INTRODUÇÃO: Treinamento muscular inspiratório (TMI) tem se mostrado capaz de aumentar a espessura diafragmática. Sabe-se que o diafragma crural age como um esfincter externo do esfíncter inferior do esôfago (EIE), mas é desconhecido se pacientes com hipotonia do EIE se beneficiariam do TMI, a fim de aumentarem a pressão respiratória média (PRM), consequentemente havendo melhora dos sintomas de refluxo gastroesofágico. OBJETIVO: Determinar o resultado dos efeitos do TMI nas pressões respiratória média nos pacientes com doença do refluxo gastroesofágico e seu efeito no tônus do esfíncter inferior do esôfago e compará-los com o grupo controle. MÉTODOS: Vinte pacientes foram incluídos no grupo caso e nove no grupo controle. Todos pacientes tinham a pressão expiratória máxima (PEM) entre cinco e 10mmHg e foram submetidos à manometria esofágica e teste de função pulmonar antes e após oito semanas de treinamento utilizando o threshold IMT (Respironics, Cedar Grove, NJ) duas vezes ao dia. A medida da pressão inspiratória máxima (Pimax) foi aferida a cada duas semanas. O grupo caso teve o threshold IMT ajustado progressivamente, a cada quinze dias, sempre a 30% da nova Pimax. O grupo controle realizou o treinamento com o mesmo aparelho, sob uma pressão constante de 7cmH2O. O nível de significância estatística foi estabelecido a 5% (p £ 0,05). RESULTADOS: A média de idade do grupo caso foi 50,1 ± 18 e no grupo controle de 51,3± 11 anos. Após oito semanas de treinamento utilizando o threshold IMT houve uma melhora na PRM em 15 (75%) pacientes, representando um ganho médio de 46,6% (p<0,01), enquanto no grupo controle, seis (66%) pacientes obtiveram um aumento médio de 26,2% (p<0,01). Não houve diferença estatisticamente significante entre os grupos (p= 0,507). A PEM também aumentou quando comparada com a inicial (p<0,01), mas não diferiu entre os grupos (p= 0,727). Observou-se uma melhora na Pimax no grupo 1 (40% versus 19,6%). Houve um aumento na pressão expiratória máxima (Pemax) em ambos os grupos após as oito semanas de IMT (p< 0,05). CONCLUSÕES: O treinamento muscular inspiratório aumentou as pressões respiratória média e expiratória máxima ao longo das oito semanas em ambos os grupos. Não houve diferença com significância estatística entre os grupos sugerindo que o aumento na pressão do esfíncter inferior do esôfago ocorre independentemente da resistência aplicada ao threshold IMT. Mais estudos são necessários para determinar o impacto clínico desse aumento pressórico e confirmar ou afastar a manutenção dessas pressões a longo prazo / INTRODUCTION: Inspiratory muscle training (IMT) has been shown to increase diaphragm thickness. It is known that the diaphragmatic crural fibers act as an external LES, but it is unknown if patients with hypotensive lower esophageal sphincter (LES) would benefit from IMT increasing the mid-respiratory pressure (MRP), and as such relieving gastroesophageal reflux symptoms. AIM: Evaluate the effect of inspiratory muscle training on MRP in patients with gastroesophageal reflux disease and hypotensive LES and compare it with the control group. PATIENTS AND METHODS: Twenty consecutive patients (progressive loading group) and 9 controls (sham group) were included. All of them had end expiratory pressure (EEP) between 5 and 10mmHg and underwent esophageal manometry and pulmonary function tests before and after 8 weeks of training using a threshold IMT (Respironics, Cedar Grove, NJ) twice daily. The maximal inspiratory pressure (Pimax) measurement was repeated each 2 weeks. The progressive loading group had their threshold IMT set at 30% of their new Pimax. Sham-treated patients (same device but minimal resistance to the air flow) had their threshold set at 7cmH2O and it was maintained constant during the period. The significance level was set at 5% (p £ 0.05). RESULTS: The mean age of progressive loading group was 50.1 ± 11.3 years and sham group was 51.3± 6.3. Following eight weeks of training using a threshold IMT there was an increase in MRP in 15 (75%) patients, representing an average gain of 46.6% (p<0.01), while in the sham group, six (66%) patients had their MRP raised with mean increase of 26.2% (p< 0.01). There was no significant difference between the groups (p= 0.507). EEP also increased when compared with before measured (p<0.01), but did not differ between groups (p= 0.727). It has also been observed an improvement in the Pimax in progressive loading group (40% versus 19.6%). It was observed a gain in the maximal expiratory pressure (Pemax) as well in both groups after the 8-week program of IMT (p< 0.05). CONCLUSION: Inspiratory muscle training increased MRP and EEP in patients of active and sham-treated group after an 8-week program. There was no significant statistical difference between groups suggesting that the increase in pressure at LES occurs regardless to the resistance loading of threshold IMT. Extended follow-up is necessary to document the long-term benefits of such improvements

