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The local effect of the Josephson vortices on the vortex lattice melting process in Bi2Sr2CaCu2O8+δ crystals in the presence of an in-plane field Hab is studied by differential magneto-optical imaging. The melting process is found to commence along the Josephson vortex stacks, forming a mesomorphic phase of periodic liquid and solid lamellas, the direction and spacing of which are controlled by Hab. The reduction of the local melting field Hm along the Josephson vortex stacks is more than an order of magnitude larger than the reduction of the average bulk Hm by Hab. [ABSTRACT FROM AUTHOR]

Differential magneto-optics are used to study the effect of a dc in-plane magnetic field on hysteretic behavior due to geometrical barriers in Bi2Sr2CaCu2O8+δ crystals. In the absence of an in-plane field a vortex dome is visualized in the sample center surrounded by barrier-dominated flux-free regions. With an in-plane field, stacks of Josephson vortices form vortex chains, which are surprisingly found to protrude out of the dome and into the vortex-free regions. The chains are imaged to extend up to the sample edges, thus providing easy channels for vortex entry and for drain of the dome through geometrical barrier, suppressing the magnetic hysteresis. Reduction of the vortex energy due to crossing with Josephson vortices is evaluated to be about two orders of magnitude too small to account for the formation of the protruding chains. We present a model and numerical calculations that qualitatively describe the observed phenomena by taking into account the demagnetization effects in which flux expulsion from the pristine regions results in vortex focusing and in the chain protrusion. Comparative measurements on a sample with narrow etched grooves provide further support to the proposed model. [ABSTRACT FROM AUTHOR]

In this paper we study special Moufang sets ( U, τ), with U abelian, under the additional restriction that they have finite Morley rank. Our result states that the little projective group of such a Moufang set must be isomorphic to PSL2( K) for an algebraically closed field K provided that U has characteristic 2 and that infinitely many endomorphisms of U centralize the Hua subgroup. This complements a result of De Medts and Tent that addresses the odd characteristic case. [ABSTRACT FROM AUTHOR]

The article provides a characterization of the Harada-Norton (HN) sporadic simple group as a bicharacteristic {2,5}. It is noted that many of the sporadic simple groups appear to have at least two characteristics, while there are several sporadic groups which should be regarded as groups of bicharacteristic {p,q} with {p,q} ≠ {2,3}. According to the article, a finite Group G K is local if every simple section of every local subgroup of G is a known finite simple group.

In this note we will give an elementary proof of the existence of sharply transitive R-modules M over principal ideal domains R. An R-module is sharply transitive (or a UT-module) if its R-automorphism group acts sharply transitively on the pure elements of M. We will assume that M is torsion-free; thus pure elements are simply those elements divisible only by units of R in M. We provide examples of UT-modules of rank ⩽ , while the existence of UT-modules of rank ⩾ was shown recently in Göbel and Shelah [R. Göbel and S. Shelah. Uniquely transitive torsion-free abelian groups. In Rings, modules, algebras, and abelian groups, Lecture Notes in Pure and Applied Math. 236 (Marcel Dekker, 2004), pp. 271–290.] using the more complicated machinery of prediction principles. The existence of countable abelian UT-groups, which follows from this note, was left open in earlier works. Here we require and exploit the existence of algebraically independent elements over the base ring R. (Thus we will need | R| < .) First we will convert the UT problem on modules (as suggested in Herden [D. Herden. Uniquely transitive R-modules. Ph.D. thesis. University of Duisburg-Essen, Campus Essen (2005).]) into a problem on suitable R-algebras. This reduces its solution to a few simple steps and makes the proofs more transparent, requiring only basic results in module theory. [ABSTRACT FROM AUTHOR]

The article discusses the extension of the characterization of the Harada-Norton sporadic simple group to bicharacteristic {2,p} for any prime p greater than 3. Based on the results, for such primes, a p-local configuration of the type found in the Harada-Norton group for p=5 can appear in a finite group only when p is equal to 3 or 5.

