bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of amending soil with Tagetes patula cv. Single Gold on Meloidogyne incognita infestation of tomato
Authors: Ploeg Antoon 
Published: July 2002

AbstractThe effects of amending soil with either roots or tops of tomato or marigold on subsequent tomato growth and infestation by Meloidogyne incognita was determined in greenhouse pot experiments. Controls consisted of non-amended soil, and pre-cropping for 8 weeks with tomato or marigold previously infested with M. incognita. Amending soil with marigold or tomato tops or roots increased the weight of tomato tops at high M. incognita inoculum densities. Galling and nematode populations were high when tomato followed tomato, but very low when tomato followed marigold. Galling and final nematode population levels were reduced by all soil amendments, but by much less than pre-cropping with marigold for 8 weeks. Although some reduction in nematode infestation can be achieved by amending soil with marigold plant parts, this reduction is not specific to marigold and is unlikely to be of practical use. Die Wirkung einer Bodenverbesserung mit Tagetes patula cv. Single Gold auf den Befall von Tomaten durch Meloidogyne incognita - In Topfversuchen im Gewächshaus wurde die Wirkung von Wurzeln oder oberirdischen Teilen von Tomate oder Tagetes auf das anschließende Wachstum und auf den Befall mit Meloidogyne incognita untersucht. Als Kontrollen dienten nichtverbesserter Boden oder eine acht Wochen lange Vorkultur von Tomaten oder Tagetes in voher mit M. incognita verseuchter Erde. Eine Bodenverbesserung mit oberirdischen Teilen oder Wurzeln von Tagetes oder Tomate steigerte das Gewicht der oberirdischen Teile von Tomatenpflanzen bei hohen Befallsdichten. Gallbildung und Nematodenpopulationen waren hoch, wenn Tomate auf Tomate folgte, aber nur gering bei Tomate nach Tagetes. Gallbildung und Höhe der Endpopulation wurden durch alle Bodenverbesserungen vermindert, aber deutlich weniger als durch eine achtwöchige Vorkultur von Tagetes. Obwohl eine gewisse Verminderung der Nematodenpopulation durch eine Bodenverbesserung mit Teilen von Tagetespflanzen erreicht werden kann, ist diese Verminderung nicht spezifisch für Tagetes und wahrscheinlich ohne praktischen Nutzen.
Variations in ribosomal DNA sequences and phylogeny of Globodera parasitising solanaceous plants
Authors: Subbotin Sergei , Perry Roland , Warry Andrew , Halford Paul 
Published: July 2002

AbstractThe D3 expansion region of the 28S gene and the ITS1-5.8S-ITS2 region of rDNA sequences from Globodera rostochiensis, G. pallida, G. tabacum tabacum, G. tabacum virginiae and G. tabacum solanacearum have been aligned and compared. There are no nucleotide differences in the D3 region sequences between G. rostochiensis and G. pallida. Sequence analysis and RFLPs of ITS-PCR products showed that several haplotypes are present in the genomes of G. rostochiensis and G. pallida populations. Restriction patterns of PCR products for eight enzymes for differentiation of these two species are given. Phylogenetic analysis of 41 ITS region sequences obtained from populations and species of the subfamily Punctoderinae revealed four distinct main clades within Globodera parasitising solanaceous plants: G. rostochiensis, G. tabacum, G. pallida and an undescribed Globodera sp. from South America. The utility of RFLP profiles and sequences of the rDNA are discussed for diagnostics and phylogeny of Globodera . Variabilité dans les séquences de l'ADN ribosomal et phylogénie des Globodera parasitant les Solanacées - La région d'expansion D3 du gène 28S et la région ITS1-5.8S-ITS2 des séquences d'ADNr de Globodera rostochiensis, G. pallida, G. tabacum tabacum, G. tabacum virginiae et G. tabacum solanacearum ont été alignées et comparées. Il n'y a pas de différence dans les nucléotides de la séquence de la région D3 entre G.rostochiensis et G.pallida. L'analyse séquentielle et les RFLP des produits du ITS-PCR montrent que plusieurs haplotypes sont présents dans les génomes des populations de G. rostochiensis et G. pallida. Les profils de restriction des produits du PCR de huit enzymes choisies pour la différenciation de ces deux espèces sont donnés. L'analyse phylogénique séquentielle de 41 regions ITS de populations et espèces appartenant à la sous-famille des Punctonerinae a révélé l'existence de quatre clades chez les Globodera parasitant les Solanacées: G. rostochiensis, G. tabacum, G. pallida et une espèce non décrite provenant d'Amérique du Sud. L'utilité pour le diagnostic et la phylogénie des Globodera des profils de RFLP et des séquences d'ADNr est discutée.
Some pratylenchids from Iran (Nematoda: Tylenchina)
Authors: Alizadeh Azizollah , Geraert Etienne , Pourjam Ebrahim 
Published: July 2002

