903 resultados para hours of work
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Thermal and fatigue cracking are the major pavement distresses that contribute to a drastic reduction of the pavement’s service life and performance in Ontario. Chemical oxidation and hardening of asphalt binders deteriorates its physical properties since physical properties of asphalts depend on its chemical composition. This thesis is aimed to establish a relationship between physical and chemical properties of asphalt binders. A secondary objective is to show the strong correlation between CTOD and temperature. All recovered and straight Ministry of Transportation of Ontario (MTO) samples were investigated using conventional Superpave® test method dynamic shear rheometer (DSR) as well as improved MTO test methods such as extended bending beam rheometer (eBBR) and double-edge-notched tension (DENT) test. DENT test was conducted for all Ontario contract samples at three different temperatures based on their performance grade after three hours of thermal conditioning and compared the results in terms of essential work of fracture, plastic work of fracture and CTOD at different temperatures. Good correlation exists between CTOD and temperature according to the DENT data. X-ray fluorescence (XRF) analysis was conducted to detect the presence of heavy metals such as zinc and molybdenum believed to have originated from waste engine oil. Fourier transform infra-red spectroscopy (FTIR) was performed to determine the abundance of functional groups such as carbonyl, sulfoxides, polyisobutylene, etc. XRF and FTIR analysis confirmed that most of the samples contain waste engine oil and/or oxidized residues, which is believed to be a root cause of premature pavement failures.
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This paper presents the "state of the art" and some of the main issues discussed in relation to the topic of transnational migration and reproductive work in southern Europe. We start doing a genealogy of the complex theoretical development leading to the consolidation of the research program, linking consideration of gender with transnational migration and transformation of work and ways of survival, thus making the production aspects as reproductive, in a context of globalization. The analysis of the process of multiscale reconfiguration of social reproduction and care, with particular attention to its present global dimension is presented, pointing to the turning point of this line of research that would have taken place with the beginning of this century, with the rise notions such as "global care chains" (Hochschild, 2001), or "care drain" (Ehrenreich and Hochschild, 2013). Also, the role of this new agency, now composed in many cases women who migrate to other countries or continents, precisely to address these reproductive activities, is recognized. Finally, reference is made to some of the new conceptual and theoretical developments in this area.
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Nowadays, despite anti-discrimination policies, women suffer frequently from a lack of consideration from their male colleagues, altering their well-being and motivation to work. More precisely, perceived personal or groupal discrimination, could have a distinct influence on work motivation. Previous studies showed that the impact on women varies in function of the type of perceived discrimination (Bourguignon et al. 2006). Based on the self-categorization and the social identity theory, work motivation is differently structured as if employees categorized themselves as individuals or as part of a group. As a result, a different impact from personal and group discrimination on work motivation is expected. Moreover, it has been proved that typical men behavior is heavily associated with competence compared to women behavior (Marchand, Saint-Charles & Corbeil, 2007). Therefore, it is hypothesized that women with more masculine traits will suffer from less perceived discrimination, and work motivation. An online survey was created in order to collect data over work motivation, perceived personal and group discrimination. The respondents were also questioned on typical men and women behavior to determine their gender-conformity. To test our hypotheses, data were collected from 57 women stemming from the labour force, aged from 21 to 63 years old. Results indicate that perceived personal discrimination was negatively related to work motivation and that perceived group discrimination was negatively correlated with masculine behavior. Thereby, our study enhances the importance of work environment, and especially discrimination, on work motivation. This research also corroborates the self-categorization and the social identity theory framework to study these issues.
