bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics, Bifurcations and Normal Forms in Arrays of Magnetostrictive Energy Harvesters with All-to-All Coupling
Authors: Matus-Vargas Antonio , González-Hernandez Hugo G. , Chan Bernard S. , Palacios Antonio , Buono Pietro-Luciano , In Visarath , Naik Suketu , Phipps Alex , Longhini Patrick
Published: February 2015

Modeling and bifurcation analysis of an energy harvesting system composed of coupled resonators using the Galfenol-based magnetostrictive material are presented. The analysis in this work should be broad enough to be applicable to a large class of vibratory-based energy harvesting systems since various types of vibratory harvesters share the same normal forms, e.g. magnetostrictive and piezoelectric materials. A combined model of the mechanical and electrical domains of a single energy harvester is discussed first. Building on this model, the governing equations of the coupled system are derived, leading to a system of differential equations with an all-to-all coupling between the resonators. A bifurcation analysis of the system equations reveals different patterns of collective oscillations. Among the many different patterns, a synchronous state exists and it is stable over a broad region of parameter space. This pattern has the potential to yield significant increases in power output and it will be used as a starting point to guide future experimental work. A Hamiltonian approach is employed to study analytically the nature of the bifurcations and to calculate an expression for the onset of synchronization valid for any number of harvesters.
Actin Automata: Phenomenology and Localizations
Authors: Adamatzky Andrew , Mayne Richard
Published: February 2015

Actin is a globular protein which forms long filaments in the eukaryotic cytoskeleton, whose roles in cell function include structural support, contractile activity to intracellular signaling. We model actin filaments as two chains of one-dimensional binary-state semi-totalistic automaton arrays to describe hypothetical signaling events therein. Each node of the actin automaton takes state "0" (resting) or "1" (excited) and updates its state in discrete time depending on its neighbor's states. We analyze the complete rule space of actin automata using integral characteristics of space-time configurations generated by these rules and compute state transition rules that support traveling and mobile localizations. Approaches towards selection of the localization supporting rules using the global characteristics are outlined. We find that some properties of actin automata rules may be predicted using Shannon entropy, activity and incoherence of excitation between the polymer chains. We also show that it is possible to infer whether a given rule supports traveling or stationary localizations by looking at ratios of excited neighbors that are essential for generations of the localizations. We conclude by applying biomolecular hypotheses to this model and discuss the significance of our findings in context with cell signaling and emergent behavior in cellular computation.
Attractors for a Nonautonomous Liénard Equation
Authors: Anguiano María
Published: February 2015

In this paper, we prove the existence of pullback and uniform attractors for a nonautonomous Liénard equation. The relation among these attractors is also discussed. After that, we consider that the Liénard equation includes forcing terms which belong to a class of functions extending periodic and almost periodic functions recently introduced by Kloeden and Rodrigues [2011]. Finally, we estimate the Hausdorff dimension of the pullback attractor. We illustrate these results with a numerical simulation: we present a simulation showing the pullback attractor for the nonautonomous Van der Pol equation, an important special case of the nonautonomous Liénard equation.
Reidemeister moves and a polynomial of virtual knot diagrams
Authors: Jeong Myeong-Ju
Published: February 2015

In 2006 C. Hayashi gave a lower bound for the number of Reidemeister moves in deformation of two equivalent knot diagrams by using writhe and cowrithe. It can be naturally extended for two virtually isotopic virtual knot diagrams. We introduce a polynomial qK(t) of a virtual knot diagram K and give lower bounds for the number of Reidemeister moves in deformation of two virtually isotopic knots by using qK(t). We give an example which shows that the polynomial qK(t) is useful to map out a sequence of Reidemeister moves to deform a virtual knot diagram to another virtually isotopic one.
When can an "Expanding Universe" look "Static" and vice versa: A comprehensive study
Authors: Mitra Abhas
Published: February 2015

The Friedmann–Robertson–Walker (FRW) metric expressed, in terms of comoving coordinates (r, t), always looks nonstatic. But by employing the recently derived curvature/Schwarzschild form, (R, T), of FRW metric (A. Mitra, Gravit. Cosmol. 19 (2013) 134), we show here that FRW metric can assume static forms when the net energy density (ρe) is solely due to the vacuum contribution. Earlier this question was explored by Florides (Gen. Relativ. Gravit. 12 (1980) 563) whose approach was complex and of purely mathematical nature. Also, unlike Florides, we do not assume any a priori separability of T(r, t) = F(r)G(t) and thus our treatment is truly general and yet simpler. More interestingly, even if the net energy density involved in a certain FRW model may appear to be nonzero from its algebric appearance, it may still be possible that tacitly ρe = 0 and the model actually corresponds to a vacuum Minkowski metric. For instance, it has been found that FRW universes which appear to be expanding with a fixed speed in comoving coordinates are intrinsically static universes. While such a linearly expanding universe having k = -1 is well-known as the Milne universe, the corresponding k = 0 case has recently been shown to be vacuum in disguise (A. Mitra, Mon. Not. Roy. Astron. Soc. 442 (2014) 382). In addition, here we show that even the k = +1 linearly "expanding" universe (in comoving coordinates) tacitly corresponds to Einstein's static universe.
2014 update of the discoveries of nuclides
Authors: Thoennessen M.
Published: February 2015

