2,319 research outputs found
Paradoxical reactions and immune reconstitution inflammatory syndrome in tuberculosis
The coalescence of the HIV-1 and tuberculosis (TB) epidemics in Sub-Saharan Africa has had a significant
and negative impact on global health. The availability of effective antimicrobial treatment for both HIV-1
(in the form of highly active antiretroviral therapy (HAART)) and TB (with antimycobacterial agents) has
the potential to mitigate the associated morbidity and mortality. However, the use of both HAART and
antimycobacterial therapy is associated with the development of inflammatory paradoxical syndromes
after commencement of therapy. These include paradoxical reactions (PR) and immune reconstitution
inflammatory syndromes (IRIS), conditions that complicate mycobacterial disease in HIV seronegative
and seropositive individuals. Here, we discuss case definitions for PR and IRIS, and explore how advances
in identifying the risk factors and immunopathogenesis ofthese conditions informs our understanding of
their shared underlying pathogenesis. We propose that both PR and IRIS are characterized by the
triggering of exaggerated inflammation in a setting of immunocompromise and antigen loading, via the
reversal of immunosuppression by HAART and/or antimycobacterials. Further understanding of the
molecular basis of this pathogenesis may pave the way for effective immunotherapies for the treatment
of PR and IRIS
Quantum networks reveal quantum nonlocality
The results of local measurements on some composite quantum systems cannot be
reproduced classically. This impossibility, known as quantum nonlocality,
represents a milestone in the foundations of quantum theory. Quantum
nonlocality is also a valuable resource for information processing tasks, e.g.
quantum communication, quantum key distribution, quantum state estimation, or
randomness extraction. Still, deciding if a quantum state is nonlocal remains a
challenging problem. Here we introduce a novel approach to this question: we
study the nonlocal properties of quantum states when distributed and measured
in networks. Using our framework, we show how any one-way entanglement
distillable state leads to nonlocal correlations. Then, we prove that
nonlocality is a non-additive resource, which can be activated. There exist
states, local at the single-copy level, that become nonlocal when taking
several copies of it. Our results imply that the nonlocality of quantum states
strongly depends on the measurement context.Comment: 4 + 3 pages, 4 figure
Efficacy of an intensive outpatient rehabilitation program in alcoholism: Predictors of outcome 6 months after treatment
Treatment of alcohol-dependent patients was primarily focused on inpatient settings in the past decades. The efficacy of these treatment programs has been evaluated in several studies and proven to be sufficient. However, with regard to the increasing costs in public healthcare systems, questions about alternative treatment strategies have been raised. Meanwhile, there is growing evidence that outpatient treatment might be comparably effective as inpatient treatment, at least for subgroups of alcohol dependents. On that background, the present study aimed to evaluate the efficacy of a high-structured outpatient treatment program in 103 alcohol-dependent patients. 74 patients (72%) terminated the outpatient treatment regularly. At 6 months' follow-up, 95% patients were successfully located and personally re-interviewed. Analyses revealed that 65 patients (64%) were abstinent at the 6-month follow-up evaluation and 37 patients ( 36%) were judged to be non-abstinent. Pretreatment variables which were found to have a negative impact (non-abstinence) on the 6-month outcome after treatment were a higher severity of alcohol dependence measured by a longer duration of alcohol dependence, a higher number of prior treatments and a stronger alcohol craving (measured by the Obsessive Compulsive Drinking Scale). Further patients with a higher degree of psychopathology measured by the Beck Depression Inventory (depression) and State-Trait Anxiety Inventory (anxiety) relapsed more often. In summary, results of this study indicate a favorable outcome of socially stable alcohol-dependent patients and patients with a lower degree of depression, anxiety and craving in an intensive outpatient rehabilitation program
Electric Field Effects on Graphene Materials
Understanding the effect of electric fields on the physical and chemical
properties of two-dimensional (2D) nanostructures is instrumental in the design
of novel electronic and optoelectronic devices. Several of those properties are
characterized in terms of the dielectric constant which play an important role
on capacitance, conductivity, screening, dielectric losses and refractive
index. Here we review our recent theoretical studies using density functional
calculations including van der Waals interactions on two types of layered
materials of similar two-dimensional molecular geometry but remarkably
different electronic structures, that is, graphene and molybdenum disulphide
(MoS). We focus on such two-dimensional crystals because of they
complementary physical and chemical properties, and the appealing interest to
incorporate them in the next generation of electronic and optoelectronic
devices. We predict that the effective dielectric constant () of
few-layer graphene and MoS is tunable by external electric fields (). We show that at low fields ( V/\AA)
assumes a nearly constant value 4 for both materials, but increases at
higher fields to values that depend on the layer thickness. The thicker the
structure the stronger is the modulation of with the electric
field. Increasing of the external field perpendicular to the layer surface
above a critical value can drive the systems to an unstable state where the
layers are weakly coupled and can be easily separated. The observed dependence
of on the external field is due to charge polarization driven by
the bias, which show several similar characteristics despite of the layer
considered.Comment: Invited book chapter on Exotic Properties of Carbon Nanomatter:
Advances in Physics and Chemistry, Springer Series on Carbon Materials.
