bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribution of nerve growth factor to upregulation of P2X3 expression in DRG neurons of rats with femoral artery occlusion
Authors: Liu Jiahao , Li Jialiu David , Lu Jian , Xing Jihong , Li Jianhua
Published: June 2011

Femoral artery occlusion augments the sympathetic nerve and pressor responses to muscle contraction and muscle metabolites injected into the arterial blood supply of the hindlimb muscles in rats. The underlying mechanism by which these reflex responses are enhanced after muscle vascular insufficiency is unclear. Purinergic P2X3 receptor has been reported to contribute to the metabolic component of the exercise pressor reflex. Thus the purpose of this study was to examine if chronic femoral occlusion would alter the expression of P2X3 in dorsal root ganglion (DRG) neurons of rats. Also, P2X3-mediated sympathetic responsiveness was examined after femoral occlusion. In addition, the role played by nerve growth factor (NGF) in regulating the expression and response of P2X3 was examined. Western blot analysis showed that 24 h of femoral ligation increased the levels of P2X3 (optical density: 0.93 ± 0.07 in control and 1.37 ± 0.10 after occlusion; P < 0.05 vs. control). The fluorescence immunohistochemistry further demonstrated that the occlusion elevated P2X3 expression in DRG neurons (percentage of P2X3-positive cells: 33 ± 3% in control and 51 ± 3% in occlusion; P < 0.05 vs. control). Furthermore, the results showed that responses of renal sympathetic nerve activity and blood pressure to stimulation of P2X were greater in occluded rats than responses in control rats by injection of α,β-methylene ATP into the arterial blood supply of the hindlimb muscle. Finally, infusion of NGF in the hindlimb muscles of healthy rats increased P2X3 (optical density: 0.98 ± 0.12 in control and 1.37 ± 0.16 with NGF; P < 0.05 vs. control). The pressor response to injection of α,β-methylene ATP was increased in the rats with NGF infusion. Likewise, blocking NGF attenuated exaggeration of the reflex response induced by α,β-methylene ATP in occluded rats. The findings of this study suggest that the levels of P2X3 in primary afferent neurons are upregulated as the blood supply to the hindlimb is deficient under ischemic conditions, leading to augmentation of the muscle reflex. NGF is closely related to increases in P2X3 receptor expression and response.
Angiotensin II-induced process of angiogenesis is mediated by spleen tyrosine kinase via VEGF receptor-1 phosphorylation
Authors: Buharalioglu Cuneyt K. , Song Chi Young , Yaghini Fariborz A. , Ghafoor Hafiz U. B. , Motiwala Mustafa , Adris Tusita , Estes Anne M. , Malik Kafait U.
Published: June 2011

Spleen tyrosine kinase (Syk), expressed in endothelial cells, has been implicated in migration and proliferation and in vasculogenesis. This study was conducted to determine the contribution of Syk and the underlying mechanism to the angiogenic effect of ANG II and VEGF. Angiogenesis was determined by tube formation from the endothelial cell line EA.hy926 (EA) and human umbilical vein endothelial cells (HUVECs) and microvessel sprouting in rat aortic rings. ANG II (10 nM), EGF (30 ng/ml), and VEGF (50 ng/ml) stimulated EA cells and HUVECs to form tubular networks and increased aortic sprouting; these effects were blocked by VEGF receptor-1 and Flt-1 antibody (Flt-1/Fc) but not by the VEGF receptor-2 (Flk-1) antagonist SU-1498. ANG II increased the phosphorylation of Flt-1 but not Flk-1, whereas VEGF increased the phosphorylation of both receptors in EA cells and HUVECs. VEGF expression elicited by ANG II was not altered by Flt-1/Fc or SU-1498. EGF stimulated tube formation from EA cells and HUVECs and Flt-1 phosphorylation and aortic sprouting, which were blocked by the EGF receptor antagonist AG-1478 and Flt-1/Fc but not by SU-1498. ANG II-, EGF-, and VEGF-induced tube formation and aortic sprouting were attenuated by the Syk inhibitor piceatannol and by Syk short hairpin interfering (sh)RNA and small interfering RNA, respectively. ANG II, EGF, and VEGF increased Syk phosphorylation, which was inhibited by piceatannol and Syk shRNA in EA cells and HUVECs. Neither piceatannol nor Syk shRNA altered ANG II-, EGF-, or VEGF-induced phosphorylation of Flt-1. These data suggest that ANG II stimulates angiogenesis via transactivation of the EGF receptor, which promotes the phosphorylation of Flt-1 and activation of Syk independent of VEGF expression.
Mechanical stimuli and IL-13 interact at integrin adhesion complexes to regulate expression of smooth muscle myosin heavy chain in airway smooth muscle tissue
Authors: Desai Leena P. , Wu Yidi , Tepper Robert S. , Gunst Susan J.
Published: June 2011

