Influence of Filtering Techniques on Holographic Images

Broadband Holography has become a powerful tool in computerized non-destructive testing. Interpretation of images, however, is difficult due to the fact that perfect imaging of flaw sizes is impossible until now. The situation is even more complex, since multiple scattering, wave mode conversions, and inhomogeneities in the material give rise to artifacts in the holographic image. Thus, signal and data processing techniques at different levels of the signal flow path may help improve the situation. Within this paper the following methods are discussed: (1) Inverse filtering. Inverse filters improve echo shape and duration. This in turn influences lateral and axial resolutions of the image. Since inverse filtering is known to be an ill posed problem we apply a standard Tychonoff regularization. It turns out to be equivalent to Wiener filtering in its simplest form.; (2) The ALOK i, k-filter. This is a non linear filter mainly used for data reduction purposes during the inspection of large scale components. An attempt is made to at least partly recover the original signal from ALOK data.; (3) Image processing. Using the holographic image of a natural crack we show different image processing techniques. This may be a tool to gain more insight into the flaw size and geometry under test

Orally delivered MK-4482 inhibits SARS-CoV-2 replication in the Syrian hamster model

AbstractThe COVID-19 pandemic progresses unabated in many regions of the world. An effective antiviral against SARS-CoV-2 that could be administered orally for use following high-risk exposure would be of substantial benefit in controlling the COVID-19 pandemic. Herein, we show that MK-4482, an orally administered nucleoside analog, inhibits SARS-CoV-2 replication in the Syrian hamster model. The inhibitory effect of MK-4482 on SARS-CoV-2 replication is observed in animals when the drug is administered either beginning 12 h before or 12 h following infection in a high-risk exposure model. These data support the potential utility of MK-4482 to control SARS-CoV-2 infection in humans following high-risk exposure as well as for treatment of COVID-19 patients.</jats:p

Improving education in primary care: development of an online curriculum using the blended learning model

<p>Abstract</p> <p>Background</p> <p>Standardizing the experiences of medical students in a community preceptorship where clinical sites vary by geography and discipline can be challenging. Computer-assisted learning is prevalent in medical education and can help standardize experiences, but often is not used to its fullest advantage. A blended learning curriculum combining web-based modules with face-to-face learning can ensure students obtain core curricular principles.</p> <p>Methods</p> <p>This course was developed and used at The Case Western Reserve University School of Medicine and its associated preceptorship sites in the greater Cleveland area. Leaders of a two-year elective continuity experience at the Case Western Reserve School of Medicine used adult learning principles to develop four interactive online modules presenting basics of office practice, difficult patient interviews, common primary care diagnoses, and disease prevention. They can be viewed at <url>http://casemed.case.edu/cpcp/curriculum</url>. Students completed surveys rating the content and technical performance of each module and completed a Generalist OSCE exam at the end of the course.</p> <p>Results</p> <p>Participating students rated all aspects of the course highly; particularly those related to charting and direct patient care. Additionally, they scored very well on the Generalist OSCE exam.</p> <p>Conclusion</p> <p>Students found the web-based modules to be valuable and to enhance their clinical learning. The blended learning model is a useful tool in designing web-based curriculum for enhancing the clinical curriculum of medical students.</p

The midgut transcriptome of Phlebotomus (Larroussius) perniciosus, a vector of Leishmania infantum: comparison of sugar fed and blood fed sand flies

<p>Abstract</p> <p>Background</p> <p>Parasite-vector interactions are fundamental in the transmission of vector-borne diseases such as leishmaniasis. <it>Leishmania </it>development in the vector sand fly is confined to the digestive tract, where sand fly midgut molecules interact with the parasites. In this work we sequenced and analyzed two midgut-specific cDNA libraries from sugar fed and blood fed female <it>Phlebotomus perniciosus </it>and compared the transcript expression profiles.</p> <p>Results</p> <p>A total of 4111 high quality sequences were obtained from the two libraries and assembled into 370 contigs and 1085 singletons. Molecules with putative roles in blood meal digestion, peritrophic matrix formation, immunity and response to oxidative stress were identified, including proteins that were not previously reported in sand flies. These molecules were evaluated relative to other published sand fly transcripts. Comparative analysis of the two libraries revealed transcripts differentially expressed in response to blood feeding. Molecules up regulated by blood feeding include a putative peritrophin (<it>PperPer1</it>), two chymotrypsin-like proteins (<it>PperChym1 </it>and <it>PperChym2</it>), a putative trypsin (<it>PperTryp3</it>) and four putative microvillar proteins (<it>PperMVP1</it>, <it>2</it>, <it>4 </it>and <it>5</it>). Additionally, several transcripts were more abundant in the sugar fed midgut, such as two putative trypsins (<it>PperTryp1 </it>and <it>PperTryp2</it>), a chymotrypsin (<it>PperChym3</it>) and a microvillar protein (<it>PperMVP3</it>). We performed a detailed temporal expression profile analysis of the putative trypsin transcripts using qPCR and confirmed the expression of blood-induced and blood-repressed trypsins. Trypsin expression was measured in <it>Leishmania infantum</it>-infected and uninfected sand flies, which identified the <it>L. infantum</it>-induced down regulation of <it>PperTryp3 </it>at 24 hours post-blood meal.</p> <p>Conclusion</p> <p>This midgut tissue-specific transcriptome provides insight into the molecules expressed in the midgut of <it>P. perniciosus</it>, an important vector of visceral leishmaniasis in the Old World. Through the comparative analysis of the libraries we identified molecules differentially expressed during blood meal digestion. Additionally, this study provides a detailed comparison to transcripts of other sand flies. Moreover, our analysis of putative trypsins demonstrated that <it>L. infantum </it>infection can reduce the transcript abundance of trypsin <it>PperTryp3 </it>in the midgut of <it>P. perniciosus</it>.</p

