Design of a wideband miniature dielectric-filled waveguide antennafor collision-avoidance radar

This article presents a theoretical and experimental study of the design of a miniaturized wideband dielectric-filled waveguide (DFW) antenna. The operational frequency is X band, i.e., 9.0⩽f⩽10.5 GHz. The desired bandwidth is 1.5 GHz. The antenna uses an air-gap matching network to reduce its high aperture reflection. In order to ease the integration with antenna circuits and to increase the bandwidth, two E-plane steps are used. The antenna is designed to have -3 dB beamwidths of 60° and 100° for the E- and H-plane patterns, respectively. An input reflection of less than -10 dB for the desired bandwidth is observed. The gain of the antenna is 7 dBi. A cross-polar level of less than -25 dB is achieved. This article discusses the mathematical model for input reflection, the design scenarios, and the experimental results     

Association of Ligamentum Flavum Hypertrophy with Adolescent Idiopathic Scoliosis Progression—Comparative Microarray Gene Expression Analysis

The role of the ligamentum flavum (LF) in the pathogenesis of adolescent idiopathic scoliosis (AIS) is not well understood. Using magnetic resonance imaging (MRI), we investigated the degrees of LF hypertrophy in 18 patients without scoliosis and on the convex and concave sides of the apex of the curvature in 22 patients with AIS. Next, gene expression was compared among neutral vertebral LF and LF on the convex and concave sides of the apex of the curvature in patients with AIS. Histological and microarray analyses of the LF were compared among neutral vertebrae (control) and the LF on the apex of the curvatures. The mean area of LF in the without scoliosis, apical concave, and convex with scoliosis groups was 10.5, 13.5, and 20.3 mm², respectively. There were significant differences among the three groups (p < 0.05). Histological analysis showed that the ratio of fibers (Collagen/Elastic) was significantly increased on the convex side compared to the concave side (p < 0.05). Microarray analysis showed that ERC2 and MAFB showed significantly increased gene expression on the convex side compared with those of the concave side and the neutral vertebral LF cells. These genes were significantly associated with increased expression of collagen by LF cells (p < 0.05). LF hypertrophy was identified in scoliosis patients, and the convex side was significantly more hypertrophic than that of the concave side. ERC2 and MAFB genes were associated with LF hypertrophy in patients with AIS. These phenomena are likely to be associated with the progression of scoliosis.     

Control of food spoilage fungi by ethanol

This review discusses the effects of ethanol on the inhibition of growth and germination of fungi and on the inactivation of fungal spores. After a brief survey on the impact of spoilage fungi on the economy and food quality, the major applications of ethanol in controlling fruit decay and extending the shelf-life of food products are reviewed. Many parameters including minimum inhibitory concentration (MIC) and D-values for various moulds are included. The thermodynamic relationship between the liquid phase and the headspace and the mode of action of ethanol on fungi are explained. Due to their promising use as a fumigant, special attention is paid to ethanol vapours.     

Cognitive amplify‐and‐forward relay networks with beamforming under primary user power constraint over Nakagami‐m fading channels

In this paper, we analyze the performance of cognitive amplify‐and‐forward (AF) relay networks with beamforming under the peak interference power constraint of the primary user (PU). We focus on the scenario that beamforming is applied at the multi‐antenna secondary transmitter and receiver. Also, the secondary relay network operates in channel state information‐assisted AF mode, and the signals undergo independent Nakagami‐m fading. In particular, closed‐form expressions for the outage probability and symbol error rate (SER) of the considered network over Nakagami‐m fading are presented. More importantly, asymptotic closed‐form expressions for the outage probability and SER are derived. These tractable closed‐form expressions for the network performance readily enable us to evaluate and examine the impact of network parameters on the system performance. Specifically, the impact of the number of antennas, the fading severity parameters, the channel mean powers, and the peak interference power is addressed. The asymptotic analysis manifests that the peak interference power constraint imposed on the secondary relay network has no effect on the diversity gain. However, the coding gain is affected by the fading parameters of the links from the primary receiver to the secondary relay network. Copyright © 2012 John Wiley & Sons, Ltd.     

Direct Reprogramming and Induction of Human Dermal Fibroblasts to Differentiate into iPS-Derived Nucleus Pulposus-like Cells in 3D Culture

Intervertebral disc (IVD) diseases are common spinal disorders that cause neck or back pain in the presence or absence of an underlying neurological disorder. IVD diseases develop on the basis of degeneration, and there are no established treatments for degeneration. IVD diseases may therefore represent a candidate for the application of regenerative medicine, potentially employing normal human dermal fibroblasts (NHDFs) induced to differentiate into nucleus pulposus (NP) cells. Here, we used a three-dimensional culture system to demonstrate that ectopic expression of MYC, KLF4, NOTO, SOX5, SOX6, and SOX9 in NHDFs generated NP-like cells, detected using Safranin-O staining. Quantitative PCR, microarray analysis, and fluorescence-activated cell sorting revealed that the induced NP cells exhibited a fully differentiated phenotype. These findings may significantly contribute to the development of effective strategies for treating IVD diseases.     

