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Copyright of African Journal of Clinical & Experimental Microbiology is the property of African Journals Online (AJOL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new compact Cylindrical Dielectric Resonator Antenna (CDRA) with a defected ground for ultra-wideband applications is presented. The structure is based on two cylindrical dielectric resonators asymmetrically located with respect to the center of an offset rectangular coupling aperture, with consideration of three and four Dielectric Resonators (DR). The resonant modes generated by the defected ground are studied and investigated. A parametric optimization study of the antenna design has been carried out to determine the optimal dimensions of the defected ground plane, resulting in an impedance bandwidth of over 133% that covers the frequency band from 3.6 GHz to 18.0 GHz. A power gain of about 7.9 dBi has been achieved. Design details and measured and simulated results are presented and discussed.

Grain size analysis, geochemistry, and petrography of sandstones of the Ilaro Formation exposed at the Ajegunle area were investigated to infer provenance, transportation history, tectonic setting, paleoenvironment, and degree of palaeoweathering of the sediments. Selected sandstones were analyzed, and the major, trace, and rare earth elements were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results from the granulometric analysis showed that sandstones were deposited in fluvial conditions. The sandstones exhibit a coarse-grained texture, displaying poor sorting and being texturally immature. The petrographic analysis indicated that quartz was predominant, whereas opaque minerals, muscovite, and ferruginous ground mass were present in smaller quantities. The sandstones can be geochemically classified as arkose and subarenite. The sandstones have an average composition of SiO2 (82.87%) and Al2O3 (9.49%), while K2O, Na2O, MgO, CaO, and P2O5 have <1% each. The elevated Al2O3 content is associated with the lithic fragment composition, whereas the low concentrations of MgO (mean 0.03%), Na2O (mean 0.008%), and K2O (mean 0.04%) suggest chemical destruction in an oxidizing environment. The angularity of the grains indicated a short transportation history very close to the provenance. Bivariate and discriminant plots from major elements and trace elements suggest the sandstones were non-marine and sourced from intermediate rocks. The sandstones were deposited in an oxic-dyoxic condition under a humid climate and passive or active continental margins. The average values of the weathering indices indicate an intense degree of chemical weathering. [ABSTRACT FROM AUTHOR]

A very compact microstrip reconfigurable filter for fourth-generation (4G) and sub-6 GHz fifth-generation (5G) systems using a new hybrid co-simulation method is presented in this manuscript. The basic microstrip design uses three coupled line resonators with λ/4 open-circuited stubs. The coupling coefficients between the adjacent and non-adjacent resonators are used to tune the filter at the required center frequency to cover the frequency range from 2.5 to 3.8 GHz. The coupling coefficient factors between the adjacent resonators are adjusted to control and achieve the required bandwidth, while the input and output external quality factors are adjusted to ensure maximum power transfer between the input and output ports. Two varactor diodes and biasing circuit components are selected and designed to meet the targeted performance for the tunable filter. The impedance bandwidth is maintained between 95 and 115 MHz with measured return losses of more than 17 dB and measured insertion loss of less than 1 dB. Computer simulation technology (CST) is utilized to design and optimize the presented reconfigurable filter, with hybrid co-simulation technique, using both CST microwave studio (MWS) and CST design studio (DS), is applied to build the model by considering the SPICE representation for the varactor switches and all electronic elements of the biasing circuit. The introduced reconfigurable microstrip filter is also fabricated using a Rogers RO3010 material with a relative dielectric constant of 10.1 and it is printed on a very compact size of 13 × 8 × 0.81 mm3. An excellent agreement is obtained between the simulation and measurement performance.

This paper presents a new compact microstrip filtering antenna with modified shaped slots to improve the impedance bandwidth. The proposed microstrip filtering antenna consists of three parts: the monopole radiating patch antenna; the Stepped Impedance Resonator (SIR) filter; and the feeding microstrip line. The designed structure is achieved on one-sided glass epoxy FR-4 substrate with dielectric constant εr = 4.4 and thickness h = 1.6 mm. The design procedure of the proposed filtering antenna starts from the second-order Chebyshev low pass filter (LPF) prototype. The achieved results show an excellent performance of S11-parameter with broadside antenna gain on +z-direction. Having two transmission zeros at 5.4 GHz and 7.7 GHz, good skirt selectivity and a wide-band impedance bandwidth of about 1.66 GHz makes the designed filtering antenna suitable for high-speed data communications. Both the simulation results generated by using the Computer Simulation Technology (CST) software package and the measurement achieved by using a vector network analyzer (HP 8510C) and the anechoic chamber show good agreement.

