Determination of the phosphorus content in potato starch using an energy-dispersive X-ray fluorescence method

Potato starch is unique because of its high starch phosphorus content. The textural characteristics of potato starch change due to the presence of the starch phosphate. Thus, the measurement of phosphorus in potato starch is needed, but conventional methods require a considerable amount of time and labour. In this investigation, a simple and fast analytical procedure has been developed for the determination of the phosphorus content of potato starch with a non-destructive energy dispersive X-ray fluorescence (ED-XRF) technique. Potato starch samples were analyzed as pressed pellets using detection times of 200 s. Reference values, measured by a conventional method, namely, wet chemical analysis, were used to calibrate the ED-XRF. Calibration was done using 20 potato starch samples, and the results were validated using a second set of 15 samples. The results indicated the validity of ED-XRF as a rapid and non-destructive method for the quantitative determination of phosphorus content of potato starch. Based on the combined results of ED-XRF and Rapid Visco-Analyzer (RVA), ED-XRF is promising for predicting the peak viscosity, by RVA, of potato starch paste through the measurement of starch phosphorus content.     

Organization and localization of the dnaA and dnaK gene regions on the multichromosomal genome of Burkholderia multivorans ATCC 17616

The Burkholderia multivorans strain ATCC 17616 carries three circular chromosomes with sizes of 3.4, 2.5, and 0.9 Mb. To reveal the distribution and organization of the genes for fundamental cell functions on the genome of this bacterium, the dnaA and dnaK gene regions of ATCC 17616 were cloned and characterized. The gene organization of the dnaA region was rnpA-rmpH-dnaA-dnaN-gyrB with a single consensus DnaA-binding box (TTATCCACA) between the rmpH and dnaA genes. This intergenic region, however, did not work as an autonomously replicating sequence in ATCC 17616. On the other hand, the gene organization of the dnaK region was grpE-orf1 (gene for thioredoxin homologue)-dnaK-dnaJ-pabB (gene for p-aminobenzoate synthetase component homologue). A putative heat-shock promoter that showed good homology to the sigma32-dependent promoter consensus sequence in Escherichia coli was found upstream of the grpE gene, suggesting that these five genes constitute an operon. In M9 succinate minimal medium the dnaJ mutant grew more slowly than the wild-type strain, indicating that this operon is functional. Pulsed-field gel electrophoresis and Southern blot analyses indicated that both the dnaA and dnaK gene regions exist as single copies on the 3.4 Mb chromosome.     

Suppression of the melanogenesis and cellular antioxidant activity in B16 melanoma cells

The results of antioxidant activities by ORAC assay and CAA assay were evaluated for melanogenesis. Although the antioxidant activity by ORAC was not correlated with the melanogenesis, the samples which showed high antioxidant activity by CAA tended to suppress melanogenesis. Caffeic acid and Citrus depressa juice, which demonstrated inhibitory effects on mela‐nogenesis, had high antioxidant activities but no inhibitory effects on tyrosinase activity. In addition, they inhibited the melanogenesis which was increased by inhibition of catalase activity. These results may suggest that antioxidant activity by CAA can contribute to the suppression of melanogenesis in B16 melanoma.     

An introduction to kernel-based learning algorithms

This paper provides an introduction to support vector machines, kernel Fisher discriminant analysis, and kernel principal component analysis, as examples for successful kernel-based learning methods. We first give a short background about Vapnik-Chervonenkis theory and kernel feature spaces and then proceed to kernel based learning in supervised and unsupervised scenarios including practical and algorithmic considerations. We illustrate the usefulness of kernel algorithms by discussing applications such as optical character recognition and DNA analysis.     

Subspace information criterion for nonquadratic regularizers-Modelselection for sparse regressors

Nonquadratic regularizers, in particular the l(1) norm regularizer can yield sparse solutions that generalize well. In this work we propose the generalized subspace information criterion (GSIC) that allows to predict the generalization error for this useful family of regularizers. We show that under some technical assumptions GSIC is an asymptotically unbiased estimator of the generalization error. GSIC is demonstrated to have a good performance in experiments with the l(1) norm regularizer as we compare with the network information criterion (NIC) and cross- validation in relatively large sample cases. However in the small sample case, GSIC tends to fail to capture the optimal model due to its large variance. Therefore, also a biased version of GSIC is introduced,which achieves reliable model selection in the relevant and challenging scenario of high-dimensional data and few samples.     

