493 research outputs found
Eating Disorders: A Study of University Type and Prevalence
Disordered eating has become an increasing problem, especially in western culture. A study was conducted to determine a possible relationship between disordered eating among college students and type of university. Previous studies allude to the possibility of private evangelical colleges yielding more eating disorders than private non-evangelical and public colleges. College students at two east coast universities were compared on the Eating Attitudes Test and a demographic questionnaire. The research indicated that prevalence of eating disorders is not significantly different between private evangelical institutions and private non-evangelical institutions. The findings show some background, prevalence, causes, and theoretical explanation of eating disorders
A Technical Look at the Eighty Per Cent Rule As Applied To Employee Selection Procedures
In litigation under Title VII of the Civil Rights Act of 1964, statistical data has been referred to as the only game in town. This characterization only slightly overstates the importance of statistical data to prove or rebut a case of employment discrimination. In the first decade of Title VII litigation, statistical analysis in the courts was relatively uncomplicated, sometimes involving a mere recital of percentage differences or lack thereof between minority and majority classes. In recent years, however, courts and Title VII litigants have begun to take a more sophisticated view of the use of statistics in Title VII litigation. Since statistics can be used both to support and to rebut allegations of discrimination, it is important that any data offered be statistically and logically valid
CONSUMER FOOD SAFETY BEHAVIOR: A CASE STUDY IN HAMBURGER COOKING AND ORDERING
More Americans are eating hamburgers more well-done than in the past, according to national surveys. This change reduced the risk of E. coli O157:H7 infection by an estimated 4.6 percent and reduced associated medical costs and productivity losses by an estimated $7.4 million annually. In a 1996 survey, respondents who were more concerned about the risk of foodborne illness cooked and ordered hamburgers more well-done than those who were less concerned. However, respondents who strongly preferred hamburgers less well-done cooked and ordered them that way, even after accounting for their concern about the risk of illness.hamburger doneness, ground beef, food safety, food safety education, E. coli O157:H7, consumer behavior, survey, risk, foodborne illness, risk perceptions, palatability, information, microbial pathogens, Food Consumption/Nutrition/Food Safety,
Effects of Display Location Within Simulated Driving Environments
Driving simulators offer researchers experimental control while minimizing safety issues and reducing costs relative to on-road and test track experimental procedures. However, with the control of the visual environment that simulators allow, it can be tempting to develop experimental protocols that utilize displays within the visual environment of the simulator. Such displays have the potential to differentially affect driving performance based on their location within the driving environment. A simulator experiment was conducted in order to assess the effects of having drivers fixate a display at nine different locations on the center channel of a DriveSafety driving simulator. In general, driving performance was best when the display was in the middle of the screen. Both horizontal and vertical deviations from the center of the screen resulted in increased lane position variability, and drivers tended to drive closer to the opposite lane boundary toward which they were fixating when a display was located to the left or right of the center. In addition, response times to a task presented in the display were faster when the display was located toward the center of the screen
Long-term residue removal under tillage decreases amoA-nitrifiers and stimulates nirS-denitrifier groups in the soil
No-till in continuous corn (Zea mays L.) production helps to keep an important volume of residues on the soil surface, creating management challenges that could be alleviated by residue removal for bioenergy or animal use. Crop residues, however, are essential to stimulate microbial nutrient cycling in agroecosystems. Thus, both residue removal and tillage options need to be fully evaluated for their impacts on ecosystem services related to soil health, including microbial N cycling. We explored the main steps of the microbial N cycle in relation to soil properties by using targeted gene abundance as a proxy following over a decade of residue removal in continuous corn systems either under no-till or chisel tillage. We used real-time quantitative polymerase chain reaction (qPCR) for the quantification of phylogenetic groups and functional gene screening of the soil microbial communities, including genes encoding critical enzymes of the microbial N cycle: nifH (N2 fixation), amoA (nitrification – ammonia oxidation), nirK and nirS (denitrification – nitrite reduction), and nosZ (denitrification – nitrous oxide reduction). Our results showed that long-term residue removal and tillage decreased soil organic matter (SOM), water aggregate stability (WAS), and the relative abundance (RA) of ammonia-oxidizing bacteria (AOB) carrying nitrifying amoA genes. Denitrifiers carrying nirS genes decreased under no-till as crop residue was removed. In addition, our results evidenced strong correlations among soil properties and phylogenetic groups of bacteria, archaea, and fungi. Overall, this study demonstrated limited but definite impacts of residue management and tillage on the soil environment, which could be exacerbated under less resilient conditions.Fil: Kim, N.. University of Illinois; Estados UnidosFil: Riggins, C. W.. University of Illinois; Estados UnidosFil: Rodríguez Zas, S.. University of Illinois; Estados UnidosFil: Zabaloy, Maria Celina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Villamil, Maria Bonita. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of Illinois; Estados Unido
