25 research outputs found

    Radio emission and particle acceleration in plerionic supernova remnants

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    Plerionic supernova remnants exhibit radio emission with remarkably flat spectral indices ranging from α=0.0\alpha=0.0 to α=−0.3\alpha=-0.3. The origin of very hard particle energy distributions still awaits an explanation, since shock waves generate particle distributions with synchrotron spectra characterized by α≀−0.5\alpha\le-0.5. Acceleration of high energy leptons in magnetohydrodynamic turbulence instead may be responsible for the observed hard spectra. This process is studied by means of relativistic test particle calculations using electromagnetic fields produced by three-dimensional simulations of resistive magnetohydrodynamical turbulence. The particles receive power-law energy spectra N(Îł)∝γ−sN(\gamma)\propto \gamma^{-s} with ss ranging from 1.2 to 1.6, i.e. particle spectra that are required to explain the radio emission of plerions.Comment: 8 pages, 7 Figures, to be published in A&

    Chromosomal aberrations and aneuploidy in oral potentially malignant lesions: distinctive features for tongue

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    <p>Abstract</p> <p>Background</p> <p>The mucosae of the oral cavity are different at the histological level but appear all equally exposed to common genotoxic agents. As a result of this exposure, changes in the mucosal epithelia may develop giving rise to Oral Potentially Malignant Lesions (OPMLs), which with time may in turn progress to Oral Squamous Cell Carcinomas (OSCCs). Therefore, much effort should be devoted to identify features able to predict the likeliness of progression associated with an OPML. Such features may be helpful in assisting the clinician to establish both appropriate therapies and follow-up schedules. Here, we report a pilot study that compared the occurrence of DNA aneuploidy and chromosomal copy number aberrations (CNAs) in the OPMLs from different oral anatomical subsites.</p> <p>Methods</p> <p>Samples from histologically diagnosed OPMLs were processed for high resolution DNA flow cytometry (hr DNA-FCM) in order to determine the relative DNA content expressed by the DNA index (DI). Additionally, array-Comparative Genomic Hybridization (a-CGH) analysis was performed on DNA obtained from diploid nuclei suspensions directly. When aneuploid nuclei were detected, these were physically separated from diploid nuclei on the base of their DI values by means of a DNA-FCM-Sorter in order to improve the a-CGH analysis.</p> <p>Results</p> <p>Tongue OPMLs were more frequently associated with DNA aneuploidy and CNAs than OPMLs arising from all the other mucosal subsites.</p> <p>Conclusions</p> <p>We suggest that the follow-up and the management of the patients with tongue OPMLs should receive a distinctive special attention. Clearly, this hypothesis should be validated in a prospective clinical study.</p

    A review on experimental and clinical genetic associations studies on fear conditioning, extinction and cognitive-behavioral treatment

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    Fear conditioning and extinction represent basic forms of associative learning with considerable clinical relevance and have been implicated in the pathogenesis of anxiety disorders. There is considerable inter-individual variation in the ability to acquire and extinguish conditioned fear reactions and the study of genetic variants has recently become a focus of research. In this review, we give an overview of the existing genetic association studies on human fear conditioning and extinction in healthy individuals and of related studies on cognitive-behavioral treatment (CBT) and exposure, as well as pathology development after trauma. Variation in the serotonin transporter (5HTT) and the catechol-o-methyltransferase (COMT) genes has consistently been associated with effects in pre-clinical and clinical studies. Interesting new findings, which however require further replication, have been reported for genetic variation in the dopamine transporter (DAT1) and the pituitary adenylate cyclase 1 receptor (ADCYAP1R1) genes, whereas the current picture is inconsistent for variation in the brain-derived neurotrophic factor (BDNF) gene. We end with a discussion of the findings and their limitations, as well as future directions that we hope will aid the field to develop further

    Exploring Spatial Associations between On-Sale Alcohol Availability, Neighborhood Population Characteristics, and Violent Crime in a Geographically Isolated City