Identity of osteoclastogenesis inhibitory factor (OCIF) and osteoprotegerin (OPG): a mechanism by which OPG/OCIF inhibits osteoclastogenesis in vitro

The morphogenesis and remodeling of bone depends on the integrated activity of osteoblasts that form bone and osteoclasts that resorb bone. We previously reported the isolation of a new cytokine termed osteoclastogenesis inhibitory factor, OCIF, which specifically inhibits osteoclast development. Here we report the cloning of a complementary DNA of human OCIF. OCIF is identical to osteoprotegerin (OPG), a soluble member of the tumor-necrosis factor receptor family that inhibits osteoclastogenesis. Recombinant human OPG/OCIF specifically acts on bone tissues and increases bone mineral density and bone volume associated with a decrease of active osteoclast number in normal rats. Osteoblasts or bone marrow-derived stromal cells support osteoclastogenesis through cell-to-cell interactions. A single class of high affinity binding sites for OPG/OCIF appears on a mouse stromal cell line, ST2, in response to 1,25-dihydroxyvitamin D3. An anti-OPG/OCIF antibody that blocks the binding abolishes the biological activity of OPG/OCIF. When the sites are blocked with OPG/OCIF, ST2 cells fail to support osteoclastogenesis. These results suggest that the sites are involved in cell-to-cell signaling between stromal cells and osteoclast progenitors and that OPG/OCIF inhibits osteoclastogenesis by interrupting the signaling through the sites.     

Low‐cost laser disdrometer with the capability of hydrometeor imaging

Precision of microwave precipitation remote sensing is ensured by studying different hydrometeor classes (raindrops, snowflakes, graupel, and so on), shapes, and drop size distribution (DSD). Recently, DSD estimates and hydrometeor classification algorithms using polarimetric radars were proposed. These algorithm developments require a validation tool providing in situ hydrometeor measurement. We are working toward the development of a low‐cost, light‐weight, and disposable ballooning hydrometeor imaging probe with DSD measurement capabilities. This paper describes the performance of a new line‐scanning laser hydrometeor imaging probe (called PROBE) and validates the DSD using a commercially available impact‐type disdrometer. PROBE captures raindrop images with 0.125 mm horizontal resolution and more than six slices at the 33‐kHz slice rate, providing a reasonable raindrop diameter. DSD validation shows that PROBE acquires adequate DSD shapes during every 2‐min interval. These results demonstrate PROBE's performance in hydrometeor imaging and DSD measurement capabilities in a rainfall. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Diffusion bonding of SiC ceramics with interlayers of metallic titanium foils and PVD titanium coatings

Silicon carbide (SiC) is a candidate material for high-temperature structural aerospace applications due to its thermal and mechanical properties. Joining technologies enable the fabrication of complex shaped components needed for such applications. Various interlayers and processing conditions were used to form diffusion bonds between SiC substrates. Interlayers of titanium (Ti) foils and physically vapor deposited Ti coatings were used in the thicknesses of 10 and 20 μm with processing hold times of 1, 2, and 4 h. Polished cross sections of resulting diffusion bonds were analyzed using scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS) and using transmission electron microscopy (TEM). From the TEM analysis, selected-area diffraction patterns for Ti₃SiC₂, Ti₅Si₃C_x, and TiSi₂ were observed. Moreover, TiC and an unknown phase were present in diffusion bonds formed with metallic titanium foil. From the SEM/EDS analyses, intermediate phases of Ti₅Si₃C_x and TiC were found to be present in microcracked diffusion bonds. With the thinner Ti interlayers and/or longer processing time, microcracking was alleviated or eliminated due to the presence of the more stable and lower thermal expansive phases of Ti₃SiC₂ and TiSi₂. Detailed analysis of microstructures and the probable phases that formed in the bonded regions is presented.     

Plasmonic Photoresistor Based on Interconnected Metal-Semiconductor Grating

Metal-semiconductor nanostructures in various configurations are extensively used in photodetection, photocatalysis, and photovoltaics. For photodetection purposes, the working principle is straightforward; on illumination, generated charge carriers in excess lead to a decrease in resistance. Notably, using an interconnected metal-semiconductor grating, it is observed and now reported an opposite response, an increase in the resistance. Such photoresistors are fabricated through wrinkle structuring and oblique angle material deposition methods. It is found that the controlled wrinkling leads to large-area 1D periodic structures with coexisting cracking perpendicular to the grating direction—such cracks are used as connections between the two-point contact measurement through the associated gold layer deposition. An enhanced current reduction is further observed on photoexcitation for an additional deposition of an amorphous titania layer. Subsequently, a discussion on the mechanisms and interaction between hot electron injection, charge carrier recombination, and thermalization is presented. Supported by numerical modeling, the angle-resolved plasmonic modes with the photoresistance can be correlated. The ease of layered deposition of the materials allows one to extend the studies on cavity-based structures with sandwiched titania layers as hotspots. This simple, scalable, and robust fabrication method thus promises an efficient routeway toward photosensor development in which plasmon-mediated hot electrons play a crucial role.