bluuebunny/crossref_metadata_2025_split huggingface dataset:
Well‐orientated cubic boron nitride nanocrystals as studied by high‐resolution transmission electron microscopy
Authors: TSIAOUSSIS I. , FRANGIS N. 
Published: October 2006

SummaryIn a boron nitride thin film, grown on a Si (100) substrate by radio frequency magnetron sputtering, a striking nanostructure is observed by high‐resolution transmission electron microscopy. It consists of cubic boron nitride nanocrystals with a rather good triangular shape, pointing always to the substrate. The nanocrystals are usually highly defected and present their own interesting internal structure. Texture formation is observed within a nanocrystal, with all the subgrains observed to have a common <011> axis, which is also approximately parallel to a <011> axis of the Si substrate, i.e. the nanocrystals are very well structurally orientated in relation to the Si substrate (self‐organized). Dislocations and stacking faults are also found in the nanocrystals.
New developments in the characterization of dislocation loops from LACBED patterns
Authors: MORNIROLI J. P. , MARCEAU R. K. W. , RINGER S. P. 
Published: October 2006

SummaryThe characterization of the Burgers vector of dislocations from large‐angle convergent‐beam electron diffraction (LACBED) patterns is now a well‐established method. The method has already been applied to relatively large and isolated dislocation loops in semiconductors. Nevertheless, some severe experimental difficulties are encountered with small dislocation loops. By using a 2 µm selected‐area aperture and a carbon contamination point to mark the loop of interest, we were able to characterize both the plane and the Burgers vector of dislocation loops of a few tens of nanometres in size present in Al‐Cu‐Mg alloys.
Effects of surface relaxation on convergent‐beam electron diffraction analysis of stress in silicon
Authors: BENEDETTI A. , BENDER H. , LAUWERS A. , TORREGIANI C. , MAEX K. 
Published: October 2006

SummaryConvergent‐beam electron diffraction on cross‐sectional transmission electron microscopy specimens can map strains in the silicon substrate of microelectronics devices with high spatial resolution. However, at shallow depths below the interface, most of the diffraction lines within a convergent‐beam electron diffraction pattern are split, rendering pattern interpretation impossible in the classic way. The splitting effect was systematically analysed for a variety of materials, and the same qualitative behaviour that can be explained by stress relaxation at the surfaces of the thin transmission electron microscopy specimen was observed. The effects of surface relaxation are modelled by finite elements simulations. The results predict well the experimental magnitude of the splitting for a variety of diffraction lines at different positions below the interface, but fail to simulate the intensity of the secondary lines. Possible reasons for such discrepancies are discussed and assessed.
Structural and mechanical properties of nanocrystalline titanium and 316LVM steel processed by hydrostatic extrusion
Authors: GARBACZ HALINA , LEWANDOWSKA MAŁGORZATA , PACHLA WACŁAW , KURZYDŁOWSKI KRZYSZTOF J. 
Published: October 2006

SummaryThe aim of the present study was to examine the potential of hydrostatic extrusion for the fabrication of high‐strength materials for medical applications. The materials examined were 316LVM steel and technically pure titanium. The microstructures and mechanical properties of the materials before and after hydrostatic extrusion were analysed. It was found that the hydrostatic extrusion process resulted in a substantial refinement of the material microstructures. The refinement of the microstructure was accompanied by an improvement of the mechanical properties, such as the microhardness and yield stress.
High‐temperature dislocation plasticity in the single‐crystal superalloy LEK94
Authors: KOSTKA A. , MÄLZER G. , EGGELER G. 
Published: October 2006

SummaryThe evolution of the dislocation structure that forms during uniaxial creep deformation in the single‐crystal superalloy LEK94 of low density and with Re additions was analysed using transmission electron microscopy. The material has a γ/γ′‐microstructure consisting of γ′‐cubes (L12 phase, 80 vol.%) separated by thin γ‐channels (face‐centred cubic). <100> tensile creep tests were performed at 980 and 1020 °C at stresses of 200 and 240 MPa. The microstructure was investigated at three characteristic stages of creep (directly after loading, at 5% strain and after rupture) to show the evolution of the dislocation structure during high‐temperature creep. It was found that in the early stages of creep, a0/2<011> dislocations form within the γ‐channels. Later on, dislocation networks form and γ′ cutting processes with a0/<001> superdislocations are observed. The results are in line with observations made for other superalloy single crystals in the high‐temperature low‐stress creep regime.
Response of strawberry genotypes to inoculation with isolates of Verticillium dahliae differing in host origin
Authors: Gordon T. R. , Kirkpatrick S. C. , Hansen J. , Shaw D. V. 
Published: October 2006

