2,853 research outputs found
Derived equivalence and non-vanishing loci
The paper proposes and motivates a conjecture on the invariance of
cohomological support loci under derived equivalence. It contains a proof in
the case of surfaces, and explains further developments and consequences.Comment: 9 pages; to appear in the Clay volume in honor of Joe Harris' 60th
birthda
Interaction between the BDNF gene Val/66/Met polymorphism and morning cortisol levels as a predictor of depression in adult women.
BACKGROUND: Common genetic variants, such as the brain-derived neurotrophic factor (BDNF) Val/66/Met polymorphism (rs6265), are known to interact with environmental factors such as early adversity to increase the risk of subsequent major depression. Much less is known about how they interact with individual differences in cortisol, although these also represent a risk for major depression. AIMS: To determine whether this BDNF variant moderated the risk represented by higher levels of morning salivary cortisol in adult women. METHOD: We recruited 279 premenopausal women who were at high risk of major depressive disorder because of either negative self-evaluation, unsupportive core relationship or chronic subclinical symptoms of depression or anxiety. Morning salivary cortisol was measured daily for up to 10 days at entry. Participants were followed up for about 12 months by telephone calls at 3-4 monthly intervals. Major depression and severe life events were assessed through interviews at baseline and follow-up; DNA was obtained from the saliva. RESULTS: There were 53 onsets (19%) of depressive episodes during follow-up. There was a significant U-shaped relationship between adjusted morning cortisol levels at baseline and the probability of depression onset during follow-up. In total, 51% experienced at least one severe life event/difficulty, and this strongly predicted subsequent onsets of depressive episodes. The BDNF Val/66/Met genotype was not directly associated with onsets of depression or with cortisol levels, but there was significant interaction between Val/66/Met and cortisol: the association between baseline cortisol and depression was limited to those with the Val/66/Val variant. There was no interaction between life events and either this BDNF polymorphism or cortisol levels. CONCLUSIONS: Morning salivary cortisol interacts with the BDNF Val/66/Met polymorphism in predicting new depressive episodes. This paper adds to the evidence that single gene polymorphisms interact with endogenous factors to predict depression.This is the published version. It has been published by the Royal College of Psychiatrists in The British Journal of Psychiartry and can be found here: http://bjp.rcpsych.org/content/201/4/313.full.pdf+html. Information about the licence this work falls under can be found here: http://www.rcpsych.ac.uk/pdf/Wellcome%20Trust%20licence.pdf
Tower of coverings of quasi-projective varieties
The main goal of this article is to relate asymptotic geometric properties on
a tower of coverings of a non-compact K\"ahler manifold of finite volume with
reasonable geometric assumptions to its universal covering. Applicable examples
include moduli spaces of hyperbolic punctured Riemann surfaces and Hermitian
locally symmetric spaces of finite volume
Applying the Coulomb Failure Function with an optimally oriented plane to the 2008 Mw 7.9 Wenchuan earthquake triggering
The Coulomb failure function (CFF) quantitatively describes static stress changes in secondary faults near the source fault of an earthquake. CFF can be employed to monitor how static stress transfers and then shed some light on the probability of successive events occurring around a source fault. In this paper we focus on the CFF and particularly on optimally oriented planes. We present a unified model to determine an optimally oriented plane and its corresponding Coulomb stress, then apply the model to the 2003 Mw 6.6 Bam (Iran) earthquake and the 2008 Mw 7.9 Wenchuan (China) earthquake, thereby checking its effectiveness. Our results show that spatial correlation between positive Coulomb stress changes and aftershocks are, for the 2003 Bam earthquake, 47.06% when elastic Coulomb stress changes are resolved on uniform planes and 87.53% when these are resolved on optimally oriented planes at depth; for the 2008 Wenchuan earthquake the correlations are 45.68% and 58.20%, respectively. It is recommended that account be taken of optimally oriented planes when drawing a Coulomb stress map for analyzing earthquake triggering effects
Enhanced absorption Hanle effect on the Fg=F->Fe=F+1 closed transitions
We analyse the Hanle effect on a closed transition. Two
configurations are examined, for linear- and circular-polarized laser
radiation, with the applied magnetic field collinear to the laser light
wavevector. We describe the peculiarities of the Hanle signal for
linearly-polarized laser excitation, characterized by narrow bright resonances
at low laser intensities. The mechanism behind this effect is identified, and
numerical solutions for the optical Bloch equations are presented for different
transitions.Comment: to be published in J. Opt. B, special issue on Quantum Coherence and
Entanglement (February 2001
Melaena with Peutz-Jeghers syndrome: a case report
Introduction: Peutz-Jeghers syndrome (PJS) is a rare familial disorder characterised by mucocutaneous pigmentation, gastrointestinal and extragastrointestinal hamartomatous polyps and an increased risk of malignancy. Peutz-Jeghers polyps in the bowel may result in intussusception. This complication usually manifests with abdominal pain and signs of intestinal obstruction.
