Symmetry group analysis of an ideal plastic flow

In this paper, we study the Lie point symmetry group of a system describing an ideal plastic plane flow in two dimensions in order to find analytical solutions. The infinitesimal generators that span the Lie algebra for this system are obtained. We completely classify the subalgebras of up to codimension two in conjugacy classes under the action of the symmetry group. Based on invariant forms, we use Ansatzes to compute symmetry reductions in such a way that the obtained solutions cover simultaneously many invariant and partially invariant solutions. We calculate solutions of the algebraic, trigonometric, inverse trigonometric and elliptic type. Some solutions depending on one or two arbitrary functions of one variable have also been found. In some cases, the shape of a potentially feasible extrusion die corresponding to the solution is deduced. These tools could be used to thin, curve, undulate or shape a ring in an ideal plastic material

Multimode solutions of first-order elliptic quasilinear systems obtained from Riemann invariants

Two new approaches to solving first-order quasilinear elliptic systems of PDEs in many dimensions are proposed. The first method is based on an analysis of multimode solutions expressible in terms of Riemann invariants, based on links between two techniques, that of the symmetry reduction method and of the generalized method of characteristics. A variant of the conditional symmetry method for constructing this type of solution is proposed. A specific feature of that approach is an algebraic-geometric point of view, which allows the introduction of specific first-order side conditions consistent with the original system of PDEs, leading to a generalization of the Riemann invariant method for solving elliptic homogeneous systems of PDEs. A further generalization of the Riemann invariants method to the case of inhomogeneous systems, based on the introduction of specific rotation matrices, enables us to weaken the integrability condition. It allows us to establish a connection between the structure of the set of integral elements and the possibility of constructing specific classes of simple mode solutions. These theoretical considerations are illustrated by the examples of an ideal plastic flow in its elliptic region and a system describing a nonlinear interaction of waves and particles. Several new classes of solutions are obtained in explicit form, including the general integral for the latter system of equations

Neurognathostomiasis, a Neglected Parasitosis of the Central Nervous System

Gnathostomiasis is a foodborne zoonotic helminthic infection caused by the third-stage larvae of Gnathostoma spp. nematodes. The most severe manifestation involves infection of the central nervous system, neurognathostomiasis. Although gnathostomiasis is endemic to Asia and Latin America, almost all neurognathostomiasis cases are reported from Thailand. Despite high rates of illness and death, neurognathostomiasis has received less attention than the more common cutaneous form of gnathostomiasis, possibly because of the apparent geographic confinement of the neurologic infection to 1 country. Recently, however, the disease has been reported in returned travelers in Europe. We reviewed the English-language literature on neurognathostomiasis and analyzed epidemiology and geographic distribution, mode of central nervous system invasion, pathophysiology, clinical features, neuroimaging data, and treatment options. On the basis of epidemiologic data, clinical signs, neuroimaging, and laboratory findings, we propose diagnostic criteria for neurognathostomiasis

On the Stability of the Eye Shell under an Encircling Band

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Targeting cyclin D3/CDK6 activity for treatment of Parkinson’s disease.

30 p.-7 fig.-1 tab.At present, treatment for Parkinson’s disease (PD) is only symptomatic, therefore it is important to identify new targets tackling the molecular causes of the disease. We previously found that lymphoblasts from sporadic PD patients display increased activity of the cyclin D3/CDK6/pRb pathway and higher proliferation than control cells. These features were considered systemic manifestations of the disease, as aberrant activation of cell cycle is involved in neuronal apoptosis. The main goal of this work was to elucidate whether the inhibition of cyclin D3/CDK6-associated kinase activity could be useful in PD treatment. For this purpose, we investigated the effects of two histone deacetylase (HDAC) inhibitors, suberoylanilide hydroxamic acid (SAHA) and sodium butyrate (NaB), and the m-TOR inhibitor rapamycin on cell viability and cyclin D3/CDK6 activity. Moreover, the potential neuroprotective action of these drugs was evaluated in 6-hydroxy-dopamine (6-OHDA) treated dopaminergic SH-SY5Y cells and primary rat mesencephalic cultures. Here we report that both compounds normalized the proliferative activity of PD lymphoblasts and reduced the 6-OHDA-induced cell death in neuronal cells by preventing the overactivation of the cyclin D3/CDK6/pRb cascade.Considering that these drugs are already used in clinic for treatment of other diseases with good tolerance, it is plausible that they may serve as novel therapeutic drugs for PD.This work has been supported by grants from Ministerio de Economía y Competitividad (SAF2011-28603) and Fundación Ramón Areces.Peer reviewe

