Investigating the ability of high-rate GNSS-PPP for determining the vibration modes of engineering structures: small scale model experiment

This study evaluates the performance of the Precise Point Positioning method using Global Navigation Satellite System measurements (GNSS-PPP) for monitoring vibration modes of shear type buildings excited by harmonic ground motions and hammer tests. For experimental testing, the shear type lumped-mass building system is represented by a specially designed metal frame model, resembling a three story building, which was excited on a small scale shaking table. The excitation protocols applied were harmonic motions with different frequencies and amplitudes. The metal model has special deformation plates at the column tips to prevent the nonlinear rotations and out-of-plane motions for the entire system. The fundamental vibration periods of the model structure were computed by a Finite Element Mathematical (FEM) model, which were compared with the position variations determined by GNSS-PPP. Two GNSS receivers were mounted on top of the model structure on the line perpendicular to the motion axis to measure the rotation motion. The GNSS data comprised dual-frequency observations with a 10 Hz sampling rate. GNSS-derived positioning was obtained by processing the data using a post-mission kinematic PPP method with fixed phase ambiguities. Analysis of the characteristics of the vibration frequencies showed that the high-rate GNSS PPP method can capture the frequencies of first motion mode of shear type structural response when compared with the FEM output. Results demonstrate the efficiency of the high-rate GNSS PPP method in monitoring first motion mode of a natural frequency

A MULTI-SCALE CURVE MATCHING TECHNIQUE FOR THE ASSESSMENT OF ROAD ALIGNMENTS USING GPS/INS DATA

ABSTRACT: In this paper a methodology and an algorithm is presented for the automated extraction of road alignments using GPS/INS navigational data. Centerline geometry assessment is derived in the form of traditional design elements. The core of the proposed algorithm relies on the use of multi-scale correlation analysis (similarity and affinity transformations) and fundamental curve matching techniques that were suitably adapted to adhere the nature of road alignment data. A mobile mapping vehicle comprising a high accuracy multi-sensor navigational system was used to verify the correctness and level of automation of the algorithm as well as the feasibility of the associated software

Expansion of KPC-producing klebsiella pneumoniae with various mgrB-mutations giving rise to colistin-resistance:the role of ISL3 on plasmids

BACKGROUND: mcr-1 has been reported as first plasmid gene to confer colistin-resistance. In KPC-producing Klebsiella pneumoniae (KPC-KP) isolates, however, colistin resistance is rapidly emerging through other mechanisms. This is frequently the result of disruption of mgrB gene by insertion sequences, for instance ISL3. The aim of this study is to investigate the expansion of mgrB-mutated KPC-KP. In addition, we identify localization and targets of ISL3 sequences within the core and accessory genome of common KPC-KP lineages. METHODS: Twenty-nine clinical isolates of K. pneumoniae collected from Italian patients were randomly selected. Whole genome sequences (WGS) were analysed for resistance genes, plasmids, and insertion sequences. Additionally, 27 colistin-resistant KPC-KP isolates from a previous study from Crete was assessed. FINDINGS: We observed clonal expansion of KPC-KP isolates with various mutations in mgrB among all lineages. In two Italian MLST ST512 isolates, and eight Greek ST258 isolates an identical copy of the ISL3 was inserted in mgrB nucleotide position 133. ISL3s, transposable restriction modification systems of 8154 nucleotides, were positioned on pKpQIL carrying isolates and may transpose into the chromosome. In 4 isolates, chromosomal integration of ISL3 in diverse inner-membrane proteins other than mgrB was identified. INTERPRETATION: Colistin resistance is most often explained by clonal expansion of isolates with mutated mgrB. pKpQIL-like plasmids, which are omnipresent in KPC-KP, carry insertion sequences such as ISL3 that have mgrB as a target hotspot for transposition. Transposition of insertion sequences from plasmids and subsequent clonal expansion may contribute to the emerging colistin resistance in KPC-KP

A Comparison Between Uwb and Laser-based Pedestrian Tracking

Despite the availability of GNSS on consumer devices enabled personal navigation for most of the World population in most of the outdoor conditions, the problem of precise pedestrian positioning is still quite challenging when indoors or, more in general, in GNSS-challenging working conditions. Furthermore, the covid-19 pandemic also raised of pedestrian tracking, in any environment, but in particular indoors, where GNSS typically does not ensure sufficient accuracy for checking people distance. Motivated by the mentioned needs, this paper investigates the potential of UWB and LiDAR for pedestrian positioning and tracking. The two methods are compared in an outdoor case study, nevertheless, both are usable indoors as well. The obtained results show that the positioning performance of the LiDAR-based approach overcomes the UWB one, when the pedestrians are not obstructed by other objects in the LiDAR view. Nevertheless, the presence of obstructions causes gaps in the LiDAR-based tracking: instead, the combination of LiDAR and UWB can be used in order to reduce outages in the LiDAR-based solution, whereas the latter, when available, usually improves the UWB-based results.Peer reviewe

Experimental evaluation of a UWB-based cooperative positioning system for pedestrians in GNSS-denied environment

