901 research outputs found

    The career of Maclyn McCarty

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    On January 2, 2005, the scientific community lost a valued colleague and friend. Maclyn McCarty, or “Mac,” as he was better known, was perhaps most recognized for his part in the discovery of DNA as the carrier of genetic information. But McCarty's scientific career was long and fruitful, and his contributions to science were vast. This retrospective offers a look at some of Mac's other notable scientific achievements

    Climbing depth-bounded adjacent discrepancy search for solving hybrid flow shop scheduling problems with multiprocessor tasks

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    This paper considers multiprocessor task scheduling in a multistage hybrid flow-shop environment. The problem even in its simplest form is NP-hard in the strong sense. The great deal of interest for this problem, besides its theoretical complexity, is animated by needs of various manufacturing and computing systems. We propose a new approach based on limited discrepancy search to solve the problem. Our method is tested with reference to a proposed lower bound as well as the best-known solutions in literature. Computational results show that the developed approach is efficient in particular for large-size problems

    The graceful exit from the anomaly-induced inflation: Supersymmetry as a key

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    The stable version of the anomaly-induced inflation does not need a fine tuning and leads to sufficient expansion of the Universe. The non-stable version (Starobinsky model) provides the graceful exit to the FRW phase. We indicate the possibility of the inflation which is stable at the beginning and unstable at the end. The effect is due to the soft supersymmetry breaking and the decoupling of the massive sparticles at low energy.Comment: 10 pages, 2 figures using axodraw. Modified version. Discussion concerning the gravitational scale modified, the effect of massive particles in the last stage of inflation taken into accoun

    In-room test results at CNAO of an innovative PT treatments online monitor (Dose Profiler)

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    The use of C, He and O ions as projectiles in Particle Therapy (PT) treatments is getting more and more widespread as a consequence of their enhanced relative biological effectiveness and oxygen enhancement ratio, when compared to the protons one. The advantages related to the incoming radiation improved efficacy are requiring an accurate online monitor of the dose release spatial distribution. Such monitor is necessary to prevent unwanted damage to the tissues surrounding the tumour that can arise, for example, due to morphological changes occurred in the patient during the treatment with respect to the initial CT scan. PT treatments with ions can be monitored by detecting the secondary radiation produced by the primary beam interactions with the patient body along the path towards the target volume. Charged fragments produced in the nuclear process of projectile fragmentation can be emitted at large angles with respect to the incoming beam direction and can be detected with high efficiency in a nearly background-free environment. The Dose Profiler (DP) detector, developed within the INSIDE project, is a scintillating fibre tracker that allows an online reconstruction and backtracking of such secondary charged fragments. The construction and preliminary in-room tests performed on the DP, carried out using the 12C ions beam of the CNAO treatment centre using an anthropomorphic phantom as a target, will be reviewed in this contribution. The impact of the secondary fragments interactions with the patient body will be discussed in view of a clinical application. Furthermore, the results implications for a pre-clinical trial on CNAO patients, foreseen in 2019, will be discussed

    Plantar pain is not always fasciitis

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    The case is described of a patient with chronic plantar pain, diagnosed as fasciitis, which was not improved by conventional treatment. Magnetic resonance imaging revealed flexor hallucis longus tenosynovitis, which improved after local glucocorticoid injection

    An exact self-consistent gravitational shock wave in semiclassical gravity

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    We find a self-consistent pp-gravitational shock wave solution to the semiclassical Einstein equations resulting from the 1/N1/N approach to the effective action. We model the renormalized matter stress-energy-momentum tensor by NN massless scalar fields in the Minkowski vacuum plus a classical particle. We show that quantum effects generate a milder singularity at the position of the particle than the classical solution, but the singularity does not disappear. At large distances from the particle, the quantum correction decreases slowly, as 1/ρ21/\rho^2 (ρ\rho being the distance to the particle in the shock wave plane). We argue that this large distance correction is a necessary consequence of quantum gravity.Comment: 13 pages, REVTEX, 4 PS figures. Revised version contains a derivation of the solution compatible with its distributional character. The final results, though, are the sam

    Which physical activity in patients affected by hypoparathyroidism? A review of the literature and practical recommendations

