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1.
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   

2.
Li  Chunlin  Cai  Qianqian  Luo  Youlong 《Cluster computing》2022,25(2):1421-1439

Improper data replacement and inappropriate selection of job scheduling policy are important reasons for the degradation of Spark system operation speed, which directly causes the performance degradation of Spark parallel computing. In this paper, we analyze the existing caching mechanism of Spark and find that there is still more room for optimization of the existing caching policy. For the task structure analysis, the key information of Spark tasks is taken out to obtain the data and memory usage during the task runtime, and based on this, an RDD weight calculation method is proposed, which integrates various factors affecting the RDD usage and establishes an RDD weight model. Based on this model, a minimum weight replacement algorithm based on RDD structure analyzing is proposed. The algorithm ensure that the relatively more valuable data in the data replacement process can be cached into memory. In addition, the default job scheduling algorithm of the Spark framework considers a single factor, which cannot form effective scheduling for jobs and causes a waste of cluster resources. In this paper, an adaptive job scheduling policy based on job classification is proposed to solve the above problem. The policy can classify job types and schedule resources more effectively for different types of jobs. The experimental results show that the proposed dynamic data replacement algorithm effectively improves Spark's memory utilization. The proposed job classification-based adaptive job scheduling algorithm effectively improves the system resource utilization and shortens the job completion time.

  相似文献   

3.
Small heat shock proteins (sHSPs) act as molecular chaperones and are widely distributed in all kinds of organisms. Comparative analysis revealed that an orthologous shsp was present during insect evolution. Here, hsp21.8b, one insect orthologous shsp, had been identified in Tribolium castaneum. Quantitative real‐time PCR illustrated that Tchsp21.8b was expressed in all developmental stages, along with the lowest expression at early embryonic stage and relative high expression at other stages especially in late eggs and late pupae. In the adult period, Tchsp21.8b exhibited the highest expression level in central nervous system and followed in elytron, epidermis, ovary and fat body. Moreover, it was upregulated 3.39‐fold in response to enhanced heat stress (45°C) for 4 hr but not to cold stress (4°C) and was upregulated by 1.73‐ to 1.94‐fold under ultraviolet (UV) exposure during 4–6 hr. It was also downregulated by 20.8%–41.8% under starvation in 3 days and had a “down‐up‐down” trend under the pathogen stresses. Larval RNA interference of Tchsp21.8b caused 40.6% insects mortality and reduced the oviposition amount by 66.0% and only 21.0% of the ds‐Tchsp21.8b eggs could hatch into larvae. These results suggested that as an orthologous shsp, Tchsp21.8b not only plays important roles in the growth, development and fecundity of T. castaneum but with the competence to resist the environment stresses, although the response is relatively weak compared to other hsps. Results from this study also uncovered the functions of the orthologous shsp in the development and anti‐stresses ability of T. castanuem. It provided more scientific evidence for revealing the physiological mechanisms of shsps of the insects and enhanced the capabilities to control different pests.  相似文献   

4.
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   

5.

Objective

To investigate the accuracy in the estimation of the aortic lumen area and distensibility obtained from Steady-State Free-Precession (SSFP) and Phase Contrast (PC) MR sequences.

Subjects and methods

Systolic and diastolic aortic lumen of the ascending and descending aorta of 50 subjects, collected with both acquisition sequences, were extracted using a 2D + t automated segmentation method.

Results

While the statistical study indicated very similar lumen areas for SSFP and PC data (slope = 1, r = 0.99), the corresponding distensibility values were less correlated (r = 0.54). Comparison between distensibility values in the ascending and descending aorta and study of these values with aging indicated a greater coherence with expected physiological behavior of the aorta when using SSFP images.

Discussion

Flow artifacts were more severe in PC images and could explain the better results obtained when using SSFP sequences.

