645 research outputs found

    Processing time not modality dominates shift costs in the modality-shifting effect

    Get PDF
    Shifting attention between visual and auditory targets is associated with reaction time costs, known as the modality-shifting effect. The type of modality shifted from, e.g., auditory or visual is suggested to have an effect on the degree of cost. Studies report greater costs shifting from visual stimuli, yet notably used visual stimuli that are also identified slower than the auditory. It is not clear whether the cost is specific to modality effects, or with identification speed independent of modality. Here, to interpret whether the effects are due to modality or identification time, switch costs are instead compared with auditory stimuli that are identified slower than the visual (inverse of tested previously). A second condition used the same auditory stimuli at a low intensity, allowing comparison of semantically identical stimuli that are even slower to process. The current findings contradicted suggestions of a general difficulty in shifting from visual stimuli (as previously reported), and instead suggest that cost is reduced when targets are preceded by a more rapidly processed stimulus. ‘Modality-Shifting’ as it is often termed induces shifting costs, but the costs are not because of a change of modality per se, but because of a change in identification speed, where the degree of cost is dependent on the processing time of the surrounding stimuli

    Space construction system analysis. Part 2: Construction analysis

    Get PDF
    The construction methods specific to the end to end construction process for building the ETVP in low Earth orbit, using the space shuttle orbiter as a construction base, are analyzed. The analyses concerned three missions required to build the basic platform. The first mission involved performing the fabrication of beams in space and assembling the beams into a basic structural framework. The second mission was to install the forward support structure and aft support structure, the forward assembly, and a TT&C antenna. The third mission plan was to complete the construction of the platform and activate it to begin operations in low Earth orbit. The integration of the activities for each mission is described along with the construction requirements and construction logic

    Social interactions through the eyes of macaques and humans

    Get PDF
    Group-living primates frequently interact with each other to maintain social bonds as well as to compete for valuable resources. Observing such social interactions between group members provides individuals with essential information (e.g. on the fighting ability or altruistic attitude of group companions) to guide their social tactics and choice of social partners. This process requires individuals to selectively attend to the most informative content within a social scene. It is unclear how non-human primates allocate attention to social interactions in different contexts, and whether they share similar patterns of social attention to humans. Here we compared the gaze behaviour of rhesus macaques and humans when free-viewing the same set of naturalistic images. The images contained positive or negative social interactions between two conspecifics of different phylogenetic distance from the observer; i.e. affiliation or aggression exchanged by two humans, rhesus macaques, Barbary macaques, baboons or lions. Monkeys directed a variable amount of gaze at the two conspecific individuals in the images according to their roles in the interaction (i.e. giver or receiver of affiliation/aggression). Their gaze distribution to non-conspecific individuals was systematically varied according to the viewed species and the nature of interactions, suggesting a contribution of both prior experience and innate bias in guiding social attention. Furthermore, the monkeys’ gaze behavior was qualitatively similar to that of humans, especially when viewing negative interactions. Detailed analysis revealed that both species directed more gaze at the face than the body region when inspecting individuals, and attended more to the body region in negative than in positive social interactions. Our study suggests that monkeys and humans share a similar pattern of role-sensitive, species- and context-dependent social attention, implying a homologous cognitive mechanism of social attention between rhesus macaques and humans

    Role of lateral and feedback connections in primary visual cortex in the processing of spatiotemporal regularity: a TMS study

    Get PDF
    Our human visual system exploits spatiotemporal regularity to interpret incoming visual signals. With a dynamic stimulus sequence of four collinear bars (predictors) appearing consecutively toward the fovea, followed by a target bar with varying contrasts, we have previously found that this predictable spatiotemporal stimulus structure enhances target detection performance and its underlying neural process starts in the primary visual cortex (area V1). However, the relative contribution of V1 lateral and feedback connections in the processing of spatiotemporal regularity remains unclear. In this study we measured human contrast detection of a briefly presented foveal target that was embedded in a dynamic collinear predictor-target sequence. Transcranial magnetic stimulation (TMS) was used to selectively disrupt V1 horizontal and feedback connections in the processing of predictors. The coil was positioned over a cortical location corresponding to the location of the last predictor prior to target onset. Single-pulse TMS at an intensity of 10% below phosphene threshold was delivered at 20 or 90ms after the predictor onset. Our analysis revealed that the delivery of TMS at both time windows equally reduced, but did not abolish, the facilitation effect of the predictors on target detection. Furthermore, if the predictors’ ordination was randomized to suppress V1 lateral connections, the TMS disruption was significantly more evident at 20ms than at 90ms time window. We suggest that both lateral and feedback connections contribute to the encoding of spatiotemporal regularity in V1. These findings develop understanding of how our visual system exploits spatiotemporal regularity to facilitate the efficiency of visual perception

