Profesional/análisis , Exposición Profesional/estadística & datos numéricos , Salud Laboral , Espectrofotometría Atómica
15.
J Environ Monit ; 14(2): 391-401, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22025111

RESUMEN

Occupational sampling and analysis for multiple elements is generally approached using various approved methods from authoritative government sources such as the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA), as well as consensus standards bodies such as ASTM International. The constituents of a sample can exist as unidentified compounds requiring sample preparation to be chosen appropriately, as in the case of beryllium in the form of beryllium oxide (BeO). An interlaboratory study was performed to collect analytical data from volunteer laboratories to examine the effectiveness of methods currently in use for preparation and analysis of samples containing calcined BeO powder. NIST SRM(®) 1877 high-fired BeO powder (1100 to 1200 °C calcining temperature; count median primary particle diameter 0.12 µm) was used to spike air filter media as a representative form of beryllium particulate matter present in workplace sampling that is known to be resistant to dissolution. The BeO powder standard reference material was gravimetrically prepared in a suspension and deposited onto 37 mm mixed cellulose ester air filters at five different levels between 0.5 µg and 25 µg of Be (as BeO). Sample sets consisting of five BeO-spiked filters (in duplicate) and two blank filters, for a total of twelve unique air filter samples per set, were submitted as blind samples to each of 27 participating laboratories. Participants were instructed to follow their current process for sample preparation and utilize their normal analytical methods for processing samples containing substances of this nature. Laboratories using more than one sample preparation and analysis method were provided with more than one sample set. Results from 34 data sets ultimately received from the 27 volunteer laboratories were subjected to applicable statistical analyses. The observed performance data show that sample preparations using nitric acid alone, or combinations of nitric and hydrochloric acids, are not effective for complete extraction of Be from the SRM 1877 refractory BeO particulate matter spiked on air filters; but that effective recovery can be achieved by using sample preparation procedures utilizing either sulfuric or hydrofluoric acid, or by using methodologies involving ammonium bifluoride with heating. Laboratories responsible for quantitative determination of Be in workplace samples that may contain high-fired BeO should use quality assurance schemes that include BeO-spiked sampling media, rather than solely media spiked with soluble Be compounds, and should ensure that methods capable of quantitative digestion of Be from the actual material present are used.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Berilio/análisis , Monitoreo del Ambiente/instrumentación , Filtración/instrumentación , Contaminantes Ocupacionales del Aire/química , Contaminantes Ocupacionales del Aire/normas , Berilio/química , Berilio/normas , Monitoreo del Ambiente/métodos , Monitoreo del Ambiente/normas , Laboratorios
16.
Open Res Eur ; 2: 34, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-37645268

RESUMEN

Due to the nature of health data, its sharing and reuse for research are limited by ethical, legal and technical barriers. The FAIR4Health project facilitated and promoted the application of FAIR principles in health research data, derived from the publicly funded health research initiatives to make them Findable, Accessible, Interoperable, and Reusable (FAIR). To confirm the feasibility of the FAIR4Health solution, we performed two pathfinder case studies to carry out federated machine learning algorithms on FAIRified datasets from five health research organizations. The case studies demonstrated the potential impact of the developed FAIR4Health solution on health outcomes and social care research. Finally, we promoted the FAIRified data to share and reuse in the European Union Health Research community, defining an effective EU-wide strategy for the use of FAIR principles in health research and preparing the ground for a roadmap for health research institutions. This scientific report presents a general overview of the FAIR4Health solution: from the FAIRification workflow design to translate raw data/metadata to FAIR data/metadata in the health research domain to the FAIR4Health demonstrators' performance.

