Boundary Controllability and Observability of a Viscoelastic String

In this paper we consider an integrodifferential system, which governs the vibration of a viscoelastic one-dimensional object. We assume that we can act on the system at the boundary and we prove that it is possible to control both the position and the velocity at every point of the body and at a certain time $T$, large enough. We shall prove this result using moment theory and we shall prove that the solution of this problem leads to identify a Riesz sequence which solves controllability and observability. So, the result as presented here are constructive and can lead to simple numerical algorithms

Autonomic pain responses during sleep: a study of heart rate variability

The autonomic nervous system (ANS) reacts to nociceptive stimulation during sleep, but whether this reaction is contingent to cortical arousal, and whether one of the autonomic arms (sympathetic/parasympathetic) predominates over the other remains unknown. We assessed ANS reactivity to nociceptive stimulation during all sleep stages through heart rate variability, and correlated the results with the presence of cortical arousal measured in concomitant 32-channel EEG. Fourteen healthy volunteers underwent whole-night polysomnography during which nociceptive laser stimuli were applied over the hand. RR intervals (RR) and spectral analysis by wavelet transform were performed to assess parasympathetic (HF(WV)) and sympathetic (LF(WV) and LF(WV)/HF(WV) ratio) reactivity. During all sleep stages, RR significantly decreased in reaction to nociceptive stimulations, reaching a level similar to that of wakefulness, at the 3rd beat post-stimulus and returning to baseline after seven beats. This RR decrease was associated with an increase in sympathetic LF(WV) and LF(WV)/HF(WV) ratio without any parasympathetic HF(WV) change. Albeit RR decrease existed even in the absence of arousals, it was significantly higher when an arousal followed the noxious stimulus. These results suggest that the sympathetic-dependent cardiac activation induced by nociceptive stimuli is modulated by a sleep dependent phenomenon related to cortical activation and not by sleep itself, since it reaches a same intensity whatever the state of vigilance

A Technique of Direct Tension Measurement of a Strung Fine Wire

We present a new technique of direct measurement of wire tensions in wire chambers. A specially designed circuit plucks the wire using the Lorentz force and measures the frequency of damped transverse oscillations of the wire. The technique avoids the usual time-consuming necessity of tuning circuit parameter to a resonance. It allows a fast and convenient determination of tensions and is straightforward to implement.Comment: 15 pages with 9 figure

Enhanced Grazing Management Assessment Using Drone-Based Lidar Measurements

Globally, there is an urgent need of research-based technologies for small ruminant producers to benefit from rapidly growing market demands for ruminant meat and related food products from forage-based operations. However, effective forage-based animal production requires a rapid assessment, and monitoring of grazing management needs to adjust stocking rates and/or spatial animal distribution in a timely manner. Applicability of unmanned aerial vehicles (drones) for grazing management offers opportunities to rapidly estimate biomass build-ups, ground coverage, and monitor animal behaviour. The reliability of drone-based laser scanning (DLS) for monitoring warm-season grass responses to simulated grazing intensities was assessed at Virginia State University. Aerial DLS point-cloud data were collected from pure and mixed native warm-season grass stands at early- and mid-season post-harvest regrowth in early May and June, respectively, along with ground-based estimates of yield and ground cover. Animal behavioural responses to drone activity at different heights were also recorded. The aerial estimates from DLS point cloud characteristics were compared with matching ground-based measurements of forage biomass, sward heights, and ground cover. Discernible correlations between the point cloud-based estimates and actual measurements for forage biomass, ground cover and sward heights were observed. Goats showed no changes in activity due to drone flights at ≥15 m above ground but demonstrated curiosity to drone presence between 10 & 15 m. These preliminary results suggest reliable applicability of DLS for expedited assessment of plant and animal responses to grazing management

A retrospective analysis of 1.011 percutaneous liver biopsies performed in patients with liver transplantation or liver disease: ultrasonography can reduce complications?

Objective: In the last decades, liver biopsy was the reference procedure for the diagnosis and follow-up of liver disease. Aim of present retrospective analysis was to assess the prevalence of complications and risk factors after Percutaneous Liver Biopsy (PLB) performed for diagnosis and staging in patients with chronic liver disease and for monitoring the graft in liver transplanted patients Patients and methods: Data were collected from a total of 1.011 PLB performed with the Menghini technique between January 2004 and December 2014 at the Hepatology and Transplant Units of the University of Rome Tor Vergata. The indications for biopsy were: follow-up of liver transplantation, chronic Hepatitis B Virus (HBV) or Hepatitis C Virus (HCV), with or without Human Immunodeficiency Virus (HIV) and alcohol-related liver disease. Our patients were divided into two groups according to the biopsy indication: follow-up of liver transplantation (Group A) and chronic liver disease (Group B). All the procedures were performed in Day Hospital regimen. After the biopsy, patients remained in bed for about 4-6 hours. In the absence of complications, they were then discharged on the same day. Results: The most frequent complication after biopsy was pain (Group A n. 57, 8.8%; Group B n. 105, 29.0%), hypotension as a result of a vasovagal reaction resolved spontaneously (Group A n. 7, 1.1%; Group B n. 6, 1.7%), and intrahepatic bleeding resolved with conservative therapy (Group A n. 1, 0.2%; Group B n. 6, 1.7%). Two cases of pneumothorax in the Group A (0.3%) were treated with a chest tube. Other complications did not have a significant impact. Also, we did not observe statistically significant differences in patients who underwent PLB without and with ultrasound guidance. Conclusions: Liver biopsy is not a replaceable tool in diagnosis and follow-up of several chronic liver diseases. The Menghini technique with the percutaneous trans costal approach, might be preferred because less traumatic and related with a low occurrence of minor and major complications. According to our case load and comparing our findings with the previous published data, we speculate that ultrasound guidance is not crucial in the prevention of major complications

