909 resultados para Level of analysis
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Individual-level constructs are seldom taken into consideration in construction management research relating to project performance. This is antithetical to the objectives of properly conceptualizing and contextualizing the research we do because many project performance outcomes, such as the extent of cooperation and level of communication or teamwork are influenced and moderated by individuals’ perceptions, values and behaviour. A brief review of the literature in organizational studies centred on culture, identity, empowerment and trust is offered. These constructs are then explored in relation to project performance issues and outcomes, and it is noted that they are predominantly studied at the project and industry levels. We argue that focusing these constructs at the individual unit of analysis has significant implications for project performance and therefore their effects need to be systematically accounted for in explanations of the success and failure of projects. Far from being prescriptive, the aim is to generate interest and awareness for more focused research at the individual level of analysis in order to add new insights and perspectives to critical performance questions in construction management. To this end, a research agenda is outlined, arguing that construction management research integrating individual-level constructs and broader, macro-contextual issues will help define and enhance the legitimacy of the field.
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Presentation
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This research used resource allocation theory to generate predictions regarding dynamic relationships between self-efficacy and task performance from 2 levels of analysis and specificity. Participants were given multiple trials of practice on an air traffic control task. Measures of task-specific self-efficacy and performance were taken at repeated intervals. The authors used multilevel analysis to demonstrate differential and dynamic effects. As predicted, task-specific self-efficacy was negatively associated with task performance at the within-person level. On the other hand, average levels of task-specific self-efficacy were positively related to performance at the between-persons level and mediated the effect of general self-efficacy. The key findings from this research relate to dynamic effects - these results show that self-efficacy effects can change over time, but it depends on the level of analysis and specificity at which self-efficacy is conceptualized. These novel findings emphasize the importance of conceptualizing self-efficacy within a multilevel and multispecificity framework and make a significant contribution to understanding the way this construct relates to task performance.
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Proteomic approaches have been useful for the identification of aberrantly expressed proteins in complex diseases such as cancer. These proteins are not only potential disease biomarkers, but also targets for therapy. The aim of this study was to identify differentially expressed proteins in diffuse astrocytoma grade II, anaplastic astrocytoma grade III and glioblastoma multiforme grade IV in human tumor samples and in non-neoplastic brain tissue as control using 2-DE and MS. Tumor and control brain tissue dissection was guided by histological hematoxylin/eosin tissue sections to provide more than 90% of tumor cells and astrocytes. Six proteins were detected as up-regulated in higher grade astrocytomas and the most important finding was nucleophosmin (NPM) (p < 0.05), whereas four proteins were down-regulated, among them raf kinase inhibitor protein (RKIP) (p < 0.05). We report here for the first time the alteration of NPM and RKIP expression in brain cancer. Our focus on these proteins was due to the fact that they are involved in the PI3K/AKT/mTOR and RAS/RAF/MAPK pathways, known for their contribution to the development and progression of gliomas. The proteomic data for NPM and RKIP were confirmed by Western blot, quantitative real-time PCR and immunohistochemistry. Due to the participation of NPM and RKIP in uncontrolled proliferation and evasion of apoptosis, these proteins are likely targets for drug development.
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The purpose of this thesis is to investigate how far the education level of the second or third generation of publicly traded German family firms affects the post-succession firm performance. By conducting a correlational and regression design, the aim is to examine how several variables influence the performance of family firms. Performance measures, for example ROA and Tobin’s q and variables, like Education level and succession periods, examine analytically that a positive succession trend will occur. However, with the used model, only a less rigid model shows empirical evidence.
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This paper contributes to the existing literature on industrial location by discussing some issues regarding the territorial levels that have been used in location analysis. We analyse which could be the advantages and disadvantages of performing locational analysis at a different local levels. We use data for new manufacturing firms located at municipality, county and travel to work areas level. We show that location determinants vary according to the territorial level used in the analysis, so we conclude that the level at which we perform the investigation should be carefully selected. Keywords: industrial location, cities, agglomeration economies, count data models.
