bluuebunny/crossref_metadata_2025 huggingface dataset:
Bulk behavior of Schur–Hadamard products of symmetric random matrices
Authors: Bose Arup , Mukherjee Soumendu Sundar
Published: March 2014

We develop a general method for establishing the existence of the Limiting Spectral Distributions (LSD) of Schur–Hadamard products of independent symmetric patterned random matrices. We apply this method to show that the LSD of Schur–Hadamard products of some common patterned matrices exist and identify the limits. In particular, the Schur–Hadamard product of independent Toeplitz and Hankel matrices has the semi-circular LSD. We also prove an invariance theorem that may be used to find the LSD in many examples.
Myosin heavy-chain isoforms in the flight and leg muscles of hummingbirds and zebra finches
Authors: Velten Brandy P. , Welch Kenneth C.
Published: March 2014

Myosin heavy chain (MHC) isoform complement is intimately related to a muscle's contractile properties, yet relatively little is known about avian MHC isoforms or how they may vary with fiber type and/or the contractile properties of a muscle. The rapid shortening of muscles necessary to power flight at the high wingbeat frequencies of ruby-throated hummingbirds and zebra finches (25–60 Hz), along with the varied morphology and use of the hummingbird hindlimb, provides a unique opportunity to understand how contractile and morphological properties of avian muscle may be reflected in MHC expression. Isoforms of the hummingbird and zebra finch flight and hindlimb muscles were electrophoretically separated and compared with those of other avian species representing different contractile properties and fiber types. The flight muscles of the study species operate at drastically different contraction rates and are composed of different histochemically defined fiber types, yet each exhibited the same, single MHC isoform corresponding to the chicken adult fast isoform. Thus, despite quantitative differences in the contractile demands of flight muscles across species, this isoform appears necessary for meeting the performance demands of avian powered flight. Variation in flight muscle contractile performance across species may be due to differences in the structural composition of this conserved isoform and/or variation within other mechanically linked proteins. The leg muscles were more varied in their MHC isoform composition across both muscles and species. The disparity in hindlimb MHC expression between hummingbirds and the other species highlights previously observed differences in fiber type composition and thrust production during take-off.
Simultaneous adaptation of the thumb and index finger of the same hand to opposite prism displacements
Authors: Schot Willemijn D. , Brenner Eli , Smeets Jeroen B. J.
Published: March 2014

It only takes a few goal-directed hand movements to adapt one's movements to a prism-induced displacement of the visual scene. Adaptation to the displacement leads to errors in the opposite direction from the initial displacement when the prisms are removed. Such aftereffects are thought to arise from some form of spatial realignment of the senses or from motor learning. Here, we show that humans can simultaneously adapt the movements of the thumb and index finger of the same hand to opposing visual displacements. Neither the felt position of the hand nor the visually perceived direction can change in two opposite directions at the same time, ruling out an explanation based on realignment of the senses. It is conceivable that one could learn to adjust the movements differently for the two digits despite the fact that both adjustments would involve the same hand, but such motor learning should not transfer to matching the position of the unseen digit. As transfer was observed when visually matching the position of the unseen digit, motor learning cannot explain all of the results. An explanation involving supplementing proprioception with a memory-based visual estimate of the position of each unseen digit could explain all of the results. Irrespective of the mechanism, we can conclude that it is possible to adapt the perceived locations of the unseen digits without influencing proprioception.
Organization of local horizontal functional interactions between neurons in the inferior temporal cortex of macaque monkeys
Authors: Tamura Hiroshi , Mori Yoshiya , Kaneko Hidekazu
Published: March 2014

Detailed knowledge of neuronal circuitry is necessary for understanding the mechanisms underlying information processing in the brain. We investigated the organization of horizontal functional interactions in the inferior temporal cortex of macaque monkeys, which plays important roles in visual object recognition. Neuronal activity was recorded from the inferior temporal cortex using an array of eight tetrodes, with spatial separation between paired neurons up to 1.4 mm. We evaluated functional interactions on a time scale of milliseconds using cross-correlation analysis of neuronal activity of the paired neurons. Visual response properties of neurons were evaluated using responses to a set of 100 visual stimuli. Adjacent neuron pairs tended to show strong functional interactions compared with more distant neuron pairs, and neurons with similar stimulus preferences tended to show stronger functional interactions than neurons with different stimulus preferences. Thus horizontal functional interactions in the inferior temporal cortex appear to be organized according to both cortical distances and similarity in stimulus preference between neurons. Furthermore, the relationship between strength of functional interactions and similarity in stimulus preference observed in distant neuron pairs was more prominent than in adjacent pairs. The results suggest that functional circuitry is specifically organized, depending on the horizontal distances between neurons. Such specificity endows each circuit with unique functions.
Assessing the Spectral Separability of Flue Cured Tobacco Varieties Established on Different Planting Dates and under Varying Fertilizer Management Levels
Authors: Svotwa Ezekia , Masuka Anxious J. , Maasdorp Barbara , Murwira Amon
Published: March 2014

