832 resultados para video as a research tool
Resumo:
This project examines the effects of age, experience, and video-based feedback on the rate and type of safety-relevant events captured on video event recorders in the vehicles of three groups of newly licensed young drivers: 1. 14.5- to 15.5-year-old drivers who hold a minor school license (see Appendix A for the provisions of the Iowa code governing minor school licenses); 2. 16-year-old drivers with an intermediate license who are driving unsupervised for the first time; 3. 16-year-old drivers with an intermediate license who previously drove unsupervised for at least four months with a school license. METHODS: The young drivers’ vehicles were equipped with an event-triggered video recording device for 24 weeks. Half of the participants received feedback regarding their driving, and the other half received no feedback at all and served as a control group. The number of safety-relevant events per 1,000 miles (i.e., “event rate”) was analyzed for 90 participants who completed the study. RESULTS: On average, the young drivers who received the video-based intervention had significantly lower event rates than those in the control group. This finding was true for all three groups. An effect of experience was seen for drivers in the control group; the 16-year-olds with driving experience had significantly lower event rates than the 16-year-olds without experience. When the intervention concluded, an increase in event rate was seen for the school license holders, but not for either group of 16-year-old drivers. There is strong evidence that giving young drivers video-based feedback, regardless of their age or level of driving experience, is effective in reducing the rate of safety-relevant events relative to a control group who do not receive feedback. Specific comparisons with regard to age and experience indicated that the age of the driver did not have an effect on the rate of safety-events, while experience did. Young drivers with six months or more of additional experience behind the wheel had nearly half as many safety-relevant events as those without that experience.
Resumo:
We present MBIS (Multivariate Bayesian Image Segmentation tool), a clustering tool based on the mixture of multivariate normal distributions model. MBIS supports multichannel bias field correction based on a B-spline model. A second methodological novelty is the inclusion of graph-cuts optimization for the stationary anisotropic hidden Markov random field model. Along with MBIS, we release an evaluation framework that contains three different experiments on multi-site data. We first validate the accuracy of segmentation and the estimated bias field for each channel. MBIS outperforms a widely used segmentation tool in a cross-comparison evaluation. The second experiment demonstrates the robustness of results on atlas-free segmentation of two image sets from scan-rescan protocols on 21 healthy subjects. Multivariate segmentation is more replicable than the monospectral counterpart on T1-weighted images. Finally, we provide a third experiment to illustrate how MBIS can be used in a large-scale study of tissue volume change with increasing age in 584 healthy subjects. This last result is meaningful as multivariate segmentation performs robustly without the need for prior knowledge.
Resumo:
The Baby and the Couple provides an insider's view on how infant communication develops in the context of the family and how parents either work together as a team or struggle in the process. The authors present vignettes from everyday life as well as case studies from a longitudinal research project of infants and their parents interacting together in the Lausanne Trilogue Play (LTP), an assessment tool for very young families. Divided into three parts, the book focuses not only on the parents, but also on the infant's contribution to the family. Part 1 presents a case study of Lucas and his family, from infancy to age 5. With each chapter we see how, in the context of their families, infants learn to communicate with more than one person at a time. Part 2 explores how infants cope when their parents struggle to work together - excluding, competing or only connecting through their child. The authors follow several case examples from infancy through to early childhood to illustrate various forms of problematic co-parenting, along with the infant's derailed trajectory at different ages and stages. In Part 3, prevention and intervention models based on the LTP are presented. In addition to an overview of these programs, chapters are devoted to the Developmental Systems Consultation, which combines use of the LTP and video feedback, and a new model, Reflective Family Play, which allows whole families to engage in treatment. The Baby and the Couple is a vital resource for professionals working in the fields of infant and preschool mental health including psychiatrists, psychologists, social workers, family therapists and educators, as well as researchers.
Resumo:
Soluble MHC-peptide complexes, commonly known as tetramers, allow the detection and isolation of antigen-specific T cells. Although other types of soluble MHC-peptide complexes have been introduced, the most commonly used MHC class I staining reagents are those originally described by Altman and Davis. As these reagents have become an essential tool for T cell analysis, it is important to have a large repertoire of such reagents to cover a broad range of applications in cancer research and clinical trials. Our tetramer collection currently comprises 228 human and 60 mouse tetramers and new reagents are continuously being added. For the MHC II tetramers, the list currently contains 21 human (HLA-DR, DQ and DP) and 5 mouse (I-A(b)) tetramers. Quantitative enumeration of antigen-specific T cells by tetramer staining, especially at low frequencies, critically depends on the quality of the tetramers and on the staining procedures. For conclusive longitudinal monitoring, standardized reagents and analysis protocols need to be used. This is especially true for the monitoring of antigen-specific CD4+ T cells, as there are large variations in the quality of MHC II tetramers and staining conditions. This commentary provides an overview of our tetramer collection and indications on how tetramers should be used to obtain optimal results.
