bluuebunny/crossref_metadata_2025 huggingface dataset:
Histoplasma capsulatum Inhibits Apoptosis and Mac‐1 Expression in Leucocytes
Authors: MEDEIROS A. I. , BONATO V. L. D. , MALHEIRO A. , DIAS A. R. V. , SILVA C. L. , FACCIOLI L. H.
Published: March 2003

Histoplasma capsulatum
is a fungus found intracellularly in neutrophils and peripheral blood mononuclear cells (PBMCs), suggesting that it is capable of evading damage and survives inside these cells. In this study, we report that neutrophils from
H. capsulatum
‐infected mice, and human neutrophils and mononuclear cells exposed to
H. capsulatum
presented less apoptosis than those from noninfected animals or cells exposed to medium only. Moreover, cells harvested from infected animals are resistant to apoptosis induced by dexamethasone – a proapoptotic stimulant. We also show that neutrophils harvested from infected mice and PBMCs from humans exposed to the fungus had a greatly decreased Mac‐1 expression. We conclude that
H. capsulatum induces an antiapoptotic state on leucocytes, which correlates with decreased cell‐surface Mac‐1 expression. These facts may represent an escape mechanism for the fungus by delaying cell death and allowing the fungus to survive inside leucocytes.
IL‐18 Production in Human Pulmonary and Pleural Tuberculosis
Authors: Song C.‐H. , Lee J.‐S. , Nam H.‐H. , Kim J.‐M. , Suhr J.‐W. , Jung S.‐S. , Na M.‐J. , Paik T.‐H. , Kim H.‐J. , Park J.‐K. , Jo E.‐K.
Published: March 2003

Interleukin‐18 (IL‐18) has multiple important pro‐inflammatory effects, including the induction of interferon‐γ (IFN‐γ) in various diseases. In this study, we investigated the IL‐18‐producing activities in human pulmonary and pleural tuberculosis (TB) in response to purified protein derivative (PPD) antigen (Ag) from Mycobacterium tuberculosis. The most significant IL‐18 production was found in chronic refractory TB (CRTB) patients. However, IFN‐γ production in CRTB patients was significantly less than that in healthy tuberculin reactors or in patients with tuberculous pleurisy (TBP). Elevated levels of both IL‐18 and IFN‐γ were found in pleural fluids from TBP patients. In vitro production of IL‐18 was dramatically decreased following an 18 h stimulation with PPD. However, IFN‐γ was markedly increased in pleural mononuclear cells from TBP patients after in vitro stimulation with PPD. The mesothelial cell type was the main source of pro‐IL‐18 in pleural cells from TBP patients, suggesting an important role for these cells in TBP. Taken together, these data indicate that IL‐18 is elevated in peripheral blood mononuclear cells from CRTB patients, as well as at the site of TBP, indicating a possible role for IL‐18 in both protective immunity and pathologic responses in human TB.
Linkage Relationships of Genes Coding for α2‐Macroglobulin, C3 and C4 in the Zebrafish: Implications for the Evolution of the Complement and Mhc Systems
Authors: SAMONTE I. E. , SATO A. , MAYER W. E. , SHINTANI S. , KLEIN J.
Published: March 2003

The α2‐macroglobulin (A2M) and the complement components C3 and C4 are related proteins derived from a common ancestor. Theoretically, this derivation could have occurred either by tandem duplications of their encoding genes or by polyploidization involving chromosomal segments, a chromosome or the whole genome. In tetrapods the A2M‐, C3‐ and C4‐encoding genes are generally each located on a different chromosome. This observation has been interpreted as supporting their origin by polyploidization. We identified and mapped (with the help of a radiation hybrid panel of cell lines) the A2M, C3 and C4 loci in the zebrafish, Danio rerio. Each of the three types of loci is present in the zebrafish in multiple copies, but all of the identified copies of a given type map to the same region in linkage groups 1 (C3) and 15 (A2M, C4). The A2M and C4 loci are mapped in the same region not linked to any of the class I or class II major histocompatibility complex (Mhc) loci. These observations are interpreted as supporting the origin of the A2M family of genes by tandem duplications, followed by the dispersal of the copies to different chromosomes. It is also argued that the association of C4 with the class I/II loci in tetrapods is accidental and without functional significance.
Analysis of the Relationship Between Mannose‐Binding Lectin (MBL) Genotype, MBL Levels and Function in an Australian Blood Donor Population
Authors: Minchinton R. M. , Dean M. M. , Clark T. R. , Heatley S. , Mullighan C. G.
Published: March 2003

The mannose‐binding lectin (MBL) pathway of complement activation is an important component of innate host defence. Numerous studies have described associations between the MBL genotype, MBL levels and disease susceptibility. However, genotyping and quantitative assays used in these studies have frequently been limited, and comprehensive data examining the interaction between structural and coding MBL genetic variants, MBL antigenic levels and MBL functional activity are lacking. Such data may be important for accurate planning and interpretation of studies of MBL and disease. This study has examined MBL in a cohort of 236 Australian blood donors. Five MBL promoter and coding single nucleotide polymorphisms were genotyped using polymerase chain reaction–sequence‐specific priming (PCR–SSP). Plasma levels of MBL antigen were quantified using a double‐antibody enzyme‐linked immunosorbent assay (ELISA), and functional MBL levels were quantified using a mannan‐binding assay. Activation of the complement pathway by MBL was measured in a C4‐deposition assay. Significant associations were found between both coding and promoter polymorphisms and MBL antigenic and functional levels. There was significant correlation between the results of MBL double‐antibody, mannan‐binding and C4‐deposition assays. Comprehensive MBL genotyping and functional MBL quantitation using mannan‐binding and C4‐deposition assays have the potential to be highly informative in MBL disease association studies.
Late Pleistocene aeolian and fluvial interactions in the development of the Nizzana dune field, Negev Desert, Israel
Authors: HARRISON  , YAIR
Published: March 2003

