bluuebunny/crossref_metadata_2025_split huggingface dataset:
Species extrapolation for the 21st century
Authors: Celander Malin C , Goldstone Jared V , Denslow Nancy D , Iguchi Taisen , Kille Peter , Meyerhoff Roger D , Smith Ben A , Hutchinson Thomas H , Wheeler James R 
Published: October 2010

Abstract
Safety factors are used in ecological risk assessments to extrapolate from the toxic responses of laboratory test species to all species representing that group in the environment. More accurate extrapolation of species responses is important. Advances in understanding the mechanistic basis for toxicological responses and identifying molecular response pathways can provide a basis for extrapolation across species and, in part, an explanation for the variability in whole organism responses to toxicants. We highlight potential short- and medium-term development goals to meet our long-term aspiration of truly predictive in silico extrapolation across wildlife species' response to toxicants. A conceptual approach for considering cross-species extrapolation is presented. Critical information is required to establish evidence-based species extrapolation, including identification of critical molecular pathways and regulatory networks that are linked to the biological mode of action and species' homologies. A case study is presented that examines steroidogenesis inhibition in fish after exposure to fadrozole or prochloraz. Similar effects for each compound among fathead minnow, medaka, and zebrafish were attributed to similar inhibitor pharmacokinetic/pharmacodynamic distributions and sequences of cytochrome P45019A1/2 (CYP19A1/2). Rapid advances in homology modeling allow the prediction of interactions of chemicals with enzymes, for example, CYP19 aromatase, which would eventually allow a prediction of potential aromatase toxicity of new compounds across a range of species. Eventually, predictive models will be developed to extrapolate across species, although substantial research is still required. Knowledge gaps requiring research include defining differences in life histories (e.g., reproductive strategies), understanding tissue-specific gene expression, and defining the role of metabolism on toxic responses and how these collectively affect the power of interspecies extrapolation methods. Environ. Toxicol. Chem. 2011;30:52–63. © 2010 SETAC
Spectral p‐multigrid discontinuous Galerkin solution of the Navier–Stokes equations
Authors: Bassi F. , Franchina N. , Ghidoni A. , Rebay S. 
Published: October 2010

AbstractDiscontinuous Galerkin (DG) methods are very well suited for the construction of very high‐order approximations of the Euler and Navier–Stokes equations on unstructured and possibly nonconforming grids, but are rather demanding in terms of computational resources. In order to improve the computational efficiency of this class of methods, a high‐order spectral element DG approximation of the Navier–Stokes equations coupled with a p‐multigrid solution strategy based on a semi‐implicit Runge–Kutta smoother is considered here. The effectiveness of the proposed approach in the solution of compressible shockless flow problems is demonstrated on 2D inviscid and viscous test cases by comparison with both a p‐multigrid scheme with non‐spectral elements and a spectral element DG approach with an implicit time integration scheme. Copyright © 2010 John Wiley & Sons, Ltd.
Peristaltic motion of an Oldroyd‐B fluid in a channel with compliant walls
Authors: Hayat T. , Javed Maryiam , Ali N. 
Published: October 2010

AbstractThis paper is an analysis of the peristaltic flow of an Oldroyd‐B fluid in a channel with compliant walls. The flow is induced by the sinusoidal waves on the channel walls. A series solution of the resulting boundary value problem is derived under small amplitude assumption. Emphasis is placed on determining the effects of various interesting flow parameters. Copyright © 2010 John Wiley & Sons, Ltd.
Finite element simulation of sound propagation concerning meteorological conditions
Authors: Nomura T. , Takagi K. , Sato S. 
Published: October 2010

AbstractA finite element analysis method is investigated for the sound propagation problem in which meteorological conditions, such as wind or stratified atmospheric temperature distribution, are concerned. The basic equations are the coupled partial differential equation system in which the sound pressure and the fluid particle velocity are unknown variables. The quantities associated to the ambient atmospheric medium are assumed steady. Performance of the time integration methods are compared. The outgoing boundary condition and the impedance boundary conditions are introduced in the computational procedure. Vibrating thin flat plate as the sound source can be treated in terms of the fluid particle velocity on the plate surfaces. All these features are investigated through a number of numerical examples and the performances are satisfactory ones. Copyright © 2010 John Wiley & Sons, Ltd.
Influencing factors in image‐based fluid–structure interaction computation of cerebral aneurysms
Authors: Torii Ryo , Oshima Marie , Kobayashi Toshio , Takagi Kiyoshi , Tezduyar Tayfun E. 
Published: October 2010

