242 research outputs found
Weathering Effects on Engineering Geological Properties of Trachydacitic Volcanic Rocks from the Monte Amiata (Southern Tuscany, Italy)
Variability in lithology and weathering degree affects physical and mechanical properties
of rocks. In this study, we investigated the relationships between weathering degree and engineering
geological properties of trachydacitic volcanic rocks from Monte Amiata (central Italy) by coupling
field and laboratory analyses. We collected in situ Schmidt hammer tests in the field. We evaluated
weathering quantifying the percentage of secondary minerals through thermal analysis in the
laboratory. We also determined dry density (rd), specific gravity of solids (Gs), porosity (n) and
two-dimensional (2D) porosity as resulted from scanning electron microscopy investigations. The
results of our study indicate a negative linear correlation between Schmidt hammer rebound values
and secondary mineral percentage. This correlation provides a tool to quantitatively estimate the
deterioration of rock uniaxial compressive strength (UCS) as weathering increases. Moreover, thermal
analysis turned out to be a quantitative and reproducible method to evaluate weathering degree of
magmatic rocks
Solving the Corner-Turning Problem for Large Interferometers
The so-called corner turning problem is a major bottleneck for radio
telescopes with large numbers of antennas. The problem is essentially that of
rapidly transposing a matrix that is too large to store on one single device;
in radio interferometry, it occurs because data from each antenna needs to be
routed to an array of processors that will each handle a limited portion of the
data (a frequency range, say) but requires input from each antenna. We present
a low-cost solution allowing the correlator to transpose its data in real time,
without contending for bandwidth, via a butterfly network requiring neither
additional RAM memory nor expensive general-purpose switching hardware. We
discuss possible implementations of this using FPGA, CMOS, analog logic and
optical technology, and conclude that the corner turner cost can be small even
for upcoming massive radio arrays.Comment: Revised to match accepted MNRAS version. 7 pages, 4 fig
Ethanol/Naltrexone Interactions at the mu-Opioid Receptor. CLSM/FCS Study in Live Cells
BACKGROUND:
Alcoholism is a widespread chronic disorder of complex aetiology with a significant negative impact on the individual and the society. Mechanisms of ethanol action are not sufficiently well understood at the molecular level and the pharmacotherapy of alcoholism is still in its infancy. Our study focuses at the cellular and molecular level on ethanol-induced effects that are mediated through the micro-opioid receptor (MOP) and on the effects of naltrexone, a well-known antagonist at MOP that is used clinically to prevent relapse in alcoholism.
METHODOLOGY/PRINCIPAL FINDINGS:
Advanced fluorescence imaging by Confocal Laser Scanning Microscopy (CLSM) and Fluorescence Correlation Spectroscopy (FCS) are used to study ethanol effects on MOP and plasma membrane lipid dynamics in live PC12 cells. We observed that relevant concentrations of ethanol (10-40 mM) alter MOP mobility and surface density, and affect the dynamics of plasma membrane lipids. Compared to the action of specific ligands at MOP, ethanol-induced effects show complex kinetics and point to a biphasic underlying mechanism. Pretreatment with naloxone or naltrexone considerably mitigates the effects of ethanol.
CONCLUSIONS/SIGNIFICANCE:
We suggest that ethanol acts by affecting the sorting of MOP at the plasma membrane of PC12 cells. Naltrexone exerts opposite effects on MOP sorting at the plasma membrane, thereby countering the effects of ethanol. Our experimental findings give new insight on MOP-mediated ethanol action at the cellular and molecular level. We suggest a new hypothesis to explain the well established ethanol-induced increase in the activity of the endogenous opioid system
CDC in brief 2013
With the start of the 113th Congress, we\u2019d like to take an opportunity to (re)introduce the Centers for Disease Control and Prevention (CDC), and provide some helpful information about our agency and its work. This E-Brief contains links to useful information about CDC\u2019s science, budget, and presence on the ground. For quick access to additional information about CDC\u2019s work, please contact the CDC Washington Office at (202) 245-0600, and see below for information about how CDC Washington can help you.CS238048-6What CDC does -- Fast facts -- CDC on the ground -- How can CDC Washington help you?201
OXTR Gene DNA Methylation Levels Are Associated with Discounting Behavior with Untrustworthy Proposers
Individual differences in temporal and probabilistic discounting are associated with a wide range of life outcomes in literature. Traditional approaches have focused on impulsiveness and cognitive control skills, on goal-oriented personality traits as well as on the psychological perception of time. More recently, literature started to consider the role of social and contextual factors in discounting behavior. Between others, higher generalized trust in human beings and specific trust in people who will deliver the future/probabilistic rewards have been related to a stronger willingness to wait and to assume risk. Moreover, the tendency to trust others has been associated with the oxytocin receptor gene regulation that can be modified by life experiences. In this perspective, we hypothesized that differences in the tendency to wait and to take risks for a more desirable reward according to the proposer’s trustworthiness could be related to a different level of DNA methylation at the oxytocin receptor gene. Findings confirmed that participants are less willing to wait and to risk when the proposer is considered highly untrustworthy and revealed how higher oxytocin receptor gene DNA methylation is associated with a stronger effect due to the presence of an untrustworthy proposer. Limits and future directions are outlined
Olfactory receptor 984: a new target for obesity in rats and humans?
