Late Pleistocene proboscidean ivory artifacts from the Hiscock site,NY

Here is described the corpus of proboscidean ivory artifacts – the fruit of 30 years excavating – within the Palaeo-American component at the Hiscock site, western New York State. Several types and varieties are newly recognized and unique for the North American archaeological record. They allow us to forge linkages between the Old and New Worlds.     

广西百色田东坡西岭旧石器时代遗址发掘简报

坡西岭遗址发掘共出土 2 4 4件石制品 ,其中石器 4 6件 ,类型分为砍砸器、手镐、刮削器 3种 ,制作简单、粗糙 ,极少经过细致加工。这与百色盆地其它旧石器时代遗址所发现的石器具有相似的特征。其年代为旧石器时代早期。     

Molecular sled sequences are common in mammalian proteins

Recent work revealed a new class of molecular machines called molecular sleds, which are small basic molecules that bind and slide along DNA with the ability to carry cargo along DNA. Here, we performed biochemical and single-molecule flow stretching assays to investigate the basis of sliding activity in molecular sleds. In particular, we identified the functional core of pVIc, the first molecular sled characterized; peptide functional groups that control sliding activity; and propose a model for the sliding activity of molecular sleds. We also observed widespread DNA binding and sliding activity among basic polypeptide sequences that implicate mammalian nuclear localization sequences and many cell penetrating peptides as molecular sleds. These basic protein motifs exhibit weak but physiologically relevant sequence-nonspecific DNA affinity. Our findings indicate that many mammalian proteins contain molecular sled sequences and suggest the possibility that substantial undiscovered sliding activity exists among nuclear mammalian proteins.     

许昌人遗址研究的新收获及展望

许昌人遗址位于河南省许昌市灵井镇,2005-2017年发掘,揭露面积500余平方米,2007、2014年在9号探方出土包括2颗"许昌人"头骨在内的5个古人类个体,大量的石制品和21种哺乳动物化石。头骨具有东亚古人类、欧洲尼安德特人和早期现代人的镶嵌特征,可能代表一种新型的古老型人类。石制品研究显示,石核类型多样,且以小型双锥形盘状石核为特色;小型工具类型分异明显、加工精细,显示出不同于旧石器时代早期遗址中的工具技术,而与西方旧石器时代中期遗址工具技术上的特点较为一致。此外,遗址出土7件软锤工具,以动物长骨或鹿角为原料,用以修理石质工具。软锤工具的发现,对于认识中国旧石器时代技术的发展有重要意义。通过对遗址形成过程的分析,"许昌人"生活时期的沉积环境经历了三个阶段:下部灰绿色滨湖相粉砂堆积所指示的水流动力相对较弱的沉积环境,中部综红色粉砂堆积所指示的水流动力相对较强的沉积环境,以及上部浅棕红色粉砂堆积所指示的相对冷湿、水动力仍然较强的沉积环境。尽管存在水动力强弱上的相对变化,但水动力总体上并不大,以低能量水流为主,文化遗物属于原地埋藏。今后将开展人类艺术行为能力、古人用软锤和压制法制作石器的技术、动物埋藏学和年代学等方面的深入研究。     

