Holocene slip rate variability along the Pernicana fault system (Mt. Etna, Italy): Evidence from offset lava flows

The eastern flank of the Mount Etna stratovolcano is affected by extension and is slowly sliding eastward into the Ionian Sea. The Pernicana fault system forms the border of the northern part of this sliding area. It consists of three E-W−oriented fault sectors that are seismically active and characterized by earthquakes up to 4.7 in magnitude (M) capable of producing ground rupture and damage located mainly along the western and central sectors, and by continuous creep on the eastern sector. A new topographic study of the central sector of the Pernicana fault system shows an overall bell-shaped profile, with maximum scarp height of 35 m in the center of the sector, and two local minima that are probably due to the complex morphological relation between fault scarp and lava flows. We determined the ages of lava flows cut by the Pernicana fault system at 12 sites using cosmogenic 3He and 40Ar/39Ar techniques in order to determine the recent slip history of the fault. From the displacement-age relations, we estimate an average throw rate of ∼2.5 mm/yr over the last 15 k.y. The slip rate appears to have accelerated during the last 3.5 k.y., with displacement rates of up to ∼15 mm/yr, whereas between 3.5 and 15 ka, the throw rate averaged ∼1 mm/yr. This increase in slip rate resulted in significant changes in seismicity rates, for instance, decreasing the mean recurrence time of M ≥ 4.7 earthquakes from ∼200 to ∼20 yr. Based on empirical relationships, we attribute the variation in seismic activity on the Pernicana fault system to factors intrinsic to the system that are likely related to changes in the volcanic system. These internal factors could be fault interdependencies (such as those across the Taupo Rift, New Zealand) or they could represent interactions among magmatic, tectonic, and gravitational processes (e.g., Kīlauea volcano, Hawaii). Given their effect on earthquake recurrence intervals, these interactions need to be fully assessed in seismic hazard evaluations

Solvent-Free Synthetic Route for Cerium(IV) Metal–Organic Frameworks with UiO-66 Architecture and Their Photocatalytic Applications

A near solvent-free synthetic route for Ce-UiO-66 metal–organic frameworks (MOFs) is presented. The MOFs are obtained by energetically grinding the reagents, cerium ammonium nitrate (CAN) and the carboxylic linkers, in a mortar for a few minutes with the addition of a small amount of acetic acid (AcOH) as a modulator (8.75 equiv, 0.5 mL). The slurry is then transferred into a 2 mL vial and heated at 120 °C for 1 day. The MOFs have been characterized for their composition, crystallinity, and porosity and employed as heterogeneous catalysts for the photo-oxidation reaction of substituted benzylic alcohols to benzaldaldehydes under near-ultraviolet light irradiation. The catalytic performances, such as selectivity, conversion, and kinetics, exceed those of similar systems studied by chemical oxidation using similar Ce-MOFs as a catalyst. Moreover, the MOFs were found to be reusable up to three cycles without loss of activity. Density functional theory (DFT) calculations were used to fully describe the electronic structure of the best performing MOFs and to provide useful information on the catalytic activity experimentally observed

Key Ergonomics Requirements and Possible Mechanical Solutions for Augmented Reality Head-Mounted Displays in Surgery

In the context of a European project, we identified over 150 requirements for the development of an augmented reality (AR) head-mounted display (HMD) specifically tailored to support highly challenging manual surgical procedures. The requirements were established by surgeons from different specialties and by industrial players working in the surgical field who had strong commitments to the exploitation of this technology. Some of these requirements were specific to the project, while others can be seen as key requirements for the implementation of an efficient and reliable AR headset to be used to support manual activities in the peripersonal space. The aim of this work is to describe these ergonomic requirements that impact the mechanical design of the HMDs, the possible innovative solutions to these requirements, and how these solutions have been used to implement the AR headset in surgical navigation. We also report the results of a preliminary qualitative evaluation of the AR headset by three surgeons

Quinupristin/dalfopristin Bonding in Combination with Intraperitoneal Antibiotics Prevent Infection of Knitted Polyester Graft Material in a Subcutaneous Rat Pouch Model Infected with Resistant Staphylococcus epidermidis

AbstractObjective: to investigate the efficacy of quinupristin/dalfopristin in the prevention of prosthetic graft infection in a rat subcutaneous pouch model.Methods: graft infections were established in the subcutaneous tissue of 140 male Wistar rats by implantation of Dacron prostheses followed by topical inoculation withStaphylococcus epidermidis with intermediate resistance to glycopeptides. The study included one group without contamination, one contaminated group without prophylaxis, one contaminated group that received 50mg/l quinupristin/dalfopristin-soaked graft, one contaminated group that received 10mg/kg intraperitoneal levofloxacin, one contaminated group that received 3mg/kg intraperitoneal doxycycline, and two contaminated groups that received 50mg/l quinupristin/dalfopristin-soaked plus 10mg/kg intraperitoneal levofloxacin or 3mg/kg intraperitoneal doxycycline. Each group included 20 animals. The grafts were removed after 7 days and evaluated by quantitative culture.Results: quinupristin/dalfopristin showed a significantly higher efficacy than levofloxacin and doxycycline, even though quantitative graft cultures for rats that received only quinupristin/dalfopristin-soaked graft showed bacterial growth. Otherwise, the efficacy of levofloxacin was similar to that of doxycycline. Only the group treated with quinupristin/dalfopristin combined with levofloxacin or doxycycline showed no evidence of staphylococcal infection.Conclusions: quinupristin/dalfopristin as adjunctive topical antibiotic prophylaxis can be useful for the prevention of vascular graft infections caused by staphylococcal strains with high levels of resistance

relation between ribosomal rna genes and the dna satellites of phaseolus coccineus