Airway smooth muscle phenotype may be modulated in response to external stimuli under physiological and pathophysiological conditions. The effect of mechanical forces on airway smooth muscle phenotype were evaluated in vitro by suspending weights of 0.5 or 1 g from the ends of canine tracheal smooth muscle tissues, incubating the weighted tissues for 6 h, and then measuring the expression of the phenotypic marker protein, smooth muscle myosin heavy chain (SmMHC). Incubation of the tissues at a high load significantly increased expression of SmMHC compared with incubation at low load. Incubation of the tissues at a high load also decreased activation of PKB/Akt, as indicated by its phosphorylation at Ser 473. Inhibition of Akt or phosphatidylinositol-3,4,5 triphosphate-kinase increased SmMHC expression in tissues at low load but did not affect SmMHC expression at high load. IL-13 induced a significant increase in Akt activation and suppressed the expression of SmMHC protein at both low and high loads. The role of integrin signaling in mechanotransduction was evaluated by expressing a PINCH (LIM1–2) fragment in the muscle tissues that prevents the membrane localization of the integrin-binding IPP complex (ILK/PINCH/α-parvin), and also by expressing an inactive integrin-linked kinase mutant (ILK S343A) that inhibits endogenous ILK activity. Both mutants inhibited Akt activation and increased expression of SmMHC protein at low load but had no effect at high load. These results suggest that mechanical stress and IL-13 both act through an integrin-mediated signaling pathway to oppositely regulate the expression of phenotypic marker proteins in intact airway smooth muscle tissues. The stimulatory effects of mechanical stress on contractile protein expression oppose the suppression of contractile protein expression mediated by IL-13; thus the imposition of mechanical strain may inhibit changes in airway smooth muscle phenotype induced by inflammatory mediators.
Acute mountain sickness, inflammation, and permeability: new insights from a blood biomarker study
Authors: Julian Colleen Glyde , Subudhi Andrew W. , Wilson Megan J. , Dimmen Andrew C. , Pecha Travis , Roach Robert C.
Published: June 2011

The pathophysiology of acute mountain sickness (AMS) is unknown. One hypothesis is that hypoxia induces biochemical changes that disrupt the blood-brain barrier (BBB) and, subsequently, lead to the development of cerebral edema and the defining symptoms of AMS. This study explores the relationship between AMS and biomarkers thought to protect against or contribute to BBB disruption. Twenty healthy volunteers participated in a series of hypobaric hypoxia trials distinguished by pretreatment with placebo, acetazolamide (250 mg), or dexamethasone (4 mg), administered using a randomized, double-blind, placebo-controlled, crossover design. Each trial included peripheral blood sampling and AMS assessment before (−15 and 0 h) and during (0.5, 4, and 9 h) a 10-h hypoxic exposure (barometric pressure = 425 mmHg). Anti-inflammatory and/or anti-permeability [interleukin (IL)-1 receptor agonist (IL-1RA), heat shock protein (HSP)-70, and adrenomedullin], proinflammatory (IL-6, IL-8, IL-2, IL-1β, and substance P), angiogenic, or chemotactic biomarkers (macrophage inflammatory protein-1β, VEGF, TNF-α, monocyte chemotactic protein-1, and matrix metalloproteinase-9) were assessed. AMS-resistant subjects had higher IL-1RA (4 and 9 h and overall), HSP-70 (0 h and overall), and adrenomedullin (overall) compared with AMS-susceptible subjects. Acetazolamide raised IL-1RA and HSP-70 compared with placebo in AMS-susceptible subjects. Dexamethasone also increased HSP-70 and adrenomedullin in AMS-susceptible subjects. Macrophage inflammatory protein-1β was higher in AMS-susceptible than AMS-resistant subjects after 4 h of hypoxia; dexamethasone minimized this difference. Other biomarkers were unrelated to AMS. Resistance to AMS was accompanied by a marked anti-inflammatory and/or anti-permeability response that may have prevented downstream pathophysiological events leading to AMS. Conversely, AMS susceptibility does not appear to be related to an exaggerated inflammatory response.
Angiostrongylus vasorum: Experimental Infection and Larval Development inOmalonyx matheroni
Authors: Mozzer L. R. , Montresor L. C. , Vidigal T. H. D. A. , Lima W. S.
Published: May 2011

The susceptibility and suitability ofOmalonyx matheronias an intermediate host ofAngiostrongylus vasorumand the characteristics of larval recovery and development were investigated. Mollusks were infected, and from the 3rd to the 25th day after infection, larvae were recovered from groups of 50 individuals. The first observation of L2 was on the 5th day, and the first observation of L3 was on the 10th day. From the 22nd day on, all larvae were at the L3 stadium. Larval recovery varied from 78.2% to 95.2%. We found larval development to be faster inO. matheronithan inBiomphalaria glabrata. Our findings indicate that this mollusk is highly susceptible toA. vasorum. Infective L3 were orally inoculated into a dog, and the prepatent period was 39 days. This is the first study to focus onO. matheronias an intermediate host ofA. vasorum.
Primary Lymphangioma of the Tonsil: A Case Report
Authors: Balatsouras Dimitrios G. , Fassolis Alexandros , Koukoutsis George , Ganelis Panayotis , Kaberos Antonis
Published: May 2011

Benign tumors of the tonsils occur infrequently. Lymphangiomas are rare congenital tumors of the lymphatic system, and tonsillar lymphangioma is an extremely rare occurrence. Its pathogenesis is uncertain, but history, clinical examination, and histological examination should establish the diagnosis. We present a 17-year-old white male with lymphangioma of the right tonsil. The tonsils were excised and biopsy confirmed the diagnosis. Tonsillar lymphangioma is a rare clinical entity, which should be known to the otolaryngologist, in order to diagnose and treat it appropriately and avoid confusion with tonsillar malignancies.
Summability of Sequences and Selection Properties
Authors: Djurčić Dragan , Kočinac Ljubiša D. R. , Žižović Mališa R.
Published: May 2011

