bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling interface roughness scattering in a layered seabed for normal-incident chirp sonar signals
Authors: Tang Dajun , Hefner Brian T.
Published: March 2012

Downward looking sonar, such as the chirp sonar, is widely used as a sediment survey tool in shallow water environments. Inversion of geo-acoustic parameters from such sonar data precedes the availability of forward models. An exact numerical model is developed to initiate the simulation of the acoustic field produced by such a sonar in the presence of multiple rough interfaces. The sediment layers are assumed to be fluid layers with non-intercepting rough interfaces.
Time reversal acoustic communication for multiband transmission
Authors: Song Aijun , Badiey Mohsen
Published: March 2012

In this letter, multiband acoustic communication is proposed to access a relatively wide frequency band. The entire frequency band is divided into multiple separated sub-bands, each of which is several kilohertz in width. Time reversal decision feedback equalizers are used to compensate for inter-symbol interference at each sub-band. The communication scheme was demonstrated in a shallow water acoustic experiment conducted in Kauai, Hawaii during the summer of 2011. Using quadrature phase-shift keying signaling at four sub-bands over the frequency band of 10–32 kHz, a data rate of 32 kbits/s was achieved over a 3 km communication range.
Acoustic performance of a duct loaded with identical resonators
Authors: Wang X. , Mak C. M.
Published: March 2012

This paper presents a theoretical study of a duct loaded with identical side-branch resonators. The Bloch wave theory and the transfer matrix method are used to investigate wave propagation in the duct. It is found that this duct-resonator system has a unique attenuation characteristic brought about by structural periodicity. Three types of stop-bands are discussed and their bandwidths are predicted. All of the results predicted by the theory fit well with a computer simulation using a three-dimensional finite element method. Compared to a single resonator, this structure may have a potential application in broadband noise control.
Individual and level-dependent differences in masking for adults with normal and impaired hearing
Authors: Horwitz Amy R. , Ahlstrom Jayne B. , Dubno Judy R.
Published: March 2012

Simultaneous, on-frequency masking is commonly assumed to be linear with increasing noise intensity. However, some evidence suggests that, expressed in terms of signal-to-noise ratio changes with background level changes, masking slopes can vary from 0 dB/dB. These results and evidence from a large sample of subjects with normal and impaired hearing demonstrate level-dependent changes in masking, large individual differences in masking among subjects with similar thresholds in quiet, and significant correlations of masking slope with other estimates of auditory function measured in the same backgrounds.
Human Evolution Out of Africa: The Role of Refugia and Climate Change
Authors: Stewart J. R. , Stringer C. B.
Published: March 2012

Ancient Human Migration

During the past 100,000 years or so, modern humans migrated from Africa into Eurasia, completely replacing existing populations of Neandertals by about 20,000 years ago. This occurred as the climate cooled toward a glacial maximum.
Stewart and Stringer
(p.
1317
) review some of the recent evidence for how this demographic transition occurred. Data from ancient genomes of Neandertals and Denisovans coupled with our improved understanding of the role of refugia in driving evolution during the Ice Ages suggest that such refugia were important in the pace and pattern of change.
The Fern Sporangium: A Unique Catapult
Authors: Noblin X. , Rojas N. O. , Westbrook J. , Llorens C. , Argentina M. , Dumais J.
Published: March 2012

High-speed observations reveal how rapid changes in cell shape powerfully eject fern spores.
Laser Scribing of High-Performance and Flexible Graphene-Based Electrochemical Capacitors
Authors: El-Kady Maher F. , Strong Veronica , Dubin Sergey , Kaner Richard B.
Published: March 2012

Infrared Route to Graphene Electrodes

Electrochemical capacitors can deliver large amounts of power quickly, but have limited energy storage because only the surface regions of electrodes can store charge. Graphene represents an alternative to activated carbon electrodes because of their high conductivity and surface area, but graphene sheets tend to reassociate and lose surface area.

El-Kady
et al.

(p.
1326
; see the Perspective by

Miller

) show that graphite oxide sheets can be converted by infrared laser irradiation into porous graphene sheets that are flexible, robust, and highly conductive.
Decoding in the Absence of a Codon by tmRNA and SmpB in the Ribosome
Authors: Neubauer Cajetan , Gillet Reynald , Kelley Ann C. , Ramakrishnan V.
Published: March 2012

Ribosome Rescue

Ribosomes stall when they reach the end of defective messenger RNAs (mRNAs). In bacteria, the most-studied ribosomal rescue pathway involves a ribonucleoprotein complex comprising tmRNA (which acts as both transfer RNA and mRNA) and the protein SmpB. In an alternative pathway, some Gram-negative bacteria contain proteins that achieve tmRNA-independent rescue. Now,

Neubauer
et al.

(p.
1366
) present the structure of the
Thermus thermophilus
ribosome bound to a fragment of tmRNA, SmpB, and elongation factor Tu, and

Gagnon
et al.

(p.
1370
) report the structure of the
T. thermophilus
ribosome in complex with an initiator tRNA, a short mRNA fragment, and the rescue factor YaeJ. Though the two rescue systems are very different, both involve a protein tail that binds in the mRNA channel. This orients the rescue apparatus to facilitate switching translation to a different message in the tmRNA system or hydrolysis of peptidyl tRNA by YaeJ.
Capping a Survey of All Extant Birds
Handbook of the Birds of the World
Volume 16, Tanagers to New World Blackbirds

Josep del Hoyo, Andrew Elliott, and David A. Christie, Eds.

