bluuebunny/crossref_metadata_2025_split huggingface dataset:
Li‐, Sb‐ and Ta‐modified (K, Na)NbO3 nanopowder prepared via a water‐based sol–gel method
Authors: Fang Jian , Wang Xiaohui , Li Longtu 
Published: January 2012

AbstractStable Li‐, Sb‐ and Ta‐modified (K, Na)NbO3 (LTS‐KNN) sol and gel were successfully prepared via an economical water‐based sol–gel method. Simultaneous thermogravimetry and differential scanning calorimetry (TG‐DSC) and X‐ray diffraction showed that organic compounds were eliminated and a pure perovskite phase formed around 600 °C. Transmission electron microscopy showed that the LTS‐KNN particle size was in the range of 11–34 nm after decomposition at 600 °C. Moreover, high performance LTS‐KNN ceramic was successfully prepared at a low sintering temperature of 1000 °C by use of the nanopowder, and its room‐temperature d33, Kp, K and loss are 311 pC/N, 46.8%, 1545 and 0.024, respectively. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐temperature photoluminescence of oxide‐covered single‐layer MoS2
Authors: Plechinger G. , Schrettenbrunner F.‐X. , Eroms J. , Weiss D. , Schüller C. , Korn T. 
Published: January 2012

AbstractWe present a photoluminescence study of single‐layer MoS2 flakes on SiO2 surfaces. We demonstrate that the luminescence peak position of flakes prepared from natural MoS2, which varies by up to 25 meV between individual flakes, can be homogenized by annealing in vacuum. We use HfO2 and Al2O3 layers prepared by atomic layer deposition to cover some of our flakes. In these flakes, we observe a suppression of the low‐energy luminescence peak which appears in asprepared flakes at low temperatures. We infer that this peak originates from excitons bound to surface adsorbates. We also observe different temperature‐induced shifts of the luminescence peaks for the oxide‐covered flakes. This effect stems from the different thermal expansion coefficients of the oxide layers and the MoS2 flakes. It indicates that the single‐layer MoS2 flakes strongly adhere to the oxide layers and are therefore strained. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New Zealand green-lipped mussels (Perna canaliculus) enhance non-haem iron absorptionin vitro
Authors: Stewart Robin J. C. , Coad Jane , Reynolds Gordon W. , Pedley Kevin C. 
Published: January 2012

Fe bioavailability can be manipulated by the nutritional composition of a meal. Ascorbic acid and unidentified components of meat, fish and poultry, but particularly beef, all appear to enhance the absorption of non-haem Fe. The aim of the present study is to identify whether extracts of green-lipped mussels (GLM;Perna canaliculus) enhance non-haem Fe absorption in Caco-2 cells and to compare the effect with that of beef. Raw GLM and raw beef homogenates were digestedin vitrowith pepsin at pH 2, and pancreatin and bile salts at pH 7. Tracer55Fe was used to measure cellular Fe uptake. Ascorbic acid was used as a positive control and egg albumin, exposed to the samein vitrodigestion process, was used as a negative control. Caco-2 cell monolayers were incubated with treatments for 60 min. All values were standardised per μg of GLM, egg albumin, beef or ascorbic acid. The results showed that ascorbic acid enhanced non-haem Fe absorption to the highest degree. Beef and GLM digestates both significantly enhanced Fe absorption compared with egg albumin. In conclusion, GLM digestate significantly enhances non-haem Fe uptake in Caco-2 cells with a similar magnitude to that of beef.
Multiplicity of solutions to the weighted critical quasilinear problems
Authors: Liang Sihua , Zhang Jihui 
Published: January 2012

AbstractWe consider a class of critical quasilinear problemswhere 0 ∈ Ω ⊂ ℝN, N ≥ 3, is a bounded domain and 1 < p < N, a < N/p, a ≤ b < a + 1, λ is a positive parameter, 0 ≤ μ < $\bar{\mu}$ ≡ ((N − p)/p − a)p, q = q*(a, b) ≡ Np/[N − pd] and d ≡ a+1 − b. Infinitely many small solutions are obtained by using a version of the symmetric Mountain Pass Theorem and a variant of the concentration-compactness principle. We deal with a problem that extends some results involving singularities not only in the nonlinearities but also in the operator.
Foraging behaviour and diet selection of free-ranging sheep and goats in the Negev Desert, Israel
Authors: KAM M. , EL-MECCAWI S. , DEGEN A. A. 
Published: January 2012

