bluuebunny/crossref_metadata_2025 huggingface dataset:
A NEW APPROACH TO THE TREATMENT OF SEPARATRIX CHAOS
Authors: SOSKIN STANISLAV M. , MANNELLA RICCARDO , YEVTUSHENKO OLEG M. , KHOVANOV IGOR A. , McCLINTOCK PETER V. E.
Published: April 2012

We review an approach to separatrix chaos that has allowed us to solve some significant problems by: (i) finding analytically the maximum width of the chaotic layer, a problem that lay unsolved for 40 years, and showing that the maximum may be much larger than had previously been assumed; (ii) describing the drastic facilitation of the onset of global chaos between neighboring separatrices, a phenomenon discovered eight years ago.
QUANTUM BROWNIAN MOTION IN A PERIODIC POTENTIAL: THE PATH INTEGRAL FOR A SUPER-OHMIC BATH
Authors: ARRAYÁS M.
Published: April 2012

The problem of a Brownian particle in a super-Ohmic bath under the effect of a periodic tilted potential is studied. The quantum dissipative dynamics is formulated in terms of the influence functional and the path integrals are calculated explicitly and analytically.
COHERENCE BETWEEN FLUCTUATIONS IN BLOOD FLOW AND OXYGEN SATURATION
Authors: BERNJAK ALAN , STEFANOVSKA ANETA , McCLINTOCK PETER V. E. , OWEN-LYNCH P. JANE , CLARKSON PETER B. M.
Published: April 2012

We have determined the wavelet phase coherence between simultaneously recorded microvascular blood flow and oxygen saturation signals from 88 healthy subjects, thus enabling us to study their common fluctuations. Measurements were taken for 30 min from the arm and leg, at two depths. In the skin, blood flow and oxygen saturation were found to be coherent both at the cardiac frequency and below 0.1 Hz down to about 0.01 Hz. Coherence in the arm extends to lower frequencies than that in the leg. From the deeper recordings, no coherence was found on either limb. The existence of coherence between skin blood flow and oxygen saturation demonstrates causal connections between them within certain frequency ranges. The method has yielded the first detailed insight into the dynamics of blood oxygenation.
MODELING OF HUMAN BAROREFLEX: CONSIDERATIONS ON THE SEIDEL–HERZEL MODEL
Authors: DUGGENTO ANDREA , TOSCHI NICOLA , GUERRISI MARIA
Published: April 2012

We provide some comments on the Seidel–Herzel model of the human baroreflex feedback control mechanism, and on how it has been used in literature to mimic observed features of in vivo heart rate data. We demonstrate that the potential of reparameterizing of this model in order to reproduce human physiology has not been fully exploited, and point out several potential pitfalls when trying to do so.
FLUCTUATIONS AND INTERACTIONS BETWEEN BRAIN WAVES DURING DEEP AND SHALLOW ANESTHESIA
Authors: MUSIZZA B. , BAJROVIĆ F. F. , PETROVČIČ J. , STEFANOVSKA A. , RIBARIČ S.
Published: April 2012

Using gold plated electrodes, inserted into the rat's head above the dura of the left and right parietal cortex, we recorded EEG during deep and shallow anesthesia with either pentobarbital (PB) or ketamine-xylazine (KX). The fluctuations in time series were then analyzed using wavelet transforms and the spectral power was determined within 7 frequency intervals (slow wave 2, S2, 0.0067–0.0167 Hz; slow wave 1, S1, 0.02–0.19 Hz; δ, 0.2–3.9 Hz; θ, 4–7.9 Hz; α, 8–12.9 Hz; β, 13–24.9 Hz and γ, 25–34.9 Hz). In addition, the coupling strengths between individual oscillatory components during deep and shallow anesthesia were evaluated for both anesthetics. We show specific changes for both anesthetics indicating that during deep anesthesia PB reduces high and low frequency activity (0.2–35 Hz) and enhances coupling especially between δ, θ and α waves, while KX reduces low frequency activity (0.005 to 0.2 Hz) and enhances coupling between frequency waves α, β and γ. Our results, using two anesthetics known to block different ion channels, provide an insight into brain dynamics and could have wide implications in creating biomarkers for detecting various neurophysiological modifications, such as in Alzheimer and Parkinson's disease or Autism spectrum disorder, as well as in providing more realistic models of brain dynamics.
Lack of protein kinase C-α leads to impaired urine concentrating ability and decreased aquaporin-2 in angiotensin II-induced hypertension
Authors: Thai Tiffany L. , Blount Mitsi A. , Klein Janet D. , Sands Jeff M.
Published: April 2012

