4,385 research outputs found

    Contrasting the effectiveness and efficiency of virtual reality and real environments in the treatment of acrophobia

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    Previous studies reported good results in using virtual reality for the treatment of acrophobia. Similarly this paper reports the use of a virtual environment for the treatment of acrophobia. In the study, 10 subjects were exposed to three sessions of simulated heights in a virtual reality (VR) system, and 5 others were exposed to a real environment. Both groups revealed significant progress in a range of anxiety, avoidance and behaviour measurements when confronted with virtual as well as real height circumstances. Despite VR participants experiencing considerably shorter treatment times than the real-world subjects, significant improvements were recorded on the Behavioural Avoidance Test, the Attitudes Toward Heights Questionnaire and the Acrophobia Questionnaire. These results are suggestive of a possible higher effectiveness and efficiency of VR in treating acrophobia

    Impact of ocean warming on a coral reef fish learning and memory

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    Tropical ectotherms are highly sensitive to environmental warming, especially coral reef fishes, which are negatively impacted by an increase of a few degrees in ocean temperature. However, much of our understanding on the thermal sensitivity of reef fish is focused on a few traits (e.g., metabolism, reproduction) and we currently lack knowledge on warming effects on cognition, which may endanger decision-making and survival. Here, we investigated the effects of warming on learning and memory in a damselfish species, Acanthochromis polyacanthus. Fish were held at 28ā€“28.5ā—¦C (control group), 30ā€“30.5ā—¦C (moderate warming group) or 31.5ā€“32ā—¦C (high warming group) for 2 weeks, and then trained to associate a blue tag (cue) to the presence of a conspecific (reward). Following 20 training trials (5 days), fish were tested for associative learning (on the following day) and memory storage (after a 5-days interval). The control group A. polyacanthus showed learning of the task and memory retention after five days, but increasing water temperature impaired learning and memory. A thorough understanding of the effects of heat stress, cognition, and fitness is urgently required because cognition may be a key factor determining animalsā€™ performance in the predicted scenario of climate changes. Knowing how different species respond to warming can lead to better predictions of future community dynamics, and because it is species specific, it could pinpoint vulnerable/resilience species

    CD4 T cell help prevents CD8 T cell exhaustion and promotes control of Mycobacterium tuberculosis infection [preprint]

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    CD4 T cells are essential for immunity to tuberculosis because they produce cytokines including interferon-Ī³. Whether CD4 T cells act as ā€œhelperā€ cells to promote optimal CD8 T cell responses during Mycobacterium tuberculosis is unknown. Using two independent models, we show that CD4 T cell help enhances CD8 effector functions and prevents CD8 T cell exhaustion. We demonstrate synergy between CD4 and CD8 T cells in promoting the survival of infected mice. Purified helped, but not helpless, CD8 T cells efficiently restrict intracellular bacterial growth in vitro. Thus, CD4 T cell help plays an essential role in generating protective CD8 T cell responses against M. tuberculosis infection in vitro and in vivo. We infer vaccines that elicit both CD4 and CD8 T cells are more likely to be successful than vaccines that elicit only CD4 or CD8 T cells

    Protein farnesyltransferase and protein prenylation in Plasmodium falciparum

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    Comparison of the malaria parasite and mammalian protein prenyltransferases and their cellular substrates is important for establishing this enzyme as a target for developing antimalarial agents. Nineteen heptapeptides differing only in their carboxyl-terminal amino acid were tested as alternative substrates of partially purified Plasmodium falciparum protein farnesyltransferase. Only NRSCAIM and NRSCAIQ serve as substrates, with NRSCAIM being the best. Peptidomimetics, FTI-276 and GGTI-287, inhibit the transferase with IC50 values of 1 and 32 nm, respectively. Incubation of P. falciparum-infected erythrocytes with [H-3]farnesol labels 50- and 22-28-kDa proteins, whereas [H-3]geranylgeraniol labels only 22-28-kDa proteins. The 50-kDa protein is shown to be farnesylated, whereas the 22-28-kDa proteins are geranylgeranylated, irrespective of the labeling prenol. Protein labeling is inhibited more than 50% by either 5 mum FTI-277 or GGTI-298. The same concentration of inhibitors also inhibits parasite growth from the ring stage by 50%, decreases expression of prenylated proteins as measured with prenyl-specific antibody, and inhibits parasite differentiation beyond the trophozoite stage. Furthermore, differentiation specific prenylation of P. falciparum proteins is demonstrated. Protein labeling is detected predominantly during the trophozoite to schizont and schizont to ring transitions. These results demonstrate unique properties of protein prenylation in P. falciparum: a limited specificity of the farnesyltransferase for peptide substrates compared with mammalian enzymes, the ability to use farnesol to label both farnesyl and geranylgeranyl moieties on proteins, differentiation specific protein prenylation, and the ability of peptidomimetic prenyltransferase inhibitors to block parasite differentiation

    Implantable loop recorder monitoring for refining management of children with inherited arrhythmia syndromes

