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Space-air-ground integrated (SAGI) communication networks have been envisioned as one of the pillars of the next generation communications (6 G). This type of networks are expected to offer fairness and high quality of services in various scenarios where traditional terrestrial communication systems cannot efficiently support due to inherent limitations, e.g., limited coverage areas. In this paper, a distributed transmission scheme is proposed in a SAGI communication network that utilizes free-space-optical (FSO)/radio frequency (RF) links. More specifically, a set of N high altitude platform systems are cooperatively transmit the received signal to the ground station, using the decode-and-forward relaying protocol. For this system, generic analytical expressions for the outage probability (OP) have been derived that take into consideration the impact of turbulence, pointing errors, and atmospheric attenuation (for the FSO links) as well as the impact of composite fading (for the RF links). Moreover, asymptotic closed-form expressions for the OP are also presented, which are used to extract useful insights for the system under consideration. The numerical evaluated results that are illustrated reveal the impact of various system and channel models parameters on the system's performance. From these results, it is shown that the proposed scheme outperforms a pure FSO-based relaying scheme, which has been used as a benchmark, under different environmental conditions. [ABSTRACT FROM AUTHOR]

We focus on the rate-optimal design of Wireless Powered Relay Networks (WPRNs) and propose a new cooperative communication scheme. Our scheme employs multiple wireless powered Amplify and Forward (AF) relays and relay selection and combines Time Splitting (TS), with Antenna Switching (AS) and Self Energy Recycling (SER). It consists of an initial Wireless Power Transfer (WPT) subframe, followed by a cooperative transmission subframe, during which one antenna is used for Energy Harvesting (EH) and SER and the remaining ones are used for data reception and data forwarding. For this scheme, we present solutions to the problems of 1) rate-optimal beamforming (BF) design, 2) rate-optimal, joint Harvesting Antenna Selection (HAS), BF design, and WPT subframe duration determination. Our solutions build on a generic piecewise linear EH model, which allows us to closely approximate the characteristics of different non linear EH measurements and models, by selecting the number of piecewise linear components and their parameters. In addition, we consider a realistic power consumption model at the relays that accounts for both transmit and circuit power consumption. Moreover, our BF solution is optimal and requires solving a set of simple optimization problems, where the solution of each one of them can be found in a simple closed form. Thus, it is characterized by low implementation complexity, and avoids sophisticated iterative optimization methods. To the best of our knowledge, this work is the first one to introduce a scheme, which combines TS, AS, and SER principles and exploits realistic EH and power consumption models at the relays. Finally, we assess the performance of our scheme over fading channels and find that it outperforms existing solutions that use the same hardware. [ABSTRACT FROM AUTHOR]

In this paper, stochastic geometry tools are utilized to analyze the performance of a wireless network with Unmanned Aerial Vehicles (UAVs). The evaluation is based on the concept of a truncated octahedron that is the fundamental three-dimensional (3D) shape that models the basic cell in an entirely aerial cellular structure with UAV nodes only. The spatial locations of the aerial users, are modeled as a 3D Binomial Point Process (BPP). Subsequently, stochastic geometry analysis in a reference truncated octahedron located at the origin is performed and exact expressions for the distances between aerial users, are derived. To this end, expressions for evaluating the volume of the regions of the 3D cell in which an aerial user may fall, are derived. Then, by defining the signal-to-interference-plus-noise (SINR) ratio at the reference UAV-base station (UAV-BS) receiver, a performance analysis in terms of coverage probability is conducted under two interference scenarios, i.e., a pure intra-cell interference and an intra- plus inter-cell interference case. As intermediate step in the coverage probability analysis, expressions for relevant distance distributions and the Laplace transform of the aggregate interference power distribution are derived. For the sake of completeness, coverage probability analysis under intra-cell interference is also performed and compared to a 3D cell modeled as a sphere. The analytical expressions are also compared to simulation results to validate the accuracy of the proposed framework and reveal valuable insights. [ABSTRACT FROM AUTHOR]

The high value of fiber-type Cannabis sativa L. (hemp) due to its phytochemicals has yet to be fully recognized and leveraged. Besides cannabidiol (CBD), which is the most prevalent non-psychoactive cannabinoid, hemp contains numerous other cannabinoids with unexplored bioactivities, in addition to various compound classes. Previous works have aimed to correlate chemical profiles of C. sativa inflorescences with important parameters, mostly based on experiments under controlled conditions. However, mapping studies that explore the phytochemical diversity of hemp in a more realistic context are crucial to guide decisions at multiple levels, especially in areas where hemp cultivation was recently re-authorized, including Mediterranean countries. In this work, a powerful strategy was followed to map the phytochemical diversity of cultivated hemp in Greece, being the first study of its kind for this environment. A panel of 98 inflorescence samples, covering two harvesting years, eleven geographical regions and seven commonly used EU varieties, were studied using a combination of targeted and untargeted approaches. Quantitative results based on UPLC-PDA revealed relatively constant CBD/THC (total) ratios, while profiling by LC-HRMS effectively probed the phytochemical variability of samples, and led to the annotation of 88 metabolites, including a multitude of minor cannabinoids. Multivariate analysis substantiated a strong effect of harvesting year in sample discrimination and related biomarkers were revealed, belonging to fatty acids and flavonoids. The effect of geographical region and, especially, variety on chemical variation patterns was more intricate to interpret. The results of this work are envisioned to enhance our understanding of the real-world phytochemical complexity of C. sativa (hemp), with a view to maximized utilization of hemp for the promotion of human well-being. Mapping the phytochemical complexity and diversity of cultivated hemp (Cannabis sativa L.) in Greece through combination of targeted and untargeted approaches. [Display omitted] • Phytochemical diversity mapping of cultivated hemp in Greece: a primary study. • Annotation of 88 metabolites in the hemp inflorescence samples (n = 98) by LC-HRMS. • Quantitative results for cannabinoids reveal a conserved CBD/THC (total) ratio. • Harvesting year exerts a strong effect on phytochemical profile differentiation. • Effects of geographical origin and variety on phytochemical profiles are less clear. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicle (UAV)-enabled communications have been proposed as a critical part of the beyond fifth-generation (5G) cellular networks. This type of communications is frequently characterized by line-of-sight (LoS) and dynamic propagation conditions. However, in various scenarios, the presence of large obstacles in the LoS path is unavoidable, resulting in shadowed fading environments. In this paper, a new channel model is proposed, in which the effects of mobility and shadowing are simultaneously considered. In particular, the performance of a UAV-based communication system operating in a shadowed double-scattering channel is analyzed. The new channel model is generic, since it models various fading/shadowing conditions, while it is in terms of easy-to-evaluate mathematical functions. Moreover, a low complexity UAV selection policy is proposed, which exploits shadowing-related information. The proposed scheme offers a reduction of the signal processing complexity, without any important degradation on the performance, as compared to alternatives approaches. In this context, a new analytical framework has been developed for investigating the performance of the new strategy. Finally, the main outcomes of this paper are also validated by empirical data, collected in an air-to-ground measurement campaign. [ABSTRACT FROM AUTHOR]