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    Objectives. Despite the increasing evidence of the associations between alcohol availability and violence, there are still inconsistent findings on the effects of on-and off-sale alcohol outlets on violent crime. The aim of this study was to examine spatial associations between on-sale alcohol availability, neighborhood characteristics, and violent crime in a geographically isolated city in Texas. Methods. Geographically weighted regression (GWR) and global regression models were employed to analyze the nature of the spatial relationship between violent crime, neighborhood sociocultural characteristics, and on-sale alcohol environment. Results. We found strong effects of neighborhood characteristics combined with on-sale alcohol availability on violence outcomes. Several neighborhood variables combined with alcohol availability explained about 63% of the variability in violence. An additional 7% was explained by the GWR model, while spatially nonstationary associations between violence and some predictor variables were observed. Conclusions. This study provided more credible evidence of the influence of on-sale alcohol outlets on violence in a unique setting. These findings have important policy implications in addressing the question of public health consequences of alcohol-related violence in local contexts

    The influence of reported ADHD and substance abuse on suicidal ideation in a non-clinical sample of young men

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    This study intended to determine whether former and current ADHD symptomatology is associated with suicidal ideation in a non-clinical sample of 18 year old males. We performed a cross sectional descriptive study of 3280 men during the examination for military service. The investigation included a screening for substance abuse, past (WURS) and current (ADHD symptom checklist) ADHD symptomatology and an interview about suicidal ideations. We found a correlation of suicidal ideations with a history of ADHD symptomatology. ADHD symptoms were strongly consistent over time. These results indicate that a history of (diagnosed or undiagnosed) ADHD could be a predictor for suicidal ideations. Surveying a history of ADHD in primary care might help identify subjects at risk for suicidal tendencies.(VLID)348261

    Factor Structure of CIWA-Ar in Alcohol Withdrawal

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    Objective. To identify the underlying factor structure of alcohol withdrawal syndrome, as measured with CIWA-Ar. Methods. Exploratory factor analysis was conducted on the items of CIWA-Ar. On 201 alcohol-dependent male patients seeking treatment for alcohol withdrawal at 36 hours of abstinence. Results. A three-factor solution was obtained that accounted for 68.74% of total variance. First factor had loading from four items (34.34% variance), second factor also had four items (24.25% variance), and the third had two items (10.04% variance). Conclusions. Factor analysis reveals the existence of multidimensionality of alcohol withdrawal as measured with CIWA-Ar and we found three factors that can be named as delirious, autonomic and nonspecific factors

    Genetic Markers of Comorbid Depression and Alcoholism in Women

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    Background: Alcohol dependence (AD) is often accompanied by comorbid depression. Recent clinical evidence supports the benefit of subtype-specific pharmacotherapy in treating the population of alcohol-dependent subjects with comorbid major depressive disorder (MDD). However, in many alcohol-dependent subjects, depression is a reactive response to chronic alcohol use and withdrawal and abates with a period of abstinence. Genetic markers may distinguish alcohol-dependent subjects with MDD not tied chronologically and etiologically to their alcohol consumption. In this work, we investigated the association of adenylyl cyclase genes (ADCY1-9), which are implicated in both AD and mood disorders, with alcoholism and comorbid depression. Methods: Subjects from Vienna, Austria (n = 323) were genotyped, and single nucleotide polymorphisms (1,152) encompassing the genetic locations of the 9 ADCY genes were examined. The Vienna cohort contained alcohol-dependent subjects differentiated using the Lesch Alcoholism Typology. In this typology, subjects are segregated into 4 types. Type III alcoholism is distinguished by co-occurrence of symptoms of depression and by affecting predominantly females. Results: We identified 4 haplotypes associated with the phenotype of Type III alcoholism in females. One haplotype was in a genomic area in proximity to ADCY2, but actually within a lincRNA gene, 2 haplotypes were within ADCY5, and 1 haplotype was within the coding region of ADCY8. Three of the 4 haplotypes contributed independently to Type III alcoholism and together generated a positive predictive value of 72% and a negative predictive value of 78% for distinguishing women with a Lesch Type III diagnosis versus women designated as Type I or II alcoholics. Conclusions: Polymorphisms in ADCY8 and ADCY5 and within a lincRNA are associated with an alcohol-dependent phenotype in females, which is distinguished by comorbid signs of depression. Each of these genetic locations can rationally contribute to the polygenic etiology of the alcoholism/depression phenotype, and the use of these genetic markers may aid in choosing appropriate and beneficial treatment strategies. © 2012 by the Research Society on Alcoholism
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