bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasticity of illusory vowel perception in Brazilian-Japanese bilinguals
Authors: Parlato-Oliveira Erika , Christophe Anne , Hirose Yuki , Dupoux Emmanuel
Published: June 2010

Previous research shows that monolingual Japanese and Brazilian Portuguese listeners perceive illusory vowels (/u/ and /i/, respectively) within illegal sequences of consonants. Here, several populations of Japanese-Brazilian bilinguals are tested, using an explicit vowel identification task (experiment 1), and an implicit categorization and sequence recall task (experiment 2). Overall, second-generation immigrants, who first acquired Japanese at home and Brazilian during childhood (after age 4) showed a typical Brazilian pattern of result (and so did simultaneous bilinguals, who were exposed to both languages from birth on). In contrast, late bilinguals, who acquired their second language in adulthood, exhibited a pattern corresponding to their native language. In addition, an influence of the second language was observed in the explicit task of Exp. 1, but not in the implicit task used in Exp. 2, suggesting that second language experience affects mostly explicit or metalinguistic skills. These results are compared to other studies of phonological representations in adopted children or immigrants, and discussed in relation to the role of age of acquisition and sociolinguistic factors.
Dialect experience in Vietnamese tone perception
Authors: Kirby James
Published: June 2010

This study investigated the perceptual dimensions of tone in Vietnamese and the effect of dialect experience on listener’s prelinguistic perception of tone. While Northern Vietnamese tones are cued by a combination of pitch and voice quality, Southern Vietnamese tones are purely pitch based. 30 listeners from two Vietnamese dialects (10 Northern, 20 Southern) participated in a speeded AX discrimination task using northern stimuli. The resulting reaction times were used to compute an INDSCAL multidimensional scaling solution and were submitted to hierarchical clustering analysis. While the analysis revealed a similar three-dimensional perceptual space structure for both listener groups, corresponding roughly to f0 offset, voice quality, and contour type, the relative salience of these dimensions varied by dialect: Southern listeners were more likely to confuse tones produced with nonmodal voice quality, whereas Northern listeners found tones with similar pitch excursions to be more confusable. The results of hierarchical clustering of the stimuli further support an analysis where low-level perceptual similarity is influenced by primary dialect experience.
Dispersion and attenuation due to scattering from heterogeneities of the frame bulk modulus of a poroelastic medium
Authors: Hefner Brian T. , Jackson Darrell R.
Published: June 2010

While Biot theory can successfully account for the dispersion observed in sand sediments, the attenuation at high frequencies has been observed to increase more rapidly than Biot theory would predict. In an effort to account for this additional loss, perturbation theory is applied to Biot’s poroelastic equations to model the loss due to the scattering of energy from heterogeneities in the sediment. A general theory for propagation loss is developed and applied to a medium with a randomly varying frame bulk modulus. The theory predicts that these heterogeneities produce an overall softening of the medium as well as scattering of energy from the mean fast compressional wave into incoherent fast and slow compressional waves. This theory is applied to two poroelastic media: a weakly consolidated sand sediment and a consolidated sintered glass bead pack. The random variations in the frame modulus do not have significant effects on the propagation through the sand sediment but do play an important role in the propagation through the consolidated medium.
Spectral profile cues in comodulation masking release
Authors: Buss Emily
Published: June 2010

Previous work on spectral shape discrimination has shown that detection of a level increment in one tone of a tonal complex is dependent on spectral position, with thresholds forming a “bowl” pattern for components spanning 200 to 5000 Hz [Green, D. M., (1988). Profile Analysis: Auditory Intensity Discrimination (Oxford University Press, New York)]. The current study examined whether a similar bowl occurs for comodulation masking release, a paradigm in which dynamic spectral cues could be used to detect an added signal. Maskers were logarithmically spaced 15-Hz-wide bands of noise. The signal was a tone or a copy of the on-signal masker band. When the masker was composed of one or more random bands, thresholds were relatively consistent across frequency. When the masker was a set of comodulated bands, thresholds for both signal types formed a bowl, but the minimum threshold occurred at a higher signal frequency for the tonal than for the narrowband noise signal. Results for additional conditions indicate that spectral effects depend on both absolute frequency and relative frequency of the signal within the masker. Data collected with flanking maskers presented contralateral to the signal and on-signal masker indicate that peripheral effects may play a role in threshold elevation at high signal frequencies with narrowband noise signals.
A stepped-plate bi-frequency source for generating a difference frequency sound with a parametric array
Authors: Je Yub , Lee Haksue , Park Jongkyu , Moon Wonkyu
Published: June 2010

An ultrasonic radiator is developed to generate a difference frequency sound from two frequencies of ultrasound in air with a parametric array. A design method is proposed for an ultrasonic radiator capable of generating highly directive, high-amplitude ultrasonic sound beams at two different frequencies in air based on a modification of the stepped-plate ultrasonic radiator. The stepped-plate ultrasonic radiator was introduced by Gallego-Juarez et al. [Ultrasonics 16, 267–271 (1978)] in their previous study and can effectively generate highly directive, large-amplitude ultrasonic sounds in air, but only at a single frequency. Because parametric array sources must be able to generate sounds at more than one frequency, a design modification is crucial to the application of a stepped-plate ultrasonic radiator as a parametric array source in air. The aforementioned method was employed to design a parametric radiator for use in air. A prototype of this design was constructed and tested to determine whether it could successfully generate a difference frequency sound with a parametric array. The results confirmed that the proposed single small-area transducer was suitable as a parametric radiator in air.
Using cross-correlations of elastic diffuse fields for attenuation tomography of structural damage
Authors: Duroux Adelaide , Sabra Karim G. , Ayers James , Ruzzene Massimo
Published: June 2010

