1,981 research outputs found
Supersymmetry without a light Higgs boson at the LHC
We analyze the LHC phenomenology of lambdaSUSY - a version of NMSSM with a
largish SH1H2 coupling. The scalar spectrum of the model contains a 200-300 GeV
Higgs boson h with Standard-Model like properties, and heavy CP-even and CP-odd
Higgs bosons H and A with masses in 500-800 GeV range. We study the discovery
potential of H and A in the decay chains H->hh->4V->2l6j and A->Zh->Z2V->2l4j.
The dominant backgrounds are the diffuse Z6j and Z4j productions, which can be
suppressed by demanding reconstruction of V's and h's in intermediate states.
The excess of signal events allows for a discovery of both H and A with over
5sigma significance for 100 inverse fb of integrated luminosity.Comment: 29 pages, 19 figure
Aerodynamic brake for formula cars
In the last years, in formula racing cars championships, the aerodynamic had reached an ever
more important stance as a performance parameter. In the last four seasons, Red Bull Racing
Technical Officer had designed their Formula 1 car with the specific aim to generate the optimal
downforce, in relation to the car instantaneous setup. However, this extreme research of higher
downforce brings some negative effects when a car is within the wake of another car; indeed, it is
well known that under these condition the aerodynamic is disturbed, and it makes difficult to
overtake the leading car. To partially remedy this problem, Formula 1 regulations introduced the
Drag Reduction System (DRS) in 2011, which was an adjustable flap located on the rear wing; if it
is flattened, allowing to reduce the downforce, increasing significantly the velocity and, therefore,
the chances to overtake the leading car. Vice versa, when the flap is closed, it ensures a higher grip,
which is very useful especially in medium-slow speed turns. Keeping the focus on the rear wing,
but by shifting attention from the increased top speed to increase the grip in the middle and slow
speed curves, we decided to study a similar device to the DRS, but with the opposite effect. The aim
is to design an aerodynamic brake integrated with the rear wing. In particular, the project idea
was to sculpt, on the upper surface of the wing (pressure side), a series of "C" shaped cavity, normally
covered by adequate sliding panels. These cavities, when they are discovered, at the beginning
of the braking phase, produce a turbulence and additional increase downforce, lightening the
load on the braking system and allowing the pilot to substantially reduce slippage and to delay the
braking. Since it seems that the regulations adopted by the FIA Formula 1 Championship do not
allow such a device, it has been decided to apply the concept on a Formula 4 vehicle. This paper
describes the design and analyzes the effects of these details on a standard wing cavity, using a
commercial CFD software.In the last years, in formula racing cars championships, the aerodynamic had reached an ever
more important stance as a performance parameter. In the last four seasons, Red Bull Racing
Technical Officer had designed their Formula 1 car with the specific aim to generate the optimal
downforce, in relation to the car instantaneous setup. However, this extreme research of higher
downforce brings some negative effects when a car is within the wake of another car; indeed, it is
well known that under these condition the aerodynamic is disturbed, and it makes difficult to
overtake the leading car. To partially remedy this problem, Formula 1 regulations introduced the
Drag Reduction System (DRS) in 2011, which was an adjustable flap located on the rear wing; if it
is flattened, allowing to reduce the downforce, increasing significantly the velocity and, therefore,
the chances to overtake the leading car. Vice versa, when the flap is closed, it ensures a higher grip,
which is very useful especially in medium-slow speed turns. Keeping the focus on the rear wing,
but by shifting attention from the increased top speed to increase the grip in the middle and slow
speed curves, we decided to study a similar device to the DRS, but with the opposite effect. The aim
is to design an aerodynamic brake integrated with the rear wing. In particular, the project idea
was to sculpt, on the upper surface of the wing (pressure side), a series of "C" shaped cavity, normally
covered by adequate sliding panels. These cavities, when they are discovered, at the beginning
of the braking phase, produce a turbulence and additional increase downforce, lightening the
load on the braking system and allowing the pilot to substantially reduce slippage and to delay the
braking. Since it seems that the regulations adopted by the FIA Formula 1 Championship do not
allow such a device, it has been decided to apply the concept on a Formula 4 vehicle. This paper
describes the design and analyzes the effects of these details on a standard wing cavity, using a
commercial CFD software
Homogeneous and inhomogeneous contributions to the luminescence linewidth of point defects in amorphous solids: Quantitative assessment based on time-resolved emission spectroscopy
The article describes an experimental method that allows to estimate the
inhomogeneous and homogeneous linewidths of the photoluminescence band of a
point defect in an amorphous solid. We performed low temperature time-resolved
luminescence measurements on two defects chosen as model systems for our
analysis: extrinsic Oxygen Deficient Centers (ODC(II)) in amorphous silica and
F+ 3 centers in crystalline Lithium Fluoride. Measurements evidence that only
defects embedded in the amorphous matrix feature a dependence of the radiative
decay lifetime on the emission energy and a time dependence of the first moment
of the emission band. A theoretical model is developed to link these properties
to the structural disorder typical of amorphous solids. Specifically, the
observations on ODC(II) are interpreted by introducing a gaussian statistical
distribution of the zero phonon line energy position. Comparison with the
results obtained on F+ 3 crystalline defects strongly confirms the validity of
the model. By analyzing experimental data within this frame, we obtain separate
estimations of the homogenous and inhomogeneous contributions to the measured
total linewidth of ODC(II), which results to be mostly inhomogeneous.Comment: 8 pages, 4 figure