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The BL Lac object 1ES 1011+496 was discovered at Very High Energy (VHE, E>100GeV) γ-rays by MAGIC in spring 2007. Before that the source was little studied in different wavelengths. Therefore a multi-wavelength (MWL) campaign was organized in spring 2008. Along MAGIC, the MWL campaign included the Mets¨ahovi radio observatory, Bell and KVA optical telescopes and the Swift and AGILE satellites. MAGIC observations span from March to May, 2008 for a total of 27.9 hours, of which 19.4 hours remained after quality cuts. The light curve showed no significant variability yielding an integral flux above 200 GeV of (1.3 ± 0.3) × 10^(−11) photons cm^(−2) s^( −1) . The differential VHE spectrum could be described with a power-law function with a spectral index of 3.3 ± 0.4. Both results were similar to those obtained during the discovery. Swift XRT observations revealed an X-ray flare, characterized by a harder-when-brighter trend, as is typical for high synchrotron peak BL Lac objects (HBL). Strong optical variability was found during the campaign, but no conclusion on the connection between the optical and VHE γ-ray bands could be drawn. The contemporaneous SED shows a synchrotron dominated source, unlike concluded in previous work based on non-simultaneous data, and is well described by a standard one–zone synchrotron self–Compton model. We also performed a study on the source classification. While the optical and X-ray data taken during our campaign show typical characteristics of an HBL, we suggest, based on archival data, that 1ES 1011+496 is actually a borderline case between intermediate and high synchrotron peak frequency BL Lac objects.
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Study objective: To examine the relationship between work stress, as indicated by the job strain model and the effort-reward imbalance model, and smoking. Setting: Ten municipalities and 21 hospitals in Finland. Design and Participants: Binary logistic regression models for the prevalence of smoking were related to survey responses of 37 309 female and 8881 male Finnish public sector employees aged 17-65. Separate multinomial logistic regression models were calculated for smoking intensity for 8130 smokers. In addition, binary logistic regression models for ex-smoking were fitted among 16 277 former and current smokers. In all analyses, adjustments were made for age, basic education, occupational status, type of employment and marital status. Main results: Respondents with high effort-reward imbalance or lower rewards were more likely to be smokers. Among smokers, an increased likelihood of higher intensity of smoking was associated with higher job strain and higher effort-reward imbalance and their components such as low job control and low rewards. Smoking intensity was also higher in active jobs in women, in passive jobs and among employees with low effort expenditure. Among former and current smokers, high job strain, high effort-reward imbalance and high job demands were associated with a higher likelihood of being a current smoker. Lower effort was associated with a higher likelihood of ex-smoking. Conclusions: This evidence suggests an association between work stress and smoking and implies that smoking cessation programs may benefit from the taking into account the modification of stressful features of work environment. Key words: effort-reward imbalance; job strain; smoking. Abbreviations: OR, odds ratio; CI, confidence interval; SES, socioeconomic status
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The objective of this study was to determine the importance of different dimensions as the possible causes for the abandonment of the practice of swimming by former Costa Rican swimmers. Subjects: 51 former swimmers participated, including 17 men (22 ±3.4 years of age) and 34 women (22.5 ±3.4 years of age) from different Costa Rican swimming teams. The Questionnaire of Reasons for Attrition in the Practice of Sports (Gould et al, 1982; cited by Salguero, Tuero, and Márquez, 2003) was used. Results: A positive relationship was noted between perceptions of low skill and low performance (r: 0.372), while negative relationships were noted between years of practice and low skill (r:-0.337), years of practice and influence from others (r:-0.286), and years of practice and starting age for swimming (r:-0.622). A significant interaction was found in the dimensions gender of participants (F: 2.952; p<0.05) and starting age for swimming (F: 3.147; p<0.01). An interaction was also found between dimensions and the desire to swim again (F: 2.485; p>0.05). There were also significant differences in the years of practice; that is, subjects who started before the age of 10 had a higher average of years of practice than those who started later (F: 21.465; p<0.05). Additionally, a significant interaction was found in weekly hours of swimming practice (F: 2.072; p<0.05). There were no significant differences (F: 2.535; p>0.05) according to weekly hours of training when subjects were actively swimming. Conclusions: Possible reasons for dropping out were lack of enjoyment and poor physical condition for men and perception of lack of team spirit for women. The group that started after the age of ten gives similar importance to all the dimensions as possible reasons for dropping out, while the group that began swimming before the age of ten sees lack of team spirit, lack of enjoyment, and poor physical condition as the key reasons for dropping out. The most important dimensions that represented the reasons for abandonment in subjects who wanted to swim again were lack of team spirit, poor physical condition and low skill, while lack of enjoyment was the most important reason for subjects who do not want to swim again. In the group of subjects who would swim less than six hours, lack of team spirit is the most important cause, while the dimension lack of enjoyment was the most important reason for subjects who would swim 6 to 12 hours. Additionally, the highest dropout percentages were observed in the transition from secondary school to college.