The interdunal areas in the Nizzana linear sand dune field contain both sandy and silty sediments. A series of trenches was excavated across the interdunal corridor exposing stacked sequences of silty and sandy units which are locally restricted to palaeodepressions. The silty units contain fining upward sequences and are interpreted as overbank deposits from the Nahal Nizzana. Thermoluminescence dating and identification of buried palaeosols indicates that the silt and clay layers were deposited over a period of several thousands of years in the late Pleistocene. The sands between the silt layers have been fluvially reworked and are not primary aeolian deposits. The stacked sequences of fluvial deposits indicate that the palaeodepressions persisted in the landscape for a significant time attesting to long‐term stability of the interdunal areas. It also suggests that the linear dunes themselves have not moved laterally during this time despite climatic changes and devegetation. Since the end of the late Pleistocene the Nahal Nizzana has downcut and overbank deposition no longer occurs within the interdunal corridors. The playa deposits today are positive relief features indicating that topographic inversion has occurred and that the interdunal areas are geomorphically active.
Origin of Dinantian zebra dolomites south of the Brabant‐Wales Massif, Belgium
Authors: NIELSEN P. , SWENNEN R. , MUCHEZ PH. , KEPPENS E.
Published: March 2003

Zebra dolomites, characterized by a repetition of dark grey (a) and light (b) coloured dolomite sheets building up abbabba‐sequences, occur in Dinantian strata from deep boreholes (> 2000 m) south of the Brabant‐Wales Massif in Belgium. These zebra dolomite sequences are several tens of metres thick. The dark grey dolomite sheets (a) consist of non‐planar crystals, 80–150 μm in diameter. These crystals display a mottled red–orange luminescence and are interpreted to be replacive in origin. The white dolomite sheets (b) consist of coarse crystalline nonplanar b1 dolomite, which evolves outwards into transparent saddle shaped b2 dolomite. The b1 dolomites possess a mottled red–orange luminescence similar to the a dolomites, while the saddle shaped b2 rims display red to dark brown luminescent‐zones. The b1 dolomites are possibly partly replacive and partly cavity filling. Their b2 rims display criteria typical for a cement origin. Locally, cavities exist between two succeeding white dolomite sheets. These cavities make up ≈5% of the zebra rocks and are locally filled by saddle shaped ankerite and/or xenomorphic ferroan calcite.

Geochemical and fluid inclusion data (Th ≈ 120 °C) indicate a burial diagenetic origin for these zebra dolomites. The a and b1 dolomites are characterized by similar geochemical compositions and fluid inclusion data pointing toward a related origin. To explain the development of the zebra textures, suprahydrostatic pressures in conjunction with late Variscan tectonic compression are invoked. A model involving dolomitizing fluids expelled during the Variscan orogeny is proposed. An overpressured system is also invoked to explain the important porosity development, the creation of centimetre‐scale subvertical displacements of the zebra pattern and the microfractures affecting the b1–b2 dolomite crystals.
Preservation of cross‐sets due to migration of current ripples over aggrading and non‐aggrading beds: comparison of experimental data with theory
Authors: Storms Joep E. A. , Dam Remke L. Van , Leclair Suzanne F.
Published: March 2003

An experimental study of the preservation of cross‐sets during the migration of current ripples under aggrading and non‐aggrading conditions was conducted in order to test the modified Paola–Borgman theory for distribution of cross‐set thickness as a function of distribution of bed‐wave height. In a series of flume experiments, the geometry and migration characteristics of the ripples did not vary systematically with aggradation rate and are comparable to other flume and river data.

Mean cross‐set thickness/mean formative bed‐wave height is less than 0·4, and mean cross‐set thickness/mean bed‐wave height is less than 0·53. In the present experiments, the primary control of cross‐set thickness is the variability of ripple height. Aggradation rate accounts for only 1–7% of the total cross‐set thickness.

A two‐parameter gamma density function was fitted to histograms of ripple height to determine the value of parameter a needed for the modified Paola–Borgman model. This model underestimates cross‐set thickness because of its assumption that bed‐form height spreads evenly above and below the mean bed level, which is not the case in reality. Mean cross‐set thickness is predicted quite well if the model constant is increased to 1·3.
Namurian bentonites in the Pennine Basin, UK – origin and magmatic affinities
Authors: SPEARS  , KANARIS‐SOTIRIOU  , RILEY  , KRAUSE
Published: March 2003

