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1.
The aim of this work is to investigate the presence of Coxiella burnetii in Perameles bougainville and their ticks on two islands off Western Australia. Haemaphysalis humerosa, Haemaphysalis ratti, and Haemaphysalis lagostrophi were collected from P. bougainville on Bernier and Dorre Islands from 2005 to 2007; only Amblyomma limbatum was collected from humans over the same interval. One of 13 tick samples and 1 of 12 P. bougainville fecal samples were positive for C. burnetii DNA using quantitative polymerase chain reaction. DNA fragments had >99% similarity to published C. burnetii sequences. Three of 35 P. bougainville sera tested positive for anti-C. burnetii antibodies using enzyme-linked immunosorbent assay. C. burnetii was found in P. bougainville feces and a H. humerosa tick on Dorre Island and Bernier Island, respectively. This is the first reported use of enzyme-linked immunosorbent assay for screening of P. bougainville sera. The risk of zoonotic Q fever infection for human visitors to these islands is considered relatively low, however, appropriate precautions should be taken when handling western barred bandicoots, their feces and their ticks on Bernier and Dorre Islands.  相似文献   

2.
Palaeoberesellids are septate, tubular microfossils usually attributed to the green algae. They occur widely in Upper Palaeozoic carbonate sediments, where they are normally seen in thin sections as cross-sections or short lengths of thallus. Detailed study of late Dinantian (Asbian) limestones from two areas of the UK. South Wales and northwest England, show that palaeoberesellids. particularly Kamaenella . are the most important carbonate-producing organisms in shallow. low to moderate energy environments and supplied grains to higher energy environments as a result of storm breakage and transport. Where palaeoberesellids were the dominant organisms they formed low-growing 'thickets' on the sea-floor which trapped fine sediment. to create a bafflestone texture. The late Dinantian was a time of great instability with rapid sea-level changes. Palaeoberesellids were opportunistic organisms which thrived in such an environment. The volume of carbonate produced by these organisms in shallow water may have been a contributory factor in the progradation of shallow marine facies and the establishment of relatively flat-topped shelves from the ramps of the Early Dinantian.  相似文献   

3.
The paper presents results of miospore studies on Carboniferous strata from drillings made in the last 20 years in several regions in marginal zones of the East-European Platform in Poland (Lublin Coal Basin, Warsaw, Płock, and Bydgoszcz regions, and western Pomerania). In that area the Carboniferous is represented by Dinantian and Silesian strata, from the Tournaisian to Westphalian D.Because of differences in geological development of the Carboniferous and in composition of microfloristic assemblages from strata of that age in the above mentioned regions the first stage of the studies had to be aimed at compilation of local palynostratigraphic schemes for individual regions. The next stage involved compilation of a regional palynostratigraphic scheme for the whole area of Polish margin of the East-European Platform. The scheme comprises 16 spore zones of the concurrent-range-zone type: 6 for the Dinantian and 10 for Silesian. The detailed characteristics of miospore assemblages and age correlations of the zones are given.The proposed scheme was subsequently compared with that proposed for the Carboniferous in western Europe. The comparison showed marked similarities in ranges of taxa diagnostic for individual stratigraphic units in both schemes.  相似文献   

4.
《Comptes Rendus Palevol》2005,4(1-2):109-121
Palaeoecological and palaeogeographical inferences from Early Carboniferous bivalves of the Ancenis Basin (Variscan belt, France). In the basal part of the Ancenis Formation, of Dinantian age, greenish to purple mudstones display a few bivalves, assigned to the genera Lithophaga, Modiolus, and Naiadites. Because Naiadites is considered to be a non-marine bivalve, and is only previously reported in Scotland in Dinantian rocks, a brackish environment can be assumed for the Ancenis Basin during the Early Carboniferous. To cite this article: M. Ballèvre, H. Lardeux, C. R. Palevol 4 (2005).  相似文献   

5.
Foraminifers from typical Kulm environments are described from 4 localities at the eastern and northern border of the Rhenish Massif: aQuasiendothyra fauna of uppermost Devonian age (Famennian); a Chernyshinellinae fauna of the lower Dinantian Cf1 Zone (middle Tournaisian); upper Dinantian foraminifers from the Cf4δ to Cf6γ Zones (Middle and Upper Viséan). The foraminifer assemblages of the Cf6 Zone (V3b + c), in theGoniatites crenistria schmidtianus toNeoglyphioceras spirale Subzones, seem to be variegated in Germany and Belgium, but they are definitively poorer than contemporaneous faunes in the British Isles and the Russian Platform.  相似文献   