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Este estudo avaliou o efeito da restrição alimentar e realimentação na reprodução de fêmeas e no crescimento inicial e sobrevivência de larvas de matrinxã, Brycon amazonicus. Matrizes distribuídas em 8 viveiros (15 peixes/tanque) foram alimentadas diariamente (em 4 tanques - G1) e alimentados em ciclos de 3 dias de alimentação seguidos de 2 dias de restrição (em 4 tanques - G2) por 6 meses antes da desova. Na indução à desova, 57% das fêmeas no G1 e 45% no G2 desovaram. Os pesos médios dos oócitos foram 208,1 g (G1) e 131,6 g (G2), sendo os oócitos G2 menores (1,017 ± 0,003 mm) que os oócitos de G1 (1,048 ± 0,002 mm). As taxas de fertilização (71,9 ± 12,6% e 61,2 ± 13,7%) e de eclosão (61,3 ± 33,9% e 67,5 ± 23,4%) entre os G1 e G2 não diferiram. Larvas foram coletadas na eclosão e às 24, 48 e 72 horas de incubação para medida do crescimento e as restantes transferidas para aquários e amostradas 1, 5, 9 e 15 dias depois. Na transferência, as larvas G1 e G2 tinham pesos similares (1,5 ± 0,15 e 1,46 ± 0,07 mg), mas o comprimento das larvas G2 era maior (6,2 ± 0,13 e 6,7 ± 0,14 mm). Ao 9° dia, quando é recomendada a transferência dos juvenis para tanques externos, os juvenis G2 tinham peso (13,6 ± 0,26 e 18,9 ± 0,07 mg) e comprimento (11,8 ± 0,09 e 14,5 ± 0,04 mm) maiores, mas no 15º dia os juvenis G1 eram maiores em peso (90,2 ± 1,19 e 68,6 ± 0,77 mg) e comprimento (18,8 ± 0,16 e 18,5 ± 0,04 mm). Aos 15 dias, a prole das fêmeas submetidas à restrição alimentar apresentou sobrevivência mais alta que a prole das fêmeas alimentadas diariamente (24,7 ± 2,07% e 19,2 ± 1,91%). A restrição alimentar imposta às fêmeas de matrinxã, apesar de reduzir o número de fêmeas que desovaram e a quantidade de oócitos extrusados, não afetou a fertilização e eclosão das larvas e melhorou a sobrevivência final das larvas.
