Self-Concept and Emotional Well-Being in Individuals with Developmental Disabilities Involved in Special Olympics

Individuals with developmental disabilities (DD) are known to have lower levels of physical and social self-concept and emotional well-being compared to typically developing individuals. Little is known about the individual and family predictors of these constructs, and researchers have typically relied on proxy measures rather than self-report. In a sample of 51 caregivers and 51 athletes with DD involved in Special Olympics (SO), we examined the individual predictors (e.g., age, sex, BMI, emotional and behavioural problems, and SO participation) and family predictors (e.g., caregiver mental health, family functioning, and expressed emotion) of self-reported physical and social self-concept (Study One) and emotional well-being (Study Two). Age, total difficulties, and SO participation were significantly related to social self-concept, whereas age and BMI were significantly related to physical self-concept. None of the family factors were related to either social or physical self-concept. Both individual factors and family factors (i.e., BMI, emotional and behavioural problems, prosocial behaviour, expressed emotion, and family functioning) were significantly related to indicators of emotional well-being. The results have important implications for understanding and promoting social and physical self-concept and emotional well-being in individuals with DD

Measurement of the elastic scattering cross section of neutrons from argon and neon

Background: The most significant source of background in direct dark matter searches are neutrons that scatter elastically from nuclei in the detector's sensitive volume. Experimental data for the elastic scattering cross section of neutrons from argon and neon, which are target materials of interest to the dark matter community, were previously unavailable. Purpose: Measure the differential cross section for elastic scattering of neutrons from argon and neon in the energy range relevant to backgrounds from (alpha,n) reactions in direct dark matter searches. Method: Cross-section data were taken at the Triangle Universities Nuclear Laboratory (TUNL) using the neutron time-of-flight technique. These data were fit using the spherical optical model. Results: The differential cross section for elastic scatting of neutrons from neon at 5.0 and 8.0 MeV and argon at 6.0 MeV was measured. Optical-model parameters for the elastic scattering reactions were determined from the best fit to these data. The total elastic scattering cross section for neon was found to differ by 6% at 5.0 MeV and 13% at 8.0 MeV from global optical-model predictions. Compared to a local optical-model for 40Ar, the elastic scattering cross section was found to differ from the data by 8% at 6.0 MeV. Conclusions: These new data are important for improving Monte-Carlo simulations and background estimates for direct dark matter searches and for benchmarking optical models of neutron elastic scattering from these nuclei

Slit coordinates cardiac morphogenesis in Drosophila

AbstractSlit is a secreted guidance cue that conveys repellent or attractive signals from target and guidepost cells. In Drosophila, responsive cells express one or more of three Robo receptors. The cardial cells of the developing heart express both Slit and Robo2. This is the first report of coincident expression of a Robo and its ligand. In slit mutants, cardial cell alignment, polarization and uniform migration are disrupted. The heart phenotype of robo2 mutants is similar, with fewer migration defects. In the guidance of neuronal growth cones in Drosophila, there is a phenotypic interaction between slit and robo heterozygotes, and also with genes required for Robo signaling. In contrast, in the heart, slit has little or no phenotypic interaction with Robo-related genes, including Robo2, Nck2, and Disabled. However, there is a strong phenotypic interaction with Integrin genes and their ligands, including Laminin and Collagen, and intracellular messengers, including Talin and ILK. This indicates that Slit participates in adhesion or adhesion signaling during heart development

Characterizing New Calibration Sources in Liquid Xenon Dark Matter Searches

In order to use the XENON1T liquid xenon detector as a means for detecting dark matter, the response to nuclear and electronic recoils must be well calibrated. Electronic-recoil calibration of XENON1T will be done by using the noble gas radon-220 that emanates from a custom thorium-228 source to observe the electron recoils that its daughter elements induce in liquid xenon. A silicon PIN diode was constructed to ensure that the Th228 source does not contaminate the system with the long-lived isotopes Th228 (T1/2 of 1.9 y) or Radium-224 (T1/2 of 3.6 d). The PIN diode was fixed in a custom vacuum vessel capable of being mounted inline on a gas system. The response of the silicon PIN diode was calibrated with standard alpha particle sources, and the integrated background rate from 2-10 MeV was measured to be (3.21±0.26)x10E-4 counts/sec. With xenon gas flowing over the source and through the vessel, the measured alpha particle count rate due to Th228 and Ra224 are consistent with background levels. These initial results are promising, and imply a negligible increase in the overall XENON1T background level

