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1.
Ergonomics ; 66(6): 772-790, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36136049

RESUMEN

Interest in Maritime Autonomous Surface Ships (MASS) is increasing as it is predicted that they can bring improved safety, performance and operational capabilities. However, their introduction is associated with a number of enduring Human Factors challenges (e.g. difficulties monitoring automated systems) for human operators, with their 'remoteness' in shore-side control centres exacerbating issues. This paper aims to investigate underlying decision-making processes of operators of uncrewed vehicles using the theoretical foundation of the Perceptual Cycle Model (PCM). A case study of an Unmanned Aerial Vehicle (UAV) accident has been chosen as it bears similarities to the operation of MASS through means of a ground-based control centre. Two PCMs were developed; one to demonstrate what actually happened and one to demonstrate what should have happened. Comparing the models demonstrates the importance of operator situational awareness, clearly defined operator roles, training and interface design in making decisions when operating from remote control centres. Practitioner Summary: To investigate underlying decision-making processes of operators of uncrewed vehicles using the Perceptual Cycle Model, by using an UAV accident case study. The findings showed the importance of operator situational awareness, clearly defined operator roles, training and interface design in making decisions when monitoring uncrewed systems from remote control centres.


Asunto(s)
Navíos , Dispositivos Aéreos No Tripulados , Humanos , Concienciación
2.
Ergonomics ; 65(3): 384-406, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34319860

RESUMEN

Submarine control room layouts have remained similar across decades of operation, despite the introduction of new technologies that allow for the co-location of the sound and control room. Operation of an inwards, rather than outwards, facing ring control room configuration was examined in three scenarios: Return to Periscope Depth, Inshore Operations, and Dived Tracking. A case study design employed a serving team of qualified submariners participated in all three scenarios with high and low demand. Communications and activities in the control room were recorded and analysed using the Event Analysis of Systemic Teamwork (EAST) method. EAST models collaborative teamwork through social, information, and task networks. The results from the ring configuration were compared to an outward facing baseline of the contemporary control room layout with a separate sound and control room. The ring control room configuration increased communications between operators, leading to a more information exchanged, and more tasks completed. Practitioner summary: Control room design on submarines, and other domains, has traditionally been outward facing with supervisory staff looking over the shoulders of their subordinates. In this paper, and inward looking control room design was explored, with subordinate staff facing their supervisors. This design resulted in more information exchange and productive work.


Asunto(s)
Personal Militar , Navíos , Comunicación , Eficiencia , Humanos
3.
Ergonomics ; 65(2): 161-187, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34865613

RESUMEN

This state of the science review brings together the disparate literature of effective strategies for enhancing and accelerating team performance. The review evaluates and synthesises models and proposes recommended avenues for future research. The two major models of the Input-Mediator-Output-Input (IMOI) framework and the Big Five dimensions of teamwork were reviewed and both will need significant development for application to future teams comprising non-human agents. Research suggests that a multi-method approach is appropriate for team measurements, such as the integration of methods from self-report, observer ratings, event-based measurement and automated recordings. Simulations are recommended as the most effective team-based training interventions. The impact of new technology and autonomous agents is discussed with respect to the changing nature of teamwork. In particular, whether existing teamwork models and measures are suitable to support the design, operation and evaluation of human-nonhuman teams of the future. Practitioner summary: This review recommends a multi-method approach to the measurement and evaluation of teamwork. Team models will need to be adapted to describe interaction with non-human agents, which is what the future is most likely to hold. The most effective team training interventions use simulation-based approaches.