Resumo:
Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyacids naturally synthesized in bacteria as a carbon reserve. PHAs have properties of biodegradable thermoplastics and elastomers and their synthesis in crop plants is seen as an attractive system for the sustained production of large amounts of polymers at low cost. A variety of PHAs having different physical properties have now been synthesized in a number of transgenic plants, including Arabidopsis thaliana, rape and corn. This has been accomplished through the creation of novel metabolic pathways either in the cytoplasm, plastid or peroxisome of plant cells. Beyond its impact in biotechnology, PHA production in plants can also be used to study some fundamental aspects of plant metabolism. Synthesis of PHA can be used both as an indicator and a modulator of the carbon flux to pathways competing for common substrates, such as acetyl-coenzyme A in fatty acid biosynthesis or 3-hydroxyacyl-coenzyme A in fatty acid degradation. Synthesis of PHAs in plant peroxisome has been used to demonstrate changes in the flux of fatty acids to the beta-oxidation cycle in transgenic plants and mutants affected in lipid biosynthesis, as well as to study the pathway of degradation of unusual fatty acids.
Resumo:
This project was undertaken in coordination with the Environmental Assessment process on the Mt. Vernon Road Improvements project in Cedar Rapids, Iowa. The goal of the research was to determine the cost effectiveness of combined photo-imaging and computer animation as a presentation tool describing public road improvements. The Public Hearing, in combination with the involvement of a Citizen's Resource Group, afforded an opportunity to have an evaluation of the processes by interested citizens who were not familiar with engineering drawings or the construction industry. After the initial viewing of a draft version of the video, the Resource Group made recommendations to the staff developing the video. Discussion of these recommendations led to the development of an animated composite section that showed a combination of situations typically encountered throughout the project corridor, as well as critical considerations. The composite section did not show specific locations and therefore, individuals were not distracted by looking for the details pertaining to their properties. Concentration on the concepts involved rather than specifics provided the opportunity for a more thorough understanding by the citizens. The development of the composite concept was the primary discovery of the research.
Resumo:
Commercially available instruments for road-side data collection take highly limited measurements, require extensive manual input, or are too expensive for widespread use. However, inexpensive computer vision techniques for digital video analysis can be applied to automate the monitoring of driver, vehicle, and pedestrian behaviors. These techniques can measure safety-related variables that cannot be easily measured using existing sensors. The use of these techniques will lead to an improved understanding of the decisions made by drivers at intersections. These automated techniques allow the collection of large amounts of safety-related data in a relatively short amount of time. There is a need to develop an easily deployable system to utilize these new techniques. This project implemented and tested a digital video analysis system for use at intersections. A prototype video recording system was developed for field deployment. A computer interface was implemented and served to simplify and automate the data analysis and the data review process. Driver behavior was measured at urban and rural non-signalized intersections. Recorded digital video was analyzed and used to test the system.
Resumo:
Genotype-based algorithms are valuable tools for the identification of patients eligible for CCR5 inhibitors administration in clinical practice. Among the available methods, geno2pheno[coreceptor] (G2P) is the most used online tool for tropism prediction. This study was conceived to assess if the combination of G2P prediction with V3 peptide net charge (NC) value could improve the accuracy of tropism prediction. A total of 172 V3 bulk sequences from 143 patients were analyzed by G2P and NC values. A phenotypic assay was performed by cloning the complete env gene and tropism determination was assessed on U87_CCR5(+)/CXCR4(+) cells. Sequences were stratified according to the agreement between NC values and G2P results. Of sequences predicted as X4 by G2P, 61% showed NC values higher than 5; similarly, 76% of sequences predicted as R5 by G2P had NC values below 4. Sequences with NC values between 4 and 5 were associated with different G2P predictions: 65% of samples were predicted as R5-tropic and 35% of sequences as X4-tropic. Sequences identified as X4 by NC value had at least one positive residue at positions known to be involved in tropism prediction and positive residues in position 32. These data supported the hypothesis that NC values between 4 and 5 could be associated with the presence of dual/mixed-tropic (DM) variants. The phenotypic assay performed on a subset of sequences confirmed the tropism prediction for concordant sequences and showed that NC values between 4 and 5 are associated with DM tropism. These results suggest that the combination of G2P and NC could increase the accuracy of tropism prediction. A more reliable identification of X4 variants would be useful for better selecting candidates for Maraviroc (MVC) administration, but also as a predictive marker in coreceptor switching, strongly associated with the phase of infection.
