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1.
《L'Anthropologie》2019,123(2):216-232
In 2004–2006 a group of Lower Palaeolithic sites was discovered in the northeastern Caucasus: Ainikab I–VI, Gegalashur I–III and Muhkai I–II. Since then, they have been the subject of comprehensive scientific investigations. One site which is undergoing active research is the multilayered site of Muhkai II. Multiple cultural layers at the site have been found in a 73 m thick sequence of Early Pleistocene sediments. The geological age of the layers encompasses the interval 2.1–0.8 million years ago, or the majority of the Early Pleistocene. Layer 80 of Muhkai II is located in the central part of the section at a depth of −33.6 to −34.0 m. Its significance lies in the fact that the site contains two cultural layers–the upper and the lower (main)–that are preserved in situ or have been subject to minimal fluvial processes. The finds consist of lithic artefacts and osseous faunal remains. According to field observations and microstratigraphic analyses, the cultural layers can be characterised as the ancient surfaces of an occupation area. Two stages of occupation can be defined in the lower cultural layer. Layer 80 of Muhkai II was a periodically visited location at the banks of a waterbody, where the acquisition and butchery of large mammals took place. The faunal collection contains 301 bones, deriving from four carnivorous and six herbivorous species of mammals. The total lithic collection contains 1094 finds. According to typological and technological criteria the lithic assemblage relates to the Oldowan and has analogies with Oldowan sites in Africa (particularly with sites of the Olduvai Gorge as well as others). At the same time, some specifics of the lithic assemblage reflect the uniqueness of the site and its functional type. Layer 80 of the Muhkai II site is estimated to date to within the chronological interval ∼2.1–1.7 mya. 相似文献
2.
《Comptes Rendus Palevol》2014,13(8):717-725
This article presents the results of excavations and multidisciplinary investigations of the extraordinary Oldowan site of Muhkai II in the northern Caucasus (Republic of Dagestan, Russia) from 2008 to 2012. Archaeological and palaeontological materials are summarized together with data from palaeomagnetic and palynological analyses, obtained from 34 cultural layers at the site. This gives an opportunity for a new approach to the question of the timing and route of the first human settlement of the middle latitudes of western Eurasian, including south-eastern Europe. Judging by the data obtained, this occurred around 2 million years BP and a route of migration was located along the western shore of the Caspian Sea. 相似文献
3.
Fossil plants are scarce in the Earliest Triassic marine deposits of western Guizhou and eastern Yunnan. Only Annularia shirakii, Lobatannularia sp., Paracalamites stenocostatus, Gigantopteris sp., Pecopteris sp. were reported from the base of the Kayitou Formation dated as Early Induan by marine fauna. Recently, we discovered numerous representatives of the genus Annalepis in the same Lowermost Triassic beds: A. latiloba, A. brevicystis, A. angusta, Annalepis spp. occur associated with a basal Triassic marine fauna. This discovery fills the biostratigraphic gap between the Late Permian “Gigantonoclea guizhouensis-Ullmannia cf. bronnii-Annularia pingloensis” and the late Lower Triassic “Neuropteridium–Albertia–Voltzia” assemblages reported from South China. It represents an important datum dealing with the very beginning of a new terrestrial flora installation after the Permian flora disappearance following the Permian–Triassic boundary mass extinction. This “starting point” of a new vegetal cover in South China is to be taken into account in reconstructing through space and time the settlement process of the Mesozoic floristic provinces. 相似文献
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5.
The Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is a destructive fruit pest in a wide range of cultivated fruit crops and wild plants. This species is a potentially highly invasive fruit fly to Jeju area of Korea. This study was conducted to evaluate the effect of host plants distributed temporally on the population development of B. dorsalis. The temperature-dependent bionomic data for a synonymous group of B. dorsalis, including B. philippinensis, B. papayae, and B. invadens were collected from previous publications and combined to construct a population model of this pest and its thermal constant. We developed a stage-transition model of eggs, larvae and pupae, and an oviposition model for basic population modeling of the four common strains. We investigated the abundance of the host plants of B. dorsalis in a selected site in Jeju and parameterized them in terms of temporal availability to incorporate into the population model. The contribution of host plants for the population growth of B. dorsalis in the selected site was different according to the group of host plants. For example, B. dorsalis populations largely decreased by 93%, when host plants belong to Moraceae (mainly Ficus sp.) were removed in the simulation. Also, we found that the host plants of Prunus persica, Ficus carica, P. mume, Eriobotrya japonica in this order contributed greatly to population abundance of B. dorsalis in the selected area, which was important in terms of mid-season host plants connecting the early adult population of B. dorsalis to citrus plants in the late season. Finally, we discussed a seasonal management strategy against B. dorsalis while considering the availability of host plants and the biology of this fruit fly in an invaded area. 相似文献
6.