A scanning laser Doppler vibrometer is used to measure, at multiple grid points, the diffuse vibrations (50–150 kHz) propagating over a thin aluminum plate with complex geometry. These diffuse vibrations were generated by a few pulsed laser impacts randomly distributed outside of the measurement grid. The pairwise cross-correlations of the diffuse field recorded at all grid points provided an estimate of the first antisymmetric Lamb mode direct arrival between these grid points. Attenuation tomography imaging of a simulated structural damage is performed based on the relative amplitude variations of these direct arrivals between the damaged and undamaged conditions.
Non-uniform sound intensity distributions when measuring absorption coefficients in reverberation chambers using a phased beam tracing
Authors: Jeong Cheol-Ho
Published: June 2010

Measured absorption coefficients in reverberation chambers often differ from theoretical random incidence absorption coefficients, because ideal assumptions for the theoretical random incidence absorption coefficient are not fulfilled during measurements in actual reverberation chambers. Therefore sound intensity distributions on absorber under measurement conditions have been simulated using a phased beam tracing, and used as correction functions for reducing discrepancies between the measured and theoretical absorption coefficients. Two reverberation rooms were investigated by assuming that a test specimen was attached to a vertical surface and the floor. The frequency-dependent sound intensity distributions on absorbers were found to be affected by the reverberation chamber geometry and dimensions, the absorption capability of the specimen, and the placement of the specimen. High frequency intensity distributions above 1 kHz were similar for all studied cases, but some variations in low frequency intensity distributions were observed. If the non-uniform intensity distribution and a finite size effect are taken into account for correcting the theoretical absorption coefficients, a good agreement is found between corrected and measured statistical absorption coefficients. The non-uniform sound intensity can account for the discrepancy at high frequencies.
Low-frequency pulse echo reflection of the fundamental shear horizontal mode from part-thickness elliptical defects in plates
Authors: Ma J. , Cawley P.
Published: June 2010

Defect characterization using guided ultrasonic waves remains a challenging subject and requires a full understanding of the interaction of guided waves with a realistic representation of the defect. The characteristics of pulse echo reflection of the SH0 mode from part-thickness elliptical defects in plates is studied via finite element analysis and experimental measurements. The study shows that the reflection ratio spectrum of the SH0 mode from an elliptical defect exhibits periodic pattern due to interference between reflections from the two edges of the defect. The pattern of the reflection ratio spectrum is determined by the ratio of defect length in the incidence direction to wavelength, while the magnitude is affected by the maximum depth and the effective aspect ratio of the defect. Both the pattern and magnitude of the reflection ratio spectrum are found to be highly sensitive to the incidence angle, and the form of the variation of the reflection with angle is a strong function of the defect shape. In addition, a study of circular defects with tapered depth profiles reveals that the reflection is a function of average length of the tapered defect to wavelength ratio, and the magnitude of the reflection diminishes as the ratio increases.
Source level estimation of two blue whale subspecies in southwestern Indian Ocean
Authors: Samaran Flore , Guinet Christophe , Adam Olivier , Motsch Jean-François , Cansi Yves
Published: June 2010

Blue whales produce intense, stereotypic low frequency calls that are particularly well suited for transmission over long distances. Because these calls vary geographically, they can be used to gain insight into subspecies distribution. In the Southwestern Indian Ocean, acoustic data from a triad of calibrated hydrophones maintained by the International Monitoring System provided data on blue whale calls from two subspecies: Antarctic and pygmy blue whales. Using time difference of arrival and least-squares hyperbolic methods, the range and location of calling whales were determined. By using received level of calls and propagation modeling, call source levels of both subspecies were estimated. The average call source level was estimated to 179±5 dB re 1 μParms at 1 m over the 17–30 Hz band for Antarctic blue whale and 174±1 dB re 1 μParms at 1 m over the 17–50 Hz band for pygmy blue whale. According to previous estimates, slight variations in the source level could be due to inter-individual differences, inter-subspecies variations and the calculation method. These are the first reported source level estimations for blue whales in the Indian Ocean. Such data are critical to estimate detection ranges of calling blue whales.
Detection of damage in concrete using diffuse ultrasound
Authors: Deroo Frederik , Kim Jin-Yeon , Qu Jianmin , Sabra Karim , Jacobs Laurence J.
Published: June 2010

This letter demonstrates the potential for using diffuse ultrasound measurements to detect damage in concrete. Two different solutions to the diffusion equation, an infinite three-dimensional (3D) volume model that neglects geometric boundaries and a finite 3D cuboid model, are used for the required curve fitting procedure to determine the influence of geometric boundaries on the solution. The measurements consider two types of microcrack damage in concrete, alkali-silica reaction and thermal damage, and show that the measured diffusivity parameter is related to the amount of damage in each specimen.
Material characterization of the encapsulation of an ultrasound contrast microbubble and its subharmonic response: Strain-softening interfacial elasticity model
Authors: Paul Shirshendu , Katiyar Amit , Sarkar Kausik , Chatterjee Dhiman , Shi William T. , Forsberg Flemming
Published: June 2010

