21 research outputs found
Stability of Satellite Planes in M31 II: Effects of the Dark Subhalo Population
The planar arrangement of nearly half the satellite galaxies of M31 has been
a source of mystery and speculation since it was discovered. With a growing
number of other host galaxies showing these satellite galaxy planes, their
stability and longevity have become central to the debate on whether the
presence of satellite planes are a natural consequence of prevailing
cosmological models, or represent a challenge. Given the dependence of their
stability on host halo shape, we look into how a galaxy plane's dark matter
environment influences its longevity. An increased number of dark matter
subhalos results in increased interactions that hasten the deterioration of an
already-formed plane of satellite galaxies in spherical dark halos. The role of
total dark matter mass fraction held in subhalos in dispersing a plane of
galaxies present non trivial effects on plane longevity as well. But any
misalignments of plane inclines to major axes of flattened dark matter halos
lead to their lifetimes being reduced to < 3 Gyrs. Distributing > 40% of total
dark mass in subhalos in the overall dark matter distribution results in a
plane of satellite galaxies that is prone to change through the 5 Gyr
integration time period.Comment: 11 pages, 9 figures, accepted to MNRAS September 22 201
White Matter Structure in Youth With Behavioral and Emotional Dysregulation Disorders: A Probabilistic Tractographic Study
Psychiatric disorders in youth characterized by behavioral and emotional dysregulation are often comorbid and difficult to distinguish. An alternative approach to conceptualizing these disorders is to move toward a diagnostic system based on underlying pathophysiologic processes that may cut across conventionally defined diagnoses. Neuroimaging techniques have potentials for the identification of these processes
Erythritol production from raw glycerol by Yarrowia lipolytica Wratislavia K1 yeast in a membrane bioreactor
Reaktor membranowy z ciągłą recyrkulacją komórek wykorzystano do ciągłej produkcji erytrytolu z glicerolu odpadowego przez drożdże Yarrowia lipolytica Wratislavia K1. Hodowle produkcyjne oprowadzono przy szybkości rozcieńczania D = 0,007 h-1 w podłożu zawierającym 100, 150 lub 200 g/L glicerolu. Stwierdzono, że wzrost stężenia substratu w podłożu hodowlanym powodował wzrost stężenia erytrytolu (26,5÷56,8 g/L) oraz wzrost szybkości objętościowej produkcji (0,20÷0,28 g×L-1h-1). Natomiast wydajność procesu produkcji erytrytolu kształtowała się w granicach od 0,21 g/g do 0,30 g/g.The production of erythritol from crude glycerol by yeast Yarrowia lipolytica Wratislavia K1 in a membrane reactor with continuous yeasts recycling in the microfiltration module was examined. The yeast was cultured in media containing 100, 150 or 200 g/L crude glycerol at the dilution of 0.007 h-1. The increase of crude glycerol concentration caused the increase of erythritol concentration (26,5÷56,8 g/L) and the increase of volumetric rate (0,20÷0,28 g×L-1h-1) of erythritol production. The yield of the process ranged from 0,21 g/g to 0,30 g/g
Validation of the Polish Problematic Tinder Use Scale and Its Relationship with Safe Sex Behaviors.
Online dating is a common phenomenon. The manageability and access of the application allows people to quickly reach many potential partners, which can increase risky sexual behaviors. The Problematic Tinder Use Scale (PTUS) was developed and validated in a Polish population by analyzing the reliability, validity, and factor structure of the responses given by Polish-speaking participants.
Two samples of adult Tinder users were recruited online. The first study aimed to perform the reliability coefficient Cronbach's, interrater analysis, exploratory, and confirmatory factor analysis. The second sample was recruited to investigate the factor structure by combining it with the Safe Sex Behavior Questionnaire (SSBQ). The sociodemographic data, such as hours of use and number of dates, were also investigated.
The Polish participants' responses to the PTUS (sample 1: N = 271, sample 2: N = 162) revealed the one-factor structure of the tool. The reliability of the measurement was α = 0.80. The construct validity was confirmed. The results showed a significant, negative, and weak correlation between the PTUS and SSBQ scores and their subscales: risky sexual behaviors (r = -0.18), condom use (r = -0.22), and avoidance of body fluids (r = -0.17). Moreover, the number of partners met in the real world had a statistically significant, moderate relationship with the PTUS scores.
