bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance study of a wireless mobile ad hoc network with orientation‐dependent internode communication scheme
Authors: Kostin Alexander , Oz Gurcu , Haci Huseyin 
Published: May 2012

SUMMARYA Petri‐net‐based simulation model of a wireless mobile ad hoc network is developed and studied. The model covers all the fundamental aspects of behaviour of such a network and uses a novel scheme of orientation‐dependent (or sector‐dependent) internode communication, with random states of links. The proposed scheme enables representation of reliability aspects of wireless communication, such as fading effects, interferences, presence of obstacles and weather conditions in a general and rather easy way. The simulation model was implemented in terms of a class of extended Petri nets to explicitly represent parallelism of events and processes in the WLAN as a distributed system. In the simulation, the behaviour of four fundamental performance metrics — packet delivery ratio, average number of hops, relative network traffic and end‐to‐end delay — were investigated with varying distance of transmission and different combinations of model parameters. Copyright © 2012 John Wiley & Sons, Ltd.
Nanoemulsions for the Determination of the Antioxidant Capacity of Oils by an Electrochemical Method
Authors: Benedetti Simona , Cosio Maria Stella , Scampicchio Matteo , Mannino Saverio 
Published: May 2012

AbstractThe paper describes a rapid and simple method for the evaluation of the antioxidant capacity in oil in water nanoemulsion. This procedure does not require extensive sample treatment and, most important, does not use any organic solvent for dissolution of the fatty matrix. The nanoemulsions were directly injected in a flow injection (FI) system with an electrochemical detector equipped with a glassy carbon working electrode operating amperometrically at a potential of +0.8 V (vs. Ag/AgCl). Results obtained were compared with those obtained by the Oxygen Radical Absorbance Capacity (ORAC) assay.
POOLING VERSUS MODEL SELECTION FOR NOWCASTING GDP WITH MANY PREDICTORS: EMPIRICAL EVIDENCE FOR SIX INDUSTRIALIZED COUNTRIES
Authors: Kuzin Vladimir , Marcellino Massimiliano , Schumacher Christian 
Published: May 2012

SUMMARYThis paper discusses pooling versus model selection for nowcasting with large datasets in the presence of model uncertainty. In practice, nowcasting a low‐frequency variable with a large number of high‐frequency indicators should account for at least two data irregularities: (i) unbalanced data with missing observations at the end of the sample due to publication delays; and (ii) different sampling frequencies of the data. Two model classes suited in this context are factor models based on large datasets and mixed‐data sampling (MIDAS) regressions with few predictors. The specification of these models requires several choices related to, amongst other things, the factor estimation method and the number of factors, lag length and indicator selection. Thus there are many sources of misspecification when selecting a particular model, and an alternative would be pooling over a large set of different model specifications. We evaluate the relative performance of pooling and model selection for nowcasting quarterly GDP for six large industrialized countries. We find that the nowcast performance of single models varies considerably over time, in line with the forecasting literature. Model selection based on sequential application of information criteria can outperform benchmarks. However, the results highly depend on the selection method chosen. In contrast, pooling of nowcast models provides an overall very stable nowcast performance over time. Copyright © 2012 John Wiley & Sons, Ltd.
Parathyroid hormone induces differentiation of mesenchymal stromal/stem cells by enhancing bone morphogenetic protein signaling
Authors: Yu Bing , Zhao Xiaoli , Yang Chaozhe , Crane Janet , Xian Lingling , Lu William , Wan Mei , Cao Xu 
Published: May 2012

