bluuebunny/crossref_metadata_2025_split huggingface dataset:
Free fatty acids as mediators of adaptive compensatory responses to insulin resistance in dexamethasone‐treated rats
Authors: Novelli Michela , Pocai Alessandro , Chiellini Chiara , Maffei Margherita , Masiello Pellegrino 
Published: December 2007

AbstractBackgroundChronic low‐dose dexamethasone (DEX) treatment in rats is associated to insulin resistance with compensatory hyperinsulinaemia and reduction in food intake. We tested the hypothesis that the elevation in circulating free fatty acids (FFAs) induced by DEX is the common mediator of both insulin resistance and insulin hyperproduction.MethodsFor this purpose, an anti‐lipolytic agent was administered during DEX treatment to lower lipacidaemia for several hours prior to glucose and insulin tolerance tests. Leptin expression in adipose tissue (by Northern blot) and plasma leptin levels (by radioimmunoassay) were also investigated to verify whether a rise in circulating leptin could be responsible for the anorectic effect of DEX.ResultsOur data show that a transient pharmacological reduction of elevated plasma FFA levels abates the post‐loading hyperinsulinaemia and counteracts the insulin resistance induced by DEX, supporting the hypothesis that the chronic elevation in FFAs is the common mediator of DEX‐induced changes. Despite enhanced leptin expression in white adipose tissue, DEX‐treated rats show no significant increase in plasma leptin levels. This suggests that the anorectic effect of DEX should be mediated, at least partially, by other factors, possibly related to the influence of concomitantly elevated plasma FFA and insulin levels on the hypothalamic centers regulating feeding.ConclusionsOur results sustain the idea that a prolonged increase in plasma FFA levels plays an important role in the adaptive regulation of glucose and energy homeostasis, not only by potentiating insulin secretion but also by providing a signal of ‘nutrient abundance’ capable of restraining food intake. Copyright © 2007 John Wiley & Sons, Ltd.
A New Chemical Route to Synthesise TM‐Doped (TM = Co, Fe) TiO2 Nanoparticles
Authors: Nunes Manuel R. , Monteiro Olinda C. , Castro Ana L. , Vasconcelos Duarte A. , Silvestre António J. 
Published: December 2007

AbstractSince the discovery of ferromagnetism well above room temperature in the Co‐doped TiO2 system, diluted magnetic semiconductors based on TiO2 doped with transition metals have generated great interest because of their potential use in the development of spintronic devices. The purpose of this paper is to report on a new and swift chemical route to synthesise highly stable anatase single‐phase Co‐ and Fe‐doped TiO2 nanoparticles, with dopant concentrations of up to 10 at.‐% and grain sizes that range between 20 and 30 nm. Complementary structural, microstructural and chemical analyses of the different nanopowders synthesised strongly support the hypothesis that a homogeneous distribution of the dopant element in the substitutional sites of the anatase structure has been achieved. Moreover, UV/Vis diffuse reflectance spectra of powder samples show redshifts to lower energies and decreasing bandgap energies with increasing Co or Fe concentration, which is consistent with n‐type doping of the TiO2 anatase matrix. Films of Co‐doped TiO2 were successfully deposited onto Si (100) substrates by the dip‐coating method, with suspensions of Ti1–xCoxO2 nanoparticles in ethylene glycol.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Structural Characterization of the Core Region of the Lipopolysaccharide from the Haloalkaliphilic Halomonas pantelleriensis: Identification of the Biological O‐Antigen Repeating Unit
Authors: Pieretti Giuseppina , Corsaro Maria Michela , Lanzetta Rosa , Parrilli Michelangelo , Nicolaus Barbara , Gambacorta Agata , Lindner Buko , Holst Otto 
Published: December 2007

AbstractHalomonas pantelleriensis is an extremophile, haloalkaliphilic microorganism that requires strictly aerobic conditions for growth. It is able to optimally grow in media containing 3–15 % (w/v) total salt at a pH value between 9 and 10. To survive in these harsh conditions the extremophiles have developed several strategies that allow the microorganism to thrive. These adaptative strategies probably concern the bacteria outer membrane, which is a barrier regulating the exchange with the environment. In such a context, the lipopolysaccharides (LPSs), which are among the major constituent of the Gram‐negative outer membrane, are thought to contribute to restrictive membrane permeability properties. Previous studies concerning the structure of the O‐chain repeating unit of the lipopolysaccharide from this bacterium showed that it is constituted of a tetrasaccharidic repeating unit containing a high number of acidic monosaccharides. It was hypothesized that the carboxylate groups might serve as a protective buffer for bacterium under the extreme life conditions. To provide insight into the relationship and interactions between the environmental factors and microbial life, the core structure was also characterized. The LPS was hydrolyzed under both mild acid and strong alkaline conditions. This last treatment was the best one to obtain the whole core backbone and to gain information about the phosphates position. Moreover, the strong alkaline treatment product allowed us to identify the linkage between the O‐chain and the core structure. Two core oligosaccharides were found and their structures were determined by FTICR MS and NMR spectroscopy. To the best of our knowledge, this represents the first description of the core structure of a lipopolysaccharide of an extremophile bacterium.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A DFT and AIM Study of the Proline‐Catalyzed Asymmetric Cross‐Aldol Addition of Acetone to Isatins: A Rationalization for the Reversal of Chirality
Authors: Corrêa Rodrigo J. , Garden Simon J. , Angelici Gaetano , Tomasini Claudia 
Published: December 2007

