bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of economics in irrigation water management
Authors: Hellegers Petra J. G. J. 
Published: March 2006

AbstractEconomic literature and international conferences have extensively discussed the importance of treating irrigation water as an economic good, but there is still confusion about the role of economics in irrigation water management. Economics provides us with two contributions: analytical tools that help predict and interpret implications of various allocation procedures, and economic instruments that can assist in guiding users towards socially desirable outcomes. In this article the potential role of both contributions to improved irrigation water management is discussed, which is an extension of conventional work in this field. It becomes clear that, at this point in time, there is little empirical evidence of the effectiveness of economic instruments in irrigation water management. Economics mainly plays a role in understanding the implications of different procedures for allocating water, and guiding policymakers in defining appropriate allocation rules. Copyright © 2006 John Wiley & Sons, Ltd.
Functional characterization of human mesenchymal stem cells that maintain osteochondral fates
Authors: Romero‐Prado Marina , Blázquez Cristina , Rodríguez‐Navas Carmen , Muñoz Jaime , Guerrero Isabel , Delgado‐Baeza Emilio , García‐Ruiz Josefa P. 
Published: March 2006

AbstractAdult stem cells are essential for tissue renewal, regeneration and repair, and their expansion in defined culture medium is on focus for regenerative medicine and genetic pathologies. The bone marrow has been shown to be very rich is pluripotent mesenchymal stem cells (MSCs) capable of forming bone, cartilage and also may give rise, to neurons and astrocytes in vivo and in vitro. MSCs can be isolated and expanded in culture, but human cells cannot be verified for a cartilage or a bone fate by transfer experiments. Accordingly, here we used different approaches to characterize hMSCs osteoblastic differentiation in vitro. hMSCs grown in culture in the presence of fetal bovine serum (FBS) expressed the bone‐specific transcription factor Runx2/AML3. When cells were incubated in osteoblastic differentiation medium, cells expressed transcripts belonging to the signaling of Indian HH‐PTHrP axis, GLI transcription factors, and bone target genes including osteopontin. The HH pathway proved to be functional since it induced cells to grow. Cells growing or differentiating to osteoblasts presented the Runx2/AML3 transcription factor, its partner CBFB, and Smad2/3 at the nuclei associated with the nuclear matrix. Furthermore, Runx2/AML3 was observed to co‐localize with SC35 to the nuclear intermediary filaments. These data support the notion that hMSCs isolated from human bone are or become bone progenitor cells upon culture. In the absence of FBS and in the presence of insulin or prolactin, cells show cytoskeletal organization and an AP‐1 transcription site activity resembling proliferative osteochondrocytes while cells in the presence of dexamethasone and added prolactin or TGF‐β resembled differentiated osteoblasts. These specific cellular conditions match those observed during endochondral bone formation. J. Cell. Biochem. © 2005 Wiley‐Liss, Inc.
RETRACTED: Increased expression of LGI1 gene triggers growth inhibition and apoptosis of neuroblastoma cells
Authors: Gabellini Nadia. , Masola V. , Quartesan S. , Oselladore B. , Nobile C. , Michelucci R. , Curtarello M. , Parolin C. , Palù G. 
Published: March 2006

AbstractThe LGI1 gene has been implicated in the malignant progression of glioblastoma and it has also been genetically linked to a form of partial epilepsy (ADLTE). In this study, we investigated the relevance of LGI1 expression for neuroblastoma cells. The analysis of two cell lines (SH‐SY5Y and SK‐N‐BE) revealed unpredictably low levels of LGI1 and stable cell transfection with LGI1 cDNA yielded moderate increases of LGI1 expression. Neuroblastoma cell clones exhibited impaired cell growth and survival ability in relation to LGI1 levels. The process of growth inhibition could be discerned under experimental conditions of low cell density, since conditions of elevated cell density, which enhance the requirement for survival stimuli, resulted in massive cellular death. At high cell density, spontaneous apoptosis of LGI1 cells was clearly shown by the release of cytochrome c and apoptosis inducing factor (AIF) from mitochondria and by phosphatydil serine exposure and nuclear fragmentation. Activation of apoptotic effectors caspase‐3/7 also occurred, however, the broad caspase inhibitor Z‐VAD‐FMK substantially failed to block cell death. Thus the possibility that LGI1‐triggered apoptosis may involve initiator caspases linked to activation of death receptors, appears unlikely. The decreased ratio of Bcl‐2 to Bax suggests that apoptosis is initiated by the intrinsic mitochondrial pathway through the release of caspase‐dependent and ‐independent apoptogenic molecules. This study provides the first evidence that LGI1 controls neuronal cell survival, suggesting its role in the development of the nervous system in relation to the pathogenesis of neuroblastoma and ADLTE. J. Cell. Physiol. © 2006 Wiley‐Liss, Inc.
Mono‐components for decomposition of signals
Authors: Qian Tao 
Published: March 2006