The 2014 update of the discovery of nuclide project is presented. Only six new nuclides were observed for the first time in 2014 while the assignments of 17 other nuclides were revised. In addition, for another 14 nuclides the laboratories where they were discovered were reassigned.
FRACTAL ANALYSIS FOR CRYSTAL LAYER STRUCTURE AND IMPURITY DISTRIBUTION RESEARCH OF MELT CRYSTALLIZATION
Authors: LU DA-PENG , LIU YI , HE GAOHONG , JIANG XIAO-BIN
Published: February 2015

Fractal analysis for crystal layer structure formation and impurity distribution of melt crystallization was conducted in this paper. The fractal dimensions were introduced to analyze the structural property of the porous crystal layer and the melt phase migration behavior. The analysis results met the experimental results with a satisfactory agreement. The introduction of fractal theory was contributed to develop novel aspect on the separation effect evaluation on melt crystallization process.
EVALUATION OF FORMATION DAMAGE USING MICROSTRUCTURE FRACTAL IN SHALE RESERVOIRS
Authors: YOU LIJUN , CHEN QIANG , KANG YILI , YU YANGFENG , HE JINGAN
Published: February 2015

Formation damage evaluation is a key and basic link in optimizing working fluids. It is widely accepted that formation damage is the reduction of core plugs permeability caused by working fluid invasion. However, the measurement of permeability faces a huge challenge for shale formation, such as overspending, time-consuming and the scarcity of unbroken core plug samples. A new method of fractal analysis derived from Scanning Electron Microscopy (SEM) image of shale pore structure was used to quantify the shale formation damage. This method needs to select optimal magnification and segmentation threshold value of SEM image to obtain exact Fractal Dimension (FD) of pore structure. In this paper, we take the black shale outcrops from Sichuan Basin for an example. The results shows that the optimal magnification for observation of the pore structure using SEM imaging in this area is 1000×, and the optimal threshold value for binary image is 29 (RGB). Microscopic pore structure of the shale follows the fractal law, and the FDs increase with increasing measurement scales. It is evident that the evaluation results of shale formation damage when exposed to 2 wt.% NaOH solution and 2 wt.% brine solution using microstructure fractal are exceptionally in good agreement with permeability reduction results. The microstructure fractal obtained from SEM images provides a new method for evaluation of shale formation damage. And it can be applied to optimize the screening working fluids used in shale formation in real time under the condition of high temperature and high pressure.
3D Edge Detection Based on Boolean Functions and Local Operators
Authors: da Silva Ricardo Dutra , Minghim Rosane , Pedrini Helio
Published: February 2015

Edge detection is one of the most commonly used operations in image processing and computer vision areas. Edges correspond to the boundaries between regions in an image, which are useful for object segmentation and recognition tasks. This work presents a novel method for 3D edge detection based on Boolean functions and local operators, which is an extension of the 2D edge detector introduced by Vemis et al. [Signal Processing45(2), 161–172 (1995)] The proposed method is composed of two main steps. An adaptive binarization process is initially applied to blocks of the image and the resulting binary map is processed with a set of Boolean functions to identify edge points within the blocks. A global threshold, calculated to estimate image intensity variation, is then used to reduce false edges in the image blocks. The proposed method is compared to other 3D gradient filters: Canny, Monga–Deriche, Zucker–Hummel and Sobel operators. Experimental results demonstrate the effectiveness of the proposed technique when applied to several 3D synthetic and real data sets.
A Survey on Document Image Processing Methods Useful for Assistive Technology for the Blind
Authors: Keefer Robert , Bourbakis Nikolaos
Published: February 2015

This paper offers a review of the state-of-the-art document image processing methods and their classification by identifying new trends for automatic document processing and understanding. Document image processing (DIP) is an important problem related with most of the challenges coming from the image processing field and with applications to digital document summarization, readers for the visually impaired etc. Difficulties in the processing of documents can arise from lighting conditions, page curl, page rotation in 3D, and page layout segmentation. Document image processing is usually performed in the context of higher-level applications that require an undistorted document image such as optical character recognition and document restoration/preservation. Typically, assumptions are made to constrain the processing problem in the context of a particular application. In this survey, we categorize document image processing methods on the basis of the technique, provide detailed descriptions of representative methods in each category, and examine their pros and cons. It important to notice here that the DIP field is broad, thus we try to provide a top–down/horizontal survey rather a bottom up. At the same time, we target the area of document readers for the blind, and use this application to guide us in a top–down survey of DIP. Moreover, we present a comparative survey based on important aspects of a marketable system that is dependent on document image processing techniques.
WEAR PREDICTION OF THE LUMBAR TOTAL DISC REPLACEMENT USING FINITE ELEMENT METHOD
Authors: SHANKAR S. , KESAVAN D.
Published: February 2015

Wear in the total disc replacement (TDR) is a significant clinical concern which reduces the lifetime of prosthesis. It induces the formation of potentially harmful debris and involves the risks of a new surgical operation. The objective of this paper is to estimate the wear using finite element (FE) concepts considering various combination of materials: metal-polymer, ceramic–ceramic and metal–metal bearing couples for lumbar total disc replacement (LTDR). The FE model was subjected to wear testing protocols according to loading profile of International Standards Organization (ISO) 18192 standards up to 10 million cycles. The present study revealed that, Alumina–Alumina (Al2O3–Al2O3) bearing pair is suitable one for the TDR process because of less volumetric wear, hence it could be considered in LTDR designs.
Interface characterization of Cu–Mo coating deposited on Ti–Al alloys by arc spraying
Authors: Bai Shengqiang , Li Fei , Wu Ting , Yin Xianglin , Shi Xun , Chen Lidong
Published: February 2015