We prove that some classes of summable sequences of positive real numbers satisfy several selection principles related to a special kind of convergence.
Total Splenectomy due to an Unexpected “Complication” after Successful Extended Laparoscopic Partial Decapsulation of a Giant Epidermoid Splenic Cyst: A Case Report
Authors: Pitiakoudis Michail , Zezos Petros , Oikonomou Anastasia , Laftsidis Prodromos , Kouklakis Georgios , Simopoulos Constantinos
Published: May 2011

Splenic cysts are rare entities and are classified as true cysts or pseudocysts based on the presence of an epithelial lining. Congenital nonparasitic true cysts can be epidermoid, dermoid, or endodermoid, present at a young age, and are commonly located in the upper pole of the spleen. Surgical treatment is recommended for symptomatic, large (more than 5 cm), or complicated cysts. Depending on cyst number, location, relation to hilus, and the major splenic vessels, the surgical options include aspiration, marsupialization, cystectomy, partial cystectomy (decapsulation), and partial or complete splenectomy. Laparoscopic techniques have now become the standard approach for many conditions, including the splenic cysts, with emphasis on the spleen-preserving minimally invasive operations. We present the successful extended partial laparoscopic decapsulation of a giant epidermoid splenic cyst in a young female patient that, although asymptomatic, was unfortunately followed by complete splenectomy five days later due to a misinterpreted abdominal CT suggesting splenic postoperative ischemia.
Characteristics of Embedded-Shock-Free Compressible Vortex Rings: A Detailed Study Using PIV
Authors: Dora C. Lakshmana , Saravanan D. , Karunakar K. , Das Debopam
Published: May 2011

The present study focus on evolution of compressible vortex ring generated at the open end of a shock tube through accurate measurement of velocity field using Particle Image Velocimetry (PIV). To investigate the unsteady characteristics of embedded shock-free, low Mach number vortex rings, two cases (shock Mach numbers, M=1.27 and M=1.37) are considered for PIV measurements. Time-dependent variations of circulation, core and ring diameters, and ring velocity are calculated from the measured velocity field. Pinching-off process is investigated in detail for both cases. Formation time and the time of complete detachment of the vortex ring from the trailing jet are identified from the velocity and vorticity field. The ring formation is complete at about t *(= t U b/ D)=1.75 and 1.65 for M=1.27 and 1.37, respectively, where t is time, U b is fluid velocity behind the shock at exit, and D is tube diameter. Complete detachment of the vortex ring from the trailing jet is observed at [Formula: see text] and 2.9 for M=1.27 and 1.37, respectively.
Testing for Nonlinear Dependence in the Credit Default Swap Market
Authors: Moloney Kitty , Raghavendra Srinivas
Published: May 2011

The objective of this paper is to test for nonlinear dependence in the
GARCH residuals of a number of asset classes using nonlinear dynamic
tools. The equity and bond market samples appear to be independent once
GARCH has been applied, but evidence of nonlinear dependence in the
CDS GARCH residuals is found. The sensitivity of this result is analysed
by changing the specifications of the GARCH model, and the robustness of
the result is verified by applying additional tests of nonlinearity. Evidence
of nonlinear dependence in the GARCH residuals of CDS contracts has
implications for the accurate modeling of the marginal distribution of
the CDS market, for pricing of CDS contracts, for estimating risk neutral
default probabilities in the bond market, as well as for bond market hedging
strategies.
Small Cell Ovarian Cancer in Adolescents: Report of Two Cases and Review of the Literature
Authors: Rovithi M. , Pallis A. G. , Kalykaki A. , Lagoudaki E. , Giannikaki L. , Stathopoulos E. N. , Relakis K. , Georgoulias V.
Published: May 2011

Ovarian small cell carcinoma is a rare and highly malignant neoplasm carrying a poor prognosis. Although combination chemotherapy remains the cornerstone of treatment due to the rarity of these tumors, no regimen can be recommended as standard of care although in the majority of cases platinum-based regimens are used. Herein, we report two cases of small cell carcinoma of the ovaries along with a review of the relevant literature.
Estimates of Exponential Stability for Solutions of Stochastic Control Systems with Delay
Authors: Dzhalladova Irada A. , Baštinec Jaromír , Diblík Josef , Khusainov Denys Y.
Published: May 2011

A nonlinear stochastic differential‐difference control system with
delay of neutral type is considered. Sufficient conditions for the exponential
stability are derived by using Lyapunov‐Krasovskii functionals of quadratic
form with exponential factors. Upper bound estimates for the exponential
rate of decay are derived.
Performance of an Ultrasonic Imaging System Based on a 45‐MHz Linear PVDF Transducer Array: A Numerical Study
Authors: Brodal Eivind , Melandsø Frank , Jacobsen Svein
Published: May 2011

New designs of high‐resolution ultrasonic imaging systems that operate in the 30–100 MHz
region, for example, those based on linear transducer systems, are currently being investigated for
medical purposes. Acoustic waves with frequencies in this range can detect microscopic
structures in human tissue but will typically only penetrate a few mm because of large
attenuation. However, this is sufficient for a diagnostic ultrasound scan of human skin.
The signal‐to‐noise ratio and the focusing properties of the scanner are critical factors in
dermatology, which are determined by the transducer design.
A linear pulsed PVDF transducer array with a center frequency around 45 MHz is studied
by applying numerical simulations, based on the finite element method (FEM), of this
electromechanical system. Tx‐beamforming properties of linear arrays with one, three, five,
and seven active elements are investigated at different depths. The image quality obtained
from synthetic Rx‐beamforming, using responses from five electrodes, is estimated from
reconstructed images of 25–100 μm thick objects. The axial and lateral resolutions of these
images are found to be similar with the Tx‐beamforming resolution parameters estimated
from the time‐derivative of the pressure beams.
Molecular Chaperones as a Common Set of Proteins That Regulate the Invasion Phenotype of Head and Neck Cancer
Authors: Chiu Ching-Chi , Lin Chien-Yu , Lee Li-Yu , Chen Yin-Ju , Lu Ya-Ching , Wang Hung-Ming , Liao Chun-Ta , Chang Joseph Tung-Chieh , Cheng Ann-Joy
Published: June 2011

Purpose: The goal of this study was to establish a common set of molecules that regulate cell invasion in head and neck cancer (HNC).

