Miracle-dz/UniFAR-FTUs huggingface dataset:
MAC Layer in Broadband PLC Networks-State of the Art , Solutions , and Modelling -

Broadband PLC systems, achieving data rates beyond 2 Mbps, which are applied to the low-voltage power supply networks to build up so-called PLC access networks, suppose to use a frequency spectrum up to 30MHz. However, the supply networks are not designed for communications and they act as antennas, producing electromagnetic radiation and causing disturbances to other telecommunications services which operate in this frequency range. Therefore, PLC networks have to operate with a limited signal power, which decreases data rates and makes PLC systems more sensitive to disturbances from the electrical power supply network, as well as from the network environment [1]. Well-known error handling mechanisms, such as Forward Error Correction (FEC), interleaving, and Automatic Repeat reQuest (ARQ) are applied to PLC systems to solve the problem of transmission errors [2]. However, application of these mechanisms consumes a part of the transmission capacity (due to coding overhead and data retransmissions) and further decreases the data rates. On the other hand, PLC networks have to provide a very good utilization of its shared transmission medium, keeping also a sufficient Quality of Service (QoS) for different telecommunications services. This is important because the broadband PLC access networks have to compete with other access technologies DSL and CATV. Both good network utilization and sufficient QoS can be achieved by using efficient methods for the network capacity sharing Medium Access Control (MAC) protocols. Nowadays, there are no existing standards or specifications considering physical and MAC layer for PLC access networks. The manufacturers of the PLC equipment developed proprietary solutions for the MAC layer incompatible to each other. In this paper, various implementation solutions for PLC MAC layer are considered; its general structure and specific requirements for PLC (Sec. 2), multiple access schemes (Sec. 3), an analysis of suitable MAC protocols for PLC (Sec. 4), a brief consideration of traffic control mechanisms including duplex mode, and presentation of a modeling approach for investigations of the PLC MAC layer and its protocols. 2. Structure of the MAC Layer
Agent-based models of the labor market

We review the literature on agent-based labor market models by tracing its roots to the microsimulation literature, and surveying a selection of contributions made since the work by Bergmann (1974) and Eliasson (1976). Agent-based models have been applied to explain stylized facts of labor markets as well as for labor market policy evaluations. They also constitute a major part in agent-based macroeconomic models. Besides reviewing the various results achieved, we discuss modeling choices with respect to agents’ behavior and the structure of interaction. Our overall assessment is that agent-based labor market models have given us valuable insights into the functioning of labor markets and the consequences of labor market policies, and that they will increasingly become an essential tool of analysis, in particular when the construction of large macro-models is involved.
Design and evaluation of photometric image quality measures for effective face recognition

The performance of an automated face recognition system can be significantly influenced by face image quality. Designing effective image quality index is necessary in order to provide real-time feedback for reducing the number of poor quality face images acquired during enrollment and authentication, thereby improving matching performance. In this study, the authors first evaluate techniques that can measure image quality factors such as contrast, brightness, sharpness, focus and illumination in the context of face recognition. Second, they determine whether using a combination of techniques for measuring each quality factor is more beneficial, in terms of face recognition performance, than using a single independent technique. Third, they propose a new face image quality index (FQI) that combines multiple quality measures, and classifies a face image based on this index. In the author's studies, they evaluate the benefit of using FQI as an alternative index to independent measures. Finally, they conduct statistical significance Z-tests that demonstrate the advantages of the proposed FQI in face recognition applications.
The structure of postsynaptic densities isolated from dog cerebral cortex: I. overall morphology and protein composition

A postsynaptic density (PSD) fraction, including some adherent subsynaptic web material, has been isolated from dog cerebral cortex by a short-procedure modification of methods of Davis and Bloom (21, 22) and Cotman and Taylor (20), using Triton X-100. The fraction has been visualized by thin-section, replica, and negative (phosphotungstic acid) staining electron microscopy and its proteins separated by high-resoltuion SDS gel electrophoresis. Morphologically, the preparation seems to be quite pure, with very little membrane contamination. The density is composed of protein, no nuclei acids, and very little phospholipids being detectable. The fraction had no ATPase or GTPase activity, but it did have a very small amount of cytochrome c oxidase activity (of a specific activity less than 0.5 percent that of a mitochondrial fraction) and a small amount of 5'- nucleotidase activity (of a specific activity between 6 and 7 percent that of a synaptic membrane fraction). Electron micrographs reveal cup-shaped structures approximately 400nm long and approximately 40nm wide, made up of apparent particles 13-28nm in diameter. However, en face views, and particularly micrographs of replicas and PTA-stained preparations, reveal a disk-shaped structure, outside diameter approximately 400 nm, in which filaments are seen to extend from the central part of the density. High resolution gel electrophoresis studies indicated some 15 major proteins and perhaps 10 or more minor ones; the predominant protein had a mol wt of 51,000, followed by ones at 45,000, 40,000, 31,000, 26,000, and several at 100,000. A comparison by gel electrophoresis of density fraction proteins with those of a lysed synaptosomal membrane fraction containing some adherent densities indicated some comigrating proteins, but the major membrane fraction protein, mol wt 52,000, was not found in the density fraction. Antibodies raised against the density fraction reacted with a preparation of solubilized synaptic membrane proteins. By both these criteria, it was considered that the density and the synaptic membrane have some proteins in common. By separately mixing (125)I-labeled myelin, synaptic vesicle, and mitochondrial fraction proteins with synaptosomes, and then isolating the density fraction from the mixture, it was concluded that a major 26,000 mol wt density fraction protein was common to both mitochondria and density, that none of the proteins of the density were contaminants from the mitochondrial fraction, that a minor approximately 150,000 band was a contaminant from the synaptic vesicle fraction, and that the moderately staining PSD fraction protein of 17,000 mol wt band was the result of contamination by the major basic protein of myelin. On the basis of the marker enzymatic assays and the mixing experiments, it is considered that the density fraction is moderately pure biochemically, and that its protein composition, aside from a few exceptions noted above, reflects its in situ character.
3D weather radar image compression using multiscale recurrent patterns

