Nonlinear diffusion model for Rayleigh-Taylor mixing

The complex evolution of turbulent mixing in Rayleigh-Taylor convection is studied in terms of eddy diffusiviy models for the mean temperature profile. It is found that a non-linear model, derived within the general framework of Prandtl mixing theory, reproduces accurately the evolution of turbulent profiles obtained from numerical simulations. Our model allows to give very precise predictions for the turbulent heat flux and for the Nusselt number in the ultimate state regime of thermal convection.Comment: 4 pages, 4 figure, PRL in pres

ORAL LESIONS DUE TO ACINETOBACTER BAUMANNII INFECTION IN A PATIENT AFFECTED BY AUTOIMMUNE HEMOLYTIC ANEMIA (AIHA): FIRST CLINICAL REPORT

Aim. Acinetobacter Baumannii (coming from the Greek “akinetos,” i.e. non-motile) is an opportunistic bacterial pathogen primarily associated with hospital-acquired infections. Commonly associated with aquatic environments, A. Baumannii easily contaminates the surrounding environment and it colonizes acute ill patients in which can survive for several days. Generally, A. Baumannii is able to damage mucous membranes or exposed skin after accident or injury; it may be responsible of many diseases such as pneumonia, bacteremia, meningitis, urinary tract infections, peritonitis and infections of skin and soft tissues. Tissues infected by A. Baumannii initially present “orange peel” appearance followed by sandpaper-like presentation, when there is a disruption, hemorrhagic bullae can be seen with a visible necrotizing process followed by bacteremia. Current therapy is based on intravenous administration of tigecycline 100-200 mg (first dose) and 50-100 mg every 12 h for up to 14 days, unless complications. If untreated, this infection can lead to septicemia and death. The mortality rate of this infection is high, especially in case of bacteremia (52%) and pneumonia (23–73%). A. Baumannii is resistant to many drugs and represents an important nosocomial pathogen that particularly infects critically ill patients. At the best of our knowledge, no case of oral infection has been reported. to present the first one case characterized by oral soft tissue infection due to A. Baumannii responsive to imipenem. Materials and methods. a 78 years male was hospitalized in August of 2013 at the Hematology unit of the A.O.U.P. “P. Giaccone” of Palermo with a diagnosis of autoimmune hemolytic anemia (AIHA). He was treated per os with corticosteroids (Prednisone) and immunosuppressants (Rituximab and Cyclophosphamide), also IVIG (Intra Venous Immuno-Globulin) was administreted. In November 2013, the patient was treated with piperacillin IV (Tazocin) for treating an urinary tract infection; four days after, multiple oral ulcerative bullous lesions on the lingual and buccal mucosa and crusted lesions on the lip vermilion appeared, associated with intense pain. An oral swab for bacteria research was carried out; topical therapy (chlorhexidine rinses and hyaluronic acid gel) has been prescribed and piperacillin therapy was stopped. Oral swab outcome resulted positive for A. Baumannii and Enterococcus Faecalis, both sensitive only to imipenem, that was administrated (500 mg IV every 8h) for 10 days. The patient was immediately isolated in a single room for preventing and controlling the spread of A. Baumannii. Results. From diagnosis, every 3 days clinical examination of the oral cavity was performed, revealing the progressive regression within thirty days until complete healing without leaving scars. After, a second oral swab confirmed the absence of any bacteria. Conclusions. The World Health Organization has recently identified antimicrobial resistance as one of the three most important problems facing human health and among the most common and serious pathogens, including A. Baumannii. It is an emerging potentially drug-resistant micro-organism and its isolation must alert physicians to carry on all preventive measures for avoiding contamination of other patients, especially those immunosuppressed, at risk for severe persistent infections or death. This precaution should be continued for all the duration of hospitalization and until the negativization of culture samples was obtained. It is important that physicians and dentists recognize suspicious lesions in unusual locations, such as oral mucosa, in absence of other known etiological factors in a timely manner before the diffusion among other patients in order to avoid the spread of a nosocomial outbreak

Preliminary bioassays on the susceptibility of stone fruits rootstocks to Capnodis tenebrionis (L.).

