bluuebunny/crossref_metadata_2025 huggingface dataset:
Expectation maximization joint channel impulse response and dynamic parameter estimation and its impact on adaptive equalization
Authors: Li Weichang , Preisig James C.
Published: October 2013

Joint estimation of channel impulse response and its dynamic parameters using the expectation maximization (EM) algorithm and its MAP variant is derived for broadband shallow-water acoustic communication channels. Based on state-space channel modeling, the EM algorithms estimate the channel dynamic parameters from the sequence of channel impulse response estimates. The estimated parameters are then used in the Kalman smoother, which estimates the channel impulse response. The stability of the algorithm is shown to be related to an extended persistent excitation (EPE) condition, which requires that both the symbol sequence and the channel estimates be persistently exciting. Modified algorithms are proposed for broadband multipath channels to avoid the issue of insufficient excitation. Efficient suboptimal algorithms are also derived from the EM algorithms that alternatively estimate the parameter and the channel impulse response while allowing slow parameter variations. The performance of these channel estimation algorithms as well as their impact on the subsequent equalizer are demonstrated through experimental data analysis. [Work supported by ONR Ocean Acoustics.]
Automatic detection performance comparisons of three different fluctuation-based signal processors
Authors: Wagstaff Ronald A.
Published: October 2013

The three most common fluctuation-based signal processor (FBP) algorithms achieve gain by exploiting either the reciprocal of the spectral amplitude, the log-differential amplitude, or aligned-phase angles. Two important features of these processors, for the underwater acoustics community, is their ability to detect and automatically identify signals which originated from submerged sources, and to provide unusually large signal-to-noise ratio gains. Similar benefits are of interest to the atmosphere acoustic community. An example is the automatic detection and identification/classification of hostile airborne and ground vehicles by unattended ground sensors (UGS). The three different generic types of FBP algorithms will be defined. The manner in which each exploits fluctuations to achieve gain will be explained. Corresponding performances will be compared using both underwater and atmosphere acoustic data. The ocean acoustic results came from towed array beamformed spectral data and will include spectral plots and grams. Corresponding single sensor spectral results will also be presented for atmosphere acoustic vehicle data. [Work supported by ARDEC and SMDC.]
The estimated ocean detector: Predicted performance for continuous time signals in a random/uncertain ocean
Authors: Ballard Jeffrey A. , Culver R. Lee , Sibul Leon H. , Jemmott Colin W. , Camin H. John
Published: October 2013

This paper addresses implementation of the maximum likelihood (ML) detector for passive SONAR detection of continuous time stochastic signals that have propagated through a random or uncertain ocean. We have shown previously that Monte Carlo simulation and the maximum entropy method can make use of knowledge of environmental variability to construct signal and noise parameter probability density functions (pdf’s) belonging to the exponential class. For these cases, the ML detector has an estimator-correlator and noise-canceller implementation. The estimator-correlator detector computes the conditional mean estimate of the signal conditioned on the received data and correlates it with a function of the received data, hence the name estimated ocean detector (EOD). Here we derive the detector structure for continuous time stochastic signals and Gaussian noise and present receiver operating characteristic (ROC) curves for the detector as a function of the signal-to-noise ratio. [Work supported by ONR Undersea Signal Processing Code 321US.]
Phenomenon of Leonid Maximovich Brekhovskikh as a man and a scientist
Authors: Dubrovskiy Nikolay
Published: October 2013

Leonid Maximovich Brekhovskikh made phenomenal contributions in acoustics: discovery of the underwater sound channel, development of the fundamental theory of wave propagation in layered media, and working out a tangent plane approximation in the wave scattering theory. Brekhovskikh contributed greatly to the organization of research teams and the dissemination of information on acoustics and oceanography through his popular books and lecturing. He also made a major breakthrough as a public figure and a statesman. He became the first Director of the Acoustics Institute at the age of 36. He served as a secretary of the Russian Academy of Sciences Branch involved in oceanography, geography, and atmospheric physics research. Brekhovskikh’s achievements in science and science leadership were marked by multiple highest USSR awards and many international awards. He became an Honorary Fellow of the Acoustical Society of America and the Russian Acoustical Society. He received the Lord Raleigh Medal for the discovery that preserved its urgency for 30 years. Brekhovskikh’s phenomenon is regarded here from the viewpoint of his personality as well as specific circumstances of his family and social life.
Some aspects of Leonid Brekhovskikh’s influence on oceanographic acoustics
Authors: Kuperman W. A. , Munk W.
Published: October 2013

Waveguide physics describes the basic features of long-range sound propagation in the ocean. Over the last half century the theory has progressed from describing ideal waveguides to more complicated layered structures to range-dependent structures to time-varying, range-dependent structures. The theme of Brekhovskikh’s pioneering work was the development of robust formulations that permitted understanding basic ocean acoustics while also laying the foundation to progress to the next levels of realistic complexity. Early on, he realized that acoustic data were not consistent with known oceanography. His seminal oceanographic experiments established the pervasive presence of mesoscale phenomena, which to this day are still not fully incorporated into rigorous formulations of the forward and inverse acoustics problems. We discuss only a very small part of his work and its subsequent influence.
Underwater sound propagation: 49 years with L. M. Brekhovskikh’s Waves in Layered Media
Authors: Godin Oleg A.
Published: October 2013