AbstractIn a survey of the family Pratylenchidae from Iran three known species of the genera Hirschmanniella, Pratylenchoides and Zygotylenchus were found. Their similarities to and differences from closely related species, their distribution and their intraspecific variations are discussed. In some specimens of Zygotylenchus guevarai the spermatheca has numerous cells which may indicate a relationship of this genus with Meloidogyne. In Iranian populations of Pratylenchoides ritteri a vast range of morphological variations was observed. However, the head en-face view was the same for all populations. It seems that the pharyngeal terminal bulb contains more than three nuclei in most specimens. Hirschmanniella anchoryzae and P.ritteri which were studied by light microscopy (LM) and scanning electron microscopy (SEM) are reported for the first time from Iran. Quelques Pratylenchides d'Iran (Nematoda: Tylenchina) - Lors d'une enquête sur la famille des Pratylenchidae en Iran, trois espèces connues des genres Hirschmanniella, Pratylenchoides et Zygotylenchus ont été trouvées. Leur ressemblances, différences avec les espèces très proches, leur répartition et leur variations intra spécifiques sont discutées. Chez quelques spécimens de Zygotylenchus guevarai, la spermathèque possède des cellules nombreuses, ce qui pourrait indiquer un relation de ce taxon avec le genre Meloidogyne. Chez les populations iraniennes de Pratylenchoides ritteri, une large gamme de variation morphologique a été observée. Cependant, la morphologie de l'extrémité antérieure était identique pour toutes les populations. Il semble que le bulbe pharyngien terminal contienne plus de trois noyaux dans la plupart des spécimens. Hirschmanniella anchoryzae et P.ritteri qui ont été étudiés en microscopie optique (LM) et électronique à balayage (SEM) sont signalés pour la première fois en Iran.
Glasshouse studies on the effects of time, temperature and amendment of soil with broccoli plant residues on the infestation of melon plants by Meloidogyne incognita and M. javanica
Authors: Ploeg Antoon , Stapleton James 
Published: July 2002

AbstractThe effects of heating, over a range of temperatures and for increasing periods of time, and of adding finely chopped broccoli leaves to soil infested by Meloidogyne incognita and M. javanica on nematode infestation of melon, were studied in glasshouse experiments. There was a significant interaction between the effects of soil temperature, the period for which this temperature was maintained and broccoli amendment. At the lowest temperature tested (20°C), adding broccoli to the soil had very little effect on nematode infestation or galling of melon. Increasing the temperature of the broccoli-amended soils to 25, 30 or 35°C dramatically reduced infestation and galling compared to that in non-amended soils. Within this range, the effect of broccoli-amendment occurred sooner at higher temperatures. Heating the soil to 40°C for 10 days generally eliminated nematode infestation and root-galling, irrespective of whether broccoli had been added. Fewer egg masses were obtained from melon roots grown in broccoli-amended soils than from those grown in non-amended soils, even when roots exhibited similar degrees of galling. The results suggest that the temperature and time treatments using soil solarisation to control M. incognita or M. javanica could be reduced in soils amended with broccoli residues.
Upper Permian-Lower Cretaceous clay mineralogy of East Greenland: provenance, palaeoclimate and volcanicity
Authors: Lindgreen H. , Surlyk F. 
Published: July 2002

AbstractThe clay mineralogy of Upper Permian–Lower Cretaceous mudstones from East Greenland has been investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and thermal analysis in order to evaluate long-term trends in provenance and palaeoclimate and to detect possible volcanic events. The Upper Permian–Lower Triassic mudstones contain illite, chlorite, vermiculite, kaolinite and illite-smectite (I-S), whereas the Rhaetian–Sinemurian mudstones are dominated by kaolinite. Aalenian–Albian mudstones contain kaolinite and large amounts of I-S with ˜80% illite layers. Exceptions are three Kimmeridgian samples, which contain mainly I-S with 30% illite layers, and three Upper Barremian–Lower Aptian samples with large amounts of smectite layers. Discrete clay minerals in the Upper Permian–Jurassic mudstones are largely detrital. The smectite-rich I-S probably reflects episodes of volcanic activity in late Jurassic and late Barremian–early Aptian times. This is the first indication of Mesozoic volcanism from the Mesozoic rift basin of East Greenland. The main sediment source during late Permian–early Cretaceous times was weathered Precambrian and Caledonian crystalline basement. The only possibly climate-induced change is a change from chlorite, illite, vermiculite and kaolinite in Upper Permian–Lower Triassic mudstones to kaolinite and I-S in the Jurassic mudstones and is probably due to an increase in precipitation.
Geochemical correlation of bentonites from Milos Island, Aegean, Greece
Authors: Christidis G. E. 
Published: July 2002