Complexity-Based Modeling of Scientific Capital: An Outline of Mathematical Theory

The paper intends to contribute to a better understanding of the phenomenon of scientific capital. Scientific capital is a well-known concept for measuring and assessing the accumulated recognition and the specific scientific power. The concept of scientific capital developed by Bourdieu is used in international social science research to explain a set of scholarly properties and practices. Mathematical modeling is applied as a lens through which the scientific capital is addressed. The principal contribution of this paper is an axiomatic characterization of scientific capital in terms of natural axioms. The application of the axiomatic method to scientific capital reveals novel insights into problem still not covered by mathematical modeling. Proposed model embraces the interrelations between separate sociological variables, providing a unified sociological view of science. Suggested microvariational principle is based upon postulate, which affirms that (under suitable conditions) the observed state of the agent in scientific field maximizes scientific capital. Its value can be roughly imagined as a volume of social differences. According to the considered macrovariational principle, the actual state of scientific field makes so-called energy functional (which is associated with the distribution of scientific capital) minimal

Schweres nichtkardiales Lungenödem durch Permeabilitätsstörung nach i.v.-CT-Kontrastmittel-Gabe mit konsekutiver venovenöser extrakorporaler Membranoxygenierung

Hypersensitivity reactions are one of the most feared side effects associated with the use of CT contrast agents. Bronchospasm and lung edema are known manifestations, whereby the latter occurs much less often. In anaphylaxis, numerous mechanisms can lead to cardiac failure with subsequent lung edema. In contrast, the cardiac function is not impaired in noncardiogenic pulmonary edema (NCPE), which is a~rare phenomenon but with potentially fatal outcome. The exact pathophysiology of NCPE remains unknown and characteristically response to conventional anaphylaxis treatment is poor. This article presents the case of a~48-year-old man with NCPE who underwent elective coronary CT as part of the evaluation of recurrent syncope. After administration of iodinated contrast medium the patient developed a fulminant lung edema, which led to severe hypoxemia with cardiac arrest despite immediate treatment by the medical emergency team, including assisted ventilation, prednisolone, dimetindene and adrenaline. An early echocardiographic assessment after ROSC and intubation showed an intact cardiac function and no signs of valvular pathologies. Arterial blood gas analysis revealed a~severe global respiratory failure (Horowitz quotient~73), profound acidosis (pH 7.06), elevated lactate and hemoglobin levels (8.9 mmol/l and 23.7 g/dl, respectively). A chest X\hbox-ray revealed bilateral inhomogeneous opacities. Nitrous oxide was administered to improve the ventilation-perfusion mismatch. In addition, intravenous hydrocortisone was started to address the severe capillary leak syndrome. Follow-up echocardiography showed consistently stable cardiac function at all times. As the lung function deteriorated despite aggressive countermeasures, venovenous extracorporeal membrane oxygenation (ECMO) was initiated 6 h after the initial event. With the aid of ECMO support the invasiveness of mechanical ventilation could be reduced and volume substitution intensified. In the further course, microcirculatory dysfunction and respiratory function gradually improved and ECMO support could be discontinued after 70 h. The patient was extubated on day~9 and discharged to the normal ward on day~13 without any neurological impairments

Energy Resolution Performance of the CMS Electromagnetic Calorimeter

The energy resolution performance of the CMS lead tungstate crystal electromagnetic calorimeter is presented. Measurements were made with an electron beam using a fully equipped supermodule of the calorimeter barrel. Results are given both for electrons incident on the centre of crystals and for electrons distributed uniformly over the calorimeter surface. The electron energy is reconstructed in matrices of 3 times 3 or 5 times 5 crystals centred on the crystal containing the maximum energy. Corrections for variations in the shower containment are applied in the case of uniform incidence. The resolution measured is consistent with the design goals

Hyperon production in proton-sulphur collisions at 200 GeV/c

The WA94 experiment uses the production of strange particles and antiparticles to investigate the properties of hot hadronic matter created in heavy--ion interactions. \PgL, \PagL, \PgXm\ and \PagXp\ particle yields and transverse mass spectra are presented for pS interactions. These results are compared with those from SS interactions. Our results are also compared with those from pW and SW interactions of the WA85 experiment