OCT findings in macular hole formation in eyes with complete vitreofoveal separation

The current study describes the morphologic macular features in two eyes that developed full-thickness macular holes in the setting of documented vitreofoveal separation. Using third-generation optical coherence tomography, complete vitreofoveal separation associated with the disruption of the inner foveal retina was documented in both cases. Five months after presentation, decreased vision and epiretinal membrane formation associated with development of a full-thickness macular hole were observed in the first patient. In the second patient, a full-thickness macular hole was demonstrated by optical coherence tomography 6 weeks after presentation. These findings suggest that full-thickness macular holes may develop in eyes with vitreofoveal separation. Evidence of the disturbance of the inner foveal architecture on optical coherence tomography indicates the potential role of factors other than anteroposterior or oblique vitreoretinal tractional forces in the genesis of some full-thickness macular holes.

Effect of Multiple Cranial Burr Hole Surgery on Prevention of Recurrent Ischemic Attacks in Children with Moyamoya Disease

Moyamoya disease (MMD) is an uncommon cerebrovascular disorder characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches. Direct and indirect bypass techniques have been devised with the aim of promoting neoangiogenesis. The current study aimed to investigate the role of multiple cranial burr hole (MCBH) operations in the prevention of cerebral ischemic attacks in children with MMD. Seven children suffering from progressive MMD were submitted to the MCBH and arachnoid opening technique. Ten to 20 burr holes were drilled in the fronto-temporo-parieto-occipital area of each hemisphere in each patient, depending on the site and extent of the disease. All patients were evaluated pre- and postoperatively by means of Barthel index (BI), CT, MR, angio-MR, and angiography. Patients had no recurrence of ischemic attacks postoperatively. Neoangiogenesis was observed in both hemispheres. One patient developed a persistent subdural collection after surgery, thus requiring placement of a subdural-peritoneal shunt. Postoperative BI was statistically significantly improved (P = 0.02). This report suggests that MCBH for revascularization in MMD is a simple procedure with a relatively low risk of complications and effective for preventing cerebral ischemic attacks in children. In addition, MCBH may be placed as an adjunct to other treatments for MMD.

Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of 3-Hole 4.5 mm locking compression plate and 3-hole 4.5 mm narrow dynamic compression plate, with two transarticular 5.5 mm cortex screws

Objectives To compare the biomechanical characteristics of 2 arthrodesis techniques for the equine proximal interphalangeal joint (PIP) using either a 3-hole 4.5 mm locking compression plate (LCP) or 3-hole 4.5 mm narrow dynamic compression plate (DCP), both with 2 transarticular 5.5 mm cortex screws. Study Design Experimental. Sample Population Cadaveric adult equine forelimbs (*n=6 pairs). Methods For each forelimb pair, 1 limb was randomly assigned to 1 of 2 treatment groups and the contralateral limb by default to the other treatment group. Construct stiffness, gap formation across the PIP joint, and rotation about the PIP joint were determined for each construct before cyclic axial loading and after each of four, 5000 cycle loading regimens. After the 20,000 cycle axial loading regimen, each construct was loaded to failure. Results There were no significant differences in construct stiffness, gap formation, or sagittal plane rotation between the LCP and DCP treatment groups at any of the measured time points. Conclusion Biomechanically, fixation of the equine PIP joint with a 3-hole 4.5 mm LCP is equivalent to fixation with a 3-hole 4.5 mm narrow DCP under the test conditions used.

Haplotypes of the bovine IgG2 heavy gamma chain in tick-resistant and tick-susceptible breeds of cattle

Bovines present contrasting, heritable phenotypes of infestations with the cattle tick, Rhipicephalus (Boophilus) microplus. Tick salivary glands produce IgG-binding proteins (IGBPs) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. Allotypes that occur in the constant region of IgG may differ in their capacity to bind with tick IGBPs; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. In order to test this hypothesis, we investigated the frequency of haplotypes of bovine IgG2 among tick-resistant and tick-susceptible breeds of bovines. Sequencing of the gene coding for the heavy chain of IgG2 from 114 tick-resistant (Bos taurus indicus, Nelore breed) and tick-susceptible (B. t. taurus, Holstein breed) bovines revealed SNPs that generated 13 different haplotypes, of which 11 were novel and 5 were exclusive of Holstein and 3 of Nelore breeds. Alignment and modeling of coded haplotypes for hinge regions of the bovine IgG2 showed that they differ in the distribution of polar and hydrophobic amino acids and in shape according to the distribution of these amino acids. We also found that there was an association between genotypes of the constant region of the IgG2 heavy chain with phenotypes of tick infestations. These findings open the possibility of investigating if certain IgG allotypes hinder the function of tick IGBPs. If so, they may be markers for breeding for resistance against tick infestations.