AbstractThe steric and stereoelectronic effects that control the enantioselectivity in the cross‐aldol addition of acetone to isatin catalyzed byL‐proline have been studied by means of DFT and AIM calculations. This reaction results in a reversal of enantioselectivity compared with the corresponding cross‐aldol addition to 4,6‐dibromoisatin and aldehydes. DFT calculations of the cross‐aldol transition states indicate that product formation follows different pathways for the substrates isatin and 4,6‐dibromoisatin. In the case of isatin, theSenantiomer is favoured as a consequence of a stereoelectronic effect that results in a lower‐energy transition state for theSenantiomer relative to theRenantiomer. In contrast, the cross‐aldol addition of acetone to 4,6‐dibromoisatin furnishes the expectedRenantiomer owing to a steric effect of the 4‐bromo substituent which inhibits the formation of theSenantiomer via the stereoelectronically favoured transition state.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Seed surface characters and their systematic significance in the genus Lathyrus (Leguminosae, Papilionoideae, Vicieae)
Authors: Abou‐El‐Enain M. M. , Loufty M. H. A. , Shehata A. A. 
Published: December 2007

AbstractSeed morphology of 34 species of Lathyrus was examined by light‐ (LM) and scanning electron microscopy (SEM). Quantitative and qualitative features were evaluated to identify groups of species using a phenetic analysis. The used characters were that of testa (luster, multicellular sculpture and homogeneity of cell‐size); anticlinal walls (level, undulation, thickness and 2ry sculpture); outer periclinal walls (level and 2ry sculpture); hilum (shape and length/ width ratio) and the seed length/width ratio. Nine multi‐cellular sculptures and three patterns of secondary sculpture of anticlinal walls were recorded. The most common and remarkable pattern was the prominent stellate like structures on the angles of the anticlinal walls. Many terms used for describing patterns should be reevaluated within the whole tribe to better define of the character states for the multicellular sculpture. The present data were useful to recognize species or groups of species by a unique or combination of character states and had supported the retaining of Lathyrus tingitanus and L. tuberosus in section Lathyrus; the placement of L. neurolobus and L. nissolia in two different monotypic sections; the distinctiveness of the species of sections Aphaca and Pratensis. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Examining the statistical properties of fine‐scale mapping in large‐scale association studies
Authors: Wiltshire Steven , Morris Andrew P. , Zeggini Eleftheria 
Published: December 2007

AbstractInterpretation of dense single nucleotide polymorphism (SNP) follow‐up of genome‐wide association or linkage scan signals can be facilitated by establishing expectation for the behaviour of primary mapping signals upon fine‐mapping, under both null and alternative hypotheses. We examined the inferences that can be made regarding the posterior probability of a real genetic effect and considered different disease‐mapping strategies and prior probabilities of association. We investigated the impact of the extent of linkage disequilibrium between the disease SNP and the primary analysis signal and the extent to which the disease gene can be physically localised under these scenarios. We found that large increases in significance (>2 orders of magnitude) appear in the exclusive domain of genuine genetic effects, especially in the follow‐up of genome‐wide association scans or consensus regions from multiple linkage scans. Fine‐mapping significant association signals that reside directly under linkage peaks yield little improvement in an already high posterior probability of a real effect. Following fine‐mapping, those signals that increase in significance also demonstrate improved localisation. We found local linkage disequiliptium patterns around the primary analysis signal(s) and tagging efficacy of typed markers to play an important role in determining a suitable interval for fine‐mapping. Our findings help inform the interpretation and design of dense SNP‐mapping follow‐up studies, thus facilitating discrimination between a genuine genetic effect and chance fluctuation (false positive). Genet. Epidemiol. 2007. © 2007 Wiley‐Liss, Inc.
A double blind, placebo‐controlled pilot study of galantamine augmentation of antidepressant treatment in older adults with major depression
Authors: Holtzheimer Paul E. , Meeks Thomas W. , Kelley Mary E. , Mufti Mustafa , Young Raymond , McWhorter Kimberly , Vito Nancie , Chismar Ronald , Quinn Sinéad , Dey Sherry , Byrd Eve H. , McDonald William M. 
Published: December 2007