Abstract This research on military aviation noise was conducted because the personnel working with military aircraft were concerned about noise induced hearing damage. In addition, comprehensive data on hearing impairments and occupational exposure of military pilots in the Finnish Air Force was not available. Moreover, data on the effects of overflight noise of military jets was necessary for the evaluation of noise induced hearing deteriorations of members of the public who might be exposured accidentally for the low-level jets' overflights. The averaged noise exposure levels of pilots varied during a flight from 97 dB(A) to 106 dB(A) in the cockpit and from 83 dB(A) to 100 dB(A) at the entrance of the ear canal. Radio noise was 4–10 dB higher than background noise inside the helmet. The attenuation provided by air crew helmets varied from10 to 21 dB(A) in the laboratory, and was at the same level during real flights. The attenuation measured in the laboratory and in working conditions was about 30 dB(A) for earmuffs. An active noise cancellation (ANC) device decreased averaged noise exposure (LAeq8min) 4–8 dB over the noise attenuation of the same helmets when the ANC system was off. The noise of overflights by military jets were measured and the noise levels were lower than those known to cause the permanent threshold shifts. However, noise induced hearing damages might be possible in certain conditions. In order to assess the hearing loss risk of pilots, hearing thresholds were measured before and after one flight using both conventional and extended high frequency (EHF) audiometry. Minor temporary threshold shifts (TTS) were revealed. The risk of noise-induced damage at the studied exposure levels is, in all probability, rather small. A novel NoiseScan data management system proved to be an interesting tool in assessment of the risk of developing hearing impairment on the basis of known risk factors. Due to the small number of risk factors, the hearing of pilots was shown to be at considerably less risk than that of industrial workers in Finland.

Every living creature meets with pain up to these days. Many researches are made in labour conditions, we try to find out how the pain works and how we can suppress it or how we can utilize it in our welfare. Our work is focused on the effect of aging, season, acclimatization and ambient temperature on thermal and mechanic pain threshold in laboratory rats. We were interested how these factors affect the results of the research. Adult male Wistar rats were used in all experiments. Thermal pain thresholds were measured by withdrawal reaction of three body sites: forelimbs, hind limbs and tail. Mechanic pain thresholds were measured by von Frey filaments and a skin temperature was measured by IR thermometer, both of three body sites. Our results demonstrate that : (i) aging have effect on nociceptive pain threshold; (ii) there is presence of cranio-caudal distribution of nociceptive sensitivity in aging and in changing of ambient temperature - forelimbs have lower latency than hind limbs; (iii) thermal pain threshold depends indirectly on ambient and skin temperature; (iv) there was no effect of repeated measurement on nociceptive thresholds of the three body sites; (v) hind limbs and tails are more sensitive to changes of ambient temperature than forepaws; (vi) mechanic pain threshold not change...

A sensitivity analysis was performed on the transit signal priority (TSP) requesting threshold to evaluate its impact on bus performance and general traffic. Two distinct bus routes were evaluated to determine the optimal requesting threshold that would balance the positive impacts on bus performance with the negative impacts on general traffic. Route 217, a conventional bus route, and the Utah Valley Express (UVX), a bus rapid transit line, utilize a dedicated short-range communication (DSRC)-based TSP system as part of their normal, day-to-day operations. Using field-generated data exclusively, bus performance and general traffic were evaluated over a 7-month period from February through August 2019. Bus performance was evaluated through on-time performance (OTP), schedule deviation, travel time, and dwell time, while the traffic analysis was performed by evaluating split failure, change in green time, and the frequency at which TSP was served. The requesting thresholds evaluated for Route 217 were 5-, 3-, 2-, and 0-minutes, which stipulate how far behind schedule the bus must be in order to request TSP. For UVX, 5-minutes and 2-minutes, as well as ON and OFF scenarios were evaluated; ON meant the buses were always requesting regardless of how late they were, while OFF meant that no requests were made and operations would be as if there were no TSP at all. A combination of observational and statistical analyses concluded with convincing evidence that OTP, schedule deviation, and travel time improve as the requesting threshold approaches zero with negligible impacts to general traffic. For Route 217, as the requesting threshold changed from 3, to 2, to 0 minutes, OTP increased 2.0 and 2.5 percent, respectively, mean schedule deviation improved 15.9 and 20.9 seconds, respectively, and travel time decreased at 72 percent of timepoints. Meanwhile, negative impacts to traffic occurred if an increase in split failure was measured after TSP was served, a phenomenon observed a maximum of once every 43 minutes. For UVX, as the requesting threshold changed from 5, to 2 minutes, to ON, OTP increased 7.6 and 4.7 percent, respectively, mean schedule deviation improved 24.3 and 15.0 seconds, respectively, and travel time decreased between 72 percent of timepoints. Thus, it is concluded that under the TSP system as implemented, bus performance improves as the requesting threshold approaches zero with inconsequential impacts to general traffic.