AbstractMajor and trace chemical elements from eleven Lower Pleistocene bentonite deposits from Eastern Milos Island, Aegean, Greece, were used for geochemical fingerprinting of the bentonites, by means of scatter binary and ternary plots and canonical discriminant analysis. The trace elements were selected according to their immobility during bentonite formation and subsequent hydrothermal alteration. The bentonites can be separated into at least four geographically distinct groups, each consisting of materials with similar geochemical affinities. The deposits of each group were derived from protoliths erupted from different volcanic centres, suggesting the existence of at least two distinct volcanic provinces, having rhyolitic and andesitic affinities respectively. Several deposits consist of more than one bentonite horizon, indicating that in some volcanic centres the character of volcanism changed with time. Geochemical fingerprinting, supplemented with geological, mineralogical, and textural evidence, may be useful for correlation and exploration of bentonites, in terrains with complex geological histories.
HRTEM study of freeze-dried and untreated synthetic ferrihydrites: consequences of sample processing
Authors: Greffié C. , Amouric M. , Parron C. 
Published: July 2002

AbstractTwo-line ferrihydrite samples were synthesized following conventional procedure. Detailed characterizations of freeze-dried and untreated samples – prepared from direct inclusion of the fresh precipitates in hydrophilic resin – were made by high resolution transmission electron microscopy to investigate in detail their structural organization and to compare the two types of preparations.Only highly disordered chain-like aggregates of 2 5 nm diameter size nano-particles were revealed within the untreated samples. Conversely, in freeze-dried samples, domains with different degrees of order were recognized, from poorly ordered 2-line ferrihydrite to 3-line ferrihydrite particle aggregates that revealed lattice fringes. Associated with these aggregates, a goethite phase with a modified crystal morphology was also observed.These HRTEM observations revealed that freeze-drying techniques induce artifacts by disturbing ferrihydrite aggregates while direct inclusion in hydrophilic resin preserves the primary organization of such poorly ordered phases.
Clay mineralogical investigations related to nuclear waste disposal
Authors: Madsen F. T. 
Published: July 2002

AbstractMineralogical and geotechnical investigations on the possible use of compacted bentonite as a buffer material in nuclear waste repositories are reported. The swelling capacity is highly dependent on the density of the compacted bentonite. Swelling pressures >30 MPa were measured for dry densities of ~2.0 g/cm3. Added iron or magnetite powder up to 20 wt% had no influence on the swelling capacity. Compacted mixtures of 20 wt% ground set cement and bentonite showed higher swelling pressures but lower swelling strain capability than compacted bentonite alone. Steam lowered the swelling pressure of compacted bentonite to ~60% of the original value. The influence was, however, reversible by ultrasonic treatment. The thermal conductivity of saturated compacted bentonite at a density of 2.0-2.1 g/cm3is ~1.35-1.45 W/m°K The volumetric heat capacity ranges from 3.1 x 106to 3.4 x 106j/m3°C The saturated hydraulic conductivity of the compacted bentonite is <10-12m/s. The apparent diffusion coefficients for various ions in compacted bentonite for water contents in the range of 20 to 25 wt% are: K+: 5 x 10-11, Cs+: 6 x 10-12, Sr2+: 3 x 10-11, UO22+: <10-13, Th4+: <10-13, Fe2+: 4 x 10-11, Fe3+: 4 x 10-11, Cl-: 1 x 10-10and I-: 1 x 10-10m2/s. The 'breakthrough time' for an apparent diffusion coefficient of 10-11m2/s in compacted bentonite 1 m thick was estimated to be ~3000 years. The mineralogical longevity was investigated on natural K-bentonites from Kinnekulle, Sweden, and Montana, USA. Although these materials have undergone considerable changes during diagenesis and contain various amounts of mixed-layer illite-smectite, they still have a substantial swelling and adsorption capacity. The investigations demonstrate that although the properties of bentonite are negatively influenced to a certain extent by heat, hot steam, iron and cement, compacted bentonite is still the best choice to act as a buffer material in a nuclear waste repository.
New data on the kaolinite-potassium acetate complex
Authors: Ruiz Cruz M. D. , Franco Duro F. I. 
Published: July 2002

