872 resultados para Economic growth Effects of differentials in remuneration Mathematical models
Resumo:
Statins are widely recognized as hypolipemic drugs, but some studies have observed anti-inflammatory and immunomodulatory effects, known as pleiotropic. The aims of this work was to study possible anti-inflammatory effects of simvastatin in abdominal sepsis. Serum pro-inflammatory cytokines and leukocytes count were determined in an experimental model of abdominal sepsis, using cecal ligation and puncture (CLP) in rats. Methods: Twenty eigth Wistar rats weighing 285±12g were randomly divided in: CLP/Sinvastatin rats (n=7), treated with 10 mg/Kg of oral simvastatin 18 and 2 hs berofe CLP; CLP/Saline group rats (n=7), treated with oral saline; group Sham/Simvastatin (n=7), treated with simvastatin, and group Sham/Saline (n=7), treated with saline. Serum TNF-α, IL-1β and IL-6 by ELISA and total leukocytes, neutrophils, lymphocytes, and eosinophils were determined 24 hs after CLP. ANOVA and Tukey test were used considering significant p<0.05. Results: It was demonstrated that serum TNF-α, IL-1β and IL-6 were respectively 364,8±42pg/mL; 46,3±18pg/mL and 28,4±13pg/mL in CLP/Sinvastatin rats, significantly lower (p<0.05) than in group CLP/Saline (778,5±86pg/ml; 176,9±46pg/ ml; 133,6±21 pg/ml, respectively). The same results were observed in total leukocytes and neutrophils counts. Conclusion: These results clearly demonstrate that simvastatin is an effective agent that reduces cytokines levels and leukocyte count in sepsis, independently of its well-known lipid-lowering effects. Thus, HMG-CoA reductase inhibitors like simvastatin have important anti-inflammatory effects in abdominal sepsis in rats
Resumo:
As the number of fungal pathogen outbreaks become more frequent worldwide across taxa, so have the number of species extirpations and communities persisting with the pathogen. This phenomenon raises questions, such as: “what leads to host extinction during an outbreak?” and “how are hosts persisting once the pathogen establishes?.” But the data on host populations and communities across life stages before and after pathogen arrival rarely exist to answer these questions. Over the past three to four decades, the amphibian-killing fungus Batrachochytrim dendrobatidis (Bd) spread in a wave-like manner across Central America, leading to rapid species extirpations and population declines. I collected data on tadpole and adult amphibians in El Copé, Panama before, during, and after the Bd outbreak to answer these questions. I used Bayesian statistical approaches to account for imperfect host and pathogen detection of marked and unmarked individuals. In the tadpole community, within 11 months of Bds arrival, density and occupancy rapidly declined. Species losses were phylogenetically correlated, with glass frogs disappearing first, and tree frogs and poison-dart frogs remaining. I found that tadpole communities resembled one another more strongly after the outbreak than they did before Bd invasion. I found no tadpoles within 22 months of the outbreak and limited signs of recovery within 10 years. In contrast, at the same site, for a population of male glass frogs, Espadarana prosopleon, I found that 10 years post-outbreak, the population was consistently half its historic abundance, and that the lack of recruits to the population explained why the population had not rebounded, rather than high pathogen-induced mortality. And finally, examining the entire amphibian community, I found high pathogen prevalence, low infection intensities, and high survival rates of uninfected and infected hosts. Bd transmission risk, i.e., the probability a susceptible host becomes infected, did not relate to host density, pathogen prevalence, or infection intensity– Bd transmission risk was uniform across the study area. My results are especially relevant to conservation biologists aiming to predict the future impacts of Bd outbreaks, those trying to manage persisting populations, and those interested in reintroducing species back into wild amphibian communities.
Resumo:
The focus of this study is an in-service training program rooted in routines-based early intervention and designed to improve the quality of goals and objectives on individualized plans. Participants were local intervention team members and other professionals who worked closely with each team. This training program involved a small number of trainees per group, providing multiple learning experiences across time and various opportunities for self-assessment and monitoring. We investigated (a) the perceptions of the participants about the strengths and weaknesses of the training program, (b) medium-term outcomes of the training with a comparison group, (c) and variables associated with the quality of goals and objectives. This study involved training more than 200 professionals, and results support the effectiveness of the program in improving the quality of goals and objectives, showing the importance of the routines-based interview in producing that improvement.
