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451.
Experimental evidence for improved neuroimaging interpretation using three-dimensional graphic models 总被引:1,自引:0,他引:1
Ruisoto P Juanes JA Contador I Mayoral P Prats-Galino A 《Anatomical sciences education》2012,5(3):132-137
Three-dimensional (3D) or volumetric visualization is a useful resource for learning about the anatomy of the human brain. However, the effectiveness of 3D spatial visualization has not yet been assessed systematically. This report analyzes whether 3D volumetric visualization helps learners to identify and locate subcortical structures more precisely than classical cross-sectional images based on a two dimensional (2D) approach. Eighty participants were assigned to each experimental condition: 2D cross-sectional visualization vs. 3D volumetric visualization. Both groups were matched for age, gender, visual-spatial ability, and previous knowledge of neuroanatomy. Accuracy in identifying brain structures, execution time, and level of confidence in the response were taken as outcome measures. Moreover, interactive effects between the experimental conditions (2D vs. 3D) and factors such as level of competence (novice vs. expert), image modality (morphological and functional), and difficulty of the structures were analyzed. The percentage of correct answers (hit rate) and level of confidence in responses were significantly higher in the 3D visualization condition than in the 2D. In addition, the response time was significantly lower for the 3D visualization condition in comparison with the 2D. The interaction between the experimental condition (2D vs. 3D) and difficulty was significant, and the 3D condition facilitated the location of difficult images more than the 2D condition. 3D volumetric visualization helps to identify brain structures such as the hippocampus and amygdala, more accurately and rapidly than conventional 2D visualization. This paper discusses the implications of these results with regards to the learning process involved in neuroimaging interpretation. 相似文献
452.
This paper presents a numerical study of DC-biased AC-electrokinetic (DC-biased ACEK) flow over a pair of symmetrical electrodes. The flow mechanism is based on a transverse conductivity gradient created through incipient Faradaic reactions occurring at the electrodes when a DC-bias is applied. The DC biased AC electric field acting on this gradient generates a fluid flow in the form of vortexes. To understand more in depth the DC-biased ACEK flow mechanism, a phenomenological model is developed to study the effects of voltage, conductivity ratio, channel width, depth, and aspect ratio on the induced flow characteristics. It was found that flow velocity on the order of mm/s can be produced at higher voltage and conductivity ratio. Such rapid flow velocity is one of the highest reported in microsystems technology using electrokinetics. 相似文献
453.
Andrade Mdos S De Lira CA Koffes Fde C Mascarin NC Benedito-Silva AA Da Silva AC 《Journal of sports sciences》2012,30(6):547-553
The purpose of this study was to determine differences in hamstrings-to-quadriceps (H/Q) peak torque ratios evaluated at different angular velocities between men and women who participate in judo, handball or soccer. A total of 166 athletes, including 58 judokas (26 females and 32 males), 39 handball players (22 females and 17 males), and 69 soccer players (17 females and 52 males), were evaluated using an isokinetic dynamometer. The H/Q isokinetic peak torque ratios were calculated at angular velocities of 1.05 rad · s?1 and 5.23 rad · s?1. In the analysis by gender, female soccer players produced lower H/Q peak torque ratios at 1.05 rad · s?1 than males involved in the same sport. However, when H/Q peak torque ratio was assessed at 5.23 rad · s?1, there were no significant differences between the sexes. In the analysis by sport, there were no differences among females at 1.05 rad · s?1. In contrast, male soccer players had significantly higher H/Q peak torque ratios than judokas (66 ± 12% vs. 57 ± 14%, respectively). Female handball players produced significantly lower peak torque ratios at 5.23 rad · s?1 than judokas or soccer players, whereas males presented no ratio differences among sports At 5.23 rad · s?1. In the analysis by velocity, women's muscular ratios assessed at 1.05 rad · s?1 were significantly lower than at 5.23 rad · s?1 for all sports; among men, only judokas presented lower ratios at 1.05 rad · s?1 than at 5.23 rad · s?1. The present results suggest that sport modality and angular velocity influence the isokinetic strength profiles of men and women. 相似文献
454.
