684 research outputs found
Extreme values and fat tails of multifractal fluctuations
In this paper we discuss the problem of the estimation of extreme event
occurrence probability for data drawn from some multifractal process. We also
study the heavy (power-law) tail behavior of probability density function
associated with such data. We show that because of strong correlations,
standard extreme value approach is not valid and classical tail exponent
estimators should be interpreted cautiously. Extreme statistics associated with
multifractal random processes turn out to be characterized by non
self-averaging properties. Our considerations rely upon some analogy between
random multiplicative cascades and the physics of disordered systems and also
on recent mathematical results about the so-called multifractal formalism.
Applied to financial time series, our findings allow us to propose an unified
framemork that accounts for the observed multiscaling properties of return
fluctuations, the volatility clustering phenomenon and the observed ``inverse
cubic law'' of the return pdf tails
Burnout in the ICU : potential consequences for staff and patient well-being
Peer reviewedAuthor versio
NICMOS Imaging of Infrared-Luminous Galaxies
We present near-infrared images obtained with the HST NICMOS camera for a
sample of 9 luminous (LIGs: L_IR (8-1000 microns) >~ 10^11 L_sun) and 15
ultra-luminous (ULIGS: L_IR >~ 10^12 L_sun) infrared galaxies. The sample
includes representative systems classified as warm (f_25/f_60 > 0.2) and cold
(f_25/f_60 <~ 0.2) based on the mid-infrared colors and systems with nuclear
emission lines classified as HII (i.e. starburst), QSO, Seyfert and LINER. The
morphologies of the sample galaxies are diverse and provide further support for
the idea that they are created by the collision or interactions of spiral
galaxies. Although no new nuclei are seen in the NICMOS images, the NICMOS
images do reveal new spiral structures, bridges, and circumnuclear star
clusters...Comment: LaTex, 27 pages with 14 gif and 4 jpg figures, AJ, in press, contour
figures of the NICMOS images can be viewed at
http://nedwww.ipac.caltech.edu/level5/Scoville/frames.htm
Polynitroxyl Albumin and Albumin Therapy After Pediatric Asphyxial Cardia Arrest: Effects on Cerebral Blood Flow and Neurologic Outcome
Postresuscitation cerebral blood flow (CBF) disturbances and generation of reactive oxygen species likely contribute to impaired neurologic outcome after pediatric cardiac arrest (CA). Hence, we determined the effects of the antioxidant colloid polynitroxyl albumin (PNA) versus albumin or normal saline (NS) on CBF and neurologic outcome after asphyxial CA in immature rats. We induced asphyxia for 9 minutes in male and female postnatal day 16 to 18 rats randomized to receive PNA, albumin, or NS at resuscitation from CA or sham surgery. Regional CBF was measured serially from 5 to 150 minutes after resuscitation by arterial spin-labeled magnetic resonance imaging. We assessed motor function (beam balance and inclined plane), spatial memory retention (water maze), and hippocampal neuronal survival. Polynitroxyl albumin reduced early hyperemia seen 5 minutes after CA. In contrast, albumin markedly increased and prolonged hyperemia. In the delayed period after resuscitation (90 to 150 minutes), CBF was comparable among groups. Both PNA- and albumin-treated rats performed better in the water maze versus NS after CA. This benefit was observed only in males. Hippocampal neuron survival was similar between injury groups. Treatment of immature rats with PNA or albumin resulted in divergent acute changes in CBF, but both improved spatial memory retention in males after asphyxial CA
Impact of integrated district level mental health care on clinical and functioning outcomes of people with depression and alcohol use disorder in Nepal: a non-randomised controlled study
Abstract
Background
Integration of mental health services into primary healthcare is proliferating in low-resource countries. We aimed to evaluate the impact of different compositions of primary care mental health services for depression and alcohol use disorder (AUD), when compared to usual primary care services.
Methods
We conducted a non-randomized controlled study in rural Nepal. We compared treatment outcomes among patients screening positive and receiving: (a) primary care mental health services without a psychological treatment component (TG); (b) the same services including a psychological treatment (TG + P); and (c) primary care treatment as usual (TAU). Primary outcomes included change in depression and AUD symptoms, as well as disability. Disability was measured using the 12-item WHO Disability Assessment Schedule. Symptom severity was assessed using the 9-item Patient Health Questionnaire for depression, the 10-item Alcohol Use Disorders Identification Test for AUD. We used negative binomial regression models for the analysis.
