1,042 research outputs found
Vision loss following snakebite in a patient with controlled aplastic anemia
Viper venoms act mainly on blood and blood vessels. Reports of ophthalmic manifestations after snakebite include ptosis and ophthalmoplegia. In the current study, we describe a case that developed bilateral retinal and subretinal hemorrhage following snakebite. Bilateral retinal hemorrhage is a rare ocular complication of snake envenomation and has not been reported with fundus photographs in the literature so far
Stereoscopic bimanual interaction for 3D visualization
Virtual Environments (VE) are being widely used in various research fields for several decades such as 3D visualization, education, training and games. VEs have the potential to enhance the visualization and act as a general medium for human-computer interaction (HCI). However, limited research has evaluated virtual reality (VR) display technologies, monocular and binocular depth cues, for human depth perception of volumetric (non-polygonal) datasets. In addition, a lack of standardization of three-dimensional (3D) user interfaces (UI) makes it challenging to interact with many VE systems.
To address these issues, this dissertation focuses on evaluation of effects of stereoscopic and head-coupled displays on depth judgment of volumetric dataset. It also focuses on evaluation of a two-handed view manipulation techniques which support simultaneous 7 degree-of-freedom (DOF) navigation (x,y,z + yaw,pitch,roll + scale) in a multi-scale virtual environment (MSVE). Furthermore, this dissertation evaluates auto-adjustment of stereo view parameters techniques for stereoscopic fusion problems in a MSVE. Next, this dissertation presents a bimanual, hybrid user interface which combines traditional tracking devices with computer-vision based "natural" 3D inputs for multi-dimensional visualization in a semi-immersive desktop VR system. In conclusion, this dissertation provides a guideline for research design for evaluating UI and interaction techniques
Self-service technology: an investigation of the potential for adoption in apparel retail settings
This study investigates the potential for adoption of self-service technologies (SSTs) in the apparel retail environment. The importance of motivation factors (e.g., intrinsic vs. extrinsic) for adopting SSTs in the apparel retail environment is explored as is the moderating effect of familiarity in potential SST adoption. Data were collected via a self-administered questionnaire completed by undergraduate students at a large southeastern university. A total of 494 usable questionnaires were collected. Respondents were predominantly female (82.6%), and ages ranged from 18 to 57 years, with an average age of 22 years. The majority of participants were Caucasian/White and majoring in a business-related field. Measures were based on the existing literature and assessed using a 7-point Likert-type scale and a 7-point semantic differential scale. Because many apparel retail settings do not currently offer self-service technology, participants were provided a definition of SST and an apparel shopping scenario involving the use of SST prior to completing the survey. Structural equation modeling technique was employed via a LISREL 8.8 to test the hypotheses. Results obtained for the main effect of the conceptual model revealed a χ2 of 1283.14 (df = 339; p 2 / df = 3.79. A χ2 of 115.97 (df = 9; p 2 / df = 12.89 was revealed for the moderating effect. Results indicated that individuals who perceive SSTs to be personally enjoyable are likely to display a favorable attitude toward using SSTs in the apparel retail environment. In contrast, individuals with a general fear of using technology are less likely to exhibit a favorable attitude toward using SSTs. Regarding the extrinsic motivation factors, perceived usefulness was an important element affecting attitudes toward using SSTs. Results further suggested that individuals who believe that using SSTs would be personally enjoyable and would make the shopping task more efficient are likely to use SSTs when shopping for apparel products. Findings also indicate a significant moderating effect of familiarity with using SSTs on the relationship between technology anxiety and attitudes toward using SSTs. In other words, the influence of technology anxiety on attitudes toward using SSTs tend to be weaker in high levels of familiarity toward technology usage than in low levels of familiarity toward technology usage conditions. This study contributes to the growing knowledge base about consumers' shopping behaviors in relation to SSTs, and fills a gap in the literature about the potential for SST use in the apparel retail shopping environment. Findings can aid apparel retailers looking to enhance their service offerings by providing an additional means for customers to purchase merchandise in the store. Future research is needed that applies the model to different populations, different types of SSTs, and relative to different types of apparel retailers
Clothing gift expenditures : the influence of gender, ethnicity, and age
"The study's purpose was to understand better the role of clothing in gift giving, specifically to estimate the probabilities associated between gender, ethnicity, and age and CU (household) clothing and clothing gift expenditures, as well as to identify mean differences between CU clothing and clothing gift expenditures based on the gender, ethnicity, and age of CU heads. The study data were drawn from the 2001 Consumer Expenditure Survey (CEX) and probabilities were estimated using Bayesian statistical analysis. Analysis of variance (ANOVA) was used to test for mean expenditure differences. The findings indicated that male-headed CUs had a higher probability and higher mean expenditures relative to clothing and clothing gifts than female-headed CUs for the adult and infant clothing categories. African-American-headed CUs had the highest mean clothing expenditure for the adult and infant clothing categories, although Caucasian- and Hispanic-headed CUs had higher probabilities for purchasing clothing. CUs with heads 45~54 and 55~64 had the highest mean expenditures for adult clothing, while, CUs with heads 14~19 and 20~24 had the highest mean expenditures for infant clothing. A comparison of the study results and the literature suggests there may be differences between individual and CU expenditure behaviors relative to clothing and clothing gift giving."--Abstract from author supplied metadata
U.S. apparel retailers' international expansion: an application of the Uppsala model.
