Low- to high-velocity frictional properties of the clay-rich gouges from the slipping zone of the 1963 Vaiont slide, northern Italy

The final slip of about 450 m at about 30 m/s of the 1963 Vaiont landslide (Italy) was preceded by >3 year long creeping phase which was localized in centimeter-thick clay-rich layers (60–70% smectites, 20–30% calcite and quartz). Here we investigate the frictional properties of the clay-rich layers under similar deformation conditions as during the landslide: 1–5 MPa normal stress, 2 × 10^(−7) to 1.31 m/s slip rate and displacements up to 34 m. Experiments were performed at room humidity and wet conditions with biaxial, torsion and rotary shear apparatus. The clay-rich gouge was velocity-independent to velocity-weakening in both room humidity and wet conditions. In room humidity experiments, the coefficient of friction decreased from 0.47 at v 0.70 m/s: full lubrication results from the formation of a continuous water film in the gouge. The Vaiont landslide occurred under wet to saturated conditions. The unstable behavior of the landslide is explained by the velocity-weakening behavior of the Vaiont clay-rich gouges. The formation of a continuous film of liquid water in the slipping zone reduced the coefficient of friction to almost zero, even without invoking the activation of thermal pressurization. This explains the extraordinary high velocity achieved by the slide during the final collapse

Improving basic skills in celiac-like disease diagnosis. A case report

Background: The diagnosis of Coeliac disease (CD) requires a combination of sign/symptoms, positivity of specific antibodies and duodenal histological evidence of villous atrophy. Duodenal villous atrophy, despite representing the CD landmark, is not specific since it is found in many gastrointestinal disorders. Giardiasis is one of the most common human intestinal protozoan infestations in industrialized countries whose histological duodenal mucosa damage could mimic that of CD. The present report shows how a wise clinical and laboratory assessment led us shortly to a correct diagnosis. Case presentation: A 42-year-old outpatient woman without previous significant gastrointestinal diseases, was referred with dyspeptic symptoms, fatigue and mild diarrhea from 4 months. Her first investigations including immunoglobulin A (IgA) anti-tissue transglutaminase antibodies (anti-tTG) and stool parasitological and cultural analysis were negative. An esophagogastroduodenoscopy (EGDS) showed no mucosal alteration. But histology demonstrated a Helicobacter Pylori (HP) pan-gastritis while duodenal mucosa showed villous atrophy consistent with a diagnosis of CD Marsh type 3b. While on gluten-free diet (GFD) the patient didn't experience any improvement of symptoms. Duodenal biopsies were then reviewed showing the presence of trophozoites of Giardia on the luminal surface of the duodenal wall and at the same time, a second stool examination revealed the presence of trophozoites and cysts of Giardia. Treated with metronidazole, 500 mg twice daily for 6 days the patient reduced diarrhea after few days. After about 2 months of GFD she was invited to discontinue it. At the same time stool examination was repeated with negative results. She subsequently performed eradication for Hp with triple therapy (Pylera®). Around 6 months later, the patient did not complain any gastrointestinal symptoms. Serological tests were normal and at a follow-up EGDS, duodenal mucosa had normal histology with normal finger-like villi and absence of Giardia trophozoites. Conclusion: This case report shows how CD diagnosis can sometimes be manifold. Intestinal villous atrophy alone may not automatically establish a diagnosis of CD. In the present case the clinical scenario could be fully explained by giardiasis. Indeed, different diagnostic tools and a multi-step approaches have been used to determine the final correct diagnosis

Therapeutic Ultrasound as a Potential Male Dog Contraceptive: Determination of the Most Effective Application Protocol

Contents: Ultrasound is one of the most promising forms of non-invasive contraception and has been studied in several animal models. The objective of the current investigation was to determine the most practical and effective application protocol for dog sterilization. A total of 100 dogs were divided into five equal groups. Group A received 5-min applications three times performed at 48-hr intervals and covering the entire testicular area at frequency of 1 MHz; Group B received 5-min applications three times performed at 48-hr intervals over the dorso-cranial area of the testis at frequency of 3 MHz; Group C received three sequential 5-min applications (at 5-min intervals between applications) covering the entire testicular area at frequency of 1 MHz; Group D received 15-min applications two times performed at 48-hr intervals and covering the entire testicular area at frequency of 1 MHz. The experimental groups' ultrasound had an intensity of 1.5W/cm2. The Control Group had the same procedure as Group A, but with the transducer switched-off. Dogs were surgically castrated 40 days following the treatment for histological examination. Azoospermia, testicular volume reduction and apparently irreversible testicular damage were achieved by Group A. No effects were noticed in the other groups. Testosterone levels remained within physiological range with all application protocols. A regimen of three applications of ultrasound at 1 MHz, and 1.5 W/cm2, lasting 5 min with an interval of 48 h was effective as permanent sterilization in the dog without hormonal impact