Regulation of water and urea transport in the inner medullary collecting duct is essential for urine concentration. Aquaporin (AQP)2 water channels and urea transporter (UT)-A1 are inserted into the apical membrane upon phosphorylation of the channels to allow the transcellular movement of water and urea. Since ANG II activates PKC in many cell types, we tested the hypothesis that ANG II-induced regulation of water and urea transport is mediated by PKC. Osmotic minipumps delivered ANG II to wild-type (WT) or PKC-α−/−mice for 7 days. Inner medullas were harvested, and protein abundance was determined by immunoblot. ANG II increased systolic blood pressure to a similar degree in WT and PKC-α−/−mice. ANG II had no effect on the urine output of WT mice but increased that of PKC-α−/−mice. In accordance with observed differences in urine output, AQP2 abundance was unchanged in ANG II-treated WT animals but was decreased in PKC-α−/−mice. No change in membrane accumulation was seen. Phosphorylation of the cAMP-induced transcription factor CREB was decreased in PKC-α−/−mice in response to ANG II with no change in overall CREB abndance. ANG II did not alter the abundance of UT-A1 protein in WT or PKC-α−/−mice. Phosphorylation and overall abundance of tonicity-responsive enhancer-binding protein, a transcription factor that regulates UT-A1, were also unaltered by ANG II in either group. We conclude that PKC-α protects against ANG II-induced decreases in urine concentrating ability by maintaining AQP2 levels through CREB phosphorylation.
Touch responsiveness in zebrafish requires voltage-gated calcium channel 2.1b
Authors: Low Sean E. , Woods Ian G. , Lachance Mathieu , Ryan Joel , Schier Alexander F. , Saint-Amant Louis
Published: April 2012

The molecular and physiological basis of the touch-unresponsive zebrafish mutant fakir has remained elusive. Here we report that the fakir phenotype is caused by a missense mutation in the gene encoding voltage-gated calcium channel 2.1b ( CACNA1Ab). Injection of RNA encoding wild-type CaV2.1 restores touch responsiveness in fakir mutants, whereas knockdown of CACNA1Ab via morpholino oligonucleotides recapitulates the fakir mutant phenotype. Fakir mutants display normal current-evoked synaptic communication at the neuromuscular junction but have attenuated touch-evoked activation of motor neurons. NMDA-evoked fictive swimming is not affected by the loss of CaV2.1b, suggesting that this channel is not required for motor pattern generation. These results, coupled with the expression of CACNA1Ab by sensory neurons, suggest that CaV2.1b channel activity is necessary for touch-evoked activation of the locomotor network in zebrafish.
Reversal of quinpirole inhibition of ventral tegmental area neurons is linked to the phosphatidylinositol system and is induced by agonists linked to Gq
Authors: Nimitvilai Sudarat , McElvain Maureen A. , Arora Devinder S. , Brodie Mark S.
Published: April 2012

Putative dopaminergic (pDAergic) ventral tegmental area neurons play an important role in brain pathways related to addiction. Extended exposure of pDAergic neurons to moderate concentrations of dopamine (DA) results in a time-dependent decrease in sensitivity of pDAergic neurons to DA inhibition, a process called dopamine inhibition reversal (DIR). We have shown that DIR is mediated by phospholipase C and conventional protein kinase C through concurrent stimulation of D2 and D1-like receptors. In the present study, we further characterized this phenomenon by using extracellular recordings in brain slices to examine whether DIR is linked to phosphatidylinositol (PI) or adenylate cyclase (AC) second-messenger pathways. A D1-like dopaminergic agonist associated with PI turnover (SKF83959), but not one linked to AC (SKF83822), promoted reversal of inhibition produced by quinpirole, a dopamine D2-selective agonist. Other neurotransmitter receptors linked to PI turnover include serotonin 5-HT2, α1-adrenergic, neurotensin, and group I metabotropic glutamate (mGlu) receptors. Both serotonin and neurotensin produced significant reversal of quinpirole inhibition, but agonists of α1-adrenergic and group I mGlu receptors failed to significantly reverse quinpirole inhibition. These results indicate that some agonists that stimulate PI turnover can facilitate desensitization of D2 receptors but that there may be other factors in addition to PI that control that interaction.
The Protective Effect of Yi Shen Juan Bi Pill in Arthritic Rats with Castration-Induced Kidney Deficiency
Authors: Zhao Hongyan , Li Jian , He Xiaojuan , Lu Cheng , Xiao Cheng , Niu Xuyan , Zhao Ning , Ju Dahong , Lu Aiping
Published: April 2012

Androgens have been linked to the onset, severity, and progression of rheumatoid arthritis (RA). In traditional Chinese medicine (TCM), the most common pattern in RA is kidney deficiency, which partly corresponds to a low sex hormone state. In this study, TCM kidney deficiency was induced in male Sprague-Dawley rats with castration surgery, and a TCM preparation, Yi Shen Juan Bi Pill (YJB), was used to treat collagen induced arthritis (CIA) rats with castration. Metabolomic technique was used to evaluate the pharmacological mechanism in castrated CIA rats treated by YJB. The results showed that castration significantly increased the severity of the arthritis in rats but was ameliorated by YJB. Its pharmacological mechanism was partially associated with lipid metabolites involving free fatty acid (FFA) and lysophosphatidylcholine (LPC).In conclusion, the experimental results demonstrate the protective effect of YJB on the TCM kidney deficiency pattern induced by androgen deficiency in CIA rats and support that YJB should be used for the clinical treatment of RA with TCM kidney deficiency pattern.
On Semilinear Integro‐Differential Equations with Nonlocal Conditions in Banach Spaces
Authors: Dinh Ke Tran , Obukhovskii Valeri , Wong Ngai-Ching , Yao Jen-Chih
Published: April 2012

