Tau and muon pair production cross-sections in electron-positron annihilations at sqrt{s} = 10.58 GeV

The calculational precision of \ee\to\tautau and \ee\to\mumu production cross-sections in electron-positron annihilations at \roots = 10.58 \gev are studied for the \kk Monte Carlo simulation program. We determine \sigma(\ee\to\tautau) = (0.919 \pm 0.003) \nb and \sigma(\ee\to\mumu) = (1.147 \pm 0.005) \nb, where the error represents the precision of the calculation.Comment: 7 pages, 3 tables, 1 figure (published in Physical Review D 77, 054012 (2008)

Does simulation-based training facilitate the integration of human anatomy with surgery? A report of a novel Surgical Anatomy Course

Background: Knowledge of gross anatomy, as a basic core subject, is fundamental for medical students and essential to medical practitioners, particularly for those intending a surgical career. However, both medical students and clinical teachers have found a significant gap in teaching basic sciences and the transition into clinical skills. The authors present a Surgical Anatomy Course developed to teach the anatomical basis of surgical procedures with particular emphasis on laparo­scopic skills while incorporating medical simulation. Materials and methods: An evaluation of the students’ satisfaction of the Surgical Anatomy Course was completed using a mix of multiple choice and open-ended questions, and a six-point Likert Scale. Questions were asked about the students’ perceived improvement in surgical and laparoscopic skills. Manual skills were assessed using a laparoscopic simulator. Results: Both evaluation of the course structure and the general impression of the course were positive. Most students believed the course should be an integral part of a modern curriculum. The course supported the traditional surgical classes and improved anatomical knowledge and strengthened students’ confidentiality and facilitated understanding and taking surgical rotations. Conclusions: A medical course combining the practical learning of anatomy and surgical-based approaches will bring out the best from the students. Medical students positively evaluated the Surgical Anatomy Course as useful and benefi­cial regarding understanding anatomical structure and relationship necessary for further surgical education. (Folia Morphol 2018; 77, 2: 279–285

National Aeronautics and Space Administration Biological Specimen Repository

The National Aeronautics and Space Administration Biological Specimen Repository (Repository) is a storage bank that is used to maintain biological specimens over extended periods of time and under well-controlled conditions. Samples from the International Space Station (ISS), including blood and urine, will be collected, processed and archived during the preflight, inflight and postflight phases of ISS missions. This investigation has been developed to archive biosamples for use as a resource for future space flight related research. The International Space Station (ISS) provides a platform to investigate the effects of microgravity on human physiology prior to lunar and exploration class missions. The storage of crewmember samples from many different ISS flights in a single repository will be a valuable resource with which researchers can study space flight related changes and investigate physiological markers. The development of the National Aeronautics and Space Administration Biological Specimen Repository will allow for the collection, processing, storage, maintenance, and ethical distribution of biosamples to meet goals of scientific and programmatic relevance to the space program. Archiving of the biosamples will provide future research opportunities including investigating patterns of physiological changes, analysis of components unknown at this time or analyses performed by new methodologies

Magnetic Properties of Monomer and Dimer Tetrahedral VOx Entities Dispersed on Amorphous Silica-based Materials: Prediction of EPR Parameters from Relativistic DFT Calculations and Broken Symmetry Approach to Exchange Couplings

Molecular structures of the isolated tetrahedral oxovanadium(IV) and bridged μ-oxo-divanadium(IV) complexes hosted by the clusters mimicking surfaces of amorphous silica-based materials were investigated using density functional theory (DFT) calculations. Principal values of the g and A tensors for the monomer vanadyl species were obtained using the coupled-perturbed DFT level of theory and the spin–orbit mean-field approximation (SOMF). Magnetic exchange interaction for the μ-oxo bridged vanadium(IV) dimer was investigated within the broken symmetry approach. An antiferromagnetic coupling of the individual magnetic moments of the vanadium(IV) centers in the [VO–O–VO]2+ bridges was revealed and discussed in detail. The coupling explains pronounced decrease of the electron paramagnetic resonance signal (EPR) intensity, observed for the reduced VOx/SiO2 samples with the increasing coverage of vanadia, in terms of transformation of the paramagnetic monomer species into the dimers with S = 0 ground state

Virtual effects of light gauginos and higgsinos: a precision electroweak analysis of split supersymmetry