SUMMARYThe foraging behaviour and dietary selection of free-ranging Awassi sheep and Negev goats when shepherded in the Negev Desert was determined. Measurements were made for 9 weeks (W1–W9) from the beginning of February, following winter rains and emergence of annual plants, to the end of March, after the herbaceous vegetation dried up. Since sheep are grazers and goats are intermediate feeders, it was predicted that goats would browse more and consume proportionately more browse than sheep. These predictions were only partially supported. In fact, the foraging pattern was similar between sheep and goats (Mantel test, P<0·05) until W8 and only towards the end, at W9, did patterns differ significantly (Mantel test, P=0·214) between these two ruminants. There was no difference (P=0·575) between sheep and goats in foraging; however, a period effect was found (P<0·001). In February (W2), sheep and goats grazed 0·69 and 0·71 of the time allotted for foraging and neither species browsed. Browsing commenced only at the beginning of March (W4), when goats browsed 0·08 of the time and sheep 0·07 of the allotted time for foraging. The proportion of time spent browsing increased at the end of March (W9) when annuals disappeared, but the total time spent foraging decreased: goats browsed 0·29 and grazed 0·25, while sheep browsed 0·19 and grazed 0·26 of the time allotted for foraging. Goats increased the proportion of browse consumed gradually throughout the season, whereas sheep maintained a relatively higher proportion of herbaceous plants and only in late March (W8), at which time very little herbaceous plants were available, shifted abruptly to consume mainly browse. In W8, browse composed 0·85 of the dry matter (DM) intake in goats and 0·62 of the DM intake in sheep. A simultaneous analysis of foraging time allocation and relative diet composition revealed that both small ruminants were more efficient in consuming browse than herbaceous plants, more so in goats than sheep. It was concluded that vegetation availability and foraging habits affected dietary selection. Both sheep and goats only grazed when herbaceous plants were abundantly available; differences between ruminant species were apparent when herbaceous plants became scarcer, at which time goats browsed more and consumed proportionately more browse than sheep. The results contribute to better understanding of feeding behaviour and dietary selection of sheep and goats under natural desert pastures and could be useful in the management of mixed flocks.
The absent piece of skin: Gendered, racialized and territorial inscriptions of sexual violence during the Bangladesh war
Authors: MOOKHERJEE NAYANIKA 
Published: January 2012

AbstractThis paper addresses how the wombs of women and the absent skin on the circumcised penises of men become the predominant sites on which racialized and gendered discourses operating during the Bangladesh War are inscribed. This is explored by examining instances of sexual violence by Pakistani soldiers and their local Bengali collaborators. The prevalence of these discourses in colonial documents about the Bengali Muslims underscores the role of history, the politics of identity and in the process, establishes its link with the rapes of Bangladeshi women and men. Through this, the relationship between sexual violence and historical contexts is highlighted. I locate the accounts of male violations by the West Pakistani army within the historical and colonial discourses relating to the construction of the Bengali Muslim and its intertextual, contemporary citational references in photographs and interviews.I draw on Judith Butler's and Marilyn Strathern's work on gendering and performativity to address the citational role of various practices of discourses of gender and race within colonial documents and its application in a newer context of colonization and sexual violence of women and men during wars. The role of photographs and image-making is intrinsic to these practices. The open semiotic of the photographs allows an exploration of the territorial identities within these images and leads to traces of the silence relating to male violations. Through an examination of the silence surrounding male sexual violencevis-à-visthe emphasis on the rape of women in independent Bangladesh, it is argued that these racialized and gendered discourses are intricately associated to the link between sexuality and the state in relation to masculinity.
Morphological, biological and molecular characterization of three strains ofTrypanosoma cruziChagas, 1909 (Kinetoplastida, Trypanosomatidae) isolated fromTriatoma sordida(Stal) 1859 (Hemiptera, Reduviidae) and a domestic cat
Authors: RIMOLDI ALINE , TOMÉ ALVES RENATA , AMBRÓSIO DANIELA LUZ , FERNANDES MARIA ZENAIDE TITA , MARTINEZ ISABEL , DE ARAÚJO RENATO FREITAS , CICARELLI REGINA MARIA BARRETO , DA ROSA JOÃO ARISTEU 
Published: January 2012