Asunto(s)
Grupo de Atención al Paciente , Humanos
4.
J Toxicol Environ Health B Crit Rev ; 24(8): 355-394, 2021 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-34542016

RESUMEN

In the wake of the Deepwater Horizon (DWH) oil spill, a number of government agencies, academic institutions, consultants, and nonprofit organizations conducted lab- and field-based research to understand the toxic effects of the oil. Lab testing was performed with a variety of fish, birds, turtles, and vertebrate cell lines (as well as invertebrates); field biologists conducted observations on fish, birds, turtles, and marine mammals; and epidemiologists carried out observational studies in humans. Eight years after the spill, scientists and resource managers held a workshop to summarize the similarities and differences in the effects of DWH oil on vertebrate taxa and to identify remaining gaps in our understanding of oil toxicity in wildlife and humans, building upon the cross-taxonomic synthesis initiated during the Natural Resource Damage Assessment. Across the studies, consistency was found in the types of toxic response observed in the different organisms. Impairment of stress responses and adrenal gland function, cardiotoxicity, immune system dysfunction, disruption of blood cells and their function, effects on locomotion, and oxidative damage were observed across taxa. This consistency suggests conservation in the mechanisms of action and disease pathogenesis. From a toxicological perspective, a logical progression of impacts was noted: from molecular and cellular effects that manifest as organ dysfunction, to systemic effects that compromise fitness, growth, reproductive potential, and survival. From a clinical perspective, adverse health effects from DWH oil spill exposure formed a suite of signs/symptomatic responses that at the highest doses/concentrations resulted in multi-organ system failure.


Asunto(s)
Exposición a Riesgos Ambientales/efectos adversos , Contaminación por Petróleo/efectos adversos , Contaminantes Químicos del Agua/toxicidad , Animales , Aves , Monitoreo del Ambiente/métodos , Peces , Humanos , Insuficiencia Multiorgánica/etiología , Petróleo/toxicidad , Tortugas , Vertebrados
5.
Environ Sci Technol ; 54(10): 6254-6261, 2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32310642

RESUMEN

Benthic organisms may be exposed to polycyclic aromatic hydrocarbons (PAHs) in marine sediments as the result of oil spills. PAH photoinduced toxicity, which has been documented in a wide range of early life stage (ELS) aquatic biota, is a phenomenon by which ultraviolet (UV) radiation potentiates the toxicity of photodynamic PAHs (often leading to mortality). Fiddler crabs (Uca longisignalis) are important ecosystem engineers that influence biogeochemical cycles via burrowing. As gravid females burrow, their eggs may bioaccumulate PAHs from contaminated sediments, leading to in ovo exposure. Consequently, free-swimming larvae exposed to intense UV may be at risk for photoinduced toxicity. In the present study, mature fiddler crabs were bred on oiled sediments contaminated via simulated tidal flux. Gravid females were transferred to clean water after 10 days, and larvae were collected at hatch. While in ovo exposures to oil alone did not affect survival, offspring that were subsequently exposed to full spectrum sunlight in clean water experienced significant mortality that corresponded with in ovo exposures to sediments containing ≥1455 µg/kg tPAH50. Results presented here provide evidence for the potential of photoinduced toxicity to occur in benthic organisms with free-swimming early life stages.


Asunto(s)
Braquiuros , Contaminación por Petróleo/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Animales , Ecosistema , Femenino , Sedimentos Geológicos , Plancton
6.
Environ Sci Technol ; 54(5): 2843-2850, 2020 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-32036658

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs) present in crude oil are known to impair visual development in fish. However, the underlying mechanism of PAH-induced toxicity to the visual system of fish is not understood. Embryonic zebrafish (Danio rerio) at 4 h post fertilization were exposed to weathered crude oil and assessed for visual function using an optokinetic response, with subsequent samples taken for immunohistochemistry and gene expression analysis. Cardiotoxicity was also assessed by measuring the heart rate, stroke volume, and cardiac output, as cardiac performance has been proposed to be a contributing factor to eye-associated malformations following oil exposure. Larvae exposed to the highest concentrations of crude oil (89.8 µg/L) exhibited an increased occurrence of bradycardia, though no changes in stroke volume or cardiac output were observed. However, genes important in eye development and phototransduction were downregulated in oil-exposed larvae, with an increased occurrence of cellular apoptosis, reduced neuronal connection, and reduced optokinetic behavioral response in zebrafish larvae.


