365 research outputs found
Spitzer Observations of 3C Quasars and Radio Galaxies: Mid-Infrared Properties of Powerful Radio Sources
We have measured mid-infrared radiation from an orientation-unbiased sample
of 3CRR galaxies and quasars at redshifts 0.4 < z < 1.2 with the IRS and MIPS
instruments on the Spitzer Space Telescope. Powerful emission (L_24micron >
10^22.4 W/Hz/sr) was detected from all but one of the sources. We fit the
Spitzer data as well as other measurements from the literature with synchrotron
and dust components. The IRS data provide powerful constraints on the fits. At
15 microns, quasars are typically four times brighter than radio galaxies with
the same isotropic radio power. Based on our fits, half of this difference can
be attributed to the presence of non-thermal emission in the quasars but not
the radio galaxies. The other half is consistent with dust absorption in the
radio galaxies but not the quasars. Fitted optical depths are anti-correlated
with core dominance, from which we infer an equatorial distribution of dust
around the central engine. The median optical depth at 9.7 microns for objects
with core-dominance factor R > 10^-2 is approximately 0.4; for objects with R <
10^-2, it is 1.1. We have thus addressed a long-standing question in the
unification of FR II quasars and galaxies: quasars are more luminous in the
mid-infrared than galaxies because of a combination of Doppler-boosted
synchrotron emission in quasars and extinction in galaxies, both
orientation-dependent effects.Comment: 42 pages, 14 figures plus two landscape tables. Accepted for
publication in Ap
Impact of mental health problems on case fatality in male cancer patients
Background: Although mortality rates are elevated in psychiatric patients relative to their healthy counterparts, little is known about the impact of mental health on survival in people with cancer. / Methods and results: Among 16β498 Swedish men with cancer, survival was worse in those with a history of psychiatric hospital admissions: multiply-adjusted hazard ratio (95% confidence interval) comparing cancer mortality in men with and without psychiatric admissions: 1.59 (1.39, 1.83). / Conclusion: Survival in cancer patients is worse among those with a history of psychiatric disease. The mechanisms underlying this association should be further explored
Non-specific psychological distress, smoking status and smoking cessation: United States National Health Interview Survey 2005
<p>Abstract</p> <p>Background</p> <p>It is well established that smoking rates in people with common mental disorders such as anxiety or depressive disorders are much higher than in people without mental disorders. It is less clear whether people with these mental disorders want to quit smoking, attempt to quit smoking or successfully quit smoking at the same rate as people without such disorders.</p> <p>Methods</p> <p>We used data from the 2005 Cancer Control Supplement to the United States National Health Interview Survey to explore the relationship between psychological distress as measured using the K6 scale and smoking cessation, by comparing current smokers who had tried unsuccessfully to quit in the previous 12 months to people able to quit for at least 7 to 24 months prior to the survey. We also used data from the 2007 Australian National Survey of Mental Health and Wellbeing to examine the relationship between psychological distress (K6) scores and duration of mental illness.</p> <p>Results</p> <p>The majority of people with high K6 psychological distress scores also meet diagnostic criteria for mental disorders, and over 90% of these people had first onset of mental disorder more than 2 years prior to the survey. We found that people with high levels of non-specific psychological distress were more likely to be current smokers. They were as likely as people with low levels of psychological distress to report wanting to quit smoking, trying to quit smoking, and to have used smoking cessation aids. However, they were significantly less likely to have quit smoking.</p> <p>Conclusions</p> <p>The strong association between K6 psychological distress scores and mental disorders of long duration suggests that the K6 measure is a useful proxy for ongoing mental health problems. As people with anxiety and depressive disorders make up a large proportion of adult smokers in the US, attention to the role of these disorders in smoking behaviours may be a useful area of further investigation for tobacco control.</p
The association between failed quit attempts and increased levels of psychological distress in smokers in a large New Zealand cohort
<p>Abstract</p> <p>Background</p> <p>Although the association between smoking status and poorer mental health has been well documented, the association between quit status and psychological distress is less clear. The aim of the present study is to investigate the association of smoking status and quit status with psychological distress.</p> <p>Methods</p> <p>Data for this study is from a single year of the Survey of Families, Income and Employment (SoFIE) conducted in New Zealand (2004/05) (n = 18,525 respondents). Smoking status and quit status were treated as exposure variables, and psychological distress (Kessler-10) was treated as the outcome variable. Logistic regression analyses were performed to determine the association of smoking with psychological distress in the whole adult population and quit status with psychological distress in the ex- and current-smoking population.</p> <p>Results</p> <p>Current smokers had higher rates of high and very high psychological distress compared to never smokers (adjusted odds ratio (aOR) = 1.45; 95% CI: 1.24-1.69). Unsuccessful quitters had much higher levels of high to very high levels of psychological distress (16%) than any other group. Moreover, compared to long-term ex-smokers, unsuccessful quitters had a much higher odds of high to very high levels of psychological distress (aOR = 1.73; 95% CI: 1.36-2.21).</p> <p>Conclusion</p> <p>These findings suggest that the significant association between smoking and psychological distress might be partly explained by increased levels of psychological distress among current smokers who made a quit attempt in the last year. This issue needs further study as it has implications for optimising the design of quitting support.</p
The ISOPHOT-MAMBO survey of 3CR radio sources: Further evidence for the unified schemes
We present the complete set of ISOPHOT observations of 3CR radio galaxies and
quasars, which are contained in the ISO Data Archive, providing 75 mid- and
far-infrared spectral energy distributions (SEDs) between 5 and 200 micron. For
28 sources they are supplemented with MAMBO 1.2 mm observations and for 15
sources with new submillimetre data from the SCUBA archive.
