The efficiency of visual transparency

This thesis examines the phenomenon of visual transparency in a novel application of the efficiency approach. Transparency provides a useful stimulus to probe the visual mechanisms that underlie the visual surface representation, introduced in Chapter One. Previous research has found that there is a cost in processing visual transparency defined purely by motion or stereo cues. This has been interpreted in terms of visual mechanisms constraining the recovery of transparency. However, the cost for transparency may reflect the increased complexity of the stimuli. To address this issue I computed the efficiency for motion and stereo defined transparency tasks by comparing human performance with that of the ideal observer. The efficiency approach has two key advantages over traditional psychophysical measures: 1) it provides a performance measure normalised relative to the available information, 2) it is an absolute measure and can be compared directly across diverse tasks. I provide a review of the efficiency approach in Chapter Two. In Chapter Three, I present a study of the efficiency for speed discrimination of transparent random dot stimuli and comparable non-transparent random dot stimuli, as a function of the speed ratio and the dot density of the stimuli. In Chapter Four, I present a study of the efficiency for depth discrimination of transparent and non-transparent random dot stereograms, across a range of disparity ratios and dot densities. In Chapter Five, I present an extension of the efficiency approach to the motor domain, for the smooth pursuit of high-density transparent and non-transparent random-dot stimuli. Finally, in Chapter Six I provide physiologically plausible accounts of the findings

Cardiac fibrosis can be attenuated by blocking the activity of transglutaminase 2 using a selective small-molecule inhibitor

Cardiac fibrosis is implicit in all forms of heart disease but there are no effective treatments. In this report, we investigate the role of the multi-functional enzyme Transglutaminase 2 (TG2) in cardiac fibrosis and assess its potential as a therapeutic target. Here we describe the use a highly selective TG2 small-molecule inhibitor to test the efficacy of TG2 inhibition as an anti-fibrotic therapy for heart failure employing two different in vivo models of cardiac fibrosis: Progressively induced interstitial cardiac fibrosis by pressure overload using angiotensin II infusion: Acutely induced focal cardiac fibrosis through myocardial infarction by ligation of the left anterior descending coronary artery (AMI model). In the AMI model, in vivo MRI showed that the TG2 inhibitor 1–155 significantly reduced infarct size by over 50% and reduced post-infarct remodelling at 20 days post insult. In both models, Sirius red staining for collagen deposition and levels of the TG2-mediated protein crosslink ε(γ-glutamyl)lysine were significantly reduced. No cardiac rupture or obvious signs of toxicity were observed. To provide a molecular mechanism for TG2 involvement in cardiac fibrosis, we show that both TGFβ1-induced transition of cardiofibroblasts into myofibroblast-like cells and TGFβ1- induced EndMT, together with matrix deposition, can be attenuated by the TG2 selective inhibitor 1–155, suggesting a new role for TG2 in regulating TGFβ1 signalling in addition to its role in latent TGFβ1 activation. In conclusion, TG2 has a role in cardiac fibrosis through activation of myofibroblasts and matrix deposition. TG2 inhibition using a selective small-molecule inhibitor can attenuate cardiac fibrosis

Mental health of female foreign spouses in transnational marriages in southern Taiwan

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to investigate the mental health status, and the risk factors associated with mild psychiatric disorders, of female foreign spouses (from Vietnam, Indonesia, and mainland China) in southern Taiwan, and to understand the mental health needs of these women.</p> <p>Methods</p> <p>One hundred and twenty nine participants were willing to participate in this study. All participants fulfilled all questionnaires which included demographic information, the Chinese Health Questionnaire (CHQ), the Eysenck Personality Questionnaire (EPQ), and the Mental Health Care Needs Questionnaire (MHCNQ).</p> <p>Results</p> <p>By multiple linear regression, neuroticism characteristics (p = 0.000), the dimension of knowledge of the level of their own psychological disturbance (p = 0.001), dimension of friends assistance (p = 0.033), and dimension of religion comfort (p = 0.041) in mental health care needs could be used to predict possible mild psychiatric disorders. Furthermore, SEM model showed that Indonesian or Vietnamese spouses have more likely degree in mental health care needs (β = -0.24, <it>p </it>= 0.003), compared with Chinese ones. A higher level of neuroticism was associated with a greater likelihood of mild psychiatric disorder (β = 0.54, <it>p </it>< 0.001), and of mental health care needs (β = 0.21, <it>p </it>= 0.013). A higher degree of mental health care needs was related to a greater likelihood of mild psychiatric disorder (β = 0.14, <it>p </it>= 0.05).</p> <p>Conclusion</p> <p>In conclusion, we have obtained a better understanding of the mental health status of female foreign spouses in transnational marriages, who face many difficulties. Indonesian or Vietnamese spouses tend to more likely degree in mental health care needs than Chinese spouses, and then indirectly influenced their mental health status. Some individuals with a neurotic personality are exposed to high risk and might suffer from mild psychiatric symptoms. The needs for psychological counseling and religion therapy were the first priority for these women, particularly the Indonesian and Vietnamese spouses. From these findings, we have a better understanding of how to assist these female foreign spouses in future.</p