Results
For depression, when combining both treatment groups (TG, n = 77 and TG + P, n = 60) compared to TAU (n = 72), there were no significant improvements. When only comparing the psychological treatment group (TG + P) with TAU, there were significant improvements for symptoms and disability (aβ = − 2.64; 95%CI − 4.55 to − 0.74, p = 0.007; aβ = − 12.20; 95%CI − 19.79 to − 4.62; p = 0.002, respectively). For AUD, when combining both treatment groups (TG, n = 92 and TG + P, n = 80) compared to TAU (n = 57), there were significant improvements in AUD symptoms and disability (aβ = − 15.13; 95%CI − 18.63 to − 11.63, p < 0.001; aβ = − 9.26; 95%CI − 16.41 to − 2.12, p = 0.011; respectively). For AUD, there were no differences between TG and TG + P. Patients’ perceptions of health workers’ skills in common psychological factors were associated with improvement in depression patient outcomes (β = − 0.36; 95%CI − 0.55 to − 0.18; p < 0.001) but not for AUD patients.
Conclusion
Primary care mental health services for depression may only be effective when psychological treatments are included. Health workers’ competencies as perceived by patients may be an important indicator for treatment effect. AUD treatment in primary care appears to be beneficial even without additional psychological services
Inhomogeneous superconductivity in organic conductors: role of disorder and magnetic field
Several experimental studies have shown the presence of spatially
inhomogeneous phase coexistence of superconducting and non superconducting
domains in low dimensional organic superconductors. The superconducting
properties of these systems are found to be strongly dependent on the amount of
disorder introduced in the sample regardless of its origin. The suppression of
the superconducting transition temperature shows clear discrepancy with
the result expected from the Abrikosov-Gor'kov law giving the behavior of
with impurities. Based on the time dependent Ginzburg-Landau theory, we derive
a model to account for the striking feature of in organic superconductors
for different types of disorder by considering the segregated texture of the
system. We show that the calculated quantitatively agrees with
experiments. We also focus on the role of superconducting fluctuations on the
upper critical fields of layered superconductors showing slab
structure where superconducting domains are sandwiched by non-superconducting
regions. We found that may be strongly enhanced by such fluctuations.Comment: to appear in Journal of Physics: Condensed Matte
Sharks of the order Carcharhiniformes from the British Coniacian, Santonian and Campanian (Upper Cretaceous).
Bulk sampling of phosphate-rich horizons within the British Coniacian to Campanian (Upper Cretaceous) yielded very large samples of shark and ray teeth. All of these samples yielded teeth of diverse members of the Carcharhiniformes, which commonly dominate the fauna. The following species are recorded and described: Pseudoscyliorhinus reussi (Herman, 1977) comb. nov., Crassescyliorhinus germanicus (Herman, 1982) gen. nov., Scyliorhinus elongatus (Davis, 1887), Scyliorhinus brumarivulensis sp. nov., ? Palaeoscyllium sp., Prohaploblepharus riegrafi (Müller, 1989) gen. nov., ? Cretascyliorhinus sp., Scyliorhinidae inc. sedis 1, Scyliorhinidae inc. sedis 2, Pteroscyllium hermani sp. nov., Protoscyliorhinus sp., Leptocharias cretaceus sp. nov., Palaeogaleus havreensis Herman, 1977, Paratriakis subserratus sp. nov., Paratriakis tenuis sp. nov., Paratriakis sp. indet. and ? Loxodon sp. Taxa belonging to the families ?Proscylliidae, Leptochariidae, and Carcharhinidae are described from the Cretaceous for the first time. The evolutionary and palaeoecological implications of these newly recognised faunas are discussed
New data on the systematics and interrelationships of sawfishes (Elasmobranchii, Batoidea, Pristiformes)
New characters based on the arrangement and morphology of dermal denticles
show that sawfishes can be divided into two distinctive groups. The first
group, comprising the knifetooth sawfish Anoxypristis cuspidata, is
characterized by tricuspid denticles variably located on both dorsal and
ventral parts of the body. The second group is represented by species of the
genus Pristis, showing an uniform and homogenous dermal covering of
monocuspidate denticles on both dorsal and ventral sides of the body and within
the buccopharyngeal cavity. Pristis is further divided into two subgroups: the
first comprises species with denticles lacking any keels and furrows (the
smalltooth sawfish Pristis pectinata, the green sawfish Pristis zijsron and the
dwarf sawfish Pristis clavata); the second comprises species with denticles
presenting keels and furrows well differentiated on their anterior part (the
common sawfish Pristis pristis, the largetooth sawfish Pristis perotteti and
the greattooth sawfish Pristis microdon). This investigation of the dermal
covering provides results which agree with studies that separate the same two
species groups of Pristis on the basis of other morphological data
- …