Cu – Mo pseudobinary alloys are promising candidates as electrode materials in CoSb 3-based skutterudite thermoelectric (TE) devices for TE power generation. In this study, Cu – Mo coatings were deposited onto Ti – Al substrates by applying a dual-wire electric arc spraying coating technique. The microstructure of the surfaces, cross sections and coating interfaces were analyzed by scanning electron microscopy (SEM) and energy dispersion spectrometry (EDS). Cu – Mo coatings showed a typical banded splat with compact microstructures, and have no coarse pores nor micro-cracks. The thermal shock resistance of the Cu – Mo coating was also investigated to show good combinations with Ti – Al substrates. After 50 thermal shock cycles, there were no cracks observed at the interface. In contrast, the test of the thermal shock resistance of the Cu coating on the Ti – Al substrate was also investigated. Due to a large difference in the thermal expansion coefficients between Cu and Ti – Al alloys, the Cu coating flaked from the Ti – Al substrate completely after 10 thermal shock cycles. The contact resistivity of the Ti – Al / Cu – Mo interface was about 1.6 μΩ⋅cm2 and this value was unchanged after 50 thermal shock cycles, indicating the low electric resistance and high thermal stability of the Cu – Mo / Ti – Al interface.
The Impact of a Central Bank's Bond Market Intervention on Foreign Exchange Rates
Authors: Jarrow Robert , Li Hao
Published: February 2015

This paper provides a framework to analyze the effect of a central bank's bond market intervention on foreign exchange rates. Using this framework, we quantify the impact of the Federal Reserve's 2008–2011 quantitative easing (QE) program on the USD/JPY exchange rate. We find that the Fed's QE accounts for a significant portion of the dollar's depreciation during this period. A central monetary authority can affect exchange rates in two ways, either directly by intervening in foreign exchange markets or indirectly by affecting interest rates. Our analysis emphasizes the importance of the indirect channel when a central bank undertakes large scale asset purchases.
Structural geology and well planning in the Clair Field
Authors: Ogilvie Steven , Barr David , Roylance Paul , Dorling Matthew
Published: February 2015

The Clair Field is a giant oilfield located approximately 70 km west of the Shetland Isles, UK. It was discovered in 1977 and brought on stream some 28 years later. Key to unlocking its economic potential was a series of appraisal wells drilled in the early 1990s that identified fractures as the primary production mechanism. Structural geology contributed in several ways to the detailed planning of the development and appraisal wells. In the sandy (Tertiary) tophole section, outcrop analogues and offset wells were used to establish an appropriate standoff from major faults. This was to mitigate the risk of wellbore instability in what is otherwise a relatively benign sequence to drill. The mid-section, Upper Cretaceous mudstone is prone to wellbore instability, believed to be caused by strength anisotropy with respect to bedding. Here, polygonal faulting may contribute directly to wellbore instability. The associated bed rotation also influences anisotropic failure, which depends in part on the wellbore-to-bedding intersection angle. An example is given of how an understanding of the structural evolution of the overburden section impacts well casing placement. Finally, judgement on the nature of the faulted contact between two fault blocks was required for the pressure prognosis of a planned well.
Nonsynonymous single nucleotide polymorphisms of NHE3 differentially decrease NHE3 transporter activity
Authors: Zhu Xinjun Cindy , Sarker Rafiquel , Horton John R. , Chakraborty Molee , Chen Tian-E , Tse C. Ming , Cha Boyoung , Donowitz Mark
Published: February 2015

Genetic determinants appear to play a role in susceptibility to chronic diarrhea, but the genetic abnormalities involved have only been identified in a few conditions. The Na+/H+ exchanger 3 (NHE3) accounts for a large fraction of physiologic intestinal Na+ absorption. It is highly regulated through effects on its intracellular COOH-terminal regulatory domain. The impact of genetic variation in the NHE3 gene, such as single nucleotide polymorphisms (SNPs), on transporter activity remains unexplored. From a total of 458 SNPs identified in the entire NHE3 gene, we identified three nonsynonymous mutations (R474Q, V567M, and R799C), which were all in the protein's intracellular COOH-terminal domain. Here we evaluated whether these SNPs affect NHE3 activity by expressing them in a mammalian cell line that is null for all plasma membrane NHEs. These variants significantly reduced basal NHE3 transporter activity through a reduction in intrinsic NHE3 function in variant R474Q, abnormal trafficking in variant V567M, or defects in both intrinsic NHE3 function and trafficking in variant R799C. In addition, variants NHE3 R474Q and R799C failed to respond to acute dexamethasone stimulation, suggesting cells with these mutant proteins might be defective in NHE3 function during postprandial stimulation and perhaps under stressful conditions. Finally, variant R474Q was shown to exhibit an aberrant interaction with calcineurin B homologous protein (CHP), an NHE3 regulatory protein required for basal NHE3 activity. Taken together, these results demonstrate decreased transport activity in three SNPs of NHE3 and provide mechanistic insight into how these SNPs impact NHE3 function.
Liver protein profiles in insulin receptor-knockout mice reveal novel molecules involved in the diabetes pathophysiology
Authors: Capuani Barbara , Della-Morte David , Donadel Giulia , Caratelli Sara , Bova Luca , Pastore Donatella , De Canio Michele , D'Aguanno Simona , Coppola Andrea , Pacifici Francesca , Arriga Roberto , Bellia Alfonso , Ferrelli Francesca , Tesauro Manfredi , Federici Massimo , Neri Anna , Bernardini Sergio , Sbraccia Paolo , Di Daniele Nicola , Sconocchia Giuseppe , Orlandi Augusto , Urbani Andrea , Lauro Davide
Published: February 2015