Nine Namurian clay bands retrieved from boreholes in the northern part of the Pennine Basin are, on the basis of their petrography, mineralogy and geochemistry, shown to be volcanic in origin and are therefore bentonites. The bentonites, which have a fragmental texture, are normally graded and show rare preservation of shard textures, representing vitric tuff deposits that have been altered subsequently to clay‐dominated horizons. Crystals are a minor component of the bentonites, but biotite, in particular, is concentrated at the base of the beds. A clay mineral assemblage of mixed‐layer illite–smectite with subordinate kaolinite identifies most of the samples as K‐bentonites, but kaolinite dominates two samples that can be classed as tonsteins. Temporal variation of salinity within the depositional basin is suggested to explain these different clay assemblages. The major element geochemistry of the bentonites reflects their clay mineralogy and the compositions of diagenetic minerals present, the latter including pyrite, carbonates and hydroxyapatite. Enrichment of the bentonites in some trace elements (including Ba, Sr, Pb, Cu and Ni) can be related to the presence of the diagenetic minerals, but the extent to which the elements are added from external sources as opposed to being redistributed within the ash is unclear. Immobile trace element systematics suggest a rhyodacite/dacite composition for the original ash and derivation from the collision of plates, this being supported by evidence provided by the rare earth elements (REE) in one group of samples. However, in another group of samples, variations in REE concentrations may be caused by mobility of these elements during alteration. The chemistry of the Namurian bentonites contrasts markedly with that of the local Carboniferous volcanics but is comparable, in some respects, with one group of Westphalian tonsteins, although the latter are more rhyolitic in character. It is suggested that the Namurian bentonites and the Westphalian tonsteins of acid affinities originated from volcanic activity associated with a destructive plate margin in the Variscan externides and that the observed compositional trend may reflect magma evolution possibly related to the progressive east–west closure.
A Lower Cretaceous clastic slope succession, Livingston Island, Antarctica: sand‐body characteristics, depositional processes and implications for slope apron depositional models
Authors: Lomas Simon A.
Published: March 2003

The early Cretaceous fill of the forearc/intra‐arc Byers Basin includes a 600‐ to 900‐m‐thick interval of marine slope apron deposits, the President Beaches Formation. This is a predominantly argillaceous succession within which coarser‐grained deposits are largely confined to lenticular packages of low width–thickness ratios. The entire formation was deposited in mid‐ to late‐Berriasian times, coincident with a pulse of regional arc expansion, at minimum mean accumulation rates of 120–225 mm 1000 years–1. The mudstones are finely laminated, with a restricted benthic macrofauna and minimal bioturbation, indicating relatively inhospitable sea‐floor environments. Sand‐rich packages occur as 7‐ to 30‐m‐thick channel‐fill units composed chiefly of classical medium‐grained turbidites, in some cases associated with complex high‐concentration turbidity current deposits and minor mud‐rich debrites. These sand‐bodies are apparently elongate along (normal to) the NW‐facing palaeoslope implied by slump‐fold axes (and the strike of the volcanic arc). Similarly, palaeocurrent indices show a consistent arc‐parallel, NE‐directed trend, suggesting that transport processes were strongly influenced by the structural ‘grain’ of the irregular slope morphology. Slope instability is recorded by widespread slump and soft‐sediment collapse features promoted by a combination of steep sea‐floor gradients and relatively high rates of sedimentation. A lack of systematic vertical facies trends indicates that this was not a progradational or well‐organized system, despite high rates of sediment supply. However, the strong systematic relationship between palaeocurrents and palaeoslope suggests a promising basis for evaluating organization in otherwise poorly ordered slope apron depositional systems.
Deposition and early alteration of evaporites
Authors: Schreiber B. Charlotte , Tabakh Mohamed El
Published: March 2003

The depositional settings for primary and early diagenetic evaporite deposits generally fall into three categories: marginal (mixed shallow‐subaqueous and subaerial), shallow and deep subaqueous. These three environmental groupings hold for both marine and nonmarine settings, although the details of continental evaporites may be far more complex than in most marine‐fed water bodies. The primary evaporite morphologies from many continental (playa), hypersaline marine and marine‐marginal depositional settings are reasonably well understood, because of the numerous detailed studies of recent, Holocene and Cenozoic deposits that serve as models for sedimentary interpretation. The sedimentological features that develop in deeper water settings are inferred, based on examination of unaltered Cenozoic deposits. Each environmental setting develops characteristic depositional features and patterns, and one facies grades into the next. Because there may be significant physiochemical changes in water composition during deposition as well as sudden change(s) in both water depth and basinal circulation, description and interpretation of evaporative rocks should not be based on mineralogy alone, but on the distinct sedimentary characteristics of each part of a deposit. In cases where sediments still reflect their primary mineralogy and morphology, most of the environments can now be recognized; however, geochemical studies are commonly required to determine the source(s) of the original water. The determinative geochemical techniques that presently serve as a support to sedimentologic study include studies of fluid inclusions, bromine content of chloride salts, and the stable isotopes of strontium, sulphur, carbon and oxygen. Only after these and perhaps other chemical analyses are considered can the full depositional history of a region be reasonably unravelled.
Boundary layer dynamics and drag reduction in flows of high cohesive sediment suspensions
Authors: Li Michael Z. , Gust
Published: March 2003

Drag reduction has been observed in suspension flows of low clay concentrations in previous studies. Here, velocity profiles and bed shear stresses, expressed as shear velocities, are measured using epoxy‐coated hot‐film sensors to evaluate drag reduction and controlling factors in suspension flows of high clay concentrations (4 and 8 g l–1). The directly measured shear velocity in the viscous sublayer is found to be reduced by as much as 70% relative to the profile‐derived shear velocity in the logarithmic layer. Drag reduction is found to increase with increasing clay concentration and decreasing flow strength. Density profile data indicate that the suspension flows were not stratified, and examinations of particle size distributions suggest that flocculation was not significant in causing the observed drag reduction. Measurements of the velocity profiles and of the shear velocity in the viscous sublayer indicate significant thickening of the inner wall layer and show turbulence damping in the viscous sublayer. These effects become stronger for higher concentrations and lower flow strength, suggesting that they are responsible for drag reduction in flows of clay suspension. Empirical relationships have been derived that can be used to predict the magnitude of drag reduction and the reduced shear stress in mud suspensions for both laboratory and field cohesive sediment transport studies.
Visualization of wave‐induced suspension patterns over two‐dimensional bedforms
Authors: Villard Paul V. , Osborne Philip D.
Published: March 2003

