A natural solution to the μ\mu-problem in dynamical supergravity model

The Higgs mixing term coefficient $\mu$ is calculated in the supersymmetric theory which possesses a non-anomalous $U(1)_{R}$ symmetry in the limit of global supersymmetry. In this model, supersymmetry is assumed to be broken by gaugino condensation in the hidden sector when the supergravity effects are turned on. The soft breaking terms in the visible sector and the $\mu$ term of order the weak scale are produced in a simple manner.Comment: 6 pages, Latex, accepted for publication in Phys.Rev.

fatigue limit assessment by energetic analyses in static and cyclic tensile tests

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design of a new intervertebral disc prosthesis a numerical approach

Abstract In the degenerative disc disease, an alternative treatment to the traditional arthrodesis, consisting in the fusion of the two adjacent vertebral bodies, is the artificial intervertebral disc. The advantage of an artificial intervertebral disc is that the d.o.f. of the vertebral segment can be saved and the mobility of the spine could be almost restored. Many solutions were proposed in the last decades, most of them consisting in metallic rigid joints able to assure the mobility and to maintain the correct distance between the vertebrae but subject to corrosion, wear and interface problems due to the different stiffness with the biological tissues. Purpose of this paper is the design of a prosthetic device substituting the disc to be placed in the intervertebral zone. Different types of artificial prostheses have been proposed by the authors, based on similarity with physiological discs, then with a central part (nucleus) made of hyperelastic material and an outer containment frame (annulus) consisting of a plastic material with a stiffness high enough to assure the reaction force and to avoid large radial displacements. In our solutions, the external parts (annulus and plates) were modeled by HDPE and the inner part (nucleus) by silicone and hydrogel. All the materials are highly biocompatible. The intention of the authors, moreover, is to permit an easier surgical technique. The prosthesis, in fact, could be mounted void of the nucleus, allowing an easier placement, and filled only after the frame insertion, by injecting the silicone through a syringe. The nucleus was modeled by the Mooney-Rivlin parameters related to elastomers, being the disc subject to large deformations that the materials have to be able to withstand in elastic conditions. The discs are subjected to compressive loads either in the mounting phase or, after the silicone filling, due to the physiological loads

Brane world models need low string scale

Models with large extra dimensions offer the possibility of the Planck scale being of order the electroweak scale, thus alleviating the gauge hierarchy problem. We show that these models suffer from a breakdown of unitarity at around three quarters of the low effective Planck scale. An obvious candidate to fix the unitarity problem is string theory. We therefore argue that it is necessary for the string scale to appear below the effective Planck scale and that the first signature of such models would be string resonances. We further translate experimental bounds on the string scale into bounds on the effective Planck scale

comparison between thermal energy and acoustic emission for the fatigue behavior of steels

Abstract The paper is focused on the study of fatigue materials, using an energy approach, with the support of two different non-destructive techniques. Indeed, the analysis of the energy behavior was conducted by the simultaneous application of Acoustic Emission (AE) and Thermography (TH). The purpose of the paper was to compare and integrate the results obtained by the two methodologies to assess the fatigue behavior of materials. The experimental tests were carried out on flat steel specimens of steels commonly used for metal carpentry either under static loading or under sequences of increasing cyclic loading. The results allow to define the fatigue limit either by the thermography or by the acoustic emission and they are encouraging to continue the comparison and the integration between the two energetic methodologies

p53-sensitive epileptic behavior and inflammation in Ft1 hypomorphic mice

Epilepsy is a complex clinical condition characterized by repeated spontaneous seizures. Seizures have been linked to multiple drivers including DNA damage accumulation. Investigation of epilepsy physiopathology in humans imposes ethical and practical limitations, for this reason model systems are mostly preferred. Among animal models, mouse mutants are particularly valuable since they allow conjoint behavioral, organismal, and genetic analyses. Along with this, since aging has been associated with higher frequency of seizures, prematurely aging mice, simulating human progeroid diseases, offer a further useful modeling element as they recapitulate aging over a short time-window. Here we report on a mouse mutant with progeroid traits that displays repeated spontaneous seizures. Mutant mice were produced by reducing the expression of the gene Ft1 (AKTIP in humans). In vitro, AKTIP/Ft1 depletion causes telomere aberrations, DNA damage, and cell senescence. AKTIP/Ft1 interacts with lamins, which control nuclear architecture and DNA function. Premature aging defects of Ft1 mutant mice include skeletal alterations and lipodystrophy. The epileptic behavior of Ft1 mutant animals was age and sex linked. Seizures were observed in 18 mutant mice (23.6% of aged ≥ 21 weeks), at an average frequency of 2.33 events/mouse. Time distribution of seizures indicated non-random enrichment of seizures over the follow-up period, with 75% of seizures happening in consecutive weeks. The analysis of epileptic brains did not reveal overt brain morphological alterations or severe neurodegeneration, however, Ft1 reduction induced expression of the inflammatory markers IL-6 and TGF-β. Importantly, Ft1 mutant mice with concomitant genetic reduction of the guardian of the genome, p53, showed no seizures or inflammatory marker activation, implicating the DNA damage response into these phenotypes. This work adds insights into the connection among DNA damage, brain function, and aging. In addition, it further underscores the importance of model organisms for studying specific phenotypes, along with permitting the analysis of genetic interactions at the organismal level