Asunto(s)
Contaminación por Petróleo , Petróleo , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Animales , Apoptosis , Pez Cebra
7.
Dev Dyn ; 248(5): 337-350, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30884004

RESUMEN

BACKGROUND: Mahi-mahi (Coryphaena hippurus) is a commercially and ecologically important fish species that is widely distributed in tropical and subtropical waters. Biological attributes and reproductive capacities of mahi-mahi make it a tractable model for experimental studies. In this study, life development of cultured mahi-mahi from the zygote stage to adult has been described. RESULTS: A comprehensive developmental table has been created reporting development as primarily detailed observations of morphology. Additionally, physiological, behavioral, and molecular landmarks have been described to significantly contribute in the understanding of mahi life development. CONCLUSION: Remarkably, despite the vast difference in adult size, many developmental landmarks of mahi map quite closely onto the development and growth of Zebrafish and other warm-water, active Teleost fishes.


Asunto(s)
Estadios del Ciclo de Vida/fisiología , Perciformes/crecimiento & desarrollo , Animales , Conducta Animal , Domesticación , Peces , Larva/crecimiento & desarrollo , Fenotipo , Reproducción
8.
Ergonomics ; 63(3): 307-323, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31393223

RESUMEN

The separation of the sound and control rooms in Royal Navy submarines seems to be artefactually reducing the effectiveness of information transition and the overall productivity of the team. A proposed integrated sound and control room was tested in three scenarios: Return to Periscope Depth (RTPD), Inshore Operations (INSO) and Dived Tracking (DT). The activities and communications of a team of serving submariners were recorded in a control room, in a single case study design, comparing co-location and reduced crewing with a baseline of the separate sound and control room configurations that is representative of current submarines. The Event Analysis of Systemic Teamwork (EAST) method was used to examine changes in social, information and task networks. In general terms, the co-location of the submariner team led to more efficient communication and completion of tasks. Reducing the crew was more challenging in the higher demand scenarios. Practitioner Summary: There are constraints acting on control rooms, both in terms of physical space and crew size. This study compared conventional control room with co-location and reduced crew in turn. Teamwork improved in the collocated control room but the reduced crew struggled most under conditions of high demand. Abbreviations: DT: dived tracking; EAST: event analysis for systemic teamwork; H: high; INSO: inshore operations; L: low; OOW: office of the watch; OpsO: operations officer; Peri: periscope operator; RTPD: return to periscope depth; RN: royal navy; SoC: sonar controller; SoP: sonar operator; TMA: time-motion analyst.


Asunto(s)
Comunicación , Diseño de Equipo/métodos , Personal Militar , Navíos , Adulto , Simulación por Computador , Humanos , Persona de Mediana Edad
9.
Ecotoxicology ; 28(5): 597, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30989483

RESUMEN

The corrections are: In the 2nd sentence of the Statistical Analyses section, the current sentence lacks important statistical assumption wording.

10.
Ecotoxicology ; 28(3): 251-260, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30761428

RESUMEN

Mercury (Hg) deposited into aquatic sediments can be converted into the more toxic methylmercury (MeHg) by microbial activity. Atlantic stingrays (Hypanus sabinus) are an estuarine and nearshore species found in coastal regions of the western North Atlantic, occurring in multiple habitat types, and feeding mainly on benthic invertebrates. Mercury dynamics and speciation in stingrays have not been well examined. This study quantified total Hg and Hg species (Hg (II) and MeHg) in Atlantic stingrays sampled from Florida's Indian River Lagoon (IRL) from 2012 to 2013. Tissues (muscle and liver) collected from 29 stingrays were lyophilized and homogenized before being analyzed using a direct mercury analyzer. Concentrations of total Hg in muscle were positively related to stingray disk width, but concentrations in liver were not. Mean (±SD) total Hg in muscle (0.56 ± 0.30 mg/kg dw) was significantly higher than mean total Hg in liver (0.23 ± 0.19 mg/kg dw). Within liver tissue, percent MeHg (of total Hg) ranged from 31 to 99%. The ratio between total Hg in liver and total Hg in muscle was <1 for nearly all individuals, suggesting a lack of active hepatic demethylation and sequestration mechanisms. Concentrations of Hg in IRL Atlantic stingrays fall below concentrations known to result in direct toxicity to fishes; however, effects thresholds are not well understood for elasmobranchs. Comparisons of Hg concentrations in IRL Atlantic stingrays sampled previously (37 individuals in 1994) indicate that total Hg concentrations in muscle of Atlantic stingrays have decreased over the past two decades, suggesting a reduction in the bioavailable Hg in the IRL ecosystem.