Although recombinant tissue plasminogen activator (rt-PA) was rapidly implemented as part of the emergency care of acute stroke, its use in daily clinical practice still remains controversial in many countries. The most important question is criteria for careful selection of subgroup of patients for this treatment. It has been hypothesized that early computed tomography (CT) changes of ischemia are risk factors for symptomatic intracerebral hemorrhage and poor outcome. We conducted a prospective outcome study of patients with acute ischemic stroke (IS) admitted to the hospital within 6 h of symptom onset. Experienced neuroradiologists blind to the clinical outcome of the patients read all CT scans carried out in the emergency room. Early CT changes were defined as in European Cooperative Acute Stroke Study (ECASS) 2. There were 150 patients (75 males, mean age 72.5 ± 9.0) with acute IS (54.7% with mild stroke and 45.3% with severe stroke). Early CT changes were presented with tissue hypodensity – 55.7%, effacement of sulci – 41.3%, hyperdensity of middle cerebral artery (MCA) – 13.3%, hypodensity of lentiform – 20.7%, loss of insular ribbon sign – 28.7%. Follow-up after 30 days showed that 44% of the patients were discharged home, 20% were discharged to rehabilitation facilities, 22% were discharged to chronic care institutions and 14% died. Data were statistically analyzed. Our data suggest that early signs on CT scan could not predict outcome of patients with acute IS. [ABSTRACT FROM AUTHOR]

An abstract of the article "The additive value of transvaginal ultrasound in the assessment of the clinical staging of early cervical cancer" by Y. Goldberg and colleagues is presented.

Background: Chondroitin sulfate proteoglycan (CSPG) is a major component of the glial scar. It is considered to be a major obstacle for central nervous system (CNS) recovery after injury, especially in light of its well-known activity in limiting axonal growth. Therefore, its degradation has become a key therapeutic goal in the field of CNS regeneration. Yet, the abundant de novo synthesis of CSPG in response to CNS injury is puzzling. This apparent dichotomy led us to hypothesize that CSPG plays a beneficial role in the repair process, which might have been previously overlooked because of nonoptimal regulation of its levels. This hypothesis is tested in the present study.Methods and Findings: We inflicted spinal cord injury in adult mice and examined the effects of CSPG on the recovery process. We used xyloside to inhibit CSPG formation at different time points after the injury and analyzed the phenotype acquired by the microglia/macrophages in the lesion site. To distinguish between the resident microglia and infiltrating monocytes, we used chimeric mice whose bone marrow-derived myeloid cells expressed GFP. We found that CSPG plays a key role during the acute recovery stage after spinal cord injury in mice. Inhibition of CSPG synthesis immediately after injury impaired functional motor recovery and increased tissue loss. Using the chimeric mice we found that the immediate inhibition of CSPG production caused a dramatic effect on the spatial organization of the infiltrating myeloid cells around the lesion site, decreased insulin-like growth factor 1 (IGF-1) production by microglia/macrophages, and increased tumor necrosis factor alpha (TNF-alpha) levels. In contrast, delayed inhibition, allowing CSPG synthesis during the first 2 d following injury, with subsequent inhibition, improved recovery. Using in vitro studies, we showed that CSPG directly activated microglia/macrophages via the CD44 receptor and modulated neurotrophic factor secretion by these cells.Conclusions: Our results show that CSPG plays a pivotal role in the repair of injured spinal cord and in the recovery of motor function during the acute phase after the injury; CSPG spatially and temporally controls activity of infiltrating blood-borne monocytes and resident microglia. The distinction made in this study between the beneficial role of CSPG during the acute stage and its deleterious effect at later stages emphasizes the need to retain the endogenous potential of this molecule in repair by controlling its levels at different stages of post-injury repair. [ABSTRACT FROM AUTHOR]

Abstract: This work focuses on differential magneto-optical two-dimensional imaging of the current distribution in a high-Tc superconducting Bi2Sr2CaCu2O8 crystal having a region of 170×170μm2 patterned with periodic blind antidots. By measuring the self-induced field of an applied current, we can map the current flow distribution within and at the edges of the patterned region. We detected three separate types of current flow within the patterned region, which correspond to three different arrangements of pancake vortices within and at the edges of the patterned region. At high temperatures the vortices delocalize from the antidots, presumably due to thermal fluctuations. However, at lower temperatures vortex pinning mechanisms become prominent, lowering the vortex mobility in the patterned region. There are two contributing mechanisms: bulk pinning by the patterned antidots and interface pinning due to an entry barrier into the patterned region. Each mechanism is dominant at different temperatures. From our experiments we see that the T–H transition line from the bulk to the interface pinning and the vortex melting line in the pristine region coincide. [ABSTRACT FROM AUTHOR]