P2X receptor trafficking in neurons is subunit specific

P2X receptors within the CNS mediate excitatory synaptic transmission and also act presynaptically to modulate neurotransmitter release. We have studied the targeting and trafficking of P2X4 and P2X2 receptors heterologously expressed in cultured olfactory bulb neurons. Homomeric P2X4 receptors had a punctate distribution, and many of the puncta colocalized with early endosomes. In contrast, P2X2 receptors were primarily localized at the plasma membrane. By antibody-labeling of surface receptors in living neurons, we showed that P2X4 receptors undergo rapid constitutive internalization and subsequent reinsertion into the plasma membrane, whereas P2X2 receptors were not regulated in such a way. The internalization of P2X4 receptors was dynamin-dependent, and the binding of ATP enhanced the basal rate of retrieval in a Ca2+-independent manner. The presence of the P2X4 subunit in a P2X4/6 heteromer governed the trafficking properties of the receptor. P2X receptors acted presynaptically to enhance the release of glutamate, suggesting that the regulated cycling of P2X4-containing receptors might provide a mechanism for modulation of synaptic transmission

Crystal Structures of Polymerized Fullerides AC60, A=K, Rb, Cs and Alkali-mediated Interactions

Starting from a model of rigid interacting C60 polymer chains on an orthorhombic lattice, we study the mutual orientation of the chains and the stability of the crystalline structures Pmnn and I2/m. We take into account i) van der Waals interactions and electric quadrupole interactions between C60 monomers on different chains as well as ii) interactions of the monomers with the surrounding alkali atoms. The direct interactions i) always lead to an antiferrorotational structure Pmnn with alternate orientation of the C60 chains in planes (001). The interactions ii) with the alkalis consist of two parts: translation-rotation (TR) coupling where the orientations of the chains interact with displacements of the alkalis, and quadrupolar electronic polarizability (ep) coupling, where the electric quadrupoles on the C60 monomers interact with induced quadrupoles due to excited electronic d states of the alkalis. Both interactions ii) lead to an effective orientation-orientation interaction between the C60 chains and always favor the ferrorotational structure I2/m where C60 chains have a same orientation. The structures Pmnn for KC60 and I2/m for Rb- and CsC60 are the result of a competition between the direct interaction i) and the alkali-mediated interactions ii). In Rb- and CsC60 the latter are found to be dominant, the preponderant role being played by the quadrupolar electronic polarizability of the alkali ions.Comment: J.Chem.Phys., in press, 14 pages, 3 figures, 8 table

Patient and practitioner satisfaction with tele-dermatology including Australia’s indigenous population: A systematic review of the literature

AbstractBackgroundAustralia’s health disparity, combined with evolving technologies, has evoked increasing interest and funding in health services that could address inequities. One such emerging service is tele-medicine.ObjectiveThe purpose of this report is to discuss and evaluate the current literature regarding patient and practitioner satisfaction with tele-medicine, and more specifically tele-dermatology.MethodsWe searched for literature relevant to tele-dermatology use among Australia’s indigenous population. We synthesized the literature in our report and identified elements of tele-dermatology not yet researched.ResultsMost significantly, all available research is currently based on descriptive studies and there is no validated tool to assess the efficacy of tele-dermatology.LimitationsNo published research currently exists on the use of tele-dermatology among Australia’s indigenous population.ConclusionA review of the literature shows that tele-dermatology is considered a valuable service, particularly to patients living in rural areas who might not otherwise have access to specialist care

Swine Trichinella Infection and Geographic Information System Tools

Pastured pigs are vulnerable to Trichinella spiralis infection through exposure to wild reservoir hosts. To evaluate the potential impact of the expanding production of pork from pasture-raised pigs, we mapped locations of T. spiralis occurrence and pastured-pig farms in the United States. Twenty-eight farms were located within 50 km of previous infection