AbstractObjectiveDepression in older adults is often associated with cognitive abnormalities and may predict later development of a primary cognitive disorder. This double‐blind, randomized, placebo‐controlled pilot study was designed to assess the safety and efficacy of galantamine augmentation of antidepressant treatment for depressive and cognitive symptoms in older adults with major depression.MethodsThirty‐eight, non‐demented older adults (age >50) with major depression were randomized to receive galantamine or placebo augmentation of standard antidepressant pharmacotherapy (venlafaxine XR or citalopram). Mood and cognitive status were monitored for 24 weeks using the 24‐item Hamilton Rating Scale for Depression and the Repeatable Battery for the Assessment of Neuropsychological Status.ResultsBoth groups showed significant improvements in mood and cognition over 24 weeks, but no significant difference was found in change over time between groups. An exploratory post‐hoc analysis suggested that patients randomized to galantamine had lower depression scores compared to patients in the placebo group after 2 weeks of treatment. Dropout was high with more subjects randomized to antidepressant plus galantamine withdrawing early from the study.ConclusionsThis pilot study failed to demonstrate a benefit for galantamine augmentation of antidepressant medication in the treatment of depression in older adults. Future studies should explore strategies for reducing dropout in such longitudinal trials and more carefully assess time to response with cholinesterase inhibitor augmentation. Copyright © 2007 John Wiley & Sons, Ltd.
An evaluation of spatial thresholding techniques in fMRI analysis
Authors: Logan Brent R. , Geliazkova Maya P. , Rowe Daniel B. 
Published: December 2007

AbstractMany fMRI experiments have a common objective of identifying active voxels in a neuroimaging dataset. This is done in single subject experiments, for example, by performing individual voxel‐wise tests of the null hypothesis that the observed time course is not significantly related to an assigned reference function. A voxel activation map is then constructed by applying a thresholding rule to the resulting statistics (e.g., t‐statistics). Typically the task‐related activation is expected to occur in clusters of voxels rather than in isolated single voxels. A variety of spatial thresholding techniques have been proposed to reflect this belief, including smoothing the raw t‐statistics, cluster size inference, and spatial mixture modeling. We study two aspects of these spatial thresholding procedures applied to single subject fMRI analysis through simulation. First, we examine the performance of these procedures in terms of sensitivity to detect voxel activation, using receiver operating characteristic curves. Second, we consider the accuracy of these spatial thresholding procedures in estimation of the size of the activation region, both in terms of bias and variance. The findings indicate that smoothing has the highest sensitivity to modest magnitude signals, but tend to overestimate the size of the activation region. Spatial mixture models estimate the size of a spatially distributed activation region well, but may be less sensitive to modest magnitude signals, indicating that additional research into more sensitive spatial mixture models is needed. Finally, the methods are illustrated with a real bilateral finger‐tapping fMRI experiment. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Neurofunctional modulation of brain regions by distinct forms of motor cognition and movement features
Authors: Piefke Martina , Kramer Kira , Korte Mia , Schulte‐Rüther Martin , Korte Jan M. , Wohlschläger Afra M. , Weber Jochen , Shah Nadim J. , Huber Walter , Fink Gereon R. 
Published: December 2007

AbstractExtrastriate, parietal, and frontal brain regions are differentially involved in distinct kinds of body movements and motor cognition. Using functional magnetic resonance imaging, we investigated the neural mechanisms underlying the observation and mental imagery of meaningful face and limb movements with or without objects. The supplementary motor area was differentially recruited by the mental imagery of movements while there were differential responses of the extrastriate body area (EBA) during the observation conditions. Contrary to most previous reports, the EBA responded to face movements, albeit to a lesser degree than to limb movements. The medial wall of the intraparietal sulcus and adjacent intraparietal cortex was selectively recruited by the processing of meaningful upper limb movements, irrespective of whether these were object‐related or not. Besides reach and grasp movements, the intraparietal sulcus may thus be involved in limb gesture processing, that is, in an important aspect of human social communication. We conclude that subregions of a frontal–parietal network differentially interact during the cognitive processing of body movements according to the specific motor‐related task at hand and the particular movement features involved. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
Ventral hippocampal involvement in temporal order, but not recognition, memory for spatial information
Authors: Howland John G. , Harrison Rebecca A. , Hannesson Darren K. , Phillips Anthony G. 
Published: December 2007

