Lack of influence of GTP cyclohydrolase gene (GCH1) variations on pain sensitivity in humans

OBJECTIVES: To assess the effect of variations in GTP cyclohydrolase gene (GCH1) on pain sensitivity in humans. METHODS: Thermal and cold pain sensitivity were evaluated in a cohort of 735 healthy volunteers. Among this cohort, the clinical pain responses of 221 subjects after the surgical removal of impacted third molars were evaluated. Genotyping was done for 38 single nucleotide polymorphisms (SNPs) whose heterozygosity > 0.2 in GCH1. Influence of the genetic variations including SNPs and haplotypes on pain sensitivity were analyzed. RESULTS: Minor allele frequencies and linkage disequilibrium show significant differences in European Americans, African Americans, Hispanic Americans and Asian Americans. Association analyses in European Americans do not replicate the previously reported important influence of GCH1 variations on pain sensitivity. CONCLUSION: Considering population stratification, previously reported associations between GCH1 genetic variations and pain sensitivity appear weak or negligible in this well characterized model of pain

Genetic polymorphisms in monoamine neurotransmitter systems show only weak association with acute post-surgical pain in humans

BACKGROUND: Candidate gene studies on the basis of biological hypotheses have been a practical approach to identify relevant genetic variation in complex traits. Based on previous reports and the roles in pain pathways, we have examined the effects of variations of loci in the genes of monoamine neurotransmitter systems including metabolizing enzymes, receptors and transporters on acute clinical pain responses in humans. RESULTS: Variations in the catecholamine metabolizing enzyme genes (MAOA and COMT) showed significant associations with the maximum post-operative pain rating while the serotonin transporter gene (SLC6A4) showed association with the onset time of post-operative pain. Analgesic onset time after medication was significantly associated with the norepinephrine transporter gene (SLC6A2). However, the association between COMT genetic variation and pain sensitivity in our study differ from previous studies with small sample sizes, population stratification and pain phenotype derived from combining different types of pain stimuli. Correcting for multiple comparisons did not sustain these genetic associations between monoamine neurotransmitter systems and pain sensitivity even in this large and homogeneous sample. CONCLUSION: These results suggest that the previously reported associations between genetic polymorphisms in the monoamine neurotransmitter systems and the interindividual variability in pain responses cannot be replicated in a clinically relevant pain phenotype

Drip Too Hard? Commercial Rap Music and Perceived Masculinity Ideals and Actual Self-Evaluations among Black U.S. and Dutch Adolescent Men.

Popular American commercial rap is believed to (re)produce cultural narratives of masculinity. Yet, there is no knowledge about the relationship between consumption of idealized masculinity in rap and young (Black) men’s senses of masculine selves. This study aims to explore how sixteen American and Dutch Black adolescent men perceive ideals of masculine behavior, physical appearance, and mate desirability in commercial rap. Grounded in social comparison theory, it furthermore aims to understand whether these young men compare themselves to these ideals, and if so, how this informs their self-evaluations. A (hybrid) comparative thematic analysis of interviews with eight U.S. and eight Dutch adolescents revealed three masculinity ideals to be present in rap and congruent with the majority of the respondents’ own ideals. First, it is appropriate for young men to be ‘playas’ and view (young) women as either (sexually) freaky girls or wifey material. Second, attractive men look wealthy, and, third, desirable men financially provide for their partners. The participants who endorsed these ideals and, subsequently, compared themselves to them, reported positive self-evaluations and emotions, which were believed to translate into their own behavior, appearance, and desirability. Interestingly, although the participants came from different cultural contexts, systematic differences in perception, attitude, social comparison and self-evaluation were not found. Suggestions for future research are provided and implications for intervention programs are discussed

Magneto-Optical Thin Films for On-Chip Monolithic Integration of Non-Reciprocal Photonic Devices

Achieving monolithic integration of nonreciprocal photonic devices on semiconductor substrates has been long sought by the photonics research society. One way to achieve this goal is to deposit high quality magneto-optical oxide thin films on a semiconductor substrate. In this paper, we review our recent research activity on magneto-optical oxide thin films toward the goal of monolithic integration of nonreciprocal photonic devices on silicon. We demonstrate high Faraday rotation at telecommunication wavelengths in several novel magnetooptical oxide thin films including Co substituted CeO2−δ, Co- or Fe-substituted SrTiO3−δ, as well as polycrystalline garnets on silicon. Figures of merit of 3~4 deg/dB and 21 deg/dB are achieved in epitaxial Sr(Ti0.2Ga0.4Fe0.4)O3−δ and polycrystalline (CeY2)Fe5O12 films, respectively. We also demonstrate an optical isolator on silicon, based on a racetrack resonator using polycrystalline (CeY2)Fe5O12/silicon strip-loaded waveguides. Our work demonstrates that physical vapor deposited magneto-optical oxide thin films on silicon can achieve high Faraday rotation, low optical loss and high magneto-optical figure of merit, therefore enabling novel high-performance non-reciprocal photonic devices monolithically integrated on semiconductor substrates.National Science Foundation (U.S.). Division of Materials Research (Grant No. DMR 0604430)National Science Foundation (U.S.). Division of Materials Research (Grant No. 1231392, Electronic, Photonic, and Magnetic Devices Program