Experimental Design: Five invasive sublines derived from HNC cell lines were established using the Matrigel selection method. Proteomic technology, MetaCore algorithm, and reverse transcriptase-PCR methods were used to search for molecules that contribute to the invasion phenotype. Cellular functional analyses and clinical association studies were applied to examine the significance of the molecules.

Results: Fifty-two proteins were identified in more than two of the four independent proteomic experiments, including 10 (19%) molecular chaperones. Seven chaperones were confirmed to be differentially expressed in five sublines, Hsp90α, Hsp90β, Hsp90-B1/Gp96, Hsp70-A5/Grp78, and HYOU1, that upregulate, whereas Hsp60 and glucosidase-α neutral AB (GANAB) downregulate. Four molecules were further investigated. In all cell lines, knockdown of Hsp60 or GANAB and silencing of Gp96 or Grp78 considerably enhanced or reduced cell migration and invasion, respectively. Clinical association studies consistently revealed that low levels of Hsp60 or GANAB and high levels of Gp96 or Grp78 are significantly associated with advanced cancer (P < 0.001 to P = 0.047, respectively, for the four molecules) and poor survival (P < 0.001 to P = 0.025, respectively, for the four molecules).

Conclusion: Our study defined molecular chaperones as a common set of proteins that regulate the invasion phenotype of HNC. Loss of the tumor suppression function of Hsp60 or GANAB and acquisition of the oncogenic function of Gp96 or Grp78 contribute to aggressive cancers. These molecules may serve as prognostic markers and targets for cancer drug development. Clin Cancer Res; 17(14); 4629–41. ©2011 AACR.
Merkel Cell Polyomavirus Infection, Large T Antigen, Retinoblastoma Protein and Outcome in Merkel Cell Carcinoma
Authors: Sihto Harri , Kukko Heli , Koljonen Virve , Sankila Risto , Böhling Tom , Joensuu Heikki
Published: June 2011

Purpose: Merkel cell carcinoma (MCC) is rare skin cancer that is often associated with Merkel cell polyomavirus (MCPyV) infection. Polyomaviruses repress tumor suppressor proteins, thus influencing cell-cycle progression, but the effect of MCPyV on the key cell-cycle regulating proteins is poorly understood.

Experimental Design: We evaluated expression of the MCPyV large T-antigen (LTA), Ki-67, and the key putative tumor suppressor proteins, the retinoblastoma protein (RB and phospho-RB) and p53, and their regulatory proteins (cyclin D1, cyclin E, p16, p21, p27, and MDM2) by using immunohistochemistry from tumors of 91 MCC patients identified from a population-based nationwide cohort. Tumor MCPyV DNA was measured by using quantitative PCR, and TP53 mutations were identified with sequencing.

Results: MCPyV LTA expression was strongly associated with presence of MCPyV DNA in tumor, and it was almost invariably associated with tumor RB expression (P < 0.0001 for both comparisons). Both MCC LTA and RB expression were strongly associated with favorable MCC-specific and overall survival in univariable analyses (P ≤ 0.01 for all four analyses). Presence of MCPyV LTA was also associated with the female gender, the intermediate type of tumor histology, location of the tumor in a limb, cell proliferation rate, and absence of p53 expression. TP53 mutations were detected only in MCPyV DNA–negative tumors.

Conclusions: MCPyV DNA–positive MCC has several clinical and molecular features that differ from MCPyV DNA-negative cancers. MCPyV-associated MCCs express RB, but may not harbor TP53 mutations. These findings provide further support that MCPyV causes the majority of MCCs. Clin Cancer Res; 17(14); 4806–13. ©2011 AACR.
Molecular Genetic and Functional Characterization Implicate Muscle-Restricted Coiled-Coil Gene (
MURC
) as a Causal Gene for Familial Dilated Cardiomyopathy
Authors: Rodriguez Gabriela , Ueyama Tomomi , Ogata Takehiro , Czernuszewicz Grazyna , Tan Yanli , Dorn Gerald W. , Bogaev Roberta , Amano Katsuya , Oh Hidemasa , Matsubara Hiroaki , Willerson James T. , Marian Ali J.
Published: June 2011

Background—

Dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM) are classic forms of systolic and diastolic heart failure, respectively. Mutations in genes encoding sarcomere and cytoskeletal proteins are major causes of HCM and DCM.
MURC
, encoding muscle-restricted coiled-coil, a Z-line protein, regulates cardiac function in mice. We investigated potential causal role of
MURC
in human cardiomyopathies.

