Showing papers by "Applied Science Private University published in 2010"

Intrinsic antibody-dependent enhancement of microbial infection in macrophages: disease regulation by immune complexes.

Abstract: Summary A wide range of microorganisms can replicate in macrophages, and cell entry of these pathogens via non-neutralising IgG antibody complexes can result in increased intracellular infection through idiosyncratic Fcγ-receptor signalling. The activation of Fcγ receptors usually leads to phagocytosis. Paradoxically, the ligation of monocyte or macrophage Fcγ receptors by IgG immune complexes, rather than aiding host defences, can suppress innate immunity, increase production of interleukin 10, and bias T-helper-1 (Th1) responses to Th2 responses, leading to increased infectious output by infected cells. This intrinsic antibody-dependent enhancement (ADE) of infection modulates the severity of diseases as disparate as dengue haemorrhagic fever and leishmaniasis. Intrinsic ADE is distinct from extrinsic ADE, whereby complexes of infectious agents with non-neutralising antibodies lead to an increased number of infected cells. Intrinsic ADE might be involved in many protozoan, bacterial, and viral infections. We review insights into intracellular mechanisms and implications of enhanced pathogenesis after ligation of macrophage Fcγ receptors by infectious immune complexes.

Mechanical and durability properties of concrete using contaminated recycled aggregates

Abstract: The degradation of concrete structures due to chlorides and sulphates penetration is of obvious importance in civil engineering as having major impact on structural durability. In this paper, the results of an investigation on the effect of contaminated crushed concrete aggregates on mechanical properties and durability of recycled concrete are presented. Natural aggregates concrete (NC) slabs were cured in water, sea water, chloride solutions or sulphate solutions and then crushed to obtain virgin and contaminated (polluted) recycled aggregates. The properties of natural (NA) and recycled aggregates (RA) and the mechanical properties and durability performances of a new concrete made from 100% of RA are analysed. The results show that contaminated RA are much sensitive to chlorides than sulphates and are rapidly leached when soaked into water. Significant differences were observed between the properties of original and new concrete and the results clearly show the necessity of taking these contaminations into account.

Electromagnetic mass splittings of the low lying hadrons and quark masses from 2+1 flavor lattice QCD+QED

Abstract: Results computed in lattice QCD+QED are presented for the electromagnetic mass splittings of the low-lying hadrons. These are used to determine the renormalized, nondegenerate, light quark masses. It is found that m{sub u}{sup MS}=2.24(10)(34), m{sub d}{sup MS}=4.65(15)(32), and m{sub s}{sup MS}=97.6(2.9)(5.5) MeV at the renormalization scale 2 GeV, where the first error is statistical and the second systematic. We find the lowest-order electromagnetic splitting (m{sub {pi}{sup +}}-m{sub {pi}{sup 0}}){sub QED}=3.38(23) MeV, the splittings including next-to-leading order, (m{sub {pi}{sup +}}-m{sub {pi}{sup 0}}){sub QED}=4.50(23) MeV, (m{sub K{sup +}}-m{sub K{sup 0}}){sub QED}=1.87(10) MeV, and the m{sub u}{ne}m{sub d} contribution to the kaon mass difference, (m{sub K{sup +}}-m{sub K{sup 0}}){sub (m{sub u}-m{sub d})}=-5.840(96) MeV. All errors are statistical only, and the next-to-leading-order pion splitting is only approximate in that it does not contain all next-to-leading-order contributions. We also computed the proton-neutron mass difference, including for the first time, QED interactions in a realistic 2+1 flavor calculation. We find (m{sub p}-m{sub n}){sub QED}=0.383(68) MeV, (m{sub p}-m{sub n}){sub (m{sub u}-m{sub d})}=-2.51(14) MeV (statistical errors only), and the total m{sub p}-m{sub n}=-2.13(16)(70) MeV, where the first error is statistical, and the second, part of the systematic error. The calculations are carried out on QCD ensembles generated bymore » the RBC and UKQCD collaborations, using domain wall fermions and the Iwasaki gauge action (gauge coupling {beta}=2.13 and lattice cutoff a{sup -1}{approx_equal}1.78 GeV). We use two lattice sizes, 16{sup 3} and 24{sup 3} ((1.8 fm){sup 3} and (2.7 fm){sup 3}), to address finite-volume effects. Noncompact QED is treated in the quenched approximation. The valence pseudoscalar meson masses in our study cover a range of about 250 to 700 MeV, though we use only those up to about 400 MeV to quote final results. We present new results for the electromagnetic low-energy constants in SU(3) and SU(2) partially quenched chiral perturbation theory to the next-to-leading order, obtained from fits to our data. Detailed analysis of systematic errors in our results and methods for improving them are discussed. Finally, new analytic results for SU(2){sub L}xSU(2){sub R}-plus-kaon chiral perturbation theory, including the one-loop logs proportional to {alpha}{sub em}m, are given.« less