Lines of heavy elements and Fe II in the UV of CS 31082-001

The abundance of heavy r-elements may provide a better understanding of the r-process, and the determination of several reference r-elements should allow a better determination of a star`s age. The space UV region (lambda < 3000 angstrom) presents a large number of lines of the heavy elements, and in the case of some elements, such as Bi, Pt, Au, detectable lines are not available elsewhere. The extreme ""r-process star"" CS 31082-001 ([Fe/H] = -2.9) was observed in the space UV to determine abundances of the heaviest stable elements, using STIS on board Hubble Space Telescope.

Neurofilament heavy subunit in cerebrospinal fluid: A biomarker of amyotrophic lateral sclerosis?

The objectives of this study were to investigate the presence of the three neurofilament subunits, ubiquitin, proteasome and 3-nitrotyrosine, in CSF samples of ALS patients. CSF samples were obtained by lumbar puncture from 10 ALS patients and six controls. All samples were analysed by Western blotting. Results revealed that neurofilament heavy subunit was identified in 70% of ALS cases and we conclude that this subunit may be a promising biomarker for clinical diagnosis of ALS.

SU(3) mass-splittings of heavy-baryons in QCD

We extract directly (for the first time) the charmed (C = 1) and bottom (B = -1) heavy-baryons (spin 1/2 and 3/2) mass-splittings due to SU(3) breaking using double ratios of QCD spectral sum rules (QSSR) in full QCD, which are less sensitive to the exact value and definition of the heavy quark mass, to the perturbative radiative corrections and to the QCD continuum contributions than the simple ratios commonly used for determining the heavy baryon masses. Noticing that most of the mass-splittings are mainly controlled by the ratio kappa <(S) over bars >/<(d) over bard > of the condensate, we extract this ratio, by allowing 1 sigma deviation from the observed masses of the Xi(c.b) and of the Omega(c). We obtain: kappa = 0.74(3), which improves the existing estimates: kappa = 0.70(10) from light hadrons. Using this value, we deduce M(Omega b) = 6078.5(27.4) MeV which agrees with the recent CDF data but disagrees by 2.4 sigma with the one from D0. Predictions of the Xi(Q)` and of the spectra of spin 3/2 baryons containing one or two strange quark are given in Table 2. Predictions of the hyperfine splittings Omega(Q)* - Omega(Q) and Xi(Q)* - Xi(Q) are also given in Table 3. Starting for a general choice of the interpolating currents for the spin 1/2 baryons, our analysis favours the optimal value of the mixing angle b similar or equal to (-1/5-0) found from light and non-strange heavy baryons. (C) 2010 Elsevier B.V. All rights reserved.

Fragment mass distributions in the fission of heavy nuclei by intermediate- and high-energy probes

Recent experiments have shown that the multimode approach for describing the fission process is compatible with the observed results. Asystematic analysis of the parameters obtained by fitting the fission-fragment mass distribution to the spontaneous and low-energy data has shown that the values for those parameters present a smooth dependence upon the nuclear mass number. In this work, a new methodology is introduced for studying fragment mass distributions through the multimode approach. It is shown that for fission induced by energetic probes (E > 30 MeV) the mass distribution of the fissioning nuclei produced during the intranuclear cascade and evaporation processes must be considered in order to have a realistic description of the fission process. The method is applied to study (208)Pb, (238)U, (239)Np and (241)Am fission induced by protons or photons.

Influence of heavy rare earth ions substitution on microstructure and magnetism of nanocrystalline magnetite

In this work we report results on the influence of heavy rare earth ions substitution on microstructure and magnetism of nanocrystalline magnetite. A series of Fe(2.85)RE(0.15)O(4) (RE = Gd, Dy, Ho, Tm and Yb) samples have been prepared by high energy ball milling. Structure/microstructure investigations of two selected samples Fe(2.85)Gd(0.15)O(4) and Fe(2.85)Tm(0.15)O(4), represent an extension of the previously published results on Fe(3)O(4)/gamma-Fe(2)O(3), Fe(2.85)Y(0.15)O(4) and Fe(2.55)In(0.45)O(4) [Z. Cvejic, S. Rakic, A. Kremenovic, B. Antic, C. Jovalekic. Ph. Colomban, Sol. State Sciences 8 (2006) 908], while magnetic characterization has been done for all the samples. Crystallite/particle size and strain determined by X-ray diffractometry and Transmission electron microscopy (TEM) confirmed the nanostructured nature of the mechanosynthesized materials. X-ray powder diffraction was used to analyze anisotropic line broadening effects through the Rietveld method. The size anisotropy was found to be small while strain anisotropy was large, indicating nonuniform distribution of deffects in the presence of Gd and Tm in the crystal structure. Superparamagnetic(SPM) behavior at room temperature was observed for all samples studied. The Y-substituted Fe(3)O(4) had the largest He and the lowest M(S). We discuss the changes in magnetic properties in relation to their magnetic anisotropy and microstructure. High field irreversibility (H>20kOe) in ZFC/FC magnetization versus temperature indicates the existence of high magnetocrystalline and/or strain induced anisotropy. (C) 2008 Elsevier B.V. All rights reserved.

