993 resultados para usability studies


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose: PTK787/ZK 222584 (PTK/ZK), an orally active inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases, inhibits VEGF-mediated angiogenesis. The pharmacodynamic effects of PTK/ZK were evaluated by assessing changes in contrast-enhancement parameters of metastatic liver lesions using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in patients with advanced colorectal cancer treated in two ongoing, dose-escalating phase I studies. Patients and Methods: Twenty-six patients had DCE-MRI performed at baseline, day 2, and at the end of each 28-day cycle. Doses of oral PTK/ZK ranged from 50 to 2000 mg once daily. Tumor permeability and vascularity were assessed by calculating the bidirectional transfer constant (Ki). The percentage of baseline Ki (% of baseline Ki) at each time point was compared with pharmacokinetic and clinical end points. Results: A significant negative correlation exists between the % of baseline Ki and increase in PTK/ZK oral dose and plasma levels (P = .01 for oral dose; P = .0001 for area under the plasma concentration curve at day 2). Patients with a best response of stable disease had a significantly greater reduction in Ki at both day 2 and at the end of cycle 1 compared with progressors (mean difference in % of baseline Ki, 47%, P = .004%; and 51%, P = .006; respectively). The difference in % of baseline Ki remained statistically significant after adjusting for baseline WHO performance status. Conclusion: These findings should help to define a biologically active dose of PTK/ZK. These results suggest that DCE-MRI may be a useful biomarker for defining the pharmacological response and dose of angiogenesis inhibitiors, such as PTK/ZK, for further clinical development. © 2003 by American Society of Clinical Oncology.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE To compare different reliability coefficients (exact agreement, and variations of the kappa (generalised, Cohen's and Prevalence Adjusted and Biased Adjusted (PABAK))) for four physiotherapists conducting visual assessments of scapulae. DESIGN Inter-therapist reliability study. SETTING Research laboratory. PARTICIPANTS 30 individuals with no history of neck or shoulder pain were recruited with no obvious significant postural abnormalities. MAIN OUTCOME MEASURES Ratings of scapular posture were recorded in multiple biomechanical planes under four test conditions (at rest, and while under three isometric conditions) by four physiotherapists. RESULTS The magnitude of discrepancy between the two therapist pairs was 0.04 to 0.76 for Cohen's kappa, and 0.00 to 0.86 for PABAK. In comparison, the generalised kappa provided a score between the two paired kappa coefficients. The difference between mean generalised kappa coefficients and mean Cohen's kappa (0.02) and between mean generalised kappa and PABAK (0.02) were negligible, but the magnitude of difference between the generalised kappa and paired kappa within each plane and condition was substantial; 0.02 to 0.57 for Cohen's kappa and 0.02 to 0.63 for PABAK, respectively. CONCLUSIONS Calculating coefficients for therapist pairs alone may result in inconsistent findings. In contrast, the generalised kappa provided a coefficient close to the mean of the paired kappa coefficients. These findings support an assertion that generalised kappa may lead to a better representation of reliability between three or more raters and that reliability studies only calculating agreement between two raters should be interpreted with caution. However, generalised kappa may mask more extreme cases of agreement (or disagreement) that paired comparisons may reveal.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Indigenous studies in First World nation states such as Australia, Canada, New Zealand, the United States of America and Hawaii, appear to have acquired the status of a discipline, although the accounts of its formation vary. Indigenous studies is formally recognised as part of university curricula in these countries and is included in inter‐disciplinary contexts and degree programs or is offered as a program and a degree in its own right. Indigenous scholarship is being published in unprecedented numbers with publishing houses competing for manuscripts. Indigenous studies journals have proliferated having emerged in the 1970s though most were, and continue to be, edited by non‐Indigenous people. In addition, Indigenous studies professional associations have been established organising research related activities as well as convening conferences to enable intellectual engagement and the formation of national and international networks. The nature and extent of this institutionalisation and the conditions of existence, though often marginalised and under resourced, may allude to the coherence of Indigenous Studies as a discipline with global reach but what remains unclear are its epistemological boundaries and the degree to which it perpetuates cultural entrapment . This paper will reflect on some of these epistemological matters.