The NDVI was used to discriminate tobacco variety, assess fertilizer levels, and determine the impact of planting date on separating crops. A split plot design with four planting dates, September, October, November, and December, as main plots, variety as subplot, and fertilizer treatments as sub-subplots was used. Radiometric measurements were taken from 5 m × 5 m sampling plots, using a multispectral radiometer. The September, October, and November crops had significant variety x fertilizer treatment differences (F<0.05) from the age of 10 weeks. T 66 and KRK26 varieties had similar (F>0.05) NDVI values and these were greater (F<0.5) than those for K E1. The 100% and the 150% fertilizer treatments were similar (F>0.05) and both were greater (F<0.05) than the 50% fertilizer treatments. All of the fertilizer and variety treatments at the December planting dates had similar reflectance characteristics (P>0.05), which were lower (P<0.05) than the September and October planting dates. The results showed that planting dates, varieties, and fertilizer levels could be distinguished using spectral data. Weeks 10-11 and 15 after the start of the experiment were optimal for separating the planting date effect.
A Hand-Foot-and-Mouth Disease Model with Periodic Transmission Rate in Wenzhou, China
Authors: Zhu Yeting , Xu Boyang , Lian Xinze , Lin Wang , Zhou Zumu , Wang Weiming
Published: March 2014

We establish an SEIQRS epidemic model with periodic transmission rate to investigate the spread of seasonal HFMD in Wenzhou. The value of this study lies in two aspects. Mathematically, we show that the global dynamics of the HFMD model can be governed by its reproduction numberR0; ifR0<1, the disease-free equilibrium of the model is globally asymptotically stable, which means that the disease will vanish after some period of time; while ifR0>1, the model has at least one positive periodic solution and is uniformly persistent, which indicates that HFMD becomes an endemic disease. Epidemiologically, based on the statistical data of HFMD in Wenzhou, we find that the HFMD becomes an endemic disease and will break out in Wenzhou. One of the most interesting findings is that, for controlling the HFMD spread, we must increase the quarantined rate or decrease the treatment cycle.
Synthesis and Characterization of Aluminum Doped Zinc Oxide Nanostructures via Hydrothermal Route
Authors: Alkahlout A. , Al Dahoudi N. , Grobelsek I. , Jilavi M. , de Oliveira P. W.
Published: March 2014

Stable crystalline aluminum doped zinc oxide (AZO) nanopowders were synthesized using hydrothermal treatment processing. Three different aluminum precursors have been used. The Al-precursors were found to affect the morphology of the obtained nanopowders. AZO nanoparticles based on zinc acetate and aluminum nitrate have been prepared with different Al/Zn molar ratios. XRD investigations revealed that all the obtained powders have single phase zincite structure with purity of about 99%. The effect of aluminum doping ratio in AZO nanoparticles (based on Al-nitrate precursor) on structure, phase composition, and particle size has been investigated. The incorporation of Al in ZnO was confirmed by UV-Vis spectroscopy revealing a blue shift due to Burstein-Moss effect.
The Contribution of Applied Social Sciences to Obesity Stigma-Related Public Health Approaches
Authors: Bombak Andrea E.
Published: March 2014

Obesity is viewed as a major public health concern, and obesity stigma is pervasive. Such marginalization renders obese persons a “special population.” Weight bias arises in part due to popular sources’ attribution of obesity causation to individual lifestyle factors. This may not accurately reflect the experiences of obese individuals or their perspectives on health and quality of life. A powerful role may exist for applied social scientists, such as anthropologists or sociologists, in exploring the lived and embodied experiences of this largely discredited population. This novel research may aid in public health intervention planning. Through these studies, applied social scientists could help develop a nonstigmatizing, salutogenic approach to public health that accurately reflects the health priorities of all individuals. Such an approach would call upon applied social science’s strengths in investigating the mundane, problematizing the “taken for granted” and developing emic (insiders’) understandings of marginalized populations.
Gross and Morphometric Anatomy of the Male Reproductive System of Bats (Eidolon helvum)
Authors: Danmaigoro A. , Onu J. E. , Sonfada M. L. , Umaru M. A. , Hena S. A. , Mahmuda A.
Published: March 2014

The present study aimed at examining the gross and morphometry of the reproductive tract of the male bats (Eidolon helvum). Thirty male bats (adultsn=17and juvenilesn=13) were captured using net, weighed, aged using relative ossification of the wing bone, and dissected for gross examination. Morphologically, the mean body weight and forearm length in both adults and juveniles were235.31±6.30 g,12.14±0.19 cm and69.54±7.68 g,7.77±0.29 cm, respectively. The testicles were completely descended in adults with the penis projected cranially. The epididymides were found at the median border of the testis and continues as vas deferens. No significant differences(P>0.05)were observed between right and left testicular weights in both adults and juveniles and also in lengths of different parts of the reproductive segments in both age groups assessed, respectively. This work has documented the gross anatomy of the male reproductive tract in bats. Ultrastructure and histochemistry are recommended for further insight into the reproductive biology.
Local Interactions andp-Best Response Set
Authors: Durieu J. , Solal P.
Published: March 2014

We study a local interaction model where agents play a finiten-person game following a perturbed best-response process with inertia. We consider the concept of minimalp-best response set to analyze distributions of actions on the long run. We distinguish between two assumptions made by agents about the matching rule. We show that only actions contained in the minimalp-best response set can be selected provided thatpis sufficiently small. We demonstrate that these predictions are sensitive to the assumptions about the matching rule.
Potential Propagation by Seed and Cuttings of the Azorean NativeCalluna vulgaris(L.) Hull
Authors: Pereira Maria João , Fagundo Helena , Menezes Tiago , Couto João
Published: March 2014

