Snowflakes Song : Also Christmas Chimes : A Christmas Song

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An Examination of Prepartying and Drinking Game Playing During High School and Their Impact on Alcohol-Related Risk Upon Entrance into College

Prepartying and drinking game playing are associated with excessive alcohol consumption and alcohol-related negative consequences in college populations; however, research exploring the prevalence of these high risk drinking contexts among high school students, and how such engagement may impact both high school and subsequent college drinking risk, is lacking. The current study, which is the first study to assess prepartying during high school, examined how engaging in either prepartying or drinking game playing during high school was associated with risky high school drinking as well asalcohol use and consequences during the transitional first month of college. The study involved 477 first-year college students, the majority of whom were 18 years old (94%), female (66%), and Caucasian (59%). Prepartying was found to be highly prevalent in high school (45%). Further, students who prepartied or played drinking games during high school drank significantly more in high school than students who did not engage in these high risk activities. Finally, prepartying and game playing during high school were associated with greater collegiate alcohol consumption (controlling for high school drinking) and consequences (controlling for both high school and college drinking). This study establishes prepartying and drinking games as common high risk activities among both high school and incoming first-year college students, and addresses implications for prevention and targeted interventions

Optimal Packings of Superballs

Dense hard-particle packings are intimately related to the structure of low-temperature phases of matter and are useful models of heterogeneous materials and granular media. Most studies of the densest packings in three dimensions have considered spherical shapes, and it is only more recently that nonspherical shapes (e.g., ellipsoids) have been investigated. Superballs (whose shapes are defined by |x1|^2p + |x2|^2p + |x3|^2p <= 1) provide a versatile family of convex particles (p >= 0.5) with both cubic- and octahedral-like shapes as well as concave particles (0 < p < 0.5) with octahedral-like shapes. In this paper, we provide analytical constructions for the densest known superball packings for all convex and concave cases. The candidate maximally dense packings are certain families of Bravais lattice packings. The maximal packing density as a function of p is nonanalytic at the sphere-point (p = 1) and increases dramatically as p moves away from unity. The packing characteristics determined by the broken rotational symmetry of superballs are similar to but richer than their two-dimensional "superdisk" counterparts, and are distinctly different from that of ellipsoid packings. Our candidate optimal superball packings provide a starting point to quantify the equilibrium phase behavior of superball systems, which should deepen our understanding of the statistical thermodynamics of nonspherical-particle systems.Comment: 28 pages, 16 figure

Differential Drinking Patterns of Family History Positive and Family History Negative First Semester College Females

Objective This study compares the natural drinking patterns of family history positive and family history negative women during their first semester of college, a transitional period known to coincide with considerable alcohol-related risks. Method Seventy-two incoming undergraduate females, approximately half of whom reported a family history of alcohol misuse, completed initial questionnaires as well as Timeline Followback assessments. In addition, participants completed five successive weeks of online behavioral diaries measuring three categories of prospective alcohol consumption: total drinks, maximum drinks, and heavy episodic drinking events. Repeated measures ANCOVA models, controlling for prior alcohol consumption, examined participants’ drinking behavior. Results Over the course of the five assessed weeks, first semester females with a genetic predisposition to alcohol problems were found to consume significantly more total drinks (p \u3c .05), maximum drinks (p \u3c .05), and were more likely to drink heavily (p \u3c .05) than family history negative peers. Conclusions Findings highlight increased alcohol-related risks faced by incoming first-year college females with a reported family history of problematic drinking and, thus, emphasize the need for early interventions targeted toward this at-risk group

Systematic performance of the ASKAP Fast Radio Burst search algorithm

Detecting fast radio bursts (FRBs) requires software pipelines to search for dispersed single pulses of emission in radio telescope data. In order to enable an unbiased estimation of the underlying FRB population, it is important to understand the algorithm efficiency with respect to the search parameter space and thus the survey completeness. The Fast Real-time Engine for Dedispersing Amplitudes (FREDDA) search pipeline is a single pulse detection pipeline designed to identify radio pulses over a large range of dispersion measures (DM) with low latency. It is used on the Australian Square Kilometre Array Pathfinder (ASKAP) for the Commensal Real-time ASKAP Fast Transients (CRAFT) project . We utilise simulated single pulses in the low- and high-frequency observation bands of ASKAP to analyse the performance of the pipeline and infer the underlying FRB population. The simulation explores the Signal-to-Noise Ratio (S/N) recovery as a function of DM and the temporal duration of FRB pulses in comparison to injected values. The effects of intra-channel broadening caused by dispersion are also carefully studied in this work using control datasets. Our results show that for Gaussian-like single pulses, $> 85 \%$ of the injected signal is recovered by pipelines such as FREDDA at DM < 3000 $\mathrm{pc\ cm^{-3}}$ using standard boxcar filters compared to an ideal incoherent dedispersion match filter. Further calculations with sensitivity implies at least $\sim 10\%$ of FRBs in a Euclidean universe at target sensitivity will be missed by FREDDA and HEIMDALL, another common pipeline, in ideal radio environments at 1.1 GHz.Comment: 11 pages 13 figures. Accepted for MNRAS; Data and simulation code available onlin

