3,198 research outputs found

    Why Um Helps Auditory Word Recognition: The Temporal Delay Hypothesis

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    Several studies suggest that speech understanding can sometimes benefit from the presence of filled pauses (uh, um, and the like), and that words following such filled pauses are recognised more quickly. Three experiments examined whether this is because filled pauses serve to delay the onset of upcoming words and these delays facilitate auditory word recognition, or whether the fillers themselves serve to signal upcoming delays in a way which informs listeners' reactions. Participants viewed pairs of images on a computer screen, and followed recorded instructions to press buttons corresponding to either an easy (unmanipulated, with a high-frequency name) or a difficult (visually blurred, low-frequency) image. In all three experiments, participants were faster to respond to easy images. In 50% of trials in each experiment, the name of the image was directly preceded by a delay; in the remaining trials an equivalent delay was included earlier in the instruction. Participants were quicker to respond when a name was directly preceded by a delay, regardless of whether this delay was filled with a spoken um, was silent, or contained an artificial tone. This effect did not interact with the effect of image difficulty, nor did it change over the course of each experiment. Taken together, our consistent finding that delays of any kind help word recognition indicates that natural delays such as fillers need not be seen as ‘signals’ to explain the benefits they have to listeners' ability to recognise and respond to the words which follow them

    Monte Carlo Simulations of Diffusion Weighted MRI in Myocardium: Validation and Sensitivity Analysis

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    A model of cardiac microstructure and diffusion MRI is presented, and compared with experimental data from ex vivo rat hearts. The model includes a simplified representation of individual cells, with physiologically correct cell size and orientation, as well as intra- to extracellular volume ratio. Diffusion MRI is simulated using a Monte Carlo model and realistic MRI sequences. The results show good correspondence between the simulated and experimental MRI signals. Similar patterns are observed in the eigenvalues of the diffusion tensor, the mean diffusivity (MD), and the fractional anisotropy (FA). A sensitivity analysis shows that the diffusivity is the dominant influence on all three eigenvalues of the diffusion tensor, the MD, and the FA. The area and aspect ratio of the cell cross-section affect the secondary and tertiary eigenvalues, and hence the FA. Within biological norms, the cell length, volume fraction of cells, and rate of change of helix angle play a relatively small role in influencing tissue diffusion. Results suggest that the model could be used to improve understanding of the relationship between cardiac microstructure and diffusion MRI measurements, as well as in testing and refinement of cardiac diffusion MRI protocols

    Evaluating eHealth: Undertaking Robust International Cross-Cultural eHealth Research

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    David Bates and Adam Wright discuss the opportunities and challenges of undertaking international collaborations in eHealth evaluation research, and make recommendations for moving forward

    Consolidating emerging evidence surrounding HIVST and HIVSS: A rapid systematic mapping protocol

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    BACKGROUND: HIV self-testing (HIVST) is becoming popular with policy makers and commissioners globally, with a key aim of expanding access through reducing barriers to testing for individuals at risk of HIV infection. HIV self-sampling (HIVSS) was available previously to self-testing but was confined mainly to the USA and the UK. It remains to be seen whether the momentum behind HIVST will also energise efforts to expand HIVSS. Recent years have seen a rapid growth in the type of evidence related to these interventions as well as several systematic reviews. The vast majority of this evidence relates to acceptability as well as values and preferences, although new types of evidence are emerging. This systematic map aims to consolidate all emerging evidence related to HIVST and HIVSS to respond to this rapidly changing area. METHODS: We will systematically search databases and the abstracts of five conferences from 2006 to the present date, with monthly-automated database searches. Searches will combine key terms relating to HIV (e.g. HIV, AIDS, human immune-deficiency syndrome) with terms related to self-testing (e.g. home-test, self-test, mail-test, home dried blood spot test). Abstracts will be reviewed against inclusion criteria in duplicate. Data will be manually extracted through a standard form and then entered to an open access relational map (HIVST.org). When new and sufficient evidence emerges which addresses existing knowledge gaps, we will complete a review on a relevant topic. DISCUSSION: This innovative approach will allow rapid cataloguing, documenting and dissemination of new evidence and key findings as they emerge into the public domain. SYSTEMATIC REVIEW REGISTRATION: This protocol has not been registered with PROSPERO as they do not register systematic maps

