522 research outputs found
Bidentate Lewis Acid Catalyzed Domino Diels-Alder Reaction of Phthalazine for the Synthesis of Bridged Oligocyclic Tetrahydronaphthalenes
A domino process consisting of an inverse and a normal electron-demand Diels-Alder reaction is presented for the formation of bridged tri- and tetracyclic 1,2,3,4-tetrahydronaphthalenes catalyzed by a bidentate Lewis acid. The products were synthesized in a one-pot reaction from commercially available starting materials and contain up to six stereogenic centers. The tetrahydronaphthalenes were isolated as single diastereomers and are derivatives of phenylethylamine, which is well-known as a scaffold of amphetamine or dopamine
Telephone Cognitive-Behavioral Therapy for Subthreshold Depression and Presenteeism in Workplace: A Randomized Controlled Trial
Subthreshold depression is highly prevalent in the general population and causes great loss to society especially in the form of reduced productivity while at work (presenteeism). We developed a highly-structured manualized eight-session cognitive-behavioral program with a focus on subthreshold depression in the workplace and to be administered via telephone by trained psychotherapists (tCBT).We conducted a parallel-group, non-blinded randomized controlled trial of tCBT in addition to the pre-existing Employee Assistance Program (EAP) versus EAP alone among workers with subthreshold depression at a large manufacturing company in Japan. The primary outcomes were depression severity as measured with Beck Depression Inventory-II (BDI-II) and presenteeism as measured with World Health Organization Health and Work Productivity Questionnaire (HPQ). In the course of the trial the follow-up period was shortened in order to increase acceptability of the study.The planned sample size was 108 per arm but the trial was stopped early due to low accrual. Altogether 118 subjects were randomized to tCBT+EAP (n = 58) and to EAP alone (n = 60). The BDI-II scores fell from the mean of 17.3 at baseline to 11.0 in the intervention group and to 15.7 in the control group after 4 months (p<0.001, Effect size = 0.69, 95%CI: 0.32 to 1.05). However, there was no statistically significant decrease in absolute and relative presenteeism (p = 0.44, ES = 0.15, -0.21 to 0.52, and p = 0.50, ES = 0.02, -0.34 to 0.39, respectively).Remote CBT, including tCBT, may provide easy access to quality-assured effective psychotherapy for people in the work force who present with subthreshold depression. Further studies are needed to evaluate the effectiveness of this approach in longer terms. The study was funded by Sekisui Chemicals Co. Ltd.ClinicalTrials.gov NCT00885014
Universality in Bacterial Colonies
The emergent spatial patterns generated by growing bacterial colonies have
been the focus of intense study in physics during the last twenty years. Both
experimental and theoretical investigations have made possible a clear
qualitative picture of the different structures that such colonies can exhibit,
depending on the medium on which they are growing. However, there are
relatively few quantitative descriptions of these patterns. In this paper, we
use a mechanistically detailed simulation framework to measure the scaling
exponents associated with the advancing fronts of bacterial colonies on hard
agar substrata, aiming to discern the universality class to which the system
belongs. We show that the universal behavior exhibited by the colonies can be
much richer than previously reported, and we propose the possibility of up to
four different sub-phases within the medium-to-high nutrient concentration
regime. We hypothesize that the quenched disorder that characterizes one of
these sub-phases is an emergent property of the growth and division of bacteria
competing for limited space and nutrients.Comment: 12 pages, 5 figure
Extinction times in the subcritical stochastic SIS logistic epidemic
Many real epidemics of an infectious disease are not straightforwardly super-
or sub-critical, and the understanding of epidemic models that exhibit such
complexity has been identified as a priority for theoretical work. We provide
insights into the near-critical regime by considering the stochastic SIS
logistic epidemic, a well-known birth-and-death chain used to model the spread
of an epidemic within a population of a given size . We study the behaviour
of the process as the population size tends to infinity. Our results cover
the entire subcritical regime, including the "barely subcritical" regime, where
the recovery rate exceeds the infection rate by an amount that tends to 0 as but more slowly than . We derive precise asymptotics for
the distribution of the extinction time and the total number of cases
throughout the subcritical regime, give a detailed description of the course of
the epidemic, and compare to numerical results for a range of parameter values.