Two nonlinear interfacial elasticity models—interfacial elasticity decreasing linearly and exponentially with area fraction—are developed for the encapsulation of contrast microbubbles. The strain softening (decreasing elasticity) results from the decreasing association between the constitutive molecules of the encapsulation. The models are used to find the characteristic properties (surface tension, interfacial elasticity, interfacial viscosity and nonlinear elasticity parameters) for a commercial contrast agent. Properties are found using the ultrasound attenuation measured through a suspension of contrast agent. Dynamics of the resulting models are simulated, compared with other existing models and discussed. Imposing non-negativity on the effective surface tension (the encapsulation experiences no net compressive stress) shows “compression-only” behavior. The exponential and the quadratic (linearly varying elasticity) models result in similar behaviors. The validity of the models is investigated by comparing their predictions of the scattered nonlinear response for the contrast agent at higher excitations against experimental measurement. All models predict well the scattered fundamental response. The nonlinear strain softening included in the proposed elastic models of the encapsulation improves their ability to predict subharmonic response. They predict the threshold excitation for the initiation of subharmonic response and its subsequent saturation.
A model for three-dimensional simulation of acoustic emissions from rotating machine vibration
Authors: Magalhães R. S. , Fontes C. H. O. , Almeida L. A. L. , Embiruçu M. , Santos J. M. C.
Published: June 2010

Industrial noise can be successfully mitigated with the combined use of passive and active noise control (ANC) strategies. In a noisy area, a practical solution for noise attenuation may include both the use of baffles and ANC. When the operator is required to stay in movement in a delimited spatial area, conventional ANC is usually not able to adequately cancel the noise over the whole area. Control strategies need to be devised to achieve acceptable spatial coverage. A three-dimensional vibration-acoustic model is proposed in this paper. The signal of an accelerometer attached to the bulk of a centrifugal pump installed in an empty room was used as the input of this model. The signal of a microphone that changes its position in a spatial grid inside this room is the output. In the first stage, the ARX models are used to describe a SISO system where the input is the machine vibration and the output is the noise level measured at a certain point. In the second stage, spatial interpolation is used to estimate the model parameters. Results show good agreement between experimental data and model predictions, indicating the potential of using the model for the design of ANC.
Revised Standards for Reporting Interventions in Clinical Trials of Acupuncture (Stricta): Extending the Consort Statement
Authors: MacPherson Hugh , Altman Douglas G , Hammerschlag Richard , Li Youping , Wu Taixiang , White Adrian , Moher David
Published: June 2010

The STandards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA) were published in five journals in 2001 and 2002. These guidelines, in the form of a checklist and explanations for use by authors and journal editors, were designed to improve reporting of acupuncture trials, particularly the interventions, thereby facilitating their interpretation and replication. Subsequent reviews of the application and impact of STRICTA have highlighted the value of STRICTA as well as scope for improvements and revision.

To manage the revision process a collaboration between the STRICTA Group, the CONSORT Group and the Chinese Cochrane Centre was developed in 2008. An expert panel with 47 participants was convened that provided electronic feedback on a revised draft of the checklist. At a subsequent face-to-face meeting in Freiburg, a group of 21 participants further revised the STRICTA checklist and planned dissemination.

The new STRICTA checklist, which is an official extension of CONSORT, includes 6 items and 17 subitems. These set out reporting guidelines for the acupuncture rationale, the details of needling, the treatment regimen, other components of treatment, the practitioner background and the control or comparator interventions. In addition, and as part of this revision process, the explanations for each item have been elaborated, and examples of good reporting for each item are provided. In addition, the word ‘controlled’ in STRICTA is replaced by ‘clinical’, to indicate that STRICTA is applicable to a broad range of clinical evaluation designs, including uncontrolled outcome studies and case reports. It is intended that the revised STRICTA checklist, in conjunction with both the main CONSORT statement and extension for non-pharmacological treatment, will raise the quality of reporting of clinical trials of acupuncture.
Structural tests of diapir hypotheses in Archean crust of Ontario
Authors: Schwerdtner W. M.
Published: June 2010

Detailed structural maps of two granitoid complexes in the Wabigoon Subprovince are used to test three diapir hypotheses advanced in earlier papers. The gneiss masses of, and individual domes within, the complexes fail the test for solid-state diapirism. The gneiss domes also fail the test for tensile bending caused by hypothetical magmatic diapirs in the subsurface. An oval pluton located near the best-exposed gneiss dome proves to be a synformal sheet rather than a funnel-shaped magmatic diapir. This pluton could be a syenite–diorite phacolith emplaced into a concordant zone of dilation during the late upright folding of the gneiss mass about horizontal axes. Earlier tight folds were probably recumbent and south verging and, like the gneissosity, generated in a ductile shear regime with subhorizontal glide planes. These observations have important implications for Archean tectonics, especially the relative horizontal displacement of large greenstone masses (potentially allochthonous greenstone belts).
Structural development of angular volcanic belts in the Archean Slave Province
Authors: Fyson W. K.
Published: June 2010

