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Faktorer vid planering av matematikundervisning på låg- och mellanstadiet / Factors in planning mathematics teaching in primary schoolSlezinger, Vivianne, Jensen, Josefine January 2024 (has links)
Forskning visar att läroboken i matematik har en stor roll bland de yrkesverksamma lärarna i grundskolan. Läroboken kan användas på olika sätt och i olika stor utsträckning. I Sverige är läroböckerna inte granskade av myndigheter vilket gör att det inte går att garantera att de följer läroplanen. Detta väckte ett intresse över hur matematikundervisningen ser ut och vad som påverkar planeringen. Detta undersöktes genom kvalitativa och kvantitativa frågor som besvarades genom en enkätundersökning och intervjuer. Det insamlade materialet kom från 30 enkätsvar och tre intervjuade lärare. För att analysera datainsamlingen användes ramfaktorteorin och inslag av antropologiska didaktiska teorin (ATD). Med inspiration av tematisk analys kunde faktorer grupperas, där resultatet visar att planeringen påverkas av läraren, eleverna, matematiken och undervisningsmetoder samt andra faktorer som rör miljön och styrning. Det visade sig även att läroboken var den undervisningsmetod som nämndes flest gånger och att undervisning utan lärobok till största del består av spel/lek och lärarledd problemlösning i grupp. Slutsatsen av studien är att läroboken har en stor inverkan på den svenska matematikundervisningen, men det framkommer att lärarna som har deltagit i undersökningen försöker variera sin undervisning och anpassar den efter eleverna. Detta leder till att det som eventuellt saknas i läroboken kan förväntas att kompenseras med andra metoder.
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Application de la technique de thermodésorption pour l'analyse de 93 COV et le screening des COV dans l'air des lieux de travail / Application of thermodesorption technique to 93 VOC assay and screening of VOC in workplace airMaret, Laure 20 December 2013 (has links)
Aujourd'hui, la gestion du risque en milieu profesionnel ainsi que l'évaluation de l'exposition aux polluants, tels que les Composés Organiques Volatils (COV) présents dans l'air deviennent une nécessité tant la qualité de l'air des lieux de travail peut être à l'origine de problèmes de santé ou de maladies professionnelles reconnues. Dans le but de répondre à ces exigences de sécurité, l'Université Claude Bernard Lyon 1 a institutionnalisé et développé une Cellule Analyse Hygiène Sécurité et Environnement en lien direct avec le service SHS préexistant. Cette cellule est chargée de la mise en place d'une méthodologie de surveillance de la qualité de l'air intérieur de l'ensemble des locaux de l'université (14 sites, environ 80 laboratoires) en accord avec le code du travail et de l'environnement. Afin de pouvoir assurer l'ensemble des analyses inhérentes aux lieux de travail, le SHS a défini 45 composés comme prioritaires ajoutés à la liste du SHS et portent à 93 le nombre de COV identifiés et quantifiés. La méthode de séparation et d'identification mise en place permet d'atteindre des limites de quantification largement inférieures aux VLCT et VLEP 8 heures fixées par la législation. Des campagnes de prélèvement ont pu ainsi être organisées en collaboration avec le SHS et être lancées au sein de l'université / Over the past 10 years, indoor air quality has become a real Health and Safety concern, especialty in the workplace, which has led to the legislation proposal of concentrations guidelines for pollutants such as Volatiles Organic Compounds (VOC). To comply with the Safety requirements, The Claude Bernard University Lyon 1 has institutionalized and developed an Environment, Health and Safety Unit (HSE Unit), to provide the analyses for the Health and Safety team (SHS). This specialist unit has developed a supervision methodology to control the indoor air quality in all the buildings of the university, including all the 80 research and training laboratories. In order to carry out the assessment, the SHS team defined 45 compounds classified as priority, according to their threshold limit values (TLV-TWA or TLV-STEL) to the workers. To this list of 45 VOC another list containing 48 VOC is added. Evaluation of the trapping capacity of each sorbent, for a mix containing 93 VOC has been studied. Moreover, separation and identification methods were developed and optimized allowing to reach a quantification limit lower than professional limit value exposure. Using these methods and the results of the trapping comparisons, different applications were implemented, such as sampling campaigns in different laboratories
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Treatment Effects of Incisor Positioning on Anterior Tooth DisplayEberle, Scott J. 01 January 2006 (has links)
