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1.
Middle to Late Cretaceous permineralized plants hitherto described from Hokkaido, Japan are summarized. The fossil flora comprises fungi, ferns, gymnosperms and angiosperms. Many modern fern families have been recognized including Anemiaceae, Cyatheaceae, Dennstaedtiaceae, Gleicheniaceae Loxsomaceae, Lygodiaceae and Matoniaceae. Gymnosperms are most abundant in the flora. Some recently-found materials are tentatively introduced with brief comments emphasizing their morphological and taxonomical significance. A bisporangiate flower ofCycadeoidella japonica Ogura shows fine internal anatomy and provides evidence that the cycadeoidalean ovule was a cupulate, unitegmic structure. Vascular tracheids in the synangial wall support the evolution of cycadeoidalean synangia from Paleozoic seed-fern synangia. A new gymnosperm female fructification has a thick envelope comparable to an angiosperm carpel around a large seed. The angiosperms contain various morphologies that require further extensive study.  相似文献   

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The effects of saponin fraction and its principal constituents escins Ia (1), Ib (2), IIa (3), and IIb (4) from horse chestnuts on gastrointestinal transit (GIT) and ileus were investigated in mice. Ileus was induced by acetic acid peritoneal irritation or by laparotomy with manipulation. One hour after the oral administration, the saponin fraction (12.5-100 mg/kg) and 14 (12.5-50 mg/ kg, except for 3 at 12.5 mg/kg) dose-dependently accelerated GIT. The optimal effects of the saponin fraction (25 mg/kg) occurred 5-240 min (applied intervals between the fraction and the charcoal meal) after the oral administration. The fraction (12.5-100 mg/ kg) and 1-4 (12.5-50 mg/kg, except for 1 and 2 at 12.5 mg/kg) dose-dependently prevented the inhibition of GIT induced by the acetic acid peritoneal irritation. They (12.5-100mg/kg) also dose-dependently prevented the inhibition of GIT induced by the laparotomy with manipulation. Desacylescins I (5) and II (6) (50 mg/kg) showed no such effects. These results demonstrated that the saponin fraction and 1-4 accelerated GIT and prevented the experimental ileus, and indicate that the 21, 22-acyl groups are essential for the accelerative effects of 1-4. The accelerations of GIT by 1-4 were completely abolished by the pretreatment with streptozotocin (100 mg/kg, iv), but not by the pretreatment with capsaicin (75 mg/kg in total, sc) or atropine (10 mg/kg, sc). These results imply that the sympathetic nervous system may be, but neither capsaicin-sensitive sensory nerves nor the cholinergic mechanism, involved in the accelerations of GIT by escins 1-4.  相似文献   

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Synapsins are key phosphoproteins in the mammalian brain, and structural research on synapsins is still holding center stage. Proteins were extracted from hippocampal tissue and separated on two-dimensional gel electrophoresis (2-DE), and the spots were analyzed by MALDI-TOF-TOF and nano-LC-ESI-MS/MS. Synapsins Ia, IIa, and IIb were unambiguously identified and represented by 15 individual spots on 2-DE. Several serine phosphorylation sites were confirmed, and a novel phosphorylation site was observed at Ser-546 in synapsin IIa in all gels analyzed.  相似文献   

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During the late Bronze age, settlements in Languedoc, southern France, were located on the shore of lagoons lining the Mediterranean, while, in the hinterland, settlements were mainly in the form of villages or cave sites. Information on food plants has been restricted, until now, to sites in the hinterland. In this paper, the archaeobotanical results obtained from two lagoon-shore settlements, La Fangade at Sète, and Portal Vielh at Vendres, are reported. The former provides the first waterlogged assemblage for this period in the French Mediterranean while the latter consists of a dry settlement. Emmer and hulled, six row barley are the most common cereals occurring at the two sites. Other cereals are less frequent, although einkorn chaff is common at La Fangade. Flax, and especially opium poppy, are well represented while faba bean is the only pulse of some importance. Many wild fruits were gathered, especially acorns. Comparison with data from the hinterland suggests that the main difference lay in the cultivation of opium poppy and flax in the lagoon sites. However, may be largely an impression, resulting from the differences in manner of preservation at hinterland and lagoon sites. Local production as distinct from importation of crops is considered and the conclusion is drawn that, at least at La Fangade, hulled barley was grown locally. The arable weed flora indicates that sowing took place during both autumn and spring at La Fangade.  相似文献   