We hypothesise that features of the course of the epidemic will be seen in a
wide class of other epidemic models, and we use real data to provide some
tentative and preliminary support for this theory.Comment: Revised; 34 pages; 6 figure
Observational studies of depression in primary care: what do we know?
<p>Abstract</p> <p>Background</p> <p>We undertook a systematic review of observational studies of depression in primary care to determine 1) the nature and scope of the published studies 2) the methodological quality of the studies; 3) the identified recovery and risk factors for persistent depression and 3) the treatment and health service use patterns among patients.</p> <p>Methods</p> <p>Searches were conducted in MEDLINE, CINAHL and PsycINFO using combinations of topic and keywords, and Medical Subject Headings in MEDLINE, Headings in CINAHL and descriptors in PsycINFO. Searches were limited to adult populations and articles published in English during 1985–2006.</p> <p>Results</p> <p>40 articles from 17 observational cohort studies were identified, most were undertaken in the US or Europe. Studies varied widely in aims and methods making it difficult to meaningfully compare the results. Methodological limitations were common including: selection bias of patients and physicians; small sample sizes (range 35–108 patients at baseline and 20–59 patients at follow-up); and short follow-up times limiting the extent to which these studies can be used to inform our understanding of recovery and relapse among primary care patients with depression. Risk factors for the persistence of depression identified in this review were: severity and chronicity of the depressive episode, the presence of suicidal thoughts, antidepressant use, poorer self-reported quality of life, lower self-reported social support, experiencing key life events, lower education level and unemployment.</p> <p>Conclusion</p> <p>Despite the growing interest in depression being managed as a chronic illness, this review identified only 17 observational studies of depression in primary care, most of which have included small sample sizes and been relatively short-term. Future research should be large enough to investigate risk factors for chronicity and relapse, and should be conducted over a longer time frame.</p
Pattern formation in directional solidification under shear flow. I: Linear stability analysis and basic patterns
An asymptotic interface equation for directional solidification near the
absolute stabiliy limit is extended by a nonlocal term describing a shear flow
parallel to the interface. In the long-wave limit considered, the flow acts
destabilizing on a planar interface. Moreover, linear stability analysis
suggests that the morphology diagram is modified by the flow near the onset of
the Mullins-Sekerka instability. Via numerical analysis, the bifurcation
structure of the system is shown to change. Besides the known hexagonal cells,
structures consisting of stripes arise. Due to its symmetry-breaking
properties, the flow term induces a lateral drift of the whole pattern, once
the instability has become active. The drift velocity is measured numerically
and described analytically in the framework of a linear analysis. At large flow
strength, the linear description breaks down, which is accompanied by a
transition to flow-dominated morphologies, described in a companion paper.
