709 research outputs found
Re-calibration of the magnitude scales at Campi Flegrei, Italy, on the basis of measured path and site and transfer functions
The quantification of the seismic energy of earthquakes occurring in volcanic regions is of great importance in order to better understand the dynamics of the volcano. The amount of the released energy and its variation during seismic crises can be considered as an indicator of the source processes acting inside the volcano. In this context, the effect of the propagation in attenuative media should be considered to correct for path effects and to properly estimate the seismic energy released at the source. Moreover, in order to allow a comparison with the dynamic processes occurring in different volcanic areas, the use of magnitude scales as homogeneous as possible is strongly recommended,
In this framework, new duration-based Local (Ml) and Moment (Mw) magnitude scales are obtained for the Campi Flegrei area (southern Italy), by analysing a data-set of local volcano-tectonic earthquakes. First the S-wave quality factor for the investigated area was experimentally calculated and then the distance-correction curve, logA0(r), to be used in the Richter formula Ml = logAmax â logA0(r), was numerically estimated by measuring the attenuation properties and hence propagating a synthetic S-wave-packet in the earth medium. The Local magnitude scale was normalized in order to fit the Richter formula valid for Southern California at a distance of 10 km. Ml magnitude was estimated by synthesizing Wood-Anderson seismograms and measuring the maximum amplitude. For the same data-set, Moment magnitude from S-wave distance and site corrected displacement spectra was obtained. Comparisons between Local and Moment magnitudes determined in the present paper, and the old Duration magnitude (Md) routinely used at the Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Vesuviano are presented. Moreover, relationships between Ml and Mw calculated for two reference sites are also derived
Conservation Genetics of Mediterranean Brown Trout in Central Italy (Latium): A Multi-Marker Approach
Brown trout is considered a complex of incipient species, including several phylogenetic
lineages, whose natural distribution in the Mediterranean area has been altered, since the beginning
of the 1900s, by massive introductions of domestic strains of Atlantic origin to support fisheries.
Introduced trout naturalize in new suitable environments and extensively hybridize with native
populations. Here, we characterized putatively neutral and adaptive genetic variability and popu lation structure of Mediterranean brown trout from six river catchments in central peninsular Italy,
as revealed by both mitochondrial (Control Region) and nuclear (microsatellites, LDH-C1, major
histocompatibility complex) markers. We quantified the admixture of wild populations with hatchery
strains and evaluated the effects of domestic trout introductions on shaping population genetics. Our
analyses indicated: (1) a composite picture of genetic variability in the area, with the presence of all
native Mediterranean trout mitochondrial lineages (âAdriaticâ, âMediterraneanâ, âmarmoratusâ), vari ous frequencies of allochthonous genotypes and different rates of introgression among sampling sites;
(2) asymmetric mito-nuclear introgression; (3) increasing nuclear marker diversity with increasing
levels of admixture across populations; (4) strong population structure coupled with relatively low
effective population size. Data allowed the identification of five management units and we propose
specific actions to support ongoing and future conservation strategies within the examined are
Recalibration of the Magnitude Scales at Campi Flegrei, Italy, on the Basis of Measured Path and Site and Transfer Functions
New duration-based local (ML) and moment (Mw) magnitude scales are
obtained for the Campi Flegrei area through analysis of a dataset of local volcanotectonic
earthquakes. First, the S-wave quality factor for the investigated area was
experimentally calculated, and then the distance-correction curve, log A0(r), to be
used in the Richter formula ML = log Amax â log A0(r), was numerically estimated
by measuring the attenuation properties and, hence, propagating a synthetic S-wave
packet in the earth medium. The local magnitude scale was normalized to fit the
Richter formula that was valid for Southern California at a distance of 10 km. ML
was estimated by synthesizing WoodâAnderson seismograms and measuring the
maximum amplitude. For the same dataset, the moment magnitude was obtained from
S-wave distance-corrected and site-corrected displacement spectra. Comparisons
between local and moment magnitudes determined, along with the old duration
magnitude (MD) routinely used at the Istituto Nazionale di Geofisica e Vulcanologiaâ
Osservatorio Vesuviano, are presented and discussed. Moreover, the relationships
between ML and Mw calculated for two reference sites are also derived
