bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of evening vs morning thyroxine ingestion on serum thyroid hormone profiles in hypothyroid patients
Authors: Bolk Nienke , Visser Theo J. , Kalsbeek Andries , Van Domburg Ron T. , Berghout Arie
Published: October 2006

Objective   Standard drug information resources recommend that l‐thyroxine be taken half an hour before breakfast on an empty stomach, to prevent interference of its intestinal uptake by food or medication. We observed cases in which TSH levels improved markedly after changing the administration time of l‐thyroxine to the late evening. We therefore conducted a pilot‐study to investigate whether l‐thyroxine administration at bedtime improves TSH and thyroid hormones, and whether the circadian rhythm of TSH remains intact.

Design   Patients were studied on two occasions: on a stable regimen of morning thyroxine administration and two months after switching to night‐time thyroxine using the same dose. On each occasion patients were admitted for 24 h and serial blood samples were obtained.

Patients   We investigated 12 women treated with l‐thyroxine because of primary hypothyroidism, who used no medication known to interfere with l‐thyroxine uptake.

Measurements  Patients were admitted to hospital and blood samples were obtained at hourly intervals for 24 h via an indwelling catheter. Following this first hospital admission, all women were asked to switch the administration time from morning to bedtime or vice versa. After 2 months they were readmitted for a 24‐h period of hourly blood sampling. Blood samples were analysed for serum TSH (immunometric assay), FT4 and T3 (competitive immunoassay), T4 and rT3 (radioimmunoassay), serum TBG (immunometric assay) and total protein and albumin (colourimetric methods).

Results   A significant difference in TSH and thyroid hormones was found after switching to bedtime administration of l‐thyroxine. Twenty‐four‐hour average serum values amounted to (mean ± SD, morning vs bedtime ingestion): TSH, 5·1 ± 0·9 vs 1·2 ± 0·3 mU/l (P < 0·01); FT4, 16·7 ± 1·0 vs 19·3 ± 0·7 pmol/l (P < 0·01); T3, 1·5 ± 0·05 vs 1·6 ± 0·1 nmol/l (P < 0·01). There was no significant change in T4, rT3, albumin and TBG serum levels, nor in the T3/rT3 ratio. The relative amplitude and time of the nocturnal TSH surge remained intact.

Conclusions   l‐thyroxine taken at bedtime by patients with primary hypothyroidism is associated with higher thyroid hormone concentrations and lower TSH concentrations compared to the same l‐thyroxine dose taken in the morning. At the same time, the circadian TSH rhythm stays intact. Our findings are best explained by a better gastrointestinal uptake of l‐thyroxine during the night.
Grass overseeding and a fungus combine to control Taraxacum officinale
Authors: ABU‐DIEYEH MOHAMMED H. , WATSON ALAN K.
Published: October 2006

Common dandelion Taraxacum officinale is the most abundant and frequent weed within turfgrass in temperate climates. With increasing legislation banning herbicide & non‐chemical means of control are needed replace phenoxy herbicides. The weediness of T. officinale is mainly the result of high seed production, dispersal and germination potential. A successful long‐term weed control strategy should suppress established plants, exert negative effects on seed production and prevent seedling establishment.

The potential of Sclerotinia minor to cause T. officinale seed mortality and reduce seedling emergence without impact on turfgrass species was evaluated in greenhouse and field experiments.

A pre‐emergence application of S. minor at the time of seeding and a post‐emergence application at 10 days after seeding significantly reduced T. officinale emergence to 17% and 2%, respectively, compared with 70–80% germination in the untreated control. There were no adverse effects of direct S. minor contact on turfgrass seed germination, seedling emergence or seedling establishment.

Grass overseeding alone did not improve grass quality or reduce T. officinale population densities in a low‐maintained lawn environment. When S. minor was combined with grass overseeding, at application or 10 days after application, a 70–80% reduction of the T. officinale population occurred in the first year, increasing to 95% in the following year in the absence of further treatments. Turfgrass appearance and quality significantly and continuously improved up to 80%, compared with 10–20% in the control plots. Densities of other weeds, white clover Trifolium repens and field bindweed Convolvulus arvensis, were also significantly reduced when S. minor was applied with grass overseeding compared with the bioherbicide alone.

