The uprooting of trees due to high winds, or blowdown, is a common occurrence throughout the world. Rare, large scale blowdown events have the ability to drastically alter forest landscapes on a timescale of hours. Alone or when combined with other forest disturbances such as fires and insect outbreaks, blowdowns have the potential to modify existing watershed characteristics. Little information is known about how large-scale blowdowns affect the physical environment in general and watershed-wide sediment yield and deposition rates in particular. The few studies that have taken place have yielded inconclusive or somewhat contradictory results. Given the large scale of some events and the potential impact of such events it is important that the geomorphological effects of blowdowns be better understood, not only from a basic process but also from an applied perspective. Lakes receive and store a significant fraction of the disturbed sediment formerly found in the soil column and lake sediments have proven to be reliable and accurate records of sedimentation characteristics within their catchments. For the purpose of this study, it was hypothesized that areas subjected to blowdown will have increased erosion rates. It was also hypothesized, that lakes within blowdown areas will be subjected to accelerated sedimentation rates following events. In order to test these hypotheses and isolate the effects of a blowdown on sedimentation rate three small mountain lakes in the Mt. Zirkel Wilderness Area, Colorado were cored. The lakes selected consist of a control lake with no known recent history of blowdown in its watershed and two lakes that receive direct runoff from watersheds and slopes that were affected by a major blowdown event in 1997, the Routt-Divide Blowdown. One core was dated using the 210Pb method and multiple cores were analyzed for organic and inorganic matter concentrations to determine if changes in sedimentation rates and/or sediment compositions occurred following the event. In the case of the two lakes studied that had catchment slopes affected by blowdown, somewhat surprisingly, no significant change was observed with respect to sedimentation rates or sediment composition. In fact, sedimentation rates obtained from the dated core exhibited a decreasing trend that began decades prior to and continued through the blowdown event. This suggests that in the area affected by the Routt-Divide Blowdown it is likely that long-term changes in climate and the effect these changes have on the amount and type of vegetation present are the dominant influence on sedimentation rates, and that the Routt-Divide Blowdown of 1997 did not increase the rates. Based on further evaluation of the sites and the event it appears that slope characteristics and treefall orientation may be significant factors controlling the amount and type of disturbed sediment that moves downslope. In the case of future large-scale blowdowns, where their effect on water quality or sedimentation rates is in question, dominant treefall orientation with respect to slope should be an integral part of initial assessment, especially in remote area, and be considered when interpreting data from any similar study.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Small and medium toilet manufacturing businesses in Peru face significant problems such as low productivity because of a high rate of production losses. To address this issue, the present study proposes the application of a lean manufacturing technique, such as the Poka-Yoke model, which improves the production flow within the company by implementing a transportation cart with a safety system to help reduce material falls during the manufacturing process. The results showed a 24% increase in productivity and reduction in problems of damaged products that did not meet quality standards, thus preventing their subsequent reprocessing. / Revisión por pares

Teachers are motivated by different factors to choose teaching, including mathematics education as a career. Before 1994 career guidance was not often used to inform career choice, especially in the rural schools of South Africa. During that period, a shortage of mathematics teachers was prevalent. After 2007, the government introduced the Funza Lushaka Bursary to recruit mathematics teachers. The purpose of this study is to investigate the factors that influence teachers to choose mathematics education as a career. An explanatory sequential mixed methods approach was utilised to collect quantitative data through a survey and then qualitative data through interviews. To achieve this, this study was framed by a pragmatic paradigm. Two theoretical lenses, the existence, relatedness and growth (ERG) theory and Factors Influencing Teaching Choice framework (FIT-CF), were blended to guide the study and to address the research question, “Why do teachers choose mathematics education as a career?” Convenient sampling was used to select participants (n=57) for the survey, from whom 9 participants were later interviewed using stratified random sampling. The sample was constituted by three cohorts of mathematics teachers who started teaching on or before 1994; after 1994 to 2007; and after 2007. The conclusions drawn from the small sample were that teachers were mainly influenced by altruistic factors, followed by intrinsic factors. In addition, female teachers were influenced more by altruistic and intrinsic factors than their male counterparts. Variation in terms of the influence of altruistic, extrinsic and past events factors across the three cohorts was revealed. Generally, altruistic factors were the most influential factors across the three cohorts. Understanding the factors that influenced the teachers to choose mathematics education as a career could provide insight on how recruitment, retention and effectiveness of mathematics teachers could be optimised in South Africa. / Dissertation (MEd)--University of Pretoria, 2020. / Science, Mathematics and Technology Education / MEd / Unrestricted