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New fossil remains from the Tortonian of Scontrone (Abruzzo, Southern Italy) provide further information on crocodylids with a generalized rostral morphology that inhabited the Mediterranean area during the late Miocene. Particularly informative is the nearly complete right dentary SCT 276. Thanks to the fact that the third and fourth alveoli are clearly separated by a bony septum and are markedly different in size, the fourth being much larger than the third, it is possible to exclude that SCT 276 belonged to the alligatoroid Diplocynodon and to tentatively refer it to cf. Crocodylus sp. This genus has been previously identified on a phylogenetic basis in the same Apulo-Abruzzi palaeobioprovince (Gargano Terre Rosse, Messinian-Zanclean, Crocodylus sp.), and it is likely present also in the Tusco-Sardinian palaeobioprovince (Monte Bamboli, Tortonian, cf. Crocodylus sp.). SCT 276 currently represents the oldest possible evidence of the presence of Crocodylus; it proves that this taxon could have already reached Europe during the Tortonian, well before the Messinian Salinity Crisis that is traditionally considered as the event that caused several trans-Mediterranean dispersals. Furthermore, it is tempting to associate the absence of alligatoroids and the presence of crocodylids in these palaeobioprovinces (actually systems of islands) to the different behavioural, morphological and physiological traits of extant alligatorids and crocodylids, which render rather salt-intolerant the former and salt-tolerant the latter.  相似文献   

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Leuconostoc carnosum 4010 is a protective culture for meat products. It kills the foodborne pathogen Listeria monocytogenes by producing two class IIa (pediocin-like) bacteriocins, leucocin A and leucocin C. The genes for leucocin A production have previously been characterised from Leuconostoc gelidum UAL 187, whereas no genetic studies about leucocin C has been published. Here, we characterised the genes for the production of leucocins A and C in L. carnosum 4010. In this strain, leucocin A and leucocin C operons were localised in different plasmids. Unlike in L. gelidum, leucocin A operon in L. carnosum 4010 only contained the structural and the immunity genes lcaAB without transporter genes lcaECD. On the contrary, leucocin C cluster included two intact operons. Novel genes lecCI encode the leucocin C precursor and the 97-aa immunity protein LecI, respectively. LecI shares 48 % homology with the immunity proteins of sakacin P and listeriocin. Another leucocin C operon lecXTS, encoding an ABC transporter and an accessory protein, was 97 % identical with the leucocin A transporter operon lcaECD of L. gelidum. For heterologous expression of leucocin C in Lactococcus lactis, the mature part of the lecC gene was fused with the signal sequence of usp45 in the secretion vector pLEB690. L. lactis secreted leucocin C efficiently, as shown by large halos on lawns of L. monocytogenes and Leuconostoc mesenteroides indicators. The function of LecI was then demonstrated by expressing the gene lecI in L. monocytogenes. LecI-producing Listeria was less sensitive to leucocin C than the vector strain, thus corroborating the immunity function of LecI.  相似文献   

9.
The bacteriocin piscicocin CS526 was inactivated by proteolytic enzymes, was stable at 100 degrees C for 30 min, had a pH range of 2 to 8, and was active against Enterococcus, Listeria, Pediococcus, and Leuconostoc. The N-terminal sequence was YGNGL, not the YGNGV consensus motif common in class IIa bacteriocins (alternate residues underlined). The molecular mass of piscicocin CS526, which had a bactericidal mode of action, was approximately 4,430 Da.  相似文献   

