bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fine gold particles and gold dust in alluvial autochthonous placers in southern West Siberia
Authors: Nesterenko G.V. , Kolpakov V.V. 
Published: November 2007

Abstract
This paper deals with the behavior of fine gold particles (0.25–0.1 mm) and gold dust (&lt;0.1 mm) during the formation of alluvial placers in denudation areas in southern West Siberia. Native gold particles with a low settling velocity, &lt;5–10 cm/s, such as dust (&lt;0.1 mm) and fine flat particles, are transported with a river stream beyond denudation areas. This easily migrating gold participates in the formation of lithochemical flows, which are an important indicator of gold mineralization. It occurs in the upper beds of alluvial section. Heavier fine gold particles are partly retained at the site of river activity, and the rest are partly redeposited in cooler parts of placers, being graded according to their settling velocity, as evidenced from the direct relationship between the flatness and size of gold particles. Fine gold particles do not form large accumulations in alluvial autochthonous placers. The main typomorphic features of fine gold particles and gold dust are their abundance in ore sources, compositional similarity to larger gold fractions, and high migration ability. In contrast to morphological features of gold, these ones remain stable during the river drift.
Resistivity logging in a multi-scale medium with lognormal conductivity
Authors: Kurochkina E.P. , Soboleva O.N. , Epov M.I. 
Published: November 2007

Abstract
We derived equations of effective conductivity coefficients to estimate mean current density and its variance in resistivity logging problems for isotropic multi-scale porous media with lognormal conductivity distribution. The equations have quite a simple form if the medium parameters satisfy refined Kolmogorov’s similarity hypothesis. The results of the refined perturbation theory obtained using subgrid modeling are compared with the results of numerical simulation and the conventional perturbation theory.
Paleomagnetism of Upper Jurassic basalts from Transbaikalia: new data on the time of closure of the Mongol-Okhotsk Ocean and Mesozoic intraplate tectonics of Central Asia
Authors: Metelkin D.V. , Gordienko I.V. , Klimuk V.S. 
Published: November 2007

Abstract
The Upper Jurassic basalts (150–160 Ma) described as the Ichetui Formation over the territory of the Tugnui, Margintui, and Maly Khamar-Daban volcanic structures have been studied paleomagnetically. It is shown that natural remanent magnetization still contains a component which may reflect the geomagnetic field direction at the beginning of the Late Jurassic. This is supported by reversal and conglomerate tests. Calculation of mean paleopole gives: Plat = 63.6°, Plong = 166.8°, α95 = 8.5°. These values well coincide with the data for the Badin Formation from Mogzon depression, which lies east of the study area and approximately dates from the Kimmeridgian-Oxfordian interval of the Late Jurassic. At the same time, those poles statistically differ from the European and Southeast Asian poles of the same age. The available paleomagnetic data suggest that at the beginning of the Late Jurassic the Mongol-Okhotsk Ocean was probably still open. Since the early Late Jurassic the continental blocks of Southeastern Asia and Siberian part of the Eurasian plate had been approaching, with the Siberian domain rotating clockwise. Analysis of the total of data shows that sinistral strike-slip deformations were present not only in southern Siberia but also between the Siberian and European Platforms. Thus, the deformations of the Central Asian crust in the early Late Jurassic reflect the intraplate strike-slip motions coeval with the closure of the Mongol-Okhotsk Ocean and are governed by the clockwise rotation of the Siberian part of the Eurasian plate relative to its European part.
Petrogenetic analysis of fluid and melt inclusions in minerals from mantle xenoliths from the Bele pipe basanites (North Minusa depression)
Authors: Golovin A.V. , Sharygin V.V. 
Published: November 2007