Editors: Mihai V. Putz and Ottorino Ori (11 pages, 4 figures, 30 references
Behavioural stress responses predict environmental perception in European sea bass (Dicentrarchus labrax)
Individual variation in the response to environmental challenges depends partly on innate reaction norms, partly on experience-based cognitive/emotional evaluations that individuals make of the situation. The goal of this study was to investigate whether pre-existing differences in behaviour predict the outcome of such assessment of environmental cues, using a conditioned place preference/avoidance (CPP/CPA) paradigm. A comparative vertebrate model (European sea bass, Dicentrarchus labrax) was used, and ninety juvenile individuals were initially screened for behavioural reactivity using a net restraining test. Thereafter each individual was tested in a choice tank using net chasing as aversive stimulus or exposure to familiar conspecifics as appetitive stimulus in the preferred or non preferred side respectively (called hereafter stimulation side). Locomotor behaviour (i.e. time spent, distance travelled and swimming speed in each tank side) of each individual was recorded and analysed with video software. The results showed that fish which were previously exposed to appetitive stimulus increased significantly the time spent on the stimulation side, while aversive stimulus led to a strong decrease in time spent on the stimulation side. Moreover, this study showed clearly that proactive fish were characterised by a stronger preference for the social stimulus and when placed in a putative aversive environment showed a lower physiological stress responses than reactive fish. In conclusion, this study showed for the first time in sea bass, that the CPP/CPA paradigm can be used to assess the valence (positive vs. negative) that fish attribute to different stimuli and that individual behavioural traits is predictive of how stimuli are perceived and thus of the magnitude of preference or avoidance behaviour.European Commission [265957]; Portuguese Fundacao para a Ciencia e Tecnologia (FCT) [FRH/BPD/72952/2010]; FCT [SFRH/BD/80029/2011
Engaging with community researchers for exposure science: lessons learned from a pesticide biomonitoring study
A major challenge in biomonitoring studies with members of the general public is ensuring their continued involvement throughout the necessary length of the research. The paper presents evidence on the use of community researchers, recruited from local study areas, as a mechanism for ensuring effective recruitment and retention of farmer and resident participants for a pesticides biomonitoring study. The evidence presented suggests that community researchers' abilities to build and sustain trusting relationships with participants enhanced the rigour of the study as a result of their on-the-ground responsiveness and flexibility resulting in data collection beyond targets expected
Qubit portrait of the photon-number tomogram and separability of two-mode light states
In view of the photon-number tomograms of two-mode light states, using the
qubit-portrait method for studying the probability distributions with infinite
outputs, the separability and entanglement detection of the states are studied.
Examples of entangled Gaussian state and Schr\"{o}dinger cat state are
discussed.Comment: 20 pages, 6 figures, TeX file, to appear in Journal of Russian Laser
Researc
Nonthermal Emission from Star-Forming Galaxies
The detections of high-energy gamma-ray emission from the nearby starburst
galaxies M82 & NGC253, and other local group galaxies, broaden our knowledge of
star-driven nonthermal processes and phenomena in non-AGN star-forming
galaxies. We review basic aspects of the related processes and their modeling
in starburst galaxies. Since these processes involve both energetic electrons
and protons accelerated by SN shocks, their respective radiative yields can be
used to explore the SN-particle-radiation connection. Specifically, the
relation between SN activity, energetic particles, and their radiative yields,
is assessed through respective measures of the particle energy density in
several star-forming galaxies. The deduced energy densities range from O(0.1)
eV/cm^3 in very quiet environments to O(100) eV/cm^3 in regions with very high
star-formation rates.Comment: 17 pages, 5 figures, to be published in Astrophysics and Space
Science Proceeding
Precision measurement of the Dalitz plot distribution with the KLOE detector
Using fb of data collected with
the KLOE detector at DANE, the Dalitz plot distribution for the decay is studied with the world's largest sample of events. The Dalitz plot density is parametrized as a polynomial
expansion up to cubic terms in the normalized dimensionless variables and
. The experiment is sensitive to all charge conjugation conserving terms of
the expansion, including a term. The statistical uncertainty of all
parameters is improved by a factor two with respect to earlier measurements.Comment: 11 pages, 9 figures, supplement: an ascii tabl
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