In his first 10 years of research on wave propagation in layered media, L. M. Brekhovskikh created a theory that remains a basis for physical understanding and mathematical modeling of underwater sound propagation. Summarized in his celebrated book Waves in Layered Media, first published in 1957, the theory includes spectral (quasi-plane wave) representations of wave fields, normal mode theory for open waveguides, extensions of the ray and WKBJ methods, and a clear treatment of diffraction phenomena attendant to caustics, lateral waves, and reflection of wave beams and pulses. The book also charted the ways forward that have been and are followed by numerous researchers around the globe. Some of the resulting progress was documented in subsequent editions of Waves in Layered Media and in later books L. M. Brekhovskikh coauthored with his students. This paper will discuss diverse, groundbreaking contributions L. M. Brekhovskikh made to the wave propagation theory from the prospective offered by recent developments in underwater acoustics.
Assessment of reverberation time in halls through analysis of running music
Authors: Conant David
Published: October 2013

The source signal to excite a room’s reverberant field sufficient for detailed measurement of reverberation time (RT60) and other measures has been the subject of considerable investigation over several decades. It is generally acknowledged that the best sources are (depending on the researcher) swept tones, MLS, MLS variations, stopped noise, cannon shots, etc. All can be characterized as highly audience unfriendly. In the interest of obtaining useful approximations of measured midfrequency RT60 in the presence of live audiences, this paper discusses several approaches that may be fruitful while being entirely unobtrusive to the concert experience.
Room volume estimation from diffuse field theory
Authors: Kuster Martin , van Walstijn Maarten
Published: October 2013

Among the parameters relevant in room acoustics, the room volume is one of the most important. The general course in room acoustics research is to use the room volume in the prediction of room acoustic parameters such as reverberation time or total relative sound pressure level. Contrary to this, it has been investigated to what extent the room volume can be retrieved from a measured room impulse response. The approach followed is based on room acoustic diffuse field theory and requires correctly measured room impulse responses with the initial time delay corresponding to the source to receiver distance. A total of ten rooms of varying size and acoustic characteristics have been included. The results in three rooms were unreliable, which was explained by the particular acoustic characteristics. In the remaining rooms the results were numerically useful and consistent between different positions within the same room (relative standard deviation around 20%). The influence of source and receiver directivity is also considered.
Virtual microphone control: A comparison of measured to created impulse responses of various microphone techniques
Authors: Valente Daniel , Braasch Jonas
Published: October 2013

A method of rendering sound sources in 3-D space has been developed using virtual microphone control (ViMiC) [J. Acoust. Soc. Am. 117, 2391]. This method has been used to create a flexible architecture for the creation and rendering of a virtual auditory environment based on microphone techniques. One of the advantages of ViMiC is the ability to simulate coincident, near-coincident, and spaced microphone recording techniques. This allows the user active spatial control over the recorded environment and the ability to shape the final rendering based on his or her specific auditory needs. In order to determine the accuracy of simulating the virtual microphone techniques, measurements of several acoustic spaces in Troy, NY will be compared to the measurements of generated impulse responses of the same modeled spaces within the ViMiC environment. The data from the measured impulse responses will be used to adapt the ViMiC system in order to create a more realistic auditory rendering. Moreover, the ViMiC system can be improved for use as an educational tool for teaching recording engineers to hear the subtle differences between various microphone techniques.
Structural and Functional Brain Networks: From Connections to Cognition
Authors: Park Hae-Jeong , Friston Karl
Published: October 2013

How rich functionality emerges from the invariant structural architecture of the brain remains a major mystery in neuroscience. Recent applications of network theory and theoretical neuroscience to large-scale brain networks have started to dissolve this mystery. Network analyses suggest that hierarchical modular brain networks are particularly suited to facilitate local (segregated) neuronal operations and the global integration of segregated functions. Although functional networks are constrained by structural connections, context-sensitive integration during cognition tasks necessarily entails a divergence between structural and functional networks. This degenerate (many-to-one) function-structure mapping is crucial for understanding the nature of brain networks. The emergence of dynamic functional networks from static structural connections calls for a formal (computational) approach to neuronal information processing that may resolve this dialectic between structure and function.
Predispositions and Plasticity in Music and Speech Learning: Neural Correlates and Implications
Authors: Zatorre Robert J.
Published: October 2013

Speech and music are remarkable aspects of human cognition and sensory-motor processing. Cognitive neuroscience has focused on them to understand how brain function and structure are modified by learning. Recent evidence indicates that individual differences in anatomical and functional properties of the neural architecture also affect learning and performance in these domains. Here, neuroimaging findings are reviewed that reiterate evidence of experience-dependent brain plasticity, but also point to the predictive validity of such data in relation to new learning in speech and music domains. Indices of neural sensitivity to certain stimulus features have been shown to predict individual rates of learning; individual network properties of brain activity are especially relevant in this regard, as they may reflect anatomical connectivity. Similarly, numerous studies have shown that anatomical features of auditory cortex and other structures, and their anatomical connectivity, are predictive of new sensory-motor learning ability. Implications of this growing body of literature are discussed.
Resident Neural Stem Cells Restrict Tissue Damage and Neuronal Loss After Spinal Cord Injury in Mice
Authors: Sabelström Hanna , Stenudd Moa , Réu Pedro , Dias David O. , Elfineh Marta , Zdunek Sofia , Damberg Peter , Göritz Christian , Frisén Jonas
Published: October 2013

The Good Scar

We tend to think of scars as bad and, in the central nervous system, as counterproductive to recovery. Studying mice,

Sabelström
et al.