Direct Observation of Adsorption-Induced Inactivation of Antibody Fragments Surrounded by Mixed-PEG Layer on a Gold Surface

Abstract: To examine the adsorption behavior of antibody fragments (Fab') directly immobilized on a gold surface through S-Au linkage, analyses by surface plasmon resonance (SPR), fluorometry, and atomic force microscopy (AFM) with an excellent blocking technique by the consecutive treatments of longer-poly(ethylene glycol) (PEG) (MW = 5k) and shorter-PEG (MW = 2k), abbreviated as mixed-PEG layer formation, were performed. The results of the SPR analysis suggest that the adsorption-induced inactivation of the antigen-binding activity of Fab' took place gradually on the gold surface, where the activity disappeared almost completely at 60 min after Fab' immobilization. In contrast, in the case of Fab' coimmobilized by the mixed-PEG layer, 70% of the initial antigen-binding activity of the Fab' was retained even 60 min after the construction of the hybrid surface. Using fluorescein-labeled Fab' (FL-Fab'), fluorescence measurement of the constructed surface was carried out. The fluorescence of the FL-Fab' without any blocking agent on the gold surface was gradually quenched and finally decreased to 40% of the initial intensity 60 min after Fab' immobilization. The decrease in the fluorescence intensity is considered to be caused by the change in the distance between the fluorophores labeled on the Fab' and the gold surface, due to the energy transfer from the fluorophores to the gold surface. In contrast, 75% of the initial intensity was observed on the Fab'/mixed-PEG coimmobilized surface. The results obtained from the SPR and fluorometric analyses correlated well with each other; thus, the surface-induced inactivation of the antigen-binding functionality was presumably due to the conformational and/or orientation change of Fab' on the gold surface. AFM studies provided direct information on the time-dependent decrease in the height of the immobilized Fab' on the gold surface. In contrast, the coimmobilization of densely packed mixed-PEG tethered chains around the Fab' on the gold surface suppressed the decrease in the height of Fab', presumably indicating that the conformational and/or orientation change of Fab' was suppressed by the coimmobilized mixed-PEG layer. The new findings obtained in this study are expected to be useful for the improvement of the antibody fragment method and, thus, for the construction of high-performance immuno-surfaces.

High-Dimensional Neural-Network Technique and Applications to Microwave Filter Modeling

Abstract: Neural networks are useful for developing fast and accurate parametric model of electromagnetic (EM) structures. However, existing neural-network techniques are not suitable for developing models that have many input variables because data generation and model training become too expensive. In this paper, we propose an efficient neural-network method for EM behavior modeling of microwave filters that have many input variables. The decomposition approach is used to simplify the overall high-dimensional neural-network modeling problem into a set of low-dimensional sub-neural-network problems. By incorporating the knowledge of filter decomposition with neural-network decomposition, we formulate a set of neural-network submodels to learn filter subproblems. A new method to combine the submodels with a filter empirical/equivalent model is developed. An additional neural-network mapping model is formulated with the neural-network submodels and empirical/equivalent model to produce the final overall filter model. An H -plane waveguide filter model and a side-coupled circular waveguide dual-mode filter model are developed using the proposed method. The result shows that with a limited amount of data, the proposed method can produce a much more accurate high-dimensional model compared to the conventional neural-network method and the resulting model is much faster than an EM model.

Development of an interval-valued fuzzy linear-programming method based on infinite α-cuts for water resources management

Abstract: An interval-valued fuzzy linear-programming (IVFL) method based on infinite @a-cuts is developed for water resources management in this study. The introduction of interval parameters and interval-valued fuzzy parameters into the objective function and constraints makes it possible for dealing with individual uncertainty and dual uncertainties existing in many real-world cases. A two-step infinite @a-cuts (TSI) solution method is communicated to the solution process to discretize infinite @a-cuts to interval-valued fuzzy membership functions. Application to an agricultural irrigation problem indicates that interval-valued fuzzy sets can represent dual uncertainties in modeling parameters, and the solution method is able to generate decisions with enhanced reliability. It is also indicated that the objective (i.e. system net benefit) can be increased with the growth of violation risk, in association with a set of different allocation schemes. As the key segment of interval-valued fuzzy membership functions that could significantly affect system performance can be identified through the analysis of decision alternatives under different risk levels of constraint violation, the IVFL method provides decision makers flexibility in selecting an appropriate decision scheme according to their preference and practical conditions.