19.
J Dev Behav Pediatr ; 41(3): 165-171, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31800528

RESUMEN

OBJECTIVE: To examine the emergence and trajectory of feeding difficulties in young children who are later diagnosed with autism spectrum disorder (ASD). METHODS: The Behavioral Pediatrics Feeding Assessment Scale (BPFAS) was administered to a sample of 93 toddlers with an older sibling with ASD-the high-risk group-and 62 toddlers with no known familial ASD-the low-risk group-as part of a larger infant sibling study. The BPFAS was completed by parents at 15, 18, 24, and 36 months of age. At 36 months, participants underwent a diagnostic assessment and were classified into 1 of the following 4 outcome groups: ASD, nontypical development, high-risk typically developing, and low-risk typically developing. The BPFAS was scored for total frequency of feeding difficulties and autism-specific factor scores previously described in the literature. RESULTS: The frequency of feeding difficulties increased significantly more rapidly in the ASD group between 15 and 36 months of age, and by 36 months, they exhibited a significantly higher total frequency score than all other groups. Analysis of the factor scores revealed a similar pattern for the food acceptance and mealtime behavior domains but no significant differences in the medical/oral motor domain. CONCLUSION: Feeding difficulties develop significantly more rapidly in children with ASD, with longitudinal monitoring revealing the steeper trajectory earlier than can be detected with cross-sectional analysis. Children with ASD are at risk of health and social consequences of poor feeding behavior that may potentially be minimized if addressed early and appropriately.


Asunto(s)
Trastorno del Espectro Autista/fisiopatología , Trastornos de la Conducta Infantil/fisiopatología , Desarrollo Infantil/fisiología , Conducta Alimentaria/fisiología , Trastornos de Ingestión y Alimentación en la Niñez/fisiopatología , Trastorno del Espectro Autista/complicaciones , Trastornos de la Conducta Infantil/etiología , Preescolar , Trastornos de Ingestión y Alimentación en la Niñez/etiología , Femenino , Humanos , Lactante , Estudios Longitudinales , Masculino , Riesgo , Hermanos
20.
J Environ Monit ; 11(2): 318-25, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19212588

RESUMEN

Because toxicities may differ for Cr(VI) compounds of varying solubility, some countries and organizations have promulgated different occupational exposure limits (OELs) for soluble and insoluble hexavalent chromium (Cr(VI)) compounds, and analytical methods are needed to determine these species in workplace air samples. To address this need, international standard methods ASTM D6832 and ISO 16740 have been published that describe sequential extraction techniques for soluble and insoluble Cr(VI) in samples collected from occupational settings. However, no published performance data were previously available for these Cr(VI) sequential extraction procedures. In this work, the sequential extraction methods outlined in the relevant international standards were investigated. The procedures tested involved the use of either deionized water or an ammonium sulfate/ammonium hydroxide buffer solution to target soluble Cr(VI) species. This was followed by extraction in a sodium carbonate/sodium hydroxide buffer solution to dissolve insoluble Cr(VI) compounds. Three-step sequential extraction with (1) water, (2) sulfate buffer and (3) carbonate buffer was also investigated. Sequential extractions were carried out on spiked samples of soluble, sparingly soluble and insoluble Cr(VI) compounds, and analyses were then generally carried out by using the diphenylcarbazide method. Similar experiments were performed on paint pigment samples and on airborne particulate filter samples collected from stainless steel welding. Potential interferences from soluble and insoluble Cr(III) compounds, as well as from Fe(II), were investigated. Interferences from Cr(III) species were generally absent, while the presence of Fe(II) resulted in low Cr(VI) recoveries. Two-step sequential extraction of spiked samples with (first) either water or sulfate buffer, and then carbonate buffer, yielded quantitative recoveries of soluble Cr(VI) and insoluble Cr(VI), respectively. Three-step sequential extraction gave excessively high recoveries of soluble Cr(VI), low recoveries of sparingly soluble Cr(VI), and quantitative recoveries of insoluble Cr(VI). Experiments on paint pigment samples using two-step extraction with water and carbonate buffer yielded varying percentages of relative fractions of soluble and insoluble Cr(VI). Sequential extractions of stainless steel welding fume air filter samples demonstrated the predominance of soluble Cr(VI) compounds in such samples. The performance data obtained in this work support the Cr(VI) sequential extraction procedures described in the international standards.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Fraccionamiento Químico/métodos , Cromo/análisis , Hidróxido de Amonio , Sulfato de Amonio/química , Carbonatos/química , Cromo/química , Filtración/métodos , Hidróxidos/química , Pintura/análisis , Sensibilidad y Especificidad , Hidróxido de Sodio/química , Solubilidad , Agua/química
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