bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving the term structure of interest rates: two‐factor models
Authors: Gómez‐Valle Lourdes , Martínez‐Rodríguez Julia 
Published: April 2009

AbstractWe consider a new approach for estimating the coefficients of the term structure equation in two‐factor models. This approach is based on the fact that the risk‐neutral drifts of the factors are directly estimated. Therefore, the market prices of risk and the physical drifts do not have to be either identified or estimated.In order to study the finite properties of this approach, we generate trajectories in a stochastic volatility model. We find that the risk‐neutral drifts and the yield curves are more accurately estimated. Finally, we show the supremacy of this approach by means of US Treasury Bill data. Copyright © 2009 John Wiley & Sons, Ltd.
Costs associated with mutual funds in Spain
Authors: Toledo Isabel , Marco Rocío 
Published: April 2009

AbstractThis study examines the mutual fund market in Spain from the point of view of management and custodial costs. For this purpose it estimates functions explaining these fees using ordinary least squares and panel data. The results confirm that the most relevant factors in determining the management fee are the risk incurred by the managed portfolio, the level of its cash holding, and the number of shareholders in relation to the size of the fund. In addition, it highlights two aspects of the Spanish market with respect to the results obtained by similar studies in the North American market and in some European countries (Finland, Italy): first, the lack of a learning curve reducing operational costs, and, second, the lack of economies of scale in the management costs. Copyright © 2009 John Wiley & Sons, Ltd.
Probing for local activity‐related modulation of the infrared backscattering of the brain cortex
Authors: Biella Gabriele E. M. , Trevisan Stefano , Giardini Mario E. 
Published: April 2009

AbstractThe possibility to measure the metabolic activity of the brain cortex, with submillimeter spatial and subsecond temporal resolution, would open up enticing scenarios in addressing basic issues on the relation between different structural components of brain signal processing, and in providing an operational pathway to interaction with (dis)functional signal patterns. In the present article, we report the description of a simple system that allows the detection of the minute changes that occur in the optical backscattering of the cortex as a metabolic response to external stimuli. The simplicity of the system is compatible with scalability to an implantable probe. We validate the system on an animal model, and we propose an algorithm to extract meaningful data from the measured signal. We thus show the detection of individual haemodynamic cortical responses to individual stimulation events, and we provide operational considerations on the signal structure. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hematological responses of the grey carpet shark (Chiloscyllium punctatum) and the epaulette shark (Hemiscyllium ocellatum) to anoxia and re‐oxygenation
Authors: Chapman Clint A. , Renshaw Gillian M.C. 
Published: April 2009

AbstractWe compared the hematological responses of wild and captive populations of two closely related sharks to a standardized anoxic challenge and during a 12 hr recovery period in normoxia: the epaulette shark (Hemiscyllium ocellatum, Bonnaterre, 1788) and the grey carpet shark (Chiloscyllium punctatum, Müller and Henle, 1838). Compared to normoxic controls, a significant increase in hematocrit (captive 22.3%; wild 35.9%) coupled with a decline in mean corpuscular hemoglobin concentration occurred in epaulette sharks indicating erythrocyte swelling in response to anoxia. However, the grey carpet shark had a significantly increased hematocrit (captive 27.2%; wild 29.3%), erythrocyte count (captive 37.6%; wild 46.3%) and hemoglobin concentration (captive 31.9%; wild 31.5%), suggesting a release of erythrocytes into the circulation and/or hemoconcentration in response to anoxia. Plasma glucose concentrations were maintained in both wild and captive epaulette sharks and in wild grey carpet sharks during anoxia but increased significantly after 2 hr of re‐oxygenation (epaulette: captive 55.8%; wild 50.1%; grey carpet shark: wild 70.3%) and remained elevated for 12 hr. Captive grey carpet sharks had an immediate increase in plasma glucose concentrations after anoxia (96.4%), which was sustained for 12 hr of re‐oxygenation. Lactate concentrations significantly increased in captive and wild animals of both species after anoxia, reaching a peak at 2 hr of re‐oxygenation. Both species showed significant, yet divergent, hematological changes in response to anoxia and re‐oxygenation, which may not only prolong their survival and assist in recovery but also reflect their respective ecophysiological adaptations to the extreme environments that they inhabit. J. Exp. Zool. 311A:422–438, 2009. © 2009 Wiley‐Liss, Inc.
ZOONET: perspectives on the evolution of animal form. Meeting report
Authors: Fischer Antje H. L. , Arboleda Enrique , Egger Bernhard , Hilbrant Maarten , McGregor Alistair P. , Cole Alison G. , Daley Allison C. 
Published: April 2009

