489 research outputs found

    Exploring Dual-Camera-Based Augmented Reality for Cultural Heritage Sites

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    Context: Augmented Reality (AR) provides a novel approach for presenting cultural heritage content. Recent advances in AR research and the uptake of powerful mobile devices means AR is a viable option for heritage institutions, but there are challenges that must be overcome before high-quality AR is commonplace. Aims: This project details the development of an AR “magic camera” system featuring novel dual-camera marker-based tracking, allowing users to take AR photos at outdoor heritage sites using a tablet computer. The aims of the project were to assess the feasibility of the tracking method, evaluate the usability of the AR system, and explore implications for the heritage sector. Method: A prototype system was developed. A user study was designed, where participants had to recreate reference images as closely as possible using an iPad and the AR system around the University grounds. Data, such as completion time and error rates, were collected for analysis. The images produced were rated for quality by three experts. Results: Participants responded positively to the system, and the new tracking method was used successfully. The usability study uncovered a number of issues, most of which are solvable in future software versions. However, some issues, such as difficulty orientating objects, rely on improving hardware and software before they can be fixed, but these problems did not affect the quality of the images produced. Participants completed each task more quickly after initial slowness, and while the system was frustrating for some, most found the experience enjoyable. Conclusion: The study successfully uncovered usability problems. The dual-camera tracking element was successful, but the marker-based element encountered lighting problems and high false-positive rates. Orientating objects using inertial sensors was not intuitive; more research in this area would be beneficial. The heritage sector must consider development, maintenance and training costs, and site modification issues

    SYSTEM AND METHOD FOR AUTHENTICATION USING MOBILE DEVICE

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    The methods and system disclosed in present disclosure is to perform authentication of a user device before provisioning card details in a digital wallet. In present disclosure, user taps user device on mobile device, upon tapping interaction data is sent to user device. The user device further generates cryptogram using interaction data and credentials of user device. The cryptogram generated is sent to server computer, which verifies whether card details can be provisioned by sending token request to token service computer which further sends authentication request to authentication server system. The authentication server system authenticates received cryptogram and generates validation result either to be successful or to be a failure. The validation result is sent to token service system which in turn sends token response to server computer. Further, server computer decides whether to provision and store the card details and the token received based on token response. Finally, result of provisioning is updated to the user through the mobile device. Hence, the method and the system of the present disclosure eases the provisioning process for cardholders by removing the need to manually enter card details or take a photo of the card and provides assurance that the genuine card is in the possession of individual initiating the provisioning request

    Effect of plyometric training on swimming block start performance in adolescents

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    This study aimed to identify the effect of plyometric training (PT), when added to habitual training (HT) regimes, on swim start performance. After the completion of a baseline competitive swim start, 22 adolescent swimmers were randomly assigned to either a PT (n = 11, age: 13.1 ± 1.4 yr, mass: 50.6 ± 12.3 kg, stature: 162.9 ± 11.9 cm) or an HT group (n = 11, age: 12.6 ± 1.9 yr, mass: 43.3 ± 11.6 kg, stature: 157.6 ± 11.9 cm). Over an 8-week preseason period, the HT group continued with their normal training program, whereas the PT group added 2 additional 1-hour plyometric-specific sessions, incorporating prescribed exercises relating to the swimming block start (SBS). After completion of the training intervention, post-training swim start performance was reassessed. For both baseline and post-trials, swim performance was recorded using videography (50Hz Canon MVX460) in the sagital plane of motion. Through the use of Silicon Coach Pro analysis package, data revealed significantly greater change between baseline and post-trials for PT when compared with the HT group for swim performance time to 5.5 m (−0.59 s vs. −0.21 s; p < 0.01) and velocity of take-off to contact (0.19 ms−1 vs. −0.07 ms−1; p < 0.01). Considering the practical importance of a successful swim start to overall performance outcome, the current study has found that inclusion of suitable and safely implemented PT to adolescent performers, in addition to HT routines, can have a positive impact on swim start performance