This article provides an interpretation of a biblical text about the judge Gideon. It uses the hermeneutic method of research
to draw some evaluation patterns from this case study relating to the analysis of needs, the declaration of aims, the context
and circumstances of evaluation, the agents involved, the recruitment process, the assessment of evaluative evidence, the
results and the assessment report. 相似文献
455.
Antonio Gómez-Bolea Esteve Llop Xavier Ariño Cesareo Saiz-Jimenez Alessandra Bonazza Palmira Messina Cristina Sabbioni 《Journal of Cultural Heritage》2012,13(3):254-258
Several climate parameters affect the growth of organisms and, hence, their capacity to accumulate biomass. In the present research, we analyse the influence of two parameters, temperature and precipitation, on biomass accumulation on stone substrate, and propose a function to estimate it in temperate areas. The expression is subsequently used for the first time to evaluate the impact that climate change would have in biomass accumulation in Europe. The models on climate change predict an increase in temperature and precipitation in northern areas of Europe for the far future (2070–2099), which would lead to a higher accumulation of biomass. Otherwise, a significant reduction in precipitation is expected in southern areas of Europe, associated with a lower biomass accumulation in such areas. 相似文献
456.
Work performed under the SPElling Error Detection COrrection Project (SPEEDCOP) supported by National Science Foundation (NSF) at Chemical Abstracts Service (CAS) to devise effective automatic methods of detecting and correcting misspellings in scholarly and scientific text is described. The investigation was applied to 50,000 word/misspelling pairs collected from six datasets (Chemical Industry Notes (CIN), Biological Abstracts (BA). Chemical Abstracts (CA), Americal Chemical Society primary journal keyboarding (ACS), Information Science Abstracts (ISA), and Distributed On-Line Editing (DOLE) (a CAS internal dataset especially suited to spelling error studies). The purpose of this study was to determine the utility of trigram analysis in the automatic detection and/or correction of misspellings. Computer programs were developed to collect data on trigram distribution in each dataset and to explore the potential of trigram analysis for detecting spelling errors, verifying correctly-spelled words, locating the error site within a misspelling, and distinguishing between the basic kinds of spelling errors. The results of the trigram analysis were largely independent of the dataset to which it was applied but trigram compositions varied with the dataset. The trigram analysis technique developed determined the error site within a misspelling accurately, but did not distinguish effectively between different error types or between valid words and misspellings. However, methods for increasing its accuracy are suggested. 相似文献
457.
Marco Antonio Moreira 《Assessment & Evaluation in Higher Education》1983,8(3):234-245
First, the theory of directed graphs (digraphs) was used to map the conceptual structure of the content, implicit in the instructional materials, in the area of electricity at college level. After this, the graphical representation of content structure, thus obtained, was compared with those obtained for the teacher's cognitive structure and the student's cognitive structure through a word association test and the multidimensional scaling technique. Research findings suggest mainly that the techniques used to assess content and cognitive structures might be useful tools for such a purpose.
458.
459.
460.
Liney Manjarrés-Henríquez Antonio Gutiérrez-Gracia Andrés Carrión-García Jaider Vega-Jurado 《Research in higher education》2009,50(8):795-811
This paper evaluates whether university–industry relationships (UIR) and academic research activities have complementary effects
on the scientific production of university lecturers. The analysis is based on a case study of two Spanish universities. We
find that the effects of R&D contracts with industry, and academic research activity on scientific production are synergistic,
but only when the R&D contracts account for a low percentage of a lecturer’s total funding. This suggests that the positive
effect of UIR on a lecturer’s scientific production comes fundamentally from the capacity to provide complementary resources
(cognitive, technical, and/or financial) for research activities. If lecturers are not involved in research and dedicate most
their time to the development of activities related to UIR, their scientific production will be negatively affected. 相似文献