539 research outputs found

    COMMUNITY PERTURBATION ASSOCIATED WITH NEW ZEALAND MUDSNAIL (POTAMAPYRGUS ANTIPODARUM) INVASION: DISCREPANCIES IN TEMPORAL AND SPATIAL ASSESSMENT

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    Invasive species have the potential to alter the ecosystems within which they establish as well as adjacent but uninvaded ecosystems by altering the flow of nutrients or biota across system boundaries. New Zealand mudsnails (Potamopyrgus antipodarum; NZMS) are often very abundant where they invade, sequestering the majority of stream primary production. This sequestering of production may reduce aquatic insect production, subsequent insect emergence and subsidies to riparian ecosystems. Tetragnathid spiders, an insectivorous riparian specialist, are dependent on the emergence of aquatic insects and are typical indicators of aquatic insect subsidies to riparian zones. In addition, NZMS invasions can result in persistent community shifts in aquatic insect composition, potentially resulting in lasting impacts to subsidies. We hypothesized that in river sections where they are currently very abundant NZMS would have negative impacts on benthic aquatic insect biomass, reducing the emergence of aquatic insects and spiders that feed on them. We sampled benthic and emerging aquatic invertebrates and tetragnathid spider densities at five locations with various densities of NZMS on two invaded rivers in the Western United States. In the Portneuf River, ID NZMS are currently very abundant while in the Madison River, MT they were abundant fifteen years ago but have since declined. We also analyzed 17 years of benthic community data taken from one location on the Madison River during the NZMS invasion to examine how benthic community composition (and emergent taxa) shifted during peak NZMS densities. In contrast with our expectations, NZMS were positively associated with non-NZMS benthic invertebrate biomass and emergent biomass. Similar to our expectations, spiders had a positive association with emergent biomass and riparian habitat availability. But because of a 200- fold difference in secondary production among sites (sites with high NZMS biomass also had high non-NZMS invertebrate biomass) comparing sites with different densities potentially confounded NZMS density with potential productivity of the site. Examination of time series data of aquatic invertebrate community highlighted that NZMS were associated with lasting changes in benthic community composition marked by reductions in emerging taxa, including Ephmeroptera and Odonata and increases in Baetidae and Tubificidae. Pre-invasion data rarely exist therefore multiple, complementary means of investigation are often necessary to fully evaluate potential impacts of invaders

    Emotions in business-to-business service relationships

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    Emotion in business-to-business service relationships regarding cargo services is explored. The service relationship is characterised by mutual trust and cooperation. Contact is mainly via telephone or e-mail with some face-to-face interactions and participants providing a complex, multi-skilled seamless service. Experience rather than training plays a vital role with long-term service relationships built up and maintained. Emotional sensitivity is acquired partly by experience and a repeat customer base but mainly through a genuine desire to help and get to know others. In contrast to the view of emotional labour bringing managerial control or adverse affects to service staff, the emotion engendered by this work is authentic expression bringing personal satisfaction

    Growth and development of the western harvest mouse, Reithrodontomys megalotis megalotis

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    Growth rates, gestation period, litter size, reproductive age, sex ratios, and development were studied on 198 litters of Reithrodontomys megalotis megalotis. Growth was characterized by several standard skull and body measurements, and was partitioned into four phases of 1-3, 4-12, 13-22, and 23-70 days. Growth was best described by measurements of tail length, ear length, and dried eye lens weight. Reproductive activity began as early as 38 days for females and 59 days for males. Gestation period was 22 days and mean litter size was 3.83 (range 1-7). Sex ratio was 53.49% males to 46.51% females. Reproductive efficiency was 53.53%. The development of R. m. megalotis was very similar to that of R. m. dychei. Early breeding, post-partum estrous, year-round breeding, high reproductive efficiency, and a short gestation period contribute to a high reproductive potential in R. m. megalotis

    Automating Risk Assessments of Hazardous Material Shipments for Transportation Routes and Mode Selection

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    The METEOR project at Idaho National Laboratory (INL) successfully addresses the difficult problem in risk assessment analyses of combining the results from bounding deterministic simulation results with probabilistic (Monte Carlo) risk assessment techniques. This paper describes a software suite designed to perform sensitivity and cost/benefit analyses on selected transportation routes and vehicles to minimize risk associated with the shipment of hazardous materials. METEOR uses Monte Carlo techniques to estimate the probability of an accidental release of a hazardous substance along a proposed transportation route. A METEOR user selects the mode of transportation, origin and destination points, and charts the route using interactive graphics. Inputs to METEOR (many selections built in) include crash rates for the specific aircraft, soil/rock type and population densities over the proposed route, and bounding limits for potential accident types (velocity, temperature, etc.). New vehicle, materials, and location data are added when available. If the risk estimates are unacceptable, the risks associated with alternate transportation modes or routes can be quickly evaluated and compared. Systematic optimizing methods will provide the user with the route and vehicle selection identified with the lowest risk of hazardous material release. The effects of a selected range of potential accidents such as vehicle impact, fire, fuel explosions, excessive containment pressure, flooding, etc. are evaluated primarily using hydrocodes capable of accurately simulating the material response of critical containment components. Bounding conditions that represent credible accidents (i.e; for an impact event, velocity, orientations, and soil conditions) are used as input parameters to the hydrocode models yielding correlation functions relating accident parameters to component damage. The Monte Carlo algorithms use random number generators to make selections at the various decision points such as; crash, location, etc. For each pass through the routines, when a crash is randomly selected, crash parameters are then used to determine if failure has occurred using either external look up tables, correlations functions from deterministic calculations, or built in data libraries. The effectiveness of the software was recently demonstrated in safety analyses of the transportation of radioisotope systems for the US Dept. of Energy. These methods are readily adaptable to estimating risks associated with a variety of hazardous shipments such as spent nuclear fuel, explosives, and chemicals