Detection of thermophilic Campylobacter spp. in blood-free enriched samples of inoculated foods by the polymerase chain reaction

The detection of thermophilic Campylobacter spp., as represented by Campylobacter jejuni, by the polymerase chain reaction (PCR) was investigated and compared with the selective agar isolation (SAI) method. Stationary-phase cultures of C. jejuni were inoculated into either blood-free enrichment broth (BFEB) or BFEB that contained 10% broccoli, crabmeat, mushroom, raw milk, and raw oyster rinses. Following a 48-h enrichment period, aliquots of food test portions were removed for simultaneous analysis by PCR and SAI. It was determined that the presence of charcoal and iron in the enrichment broth interfered with the PCR assay. Therefore, three DNA extraction techniques were developed and evaluated using a 16S rRNA primer pair in the PCR assay. The 50% end point (DL50) values (determined upon six initial C. jejuni spiking levels) were used to assess the frequency of isolation utilizing PCR versus SAI for the detection of this organism in the enrichment matrices. There were virtually no differences in detection of C. jejuni among enriched samples analyzed by PCR and SAI. Mean DL50 values (n = 3) for plain BFEB, broccoli, crabmeat, mushroom, raw milk, and raw oyster were, respectively, 0.02 (PCR) versus 0.01 (SAI), 0.01 versus 0.06, 0.07 versus 0.04, 0.03 versus 0.08, 0.01 versus 0.01, and 0.01 versus 0.01 CFU/5 g food. Significant variability in the detection limit of C. jejuni by PCR in the food enrichments was observed among DNA extraction techniques. Using 48-h enrichment cultures followed by PCR analysis could save 1 day of the time required for the presumptive identification of C. jejuni in suspected foods.     

Comparison of DNA Extraction and PCR Setup Methods for Use in High-Throughput DNA Barcoding of Fish Species

DNA barcoding is a sequencing-based method that can be used for the identification of fish species in a regulatory setting. The objective of this study was to compare modified versions of three DNA extraction kits (i.e., Qiagen DNeasy Blood and Tissue Kit, Sigma-Aldrich Extract-N-Amp Kit; and Life Technologies MagMax-96 DNA Multi-Sample Kit) and two polymerase chain reaction (PCR) setup methods (manual vs. automated) for use in DNA barcoding, with a focus on minimizing time, costs, and labor. DNA was extracted from 83 fish products using each of the three kits and the results were compared based on sequencing success and sequencing quality parameters. A subset of 14 fish products was also tested in triplicate to compare PCR setup methods. Initially, reduced sequencing success was observed with the MagMax Kit (88 %) compared to the other two kits (95–96 %); however, after PCR and sequencing were repeated for DNA samples that initially failed, all three methods showed very high sequencing success (98–99 %). Overall, the modified Extract-N-Amp Kit offered the greatest reduction in time and costs, while the DNeasy Blood and Tissue Kit produced sequences with the highest quality and highest initial success rates. Automation of the PCR setup process resulted in slightly greater success (100 %) compared to manual PCR setup (98 %), and reduced the potential for human error that may result from manual pipetting. The results of this study demonstrate the advantages of incorporating rapid and/or automated methods into the DNA barcoding workflow, especially with regard to high-throughput operations.     

Development of a Risk-Ranking Framework to Evaluate Potential High-Threat Microorganisms, Toxins, and Chemicals in Food

ABSTRACT:  Through a cooperative agreement with the U.S. Food and Drug Administration, the Institute of Food Technologists developed a risk-ranking framework prototype to enable comparison of microbiological and chemical hazards in foods and to assist policy makers, risk managers, risk analysts, and others in determining the relative public health impact of specific hazard–food combinations. The prototype is a bottom-up system based on assumptions that incorporate expert opinion/insight with a number of exposure and hazard-related risk criteria variables, which are propagated forward with food intake data to produce risk-ranking determinations. The prototype produces a semi-quantitative comparative assessment of food safety hazards and the impacts of hazard control measures. For a specific hazard–food combination the prototype can produce a single metric: a final risk value expressed as annual pseudo-disability adjusted life years (pDALY). The pDALY is a harmonization of the very different dose–response relationships observed for chemicals and microbes. The prototype was developed on 2 platforms, a web-based user interface and an Analytica® model (Lumina Decision Systems, Los Gatos, Calif., U.S.A.). Comprising visual basic language, the web-based platform facilitates data input and allows use concurrently from multiple locations. The Analytica model facilitates visualization of the logic flow, interrelationship of input and output variables, and calculations/algorithms comprising the prototype. A variety of sortable risk-ranking reports and summary information can be generated for hazard–food pairs, showing hazard and dose–response assumptions and data, per capita consumption by population group, and annual p-DALY.