AbstractWhat drives evolution? This was one of the main questions raised at the final ZOONET meeting in Budapest, Hungary, in November 2008. The meeting marked the conclusion of ZOONET, an EU‐funded Marie‐Curie Research Training Network comprising nine research groups from all over Europe (Max Telford, University College London; Michael Akam, University of Cambridge; Detlev Arendt, EMBL Heidelberg; Maria Ina Arnone, Stazione Zoologica Anton Dohrn Napoli; Michalis Averof, IMBB Heraklion; Graham Budd, Uppsala University; Richard Copley, University of Oxford; Wim Damen, University of Cologne; Ernst Wimmer, University of Göttingen). ZOONET meetings and practical courses held during the past four years provided researchers from diverse backgrounds—bioinformatics, phylogenetics, embryology, palaeontology, and developmental and molecular biology—the opportunity to discuss their work under a common umbrella of evolutionary developmental biology (Evo Devo). The Budapest meeting emphasized in‐depth discussions of the key concepts defining Evo Devo, and bringing together ZOONET researchers with external speakers who were invited to present their views on the evolution of animal form. The discussion sessions addressed four main topics: the driving forces of evolution, segmentation, fossils and phylogeny, and the future of Evo Devo. J. Exp. Zool. (Mol. Dev. Evol.) 312B:679–685, 2009. © 2009 Wiley‐Liss, Inc.
Cycle‐minors and subdivisions of wheels
Authors: Turner Galen E. 
Published: April 2009

AbstractIn this paper we prove two results. The first is an extension of a result of Dirac which says that any set of n vertices of an n‐connected graph lies in a cycle. We prove that if V′ is a set of at most 2n vertices in an n‐connected graph G, then G has, as a minor, a cycle using all of the vertices of V′. The second result says that if G is an n+1‐connected graph with maximum vertex degree Δ then G contains a subgraph that is a subdivision of W2n if and only if Δ≥2n. © 2009 Wiley Periodicals, Inc. J Graph Theory 62: 100–108, 2009
Constructing isospectral non‐isomorphic digraphs from hypergraphs
Authors: Balof Barry , Storm Christopher 
Published: April 2009

AbstractWe explore the “oriented line graph” construction associated with a hypergraph, leading to a construction of pairs of strongly connected directed graphs whose adjacency operators have the same spectra. We give conditions on a hypergraph so that a hypergraph and its dual give rise to isospectral, but non‐isomorphic, directed graphs. The proof of isospectrality comes from an argument centered around hypergraph zeta functions as defined by Storm. To prove non‐isomorphism, we establish a Whitney‐type result by showing that the oriented line graphs are isomorphic if and only if the hypergraphs are. © 2009 Wiley Periodicals, Inc. J Graph Theory 63: 231–242, 2010
Pyrimidines. XV. (Amino Acids. II.) DL‐β‐(dihydroxypyrimidinyl) alanines
Authors: Springer Roberr H. , Haggerty William J. , Cheng C. C. 
Published: April 2009

AbstractThe Prepration of two uracil derivatives of alanine, DL‐β‐(5‐uracilyl)alanine and DL‐β(6‐uracilyl)alanine, are reported. A structural analog, dl‐4,6‐dihydroxy‐β‐(2‐(pyrimidinyl)alanine, which was reported to be labile to acid hydrolysis, has now been successfully prepared in our laboratories.The relationship between the relative position of an alanine moity on some nitrogen hetrocyclic ring systems and their color formation with ninhydrin are discussed.
Mitochondrial inhibitor 3‐nitroproprionic acid enhances oxidative modification of alpha‐synuclein in a transgenic mouse model of multiple system atrophy
Authors: Ubhi Kiren , Lee Phil Hyu , Adame Anthony , Inglis Chandra , Mante Michael , Rockenstein Edward , Stefanova Nadia , Wenning Gregor K. , Masliah Eliezer 
Published: April 2009