This work investigates the potential propagation by seed and cuttings of the Azorean nativeCalluna vulgaris(L.) Hull. for landscape conservation. With that purpose we have performed several germination and cuttings trials, using plant material from wild populations of this species. In the germination trials, we tested the effects of photoperiod length (8 and 16 h), temperature (10, 15, 20, and 20–10°C), seed age (6, 108, and 270 days), temperature of seed storage (4°C and room temperature), and seed surface sterilization on the germination characteristics. In the cuttings trials, we tested the effects of stem cutting type, cultural conditions, cuttings’ harvest month, and rooting substrates on the rooting percentages. The best percentages of germination, 93 and 90%, were obtained with fresh seeds and surface sterilized and sown under an 8 h photoperiod and with temperatures of 10°C or 15°C, respectively; germination after seed storage during 270 days is significantly superior (71%) when seeds are stored at 4°C. The best percentages of rooting were achieved for straight (96%) or heel cuttings (90%) harvested in March, planted on soil from natural stands ofC. vulgarisandErica azoricaHochst., outdoors in half shade, and partially covered with transparent polyethylene film.
Impulsive Control of the Rotor-Stator Rub Based on Phase Characteristic
Authors: Xu Jieqiong , Li Qunhong , Wang Shimin
Published: March 2014

An impulsive control method is proposed to eliminate the rotor-stator rubbing based on the phase characteristic. The relation between the vibration energy and the phase difference suggests the starting point for controlling the rotor-stator rubbing by implementing impulse. When the contact between the rotor and the stator occurs, the impulse is implemented inx-direction andy-direction several times to avoid the rotor-stator rubbing. The practical feasibility of this approach is investigated by numerical simulations.
Effects of Melatonin and Epiphyseal Proteins on Fluoride-Induced Adverse Changes in Antioxidant Status of Heart, Liver, and Kidney of Rats
Authors: Bharti Vijay K. , Srivastava R. S. , Kumar H. , Bag S. , Majumdar A. C. , Singh G. , Pandi-Perumal S. R. , Brown Gregory M.
Published: March 2014

Several experimental and clinical reports indicated the oxidative stress-mediated adverse changes in vital organs of human and animal in fluoride (F) toxicity. Therefore, the present study was undertaken to evaluate the therapeutic effect of buffalo(Bubalus bubalis)epiphyseal (pineal) proteins (BEP) and melatonin (MEL) against F-induced oxidative stress in heart, liver, and kidney of experimental adult female rats. To accomplish this experimental objective, twenty-four adult female Wistar rats (123–143 g body weights) were divided into four groups, namely, control, F, F + BEP, and F + MEL and were administered sodium fluoride (NaF, 150 ppm elemental F in drinking water), MEL (10 mg/kg BW, i.p.), and BEP (100 µg/kg BW, i.p.) for 28 days. There were significantlyP<0.05high levels of lipid peroxidation and catalase and low levels of reduced glutathione, superoxide dismutase, glutathione reductase, and glutathione peroxidase in cardiac, hepatic, and renal tissues of F-treated rats. Administration of BEP and MEL in F-treated rats, however, significantlyP<0.05attenuated these adverse changes in all the target components of antioxidant defense system of cardiac, hepatic, and renal tissues. The present data suggest that F can induce oxidative stress in liver, heart, and kidney of female rats which may be a mechanism in F toxicity and these adverse effects can be ameliorated by buffalo(Bubalus bubalis)epiphyseal proteins and melatonin by upregulation of antioxidant defense system of heart, liver, and kidney of rats.
A Generalization of a Greguš Fixed Point Theorem in Metric Spaces
Authors: Kutbi Marwan A. , Amini-Harandi A. , Hussain N.
Published: March 2014

We first introduce a new class of contractive mappings in the setting of metric spaces and then we present certain Greguš type fixed point theorems for such mappings. As an application, we derive certain Greguš type common fixed theorems. Our results extend Greguš fixed point theorem in metric spaces and generalize and unify some related results in the literature. An example is also given to support our main result.
Existence and Uniqueness of Positive Periodic Solutions for a Delayed Predator-Prey Model with Dispersion and Impulses
Authors: Luo Zhenguo , Luo Liping , Yang Liu , Gao Zhenghui , Zeng Yunhui
Published: March 2014

An impulsive Lotka-Volterra type predator-prey model with prey dispersal in two-patch environments and time delays is investigated, where we assume the model of patches with a barrier only as far as the prey population is concerned, whereas the predator population has no barriers between patches. By applying the continuation theorem of coincidence degree theory and by means of a suitable Lyapunov functional, a set of easily verifiable sufficient conditions are obtained to guarantee the existence, uniqueness, and global stability of positive periodic solutions of the system. Some known results subject to the underlying systems without impulses are improved and generalized. As an application, we also give two examples to illustrate the feasibility of our main results.
Tai Chi Exercise Increases SOD Activity and Total Antioxidant Status in Saliva and Is Linked to an Improvement of Periodontal Disease in the Elderly
Authors: Mendoza-Núñez Víctor Manuel , Hernández-Monjaraz Beatriz , Santiago-Osorio Edelmiro , Betancourt-Rule José Miguel , Ruiz-Ramos Mirna
Published: March 2014

