929 resultados para Back-analysis


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Background: The pollen grains of Ambrosia spp. are considered to be important aeroallergens. Previous studies have shown that the long-range transport of Ambrosia pollen to Poland is intermittent and mainly related to the passage of air masses over the Carpathian and Sudetes mountains from sources to the south, e.g. the Czech Republic, Slovakia and Hungary. In this study, Ambrosia pollen counts and back-trajectories from specific episodes in 1999 and 2002 have been analysed with the aim of identifying possible new sources of Ambrosia pollen arriving at three sites in Poland. Method: The combination of Ambrosia pollen measurements (daily average and bi-hourly concentrations) and air mass trajectory calculations were used to investigate two Ambrosia pollen episodes recorded at Rzeszow, Krakow and Poznań on the 4th and 5th September 1999 and 3rd September 2002. Ambrosia pollen counts were recorded by volumetric spore traps of the Hirst design. Trajectories were calculated using the transport model within the Lagrangian air pollution model, ACDEP (Atmospheric Chemistry and Deposition). Results: The collective results of pollen measurements and back-trajectory analysis indicate plumes of Ambrosia pollen travelling up through Poland from the southeast during the investigated episodes. In 1999, the plume was first recorded at Rzeszow in Southeastern Poland during the morning of the 4th September. Its route can be followed as it passed Krakow during the afternoon of the 4th, and later on the 4th and 5th September at Poznań. Similarly, back-trajectories calculated during the morning and afternoon from Krakow and Rzeszow on the 3rd September 2002 indicates that the air masses arrived at these sites from the East or Southeast. Conclusion: This study shows the progress of Ambrosia plumes into Poland from the southeast. Ambrosia pollen release occurs mainly during the day and so a midday peak in Ambrosia pollen concentrations may indicate a local source. However, if the plume of Ambrosia pollen tracked along its northwesterly path over Poland during investigated episodes did not originate from inside Poland, then it is likely that it came from the Ukraine. This identifies a possible new source of ragweed pollen for Poland. Trajectory analysis can only show the path along which an air mass travels, not the specific source area. Further investigation could therefore include source based transport models such as 3D Eulerian atmospheric transport models.

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Back injuries identification and diagnoses in the transition of the Taylor model to the flexiblemodel of production organization, demands a parallel intervention of prevention actors at work. This study uses simultaneously three intervention models (structured action analysis, muscle skeletal symptoms questionnaires and muscle skeletal assessment) for work activities in a packaging plant. In this study seventy and two (72) operative workers participated (28 workers with muscle skeletal evaluation). In an intervention period of 10 months, the physical, cognitive, organizational components and productive process dynamics were evaluated from the muscle skeletal demands issues. The differences established between objective exposure at risk, back injury risk perception, appreciation and a vertebral spine evaluation, in prior and post intervention, determines the structure for a muscle skeletal risk management system. This study explains that back injury symptoms can be more efficiently reduced among operative workers combining measures registered and the adjustment between dynamics, the changes at work and efficient gestures development. Relevance: the results of this study can be used to pre ent back injuries in workers of flexible production processes.

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This study aims at quantifying through electromyography the actions of the biceps brachii-BB (long head), tríceps brachii- TB (long head) and deltoideus-DA (clavicular portion) muscles, during the going (G) and return (R) phases in back support exercises. Surface electrodes were placed at the muscles, according to DELAGI (1981). It was used a specific software and a AID plate to take the signals. After being collected, the records were processed resulting in efficient values (RMS), were normalized by maximum isometric contraction (MVIC=100%) and statistically analysed using the Friedman, DSM and Wilcox non-parametric tests. All the muscles presented electromyographic activity of the movements. The triceps brachii was the muscle with higher activity in both phases of the movement. It was concluded that the exercise is indicated for the arm muscle strength development.

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Background: Investigation and discrimination of neuromuscular variables related to the complex aetiology of low back pain could contribute to clarifying the factors associated with symptoms. Objective: Analysing the discriminative power of neuromuscular variables in low back pain. Methods: This study compared muscle endurance, proprioception and isometric trunk assessments between women with low back pain (LBP, n=14) and a control group (CG, n=14). Multivariate analysis of variance and discriminant analysis of the data were performed. Results: The muscle endurance time (s) was shorter in the LBP group than in the CG (p=0.004) with values of 85.81 (37.79) and 134.25 (43.88), respectively. The peak torque (Nm/kg) for trunk extension was 2.48 (0.69) in the LBP group and 3.56 (0.88) in the GG (p=0.001); for trunk flexion, the mean torque was 1.49 (0.40) in the LBP group and 1.85 (0.39) in the CG (p=0.023). The repositioning error (degrees) before the endurance test was 2.66 (1.36) in the LBP group and 2.41 (1.46) in the CG (p=0.664), and after the endurance test, it was 2.95 (1.94) in the LBP group and 2.00 (1.16) in the CG (p=0.06). Furthermore, the variables showed discrimination between the groups (p=0.007), with 78.6% of the individuals with low back pain correctly classified in the LBP group. In turn, variables related to muscle activation showed no difference in discrimination between the groups (p=0.369). Conclusion: Based on these findings, the clinical management of low back pain should consist of both resistance and strength training, particularly in the extensor muscles.