    Diagnostic yield and safety of ultrasound-guided bowel mass biopsies in children

    Get PDF
    Background Traditionally, ultrasound (US)-guided bowel mass biopsies are avoided in favour of endoscopic or surgical biopsies. However, endoscopy cannot easily reach lesions between the duodenojejunal flexure and the terminal ileum and lesions not involving the mucosa may not be accessible via an endoscopic route. Objective The aim of this study was to report our technique and to assess the diagnostic accuracy and safety of US-guided biopsy of bowel masses in children. Materials and methods We conducted a 14-year retrospective review of US-guided bowel mass biopsies at a single paediatric hospital. Results Twenty US-guided bowel mass biopsies were performed in 19 patients (median age: 6 years and 6 months, range: 22 months– 17 years, median weight: 22 kg, range: 10.2–48.4 kg). For 14 biopsies, there was no other lesion that could potentially be biopsied. A percutaneous coaxial technique was used for 19 biopsies and a transanal non-coaxial biopsy was performed in 1. A median of 9 (range: 2–15) cores of tissue was obtained at each biopsy. The technical success rate and adequacy of diagnostic yield were 100%. The most common diagnosis was lymphoma, which occurred in 16 biopsies. Three biopsies contained mucosa. There was one complication out of 20 biopsies (5%, 95% confidence interval 0–15%): a self-limiting, post biopsy pyrexia. Nineteen procedures were accompanied by a bone marrow aspirate and/or trephine within 2 weeks of the bowel biopsy, only one of which was diagnostic. Conclusion US-guided bowel mass biopsy can be performed safely in children, with a high diagnostic yield and low complication rat

    Living Dangerously: Culture of Honor, Risk-Taking, and the Nonrandomness of “Accidental” Deaths

    Get PDF
    Collin D. Barnes is a postdoctoral research fellow with the Institute for U.S.-China Issues at the University of Oklahoma.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Surgical jejunostomy and radiological gastro-jejunostomy feeding in children: Risks, benefits and nutritional outcomes

    Get PDF
    PURPOSE: Radiologically inserted gastrojejunal tubes (RGJ) and surgical jejunostomy (SJ) are established modes of jejunal feeding. The aim of the study is to review nutritional outcomes, complications and the practical consideration to enable patients and carers to make informed choice. METHODS: Retrospective review of patient notes with a RGJ or SJ in 2010, with detailed follow-up and review of the literature. RESULTS: Both RGJ and SJ are reliable modes to provide stable enteral nutrition. Both have complications and their own associated limitations. CONCLUSION: The choice has to be tailored to the individual patient, the social care available, the inherent medical disease and risk/benefit of repeated anaesthetic and radiation exposure. RGJ and SJ are important tools for nutritional management that achieve and maintain growth in a complex group of children. The risk and benefits should be reviewed for each individual patient

    Managing lifestyle change to reduce coronary risk: a synthesis of qualitative research on peoples’ experiences

    Get PDF
    Background Coronary heart disease is an incurable condition. The only approach known to slow its progression is healthy lifestyle change and concordance with cardio-protective medicines. Few people fully succeed in these daily activities so potential health improvements are not fully realised. Little is known about peoples’ experiences of managing lifestyle change. The aim of this study was to synthesise qualitative research to explain how participants make lifestyle change after a cardiac event and explore this within the wider illness experience. Methods A qualitative synthesis was conducted drawing upon the principles of meta-ethnography. Qualitative studies were identified through a systematic search of 7 databases using explicit criteria. Key concepts were identified and translated across studies. Findings were discussed and diagrammed during a series of audiotaped meetings. Results The final synthesis is grounded in findings from 27 studies, with over 500 participants (56% male) across 8 countries. All participants experienced a change in their self-identity from what was ‘familiar’ to ‘unfamiliar’. The transition process involved ‘finding new limits and a life worth living’ , ‘finding support for self’ and ‘finding a new normal’. Analyses of these concepts led to the generation of a third order construct, namely an ongoing process of ‘reassessing past, present and future lives’ as participants considered their changed identity. Participants experienced a strong urge to get back to ‘normal’. Support from family and friends could enable or constrain life change and lifestyle changes. Lifestyle change was but one small part of a wider ‘life’ change that occurred. Conclusions The final synthesis presents an interpretation, not evident in the primary studies, of a person-centred model to explain how lifestyle change is situated within ‘wider’ life changes. The magnitude of individual responses to a changed health status varied. Participants experienced distress as their notion of self identity shifted and emotions that reflected the various stages of the grief process were evident in participants’ accounts. The process of self-managing lifestyle took place through experiential learning; the level of engagement with lifestyle change reflected an individual’s unique view of the balance needed to manage ‘realistic change’ whilst leading to a life that was perceived as ‘worth living’. Findings highlight the importance of providing person centred care that aligns with both psychological and physical dimensions of recovery which are inextricably linked

    In situ study of fiber structure development of poly(butylene terephthalate) in a continuous laser-heated drawing process

    Get PDF
    The structural development of poly(butylene terephthalate) (PBT) fibers was analyzed using in situ wide angle X-ray diffraction and fiber temperature measurements during CO2 laser-heated drawing, in which the necking position on the running fiber could be fixed by CO2 laser irradiation. The measured parameters were determined as functions of the elapsed time after necking with a time resolution of 0.3 ms. The as-spun PBT fibers, which exhibited a low-oriented alpha-crystalline structure, were drawn to a draw ratio of 5 using laser heating. The (001') reflection, which indicates a quasi-smectic fibrillar structure, was not observed before crystallization in contrast to measurements of poly(ethylene terephthalate) (PET) and poly(ethylene 2,6-naphthalene dicarboxylate) (PEN). The alpha-crystal was transformed into an oriented beta-form crystal at the necking position, and the developed beta-crystallites exhibited increased size and altered orientation <2 ms after necking. The fiber temperature increased rapidly at around T-g, and the rearrangement of the beta-crystal primarily occurred as the fiber's temperature rose from 100 to 160 degrees C. The oriented beta-crystal of the drawn fiber transformed into the oriented beta-crystal when the drawing tension was released. Polymer Journal (2012) 44, 1030-1035; doi: 10.1038/pj.2012.65; published online 18 April 2012ArticlePOLYMER JOURNAL. 44(10):1030-1035 (2012)journal articl
    corecore