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1.
Lessmann  Dieter  Fyson  Andrew  Nixdorf  Brigitte 《Hydrobiologia》2000,433(1-3):123-128
Most of the flooded, open-cast lignite mining lakes of Lusatia (Germany) impacted by the oxidation of iron sulphides (pyrite and marcasite) are extremely acidic. Of 32 lakes regularly studied from 1995 to 1998, 14 have a pH <3 (median pH 2.3–2.9). These lakes are typically buffered by high concentrations of Fe (III) and have high conductivity (1000–5000 S cm–1). Concentrations of dissolved inorganic carbon (DIC) and phosphorus are typically extremely low. These factors result in a very different environment for algae than found in neutral and acid-rain impacted lakes. The planktonic algal flora is generally dominated by flagellates belonging to genera of Chlorophyta (Chlamydomonas), Heterokontophyta of the class Chrysophyceae (Ochromonas, Chromulina), Cryptophyta (Cyathomonas) and Euglenophyta (Lepocinclis, Euglena mutabilis). Near-spherical non-motile Chlorophyta (Nanochlorum sp.), Heterokontophyta of the class Bacillariophyceae (Eunotia exigua, Nitzschia), Dinophyta (Gymnodinium, Peridinium umbonatum), other Chlorophyta (Scourfieldia cordiformis) and Cryptophyta (Rhodomonas minuta) are also found.  相似文献   

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In this study, we revise the lace bugs (family Tingidae) from the Ogasawara Islands, Japan (also known as the “Oriental Galapagos”). Three species belonging to two endemic genera are recognized: Acanthomoplax tomokunii gen. et sp. nov. , Omoplax desecta (Horváth, 1912), and O. majorcarinae Guilbert, 2001. A key to species is provided to facilitate the identification of Ogasawaran lace bugs.  相似文献   

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The ‘R-bodies’ of Caedibacter taeniospiralis, an endosymbiont of Paramecium tetraurelia and Pseudomonas avenae, have been examined under a wide range of pH. They both unroll over a small range, but in both cases the process does not always proceed to completion. Acid pHs cause both to unroll. All the R-bodies of P. avenae at high pHs are wound which is not the case with Caedibacter. There are differences between the two bodies in the details of their unrolling. Caedibacter taenospiralis unwinds from the inside, whereas P. avenae unwinds from the outside. Detailed study of the unwound ribbon shows a difference in terms of roughness and smoothness of the two surfaces.  相似文献   

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Occurrence of high-level mupirocin resistance in methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from 18 hospitals in Gdańsk area was determined. The study was carried out on 190 MRSA isolated in 1997-2000 from various clinical samples. The strains were tested for high-level mupirocin resistance by 200 micrograms mupirocin disc. The minimum inhibitory concentrations (MIC) for methicillin were estimated by agar dilution. Sensitivity to other antibiotics was determined in disc-diffusion method and to vancomycin in agar dilution method additionally. The strains were typed by set of 10 experimental phages and compared by the method of PCR-RFLP analysis of coagulase gen restriction fragment length polymorphism. There were low frequency of high-level mupirocin resistance in MRSA strains (4.7%) that were found only in 3 hospitals, in 6 patients. All of them were high-resistant also to methicillin and resistant to doxycyclin, gentamycin, erytromycin, klindamycin, ciprofloksacin, rifampicin, resistant or intermediate sensitive to fusidic acid but sensitive to vancomycin, teikoplanin and bacitracin. The origin all of the MRSA strains high-resistant to mupirocin probably was the same, except one strain, because they were belonged to one genetic type and possessed the same phage pattern.  相似文献   

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Acidithiobacillus ferrooxidans is an acidophilic chemolithotrophic bacterium that can grow in the presence of either a weak reductant, Fe(2+), or reducing sulfur compounds that provide more energy for growth than Fe(2+). Here we first review the latest findings about the uphill electron transfer pathway established in iron-grown A. ferrooxidans, which has been found to involve a bc(1) complex. We then provide evidence that this bc(1) complex cannot function in the forward direction (exergonic reaction), even with an appropriate substrate. A search for the sequence of the three redox subunits of the A. ferrooxidans bc(1) complex (strain ATCC 19859) in the complete genome sequence of the A. ferrooxidans ATCC 23270 strain showed the existence of two different bc(1) complexes in A. ferrooxidans. Cytochrome b and Rieske protein sequence comparisons allowed us to point out some sequence particularities of these proteins in A. ferrooxidans. Lastly, we discuss the possible reasons for the existence of two different "classical" bc(1) complexes and put forward some suggestions as to what role these putative complexes may play in this acidophilic chemolithotrophic bacterium.  相似文献   

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Hydrophylax, a genus of maritime strand or dune plants, was previously thought to comprise three species, one from India, Sri Lanka and Thailand (H. maritima), and two from Africa and Madagascar (H. carnosa and H. madagascariensis respectively). Evidence is presented that the African and Madagascan species are better placed into a separate genus (Phylohydrax). Differential characters betweenH. maritima andP. carnosa—P. madagascariensis, the relationships between the three species, and the affinities ofPhylohydrax andHydrophylax to otherSpermacoceae are discussed in detail.  相似文献   