The phenotypic consequences in the house mouse (Mus musculus domesticus) of the transition from an ordinary field-dwelling rodent to a species that is dependent on human populations was studied by investigating the morphometric variation of non-commensal populations of M. m. domesticus from Syria, Jordan, SW Iran, and Libya and comparing them with that of conspecific commensal populations from Eastern Turkey, Greece, and Bulgaria. Commensal populations of M. musculus musculus from the Czech Republic were used as an outgroup. About 849 adult specimens of M. musculus were analysed by multivariate procedures based on standard molar, skull and body measurements. As expected, there was considerable variation among the studied populations and a good correspondence between morphometric and geographic distances. The resulting morphometric tree was consistent with the hypothesis that the original radiation of M. m. domesticus took place somewhere in the Near East. Commensal populations of M. m. domesticus form a single derived branch. Specimens originating from four different sites in eastern Syria showed the greatest similarity to one another and possessed relatively bigger molars than the other studied populations. Commensal populations were characterised by longer tails when compared to non-commensal populations, which suggests an adaptation for living in a more three-dimensionally heterogeneous environment for commensal populations. 相似文献
7.
The pale grass blue butterfly, Zizeeria maha (Lepidoptera, Lycaenidae), has successfully been employed as an indicator species to evaluate acute biological changes in polluted human-living environments after the Fukushima nuclear accident. Here, we quantitatively examined the field sampling efficiency of the butterfly and its associated sexual sampling bias under different conditions, which may provide important information for environmental risk assessment. Sampling data were obtained in 2014 and 2015 from 87 localities across Japan. Across the localities, the mean capture rate was 17 individuals per hour per person, and males represented approximately 80% of the collected butterflies. No significant difference was detected in the capture rate under different weather conditions. Among the four habitats, the riverside showed a significantly higher capture rate than the city park. A shorter sampling time tended to yield a higher capture rate. Comparisons among prefectures and districts of collection localities revealed that the Kanto district had significantly higher percentages of collected males than 4 other districts. Fukushima prefecture also had high percentage, although not significant. A generalized linear mixed model indicated that the capture rate was significantly negatively affected by the agricultural village, the city park, the rainy weather, and latitude and positively by longitude. Together, the present study showed high sampling efficiency and versatility of this butterfly as an indicator for environmental risk assessment but simultaneously suggested preferable conditions for a field sampling design. This study also suggested a possibility that the Fukushima nuclear accident or other factors might have affected behavioral or population dynamics of the butterfly. 相似文献
8.
Fernand David 《Comptes rendus biologies》2010,333(5):424-428
Pollen analyses were undertaken on a small peat bog (Ecuelles 06° 49′ 41″E, 45° 58′ 49″N, 1855 m asl), located on the Anterne mountain (Upper-Arve Valley, French north-western Alps). The study highlights the role of green alder (Alnus alnobetula [Ehrh] K. Koch) in Holocene vegetation dynamics of the nowadays treeless subalpine belt. At this place, the onset of human perturbation caused a retreat of fir and arolla-pine stands and an expansion of green alder, which consequently dominated the landscape from 3700 up to 1965 cal. BP. After 1965 cal. BP, the clearings led to the present grasslands with few ligneous species (spruce, larch) on inaccessible cliffs or green alder on the edges of torrents or in avalanche corridors. Picea percentages have increased after 3900 cal. BP, but, due to human activities, spruce has never constituted large stands in the study area. The present general expansion of green alder is due to the decreasing human impact and it constitutes the first step of re-afforestation that should lead to mixed stands of spruce and arolla-pine. The study gives a new evidence of the past diversity of the vegetation cover and do not support the idea that green alder colonization at the subalpine belt constitutes a long-term risk for the vegetation diversity. 相似文献
9.
