Current concepts - Schistosomiasis

In 1851, Theodor Bilharz described a parasitic infection (bilharzia) that would later be termed schistosomiasis. Currently, 200 million people in 74 countries have this disease; 120 million of them have symptoms, and 20 million have severe illness.1 Schistosomiasis is caused by parasitic trematode worms (schistosomes) that reside in the abdominal veins of their vertebrate definitive hosts. The life cycle of the schistosome is depicted in Figure 1. Schistosomiasis is 1 of the 10 tropical diseases especially targeted for control by the Special Program for Research and Training in Tropical Diseases of the United Nations Development Program, the World Bank, . . . [Full Text of this Article]

The current status of laser applications in dentistry

A range of lasers. is now available for use in dentistry. This paper summarizes key current and emerging applications, for lasers in clinical practice. A major diagnostic application of low power lasers is the detection of caries, using fluorescence elicited from hydroxyapatite or from bacterial by-products. Laser fluorescence is an effective method for detecting and quantifying incipient occlusal and cervical,carious lesions, and with further refinement could be used in the, same manner for proximal lesions. Photoactivated dye techniques have been developed which use low power lasers to elicit a photochemical reaction, Photoactivated dye techniques' can be used to disinfect root canals, periodontal pockets, cavity preparations and sites of peri-implantitis. Using similar principles, more powerful lasers tan be used for photodynamic therapy in the treatment of malignancies of the oral mucosa. Laser-driven photochemical reactions can also be used for tooth whitening. In combination with fluoride, laser irradiation can improve the resistance of tooth structure to demineralization, and this application is of particular benefit for susceptible sites in high caries risk patients. Laser technology for caries' removal, cavity preparation and soft tissue surgery is at a high state of refinement, having had several decades of development up to the present time. Used in conjunction with or as a replacement for traditional methods, it is expected that specific laser technologies will become an essential component of contemporary dental practice over the next decade.

Adolescent risk behaviors and communication research - Current directions

Examples of recent research into adolescent risk behaviors from a variety of disciplines and methodologies, denoting the range of researchers interested in this area and whose interest in communication and language articulates and exemplifies the extent of the field, are surveyed in this article.

gl(2 vertical bar 2) current superalgebra and non-unitary conformal field theory

Motivated by application of current superalgebras in the study of disordered systems such as the random XY and Dirac models, we investigate gl(2\2) current superalgebra at general level k. We construct its free field representation and corresponding Sugawara energy-momentum tensor in the non-standard basis. Three screen currents of the first kind are also presented. (C) 2003 Elsevier B.V. All rights reserved.

Current issues in Social Work Theory

São aqui analisados os discursos sobre as tendências gerais na teoria de Serviço Social. Estes discursos sobre o papel do Serviço Social são tratados no contexto da sociedade, bem como do cliente -assistente sócial -agência. A teoria da prática representa um discurso entre as perspectivas de Serviço Social nos seus aspectos transformacionais, terapêuticos e de ordem social. São também abordadas as suas várias combinações e interacções em todo o tipo de prática e organização de Serviço Social. O discurso sobre a eficácia baseia¬se em estudos comprovados da construção social, potenciação (empowerment), e realismo crítico ainda polémico. A prática reflectiva e crítica constitui os modelos actuais que interligam a teoria e a prática.

Current trends in the global tourism industry: evidence from the United States

Tourism is one of the largest U.S. industries, serving millions of international and domestic tourists yearly. Tourists visit the U.S. to see natural wonders, cities, historic landmarks, and entertainment venues. Americans seek similar attractions as well as recreation and vacation areas. Tourism competes in the global market, so it is important to understand current trends in the U.S. travel industry. Therefore, this article offers insight into important trends and suggests strategies for policy makers involved in the travel and tourism industry.

Impact of flavor-changing neutral current top quark interactions on BR(t -> bW)

We study the effect that flavor-changing neutral current interactions of the top quark will have on the branching ratio of charged decays of the top quark. We have performed an integrated analysis using Tevatron and B-factories data and with just the further assumption that the Cabibbo-Kobayashi-Maskawa matrix is unitary, we can obtain very restrictive bounds on the strong and electroweak flavor-changing neutral current branching ratios Br(t -> qX)< 4.0x10(-4), where X is any vector boson and a sum in q=u, c is implied.

Power Electronics Didactic Modules for Direct Current Machine Control

Several didactic modules for an electric machinery laboratory are presented. The modules are dedicated for DC machinery control and get their characteristic curves. The didactic modules have a front panel with power and signal connectors and can be configurable for any DC motor type. The three-phase bridge inverter proposed is one of the most popular topologies and is commercially available in power package modules. The control techniques and power drives were designed to satisfy static and dynamic performance of DC machines. Each power section is internally self-protected against misconnections and short-circuits. Isolated output signals of current and voltage measurements are also provided, adding versatility for use either in didactic or research applications. The implementation of such modules allowed experimental confirmation of the expected performance.

Comparing a current-carrying circular wire with polygons of equal perimeter: Magnetic field versus magnetic flux

We compare the magnetic field at the centre and the self-magnetic flux through a current-carrying circular loop, with those obtained for current-carrying polygons with the same perimeter. As the magnetic field diverges at the position of the wires, we compare the self-fluxes utilizing several regularization procedures. The calculation is best performed utilizing the vector potential, thus highlighting its usefulness in practical applications. Our analysis answers some of the intuition challenges students face when they encounter a related simple textbook example. These results can be applied directly to the determination of mutual inductances in a variety of situations.