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abstract: This dissertation aimed to evaluate the effectiveness and drawbacks of promising fall prevention strategies in individuals with stroke by rigorously analyzing the biomechanics of laboratory falls and compensatory movements required to prevent a fall. Ankle-foot-orthoses (AFOs) and functional electrical stimulators (FESs) are commonly prescribed to treat foot drop. Despite well-established positive impacts of AFOs and FES devices on balance and gait, AFO and FES users fall at a high rate. In chapter 2 (as a preliminary study), solely mechanical impacts of a semi-rigid AFO on the compensatory stepping response of young healthy individuals following trip-like treadmill perturbations were evaluated. It was found that a semi-rigid AFO on the stepping leg diminished the propulsive impulse of the compensatory step which led to decreased trunk movement control, shorter step length, and reduced center of mass (COM) stability. These results highlight the critical role of plantarflexors in generating an effective compensatory stepping response. In chapter 3, the underlying biomechanical mechanisms leading to high fall risk in long-term AFO and FES users with chronic stroke were studied. It was found that AFO and FES users fall more than Non-users because they have a more impaired lower limb that is not fully addressed by AFO/FES, therefore leading to a more impaired compensatory stepping response characterized by increased inability to generate a compensatory step with paretic leg and decreased trunk movement control. An ideal future AFO that provides dorsiflexion assistance during the swing phase and plantarflexion assistance during the push-off phase of gait is suggested to enhance the compensatory stepping response and reduce more falls. In chapter 4, the effects of a single-session trip-specific training on the compensatory stepping response of individuals with stroke were evaluated. Trunk movement control was improved after a single session of training suggesting that this type of training is a viable option to enhance compensatory stepping response and reduce falls in individuals with stroke. Finally, a future powered AFO with plantarflexion assistance complemented by a trip-specific training program is suggested to enhance the compensatory stepping response and decrease falls in individuals with stroke. / Dissertation/Thesis / Doctoral Dissertation Mechanical Engineering 2019

Main findings Although the data did not allow the inclusion of non-identified or “unknown” sources, allocation of the impact at the receptor point to the identified sources proved possible and useful in comparing individual tailings dams contributions. The No. 4 tailings dam has been identified as one of the major contributors to PM10 concentration at West Village. The average PM10 gravimetric concentration recorded at West Village was 18.4 μg/m3 and the concentration with the light scatter method was 15.4 μg/m3. Black carbon has been identified as significant contributor to overall PM10 mass concentrations with up to 34% in the winter season. Source appointment from receptor-based measurements has not been previously conducted at Driefontein Gold Mine. Source apportionment can make a valuable contribution in attempts to reduce air pollution. At a site where particulate matter is the predominant pollutant from a variety of potential sources, the contributions from the individual sources may be difficult to distinguish especially if the sources fall within a single category type with similar pollutant profiles. It would be useful to ascertain the individual contributions so that the effectiveness of existing control measures can be determined and areas where additional controls may be required can be identified. Too this effect, potential dust sources at and around a gold mine were identified. Samples of the dust sources were collected and analysed for their elemental compositions and abundances. A receptor point in a mine village was selected and equipped with an ESampler PM10 dust monitor as well as an aethalometer, the MicroAeth AE51 (MicroAeth). Monthly receptor samples were collected and analysed for their elemental concentrations. The elemental compositions of the potential sources and the concentrations at the receptor were statistically analysed for 12 periods of a month each to determine the possible contributions to the PM10 concentration at a mine village (West Village, Driefontein Mine, near Carletonville). Main conclusions Operational tailings dams can under, certain conditions contribute the major portion of fallout dust and PM10, even more than dormant tailings dams. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Chemical Engineering / Unrestricted

Though some have the opportunity to access water conveniently, getting a small amount of water may be tough and exhausting for others. In this paper, I will discuss on the right to water, which is explicitly expressed by a UN resolution as a human right. Sever water crisis, or drought, has been far beyond a lack of precipitation, but a phenomenon, occurring through a set of human activities, and interferences. My initial aim is to find out how and in what ways some human activities in Iran, interfered environment in a way that affected precipitation level and led to water crisis. And the second, is to show how unethical these activities may be, as they have been simply avoidable. Therefore, the Iranian governmental organizations (like municipalities) are ethically responsible to provide the required water, since the right to water is called a basic human right by UN. These facts obliges them to hinder these activities to secure this basic need. On this way, I make use of Nussbaum's capability approach to show, depriving the citizens from one of their basic rights (the right to water), through influencing climatic order (in a way that decreases precipitation level or depletes water resources), is considered a moral issue, therefore, it is binding for the state to take measures responsively to stop and control it in the future.