Validation of the Background Model for the MAJORANA DEMONSTRATOR

The observation of neutrinoless double-beta decay would confirm the Majorana nature of the neutrino and would allow one to potentially determine the mass of neutrinos. The goal of the MAJORANA collaboration is to develop a tonne-scale Ge-76-based neutrinoless double-beta decay experiment. Currently, efforts are underway to construct the MAJORANA DEMONSTRATOR, a 44.8-kg array of germanium crystals, located at the 4850' level of the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to demonstrate the ability to construct a detector composed of an array of germanium crystals while maintaining an unprecedented low background that is essential for the observation of neutrinoless double-beta decay. Before the assembly and operation of the DEMONSTRATOR, a single test cryostat was built. This cryostat, referred to as the Prototype Cryostat, was built to test the clean assembly procedures that are to be used for the DEMONSTRATOR. Understanding the backgrounds of the MAJORANA DEMONSTRATOR is of the upmost importance and for this reason, much effort has been put into creating an accurate background model. While achieving the lowest possible background is the goal of the DEMONSTRATOR, this is not necessarily true of the Prototype Cryostat, whose main purpose is to improve on cryostat assembly procedures, analysis routines and the like. Nevertheless, understanding the backgrounds of the Prototype Cryostat can help to verify the background model of the DEMONSTRATOR. Thus a background model of the Prototype Cryostat has been developed using the same techniques that are being used to develop the background model of the DEMONSTRATOR. This dissertation discusses the development of the Prototype Cryostat background model, its successes and failures, and the implications for the DEMONSTRATOR.Doctor of Philosoph

Elastic and Inelastic Scattering of Neutrons from Neon and Argon: Impact on Neutrinoless Double-Beta Decay and Dark Matter Experimental Programs

In underground physics experiments, such as neutrinoless double-beta decay and dark matter searches, fast neutrons may be the dominant and potentially irreducible source of background. Experimental data for the elastic and inelastic scattering cross sections of neutrons from argon and neon, which are target and shielding materials of interest to the dark matter and neutrinoless double-beta decay communities, were previously unavailable. Unmeasured neutron scattering cross sections are often accounted for incorrectly in Monte-Carlo simulations. Elastic scattering cross sections were measured at the Triangle Universities Nuclear Laboratory (TUNL) using the neutron time-of-flight technique. Angular distributions for neon were measured at 5.0 and 8.0 MeV. One full angular distribution was measured for argon at 6.0 MeV. The cross-section data were compared to calculations using a global optical model. Data were also fit using the spherical optical model. These model fits were used to predict the elastic scattering cross section at unmeasured energies and also provide a benchmark where the global optical models are not well constrained. Partial gamma-ray production cross sections for (n,xng) reactions in natural argon and neon were measured using the broad spectrum neutron beam at the Los Alamos Neutron Science Center (LANSCE). Neutron energies were determined using time of flight and resulting gamma rays from neutron-induced reactions were detected using the GErmanium Array for Neutron Induced Excitations (GEANIE). Partial gamma-ray production cross sections for six transitions in 40Ar, two transitions in 39Ar and the first excited state transitions is 20Ne and 22Ne were measured from threshold to a neutron energy where the gamma-ray yield dropped below the detection sensitivity. Measured (n,xng) cross sections were compared with calculations using the TALYS and CoH3 nuclear reaction codes. These new measurements will help to identify potential backgrounds in neutrinoless double-beta decay and dark matter experiments that use argon or neon. The measurements will also aid in the identification of neutron interactions in these experiments through the detection of gamma rays produced by (n,xng) reactions.Doctor of Philosoph

Mild traumatic brain injury and post traumatic epilepsy: biological relevance and strategies for treatment