High spatial and temporal resolution measurements of suspended sand concentration (c) over vortex ripples were collected with a three‐transducer acoustic backscatter sensor (ABS) array, under irregular `natural' waves in a multidirectional wave basin. These measurements permit two‐dimensional visualization of the movement of sediment‐laden vortices over an individual vortex ripple under a series of waves. Patterns of sediment motion were tracked through consecutive zero‐crossings in the horizontal velocity (U) record measured at 0·05 m above the ripple crest elevation. It was possible to trace the advection of individual sediment‐laden vortices at the zero‐crossings. During 73% of these events, shedding and advection of coherent suspension events occurred before the flow reversal associated with the zero‐crossing. This may be caused by the bedforms retarding the near‐bed flow inducing the eddy shedding before the zero‐crossing. While at maxima in U, secondary suspension events with low c were observed to pass over the ripple crest moving with U measured at 0·05 m. This pattern is attributed to vortex shedding from adjacent bedforms and/or antecedent suspension events. The most energetic events appeared to persist for several wave cycles and reached heights of ≈0·20 m. These suspension events appeared to be more persistent when smaller waves follow larger waves, possibly as a result of weaker reversals in vorticity. Although the events appeared to be vertically coherent in the time series from the individual transducers, it is apparent through visualization that these events are associated with the pairing of antecedent and developing vortices.
Anatomy of a transgressive lag: Panther Tongue Sandstone, Star Point Formation, central Utah
Authors: Hwang In‐Gul , Heller Paul L.
Published: March 2003

Abstract The Panther Tongue of the Star Point Formation in central Utah contains a variety of transgressive lag deposits that, when mapped regionally, show a sensitive dependence upon pre‐existing topography of the palaeoshoreline. The Panther Tongue consists of a coarsening‐upward sandstone wedge that prograded into the Western Interior Seaway during Late Cretaceous (Santonian) time. High‐resolution sequence stratigraphic analysis revealed that this member was deposited during the long‐distance (>50 km) regression and transgression of a delta into shallow‐marine environments, containing basal highstand, forced regression, lowstand and transgressive systems tracts. Based on grain size, clast composition, lateral extent and stratigraphic position, the coarse sandstones on top of the Panther Tongue were classified into four types: (1) simple; (2) dispersed; (3) oxidized; and (4) local lags. The simple lag is composed of dark grey coarse sandstone with oyster fragments and shark teeth. This lag is typically extensively bioturbated and massive. Laminated and cross‐bedded units are also common. This type of coarse sandstone is interpreted as a typical transgressive lag. The dispersed lag differs in that it contains abundant mud and commonly occurs as multiple beds in thick intervals of muddy sandstone. Mixing of bay/estuarine and shallow‐marine mud with simple lag sand may be responsible for deposition of this type of coarse sandstone. The oxidized lag is distinctive in its reddish colour with extensive bioturbation and is commonly overlain by a simple lag. The local lag is composed of thin‐bedded, dark grey, coarse sandstone, occurring locally between the mouth bar and distributary channel. The variation in types, grain size and bed thickness of the coarse‐grained lags was mainly controlled by antecedent topography as suggested by immediately underlying lithofacies. Relatively thick (≈30 cm) simple lags are present on top of mouth‐bar sandstones, whereas dispersed lags are common on top of the distributary channel sandstone and in bay/estuarine and shallow‐marine mudstones. Erosion of topographic highs (mouth bar) resulted in relatively thick accumulation of simple lags. In topographic low areas such as distributary channel, estuary, bay and shallow‐marine environments, fine‐grained muddy sands that were eroded from the nearby topographic highs were redeposited. Intermittent storm waves transported coarse sands both landward and seaward, forming a dispersed lag. The net effect was reworking of local topographic relief during overall transgression, forming an apparently planar transgressive surface of erosion.
Revision of the genus Xylomoia Staudinger (Lepidoptera: Noctuidae), with descriptions of two new species
Authors: MIKKOLA KAURI
Published: March 2003

Seven species are included in the genus Xylomoia Staudinger, two of which are new: X. retinax sp.n. from the Novosibirsk area, Western Siberia, and from the Chelyabinsk area, southern Ural Mountains, and X. stangelmaieri sp.n. from Caorle, Venezia Giulia, on the Adriatic coast. A North American species, Chortodes didonea (Smith) comb.n., is removed from the genus. According to a cladistic analysis, the genus Xylomoia comprises one plesiomorphic species group, the chagnoni group, and two apomorphic groups: the graminea and strix groups. The latter are exclusively temperate Palaearctic. Xylomoia chagnoni (Barnes & McDunnough) is the only Nearctic species of the genus, and the loosely related X. apameaoides (Hacker) was recently described from Turkey. In geographical isolation, these two species have retained many ancestral features. In the more central area, the common ancestor of the graminea and strix groups has evolved into at least five species. The locality and rarity of the species of Xylomoia seemingly result from adaptation of the species to moist habitats, the larvae probably bore inside grass stems (the case of X. chagnoni). What are called lock‐and‐key mechanisms may lead to the use of non‐independent character states in a cladistic analysis; particularly in the case of homoplasy this kind of double‐weighting may result in erroneous cladograms. In Xylomoia, deleting female lock‐and‐keys affected only the number of cladograms produced, whereas omitting the corresponding male characters had profound effects on the cladogram.
Revision of the Neotropical ant subfamily Leptanilloidinae
Authors: Brandão C. R. F. , Diniz J. L. M. , Agosti D. , Delabie J. H.
Published: March 2003

