A cross‐layer information centric‐relay transmission strategy for MIMO–OFDMA multicellular networks

Power control has been a standard issue in modern wireless communications. As a result, several cooperative schemes have been developed towards reducing the downlink transmission power. One possible approach is the use of relays that forward information from the base station (BS) to the mobile stations (MSs). However, up to now, the proposed relaying schemes are focusing solely on channel characteristics. In this work, a novel, content‐aware relaying scheme is introduced, where the MSs can act as active relays based on their requested content and channel quality. Content awareness is achieved with a cross‐layer algorithm, which considers an information‐centric networking layer. The performance of the proposed approach has been evaluated considering a multiple input multiple output (MIMO) cellular configuration with one tier of cells around the central cell, where the downlink transmission power (in terms of mean values) has been compared to the typical non‐content‐aware case. For this reason, a hybrid system—link level simulator has been developed that executes independent Monte Carlo (MC) simulations in parallel. Moreover, the orthogonal frequency division multiple access (OFDMA) physical layer protocol has been employed as well, in order to comply with fourth generation standards. The derived results indicate that, compared to the non‐content‐aware case, the proposed relay transmission algorithm can provide up to 7/17% transmission power gain in medium or highly loaded networks (i.e., 10% and 40% blocking probabilities, respectively) in a symmetric 2 × 2 MIMO configuration (i.e., equal number of transmit and receive antennas). Moreover, compared to the case where no relay transmission is supported, then the aforementioned gain can reach up to 20%. Finally, the proposed algorithm can provide up to 25% reduction on the overall transmission delay from the relay node to the destination compared to the non‐content‐aware case. Copyright © 2014 John Wiley & Sons, Ltd.     

A Delay Optimal Scheduling Policy for Real Time Services in WCDMA Systems

Enhanced Uplink operation of WCDMA-UMTS systems utilizes fast Node B scheduling and a short Transmission Time Interval (TTI) of 2 ms. The scheduling decisions are based on Scheduling Information (SI) sent from each User Equipment (UE) to the Node B. The weakness of the existing scheduling framework is that the SI does not include information regarding the delay sensitivity of each traffic flow, as well as the actual delay that the buffered data have experienced, especially for real-time services. In this paper, we propose the inclusion of such information in SI by introducing modifications into the respective 3GPP specifications. Thus, we propose a Delay Aware Channel Prioritization (DACP) criterion optimized for real-time services. Furthermore, we propose a DACP-based packet Scheduler (DACP-S) which is able to dynamically manage the Enhanced Dedicated Channel’s (E-DCH) transmissions and offer Quality of Service differentiation. The performance of the proposed scheme is evaluated by means of system level simulations.     

Low-frequency Raman scattering in alkali tellurite glasses

Raman scattering has been employed to study the alkali-cation size dependence and the polarization characteristics of the low-frequency modes for the glass-forming tellurite mixtures, 0·1M₂O–0·9TeO₂ (M = Na, K, Rb and Cs). The analysis has shown that the Raman coupling coefficient alters by varying the type of the alkali cation. The addition of alkali modifier in the tellurite network leads to the conversion of the TeO₄ units to TeO₃ units with a varying number of non-bridging oxygen atoms. Emphasis has also been given to the low-frequency modes and particular points related to the low-frequency Raman phenomenology are discussed in view of the experimental findings.     

Water-to-Air Mass Transfer of VOCs: Laboratory-Scale Air Sparging System

Nonequilibrium air-water mass transfer experiments for six volatile organic compounds (VOCs) were conducted using a bench-scale air sparging system. VOCs used were carbon tetrachloride, trichloroethylene, tetrachloroethylene, chloroform, dichloromethane, and toluene. The average particle size of the porous media used ranged from 0.278 to 1.71 mm. The air-water mass transfer coefficients were estimated by fitting the experimental data to a lumped parameter model. The model assumed that the saturated porous media under air sparging conditions consisted of two zones. In the “mass transfer” zone, VOCs were directly impacted by the flow of air in the air channels, while in the “bulk water” zone, VOCs were not directly affected by the air flow in the air channels. The estimated air-water mass transfer coefficients (KGa) were found to increase for higher injected air flow rates and for larger mean particle sizes of porous media but were inversely proportional to the Henry's law constant of the VOCs. An empirical correlation was developed by correlating the Sherwood number with the Péclet number, the Henry's law constant, and the mean particle size of porous media. The estimated fraction (F) of the total volume of the porous media directly affected by air channels was between 5 and 20% for fine sand, indicating that a small fraction of the porous media was affected by the advecting air stream.     

Headspace Solid Phase Micro Extraction Gas Chromatographic Determination of Fenthion in Human Serum

A simple and effective analytical procedure was developed for the determination of fenthion residues in human serum samples. The sample treatment was performed using the headspace solid-phase micro extraction with polyacrylate fiber, which has the advantage to require low amount of serum (1 mL) without tedious pre-treatment. The quantification of fenthion was carried out by gas chromatography-mass spectrometry and the recoveries ranged from 79 to 104% at two spiking levels for 6 replicates. Detection and quantification limits were calculated as 1.51 and 4.54 ng/mL of serum respectively. Two fenthion metabolites fenoxon and fenthion–sulfoxide were also identified.     

