bluuebunny/crossref_metadata_2025 huggingface dataset:
ACCELERATING JAVA INTERPRETATION IN LOW-COST EMBEDDED PROCESSORS
Authors: KIM TAEK-KYU , LEE JONG-SUNG , OH HYEONG-CHEOL
Published: September 2010

Hardware interpretation is an attractive choice for implementing the Java virtual machine (JVM) in low-end embedded systems. However, the hardware interpretation of complex bytecodes is so expensive that most low-end embedded systems rely on slow software interpreters in processing complex bytecodes. This paper proposes a low-cost hardware approach for accelerating the interpretation of eight complex bytecodes: four object manipulation and four method invocation bytecodes. The proposed approach occupies 204 LUTs in a Xilinx FPGA and reduces by up to 61.5% the number of instructions executed in running the benchmarks considered in this paper.
IMPROVED CT-MR IMAGE FUSION SCHEME USING DUAL TREE COMPLEX CONTOURLET TRANSFORM BASED ON PCA
Authors: AL-AZZAWI NEMIR , WAN ABDULLAH WAN AHMED K.
Published: September 2010

Medical image fusion has been used to derive useful information from multimodality medical image data. This paper presents a dual-tree complex contourlet transform (DT-CCT) based approach for the fusion of magnetic resonance image (MRI) and computed tomography (CT) image. The objective of the fusion of an MRI and a CT image of the same organ is to obtain a single image containing as much information as possible about that organ for diagnosis. The limitation of directional information of dual-tree complex wavelet (DT-CWT) is rectified in DT-CCT by incorporating directional filter banks (DFB) into the DT-CWT. To improve the fused image quality, we propose a new method for fusion rules based on the principle component analysis (PCA) which depend on frequency component of DT-CCT coefficients (contourlet domain). For low frequency coefficients, PCA method is adopted and for high frequency coefficients, the salient features are picked up based on local energy. The final fusion image is obtained by directly applying inverse dual tree complex contourlet transform (IDT-CCT) to the fused low and high frequency coefficients. The DT-CCT produces images with improved contours and textures, while the property of shift invariance is retained. The experimental results showed that the proposed method produces fixed image with extensive features on multimodality.
MULTI-RESOLUTION TEXTURE ANALYSIS OF MAMMOGRAMS USING NEAREST NEIGHBOR CLASSIFICATION TECHNIQUES
Authors: PRATHIBHA B. N. , SADASIVAM V.
Published: September 2010

Mammograms are the most reliable and cost effective method for showing tissues abnormalities of breast. The proposed method classifies the breast tissues by extracting multi texture properties with multi scale wavelet transformations on regions of interest (ROI). The ability of each texture property in discriminating normal and abnormal ROI is analyzed individually and collectively. The method is tested on 217 mammogram images from the mini-MIAS database. Results indicate that multi-resolution image parametrization becomes inevitable when improvement of classification accuracy in textural domains is required. Further, this paper finds the classification accuracy of the nearest neighbor (NN) classification techniques which exploits the underlying density structure of dataset. The study reveals that the variants of the nearest neighbor classifier perform well individually and they significantly enhance the classification accuracy when combined. Finally, the performance of the proposed statistical classifier is compared with radial basis classifier Support Vector Machines (SVM). The receiver operating characteristic (ROC) curve analysis is used as the performance measure to justify the result. It yields an area under the ROC curve (AZ) of 0.946 for proposed scheme, against 0.924 of SVM.
STATIC STABILITY ANALYSIS OF GRASPING MULTIPLE OBJECTS IN 2D
Authors: YAMADA TAKAYOSHI , YAMANAKA SHUICHI , YAMADA MANABU , FUNAHASHI YASUYUKI , YAMAMOTO HIDEHIKO
Published: September 2010

Human hands perform dexterous and fine manipulation of multiple objects. Multifingered robotic hands also have potential ability executing similar manipulation. This paper analyzes static stability of grasping multiple objects in two dimensions to enhance dexterity of robotic hands. Each finger is replaced with a 2D spring model. Not only frictional contact but also frictionless contact is considered. Grasp stiffness matrices of multiple planar objects are derived with consideration of contact friction property. Grasp stability is evaluated by eigenvalues of the matrices. Configuration (position and orientation) displacement of the objects is decomposed into stable directions and unstable directions by using corresponding eigenvectors. Effectiveness of our proposed method is demonstrated through numerical examples. Our proposed method is applicable to grasp position planning and fixture position planning.
INITIAL STUDY ON A HOME-BASED FLOOR-MAT SYSTEM FOR FALL PREVENTION OF ELDERLY BASED ON GAIT ANALYSIS
Authors: WANG PING , LOW K. H. , TANI JEFFRY WILLIAM , CHANDRA TEGUH
Published: September 2010

Falls can have a fatal effect on elderly, and fall-related injuries are increasing dramatically with age. Studies on risk of fall show that falls are often caused by changes in gait characteristics. Early detections by visiting clinic or hospital contribute to the prevention of falls. However, most of the elderly are not willing to visit clinics or hospitals for health screening. Thus, it will be useful if unobtrusive health screenings were to be brought to their home. Design guidelines for the home-based floor-mat include easy setup, simplicity, low cost, and less intervention of daily life are explained and highlighted. With the proposed daily monitoring system, the changes in gait characteristics, hardly distinguishable by the naked-eye, can be noticed. The reliability of the home-system was also verified with a comparison to Gaitrite. Finally, modeling experiments shows the effectiveness of the monitoring system. In conclusion, a home-based floor-mat system is able to provide daily non-intrusive monitoring.
Geo-engineering along the A55 North Wales Coast Road
Authors: Nichol D
Published: September 2010