Abstract. The rare Neotropical ant subfamily Leptanilloidinae is revised and its internal phylogeny and biogeography discussed. A new genus, Asphinctanilloides gen.n., including three new species, A. amazona, A. anae and A. manauara, and three new species of Leptanilloides, L. improvisa, L. legionaria and L. sculpturata are described. The only previously known species of the subfamily, L. biconstrictaMann (1923), is redescribed, and the larva of L. legionaria sp.n. is described. Keys to the genera and the species, and a phylogeny of the group are provided. Emphasis has been placed on the study of abdominal and sting characters.
Redescription and re‐evaluation of the Burmese amber psychodid Eophlebotomus connectens Cockerell and its phylogenetic position (Diptera: Psychodidae)
Authors: Duckhouse D. A.
Published: March 2003

Eophlebotomus is re‐examined, with the discovery of important new features and colleagues that were inaccurately described by previous workers. Hennig's scheme deriving the venation of Horaiella from that of Eophlebotomus could equally well have used a trichomyiine or a sycoracine as the starting point and therefore does not specifically support the hypothesis that Horaiella is the sister group. The phlebotomine‐like features of Eophlebotomus are plesiomorphies mostly also occurring in Sycoracinae, but there are also several synapomorphies supporting a particular relationship between Eophlebotomus and Sycoracinae or Trichomyiinae or both. It is hypothesized that Eophlebotomus represents a basal offshoot of the lineage leading to Sycoracinae and Trichomyiinae.
Cladistic analysis of Coenosiini (Diptera: Muscidae: Coenosiinae)
Authors: Couri Márcia S. , Pont Adrian C.
Published: March 2003

The phylogenetic relationships among world genera of Coenosiini (Diptera: Muscidae: Coenosiinae) were investigated using parsimony. The analysis involved forty‐six ingroup terminal taxa, representing 100% of the genera currently assigned to this tribe, three outgroups and sixty‐seven adult male and female morphological characters. The monophyly of Coenosiini is confirmed by the position of the three katepisternal bristles, equidistant from each other and placed at the points of an equilateral triangle. Genera Andersonosia, Agenamyia, Anthocoenosia, Drepanocnemis, Pachyceramyia and Rhabdotoptera are removed from Coenosiini and temporarily placed in Limnophorini. The other genera fall into two groups: the Lispocephala‐group, comprised of genera with mainly Old World species and the Nearctic genus Pentacricia; and the Coenosia‐group, with the highest level of generic diversity in South America. Each group is defined by synapomorphies of its constituent genera: Lispocephala‐group by the presence of a posteroventral apical seta on the hind tibia, the presence of two arms in male sternite 6 (not forming a ring) and the short or very short female ovipositor; the Coenosia‐group by the presence of a developed epiproct and narrow sternites 6 and 7 of the female ovipositor. The following new generic synonymies are proposed (junior synonyms in parentheses): Lispocephala Pokorny (=Pectiniseta Stein), Coenosia Meigen (=Tenuicosta Stein; Dexiopsis Pokorny), Neodexiopsis Malloch (=Haroldopsis Albuquerque), Pilispina Albuquerque (=Levallonia Albuquerque; Noelia Albuquerque; Parvomusca Medeiros; Cholomyioides Albuquerque), Apsil Malloch (=Raymondomyia Malloch), Stomopogon Malloch (=Angolia Malloch; Angolina Pont) and Pygophora Schiner (=Chouicoenosia Cui & Xue).
Molecular phylogenetics of the Oriental members of  the Myzomyia Series of Anopheles subgenus Cellia (Diptera: Culicidae) inferred from nuclear and mitochondrial DNA sequences
Authors: Chen Bin , Butlin Roger K. , Harbach Ralph E.
Published: March 2003

Abstract. The phylogenetic relationships of fifteen Oriental and two Afrotropical taxa of the Myzomyia Series of Anopheles subgenus Cellia and two outgroup species, An. maculatus (Neocellia Series) and An. dirus A (Neomyzomyia Series), were inferred from nucleotide sequences of the entire 685 bp of the mitochondrial cytochrome oxidase subunit II locus (COII) and 372 bp of the third domain (D3) of the 28S rDNA locus, both separately and together. Alignment of the D3 sequences was achieved with the aid of secondary structure comparisons, and the pattern of nucleotide substitution was best explained by the GTR + I + G model for either separate or combined datasets. Maximum likelihood and maximum parsimony analyses robustly identified five monophylies: An. fluviatilis U and T; An. fluviatilis U and T + An. minimus A, C, E and #157 + An. leesoni; An. filipinae + An. mangyanus; An. filipinae + An. mangyanus + An. aconitus; and An. culicifacies A and B. The results confirm the specific status of An. flavirostris, the close relationship of An. leesoni with the Minimus Complex, and the exclusion of An. jeyporiensis, An. culicifacies s.l and An. funestus from the Minimus Group. All of the species classified as members of the Minimus Group on morphological grounds formed a single clade, which comprised two subgroups: the Minimus Subgroup, including An. minimus s.l., An. fluviatilis s.l., An. leesoni and An. flavirostris, and the Aconitus Subgroup, including An. filipinae, An. mangyanus, An. aconitus, An. pampanai and An. varuna. However, these clades are only weakly supported by the present dataset.
The volcanoseismic crisis of 1996–97 in Nisyros, SE Aegean Sea, Greece
Authors: Papadopoulos  , Sachpazi  , Panopoulou  , Stavrakakis
Published: March 2003