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To examine whether Chinese studies of child sexual abuse (CSA) in the general population show lower prevalence rates than other international studies, and whether certain features of these studies may help to account for variation in estimates. Methods: A meta-analysis and meta-regression were conducted on 27 studies found in the English and Chinese language peer reviewed journals that involved general populations of students or residents, estimated CSA prior to age 18, and specified rates for males or females individually. Results: Estimates for Chinese females were lower than the international composites. For total CSA for females, the Chinese pooled estimate was 15.3% (95% CI = 12.6–18.0) based on the meta-analysis of 24 studies, lower than the international estimate (Stoltenborgh, van IJzendoorn, Euser, & Bakermans-Kranenburg, 2011) but not significantly. For contact CSA for females, the pooled estimate was 9.5% (95% CI = 7.5–11.5), based on 16 studies, significantly lower than the international prevalence. For penetrative CSA for females, the pooled estimate was 1% (95% CI = 0.7–1.3), based on 15 studies, significantly lower than the international estimate of 15.1%. Chinese men reported significantly less penetrative CSA but significantly more total CSA than international estimates; while contact CSA reported by Chinese and international males appeared to be roughly equivalent. Chinese CSA prevalence estimates were lower in studies from urban areas and non-mainland areas (Hong Kong and Taiwan), and in surveys with larger and probability samples, multiple sites, face-to-face interview method and when using less widely used instruments. Conclusions: The findings to date justify further research into possible cultural and sociological reasons for lower risk of contact and penetrative sexual abuse of girls and less penetrative abuse of boys in China. Future research should examine sociological explanations, including patterns of supervision, sexual socialization and attitudes related to male sexual prowess. Practice implications: The findings suggest that future general population studies in China should use well validated instruments, avoid face-to-face interview formats and be careful to maintain methodological standards when sampling large populations over multiple sites.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Digital human modeling (DHM) systems underwent significant development within the last years. They achieved constantly growing importance in the field of ergonomic workplace design, product development, product usability, ergonomic research, ergonomic education, audiovisual marketing and the entertainment industry. They help to design ergonomic products as well as healthy and safe socio-technical work systems. In the domain of scientific DHM systems, no industry specific standard interfaces are defined which could facilitate the exchange of 3D solid body data, anthropometric data or motion data. The focus of this article is to provide an overview of requirements for a reliable data exchange between different DHM systems in order to identify suitable file formats. Examples from the literature are discussed in detail. Methods: As a first step a literature review is conducted on existing studies and file formats for exchanging data between different DHM systems. The found file formats can be structured into different categories: static 3D solid body data exchange, anthropometric data exchange, motion data exchange and comprehensive data exchange. Each file format is discussed and advantages as well as disadvantages for the DHM context are pointed out. Case studies are furthermore presented, which show first approaches to exchange data between DHM systems. Lessons learnt are shortly summarized. Results: A selection of suitable file formats for data exchange between DHM systems is determined from the literature review.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Porn studies researchers in the humanities have tended to use different research methods from those in social sciences. There has been surprisingly little conversation between the groups about methodology. This article presents a basic introduction to textual analysis and statistical analysis, aiming to provide for all porn studies researchers a familiarity with these two quite distinct traditions of data analysis. Comparing these two approaches, the article suggests that social science approaches are often strongly reliable – but can sacrifice validity to this end. Textual analysis is much less reliable, but has the capacity to be strongly valid. Statistical methods tend to produce a picture of human beings as groups, in terms of what they have in common, whereas humanities approaches often seek out uniqueness. Social science approaches have asked a more limited range of questions than have the humanities. The article ends with a call to mix up the kinds of research methods that are applied to various objects of study.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Women’s Experimental Cinema provides lively introductions to the work of fifteen avant-garde women filmmakers, some of whom worked as early as the 1950s and many of whom are still working today. In each essay in this collection, a leading film scholar considers a single filmmaker, supplying biographical information, analyzing various influences on her work, examining the development of her corpus, and interpreting a significant number of individual films. The essays rescue the work of critically neglected but influential women filmmakers for teaching, further study, and, hopefully, restoration and preservation. Just as importantly, they enrich the understanding of feminism in cinema and expand the terrain of film history, particularly the history of the American avant-garde.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Intersex is the condition whereby an individual is born with biological features that are simultaneously perceived as male and female. Ranging from the ambiguous genitalia of the true 'hermaphrodite' to the 'mildly or internally intersexed', the condition may be as common as cleft palate. Like cleft palate, it is hidden and surgically altered, but for very different reasons. Intersex draws heavily on the personal testimony of intersexed individuals, their loved ones and medical carers. The impact of early sex-assignment surgery on an individual's later life is examined within the context of ethical and clinical questions. Harper challenges the conventional and radical 'treatment' of intersexuality through non-consensual infant sex-assignment surgery. In doing so, she exposes powerful myths, taboos and constructions of gender - the perfect phallus, a bi-polar model of gender and the infallibility of medical decisions. Handling sensitive material with care, this book deepens our understanding of a condition that has itself only been medically understood in recent years.