Summary: This paper proposes a miniature two‐element Multiple Input Multiple Output (MIMO) antenna dedicated to UWB applications. The proposed MIMO design has a very low profile of 30 × 20 × 1.6 mm3. The proposed antenna is carefully designed and optimized using HFSS simulation software. As a proof of concept, the proposed design is realized and experimentally tested for MIMO applications. The proposed structure, printed on an FR4 substrate, comprises two symmetrical elliptical conductive patches on the upper side and a modified ground plane on the lower one. Each radiating element includes six elliptical rings. The modified ground plane consists of a T‐shaped strip and two semielliptical slots etched opposite the feed line. All the parameters of the design are carefully optimized to achieve an ultrawide bandwidth antenna spanning from (136.08%) 3.1 to 16.3 GHz. The results are discussed and analyzed in terms of bandwidth, gain, efficiency, radiation pattern, diversity gain, envelope correlation coefficient (ECC), total active reflection coefficient (TARC), and mean effective gain (MEG). All simulated results are found to be in good accordance with experiments. The design reveals attractive features for UWB applications. A good isolation (17 dB) between the two radiators is achieved despite the close proximity using the suggested ground plane geometry. [ABSTRACT FROM AUTHOR]

Abstract Background Vitamin A (VA) deficiency is widespread in sub-Saharan Africa and school-age children are a vulnerable group. In Burkina Faso, the production and consumption of red palm oil (RPO) is being promoted as a food supplement for VA. The objective of the study was to assess the impact on serum retinol of adding RPO to school lunch in two test zones of Burkina Faso. Methods Over one school year, 15 ml RPO was added to individual meals 3 times a week in selected primary schools in two sites. Serum retinol was measured with HPLC at baseline and exactly 12 months later to take account of seasonality. A simple pre-post test design was used in the Kaya area (north-central Burkina), where 239 pupils from 15 intervention schools were randomly selected for the evaluation. In Bogandé (eastern Burkina), 24 schools were randomised for the controlled intervention trial: 8 negative controls (G1) with only the regular school lunch; 8 positive controls (G2) where the pupils received a single VA capsule (60 mg) at the end of the school year; and 8 schools with RPO through the school year (G3). A random sample of 128 pupils in each school group took part in the evaluation. Results In Kaya, serum retinol went from 0.77 ± 0.37 μmol/L at baseline to 1.07 ± 0.40 μmol/L one year later (p < 0.001). The rate of low serum retinol ( Conclusion RPO given regularly in small amounts appears highly effective in the reduction of VA deficiency. RPO deserves more attention as a food supplement for VA and as a potential source of rural income in Sahelian countries.

Copyright of Journal de la Société Ouest-Africaine de Chimie is the property of West African Chemical Society / Societe Ouest Africaine de Chimie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tin and bismuth powders were used to prepare the Sn40–Bi60 [wt%] mixture. The mixed powders were mechanically alloyed by processing in the high speed milling machine for 2, 4, and 6 h, respectively. When the milling process had been completed, all the resulting material was annealed and analyzed by XRD. The comparision of the results show, that the alloy is fully formed after 6 hours milling time. Differential scanning calorimeter was used to show the uniformity of the prepared alloy. SEM micrographs reflect the micro structure of the specimens. EDS analysis unveils that the alloy phase is very close to the assumed Sn40–Bi60 [wt%]. Mechanical properties evaluated by the micro hardness show the best results for 6 h milling time and 8 h annealing at 100 °C. [ABSTRACT FROM AUTHOR]

Composites of polyaniline-polyethylene-copper were prepared using different weight percentage of nano copper particles of 100 nm size. X-ray diffraction and Fourier transform infrared spectroscopy were done to identify the crystal structure of prepared polyaniline and polyaniline-polyethylene-Cu, respectively. Electrical properties for all the combinations of 5, 10, 15, 20, and 25 wt% copper were examined as electrical conductivity, capacitance, and dielectrical constant. The remarkable improvement in all the electrical properties were indicated after adding nano copper particles, accept the combination P-Ani-5 wt% Cu. Scanning electron microscopy results confirm the dispersion of nano copper particles through their microstructure. [ABSTRACT FROM AUTHOR]