Methods and Results—

We sequenced
MURC
in 1199 individuals, including 383 probands with DCM, 307 with HCM, and 509 healthy control subjects. We found 6 heterozygous DCM-specific missense variants (p.N128K, p.R140W, p.L153P, p.S307T, p.P324L, and p.S364L) in 8 unrelated probands. Variants p.N128K and p.S307T segregated with inheritance of DCM in small families (χ
2
=8.5,
P
=0.003). Variants p.N128K, p.R140W, p.L153P, and p.S364L were considered probably or possibly damaging. Variant p.P324L recurred in 3 independent probands, including 1 proband with a
TPM1
mutation (p.M245T). A deletion variant (p.L232-R238del) was present in 3 unrelated HCM probands, but it did not segregate with HCM in a family who also had a
MYH7
mutation (p.L907V). The phenotype in mutation carriers was notable for progressive heart failure leading to heart transplantation in 4 patients, conduction defects, and atrial arrhythmias. Expression of mutant MURC proteins in neonatal rat cardiac myocytes transduced with recombinant adenoviruses was associated with reduced RhoA activity, lower mRNA levels of hypertrophic markers and smaller myocyte size as compared with wild-type MURC.

Conclusions—

MURC
mutations impart loss-of-function effects on MURC functions and probably are causal variants in human DCM. The causal role of a deletion mutation in HCM is uncertain.
Re-balancing China: Linking Internal and External Reforms
Authors: Yueh Linda
Published: May 2011

The re-balancing of the Chinese economy requires the linking of internal and external sector reforms. The shift toward greater domestic demand necessitates a series of measures, including the adjustment of interest rates and the exchange rate. A more balanced Chinese economy would generate more sustainable growth, particularly as global macroeconomic imbalances fall from their pre-crisis peak.
Validation of a Testbed as a Screening Tool for Telepresence Systems in Terms of Fine-Motor Performance
Authors: Geiger Lena
Published: May 2011

Telepresence systems have the potential to assume an important role in on-orbit servicing scenarios. Compared to manned missions, these systems offer a safer and less expensive way to operate in outer space. One of the main goals of telepresence research is to determine whether immersive telepresence systems are able to achieve a level of efficiency which is equal to that of astronauts in tasks that require fine motor movement and dexterity. In addressing this question, it is of relevance that astronauts' fine-motor skills are restricted by a range of factors including weightlessness and space suits. In order to compare in future studies the efficiency of a telepresence system and suited astronauts in performing fine-motor tasks, a testbed was developed with typical on-orbit servicing tasks which were designed to guarantee maximum external validity. An experimental study showed that the testbed is a valid measure of fine-motor skills. Two follow-up studies examined the potentially debilitating influence of a range of factors on fine-motor performance in extravehicular activities, such as a restricted field of view, a destabilized body posture, restricted mobility, and reduced haptic feedback. The results of these studies offer a basis for comparisons between the performance of common extravehicular activities and telepresence systems on fine-motor tasks.
Asymptomatic Carotid Artery Disease in Valvular Heart Surgery
Authors: Anselmi Amedeo , Gaudino Mario , Risalvato Nicola , Lauria Giuseppe , Glieca Franco
Published: June 2011

We evaluated the prevalence of asymptomatic carotid artery disease in patients scheduled for valvular cardiac surgery. Preoperative screening of the carotid arteries was performed. Among 1012 patients scheduled for valvular cardiac surgery, 267 (26.4%) had carotid stenosis graded >50%; 37 had carotid stenosis >70% and underwent combined valvular surgery and carotid endarterectomy (CEA); and 230 (86%) had carotid stenosis >50% to ≤69% and received valvular cardiac surgery under hypothermic cardiopulmonary bypass. Operative mortality and the rate of perioperative adverse neurological events were comparable among the groups. During 6.8 years of follow-up, patients with carotid stenosis not exceeding 69% at the time of surgery had CEA more frequently ( P < .05) and stroke/transient ischemic attack ([TIA] P < .05) versus patients treated with combined surgery. The prevalence of asymptomatic carotid stenosis is not negligible in patients undergoing isolated valvular surgery. Combined valvular and carotid surgery is safe and reduces the incidence of CEA and stroke/TIA during follow-up.
Effects of Spectral Manipulation on Nonindividualized Head-Related Transfer Functions (HRTFs)
Authors: So Richard H. Y. , Leung N. M. , Horner Andrew B. , Braasch Jonas , Leung K. L.
Published: June 2011

Background: Directional sounds simulated using nonindividualized head-related transfer functions (HRTFs) often result in front-back confusion.

Objective: This study was designed to examine how manipulating these nonindividualized HRTF spectra can reduce front-back confusion in headphone-simulated directional sounds.

Method: HRTFs of six ear-level directions were studied (angles of 0°, 45°, 135°, 180°, 225°, and 315°). The HRTF gains in each of six frequency bands (200 to 690 Hz, 690 to 2400 Hz, 2400 to 6500 Hz, 6500 to 10000 Hz, 10000 to 14000 Hz, and 14000 to 22000 Hz) were amplified or attenuated by 0, 12, or 18 dB. Each manipulated HRTF generated a directional sound stimulus. For this study, 32 participants were invited to localize the randomly ordered stimuli.

Results: The results indicate that a 12- or 18-dB manipulation of five of the six frequency bands produced significantly better directional accuracy, with significantly less front-back confusion. A reduction of up to 70% in localization error was obtained, along with 66% less front-back confusion. Significant interactions were found between the manipulation level and frequency.

Conclusion: A 12-dB spectral manipulation of selected HRTF frequency bands produces better directional accuracy.

