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1.
In Korea, Quaternary deposits are characterized by marine and fluvial terrace deposits, commonly found in the coastal areas and at the sides of river valleys. The major terraces are classified into 5 different levels, i.e., alluvial plain (3-5 m asl), lower terrace (10-25 m asl), middle terrace (33-50 m asl), high terrace (55-85 m asl), and highest terrace (90-160 m asl). They were formed by the repetition of sedimentation and erosion due to sea level fluctuation and uplifting along the coastal areas during Quaternary period. The formation age of the lower marine terraces at the level of 10-20 m is interpreted to be the last interglacial (75-125 Ka, MIS = 5a-5e). The middle coastal terrace gravels distributed at the level of about 33-45 m above mean sea level and are to be formed before the last interglacial. Above coastal terrace deposits, slope deposits and paleosol layers are overlain and freezing and thawing crackings were developed in them. Major prehistory archaeological sites in the coastal areas are found in the slope deposits formed during last glaciations. The upper parts of the slope deposits are typified by paleosol layers with typical frost cracks (soil wedges) and frangipanes. As geochronological bases for subdividing Paleolithic cultures, two typical paleosol layers are useful because they are mostly found and imprinted with several horizons of frost cracks or soil wedges. The uppermost crack structures were formed under the boreal-periglacial climatic regime during the last glacial period of extremely cold-dry climate in Korea. The upper pedogenetic sediments containing frost cracks or soil wedges were formed between 24 and 17 Ka in many Paleolithic profiles. The lowermost paleosol layer with frost cracks (soil wedge), strongly attacked into hillslope sediments or last interglacial saprolite layers on the weathered basement rocks, were detected at least as old as 59-74,000 Ka. Lastly upper Paleolithic cultural layers were found in the young fluvial deposits, which had been formed since the Last Glacial Maximum (LGM). Some of them were particularly continued as late as the Pleistocene-Holocene Transition Period.  相似文献   

2.
Hundreds samples of the charcoals and waterlogged woods excavated from three late Paleolithic sites (Suyanggae, Gunang-gul and Sorori) in the Jungwon Region in Korea were analyzed to reconstruct the vegetation and paleoclimate in the region. Analyzed charcoal samples from the Suyanggae site show that the climate was cold in the lower part and it became more warm and dry in the upper part. From the Gunang-gul site, only Picea spp. was identified, indicating cool climates. From the Sorori site, two species were found; Alnus spp. (95%) and Ulmus spp. (5%). No conifers were discovered. The species composition indicates that the climate condition of central Korean peninsula around 8,800 BP was little cooler and wetter condition.  相似文献   

3.
The El Harhoura 2 cave is situated in the commune of El Harhoura in the Temara region (Morocco). The entrance faces west, towards the ocean, around 200 m away from the current shoreline and about 16 m above sea level. The stratigraphy has currently 11 levels numbered from top to bottom. Level 1 is attributed to the early Neolithic. The archaeological material from level 2 places it within the Upper Palaeolithic (Iberomaurusian). Levels 3 to 11 are assigned to the Middle Palaeolithic (Aterian). Since 1977, a surface of 37 m2 has been excavated, yielding particularly abundant remains of a large mammal fauna study in this paper.  相似文献   

4.
Columba livia is an important reservoir and carrier of Cryptococcus neoformans, Cryptococcus uniguttulatus, Cryptococcus laurentii and Cryptococcus albidus. Upper digestive tract of this species is also known as a habitat for Cryptococcus neoformans. Given the increasing clinical interest of this microorganism, 331 swabs from crop and 174 dropping samples from pigeon lofts in Grand Canary Island have been studied. The obtained results show an extensive presence samples 81 positive (24.47%) of Cryptococcus spp. in analysed crops: 32 (9.66%) for C. neoformans, 24 (7.2%) for C. uniguttulatus, 23 (6.9%) for C. albidus and 2 (0.6%) for C. laurentii. In the same way, Cryptococcus spp was also isolated in 82 (47.13%), dropping samples: C. neoformans in 59 (33.9%), C. uniguttulatus, in 9 (5.17%), C. laurentii in 8 (4.59%) and C. albidus in 6 (3.44%) of the investigated samples, respectively. The cryptococcosis produced by species of cryptococci other than C. neoformans has become more important during the last decade, supporting the study on the role of pigeon in the epidemiology of this disease.  相似文献   