Asunto(s)
Monitoreo del Ambiente , Mercurio/análisis , Alimentos Marinos/análisis , Rajidae , Animales , Ecosistema , Florida , Hígado/química , Compuestos de Metilmercurio/análisis , Músculos/química , Ríos , Contaminantes Químicos del Agua/análisis
11.
Environ Manage ; 63(4): 433-436, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30739149

RESUMEN

This editorial introduces the issue of selected papers that were presented at the third International Conference on Environmental Pollution, Restoration, and Management in Quy Nhon, Vietnam on 6-10 March 2017. While environmental problems caused by diverse municipal, industrial, and other economic development activities continue to increase in many Asian countries, public awareness about environmental management for public health and the environment remain at levels that favor accepting environmental degradation and impacts for tradeoffs with economic values. This special issue resulted from a conference that was organized to bringing scientists from developed and developing countries to Vietnam to share experiences, discuss environmental problems, and enhance future collaborations for research and training in support of better management plans for the environment and health. Papers published in this issue present original results from diverse research on current environmental management challenges in Vietnam and other Asian countries. The research areas include environmental contamination in groundwater and diet that affect human health, waste composting, and effects of wastewater effluent, which is one of the greatest challenges in most Asian countries. In addition, impacts of hazardous chemical emissions and related environmental management efforts, and sustainable development approaches are included.


Asunto(s)
Países en Desarrollo , Contaminación Ambiental , Asia , Humanos , Vietnam
12.
Ergonomics ; 62(2): 255-267, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29206624

RESUMEN

Flight within degraded visual conditions is a great challenge to pilots of rotary-wing craft. Environmental cues typically used to guide interpretation of speed, location and approach can become obscured, forcing the pilots to rely on data available from in-cockpit instrumentation. To ease the task of flight during degraded visual conditions, pilots require easy access to flight critical information. The current study examined the effect of 'Highways in the Sky' symbology and a conformal virtual pad for landing presented using a Head Up Display (HUD) on pilots' workload and situation awareness for both clear and degraded conditions across a series of simulated rotary-wing approach and landings. Results suggest that access to the HUD lead to significant improvements to pilots' situation awareness, especially within degraded visual conditions. Importantly, access to the HUD facilitated pilot awareness in all conditions. Results are discussed in terms of future HUD development. Practitioner Summary: This paper explores the use of a novel Heads Up Display, to facilitate rotary-wing pilots' situation awareness and workload for simulated flights in both clear and degraded visual conditions. Results suggest that access to HUD facilitated pilots' situation awareness, especially when flying in degraded conditions.


Asunto(s)
Aeronaves/instrumentación , Aviación/instrumentación , Concienciación , Pilotos/psicología , Carga de Trabajo/psicología , Adulto , Anciano , Aviación/métodos , Simulación por Computador , Presentación de Datos , Humanos , Masculino , Persona de Mediana Edad , Análisis y Desempeño de Tareas , Adulto Joven
13.
Environ Sci Technol ; 52(22): 13501-13510, 2018 11 20.
Artículo en Inglés | MEDLINE | ID: mdl-30376307