After a repose time of several years, intense, shallow seismic activity started at the end of 1995 in the volcanic region of Nisyros island. By the end of October 1997, hundreds of shocks had been recorded, the largest one being that of 27 August 1997 with
Ms = 5.3. The activity is highly clustered in space and time, while the
b‐value of the magnitude‐frequency relation was found equal to 1.67. Similar
b‐values were determined from Nisyros seismicity registered between 1911 and 1980 and from a 1997 microearthquake dataset. These properties seem to be a characteristic of the region, rather than precursor of a forthcoming eruption and make Nisyros similar to other large calderas of the Earth where the episodic unrest with local swarm‐like earthquake sequences separated by months or years is a typical pattern that do not culminate in a volcanic eruption.
The Dabie UHP unit, Central China: a Cretaceous extensional allochthon superposed on a Triassic orogen
Authors: Wang  , Neubauer  , Genser  , Yang
Published: March 2003

Petrological, geochronological and structural data show that the eastern Dabie metamorphic complex resulted from two orogenic stages. Precursor rocks of the ultrahigh‐pressure (UHP) and high‐pressure (HP) units in the present hanging wall tectonic position were buried, penetratively deformed and subsequently exhumed by distributed, ESE‐directed shearing during Triassic time. In contrast, rocks of the Dabie orthogneiss domes, now in a footwall tectonic position, were penetratively deformed during temperature‐dominated, Early Cretaceous tectonic events, that are likely related to magmatic underplating. The Dabie orthogneiss domes and the UHP/HP units were juxtaposed during Early Cretaceous exhumation of Dabie orthogneiss domes by the formation of an ESE‐directed low‐angle ductile normal shear zone. Consequently, the UHP/HP units now represent an extensional allochthon in the hanging wall of the younger normal shear zone. The Cretaceous extensional structures are limited by boundary strike‐slip faults. Consistent with the South China regional tectonic framework, ESE‐directed lateral extrusion is considered to be the driving mechanism for extension and the present‐day structure of the Dabie metamorphic complex.
Cosmic Ray Exposure (CRE) dating in a wet tropical domain: late Quaternary fan emplacements in central Sulawesi (Indonesia)
Authors: Bellier  , Bourles  , Beaudouin  , Braucher
Published: March 2003

Accurate chronological records are critical for studying the alluvial fan sequences emplaced during local/global climatic changes but, in general, there are no satisfactory, quantitative dating methods available. In situ‐produced 10Be concentrations have been measured in quartz boulders exposed on Sulawesian late Quaternary fan surfaces. These concentrations suggest that the two fan units evidenced by geomorphic study were emplaced during two distinct major climatic events. The calculated minimum exposure ages imply abandonment ages of 11 kyr and 120 kyr, for the younger and older units, respectively. This study demonstrates that using both the neutron and muon components implicated in the in situ10Be production, surficial erosion rates can be estimated and alluvial fans dated. In particular, it shows that in situ10Be may be used to date fan emplacement during the last 120 kyr under humid tropical conditions, significantly helping to constrain continental palaeoclimatology.
How did the foreland react? Yangtze foreland fold‐and‐thrust belt deformation related to exhumation of the Dabie Shan ultrahigh‐pressure continental crust (eastern China)
Authors: Schmid J.C.. , Ratschbacher L. , Hacker B.R.. , Gaitzsch I. , Dong S.
Published: March 2003

During the Triassic collision of the Yangtze and Sino‐Korean cratons, the leading edge of the Yangtze crust subducted to mantle depths and was subsequently exhumed as a penetratively deformed, coherent slab capped by a normal shear zone. This geometry requires a reverse shear zone at the base of the slab, and we suggest that the Yangtze foreland fold‐and‐thrust belt constitutes this zone. Lower Triassic rocks of the eastern foreland record NW–SE compression as the oldest compressional stress field; onset of related deformation is indicated by Middle Triassic clastic sedimentation. Subsequent Jurassic stress fields show a clockwise change of compression directions. Based on nearly coeval onset and termination of deformation, and on a common clockwise change in the principal strain/stress directions, we propose that the foreland deformation was controlled by the extrusion of the ultra high‐pressure slab. Widespread Cretaceous–Cenozoic reactivation occurred under regional extension to transtension, which characteristically shows a large‐scale clockwise change of the principal extension directions during the Lower Cretaceous.
Ir anomalies and other elemental markers near the Palaeocene–Eocene boundary in a flysch sequence from the Western Tethys (Slovenia)
Authors: Dolenec T. , Pavšič J. , Lojen S.
Published: March 2003