The A55 Chester to Holyhead trunk road comprises 145 km of modern dual carriageway along the coast of North Wales. As part of Euroroute E22 (Sassnitz to Dublin) it forms a main artery to the British and European motorway network. Construction (1969–2001) entailed 30 separate schemes crossing diverse geological terrains that posed a wide variety of ground problems of considerable engineering interest. This paper describes the diverse geo-engineering features associated with the project and highlights certain aspects of the design and ground engineering methods used to mitigate or resolve some of the geotechnical concerns along the route. On the easternmost schemes, uneven settlements resulted from kettle holes in till, backfilled opencast coal mining areas and pockets of postglacial peat. At Halkyn Mountain, the construction corridor crossed a zone of abandoned lead-zinc mine workings and through the Clwydian Range it traversed a cluster of sinkholes. On Rhuallt Hill, adverse discontinuity conditions in Silurian siltstones created slope instability in a rock cutting. In the Vale of Clwyd, the till plain provided satisfactory foundation conditions but further west, soft alluvium and peat beneath the coastal plain caused major ground engineering difficulties. The Conwy Crossing was the first immersed-tube road tunnel in the UK and the mountainous headlands of Penmaenbach and Pen-y-Clip, composed of Ordovician igneous rocks, required the construction of hard-rock road tunnels. The westernmost schemes on the mainland traversed Cambrian and Ordovician strata mantled with glacial deposits. The final extension across the island of Anglesey was constructed over schist and gneiss of the Precambrian crystalline basement.
The Fourth Glossop Lecture
Authors: Hutchinson J. N.
Published: September 2010

In this lecture, the process of reading the ground is explored, some of the necessary background is defined and ways of improving our present and future competence in this area are outlined. It acknowledges the world-wide scope of this activity, but employs mainly the narrower canvas of mass movements in NW European conditions to illustrate its nature.

Some basic tools which can assist in this process are first noted, good databases, the techniques of initial site appraisal, comprising desk study, site reconnaissance and mapping (with the aid of stereoscopic air photo interpretation and other remote sensing techniques), terrain modelling and the use of associated well-logged and sampled trial trenches. The importance of the classification of mass movements, not least to develop an agreed terminology, is touched upon and the great value, even at this early stage, of the influence line approach in assessing rapidly the effects of proposed cuts and fills is noted.

An attempt is then made to identify the relevant vocabulary for reading the ground, that is those physical phenomena which bear on site appraisal. These are divided into bedrock elements, of which lithology and tectonics are highlighted, and Quaternary elements, particularly those that occurred in areas of cold climate, i.e. past freezing and thawing, sea-level changes, hydrogeological features and glacial, periglacial, fluvial and marine erosional and depositional features. Abandoned cliffs and inland scarps in chalk and some clays are then identified as characteristic landforms, and their nature and development are also explored. Case records of successful and unsuccessful earthworks on clayey scarps are also reviewed, in relation to the quality of initial site appraisal undertaken.

In conclusion, significant weaknesses in our current education and training in this area are identified, specifically a near-absence of geomorphology and insufficient Quaternary geology, and proposals made to remedy these.
Estimating change in direct groundwater recharge using a spatially distributed soil water balance model
Authors: Finch J. W.
Published: September 2010

There is a requirement to estimate the impact of changes in land cover and climatic parameters on groundwater recharge. A simple, causal, spatially distributed soil water balance model for estimating direct groundwater recharge is described. The potential use of this model is illustrated by the results of a study carried out in a Chalk surface water catchment in southern England. The study estimates the response of mean annual groundwater recharge to land cover changes which took place between 1990 and 1997. It is concluded that, in this case, the change in land cover significantly alters the pattern of recharge but, by coincidence, that the total for the catchment is unchanged.
Physical and chemical properties of a DNAPL contaminated zone in a sand aquifer
Authors: Acworth R. I.
Published: September 2010

Minimally disturbed cores were recovered from two boreholes 25 m apart in the Botany Sands aquifer in Sydney, Australia. Physical and chemical analyses of the core subsections demonstrate that the formation is comprised predominantly of fine to medium sand from the surface to a depth of approximately 21 m. A 200 mm silty sand layer at 21.6 m depth partially supports a DNAPL (dense non-aqueous phase liquid) pool of chlorinated hydrocarbons. DNAPL has penetrated through this zone into the underlying sands. A more extensive sandy silt layer at 23.4 m has prevented further local penetration of the DNAPL. Free phase DNAPL mixture was recovered from a core subsection immediately above the silty sand layer and from several cores in the sand zone above the sandy silt.

A prominent thin high TDS band is associated with the top of the zone containing DNAPL. This zone forms a sharp bulk electrical conductivity anomaly on geoelectric sections compiled from conductivity cone penetration logs and induction logs carried out in the bores after coring. The anomaly is directly related to fluid conductivity variations, which have been measured on pore fluids derived from the cores. The bulk electrical conductivity (complex) measured at a range (10
−2
–10
5
 Hz) of frequencies provides further confirmation of the source of the conductivity anomaly. Lithological detail is provided by grain-size analysis and by radiographs of the cores.