6.
A bryozoan buildup from the Lower Carboniferous of North Wales   总被引:1,自引:0,他引:1  
A carbonate buildup dominated by trepostome Bryozoa is described from Dinantian (Asbian) strata near Llandudno in North Wales. A three-phase ecological succession is recognised within the buildup: (i) a basal diverse community with fenestrate, ramose, encrusting trepostome and cystoporate bryozoans in a mud rich wackestone; (ii) a bulk facies, dominated by encrusting and foliaceous, trepostome bryozoans in a fine packstone, and (iii) a thin capping phase, dominated by unilaminar, encrusting trepostome bryozoans in a slightly coarser lithology, including skeletal debris derived from the mound top and possible flanking beds. The buildup probably had topographic relief and developed in a shallow marine environment. The internal tripartite zonation reflects the growth of the structure into a shallower, higher energy regime, with the capping beds being deposited just below wave base. The buildup developed to the north of St. George's Land, on a carbonate shelf edge bordering the deeper basinal facies of the Irish Sea Basin. Dinantian, Asbian, buildup, trepostome Bryozoa, Foraminifera, corals, calcareous algae, Carboniferous, North Wales .  相似文献   

7.
Sylvie Crasquin 《Geobios》1984,17(3):341-351
The study of the distribution of Ostracode superfamiliesin the Dinantian of Northern France, Belgium and South Canadian Rockies leads us to establish a new Bairdiacean and Paraparchitacean ecozone. In a confined environment Kloedenellacea become more important. This association is characteristic of carbonate shelf sedimentation in warm climatic conditions. Russian and American bibliography strengthen our conclusions.  相似文献   

8.
The effect of tick infestations on body weight and various blood parameters was monitored in juvenile northern brown bandicoots (Isoodon macrourus) after release into tick-infested or tick-free enclosures. Three species of ticks were observed in the enclosures, Haemaphysalis humerosa, Ixodes tasmani and Ixodes holocyclus. Bandicoots released into tick-infested enclosures showed a reduced growth rate (1.8 versus 2.5 g/day increase in body weight), a reduced haematocrit value (27.4 versus 40.0%) and an increased number of white blood cells when compared with bandicoots released into tick-free enclosures. These results suggest that tick infestations may influence the health of juvenile I. macrourus.  相似文献   

9.
Upper Visean plant-bearing cherts have been discovered in association with others yielding a Stephanian A flora, in conglomerates (poudingue mosaïque) from the base of the Stephanian B at Grand'Croix. It confirms the distant source, from the Roanne region, of the Dinantian elements during the initial basin sedimentation and constitutes an excellent example of complex reworking of fossil plant material.  相似文献   

10.
Most carbonate buildups of Dinantian age are mud-mounds lacking direct evidence of abundant framework organisms. This contribution describes apparently unique structures containing abundant framebuilding organisms interpreted as true reefs. They occur in the Red Hill Oolite, part of the Carboniferous Limestone succession in the Furness area of northwest England. Reefs were initiated by the attachment of numerous Syringopora colonies to a firm substrate. Encrusting organisms, dominantly the supposed foraminifcr Aphralysia, colonised sediment and corallite surfaces leading to the development of a rigid framework. Thrombolites also assisted in the establishment of bindstone textures. During the later stages of reef growth, Syringopora became less common and its place in the reef was taken by upright, branching growths of solenoporoid algae. Rapid sedimentation and subsidence resulted in reefs with near vertical sides, but little topographic expression on the sea-floor during growth. The occurrence of these reefs cannot be attributed to any single environmental factor but probably resulted from an unusual combination of favourable circumstances. D Calcareous algae, Carboniferous, corals, Dinantian, foraminifera, reefs, thrombolites.  相似文献   

11.
CHALONER  W. G. 《Annals of botany》1958,22(2):197-204
A new type of fossil spore tetrad, Didymosporites scotti gen.et sp. nov. is described from the Dinantian and Namurian (Carboniferous)of Ireland, Scotland, and England. The spores always occur inthe form of a tetrad composed of two large (presumably fertile)and two minute (presumably abortive) spores, all with cutinizedwalls. Reasons are given for regarding these as the megasporesof the coenopterid fern Stauropteris burntislandica; their distributionindicates a far wider range in time and space than that previouslyknown for this species. Their occurrence as adhering tetradssuggests that Stauropteris burntislandica 'shed' its megasporesstill enclosed in the sporangiumIan interesting analogy withboth Lepidocarpon and the seeds of Pteridosperms.  相似文献   