5.
The effect of different cadmium concentrations (6–120 μM) on Hill reaction activity (HRA) of isolated chloroplasts, contents of chlorophylls (Chls) and carotenoids (Cars), and Cd uptake and accumulation in plant organs of Indian mustard (Brassica juncea L. cv. Vitasso) and mung bean [Vigna radiata (L.) Wilczek] were determined. The Cd stress inhibited photochemical activity of isolated chloroplasts of both species and in both tested developmental stages. On the basis of EC50 values, the mung bean showed a higher sensitivity to Cd treatment than Indian mustard. The higher sensitivity of both species was determined in the earlier than in the older developmental stage. The leaves of Cd-treated plants possessed lower contents of Chls and Cars in both species and the negative effect increased with Cd concentration. A difference between species was also found in Cd uptake and accumulation. In both species, Cd was accumulated more in roots than in shoots, with higher accumulation in Indian mustard than in mung bean.  相似文献   

6.
We present data on the habitat, density, and spatial distribution of Rivulus giarettai, and discuss some biotic and abiotic variables related to its abundance in Free Flowing Waters (FFW) and Dam Reservoirs (DR) in palm grove (Mauritia flexuosa) marshes (Veredas) in Uberlandia, Minas Gerais, southeastern Brazil. The mean density (individuals/plot) of R. giarettai was about 13 times higher in FFW than in DR. In FFW, the density of R. giarettai was highest at intermediate amounts of substrate (plant mass) and it was positively rank-correlated with the depth, and the number of arthropods. Individuals occurred in an aggregated distribution. The aggregated pattern could be related to a concentration of individuals in microhabitats neither too much exposed nor completely saturated by plants. R. giarettai was relatively abundant and tolerant to slight man-made habitat modifications. Damming appeared to be especially problematic by negatively affecting its density.  相似文献   