Hydrogenase-3 Contributes to Anaerobic Acid Resistance of Escherichia coli
BACKGROUND: Hydrogen production by fermenting bacteria such as Escherichia coli offers a potential source of hydrogen biofuel. Because H(2) production involves consumption of 2H(+), hydrogenase expression is likely to involve pH response and regulation. Hydrogenase consumption of protons in E. coli has been implicated in acid resistance, the ability to survive exposure to acid levels (pH 2-2.5) that are three pH units lower than the pH limit of growth (pH 5-6). Enhanced survival in acid enables a larger infective inoculum to pass through the stomach and colonize the intestine. Most acid resistance mechanisms have been defined using aerobic cultures, but the use of anaerobic cultures will reveal novel acid resistance mechanisms. METHODS AND PRINCIPAL FINDINGS: We analyzed the pH regulation of bacterial hydrogenases in live cultures of E. coli K-12 W3110. During anaerobic growth in the range of pH 5 to 6.5, E. coli expresses three hydrogenase isoenzymes that reversibly oxidize H(2) to 2H(+). Anoxic conditions were used to determine which of the hydrogenase complexes contribute to acid resistance, measured as the survival of cultures grown at pH 5.5 without aeration and exposed for 2 hours at pH 2 or at pH 2.5. Survival of all strains in extreme acid was significantly lower in low oxygen than for aerated cultures. Deletion of hyc (Hyd-3) decreased anoxic acid survival 3-fold at pH 2.5, and 20-fold at pH 2, but had no effect on acid survival with aeration. Deletion of hyb (Hyd-2) did not significantly affect acid survival. The pH-dependence of H(2) production and consumption was tested using a H(2)-specific Clark-type electrode. Hyd-3-dependent H(2) production was increased 70-fold from pH 6.5 to 5.5, whereas Hyd-2-dependent H(2) consumption was maximal at alkaline pH. H(2) production, was unaffected by a shift in external or internal pH. H(2) production was associated with hycE expression levels as a function of external pH. CONCLUSIONS: Anaerobic growing cultures of E. coli generate H(2) via Hyd-3 at low external pH, and consume H(2) via Hyd-2 at high external pH. Hyd-3 proton conversion to H(2) is required for acid resistance in anaerobic cultures of E. coli
Acidification in corn monocultures favor fungi, ammonia oxidizing bacteria, and nirK-denitrifier groups
Agricultural practices of no-till and crop rotations are critical to counteract the detrimental effects of monocultures and tillage operations on ecosystem services related to soil health such as microbial N cycling. The present study explored the main steps of the microbial N cycle, using targeted gene abundance as a proxy, and concerning soil properties, following 19 and 20 years of crop monocultures and rotations of corn (Zea mays L.), and soybean [Glycine max (L.) Merr.], either under no-till or chisel tillage. Real-time quantitative polymerase chain reaction (qPCR) was implemented to estimate phylogenetic groups and functional genes related to the microbial N cycle: nifH (N2 fixation), amoA (nitrification) and nirK, nirS, and nosZ (denitrification). Our results indicate that long-term crop rotation and tillage decisions affect soil health as it relates to soil properties and microbial parameters. No-till management increased soil organic matter (SOM), decreased soil pH, and increased copy numbers of AOB (ammonia oxidizing bacteria). Crop rotations with more corn increased SOM, reduced soil pH, reduced AOA (ammonia oxidizing archaea) copy numbers, and increased AOB and fungal ITS copy numbers. NirK denitrifier groups were also enhanced under continuous corn. Altogether, the more corn years included in a crop rotation multiplies the amount of N needed to sustain yield levels, thereby intensifying the N cycle in these systems, potentially leading to acidification, enhanced bacterial nitrification, and creating an environment primed for N losses and increased N2O emissions.Fil: Behnke, G. D.. University of Illinois; Estados UnidosFil: Zabaloy, Maria Celina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Riggins, C. W.. University of Illinois; Estados UnidosFil: Rodríguez-Zas, S.. University of Illinois; Estados UnidosFil: Huang, L.. University of Illinois; Estados UnidosFil: Villamil, Maria Bonita. University of Illinois; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Investigating knowledge management factors affecting Chinese ICT firms performance: An integrated KM framework
This is an Author's Accepted Manuscript of an article published in the Journal of Information Systems Management, 28(1), 19 - 29, 2011, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/10580530.2011.536107.This article sets out to investigate the critical factors of Knowledge Management (KM) which are considered to have an impact on the performance of Chinese information and communication technology (ICT) firms. This study confirms that the cultural environment of an enterprise is central to its success in the context of China. It shows that a collaborated, trusted, and learning environment within ICT firms will have a positive impact on their KM performance
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