The PTUS measurement is valid and reliable for the Polish population. The findings highlight the need for harm prevention strategies related to potentially addictive Tinder use, as well as the possible risky sexual behaviors associated with dating app use
The Effect of Repetitive Transcranial Magnetic Stimulation on Motor Symptoms in Hereditary Spastic Paraplegia
Background. Hereditary spastic paraplegia (HSP) is a heterogeneous group of inherited disorders affecting predominantly the motor cortex and pyramidal tract, which results in slowly progressing gait disorders, as well as spasticity and weakness of lower extremities. Repetitive transcranial magnetic stimulation (rTMS) has been previously investigated as a therapeutic tool for similar motor deficits in a number of neurologic conditions. The aim of this randomized, controlled trial was to investigate the therapeutic potential of rTMS in various forms of HSP, including pure and complicated forms, as well as adrenomyeloneuropathy. Methods. We recruited 15 patients (five women and 10 men; mean age 43.7±10.6 years) with the mentioned forms of HSP. The intervention included five sessions of bilateral 10 Hz rTMS over primary motor areas of the muscles of lower extremities and five sessions of similar sham stimulation. Results. One patient dropped out due to seizure, and 14 patients completed the study protocol. After real stimulation, the strength of the proximal and distal muscles of lower extremities increased, and the spasticity of the proximal muscles decreased. Change in spasticity was still present during follow-up assessment. No effect was observed regarding gait velocity. No changes were seen after sham stimulation. A post hoc analysis revealed an inverse relation between motor threshold and the change of the strength after active rTMS. Conclusions. rTMS may have potential in improving weakness and spasticity of lower extremities in HSP, especially of proximal muscles whose motor areas are located more superficially. This trial is registered with Clinicaltrials.gov NCT03627416
Selective inhibition of HDAC6 sensitizes cutaneous T-cell lymphoma to PI3K inhibitors.
Histone deacetylase (HDAC) inhibitors, approved for the treatment of cutaneous T-cell lymphoma (CTCL), are non-selective agents associated with an unsatisfactory response and considerable side-effects. Targeting single HDAC isoforms is considered to provide novel therapeutic options. HDAC6 is overexpressed in primary samples from patients with CTCL and preclinical studies using transgenic mice that spontaneously develop a CTCL-like disease, have suggested that combinations including HDAC6 inhibitors may be successful in the treatment of CTCL. PI3K inhibition is currently being tested in clinical trials for CTCL with promising results. Since HDAC6 is known to diminish the activity of Akt via its deacetylation, the aim of the present study was to evaluate the therapeutic potential of selective HDAC6 inhibitors in combination with PI3K inhibitors in CTCL. Through the genetic and pharmacological inhibition of HDAC6, it was demonstrated that combining HDAC6 with PI3K inhibition may be an attractive therapeutic option for patients with CTCL
White matter structure in youth with behavioral and emotional dysregulation disorders a probabilistic tractographic study
Importance: Psychiatric disorders in youth characterized by behavioral and emotional dysregulation are often comorbid and difficult to distinguish. An alternative approach to conceptualizing these disorders is to move toward a diagnostic system based on underlying pathophysiologic processes that may cut across conventionally defined diagnoses. Neuroimaging techniques have potentials for the identification of these processes.Objective: To determine whether diffusion imaging, a neuroimaging technique examining white matter (WM) structure, can identify neural correlates of emotional dysregulation in a sample of youth with different psychiatric disorders characterized by behavioral and emotional dysregulation.Design, Setting, And Participants: Using global probabilistic tractography,we examined relationships betweenWMstructure in key tracts in emotional regulation circuitry (ie, cingulum, uncinate fasciculus, and forceps minor) and (1) broader diagnostic categories of behavioral and emotional dysregulation disorders (DDs) and (2) symptom dimensions cutting across conventional diagnoses in 120 youth with behavioral and/or emotional DDs, a referred sample of the Longitudinal Assessment of Manic Symptoms (LAM) study. Thirty age- and sex-matched typically developing youth (control participants) were included. Multivariate multiple regression models were used. The study was conducted from July 1, 2010, to February 28, 2014.Main Outcomes And Measures: Fractional anisotropy aswell as axial and radial diffusivity were estimated and imported into a well-established statistical package.We hypothesized that (1) youth with emotional DDs and those with both behavioral and emotional DDs would show significantly lower fractional anisotropy compared with youth with behavioral DDs in these WM tracts and (2) that there would be significant inverse relationships between dimensional measures of affective symptom severity and fractional anisotropy in these tracts across all participants.Results: Multivariate multiple regression analyses revealed decreased fractional anisotropy and decreased axial diffusivity within the uncinate fasciculus in youth with emotional DDs vs those with behavioral DDs, those with both DDs, and the controls (F6,160 = 2.4; P = .032; all pairwise comparisons, P 3,85 = 2.8; P = .044).Conclusions And Relevance: These findings suggest that abnormal uncinate fasciculus and cingulumWMstructure may underlie emotional, but not behavioral, dysregulation in pediatric psychiatric disorders and that a different neural mechanism may exist for comorbid emotional and behavioral DDs