AbstractWe review and summarize our research activities in fluid–structure interaction (FSI) analysis of cerebral aneurysms using anatomically realistic geometry models based on medical images. Emphasis is placed on influencing factors in computational FSI, and their role and clinical implications are discussed in terms of the wall shear stress (WSS). The key factors are: (1) arterial and aneurysm geometries, (2) wall structure modeling, (3) blood pressure, (4) outflow conditions and (5) inflow conditions. Among these, we find the impact of the arterial and aneurysm geometries to be the most significant. Blood pressure also has a significant impact on the WSS distribution; a hypothetical hypertensive blood pressure condition could help estimate the rupture risk for an aneurysm. We find the other three factors to be minor compared with the arterial and aneurysm geometries and blood pressure, although the level of influence could be unique to the middle cerebral artery aneurysms that we have been focusing on in our studies. Copyright © 2010 John Wiley & Sons, Ltd.
Mafic dykes derived from Early Cretaceous depleted mantle beneath the Dabie orogenic belt: implications for changing lithosphere mantle beneath Eastern China
Authors: Chen Ling , Ma Chang Q. , Zhang Jin Y. , Mason Roger , Zhang Chao 
Published: October 2010

AbstractSHRIMP zircon U–Pb geochronological, elemental and Sr–Nd isotopic data from Early Cretaceous mafic dykes in North Dabie orogenic belt elucidate a change of Mesozoic lithospheric mantle in eastern China. The dykes are predominantly dolerite with the major mineral assemblage clinopyroxene + hornblende + plagioclase and yield a SHRIMP zircon U–Pb age of 111.6 ± 5.3 Ma. They have a narrow range of SiO2 from 46.16% to 49.78%, and relative low concentrations of K2O (1.07−2.62%), Na2O (2.45−3.54%), Al2O3 (13.04−14.07%), and P2O5 (0.42−0.55%) but relatively high concentration of MgO (5.94–6.61%) with Mg# 52–54. All the samples are characterized by enrichment of large ion lithophile elements (LILE, e.g., Ba, Th) and high field strength elements (HFSE, e.g., Nb, Ti). (87Sr/86Sr)i ratios from 0.704 to 0.705, εNd values from 3.36 to 4.33 and mantle‐depletion Nd model ages (T2DM) in the range 0.56–0.64 Ga indicate that the magma of the Baiyashan mafic dykes was derived from a young depleted mantle source. This finding is different from previous research on mafic dykes in the age range 120–138 Ma that revealed enrichment of LILE and depletion of HFSE, high initial Sr isotopic ratios and negative εNd, value which represents an old enriched mantle source. Ours is the first report of the existence of Early Cretaceous depleted mantle in eastern China and it implies that changing of enriched mantle to depleted mantle occurred at ca. 112 Ma, associated with back‐arc extension which resulted from the subduction of the Palaeo‐Pacific Plate towards the Asian Continent. Copyright © 2010 John Wiley & Sons, Ltd.
Trilobites of the genus Dikelokephalina from Ordovician Gondwana and Avalonia
Authors: Fortey Richard A. 
Published: October 2010

AbstractThe trilobite Dikelokephalina is widespread across the Tremadocian Gondwana, Avalonia and Baltica palaeocontinents. The hitherto poorly known Anglo‐Welsh species D. furca (Salter, 1866) is revised on the basis of new and well‐preserved material. A new species, D. brenchleyi sp. nov., is described from the Anti‐Atlas, Morocco. The two species together provide a fuller understanding of the genus, and of the family, Dikelokephalinidae (Kobayashi, 1934), to which it has been assigned. Suggestions that this family may be a junior synonym of Hungaiidae (Raymond, 1924) are considered premature. D. brenchleyi sp. nov. apparently shows variation in mature segment number, a most unusual feature in post‐Cambrian trilobites. It is found in monospecific assemblages of large individuals which lack ventral median sutures, and a case is made that these individuals represent a mass gathering of individuals that have ceased to grow, for the purpose of fertilizing eggs, as happens in living Limulus. Copyright © 2010 John Wiley & Sons, Ltd.
Gist reasoning training in cognitively normal seniors
Authors: Anand Raksha , Chapman Sandra B. , Rackley Audette , Keebler Molly , Zientz Jennifer , Hart John 
Published: October 2010

