A comparison of high-latitude ionospheric propagation predictions from Advanced Prophet 4.0 with measured data

Progress in computers during the past two decades has sparked the development of many useful high frequency (HF) ionospheric propagation prediction codes. The high-latitude (polar) ionosphere still remains as the most difficult propagation region to predict. A 'Non centric database of collected high-latitude signal and noise measurements was obtained during 1988 and 1989 by the University of Leicester, UK The Advanced Prophet 4.0 HF Ionospheric Propagation Prediction Code was exercised and compared to a portion of the 'Non centric database, for a transmitter at Clyde River, Canada and a receiver at Leicester, U.K. The Prophet predictions were better during winter months than during summer months. Overall, 70% of the signal strength data from Prophet 4.0 were between -20 dB and +20 dB error, compared to the measured data.http://archive.org/details/acomparisonofhig1094527587Lieutenant, Hellenic NavyApproved for public release; distribution is unlimited

Degradation and by-products identification of benzothiazoles and benzotriazoles during chlorination by LC-HR-MS/MS

Nowadays, chlorination is the most prevalent disinfection method applied for water treatment in Europe. Chlorine can be supplied as sodium hypochlorite (NaOCl) which reacts in water to produce the disinfectants hypochlorous acid (HOCl) and hypochlorite ion (OCl-), otherwise known as free chlorine. Although the primary purpose of chlorination is the elimination of micropollutants via oxidation, several investigations have shown that chlorine reacts with micropollutants leading in the production of undesired by-products. 1,3-benzothiazoles (BTHs) and 1,2,3-benzotriazoles (BTRs) are classified as high production volume emerging environmental pollutants due to their broad industrial and domestic application, and even though recently several analytical methods have been applied for their determination , there is still a lack of research for their by-products’ identification. Initially, the degradation of three BTHs (BTH, 2-OH-BTH and 2-amino-BTH) and four BTRs (1-H-BTRi, TTRi, XTRi and 1-OH-BTRi) during chlorination was investigated by UHPLC-MS/MS (QqQ). Although chlorination appeared to be an insufficient degradation process for BTH and 1-H-BTRi, all their examined substituted derivatives seem to be significantly degraded when the molar ratio of sodium hypochlorite and the target analytes was between 5000:1 – 1000:1. Then, LC high resolution MS/MS (q-TOFMS) was used to investigate the formation of by-products in the chlorinated samples. Two suspect by-products of 2-amino-BTH and one of XTRi were tentatively identified based on their probable structure, mass accuracy, retention time and fragmentation and isotopic pattern. An interesting observation was the formation of 1-H-BTRi as a degradation product of 1-OH-BTRi during chlorination. Moreover, post-acquisition non-target treatment of the MS data revealed several unknown by-products of the tested analytes

Host and Distribution Lists of Chiggers (Trombiculidae and Leeuwenhoekiidae), of North American Wild Vertebrates North of Mexico

Information concerning chiggers found on wild vertebrates of North America north of Mexico is summarized. Included are lists a) of the chiggers organized taxonomically, b) hosts from which each species has been reported, and c) states and provinces with references for each separate recor

Pandrug-resistant Gram-negative bacteria : a systematic review of current epidemiology, prognosis and treatment options

Background: The literature on the epidemiology, mortality and treatment of pandrug-resistant (PDR) Gram-negative bacteria (GNB) is scarce, scattered and controversial. Objective: To consolidate the relevant literature and identify treatment options for PDR GNB infections. Methods: A systematic search in MEDLINE, Scopus and clinical trial registries was conducted. Studies reporting PDR clinical isolates were eligible for review if susceptibility testing for all major antimicrobials had been performed. Characteristics and findings of retrieved studies were qualitatively synthesized. Results: Of 81 studies reviewed, 47 (58%) were published in the last 5 years. The reports reflected a worldwide dissemination of PDR GNB in 25 countries in 5 continents. Of 526 PDR isolates reported, Pseudomonas aeruginosa (n=175), Acinetobacter baumannii (n=172) and Klebsiella pneumoniae (n=125) were most common. PDR GNB were typically isolated in intensive care units, but several studies demonstrated wider outbreak potential, including dissemination to long-term care facilities and international spread. All-cause mortality was high (range, 20%-71%), but appeared to be substantially reduced in studies reporting treatment regimens active in vitro. No controlled trial has been performed to date, but several case reports and series noted successful use of various regimens, predominantly synergistic combinations, and in selected patients increased exposure regimens and newer antibiotics. Conclusion: PDR GNB are increasingly being reported worldwide and are associated with high mortality. Several treatment regimens have been successfully used, of which synergistic combinations appear to be most promising and often the only available option. More pharmacokinetic/pharmacodynamic and outcome studies are needed to guide the use of synergistic combinations

