bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adult neurogenesis and brain regeneration in zebrafish
Authors: Kizil Caghan , Kaslin Jan , Kroehne Volker , Brand Michael 
Published: May 2011

AbstractAdult neurogenesis is a widespread trait of vertebrates; however, the degree of this ability and the underlying activity of the adult neural stem cells differ vastly among species. In contrast to mammals that have limited neurogenesis in their adult brains, zebrafish can constitutively produce new neurons along the whole rostrocaudal brain axis throughout its life. This feature of adult zebrafish brain relies on the presence of stem/progenitor cells that continuously proliferate, and the permissive environment of zebrafish brain for neurogenesis. Zebrafish has also an extensive regenerative capacity, which manifests itself in responding to central nervous system injuries by producing new neurons to replenish the lost ones. This ability makes zebrafish a useful model organism for understanding the stem cell activity in the brain, and the molecular programs required for central nervous system regeneration. In this review, we will discuss the current knowledge on the stem cell niches, the characteristics of the stem/progenitor cells, how they are regulated and their involvement in the regeneration response of the adult zebrafish brain. We will also emphasize the open questions that may help guide the future research. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 72: 429–461, 2012
Reserve pool neuron transmitter respecification: Novel neuroplasticity
Authors: Dulcis Davide , Spitzer Nicholas C. 
Published: May 2011

AbstractThe identity of the neurotransmitters expressed by neurons has been thought to be fixed and immutable, but recent studies demonstrate that changes in electrical activity can rapidly and reversibly reconfigure the transmitters and corresponding transmitter receptors that neurons express. Induction of transmitter expression can be achieved by selective activation of afferents recruited by a physiological range of sensory input. Strikingly, neurons acquiring an additional transmitter project to appropriate targets prior to transmitter respecification in some cases, indicating the presence of reserve pools of neurons that can boost circuit function. We discuss the evidence for such reserve pools, their likely locations and ways to test for their existence, and the potential clinical value of such circuit‐specific neurotransmitter respecification for treatments of neurological disorders. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 72: 465–474, 2012
Cerebrospinal fluid control of neurogenesis induced by retinoic acid during early brain development
Authors: Alonso M. I. , Martín C. , Carnicero E. , Bueno D. , Gato A. 
Published: May 2011

AbstractEmbryonic‐cerebrospinal fluid (E‐CSF) plays crucial roles in early brain development including the control of neurogenesis. Although FGF2 and lipoproteins present in the E‐CSF have previously been shown to be involved in neurogenesis, the main factor triggering this process remains unknown. E‐CSF contains all‐trans‐retinol and retinol‐binding protein involved in the synthesis of retinoic acid (RA), a neurogenesis inducer. In early chick embryo brain, only the mesencephalic‐rombencephalic isthmus (IsO) is able to synthesize RA. Here we show that in chick embryo brain development: (1) E‐CSF helps to control RA synthesis in the IsO by means of the RBP and all‐trans‐retinol it contains; (2) E‐CSF has retinoic acid activity, which suggests it may act as a diffusion pathway for RA; and (3) the influence of E‐CSF on embryonic brain neurogenesis is to a large extent due to its involvement in RA synthesis. These data help to understand neurogenesis from neural progenitor cells. Developmental Dynamics 240:1650–1659, 2011. © 2011 Wiley‐Liss, Inc.
Neural crest cells retain their capability for multipotential differentiation even after lineage‐restricted stages
Authors: Motohashi Tsutomu , Yamanaka Katsumasa , Chiba Kairi , Miyajima Kentaro , Aoki Hitomi , Hirobe Tomohisa , Kunisada Takahiro 
Published: May 2011

AbstractMultipotency of neural crest cells (NC cells) is thought to be a transient phase at the early stage of their generation; after NC cells emerge from the neural tube, they are specified into the lineage‐restricted precursors. We analyzed the differentiation of early‐stage NC‐like cells derived from Sox10‐IRES‐Venus ES cells, where the expression of Sox10 can be visualized with a fluorescent protein. Unexpectedly, both the Sox10+/Kit− cells and the Sox10+/Kit+ cells, which were restricted in vivo to the neuron (N)‐glial cell (G) lineage and melanocyte (M) lineage, respectively, generated N, G, and M, showing that they retain multipotency. We generated mice from the Sox10‐IRES‐Venus ES cells and analyzed the differentiation of their NC cells. Both the Sox10+/Kit− cells and Sox10+/Kit+ cells isolated from these mice formed colonies containing N, G, and M, showing that they are also multipotent. These findings suggest that NC cells retain multipotency even after the initial lineage‐restricted stages. Developmental Dynamics 240:1681–1693, 2011. © 2011 Wiley‐Liss, Inc.
Synthesis and Characterization of Single‐Crystalline MnFe2O4 Ferrite Nanocrystals and Their Possible Application in Water Treatment
Authors: Wang YingQi , Cheng RongMin , Wen Zi , Zhao LiJun 
Published: May 2011

