IDENTIFICATION AND PLANT INTERACTION OF A PHYLLOBACTERIUM SP, A PREDOMINANT RHIZOBACTERIUM OF YOUNG SUGAR-BEET PLANTS

The second most abundant bacterium on the root surface of young sugar beet plants was identified as a Phyllobacterium sp. (Rhizobiaceae) based on a comparison of the results of 39 conventional identification tests, 167 API tests, 30 antibiotic susceptibility tests, and sodium dodecyl sulfate-polyacrylamide gel electrophoretic fingerprints of total cellular proteins with type strains of Phyllobacterium myrsinacearum and Phyllobacterium rubiacearum. It was found on 198 of 1,100 investigated plants between the 2nd and 10th leaf stage on three different fields in Belgium and one field in Spain. Densities ranged from 2 × 10(4) to 2 × 10(8) CFU/g of root. Five isolates exerted a broad-spectrum in vitro antifungal activity. DNA-DNA hybridizations showed that Phyllobacterium sp. does not contain DNA sequences that are homologous with the attachment genes chvA, chvB, the transferred-DNA (T-DNA) hormone genes iaaH and ipt from Agrobacterium tumefaciens, iaaM from A. tumefaciens and Pseudomonas savastanoi, or the nitrogenase genes nifHDK from Klebsiella pneumoniae. Phyllobacterium sp. produces indolylacetic acid in in vitro cultures and induces auxinlike effects when cocultivated with callus tissue of tobacco. When Phyllobacterium sp. was transformed with a Ti plasmid derivative, it gained the capacity to induce tumors on Kalanchoe daigremontiana. The potential role of Phyllobacterium sp. in this newly recognized niche is discussed

Titanium mesh reconstruction of a dog's cranium after multilobular osteochondrosarcoma resection

An eleven-year-old cavalier King Charles spaniel was presented with a large mass arising from the sagittal crest of the skull. Computed tomography also revealed an intracranial component. A histological diagnosis of multilobular osteochondrosarcoma grade 1 was made from surgical biopsies. Since this tumor type has a moderate aggressive biological behavior characterized by a slow growth, compression of adjacent structures, and only a 30% metastatic rate, surgical resection was performed. A wide partial craniectomy was performed, the skull defect was reconstructed with a designated custom designed titanium mesh and the skin defect closed with a local subdermal plexus flap technique. Histologic evaluation indicated clean surgical margins, which may lead to a long-term survival in this low-grade tumor. Approximately seventeen months after surgical resection, the dog showed no signs of local tumor recurrence or metastasis

Missing Pixel Correction Algorithm for Image Sensors

We describe a compact algorithm that can on the fly detect and correct isolated missing pixels in the output stream of an image sensor, without significantly degrading the image quality. The algorithm is in essence a small kernel non-linear filter. It is based on the prediction of the allowed range of gray values for a pixel, from the gray values of the neighborhood of that pixel. A few examples will illustrate the effect of the algorithm on realistic images. 1. IMAGE SENSOR PIXEL DEFECTS AND IMAGE QUALITY One of the most important specifications of an image sensor is the "cosmetic quality": a sensor's image should be flawless. Unfortunately, the technology is not perfect. Due to processing imperfections, statistics, etc., a finite number of pixels in a sensor array will be defective (hard faults) or yield a signal that deviates visibly from the "exact" pixel gray value (soft faults). Such faults appear as white or black (or gray) points in the image. For a human observer, these tend..

Near-100 % fill factor standard CMOS active pixel

Introduction One major drawback of active pixel sensors and, to a lesser extent, of CMOS passive pixels or photo diode arrays too, is that a significant part of the pixel's surface is used for readout circuitry, which is not part of the light receptor or photo diode. Light falling on these regions is collected by the junctions of this circuitry. This essentially is the reason for the low fill factor problem of active pixel sensors. 2. Proposed pixel structure A method to raise the fill factor should manage to get all (or a large part) of the photo generated charge into the collection junction, instead of into the unrelated junctions. We have realised this by placing a small but effective electrostatic barrier between the photo sensitive volume and the unrelated junctions, which is absent between the photo sensitive volume and the useful junction (fig. 1). n++ n++ n p+ p++ (substrate) p- potential minimum unrelated circuitry photo diode ee -

Offset-Free Offset Correction for Active Pixel Sensors

Introduction The output signal of active pixels has a non-uniformity caused by technological variations of the electronic components composing the pixel. If no precautions are taken, this non-uniformity (fixed pattern noise or FPN) is seen as a "snow-like" shade over the image. We describe a method to improve the reading of active pixels, so that this FPN is cancelled, with as final result a better cosmetic quality of the image. Several solutions to this problem have been proposed in literature. We described a technique based upon shifting the threshold voltage of the source follower transistor in the pixel [1] and a correction technique with a dedicated co-processor [2]. The solution proposed here is a correlated double sampling technique, which is a widespread technique to tackle this problem for integrating pixels [3, 4, 5]. For this purpose, it must be possible to bring the active pixels in a reference state that corresponds to a known amount of collected

X-ray Photon Counting and Two-Color X-ray Imaging Using Indirect Detection

In this paper, we report on the design and performance of a 1 cm2, 90 × 92-pixel image sensor. It is made X-ray sensitive by the use of a scintillator. Its pixels have a charge packet counting circuit topology with two channels, each realizing a different charge packet size threshold and analog domain event counting. Here, the sensor’s performance was measured in setups representative of a medical X-ray environment. Further, two-energy-level photon counting performance is demonstrated, and its capabilities and limitations are documented. We then provide an outlook on future improvements

Imaging of iatrogenic spinal infection

Spinal infection may occur due to iatrogenic causes. Its pathogenesis, clinical presentation, management, various imaging techniques, and its application in instrumented and noninstrumented spines are discussed. We provide an overview of the typical infection locations and its imaging correlates, such as spondylodiscitis, epidural and paravertebral abscesses, facet joint infection, and myelomeningitis. Iatrogenic spinal infection should be differentiated from postoperative fluid collections, such as hematoma, seroma, and pseudomeningocele