On the formfactor of the imaginary part and its coupling to the real optical potential for the α\alpha-nucleus scattering

The model-independent formfactor of the absorptive cc-nucleus potential was calculated and compared with model dependent ones. The coupling between the shapes of the real and imaginary potential is discussed

Static response of Fermi liquids with tensor interactions

We use Landau's theory of a normal Fermi liquid to derive expressions for the static response of a system with a general tensor interaction that conserves the total spin and the total angular momentum of the quasiparticle-quasihole pair. The magnetic susceptibility is calculated in detail, with the inclusion of the center of mass tensor and cross vector terms in addition to the exchange tensor one. We also introduce a new parametrization of the tensor Landau parameters which significantly reduces the importance of high angular harmonic contributions. For nuclear matter and neutron matter we find that the two most important effects of the tensor interaction are to give a contribution from multipair states and to renormalize the magnetic moments. Response to a weak probe may be calculated using similar methods, replacing the magnetic moments with the matrix elements of the weak charges

The sonographic morphology of musculus palmaris longus in humans

Background: The aim of this work was to describe morphology and morphometry of musculus palmaris longus and compare the outcome of Shaeffer’s test with ultrasound imaging.Materials and methods: Forty forearms of 20 healthy volunteers (11 females, 9 males) were tested by Shaeffer’s test and ultrasound imaging. Anthropological measurements of the forearm and ultrasound guided measurements of musculus palmaris longus were taken. The outcome was tested for statistical significanceby Fisher’s test.Results: The examination revealed agenesis of palmaris longus in 6 cases, as well as 6 muscles showing quality variations. The Shaeffer’s test gave 4 false-negative results. 28 muscles were described as spindle-shaped and 8 as pennated or bipennated. However, all the spindle-shaped muscles demonstrated a tendon going inside of the muscle’s belly ranging from 2 cm to 11.5 cm. The relation between the circumference of the forearm right below the elbow (mean: 15.38 cm, SD: 1.83 cm) and the approximated volume of the palmaris longus muscle’s belly(mean: 4.72 cm3, SD: 1.57 cm3) proved to be statistically significant (Fisher’s test p-value < 0.05).Conclusions: Uncommon morphological variations have been shown. Spindle-shaped muscles have proved to have their tendons continued inside them. Palmaris longus muscle’s belly has proved to take significant amount of volume within the proximal forearm. Shaeffer’s test has shown to have 10% false-negative ratio

Ossa Sesamoidea — prevalence of sesamoid bones in human hands

Background: This study describes the morphology of sesamoid bones in the human hand. Ultrasound imaging was used to record the presence and measurements of sesamoids in 120 hands of 60 healthy, young adults of Caucasian ethnicity. Materials and methods: The mean number of sesamoid bones was 4.16 in the left hand and 4.03 in the right hand. 21.6% of cases showed asymmetry between the right hand and the left. There was a significant difference in the prevalence of sesamoid bones between right and left hand in males in this study. Females show a higher incidence of sesamoid bones overall, but do not demonstrate a significant difference between the sides. Results: Prevalence findings: Two in the 1st metacarpophalangeal joint (MCPJ) in 99.2% of cases, with 1 case of a single bone. One in the 2nd MCPJ in 43.3% of cases. One in the 5th MCPJ in 84.2% of cases. One in the 1st interphalangeal joint (IPJ) in 83.4% of cases. Aside from that there was 1 case of sesamoid in the 3rd MCPJ and separate case of sesamoid in the 3rd proximal IPJ. Conclusions: Moreover, this study discusses discrepancies of opinion regarding sesamoid bones in morphological research