AbstractMultiple system atrophy (MSA) is a progressive neurodegenerative disease characterized by autonomic failure, parkinsonism, cerebellar ataxia, and oligodendrocytic accumulation of alpha‐synuclein (αsyn). Oxidative stress has been linked to neuronal death in MSA and the mitochondrial toxin 3‐nitropropionic acid (3NP) is known to enhance the motor deficits and neurodegeneration in transgenic mice models of MSA. However, the effect of 3NP administration on αsyn itself has not been studied. In this context, we examined the neuropathological effects of 3NP administration in αsyn transgenic mice expressing human αsyn (hαsyn) under the control of the myelin basic protein (MBP) promoter and the effect of this administration on posttranslational modifications of αsyn, on levels of total αsyn, and on its solubility. We demonstrate that 3NP administration altered levels of nitrated and oxidized αsyn in the MBP‐hαsyn tg while not affecting global levels of phosphorylated or total αsyn. 3NP administration also exaggerated neurological deficits in the MBP‐hαsyn tg mice, resulting in widespread neuronal degeneration and behavioral impairment. © 2009 Wiley‐Liss, Inc.
Stereological investigation of age‐related changes of myelinated fibers in the rat cortex
Authors: Zhang Wei , Yang Shu , Li Chen , Chen Lin , Tang Yong 
Published: April 2009

AbstractIn the present study, the cortex volume, total volume, total length and mean diameter of the myelinated fibers in the cortices of young, middle‐aged, and aged Long‐Evans rats were quantitatively investigated by using stereological methods and electron microscopy techniques. There were no significant differences in the myelinated fibers between young and middle‐aged rat cortex. The cortex volume and the total length of the myelinated fibers in the cortex of aged rats were significantly lower than those of young and middle‐aged rats. However, no significant difference was found in the total volume of the myelinated fibers among three groups. The disproportional changes in the total length and total volume of the myelinated fibers in the cortex of aged rats and the absolute distribution of the total length of the myelinated fibers in the cortex of the three groups suggested that the age‐induced decrease of the myelinated fibers might be due mainly to a loss of the myelinated fibers with smaller diameters. The present results together with our previous findings indicated that the age‐related changes of the myelinated fibers occurred widely in the central nervous system and that the age‐related changes of the myelinated fibers in cortex occurred later than those in white matter. © 2009 Wiley‐Liss, Inc.
Acetylcholine synthesis and release in NIH3T3 cells coexpressing the high‐affinity choline transporter and choline acetyltransferase
Authors: Fujii Takeshi , Masai Manabu , Misawa Hidemi , Okuda Takashi , Takada‐Takatori Yuki , Moriwaki Yasuhiro , Haga Tatsuya , Kawashima Koichiro 
Published: April 2009

AbstractAcetylcholine (ACh) is known to be a key neurotransmitter in the central and peripheral nervous systems, but it is also produced in a variety of non‐neuronal tissues and cells, including lymphocytes, placenta, amniotic membrane, vascular endothelial cells, keratinocytes, and epithelial cells in the digestive and respiratory tracts. To investigate contribution made by the high‐affinity choline transporter (CHT1) to ACh synthesis in both cholinergic neurons and nonneuronal cells, we transfected rat CHT1 cDNA into NIH3T3ChAT cells, a mouse fibroblast line expressing mouse choline acetyltransferase (ChAT), to establish the NIH3T3ChAT 112‐1 cell line, which stably expresses both CHT1 and ChAT. NIH3T3ChAT 112‐1 cells showed increased binding of the CHT1 inhibitor [3H]hemicholinium‐3 (HC‐3) and greater [3H]choline uptake and ACh synthesis than NIH3T3ChAT 103‐1 cells, a CHT1‐negative control cell line. HC‐3 significantly inhibited ACh synthesis in NIH3T3ChAT 112‐1 cells but did not affect synthesis in NIH3T3ChAT 103‐1 cells. ACh synthesis in NIH3T3ChAT 112‐1 cells was also reduced by amiloride, an inhibitor of organic cation transporters (OCTs) involved in low‐affinity choline uptake, and by procaine and lidocaine, two local anesthetics that inhibit plasma membrane phospholipid metabolism. These results suggest that CHT1 plays a key role in ACh synthesis in NIH3T3ChAT 112‐1 cells and that choline taken up by OCTs or derived from the plasma membrane is also utilized for ACh synthesis in both cholinergic neurons and nonneuronal cholinergic cells, such as lymphocytes. © 2009 Wiley‐Liss, Inc.
Intraneuronal signaling pathways of metallothionein
Authors: Asmussen Johanne Wirenfeldt , Von Sperling Marie Louise , Penkowa Milena 
Published: April 2009