Balancing selection, genetic drift, and human-mediated introgression interplay to shape MHC (functional) diversity in Mediterranean brown trout
The extraordinary polymorphism of major histocompatibility complex (MHC) genes is
considered a paradigm of pathogen-mediated balancing selection, although empirical
evidence is still scarce. Furthermore, the relative contribution of balancing selection
to shape MHC population structure and diversity, compared to that of neutral forces,
as well as its interaction with other evolutionary processes such as hybridization, re mains largely unclear. To investigate these issues, we analyzed adaptive (MHC-DAB
gene) and neutral (11 microsatellite loci) variation in 156 brown trout (Salmo trutta
complex) from six wild populations in central Italy exposed to introgression from do mestic hatchery lineages (assessed with the LDH gene). MHC diversity and structur ing correlated with those at microsatellites, indicating the substantial role of neutral
forces. However, individuals carrying locally rare MHC alleles/supertypes were in bet ter body condition (a proxy of individual fitness/parasite load) regardless of the zygo sity status and degree of sequence dissimilarity of MHC, hence supporting balancing
selection under rare allele advantage, but not heterozygote advantage or divergent
allele advantage. The association between specific MHC supertypes and body condi tion confirmed in part this finding. Across populations, MHC allelic richness increased
with increasing admixture between native and domestic lineages, indicating intro gression as a source of MHC variation. Furthermore, introgression across populations
appeared more pronounced for MHC than microsatellites, possibly because initially
rare MHC variants are expected to introgress more readily under rare allele advan tage. Providing evidence for the complex interplay among neutral evolutionary forces,
balancing selection, and human-mediated introgression in shaping the pattern of
MHC (functional) variation, our findings contribute to a deeper understanding of the
evolution of MHC genes in wild populations exposed to anthropogenic disturbance
Shear-wave velocity structure at Mt. Etna from inversion of Rayleigh-wave dispersion patterns (2 s < T < 20 s)
In the present study, we investigated the dispersion characteristics of
medium-to-long period Rayleigh waves (2 s < T < 20 s) using both singlestation
techniques (multiple-filter analysis, and phase-match filter) and
multichannel techniques (horizontal slowness [p] and angular frequency
[~] stack, and cross-correlation) to determine the velocity structure for
the Mt. Etna volcano. We applied these techniques to a dataset of
teleseisms, as regional and local earthquakes recorded by two broad-band
seismic arrays installed at Mt. Etna in 2002 and 2005, during two seismic
surveys organized by the Istituto Nazionale di Geofisica e Vulcanologia
(INGV), sezione di Napoli. The dispersion curves obtained showed phase
velocities ranging from 1.5 km/s to 4.0 km/s in the frequency band 0.05
Hz to 0.45 Hz. We inverted the average phase velocity dispersion curves
using a non-linear approach, to obtain a set of shear-wave velocity models
with maximum resolution depths of 25 km to 30 km. Moreover, the
presence of lateral velocity contrasts was checked by dividing the whole
array into seven triangular sub-arrays and inverting the dispersion curves
relative to each triangle
Analysis and interpretation of the impact of missense variants in cancer
Large scale genome sequencing allowed the identification of a massive number of genetic variations, whose impact on human health is still unknown. In this review we analyze, by an in silico-based strategy, the impact of missense variants on cancer-related genes, whose effect on protein stability and function was experimentally determined. We collected a set of 164 variants from 11 proteins to analyze the impact of missense mutations at structural and functional levels, and to assess the performance of state-of-the-art methods (FoldX and Meta-SNP) for predicting protein stability change and pathogenicity. The result of our analysis shows that a combination of experimental data on protein stability and in silico pathogenicity predictions allowed the identification of a subset of variants with a high probability of having a deleterious phenotypic effect, as confirmed by the significant enrichment of the subset in variants annotated in the COSMIC database as putative cancer-driving variants. Our analysis suggests that the integration of experimental and computational approaches may contribute to evaluate the risk for complex disorders and develop more effective treatment strategie
Acquisizione di rumore sismico nell'Appennino Reggiano Modenese 11-15 aprile 2006
Tra lâ11 e il 15 aprile 2006 Ăš stata condotta una campagna di acquisizione di rumore sismico in
alcuni siti in frana dellâAppennino Settentrionale. Lo scopo dellâesperimento Ăš quello di stimare gli
effetti di sito su corpi franosi tipici dellâAppennino Modenese e Reggiano, nonchĂ© di studiare il
comportamento delle frane quando sono soggette ad eventi sismici.