Conclusion

A more accurate local assessment of the aortic stiffness is obtained from SSFP image sequences than from PC image sequences.  相似文献   

6.
This paper provides an overview of current knowledge of Plio Pleistocene Carnivora from Africa and Europe. In Plio Pleistocene times, many genera extend their ranges in Africa and Eurasia but their evolution are quite distinct in the two continents. In Africa, the modern carnivoran guild of sub saharian Africa originated in the early Pleistocene when took place extinction of archaic species. The north African fossil record is far from complete until the middle Pleistocene. In the middle and late Pleistocene, the modern carnivoran guild is associated with other elements: the simian jackal Canis simensis and two species of ursids Ursus arctos and Ursus deningeri which evolved towards Ursus spelaeus. Western European carnivore faunas show due to migration a constant turn-over of the species. Among felids, Panthera schaubi described by Viret (1954) and attributed to the genus Puma by Hemmer et al. (2004), is morphologically close to the snow leopard Panthera (Uncia) uncia. Canis etruscus is the sister group pf the clade including wolf and coyote and Canis arnensis is close to the African jackals. Ursus deningeri appears in the early Pleistocene together with two arctoid forms Ursus rodei and Ursus dolinensis that may be synonymous to Ursus arctos. The genus Hyaena is present in Europe in the middle and late Pleistocene.  相似文献   

7.
The Grosse Badlhöhle (Austria, Steiermark) is the origin of one of the most perfect bone points of the early Aurignacian and one of the best perforated femurs of the same period, which can be regarded as musical instruments. Two other fragments of points raise intriguing questions on the first Homo sapiens sapiens which cannot be solved today but will contribute to future research. A review on the debate of Palaeolithic flutes will follow with experimental proofs of boring artificial holes with high quality pictures on the blow-hole and the lack of gnawing traces on the opposite face. The musical possibility of an instrument with only one hole is discussed with ethnographic analogies. Hafting, optimal conditions of strength and possible use of arrows will close the discussion on the Badlhöhle bone artefacts.  相似文献   

8.
Neural tissue is derived from three precursor regions: neural plate, neural crest, and preplacodal ectoderm. These regions are determined by morphogen-mediated signaling. Morphogen distribution is generally regulated by binding to an extracellular matrix component, heparan sulfate (HS) proteoglycan. HS is modified by many enzymes, such as N-deacetyl sulfotransferase 1 (Ndst1), which is highly expressed in early development. However, functions of HS modifications in ectodermal patterning are largely unknown. In this study, we analyzed the role of Ndst1 using Xenopus embryos. We found that ndst1 was expressed in anterior neural plate and the trigeminal region at the neurula stage. ndst1 overexpression expanded the neural crest (NC) region, whereas translational inhibition reduced not only the trigeminal region, but also the adjacent NC region, especially the anterior part. At a later stage, ndst1 knocked-down embryos showed defects in cranial ganglion formation. We also found that Ndst1 activates Wnt signaling pathway at the neurula stage. Taken together, our results suggest that N-sulfonated HS accumulates Wnt ligand and activates Wnt signaling in ndst1-expressing cells, but that it inhibits signaling in non-ndst1-expressing cells, leading to proper neuroectodermal patterning.  相似文献   

9.
The “Grappin” or “Saint-Vincent's” cave, on the western slope of Jura, East of France, has been explored since 1889. From then to 1960, it has yielded substantial material dated to middle “à navettes” Magdalenian developing during the late Pleniglacial. The study of this settlement, although often mentioned, was never dealt with comprehensively until now. Due to its scientific importance for the middle Magdalenian of western Europe, the site is to be reinvestigated through a global interdisciplinary project entitled “The Tardiglacial and the start of Holocene in the Jura and its margins”. This paper will review our present knowledge of the site, radiocarbon dates and archaeological data. It also focuses on ornaments and engraved mobile art.  相似文献   