Synthesis and applications. We have demonstrated that S. minor reduces seed numbers, seedlings and establishment of T. officinale and, when combined with grass overseeding, the grass sward flourishes and weed emergence and colonization are significantly reduced. Other broadleaf weeds are susceptible to S. minor and thus this bioherbicide could have utility in no‐till maize, cereal grain and grass seed production systems, where producers are searching for non‐chemical weed control.
Evaluating feathermoss growth: a challenge to traditional methods and implications for the boreal carbon budget
Authors: BENSCOTER BRIAN W. , VITT DALE H.
Published: October 2006

Accurate assessment of net primary production is vital for understanding carbon (C) cycling, both regionally and globally. However, this requires effective methods of measurement that acknowledge the unique characteristics of the subject or area being monitored.

Feathermosses dominate the ground layer of boreal upland ecosystems and play a vital role in soil C accumulation, accounting for up to 50% of total photosynthesis. Feathermoss growth is both apical and lateral, with branches of determinate length at maturity produced at consistent frequencies along the stem.

Traditional methods of estimating annual production of feathermosses underestimate total plant production because they do not account for lateral growth of the previous year's immature branches. We present a conceptual model of feathermoss growth using Pleurozium schreberi that includes apical and lateral annual growth. From this model, we provide a modified method to more accurately estimate P. schreberi production. The top 3 cm of 10 P. schreberi plants from each of five bog peatlands in Alberta, Canada, were collected. For each plant, distance from the stem apex to branch insertion, branch length and dry mass, and dry mass of 3‐mm stem sections were measured and used to define model parameters that, due to lack of significant variability among the sites, can be applied regionally and possibly globally throughout the boreal zone. An additional 20 plants were collected from a sixth site for testing the accuracy of our modified method.

Assessment of our method showed an insignificant mean difference between observed and calculated production values. Furthermore, comparison of our method with traditional methods showed a c. 25% underestimation of annual production by the latter. Traditional methods underestimate annual biomass production of P. schreberi by c. 73 g m−2, accounting for more than 14 Tg C year−1 across the boreal region.

Our study shows that accounting for species‐specific growth characteristics when estimating ground layer production has a substantial impact on boreal C budget assessments and therefore the terrestrial C cycle.
Local structure studies of Fe‐Nb‐B metallic glasses using electron diffraction
Authors: HIRATA A. , HIROTSU Y. , OHKUBO T. , MATSUBARA E. , MAKINO A.
Published: October 2006

Local atomic structures in Fe84Nb7B9 and Fe70Nb10B20 amorphous alloys were examined by means of electron diffraction with the help of computer calculation. Electron diffraction patterns were taken by using energy‐filtered transmission electron microscopy (TEM) to eliminate inelastic scattering. We constructed structure models with 5000 atoms fitting to experimental interference functions. Voronoi polyhedral analyses were performed for the obtained final structure models. Local atomic structures of the alloys were closely related to those of the crystalline phases that appeared on annealing. A difference of stability of two amorphous phases was discussed on the basis of structure models.
Well‐orientated cubic boron nitride nanocrystals as studied by high‐resolution transmission electron microscopy
Authors: TSIAOUSSIS I. , FRANGIS N.
Published: October 2006

In 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

The 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

Convergent‐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

The 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

The 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.
Activity, release and flow of digestive enzymes in the cricket, Gryllus bimaculatus
Authors: WOODRING JOSEPH , HOFFMANN KLAUS H. , LORENZ MATTHIAS W.
Published: October 2006

Abstract In the cricket Gryllus bimaculatus, proventricular pressure forces a nutrient fluid from the ground food‐brei through a sieve at the base of the caecae, and the combination of secreted enzymes and water causes a rapid inflation of the caecae on the first day after imaginal ecdysis. The ceacal region of the midgut is the primary site for the secretion of digestive enzymes. Proteases and amylase flow from the caecae into the mostly empty crop on day 1, and carbohydrate and protein digestion starts as soon as food is present (6 h). Thereafter, much of the amylase activity (but not protease) in the crop is synthesized and released by the crop tissues themselves. Regurgitating proteases and amylases from the caecae into the crop after day 1 is most likely accomplished by temporarily halting proventricular peristalsis and allowing the caecal muscles to contract, forcing caecal contents, including enzymes, forward. The total activity of digestive enzymes in the caecae is virtually identical in 2‐day‐old fed and unfed females, indicating little or no secretagogue (prandial) regulation of enzyme secretion. Most of the digestive enzymes in the ventricular endoperitrophic space may originate from the mucus dragged from the caecae. Lipase activity is low in all gut regions in both starved and fed females. Head ligation or injection of trypsin modulating oostatic factor, allatostatin A or B fails to indicate any involvement of nerves or hormones in the release of digestive enzymes in the caecae. Gryllus bimaculatus appears to secrete digestive enzymes continuously, and a considerable loss of enzymes may occur at certain times through egestion.
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