    Analysis of breeding systems, ploidy, and the role of hexaploids in three Hypericum perforatum L. populations

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    Hexaploid seeds are produced by predominantly tetraploid populations of Hypericum perforatum, but the fate of hexaploid seedlings and their reproductive behavior have not been closely examined. We used flow cytometry to analyze single seeds and individual plant samples of three accessions of H. perforatum to determine ploidy levels and reproductive pathways. Seed samples of all three accessions were facultative apomicts, with tetraploid cytotype predominant (85–91%) and a lower frequency of hexaploids (9–14%), with diploids (5%) detected in only one population. Seedling populations consisted of tetraploids (87–97%) and hexaploids (3–13%). Hexaploid embryos are most likely generated by a 2n gamete of the tetraploid and fertilized by a normal, reduced tetraploid male gamete. These hexaploids are expected to produce unbalanced gametes because they possess chromosome complements that include two triploid sets originally derived from two different species. The observation that some tetraploid seeds had endosperm with high cellular DNA content indicates that some unbalanced male gametes produced by hexaploids were evidently viable and could effect fertilization. Whether this mechanism is also true for egg cells or whether the hexaploids are capable of producing unreduced embryo sacs is uncertain. Because of severe reproductive difficulties, hexaploid seedlings may play a very minor role in gene flow and the further evolution of H. perforatum. The likelihood that hexaploids will evolve to types with an increased frequency of bivalent paring in meiosis is relatively low. However, hexaploids may include novel chemotypes, which could be vegetatively propagated if valuable, medicinal types can be identified among them

    Targeted immune interventions for type 1 diabetes: not as easy as it looks!

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    PURPOSE OF REVIEW: Although insulin is lifesaving and sustaining for those with type 1 diabetes (T1D), curing the disease will be much more complex than simple replacement of this hormone. T1D is an autoimmune disease orchestrated by T cells, and includes many arms of the immune response. Tremendous effort has gone into understanding its underlying immune, genetic, and environmental causes, and this progress has led to immunologically based clinical trials in T1D. This review will focus primarily on the clinical trials of the past decade that have attempted to translate these fundamental findings. RECENT FINDINGS: It is known that powerful, nonspecific immune suppressants can temporarily slow the course of newly diagnosed T1D, yet are too toxic for long-term use, especially in children. Recent clinical trials to reverse T1D have used newly developed therapies that target specific components of the immune process believed to be involved with T1D. Although well justified and designed, no recent approach has resulted in clinical remission and few have had any effect on disease course. SUMMARY: Advances in our fundamental understanding of how the human diabetes immune response is activated and regulated coupled with lessons that have been learnt from the most recent era of completed trials are guiding us toward the development of more effective, multipronged therapies to ablate diabetes autoimmunity, restore immune tolerance, preserve β cells, and, ultimately, improve the lives of patients with T1D

    Propofol-Based Procedural Sedation with or without Low-Dose Ketamine in Children

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    Objective Examine comparative dosing, efficacy, and safety of propofol alone or with an initial, subdissociative dose of ketamine approach for deep sedation. Background Propofol is a sedative-hypnotic agent used increasingly in children for deep sedation. As a nonanalgesic agent, use in procedures (e.g., bone marrow biopsies/aspirations, renal biopsies) is debated. Our intensivist procedural sedation team sedates using one of two protocols: propofol-only (P-O) approach or age-adjusted dose of 0.25 or 0.5 mg/kg intravenous ketamine (K + P) prior to propofol. With either approach, an initial induction dose of 1 mg/kg propofol is recommended and then intermittent dosing throughout the procedure to achieve adequate sedation to safely and effectively perform the procedure. Approach: Retrospective evaluation of 754 patients receiving either the P-O or K + P approach to sedation. Results A total of 372 P-O group patients and 382 K + P group. Mean age (7.3 ± 5.5 years for P-O; 7.3 ± 5.4 years for K + P) and weight (30.09 ± 23.18 kg for P-O; 30.14 ± 24.45 kg for K + P) were similar in both groups (p = NS). All patients successfully completed procedures with a 16% combined incidence of hypoxia (SPO2 < 90%). Procedure time was 3 minutes longer for K + P group than P-O group (18.68 ± 15.13 minutes for K + P; 15.11 ± 12.77 minutes for P-O; p < 0.01), yet recovery times were 5 minutes shorter (17.04 ± 9.36 minutes for K + P; 22.17 ± 12.84 minutes for P-O; p < 0.01). Mean total dose of propofol was significantly greater in P-O than in K + P group (0.28 ± 0.20 mg/kg/min for K + P; 0.40 ± 0.26 mg/kg/min for P-O; p < 0.0001), and might explain the shorter recovery time. Conclusion Both sedation approaches proved to be well tolerated and equally effective. Addition of ketamine was associated with reduction in the recovery time, probably explained by the statistically significant decrease in the propofol dose