AbstractThis note further carries on the study of the eigenfunction problem: Find f(t)=ρ(t)eiθ(t) such that Hf=−if, ρ(t)⩾0 and θ′(t)⩾0, a.e. where H is Hilbert transform. Functions satisfying the above conditions are called mono‐components, that have been sought in time‐frequency analysis. A systematic study for the particular case ρ≡1 with demonstrative results in relation to Möbius transform and Blaschke products has been pursued by a number of authors. In this note, as a key step, we characterize a fundamental class of solutions of the eigenfunction problem for the general case ρ⩾0. The class of solutions is identical to a special class of starlike functions of one complex variable, called circular H‐atoms. They are building blocks of circular mono‐components. We first study the unit circle context, and then derive the counterpart results on the line. The parallel case of dual mono‐components is also studied. Copyright © 2006 John Wiley & Sons, Ltd.
Single muscle fiber size and contractility after spinal cord injury in rats
Authors: Frontera Walter R. , Choi Howard , Krishnan Gomathi , Krivickas Lisa S. , Sabharwal Sunil , Teng Yang D. 
Published: March 2006

AbstractSpinal cord injury (SCI) results in muscle weakness but the degree of impairment at the level of single fibers is not known. The purpose of this study was to examine the effects of T9–level SCI on single muscle fibers from the tibialis anterior of rats. Significant decreases in cross‐sectional area (CSA), maximal force (Po), and specific force (SF = Po/CSA) were noted at 2 weeks. Atrophy and force‐generating capacity were reversed at 4 weeks, but SF remained impaired. Maximum shortening velocity (Vo) did not change after injury. SCI thus appears to affect various contractile properties of single muscle fibers differently. Normal cage activity may partially restore function but new interventions are needed to restore muscle fiber quality. Muscle Nerve, 2006
Unmyelinated tactile afferents underpin detection of low‐force monofilaments
Authors: Cole Jonathan , Bushnell M. Catherine , McGlone Francis , Elam Mikael , Lamarre Yves , Vallbo Åke , Olausson Håkan 
Published: March 2006

AbstractHuman hairy but not glabrous skin has unmyelinated (C) tactile (CT) afferents that project to insular cortex. We studied two subjects with the rare sensory neuronopathy syndrome who lack A‐beta fibers but have relatively preserved C‐fiber function. Weak monofilaments were detected on hairy skin alone. Hence, the ability to detect light touch does not depend entirely on the A‐beta somatosensory system; CT afferents may contribute to the detection of weak monofilaments. Muscle Nerve, 2006
Obtaining online approximation algorithms for facility dispersion from offline algorithms
Authors: Rosenkrantz Daniel J. , Tayi Giri K. , Ravi S.S. 
Published: March 2006

AbstractFacility dispersion problems arise in the context of placing obnoxious facilities and retail outlets. In the offline version of such a problem, the input consists of a complete graph on n nodes, a nonnegative weight (distance) for each edge, and the number k ⩽ n of facilities to be placed. The goal is to choose a facility placement consisting of k nodes so as to maximize a given measure of the distances among the facilities. Here, we consider an online version of the problem where the value of k is not known apriori; instead, requests for facilities arrive one at a time. It is also required that previously placed facilities cannot be moved or eliminated. Our main result is that for any objective that satisfies two properties, namely monotonicity and graceful degradation, any offline approximation algorithm with a performance guarantee ρ can be used to develop an algorithm with competitive ratio cρ for the online version, where c is a constant independent of the problem instance. Objectives for which our result applies include the average edge weight and average weight of a star subgraph. The result holds even when the edge weights do not satisfy the triangle inequality. We also identify dispersion objectives for which the offline and online versions have different behaviors when only one of the above two properties is satisfied. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 47(4), 206–217 2006
Mode‐I fracture behavior of carbon/epoxy plain‐weave composites containing double‐edge through‐the‐thickness cracks
Authors: Lee Dongyeon , Gowayed Yasser 
Published: March 2006

