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Empirisk Modellering av Trafikflöden : En spatio-temporal prediktiv modellering av trafikflöden i Stockholms stad med hjälp av neurala nätverk / Empirical Modeling of Traffic Flow : A spatio-temporal prediction model of the traffic flow in Stockholm city using neural networksBjörkqvist, Niclas, Evestam, Viktor January 2024 (has links)
A better understanding of the traffic flow in a city helps to smooth transport resulting in a better street environment, affecting not only road users and people in proximity. Good predictions of the flow of traffic helps to control and further develop the road network in order to avoid congestion and unneccessary time spent while traveling. This study investigates three different machine learning models with the purpose of predicting traffic flow on different road types inurban Stockholm using loop sensor data between 2013 and 2023. The models used was Long short term memory (LSTM), Temporal convolutional network (TCN) and a hybrid model of LSTM and TCN. The results from the hybrid model indicates a slightly better mean absolute error than TCN suggesting that a hybrid model might be advantagous when predicting traffic flow using loop sensor data. LSTM struggled to capture the complexity of the data and was unable to provide a proper prediction as a result. TCN produced a mean absolute error slightly bigger than the hybrid model and was to an extent able to capture the trends of the traffic flow, but struggled with capturing the scale of the traffic flow suggesting the need for further data preprocessing. Furthermore, this study suggests that the loop sensor data was able to act as a foundation for predicting the traffic flow using machine learning methods. However, it suggest that improvements to the data itself such as incorporating more related parameters might be advantageous to further improve traffic flow prediction.
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The role of short-term starvation in sensitizing breast cancer to chemotherapyGovender, Yogeshni 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Introduction: Breast cancer is a major contributor to mortality in women worldwide. Although, anthracyclines, such as doxorubicin, are among the most valuable treatments for breast cancer, their clinical use is limited due to detrimental side-effects such as cardiotoxicity. Additionally, evidence suggests that cancer cells are becoming increasingly resistant to chemotherapeutic agents. The consequence of poor vascularisation within tumours subsequently leads to a nutrient deprived microenvironment which cancer cells are known to adapt to via metabolic remodelling and increasing autophagy. Autophagy is an intracellular degradation system, which is induced as a survival mechanism in response to starvation and other environmental stressors. Recent studies have shown that starvation protects non-tumourigenic cells against chemotherapy-induced cell death. Furthermore, patients who starved prior to chemotherapy reported reduced side-effects. However, these studies investigated the effects of long-term starvation, which maybe clinically challenging. Therefore, this concept, under shorter and more tolerable periods of starvation still needs to be investigated. We hypothesis, that short-term starvation will sensitize breast cancer cells to doxorubicin-induced cell death. In order to test this hypothesis this study was approached by the following aims: (i) to establish a time point at which MCF12A breast epithelial cells are protected against starvation; (ii) to determine the effect of short-term starvation on doxorubicin induced cell death; (iii) to assess autophagy and; (iv) to assess these above mentioned aims using an in vivo model.
Methods: MDAMB231 cells and MCF12A cells were starved for 0, 3, 6, 12, 24 and 48 hours using Hanks Balanced Salt Solution. Cell viability was assessed using the trypan blue, MTT and Caspase-Glo assays. MDAMB231 cells and MCF12A cells were subjected to the following conditions: (1) control; (2) 5 μM doxorubicin; (3) starvation of 3 hours and (4) a combination of starvation and doxorubicin. Following treatment an MTT assay to assess cell viability was performed. MDAMB231 cells were further examined using Live-Cell Imaging and western blot analysis. C57BL6 tumour bearing mice were treated with doxorubicin (5 mg/kg) or in combination with starvation of 24 hours. Upon termination of the protocol, tumour tissue was assessed using western blot analysis. In both in vitro and in vivo analyses cleaved-caspase 3 and cleaved-PARP were used as markers for apoptosis, LC3 and p62 as autophagic markers and p-AMPK and p-mTOR as markers of oxygen and energy sensing, respectively.