Run-Off Replication of Host-Adaptability Genes Is Associated with Gene Transfer Agents in the Genome of Mouse-Infecting Bartonella grahamii

The genus Bartonella comprises facultative intracellular bacteria adapted to mammals, including previously recognized and emerging human pathogens. We report the 2,341,328 bp genome sequence of Bartonella grahamii, one of the most prevalent Bartonella species in wild rodents. Comparative genomics revealed that rodent-associated Bartonella species have higher copy numbers of genes for putative host-adaptability factors than the related human-specific pathogens. Many of these gene clusters are located in a highly dynamic region of 461 kb. Using hybridization to a microarray designed for the B. grahamii genome, we observed a massive, putatively phage-derived run-off replication of this region. We also identified a novel gene transfer agent, which packages the bacterial genome, with an over-representation of the amplified DNA, in 14 kb pieces. This is the first observation associating the products of run-off replication with a gene transfer agent. Because of the high concentration of gene clusters for host-adaptation proteins in the amplified region, and since the genes encoding the gene transfer agent and the phage origin are well conserved in Bartonella, we hypothesize that these systems are driven by selection. We propose that the coupling of run-off replication with gene transfer agents promotes diversification and rapid spread of host-adaptability factors, facilitating host shifts in Bartonella

A survey of real-time operating systems and virtualization solutions for space systems

The Department of Defense and the intelligence community rely on space systems for a broad spectrum of services. These systems operate in highly constrained environments (in terms of space, weight and power), making virtualization and resource sharing a desirable approach. Agencies are actively exploring new architectures, such as those employing virtualization, to support their growing space mission. In this thesis, we review how virtualization architectures claim to support the real-time requirements of their guests. We survey real-time systems and virtualization architectures proposed for use in space systems. Further, we investigate the behaviors of virtualized operating systems using a method of remote network-based fingerprinting with TCP timestamps. Our work provides insights into how guests, both general purpose and real-time, behave in virtualized environments. Our survey work and experimental analysis aim to further understanding of how virtualization can be securely incorporated into space systems.http://archive.org/details/asurveyofrealtim1094545256Civilian, Department of DefenseApproved for public release; distribution is unlimited

The froth stability column : linking froth stability and flotation performance

Froth structure and stability are known to play important roles in determining mineral flotation recovery and selectivity. However, measuring froth stability quantitatively, both at laboratory and industrial scales remains a significant challenge. A quantitative dynamic stability measure has previously been evaluated at laboratory scale. The technique is based on the Bikerman foam test and uses a non-overflowing froth column to quantify froth stability. At laboratory scale the froth stability measured in this way agreed very closely with other methods, and could be related to flotation performance. In this paper, the froth stability column is tested at Northparkes, Australia. The dynamic froth stability Σ and froth stability factor β were measured under different operating conditions, and compared with the fraction of air overflowing the cell, α, which was measured using image analysis. The froth stability column results gave the same trends as image analysis. In particular the froth stability factor was found to be linearly related to the actual fraction of air overflowing the cell. The metallurgical results clearly indicated that changes in air rate, froth depth and frother concentration result in variation in flotation performance that can be attributed to changes in froth stability. The results showed that high froth stability conditions occur at lower air flowrates, and result in improved flotation performance. It is found that the froth stability column is an accurate and cost-effective method for quantifying froth stability, and for indicating changes in flotation performance

Apparative developments for inservice inspections of reactor pressure vessels

Inservice inspections of primary circuit components are important preventive measures to guarantee nuclear power plant integrity, satisfying simultaneously reactor safety and economy in plant operation. Emphasizing pressurized water reactor pressure vessel (RPV) inspections, recent developments of new generations of automated and mechanized ultrasonic inspection equipment are presented. Starring from general equipment design and inservice implementation criteria, specific examples are given. Main attention is directed to equipment realization of phased array and ALOK inspection techniques, especially in their combination. Refined aspects of subsequent computer processing and evaluation of defect detection data are described. Analytical features and potential for further developments become evident. Remote controlled RPV inspections are stressed by describing a new generation of central mast manipulators, forming an integral part of total inservice inspection system. (IZFP