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The occupational exposure limits of different risk factors for development of low back disorders (LBDs) have not yet been established. One of the main problems in setting such guidelines is the limited understanding of how different risk factors for LBDs interact in causing injury, since the nature and mechanism of these disorders are relatively unknown phenomena. Industrial ergonomists' role becomes further complicated because the potential risk factors that may contribute towards the onset of LBDs interact in a complex manner, which makes it difficult to discriminate in detail among the jobs that place workers at high or low risk of LBDs. The purpose of this paper was to develop a comparative study between predictions based on the neural network-based model proposed by Zurada, Karwowski & Marras (1997) and a linear discriminant analysis model, for making predictions about industrial jobs according to their potential risk of low back disorders due to workplace design. The results obtained through applying the discriminant analysis-based model proved that it is as effective as the neural network-based model. Moreover, the discriminant analysis-based model proved to be more advantageous regarding cost and time savings for future data gathering.

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This study aimed to evaluate, ex vivo, the nanoleakage in dentinal tubules, the linear infiltration of silver nitrate in the dentin wall/root-end filling material interface, and the presence of gaps in this interface in root-end cavities filled with 4 filling materials. Forty-eight disto-buccal root canals of maxillary molars were instrumented and filled. Retrograde cavities were prepared with ultrasonic points (apical 2 mm). The samples were divided into 2 control groups (n = 4) and 4 experimental groups (n = 10): Group I white mineral trioxide aggregate (MTA); Group II Super EBA; Group III Portland cement; and Group IV Sealer 26. After 1 week, the specimens were subjected to silver nitrate and prepared for SEM (backscattered electrons). In the apical-apical segment, an area with significantly higher leakage was observed for Super EBA, followed by Portland cement, MTA, and Sealer 26 (P = 0.0054). In the medium and cervical segments, all materials showed the same leakage behavior (P = 0.1815 and P = 0.1723, respectively). The linear infiltration at the dentin wall/root-end filling material interface was higher with Super EBA than the other groups. No differences in the percentage of gaps along the 3 mm of dentin wall/root-end filling material interface between the 4 materials were evident (P > 0.05). Nanoleakage occurred mainly in the apical segment of the samples, and Super EBA showed the highest values. The area and linear leakage were lower in the middle and coronal segments, regardless of the root-end filling material. No material perfectly sealed the root-end cavities, which allowed for the leakage occurrence. Microsc. Res. Tech. 75:796800, 2012. (C) 2011 Wiley Periodicals, Inc.

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OBJECTIVE: To compare costs of function- and pain-centred inpatient treatment in patients with chronic low back pain over 3 years of follow-up. DESIGN: Cost analysis of a randomized controlled trial. PATIENTS: A total of 174 patients with chronic low back pain were randomized to function- or pain-centred inpatient treatment. METHODS: Data on direct and indirect costs were gathered by questionnaires sent to patients, health insurance providers, employers, and the Swiss Disability Insurance Company. RESULTS: There was a non-significant difference in total medical costs after 3 years' follow-up. Total costs were 77,305 Euros in the function-centred inpatient treatment group and 83,085 Euros in the pain-centred inpatient treatment group. Likewise, indirect costs after 3 years from lost work days were non-significantly lower in the function-centred in-patient treatment group (6354 Euros; 95% confidence interval -20,892, 8392) and direct medical costs were non-significantly higher in the function-centred inpatient treatment group (574 Euros; 95% confidence interval -862, 2011). CONCLUSION: The total costs of function-centred and pain-centred inpatient treatment were similar over the whole 3-year follow-up.

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Ahead of the World Cup in Brazil the crucial question for the Swiss national coach is the nomination of the starting eleven central back pair. A fuzzy set Qualitative Comparative Analysis assesses the defensive performances of different Swiss central back pairs during the World Cup campaign (2011 – 2014). This analysis advises Ottmar Hitzfeld to nominate Steve von Bergen and Johan Djourou as the starting eleven central back pair. The alternative with a substantially weaker empirical validity would be Johan Djourou together with Phillippe Senderos. Furthermore, this paper aims to be a step forward in mainstream football analytics. It analyses the undervalued and understudied defense (Anderson and Sally 2012, Statsbomb 2013) by explaining collective defensive performances instead of assessments of individual player or team performances. However, a qualitatively (better defensive metrics) and quantitatively (more games) improved and extended data set would allow for a more sophisticated analysis of collective defensive performances.

