Neutrino-induced deuteron disintegration experiment

Cross sections for the disintegration of the deuteron via neutral-current (NCD) and charged-current (CCD) interactions with reactor antineutrinos are measured to be 6.08 +/- 0.77 x 10^(-45) cm-sq and 9.83 +/- 2.04 x 10^(-45) cm-sq per neutrino, respectively, in excellent agreement with current calculations. Since the experimental NCD value depends upon the CCD value, if we use the theoretical value for the CCD reaction, we obtain the improved value of 5.98 +/- 0.54 x 10^(-45) for the NCD cross section. The neutral-current reaction allows a unique measurement of the isovector-axial vector coupling constant in the hadronic weak interaction (beta). In the standard model, this constant is predicted to be exactly 1, independent of the Weinberg angle. We measure a value of beta^2 = 1.01 +/- 0.16. Using the above improved value for the NCD cross section, beta^2 becomes 0.99 +/- 0.10.Comment: 22pages, 9 figure

The gene encoding the fragile X RNA-binding protein is controlled by nuclear respiratory factor 2 and the CREB family of transcription factors

FMR1 encodes an RNA-binding protein whose absence results in fragile X mental retardation. In most patients, the FMR1 gene is cytosine-methylated and transcriptionally inactive. NRF-1 and Sp1 are known to bind and stimulate the active, but not the methylated/silenced, FMR1 promoter. Prior analysis has implicated a CRE site in regulation of FMR1 in neural cells but the role of this site is controversial. We now show that a phospho-CREB/ATF family member is bound to this site in vivo. We also find that the histone acetyltransferases CBP and p300 are associated with active FMR1 but are lost at the hypoacetylated fragile X allele. Surprisingly, FMR1 is not cAMP-inducible and resides in a newly recognized subclass of CREB-regulated genes. We have also elucidated a role for NRF-2 as a regulator of FMR1 in vivo through a previously unrecognized and highly conserved recognition site in FMR1. NRF-1 and NRF-2 act additively while NRF-2 synergizes with CREB/ATF at FMR1's promoter. These data add FMR1 to the collection of genes controlled by both NRF-1 and NRF-2 and disfavor its membership in the immediate early response group of genes

Variable Hard X-ray Emission from the Candidate Accreting Black Hole in Dwarf Galaxy Henize 2-10

We present an analysis of the X-ray spectrum and long-term variability of the nearby dwarf starburst galaxy Henize 2-10. Recent observations suggest that this galaxy hosts an actively accreting black hole with mass ~10^6 M_sun. The presence of an AGN in a low-mass starburst galaxy marks a new environment for active galactic nuclei (AGNs), with implications for the processes by which "seed" black holes may form in the early Universe. In this paper, we analyze four epochs of X-ray observations of Henize 2-10, to characterize the long-term behavior of its hard nuclear emission. We analyze observations with Chandra from 2001 and XMM-Newton from 2004 and 2011, as well as an earlier, less sensitive observation with ASCA from 1997. Based on detailed analysis of the source and background, we find that the hard (2-10 keV) flux of the putative AGN has decreased by approximately an order of magnitude between the 2001 Chandra observation and exposures with XMM-Newton in 2004 and 2011. The observed variability confirms that the emission is due to a single source. It is unlikely that the variable flux is due to a supernova or ultraluminous X-ray source, based on the observed long-term behavior of the X-ray and radio emission, while the observed X-ray variability is consistent with the behavior of well-studied AGNs.Comment: 7 pages, 4 figures, 2 tables; accepted for publication in Ap

The Effect of AGN on the Global HI Content of Isolated Low-Mass Galaxies

We investigate the global neutral hydrogen (HI) content of isolated galaxies selected from the SDSS spectroscopic survey with optical evidence of Active Galactic Nuclei (AGN). Our sample includes galaxies with unresolved HI observations from the ALFALFA 70% data release combined with deeper HI observations of low-mass galaxies with 7.0 < log(M*) < 9.5. We examine the HI masses of this sample using the distance from the star-forming sequence on the OIII\Hb and NII\Ha Baldwin Phillips Terlevich (BPT) diagram as a measurement of AGN activity. In agreement with previous studies, we find that, for galaxies with log(M*) > 9.5, AGN activity does not correlate with the global HI content. However, for galaxies with 9.2 < log(M*) < 9.5, we identify a set of objects at large distances from the BPT star-forming sequence and lower than expected HI masses. This gas-depleted sample is red in both g-r and NUV-r colors and compact without distinguishable signs of star formation. This is surprising because the vast majority of isolated galaxies in this stellar mass regime are both star-forming and gas-rich. These galaxies are greater than 1.5 Mpc from any massive galaxy, ruling out environmental processes as a source of the gas-depletion. We suggest that either black hole feedback or shocks from extremely bursty star formation cause the emission lines and have destroyed or otherwise consumed the cold gas.Comment: Accepted to ApJ, 14 pages, 7 figure

Efficacy of escitalopram in the treatment of social anxiety disorder: A meta-analysis versus placebo