Narrow belts of metavolcanics lying between metasediments and granitoid rocks in the southwestern part of the Archean Slave Province display a distinctive angular map pattern. Steep homoclinal segments, from 10 to over 50 km in length, change strike abruptly at "corners" as if defining large, open, angular folds. Structures near two corners in a belt are not, however, compatible with such folds. Examples include early-phase, layer-parallel foliations in directional sets that are interspersed with one set overprinting the other; mafic dykes of similar contrasting orientations interspersed within basal gneiss; and isoclines in metasediments that deflect rather than wrap around a corner. Additionally, late-phase foliations striking across corners indicate compression that tended to straighten rather than fold the belt.It is suggested that the angular volcanic belts and imposed structures reflect movements on long-lived, crustal-scale faults. A model of development is proposed in which synvolcanic, listric extensional faults and high-angle transfer faults were reactivated as upthrusts during regional compression. Consequent tilting of the volcanics in different directions formed the angular pattern of steep homoclines and guided the development of a succession of folds and foliations.
Deep-sea sedimentary processes off Newfoundland: an overview
Authors: Jacobs Colin L.
Published: June 2010

A combination of long-range sidescan sonar, airgun seismic reflection, and high-resolution echo-sounder data has allowed an overview of the different sedimentary processes along the southeast Canadian continental slope and rise. A large sediment drift identified along almost the entire length of the margin, mainly between the 3000 and 4000 m isobaths, testifies to the importance of geostrophic processes in this region. The presence of historic gravity-flow deposits downslope from those parts of the margin that were covered by glacial ice during the Wisconsinan, coupled with a lack of similar deposits along the probable ice-free parts of the margin, suggests an association between palaeoenvironmental conditions on the continental shelf and slope stability. Differences in canyon style along the Grand Banks slope are attributed to differences in slope angle and the speed and regularity of turbidity flow.
Petrology and isotopic composition of Quaternary basanites dredged from the Bering Sea continental margin near Navarin Basin
Authors: Davis Alicé S. , Gunn Susan H. , Gray Leda-Beth , Marlow Michael S. , Wong Florence L.
Published: June 2010

Quaternary basanites were recovered from shallow water depth from the continental margin of the Bering Sea (58°39.0′N, 177°12.9′W) near Navarin Basin. The basanites are highly vesicular flow rock and hyaloclastites similar to other alkalic volcanic rocks erupted repeatedly during the late Cenozoic on islands in the Bering Sea region and in mainland Alaska. K–Ar ages for the basanites indicate at least two episodes of volcanism at about 1.1 and 0.4 Ma. Similar alkalic volcanism occurred sporadically at geographically widely separated centers in the Bering Sea region for at least the past 6 Ma. Chemically, these alkalic lavas are intraplate basalts similar to those erupted from oceanic islands and in some continental settings. Trace-element data indicate these alkalic lavas have been generated by small, but variable, amounts of partial melting of a meta-somatized lherzolite source. The relatively primitive compositions (MgO > 9%), presence of mantle-derived xenoliths in some alkalic lavas, and presence of forsteritic olivine with low CaO and high NiO suggest that magma rose rapidly from greath depth without spending time in large, long-lived magma chambers. Although lavas from different volcanic centers in the Bering Sea region are similar with respect to major elements and many trace-element ratios, isotopic compositions indicate heterogeneities in the source. The Navarin basanites have higher 87Sr/86Sr and lower 143Nd/144Nd values than any other lavas so far reported from this region. The 207Pb/204Pb isotopic ratios indicate involvement of a crustal component, which may have resulted from metasomatism associated with subduction-related magmatic activity during the Early Eocene in this region. Although some volcanic episodes appear to have occurred roughly synchronously at geographically widely separated centers, no large-scale regional extension nor presence of large mantle plumes are indicated. Instead, alkalic volcanism apparently resulted from upwelling and decompressional melting of small isolated mantle diapirs in response to local lithospheric attenuation associated with jostling of blocks during adjustment to regional stresses.
Geothermics of the Essaouira basin in Morocco
Authors: Rimi Abdelkrim
Published: June 2010

The mean values of geothermal gradient and heat flow density have been estimated from bottom-hole temperatures taken from 75 petroleum exploration wells in the Essaouira basin in Morocco and are found to be 21.0 ± 0.3 mK/m and 68 ± 8 mW/m2, respectively. The regional thermal gradient varies with depth, from 30–35 mK/m near to the surface to about 18 mK/m between 2000 and 3000 m depth and then increasing again to over 24 mK/m at depths greater than 3000 m. The decrease at intermediate depths results from the presence of Triassic evaporites (with high thermal conductivities). Comparison of the temperature pattern and petroleum occurences indicates that the hydrocarbon matured in the deep Paleozoic formations and ascended from the source rocks by both upward migration along active faults and uplift during compressional tectonics.
Geochemical characterization of mid-Cretaceous granitoids of the Kootenay Arc in the southern Canadian Cordillera
Authors: Brandon Alan D. , Lambert Richard StJ.
Published: June 2010