The purpose of this study was to determine the effect of changes in maxillary incisor position on anterior tooth display (ATD) in adult (n = 21) and adolescent (n = 38) orthodontic patients. The effects of anterior-posterior, vertical, and angular changes of the maxillary central incisor position during orthodontic treatment were evaluated relative to changes in the amount of ATD measured from pretreatment (TI) and posttreatment (T2) lateral cephalometric radiographs of existing patient records.Results showed a significant relationship between starting ATD and ATD change during treatment for both adults (P = ,006) and adolescents (P
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Studies of the Human Head from Neonate to Adult: An Inertial, Geometrical and Structural Analysis with Comparisons to the ATD HeadLoyd, Andre Matthew January 2011 (has links)
<p>Child head injury is a very costly problem, both in terms of morbidity/mortality and direct medical costs. In fact, it is the leading cause of death and disability for those in the United States under age 18-years-old. Currently, head injury in children ages newborn to 19-years-old is responsible for 7500 deaths per year--30% of all childhood deaths in the United States. Given its importance and effect on the population, the study of pediatric head injury is greatly hindered by the lack of available pediatric post mortem human specimen (PMHS) data. As a substitute for PMHS testing, anthropometric test devices (ATDs) and finite element models (FEMs) have been developed to model the head. However, there is a dearth of data for the design and validation of these models. </p><p>The goal of this study was to use pediatric PMHSs to both advance the study of pediatric head injury and to provide validation data for ATD and finite element head models. 14 pediatric heads, 8 adult heads, and 6 ATD heads were studied to obtain geometrical, inertial, structural stiffness, and impact properties. The computational tomography (CT) method was used on pediatric heads to get inertial properties, and clinical CT scans were used to develop average head and skull contours for 12 different age groups. To obtain impact properties, the heads were dropped onto a rigid plate from 15cm and 30cm, and the acceleration-time pulses were analyzed to obtain acceleration HIC and other impact properties. The heads were then placed between two aluminum plates and compressed at four different rates to obtain structural stiffness values. Using the PMHS results, the ATD heads were compared against age-matched human heads, and the scaling rules used for ATD production were tested for accuracy. </p><p>The study found that between the ages of 5-months-old and 22-months-old, the human head was susceptible to fracture from drops as low as 15cm. The structural stiffness of the human head was shown to increase by three orders of magnitude from neonate to adult. For the impact properties, the human head's peak acceleration and head injury criteria increased with age, while the human head's pulse duration and coefficient of restitution decreased with age. The 50th percentile Hybrid III head was found to adequately model the response of the adult head for multiple head impact locations, while the 3-year-old Q3 child ATD was found to be too stiff during impact. Overall, this study provides novel data that can be directly applied to pediatric head injury curves, and pediatric ATD and finite element head models.</p> / Dissertation
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Submarining and Abdominal Injury for Rear-Seated Mid-Size Males during Frontal CrashesGuettler, Allison Jean 05 July 2023 (has links)
Historically, the rear seat has been considered safer compared to the front seat for all restrained occupants; however, studies have found that the front seat in newer vehicles might be safer for older adults than the rear seat. While adults make up only 19% of rear seat occupants in frontal crashes, they make up 48% of fatalities (Tatem and Gabler, 2019). The rate of rear-seat occupancy by adults is expected to increase due to the use of ride share services and the potential of autonomous vehicles. Minimal research has been done to assess rear-seat occupant protection for a mid-sized adult male. Submarining, in which the lap belt slips off of the pelvis and directly loads the abdomen, is of particular concern as a restraint-based injury mechanism of the abdomen. The objective of this study is to investigate submarining protection and abdominal injury risk for rear-seated mid-sized male occupants in frontal crashes and to assess the biofidelity of two anthropomorphic test devices (ATDs) with respect to submarining response when compared to post-mortem human surrogates (PMHS). Twenty-four frontal crash sled tests were conducted with the THOR-50M and Hybrid III 50th-percentile male ATDs in three crash conditions and seven modern vehicles. The vehicles included a minivan, an SUV, 3 compact SUVs, and 2 sedans from the US vehicle fleet (model years 2017-2018). Four vehicles had conventional restraints (ie. 3-point belt with retractor at the shoulder) in