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The Mine Improvement and New Emergency Response (MINER) Act of 2006 implemented new regulations in the underground coal mining industry that allow for the certification of non-compressed gas equipment for respiratory protection in underground coal mines. NASA’s Kennedy Space Center (KSC) Biomedical Research and Engineering Laboratory (BRL) is investigating the potential to expand cryogenic air supply systems into the mining and general industries. These investigations have, so far, resulted in four separate comparison and hardware development programs. The Propellant Handlers Ensemble (PHE) and Level “A” Ensemble Comparison (LAE): This study compared worker thermal stress while using the industry standard Level A hazardous material handling ensemble as opposed to using the similarly protective Propellant Handler’s Ensemble (PHE) that utilizes a cryogenic air supply pack, known as an Environmental Control Unit (ECU) as opposed to the compressed air Self Contained Breathing Apparatus (SCBA) used in the LAE. The research found that, in a 102°F environment, test subjects experienced significantly decreased body temperature increases, significantly decreased heart rate increases, and decreased sweat loss while performing a standard work routine while using the PHE, compared to the same test subjects performing the same routine while using the LAE. The Cryogenic Refuge Alternative Supply System (CryoRASS) project: The MINER Act of 2006 requires the operators of underground coal mines to provide refuge alternatives that can provide a safe atmosphere for workers for up to 96 hours in the event of a mine emergency. The CryoRASS project retrofitted an existing refuge chamber with a liquid air supply instead of the standard compressed air supply system and performed a 96 hour test. The CryoRASS system demonstrated that it provided a larger air supply in a significantly smaller footprint area, provided humidity and temperature control, and maintained acceptable oxygen and carbon dioxide levels in the chamber for the required amount of time. SCBA and Mine Rescue System (CryoBA/CryoASFS) Another requirement of the MINER Act is that additional emergency breathing equipment must be staged along evacuation routes to supplement the Self Contained/Self Rescue (SCSR) devices that are now required. The BRL has developed an SCBA known as the Cryogenic Breathing Apparatus (CryoBA), that has the ability to provide 2 hours of breathing air, a refill capability, and some cooling for the user. Cryogenic Air Storage and Filling Stations (CryoASFS) would be positioned in critical areas to extend evacuation time. The CryoASFS stations have a significantly smaller footprint and larger air storage capacity to similar compressed air systems. The CryoBA pack is currently undergoing NIOSH certification testing. Technical challenges associated with liquid breathing air systems: Research done by the BRL has also addressed three major technical challenges involved with the widespread use of liquid breathing air. The BRL developed a storage Dewar fitted with a Cryorefrigerator that has stored liquid air for four months with no appreciable oxygen enrichment due to differential evaporation. Testing of liquid breathing air was material and time intensive. A BRL contract developed a system that only required 1 liter of air and five minutes of time compared to the 10 liters of air and 75 minutes of time required by the old method. The BRL also developed a simple and cost effective method of manufacturing liquid air that joins a liquid oxygen tanker with a liquid nitrogen tanker through an orifice controlled “Y” fitting, mixing the two components, and depositing the mixed breathing air in a separate tanker.
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The present study tested a nomological net of work engagement that was derived from its extant research. Two of the main work engagement models that have been presented and empirically tested in the literature, the JD-R model and Kahn’s model, were integrated to test the effects that job features and personal characteristics can have on work engagement through the psychological conditions of meaningfulness, safety, and availability. In this study, safety refers to psychological perceptions of safety and not workplace safety behaviors. The job features that were tested in this model included person-job fit, autonomy, co-worker relations, supervisor support, procedural justice, and interactional justice, while the personal characteristics consisted of self-consciousness, self-efficacy, extraversion, and neuroticism. Thirty-four hypotheses and a conceptual model were tested in order to establish the viability of this nomological net of work engagement in which it was expected that meaningfulness would mediate the relationships between job features and work engagement, safety would mediate the relationships that job features and personal characteristics have with work engagement, and availability (physical, emotional, and cognitive resources) would mediate the relationships that personal characteristics have with work engagement. Furthermore, analyses were run in order to determine the factor structure of work engagement, assess whether or not it exhibits differential validity from organizational commitment and job satisfaction, and confirm that it is positively related to the outcome variable of organizational citizenship behavior (OCB). The final sample consisted of 500 workers from an online labor market who responded to a questionnaire composed of measures of all constructs included in this study. Findings show that work engagement is best represented as a three-factor construct, composed of vigor, dedication and absorption. Furthermore, support was found for the distinction of work engagement from the related constructs of organizational commitment and job satisfaction. With regard to the proposed model, meaningfulness proved to be the strongest predictor of work engagement. Results show that it partially mediates the relationships that all job features have with work engagement. Safety proved to be a partial mediator of the relationships that autonomy, co-worker relations, supervisor support, procedural justice, interactional justice, and self-efficacy have with work engagement, and fully mediate the relationship between neuroticism and work engagement. Findings also show that availability partially mediates the positive relationships that extraversion and self-efficacy have with work engagement, and fully mediates the negative relationship that neuroticism has with work engagement. Finally, a positive relationship was found between work engagement and OCB. Research and organizational implications are discussed.