Effects of inter-pond distance on the breeding ecology of tungara frogs

Habitat and resource distributions can influence the movement and aggregation of individuals and thus have important effects on breeding behavior and ecology. Though amphibians have been model systems for the study of breeding behavior and sexual selection, most studies have examined breeding behavior within a single pond. As a result, little is known about how inter-pond distance affects breeding amphibians. We studied the effects of inter-pond distance on the breeding ecology of the tungara frog, Physalaemus pustulosus, in replicated pond arrays in which distance was varied from 0 to 50 m. We predicted that male site fidelity and male aggregation within arrays would increase with inter-pond distance, and that the opportunity for mate choice and oviposition site selectivity by females would decrease with the distance between ponds. Male site fidelity did increase with inter-pond distance. However, male aggregation decreased with distance, such that males tended to be more evenly spaced among ponds when ponds were farther apart. The opportunity for mate choice by females, measured as the number of males within the phonotactic radius of females, also decreased with inter-pond distance. Each of these three responses was consistent with a threshold effect between 5 m and 10 m in inter-pond distance. This threshold corresponded to the maximum distance at which females in laboratory choice experiments exhibited phonotaxis toward the ”whine” call of a tungara male, suggesting that phonotactic limits may play an important role in tungara movements and spacing patterns. The distribution of egg masses among ponds, a potential correlate of oviposition site selectivity, did not vary with inter-pond distance. Multiple egg masses deposited on the same night were significantly overdispersed in all distance treatments, implying that females may select oviposition sites to avoid conspecific egg masses over distances of at least 50 m. Collectively, these results demonstrate that inter-pond distance may indeed affect amphibian breeding and movement behavior, and that consideration of multiple habitat patches and their spatial distributions can provide new insights into even the most well-understood mating systems. Received: 9 January 1999 / Accepted: 1 August 1999     

A novel UV laser-induced visible blue radiation from protein crystals and aggregates: scattering artifacts or fluorescence transitions of peptide electrons delocalized through hydrogen bonding?

Proteins lacking prosthetic groups and/or cofactors are known to undergo electronic excitation transitions only upon exposure to UV-C (< 280 nm) and UV-B (280-320 nm), but not UV-A (320-400 nm) photons. Here, we report the discovery of a novel excitation that peaks at approximately 340 nm and yields visible violet-blue radiation with apparent band maxima at approximately 425, 445, 470, and 500 nm. All proteins and large polypeptides examined in solid form, and in solutions, display this quenchable and photobleachable radiation which can be established not owing to aromatic sidechains. As a note of caution, we wish to state that we have not been able to completely eliminate the possibility that the radiation may be an artifact owing to second order effects such as, e.g., Raman scattering of Raman-scattered photons; however, we assert that all our experiments indicate that the radiation actually owes to some form of fluorescence. We propose that peptide electrons that have been delocalized through intramolecular or intermolecular hydrogen bond formation display these long-wavelength electronic transitions. If confirmed by future studies, this preliminary discovery may turn out to have important implications for biomolecular spectroscopy, protein crystallography, and materials science.     

Importance of arginine residues in the determination of the biological activity of human corticosteroid-binding globulin

The binding activity of human corticosteroid-binding globulin (CBG) is pH dependent and governed in alkaline pH ranges by the pK of arginine. No essential arginine residues is located in the binding site. The loss of biological activity is rapid and complete as soon as one arginine residue is modified by phenylglyoxal. There is also a transconformation of the CBG molecule. Therefore the surprising stability of CBG up to pH 11.5 may be explained by a large dependence of the CBG tertiary structure on the integrity of one arginine residue : as long as the ionized state of this single residue is not changed (pH less than pK of the guanidyl group) the tertiary structure of the biologically active CBG is maintained in alkaline pH ranges.     

Unusual Methods of Antigen Transport

Two types of unusual transport mechanisms of antigens are described, one involving caterpillar hairs (setae) of gypsy moths, and the other involving grass pollen attracted to plastic sleds of an Alpine slide. Antigenic sources, investigations into peculiar mechanisms of spread, and impact of these antigens on allergic people are discussed. Each type affected allergic people in a different fashion, yet each type was associated with its own characteristically similar symptom complex. Natural factors terminated the gypsy moth antigen spread, but active interference into the Alpine slide antigen cycle was required for control.     

