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1.
典型抗生素复合污染对小白菜生长发育的毒理效应   总被引:2,自引:0,他引:2  
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鱼道过鱼效果监测方法述评   总被引:1,自引:0,他引:1  
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During a one year period, 944 dogs from the Municipal kennel of Barcelona were examined to detect animals with suspected dermatophytosis. Only a few animals (1.8%) presented skin lesions but none of them had dermatophytosis. A representative number of dogs without visible skin lesions (n=172), selected at random, were used to carry out a seasonal study of the mycobiota of their fur. Fifteen isolates belonging to the genera Microsporum and Trichophyton were isolated from 14 of the 172 (8.1%) dogs without lesions. The identity of these fungi was Microsporum gypseum (6/15), Trichophyton terrestre (4/15), M. canis (2/15), M. cookei (2/15) and Trichophyton ajelloi (1/15) (one strain each of M. gypseum and T. ajelloi were isolated from one dog). Species of Penicillium (% prevalence=89.5%), Alternaria (86.6%), Cladosporium (84.9%), Aspergillus (77.3%), Scopulariopsis (65.7%) and Chrysosporium (64.5%) were the most prevalent. No significant differences in the fungal biota were observed with respect to age, gender, hair length or between mixed and pure breed dogs. A large number of isolates, including species belonging to the genera Beauveria, Chrysosporium, Malbranchea and Scopulariopsis, that macroscopically and/or microscopically resemble dermatophytes and may be mistaken for them, produced a red color change in Dermatophyte Test Medium. No significant seasonal difference was detected among the isolates belonging to the the most frequently encountered genera, with the exception of Scopulariopsis (higher in summer and autumn) and Chrysosporium (higher in summer). Species from other genera, with lower occurrence also presented significant differences in their seasonal distribution. Arthrinium, Aureobasidium, Chaetomium and Phoma spp. presented maximum prevalence peaks in spring, Fusarium, Paecilomyces, Phoma and Rhizopus spp. in summer and Geotrichum and Mucor spp. in autumn. The Microsporum and Trichophyton species were more frequently isolated in summer.  相似文献   

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In this study, the spatial distribution of brood-bearing females of five species of limnetic cladocerans (Daphnia cucullata, D. longispina, Bosmina coregoni, B. longirostris, Diaphanosoma brachyurum) in the deep mesotrophic lake in relation to the predation pressure of planktivorous fish (roach Rutilus rutilus, perch Perca fluviatilis, catfish Ictalurus nebulosus, white fish Coregonus albula, bleak Alburnus alburnus), and planktonic invertebrates (cyclopoids Mesocyclops leuckartii, Thermocyclops oithonoides, T. crassus, and cladoceran Leptodora kindtii) as well as some environmental variables was estimated. Most cladocerans showed apparent differences in horizontal distribution (ANOVA F = 0.2–0.45, P < 0.05) in the littoral zone and lack of such differences in the pelagic zone (F = 0.07–0.13, P > 0.05). Vertical distribution of most species, in turn, showed a clear pattern in the pelagic zone (F = 0.31–0.39, P < 0.05) and less regularities in the littoral zone (F = 0.15–029, P > 0.05). The differences in spatial distribution of non-predated and predated species suggest that predation pressure, but not predatory type, was an important factor structuring their distribution. Other factors that affected their distribution were conductivity, dissolved oxygen, TOC and macrophyte biomass; however, most of those variables better explained the distribution of brood-bearing cladocerans in the vertical than horizontal aspect.  相似文献   

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Radioiodination of highly purified human follicle-stimulating hormone (hFSH) (4000 IU/mg) was performed every other week for 23 weeks using 2 mCi carrier free Na 125I (Amersham Corp., 15 mCi/μg I2) in the presence of lactoperoxidase. Incorporation of 125I into hFSH was determined by the method of [7.]Biochem. J. 89, 114). Hormone binding was studied in vitro under steady-state conditions (16 h, 20°C) using different calf testis membrane preparations having similar receptor characteristics. Each 125I-hFSH preparation was characterized for maximum bindability, specific activity of bindable radioligand as determined by self-displacement analysis, and by determination of Ka and Rt. Incorporation of 125I into FSH was relatively constant over the large number of experiments (62.4 ± 6.4 μCi/μg; n = 23). By comparison, however, specific radioactivity of the receptor bindable fraction of 125I-hFSH was related to the lot of 125I utilized, and was significantly (P ≤ 0.01) lower and more variable (28.7 ± 10.5 μCi/μg). Maximum bindability of 125I-hFSH was not correlated to specific activity (r = 0.06) but was negatively correlated to hFSH 125I incorporation (r = −0.47; P ≤ 0.05). These observations demonstrate the need to assess the quality of each batch of radioligand before undertaking radioligand-receptor assays and suggest that differences in Na125I lots affect specific radioactivity of the radioligand and its receptor binding characteristics.  相似文献   