This paper studies the multivariate Ricean distribution, which is the most important distribution for modeling the magnitude of the received signal when line-of-sight propagation conditions exist. In this paper, assuming different mean values for the Ricean distributed random variables, generic expressions for the multivariate Ricean probability density function, cumulative distribution function, and the joint moments are derived in terms of integral representations. As an application example, these results have been used to analyze the performance of a multi-branch selection diversity receiver, operating in spatially correlated Ricean fading environment. Moreover, an asymptotic closed-form expression has been also provided, which approximates quite well to the exact one, and has been used to study various performance metrics. Finally, a complexity analysis has been performed and simulation results have been also presented. [ABSTRACT FROM AUTHOR]

In this paper, a new mode selection (MS) scheme for device-to-device (D2D) enabled cellular networks is proposed. The MS is carried out using a predefined signal-to-interference plus noise ratio (SINR) threshold and it aims to guarantee a minimum level of quality of service. With the new scheme, interfering effects are taken into consideration, while realistic assumptions for the acquisition of the channel information are made. Assuming a single-user case, an analytical framework is developed, which is based on the Markov-chain theory, and is used to study the system's performance. The various performance results obtained reveal that with the proposed MS, the probability of mode switching can be reduced (as compared to other systems), and thus, an increase on the overhead and signal processing is avoided. Moreover, a new approach is applied in a multi-user communication scenario, where a joint MS, resource allocation (RA), and scheduling optimization problem is formulated. The solution to this problem is based on a greedy heuristic algorithm that properly assigns the available resources among cellular users and D2D pairs. The joint MS, RA, and scheduling algorithm considers limited SINR awareness and it provides significant performance improvement in terms of sum-rate. [ABSTRACT FROM AUTHOR]

Antenna selection (AS) techniques are considered as ideal candidates for vehicle-to-vehicle communications, since they improve system's performance and simultaneously satisfy the hardware and signal processing constraints that exist in these systems. However, the achieved gain over single antenna links is affected by the fast varying wireless channel, since AS is frequently performed using outdated versions of the signal-to-noise ratio (SNR). In this paper, we propose an AS technique that exploits the stationarity of large-scale fading. In this context, by employing shadowing information as an AS criterion, the negative consequences of the outdated channel state information (CSI) can be alleviated, since large-scale fading varies more slowly than small-scale fading. The performance of the proposed technique is analyzed using the criteria of outage probability and average output SNR. It is shown that the proposed scheme outperforms the corresponding one that is based on outdated CSI, especially in scenarios with mild fading/shadowing channel conditions. Moreover, the influence of correlated shadowing on the system's performance has been also analytically investigated. The main results have been also verified by empirical data based on measurement campaigns in non-stationary communication conditions. [ABSTRACT FROM AUTHOR]

Fish and seafood are food products of high commercial value but with short shelf life. The objective of this article is to review the available packaging techniques and their applications on fish products, focusing on research and latest innovations. Modified atmosphere packaging (MAP) has been investigated for the selection of optimum packaging conditions for different fish products. Recent innovations include the combined application of MAP with other preservative factors, such as minimal processing or the addition of antioxidant and/or antimicrobial compounds. Smart packaging, including active packaging and quality control and monitoring systems (gas and moisture control, antimicrobial/antioxidant packaging, smart labels) and edible films and coatings are innovative packaging technologies, which may result in higher quality and extended shelf life of perishable food. The market for active and intelligent packaging methods is anticipated to rise significantly in the near future with their integration into fish packaging. [ABSTRACT FROM AUTHOR]

In this paper, we study a cooperative vehicle-to-vehicle (V2V) interference-limited communication system with decode-and-forward relaying operating over double-Nakagami (DN) fading channels. This distribution has been proposed as a fading model for scenarios where both the transmitter and the receiver are in motion, as is the case in V2V communications. For the purposes of our analysis, we introduce the bivariate DN distribution and derive statistical metrics for this distribution, such as the probability density function, the cumulative distribution function, and the moments. The new expressions have been employed to model the outdated channel state information (CSI) that is due to the fast time-varying nature of the wireless medium and the delay naturally existing between relay selection and data transmission instances. The analysis considers two relay selection schemes, according to the relay-destination channel quality, namely the well-known best relay selection (BRS) and a new one termed as threshold-based relay selection, which offers lower complexity than BRS. Using our analytical framework, exact and asymptotic performance results are obtained for the outage and the average symbol error probabilities, while the diversity order has been also evaluated. The numerical and simulation results corroborate our theoretical ones and quantify the impact of the outdated CSI, level of interference, and varying distances between the relay nodes and the final destination on the system's performance. [ABSTRACT FROM PUBLISHER]