Abstract
Results of study of different types of inclusions in minerals from mantle xenoliths from the Bele pipe basanites are presented. Two groups of inclusions were recognized in the host minerals according to their genesis. The first group includes single, apparently primary, fluid inclusions. They were discovered only in orthopyroxenes and consist of CO2 (95 mol.%) and N2 (5 mol.%). These inclusions had partly leaked. The densities of two least leaked inclusions from different xenoliths are 1.05 and 1.14 g/cm3, and their trapping pressures are estimated at &gt;8.5 and 12 kbar, respectively. The second group includes syngenetic secondary fluid, melt, and crystalline inclusions. In composition the secondary fluid inclusions differ from the primary ones in higher concentrations of N2 (up to 7 mol.%). Their maximum density is 0.57 g/cm3, which corresponds to 2.4–2.6 kbar and 1100–1200 °C (homogenization temperature of secondary melt inclusions). Comparison of data on melt inclusions in xenolith minerals and host-basanite phenocrysts shows that the secondary inclusions in the xenoliths are, most likely, the result of infiltration and partial reaction of basanitic melt with the xenoliths. On the ascent, the basanitic melt vigorously reacted with mantle xenoliths, which led to the appearance of secondary inclusions in nodule minerals at shallow depths and interstitial mineral assemblages in the xenoliths.
Nanosecond electromagnetic sounding of a fluid-saturated layered formation
Authors: Epov M.I. , Mironov V.L. , Komarov S.A. , Muzalevsky K.V. 
Published: November 2007

Abstract
Mathematical modeling was applied to study attenuation of a nanosecond pulse that propagated in an oil-bearing formation and was reflected from the oil-gas or oil-water interfaces. The problem was formulated and solved for propagation of a short electromagnetic Gaussian pulse in a layered hydrocarbon reservoir in the case of excitation by a long electric line. Complex permittivity of oil-bearing rocks was calculated using a refractive mixing dielectric model for oil, saline water, methane, quartz, and bentonite in each layer. We obtained and analyzed space-time diagrams of wave propagation and reflection and estimated effective attenuation for both cases.
The Late Jurassic age and geochemistry of ultramafic-mafic massifs of the Selenga-Stanovoy superterrane (southern framing of the North Asian craton)
Authors: Buchko I.V. , Sorokin A.A. , Sal’nikova E.B. , Kotov A.B. , Larin A.M. , Izokh A.E. , Velikoslavinsky S.D. , Yakovleva S.Z. 
Published: November 2007

Abstract
We present new data on the age and geochemistry of the Veselyi and Petropavlovsk ultramafic-mafic massifs of the Selenga-Stanovoy (West Stanovoy) superterrane on the southeastern framing of the North Asian craton. The massifs are composed of rocks of peridotite-websterite-gabbro and peridotite-gabbro-monzodiorite associations, respectively. The latter combine normal, subalkalic, and alkaline rocks and thus are of diverse composition: from ultrabasites and pyroxenites through gabbroids to monzodiorites. The U-Pb zircon age of these massifs is 154 ± 1 and 159 ± 1 Ma, respectively, which permits them to be referred to as the youngest rocks of ultramafic-mafic complexes on the southern framing of the North Asian craton. The rocks of the studied massifs are enriched in LILE (K, Rb, Sr, Ba, LREE) and are depleted in HFSE (Zr, Nb, Hf, Ta). These rocks formed, most likely, in the rear of subduction zone or in the setting of the subducting-slab detachment.
Antimony in hydrothermal processes: solubility, conditions of transfer, and metal-bearing capacity of solutions
Authors: Obolensky A.A. , Gushchina L.V. , Borisenko A.S. , Borovikov A.A. , Pavlova G.G. 
Published: November 2007

Abstract
Based on data on the composition of ore-bearing hydrothermal solutions and parameters of ore-forming processes at various antimony and antimony-bearing deposits, which were obtained in studies of fluid inclusions in ore minerals, we investigated the behavior of Sb(III) in the system Sb–Cl–H2S–H2O describing the formation of these deposits.
We also performed thermodynamic modeling of native-antimony and stibnite dissolution in sulfide (mHS− = 0.0001−0.1) and chloride (mCl− = 0.1−5) solutions and the joint dissolution of Sb(s)0 and Sb2S3(s) in sulfide-chloride solution (mHS− = 0.01; mCl− = 1) depending on Eh, pH, and temperature. All thermodynamic calculations were carried out using the Chiller computer program. Under the above conditions, stibnite precipitates in acid, weakly acid to neutral, and medium redox solutions, whereas native antimony precipitates before stibnite under more reducing conditions in neutral to alkaline solutions.
The metal-bearing capacity of hydrothermal solutions (200–250 °C) of different compositions and origins has been predicted. We have established that the highest capacity is specific for acid (pH = 2–3) high-chloride solutions poor in sulfide sulfur and alkaline (pH = 7–8) low-chloride low-sulfide solutions.
Experimental and molecular genetic analysis of the impact of pyrethroid and non-pyrethroid insecticide impregnated bednets for mosquito control in an area of pyrethroid resistance
Authors: Kolaczinski J.H. , Fanello C. , Hervé J.-P. , Conway D.J. , Carnevale P. , Curtis C.F. 
Published: November 2007