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UNLABELLED: The relationship between bone quantitative ultrasound (QUS) and fracture risk was estimated in an individual level data meta-analysis of 9 prospective studies of 46,124 individuals and 3018 incident fractures. Low QUS is associated with an increase in fracture risk, including hip fracture. The association with osteoporotic fracture decreases with time. INTRODUCTION: The aim of this meta-analysis was to investigate the association between parameters of QUS and risk of fracture. METHODS: In an individual-level analysis, we studied participants in nine prospective cohorts from Asia, Europe and North America. Heel broadband ultrasonic attenuation (BUA dB/MHz) and speed of sound (SOS m/s) were measured at baseline. Fractures during follow-up were collected by self-report and in some cohorts confirmed by radiography. An extension of Poisson regression was used to examine the gradient of risk (GR, hazard ratio per 1 SD decrease) between QUS and fracture risk adjusted for age and time since baseline in each cohort. Interactions between QUS and age and time since baseline were explored. RESULTS: Baseline measurements were available in 46,124 men and women, mean age 70 years (range 20-100). Three thousand and eighteen osteoporotic fractures (787 hip fractures) occurred during follow-up of 214,000 person-years. The summary GR for osteoporotic fracture was similar for both BUA (1.45, 95 % confidence intervals (CI) 1.40-1.51) and SOS (1.42, 95 % CI 1.36-1.47). For hip fracture, the respective GRs were 1.69 (95 % CI, 1.56-1.82) and 1.60 (95 % CI, 1.48-1.72). However, the GR was significantly higher for both fracture outcomes at lower baseline BUA and SOS (p < 0.001). The predictive value of QUS was the same for men and women and for all ages (p > 0.20), but the predictive value of both BUA and SOS for osteoporotic fracture decreased with time (p = 0.018 and p = 0.010, respectively). For example, the GR of BUA for osteoporotic fracture, adjusted for age, was 1.51 (95 % CI 1.42-1.61) at 1 year after baseline, but at 5 years, it was 1.36 (95 % CI 1.27-1.46). CONCLUSIONS: Our results confirm that quantitative ultrasound is an independent predictor of fracture for men and women particularly at low QUS values.
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Objectives: To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents. Design: Individual patient data meta-analysis of randomised controlled trials. Cox proportional regression models stratified by trial, containing random effects, were used to assess the impact of stent type on outcomes. Hazard ratios with 95% confidence interval for outcomes were reported. Data sources and study selection: Medline, Embase, the Cochrane Central Register of Controlled Trials. Randomised controlled trials that compared cobalt-chromium everolimus eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients. Primary outcomes: The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite or probable stent thrombosis, target vessel revascularisation, and all cause death. Results: The search yielded five randomised controlled trials, comprising 4896 participants. Compared with patients receiving bare metal stents, participants receiving cobalt-chromium everolimus eluting stents had a significant reduction of cardiac mortality (hazard ratio 0.67, 95% confidence interval 0.49 to 0.91; P=0.01), myocardial infarction (0.71, 0.55 to 0.92; P=0.01), definite stent thrombosis (0.41, 0.22 to 0.76; P=0.005), definite or probable stent thrombosis (0.48, 0.31 to 0.73; P<0.001), and target vessel revascularisation (0.29, 0.20 to 0.41; P<0.001) at a median follow-up of 720 days. There was no significant difference in all cause death between groups (0.83, 0.65 to 1.06; P=0.14). Findings remained unchanged at multivariable regression after adjustment for the acuity of clinical syndrome (for instance, acute coronary syndrome v stable coronary artery disease), diabetes mellitus, female sex, use of glycoprotein IIb/IIIa inhibitors, and up to one year v longer duration treatment with dual antiplatelets. Conclusions: This meta-analysis offers evidence that compared with bare metal stents the use of cobalt-chromium everolimus eluting stents improves global cardiovascular outcomes including cardiac survival, myocardial infarction, and overall stent thrombosis.
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Objectives: To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents. Design: Individual patient data meta-analysis of randomised controlled trials. Cox proportional regression models stratified by trial, containing random effects, were used to assess the impact of stent type on outcomes. Hazard ratios with 95% confidence interval for outcomes were reported. Data sources and study selection: Medline, Embase, the Cochrane Central Register of Controlled Trials. Randomised controlled trials that compared cobalt-chromium everolimus eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients. Primary outcomes: The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite or probable stent thrombosis, target vessel revascularisation, and all cause death. Results: The search yielded five randomised controlled trials, comprising 4896 participants. Compared with patients receiving bare metal stents, participants receiving cobalt-chromium everolimus eluting stents had a significant reduction of cardiac mortality (hazard ratio 0.67, 95% confidence interval 0.49 to 0.91; P=0.01), myocardial infarction (0.71, 0.55 to 0.92; P=0.01), definite stent thrombosis (0.41, 0.22 to 0.76; P=0.005), definite or probable stent thrombosis (0.48, 0.31 to 0.73; P<0.001), and target vessel revascularisation (0.29, 0.20 to 0.41; P<0.001) at a median follow-up of 720 days. There was no significant difference in all cause death between groups (0.83, 0.65 to 1.06; P=0.14). Findings remained unchanged at multivariable regression after adjustment for the acuity of clinical syndrome (for instance, acute coronary syndrome v stable coronary artery disease), diabetes mellitus, female sex, use of glycoprotein IIb/IIIa inhibitors, and up to one year v longer duration treatment with dual antiplatelets. Conclusions: This meta-analysis offers evidence that compared with bare metal stents the use of cobalt-chromium everolimus eluting stents improves global cardiovascular outcomes including cardiac survival, myocardial infarction, and overall stent thrombosis.