Important statistical properties of the double-generalized Gamma (dGG) distribution are studied in this paper. The dGG distribution is suitable for modeling non-homogeneous double-scattering radio propagation fading conditions, which can be frequently observed in vehicle-to-vehicle (V2V) communications. In this context, important statistical metrics for the bivariate dGG distribution, such as the joint probability density function, cumulative distribution function, and the moments, are derived for the first time, while simplified expressions for the corresponding marginal statistical metrics are presented. Moreover, the second-order statistics of this distribution are also analytically studied. The derived analytical framework has been employed to analyze the performance of a transmit antenna selection system operating in V2V communication channels modeled by the dGG distribution. In this scenario, the impact of outdated channel state information (CSI) to the system’s performance is investigated in terms of various metrics, including the level crossing rate and the average fade duration. Furthermore, simplified asymptotic closed-form expressions for the outage probability have been derived to examine the achievable diversity and coding gains. Based on our analysis, insightful discussions are provided. It is shown that the diversity gain is independent from the number of transmit antennas when the available CSI becomes outdated. [ABSTRACT FROM PUBLISHER]

The development of new hybrid diversity methods has been demanded by the continuous growth of information rates. These schemes achieve improved balance between hardware complexity and performance, in relation to conventional ones. In this paper, a new hybrid switched diversity system is proposed. It is called generalized multi-branch switch and examine combining. The new scheme is a generalization of the classic one known as switch and examine combining with considerably improved performance. The performance of this scheme is analyzed over independent and identically distributed Nakagami-m fading channels using well-known performance and complexity measures. More specifically, important performance metrics, such as the outage probability, the average bit error rate, and the capacity under different adaptive transmission policies, have been analytically studied. It is shown that the proposed approach offers an important improvement on the performance, without considerably affecting the complexity. [ABSTRACT FROM AUTHOR]

Background Food engineering is at a crossroads. Inertia, combined with diminishing research funding, declining new academic positions, combined with disruptive and emerging competitive adjacent domains have a heavy toll on the field and its attractiveness for talented faculty members and students. The proliferation and flourishing of many bio-disciplines highlight the acute need for food engineering profession to revise its vision, strategy and missions and to reinvigorate and expand its horizon. Open innovation is a concept developed for commercial applications for gaining competitive advantages. Open innovation is based on utilizing both external and internal ideas and open channels for accessing and employing knowledge and solutions. Open innovation main philosophy should be adopted to integrate, assimilate and synergize food engineering core fundamental principles and to build on the accelerating developments in emerging knowledge, science and technology. Scope and approach To fully benefit from the vast future emerging opportunities, food engineering is faced with a plethora of demanding challenges (e.g., new curricula, innovation ecosystem, partnerships, creativity, multidisciplinary, entrepreneurship, sustainability, food and nutrition security, population growth, health and wellness, nutrition, bioavailability). ‘ Enginomics’ (engineering + omics) - a new term coined to express some of the major food engineering future challenges that holistically combines food processing and human internal digestion. It calls for studying human internal transport phenomena, utilization of new techniques (e.g., micro-processing, virtualization) for modelling and simulation, emerging topics (e.g., bioavailability, signaling, satiety, personalized nutrigenomics, targeting, pro- and prebiotics, nanotechnology, biotechnology), as well as traditional food and product engineering. Key findings and conclusions The food engineering domain should rise to future mounting challenges and opportunities by redefining its vision and strategy recapturing its significant roles, and stopping the loss of its graduates in the competitions with other fields. Several paradigm shifts are recommended including reinventing its curricula in pursuing of excellence with a start-up-university ( innoversity ) mentality, new mindset for promoting open innovation, implementing virtualization, embracing enginomics and social responsibility. As a part of enginomics and health and wellness, the development of low cost, fast and accurate bioavailability tests is required. Open innovation provides food engineers with the unique prospects for spearheading the four-helix innovation ecosystem. Both basic and applied science and utilizing of the most advanced and up-to-date technologies and scientific breakthroughs are paramount. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 66-year-old male patient with acquired hemophilia A (AHA) and its first-line treatment. It discusses the inhibitor eradication prednisolone, with cyclophosphamide with dose of rituximab, responsiveness to prednisolone pulse therapy, switching of therapy to combination of bendamustine, prednisolone.

In this paper, the effects of interference on composite fading environments, where multipath fading coexists with shadowing, are investigated. Based on some mathematical convenient expressions for the sum of squared \cal K -distributed random variables, which are derived for the first time, important statistical metrics for the signal to interference and noise ratio (SINR) are studied for various cases including non identical, identical and fully correlated statistics. Furthermore, our analysis is extended to multi-channel receivers and in particular to selection diversity (SD) receivers, investigating two distinct cases, namely, signal-to-noise ratio based and SINR-based SD. For all scenarios, simplified expressions are also provided for the interference limited case, where the influence of thermal noise is ignored. The derived expressions are used to analyze the performance, in terms of the average bit error probability (ABEP) and the outage probability (OP) , of such systems operating over composite fading environments. A high SNR analysis is also presented for the OP and the ABEP, giving a clear physical insight of the system's performance in terms of the diversity and coding gains. The analysis is accompanied by numerical evaluated results, clearly demonstrating the usefulness of the proposed theoretical framework. [ABSTRACT FROM PUBLISHER]

In this paper, we analytically evaluate the average symbol error probability (SEP) of rectangular quadrature amplitude modulation (QAM) signalling in composite fading channels modelled by the generalized- K ( K G ) distribution. The analysis is based on a fast converging infinite series representation of the average of the product of two Gaussian-Q functions over K G fading that has been extracted. Considering integer and a half values for the distribution's shaping parameters, exact closed-form expressions have been also derived. Numerical evaluated results, complemented by equivalent computer simulated ones, are presented to verify the accuracy of the proposed analysis. [ABSTRACT FROM AUTHOR]