Lynx Edicions, Barcelona, 2011. 893 pp. €212, $280, £178. ISBN 9788496553781.
Authors: Garrett Kimball L.
Published: March 2012

With this 16th volume, del Hoyo
et al.
wrap up a 20-year series that covers all extant avian species.
Getting Molecular Electrons into Motion
Authors: Gühr Markus
Published: March 2012

A method based on correlated measurements of electrons and ions shows that electrons of large molecules can be set into motion by strong laser fields.
Membrane Bending Tug of War
Authors: Silvius John
Published: March 2012

Membrane protein crowding may influence the biological processes that drive vesicle formation.
Norton Zinder (1928–2012)
Authors: Lodish Harvey , Fedoroff Nina
Published: March 2012

The seminal work of this geneticist and microbiologist on bacteriophage contributed importantly to our understanding of fundamental genetic processes.
Critics Assail Notion That Europeans Settled Americas
Authors: Balter Michael
Published: March 2012

A new book has reignited debate over a long-discredited hypothesis that the first Americans came from Europe rather than Asia. Although few scientists actually support the hypothesis, some still think it merits additional testing.
LIFE SCIENCE TECHNOLOGIES: Polymer Science Tries To Make It Easy To Be Green
Authors: Dove Alan
Published: March 2012

The modern world can't function without plastics, but the planet's environment may not be able to function with them. Can a new generation of polymer chemists rehabilitate these ubiquitous but environmentally troubling materials?
HIV-1 Proviral DNA Loads (as Determined by Quantitative PCR) in Patients Subjected to Structured Treatment Interruption after Antiretroviral Therapy Failure
Authors: Komninakis Shirley V. , Santos Domingos E. M. , Santos Carlos , Oliveros Márcia P. R. , Sanabani Sabri , Diaz Ricardo S.
Published: March 2012

The impact of Structured Treatment Interruption (STI) in peripheral blood mononuclear cell (PBMC) proviral reservoirs in 41 highly active antiretroviral therapy (HAART)-treated viremic individuals at baseline and 12 weeks after STI was determined using quantitative PCR (qPCR). Viral load increased 0.7 log
10
and CD4 decreased 97.5 cells/mm
3
after 12 weeks. A total of 28 of the 41 individuals showed an increased proviral load, 19 with a statistically significant increase above 10%. An increase in active viral replication is an important factor in the replenishment of the proviral reservoir even for short time periods.
Association between β-Lactamase-Encoding
bla
OXA-51
Variants and DiversiLab Rep-PCR-Based Typing of Acinetobacter baumannii Isolates
Authors: Zander Esther , Nemec Alexandr , Seifert Harald , Higgins Paul G.
Published: March 2012

This study investigated the correlation between
bla
OXA-51
variants and
Acinetobacter baumannii
worldwide clonal lineages 1 to 8 (WW1 to -8). The
bla
OXA-51-like
genes of 102
A. baumannii
isolates were sequenced. Using DiversiLab repetitive-sequence-based PCR (rep-PCR) typing, 92 of these isolates had previously been assigned to WW1 to -8 and 10 were unclustered. Clustering of DNA sequences was performed using the neighbor-joining method and the Jukes-Cantor phylogenetic correction.
bla
OXA-51
variants were in good correlation with DiversiLab-defined clonal lineages. Sequence-based typing of
bla
OXA-51
variants has the potential to be applied for epidemiologic characterization of
A. baumannii
and to identify worldwide clonal lineages 1 to 8.
Standardized One-Step Real-Time Reverse Transcription-PCR Assay for Universal Detection and Quantification of Hepatitis Delta Virus from Clinical Samples in the Presence of a Heterologous Internal-Control RNA
Authors: Scholtes Caroline , Icard Vinca , Amiri Majid , Chevallier-Queyron Philippe , Trabaud Mary-Anne , Ramière Christophe , Zoulim Fabien , André Patrice , Dény Paul
Published: March 2012

As for other chronic viral diseases, quantification of hepatitis delta virus (HDV) loads may be useful for patient management. We describe a one-step quantitative reverse transcription-PCR assay that is reliable and automatable and meets the regulatory authorities' standards for accurate quantification of the major HDV genotypes. It includes an internal control and uses
in vitro
-transcribed RNAs as standards. Its linearity range is 500 to 1.7 × 10
11
copies/ml, its sensitivity is around 150 copies/ml, its repeatability is around 15%, and its reproducibility is below 0.25 log
10
copies/ml.
Modified Vaccinia Virus Ankara-Based Vaccine Vectors Induce Apoptosis in Dendritic Cells Draining from the Skin via both the Extrinsic and Intrinsic Caspase Pathways, Preventing Efficient Antigen Presentation
Authors: Guzman E. , Cubillos-Zapata C. , Cottingham M. G. , Gilbert S. C. , Prentice H. , Charleston B. , Hope J. C.
Published: March 2012