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this age of rapidly evolving technology, teachers are encouraged to adopt ICTs by government, syllabus, school management, and parents. Indeed, it is an expectation that teachers will incorporate technologies into their classroom teaching practices to enhance the learning experiences and outcomes of their students. In particular, regarding the science classroom, a subject that traditionally incorporates hands-on experiments and practicals, the integration of modern technologies should be a major feature. Although myriad studies report on technologies that enhance students’ learning outcomes in science, there is a dearth of literature on how teachers go about selecting technologies for use in the science classroom. Teachers can feel ill prepared to assess the range of available choices and might feel pressured and somewhat overwhelmed by the avalanche of new developments thrust before them in marketing literature and teaching journals. The consequences of making bad decisions are costly in terms of money, time and teacher confidence. Additionally, no research to date has identified what technologies science teachers use on a regular basis, and whether some purchased technologies have proven to be too problematic, preventing their sustained use and possible wider adoption. The primary aim of this study was to provide research-based guidance to teachers to aid their decision-making in choosing technologies for the science classroom. The study unfolded in several phases. The first phase of the project involved survey and interview data from teachers in relation to the technologies they currently use in their science classrooms and the frequency of their use. These data were coded and analysed using Grounded Theory of Corbin and Strauss, and resulted in the development of a PETTaL model that captured the salient factors of the data. This model incorporated usability theory from the Human Computer Interaction literature, and education theory and models such as Mishra and Koehler’s (2006) TPACK model, where the grounded data indicated these issues. The PETTaL model identifies Power (school management, syllabus etc.), Environment (classroom / learning setting), Teacher (personal characteristics, experience, epistemology), Technology (usability, versatility etc.,) and Learners (academic ability, diversity, behaviour etc.,) as fields that can impact the use of technology in science classrooms. The PETTaL model was used to create a Predictive Evaluation Tool (PET): a tool designed to assist teachers in choosing technologies, particularly for science teaching and learning. The evolution of the PET was cyclical (employing agile development methodology), involving repeated testing with in-service and pre-service teachers at each iteration, and incorporating their comments i ii in subsequent versions. Once no new suggestions were forthcoming, the PET was tested with eight in-service teachers, and the results showed that the PET outcomes obtained by (experienced) teachers concurred with their instinctive evaluations. They felt the PET would be a valuable tool when considering new technology, and it would be particularly useful as a means of communicating perceived value between colleagues and between budget holders and requestors during the acquisition process. It is hoped that the PET could make the tacit knowledge acquired by experienced teachers about technology use in classrooms explicit to novice teachers. Additionally, the PET could be used as a research tool to discover a teachers’ professional development needs. Therefore, the outcomes of this study can aid a teacher in the process of selecting educationally productive and sustainable new technology for their science classrooms. This study has produced an instrument for assisting teachers in the decision-making process associated with the use of new technologies for the science classroom. The instrument is generic in that it can be applied to all subject areas. Further, this study has produced a powerful model that extends the TPACK model, which is currently extensively employed to assess teachers’ use of technology in the classroom. The PETTaL model grounded in data from this study, responds to the calls in the literature for TPACK’s further development. As a theoretical model, PETTaL has the potential to serve as a framework for the development of a teacher’s reflective practice (either self evaluation or critical evaluation of observed teaching practices). Additionally, PETTaL has the potential for aiding the formulation of a teacher’s personal professional development plan. It will be the basis for further studies in this field.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We write in response to the letter by Liu et al. [1] commenting on our article, ‘‘Mesenchymal Stem Cells Regulate Angiogenesis According to Their Mechanical Environment’’ [2]. The study by Liu et al. demonstrates that the commonly used endogeneous reference gene (ERG), b-actin, is upregulated by mechanical loading, indicating a potential bias in the determined target gene expression when normalizing to b-actin, such as in our report on unchanged vascular endothelial growth factor (VEGF) and hypoxia-inducible factors (HIF)-1a mRNA levels in mechanically loaded mesenchymal stem cells (MSCs).