Abstract: Distributed-Multiple Input Multiple Output (D-MIMO) communication systems consist an attractive solution for networks with increased capacity demands. In these systems, the required information that needs to be exchanged among the network elements increases the data overhead and hence decreases the effective sum-rate (or throughput). Recently, it was shown that the total required overhead for D-MIMO networks can be reduced through its partitioning into smaller orthogonal D-MIMO segments. In this paper, a new scheme is proposed for further improving the effective sum-rate of D-MIMO networks by means of exploiting the spatial channels correlation within the D-MIMO network. Such effects can be observed in dense networks and the scope of the proposed correlation exploitation techniques is to avoid sending redundant feedback information. Numerical results indicate that important savings can be achieved when this novel method is applied under different wireless environments. [Copyright &y& Elsevier]

Highlights: [•] Gilthead seabream fillets were osmotically treated and stored under refrigeration. [•] Osmotic treatment extended significantly the shelf life of chilled fish fillets. [•] Pseudomonas dominated spoilage of untreated and osmotically treated fish fillets. [•] An Arrhenius-type model described the effect of processing on Pseudomonas growth. [•] Model can be used as a tool for predicting shelf life of osmotically treated fish fillets. [ABSTRACT FROM AUTHOR]

Objective: DNA microarray technology yields expression profiles for thousands of genes, in a single hybridization experiment. The quantification of the expression level is performed using image analysis. In this paper we introduce a supervised method for the segmentation of microarray images using classification techniques. The method is able to characterize the pixels of the image as signal, background and artefact. Methods and material: The proposed method includes five steps: (a) an automated gridding method which provides a cell of the image for each spot. (b) Three multichannel vector filters are employed to preprocess the raw image. (c) Features are extracted from each pixel of the image. (d) The dimension of the feature set is reduced. (e) Support vector machines are used for the classification of pixels as signal, background, artefacts. The proposed method is evaluated using both real images from the Stanford microarray database and simulated images generated by a microarray data simulator. The signal and the background pixels, which are responsible for the quantification of the expression levels, are efficiently detected. Results: A quality measure (qindex) and the pixel-by-pixel accuracy are used for the evaluation of the proposed method. The obtained qindex varies from 0.742 to 0.836. The obtained accuracy for the real images is about 98%, while the accuracies for the good, normal and bad quality simulated images are 96, 93 and 71%, respectively. The proposed classification method is compared to clustering-based techniques, which have been proposed for microarray image segmentation. This comparison shows that the classification-based method reports better results, improving the performance by up to 20%. Conclusions: The proposed method can be used for segmentation of microarray images with high accuracy, indicating that segmentation can be improved using classification instead of clustering. The proposed method is supervised and it can only be used when training data are available. [ABSTRACT FROM AUTHOR]

BACKGROUND: Intravascular ultrasound (IVUS) is an invasive imaging modality that provides high resolution cross-sectional images permitting detailed evaluation of the lumen, outer vessel wall and plaque morphology and evaluation of its composition. Over the last years several methodologies have been proposed which allow automated processing of the IVUS data and reliable segmentation of the regions of interest or characterization of the type of the plaque. OBJECTIVE: In this paper we present a novel methodology for the automated identification of different plaque components in grayscale IVUS images. METHODS: The proposed method is based on a hybrid approach that incorporates both image processing techniques and classification algorithms and allows classification of the plaque into three different categories: Hard Calcified, Hard-Non Calcified and Soft plaque. Annotations by two experts on 8 IVUS examinations were used to train and test our method. RESULTS: The combination of an automatic thresholding technique and active contours coupled with a Random Forest classifier provided reliable results with an overall classification accuracy of 86.14%. CONCLUSIONS: The proposed method can accurately detect the plaque using grayscale IVUS images and can be used to assess plaque composition for both clinical and research purposes. [ABSTRACT FROM AUTHOR]

Background: Intravascular ultrasound (IVUS) is an invasive imaging modality that provides high resolution cross-sectional images permitting detailed evaluation of the lumen, outer vessel wall and plaque morphology and evaluation of its composition. Over the last years several methodologies have been proposed which allow automated processing of the IVUS data and reliable segmentation of the regions of interest or characterization of the type of the plaque. Objective: In this paper we present a novel methodology for the automated identification of different plaque components in grayscale IVUS images. Methods: The proposed method is based on a hybrid approach that incorporates both image processing techniques and classification algorithms and allows classification of the plaque into three different categories: Hard Calcified, Hard-Non Calcified and Soft plaque. Annotations by two experts on 8 IVUS examinations were used to train and test our method. Results: The combination of an automatic thresholding technique and active contours coupled with a Random Forest classifier provided reliable results with an overall classification accuracy of 86.14%. Conclusions: The proposed method can accurately detect the plaque using grayscale IVUS images and can be used to assess plaque composition for both clinical and research purposes. [ABSTRACT FROM AUTHOR]