Eight strawberry genotypes known to differ in susceptibility to verticillium wilt were inoculated with eight isolates of Verticillium dahliae originally obtained from six different host crops: strawberry, potato, watermelon, mint, eggplant (aubergine) and cauliflower. Inoculation experiments were conducted in replicated field trials during two successive years. Known susceptible genotypes developed typical symptoms of verticillium wilt in both years. Although isolates manifested a wide range of aggressiveness, differences were significant only on the most susceptible strawberry genotype. Two isolates originating from strawberry were among the most aggressive of the eight tested, whereas the least aggressive isolate was obtained from cauliflower. Six strawberry genotypes that were regarded as resistant to verticillium wilt based on previous tests were also resistant in the present study, regardless of the isolate used. Overall, strawberry genotypes represented the largest source of variation in these experiments, with variance components approximately 10‐fold greater than those associated with either isolate or the isolate × genotype interaction. The results suggest it should be possible to develop resistance to verticillium wilt in strawberry that is broadly effective against isolates of diverse host origin.
Taxonomy, phylogeny and identification of Botryosphaeriaceae associated with pome and stone fruit trees in South Africa and other regions of the world
Authors: Slippers B. , Smit W. A. , Crous P. W. , Coutinho T. A. , Wingfield B. D. , Wingfield M. J. 
Published: October 2006

Species of Botryosphaeria are well‐recognized pathogens of pome and stone fruit trees. The taxonomy of these fungi, however, has been confused in the past. Recent taxonomic changes to the Botryosphaeriaceae further influence the literature pertaining to these fungi. This study reviews the taxonomic status of Botryosphaeriaceae associated with fruit tree diseases, identifies them in South Africa and elsewhere, and develops a reliable identification technique for them. Comparisons were made using DNA sequence data from the nuclear ITS rRNA operon and anamorph morphology. These analyses distinguished six clades amongst isolates associated with fruit tree diseases, corresponding to Neofusicoccum ribis (= B. ribis), N. parvum (= B. parva), N. australe (= B. australis), B. dothidea, Diplodia mutila (= B. stevensii) and ‘Botryosphaeria’obtusa (the genus Botryosphaeria is no longer available for the fungus known as B. obtusa, but a new name has not been proposed yet). Isolates from fruit trees in South Africa were grouped in the N. australe and ‘Botryosphaeria’ obtusa clades. This is the first report of N. australe from fruit trees. PCR‐RFLP analysis using the restriction endonucleases CfoI and HaeIII distinguished the major clades. However, two groups of closely related species, N. ribis and N. parvum, and N. australe and N. luteum (= B. lutea), had identical RFLP profiles. Using RFLP, it was shown that ‘Botryosphaeria’obtusa is the dominant species on fruit trees in the Western Cape Province of South Africa. These results and methods will be useful in future epidemiological studies and disease management of Botryosphaeriaceae from fruit trees.
A high throughput membrane BIO‐PCR technique for ultra‐sensitive detection of Pseudomonas syringae pv. phaseolicola
Authors: Schaad N. W. , Berthier‐Schaad Y. , Knorr D. 
Published: October 2006

