Kryzys w konstytucjonalizmie współczesnym

Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201

Talking Politics on Facebook: Network Centrality and Political Discussion Practices in Social Media

This study examines the relationship between political discussion on Facebook and social network location. It uses a survey name generator to map friendship ties between students at a university and to calculate their centralities in that network. Social connectedness in the university network positively predicts more frequent political discussion on Facebook. But in political discussions, better connected individuals do not capitalize equally on the potential influence that stems from their more central network locations. Popular individuals who have more direct connections to other network members discuss politics more often but in politically safer interactions that minimize social risk, preferring more engaged discussion with like-minded others and editing their privacy settings to guard their political disclosures. Gatekeepers who facilitate connections between more pairs of otherwise disconnected network members also discuss politics more frequently, but are more likely to engage in risk-tolerant discussion practices such as posting political updates or attempting political persuasion. These novel findings on social connectedness extend research on offline political discussion into the social media sphere, and suggest that as social network research proliferates, analysts should consider how various types of network location shape political behavior

Networks of Mobilization: Student Involvement in a Municipal Election

An enduring issue in the study of political participation is the extent to which political awareness and engagement are socially or individually motivated. We address these issues in the context of a municipal election which generated a high level of political engagement on the part of college students for whom the election was relevant. An effort was made to interview all these students using an on-line survey, and the students were asked to provide information on their friendship networks. The paper demonstrates that awareness and engagement are not simply a consequence of individually defined interests and awareness, but rather that individuals are informed and engaged based on their locations within structured networks of social interaction

NMR investigations of interactions between anesthetics and lipid bilayers

Interactions between anesthetics (lidocaine and short chain alcohols) and lipid membranes formed by dimyristoylphosphatidylcholine (DMPC) were studied using NMR spectroscopy. The orientational order of lidocaine was investigated using deuterium NMR on a selectively labelled compound whereas segmental ordering in the lipids was probed by two-dimensional 1H-13C separated local field experiments under magic-angle spinning conditions. In addition, trajectories generated in molecular dynamics (MD) computer simulations were used for interpretation of the experimental results. Separate simulations were carried out with charged and uncharged lidocaine molecules. Reasonable agreement between experimental dipolar interactions and the calculated counterparts was observed. Our results clearly show that charged lidocaine affects significantly the lipid headgroup. In particular the ordering of the lipids is increased accompanied by drastic changes in the orientation of the P-N vector in the choline group

Mesocorticolimbic monoamine correlates of methamphetamine sensitization and motivation.

Methamphetamine (MA) is a highly addictive psychomotor stimulant, with life-time prevalence rates of abuse ranging from 5-10% world-wide. Yet, a paucity of research exists regarding MA addiction vulnerability/resiliency and neurobiological mediators of the transition to addiction that might occur upon repeated low-dose MA exposure, more characteristic of early drug use. As stimulant-elicited neuroplasticity within dopamine neurons innervating the nucleus accumbens (NAC) and prefrontal cortex (PFC) is theorized as central for addiction-related behavioral anomalies, we used a multi-disciplinary research approach in mice to examine the interactions between sub-toxic MA dosing, motivation for MA and mesocorticolimbic monoamines. Biochemical studies of C57BL/6J (B6) mice revealed short- (1 day), as well as longer-term (21 days), changes in extracellular dopamine, DAT and/or D2 receptors during withdrawal from 10, once daily, 2 mg/kg MA injections. Follow-up biochemical studies conducted in mice selectively bred for high vs. low MA drinking (respectively, MAHDR vs. MALDR mice), provided novel support for anomalies in mesocorticolimbic dopamine as a correlate of genetic vulnerability to high MA intake. Finally, neuropharmacological targeting of NAC dopamine in MA-treated B6 mice demonstrated a bi-directional regulation of MA-induced place-conditioning. These results extend extant literature for MA neurotoxicity by demonstrating that even subchronic exposure to relatively low MA doses are sufficient to elicit relatively long-lasting changes in mesocorticolimbic dopamine and that drug-induced or idiopathic anomalies in mesocorticolimbic dopamine may underpin vulnerability/resiliency to MA addiction

Ankieta w sprawie rewizji Konstytucji polskiej

Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201