Antecedents of Intention and Behavior Towards Fair Trade Products: A Study on Values and Attitudes in Italy

The current study investigates the significance and power of direct and indirect effects of values and attitudes on intention to buy fair trade products and on self-reported behaviors. Drawing on previous research, we selected three attitudinal measures – Consciousness for Fair Consumption, Environmental Concern, Moral Reasoning – and two categories of human values, Power and Universalism. Through a web-based survey conducted in Italy we collected data analyzed using Structural Equation Modeling. Results showed that Universalism exerted a positive indirect effect on buying fair traded products while Power exerted a negative effect. Therefore, according to Theory of Planned Behavior (Ajzen, 1991), the intention was the only direct antecedent of behavior

Identification of the microorganisms responsible for periodontopathy by Multiplex RT-PCR

The aim of our research was to identify by bacterial genomicDNA analysis the prevalence of five different species of periodontopathogenic bacteria present in the subgingival biofilm,specifically: Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Bacterioides forsytus (Bf), Treponema denticola (Td).For the analysis we used the systematic Multiplex-PCR-microdentkit with species-specific primers. We studied a group of 48 subjects, 18 males and 30 females, from 18 to 78 years of age. Theinitial clinical screening enabled us to select, among the groupanalysed, 24 subjects with signs of active periodontopathy (GroupA) and 24 patients without identifiable clinical evidence of the disease used as the control group (Group B). Within the two experimental groups (A and B), the test was found to be positive in 75%of subjects from group A, whereas the test was found to be negative in all the subjects from group B. Our research shows thatthe Multiplex-PCR system is reliable. Furthermore, the sensitivity and simplicity of this technique, as well as the decrease inworking times and the possibility of identifying non-culturablebacteria, since the presence of viable organisms is not essential,make this technique indicated for the simultaneous identificationof periodontopathogenic bacteria and might, in perspective, pro-vide a more effective clinical alternative to the techniques of bacterial typing of the subgingival plaque

Accuracy Assessment of Virtual Surgical Planning Comparing 3D Virtual Surgical Planning and Post-Operative CBCTs in Surgical Skeletal Class III Cases: A Retrospective Study

Objective: To evaluate the accuracy of Virtual Surgical Planning (VSP) comparing VSPs and post-operative CBCT scans in patients undergoing bimaxillary orthognathic surgery of severe Skeletal Class III malocclusion. Material and Methods: Twenty-three patients (9 males and 14 females, mean age 24.1 ± 7.0 years) were selected and submitted to bimaxillary orthognathic surgery. Pre-operative VSPs and post-operative CBCTs were compared using both linear (taking into account four skeletal and six dental landmarks, each one described by the respective coordinates) and angular measures (seven planes in total). The threshold discrepancies for post-operative clinical acceptable results were set at ≤2 mm for liner and ≤4° for angular discrepancies. The mean difference values and its 95% confidence interval were identified, comparing which planned and which obtained in absolute value. Results: There were significant statistical differences for all absolute linear measures investigated, although only two overcome the linear threshold value of 2mm in both X and Y-linear dimensions. Linear deviations in Z-linear dimension do not reach statistical significance. All 12 angular measures reach the statistical significance, although none overcome the threshold angular value of 4°. Angular deviation for roll register the higher accuracy in contrast to pitch and yaw. Conclusion: Virtual surgical planning is a reliable planning method to be used in orthognathic surgery field; as a matter of fact, although some discrepancies between the planned on the obtained are evident, most of them meet the tolerability range