AbstractA stress method to evaluate the stress intensity factor at the ends of a discontinuity contained by an orthotropic medium is developed. Unlike the classic stress method, of which determination of the stress intensity factor (SIF) is largely dependent on data collected from singularity‐dominated zone, the proposed stress method is based on a stress expression in the form of multiterm expansion, including two higher‐order terms. By adopting higher‐order terms, far‐field effect can be taken into consideration. Carbon/epoxy plain‐weave textile composites are prepared and tensile‐tested with double‐edge notched (DEN) configuration. Effective crack length (a/W) ranges from 0.064 to 0.624. Prediction of the proposed model matches the definition, $\sigma_{\infty}\sqrt{\pi a}$, with errors less than 5% for 0.064 < a/W < 0.402, whereas errors are reported up to 45.78% for 0.413 < a/W < 0.624. It is postulated that the errors beyond a/W = 0.4 results from finite geometry and interaction between cracks. A strain‐gage test is carried out to verify the proposed stress method, utilizing two strain gages to realize the three‐parameter strain gage method. The test result exhibits good agreement with the proposed method. POLYM. COMPOS. 27:213–220, 2006. © 2006 Society of Plastics Engineers
Synthesis and properties of epoxy/TiO2 composite materials
Authors: Huang K. S. , Nien Y. H. , Chen J. S. , Shieh T. R. , Chen J. W. 
Published: March 2006

AbstractEpoxy/TiO2 composites were prepared by solution mixture method, in which epoxy resin and nano‐TiO2 liquid were mixed in the presence of methyl isobutylketone. According to the experimental results, hydrogen bonds can be formed by mixing TiO2 particles and epoxy resin. The SEM analysis suggests that TiO2 particles are uniformly distributed within the material, while some silver streaks occur at the surface of materials. Besides, thermo‐resistance and mechanical property of materials are found to improve with the addition of TiO2, but degrades if the nano‐TiO2 is the excess of 3%. Furthermore, these properties can be improved with the increasing concentration of methyl isobutylketone. POLYM. COMPOS., 27:195–200, 2006. © 2006 Society of Plastics Engineers.
Preparation of conductive polyaniline/epoxy composite
Authors: Yang Qinghao , Wei Shenggui , Cheng Guangxu 
Published: March 2006

AbstractConductive PANI (polyaniline)/epoxy composites were prepared by curing of the premix of PANI, which was synthesized in a multiple sulfonic acid system containing toluenesulfonic acid and dodecylbenzenesulfonic acid, and epoxy resin with methyl tetrahydrogen phenyl anhydride/triethylamine. The effects of the loadings of the curing agent, the accelerants as well as their types, and the PANI on the conductivities of the composites were studied. With increasing loadings of curing agent, conductivities of the composites increased first and decreased then, which is a synergistic effect of the PANI loading and its doping states. Under relatively lower loading of accelerant, conductivities of the composites increased with increase of PANI loading, whereas with higher loading of accelerant, the conductivities were affected by both the PANI and the accelerant loadings. Conductivity as high as 3 × 10−5 S/cm was achieved for curing of the composite containing 7.5 wt% of PANI and 4 wt% of accelerant at 80°C, which is suffice in application of electrostatic discharging. POLYM. COMPOS. 27:201–204, 2006. © 2006 Society of Plastics Engineers
Profile extrusion and mechanical properties of crosslinked wood–thermoplastic composites
Authors: Bengtsson Magnus , Oksman Kristiina , Stark Nicole M. 
Published: March 2006

AbstractChallenges for wood‐thermoplastic composites to be utilized in structural applications are to lower product weight and to improve the long‐term load performance. Silane crosslinking of the composites is one way to reduce the creep during long‐term loading and to improve the mechanical properties. In this study, silane crosslinked wood‐polyethylene composites were produced by reactive extrusion and subsequently manufactured into rectangular profiles. The silane crosslinked composites were stored in a sauna at 90 °C to increase the degree of crosslinking. The toughness of the silane crosslinked composites was significantly higher than for the non‐crosslinked composites. Improved adhesion between the wood and polyethylene phases is most likely the reason for the improved toughness of the crosslinked composites. There was no significant difference in flexural modulus between the crosslinked and non‐crosslinked composites. In addition, impact testing showed that the impact strength of the crosslinked composites was considerable higher (at least double) than the non‐crosslinked. The effect of temperature on the impact strength of the composites indicated slightly higher impact strength at −30 °C than at 0° and at 25 °C, and then an incrase in impact strength at 60 °C. Crosslinking also reduced the creep response during short‐term loading. Moreover, scanning electron microscopy on the fracture surface of the crosslinked composites revealed good adhesion between the polyethylene and wood phases. POLYM. COMPOS. 27:184–194, 2006. © 2006 Society of Plastics Engineers
Fluorinated and oxyfluorinated short Kevlar fiber‐reinforced ethylene propylene polymer
Authors: Mukherjee M. , Das C.K. , Kharitonov A.P. 
Published: March 2006

