Defending the Wrist Deviation Test for Carpal Tunnel Syndrome Screening: A Comparison of Vibration Thresholds and Distal Motor Latency

This research used distal motor latency (DML) and vibration thresholds (VT) to evaluate 84 hand activity and wrist deviation combinations to determine the best association with carpal tunnel syndrome (CTS). Female volunteers, 2 healthy and 2 CTS diagnosed, were age matched and operated a keyboard for 4 hrs a day. Room temperature was 28°C(±2). Beginning DML and VT were taken with a relaxed neutral posture hand. The wrist was deviated in a randomly selected combination, and determinations were taken at 5-min intervals. The trial ended at 20 min or when discomfort was felt. The CTS conditions were discriminated by pain four times, DML once, and VT 14 times. Vibrometry was the most consistent CTS discriminator. The best VT results for wrist positions were obtained with wrist extension and extended extension, whereas the unclenched, clenched, and loaded power grip activities proved to be the most consistent hand activities.     

Paving the Way for Invasive Species: Road Type and the Spread of Common Ragweed (<Emphasis Type="Italic">Ambrosia artemisiifolia</Emphasis>)

Roads function as prime habitats and corridors for invasive plant species. Yet despite the diversity of road types, there is little research on the influence of these types on the spread of invaders. Common ragweed (Ambrosia artemisiifolia), a plant producing large amounts of allergenic pollen, was selected as a species model for examining the impact of road type on the spread of invasive plants. We examined this relationship in an agricultural region of Quebec, Canada. We mapped plant distribution along different road types, and constructed a model of species presence. Common ragweed was found in almost all sampling sites located along regional (97%) and local paved (81%) roads. However, verges of unpaved local roads were rarely (13%) colonized by the plant. A model (53% of variance explained), constructed with only four variables (paved regional roads, paved local roads, recently mown road verges, forest cover), correctly predicted (success rate: 89%) the spatial distribution of common ragweed. Results support the hypothesis that attributes associated with paved roads strongly favour the spread of an opportunistic invasive plant species. Specifically, larger verges and greater disturbance associated with higher traffic volume create propitious conditions for common ragweed. To date, emphasis has been placed on controlling the plant in agricultural fields, even though roadsides are probably a much larger seed source. Strategies for controlling the weed along roads have only focused on major highways, even though the considerable populations along local roads also contribute to the production of pollen. Management prioritizations developed to control common ragweed are thus questionable.     

Oxygen supply for oxyfuel CO2 capture

This paper presents the results of a study to develop Air Products’ air separation unit (ASU) offerings for oxyfuel coal CO₂ capture projects. A scalable “reference plant” concept is described to match particular sizes of power generation equipment, taking into account factors such as safety, reliability, operating flexibility, efficiency, and low capital cost. We describe the selection of a process cycle to exploit the low purity requirements, as well as the options for compression machinery and drivers as the scale of the plant increases and the sizes of referenced equipment limit the possibilities. We also explore integration with other elements of the system, such as preheating condensate or heating and expanding pressurised nitrogen. In addition, we consider how the ASU affects the flexibility of the oxyfuel system and discuss how its power consumption can be reduced during periods of high power demand. Finally, the advantages and disadvantages of different execution strategies for air separation unit projects are discussed, as well as alternative commercial models for the supply of oxygen.     

On estimating the exponent of power-law frequency distributions

Power-law frequency distributions characterize a wide array of natural phenomena. In ecology, biology, and many physical and social sciences, the exponents of these power laws are estimated to draw inference about the processes underlying the phenomenon, to test theoretical models, and to scale up from local observations to global patterns. Therefore, it is essential that these exponents be estimated accurately. Unfortunately, the binning-based methods traditionally used in ecology and other disciplines perform quite poorly. Here we discuss more sophisticated methods for fitting these exponents based on cumulative distribution functions and maximum likelihood estimation. We illustrate their superior performance at estimating known exponents and provide details on how and when ecologists should use them. Our results confirm that maximum likelihood estimation outperforms other methods in both accuracy and precision. Because of the use of biased statistical methods for estimating the exponent, the conclusions of several recently published papers should be revisited.     