Dendritic cells (DC) are potent antigen-presenting cells and central to the induction of immune responses following infection or vaccination. The collection of DC migrating from peripheral tissues by cannulation of the afferent lymphatic vessels provides DC which can be used directlyex vivowithout extensivein vitromanipulations. We have previously used bovine migrating DC to show that recombinant human adenovirus 5 vectors efficiently transduce afferent lymph migrating DEC-205+CD11c+CD8−DC (ALDC). We have also shown that recombinant modified vaccinia virus Ankara (MVA) infects ALDCin vitro, causing downregulation of costimulatory molecules, apoptosis, and cell death. We now show that in the bovine system, modified vaccinia virus Ankara-induced apoptosis in DC draining from the skin occurs soon after virus binding via the caspase 8 pathway and is not associated with viral gene expression. We also show that after virus entry, the caspase 9 pathway cascade is initiated. The magnitude of T cell responses to mycobacterial antigen 85A (Ag85A) expressed by recombinant MVA-infected ALDC is increased by blocking caspase-induced apoptosis. Apoptotic bodies generated by recombinant MVA (rMVA)-Ag85A-infected ALDC and containing Ag85A were phagocytosed by noninfected migrating ALDC expressing SIRPα via actin-dependent phagocytosis, and these ALDC in turn presented antigen. However, the addition of fresh ALDC to MVA-infected cultures did not improve on the magnitude of the T cell responses; in contrast, these noninfected DC showed downregulation of major histocompatibility complex class II (MHC-II), CD40, CD80, and CD86. We also observed that MVA-infected ALDC promoted migration of DEC-205+SIRPα+CD21+DC as well as CD4+and CD8+T cells independently of caspase activation. Thesein vitrostudies show that induction of apoptosis in DC by MVA vectors is detrimental to the subsequent induction of T cell responses.
The Magnitude of Dengue Virus NS1 Protein Secretion Is Strain Dependent and Does Not Correlate with Severe Pathologies in the Mouse Infection Model
Authors: Watanabe Satoru , Tan Kah Hin , Rathore Abhay P. S. , Rozen-Gagnon Kathryn , Shuai Wang , Ruedl Christiane , Vasudevan Subhash G.
Published: March 2012

There are conflicting data on the relationship between the level of secreted NS1 (sNS1), viremia, and disease severity upon dengue virus (DENV) infection in the clinical setting, and therefore, we examined this relationship in the widely accepted AG129 mouse model. Because of the failure of a routinely used NS1 detection kit to detect sNS1 of the mouse-adapted DENV2 strain, we screened 15 previously undescribed NS1 monoclonal antibodies and developed a robust capture enzyme-linked immunosorbent assay (ELISA) with detection sensitivity at the low nanogram level (0.2 ng/ml) using recombinant baculovirus-expressed sNS1 as well as sNS1 that was immunoaffinity purified from the various DENV2 strains employed in this study. Using this test, we demonstrated that increased viremia paralleled severe pathologies; however, sNS1 level did not correlate with viremia or severity. Furthermore, among the DENV2 strains that were tested, the level of NS1 secretion did not correspond to virus replication ratein vitro, at the cellular level. Together, our data indicate that the magnitude of NS1 secretion appears to be strain dependent and does not correlate with viral virulence in the AG129 mouse model.
SECOND-ORDER LAGRANGIAN DYNAMICS IN THE PHASE-SPACE: SOME EXAMPLES
Authors: BIZDADEA CONSTANTIN , BÂRCAN MARIA-MAGDALENA , MIAUTĂ MIHAELA TINCA , SALIU SOLANGE-ODILE
Published: March 2012

By means of a class of nondegenerate models with a finite number of degrees of freedom, it is proved that given a Hamiltonian formulation of dynamics, there exists an equivalent second-order Lagrangian formulation whose configuration space coincides with the Hamiltonian phase-space. The above result is extended to scalar field theories in a Lorentz-covariant manner.
OPERA NEUTRINOS AND DEFORMED SPECIAL RELATIVITY
Authors: AMELINO-CAMELIA GIOVANNI , FREIDEL LAURENT , KOWALSKI-GLIKMAN JERZY , SMOLIN LEE
Published: March 2012

In a recent study, Cohen and Glashow argue that superluminal neutrinos of the type recently reported by OPERA should be affected by anomalous Cherenkov-like processes. This causes them to lose much of their energy before reaching the OPERA detectors. Related concerns were reported also by Gonzalez-Mestres, Bi et al., and Cowsik et al., who argued that pions cannot decay to superluminal neutrinos over part of the energy range studied by OPERA. We observe here that these arguments are set within a framework in which Lorentz symmetry is broken, by the presence of a preferred frame. We further show that these anomalous processes are forbidden if Lorentz symmetry is instead "deformed", preserving the relativity of inertial frames. These deformations add nonlinear terms to energy–momentum relations, conservation laws and Lorentz transformations in a way that is consistent with the relativity of inertial observers.
Effects of priming exercise on the speed of adjustment of muscle oxidative metabolism at the onset of moderate-intensity step transitions in older adults
Authors: De Roia Gabriela , Pogliaghi Silvia , Adami Alessandra , Papadopoulou Christina , Capelli Carlo
Published: March 2012