Within southeast British Columbia, mid-Cretaceous granitoid batholiths are exposed in the Omineca Belt, a north–south-trending metamorphic and plutonic orogenic belt. The Bugaboo, Horsethief Creek, and Fry Creek batholiths are post-kinematic with respect to regional metamorphism that affected their host rocks, and are composed of hornblende and biotite granodiorites and granites in all three batholiths, and two-mica granites in Fry Creek. The biotite granites are weakly peraluminous, have initial εSr ranging from + 36 to + 56 and initial εNd ranging from −4.8 to −7.5, and overlap the range of Nd–Sr isotopic compositions for Precambrian basement gneisses and Proterozoic metasediments found in southeast British Columbia. The initial 206Pb/204Pb versus 208Pb/204Pb and 207Pb/204Pb for these granitoids lie in bands between model lower and upper crustal Pb isotopic compositions above the Northern Hemisphere Reference Line for oceanic basalts. These granitoids have high Nb and Rb and low Ba abundances relative to granites found in volcanic arcs. The two-mica granites are strongly peraluminous and have εSr ranging from + 170 to + 470, εNd ranging from −10 to−21, and more radiogenic initial Pb-isotope ratios than the biotite granites. The two-mica granites have trace element compositions similar to those of granites found in within-plate and collisional tectonic settings.We favor a model for crustal anatexis of Precambrian basement gneisses and Proterozoic metapelites to produce the mid-Cretaceous biotite granites and two-mica granites, respectively. Crustal anatexis was likely in response to crustal thickening that occurred during the Mesozoic in southeast British Columbia as exotic terranes collided with and were accreted to the western edge of the North American continent.
Stratigraphic significance of Upper Devonian and Lower Carboniferous miospores from the type area of the Horton Group, Nova Scotia
Authors: Martel A. Thomas , McGregor D. Colin , Utting John
Published: June 2010

Late Devonian (late Famennian) miospores have been found in the lowermost 7.3 m of the Horton Group on Harding Brook in the type area, Windsor Subbasin, Nova Scotia, below Tournaisian miospores of the Emphanisporites rotatus – Indotriradites explanatus Zone. Extending the age of the Horton Group in the type area down into the latest Devonian shows that the lowest beds of the ~ 1000 m thick group are coeval with latest Devonian rocks elsewhere in the Maritimes Basin that have been excluded from the Horton Group by some authors. Evidence presented here favours the argument that Late Devonian rocks lithologically similar to the Horton Group, deposited on the Acadian unconformity, should be included in that group. Miospore evidence indicates a minimum age of about 355 Ma for exhumation of the northeastern part of the South Mountain Batholith.
Genomic Screening with RNAi: Results and Challenges
Authors: Mohr Stephanie , Bakal Chris , Perrimon Norbert
Published: June 2010

RNA interference (RNAi) is an effective tool for genome-scale, high-throughput analysis of gene function. In the past five years, a number of genome-scale RNAi high-throughput screens (HTSs) have been done in both Drosophila and mammalian cultured cells to study diverse biological processes, including signal transduction, cancer biology, and host cell responses to infection. Results from these screens have led to the identification of new components of these processes and, importantly, have also provided insights into the complexity of biological systems, forcing new and innovative approaches to understanding functional networks in cells. Here, we review the main findings that have emerged from RNAi HTS and discuss technical issues that remain to be improved, in particular the verification of RNAi results and validation of their biological relevance. Furthermore, we discuss the importance of multiplexed and integrated experimental data analysis pipelines to RNAi HTS.
High-Throughput Metabolic Engineering: Advances in Small-Molecule Screening and Selection
Authors: Dietrich Jeffrey A. , McKee Adrienne E. , Keasling Jay D.
Published: June 2010

Metabolic engineering for the overproduction of high-value small molecules is dependent upon techniques in directed evolution to improve production titers. The majority of small molecules targeted for overproduction are inconspicuous and cannot be readily obtained by screening. We provide a review on the development of high-throughput colorimetric, fluorescent, and growth-coupled screening techniques, enabling inconspicuous small-molecule detection. We first outline constraints on throughput imposed during the standard directed evolution workflow (library construction, transformation, and screening) and establish a screening and selection ladder on the basis of small-molecule assay throughput and sensitivity. An in-depth analysis of demonstrated screening and selection approaches for small-molecule detection is provided. Particular focus is placed on in vivo biosensor-based detection methods that reduce or eliminate in vitro assay manipulations and increase throughput. We conclude by providing our prospectus for the future, focusing on transcription factor-based detection systems as a natural microbial mode of small-molecule detection.
Chemical Approaches to Glycobiology
Authors: Kiessling Laura L. , Splain Rebecca A.
Published: June 2010

Glycans are ubiquitous components of all organisms. Efforts to elucidate glycan function and to understand how they are assembled and disassembled can reap benefits in fields ranging from bioenergy to human medicine. Significant advances in our knowledge of glycan biosynthesis and function are emerging, and chemical biology approaches are accelerating the pace of discovery. Novel strategies for assembling oligosaccharides, glycoproteins, and other glycoconjugates are providing access to critical materials for interrogating glycan function. Chemoselective reactions that facilitate the synthesis of glycan-substituted imaging agents, arrays, and materials are yielding compounds to interrogate and perturb glycan function and dysfunction. To complement these advances, small molecules are being generated that inhibit key glycan-binding proteins or biosynthetic enzymes. These examples illustrate how chemical glycobiology is providing new insight into the functional roles of glycans and new opportunities to interfere with or exploit these roles.
Reversal of Histone Methylation: Biochemical and Molecular Mechanisms of Histone Demethylases
Authors: Mosammaparast Nima , Shi Yang
Published: June 2010