Aims: Obesity is a complex multifactorial and heterogeneous condition with an important genetic component matched with behavioral and environmental factors. Feeding behavior and body weight are controlled through complex interactions between the central nervous system (CNS) and peripheral organs. The aim of the present study was to identify and functionally characterize candidate gene/s involved in the development of resistance to diet-induced obesity (DIO) in rats.
Methods: RNA Chip-Technology and genotype analysis was done in 10 visceral adipose tissue samples of DR (n=5) and DIO (n=5) rats. The most promising candidate gene, OR6C3 (orthologous with the rat Olr984 and mouse Olfr788) was measured by quantitative real-time PCR in adipocytes and stromal vascular fraction (SVF) from paired samples of human visceral and subcutaneous adipose tissue (AT) (n=225). Moreover, Olfr788 expression in 3T3-L1 adipocytes was measured after treatment with various hormones and cytokines.
Results: Gene expression analyses showed Olr984 differently regulated in DIO-resistant rats. In the subcutaneous AT of human samples we found a down-regulation of OR6C3 compared to the visceral AT of the same population, independent of gender, glucose tolerance or type 2 diabetes. OR6C3 is more expressed in SVF than in adipocytes. Interestingly, treatment of 3T3-L1 cells with insulin decreased Olfr788 expression mRNA compared to untreated controls.
Conclusions: Olr984 is a novel candidate gene related to diet-induced obesity in rats. Moreover, variation in human mRNA expression in AT is related to obesity parameters and glucose homeostasis, which might be attributed to the regulatory role of insulin on the Olr984
Involvement of DAT1 gene on internet addiction. Cross-correlations of methylation levels in 5'-utr and 3’-UTR genotypes, interact with impulsivity and attachment-driven quality of relationships
Internet influences our communication, social and work interactions, entertainment, and many other aspects of life. Even if the original purpose was to simplify our lives, an excessive and/or maladaptive use of it may have negative consequences. The dopamine transporter (DAT1) gene was studied in relation to addictions, including excessive use of the Internet. The crucial role of DAT1 was previously underlined in modulating emotional aspects, such as affiliative behaviors. The present research follows a new approach based on cross-correlation between (de)methylation levels in couples of CpG loci, as previously shown. We investigated the possible relationships between Internet addiction, impulsivity, quality of attachment, DAT1 genotypes (from the 3′-untranslated region (UTR) variable number of tandem repeats (VNTR) poly-morphism), and the dynamics of methylation within the 5’-UTR of the DAT1 gene. From a normative sample of 79 youths, we extrapolated three subgroups a posteriori, i.e., one “vulnerable” with high Internet Addiction Test (IAT) scores (and high Barrat Impulsivity Scale (BIS) scores; n = 9) and two “controls” with low BIS scores and 10/10 vs. 9/x genotype (n = 12 each). Controls also had a “secure” attachment pattern, while genotypes and attachment styles were undistinguished in the vulnerable subgroup (none showed overt Internet addiction). We found a strongly positive correlation in all groups between CpG2 and CpG3. An unsuspected relationship between the 3’-UTR genotype and a 5’-UTR intra-motif link was revealed by CpG5–CpG6 comparison. The negative correlation between the CpG3–CpG5 positions was quite significant in the control groups (both with genotype 10/10 and with genotype 9/x), whereas a tendency toward positive correlation emerged within the high IAT group. In conclusion, future attention shall be focused on the intra-and inter-motif interactions of methylation on the CpG island at the 5′-UTR of DAT1
Maintenance and Consolidation Therapy in Patients with Unresectable Stage III/IV Non-Small Cell Lung Cancer
Lung cancer remains the most common cancer and the leading cause of cancer-related mortality. Despite continuing improvements in chemoradiotherapy regimens and the recent clinical validation of particular agents as maintenance treatments in advanced disease, there remains an unmet need for new therapies with clinically proven value in the treatment of unresectable stage III NSCLC. Studies are under way to determine whether the use of anticancer vaccines may be an effective strategy in the treatment of NSCLC