Chip-scale photonics with plasmonic components

In this talk we will describe recent opportunities presented by plasmonics for chip-scale integration of photonic and electronic devices, including i)design of metal-insulator-metal plasmon waveguides that optimize the trade-off between mode localization and propagation loss in the visible and near-infrared ii) on-chip Si CMOS compatible light near-infrared light sources for coupling into plasmonic networks iii) plasmon-enhanced emission from quantum dots, and iv) opportunities for active plasmonic devices based on electro-optic and all-optical modulation of plasmon propagation

Physical Activity Levels among Preschool-Aged Children in Family Child Care Homes: A Comparison between Hispanic and Non-Hispanic Children Using Accelerometry

Obesity prevalence among Hispanic children is twice that of non-Hispanic white children; Hispanic children may also engage in less physical activity (PA) compared to non-Hispanic white children. A large number of U.S. preschool-aged children are cared for in Family Child Care Homes (FCCH), yet few studies have examined PA levels and ethnicity differences in PA levels among these children. We examine baseline data from a cluster-randomized trial (Healthy Start/Comienzos Sanos) to improve food and PA environments in FCCHs. Children aged 2-to-5-years (n = 342) wore triaxial accelerometers for two days in FCCHs. Variables examined include percentage of time (%) spent in sedentary, and light, moderate, and vigorous PA. The full dataset (n = 342) indicated sedentary behavior 62% ± 11% of the time and only 10% ± 5% of the time spent in moderate-to-vigorous PA. Among children in the upper-median half of wear-time (n = 176), Hispanic children had significantly greater % sedentary time vs. Non-Hispanic children (66.2% ± 8.3% vs. 62.6% ± 6.9%, p = 0.007), and lower % light PA (25.4% ± 6.3% vs. 27.7% ± 4.9%, p = 0.008) and moderate PA (5.5% ± 2.1% vs. 6.4% ± 2.2%, p = 0.018). Our results highlight that PA levels were lower among our sample compared to previous studies, and that Hispanic children were more sedentary and less active compared to non-Hispanic white children

Effects of Network Connectivity and Diversity Distribution on Human Collective Ideation

Human collectives, e.g., teams and organizations, increasingly require participation of members with diverse backgrounds working in networked social environments. However, little is known about how network structure and the diversity of member backgrounds would affect collective processes. Here we conducted three sets of human-subject experiments which involved 617 participants who collaborated anonymously in a collective ideation task on a custom-made online social network platform. We found that spatially clustered collectives with clustered background distribution tended to explore more diverse ideas than in other conditions, whereas collectives with random background distribution consistently generated ideas with the highest utility. We also found that higher network connectivity may improve individuals' overall experience but may not improve the collective performance regarding idea generation, idea diversity, and final idea quality.Comment: 43 pages, 19 figures, 4 table

Efficiency Enhancement of Organic Solar Cells Using Transparent Plasmonic Ag Nanowire Electrodes

No AbstractPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78248/1/4378_ftp.pd

A comparative study of semiconductor-based plasmonic metamaterials

Recent metamaterial (MM) research faces several problems when using metal-based plasmonic components as building blocks for MMs. The use of conventional metals for MMs is limited by several factors: metals such as gold and silver have high losses in the visible and near-infrared (NIR) ranges and very large negative real permittivity values, and in addition, their optical properties cannot be tuned. These issues that put severe constraints on the device applications of MMs could be overcome if semiconductors are used as plasmonic materials instead of metals. Heavily doped, wide bandgap oxide semiconductors could exhibit both a small negative real permittivity and relatively small losses in the NIR. Heavily doped oxides of zinc and indium were already reported to be good, low loss alternatives to metals in the NIR range. Here, we consider these transparent conducting oxides (TCOs) as alternative plasmonic materials for many specific applications ranging from surface-plasmon-polariton waveguides to MMs with hyperbolic dispersion and epsilon-near-zero (ENZ) materials. We show that TCOs outperform conventional metals for ENZ and other MM-applications in the NIR.Comment: 16 pages, 7 figure

Electrical Control of Plasmon Resonance with Graphene

Surface plasmon, with its unique capability to concentrate light into sub-wavelength volume, has enabled great advances in photon science, ranging from nano-antenna and single-molecule Raman scattering to plasmonic waveguide and metamaterials. In many applications it is desirable to control the surface plasmon resonance in situ with electric field. Graphene, with its unique tunable optical properties, provides an ideal material to integrate with nanometallic structures for realizing such control. Here we demonstrate effective modulation of the plasmon resonance in a model system composed of hybrid graphene-gold nanorod structure. Upon electrical gating the strong optical transitions in graphene can be switched on and off, which leads to significant modulation of both the resonance frequency and quality factor of plasmon resonance in gold nanorods. Hybrid graphene-nanometallic structures, as exemplified by this combination of graphene and gold nanorod, provide a general and powerful way for electrical control of plasmon resonances. It holds promise for novel active optical devices and plasmonic circuits at the deep subwavelength scale