Liver has a principal role in glucose regulation and lipids homeostasis. It is under a complex control by substrates such as hormones, nutrients, and neuronal impulses. Insulin promotes glycogen synthesis, lipogenesis, and lipoprotein synthesis and inhibits gluconeogenesis, glycogenolysis, and VLDL secretion by modifying the expression and enzymatic activity of specific molecules. To understand the pathophysiological mechanisms leading to metabolic liver disease, we analyzed liver protein patterns expressed in a mouse model of diabetes by proteomic approaches. We used insulin receptor-knockout (IR−/−) and heterozygous (IR+/−) mice as a murine model of liver metabolic dysfunction associated with diabetic ketoacidosis and insulin resistance. We evaluated liver fatty acid levels by microscopic examination and protein expression profiles by orthogonal experimental strategies using protein 2-DE MALDI-TOF/TOF and peptic nLC-MS/MS shotgun profiling. Identified proteins were then loaded into Ingenuity Pathways Analysis to find possible molecular networks. Twenty-eight proteins identified by 2-DE analysis and 24 identified by nLC-MS/MS shotgun were differentially expressed among the three genotypes. Bioinformatic analysis revealed a central role of high-mobility group box 1/2 and huntigtin never reported before in association with metabolic and related liver disease. A different modulation of these proteins in both blood and hepatic tissue further suggests their role in these processes. These results provide new insight into pathophysiology of insulin resistance and hepatic steatosis and could be useful in identifying novel biomarkers to predict risk for diabetes and its complications.
Analysis of the liver lipidome reveals insights into the protective effect of exercise on high-fat diet-induced hepatosteatosis in mice
Authors: Jordy Andreas B. , Kraakman Michael J. , Gardner Tim , Estevez Emma , Kammoun Helene L. , Weir Jacqui M. , Kiens Bente , Meikle Peter J. , Febbraio Mark A. , Henstridge Darren C.
Published: February 2015

The accumulation of lipid at ectopic sites, including the skeletal muscle and liver, is a common consequence of obesity and is associated with tissue-specific and whole body insulin resistance. Exercise is well known to improve insulin resistance by mechanisms not completely understood. We performed lipidomic profiling via mass spectrometry in liver and skeletal muscle samples from exercise-trained mice to decipher the lipid changes associated with exercise-induced improvements in whole body glucose metabolism. Obesity and insulin resistance were induced in C57BL/6J mice by high-fat feeding for 4 wk. Mice then underwent an exercise training program (treadmill running) 5 days/wk (Ex) for 4 wk or remained sedentary (Sed). Compared with Sed, Ex displayed improved ( P < 0.01) whole body metabolism as measured via an oral glucose tolerance test. Deleterious lipid species such as diacylglycerol ( P < 0.05) and cholesterol esters ( P < 0.01) that accumulate with high-fat feeding were decreased in the liver of trained mice. Furthermore, the ratio of phosphatidylcholine (PC) to phosphatidylethanolamine (PE) (the PC/PE ratio), which is associated with membrane integrity and linked to hepatic disease progression, was increased by training ( P < 0.05). These findings occurred without corresponding changes in the skeletal muscle lipidome. A concomitant decrease ( P < 0.05) was observed for the fatty acid transporters CD36 and FATP4 in the liver, suggesting that exercise stimulates a coordinated reduction in fatty acid entry into hepatocytes. Given the important role of the liver in the regulation of whole body glucose homeostasis, hepatic lipid regression may be a key component by which exercise can improve metabolism.
CXC chemokine receptor-4 signaling limits hepatocyte proliferation after hepatic ischemia-reperfusion in mice
Authors: Wilson Gregory C. , Freeman Christopher M. , Kuethe Joshua W. , Quillin Ralph C. , Nojima Hiroyuki , Schuster Rebecca , Blanchard John , Edwards Michael J. , Caldwell Charles C. , Lentsch Alex B.
Published: February 2015

The role of stromal cell-derived factor-1 (SDF-1 or CXCL12) and its receptor CXC chemokine receptor-4 (CXCR4) in ischemic liver injury and recovery has not been studied. Some reports suggest that this chemokine may aid in liver regeneration, but others suggest that it may be profibrotic through its activation of hepatic stellate cells. In this study we sought to elucidate the role of SDF-1 and its receptor CXCR4 during liver injury, recovery, and regeneration after ischemia-reperfusion (I/R). A murine model of partial (70%) I/R was used to induce liver injury and study the reparative and regenerative response. CXCR4 was expressed constitutively in the liver, and hepatic levels of SDF-1 peaked 8 h after reperfusion but remained significantly increased for 96 h. Treatment of mice with the CXCR4 antagonist AMD3100 or agonist SDF-1 had no effect on acute liver injury assessed 8 h after I/R. However, treatment with AMD3100 increased hepatocyte proliferation after 72 and 96 h of reperfusion and reduced the amount of liver necrosis. In contrast, treatment with SDF-1 significantly decreased hepatocyte proliferation. These effects appeared to be dependent on the presence of liver injury, as AMD3100 and SDF-1 had no effect on hepatocyte proliferation or liver mass in mice undergoing 70% partial hepatectomy. The data suggest that signaling through CXCR4 is detrimental to liver recovery and regeneration after I/R and that clinical therapy with a CXCR4 antagonist may improve hepatic recovery following acute liver injury.
Activation of PPARδ signaling improves skeletal muscle oxidative metabolism and endurance function in an animal model of ischemic left ventricular dysfunction
Authors: Zizola Cynthia , Kennel Peter J. , Akashi Hirokazu , Ji Ruiping , Castillero Estibaliz , George Isaac , Homma Shunichi , Schulze P. Christian
Published: February 2015