Cooperative positioning (CP) utilises information sharing among multiple nodes to enable positioning in Global Navigation Satellite System (GNSS)-denied environments. This paper reports the performance of a CP system for pedestrians using Ultra-Wide Band (UWB) technology in GNSS-denied environments. This data set was collected as part of a benchmarking measurement campaign carried out at the Ohio State University in October 2017. Pedestrians were equipped with a variety of sensors, including two different UWB systems, on a specially designed helmet serving as a mobile multi-sensor platform for CP. Different users were walking in stop-and-go mode along trajectories with predefined checkpoints and under various challenging environments. In the developed CP network, both Peer-to-Infrastructure (P2I) and Peer-to-Peer (P2P) measurements are used for positioning of the pedestrians. It is realised that the proposed system can achieve decimetre-level accuracies (on average, around 20 cm) in the complete absence of GNSS signals, provided that the measurements from infrastructure nodes are available and the network geometry is good. In the absence of these good conditions, the results show that the average accuracy degrades to meter level. Further, it is experimentally demonstrated that inclusion of P2P cooperative range observations further enhances the positioning accuracy and, in extreme cases when only one infrastructure measurement is available, P2P CP may reduce positioning errors by up to 95%. The complete test setup, the methodology for development, and data collection are discussed in this paper. In the next version of this system, additional observations such as the Wi-Fi, camera, and other signals of opportunity will be included

Carcinosarcoma of bladder Evaluation by electron microscopy and immunohistochemistry

A case of carcinosarcoma of the urinary bladder characterized by electron microscopy and immunohistochemistry is described. The use of these studies in poorly differentiated bladder neoplasms and in suspected cases of carcinosarcoma is encouraged. Increased accuracy in characterizing these tumors will permit a better understanding of their natural history and response to therapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24686/1/0000105.pd

Acute ST-segment elevation myocardial infarction after amoxycillin-induced anaphylactic shock in a young adult with normal coronary arteries: a case report

BACKGROUND: Acute myocardial infarction (MI) following anaphylaxis is rare, especially in subjects with normal coronary arteries. The exact pathogenetic mechanism of MI in anaphylaxis remains unclear. CASE PRESENTATION: The case of a 32-year-old asthmatic male with systemic anaphylaxis, due to oral intake of 500 mg amoxycillin, complicated by acute ST-elevation MI is the subject of this report. Following admission to the local Health Center and almost simultaneously with the second dose of subcutaneous epinephrine (0.2 mg), the patient developed acute myocardial injury. Coronary arteriography, performed before discharge, showed no evidence of obstructive coronary artery disease. In vivo allergological evaluation disclosed strong sensitivity to amoxycillin and the minor (allergenic) determinants of penicillin. CONCLUSION: Acute ST-elevation MI is a rare but potential complication of anaphylactic reactions, even in young adults with normal coronary arteries. Coronary artery spasm appears to be the main causative mechanism of MI in the setting of "cardiac anaphylaxis". However, on top of the vasoactive reaction, a thrombotic occlusion, induced by mast cell-derived mediators and facilitated by prolonged hypotension, cannot be excluded as a possible contributory factor

Unfitting, uncomfortable, unacademic: a sociological reading of an interactive mobile phone app in university lectures

Abstract Scholarly literature on education technology uptake has been dominated by technological determinist readings of students’ technology use. However, in recent years there has been a move by sociologists of education to highlight how the contexts in which educational technologies are introduced are not tabula rasa but socially and culturally complex. This study approaches technology as a social construct, arguing that students construct discursive meaning of, rather than simply respond to, technologies for learning. The study explores students’ constructions of a mobile learning app that was introduced into lectures during a year-long university course. Students largely rejected the app, constructing it as unfitting for the context, a socially uncomfortable experience and an unacademic way of learning. The paper highlights the limitations of technological determinism and closes by arguing for readings of educational technologies that pay close attention to students’ voices

Prevalence, and associated risk factors, of self-reported diabetes mellitus in a sample of adult urban population in Greece: MEDICAL Exit Poll Research in Salamis (MEDICAL EXPRESS 2002)

BACKGROUND: The continuous monitoring and future prediction of the growing epidemic of diabetes mellitus worldwide presuppose consistent information about the extent of the problem. The aim of this study was to determine the prevalence of diagnosed diabetes and to identify associated risk factors in a sample of adult urban Greek population. METHODS: A cross-sectional population-based survey was conducted in municipality of Salamis, Greece, during an election day (2002). The study sample consisted of 2805 participants, aged 20–94 years. Data were collected using a standardized short questionnaire that was completed by a face-to-face interview. Multiple regression analyses were performed to evaluate the association of diabetes with potential risk factors. RESULTS: The overall prevalence of diagnosed diabetes was 8.7% (95% CI 7.7–9.8%). After age adjustment for the current adult population (2001 census) of Greece, the projection prevalence was calculated to 8.2%. Multivariate logistic regression analysis identified as independent risk factors: increasing age (odds ratio, OR = 1.07, 95% CI 1.06–1.08), male sex (OR = 1.43, 95% CI 1.04–1.95), overweight and obesity (OR = 1.97, 95% CI 1.29–3.01 and OR = 3.76, 95% CI 2.41–5.86, respectively), family history of diabetes (OR = 6.91, 95% CI 5.11–9.34), hypertension (OR = 2.19, 95% CI 1.60–2.99) and, among women, lower educational level (OR = 2.62, 95% CI 1.22–5.63). The prevalence of overweight and obesity, based on self-reported BMI, were 44.2% and 18.4%, respectively. Moreover, the odds for diabetes in obese subjects with family history were 25-fold higher than those with normal weight and without family history of diabetes, while the odds in overweight subjects with family history of diabetes were 15-fold higher. CONCLUSIONS: Our findings indicated that the prevalence of diabetes is high in Greek population. It is suggested that the main modifiable contributing factor is obesity, whose effect is extremely increased upon positive heredity presence