Aging is associated with a functional decline of the oxidative metabolism due to progressive limitations of both O2 delivery and utilization. Priming exercise (PE) increases the speed of adjustment of oxidative metabolism during successive moderate-intensity transitions. We tested the hypothesis that such improvement is due to a better matching of O2 delivery to utilization within the working muscles. In 21 healthy older adults (65.7 ± 5 yr), we measured contemporaneously noninvasive indexes of the overall speed of adjustment of the oxidative metabolism (i.e., pulmonary V̇o2 kinetics), of the bulk O2 delivery (i.e., cardiac output), and of the rate of muscle deoxygenation (i.e., deoxygenated hemoglobin, HHb) during moderate-intensity step transitions, either with (ModB) or without (ModA) prior PE. The local matching of O2 delivery to utilization was evaluated by the ΔHHb/ΔV̇o2 ratio index. The overall speed of adjustment of the V̇o2 kinetics was significantly increased in ModB compared with ModA ( P < 0.05). On the contrary, the kinetics of cardiac output was unaffected by PE. At the muscle level, ModB was associated with a significant reduction of the “overshoot” in the ΔHHb/ΔV̇o2 ratio compared with ModA ( P < 0.05), suggesting an improved O2 delivery. Our data are compatible with the hypothesis that, in older adults, PE, prior to moderate-intensity exercise, beneficially affects the speed of adjustment of oxidative metabolism due to an acute improvement of the local matching of O2 delivery to utilization.
Humoral regulation of heart rate during digestion in pythons (Python molurusandPython regius)
Authors: Enok Sanne , Simonsen Lasse Stærdal , Pedersen Signe Vesterskov , Wang Tobias , Skovgaard Nini
Published: March 2012

Pythons exhibit a doubling of heart rate when metabolism increases several times during digestion. Pythons, therefore, represent a promising model organism to study autonomic cardiovascular regulation during the postprandial state, and previous studies show that the postprandial tachycardia is governed by a release of vagal tone as well as a pronounced stimulation from nonadrenergic, noncholinergic (NANC) factors. Here we show that infusion of plasma from digesting donor pythons elicit a marked tachycardia in fasting snakes, demonstrating that the NANC factor resides in the blood. Injections of the gastrin and cholecystokinin receptor antagonist proglumide had no effect on double-blocked heart rate or blood pressure. Histamine has been recognized as a NANC factor in the early postprandial period in pythons, but the mechanism of its release has not been identified. Mast cells represent the largest repository of histamine in vertebrates, and it has been speculated that mast cells release histamine during digestion. Treatment with the mast cell stabilizer cromolyn significantly reduced postprandial heart rate in pythons compared with an untreated group but did not affect double-blocked heart rate. While this study indicates that histamine induces postprandial tachycardia in pythons, its release during digestion is not stimulated by gastrin or cholecystokinin nor is its release from mast cells a stimulant of postprandial tachycardia.
Object representation and distance encoding in three-dimensional environments by a neural circuit in the visual system of the blowfly
Authors: Liang Pei , Heitwerth Jochen , Kern Roland , Kurtz Rafael , Egelhaaf Martin
Published: March 2012

Three motion-sensitive key elements of a neural circuit, presumably involved in processing object and distance information, were analyzed with optic flow sequences as experienced by blowflies in a three-dimensional environment. This optic flow is largely shaped by the blowfly's saccadic flight and gaze strategy, which separates translational flight segments from fast saccadic rotations. By modifying this naturalistic optic flow, all three analyzed neurons could be shown to respond during the intersaccadic intervals not only to nearby objects but also to changes in the distance to background structures. In the presence of strong background motion, the three types of neuron differ in their sensitivity for object motion. Object-induced response increments are largest in FD1, a neuron long known to respond better to moving objects than to spatially extended motion patterns, but weakest in VCH, a neuron that integrates wide-field motion from both eyes and, by inhibiting the FD1 cell, is responsible for its object preference. Small but significant object-induced response increments are present in HS cells, which serve both as a major input neuron of VCH and as output neurons of the visual system. In both HS and FD1, intersaccadic background responses decrease with increasing distance to the animal, although much more prominently in FD1. This strong dependence of FD1 on background distance is concluded to be the consequence of the activity of VCH that dramatically increases its activity and, thus, its inhibitory strength with increasing distance.
The influence of surround suppression on adaptation effects in primary visual cortex
Authors: Wissig Stephanie C. , Kohn Adam
Published: March 2012

Adaptation, the prolonged presentation of stimuli, has been used to probe mechanisms of visual processing in physiological, imaging, and perceptual studies. Previous neurophysiological studies have measured adaptation effects by using stimuli tailored to evoke robust responses in individual neurons. This approach provides an incomplete view of how an adapter alters the representation of sensory stimuli by a population of neurons with diverse functional properties. We implanted microelectrode arrays in primary visual cortex (V1) of macaque monkeys and measured orientation tuning and contrast sensitivity in populations of neurons before and after prolonged adaptation. Whereas previous studies in V1 have reported that adaptation causes stimulus-specific suppression of responsivity and repulsive shifts in tuning preference, we have found that adaptation can also lead to response facilitation and shifts in tuning toward the adapter. To explain this range of effects, we have proposed and tested a simple model that employs stimulus-specific suppression in both the receptive field and the spatial surround. The predicted effects on tuning depend on the relative drive provided by the adapter to these two receptive field components. Our data reveal that adaptation can have a much richer repertoire of effects on neuronal responsivity and tuning than previously considered and suggest an intimate mechanistic relationship between spatial and temporal contextual effects.
Similar muscles contribute to horizontal and vertical acceleration of center of mass in forward and backward walking: implications for neural control
Authors: Jansen Karen , De Groote Friedl , Massaad Firas , Meyns Pieter , Duysens Jacques , Jonkers Ilse
Published: March 2012

