Improved Direction of Arrival Estimation using Multiple Signal Classification (MUSIC) Algorithm with Decomposition and Normalization

It is important to determine the direction of arrival (DoA) of targets in various applications such as radar and sonar. Multiple Signal Classification (MUSIC), Estimation of Signal Parameters with Rotational In variance Technique (ESPRIT), and Weighted Subspace Fitting (WSF) are subspace-based methods that can be used to improve DoA estimation. MUSIC is effective for high-resolution, uncorrelated signals, but may struggle in cases where there are two nearby targets with a low signal-to-noise ratio (SNR). The goal of this research is to improve the performance of the MUSIC algorithm for DoA estimation with low SNR signals. The proposed solution involves decomposing and normalizing the signal during transmission. Simulations were conducted to test the modified procedure with MUSIC algorithm for DoA estimation, and it was found that received signal power improved though there is noisy environment as well as system can detect more number of targets. The proposed technique of decomposition and normalization could also be applied in other areas such as WiFi communication, autonomous vehicles and biomedical signal and image processing etc

Balloon observations of hard X-rays from NGC 4151 and an X-ray transient source

An X-ray telescope consisting of 400 sq cm phoswich detectors (NaI(Tl)/CsI(Na)) was flown from Hyderabad (India) on 31 October 1980; the field of view was 11 deg x 1 deg FWHM. During a five hour observation at 5 millibars two X-ray sources were seen: (1) the variable Seyfert Galaxy NGC 4151; and (2) a transident of approximately 8 minutes duration in the vicinity of the variable source 4U1444 43 which may be associated with the galaxy NGC 5608. X-ray fluxes and spectra in 18-120 keV X-rays are presented

Balloon observations of hard X-rays from some galactic X-ray sources

An X-ray telescope consisting of 400 cm phoswich detectors (NaI(T1)/CsI(Na)) was flown from Hyderabad (India) on 18 December 1984. The field of view was 5 deg x 5 deg FWHM. In a 10 hour float at 4 MB several galactic X-ray sources were tracked by the telescope using an on-board microprocessor. Fluxes and spectra in 18-120 keV X-rays for SCO X-1, GX 1+4, Gx 5-1, GX 17+2, SCT X-1, CYC X-1 an CYG X-3 will be presented

Ectoine can enhance structural changes in DNA in vitro

Strand breaks and conformational changes of DNA have consequences for the physiological role of DNA. The natural protecting molecule ectoine is beneficial to entire bacterial cells and biomolecules such as proteins by mitigating detrimental effects of environmental stresses. It was postulated that ectoine-like molecules bind to negatively charged spheres that mimic DNA surfaces. We investigated the effect of ectoine on DNA and whether ectoine is able to protect DNA from damages caused by ultraviolet radiation (UV-A). In order to determine different isoforms of DNA, agarose gel electrophoresis and atomic force microscopy experiments were carried out with plasmid pUC19 DNA. Our quantitative results revealed that a prolonged incubation of DNA with ectoine leads to an increase in transitions from supercoiled (undamaged) to open circular (single-strand break) conformation at pH 6.6. The effect is pH dependent and no significant changes were observed at physiological pH of 7.5. After UV-A irradiation in ectoine solution, changes in DNA conformation were even more pronounced and this effect was pH dependent. We hypothesize that ectoine is attracted to the negatively charge surface of DNA at lower pH and therefore fails to act as a stabilizing agent for DNA in our in vitro experiments

Personal preference, experience, intuition and school of surgery dominate the use of wound drainage in dermatosurgery

