1,952 research outputs found

    Innovation of a Reinforcer Preference Assessment with the Difficult to Test

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    In this study, we continued evaluation of a two-choice preference assessment aimed at identifying a hierarchy of reinforcers for individuals with only one voluntary motor sequence—closing and releasing an adaptive switch. We assessed preferences among types of sensory stimulation in 6 adults with multiple profound impairments using concurrent synchronous reinforcement contingencies. Pre-experimental assessments with various types of stimulation led to the selection of music (A), vibration (B), and either olfactory or visual stimulation (C) as the 3 modalities for continued testing. Each participant received opportunities for familiarization with each type of stimulation in blocks of six 20-min sessions in which the closure of an adaptive switch produced the stimulation for as long as the switch remained closed. Next, participants could choose between pairs of types of stimulation in blocks of 12 sessions. In the first 6 of the 12 sessions, switch closure activated one type (e.g., A) and switch release activated the contrasted type (e.g., B). In the second 6 sessions, the contingencies were reversed. Two additional 12-session blocks completed all possible contrasts (AB, BC and AC). Four of the 6 participants showed distinct preferences in these two-choice tests with indications of preference hierarchies. The results demonstrate a method for obtaining indications of relative preference for potentially reinforcing stimuli from individuals without communication and without the abilities to act on more than one switch

    Teaching Individuals to Signal for Assistance in a Timely Manner

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    This is the peer reviewed version of the following article: Saunders, M. D., & Saunders, R. R. (2012). Teaching Individuals to Signal for Assistance in a Timely Manner. Behavioral Interventions : Theory & Practice in Residential & Community-Based Clinical Programs, 27(4), 10.1002/bin.1346. http://doi.org/10.1002/bin.1346, which has been published in final form at doi.org/10.1002/bin.1346. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingThe study describes the adaptive-switch performances of 8 adults with severe multiple impairments. Each was given a series of progressively more difficult discrimination tasks that, if solved, would require the participant to close the switch to activate a device that was not operating or to stay away from the switch if the device was operating. Then in a 2-choice format, a preference test was conducted by providing 2 devices simultaneously that could be activated or deactivated by closure or release of the switch. Finally, a preferred device was activated and then surreptitiously deactivated. Switch closures in this contingency activated a speech-generating device that played the message, “Help me.” All 8 participants learned to control devices using their adaptive switch, but only 4 participants learned to make a request for help. Reasons for the different performances across learners and nonlearners are discussed

    Establishing a Conditional Signal for Assistance in Teenagers with Blindness

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    Five teenagers with severe intellectual impairments and no discernible communication skills were enrolled in training to teach a conditional request for assistance using a speech-generating device (SGD). All were either blind or severely visually impaired since birth. All learned to operate an adaptive switch to control sensory outcomes, next showed preferences among sensory outcomes, and then demonstrated the ability to use their switch to signal for assistance with an SGD when the sensory outcome was remotely disabled. During the signaling phase, or subsequent attempts to generalize its use outside the laboratory, 3 participants began vocalizing. Most notably, they began imitation of the word “song” or the word “help” emitted by the SGD. The potential role of cause-and-effect training with adaptive switches is discussed

    The Finite Size Error in Many-body Simulations with long-Ranged Interactions

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    We discuss the origin of the finite size error of the energy in many-body simulation of systems of charged particles and we propose a correction based on the random phase approximation at long wave lengths. The correction comes from contributions mainly determined by the organized collective oscillations of the interacting system. Finite size corrections, both on kinetic and potential energy, can be calculated within a single simulation. Results are presented for the electron gas and silicon.Comment: 4 pages, 4 figures, submitted to PRL; corrected typo

    Adapted digital music players for individuals with severe impairments

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    This is the peer reviewed version of the following article: Saunders, M. D., Questad, K. A., Cullinan, T. B., & Saunders, R. R. (2011). Adapted Digital Music Players for Individuals with Severe Impairments. Behavioral Interventions : Theory & Practice in Residential & Community-Based Clinical Programs, 26(2), 10.1002/bin.327. http://doi.org/10.1002/bin.327, which has been published in final form at doi.org/10.1002/bin.327. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingPortable music production devices, such as radios, cassette players and MP3 players have characteristics that make them less than ideal for teaching the cause-and-effect relationships that would enable children and adults with severe impairments to control them independently and appropriately. Even when adapted for control with adaptive switches, the relationship between switch closure and on-off operation results in contingency characteristics that can inhibit learning. Some solutions to these problems are described, and for those individuals who can learn with complex contingencies, some promising products are reviewed

    Adolescent Dating Violence Victimization and Psychological Well-Being

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    This study assesses the relationship between adolescents' dating violence victimization and their psychological well-being. The participants were 190high school students, ages 13 to 19 years, with just over half being boys (53%) and the remainder being girls (47%). Data were collected using self-administered questionnaires. For girls, increasing levels of dating violence (severity, frequency, injury) were related to higher levels of post-traumatic stress and dissociation, even after controlling for demographic, family violence, and social desirability variables. For boys, the levels of victimization were related to higher levels of anxiety, depression, and posttraumatic stress, even after controlling for other variables. For both boys and girls, victimization was related to lower levels of life satisfaction, but not after controlling for the demographic, family violence, and social desirability variables. The research questions and findings are discussed in relation to the developmental challenges faced by adolescents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90512/1/Callahan-Tolman-Saunders 2003 Adolescent dating violence victimization JAR.pd