(p.
637
) prevented resident stem cells from proliferating after spinal cord injury. Without the astrocytes generated by the neural stem cells, recovery from spinal cord lesions was poorer than normal. Thus, somewhat counterintuitively, glial scarring appears to limit spinal cord damage and support the remaining cells.
Evolution of the Magnetic Field Structure of the Crab Pulsar
Authors: Lyne Andrew , Graham-Smith Francis , Weltevrede Patrick , Jordan Christine , Stappers Ben , Bassa Cees , Kramer Michael
Published: October 2013

Magnetic Crab

Since pulsars—highly magnetized rotating neutron stars—were discovered 45 years ago, the evolution of their magnetic field structure has been subject to much theoretical conjecture. However, observational evidence has been sparse. Now

Lyne
et al.

(p.
598
) report high-precision measurements, spanning more than two decades, that reveal the systematic evolution of the radiation pattern of the pulsar in the Crab Nebula, one of the youngest neutron stars known.
An Ethnographic Check-Up
When People Come First
Critical Studies in Global Health

João Biehl and Adriana Petryna, Eds.

Princeton University Press, Princeton, NJ, 2013. 454 pp. $75, £52. ISBN 9780691157382. Paper, $29.95, £19.95. ISBN 9780691157399.
Authors: Berry Nicole S.
Published: October 2013

This "ethnographic critique of the contemporary global health enterprise" comprises contributions from anthropologists, historians, an epidemiologist, and a human rights scholar.
Reconstructing the Microbial Diversity and Function of Pre-Agricultural Tallgrass Prairie Soils in the United States
Authors: Fierer Noah , Ladau Joshua , Clemente Jose C. , Leff Jonathan W. , Owens Sarah M. , Pollard Katherine S. , Knight Rob , Gilbert Jack A. , McCulley Rebecca L.
Published: October 2013

Prairie Redux

Tallgrass prairie is extinct across much of its former range in the midwestern United States, but relicts preserved in cemeteries and nature reserves allow functional comparison of former grassland soils with modern agricultural soils.

Fierer
et al.

(p.
621
; see the Perspective by

Scholes and Scholes

) took matched soil samples from sites representing the gamut of climate conditions and modeled the combination of genomic analysis and environmental data to resurrect the historical prairie soil communities, identifying the nutrient-scavenging Verrucomicrobia as keystone bacteria in functioning prairie.
One-Dimensional Electrical Contact to a Two-Dimensional Material
Authors: Wang L. , Meric I. , Huang P. Y. , Gao Q. , Gao Y. , Tran H. , Taniguchi T. , Watanabe K. , Campos L. M. , Muller D. A. , Guo J. , Kim P. , Hone J. , Shepard K. L. , Dean C. R.
Published: October 2013

Better Contact Along the Edge

Electrical contact to graphene is normally done with metal contacts on its flat face, where there are few strong bonding sites for the metal.

Wang
et al.

(p.
614
) encapsulated graphene with hexagonal boron nitride sheets and made metal contacts along its edge, where bonding orbitals are exposed. The resulting heterostructures had high electronic performance, with room-temperature carrier mobilities near the theoretical phonon-scattering limit.
Dust Unto Dust
Authors: Scholes Mary C. , Scholes Robert J.
Published: October 2013

Modern agriculture diminishes the diversity of soil biota, thereby reducing long-term soil fertility.

[Also see Report by

Fierer
et al.

]
Storing Quantum Information in Schrödinger's Cats
Authors: Leek Peter J.
Published: October 2013

Superposition states created with more than 100 photons enable the storage of multiple bits of quantum information.

[Also see Report by

Vlastakis
et al.

]
Deep Inside Champions, Just Genes?
The Sports Gene
Inside the Science of Extraordinary Athletic Performance/What Makes the Perfect Athlete

by David Epstein

Current, New York, 2013. 352 pp. $26.95. ISBN 9781591845119. Yellow Jersey, London. £16.99. ISBN 978-0224091619.
Authors: Greenbaum Dov , Chen Jieming , Gerstein Mark
Published: October 2013

Through a collection of examples, Epstein provides a balanced and nuanced consideration of genetic influences on athletic performance.
Quantized Electronic Heat Flow
Authors: Sothmann Björn , Flindt Christian
Published: October 2013

A measurement of the quantum-limited heat flow in an electronic conductor opens a pathway to the nanoscale control of heat currents.

[Also see Report by

Jezouin
et al.

]
Our Fallen Genomes
Authors: Macosko Evan Z. , McCarroll Steven A.
Published: October 2013

A human brain can cope with many genomic variations scattered among its neurons.

[Also see Report by

McConnell
et al.

