bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biochemical and molecular characterization of Bacillus amyloliquefaciens, B. subtilis and B. pumilus isolates with distinct antagonistic potential against Xanthomonas campestris pv. campestris
Authors: Wulff E. G. , Mguni C. M. , Mansfeld‐Giese K. , Fels J. , Lübeck M. , Hockenhull J. 
Published: March 2003

Fifty‐one Bacillus isolates were characterized by fatty acid methyl ester (FAME) analysis; universal primer polymerase chain reaction (UP‐PCR) fingerprinting; production of secondary metabolites and antagonistic activity against Xanthomonas campestris pv. campestris (causal agent of black rot in cabbage) in vitro and in vivo. Based on FAME analysis and/or PCR fingerprinting, the isolates were clustered into three different groups, named as Bacillus amyloliquefaciens, B. subtilis and B. pumilus. Seed treatment with Bacillus spp. generally reduced germination of seeds and incidence of black rot, but no relationship was found between the results of in vitro and in vivo experiments. The B. amyloliquefaciens group contained isolates that were generally the most effective at reducing attack of black rot in vivo. The metabolic profiles of these isolates suggested that they produced surfactin, iturin, bacillomycine and/or azalomycin F. Isolates belonging to the B. subtilis group were mostly able to synthesize surfactin and arthrobactin. Surfactin, amphomycin, arthrobactin and valinomycin were generally found in culture extracts of isolates belonging to the B. pumilus group. No effect on growth of the pathogen was detected when the activity of filtered culture extracts and selected metabolites produced by the three different Bacillus species was tested in vitro against X. c. pv. campestris. However, inhibition was seen when bacterial liquid cultures were used. When the ability to colonize cabbage endophytically was examined for seven selected isolates with different antagonistic potential against black rot, it was found that the ability was related to the species and not to the antagonistic activity of the isolates.
Transfer of Macrophage‐Derived Mycobacterial Antigens to Dendritic Cells Can Induce Naïve T‐Cell Activation
Authors: Girvan A. , Aldwell F. E. , Buchan G. S. , Faulkner L. , Baird M. A. 
Published: March 2003

AbstractMycobacteria are capable of surviving and replicating in host macrophages, where they can release antigenic material into the environment. However, unlike dendritic cells (DCs), macrophages do not appear to be capable of activating naïve T cells. Therefore, this work investigated antigen transfer between macrophages and DCs. We generated culture supernatants from bacille Calmette–Guérin (BCG)‐infected and uninfected macrophages and then determined whether DCs could present these extracellular mycobacterial antigens to T cells. Here, we show that DCs pulsed with antigens released from BCG‐infected macrophages can stimulate primed T cells in vitro and initiate naïve T‐cell responses in vivo. These results suggest that antigen transfer can occur between macrophages and DCs.
Umbilical Cord Mannan‐Binding Lectin and Infections in Early Childhood
Authors: Kielgast S. , Thiel S. , Henriksen T. B. , Bjerke T. , Olsen J. , Jensenius J. Chr. 
Published: March 2003

AbstractTo investigate whether mannan‐binding lectin (MBL) in umbilical cord blood (UCB) is associated with the incidence rate of hospitalizations for infections during early childhood. A follow‐up study from birth to 31 months of age, with endpoint data from the Danish National Hospital Discharge Registry. The concentration of MBL and immunoglobulin A (IgA) in UCB was measured in a time‐resolved immunofluorometric assay. Information on possible confounding factors was obtained from questionnaires completed by mothers during their pregnancy, and characteristics of the child at birth were registered by a midwife on a structured coding sheet. A total of 2104 infants born in the period between 1 February 1990 and 25 May 1991 to mothers living in the municipality of Aarhus. Concentration of MBL and IgA in UCB, gestational age, birth weight, number of siblings less than 3 years old, mother's smoking habits, alcohol and coffee consumption, educational and marital status and previous spontaneous abortions and stillbirths. Of 2104 children, 626 were hospitalized at least once, and 346 of these were hospitalized with infection. The hazard ratio (HR) of hospitalization with infections in children with low levels of MBL (<120 ng/ml) was 1.4 (95% confidence interval (CI), 1.0–1.8), which was similar to our findings on hospitalization because of other diseases. The HR of hospitalization for viral infections was 2.8 (CI, 1.3–5.9). Low levels of MBL in UCB were associated with hospitalization in general and particularly with hospitalization for viral infections.
Carbonate sediment transport pathways based on foraminifera: case study from Frank Sound, Grand Cayman, British West Indies
Authors: Li Chun , Jones Brian , Kalbfleisch William B.C. 
Published: March 2003