AbstractThe thermomechanical behavior of fluorinated and oxyfluorinated Kevlar fiber‐reinforced ethylene propylene (EP) composites has been studied. The composites have been prepared using brabender mixer and are cured using compression molding technique. FTIR study has been performed to understand the chemical reaction occurred due to modification of composites. Thermal behavior and crystallinity have been studied by DSC, TGA, DMTA, and XRD. These studies show that thermal stability, storage modulus, as well as crystallinity of the treated Kevlar fiber‐reinforced EP increases in comparison to the untreated derivative because the surface‐modified Kevlar fiber results in good adhesion between the fiber surface and EP matrix. Tensile strength increases in case of treated Kevlar fiber‐reinforced EP in comparison to the untreated one. SEM study supports all the above results. AFM results show that surface roughness increases because of the surface modification resulting from the incorporation of functional group‐induced Kevlar fiber. Polym. Compos. 27:205–212, 2006. © 2006 Society of Plastics Engineers
Preparation and characterization of mesoporous silica thin films from polyethoxysiloxanes
Authors: Gunji Takahiro , Shimano Ryosuke , Arimitsu Koji , Abe Yoshimoto 
Published: March 2006

AbstractTetraethoxysilane (TEOS) and polyethoxysiloxanes (PEOSs; prepared by the acid‐catalyzed hydrolytic polycondensation of TEOS) were subjected to the sol–gel process in the presence of cetyltrimethylammonium bromide (CTAB), respectively. The PEOSs with Mw 700–26,000, as prepared by sol–gel coating of TEOS and PEOS under various conditions, were used. Uniform and crack‐free thin films of thickness 276–613 nm were prepared by spin‐coating of a PEOS solution containing CTAB. When the coating films were sintered at 400 °C, the combustion of ethoxy groups and CTAB took place to provide porous silica thin films. The structure of the thin films was found to be dependent on the molecular weight of PEOS and the molar ratio of CTAB/Si: lamellar or hexagonal phase was observed for Mw less than 15,000 and for CTAB/Si molar ratios greater than 0.10. Honeycomb structures were observed for Mw less than 5000 and for CTAB/Si molar ratios of 0.15. The honeycomb structure was also observed by atomic force microscopy and transmission electron microscope. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2542–2550, 2006
Effect of iodine on morphology changes of spray deposited nanocrystalline CdSe:I, CdTe:I and HgTe:I thin films
Authors: RangaRao A. , Dutta V. 
Published: March 2006

AbstractThe low‐temperature preparation of nanofibres and nanotubes in iodine‐doped CdX (X = Se, Te) and HgTe thin films is reported. Iodine was used as an n‐type dopant in CdX and HgTe. The films were deposited on glass substrates at 200 °C by spray deposition of iodine‐doped nanoparticles prepared using a solvothermal method. The surface morphology of iodine‐doped CdX films shows the formation of nanofibers and that of iodine‐doped HgTe films shows the formation of nanotubes ∼4 µm long with an average diameter of ∼45 nm. Selected‐area diffraction patterns show the formation of cubic HgTe nanotubes with lattice parameter a = 0.6467 nm. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Doping effects of a nano‐nitride layer at the interfaces of a NiO/Co/Cu/Co/Cu structure
Authors: Zhao Z. C. , Wang H. , Xiao S. Q. , Zhong X. X. , Gu Y. Z. , Xia Y. X. , Jin Q. Y. , Wu X. S. 
Published: March 2006

AbstractNiO/Co/Cu/Co/Cu spin valves with a doped nano‐nitride layer (NNL) at different interfaces have been investigated. The positions of the NNL have a significant influence on magnetoresistance (MR). When the NNL is doped at the top interface with the resulting structure of NiO/Co/Cu/Co/NNL/Cu, the MR is higher than that of the non‐doped structure, while MR becomes relatively small when the NNL is doped at the bottom interface between NiO and Co. A detailed analysis is given. This study might be considered as useful for furthering understanding of how to tailor MR with NNLs. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mg‐doped AlGaN grown on an AlN/sapphire template by metalorganic chemical vapour deposition
Authors: Yu Hongbo , Strupinski Wlodek , Butun Serkan , Ozbay Ekmel 
Published: March 2006