Quantum phantom cosmology

We apply the formalism of quantum cosmology to models containing a phantom field. Three models are discussed explicitly: a toy model, a model with an exponential phantom potential, and a model with phantom field accompanied by a negative cosmological constant. In all these cases we calculate the classical trajectories in configuration space and give solutions to the Wheeler-DeWitt equation in quantum cosmology. In the cases of the toy model and the model with exponential potential we are able to solve the Wheeler-DeWitt equation exactly. For comparison, we also give the corresponding solutions for an ordinary scalar field. We discuss in particular the behaviour of wave packets in minisuperspace. For the phantom field these packets disperse in the region that corresponds to the Big Rip singularity. This thus constitutes a genuine quantum region at large scales, described by a regular solution of the Wheeler-DeWitt equation. For the ordinary scalar field, the Big-Bang singularity is avoided. Some remarks on the arrow of time in phantom models as well as on the relation of phantom models to loop quantum cosmology are given.Comment: 21 pages, 6 figure

Morphology of sesamoid bones in keyboard musicians

Background: The sesamoid bones are small, usually oval bone structures often found in joints and under the tendons. Although their precise function is not fully understood, it is agreed upon that they protect the joints and make movements faster and less energy consuming. Sesamoid bones are found in hands, especially around first, second and fifth metacarpophalangeal joint and the interphalangeal joint of the thumb. Materials and methods: This study compares a group of 32 young musicians to 30 non-musicians of similar age and posture. The hands of the subjects were examined by ultrasound imaging for the presence of sesamoid bones. The results were noted and observed sesamoids were measured. Results: The results seem to prove that although there are no difference in the amount or the location of the sesamoid bones between the musicians and the non-musicians, there is statistically significant tendency for the musicians to have bigger sum of the sesamoid’s volume per hand (Fisher’s test p-value = 0.034 < 0.05). Conclusions: There was also observed an unusually shaped “Bactrian” sesamoid bone at the interphalangeal joint of the thumb in 8 cases in the musicians’ group and 1 case in the control group. All participants with the aforementioned structure were female

Ab-initio calculations of the optical properties of the Si(113)3x2ADI surface

We investigated the stable silicon (113) surface with a 3x2ADI reconstruction by ab-initio methods. The ground state properties have been obtained using the density-functional theory. We present the dispersion of the electronic band structure, where the surface bands have been distinguished from the projected bulk bands by calculating their localization in the slab. The optical spectra, here the reflectance anisotropy (RAS), have been obtained within the independent particle random phase approximation. We identified surface features in the spectra tracing them back to the responsible electronic states and, studied their localization in the slab. A comparison with available experimental data for the band structure and the RAS shows a good agreement.Comment: 10 pages, 10 figure

One-variable word equations in linear time

In this paper we consider word equations with one variable (and arbitrary many appearances of it). A recent technique of recompression, which is applicable to general word equations, is shown to be suitable also in this case. While in general case it is non-deterministic, it determinises in case of one variable and the obtained running time is O(n + #_X log n), where #_X is the number of appearances of the variable in the equation. This matches the previously-best algorithm due to D\k{a}browski and Plandowski. Then, using a couple of heuristics as well as more detailed time analysis the running time is lowered to O(n) in RAM model. Unfortunately no new properties of solutions are shown.Comment: submitted to a journal, general overhaul over the previous versio

Brane universes tested by supernovae

We discuss observational constrains coming from supernovae Ia \cite{Perlmutter99} imposed on the behaviour of the Randall-Sundrum models. In the case of dust matter on the brane, the difference between the best-fit general relativistic model with a $\Lambda$-term \cite{Perlmutter99} and the best-fit brane models becomes detectable for redshifts $z > 0.6$. It is interesting that brane models predict brighter galaxies for such redshifts which is in agreement with the measurement of the $z = 1.7$ supernova \cite{Riess01} and with the New Data from the High Z Supernovae Search Team \cite{schmit02}. We also demonstrate that the fit to supernovae data can also be obtained, if we admit the "super-negative" dark energy $p = - (4/3) \varrho$ on the brane, where the dark energy in a way mimics the influence of the cosmological constant. It also appears that the dark energy enlarges the age of the universe which is demanded in cosmology. Finally, we propose to check for dark radiation and brane tension by the application of the angular diameter of galaxies minimum value test.Comment: 4 pages, 5 figures, REVTEX4, amended versio