The main band DNA of Phaseolus coccineus has a buoyant density of 1.692 g/ml. In roots, shoots, integuments and suspensors there is a DNA satellite with a buoyant density of 1.700 g/ml. The satellite of the roots, shoots and integuments represents approximately 28.2 %, 29.4 % and 34.7 % respectively of the total DNA. In suspensors, where polyteny occurs, besides the 1.700 g/ml satellite there is a second one at 1.696 g/ml. They represent about 32.9 % and 13.1 % of the total DNA. H3-25S and H3-18S ribosomal RNA of Phaseolus coccineus were hybridized separately with DNA of shoots from CsCl gradient fractions. In both hybridizations the peak of labelling coincides with the position of the DNA satellite with a buoyant density of 1.700 g/ml. Thus the genes for 25S and 18S are mainly located in this DNA component. Hybridization experiments at saturation inputs of H3-25S ribosomal RNA with DNA of shoots, integuments, roots and suspensors give saturation values of 0.72 %, 0.64 %, 0.51 % and 0.42 % respectively. The lower saturation value in the suspensors may indicate an underreplication of ribosomal genes in this tissue. This is partly cancelled out by the amplification in another DNA: that of the second satellite at 1.696 g/ml which does not seem to be part of the ribosomal DNA

RNAIII-inhibiting Peptide and/or Nisin Inhibit Experimental Vascular Graft Infection with Methicillin-susceptible and Methicillin-resistant Staphylococcus epidermidis

AbstractObjective. To investigate the efficacy of RNAIII-inhibiting peptide (RIP) and nisin as prophylactic agents in a rat model of vascular graft infection.Design. Prospective, randomized, controlled animal study.Materials. Two hundred and twenty adult male Wistar rats. Staphylococcus epidermidis ATCC 12228 and one clinical isolate of methicillin-resistant S. epidermidis. Drugs: RIP, nisin and rifampin.Methods. Graft infections were established in the dorsal subcutaneous tissue by implantation of 1 cm2 sterile Dacron grafts, followed by topical bacterial inoculation: grafts were retrieved at 7 days. The study included a control group (without inoculation) and two series composed of five groups for each staphylococcal strain: one contaminated group that did not receive any antibiotic prophylaxis, three contaminated groups that received grafts soaked with 10 mg/l RIP, 10 mg/l nisin, 10 mg/l rifampin, or RIP+nisin. The main outcome measure was the extent of bacterial at graft harvest.Results. The bacterial counts for methicillin-resistant S. epidermidis on explanted grafts were 6.1±2.8×102, 7.8±3.0×103 and 5.5±2.9×104 for RIP, nisin and rifampin, respectively. RIP and nisin used in combination reduced the bacterial count to <10. The results for S. epidermidis were similar.Conclusions. RIP and nisin could be used in combination to coat medical devices to prevent drug resistant S. epidermidis infections

hedgehog pathway influence in the immune escape of tumor cells through pdl 1 modulation

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Rapid evolution of female-biased genes among four species of Anopheles malaria mosquitoes.

Understanding how phenotypic differences between males and females arise from the sex-biased expression of nearly identical genomes can reveal important insights into the biology and evolution of a species. Among Anopheles mosquito species, these phenotypic differences include vectorial capacity, as it is only females that blood feed and thus transmit human malaria. Here, we use RNA-seq data from multiple tissues of four vector species spanning the Anopheles phylogeny to explore the genomic and evolutionary properties of sex-biased genes. We find that, in these mosquitoes, in contrast to what has been found in many other organisms, female-biased genes are more rapidly evolving in sequence, expression, and genic turnover than male-biased genes. Our results suggest that this atypical pattern may be due to the combination of sex-specific life history challenges encountered by females, such as blood feeding. Furthermore, female propensity to mate only once in nature in male swarms likely diminishes sexual selection of post-reproductive traits related to sperm competition among males. We also develop a comparative framework to systematically explore tissue- and sex-specific splicing to document its conservation throughout the genus and identify a set of candidate genes for future functional analyses of sex-specific isoform usage. Finally, our data reveal that the deficit of male-biased genes on the X Chromosomes in Anopheles is a conserved feature in this genus and can be directly attributed to chromosome-wide transcriptional regulation that de-masculinizes the X in male reproductive tissues

Silicon nanoparticles as active materials for LED: laser synthesis and functionalization for tuning luminescence

Silicon nanocrystals (SiNPs) are an extensively studied light-emitting material due to their inherent biocompatibility and easy integration with silicon-based technology. Although low luminescence quantum yields of as-prepared SiNPs, the exploitation of the surface chemistry of SiNPs plays a key role in tuning their luminescence. In this work, the development of SiNPs as active materials for innovative LEDs was investigated. SiNPs were synthesized by using laser pyrolysis, a very flexible tool for lab-scale production in developmental quantities. The synthesized SiNPs have dimensions from 5 to 15 nm and high purity grade but show weak luminescence. For this reason, chemical treatments were performed on SiNPs: surface modifications lead to an improvement of their luminescence properties. Chemical and optical characterization were performed by conventional and advanced techniques, such as FTIR, BET, UV-VIS absorption and emission, XPS, TEM and confocal Raman. A Life Cycle Assessment (LCA) study of laser synthesis of SiNPs was conducted with the aim to identify the potential environmental impacts coming from this production method