    Parasites of the invasive tilapia Oreochromis mossambicus: evidence for co-introduction

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    Reduced parasite species diversity and infection intensity on invasive populations can facilitate establishment and spread of invasive species. We investigated the parasite diversity of invasive populations of tilapia Oreochromis mossambicus from published literature and necropsies conducted on 72 fish captured in the Ross River, north Queensland, Australia. The parasite diversity of invasive O. mossambicus from 13 countries was compared to published reports on endemic populations in African river systems and tributaries to determine parasite species that had likely been co-introduced. In total, four parasite species were shared between native and invasive tilapia. We propose that these parasites (three monogeneans, Cichlidogyrus tilapiae Paperna, 1960, Cichlidogyrus sclerosus Paperna and Thurston, 1969, Cichlidogyrus halli (Price and Kirk, 1967) and one trichodinid Trichodina heterodentata Duncan, 1977) have likely been co-introduced with invasive Oreochromis mossambicus populations. Invasive Australian O. mossambicus had substantially reduced parasite diversity (five species) compared to cumulative parasite species diversity documented from the native region (23 species). Australian O. mossambicus were infected by two co-introduced parasites and three additional parasite species that have not been recorded previously on this species in Africa indicating possible parasite "spillback" from Australian natives or alternatively, acquisition from other introduced fauna. The substantially reduced parasite diversity on invasive Australian O. mossambicus could contribute to the ability of this species to become a serious fish pest

    Synthesis of luminescent silicon clusters by spark ablation

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    The synthesis of luminescent nanometer-scale Si clusters by spark ablation from a crystalline Si substrate is described. The cluster source, described in the text, generates clusters in a flowing Ar stream at atmospheric pressure. Electron microscopy reveals that the clusters have diameters in the 2-4 nm size range. The luminescence spectra of the clusters, similar to that of porous Si, are presented

    Host Galaxies Catalog Used in LIGO Searches for Compact Binary Coalescence Events

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    An up-to-date catalog of nearby galaxies considered as hosts of binary compact objects is provided with complete information about sky position, distance, extinction-corrected blue luminosity and error estimates. With our current understanding of binary evolution, rates of formation and coalescence for binary compact objects scale with massive-star formation and hence the (extinction-corrected) blue luminosity of host galaxies. Coalescence events in binary compact objects are among the most promising gravitational-wave sources for ground-based gravitational-wave detectors such as LIGO. Our catalog and associated error estimates are important for the interpretation of analyses, carried out for LIGO, to constrain the rates of compact binary coalescence, given an astrophysical population model for the sources considered. We discuss how the notion of effective distance, created to account for the antenna pattern of a gravitational-wave detector, must be used in conjunction with our catalog. We note that the catalog provided can be used on other astronomical analysis of populations that scale with galaxy blue luminosity.Comment: 29 pages, 7 figures, Accepted to Astrophysical Journal. To appear in March 20 2008 Astrophysical Journa

    Patient safety during procedural sedation using capnography monitoring: a systematic review and meta-analysis

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    OBJECTIVE: To evaluate the effect of capnography monitoring on sedation-related adverse events during procedural sedation and analgesia (PSA) administered for ambulatory surgery relative to visual assessment and pulse oximetry alone. DESIGN AND SETTING: Systematic literature review and random effects meta-analysis of randomised controlled trials (RCTs) reporting sedation-related adverse event incidence when adding capnography to visual assessment and pulse oximetry in patients undergoing PSA during ambulatory surgery in the hospital setting. Searches for eligible studies published between 1 January 1995 and 31 December 2016 (inclusive) were conducted in PubMed, the Cochrane Library and EMBASE without any language constraints. Searches were conducted in January 2017, screening and data extraction were conducted by two independent reviewers, and study quality was assessed using a modified Jadad scale. INTERVENTIONS: Capnography monitoring relative to visual assessment and pulse oximetry alone. PRIMARY AND SECONDARY OUTCOME MEASURES: Predefined endpoints of interest were desaturation/hypoxaemia (the primary endpoint), apnoea, aspiration, bradycardia, hypotension, premature procedure termination, respiratory failure, use of assisted/bag-mask ventilation and death during PSA. RESULTS: The literature search identified 1006 unique articles, of which 13 were ultimately included in the meta-analysis. Addition of capnography to visual assessment and pulse oximetry was associated with a significant reduction in mild (risk ratio (RR) 0.77, 95% CI 0.67 to 0.89) and severe (RR 0.59, 95% CI 0.43 to 0.81) desaturation, as well as in the use of assisted ventilation (OR 0.47, 95% CI 0.23 to 0.95). No significant differences in other endpoints were identified. CONCLUSIONS: Meta-analysis of 13 RCTs published between 2006 and 2016 showed a reduction in respiratory compromise (from respiratory insufficiency to failure) during PSA with the inclusion of capnography monitoring. In particular, use of capnography was associated with less mild and severe oxygen desaturation, which may have helped to avoid the need for assisted ventilation
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