12.
Dinantian carbonates of the Tournai and Dinant regions, southern Belgium, contain several trace fossil assemblages. These assemblages consist of the following ichnogenera:Cruziana, Rhizocorallium,Scalarituba, Scolicia, Skolithos, Phycosiphon, Planolites andZoophycos. Scalarituba andPhycosiphon are reported for the first time from the Carboniferous of Western Europe. The ichnofossils occur in discrete ichnofacies.Skolithos andZoophycos ichnofacies occur within the Ivorian (Upper Tournaisian). TheCruziana andSkolithos ichnofacies are found in the Moliniacian (Lower Visean). In the Dinant region, ichnofossils record a change from infauna to epifauna at the Ivorian-Moliniacian transition. Woodgrained chert is recognized and corresponds stratigraphically and palaeogeographically with those from the Western Interior United States.  相似文献   

13.
Talling  J. F.  Parker  J. E. 《Hydrobiologia》2002,487(1):153-165
Solute concentrations, including major plant nutrients, are surveyed from sampling during 1985–89 in river systems variably influenced by upland Dinantian (Carboniferous) limestone. Concentrations of most ions generally increase downstream, but there are widespread dilution effects after rainy periods for major ions and local depletions of mostly biological origin for major plant nutrients. In the upper reaches, these depletions develop mainly under low flow from the influence of benthic algae and macrophytes; they affect inorganic C as HCO3 - plus dissolved gaseous CO2 and soluble reactive forms of Si, N and P. Inflow – outflow differences of an upland lake result from biological influence on these constituents and also Ca+ and K+. Experimental injections of NH4-N, PO4-P and K+were made to an acid headwater of the River Swale, together with Na+ and Cl- as supposed conservative reference ions. Uptake is insignificant for K+ but marked for NH4-N and PO4-P; the residual percentage decreases exponentially with time. Relative rates of net uptake per unit time are greater for P than for NH4-N and larger under conditions of higher flow velocity and benthic algal growth. Although limestone is lacking in some headwater regions, where atmospheric inputs appear to predominate, overall its chemical denudation as Ca2+ and HCO3 -provides most of the solute flux downstream, as well as in some karstic headwaters where the highest values are limited by CaCO3 saturation.  相似文献   

14.
The study of the evolutionnary trend of the leaf architecture in the genus CallipteridiumWeiss, from the upper Westphalian and Stephanian, has allowed to determine, by extrapolation, the characters that had to show the frond of the direct ascendants which belong to the genus MargaritopterisGothan, from the Westphalian. This clue has led the quest on the field and has enabled the discovery of data which verify the correctness of the formulated hypothesis. This positive result and the evolutionnary trend ascertained by this new portion of the phylum led us to propose a new hypothesis about the characters of the fronds of the more ancient representatives of the phylum, that one can trace with great probability up to the lower Namurian and more hypothetically up to the Dinantian.This work has carried otherwise a revision of the corresponding species from the North of France and Sarre-Lorraine coal basins with a certain number of consequences about stratigraphical correlations.  相似文献   

15.
Hlinka O  Murrell A  Barker SC 《Heredity》2002,88(4):275-279
ITS2 sequences are used extensively in molecular taxonomy and population genetics of arthropods and other animals yet little is known about the molecular evolution of ITS2. We studied the secondary structure of ITS2 in species from each of the six main lineages of hard ticks (family Ixodidae). The ITS2 of these ticks varied in length from 679 bp in Ixodes scapularis to 1547 bp in Aponomma concolor. Nucleotide content varied also: the ITS2 of ticks from the Prostriata lineage (Ixodes spp.) had 46-49% GC whereas ITS2 sequences of ticks from the Metastriata lineage (all other hard ticks) had 61-62% GC. Despite variation in nucleotide sequence, the secondary structure of the ITS2 of all of these ticks apparently has five domains. Stems 1, 3, 4 and 5 of this secondary structure were obvious in all of the species studied. However, stem 2 was not always obvious despite the fact that it is flanked by highly conserved sequence motifs in the adjacent stems, stems 1 and 3. The ITS2 of hard ticks has apparently evolved mostly by increases and decreases in length of the nucleotide sequences, which caused increases, and decreases in the length of stems of the secondary structure. This is most obvious when stems of the secondary structures of the Prostriata (Ixodes spp.) are compared to those of the Metastriata (all other hard ticks). Increases in the size of the ITS2 may have been caused by replication slippage which generated large repeats, like those seen in Haemaphysalis humerosa and species from the Rhipicepalinae lineage, and the small repeats found in species from the other lineages of ticks.  相似文献   