AbstractObjectiveCognitive impairment is a key factor that threatens functionality and quality of life in seniors. Given the projection that the population of individuals 65 years of age and older will double within the next 25 years, a critical need exists to identify and test effectiveness of protocols that target higher‐order cognitive skills such as gist reasoning to maximize cognitive capacity in later life.Methods: This study examined the effects of eight hours of gist reasoning training in 26 cognitively normal seniors between the ages of 64‐85 years (M = 74.23, SD = 6.67).ResultsFindings suggest that top‐down strategy‐based gist reasoning training significantly improved abstraction ability, a skill relevant to everyday life, as well as generalized to untrained measures of executive function including concept abstraction, cognitive switching, and verbal fluency. Individuals with lower baseline ability to abstract gist showed the greatest gain in the target domain trained.ConclusionsThese findings highlight the potential value of engaging in cognitively challenging activities that involve gist reasoning, to strengthen and preserve cognitive capacity with aging. Copyright © 2010 John Wiley & Sons, Ltd.
Detection and characterization of single‐trial fMRI bold responses: Paradigm free mapping
Authors: Gaudes César Caballero , Petridou Natalia , Dryden Ian L. , Bai Li , Francis Susan T. , Gowland Penny A. 
Published: October 2010

AbstractThis work presents a novel method of mapping the brain's response to single stimuli in space and time without prior knowledge of the paradigm timing: paradigm free mapping (PFM). This method is based on deconvolution of the hemodynamic response from the voxel time series assuming a linear response and using a ridge‐regression algorithm. Statistical inference is performed by defining a spatio‐temporal t‐statistic and by controlling for multiple comparisons using the false discovery rate procedure. The methodology was validated on five subjects who performed self‐paced and visually cued finger tapping at 7 Tesla, with moderate (TR = 2 s) and high (TR = 0.4 s) temporal resolution. The results demonstrate that detection of single‐trial BOLD events is feasible without a priori information on the stimulus paradigm. The proposed method opens up the possibility of designing temporally unconstrained paradigms to study the cortical response to unpredictable mental events. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Two New Disulfated Triterpenoids from Zygophyllum fabago
Authors: Khan Saleha S. , Khan Afsar , Ahmed Amir , Ahmad Viqar U. , Farooq Umar , Arshad Saima , Bader Sadia , Zahoor Aqib , Siddiqui Imran N. , Sener Bilge , Erdemoglu Nurgun 
Published: October 2010

AbstractFrom the aerial parts of Zygophyllum fabago, two new monosodium salts of sulfated derivatives of ursolic acid, along with two known quinovic acid glycosides were isolated. The structures of the new compounds were determined as (3β,4α)‐3,23,30‐trihydroxyurs‐20‐en‐28‐al 3,23‐di(sulfate) sodium salt (1 : 1) (1) and of (3β,4α)‐3,23,28‐trihydroxyurs‐20‐en‐30‐yl β‐D‐glucopyranoside 3,23‐di(sulfate) sodium salt (1 : 1) (2) with the molecular formula C30H47NaO10S2 and C36H59NaO15S2, respectively. The structures of the known compounds were 3‐O‐(2‐O‐sulfo‐β‐D‐quinovopyranosyl)quinovic acid 28‐β‐D‐glucopyranosyl ester (3) and 3‐O‐(β‐D‐glucopyranosyl)quinovic acid 28‐β‐D‐glucopyranosyl ester (4) (quinovic acid=(3β)‐3‐hydroxyurs‐12‐ene‐27,28‐dioic acid). The structures of all these compounds were determined by using 1D‐ and 2D‐NMR spectroscopic techniques.
Stereoselective Total Synthesis of Dodoneine
Authors: Chinnababu Baggu , Reddy Sudina Purushotham , Rao Chitturi Bhujanga , Rajesh Karuturi , Venkateswarlu Yenamandra 
Published: October 2010

AbstractA simple and highly efficient stereoselective total synthesis of dodoneine (1), a naturally occurring bioactive 5,6‐dihydro‐2H‐pyran‐2‐one, was achieved. The synthesis involved Keck's asymmetric allylation, iodine‐induced electrophilic cyclization, and Grubbs' catalyzed ring‐closing metathesis as key steps.
Lewis Acids as Mild and Effective Catalysts for the Synthesis of 3,5‐Bis[(hetero)arylidene]piperidin‐4‐ones
Authors: Leonova Evgeniya , Makarov Mihail , Klemenkova Zinaida , Odinets Irina 
Published: October 2010