Quantum information cannot be completely hidden in correlations: implications for the black-hole information paradox

The black-hole information paradox has fueled a fascinating effort to reconcile the predictions of general relativity and those of quantum mechanics. Gravitational considerations teach us that black holes must trap everything that falls into them. Quantum mechanically the mass of a black hole leaks away as featureless (Hawking) radiation, but if the black hole vanishes, where is the information about the matter that made it? We treat the states of the in-fallen matter quantum mechanically and show that the black-hole information paradox becomes more severe. Our formulation of the paradox rules out one of the most conservative resolutions: that the state of the in-falling matter might be hidden in correlations between semi-classical Hawking radiation and the internal states of the black hole. As a consequence, either unitarity or Hawking's semi-classical predictions must break down. Any resolution of the black-hole information crisis must elucidate one of these possibilities.Comment: We first obtained this result two years ag

Development and Validation of the Hookup Motives Questionnaire (HMQ)

Despite the high prevalence rates and growing research on hooking up among college students, no multidimensional inventory exists in the literature to assess motivations for hooking up. In the current study, we report on the development and validation of the Hookup Motives Questionnaire (HMQ), designed to assess the various reasons for hooking up. Exploratory and confirmatory factor analyses were conducted using 2 samples of college students (Campus 1, N = 401; Campus 2, N = 367). Exploratory factor analysis was undertaken to explore the psychometric properties of an initial set of 25 items, and confirmatory factor analysis was conducted to evaluate additional properties of the factor structure. The final factor structure of the HMQ contained 19 items that tapped 5 subscales representing social-sexual, social-relationship, enhancement, coping, and conformity motives. Results demonstrated good internal consistency and discriminant validity for the subscales. Moreover, criterion-related validity was satisfied by showing that HMQ subscales significantly correlated with hookup approval and behavior. Gender differences on the measures were found. The inventory offers considerable potential as a psychometrically sound instrument that may be administered to understand reasons for engaging in potentially risky hookup behaviors and used to inform the design of sexual health programs and interventions targeting young adults

Novel Features Arising in the Maximally Random Jammed Packings of Superballs

Dense random packings of hard particles are useful models of granular media and are closely related to the structure of nonequilibrium low-temperature amorphous phases of matter. Most work has been done for random jammed packings of spheres, and it is only recently that corresponding packings of nonspherical particles (e.g., ellipsoids) have received attention. Here we report a study of the maximally random jammed (MRJ) packings of binary superdisks and monodispersed superballs whose shapes are defined by |x_1|^2p+...+|x_2|^2p<=1 with d = 2 and 3, respectively, where p is the deformation parameter with values in the interval (0, infinity). We find that the MRJ densities of such packings increase dramatically and nonanalytically as one moves away from the circular-disk and sphere point. Moreover, the disordered packings are hypostatic and the local arrangements of particles are necessarily nontrivially correlated to achieve jamming. We term such correlated structures "nongeneric". The degree of "nongenericity" of the packings is quantitatively characterized by determining the fraction of local coordination structures in which the central particles have fewer contacting neighbors than average. We also show that such seemingly special packing configurations are counterintuitively not rare. As the anisotropy of the particles increases, the fraction of rattlers decreases while the minimal orientational order increases. These novel characteristics result from the unique rotational symmetry breaking manner of the particles.Comment: 20 pages, 8 figure

Evolution of spin-wave excitations in ferromagnetic metallic manganites

Neutron scattering results are presented for spin-wave excitations of three ferromagnetic metallic $A_{1-x}A^{\prime}_{x}$MnO$_3$ manganites (where $A$ and $A^\prime$ are rare- and alkaline-earth ions), which when combined with previous work elucidate systematics of the interactions as a function of carrier concentration $x$, on-site disorder, and strength of the lattice distortion. The long wavelength spin dynamics show only a very weak dependence across the series. The ratio of fourth to first neighbor exchange ($J_4/J_1$) that controls the zone boundary magnon softening changes systematically with $x$, but does not depend on the other parameters. None of the prevailing models can account for these behaviors.Comment: Submitted to Phys. Rev. Let

Deconvolution with correct sampling

A new method for improving the resolution of astronomical images is presented. It is based on the principle that sampled data cannot be fully deconvolved without violating the sampling theorem. Thus, the sampled image should not be deconvolved by the total Point Spread Function, but by a narrower function chosen so that the resolution of the deconvolved image is compatible with the adopted sampling. Our deconvolution method gives results which are, in at least some cases, superior to those of other commonly used techniques: in particular, it does not produce ringing around point sources superimposed on a smooth background. Moreover, it allows to perform accurate astrometry and photometry of crowded fields. These improvements are a consequence of both the correct treatment of sampling and the recognition that the most probable astronomical image is not a flat one. The method is also well adapted to the optimal combination of different images of the same object, as can be obtained, e.g., from infrared observations or via adaptive optics techniques.Comment: 22 pages, LaTex file + 10 color jpg and postscript figures. To be published in ApJ, Vol 484 (1997 Feb.