AbstractExperimental huts in Côte d’Ivoire were used to evaluate the pyrethroid alpha-cypermethrin, the non-ester pyrethroid etofenprox, the organophosphate pirimiphos-methyl and the carbamate carbosulfan on bednets against pyrethroid-resistant Anopheles gambiae Giles. To test for selection for the resistance gene by the treated nets, A. gambiae collected live or dead from the huts were kept and analysed for the presence of the kdr gene using a new polymerase chain reaction followed by sequence-specific oligonucleotide probing (PCR–SSOP) for kdr-genotyping. Deliberately holed bednets freshly treated with pirimiphos-methyl or carbosulfan caused over 90% kill of A. gambiae s.s. and Culex spp. However, the mortality with alpha-cypermethrin or etofenprox treated nets was similar to that with untreated nets. Bloodfeeding of A. gambiae s.s. on the sleepers under the nets was only significantly reduced by alpha-cypermethrin and carbosulfan. Tests of the residual activity of the bednets after seven months showed that pirimiphos-methyl had lost its efficacy while carbosulfan still performed well. Once again the pyrethroid treated nets gave similar results to the untreated nets. Selection for the kdr-allele by alpha-cypermethrin and etofenprox, but not by carbosulfan, was indicated by PCR–SSOP genotyping of mosquitoes. Thus carbamates such as carbosulfan, or organophosphates of longer persistence than pirimiphos-methyl and of low mammalian toxicity, would seem to be a promising alternative to be used on bednets, particularly in areas of pyrethroid resistance.
Genetic relationships among biotypes of Bemisia tabaci (Hemiptera: Aleyrodidae) based on AFLP analysis
Authors: Cervera M.T. , Cabezas J.A. , Simón B. , Martínez-Zapater J.M. , Beitia F. , Cenis J.L. 
Published: November 2007

AbstractGenetic similarities between 13 samples belonging to nine reference biotypes and two field populations of Bemisia tabaci (Gennadius), one field population of B. medinae Gómez-Menor and another of B. afer Priesner &Hosny, were evaluated using amplified fragment length polymorphism (AFLP) markers. The results indicate that B. tabaci biotypes can be grouped together with a minimum similarity coefficient of 0.32 and separated from the two other species with a similarity coefficient of 0.07. Bemisia tabaci biotypes were grouped in four clusters which comprised: (i) Near East and Indian subcontinent biotypes; (ii) B and Q biotypes plus a Nigerian population from cowpea; (iii) New World A biotype; and (iv) S biotype and a Nigerian population from cassava. These results were consistent with a previous grouping of biotypes based on RAPD-PCR analysis. The AFLP assay allowed the scoring of a total of 354 polymorphic bands in two reaction events with the use of two primer combinations.
The whiteflies (Hemiptera: Aleyrodidae) of Europe and the Mediterranean Basin
Authors: Martin J.H. , Mifsud D. , Rapisarda C. 
Published: November 2007

AbstractThe whitefly fauna of Europe and the Mediterranean Basin comprises 56 species that are considered to be native or naturalized, accommodated within 25 genera. Presented here are a check-list, an identification key to puparia, and a brief account of each species including its distribution and host-plant range. The puparium of each species is illustrated. One new nomenclatural combination (Aleuroclava similis, fromAleurotuberculatus) and two new synonymies (Parudamoselis kesselyakiwithCeraleurodicus varus,Asterobemisia nigriniwithA. paveli) are proposed. Three nominal species (Aleurodes capreae, A. fraxini, andAleyrodes campanulae) are here treated asnomina dubia. Species which, in the study area, have only been recorded from glasshouses are discussed. Four additional species, not yet recorded from the region, are included in the discussion, two of them because a particular quarantine risk is perceived and two because they are notifiable pests in European Union quarantine legislation.
Suitability of two root-mining weevils for the biological control of scentless chamomile, Tripleurospermum perforatum, with special regard to potential non-target effects
Authors: Hinz H.L. , Müller-Schärer H. 
Published: November 2007