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    Background Hypoparathyroidism (HypoP) is a rare endocrine condition characterized by hypocalcaemia and hyperphos- phatemia, as a consequence of absent or improperly low parathyroid hormone (PTH) levels. Patients affected by HypoP have a clinical condition often characterized by paresthesias and muscle spasms, as well as long-term consequences as nephro- lithiasis, extraskeletal calcification, and fractures. In the literature, likely due to these symptoms, few data exist regarding the appropriate physical activity (PA) in subjects suffering from HypoP. Purpose This review evaluates the literature on exercise-based approaches to the management of individuals affected by HypoP and evaluates: (1) the effects of physical exercise on muscle cramps and other clinical symptoms; (2) the effects of exercise on PTH and calcium level; (3) the most suitable clinical exercise testing; and (4) the most suitable exercise combination. Methods and results A systematic search was conducted using the databases MEDLINE, Google Scholar using “hypopar- athyroidism AND Physical Activity”, “Training AND hypoparathyroidism”, “Exercise AND muscle cramps”, “Exercise AND Fatigue” as keywords. In addition, references list from the included articles were searched and cross-checked to identify any further potentially eligible studies. A total of 50 manuscripts were found among which 39 manuscripts were selected. A few clinical studies have been performed in HypoP patients to evaluate PA training protocols. Conclusion Although further research is needed to draw solid conclusions regarding best PA protocols in subjects affected by HypoP, a PA protocol has been proposed within the manuscript to encourage patients to attempt exercise to improve their clinical conditions and their quality of life

    Scintillating fiber devices for particle therapy applications

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    Particle Therapy (PT) is a radiation therapy technique in which solid tumors are treated with charged ions and exploits the achievable highly localized dose delivery, allowing to spare healthy tissues and organs at risk. The development of a range monitoring technique to be used on-line, during the treatment, capable to reach millimetric precision is considered one of the important steps towards an optimization of the PT efficacy and of the treatment quality. To this aim, charged secondary particles produced in the nuclear interactions between the beam particles and the patient tissues can be exploited. Besides charged secondaries, also neutrons are produced in nuclear interactions. The secondary neutron component might cause an undesired and not negligible dose deposition far away from the tumor region, enhancing the risk of secondary malignant neoplasms that can develop even years after the treatment. An accurate neutron characterization (flux, energy and emission profile) is hence needed for a better evaluation of long-term complications. In this contribution two tracker detectors, both based on scintillating fibers, are presented. The first one, named Dose Profiler (DP), is planned to be used as a beam range monitor in PT treatments with heavy ion beams, exploiting the charged secondary fragments production. The DP is currently under development within the INSIDE (Innovative Solutions for In-beam DosimEtry in hadrontherapy) project. The second one is dedicated to the measurement of the fast and ultrafast neutron component produced in PT treatments, in the framework of the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project. Results of the first calibration tests performed at the Trento Protontherapy center and at CNAO (Italy) are reported, as well as simulation studies

    Molecular basis for recognition of the Group A Carbohydrate backbone by the PlyC streptococcal bacteriophage endolysin

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    Endolysins are peptidoglycan (PG) hydrolases that function as part of the bacteriophage (phage) lytic system to release progeny phage at the end of a replication cycle. Notably, endolysins alone can produce lysis without phage infection, which offers an attractive alternative to traditional antibiotics. Endolysins from phage that infect Gram-positive bacterial hosts contain at least one enzymatically active domain (EAD) responsible for hydrolysis of PG bonds and a cell wall binding domain (CBD) that binds a cell wall epitope, such as a surface carbohydrate, providing some degree of specificity for the endolysin. Whilst the EADs typically cluster into conserved mechanistic classes with well-defined active sites, relatively little is known about the nature of the CBDs and only a few binding epitopes for CBDs have been elucidated. The major cell wall components of many streptococci are the polysaccharides that contain the polyrhamnose (pRha) backbone modified with species-specific and serotype-specific glycosyl side chains. In this report, using molecular genetics, microscopy, flow cytometry and lytic activity assays, we demonstrate the interaction of PlyCB, the CBD subunit of the streptococcal PlyC endolysin, with the pRha backbone of the cell wall polysaccharides, Group A Carbohydrate (GAC) and serotype c-specific carbohydrate (SCC) expressed by the Group A Streptococcus and Streptococcus mutans, respectively
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