A 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

Carbonate 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

This 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

Experiments 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

We 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

Post‐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.
Over‐expression of OsAGAP, an ARF‐GAP, interferes with auxin influx, vesicle trafficking and root development
Authors: Zhuang Xiaolei , Jiang Jiafu , Li Junhua , Ma Qibin , Xu Yunyuan , Xue Yongbiao , Xu Zhihong , Chong Kang
Published: October 2006

Development and organogenesis in both dicot and monocot plants are highly dependent on polar auxin transport (PAT), which requires the proper asymmetric localization of both auxin influx and efflux carriers. In the model dicot plant Arabidopsis thaliana, the trafficking and localization of auxin efflux facilitators such as PIN‐FORMED1 (PIN1) are mediated by GNOM, a guanine‐nucleotide exchange factor (GEF) for the ADP‐ribosylation factor (ARF) family of small GTPases, but molecular regulators of the auxin influx facilitators remain unknown. Here, we show that over‐expression of OsAGAP, an ARF‐GTPase‐activating protein (ARF‐GAP) in rice, impaired PAT and interfered with both primary and lateral root development. The lateral root phenotype could be rescued by the membrane‐permeable auxin 1‐naphthyl acetic acid, but not by indole 3‐acetic acid (IAA) or by 2,4‐dichloro‐phenoxyacetic acid, which require influx facilitators to enter the cells. OsAGAP‐over‐expressing plants had alterations in vesicle trafficking and localization of the presumptive A. thaliana auxin‐influx carrier AUX1, but not in the localization of the auxin efflux facilitators. Together, our data suggest that OsAGAP has a specific role in regulating vesicle trafficking pathways such as the auxin influx pathway, which in turn controls auxin‐dependent root growth in plants.
Proteomic and transcriptomic analysis of Arabidopsis seeds: molecular evidence for successive processing of seed proteins and its implication in the stress response to sulfur nutrition
Authors: Higashi Yasuhiro , Hirai Masami Yokota , Fujiwara Toru , Naito Satoshi , Noji Masaaki , Saito Kazuki
Published: October 2006

Seed storage proteins are synthesized as sources of carbon, nitrogen and sulfur for the next generation of plants. Their composition changes according to nutritional conditions. Here, we report the precise molecular identification of seed proteins by proteomic analysis of wild‐type Arabidopsis thaliana and methionine‐over‐accumulating mutant mto1‐1 plants. The identities of 50 protein spots were determined in the protein extract of mature Arabidopsis seeds by two‐dimensional (2D) gel electrophoresis and subsequent mass spectrometric analysis. Of these protein spots, 42 were identified as derived from 12S globulins or 2S albumins. These results indicate that approximately 84% of protein species in Arabidopsis seeds are derived from a few genes coding for 12S globulins and 2S albumins. Extensive mass spectrometric analysis of the 42 spots revealed that successive C‐terminal degradation occurred on the 12S globulins. The feasibility of this C‐terminal processing was rationalized by molecular modeling of the three‐dimensional structure of 12S globulins. The C‐terminal degradation at glutamic acid residues of the 12S globulin subunits was repressed under sulfur‐deficient conditions. Transcriptome analysis was combined with proteomic analysis to elucidate the mechanism of changes in seed protein composition in response to sulfur deficiency. The results suggest that seed storage proteins in Arabidopsis undergo multi‐layer regulation, with emphasis on post‐translational modifications that enable the plant to respond to sulfur deficiency.
A mutation in an Arabidopsis ribose 5‐phosphate isomerase reduces cellulose synthesis and is rescued by exogenous uridine
Authors: Howles Paul A. , Birch Rosemary J. , Collings David A. , Gebbie Leigh K. , Hurley Ursula A. , Hocart Charles H. , Arioli Tony , Williamson Richard E.
Published: October 2006