The cooperative aerial and device-to-device (D2D) networks employing non-orthogonal multiple access (NOMA) are expected to play an essential role in next-generation wireless networks. Moreover, machine learning (ML) techniques, such as artificial neural networks (ANN), can significantly enhance network performance and efficiency in fifth-generation (5G) wireless networks and beyond. This paper studies an ANN-based unmanned aerial vehicle (UAV) placement scheme to enhance an integrated UAV-D2D NOMA cooperative network.The proposed placement scheme selection (PSS) method for integrating the UAV into the cooperative network combines supervised and unsupervised ML techniques. Specifically, a supervised classification approach is employed utilizing a two-hidden layered ANN with 63 neurons evenly distributed among the layers. The output class of the ANN is utilized to determine the appropriate unsupervised learning method—either k-means or k-medoids—to be employed. This specific ANN layout has been observed to exhibit an accuracy of 94.12%, the highest accuracy among the ANN models evaluated, making it highly recommended for accurate PSS predictions in urban locations. Furthermore, the proposed cooperative scheme allows pairs of users to be simultaneously served through NOMA from the UAV, which acts as an aerial base station. At the same time, the D2D cooperative transmission for each NOMA pair is activated to improve the overall communication quality. Comparisons with conventional orthogonal multiple access (OMA) and alternative unsupervised machine-learning based-UAV-D2D NOMA cooperative networks show that significant sum rate and spectral efficiency gains can be harvested through the proposed method under varying D2D bandwidth allocations. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Hemostasis and inflammation are two tightly interrelated systems in the host''s response to infection. Thrombin generation in sepsis plays a crucial role in enhancing and modulation of inflammation. The present study aimed to investigate the course of thrombin generation in patients with severe sepsis, and its correlation with outcome. Materials and Methods: Thrombin generation was measured in platelet-poor plasma from 32 healthy controls and 75 patients with severe sepsis using the commercially available Calibrated Automated Thrombography. Samples were taken within 24 hours of the diagnosis of severe sepsis (t1) as well as on day 2 (t2), day 3 or 4 (t3) and between day 6 to 8 (t4), while this was done only once in healthy controls. The assay was run with and without the addition of thrombomodulin. Clinical data were also collected at the same time points. Results: Except for endogenous thrombin potential, there was significant difference between patients and controls regarding peak thrombin, lag time and time to thrombin peak. Twelve patients (16%) died in the ICU. There was no significant difference in endogenous thrombin potential between survivors and non-survivors of sepsis. Thrombin peak was higher in survivors than non-survivors at all time points, with a significant difference at t2 and t4. The lag time and time to thrombin peak were shorter in non-survivors than in survivors at t1 and t3. Conclusions: While thrombin peak shows a positive correlation with survival, the lag phase and time to thrombin peak may be signs of impending DIC. The endogenous thrombin potential does not have any prognostic importance. [Copyright &y& Elsevier]

Adjunctive percutaneous coronary intervention (PCI) performed between 2 and 24 hours after thrombolysis administered to a patient with an ST elevation myocardial infarction (STEMI) appears beneficial and safe. The rationale for routinely following fibrinolysis with PCI is that many patients have a persistent reduction in flow in the infarct-related artery; although fibrinolysis restores patency (TIMI grade 2 or 3) in 80% of infarct-related arteries, normalization of blood flow (TIMI grade 3) is seen in only 50 to 60% of arteries. Adjunctive PCI has been directly compared to a strategy of fibrinolysis and standard care (either PCI for a clinical indication or routine late PCI) in the TRANSFER AMI, GRACIA-1, NORDISTEMI, CARESS-in-AMI, and SIAM III trials, and found to have better outcomes. Based on these results, the 2010 European Society of Cardiology (ESC) guidelines recommend routine urgent PCI after successful fibrinolysis within 24 hours (class I recommendation, level of evidence A). [ABSTRACT FROM AUTHOR]

The objective of the study was the kinetic modeling of the effect of storage temperature on the quality and shelf life of chilled fish, modified atmosphere-packed (MAP), and osmotically pretreated with the addition of nisin as antimicrobial agent. Fresh gilthead seabream ( Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (DE 47) plus 5% NaCl. Water loss, solid gain, salt content, and water activity were monitored throughout treatment and treatment conditions were selected for the shelf life study. Untreated and osmotically pretreated slices with and without nisin (2 × 104 IU/100 g osmotic solution), packed in air or modified atmosphere (50% CO2–50% air), and stored at controlled isothermal conditions (0, 5, 10, and 15 °C) were studied. Quality assessment and modeling were based on growth of several microbial indices, total volatile nitrogen, trimethylamine nitrogen, lipid oxidation (TBARS), and sensory scoring. Temperature dependence of quality loss rates was modeled by the Arrhenius equation, validated under dynamic conditions. Pretreated samples showed improved quality stability during subsequent refrigerated storage, in terms of microbial growth, chemical changes, and organoleptic degradation. Osmotic pretreatment with the addition of nisin in combination with MAP was the most effective treatment resulting in significant shelf life extension of gilthead seabream fillets (48 days compared to 10 days for the control at 0 °C). [ABSTRACT FROM AUTHOR]

The capacity of correlated generalized Gamma (GG) fading channels with dual-branch selection diversity (SD) reception and channel side information (CSI) available at both the transmitter and the receiver is studied and analyzed. In particular, the capacity is evaluated under four adaptive transmission policies defined according to the operational CSI: 1) optimal power and rate adaptation (OPRA); 2) constant power with optimal rate adaptation (ORA); 3) channel inversion with fixed rate (CIFR); and 4) truncated CIFR (TIFR). Under these four adaptation policies, fast converging infinite series expressions for the capacity are derived and evaluated. Furthermore, for the simplifying cases of independent GG fading channels and/or single-channel reception (i.e., no diversity), closed-form expressions have been obtained. Previously published expressions are shown to be special cases of the derived expressions. Performance evaluation results obtained by means of numerical analysis clearly demonstrate the usefulness and accuracy of the analysis. [ABSTRACT FROM AUTHOR]

The correlated bivariate generalized-K (KG) distribution, with not necessarily identical shaping and scaling parameters, is introduced and studied. This composite distribution is convenient for modeling multipath/shadowing correlated fading environments when the correlations between the signal envelopes and their powers are different. Generic infinite series expressions are derived for the probability density function (PDF), the cumulative distribution function (CDF) and the joint moments. Assuming identical shaping parameters, simpler expressions for the PDF, CDF and the characteristic function (CF) are provided, while the joint moments are derived in closed form. Furthermore, the PDFs of the product and ratio of two correlated KG random variables are obtained. Capitalizing on these theoretical expressions for the statistical characteristics of the correlated KG distribution, the performance analysis of various diversity reception techniques, such as maximal ratio combining (MRC), equal gain combining (EGC) and selection diversity (SD), over bivariate KG fading channels is presented. For the SD, the outage probability is studied, while for the MRC and EGC the average bit error probability is obtained. The proposed analysis is accompanied by numerical results, clearly demonstrating the usefulness of the theoretical approach as well as the appropriateness of the KG distribution to model multipath/shadowing fading channels. [ABSTRACT FROM AUTHOR]