Mice deficient in TMEM218 (Tmem218–/–) were generated as part of an effort to identify and validate pharmaceutically tractable targets for drug development through large-scale phenotypic screening of knockout mice. Routine diagnostics, expression analysis, histopathology, and electroretinogram analyses completed on Tmem218–/–mice identified a previously unknown role for TMEM218 in the development and function of the kidney and eye. The major observed phenotypes in Tmem218–/– mice were progressive cystic kidney disease and retinal degeneration. The renal lesions were characterized by diffuse renal cyst development with tubulointerstitial nephropathy and disruption of tubular basement membranes in essentially normal-sized kidneys. The retinal lesions were characterized by slow-onset loss of photoreceptors, which resulted in reduced electroretinogram responses. These renal and retinal lesions are most similar to those associated with nephronophthisis (NPHP) and retinitis pigmentosa in humans. At least 10% of NPHP cases present with extrarenal conditions, which most often include retinal degeneration. Senior-Løken syndrome is characterized by the concurrent development of autosomal recessive NPHP and retinitis pigmentosa. Since mutations in the known NPHP genes collectively account for only about 30% of NPHP cases, it is possible that TMEM218 could be involved in the development of similar ciliopathies in humans. In reviewing all other reported mouse models of NPHP, we suggest that Tmem218–/–mice could provide a useful model for elucidating the pathogenesis of cilia-associated disease in both the kidney and the retina, as well as in developing and testing novel therapeutic strategies for Senior-Løken syndrome. [ABSTRACT FROM PUBLISHER]

In this article, a planar inverted-FF antenna with suspended rectangular feeding mechanism is presented for lower band ultra-wideband and IEEE 802.11a wireless local area network applications. By manipulating the optimum strong electromagnetic coupling distance between driven and parasitic F-shaped radiators on a small ground plane, two closely separate resonances can be merged to form a wide impedance bandwidth of 73.7% (3.0-6.5 GHz) at |S| < −10 dB. The overall occupied antenna volume is 30 × 15 × 3 mm to satisfy the size requirement of modern wireless devices. The impact of the different antenna geometry parameters on the antenna performance is studied. The corresponding measured radiation patterns, gains and group delays are given to fully characterize the performance of this antenna. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26189 [ABSTRACT FROM AUTHOR]

Background: Vitamin A (VA) deficiency is widespread in sub-Saharan Africa and school-age children are a vulnerable group. In Burkina Faso, the production and consumption of red palm oil (RPO) is being promoted as a food supplement for VA. The objective of the study was to assess the impact on serum retinol of adding RPO to school lunch in two test zones of Burkina Faso. Methods: Over one school year, 15 ml RPO was added to individual meals 3 times a week in selected primary schools in two sites. Serum retinol was measured with HPLC at baseline and exactly 12 months later to take account of seasonality. A simple pre-post test design was used in the Kaya area (north-central Burkina), where 239 pupils from 15 intervention schools were randomly selected for the evaluation. In Bogande (eastern Burkina), 24 schools were randomised for the controlled intervention trial: 8 negative controls (G1) with only the regular school lunch; 8 positive controls (G2) where the pupils received a single VA capsule (60 mg) at the end of the school year; and 8 schools with RPO through the school year (G3). A random sample of 128 pupils in each school group took part in the evaluation. Results: In Kaya, serum retinol went from 0.77 ± 0.37 µmol/L at baseline to 1.07 ± 0.40 µmol/L one year later (p < 0.001). The rate of low serum retinol (<0.7 µmol/L) declined from 47.2% to 13.1%. In Bogande, serum retinol increased significantly (p < 0.001) only in the capsule and RPO groups, going from 0.77 ± 0.28 to 0.98 ± 0.33 µmol/L in the former, and from 0.82 ± 0.3 to 0.98 ± 0.33 µmol/L in the latter. The rate of low serum retinol went from 46.1 to 17.1% in the VA capsule group and from 40.4% to 14.9% in the RPO group. VA-deficient children benefited the most from the capsule or RPO. Female sex, age and height-for-age were positively associated with the response to VA capsules or RPO. Conclusion: RPO given regularly in small amounts appears highly effective in the reduction of VA deficiency. RPO deserves more attention as a food supplement for VA and as a potential source of rural income in Sahelian countries. [ABSTRACT FROM AUTHOR]