The chemical analysis data carried out on pore fluids indicate that the zones containing free phase DNAPL have low pH (3–4) and sodium to chloride ratios (m mol/l) below 0.20. The inorganic chemical data for 4 cores in the DNAPL contaminated zone is shown graphically and exhibits systematic changes within the section that suggest either strong reverse ion-exchange reactions in an environment where chloride is conservative or, more probably, mineralization of DNAPL.
Geological characterization of weak cataclastic fault rocks with regards to the assessment of their geomechanical properties
Authors: Bürgi C. , Parriaux A. , Franciosi G.
Published: September 2010

A new quantitative method for the characterization of weak cataclastic fault rocks (e.g. fault breccia, gouges) is presented. Applied to find correlations with geomechanical laboratory tests, the thin section and X-ray diffraction analyses used for the method are on a similar scale. The method is shown to be appropriate for the characterization of a large range of different types of weak cataclastic fault rocks (kakirites) and involves appraising their mineralogical composition and microstructural characteristics. The correlation of the geological and geomechanical properties of kakirites based on this approach has shown promising results. The method could provide, in the future, the required geological input data for a mathematical modelling of the geomechanical behaviour of cataclastic fault zones.
Observations on aspects of skid-resistance of greywacke aggregate
Authors: Perry M. J. , Woodside A. R. , Woodward W. D. H.
Published: September 2010

The paper outlines recent investigations concerning the Polished Stone Value (PSV) test method. Although the research is limited to greywacke aggregate from Northern Ireland the results indicate that the standard PSV test may not adequately predict the ultimate level of skid-resistance reached by the aggregates assessed. Extending the duration of polishing further decreases skid-resistance. Modifying the apparatus to simulate cornering situations using angled polishing produced significant reductions in skid-resistance. It was also shown that results may alter when the aggregate size is decreased. The paper concludes that further research is necessary in order to predict the in-service performance of aggregates in the laboratory.
Aquifer properties of the Chalk of England
Authors: MacDonald Alan M. , Allen David J.
Published: September 2010

Aquifer properties data from 2100 pumping tests carried out in the Chalk aquifer have been collated as part of a joint British Geological Survey/Environment Agency project. The dataset is highly biased: most pumping tests have been undertaken in valley areas where the yield of the Chalk is highest. Transmissivity values from measured sites give the appearance of log-normality, but are not truly log-normal. The median of available data is 540 m
2
/d and the 25th and 75th percentiles 190 m
2
/d and 1500 m
2
/d respectively. Estimates of storage coefficient from unconfined tests have a median of 0.008 and from confined tests, 0.0006.

The data indicate several trends and relationships in Chalk aquifer properties. Transmissivity is highest in the harder Chalk of Yorkshire and Lincolnshire (median 1800 m
2
/d). Throughout much of the Chalk aquifer a direct relation is observed between transmissivity and storage coefficient, reflecting the importance of fractures in governing both storage and transmissivity. Pumping tests undertaken in unconfined conditions give consistently higher measurements of transmissivity than in confined areas, probably as a result of increased dissolution enhancement of fractures in unconfined areas. At a catchment scale the data illustrate a relation between transmissivity and winter flowing streams.
Water quality impacts and palaeohydrogeology in the Yorkshire Chalk aquifer, UK
Authors: Elliot Trevor , Chadha Darminder S. , Younger Paul L.
Published: September 2010

A large hydrochemical data-set for the East Yorkshire Chalk aquifer has been assessed. Controls on the distribution of water qualities reflect: water-rock interactions (affecting especially the carbonate system and associated geochemistry); effects of land-use change (especially where the aquifer is unconfined); saline intrusion and aquifer refreshening (including ion exchange effects); and overexploitation (in the semi-confined and confined zones of the aquifer). Both Sr and I prove useful indicators of groundwater esidence times, and I/Cl ratios characterize two sources of saline waters. The hydrochemical evidence clearly reveals the importance both of recent management decisions and palaeohydrogeology in determining the evolution and distribution of groundwater salinity within the artesian and confined zones of the aquifer. Waters encountered in the aquifer are identified as complex (and potentially dynamic) mixtures between recent recharge waters, modern seawater, and ancient seawater which entered the aquifer many millennia ago.
SGLT1 protein expression in plasma membrane of acinar cells correlates with the sympathetic outflow to salivary glands in diabetic and hypertensive rats
Authors: Sabino-Silva Robinson , Alves-Wagner Ana B. T. , Burgi Katia , Okamoto Maristela M. , Alves Adilson S. , Lima Guilherme A. , Freitas Helayne S. , Antunes Vagner R. , Machado Ubiratan F.
Published: September 2010

Salivary gland dysfunction is a feature in diabetes and hypertension. We hypothesized that sodium-glucose cotransporter 1 (SGLT1) participates in salivary dysfunctions through a sympathetic- and protein kinase A (PKA)-mediated pathway. In Wistar-Kyoto (WKY), diabetic WKY (WKY-D), spontaneously hypertensive (SHR), and diabetic SHR (SHR-D) rats, PKA/SGLT1 proteins were analyzed in parotid and submandibular glands, and the sympathetic nerve activity (SNA) to the glands was monitored. Basal SNA was threefold higher in SHR ( P < 0.001 vs. WKY), and diabetes decreased this activity (∼50%, P < 0.05) in both WKY and SHR. The catalytic subunit of PKA and the plasma membrane SGLT1 content in acinar cells were regulated in parallel to the SNA. Electrical stimulation of the sympathetic branch to salivary glands increased (∼30%, P < 0.05) PKA and SGLT1 expression. Immunohistochemical analysis confirmed the observed regulations of SGLT1, revealing its location in basolateral membrane of acinar cells. Taken together, our results show highly coordinated regulation of sympathetic activity upon PKA activity and plasma membrane SGLT1 content in salivary glands. Furthermore, the present findings show that diabetic- and/or hypertensive-induced changes in the sympathetic activity correlate with changes in SGLT1 expression in basolateral membrane of acinar cells, which can participate in the salivary glands dysfunctions reported by patients with these pathologies.
Predicting the Timing of Spikes Evoked by Tactile Stimulation of the Hand
Authors: Kim Sung Soo , Sripati Arun P. , Bensmaia Sliman J.
Published: September 2010

