Social Factors in Prescription Stimulant Abuse Among College Students

In an attempt to maximize their academic performance, many American college students turn toward such prescription stimulant drugs as Adderall and Ritalin, which can increase users\u27 attention span and ability to focus, but are not without risks, including such aversive side effects as anxiety, migraines, and obsessive-compulsive behavior. Prevalence rates for prescription stimulant abuse (PSA) by college students vary widely, with rates as high as 50.6% (McCabe, West, Teter, & Boyd, 2014). PSA among college students is most commonly endorsed for perceived academic benefits, but many students report engaging in recreational PSA, often to resist the depressant effects of alcohol and remain alert and sociable at parties. The current study was designed to examine the social factors influencing students\u27 abuse of prescription stimulants, and to identify differences in these factors between academic and recreational users. A survey of 175 undergraduate students was used to investigate the influence of parental expectations, academic support, resistance to peer influence, alcohol and cannabis use, and fraternity/sorority membership on PSA and purpose of PSA (academic or recreational). Results of independent-samples t-tests and chi-square analyses indicated that users drank more alcohol, obtained lower resistance to peer influence scores, were more likely to be male, more likely to be in a fraternity or sorority, and more likely to have used cannabis in the past year than nonusers. Academic users also had higher scores on parental expectations and resistance to peer influence than recreational users. The results extend previous findings by highlighting differences between academic and recreational users of prescription stimulants. These findings may be useful in identifying populations of college students who are at-risk for different variations of prescription stimulant abuse

Microstructure and hard magnetic properties in bulk rods of Nd 60Fe 30Al 10 glass forming alloys

The Nd60Fe30Al10 alloy exhibits a large glass forming ability which allows to obtain relatively thick cast rods containing large volume fractions of amorphous phases. In this work the microstructure and the hard magnetic properties of as-cast rods are characterized. The alloy is processed by suction casting into a chilled copper mould to obtain cylinders 5 mm diameter and 50 mm length. This diameter is selected because it is an upper limit for this processing route, beyond which the hard properties largely deteriorate. A room temperature coercivity of 0.34 T is obtained. The sample microstructure is heterogeneous, with very different size scales near the surface and along the central zone. However, in both regions a large fraction of an amorphous ferromagnetic phase is observed; it is found that paramagnetic nanocrystalline phases, mainly Nd or Nd-rich particles embedded in the amorphous matrix, are somewhat coarser in the central zone. These larger nanocrystals, less efficient to pin domain walls, are proposed to be responsible for the lower coercive fields observed, as compared with those found in cylinders 1 to 3 mm diameter where no inhomogeneities are found. This conclusion is supported by microstructure, calorimetric and magnetic observations.Fil: Levingston, J. M.. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Valente, R.. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Ghilarducci, Ada Albertina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Fabietti, Luis Maria Rodolfo. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física. Sección Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Salva, Horacio Ramon. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Urreta, S. E.. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

A remark on the excess of Hadamard matrices and orthogonal designs

Some improved upper and lower bounds are given for the excess of Hadamard matrices. The excess of orthogonal designs is defined and discussed

Molecular Determinants of Arenavirus Z Protein Homo-Oligomerization and L Polymerase Binding▿

The arenavirus Z is a zinc-binding RING protein that has been implicated in multiple functions during the viral life cycle. These roles of Z involve interactions with viral and cellular proteins that remain incompletely understood. In this regard, Z inhibits viral RNA transcription and replication through direct interaction with the viral L polymerase. Here, we defined the L-binding domain of Tacaribe virus (TCRV) Z protein and the structural requirements mediating Z homo-oligomerization. By using site-directed mutagenesis, coimmunoprecipitation, and functional assays, we showed that residues R37, N39, W44, L50, and Y57, located around the zinc coordination site I, play a critical role in the Z-L interaction. We also found that Z protein from either TCRV or the pathogenic Junin virus (JUNV) self-associates into oligomeric forms in mammalian cells. Importantly, mutation of the myristoylation site, the strictly conserved residue G at position 2, severely impaired the ability of both TCRV Z and JUNV Z to self-interact as well as their capacity to accumulate at the plasma membrane, strongly suggesting that Z homo-oligomerization is associated with its myristoylation and cell membrane targeting. In contrast, disruption of the RING structure or substitution of W44 or N39, which are critical for L protein recognition, did not affect Z self-binding. Overall, the data presented here indicate that homo-oligomerization is not a requirement for Z-L interaction or Z-mediated polymerase activity inhibition