Le registrazioni di rumore sono state effettuate con stazioni equipaggiate con sensori a corto
periodo a tre componenti. Per la stima dellâamplificazione locale Ăš stata scelta una serie di siti
caratterizzati da litologie diverse. Inoltre, in siti omogenei e ben studiati dal punto di vista
strutturale, sono state effettuate delle misure di rumore in configurazione di array per la stima di un
modello di velocitĂ superficiale, allo scopo di confrontare i risultati sperimentali con le funzioni di
trasferimento teoriche. La durata delle registrazione non Ăš stata inferiore ad unâora per ogni sito.
Le misure sono state effettuate sulle frane di Caâ Lita (MO), Cavola (RE) e La Lezza Nuova (RE).
Tutte e tre sono frane da colata, caratterizzate dalla presenza in superficie di strati di argille, e sono
state studiate dal punto di vista strutturale, tra lâaltro attraverso pozzi di sondaggio ed esperimenti di
sismica attiva
The Impact of the Th17:Treg axis On the Iga-Biome across the Glycemic Spectrum
Secretory IgA (SIgA) is released into mucosal surfaces where its function extends beyond that of host defense to include the shaping of resident microbial communities by mediating exclusion/inclusion of respective microbes and regulating bacterial gene expression. In this capacity, SIgA acts as the fulcrum on which host immunity and the health of the microbiota are balanced. We recently completed an analysis of the gut and salivary IgA-Biomes (16S rDNA sequencing of SIgA-coated/uncoated bacteria) in Mexican-American adults that identified IgA-Biome differences across the glycemic spectrum. As Th17:Treg ratio imbalances are associated with gut microbiome dysbiosis and chronic inflammatory conditions such as type 2 diabetes, the present study extends our prior work by examining the impact of Th17:Treg ratios (pro-inflammatory:anti-inflammatory T-cell ratios) and the SIgA response (Th17:Treg-SIgA axis) in shaping microbial communities. Examining the impact of Th17:Treg ratios (determined by epigenetic qPCR lymphocyte subset quantification) on the IgA-Biome across diabetes phenotypes identified a proportional relationship between Th17:Treg ratios and alpha diversity in the stool IgA-Biome of those with dysglycemia, significant changes in community composition of the stool and salivary microbiomes across glycemic profiles, and genera preferentially abundant by T-cell inflammatory phenotype. This is the first study to associate epigenetically quantified Th17:Treg ratios with both the larger and SIgA-fractionated microbiome, assess these associations in the context of a chronic inflammatory disease, and offers a novel frame through which to evaluate mucosal microbiomes in the context of host responses and inflammation
Integrated stratigraphy for the Late Quaternary in the eastern Tyrrhenian Sea
A high-resolution integrated stratigraphy is presented for the Late Quaternary in the southern-eastern Tyrrhenian Sea. It is based on calcareous plankton taxa (planktonic foraminifera and nannoplankton) distribution, d18OGlobigerinoides ruber record, tephrostratigraphy and radiometric dating methods (210Pb and 137Cs, AMS 14C) for a composite sediment core (from the top to the bottom, C90-1m, C90 and C836) from
the continental shelf of the Salerno Gulf. High sedimentation rates from ca 1 cm/100 y for the early Holocene, to 3.45 cm/100 y for the middle Holocene to 8.78 cm/100 y from late Holocene and to 20 cm/100 y for the last 600 AD, make this area an ideal marine archive of secular paleoclimate changes.