RESUMEN

In this study, we performed a systematic evaluation of global microRNA-mRNA interactions associated with the developmental toxicity of Deepwater Horizon oil using a combination of integrated mRNA and microRNA deep sequencing, expression profiling, gene ontology enrichment, and functional predictions by a series of advanced bioinformatic tools. After exposure to water accommodated fraction (WAF) of both weathered slick oil (0.5%, 1%, and 2%) and source oil (0.125%, 0.25%, and 0.5%) from the Deep Water Horizon oil spill, four dose-dependent miRNAs were identified, including three up-regulated (miR-23b, miR-34b, and miR-181b) and one down-regulated miRNAs (miR-203a) in mahi-mahi hatchings exposed from 6 h postfertilization (hpf) to 48 hpf. Consistent with morphological, physiological, and behavioral changes, the target genes of these miRNAs were largely involved in the development of the cardiovascular, visual, nervous system and associated toxicity pathways, suggesting that miRNAs play an essential role in regulating the responses to oil exposure. The results obtained from this study improve our understanding of the role of miRNAs and their target genes in relation to dose-dependent oil toxicity and provide the potential of using miRNAs as novel biomarkers in future oil studies.


Asunto(s)
MicroARNs , Perciformes , Contaminación por Petróleo , Petróleo , Contaminantes Químicos del Agua , Animales , Larva , ARN Mensajero
14.
Environ Sci Technol ; 52(15): 8774-8784, 2018 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-29943971

RESUMEN

Mercury is a global contaminant, which may be microbially transformed into methylmercury (MeHg), which bioaccumulates. This results in potentially toxic body burdens in high trophic level organisms in aquatic ecosystems and maternal transfer to offspring. We previously demonstrated effects on developing fish including hyperactivity, altered time-to-hatch, reduced survival, and dysregulation of the dopaminergic system. A link between gut microbiota and central nervous system function in teleosts has been established with implications for behavior. We sequenced gut microbiomes of fathead minnows exposed to dietary MeHg to determine microbiome effects. Dietary exposures were repeated with adult CD-1 mice. Metabolomics was used to screen for metabolome changes in mouse brain and larval fish, and results indicate effects on lipid metabolism and neurotransmission, supported by microbiome data. Findings suggest environmentally relevant exposure scenarios may cause xenobiotic-mediated dysbiosis of the gut microbiome, contributing to neurotoxicity. Furthermore, small-bodied teleosts may be a useful model species for studying certain types of neurodegenerative diseases, in lieu of higher vertebrates.


Asunto(s)
Cyprinidae , Microbioma Gastrointestinal , Contaminantes Químicos del Agua , Animales , Ecosistema , Metaboloma , Ratones
15.
Ecotoxicol Environ Saf ; 166: 186-191, 2018 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-30269013

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs) present in crude oil have been shown to cause the dysregulation of genes important in eye development and function, as well as morphological abnormalities of the eye. However, it is not currently understood how these changes in gene expression are manifested as deficits in visual function. Embryonic red drum (Sciaenops ocellatus) and sheepshead minnow (Cyprinodon variegatus) were exposed to water accommodated fractions (WAFs) of weathered crude oil and assessed for visual function using an optomotor response assay in early life-stage larvae, with subsequent samples taken for histological analysis of the eyes. Larvae of both species exposed to increasing concentrations of oil exhibited a reduced optomotor response. The mean diameters of retinal layers, which play an important role in visual function and image processing, were significantly reduced in oil-exposed sheepshead larvae, though not in red drum larvae. The present study provides evidence that weathered crude oil has a significant effect on visual function in early life-stage fishes.


Asunto(s)
Ojo/efectos de los fármacos , Peces Killi/crecimiento & desarrollo , Perciformes/crecimiento & desarrollo , Petróleo/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Ojo/anatomía & histología , Ojo/crecimiento & desarrollo , Peces Killi/anatomía & histología , Peces Killi/embriología , Peces Killi/fisiología , Larva/anatomía & histología , Larva/efectos de los fármacos , Fenómenos Fisiológicos Oculares/efectos de los fármacos , Perciformes/anatomía & histología , Perciformes/embriología , Perciformes/fisiología
16.
Ecotoxicology ; 27(4): 440-447, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29464533

