The T2K ND280 Off-Axis Pi-Zero Detector

The Pi-Zero detector (P{\O}D) is one of the subdetectors that makes up the off-axis near detector for the Tokai-to-Kamioka (T2K) long baseline neutrino experiment. The primary goal for the P{\O}D is to measure the relevant cross sections for neutrino interactions that generate pi-zero's, especially the cross section for neutral current pi-zero interactions, which are one of the dominant sources of background to the electron neutrino appearance signal in T2K. The P{\O}D is composed of layers of plastic scintillator alternating with water bags and brass sheets or lead sheets and is one of the first detectors to use Multi-Pixel Photon Counters (MPPCs) on a large scale.Comment: 17 pages, submitted to NIM

Interrogating trans and sexual identities through the conceptual lens of translocational positionality

This article explores the confluence of trans identity and sexuality drawing on the concept of translocational positionality. In this discussion, a broad spectrum of gendered positionalities incorporates trans identity which, in turn, acknowledges normative male and female identities as well as non-binary ones. It is also recognised, however, that trans identity overlaps with other positionalities (pertaining to sexuality, for example) to shape social location. In seeking to understand subject positions, a translocational lens acknowledges the contextuality and temporality of social categories to offer an analysis which recognises the overlaps and differentials of co-existing positionalities. This approach enables an analysis which explores how macro, or structural, contexts shape agency (at the micro-level) and also how both are mediated by trans people's multiple and shifting positionalities. In this framing, positionality represents a meso layer between structure and agency. Four case studies are presented using data from a qualitative study which explored trans people's experiences of family, intimacy and domestic abuse. We offer an original contribution to the emerging knowledge-base on trans sexuality by presenting data from four case studies. We do so whilst innovatively applying the conceptual lens of translocational positionality to an analysis which considers macro, meso and micro levels of influence

How important is the context of an adolescent's first alcoholic drink? Evidence that parental provision may reduce later heavy episodic drinking

Objective: This study examined the extent to which a retrospective measure of parental provision of the first alcoholic beverage was related to current heavy episodic drinking and current responsible drinking practices. Sample: 608 14- to 17-year-olds from the 2007 Australian National Drug Strategy Household Survey. Measures: Source of first alcoholic beverage (friends/parents/others), source of current alcohol, age of onset of alcohol use, current responsible drinking practices, and proportion of current friends who drink. Results: Binary logistic and multiple regression procedures revealed that parental provision of an adolescent's first alcoholic beverage predicted lower current heavy episodic drinking, and responsible drinking mediated this association. Discussion: The results suggested that for adolescents who become alcohol users, parental provision of the first drink may reduce subsequent alcohol-related risks compared to introduction to alcohol by friends and other sources. Alcohol-related risks remain significant for adolescents who consume alcohol, independent of who is the provider. Copyright (C) 2012 S. Karger AG, Base

Magnetic Reconnection in Extreme Astrophysical Environments

Magnetic reconnection is a basic plasma process of dramatic rearrangement of magnetic topology, often leading to a violent release of magnetic energy. It is important in magnetic fusion and in space and solar physics --- areas that have so far provided the context for most of reconnection research. Importantly, these environments consist just of electrons and ions and the dissipated energy always stays with the plasma. In contrast, in this paper I introduce a new direction of research, motivated by several important problems in high-energy astrophysics --- reconnection in high energy density (HED) radiative plasmas, where radiation pressure and radiative cooling become dominant factors in the pressure and energy balance. I identify the key processes distinguishing HED reconnection: special-relativistic effects; radiative effects (radiative cooling, radiation pressure, and Compton resistivity); and, at the most extreme end, QED effects, including pair creation. I then discuss the main astrophysical applications --- situations with magnetar-strength fields (exceeding the quantum critical field of about 4 x 10^13 G): giant SGR flares and magnetically-powered central engines and jets of GRBs. Here, magnetic energy density is so high that its dissipation heats the plasma to MeV temperatures. Electron-positron pairs are then copiously produced, making the reconnection layer highly collisional and dressing it in a thick pair coat that traps radiation. The pressure is dominated by radiation and pairs. Yet, radiation diffusion across the layer may be faster than the global Alfv\'en transit time; then, radiative cooling governs the thermodynamics and reconnection becomes a radiative transfer problem, greatly affected by the ultra-strong magnetic field. This overall picture is very different from our traditional picture of reconnection and thus represents a new frontier in reconnection research.Comment: Accepted to Space Science Reviews (special issue on magnetic reconnection). Article is based on an invited review talk at the Yosemite-2010 Workshop on Magnetic Reconnection (Yosemite NP, CA, USA; February 8-12, 2010). 30 pages, no figure

Girls and Boys Born before 28 Weeks Gestation: Risks of Cognitive, Behavioral, and Neurologic Outcomes at Age 10 Years

To compare the prevalence of cognitive, neurological, and behavioral outcomes at 10 years of age in 428 girls and 446 boys who were born extremely preterm (EP)

The Relationship of Maternal Prepregnancy Body Mass Index and Pregnancy Weight Gain to Neurocognitive Function at Age 10 Years among Children Born Extremely Preterm

OBJECTIVE: To assess the association between maternal prepregnancy body mass index and adequacy of pregnancy weight gain in relation to neurocognitive function in school-aged children born extremely preterm. STUDY DESIGN: Study participants were 535 ten-year-old children enrolled previously in the prospective multicenter Extremely Low Gestational Age Newborns cohort study who were products of singleton pregnancies. Soon after delivery, mothers provided information about prepregnancy weight. Prepregnancy body mass index and adequacy of weight gain were characterized based on this information. Children underwent a neurocognitive evaluation at 10 years of age. RESULTS: Maternal prepregnancy obesity was associated with increased odds of a lower score for Differential Ability Scales-II Verbal IQ, for Developmental Neuropsychological Assessment-II measures of processing speed and visual fine motor control, and for Wechsler Individual Achievement Test-III Spelling. Children born to mothers who gained an excessive amount of weight were at increased odds of a low score on the Oral and Written Language Scales Oral Expression assessment. Conversely, children whose mother did not gain an adequate amount of weight were at increased odds of a lower score on the Oral and Written Language Scales Oral Expression and Wechsler Individual Achievement Test-III Word Reading assessments. CONCLUSION: In this cohort of infants born extremely preterm, maternal obesity was associated with poorer performance on some assessments of neurocognitive function. Our findings are consistent with the observational and experimental literature and suggest that opportunities may exist to mitigate risk through education and behavioral intervention before pregnancy

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

[no abstract available

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b

We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society