]
Seize the Neuroscience Moment
Authors: Leshner Alan I.
Published: October 2013

There seems to be an abundance of neuroscience initiatives right now. This year, the European Commission launched a Human Brain Project, and the U.S. government announced its Brain Research through Advancing Innovative Neurotechnologies (BRAIN) project. They join other recent neuroscience efforts across the world aimed at advancing our understanding of the brain. Exploiting these diverse initiatives to yield scientific, clinical, and economic benefits, however, will require not only political and policy-maker support but also endorsement and extensive involvement by the neuroscience community, which already saw a “Decade of the Brain” come and go about 20 years ago, with little direct result. What's different now?
Short-Circuiting Depression
Authors: Underwood Emily
Published: October 2013

Experimental deep brain stimulation surgeries for depression are giving old theories about the disorder a jolt.
Discordance across Several Methods for Drug Susceptibility Testing of Drug-Resistant Mycobacterium tuberculosis Isolates in a Single Laboratory
Authors: Banu Sayera , Rahman S. M. Mazidur , Khan M. Siddiqur Rahman , Ferdous Sara Sabrina , Ahmed Shahriar , Gratz Jean , Stroup Suzanne , Pholwat Suporn , Heysell Scott K. , Houpt Eric R.
Published: October 2013

Given the increases in drug-resistant tuberculosis, laboratory capacities for drug susceptibility testing are being scaled up worldwide. A laboratory must decide among several endorsed methodologies. We evaluated 87
Mycobacterium tuberculosis
isolates for concordance of susceptibility results across six methods: the L-J proportion method, MGIT 960 SIRE AST, Gene/Xpert MTB/RIF, GenoType MTBDR
plus
line probe assay, MycoTB MIC plate, and a laboratory-developed mycobacteriophage quantitative PCR (qPCR)-based method. Most (80%) isolates were multidrug resistant. Of the culture-based methods, the mycobacteriophage qPCR method was fastest, the L-J proportion method was the slowest, and the MGIT method required the most repeat testing (
P
< 0.05). For isoniazid (INH), 82% of isolates were susceptible by all methods or resistant by all methods, whereas for rifampin (RIF), ethambutol (EMB), and streptomycin (STR), such complete concordance was observed in 77%, 50%, and 51% of isolates, respectively (
P
< 0.05 for INH or RIF versus EMB or STR). The discrepancies of EMB and STR stemmed largely from diminished concordance of the MGIT EMB results (kappa coefficient range, 0.26 to 0.30) and the L-J STR result (kappa range, 0.35 to 0.45) versus other methods. Phage qPCR and the MycoTB MIC plate were the only methods that yielded second-line susceptibilities and revealed significant quantitative correlations for all drugs except cycloserine, as well as moderate to excellent kappa coefficients for all drugs except for
para
-aminosalicylic acid. In summary, the performance of
M. tuberculosis
susceptibility testing differs by platform and by drug. Laboratories should carefully consider these factors before choosing one methodology, particularly in settings where EMB and STR results are clinically important.
Rapid Whole-Genome Sequencing for Detection and Characterization of Microorganisms Directly from Clinical Samples
Authors: Hasman Henrik , Saputra Dhany , Sicheritz-Ponten Thomas , Lund Ole , Svendsen Christina Aaby , Frimodt-Møller Niels , Aarestrup Frank M.
Published: October 2013

Whole-genome sequencing (WGS) is becoming available as a routine tool for clinical microbiology. If applied directly on clinical samples, this could further reduce diagnostic times and thereby improve control and treatment. A major bottleneck is the availability of fast and reliable bioinformatic tools. This study was conducted to evaluate the applicability of WGS directly on clinical samples and to develop easy-to-use bioinformatic tools for the analysis of sequencing data. Thirty-five random urine samples from patients with suspected urinary tract infections were examined using conventional microbiology, WGS of isolated bacteria, and direct sequencing on pellets from the urine samples. A rapid method for analyzing the sequence data was developed. Bacteria were cultivated from 19 samples but in pure cultures from only 17 samples. WGS improved the identification of the cultivated bacteria, and almost complete agreement was observed between phenotypic and predicted antimicrobial susceptibilities. Complete agreement was observed between species identification, multilocus sequence typing, and phylogenetic relationships for
Escherichia coli
and
Enterococcus faecalis
isolates when the results of WGS of cultured isolates and urine samples were directly compared. Sequencing directly from the urine enabled bacterial identification in polymicrobial samples. Additional putative pathogenic strains were observed in some culture-negative samples. WGS directly on clinical samples can provide clinically relevant information and drastically reduce diagnostic times. This may prove very useful, but the need for data analysis is still a hurdle to clinical implementation. To overcome this problem, a publicly available bioinformatic tool was developed in this study.
Analysis of Serine Codon Conservation Reveals Diverse Phenotypic Constraints on Hepatitis C Virus Glycoprotein Evolution
Authors: Brown Richard J. P. , Koutsoudakis George , Urbanowicz Richard A. , Mirza Deeman , Ginkel Corinne , Riebesehl Nina , Calland Noémie , Albecka Anna , Price Louisa , Hudson Natalia , Descamps Véronique , Backx Matthijs , McClure C. Patrick , Duverlie Gilles , Pecheur Eve-Isabelle , Dubuisson Jean , Perez-del-Pulgar Sofia , Forns Xavier , Steinmann Eike , Tarr Alexander W. , Pietschmann Thomas , Ball Jonathan K.
Published: October 2013