Quantitative distributional trend in planktonic foraminifera identify seven known (1Fe7F) eco-biozones, and several auxiliary bioevents of high potential for Mediterranean biostratigraphic correlation. Recognised
were: the acme distribution of Neogloboquadrina pachyderma r.c. between 10.800 0.400 ka BP and 5.500 0.347 ka BP, a strong increase in abundance of Globorotalia truncatulinoides r.c. and l.c. at 5.500 0.347 ka BP and at 4.571 0.96 ka BP, respectively, an acme interval of Globigerinoides quadrilobatus
(between 3.702 0.048 ka BP and 2.70 0.048 ka BP) and the acme/paracme intervals of
T. quinqueloba (acme between 3.350 0.054 ka BP and 1.492 0.016 ka BP; paracme between
1.492 0.016 ka BP and 0.657 0.025 ka BP; acme beginning 0.657 0.025 ka BP).
These results, integrated with trends of selected calcareous nannofossil species (Florisphaera profunda, Brarudosphaera bigelowii, Gephyrocapsa oceanica and Emiliania huxleyi) and d18OG. ruber signature, are consistent with the most important pre-Holocene and early Holocene paleoclimatic and paleoceanographic phases i.e., the BöllingeAllerod, the Younger Dryas and the time interval of Sapropel S1 deposition in the eastern Mediterranean Sea. These features revealed the high potential of this shallow water environment for high-resolution stratigraphy and correlation for the western Mediterranean.
In addition, the chemical characterization of seven tephra layers supplied further data about the age and the dispersal area of some well-known Campi Flegrei explosive events, inferring the possible occurrence of explosive activity at Vesuvius around the middle of the 6th century, and contributing to refine the tephrostratigraphic framework for the last 15 ka in the south-eastern Tyrrhenian Sea.Published71-852.2. Laboratorio di paleomagnetismoJCR Journalrestricte
Pilot Testing of Peak Alpha Frequency Stability During Repetitive Transcranial Magnetic Stimulation
Over half of those diagnosed with post-traumatic stress disorder (PTSD) have comorbid major depressive disorder (MDD), and rates are even higher among military veterans. Transcranial magnetic stimulation (TMS) may be a safe and efficacious treatment for PTSD, both with and without comorbid MDD. Still, the mechanism of action of TMS is not fully understood, and it remains unclear which stimulation techniques (e.g., target regions, pulse strength/frequency, waveform) optimize treatment for these patients. Recent research indicated that a patient's unique individualized alpha frequency (IAF) may be used to guide brain stimulation treatment, and emerging data suggests that stimulation synchronized to the IAF may be efficacious for MDD. However, to our knowledge there are no studies to date that evaluate the stability of IAF over time in patients with comorbid PTSD and MDD. To this end, we used an eight-lead electroencephalography (EEG) system to record IAF before and after a course of TMS. Stimulation parameters were informed by prior studies of TMS for comorbid PTSD and MDD and included 5 Hz TMS to the left dorsolateral prefrontal cortex, at 120% of motor threshold, 3,000â4,000 pulses per session for up to 40 sessions. We tested whether IAF was changed with a course of TMS therapy and evaluated whether IAF predicted clinical outcomes. We observed no significant changes in IAF from baseline to post-treatment, and there was no relationship between IAF and clinical symptom change. These data demonstrate the stability of IAF with TMS and indicate its utility as a trait marker for future brain stimulation studies. This work does not support the use of IAF as predictor of clinical response to TMS as administered
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