The Arabidopsis radial swelling mutant rsw10 showed ballooning of root trichoblasts, a lower than wild‐type level of cellulose and altered levels of some monosaccharides in non‐cellulosic polysaccharides. Map‐based cloning showed that the mutated gene (At1g71100) encodes a ribose 5‐phosphate isomerase (RPI) and that the rsw10 mutation replaces a conserved glutamic acid residue with lysine. Although RPI is intimately involved with many biochemical pathways, media supplementation experiments suggest that the visible phenotype results from a defect in the production of pyrimidine‐based sugar–nucleotide compounds, most likely uridine 5′‐diphosphate–glucose, the presumed substrate of cellulose synthase. Two of three RPI sequences in the nuclear genome are cytoplasmic, while the third has a putative chloroplast transit sequence. The sequence encoding both cytoplasmic enzymes could complement the mutation when expressed behind the CaMV 35S promoter, while fusion of the RSW10 promoter region to the GUS reporter gene established that the gene is expressed in many aerial tissues as well as the roots. The prominence of the rsw10 phenotype in roots probably reflects RSW10 being the only cytosolic RPI in this tissue and the gene encoding the plastid RPI being relatively weakly expressed. We could not, however, detect a decrease in total RPI activity in root extracts. The rsw10 phenotype is prominent near the root tip where cells undergo division, endoreduplication and cell expansion and so are susceptible to a restriction in de novo pyrimidine production. The two cytosolic RPIs probably arose in an ancient duplication event, their present expression patterns representing subfunctionalization of the expression of the original ancestral gene.
Trafficking of the human transferrin receptor in plant cells: effects of tyrphostin A23 and brefeldin A
Authors: Ortiz‐Zapater Elena , Soriano‐Ortega Esther , Marcote María Jesús , Ortiz‐Masiá Dolores , Aniento Fernando
Published: October 2006

Plant cells possess much of the molecular machinery necessary for receptor‐mediated endocytosis (RME), but this process still awaits detailed characterization. In order to identify a reliable and well‐characterized marker to investigate RME in plant cells, we have expressed the human transferrin receptor (hTfR) in Arabidopsis protoplasts. We have found that hTfR is mainly found in endosomal (Ara7‐ and FM4‐64‐positive) compartments, but also at the plasma membrane, where it mediates binding and internalization of its natural ligand transferrin (Tfn). Cell surface expression of hTfR increases upon treatment with tyrphostin A23, which inhibits the interaction between the YTRF endocytosis signal in the hTfR cytosolic tail and the μ2‐subunit of the AP2 complex. Indeed, tyrphostin A23 inhibits Tfn internalization and redistributes most of hTfR to the plasma membrane, suggesting that the endocytosis signal of hTfR is functional in Arabidopsis protoplasts. Co‐immunoprecipitation experiments show that hTfR is able to interact with a μ‐adaptin subunit from Arabidopsis cytosol, a process that is blocked by tyrphostin A23. In contrast, treatment with brefeldin  A, which inhibits recycling from endosomes back to the plasma membrane in plant cells, leads to the accumulation of Tfn and hTfR in larger patches inside the cell, reminiscent of BFA compartments. Therefore, hTfR has the same trafficking properties in Arabidopsis protoplasts as in animal cells, and cycles between the plasma membrane and endosomal compartments. The specific inhibition of Tfn/hTfR internalization and recycling by tyrphostin A23 and BFA, respectively, thus provide valuable molecular tools to characterize RME and the recycling pathway in plant cells.
Workload and main activities of consultative ICU nurses: long‐term experience in a large teaching hospital in the Netherlands
Authors: Top W. M. C. , Schultz M. J. , Jurrjens F. H. , Rommes J. H. , Spronk P. E.
Published: October 2006

Background:  Early recognition and prompt treatment of deteriorating patients outside the intensive care unit (ICU) improves hospital survival. Over the past decade, consultative services have been implemented in many institutions. This service is frequently performed by ICU nurses, while little information is available on the workload and type of activities these ICU nurses actually perform.

Methods:  In 1995, a consultative ICU nurse‐driven service was introduced in a large teaching hospital in the Netherlands. In this descriptive study, we determined types of consultation, time consumed per visit, and main interventions during these activities.

Results:  During the study period, 9144 consultations in 4365 patients were performed. While the number of ‘scheduled’ visits (visits of patients after discharge from the ICU) was reasonably variable during the study period, the number of ‘on demand’ visits (visits demanded by non‐ICU personnel) increased gradually, especially during the first years. At the end of the observation period, approximately half of the visits were ‘on demand’ in the non‐ICU wards. The mean number of consultations per patient dropped gradually over the whole period, from 4.02 in 1996 to 1.54 in 2004. The total workload was approximately half an hour per day; visits were combined with regular activities of the ICU team. Tracheal suctioning was among the most frequent activities during consultation (approximately 90% of all visits).

