The dread factor: How hazards and safety training influence learning and performance.

On the basis of hypotheses derived from social and experiential learning theories, we meta-analytically investigated how safety training and workplace hazards impact the development of safety knowledge and safety performance. The results were consistent with an expected interaction between the level of engagement of safety training and hazardous event/exposure severity in the promotion of safety knowledge and performance. For safety knowledge and safety performance, highly engaging training was considerably more effective than less engaging training when hazardous event/exposure severity was high, whereas highly and less engaging training had comparable levels of effectiveness when hazardous event/exposure severity was low. Implications of these findings for theory testing and incorporating information on objective risk into workplace safety research and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of field conditions on low Reynolds number flow in a wetland

Stormwater runoff has been an environmental concern since the 1980s. Green infrastructure, such as constructed stormwater wetlands (CSWs), is a tool in stormwater management, however, little is known about the hydraulic diffusion processes that impact water quality in low flow, laminar (i.e. baseflow) conditions. Diffusion provides the mechanisms that distribute and mix water through a CSW and therefore how pollutants will be spread through the CSW impacting the water quality. Laboratory experiments were performed by Nepf, H.M., Sullivan, J.A., Zavistoski, R.A. [1997. A model for diffusion within emergent vegetation. Limnology and Oceanography, 42(8), 1735-1745], and Serra, T., Fernando, H.J.S., Rodriquez, R.V. [2004. Effects of emergent vegetation on lateral diffusion in wetland. Water Research, 38(1), 139-147] to examine the effect of plant density on diffusion in laminar flow conditions. Nepf, H.M. [1999. Drag, turbulence, and diffusion in flow through emergent vegetation. Water Resources Research, 35(2), 479-489] proposed a model predicting the diffusion coefficient based upon the plant density for both laminar and turbulent flow conditions. The present study examines the effect of field conditions on diffusion in a laminar flow field and verifies the diffusion model created by Nepf, H.M. [1999. Drag, turbulence, and diffusion in flow through emergent vegetation. Water Resources Research, 35(2), 479-489]. The results from the present study show that the laminar flow model, based solely on mechanical diffusion, is not sufficient for field conditions and the total diffusion model must be used. The variability in flow conditions and stem diameter found in the field produce pockets of turbulence and dead zones that must be considered to predict the diffusion coefficients in low flow CSWs. A sensitivity analysis of the dead zone term shows that the laboratory, field and diffusion models lie within an acceptable theoretical range for the observed or predicted diffusion coefficient. In addition, a model was created using the Danish Hydraulic Institutes Mike 21 software. Model results indicate that non-uniform velocities significantly affect the diffusion coefficient and a range of diffusion coefficients should be considered when designing CSWs.     

Reduced Fat Food Emulsions: Physicochemical,Sensory, and Biological Aspects

Fat plays multiple important roles in imparting desirable sensory attributes to emulsion-based food products, such as sauces, dressings, soups, beverages, and desserts. However, there is concern that over consumption of fats leads to increased incidences of chronic diseases, such as obesity, coronary heart disease, and diabetes. Consequently, there is a need to develop reduced fat products with desirable sensory profiles that match those of their full-fat counterparts. The successful design of high quality reduced-fat products requires an understanding of the many roles that fat plays in determining the sensory attributes of food emulsions, and of appropriate strategies to replace some or all of these attributes. This paper reviews our current understanding of the influence of fat on the physicochemical and physiological attributes of food emulsions, and highlights some of the main approaches that can be used to create high quality emulsion-based food products with reduced fat contents.     

Distributions of PM2.5 source strengths for cooking from the Research Triangle Park particulate matter panel study