Small and intermediate flows lead to increased order in the lattice structure
of the pattern, facilitating the elimination of defects. Locally oscillating
structures appear closer to the instability threshold with flow than without.Comment: 20 pages, Latex, accepted for Physical Review
Cross-national epidemiology of DSM-IV major depressive episode
Background: Major depression is one of the leading causes of disability worldwide, yet epidemiologic data are not available for many countries, particularly low- to middle-income countries. In this paper, we present data on the prevalence, impairment and demographic correlates of depression from 18 high and low-to middle-income countries in the World Mental Health Survey Initiative. Methods: Major depressive episodes (MDE) as defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DMS-IV) were evaluated in face-to-face interviews using the World Health Organization Composite International Diagnostic Interview (CIDI). Data from 18 countries were analyzed in this report (n = 89,037). All countries surveyed representative, population-based samples of adults. Results: The average lifetime and 12-month prevalence estimates of DSM-IV MDE were 14.6% and 5.5% in the ten high-income and 11.1% and 5.9% in the eight low- to middle-income countries. The average age of onset ascertained retrospectively was 25.7 in the high-income and 24.0 in low- to middle-income countries. Functional impairment was associated with recency of MDE. The female: male ratio was about 2: 1. In high-income countries, younger age was associated with higher 12-month prevalence; by contrast, in several low-to middle-income countries, older age was associated with greater likelihood of MDE. The strongest demographic correlate in high-income countries was being separated from a partner, and in low- to middle-income countries, was being divorced or widowed. Conclusions: MDE is a significant public-health concern across all regions of the world and is strongly linked to social conditions. Future research is needed to investigate the combination of demographic risk factors that are most strongly associated with MDE in the specific countries included in the WMH.(NIH/NIMH) United States National Institute of Mental Health[R01MH070884]John D. and Catherine T. MacArthur FoundationPfizer FoundationUSA Public Health Service[R13-MH066849]USA Public Health Service[R01-MH069864]USA Public Health Service[R01 DA016558](NIH) Fogarty International Center[FIRCA R03-TW006481]PAHO Pan American Health OrganizationEli Lilly & Company FoundationOrtho-McNeil Pharmaceutical, Inc.GlaxoSmithKlineSanofi-AventisBristol-Myers SquibbState of Brazil Research Foundation (FAPESP)[03/00204-3]Ministry of Social ProtectionEuropean Commission[QLG5-1999-01042]European Commission[SANCO 2004123]Piedmont Region (Italy)Fondo de Investigacion Sanitaria, Instituto de Salud Carlos III, Spain[FIS 00/0028]Spanish Ministerio de Ciencia y Tecnologia[SAF 2000-158-CE]Departament de Salut, Generalitat de Catalunya, SpainInstituto de Salud Carlos III[CIBER CB06/02/0046]Instituto de Salud Carlos III[RETICS RD06/0011 REM-TAP]Government of IndiaWHOMinistry of HealthIsrael National Institute for Health Policy and Health Services ResearchNational Insurance Institute of IsraelJapan Ministry of Health, Labour and Welfare[H13-Shogai-023]Japan Ministry of Health, Labour and Welfare[H14-Tokubetsu-026]Japan Ministry of Health, Labour and Welfare[H16-Kokoro-013]Lebanese Ministry of Public HealthWHO (Lebanon)(NIH) Fogarty International, anonymous private donations to IDRAAC, LebanonJanssen CilagEli LillyRocheNovartisNational Institute of Psychiatry Ramon de la Fuente[INPRFMDIES 4280]CNPq National Council on Science and Technology[CONACyT-G30544-H]PanAmerican Health Organization (PAHO)New Zealand Ministry of Health, Alcohol Advisory CouncilHealth Research Council(NIH/NIMH) USA National Institute of Mental Health[R01-MH059575](NIH/NIMH) USA National Institute of Mental Health[RO1-MH61905]National Institute of Drug AbuseSouth African Department of HealthUniversity of MichiganNational Institute of Mental Health (NIH/NIMH)[U01-MH60220]National Institute of Drug Abuse (NIDA)Substance Abuse and Mental Health Services Administration (SAMHSA)Robert Wood Johnson Foundation (RWJF)[044708]John W. Alden TrustsAnalysis Group Inc.Eli Lilly CompanyEPI-QJohnson & Johnson PharmaceuticalsOrtho-McNeil Janssen Scientific AffairsPfizer Inc.Shire USA, Inc
The -essence scalar field in the context of Supernova Ia Observations
A -essence scalar field model having (non canonical) Lagrangian of the
form where
with constant is shown to be consistent with luminosity
distance-redshift data observed for type Ia Supernova. For constant ,
satisfies a scaling relation which is used to set up a differential
equation involving the Hubble parameter , the scale factor and the
-essence field . and are extracted from SNe Ia data and using
the differential equation the time dependence of the field is found to
be: . The constants
have been determined. The time dependence is similar to that of the
quintessence scalar field (having canonical kinetic energy) responsible for
homogeneous inflation. Furthermore, the scaling relation and the obtained time
dependence of the field is used to determine the -dependence of the
function .Comment: 8 pages, 5 figures, Late
Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
We report on work to increase the number of well-measured Type Ia supernovae
(SNe Ia) at high redshifts. Light curves, including high signal-to-noise HST
data, and spectra of six SNe Ia that were discovered during 2001 are presented.