The aim of this study was to determine the effect of Tai Chi on biological markers of oxidative stress in saliva and its relationship with periodontal disease (PD) in older adults. We carried out a quasi-experimental study with a sample of 71 sedentary volunteers with PD who were divided into a control group of 34 subjects and an experimental group of 37 subjects who performed Tai Chi 5 days a week for a period of 6 months. PD status was characterized using the Periodontal Disease Index (PDI). Superoxide dismutase (SOD), total antioxidant status (TAS), and TBARS levels of both groups were measured by spectrophotometric methods. In addition, inflammation markers (TNF-α, IL-1β, IL-6, IL-8, and IL-10) were measured by flow cytometry. We found a statistically significant increase in SOD activity (P<0.001) and TAS concentration (P<0.05), whereas levels of IL-1βwere significantly lower (P<0.01). Likewise, a statistically significant decrease in the PDI (P<0.05) was observed in subjects who performed Tai Chi during a period of 6 months. Our findings suggest that the practice of Tai Chi has both antioxidant and anti-inflammatory effects that are linked to the improvement of PD in older adults.
Quasi-Jordan Banach Algebras
Authors: Alhefthi Reem K. , Siddiqui Akhlaq A. , Jamjoom Fatmah B.
Published: March 2014

We initiate a study of quasi-Jordan normed algebras. It is demonstrated that any quasi-Jordan Banach algebra with a norm1unit can be given an equivalent norm making the algebra isometrically isomorphic to a closed right ideal of a unital split quasi-Jordan Banach algebra; the set of invertible elements may not be open; the spectrum of any element is nonempty, but it may be neither bounded nor closed and hence not compact. Some characterizations of the unbounded spectrum of an element in a split quasi-Jordan Banach algebra with certain examples are given in the end.
Experimental and Numerical Investigation of the Ground Shock Coupling Factor for Near-Surface Detonations
Authors: Shelton Timothy W. , Ehrgott John Q. , Moral Ramon J. , Barbato Michele
Published: March 2014

This paper presents the results of recent ground shock experiments conducted by the U.S. Army Engineer Research and Development Center to further investigate the adequacy of the coupling factor approach to shallow-buried or near-surface detonations. Comparisons between these recent experimental results and results of numerical simulations of the ground shock propagation in soil are presented. It was found that the coupling factor curve currently adopted in design of buried structures does not accurately represent the actual ground shock propagation in soil and that different coupling factor curves are needed for different physical quantities of interest in design. The results presented in this paper also suggest that the coupling factor curves are functions of several parameters in addition to the depth of burial and that numerical simulations can capture reasonably well the ground shock propagation of soil stresses and particle velocities.
Estimating Rice Yield under Changing Weather Conditions in Kenya Using CERES Rice Model
Authors: Nyang’au W. O. , Mati B. M. , Kalamwa K. , Wanjogu R. K. , Kiplagat L. K.
Published: March 2014

Effects of change in weather conditions on the yields of Basmati 370 and IR 2793-80-1 cultivated under System of Rice Intensification (SRI) in Mwea and Western Kenya irrigation schemes were assessed through sensitivity analysis using the Ceres rice model v 4.5 of the DSSAT modeling system. Genetic coefficients were determined using 2010 experimental data. The model was validated using rice growth and development data during the 2011 cropping season. Two SRI farmers were selected randomly from each irrigation scheme and their farms were used as research fields. Daily maximum and minimum temperatures and precipitation were collected from the weather station in each of the irrigation schemes while daily solar radiation was generated using weatherman in the DSSAT shell. The study revealed that increase in both maximum and minimum temperatures affects Basmati 370 and IR 2793-80-1 grain yield under SRI. Increase in atmospheric CO2concentration led to an increase in grain yield for both Basmati and IR 2793-80-1 under SRI and increase in solar radiation also had an increasing impact on both Basmati 370 and IR 2793-80-1 grain yield. The results of the study therefore show that weather conditions in Kenya affect rice yield under SRI and should be taken into consideration to improve food security.
Primer Based Approach for PCR Amplification of High GC Content Gene:MycobacteriumGene as a Model
Authors: Kumar Arbind , Kaur Jagdeep
Published: March 2014

The genome ofMycobacteriumis rich in GC content and poses problem in amplification of some genes, especially those rich in the GC content in terminal regions, by standard/routine PCR procedures. Attempts have been made to amplify three GC rich genes ofMycobacteriumsp. (Rv0519candRv0774cfromM. tuberculosisandML0314cfromM. leprae). Out of these three genes,Rv0774cgene was amplified with normal primers under standard PCR conditions, while no amplification was observed in case ofRv0519candML0314cgenes. In the present investigation a modified primer based approach was successfully used for amplification of GC rich sequence ofRv0519cthrough codon optimization without changing the native amino acid sequence. The strategy was successfully confirmed by redesigning the standard primers with similar modifications followed by amplification ofML0314cgene.
Correlations between MRI and Information Processing Speed in MS: A Meta-Analysis
Authors: Rao S. M. , Martin A. L. , Huelin R. , Wissinger E. , Khankhel Z. , Kim E. , Fahrbach K.
Published: March 2014