What does the hand tell the brain? Tactile stimulation of the hand evokes remarkably precise patterns of neural activity, suggesting that the timing of individual spikes may convey information. However, many aspects of the transformation of mechanical deformations of the skin into spike trains remain unknown. Here we describe an integrate-and-fire model that accurately predicts the timing of individual spikes evoked by arbitrary mechanical vibrations in three types of mechanoreceptive afferent fibers that innervate the hand. The model accounts for most known properties of the three fiber types, including rectification, frequency-sensitivity, and patterns of spike entrainment as a function of stimulus frequency. These results not only shed light on the mechanisms of mechanotransduction but can be used to provide realistic tactile feedback in upper-limb neuroprostheses.
High Resolution Electroencephalography in Freely Moving Mice
Authors: Choi Jee Hyun , Koch Klaus Peter , Poppendieck Wigand , Lee Mina , Shin Hee-Sup
Published: September 2010

Electroencephalography (EEG) is a standard tool for monitoring brain states in humans. Understanding the molecular and cellular mechanisms underlying diverse EEG rhythms can be facilitated by using mouse models under molecular, pharmacological, or electrophysiological manipulations. The small size of the mouse brain, however, poses a severe limitation in the spatial information of EEG. To overcome this limitation, we devised a polyimide based microelectrode array (PBM array) with nanofabrication technologies. The microelectrode contains 32 electrodes, weighs 150 mg, and yields noise-insensitive signals when applied on the mouse skull. The high-density microelectrode allowed both global and focused mapping of high resolution EEG (HR-EEG) in the mouse brain. Mapping and dynamical analysis tools also have been developed to visualize the dynamical changes of spatially resolved mouse EEG. We demonstrated the validity and utility of mouse EEG in localization of the seizure onset in absence seizure model and phase dynamics of abnormal theta rhythm in transgenic mice. Dynamic tracking of the EEG map in genetically modified mice under freely moving conditions should allow study of the molecular and cellular mechanisms underlying the generation and dynamics of diverse EEG rhythms.
An Active Role for Astrocytes in Synaptic Plasticity?
Authors: Wenker Ian
Published: September 2010

Recently, Henneberger and colleagues blocked hippocampal long-term synaptic potentiation (LTP) induction by “clamping” intracellular calcium concentration of individual CA1 astrocytes, suggesting calcium-dependent gliotransmitter release from astocytes plays a role in hippocampal LTP induction. However, using transgenic mice to manipulate astrocytic calcium, Agulhon and colleagues demonstrated no effect on LTP induction. Until the question of how intracellular calcium causes gliotransmitter release is answered, the role of astrocytes in synaptic plasticity will be incompletely understood.
Interacting Noise Sources Shape Patterns of Arm Movement Variability in Three-Dimensional Space
Authors: Apker Gregory A. , Darling Timothy K. , Buneo Christopher A.
Published: September 2010

Reaching movements are subject to noise in both the planning and execution phases of movement production. The interaction of these noise sources during natural movements is not well understood, despite its importance for understanding movement variability in neurologically intact and impaired individuals. Here we examined the interaction of planning and execution related noise during the production of unconstrained reaching movements. Subjects performed sequences of two movements to targets arranged in three vertical planes separated in depth. The starting position for each sequence was also varied in depth with the target plane; thus required movement sequences were largely contained within the vertical plane of the targets. Each final target in a sequence was approached from two different directions, and these movements were made with or without visual feedback of the moving hand. These combined aspects of the design allowed us to probe the interaction of execution and planning related noise with respect to reach endpoint variability. In agreement with previous studies, we found that reach endpoint distributions were highly anisotropic. The principal axes of movement variability were largely aligned with the depth axis, i.e., the axis along which visual planning related noise would be expected to dominate, and were not generally well aligned with the direction of the movement vector. Our results suggest that visual planning–related noise plays a dominant role in determining anisotropic patterns of endpoint variability in three-dimensional space, with execution noise adding to this variability in a movement direction-dependent manner.
Spatial Updating in Monkey Superior Colliculus in the Absence of the Forebrain Commissures: Dissociation Between Superficial and Intermediate Layers
Authors: Dunn Catherine A. , Hall Nathan J. , Colby Carol L.
Published: September 2010