Escitalopram is the most selective of the serotonin reuptake inhibitor (SSRI) antidepressants. We conducted a meta-analysis of placebo-controlled studies where escitalopram was used to treat patients with social anxiety disorder (SAD). Data from all randomised, double-blind placebo-controlled studies in SAD with escitalopram from both specialist settings and general practice were used. Patients met the DSM-IV criteria for SAD, ?18 years old, Liebowitz Social Anxiety Scale (LSAS) ?60. The primary outcome measure was the estimated treatment difference in LSAS total score at Week 12. Secondary outcome measures included the estimated treatment difference in the Clinical Global Impression-Severity (CGI-S) score at Week 12. A total of 1598 patients from 3 randomised controlled trials were included in the analyses. Escitalopram (n=1,061) was superior to placebo (n=537), with an estimated treatment difference on the LSAS of ?9.2 points (95%CI: [?14.4; ?4.0], p&lt;0.01) (escitalopram 5 mg/day), ?4.6 points (95%CI: [?8.1; ?1.0], p&lt;0.01) (escitalopram 10 mg/day), ?10.1 points (95%CI: [?13.7; ?6.5], p&lt;0.01) (escitalopram 20 mg/day) and ?7.3 points (95%CI: [?12.3; ?2.2], p&lt;0.01) (escitalopram 10-20 mg/day). For the CGI-S, the corresponding values were ?0.55 points (95%CI: [?0.79; ?0.31], p&lt;0.01) (escitalopram 5 mg/day), ?0.26 points (95%CI: [?0.42; ?0.10], p&lt;0.01) (escitalopram 10 mg/day), ?0.48 points (95%CI: [?0.64; ?0.31], p&lt;0.01) (escitalopram 20 mg/day) and ?0.29 points (95%CI: [?0.51; ?0.07], p&lt;0.05) (escitalopram 10-20 mg/day). The withdrawal rate due to adverse events was 7.2% for escitalopram, compared with 4.3% for placebo (p&lt;0.05). In this meta-analysis, all doses of escitalopram showed significant superiority in efficacy versus placebo in the treatment of patients with SAD

The Infrared Properties of Hickson Compact Groups

Compact groups of galaxies provide a unique environment to study the mechanisms by which star formation occurs amid continuous gravitational encounters. We present 2MASS (JHK), Spitzer IRAC (3.5-8 micron) and MIPS (24 micron) observations of a sample of twelve Hickson Compact Groups (HCGs 2, 7, 16, 19, 22, 31, 42, 48, 59, 61, 62, and 90) that includes a total of 45 galaxies. The near-infrared colors of the sample galaxies are largely consistent with being dominated by slightly reddened normal stellar populations. Galaxies that have the most significant PAH and/or hot dust emission (as inferred from excess 8 micron flux) also tend to have larger amounts of extinction and/or K-band excess and stronger 24 micron emission, all of which suggest ongoing star formation activity. We separate the twelve HCGs in our sample into three types based on the ratio of the group HI mass to dynamical mass. We find evidence that galaxies in the most gas-rich groups tend to be the most actively star forming. Galaxies in the most gas-poor groups tend to be tightly clustered around a narrow range in colors consistent with the integrated light from a normal stellar population. We interpret these trends as indicating that galaxies in gas-rich groups experience star formation and/or nuclear actively until their neutral gas consumed, stripped, or ionized. The galaxies in this sample exhibit a ``gap'' between gas-rich and gas-poor groups in infrared color space that is sparsely populated and not seen in the Spitzer First Look Survey sample. This gap may suggest a rapid evolution of galaxy properties in response to dynamical effects. These results suggest that the global properties of the groups and the local properties of the galaxies are connected.Comment: 34 pages, 26 figures, accepted for publication in AJ, higher quality images available in publicatio

Neutrinos in a spherical box

In the present paper we study some neutrino properties as they may appear in the low energy neutrinos emitted in triton decay with maximum neutrino energy of 18.6 keV. The technical challenges to this end can be achieved by building a very large TPC capable of detecting low energy recoils, down to a a few tenths of a keV, within the required low background constraints. More specifically We propose the development of a spherical gaseous TPC of about 10-m in radius and a 200 Mcurie triton source in the center of curvature. One can list a number of exciting studies, concerning fundamental physics issues, that could be made using a large volume TPC and low energy antineutrinos: 1) The oscillation length involving the small angle of the neutrino mixing matrix, directly measured in this disappearance experiment, is fully contained inside the detector. Measuring the counting rate of neutrino-electron elastic scattering as a function of the distance of the source will give a precise and unambiguous measurement of the oscillation parameters free of systematic errors. In fact first estimates show that even with a year's data taking a sensitivity of a few percent for the measurement of the above angle will be achieved. 2) The low energy detection threshold offers a unique sensitivity for the neutrino magnetic moment which is about two orders of magnitude beyond the current experimental limit. 3) Scattering at such low neutrino energies has never been studied and any departure from the expected behavior may be an indication of new physics beyond the standard model. In this work we mainly focus on the various theoretical issues involved including a precise determination of the Weinberg angle at very low momentum transfer.Comment: 16 Pages, LaTex, 7 figures, talk given at NANP 2003, Dubna, Russia, June 23, 200

Reactor-based Neutrino Oscillation Experiments

The status of neutrino oscillation searches employing nuclear reactors as sources is reviewed. This technique, a direct continuation of the experiments that proved the existence of neutrinos, is today an essential tool in investigating the indications of oscillations found in studying neutrinos produced in the sun and in the earth's atmosphere. The low-energy of the reactor \nuebar makes them an ideal tool to explore oscillations with small mass differences and relatively large mixing angles. In the last several years the determination of the reactor anti-neutrino flux and spectrum has reached a high degree of accuracy. Hence measurements of these quantities at a given distance L can be readily compared with the expectation at L = 0, thus testing \nuebar disappearance. While two experiments, Chooz and Palo Verde, with baselines of about 1 km and thus sensitive to the neutrino mass differences associated with the atmospheric neutrino anomaly, have collected data and published results recently, an ambitious project with a baseline of more than 100 km, Kamland, is preparing to take data. This ultimate reactor experiment will have a sensitivity sufficient to explore part of the oscillation phase space relevant to solar neutrino scenarios. It is the only envisioned experiment with a terrestrial source of neutrinos capable of addressing the solar neutrino puzzle.Comment: Submitted to Reviews of Modern Physics 34 pages, 39 figure