Four Important Onset Pressures for Mutual Interactions between Each of Three Crude Oils and CO2

Abstract: In this paper, mutual interactions between each of three different crude oils and CO2 are experimentally studied. Three crude oils include two light crude oils and one medium crude oil. First, a series of saturation tests are conducted to determine the onset pressure of asphaltene precipitation for each crude oil−CO2 system. Second, the equilibrium interfacial tension (IFT) between each crude oil and CO2 is measured as a function of the equilibrium pressure. The so-called minimum miscibility pressure (MMP) of each crude oil−CO2 system is determined by applying the vanishing interfacial tension (VIT) technique. Third, the oil-swelling effect and initial strong light-components extraction are observed during the IFT measurements. It is found that the onset pressure of asphaltene precipitation is lower if the asphaltene content of the crude oil is higher. It is also found that the measured equilibrium IFT is reduced almost linearly with the equilibrium pressure in three distinct pressure ranges for the two l...

Rateless Coding on Experimental Temporally Correlated FSO Channels

Abstract: We present a demonstration of two error-correction coding schemes that can successfully operate on a free-space optical (FSO) communication channel subject to atmospheric turbulence. The codes (a puntured Low-density parity-check code and a Raptor code) operate by continuously adapting the information rate to accommodate the varying channel conditions. Because these coding schemes require the use of a feedback channel, we evaluate the bandwidth cost incurred. The evaluation of the codes is performed offline and uses experimental optical signals recorded from an FSO link. We analyze the temporal characteristics of the experimental channels and compare the performance of the codes for different bit rates to asses the effect of temporal correlation and imperfect channel state information.

Vertically-resolved particle size distribution within and above the mixing layer over the Milan metropolitan area

Abstract: . Vertical aerosol profiles were directly measured over the city of Milan during three years (2005–2008) of field campaigns. An optical particle counter, a portable meteorological station and a miniaturized cascade impactor were deployed on a tethered balloon. More than 300 vertical profiles were measured, both in winter and summer, mainly in conditions of clear, dry skies. The mixing height was determined from the observed vertical aerosol concentration gradient, and from potential temperature and relative humidity profiles. Results show that inter-consistent mixing heights can be retrieved highlighting good correlations between particle dispersion in the atmosphere and meteorological parameters. Mixing height growth speed was calculated for both winter and summer showing the low potential atmospheric dispersion in winter. Aerosol number size distribution and chemical composition profiles allowed us to investigate particle behaviour along height. Aerosol measurements showed changes in size distribution according to mixing height. Coarse particle profiles (dp>1.6 μm) were distributed differently than the fine ones (dp

Analytical characteristics of the Roche highly sensitive troponin T assay and its application to a cardio-healthy population

Abstract: BackgroundIt is desirable that current assays for cardiac troponin (cTn) are able to meet the recommended criterion that the diagnosis and risk assessment of patients present with symptoms of myoca...

Symmetry Switch of Cobalt Ferrocyanide Framework by Alkaline Cation Exchange

Abstract: We observed a reversible symmetry switch of a cobalt ferrocyanide framework by the alkaline cation exchange and resultant control of the optical properties at room temperature.

Overlap valence on 2 + 1 flavor domain wall fermion configurations with deflation and low-mode substitution