Foraminifera can be used to determine the source(s) of carbonate sediment and the directions of sediment transport in shallow, coastal lagoons such as Frank Sound on the south‐central coast of Grand Cayman. These determinations, based on the distribution of foraminiferal assemblages and ‘tracer species’ (numerically abundant species that live in known physiographic units and/or ecological conditions), show that the lagoonal sediments are a mixture of grains that originated in the lagoon and forereef. The variable proportions of these foraminifera throughout the lagoon reflects the dynamic processes that control lagoonal sedimentation.Amphistegina gibbosa, Discorbis rosea, and Asterigerina carinata lived in the forereef environment. The fact that these ‘tracer species’ are found throughout Frank Sound and in the beach sands, shows that they were transported across the reef crest and the lagoon. Abrasion‐resistant Archaias angulatus, a‘tracer species’ indicative of a lagoonal setting, forms up to 50% of foraminiferal assemblages found in the lagoonal sediments. Preferential winnowing of small tests from these populations indicates sorting under high energy conditions. The vertical distribution of the forereef and lagoonal foraminifera in the sediment blanket that covers the floor of Frank Sound indicates that these processes are temporally persistent.Transportation of forereef foraminifera into and around the lagoon and sorting of the lagoonal foraminifera cannot take place under ‘normal’ conditions when the tranquil lagoon is characterized by weak currents. Storms and/or hurricanes, however, generate short‐lived high‐energy events that can move and sort the sediment and foraminifera. At the height of a storm, water and sediment are moved over the reef and then piled and held onshore by the onshore winds and the constant flow of water over the reef and across the lagoon. These currents can mix some of the lagoonal and forereef sediments. As a storm wanes, however, the ‘piled water’ flows offshore via strong rip currents that pass into the ocean through the channels which transect the reef. These currents winnow and/or strip sediment from the lagoon and may transport lagoonal sediments into the forereef area. As a result, residual lagoonal sediment is commonly characterized by larger and abrasion‐resistant foraminifera.
On the efficiency of vertical array aeolian field traps
Authors: RASMUSSEN KELD R. , MIKKELSEN HARALD E. 
Published: March 2003

The efficiency of three vertical array field traps for measuring the distribution of aeolian mass transport with height was compared with measurements with an isokinetic trap. The vertical traps seem to work adequately (efficiency > 80%) at heights greater than ≈15 mm above the bed. Closer to the bed, however, the open array trap catches about 70%, the two continuous arrays only about 50%. Because most of the transport takes place close to the surface, the overall efficiency of the field traps ranges from 50 to 70%.Based on these wind tunnel tests, we have developed a low single‐compartment wedge‐shaped trap. Its shape, in combination with flow straighteners at the entrance, minimizes stagnation effects, so that the efficiency is ≈80%. Our data indicate that with the wedge trap used in combination with the vertical array Aberdeen trap, we can sample mass transport in the field during periods with unidirectional winds with an overall efficiency of the order of 80%.
Diagenesis of the Newark Rift Basin, Eastern North America
Authors: TABAKH  , SCHREIBER  
Published: March 2003