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    BACKGROUND: Implantable loop recorders (ILRs) are conventionally utilized to elucidate the mechanism of atypical syncope. The objective of this study was to assess the impact of these devices on management of pediatric patients with known or suspected inherited arrhythmia syndromes. METHODS AND RESULTS: A retrospective chart review was undertaken of all pediatric patients with known or suspected inherited arrhythmia syndromes in whom an ILR was implanted from 2008 to 2015. Captured data included categorization of diagnosis, treatment, transmitted tracings, and the impact of ILR tracings on management. Transmissions were categorized as symptomatic, autotriggered, or routine. Actionable transmissions were abnormal tracings that directly resulted in a change of medical or device therapy. A total of 20 patients met the stated inclusion criteria (long QT syndrome, n=8, catecholaminergic polymorphic ventricular tachycardia,n=9, Brugada syndrome, n=1, arrhythmogenic right ventricular cardiomyopathy, n=2), with 60% of patients being genotype positive. Primary indication for implantation of ILR included ongoing monitoring +/āˆ’ symptoms (n=15, 75%), suspicion of noncompliance (n=1, 5%), and liberalization of recommended activity restrictions (n=4, 25%). A total of 172 transmissions were received in patients with inherited arrhythmia syndromes, with 7% yielding actionable data. The majority (52%) of symptom events were documented in the long QT syndrome population, with only 1 tracing (5%) yielding actionable data. Automatic transmissions were mostly seen in the catecholaminergic polymorphic ventricular tachycardia cohort (81%), with 21% yielding actionable data. There was no actionable data in routine transmissions. CONCLUSIONS: ILRs in patients with suspected or confirmed inherited arrhythmia syndromes may be useful for guiding management. Findings escalated therapies in 30% of subjects. As importantly, in this highā€risk population, the majority of symptom events represented normal or benign rhythms, reassuring patients and physicians that no further intervention was required

    NADES-based cork extractives as green ingredients for cosmetics and textiles

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    The demand for products based on natural ingredients is increasing among cosmetic and textile consumers. Cork extracts contain components of interest with special properties, including antioxidant, anti-inflammatory, and antibacterial activities, that might improve the effectiveness of cosmetic formulations currently on the market and may impart new characteristics to textiles. The main goal of this work was to investigate the effect of the incorporation of three cork extracts into two commercial cosmetic formulations (formulation A and B) and evaluate their role as textile dyeing agents. The extracts (E1, E2, and E3) were obtained from cork powder using natural deep eutectic solvents (NADES) (E1-NADES 1: lactic acid:glycerol, E2-NADES 2: lactic acid:glycine, and E3-NADES 3: lactic acid:sodium citrate) and applied in combination with the solvent. The impact of the extracts on the cosmetic formulationsā€™ properties was evaluated in terms of pH, viscosity, antioxidant activity, transdermal permeation capacity, cytotoxicity, and organoleptic characteristics (odor, color, and appearance). The results demonstrated that the cork extracts improved the antioxidant performance of the formulations (90% reduction in DPPH (1,1-difenil-2-picril-hidrazil)). Moreover, low concentrations (5 mg/mL and 10 mg/mL) of extract did not present a cytotoxic effect on keratinocytes. Cotton fabrics were efficiently dyed with the NADES-based cork extracts which conferred to these substrates antioxidant (78% in DPPH reduction) and antibacterial abilities (inhibition halos: 12ā€“15 mm). The application of cork extracts as ingredients in cosmetics or as dyeing/coloration agents for textile coloration is revealed to be a promising and green route to replace harmful ingredients normally used in industry.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit. D.S.F. also thanks the Portuguese Foundation for Science and Technology (FCT) for funding (SFRH/BD/147190/2019). A.R. thanks to Portuguese Foundation for Science and Technology (FCT) for is contract under the CEEC-Individualā€”4th Edition with the reference 2021.02803.CEECIND.info:eu-repo/semantics/publishedVersio

    Factors associated with the performance and cost-effectiveness of using lymphatic filariasis transmission assessment surveys for monitoring soil-transmitted helminths: a case study in Kenya.

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    Transmission assessment surveys (TAS) for lymphatic filariasis have been proposed as a platform to assess the impact of mass drug administration (MDA) on soil-transmitted helminths (STHs). This study used computer simulation and field data from pre- and post-MDA settings across Kenya to evaluate the performance and cost-effectiveness of the TAS design for STH assessment compared with alternative survey designs. Variations in the TAS design and different sample sizes and diagnostic methods were also evaluated. The district-level TAS design correctly classified more districts compared with standard STH designs in pre-MDA settings. Aggregating districts into larger evaluation units in a TAS design decreased performance, whereas age group sampled and sample size had minimal impact. The low diagnostic sensitivity of Kato-Katz and mini-FLOTAC methods was found to increase misclassification. We recommend using a district-level TAS among children 8-10 years of age to assess STH but suggest that key consideration is given to evaluation unit size
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