811 resultados para performance levels
Resumo:
Purpose: To determine acrylamide (AA) levels in different brands of commercial and traditional foodstuffs available in Syria by ultra-performance liquid chromatography-mass spectrometery (UPLCMS). Methods: A total of 63 samples were analyzed. Food samples were defatted by hexane and then extracted with methanol 98 % in a vortex mixer. Thereafter, Carrez I and Carrez II were added to precipitate proteins from the co-extractives and then centrifuged to obtain a clear aqueous extract that was evaporated to dryness. The extract was dissolved in 1 mL of water, eluted through a preconditioned Oasis HLB cartridge and then filtered. The filtrate was analyzed by UPLC-MS/MS to determine AA content. Results: Among the commercial foods tested, the highest acrylamide quantity was found in potato products (396 ± 3.59 – 1844 ± 5.29 μg kg−1) and the lowest in corn products (183 ± 2.64 – 366 ± 4.58 μg kg−1). This was followed by biscuits (57 ± 2.64 – 1433 ± 2.51 μg kg−1), breakfast cereals (121 ± 8.73 – 245 ± 3.60 μg kg−1), bread (119 ± 1.73 – 263 ± 3.60 μg kg−1) and then coffee (113 ± 2.64 - 64 ± 3.05 μg kg−1). Regarding traditional foods, the highest level of AA was found in AL- Mshabak (481 ± 2.08 μg kg−1) and AL-Awamat (421 ± 2.64 μg kg−1) followed by AL-Namora (282 ± 4.35 μg kg−1) and AL-Kenafa (242 ± 2.64 μg kg−1). It was also observed that the lowest amount of AA was in fried bread (230 μg kg−1), AL-Fatayer (192 ± 3.51 μg kg−1) and AL-Baqlawa (172 ± 4.35 μg kg−1) while Eid Aqras (130 ± 4.58 μg kg−1) and AL-Brazeq (167 ± 3.78 μg kg−1) contained the least amount of AA. Conclusion: The results indicate that the highest levels of AA are found in the most commonly consumed foods. There was significant difference (p < 0.05) in AA levels among different food items and within different brands of the same product.
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Back-pressure on a diesel engine equipped with an aftertreatment system is a function of the pressure drop across the individual components of the aftertreatment system, typically, a diesel oxidation catalyst (DOC), catalyzed particulate filter (CPF) and selective catalytic reduction (SCR) catalyst. Pressure drop across the CPF is a function of the mass flow rate and the temperature of the exhaust flowing through it as well as the mass of particulate matter (PM) retained in the substrate wall and the cake layer that forms on the substrate wall. Therefore, in order to control the back-pressure on the engine at low levels and to minimize the fuel consumption, it is important to control the PM mass retained in the CPF. Chemical reactions involving the oxidation of PM under passive oxidation and active regeneration conditions can be utilized with computer numerical models in the engine control unit (ECU) to control the pressure drop across the CPF. Hence, understanding and predicting the filtration and oxidation of PM in the CPF and the effect of these processes on the pressure drop across the CPF are necessary for developing control strategies for the aftertreatment system to reduce back-pressure on the engine and in turn fuel consumption particularly from active regeneration. Numerical modeling of CPF's has been proven to reduce development time and the cost of aftertreatment systems used in production as well as to facilitate understanding of the internal processes occurring during different operating conditions that the particulate filter is subjected to. A numerical model of the CPF was developed in this research work which was calibrated to data from passive oxidation and active regeneration experiments in order to determine the kinetic parameters for oxidation of PM and nitrogen oxides along with the model filtration parameters. The research results include the comparison between the model and the experimental data for pressure drop, PM mass retained, filtration efficiencies, CPF outlet gas temperatures and species (NO2) concentrations out of the CPF. Comparisons of PM oxidation reaction rates obtained from the model calibration to the data from the experiments for ULSD, 10 and 20% biodiesel-blended fuels are presented.
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This dissertation comprised of three essays provides justification for the need to pursue research on multinationality and performance with a more fine-grained approach. Essay one is a conceptual response to an article written by Jean-Francois Hennart in 2011 which questions the need and approach toward future research in this domain. I argue that internalization theory does not render multinationality and performance research meaningless and identify key areas where methodological enhancements can be made to strengthen our research findings with regard to Hennart’s call for more content validity. Essay two responds to the need for more-fine grained research on the consequences of multinationality by introducing non-traditional measures of performance such as social and environmental performance and adopting a more theoretically relevant construct of regionalization to capture international diversification levels of the firm. Using data from the world’s largest 600 firms (based on sales) derived from Bloomberg and the Directory of Corporate Affiliates; I employ general estimating equation analysis to account for the auto-correlated nature of the panel data alongside multivariate regression techniques. Results indicate that regionalization has a positive relationship with economic performance while it has a negative relationship with environmental and social performance outcomes, often referred to as the “Triple Bottom-Line” performance. Essay three builds upon the work in the previous essays by linking the aforementioned performance variables and sample to corporate reputation which has been shown to be a beneficial strategic asset. Using Structural Equation Modeling I explore economic, environmental and social signals as mediators on relationship between regionalization and firm reputation. Results indicate that these variables partially mediate a positive relationship between regionalization and firm reputation. While regionalization positively affects the reputation building signal of economic performance, it aids in reputation building by reducing environmental and social disclosure effects which interestingly impact reputation negatively. In conclusion, the dissertation submits opportunities for future research and contributes to research by demonstrating that regionalization affects performance, but the effect varies in accordance with the performance criterion and context. In some cases, regional diversification may produce competing or conflicting outcomes among the potential strategic objectives of the firm.