Late Triassic nonmarine strata in the Newark Rift Basin, eastern North America, accumulated in a subsiding half‐graben prior to opening of the Atlantic Ocean. These strata consist, in ascending order, of the Stockton, Lockatong, and Passaic formations. Although different in specific lithology, these formations all exhibit diagenetic fabrics dominated by authigenic albite and analcime. These same minerals have a similar presence in Late Triassic (Newark Supergroup) strata of other rift‐related basins to the north, suggesting that related authigenesis is not simply a result of local diagenetic factors.The basal deposit, the Stockton Formation, is composed of fluvial sandstones and overbank mudstones, with nodular pedogenic calcite (calcrete). During burial, original micrite was first recrystallized into sparry calcite and then later subjected to partial replacement by authigenic albite, which is also present as overgrowths and void fillings in overbank mudstones. The Lockatong Formation contains organic‐rich shales, carbonates, and evaporative mudstones deposited under cyclic conditions in laterally extensive lacustrine environments. Analcime comprises up to 40% of these strata by volume, occurring within the matrix, as a replacement of original carbonates and evaporites, and as fillings in macrovoids. The overlying Passaic Formation is made up of massive red mudstones, evaporites, and local calcareous lacustrine sequences. Evaporites are replaced by coarse‐grained anhydrite together with some authigenic albite.A central question concerns the source for the Na, Si, and Al required for albite and analcime authigenesis. It is suggested that, in addition to alteration of primary siliciclastic material, sodium in particular was supplied in two ways: (1) from high concentrations in original evaporative brines and groundwaters (Lockatong and Passaic formations); and (2) from dissolution of associated sodium‐bearing evaporites (Lockatong and Passaic Formation) during diagenesis. It is proposed here that basin‐sourced, Na‐enriched brines circulated through the section over time. As albite is more stable at elevated temperatures relative to analcime, it developed in the lowermost strata of the basin (Stockton Formation). Analcime is more prevalent in the overlying Lockatong Formation.
Continental margin sedimentation, with special reference to the north‐east Atlantic margin
Authors: Weaver Philip P. E. , Wynn Russell B. , Kenyon Neil H. , Evans Jeremy 
Published: March 2003

SummaryThe north‐east Atlantic continental margin displays a wide range of sediment transport systems with both along‐slope and down‐slope processes. Off most of the north‐west African margin, south of 26°N, upwelling produces elevated accumulation rates, although there is little fluvial input. This area is subject to infrequent but large‐scale mass movements, giving rise to debris flows and turbidity currents. The turbidity currents traverse the slope and deposit thick layers on the abyssal plains, while debris flows deposit on the continental slope and rise. From the Atlas Mountains northwards to 56°N, the margin is less prone to mass movements, but is cut by a large number of canyons, which also funnel turbidity currents to the abyssal plains. The presence of a lithospheric plate boundary off SW Iberia is believed to have led to high rates of sediment transport to the deep sea. Even larger quantities of coarse sediments have fed the canyons and abyssal plains in the Bay of Biscay as a result of drainage from melting icecaps. Bottom currents have built sediment waves off the African and Iberian margins, and created erosional furrows south of the Canaries. The Mediterranean outflow is a particularly strong bottom current near the Straits of Gibraltar, depositing sand waves and mud waves in the Gulf of Cadiz. North of 56°N, the margin is heavily influenced by glacial and glaciomarine processes active during glacial times, which built glacial trough‐mouth fans, such as the North Sea Fan, and left iceberg scour marks on the upper slope and shelf. Over a long period, especially during interglacials, this part of the margin has been greatly affected by along‐slope currents, with less effect by turbidity currents than on the lower latitude margins. Large‐scale mass movements are again a prominent feature, particularly off Norway and the Faeroes. Some of these mass movements have occurred during the Holocene, although high glacial sedimentation rates may have contributed to the instability.
Holocene storage of siliciclastic sediment around islands on the middle shelf of the Great Barrier Reef Platform, north‐east Australia
Authors: Heap A. D. , Dickens G. R. , Stewart L. K. , Woolfe K. J. 
Published: March 2003

ABSTRACTThick sequences of sediment surround the Whitsunday Islands on the middle shelf of the Great Barrier Reef (GBR) Platform. Much of this sediment is siliciclastic material deposited since the sea‐level highstand at around 6·5 ka. This raises a mass balance dilemma because modern terrigenous discharge to the GBR Platform is restricted to the inner shelf. Shallow seismic profiles and sediment samples were collected over 450 km2 around the Whitsunday Islands to quantify the mass of siliciclastic sediment for a dynamic model of the shelf. The sea floor and pre‐Holocene surfaces were mapped using 4584 stations along the seismic profiles and a graphical computer program. The total volume of sediment between these two surfaces is 3·67 ± 0·45 × 109 m3. This volume is composed of buried reefs (0·13 ± 0·01 × 109 m3), medium‐ (0·70 ± 0·30 × 109 m3) and fine‐grained shoals (2·84 ± 0·35 × 109 m3). The volume estimates combined with measurements of carbonate concentration, density and porosity indicate that 1850 ± 380 Mt of Holocene siliciclastic sediment surround the Whitsunday Islands in medium‐ (510 ± 225 Mt) and fine‐grained shoals (1340 ± 155 Mt). The total mass of siliciclastic material is 1·7–2·6 times that stored in Cleveland Bay, a similar sized repository on the inner shelf. A simple numerical model has been constructed to explain this large quantity of Holocene siliciclastic sediment. The model results in the appropriate siliciclastic mass next to the Whitsunday Islands by integrating regional shelf processes over time. Unlike the present day, rivers discharged sediment to the middle shelf during the early Holocene. This material was subsequently focused by northward transport into the vicinity of the islands, a geomorphologically complex region that serves as a sediment trap. Although direct riverine inputs to the middle shelf have stopped during the present sea‐level highstand, previously deposited siliciclastic sediment is continually being winnowed from the middle shelf and redeposited next to the Whitsunday Islands. The transport and distribution of siliciclastic sediment on the GBR Platform is thus influenced significantly by storage around islands on the middle shelf.
Phylogeny of the bee genus Lasioglossum (Hymenoptera: Halictidae) based on mitochondrial COI sequence data
Authors: Danforth Bryan N. 
Published: March 2003