Results and discussion: Three hours of starvation was chosen for in vitro experiments since no significant reduction in cell viability or increases in apoptosis occurred at this time-point in the normal MCF12A breast epithelial cells. As expected, doxorubicin induced a significant decrease in cell viability in the cancerous MDAMB231 cells. Short-term starvation in combination with doxorubicin treatment caused a further significant decrease in cell viability in MDAMB231 cells compared to the doxorubicin group alone. Interestingly, starved MCF12A cells were protected against doxorubicin-induced cytotoxicity as cell viability significantly increased. A significant decrease in autophagy was further observed with the combined treatment of doxorubicin and starvation which corresponded with a significant increase in cell death. In contrast, although the in vivo study also demonstrated a significant elevation in cell death and autophagy in response to doxorubicin treatment, the combined treatment (starvation and doxorubicin) did not have an additive effect when compared to the doxorubicin group alone. Conclusion: Our in vitro results clearly demonstrate that short-term starvation sensitizes breast cancer cells to doxorubicin-induced cell death. Additionally, decreased levels of autophagy appear to contribute to this phenomenon of sensitization. Although doxorubicin treatment resulted in increased apoptosis in vivo, 24 hours starvation in combination with doxorubicin did not sensitize the tumours to doxorubicin treatment. Thus, for future in vivo studies more time points should be considered in order to translate the beneficial effects of short-term starvation observed in our in vitro study to an animal model. / AFRIKAANSE OPSOMMING: Inleiding: Borskanker is ‘n belangrike faktor wat bydrae tot sterftes in vrouens wêreldwyd. Alhoewel antrasikliene soos doxorubicin, waardevol is vir die behandeling van borskanker, word die kliniese gebruik daarvan beperk deur newe-effekte soos kardiotoksisiteit. Verder, word daar al hoe meer bewys dat kankerselle toenemend weeerstandbiedend word teen chemoterapeutiese middels. Swak vaskularisasie van tumore lei tot ‘n mikro-omgewing met beperkte voedingstowwe waaby kankerselle kan aanpas deur middel van metaboliese hermodelering en ‘n toename in autofagie. Autofagie is ‘n intrasellulêre degraderingsisteem wat as ‘n oorlewingsmeganisme aangewend word tydens verhongering en ander omgewingstressors. Onlangse studies het getoon dat verhongering nie-tumourigeniese (normale) selle teen chemoterapie-geïnduseerde seldood beskerm. Verder is daar ook geraporteer dat pasiënte wat gevas het voor chemoterapie, verminderde newe-effekte getoon het. Hierdie studies het egter gefokus op ‘n relatief lang-termyn vas, wat klinies nogal uitdagend kan wees. Daarom moet hierdie konsep nog op korter, meer hanteerbare tye getoets word. Ons hipotese is dus dat kort-termyn vas borskankerselle kan sensitiseer tot doxorubicin-geïnduseerde seldood. Om hierdie hipotese te toets, is die volgende doelwitte gestel: (i) om ‘n tydspunt te bepaal waar MCF12A borsepiteelselle beskerm is teen verhongering; (ii) om die effek van kort-termyn verhongering op doxorubicin-geïnduseerde seldood te toets; (iii) om autofagie te karakteriseer in ons model en; (iv) om hierdie doelwitte ook in ‘n in vivo model te toets.
Metodes: MDAMB231 en MCF12A selle is verhonger vir 0, 3, 6, 12, 24 and 48 ure deur van Hanks se gebalanseerde soutoplossing gebruik te maak. Sellewensvatbaarheid is bepaal deur middel van trypan blou, MTT en die Caspase-Glo tegnieke. MDAMB231 en MCF12A selle is onderwerp aan die volgende omstandighede: (1) kontrole; (2) 5 μM doxorubicin; (3) verhongering van 3 ure en (4) ‘n kombinasie van verhongering en doxorubicin. Na behandeling is die sellewensvatbaarheid deur middel van die MTT tegniek bepaal. MDAMB231 selle is verder ondersoek deur middel van “Live-Cell Imaging” en die westelike klad tegniek. C57BL6 tumor-draende muise is behandel met doxorubicin (5 mg/kg) of met ‘n kombinasie van verhongering van 24 ure en doxorubicin. Aan die einde van die protokol, is die kankerweefsel geanaliseer deur die westelike klad tegniek. In beide in vitro en in vivo analises, is gekliefde- caspase 3 en -PARP as merkers vir apoptose, LC3 and p62 as merkers vir autofagie en p-AMPK en p-mTOR as suurstof- en energie sensors respektiewelik gemeet.
