4,747 research outputs found
Long-Term Outcomes of Cognitive-Behavioral Therapy for Adolescent Body Dysmorphic Disorder
Emerging evidence suggests that cognitive-behavioral therapy (CBT) is an efficacious treatment for adolescent body dysmorphic disorder (BDD) in the short term, but longer-term outcomes remain unknown. The current study aimed to follow up a group of adolescents who had originally participated in a randomized controlled trial of CBT for BDD to determine whether treatment gains were maintained. Twenty-six adolescents (mean age = 16.2, SD = 1.6) with a primary diagnosis of BDD received a course of developmentally tailored CBT and were followed up over 12 months. Participants were assessed at baseline, midtreatment, posttreatment, 2-, 6-, and 12-month follow-up. The primary outcome measure was the clinician-rated Yale-Brown Obsessive-Compulsive Scale Modified for BDD. Secondary outcomes included measures of insight, depression, quality of life, and global functioning. BDD symptoms decreased significantly from pre- to posttreatment and remained stable over the 12-month follow-up. At this time point, 50% of participants were classified as responders and 23% as remitters. Participants remained significantly improved on all secondary outcomes at 12-month follow-up. Neither baseline insight nor baseline depression predicted long-term outcomes. The positive effects of CBT appear to be durable up to 12-month follow-up. However, the majority of patients remained symptomatic and vulnerable to a range of risks at 12-month follow-up, indicating that longer-term monitoring is advisable in this population. Future research should focus on enhancing the efficacy of CBT in order to improve long-term outcomes.Full Tex
Constraints on inelastic dark matter from XENON10
It has been suggested that dark matter particles which scatter inelastically
from detector target nuclei could explain the apparent incompatibility of the
DAMA modulation signal (interpreted as evidence for particle dark matter) with
the null results from CDMS-II and XENON10. Among the predictions of
inelastically interacting dark matter are a suppression of low-energy events,
and a population of nuclear recoil events at higher nuclear recoil equivalent
energies. This is in stark contrast to the well-known expectation of a falling
exponential spectrum for the case of elastic interactions. We present a new
analysis of XENON10 dark matter search data extending to E keV
nuclear recoil equivalent energy. Our results exclude a significant region of
previously allowed parameter space in the model of inelastically interacting
dark matter. In particular, it is found that dark matter particle masses
GeV are disfavored.Comment: 8 pages, 4 figure
A search for light dark matter in XENON10 data
We report results of a search for light (<10 GeV) particle dark matter with
the XENON10 detector. The event trigger was sensitive to a single electron,
with the analysis threshold of 5 electrons corresponding to 1.4 keV nuclear
recoil energy. Considering spin-independent dark matter-nucleon scattering, we
exclude cross sections \sigma_n>3.5x10^{-42} cm^2, for a dark matter particle
mass m_{\chi}=8 GeV. We find that our data strongly constrain recent elastic
dark matter interpretations of excess low-energy events observed by CoGeNT and
CRESST-II, as well as the DAMA annual modulation signal.Comment: Manuscript identical to v2 (published version) but also contains
erratum. Note v3==v2 but without \linenumber
3D Position Sensitive XeTPC for Dark Matter Search
The technique to realize 3D position sensitivity in a two-phase xenon time
projection chamber (XeTPC) for dark matter search is described. Results from a
prototype detector (XENON3) are presented.Comment: Presented at the 7th UCLA Symposium on "Sources and Detection of Dark
Matter and Dark Energy in the Universe
Search for Early Gamma-ray Production in Supernovae Located in a Dense Circumstellar Medium with the Fermi LAT
Supernovae (SNe) exploding in a dense circumstellar medium (CSM) are
hypothesized to accelerate cosmic rays in collisionless shocks and emit GeV
gamma rays and TeV neutrinos on a time scale of several months. We perform the
first systematic search for gamma-ray emission in Fermi LAT data in the energy
range from 100 MeV to 300 GeV from the ensemble of 147 SNe Type IIn exploding
in dense CSM. We search for a gamma-ray excess at each SNe location in a one
year time window. In order to enhance a possible weak signal, we simultaneously
study the closest and optically brightest sources of our sample in a
joint-likelihood analysis in three different time windows (1 year, 6 months and
3 months). For the most promising source of the sample, SN 2010jl (PTF10aaxf),
we repeat the analysis with an extended time window lasting 4.5 years. We do
not find a significant excess in gamma rays for any individual source nor for
the combined sources and provide model-independent flux upper limits for both
cases. In addition, we derive limits on the gamma-ray luminosity and the ratio
of gamma-ray-to-optical luminosity ratio as a function of the index of the
proton injection spectrum assuming a generic gamma-ray production model.