Exercise intolerance in heart failure has been linked to impaired skeletal muscle oxidative capacity. Oxidative metabolism and exercise capacity are regulated by PPARδ signaling. We hypothesized that PPARδ stimulation reverts skeletal muscle oxidative dysfunction. Myocardial infarction (MI) was induced in C57BL/6 mice and the development of ventricular dysfunction was monitored over 8 wk. Mice were randomized to the PPARδ agonist GW501516 (5 mg/kg body wt per day for 4 wk) or placebo 8 wk post-MI. Muscle function was assessed through running tests and grip strength measurements. In muscle, we analyzed muscle fiber cross-sectional area and fiber types, metabolic gene expression, fatty acid (FA) oxidation and ATP content. Signaling pathways were studied in C2C12 myotubes. FA oxidation and ATP levels decreased in muscle from MI mice compared with sham- operated mice. GW501516 administration increased oleic acid oxidation levels in skeletal muscle of the treated MI group compared with placebo treatment. This was accompanied by transcriptional changes including increased CPT1 expression. Further, the PPARδ-agonist improved running endurance compared with placebo. Cell culture experiments revealed protective effects of GW501516 against the cytokine-induced decrease of FA oxidation and changes in metabolic gene expression. Skeletal muscle dysfunction in HF is associated with impaired PPARδ signaling and treatment with the PPARδ agonist GW501516 corrects oxidative capacity and FA metabolism and improves exercise capacity in mice with LV dysfunction. Pharmacological activation of PPARδ signaling could be an attractive therapeutic intervention to counteract the progressive skeletal muscle dysfunction in HF.
CYR61 (CCN1) overexpression induces lung injury in mice
Authors: Grazioli Serge , Gil Sucheol , An Dowon , Kajikawa Osamu , Farnand Alex W. , Hanson Josiah F. , Birkland Timothy , Chen Peter , Duffield Jeremy , Schnapp Lynn M. , Altemeier William A. , Matute-Bello Gustavo
Published: February 2015

Cysteine-rich protein-61 (CYR61), also known as connective tissue growth factor, CYR61, and nephroblastoma overexpressed gene 1 (CCN1), is a heparin-binding protein member of the CCN family of matricellular proteins. Gene expression profiles showed that Cyr61 is upregulated in human acute lung injury (ALI), but its functional role is unclear. We hypothesized that CYR61 contributes to ALI in mice. First, we demonstrated that CYR61 expression increases after bleomycin-induced lung injury. We then used adenovirus-mediated gene transfer to determine whether CYR61 overexpression in the lungs was sufficient to cause ALI. Mice instilled with CYR61 adenovirus showed greater weight loss, increased bronchoalveolar lavage total neutrophil counts, increased protein concentrations, and increased mortality compared with mice instilled with empty-vector adenovirus. Immunohistochemical studies in lungs from humans with idiopathic pulmonary fibrosis revealed CYR61 expression on the luminal membrane of alveolar epithelial cells in areas of injury. We conclude that CYR61 is upregulated in ALI and that CYR61 overexpression exacerbates ALI in mice.
Prolactin anterior pituitary expression and circulating levels are reduced in obese and diabetic rats: role of TGF-β and TNF-α
Authors: Lemini María , Ruiz-Herrera Xarubet , Ledesma-Colunga María G. , Díaz-Lezama Nundehui , De los Ríos Ericka A. , López-Barrera Fernando , Méndez Isabel , Martínez de la Escalera Gonzalo , Macotela Yazmín , Clapp Carmen
Published: February 2015

The levels of the hormone prolactin (PRL) are reduced in the circulation of patients with Type 2 diabetes and in obese children, and lower systemic PRL levels correlate with an increased prevalence of diabetes and a higher risk of metabolic syndrome. The secretion of anterior pituitary (AP) PRL in metabolic diseases may be influenced by the interplay between transforming growth factor β (TGF-β) and tumor necrosis factor α (TNF-α), which inhibit and can stimulate AP PRL synthesis, respectively, and are known contributors to insulin resistance and metabolic complications. Here, we show that TGF-β and TNF-α antagonize the effect of each other on the expression and release of PRL by the GH4C1 lactotrope cell line. The levels of AP mRNA and circulating PRL decrease in high-fat diet-induced obese rats in parallel with increased and reduced AP levels of TGF-β and TNF-α mRNA, respectively. Likewise, AP expression and circulating levels of PRL are reduced in streptozotocin-induced diabetic rats and are associated with higher AP expression and protein levels of TGF-β and TNF-α. The opposing effects of the two cytokines on cultured AP cells, together with their altered expression in the AP of obese and diabetic rats suggest they are linked to the reduced PRL production and secretion characteristics of metabolic diseases.
Ammonia excretion in the Atlantic hagfish (Myxine glutinosa) and responses of an Rhc glycoprotein
Authors: Edwards Susan L. , Arnold Justin , Blair Salvatore D. , Pray Margaret , Bradley Rachel , Erikson Olivia , Walsh Patrick J.
Published: February 2015