Shell beds consisting of concentrations of minimally transported, slightly damaged skeletal remains of indigenous organisms—comparable to bedded shelly accumulations of certain shallow-marine environments—have rarely been reported from truly deep-ocean turbidites. The general expectation is that shelly accumulations, when they do occur, ought to be derived from upslope sources and many kilometers away from the site of deposition. A Cretaceous thin-bedded turbidite in the Franciscan Complex of northern California, however, hosts a concentration of large specimens of the giant foraminiferan, Bathysiphon aaltoi, reflecting localized transportation and deposition in the original life habitat. The tests were derived from a densely populated thicket of the bathysiphonid probably located only a few metres/10s-of-metres away, decimated by a turbidity current that either overflowed an active submarine fan channel or spread outward from a suprafan lobe. As such, this unusual bathysiphonid-rich deposit can be viewed as a kind of deep-ocean level bottom ‘shell bed’. 相似文献
10.
The Middle East is at the southeastern borderline of the range of the subterranean amphipod Niphargus. The review of new and published data identified two new species and set the guidelines for the future research in the area. The genus in this part of the world seems to be insufficiently studied. The taxonomic status of Niphargus valachicus, population identified as N. spoeckeri and some populations, identified as N. nadarini, need to be reviewed. According to present data, we expect the highest diversity in Western Turkey. The eventual new records of the genus in the Middle East can be expected from those areas where even the longest periods of drought in the recent geological history did not affect the water supply. 相似文献
11.
Muhlhausler BS Gibson RA Makrides M 《Prostaglandins, leukotrienes, and essential fatty acids》2011,85(2):83-88
Dietary n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) reduce adipogenesis and lipogenesis in adult rodents, but it is not clear whether an increased n-3 LCPUFA supply during the perinatal period influences body fat mass in the offspring. This systematic review aimed to evaluate the existing evidence from animal studies, which have addressed this question. Medline was searched for relevant articles. Studies were included if they involved maternal n-3 PUFA or LCPUFA supplementation and measured fat mass in the offspring. The design and quality of each study was assessed. Only four animal studies met our inclusion criteria. Three studies reported a lower fat mass in offspring of n-3 LCPUFA supplemented dams, however only one of these studies confined the intervention to the perinatal period. The dose of n-3 PUFA, the nature of the control treatment, the approaches used and outcomes assessed differed between studies. This review highlights the paucity of robust animal data as to the effect of increased n-3 LCPUFA exposure during the perinatal period alone, on body fat mass in the offspring and calls for further studies. 相似文献
12.
Antonella Virgilio Luigi Petraccone Veronica Esposito Giuseppe Citarella Concetta Giancola Aldo Galeone 《Biochimica et Biophysica Acta (BBA)/General Subjects》2012
Background
The abasic sites represent one of the most frequent lesions of DNA and most of the events able to generate such modifications involve guanine bases. G-rich sequences are able to form quadruplex structures that have been proved to be involved in several important biological processes.Methods
In this paper, we report investigations, based on calorimetric, UV, CD and electrophoretic techniques, on 12 oligodeoxynucleotides analogues of the quadruplex forming human telomere sequence d[TA(G3T2A)3G3], in which each guanine has been replaced, one at a time, by an abasic site mimic.Results
Although all data show that the modified sequences preserve their ability to form quadruplex structures, the thermodynamic parameters clearly indicate that the presence of an abasic site decreases their thermal stability compared to the parent unmodified sequence, particularly if the replacement concerns one of the guanosines involved in the formation of the central G-tetrad.Conclusions
The collected data indicate that the effects of the presence of abasic site lesions in telomeric quadruplex structures are site-specific. The most dramatic consequences come out when this lesion involves a guanosine in the centre of a G-run.General significance
Abasic sites, by facilitating the G-quadruplex disruption, could favour the formation of the telomerase primer. Furthermore they could have implications in the pharmacological approach targeting telomere. 相似文献13.
The niches invaded by exotic species are generally not entirely vacant, and one possible factor affecting the success of the
invader to establish a permanent large population may be the ability of the former to outcompete native species. Eudiaptomus gracilis, which was not present in Italy before the 1980s, is becoming established in an increasing number of Northern Italian lakes,
ultimately replacing the endemic E. padanus. Coexistence of the two species in Lake Candia lasted only 7 months, suggesting that species replacement was determined either
by environmental changes or by strong competition. To assess whether the potential for interspecific competition existed and
to identify species' traits which could explain the competitive superiority of E. gracilis, we examined field seasonal patterns, reproductive parameters and body size of the two species. E. padanus abundance was probably reduced by predation and parasitism, which favoured the displacement of the species shortly after
invasion by E. gracilis. The temporarily underexploited niche provided an opportunity for the successful establishment of the invader. The reproductive
patterns of the two species were found to be similar in most of their features, with the exception of a markedly larger clutch
size and a smaller egg volume in the resident species. By contrast, the invader showed a higher adult:egg ratio and a lower
death rate. Thus, despite the greater fecundity of E. padanus, the competitive success of the invader might be attributable to interspecific differences in developmental rates and/or
juvenile mortality. 相似文献
14.
