Rhombencephalosynapsis: cerebellar embryogenesis

We describe two infants in whom rhombencephalosynapsis was diagnosed with MR imaging in vivo. In contrast to Dandy-Walker malformation, the vermian maldevelopment in this anomaly is characterized by an absence of the anterior vermis and a deficiency of the posterior vermis. The cerebellar hemispheres are fused. In an attempt to identify the pathogenesis of these anatomic manifestations, we question the traditional concept of the embryologic development of the cerebellar primordium.     

Neurocalcin immunoreactivity in the rat main olfactory bulb

The morphological characteristics and distribution of neurocalcin (NC)-immunoreactive elements were studied in the rat main olfactory bulb (OB) using a polyclonal antibody and the avidin-biotin immunoperoxidase method. NC-positive elements were abundant in the glomerular layer (GL), where numerous immunostained external tufted cells and periglomerular cells were detected. Other less abundant NC-immunolabeled populations included middle and internal tufted cells, Van Gehuchten cells, horizontal cells, vertical cells of Cajal, deep short-axon cells and granule cells. This study demonstrates the presence of NC immunoreactivity in subsets of different neuronal types in the rat main OB. This calcium-binding protein has been found in interneurons, and no evidence of immunoreactivity to NC is detected in projecting neurons. Despite the large population of labeled external tufted cells, most of them belong according to morphological criteria to the local circuit group and some others to those with interbulbar and/or intrabulbar connections. The identification of neuronal subpopulations expressing NC provides a further characterization and shows the existence of biochemical differences within morphologically identical neurons. Thus, this marker may be a useful tool in unravelling the circuitries of the rodent OB in both normal and experimental conditions. The exact physiological function of NC in the olfactory system remains unknown. On the basis of similarities to recoverin, it could be involved in mechanisms responsible for sensory adaptation. Additionally, its calcium-binding abilities may contribute to improve the temporal precision of stimuli transmission, or be concerned with general calcium-related events occurring in specific interneuronal groups.     

Properties of extracellular products produced by group A streptococci isolated from patients with streptococcal toxic shock syndrome

Extracellular products of group A streptococci isolated from patients with streptococcal toxic shock syndrome (STSS) were examined. The outline of the discussion of the 3 products are as follows; streptolysin O (SLO), proteinase and erythrogenic toxin. SLO and proteinase showed a relatively large amount of products more than erythrogenic toxin. SLO produced by group A streptococci isolated from the patient with STSS had an isoelectric point (pI) of 6.0 and a molecular weight of 64,000 and showed hemolytic activity in the presence of 2-mercaptoethanol (2-ME). Furthermore, the hemolytic activities of all components were inhibited by gamma-globulin and cholesterol. Proteinase had pIs of 8.7 and 8.9, and a molecular weight of 21,000. These data suggest that STSS clinical criteria probably reflects a characteristic of a large amount of products of individual S. pyogenes isolates.     

Recovery of liquid fuel from hydrocarbon-rich microalgae by thermochemical liquefaction

Liquefaction of Botryococcus braunii, a colony-forming microalga, with high moisture content was performed with or without sodium carbonate as a catalyst for conversion into liquid fuel and recovery of hydrocarbons. A greater amount of oil than the content of hydrocarbons in B. braunii (50 wt% db) was obtained, in a yield of 57–64 wt% at 300 °C. The oil was equivalent in quality to petroleum oil. The recovery of hydrocarbons was a maximum (>95%) at 300 °C.     

Activation of protein-tyrosine kinase Pyk2 is downstream of Syk in FcepsilonRI signaling

Aggregation of the FcepsilonRI, a member of the immune receptor family, induces the activation of proteintyrosine kinases and results in tyrosine phosphorylation of proteins that are involved in downstream signaling pathways. Here we report that Pyk2, another member of the focal adhesion kinase family, was present in the RBL-2H3 mast cell line and was rapidly tyrosine-phosphorylated and activated after FcepsilonRI aggregation. Tyrosine phosphorylation of Pyk2 was also induced by the calcium ionophore A23187, by phorbol myristate acetate, or by stimulation of G-protein-coupled receptors. Adherence of cells to fibronectin dramatically enhanced the induced tyrosine phosphorylation of Pyk2. Although Src family kinases are activated by FcepsilonRI stimulation and tyrosine-phosphorylate the receptor subunits, the activation and tyrosine phosphorylation of Pyk2 were downstream of Syk. In contrast, tyrosine phosphorylation of Pyk2 by stimulation of G-protein-coupled receptors was independent of Syk. Therefore, the FcepsilonRI-induced tyrosine phosphorylation of Pyk2 is downstream of Syk and may play a role in cell secretion.     

Endoscopic mucosal resection of gastric tumors located in the lesser curvature of the upper third of the stomach

Between July 1991 and February 1995, 33 patients underwent bipolar shoulder arthroplasty for painful rotator cuff arthropathy of the shoulder. Twenty-two of these patients have been followed for an average of 28 months (range 24 to 48 months) and comprised the study group. All patients had massive, irreparable rotator cuff tears and presented with preserved passive motion, good deltoid function, and obliterated glenohumeral joint surfaces. Function and comfort were dramatically improved in all patients, with an average increase in active forward elevation of 29 degrees and a gain in active external rotation of 39 degrees. There was one complication requiring reoperation at 4 years. Utilizing the UCLA and Swanson scoring systems, all patients were rated fair or better.     

An explicit application of partition of unity approach to XFEM approximation for precise reproduction of a priori knowledge of solution

The application of the XFEM to fracture mechanics is effective, because a crack can be modeled independently from the meshes and a complex remeshing procedure can be avoided. However, the classical XFEM has an essential problem in the approximation of partially enriched elements, that is, blending elements, which causes a lack of accuracy. For the weighted XFEM, although the numerical results show the effective improvements, it was found that the issue of blending elements still remains upon detailed examination. In the present paper, the PU‐XFEM is formulated as an explicit application of the partition of unity (PU) approach to the XFEM, in order to precisely reproduce a priori knowledge of the solution by enrichment. The PU‐XFEM is applied to two‐dimensional linear fracture mechanics, and its effectiveness is verified. It is consequently found out that the PU‐XFEM precisely reproduces a priori knowledge of the solution and is therefore effective to completely solve the problem of the blending elements. Copyright © 2013 John Wiley & Sons, Ltd.     

Electricity markets volatility: estimates,regularities and risk management applications

The recent deregulation of the market for electric power in many parts of the US and Canada has expanded the set of potential tools for managing the types of risks faced by both generators and consumers of electric power. In particular manufacturing and other firms whose operations are powered by electricity now face, on a continuing basis, the engineering management decisions concerning whether they should buy or produce electricity, and if they are to buy or sell electricity, what types of contracts are optimum. These types of risk management decisions typically involve futures, forwards, options and other financial derivatives. The price and volatility of electric power are known to play an essential role in determining which of these instruments should be used. However, electricity as a commodity possesses certain special features not shared by other commodities and hence its risk properties are not yet well understood. In this paper we consider and test certain hypotheses about the properties of electricity price using recent market data. We find that electricity prices possess certain volatility and other systematic properties that can be characterized by the type and method of delivery of electricity. These properties can be used by firms in formulating their optimal demand and supply schedules of electric power.