AbstractThe intercalation complex of kaolinite and potassium acetate (KAc) was studied by HTXRD, IR spectroscopy and DTA-TG. The HTXRD patterns indicate that the 14.06 Å basal spacing of the complex contracts to 11.77 Å and 9.35 Å after heating at 60°C. The DTA-TG data indicate that water is present in these new complexes, the decomposition of which occurs between 290°C and 400°C. Modifications observed in the high-frequency region of the spectra obtained after heating suggest that K ions occupy the ditrigonal holes in the OH surface of the kaolinite layers, whereas water is probably located between the KAc layer and the OH surface of the kaolinite. This structural arrangement would favour the H-bonding between inner-surface OH groups and water and justifies the presence of new bands at lower frequencies. Electrostatic interactions between the keyed K ions and O of the inner OH groups would justify the modifications of the 3619 cm-1 OH-stretching band.
Synthesis of troilite by the arc-discharge method
Authors: Daizhang Chen , Xiang Yang 
Published: July 2002

AbstractTroilite is a sulfide that occurs commonly in meteorites. In the laboratory, it can be synthesized by gas-solid reaction of metallic Fe and H2S-H2 gas mixtures. In this research, the arc-discharge method was used to synthesize troilite. The resulting spherules are up to 2–3 mm in diameter and composed of troilite, pyrrhotite and metallic Fe. Nanometer-sized hollow carbon fibres and balls occur on the surface of the spherules. The features and coexisting relationships of the constituents of the spherules were studied by X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the phenomenon of transformation of pyrite (FeS2) into pyrrhotite (Fe1-xS), troilite (FeS) and metallic Fe under arc-discharge reducing conditions were examined.
Arizona porphyry copper/hydrothermal deposits I. The structure of chenevixite and luetheite
Authors: Burns P. C. , Smith J. V. , Steele I. M. 
Published: July 2002

AbstractThe crystal structure of chenevixite, Cu2M2(AsO4)2(OH)4 (where M = Fe3+ or Al), pseudo-orthorhombic, monoclinic, a = 5.7012(8), b = 5.1801(7), c = 29.265(2) Å, β = 89.99(1)°, V = 864.3(4) Å3, space group B1211, Z = 4, was solved by direct methods and refined by least-squares techniques to R = 8.4% and a goodness-of-fit (S) of 1.37 for 1176 unique observed (F≥4σF) reflections collected for a twinned microcrystal using graphite-monochromated Mo-Kα X-rays and a CCD area detector. Vertex- and edge-sharing arsenate tetrahedra, Alϕ6 octahedra, and Jahn-Teller-distorted Cu2+ϕ6 octahedra [ϕ: O2−;, (OH)−;] form a framework unique from those in Cu2+ oxysalt minerals. Chains of edge-sharing Cu2+ϕ6 octahedra, with Alϕ6 octahedra attached on opposing sides by the sharing of edges, are linked into layers parallel to (001) by sharing vertices with AsO4 tetrahedra, and the layers are linked to form a frameworkby the sharing of polyhedral elements between adjacent Alϕ6 octahedra, as well as between AsO4 tetrahedra and Alϕ6 octahedra.
The mafic mineralogy of the Pandé massif, Tikar plain, Cameroon: implications for a peralkaline affinity and emplacement from highly evolved alkaline magma
Authors: Njonfang E. , Moreau C. 
Published: July 2002