Splenic Flexure Volvulus Presenting with Peritonitis: Case Report and Review of the Literature

Splenic flexure is the rarest site for colonic volvulus. We report a case of an 18 years old woman, admitted to our department for tender and sore abdomen, nausea and vomiting. A barium enema reported a splenic flexure volvulus. Explorative laparotomy revealed peritonitis originating from an extensive gangrene of splenic flexure of the colon, caused by 360° volvulus. The colon was encircled by omentum at its base. A resection with primary anastomosis was performed. Anatomic abnormalities and partial intestinal malrotation are the main pathogenetic cause

The face of Glut1-DS patients : A 3D craniofacial morphometric analysis

Introduction - Glut1 deficiency syndrome (Glut1-DS) is a neurological and metabolic disorder caused by impaired transport of glucose across the blood brain barrier (BBB). Mutations on the SCL2A1 gene encoding the glucose transporter protein in the BBB cause the syndrome, which encompasses epilepsy, movement disorders and mental delay. Such variability of symptoms presents an obstacle to early diagnosis. The patients seem to share some craniofacial features, and identification and quantification of these could help in prompt diagnosis and clinical management. Materials and method - We performed a three-dimensional morphometric analysis of the faces of 11 female Glut1-DS patients using a stereophotogrammetric system. Data were analyzed using both inter-landmark distances and Principal Component Analysis (PCA). Results - Compared to data collected from age-, sex- and ethnicity-matched control subjects, common and homogenous facial features were identified among patients, which were mainly located in the mandible and the eyes. Glut1-DS patients had a more anterior chin; their mandibular body was longer but the rami were shorter, with a reduced gonial angle; they had smaller and down-slanted eyes with a reduced intercanthal distance. Conclusions - This study highlights the importance of morphometric analysis for defining the facial anatomical characteristics of the syndrome better, potentially helping clinicians to diagnose Glut1-DS. Imnproved knowledge of the facial anatomy of these patients can provide insights into their facial and cerebral embryological development, perhaps further clarifying the molecular basis of the syndrome

Automated border control systems: biometric challenges and research trends

Automated Border Control (ABC) systems automatically verify the travelers\u2019 identity using their biometric information, without the need of a manual check, by comparing the data stored in the electronic document (e.g., the e-Passport) with a live sample captured during the crossing of the border. In this paper, the hardware and software components of the biometric systems used in ABC systems are described, along with the latest challenges and research trends

Unexpected one-pot synthesis of highly conjugated pentacyclic diquinoid compounds

A new class of pentacyclic diquinoid compounds has been synthesized with a facile one-pot reaction of two molecules of 2-hydroxynaphthoquinone and 1-bromoalkanes in the presence of ferrocene. These molecules were isolated as enol tautomers that exhibit intramolecular hydrogen bond and extended electronic conjugation as proved by the intense absorption spectrum with a broad band between 400 and 600 nm. The spectroscopic and electrochemical characterization of this new class of compounds has been performed. One of the synthesized diquinoid derivatives showed a significant cytotoxicity with IC50 values of 25−50 μM against Cisplatin-Resistant SKOV3 and colon carcinoma SW480 cell lines. The results of our study provide a valuable tool to a one-pot synthesis of highly conjugated polyquinones, analogous to important biological systems, with significant antitumoral activity

Measurement of Dielectric Suppression of Bremsstrahlung

In 1953, Ter-Mikaelian predicted that the bremsstrahlung of low energy photons in a medium is suppressed because of interactions between the produced photon and the electrons in the medium. This suppression occurs because the emission takes place over on a long distance scale, allowing for destructive interference between different instantaneous photon emission amplitudes. We present here measurements of bremsstrahlung cross sections of 200 keV to 20 MeV photons produced by 8 and 25 GeV electrons in carbon and gold targets. Our data shows that dielectric suppression occurs at the predicted level, reducing the cross section up to 75 percent in our data.Comment: 11 pages, format is postscript file, gzip-ed, uuencode-e