Multiplex fluorescent in situ hybridization (M-FISH) is a recently developed chromosome imaging technique where each chromosome class appears to have a distinct color. This technique not only facilitates the detection of subtle chromosomal aberrations but also makes the analysis of chromosome images easier; both for human inspection and computerized analysis. In this paper, a novel method for segmentation and classification of M-FISH chromosome images is presented. The segmentation is based on the multichannel watershed transform in order to define regions of similar spatial and spectral characteristics. Then, a Bayes classifier, task-specific on region classification, is applied. Our method consists of four basic steps: 1) computation of the gradient magnitude of the image, 2) application of the watershed transform to decompose the image into a set of homogenous regions, 3) classification of each region, and 4) merging of similar adjacent regions. The method is evaluated using a publicly available chromosome image database and the obtained overall accuracy is 82.4%. By introducing the classification of each watershed region, the pro- posed method achieves substantially better results compared to other methods at a lower computational cost. The combination of the multichannel segmentation and the region-based classification is found to improve the overall classification accuracy compared to pixel-by-pixel approaches. [ABSTRACT FROM AUTHOR]

The performance of a class of generalized-selection combining (GSC) receivers operating over independent but non- identically distributed Weibull fading channels is studied. We consider the case where the two branches with the largest instantaneous signal-to-noise ratio (SNR), from a total of L available, GSC(2, L) are selected. By introducing a novel property for the product of moments of ordered Weibull random variables, convenient closed form expressions for the moments of the GSC(2,L) output SNR are derived. Using these expressions, important performance criteria, such as average output SNR and amount of fading, are obtained in closed form. Furthermore, employing the Padé approximants theory and the moment-generating function approach, outage and bit-error rate performance are studied. An attempt is also made to identify the equivalency between the Weibull and the Rice fading channel, which is typically used to model the mobile satellite channel. We present various numerical performance evaluation results for different modulation formats and channel conditions. These results are complemented by equivalent computer simulated results which validate the accuracy of the proposed analysis. [ABSTRACT FROM AUTHOR]

Objective: Activation and suppression of immune responses are crucial events during sepsis. Based on substantial new data, a complex picture of differential immune-enhancing and immunosuppressive actions of adrenocortical steroids is emerging. The adrenal androgen dehydroepiandrosterone and its precursor, dehydroepiandrosterone-sulfate, show a considerable decrease with increasing age and serve as functional antagonists to endogenous glucocorticoids. Therefore, we examined time-dependent changes in dehydroepiandrosterone, dehydroepiandrosterone-sulfate, cortisol, adrenocorticotropin, and inflammatory variables in surviving and nonsurviving patients with severe sepsis.Design: Prospective observational study in consecutive patients.Setting: Medical and interdisciplinary intensive care units in two university hospitals and one city hospital.Patients: Thirty nonsurgical patients (25 men and 5 women) with severe sepsis (American College of Chest Physicians/Society of Critical Care Medicine criteria); 15 survivors (mean age, 54 +/- 14 yrs; Acute Physiology and Chronic Health Evaluation III score, 59 +/- 35) and 15 nonsurvivors (mean age, 63 +/- 15 yrs; Acute Physiology and Chronic Health Evaluation III score, 67 +/- 24) were included. Hormones were compared individually and between survivors/nonsurvivors by sequential blood drawings from early sepsis till time of recovery/death.Interventions: None.Measurements and Main Results: During early sepsis, cortisol (nmol/L) was not significantly higher in survivors than nonsurvivors (750 +/- 121 vs. 454 +/- 92, p <.08) and decreased in survivors (p <.01) during late sepsis. During early sepsis, dehydroepiandrosterone-sulfate (percentage of age-matched normal levels) was higher in survivors than nonsurvivors (85 +/- 19 vs. 22 +/- 7, p <.01). Dehydroepiandrosterone-sulfate decreased in survivors (p =.0001) but remained low in nonsurvivors during late sepsis. Dehydroepiandrosterone (percentage of age-matched normal levels) was not significantly elevated in survivors compared to nonsurvivors during early sepsis (282 +/- 42 vs. 214 +/- 63, p <.08). Dehydroepiandrosterone decreased in survivors (p <.01) but not in nonsurvivors during late sepsis. Linear regression for dehydroepiandrosterone levels showed a reconstitution of age dependence only in survivors during recovery. Adrenocorticotropin levels did not change. The dehydroepiandrosterone-sulfate/cortisol ratio decreased significantly in both survivors and nonsurvivors, whereas dehydroepiandrosterone/cortisol ratio only decreased in survivors during course of sepsis.Conclusions: During sepsis, adrenal androgens and glucocorticoids show a diverse time-dependent course in survivors and nonsurvivors. [ABSTRACT FROM AUTHOR]

A three-phase busbar arrangement with straight rigid conductors carrying short-circuit currents is investigated. Calculations are made assuming steady-state ac current with a peak value equal to the peak value of the short-circuit current. The electromagnetic forces are calculated by solving the electromagnetic field diffusion equation numerically, using finite elements. The results are compared with results calculated according to the IEC Standard 865/93. A large number of arrangements have been examined, covering a wide variety of cases, as used in ac indoor installations of medium and low voltage. For this purpose, the finite element procedure has been fully automated to a degree of minimal human intervention. A let-it-grow artificial neural network (ANN) has been utilized for the automatic mesh generation. The forces calculated were in all cases in excellent agreement with the IEC Standard 865/93. [ABSTRACT FROM AUTHOR]