Resultate en bespreking: Vir die in vitro eksperimente, is ‘n tydspunt van 3 ure gekies as gevolg van die feit dat geen afname in sellewensvatbaarheid en ‘n toename in apoptose in hierdie tydsgleuf tydens verhongering in die normale MCF12A borsepiteelselle plaasgevind het nie. Soos verwag, het doxorubicin behandeling ‘n insiggewende afname in sellewensvatbaarheid in die kankeragtige MDAMB231 selle veroorsaak. Die kombinasie-terapie van verhongering en doxorubicin het ‘n verdere verhoging in seldood teweeg gebring in die MDAMB231 selle, maar het die normale MCF12A borsepiteelselle teen doxorubicin-geïnduseerde toksisiteit beskerm. Die kombinasie-behandeling is ook geassosieer met ‘n afname in autofagie. Alhoewel, die in vivo studie ook getoon het dat doxorubicin alleen insiggewende hoeveelheid seldood teweeggebring het, het die kombinasie-behandeling nie die additiewe effek, soos in die in vitro studie, teweeg gebring nie. Gevolgtrekking: Die in vitro resultate het duidelik getoon dat kort-termyn verhongering borskankerselle kan sensitiseer vir doxorubicin terapie. Verder het dit geblyk dat ‘n afname in autofagie tot die fenomeen van sensitisering bygedrae het. Alhoewel doxorubicin behandeling in vivo tot ‘n toename in apoptose in die tumor gelei het, het die kombinasie behandeling nie die kankerweefsel ten op sigte van doxorubicin gesensitiseer nie. Daar sal dus vir toekomstige in vivo studies meer tydsgleuwe van behandeling ondersoek moet word om die optimum verhongeringsperiode te vind sodat die in vitro resultate ook in vivo van toepassing kan wees. / NRF and CANSA for financial support
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Samhörighet - Är det en lyx endast fastanställda upplever?Åbrink, Sara, Bruno, Sandra January 2015 (has links)
Problem: Antalet bemanningsföretag har ökat genom åren. De passar in på dagens önskan om mer effektivisering och en snabbare anpassning till marknadens efterfrågan. Men hur påverkas egentligen företagskulturen och känner korttidsanställda gemenskap och samhörighet med de fastanställda? Syfte: Syftet med vår studie är att öka förståelsen kring korttidsanställdas arbetssituation, hur de ser på frågan om samhörighet på arbetsplatsen och om de är en del av företagskulturen. Metod: Studien utgår från en kvalitativ metod med telefonintervjuer med tio respondenter från ett bemanningsföretag. Slutsatser: Sammanfattningsvis hamnar många korttidsanställda utanför företagskulturen och känner ingen samhörigheten med de fastanställda inom företaget
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Encountering Distant Suffering: The Culture, Production, and Outcomes of Transnational Immersion Trips on the U.S.-Mexico BorderAdler, Gary John Jr. January 2012 (has links)
Short-term international immersion travel connects participants from educational and religious organizations with distant suffering to build solidarity and motivate transnational civic action. It is a distinct form of transnational social action that produces a personalized, embodied experience of transformation. Despite increasing popularity, and increasing evidence that this form of travel can facilitate civic action and activism, the mechanisms behind the production, experience, and outcomes are not well known. This research examines these issues through a focus on multiple cultural processes. The research site is BorderLinks, a faith-affiliated organization that promotes immigration awareness through travel along the U.S.-Mexico border. I use participant observation with different groups (colleges, seminaries, churches), pre/post surveys with 180 participants, and interviews with participants to examine why individuals participate, how transformative experience is produced, how group styles stabilize this moment of unsettledness, the difficulties of solidarity formation, and the specific patterns of outcomes. Short-term international immersion travel is a cultural strategy of transformation that provides participants with identity shaping experiences and fits the goals of feeder organizations that prioritize personal transformation and social engagement. Recruitment through feeder organizations creates groups with distinct demographic profiles, motivational repertoires, and emotional orientations: the "toolkits of travel." An immersion trip sits in a liminal space of culture, yet the institutional origins of groups generate group styles that guide groups through this unsettledness (Eliasoph and Lichterman 2003). Some groups "sleuth" while others "story build," resulting in different imaginations of possible future action. The encounter with migrants addresses a central question of how solidarity between international travelers and distant suffering is formed. I show the importance of two strategies of solidarity, one relational and one imaginative. Through a hike in the desert, I show the conditions for producing evoking symbols that moralize the experience into the future. I examine change in economic behavior, attitudes, and some civic activity. I use Qualitative Comparative Analysis to show which aspects of immersion travel are most responsible for change: emotional intensification, moralized situations, cognitive awareness, and/or group affiliation. For participants' narrative construction, differences in group use of reflexivity resources affect the moral extension into the future.