Hagfishes, the most ancient of the extant craniates, demonstrate a high tolerance for a number of unfavorable environmental conditions, including elevated ammonia. Proposed mechanisms of ammonia excretion in aquatic organisms include vesicular NH4+transport and release by exocytosis in marine crabs, and passive NH3diffusion, active NH4+transport, and paracellular leakage of NH3or NH4+across the gills of fishes. Recently, an emerging paradigm suggests that Rhesus glycoproteins play a vital role in ammonia transport in both aquatic invertebrates and vertebrates. This study has identified an Rh glycoprotein ortholog from the gills of Atlantic hagfish. The hagfish Rhcg shares a 56–60% amino acid identity to other vertebrate Rhcg cDNAs. Sequence information was used to produce an anti-hagfish Rhcg (hRhcg) antibody. We have used hRhcg to localize protein expression to epithelial cells of the gill and the skin. In addition, we have quantified hRhcg expression following exposure to elevated plasma ammonia levels. Animals exposed to a 3 mmol/kg NH4Cl load resulted in significantly elevated plasma ammonia concentrations compared with controls for up to 4 h postinjection. This correlated with net ammonia excretion rates that were also significantly elevated for up to 4 h postinjection. Rhcg mRNA expression in both the gill and skin was significantly elevated by 15 min and 1 h, respectively, and hRhcg protein expression in gills was significantly elevated at 2, 4, and 8 h postinjection. These results demonstrate a potential role for Rhcg in the excretion of ammonia in the Atlantic hagfish.
The magnitude of the somatosensory cortical activity is related to the mobility and strength impairments seen in children with cerebral palsy
Authors: Kurz Max J. , Heinrichs-Graham Elizabeth , Becker Katherine M. , Wilson Tony W.
Published: February 2015

The noted disruption of thalamocortical connections and abnormalities in tactile sensory function has resulted in a new definition of cerebral palsy (CP) that recognizes the sensorimotor integration process as central to the motor impairments seen in these children. Despite this updated definition, the connection between a child's motor impairments and somatosensory processing remains almost entirely unknown. In this investigation, we explored the relationship between the magnitude of neural activity within the somatosensory cortices, the strength of the ankle plantarflexors, and the gait spatiotemporal kinematics of a group of children with CP and a typically developing matched cohort. Our results revealed that the magnitude of somatosensory cortical activity in children with CP had a strong positive relationship with the ankle strength, step length, and walking speed. These results suggest that stronger activity within the somatosensory cortices in response to foot somatosensations was related to enhanced ankle plantarflexor strength and improved mobility in the children with CP. These results provide further support for the notion that children with CP exhibit, not only musculoskeletal deficits, but also somatosensory deficits that potentially contribute to their overall functional mobility and strength limitations.
Multiscale homogenization of a class of nonlinear equations with applications in lubrication theory and applications
Authors: Almqvist Andreas , Essel Emmanuel Kwame , Fabricius John , Wall Peter
Published: February 2015

We prove a homogenization result for monotone operators by using the method of multiscale convergence. More precisely, we study the asymptotic behavior as ε → 0 of the solutions uε of the nonlinear equation div⁡aε(x, ∇uε) = div⁡bε, where both aε and bε oscillate rapidly on several microscopic scales and aε satisfies certain continuity, monotonicity and boundedness conditions. This kind of problem has applications in hydrodynamic thin film lubrication where the bounding surfaces have roughness on several length scales. The homogenization result is obtained by extending the multiscale convergence method to the setting of Sobolev spaces , where 1 < p < ∞. In particular we give new proofs of some fundamental theorems concerning this convergence that were first obtained by Allaire and Briane for the case p = 2.
Treatment of the Developmental Dysplasia of the Hip with an Abduction Brace in Children up to 6 Months Old
Authors: Wahlen Raphaël , Zambelli Pierre-Yves
Published: February 2015

Introduction. Use of Pavlik harness for the treatment of DDH can be complicated for parents. Any misuse or failure in the adjustments may lead to significant complications. An abduction brace was introduced in our institution, as it was thought to be easier to use.Aim. We assess the results for the treatment of DDH using our abduction brace in children of 0–6 months old and compare these results with data on treatments using the Pavlik harness.Method. Retrospective analysis of patients with DDH from 0 to 6 months old at diagnosis, performed from 2004 to 2009. Outcomes were rates of reduction of the hip and avascular necrosis of the femoral head (AVN). Follow-up was at one year and up to 4 years old.Results. Hip reduction was successful in 28 of 33 patients (85%), with no AVN.Conclusion. Our results in terms of hip reduction rate and AVN rate are similar to those found in literature assessing Pavlik harness use, with a simpler and comfortable treatment procedure.
The THz Spectrum of Density Fluctuations of Water: The Viscoelastic Regime
Authors: Cunsolo Alessandro
Published: February 2015