7.
8.
This paper presents the results of a biostratigraphic analysis of pyritized diatom assemblages in the Saint-Josse core (CC82) located in the northern part of the Paris basin (coordinates: X =555?000, Y =307?324 and Z =56.9 m). During the Paleocene-Eocene this locality was situated in a small bight of the North Sea Basin. The results are obtained from sediments of the Thanet and Mont-Bernon group equivalents belonging to the Paleocene-Eocene interval. Thirteen samples were studied and eleven contain pyritized diatoms. By epigenesis, the siliceous frustule of the diatom is changed into a pyritized skeleton with all the ornamentation very well preserved such as the velum, the areolae, the labiate processes, etc. Dispersive X-Ray analyses show this complete replacement of silica by pyrite. Another form of pyritization is crystallization of pyrite (in cubes, pyritohedrons, octahedrons, framboids) in internal cavities of the diatoms to produce internal moulds, also called steinkerns, which preserve the external morphology of the diatoms and some details such as the girdle. Despite pyritization, diatoms can often be recognized at the species level; brackish and marine species were observed but no fresh water specimens were encountered. Pyrite is easily altered into iron oxides. In outcrops, pyritized diatoms can be obscured or destroyed by oxidation. We have chosen borehole samples for this study to avoid the affects of weathering. Deposits from the Sorrus Unit (of the Thanet Group) have low abundances of pyritized diatoms (3 to 25 specimens per sample). This unit contains allochtonous diatom assemblages comprising Actinoptychussenarius, Coscinodiscus morsianus var. morsianus, and Coscinodiscus morsianus var. moelleri. Sample 34.31-34.45 from this unit is particularly interesting. It contains three specimens of Paralia siberica var. laevis, which is typical of an estuarine or littoral paleoenvironment, and corresponds to the more continental deposit of the Sorrus Unit. Seven samples, taken in the Argile de Saint-Aubin Unit (from the Mont-Bernon Group), contain more than 200 pyritized diatoms and between 9 to 16 different species per sample. A brackish assemblage (Actinoptychus senarius, Coscinodiscus commutatus and Stellarima microtrias) and a marine assemblage (C. morsianus var. morsianus, Coscinodiscus var. moelleri, Fenestrella antiqua, Odontellaheibergii, Rhizosolenia sp. 1 and Trinacria regina) are observed. The brackish assemblage expands in the upper part of the Saint-Aubin Unit indicating more widespread brackish paleoenvironmental conditions. Pyritized diatoms are important fossil markers in the Paris basin mainly when siliceous fossils (silicoflagellates or radiolarians) and others microfossils (foraminifers and dinoflagellates) are very poor or absent. Two diatom assemblages have been identified in the Saint-Josse borehole. The first assemblage D1, comprising C. morsianus var. moelleri (high occurrence), C. morsianus (a few) and T. regina (rare), is recorded in the Sorrus, La Calotterie, Bois Gorguette, Le Goulet and lower Saint-Aubin Units. The second assemblage D2, characterized by great abundance of F. antiqua and decreasing numbers of C. morsianus species, is found in the upper part of the Saint-Aubin Unit. These diatom assemblages can be correlated with other biozonations established in the North Sea basin and based on nannoplankton and diatoms (King, 1983), diatoms (Mitlehner, 1996) and calcareous nannoplankton (Martini, 1971). F. antiqua and C. morsianus var. moelleri are the more important diatom species encountered. F. antiqua (previously named Coscinodiscus sp. 1, King, 1983) is the fossil marker used by King to define his NSP4 biozone. The base of NSP4 corresponds to the lowest occurrence of F. antiqua and the top is marked by the highest occurrence of this species. The Sorrus, La Calotterie, Bois Gorguette, Le Goulet and Saint-Aubin (“Sparnacian” stage) Units, the last one comprising F. antiqua (increasing to acme), correspond to the NSP4 zone of King (1983). The Mont-Hulin and Château de la Bruyère Units correspond probably to the NSP5 zone of King (1983). F. antiqua and C. morsianus var. moelleri were also used by Mitlehner (1996) to differentiate the NSP4a zone (low abundance of F. antiqua and abundance of C. morsianus var. moelleri) from the NSP4b zone (great abundance and acme of F. antiqua). The abundance of C. morsianus var. moelleri is recorded in the lower part of Saint-Aubin Unit and the abundance of F. antiqua (high peak at 46% in the sample 17.87) is found in the upper part of Saint-Aubin Unit. Therefore, Sorrus, La Calotterie, Bois Gorguette, Le Goulet and the lower part of Saint-Aubin Units are correlated with the NSP4a zone and the upper part of Saint-Aubin Unit with the NSP4b zone. By correlating the calcareous nannoplankton biozonation (NP) of Martini (1971) with the biozonation of King (1983), adapted by Mitlehner (1996), the boundary between the NP9 and NP10 zones could be located in the 18.75-17.87 interval and the NP10-NP11 boundary at the top of Saint-Aubin Unit. Lithostratigraphic correlations between the units of the Saint-Josse borehole (Paris basin) and the formations of the North Sea basin can be established. The great abundance of C. morsianus var. moelleri and the great abundance (including acme) of F. antiqua are respectively recorded in the Sele and Balder Formations. Therefore, the interval Sorrus/lower Saint-Aubin Units is correlated with the Sele Formation and upper part of Saint-Aubin Unit with the Balder Formation.  相似文献   