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A naïve sampling model of intuitive confidence intervalsHansson, Patrik January 2007 (has links)
A particular field in research on judgment and decision making (JDM) is concerned with realism of confidence in one’s knowledge. An interesting finding is the so-called format dependence effect, which implies that assessment of the same probability distribution generates different conclusions about over- or underconfidence depending on the assessment format. In particular, expressing a belief about some unknown continuous quantity (e.g., a stock value) in the form of an intuitive confidence interval is severely prone to overconfidence as compared to expressing the belief as an assessment of a probability judgment. This thesis gives a tentative account of this finding in terms of a Naïve Sampling Model, which assumes that people accurately describe their available information stored in memory, but they are naïve in the sense that they treat sample properties as proper estimators of population properties (Study 1). The effect of this naivety is directly investigated empirically in Study 2. A prediction that short-term memory is a constraining factor for sample size in judgment, suggesting that experience per se does not eliminate overconfidence is investigated and verified in Study 3. Age-related increments in overconfidence were observed with intuitive confidence interval but not for probability judgment (Study 4). This thesis suggests that no cognitive processing bias (e.g., Tversky & Kahneman, 1974) over and above naivety is needed to understand and explain the overconfidence “bias” with intuitive confidence interval and hence the format dependence effect.
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Primary school children's processes of emotional expression and negotiation of power in an expressive arts curricular projectHiggins, Hillarie Jean January 2010 (has links)
Therapeutic education initiatives embodying a whole child approach can be seen to address the intellectual, emotional, bodily and spiritual as being part of a child’s educational self. Through designing and implementing the concept of “aesthetic life narratives” in a primary school classroom, my research produces a curricular example of how therapeutic notions such as those found in psychological thought can be integrated into contemporary Scottish education through narrative and aesthetic means, exemplifying how individual children can make sense of expressive processes and roles introduced to them in an educational context. The specific characteristics of the research space and the particular interactive quality of research participation also illustrate how different children are able to participate in a short-term emotional education intervention specifically designed to be empowering. At the same time, my experience shows that the complex dynamic between the subjective life of a researcher and the historical nature of a child’s experience with caregivers in their home life can shape educational/research experience, as well as its adult and child participants, in ways unanticipated. What transpired in the process of applying philosophical ideas to the real lives of children in my research produced ethical implications regarding critical reflexivity and the socio-cultural regard of the child that are of wider relevance to educators, researchers, counsellors and policy makers who interact with children in their own work.
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Optimierung der Schaftkomponente von Kurzschaftendoprothesen mittels Finite-Elemente-AnalyseKleinschrodt, Claudia, Alber-Laukant, Bettina, Rieg, Frank, Simank, Hans-Georg 10 December 2016 (has links) (PDF)
Einleitung
2015 belegte die Implantation einer Endoprothese am Hüftgelenk mit 219.325 Operationen Platz 8 der 50 häufigsten Operationen der vollstationären Patienten in Krankenhäusern (DRG-Statistik 2015). Bei diesen Eingriffen kommt eine Vielzahl von verschiedenen Prothesenmodellen zum Einsatz (Kirschner 2005). Aktuell geht der Trend in Richtung zementfreie Verankerung, Verkleinerung der Implantate und den Erhalt von möglichst viel Knochensubstanz (Jerosch 2013). So werden in den letzten Jahren immer häufiger Kurzschaftendoprothesen implantiert (Jerosch 2013). Sie stellen ein knochensparendes System dar und erlauben gleichzeitig verschiedene Gleitpaarungen (Jerosch 2013). Allerdings liegen für die meisten Kurzschaftendoprothesentypen noch keine Langzeittestergebnisse vor (Jerosch 2011), so dass das Langzeitverhalten dieser Prothesen nicht vorhergesagt werden kann. Speziell bei Kurzschaftendoprothesen ist der Einfluss der verkürzten Schaftlänge auf das Einwachsverhalten und die Lebensdauer des Implantats noch nicht ausreichend geklärt.
Am Lehrstuhl für Konstruktionslehre und CAD der Universität Bayreuth finden deshalb Untersuchungen zur computergestützten Analyse von Kurzschaftendoprothesen statt. Ziel hierbei ist es, durch eine Variation der Schaftlänge eine Prothesenform mit optimalen Spannungsverläufen und einer verbesserten Krafteinleitung in den Knochen zu entwickeln.