In previous studies, we demonstrated that the forebrain commissures are the primary pathway for remapping from one hemifield to the other. Nonetheless, remapping in lateral intraparietal cortex (LIP) across hemifield is still present in split brain monkeys. This finding indicates that a subcortical structure must contribute to remapping. The primary goal of the current study was to characterize remapping activity in the superior colliculus in intact and split brain monkeys. We recorded neurons in both the superficial and intermediate layers of the SC. We found that across-hemifield remapping was reduced in magnitude and delayed compared with within-hemifield remapping in the intermediate layers of the SC in split brain monkeys. These results mirror our previous findings in area LIP. In contrast, we found no difference in the magnitude or latency for within- compared with across-hemifield remapping in the superficial layers. At the behavioral level, we compared the performance of the monkeys on two conditions of a double-step task. When the second target remained within a single hemifield, performance remained accurate. When the second target had to be updated across hemifields, the split brain monkeys' performance was impaired. Remapping activity in the intermediate layers was correlated with the accuracy and latency of the second saccade during the across-hemifield trials. Remapping in the superficial layers was correlated with latency of the second saccade during the within- and across-hemifield trials. The differences between the layers suggest that different circuits underlie remapping in the superficial and intermediate layers of the superior colliculus.
Nonvisual Motor Learning Improves Visual Motion Perception: Evidence From Violating the Two-Thirds Power Law
Authors: Beets I.A.M. , Rösler F. , Fiehler K.
Published: September 2010

Few studies have reported direct effects of motor learning on visual perception, especially when using novel movements for the motor system. Atypical motor behaviors that violate movement constraints provide an excellent opportunity to study action-to-perception transfer. In our study, we passively trained blindfolded participants on movements violating the 2/3 power law. Before and after motor training, participants performed a visual discrimination task in which they decided whether two consecutive movements were same or different. For motor training, we randomly assigned the participants to two motor training groups or a control group. The motor training group experienced either a weak or a strong elliptic velocity profile on a circular trajectory that matched one of the visual test stimuli. The control group was presented with linear trajectories unrelated to the viewed movements. After each training session, participants actively reproduced the movement to assess motor learning. The group trained on the strong elliptic velocity profile reproduced movements with increasing elliptic velocity profiles while circular geometry remained constant. Furthermore, both training groups improved in visual discrimination ability for the learned movement as well as for highly similar movements. Participants in the control group, however, did not show any improvements in the visual discrimination task nor did participants who did not acquire the trained movement. The present results provide evidence for a transfer from action to perception which generalizes to highly related movements and depends on the success of motor learning. Moreover, under specific conditions, it seems to be possible to acquire movements deviating from the 2/3 power law.
Expression of microRNAs and their target mRNAs in human stem cell-derived cardiomyocyte clusters and in heart tissue
Authors: Synnergren Jane , Améen Caroline , Lindahl Anders , Olsson Björn , Sartipy Peter
Published: September 2010

Recent studies have shown that microRNAs (miRNAs) act as posttranscriptional regulators and that they play important roles during heart development and in cardiac function. Thus, they may provide new means of altering stem cell fate and differentiation processes. However, information about the correlation between global miRNA and mRNA expression in cardiomyocyte clusters (CMCs) derived from human embryonic stem cells (hESC) and in fetal and adult heart tissue is lacking. In the present study the global miRNA and mRNA expression in hESC-derived CMCs and in fetal and adult heart tissue was investigated in parallel using microarrays. Target genes for the differentially expressed miRNAs were predicted using computational methods, and the concordance in miRNA expression and mRNA levels of potential target genes was determined across the experimental samples. The biology of the predicted target genes was further explored regarding their molecular functions and involvement in known regulatory pathways. A clear correlation between the global miRNA expression and corresponding target mRNA expression was observed. Using three different sources of cardiac tissue-like samples, we defined the similarities between in vitro hESC-derived CMCs and their in vivo counterparts. The results are in line with previously reported observations that miRNAs repress mRNA expression and additionally identify a number of novel miRNAs with potential important roles in human cardiac tissue. The concordant miRNA expression pattern observed among all the cardiac tissue-like samples analyzed here provide a starting point for future ambitious studies aiming towards assessment of the functional roles of specific miRNAs during cardiomyocyte differentiation.
Vascular responses in aortic rings of a consomic rat panel derived from the Fawn Hooded Hypertensive strain
Authors: Kunert Mary Pat , Dwinell Melinda R. , Lombard Julian H.
Published: September 2010

The present experiments, utilizing the high-throughput vascular protocol of PhysGen (Program for Genomic Applications) characterized the responses of aortic rings to vasoconstrictor (phenylephrine) and vasodilator (acetylcholine, sodium nitroprusside, and reduced tissue bath Po2) stimuli in consomic rat strains derived from a cross between the Fawn Hooded Hypertensive rat (FHH/EurMcwi) and the Brown Norway normotensive (BN/NHsdMcwi) rat. The effects of substituting individual BN chromosomes into the FHH genetic background were determined in animals that were maintained on a low-salt (0.4% NaCl) diet or switched to a high-salt (4% NaCl) diet for 3 wk. Sex-specific differences were evaluated in male and female consomic rats on similar dietary salt intake. Multiple chromosomes affected various vascular reactivity phenotypes in the FHH × BN consomic panel, and substantial salt-dependent changes in vascular reactivity and sex-specific differences in aortic reactivity were observed in individual consomic strains. However, compared with earlier studies of consomic rats derived from a cross between the BN rat and the Dahl salt-sensitive (SS) rat, only 3–7% of the vascular phenotypes were affected in a similar manner by substituting specific BN chromosomeschromosomes into the FHH genetic background versus the SS genetic background. The findings of the present study stress the potential value of consomic rat panels in gaining insight into genetic factors influencing vascular reactivity and suggest that the chromosomes that appear to be involved in the determination of aortic ring reactivity in different rodent models of hypertension are highly strain- and sex specific.
Synthesis and characterization of micron-size pyrite crystals
Authors: Wu Rong , Jian Ji-kang , Tao Le-tian , Bian Yan-long , Li Jin , Sun Yan-fei , Wang Jun , Zeng Xing-Yan
Published: September 2010