the rear seat and three vehicles had advanced restraints (ie. 3-point belts with a pretensioner and load limiter at the retractor). Two of the crash conditions were vehicle-specific pulses: NCAP85 (ΔV = 56 kph) and Scaled (ΔV = 32 kph). The final pulse was a Generic (ΔV = 32 kph) pulse, created by averaging all seven Scaled pulses. Matched PMHS tests were conducted on four of the vehicles in the NCAP85 condition. Two tests were conducted for each vehicle with 8 PMHS for a total of 8 sled tests. The occurrence of submarining was identified and assessed for severity by: symmetry of lap belt slip, degree of abdominal loading, and forward excursion of the pelvis. Pelvis and lap-belt kinematics were assessed for the matched NCAP85 tests to identify trends with respect to submarining. Damage to the abdomen, pelvis, and lumbar spine of the PMHS was identified during post-test autopsy. The Hybrid III did not submarine in any test, but the THOR submarined in 16/24 tests. Three PMHS underwent submarining in 2/4 vehicles, and the THOR submarined in 3/4 vehicles in the matched NCAP85 tests. Three PMHS did not undergo submarining but sustained pelvis fractures at lap belt loads of 7.4 kN and higher, and damage to the abdominal viscera occurred regardless of submarining occurrence. Pelvis and lap-belt kinematics revealed the complex nature of the interactions of the occupant and the restraints within each vehicle environment, but did not clearly differentiate between submarining and non-submarining tests. The Hybrid III was not able to predict submarining risk for the PMHS in the rear seat environment. While the THOR underwent submarining, it was not perfect in predicting submarining risk. Pelvis geometry, lap belt engagement, and other factors contributed to the differences in submarining between the two ATDs and the PMHS. Restraint type was not indicative of whether or not the THOR or PMHS would submarine. Many other factors in the rear seat environments of these vehicles likely contribute in combination to the effectiveness of submarining prevention and occupant protection in the rear seat. This study provides information regarding submarining and abdominal injury for three surrogate types, two crash severities, and seven modern, real-world vehicle environments. Ultimately, this study found substantive gaps in occupant protection in the rear seats of modern vehicles for mid-sized adult male occupants.
Tatem, W. M., and Gabler, H. C. (2019). Differential fatality risk between rear and front seat passenger vehicle occupants in frontal crashes. In Proceedings of the 2019 International IRCOBI Conference on the Biomechanics of Injury (pp. 554–560). / Doctor of Philosophy / Historically, the rear seat has been considered safer than the front seat for restrained occupants in frontal crashes. However, with advances in safety systems for the front seat, studies have found that the front seat might be safer for older adult occupants. The objective of this study is to investigate submarining protection and abdominal injury risk for rear-seated mid-sized male occupants in frontal crashes. Submarining occurs when the lap belt slips off of the pelvis and directly loads the abdomen, potentially producing severe abdominal injuries. Twenty-four sled tests were conducted with the THOR-50M and Hybrid III 50th-percentile male anthropomorphic test devices (ATDs) in three crash conditions and seven modern vehicles. The vehicles selected included a minivan, SUVs, compact SUVs, and sedans from the US vehicle fleet. Three of the vehicles had advanced restraints in the rear seat and four had conventional restraints. The three crash conditions were a generic low speed test and a low and high-speed vehicle-specific crash pulse. Eight tests were conducted with eight different post-mortem human surrogates on a subset of four vehicles (2 with advanced restraints, 2 with conventional restraints) using the high-speed crash condition. The Hybrid III never submarined, but the THOR submarined in 16 out of 24 tests (5 out of 7 vehicles). Three out of eight PMHS submarined, in two of the four vehicles. Three heavier PMHS sustained pelvis fractures, and all but one PMHS had sustained damage to the abdominal viscera. Restraint type was not an indicator of submarining risk in the rear seat, suggesting that other seat and vehicle design variables contribute to submarining risk. Comparison of the responses of the ATDs with the PMHS suggests that the THOR is a more reasonable surrogate than the Hybrid III for submarining assessment in the rear seat. Inclusion of data from other body regions is necessary to make a definitive determination of the appropriate ATD for the assessment of occupant protection for a mid-sized male in the rear seat during frontal crashes. Overall, this study suggests that protection against submarining and injury to the pelvis and abdomen for mid-sized male passengers in the rear seat of modern vehicles in the US fleet could be improved.