In this paper two active MMIC mixers for RF front-end applications are described. A down-converter that converts an RF signal ( f_{\rm RF} = 10.45\,\hbox{GHz} ) into an IF signal ( f_{\rm IF} = 0.95\,\hbox{GHz} ) using an LO signal f_{\rm LO} = 9.5\,\hbox{GHz} and an up-converter that performs the opposite process have been fabricated. The down-converter is designed using the topology of a dual-gate pHEMT, while the up-converter is implemented in the form of a double balanced mixer using the topology of the Gilbert cell and the occupied areas are approximately 0.78 mm 2 and 3.86 mm 2 respectively. Both mixers present conversion gain, very low input and output return losses, very good isolation between all of their ports and the required LO power is quite low, while the up-converter contains on chip, except for the dc-bias and matching sub-circuits, the required LO and RF baluns. Both circuits have been fabricated using the H-40 process of GEC-Marconi. Section 1 presents fundamentals on mixer theory and mixer design while in Section 2 the characteristics of H-40 process are described. In Section 3 and in Section 4 the designing, the simulated and the measured results of the down-converter and the up-converter are presented, respectively. [ABSTRACT FROM AUTHOR]

In this paper a MMIC QPSK modulator is described. The bit rate of the baseband signal is 155\,\hbox{Mbits/sec} , while the frequency of the carrier is f_{\rm LO} = 10\,\hbox{GHz} . The modulation is performed directly at the RF band and therefore an IF stage is not necessary. The design contains all the necessary sub-circuits except for the demultiplexer and the low-pass filters, which are used so that the bandwidth of the binary waves can be reduced. The mixers that are contained in the circuit are not the typical Gilbert cells and as a result they occupy a much smaller area (half). The circuit needs no external LO coupler and no RF chocks. The F-20 process of GEC Marconi was used for designing the modulator. The occupied area is approximately 12\,\hbox{mm}^{2} . Section 1 presents fundamentals on Quadriphase Shift Keying (QPSK), while in Section 2 the characteristics of the F-20 process are described. In the following Sections the sub-circuits, the complete circuit, and its simulated results are presented. [ABSTRACT FROM AUTHOR]

Investigates the applicability of an Arrhenius model for the combined effect of temperature and carbon dioxide packaging on the spoilage microflora of fish. Growth of the spoilage bacteria Pseudomonas spp., Shewanella putrefaciens, Brochothrix thermosphacta and lactic acid bacteria; Changes in the microbial flora of red mullet.

Time/temperature integrators (TTI) have a potential for monitoring time-temperature history of perishable foods, including dairy products. To correlate the end of shelf life of dairy products with different TTI' s, kinetic data for growth of a dairy spoilage microorganism was obtained. Both Arrhenius and square root equations were used to model the growth of Pseudomonas fragi. A significant negative history effect was observed for P. fragi growth rate whereas history effect was positive on the lag phase, under certain nonisothermal conditions. A correlation scheme of P. fragi growth was developed with the TTI response. The application of TTI' s for dairy products is feasible despite the history effects. [ABSTRACT FROM AUTHOR]

Cannabidiol (CBD) and cannabidiolic acid (CBDA) represent the most abundant non-psychoactive cannabinoids in fiber-type Cannabis sativa L. (hemp) and both have demonstrated high therapeutic potential. Hence, efficient extraction coupled with reliable determination of these compounds is crucial for informed utilization of hemp and is increasingly needed in the present state of harmonization efforts. In this context, a systematic approach for extraction optimization was followed, which initially involved comparison of three widely available extraction techniques, i.e. ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and dynamic maceration (DM). These were applied on samples of different hemp varieties (n = 3) using ethanol as a safe and efficient solvent. UAE showed the most promising results and was further optimized by means of response surface methodology (RSM), based on a circumscribed central composite design. The conditions maximizing CBD, CBDA, and total CBD content as well as extraction yield were determined with high desirability (0.97) and were experimentally confirmed. The optimized UAE method was also compared with a previously reported extraction procedure, demonstrating superior performance. For the quantitation of CBD and CBDA in hemp extracts, a reversed-phase UPLC-PDA method was developed and validated. Chromatographic separation was achieved in less than 10 min, while satisfactory results for linearity (R 2 > 0.996), precision (RSD < 2.0%), and accuracy (recovery rates of 93.1–101.0%) were obtained for both analytes. Limits of detection were determined as 0.07 and 0.04 μg mL−1 for CBD and CBDA, respectively, indicating sufficient sensitivity. The good performance of the method was verified by the evaluation of additional parameters (e.g. matrix effect, extraction recovery), which was largely enabled by the use of isolated standards. The whole analytical workflow, involving both optimized UAE extraction and UPLC-PDA determination, entails simplified manipulation and may offer a reliable and cost-effective approach for routine quality control of hemp regarding the principal cannabinoids. Image 1 • A validated UPLC-PDA method for the determination of major cannabinoids in hemp. • Reliable quantitation of CBD and CBDA in less than 10 min using a C 18 -PFP column. • Comparison of three extraction techniques using different hemp varieties. • Optimization of ultrasound-assisted extraction with ethanol via experimental design. • Method performance indicates suitability for quality assessment purposes. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented entitled "Coagulation monitoring with thrombin generation test during endoscopic extraperitoneal radical prostatectomy for prostate cancer in a patient with severe haemophilia B," published within the issue.