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Genomes of various hyperthermophilic and extremely thermophilic prokaryotes were analyzed with respect to size, physical organization, and 16S rDNA copy number. Our results show that all the genomes are circular, and they are in the size range of 1.6–1.8 Mb for Pyrodictium abyssi, Methanococcus igneus, Pyrobaculum aerophilum, Archaeoglobus fulgidus, Archaeoglobus lithotrophicus, and Archaeoglobus profundus (the two bacteria Fervidobacterium islandicum and Thermosipho africanus possess genomes of 1.5-Mb size). A systematic study of all validly described species of the order Sulfolobales revealed the existence of two classes of genome size for these archaea, correlating with phylogenetic analyses. The Metallosphaera–Acidianus group, plus Sulfolobus metallicus, have genomes of ca. 1.9 Mb; the other members of the order Sulfolobales group possess genomes >2.7 Mb. The special case of Stygiolobus azoricus is discussed. Received: August 10, 1997 / Accepted: January 1, 1998  相似文献   

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The duration of larval and pupal stages of two species of predatory flies was investigated at five constant temperatures. Ilione albiseta (Scopoli): Mean duration of first and second instars was shortest at 23°C and there was 100% survival of first instar larvae at all temperatures. Mean third instar larval duration decreased from 104 days at 17°C to 27.5 days at 26°C. Total percentage larval survival was greatest at 17°C and least at 26°C. Mean pupal duration decreased as temperature increased and this occurred also under outdoor conditions. Pherbellia cinerella (Fallén): As temperature increased mean larval duration decreased but the percentage of larvae pupating also decreased (100% at 14°C, 33.3% at 26°C). There was a trend for shorter mean pupal durations at higher temperatures.
Résumé L'action de la température a été examinée à 14, 17, 20, 23 et 26°C. Les 2 espèces sont prédatrices de L. truncatula, vecteur de la douve du foie en Irlande, où elle provoque à l'àgriculture une perte évaluée à 10 millions de livres par an. Les données recuellies en conditions contrôlées du laboratoire doivent permettre de définir les conditions optimales pour l'élevage continu de ces espèces. Ceci est indispensable pour évaluer, dans la nature leurs potentialités pour la lutte biologique. Ilione albiseta: C'est à 23°C que le développement des larves de premier et second stades sont les plus brefs; la survie du premier stade est totale à toutes les températures constantes examinées. La durée moyenne du 3ème stade décroît de 104 jours à 17°C jusqu'à 27,5 jours à 26°C. Le taux de survie total est plus élevé à 17°C qu'à 26°C. La durée moyenne de la nymphose diminue quand la température croît, et ceci se produit aussi à la température ambiante extérieure. On réduit de moitié la durée du développement de l'éclosion de l'oeuf à l'apparition de l'adulte, entre la nature et le laboratoire, en utilisant respectivement: 23°, 17° et 26°C pour les premier et second stades, le troisième stade, la nymphé. Cela devrait aider à multiplier la souche pour la lutte biologique. Pherbellia cinerella: Avec élévation de la température la durée du développement larvaire diminue, mais aussi le nombre de larves parvenant à la pupaison (100% à 14° et 33,3% à 26°C). La nymphose tendait à être plus brève aux températures les plus élevées.
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F1-ATPase was isolated from yeast S.cerevisiae. The constituent subunits 1 and 2 were purified by gel permeation chromatography, and their amino acid compositions determined. Both subunits have a similar composition except for 12 cystine, methionine, leucine, histidine, and tryptophan. When F1 is treated for three hours with 5′-p-[3H]fluorosulfonylbenzoyl adenosine in dimethylsulfoxide, 90% of the activity is lost. Disc gel electrophoresis of the modified complex showed that over 90% of the label was associated with subunit 2. A labelled peptide from a S.aureus digest of subunit 2 was isolated and sequenced. It had the following amino acid sequence: His-Try1-Asp-Val-Ala-Ser-Lys-Val-Gln-Glu, whereby Tyr1 is the modified amino acid residue. This sequence shows homology to other sequences obtained from maize, beef heart, and E.coli F1-ATPases.  相似文献   

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This paper presents the mitotic chromosome numbers of 18 species of Bromeliaceae. The diploid number 2n = 50 was observed in Aechmea comata, A. caudata, A. correia‐araujoi, A. recurvata, A. marauensis, A. bicolor, A. pineliana, Hohenbergia catingae, H. blanchetti, Alcantarea imperialis, Al. nahoumi, Neoregelia tenebrosa, Nidularium lyman‐smithii, N. scheremetiewii, N. innocentii var. innocentii, and N. innocentii × Neoregelia johannis hybrid, whereas 2n = 34 was observed in Cryptanthus maritimus and C. warren‐loosei. All of the determinations presented in this study are previously unpublished, except A. comata and H. catingae. These results confirm x = 25 as the basic number for the family and x = 17 as a secondary basic number probably generated by decreasing dysploidy. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 189–193.  相似文献   