AbstractManganese ferrite (MnFe2O4) nanospheres and nano‐octahedra with a narrow size distribution were synthesized by a simple solvothermal method. Here, potassium permanganate (KMnO4) was used as reactant and oxidant for the synthesis of MnFe2O4 ferrite nanocrystals. With the use of hydrazine hydrate, the oxidation rate of ferrous ions was kept under control, and the particle size of MnFe2O4 was limited. The results of control experiments reveal that alkalinity and type of solvent are important factors affecting the morphology and crystallization of MnFe2O4 nanocrystals. Both of the as‐prepared samples exhibit ferromagnetic behavior at room temperature. Especially, the saturation magnetization of MnFe2O4 nanospheres with 50 nm diameter is 79 emu/g, which is among the best values reported so far. The nanoparticles also showed good performance in removal of pollutants like Congo red, CrVI, and PbII from water by adsorption, even at neutral pH.
Asymmetric Synthesis of Octahedral Coordination Complexes
Authors: Meggers Eric 
Published: May 2011

AbstractIn contrast to stereoselective organic chemistry, which has established sophisticated synthetic strategies to control the relative and absolute configuration at tetrahedral carbon atoms, the stereochemical control of octahedral coordination spheres is much less understood. This microreview reflects on the state of the art of asymmetric coordination chemistry of octahedral complexes within the historical context, including asymmetric coordination chemistry evolved by nature, the predetermination of metal‐centered chirality with tailored chiral ligands, chiral‐anion‐mediated asymmetric synthesis, chiral‐auxiliary‐mediated asymmetric coordination chemistry, and finally, very recent work on the catalytic asymmetric synthesis of an octahedral coordination complex. The stereocontrolled synthesis of octahedral metal complexes is an important problem of contemporary coordination chemistry and will ultimately provide the necessary synthetic tools to fully exploit the opportunities provided by the rich stereochemistry of octahedral coordination geometries.
Mechanistic Insights into the Palladium‐Catalysed Asymmetric Phosphination of Cyclohexenyl Triflate (Eur. J. Inorg. Chem. 16/2011)
Authors: Julienne Delphine , Delacroix Olivier , Lohier Jean‐François , de Oliveira‐Santos Jana Sopkova , Gaumont Annie‐Claude 
Published: May 2011

AbstractThe cover picture shows the catalytic cycle of the Pd‐catalysed asymmetric phosphination involving an achiral alkenyl triflate and a racemic boron phosphide. A mechanistic study illustrated by the gears in the background allowed us to identify each main intermediate of this catalytic cycle. To proceed, tools such as 31P NMR spectroscopy and X‐ray crystallography were used. Details are discussed in the article by A.‐C. Gaumont et al. on p. 2489 ff.
A Flexible Approach to 6,5‐Benzannulated Spiroketals
Authors: Wilson Zoe E. , Hubert Jonathan G. , Brimble Margaret A. 
Published: May 2011

AbstractA novel route to simple 6,5‐benzannulated spiroketal analogues has been developed. A convergent Horner–Wadsworth–Emmons olefination enabled ready assembly of the spiroketal precursors. Use of a benzyl protecting group strategy enabled an efficient one‐pot hydrogenation/deprotection/spiroketalisation process to be employed providing a robust method to access a range of substituted aromatic monobenzannulated spiroketals.
A Synthetic Route to α‐Substituted Butenolides: Enantioselective Synthesis of (+)‐Ancepsenolide
Authors: Ghobril Cynthia , Kister Jérémy , Baati Rachid 
Published: May 2011

AbstractA variety of α‐substituted butenolides was efficiently synthesized starting from commercially available tetronic acid and carboxylic acids in four steps. The effectiveness of this approach is illustrated in the short synthesis of one of the first butenolide acetogenins: (+)‐ancepsenolide.
A Facile Electrochemical Immunosensor with Mesoporous Alumina for Detection of Carcinoembryonic Antigen
Authors: Dai Yuxue , Li He , Wu Dan , Li Ru , Zhao Yanfang , Liu Bao , Cai Yanyan , Yang Minghui , Du Bin , Wei Qin 
Published: May 2011

