Low-frequency internal friction in clamped-free thin wires

We present a series of internal friction measurements for the normal modes of circular fibres made of different materials, that can suspend the test masses of an interferometric gravity wave detector. For metallic wires, the frequency independent loss angle ranges between 10 y3 and 10 y4 . The losses in fused silica are two orders of magnitude lower than those in metals

Mobility of pyroclastic flows

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Effects of flow volume and grain size on mobility of dry granular flows of angular rock fragments: A functional relationship of scaling parameters

Flows of angular rock fragments are released down a concave upward chute in the laboratory to study their mobility. This mobility is measured as the reciprocal of the apparent coefficient of friction that is equal to the vertical drop of the centre of mass of the granular material divided by its horizontal distance of travel. Our experiments show that the finer the grain size (all the other features the same), the larger is the mobility of the centre of mass. We believe this to be due to the fact that in finer grain size flows there are less agitated particles per unit of flow mass so that these flows dissipate less energy per unit of travel distance. Our experiments show also that the larger the volume (all the other features the same), the larger is the apparent coefficient of friction. We believe this to be so because the frontal portion of a flow reaches the less steep part of a curved slope and stops before the rear portion preventing the rear portion and the centre of mass from travelling further downhill. This phenomenon (which is more prominent in larger volume flows whose rear and frontal ends are more distant) counteracts the decrease of energy dissipation per unit of flow mass, due to the decrease of particle agitation per unit of flow mass, that is expected when the volume of a flow increases (all the other features the same). Our analysis generates a functional relationship between the dimensionless apparent coefficient of friction and a scaling parameter whose numerator is equal to the mean grain size multiplied by the cube root of the deposit volume and whose denominator is the square of the channel width

Virulence and antimicrobial resistance in canine staphylococcus spp. Isolates

Dogs are reservoirs of different Staphylococcus species, but at the same time, they could develop several clinical forms caused by these bacteria. The aim of the present investigation was to characterize 50 clinical Staphylococcus isolates cultured from sick dogs. Bacterial species determina-tion, hemolysins, protease, lipase, gelatinase, slime, and biofilm production, presence of virulence genes (lukS/F-PV, eta, etb, tsst, icaA, and icaD), methicillin resistance, and antimicrobial resistance were investigated. Most isolates (52%) were Staphylococcus pseudointermedius, but 20% and 8% be-longed to Staphylococcus xylosus and Staphylococcus chromogenes, respectively. Gelatinase, biofilm, and slime production were very common characters among the investigated strains with 80%, 86%, and 76% positive isolates, respectively. Virulence genes were detected in a very small number of the tested strains. A percentage of 14% of isolates were mecA-positive and phenotypically-resistant to methicillin. Multi-drug resistance was detected in 76% of tested staphylococci; in particular, high levels of resistance were detected for ampicillin, amoxicillin, clindamycin, and erythromycin. In conclusion, although staphylococci are considered to be opportunistic bacteria, the obtained data showed that dogs may be infected by Staphylococcus strains with important virulence characteristics and a high antimicrobial resistance

NUTRITIONAL STATUS IN EVOLUTIVE AGE: ASSESSMENT OF FAT MASS AMOUNT AND DISTRIBUTION AND OF THEIR SIGNIFICANCE IN METABOLIC DERANGEMENTS