    Maternal allergic contact dermatitis causes increased asthma risk in offspring

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    <p>Abstract</p> <p>Background</p> <p>Offspring of asthmatic mothers have increased risk of developing asthma, based on human epidemiologic data and experimental animal models. The objective of this study was to determine whether maternal allergy at non-pulmonary sites can increase asthma risk in offspring.</p> <p>Methods</p> <p>BALB/c female mice received 2 topical applications of vehicle, dinitrochlorobenzene, or toluene diisocyanate before mating with untreated males. Dinitrochlorobenzene is a skin-sensitizer only and known to induce a Th1 response, while toluene diisocyanate is both a skin and respiratory sensitizer that causes a Th2 response. Both cause allergic contact dermatitis. Offspring underwent an intentionally suboptimal protocol of allergen sensitization and aerosol challenge, followed by evaluation of airway hyperresponsiveness, allergic airway inflammation, and cytokine production. Mothers were tested for allergic airway disease, evidence of dermatitis, cellularity of the draining lymph nodes, and systemic cytokine levels. The role of interleukin-4 was also explored using interleukin-4 deficient mice.</p> <p>Results</p> <p>Offspring of toluene diisocyanate but not dinitrochlorobenzene-treated mothers developed an asthmatic phenotype following allergen sensitization and challenge, seen as increased Penh values, airway inflammation, bronchoalveolar lavage total cell counts and eosinophilia, and Th2 cytokine imbalance in the lung. Toluene diisocyanate treated interleukin-4 deficient mothers were able to transfer asthma risk to offspring. Mothers in both experimental groups developed allergic contact dermatitis, but not allergic airway disease.</p> <p>Conclusion</p> <p>Maternal non-respiratory allergy (Th2-skewed dermatitis caused by toluene diisocyanate) can result in the maternal transmission of asthma risk in mice.</p

    Prognostic value of radical cystoprostatectomy in men with bladder cancer infiltrating prostate versus co-existing prostate cancer: a research study

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    <p>Abstract</p> <p>Background</p> <p>The aim of the following study is to evaluate the advancement of incidentally diagnosed prostate cancer in specimen after cystoprostatectomies caused by muscle-invasive bladder cancer. Secondly we assessed the survival in patients after radical cystoprostatectomy whose postoperative specimen was characterized by the presence of co-existing prostate cancer or prostate infiltration by urothelial bladder cancer.</p> <p>Methods</p> <p>Between 1993 and 2009 a total of 320 patients with muscle-invasive bladder cancer underwent cystoprostatectomy. The first analyzed group consisted of 52 patients with bladder cancer infiltrating prostate, while the second group consisted of 21 patients with co-existing prostate cancer. In all patients cancer specific survival and progression were analyzed. Average follow up was 75.2 months (range: 0 - 181).</p> <p>Results</p> <p>Cancer-specific survival was significantly shorter in group I (p = 0.03). Neoplastic progression in patients from group I was observed in 42.2% of patients, while in patients from group II in 23.6% of patients (p = 0.04). No statistical difference was observed in the percentage of positive lymph nodes between the groups (p = 0.22). The median Gleason score in patients with co-existing prostate cancer was equal to 5. The stage of prostate cancer pT<sub>2</sub>/pT<sub>3 </sub>was equal to 20 (96%)/1 (4%) patients. 12 (57%) prostate cancers were clinically insignificant. Biochemical recurrence occurred in 2 (9%) patients.</p> <p>Conclusions</p> <p indent="1">1. Incidentally diagnosed prostate cancer in specimen after cystoprostatectomies is frequently clinically insignificant and characterized by low progression.</p> <p indent="1">2. Patients with bladder cancer infiltrating prostate are characterized by higher percentage of progression and death in comparison with patients with co-existing prostate cancer.</p

    Using a computerized provider order entry system to meet the unique prescribing needs of children: description of an advanced dosing model

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    <p>Abstract</p> <p>Background</p> <p>It is well known that the information requirements necessary to safely treat children with therapeutic medications cannot be met with the same approaches used in adults. Over a 1-year period, Duke University Hospital engaged in the challenging task of enhancing an established computerized provider order entry (CPOE) system to address the unique medication dosing needs of pediatric patients.</p> <p>Methods</p> <p>An advanced dosing model (ADM) was designed to interact with our existing CPOE application to provide decision support enabling complex pediatric dose calculations based on chronological age, gestational age, weight, care area in the hospital, indication, and level of renal impairment. Given that weight is a critical component of medication dosing that may change over time, alerting logic was added to guard against erroneous entry or outdated weight information.</p> <p>Results</p> <p>Pediatric CPOE was deployed in a staggered fashion across 6 care areas over a 14-month period. Safeguards to prevent miskeyed values became important in allowing providers the flexibility to override the ADM logic if desired. Methods to guard against over- and under-dosing were added. The modular nature of our model allows us to easily add new dosing scenarios for specialized populations as the pediatric population and formulary change over time.</p> <p>Conclusions</p> <p>The medical needs of pediatric patients vary greatly from those of adults, and the information systems that support those needs require tailored approaches to design and implementation. When a single CPOE system is used for both adults and pediatrics, safeguards such as redirection and suppression must be used to protect children from inappropriate adult medication dosing content. Unlike other pediatric dosing systems, our model provides active dosing assistance and dosing process management, not just static dosing advice.</p

    Spatial complexity measure for characterising cellular automata generated 2D patterns

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    Cellular automata (CA) are known for their capacity to generate complex patterns through the local interaction of rules. Often the generated patterns, especially with multi-state two-dimensional CA, can exhibit interesting emergent behaviour. This paper addresses quantitative evaluation of spatial characteristics of CA generated patterns. It is suggested that the structural characteristics of two-dimensional (2D) CA patterns can be measured using mean information gain. This information-theoretic quantity, also known as conditional entropy, takes into account conditional and joint probabilities of cell states in a 2D plane. The effectiveness of the measure is shown in a series of experiments for multi-state 2D patterns generated by CA. The results of the experiments show that the measure is capable of distinguishing the structural characteristics including symmetry and randomness of 2D CA patterns
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