Serine is encoded by two divergent codon types, UCN and AGY, which are not interchangeable by a single nucleotide substitution. Switching between codon types therefore occurs via intermediates (threonine or cysteine) or via simultaneous tandem substitutions. Hepatitis C virus (HCV) chronically infects 2 to 3% of the global population. The highly variable glycoproteins E1 and E2 decorate the surface of the viral envelope, facilitate cellular entry, and are targets for host immunity. Comparative sequence analysis of globally sampled
E1E2
genes, coupled with phylogenetic analysis, reveals the signatures of multiple archaic codon-switching events at seven highly conserved serine residues. Limited detection of intermediate phenotypes indicates that associated fitness costs restrict their fixation in divergent HCV lineages. Mutational pathways underlying codon switching were probed via reverse genetics, assessing glycoprotein functionality using multiple
in vitro
systems. These data demonstrate selection against intermediate phenotypes can act at the structural/functional level, with some intermediates displaying impaired virion assembly and/or decreased capacity for target cell entry. These effects act in residue/isolate-specific manner. Selection against intermediates is also provided by humoral targeting, with some intermediates exhibiting increased epitope exposure and enhanced neutralization sensitivity, despite maintaining a capacity for target cell entry. Thus, purifying selection against intermediates limits their frequencies in globally sampled strains, with divergent functional constraints at the protein level restricting the fixation of deleterious mutations. Overall our study provides an experimental framework for identification of barriers limiting viral substitutional evolution and indicates that serine codon-switching represents a genomic “fossil record” of historical purifying selection against E1E2 intermediate phenotypes.
Immunosuppression Facilitates the Reactivation of Latent Papillomavirus Infections
Authors: Maglennon G. A. , McIntosh P. B. , Doorbar J.
Published: October 2013

At mucosal sites, papillomavirus genomes can persist in the epithelial basal layer following immune-mediated regression. Subsequent T-cell depletion stimulates a 3- to 5-log increase in the viral copy number, to levels associated with productive infection. Reappearance of microlesions was rare within the short time frame of our experiments but was observed in one instance. Our studies provide direct evidence that immunosuppression can trigger the reactivation of latent papillomavirus genomes, as previously proposed in humans.
Type I Interferon Limits the Capacity of Bluetongue Virus To Infect Hematopoietic Precursors and Dendritic Cells
In Vitro
and
In Vivo
Authors: Rodríguez-Calvo Teresa , Rojas José-Manuel , Martín Verónica , Sevilla Noemí
Published: October 2013

Hematopoietic stem cells (HSCs) give rise to progenitors with potential to produce multiple cell types, including dendritic cells (DCs). DCs are the principal antigen-presenting cells and represent the crucial link between innate and adaptive immune responses. Bluetongue virus (BTV), an economically important
Orbivirus
of the
Reoviridae
family, causes a hemorrhagic disease mainly in sheep and occasionally in other species of ruminants. BTV is transmitted between its mammalian hosts by certain species of biting midges (
Culicoides
spp.) and is a potent alpha interferon (IFN-α) inducer. In the present report, we show that BTV infects cells of hematopoietic origin but not HSCs in immunocompetent sheep. However, BTV infects HSCs in the absence of type I IFN (IFN-I) signaling
in vitro
and
in vivo
. Infection of HSCs
in vitro
results in cellular death by apoptosis. Furthermore, BTV infects bone marrow-derived DCs (BM-DCs), interfering with their development to mature DCs in the absence of type I IFN signaling. Costimulatory molecules CD80 and CD86 and costimulatory molecules CD40 and major histocompatibility complex class II (MHC-II) are affected by BTV infection, suggesting that BTV interferes with DC antigen-presenting capacity.
In vivo
, different DC populations are also affected during the course of infection, probably as a result of a direct effect of BTV replication in DCs and the production of infectious virus. These new findings suggest that BTV infection of HSCs and DCs can impair the immune response, leading to persistence or animal death, and that this relies on IFN-I.
Herpes Simplex Virus 1 Protein Kinase Us3 Phosphorylates Viral dUTPase and Regulates Its Catalytic Activity in Infected Cells
Authors: Kato Akihisa , Tsuda Shumpei , Liu Zhuoming , Kozuka-Hata Hiroko , Oyama Masaaki , Kawaguchi Yasushi
Published: October 2013

Us3 is a serine-threonine protein kinase encoded by herpes simplex virus 1 (HSV-1). In this study, a large-scale phosphoproteomic analysis of titanium dioxide affinity chromatography-enriched phosphopeptides from HSV-1-infected cells using high-accuracy mass spectrometry (MS) and subsequent analyses showed that Us3 phosphorylated HSV-1-encoded dUTPase (vdUTPase) at serine 187 (Ser-187) in HSV-1-infected cells. Thus, the following observations were made. (i) In
in vitro
kinase assays, Ser-187 in the vdUTPase domain was specifically phosphorylated by Us3. (ii) Phosphorylation of vdUTPase Ser-187 in HSV-1-infected cells was detected by phosphate-affinity polyacrylamide gel electrophoresis analyses and was dependent on the kinase activity of Us3. (iii) Replacement of Ser-187 with alanine (S187A) in vdUTPase and an amino acid substitution in Us3 that inactivated its kinase activity significantly downregulated the enzymatic activity of vdUTPase in HSV-1-infected cells, whereas a phosphomimetic substitution at vdUTPase Ser-187 restored the wild-type enzymatic activity of vdUTPase. (iv) The vdUTPase S187A mutation as well as the kinase-dead mutation in Us3 significantly reduced HSV-1 replication in human neuroblastoma SK-N-SH cells at a multiplicity of infection (MOI) of 5 but not at an MOI of 0.01, whereas the phosphomimetic substitution at vdUTPase Ser-187 restored the wild-type viral replication at an MOI of 5. In contrast, these mutations had no effect on HSV-1 replication in Vero and HEp-2 cells. Collectively, our results suggested that Us3 phosphorylation of vdUTPase Ser-187 promoted HSV-1 replication in a manner dependent on cell types and MOIs by regulating optimal enzymatic activity of vdUTPase.
Characterization of Blockade Antibody Responses in GII.2.1976 Snow Mountain Virus-Infected Subjects
Authors: Swanstrom Jesica , Lindesmith Lisa C. , Donaldson Eric F. , Yount Boyd , Baric Ralph S.
Published: October 2013