The importance of histone methylation in gene regulation was suggested over 40 years ago. Yet, the dynamic nature of this histone modification was recognized only recently, with the discovery of the first histone demethylase nearly five years ago. Since then, our insight into the mechanisms, structures, and macromolecular complexes of these enzymes has grown exponentially. Overall, the evidence strongly supports a key role for histone demethylases in eukaryotic transcription and other chromatin-dependent processes. Here, we examine these and related facets of histone demethylases discovered to date, focusing on their biochemistry, structure, and enzymology.
Testicular Hamartomas and Epididymal Tumor in a Cowden Disease: A Case Report
Authors: Rasalkar Darshana D. , Paunipagar Bhawan K.
Published: June 2010

Testicular hamartomas (TH) is a benign condition. An association of TH with Cowden disease (CD) is known. Ultrasound features of hamartomas are often diagnostic. We present a case of Cowden disease with TH and an epididymal tumor. Imaging features of TH and its differentials has been discussed. Although, association of Cowden disease with many malignancies have been documented, epididymal tumor has not been described. To our knowledge, this paper is the first to describe epididymal tumor in association with Cowden disease.
Laser Ablated Silver Nanoparticles with Nearly the Same Size in Different Carrier Media
Authors: Brito-Silva Antonio M. , Gómez Luiz A. , de Araújo Cid B. , Galembeck André
Published: June 2010

Poly(vinyl‐pyrrolidone) (PVP) stabilized silver nanoparticles with an average particle size ranging from 4.3 to 4.9 nm were synthesized by laser ablation in preformed colloids in methanol, acetone, ethylene glycol, and glycerin. Aqueous colloids obtained using PVP, poly(vinyl‐alcohol) (PVA), and sodium citrate as stabilizing agents also lead to a good control over particle size distribution. Silver ions were reduced with sodium borohydride. The smaller average particle size and narrower dispersivity in comparison to previously reported data were ascribed to the relatively small size of the particles formed in the chemical reduction step, laser fluence, and the use of PVP, which was not previously used as the stabilizing agent in “top‐down” routes. The surface plasmon resonance band maximum wavelength shifted from 398 nm in methanol to 425 nm in glycerin. This shift must be due to solvent effects since all other variables were the same.
On the Error Rate Analysis of Dual‐Hop Amplify‐and‐Forward Relaying in Generalized‐K Fading Channels
Authors: Efthymoglou George P. , Bissias Nikolaos , Aalo Valentine A.
Published: June 2010

We present novel and easy‐to‐evaluate expressions for the error rate performance of cooperative dual‐hop relaying with maximal ratio combining operating over independent generalized‐K fading channels. For this system, it is hard to obtain a closed‐form expression for the moment generating function (MGF) of the end‐to‐end signal‐to‐noise ratio (SNR) at the destination, even for the case of a single dual‐hop relay link. Therefore, we employ two different upper bound approximations for the output SNR, of which one is based on the minimum SNR of the two hops for each dual‐hop relay link and the other is based on the geometric mean of the SNRs of the two hops. Lower bounds for the symbol and bit error rates for a variety of digital modulations can then be evaluated using the MGF‐based approach. The final expressions are useful in the performance evaluation of amplify‐and‐forward relaying in a generalized composite radio environment.
Oral Health Status of Children Living in Gorom-Gorom, Oudalan District, Burkina Faso
Authors: Mazza Clelia , Strohmenger Laura , Campus Guglielmo , Cagetti Maria Grazia , Caruso Filippo , Petersen Poul Erik
Published: June 2010

Aim. In order to set up the needs for intervention and to plan oral health prevention and care programmes, this paper aims to describe the oral health status and behaviour in children living in the municipality of Gorom-Gorom, Burkina Faso.Design. The sample size was 692 children, 334 females (48.3%) and 358 males (51.7%). Clinical and oral health related behaviours were collected.Results. 83.4% of the children were caries-free. Fluorosis was recorded in 41.3% of the sample, while only 37.9% of children showed healthy gingival condition. Toothbrushing was reported by 35.7% of children. A statistically significant association was found between caries experience and cleanliness of hands. Community Periodontal Index was statistically associated to toothbrushing and chewingstick use.Conclusion. As suggested by WHO's global strategies, integrated primary oral health care and services meeting the dental needs of the local population are necessary for children living in this area of Africa.
An Intercomparison of GPS RO Retrievals with Colocated Analysis and In Situ Observations within Tropical Cyclones
Authors: Winterbottom Henry R. , Xiao Qingnong
Published: June 2010