16.
The characterization of expressed sequence tags (ESTs) generated from a cDNA library of Leishmania (Leishmania) amazonensis amastigotes is described. The sequencing of 93 clones generated new L. (L.) amazonensis ESTs from which 32% are not related to any other sequences in database and 68% presented significant similarities to known genes. The chromosome localization of some L. (L.) amazonensis ESTs was also determined in L. (L.) amazonensis and L. (L.) major. The characterization of these ESTs is suitable for the genome physical mapping, as well as for the identification of genes encoding cysteine proteinases implicated with protective immune responses in leishmaniasis.  相似文献   

17.
Callithrix penicillata is a good model for dermatotropic strains of some New World Leishmania species (L. mexicana mexicana, L. m. amazonensis, and L. braziliensis guyanensis). Both amastigotes and promastigotes readily infect these primates, with a relative short period of incubation. The developed lesions parallel those found in man, and despite the self healing presented by some marmosets, cell and serum immunological responses are presented. Skin alterations are confined to the site of inoculum, and visceralization is very rarely found. A good response to standard antimonial treatment makes the model useful for preclinical experiments with promising compounds.  相似文献   

18.
Platinum (IV) complexes [Pt (L)2Cl2] [where, L= benzyl-N-thiohydrazide (L1), (benzyl-N-thio)-1,3-propanediamine (L2), benzaldehyde-benzyl-N-thiohydrazone (L3) and salicylaldehyde-benzyl-N-thiohydrazone (L4)] have been synthesized. The thiohydrazide, thiodiamine and thiohydrazones can exist as thione-thiol tautomer and coordinate as a bidentate N-S ligand. The ligands were found to act in monobasic bidentate fashion. Analytical data reveal that metal to ligand stoichiometry is 1:2. The complexes have been characterized by elemental analysis, IR, mass, electronic and 1H NMR spectroscopic studies. In vitro antibacterial and cytotoxic studies have been carried out for some complexes. Various kinetic and thermodynamic parameters like order of reaction (n), activation energy (Ea), apparent activation entropy (S#) and heat of reaction (DeltaH) have also been carried out for some complexes.  相似文献   

19.
Antigenotoxic activity against 4-nitroquinoline-1-oxide (4-NQO) of lactic acid bacteria isolated from commercial dairy products was studied using SOS-Chromotest. The supernatants from bacteria-genotoxin co-incubations in general exhibited a strong suppression on SOS-induction produced by 4-NQO on the tester organism Escherichia coli PQ37 (sfiA::lacZ). High genotoxicity inhibition (>75%) was found for 31/67 of the examined bacteria and the maximum values of some strains within the species were as follows: Lactobacillus casei, 99.1%; L. plantarum, 93.3%; L. rhamnosus, 93.4%; L. acidophilus, 90.9%; L. delbrueckii subsp. bulgaricus, 85.7% and Bifidobacterium bifidum, 89.6%; Strains with low antigenotoxicity (5-60%) were evidenced in both L. acidophilus and L. delbrueckii subsp. bulgaricus, whereas some inactive strains were found only in L. casei and L. delbrueckii subsp. bulgaricus. Cell exposure to 100 degrees C for 15 min prevented antigenotoxicity and no effect was evidenced for cell-free spent media. The active strains survived at 0.1 mM 4-NQO exposure and generally presented some relevant functional properties, such as tolerance to bile (0.5%) or acid environment (pH 2.0) and adherence to Caco-2 enterocytes. Antigenotoxicity was always associated with modification of the 4-NQO absorbance profile.  相似文献   

20.
Attraction of various blowflies to sheep wool has been demonstrated under laboratory conditions using a choice-chamber technique. The attractive factor in wool is intimately associated with the wool fibre for it does not disappear during storage and it is not completely removed by washing.
Only female flies were attracted to wool. The highest degree of attraction was obtained from fertilized females which had daily access to meat. Even in the absence of fertilization and meat, attraction was not completely abolished.
The species and strains tested can be placed in the following order in terms of strength of response to sheep wool: Lucilia sericata (British), L. cuprina (tested on damp floor)>L. sericata (Danish: country)> L. sericata (Danish: city), L. sericata (Australian) > L. illustris, L. caesar. No response was given by Calliphora vomitoria.
The olfactory organs involved in the response to wool are mainly on the antennae but antennaeless L. sericata and L. cuprina with some tarsi removed were still able to show some response to wool provided that they were tested on a damp floor. In the course of testing the olfactory responses it was also shown that the main humidity receptors are present on the antennae.
The existence of a 'wool-factor' to which only certain strains of L. sericata and L. cuprina are specially sensitive offers a possible explanation for the greater efficiency of these species as myiasis-producing forms.  相似文献   

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