AbstractThe Pandé massif is a small (4.9×63.4 km) subvolcanic complex of the Cameroon Line striking W – E and intrudes a Panafrican granite basement. It comprises a syenite-granite suite, where coarse- to finegrained syenites are predominant and the granites are the product of residual melt after syenite crystallization, and two volcanic (trachyte-rhyolite and trachyte) sequences. Amphibole and pyroxene are the dominant mafic silicates, the first occurring mainly in rhyolites and coarse- to medium-grained syenites, and the second, principally in all syenites, trachytes and granites. Rare biotite flakes are encountered in the coarse-grained or alkaline syenites and fayalite rimmed with oxides occurs in trachyte from the first volcanic sequence (T1). Apatite and zircon are common accessories, whereas some titanite occurs in the medium-grained syenites. The plutonic rocks are drusy, intrude the first volcanic sequence but pre-date the second (T2).All the mafic minerals are Fe-rich. Detailed studies of amphibole and pyroxene show that their compositions define relatively limited trends, amphibole varying from ferro-richterite to arfvedsonite and pyroxenes along the acmite-hedenbergite join of the Ac-Hd-Di diagram, in both the intrusive suite and volcanic rocks. Where the two minerals coexist, pyroxene crystallized subsequent to amphibole, a situation generally found in late-stage or subsolidus aegirines. The overlap in plutonic and volcanic pyroxene trends suggests their crystallization from magmas of the same composition. However, the presence of quartz and fayalite in T1 and of pure aegirine in T2 and the occurrence of Zr-bearing aegirine (NaZr0.5Fe0.52+Si2O6) in the early crystallizing alkaline syenites evolving towards pure aegirine from medium- to fine-grained quartz syenites and granites, are consistent with changes in oxygen fugacities during magmatic differentiation. Two stages are distinguished: fO2 increasingly decreased from T1 to alkaline syenite emplacement (from 10−16 to 10−24 bracketed by WM and QFM buffers) where a disequilibrium, probably caused by water dissociation with volatile loss (H2) during magma degassing, favoured crystallization of Zr-bearing aegirine; a decrease in amphibole proportions towards medium-grained quartz syenites and an increase in fO2 from the medium-grained quartz syenites to granites and T2 sequence.The Mg-poor nature of all the mafic silicates, subsolidus origin of amphiboles, crystallization of pyroxene subsequent to amphibole and subsolidus trends defined by pyroxenes are compatible with the parental magma having itself been a late-stage derivative magma, e.g. the last product of an alkaline melt from which the voluminous Mayo Darlé granite bodies crystallized.
Thermally induced transformations of Fe oxide-stabilized residues from waste incineration
Authors: Sørensen M. A. , Bender Koch C. 
Published: July 2002

AbstractAir pollution control (APC) facilities at waste incinerator plants produce large quantities of solid residues rich in salts and heavy metals. Heavy metals are readily released to water from the residues and it has, therefore, been found suitable to apply a rapid co-precipitation/adsorption process as a means to immobilize the toxic elements. In the ‘Ferrox process’, this immobilization is based on co-precipitation with an Fe(III) oxide formed by oxidation of Fe(II) by air in an aqueous slurry with the APC residue at alkaline pH. In this work we have undertaken a Mössbauer spectroscopy study of the Fe oxide phase formed by precipitation at room temperature and of the oxides present after heating to 600 and 900°C. The only Fe oxide observed in the Ferrox product at room temperature is a very poorly crystalline ferrihydrite. Analytical transmission electron microscopy showed that the main elements associated with the ferrihydrite are Si and Ca. Following heating to 600°C the oxide is still characterized as an amorphous Fe oxide, and it is probable that Si associated with the ferrihydrite is decisive in preventing crystallization. After the 900°C treatment a transformation into defect maghemite is observed. Reducing gases produced from carbon in the samples probably induces this transformation. It eases, thus, the reduction of Fe(III) and the consequent formation of magnetite that eventually oxidizes to maghemite during cooling in air.
Structure and chemistry of phosphate minerals
Authors: Hawthorne Frank C. 
Published: July 2002

AbstractFor complex rocks in which the structure of minerals, rather than their chemical composition, changes with progressive evolution of the system, it makes sense to try and monitor such an evolving system through the progressive change in the crystal structures of the constituent phases. In effect, the paragenetic sequences of minerals in such complex environments should be related to the crystal structures of the constituent minerals. In order to consider variations in structure topology, we need to organize crystal structures into hierarchical schemes, using the hypothesis that structures may be hierarchically ordered according to the polymerization of the coordination polyhedra with higher bondstrengths. Structural units are organized according to the mode of polymerization: unconnected polyhedra, clusters, chains, sheets and frameworks.The bond-valence structure of (OH) and (H2O) shows that on one side, (OH) and H2O are strong Lewis bases; on the other side, they are weak Lewis acids. As a result, a very important role of both (OH) and (H2O) is to prevent polymerization of the structural unit in specific directions. Thus, the dimensionality of the structural unit is controlled primarily by the amount and role of hydrogen in the structure. The way in which we have formulated these ideas also allows development of a predictive framework within which specific aspects of the chemistry and structure of phosphates can be considered.This approach to mineral structure, applied via the idea of a structural unit, can play a major role in developing structural hierarchies in order to bring about some sort of order to the plethora of hydroxyhydrated-phosphate structures. Furthermore, by combining the idea of binary structural representation with bond-valence theory, we see the eventual possibility of predicting stoichiometry and structural characteristics of these minerals, particularly those in complex low-temperature hydrothermal environments