9.
In vitro regeneration of black nightshade (Solanum nigrum L.) plants was achieved through callus-mediated shoot organogenesis followed by 30 d indoor ex vitro adaptation to nutritional stress under environmental ambience and thereafter 6-d outdoor acclimatization in pots prior to field establishment. Relevant physiological parameters including pigment content, chlorophyll a fluorescence, net photosynthetic rate (P N), transpiration rate (E), and stomatal conductance (g s) of in vitro-regenerated plants were investigated during the course of ex vitro adaptation. During the first 4 d of indoor transplantation to potting substrate, there was a marginal reduction in the leaf chlorophyll and carotenoid contents but P N and E were strongly reduced. The stomatal conductance and E/P N ratio were significantly higher in plants up to 20 d of indoor adaptation than those of comparable age grown naturally from seeds. The shape of the OJIP fluorescence transient varied significantly with acclimatization, and the maximum change was observed at 2.0 ms. The 2.0 ms variable fluorescence (V j), 30 ms relative fluorescence (M 0), photon trapping probability (TR0/Abs), and photosystem II (PSII) trapping rate (TR0/RC) showed initial disturbance and subsequent stabilization during 30 d of indoor acclimatization. Energy dissipation (DI0/RC) and electron transport probability (ET0/TR0) showed an initial phase of increase during the 4 d after plants were transplanted outdoors. During the 6-d outdoor acclimatization after transfer of plants to soil, no significant change in total chlorophylls and carotenoids, E, and g s were observed, but P N improved after reduction on the first d. The OJIP-derived parameters experienced change on the first d but were stabilized quickly thereafter. There was no significant difference between outdoor acclimatized plants and those of the seed-grown plants of comparable age with respect to photosynthetic and fluorescence parameters. Direct transfer of plants without indoor acclimatization, however, showed a completely different trend with respect to P N, E, and OJIP fluorescence transients. The bearing of this study on optimizing micropropagation is discussed.  相似文献   

10.
The restitution of the megalith’s technical manufacture, whith their assemblies lines and their sequences, enlarges the coast of the sens incluse in each Corsican monoliths. From the megalithics sites of Poghjaredda of Monte Rotondu (Sotta), Ciutulaghja (Appietu), and Presa (Altaghjè), some specifics activities area (pastoralism for example) or activities structured in the space (villages and tombs of middle Neolithic) interest this study. The contributions of many sciences permit to give an economic and social dimension to the choice of megalithics sites. Then, those choices are an aspect of the Neolithic process in Corsica, making part of sculpture and architecture. This study is conclued by a consideration on the actual worked stones’ terminology.  相似文献   

11.
We have been attempting for some time to discover a compound evidencing antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The dieckol isolated from Ecklonia stolonifera has been shown to exhibit antibacterial activity against methicillin-susceptible S. aureus (MSSA) and MRSA. The minimum inhibitory concentrations (MICs) of dieckol were determined in a range of 32 to 64 μg/mL against standard MSSA and MRSA strains. Furthermore, dieckol clearly reversed the high-level ampicillin and penicillin resistance of MRSA. The MICs of ampicillin against two standard strains of MRSA were dramatically reduced from 512 to 0.5 μg/mL in combination with 1/4 MIC of dieckol (16 μg/mL). The fractional inhibitory concentration (FIC) indices of ampicillin and penicillin were measured from 0.066 to 0.266 in combination with 8 or 16 μg/mL of dieckol against all tested MRSA strains, thereby suggesting that dieckol-ampicillin or dieckol-penicillin combinations exert a synergistic effect against MRSA. The results of this study indicate that dieckol, administered in combination with β-lactams, may prove effective in the treatment of MRSA infections. Our finding may also contribute to the development of an alternative phytotherapeutic anti-MRSA agent.  相似文献   

12.
《Acta Oecologica》2006,29(2):155-164
We studied three species of columnar cacti in the genus Neobuxbaumia which differ in their degree of rarity: Neobuxbaumia macrocephala (the rarest), Neobuxbaumia tetetzo (intermediate), and Neobuxbaumia mezcalaensis (the most common). To investigate the ecological factors that limit their distribution and abundance, we surveyed 80 localities within the region of Tehuacan-Cuicatlán, in Central Mexico. At each locality we measured several environmental variables, and the density of the Neobuxbaumia populations present. We used a principal component analysis (PCA) to identify the factors that are associated to the presence/absence of each species. Additionally, we carried out multiple regressions between environmental variables and population density to test whether the variation in these variables was related to changes in abundance. The results show that factors significantly affecting the distribution of these species are mean annual temperature, altitude, rainfall, and soil properties such as texture and organic matter content. N. mezcalaensis reaches maximum population densities of 14,740 plants per ha (average density = 3943 plants per ha) and is associated with localities with relatively abundant rainfall. N. tetetzo shows maximum population densities of 14,060 plants per ha (average = 3070 plants per ha), and is associated with sites located at high latitudes and with high phosphorous content in the soil. The rarest species, N. macrocephala, shows maximum densities of 1180 plants per ha (average = 607 plants per ha) and is associated with localities with high soil calcium content. The distribution of this species is limited to sites with specific values of the environmental variables recorded, conferring it a high habitat specificity which accounts for its rarity.  相似文献   