We study the abstract Cauchy problem for a class of integrodifferential
equations in a Banach space with nonlinear perturbations and nonlocal conditions.
By using MNC estimates, the existence and continuous dependence results are proved.
Under some additional assumptions, we study the topological structure of the solution
set.
Unsupervised Two-Way Clustering of Metagenomic Sequences
Authors: Prabhakara Shruthi , Acharya Raj
Published: April 2012

A major challenge facing metagenomics is the development of tools for the characterization of functional and taxonomic content of vast amounts of short metagenome reads. The efficacy of clustering methods depends on the number of reads in the dataset, the read length and relative abundances of source genomes in the microbial community. In this paper, we formulate an unsupervised naive Bayes multispecies, multidimensional mixture model for reads from a metagenome. We use the proposed model to cluster metagenomic reads by their species of origin and to characterize the abundance of each species. We model the distribution of word counts along a genome as a Gaussian for shorter, frequent words and as a Poisson for longer words that are rare. We employ either a mixture of Gaussians or mixture of Poissons to model reads within each bin. Further, we handle the high-dimensionality and sparsity associated with the data, by grouping the set of words comprising the reads, resulting in a two-way mixture model. Finally, we demonstrate the accuracy and applicability of this method on simulated and real metagenomes. Our method can accurately cluster reads as short as 100 bps and is robust to varying abundances, divergences and read lengths.
3GPP Channel Model Emulation with Analysis of MIMO-LTE Performances in Reverberation Chamber
Authors: Arsalane Nabil , Mouhamadou Moctar , Decroze Cyril , Carsenat David , Garcia-Fernandez Miguel Angel , Monedière Thierry
Published: April 2012

Emulation methodology of multiple clusters channels for evaluating wireless communication devices over-the-air (OTA) performance is investigated. This methodology has been used along with the implementation of the SIMO LTE standard. It consists of evaluating effective diversity gain (EDG) level of SIMO LTE-OFDM system for different channel models according to the received power by establishing an active link between the transmitter and the receiver. The measurement process is set up in a Reverberation Chamber (RC). The obtained results are compared to the reference case of single input-single output (SISO) in order to evaluate the real improvement attained by the implemented system.
Evaluation of Hepatic Mitochondria and Hematological Parameters in Zidovudine-TreatedB6C3F1Mice
Authors: Desai Varsha G. , Lee Taewon , Moland Carrie L. , Branham William S. , Mittelstaedt Roberta A. , Lewis Sherry M. , Leakey Julian E. A. , Fuscoe James C.
Published: April 2012

The effects of 12-week exposure to zidovudine (AZT) at 400, 500, and 600 mg/kg/d were examined on expression of 542 mitochondria-related genes and mitochondrial DNA (mtDNA) copy number in the liver of male and female B6C3F1mice to understand mitochondrial role in sex-related differences in development of lactic acidosis. Plasma lactate levels and hematologic parameters were also examined. Results indicated increased red blood cell (RBC) count in vehicle-treated controls, whereas a dose-related decline in the RBC count was noted in AZT-treated mice compared to the basal levels before treatments began. These decreases were associated with significant dose-related increases in mean corpuscular volume and mean corpuscular hemoglobin levels. This effect was greater in AZT-treated females compared to males. In both sexes, 12-week AZT or vehicle exposure significantly reduced plasma lactate levels compared to the basal levels. Results also showed modest, but significant, changes in the expression of genes associated with apoptosis and lipid metabolism at 600 mg/kg/d AZT. Neither drug nor sex influenced hepatic mtDNA copy number. Altogether, 12-week AZT exposure as high as 600 mg/kg/d did not impair hepatic mitochondria or induce lactic acidosis in B6C3F1mice. However, AZT-mediated hematologic toxicity appeared to be greater in females compared to males.
Using Medical History Embedded in Biometrics Medical Card for User Identity Authentication: Privacy Preserving Authentication Model by Features Matching
Authors: Fong Simon , Zhuang Yan
Published: April 2012

Many forms of biometrics have been proposed and studied for biometrics authentication. Recently researchers are looking into longitudinal pattern matching that based on more than just a singular biometrics; data from user’s activities are used to characterise the identity of a user. In this paper we advocate a novel type of authentication by using a user’s medical history which can be electronically stored in a biometric security card. This is a sequel paper from our previous work about defining abstract format of medical data to be queried and tested upon authentication. The challenge to overcome is preserving the user’s privacy by choosing only the useful features from the medical data for use in authentication. The features should contain less sensitive elements and they are implicitly related to the target illness. Therefore exchanging questions and answers about a few carefully chosen features in an open channel would not easily or directly expose the illness, but yet it can verify by inference whether the user has a record of it stored in his smart card. The design of a privacy preserving model by backward inference is introduced in this paper. Some live medical data are used in experiments for validation and demonstration.
Overexpression of S6 Kinase 1 in Brain Tumours Is Associated with Induction of Hypoxia-Responsive Genes and Predicts Patients' Survival
Authors: Ismail Heba M.S.
Published: April 2012