Application: The results of this research could be applied to the development of tunable nonindividualized HRTFs for audio products.
An effective duplication-based task-scheduling algorithm for heterogeneous systems
Authors: Hosseinzadeh Mahsa , Shahhoseini Hadi Shahriar
Published: June 2011

One of the main issues in distributed computing systems is to determine an optimal task-scheduling method. In this paper, we present an effective algorithm to schedule a directed acyclic graph onto a heterogeneous distributed system, called the Earliest Starting and Finishing time Duplication based (ESFD) algorithm. Our proposed algorithm considers all parameters associated with the processors, the task, and its immediate predecessors to perform an effective task allocation. The ESFD algorithm is a three-phase algorithm with a dynamic phase to assign a priority to each task. Simulation results on both random graphs and real application graphs show that the network storage link, speedup, and efficiency generated by ESFD algorithm are better than those generated by the well-known Heterogeneous Critical Parent Trees, Heterogeneous Earliest Finish Time, and Levelized Heavily Communicating Node First algorithms.
LQG-MP: Optimized path planning for robots with motion uncertainty and imperfect state information
Authors: van den Berg Jur , Abbeel Pieter , Goldberg Ken
Published: June 2011

In this paper we present LQG-MP (linear-quadratic Gaussian motion planning), a new approach to robot motion planning that takes into account the sensors and the controller that will be used during the execution of the robot’s path. LQG-MP is based on the linear-quadratic controller with Gaussian models of uncertainty, and explicitly characterizes in advance (i.e. before execution) the a priori probability distributions of the state of the robot along its path. These distributions can be used to assess the quality of the path, for instance by computing the probability of avoiding collisions. Many methods can be used to generate the required ensemble of candidate paths from which the best path is selected; in this paper we report results using rapidly exploring random trees (RRT). We study the performance of LQG-MP with simulation experiments in three scenarios: (A) a kinodynamic car-like robot, (B) multi-robot planning with differential-drive robots, and (C) a 6-DOF serial manipulator. We also present a method that applies Kalman smoothing to make paths Ck-continuous and apply LQG-MP to precomputed roadmaps using a variant of Dijkstra’s algorithm to efficiently find high-quality paths.
Effects of Light on Cognitive Brain Responses Depend on Circadian Phase and Sleep Homeostasis
Authors: Vandewalle Gilles , Archer Simon N. , Wuillaume Catherine , Balteau Evelyne , Degueldre Christian , Luxen André , Dijk Derk-Jan , Maquet Pierre
Published: May 2011

Light is a powerful modulator of cognition through its long-term effects on circadian rhythmicity and direct effects on brain function as identified by neuroimaging. How the direct impact of light on brain function varies with wavelength of light, circadian phase, and sleep homeostasis, and how this differs between individuals, is a largely unexplored area. Using functional MRI, we compared the effects of 1 minute of low-intensity blue (473 nm) and green light (527 nm) exposures on brain responses to an auditory working memory task while varying circadian phase and status of the sleep homeostat. Data were collected in 27 subjects genotyped for the PER3 VNTR (12 PER35/5 and 15 PER34/4) in whom it was previously shown that the brain responses to this task, when conducted in darkness, depend on circadian phase, sleep homeostasis, and genotype. In the morning after sleep, blue light, relative to green light, increased brain responses primarily in the ventrolateral and dorsolateral prefrontal cortex and in the intraparietal sulcus, but only in PER34/4 individuals. By contrast, in the morning after sleep loss, blue light increased brain responses in a left thalamofrontoparietal circuit to a larger extent than green light, and only so in PER35/5 individuals. In the evening wake maintenance zone following a normal waking day, no differential effect of 1 minute of blue versus green light was observed in either genotype. Comparison of the current results with the findings observed in darkness indicates that light acts as an activating agent particularly under those circumstances in which and in those individuals in whom brain function is jeopardized by an adverse circadian phase and high homeostatic sleep pressure.
Resveratrol Dietary Supplementation Shortens the Free-Running Circadian Period and Decreases Body Temperature in a Prosimian Primate
Authors: Pifferi Fabien , Dal-Pan Alexandre , Menaker Michael , Aujard Fabienne
Published: May 2011

Resveratrol (RSV) is a dietary polyphenolic compound with several positive effects on metabolic functions and longevity. We tested the effect of RSV on the circadian clock in a nonhuman primate, the gray mouse lemur. The impact of a 2-week dietary supplementation of RSV on the rhythms of locomotor activity and body temperature in constant dark conditions (DD) was investigated in young ( n = 7) and old ( n = 6) animals. RSV supplementation followed 2 weeks in DD under normal diet (CTL). In both young and old animals receiving RSV, we observed a shortening of the free-running period compared to those under CTL (-15 minutes in young animals and -45 minutes in old animals), accompanied by a lower mean body temperature in both age groups and decreased locomotor activity in young animals. Thus, RSV is a food component capable of influencing a primate’s circadian clock. This property may be of interest clinically in the context of the treatment of circadian disruption and in the context of the effects of RSV ingestion on health.
Human Diurnal Preference and Circadian Rhythmicity Are Not Associated with the CLOCK 3111C/T Gene Polymorphism
Authors: Chang Anne-Marie , Buch Alison M. , Bradstreet Dayna S. , Klements David J. , Duffy Jeanne F.
Published: May 2011

