Prenatal diagnosis of molybdenum cofactor deficiency and isolated sulfite oxidase deficiency

Molybdenum cofactor deficiency and isolated sulfite oxidase deficiency are autosomal recessive inborn errors of metabolism with severe neurological symptoms resulting from a lack of sulfite oxidase activity. The deficiencies can be diagnosed prenatally by monitoring sulfite oxidase activity in chorionic villus sampling (CVS) tissue. In those families in which the specific defects have been identified, diagnosis can be achieved by mutation analysis or linkage studies directed at affected genes. These include MOCS1, MOCS2 or GEPH, in cases of molybdenum cofactor deficiency, or SUOX in patients with isolated sulfite oxidase deficiency. Copyright © 2002 John Wiley & Sons, Ltd.     

Selectivity of Nano Zerovalent Iron in In Situ Chemical Reduction: Challenges and Improvements

Nano zerovalent iron (nZVI) is a promising remediation technology utilizing in situ chemical reduction (ISCR) to clean up contaminated groundwater at hazardous waste sites. The small particle size and large surface area of nZVI result in high reactivity and rapid destruction of contaminants. Over the past 20 years, a great deal of research has advanced the nZVI technology from bench‐scale tests to field‐scale applications. However, to date, the overall number of well‐characterized nZVI field deployments is still small compared to other alternative remedies that are more widely applied. Apart from the relatively high material cost of nZVI and questions regarding possible nanotoxicological side effects, one of the major obstacles to the widespread utilization of nZVI in the field is its short persistence in the environment due to natural reductant demand (NRD). The NRD for nZVI is predominantly due to reduction of water, but other reactions with naturally present oxidants (e.g., oxygen) occur, resulting in situ conditions that are reducing (high in ferrous iron phases and H₂) but with little or no Fe(0). This article reviews the main biogeochemical processes that determine the selectivity and longevity of nZVI, summarizes data from prior (laboratory and field) studies on the longevity of various common types of nZVI, and describes modifications of nZVI that could improve its selectivity and longevity for full‐scale applications of ISCR. © 2016 Wiley Periodicals, Inc.     

Ergonomic evaluation of a new truck seat design: a field study

A postural evaluation of commercial licensed truck drivers was conducted to determine the ergonomic benefits of a truck seat prototype in comparison with an industry standard seat. Twenty commercially licensed truck drivers were recruited to perform a 90-min driving task. Postures were assessed using accelerometers and a backrest and seat pan pressure mapping system. Subjective discomfort measurements were monitored using two questionnaires: ratings of perceived discomfort (RPD) and the automotive seating discomfort questionnaire (ASDQ). Participants reported significantly higher discomfort scores when sitting in the industry standard seat. Participants sat with more lumbar lordosis and assumed a more extended thoracic posture when seated in the prototype. Pairing the gluteal backrest panel with the adjustable seat pan also helped reduce the average sitting pressure on both the seat pan and the backrest. The prototype provided several postural benefits for commercially certified truck drivers, as it did for a young and healthy population.     

Air quality impact of carbon monoxide emission from diesel engine electric power generators

An emissions inventory and the AERMOD View dispersion model were used to estimate the concentrations and the potential effects of carbon monoxide (CO) from diesel engine electric power generators operated by and providing electricity to a textile factory in Nigeria on its host air shed. The CO emissions from simultaneous operations of all of the electric power generators in the factory resulted in: 1‐hr average CO emissions of 4.2 to 54.5 micrograms per cubic meters (μg/m³) and 24‐hr average CO emissions of 0.3 to 20.9 μg/m³. The estimated 1‐hr averaging period maximum ground‐level concentrations of CO were deposited within the factory, while the 24‐hr maximum ground‐level concentrations are estimated at a distance 90 meters (m) from the factory in a southeast direction. The ground‐level concentrations of CO emanating from the textile factory are within the stipulated ambient air quality standards.     