Ir abundance anomalies, platinum‐group elements (PGE) enrichment and increased concentrations of meteoritic (Ni, Fe, Co) and nonmeteoritic (Sb, As, Zn and Cu) elements were found in the Palaeocene–Eocene (P/E) boundary interval in a flysch sequence from the Western Tethys (Goriška Brda section, W. Slovenia). This records one of the most important calcareous deep benthic extinctions in the history of the Earth. Although the observed geochemical patterns could indicate complex sources for these metals, such as weathering of the continental and oceanic crust, volcanic processes, as well as diagenetic mobilization and redistribution, we cannot preclude the highly speculative possibility that the observed Ir abundances may also indicate extraterrestrial contamination.
SHRIMP U–Pb ages of diagenetic and hydrothermal xenotime from the Archaean Witwatersrand Supergroup of South Africa
Authors: England Gavin L. , Rasmussen Birger , McNaughton Neal J. , Fletcher Ian R. , Groves David I. , Krapez Bryan
Published: March 2003

SHRIMP dating of xenotime overgrowths on detrital zircon grains can constrain maximum durations since diagenesis and therefore provide minimum dates of sediment deposition. Thus, xenotime dating has significant economic application to Precambrian sediment‐hosted ore deposits, such as Witwatersrand Au–U, for which there are no precise depositional ages. The growth history of xenotime in the Witwatersrand Supergroup is texturally complex, with several phases evident. The oldest authigenic xenotime 207Pb/206Pb age obtained in sandstone underlying the Vaal Reef is 2764 ± 5 Myr (1 σ), and most likely represents a mixture of diagenetic and hydrothermal growth. Nevertheless, this represents the oldest authigenic mineral age yet recorded in the sequence and provides a minimum age of deposition. Other xenotime data record a spread of ages that correspond to numerous post‐diagenetic thermotectonic events (including a Ventersdorp event at ≈ 2720 Ma) up to the ≈2020 Ma Vredefort event.
First Permian–Early Triassic zircon ages for tin‐bearing granites from the Gemeric unit (Western Carpathians, Slovakia): connection to the post‐collisional extension of the Variscan orogen and S‐type granite magmatism
Authors: Poller Ulrike , Uher Pavel , Broska Igor , Plasienka Dusan , Janák Marian
Published: March 2003

This study presents the first preliminary U–Pb zircon data on tin‐bearing S‐type granites from the Gemeric unit of the Western Carpathians (Slovakia). U–Pb single zircon dating controlled by cathodoluminescence suggests crystallization of the Gemeric granites during Permian to Early Triassic (303–241 Ma) time. Post‐crystallization, low‐temperature metamorphic overprint is reflected by partial Pb loss in zircons. These Gemeric granites are younger than the highly fractionated, S‐type, tin‐ and rare‐element‐bearing leucogranites in the European Variscides. They may have resulted from partial melting, triggered by increased heat flow from the mantle below the continental crust, and most probably intruded during the post‐collisional extension and initial rifting of the Variscan orogenic belt. During Alpine orogeny, the Gemeric granites were affected by a low‐temperature deformation and metamorphism.
Organ‐dependent regulation of a plant promoter isolated from rice by 'promoter‐trapping' in tobacco.
Authors: Claes B , Smalle J , Dekeyser R , Van Montagu M , Caplan A
Published: March 2003

A vector containing a transcriptionally inactive neomycin phosphotransferase II gene was used to select promoter sequences from a pool of random genomic DNA fragments. This paper describes how one such sequence (P4.7) isolated from Oryza sativa acts as a hormonally regulated promoter in Nicotiana tabacum. Relative expression ratios in leaf, root, midrib, callus, and stem tissue of tobacco plants are 1:5:4:10:17. Histochemical assays show that P4.7 activates the uidA reporter gene throughout the phloem and cortex of tobacco stems. Transcription from the P4.7 fragment is inducible in leaf tissue by low levels of alpha‐naphthalene acetic acid or 6‐benzyl‐aminopurine, even when cell proliferation is inhibited by colchicine or hydroxyurea. Conversely, 1% DMSO was found to inhibit activation of P4.7 without interfering with callus formation. The fragment contains TATA and CAAT sequences normally found at the 5' end of many plant genes, and an additional region homologous to sequences located in similar positions in a variety of similarly regulated promoters. Promoter deletion and fusion experiments have indicated the location of a stem enhancer element in P4.7. The promoter trap system we have described may potentially be used to characterize transcriptional factors common to monocot and dicot species.
Genome reorganization in Nicotiana asymmetric somatic hybrids analysed by in situ hybridization
Authors: Parokonny A. S. , Kenton A. Y. , Gleba Y. Y. , Bennett M. D.
Published: March 2003

In situ hybridization was used to examine genome reorganization in asymmetric somatic hybrids between Nicotiana plumbaginifolia and Nicotiana sylvestris obtained by fusion of gamma‐irradiated protoplasts from one of the parents (donor) with non‐irradiated protoplasts from the other (recipient). Probing with biotinylated total genomic DNA from either the donor or the recipient species unequivocally identified genetic material from both parents in 31 regenerant plants, each originating from a different nuclear hybrid colony. This method, termed genomic in situ hybridization (GISH), allowed intergenomic translocations containing chromosome segments from both species to be recognized in four regenerants. A probe homologous to the consensus sequence of the Arabidopsis thaliana telomeric repeat (5′‐TTTAGGG‐3′)n, identified telomeres on all chromosomes, including ‘minichromosomes’ originating from the irradiated donor genome. Genomic in situ hybridization to plant chromosomes provides a rapid and reliable means of screening for recombinant genotypes in asymmetric somatic hybrids. Used in combination with other DNA probes, it also contributes to a greater understanding of the events responsible for genomic recovery and restabilization following genetic manipulation in vitro.
Transgenic potato plants resistant to the phytopathogenic bacterium Erwinia carotovora
Authors: Düring Klaus , Porsch Petra , Fladung Matthias , Lörz Horst
Published: March 2003