One of today’s financial trends is securitization. Evaluating Securitization risk requires some strong quantitative skills and a deep understanding of both credit and market risk. For international securitization programs it is mandatory to take into account the exchange-rates-related risks. We will see the di˙erent methods to evaluate extreme variations of the exchange rates using the Extreme Value Theory and Monte Carlo simulations. / Värdepapperisering är en av dagens finansiella trender. Att utvärdera vär-depapperisering risk kräver starka kvantitativa kunskaper och en förståelseför både kredit- och marknadsrisk. För internationell värdepapperisering ärdet obligatoriskt att hänsyn tas till valutarisker. Vi kommer att se de olika metoder för att utvärdera extrema variationer i valutakurser med hjälp av extremvärdesteori och Monte Carlo-simuleringar.

With the high development of economic and demand for city research, an issue of detecting city boundaries plays an extremely important role in urbanization that promotes the progress of human civilization. Some critical applications such as land use, urban planning and city sprawl have been constantly discussed, which rely on the acquisition of city areas. For the better acquisition of city areas, choosing a proper method to capture city boundaries becomes significant where it greatly improves the value of city study. Although conventional data can be used to define the city boundaries, some drawbacks still exist when measuring the city boundaries in a global scale. Remote sensing (RS) data of nightlight imagery (2010) by Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS) acquired from National oceanic and atmospheric administration's National Geoscience Data Center (NOAA/NOGA) is applied to extract the city boundaries in fifty countries, of which these countries are chosen followed by the Gross Domestic Product that are ranked in top 50. In this case, the data distribution of nightlight imagery followed by heavy-tailed distribution. Head/tail break algorithm poses a possibility of calculating reasonable threshold and extracting the natural cities with the help of software based on the Geomatics information system (GIS). An extended study of power law is made by using of power law estimator from previous studies to check whether the extracted natural cities can match the power law distribution. Result shows that combination of the nightlight imagery data and the head/tail break is capable of extracting the city boundaries and a set of possible thresholds with visual inspection by using the head/tail break are executed. There is only one country, namely Belgium, cannot be processed due to its data properties. Result also address how well the natural cities of the fifty countries can be extracted in terms of visual inspection, among the chosen cities, 33 of countries boundaries can be better matched and 13 countries can fundamentally match the city boundaries. Meanwhile, an extended study of power law is provided and four countries have to be found that do not follow the power law distribution. From the result obtained, the study expects that integration of support data will efficiently increase the accuracy of extraction and more useful information can be acquired in further study. On the other hand, a comparative study of threshold decision needs to be verified, put it differently, whether using head/tail break with visual inspection on extracted city boundaries is helpful or not.

Erosion of a river bed has important implications with respect to scour around river structures such as bridges, transport of contaminants attached to the sediment, and disruption or destruction of aquatic habitats. Erosion occurs when the resistive strength of the sediment is overcome by the hydrodynamic forces produced by the flow of water. This resistance to erosion in a sediment originates from gravity or interparticle forces for coarse sediment (sand and gravel) and fine sediment (silt and clay), respectively. Since the erosion of fine sediment depends on the combination of many interparticle forces, and this combination fluctuates widely amongst different fine sediments, past studies have had difficulty finding a consistent method to estimate fine sediment erosion. This study analyzes sediments that fall in the transition size range between fine and coarse sediments and compares the findings with those from fine sediments (Wang 2013) and sandy coarse sediments (Navarro 2004, Hobson 2008), in order to correlate the erosion rates of both sediment types to their physical characteristics. In this study, kaolin-sand mixtures were prepared by mixing various percentages of Georgia kaolin by weight ranging from 30% to 100% with industrial fine sand and tap water. Geotechnical and other tests of sediment properties were performed to measure water content, bulk density, grain size distribution, temperature, pH, and conductivity of these mixtures. Hydraulic flume experiments measured the erosion rates of each sediment and these rates were used to estimate the critical shear stress correlating to that mixture. Relationships between the physical properties of the sediment and critical shear stress were developed by multiple regression analysis. An alternative option of estimating the critical shear stress by a weighted equation, which uses the combination of fine sediment erosion and coarse sediment erosion equations separately, was explored and found to be a viable and accurate option to estimating both coarse and fine sediment erosion from the same parameters and equation. The results from this study can be used to estimate sediment erodibility and thus river bed stability based on simple tests of physical properties of the river bed sediment and will help predict scour around bridges and other flow obstructions.