Resumo:
Aims. Cocaine addiction is a chronically relapsing disorder characterized by the compulsion to seek and take the drug. Previous investigations have demonstrated that several drugs of abuse, as cocaine, can alter the levels of lipid-based signalling molecules such as the N-acylethanolamines (NAEs). In addition, NAEs levels in the brain are sensitive to cocaine self-administration and extinction training. In this context, this study aimed to investigate the effect of repeated and acute palmitoylethanolamide (PEA), an endogenous NAE, on the behavioural effects of cocaine using mouse models of conditioned reward and psychomotor activation. Methods. Using male C57BL/6J mice, the ability of repeated PEA injections (1 or 10 mg/kg i.p) to modulate the development of a conditioned place preference (CPP) and behavioural sensitization (BS) induced by cocaine (20 mg/kg i.p.) was evaluated. In addition, the expression of cocaine-induced CPP and BS after acute PEA administration was also studied. Results. PEA (1 and 10 mg/kg i.p) significantly reduced the development of cocaine-induced BS, but did not modify the acquisition of cocaine-induced CPP. Furthermore, both doses of PEA were able to reduce the expression of BS and CPP. Conclusions. Altogether, these findings show that exogenous administration of PEA attenuated psychomotor activation and impaired the expression of CPP induced by cocaine. Our results may be relevant in order to understand the role of NAEs in the development and treatment of cocaine addiction.
Resumo:
Purpose: To assess the effects of oral glutamate intake on acute motor effects and chronic intake of ethanol in rodents. Methods: The acute effects of ethanol on motor function were studied in ICR mice by giving 2 or 6 g/kg of ethanol 2 h after distilled water or 2.5 g/kg glutamate per os. Thirty minutes after ethanol treatment, behavioral assays, including rotarod tests and foot print analysis were monitored. In chronic ethanol treatment, male Wistar rats were trained to consume ethanol-sucrose solution during a 2-h period daily, starting with 2 % ethanol/10 % sucrose and gradually increasing to 10 % ethanol/5 % sucrose solution over 56 days. After training session, the drug treatment phase was done for 10 days. The animals were force-fed 50 mg/kg/day topiramate or 2.5 g/kg/day glutamate 2 h before ethanol treatment sessions. Each day, ethanol intake, water intake, food intake and body weight were recorded. Results: Mice that received 2 or 6 g/kg of ethanol orally, showed a significant reduction in time on the rod in the rotarod test and a significant increase in both forelimb and hindlimb stride lengths when compared to control. Oral treatment with 2.5 g/kg of glutamate reversed the acute motor effects of ethanol. In chronic ethanol treatment, the intake of 10 % ethanol/5 % sucrose, accessible for 2 h, was significantly decreased in rats treated with either topiramate or glutamate. Conclusion: These results provide evidence that oral glutamate administration help to reduce the acute motor effects of ethanol in mice and ethanol intake in the chronic ethanol drinking rats.
Resumo:
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.
Resumo:
In attempting to impeach eyewitnesses, attorney's often highlight inconsistencies in the eyewitness's recall. This study examined the differential impact of types of inconsistent testimony on mock-juror decisions. Each of 100 community members and 200 undergraduates viewed one of four versions of a videotaped trial in which the primary evidence against the defendant was the testimony of the eyewitness. I manipulated the types of inconsistent statements given by the eyewitness in the four versions: (1) consistent testimony, (2) information given on-the-stand but not given during the pre-trial investigation, (3) contradictions between on-the-stand and pre-trial statements, and (4) contradictions made on the witness stand. Subjects exposed to any form of inconsistent testimony were less likely to convict and found the defendant less culpable and the eyewitness less effective. These effects were larger for contradictions than for information given on the stand but not during pre-trial investigations.
Resumo:
This study explored the effects on speech intelligibility of across-formant differences in fundamental frequency (ΔF0) and F0 contour. Sentence-length speech analogues were presented dichotically (left=F1+F3; right=F2), either alone or—because competition usually reveals grouping cues most clearly—accompanied in the left ear by a competitor for F2 (F2C) that listeners must reject to optimize recognition. F2C was created by inverting the F2 frequency contour. In experiment 1, all left-ear formants shared the same constant F0 and ΔF0F2 was 0 or ±4 semitones. In experiment 2, all left-ear formants shared the natural F0 contour and that for F2 was natural, constant, exaggerated, or inverted. Adding F2C lowered keyword scores, presumably because of informational masking. The results for experiment 1 were complicated by effects associated with the direction of ΔF0F2; this problem was avoided in experiment 2 because all four F0 contours had the same geometric mean frequency. When the target formants were presented alone, scores were relatively high and did not depend on the F0F2 contour. F2C impact was greater when F2 had a different F0 contour from the other formants. This effect was a direct consequence of the associated ΔF0; the F0F2 contour per se did not influence competitor impact.