Mixed solvent of ethanol and water using FeSO4⋅7H2O and (NH2)2CS as precursors with polyvinylpyrrolidone as surfactant was used to synthesize cubic FeS2(pyrite) crystals. Crystalline phase and surface morphologies of the crystals were characterized by X-ray diffraction and scanning electron microscopy, respectively. Volume ratio of solvent, reaction temperature, reaction time, and sulfur source were found to be the key parameters for the formation of pure pyrite crystals. Optimal micron-size pyrite crystals were successfully grown from a mixed solvent of ethanol and water with a volume ratio of 3:2, heated to a reaction temperature of 180 °C, and maintained for 36 h with thiourea as the sulfur source.
X-ray diffraction data and Rietveld refinement of CuGaxIn1-xSe2 (x=0.15 and 0.50)
Authors: Friedrich E. J. , Fernández-Ruiz R. , Merino J. M. , León M.
Published: September 2010

X-ray powder diffraction data for CuGa0.15In0.85Se2 and CuGa0.50In0.50Se2 are reported. Indexing of the X-ray diffraction powder pattern and the Rietveld refinement confirmed that these compounds crystallize in the tetragonal crystal system, with space group I-42d (No. 122) and lattice parameters of a=5.7528(2) Å and c=11.5225(3) Å for CuGa0.15In0.85Se2 and a=5.6847(1) Å and c=11.2817(1) Å for CuGa0.50In0.50Se2. The CuGaxIn1−xSe2 system presents the chalcopyrite type crystal structure (CuFeS2) and corresponds to two stacked zinc-blende unit cells. The metal atoms Cu, In, and Ga are regularly ordered in the unit cell. Every Se atom is tetrahedrally bonded to two Cu and two In and Ga atoms.
Crystal structures of carbonates Cs2Sr2(CO3)3 and Rb2Sr2(CO3)3 from powder data
Authors: Jin S. F. , Li M. , Guo J. G. , Wang W. Y. , Xu Y. P. , Chen X. L.
Published: September 2010

Two carbonates Cs2Sr2(CO3)3 and Rb2Sr2(CO3)3 were synthesized by solid-state reaction at high temperatures, and their crystal structures were determined from X-ray powder diffraction data. Because of the presence of heavy atoms and heavy peak overlapping, proper restrains on light-atom groups were found essential to obtain satisfactory results. The title compounds are isostructural to an early reported compound Cs2Ba2(CO3)3 and crystallize in cubic space group I213, with unit-cell dimensions a=10.072 64(2) Å for the cesium phase and a=9.855 56(7) Å for the rubidium phase. Unlike most carbonates, the title compounds feature in mutually perpendicular CO3 atomic groups. Our results also indicate that the global instability index is a more sensitive parameter in evaluating the structure rationality over the agreement factors. Moreover, differential thermal analysis and thermogravimetric analysis measurements reveal that Cs2Sr2(CO3)3 and Rb2Sr2(CO3)3 are stable in air up to 796 and 880 °C, respectively.
Structural study of nonlinear optical borates K1−xNaxSr4(BO3)3 (x≤0.5)
Authors: Wu L. , Zhang Y. , Su W. W. , Kong Y. F. , Xu J. J.
Published: September 2010

X-ray powder diffraction was used for the structural study of nonlinear optical borates K1−xNaxSr4(BO3)3 (x≤0.5). Results show that up to 50% K+ can be substituted by Na+ in orthorhombic K1−xNaxSr4(BO3)3. Isolated BO3 triangles in the Na-substituted compound constrict to adjust to a local distribution of alkali-metal atoms, which explains the large range of structural homogeneity. An expansion of the c axis in a unit cell with increasing Na substitution was found probably caused by the tilted BO3 triangles and asymmetric distortion of (K/Na)O8 polyhedra. As the ratio of ionic radii of alkaline-earth and alkali-metal cations decreases and the electronegative difference between alkaline-earth and alkali-metal cations increases, the crystal system of MM′4(BO3)3 borates changes from cubic to orthorhombic and then to monoclinic.
Crystal structure and diffraction data for a polymorph of voglibose (C10H21NO7)
Authors: Zhang G. Q. , Lv G. L.
Published: September 2010

X-ray powder diffraction data of voglibose are reported, and its crystal and molecular structures were determined by simulated annealing and rigid-body Rietveld refinement methods. Voglibose was found to be crystallized in triclinic symmetry with space group P-1. The lattice parameters were determined to be a=6.1974(6) Å, b=6.9918(5) Å, c=7.3955(9) Å, α=70.8628(3), β=103.5312(4), γ=94.3867(5)°, V=294.2(2) Å3, and ρcal=1.495 g/cm3. The crystal structure contains isolated C10H21NO7 molecular.
Structural investigation of tungsten oxide nanowires by X-ray diffraction and transmission electron microscopy
Authors: Sun Shibin , Sun Suyuan , Li Zhenjiang
Published: September 2010

