217 research outputs found
Characterization of GPS time series at the Neapolitan volcanic area by statistical analysis
The GPS time series recorded at the Neapolitan volcanic area reveals a very peculiar
behavior. When a clear deformation is observed, the amplitude distribution evolves from a
super‐Gaussian to a broader distribution. This behavior can be characterized by evaluating
the kurtosis. Spurious periodic components were evidenced by independent component
analysis and then removed by filtering the original signal. The time series for all stations was
modeled with a fifth‐order polynomial fit, which represents the deformation history at
that place. Indeed, when this polynomial is subtracted from the time series, the distributions
again become super‐Gaussian. A simulation of the deformation time evolution was
performed by superposing a Laplacian noise and a synthetic deformation history. The
kurtosis of the obtained signals decreases as the superposition increases, enlightening the
insurgence of the deformation. The presented approach represents a contribution aimed
at adding further information to the studies about the deformation at the Neapolitan volcanic
area by revealing geologically relevant data
Spatial and temporal distribution of vertical ground movements at Mt. Vesuvius in the period 1973-2009
Since the early ’70s vertical ground movements at Mount Vesuvius area have been investigated and monitored by the Osservatorio Vesuviano (Istituto Nazionale di Geofisica Vulcanologia - Osservatorio Vesuviano since 2001). This monitoring began with the installation of a high-precision
leveling line in the region at medium-high elevations on the volcano. The deformation pattern and expected strain field assessment methods in the volcanic structure induced by inner sources has demanded in subsequent
years the expansion of the leveling network up to cover the whole volcanic area, enclosing part of leveling lines of other institutions. As a result of this expansion, the Mt. Vesuvius Area Leveling Network (VALN) has today reached a length of about 270 km and consists of 359 benchmarks. It is configured in 21 circuits and is connected, westward, to the Campi Flegrei leveling network and, northward, to the Campania Plain leveling network. The data collected have been carefully re-analyzed for random
and systematic errors and for error propagation along the leveling lines to
identify the areas affected by significant ground movements. For each survey,
the data were rigorously adjusted and vertical ground movements were evaluated by differentiating the heights calculated by the various measurements conducted by the Osservatorio Vesuviano from 1973 to 2009
ANALISI DELLE COMPONENTI INDIPENDETI (ICA) NELLO STUDIO DELLE DEFORMAZIONI DEL SUOLO IN AREE VULCANICHE
Independent component analysis (ICA) is a recent and well-known technique used to separate mixtures of signals. This technique has been applied to the ground deformation time-series recorded at the permanent GPS network of the Osservatorio Vesuviano-INGV in order to characterize the deformation background level in the Neapolitan volcanic area. The analysis revealed the presence of five independent periodic signals common at all the GPS stations; some of them are interpreted as effects of earth tides. The residual signal at each station represent the local ground deformation. Unfortunately the ICA cannot provide the absolute amplitude of the components, indeed we are not able to obtain a residual amplitude at each station. Then we used a stationarity analysis in order to investigate the eventual presence of local transient deformations. The ICA technique combined with the stationarity analysis has shown to be a very interesting tool for individuating ground deformation trends and could be very useful in volcanic areas monitoring
Vitamin D deficiency and tumor aggressiveness in gastroenteropancreatic neuroendocrine tumors
Purpose: Data regarding vitamin D status in patients affected by gastroenteropancreatic (GEP) neuroendocrine tumor (NET) are limited and often showing contrasting results. The aim of the study was to evaluate the incidence of vitamin D deficiency (<20 ng/mL) in GEP-NET patients and compare the 25-hydroxyvitamin D (25(OH)D) levels with clinicopathological parameters and clinical outcome. Methods: A retrospective cross-sectional study including 75 low grade (G1-G2) GEP-NETs and 123 healthy controls matched for age, sex, and body mass index, was performed. Results: GEP-NET patients had significantly lower 25(OH)D levels compared to controls (17.9 ± 7.8 vs 24.2 ± 7.7 ng/mL, p < 0.0001). Ileal NETs were associated to lower 25(OH)D levels compared to other primary tumor sites (p = 0.049) and small bowel resection posed a significant increased risk of severe vitamin D deficiency (OR = 2.81, 95% CI = 1.25–3.37, p = 0.018). No correlation with somatostatin analogs treatment was found. 25(OH)D levels were significantly lower in G2 compared to G1 GEP-NETs (15.6 ± 7.8 vs 19.9 ± 7.4 ng/mL, p = 0.016) and in patients with progressive disease (12.6 ± 5.7 ng/mL) compared to those with stable disease (mean 21.5 ± 8.2 ng/mL, p = 0.001) or tumor free after surgery (19.6 ± 7.3 ng/mL, p = 0.002). Patients with vitamin D deficiency and insufficiency had shorter progression-free survival compared to those with sufficiency (p = 0.014), whereas no correlation was found with disease-specific survival. Conclusions: Vitamin D deficiency is highly prevalent among GEP-NETs and could be associated with high tumor grade and disease progression. Therefore, the monitoring of 25(OH)D levels is relevant in these patients and vitamin D supplementation should be considered in the management of GEP-NET patients with vitamin D deficiency or insufficiency