In this work we use the multidimensional multiscale parser (MMP) algorithm to compress three-dimensional data from weather radar. MMP is based on approximate multiscale pattern matching. MMP encodes segments of an input signal using expanded and contracted versions of patterns stored in a dictionary. The dictionary is updated using concatenated and displaced versions of previously encoded segments, therefore MMP builds its own dictionary while the input data is being encoded. MMP can be adapted to compress signals of any number of dimensions, and has been successfully applied to compress two-dimensional image data and one-dimensional ECG and EMG signals. We show simulation results where our 3D version of MMP outperforms some of the best encoders in the literature.
Simulation studies of a phosphor-free monolithic multi-wavelength light-emitting diode

A monolithic multi-wavelength light emitting diode structure is presented in this paper. The structure is based on two InGaN quantum wells separated by a GaN barrier layer. This structure allows the full activation of each quantum well separately as well as simultaneously with the tuning of applied voltage. Consequently, blue to green color emissions can be generated by tuning the forward bias voltage. The technique of band gap engineering has been deployed to reduce the photon reabsorption hence improving the output power of the device. Dimensions and indium contents of the quantum wells are optimized to enhance the radiative recombination rate and reduce the phonon emission. This paper investigates the carrier distribution profile, IV characteristics, luminous power, radiative recombination rate, conversion efficiency, and spectral power distribution of multi-color light emitting diode.
Studies of Aggregation Pathways for Amyloidogenic Peptides by Dielectric Relaxation Spectroscopy

Diseases associated with amyloid aggregation have been a growing focus of medical research in recent years. Altered conformations of amyloidogenic peptides assemble to form soluble aggregates that deposit into the brain and spleen causing disorders such as Alzheimer’s disease and Type II diabetes. Emergent theories predict that fibrils may not be the toxic form of amyloidogenic structures and that smaller oligomer and protofibril aggregates may be the primary source of cellular function damage. Studies show that these amyloidogenic aggregates are characterized by an increased number of poorly dehydrated hydrogen backbones and large surface densities of patches of bulk like water which favor protein association. When proteins aggregate to form larger structures, there is a redistribution of water surrounding these proteins. The water dynamics of amyloidogenic aggregation is different than the monomeric form and has a decrease in the number of patches occupied by molecules with bulk-like water behavior. We demonstrate that the redistribution of water during amyloid aggregation is reflected in a change in the dielectric relaxation signal of protein-solvent mixtures. We use dielectric relaxation spectroscopy (DRS) as a tool for studying the dynamics of amyloidogenic peptides—amyloid beta (Aβ1−42) and human islet amyloid polypeptide (hIAPP)—during self-assembly and aggregation. Non-amyloidogenic analogs—scrambled Aβ42−1 and rat islet amyloid polypeptide (rIAPP)—were used as controls. We first present studies of amyloidogenic peptides in a deionized water buffer at room temperature as a function of concentration and incubation time. From this we were able to determine differences in amyloidogenic and non-amyloidogenic peptides through the dielectric modulus. We next present the same analytes in a deionized water-glycerol buffer to facilitate the study of the dielectric permittivity at sub-freezing temperatures and model the kinetics of the α-and β-relaxation processes. We conclude our work by studying the peptides in a bovine serum albumin iii (BSA) and glycerol buffer to demonstrate dielectric spectroscopy as a sensitive tool for measuring amyloidogenic peptides in an in vivo-like condition.
Taphonomic bias and time-averaging in tropical molluscan death assemblages: differential shell half-lives in Great Barrier Reef sediment