Abstract
Parathyroid hormone (PTH) stimulates bone remodeling and induces differentiation of bone marrow mesenchymal stromal/stem cells (MSCs) by orchestrating activities of local factors such as bone morphogenetic proteins (BMPs). The activity and specificity of different BMP ligands are controlled by various extracellular antagonists that prevent binding of BMPs to their receptors. Low-density lipoprotein receptor-related protein 6 (LRP6) has been shown to interact with both the PTH and BMP extracellular signaling pathways by forming a complex with parathyroid hormone 1 receptor (PTH1R) and sharing common antagonists with BMPs. We hypothesized that PTH-enhanced differentiation of MSCs into the osteoblast lineage through enhancement of BMP signaling occurs by modifying the extracellular antagonist network via LRP6. In vitro studies using multiple cell lines, including Sca-1+CD45–CD11b–MSCs, showed that a single injection of PTH enhanced phosphorylation of Smad1 and could also antagonize the inhibitory effect of noggin. PTH treatment induced endocytosis of a PTH1R/LRP6 complex and resulted in enhancement of phosphorylation of Smad1 that was abrogated by deletion of PTH1R, β-arrestin, or chlorpromazine. Deletion of LRP6 alone led to enhancement of pSmad1 levels that could not be further increased with PTH treatment. Finally, knockdown of LRP6 increased the exposure of endogenous cell-surface BMP receptor type II (BMPRII) significantly in C2C12 cells, and PTH treatment significantly enhanced cell-surface binding of 125I-BMP2 in a dose- and time-dependent manner, implying that LRP6 organizes an extracellular network of BMP antagonists that prevent access of BMPs to BMP receptors. In vivo studies in C57BL/6J mice and of transplanted green fluorescent protein (GFP)-labeled Sca-1+CD45–CD11b–MSCs into the bone marrow cavity of Rag2−/− immunodeficient mice showed that PTH enhanced phosphorylation of Smad1 and increased commitment of MSCs to osteoblast lineage, respectively. These data demonstrate that PTH enhancement of MSC differentiation to the osteoblast lineage occurs through a PTH- and LRP6-dependent pathway by endocytosis of the PTH1R/LRp6 complex, allowing enhancement of BMP signaling. © 2012 American Society for Bone and Mineral Research.
Four‐dimensional phase contrast MRI With accelerated dual velocity encoding
Authors: Nett Elizabeth J. , Johnson Kevin M. , Frydrychowicz Alex , Del Rio Alejandro Munoz , Schrauben Eric , Francois Christopher J. , Wieben Oliver 
Published: May 2012

AbstractPurpose:To validate a novel approach for accelerated four‐dimensional phase contrast MR imaging (4D PC‐MRI) with an extended range of velocity sensitivity.Materials and Methods:4D PC‐MRI data were acquired with a radially undersampled trajectory (PC‐VIPR). A dual Venc (dVenc) processing algorithm was implemented to investigate the potential for scan time savings while providing an improved velocity‐to‐noise ratio. Flow and velocity measurements were compared with a flow pump, conventional 2D PC MR, and single Venc 4D PC‐MRI in the chest of 10 volunteers.Results:Phantom measurements showed excellent agreement between accelerated dVenc 4D PC‐MRI and the pump flow rate (R2 ≥ 0.97) with a three‐fold increase in measured velocity‐to‐noise ratio (VNR) and a 5% increase in scan time. In volunteers, reasonable agreement was found when combining 100% of data acquired with Venc = 80 cm/s and 25% of the high Venc data, providing the VNR of a 80 cm/s acquisition with a wider velocity range of 160 cm/s at the expense of a 25% longer scan.Conclusion:Accelerated dual Venc 4D PC‐MRI was demonstrated in vitro and in vivo. This acquisition scheme is well suited for vascular territories with wide ranges of flow velocities such as congenital heart disease, the hepatic vasculature, and others. J. Magn. Reson. Imaging 2012. © 2012 Wiley Periodicals, Inc.
Gradient echo imaging
Authors: Markl Michael , Leupold Jochen 
Published: May 2012

AbstractMagnetic resonance imaging (MRI) based on gradient echoes is used in a wide variety of imaging techniques and clinical applications. Gradient echo sequences form the basis for an essential group of imaging methods that find widespread use in clinical practice, particularly when fast imaging is important, as for example in cardiac MRI or contrast‐enhanced MR angiography. However, the term “gradient echo sequence” is somewhat unspecific, as even images acquired with the most common sequences employing the gradient echo for data acquisition can significantly differ in signal, contrast, artifact behavior, and sensitivity to, eg, flow. This is due to the different use of sequence timing and basic sequence building blocks such as spoiler gradients or specific radiofrequency (RF) pulse phase patterns. In this article the basic principles of gradient echo formation compared to spin echo imaging are reviewed and the properties of gradient echo imaging in its simplest form (TR ≫T2) are described. Further, the most common three variants of fast gradient echo sequences (TR <T2), namely, unbalanced gradient echo, RF spoiled gradient echo, and balanced steady state free precession; are discussed. For each gradient echo sequence type, examples of applications exploiting the specific properties of the individual technique are presented. J. Magn. Reson. Imaging 2012;35:1274–1289. © 2012 Wiley Periodicals, Inc.
Association of E‐selectin gene polymorphisms with ischemic stroke in a Chinese Han population
Authors: Zhao Dong‐Xue , Feng Juan , Cong Shu‐Yan , Zhang Wei 
Published: May 2012