Hintergrund Die Verwendung von Drainagesystemen in der Dermatochirurgie erfolgt bislang ohne evidenzbasierte Daten. Indikationen, Komplikationen und Kontraindikationen werden traditionell von Operateur zu Operateur weitergegeben, sind jedoch bisher nicht definiert. Methodik Es wurde eine internetbasierte Umfrage erstellt und unter den Mitgliedern der DGDC e. V. (Deutsche Gesellschaft für Dermatochirurgie e. V.) ausgesandt. Abgefragt wurden das allgemeine Behandlungsverhalten im deutschsprachigen Raum in Bezug auf die Anwendung der Wunddrainage nach dermatologischen Operationen sowie die Nutzungsgewohnheiten und Erfahrungen der Kollegen mit Drainage-assoziierten Komplikationen. Ergebnisse Es haben 12,73 % der angeschriebenen DGDC-Mitglieder den Fragebogen beantwortet. Drainagen werden überwiegend im klinischen Umfeld eingesetzt, es werden alle abgefragten Drainagesysteme verwendet. Ausmaß und Komplexität des Eingriffs sind die wesentlichen Kriterien bei der Indikationsstellung. Der Einsatz von Drainagen ist abhängig vom Alter des Teilnehmers und erfolgt mehrheitlich bei Patienten, bei denen Komplikationen im postoperativen Verlauf erwartet werden (Adipositas, Nikotinabusus, Diabetiker). Diskussion Zusammenfassend verwendet die Mehrzahl der Teilnehmer Wunddrainagen und dies mehrheitlich intuitiv. Einheitliche fixe evidenzbasierte Parameter rund um die Verwendung von Wunddrainagen fehlen. Bei der Beurteilung der Notwendigkeit einer Wunddrainage scheint ein individuell unterschiedlich ausgeprägtes Sicherheitsbedürfnis bei den einen und „eminenzbasiertes“ Handeln bei den anderen Dermatochirurgen eine große Rolle zu spielen.Background The use of drainage systems in dermatosurgery has so far been carried out without evidence-based data. The indications, complications and contraindications are traditionally passed on from surgeon to surgeon but have so far not been defined. Method An Internet-based survey was created and sent out to members of the German Society for Dermatosurgery (DGDC). The questions were on the general treatment approach in German language countries with reference to the use of wound drainage following dermatological operations as well as the utilization habits and experiences with drainage-associated complications. Results Of the DGDC members contacted 12.73% completed the questionnaire. Drainages were predominantly used in the clinical environment and all drainage systems in question were used. The extent and complexity of the intervention were essential criteria when evaluating the indications. The use of drainages was dependent on the age of the participant and mostly carried out in patients where complications in the postoperative course were to be expected (e.g. obesity, nicotine use, diabetes). Conclusion In summary, the majority of the participants used wound drainages and mostly intuitively. Uniform and fixed evidence-based parameters for the use of wound drainages are lacking. In the assessment of the necessity for a wound drainage, an individually expressed need of safety seems to play a large role for some dermatosurgeons and an eminence-based action for others

Assessment of MMP-9, TIMP-1, and COX-2 in normal tissue and in advanced symptomatic and asymptomatic carotid plaques

<p>Abstract</p> <p>Background</p> <p>Mature carotid plaques are complex structures, and their histological classification is challenging. The carotid plaques of asymptomatic and symptomatic patients could exhibit identical histological components.</p> <p>Objectives</p> <p>To investigate whether matrix metalloproteinase 9 (MMP-9), tissue inhibitor of MMP (TIMP), and cyclooxygenase-2 (COX-2) have different expression levels in advanced symptomatic carotid plaques, asymptomatic carotid plaques, and normal tissue.</p> <p>Methods</p> <p>Thirty patients admitted for carotid endarterectomy were selected. Each patient was assigned preoperatively to one of two groups: group I consisted of symptomatic patients (n = 16, 12 males, mean age 66.7 ± 6.8 years), and group II consisted of asymptomatic patients (n = 14, 8 males, mean age 67.6 ± 6.81 years). Nine normal carotid arteries were used as control. Tissue specimens were analyzed for fibromuscular, lipid and calcium contents. The expressions of MMP-9, TIMP-1 and COX-2 in each plaque were quantified.</p> <p>Results</p> <p>Fifty-eight percent of all carotid plaques were classified as Type VI according to the American Heart Association Committee on Vascular Lesions. The control carotid arteries all were classified as Type III. The median percentage of fibromuscular tissue was significantly greater in group II compared to group I (<it>p </it>< 0.05). The median percentage of lipid tissue had a tendency to be greater in group I than in group II (<it>p </it>= 0.057). The percentages of calcification were similar among the two groups. MMP-9 protein expression levels were significantly higher in group II and in the control group when compared with group I (p < 0.001). TIMP-1 expression levels were significantly higher in the control group and in group II when compared to group I, with statistical difference between control group and group I (p = 0.010). COX-2 expression levels did not differ among groups. There was no statistical correlation between MMP-9, COX-2, and TIMP-1 levels and fibrous tissue.</p> <p>Conclusions</p> <p>MMP-9 and TIMP-1 are present in all stages of atherosclerotic plaque progression, from normal tissue to advanced lesions. When sections of a plaque are analyzed without preselection, MMP-9 concentration is higher in normal tissues and asymptomatic surgical specimens than in symptomatic specimens, and TIMP-1 concentration is higher in normal tissue than in symptomatic specimens.</p

Transformation around intruders in granular media

Sintering, glass melting and other industrially relevant processes turn batches of grains into homogeneous products. Such processes involve coupled chemical and physical transformations of the granular packing. For sake of simplicity, we study how local evolutions on grains (volume decreases for example) entail mechanical rearrangements in the overall pile. Inert bidisperse metallic disks are mixed and confined in a vertical 2D cell. At the bottom of this set-up, initial intruders (one or two) have been previously set and mechanically linked to a linear motorized jack. While we quasi-statically pull the intruder(s) downward out of the cell at constant speed and constant liberated surface, we tracked the surrounding granular packing. Events largely distributed both spatially and temporally occur around intruders. We focus on the influence of the distance between the intruders on the local dynamic of the packing. We compare the distribution of the size of the event and their frequency as function of the relative position of the intruder, as a function of their radius. We show that their influence decreases rapidly. At short distance the mechanical perturbation induced by one intruder can destabilize the packing around the other