RESUMEN

The 2010 explosion of the Deepwater Horizon (DWH) oil rig led to the release of millions of barrels of oil in the Gulf of Mexico. Oil in aquatic ecosystems exerts toxicity through multiple mechanisms, including photo-induced toxicity following co-exposure with UV radiation. The timing and location of the spill coincided with both fiddler crab reproduction and peak yearly UV intensities, putting early life stage fiddler crabs at risk of injury due to photo-induced toxicity. The present study assessed sensitivity of fiddler crab larvae to photo-induced toxicity during co-exposure to a range of environmentally relevant dilutions of high-energy water accommodated fractions of DWH oil, and either <10, 50, or 100% ambient sunlight, achieved with filters that allowed for variable UV penetration. Solar exposures (duration: 7-h per day) were conducted for two consecutive days, with a dark recovery period (duration: 17-h) in between. Survival was significantly decreased in treatments the presence of >10% UV and relatively low concentrations of oil. Results of the present study indicate fiddler crab larvae are sensitive to photo-induced toxicity in the presence of DWH oil. These results are of concern, as fiddler crabs play an important role as ecosystem engineers, modulating sediment biogeochemical processes via burrowing action. Furthermore, they occupy an important place in the food web in the Gulf of Mexico.


Asunto(s)
Braquiuros/efectos de los fármacos , Braquiuros/efectos de la radiación , Petróleo/toxicidad , Rayos Ultravioleta/efectos adversos , Contaminantes Químicos del Agua/toxicidad , Animales , Braquiuros/crecimiento & desarrollo , Golfo de México , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Larva/efectos de la radiación , Contaminación por Petróleo/efectos adversos
17.
Environ Sci Technol ; 51(17): 10162-10172, 2017 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-28768411

RESUMEN

The Deepwater Horizon (DWH) incident resulted in extensive oiling of the pelagic zone and shoreline habitats of many commercially important fish species. Exposure to the water-accommodated fraction (WAF) of oil from the spill causes developmental toxicity through cardiac defects in pelagic fish species. However, few studies have evaluated the effects of the oil on near-shore estuarine fish species such as red drum (Sciaenops ocellatus). Following exposure to a certified weathered slick oil (4.74 µg/L ∑PAH50) from the DWH event, significant sublethal impacts were observed ranging from impaired nervous system development [average 17 and 22% reductions in brain and eye area at 48 h postfertilization (hpf), respectively] to abnormal cardiac morphology (100% incidence at 24, 48, and 72 hpf) in red drum larvae. Consistent with the phenotypic responses, significantly differentially expressed transcripts, enriched gene ontology, and altered functions and canonical pathways predicted adverse outcomes in nervous and cardiovascular systems, with more pronounced changes at later larval stages. Our study demonstrated that the WAF of weathered slick oil of DWH caused morphological abnormalities predicted by a suite of advanced bioinformatic tools in early developing red drum and also provided the basis for a better understanding of molecular mechanisms of crude oil toxicity in fish.


Asunto(s)
Anomalías Inducidas por Medicamentos/veterinaria , Perciformes , Contaminación por Petróleo , Petróleo/toxicidad , Animales , Biología Computacional , Larva , Fenotipo , Contaminantes Químicos del Agua
18.
Environ Sci Technol ; 51(15): 8757-8762, 2017 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-28661662

RESUMEN

The Deepwater Horizon (DWH) oil spill resulted in the release of millions of barrels of oil into the Gulf of Mexico, and some marsh shorelines experienced heavy oiling including vegetation laid over under the weight of oil. Periwinkle snails (Littoraria irrorata) are a critical component of these impacted habitats, and population declines following oil spills, including DWH, have been documented. This study determined the effects of oil on marsh periwinkle movement and survivorship following exposure to oil. Snails were placed in chambers containing either unoiled or oiled laid over vegetation to represent a heavily impacted marsh habitat, with unoiled vertical structure at one end. In the first movement assay, snail movement to standing unoiled vegetation was significantly lower in oiled chambers (oil thickness ≈ 1 cm) compared to unoiled chambers, as the majority (∼75%) of snails in oiled habitats never reached standing unoiled vegetation after 72 h. In a second movement assay, there was no snail movement standing unoiled structure in chambers with oil thicknesses of 0.1 and 0.5 cm, while 73% of snails moved in unoiled chambers after 4h. A toxicity assay was then conducted by exposing snails to oil coated Spartina stems in chambers for periods up to 72 h, and mortality was monitored for 7 days post exposure. Snail survival decreased with increasing exposure time, and significant mortality (∼35%) was observed following an oil exposure of less than 24 h. Here, we have shown that oil impeded snail movement to clean habitat over a short distance and resulted in oil-exposure times that decreased survival. Taken together, along with declines documented by others in field surveys, these results suggest that marsh periwinkle snails may have been adversely affected following exposure to DWH oil.