Influence of taste disorders on dietary behaviors in cancer patients under chemotherapy

<p>Abstract</p> <p>Objectives</p> <p>To determine the relationship between energy and nutrient consumption with chemosensory changes in cancer patients under chemotherapy.</p> <p>Methods</p> <p>We carried out a cross-sectional study, enrolling 60 subjects. Cases were defined as patients with cancer diagnosis after their second chemotherapy cycle (n = 30), and controls were subjects without cancer (n = 30). Subjective changes of taste during treatment were assessed. Food consumption habits were obtained with a food frequency questionnaire validated for Mexican population. Five different concentrations of three basic flavors --sweet (sucrose), bitter (urea), and a novel basic taste, umami (sodium glutamate)-- were used to measure detection thresholds and recognition thresholds (RT). We determine differences between energy and nutrient consumption in cases and controls and their association with taste DT and RT.</p> <p>Results</p> <p>No demographic differences were found between groups. Cases showed higher sweet DT (6.4 vs. 4.4 μmol/ml; p = 0.03) and a higher bitter RT (100 vs. 95 μmol/ml; <it>p </it>= 0.04) than controls. Cases with sweet DT above the median showed significant lower daily energy (2,043 vs.1,586 kcal; p = 0.02), proteins (81.4 vs. 54 g/day; <it>p </it>= 0.01), carbohydrates (246 vs.192 g/day; <it>p </it>= 0.05), and zinc consumption (19 vs.11 mg/day; <it>p </it>= 0.01) compared to cases without sweet DT alteration. Cases with sweet DT and RT above median were associated with lower completion of energy requirements and consequent weight loss. There was no association between flavors DT or RT and nutrient ingestion in the control group.</p> <p>Conclusion</p> <p>Changes of sweet DT and bitter RT in cancer patients under chemotherapy treatment were associated with lower energy and nutrient ingestion. Taste detection and recognition thresholds disorders could be important factors in malnutrition development on patients with cancer under chemotherapy treatment.</p

Molecular epidemiology and evolutionary genetics of Mycobacterium tuberculosis in Taipei

<p>Abstract</p> <p>Background</p> <p>The control of tuberculosis in densely populated cities is complicated by close human-to-human contacts and potential transmission of pathogens from multiple sources. We conducted a molecular epidemiologic analysis of 356 <it>Mycobacterium tuberculosis </it>(MTB) isolates from patients presenting pulmonary tuberculosis in metropolitan Taipei. Classical antibiogram studies and genetic characterization, using mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) typing and spoligotyping, were applied after culture.</p> <p>Methods</p> <p>A total of 356 isolates were genotyped by standard spoligotyping and the strains were compared with in the international spoligotyping database (SpolDB4). All isolates were also categorized using the 15 loci MIRU-VNTR typing method and combin with <it>NTF </it>locus and RD deletion analyses.</p> <p>Results</p> <p>Of 356 isolates spoligotyped, 290 (81.4%) displayed known spoligotypes and 66 were not identified in the database. Major spoligotypes found were Beijing lineages (52.5%), followed by Haarlem lineages (13.5%) and EAI plus EAI-like lineages (11%). When MIRU-VNTR was employed, 140 patterns were identified, including 36 clusters by 252 isolates and 104 unique patterns, and the largest cluster comprised 95 isolates from the Beijing family. The combination of spoligotyping and MIRU-VNTR revealed that 236 (67%) of the 356 isolates were clustered in 43 genotypes. Strains of the Beijing family was more likely to be of modern strain and a higher percentage of multiple drug resistance than other families combined (P = 0.08). Patients infected with Beijing strains were younger than those with other strains (mean 58.7 vs. 64.2, p = 0.02). Moreover, 85.3% of infected persons younger than 25 years had Beijing modern strain, suggesting a possible recent spread in the young population by this family of TB strain in Taipei.</p> <p>Conclusion</p> <p>Our data on MTB genotype in Taipei suggest that MTB infection has not been optimally controlled. Control efforts should be reinforced in view of the high prevalence of the Beijing strain in young population and association with drug resistance.</p

New materials and devices for preventing catheter-related infections

Catheters are the leading source of bloodstream infections for patients in the intensive care unit (ICU). Comprehensive unit-based programs have proven to be effective in decreasing catheter-related bloodstream infections (CR-BSIs). ICU rates of CR-BSI higher than 2 per 1,000 catheter-days are no longer acceptable. The locally adapted list of preventive measures should include skin antisepsis with an alcoholic preparation, maximal barrier precautions, a strict catheter maintenance policy, and removal of unnecessary catheters. The development of new technologies capable of further decreasing the now low CR-BSI rate is a major challenge. Recently, new materials that decrease the risk of skin-to-vein bacterial migration, such as new antiseptic dressings, were extensively tested. Antimicrobial-coated catheters can prevent CR-BSI but have a theoretical risk of selecting resistant bacteria. An antimicrobial or antiseptic lock may prevent bacterial migration from the hub to the bloodstream. This review discusses the available knowledge about these new technologies