Objectives. To examine relationships between conventional MRI measures and the paced auditory serial addition test (PASAT) and symbol digit modalities test (SDMT).Methods.A systematic literature review was conducted. Included studies had ≥30 multiple sclerosis (MS) patients, administered the SDMT or PASAT, and measured T2LV or brain atrophy. Meta-analysis of MRI/information processing speed (IPS) correlations, analysis of MRI/IPS significance tests to account for reporting bias, and binomial testing to detect trends when comparing correlation strengths of SDMT versus PASAT and T2LV versus atrophy were conducted.Results. The 39 studies identified frequently reported only significant correlations, suggesting reporting bias. Direct meta-analysis was only feasible for correlations between SDMT and T2LV (r=-0.45,P<0.001) and atrophy in patients with mixed-MS subtypes (r=-0.54,P<0.001). Familywise Holm-Bonferroni testing found that selective reporting was not the source of at least half of significant results reported. Binomial tests (P=0.006) favored SDMT over PASAT in strength of MRI correlations.Conclusions. A moderate-to-strong correlation exists between impaired IPS and MRI in mixed MS populations. Correlations with MRI were stronger for SDMT than for PASAT. Neither heterogeneity among populations nor reporting bias appeared to be responsible for these findings.
Nedd8-Activating Enzyme Inhibitor MLN4924 Provides Synergy with Mitomycin C through Interactions with ATR, BRCA1/BRCA2, and Chromatin Dynamics Pathways
Authors: Garcia Khristofer , Blank Jonathan L. , Bouck David C. , Liu Xiaozhen J. , Sappal Darshan S. , Hather Greg , Cosmopoulos Katherine , Thomas Michael P. , Kuranda Mike , Pickard Michael D. , Liu Ray , Bandi Syamala , Smith Peter G. , Lightcap Eric S.
Published: March 2014

MLN4924 is an investigational small-molecule inhibitor of the Nedd8-activating enzyme currently in phase I clinical trials. MLN4924 induces DNA damage via rereplication in most cell lines. This distinct mechanism of DNA damage may affect its ability to combine with standard-of-care agents and may affect the clinical development of MLN4924. As such, we studied its interaction with other DNA-damaging agents. Mitomycin C, cisplatin, cytarabine, UV radiation, SN-38, and gemcitabine demonstrated synergy in combination with MLN4924 in vitro. The combination of mitomycin C and MLN4924 was shown to be synergistic in a mouse xenograft model. Importantly, depletion of genes within the ataxia telangiectasia and Rad3 related (ATR) and BRCA1/BRCA2 pathways, chromatin modification, and transcription-coupled repair reduced the synergy between mitomycin C and MLN4924. In addition, comet assay demonstrated increased DNA strand breaks with the combination of MLN4924 and mitomycin C. Our data suggest that mitomycin C causes stalled replication forks, which when combined with rereplication induced by MLN4924 results in frequent replication fork collisions, leading to cell death. This study provides a straightforward approach to understand the mechanism of synergy, which may provide useful information for the clinical development of these combinations. Mol Cancer Ther; 13(6); 1625–35. ©2014 AACR.
Characterisation of the conformational changes in platelet factor 4 induced by polyanions: towards in vitro prediction of antigenicity
Authors: Brandt Sven , Krauel Krystin , Gottschalk Kay E. , Renné Thomas , Helm Christiane A. , Greinacher Andreas , Block Stephan
Published: March 2014

Heparin-induced thrombocytopenia (HIT) is the most frequent drug-induced immune reaction affecting blood cells. Its antigen is formed when the chemokine platelet factor 4 (PF4) complexes with polyanions. By assessing polyanions of varying length and degree of sulfation using immunoassay and circular dichroism (CD)-spectroscopy, we show that PF4 structural changes resulting in antiparallel β-sheet content >30% make PF4/polyanion complexes antigenic. Further, we found that polyphosphates (polyP-55) induce antigenic changes on PF4, whereas fondaparinux does not. We provide a model suggesting that conformational changes exposing antigens on PF4/polyanion complexes occur in the hairpin involving AA 32–38, which form together with C-terminal AA (66–70) of the adjacent PF4 monomer a continuous patch on the PF4 tetramer surface, explaining why only tetrameric PF4 molecules express “HIT antigens”. The correlation of antibody binding in immunoassays with PF4 structural changes provides the intriguing possibility that CD-spectroscopy could become the first antibody-independent, in vitro method to predict potential immunogenicity of drugs. CD-spectroscopy could identify compounds during preclinical drug development that induce PF4 structural changes correlated with antigenicity. The clinical relevance can then be specifically addressed during clinical trials. Whether these findings can be transferred to other endogenous proteins requires further studies.
In vivo prostacyclin biosynthesis and effects of different aspirin regimens in patients with essential thrombocythaemia
Authors: Rocca Bianca , Squellerio Isabella , Dragani Alfredo , Veglia Fabrizio , Pagliaccia Francesca , Porro Benedetta , Barbieri Silvia Stella , Tremoli Elena , Patrono Carlo , Cavalca Viviana
Published: March 2014

Essential thrombocythaemia (ET) is characterised by enhanced platelet generation and thrombosis. Once daily (od) aspirin incompletely inhibits platelet thromboxane (TX)A2 production in ET. A twice daily (bid) dosing is necessary to fully inhibit TXA2. Whether this dosing regimen affects in vivo prostacyclin (PGI2) biosynthesis is unknown. PGI2 biosynthesis was characterised in 50 ET patients on enteric-coated (EC) aspirin 100 mg od, by measuring its urinary metabolite, 2,3-dinor-6-keto-PGF1α (PGI-M). Moreover, in a crossover study 22 patients poorly responsive to standard aspirin based on serum TXB2 levels (>4 ng/ml) were randomised to different seven-day aspirin regimens: EC aspirin 100 mg od, 100 mg bid, 200 mg od, or plain as-pirin 100 mg od. PGI-M measured 24 hours after the last aspirin intake (EC, 100 mg od) was similar in patients and healthy subjects both on (n=10) and off (n=30) aspirin. PGI-M was unrelated to in vivo TXA2 biosynthesis, and not affected by EC aspirin 100 mg bid or 200 mg od as compared to EC 100 mg od. PGI2 biosynthesis in aspirin-treated ET patients appears unrelated to TXA2 biosynthesis, and not affected by an improved aspirin regimen, demonstrating its vascular safety for future trials.
Testing Cardiovascular Drug Safety and Efficacy in Randomized Trials
Authors: FitzGerald Garret A.
Published: March 2014