We check the orientation-dependent unified scheme, in which the powerful FR2
narrow line galaxies are quasars viewed at high inclination, so that their
nuclei are hidden behind a dust torus intercepting the optical-ultraviolet AGN
radiation and reemitting it in the infrared. We find that (1) both the quasars
and the galaxies show a high mid- to far-infrared luminosity ratio typical for
powerful AGNs and (2) -- when matched in 178 MHz luminosity -- both show the
same ratio of isotropic far-infrared to isotropic 178 MHz lobe power.
Therefore, from our large sample investigated here we find strong evidence for
the orientation-dependent unification of the powerful FR2 galaxies with the
quasars.Comment: 16 pages, 7 figures, 3 tables, accepted by Astronomy & Astrophysic
Synthesis, Characterization and Magnetic Susceptibility of the Heavy Fermion Transition Metal Oxide LiV_{2}O_{4}
The preparative method, characterization and magnetic susceptibility \chi
measurements versus temperature T of the heavy fermion transition metal oxide
LiV_{2}O_{4} are reported in detail. The intrinsic \chi(T) shows a nearly
T-independent behavior below ~ 30 K with a shallow broad maximum at about 16 K,
whereas Curie-Weiss-like behavior is observed above 50-100 K. Field-cooled and
zero-field-cooled magnetization M measurements in applied magnetic fields H =
10 to 100 G from 1.8 to 50 K showed no evidence for spin-glass ordering.
Crystalline electric field theory for an assumed cubic V point group symmetry
is found insufficient to describe the observed temperature variation of the
effective magnetic moment. The Kondo and Coqblin-Schrieffer models do not
describe the magnitude and T dependence of \chi with realistic parameters. In
the high T range, fits of \chi(T) by the predictions of high temperature series
expansion calculations provide estimates of the V-V antiferromagnetic exchange
coupling constant J/k_{B} ~ 20 K, g-factor g ~ 2 and the T-independent
susceptibility. Other possible models to describe the \chi(T) are discussed.
The paramagnetic impurities in the samples were characterized using isothermal
M(H) measurements with 0 < H <= 5.5 Tesla at 2 to 6 K. These impurities are
inferred to have spin S_{imp} ~ 3/2 to 4, g_{imp} ~ 2 and molar concentrations
of 0.01 to 0.8 %, depending on the sample.Comment: 19 typeset RevTeX pages, 16 eps figures included, uses epsf; to be
published in Phys. Rev.
Damage to insula abolishes cognitive distortions during simulated gambling.