10.
New methods are described for accurate measurement of multiple residual dipolar couplings in nucleic acid bases. The methods use TROSY-type pulse sequences for optimizing resolution and sensitivity, and rely on the E.COSY principle to measure the relatively small two-bond 2DCH couplings at high precision. Measurements are demonstrated for a 24-nt stem-loop RNA sequence, uniformly enriched in 13C, and aligned in Pf1. The recently described pseudo-3D method is used to provide homonuclear 1H-1H decoupling, which minimizes cross-correlation effects and optimizes resolution. Up to seven 1H-13C and 13C-13C couplings are measured for pyrimidines (U and C), including 1DC5H5, 1DC6H6, 2DC5H6, 2DC6H5, 1DC5C4, 1DC5C6, and 2DC4H5. For adenine, four base couplings (1DC2H2, 1DC8H8, 1DC4C5, and 1DC5C6) are readily measured whereas for guanine only three couplings are accessible at high relative accuracy (1DC8H8, 1DC4C5, and 1DC5C6). Only three dipolar couplings are linearly independent in planar structures such as nucleic acid bases, permitting cross validation of the data and evaluation of their accuracies. For the vast majority of dipolar couplings, the error is found to be less than ±3% of their possible range, indicating that the measurement accuracy is not limiting when using these couplings as restraints in structure calculations. Reported isotropic values of the one- and two-bond J couplings cluster very tightly for each type of nucleotide.  相似文献   

11.
Since the middle of 1970s, one rock-shelter, six caves and one open archaeological site have yielded several hominid fossils. Among them, fossils from Yonggok, Mandal, Sangsi and Hungsu cave sites are useful to reconstruct the general shape of the Upper Pleistocene Hominids in Korea. The main study of this paper is to focus on the reconstruction of the general shape of the upper Pleistocene hominids, and to examine the cause of cranial changes from the late upper Paleolithic to Mesolithic period in Korea. Biomechanical principles are also applied to reconstruct the social activity of the upper Paleolithic man in Korea. In addition, it is assumed that main proponent of Paleolithic cultures in Korea might be Homo sapiens rather than any other species. Based on the anatomical characteristics of skull, the axillary border of the scapular and the midshaft of the femur, general appearance of Homo sapiens during the Pleistocene in Korea could be reconstructed.  相似文献   

12.
Rhodopseudomonas palustris TN1 was isolated from Songkhla Lake, Thailand. It phototrophically generates H2 from the predominant volatile fatty acids (VFAs) produced from microbial dark-fermentations of palm oil milling effluent; yields from 20 mM butyrate, acetate and propionate were 4.7, 2.5, and 1.7 mol H2 mol VFA−1 with light efficiencies of 1.8, 1, and 0.2%, respectively. Optimum conditions were pH 7 and 3000 lux, although production was reduced by only 33% at 1000 lux. CO2 evolution never exceeded 9 mmol mol VFA−1.  相似文献   

13.
The painting matter of the “back to back bison's panel” of Lascaux was examined and analysed by electron microscopy in order to understand the know-how of Magdalenian artists. The observation of several samples coming from specific areas of the two bisons give an access to the nature of the used pigments, to the preparation mode used to obtain various colours and also to the application mode. Thanks to this physicochemical approach, we can make hypotheses about the mind and the gestures of the artists.  相似文献   

14.
The Laacher See volcano erupted at 10,966 cal BC covered the whole Central Rhineland with huge tephra layers which are exploited now for some 150 years. During the last 15 years of research several new find locations exhibiting tree trunks of the hemi-boreal woodland, leaf imprints and animal tracks preserved in pumice and ashes reveal detailed insights into the (younger) Allerød environment. Five final Paleolithic (Federmessergruppen) habitation sites without any evident settlement structures but providing exogenous raw materials from outcrops in distances up to 170 km demonstrate the highly mobile mode of life of these hunter-gatherers groups some 13,000 years ago.  相似文献   

