Chronic toxicity of vanadium to flagfish

The 96-h LC50 of vanadium to adult American flagfish (Jordanella floridae) was 11.2 mg l⁻¹ in very hard water. Larvae showed 28-day LC50's of 1.13 and 1.88 mg l⁻¹ of vanadium with larger larvae being more resistant. These appeared to be thresholds of lethality. During continuous exposure for 96 days, larval growth and survival were the most sensitive indicators of vanadium toxicity and were marginally reduced at 0.17 mg l⁻¹. At 0.041 mg l⁻¹, there were no deleterious sublethal effects but there was definite stimulation of growth in females and of reproductive performance. The threshold for chronic toxicity was judged to be about 0.08 mg l⁻¹. The “safe”-to-lethal ratio was 0.007 and this could be used as an application factor for other species. There was no clear evidence that vanadium had any long-term cumulative toxicity.     

Moderators and mediators of the stress-aggression relationship: Executive function and state anger.

The present study examined the effects of executive function (i.e., EF) and anger/hostility on the relationship between stress (across individual stress domains, as well as at the aggregate level) and aggression. Two independent groups of participants—a college sample and a low-income community sample—were administered a battery of self-report measures concerning the subjective experience of stress, aggressive behaviors, and feelings of state anger and hostility in the last month, along with a battery of well-validated neuropsychological tests of EF. Across both samples, the stress domains that demonstrated the strongest associations with aggression were those involving chronic strains of daily living (e.g., job, financial, health) versus interpersonal stressors (e.g., family, romantic). In the community sample, analyses also revealed a significant interaction between perceived stress (aggregated across domains) and EF in predicting aggressive behavior. Specifically, participants with relatively low EF abilities, across different EF processes, showed a stronger relationship between different domains of stress and aggression in the last month. Similar effects were demonstrated in the college sample, although the interaction was not significant. In both samples, experiences of anger and hostility in the last month mediated the relationship between perceived stress (aggregate) and aggressive behavior among those low, but not high, in EF. These findings highlight the importance of higher-order cognitive processes in regulating appropriate affective and behavioral responses across different types of individuals, particularly among those experiencing high levels of stress. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The Gyricon rotating ball display

Abstract— The Gyricon display consists of hemispherical black and white (bichromal) balls contained in individual liquid-filled cavities and disposed to orient in an electrical field. This bistable reflective light display currently has a diffuse reflectance of more than 18% and a contrast ratio of more than 6:1. The viewing angle approaches that of paper. A new method of fabricating the bichromal balls has enabled practical realization of large-area high-quality displays.     

Nuclear magnetic resonance of3He superfluid confined in high porosity aerogel

We report pulsed nuclear magnetic resonance (NMR) measurements of the transverse frequency and magnetization of³ He confined in aerogel with 98.2% open volume porosity. A homogeneous superfluid phase is observed at pressures, P > 12 bar, accompanied by a sharp onset of frequency shifts showing little or no textural broadening; a result quite unexpected for³He confined in random porous media. The transition temperatures and order parameter are both significantly suppressed from their bulk values and the magnetization data indicate this low temperature phase is an equal-spin pairing superfluid. For NMR tipping angles greater than 40 ° the resonance frequency drops abruptly to the normal state value. This tip angle dependence is not consistent with either the bulk³He-A or³He-B superfluid phases.     

Synthesis and evaluation of hexafluorodimethylcarbinol functionalized polymers as microsensor coatings

Polystyrenes, polyacrylates, and poly(3,4-isoprenes) incorporating the hexafluorodimethylcarbinol functionality have been synthesized, characterized, and tested as microsensor coatings on a surface acoustic wave (SAW) device for dimethyl methylphosphonate (DMMP) vapor absorption sensitivity. The syntheses involved monomer functionalization and polymerization or hexafluoroacetone reaction with preformed polymer. All fluoroalcohol functionalized polymer coatings displayed sub parts per million level sensitivity with the slope of the absorption isotherm steepest at low DMMP concentrations. The order of sensitivity for the isomeric polystyrene fluoroalcohols (meta > para ? ortho) paralleled that of the relative free hydroxyl to hydrogen-bonded hydroxyl content. Strong hydrogen bonding between the fluoroalcohol polymers and DMMP vapor was observed by IR spectroscopy. Acylation of the fluoroalcohol group markedly reduced the DMMP sensitivity.     

Operator preferences for movement compatibility between radar hand control and display symbology.