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Comparative effectiveness on various Graves’ Disease treatment optionsMoses, Carissa S. 30 January 2024 (has links)
Graves’ Disease is an autoimmune disorder represented by the overproduction of thyroid hormones (hyperthyroidism). Graves’ Disease is more common among women of reproductive age, and genetic, endogenous, and environmental factors influence the pathogenesis of Graves’ Disease. Graves’ Disease presents with many clinical manifestations, such as tachycardia, fatigue, heat intolerance, palpitations, weight loss, muscle weakness, alterations in menstrual cycles, insomnia, hair loss, goiter, and others. Currently, there are three main treatment routes for Graves’ Disease: antithyroid drugs, radioactive iodine therapy, and thyroidectomy. Antithyroid drug therapy has a high relapse rate. At the same time, both radioactive iodine and thyroidectomy eradicate or surgically remove the tissue of the thyroid and lead to the consequence of developing another disease, hyperthyroidism, that requires a life-long supplementation of the thyroid replacement hormone, levothyroxine. Presently, investigations are focused on finding new therapeutics that can supplement existing treatments as a combination therapy that can lengthen the remission period after cessation of ATDs or conduction of RAI therapy. Future research is exploring treatment options that target different components of the immune system response pathway, the thyroid stimulating hormone receptor or thyrotropin receptor autoantibodies, that have the potential to cure Graves’ Disease.
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Evaluation of dietary phytochemicals on sex differentiation and growth in Nile tilapia (Oreochromis niloticus)Rodriguez Montes de Oca, Gustavo Alejandro 02 December 2005 (has links)
No description available.
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The Development and Validation of a Biofidelic Synthetic Eye for the Facial and Ocular CountermeasUre Safety (FOCUS) HeadformKennedy, Eric A. 13 September 2007 (has links)
There are over 1.9 million eye injuries per year in the United States with over 30,000 patients left blind in at least one eye as a result of trauma. Some of the most severe eye injuries can occur in automobile accidents and from sports related impacts. Eye injuries in the military environment are even more prevalent and are generally more severe than eye injuries to civilians. The rate of eye injuries has dramatically increased in warfare in recent years, rising from 2% of all casualties during World War I and World War II to over 13% of all combat injuries in Operation Desert Storm. While many of the conflict-related eye injuries are caused by shrapnel and other debris, nearly 25% of the injuries are also caused by blunt trauma from motor vehicle and helicopter crashes, falling, and direct hits from blunt objects.
In order to develop safety countermeasures effective at preventing these eye injuries, as well as evaluate the eye injury potential of different impacts, it is desirable to have the capability for distinguishing between injurious and non-injurious eye impacts. Current anthropometric test device (ATD) headforms lack instrumentation and facial features to allow detailed assessment of eye or discrete facial injuries. Therefore, the purpose of this dissertation is to present the development and validation of the Facial and Ocular CountermeasUre Safety (FOCUS) headform's synthetic eye and orbit and corresponding eye injury risk criteria. / Ph. D.
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Characterization of soft tissue and surrogate materials across varied loading methodsDennis, Cole 26 July 2025 (has links)
Exploring the mechanical properties of soft tissues under compressive loading is crucial for understanding their role in automobile incidents. Soft tissues, which serve as cushions or padding between bone and vehicle interiors, significantly influence contact duration and forces, thereby altering incident kinematics and injury risk assessment.
In this investigation, muscle and soft connective tissues from post-mortem human subjects (PMHS) forearms were excised and subjected to compression and indentation testing methods at various rates and strains. Anthropomorphic Test Devices (ATDs) upper extremity foam and vinyl foam composite material surrogate tissues underwent similar testing for comparison. High impact rates simulating those in high-speed car collisions were achieved using a custom-built drop tower.