Resumo:
Career Academy instructors’ technical literacy is vital to the academic success of students. This nonexperimental ex post facto study examined the relationships between the level of technical literacy of instructors in career academies and student academic performance. It was also undertaken to explore the relationship between the pedagogical training of instructors and the academic performance of students. Out of a heterogeneous population of 564 teachers in six targeted schools, 136 teachers (26.0 %) responded to an online survey. The survey was designed to gather demographic and teaching experience data. Each demographic item was linked by researchers to teachers’ technology use in the classroom. Student achievement was measured by student learning gains as assessed by the reading section of the FCAT from the previous to the present school year. Linear and hierarchical regressions were conducted to examine the research questions. To clarify the possibility of teacher gender and teacher race/ethnic group differences by research variable, a series of one-way ANOVAs were conducted. As revealed by the ANOVA results, there were not statistically significant group differences in any of the research variables by teacher gender or teacher race/ethnicity. Greater student learning gains were associated with greater teacher technical expertise integrating computers and technology into the classroom, even after controlling for teacher attitude towards computers. Neither teacher attitude toward technology integration nor years of experience in integrating computers into the curriculum significantly predicted student learning gains in the regression models. Implications for HRD theory, research, and practice suggest that identifying teacher levels of technical literacy may help improve student academic performance by facilitating professional development strategies and new parameters for defining highly qualified instructors with 21st century skills. District professional development programs can benefit by increasing their offerings to include more computer and information communication technology courses. Teacher preparation programs can benefit by including technical literacy as part of their curriculum. State certification requirements could be expanded to include formal surveys to assess teacher use of technology.
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We use an augmented version of the UK Innovation Surveys 4–7 to explore firm-level and local area openness externalities on firms’ innovation performance. We find strong evidence of the value of external knowledge acquisition both through interactive collaboration and non-interactive contacts such as demonstration effects, copying or reverse engineering. Levels of knowledge search activity remain well below the private optimum, however, due perhaps to informational market failures. We also find strong positive externalities of openness resulting from the intensity of local interactive knowledge search—a knowledge diffusion effect. However, there are strong negative externalities resulting from the intensity of local non-interactive knowledge search—a competition effect. Our results provide support for local initiatives to support innovation partnering and counter illegal copying or counterfeiting. We find no significant relationship between either local labour quality or employment composition and innovative outputs.
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Acoustic measurements were performed in eight schools of different levels of education (from kindergarten to college) located in Viseu – Portugal. The acoustic evaluation was made in order to analyze the most common problems that may condition the acoustic environment inside school building. The acoustics evaluation of school buildings was made by the measurement of: reverberation time in classrooms; sound insulation between classrooms and between classrooms and corridors; impact sound insulation of floors and airborne sound insulation of façade. The sound insulation of façade was made with all elements closed and with natural ventilation conditions (banners or windows tilt mode). It was found that most of the studied cases revealed disabled constructive aspects in relation to the acoustic requirements of school buildings compromising the quality of education.
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Background: Preclinical studies have identified certain probiotics as psychobiotics a live microorganisms with a potential mental health benefit. Lactobacillus rhamnosus (JB-1) has been shown to reduce stress-related behaviour, corticosterone release and alter central expression of GABA receptors in an anxious mouse strain. However, it is unclear if this single putative psychobiotic strain has psychotropic activity in humans. Consequently, we aimed to examine if these promising preclinical findings could be translated to healthy human volunteers. Objectives: To determine the impact of L. rhamnosus on stress-related behaviours, physiology, inflammatory response, cognitive performance and brain activity patterns in healthy male participants. An 8 week, randomized, placebo-controlled, cross-over design was employed. Twenty-nine healthy male volunteers participated. Participants completed self-report stress measures, cognitive assessments and resting electroencephalography (EEG). Plasma IL10, IL1β, IL6, IL8 and TNFα levels and whole blood Toll-like 4 (TLR-4) agonist-induced cytokine release were determined by multiplex ELISA. Salivary cortisol was determined by ELISA and subjective stress measures were assessed before, during and after a socially evaluated cold pressor test (SECPT). Results: There was no overall effect of probiotic treatment on measures of mood, anxiety, stress or sleep quality and no significant effect of probiotic over placebo on subjective stress measures, or the HPA response to the SECPT. Visuospatial memory performance, attention switching, rapid visual information processing, emotion recognition and associated EEG measures did not show improvement over placebo. No significant anti-inflammatory effects were seen as assessed by basal and stimulated cytokine levels. Conclusions: L. rhamnosus was not superior to placebo in modifying stress-related measures, HPA response, inflammation or cognitive performance in healthy male participants. These findings highlight the challenges associated with moving promising preclinical studies, conducted in an anxious mouse strain, to healthy human participants. Future interventional studies investigating the effect of this psychobiotic in populations with stress-related disorders are required.
