1,682 research outputs found

    An interface to virtual environments for people who are blind using Wii technology - mental models and navigation

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    Accessible games, both for serious and for entertainment purposes, would allow inclusion and participation for those with disabilities. Research into the development of accessible games, and accessible virtual environments, is discussed. Research into accessible Virtual Environments has demonstrated great potential for allowing people who are blind to explore new spaces, reducing their reliance on guides, and aiding development of more efficient spatial maps and strategies. Importantly, Lahav and Mioduser (2005, 2008) have demonstrated that, when exploring virtual spaces, people who are blind use more and different strategies than when exploring real physical spaces, and develop relatively accurate spatial representations of them. The present paper describes the design, development and evaluation of a system in which a virtual environment may be explored by people who are blind using Nintendo Wii devices, with auditory and haptic feedback. The nature of the various types of feedback is considered, with the aim of creating an intuitive and usable system. Using Wii technology has many advantages, not least of which are that it is mainstream, readily available and cheap. The potential of the system for exploration and navigation is demonstrated. Results strongly support the possibilities of the system for facilitating and supporting the construction of cognitive maps and spatial strategies. Intelligent support is discussed. Systems such as the present one will facilitate the development of accessible games, and thus enable Universal Design and accessible interactive technology to become more accepted and widespread

    There are no starless massive proto-clusters in the first quadrant of the Galaxy

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    We search the lambda = 1.1 mm Bolocam Galactic Plane Survey for clumps containing sufficient mass to form ~10^4 M\odot star clusters. 18 candidate massive proto-clusters are identified in the first Galactic quadrant outside of the central kiloparsec. This sample is complete to clumps with mass M(clump) > 10^4 M_sun and radius r < 2.5 pc. The overall Galactic massive cluster formation rate is CFR(M_cluster > 10^4) ~ 5 Myr^-1, which is in agreement with the rates inferred from Galactic open clusters and M31 massive clusters. We find that all massive proto-clusters in the first quadrant are actively forming massive stars and place an upper limit of t_starless < 0.5 Myr on the lifetime of the starless phase of massive cluster formation. If massive clusters go through a starless phase with all of their mass in a single clump, the lifetime of this phase is very short.Comment: Accepted to ApJL. See also Bressert et al 2012, http://arxiv.org/abs/1208.347

    Improving the Supply Distribution and Use of Antimalarial Drugs by the Private Sector in Tanzania. Report prepared for the National Malaria Control Programme, United Republic of Tanzania

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    Private pharmacies or shops are the source of 60% of the drugs bought to treat suspected cases of malaria. At the same time 59% of children fail to be treated within 24 hours of onset. The private sector is the primary source for antimalarials, but parents and carers are failing to administer those drugs sufficiently early to minimise morbidity and mortality. This review focused on the way in which antimalarial drugs reach the patient. It also examined ways in which the delivery system could be improved and how the private facilities can become more effective sources of both drugs and advice. It has found that there are many problems with the way that drugs are distributed. Many unregistered drugs are readily available, and poor storage conditions are likely to reduce the efficacy of drugs even if they were of good quality at the time of manufacture. For many people the cost of even the cheapest antimalarial is an issue and purchase of part doses is common. The knowledge of the staff in pharmacies is poor and in shops woefully inadequate. Nonetheless most people use shops and private pharmacies as their source for drugs. There are two overarching requirements: • First of all the needs and capabilities of the private sector must always be taken into account before any decision is made about how to make antimalarials more available. • Secondly, educating the staff and public will only be achieved through a subtle communications package regularly repeated and brought up to date. For example we found that many workers in Part II pharmacies remain in post for no more than one year. Unlike their counterparts in the public sector, staff in the private sector do not find incentives in attending training courses. Staff in the public sector spend so much time on courses that their time to actually implement what they have learned is limited. To reach the private sector staff will require subtler and more cost effective methods. The report is full of detailed recommendations for the improvement of the supply systems and for educating both staff and public

    Specific antibodies against vaccine-preventable infections: a mother-infant cohort study