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Optimierung der Schaftkomponente von Kurzschaftendoprothesen mittels Finite-Elemente-Analyse [Präsentationsfolien]Kleinschrodt, Claudia, Simank, Hans-Georg, Alber-Laukant, Bettina, Rieg, Frank 20 December 2016 (has links) (PDF)
No description available.
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Automation of a DXA-based finite-element tool for clinical assessment of hip fracture riskAhmed, Sharif 12 October 2016 (has links)
Dual Energy X-ray Absorptiometry (DXA)-based finite element (FE) modelling has emerged as a potential tool for better assessment of osteoporotic hip fracture risk. Automation of this complex and computationally-intense procedure is the prime requirement for its clinical applicability. The aim of this study was to develop a fully automatic DXA-based finite element tool and assess its discrimination ability and short-term repeatability. The proximal femur was automatically segmented from clinical hip DXA scan and the subject-specific FE model was constructed for simulating sideways fall. Hip fracture risk indices (HFRIs) were calculated using two ways (along a femur cross-section and over a region of interest, ROI). Hip fracture discriminability increased when moved from femur cross-section based to ROI based HFRI calculation. A significant increase in hip fracture discriminability from baseline femoral neck and total hip bone mineral density (BMD) was achieved with ROI based HFRIs. Promising short-term repeatability was observed for HFRIs (coefficient of variation, CV, 3~3.5%). After removing representative poor cases, CVs were less than 3%. These preliminary results establish the potential of the proposed automatic tool for hip fracture risk assessment and justify large-scale clinical evaluation of its ability to predict incident hip fractures. / February 2017
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Représentation corticale de la mémoire à court-terme tactile chez l'humain pour une stimulation de la main : étude par magnétoencéphalographieFortier-Gauthier, Ulysse 08 1900 (has links)
L'activité cérébrale, reliée spécifiquement à la rétention d'information en mémoire à court-terme tactile, a été investiguée à l'aide de l'enregistrement des champs magnétiques produits par l'activité neuronale générée durant la période de rétention par une tâche de mémoire tactile. Une, deux, trois ou quatre positions, sur une possibilité de huit sur les phalangines et les phalangettes, de la main gauche ou droite, lors de blocs d'essai différents, ont été stimulées simultanément. Le patron de stimulation tactile devait être retenu pendant 1800 ms avant d'être comparé avec un patron test qui était, soit identique, soit différent par une seule position. Nos analyses se sont concentrées sur les régions du cerveau qui montraient une augmentation monotone du niveau d'activité soutenu durant la période de rétention pour un nombre croissant de positions à retenir dans le patron de stimulation. Ces régions ont plus de chance de participer à la rétention active de l'information à maintenir en mémoire à court-terme tactile. Le gyrus cingulaire (BA32), le gyrus frontal supérieur droit (BA 8), le precuneus gauche (BA 7, 19), le gyrus postcentral gauche (BA 7), le gyrus precentral droit (BA 6), le gyrus frontal supérieur gauche (BA 6) et le lobule pariétal inférieur droit (BA 40) semblent tous impliqués dans un réseau mnésique qui maintient les informations sensorielles tactiles dans un système de mémoire à court-terme spécialisé pour l'information tactile. / Brain activity specifically related to the maintenance of information held in tactile short-term memory was investigated, using recordings of magnetic fields from a whole-head magnetometer. This neuronal activity was measured during the retention interval of a tactile memory task. One, two, three, or four locations on distal and intermediate phalanges, out of eight positions, were simultaneously stimulated on the left or right hand in different blocks of trials. The tactile stimulation pattern was held in memory for 1800 ms before being compared with a test pattern that was either the same or different by one location. Our analyses focused on regions in the brain that showed a monotonic increase of the sustained activity levels during the retention interval with an increasing number of stimulated locations in the to-be-remembered pattern. These regions are the most likely to participate in the active retention of the information to be held in tactile sensory memory. The right cingular gyrus (BA 32), the right superior frontal gyrus (BA 8), the left precuneus (BA 7, 19), the left postcentral gyrus (BA 7), the right precentral gyrus (BA 6), the left superior frontal gyrus (BA 6) and the right inferior parietal lobule (BA 40) all appear to be involved in a memory system that maintains tactile sensory input in a short-term memory system specialized for tactile information.
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