mTOR/S6K pathway is a crucial regulator of cell growth and metabolism. Deregulated signalling via S6K has been linked to various human pathologies, including metabolic disorders and cancer. Many of the molecules signalling upstream of S6K have been shown to be either mutated or overexpressed in tumours, leading to S6K activation. The role of S6K1 in brain tumours is not fully investigated. In this study, we investigated the gene expression profile of S6 kinases in brain and CNS tumours using the publically available Cancer Microarray Database. We found that S6K1 but not S6K2 gene is overexpressed in brain tumours and this upregulation is associated with patients’ poor survival. Furthermore, we interrogated Oncomine database for the expression profile of hypoxia-induced genes using a literature-defined concept. This gene list included HIF1A, VEGFA, SOX4, SOX9, MMP2, and NEDD9. We show that those genes are upregulated in all brain tumour studies investigated. Additionally, we analysed the coexpression profile of S6K1 and hypoxia responsive genes. The analysis was done across 4 different brain studies and showed that S6K1 is co-overexpressed with several hypoxia responsive genes. This study highlights the possible role of S6K1 in brain tumour progression and prediction of patients’ survival. However, new epidemiological studies should be conducted in order to confirm these associations and to refine the role of S6K1 in brain tumours as a useful marker for patients’ survival.
The Th17/IL-23 Axis and Natural Immunity in Psoriatic Arthritis
Authors: Maeda Shinji , Hayami Yoshihito , Naniwa Taio , Ueda Ryuzo
Published: April 2012

Psoriatic arthritis (PsA) is a chronic inflammatory skin disease that causes enthesitis and destructive arthritis and significantly lowers patient quality of life. Recognition of the two target organs (the skin and joints) involved in the immunopathophysiology of PsA helped in elucidating the pathology of various systemic autoimmune diseases targeting multiple organs. Recent advances in immunology and genetics have made it clear that acquired immunity, especially that mediated by the Th17/IL-23 axis, plays an important role in the inflammatory pathology observed in psoriasis and PsA. Additionally, involvement of natural immunity has also been suggested. Microbial infection has been known to trigger psoriasis and PsA. Recent clinical studies using biopharmaceuticals, such as tumor-necrosis-factor- (TNF-)αinhibitors and IL-12/23 p40 antibodies, indicate that studies need not be based only on the immunological phenomena observed in PsA pathology since disease pathology can now be verified using human-based science. Considering this aspect, this paper discusses the immunopathology of PsA compared to psoriasis (cutaneous) and rheumatoid arthritis in humans and immunopathology of PsA with respect to the Th17/IL-23 axis and microbial infection.
Skin-Derived Precursor Cells as an In Vitro Modelling Tool for the Study of Type 1 Neurofibromatosis
Authors: Gutiérrez-Rivera Araika , Iribar Haizea , Tuneu Anna , Izeta Ander
Published: April 2012

The most characteristic feature of neurofibromatosis type 1 (NF1) is the development of neurofibromas. It has been suggested that these tumors are caused by somatic inactivation of the wild-typeNF1allele, but the cell that originally suffers this mutation remains controversial. Several lines of evidence support the clonal origin of these tumors, and it has been recently suggested that skin-derived precursor cells (SKPs) could be the cell of origin of dermal neurofibromas. Nullizygous (NF1−/−) SKPs do give rise to neurofibromas when transplanted to heterozygous mice. Moreover, a nullizygous population of cells that is S100βnegative is present in human neurofibromas, andNF1+/−multipotent progenitor cells are seemingly recruited to the tumor. This evidence supports the neurofibroma stem cell hypothesis and a putative involvement of SKPs in the aetiopathogenesis of the disease, suggesting that SKPs could become a valuable tool for the in vitro study of NF1.
Dexamethasone Resisted Podocyte Injury via Stabilizing TRPC6 Expression and Distribution
Authors: Yu Shengyou , Yu L.
Published: April 2012

TRPC6, a member of the canonical transient receptor potential channel (TRPC) subfamily, is an important cation selective ion channel on podocytes. Podocytes are highly differentiated cells located on the visceral face of glomerular basement membrane and featured by numerous foot processes, on which nephrin, podocin, and TRPC6 locate. Podocytes and the slit diaphragm (SD) between adjacent foot processes form a selective filtration barrier impermeable to proteins. TRPC6 is very critical for normal podocyte function. To investigate the function of TRPC6 in podocytes and its relation to proteinuria in kidney diseases, we over-expressed TRPC6 in podocytes by puromycin aminonucleoside (PAN) and observed the changes of foot processes, TRPC6 protein distribution, and mRNA expression. Accordingly, in this study, we further investigated the role of specific signaling mechanisms underlying the prosurvival effects of dexamethasone (DEX) on podocyte repair. Our results showed that podocytes processes of overexpressing TRPC6 were reduced remarkably. These changes could be rescued by DEX via blocking TRPC6 channel. Additionally, our results also showed an improvement in TRPC6 arrangement in the cells and decrease of mRNA expression and protein distribution. From these results, we therefore proposed that overexpression of TRPC6 in podocytes may be one of the fundamental changes relating to the dysfunction of the SD and proteinuria. DEX may be maintained the structure and function integrity of SD by blocking TRPC6 signal pathway and played an important role in mechanisms of anti-proteinuria.
Comparative Use of Soil Organic and Inorganic Amendments in Heavy Metals Stabilization
Authors: Branzini Agustina , Zubillaga Marta Susana
Published: April 2012