Impact of the MTHFR C677T polymorphism on one-carbon metabolites: Evidence from a randomised trial of riboflavin supplementation
Homozygosity for the C677T polymorphism in MTHFR (TT genotype) is associated with a 24–87% increased risk of hypertension. Blood pressure (BP) lowering was previously reported in adults with the TT genotype, in response to supplementation with the MTHFR cofactor, riboflavin. Whether the BP phenotype associated with the polymorphism is related to perturbed one-carbon metabolism is unknown. This study investigated one-carbon metabolites and their responsiveness to riboflavin in adults with the TT genotype. Plasma samples from adults (n 115) screened for the MTHFR genotype, who previously participated in RCTs to lower BP, were analysed for methionine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), betaine, choline and cystathionine by liquid chromatography tandem mass spectrometry (LC-MS/MS). The one-carbon metabolite response to riboflavin (1.6 mg/d; n 24) or placebo (n 23) for 16 weeks in adults with the TT genotype was also investigated. Plasma SAM (74.7 ± 21.0 vs 85.2 ± 22.6 nmol/L, P = 0.013) and SAM:SAH ratio (1.66 ± 0.55 vs 1.85 ± 0.51, P = 0.043) were lower and plasma homocysteine was higher (P = 0.043) in TT, compared to CC individuals. In response to riboflavin, SAM (P = 0.008) and cystathionine (P = 0.045) concentrations increased, with no responses in other one-carbon metabolites observed. These findings confirm perturbed one-carbon metabolism in individuals with the MTHFR 677TT genotype, and for the first time demonstrate that SAM, and cystathionine, increase in response to riboflavin supplementation in this genotype group. The genotype-specific, one-carbon metabolite responses to riboflavin intervention observed could offer some insight into the role of this gene-nutrient interaction in blood pressure
Outbreak of sars-cov-2 lineage 20i/501y.V1 in a nursing home underlines the crucial role of vaccination in both residents and staff
Elderly residents in nursing homes are at very high risk of life-threatening COVID-19-related outcomes. In this report, an epidemiological and serological investigation of a SARS-CoV-2 outbreak in an Italian nursing home is described. Among the residents, all but one (19/20) were regularly vaccinated against SARS-CoV-2. In mid-February 2021, a non-vaccinated staff member of the nursing home was diagnosed with the SARS-CoV-2 infection. Following the outbreak investigation, a total of 70% (14/20) of residents aged 77–100 years were found positive. The phylogenetic analysis showed that the outbreak was caused by the SARS-CoV-2 variant of concern 202012/01 (the so-called “UK variant”). However, all but one positive subjects (13/14) were fully asymptomatic. The only symptomatic patient was a vaccinated 86-year-old female with a highly compromised health background and deceased approximately two weeks later. The subsequent serological investigation showed that the deceased patient was the only vaccinated subject that did not develop the anti-spike protein antibody response, therefore being likely a vaccine non-responder. Although the available mRNA SARS-CoV-2 vaccine was not able to prevent several asymptomatic infections, it was able to avert most symptomatic disease cases caused by the SARS-CoV-2 variant of concern 202012/01 in nursing home residents
Generalized Arcsine Law and Stable Law in an Infinite Measure Dynamical System
Limit theorems for the time average of some observation functions in an
infinite measure dynamical system are studied. It is known that intermittent
phenomena, such as the Rayleigh-Benard convection and Belousov-Zhabotinsky
reaction, are described by infinite measure dynamical systems.We show that the
time average of the observation function which is not the function,
whose average with respect to the invariant measure is finite, converges to
the generalized arcsine distribution. This result leads to the novel view that
the correlation function is intrinsically random and does not decay. Moreover,
it is also numerically shown that the time average of the observation function
converges to the stable distribution when the observation function has the
infinite mean.Comment: 8 pages, 8 figure
positive predictive value for malignancy on surgical excision of breast lesions of uncertain malignant potential b3 diagnosed by stereotactic vacuum assisted needle core biopsy vancb a large multi institutional study in italy
