1,564 research outputs found

    Humans Sensitivity Distribution in Perceptual Space by a Wearable Haptic Sleeve

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    It is very important to understand humans’ perception when the other communication modalities like vision and audition are partially or fully impaired. Therefore, this paper tries to give a brief overview on humans’ sensitivity distribution in perceptual space. During our experiments, a wearable haptic sleeve consisted of 7 vibro-actuators was used to stimulate subjects arm to convey haptic feedback. The basic research questions in this study are: 1) whether humans’ perception linearly correlated with the actuation frequency, haptic feedback in our scenario 2) humans’ ability to generalise templates via the wearable haptic sleeve. Those findings would be useful to increase humans’ perception when humans have to work with fully or partially impaired perception in their day-to-day life

    Mindfulness-based interventions for people diagnosed with a current episode of an anxiety or depressive disorder: a meta-analysis of randomised controlled trials

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    Objective Mindfulness-based interventions (MBIs) can reduce risk of depressive relapse for people with a history of recurrent depression who are currently well. However, the cognitive, affective and motivational features of depression and anxiety might render MBIs ineffective for people experiencing current symptoms. This paper presents a meta-analysis of randomised controlled trials (RCTs) of MBIs where participants met diagnostic criteria for a current episode of an anxiety or depressive disorder. Method Post-intervention between-group Hedges g effect sizes were calculated using a random effects model. Moderator analyses of primary diagnosis, intervention type and control condition were conducted and publication bias was assessed. Results Twelve studies met inclusion criteria (n = 578). There were significant post-intervention between-group benefits of MBIs relative to control conditions on primary symptom severity (Hedges g = −0.59, 95% CI = −0.12 to −1.06). Effects were demonstrated for depressive symptom severity (Hedges g = −0.73, 95% CI = −0.09 to −1.36), but not for anxiety symptom severity (Hedges g = −0.55, 95% CI = 0.09 to −1.18), for RCTs with an inactive control (Hedges g = −1.03, 95% CI = −0.40 to −1.66), but not where there was an active control (Hedges g = 0.03, 95% CI = 0.54 to −0.48) and effects were found for MBCT (Hedges g = −0.39, 95% CI = −0.15 to −0.63) but not for MBSR (Hedges g = −0.75, 95% CI = 0.31 to −1.81). Conclusions This is the first meta-analysis of RCTs of MBIs where all studies included only participants who were diagnosed with a current episode of a depressive or anxiety disorder. Effects of MBIs on primary symptom severity were found for people with a current depressive disorder and it is recommended that MBIs might be considered as an intervention for this population

    Risk factors for high anti-HHV-8 antibody titers (≥1:51,200) in black, HIV-1 negative South African cancer patients: a case control study

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    Background: Infection with human herpesvirus 8 (HHV-8) is the necessary causal agent in the development of Kaposi's sarcoma (KS). Infection with HIV-1, male gender and older age all increase risk for KS. However, the geographic distribution of HHV-8 and KS both prior to the HIV/AIDS epidemic and with HIV/AIDS suggest the presence of an additional co-factor in the development of KS. Methods: Between January 1994 and October 1997, we interviewed 2576 black in-patients with cancer in Johannesburg and Soweto, South Africa. Blood was tested for antibodies against HIV-1 and HHV-8 and the study was restricted to 2191 HIV-1 negative patients. Antibodies against the latent nuclear antigen of HHV-8 encoded by orf73 were detected with an indirect immunofluorescence assay. We examined the relationship between high anti-HHV-8 antibody titers (≥1:51,200) and sociodemographic and behavioral factors using unconditional logistic regression models. Variables that were significant at p = 0.10 were included in multivariate analysis. Results: Of the 2191 HIV-1 negative patients who did not have Kaposi's sarcoma, 854 (39.0%) were positive for antibodies against HHV-8 according to the immunofluorescent assay. Among those seropositive for HHV-8, 530 (62.1%) had low titers (1:200), 227 (26.6%) had medium titers (1:51,200) and 97 (11.4%) had highest titers (1:204,800). Among the 2191 HIV-1 negative patients, the prevalence of high anti-HHV-8 antibody titers (≥1:51,200) was independently associated with increasing age (ptrend = 0.04), having a marital status of separated or divorced (p = 0.003), using wood, coal or charcoal as fuel for cooking 20 years ago instead of electricity (p = 0.02) and consuming traditional maize beer more than one time a week (p = 0.02; p-trend for increasing consumption = 0.05) although this may be due to chance given the large number of predictors considered in this analysis. Conclusions: Among HIV-negative subjects, patients with high anti-HHV-8 antibody titers are characterized by older age. Other associations that may be factors in the development of high anti- HHV-8 titers include exposure to poverty or a low socioeconomic status environment and consumption of traditional maize beer. The relationship between these variables and high anti- HHV-8 titers requires further, prospective study