The results revealed substantial differences in stiffness between soft tissues and ATD materials across most loading rates and strains, although some exceptions were noted at higher rates and strains. Indentation and modified Zener models were used to quantify material parameters. The indentation model could characterize human muscle, soft connective tissues and ATD vinyl foam composites, but fell short with ATD foam materials. The Zener model effectively derived material parameters for the tested human tissues but encountered difficulties characterizing both ATD materials. This highlights the need for further refinement to develop a constitutive model for both materials.
These findings provide a solid basis for advancing ATD surrogate materials and have broader implications for soft tissue research. Moreover, this work represents a crucial step towards enhancing safety standards in the automotive industry. / Thesis / Master of Science in Biomedical Engineering / Soft tissues are crucial in mitigating impact effects in various loading scenarios, yet their specific roles are complex and poorly understood. Understanding soft tissues' role in these loading scenarios is critical for understanding injury risk tolerances.
This study aimed to characterize muscle and soft connective tissue behaviour during compressive loading scenarios using various techniques and modelling approaches. This was done through compressive loading tests on soft tissues and comparing these same tests with data from current crash test dummy surrogate tissues.
The results showed that the soft tissues were less stiff than the crash test dummy materials in most scenarios. It was also apparent that different stiffnesses were seen depending on soft connective tissue and muscle tissue composition.
This study provides insights into the rate dependence of materials, alongside the relevance of how different compositions affect their loading properties. This characterization also revealed significant discrepancies between the responses of current surrogates and human muscle and soft connective tissues.
This work offers valuable observations and data for refining ATD surrogates and enhancing their fidelity in simulating real-world impact scenarios. Such advancements are pivotal for improving safety standards.
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Digitala verktyg i matematikundervisningen - medel eller mål? : En kvalitativ studie med fokus på hur matematiklärare på gymnasiet använder och motiverar digitala verktyg i undervisningen i samband med digitaliseringen i ämnet / Digital tools when teaching mathematics - a tool or a goal? : A qualitative study that focuses on how senior high school mathematics teachers use and motivate digital tools in their teaching related to the digitalization of the subjectElvung, Ellen, Petersson, Matilda January 2019 (has links)
Idén till denna studie uppkom i samband med den förändring i styrdokumenten gällande digitalisering av ämnet Matematik som trädde i kraft 2017. Syftet med studien är att undersöka hur lärare använder och motiverar användandet av digitala verktyg i matematikundervisningen, samt i vilken utsträckning de har förändrat sin undervisning i samband med digitaliseringen av läroplanen. Fem gymnasielärare i matematik deltog i semi-strukturerade intervjuer och fyra matematiklektioner observerades strukturellt. Resultatet visar att lärare använder digitala verktyg både som ett medel för att ge eleverna matematisk kunskap, men också som ett mål för att eleverna ska lära sig de digitala verktygen. Lärarna motiverar användningen av digitala verktyg med att det sparar tid, förenklar representationer av olika koncept, och att de i vissa fall underlättar undervisningen. Lärarna menar också att digitala verktyg kan bidra med att införa nya metoder för lärande, att de förbereder eleverna för nationella prov och för ett liv i det digitala samhället. Lärarna gjorde små eller inga ändringar i sin undervisningspraktik i samband med förändringen i läroplanen, och i de fallet en förändring skedde hade läraren ”öppnat upp” för utökad användning av digitala verktyg. / The idea for the study appeared as a result of the change related to the digitalization of the subject Mathematics in the Swedish senior high school that took effect in 2017. The purpose of the study is to investigate how teachers use and motivate the use of digital tools in the Mathematical education, and if and how the teachers say that they have made changes in their teaching due to the curriculum change. Five mathematics teachers working at senior high schools took part in semi-structured interviews and four mathematics classes were observed structurally. The result has been interpreted by using the framework RAT, Curriculum theory and ATD. The result shows that teachers use digital tools both as an equipment to reach the pupils mathematical understanding, but also as a goal for the pupils to learn the tools. The teachers motivate the use of digital tools by saying that it saves time, makes representations of concepts easier to show, and that it in some cases makes the teaching easier. They also say that digital tools can help introduce new ways of learning, that they prepare the pupils for national tests where they must be able to use digital tools, and that they prepare the pupils for a life in the world of digitalization. The teachers did none or a small change to their ways of teaching due to the curriculum change, and in that case, they said that they “opened up” more for the use of digital tools.
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