SummaryThe bee genus Lasioglossum Curtis is a model taxon for studying the evolutionary origins of and reversals in eusociality. This paper presents a phylogenetic analysis of Lasioglossum species and subgenera based on a data set consisting of 1240 bp of the mitochondrial cytochrome oxidase I (COI) gene for seventy‐seven taxa (sixty‐six ingroup and eleven outgroup taxa). Maximum parsimony was used to analyse the data set (using
paup*4.0) by a variety of weighting methods, including equal weights, a priori weighting and a posteriori weighting. All methods yielded roughly congruent results. Michener’s Hemihalictus series was found to be monophyletic in all analyses but one, while his Lasioglossum series formed a basal, paraphyletic assemblage in all analyses but one. Chilalictus was consistently found to be a basal taxon of Lasioglossum sensu lato and Lasioglossum sensu stricto was found to be monophyletic. Within the Hemihalictus series, major lineages included Dialictus + Paralictus, the acarinate Evylaeus + Hemihalictus + Sudila and the carinate Evylaeus + Sphecodogastra. Relationships within the Hemihalictus series were highly stable to altered weighting schemes, while relationships among the basal subgenera in the Lasioglossum series (Lasioglossum s.s., Chilalictus, Parasphecodes and Ctenonomia) were unclear. The social parasite of Dialictus, Paralictus, is consistently and unambiguously placed well within Dialictus, thus rendering Dialictus paraphyletic. The implications of this for understanding the origins of social parasitism are discussed.
Phylogeny of Prosciara Frey and related genera (Diptera: Sciaridae)
Authors: Vilkamaa Pekka 
Published: March 2003

SummaryThe phylogeny of Phytosciara Frey, Prosciara Frey, Dolichosciara Tuomikoski (together forming Phytosciara sensu Tuomikoski), Lobosciara Steffan and Bradysia Winnertz was studied by parsimony analysis using the computer programs Pee‐Wee and NONA. The analysis was based on sixty‐four morphological characters from adult males, coded for thirty‐nine ingroup and two outgroup terminals. Three cladograms of the maximum fit (Pee‐Wee) and one of the minimum length (NONA) were obtained, some of them with polytomies. Many characters showed much homoplasy in the cladograms. The solution by the fittest cladograms was chosen as the main hypothesis of the phylogeny. Of the groups studied, only Lobosciara appeared monophyletic. The relationships of the taxa in their now revised monophyletic sense are: Dolichosciara + (Lobosciara + ((‘Prosciara’ fuscina group + ‘P’. vulcanata) + (‘P’. mima group + ((‘P’. perfida + (Bradysia + Phytosciara)) + Prosciara)))). Phytosciara Frey, Prosciara, Dolichosciara and Lobosciara in their revised concepts are regarded as genera.
Morphological and molecular identity of Anopheles (Cellia) sundaicus (Diptera: Culicidae), the nominotypical member of a malaria vector species complex in Southeast Asia
Authors: Linton Yvonne‐Marie , Harbach Ralph E. , Seng Chang Moh , Anthony Thomas G. , Matusop Asmad 
Published: March 2003

