932 resultados para Laboratory stress test
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O objetivo neste trabalho foi estimar as correlações entre o California Mastitis Test (CMT), a contagem células somáticas (CCS) e a produção de leite. Foram colhidas 544 amostras de leite de 38 búfalas em lactação nos anos de 2002 e 2003. O manejo de ordenha consistiu em uma ordenha diária, em que os tetos das búfalas eram desinfectados com solução de iodo, secos individualmente com papel toalha e submetidas à ordenha mecânica. O CMT foi realizado imediatamente após higienização dos tetos e as amostras de leite foram enviadas ao laboratório do DHVSP da Unesp/Botucatu, para realização da Contagem de Células Somáticas, em aparelho eletrônico Somacount 300. Foram efetuadas correlações entre Contagem de Células Somáticas, CMT, produção de leite, proteína, gordura e sólidos totais, que foram analisadas pelo SAEG (1997). A média de células somáticas foi de 63.380 células/mL, a produção diária de leite, de 4,07 ± 1,3 kg e a produção ajustada para os 270 dias, de 1214,25 ± 293,54 kg. Não foram encontradas correlações entre produção de leite, contagem de células somáticas e CMT. Para CCS e CMT, a correlação foi positiva e significativa (r = 0,53).
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Resuspension of the top few sediment layers of tidal mud flats is known to enhance planktonic biomass of microbiota (benthic diatoms and bacteria). This process is mainly controlled by tidal shear stress and cohesiveness of mud, and is also influenced by bioturbation activities. Laboratory experiments in a race track flume were performed to test the interactive effects of these factors on both the critical entrainment and resuspension kinetics of microbiota from silt-clay sediments from the Marennes-Oleron Bay, France. The marine snail Hydrobia ulvae was used to mimic surface bioturbation activities. As expected, the kinetics of microbial resuspension versus shear stress were largely controlled by the cohesiveness of silt-clay sediments. However, our results indicate that the effect of surface tracking by H. ulvae on microbial resuspension was clearly dependent on the interaction between sediment cohesiveness and shear velocity. Evidence was also found that microphytobenthos and bacteria are not simultaneously resuspended from silt-clay bioturbated sediments. This supports the theory that diatoms within the easily eroded mucus matrix behave actively and bacteria adhering to fine silt particles eroded at higher critical shear velocities behave passively.
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The present study employed a cross-sectional design to test a model of coping with acculturative stress in an international student sample. Drawing from Lent’s (2004) social cognitive model of restorative well-being, several direct and mediated paths were hypothesized to predict (negatively) acculturative stress and (positively) life satisfaction. Behavioral acculturation and behavioral enculturation (Kim & Omizo, 2006) were also examined as predictors of coping with acculturative stress among international students. Using a self-report survey, participants’ ratings of acculturative stress, life satisfaction, social support, behavioral acculturation, behavioral enculturation, and coping self-efficacy were assessed. The results revealed that the variables of the model explained 16% of the variance in acculturative stress and 27% of the variance in life satisfaction. A final model, including the use of modification indices, provided good fit to the data. Findings also suggested that coping self-efficacy was a direct predictor of acculturative stress, and that behavioral acculturation and coping self-efficacy were direct predictors of students’ life satisfaction. Limitations, future research, and practical implications are discussed.
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Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.
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Engagement is a useful concept in the profession of nursing as it focuses on the positive dimension of human behaviour and visualizes the work context as a positive situation. Evaluate the stress and engagement levels on Portuguese and Spanish nurses and analyse the factors related to the stress and engagement levels in the two sample groups. Comparative exploratory study in a quantitative paradigm. Sample of 867 nurses (504 Portuguese, 363 Spanish), female 83.6% (78.6% Portugal, 90.6% Spain) and average age of 37. Portuguese (77.2%) and Spanish nurses (39.4%), work on average 40 hours per week. 60.6% and 57.7% of the Spanish and Portuguese respectively exercise their profession for 10 years. Sociodemographic questionnaire, the Pamela Gray-Toft’s Nursing Stress Scale (1981) and Schaufeli & Bakker’s Utrecht Work Engagement Scale (2003) were used. In what concerns Engagement there are statistically signiicant differences in the three dimensions, the p-value of the t-Student test were under 5%, highlighting the Spanish nurses for being more vigorous, dedicated and absorbed by their work: vigour, dedication and absorption. The sample of Portuguese nurses experience higher stress levels although the difference with Spanish nurses isn’t statistically signiicant. There are statistically signiicant differences between Portugal and Spain in “Lack of help from colleagues” and also in the psychological domain in general. The Spanish nurses feel more vigorous, dedicated and absorbed by their work. The Portuguese nurses perceive more psychological stress and mention having less help from colleagues.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.