AbstractThe aldol‐crotonic condensation reactions of N‐alkyl‐ and NH‐piperidin‐4‐one derivatives with (hetero)aromatic aldehydes promoted by Lewis acids or bases were examined. This comparative study has revealed three effective catalytic systems based on Lewis acids, i.e., LiClO4 and MgBr2 (in the presence of tertiary amine), and BF3⋅Et2O, for the synthesis of N‐alkyl‐substituted 3,5‐bis(heteroarylidene)piperidin‐4‐ones, including those bearing acid‐ or base‐labile groups both in the (hetero)aromatic groups and in the alkyl substituent at the N‐atom. The highest reaction rate was observed for LiClO4‐mediated synthesis. Both MgBr2‐ and LiClO4‐mediated syntheses were inefficient in the case of NH‐piperidin‐4‐one, while BF3⋅Et2O provided the final compounds in high yields. This catalyst is especially advantageous as it allows simultaneous condensation and deprotection in the case of O‐protected piperidin‐4‐one.
A Novel Alkaloid from Melodinus henryi
Authors: Zhou Hua , He Hong‐Ping , Wang Yue‐Hu , Hao Xiao‐Jiang 
Published: October 2010

AbstractThe isolation and structure elucidation of a novel alkaloid, namely of the 14‐O‐ethyl‐substituted (3α,14α,16α)‐2,7‐secoeburnamine derivative 1 from the leaf of Melodinus henryi is reported. Ten known alkaloids were also isolated. Their structures were determined spectroscopically. The isolates were evaluated for their cytotoxicity.
Pubescone, a Novel 11(7→6)Abeo‐14‐norcarabrane Sesquiterpenoid from Siegesbeckia pubescens
Authors: Wang Rui , Liu Lei‐Lei , Shi Yan‐Ping 
Published: October 2010

AbstractThe phytochemical investigation of the aerial parts of Siegesbeckia pubescens L. yielded 16 sesquiterpenoids, including a novel 11(7→6)abeo‐14‐norcarabrane sesquiterpenoid, pubescone (1), and a new germacrane sesquiterpene, 5. The molecular structures of the isolated compounds were elucidated on the basis of extensive spectroscopic analysis, including 1D‐ and 2D‐NMR.
Labdane Diterpenes and Flavonoids from Leonurus japonicus
Authors: Seo Hyun Kyu , Kim Ju Sun , Kang Sam Sik 
Published: October 2010

AbstractChemical investigation of the aerial part of Leonurus japonicus led to the isolation and characterization of a new labdane‐type diterpene, named 3α‐acetoxy‐15‐O‐methylleopersin C (3), and a new acylated rutin derivative, named 2′′′‐syringylrutin (9), along with seven known compounds, including a labdane‐type diterpene and six flavonoids. The structures of the new compounds were established by spectroscopic methods.
The Effect of Fluoro Substitution upon the β‐Hairpin Fold of a β‐Tetrapeptide in Methanol
Authors: Bachmann Stephan , Jaun Bernhard , van Gunsteren Wilfred F. , Wang Dongqi 
Published: October 2010

AbstractThe importance of β‐peptides lies in their ability to mimic the conformational behavior of α‐peptides, even with a much shorter chain length, and in their resistance to proteases. To investigate the effect of substitution of β‐peptides on their dominant fold, we have carried out a molecular‐dynamics (MD) simulation study of two tetrapeptides, Ac‐(2R,3S)‐β2,3hVal(αMe)‐(2S)‐β2hPhe‐(R)‐β3hLys‐(2R,3S)‐β2,3‐Ala(αMe)‐NH2, differing in the substitution at the Cα of Phe2 (pepF with F, and pepH with H). Three simulations, unrestrained (UNRES), using 3J‐coupling biasing with local elevation in combination with either instantaneous (INS) or time‐averaging (AVE) NOE distance restraining, were carried out for each peptide. In the unrestrained simulations, we find three (pepF) and two (pepH) NOE distance bound violations of maximally 0.22 nm that involve the terminal residues. The restrained simulations match both the NOE distance bounds and 3J‐values derived from experiment. The fluorinated peptide shows a slightly larger conformational variability than the non‐fluorinated one.
Zooplankton Density Prediction in a Flood Lake (Pantanal – Brazil) Using Artificial Neural Networks
Authors: Fantin‐Cruz Ibraim , Pedrollo Olavo , Costa Bonecker Cláudia , da Motta‐Marques David , Loverde‐Oliveira Simoni 
Published: October 2010