Big-data-driven modeling unveils country-wide drivers of endemic schistosomiasis

Schistosomiasis is a parasitic infection that is widespread in sub-Saharan Africa, where it represents a major health problem. We study the drivers of its geographical distribution in Senegal via a spatially explicit network model accounting for epidemiological dynamics driven by local socioeconomic and environmental conditions, and human mobility. The model is parameterized by tapping several available geodatabases and a large dataset of mobile phone traces. It reliably reproduces the observed spatial patterns of regional schistosomiasis prevalence throughout the country, provided that spatial heterogeneity and human mobility are suitably accounted for. Specifically, a fine-grained description of the socioeconomic and environmental heterogeneities involved in local disease transmission is crucial to capturing the spatial variability of disease prevalence, while the inclusion of human mobility significantly improves the explanatory power of the model. Concerning human movement, we find that moderate mobility may reduce disease prevalence, whereas either high or low mobility may result in increased prevalence of infection. The effects of control strategies based on exposure and contamination reduction via improved access to safe water or educational campaigns are also analyzed. To our knowledge, this represents the first application of an integrative schistosomiasis transmission model at a whole-country scale

Education differentiates cognitive performance and resting state fMRI connectivity in healthy aging

ObjectivesIn healthy aging, the way people cope differently with cognitive and neural decline is influenced by exposure to cognitively enriching life-experiences. Education is one of them, so that in general, the higher the education, the better the expected cognitive performance in aging. At the neural level, it is not clear yet how education can differentiate resting state functional connectivity profiles and their cognitive underpinnings. Thus, with this study, we aimed to investigate whether the variable education allowed for a finer description of age-related differences in cognition and resting state FC.MethodsWe analyzed in 197 healthy individuals (137 young adults aged 20–35 and 60 older adults aged 55–80 from the publicly available LEMON database), a pool of cognitive and neural variables, derived from magnetic resonance imaging, in relation to education. Firstly, we assessed age-related differences, by comparing young and older adults. Then, we investigated the possible role of education in outlining such differences, by splitting the group of older adults based on their education.ResultsIn terms of cognitive performance, older adults with higher education and young adults were comparable in language and executive functions. Interestingly, they had a wider vocabulary compared to young adults and older adults with lower education. Concerning functional connectivity, the results showed significant age- and education-related differences within three networks: the Visual-Medial, the Dorsal Attentional, and the Default Mode network (DMN). For the DMN, we also found a relationship with memory performance, which strengthen the evidence that this network has a specific role in linking cognitive maintenance and FC at rest in healthy aging.DiscussionOur study revealed that education contributes to differentiating cognitive and neural profiles in healthy older adults. Also, the DMN could be a key network in this context, as it may reflect some compensatory mechanisms relative to memory capacities in older adults with higher education

The spatial spread of schistosomiasis: A multidimensional network model applied to Saint-Louis region, Senegal

AbstractSchistosomiasis is a parasitic, water-related disease that is prevalent in tropical and subtropical areas of the world, causing severe and chronic consequences especially among children. Here we study the spatial spread of this disease within a network of connected villages in the endemic region of the Lower Basin of the Senegal River, in Senegal. The analysis is performed by means of a spatially explicit metapopulation model that couples local-scale eco-epidemiological dynamics with spatial mechanisms related to human mobility (estimated from anonymized mobile phone records), snail dispersal and hydrological transport of schistosome larvae along the main water bodies of the region. Results show that the model produces epidemiological patterns consistent with field observations, and point out the key role of spatial connectivity on the spread of the disease. These findings underline the importance of considering different transport pathways in order to elaborate disease control strategies that can be effective within a network of connected populations

Effects of post cure treatment in the glass transformation range on the structure and fire behavior of in situ generated siilica/epoxy hybrids