Furthermore, we present detailed flux predictions based on multi-wavelength
observations and the corresponding flux upper limit at 95% confidence level
(CL) for the source SN 2010jl (PTF10aaxf).Comment: Accepted for publication in ApJ. Corresponding author: A. Franckowiak
([email protected]), updated author list and acknowledgement
New limits on nucleon decays into invisible channels with the BOREXINO Counting Test Facility
The results of background measurements with the second version of the
BOREXINO Counting Test Facility (CTF-II), installed in the Gran Sasso
Underground Laboratory, were used to obtain limits on the instability of
nucleons, bounded in nuclei, for decays into invisible channels ():
disappearance, decays to neutrinos, etc. The approach consisted of a search for
decays of unstable nuclides resulting from and decays of parents
C, C and O nuclei in the liquid scintillator and the water
shield of the CTF. Due to the extremely low background and the large mass (4.2
ton) of the CTF detector, the most stringent (or competitive) up-to-date
experimental bounds have been established: y, y, y and y, all at 90% C.L.Comment: 22 pages, 3 figures,submitted to Phys.Lett.
Fermi-LAT Study of Gamma-ray Emission in the Direction of Supernova Remnant W49B
We present an analysis of the gamma-ray data obtained with the Large Area
Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the direction of
SNR W49B (G43.3-0.2). A bright unresolved gamma-ray source detected at a
significance of 38 sigma is found to coincide with SNR W49B. The energy
spectrum in the 0.2-200 GeV range gradually steepens toward high energies. The
luminosity is estimated to be 1.5x10^{36} (D/8 kpc)^2 erg s^-1 in this energy
range. There is no indication that the gamma-ray emission comes from a pulsar.
Assuming that the SNR shell is the site of gamma-ray production, the observed
spectrum can be explained either by the decay of neutral pi mesons produced
through the proton-proton collisions or by electron bremsstrahlung. The
calculated energy density of relativistic particles responsible for the LAT
flux is estimated to be remarkably large, U_{e,p}>10^4 eV cm^-3, for either
gamma-ray production mechanism.Comment: 9 pages, 10 figure
On-ground performance tests of the SAX/PDS detector
The Phoswich Detection System (PDS) is one of the four narrow field experiments on board the SAX satellite. The PDS will be dedicated to deep temporal and spectral studies of celestial X-ray sources in the 15–300 keV energy band. It
also includes a gamma-ray burst monitor. The PDS detector is composed of 4 actively shielded NaI(Tl)/CsI(Na) phoswich scintillators with a total geometric area of 795 cm2 and a field of view of 1:4 (FWHM). The performance of the detector, before its integration with its flight electronic, was tested using standard instrumentation. Here we present results of these tests. The measured energy resolution of the phoswich units is better than 15% at 60 keV, confirming the expectations. Also test results of the anticoincidence shield of CsI(Na) and collimator are discussed
Multiwavelength Evidence for Quasi-periodic Modulation in the Gamma-ray Blazar PG 1553+113
We report for the first time a gamma-ray and multi-wavelength nearly-periodic
oscillation in an active galactic nucleus. Using the Fermi Large Area Telescope
(LAT) we have discovered an apparent quasi-periodicity in the gamma-ray flux (E
>100 MeV) from the GeV/TeV BL Lac object PG 1553+113. The marginal significance
of the 2.18 +/-0.08 year-period gamma-ray cycle is strengthened by correlated
oscillations observed in radio and optical fluxes, through data collected in
the OVRO, Tuorla, KAIT, and CSS monitoring programs and Swift UVOT. The optical
cycle appearing in ~10 years of data has a similar period, while the 15 GHz
oscillation is less regular than seen in the other bands. Further long-term
multi-wavelength monitoring of this blazar may discriminate among the possible
explanations for this quasi-periodicity.Comment: 8 pages, 5 figures. Accepted to The Astrophysical Journal Letters.
Corresponding authors: S. Ciprini (ASDC/INFN), S. Cutini (ASDC/INFN), S.
Larsson (Stockholm Univ/KTH), A. Stamerra (INAF/SNS), D. J. Thompson (NASA
GSFC
Detection of 16 Gamma-Ray Pulsars Through Blind Frequency Searches Using the Fermi LAT
Pulsars are rapidly-rotating, highly-magnetized neutron stars emitting
radiation across the electromagnetic spectrum. Although there are more than
1800 known radio pulsars, until recently, only seven were observed to pulse in
gamma rays and these were all discovered at other wavelengths. The Fermi Large
Area Telescope makes it possible to pinpoint neutron stars through their
gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind
frequency searches using the LAT. Most of these pulsars are coincident with
previously unidentified gamma-ray sources, and many are associated with
supernova remnants. Direct detection of gamma-ray pulsars enables studies of
emission mechanisms, population statistics and the energetics of pulsar wind
nebulae and supernova remnants.Comment: Corresponding authors: Michael Dormody, Paul S. Ray, Pablo M. Saz
Parkinson, Marcus Ziegle
- …