Additionally, for the two SNe with z>1, we present ground-based J-band
photometry from Gemini and the VLT. These are among the most distant SNe Ia for
which ground based near-IR observations have been obtained. We add these six
SNe Ia together with other data sets that have recently become available in the
literature to the Union compilation (Kowalski et al. 2008). We have made a
number of refinements to the Union analysis chain, the most important ones
being the refitting of all light curves with the SALT2 fitter and an improved
handling of systematic errors. We call this new compilation, consisting of 557
supernovae, the Union2 compilation. The flat concordance LambdaCDM model
remains an excellent fit to the Union2 data with the best fit constant equation
of state parameter w=-0.997^{+0.050}_{-0.054} (stat) ^{+0.077}_{-0.082}
(stat+sys\ together) for a flat universe, or w=-1.035^{+0.055}_{-0.059}
(stat)^{+0.093}_{-0.097} (stat+sys together) with curvature. We also present
improved constraints on w(z). While no significant change in w with redshift is
detected, there is still considerable room for evolution in w. The strength of
the constraints depend strongly on redshift. In particular, at z > 1, the
existence and nature of dark energy are only weakly constrained by the data.Comment: 33 pages, 18 figures; accepted for publication in Astrophysical
Journal. For data tables, code for cosmological analysis and full-resolution
figures, see http://supernova.lbl.gov/Union
Roles and practices of general practitioners and psychiatrists in management of depression in the community
BACKGROUND: Little is known about depressed patients' profiles and how they are managed. The aim of the study is to compare GPs and psychiatrists for 1°) sociodemographic and clinical profile of their patients considered as depressed 2°) patterns of care provision. METHODS: The study design is an observational cross-sectional study on a random sample of GPs and psychiatrists working in France. Consecutive inclusion of patients seen in consultation considered as depressed by the physician. GPs enrolled 6,104 and psychiatrists 1,433 patients. Data collected: sociodemographics, psychiatric profile, environmental risk factors of depression and treatment. All clinical data were collected by participating physicians; there was no direct independent clinical assessment of patients to check the diagnosis of depressive disorder. RESULTS: Compared to patients identified as depressed by GPs, those identified by psychiatrists were younger, more often urban (10.5% v 5.4% – OR = 2.4), educated (42.4% v 25.4% – OR = 3.9), met DSM-IV criteria for depression (94.6% v 85.6% – OR = 2.9), had been hospitalized for depression (26.1% v 15.6% – OR = 2.0) and were younger at onset of depressive problems (all adjusted p < .001). No difference was found for psychiatric and somatic comorbidity, suicide attempt and severity of current depression. Compared to GPs, psychiatrists more often prescribed tricyclics and very novel antidepressants (7.8% v 2.3% OR = 5.0 and 6.8% v 3.0% OR = 3.8) with longer duration of antidepressant treatment. GPs' patients received more "non-conventional" treatment (8.8% v 2.4% OR = 0.3) and less psychotherapy (72.2% v 89.1% OR = 3.1) (all adjusted p < .001). CONCLUSION: Differences between patients mainly concerned educational level and area of residence with few differences regarding clinical profile. Differences between practices of GPs and psychiatrists appear to reflect more the organization of the French care system than the competence of providers
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