SUMMARYA study was conducted of the biological, morphological and molecular characters of 3 strains ofTrypanosoma cruzi(SI5, SI8and SIGR3) isolated from specimens ofTriatoma sordidacollected in Santo Inácio and a domestic cat. In order to carry out the study, the following parameters were evaluated: pre-patent period, parasitaemia curves, morphology of the parasites, mortality rates, histopathological lesions and molecular typing. The strains presented variable pre-patent periods, low parasitaemia and no animal mortality. The morphological study of trypomastigotes showed a predominance of intermediate-width and short-length forms, as well as low nuclear index. Epimastigotes presented a low nuclear index, intermediate-width forms in strains SI5and SI8, and large-width forms in SIGR3. A shorter length could be noted in strains SI8and SIGR3, whereas SI5displayed an intermediate length. The histopathological study did not detect amastigote nests in tissues. The amplification of the divergent domain of 24SαrRNA, HSP60 and GPI genes of strains SI5, SI8and SIGR3classified the 3 strains into Group II. Biological parameters made it possible to classify the strains isolated in Santo Inácio (BA) into Biodeme III, Zymodeme 1 and Group II ofT. cruzi.
Effectiveness of water treatment for the removal ofCryptosporidiumandGiardiaspp.
Authors: BAJER A. , TOCZYLOWSKA B. , BEDNARSKA M. , SINSKI E. 
Published: January 2012

SUMMARYCryptosporidiumandGiardiaare intestinal parasites of humans and of many other species of animals. Water constitutes an important route of transmission for human infections in both developed and developing countries. In Poland, contamination of water sources with oocysts/cysts is not routinely monitored and scientific research in this field is scarce. Our aim was to compare the contamination of surface and treated water and thus the success of water treatment processes. Water samples (n=94) of between 30 l (surface water) to over 1000 l for tap water, were taken in the period of 2008–2009 using specially constructed equipment with cartridge filtration (Filta-Max; IDEXX, USA). Immunofluorescent assay, and nested polymerase chain reaction were used for the detection of parasites.Cryptosporidiumoocysts were found in 85% of surface water and in 59% of raw (intake) water samples. Oocysts were also detected in treated water (16%) but were absent in samples of swimming pool water. The highest mean number ofCryptosporidiumoocysts [geometric mean (GM)=61/10 l] was found in samples of rinsing water.Giardiacysts were observed in 61% of surface water samples, in 6% of raw water and in 19% of treated water, with the highest number of cysts noted in rinsing water samples (GM=70 cysts/10 l). Our study highlights the frequent occurrence of parasites in surface waters in Poland and the effectiveness of water treatment for the removal of parasites from drinking water.
Raman analysis of blue ice tephra: an approach to tephrachronological dating of ice cores
Authors: Barletta Robert E. 
Published: January 2012

AbstractTephra in glacial ice provide a method to obtain a depth vs chronology correlation within an ice core. Currently, core sections containing particulate must be sacrificially analysed to determine the nature of the particulate (e.g. aerosol, micrometeor, volcanic ash), and, in the case of volcanic ash, the event tied to the particle. Characterization through melting and chemical analysis precludes, de facto, its use for other purposes. A non-destructive technique to characterize particulates in ice cores prior to sectioning the samples, e.g. optical interrogation, would be useful, especially if chemical information specific to particular volcanic eruptions could be gleaned from such an analysis. We investigated the use of micro-Raman spectroscopy for this purpose. Spectra were obtained on samples of Antarctic blue ice tephra from different sources along with a reference ash sample of New Mexico Bandelier Tuff. Vitreous and crystalline particles in the samples were characterized. For vitreous material, a detailed analysis of the Raman-active vibrational bands of the glass structure was found to have the potential of being a unique identifier of the source of the glass, however, additional library development is needed for implementation.
Developing a visual temporal modeller: applying an extensible nlp system to support learners’ understanding of tense and aspect in English
Authors: Kerins John , Ramsay Allan 
Published: January 2012

AbstractThis paper reports on the development of a prototype tool which shows how learners can be helped to reflect upon the accuracy of their writing. Analysis of samples of freely written texts by intermediate and advanced learners of English as a foreign language (EFL) showed evidence of weakness in the use of tense and aspect. Computational discourse modelling techniques were applied to the data to generate semantic models of fragments of the narratives with particular focus on their temporal structure. These models have been converted into dynamic graphical representations of the temporal relationships between discourse events as the narratives are written. The system also provides access to the ontology devised to model individual events and this offers learners insights into the events’ semantic properties. These techniques provide the basis for a stimulating learning tool capable of capturing key elements of written narratives, and prompting learners’ awareness of language use, particularly tense and aspect.
Dye Surface Coating Enables Visible Light Activation of TiO2 Nanoparticles Leading to Degradation of Neighboring Biological Structures
Authors: Blatnik Jay , Luebke Lanette , Simonet Stephanie , Nelson Megan , Price Race , Leek Rachael , Zeng Leyong , Wu Aiguo , Brown Eric 
Published: January 2012