First year students at university level encounter various challenges that might impact on their success or failure. At this level, learning is fairly dependent on extensive and intensive reading, thus the reader should have an adequate vocabulary size to assist with the reading comprehension process. Knowledge of vocabulary (or words) is deemed an essential factor in reading proficiency, mainly because meaning is derived from words and also because of the connection between words and comprehension of text. This study investigated the particular relationship among vocabulary size and vocabulary depth and reading comprehension of 105 first year B.Ed. students majoring in English at a university in the North West Province. Also, the vocabulary test results of two different groups, first and fourth years, were compared to determine if advancement of vocabulary levels occur over the study period of four years. A quantitative research approach was used in which the study population was required to complete standardised vocabulary size and vocabulary depth tests, reading comprehension tests and a survey questionnaire. The results were statistically computed to determine the relationship between vocabulary size and breadth and reading comprehension. The results showed a positive and significant effect size correlation between vocabulary size and depth, and reading comprehension. The participants in the study were mainly Afrikaans speaking students who received their school education in Afrikaans. The instruments used in the research were the Vocabulary Levels test (Nation, 1990), Read’s Word Associates Test (1992) and TOEFL reading comprehension tests. The questionnaire was added to determine previous exposure to English and current reading habits of the participants. A two-tailed Pearson product moment correlation and multiple regression analyses were run in order to determine which of the variables, vocabulary size or depth, makes a more significant contribution to reading comprehension and also to establish which variable was the most significant predictor of academic success in the June examination. Vocabulary size was identified as predictor for success in the June examination; furthermore, if gender is used as independent variable, different vocabulary size tests are identified for males and females. / MEd (Curriculum Development), North-West University, Potchefstroom Campus, 2015

First year students at university level encounter various challenges that might impact on their success or failure. At this level, learning is fairly dependent on extensive and intensive reading, thus the reader should have an adequate vocabulary size to assist with the reading comprehension process. Knowledge of vocabulary (or words) is deemed an essential factor in reading proficiency, mainly because meaning is derived from words and also because of the connection between words and comprehension of text. This study investigated the particular relationship among vocabulary size and vocabulary depth and reading comprehension of 105 first year B.Ed. students majoring in English at a university in the North West Province. Also, the vocabulary test results of two different groups, first and fourth years, were compared to determine if advancement of vocabulary levels occur over the study period of four years. A quantitative research approach was used in which the study population was required to complete standardised vocabulary size and vocabulary depth tests, reading comprehension tests and a survey questionnaire. The results were statistically computed to determine the relationship between vocabulary size and breadth and reading comprehension. The results showed a positive and significant effect size correlation between vocabulary size and depth, and reading comprehension. The participants in the study were mainly Afrikaans speaking students who received their school education in Afrikaans. The instruments used in the research were the Vocabulary Levels test (Nation, 1990), Read’s Word Associates Test (1992) and TOEFL reading comprehension tests. The questionnaire was added to determine previous exposure to English and current reading habits of the participants. A two-tailed Pearson product moment correlation and multiple regression analyses were run in order to determine which of the variables, vocabulary size or depth, makes a more significant contribution to reading comprehension and also to establish which variable was the most significant predictor of academic success in the June examination. Vocabulary size was identified as predictor for success in the June examination; furthermore, if gender is used as independent variable, different vocabulary size tests are identified for males and females. / MEd (Curriculum Development), North-West University, Potchefstroom Campus, 2015

This thesis is concerned with student understanding of key concepts in electrical engineering teaching within higher education. Anecdotal evidence suggests that many students struggle to understand threshold concepts and therefore encounter difficulties in learning theoretical models which are underpinned by such theoretical concepts. This research utilised a mixed methods approach to investigate the factors that influence student understanding of key theoretical concepts within electrical engineering. The initial study used a questionnaire to evaluate student understanding of concepts which were identified by teaching staff as being core to a particular module. The study identified that students commenced the module with poor understanding and that instruction on the module ELC040 Electrical Machines and Systems did not lead to improved understanding of core concepts. This suggests that the roots of student misunderstanding lay elsewhere. Desk research was subsequently employed to explore the sources of student misunderstandings. Performance data was analysed and demonstrated that the roots of the student misunderstanding of Electrical Machine Theory lay in the pre-requisite module Electrical Power B. Students routinely failed to achieve high levels of understanding in this module and as a result were unable to successfully build upon it in the third year module. Semi-structured interviews were then undertaken with Part C students who were undertaking the Electrical Machines and Systems module. In addition, structured interviews were administered with the Part B students. The interviews aimed to establish the study practices adopted by students across both years. The study showed that students found the ELA001 module difficult, and the majority believe that most other students felt the same way as they did. Students provided evidence of poor study techniques, by reporting last minute sessions to complete coursework and last minute revision for exams. This research informed the development of an interactive learning tool which was piloted on a small cohort of students. The research has also established that there are many influences on the development of student understanding of threshold concepts within electrical engineering and argues for a more active style of teaching in order to address student misunderstanding.