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    OBJECTIVES: To determine maternal and neonatal specific antibody levels to selected vaccine-preventable infections (pertussis, Haemophilus influenzae type b (Hib), tetanus and pneumococcus). DESIGN: Prospective cohort study. SETTING: A UK secondary care maternity unit (March 2011-January 2012). PARTICIPANTS: Mothers and infants within 72 h of delivery were eligible. Unwell individuals, mothers less than 18 years of age, and infants born at less than 36 weeks gestation, or weighing less than 2500 g, were excluded. HIV-infected mothers were included. 112 mother-infant pairs were recruited. Samples from 111 mothers and 109 infants (108 pairs) were available for analysis. OUTCOME MEASURES: Specific antibody levels were determined using standard commercial ELISAs. Specific antibody to pertussis antigens (PT and FHA) of >50 IU/ml, defined as 'positive' by the test manufacturer, were interpreted as protective. Antitetanus antibody titres >0.1 IU/ml and anti-Hib antibody titres >1 mg/l were regarded as protective. RESULTS: Only 17% (19/111) of women exhibited a protective antibody response against pertussis. 50% (56/111) of women had levels of antibody protective against Hib and 79% (88/111) against tetanus. There was a strong positive correlation between maternal-specific and infant-specific antibodies' responses against pertussis (rs=0.71, p<0.001), Hib (rs=0.80, p<0.001), tetanus (rs=0.90, p<0.001) and pneumococcal capsular polysaccharide (rs=0.85, p<0.001). Only 30% (33/109) and 42% (46/109) of infants showed a protective antibody response to pertussis and Hib, respectively. Placental transfer (infant:mother ratio) of specific IgG to pertussis, Hib, pneumococcus and tetanus was significantly reduced from HIV-infected mothers to their HIV-exposed, uninfected infants (n=12 pairs) compared with HIV-uninfected mothers with HIV-unexposed infants (n=96 pairs) by 58% (<0.001), 61% (<0.001), 28% (p=0.034) and 32% (p=0.035), respectively. CONCLUSIONS: Low baseline antibody levels against pertussis in this cohort suggest the recently implemented UK maternal pertussis immunisation programme has potential to be effective

    THE ONSET OF MASSIVE STAR FORMATION: THE EVOLUTION OF TEMPERATURE AND DENSITY STRUCTURE IN AN INFRARED DARK CLOUD

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    We present new NH3 (1, 1), (2, 2), and (4, 4) observations from the Karl G. Jansky Very Large Array compiled with work in the literature to explore the range of conditions observed in young, massive star-forming regions. To sample the effects of evolution independent from those of distance/resolution, abundance, and large-scale environment, we compare clumps in different evolutionary stages within a single infrared dark cloud (IRDC), G32.02+0.06. We find that the early stages of clustered star formation are characterized by dense, parsec-scale filamentary structures interspersed with complexes of dense cores (60 pc) hosting the IRDC, hypothesizing that it may have been shaped by previous generations of massive stars

    Characterizing precursors to stellar clusters with Herschel

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    Context. Despite their profound effect on the universe, the formation of massive stars and stellar clusters remains elusive. Recent advances in observing facilities and computing power have brought us closer to understanding this formation process. In the past decade, compelling evidence has emerged that suggests infrared dark clouds (IRDCs) may be precursors to stellar clusters. However, the usual method for identifying IRDCs is biased by the requirement that they are seen in absorption against background mid-IR emission, whereas dust continuum observations allow cold, dense pre-stellar-clusters to be identified anywhere. Aims: We aim to understand what dust temperatures and column densities characterize and distinguish IRDCs, to explore the population of dust continuum sources that are not IRDCs, and to roughly characterize the level of star formation activity in these dust continuum sources. Methods: We use Hi-GAL 70 to 500 mdatatoidentifydustcontinuumsourcesintheell=30degandell=59degHiGALsciencedemonstrationphase(SDP)fields,tocharacterizeandsubtracttheGalacticcirrusemission,andperformpixelbypixelmodifiedblackbodyfitsoncirrussubtractedHiGALsources.WeutilizearchivalSpitzerdatatoindicatethelevelofstarformingactivityineachpixel,frommidIRdarktomidIRbright.Results:WepresenttemperatureandcolumndensitymapsintheHiGALell=30degandell=59degSDPfields,aswellasarobustalgorithmforcirrussubtractionandsourceidentificationusingHiGALdata.WereportonthefractionofHiGALsourcepixelswhicharemidIRdark,midIRneutral,ormidIRbrightinbothfields.WefindsignificanttrendsincolumndensityandtemperaturebetweenmidIRdarkandmidIRbrightpixels;midIRdarkpixelsareabout10Kcolderandhaveafactorof2highercolumndensityonaveragethanmidIRbrightpixels.WefindthatHiGALdustcontinuumsourcesspanarangeofevolutionarystatesfrompretostarforming,andthatwarmersourcesareassociatedwithmorestarformationtracers.Additionally,thereisatrendofincreasingtemperaturewithtracertypefrommidIRdarkatthecoldest,tooutflow/masersourcesinthemiddle,andfinallyto8and24m data to identify dust continuum sources in the ell = 30deg and ell = 59deg Hi-GAL science demonstration phase (SDP) fields, to characterize and subtract the Galactic cirrus emission, and perform pixel-by-pixel modified blackbody fits on cirrus-subtracted Hi-GAL sources. We utilize archival Spitzer data to indicate the level of star-forming activity in each pixel, from mid-IR-dark to mid-IR-bright. Results: We present temperature and column density maps in the Hi-GAL ell = 30deg and ell = 59deg SDP fields, as well as a robust algorithm for cirrus subtraction and source identification using Hi-GAL data. We report on the fraction of Hi-GAL source pixels which are mid-IR-dark, mid-IR-neutral, or mid-IR-bright in both fields. We find significant trends in column density and temperature between mid-IR-dark and mid-IR-bright pixels; mid-IR-dark pixels are about 10 K colder and have a factor of 2 higher column density on average than mid-IR-bright pixels. We find that Hi-GAL dust continuum sources span a range of evolutionary states from pre- to star-forming, and that warmer sources are associated with more star formation tracers. Additionally, there is a trend of increasing temperature with tracer type from mid-IR-dark at the coldest, to outflow/maser sources in the middle, and finally to 8 and 24 m bright sources at the warmest. Finally, we identify five candidate IRDC-like sources on the far-side of the Galaxy. These are cold (20 K), high column density (N(H2_2) gt 1022^22 cm2^-2) clouds identified with Hi-GAL which, despite bright surrounding mid-IR emission, show little to no absorption at 8 $m. These are the first inner Galaxy far-side candidate IRDCs of which the authors are aware. Herschel in an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation by NASA.The FITS files discussed in the paper would be released publicly WITH the Hi-GAL data (on the Hi-GAL website) when the Hi-GAL data is released publicly.Peer reviewe

