239 research outputs found
Multi-temporal GNSS, RTS, and InSAR for very slow-moving landslide displacement analysis
Very slow-moving landslides threaten infrastructures and safety, yet detecting their subtle, long-term displacements remains challenging. The eastern slope of Mount Amiata, Tuscany, Italy, where high-precision geodetic monitoring is required to control the very slow-moving landslides affecting the area, represents an example of this issue. Namely, in this study we assess whether the joint exploitation of multi-temporal GNSS (continuous and periodic), Robotic Total Stations (RTS), and Persistent Scatterer InSAR techniques allows us to provide a coherent picture of very slow-moving landslide areas. While GNSS provides useful long-term displacement data, it may be affected by low signal-to-noise ratio, limiting precision to cm-mm level. Hence, to refine the outputs, we implement statistical time-series analysis, including weighted linear regression and 95 % confidence intervals. RTS delivered high-precision 3D data associated to local-scale measurements, while InSAR extended coverage to wider areas, resolving East-West and Vertical components from Sentinel-1 data. We highlight that, since 2019, the monitoring network has recorded horizontal displacements of ca. 10–15 mm/year, while vertical movements reached −7 mm/year, well correlating with local morphology and bedrock geology characteristics. We also perform a comparison of GNSS and RTS measurements with InSAR datasets, highlighting the limitations of InSAR in vegetated and geometrically complex terrains, while also confirming its value in capturing large scale displacement trends. The findings demonstrate that, despite their individual limitations, the joint exploitation of GNSS, RTS, and InSAR allow to provide a comprehensive framework for very slow-moving landslide areas. The scalable, cost-effective multi-source system here developed represents a robust approach for monitoring very slow-moving landslides, supporting risk mitigation strategies in landslide-prone regions
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
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
An Overview of the 2014 ALMA Long Baseline Campaign
A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to
make accurate images with resolutions of tens of milliarcseconds, which at
submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop
and test this capability, a Long Baseline Campaign (LBC) was carried out from
September to late November 2014, culminating in end-to-end observations,
calibrations, and imaging of selected Science Verification (SV) targets. This
paper presents an overview of the campaign and its main results, including an
investigation of the short-term coherence properties and systematic phase
errors over the long baselines at the ALMA site, a summary of the SV targets
and observations, and recommendations for science observing strategies at long
baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also
compared to VLA 43 GHz results, demonstrating an agreement at a level of a few
percent. As a result of the extensive program of LBC testing, the highly
successful SV imaging at long baselines achieved angular resolutions as fine as
19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now
possible, and opens up new parameter space for submm astronomy.Comment: 11 pages, 7 figures, 2 tables; accepted for publication in the
Astrophysical Journal Letters; this version with small changes to
affiliation
Comparison between direct measurements and indirect estimations of hydraulic conductivity for slope deposits of the North-Western Tuscany, Italy
Hydraulic conductivity (K) is a relevant engineering geology property of deposits that cover the geological bedrock (Slope Deposits – SD). This parameter is useful for many applications fields such as: simulations of both infiltration and runoff processes, hillslope stability numerical analysis, hydrological studies, soil science and environmental problems. A wide range of methods are available in the literature in order to estimate K. Anyhow, they can be divided into direct measurement (field and laboratory test) and indirect estimations (eg. correlation from grain size, pedotransfer functions). However, many factors (eg. SD grain size, bulk density, organic matter, etc.) can affect the K value hence the determination of K within SD is often a challenge. Moreover, the value of K generally shows an high spatial variability requiring a large number of direct measurements to obtain robust spatial estimations. Indirect methods may be used alternatively or in pair with direct methods. However, relations between K and other soil physical properties are generally suitable only for specific type of soils, therefore, the application of those relations are constrained. In this work a wide (about 200) set of field measurements were performed in North-Western Tuscany in order to assess the variability of K in the vadose zone for SD characterized by different grain size composition. Measurements were carried out by means of both constant and falling head permeameters, as well as double ring infiltrometer. In the test sites engineering geology properties of SD such as bulk density and depth have been collected, moreover, samples have been collected for laboratory analysis. A statistical analysis of the K value has been performed for SD characterized by different grain size distribution and geological bedrock. Moreover, a comparison between the field methods have been also performed. Finally, a comparison between measured and estimated values of K has been done in order to assess the reliability of different equations to predict K. The results show that the K value varies across: different geological settings, the SD profile and the geographic neighborhood of the test site. Moreover, the results highlight that the indirect methods used in this work have to be used carefully in our study area
DSA-10: A prototype array for localizing fast radio bursts
The Deep Synoptic Array 10 dish prototype is an instrument designed to detect
and localise fast radio bursts with arcsecond accuracy in real time. Deployed
at Owens Valley Radio Observatory, it consists of ten 4.5m diameter dishes,
equipped with a 250MHz bandwidth dual polarisation receiver, centered at
1.4GHz. The 20 input signals are digitised and field programmable gate arrays
are used to transform the data to the frequency domain and transmit it over
ethernet. A series of computer servers buffer both raw data samples and perform
a real time search for fast radio bursts on the incoherent sum of all inputs.
If a pulse is detected, the raw data surrounding the pulse is written to disk
for coherent processing and imaging. The prototype system was operational from
June 2017 - February 2018 conducting a drift scan search. Giant pulses from the
Crab pulsar were used to test the detection and imaging pipelines. The 10-dish
prototype system was brought online again in March 2019, and will gradually be
replaced with the new DSA-110, a 110-dish system, over the next two years to
improve sensitivity and localisation accuracy.Comment: 10 pages, 13 figures, accepted by MNRA
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