Snow Mountain virus (GII.2.1976) is the prototype strain of GII.2 noroviruses (NoVs), which cause an estimated 8% of norovirus outbreaks, yet little is known about the immunobiology of these viruses. To define the human immune response induced by SMV infection and the antigenic relationship between different GII.2 strains that have circulated between 1976 and 2010, we developed a panel of four GII.2 variant virus-like particles (VLPs) and compared their antigenicities by enzyme immunoassay (EIA) and surrogate antibody neutralization (blockade) assays. Volunteers infected with GII.2.1976 developed a mean 167-fold increase in blockade response against the homotypic VLP by day 8 postchallenge. Blockade extended cross-genotype activity in some individuals but not cross-genogroup activity. Polyclonal sera from GII.2.1976-infected volunteers blocked GII.2.1976 significantly better than they blocked GII.2.2002, GII.2.2008, and GII.2.2010, suggesting that blockade epitopes within the GII.2 strains have evolved in the past decade. To potentially map these epitope changes, we developed mouse monoclonal antibodies (MAbs) against GII.2.1976 VLPs and compared their reactivities to a panel of norovirus VLPs. One MAb had broad cross-genogroup EIA reactivity to a nonblockade, linear, conserved epitope. Six MAbs recognized conformational epitopes exclusive to the GII.2 strains. Two MAbs recognized GII.2 blockade epitopes, and both blocked the entire panel of GII.2 variants. These data indicate that the GII.2 strains, unlike the predominant GII.4 strains, have undergone only a limited amount of evolution in blockade epitopes between 1976 and 2010 and indicate that the GII.2-protective component of a multivalent norovirus vaccine may not require frequent reformulation.
Aluminium phosphide-induced leukopenia
Authors: Ntelios Dimitrios , Mandros Charalampos , Potolidis Evangelos , Fanourgiakis Panagiotis
Published: October 2013

Acute intoxication from the pesticide aluminium phosphide is a relatively rare, life-threatening condition in which cardiovascular decompensation is the most feared problem. We report the case of a patient exposed to aluminium phosphide-liberated phosphine gas. It resulted in the development of a gastroenteritis-like syndrome accompanied by severe reduction in white blood cell numbers as an early and prominent manifestation. By affecting important physiological processes such as mitochondrial function and reactive oxygen species homeostasis, phosphine could cause severe toxicity. After presenting the characteristics of certain leucocyte subpopulations we provide the current molecular understanding of the observed leukopenia which in part seems paradoxical.
Is there a relationship between subacromial impingement syndrome and scapular orientation? A systematic review
Authors: Ratcliffe Elizabeth , Pickering Sharon , McLean Sionnadh , Lewis Jeremy
Published: October 2013

Background

Alterations in scapular orientation and dynamic control, specifically involving increased anterior tilt and downward rotation, are considered to play a substantial role in contributing to a subacromial impingement syndrome (SIS). Non-surgical intervention aims at restoring normal scapular posture. The research evidence supporting this practice is equivocal.

Objective

The aim of this study was to systematically review the relevant literature to examine whether a difference exists in scapular orientation between people without shoulder symptoms and those with SIS.

Data sources

MEDLINE, AMED, EMBASE, CINAHL, PEDro and SPORTDiscus databases were searched using relevant search terms up to August 2013. Additional studies were identified by hand-searching the reference lists of pertinent articles.

Review methods

Of the 7445 abstracts identified, 18 were selected for further analysis. Two reviewers independently assessed the studies for inclusion, data extraction and quality, using a modified Downs and Black quality assessment tool.

Results

10 trials were included in the review. Scapular position was determined through two-dimensional radiological measurements, 360° inclinometers and three-dimensional motion and tracking devices. The findings were inconsistent. Some studies reported patterns of reduced upward rotation, increased anterior tilting and medial rotation of the scapula. In contrast, others reported the opposite, and some identified no difference in motion when compared to asymptomatic controls.

Conclusions

The underlying aetiology of SIS is still debated. The results of this review demonstrated a lack of consistency of study methodologies and results. Currently, there is insufficient evidence to support a clinical belief that the scapula adopts a common and consistent posture in SIS. This may reflect the complex, multifactorial nature of the syndrome. Additionally, it may be due to the methodological variations and shortfalls in the available research. It also raises the possibility that deviation from a ‘normal’ scapular position may not be contributory to SIS but part of normal variations. Further research is required to establish whether a common pattern exists in scapular kinematics in SIS patients or whether subgroups of patients with common patterns can be identified to guide management options. Non-surgical treatment involving rehabilitation of the scapula to an idealised normal posture is currently not supported by the available literature.
Higher psychological distress is associated with unintentional injuries in US adults
Authors: McAninch Jana , Greene Christina , Sorkin John D , Lavoie Marie-Claude , Smith Gordon S
Published: October 2013

Background

Links between mental illness, self-inflicted injury and interpersonal violence are well recognised, but the association between poor mental health and unintentional injuries is not well understood.