Abstract Percutaneous core biopsy (CB) has been introduced to increase the ability of accurately diagnosing breast malignancies without the need of resorting to surgery. Compared to conventional automated 14 gauge needle core biopsy (NCB), vacuum-assisted needle core biopsy (VANCB) allows obtaining larger specimens and has recognized advantages particularly when the radiological pattern is represented by microcalcifications. Regardless of technical improvements, a small percentage of percutaneous CBs performed to detect breast lesions are still classified, according to European and UK guidelines, in the borderline B3 category, including a group of heterogeneous lesions with uncertain malignant potential. We aimed to assess the prevalence and positive predictive values (PPV) on surgical excision (SE) of B3 category (overall and by sub-categories) in a large series of non-palpable breast lesions assessed through VANCB, also comparison with published data on CB. Overall, 26,165 consecutive stereotactic VANCB were identified in 22 Italian centres: 3107 (11.9%) were classified as B3, of which 1644 (54.2%) proceeded to SE to establish a definitive histological diagnosis of breast pathology. Due to a high proportion of microcalcifications as main radiological pattern, the overall PPV was 21.2% (range 10.6%–27.3% for different B3 subtypes), somewhat lower than the average value (24.5%) from published studies (range 9.9%–35.1%). Our study, to date the largest series of B3 with definitive histological assessment on SE, suggests that B3 lesions should be referred for SE even if VANCB is more accurate than NCB in the diagnostic process of non-palpable, sonographically invisible breast lesions
Emerging therapies in pheochromocytoma and paraganglioma: Immune checkpoint inhibitors in the starting blocks
Pheochromocytoma and paraganglioma are neuroendocrine neoplasms, originating in the adrenal medulla and in parasympathetic and sympathetic autonomic nervous system ganglia, respec-tively. They usually present as localized tumours curable with surgery. However, these tumours may exhibit heterogeneous clinical course, ranging from no/minimal progression to aggressive (progres-sive/metastatic) behavior. For this setting of patients, current therapies are unsatisfactory. Immune checkpoint inhibitors have shown outstanding results for several types of solid cancers. We therefore aimed to summarize and discuss available data on efficacy and safety of current FDA-approved immune checkpoint inhibitors in patients with pheochromocytoma and paraganglioma. After an extensive search, we found 15 useful data sources (four full-published articles, four supplements of scientific journals, seven ongoing registered clinical trials). The data we detected, even with the limit of the small number of patients treated, make a great expectation on the therapeutic use of immune checkpoint inhibitors. Besides, the newly detected predictors of response will (hopefully) be of great helps in selecting the subset of patients that might benefit the most from this class of drugs. Finally, new trials are in the starting blocks, and they are expected to shed in the next future new light on a therapy, which is considered a milestone in oncology
A geo-chemo-mechanical study of a highly polluted marine system (Taranto, Italy) for the enhancement of the conceptual site model
The paper presents the results of the analysis of the geo-chemo-mechanical data gathered through an innovative multidisciplinary investigation campaign in the Mar Piccolo basin, a heavily polluted marine bay aside the town of Taranto (Southern Italy). The basin is part of an area declared at high environmental risk by the Italian government. The cutting-edge approach to the environmental characterization of the site was promoted by the Special Commissioner for urgent measures of reclamation, environmental improvements and redevelopment of Taranto and involved experts from several research fields, who cooperated to gather a new insight into the origin, distribution, mobility and fate of the contaminants within the basin. The investigation campaign was designed to implement advanced research methodologies and testing strategies. Differently from traditional investigation campaigns, aimed solely at the assessment of the contamination state within sediments lying in the top layers, the new campaign provided an interpretation of the geo-chemo-mechanical properties and state of the sediments forming the deposit at the seafloor. The integrated, multidisciplinary and holistic approach, that considered geotechnical engineering, electrical and electronical engineering, geological, sedimentological, mineralogical, hydraulic engineering, hydrological, chemical, geochemical, biological fields, supported a comprehensive understanding of the influence of the contamination on the hydro-mechanical properties of the sediments, which need to be accounted for in the selection and design of the risk mitigation measures. The findings of the research represent the input ingredients of the conceptual model of the site, premise to model the evolutionary contamination scenarios within the basin, of guidance for the environmental risk management. The study testifies the importance of the cooperative approach among researchers of different fields to fulfil the interpretation of complex polluted eco-systems
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