AbstractThe E‐selectin gene, a member of the selectin superfamily of adhesion molecules, plays an important role in the pathogenesis of thrombovascular diseases. The present study was designed to investigate the potential relationship between E‐selectin gene polymorphisms and ischemic stroke in a Chinese Han population. Three hundred fourteen ischemic stroke patients and 389 unrelated healthy controls were recruited for the study. Three single‐nucleotide polymorphisms (SNPs)—rs1805193(G98T), rs5361(A561C), and rs5355(C1839T)—in the exon region of the E‐selectin gene, were genotyped using a Multiplex SNaPshot sequencing assay. The data showed that the genotype and allele frequencies of G98T and C1839T SNP were similar in both ischemic stroke patients and the controls. In contrast, the frequency of both the AC genotype and the C allele of A561C was significantly higher in ischemic stroke patients than in healthy controls (P = 0.001, P < 0.001, respectively). After adjusting for other risk factors (such as hypertension, diabetes, tobacco smoking, and alcohol consumption), the E‐selectin gene AC genotype and C allele of A561C were still associated with a risk of ischemic stroke (odds ratio [OR] = 2.73, 95% confidence interval (CI): 1.29–5.76, P = 0.008; OR = 2.80, 95% CI: 1.58–4.94, P < 0.001, respectively). Our current study demonstrates that the E‐selectin SNP A561C is associated with increased risk for the development of ischemic stroke in this subset of the Han Chinese population. © 2012 Wiley Periodicals, Inc.
CcpA and three newly identified proteins are involved in biofilm development in Lactobacillus plantarum
Authors: Muscariello Lidia , Marino Carlo , Capri Ugo , Vastano Valeria , Marasco Rosangela , Sacco Margherita 
Published: May 2012

AbstractThe aim of this study was to identify genes involved in biofilm development in the probiotic lactic acid bacterium Lactobacillus plantarum. The ability of L. plantarum LM3 and of some derivative mutant strains to form biofilm has been investigated. Biofilm microtitre plate assays showed that L. plantarum LM3‐2, carrying a null mutation in the ccpA gene, coding the CcpA master regulator, was partially impaired in biofilm production compared to wild type (LM3). Moreover, we found three genes in the L. plantarum genome, hereby named flmA, flmB, and flmC, whose deduced amino acid sequences show significant identity with the Streptococcus mutans BrpA (biofilm regulatory protein A). We investigated the role of FlmA, FlmB, and FlmC in biofilm formation by isolating strains carrying null mutations in the corresponding genes. Our results suggest involvement of the Flm proteins in biofilm development. Moreover, transcriptional studies show that expression of flmA, flmB, and flmC is under the control of CcpA. These results, together with the reduced ability of LM3‐2 (ccpA1) to form biofilm, strongly suggest a positive role of the master regulator CcpA in biofilm development.
The apoptosis pathway and the genetic predisposition to Achilles tendinopathy
Authors: Nell Erica‐Mari , van der Merwe Lize , Cook Jill , Handley Christopher J. , Collins Malcolm , September Alison V. 
Published: May 2012

AbstractAchilles tendinopathy (AT) is a degenerative condition for which several risk factors have been implicated including components of the inflammatory pathway. The aim was to assess functional variants within genes encoding components of the apoptosis signaling cascade and the effectiveness of a polygenic apoptosis profile to capture tendinopathy (TEN) risk. A total of 358 unaffected control (CON) participants [159 South Africa (SA CON) and 199 Australia (AUS CON)] and 166 affected AT (TEN) participants (87 SA TEN and 79 AUS TEN) were genotyped for four variants [CASP8 (rs384129), CASP8 (rs1045485), NOS3 (rs1799983), and NOS2 (rs2779249)]. Logistic regression was used to derive risk models for AT. A receiver operator characteristic (ROC) curve was plotted to determine the effectiveness of a model to capture AT risk. This study indicates the independent association of CASP8_rs1045485 and CASP8_rs3834129 as well as their haplotype with AT risk and the identification of an optimal model which included genetic loci CASP8_rs384129 and CASP8_rs1045485 together with sex to capture AT risk in both SA and AUS. Collectively, these results further implicate the apoptosis signaling cascade as one of the biological pathways involved in the development of AT. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1719–1724, 2012
In situ Raman monitoring of materials under irradiation: study of uranium dioxide alteration by water radiolysis
Authors: Canizarès A. , Guimbretière G. , Tobon Y. A. , Raimboux N. , Omnée R. , Perdicakis M. , Muzeau B. , Leoni E. , Alam M. S. , Mendes E. , Simon D. , Matzen G. , Corbel C. , Barthe M. F. , Simon P. 
Published: May 2012

