2,560 research outputs found
Ion acceleration and anomalous transport in the near wake of a plasma limiter
Ion acceleration and anomalous transport were studied experimentally in the near wake region of an electrically floating disk limiter immersed in two different types of collisionless, supersonically flowing, magnetized plasmas: the first initially quiescent, the second initially turbulent. Ion densities and velocity distributions were obtained using a nonperturbing laser induced fluorescence diagnostic. Large-amplitude, low-frequency turbulence was observed at the obstacle edge and in the wake. Rapid ion and electron configuration space transport and ion velocity space transport were observed. Configuration space and velocity space transport were similar for both quiescent and turbulent plasma-obstacle systems, suggesting that plasma-obstacle effects outweigh the effects of initial plasma turbulence levels
Redefining the effect of salt on thermophilic starter cell viability, culturability and metabolic activity in cheese
peer-reviewedThis study investigated the differential effect of salt concentration in the outside and inside layers of
brine salted cheeses on viability, culturability and enzyme activity of starter bacteria. The high-salt
environment of the outside layer caused a sharp decrease in L. helveticus viability as measured by
traditional plate counts. Remarkably, this was associated with lower release of intracellular enzymes
(LDH), reduced levels of proteolysis and larger membrane integrity as measured by flow cytometry (FC)
following classical Live/Dead staining. FC analysis of light scattering properties highlighted a significant
reduction in size and granularity of the microbiota located in the cheese surface, suggestive of cell
shrinkage and condensation of internal macromolecules probably due to hyperosmotic stress. The
microbiota of the cheese surface were found to experience greater oxidative stress, as measured by FC
analysis of the total levels of reactive oxygen species, compared to that of the interior layer. These results
lead us to postulate that the physiology and health status of the microbiota were significantly different in
the outer and inner layers of the cheese. The hyperosmotic environment of the outer layer resulted in
reduced cell lysis, as measurable by assays based upon membrane integrity, but rather triggered cell
death via mechanisms involving cell shrinkage and ROS-mediated damage of vital intracellular components.
This study challenges the current thinking on how salt controls microbial activity in ripening
cheese, especially in cheeses which are brine salted as local variations in biochemical ripening indices
can differ significantly from the outside to the inside of a ripening cheese
The influence of COMT Val158Met genotype on the character dimension cooperativeness in healthy females
Objectives: Although the Val(158)Met catechol-O-methyltransferase (COMT) gene has been linked with the temperament dimension Novelty Seeking (NS), new insights in this polymorphism might point to a major role for character features as well. Given that individual life experiences may influence Val(158) and Met(158) allele carriers differently it has been suggested that the character trait cooperativeness could be implicated.
Case report: A homogeneous group of eighty right-handed Caucasian healthy female university students were assessed with the TCI and genotyped for the COMT Val(158)Met polymorphism (rs4680). Gene determination showed that eighteen were Val(158) homozygotes, forty-four Val/Met(158) heterozygotes, and eighteen were Met(158) homozygotes. All were within the same age range and never documented to have suffered from any neuropsychiatric illness. Bonferroni corrected non-parametric analyses showed that only for the character scale cooperativeness Val(158) homozygotes displayed significant higher scores when compared to Met(158) homozygotes. No significant differences on cooperativeness scores were found between Val(158) and Val/Met(158) carriers or between Met(158) and Val/Met(158) carriers. No differences were observed for the COMT Val(158) Met polymorphism and the other temperament and character scales.
Conclusions: Our findings support the assumption that the Val(158)Met single nucleotide polymorphism (SNP) influences character traits and not only temperament. Our results add to the notion that Val(158) homozygotes are considered to be helpful and empathic and it suggest that these cooperativeness character traits are related to the dopaminergic system
Adjustable levels of strong turbulence in a positive/negative ion plasma
Positive/negative ion plasmas, composed of Ba+, SF6â, and residual electrons, were observed to display characteristics of strong turbulence.Experiments on the UCI Q machine linked the presence of negative ions (and the depletion of electrons) with large density fluctuations (ÎŽn/nâ1), largeâamplitude, lowâfrequency electrostatic noise (fâ€20 kHz), and rapid transport of ions across magnetic field lines (Dâ„â104 cm2/sec). Ion velocity distributions were heated parallel to and cooled perpendicular to the confining magnetic field. The partial pressure of gaseous SF6 was shown to serve as a regulator of plasma turbulence. Turbulence levels could be smoothly varied from quiescent states (ÎŽn/nâ0.01) to strongly turbulent states (ÎŽn/nâ1)
Quantum thermodynamics of a charged magneto-oscillator coupled to a heat bath
Explicit results for various quantum thermodynamic function (QTF) of a
charged magneto-oscillator coupled to a heat bath at arbitrary temperature are
demonstrated in this paper. Discernible expressions for different QTF in the
two limits of very low and very high temperatures are presented for three
popular heat bath models : Ohmic, single relaxation time and blackbody
radiation. The central result is that the effect of magnetic field turns out to
be important at low temperatures yet crucial at high temperatures. It is
observed that the dissipation parameter, , and the cyclotron frequency,
, affect the decaying or rising behaviour of various QTF in just the
opposite way to each other at low temperatures. In the high temperature regime,
the effect of is much pronounced than that of .Comment: 26 Pages, 18 Figure
The effects of PTSD treatment during pregnancy: systematic review and case study
Background: PTSD in pregnant women is associated with adverse outcomes for mothers and their children. It is unknown whether pregnant women with PTSD, or symptoms of
PTSD, can receive targeted treatment that is safe and effective.
Objective: The purpose of the present paper was to assess the effectiveness and safety of treatment for (symptoms of) PTSD in pregnant women.
Method: A systematic review was conducted in accordance with the PRISMA guidelines in Pubmed, Embase, PsychINFO, and Cochrane. In addition, a case is presented of a pregnant woman with PTSD who received eye-movement desensitization and reprocessing (EMDR) therapy aimed at processing the memories of a previous distressing childbirth.
Results: In total, 13 studies were included, involving eight types of interventions (i.e. trauma-focused cognitive behavioural therapy, exposure therapy, EMDR therapy, interpersonal psychotherapy, explorative therapy, self-hypnosis and relaxation, Survivor Moms
Companion, and Seeking Safety Intervention). In three studies, the traumatic event pertained to a previous childbirth. Five studies reported obstetrical outcomes. After requesting additional information, authors of five studies indicated an absence of serious adverse
events. PTSD symptoms improved in 10 studies. However, most studies carried a high risk of bias. In our case study, a pregnant woman with a PTSD diagnosis based on DSM-5 no longer fulfilled the criteria of PTSD after three sessions of EMDR therapy. She had an uncomplicated pregnancy and delivery.
Conclusion: Despite the fact that case studies as the one presented here report no adverse events, and treatment is likely safe, due to the poor methodological quality of most studies it is impossible to allow inferences on the effects of any particular treatment of PTSD (symptoms) during pregnancy. Yet, given the elevated maternal stress and cortisol levels in pregnant women with PTSD, and the fact that so far no adverse effects on the unborn child have been reported associated with the application of trauma-focused therapy, treatment of PTSD during pregnancy is most likely safe
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