Remediation strategies are capable to mitigate negative effects of heavy metals (HMs) on soils. The distribution of cooper (Cu), zinc (Zn), and chromium (Cr) was evaluated in a contaminated soil after adding biosolid compost (BC) and phosphate fertilizer (PF). A greenhouse assay and sequential extraction procedure were performed to determine the fractionation of HM in contaminated and remediated soil. In BC treatment, among 4 to 6% of Cu was associated with soil humic substances. Without amendments and with fertilizer application, Zn solubility increased by 15.4 and 8.4%, respectively, with experiment time. Although Cr was significantly adsorbed to the inorganic fraction, with compost application there was a transfer to organic fraction. A single amendment application is not suitable for immobilizing all metals of concern, because there are diverse union’s behaviors between HM and soil matrix. As the organic matter and phosphate fertilizer were effective in reducing mobility of Cu, the organic matter was more effective in the immobilization of Cr, and inorganic amendment induced the Zn precipitation, results from this pilot study suggest a combined use of these two amendments for soil remediation strategies. However, liming may be further needed to prevent soil acidification on longer time scales. Also, we propose the use of chemical and biological remediation strategies for potential improvement of effectiveness.
Length and Roughness Perception in a Moving-Plateau Touch Display
Authors: Watanabe Junji , Godai Yusuke , Ando Hideyuki
Published: April 2012

We have proposed a tactile geometry display technique based on active finger movement. The technique uses a perceptual feature that, during finger movement, the length of a touched object is perceived to increase when the object is moved in the same direction as the finger movement or to decrease when it is moved in the opposite direction. With this display technique, a wide range of tactile shapes can be presented with realistic rigid edges and continuous surfaces. In this work, to further develop our technique, we performed psychophysical experiments to study perceptions of length and roughness under this presentation technique. The results indicated that the elongation (shrinkage) of the object can be observed regardless of the roughness of the touched object and that the perceived roughness of the object slightly changes but the changes are much smaller than those theoretically expected.
Innovative Simulation Strategies in Education
Authors: Aebersold Michelle , Tschannen Dana , Bathish Melissa
Published: April 2012

The use of simulation in the undergraduate nursing curriculum is gaining popularity and is becoming a foundation of many nursing programs. The purpose of this paper is to highlight a new simulation teaching strategy, virtual reality (VR) simulation, which capitalizes on the technological skills of the new generation student. This small-scale pilot study focused on improving interpersonal skills in senior level nursing students using VR simulation. In this study, a repeated-measure design was used to evaluate the effectiveness of VR simulation on improving student’s performance over a series of two VR scenarios. Using the Emergency Medicine Crisis Resource Management (EMCRM) tool, student performance was evaluated. Overall, the total EMCRM score improved but not significantly. The subscale areas of communication (P=.047, 95% CI:−1.06,−.007) and professional behavior (P=.003, 95% CI:−1.12,−.303) did show a significant improvement between the two scenario exposures. Findings from this study show the potential for virtual reality simulations to have an impact on nursing student performance.
Solid State Adaptive Rotor Using Postbuckled Precompressed, Bending-Twist Coupled Piezoelectric Actuator Elements
Authors: Barrett Ronald M. , Barnhart Ryan
Published: April 2012

This paper is centered on a new actuation mechanism which is integrated on a solid state rotor. This paper outlines the application of such a system via a Post-Buckled Precompression (PBP) technique at the end of a twist-active piezoelectric rotor blade actuator. The basic performance of the system is handily modeled by using laminated plate theory techniques. A dual cantilevered spring system was used to increasingly null the passive stiffness of the root actuator along the feathering axis of the rotor blade. As the precompression levels were increased, it was shown that corresponding blade pitch levels also increased. The PBP cantilever spring system was designed so as to provide a high level of stabilizing pitch-flap coupling and inherent resistance to rotor propeller moments. Experimental testing showed pitch deflections increasing from just 8° peak-to-peak deflections at 650 V/mm field strength to more than 26° at the same field strength with design precompression levels. Dynamic testing showed the corner frequency of the linear system coming down from 63 Hz (3.8/rev) to 53 Hz (3.2/rev). Thrust coefficients manipulation levels were shown to increase from 0.01 to 0.028 with increasing precompression levels. The paper concludes with an overall assessment of the actuator design.
New Results on Stability and Stabilization of Markovian Jump Systems with Partly Known Transition Probabilities
Authors: Guo Yafeng , Zhu Fanglai
Published: April 2012

This paper investigates the problem of stability and stabilization of Markovian jump linear systems with partial information on transition probability. A new stability criterion is obtained for these systems. Comparing with the existing results, the advantage of this paper is that the proposed criterion has fewer variables, however, does not increase any conservatism, which has been proved theoretically. Furthermore, a sufficient condition for the state feedback controller design is derived in terms of linear matrix inequalities. Finally, numerical examples are given to illustrate the effectiveness of the proposed method.
Bioinspired Low-Frequency Material Characterisation
Authors: Hopper C. , Assous S. , Wilkinson P. B. , Gunn D. A. , Jackson P. D. , Rees J. G. , O'Leary R. L. , Lovell M. A.
Published: April 2012