Case Presentation: We report the case of a 24-year-old Caucasian male who presented with melaena. Pigmentation of the buccal mucosa was noted but he was pain-free and examination of the abdomen was unremarkable. Upper gastrointestinal endoscopy revealed multiple polyps. An urgent abdominal computed tomography (CT) scan revealed multiple small bowel intussusceptions. Laparotomy was undertaken on our patient, reducing the intussusceptions and removing the polyps by enterotomies. Bowel resection was not needed.
Conclusion: Melaena in PJS needs to be urgently investigated through a CT scan even in the absence of abdominal pain and when clinical examination of the abdomen shows normal findings. Although rare, the underlying cause could be intussusception, which if missed could result in grave consequences
Quantum Zeno Effect and Light-Dark Periods for a Single Atom
The quantum Zeno effect (QZE) predicts a slow-down of the time development of
a system under rapidly repeated ideal measurements, and experimentally this was
tested for an ensemble of atoms using short laser pulses for non-selective
state measurements. Here we consider such pulses for selective measurements on
a single system. Each probe pulse will cause a burst of fluorescence or no
fluorescence. If the probe pulses were strictly ideal measurements, the QZE
would predict periods of fluorescence bursts alternating with periods of no
fluorescence (light and dark periods) which would become longer and longer with
increasing frequency of the measurements. The non-ideal character of the
measurements is taken into account by incorporating the laser pulses in the
interaction, and this is used to determine the corrections to the ideal case.
In the limit, when the time between the laser pulses goes to zero, no freezing
occurs but instead we show convergence to the familiar macroscopic light and
dark periods of the continuously driven Dehmelt system. An experiment of this
type should be feasible for a single atom or ion in a trapComment: 16 pages, LaTeX, a4.sty; to appear in J. Phys.
Anti-inflammatory effects of antidepressant and atypical antipsychotic medication for the treatment of major depression and comorbid arthritis: a case report
Extent: 4p.Introduction: This case report describes the effects of psychotropic treatment, quetiapine in particular, on systemic inflammation, pain, general functioning and major depression in the treatment of a woman with arthritis. Case presentation: A 49-year-old Caucasian Australian woman with arthritis, pain and depression was treated with a course of escitalopram, mirtazapine and quetiapine. Pain levels, general functioning and degree of depressive symptoms were evaluated with a visual analogue scale. Systemic inflammation had been assessed by C-reactive protein serum levels since 2003. C-reactive protein levels, physical pain, symptoms of arthritis and depression decreased significantly during the past 12 months of treatment with quetiapine, while treatment with selective serotonin reuptake inhibitors and mirtazapine remained the same. Conclusions: We suggest that the treatment particularly with quetiapine may have anti-inflammatory effects in arthritis and comorbid major depression, which eventually led to a remission of pain and depression and to normal general function.Bernhard T Baune, Harris Eyr
- …