Relevant advances in the knowledge of the water dynamics at mesoscopic scales are reviewed, while mainly focusing on the contribution provided by high resolution inelastic X-ray scattering (IXS). In particular it is discussed how the use of IXS has improved our understanding of viscoelastic properties of water at THz frequencies. This specifically involves some solid-like features such as the onset of shear wave propagation, a sound velocity surprisingly similar to the one of ice, and an anomalously low sound absorption coefficient. All these properties can be explained by assuming the coupling of THz density fluctuations with a structural relaxation process connected to the breaking and forming of hydrogen bonds (HBs). This review also includes more recent IXS results demonstrating that, upon approaching supercritical conditions, relaxation phenomena in water gradually lose their structural character becoming essentially collisional in character. Furthermore, GHz spectroscopy results on supercooled water, suggesting the occurrence of a structural arrest, are discussed. An overview of the new opportunities offered by next generation IXS spectrometers finally concludes this review.
PGE2-Induced IDO1 Inhibits the Capacity of Fully Mature DCs to Elicit anIn VitroAntileukemic Immune Response
Authors: Trabanelli Sara , Lecciso Mariangela , Salvestrini Valentina , Cavo Michele , Očadlíková Darina , Lemoli Roberto M. , Curti Antonio
Published: February 2015

In the last years, dendritic cells (DC) have been evaluated for antitumor vaccination. Although DC-based vaccines have raised great expectations, their clinical translation has been largely disappointing. For these results, several explanations have been proposed. In particular, the concomitant expression by DCs of tolerogenic pathways, such as the immunosuppressive agent indoleamine 2,3-dioxygenase-1 (IDO1), has been demonstrated. The aim of this study is to evaluate both the stimulatory and the tolerogenic feature of monocyte-derived DCs (Mo-DCs) after maturation with PGE2. In particular, the role of IDO1 expression in PGE2-matured Mo-DCs has been addressed. Here we show that PGE2, which is required for full maturation of DCs, is one mediator of DC tolerance by enhancing IDO1. PGE2-mediated expression of IDO1 results in the production of kynurenine, in the generation of Tregs, and in the inhibition of either the allogeneic or the autologous antigen-specific stimulatory capacity of DCs. When pulsed with leukemic lysates and matured with PGE2, DCs are impaired in the induction of IFN-γsecreting CD4+and CD8+T cells due to IDO1 upregulation. Moreover, the inhibition of IDO1 enhances the antileukemic response. Overall, these results point toward the use of IDO1 inhibitors to enhance the vaccination capacity of DCs, matured with PGE2.
Aeroelastic Dynamic Response and Control of an Aeroelastic System with Hysteresis Nonlinearities
Authors: Xu Xingzhi , Gao Yakui , Zhang Weiguo
Published: February 2015

A state feedback control law based on the sliding mode control method is derived for the aeroelastic response and flutter suppression of a two-dimensional airfoil section with hysteresis nonlinearity in pitch. An observer is constructed to estimate the unavailable state variables of the system. With the control law designed, nonlinear effect of time delay between the control input and actuator is investigated by a numerical approach. The closed-loop system including the observer and nonlinear controller is asymptotically stable. The simulation results show that the observer can give precise estimations for the plunge displacement and the velocities in pitch and plunge and that the controller is effective for flutter suppression. The time delay between the control input and actuator may jeopardize the control performance and cause high-frequency vibrations.
Dual Arm Free Flying Space Robot Trajectory Planning Using Polynomial
Authors: Rathee Rishikesh , Pathak Pushparaj Mani
Published: February 2015

The paper presents path planning of dual arm free flying space robot using smooth functions of time. Kinematic and dynamic modeling of dual arm free flying space robot is presented first. Using kinematic model, the Jacobian of the system has been derived, and using dynamic model, equations of motion are derived. A path planning methodology for planar system is developed using smooth function of time such as polynomials. Due to nonholonomic behaviour of the manipulator in the zero gravity environment linear and angular momentum is conserved. The proposed method yields input trajectories that drive both the manipulator and the base to a desired configuration. Joint torque curves can be obtained by introducing this joint trajectory curves in equation of motion of the space robot.
Epidemiological Survey on Porcine Cysticercosis in Nay Pyi Taw Area, Myanmar
Authors: Khaing Tin Aye , Bawm Saw , Wai Soe Soe , Htut Ye , Htun Lat Lat
Published: February 2015

Cross-sectional surveys were conducted to determine the prevalence and associated risk factors of Taenia solium cysticercosis in pigs within Nay Pyi Taw area, Myanmar. Meat inspection in three slaughterhouses, ELISA test, and questionnaire surveys were conducted in this study. Three hundred pigs were inspected in slaughterhouses and 364 pigs were randomly selected and examined from 203 households from three townships in Nay Pyi Taw area. The prevalence of porcine cysticercosis in meat inspection was 23.67% (71/300). Seroprevalence of T. solium cysticercosis in pigs in the study area was 15.93% (58/364). Significant associated risk factors with T. solium cysticercosis were gender (OR=3.0; 95% CI=1.7–5.4), increased age (OR=2.3; 95% CI=1.2–4.2), husbandry system (OR=5.1; 95% CI=2.4–11.2), feed type (OR=16.9; 95% CI=2.3–124.3), not using anthelmintics in pigs (OR=11.9; 95% CI=5.0–28.5), not using anthelmintics in owner (OR=2.5; 95% CI=1.4–4.4), no hand-washing before feeding (OR=31.5; 95% CI=4.3–230.9), and pork consumption of owner (OR=37.4; 95% CI=9.0–156.1) in the study area. This is the first report of porcine cysticercosis in Myanmar.
Secretion of One Adipokine Nampt/Visfatin Suppresses the Inflammatory Stress‐Induced NF‐κB Activity and Affects Nampt‐Dependent Cell Viability in Huh‐7 Cells
Authors: Lin Yi-Ching , Wu Hui-Chung , Liao Chen-Chung , Chou Yi-Chih , Pan Shwu-Fen , Chiu Chi-Ming
Published: February 2015