Molecular‐based methods such as PCR have greatly improved detection of bacteria in environmental samples. However, the sensitivity of PCR is not high when compared to agar plating assays, and inhibitors from plants are often a problem. Pre‐enriching bacteria on agar media (BIO‐PCR) can increase the sensitivity of PCR by more than 100% and reduce the effects of inhibitors. To further increase the sensitivity and also reduce the labour needed for BIO‐PCR, a high throughput 96‐well membrane BIO‐PCR technique is described for ultra‐sensitive detection of Pseudomonas syringae pv. phaseolicola (PSP) (syn. P. phaseolicola) in washings of seeds and leaves of Phaseolus vulgaris, using available classical PCR primers and newly designed real‐time primers and probe. The primers and probe, designed from a tox‐argK chromosomal cluster of the PSP‐specific phaseolotoxin gene, were confirmed to be specific to PSP. Samples (1·2 mL) were filtered under vacuum in 96‐well membrane plates. After incubating on soft agar medium for 48–52 h, each well is washed with 200 µL of sterile water and used immediately for nested (two‐step) PCR or real‐time PCR or stored at −20°C. Results of assaying spiked seed washings showed that classical PCR was unable to detect PSP at mean concentrations of 40 colony forming units (cfu) mL−1. BIO‐PCR detected PSP in five out of six samples at 40 mean cfu mL−1 but none at mean concentrations of 4·2 and 0·4 mean cfu mL−1. In contrast, membrane BIO‐PCR detected the bacterium in all six samples tested containing as few as 0·4 mean cfu mL−1. The sensitivity of detection from leaf washings was lower but the results were similar, classical and BIO‐PCR were negative from all three levels of inoculum while membrane BIO‐PCR detected three out of three samples at 80 mean cfu mL−1 and one out of three at 40 mean cfu mL−1.
In‐channel woody vegetation controls on sedimentary processes and the sedimentary record within alluvial environments: a modern example of an anabranch of the River Loire, France
Authors: RODRIGUES S. , BRÉHÉRET J.‐G. , MACAIRE J.‐J. , GREULICH S. , VILLAR M. 
Published: October 2006

AbstractA multidisciplinary approach was used to analyse the role of pioneer trees (Populus nigra) on bar formation in the modern fluvial system of the River Loire (France). Data were collected on seven plots located on a secondary channel, chosen for their vegetation cover and their sedimentary context. Physical features of vegetation, topographical evolution, sediment grain size and flow velocity were investigated during and after floods between 2001 and 2003. Woody vegetation responds morphologically to fast‐flowing waters and sediment deposition. These adaptations influence the role played by trees on local sedimentary processes. Some morphological types of trees exert a strong influence during flood events by deflecting, reducing or increasing the flow energy. As a consequence, the evolution of bedforms, distribution of sediment grain size and slopes are controlled by the flood type, the morphological context (i.e. high‐ or low‐energy zones), the morphology of the vegetated bar and the characteristics of vegetation. Conceptual models are proposed to account for local processes and evolution of tree groves. The first model, which describes the behaviour of groves during a single flood, underlines the sediment deposition downstream of the trees and the trapping of bedload sediments. During the falling stage of the flood, the reorientation of current streams, constrained by both local bed topography and woody vegetation, induces transverse sediment fluxes. For these water levels, the control exerted by trees on small‐scale sedimentary processes becomes significant. The second model shows the evolution of vegetation bands over several flood events. In particular, it describes the influence of vegetation on the fixing and reworking of bedload sediments during the falling limb of the hydrograph. The coalescence of vegetation‐induced bedforms and the resulting morphological changes increase the deflection power of the vegetated bar, inducing the deposition of finer sediments.
Source‐controlled carbonates in a small Eocene half‐graben lake basin (Shulu Sag) in central Hebei Province, North China
Authors: JIANG ZAIXING , CHEN DAIZHAO , QIU LONGWEI , LIANG HONGBIN , MA JUN 
Published: October 2006