The effects of DAT1 genotype on fMRI activation in an emotional go/no-go task

Dopaminergic brain circuits participate in emotional processing and impulsivity. The dopamine transporter (DAT) modulates dopamine reuptake. A variable number tandem repeat (VNTR) in the dopamine transporter gene (DAT1) affects DAT expression. The influence of DAT1 genotype on neural activation during emotional processing and impulse inhibition has not been examined. Forty-two healthy subjects were classified as 9DAT (n = 17) or 10DAT (n = 25) based on DAT1 genotype (9DAT = 9R/9R and 9R/10R; 10DAT = 10R/10R). Subjects underwent fMRI during non-emotional and emotional go/no-go tasks. Subjects were instructed to inhibit responses to letters, happy faces, or sad faces in separate blocks. Accuracy and reaction time did not differ between groups. Within group results showed activation in regions previously implicated in emotional processing and response inhibition. Between groups results showed increased activation in 9DAT individuals during inhibition. During letter inhibition, 9DAT individuals exhibited greater activation in right inferior parietal regions. During sad inhibition, 9DAT Individuals exhibited greater activation in frontal, posterior cingulate, precuneus, right cerebellar, left paracentral, and right occipital brain regions. The interaction between DAT genotype and response type in sad versus letter stimuli showed increased activation in 9DAT individuals during sad no-go responses in the anterior cingulate cortex, extending into frontal-orbital regions. 9DAT individuals have greater activation than 10DAT individuals during neutral and sad inhibition, showing that genotypic variation influencing basal dopamine levels can alter the neural basis of emotional processing and response inhibition. This may indicate that 9R carriers exert more effort to overcome increased basal dopamine activation when inhibiting responses in emotional contexts

Character Strengths and Well-being: Differences in Social Activity among College Students

There has been an increase in students seeking counseling services in universities, with depression and anxiety being the most prevalent presenting concerns. Previous research indicates that the use of character strengths has been effective in reducing symptoms of depression and anxiety. Many of the interventions used to develop character strengths and improve well-being involve a social component, yet no research has investigated how social activity relates to the link between character strengths and well-being. In this study, relationships between the following variables were explored: character strengths (love, hope, curiosity, zest), subjective well-being, social activity, and social group participation. Social activity as a mediator of character strengths and well-being was also explored. Data were collected from 254 college-age students, ranging from 18 to 24 years of age (M = 20.60). One outlier was removed from the data, ending with 253 total participants, with 67% female (n=169) and 33% male (n=84). Descriptive statistics, frequency statistics, Pearson product-moment correlations, independent samples t-tests, and hierarchical multiple regression were used. Males endorsed higher levels of social activity (M = 24.67, SD = 4.93) than female participants (M = 23.07, SD = 4.01). Additionally, there were statistically significant differences in subjective well-being and endorsement of love scores, with females scoring higher than male participants. Consistent with previous research, results show a moderate positive correlation between subjective well-being and love (r(250) = .467, p < .01), hope (r(250) = .357, p < .01), curiosity (r(250) = .387, p < .01), zest (r(250) = .429, p < .01). Inconsistent with previous research, a significant relationship between social activity and well-being was not found. A positive significant relationship between social group participation and well-being was found r(250) = .197, p < .01 as well as between social group participation and love r(250) = .127, p < .05, curiosity r(250) = .159, p < .05, and zest r(250) = .184, p < .05. No significant relationship was found for hope. Results of the Sobel test suggest that mediation was not present. Implications of these findings as well as limitations and directions for future research are discussed.Educational Psycholog

Extended Huckel theory for bandstructure, chemistry, and transport. II. Silicon

In this second paper, we develop transferable semi-empirical parameters for the technologically important material, silicon, using Extended Huckel Theory (EHT) to calculate its electronic structure. The EHT-parameters areoptimized to experimental target values of the band dispersion of bulk-silicon. We obtain a very good quantitative match to the bandstructure characteristics such as bandedges and effective masses, which are competitive with the values obtained within an $sp^3 d^5 s^*$ orthogonal-tight binding model for silicon. The transferability of the parameters is investigated applying them to different physical and chemical environments by calculating the bandstructure of two reconstructed surfaces with different orientations: Si(100) (2x1) and Si(111) (2x1). The reproduced $\pi$- and $\pi^*$-surface bands agree in part quantitatively with DFT-GW calculations and PES/IPES experiments demonstrating their robustness to environmental changes. We further apply the silicon parameters to describe the 1D band dispersion of a unrelaxed rectangular silicon nanowire (SiNW) and demonstrate the EHT-approach of surface passivation using hydrogen. Our EHT-parameters thus provide a quantitative model of bulk-silicon and silicon-based materials such as contacts and surfaces, which are essential ingredients towards a quantitative quantum transport simulation through silicon-based heterostructures.Comment: 9 pages, 9 figure