Resumo:
Visualization is a relatively recent tool available to engineers for enhancing transportation project design through improved communication, decision making, and stakeholder feedback. Current visualization techniques include image composites, video composites, 2D drawings, drive-through or fly-through animations, 3D rendering models, virtual reality, and 4D CAD. These methods are used mainly to communicate within the design and construction team and between the team and external stakeholders. Use of visualization improves understanding of design intent and project concepts and facilitates effective decision making. However, visualization tools are typically used for presentation only in large-scale urban projects. Visualization is not widely accepted due to a lack of demonstrated engineering benefits for typical agency projects, such as small- and medium-sized projects, rural projects, and projects where external stakeholder communication is not a major issue. Furthermore, there is a perceived high cost of investment of both financial and human capital in adopting visualization tools. The most advanced visualization technique of virtual reality has only been used in academic research settings, and 4D CAD has been used on a very limited basis for highly complicated specialty projects. However, there are a number of less intensive visualization methods available which may provide some benefit to many agency projects. In this paper, we present the results of a feasibility study examining the use of visualization and simulation applications for improving highway planning, design, construction, and safety and mobility.
Resumo:
Visualization is a relatively recent tool available to engineers for enhancing transportation project design through improved communication, decision making, and stakeholder feedback. Current visualization techniques include image composites, video composites, 2D drawings, drive-through or fly-through animations, 3D rendering models, virtual reality, and 4D CAD. These methods are used mainly to communicate within the design and construction team and between the team and external stakeholders. Use of visualization improves understanding of design intent and project concepts and facilitates effective decision making. However, visualization tools are typically used for presentation only in large-scale urban projects. Visualization is not widely accepted due to a lack of demonstrated engineering benefits for typical agency projects, such as small- and medium-sized projects, rural projects, and projects where external stakeholder communication is not a major issue. Furthermore, there is a perceived high cost of investment of both financial and human capital in adopting visualization tools. The most advanced visualization technique of virtual reality has only been used in academic research settings, and 4D CAD has been used on a very limited basis for highly complicated specialty projects. However, there are a number of less intensive visualization methods available which may provide some benefit to many agency projects. In this paper, we present the results of a feasibility study examining the use of visualization and simulation applications for improving highway planning, design, construction, and safety and mobility.
Resumo:
BACKGROUND: Excessive drinking is a major problem in Western countries. AUDIT (Alcohol Use Disorders Identification Test) is a 10-item questionnaire developed as a transcultural screening tool to detect excessive alcohol consumption and dependence in primary health care settings. OBJECTIVES: The aim of the study is to validate a French version of the Alcohol Use Disorders Identification Test (AUDIT). METHODS: We conducted a validation cross-sectional study in three French-speaking areas (Paris, Geneva and Lausanne). We examined psychometric properties of AUDIT as its internal consistency, and its capacity to correctly diagnose alcohol abuse or dependence as defined by DSM-IV and to detect hazardous drinking (defined as alcohol intake >30 g pure ethanol per day for men and >20 g of pure ethanol per day for women). We calculated sensitivity, specificity, positive and negative predictive values and Receiver Operator Characteristic curves. Finally, we compared the ability of AUDIT to accurately detect "alcohol abuse/dependence" with that of CAGE and MAST. RESULTS: 1207 patients presenting to outpatient clinics (Switzerland, n = 580) or general practitioners' (France, n = 627) successively completed CAGE, MAST and AUDIT self-administered questionnaires, and were independently interviewed by a trained addiction specialist. AUDIT showed a good capacity to discriminate dependent patients (with AUDIT > or =13 for males, sensitivity 70.1%, specificity 95.2%, PPV 85.7%, NPV 94.7% and for females sensitivity 94.7%, specificity 98.2%, PPV 100%, NPV 99.8%); and hazardous drinkers (with AUDIT > or =7, for males sensitivity 83.5%, specificity 79.9%, PPV 55.0%, NPV 82.7% and with AUDIT > or =6 for females, sensitivity 81.2%, specificity 93.7%, PPV 64.0%, NPV 72.0%). AUDIT gives better results than MAST and CAGE for detecting "Alcohol abuse/dependence" as showed on the comparative ROC curves. CONCLUSIONS: The AUDIT questionnaire remains a good screening instrument for French-speaking primary care.