AbstractThe biology and host range of the two root-mining weevils Diplapion confluensKirby and Coryssomerus capucinus (Beck), two potential agents for the biological control of scentless chamomile Tripleurospermum perforatum (Mérat) Laínz, were studied in the field in southern Germany and eastern Austria, and in a common garden and under laboratory conditions in Delémont, Switzerland from 1993 to 1999. Both weevils were univoltine, and females started to lay eggs in early spring. Diplapion confluens had three and C. capucinus five instars. Larvae of both species were found in the field from mid-April until the end of July; later instars preferentially fed in the vascular cylinder of the shoot base, root crown or root. Although larvae of both species occupy the same temporal and spatial niche within their host plants, they occurred at all investigated field sites together, and showed a similar distribution within sites. No negative or positive interspecific association was detected. Host-specificity tests including no-choice, single-choice, and multiple-choice tests under confined conditions, as well as tests under field conditions with natural and augmented insect densities revealed that both herbivores were specific to plant species in the tribe Anthemideae. However, their development to mature larva or adult on several cultivated plants, as well as on one plant species native to North America, rendered them unsuitable for field release in North America. It was concluded that to investigate non-target effects reliably, host-specificity tests with biological control agents should be carried out under a variety of conditions, particularly with augmented insect densities, as are expected to occur naturally after release.
The frequency of host biting and its effect on oviposition and survival in Aedes aegypti (Diptera: Culicidae)
Authors: Canyon D.V. , Hii J.L.K. , Muller R. 
Published: November 2007

AbstractThe effect of host availability at 6 h, 12 h and 24 h intervals on temporal variation in median host-biting frequency, oviposition and survival of the mosquito, Aedes aegypti (Linnaeus), was investigated under laboratory conditions. In each feeding interval, ten replicates containing five mosquitoes were assessed over 12 days. Median host-biting frequencies were 0.7 bites per female mosquito in the 24 h feeding interval, 0.54 bites per female in the 12 h feeding interval, and 0.47 bites per female in the 6 h feeding interval. Although the 24 h figure was comparable to previously documented levels, feeding increased by 1.5 and 2.7 fold in the 12 and 6 h feeding intervals over a 24 h period. Host biting and oviposition were observed to peak at dusk in the 6, 12 and 24 h feeding intervals, but substantial activity was also observed at dawn, noon and midnight. Daily feeding analysis showed that host biting decreased by approximately 50% in all feeding interval trials over the 12 day test period. Oviposition peaks coincided with biting decline, suggesting a three day gonotrophic cycle. Survival did not differ significantly between feeding intervals. The reported rate of 0.47 host bites per female mosquito per 6 h (≈ 1.9 per 24 h) is thus far the highest recorded for A. aegypti. The suggestion that A. aegyptiprobably feeds more regularly than once in a 24 h period in nature is consistent with the biting and oviposition results.
Comparative evaluation of Cotesia flavipes and C. sesamiae (Hymenoptera: Braconidae) for the management of Chilo partellus (Lepidoptera: Pyralidae) in Kenya
Authors: Sallam M.N. , Overholt W.A. , Kairu E. 
Published: November 2007

AbstractCotesia flavipes Cameron, a gregarious larval endoparasitoid native to the Indo-Australian region, was imported from Pakistan and released in Kenya in 1993 for management of the exotic stemborer, Chilo partellus (Swinhoe). Recent reports confirmed the successful establishment of the parasitoid in three locations in Kenya and in northern Tanzania. Functional response studies on this parasitoid and an indigenous congener, Cotesia sesamiae (Cameron), indicated that C. flavipes had a higher searching ability and attacked more larvae when Chilo partellus was the host. When a native stemborer, Sesamia calamistis Hampson, was the host, there was no significant difference between numbers attacked by both parasitoids. Numerical response studies showed that Cotesia flavipes produced more total progeny and female progeny per female parasitoid on Chilo partellus than did Cotesia sesamiae. No significant difference in progeny production was detected between the two parasitoids on S. calamistis. Functional and numerical responses tested in the laboratory gave the same ranking of the two parasitoids on the two hosts as in the field. This study suggests that Cotesia flavipes is a more efficient parasitoid and it is anticipated that it will contribute to the control of both exotic and native stemborers in Kenya.
Evaluation of the effect of mosquito age and prior exposure to insecticide on pyrethroid tolerance in Anopheles mosquitoes (Diptera: Culicidae)
Authors: Hodjati M.H. , Curtis C.F. 
Published: November 2007