13.
The life cycle and developmental stages of Aylax hypecoi (Trotter, 1913, Hymenoptera: Cynipidae: Aylacini) were studied in detail. Aylax hypecoi is known to induce galls in fruits of two Hypecoum species — H. imberbe and H. geslini (Papaveraceae) and the larva develops in host plant fruits. The morphology and development of egg, larva and pupa were investigated, which has previously not been done. The shape and size of terminal-instar larvae and associated galls are sex-specific. Overwintering stage, adult emergence and flying periods, and egg productivity were studied also.  相似文献   

14.
Photosynthetic rate (P N), SPAD value, specific leaf area (SLA), flag leaf area (FLA), and nitrogen content (LN) of genus Oryza were investigated and their correlation was analyzed to assess some of the main photosynthetic traits among different species in the genus Oryza. The results revealed wide variation in these traits. The species O. rufipogon and O. australiensis exhibited maximum photosynthetic rate. Comparison of different types of genomes (diploid: 2n=2x=24; tetraploid: 2n=4x=48) and growth habit (shade- or sun-grown) showed the species of diploid (with genome symbol EE; 2n=2x=24) genomes, with perennial and sun-grown species, had high apparent photosynthesis compared to others. The species with BB/BBCC, shade-grown and the tetraploids showed high SPAD value, and the flag leaf in sun-grown species and diploids were thicker (low SLA) compared with others. However, no significant difference could be noticed among the different types of genomes. Higher leaf area was noticed among the species of CC/CCDD genome, perennial shade-grown species and tetraploids than in others. The variety IR 36 exhibited highest leaf nitrogen concentration. Correlation analysis showed a strong relationship between P N and leaf nitrogen concentration while no marked relationships were observed among other characteristics. It implies that the species with thick and small leaves with high nitrogen concentration and high photosynthesis evolved better than others. O. rufipogon, with the same genome as O. sativa, could be one of the wild rice resources for elite crop improvement.  相似文献   

15.
The medicinal plant, Nothapodytes foetida, contains a number of important alkaloids like camptothecin (an anticancer drug molecule), but its concentration is less to meet the existing demand of this important molecule, in an effort for accessible availability of camptothecin. An endophyte (designated ZP5SE) was isolated from the seed of Nothapodytes foetida and was examined as a potential source of anticancer drug lead compound, i.e., camptothecin, when grown in Sabouraud liquid culture media under shake flask conditions. The presence of an anticancer compound (camptothecin) in this fungus was confirmed by chromatographic and spectroscopic methods in comparison with authentic camptothecin. Isolated endophyte (Neurospora crassa) producing camptothecin may become an easily accessible source for the production of a precursor anticancer drug molecule in the future at a large scale. Published in Russian in Prikladnaya Biokhimiya i Mikrobiologiya, 2008, Vol. 44, No. 2, pp. 225–231. The text was submitted by the authors in English.  相似文献   

16.
The effect of p-nitrophenol (PNP) concentration with or without glucose and yeast extract on the growth and biodegradative capacity of Ralstonia eutropha was examined. The chemical constituents of the culture medium were modeled using a response surface methodology. The experiments were performed according to the central composite design arrangement considering PNP, glucose and yeast extract as the selected variables whose influences on the degradation was evaluated (shaking in reciprocal mode, temperature of 30°C, pH 7 and test time of about 9 h). Quadratic polynomial regression equations were used to quantitatively explain variations between and within the models (responses: the biodegradation capacity and the biomass formation). The coefficient of determination was high (R adjusted2 = 0.9783), indicating the constructed polynomial model for PNP biodegradative capacity explains the variation between the regressors fairly well. A PNP removal efficiency of 74.5% occurred within 9 h (15 mg/L as the initial concentration of PNP with use of yeast extract at 0.5 g/L).  相似文献   