Qi Chen Yun‐dong Zhang Xiao‐hong Qi Yong‐wei Xu Yan‐hong Hou Zhi‐ye Fan Hai‐long Shen Di Liu Xing‐kai Shi Shi‐min Li Yun Duan Yu‐qing Wu 《Ecology and evolution》2019,9(21):12332-12338
Mythimna separata (Walker) moths captured in light traps were monitored in Luohe, central‐northern China, from 1980 to 2016. Annual average temperature recorded an increase of 0.298°C/10 years in this region in the period. Our results indicate that a rising April and May average temperature and earlier occurrences of days recording the highest day temperature (30°C) caused an advanced peak and increasing proportion of high ovarian development levels of first‐generation females in earlier summers. Results using Johnson's formulation of “oogenesis‐flight syndrome” indicate that increasing sexual maturity proportion has resulted in more emigrant individuals in the local first‐generation moth becoming residents, and then increased individuals rapidly in the local second‐generation moth since 2006. Consequences of this action have a boom in corn damage since 2007 in this region. Advanced peak dates of the first and second‐generation moth revealed the same response to increasing average monthly temperatures in the monitoring period. Increasing temperatures, the average May temperature exceeds or equal to 22°C, during the early 2000's may represent a physiological threshold for M. separata development. Our results suggest that climate warming may impact M. separata migratory status and cause a problem of crop production in this region. 相似文献
15.
The gene mutation for oral-facial digital syndrome type II (Mohr syndrome) is unknown. We describe a Saudi female infant with Mohr syndrome. An unclassified variant: c.2044 A>G, p.T682A in exon 12 of the GLI3 gene in a heterozygous state was identified in the infant. Mutation Taster (http://www.mutationtaster.org) considers this variant as “disease causing”. However, when the unaffected parents were tested, the father was found to have the same variant, also in a heterozygous state. Hence, the pathogenic role of this variant seems unlikely; although apparent non-penetrance remains a possibility. 相似文献
16.
Thomas Schmitt Stefan Lange Stefan Sonnenberger Bodo Dobner Bruno Demé Andreas Langner Reinhard H.H. Neubert 《生物化学与生物物理学报:生物膜》2019,1861(1):306-315
This study used neutron diffraction to investigate a ceramide-[NP] C24/[AP] C24 /[EOS]-br C30/cholesterol/lignoceric acid (0.6: 0.3: 0.1: 0.7: 1) based stratum corneum modelling system. By adding specifically deuterated ceramides-[NP]-D3, [AP]-D3, and [EOS]-br-D3, detailed information on the lamellar and the nanostructure of the system was obtained. For the short periodicity phase a natural-like lamellar repeat distance of 5.47?±?0.02?nm was observed, similar to the [NP]/[AP] base system without the [EOS]-br. Unlike in this system the ceramides here were slightly tilted, hinting towards a slightly less natural arrangement. Due to the deuteration it was possible to observe that the long ceramide chains were overlapping in the lamellar mid-plane. This is considered to be an important feature for the natural stratum corneum. Despite the presence of a ceramide [EOS] analogue – able to form a long phase arrangement – no distinct long periodicity phase was formed, despite a slightly higher than natural ω-acyl ceramide ratio of 10?mol%. The deuterated variant of this ceramide determined that the very long ceramide was integrated into the short periodicity phase, spanning multiple layers instead. The – compared to the base system – unchanged repeat distance highlights the stability of this structure. Furthermore, the localisation of the very long ceramide in the short periodicity phase indicates the possibility of a crosslinking effect and thus a multilayer stabilizing role for the ceramide [EOS]. It can be concluded, that additionally to the mere presence of ceramide-[EOS] more complex conditions have to be met in order to form this long phase. This has to be further investigated in the future. 相似文献