Falls are the number one mechanism of injury for The Trauma Center and Johnson City Medical Center (JCMC TC). JCMC TC is one of two level one trauma centers in the region and one of only six in the state. The main method for trauma prevention is outcome specific education and awareness. Injury prevention education is a critically needed area in the field of trauma and emergency care. Falls are the number one cause of injury in populations age >65. Socioeconomic status, age, gender, and race are all mitigating factors in the likelihood of greater length of stays, death in hospital, and death within one year of discharge for those who fall in a home setting. According to the CDC, people over the age of 75 are four to five times more likely than people under 75 to be admitted to a long-term care facility for more than a year. What is the relationship between patient characteristics and fall related outcomes in a level one trauma center? We looked at associations between patient demographics and associated outcomes for those admitted to the trauma center secondary to a ground level fall (GLF) in the home. Dataset: De-identified National Trauma Databank information was compiled by the JCMC Registrar for the past 8 years for the metrics: Injury Severity Score (ISS), length of stay, 48hr readmission, and disposition (home, nursing home, skilled nursing facility (SNF)).Demographic information, along with mechanism of fall, was collected for each patient. Patient age, gender, and date of injury was all used for statistical analysis and trend recognition. Statistical Analysis: Bivariate analyses included independent samples t-tests and Oneway ANOVA to find differences between groups. Results: T-test results show women are significantly more likely than men to be admit for a ground level fall (p<.001) and those with a higher ISS are more likely to have an extended stay in an inpatient setting (p<.001). One-Way ANOVA analysis of collected data shows an annual increase from 2006-2013 of trauma admissions for ground level falls (p<.01). Eight year analysis showed a two-fold increase in these admissions. Over 30% of patients admitted with a GLF are discharged to a SNF leading to higher societal costs due to Medicare reimbursement rates. Diagnosis related groups codes (DRG) dictate Medicare reimbursement rate of $14,091 per patient with an average facility cost of $14,196 per patient with no readmissions (Unplanned readmission within 180 days occurred at a rate of 8.3%). Conclusion: Fall education programs are necessary and needed in rural level one trauma centers to educate citizens on causes and methods of preventing falls in their homes. A decrease in these falls would lead to an increase in productive years of life and a reduction in strain on the hospital system.

Although a great deal is known about the etiology of falls in elderly individuals, fall accidents continue to represent a significant burden to elders residing in long-term care facilities. It has been stated that 75% of deaths due to falls in the United States occur in the 13% of the population age 65 and over. The first objective of the study was to identify which fall-predictor variables acknowledged in the research literature are associated with increased fall frequency with the older population. Identifying specific predictor variables related to a high occurrence of falls in long-term care setting can assist in the redesign of tools and programs aimed to recognize fall risk, and prevent fall-related accidents and fatalities in the geriatric population. The second objective of the study was to identify which combination of predictor variables could better predict the frequency of falls. A history of falls variable was the only predictive variable that differed significantly between groups of residents who had sustained subsequent falls and those who had not. Other variables including age, mental status, day number of stay, elimination, visual impairment, confinement, blood pressure drop, gait and balance, and medication were found to not be statistically significant between groups of fallers and non-fallers. In this setting, the current design of the tool had limited accuracy and exhibited an inability to effectively discriminate between resident populations at risk of falling and those not at risk of falling. Consequently, the current fall risk assessment tool is not adequate for assessing fall risk in this clinical setting. / Master of Science

This thesis projects presents a system for gathering and using data in the context of a smarthome research enviroment. The system was developed at the Human Health and ActivityLaborty, H2Al, at Luleå University of Technology and consists of two distinct parts. First, a data export application that runs in the H2Al enviroment. This application syn-chronizes data from various sensor systems and forwards the data for further analysis. Thisanalysis was performed in the iMotions platform in order to visualize, record and export data.As a delimitation, the only sensor used was the WideFind positional system installed at theH2Al. Secondly, an activity recognition application that uses data generated from the iMotionsplatform and data export application. This includes several scripts which transforms rawdata into labeled datasets and translates them into activity recognition models with the helpof machine learning algorithms. As a delimitation, activity recognition was limited to falldetection. These fall detection models were then hosted on a basic server to test accuracyand to act as an example use case for the rest of the project. The project resulted in an effective data gathering system and was generally successful asa tool to create datasets. The iMotions platform was especially successful in both visualizingand recording data together with the data export application. The example fall detectionmodels trained showed theoretical promise, but failed to deliver good results in practice,partly due to the limitations of the positional sensor system used. Some of the conclusions drawn at the end of the project were that the data collectionprocess needed more structure, planning and input from professionals, that a better positionalsensor system may be required for better fall detection results but also that this kind of systemshows promise in the context of smart homes, especially within areas like elderly healthcare.