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Purpose: This study evaluated the influence of distal extension removable partial denture associated with implant in cases of different bone level of abutment tooth, using 2D finite element analysis.Materials and Methods: Eight hemiarch models were simulated: model A-presenting tooth 33 and distal extension removable partial denture replacing others teeth, using distal rest connection and no bone lost; model B-similar to model A but presenting distal guide plate connection; model C-similar to model A but presenting osseointegrated implant with ERA retention system associated under prosthetic base; model D-similar to model B but presenting osseointegrated implant as described in model C; models E, F, G, and H were similar to models A, B, C, and D but presenting reduced periodontal support around tooth 33. Using ANSYS 9.0 software, the models were loaded vertically with 50 N on each cusp tip. For results, von Mises Stress Maps were plotted.Results: Maximum stress value was encountered in model G (201.023 MPa). Stress distribution was concentrated on implant and retention system. The implant/removable partial denture association decreases stress levels on alveolar mucosa for all models.Conclusions: Use of implant and ERA system decreased stress concentrations on supporting structures in all models. Use of distal guide plate decreased stress levels on abutment tooth and cortical and trabecular bone. Tooth apex of models with reduced periodontal support presented increased stress when using distal rest. (Implant Dent 2011;20:192-201)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Introduction: The effects of lead on children’s health have been widely studied. Aim: To analyze the correlation between the long latency auditory evoked potential N2 and cognitive P3 with the level of lead poisoning in Brazilian children. Methods: This retrospective study evaluated 20 children ranging in age from 7 to 14 years at the time of audiological and electrophysiological evaluations. We performed periodic surveys of the lead concentration in the blood and basic audiological evaluations. Furthermore, we studied the auditory evoked potential long latency N2 and cognitive P3 by analyzing the absolute latency of the N2 and P3 potentials and the P3 amplitude recorded at Cz. At the time of audiological and electrophysiological evaluations, the average concentration of lead in the blood was less than 10 ug/dL. Results: In conventional audiologic evaluations, all children had hearing thresholds below 20 dBHL for the frequencies tested and normal tympanometry findings; the auditory evoked potential long latency N2 and cognitive P3 were present in 95% of children. No significant correlations were found between the blood lead concentration and latency (p = 0.821) or amplitude (p = 0.411) of the P3 potential. However, the latency of the N2 potential increased with the concentration of lead in the blood, with a significant correlation (p = 0.030). Conclusion: Among Brazilian children with low lead exposure, a significant correlation was found between blood lead levels and the average latency of the auditory evoked potential long latency N2; however, a significant correlation was not observed for the amplitude and latency of the cognitive potential P3
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This study sought to assess the impact of the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score (SXscore) on clinical outcomes in patients undergoing percutaneous coronary intervention.
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BACKGROUND The safety and efficacy of drug-eluting stents (DES) in the treatment of coronary artery disease have been assessed in several randomised trials. However, none of these trials were powered to assess the safety and efficacy of DES in women because only a small proportion of recruited participants were women. We therefore investigated the safety and efficacy of DES in female patients during long-term follow-up. METHODS We pooled patient-level data for female participants from 26 randomised trials of DES and analysed outcomes according to stent type (bare-metal stents, early-generation DES, and newer-generation DES). The primary safety endpoint was a composite of death or myocardial infarction. The secondary safety endpoint was definite or probable stent thrombosis. The primary efficacy endpoint was target-lesion revascularisation. Analysis was by intention to treat. FINDINGS Of 43,904 patients recruited in 26 trials of DES, 11,557 (26·3%) were women (mean age 67·1 years [SD 10·6]). 1108 (9·6%) women received bare-metal stents, 4171 (36·1%) early-generation DES, and 6278 (54·3%) newer-generation DES. At 3 years, estimated cumulative incidence of the composite of death or myocardial infarction occurred in 132 (12·8%) women in the bare-metal stent group, 421 (10·9%) in the early-generation DES group, and 496 (9·2%) in the newer-generation DES group (p=0·001). Definite or probable stent thrombosis occurred in 13 (1·3%), 79 (2·1%), and 66 (1·1%) women in the bare-metal stent, early-generation DES, and newer-generation DES groups, respectively (p=0·01). The use of DES was associated with a significant reduction in the 3 year rates of target-lesion revascularisation (197 [18·6%] women in the bare-metal stent group, 294 [7·8%] in the early-generation DES group, and 330 [6·3%] in the newer-generation DES group, p<0·0001). Results did not change after adjustment for baseline characteristics in the multivariable analysis. INTERPRETATION The use of DES in women is more effective and safe than is use of bare-metal stents during long-term follow-up. Newer-generation DES are associated with an improved safety profile compared with early-generation DES, and should therefore be thought of as the standard of care for percutaneous coronary revascularisation in women. FUNDING Women in Innovation Initiative of the Society of Cardiovascular Angiography and Interventions.