We compute corrections to precision electroweak observables in supersymmetry in the limit that scalar superpartners are very massive and decoupled. This leaves charginos and neutralinos and a Standard Model-like Higgs boson as the only states with unknown mass substantially affecting the analysis. We give complete formulas for the chargino and neutralino contributions, derive simple analytic results for the pure gaugino and higgsino cases, and study the general case. We find that in all circumstances, the precision electroweak fit improves when the charginos and neutralinos are near the current direct limits. Larger higgsino and gaugino masses worsen the fit as the theory predictions asymptotically approach those of the Standard Model. Since the Standard Model is considered by most to be an adequate fit to the precision electroweak data, an important corollary to our analysis is that all regions of parameter space allowed by direct collider constraints are also allowed by precision electroweak constraints in split supersymmetry.Comment: 22 pages, 5 figures, v2: typos fixed and note adde

Bound water structure on the surfaces of Usnea antarctica as observed by NMR and sorption isotherm

Hydration courses and proton free induction decays are recorded at 30 MHz for Usnea antarctica thalli hydrated from gaseous phase. NMR data combined with gravimetry allow one to distinguish two fractions of tightly bound water, and loosely bound/free water pool. No water fraction "sealed" in thallus structures is present in U. antarctica

Evidence for Bosonic Electroweak Corrections in the Standard Model

We present strong indirect evidence for the contribution of bosonic electroweak corrections in the Standard Model. Although important conceptually, these corrections give subleading contributions in current high energy experiments, and it was previously thought that they are difficult to detect. We also discuss the separate contribution of the Higgs boson.Comment: 9 pages (LaTeX + 3 PS figures, needs psfig

Accessory spleen mimicking pancreatic tumour: evaluation by 99mTc-labelled colloid SPECT/CT study. Report of two cases and a review of nuclear medicine methods utility

The accessory spleen is a common congenital anomaly, typically asymptomatic and harmless to the patient. However, in some clinical cases, this anomaly beco­mes significant as it can be mistaken for a tumour or lymph node and be missed during a therapeutic splenectomy. There are nuclear medicine modalities which can be applied in the identification and localisation of an accessory spleen. They include scintigraphy with radiolabelled colloids or heat damaged red blood cells, which are trapped in the splenic tissue. Modern techniques, including hybrid imaging, enable simultaneous structure and tracer distribution evaluations. Additionally, radiation-guided surgery can be used in cases where the accessory spleen, which is usually small (not exceeding 1 cm) and difficult to find among other tissues, has to be removed. In the study, we would like to present 2 cases of patients in which the malignancy had to be excluded for the reason that the multiple accessory spleens were very closely related to the pancreas. There was a lack of certainty in the multi-phase computed tomography (CT) evaluation; however, this situation was clearly resolved by using the 99mTc-stannous colloid single photon emission computed tomography/ CT study. We would also like to briefly analyse the clinical applications of nuclear medicine in case of an accessory spleen

Renal-Stone Risk Assessment During Space Shuttle Flights

The metabolic and environmental factors influencing renal stone formation before, during, and after Space Shuttle flights were assessed. We established the contributing roles of dietary factors in relationship to the urinary risk factors associated with renal stone formation. 24-hr urine samples were collected prior to, during space flight, and following landing. Urinary factors associated with renal stone formation were analyzed and the relative urinary supersaturation ratios of calcium oxalate, calcium phosphate (brushite), sodium urate, struvite and uric acid were calculated. Food and fluid consumption was recorded for a 48-hr period ending with the urine collection. Urinary composition changed during flight to favor the crystallization of stone-forming salts. Factors that contributed to increased potential for stone formation during space flight were significant reductions in urinary pH and increases in urinary calcium. Urinary output and citrate, a potent inhibitor of calcium-containing stones, were slightly reduced during space flight. Dietary intakes were significantly reduced for a number of variables, including fluid, energy, protein, potassium, phosphorus and magnesium. This is the first in-flight characterization of the renal stone forming potential in astronauts. With the examination of urinary components and nutritional factors, it was possible to determine the factors that contributed to increased risk or protected from risk. In spite of the protective components, the negative contributions to renal stone risk predominated and resulted in a urinary environment that favored the supersaturation of stone-forming salts. The importance of the hypercalciuria was noted since renal excretion was high relative to the intake