Abstract Radiocarbon-calibrated amino acid racemization ages of 428 individually dated shells representing four molluscan taxa are used to quantify time-averaging and shell half-lives with increasing burial depth in the shallow-water carbonate lagoon of Rib Reef, central Great Barrier Reef, Australia. The top 20 cm of sediment contains a distinct, essentially modern assemblage. Shells recovered at depths from 25 to 125 cm are age-homogeneous and significantly older than the surface layer. Taxon age distributions within sedimentary layers indicate that the top 125 cm of lagoonal sediment is thoroughly mixed on a sub-century scale. The age distributions and shell half-lives of four taxa (Ethalia, Natica, Tellina, and Turbo) are found to be largely distinct. Shell half-lives do not coincide with any single morphological characteristic thought to infer greater durability, but they are strongly related to a combined durability score based on shell density, thickness, and shape. These results illustrate the importance of bioturbation in tropical sedimentary environments, indicate that age estimates in this depositional setting are sensitive to taxon choice, and quantify a taxon-dependent bias in shell longevity and death assemblage formation.
Objects and Events in the Attentional Blink

When two visual targets, T1 and T2, are presented in rapid succession, detection or identification of T2 is almost universally degraded by the requirement to attend to T1 (the attentional blink, or AB). One interesting exception occurs when T1 is a brief gap in a continuous letter stream and the task is to discriminate its duration. One hypothesized explanation for this exception is that an AB is triggered only by attention to a patterned object. The results reported here eliminate this hypothesis. Duration judgments produced no AB whether the judged duration concerned a short gap in the letter stream (Experiment 1) or a letter presented for slightly longer than others (Experiment 2). When identification of an identical longer letter T1 was required (Experiment 3), rather than a duration judgment, the AB was reestablished. Direct perceptual judgments of letter streams with gaps embedded showed that whereas brief gaps result in the percept of a single, briefly hesitating stream, longer gaps result in the percept of two separate streams with a separating pause. Correspondingly, an AB was produced in Experiment 4, when participants were required to judge the duration of longer T1 gaps. We propose that, like spatially separated objects, temporal events are parsed into discrete, hierarchically organized events. An AB is triggered only when a new attended event is defined, either when a long pause creates a new perceived stream (Experiment 4) or when attention shifts from the stream to the letter level (Experiment 3).
Expression of cloned rpoB gene of Escherichia coli: a genetic system for the isolation of dominant negative mutations and overproduction of defective beta subunit of RNA polymerase

The rifampin resistance rifD18 allele of rpoB, carried on the expression plasmid pXT7 beta, is controlled by a strong bacteriophage T7 late promoter and two weak Escherichia coli promoters. Depending on the host strain, pXT7 beta specifies different levels of Rifr beta subunit, providing a system for the isolation, maintenance, and overexpression of dominant lethal alleles of rpoB. In rpoB+ hosts, pXT7 beta confers the Rifr phenotype on the Rifs host. Negative rpoB mutations in the plasmid DNA can thus be scored by screening transformants for Rifs. In an rpoB(Am) supD(Ts) host in which chromosomal rpoB expression is decreased as the temperature goes up, some of the negative plasmid-borne rpoB mutations displayed a dominant phenotype. In a host harboring inducible T7 RNA polymerase, the defective beta subunits could be overexpressed independently of the E. coli transcriptional machinery. With this system, we isolated several negative rpoB mutations induced in vitro by hydroxylamine. Seven of the mutant rpoB alleles, when overexpressed, were found to specify normal-size beta polypeptides. Two of them displayed the dominant lethal phenotype in the rpoB(Am) supD(Ts) background. We also constructed a mutation (rpoB1800) in which 24 carboxy-terminal amino acids were substituted with a random 19-amino-acid sequence. The nonfunctional rpoB1800 beta polypeptide was isolated and assembled in vitro into the core enzyme molecule.
Who You Know vs. What You Know: The Impact of Social Position and Knowledge on Team Performance

ABSTRACT Organizational behavior theories generally agree that human capital is critical to teams and organizations, but little guidance exists on the extent to which such theories accurately explain the relative contributions of individual actors to overall performance. Using newly created network measures and simulations based on data obtained from a software development firm, we investigate the relative effectiveness of social network theory and resource dependency theory as predictors of individuals' contributions to team performance. Our results indicate that individual impacts on team performance are more closely associated with knowledge and task dimensions than with social network structure. Furthermore, given that knowledge may be assessed a priori, these factors provide useful guidance for structuring teams and predicting team performance.
Suppression of Lymphocyte Functions by Plasma Exosomes Correlates with Disease Activity in Patients with Head and Neck Cancer