Emission rates, decay rates, and cooking durations are reported from continuous PM2.5 (particulate matter less than 2.5 microm) concentrations measured using personal DataRam nephelometers (1-min time resolution) from the Research Triangle Park (RTP) PM panel study. The study (n = 37 participants) included monitoring for 7 consecutive days in each of four consecutive seasons (summer 2000 through spring 2001). Cooking episodes (n = 411) were selected using time-activity diaries and criteria for cooking event duration, peak concentration level, and decay curve quality. Averaged across all cooking events, mean source strengths were 36 mg/min (median = 12 mg/min), mean decay rates were 0.27 h(-1) (0.17 h(-1)), and mean cooking durations were 11 min (7 min). Cooking events were further separated into one of seven categories representing cooking method: burned food (oven cooking, toaster, or stovetop cooking), grilling, microwave, toaster oven, frying, oven cooking, and stovetop cooking. The highest mean source strengths were identified from burned food (mean = 470 mg/min), grilling (173 mg/min), and frying (60 mg/ min); differences between both burned food and grilling compared with all remaining cooking methods were statistically significant. Source strengths, decay rates, and cooking durations were also compared by season and typical meal times (8:00 a.m., 12:00 p.m., and 6:00 p.m.); differences were generally not statistically significant for these cases. Mean source strengths using electric appliances were typically a factor of 2 greater than those using gas appliances for identical cooking methods (frying, oven cooking, or stovetop cooking), although in all cases the difference was not statistically significant. Distributions of source strengths and decay rates for cooking events were also compared among study subjects to assess both within- and between-subject variability. Each subject's distribution of source strengths during the study tended to be either lower than the overall study average (and with lower variability) or higher than the overall study average (and with higher variability). No relationships could be found between source strength and either subject characteristics (age, gender, employment status) or home characteristic (daily air exchange rate). The large number of cooking events and the broad range of cooking activities included in this analysis makes the reported distributions of PM2.5 source strengths useful for probabilistic exposure modeling even though the study population was limited.     

Variations of alcohol impairment in different types, causes and contexts of injuries: results of emergency room studies from 16 countries

OBJECTIVE: The purpose of this paper is to document alcohol impairment (based on a blood alcohol content (BAC) of at least 80 mg%) for different types, causes and location contexts of injuries. DESIGN AND SETTING: Data from 45 studies with 11,536 injury patients were merged to determine variations in the percent of alcohol impairment among injury patients. In each study, emergency room (ER) injury patients were given a short interview on the circumstances of their injury and BAC was measured. RESULTS: Injury severity, measured by number of body regions injured was significantly associated with BACs over 80 mg%. The highest percentage of injury type to involve alcohol was head injury/concussion. In terms of causes of injuries, patients with alcohol impairment were significantly more likely to be involved in violence than any other cause (i.e., vehicle, falling, poisoning or burns). Finally, injuries occurring at a bar or restaurant were significantly more likely to involve alcohol impairment than any other setting. CONCLUSIONS: The results demonstrate considerable variation in the circumstances where alcohol is involved in injuries. These results may be useful for the development of prevention initiatives.     

Hydrogen and deuterium isotope effects beyond the electromagnetic force

A mechanism is presented concerning electrolysis of deuteriated water with a palladium cathode that is infused with deuterium (palladium deuteride) resulting in the formation of small amounts of radioactive tritium, excess energy (more than allowed by EMF chemistry alone) and the concomitant liberation of ⁴He. These net electron catalyzed nuclear chemical reactions (²H + ²H + e^? $\to$ ⁴He + e^? + heat) and (²H + ¹H + e^? $\to$ ³H + e^?) appear to be a result of respectively four and three isotope effects acting in combination with each other in a non-linear (chaotic) fashion to produce a metastable nuclear isomer of hydrogen-4 or hydrogen-3. The four isotope effects begin with the influx of electrons into the –PdDPdD Bravais lattice conduction band and consequent preferred rupture of individual weak Pd-D bonds (over those of PdH) in the cathode liberating D₂. This is followed by the newly freed deuterium capturing an electron yielding a di-neutron (_on_on). The _on_on then reacts with a deuterium or hydrogen (from protic impurity in the lattice) via phonon enforced quantum tunneling resulting in ^4mH or ³H respectively. The ^4mH quickly undergoes nuclear internal conversion to form ⁴He. These reactions involve the weak force (Feynman Diagrams are shown), but they take place in simple electrochemical systems that are normally thought of in terms of the electromagnetic forces only. The combined influence of the four isotope effects explains thousands of, what were considered, anomalous observations by top electrochemical researchers. The newly described mechanistic effects involve a very important and almost forgotten intermediate (the di-neutron) and may even involve unique safety concerns.     