Leg kinematics during backward walking (BW) are very similar to the time-reversed kinematics during forward walking (FW). This suggests that the underlying muscle activation pattern could originate from a simple time reversal, as well. Experimental electromyography studies have confirmed that this is the case for some muscles. Furthermore, it has been hypothesized that muscles showing a time reversal should also exhibit a reversal in function [from accelerating the body center of mass (COM) to decelerating]. However, this has not yet been verified in simulation studies. In the present study, forward simulations were used to study the effects of muscles on the acceleration of COM in FW and BW. We found that a reversal in function was indeed present in the muscle control of the horizontal movement of COM (e.g., tibialis anterior and gastrocnemius). In contrast, muscles' antigravity contributions maintained their function for both directions of movement. An important outcome of the present study is therefore that similar muscles can be used to achieve opposite functional demands at the level of control of the COM when walking direction is reversed. However, some muscles showed direction-specific contributions (i.e., dorsiflexors). We concluded that the changes in muscle contributions imply that a simple time reversal would be insufficient to produce BW from FW. We therefore propose that BW utilizes extra elements, presumably supraspinal, in addition to a common spinal drive. These additions are needed for propulsion and require a partial reconfiguration of lower level common networks.
Simulation of Thermal Flow Problems via a Hybrid Immersed Boundary‐Lattice Boltzmann Method
Authors: Wu J. , Shu C. , Zhao N.
Published: March 2012

A hybrid immersed boundary‐lattice Boltzmann method (IB‐LBM) is presented in this work to simulate the thermal flow problems. In current approach, the flow field is resolved by using our recently developed boundary condition‐enforced IB‐LBM (Wu and Shu, (2009)). The nonslip boundary condition on the solid boundary is enforced in simulation. At the same time, to capture the temperature development, the conventional energy equation is resolved. To model the effect of immersed boundary on temperature field, the heat source term is introduced. Different from previous studies, the heat source term is set as unknown rather than predetermined. Inspired by the idea in (Wu and Shu, (2009)), the unknown is calculated in such a way that the temperature at the boundary interpolated from the corrected temperature field accurately satisfies the thermal boundary condition. In addition, based on the resolved temperature correction, an efficient way to compute the local and average Nusselt numbers is also proposed in this work. As compared with traditional implementation, no approximation for temperature gradients is required. To validate the present method, the numerical simulations of forced convection are carried out. The obtained results show good agreement with data in the literature.
Will theAmaranthus tuberculatusResistance Mechanism to PPO-Inhibiting Herbicides Evolve in OtherAmaranthusSpecies?
Authors: Riggins Chance W. , Tranel Patrick J.
Published: March 2012

Resistance to herbicides that inhibit protoporphyrinogen oxidase (PPO) has been slow to evolve and, to date, is confirmed for only four weed species. Two of these species are members of the genusAmaranthusL. Previous research has demonstrated that PPO-inhibitor resistance inA. tuberculatus(Moq.) Sauer, the first weed to have evolved this type of resistance, involves a unique codon deletion in thePPX2gene. Our hypothesis is thatA. tuberculatusmay have been predisposed to evolving this resistance mechanism due to the presence of a repetitive motif at the mutation site and that lack of this motif in other amaranth species is why PPO-inhibitor resistance has not become more common despite strong herbicide selection pressure. Here we investigate inter- and intraspecific variability of thePPX2gene—specifically exon 9, which includes the mutation site—in ten amaranth species via sequencing and a PCR-RFLP assay. Few polymorphisms were observed in this region of the gene, and intraspecific variation was observed only inA. quitensis. However, sequencing revealed two distinct repeat patterns encompassing the mutation site. Most notably,A. palmeriS. Watson possesses the same repetitive motif found inA. tuberculatus. We thus predict thatA. palmeriwill evolve resistance to PPO inhibitors via the samePPX2codon deletion that evolved inA. tuberculatus.
Implementation of a Probabilistic Structural Health Monitoring Method on a Highway Bridge
Authors: Scianna Adam , Jiang Zhaoshuo , Christenson Richard , DeWolf John
Published: March 2012

This paper describes the application of a probabilistic structural health monitoring (SHM) method to detect global damage in a highway bridge in Connecticut. The proposed method accounts for the variability associated with environmental and operational conditions. The bridge is a curved three-span steel dual-box girder bridge located in Hartford, Connecticut. The bridge, monitored since Fall 2001, experienced a period of settling in the Winter of 2002-2003. While this change was not associated with structural damage, it was observed in a permanent rotation of the bridge superstructure. Three damage measures are identified in this study: the value of fundamental natural frequency determined from peak picking of autospectral density functions of the bridge acceleration measurements; the magnitude of the peak acceleration measured during a truck crossing; the magnitude of the tilt measured at 10-minute intervals. These damage measures, including thermal effects, are shown to be random variables and associatedPvalues are calculated to determine if the current probability distributions are the same as the distributions of the baseline bridge data from 2001. Historical data measured during the settling of the bridge is used to verify the performance of the bridge, and the field implementation of the proposed method is described.
Synchronization of Two Rank‐One Chaotic Systems without and with Delay via Linear Delayed Feedback Control
Authors: Fang Hui
Published: March 2012

This paper illustrates the presence of chaos in rank‐one chaotic systems with delay via a binary
test (called 0‐1 test) for chaos. Chaotic synchronization between two rank‐one chaotic systems
without and with delay is achieved by means of Lyapunov functional and linear delayed feedback
control method. Numerical simulations are implemented to verify the effectiveness of the proposed
chaos synchronization scheme.
Materials and Devices Research of PPV‐ZnO Nanowires for Heterojunction Solar Cells
Authors: Xiao-Zhou Zhang , Xi-Gao Jian , Li-Wu Zu
Published: March 2012