Introduction: Chronic-degenerative diseases are nowadays in Italy the leading cause of death and requests for health care. Many of them, as indicated by the World Health Organization (WHO), are attributable to behaviors and lifestyles that are established from an early age, including improper eating habits, lack of physical activity and excess weight gain. Obesity is a condition characterized by an excessive accumulation of body fat, usually due to poor diets and a sedentary lifestyle, even if the etiology of obesity reflects a complex interaction between genetic, metabolic, environmental, cultural, socioeconomic, and behavioral factors. Previous studies have shown an association between adiposity, especially intra-abdominal adipose tissue, and hemodynamic/metabolic comorbidities in adults, however it is not clear in pediatric population. Aims of the study: to see the correlation between anthropometric measures and visceral fat assessed by ultrasonography in a large population of children; to see the clinical correlation of visceral fat accumulation in childhood obesity with respect to the development of metabolic derangements, compared to body mass index and waist circumference; to investigate the effects of visceral fat accumulation in developmental age; in particular we supposed that, like in adults, the increment of abdominal visceral fat, measured by ultrasonography, is associated with a worsened metabolic profile and with the increment of metabolic syndrome risk. Subjects and methods: 83 patients (58 females and 28 males), with age range 11-17 and mean age of 14,6 years. All the patients were subject to anthropometric measurements of weight, height, BMI, waist circumference (WC), skin folds. Patients were also subject to body fat assessment with air-displacement plethysmography, Dual Energy X-ray Absorptiometry (DEXA), Bioelectrical Inpedance Analysis (BIA) and Ultrasound: we considered measurements of abdominal subcutaneous skin-hepatic thickness (pre-hepatic AT), abdominal subcutaneous skin-muscle thickness (umbilical AT), intra-abdominal muscle-aorta thickness (Aortic AT). Each patient undergo to blood test evaluation including total cholesterol, high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), triglycerides (TG), fasting blood glucose, insulin, renal function as creatinine and blood urea nitrate, hepatic function as glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT) and gamma glutamyl transpeptidase (GGT); metabolic syndrome was considered according to the International Diabetes Federation (IDF) criteria. Statistical analysis was conducted using SPSS-20, p value <0.05 was considered significant. Results and discussion: Our cohort of patients showed a significant difference of VAT between the two sexes, even after matching subjects for BMI, supporting that there is a definite gender difference in the age-related changes in whole-body fat distribution, especially in the abdominal fat tissues. The present study revealed a significant correlation between visceral fat and all the other anthropometric measures; regression analysis showed that among the measurements used in this study, the best predictor of visceral fat is waist to height ratio. With the data in our possess so far, we want to futher investigate this problem, in order to establish if assessment of visceral fat in children should be better done by an imaging modality and not indirectly from anthropometric measurements. In the present study, visceral fat assessment was observed to be closely associated with glucose metabolic risk factors including high fasting glucose and insulin resistance. This finding confirms that visceral adipose tissue is associated with glucose metabolism in evolutive age as well as in adult age, as already postulated. No significant correlations were found between visceral fat and hepatic function, except for \u3b3GT, demonstrating visceral fat to be an important predictor for hepatic functioning derangements. The association between visceral adipose tissue and lipid metabolism biomarkers is not so evident in our study. After adjustment for age, sex and BMI, we didn\u2019t find any significant correlation between intra abdominal adipose tissue and lipid status. No significant relationship could be found between VAT and the presence of metabolic syndrome or its diagnostic criteria such as high triglycerides, high fasting glucose, low HDL, high blood pressure; a good correlation, even if not significant, was found with insulin resistance, suggesting once again visceral fat deposit to be involved in glucose derangements and in diabetes mellitus type 2 onset. The only significant correlation was found with VF to be a major risk to have high \u3b3GT, showing an odds ratio of 11,3. The results we have presented among children and adolescent are very similar to those presented for adults so far, showing probably similar pathways in the visceral fat accumulation and in its metabolic significance. Further studies will be held to better investigate the importance of visceral fat accumulation in evolutive age as a predictor for metabolic derangements

Low Level of Colistin Resistance and mcr Genes Presence in Salmonella spp.: Evaluation of Isolates Collected between 2000 and 2020 from Animals and Environment

Salmonellosis is one of the most important zoonoses in Europe and the world. Human infection may evolve in severe clinical diseases, with the need for hospitalization and antimicrobial treatment. Colistin is now considered an important antimicrobial to treat infections from multidrugresistant Gram-negative bacteria, but the spreading of mobile colistin-resistance (mcr) genes has limited this option. We aimed to evaluate colistin minimum inhibitory concentration and the presence of mcr (mcr-1 to mcr-9) genes in 236 Salmonella isolates previously collected from different animals and the environment between 2000 and 2020. Overall, 17.79% of isolates were resistant to colistin; no differences were observed in relation to years of isolation (2000–2005, 2009–2014, and 2015–2020), Salmonella enterica subspecies (enterica, salamae, diarizonae, and houtenae), origin of samples (domestic animals, wildlife, and environment), or animal category (birds, mammals, and reptiles); only recently isolated strains from houseflies showed the most resistance. Few isolates (5.93%) scored positive for mcr genes, in particular for mcr-1, mcr-2, mcr-4, mcr-6, and mcr-8; furthermore, only 2.54% of isolates were mcr-positive and colistin-resistant. Detected resistance to colistin was equally distributed among all examined Salmonella isolates and not always related to the presence of mcr genes