AbstractMetallothionein (MT) belongs to a family of metal‐binding cysteine‐rich proteins comprising several structurally related proteins implicated in tissue protection and regeneration after injuries and functioning as antiapoptotic antioxidants in neurological disorders. This has been demonstrated in animals receiving MT treatment and in mice with endogenous MT overexpression or null mutation during various experimental models of neuropathology, and also in patients with Alzheimer's disease and amyotrophic lateral sclerosis. Exogenously applied MT increases neurite outgrowth and neuronal survival in rat cerebellar, hippocampal, dopaminergic, and cortical neurons in vitro. In this study, the intraneuronal signaling involved in MT‐mediated neuritogenesis was examined. The MT‐induced neurite outgrowth in cultures of cerebellar granule neurons was dependent on activation of a heterotrimeric G‐protein‐coupled pathway but not on protein tyrosine kinases or on receptor tyrosine kinases. Activation of phospholipase C was necessary for MT‐induced neurite outgrowth, and furthermore it was shown that inhibition of several intracellular protein kinases, such as protein kinase A, protein kinase C, phosphatidylinositol 3‐kinase, Ca2+/calmodulin kinase‐II, and mitogen‐activated protein kinase kinase, abrogated the MT‐mediated neuritogenic response. In addition, exogenously applied MT resulted in a decrease in phosphorylation of intraneuronal kinases implicated in proinflammatory reactions and apoptotic cell death, such as glycogen synthase‐serine kinase 3α, Jun, and signal transducer and activator of transcription 3. This paper elucidates the intraneuronal molecular signaling involved in neuroprotective effects of MT. © 2009 Wiley‐Liss, Inc.
Mice lacking adenylyl cyclase‐5 cope badly with repeated restraint stress
Authors: Kim Kyoung‐Shim , Han Pyung‐Lim 
Published: April 2009

AbstractPhysiological responses to acute stress proceed with the activation of the hypothalamus‐pituitary‐adrenal gland (HPA) system. Many brain regions are known to modulate the HPA axis activation in stress responses, but the detailed neural circuits and signaling system in the upstream of the HPA axis have to be explored further. Type 5 adenylyl cyclase (AC5) is highly concentrated in the dorsal striatum and nucleus accumbens, which are implicated in reward and stress‐related behavior.AC5–/–mice exposed to daily 2‐hr restraint stress for only 3–5 days showed poor stress‐coping responses, including severe body weight loss, poor coat condition, respiratory difficulties, and freezing behavior. Plasma corticosterone levels during 2‐hr stress sessions increased inAC5–/–mice compared with those ofAC5+/+mice. However, neither the corticosterone receptor antagonist RU486 nor the CRH receptor antagonist NBI27914 blocked their poor stress coping, whereas the administration of the GABAAreceptor allosteric modulator diazepam or the D1 dopamine receptor antagonist SCH23390 prior to restraint stress sessions changed their stress‐coping response to the stressedAC5+/+mouse level. Stress‐triggered c‐Fos expression was completely blunted in the dorsal striatum ofAC5–/–. These results suggest that the AC5‐associated signal system and neural network are involved in the regulation of anxiety and stress‐coping response. © 2009 Wiley‐Liss, Inc.
Novel three‐dimensional MRI technique for study of cartilaginous hip surfaces in Legg‐Calvé‐Perthes disease
Authors: Pienkowski David , Resig JoAnne , Talwalkar Vishwas , Tylkowski Chester 
Published: April 2009