New-coded signals, transmitted by high-sensitivity broadband transducers in the 40–200 kHz range, allow subwavelength material discrimination and thickness determination of polypropylene, polyvinylchloride, and brass samples. Frequency domain spectra enable simultaneous measurement of material properties including longitudinal sound velocity and the attenuation constant as well as thickness measurements. Laboratory test measurements agree well with model results, with sound velocity prediction errors of less than 1%, and thickness discrimination of at least wavelength/15. The resolution of these measurements has only been matched in the past through methods that utilise higher frequencies. The ability to obtain the same resolution using low frequencies has many advantages, particularly when dealing with highly attenuating materials. This approach differs significantly from past biomimetic approaches where actual or simulated animal signals have been used and consequently has the potential for application in a range of fields where both improved penetration and high resolution are required, such as nondestructive testing and evaluation, geophysics, and medical physics.
Recombinant T-Cell Receptor Ligand (RTL) for Treatment of Multiple Sclerosis: A Double-Blind, Placebo-Controlled, Phase 1, Dose-Escalation Study
Authors: Yadav Vijayshree , Bourdette Dennis N. , Bowen James D. , Lynch Sharon G. , Mattson David , Preiningerova Jana , Bever Christopher T. , Simon Jack , Goldstein Andrew , Burrows Gregory G. , Offner Halina , Ferro Al J. , Vandenbark Arthur A.
Published: April 2012

Background. Recombinant T-cell receptor ligand 1000 (RTL1000) is a single-chain protein construct containing the outer two domains of HLA-DR2 linked to myelin-oligodendrocyte-glycoprotein- (MOG-) 35–55 peptide. Analogues of RTL1000 induce T-cell tolerance, reverse clinical and histological disease, and promote repair in experimental autoimmune encephalomyelitis (EAE) in DR2 transgenic, C57BL/6, and SJL/J mice.Objective. Determining the maximum tolerated dose, safety, and tolerability of RTL1000 in multiple sclerosis (MS) subjects.Methods. This was a multicenter, Phase I dose-escalation study in HLA-DR2+MS subjects. Consecutive cohorts received RTL1000 doses of 2, 6, 20, 60, 200, and 100 mg, respectively. Subjects within each cohort randomly received a single intravenous infusion of RTL1000 or placebo at a 4 : 2 ratio. Safety monitoring included clinical, laboratory, and brain magnetic resonance imaging (MRI) evaluations.Results. Thirty-four subjects completed the protocol. All subjects tolerated the 2–60 mg doses of RTL1000. Doses ≥100 mg caused hypotension and diarrhea in 3 of 4 subjects, leading to discontinuation of further enrollment.Conclusions. The maximum tolerated dose of RTL1000 in MS subjects is 60 mg, comparable to effective RTL doses in EAE. RTL1000 is a novel approach for MS treatment that may induce immunoregulation without immunosuppression and promote neural repair.
A Dried Yeast Fermentate Prevents and Reduces Inflammation in Two Separate Experimental Immune Models
Authors: Evans Malkanthi , Reeves Stuart , Robinson Larry E.
Published: April 2012

Diverse and significant benefits against cold/flu symptoms and seasonal allergies have been observed with a dried fermentate (DF) derived fromSaccharomyces cerevisiae(EpiCor) in multiple published randomized trials. To determine if DF may influence other immune conditions, two separate animal studies were conducted. Study 1 examined the ability of DF to prevent or reduce inflammation when given orally for 14 days to rats prior to receiving 1% carrageenan (localized inflammation model). DF significantly (P<0.05) reduced swelling at all time points (1, 2, 3, 6, 12, and 24 hours) versus the control. Edema severity and PGE2 levels were reduced by approximately 50% and 25% (P<0.05), respectively. Study 2 examined the ability of DF to treat established inflammation induced by type-2 collagen in mice over 4 weeks (autoimmune arthritis model). Significantly reduced arthritis scores, antibody response to type-2 collagen, and interferon-gamma levels were observed compared to controls (all parametersP<0.05). DF favorably impacts multiple acute and potentially chronic immunologic inflammatory control mechanisms and should be further tested in clinical trials.
Survival Data Analysis with Time-Dependent Covariates Using Generalized Additive Models
Authors: Tsujitani Masaaki , Tanaka Yusuke , Sakon Masato
Published: April 2012

We discuss a flexible method for modeling survival data using penalized smoothing splines when the values of covariates change for the duration of the study. The Cox proportional hazards model has been widely used for the analysis of treatment and prognostic effects with censored survival data. However, a number of theoretical problems with respect to the baseline survival function remain unsolved. We use the generalized additive models (GAMs) with B splines to estimate the survival function and select the optimum smoothing parameters based on a variant multifold cross-validation (CV) method. The methods are compared with the generalized cross-validation (GCV) method using data from a long-term study of patients with primary biliary cirrhosis (PBC).
A Great Salt Lake Waterspout
Authors: Simpson Joanne , Roff G. , Morton B. R. , Labas K. , Dietachmayer G. , McCumber M. , Penc R.
Published: April 2012

A waterspout funnel and spray ring were observed under a cumulus line over the Great Salt Lake for about 5 min shortly after sunrise on 26 June 1985. Videotaped features strongly suggested that the funnel rotation was anticyclonic, These observations have been used as the basis for a study of the initiation and evolution of waterspouts through a series of numerical experiments at two scales, that of a cloud and a waterspout.