Asunto(s)
Distribución Animal , Movimiento , Contaminación por Petróleo/efectos adversos , Caracoles , Animales , Ecosistema , Golfo de México , Dinámica Poblacional , Vinca , Humedales
19.
Hum Factors ; 59(8): 1263-1288, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28982016

RESUMEN

OBJECTIVE: The aim of this study was to use multiple command teams to provide empirical evidence for understanding communication flow, information pertinence, and tasks undertaken in a submarine control room when completing higher- and lower-demand inshore operation (INSO) scenarios. BACKGROUND: The focus of submarine operations has changed, and submarines are increasingly required to operate in costal littoral zones. However, submarine command team performance during INSO is not well understood, particularly from a sociotechnical systems perspective. METHOD: A submarine control-room simulator was built. The creation of networked workstations allowed a team of nine operators to perform tasks completed by submarine command teams during INSO. The Event Analysis of Systematic Teamwork method was used to model the social, task, and information networks and to describe command team performance. Ten teams were recruited for the study, affording statistical comparisons of how command-team roles and level of demand affected performance. RESULTS: Results indicated that the submarine command-team members are required to rapidly integrate sonar and visual data as the periscope is used, periodically, in a "duck-and-run" fashion, to maintain covertness. The fusion of such information is primarily completed by the operations officer (OPSO), with this operator experiencing significantly greater demand than any other operator. CONCLUSION: The OPSO was a bottleneck in the command team when completing INSO, experiencing similar load in both scenarios, suggesting that the command team may benefit from data synthesis tasks being more evenly distributed within the command team. APPLICATION: The work can inform future control-room design and command-team ways of working by identifying bottlenecks in terms of information and task flow between operators.


Asunto(s)
Comunicación , Conducta Cooperativa , Personal Militar , Desempeño Psicomotor , Navíos , Adulto , Humanos
20.
Arch Environ Contam Toxicol ; 66(4): 549-56, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24442186

RESUMEN

Copper is a common pollutant found in watersheds that exerts toxic effects on both invertebrates and vertebrates. Layer double hydroxide (LDH) clays are able to adsorb a wide range of contaminants through ion-exchange mechanisms. Coating LDH clays with various materials alters the aggregation of clay particles into the nano-size range, thus increasing relative surface area and offering great potential for contaminant remediation. The goal of this study was to determine if treatment with coated LDH clays decreases the toxicity of copper-containing solutions to Daphnia magna. Four LDH clays with different coatings used to alter hydrophobicity were as follows: used: Na(+) montmorillonite, Zn-Al LDH-nitrate, Zn-Al LDH-stearate, and Zn-Al LDH-carbonate. It was determined that coated LDH clays decreased copper toxicity by decreasing bioavailability and that smaller aggregate sizes decreased bioavailability the most. 96 h LC50 values increased by as much as 4.2 times with the treatment of the solutions with 100 mg/L LDH clay. Copper analysis of the clay and solutions indicated that the clays work by decreasing copper bioavailability by way of a binding mechanism. Coated LDH clays hold promise as a small-scale remediation tool or as an innovative tool for toxicity identification and evaluation characterization of metals.


Asunto(s)
Silicatos de Aluminio/química , Cobre/toxicidad , Restauración y Remediación Ambiental/métodos , Hidróxidos/química , Contaminantes Químicos del Agua/toxicidad , Adsorción , Animales , Arcilla , Cobre/química , Daphnia , Contaminantes Químicos del Agua/química
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