    ZipA Binds to FtsZ with High Affinity and Enhances the Stability of FtsZ Protofilaments

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    A bacterial membrane protein ZipA that tethers FtsZ to the membrane is known to promote FtsZ assembly. In this study, the binding of ZipA to FtsZ was monitored using fluorescence spectroscopy. ZipA was found to bind to FtsZ with high affinities at three different (6.0, 6.8 and 8.0) pHs, albeit the binding affinity decreased with increasing pH. Further, thick bundles of FtsZ protofilaments were observed in the presence of ZipA under the pH conditions used in this study indicating that ZipA can promote FtsZ assembly and stabilize FtsZ polymers under unfavorable conditions. Bis-ANS, a hydrophobic probe, decreased the interaction of FtsZ and ZipA indicating that the interaction between FtsZ and ZipA is hydrophobic in nature. ZipA prevented the dilution induced disassembly of FtsZ polymers suggesting that it stabilizes FtsZ protofilaments. Fluorescein isothiocyanate-labeled ZipA was found to be uniformly distributed along the length of the FtsZ protofilaments indicating that ZipA stabilizes FtsZ protofilaments by cross-linking them

    Resolving the Trophic Relations of Cryptic Species: An Example Using Stable Isotope Analysis of Dolphin Teeth

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    Understanding the foraging ecology and diet of animals can play a crucial role in conservation of a species. This is particularly true where species are cryptic and coexist in environments where observing feeding behaviour directly is difficult. Here we present the first information on the foraging ecology of a recently identified species of dolphin (Southern Australian bottlenose dolphin (SABD)) and comparisons to the common bottlenose dolphin (CBD) in Victoria, Australia, using stable isotope analysis of teeth. Stable isotope signatures differed significantly between SABD and CBD for both δ13C (−14.4‰ vs. −15.5‰ respectively) and δ15N (15.9‰ vs. 15.0‰ respectively), suggesting that the two species forage in different areas and consume different prey. This finding supports genetic and morphological data indicating that SABD are distinct from CBD. In Victoria, the SABD is divided into two distinct populations, one in the large drowned river system of Port Phillip Bay and the other in a series of coastal lakes and lagoons called the Gippsland Lakes. Within the SABD species, population differences were apparent. The Port Phillip Bay population displayed a significantly higher δ15N than the Gippsland Lakes population (17.0‰ vs. 15.5‰), suggesting that the Port Phillip Bay population may feed at a higher trophic level - a result which is supported by analysis of local food chains. Important future work is required to further understand the foraging ecology and diet of this newly described, endemic, and potentially endangered species of dolphin

    Vascular endothelial growth factor as a non-invasive marker of pulmonary vascular remodeling in patients with bronchitis-type of COPD

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    BACKGROUND: Several studies have indicated that one of the most potent mediators involved in pulmonary vascular remodeling is vascular endothelial growth factor (VEGF). This study was designed to determine whether airway VEGF level reflects pulmonary vascular remodeling in patients with bronchitis-type of COPD. METHODS: VEGF levels in induced sputum were examined in 23 control subjects (12 non-smokers and 11 ex-smokers) and 29 patients with bronchitis-type of COPD. All bronchitis-type patients performed exercise testing with right heart catheterization. RESULTS: The mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) after exercise were markedly increased in all bronchitis-type patients. However, both parameters after exercise with breathing of oxygen was significantly lower than in those with breathing of room air. To attenuate the effect of hypoxia-induced pulmonary vasoconstriction during exercise, we used the change in mPAP or PVR during exercise with breathing of oxygen as a parameter of pulmonary vascular remodeling. Change in mPAP was significantly correlated with VEGF level in induced sputum from patients with chronic bronchitis (r = 0.73, p = 0.0001). Moreover, change in PVR was also correlated with VEGF level in those patients (r = 0.57, p = 0.003). CONCLUSION: A close correlation between magnitude of pulmonary hypertension with exercise and VEGF level in bronchitis-type patients could be observed. Therefore, these findings suggest the possibility that VEGF level in induced sputum is a non-invasive marker of pulmonary vascular remodeling in patients with bronchitis-type of COPD