Genetic association studies of the CLOCK 3111C/T polymorphism and diurnal preference have yielded conflicting results since the first report that the 3111C allele was associated with eveningness. The goal of the present study was to investigate the association of this polymorphism with diurnal preference and circadian physiology in a group of 179 individuals, by comparing the frequency of the 3111C allele to diurnal preference, habitual sleep timing, circadian phase markers, and circadian period. We did not find a significant association between this allele and morningness/eveningness or any circadian marker.
Cyclic AMP Signaling Control of Action Potential Firing Rate and Molecular Circadian Pacemaking in the Suprachiasmatic Nucleus
Authors: Atkinson Susan E. , Maywood Elizabeth S. , Chesham Johanna E. , Wozny Christian , Colwell Christopher S. , Hastings Michael H. , Williams Stephen R.
Published: May 2011

Circadian pacemaking in suprachiasmatic nucleus (SCN) neurons revolves around transcriptional/posttranslational feedback loops, driven by protein products of “clock” genes. These loops are synchronized and sustained by intercellular signaling, involving vasoactive intestinal peptide (VIP) via its VPAC2 receptor, which positively regulates cAMP synthesis. In turn, SCN cells communicate circadian time to the brain via a daily rhythm in electrophysiological activity. To investigate the mechanisms whereby VIP/VPAC2/cAMP signaling controls SCN molecular and electrical pacemaking, we combined bioluminescent imaging of circadian gene expression and whole-cell electrophysiology in organotypic SCN slices. As a potential direct target of cAMP, we focused on hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels. Mutations of VIP-ergic signaling compromised the SCN molecular pacemaker, diminishing the amplitude and intercellular synchrony of circadian gene expression. These deficits were transiently reversed by elevation of cAMP. Similarly, cellular synchrony in electrical firing rates was lost in SCN slices lacking the VPAC2 receptor for VIP. Whole-cell current-clamp recordings in wild-type (WT) slices revealed voltage responses shaped by the conductance Ih, which is mediated by HCN channel activity. The influence of Ih on voltage responses showed a modest peak in early circadian day, identifying HCN channels as a putative mediator of cAMP-dependent circadian effects on firing rate. Ih, however, was unaffected by loss of VIP-ergic signaling in VPAC2-null slices, and inhibition of cAMP synthesis had no discernible effect on Ih but did suppress gene expression and SCN firing rates. Moreover, only sustained but not acute, pharmacological blockade of HCN channels reduced action potential (AP) firing. Thus, our evidence suggests that in the SCN, cAMP-mediated signaling is not a principal regulator of HCN channel function and that HCN is not a determinant of AP firing rate. VIP/cAMP-dependent signaling sustains the SCN molecular oscillator and action potential firing via mechanisms yet to be identified.
Malnutrition Causing Neonatal Dyslipidemia
Authors: Inaba Fernandes Vanessa Pacini , de Faria Eliana Cotta , Bellomo‐Brandão Maria Angela , Negrão Nogueira Roberto José
Published: June 2011

Lipid abnormalities in children have become more common in recent decades. This trend is related to the increase in overweight and obesity. The 2002 National Health and Nutrition Examination Survey reported that the percentage of risk for overweight and overweight in children aged > 6 years is 31%, higher than the previous surveys. Serum lipids tend to increase quickly up to 6 months of age and reach values very close to adult values by age 2. As suggested by the American Heart Association, serum lipid values for children and adolescents (2‐19 years old) are considered abnormal when total cholesterol is >200 mg/dL, high‐density lipoprotein is <35 mg/dL, low‐density lipoprotein is >130 mg/dL, and triglycerides are >150 mg/dL. Dyslipidemia can be found in patients with malnutrition, a severe condition that needs prompt nutrition intervention. This report describes a case of malnutrition causing severe dyslipidemia in a newborn. Primary dyslipidemia was excluded by the presence of primary malnutrition, normal response to a postheparin lipoprotein lipase activity test, a favorable clinical course after nutrition intervention, and relatives’ blood lipid levels close to normal that did not indicate familial dyslipidemia. The child was fed fat‐free milk formula supplemented with medium‐chain triglycerides and had adequate weight gain with a decrease in blood lipids. Subsequently the formula was changed to regular milk‐based formula, and the child maintained adequate growth rate. Although blood lipids never returned to normal values for age and sex, they were lower than before treatment.
Racism and Disparities in Women’s Use of the Depo-Provera Injection in the Contemporary USA
Authors: Volscho Thomas W.
Published: June 2011

In the 1960s and 1970s widespread reports of sterilization abuse directed at women of color in the USA emerged. While such cases involved coercive or deceptive surgical sterilizations, new contraceptive technologies that temporarily sterilize women (Norplant and Depo-Provera) were approved for use in the US market by the state in the 1990s. In this study, I offer the concept of sterilization racism to explain the pattern and prevalence of ‘racial’/ethnic disparities in Depo-Provera use among non-sterile US women age 18 to 44. The data used for the statistical analyses come from the 2002 and 2004 Behavioral Risk Factor Surveillance System (BRFSS) survey. After adjustment for potential confounders, I find that African American and American Indian women are more likely to use Depo-Provera than European American women. I also include a discussion of the complexities of studying racism with data on ‘racial’/ethnic disparities that were not designed for this purpose.
Laser power requirement for cutting thick-section steel and effects of processing parameters on mild steel cut quality
Authors: Wandera C , Kujanpää V , Salminen A
Published: May 2011