AbstractBiologically and chemically modified nanoparticles are gaining much attention as a new tool in cancer detection and treatment. Herein, we demonstrate that an alizarin red S (ARS) dye coating on TiO2 nanoparticles enables visible light activation of the nanoparticles leading to degradation of neighboring biological structures through localized production of reactive oxygen species. Successful coating of nanoparticles with dye is demonstrated through sedimentation, spectrophotometry, and gel electrophoresis techniques. Using gel electrophoresis, we demonstrate that visible light activation of dye-TiO2 nanoparticles leads to degradation of plasmid DNA in vitro. Alterations in integrity and distribution of nuclear membrane associated proteins were detected via fluorescence confocal microscopy in HeLa cells exposed to perinuclear localized ARS-TiO2 nanoparticles that were photoactivated with visible light. This study expands upon previous studies that indicated dye coatings on TiO2 nanoparticles can serve to enhance imaging, by clearly showing that dye coatings on TiO2 nanoparticles can also enhance the photoreactivity of TiO2 nanoparticles by allowing visible light activation. The findings of our study suggest a therapeutic application of dye-coated TiO2 nanoparticles in cancer research; however, at the same time they may reveal limitations on the use of dye assisted visualization of TiO2 nanoparticles in live-cell imaging.
Characterization of Nanometer-Scale Porosity in Reservoir Carbonate Rock by Focused Ion Beam–Scanning Electron Microscopy
Authors: Bera Bijoyendra , Gunda Naga Siva Kumar , Mitra Sushanta K. , Vick Douglas 
Published: January 2012

AbstractSedimentary carbonate rocks are one of the principal porous structures in natural reservoirs of hydrocarbons such as crude oil and natural gas. Efficient hydrocarbon recovery requires an understanding of the carbonate pore structure, but the nature of sedimentary carbonate rock formation and the toughness of the material make proper analysis difficult. In this study, a novel preparation method was used on a dolomitic carbonate sample, and selected regions were then serially sectioned and imaged by focused ion beam–scanning electron microscopy. The resulting series of images were used to construct detailed three-dimensional representations of the microscopic pore spaces and analyze them quantitatively. We show for the first time the presence of nanometer-scale pores (50–300 nm) inside the solid dolomite matrix. We also show the degree of connectivity of these pores with micron-scale pores (2–5 μm) that were observed to further link with bulk pores outside the matrix.
Shear wave reflectivity imaging of the Nazca‐South America subduction zone: Stagnant slab in the mantle transition zone?
Authors: Contenti Sean , Gu Yu Jeffrey , Ökeler Ahmet , Sacchi Mauricio D. 
Published: January 2012

In this study we utilize over 5000 SS waveforms to investigate the high‐resolution mantle reflectivity structure down to 1200 km beneath the South American convergent margin. Our results indicate that the dynamics of the Nazca subduction are more complex than previously suggested. The 410‐ and 660‐km seismic discontinuities beneath the Pacific Ocean and Amazonian Shield exhibit limited lateral depth variations, but their depths vary substantially in the vicinity of the subducting Nazca plate. The reflection amplitude of the 410‐km discontinuity is greatly diminished in a ∼1300‐km wide region in the back‐arc of the subducting plate, which is likely associated with a compositional heterogeneity on top of the upper mantle transition zone. The underlying 660‐km discontinuity is strongly depressed, showing localized depth and amplitude variations both within and to the east of the Wadati‐Benioff zone. The width of this anomalous zone (∼1000 km) far exceeds that of the high‐velocity slab structure and suggesting significant slab deformation within the transition zone. The shape of the 660‐km discontinuity and the presence of lower mantle reflectivity imply both stagnation and penetration are possible as the descending Nazca slab impinges upon the base of the upper mantle.
Structure–function studies of a plant tyrosyl-DNA phosphodiesterase provide novel insights into DNA repair mechanisms of Arabidopsis thaliana
Authors: Kim Hoyeun , Na Sang Hyeon , Lee So-Young , Jeong Young-Min , Hwang Hyun-Ju , Hur Jae Young , Park Sang-Hyun , Woo Je-Chang , Kim Sang-Gu 
Published: January 2012