Capnodis tenebrionis (L.) (Coleoptera: Buprestidae), the so called Mediterranean flat-headed root-borer, is an economically important phytophagous pest species mainly on stone fruit trees (apricot, plum, cherry, peach and nectarine). Chemicals and Entomopathogenic nematodes are used for the control of adults and neonate larvae, respectively. Further control means are under investigations in order to have more options within Integrated Pest Control strategies. This study is aimed at investigating the susceptibility of rootstocks to the larvae of C. tenebrionis. Two bioassays were carried out during 2016 and 2017. A first bioassay was based on the evaluation of a potential antixenosis action expressed by neonate larvae infesting twigs of rootstocks (Marianna 26, Barrier, Adesoto, Mylaboran 29C, GF677, Garnem, Cab 6P, Max Ma60 and Colt). This bioassay allowed to process a high number of different rootstocks in a short time. It has a preliminary value. The second bioassay assessed the antibiosis influence of the rootstocks through the breeding of larvae (since the neonate ones) on artificial diets containing bark flour of Adesoto, Cab 6P, Colt, Garnem, GF677, Max Ma60, Montclar and 29C rootstock. The first bioassay showed that Colt, Mylaboran 29C and GF677 were the most susceptible rootstocks to larval infestation of C. tenebrionis and Max Ma60 was less favorable to the pest. Concerning the effects of the diet, larvae reared on a diet containing Montclar, Cab 6P and GF 677 bark flour had a mean daily increase of their weight higher that those reared on cortex tissues of other genotypes whereas Garnem and Colt had a lower increase

Probing Ensemble Properties of Vortex-avalanche Pulsar Glitches with a Stochastic Gravitational-Wave Background Search

A stochastic gravitational-wave background (SGWB) is expected to be produced by the superposition of individually undetectable, unresolved gravitational-wave (GW) signals from cosmological and astrophysical sources. Such a signal can be searched with dedicated techniques using the data acquired by a network of ground-based GW detectors. In this work, we consider the astrophysical SGWB resulting from pulsar glitches, which are sudden increases in the rotational pulsar frequency, within our Galaxy. More specifically, we assume glitches to be associated with quantized, superfluid, vortex-avalanches in the pulsars, and we model the SGWB from the superposition of GW bursts emitted during the glitching phase. We perform a cross-correlation search for this SGWB-like signal employing the data from the first three observation runs of Advanced LIGO and Virgo. Not having found any evidence for a SGWB signal, we set upper limits on the dimensionless energy density parameter $\Omega_{\mathrm{gw}}(f)$ for two different power-law SGWBs, corresponding to two different glitch regimes. We obtain $\Omega_{\mathrm{gw}}(f)\leq 7.5 \times 10^{-10}$ at 25 Hz for a spectral index 5/2, and $\Omega_{\mathrm{gw}}(f)\leq 5.7 \times 10^{-17}$ at 25 Hz for a spectral index 17/2. We then use these results to set constraints on the average glitch duration and the average radial motion of the vortices during the glitches for the population of the glitching Galactic pulsars, as a function of the Galactic glitch rate.Comment: 16 pages, 3 figures, 1 tabl

RESTITUTIO AD INTEGRUM IN A CASE OF ONJ RELATED TO BEVACIZUMAB

Aim. Bevacizumab is a humanized recombinant monoclonal antibody that blocks vascular endothelial growth factor (VEGF). The activity of VEGF is the ability to promote the vascular endothelial cells proliferation inducing the formation of new blood vessels. Bevacizumab is used in the treatment of selected advanced colon, lung, renal and central nervous system tumours and plays a developing role in the management of breast and ovarian cancers. It is also injected intraocularly for treatment of macular degeneration. Recently, bevacizumab has been reported as responsible of drug-related osteonecrosis of the jaw (ONJ), showing a histological pattern similar to bisphosphonate-related ONJ. Moreover, it may increase the risk for osteonecrosis of the jaw when administered in isolation or when given concurrently with bisphosphonates. Materials and methods. Only few case reports in literature have been reported describing ONJ after bevacizumab administration. In June 2011, a 57-year-old female patient was referred to our department for pain in the left posterior mandibular region. She reported the following anamnestic data: in 2002, for the diagnosis of breast cancer, she underwent to left quadrantectomy and radiant treatment; from October 2010, she was receiving multimodal chemotherapy containing bevacizumab. No previous treatment with bisphosphonates, or other known local and systemic risk factors were reported. Intraoral examination showed a painful area of bone exposure in the left posterior lingual mandible. The surrounding soft tissue was erythematous with purulent discharge and with swelling of the extraoral soft tissue of the left mandible. After interaction with her oncologist, bevacizumab has been suspended and systemic antibiotic (ampicillina/sulbactam intramuscularly twice daily for 8 days and metronidazole 250mg per os twice daily for 8 days), local antiseptics (chlorhexidine 0.2% mouth rinses and 0.5% chlorhexidine gel) were administered. Results. After 15 days, she showed a complete healing after spontaneous sequestration of a necrotic bone fragment. Conclusions. The antiangiogenic and antiresorptive effects of bevacizumab are dose-dependent and time-dependent. Probably this implies that angiogenesis, bone remodelling and healing processes should restart after drug cessation. The present case supports the necessity to apply BRONJ prevention protocol also in patients in therapy with bevacizumab