The high-power fibre laser presents a possibility for the application of solid-state lasers in thick-section metal cutting, a field which has been dominated by high-power CO2 lasers. The current paper presents the lumped-parameter formulation of the laser power requirement as a function of cutting speed for oxygen-assisted laser cutting of mild steel and nitrogen-assisted laser cutting of stainless steel. The calculated laser power requirement is compared with the incident laser power used in the cutting of 15 mm mild steel with oxygen assist gas and 10 mm stainless steel with nitrogen assist gas using a multi-mode 5 kW fibre laser and a 4 kW CO2 laser. The incident laser power required for cutting at a given cutting speed is found to be lower for fibre laser cutting than for the CO2 laser cutting, indicating a higher absorption of the fibre laser beam. The effects of process parameters on the cut kerf quality in mild steel laser cutting with oxygen assist gas using the high-power fibre laser are presented. The critical process parameters affecting the quality of the cutting process and the resulting cut kerf are the cutting speed, oxygen pressure, and nozzle diameter.
Energy-saving effect of a factory ceiling incorporating microencapsulated Phase Change Materials
Authors: Lai C-M
Published: June 2011

The enhancement of thermal-insulation capability of rooftop and exterior wall are key issues in energy conservation for buildings. The objective of this study is to provide insights into thermal-insulation alternatives that will improve the thermal performance of rooftop constructions. In doing so, experiments have been performed for investigating the energy-saving effect of adding microencapsulated Phase Change Materials (mPCM) to a conventional factory ceiling (gypsum board). The average energy-saving effect at the entire heat absorption stage of a mPCM gypsum board compared with a conventional gypsum board is 31.7 per cent.
Nasogastric feeding at the end of life: A virtue ethics approach
Authors: Krishna Lalit
Published: June 2011

The use of Nasogastric (NG) feeding in the provision of artificial nutrition and hydration at the end of life has, for the most part, been regarded as futile by the medical community. This position has been led chiefly by prevailing medical data. In Singapore, however, there has been an increase in its utilization supported primarily by social, religious and cultural factors expressly to prolong life of the terminally ill patient. Here this article will seek to review the ethical and clinical impact of this treatment and provide some understanding for such decisions in the light of the Duty of Palliative Care [DoPC]. Complemented by virtue ethics theory, the DoPC highlights and seeks to realize the individual case specific goals of care that maximize comfort and quality of life of the patient in the face of rapid attenuation of treatment options and the eminence of the final outcome by considering each of these factors individually in order to provide the best outcome for the patient and the family.
Effectiveness of University Bridging Programs in Preparing Students for University Education
Authors: Ssempebwa Jude , Eduan Wilson , Mulumba Fawz Nassir
Published: June 2011

Study abroad brings several advantages to students, universities, countries, and academe. However, across countries with incongruent preuniversity education structures, some students are denied admission to foreign universities, due to gaps in their admissibility. Some institutions offer university bridging programs, to enhance the admissibility of these students to the required level. Nonetheless, the efficacy of these programs, in closing the competence gap between their attendees and conventional enrolees, is the subject of much controversy—albeit neither their proponents nor critics have provided empirical evidence to support their side of the argument. To plug this gap, this study examined the academic performance differentials between students enrolled through the programs and those admitted through conventional routes, taking the case of Kampala International University. The findings were that, on the whole, there is no significant difference between the two, meaning that the programs are effective in preparing their attendees for university education.
Sexual Violence Victimization of Women
Authors: Basile Kathleen C. , Smith Sharon G.
Published: June 2011

Sexual violence is a serious public health problem with devastating health-related consequences. In this article, the authors review the prevalence, characteristics, vulnerability factors for, and impacts of sexual violence victimization for women. Some key factors are reviewed that have been shown to increase vulnerability for victimization, including certain demographic characteristics, previous victimization, and use of drugs or alcohol. The impacts of rape and other sexual violence are described, including physical and sexual health; psychological, social, and societal impacts; as well as impact on risky health behaviors. The authors conclude with a discussion of the public health approach to sexual violence, primary prevention, the relevance of sexual violence research for health care practitioners, and recommendations for health care practice.
The effect of peel ply layer on hole integrity when drilling carbon fibre-reinforced plastic
Authors: Shyha I S , Soo S L , Aspinwall D K , Bradley S
Published: June 2011

Fibre/matrix delamination is a common problem when cutting carbon fibre-reinforced plastic (CFRP) that can have a detrimental effect on workpiece mechanical properties and hence compromise the in-service performance of the composite part. The present paper details experimental results when drilling small holes (1.5 mm diameter) through backed and un-backed CFRP laminates using tungsten carbide twist drills to determine the effect of peel ply layers (∼100 µm thick nylon sheet attached on both sides of 3 mm thick laminates) on hole entry and exit delamination. Considerable reduction in damage relating to fuzzing, spalling, edge chipping, and delamination was observed when drilling the nylon-backed CFRP material, with scanning electron micrographs showing significantly inferior hole quality for the corresponding un-backed workpieces, particularly at hole exit.
ISO/TS 16949: analysis of the diffusion and current trends
Authors: Franceschini F , Galetto M , Maisano D A , Mastrogiacomo L
Published: May 2011

The automotive industry has always shown a particular interest in quality management systems, which resulted in the development of several different specific standards. As a result of this, by the mid-1980s, automotive suppliers were subject to numerous national and customer-specific regulations. The proliferation of these standards and the need to create a single reference model led to Technical Specification (TS) 16949, an International Organization for Standardization (ISO) technical specification aimed at representing a comprehensive quality management system for the global automotive industry. Since its early introduction, TS 16949 has encountered a certain success thanks to its feature of unifying and harmonizing the already existing standards. This paper studies the global evolution and diffusion of this technical specification, observing its impact on local economies. The findings are supported by empirical data.