Fluorescence hyper-spectral imaging to detecting faecal contamination on fresh tomatoes
Faecal contamination of fresh fruits represents a severe danger for human health. Thus some techniques based on microbiological testing were developed to individuate faecal contaminants but those tests do not results efficient because their non-applicability on overall vegetable unity. In this work a methodology based on hyper-spectral fluorescence imaging was developed and tested to detecting faecal contamination on fresh tomatoes. Two image-processing methods were performed to maximise the contrast between the faecal contaminant and tomatoes skin: principal component analysis and band image ratio (BRI). The BRI method allows classifying correctly 70% of contaminated area, with no false-positives in all examined cases. Thus, the developed methodology can be employed for a fast and effective detection of faecal contamination on fresh tomatoes
The epigenetic effects of butyrate: potential therapeutic implications for clinical practice
Butyrate is a short chain fatty acid derived from the microbial fermentation of dietary fibers in the colon. In the last decade, multiple beneficial effects of butyrate at intestinal and extraintestinal level have been demonstrated. The mechanisms of action of butyrate are different and many of these involve an epigenetic regulation of gene expression through the inhibition of histone deacetylase. There is a growing interest in butyrate because its impact on epigenetic mechanisms will lead to more specific and efficacious therapeutic strategies for the prevention and treatment of different diseases ranging from genetic/metabolic conditions to neurological degenerative disorders. This review is focused on recent data regarding the epigenetic effects of butyrate with potential clinical implications in human medicine
A Novel Approach to Guided Implant Surgery: A Technical Note
Computer-guided software and kits have significantly improved the clinical applications of implant surgery. Nonetheless, some technical problems are still in evidence during clinical procedures because of cumbersome surgical tools that can limit access to implant sites, mainly in posterior areas of the mouth in the presence of bulky anatomical structures and in patients with reduced mouth-opening capacity. The present paper aimed to present a novel approach to guided implant surgery, describing the technical characteristics of an innovative guided surgical kit made up of modified sleeves and modular surgical drills. The proposed guided surgical kit is based on a novel patented system of sleeves and modular burs, with an increased length of the metal sleeves and a reduced height of the drills. The innovative design of the proposed system would allow the clinician to position guided fixtures in all clinical situations; the reduced encumbrance would be particularly helpful to gain access to the posterior areas of both maxilla and mandible, which have limited inter-arch space, with an easy and user-friendly approach. The modular system could overcome anatomical limitations, such as reduced mouth-opening capacity, and permit clinicians to maintain the stability and integrity of the surgical templates, even in cases where there is very limited intermaxillary space
Increasing rate of hospitalizations for food-induced anaphylaxis in Italian children: an analysis of the Italian Ministry of Health database.
emerged regarding other day-to-day issues. Physicians were
overall misinformed about the availability of epinephrine in
both restaurants and ambulances. When questioned regarding
quality of life, only 10% of family practitioners and 31% of
pediatricians believed that ‘‘severe allergies’’ have a major impact
on quality of life. This differs markedly from results of previous
studies about patients’ perceptions regarding the effects of food
allergy on quality of life.10 More pediatric A/I specialists (78%)
than others (P 5 .03) believed that life-threatening
allergic reactions today are more common than 10 years
ago, consistent with published data,11 and most physicians in
all groups recognized that asthma is a risk factor for severe
reactions.
Similar to our surveys of patients and the general public, this
study clearly demonstrates the need for ongoing education
regarding anaphylaxis. As with previous studies, knowledge
gaps are especially apparent for primary care and emergency
physicians, who are most often the physicians on the front line in
the treatment of this common and life-threatening condition
Metacognition as a predictor of improvements in personality disorders
Personality Disorders (PDs) are particularly hard to treat and treatment drop-out rates are high. Several authors have agreed that psychotherapy is more successful when it focuses on the core of personality pathology. For this reason, therapists dealing with PDs need to understand the psychopathological variables that characterize this pathology and exactly what contributes to maintaining psychopathological processes. Moreover, several authors have noted that one key problem that characterizes all PDs is an impairment in understanding mental states - here termed metacognition - which could also be responsible for therapy failures. Unfortunately, a limited number of studies have investigated the role of mentalization in the process of change during psychotherapy. In this paper, we assume that poor metacognition corresponds to a core element of the general pathology of personality, impacts a series of clinical variables, generates symptoms and interpersonal problems, and causes treatment to be slower and less effective. We explored whether changes in metacognition predicted an improvement among different psychopathological variables characterizing PDs; 193 outpatients were treated at the Third Center of Cognitive Psychotherapy in Rome, Italy, and followed a structured path tailored for the different psychopathological variables that emerged from a comprehensive psychodiagnostic assessment that considered patients' symptoms, metacognitive abilities, interpersonal relationships, personality psychopathology, and global functioning. The measurements were repeated after a year of treatment. The results showed that changes in metacognitive abilities predicted improvements in the analyzed variable
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