AbstractA label‐free electrochemical immunosensor for the sensitive determination of carcinoembryonic antigen (CEA) was fabricated by immobilizing anti‐CEA onto mesoporous alumina (meso‐Al2O3) dispersed in chitosan (0.5 %wt) by the cross‐linking method using glutaraldehyde. Due to its plenty of active sites, meso‐Al2O3 showed high catalysis towards hydroquinone. With the electrocatalytic ability of meso‐Al2O3 for the reduction of hydroquinone, the current signal of the antigen‐antibody reaction was amplified and the enhanced sensitivity was achieved. The current decreased linearly with CEA concentration in the range of 0.04 to 10 ng/mL (26 pg/mL, S/N=3). The immunosensor had good selectivity and wonderful stability. Furthermore it was applied to the analysis of CEA in serum sample with satisfactory results.
Development and Evaluation of a Nanoporous Iron (Hydr)oxide Electrode for Phosphate Sensing
Authors: Moss Rachel E. , Jackowski Jennifer J. , de Souza Castilho Michelle , Anderson Marc A. 
Published: May 2011

AbstractNanoporous iron (hydr)oxide electrodes are evaluated as phosphate sensors using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The intensity of the reduction peak current (Icp) of the ferrihydrite working electrode is tied to phosphate concentration at low pH; however, a hematite electrode combined with the use of EIS provided reliable sensing data at multiple pH values. Nanoporous hematite working electrodes produced an impedance phase component (θ) that shifts with increasing phosphate, and, at chosen frequencies, θ values were fitted for the range 1 nM to 0.1 mM phosphate at pH 4 and pH 7 in 5 mM NaClO4.
Controlled struvite precipitation from belt press filtrate of anaerobic digester in a CSTR
Authors: Lew Beni , Phalah Somaya , Rebhum Menachem 
Published: May 2011

AbstractStruvite (MgNH4PO4·6H2O) is known to precipitate and clog pipes and pumps, causing operational difficulties and expenses downstream of the anaerobic digester in wastewater treatment plants around the world. This work focused on determining the most appropriate reactor operational conditions (focus on hydraulic retention time and aeration rate) required for attaining the most homogeneous controlled struvite precipitation in order to reduce pipes and pumps clogging downstream of the digester. To this end a continuous laboratory‐scale completely stirred tank reactor aerated (for CO2 stripping) reactor was operated at different hydraulic retention times and aeration rates and precipitate composition was determined. A minimum pH of 8.0 was calculated and experimental observed as necessary to attain struvite precipitation to its maximum potential to prevent clogging. To reach this pH value a minimum HRT of 0.5 hours with aeration flow rate of 11.2 m3/h/m3 and/or 15‐min HRT with an air flow of 46.7 m3/h/m3 was necessary for the reactor studied. Struvite precipitation kinetics was observed to be much faster than other minerals that can precipitate and a decrease in HRT promoted a precipitate richer in struvite. However, for all HRT and air flows studied the precipitate obtained can be considered to be poor in struvite and can hardly be reused in agriculture. © 2011 American Institute of Chemical Engineers Environ Prog, 2011
Multiwavelet transform based classification of PQ events
Authors: Kapoor Rajiv , Saini Manish Kumar 
Published: May 2011

SUMMARYWavelets have been used extensively in the recent past. The work presented uses multiwavelet because of its inherent property to resolve the signal better than all single wavelets. Multiwavelets are based on more than one scaling function. The resolution is better compared to Daubechies (D4) and hence the event can be detected from lesser number of samples as compared to Daubechies (D4). The proposed methodology utilizes an enhanced resolving capability of multiwavelet to recognize power system disturbances. Dempster–Shafer (DS), an intelligent classifier, has been implemented and tested for various PQ events. Two sub‐classifiers, heuristic classifier and statistical classifier (χ2 distribution), have been used to support and strengthen the structural identification and temporal distribution factor of DS classifier. Results on various PQ events, such as voltage sag, voltage swell, outage, interruption, impulsive‐transient (IT), oscillatory‐transient (OT), noise, and notching, show that multiwavelets can detect and classify different PQ events efficiently and consistently. Copyright © 2011 John Wiley & Sons, Ltd.
Ultra high‐voltage gas‐insulated switchgear – a technology milestone
Authors: Riechert Uwe , Holaus Walter 
Published: May 2011

