334 research outputs found

    The Composite Fermion Hierarchy: Condensed States of Composite Fermion Excitations?

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    A composite Fermion hierarchy theory is constructed in a way related to the original Haldane picture by applying the composite Fermion (CF) transformation to quasiparticles of Jain states. It is shown that the Jain theory coincides with the Haldane hierarchy theory for principal CF fillings. Within the Fermi liquid approach for few electron systems on the sphere a simple interpretation of many-quasiparticle spectra is given and provides an explanation of failure of CF hierarchy picture when applied to the hierarchical 4/114/11 state.Comment: 6 pages, Revtex, 4 figures in PostScript, submitted to Phys. Rev. Let

    Meta-analysis and Meta-regression of Cognitive Behavioral Therapy for Psychosis (CBTp) Across Time: The Effectiveness of CBTp has Improved for Delusions

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    Published research shows small-to-medium effects of Cognitive Behavioral Therapy for Psychosis (CBTp) on reducing psychotic symptoms. Given the on-going development of CBTp interventions, the aim of this systematic review is to examine whether the effectiveness of CBTp has changed across time. MEDLINE, EMBASE, PsycINFO, and CENTRAL were searched for randomized controlled trials examining CBTp interventions targeting positive and/or negative symptoms vs treatment as usual. Four meta-analyses were carried out to examine the effectiveness of CBTp for: positive symptoms; delusions; hallucinations; and negative symptoms. Four meta-regressions examined whether the effectiveness of CBTp changed across time for these groups of symptoms. A total of 28 studies (n = 2698) yielded a pooled g of −0.24 (95% confidence interval [CI] −0.32, −0.16, P < .001) favoring CBTp for positive symptoms, with nonsignificant heterogeneity (Q = 26.87, P = .47; I2 =0%); 13 studies (n = 890) yielded a pooled g of −0.36 (95% CI −0.59, −0.13, P = .002) for delusions, with substantial heterogeneity (Q = 31.99, P = .001; I2 =62%); 16 studies (n = 849) yielded a pooled g of −0.26 (95% CI −0.42, −0.11, P < .001) for hallucinations, with nonsignificant heterogeneity (Q = 18.10, P = .26; I2 =17%); 19 studies (n = 1761) yielded a pooled g of −0.22 (95% CI −0.33, −0.12, P < .001) for negative symptoms, with nonsignificant heterogeneity (Q = 20.32, P = .32, I2 =11%). Meta-regressions indicated a significant effect of year on the effectiveness of CBTp only for delusions (F[1, 11] = 5.99, P = .032; R2 = 0.594); methodological quality did not effect this finding. Findings indicate small-to-medium effects of CBTp for psychotic symptoms, with increasing effectiveness across time for delusions

    Quantum Hall Spherical Systems: the Filling Fraction

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    Within the newly formulated composite fermion hierarchy the filling fraction of a spherical quantum Hall system is obtained when it can be expressed as an odd or even denominator fraction. A plot of ν2SN−1\nu\frac{2S}{N-1} as a function of 2S2S for a constant number of particles (up to N=10001) exhibits structure of the fractional quantum Hall effect. It is confirmed that νe+νh=1\nu_e +\nu_h=1 for all particle-hole conjugate systems, except systems with Ne=NhN_e =N_h, and Ne=Nh±1N_e=N_h \pm 1.Comment: 3 pages, Revtex, 7 PostScript figures, submitted to Phys. Rev. B Rapid Communicatio

    Silicate Emission in the TW Hydrae Association

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    The TW Hydrae Association is the nearest young stellar association. Among its members are HD 98800, HR 4796A, and TW Hydrae itself, the nearest known classical T Tauri star. We have observed these three stars spectroscopically between 3 and 13 microns. In TW Hya the spectrum shows a silicate emission feature that is similar to many other young stars with protostellar disks. The 11.2 micron feature indicative of significant amounts of crystalline olivine is not as strong as in some young stars and solar system comets. In HR 4796A, the thermal emission in the silicate feature is very weak, suggesting little in the way of (small silicate) grains near the star. The silicate band of HD 98800 (observed by us but also reported by Sylvester and Skinner (1996)) is intermediate in strength between TW Hya and HR 4796.Comment: 22 pages, 11 figures, LaTeX2e and AAS LaTeX macros v5.0. Accepted for publication in A