Observations from four Global Position System (GPS) Radio Occultation (RO) missions: Global Positioning System/Meteorology, CHAallenging Minisatellite Payload, Satellite de Aplicaciones Cientificas‐C, and Constellation Observing System for Meteorology, Ionosphere and Climate and Taiwan′s FORMOsa SATellite Mission #3 (COSMIC/FORMOSAT‐3) are collected within a 600 km radius and ±180 minute temporal window of all observed tropical cyclones (TCs) from 1995 to 2006 that were recorded in the global hurricane best‐track reanalysis data set (Jarvinen et al. (1984); Davis et al. (1984)). A composite analysis of tropical cyclone radial mean temperature and water vapor profiles is carried out using the GPS RO retrievals which are colocated with global analysis profiles and available in situ radiosonde observations. The differences between the respective observations and analysis profiles are quantified and the preliminary results show that the observations collected within TCs correspond favorably with both the analysis and radiosonde profiles which are colocated. It is concluded that GPS RO observations will contribute significantly to the understanding and modeling of TC structures, especially those related to vertical variability of the atmospheric state within TCs.
Phylogenetic Relationships of Tetraploid AB-Genome Avena Species Evaluated by Means of Cytogenetic (C-Banding and FISH) and RAPD Analyses
Authors: Badaeva E. D. , Shelukhina O. Yu. , Goryunova S. V. , Loskutov I. G. , Pukhalskiy V. A.
Published: June 2010

Tetraploid oat species Avena abyssinica, A. vaviloviana, A. barbata, and A. agadiriana were studied using C-banding technique, in situ hybridization with the 45S and 5S rDNA probes, and RAPD analysis in comparison with the diploid species carrying different types of the A-genome (A. wiestii, As; A. longiglumis, Al; A. canariensis, Ac; A. damascena, Ad, A. prostrata, Ap). The investigation confirmed that all four tetraploids belong to the same AB-genome group; however A. agadiriana occupies distinct position among others. The C-banding, FISH, and RAPD analyses showed that Avena abyssinica, A. vaviloviana, and A. barbata are very similar; most probably they originated from a common tetraploid ancestor as a result of minor translocations and alterations of C-banding polymorphism system. AB-genome species are closely related with the A-genome diploids, and an As-genome species may be regarded as the most probable donor of their A-genome. Although their second diploid progenitor has not been identified, it seems unlikely that it belongs to the As-genome group. The exact diploid progenitors of A. agadiriana have not been determined; however our results suggest that at least one of them could be related to A. damascena.
Synthetic Peptides as Structural Maquettes of Angiotensin‐I Converting Enzyme Catalytic Sites
Authors: Spyranti Zinovia , Galanis Athanassios S. , Pairas George , Spyroulias Georgios A. , Manessi-Zoupa Evy , Cordopatis Paul
Published: June 2010

The rational design of synthetic peptides is proposed as an efficient strategy for the structural investigation of crucial protein domains difficult to be produced. Only after half a century since the function of ACE was first reported, was its crystal structure solved. The main obstacle to be overcome for the determination of the high resolution structure was the crystallization of the highly hydrophobic transmembrane domain. Following our previous work, synthetic peptides and Zinc(II) metal ions are used to build structural maquettes of the two Zn‐catalytic active sites of the ACE somatic isoform. Structural investigations of the synthetic peptides, representing the two different somatic isoform active sites, through circular dichroism and NMR experiments are reported.
Using Video Self-Modelled Social Stories to Teach Social Skills to a Young Child with Autism
Authors: Litras Stacey , Moore Dennis W. , Anderson Angelika
Published: June 2010

The present study investigated the effectiveness of combining Social Stories and Video Self-Modelling (VSM) to teach social skills to a three-year-old child with autism. A multiple-baseline across behaviors design revealed that video self-modelled Social Stories were effective at improving all three target behaviors: greeting, inviting to play, and contingent responding. In addition, these behaviors successfully generalized across settings, toys, and communication partners. Concomitant behavior changes, namely, increased levels of communicative behavior and levels of social engagement were also observed. These results support the effectiveness of video self-modelled Social Stories and illustrate the potential of combined intervention techniques for remedying the social deficits faced by this population.
The Phosphoinositide 3-Kinase Regulatory Subunit p85α Can Exert Tumor Suppressor Properties through Negative Regulation of Growth Factor Signaling
Authors: Taniguchi Cullen M. , Winnay Jonathon , Kondo Tatsuya , Bronson Roderick T. , Guimaraes Alexander R. , Alemán José O. , Luo Ji , Stephanopoulos Gregory , Weissleder Ralph , Cantley Lewis C. , Kahn C. Ronald
Published: June 2010

Phosphoinositide 3-kinase (PI3K) plays a critical role in tumorigenesis, and the PI3K p85 regulatory subunit exerts both positive and negative effects on signaling. Expression of Pik3r1, the gene encoding p85, is decreased in human prostate, lung, ovarian, bladder, and liver cancers, consistent with the possibility that p85 has tumor suppressor properties. We tested this hypothesis by studying mice with a liver-specific deletion of the Pik3r1 gene. These mice exhibited enhanced insulin and growth factor signaling and progressive changes in hepatic pathology, leading to the development of aggressive hepatocellular carcinomas with pulmonary metastases. Liver tumors that arose exhibited markedly elevated levels of phosphatidylinositol (3,4,5)-trisphosphate, along with Akt activation and decreased PTEN expression, at both the mRNA and protein levels. Together, these results substantiate the concept that the p85 subunit of PI3K has a tumor-suppressive role in the liver and possibly other tissues. Cancer Res; 70(13); 5305–15. ©2010 AACR.
Halogenated Benzimidazole Carboxamides Target Integrin α4β1 on T-Cell and B-Cell Lymphomas
Authors: Carpenter Richard D. , Natarajan Arutselvan , Lau Edmond Y. , Andrei Mirela , Solano Danielle M. , Lightstone Felice C. , DeNardo Sally J. , Lam Kit S. , Kurth Mark J.
Published: June 2010