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Mestrado em Finanças
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Dissertação de Mestrado Integrado em Medicina Veterinária
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Stress serves as an adaptive mechanism and helps organisms to cope with life-threatening situations. However, individual vulnerability to stress and dysregulation of this system may precipitate stress-related disorders such as depression. The neurobiological circuitry in charge of dealing with stressors has been widely studied in animal models. Recently our group has demonstrated a role for lysophosphatidic acid (LPA) through the LPA1 receptor in vulnerability to stress, in particular the lack of this receptor relates to robust decrease of adult hippocampal neurogenesis and induction of anxious and depressive states. Nevertheless, the specific abnormalities in the limbic circuit in reaction to stress remains unclear. The aim of this study is to examine the differences in the brain activation pattern in the presence or absence of LPA1 receptor after acute stress. For this purpose, we have studied the response of maLPA1-null male mice and normal wild type mice to an intense stressor: Tail Suspension Test. Activation induced by behaviour of brain regions involved in mood regulation was analysed by stereological quantification of c-Fos immunoreactive positive cells. We also conducted multidimensional scaling analysis in order to unravel coativation between structures. Our results revealed hyperactivity of stress-related structures such as amygdala and paraventricular nucleus of the hypothalamus in the knockout model and different patterns of coactivation in both genotypes using a multidimensional map. This data provides further evidence to the engagement of the LPA1 receptors in stress regulation and sheds light on different neural pathways under normal and vulnerability conditions that can lead to mood disorders.
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This study evaluated the effect of extract of Aloe vera in the transport water of matrinxã (Brycon amazonicus) fish on stress response and leukocyte respiratory activity. Fish was transported for 4 h in water containing Aloe at levels 0; 0.02; 0.2 and 2 mg/L, and sampled before transport 2, 4, 24 and 96 h after for determination of plasma glucose and respiratory activity of leukocytes. An additional in vitro assay was conducted with another fish species, pacu (Piaractus mesopotamicus), to test the respiratory burst of leukocytes exposed to Aloe extract (0.0, phosphate-buffered saline (PBS) only) at 0.1, 0.2, 0.5 and 1 mg/L). Plasma glucose increased after 2 and 4 h of transport and returned to control levels within 24 h, but the addition of Aloe in the transport water did not affect the level of blood glucose. However, at 2 h of transport, Aloe enhanced the respiratory activity of leukocytes in a dose-dependent way. The highest value of respiratory burst activity of leukocytes was observed in the fish transported in water containing Aloe at 2 mg/L. The enhancing effect of the plant extract on the production of oxygen radicals was confirmed in vitro in leukocytes of pacu incubated in Aloe at concentrations 0.1 and 0.2 mg/L. The results suggest that Aloe vera is a modulator of the immune system in fish improving the innate immune response tested.