This is the accepted version of an article originally published in PNAS. The version of record is available at http://www.pnas.org/content/early/2014/04/02/1322295111.Gambling is a naturalistic example of risky decision-making. During gambling, players typically display an array of cognitive biases that create a distorted expectancy of winning. This study investigated brain regions underpinning gambling-related cognitive distortions, contrasting patients with focal brain lesions to the ventromedial prefrontal cortex (vmPFC), insula, or amygdala ("target patients") against healthy comparison participants and lesion comparison patients (i.e., with lesions that spare the target regions). A slot machine task was used to deliver near-miss outcomes (i.e., nonwins that fall spatially close to a jackpot), and a roulette game was used to examine the gambler's fallacy (color decisions following outcome runs). Comparison groups displayed a heightened motivation to play following near misses (compared with full misses), and manifested a classic gambler's fallacy effect. Both effects were also observed in patients with vmPFC and amygdala damage, but were absent in patients with insula damage. Our findings indicate that the distorted cognitive processing of near-miss outcomes and event sequences may be ordinarily supported by the recruitment of the insula. Interventions to reduce insula reactivity could show promise in the treatment of disordered gambling.LC was supported by a grant from the Medical Research Council (UK) (G1100554). BS was supported
by a PhD studentship from the Medical Research Council. AB and DT, as well as the lesion patient
research, were supported by grants from the National Institute of Health, namely the National
Institute of Neurological Disorders and Stroke [P01 NS19632], and by the National Institute on Drug
Abuse [R01 DA023051, R01 DA022549]
Smoking and mental illness: results from population surveys in Australia and the United States
<p>Abstract</p> <p>Background</p> <p>Smoking has been associated with a range of mental disorders including schizophrenia, anxiety disorders and depression. People with mental illness have high rates of morbidity and mortality from smoking related illnesses such as cardiovascular disease, respiratory diseases and cancer. As many people who meet diagnostic criteria for mental disorders do not seek treatment for these conditions, we sought to investigate the relationship between mental illness and smoking in recent population-wide surveys.</p> <p>Methods</p> <p>Survey data from the US National Comorbidity Survey-Replication conducted in 2001β2003, the 2007 Australian Survey of Mental Health and Wellbeing, and the 2007 US National Health Interview Survey were used to investigate the relationship between current smoking, ICD-10 mental disorders and non-specific psychological distress. Population weighted estimates of smoking rates by disorder, and mental disorder rates by smoking status were calculated.</p> <p>Results</p> <p>In both the US and Australia, adults who met ICD-10 criteria for mental disorders in the 12 months prior to the survey smoked at almost twice the rate of adults without mental disorders. While approximately 20% of the adult population had 12-month mental disorders, among adult smokers approximately one-third had a 12-month mental disorder β 31.7% in the US (95% CI: 29.5%β33.8%) and 32.4% in Australia (95% CI: 29.5%β35.3%). Female smokers had higher rates of mental disorders than male smokers, and younger smokers had considerably higher rates than older smokers. The majority of mentally ill smokers were not in contact with mental health services, but their rate of smoking was not different from that of mentally ill smokers who had accessed services for their mental health problem. Smokers with high levels of psychological distress smoked a higher average number of cigarettes per day.</p> <p>Conclusion</p> <p>Mental illness is associated with both higher rates of smoking and higher levels of smoking among smokers. Further, a significant proportion of smokers have mental illness. Strategies that address smoking in mental illness, and mental illness among smokers would seem to be important directions for tobacco control. As the majority of smokers with mental illness are not in contact with mental health services for their condition, strategies to address mental illness should be included as part of population health-based mental health and tobacco control efforts.</p
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Seeking and accessing professional support for child anxiety in a community sample
There is a lack of current data on help-seeking, and barriers to accessing professional support for child anxiety disorders. This study aimed to provide current data on the frequency and type of parental help-seeking, professional support received, and parent-reported barriers/facilitators in the context of child anxiety, and to explore factors associated with help-seeking, and parent-reported barriers among help-seekers and non help-seekers. We conducted aΒ survey of help-seeking in parents of 222 children (aged 7-11) with elevated anxiety symptoms identified through screening in schools, 138 children of whom met diagnostic criteria for an anxiety disorder. Almost two-thirds (64.5%) of parents of children with an anxiety disorder reported seeking help from a professional; in 38.4% of cases parents reported that their child had received support from a professional to help manage and overcome their anxiety difficulties, andβ<β3% had received evidence-based treatment (CBT). Frequently reported parental barriers related to difficulties differentiating between developmentally appropriate and clinically significant anxiety, a lack of help-seeking knowledge, perceived negative consequences of help-seeking, and limited service provision. Non-help seekers were more likely than help seekers to report barriers related to thinking a child's anxiety may improve without professional support, and the absence of professional recognition. Findings identify the need for (i) tools for parents and primary school staff to help identify children who may benefit from professional support to overcome difficulties with anxiety; and (ii) increased evidence-based provision for child anxiety disorders, including delivery within schools and direct support for parents
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