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Despite the progress in studies of the properties and functions of low-threshold calcium channels (LTCCs) [1], the mechanisms of their selectivity and permeability remain unstudied in detail. We performed a comparative analysis of the selectivity of three cloned pore-forming LTCC subunits (α1G, α1H, and α1I) functionally expressed in Xenopus oocytes with respect to bivalent alkaline-earth metal cations (Ba2+, Ca2+, and Sr2+. The relative conductivities (G) of these channels were determined according to the amplitudes of macroscopic currents (I) and potentials of zero currents (E). The currents were recorded after preliminary intracellular injection of a fast calcium buffer, BAPTA, in order to suppress the endogenous calcium-dependent chloride conductivity. Channels formed by α1G subunits demonstrated the following ratios of the amplitudes of macroscopic currents and potentials of zero current: I Ca:I Ba:I Sr = 1.00:0.75:1.12 and E CaE BaE Sr. For channels that were formed by α1H and α1I subunits, these ratios were as follows: I Ca:I Ba:I Sr = 1.00:1.20:1.17, E CaE BaE Sr and I Ca:I Ba:I Sr = 1.00:1.48: 1.45, E CaE BaE Sr respectively. The different macroscopic conductivities and similar potentials of zero current typical of α1G and α1I channels indicate that, probably, various bivalent cations can in a differential manner influence the stochastic parameters of functioning of these channels. At the same time, channels formed by α1H subunits are characterized by more positive potentials of zero current for Ca2+. It seems possible that the selectivity of the above channels is determined by mechanisms that mediate the selectivity of most high-threshold calcium channels (more affine binding of Ca2+ inside the pore). Neirofiziologiya/Neurophysiology, Vol. 37, No. 4, pp. 319–329, July–August, 2005.  相似文献   

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Leaf material of two Piper spp. (Piperaceae) was presented to two different generalist herbivores (Orthoptera: Acrididae) to determine whether method of leaf presentation in preference trials affects choice. For the grasshopper Leptomerinthoprora brevipennis, the method of presentation had no effect on preference ranking: more of Piper sancti-felicis was eaten than of P. arieianum, regardless of whether leaf material was presented as leaf disks, whole leaves supplemented with water, or whole leaves without water. In contrast, preference of the grasshopper Abracis flavolineata depended on presentation method. In that case, whole leaves of P. scancti-felicis supplemented with water were preferred over the same of P. arieianum, while dry weight consumption of leaf disks of P. arieianum was greater than that for disks of P. sancti-felicis. When presented with leaves not supplemented with water, A. flavolineata showed no significant preference for one plant species over another.
Résumé Des feuilles provenant de deux espèces de Piper (Piperacae) ont été proposées à deux Orthoptères, Acrididae, herbivores généralistes, pour déterminer si la méthode de présentation des feuilles modifiait le choix. Pour Leptomerinthoprora brevipennis, la méthode de présentation est sans influence sur l'ordre de préférence; la consommation de Piper sancti-felicis est toujours supérieure à celle de P. arieianum, quelque soit le mode de présentation: disques de feuilles, feuilles entières humidifiées, ou feuilles entières sans addition d'eau. A l'opposé, l'ordre de préférence de Abracis flavolineata dépend du type de présentation; les feuilles entières humidifiées de P. sancti-felicis sont préférées à celles de P. arieianum proposées de la même façon, tandis que la consommation de disques secs de P. arieianum est plus importante que celle des disques secs de P. sancti-felicis. En présence de feuilles entières humidifiées, A. flavolineata ne manifeste aucune préférence.
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The palynological characterisation of 157 honey samples from three northwest regions of Argentina (Prepuna, Yungas and Chaco) are presented to determine their botanical origin and species associations to be able to define their geographic origin. Samples were harvested during 2003–2011 and processed by means of melissopalynological conventional techniques. One-hundred and nine pollen types were identified. Representative pollen types with a frequency of occurrence greater than 50% in descending order of importance are: Salix humboldtiana, Allophylus edulis, Baccharis, Solanaceae, Eucalyptus, Schinus, Brassicaceae, Papilionoideae, Celtis, Scutia/Condalia-type and Parapiptadenia excelsa. The most important monofloral honeys are from the following: Salix humboldtiana, Scutia/Condalia-type, Allophylus edulis, Baccharis, Blepharocalyx salicifolius, Gleditsia amorphoides, Myrtaceae, Sicyos, Ziziphus mistol, Schinopsis-type, Agonandra excelsa, Anadenathera colubrina, Mimosa, all of them native species, and among introduced species are Eucalyptus, Citrus and Tithonia. Three apicultural zones and their corresponding pollen association indicators were determined: Zone I, Prepuna: Arquita trichocarpa, Prosopis ferox, Schinus areira, Baccharis, Buddleja and Mutisieae; Zone II, Yungas: Myrtaceae, Parapiptadenia excelsa, Baccharis, Salix humboldtiana, Allophylus edulis, Scutia/Condalia-type and Zanthoxylum coco; Zone III, transitional area Yungas-Chaco: Prosopis, Salix humboldtiana, Schinus, Anadenanthera colubrina and Allophylus edulis.  相似文献   

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