SUMMARYChina is in urgent need of electrical power. Huge power plants are built all over the country and the enormous flow of electrical power to the large megacities has to cross several thousand kilometres from the source to the end user. At those dimensions, losses of the power lines can be significant. The State Grid Corporation of China (SGCC) is thus aiming for 1100 kV as the voltage level for AC transmission to keep losses as low as possible, a step into a new area of electrical grids. Asea Brown Boveri (ABB), together with its partners and suppliers, has developed the heart of such a system – a gas‐insulated switchgear (GIS) design – that could pass all the tests with this groundbreaking technology. Many years of experience at voltage levels of up to 800 kV are available as the basis for developing GIS for 1100 kV. Nevertheless, the individual components such as circuit‐breakers (CB) and disconnectors differ greatly from the known designs. As regards the CB, for instance, it emerges that a design with the closing resistor in a parallel tank is advantageous. The very fast transient overvoltages become more important for the disconnector design. Copyright © 2011 John Wiley & Sons, Ltd.
A least‐square weighted residual method for level set formulation
Authors: Choi Hyoung Gwon 
Published: May 2011

SUMMARYIn this paper, a least‐square weighted residual method (LSWRM) for level set (LS) formulation is introduced to achieve interface capturing in two‐dimensional (2D) and three‐dimensional (3D) problems. An LSWRM was adopted for two semi‐discretized advection and reinitialization equations of the LS formulation. The present LSWRM provided good mathematical properties such as natural numerical diffusion and the symmetry of the resulting algebraic systems for the advection and reinitialization equations. The proposed method was validated by solving some 2D and 3D benchmark problems such as those involving a rotating slotted disk, the rotation of a slotted sphere, and a time‐reversed single‐vortex flow and a deformation problem of a spherical fluid. The numerical results were compared with those obtained from essentially non‐oscillatory type formulations and particle LS methods. Further, the proposed LSWRM for the LS formulation was coupled with a splitting finite element method code to solve the incompressible Navier–Stokes equations, and then, the collapse of a 3D broken dam flow was well simulated; in the simulation, the entrapping of air and the splashing of the surge front of water were reproduced. The mass conservation of the present method was found to be satisfactory during the entire simulation. Copyright © 2011 John Wiley & Sons, Ltd.
A consistent and fast weakly compressible smoothed particle hydrodynamics with a new wall boundary condition
Authors: Fatehi R. , Manzari M. T. 
Published: May 2011

SUMMARYA modified weakly compressible smoothed particle hydrodynamics (WCSPH) is presented, which utilizes consistent discretization schemes for spatial derivatives in the flow equations. Here, each SPH particle is considered as a computational point that represents a specific part of the fluid. To overcome non‐physical oscillations that usually arise in standard WCSPH, we modified the mass conservation equation by using a numerical filter. This modification is based on the difference between two discretization schemes used for the term . Furthermore, a new implementation of wall boundary condition in SPH is introduced. This condition is imposed on the pressure of wall boundary particles to ensure that the acceleration of each boundary particle in normal direction to the wall is zero. Thus, no penetration through walls will occur. To examine the performance of the modified method, we solved a series of two‐dimensional incompressible internal flow benchmark problems. By comparing the result with analytical solutions and the results of the standard WCSPH, we show that the use of consistent schemes in conjunction with the proposed numerical filter improves both accuracy and speed of the numerical method. Copyright © 2011 John Wiley & Sons, Ltd.
New insights into “GPR40‐CREB interaction inadult neurogenesis” specific for primates
Authors: Boneva Nadezhda B. , Yamashima Tetsumori 
Published: May 2011