Bulk heterojunction photovoltaic devices, which use the conjugated polymer poly(2‐methoxyl‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene) (MEH‐PPV) as the electron donor and crystalline ZnO nanowires as the electron acceptor, have been studied in this work. The ZnO nanowires were prepared through a chemical vapor deposition mechanism. The dissolved MEH‐PPV polymer was spin‐coated onto the nanowires. The scanning electron microscope images showed that the ZnO nanowires were covered with a single layer of the polymer, and these materials were used to design a heterojunction solar cell. This solar cell displayed improved performance compared with the devices that were made from only the MEH‐PPV polymer. This observed improvement is correlated with the improved electron transport that is perpendicular to the plane of the film. A solar power conversion efficiency of 1.37% was achieved under an AM1.5 illumination.
Role of Money in Smaller Pacific Island Countries
Authors: Jayaraman T. K. , Choong Chee-Keong
Published: March 2012

Pacific island countries (PICs), which attained political independence, are open economies with very small manufacturing base and narrow range of exports of copra and tuna. They are highly dependent on imports ranging from food and mineral fuels to intermediate and capital goods and transport machinery. Four of the 14 PICs, namely Samoa, Solomon Islands, Tonga, and Vanuatu, have independent currencies with usual paraphernalia of central banks under fixed exchange rate regimes. Their financial sectors are small and with undeveloped money and capital markets. The nominal exchange rate as an anchor has served the four PICs well by keeping inflation low. The objective of the paper is to investigate whether money has played any significant part in output growth as well as determination of prices in PICs. The findings are that broad money (M2) and exchange rate have a long run as well as short-run casual relationship with both output and prices in all PICs.
Alzheimer's Disease and the Amyloid Cascade Hypothesis: A Critical Review
Authors: Reitz Christiane
Published: March 2012

Since 1992, the amyloid cascade hypothesis has played the prominent role in explaining the etiology and pathogenesis of Alzheimer's disease (AD). It proposes that the deposition of β-amyloid (Aβ) is the initial pathological event in AD leading to the formation of senile plaques (SPs) and then to neurofibrillary tangles (NFTs), neuronal cell death, and ultimately dementia. While there is substantial evidence supporting the hypothesis, there are also limitations: (1) SP and NFT may develop independently, and (2) SPs and NFTs may be the products rather than the causes of neurodegeneration in AD. In addition, randomized clinical trials that tested drugs or antibodies targeting components of the amyloid pathway have been inconclusive. This paper provides a critical overview of the evidence for and against the amyloid cascade hypothesis in AD and provides suggestions for future directions.
What Explains Forest Grouse Mortality: Predation Impacts of Raptors, Vole Abundance, or Weather Conditions?
Authors: Tornberg Risto , Reif Vitali , Korpimäki Erkki
Published: March 2012

We investigated predation rates of black grouse chicks during 1985–2007 in two localities in western Finland in light of three predation hypothesis: The Alternative Prey Hypothesis (APH) stating that vole-eating generalist predators cause a collapse in grouse reproduction after voles’ decline, the Main Prey Hypothesis (MPH), where grouse specialised predators by a lagged response cause an inversely density dependent predation for prey and the Predation Facilitation Hypothesis (PFH), where generalist and specialist predators act in concert. We also studied the effect of weather on grouse reproduction. We found that buzzard predation alone did not support APH, but did so when combined with goshawk predation. Kill rate by goshawks showed a linear response for black grouse chicks but was not density dependent. It, however, explained the losses of chicks but not their autumn density. Combined density of chicks with adults correlated with vole index in the latter study period (since 1994), thus, giving some support for APH. Weather seemed to have no effect on black grouse reproduction. Although buzzards and goshawks took, on average, only 10% of hatched grouse chicks we conclude that the among-year survival pattern of juvenile forest grouse may largely be determined by raptor predation.
LSVT LOUD and LSVT BIG: Behavioral Treatment Programs for Speech and Body Movement in Parkinson Disease
Authors: Fox Cynthia , Ebersbach Georg , Ramig Lorraine , Sapir Shimon
Published: March 2012

Recent advances in neuroscience have suggested that exercise-based behavioral treatments may improve function and possibly slow progression of motor symptoms in individuals with Parkinson disease (PD). The LSVT (Lee Silverman Voice Treatment) Programs for individuals with PD have been developed and researched over the past 20 years beginning with a focus on the speech motor system (LSVT LOUD) and more recently have been extended to address limb motor systems (LSVT BIG). The unique aspects of the LSVT Programs include the combination of (a) an exclusive target on increasing amplitude (loudness in the speech motor system; bigger movements in the limb motor system), (b) a focus on sensory recalibration to help patients recognize that movements with increased amplitude are within normal limits, even if they feel “too loud” or “too big,” and (c) training self-cueing and attention to action to facilitate long-term maintenance of treatment outcomes. In addition, the intensive mode of delivery is consistent with principles that drive activity-dependent neuroplasticity and motor learning. The purpose of this paper is to provide an integrative discussion of the LSVT Programs including the rationale for their fundamentals, a summary of efficacy data, and a discussion of limitations and future directions for research.
Numerical Simulation of the Effect of Heater Position on the Oxygen Concentration in the CZ Silicon Crystal Growth Process
Authors: Teng Ying-Yang , Chen Jyh-Chen , Lu Chung-Wei , Huang Cheng-Chuan , Wun Wan-Ting , Chen Hsueh-I , Chen Chi-Yung , Lan Wen-Chieh
Published: March 2012

