219 research outputs found
Does attentional style moderate the relationship between time perspective and social network addiction? A crossâsectional study on a sample of social networking sites users
The present study investigates the role of attentional style as a moderator variable between temporal perspective and social network addiction, since little is known about usersâ cognitive variables involved in this kind of addictive behavior. To achieve this goal, a sample of 186 volunteers and anonymous social networking sites users (M = 34%; F = 66%; Mage = 22.54 years; SD = 3.94; range: 18 Ă· 45 years) participated in a crossâsectional study. All participants filled out self-report instruments measuring temporal perspective, internal vs. external attentional style, and social network addiction. The results align with the previous literature and show that present fatalistic and past negative time orientations are associated with social network addiction, whereas the future is a negative precursor. Moreover, a fourâstep hierarchical regression analysis showed that internal attentional style is a significant moderator of the relationship between high levels of temporal perspective and a high level of social network addiction. This result suggests that social networkâaddicted users are oriented toward internal stimuli such as their intrusive thoughts or feelings and that social network addiction is similar to obsessive compulsive disorders, depression, or anxiety. Despite its limitations, the present study could contribute to the efforts of clinicians, psychiatrists, psychologists, teachers, and all those who seek to combat social network addiction in developing treatment programs to reduce its harmful effects
Alcohol Use and Periodic Limb Movements of Sleep
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65771/1/j.1530-0277.1993.tb00747.x.pd
Construction and First Validation of a French Scale of Environmental Harassment at Work (EHWS)
Harassment is a form of violence that is increasingly reported in the world of work and has given rise to numerous studies. This article presents the results of a series of five studies to construct and validate the French Environmental Harassment at Work Scale-EHWS. Four hundred and four people employed in various professional sectors (health, education or services) participated in the five studies. A questionnaire of Environmental Harassment at Work was constructed (Study 1). Study 2 revealed a four-dimensional factor structure, which was confirmed by confirmatory factor analysis (Study 3). The questionnaire was shown to have good reliability (Study 4) and convergent validity (Study 5). The EHWS could be a valuable tool for human resource managers to assess environmental harassment in the organisation, and also for occupational health and safety organisations to highlight the nature of environmental harassment, how it can be reported and prevente
Structure and mechanism of human DNA polymerase η
The variant form of the human syndrome xeroderma pigmentosum (XPV) is caused by a deficiency in DNA polymerase eta (Pol eta), a DNA polymerase that enables replication through ultraviolet-induced pyrimidine dimers. Here we report high-resolution crystal structures of human Pol eta at four consecutive steps during DNA synthesis through cis-syn cyclobutane thymine dimers. Pol eta acts like a 'molecular splint' to stabilize damaged DNA in a normal B-form conformation. An enlarged active site accommodates the thymine dimer with excellent stereochemistry for two-metal ion catalysis. Two residues conserved among Pol eta orthologues form specific hydrogen bonds with the lesion and the incoming nucleotide to assist translesion synthesis. On the basis of the structures, eight Pol eta missense mutations causing XPV can be rationalized as undermining the molecular splint or perturbing the active-site alignment. The structures also provide an insight into the role of Pol eta in replicating through D loop and DNA fragile sites
1,4-Disubstituted-[1,2,3]triazolyl-Containing Analogues of MT-II: Design, Synthesis, Conformational Analysis, and Biological Activity
Side chain-to-side chain cyclizations represent a strategy to select a family of bioactive conformations by reducing the entropy and enhancing the stabilization of functional ligand-induced receptor conformations. This structural manipulation contributes to increased target specificity, enhanced biological potency, improved pharmacokinetic properties, increased functional potency, and lowered metabolic susceptibility. The CuI-catalyzed azideâalkyne 1,3-dipolar Huisgenâs cycloaddition, the prototypic click reaction, presents a promising opportunity to develop a new paradigm for an orthogonal bioorganic and intramolecular side chain-to-side chain cyclization. In fact, the proteolytic stable 1,4- or 4,1-disubstituted [1,2,3]triazolyl moiety is isosteric with the peptide bond and can function as a surrogate of the classical side chain-to-side chain lactam forming bridge. Herein we report the design, synthesis, conformational analysis, and functional biological activity of a series of i-to-i+5 1,4- and 4,1-disubstituted [1,2,3]triazole-bridged cyclopeptides derived from MT-II, the homodetic Asp5 to Lys10 side chain-to-side chain bridged heptapeptide, an extensively studied agonist of melanocortin receptors
Sleep-Disordered Breathing in Alcoholics
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66229/1/j.1530-0277.1999.tb04034.x.pd
Kissing G Domains of MnmE Monitored by X-Ray Crystallography and Pulse Electron Paramagnetic Resonance Spectroscopy
The authors of this research article demonstrate the nature of the conformational changes MnmE was previously suggested to undergo during its GTPase cycle, and show the nucleotide-dependent dynamic movements of the G domains around two swivel positions relative to the rest of the protein. These movements are of crucial importance for understanding the mechanistic principles of this GAD
P-hydroxyphenylpyruvate, an intermediate of the Phe/Tyr catabolism, improves mitochondrial oxidative metabolism under stressing conditions and prolongs survival in rats subjected to profound hemorrhagic shock
The aim of this study was to test the effect of a small volume administration of p-hydroxyphenylpyruvate (pHPP) in a rat model of profound hemorrhagic shock and to assess a possible metabolic mechanism of action of the compound. The results obtained show that hemorrhaged rats treated with 2-4% of the estimated blood volume of pHPP survived significantly longer (p<0.001) than rats treated with vehicle. In vitro analysis on cultured EA.hy 926 cells demonstrated that pHPP improved cell growth rate and promoted cell survival under stressing conditions. Moreover, pHPP stimulated mitochondria-related respiration under ATP-synthesizing conditions and exhibited antioxidant activity toward mitochondria-generated reactive oxygen species. The compound effects reported in the in vitro and in vivo analyses were obtained in the same millimolar concentration range. These data disclose pHPP as an efficient energetic substrates-supplier to the mitochondrial respiratory chain as well as an antioxidant supporting the view that the compound warrants further evaluation as a therapeutic agent. © 2014 Cotoia et al
Sleep-Disordered Breathing in Alcoholics: Association with Age
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66156/1/j.1530-0277.1993.tb05224.x.pd
A 2-week, polysomnographic, safety study of sodium oxybate in obstructive sleep apnea syndrome
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