On lossy transmission of correlated sources over a multiple access channel

We study lossy communication of correlated sources over a multiple access channel. In particular, we provide a joint source-channel coding scheme for transmitting correlated sources with decoder side information, and study the conditions under which separate source and channel coding is optimal. For the latter, the encoders and/or the decoder have access to a common observation conditioned on which the two sources are independent. By establishing necessary and sufficient conditions, we show the optimality of separation when the encoders and the decoder both have access to the common observation. We also demonstrate that separation is optimal when only the encoders have access to the common observation whose lossless recovery is required at the decoder. As a special case, we study separation for sources with a common part. Our results indicate that side information can have significant impact on the optimality of source-channel separation in lossy transmission

Cooperative effect of heparan sulfate and laminin mimetic peptide nanofibers on the promotion of neurite outgrowth

Cataloged from PDF version of article.Extracellular matrix contains an abundant variety of signals that are received by cell surface receptors contributing to cell fate, via regulation of cellular activities such as proliferation, migration and differentiation. Cues from extracellular matrix can be used for the development of materials to direct cells into their desired fate. Neural extracellular matrix (ECM) is rich in axonal growth inducer proteins, and by mimicking these permissive elements in the cellular environment, neural differentiation as well as neurite outgrowth can be induced. In this paper, we used a synthetic peptide nanofiber system that can mimic not only the activity of laminin, an axonal growth-promoting constituent of the neural ECM, but also the activity of heparan sulfate proteoglycans in order to induce neuritogenesis. Heparan sulfate mimetic groups that were utilized in our system have an affinity to growth factors and induce the neuroregenerative effect of laminin mimetic peptide nanofibers. The self-assembled peptide nanofibers with heparan sulfate mimetic and laminin-derived epitopes significantly promoted neurite outgrowth by PC-12 cells. In addition, these scaffolds were even effective in the presence of chondroitin sulfate proteoglycans (CSPGs), which are the major inhibitory components of the central nervous system. In the presence of these nanofibers, cells could overcome CSPG inhibitory effect and extend neurites on peptide nanofiber scaffolds. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Rigidity of Linearly Constrained Frameworks

We consider the problem of characterising the generic rigidity of bar-joint frameworks in R d in which each vertex is constrained to lie in a given affine subspace. The special case when d = 2 was previously solved by I. Streinu and L. Theran in 2010. We will extend their characterisation to the case when d ≥ 3 and each vertex is constrained to lie in an affine subspace of dimension t, when t = 1, 2 and also when t ≥ 3 and d ≥ t(t−1). We then point out that results on body-bar frameworks obtained by N. Katoh and S. Tanigawa in 2013 can be used to characterise when a graph has a rigid realisation as a d-dimensional body-bar framework with a given set of linear constraints

Highly senstivive determination of 2.4,6-Trinitrotolunene and Related Byproducts Using a Diol Functionalized Column for High Performance Liquid Chromatography

Cataloged from PDF version of article.In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT); 2,4-dinitrotoluene (2,4-DNT); 2,6-dinitrotoluene (2,6-DNT); 2-aminodinitrotoluene (2-ADNT) and 4-aminodinitrotoluene (4-ADNT) molecules in high-performance liquid-chromatography (HPLC) with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95-98%. The detection limits for diol column ranged from 0.78 to 1.17 μg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation. © 2014 Gumuscu et al

Electrostatic effects on nanofiber formation of self-assembling peptide amphiphiles

Cataloged from PDF version of article.Self-assembling peptide amphiphile molecules have been of interest to various tissue engineering studies. These molecules self-assemble into nanofibers which organize into three-dimensional networks to form hydrocolloid systems mimicking the extracellular matrix. The formation of nanofibers is affected by the electrostatic interactions among the peptides. In this work, we studied the effect of charged groups on the peptides on nanofiber formation. The self-assembly process was studied by pH and zeta potential measurements, FT-IR, circular dichroism, rheology, atomic force microscopy, scanning electron microscopy and transmission electron microscopy. The aggregation of the peptides was triggered upon neutralization of the charged residues by pH change or addition of electrolyte or biomacromolecules. Understanding the controlled formation of the hydrocolloid gels composed of peptide amphiphile nanofibers can lead us to develop in situ gel forming bioactive collagen mimetic nanofibers for various tissue engineering studies including bioactive surface coatings. (C) 2010 Elsevier Inc. All rights reserved