AbstractThe hippocampus is critical for spatial memory. Recently, subregional differences in the function of hippocampus have been described in a number of behavioral tasks. The present experiments assessed the effects of reversibly lesioning either the dorsal (dHip) or ventral hippocampus (vHip) on spontaneous tests of spatial recognition and temporal order memory. We report that although the dHip is necessary for spatial recognition memory (RM) (distinguishing a novel from a familiar spatial location), the vHip is involved in temporal order memory (the capacity to distinguish between two spatial locations visited at different points in time), but not RM. These findings and others are consistent with the hypothesis that temporal order memory is supported by an integrated circuit of limbic areas including the vHip and the medial prefrontal cortex. © 2007 Wiley‐Liss, Inc.
Low‐cost solution to on‐line color filter array demosaicking
Authors: Kabukcu Gökhan , Yurdakul Arda 
Published: December 2007

AbstractThe article introduces a low‐cost algorithm for improving the demosaicking process in the texture areas such as one‐pixel patterns. The algorithm first detects difficult texture regions. After the detection process is completed, the algorithm demosaicks the texture areas using special demosaicking operations whereas non‐texture regions are restored using some of the existing demosaicking approaches. In this way, the quality of the texture areas in demosaicked images can be improved up to 70% while only little increasing the computational complexity of the original demosaicking solution. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 232–243, 2007
Image texture classification using wavelet based curve fitting and probabilistic neural network
Authors: Ramakrishnan Srinivasan , Selvan Srinivasan 
Published: December 2007

AbstractThis article describes a new approach for image texture classification based on curve fitting of wavelet domain singular values and probabilistic neural networks. Image textures are wavelet packet transformed and singular value decomposition is then employed on subband coefficient matrices after introducing non‐linearity. Lower singular values are truncated based on energy distribution to effectively classify textures in the presence of noise. The selected singular values are fitted to the exponential curve. The model parameters are estimated using population‐sample analogues method and the parameters are used for performing classification. A modified form of probabilistic neural network (PNN) called weighted PNN (WPNN) is employed for performing the classification. Compared to probabilistic neural network, WPNN includes weighting factors between pattern layer and summation layer of the PNN. Performance of the approach is compared with model based and feature based methods in terms of signal to noise ratio and classification rate. Experimental results prove that the proposed approach gives better classification rate under noisy environment. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 266–275, 2007
Note on a Highly Diverse Rotifer Assemblage (Rotifera: Monogononta) in a Laotian Rice Paddy and Adjacent Pond
Authors: Segers Hendrik , Sanoamuang La‐orsri 
Published: December 2007

AbstractDuring August 1999, the authors conducted a sampling campaign in the PDR Laos, in order to contribute to the chorology of rotifers in the region. Two samples, collected from a rice paddy and an adjacent pond near Vientiane, Laos, contained a total of 135 rotifer species including several that appear new to science or that warrant taxonomical or biogeographical comments. No new species can be named, but Cephalodella boettgeri Koste and Floscularia armata Segers are recorded for the second time ever after their description from South America, and Parencentrum lutetiae (Harring and Myers) and Polyarthra luminosa Kutikova are new to Southeast Asia. This raises the number of rotifers recorded from Laos from 9 to 130. The diversity recorded is remarkable, especially when compared with that of similar habitats in the Thai part of the floodplain of River Mekong and its tributaries. Different agricultural practices may account for the difference in species richness. Similar highly diverse rotifer faunas are known to occur in natural, tropical and subtropical floodplain systems only. This accords with the view that rice paddies can be regarded as artificial wetlands or floodplain systems, which, if managed taking biodiversity concerns into account, may have a potential for the conservation of freshwater biodiversity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of Daphnia ‐Associated Infochemicals on the Morphology, Polysaccharides Content and PSII‐Efficiency in Scenedesmus obliquus
Authors: Yang Zhou , Kong Fanxiang , Shi Xiaoli , Xing Peng , Zhang Min 
Published: December 2007

AbstractWe investigated the effects of infochemicals from Daphnia carinata on the morphology, polysaccharides yield and PSII‐efficiency in Scenedesmus obliquus. Infochemicals released from D. carinata induced colony formation in S. obliquus. The contents of soluble extracellular polysaccharides, bounded extracellular polysaccharides, and the total polysaccharides per cell in the induced colonies of S. obliquus increased significantly relative to those of the unicells, which indicated that Daphnia ‐associated infochemicals could also stimulate S. obliquus to increase the synthesis of extracellular polysaccharides. The increased extracellular polysaccharides may play an important role in cementing S. obliquus cells together to form colonies. In addition, no significant differences in growth, the maximal efficiency of PSII photochemistry (Fv/Fm), and the effective quantum yields of PSII (ΦPSII) were detected between unicellular and induced colonial populations, which showed that the cost of induced colony formation was not reflected on these indices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)