474 research outputs found
âAlright on the night?' Envisioning a ânight time economyâ in the Thames Gateway,
Providing a comprehensive overview and critique of the Thames Gateway plan, this volume examines the impact of urban planning and demographic change on East London's material and social environment
On spatial adaptivity and interpolation when using the method of lines
The solution of time-dependent partial differential equations with discrete time static remeshing is considered within a method of lines framework. Numerical examples in one and two space dimensions are used to show that spatial interpolation error may have an important impact on the efficiency of integration. Analysis of a simple problem and of the time integration method is used to confirm the experimental results and a computational test for monitoring the impact of this error is derived and tested
The use of impregnated curtains does not affect antibody responses against Plasmodium falciparum and complexity of infecting parasite populations in children from Burkina Faso
Abstract
In Burkina Faso, where malaria is hyper-endemic and transmission intensity is very high, the majority of malaria-related morbidity and mortality occurs in children less than 5 years of age. A control measure such as the use of insecticide-treated curtains (ITC) significantly reduces transmission of malaria infection. Concerns remain whether reduced transmission intensity may lead to a delay in the development of immunity in younger children and even to a partial loss of already acquired immunity. In this study, the levels of P. falciparum-specific IgG subclasses, the number of infecting parasite clones determined by PCR-based
genotyping of the msp2 gene and the parasite density were analysed in 154 asymptomatic children (3â6 years) living in 16 villages (8 with and 8 without ITC) in the vicinity of Ouagadougou, the capital of Burkina Faso. In addition, the parasite inhibitory effects of Ig fractions, prepared from selected children, in co-operation with normal human monocytes were studied. Blood samples from asymptomatic ITC-users showed a significant decrease in P. falciparum prevalence as well as in parasite density. However, no significant difference was observed in P. falciparum-specific antibodies or in parasite multiplicity of infection between the two
groups. Furthermore, Ig fractions from children of both groups showed similar levels of inhibitory activity against autologous parasite growth both on their own and in co-operation with monocytes.
© 2004 Elsevier B.V. All rights reserved.
Keywords: Wild isolate of P. falciparum; Insecticide-treated curtains; Immunit
Effect of Phosphate Group Addition on the Properties of Denture Base Resins
Statement of problem
Acrylic resins are prone to microbial adherence, especially by Candida albicans. Surface-charged resins alter the ionic interaction between the denture resin and Candida hyphae, and these resins are being developed as a means to reduce microbial colonization on the denture surface. Purpose
The purpose of this study was to investigate the physical and mechanical properties of phosphate-containing polymethyl methacrylate resins for their suitability as a denture material. Material and methods
Using PMMA with cross-linker (Lucitone 199) as a control, 4 experimental groups containing various levels of phosphate with and without cross-linker were generated. The properties examined were impact strength, fracture toughness, wettability (contact angle), and resin bonding ability to denture teeth. Impact strength was tested in the Izod configuration (n=16), and fracture toughness (n=13) was measured using the single-edge notched bend test. Wettability was determined by calculating the contact angle of water on the material surface (n=12), while ISO 1567 was used for bonding ability (n=12). The data were analyzed by 1- and 2-way ANOVA (α=.05). Results
A trend of increased hydrophilicity, as indicated by lower contact angle, was observed with increased concentrations of phosphate. With regard to the other properties, no significant differences were found when compared with the control acrylic resin. Conclusions
No adverse physical effect due to the addition of a phosphate-containing monomer was found in the acrylic denture resins. Additional mechanical and physical properties, biocompatibility, and clinical efficacy studies are needed to confirm the in vivo anti-Candida activity of these novel resins
Longitudinal spin-relaxation in nitrogen-vacancy centers in electron irradiated diamond
We present systematic measurements of longitudinal relaxation rates ()
of spin polarization in the ground state of the nitrogen-vacancy (NV) color
center in synthetic diamond as a function of NV concentration and magnetic
field . NV centers were created by irradiating a Type 1b single-crystal
diamond along the [100] axis with 200 keV electrons from a transmission
electron microscope with varying doses to achieve spots of different NV
center concentrations. Values of () were measured for each spot as a
function of .Comment: 4 pages, 8 figure
CFAR vibration signal change test and its applications to real-time recognition of developing cracks in jet engine rotors
This paper introduces a new technique for early identification of fatigue cracks, namely the constant false alarm rate (CFAR) test. This test works on the null hypotheses that a target vibration signal is statistically similar to a reference vibration signal. In effect, this is a time-domain signal processing technique that compares two signals, and returns the likelihood whether the two signals are similar or not. The system monitors the vibration signal of the rotor as it cycles, and compares that vibration signal with, say, the original vibration signal. The difference vector reflects the change in vibration over time. As a crack develops, the vector changes in a characteristic way. Thus, it is possible, during CFAR test, to determine whether the two signals are similar or not. Therefore, by comparing a given vibration signal to a number of reference vibration signals (for several crack scenarios) it is possible to state which is the most likely condition of the rotor under analysis. The CFAR test not only successfully identifies the presence of the fatigue cracks but also gives an indication related to the advancement of the crack. This test, despite its simplicity, is an extremely powerful method that effectively classifies different vibration signals, allowing for its safe use as another condition monitoring techniqu
Galvanic Corrosion between Various Combinations of Orthodontic Brackets and Archwires
Introduction: The purpose of this study was to compare galvanic currents generated by different combinations of commonly used brackets and archwires.
Methods: As-received stainless steel, nickel-titanium, and betatitanium wires were coupled to stainless steel and titanium brackets in an artificial saliva medium. The galvanic current and amount of charge transferred for each pair were monitored with a zero resistance ammeter for 10 hours.
Results: Two-way analysis of variance (ANOVA) showed a significant difference in charge and galvanic currents when factored for type of bracket (P\0.001), but no significant difference between them when factored by type of wire (P .0.05). Specifically, a brazed stainless steel bracket was significantly greater in charge transferred and 10-hour galvanic current than metal injection molded stainless steel and titanium brackets (P\0.001), which were not different from each other (P .0.05).
Conclusions: The method of bracket manufacturing might be of equal or more relevance to galvanic corrosion susceptibility than bracket composition
Prohibition on research involving psychiatric patients subject to coercion
This paper compares legislation on clinical research conducted on patients subject to coercion in the Scandinavian countries and the UK, examines it from a human rights perspective, and problematizes the Danish legal model as the only one employing a total ban on this kind of research. Reference is made to the consequences to evidence-based psychiatric care improvements and international ethical principle statements generally entitling psychiatric patients to treatment under similar ethical and scientific conditions as patients with other illnesses, given the absolute premise that the patient does not object to research participation and always retains the right to withdraw
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