Preliminary Evidence for cue-induced Alcohol Craving Modulated by Serotonin Transporter Gene Polymorphism rs1042173

We previously have shown that cue-induced alcohol craving and propensity for higher drinking are modulated by allelic differences in SLC6A4 associated with serotonin transporter (5-HTT) expression level alterations. In an independent study, we characterized another polymorphism, SNP rs1042173, in 3′-untranslated region (3′-UTR) of the same gene, which also altered 5-HTT expression levels; the T allele of rs1042173 was associated with lower mRNA and protein levels. In subsequent analyses, the TT genotype was found to be associated with higher drinking intensity in alcohol-dependent (AD) individuals of Caucasian descent. Building upon these findings, we hypothesized that the low-expressing TT genotype associated with intense drinking would predict higher craving for alcohol in AD individuals. In this pilot study, we sought to test our hypothesis by examining 34 Hispanic AD volunteers (mean age, 34.8 years) for rs1042173 genotype-based [i.e., TT versus TG/GG (Gx)] differences in subjective response to alcohol. We employed a human laboratory paradigm and analyzed the data using a linear mixed-effects model (SAS® PROC MIXED) to assess treatment, cue procedures, and genotype main effects as well as the two-way interaction effects between them. On subjective “urge to drink” and “crave for a drink,” we found a significant main effect of the cue experiment (p ≤ 0.01) and an interaction effect between genotype and cue effects (p < 0.05). TT genotype was associated with higher urge to drink (p = 0.002) and crave for a drink (p = 0.005) when exposed to alcohol cue. Our results not only support the hypothesis that rs1042173 is a genetic marker for cue-induced alcohol craving among AD males but also are suggestive of a neurobiological mechanism associated with the rs1042173-TT genotype that triggers a disproportionate craving in response to alcohol consumption, which in turn may lead to more intense drinking. Future studies with larger sample sizes are needed to characterize the interactive effects of the serotonin transporter-linked polymorphic region (5′-HTTLPR)-L-allele reported in our previous study and of the rs1042173-TT genotype on cue-induced alcohol craving

Measurement of the extragalactic background light spectral energy distribution with VERITAS

The extragalactic background light (EBL), a diffuse photon field in the optical and infrared range, is a record of radiative processes over the Universe's history. Spectral measurements of blazars at very high energies ($>$100 GeV) enable the reconstruction of the spectral energy distribution (SED) of the EBL, as the blazar spectra are modified by redshift- and energy-dependent interactions of the gamma-ray photons with the EBL. The spectra of 14 VERITAS-detected blazars are included in a new measurement of the EBL SED that is independent of EBL SED models. The resulting SED covers an EBL wavelength range of 0.56--56 $\mu$m, and is in good agreement with lower limits obtained by assuming that the EBL is entirely due to radiation from cataloged galaxies.Comment: Accepted for publication in The Astrophysical Journa

Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M ⊙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded