Case report of a bifurcated fibular (lateral) collateral ligament: which band is the dominant one?

Background: The fibular collateral ligament is a permanent and extracapsular ligament of the knee joint. It is located on the lateral aspect of the knee and extends from the lateral epicondyle of the femur to the lateral surface of the head of the fibula. As one of the main knee joint ligaments it is a stabilizer of the posterolateral corner of the knee and resists varus stress. The case report displays the bifurcated variant of the fibular collateral ligament. The aim of this study is to determine which of those bands should be considered dominant.Materials and methods: Classical anatomical dissection was performed on the left knee joint. The fibular collateral ligament was thoroughly cleansed around its origin, distal attachments, and course. Appropriate morphometric measurements were collected.Results: A bifurcated variant of the fibular collateral ligament with inverted proportions of its two bands (main and accessory one) constitutes our findings. It originated on the lateral epicondyle of the femur. Then it divided into two bands (A1 and A2). Band A1 inserted to the head of the fibula. A bony attachment of band A2 was located on the lateral aspect of the lateral condyle of the tibia.Conclusions: Although the fibular collateral ligament is a permanent structure it presents morphological variations. It is important to constantly extend morphological knowledge for all scientists concerned in anatomy

Screening for thoracoabdominal aortic aneurysms in patients with aortoiliac atherosclerosis: a preliminary study

Thoracoabdominal aortic aneurysms (TAAs) usually present with rupture and carry a high morbidity and mortality rate. Early detection of TAAs with screening methods and elective surgical repair could potentially diminish these complications. The present study was aimed at screening for TAA in patients with angiography-proven aortoiliac atherosclerosis (n = 43). A group of patients without aortoiliac atherosclerosis was used as controls (n = 15). Age, sex and aortic diameter at the level of the T12 vertebra were recorded. The subjects were divided into two age categories, the first made up of those aged less than 65 years and the second those aged 65 years or more. A T12 aortic diameter greater than 35 mm was used to indicate TAA. Statistical analyses were performed by independent t-test and general linear model with age category, sex and atherosclerosis as factors. The mean T12 aortic diameters were greater in patients with atherosclerosis than in the control group (25.2 ± 5.0 vs. 22.9 ± 2.4 mm; p = 0.034). Two out of 43 patients (4.7%) with aortoiliac atherosclerosis had TAA, while no one in the control group had TAA. A general linear model showed that the interaction of age category and sex significantly affected the T12 aortic diameter [F (1.49) = 4.044, p = 0.050]. Post hoc (LSD) tests revealed that male patients aged over 65 had greater T12 aortic diameters than other patients. We conclude that patients with aortoiliac atherosclerosis may be at greater risk for developing TAA. Ageing and male sex may also be associated with thoracoabdominal aortic enlargement. (Folia Morphol 2008; 67: 78-83

Five-headed superior omohyoid

The omohyoid is an infrahyoid muscle with two bellies. It is responsible for lowering and positioning of the hyoid bone. It is morphologically variable in the origin, insertion and morphology of its bellies. Quantitative variations of the superior belly of the omohyoid muscle are not common. We present a case of a five-headed superior omohyoid, and a short clinical review related to this muscle. All the bellies had their origin in an intermediate tendon and were attached to the hyoid bone. The volume of its superior part was greater than usual. Knowledge of the anatomy of this muscle is important, especially for surgeons operating in the anterolateral neck region

“Popliteofascial muscle” or rare variant of the tensor fasciae suralis?

Anatomical variations are routinely encountered during dissections of muscles and in clinical practice, so anatomists and clinicians need to be aware of them. One such muscle is the tensor fascia suralis, a very rare muscle located in the popliteal fossa. It can originate from any of the hamstring muscles and it inserts into the fascia of the leg. This report presents a case of a variant muscle located very deep to the biceps femoris; it originated from the posterior surface of the femur and inserted into the fascia of the leg. It is unclear whether this is a rare variant of the tensor fascia suralis or a completely new muscle

Neutrino Interactions in Hot and Dense Matter

We study the charged and neutral current weak interaction rates relevant for the determination of neutrino opacities in dense matter found in supernovae and neutron stars. We establish an efficient formalism for calculating differential cross sections and mean free paths for interacting, asymmetric nuclear matter at arbitrary degeneracy. The formalism is valid for both charged and neutral current reactions. Strong interaction corrections are incorporated through the in-medium single particle energies at the relevant density and temperature. The effects of strong interactions on the weak interaction rates are investigated using both potential and effective field-theoretical models of matter. We investigate the relative importance of charged and neutral currents for different astrophysical situations, and also examine the influence of strangeness-bearing hyperons. Our findings show that the mean free paths are significantly altered by the effects of strong interactions and the multi-component nature of dense matter. The opacities are then discussed in the context of the evolution of the core of a protoneutron star.Comment: 41 pages, 25 figure

Refractive Index of Humid Air in the Infrared: Model Fits

The theory of summation of electromagnetic line transitions is used to tabulate the Taylor expansion of the refractive index of humid air over the basic independent parameters (temperature, pressure, humidity, wavelength) in five separate infrared regions from the H to the Q band at a fixed percentage of Carbon Dioxide. These are least-squares fits to raw, highly resolved spectra for a set of temperatures from 10 to 25 C, a set of pressures from 500 to 1023 hPa, and a set of relative humidities from 5 to 60%. These choices reflect the prospective application to characterize ambient air at mountain altitudes of astronomical telescopes.Comment: Corrected exponents of c0ref, c1ref and c1p in Table

Relativistic theory of inverse beta-decay of polarized neutron in strong magnetic field

The relativistic theory of the inverse beta-decay of polarized neutron, $\nu _{e} + n \to p + e ^{-}$, in strong magnetic field is developed. For the proton wave function we use the exact solution of the Dirac equation in the magnetic filed that enables us to account exactly for effects of the proton momentum quantization in the magnetic field and also for the proton recoil motion. The effect of nucleons anomalous magnetic moments in strong magnetic fields is also discussed. We examine the cross section for different energies and directions of propagation of the initial neutrino accounting for neutrons polarization. It is shown that in the super-strong magnetic field the totally polarized neutron matter is transparent for neutrinos propagating antiparallel to the direction of polarization. The developed relativistic approach can be used for calculations of cross sections of the other URCA processes in strong magnetic fields.Comment: 41 pages in LaTex including 11 figures in PostScript, discussion on nucleons AMM interaction with magnetic field is adde

Nucleon Spin Fluctuations and the Supernova Emission of Neutrinos and Axions

In the hot and dense medium of a supernova (SN) core, the nucleon spins fluctuate so fast that the axial-vector neutrino opacity and the axion emissivity are expected to be significantly modified. Axions with m_a\alt10^{-2}\,{\rm eV} are not excluded by SN~1987A. A substantial transfer of energy in neutrino-nucleon ($\nu N$) collisions is enabled which may alter the spectra of SN neutrinos relative to calculations where energy-conserving $\nu N$ collisions had been assumed near the neutrinosphere.Comment: 8 pages. REVTeX. 2 postscript figures, can be included with epsf. Small modifications of the text, a new "Note Added", and three new references. To be published in Phys. Rev. Let

Crucial Physical Dependencies of the Core-Collapse Supernova Mechanism

We explore with self-consistent 2D F{\sc{ornax}} simulations the dependence of the outcome of collapse on many-body corrections to neutrino-nucleon cross sections, the nucleon-nucleon bremsstrahlung rate, electron capture on heavy nuclei, pre-collapse seed perturbations, and inelastic neutrino-electron and neutrino-nucleon scattering. Importantly, proximity to criticality amplifies the role of even small changes in the neutrino-matter couplings, and such changes can together add to produce outsized effects. When close to the critical condition the cumulative result of a few small effects (including seeds) that individually have only modest consequence can convert an anemic into a robust explosion, or even a dud into a blast. Such sensitivity is not seen in one dimension and may explain the apparent heterogeneity in the outcomes of detailed simulations performed internationally. A natural conclusion is that the different groups collectively are closer to a realistic understanding of the mechanism of core-collapse supernovae than might have seemed apparent.Comment: 25 pages; 10 figure