Purpose: Head and neck cancers (HNCs) often induce profound immunosuppression, which contributes to disease progression and interferes with immune-based therapies. Body fluids of patients with HNC are enriched in exosomes potentially engaged in negative regulation of antitumor immune responses. The presence and content of exosomes derived from plasma of patients with HNC are evaluated for the ability to induce immune dysfunction and influence disease activity. Experimental Design: Exosomes were isolated by size-exclusion chromatography from plasma of 38 patients with HNC and 14 healthy donors. Morphology, size, numbers, and protein and molecular contents of the recovered exosomes were determined. Coculture assays were performed to measure exosome-mediated effects on functions of normal human lymphocyte subsets and natural killer (NK) cells. The results were correlated with disease stage and activity. Results: The presence, quantity, and molecular content of isolated, plasma-derived exosomes discriminated patients with HNC with active disease (AD) from those with no evident disease (NED) after oncologic therapies. Exosomes of patients with AD were significantly more effective than exosomes of patients with NED in inducing apoptosis of CD8+ T cells, suppression of CD4+ T-cell proliferation, and upregulation of regulatory T-cell (Treg) suppressor functions (all at P < 0.05). Exosomes of patients with AD also downregulated NKG2D expression levels in NK cells. Conclusions: Exosomes in plasma of patients with HNC carry immunosuppressive molecules and interfere with functions of immune cells. Exosome-induced immune suppression correlates with disease activity in HNC, suggesting that plasma exosomes could be useful as biomarkers of HNC progression. Clin Cancer Res; 23(16); 4843–54. ©2017 AACR.
Mining nearness relations from an n-grams Web corpus in geographical space

Interacting with spatial data effectively requires systems that not only process references to locations, but understand spatial natural language. Empirical research has demonstrated that near is vague, asymmetric and context dependent. We explore near in language using Microsoft Web n-grams for expressions of the form A near*, where A are placenames referring to different spatial granularities, ranging from points of interest to large U.S. cities and * are autocomplete suggestions for placenames. Analyzing the extracted expressions requires consideration of semantic and referent ambiguity. With more than 200,000 expressions we show not only what is considered to be near at different scales, but also produce intuitive maps of nearness for different locations.
Successful Implementation of eRx Systems: Creating Technology–Organization Alignment using the Strategy-Map Approach

The adoption rates of eRx systems continue to be low and their implementation remains uneven. Rooted in the theories of technology–organization alignment and strategy maps, this article develops a framework for successful implementation of eRx systems. The proposed strategy map outlines the key strategic processes that would make implementation of eRx systems not only feasible and successful, but also a profitable venture for healthcare organizations.
Minimizing the carbon emissions on road networks

The models and algorithms developed for transportation planning, vehicle routing, path finding and the software that utilize them are usually based on distance and constant travel times between the relevant locations and aim at minimizing total distance or travel time . However, constant travel time assumption is not realistic on road networks as the traffic conditions may vary from morning/evening rush hours to off-peak noon/night hours, from the weekends to business days, even from one season to another. Thus, distance/time based optimization does not exactly reflect the real fuel consumptions, hence the actual costs; neither can they be used to accurately account for the greenhouse gas (GHG) emissions. A distance/constant time based optimization model may even yield an infeasible solution when time-windows exist or the route length is time limited. In this study, we first analyze the peculiar characteristics of the Greenest Path Problem (GPP) where the objective is to find the least GHG generating path from an origin to a destination on the road network. We then propose a fast heuristic method for determining the greenest path, by incorporating fuel consumption and GHG emission objectives. Finally, we integrate the proposed algorithm into the Green Vehicle Routing Problem that minimizes the GHG emissions rather than the total distance or travel time. The developed heuristic is benchmarked against the existing algorithms by using synthetic traffic data on a real road network to illustrate potential savings and sustainability benefits.
Fiber Tract Following in the Human Brain Using DT-MRI Data

In Vivo Diffusion Tensor Magnetic Resonance Imaging (DT-MRI) can now be used to elucidate and investigate major nerve pathways in the brain. Nerve pathways are constructed by a) calculating a continuous diffusion tensor field from the discrete, noisy, measured DT-MRI data and then b) solving an equation describing the evolution of a fiber tract, in which the local direction vector of the trajectory is identified with the direction of maximum apparent diffusivity. This approach has been validated previously using synthesized, noisy DT-MRI data. Presently, it is possible to reconstruct large white matter structures in the brain, such as the corpus callosum and the pyramidal tracts. Several problems, however, still affect the method’s reliability. Its accuracy degrades where the fiber-tract directional distribution is non-uniform, and background noise in diffusion weighted MRIs can cause computed trajectories to jump to different tracts. Nonetheless, this method can provide quantitative information with which to visualize and study connectivity and continuity of neural pathways in the central and peripheral nervous systems in vivo, and holds promise for elucidating architectural features in other fibrous tissues and ordered media. key words: MRI, DTI, DT, diffusion, tensor, human, brain, white matter, fiber, tract, trajectory, artifact, noise