Methods

We used the 2010 National Health Interview Survey to assess the association between psychological distress and unintentional non-occupational injuries among US adults. Psychological distress was measured by the Kessler Psychological Distress Scale, a symptom scale shown to identify community-dwelling persons with mental illness. Multivariable logistic regression was used to estimate adjusted ORs (AOR) and 95% CIs.

Results

Of the 26 776 individuals analysed, 2.5% reported a medically attended unintentional injury in the past 3 months. Those with moderate and severe psychological distress had 1.5 (1.2 to 1.8) and 2.0 (1.4 to 2.8) times higher odds of injury, respectively, as compared to those with low distress levels, after adjusting for age, sex, race, marital status, education level, alcohol use, physical functional limitation, medical comorbidity, employment status and health insurance status. Psychological distress was significantly associated with falls (AOR 1.4 (1.1 to 1.9)) and sprain/strain injuries (AOR 2.0 (1.5 to 2.8)), but not transportation-related injuries (AOR 1.2 (0.7 to 1.9)) or fractures (AOR 1.1 (0.8 to 1.6)).

Conclusions

Among community-dwelling US adults, psychological distress is significantly associated with unintentional non-occupational injury, and the magnitude of association increases with severity of distress. The association between psychological distress and injury may be particularly strong for falls and sprain/strain injuries. These findings draw attention to a large group of at-risk individuals that may merit further targeted research, including longitudinal studies.
Comparison of the swimming ability and upstream-migration behavior between chum salmon and masu salmon
Authors: Miyoshi Koji , Hayashida Kazufumi , Sakashita Taku , Fujii Makoto , Nii Hisaya , Nakao Katsuya , Ueda Hiroshi
Published: October 2013

The spawning ground of chum salmon (Oncorhynchus keta) is usually located farther downriver than that of masu salmon (Oncorhynchus masou) in Hokkaido, Japan. To compare the swimming abilities of these two species, the relationship between swimming speed and oxygen consumption was compared using a swim tunnel in the laboratory. Then, the upstream-migration behaviors of chum salmon and masu salmon were compared using electromyogram telemetry at fish passages in the Toyohira River, Hokkaido. In the laboratory study, the standard metabolic rate of masu salmon was lower and the critical swimming speed (Ucrit) was faster than those of chum salmon. In the field study, the holding time needed to recover the swimming performance exceeding Ucritat the fish passages and the trial number needed to pass the fish passages were significantly lower for masu salmon than chum salmon. These results revealed that masu salmon are more adaptable to extended swimming in high water velocity conditions than chum salmon and that masu salmon are better equipped for a long distance upstream migration to their spawning ground than chum salmon.
ANDERSON LOCALIZATION FOR A MULTI-PARTICLE QUANTUM GRAPH
Authors: SABRI MOSTAFA
Published: October 2013

We study a multi-particle quantum graph with random potential. Taking the approach of multiscale analysis, we prove exponential and strong dynamical localization of any order in the Hilbert–Schmidt norm near the spectral edge. Apart from the results on multi-particle systems, we also prove Lifshitz-type asymptotics for single-particle systems. This shows in particular that localization for single-particle quantum graphs holds under a weaker assumption on the random potential than previously known.
EQUIVARIANT SYMPLECTIC HOMOLOGY AND MULTIPLE CLOSED REEB ORBITS
Authors: KANG JUNGSOO
Published: October 2013

We study the existence of multiple closed Reeb orbits on some contact manifolds by means of S1-equivariant symplectic homology and the index iteration formula. We prove that a certain class of contact manifolds which admits displaceable exact contact embeddings, a certain class of prequantization bundles, and Brieskorn spheres have multiple closed Reeb orbits.
EFFECTS OF NONCOMMUTATIVITY ON LIGHT HYDROGEN-LIKE ATOMS AND PROTON RADIUS
Authors: MOUMNI M. , BENSLAMA A.
Published: October 2013

We study the corrections induced by the theory of noncommutativity, in both space–space and space–time versions, on the spectrum of hydrogen-like atoms. For this, we use the relativistic theory of two-particle systems to take into account the effects of the reduced mass, and we use perturbation methods to study the effects of noncommutativity. We apply our study to the muon hydrogen with the aim to solve the puzzle of proton radius [R. Pohl et al., Nature466, 213 (2010) and A. Antognini et al., Science339, 417 (2013)]. The shifts in the spectrum are found more noticeable in muon H(μH) than in electron H(eH) because the corrections depend on the mass to the third power. This explains the discrepancy between μH and eH results. In space–space noncommutativity, the parameter required to resolve the puzzle θ ss ≈(0.35 GeV )-2, exceeds the limit obtained for this parameter from various studies on eH Lamb shift. For space–time noncommutativity, the value θ st ≈(14.3 GeV )-2 has been obtained and it is in agreement with the limit determined by Lamb shift spectroscopy in eH. We have also found that this value fills the gap between theory and experiment in the case of μD and improves the agreement between theoretical and experimental values in the case of hydrogen–deuterium isotope shift.
A COMPARABLE STUDY ON STRUCTURAL AND OPTICAL PROPERTIES OFCu2ZnSnS4ANDCu2ZnSnSe4NANOCRYSTALLINES
Authors: GU XIUQUAN , ZHANG SHUANG , ZHAO YULONG , ZHU LEI , QIANG YINGHUAI
Published: October 2013