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The hopelessness depression (HD) theory assumes a number of contributing factors to the development of hopelessness expectations and HD symptoms. Studies carried out to test HD theory have generally supported the prediction that a negative attributional style contributes to the development of hopelessness expectations and HD symptoms, although the evidence is less consistent for adolescents. Due to these inconsistent results, as well as the assumption advanced by HD theory that other factors aside from attributional style may contribute to the development of HD, in this study we examined the potential role of adolescents’ daily stress and coping styles as contributing factors to HD at these ages, and the effects of gender on these relationships. Seiffge-Krenke (1995) showed that stress in daily life plays a particularly relevant role during adolescence and described three coping styles used by adolescents to face daily stress: active and internal approach-oriented styles, which are considered functional and complementary, and avoidant style, considered dysfunctional. In this study, secondary students (N = 480; aged 13–17) completed the Hopelessness Scale (Beck, Weissman, Lester, & Trexler, 1974), the Hopelessness Depression Symptoms Questionnaire (Metalsky & Joiner, 1997), the Problem Questionnaire ((Seiffge-Krenke, 1995) and the Coping Across Situations Questionnaire (Seiffge-Krenke, 1995). To test the role of daily stress and coping styles in the prediction of hopelessness expectations and HD symptoms, two four-step hierarchical multiple regression analyses were conducted. In these analyses, gender was introduced first, daily stress was introduced second, the three coping styles were entered in a third step, and the moderating effects of gender on the associations of the predictor variables (daily stress and each coping style) with the criterion variables (hopelessness expectations or HD symptoms) were introduced in a fourth step. Results showed a moderating effect of gender on the relationship between daily stress and hopelessness expectations, which revealed a significant effect for boys despite the fact that girls experienced more daily stress than boys, thus suggesting an inoculation effect in girls. It was also found a gender-dependent role of coping styles in the prediction of HD symptoms, revealing a protective effect for the active style in girls and for the internal style in boys. This suggests that girls would benefit from being more action-prone and boys more reflection-prone in order to prevent HD. These findings indicate that programmes aimed to promote coping skills in adolescents would benefit from being gender-adapted.
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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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Advances in the diagnosis of Mycobacterium bovis infection in wildlife hosts may benefit the development of sustainable approaches to the management of bovine tuberculosis in cattle. In the present study, three laboratories from two different countries participated in a validation trial to evaluate the reliability and reproducibility of a real time PCR assay in the detection and quantification of M. bovis from environmental samples. The sample panels consisted of negative badger faeces spiked with a dilution series of M. bovis BCG Pasteur and of field samples of faeces from badgers of unknown infection status taken from badger latrines in areas with high and low incidence of bovine TB (bTB) in cattle. Samples were tested with a previously optimised methodology. The experimental design involved rigorous testing which highlighted a number of potential pitfalls in the analysis of environmental samples using real time PCR. Despite minor variation between operators and laboratories, the validation study demonstrated good concordance between the three laboratories: on the spiked panels, the test showed high levels of agreement in terms of positive/negative detection, with high specificity (100%) and high sensitivity (97%) at levels of 10(5) cells g(-1) and above. Quantitative analysis of the data revealed low variability in recovery of BCG cells between laboratories and operators. On the field samples, the test showed high reproducibility both in terms of positive/negative detection and in the number of cells detected, despite low numbers of samples identified as positive by any laboratory. Use of a parallel PCR inhibition control assay revealed negligible PCR-interfering chemicals co-extracted with the DNA. This is the first example of a multi-laboratory validation of a real time PCR assay for the detection of mycobacteria in environmental samples. Field studies are now required to determine how best to apply the assay for population-level bTB surveillance in wildlife.
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Background and Purpose. This descriptive cohort study investigated a physical therapy program of pelvic-floor neuromuscular electrostimulation (NMES) combined with exercises, with the aim of developing a simple, inexpensive, and conservative treatment for postpartum genuine stress incontinence (GSI). Subjects. Eight female subjects with urodynamically established GSI persisting more than 3 months after delivery participated in the study. The subjects ranged in age from 24 to 37 years (X̅=32, SD=4.2). Methods. This was a descriptive multiple-subject cohort study. Each subject received a total of nine treatment sessions during 3 consecutive weeks, consisting of two 15-minute sessions of NMES followed by a 15-minute pelvic-floor muscle exercise program. Patients also practiced daily pelvic-floor exercises during the 3-week treatment period. The treatment intervention was measured using three separate variables. Maximum muscle contractions (pretraining, during training, and posttraining) were measured indirectly as pressure, using perineometry. Urine loss pretraining and posttraining was measured by means of a Pad test. Self-reported frequency of incontinence was recorded daily throughout the period of the study, using a diary. Data were analyzed using a one-way repeated measures analysis of variance (ANOVA), a Wilcoxon signed-ranks test, and a Friedman two-way ANOVA by ranks. Results. The results indicated that maximum pressure generated by pelvic-floor contractions was greater and both the quantity of urine loss and the frequency of incontinence were lower following the implementation of the physical therapy program. Five subjects became continent, and three others improved. A follow-up survey 1 year later confirmed the consistency of these results. Conclusion and Discussion. The results suggest that the proposed physical therapy program may influence postpartum GSI. Further studies are needed to validate this simple, inexpensive, and conservative physical therapy protocol.