Socio-demographic and clinical characterization of patients with obsessive-compulsive tic-related disorder (OCTD) : An Italian multicenter study
© Copyright by Pacini Editore SrlIn the DSM-5 a new "tic-related" specifier for obsessive compulsive disorder (OCD) has been introduced, highlighting the importance of an accurate characterization of patients suffering from obsessive-compulsive tic-related disorder ("OCTD"). In order to characterize OCTD from a socio-demographic and clinical perspective, the present multicenter study was carried out. The sample consists of 266 patients, divided in two groups with lifetime diagnoses of OCD and OCTD, respectively. OCTD vs OCD patients showed a significant male prevalence (68.5% vs 48.5%; p < .001), a higher rate of psychiatric comorbidities (69.4 vs 50%; p < .001) - mainly with neurodevelopmental disorders (24 vs 0%; p < .001), a lower education level and professional status (middle school diploma: 25 vs 7.6%; full-Time job 44.4 vs 58%; p < .001). Moreover, OCTD vs OCD patients showed significantly earlier age of OCD and psychiatric comorbidity onsets (16.1 ± 10.8 vs 22.1 ± 9.5 years; p < .001, and 18.3 ± 12.8 vs 25.6 ± 9.4: p < .001, respectively). Patients with OCTD patients were treated mainly with antipsychotic and with a low rate of benzodiazepine (74.2 vs 38.2% and 20.2 vs 31.3%, respectively; p < .001). Finally, OCTD vs OCD patients showed higher rates of partial treatment response (58.1 vs 38%; p < .001), lower rates of current remission (35.5 vs 54.8%; p < .001) and higher rates of suicidal ideation (63.2 vs 41.7%; p < .001) and attempts (28.9 vs 8.3%; p < .001). Patients with OCTD report several unfavorable socio-demographic and clinical characteristics compared to OCD patients without a history of tic. Additional studies on larger sample are needed to further characterize OCTD patients from clinical and therapeutic perspectives.Peer reviewedFinal Published versio
Iron-dependent trafficking of 5-lipoxygenase and impact on human macrophage activation
5-lipoxygenase (5-LOX) is a non-heme iron-containing dioxygenase expressed in immune cells that catalyzes the two initial steps in the biosynthesis of leukotrienes. It is well known that 5-LOX activation in innate immunity cells is related to different iron-associated proinflammatory disorders, including cancer, neurodegenerative diseases, and atherosclerosis. However, the molecular and cellular mechanism(s) underlying the interplay between iron and 5-LOX activation are largely unexplored. In this study, we investigated whether iron (in the form of Fe3+ and hemin) might modulate 5-LOX influencing its membrane binding, subcellular distribution, and functional activity. We proved by fluorescence resonance energy transfer approach that metal removal from the recombinant human 5-LOX, not only altered the catalytic activity of the enzyme, but also impaired its membrane-binding. To ascertain whether iron can modulate the subcellular distribution of 5-LOX in immune cells, we exposed THP-1 macrophages and human primary macrophages to exogenous iron. Cells exposed to increasing amounts of Fe3+ showed a redistribution (ranging from ~45 to 75%) of the cytosolic 5-LOX to the nuclear fraction. Accordingly, confocal microscopy revealed that acute exposure to extracellular Fe3+, as well as hemin, caused an overt increase in the nuclear fluorescence of 5-LOX, accompanied by a co-localization with the 5-LOX activating protein (FLAP) both in THP-1 macrophages and human macrophages. The functional relevance of iron overloading was demonstrated by a marked induction of the expression of interleukin-6 in iron-treated macrophages. Importantly, pre-treatment of cells with the iron-chelating agent deferoxamine completely abolished the hemin-dependent translocation of 5-LOX to the nuclear fraction, and significantly reverted its effect on interleukin-6 overexpression. These results suggest that exogenous iron modulates the biological activity of 5-LOX in macrophages by increasing its ability to bind to nuclear membranes, further supporting a role for iron in inflammation-based diseases where its homeostasis is altered and suggesting further evidence of risks related to iron overload
- …