In this study, single-kesterite-phase Cu2ZnSnS4(CZTS) and Cu2ZnSnSe4(CZTSe) nanocrystallines have been synthesized by a simple solvothermal route. Scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible (UV-vis) absorbance and Raman scattering spectroscopy were used to characterize the optical and micro-structure properties of the as-synthesized samples. The bandgap of CZTS could be tuned in a large range by incorporating a few Se atoms. Both the CZTS and CZTSe exhibited the similar temperature dependence of the Raman "A" modes, including a monotonic redshift in peak position and an irregular variation in peak linewidth. Such a behavior might be due to the cumulative effect of thermal expansion and small crystalline sizes.
π-PEAKING SHUNT-FEEDBACK TRANSIMPEDANCE AMPLIFIER WITH BANDWIDTH ENHANCEMENT
Authors: SINSOONTORNPONG PANUS , WORAPISHET APISAK
Published: October 2013

This paper presents the development of a bandwidth enhancement technique for a resistive shunt-feedback transimpedance amplifier (TIA). The technique relies upon a π-peaking network realization using the shunt-feedback TIA as a part of the network in order to achieve a high bandwidth while maintaining a low noise performance. The output is obtained by making use of subsequent amplifier stages with the non-uniform constant-k output network for simultaneously high gain and bandwidth. Practical performance verification was provided via the designs and simulations of two π-peaking TIAs in a silicon CMOS implementation and a discrete HJFET implementation. Simulated results clearly indicates superior bandwidth of the π-peaking TIA over the conventional shunt-feedback TIA at practically no cost to circuit complexity and power consumption.
Personal Recommendation Via Heterogeneous Diffusion on Bipartite Network
Authors: Ju Chunhua , Xu Chonghuan
Published: October 2013

Recommender systems have proven to be an effective method to deal with the problem of information overload in finding interesting products. It is still a challenge to increase the accuracy and diversity of recommendation algorithms to fulfill users' preferences. To provide a better solution, in this paper, we propose a novel recommendation algorithm based on heterogeneous diffusion process on a user-object bipartite network. This algorithm generates personalized recommendation results on the basis of the physical dynamic feature of resources diffusion which is influenced by objects' degrees and users' interest degrees. Detailed numerical analysis on two benchmark datasets shows that the presented algorithm is of high accuracy, and also generates more diversity.
Extractor X — Autonomous Tilt Rotor UAV
Authors: En Chao Joshua Jang
Published: October 2013

This paper looks into conceptualization, implementation and validation of the potential role that hybrid quad tilt rotor unmanned aerial vehicles (UAV) may undertake in the near future, especially so in military applications. A tilt rotor is designed, built and analyzed with wind tunnel data, theoretical calculations and flight log data. In addition, the paper will discuss the flight mechanics involved during its transition from hover to forward flight. As the tandem wing tilt rotor encompasses two unconventional designs, numerous mathematical models were developed in the design of the UAV.
Calcium dynamics underlying the myogenic response of the renal afferent arteriole
Authors: Edwards Aurélie , Layton Anita T.
Published: October 2013

The renal afferent arteriole reacts to an elevation in blood pressure with an increase in muscle tone and a decrease in luminal diameter. This effect, known as the myogenic response, is believed to stabilize glomerular filtration and to protect the glomerulus from systolic blood pressure increases, especially in hypertension. To study the mechanisms underlying the myogenic response, we developed a mathematical model of intracellular Ca2+ signaling in an afferent arteriole smooth muscle cell. The model represents detailed transmembrane ionic transport, intracellular Ca2+ dynamics, the kinetics of myosin light chain phosphorylation, and the mechanical behavior of the cell. It assumes that the myogenic response is initiated by pressure-induced changes in the activity of nonselective cation channels. Our model predicts spontaneous vasomotion at physiological luminal pressures and KCl- and diltiazem-induced diameter changes comparable to experimental findings. The time-periodic oscillations stem from the dynamic exchange of Ca2+ between the cytosol and the sarcoplasmic reticulum, coupled to the stimulation of Ca2+-activated potassium (KCa) and chloride (ClCa) channels, and the modulation of voltage-activated L-type channels; blocking sarco/endoplasmic reticulum Ca2+ pumps, ryanodine receptors (RyR), KCa, ClCa, or L-type channels abolishes these oscillations. Our results indicate that the profile of the myogenic response is also strongly dependent on the conductance of ClCa and L-type channels, as well as the activity of plasmalemmal Ca2+ pumps. Furthermore, inhibition of KCa is not necessary to induce myogenic contraction. Lastly, our model suggests that the kinetic behavior of L-type channels results in myogenic kinetics that are substantially faster during constriction than during dilation, consistent with in vitro observations (Loutzenhiser R, Bidani A, Chilton L. Circ. Res. 90: 1316–1324, 2002).
Incomplete k-Fibonacci and k-Lucas Numbers
Authors: Ramírez José L.
Published: October 2013

We define the incomplete k-Fibonacci and k-Lucas numbers; we study the recurrence relations and some properties of these numbers.