Resumo:
Un treball final de carrera (TFC) és un dels últims passos de molts estudis, com per exemple els graus d'enginyeria. Els estudiants solen presentar els resultats del seu projecte final en una presentació pública, on un comitè avalua el seu treball. Els estudiants, en aquesta activitat, s'ocupen de competències com ara: fer presentacions orals efectives en entorns públics, en una situació estressant. Però, es pot assolir aquesta competència en un entorn virtual?A la Universitat Oberta de Catalunya (UOC), una universitat 100% virtual, es proposa una solució basada en les presentacions en vídeo que es pugen en una eina, Present@, que els permet compartir les presentacions i permet fer preguntes i escriure les respostes en un entorn obert.Present@ ofereix una eina millorada per pujar vídeos, que simplifica el procés i fa que sigui apropiada per als estudiants de qualsevol àrea de coneixement. Però treballar amb vídeos va un pas més enllà i requereix també la tecnologia adequada per donar suport a aquest tipus d'arxius. Així, s'ha afegit al Present@ un servei d'"streaming", Kaltura. Amb aquest servei els estudiants poden pujar fàcilment gairebé qualsevol format de vídeo i és possible fer comentaris en vídeo.131 estudiants han estat usant el Present@ durant 4 semestres. Per avaluar l'eina, els estudiants han contestat un qüestionari i de les respostes rebudes es conclou que aquest enfocament permet als estudiants virtuals adquirir la major part de les competències relacionades amb el TFC i, en concret, amb la dissertació virtual en entorns virtuals. Potser l'única característica a què no s'enfronten és la tensió de les preguntes.És important assenyalar que, gràcies a les millores introduïdes, el Present@ està present, actualment en més de 100 aules a UOC i s'utilitza no només per al TFC, sinó també per explicar assignatures per ajudar els estudiants
Resumo:
Avoimesta innovaatiosta ja innovaatioiden tehokkaasta hyödyntämisestä on tulossa tärkeitä osia yritysten T&K-prosesseihin. Diplomityön tarkoituksena on luoda viitekehys teknologioiden, jotka eivät kuulu yrityksen ydinliiketoimintaan, tehokkaampaan hallinnointiin tutkimusorganisaatiossa. Konstruktiivinen viitekehys on rakennettu pohjautuen aineettomien pääomien johtamisen ja portfolion hallinnoinnin teorioihin. Lisäksi työssä määritellään työkaluja jatekniikoita ylijäämäteknologioiden arviointiin. Uutta ylijäämäteknologioiden portfoliota voidaan hyödyntää hakukoneena, ideapankkina, kommunikaatiotyökaluna tai teknologioiden markkinapaikkana. Sen johtaminen koostuu tietojen dokumentoinnista järjestelmään, teknologioiden arvioinnista ja portfolion päivityksestä ja ylläpidosta.
Resumo:
Statistics has become an indispensable tool in biomedical research. Thanks, in particular, to computer science, the researcher has easy access to elementary "classical" procedures. These are often of a "confirmatory" nature: their aim is to test hypotheses (for example the efficacy of a treatment) prior to experimentation. However, doctors often use them in situations more complex than foreseen, to discover interesting data structures and formulate hypotheses. This inverse process may lead to misuse which increases the number of "statistically proven" results in medical publications. The help of a professional statistician thus becomes necessary. Moreover, good, simple "exploratory" techniques are now available. In addition, medical data contain quite a high percentage of outliers (data that deviate from the majority). With classical methods it is often very difficult (even for a statistician!) to detect them and the reliability of results becomes questionable. New, reliable ("robust") procedures have been the subject of research for the past two decades. Their practical introduction is one of the activities of the Statistics and Data Processing Department of the University of Social and Preventive Medicine, Lausanne.
Resumo:
The major task of policy makers and practitioners when confronted with a resource management problem is to decide on the potential solution(s) to adopt from a range of available options. However, this process is unlikely to be successful and cost effective without access to an independently verified and comprehensive available list of options. There is currently burgeoning interest in ecosystem services and quantitative assessments of their importance and value. Recognition of the value of ecosystem services to human well-being represents an increasingly important argument for protecting and restoring the natural environment, alongside the moral and ethical justifications for conservation. As well as understanding the benefits of ecosystem services, it is also important to synthesize the practical interventions that are capable of maintaining and/or enhancing these services. Apart from pest regulation, pollination, and global climate regulation, this type of exercise has attracted relatively little attention. Through a systematic consultation exercise, we identify a candidate list of 296 possible interventions across the main regulating services of air quality regulation, climate regulation, water flow regulation, erosion regulation, water purification and waste treatment, disease regulation, pest regulation, pollination and natural hazard regulation. The range of interventions differs greatly between habitats and services depending upon the ease of manipulation and the level of research intensity. Some interventions have the potential to deliver benefits across a range of regulating services, especially those that reduce soil loss and maintain forest cover. Synthesis and applications: Solution scanning is important for questioning existing knowledge and identifying the range of options available to researchers and practitioners, as well as serving as the necessary basis for assessing cost effectiveness and guiding implementation strategies. We recommend that it become a routine part of decision making in all environmental policy areas.