SummaryA neotype for Anopheles (Cellia) sundaicus (Rodenwaldt), the nominotypical member of a malaria vector species complex, is selected from the progeny of a female collected at Pandan Beach near Lundu, Sarawak, Malaysia. Siblings of the neotype and other topotypic specimens are used to characterize and fix the morphological and molecular identity of the species as a foundation for systematic studies of the species complex. The species is described and illustrated in the adult, pupal and larval stages, and DNA sequence data are included for the mitochondrial cytochrome c oxidase I (COI) gene and the nuclear ITS‐2 region.
Physical and mechanical properties of selected amphibolite core samples from the Kola Superdeep Borehole KSDB‐3
Authors: Trčková Jiřina , Živor Roman , Přikryl Richard 
Published: March 2003

ABSTRACTLaboratory tests of physical and mechanical properties were performed on amphibolites representing two units from the Kola Superdeep Borehole KSDB‐3 (Russia) − the Proterozoic Karelian Complex (depths of 3043 m, 3530 m and 4389 m) and the Archean Kola–Belomorian Complex (depths of 7951 m, 8942 m and 9904 m). Obtained grain density and bulk density values are nearly identical for all tested samples, but porosities increased slowly with depth. Marked differences in strength properties were found between amphibolite samples from the Karelian Complex and amphibolite samples from the Kola–Belomorian Complex. The uniaxial compressive strength of the samples from the lower part of the borehole is significantly smaller than in samples from the upper part; a similar trend was found for triaxial tests. The values of the deformation modulus, Young's modulus and Poisson's ratio obtained from samples of the Karelian Complex are considerably higher than those from the Kola–Belomorian Complex. Observed mechanical properties are explained by the variable grain‐size distribution and by the spatial arrangement of main rock‐forming minerals. These properties are also influenced by recovery of rocks from great depths.
Isolation and molecular characterization of PosF21, an Arabidopsis thaliana gene which shows characteristics of a b‐Zip class transcription factor.
Authors: Aeschbacher RA , Schrott M , Potrykus I , Saul MW 
Published: March 2003

SummaryWe have isolated a putative transcription factor gene, PosF21, from Arabidopsis thaliana using an indirect cross‐hybridization approach. cDNA clones were isolated which encode single repeating amino acids. Such sequences may function as activation domains in transcription factors and may be indicative for such proteins. The clone PosF21 encodes a region very rich in glutamines. Besides this putative activation domain it encodes a protein sequence which shows all the characteristics of a basic‐domain/leucine zipper type of DNA‐binding domain. PosF21 is expressed constitutively at a low level in young seedlings and in roots, stems and leaves of mature Arabidopsis plants. A genomic clone of PosF21 was isolated and the gene structure was analyzed. Related sequences in Arabidopsis and a wide range of other plants were detected using the putative DNA‐binding domain as a probe in cross‐hybridization experiments. Transient transformations in tobacco protoplasts were performed using the beta‐glucuronidase (GUS) gene as reporter gene. Approximately 400 bp of the 5' genomic region of PosF21 promote expression of the GUS gene in tobacco protoplasts. Evidence for a regulatory function of PosF21 was obtained since co‐ expression of the full PosF21 protein or its DNA‐binding region alone specifically stimulated GUS gene expression directed from the PosF21 promoter by 6‐8‐fold.
Inhibition of tobacco nitrite reductase activity by expression of antisense RNA
Authors: Vaucheret Hervé , Kronenberger Jocelyne , Lepingle Andrée , Vilaine Françoise , Boutin Jean‐Pierre , Caboche Michel 
Published: March 2003

SummaryA tobacco nitrite reductase (NiR) cDNA and its corresponding gene were isolated from cDNA and genomic libraries. An NiR antisense mRNA was expressed in transgenic tobacco under the control of a double 35S promoter. Transformants were obtained on a medium containing ammonium as the sole source of nitrogen. One plant growing normally on ammonium but displaying drastically reduced development and chlorotic leaves when grown on nitrate as the sole source of nitrogen was studied further. This plant accumulated nitrite fivefold over wild‐type level and showed reduced amounts of ammonium (11% wild‐type level), glutamine (19%), and total protein (8%). NiR mRNA and activity were below detectable levels. Under these conditions, nitrate reductase (NR) activity and mRNA were overexpressed, suggesting that N‐metabolites resulting from nitrate reduction are responsible for the repression of the expression of the NR gene, independently from the presence or absence of a functional NR protein.