AbstractThe times for knockdown of resistant and susceptible strains of both Anopheles stephensi Liston (DUB234 and BEECH) and A. gambiae Giles (RSP and KWA), on exposure to a permethrin impregnated net were determined to evaluate the effect of age on susceptibility to permethrin. The mean knockdown times of pyrethroid resistant strains of A. stephensi and A. gambiae were significantly shorter if they were 10 days old (either fed or unfed), as compared with those of newly emerged mosquitoes. Based on KT50 values, the resistance ratios between resistant and susceptible A. stephensi were 3.5 and 2.2 for the newly emerged and 10-day-old mosquitoes, respectively. After 1 h exposure to paper impregnated with 0.25%permethrin, mortality of newly emerged individuals of the susceptible and resistant strains of A. stephensi was significantly less than when they were 10 days old. Irritability by permethrin was less with the resistant strain of A. stephensi. In the other strains irritability declined significantly with age. Pre-exposure of susceptible mosquitoes of BEECH and IRAQ strains of A. stephensi for a short time to permethrin did not increase tolerance when the mosquitoes were re-exposed 24 h later. Because of the age effect and the possibility of an effect of pre-exposure under some circumstances, confirmatory tests on newly emerged F1 individuals reared from wild collected mosquitoes are recommended in monitoring for resistance in wild populations.
Introduction of parasitoids for the control of the cassava mealybugPhenacoccus herreni(Hemiptera: Pseudococcidae) in north-eastern Brazil
Authors: Bento J.M.S. , de Moraes G.J. , Bellotti A.C , Castillo J.A. , Warumby J.F. , Lapointe S.L. 
Published: November 2007

AbstractThe mealybugPhenacoccus herreniCox & Williams causes considerable damage to cassavaManihot esculentaCrantz. Field surveys conducted between 1988 and 1994 indicated the mealybug was present in 57 municipalities in six States in north-eastern Brazil, in some places reaching high levels of infestation. Several native natural enemy species were found associated with the pest in Brazil. Exotic encyrtid parasitoids were imported and released in fields in the States of Bahia and Pernambuco.Apoanagyrus diversicornis(Howard) was introduced from Colombia, andAcerophagus coccoisSmith, andAenasius vexans(Kerrich) were introduced from Venezuela. By the end of 1996, a total of 35,930 parasitoids had been released. In Bahia,Apoanagyrus diversicorniswas recovered 130, 234, 304 and 550 km from its release site after 6, 14, 21 and 33 months, respectively.Acerophagus coccoiswas recovered at 180 km from its release site nine months after release.Aenasius vexans, however, did not disperse at all despite being consistently recovered at its release site. In Pernambuco, 9010 parasitoids were released from October, 1995 onwards.Acerophagus coccoisandAenasius vexanswere recovered up to 40 km from the release sites after three and five months of their initial releases, respectively. The establishment and dispersal of these parasitoids are discussed.
Insecticide-treated cattle for controlling tsetse flies (Diptera: Glossinidae): some questions answered, many posed
Authors: Vale G.A. , Mutika G. , Lovemore D.F. 
Published: November 2007

AbstractBioassays in Zimbabwe with wild-caught Glossina pallidipes Austen and G. morsitans morsitans Westwood showed that formulations of deltamethrin (Decatix, SpotOn and an experimental variant of SpotOn), alphacypermethrin (Renegade) and cyfluthrin (Cylence) applied to oxen at the manufacturers' recommended doses gave knockdowns above 50% for 5–24 days in hot months and 24–55 days at cooler seasons. Within these periods, the average knockdowns were 77–86% with deltamethrin, 74% with alphacypermethrin and 59% with cyfluthrin. None of the insecticides affected the numbers of tsetse attracted to oxen from a distance, the proportion of tsetse that engorged, and the alighting responses on cloth screens. In the hot season most tsetse engorged on the belly. At other times the front legs were preferred, especially in the wet season and for a few months after. Chemical assays indicated that insecticide persisted at greatest concentration on the backs of oxen and least on the legs. Modelling the experimental data suggested that 4–21 annual applications of insecticide in areas >1000 km2 would give good control at least 10 km from the invasion source if the treated cattle contributed at least 50% of tsetse diet. No treatment regime under any diet conditions would give good control near an invasion front. Insecticide at concentrations up to 0.15 ppm occurred in dung from treated oxen for up 12 days post-treatment. Dead beetles occurred in and near fresh dung.