TDP1 (tyrosyl-DNA phosphodiesterase 1), a member of the PLD (phospholipase D) superfamily, catalyses the hydrolysis of a phosphodiester bond between a tyrosine residue and the 3′-phosphate of DNA. We have previously identified and characterized the AtTDP gene in Arabidopsis thaliana, an orthologue of yeast and human TDP1 genes. Sequence alignment of TDP1 orthologues revealed that AtTDP has both a conserved C-terminal TDP domain and, uniquely, an N-terminal SMAD/FHA (forkhead-associated) domain. To help understand the function of this novel enzyme, we analysed the substrate saturation kinetics of full-length AtTDP compared with a truncated AtTDP mutant lacking the N-terminal FHA domain. The recombinant AtTDP protein hydrolysed a single-stranded DNA substrate with Km and kcat/Km values of 703±137 nM and (1.5±0.04)×109M−1·min−1 respectively. The AtTDP-(Δ1–122) protein (TDP domain) showed kinetic parameters that were equivalent to those of the full-length AtTDP protein. A basic amino acid sequence (RKKVKP) within the AtTDP-(Δ123–605) protein (FHA domain) was necessary for nuclear localization of AtTDP. Analysis of active-site mutations showed that a histidine and a lysine residue in each of the HKD motifs were critical for enzyme activity. Vanadates, inhibitors of phosphoryl transfer reactions, inhibited AtTDP enzymatic activity and retarded the growth of an Arabidopsis tdp mutant. Finally, we showed that expression of the AtTDP gene could complement a yeast tdp1Δrad1Δ mutant, rescuing the growth inhibitory effects of vanadate analogues and CPT (camptothecin). Taken together, the results of the present study demonstrate the structure-based function of AtTDP through which AtTDP can repair DNA strand breaks in plants.
Hydrogen bonds in the nucleobase-gold complexes: Photoelectron spectroscopy and density functional calculations
Authors: Cao Guo-Jin , Xu Hong-Guang , Li Ren-Zhong , Zheng Weijun 
Published: January 2012

The nucleobase-gold complexes were studied with anion photoelectron spectroscopy and density functional calculations. The vertical detachment energies of uracil-Au−, thymine-Au−, cytosine-Au−, adenine-Au−, and guanine-Au− were estimated to be 3.37 ± 0.08 eV, 3.40 ± 0.08 eV, 3.23 ± 0.08 eV, 3.28 ± 0.08 eV, and 3.43 ± 0.08 eV, respectively, based on their photoelectron spectra. The combination of photoelectron spectroscopy experiments and density functional calculations reveals the presence of two or more isomers for these nucleobase-gold complexes. The major isomers detected in the experiments probably are formed by Au anion with the canonical tautomers of the nucleobases. The gold anion essentially interacts with the nucleobases through N-H···Au hydrogen bonds.
Exploring Strategies for Gizzard Shad Removal That Account for Compensatory Density Dependence and Uncertainty
Authors: Catalano Matthew J. , Allen Micheal S. 
Published: January 2012

Abstract
Gizzard shad Dorosoma cepedianum have been the target of removal efforts in eastern North American lakes due to their omnivorous feeding, which may increase nutrient cycling and contribute to high phytoplankton abundance. We used a simulation model to evaluate the efficacy of a gizzard shad removal program at the Harris Chain of Lakes (HCL), Florida, by testing the effects of the exploitation rate, gill-net mesh size, and harvest interval on the total population biomass and spawning potential ratio (SPR). The analysis accounted for compensatory density dependence of the gizzard shad population and uncertainty in life history parameters. The reductions in gizzard shad biomass and SPR were less than 50% for the two largest mesh sizes (89 and 102 mm) at realistic annual exploitation rates of 0.6–0.8. However, the use of smaller mesh sizes (51 and 64 mm) produced biomass and SPR reductions that exceeded 75% at comparable harvest rates. Current removal efforts at the HCL, which employ a minimum gill-net mesh size of 102 mm, are unlikely to reduce gizzard shad biomass substantially. However, smaller mesh sizes could result in increased bycatch of economically important black crappies Pomoxis nigromaculatus. Our study sheds light on the importance of using simulation models to forecast the effects of removal efforts on target fish species. The results of such models can be used to inform harvest practices to achieve desired outcomes.
Received May 12, 2011; accepted September 12, 2011