Cantor Spectrum for Schr\"odinger Operators with Potentials arising from Generalized Skew-shifts

We consider continuous $SL(2,\mathbb{R})$-cocycles over a strictly ergodic homeomorphism which fibers over an almost periodic dynamical system (generalized skew-shifts). We prove that any cocycle which is not uniformly hyperbolic can be approximated by one which is conjugate to an $SO(2,\mathbb{R})$-cocycle. Using this, we show that if a cocycle's homotopy class does not display a certain obstruction to uniform hyperbolicity, then it can be $C^0$-perturbed to become uniformly hyperbolic. For cocycles arising from Schr\"odinger operators, the obstruction vanishes and we conclude that uniform hyperbolicity is dense, which implies that for a generic continuous potential, the spectrum of the corresponding Schr\"odinger operator is a Cantor set.Comment: Final version. To appear in Duke Mathematical Journa

Lagrangian Statistics and Temporal Intermittency in a Shell Model of Turbulence

We study the statistics of single particle Lagrangian velocity in a shell model of turbulence. We show that the small scale velocity fluctuations are intermittent, with scaling exponents connected to the Eulerian structure function scaling exponents. The observed reduced scaling range is interpreted as a manifestation of the intermediate dissipative range, as it disappears in a Gaussian model of turbulence.Comment: 4 pages, 5 figure

Eriophyid mites in classical biological control of weeds: Progress and challenges

A classical biological control agent is an exotic host-specific natural enemy, which is intentionally introduced to obtain long-term control of an alien invasive species. Among the arthropods considered for this role, eriophyid mites are likely to possess the main attributes required: Host specificity, efficacy, and long-lasting effects. However, so far, only a few species have been approved for release. Due to their microscopic size and the general lack of knowledge regarding their biology and behavior, working with eriophyids is particularly challenging. Furthermore, mites disperse in wind, and little is known about biotic and abiotic constraints to their population growth. All these aspects pose challenges that, if not properly dealt with, can make it particularly difficult to evaluate eriophyids as prospective biological control agents and jeopardize the general success of control programs. We identified some of the critical aspects of working with eriophyids in classical biological control of weeds and focused on how they have been or may be addressed. In particular, we analyzed the importance of accurate mite identification, the difficulties faced in the evaluation of their host specificity, risk assessment of nontarget species, their impact on the weed, and the final steps of mite release and post-release monitoring

3D structure design of magnetic ferrite cores using gelcasting and pressure-less sintering process

Gelcasting is a well established process for ceramics manufacturing which recently has been proved to be successful for soft ferrites as well. This approach is particularly interesting for power electronics application in which the magnetic components (e.g. transformers and inductors) are three dimensionally integrated on the power module substrate. This paper proposes a gelcasting process adapted to make it more effective for 3D heterogeneous integration. The main novelties in this direction consist of low solid load (65wt%) and gelation without catalyst to improve casting and de-airing steps. The magnetic properties of gelcast samples are compared with commercial materials and correlated with the microstructure

On the criticality of inferred models

Advanced inference techniques allow one to reconstruct the pattern of interaction from high dimensional data sets. We focus here on the statistical properties of inferred models and argue that inference procedures are likely to yield models which are close to a phase transition. On one side, we show that the reparameterization invariant metrics in the space of probability distributions of these models (the Fisher Information) is directly related to the model's susceptibility. As a result, distinguishable models tend to accumulate close to critical points, where the susceptibility diverges in infinite systems. On the other, this region is the one where the estimate of inferred parameters is most stable. In order to illustrate these points, we discuss inference of interacting point processes with application to financial data and show that sensible choices of observation time-scales naturally yield models which are close to criticality.Comment: 6 pages, 2 figures, version to appear in JSTA