Randomized trials provide the gold standard evidence on which rests the decision to approve novel therapeutics for clinical use. They are large and expensive and provide average but unbiased estimates of efficacy and risk. Concern has been expressed about how unrepresentative populations and conditions that pertain in randomized trials might be of the real world, including concerns about the homogeneity of the biomedical and adherence characteristics of volunteers entered into such trials, the dose and constancy of drug administration and the mixture of additional medications that are restricted in such trials but might influence outcome in practice. A distinction has been drawn between trials that establish efficacy and those that demonstrate effectiveness, drugs that patients actually consume in the real world for clinical benefit. However, randomized controlled trials remain the gold standard for establishing efficacy and the testing of effectiveness with less rigorous approaches is a secondary, albeit important consideration. Despite this, there is an appreciation that average results may conceal considerable interindividual variation in drug response, leading to a failure to appreciate clinical value or risk in subsets of patients. Thus, attempts are now being made to individualize risk estimates by modulating those derived from large randomized trials with the individual baseline risk estimates based on demographic and biological criteria—the individual Numbers Needed to Treat to obtain a benefit, such as a life saved. Here, I will consider some reasons why large phase 3 trials—by far the most expensive element of drug development—may fail to address the unmet medical needs, which should justify such effort and investment.
The Dispersal of Dense Water Formed in an Idealized Coastal Polynya on a Shallow Sloping Shelf
Authors: Zhang Weifeng G. , Cenedese Claudia
Published: March 2014

This study examines the dispersal of dense water formed in an idealized coastal polynya on a sloping shelf in the absence of ambient circulation and stratification. Both numerical and laboratory experiments reveal two separate bottom pathways for the dense water: an offshore plume moving downslope into deeper ambient water and a coastal current flowing in the direction of Kelvin wave propagation. Scaling analysis shows that the velocity of the offshore plume is proportional not only to the reduced gravity, bottom slope, and inverse of the Coriolis parameter, but also to the ratio of the dense water depth to total water depth. The dense water coastal current is generated by the along-shelf baroclinic pressure gradient. Its dynamics can be separated into two stages: (i) near the source region, where viscous terms are negligible, its speed is proportional to the reduced gravity wave speed and (ii) in the far field, where bottom drag becomes important and balances the pressure gradient, the velocity is proportional to Hc[g′/(LCd)]1/2 in which Hc is the water depth at the coast, g′ the reduced gravity, Cd the quadratic bottom drag coefficient, and L the along-shelf span of the baroclinic pressure gradient. The velocity scalings are verified using numerical and laboratory sensitivity experiments. The numerical simulations suggest that only 3%–23% of the dense water enters the coastal pathway, and the percentage depends highly on the ratio of the velocities of the offshore and coastal plumes. This makes the velocity ratio potentially useful for observational studies to assess the amount of dense water formed in coastal polynyas.
Intensified Diurnal Tides along the Oregon Coast
Authors: Osborne J. J. , Kurapov A. L. , Egbert G. D. , Kosro P. M.
Published: March 2014

Intensified diurnal tides are found along portions of the Oregon shelf (U.S. West Coast) based on analyses of high-frequency (HF) radar surface current data and outputs of a 1-km resolution ocean circulation model. The K1 tidal currents with magnitudes near 0.07 m s−1 over a wider part of the shelf (Heceta Bank complex; 44°–44.5°N), previously predicted by Erofeeva et al., are confirmed here by newly available HF radar data. Intensified diurnal tides are also found along the narrow shelf south of Heceta Bank. In the close vicinity of Cape Blanco (42.8°N), diurnal tidal currents (K1 and O1 constituents combined) may reach 0.3 m s−1. Appreciable differences in diurnal tide intensity are found depending on whether the model is forced with tides and winds (TW) or only tides. Also, diurnal variability in wind forcing is found to affect diurnal surface velocities. For the case forced by tides alone, results strongly depend on whether the model ocean is stratified [tides only, stratified (TOS)] or not [tides only, no stratification (TONS)]. In case TONS, coastal-trapped waves at diurnal frequencies do not occur over the narrow shelf south of 43.5°N, consistent with the dispersion analysis of a linear shallow-water model. However, in case TOS, diurnal tides are intensified in that area, associated with the presence of coastal-trapped waves. Case TW produces the strongest modeled diurnal tidal motions over the entire Oregon shelf, partially due to cross-shore tidal displacement (advection) of alongshore subinertial currents. At Cape Blanco, diurnal tidal variability dominates the modeled relative vorticity spectrum, suggesting that tides may influence the separation of the alongshore coastal jet at that location.
Nasopharyngeal Acid Reflux and Eustachian Tube Dysfunction in Adults
Authors: Brunworth Joseph D. , Mahboubi Hossein , Garg Rohit , Johnson Brandon , Brandon Bryan , Djalilian Hamid R.
Published: March 2014

Objective:

This study aimed to evaluate the relationship between nasopharyngeal pH and Eustachian tube dysfunction (ETD) in adults.