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This dissertation presents a comparative study of three factories in Cork Harbour area, Sunbeam Wolsey (1927-90), Irish Steel (1939-2001) and the Ford Marina Plant (1917-84). All three factories were significant industrial employers in both a domestic (Irish) and a local (Cork) context and are broadly representative of the Irish manufacturing industry that was developed under the policies of tariff protection introduced in the 1930s and gradually phased out between the late 1950s and the mid-1980s. Sunbeam Wolsey was a textile and clothing concern located on the north side of Cork City that possessed a borderline monopoly within its economic sector and was among the largest private employers of female labour in twentieth century Ireland. Irish Steel was the country’s only steel mill, located on Haulbowline island, a brief ferry-ride from the seaside town of Cobh, and was unusual in being one of the few manufacturing concerns operated as a nationalised industry under the auspices of the state. The Ford Marina plant predated the introduction of protectionism by more than a decade and began as the centre of the Ford empire’s tractor manufacturing business, before switching to the production of private motor vehicles for the Irish market in 1932. All three industries were closed or sold off when the state withdrew support, either in the form of tariff protection (Ford, Sunbeam) or direct funding (Irish Steel). While devoting much attention to the three firms, the central concern of this dissertation is not the companies themselves (though the economic history portion of the dissertation is substantial), but the workers they employed, examining the lives of these individuals both as members of the Irish working class, and, more specifically, as employees of the three factories under consideration. The project can be best described as a comparative factory study, comparing and contrasting the three workforces, focusing primarily on industrial relation and the experience of work. This dissertation utilises both documentary evidence and a significant quantity of oral testimony, breaking new ground by making the workplace the central focus of its investigation. The principal aims of the study are: 1. To document the lives of those who worked in these factories, capturing through oral testimony their subjective experiences of social class and factory life, as well as differences among narrators in terms of gender and status. In achieving this aim, the study will provide a broader social context for its detailed analysis of work and industrial relations in each firm. 2. To analyse the three workplaces and determine how and why each developed such distinct systems of industrial relations at the factory level, as well as to compare and contrast these systems. 3. To examine the nature of work in each factory and to determine how work and industrial relations in each firm developed over time, relating these changes both to internal and external factors. Additionally, the project will provide a comparative analysis of these changes.
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This dissertation, comprised of three separate studies, focuses on the relationship between remote work adoption and employee job performance, analyzing employee social isolation and job concentration as the main mediators of this relationship. It also examines the impact of concern about COVID-19 and emotional stability as moderators of these relationships. Using a survey-based method in an emergency homeworking context, the first study found that social isolation had a negative effect on remote work productivity and satisfaction, and that COVID-19 concerns affected this relationship differently for individuals with high and low levels of concern. The second study, a diary study analyzing hybrid workers, found a positive correlation between work from home (WFH) adoption and job performance through social isolation and job concentration, with emotional stability serving respectively as a buffer and booster in the relationships between WFH and the mediators. The third study, even in this case a diary study of hybrid workers, confirmed the benefits of work from home on job performance and the importance of job concentration as a mediator, while suggesting that social isolation may not be significant when studying employee job performance, but it is relevant for employee well-being. Although each study provides autonomously a discussion and research and practical implications, this dissertation also presents a general discussion on remote work and its psychological implications, highlighting areas for future research
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Fingolimod is a new and efficient treatment for multiple sclerosis (MS). The drug administration requires special attention to the first dose, since cardiovascular adverse events can be observed during the initial six hours of fingolimod ingestion. The present study consisted of a review of cardiovascular data on 180 patients with MS receiving the first dose of fingolimod. The rate of bradycardia in these patients was higher than that observed in clinical trials with very strict inclusion criteria for patients. There were less than 10% of cases requiring special attention, but no fatal cases. All but one patient continued the treatment after this initial dose. This is the first report on real-life administration of fingolimod to Brazilian patients with MS, and one of the few studies with these characteristics in the world.