A new "in situ” sol–gel synthesis procedure was exploited to produce silica/epoxy nanocomposites with 6 wt.% maximum silica content. 3-Aminopropyltriethoxysilane (APTS) was used as a coupling agent. The experimental results (fourier- transform infrared spectroscopy, FTIR, small-angle X-ray scattering, SAXS, transmission electron microscopy, TEM, nuclear magnetic resonance, NMR, and dynamic mechanical analysis, DMA) support that the structure consists of nanosized silica particles (maximum 1.25 nm in size) embedded in a hybrid co-continuous network. A post cure non-isothermal heating from 15 to 100 °C (beyond the Tg of the neat epoxy) caused Tg and storage modulus to increase. The fire behavior, that, owing to severe regulations (i.e., in aerospace engineering), often prevents composites applications, was also studied. The formed silica domains prevented melt dripping phenomena during vertical flame spread tests. Cone calorimetry tests showed a remarkable decrease of the heat release rate (HRR) for all the hybrid systems with respect to the neat cured resin, even at very low silica loadings (i.e., 2 wt.%). This decrease was much more pronounced for the hybrid structures that were not subjected to the post cure thermal treatment. The use of multiple structural investigation techniques allowed to choose among multiple hypothesis and conclude that nanoparticles clustering is the main reason of the effects of the post curing treatments

Statistics of non-linear stochastic dynamical systems under L\'evy noises by a convolution quadrature approach

This paper describes a novel numerical approach to find the statistics of the non-stationary response of scalar non-linear systems excited by L\'evy white noises. The proposed numerical procedure relies on the introduction of an integral transform of Wiener-Hopf type into the equation governing the characteristic function. Once this equation is rewritten as partial integro-differential equation, it is then solved by applying the method of convolution quadrature originally proposed by Lubich, here extended to deal with this particular integral transform. The proposed approach is relevant for two reasons: 1) Statistics of systems with several different drift terms can be handled in an efficient way, independently from the kind of white noise; 2) The particular form of Wiener-Hopf integral transform and its numerical evaluation, both introduced in this study, are generalizations of fractional integro-differential operators of potential type and Gr\"unwald-Letnikov fractional derivatives, respectively.Comment: 20 pages, 5 figure

Aspetti della biologia ed analisi del ciclo riproduttivo di Gobio benacensis (Pollini, 1816) nel Nordest Italia

Il presente studio si propone di approfondire la biologia ed il ciclo riproduttivo del gobione italiano (Gobio benacensis), specie endemica a corologia cisalpina inclusa nella categoria \u201cEndangered\u201d (EN) della lista rossa IUCN, con l\u2019intento di fornire informazioni utili a redigere corretti piani gestionali volti alla conservazione della specie. Le indagini sono state condotte in un corso d\u2019acqua del Bacino del Fiume Isonzo (Torrente Reca, Nordest Italia) ed hanno riguardato 86 esemplari catturati nell\u2019aprile 2016 al fine di definirne la consistenza e la struttura della popolazione e 77 esemplari, catturati mensilmente e bimestralmente tra aprile 2016 e febbraio 2017, per la definizione del ciclo riproduttivo. Le curve di regressione del peso sulla lunghezza totale per i maschi (W=0,1253TL2,8770) e per le femmine (W=0,1555TL2,7554), confrontate mediante ANCOVA, non hanno denunciato differenze significative. I valori medi \ub1 deviazione standard dell\u2019indice gonadosomatico GSI per i maschi sono compresi tra 0,61\ub10,49 e 1,75\ub10,58, mentre per le femmine tra 1,02\ub10,88 e 14,15\ub12,80. L\u2019indice epatosomatico HSI ha denunciato range compresi tra 0,05\ub10,02 e 2,68\ub11,26 e tra 0,25\ub10,19 e 1,75\ub10,58 rispettivamente per i maschi e per le femmine. Le analisi istologiche di ovari e testicoli, analizzati per la prima volta nella specie, hanno permesso di identificare gli stadi di maturazione, che unitamente all\u2019analisi del GSI indicano che la specie depone le uova a pi\uf9 riprese durante il periodo riproduttivo compreso tra aprile e giugno. Nei maschi \ue8 stata, tuttavia, evidenziata una prolungata attivit\ue0 riproduttiva che si protrae fino al mese di agosto