Abstract: The overlap fermion propagator is calculated on $2+1$ flavor domain-wall fermion gauge configurations on ${16}^{3}\ifmmode\times\else\texttimes\fi{}32$, ${24}^{3}\ifmmode\times\else\texttimes\fi{}64$ and ${32}^{3}\ifmmode\times\else\texttimes\fi{}64$ lattices. With hyper-cubic (HYP) smearing and low eigenmode deflation, it is shown that the inversion of the overlap operator can be expedited by $\ensuremath{\sim}20$ times for the ${16}^{3}\ifmmode\times\else\texttimes\fi{}32$ lattice and $\ensuremath{\sim}80$ times for the ${32}^{3}\ifmmode\times\else\texttimes\fi{}64$ lattice. The overhead cost for calculating eigenmodes ranges from 4.5 to 7.9 propagators for the above lattices. Through the study of hyperfine splitting, we found that the $O({m}^{2}{a}^{2})$ error is small and these dynamical fermion lattices can adequately accommodate quark mass up to the charm quark. A preliminary calculation of the low-energy constant ${\ensuremath{\Delta}}_{\mathrm{mix}}$ which characterizes the discretization error of the pion made up of a pair of sea and valence quarks in this mixed-action approach is carried out via the scalar correlator with periodic and antiperiodic boundary conditions. It is found to be small which shifts a 300 MeV pion mass by $\ensuremath{\sim}10$ to 19 MeV on these sets of lattices. We have studied the signal-to-noise issue of the noise source for the meson and baryon. We introduce a new algorithm with ${Z}_{3}$ grid source and low eigenmode substitution to study the many-to-all meson and baryon correlators. It is found to be efficient in reducing errors for the correlators of both mesons and baryons. With 64-point ${Z}_{3}$ grid source and low-mode substitution, it can reduce the statistical errors of the light quark (${m}_{\ensuremath{\pi}}\ensuremath{\sim}200--300\text{ }\text{ }\mathrm{MeV}$) meson and nucleon correlators by a factor of $\ensuremath{\sim}3--4$ as compared to the point source. The ${Z}_{3}$ grid source itself can reduce the errors of the charmonium correlators by a factor of $\ensuremath{\sim}3$.

The effect of subminimal inhibitory concentrations of antibiotics on virulence factors expressed by Staphylococcus aureus biofilms

Abstract: Aims: The effect of subminimal inhibitory concentrations (sub-MICs) of cefalexin, ciprofloxacin and roxithromycin was investigated on some virulence factors [eg coagulase, Toxic Shock Syndrome Toxin 1 (TSST-1) and biofilm formation] expressed by Staphylococcus aureus biofilms Methods and Results: Biofilms were grown with and without the presence of 1/16 MIC of antibiotics on Sorbarod filters Eluate supernatants were collected, and coagulase and TSST-1 production were evaluated Coagulase production was reduced in eluates exposed to roxithromycin when compared to control, while TSST-1 production was reduced in biofilms exposed to cefalexin and to a lesser extent, ciprofloxacin In addition, the ability of Staph aureus to produce biofilm in microtitre plates in the presence of sub-MIC antibiotics indicated that cefalexin induced biofilm formation at a wide range of sub-MICs TSST-1 produced from the challenged and control biofilms was purified, and its proliferative activity was studied on single cell suspension of mouse splenocytes using MTS/PMS assay No significant difference in the activity between the treated toxin and the control has been observed Conclusions: Antibiotics at sub-MIC levels interfere with bacterial biofilm virulence expression depending on the type and concentration of antibiotic used Significance and Impact of the Study: The establishment of sub-MICs of antibiotics in clinical situations may result in altered virulence states in pathogenic bacteria

A Superiority-Inferiority-Based Inexact Fuzzy Stochastic Programming Approach for Solid Waste Management Under Uncertainty

Abstract: A superiority–inferiority-based inexact fuzzy stochastic programming (SI-IFSP) model was developed for planning municipal solid waste management systems under uncertainty. The SI-IFSP approach represents a new attempt to tackle multiple uncertainties in objective function coefficients which are beyond the capabilities of existing inexact programming methods. Through introducing the concept of fuzzy random boundary interval, SI-IFSP is capable of reflecting multiple uncertainties (i.e., interval values, fuzzy sets, probability distributions, and their combinations) in both the objective function and constraints, leading to enhanced system robustness. The developed SI-IFSP method was applied to a case study of long-term municipal solid waste management. Useful solutions were generated. A number of decision alternatives could be generated based on projected applicable conditions, reflecting the compromise between system optimality and reliability as well as the tradeoffs between economic and environmental objectives. Moreover, the consequences of system violations could be quantified through introducing a set of economic penalties, reflecting the relationships between system costs and constraint violation risks. The results suggest that the proposed SI-IFSP method can explicitly address complexities in municipal solid waste management systems and is applicable to practical waste management problems.