Study Design:

Unmatched case-control study.

Methods:

Forty-one subjects, 20 adults with a diagnosis of ETD and 21 healthy adults as controls, were enrolled from an outpatient clinic. All subjects had a Dx–pH probe placed near the torus tubarius in the posterior nasopharynx for 24 hours. The pH values were recorded every 0.5 second. Decreases in pH were considered as reflux events if the pH dropped below 5.5.

Results:

The average nasopharyngeal pH value was 6.90 (range, 5.33-7.73) in the subjects with ETD and 7.07 (range, 5.99-7.94) in the controls. The difference between the 2 groups was not statistically significant ( P = .30). The ETD group, on average, had a higher number of nasopharyngeal reflux events (2.3 ± 1.6 vs 0.8 ± 1.2, respectively; P = .002) and higher reflux finding score (3.6 ± 2.7 vs 0.4 ± 1.4, respectively; P < .001) than the control group.

Conclusion:

By using a novel pH probe that allows detection of acidity in a nonliquid environment, a comparison of nasopharyngeal pH between control patients and those with ETD was performed. Eustachian tube dysfunction was more likely to be associated with a higher number of nasopharyngeal reflux events and higher reflux finding score. Nasopharyngeal reflux may have a role in the pathogenesis of ETD.
Minimally Invasive Video-Assisted Thyroidectomy
Authors: Kania Romain , Hammami Hassene , Vérillaud Benjamin , Blancal Jean-Philippe , Sauvaget Elisabeth , Tran Hugo , Leclerc Nicolas , Al Tabaa Khaled , Herman Philippe , Pons Yoann
Published: March 2014

Background:

The objectives of this study were first to show principles of the minimally invasive video-assisted thyroidectomy (MIVAT), based on a video highlighting critical steps, and second to discuss tips and pearls to assist surgical teams that would like to start using this technique.

Methods:

Based on a video, we described tips and pearls of a MIVAT.

Results:

MIVAT includes 5 main steps: (1) skin incision and identification of the common carotid artery, (2) dissection and ligation of the upper pedicle, (3) identification of the inferior laryngeal nerve and parathyroid glands, (4) isthmectomy and lobe extraction, and (5) closure.

Discussion:

Coordination between the surgeon and the 2 assistants is of paramount importance for the performance of MIVAT. Appropriate material is also required. The magnification and tissue contrast emphasizes the identification of the vessels, the superior and inferior laryngeal nerves, and parathyroid glands, on a large-view screen.
Screening Obese Children and Adolescents for Prediabetes and/or Type 2 Diabetes in Pediatric Practices
Authors: Brar Preneet C. , Mengwall Lisa , Franklin Bonita H. , Fierman Arthur H.
Published: March 2014

Background. Increased prevalence of type 2 diabetes mellitus (T2DM) makes it important for pediatricians to use effective screening tools for risk assessment of prediabetes/T2DM in children. Methods. Children (n = 149) who had an oral glucose tolerance test (OGTT) and glycated hemoglobin (HbA1c) were studied. American Diabetes Association recommended screening criteria—HbA1c ≥5.7% and fasting plasma glucose (FPG) ≥100 mg/dL—were compared against OGTT. The homeostatic model assessment of insulin resistance (HOMA-IR), a mathematical index derived from fasting insulin and glucose, was compared with OGTT. We studied whether combining screening tests (HbA1c and fasting glucose or HbA1c and HOMA-IR) improved accuracy of prediction of the OGTT. Results. HbA1c of ≥5.7% had a sensitivity of 75% and specificity of 57% when compared with the OGTT. Combining screening tests (HbA1c ≥5.7% and FPG ≥100 mg/dL; HbA1c ≥5.7% and HOMA-IR ≥3.4) resulted in improved sensitivity (95.5% for each), with the HbA1c-FPG doing better than the HbA1c-HOMA-IR combination in terms of ability to rule out prediabetes (likelihood ratio [LR]) negative. 0.07 vs 0.14). Conclusions. HbA1c of ≥5.7% provided fair discrimination of glucose tolerance compared with the OGTT. The combination of HbA1c and FPG is a useful method for identifying children who require an OGTT.
Further Evidence of the Comparative Memorability of Alliterative Expressions in Second Language Learning
Authors: Boers Frank , Lindstromberg Seth , Webb Stuart
Published: March 2014

Previous research has furnished evidence that alliterative expressions (e.g. a slippery slope) are comparatively memorable for second language learners, at least when these expressions are attended to as decontextualized items (Lindstromberg and Boers, 2008a; Boers et al., 2012). The present study investigates whether alliteration renders lexical phrases comparatively memorable also when these phrases are encountered in texts read primarily with a focus on content. Fifty-four EFL students read a text adapted so as to include five instances of 12 idiomatic expressions. The results of surprise post-tests suggest that the alliterative phrases among these target expressions left significantly stronger memory traces than the non-alliterative ones, especially regarding the form or composition of the phrases.
The Role of Social Media in International Tourist’s Decision Making
Authors: Schroeder Ashley , Pennington-Gray Lori
Published: March 2014