Resumo:
2016
Resumo:
Random effect models have been widely applied in many fields of research. However, models with uncertain design matrices for random effects have been little investigated before. In some applications with such problems, an expectation method has been used for simplicity. This method does not include the extra information of uncertainty in the design matrix is not included. The closed solution for this problem is generally difficult to attain. We therefore propose an two-step algorithm for estimating the parameters, especially the variance components in the model. The implementation is based on Monte Carlo approximation and a Newton-Raphson-based EM algorithm. As an example, a simulated genetics dataset was analyzed. The results showed that the proportion of the total variance explained by the random effects was accurately estimated, which was highly underestimated by the expectation method. By introducing heuristic search and optimization methods, the algorithm can possibly be developed to infer the 'model-based' best design matrix and the corresponding best estimates.
Resumo:
A pre-test, post-test, quasi-experimental design was used to examine the effects of student-centered and traditional models of reading instruction on outcomes of literal comprehension and critical thinking skills. The sample for this study consisted of 101 adult students enrolled in a high-level developmental reading course at a large, urban community college in the Southeastern United States. The experimental group consisted of 48 students, and the control group consisted of 53 students. Students in the experimental group were limited in the time spent reading a course text of basic skills, with instructors using supplemental materials such as poems, news articles, and novels. Discussions, the reading-writing connection, and student choice in material selection were also part of the student-centered curriculum. Students in the control group relied heavily on a course text and vocabulary text for reading material, with great focus placed on basic skills. Activities consisted primarily of multiple-choice questioning and quizzes. The instrument used to collect pre-test data was Descriptive Tests of Language Skills in Reading Comprehension; post-test data were taken from the Florida College Basic Skills Exit Test. A MANCOVA was used as the statistical method to determine if either model of instruction led to significantly higher gains in literal comprehension skills or critical thinking skills. A paired samples t-test was also used to compare pre-test and post-test means. The results of the MANCOVA indicated no significant difference between instructional models on scores of literal comprehension and critical thinking. Neither was there any significant difference in scores between subgroups of age (under 25 and 25 and older) and language background (native English speaker and second-language learner). The results of the t-test indicated, however, that students taught under both instructional models made significant gains in on both literal comprehension and critical thinking skills from pre-test to post-test.
Resumo:
The ability of four operational weather forecast models [ECMWF, Action de Recherche Petite Echelle Grande Echelle model (ARPEGE), Regional Atmospheric Climate Model (RACMO), and Met Office] to generate a cloud at the right location and time (the cloud frequency of occurrence) is assessed in the present paper using a two-year time series of observations collected by profiling ground-based active remote sensors (cloud radar and lidar) located at three different sites in western Europe (Cabauw. Netherlands; Chilbolton, United Kingdom; and Palaiseau, France). Particular attention is given to potential biases that may arise from instrumentation differences (especially sensitivity) from one site to another and intermittent sampling. In a second step the statistical properties of the cloud variables involved in most advanced cloud schemes of numerical weather forecast models (ice water content and cloud fraction) are characterized and compared with their counterparts in the models. The two years of observations are first considered as a whole in order to evaluate the accuracy of the statistical representation of the cloud variables in each model. It is shown that all models tend to produce too many high-level clouds, with too-high cloud fraction and ice water content. The midlevel and low-level cloud occurrence is also generally overestimated, with too-low cloud fraction but a correct ice water content. The dataset is then divided into seasons to evaluate the potential of the models to generate different cloud situations in response to different large-scale forcings. Strong variations in cloud occurrence are found in the observations from one season to the same season the following year as well as in the seasonal cycle. Overall, the model biases observed using the whole dataset are still found at seasonal scale, but the models generally manage to well reproduce the observed seasonal variations in cloud occurrence. Overall, models do not generate the same cloud fraction distributions and these distributions do not agree with the observations. Another general conclusion is that the use of continuous ground-based radar and lidar observations is definitely a powerful tool for evaluating model cloud schemes and for a responsive assessment of the benefit achieved by changing or tuning a model cloud