Integrin α4β1 is an attractive but poorly understood target for selective diagnosis and treatment of T-cell and B-cell lymphomas. This report focuses on the rapid microwave preparation, structure-activity relationships, and biological evaluation of medicinally pertinent benzimidazole heterocycles as integrin α4β1 antagonists. We documented tumor uptake of derivatives labeled with 125I in xenograft murine models of B-cell lymphoma. Molecular homology models of integrin α4β1 predicted that docked halobenzimidazole carboxamides have the halogen atom in a suitable orientation for halogen-hydrogen bonding. The high-affinity halogenated ligands identified offer attractive tools for medicinal and biological use, including fluoro and iodo derivatives with potential radiodiagnostic (18F) or radiotherapeutic (131I) applications, or chloro and bromo analogues that could provide structural insights into integrin-ligand interactions through photoaffinity, cross-linking/mass spectroscopy, and X-ray crystallographic studies. Cancer Res; 70(13); 5448–56. ©2010 AACR.
PTEN Loss Compromises Homologous Recombination Repair in Astrocytes: Implications for Glioblastoma Therapy with Temozolomide or Poly(ADP-Ribose) Polymerase Inhibitors
Authors: McEllin Brian , Camacho Cristel V. , Mukherjee Bipasha , Hahm Brandon , Tomimatsu Nozomi , Bachoo Robert M. , Burma Sandeep
Published: June 2010

Glioblastomas (GBM) are lethal brain tumors that are highly resistant to therapy. The only meaningful improvement in therapeutic response came from use of the SN1-type alkylating agent temozolomide in combination with ionizing radiation. However, no genetic markers that might predict a better response to DNA alkylating agents have been identified in GBMs, except for loss of O6-methylguanine-DNA methyltransferase via promoter methylation. In this study, using genetically defined primary murine astrocytes as well as human glioma lines, we show that loss of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) confers sensitivity to N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), a functional analogue of temozolomide. We find that MNNG induces replication-associated DNA double-strand breaks (DSB), which are inefficiently repaired in PTEN-deficient astrocytes and trigger apoptosis. Mechanistically, this is because PTEN-null astrocytes are compromised in homologous recombination (HR), which is important for the repair of replication-associated DSBs. Our results suggest that reduced levels of Rad51 paralogs in PTEN-null astrocytes might underlie the HR deficiency of these cells. Importantly, the HR deficiency of PTEN-null cells renders them sensitive to the poly(ADP-ribose) polymerase (PARP) inhibitor ABT-888 due to synthetic lethality. In sum, our results tentatively suggest that patients with PTEN-null GBMs (about 36%) may especially benefit from treatment with DNA alkylating agents such as temozolomide. Significantly, our results also provide a rational basis for treating the subgroup of patients who are PTEN deficient with PARP inhibitors in addition to the current treatment regimen of radiation and temozolomide. Cancer Res; 70(13); 5457–64. ©2010 AACR.
Colorectal Cancer Incidence Trends in the United States and United Kingdom: Evidence of Right- to Left-Sided Biological Gradients with Implications for Screening
Authors: Meza Rafael , Jeon Jihyoun , Renehan Andrew G. , Luebeck E. Georg
Published: June 2010

Several lines of evidence support the premise that screening colonoscopy reduces colorectal cancer (CRC) incidence, but there may be differential benefits for right- and left-sided tumors. To better understand the biological basis of this differential effect, we derived biomathematical models of CRC incidence trends in U.S. and U.K. populations, representing relatively high- and low-prevalence screening, respectively. Using the Surveillance Epidemiology and End Results (SEER) and the Office for National Statistics (ONS) registries (both 1973–2006), we derived stochastic multistage clonal expansion (MSCE) models for right-sided (proximal colon) and left-sided (distal colon and rectal) tumors. The MSCE concept is based on the initiation-promotion-progression paradigm of carcinogenesis and provides a quantitative description of natural tumor development from the initiation of an adenoma (via biallelic tumor suppressor gene inactivation) to the clinical detection of CRC. From 1,228,036 (SEER: 340,582; ONS: 887,454) cases, parameter estimates for models adjusted for calendar-year and birth-cohort effects showed that adenoma initiation rates were higher for right-sided tumors, whereas, paradoxically, adenoma growth rates were higher for left-sided tumors. The net effect was a higher cancer risk in the right colon only after age 70 years. Consistent with this finding, simulations of adenoma development predicted that the relative prevalence for right- versus left-sided tumors increases with increasing age, a differential effect most striking in women. Using a realistic biomathematical description of CRC development for two nationally representative registries, we show age- and sex-dependent biological gradients for right- and left-sided colorectal tumors. These findings argue for an age-, sex-, and site-directed approach to CRC screening. Cancer Res; 70(13); 5419–29. ©2010 AACR.