Unmanned aerial vehicles (UAVs) will be an integral part of the next generation wireless communication networks. Their adoption in various communication-based applications is expected to improve coverage and spectral efficiency, as compared to traditional ground-based solutions. However, this new degree of freedom that will be included in the network will also add new challenges. In this context, the machine-learning (ML) framework is expected to provide solutions for the various problems that have already been identified when UAVs are used for communication purposes. In this article, we provide a detailed survey of all relevant research works, in which ML techniques have been used on UAV-based communications for improving various design and functional aspects such as channel modeling, resource management, positioning, and security. [ABSTRACT FROM AUTHOR]

Background The Irritable Bowel Syndrome Severity Scoring System (IBS-SSS) is a selfadministered questionnaire that categorizes patients according to symptom severity. We aimed to translate and adapt the English IBS-SSS, validate the Greek version, and detect factors predictive of IBS severity. Methods The original English version was obtained from the Rome Foundation, and the final Greek version arose through a process of translation, comprehensibility evaluation and backtranslation. The 141 participants enlisted in the study were enrolled from 2 tertiary hospitals and were divided into 2 groups (98 patients and 43 healthy volunteers). We evaluated the questionnaire properties based on COSMIN criteria. Results The recruited patients reported either diarrhea-predominant (34.7%), constipationpredominant (28.6%), or mixed subtype (36.7%) IBS. No significant variations were found regarding the frequency and intensity of abdominal pain and flatulence among the 3 IBS subtypes. Severity scores among healthy volunteers were significantly lower compared to IBS patients, irrespective of their disease subtype (P<0.001). The Cronbach coefficient (a) was calculated at 0.953, suggesting high inter-item internal consistency. The intraclass correlation coefficient was calculated and found to be high, suggesting good responsiveness of the questionnaire. Two-way MANOVA evaluation showed that demographic variables (age, family status, body mass index [BMI], smoking, and alcohol consumption) in the Greek population affect the IBS-SSS score and syndrome severity. Conclusions The Greek version of IBS-SSS is a reliable, valid and responsive tool for assessing Greek IBS patients' symptom severity. Older age, smoking, alcohol use and higher BMI are indicative of greater symptom severity. [ABSTRACT FROM AUTHOR]

In this paper, an airborne multi-user (MU) multiple-input multiple-output (MIMO) communication system is investigated, consisting of multiple users sources, multiple users destinations, and an aerial platform acting as a decode-and-forward (DF) relay. In this context, a novel three-dimensional (3-D) geometry-based optimization method for the relay location is proposed and expressions for the outage probability are presented. The results highlight the impact of the relay position, power allocation, fading severity, and number of antennas on the system performance. [ABSTRACT FROM AUTHOR]

The article reports on the alert issued by the U.S. Food and Drug Administration (FDA) on catheter-delivered Amplatzer atrial septal occluder due to a small risk of potentially life-threatening complications. Topics discussed include the regulator's recommendation against device removal for patients who have the Amplatzer atrial septal occluder unless physicians deemed otherwise. Also mentioned is the case of a 42 year old man who got his device removed.

The aim of this study was to monitor and characterize Greek coffee staling during home storage (secondary shelf life, SSL) using sensory evaluation techniques. Storage temperature (T) and product water activity (aw) are considered as the major factors affecting SSL. Water sorption isotherms fitted to Guggenheim Anderson–de Boer model were used to predict product stability; coffee samples were stable at aw < 0.52. Coffee samples equilibrated at aw = 0.15 (the fresh sample), 0.22, 0.33, and 0.52 were stored at T = 25 °C, 35 °C, and 45 °C under simulated home storage conditions. Samples were obtained at appropriate times for each T and aw condition and sensorially evaluated. Greek coffee brews were prepared and freshly served during sensory evaluation. The use of Weibull hazard analysis provided an effective approach to SSL determination as a function of T and aw. SSL values ranged from 20 (Τ = 45 °C, aw = 0.52) to 104 days (Τ = 25 °C, aw = 0.15). Quality loss based on coffee aroma changes (aroma quality, aroma intensity, aftertaste, off‐flavor) was also studied (Si, sensory scoring using 9‐point magnitude scale) and kinetically modeled. Quality loss rates (ki) were calculated and used to predict SSL values. Based on the results of both Weibull hazard analysis and sensory scoring of individual aroma characteristics, it was concluded that the lowest SSL was calculated for aw = 0.52 at T = 35 °C to 45 °C. The temperature dependence of aftertaste, aroma quality loss, and off‐flavor production was not statistically significant for 0.15 < aw < 0.33 (P > 0.05); the aroma intensity was the most sensitive parameter. Practical Applications: Secondary shelf life (SSL) represents the time after pack opening during which a food maintains an acceptable quality level. During home/catering usage, coffee is not consumed immediately after pack opening. During consumption, quality degradation reactions proceed with higher rates due to variable storage conditions mainly related to atmosphere changes in the pack, leading to the entrance of oxygen/moisture and temperature. Therefore, SSL is important, and can be used as a tool for product management during consumption reducing food waste. There is a lack of studies dealing with SSL prediction of coffee, while no studies have been carried out on Greek coffee. [ABSTRACT FROM AUTHOR]

The authors reflect on remodeling the left atrium (LA) in chronic mitral regurgitation (MR). They reference the retrospective study by Song and colleagues in the same issue which investigates the relationships between the echocardiographic findings and N-terminal B-type natriuretic peptide levels and the left ventricular (LV) reverse remodeling following valve repair in patients with chronic MR. They contend that left ventricular remodeling prevention has improved outcome than treatment.

Presents a letter to the editor concerning comparison of doxazosin with or without tolterodine in men with symptomatic bladder outlet obstruction and an overactive bladder.

This communication investigates the validity of application of a multiple-scattering model to a dual-polarized multiple-input-multiple-output land mobile satellite (LMS) channel based on a measurement campaign. Two LMS link scenarios in an urban pedestrian environment are examined. In the first one, the transmitter was located at the top of a tall building and in the second one, on an airship. The third-order scattering model is utilized to statistically characterize the measured channels, and the results reveal that the model provides an excellent fit to the LMS composite fading amplitude in the line-of-sight (LOS) and non-LOS scenarios. For this generic radio channel, asymptotic expressions for the theoretical probability density function and the cumulative distribution function are derived. The comparison of the third-order scattering model with existing LMS ones showed that it provides better overall accuracy together with a physical interpretation of the propagation mechanisms involved. [ABSTRACT FROM AUTHOR]