As determined by operator preferences, which of 2 ways of relating hand controls to what appears on a radar screen is better? 3 groups of Ss, totaling 62, were each exposed to 2 display control relationships. They considered a way to relate hand movements directly to what appeared on the screen to be best. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trends in use and prospects for the future harvest of world fisheries resources

Estimates of the potential yield from the marine environment have varied between 20–1000 million metric tons because they were based on poor and incomplete data and differing approaches to trophic level evaluation. The data is improving slightly and the estimates are beginning to agree within half an order of magnitude. We believe that the yield of marine fisheries could ultimately be expanded to ca. 400 million metric tons, by utilizing presently known but underutilized resources, by opening new fisheries in areas like the Indian Ocean and Antarctic and by improving systems of regulating the catch and fishing effort. In order to meet the maximum potential of the marine environment we will have to harvest at a lower trophic level in the food chain because most fish in higher trophic levels are being harvested at their maximum sustainable yield. This increasing harvest of smaller fish, plus the increasing demand for fishmeal for animal feed will cause an increasing proportion of the fish harvested to be used for reduction to fishmeal and oil. One of 11 papers presented in the symposium “World Supply of Edible Oils and Proteins,” Atlantic City, October 1971.     

Comparative short-term tolerance of zebrafish, flagfish, and rainbow trout to five poisons including potential reference toxicants

Zebrafish (Brachydanio rerio) and flagfish (Jordanella floridae) were evaluated as potential standard species for aquatic bioassays in Canada by comparing their short-term tolerance to that of rainbow trout (Salmo gairdneri). When threshold or 10-day LC₅₀'s for rainbow trout were assigned a value of 1.0, corresponding values for zebrafish and flagfish were respectively: copper sulfate, 1.6, 7.2; sodium pentachlorophenate, 4.7, 7.6; phenol, 2.5, 3.1; picloram, 1.6, 0.55; and dodecyl sodium sulfate, 2.8, 2.4. On the average, zebrafish were 2.6 times as tolerant as trout, and flagfish 4.2 times. Ratios of zebrafish/trout LC₅₀'s were considerably less variable than flagfish/trout LC₅₀'s. Considering the known variable response of rainbow trout and a maximum ratio of only 7.6 for exotic/trout LC₅₀'s, responses of zebrafish and flagfish were judged not sufficiently different from those of rainbow trout to discount either exotic species from further consideration as a potential standard test-fish.As a reference toxicant, sodium pentachlorophenate presented difficulties with analysis and availability. Dodecyl sodium sulfate showed no threshold of acute lethality for trout and 5-yr-old DSS had about one-third the toxicity of 1-year old DSS. Phenol met all criteria considered for a reference toxicant.     

Presence of pressure ulcer prevention methods used among patients considered at risk versus those considered not at risk

PURPOSE: This study examined pressure ulcer-prevention strategies available for patients considered at risk versus those considered not at risk. DESIGN: The study used a prospective, longitudinal design. SETTING AND SUBJECTS: Six hundred ninety-four patients from units of five acute care hospitals, a rehabilitation facility, and two nurses' home care caseloads participated in the investigation. INSTRUMENTS: Data-collection instruments included the Braden Scale for risk assessment, demographic information, and the Pressure Ulcer-Prevention Strategies tool, which assessed for the presence of 16 pressure ulcer-prevention strategies. METHODS: All patients admitted to a participating unit during a 2-month period were followed up until discharge. Depending on the site, patients were assessed for the presence of pressure ulcer-prevention strategies one to three times per week. RESULTS: Patients in the at-risk group versus those in the not-at-risk group were more likely (p < 0.01) to have the head of the bed in a low position, a pressure-reducing bed surface, pressure ulcer prevention charted, a positioning wedge, incontinence cleanser and ointment, heel protection, a prevention care plan, a trapeze, and a posted turning schedule. The at-risk group had significantly (p < 0.01) more prevention strategies present than did the not-at-risk group. However, the percentage of patients placed on a pressure ulcer-prevention program was low for both groups. CONCLUSIONS: Pressure ulcer prevention was evident for the at-risk group, but at a low rate. Institutions must continue to explore this critical area affecting patient outcomes.     

Akathisia in adults with mental retardation: development of the Akathisia Ratings of Movement Scale (ARMS)

We developed an akathisia rating scale for use with persons who have mental retardation and screened for the occurrence of akathisia in three samples: 66 adults receiving maintenance neuroleptic treatment, 20 adults not receiving neuroleptics, and 8 adults undergoing neuroleptic dose reduction. The scale had an acceptable level of interrater reliability and validly measured group differences related to neuroleptic treatment status. Using an empirically derived cut-off-score, we estimated the prevalence rate for akathisia to be 5% in neuroleptic-free subjects, 17% in neuroleptic-maintenance subjects, and 25% in neuroleptic-reduction subjects. Akathisia, dyskinesia, and stereotypy manifested as qualitatively different movement topograhies. The occurrence of dyskinesia stereotyped movement disorder was associated significantly with an increased occurrence of akathisia.