Surface‐Water Nutrient Conditions and Sources in the United States Pacific Northwest1

Wise, Daniel R. and Henry M. Johnson, 2011. Surface‐Water Nutrient Conditions and Sources in the United States Pacific Northwest. Journal of the American Water Resources Association (JAWRA) 47(5):1110‐1135. DOI: 10.1111/j.1752‐1688.2011.00580.x Abstract: The SPAtially Referenced Regressions On Watershed attributes (SPARROW) model was used to perform an assessment of surface‐water nutrient conditions and to identify important nutrient sources in watersheds of the Pacific Northwest region of the United States (U.S.) for the year 2002. Our models included variables representing nutrient sources as well as landscape characteristics that affect nutrient delivery to streams. Annual nutrient yields were higher in watersheds on the wetter, west side of the Cascade Range compared to watersheds on the drier, east side. High nutrient enrichment (relative to the U.S. Environmental Protection Agency’s recommended nutrient criteria) was estimated in watersheds throughout the region. Forest land was generally the largest source of total nitrogen stream load and geologic material was generally the largest source of total phosphorus stream load generated within the 12,039 modeled watersheds. These results reflected the prevalence of these two natural sources and the low input from other nutrient sources across the region. However, the combined input from agriculture, point sources, and developed land, rather than natural nutrient sources, was responsible for most of the nutrient load discharged from many of the largest watersheds. Our results provided an understanding of the regional patterns in surface‐water nutrient conditions and should be useful to environmental managers in future water‐quality planning efforts.     

Effects of Disturbance Associated With Seismic Exploration for Oil and Gas Reserves in Coastal Marshes

Anthropogenic disturbances in wetland ecosystems can alter the composition and structure of plant assemblages and affect system functions. Extensive oil and gas extraction has occurred in wetland habitats along the northern Gulf of Mexico coast since the early 1900s. Activities involved with three-dimensional (3D) seismic exploration for these resources cause various disturbances to vegetation and soils. We documented the impact of a 3D seismic survey in coastal marshes in Louisiana, USA, along transects established before exploration began. Two semi-impounded marshes dominated by Spartina patens were in the area surveyed. Vegetation, soil, and water physicochemical data were collected before the survey, about 6 weeks following its completion, and every 3 months thereafter for 2 years. Soil cores for seed bank emergence experiments were also collected. Maximum vegetation height at impact sites was reduced in both marshes 6 weeks following the survey. In one marsh, total vegetation cover was also reduced, and dead vegetation cover increased, at impact sites 6 weeks after the survey. These effects, however, did not persist 3 months later. No effects on soil or water properties were identified. The total number of seeds that germinated during greenhouse studies increased at impact sites 5 months following the survey in both marshes. Although some seed bank effects persisted 1 year, these effects were not reflected in standing vegetation. The marshes studied were therefore resilient to the impacts resulting from 3D seismic exploration because vegetation responses were short term in that they could not be identified a few months following survey completion.     

On‐target deposition of aerially applied deltamethrin

Abstract

The mean amount of deltamethrin deposited on natural substrates (i.e., soil and vegetation) in three experiments was 63, 73, and 76% of applied. Composite samples taken from 16 sites/replicate gave representative and repeatable measures of deposition. The use of Teflon discs as artificial targets to measure aerial deposition was investigated. The discs had only 34–71% mean trapping efficiency for the spray droplets. Deposition was quite variable among different sampling sites within a field (CV=73–83%). Much of this variation was caused by irregular overlapping of spray swaths.     