Conclusion:  Consultative ICU nurses play a growing role in bridging the gap between the ICU and non‐ICU departments in our hospital. Workload is acceptable.
A Test of the Links between Family Interference with Work, Job Enrichment and Leader–Member Exchange
Authors: Lapierre Laurent M. , Hackett Rick D. , Taggar Simon
Published: October 2006

Nous avons testé l’hypothèse selon laquelle le degré d’interférence entre la vie familiale et le travail (FIW) chez des sujets “suiveurs” varie en fonction de la qualité de la relation leader‐suiveur dans le monde du travail (Qualité LMX) et de leur niveau de valorisation du travail. La relation entre ce niveau et la qualité LMX a aussi étéévaluée. Si le FIW, en accord avec les résultats relatifs à la théorie de l’échange social, est lié négativement, et à la qualité LMX, et au niveau de valorisation du travail des suiveurs, ce dernier est corrélé positivement à la qualité LMX conformément aux prédictions principales de la théorie LMX. Cependant, bien que le FIW se rapporte directement au niveau de valorisation du travail, nous avons pu montrer qu’il est lié indirectement à la qualité LMX par le truchement du niveau de valorisation du travail.

We tested whether followers’ frequency of family interference with work (FIW) relates to the quality of the leader–follower work relationship (LMX quality), and to followers’ reported level of job enrichment. We also tested the relationship between followers’ job enrichment and LMX quality. We found that that FIW relates negatively to LMX quality and to job enrichment, supporting arguments based on social exchange theory, and that followers’ job enrichment relates positively to LMX quality, supporting one of the key predictions of LMX theory. We also found that while FIW relates directly to job enrichment, it relates only indirectly to LMX quality through job enrichment.
The Effect of Learning vs. Outcome Goals on Self‐Efficacy, Satisfaction and Performance in an MBA Program
Authors: Latham Gary P. , Brown Travor C.
Published: October 2006

Dans cette expérience de terrain, on applique la théorie de la fixation des objectifs au sentiment d’efficacité personnelle d’étudiants, à leur satisfaction envers le programme du MBA aussi bien qu’à leur performance (GPA). Immédiatement après leur avoir fixé des objectifs spécifiques élevés, nous avons mesuré le sentiment d’efficacité personnelle des étudiants en MBA. Celui des étudiants de la condition “objectifs de résultats pour la fin de l’année” (long terme) était inférieur à celui de sujets qui étaient dans la condition “faites de votre mieux” ou dans celle “but d’apprentissage”. Les sujets présentant des difficultés spécifiques en ce qui concerne les buts d’apprentissage sont plus satisfaits du programme MBA que ceux des autres conditions expérimentales. Le GPA était significativement plus élevé dans la condition “but d’apprentissage” que dans celle “but de performance”à long terme. Les sujets qui ont des objectifs à court terme et un objectif de résultat à long terme ont un GPA plus élevé que ceux qui ont seulement un objectif à long terme ou que ceux qui sont dans l’urgence de faire de leur mieux. Les implications de ces résultats pour la théorie et la pratique sont discutées.

The present field experiment examined the application of goal setting theory on student self‐efficacy, satisfaction with the MBA program, as well as performance (i.e. GPA). Immediately after setting specific high goals, the self‐efficacy of MBA students who set year end (distal) outcome goals was lower than participants in either the “do your best” or the learning goal conditions. Participants who set specific difficult learning goals had higher satisfaction with the MBA program than those in other experimental conditions. GPA was significantly higher in the learning goal condition relative to the distal performance goal condition. Participants who set proximal goals, in addition to a distal outcome goal, had a higher GPA than those who only set a distal goal or those who were urged to do their best. Implications of these findings for theory and practice are discussed.
Female Proclivity to the World of Business
Authors: Constant Amelie
Published: October 2006

This paper investigates entrepreneurial women confronted with the self‐employment or business career choice. Optimistic women have a higher proclivity to be businesswomen. Businesswomen select self‐ over paid employment when they are young or old, less educated, married or with under‐age children. There are no significant native‐immigrant differences. However, among immigrant women those who are in Germany 6 to 12 years are more likely to go into self‐employment. These results show that women in Germany who are in their prime working age, educated, not married, and with no under‐age children are less likely to choose self‐employment, as it is not viewed as a channel to achieving higher socio‐economic standing.
R&D and Firm Performance in a Transition Economy
Authors: Czarnitzki Dirk , Kraft Kornelius
Published: October 2006

We estimate the effects of R&D on firms' credit ratings and on financial distress. The main purpose is the comparison of firms in Western Germany and Eastern Germany as a transitional economy. Innovative activity has a positive impact on firm value proxied by ratings in Western Germany, but a negative impact in Eastern Germany. We also consider future financial distress, and find that R&D in Eastern German firms leads to higher default risk. This stands in contrast to Western Germany where R&D enhances future performance. This result is highly politically relevant, since the high level of subsidies present in Eastern Germany may be subject to misallocation.