AbstractCarbonate deposits, which unconformably overlie the Palaeozoic bedrocks, extensively occur in the base of the Tertiary lake succession in the half‐graben Shulu Sag, central Hebei Province, North China. This study focuses on the basal carbonate successions on the hinged western slope. Based on seismic, borehole and core data, nine facies are identified in the carbonate successions, and are further grouped into five facies associations: mid‐proximal alluvial fan, distal alluvial fan, fan fringe, moderately deep lake and deep lake. The first two facies associations constitute alluvial fans formed by debrisflows at the edge of lake and are dominated by mounded‐ to lobate‐shaped, matrix‐ to clast‐supported carbonate rudstones with minor calcretes in the lowermost rudstone units and basinward increase in interfingering with lacustrine carbonate facies. The fan fringe, moderately deep lake and deep lake associations are dominated by pebbly carbonate arenites (or rare carbonate arenites), calcisiltite‐calcilutites, and varve‐like calcilutites, calcareous shales and oil shales, respectively. Widespread occurrences of fine‐grained limestone packages containing varve‐like organic‐rich laminations, minor authigenic glauconite and pyrite, and planktonic and plant fossils suggest a meromictic, anoxic deep lake under a semi‐humid to humid climate, probably with a connection to marine basins. Similarities in lithology and fossil assemblages (e.g. trilobites) of lithoclasts with those of the Mid‐Upper Cambro‐Ordovician bedrock carbonates suggest that the clastic and dissolved carbonate loads were sourced from this Lower Palaeozoic catchment, and shed off the surrounding highlands into the basin. These carbonate facies associations represent the lake lowstand and transgressive deposits of the basal third‐order sequence (Ia) in which the highstand deposits are composed of lacustrine siliciclastics. During the lake lowstand stage (or initiation of basin‐filling) under an intermediate climate, carbonate alluvial fans occurred mostly subaerially at the bottom of the hinged slope with a narrow, shallow lake zone basinwards, and locally were perched within the palaeovalley on the mid‐upper slope. During the transgressive (deepening) stage under a semi‐humid to humid climate, carbonate alluvial fans became smaller in size and episodically stepped backwards upon the slope, with greatly expanded and deepened lake. Nevertheless, the carbonate system was switched to an exclusively siliciclastic system during the highstand stage. The exhumation and erosion of the Mid‐Lower Cambrian bedrock dominated by siliciclastics was probably the cause due to further uplift of the drainage basin. All these facts indicate that the carbonate deposition in the Shulu Sag was mostly controlled by the interactions of tectonics, climate and provenance.
Deposition and diagenesis of carbonate conglomerates in the Kremenara anticline, Albania: a paragenetic time marker in the Albanian foreland fold‐and‐thrust belt
Authors: BREESCH LIESBETH , SWENNEN RUDY , DEWEVER BEN , MEZINI AJET 
Published: October 2006

AbstractThis paper addresses the diagenesis of carbonate conglomerates in that it assesses the potential of conglomerates in refining the paragenetic history in complex structural areas, such as the Albanian foreland fold‐and‐thrust belt. Of major interest are stylolites (burial and tectonic) which are restricted to conglomerate fragments or which crosscut the conglomerate matrix. Based on the inferred age of stylolite development in relation to burial, uplift and tectonic history, and the Lower to Middle Miocene age of the conglomerates, the succession of diagenetic events was subdivided into several stages. The Poçem polymict transgressive carbonate conglomerate (Kremenara anticline, central Albania) was deposited in a shallow marine environment. These conglomerates are covered by intertidal rhodolithic packstones–grainstones. The stable‐isotope signature of these packstones–grainstones (δ18OV‐PDB = −1·0 to +0·7‰; δ13C = +1·0 to +1·4‰) plots is within the range of marine Early and Middle Miocene values. Shortly after deposition of the conglomerates, micritization, geopetal infill and acicular calcite cementation took place. A first calcite vein generation is interpreted as having formed from a Messinian brine during shallow burial. Burial stylolites developed during further burial in the Pliocene. These stylolites serve as an important diagenetic time marker. The post‐burial stylolite meteoric calcite vein cement probably precipitated during the following telogenetic stage. Karstification and calcite concretion precipitiation pre‐date overturning of the western limb of the anticline. Reopening of subvertical fractures and tectonic stylolites in the western limb of the Kremenara anticline, followed by oil migration, represents one of the latest diagenetic events. These fractures and stylolites provide major pathways for hydrocarbon production.
Limitations of sequence stratigraphic correlation between marine and continental deposits: a 3D experimental study of unconformity‐bounded units
Authors: MILANA JUAN PABLO , TIETZE KLAUS‐WERNER 
Published: October 2006