    O Efeito da Sinalização de Qualidade no Contexto de Serviços

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    Signaling theory states that signals are firms’ actions that communicate information about the quality of a product. The main purpose of this research is to investigate the effect of signal quality in a service context, through the investigation of the signaling effects of price and responsiveness in a service context. Perceived behavior control, regarded as an individual's perception of the ability to perform a behavior, was proposed as a moderator between signaling variables and perceived quality. Two experimental studies with factorial and inter-subject designs were conducted in order to test the hypotheses formulated from the literature review. Results from both experiments show that signaling quality through price and responsiveness can affect perceived quality. The second experiment supports the hypothesis of perceived behavior control moderation between price as a signaling variable and perceived quality, but not between responsiveness and perceived quality. These results and their implications are discussed in the final section of the paper

    Growth of \u3ci\u3eDipodomys ordii\u3c/i\u3e (Rodentia: Heteromyidae)

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    Growth rates were determined for laboratory-reared Dipodomys ordii pallidus Durrant & Setzer. Instantaneous growth rates were used to express increase of body weight, total length, tail length, ear length and hind foot length as rates between times of measurements and the instantaneous percentage of maximum size. Data were analyzed for growth periods of 1–3, 4–15, 16–29 and 30–70 days. All five parameters provided significant correlations of growth with age during all growth periods. Even though all of the growth parameters correlate with age, these parameters cannot be reliably used to predict age

    The role of emotions on consumers’ satisfaction within the fitness context

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    Previous studies have suggested that consumption-related emotions are important to understand post-purchase reactions. This study examines the relationship between fitness consumers’ emotions and overall satisfaction. After an initial step of free-thought listing and content validity, followed by a pre-test, a survey was conducted among consumers of five different fitness centers (n=786). The questionnaire included measures to assess positive and negative emotions, as well as overall satisfaction with the fitness center. The results gathered through a structural equation model provide evidence that negative emotion experienced by consumers impacts negatively overall satisfaction, while positive emotion have a positive effect on overall satisfaction. These findings suggest managerial implications, such as the need to collect consumers’ perceptions of both tangible and intangible aspects of the services, listen costumers’ opinions in a regular basis, and provide regular training to staff members, in order to identify the triggers of positive emotions and contribute to increased levels of overall satisfaction. Guidelines for future research within the fitness context are also suggested.Estudos precedentes sugerem que as emoções relacionadas com o consumo são importantes para compreender as reações dos consumidores após a compra. Este estudo analisa a relação entre as emoções dos consumidores de fitness e satisfação global. Depois de uma etapa inicial de listagem de pensamento-livre e validade de conteúdo, seguido de um pré-teste, foi realizada uma pesquisa entre os consumidores de cinco centros de fitness diferentes (n = 786). O questionário incluiu medidas para avaliar as emoções positivas e negativas, bem como a satisfação global com o centro de fitness. Os resultados obtidos através de um modelo de equações estruturais forneceram evidências de que as emoções negativas vivenciadas pelos consumidores impactam negativamente a satisfação global, enquanto as emoções positivas têm um efeito positivo sobre a satisfação global. Estes resultados sugerem implicações para os gestores, tais como a necessidade de recolher informação sobre a perceção dos consumidores dos aspetos tangíveis e intangíveis dos serviços, ouvir regularmente as opiniões dos consumidores e facultar formação regular aos colaboradores. Isto permitirá identificar os aspetos que desencadeiam emoções positivas e contribuir para o aumento dos níveis de satisfação global. Orientações para futuras pesquisas no contexto de fitness também são sugeridas.Sin financiación0.185 SJR (2015) Q3, 1090/1779 Medicine (miscellaneous); Q4, 177/229 Health (social science), 112/128 Sports scienceUE

    The search for the ideal biocatalyst

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    While the use of enzymes as biocatalysts to assist in the industrial manufacture of fine chemicals and pharmaceuticals has enormous potential, application is frequently limited by evolution-led catalyst traits. The advent of designer biocatalysts, produced by informed selection and mutation through recombinant DNA technology, enables production of process-compatible enzymes. However, to fully realize the potential of designer enzymes in industrial applications, it will be necessary to tailor catalyst properties so that they are optimal not only for a given reaction but also in the context of the industrial process in which the enzyme is applied

    Consumer Complaints and Company Market Value

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    Consumer complaints affect company market value and common sense suggests that a negative impact is expected. However, do complaints always negatively impact company market value? We hypothesize in this study that complaints may have a non-linear effect on market value. Positive (e.g. avoiding high costs to solve complaints) and negative (e.g. speedy and intense diffusion) tradeoffs may occur given the level of complaints. To test our non-linear hypothesis, a panel data was collected from cell phone service providers from 2005 to 2013. The results supported our tradeoff rationale. Low levels of complaints allow for companies to increase market value, while high levels of complaints cause increasing harm to market value. The sample, model and period considered in this study, indicates a level of 0.49 complaints per thousand consumers as the threshold for a shift in tradeoffs. The effects on market value become increasingly negative when trying to make reductions to move below this level, due to negative tradeoffs

    Customer emotions in service failure and recovery encounters

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    Emotions play a significant role in the workplace, and considerable attention has been given to the study of employee emotions. Customers also play a central function in organizations, but much less is known about customer emotions. This chapter reviews the growing literature on customer emotions in employee–customer interfaces with a focus on service failure and recovery encounters, where emotions are heightened. It highlights emerging themes and key findings, addresses the measurement, modeling, and management of customer emotions, and identifies future research streams. Attention is given to emotional contagion, relationships between affective and cognitive processes, customer anger, customer rage, and individual differences
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