2D fragmented object reconstruction with the use of the chromatic and thematic content

In this article, we examine the reconstruction of seventeenth century BC fragmented wall paintings, excavated at Akrotiri, Santorini, Greece. We use a previously presented algorithm for obtaining potential fragment matches based on the shape of the fragments. We then extract additional information from the fragments?? images in order to drastically reduce the number of potential matches proposed by this system. In particular, we examine the performance of several criteria that make use of the chromatic (color) content of the fragments?? images near the edge of the piece. We also extract additional information regarding the thematic content of the fragments; this information is then used to establish an additional criterion, which pertains to the continuity of the thematic content across the segments of the fragments?? edge border that have been found to match with regard to shape. We first apply these criteria on the reconstruction of a commercial jigsaw puzzle in order to evaluate their performance. We then proceed to apply the criteria on several images of the Santorini fragments. For reasons of comparison, we also apply the color matching algorithms introduced by other researchers. Results show that in the presence of color deterioration and noise introduced by the passage of time and the fragmentation process, the combination of the information extracted from both the chromatic and the thematic content of the fragment images yields clearly superior results by those obtained from the use of chromatic information alone.     

Towards Novel Multifunctional Pillared Nanostructures: Effective Intercalation of Adamantylamine in Graphene Oxide and Smectite Clays

Multifunctional pillared materials are synthesized by the intercalation of cage‐shaped adamantylamine (ADMA) molecules into the interlayer space of graphite oxide (GO) and aluminosilicate clays. The physicochemical and structural properties of these hybrids, determined by X‐ray diffraction (XRD), Fourier transform infrared (FTIR), Raman and X‐ray photoemission (XPS) spectroscopies and transmission electron microscopy (TEM) show that they can serve as tunable hydrophobic/hydrophilic and stereospecific nanotemplates. Thus, in ADMA‐pillared clay hybrids, the phyllomorphous clay provides a hydrophilic nanoenvironment where the local hydrophobicity is modulated by the presence of ADMA moieties. On the other hand, in the ADMA‐GO hybrid, both the aromatic rings of GO sheets and the ADMA molecules define a hydrophobic nanoenvironment where sp³‐oxo moieties (epoxy, hydroxyl and carboxyl groups), present on GO, modulate hydrophilicity. As test applications, these pillared nanostructures are capable of selective/stereospecific trapping of small chlorophenols or can act as cytotoxic agents.     

Dynamic ventilation 3He MRI for the quantification of disease in the rat lung

Pulmonary diseases are known to be largely inhomogeneous. To evaluate such inhomogeneities, we are testing an image-based method to measure gas flow in the lung regionally. Dynamic, spin-density-weighted hyperpolarized (3)He MR images performed during slow inhalation of this gas were analyzed to quantify regional inflation rate. This parameter was measured in regions of interest (ROIs) that were defined by a rectangular grid that covered the entire rat lung and grew dynamically with it during its inflation. We used regional inflation rate to quantify elastase-induced emphysema and to differentiate healthy (n = 8) from elastase-treated (n = 9) rat lungs as well as healthy from elastase-treated areas of one rat unilaterally treated with elastase in the left lung. Emphysema was also assessed by gold standard morphological and well-established hyperpolarized (3)He MRI diffusion measurements. Mean values of regional inflation rates were significantly different for healthy and elastase-treated animals and correlated well with the apparent diffusion coefficient of (3)He and morphological measurements. The image-based biomarker inflation rate may be useful for the assessment of regional lung ventilation.     

XV. Yeast sequencing reports. A 29·425 kb segment on the left arm of yeast chromosome XV contains more than twice as many unknown as known open reading frames

The nucleotide sequence of a 29·425 kb fragment localized on the left arm of chromosome XV from Saccharomyces cerevisiae has been determined. The sequence contains 13 open reading frames (ORFs) of which four encode the known genes ADH1, COQ3, MSH2 and RCF4. Predictions are made concerning the functions of the unknown ORFs. Some of the ORFs contain sequences similar to expressed sequences tags (EST) found in the database made available by TIGR. In particular, the highly expressed ADH1 gene is represented in this database by no less than 20 EST sequences. Two ARS sequences and a putative functional GCN4 motif have also been detected. One ORF (O0953) containing nine putative transmembrane segments is similar to a hypothetical membrane protein of Arabidopsis thaliana. Characteristic features of the other ORFs include ATP/GTP binding sites, a fungal Zn(2)-Cys(6) binuclear centre, an endoplasmic reticulum targeting sequence, a β-transducin repeat signature and in two instances, good similarity to the prokaryotic lipoprotein signal peptide motif. The sequence has been deposited in the EMBL data library under Accession Number X83121.     

Trichodysplasia and amelogenesis imperfecta

A nonradioactive RNA-RNA in situ hybridization method using digoxigenin-labeled probes is described. The visualization of hybrids is done using the indoxyl-nitro blue tetrazolium alkaline phosphatase reaction. The addition of polyvinyl alcohols of high molecular weight (40-100 kDa) to the reaction medium enhances the alkaline phosphatase reaction and prevents diffusion of reaction intermediates, resulting in a 20-fold increase in sensitivity without increasing the background. Due to the more localized precipitation of the formazan, the site of hybridization can be determined more precisely.