We perform numerical simulations to analyze the effect of the position of the heater on the thermal and flow fields and the oxygen concentration distribution during the industrial Cz silicon crystal growth process. The amount of oxygen released from the silica crucible to the silicon melt during the growth process can be lowered by adjusting the heater position to decrease the temperature on the crucible wall. During growth of the crystal body, there is a significant decrease in the gradient of the oxygen concentration along the melt-crystal interface due to the stronger Taylor-Proudman vortex, which is generated by the crucible and crystal rotation. There is a significant reduction in the average oxygen concentration at the melt-crystal interface for longer crystal lengths because of the lower wall temperature, smaller contact surface between the crucible wall and the melt and the stronger Taylor-Proudman vortex.
Evaluation of Osteoconductive and Osteogenic Potential of a Dentin-Based Bone Substitute Using a Calvarial Defect Model
Authors: Hussain Ibrahim , Moharamzadeh Keyvan , Brook Ian M. , José de Oliveira Neto Patrício , Salata Luiz A.
Published: March 2012

The aim of this study was to assess the osteoconductive and osteogenic properties of processed bovine dentin using a robust rabbit calvarial defect model. In total, 16 New Zealand White rabbits were operated to create three circular defects in the calvaria. One defect was left unfilled, one filled with collected autogenous bone, and the third defect was filled with the dentin-based bone substitute. Following surgery and after a healing period of either 1 or 6 weeks, a CT scan was obtained. Following sacrificing, the tissues were processed for histological examination. The CT data showed the density in the area grafted with the dentin-based material was higher than the surrounding bone and the areas grafted with autologous bone after 1 week and 6 weeks of healing. The area left unfilled remained an empty defect after 1 week and 6 weeks. Histological examination of the defects filled with the dentin product after 6 weeks showed soft tissue encapsulation around the dentin particles. It can be concluded that the rabbit calvarial model used in this study is a robust model for the assessment of bone materials. Bovine dentin is a biostable material; however, it may not be suitable for repairing large 4-wall defects.
Dendritic Cells The Tumor Microenvironment and the Challenges for an Effective Antitumor Vaccination
Authors: Benencia Fabian , Sprague Leslee , McGinty John , Pate Michelle , Muccioli Maria
Published: March 2012

Many clinical trials have been carried out or are in progress to assess the therapeutic potential of dendritic-cell- (DC-) based vaccines on cancer patients, and recently the first DC-based vaccine for human cancer was approved by the FDA. Herewith, we describe the general characteristics of DCs and different strategies to generate effective antitumor DC vaccines. In recent years, the relevance of the tumor microenvironment in the progression of cancer has been highlighted. It has been shown that the tumor microenvironment is capable of inactivating various components of the immune system responsible for tumor clearance. In particular, the effect of the tumor microenvironment on antigen-presenting cells, such as DCs, does not only render these immune cells unable to induce specific immune responses, but also turns them into promoters of tumor growth. We also describe strategies likely to increase the efficacy of DC vaccines by reprogramming the immunosuppressive nature of the tumor microenvironment.
A Concise Review of Amyloidosis in Animals
Authors: Woldemeskel Moges
Published: March 2012

Amyloidosis refers to a group of protein misfolding diseases characterized by deposition of a particular amyloid protein in various organs and tissues of animals and humans. Various types and clinical forms of amyloidosis, in which the pathology and pathogenesis is diverse depending upon the underlying causes and species affected, are reported in domestic and wild animals. The clinical findings are also quite variable consequent to the variation of the tissues and organs involved and the extent of functional disruption of the affected organs in various animal species. The affected organs may be enlarged and exhibit variable pallor grossly, or the amyloid deposit may be discernible only after microscopic examination of the affected tissues. Amyloid appears as a pale eosinophilic homogenous extracellular deposit in tissues. However, microscopic examination and Congo red staining with green birefringence under polarized light are needed to confirm amyloid and differentiate it from other apparently similar extracellular deposits such as collagen and fibrin. Identifying the type of amyloid deposit needs immunohistochemical staining, ultrastructural characterization of the amyloid fibril, and if feasible also genetic studies of the involved species for clinical and prognostic purposes. This paper provides a concise review of the occurrence of amyloidosis in domestic and wild animals.
The Great Mimicker: Zona Zoster at the Mastectomy Site Causing Contralateral Intramammary Lymph Node Enlargement
Authors: Aksoy Ozcan Umit , Tezcanli Evrim , Yildirim Yesim , Garipagaoglu Melahat
Published: March 2012

Zona zoster is rarely observed in patients with malignancy; when present, it follows a dermatomal fashion. Involvement of widely separated regions is very rare. Hereby, zona zoster causing enlarged intramammary lymph nodes (IMLN) in the opposite breast is reported for the first time in literature. The masses were hypoechoic on US with no hilum and hypervascular on color Doppler US. MRI showed hypointense masses with type 3 time-intensity curve and adjacent vessel sign. The complete regression of the nodes after the antiviral therapy confirmed the diagnosis. In breast cancer patients, IMLN enlargements may mimic breast cancer metastasis, and zona zoster infection of the mastectomy site may present with contralateral IMLN enlargement due to altered lymphatic drainage. When breast US is not sufficient for the differential diagnosis, breast MRI may warrant proper diagnosis, and prevent unnecessary biopsies. Antiviral treatment with followup would be sufficient for management.
Throughput Analysis for a High-Performance FPGA-Accelerated Real-Time Search Application
Authors: Vanderbauwhede Wim , Chalamalasetti S. R. , Margala M.
Published: March 2012