Resumo:
La eliminación de barreras entre países es una consecuencia que llega con la globalización y con los acuerdos de TLC firmados en los últimos años. Esto implica un crecimiento significativo del comercio exterior, lo cual se ve reflejado en un aumento de la complejidad de la cadena de suministro de las empresas. Debido a lo anterior, se hace necesaria la búsqueda de alternativas para obtener altos niveles de productividad y competitividad dentro de las empresas en Colombia, ya que el entorno se ha vuelto cada vez más complejo, saturado de competencia no sólo nacional, sino también internacional. Para mantenerse en una posición competitiva favorable, las compañías deben enfocarse en las actividades que le agregan valor a su negocio, por lo cual una de las alternativas que se están adoptando hoy en día es la tercerización de funciones logísticas a empresas especializadas en el manejo de estos servicios. Tales empresas son los Proveedores de servicios logísticos (LSP), quienes actúan como agentes externos a la organización al gestionar, controlar y proporcionar actividades logísticas en nombre de un contratante. Las actividades realizadas pueden incluir todas o parte de las actividades logísticas, pero como mínimo la gestión y ejecución del transporte y almacenamiento deben estar incluidos (Berglund, 2000). El propósito del documento es analizar el papel de los Operadores Logísticos de Tercer nivel (3PL) como promotores del desempeño organizacional en las empresas colombianas, con el fin de informar a las MIPYMES acerca de los beneficios que se obtienen al trabajar con LSP como un medio para mejorar la posición competitiva del país.
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This research project addresses a central question in the IS business value field: Does IS/IT investments impact positively on firm financial performance? IS/IT investments are seen as having an enormous potential impact on the competitive position of the firm, on its performance, and demand an active and motivated participation of several stakeholder groups. Actual research conducted in the Information Systems field, relating IS/IT investments with firm performance use transactions costs economics and resource-based view of the firm to try to explain and understand that relationship. However, it lacks to stress the importance of stakeholder management, as a moderator variable in that relationship. Stakeholder theory sees the firm as the hub centric to the spokes representing various stakeholders who were in essence equidistant to the firm, and survival and continuing profitability of the corporation depend upon its ability to fulfil its economic and social purpose, which is to create and distribute wealth or value sufficient to ensure that each primary stakeholder group continues as part of the corporation’s stakeholder system. Stakeholder theory in its instrumental version, argues that if a firm pays attention to the stakes of all stakeholder groups (and not just shareholders), it will obtain higher levels of financial performance. With this premise in mind, the aim of this paper is to discuss and test the use of stakeholder theory in the IS business value stream of research, in order to achieve a better understanding of the impact of IS/IT investments on firm performance (moderated by stakeholder management). To achieve the expected impact from an IS/IT investment, it is argued that firms need a strong commitment from those stakeholder groups, which lead us to the need of a corporate “stakeholder orientation”. When firm financial performance is measured by returns on assets (ROA), returns on investments (ROI) and returns on sales (ROS), the results show that “stakeholder orientation” impact positively in the relation between IS/IT and firm performance, using a sample of Portuguese large companies.
Resumo:
Tannins are widespread throughout the plant kingdom, occurring as hydrolysable and condensed tannins and at different levels in several animal feeding sources. Recent years have seen an increasing interest in the use of tannin-rich plants and plant extracts in ruminant diets for improving the quality of their edible products. Some results show that this strategy is effective in improving the fatty acid profile of meat and milk, increasing the level of health-beneficial fatty acids as well as enhancing the oxidative stability of the products. However, the use of tannin-rich feed in animal diets requires great care, due to its possible detrimental effects on animal performance and induction of metabolic disorders. Although promising, the results of studies on the effects of tannins on animal performance and quality of their products are still controversial, probably depending on type and chemical structure of tannins, amount ingested, composition of diet, and species of animal. In this chapter, the current knowledge regarding the effect of dietary tannins on animal performance and the quality of their products (meat and milk), particularly on the fatty acid profile, oxidative stability, and organoleptic properties, is reviewed. The tannin chemistry diversity and its occurrence in ruminant diets, as well as its beneficial and adverse effects on ruminants, will be briefly reviewed, and aspects related to oral cavity physiology, saliva production/composition, and postingestive effects will also be discussed.