In situ Raman scattering studies allow following real‐time evolutions of volume or surface structures under extreme conditions. In nuclear materials sciences, ion irradiation‐induced atomic organization modification and water radiolysis are of a major interest. In order to better understand these phenomena, we have developed an in situ versatile portable Raman spectroscopy system coupled with a cyclotron accelerator, allowing monitoring of a solid/liquid interface under irradiation and thus giving access to effects of radiolysis. The different parts of the system and their improvements are described in details.The system efficiency is highlighted by a comparative study of the time dependence of UO2 surface modification induced, on one hand by contact with water under irradiation by 5 MeV He2+ particles, and on the other hand by pure chemical alteration, through contact with a hydrogen peroxide solution. Copyright © 2012 John Wiley & Sons, Ltd.
Epidemiology of pancreatic cancer and the role of family history
Authors: Olson Sara H. , Kurtz Robert C. 
Published: May 2012

AbstractPancreatic cancer is a lethal disease for which only a small number of risk factors have been identified. In addition to older age, male gender, and black race, risk factors include smoking, obesity, long‐standing diabetes and pancreatitis, and heavy alcohol use; allergies such as hay fever are related to lowered risk. Several genetic syndromes increase risk of pancreatic cancer. Work on more common genetic variants promises to reveal more potentially important genetic associations. J. Surg. Oncol. 2013;107:1–7. © 2012 Wiley Periodicals, Inc.
Dissociative experiences as mediators between childhood trauma and auditory hallucinations
Authors: Perona‐Garcelán Salvador , Carrascoso‐ López Francisco , García‐Montes José M. , Ductor‐Recuerda María Jesús , López Jiménez Ana Ma , Vallina‐Fernández Oscar , Pérez‐Álvarez Marino , Gómez‐Gómez María Teresa 
Published: May 2012

AbstractThe purpose of this work was to study the relationship between reported traumatic experiences in childhood and positive psychotic symptoms. We hypothesized that dissociative experiences were potential mediators between childhood trauma and hallucinations, but not delusions. The sample comprised 71 patients diagnosed with psychoses. They were assessed with the Dissociative Experiences Scale (DES‐II; Carlson & Putnam, 1993), a questionnaire on trauma (TQ; Davidson, Hughes, & Blazer, 1990), and the Positive and Negative Syndrome Scale (PANSS; Kay, Opler, & Lindenmayer, 1988) delusions and hallucinations items. The results showed that childhood trauma was positively associated with the dissociation scale scores (r = .40) and also the hallucination (r = .36) and delusions scale scores (r = .32). Furthermore, it was demonstrated that the dissociation variable was a potential mediator between childhood trauma and hallucinations, but not between childhood trauma and delusions. Of the 3 DES‐II factors, only depersonalization showed a mediating relationship between childhood trauma and hallucinations. The main conclusion is that the impact of childhood trauma on hallucinations may not simply be direct, but mediated by dissociative experiences, especially depersonalization. Clinical implications are also briefly discussed.
Spinal charcot‐marie‐tooth disease: A reappraisal
Authors: Devic Perrine , Petiot Philippe , Mauguière François 
Published: May 2012

AbstractIntroduction: Distal hereditary motor neuropathy (dHMN) is characterized by isolated distal muscle atrophy without sensory deficit. Nevertheless, clinical sensory loss has been reported despite preserved sensory nerve conduction in a few patients, thus differentiating these cases from the classical type 2 Charcot‐Marie‐Tooth disease (CMT2). Methods: We report 4 patients who presented with clinical sensory and motor neuropathy and normal peripheral sensory nerve conduction studies and were investigated with complete electrophysiological studies, including somatosensory evoked potentials (SEP). Results: These patients had a clinical presentation of classical CMT with isolated axonal motor neuropathy suggestive of dHMN. Interestingly, tibial nerve SEPs showed abnormalities suggestive of proximal involvement of dorsal roots that may explain the clinical somatosensory disturbances. Conclusions: These cases support the concept of spinal CMT that should be recognized as an intermediate form between dHMN and CMT2. SEP recording was helpful in defining a more precise phenotype of spinal CMT. Muscle Nerve 46: 603–607, 2012
Comparative experimental measurements of jute fiber/polypropylene and coir fiber/polypropylene composites as ionizing radiation
Authors: Zaman Haydar U. , Khan Mubarak A. , Khan Ruhul A. 
Published: May 2012