AbstractTreatment of Legg‐Calvé‐Perthes disease (LCPD) may improve if new knowledge can be obtained regarding how articular cartilage changes shape during the course of this disorder. A new technique is presented showing how analyses of magnetic resonance images can be used to quantify the three‐dimensional changes in the femoral and acetabular articulating cartilage surfaces of children with LCPD. Ten male subjects (8 ± 1 years) with unilateral LCPD were enrolled in this IRB approved study. Sets of magnetic resonance images of both hips were obtained at three different times. Three‐dimensional virtual models of the cartilage were created from these images, and mathematical spheres were fit to the articulating surfaces. Five parameters (size, shape deformity (sphericity error), radial growth rate, joint fit, and joint incongruity) were used to quantify cartilage surface shape. Data were analyzed by using a linear mixed‐model. Joint incongruity, i.e., the distance between the centers of the femoral and acetabular spheres, was slightly more than 2.5 times larger (p = 0.001) in LCPD hips than the contralateral normal hips. Cartilage shape deformity was 65% larger in hips with LCPD than in normal hips. Growth rates of the femoral head and the opposing acetabular surface showed that distortion of the femoral surface occurred first and the opposing acetabular surface followed. Mean radial difference (acetabular surface radius minus femoral surface radius) in LCPD hips was less than half (p < 0.01) the value of normal hips. Interobserver variability was ∼10% of the value attributable to LCPD. This is the first known report presenting a technique that quantifies the three‐dimensional size, deformity, growth, fit. and incongruity of the femoral and acetabular articulating cartilaginous surfaces of LCPD and contralateral normal hips. The data obtained support the use of this technique and provide pilot data for a future clinical study of LCPD. Objective assessment of cartilage shape enabled by this technique may aid future diagnoses, enable monitoring of three‐dimensional femoral and acetabular remodeling, and permit quantitative assessment of treatment efficacy. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 981–988, 2009
Effect of supplementary manganese on the sporulation of Bacillus endospores analysed by Raman spectroscopy
Authors: Stöckel S. , Meisel S. , Böhme R. , Elschner M. , Rösch P. , Popp J. 
Published: April 2009

AbstractIt is a common practice in microbiology to induce and accelerate sporulation of spore‐forming bacteria by adding small amounts of divalent manganese to the cultivation medium. By micro‐Raman spectroscopy the effect of supplementary divalent manganese during the growth and sporulation of Bacillus spp. bacteria was studied. The spectral alterations in the Raman spectra of single endospores due to this cultivation parameter comprised slight alterations of the bands attributed to intracellular, abundantly present calcium dipicolinate (CaDPA). Those signals suffered a loss of intensity or partial band broadening because of the appearance of new weak signals next to them. Exclusively in Raman spectra of single B. sphaericuss endospores, the band at 1485 cm−1 vanished. The theoretical spectra of CaDPA and manganese dipicolinate (MnDPA) were calculated and compared with the experimental spectra to prove the hypothesis that, while the overall intracellular DPA content decreased, an intracellular assembly of MnDPA in the endospores might also occur. Band shifts of the COO− vibrations in the salt's spectra as well as in the endospore's spectra, and the decrease of the two CaDPA bands, confirmed this proposal. The appearance of the 1030 cm−1 band in all Bacillus spectra as well as the disappearance of the 1485 cm−1 band in the B. sphaericus spectra still needs to be clarified. With the help of two multivariate chemometric methods, these spectral alterations allowed discrimination between single endospores of different Bacillus strains cultivated on normal nutrient agar (NA) and those grown on NA with MnSO4 · xH2O addition. With these investigations, a possible strategy is shown to trace back the cultivation environment of matured single endospores. Utilizing the joint concept of micro‐Raman spectroscopy and chemometric analysis, the differentiation between natively grown endospores and those cultivated in a laboratory with the help of manganous salts as a common sporulation accelerator seems accomplishable. Copyright © 2009 John Wiley & Sons, Ltd.
Monitoring the synthesis of new polymer nanocomposites based on different polyhedral oligomeric silsesquioxanes using Raman spectroscopy
Authors: Sulca Nicoleta Mihaela , Lungu Adriana , Garea Sorina Alexandra , Iovu Horia 
Published: April 2009

AbstractThe kinetic behavior of the urethane dimethacrylate (UDMA) copolymerized and reinforced by different concentrations of polyhedral oligomeric silsesquioxane (POSS) with methacrylic groups was studied through Raman spectroscopy. UDMA‐POSS networks have been synthesized with three different types of POSS, two monofunctional POSS (1‐propylmethacrylate)‐heptaisobutyl substituted (HISO‐POSS) and heptacyclopentyl‐octasiloxan‐1‐yloxy) dimethylsilyl] propyl methacrylate (CPENTYL‐POSS) and one octafunctional POSS‐methacryl substituted (MA‐POSS). In order to show the influence of POSS on the final conversion, the hybrid systems were cured using three types of initiators which decompose at different temperatures: azobisisobutyronitrile (AIBN) (65 °C), benzoyl peroxide (BP) (80 °C) and di‐tert‐butyl peroxide (DTBP) (120 °C). The structure of the hybrid's surface was investigated by X‐ray photoelectron spectroscopy (XPS) and the Tg values were calculated from dynamic mechanical analysis (DMA) tests. Copyright © 2009 John Wiley & Sons, Ltd.