The purpose of this study is to elucidate U.S. apparel retailers' internationalization by proposing a theoretical framework that incorporates the antecedents of U.S. apparel retail firms' international market involvement and investigating the effects of international activities on firm performance. Data were collected via a self-administered questionnaire completed by U.S. apparel retailers nationwide. A total of 81 usable questionnaires were collected based on Dillman, Smyth, and Christian (2009)'s Mixed-mode Survey technique. The respondents were predominantly small firms (n = 76, 93.8%) that had fewer than 500 employees. Of these 81 firms, 30 firms currently sell their products or services outside the U.S. market. The first international market for half of the firms was Canada and more than half the firms had attained their first international sales via online (n = 16, 53.3%). Measures were assessed using a 7-point Likert-type scale, a dichotomous variable, and continuous variables. A series of regression models were performed to test all hypotheses. The results indicated that apparel retailers who have more foreign networking are likely to have market knowledge about foreign markets. Firm age and market knowledge (i.e., firm-specific factors) were found as significant factors in categorizing companies as being either involved or not involved in the international market of the apparel retail environment. The results further revealed that market knowledge mediates the relationship between foreign networking and international market involvement. The findings also indicated that although the effect is weak, apparel retailers that expanded internationally at younger ages are likely to demonstrate better firm performance in foreign markets compared to their counterparts. Firms who have had longer experience in foreign markets reveal better firm performance than firms who have had shorter experience in foreign markets. This study contributes to the growing knowledge base about retailers' international expansion in the apparel industry and fills a gap in the literature about the U.S. apparel retailers' international expansion. The findings can provide information related to the specific status of U.S. apparel firms' current internationalization process and serve as useful references to U.S. apparel companies that consider their growth opportunities to include internationalization. The findings and limitations of this study suggest some interesting directions for future research
Spatial resolution study and power calibration of the high-k scattering system on NSTX
NSTX high-k scattering system has been extensively utilized in studying the microturbulence and coherent waves. An absolute calibration of the scattering system was performed employing a new millimeter-wave source and calibrated attenuators. One of the key parameters essential for the calibration of the multichannel scattering system is the interaction length. This interaction length is significantly different from the conventional one due to the curvature and magnetic shear effect.ope
SYZ mirror symmetry for hypertoric varieties
We construct a Lagrangian torus fibration on a smooth hypertoric variety and
a corresponding SYZ mirror variety using -duality and generating functions
of open Gromov-Witten invariants. The variety is singular in general. We
construct a resolution using the wall and chamber structure of the SYZ base.Comment: v_2: 31 pages, 5 figures, minor revision. To appear in Communications
in Mathematical Physic
Effects of hydroxyapatite and PDGF concentrations on osteoblast growth in a nanohydroxyapatite-polylactic acid composite for guided tissue regeneration
The technique of guided tissue regeneration (GTR) has evolved over recent years in an attempt to achieve periodontal tissue regeneration by the use of a barrier membrane. However, there are significant limitations in the currently available membranes and overall outcomes may be limited. A degradable composite material was investigated as a potential GTR membrane material. Polylactic acid (PLA) and nanohydroxyapatite (nHA) composite was analysed, its bioactive potential and suitability as a carrier system for growth factors were assessed. The effect of nHA concentrations and the addition of platelet derived growth factor (PDGF) on osteoblast proliferation and differentiation was investigated. The bioactivity was dependent on the nHA concentration in the films, with more apatite deposited on films containing higher nHA content. Osteoblasts proliferated well on samples containing low nHA content and differentiated on films with higher nHA content. The composite films were able to deliver PDGF and cell proliferation increased on samples that were pre absorbed with the growth factor. nHA–PLA composite films are able to deliver active PDGF. In addition the bioactivity and cell differentiation was higher on films containing more nHA. The use of a nHA–PLA composite material containing a high concentration of nHA may be a useful material for GTR membrane as it will not only act as a barrier, but may also be able to enhance bone regeneration by delivery of biologically active molecules
Genetic diversity of Brazilian isolates of feline immunodeficiency virus
We isolated Feline immunodeficiency virus (FIV) from three adult domestic cats, originating from two open shelters in Brazil. Viruses were isolated from PBMC following co-cultivation with the feline T-lymphoblastoid cell line MYA-1. All amplified env gene products were cloned directly into pGL8MYA. The nucleic acid sequences of seven clones were determined and then compared with those of previously described isolates. The sequences of all of the Brazilian virus clones were distinct and phylogenetic analysis revealed that all belong to subtype B. Three variants isolated from one cat and two variants were isolated from each of the two other cats, indicating that intrahost diversity has the potential to pose problems for the treatment and diagnosis of FIV infection
Apoplastic fluid preparation from Arabidopsis thaliana leaves upon interaction with a non-adapted powdery mildew pathogen
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