Determination of Swelling and Shrinkage Properties of Undisturbed Expansive Soils

Abstract: Expansive soils exhibit large volume changes when their water content changes. Alternate heave and settlement due to seasonal climatic variations result in distress and damage in civil infrastructure systems. This research focuses on the understanding of swelling and shrinkage phenomenon in the surface layer of expansive soils. Undisturbed field samples were used to capture the effect of in situ conditions (geologically induced fissuring and environmentally caused saturation) on volume change properties of Regina clay. Based on laboratory investigations, the swelling potential and swelling pressure of the native clay at S = 82% were found to be 1.5% and 3.5 kPa, respectively. The swell-shrink path during progressive soil drying followed an S-shaped curve comprising of an initial low structural shrinkage followed by a sharp decline during normal shrinkage and then by a low decrease during residual shrinkage. The soil microstructure correlated well with the observed volume change behaviour as well as with the consistency limits. The presence of fissures in field samples at various degrees of saturation confirmed that the investigated deposit is at an equilibrium condition with respect to the swell-shrink phenomenon. The swelling properties at any initial saturation state were estimated using the free swelling test and the swell-shrink test data in conjunction. The swelling potential increased 12 times (from 2 to 24%) and the swelling pressure increased by two orders of magnitude (from 27 to 2500 kPa) with a change in the degree of saturation from 80% (at the plastic limit) to 60% (at the shrinkage limit).

Glacial Silicic Acid Concentrations in the Southern Ocean

Abstract: Reconstruction of nutrient concentrations in the deep Southern Ocean has produced conflicting results. The cadmium/calcium (Cd/Ca) data set suggests little change in nutrient concentrations during the last glacial period, whereas the carbon isotope data set suggests that nutrient concentrations were higher. We determined the silicon isotope composition of sponge spicules from the Atlantic and Pacific sectors of the Southern Ocean and found higher silicic acid concentrations in the Pacific sector during the last glacial period. We propose that this increase results from changes in the stoichiometric uptake of silicic acid relative to nitrate and phosphate by diatoms, thus facilitating a redistribution of nutrients across the Pacific and Southern Oceans. Our results are consistent with the global Cd/Ca data set and support the silicic acid leakage hypothesis.

Competence assessment of nursing graduates of Jordanian universities

Abstract: This cross-sectional survey assessed the level of competence of nursing graduates of Jordanian universities (2001-2004 cohorts) in relation to the type of university, sex, hospital type, and working area. A convenience sample (n = 258) of full-time nurses (6 months-4 years' experience) was selected from public, private, and teaching hospitals. A specifically designed tool with a rating scale of 1-5 was used to evaluate the nurses' competence in five nursing competencies (management, professionalism, problem-solving, nursing process, and knowledge of basic skills). The findings showed a satisfactory competency level with no significant differences related to the type of university or sex. General ward nurses scored significantly better than those in intensive care units in relation to management, professionalism, and nursing process, while the teaching hospital nurses showed significantly better performance in professionalism and management skills than did the nurses in the other two sectors. We recommend that nurse recruitment policies should consider individual competencies rather than innate characteristics in their selection of employees.

Ant Colony Algorithm for Job Scheduling in Grid Computing

Abstract: Scheduling jobs to resources in grid computing is complicated due to the distributed and heterogeneous nature of the resources. Stagnation in grid computing system may occur when all jobs require or are assigned to the same resources. This will lead to resources having high workload and stagnation may occur if computational times of the processed jobs are high. This paper proposed an enhanced ant colony optimization algorithm for jobs and resources scheduling in grid computing. The proposed ant colony algorithm for job scheduling in the grid environment combines the techniques from Ant Colony System and Max – Min Ant System. The algorithm focuses on local pheromone trail update and the trail limit values. A matrix is used to record the status of the available resources. The agent concept is also integrated in this algorithm for the purpose of updating the grid resource table. Experimental results obtained showed that this is a promising ant colony algorithm for job scheduling in grid environment.

Room-Temperature Coulomb Blockade from Chemically Synthesized Au Nanoparticles Stabilized by Acid--Base Interaction

Abstract: Sub-2-nm-size basic ligand Au nanoparticles were chemically synthesized and chemisorbed on an acidic self-assembled monolayer/Au(111) substrate by acid–base interaction. Coulomb blockade behaviors with clear Coulomb gaps were observed in current–voltage (I–V) and log I–V curves of the chemisorbed Au nanoparticles by scanning tunneling spectroscopy at room temperature. By fitting the measured I(V) and log I(V) to a Coulomb blockade model, we estimated the charging energy of one electron on the Au nanoparticles to be 10 times greater than the thermal energy k T; the tunneling resistance of the Au core–Au(111) surface was evaluated to be 3.5 GΩ ±15%.