We propose an FPGA design for the relevancy computation part of a high-throughput real-time search application. The application matches terms in a stream of documents against a static profile, held in off-chip memory. We present a mathematical analysis of the throughput of the application and apply it to the problem of scaling the Bloom filter used to discard nonmatches.
Measurement of Inhaled Corticosteroid Adherence in Inner-City, Minority Children with Persistent Asthma by Parental Report and Integrated Dose Counter
Authors: Reznik Marina , Ozuah Philip O.
Published: March 2012

Parents often overreport adherence to asthma treatment regimens making accurate assessment of medication adherence in clinical practice difficult. This study was conducted to compare two adherence assessment methods clinicians may choose from when assessing patient inhaled corticosteroid (ICS) adherence: parental report and dose counter measurements of metered-dose inhaler (MDI) actuation. Participants included children (N=50) with persistent asthma and their parents (N=50). At enrollment, children received a new, marked ICS at the dose prescribed by their physician. Thirty days following enrollment, we measured ICS adherence by parental report and objectively, with a dose counter. Parental report overestimated ICS adherence when compared to dose counter. We found a statistically significant overall difference between parental report and objectively measured adherence. A dose counter that most ICS inhalers are equipped with may be a more reliable alternative measure of ICS adherence in a clinical practice setting.
Effect of the Substrate Movement on the Optical Properties of ZnO Thin Films Deposited by Ultrasonic Spray Pyrolysis
Authors: Gungor Ebru , Gungor Tayyar
Published: March 2012

Using a modified ultrasonic spray pyrolysis (USP) system, ZnO thin films were deposited on the substrate moved back and forth (ZO1) and rotated (ZO3) as well as fixed (ZO2) in the conventional USP technique. Prepared thin films are pure ZnO with a preferred crystalline orientation of (0 0 2) in the hexagonal wurtzite structure. Diffraction angle shift implies a decrease lattice parameter alongc-axis anda-axis 0.2% and 0.3%, respectively. Maximum strain has been found for ZO1 which is about (−) 0.17%. These strain values show that presence of compressive strain due to moving substrates as depositing ZnO films. The film deposition process on the rotated quartz substrate is provided to obtain the thinner film. The grain size and root-mean- square value of roughness increase with thickness. Strong UV emission was observed at ∼390 nm assigned to the band gap transition from photoluminescence measurements. Energy shifted about 39 meV for ZO3 sample with respect to that of ZO2 film deposited in conventional USP system. This behaviour is confirmed with (002) diffraction peak shifting. So, the compressed lattice will provide a wider band gap for these films.E2phonon frequency values have not given a considerable shifting.
On a Generalized Hyers‐Ulam Stability of Trigonometric Functional Equations
Authors: Chung Jaeyoung , Chang Jeongwook
Published: March 2012

Let G be an Abelian group, let ℂ be the field of complex numbers, and let f, g : G → ℂ. We consider the generalized Hyers‐Ulam stability for a class of trigonometric functional inequalities, |f(x − y) − f(x)g(y) + g(x)f(y)| ≤ ψ(y),  |g(x − y) − g(x)g(y) − f(x)f(y)| ≤ ψ(y), where ψ : G → ℝ is an arbitrary nonnegative function.
Evaluation of a Brief Intervention to Improve the Nursing Care of Young Children in a High HIV and AIDS Setting
Authors: Richter Linda M. , Rochat Tamsen J. , Hsiao Celia , Zuma Thembelihle H.
Published: March 2012

The HIV epidemic in South Africa is putting great strain on health services, including the inpatient care of young children. Caregivers and young children (107 pairs) and 17 nurses participated in an intervention to improve the care of young children in hospital in a high HIV and AIDS setting. The intervention addressed caregiver expectations about admission and treatment, responsive feeding, coping with infant pain and distress, assistance with medical procedures, and preparation for discharge and home care. Following a preparatory and piloting phase, measures of nurse burnout, caregiver physical and emotional well-being, and caregiver-child interaction were made before and after intervention. No changes were found between before and after intervention on assessments of caregiver wellbeing. However, mothers in the postintervention phase rated nurses as more supportive; mother-child interaction during feeding was more relaxed and engaged, and babies were less socially withdrawn. While the intervention proved useful in improving certain outcomes for children and their caregivers, it did not address challenging hospital and ward administration or support needed by caregivers at home following discharge. To address the latter need, the intervention has been extended into the community through home-based palliative care and support.
A Platoon Dispersion Model Based on a Truncated Normal Distribution of Speed
Authors: Wei Ming , Jin Wenzhou , Shen Lvou
Published: March 2012

Understanding platoon dispersion is critical for the coordination of traffic signal control in an urban traffic network. Assuming that platoon speed follows a truncated normal distribution, ranging from minimum speed to maximum speed, this paper develops a piecewise density function that describes platoon dispersion characteristics as the platoon moves from an upstream to a downstream intersection. Based on this density function, the expected number of cars in the platoon that pass the downstream intersection, and the expected number of cars in the platoon that do not pass the downstream point are calculated. To facilitate coordination in a traffic signal control system, dispersion models for the front and the rear of the platoon are also derived. Finally, a numeric computation for the coordination of successive signals is presented to illustrate the validity of the proposed model.