Superdeformed bands in 88Mo and 89Tc were populated using 40Ca-induced fusion-evaporation reactions on 58Ni at a beam energy of 185MeV. Gamma-rays emitted in the reactions were detected using the Gammasphere spectrometer, in coincidence with charged particles detected by the Microball array. A new superdeformed band was assigned to the nucleus 88Mo, leading to a revisit of earlier configuration assignments for superdeformed structures in this nucleus. In particular, the theoretical interpretation of a pair of identical (isospectral) superdeformed bands in 88Mo/89Tc is discussed. The configurations that are assigned to the four SD bands belonging to 88Mo have properties that are predicted to be significantly affected by pair correlations. [ABSTRACT FROM AUTHOR]

A very compact microstrip reconfigurable filter for fourth-generation (4G) and sub-6 GHz fifth-generation (5G) systems using a new hybrid co-simulation method is presented in this manuscript. The basic microstrip design uses three coupled line resonators with λ/4 open-circuited stubs. The coupling coefficients between the adjacent and non-adjacent resonators are used to tune the filter at the required center frequency to cover the frequency range from 2.5 to 3.8 GHz. The coupling coefficient factors between the adjacent resonators are adjusted to control and achieve the required bandwidth, while the input and output external quality factors are adjusted to ensure maximum power transfer between the input and output ports. Two varactor diodes and biasing circuit components are selected and designed to meet the targeted performance for the tunable filter. The impedance bandwidth is maintained between 95 and 115 MHz with measured return losses of more than 17 dB and measured insertion loss of less than 1 dB. Computer simulation technology (CST) is utilized to design and optimize the presented reconfigurable filter, with hybrid co-simulation technique, using both CST microwave studio (MWS) and CST design studio (DS), is applied to build the model by considering the SPICE representation for the varactor switches and all electronic elements of the biasing circuit. The introduced reconfigurable microstrip filter is also fabricated using a Rogers RO3010 material with a relative dielectric constant of 10.1 and it is printed on a very compact size of 13 × 8 × 0.81 mm3. An excellent agreement is obtained between the simulation and measurement performance. [ABSTRACT FROM AUTHOR]

Summary: Recently, a new scheme of conventional PID (Proportional Integral Derivative) controller has been utilized in different electrical drives for speed control. This paper presents an optimal P IλDμ controller with 2DOF and anti‐windup techniques based on PSO optimization to produce the proposed controller which is exploited in order to control the velocity control of LIM. A three‐phase inverter with SVPWM technique that is depended on approach of IFOC method is exploited to obtain the necessary output voltage supplied to the main windings of the LIM in order to control the velocity with minimum harmonics and good characteristics. The end effect is taken into account in dq axis equivalent circuit. Computed investigations show that the proposed controller is efficient in improving motor performance. [ABSTRACT FROM AUTHOR]

Purpose: Drugs that are administered by parenteral route must be apyrogenic. The aim of this study was to develop an in vitro endotoxin test for liquid crystalline gels for use as implants, using a monoolein-water liquid crystalline gel as a model. Methods: The gel-clot technique was used. The gel was dissolved first in isopropyl myristate, and the endotoxins were extracted with water for bacterial endotoxin test. Tests for the labelled lysate sensitivity and interfering factors were performed to validate the developed method. The limit of detection of endotoxin in the gel was also determined. Results: The labelled lysate sensitivity was confirmed. It was not influenced by the presence of extracts from the gels. Endotoxins in the contaminated test gels were completely extracted. Endotoxin concentration in the tested gels was below the calculated threshold endotoxin level. Conclusion: A method to perform in vitro endotoxins test of liquid crystalline gels was successfully developed and validated. Application of the technique to gels currently being developed in our laboratories indicate that the gels were apyrogenic. [ABSTRACT FROM AUTHOR]