Recent crises have highlighted the increasingly important role of social media in crisis communications. Attention has been given to residents’ use of social media during a crisis; however, there is a lack of research which focuses on factors that influence tourists’ use of social media during a crisis. Understanding these factors can have practical implications for destinations in crisis. Thus, the purpose of this study was to investigate whether internal, travel-related, and demographic factors affect the likelihood to use social media to seek information if a crisis were to occur while traveling. Linear regression revealed that the countries of origin of India, Brazil, Australia, and South Korea; the age group 31–40; past international travel experience; and perceptions of crime, natural disasters, disease, financial, equipment failure, weather, cultural barriers, and political risk were positively associated with the likelihood of using social media in the event of a crisis during travel.
Comparative Uterotrophic Effects of Endoxifen and Tamoxifen in Ovariectomized Sprague-Dawley Rats
Authors: Schweikart Karen M. , Eldridge Sandy R. , Safgren Stephanie L. , Parman Toufan , Reid Joel M. , Ames Matthew M. , Goetz Matthew P. , Davis Myrtle A.
Published: March 2014

Endoxifen (4-hydroxy-N-desmethyl-tamoxifen), one of the major active metabolites of tamoxifen, has substantially greater estrogen antagonist properties and antiproliferative effects in breast tumor cells than tamoxifen, a mixed estrogen agonist/antagonist. An associated risk of endometrial cancer and hyperplasia has been linked to the estrogen agonist properties of tamoxifen. We evaluated endoxifen using a classic uterotrophic effects method. Rats were given endoxifen or tamoxifen orally for 3 days. Estradiol was the positive control. Endoxifen and tamoxifen plasma levels exceeded those previously observed clinically. Uterine weight was 3-fold higher in the estradiol group than in the tamoxifen or endoxifen groups, which did not differ from vehicle controls. Tamoxifen and endoxifen caused a greater increase in luminal epithelial cell height than estradiol. Both tamoxifen and endoxifen produced an increase in the stromal BrdU labeling index (LI) that was ≤ estradiol and inversely related to dose, but did not affect luminal epithelial cell BrdU LI. As expected, estradiol increased luminal epithelial cell proliferation. These results indicate that endoxifen induces uterotrophic effects, but is less potent than estradiol in eliciting these effects. Given prior preclinical observations that endoxifen has superior antitumor activity than tamoxifen, the observations of similar uterine effects suggest that the endoxifen risk/benefit ratio may be superior to tamoxifen.
Personally Modifiable Risk Factors Associated with Pediatric Hearing Loss: A Systematic Review
Authors: Vasconcellos Adam P. , Kyle Meghann E. , Gilani Sapideh , Shin Jennifer J.
Published: March 2014

Background

Pediatric hearing loss is an increasingly recognized problem with significant implications. Increasing our quantitative understanding of potentially modifiable environmental risk factors for hearing loss may form the foundation for prevention and screening programs.

Objective

To determine whether specific threshold exposure levels of personally modifiable risk factors for hearing loss have been defined, with the overarching goal of providing actionable guidance for the prevention of pediatric hearing loss.

Data Sources

A systematic review was performed. Computerized searches of PubMed, EMBASE, and the Cochrane Library were completed and supplemented with manual searches.

Review Methods

Inclusion/exclusion criteria were designed to determine specific threshold values of personally modifiable risk factors on hearing loss in the pediatric population. Searches and data extraction were performed by independent reviewers.

Results

There were 38 criterion‐meeting studies, including a total of 50,651 subjects. Threshold noise exposures significantly associated with hearing loss in youth included: (1) more than 4 hours per week or more than 5 years of personal headphone usage, (2) more than 4 visits per month to a discotheque, and (3) working on a mechanized farm. Quantified tobacco levels of concern included any level of in utero smoke exposure as well as secondhand exposure sufficient to elevate serum cotinine.

Conclusions

Specific thresholds analyses are limited. Future studies would ideally focus on stratifying risk according to clearly defined levels of exposure, in order to provide actionable guidance for children and families.
Effects of Type 2 Diabetes on Otoacoustic Emissions and the Medial Olivocochlear Reflex
Authors: Eren Erdem , Harman Ece , Arslanoğlu Seçil , Önal Kazım
Published: March 2014

Objective

To demonstrate if cochleopathy in patients with type 2 diabetes with normal audiometric hearing threshold can be detected with otoacoustic emissions or medial olivocochlear (MOC) reflex measurements.

Study Design

Cross‐sectional study.

Setting

Tertiary university teaching hospital.

Methods

The study involved 40 type 2 diabetic patients and 24 healthy volunteers. All participants who showed normal otoscopic findings, hearing thresholds, and acoustic admittance were included. Cochlear activity of participants was evaluated by means of distortion product otoacoustic emissions (DPOAEs) and transient otoacoustic emissions (TOAEs). The MOC reflex was evoked with contralateral acoustic stimulation and recorded with DPOAEs and TOAEs.

Result

A comparison of DPOAE and TOAE levels with a t test between patient and control groups revealed no significant difference (P >. 05). A comparison of the MOC reflex response between the 2 groups also revealed no statistically significant difference (P >. 05).

Conclusion

Although decreased OAE amplitude levels were found in diabetic patients, there was no statistically significant difference in OAEs and MOC reflex. Additional studies are needed to evaluate the role of OAEs and MOC reflex in normal‐hearing patients with diabetes.