The phytopathogenic bacterium Erwina carotovora spp. which infects potato plants causes severe losses in agriculture. No protective means or resistance traits usable for plant breeding are known. Introduction of a new resistance gene into potato by gene technology leads to a reduced susceptibility of the transgenic plants towards Erwinia carotovora atroseptica infection. Bacteriophage T4 lysozyme is the most active member of a class of bacteriolytic enzymes also detected in several plant species. Secretion of the foreign T4 lysozyme into the intercellular spaces of transgenic potato plants effects a resistance against the phytopathogenic bacterium already at low expression levels.
A sink‐specific H+/monosaccharide co‐transporter from Nicotiana tabacum: cloning and heterologous expression in baker’s yeast
Authors: Sauer Norbert , Stadler Ruth
Published: March 2003

A cDNA clone for a monosaccharide transporter (MST1) was isolated from tobacco, which is most strongly expressed in the various sink tissues of mature tobacco plants: roots, flowers, and young leaves. An open reading frame of 1569 bp codes for a protein with 523 amino acids and a calculated molecular weight of 57 717 Da. The protein is homologous to a group of other plant monosaccharide transport proteins from Arabidopsis thaliana and Chlorella kessleri, to human glucose transporters and to Saccharomyces cerevisiae and several bacterial sugar transport proteins. As with these other transporters, the MST1 protein is extremely lipophilic and has 12‐putative membrane‐spanning domains. Heterologous expression of the MST1 cDNA clone in Saccharomyces cerevisiae allowed its characterization as a putative H+/monosaccharide co‐transporter, catalyzing the uptake of hexoses (e.g. d‐glucose and d‐galactose) or pentoses (e.g. d‐xylose) and the energy dependent and uncoupler sensitive accumulation of non‐metabolizable substrates (e.g. d‐xylose or 3‐O‐methyl‐glucose). Polyclonal antibodies were raised against a fusion protein of β‐galactosidase and the last 27 amino acids of the C‐terminus of the MST1 protein. In SDS extracts of transformed yeast cells these antibodies recognize a polypeptide with an apparent molecular weight of 42 kDa, which is absent in extracts from untransformed control cells.
Instability of the L6 gene for rust resistance in flax is correlated with the presence of a linked Ac element
Authors: Lawrence Greg , Finnegan Jean , Ellis Jeff
Published: March 2003

In a programme aimed at tagging rust‐resistance genes in flax with the maize transposable element Ac, a primary transformant of a line called ‘Forge’ that is homozygous for four rust‐resistance genes, L6, M, N and P2, was identified that possessed 10 copies of the Ac element, one of which was linked (29 map units) to L6. Descendants of this plant, which had from 8 to 15 copies of Ac, were crossed to a rust‐susceptible line and the progeny screened for rust‐susceptible mutants. When the Ac linked to L6 was present in the parent, a high frequency of L6 mutants was observed (29 mutants in 30 575). By contrast, when this Ac was absent, no such mutants were observed in 9258 progeny. The background frequency of L6 mutants was low (five in 124 088). A detailed analysis was made of the first 11 L6 mutants recovered from parents carrying the L6‐linked Ac element. While none of the mutants possessed a tagged resistance gene, all lacked an RFLP marker closely linked to L6, suggesting that deletions were responsible for loss of the L6 specificity. In many of the mutants, one or more RFLP markers in the vicinity of the linked Ac were also absent. These findings suggest that the linked Ac may be inducing chromosome breakage.
Transient gene expression in vegetative shoot apical meristems of wheat after ballistic microtargeting
Authors: Bilang Roland , Zhang Shibo , Leduc Nathalie , Iglesias Victor A. , Gisel Andreas , Simmonds John , Potrykus Ingo , Sautter Christof
Published: March 2003

A method has been established that allows the targeted delivery of DNA‐carrying gold particles to vegetative shoot apical meristems of cereal species. Meristems of 8‐ to 10‐day‐old seedlings of wheat (Triticum aestivum), rice (Oryza sativa) and sorghum (Sorghum bicolor) were manually exposed by removal of the coleoptile and the first three to four leaves. Using ballistic microtargeting, equal‐sized gold particles of different diameters ranging from 1.0 to 2.0 µm were propelled to meristems by pulses of compressed nitrogen ranging from 9 to 13 MPa. When accelerated by 13 MPa, particles of 1.4 µm or larger penetrated to cells of L2 in 80% of the bombarded wheat meristems. Expression vectors containing either the gene for β‐glucuronidase (gusA) or genes regulating the anthocyanin biosynthesis (Bperu and C1 from maize) were delivered to wheat meristems. The level of transient gene expression was dependent on the osmotic pressure of the MS‐based medium that was used to mount the explants for shooting: an increase of the sucrose concentration from 2 to 10% in the medium resulted in an increase of transient gene expression from 5 to 25% of the bombarded meristems. Although particles of 1.4 µm were efficiently delivered to L1 and L2, transient gene expression occurred predominantly in the L1 layer. In contrast, up to 10% of the bombarded meristems had expressing cells in L2 when particles of 2.0 µm were used. Ten days after bombardment, GUS‐positive sectors in meristems and in leaf primordia were observed. When destructive GUS detection was omitted, between 80 and 90% of the bombarded ex‐plants recovered in vitro on basal MS medium and then regenerated to fertile plants in the greenhouse.