Using single- and multi-target regression trees and ensembles to model a compound index of vegetation condition

An important consideration in conservation and biodiversity planning is an appreciation of the condition or integrity of ecosystems. In this study, we have applied various machine learning methods to the problem of predicting the condition or quality of the remnant indigenous vegetation across an extensive area of south-eastern Australia—the state of Victoria. The field data were obtained using the ‘habitat hectares’ approach. This rapid assessment technique produces multiple scores that describe the condition of various attributes of the vegetation at a given site. Multiple sites were assessed and subsequently circumscribed with GIS and remote-sensed data.     

NUTRIENT LOAD CHARACTERIZATION FROM INTEGRATED SOURCE DATA FOR THE LOWER MISSISSIPPI RWER1

ABSTRACT: Nutrient data from all available sources for the lower Mississippi River were examined for potential differences among sampling agencies and geographic locations for the period between 1960 and 1998. Monthly means grouped by parameter, sampling location and agency, were calculated and compared as paired sets, excluding those months where data were not available for both sets. Some significant differences were found between various agencies collecting nutrient data on the river, as well as between various stretches of river, especially in the case of phosphorus nutrient data. Results were used to synthesize data sets from which a history of nutrient loading in the Mississippi River was determined. General trends in nitrate+nitrite, total Kjeldahl nitrogen, orthophosphate, total phosphorus and silica loads, as well as changes in nutrient proportions and the specific limiting nutrient (by month) are reported. This study provides a useful summary of contemporary and historical nutrient data that may assist in the evaluation of Mississippi River water quality and its potential effect on the Gulf of Mexico.     

Young females' attention toward road safety images: An ERP study of the revised reinforcement sensitivity theory

Objective: This study examined whether reward and punishment sensitivities, as conceptualized by Gray and McNaughton's revised reinforcement sensitivity theory (RST), influenced young female drivers' attention toward a series of positive and negative antispeeding advertisement images. Young females' increasing crash risk is associated with their engagement in risky behaviors, which, in turn, has been associated with a stronger behavioral approach system (BAS; sensitive to rewards). It was predicted that individuals with a stronger BAS would elicit larger N100 and N200 mean amplitudes (reflecting greater attention) toward the positive images. Similar associations were predicted in relation to the fight–flight–freeze system (FFFS; sensitive to punishments) for negative images.

Method: Twenty-four female drivers (17–25 years; final N = 16) completed Corr-Cooper's RST-Personality Questionnaire, prior to undergoing an event-related potential computerized visual task (i.e., oddball paradigm) that included positive, negative, and neutral images as targets against checkerboard image distractors.

Results: Contrary to expectations, individuals with a stronger BAS (Reward Reactivity and Impulsivity) demonstrated significantly larger N200 mean amplitudes at the Cz electrode site on presentation of the negative images than those with a weaker BAS. No other significant RST effects were found.

Conclusions: These findings provide some preliminary objective support for the use of negative emotion-based road safety advertisements for young females. Further, this study provides support for using psychophysiological measures to enhance understanding of traffic injury persuasion.     

Specialisations of swimming muscles in the pelagic antarctic fish Pleuragramma antarcticum

The distribution and ultrastructure of muscle-fibre types has been investigated in adult and juvenile specimens of the pelagic high-antarctic silverfish Pleuragramma antarcticum Boulenger, 1902 collected from the South Shetland Islands during the winter of 1984/1985. Two main fibre-types were identified in araldite-embedded material. The axial musculature was mainly composed of poorly vascularised, largediameter muscle fibres which were densely packed with myofibrils (volume density 81 and 72% for adults and juveniles, respectively). These ultrastructural characteristics are typical of fast-twitch fibres. The number of capillaries ner unit cross-sectional area and the volume density of mito