17.
The author illustrates, in a very synthetical way, Aurignacian and early Gravettian lithic industry from Paglicci Cave (Mount Gargano, South Italy), found during excavations carried out by University of Siena in the Eighties-Nineties. Layer 24 contains Aurignacian industries and is constituted by a fine silty-sandy sediment. The faunal remains from layer 24, dominated by Equus asinus, indicate a dry-temperate phase which on the basis of 14C dates, would be identified with the Arcy. Lithic industry contains numerous marginally backed bladelets and microbladelets Dufour like that, in the higher level evolve into a special type (denominated “PA 24 A1”). The early Gravettian occupies the overlying layers 23 and 22 that are rich in rough stones and blocks and contain more or less cold faunal remains (at first dominated by Capra ibex, subsequently Bos primigenius becomes abundant): the 14C dating insert them in a phase between Arcy and Tursac. Lithic industry includes a great number of La Gravette backed points and especially microgravette backed points. Some probable fléchettes are also present but unfortunately they are fragmented.  相似文献   

18.
The activity of enzymes characteristic for C4-type photosynthesis was determined in different organs of two herbaceous plants: Reynoutria japonica Houtt. and Helianthus tuberosus L. The activity of phosphoenolpyruvate carboxylase (PEPC) was usually higher in the roots, some of the stem tissues and petioles in comparison to the leaf blades. The highest activity of malic enzymes (NAD-ME, NADP-ME) and phosphoenolpyruvate carboxykinase (PEPCK) was in the petioles and stem tissues of both plants and the lowest in the leaf blades and the pith of Helianthus tuberosus L.  相似文献   

19.
The presence and distribution of NO and H2S-synthesizing elements in the thoracic ganglion in two crab species, Eriocheir japonicus and Pugettia quadridens, are shown using the staining methods of NADPH-diaphorase histochemistry and cystathionine-β-synthase (CBS) immunohistochemistry. NO and H2S have been established to be synthesized by different neurons in the thoracic ganglion. The high CBS activity in efferent elements (segmental motoneurons, interneurons and nerve fibers in the limb neuropil) indicates the involvement of hydrogen sulfide in the organization of locomotor behavior in crustaceans. The presence of H2S-synthesizing neurons in the wall of the sternal artery in E. japonicus allows suggesting the participation of H2S in the regulation of vascular tone.  相似文献   

20.
The fossiliferous levels of Caune de l'Arago supply a useful tool to investigate the relationships between faunal renewals and climate changes in a restricted area during the Middle Pleistocene. On the other hand the Italian fossil assemblages of the middle Galerian testified changes of palaeoenvironmental conditions. A biochronologic and palaeoecologic comparison among large mammalian faunas of these quite different Mediterranean regions have been performed in the aim to value possible vicariance of taxa and differences of faunal renewal dynamic during the Middle Pleistocene. After the results of our analysis we can correlate the faunal assemblages from the “Complexe moyen, ensemble stratigraphique I”, “Complexe moyen, ensembles stratigraphiques II and III”, “Complexe supérieur, sols A and B” of Caune de L'Arago sedimentary succession with the Italian Isernia (middle Galerian), Fontana Ranuccio (late Galerian) and Torre in Pietra (early Aurelian) faunal units (FUs) respectively. The French faunal assemblages were characterised by the absence of browsers and, conversely, by the presence of boreal taxa, mainly grazers, that were rare or never occurred in Italy. Accordingly, at no one Italian faunal complex, as expected, we can find any indication of continental cold climatic condition as showed by the faunal complexes of the Caune de l'Arago. Nevertheless, the major climate changes characterising the Middle Pleistocene can be detected in both regions. During the span time of Isernia FU, the temperature was at its lowest and arid conditions prevailed, whereas during the following Fontana Ranuccio FU humidity and temperature increased, as is more evident in central Italy local faunas. Moreover, after the similarity analysis, the Visogliano local fauna (North-Eastern Italy) was more related to the French than to the Italian ones. During the late Middle Pleistocene (Torre in Pietra FU) a moderate faunal reconstruction can be detected in both regions. The renewal was linked to climatic modifications taking place in the Mediterranean area approximately around OIS 11/OIS 10 transition, when interstadials became progressively milder and average humidity increased.  相似文献   

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