Nampt/visfatin acts in both intracellular and extracellular compartments to regulate multiple biological roles, including NAD metabolism, cancer, inflammation, and senescence. However, its function in chronic inflammation and carcinogenesis in hepatocellular carcinoma (HCC) has not been well‐defined. Here we use Huh‐7 hepatoma cells as a model to determine how Nampt/visfatin affects cellular survival under oxidative stress. We found that the transition of Nampt/visfatin from intracellular into extracellular form was induced by H2O2 treatment in 293T cells and confirmed that this phenomenon was not due to cell death but through the secretion of Nampt/visfatin. In addition, Nampt/visfatin suppressed cell viability in oxidative treatment in Huh‐7 cells and acted on the inhibition of hepatoma cell growth. Oxidative stress also reduced the Nampt‐mediated activation of NF‐κB gene expression. In this study, we identify a novel feature of Nampt/visfatin which functions as an adipokine that can be secreted upon cellular stress. Our results provide an example to understand how adipokine interacts with chemotherapeutic treatment by oxidative stress in HCC.
Contiki-Based IEEE 802.15.4 Channel Capacity Estimation and Suitability of Its CSMA-CA MAC Layer Protocol for Real-Time Multimedia Applications
Authors: Farooq Muhammad Omer , Kunz Thomas
Published: February 2015

Real-time multimedia applications require quality of service (QoS) provisioning in terms of bounds on delay and packet loss along with soft bandwidth guarantees. The shared nature of the wireless communication medium results in interference. Interference combined with the overheads, associated with a medium access control (MAC) protocol, and the implementation of a networking protocol stack limit the available bandwidth in IEEE 802.15.4-based networks and can result in congestion, even if the transmission rates of nodes are well below the maximum bandwidth supported by an underlying communication technology. Congestion degrades the performance of admitted real-time multimedia flow(s). Therefore, in this paper, we experimentally derive the IEEE 802.15.4 channel capacity using an unslotted CSMA-CA MAC protocol. We experimentally derive channel capacity for two cases, that is, when the CSMA-CA protocol is working without ACKs and when it is working with ACKs. Moreover, for both cases, we plot the relationship of offered data load with delay and packet loss rate. Simulation results demonstrate that the parameters that affect the choice of a CSMA-CA MAC layer protocol are end-to-end delay and packet loss requirements of a real-time multimedia flow, data load within the interference range of transmitters along the forwarding path, and length of the forwarding path.
Thoracocervicofacial Emphysema after Heimlich’s Maneuvre
Authors: Bouayed Salim , Sandu Kishore , Teiga Pedro S. , Hallak Bassel
Published: February 2015

We report an extremely rare example of a thoracocervicofacial subcutaneous emphysema after Heimlich maneuver case.
Anesthesia Management of a 20-Month-Old Patient with Giant Unilateral Wilms Tumor
Authors: Matinyan Nune , Saltanov Alexander , Martynov Leonid , Kazantsev Anatolij
Published: February 2015

Wilms tumour (WT) (or nephroblastoma) is one of the most common malignant kidney tumors in children. On subsequent stages clinically it is often characterized by abdominal hypertension syndrome, which, in turn, leads to development of respiratory insufficiency. Other symptoms comprise renal deficiency, hypertension, and abnormalities of hemostasis and hemogram. Treatment includes rounds of preoperative chemotherapy and subsequent surgery. We report a case of perioperative management for nephrectomy in 20-month-old patient with a giant unilateral WT. The complexity of anesthesia was determined by the size of tumor, increased intra-abdominal pressure, respiratory deficiency, and hypercoagulation.
Effect of Organic Inhibitors on Chloride Corrosion of Steel Rebars in Alkaline Pore Solution
Authors: Cabrini Marina , Fontana Francesca , Lorenzi Sergio , Pastore Tommaso , Pellegrini Simone
Published: February 2015

The inhibition properties of aspartic and lactic acid salts are compared with nitrite ions with regard to their effect on critical chloride concentration. The tests were carried out on carbon steel specimens in simulated pore solutions with initial pH in the range of 12.6 to 13.8. The critical chloride concentrations were estimated through multiple specimen potentiostatic tests at potentials in the usual range for passive rebar in noncarbonated concrete structures. During tests, chloride ions were progressively added until all specimens showed localized attack, obtaining cumulative distribution curves reporting the fraction of corroded specimens as a function of chloride concentration. The presence of the organic inhibitors on the passivity film was detected by IR spectra. The results confirm that 0.1 M aspartate exhibits an inhibiting effect comparable with nitrite ions of the same concentration. Calcium lactate does not increase critical chloride concentration; however it appears to promote the formation of a massive scale, reducing the corrosion propagation.
Weak Minimal Area in Entanglement Entropy
Authors: Pal Shesansu Sekhar , Rath Shubhalaxmi
Published: February 2015

We revisit the minimal area condition of Ryu-Takayanagi in the holographic calculation of the entanglement entropy, in particular, the Legendre test and the Jacobi test. The necessary condition for the weak minimality is checked via Legendre test and its sufficient nature via Jacobi test. We show for AdS black hole with a strip type entangling region that it is this minimality condition that makes the hypersurface unable to cross the horizon, which is in agreement with that studied earlier by Engelhardt et al. and Hubeny using a different approach. Moreover, demanding the weak minimality condition on the entanglement entropy functional with the higher derivative term puts a constraint on the Gauss-Bonnet coupling; that is, there should be an upper bound on the value of the coupling,λa<(d-3)/4(d-1).