X-ray diffraction, selected area electron diffraction, and high-resolution transmission electron microscope techniques were used to investigate the crystalline structures of one-dimensional tungsten oxide nanowires prepared by the hydrothermal method. The as-synthesized products were found to exhibit increasing crystallinity with increasing reaction time, and tungsten oxide nanowires have crystalline defects, including stacking faults, dislocations, and vacancies. The results on the crystal defects help us to obtain a better understanding of the temperature-dependent morphological evolution of the ultrathin nanowires synthesized under different thermal processes.
Microstructural characterization of the Portevin–Le Chatelier band in an Al-Mg alloy by X-ray diffraction line profile analysis
Authors: Sarkar A. , Mukherjee P. , Barat P.
Published: September 2010

Al–2.5% Mg alloy exhibits the Portevin–Le Chatelier (PLC) effect at room temperature for a wide range of strain rates. Tensile test has been carried out on a flat Al–2.5% Mg alloy sample at a strain rate of 3.7×10−6 s−1. The strain rate was chosen so that the type C PLC band appears in the sample. X-ray diffraction profile has been recorded from the gauge length portion of the deformed sample to investigate the microstructure of the PLC band. Analysis revealed that the dislocation density is much higher within the band compared to the undeformed sample even at small strain. The PLC band in this alloy possesses an equal fraction of screw and edge dislocations.
Synthesis and crystal structure of double-perovskite compound Sr2FeMoO6
Authors: Hu Y. C. , Ge J. J. , Ji Q. , Lv B. , Wu X. S. , Cheng G. F.
Published: September 2010

Samples of single-phase Sr2FeMoO6 were successfully prepared by solid-state reaction with long sintering times. The crystal structures of the Sr2FeMoO6 samples were determined from X-ray powder diffraction data using the Rietveld refinement method. The structure results obtained by the Rietveld refinements show that an increase in the total sintering time of the solid-state reaction is an effective method to obtain single Sr2FeMoO6 phase and to improve the ordering of Fe and Mo cations (or reducing antisite defects) in the double-perovskite structure. The volume of the tetragonal unit cell of Sr2FeMoO6 contracts slightly after successive sintering treatments. The averaged Fe-O and Mo-O bond lengths as well as the tilt between the FeO6 and the MoO6 octahedra decrease with increasing total sintering time. Our results suggest that the detected subtle changes in crystal structure, such as bond lengths and bond angles between the Fe and Mo cations and oxygen, in the ordered double-perovskite structure may be responsible for the large effects on previously reported transport and magnetic properties of an oxide metal.
X-ray powder diffraction investigations of Ruthenian-Byzantine frescoes from the royal Wawel Cathedral (Poland)
Authors: Rafalska-Lasocha Alicja , Lasocha Wieslaw , Grzesiak Marta , Dziembaj Roman
Published: September 2010

Laboratory X-ray powder diffraction was applied to investigate the pigments used by medieval artists in Ruthenian-Byzantine frescoes in the royal Wawel Cathedral in Krakow (Poland). It was found that red fragments contained cinnabar (PDF 06-0256), yellow contained goethite (PDF 29-0713), and blue pieces contained azurite (PDF 02-0153). The green pigment, quite difficult to identify, was finally established as green earths—pigments commonly used in Byzantine wall paintings. Calcite (PDF 24-0027) was detected in all the samples. Small amounts of quartz (PDF 46-1045) in the plaster samples were also detected. The absence or presence of only minute amounts of quartz is a characteristic feature of the Ruthenian-Byzantine frescoes. Malachite was not detected in the green parts of the frescoes, in contrast to earlier investigations of wall paintings in Poland. Experimental details and the results obtained in this study are described and discussed.
X-ray diffraction study on YBa2Cu3O7−δ with BaCuO2 addition
Authors: Xu Sheng , Wu Xiaoshan , Gu Yanni
Published: September 2010

Two-phase polycrystalline powder mixtures of YBa2Cu3O7−δ (YBCO) and xBaCuO2 (x=0, 0.05, 0.1, 0.2, and 0.3) were prepared by solid reaction. The Rietveld refinements of X-ray powder diffraction data show that BaCuO2 addition was successfully produced in superconductor YBCO and the unit-cell parameters of YBCO reach a maximum at x=0.05. The critical current density (Jc) also reaches a maximum at x=0.05 and then decreases sharply with increasing amount of BaCuO2. The change of Jc as a function of x was found to be similar to those of the unit-cell parameters. The characteristic behavior of Jc may come from the structure-parameter change of YBCO caused by BaCuO2 addition.
Compositional study of prehistoric pigments (Carriqueo rock shelter, Argentina) by synchrotron radiation X-ray diffraction
Authors: Vázquez Cristina , Palacios Oscar Martín , Darchuk Larysa , Marcó Parra Lué-Merú
Published: September 2010

In this work synchrotron radiation X-ray diffraction technique was successfully applied for the analysis of pigments found in excavation at Carriqueo rock shelter, Neuquén, Argentina. The pigment samples of orange, red, and brown shades were collected from different levels of this archaeological site and compared with a suspected source of provenance (La Oficina creek). X-ray diffraction patterns of several yellowish, reddish, and red pigments showed the presence of haematite, goethite, kaolinite, and quartz. The majority of Carriqueo collected samples belonged to the same group of the suspected source, having haematite and quartz as main crystalline phases. The results indicate that the raw material from La Oficina is the source of most of the pigments found at Carriqueo. The present work helps us to understand the strategy of supplying raw materials by human groups in the North Patagonia region.
Synthesis and crystal structure of Co2(OH)2CO3 by Rietveld method
Authors: Wang Shunli , Lü Guanglie , Tang Weihua
Published: September 2010