AbstractJute and coir fiber‐reinforced polypropylene (PP) composites (45 wt% fiber) were prepared by compression molding. Composites were fabricated with irradiated jute fiber/irradiated PP and irradiated coir fiber/irradiated PP at different doses (250–1,000 krad). It was revealed that jute‐based composites had better mechanical properties as compared to coir‐based composites. Interfacial shear strength of jute/PP and coir/PP systems was measured by using the single‐fiber fragmentation test. Scanning electron microscopy investigation shows poor fiber matrix adhesion for coir‐based composites than that of jute‐based composites. Water uptake and soil degradation tests of the composites were also performed. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Isothermal crystallization and melting behaviors of nano TiO2‐modified polypropylene/polyamide 6 blends
Authors: Ou Baoli , Ou Yangjian , Li Duxin , Jing Bo , Gao Yong , Zhou Zhihua , Liu Qingquan 
Published: May 2012

AbstractTitanium dioxide (TiO2) nanoparticles were functionalized with toluene‐2,4‐diisocyanate and then polypropylene/polyamide 6/(PP/PA6) blends containing functionalized‐TiO2 were prepared using a twin screw extruder. Isothermal crystallization and melting behavior of the as‐prepared composites were investigated using differential scanning calorimetry and wide‐angle X‐ray diffraction. Isothermal crystallization analysis shows that the TiO2 nanoparticles have two effects on PP/PA6 blends, i.e., it can favor the improvement of crystallization ability and decrease the crystallization rate of PP/PA6 blends. The improvement of crystallization ability is superior over decreasement of crystallization rate of PA6 chains caused by TiO2, therefore PA6 in PP/PA6/TiO2 nanocomposites have higher crystallization rate than that of PA6 in pure PP/PA6 blends, which indicated TiO2 nanoparticles favored the crystallization of PA6. The TiO2 nanoparticles show no effects on the equilibrium melting temperature (T) values of PP phase but decreases the T values of PA6 phase. In addition, the TiO2 nanoparticles did not change the crystalline polymorph of PP/PA6 blends basically; however, favored the formation of β‐PP. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Study on the Range of Particles Size Measured by Backscattering Method in Visual‐infrared Incident Spectrum
Authors: Xing Jian , Sun Weimin , Sun Xiaogang , Rana R. S. 
Published: May 2012

AbstractFor the measurement of particles size with backscattering method, the suitable range of particles size measurement have been presented by independent algorithm in Visual‐infrared incident spectrum. We defined the range according to the retrieved results based on the analysis and comparison to many kinds of R‐R distribution function. The simulation computation results showed that the particles size measurement range is from 0.05 μm to 18 μm with incident spectrum from 0.4 μm to 2 μm and different refractive index. The results retrieved were satisfied even if 1 % noise was added into the backscattering intensity.
Electromagnetic inductance plethysmography to measure tidal breathing in preterm and term infants
Authors: Pickerd N. , Williams E.M. , Kotecha S. 
Published: May 2012

AbstractTidal breathing measurements which provide a non‐invasive measure of lung function in preterm and term infants are particularly useful to guide respiratory support. We used a new technique of electromagnetic inductance plethysmography (EIP) to measure tidal breathing in infants between 32 and 42 weeks postconceptional age (PCA). Tidal breathing was measured in 49 healthy spontaneously breathing infants between 32 and 42 weeks PCA. The weight‐corrected tidal volume (VT) and minute volume (MV) decreased with advancing PCA (VT 6.5 ± 1.5 ml/kg and MV 0.44 ± 0.04 L/kg/min at 32–33 weeks, respectively; 6.3 ± 0.9 ml/kg and 0.38 ± 0.02 L/kg/min at 34–36 weeks; and 5.1 ± 1.1 ml/kg and 0.28 ± 0.02 L/kg/min at term, VT P < 0.001 and MV P < 0.01 for 32–33 weeks PCA vs. term; VT P = 0.016 and MV P = 0.015 for 34–36 weeks PCA vs. term). Respiratory frequency and the phase angle decreased significantly with advancing PCA but the flow parameter tPTEF/tE did not change significantly. Using a new technique to measure tidal breathing parameters in newborn infants, our data confirms its usability in clinical practice and establishes normative data which can guide future respiratory management of newborn infants. Pediatr Pulmonol. 2013; 48:160–167. © 2012 Wiley Periodicals, Inc.