The cloud scale has been simulated using an improved Goddard-Schlesinger model with nearby Salt Lake City soundings. The main model improvements have been 1) a parameterized, three-class ice phase and 2) a line initialization in addition to the more common axisymmetric buoyant bubble. Cloud-scale vortex pairs developed for each mode of initiation, but a much stronger, more upright, low-level anticyclonic vortex grew from the line initiation than from the bubble. However, cumulus-scale vortices are common while waterspouts are rare, and the real test of a model is whether a waterspout can develop in the limited cumulus lifetime.

The 600-m horizontal grid of the cloud model cannot resolve waterspouts, and a modified Monash high-resolution axisymmetric vortex model with vertical domain and small section has been “embedded” at selected positions and initiated at selected times in the computed flow field of the cloud. Many experiments have been carried out with the vortex model. In the most important series, the boundary conditions were changed with the fields of the model cumulus as it evolved, and the time at which the vortex was started was varied through the lifetime of the parent cloud. Results showed that for each mode of cloud initiation, the vortex that started at the anticyclonic center grew faster than those started at other centers. This result fits with the observed anticyclonic rotation of the waterspout, strongly suggesting that the cloud vorticity was important in its initiation. The greatest azimuthal speed for the bubble-initiated cloud was 11 ms−1 when the vortex model was started at 28 min cloud time with time-varying boundary conditions, whereas it was 21 m s−1 when started at 12 min in the line-initiated cloud. Speeds were comparable when the inner domain moved with the anticyclonic cloud center. These speeds are close to the spray-ring threshold azimuthal velocity of roughly 22 m s−1 estimated by Golden from photographs.

Together, these model results support the hypothesis that, at least in some circumstances, cloud processes alone can produce waterspouts in the absence of external vorticity sources such as surface convergence lines or other shear features.
Gravity Waves Generated by Sheared Three-Dimensional Potential Vorticity Anomalies
Authors: Lott François , Plougonven Riwal , Vanneste Jacques
Published: April 2012

The gravity waves (GWs) produced by three-dimensional potential vorticity (PV) anomalies are examined under the assumption of constant vertical shear, constant stratification, and unbounded domain. As in the two-dimensional case analyzed in an earlier paper, the disturbance near the PV anomaly is well modeled by quasigeostrophic theory. At larger distances the nature of the disturbance changes across the two inertial layers that are located above and below the anomaly, and it takes the form of a vertically propagating GW beyond these.

For a horizontally monochromatic PV anomaly of infinitesimal depth, the disturbance is described analytically using both an exact solution and a WKB approximation; the latter includes an exponentially small term that captures the change of the solution near the PV anomaly induced by the radiation boundary condition in the far field. The analytical results reveal a strong sensitivity of the emission to the Richardson number and to the orientation of the horizontal wavenumber: the absorptive properties of the inertial layers are such that the emission is maximized in the Northern Hemisphere for wavenumbers at negative angles to the shear.

For localized PV anomalies, numerical computations give the temporal evolution of the GW field. Analytical and numerical results are also used to establish an explicit form for the Eliassen–Palm flux that could be used to parameterize GW sources in GCMs. The properties of the Eliassen–Palm flux vector imply that in a westerly shear, the GWs exert a drag in a southwest direction in the upper inertial layer, and in a northwest direction at the altitudes where the GWs dissipate aloft.
Origin of Non-Gaussian Regimes and Predictability in an Atmospheric Model
Authors: Peters John M. , Kravtsov Sergey
Published: April 2012

This study details properties of non-Gaussian regimes and state-dependent ensemble spreads of trajectories in a reduced phase space of an idealized three-level quasigeostrophic (QG3) dynamical model. Methodologically, experiments using two empirical stochastic models of the QG3 time series disentangle the causes of state-dependent persistence properties and nonuniform self-forecast skill of the QG3 model. One reduced model is a standard linear inverse model (LIM) forced by state-independent, additive noise. This model has a linear deterministic operator resulting in a phase-space velocity field with uniform divergence. The other, more general nonlinear stochastic model (NSM) includes a nonlinear propagator and is driven by state-dependent, multiplicative noise. This NSM is found to capture well the full QG3 model trajectory behavior in the reduced phase space, including the non-Gaussian features of the QG3 probability density function and phase-space distribution of the trajectory spreading rates.

Two versions of the NSM—one with a LIM-based drift tensor and QG3-derived multiplicative noise and another with the QG3-derived drift tensor and additive noise—allow the authors to determine relative contributions of the mean drift and multiplicative noise to non-Gaussian regimes and predictability in the QG3 model. In particular, while the regimes arise predominantly because of the nonlinear component of the mean phase-space tendencies, relative predictability of the regimes depends on both the phase-space structure of multiplicative noise and the degree of local convergence of mean phase-space tendencies.
Seasonal Predictability of Wintertime Precipitation in Europe Using the Snow Advance Index
Authors: Brands S. , Manzanas R. , Gutiérrez J. M. , Cohen J.
Published: April 2012