Osteomimetic matrix components alter cell migration and drug response in a 3D tumour-engineered osteosarcoma model

vulnerable to recurring disease and pulmonary metastases. Developing 3D in vitro disease models to serve as a test bed for personalised treatment is a promising approach to address this issue. This study describes the generation of 3D osteosarcoma models termed “tumouroids”, which are geometrically compartmentalised to reproduce the bone cancer mass and its surrounding. Although the tumour microenvironment impacts osteosarcoma in many ways, this model focussed on interrogating the influence of a biomimetic matrix on tumour cell behaviour. The 3D matrix was supplemented with the bone-marrow proteins laminin, fibronectin and NuOss® bone granules. This led to increased invasion of osteosarcoma cell aggregates from within the bone-like matrix into the surrounding acellular bone marrow-like ECM. The presence of bone granules also yielded an atypical molecular profile of osteosarcoma cells, suggesting malignant metabolic reprogramming. Changes include decreased MMP-9 (p < 0.05) and increased PTEN (p < 0.05), MCP-1 (p < 0.01) and MCT-4 (p < 0.05) gene expression. This complex 3D biomimetic composition also changed cellular responses to doxorubicin, a common chemotherapeutic agent used to treat osteosarcoma, and reproduced key issues of in vivo treatment like drug penetrance and doxorubicin-induced bone toxicity. This work highlights the importance of a biomimetic matrix in 3D osteosarcoma models for both basic and translational research

Post-radiation sciatic neuropathy: a case report and review of the literature

<p>Abstract</p> <p>Background</p> <p>Post-radiation peripheral neuropathy has been reported in brachial and cervical plexuses and the femoral nerve.</p> <p>Case presentation</p> <p>We describe a patient who developed post-radiation sciatic neuropathy after approximately 3 years and discuss the pathophysiology, clinical course and treatment options available for the deleterious effects of radiation to peripheral nerves.</p> <p>Conclusion</p> <p>This is the first case of post-radiation involvement of the sciatic nerve reported in the literature.</p

The role of diet and lifestyle in women with breast cancer: An update review of related research in the Middle East

© Zainab Taha and Sakina E. Eltom 2018. Breast cancer is the most common malignancy among Arab women in Eastern Mediterranean Region (EMR). The incidence of breast cancer has substantially increased in recent years among this women population, especially those younger than 50, and the incidence is expected to double by 2030. Considerable experimental evidence supports the potential role of dietary habits and lifestyle in cancer etiology and cancer prevention. In this review we examined the literature for evidence to link dietary choices and the rise in incidence and mortality of breast cancer among women in EMR. A literature search was conducted in PubMed and Ovid MEDLINE databases up to December 2017. The search terms used are breast cancer prevalence, breast cancer incidence worldwide, breast cancer and: nutrition, protein intake, Vitamin D intake, fat intake, phytoestrogens, EMR, Arab, Middle East, Gulf countries, the UAE Arab women, breast cancer risk, diet, and chemoprevention. We found evidence to suggest that there is an alarming epidemic of obesity among women in most of the EMR countries, especially Gulf Cooperation Council (GCC) countries. The rise in the new breast cancer cases among women could be attributed to excess body weight. Their dietary pattern, which correlates with obesity, can be an important factor in the etiology of cancer. Although very few studies were found to support a direct causal relationship between obesity and breast cancer in the EMR, circumstantial evidence clearly points to the possible role of the epidemic, obesity, in this population and the startling rise in cases of breast cancer. Well-designed and systematic studies are urgently needed to confirm these associations and to elucidate potential mechanisms. More urgently, calls to action are needed in many sectors and at all levels of society, to establish intensive strategies for reducing obesity and promoting an overall healthy diet. Continued and expanded research on diet, lifestyle, and breast cancer risk is urgently needed to build the foundation for future progress in evidence-based public health efforts

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