Estrous cycle, pregnancy, and parity enhance performance of rats in object recognition or object placement tasks

Ovarian hormone elevations are associated with enhanced learning/memory. During behavioral estrus or pregnancy, progestins, such as progesterone (P(4)) and its metabolite 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP), are elevated due, in part, to corpora luteal and placental secretion. During 'pseudopregnancy', the induction of corpora luteal functioning results in a hormonal milieu analogous to pregnancy, which ceases after about 12 days, due to the lack of placental formation. Multiparity is also associated with enhanced learning/memory, perhaps due to prior steroid exposure during pregnancy. Given evidence that progestins and/or parity may influence cognition, we investigated how natural alterations in the progestin milieu influence cognitive performance. In Experiment 1, virgin rats (nulliparous) or rats with two prior pregnancies (multiparous) were assessed on the object placement and recognition tasks, when in high-estrogen/P(4) (behavioral estrus) or low-estrogen/P(4) (diestrus) phases of the estrous cycle. In Experiment 2, primiparous or multiparous rats were tested in the object placement and recognition tasks when not pregnant, pseudopregnant, or pregnant (between gestational days (GDs) 6 and 12). In Experiment 3, pregnant primiparous or multiparous rats were assessed daily in the object placement or recognition tasks. Females in natural states associated with higher endogenous progestins (behavioral estrus, pregnancy, multiparity) outperformed rats in low progestin states (diestrus, non-pregnancy, nulliparity) on the object placement and recognition tasks. In earlier pregnancy, multiparous, compared with primiparous, rats had a lower corticosterone, but higher estrogen levels, concomitant with better object placement performance. From GD 13 until post partum, primiparous rats had higher 3 alpha,5 alpha-THP levels and improved object placement performance compared with multiparous rats.     

Lens epithelial cell response to atmospheric pressure plasma modified poly(methylmethacrylate) surfaces

Selective control of cellular response to polymeric biomaterials is an important consideration for many ocular implant applications. In particular, there is often a need to have one surface of an ophthalmic implant capable of promoting cell attachment while the other needs to be resistant to this effect. In this study, an atmospheric pressure dielectric barrier discharge (DBD) has been used to modify the surface region of poly(methyl methacrylate) (PMMA), a well established ocular biomaterial, with the aim of promoting a controlled response to human lens epithelial cells (LEC) cultured thereon. The DBD plasma discharge environment has also been employed to chemically graft a layer of poly(ethylene glycol) methyl ether methacrylate (PEGMA) onto the PMMA and the response to LEC likewise determined. Two different molecular weights of PEGMA, namely 1000 and 2000 MW were used in these experiments. The LEC response to DBD treated polystyrene (PS) samples has also been examined as a positive control and to help to further elucidate the nature of the modified surfaces. The LEC adhered and proliferated readily on the DBD treated PMMA and PS surfaces when compared to the pristine polymer samples which showed little or no cell response. The PMMA and PS surfaces that had been DBD grafted with the PEGMA₁₀₀₀ layer were found to have some adhered cells. However, on closer inspection, these cells were clearly on the verge of detaching. In the case of the PEGMA₂₀₀₀ grafted surfaces no cells were observed indicating that the higher molecular weight PEGMA has been able to attain a surface conformation that is capable of resisting cell attachment in vitro.     

Semantic priming in young and older adults: Evidence for age constancy in automatic and attentional processes.

Automatic and attentional components of semantic priming and the relation of each to episodic memory were evaluated in young and older adults. Category names served as prime words, and the relatedness of the prime to a subsequent lexical decision target was varied orthogonally with whether the target category was expected or unexpected. At a prime-target stimulus-onset asynchrony (SOA) of 410 ms, target words in the same category had faster lexical decision latencies than did different category targets. This effect was not significant at a 1,550-ms SOA and was attributed to automatic processes. Expected category targets had faster latencies than unexpected category targets at the 410-ms SOA, and the magnitude of the effect increased at the 1,550-ms SOA. This effect was attributed to attentional processes. These patterns of priming were obtained for both age groups, but in a surprise memory test older adults had poorer recall of primes and targets. We discuss the implications of these results for the hypothesis that older adults suffer deficits in selective attention and for the related hypothesis that attentional deficits impair semantic processing, which causes memory decrements in old age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)