Heparin Mimetic Peptide Nanofibers Promote Angiogenesis

Cataloged from PDF version of article.New blood vessel formation (angiogenesis) is one of the most important processes required for functional tissue formation. Induction of angiogenesis is usually triggered by growth factors released by cells. Glycosaminoglycans (e.g., heparan sulphates) in the extracellular matrix aid in proper functioning of these growth factors. Therefore, exogeneous heparin or growth factors were required for promoting angiogenesis in previous regenerative medicine studies. Here we report for the first time induction of angiogenesis by a synthetic nanofibrous peptide scaffold without the addition of any exogenous growth factors or heparin. We designed and synthesized a self-assembling peptide amphiphile molecule that is functionalized with biologically active groups to mimic heparin. Like heparin, this molecule has the ability to interact with growth factors and effectively enhance their bioactivity. The nanofibers formed by these molecules were shown to form a 3D network mimicking the structural proteins in the extracellular matrix. Because of heparin mimicking capabilities of the peptide nanofibers, angiogenesis was induced without the addition of exogenous growth factors in vitro. Bioactive interactions between the nanofibers and the growth factors enabled robust vascularization in vivo as well. Heparin mimetic peptide nanofibers presented here provide new opportunities for angiogenesis and tissue regeneration by avoiding the use of heparin and exogenous growth factors. The synthetic peptide nanofiber scaffolds enriched with proper chemical functional groups shown in this study can be used to induce various desired physiological responses for tissue regeneration. © 2011 American Chemical Society

Oligonucleotide delivery with cell surface binding and cell penetrating peptide amphiphile nanospheres

Cataloged from PDF version of article.A drug delivery system designed specifically for oligonucleotide therapeutics can ameliorate the problems associated with the in vivo delivery of these molecules. The internalization of free oligonudeotides is challenging, and cytotoxicity is the main obstacle for current transfection vehicles. To develop nontoxic delivery vehicles for efficient transfection of oligonudeotides, we designed a self-assembling peptide amphiphile (PA) nanosphere delivery system decorated with cell penetrating peptides (CPPs) containing multiple arginine residues (R-4 and R-8), and a cell surface binding peptide (KRSR), and report the efficiency of this system in delivering G-3129, a Bcl-2 antisense oligonucleotide (AON). PA/AON (peptide amphiphile/antisense oligonucleotide) complexes were characterized with regards to their size and secondary structure, and their cellular internalization efficiencies were evaluated. The effect of the number of arginine residues on the cellular internalization was investigated by both flow cytometry and confocal imaging, and the results revealed that uptake efficiency improved as the number of arginines in the sequence increased. The combined effect of cell penetration and surface binding property on the cellular internalization and its uptake mechanism was also evaluated by mixing R-8-PA and KRSR-PA. R-8 and R-8/KRSR decorated PAs were found to drastically increase the internalization of AONs compared to nonbioactive PA control. Overall, the KRSR-decorated self-assembled PA nanospheres were demonstrated to be noncytotoxic delivery vectors with high transfection rates and may serve as a promising delivery system for AONs

Is there a flight to quality due to inflation uncertainty?

After two types of inflation uncertainty are derived within a time-varying parameter model with GARCH specification, the relationship between inflation uncertainty and interest rates for safe assets is investigated. The results support the existence of a "flight to quality" effect. © 2004 Elsevier B.V. All rights reserved

A retrospective evaluation of traumatic dental injury in children who applied to the dental hospital, Turkey

Objective: The purpose of this study was to analyze traumatic dental injuries in children visiting the dental hospital emergency department in Samsun of Turkey, in the period from 2007 to 2011.Materials and Methods: Data of age, gender, causes of dental trauma, injured teeth, type of dental injuries, the application period, the dental treatments, and traumatic dental injuries according to the seasons were obtained from the records at dental hospital.Results: Of all 320 patients with traumatic dental injury, 205 were boys and 115 were girls with a boys/girls ratio 1.78:1. Traumatic dental injury was observed more frequently in the 7.12 age groups: 52.5% in girls and 67.8% in boys. Falls are the major cause of traumatic dental injury in the age group 6.12 (51.4%). Sport activities are a common cause of traumatic dental injury in the 7.12 age group (34.2%). Patients visited a dentist within approximately 2 h (57.1%). The upper anterior teeth were subjected to trauma more frequently than the lower anterior teeth. The maxillary central incisors were the most commonly affected teeth, and the  mandibular canins were the least affected teeth. In primary teeth, avulsion was the most common type of dental injury (23%); on the other hand, enamel fractures were the most common type of dental injury (30.6%) observed in permanent teeth. In the primary dentition, the most commonly performed treatments were dental examination and prescribing (70%). The most common treatment choices in permanent teeth were restoration and dental examination (49.7 and 15.8%, respectively).Conclusion: The results of the study show that the emergency intervention to traumatized teeth is important for good prognosis of teeth and oral tissues. Therefore, the parents should be informed about dental trauma in schools, and dental hospital physicians should be subjected to postgraduate training.Key words: Classification, emergency treatment, teeth, traum