AbstractExperiments have been carried out in a model basin 16 × 1·2 × 0·9 m to address the effect of base‐level and discharge changes on actively growing alluvial‐shoreline wedges. Two distinct types of erosive surfaces were investigated: one produced by base‐level fluctuations in the coastal zone and the other by discharge and supply fluctuations in the upstream alluvial basin. In the first experiment, three similar base‐level cycles were simulated keeping sediment supply and basin tilting constant within each cycle, and changing discharge from one cycle to the next. In the second experiment, rises and falls of base level were instantaneous and discharge changes were in phase (high discharge linked to high water levels in the basin). In the third experiment, base level and discharge changed gradually, at different rates and they were out of phase, resembling a typical glacio‐eustatic cycle in which sea‐level rises and falls are linked to increased and decreased discharge, respectively. The resulting stratigraphy of the alluvial to deltaic sedimentary wedge was analysed in terms of the development of unconformities and the evolving depositional geometry. An intervening decoupled zone between parts of the model basin dominated by alluvial processes and that at the coastal zone is identified. Within this decoupled zone, unconformities in the alluvial succession tend to vanish basinward, and base‐level generated coastal unconformities disappear landward. The two types of unconformity can be generated at different times during a glacio‐eustatic cycle, and it is thus erroneous to correlate them, even though they may appear to form a continuous surface. Unconformities within the modelled stratigraphy do not constitute time lines nor do they consistently separate younger from older beds, as they require a significant time to form and they have thick sedimentary packages as depositional correlatives. The experiments also support a fourfold division of sequences, showing the development of a significant sedimentary package during base‐level falls.
Arabidopsis heat shock transcription factor A2 as a key regulator in response to several types of environmental stress
Authors: Nishizawa Ayako , Yabuta Yukinori , Yoshida Eriko , Maruta Takanori , Yoshimura Kazuya , Shigeoka Shigeru 
Published: October 2006

SummaryWe isolated 76 high‐light and heat‐shock (HL + HS) stress‐inducible genes, including a putative heat‐shock transcription factor (HsfA2), by suppression‐subtractive hybridization from Arabidopsis. The transcript level of HsfA2 was significantly increased under the several stress conditions or by the H2O2 treatment. Furthermore, the induction of HsfA2 expression was highest among those of other class A HSFs in response to HL + HS stress conditions. The promoter assay revealed that HsfA2 is induced mainly in rosette leaves under HL + HS stress conditions. In the HsfA2‐overexpressing Arabidopsis (Pro35S:HsfA2) plants, 46 genes, including a large number of heat‐shock proteins, ascorbate peroxidase 2 and galactinol synthase 1 and 2, were highly expressed compared with those in the wild‐type plants. The transcript levels of the HsfA2 target genes are highly correlated with those of HsfA2 in the Pro35S:HsfA2 plants. The transcript levels of the HsfA2 target genes, as well as HsfA2 transcripts, were induced by treating with exogenous H2O2. In the knockout HsfA2 Arabidopsis plants, the induction of 26 HsfA2 target genes was strongly reduced for up to 2 h under HL + HS stress conditions. Furthermore, the Pro35S:HsfA2 plants showed increased tolerance to combined environmental stresses. Our present results indicate that HsfA2 is a key regulator in the induction of the defence system under several types of environmental stress.
Aurora kinase is required for chromosome segregation in tobacco BY‐2 cells
Authors: Kurihara Daisuke , Matsunaga Sachihiro , Kawabe Akira , Fujimoto Satoru , Noda Masanori , Uchiyama Susumu , Fukui Kiichi 
Published: October 2006

SummaryPost‐translational modifications of core histone tails play crucial roles in chromatin structure and function. Although phosphorylation of Ser10 and Ser28 (H3S10ph and H3S28ph) of histone H3 is ubiquitous among eukaryotes, the phosphorylation mechanism during the cell cycle remains unclear. In the present study, H3S10ph and H3S28ph in tobacco BY‐2 cells were observed in the pericentromeric regions during mitosis. Moreover, the Aurora kinase inhibitor Hesperadin inhibited the kinase activity of Arabidopsis thaliana Aurora kinase 3 (AtAUR3) in phosphorylating both Ser10 and Ser28 of histone H3 in vitro. Consistently, Hesperadin inhibited both H3S10ph and H3S28ph during mitosis in BY‐2 cells. These results indicate that plant Aurora kinases phosphorylate not only Ser10, but also Ser28 of histone H3 in vivo. Hesperadin treatment increased the ratio of metaphase cells, while the ratio of anaphase/telophase cells decreased, although the mitotic index was not affected in Hesperadin‐treated cells. These results suggest that Hesperadin induces delayed transition from metaphase to anaphase, and early exit from mitosis after chromosome segregation. In addition, micronuclei were observed frequently and lagging chromosomes, caused by the delay and failure of sister chromatid separation, were observed at anaphase and telophase in Hesperadin‐treated BY‐2 cells. The data obtained here suggest that plant Aurora kinases and H3S10ph/H3S28ph may have a role in chromosome segregation and metaphase/anaphase transition.