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Tapinoma wilsonisp. n. is described and illustrated from Saudi Arabia based on the worker caste collected from Al Baha, Saudi Arabia. It closely resembles Tapinoma lugubre Santschi 1917, from Zimbabwe in body measurements but can be distinguished from the latter species by the yellowish brown color; the yellowish pubescence, the two pairs of hairs present on the anterior part of the head; and the distinctly concave anterior clypeal margin. Biological and ecological notes of the new species are presented. An identification key to the workers of the Arabian species of the genus Tapinoma is given.  相似文献   

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Two new species of the new genus Athaumaspis gen. n., Athaumaspis minutus sp. n. and Athaumaspis tibetanus sp. n. from Vietnam and China are described. The subgenus Pseudothaumaspis of Thaumaspis is elevated to generic status and another two new species Pseudothaumaspis bispinosus sp. n. and Pseudothaumaspis furcocercus sp. n. are described, the remaining species of Thaumaspis are reviewed and keyed with the four new species.  相似文献   

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Many group-living mammals and birds give both contact and distress calls. Contact calls are thought to operate in maintaining group stability and cohesion; distress calls are thought to operate in soliciting help, often from relatives. Here we propose that a single call of black-and-gold howlers (Alouatta caraya) serves both needs, but differently so during ontogeny. We collected data on the contexts of moo calling: on group diameter before, during, and after calling; and on calling rates before and after potentially stressful events or situations. Several relationships suggested a link between moo calling and group cohesion. The highest calling rates were found during travel, when separation is most likely, whereas rates were significantly lower during feeding, a sedentary activity. During periods of moo calling, group spread was significantly greater than normal, and spread decreased significantly after calling began. Moo calls were also given in situations of potential distress. When reluctant to cross an arboreal gap or refused the option of travel on an adult, infants gave moo calls more frequently than just after these predicaments were ended; infants also called more frequently immediately after a behavioral conflict. The moo call apparently has a dual role, in contact and distress, with the signal’s use changing with caller age: both uses may reflect a common underlying motivation of insecurity, as different contexts come to trigger insecurity during development.  相似文献   

16.
Sheng ML  Broad GR  Sun SP 《ZooKeys》2011,(141):53-64
Three species of Ateleute Förster 1869 belonging to the tribe Cryptini of the subfamily Cryptinae (Hymenoptera, Ichneumonidae), collected from Jiangxi Province, China, are reported, of which two are new for science: Ateleute ferruginea Sheng, Broad & Sun, sp. n. and AAteleute zixiensis Sheng, Broad & Sun, sp. n. One, AAteleute densistriata (Uchida, 1955), was previously known from China and Japan. A key to the species of genus Ateleute known in the Oriental Region is provided.  相似文献   

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Summary South American male toads Bufo chilensis emit a release call in contact with other individuals and a soft amplectic call, B. spinulosus males emit a release call while isolated in breeding areas, and B. arenarum produces a release call plus an intense mating call. Release calls of the 3 species measure 72–86 dB SPL RMS at 20 cm in front of the animal and the mating call of B. arenarum is 84–87 dB SPL at 4 m.Audiograms obtained with multiunit recordings in the torus semicircularis (TS) show a low frequency region (LFR), centered at 352, 356 and 491 Hz, and a high frequency region (HFR), centered at 1199, 1161 and 1423 Hz, in B. chilensis, B. spinulosus and B. arenarum, respectively. Center frequencies (CFs) in the HFR are in gross correspondence with average dominant frequencies (DFs) of the vocalizations of these species. Best thresholds (BTs) in the HFR are similar between B. chilensis and B. arenarum while in B. spinulosus average BTs are 10.8 and 13.5 dB higher, respectively. The similar auditory thresholds between B. chilensis and B. arenarum denote a conservative nature of auditory sensitivity among these anura.Abbreviations AP amphibian papilla - BP basilar papilla - BT best threshold - CF center frequency - DF dominant frequency - HFR high frequency region - LFR low frequency region - TS torus semi-circularis - SPL sound pressure level  相似文献   

18.
Sheng ML  Zeng XF 《ZooKeys》2010,(57):63-73
Four species of Mastrus Förster, 1869 are reported from China. Two, Mastrus nigrus Sheng & Zeng, sp. n. reared from Arge pullata (Zaddach) and Mastrus rugotergalis Sheng & Zeng, sp. n. reared from Diprion jingyuanensis Xiao & Zhang, are new to science. One, Mastrus deminuens (Hartig, 1838), is a parasitoid of Pachynematus itoi Okutani. A key to species of Mastrus Förster known in China is provided.  相似文献   

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A checklist of 39 species of the genus Tomosvaryella Aczél (Diptera, Pipunculidae) known from the Middle East is provided. A new species, T. hamata Majnon Jahromi &; Kehlmaier sp. n. is described from southern Iran and diagnostic characters of male and female terminalia are illustrated. Tomosvaryella dentiterebra (Collin, 1949 Collin, J. E. (1949): Results of the Armstrong College Expedition to Siwa Oasis (Libyan Desert), 1935, under the leadership of Prof. J. Orner-Cooper. Diptera Empididae, Dolichopodidae, Aschiza and Acalypterae. Bulletin de la Societe Fouad Ierd'Entomologie, 33, 75225. [Google Scholar]) is redescribed and male and female terminalia are illustrated for the first time. A phylogenetic maximum-likelihood analysis and uncorrected pairwise genetic distances of 18 out of 22 Iranian species of Tomosvaryella based on DNA barcodes of the mitochondrial COI gene are presented and also discussed.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:FF8C116D-0C92-431A-B52C-11F3711B6A62  相似文献   

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