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Chlorophenylpiperazines (CPP) are psychotropic drugs used in nightclub parties and are frequently used in a state of sleep deprivation, a condition which can potentiate the effects of psychoactive drugs. This study aimed to investigate the effects of sleep deprivation and sleep rebound (RB) on anxiety-like measures in mCPP-treated mice using the open field test. We first optimized our procedure by performing dose-effect curves and examining different pretreatment times in naïve male Swiss mice. Subsequently, a separate cohort of mice underwent paradoxical sleep deprivation (PSD) for 24 or 48h. In the last experiment, immediately after the 24h-PSD period, mice received an injection of saline or mCPP, but their general activity was quantified in the open field only after the RB period (24 or 48h). The dose of 5mgmL(-1) of mCPP was the most effective at decreasing rearing behavior, with peak effects 15min after injection. PSD decreased locomotion and rearing behaviors, thereby inhibiting a further impairment induced by mCPP. Plasma concentrations of mCPP were significantly higher in PSD 48h animals compared to the non-PSD control group. Twenty-four hours of RB combined with mCPP administration produced a slight reduction in locomotion. Our results show that mCPP was able to significantly change the behavior of naïve, PSD, and RB mice. When combined with sleep deprivation, there was a higher availability of drug in plasma levels. Taken together, our results suggest that sleep loss can enhance the behavioral effects of the potent psychoactive drug, mCPP, even after a period of rebound sleep.
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to assess how nurses perceive autonomy, control over the environment, the professional relationship between nurses and physicians and the organizational support and correlate them with burnout, satisfaction at work, quality of work and the intention to quit work in primary healthcare. cross-sectional and correlation study, using a sample of 198 nurses. The tools used were the Nursing Work Index Revised, Maslach Burnout Inventory and a form to characterize the nurses. To analyze the data, descriptive statistics were applied and Spearman's correlation coefficient was used. the nurses assessed that the environment is partially favorable for: autonomy, professional relationship and organizational support and that the control over this environment is limited. Significant correlations were evidenced between the Nursing Work Index Revised, Maslach Burnout Inventory and the variables: satisfaction at work, quality of care and the intent to quit the job. the nurses' perceptions regarding the environment of practice are correlated with burnout, satisfaction at work, quality of care and the intent to quit the job. This study provides support for the restructuring of work processes in the primary health care environment and for communication among the health service management, human resources and occupational health areas.
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Species identification is an essential step in the progress and completion of work in several areas of biological knowledge, but it is not a simple process. Due to the close phylogenetic relationship of certain species, morphological characters are not always sufficiently distinguishable. As a result, it is necessary to combine several methods of analysis that contribute to a distinct categorization of taxa. This study aimed to raise diagnostic characters, both morphological and molecular, for the correct identification of species of the genus Chrysomya (Diptera: Calliphoridae) recorded in the New World, which has continuously generated discussion about its taxonomic position over the last century. A clear example of this situation was the first record of Chrysomya rufifacies in Brazilian territory in 2012. However, the morphological polymorphism and genetic variability of Chrysomya albiceps studied here show that both species (C. rufifacies and C. albiceps) share very similar character states, leading to misidentification and subsequent registration error of species present in our territory. This conclusion is demonstrated by the authors, based on a review of the material deposited in major scientific collections in Brazil and subsequent molecular and phylogenetic analysis of these samples. Additionally, we have proposed a new taxonomic key to separate the species of Chrysomya found on the American continent, taking into account a larger number of characters beyond those available in current literature.