15.
Survey of seven strains determined as Septonema ochraceum (Dothideomycetes, inc. sed.) isolated from pine litter or obtained from public collections revealed three new species, Fusicladium cordae, F. sicilianum (Venturiaceae), Cladophialophora matsushimae (Herpotrichiellaceae) and a cryptic species morphologically identical to Devriesia americana (Teratosphaeriaceae), but phylogenetically distinct. Morphological survey and phylogenetic analysis using nucleotide sequence data from the nuclear ribosomal subunit genes indicate a close relationship within three species colonising pine litter needles, F. cordae, F. pini and F. ramoconidii. F. sicilianum is most related to F. rhodense. C. matsushimae represents a species belonging to one of the lineages of the polyphyletic genus Cladophialophora. None of the strains observed can be classified morphologically as S. ochraceum, of which the type material does not exist.  相似文献   

16.
In a previous note we presented the expression of the late paleolithic spirituality (Welté and Lambert, 2004). A special analytic grid was used as a possible tool for a demonstration. We separeted rationality from metaphysic; notions which are linked with dialectic relations between necessity (daily constraints), thought, action and evolution in the paleolithic period. Starting from the no direct material activities like burials, funeral materials and art, we purpose now that such notions existed before the upper Paleolithic. We infer that a privilegious set of interactions between the animal and the human appeared early in the thought of the people, before the upper Paleolithic. A metaphysic univers forced itself upon them as an evident “anti-world” which is the symmetric shape of the real and tangible world. In such a context, the social system(s) could not discard these duality.  相似文献   

17.
Thirty-four species of ostracodes are collected in the platform series of the Southern Corbières; two biostratigraphical assemblages, with 13 and 29 species, are respectively recognized in Cenomanian and Upper Turonian; palaeoecology is specified. At that time, the ostracode sub-province of South-West France, established on Southern Corbières, Aquitaine, Touraine-Poitou-Charentes region and Provence, is connected with Eastern and Northern regions and countries: Sub-alpines ranges, Paris Basin, Great Britain, Switzerland and Bohemia, and with the Iberian Peninsula, sub-province of North-Central Spain and Western Portuguese Basin. The crossing of the Tethys and the Atlantic Ocean is realized, in Turonian, by some rare species.  相似文献   

18.
To overexpress the chitosanase gene (csn) in F. solani, a vector based on pCAMBIA 1300 was constructed. The csn gene, which is under control of the Aspergillus nidulans gpdA promoter and A. nidulans trpC terminator, was introduced back into the F. solani genome by Agrobacterium tumefaciens-mediated transformation, and the herbicide-resistance gene bar from Streptomyces hygroscopicus was used as the selection marker. Transformants which showed a significant increase in chitosanase production (~2.1-fold than control) were obtained. Southern blot analysis indicated that most transformants had a single-copy T-DNA integration.  相似文献   

19.
Corals from the Barremian of southern France (dépt. Ardèche and Drôme) are described. The rather small fauna of colonial corals encompasses 23 species belonging to 18 genera of both Hexa- and Octocorals. The assemblages from the lower as well as upper Barremian show stratigraphic relationships to those of the Hauterivian and Aptian of the Tethys and the Caribbean province.  相似文献   

20.
The human remains recovered from “Grotte supérieure de Zhoukoudian” are the best-preserved Late Pleistocene human fossils in East Asia. For decades, as the representative of the Late Pleistocene human in East Asia, the Upper Cave skulls have been playing important role in the research of origins of modern Mongoloids and American Indians. With the advance of the origin and evolution of modern humans, more attention has been paid to the details and the mechanisms for the late Pleistocene human evolution and the formation of modern human populations. Both the origin and diversification of modern humans have been stressed. Some studies further trigger the debaters on the Upper Cave Man concerning its evolutionary level and its role in the formation of modern human populations in East Asia. To further explore these problems, we examined and compared 12 non-metric features on the 3 Late Pleistocene Upper Cave skulls and 162 Holocene individuals earthed from two archaeological sites of North China (Longxian and Yanqing). Our results indicate that 8 on the 12 features have different expression patterns between Upper Cave Man and recent Chinese leading the authors to believe that more primitive expressions appeared on the Upper Cave Man than on recent Chinese populations. Based on these findings, some problems on the intragroup variation in Late Pleistocene and Holocene populations are discussed.  相似文献   

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