The effects of starvation and acute low salinity exposure on food intake in the Dungeness crab, Cancer magister

Adult Cancer magister make forays into hyposaline estuarine habitats during times of high food abundance. However, as weak osmoregulators, they are poorly equipped to deal with the concurrent demands of osmoregulation and digestion. Therefore, the potential interaction between nutritional status and feeding in a physiologically challenging environment was investigated. Changes in the proportion of crabs feeding, the amount of food consumed, the time spent feeding, and the efficiency with which a meal was consumed were examined in response to the length and severity of hyposaline exposure, and the duration of starvation. Reductions in the (a) number of animals feeding, (b) the amount of food consumed, and (c) the time spent feeding were observed in salinities where C. magister actively osmoregulates the concentration of its internal fluids. Although this reduction in feeding was likely a stress response, the crabs were able evaluate the level of salinity stress: there was a dose-dependent reduction in feeding, and they were able to discriminate between salinities separated by as little as 3.5‰. The likelihood that animals would feed in low salinity increased with starvation. Thus, the aversion to food uptake in physiologically stressful conditions may be overridden by the need to procure nutrients. In the natural environment, we suggest that C. magister are employing an ‘eat and run’ strategy, moving into the estuary, consuming a meal, and retreating to higher salinities to digest.     

Towards a Duty of Care for Biodiversity

The decline in biodiversity is a worldwide phenomenon, with current rates of species extinction more dramatic than any previously recorded. Habitat loss has been identified as the major cause of biodiversity decline. In this article we suggest that a statutory duty of care would complement the current mix of policy options for biodiversity conservation. Obstacles hindering the introduction of a statutory duty of care include linguistic ambiguity about the terms ‘duty of care’ and ‘stewardship’ and how they are applied in a natural resource management context, and the absence of a mechanism to guide its implementation. Drawing on international literature and key informant interviews we have articulated characteristics of duty of care to reduce linguistic ambiguity, and developed a framework for implementing a duty of care for biodiversity at the regional scale. The framework draws on key elements of the common law ‘duty of care’, the concepts of ‘taking reasonable care’ and ‘avoiding foreseeable harm’, in its logic. Core elements of the framework include desired outcomes for biodiversity, supported by current recommended practices. The focus on outcomes provides opportunities for the development of innovative management practices. The framework incorporates multiple pathways for the redress of non-compliance including tiered negative sanctions, and positive measures to encourage compliance. Importantly, the framework addresses the need for change and adaptation that is a necessary part of biodiversity management.     

Whole-body vibration in heavy equipment operators of a front-end loader: Role of task exposure and tire configuration with and without traction chains

IntroductionThis study measured whole-body vibration (WBV) exposures in front-end loader operators, and evaluated the effects of traction chains and work tasks on their WBV exposures.MethodWBV exposures were measured and compared across three different front-end loader tire configurations: (a) stock rubber tires, (b) rubber tires with ladder chains, and (c) rubber tires with basket chains. The operators completed three distinct standardized tasks: driving on a city street, simulated plowing, and a simulated scooping and dumping task. A portable data acquisition system collected tri-axial time weighted and raw WBV data per ISO 2631-1 and 2631-5 standards. In addition, Global Positioning System (GPS) data were collected in order to compare loader speeds across tire conditions and the standardized tasks.ResultsRelative to the stock rubber tires, both types of tire chains significantly increased WBV exposures with the ladder chains having substantially higher WBV exposures compared to basket chains. Additionally, there were task dependent differences in WBV exposures. During the driving task, the z-axis (up and down) was the predominant exposure; the plowing task had a more even distribution of exposure across all three axes; while during scooping and dumping task, the x-axis (fore and aft) had the highest WBV exposures. The GPS data indicated that there were significant speed differences across tasks but not between the basket and ladder chain conditions.ConclusionsTires with ladder chains increased the front-end loader operators' exposure to WBV above the ISO 2631-1 recommended eight hour action limit increasing risk for adverse health effects. Although more expensive, basket chains are recommended over ladder chains since they substantially lowered the front-end loader operator's exposures and may ultimately reduce vibration related wear and tear on the vehicle.Impact on IndustryIn order to reduce a heavy equipment vehicle (HEV) operator’s chances for developing low back pain, this study provides information that health and safety professionals can use to reduce whole-body vibration (WBV) exposures when operating front-end wheel loaders with traction chains.