AbstractPolyunsaturated fatty acids (PUFA), such as docosahexaenoic (DHA) and arachidonic acids (ARA) are known to be closely related to the brain development and also have beneficial effects on adult neurogenesis, learning, and mental disorders. Although PUFA were demonstrated as ligands for G protein‐coupled receptor 40 (GPR40), their signaling mechanism in the brain, especially in the neurogenic niche, remains unknown. Using a monkey model of ischemia‐enhanced hippocampal neurogenesis, we studied the spatial correlation between GPR40 and the phosphorylated cAMP response element‐binding protein (pCREB), a transcription factor involved in adult neurogenesis, learning and memory. Furthermore, the brain‐derived neurotrophic factor (BDNF) and its receptor tropomyosin receptor kinase B (TrkB), both being downstream gene transcripts of pCREB, were studied. Similar to the dynamic change of GPR40 as the authors reported previously, pCREB was up‐regulated significantly after transient global brain ischemia on Western blots, and this was associated with an enhanced hippocampal neurogenesis. Immunofluorescence microscopic analysis showed that GPR40 and pCREB expression patterns were completely identical, and they were coexpressed in both mature and newborn neurons as well as in the astrocytes residing in the subgranular zone (SGZ). GPR40/pCREB double‐positive cells significantly increased in the SGZ on day 15 after ischemia. The mature form of BDNF (mBDNF) and TrkB receptor showed no remarkable changes on Western blots, although proBDNF (precursor of mBDNF) was maximal on day 9. Immunofluorescence microscopy showed that the newborn neurons expressed BDNF, but not TrkB. These results altogether suggest that PUFA, GPR40, pCREB, and BDNF may be engaged in the same signaling pathway to promote neurogenesis in the adult primate hippocampus. © 2011 Wiley‐Liss, Inc.
Analysing the Variability of Rainfall for Drought Progonosis in Jharkhand State: A Statistical Approach
Authors: Pandey Swati , Kumar Manoj , Chakraborty Soubhik , Mahanti N. C. 
Published: May 2011

ABSTRACTAgriculture in the state of Jharkhand depends on the southwest monsoon which brings about 80% of the mean annual precipitation. The high variability in rainfall generally leads to meteorological drought conditions, demanding a large time domain analysis of rainfall behaviour. In the present paper, daily rainfall data for 49 years (1956–2006) of Ranchi District, Jharkhand state of India, were analyzed for the probability and variability of rainfall. The monsoon weeks, i.e. the 21st to the 41st, were considered and it was found that the rainfall distribution can be modeled by a negative binomial distribution. Additionally, by denoting a wet week by W and a dry week by D, the unconditional probability P(W) and the conditional probabilities P(W/W) and P(W/D) for these weeks were evaluated using a first‐order Markov chain at three probability levels (30, 50 and 70 mm). The results were checked against a uniform model with the help of the Kolmogorov‐Smirnov test and it was found that in most cases they supported the uniform distribution assumption. Lower probability (less than 0.50) of getting 70 mm of rainfall under any probability conditions during the 27th to 38th weeks indicated the proneness of the region to drought during the crop growth and maturity stage under condition of initial rainfall failure during the crop sowing stage. Copyright © 2011 John Wiley & Sons, Ltd.
Thyroid hormone receptor β mediates thyroid hormone effects on bone remodeling and bone mass
Authors: Monfoulet Laurent-Emmanuel , Rabier Bénédicte , Dacquin Romain , Anginot Adrienne , Photsavang Johan , Jurdic Pierre , Vico Laurence , Malaval Luc , Chassande Olivier 
Published: May 2011

Abstract
Excess thyroid hormone (TH) in adults causes osteoporosis and increases fracture risk. However, the mechanisms by which TH affects bone turnover are not elucidated. In particular, the roles of thyroid hormone receptor (TR) isotypes in the mediation of TH effects on osteoblast-mediated bone formation and osteoclast-mediated bone resorption are not established. In this study we have induced experimental hypothyroidism or hyperthyroidism in adult wild-type, TRα- or TRβ-deficient mice and analyzed the effects of TH status on the structure and remodeling parameters of trabecular bone. In wild-type mice, excess TH decreased bone volume and mineralization. High TH concentrations were associated with a high bone-resorption activity, assessed by increased osteoclast surfaces and elevated concentrations of serum bone-resorption markers. Serum markers of bone formation also were higher in TH-treated mice. TRα deficiency did not prevent TH action on bone volume, bone mineralization, bone formation, or bone resorption. In contrast, TRβ deficiency blocked all the early effects of excess TH observed in wild-type mice. However, prolonged exposure to low or high TH concentrations of TRβ-deficient mice induced mild modifications of bone structure and remodeling parameters. Together our data suggest that TRβ receptors mediate the acute effects produced by transient changes of TH concentrations on bone remodeling, whereas TRα receptors mediate long-term effects of chronic alterations of TH metabolism. These data shed new light on the respective roles of TRs in the control of bone metabolism by TH. © 2011 American Society for Bone and Mineral Research