    Factors associated with survival during high frequency oscillatory ventilation in children

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    Our aim is to determine indicators of survival in children with severe hypoxic respiratory failure (HRF) after transition to high-frequency oscillatory ventilation (HFOV). Single-center retrospective examination of children with HRF transitioned to HFOV. Blood gases and ventilator settings 24 hours prior to and 48 hours after HFOV in survivors and nonsurvivors were evaluated. Sixty-two children with mean age of 7 years and mean weight of 26 kg were included with an observed mortality of 29%. Mean airway pressures (Paw), oxygenation index (OI), arterial oxygen partial pressure (PaO2)/fraction of inspired oxygen (FiO2) (P/F) ratio, pH, bicarbonate, and arterial carbon dioxide partial pressure were similar prior to HFOV in survivors and nonsurvivors. During HFOV, mean OI and P/F ratio improved in both groups with an average Paw increase of ∼10 cm H2O. Survivors had lower OI than nonsurvivors (21 ± 0.9 vs. 26.5 ± 2.2; p 200. Survivors had higher pH than nonsurvivors at 36 hours (7.40 ± 0.01 vs. 7.32 ± 0.02; p < 0.05), higher bicarbonate levels (27.1 ± 0.7 vs. 23.9 ± 1.3 mEq/L), and similar arterial carbon dioxide partial pressure with less oscillatory support (i.e., hertz and amplitude). Inhaled nitric oxide was used in 53% of patients with improvements in oxygenation but with no effect on mortality. HFOV improves oxygenation in children with severe HRF. Nonsurvivors can be distinguished from survivors at 24 to 36 hours during HFOV by higher OI, metabolic acidosis, and higher oscillatory support. These data may assist in prognostication or timing of initiating alternative therapies, such as extracorporeal membrane oxygenation

    Video Media in the Hyperconnected Age: Investigating Emergent Viewing Practices

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    Recent technological developments have changed the way video is consumed. The uptake of fast internet connections and ubiquitous mobile devices mean that people can watch via on demand services, and that viewers often media multitask with phones and tablets during viewing. This thesis examines on-demand viewing and media multitasking with mobile devices in detail. Two situated studies extend our understanding of these behaviours through video observation and diary studies. It was found that using mobile devices while viewing was common, though subject to different usage patterns and individual differences. Self-reported media multitasking propensity correlated with observational data, suggesting that some people consistently media multitask more than others. People valued the freedom and choice provided by on-demand services, which drove their popularity. Viewing occurred in a range of contexts and on a variety of devices. However, some were concerned that it was difficult to limit their viewing. In order to quantify viewer experience, a questionnaire was developed to measure immersion. This was used in two lab experiments investigating specific behaviours that were previously observed: watching on screens of different sizes; and being interrupted by notifications while watching. It was found that both watching on small screens and interruptions from notifications negatively affected immersion. The findings of this research affect viewers, content producers, and TV networks. To preserve and improve viewing experiences, stakeholders should be mindful of both positive and negative effects when considering personal usage and the development of new viewing technologies
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