INTRO: There is mounting evidence to suggest a causal link between mild traumatic brain injury (mTBI) and post traumatic epilepsy (PTE). Significant ranges in the methods and definitions of “mild” TBI, each with their own limitations, make drawing cohesive conclusions from the state of the literature difficult. However, this body of work attempts to compile the literature in order to better elucidate the relationship between these populations. Ultimately, I hope this source to be a useful reference for understanding the state of the research such that one can make critical considerations in the future design of methods to definitively improve the quality of work in this field. Meaningful improvements could radically improve the outcomes for the millions of people who suffer as a result of these injuries and their lasting implications. METHODS: PubMed searches used keywords: Traumatic Brain injury (mild), Epilepsy, Concussion, Loss of cortical inhibition, Post Traumatic Epilepsy. Combinations of terms including mTBI or PTE AND MRI, fMRI, DTI, MRS, Biomarkers, TMS, EEG, and pathology. RESULTS: Strong trends persist despite the limitation in consistency of terminology and methods. Relative risk scores between 1.5 and 2.2 percent have been established across multiple long-term studies across decades of research and millions of person years, a 2-3-fold change over the baseline incidence of epilepsy in the general population (0.7%; less than one in every 100). Preclinical studies in mice have recently shown progressive increased seizure susceptibility after repeated mTBI. Within the first three weeks after injury, Glutamate homeostasis is altered meaningfully. Increased neural excitability results as the balance between excitation and inhibition shifts in the brain. An increased Glu/GABA ratio has also been linked to dysfunction in GABAergic cell populations, including parvalbumin positive inhibitory interneurons (PVI). Oxidative stress, as measured by a decreased GSH/GSSG ratio, suggests a dysregulation in homeostatic processes than can outlive clinical symptoms. Animals also display a decreased latency to induced seizure by Pentelynetetrazole (PTZ) a potent GABA receptor antagonist. Six weeks after injury, these mice have been shown to display; decreased GABA driving an increased Glu/GABA ratio, decreased EEG gamma power, and prominent signs of gliosis involving both astrocytes and microglia. Clinical investigations into the biology of this injury, utilizing a wide range of techniques, point to a loss of cortical inhibitory tone, an early hallmark of PTE. TMS findings of both reduced resting motor threshold and a shorter cortical silent period suggest a loss of cortical inhibitory tone likely shifting the excitation/inhibition balance. Signs of microstructural damage and altered cell permeability point to a disruption in chemical gradients which leads to greater functional deficits, as the parameters for normal cell function are no longer maintained. Changes in function and metabolism have been shown to outlast many of the behavioral and acute clinical symptoms suggesting a slow development but long duration of this insidious process. CONCLUSION: Mechanisms that link mTBI to PTE include a loss of cortical inhibition, increased oxidative stress and gliosis which over time increases Glu/GABA ratio, in turn increasing the likelihood of developing epilepsy. Although the relationship between mTBI and PTE has been suggested before through epidemiological studies, there is now emerging biochemical evidence to better describe this connection. Due to the high incidence of mTBI, any small increase in risk to develop PTE pursuant to concussion will affect millions of lives. With this new evidence, treatments can be designed to halt the progression and alleviate symptoms for those afflicted. The investigation of the biological mechanisms that link concussion and epilepsy is a critical step in developing treatment strategies and prophylaxis that could prove to be crucial for so many

Parent Empowerment and Mental Health: Understanding Parent Perceptions of the Educational Experience

Parents of children with autism spectrum disorders (ASD) are important partners with schools in ensuring effective education, and it is important to examine the factors that influence parent perceptions of their children’s educational experience. The purpose of this study was to investigate the relations among parent empowerment, parent mental health, and perceptions of children’s educational experience in 176 parents of children with ASD. Parent empowerment and mental health were found to be significant predictors of parents’ perceptions of their child’s educational experience. The importance of understanding constructs such as empowerment and mental health and how they relate to school satisfaction is discussed

Low-Background gamma counting at the Kimballton Underground Research Facility

The next generation of low-background physics experiments will require the use of materials with unprecedented radio-purity. A gamma-counting facility at the Kimballton Underground Research Facility (KURF) has been commissioned to perform initial screening of materials for radioactivity primarily from nuclides in the 238U and 232Th decay chains, 40K and cosmic-ray induced isotopes. The facility consists of two commercial low-background high purity germanium (HPGe) detectors. A continuum background reduction better than a factor of 10 was achieved by going underground. This paper describes the facility, detector systems, analysis techniques and selected assay results.Comment: 7 pages, 7 figures. Submitted to NIM