    A low cost virtual reality system for home based rehabilitation of the arm following stroke: a randomised controlled feasibility trial

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    OBJECTIVE: To assess the feasibility of conducting a randomised controlled trial of a home-based virtual reality system for rehabilitation of the arm following stroke. DESIGN: Two group feasibility randomised controlled trial of intervention versus usual care. SETTING: Patients' homes. PARTICIPANTS: Patients aged 18 or over, with residual arm dysfunction following stroke and no longer receiving any other intensive rehabilitation. INTERVENTIONS: Eight weeks' use of a low cost home-based virtual reality system employing infra-red capture to translate the position of the hand into game play or usual care. MAIN MEASURES: The primary objective was to collect information on the feasibility of a trial, including recruitment, collection of outcome measures and staff support required. Patients were assessed at three time points using the Wolf Motor Function Test, Nine-Hole Peg Test, Motor Activity Log and Nottingham Extended Activities of Daily Living. RESULTS: Over 15 months only 47 people were referred to the team. Twenty seven were randomised and 18 (67%) of those completed final outcome measures. Sample size calculation based on data from the Wolf Motor Function Test indicated a requirement for 38 per group. There was a significantly greater change from baseline in the intervention group on midpoint Wolf Grip strength and two subscales of the final Motor Activity Log. Training in the use of the equipment took a median of 230 minutes per patient. CONCLUSIONS: To achieve the required sample size, a definitive home-based trial would require additional strategies to boost recruitment rates and adequate resources for patient support

    THE COMPARISON OF PHYSICAL PROPERTIES DERIVED FROM GAS AND DUST IN A MASSIVE STAR-FORMING REGION

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    We explore the relationship between gas and dust in a massive star-forming region by comparing the physical properties derived from each. We compare the temperatures and column densities in a massive star-forming Infrared Dark Cloud (G32.02+0.05), which shows a range of evolutionary states, from quiescent to active. The gas properties were derived using radiative transfer modeling of the (1,1), (2,2), and (4,4) transitions of NH3 on the Karl G. Jansky Very Large Array, while the dust temperatures and column densities were calculated using cirrus-subtracted, modified blackbody fits to Herschel data. We compare the derived column densities to calculate an NH3 abundance, χNH3_{{\rm NH}_{3}} = 4.6 × 10–8. In the coldest star-forming region, we find that the measured dust temperatures are lower than the measured gas temperatures (mean and standard deviations T dust, avg ~ 11.6 ± 0.2 K versus T gas, avg ~ 15.2 ± 1.5 K), which may indicate that the gas and dust are not well-coupled in the youngest regions (~0.5 Myr) or that these observations probe a regime where the dust and/or gas temperature measurements are unreliable. Finally, we calculate millimeter fluxes based on the temperatures and column densities derived from NH3, which suggest that millimeter dust continuum observations of massive star-forming regions, such as the Bolocam Galactic Plane Survey or ATLASGAL, can probe hot cores, cold cores, and the dense gas lanes from which they form, and are generally not dominated by the hottest core
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