This study tests the applicability of Eurasian snow cover increase in October, as described by the recently published snow advance index (SAI), for forecasting December–February precipitation totals in Europe. On the basis of a classical correlation analysis, global significance was obtained and locally significant correlation coefficients of up to 0.89 and −0.78 were found for the Iberian Peninsula and southern Norway, respectively. For a more robust assessment of these results, a linear regression approach is followed to hindcast the precipitation sums in a 1-yr-out cross-validation framework, using the SAI as the only predictor variable. With this simple empirical approach, local-scale precipitation could be reproduced with a correlation of up to 0.84 and 0.71 for the Iberian Peninsula and southern Norway, respectively, while catchment aggregations on the Iberian Peninsula could be hindcast with a correlation of up to 0.73. These findings are confirmed when repeating the hindcast approach to a degraded but much longer version of the SAI. With the recommendation to monitor the robustness of these results as the sample size of the SAI increases, the authors encourage its use for the purpose of seasonal forecasting in southern Norway and the Iberian Peninsula, where general circulation models are known to perform poorly for the variable in question.
Linguistic interfaces and language acquisition in childhood: Introduction to the special issue
Authors: Rothman Jason , Guijarro-Fuentes Pedro
Published: April 2012

Much contemporary L1 acquisition theory and empirical research are guided by the hypothesis that acquisition delays in children are often related to the integration of information across grammatical and other cognitive modules, such as syntax and discourse-pragmatics (see e.g., Grinstead, 2010). This special issue brings together cutting edge research from all relevant paradigms addressing interface issues in child language acquisition and provides a platform for the study of the interaction between different levels of linguistic knowledge. In this introduction, we present the reader with the tools needed to best understand the contributions of the individual studies and what they bring to bear on larger theoretical questions as a collective.
Should I stay or should I go? How moral arguments influence decisions about offshoring production
Authors: Schröder Martin
Published: April 2012

How do trade unions and works councils influence what managements see as economically rational? Each of the two companies that this article studies planned to offshore its production to a low-cost country. Yet one of the two changed its plans after moral arguments were raised against this, whereas the other offshored in spite of similar arguments. Regardless of a similar economic situation, the two companies did the opposite of each other, yet each defended its action as economically optimal. This comparison of the two case studies therefore shows how moral arguments influence what actors define as economically rational.
Having a First Versus a Second Child
Authors: Barnes Medora W.
Published: April 2012

There are good reasons to suspect that the transition parents go through when having their second child may be different from when having their first, yet these differences remain understudied. This study focuses on one specific area of possible divergence by looking at how first-time versus second-time mothers decide on maternity leave length. To address this question, a series of in-depth semistructured longitudinal interviews were conducted at three different times over the course of 1 year with 16 pregnant public school teachers; 8 of whom were having their first child and 8 their second child. Findings indicate that some areas in which differences emerged include the level of influence of the Family and Medical Leave Act guidelines, comfort level with using paid child care, and the gendered nature of their parenting ideologies.
myTunes: Digital music library users and their self-images
Authors: Krause Amanda E. , Hargreaves David J.
Published: April 2012

This investigation explored the relationships between individuals’ self-images and their interactions with their digital music collections via the commercially predominant program iTunes. Sixty-nine university students completed an internet-based Musical Self-Images Questionnaire (MSIQ) along with a series of questions concerning their iTunes collections. The majority of participants were highly engaged with music, regardless of their varied musical backgrounds. Factor analysis of the MSIQ data revealed two distinct self-image groups, which we label as ‘musical practitioner’ (linking ‘overall musician’, ‘performer’, ‘composer’, ‘teacher’, and ‘listener’) and ‘music consumer’ (linking ‘listener’, ‘fan’, and ‘technology user’). Participants used an average of seven attributes to categorize their music, and most consistently used one in particular to sort their collections. Those who rated themselves as higher level performers and fans used the playlist function (which involves compiling sequences of selected tracks) more often than those with lower self-ratings on those scales.
Paraquat-induced convulsion and death: a report of five cases
Authors: Huang Changbao , Zhang Xigang , Jiang Yun , Li Guang , Wang Haochun , Tang Xueping , Wang Qunli
Published: April 2012

Paraquat (PQ) is a potent toxicant for humans, and poisoning with PQ is associated with high mortality. Patients with severe PQ-induced poisoning may die of multiple organ failure involving the circulatory and respiratory systems. Death resulting from epilepsy-like convulsions, which are infrequently noted reported with PQ poisoning, is observed clinically with this condition. This study presents the clinical data of five patients with severe PQ-induced poisoning who died of epilepsy-like convulsions, and related publications were reviewed in order to investigate the pathogenesis, clinical manifestations, and prognosis of these convulsions. Our results may help prevent this event and improve the success of treatment.
Toxic effects of boron on growth and antioxidant system parameters of maize (Zea mays L.) roots
Authors: Esim Nevzat , Tiryaki Deniz , Karadagoglu Omer , Atici Okkes
Published: April 2012

The aim of this study was to investigate the possible oxidative stress and the antioxidant response, which were caused on maize by boron (B). For this, 11- and 15-day-old maize seedlings were subjected to 2 or 4 mM B in the form of boric acid (H3BO3) for 2 and/or 6 days. At the end of the treatment period, root length, hydrogen peroxide (H2O2) content, malondialdehyde (MDA) content and the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) were measured. The results revealed that root length of plants, activity of antioxidative enzymes such as SOD, POX and CAT and also H2O2 contents and MDA levels were seriously affected by excess B. These results suggested that the oxidative stress occurred due to the toxic effect of B.