AbstractThe growth of high‐performance Mg‐doped p‐type Alx Ga1–x N (x = 0.35) layers using low‐pressure metalorganic chemical vapour deposition on an AlN/sapphire template is reported. The influence of growth conditions on the p‐type conductivity of the Alx Ga1–x N (x = 0.35) alloy was investigated. It was found that the p‐type resistivity of the AlGaN alloy demonstrates a marked dependence on the Mg concentration, V/III ratio and group III element flow rate. A minimum p‐type resistivity of 3.5 Ω cm for Alx Ga1–x N (x = 0.35) epilayers was achieved. A Ni/Au (10 nm/100 nm) ohmic contact was also fabricated and a specific contact resistivity of 8.1 × 10–2 Ω cm2 was measured. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear absorption in silicon and the prospects of mid‐infrared silicon Raman lasers
Authors: Raghunathan Varun , Shori Ramesh , Stafsudd Oscar M. , Jalali Bahram 
Published: March 2006

AbstractWe present the first experimental results of nonlinear absorption in silicon at the mid infrared wavelengths. Nonlinear losses due to two‐photon and free‐carrier absorption that are found to degrade near infrared silicon Raman devices become negligible at photon energies less than half the bandgap (i.e., λ > 2.2 µm in wavelength). Moreover, the low loss window for linear absorption in silicon extends from 1.2 to 6.5 µm. These factors along with the excellent thermal conductivity and high optical damage threshold renders silicon an ideal material for building Raman lasers and amplifiers that operate in the mid infrared wavelengths. This new technology will expand the application space of silicon photonics beyond data communication and into biochemical sensing, laser medicine, and LIDAR. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the nonmagnetic impurities on the spin‐1 Heisenberg chain SrNi2V2O8 system
Authors: Giapintzakis J. , Androulakis J. , Syskakis E. , Papageorgiou Th. P. , Apostolopoulos G. , Thanos S. , Papastaikoudis C. 
Published: March 2006

AbstractDc‐magnetization and heat capacity measurements on polycrystalline samples of SrNi2–x Mgx V2O8 (x = 0 and 0.05) are reported. The magnetization data suggest that both compounds are S = 1 quasi one‐dimensional Heisenberg antiferromagnets. The substitution of non‐magnetic impurity Mg2+ ions for Ni2+ induces a magnetic phase transition at ∼3.7 K. A simple Hamiltonian model is proposed for these systems giving good quantitative agreement with the experimental magnetization data. The intrachain magnetic exchange constant (J 1/k B) and the Haldane gap (Δ ) for both compounds are estimated to be ∼105 K and ∼58.3 K (5.02 meV), respectively. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature dependence effective activation energy in Tl2Ba2CaCu2O8 thin film
Authors: Liu S. L. , Wu G. J. , Shan L. , Wu J. , Xu X. B. , Jin X. , Shao H. M. 
Published: March 2006

AbstractBy considering the competition of thermal activation and effective pinning, a general description of temperature dependence resistivity under magnetic fields has been deduced on high temperature superconductors. The temperature dependence resistivity is a function of the energy ratio of thermal actviation and pinning. Based on vortex glass phase transition analysis, the temperature dependence activation energy can be obtained from the resistivity transition under magnetic fields. It is found that the activation energy can be scaled onto a single parabola. The experiments on Tl‐2212 thin film and other superconductors support our model. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defect contributions to conductivity in poly(3‐hexylthiophene)?
Authors: Caruso A. N. , Feng D.‐Q. , Losovyj Ya. B. , Schulz D. L. , Balaz Snjezana , Rosa Luis G. , Sokolov A. , Doudin B. , Dowben P. A. 
Published: March 2006

AbstractWe find evidence for a gradual change in the electronic properties of spin coated poly(3‐hexylthiophene) thin films with temperature. The conduction properties appears to be mediated by hopping conduction dominated by a low density of defects states within the highest occupied molecular orbital to lowest unoccupied molecular orbital gap, not by a change in band gap. The photoemission and transport measurements indicate a loss of charge mobility or carrier concentration occurs with decreasing temperature, while the molecular configuration (through chain conjugation) also changes with temperature. The defects states identified by photoemission (–1.7 eV) as well as others contributing to the transport properties are believed to be very heterogeneous along the polymer backbone. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)