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OBJECTIVE: Occupational low back pain (LBP) is considered to be the most expensive form of work disability, with the socioeconomic costs of persistent LBP exceeding the costs of acute and subacute LBP by far. This makes the early identification of patients at risk of developing persistent LBP essential, especially in working populations. The aim of the study was to evaluate both risk factors (for the development of persistent LBP) and protective factors (preventing the development of persistent LBP) in the same cohort. PARTICIPANTS: An inception cohort of 315 patients with acute to subacute or with recurrent LBP was recruited from 14 health practitioners (twelve general practitioners and two physiotherapists) across New Zealand. METHODS: Patients with persistent LBP at six-month follow-up were compared to patients with non-persistent LBP looking at occupational, psychological, biomedical and demographic/lifestyle predictors at baseline using multiple logistic regression analyses. All significant variables from the different domains were combined into a one predictor model. RESULTS: A final two-predictor model with an overall predictive value of 78% included social support at work (OR 0.67; 95%CI 0.45 to 0.99) and somatization (OR 1.08; 95%CI 1.01 to 1.15). CONCLUSIONS: Social support at work should be considered as a resource preventing the development of persistent LBP whereas somatization should be considered as a risk factor for the development of persistent LBP. Further studies are needed to determine if addressing these factors in workplace interventions for patients suffering from acute, subacute or recurrent LBP prevents subsequent development of persistent LBP.

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The March 2015 European Council might not enter history books, but the outcome of an informal ‘mini summit’ between seven EU leaders has the potential to prepare the grounds for a breakthrough in the negotiations between Athens and its lenders. In this post-summit analysis, Janis A. Emmanouilidis argues that the search for a compromise promises to be a cumbersome, time-consuming and nerveracking exercise. But a solution now seems possible, proving all those doomsayers who have been predicting a ‘Grexit’ or ‘Graccident’ wrong. On other topics, EU leaders committed their countries to build an Energy Union, although questions remain about whether member states will agree to cede sovereignty on a number of significant points. This analysis looks also at the economic issues dealt with at the Spring Summit, with a focus on the perspectives for the European Semester and the Juncker Investment Plan. It ends with a summary of decisions taken on a number of other topics, including relations with Russia and Ukraine, the upcoming Eastern Partnership summit, developments in Libya and in Tunisia, and the endorsement of the Council’s new Secretary General.

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Skates (Rajidae) have been commercially exploited in Europe for hundreds of years with some species’ abundances declining dramatically during the twentieth century. In 2009 it became “prohibited for EU vessels to target, retain, tranship or land” certain species in some ICES areas, including the critically endangered common skate and the endangered white skate. To examine compliance with skate bans the official UK landings data for 2011–2014 were analysed. Surprisingly, it was found that after the ban prohibited species were still reported landed in UK ports, including 9.6 t of common skate during 2011–2014. The majority of reported landings of common and white skate were from northern UK waters and landed into northern UK ports. Although past landings could not be validated as being actual prohibited species, the landings’ patterns found reflect known abundance distributions that suggest actual landings were made, rather than sporadic occurrence across ports that would be evident if landings were solely due to systematic misidentification or data entry errors. Nevertheless, misreporting and data entry errors could not be discounted as factors contributing to the recorded landings of prohibited species. These findings raise questions about the efficacy of current systems to police skate landings to ensure prohibited species remain protected. By identifying UK ports with the highest apparent landings of prohibited species and those still landing species grouped as'skates and rays’, these results may aid authorities in allocating limited resources more effectively to reduce landings, misreporting and data errors of prohibited species, and increase species-specific landing compliance.

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Skates (Rajidae) have been commercially exploited in Europe for hundreds of years with some species’ abundances declining dramatically during the twentieth century. In 2009 it became “prohibited for EU vessels to target, retain, tranship or land” certain species in some ICES areas, including the critically endangered common skate and the endangered white skate. To examine compliance with skate bans the official UK landings data for 2011–2014 were analysed. Surprisingly, it was found that after the ban prohibited species were still reported landed in UK ports, including 9.6 t of common skate during 2011–2014. The majority of reported landings of common and white skate were from northern UK waters and landed into northern UK ports. Although past landings could not be validated as being actual prohibited species, the landings’ patterns found reflect known abundance distributions that suggest actual landings were made, rather than sporadic occurrence across ports that would be evident if landings were solely due to systematic misidentification or data entry errors. Nevertheless, misreporting and data entry errors could not be discounted as factors contributing to the recorded landings of prohibited species. These findings raise questions about the efficacy of current systems to police skate landings to ensure prohibited species remain protected. By identifying UK ports with the highest apparent landings of prohibited species and those still landing species grouped as'skates and rays’, these results may aid authorities in allocating limited resources more effectively to reduce landings, misreporting and data errors of prohibited species, and increase species-specific landing compliance.