10.
A large area investigation was undertaken of the plant remains from a Michelsberg Culture (late Neolithic) settlement. The charred macroscopic remains and imprints in pieces of daub were expected to show both the spectrum of the cultivated plants there, and also the degree of their cultivation and use. The loess covered hill-top lies in a landscape with favourable climatic and soil conditions and is blocked off by two parallel ditches running in an arc. Ditches and pits filled with different sediments were investigated. The daub, unearthed in several pits, had been deliberately mixed with chaff of the glume wheats einkorn and emmer to temper it when it was originally made. The investigated imprints and charred plant remains give hints of spatial distribution of crop processing activities. To determine the amounts of the crops that were cultivated and used, it is necessary to study the charred remains. The degree of ubiquity (frequency of occurrence) of grains in the pit sediments seems to be the best indicator of the representation of cereals. Four main cereals were found: Triticum monococcum, T. dicoccum, T. aestivum/T. durum and Hordeum vulgare var. nudum. Pisum sativum also was an important cultivated plant, much more than Lens culinaris. The role of Linum usitatissimum and Papaver somniferum is less clear.  相似文献   

11.
The archaeobotanical study of the charred macro-remains recovered from the burnt settlement of La Fontanaccia, Allumiere, 50 km northwest of Rome, a small hut from the time of the end of the late Roman Empire, provided results on the use of food of its inhabitants, their living conditions, and the natural environment. The fire which destroyed the small settlement was archaeologically dated to the middle of the 5th century a.d., few years before the end of the Roman Empire. This was a period in which the state structure, undermined by the barbarian invasions which provoked famine and destruction, was in deep economic and political crisis, and the population in Rome and in the countryside lived in precarious conditions. No archaeo-botanical data have been available until now for this period in the region of Rome. The presence of grass peas, acorns, two-rowed barley caryopses, and small horse bean seeds demonstrate the general state of regression in the late Roman Empire, when misery and famine were widespread. The finds of charcoal from chestnut, deciduous oak, maple and elm suggest the presence of thermophilous deciduous woods and environmental conditions similar to today’s. It deserves mention that this is the first site in which macro-remains (charcoal) of Castanea have been found in central Italy.  相似文献   

12.
《Palaeoworld》2021,30(3):551-561
Yunnan at southeastern margin of the Tibetan Plateau is subject to frequent wildfires each year, while its wildfire history remains poorly known due to the lack of studies on palaeofire in the region. In this study, we report a local fire from the late Pliocene of northwestern Yunnan, based on macroscopic fossil charcoals recovered from the Sanying Formation of Lanping Basin. These sedimentary charcoals exhibit silky lustre in the light and complete homogenization of adjacent xylem cell walls, characterizing the result of incomplete combustion during the late Pliocene. Our preliminary taxonomic analysis indicates that the studied charcoals are dominated by conifers, suggesting higher importance of coniferous elements as fuel sources in the fire. We assert a conifer-rich source forest for the fire event by also considering plant remains of other types, i.e., needle fragments, small shoots, fruits and seeds, from the same sampling layer. Since conifers are commonly prone to wildfires, this type of forest might have a close link with the fire by serving highly flammable fuels. We consider that the regionally seasonal drought during the late Pliocene might also take responsibility, because in the dry season forest fuels such as ground litter would become ignitable after intensive desiccation. As modern wildfires in northwestern Yunnan are closely coupled with conifer-dominant forests and seasonally dry climate, we assume this correlation might have been established by the late Pliocene. Our study may bring attention to potential roles of wildfire on local and/or regional flora and vegetation evolution in this region.  相似文献   

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Auxarthron californiense, Mixotrichum aeruginosum, Oncocladium flavum and Chaetomium elatum were recognized on the basis of ascomatal structures on the remains of a Longobard abbess who died in the IX century A.D. These fungi, which had remained isolated in a crypt of the S. Felice Monastery of Pavia for almost 1000 years, are phenotypically identical to the type specimens. The occurrence of these fungi and their ecological role are discussed. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