A new cobalt hydroxide carbonate Co2(OH)2CO3 was successfully synthesized by a hydrothermal method. The compound is isomorphous with malachite [Cu2(OH)2CO3] and crystallizes in a monoclinic system [space group P21/a (No. 14); a=9.448(5) Å, b=12.186(9) Å, c=3.188(4) Å, β=98.593°, V=367.143(9) Å3, Z=4, and Dc=3.786(9) g/cm3]. Crystal structure of Co2(OH)2CO3 was refined by the Rietveld method with RP=4.3%, RWP=5.7%, Rexp=5.1%, RB=1.74%, and S=1.117 on the basis of the X-ray powder diffraction data. The crystal structure of Co2(OH)2CO3 obtained by the Rietveld refinement shows that all species Co2+, CO32−, and OH− ions occupy C1 site symmetry. Two crystallographically different Co2+ and OH− ions and one type CO32− ion exist in the lattice. Co(1) is coordinated to two oxygen atoms from CO32− ions and two OH− ions; Co(2) is coordinated to two oxygen atoms from CO32− ions and four OH− ions, thus forming a distorted octahedron with (4+2) coordination.
PPARs in Rhythmic Metabolic Regulation and Implications in Health and Disease
Authors: Charoensuksai Purin , Xu Wei
Published: September 2010

The circadian rhythm, controlled by a complex network of cellular transcription factors, orchestrates behavior and physiology in the vast majority of animals. The circadian system is comprised of a master clock located in central nervous system with 24-hour rotation and periphery clocks to ensure optimal timing of physiology in peripheral tissues. Circadian expression of peroxisome proliferator-activated receptors (PPARs), members of the nuclear receptor superfamily and key mediators of energy homeostasis and metabolism, is regulated by clock genes. PPARs serve as sensors of nutrient and energy/metabolism status to temporally entrain peripheral clock. Metabolism and circadian clocks are tightly intertwined: clock genes drive metabolism, and various metabolic parameters affect clock genes, producing a reciprocal feedback relationship. Due to PPARs' robust relationship with energy status and metabolism, the aberration of PPARs in the biological clock system leads to abnormal expression of genes in metabolic pathways, thus, contributing to etiology of metabolic syndrome. Studying PPARs' functions under the context of the mammalian circadian system could advance our understanding of how energy and metabolic status are maintained in the body, which may ultimately lead to rhythmic medical treatment against metabolic syndrome.
Ablation Resolution in Laser Corneal Refractive Surgery: The Dual Fluence Concept of the AMARIS Platform
Authors: Arba-Mosquera Samuel , Hollerbach Thomas
Published: September 2010

Purpose. To evaluate to which extent individual Zernike terms can be corrected. Methods. Ablation time and fidelity was analysed using different fluence levels (range 90–2000 mJ/) and aspheric ablation profiles. With optimal parameters, the extent to which individual Zernike modes can be corrected was evaluated.Results. The range 188–565 mJ/ resulted as optimum fluence level with an optimum proportion range 50%–90% for high fluence. With optimal parameters, it corresponds to 2.4 s/D at 6 mm OZ, with fidelity variance of 53 m RMS, and average ablation error of 0.5 m for each location. Ablation simulation of coma Z[3,1] showed 98,4% accuracy and 98% fit quality; trefoil Z[3,3], 99,9% accuracy and 98% fit quality; spherical aberration Z[4,0], 96,6% accuracy and 97% fit quality; secondary astigmatism Z[4,2], 97,9% accuracy and 98% fit quality. Real ablation on a flat plate of PMMA of coma Z[3,1] showed 96,7% accuracy and 96% fit quality; trefoil Z[3,3], 97,1% accuracy and 96% fit quality; spherical aberration Z[4,0], with 93,9% accuracy and 90% fit quality; secondary astigmatism Z[4,2], with 96,0% accuracy and 96% fit quality.Conclusions. Ablation of aspherical and customised shapes based upon Zernike polynomials up to the the 8th order seems accurate using the dual fluence concept implemented at the AMARIS platform.
Treatment of Bacterial Vaginosis: A Multicenter, Double-Blind, Double-Dummy, Randomised Phase III Study Comparing Secnidazole and Metronidazole
Authors: Bohbot Jean-Marc , Vicaut Eric , Fagnen Didier , Brauman Michel
Published: September 2010

Objective. Multiple-dose metronidazole oral therapy is currently the reference treatment for bacterial vaginosis (BV). This double-blind, double-dummy, noninferiority study compared the efficacy of secnidazole, another nitroimidazole with pharmacokinetics allowing a single dose regimen, to this standard treatment.Methods. A total of 577 patients were randomized to receive metronidazole (500 mg, b.i.d for seven days) or secnidazole (2 g, once). Therapeutic cure at D28 was defined as the resolution of vaginal discharge, positive KOH whiff test, vaginal pH>4.5and Nugent score>7on Gram-stained vaginal fluid.Results. According to this primary endpoint, the single-dose secnidazole regimen was shown to be at least as effective as the multiple-dose metronidazole regimen (60.1% cured women vs59.5% , 95% confidence interval with a noninferiority margin of 10%:[−0.082;0.0094]). Safety profiles were comparable in both groups.Conclusion. The secnidazole regimen studied represents an effective, convenient therapeutic alternative that clinicians should consider in routine practice.