Effect on the heavy-ion fusion and elastic scattering cross sections of common approximations assumed in coupled-channel calculations

We study the effects of several approximations commonly used in coupled-channel analyses of fusion and elastic scattering cross sections. Our calculations are performed considering couplings to inelastic states in the context of the frozen approximation, which is equivalent to the coupled-channel formalism when dealing with small excitation energies. Our findings indicate that, in some cases, the effect of the approximations on the theoretical cross sections can be larger than the precision of the experimental data.

An imaginary potential with universal normalization for dissipative processes in heavy-ion reactions

In this work we present new coupled channel calculations with the Sao Paulo potential (SPP) as the bare interaction, and an imaginary potential with system and energy independent normalization that has been developed to take into account dissipative processes in heavy-ion reactions. This imaginary potential is based on high-energy nucleon interaction in nuclear medium. Our theoretical predictions for energies up to approximate to 100 MeV/nucleon agree very well with the experimental data for the p, n + nucleus, (16)O + (27)Al, (16)O + (60)Ni, (58)Ni + (124)Sn, and weakly bound projectile (7)Li + (120)Sn systems. (C) 2008 Elsevier B.V. All rights reserved.

Mass-splittings of doubly heavy baryons in QCD

We consider (for the first time) the ratios of doubly heavy baryon masses (spin 3/2 over spin 1/2 and SU(3) mass-splittings) using double ratios of sum rules (DRSR), which are more accurate than the usual simple ratios often used in the literature for getting the hadron masses. In general, our results agree and compete in precision with potential model predictions. In our approach, the alpha(s) corrections induced by the anomalous dimensions of the correlators are the main sources of the Xi(QQ)*-Xi(QQ) mass-splittings, which seem to indicate a 1/M(Q) behaviour and can only allow the electromagnetic decay Xi(QQ)* -> Xi(QQ) + gamma but not to Xi(QQ) + pi. Our results also show that the SU(3) mass-splittings are (almost) independent of the spin of the baryons and behave approximately like 1/M(Q), which could be understood from the QCD expressions of the corresponding two-point correlator. Our results can improved by including radiative corrections to the SU(3) breaking terms and can be tested, in the near future, at Tevatron and LHCb. (C) 2010 Published by Elsevier B.V.

Heavy-flavor measurements by the PHENIX experiment at RHIC

In recent years, PHENIX has studied many important observables related to heavy-flavor physics through their leptonic decay measurements including the invariant yield of electrons from nonphotonic sources, and prompt single muons, both of which are dominated by D and B mesons. Charm and beauty cross-sections were measured and compared through single lepton, and lepton-hadron correlations in p+p collisions at root s = 200 GeV. Observables for quarkonia production such as invariant yield and polarization were also measured in p+p collisions. In Au+Au collisions, preliminary results for the R(AA) for single electrons and a 90% CL upper limit for the suppression of s were produced. And in d+Au collisions, a preliminary R(CP) study for J/psi production in different centrality ranges was extracted.

Universal trend for heavy-ion total reaction cross-sections at energies above the Coulomb barrier

Heavy-ion total reaction cross-section measurements for more than 1100 reaction cases covering 61 target nuclei in the range (6)Li-(238)U and 158 projectile nuclei from (2)H to (84)Kr (mostly exotic ones) have been analyzed in a systematic way by using an empirical, three-parameter formula that is applicable to the cases of projectile kinetic energies above the Coulomb barrier. The analysis has shown that the average total nuclear binding energy per nucleon of the interacting nuclei and their radii are the chief quantities that describe the cross-section patterns. A great amount of cross-section data (87%) has been quite satisfactorily reproduced by the proposed formula; therefore, the total reaction cross-section predictions for new, not yet experimentally investigated reaction cases can be obtained within 25% (or much less) uncertainty.

VACUUM POLARIZATION EFFECTS ON QUASINORMAL MODES IN ELECTRICALLY CHARGED BLACK HOLE SPACE-TIMES

We investigate the influence of vacuum polarization of quantum massive fields on the scalar sector of quasinormal modes in spherically symmetric black holes. We consider the evolution of a massless scalar field on the space-time corresponding to a charged semiclassical black hole, consisting of the quantum-corrected geometry of a Reissner-Nordstrom black hole dressed by a quantum massive scalar field in the large mass limit. Using a sixth order WKB approach we find a shift in the quasinormal mode frequencies due to vacuum polarization.