17.
Vegetative insecticidal protein (Vip) is a newly discovered family of toxin protein isolated from Bacillus thuringiensis (Bt). An 88.5-kDa Vip3Aa protein was secreted by a local strain of the bacterium during the vegetative growth phase. The full length of the coding region ‘2.3 kbp’ of the vip3Aa gene was isolated from plasmid DNA, cloned in pGEM-T vector and finally cloned in pQE-30 expression vector. Nucleotide sequence revealed 98% homology with that of the previously isolated genes. Expression of the vip3Aa in Escherichia coli was carried out and the expressed protein was detected in the concentrated supernatant, not in the pellet. This indicated that vip3Aa is secreted into the culture medium. Expressed protein was purified, blotted, and assayed against the cotton leaf worm Spodoptera littoralis. The LC50 was found to be 142.4 µ/mL while the LC50 was 90 ppm for the wild strain. These results suggest the use of either the isolated Bt strains or the expressed vip3Aa in an integrated pest management program against lepidopteran insect pests.  相似文献   

18.
The gene archb encoding for the cell-bound chitobiase from the Antarctic Gram-positive bacterium Arthrobacter sp. TAD20 was cloned and expressed in Escherichia coli in a soluble form. The mature chitobiase ArChb possesses four functionally independent domains: a catalytic domain stabilized by Ca(2+), a galactose-binding domain and an immunoglobulin-like domain followed by a cell-wall anchorage signal, typical of cell-surface proteins from Gram-positive bacteria. Binding of saccharides was analyzed by differential scanning calorimetry, allowing to distinguish unequivocally the catalytic domain from the galactose-binding domain and to study binding specificities. The results suggest that ArChb could play a role in bacterium attachment to natural hosts. Kinetic parameters of ArChb demonstrate perfect adaptation to catalysis at low temperatures, as shown by a low activation energy associated with unusually low K(m) and high k(cat) values. Thermodependence of these parameters indicates that discrete amino acid substitutions in the catalytic center have optimized the thermodynamic properties of weak interactions involved in substrate binding at low temperatures. Microcalorimetry also reveals that heat-lability, a general trait of psychrophilic enzymes, only affects the active site domain of ArChb.  相似文献   

19.
A new genus and species of cyprinid fishes,Aaptosyax grypus, is described from the middle Mekong River of Laos and Thailand, This large and rarely seen species reaches a full meter in length and lives in the main stem of the river. The species is a piscivore and the southernmost representative of the aspiin lineage. Among the aspiins it is unique in having a well-developed adipose eyelid and large symphyseal knob on the mandible which fits into a deep notch in the upper jaw.  相似文献   

20.
This paper describes the morphology of cervical vertebrae in Nacholapithecus kerioi, a middle Miocene primate species excavated from Nachola, Kenya in 1999-2002. The cervical vertebrae in Nacholapithecus are larger than those of Papio cynocephalus. They are more robust relative to more caudal vertebral bones. Since Nacholapithecus had large forelimbs, it is assumed that strong cervical vertebrae would have been required to resist muscle reaction forces during locomotion. On the other hand, the vertebral foramen of the lower cervical vertebrae in Nacholapithecus is almost the same size as or smaller than that of P. cynocephalus. Atlas specimens of Nacholapithecus resemble those of extant great apes with regard to the superior articular facet, and they have an anterior tubercle trait intermediate between that of extant apes and other primate species. Nacholapithecus has a relatively short and thick dens on the axis, similar to those of extant great apes and the axis body shape is intermediate between that of extant apes and other primates. Moreover, an intermediate trait between extant great apes and other primate species has been indicated with regard to the angle between the prezygapophyseal articular facets of the axis in Nacholapithecus. Although the atlas of Nacholapithecus is inferred as having a primitive morphology (i.e., possessing a lateral bridge), the shape of the atlas and axis leads to speculation that locomotion or posture in Nacholapithecus involved more orthograde behavior similar to that of extant apes, and, in so far as cervical vertebral morphology is concerned, it is thought that Nacholapithecus was incipiently specialized toward the characteristics of extant hominoids.  相似文献   

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