    Applying neutral drift to the directed molecular evolution of a β-glucuronidase into a β-galactosidase: Two different evolutionary pathways lead to the same variant

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    <p>Abstract</p> <p>Background</p> <p>Directed protein evolution has been used to modify protein activity and research has been carried out to enhance the production of high quality mutant libraries. Many theoretical approaches suggest that allowing a population to undergo neutral selection may be valuable in directed evolution experiments.</p> <p>Findings</p> <p>Here we report on an investigation into the value of neutral selection in a classical model system for directed evolution, the conversion of the <it>E. coli </it>β-glucuronidase to a β-galactosidase activity. We find that neutral selection, i.e. selection for retaining glucuronidase activity, can efficiently identify the majority of sites of mutation that have been identified as beneficial for galactosidase activity in previous experiments. Each variant demonstrating increased galactosidase activity identified by our neutral drift experiments contained a mutation at one of four sites, T509, S557, N566 or W529. All of these sites have previously been identified using direct selection for beta galactosidase activity.</p> <p>Conclusions</p> <p>Our results are consistent with others that show that a neutral selection approach can be effective in selecting improved variants. However, we interpret our results to show that neutral selection is, in this case, not a more efficient approach than conventional directed evolution approaches. However, the neutral approach is likely to be beneficial when the resulting library can be screened for a range of related activities. More detailed statistical studies to resolve the apparent differences between this system and others are likely to be a fruitful avenue for future research.</p

    Longitudinal Associations Between Perceived Parent-Child Relationship Quality and Depressive Symptoms in Adolescence

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    This longitudinal study examined bidirectional paths between perceived parent-adolescent relationship quality and depressive symptoms, as well as the moderating role of sex, age, and personality type. 1313 Dutch adolescents (51% girls) from two cohorts (923 12-year olds and 390 16-year olds at Wave 1) reported on their personality, depressive symptoms, and perceived relationship quality to parents in four waves. Consistent with a relationship erosion perspective, depressive symptoms negatively predicted perceived relationship quality with parents. Relationship quality to mothers predicted depressive symptoms for boys and girls, but relationship quality to fathers predicted depressive symptoms only for boys. Personality type only moderated initial associations between relationship quality with mothers and depressive symptoms, which were stronger for Overcontrollers and Undercontrollers than for Resilients. Results thus reveal a pattern of mutual influence between perceived relationship quality and depressive symptoms that is moderated by the interplay among parent and adolescent sex and adolescent personality type

    Individual Recognition in Domestic Cattle (Bos taurus): Evidence from 2D-Images of Heads from Different Breeds

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    BACKGROUND: In order to maintain cohesion of groups, social animals need to process social information efficiently. Visual individual recognition, which is distinguished from mere visual discrimination, has been studied in only few mammalian species. In addition, most previous studies used either a small number of subjects or a few various views as test stimuli. Dairy cattle, as a domestic species allow the testing of a good sample size and provide a large variety of test stimuli due to the morphological diversity of breeds. Hence cattle are a suitable model for studying individual visual recognition. This study demonstrates that cattle display visual individual recognition and shows the effect of both familiarity and coat diversity in discrimination. [br/]METHODOLOGY/PRINCIPAL FINDINGS: We tested whether 8 Prim'Holstein heifers could recognize 2D-images of heads of one cow (face, profiles, (3/4) views) from those of other cows. Experiments were based on a simultaneous discrimination paradigm through instrumental conditioning using food rewards. In Experiment 1, all images represented familiar cows (belonging to the same social group) from the Prim'Holstein breed. In Experiments 2, 3 and 4, images were from unfamiliar (unknown) individuals either from the same breed or other breeds. All heifers displayed individual recognition of familiar and unfamiliar individuals from their own breed. Subjects reached criterion sooner when recognizing a familiar individual than when recognizing an unfamiliar one (Exp 1: 3.1+/-0.7 vs. Exp 2: 5.2+/-1.2 sessions; Z = 1.99, N = 8, P = 0.046). In addition almost all subjects recognized unknown individuals from different breeds, however with greater difficulty. [br/] CONCLUSIONS/SIGNIFICANCE: Our results demonstrated that cattle have efficient individual recognition based on categorization capacities. Social familiarity improved their performance. The recognition of individuals with very different coat characteristics from the subjects was the most difficult task. These results call for studies exploring the mechanisms involved in face recognition allowing interspecies comparisons, including humans
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