AbstractEcologic relationships are usually non‐linear and highly complex. For this reason, artificial neural networks (ANN) were selected to model zooplankton density groups in the Coqueiro lake in the northern Pantanal of Brazil. The input layer used 11 limnological variables with 13 neurons in the hidden layer; the output layer consisted of three zooplankton groups. Samples were collected monthly between April 2002 and May 2003, at three different points of the lake, two of which were used for training the ANNs and the other for validation. The ANN model performed well at predicting the density of zooplankton groups (coefficients of determination r2were 0.88, 0.50 and 0.82 for rotifers, cladocerans and copepods, respectively). The comparison between models, and the ANN techniques used, demonstrated that zooplankton densities, observed one month previously, did not influence current densities, which were determined by limnological conditions in the lake. It was also shown that the processes that relate zooplankton to their environment remained stable during the study, while a model sensitivity analysis showed that the density dynamics of zooplankton groups in the Coqueiro lake were strongly influenced by availability of food (phytoplankton and detritus) and by variations in water‐level. It can be concluded from the study that ANNs are a powerful tool both for predicting zooplankton densities and for understanding their relationships with the environment. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Food Web and Trophic Basis of Production of the Benthic Macroinvertebrate Community of a Subtropical Stream (Yangtze River Basin, Middle China)
Authors: Wen Fangni , Jiang Jing , Deng Shan , Li Xiaoyu , Yan Yunjun 
Published: October 2010

AbstractThe food web of the benthic macroinvertebrate community of the Tanqigou Stream – a subtropical forested headwater stream of the Yangtze River basin – was investigated for the first time. The results indicated that the stream was mainly a detritus‐based system, with its functionality being highly dependent on allochthonous input of organic matter. Vascular plant detritus, filamentous algae, diatoms and fungi were also important food resources for the macroinvertebrate community in the stream. Temporal and spatial patterns of ingestion of four mayflies (which were the dominant species) demonstrated that there was little difference in feeding selection, but significant variations in ingestion patterns were observed, during different seasons and at different sampling sites. Nevertheless, the rates of ingestion of the four mayflies were generally stable and independent of the season or the site. The macroinvertebrate food web encompassed five basic food resources; four top predator species, and 27 intermediate non‐predator consumers. The predator‐prey ratio was 0.36; the total number of linkages 152; the trophic connectance 0.16; the maximum chain length three; and the mean chain length 2.21. A quantitative assessment of the energy flux along the major food web pathways indicated that organic matter pathways were mainly formed by weak linkages (36), which accounted for 60.31% of the total linkages (63) and that a few pathways accounted for most of the flow of organic matter. This suggests that Tanqigou Stream is similar to streams that are mainly dependant on detritus‐based‐ and allochthonous‐input of organic matter. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Competitive Influence of Zebra Mussel (Dreissena polymorpha) on Daphnia longispina Population Dynamics in the Presence of Cyanobacteria
Authors: Wojtal‐Frankiewicz Adrianna , Sieczko Anna , Izydorczyk Katarzyna , Jurczak Tomasz , Frankiewicz Piotr 
Published: October 2010

AbstractThe demographic response of Daphnia longispina to the presence of the competitive filter‐feeder zebra mussel (Dreissena polymorpha) was examined in a ten‐day laboratory experiment. The experiment was carried out in five replicates of four treatments corresponding to zooplankton and zebra mussels presence/absence combinations. Our experiment revealed a negative influence of zebra mussels on D. longispina population growth, suggesting low recruitment caused by high mortality at juvenile stages. We observed a smaller loss of phytoplankton biomass in mussel treatments than in the zooplankton treatment. Additionally, the concentration of microcystins was from 3.5 to 4.3 times higher in mussel treatments than in the zooplankton treatment. We also observed that Daphnia excreted significantly more ammonia than zebra mussels but less phosphate. The high amount of phosphate excreted by zebra mussels might have facilitated M. aeruginosa development and resulted in a greater cyanobacteria biomass in the mussel treatments. These results suggest a negative impact of invasive zebra mussels on a keystone filter‐feeding Daphnia spp. and a favourable effect of mussels on M. aeruginosa, by returning them back as pseudoceces, which may be important factors for the management of eutrophic freshwater ecosystems with cyanobacteria blooms. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)