    FUSE Spectroscopy of the Two Prototype White Dwarfs With Signatures of a Super-hot Wind

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    The O VIII phenomenon describes the occurrence of ultra-high ionization absorption lines of the CNO elements (e.g. O VIII, N VII, C VI, and even Ne X) in the optical spectra hot of DO WDs

    Mid-Infrared Ethane Emission on Neptune and Uranus

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    We report 8- to 13-micron spectral observations of Neptune and Uranus from the NASA Infrared Telescope Facility spanning more than a decade. The spectroscopic data indicate a steady increase in Neptune's mean atmospheric 12-micron ethane emission from 1985 to 2003, followed by a slight decrease in 2004. The simplest explanation for the intensity variation is an increase in stratospheric effective temperature from 155 +/- 3 K in 1985 to 176 +/- 3 K in 2003 (an average rate of 1.2 K/year), and subsequent decrease to 165 +/- 3 K in 2004. We also detected variation of the overall spectral structure of the ethane band, specifically an apparent absorption structure in the central portion of the band; this structure arises from coarse spectral sampling coupled with a non-uniform response function within the detector elements. We also report a probable direct detection of ethane emission on Uranus. The deduced peak mole fraction is approximately an order of magnitude higher than previous upper limits for Uranus. The model fit suggests an effective temperature of 114 +/- 3 K for the globally-averaged stratosphere of Uranus, which is consistent with recent measurements indicative of seasonal variation.Comment: Accepted for publication in ApJ. 16 pages, 10 figures, 2 table

    The continued optical to mid-IR evolution of V838 Monocerotis

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    The eruptive variable V838 Monocerotis gained notoriety in 2002 when it brightened nine magnitudes in a series of three outbursts and then rapidly evolved into an extremely cool supergiant. We present optical, near-IR, and mid-IR spectroscopic and photometric observations of V838 Monocerotis obtained between 2008 and 2012 at the Apache Point Observatory 3.5m, NASA IRTF 3m, and Gemini South 8m telescopes. We contemporaneously analyze the optical & IR spectroscopic properties of V838 Monocerotis to arrive at a revised spectral type L3 supergiant and effective temperature Teff~2000--2200 K. Because there are no existing optical observational data for L supergiants in the optical, we speculate that V838 Monocerotis may represent the prototype for L supergiants in this wavelength regime. We find a low level of Halpha emission present in the system, consistent with interaction between V838 Monocerotis and its B3V binary; however, we cannot rule out a stellar collision as the genesis event, which could result in the observed Halpha activity. Based upon a two-component blackbody fit to all wavelengths of our data, we conclude that, as of 2009, a shell of ejecta surrounded V838 Monocerotis at a radius of R=263+/-10 AU with a temperature of T=285+/-2 K. This result is consistent with IR interferometric observations from the same era and predictions from the Lynch et al. model of the expanding system, which provides a simple framework for understanding this complicated system.Comment: 6 pages, 2 tables, 6 figures; accepted to A

    Home Is Where You Hang Your Hat: Host Town Identity, But Not Hometown Identity, Protects Against Mental Health Symptoms Associated with Financial Stress

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    Debt and financial insecurity are associated with stress, low self-worth, and poor health. Joining and identifying with social groups (social identification) promotes better health and higher self-esteem. Here, we examined whether identifying with one's local neighborhood protected people from developing mental health symptoms associated with financial stress. We analyzed data from a general population survey (Study 1, N = 4319) and a student mental health survey (Study 2, N = 612) conducted in the North West of England. We administered measures of financial stress, self-esteem, neighborhood identity, and mental health, and conducted moderated mediation analyses to test our predictions. Study 1 (population survey) demonstrated that stronger identification with one's local neighborhood attenuated the adverse effects of financial stress on self-esteem and subsequent mental health. Study 2 (student survey) showed that strong host town identities buffered students from mental health symptoms related to financial stress. Strong hometown identities, however, showed no buffering effect. The findings suggest that one way financial stress impacts mental health is by eroding self-esteem. Identifying with one's current place of residence appears to disrupt this pathway, while identifying with one's previous place of residence does not provide the same psychological protection. Read More: https://guilfordjournals.com/doi/10.1521/jscp.2018.37.3.15
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