MECHANICAL SHOT NOISE INDUCED BY CREEP IN SUSPENSION DEVICES

Abstract The sensitivity curve of a gravitational wave interferometric detector like VIRGO might be seriously limited by the mechanical shot noise induced by stationary creep in the heavily loaded mechanical suspension components (wires, spring blades, etc.). We quantify this effect and discuss possible improvements which could be implemented without major design alterations

2D photonic-crystal optomechanical nanoresonator

We present the optical optimization of an optomechanical device based on a suspended InP membrane patterned with a 2D near-wavelength grating (NWG) based on a 2D photonic-crystal geometry. We first identify by numerical simulation a set of geometrical parameters providing a reflectivity higher than 99.8 % over a 50-nm span. We then study the limitations induced by the finite value of the optical waist and lateral size of the NWG pattern using different numerical approaches. The NWG grating, pierced in a suspended InP 265 nm-thick membrane, is used to form a compact microcavity involving the suspended nano-membrane as end mirror. The resulting cavity has a waist size smaller than 10 $\mu$m and a finesse in the 200 range. It is used to probe the Brownian motion of the mechanical modes of the nanomembrane

Antimicrobial‐Resistant Enterococcus spp. in Wild Avifauna from Central Italy

Bacteria of the genus Enterococcus are opportunistic pathogens, part of the normal intestinal microflora of animals, able to acquire and transfer antimicrobial resistance genes. The aim of this study was to evaluate the possible role of wild avifauna as a source of antimicrobial‐resistant enterococci. To assess this purpose, 103 Enterococcus spp. strains were isolated from the feces of wild birds of different species; they were tested for antimicrobial resistance against 21 molecules, vancomycin resistance, and high‐level aminoglycosides resistance (HLAR). Furthermore, genes responsible for vancomycin, tetracycline, and HLAR were searched. E. faecium was the most frequently detected species (60.20% of isolates), followed by E. faecalis (34.95% of isolates). Overall, 99.02% of the isolated enterococci were classified as multidrug‐resistant, with 19.41% extensively drug‐resistant, and 2.91% possible pan drug-resistant strains. Most of the isolates were susceptible to amoxicillin/clavulanic acid (77.67%) and ampicillin (75.73%), with only 5.83% of isolates showing an ampicillin MIC ≥ 64 mg/L. HLAR was detected in 35.92% of isolates, mainly associated with the genes ant(6)‐Ia and aac(6′)‐Ie‐aph(2′’)‐Ia. Few strains (4.85%) were resistant to vancomycin, and the genes vanA and vanB were not detected. A percentage of 54.37% of isolates showed resistance to tetracycline; tet(M) was the most frequently detected gene in these strains. Wild birds may contribute to the spreading of antimicrobial‐resistant enterococci, which can affect other animals and humans. Constant monitoring is essential to face up to the evolving antimicrobial resistance issue, and monitoring programs should include wild avifauna, to

A Novel Approach Based on Spatio-temporal Features and Random Forest for Scar Detection Using Cine Cardiac Magnetic Resonance Images

Aim. To identify the presence of scar tissue in the left ventricle from Gadolinium (Gd)-free magnetic resonance cine sequences using a learning-based approach relying on spatio-temporal features. Methods. The spatial and temporal features were extracted using local binary patterns from (i) cine end-diastolic frame and (ii) two parametric images of amplitude and phase wall motion, respectively, and classified with Random Forest. Results. When tested on 328 cine sequences from 40 patients, a recall of 70% was achieved, improving significantly the classification resulting from spatial and temporal features processed separately. Conclusions. The proposed approach showed promising results, paving the way for scar identification from Gd-free images