Waterbird herbivory on a newly created wetland complex: potential implications for site management and habitat creation

Estimations of waterbird herbivory at a newly created wetland, indicate that overwintering waterbirds have the potential to remove a large proportion of the above-ground macrophyte standing crop in the main lagoons. Observed lake state switching and changes in macrophyte species composition may have been linked, in part, to waterbird herbivory. Significant differences were observed in the distribution of certain species of waterbird between the lagoons, which may reflect food preferences. Between 30% and 50% of the herbivorous waterbird community utilised alternative on-site feeding areas over the winter period thus reducing the impact of grazing intensity in the larger open water areas. These results emphasise the advantages of incorporation of site heterogeneity, specifically distinct hydrological units, within the design of wetland creation schemes. Hypereutrophic conditions, with turbid water and dense filamentous algal blooms were experienced on the Reservoir Lagoon yet the lagoon supported high densities of overwintering birds (> 100 individuals ha^–1. This led to an alleviation of grazing pressure on other water bodies thereby promoting the development of macrophyte communities elsewhere on site. The need for work to provide a better understanding of critical thresholds of herbivory in determining community composition and abundance, and particularly the role of eutrophication in these processes is highlighted.     

The occurrence and preservation of ammonites in the Blue Lias Formation (lower Jurassic) of Devon and Dorset, England and their palaeoecological, sedimentological and diagenetic significance

More than two thirds of beds in the lowest Jurassic, Blue Lias Formation lack ammonites, which are commonly preserved in irregular or planar-bedded, bioturbated limestones, very rarely in laminated limestones and almost never in laminated black shales. Ammonites are preserved in 3D in nodular and planar-bedded limestones and at any orientation to bedding. Co-occurrence with macrobenthos and absence from beds without benthos suggest that Blue Lias ammonites were nektobenthonic. Scour structures and imbrication of ammonites in the Best Bed imply presence of traction currents. Lack of epifauna on large cephalopod shells (and other fossils) implies rapid deposition in event beds. Blue Lias deposition was episodic, not slow and continuous as the fine grain size implies. Undistorted trace fossils, uncrushed ammonites and stable isotope values all suggest early cementation of limestone beds from pore waters of a similar composition to contemporary Jurassic sea water. A clear diagenetic trend exists, with limestones having least, and laminated black shales most, modified stable isotope values. Contrast between trace fossil fills and host sediment demonstrates that Blue Lias rhythms are primary, but limestone beds have been diagenetically cemented.     

烟墩堡遗址研究

烟墩堡遗址位于三峡地区重庆市丰都县,地处长江干流的第四级阶地,出土1300余件石制品。遗址底部的似网纹红土层是石制品的原生层位;上部的粘土层和粉砂层是流水等从高处搬运、二次堆积形成的,除石制品外,还混入新石器时代的陶片。石制品应为一套文化组合,以磨圆度较高的河床砾石为原料,类型包括石锤、断块、碎屑、石核、石片和石器,以大型和中型者为主;石片占大多数;石器以刮削器和砍砸器为主,加工简单,属中国南方旧石器时代早期砾石石器工业。零台面石片的出现对“摔碰法”技术的起源提供了线索。     

Étude du site de Longgupo – Synthèse

If the hominids are of African origin, as data support, we can hypothesize that the date of the first population diffusion must be moved back to 2.5–2.6 mya, and that the first populations in central China were oriented toward new technological options, which are only found in Africa much later. In the present state of research, it appears that we should abandon our old paradigms, which have over time become “truths”, because instead of a unifying view–monolithic–of these periods, we advocate recognition of the existence of spatial and temporal cultural otherness.     

An objective approach to evaluating natural drainage of forest mineral soils for non-specialists

Soil drainage is a fundamental element of northern forest productivity. However, its evaluation is a complex operation involving numerous parameters, while no standard approach exists as yet. We have devised drainage evaluation grids based on topographical, edaphical and vegetational parameters. Since distinct surficial deposits influence the relationships between drainage classes and evaluation parameters in distinct patterns, different grids have been proposed for different textural groups.     

泥河湾盆地半山早更新世旧石器遗址初探

半山旧石器遗直位于河北省张家口市阳原县泥河湾盆地东端,埋藏在泥河湾层里。它与工不谷蛇早更新世旧石器遗址以一条正断层相隔。分别在断层的上盘和下盘。半山遗址的位置比东谷索遗址低７０余米,但根据野外观察,二者的地层层位大致相当。半山遗址发掘近２平方米,获得９５件石制品和一些动物化石。初步分析,半山的石制品和东谷索的非常相似,它们应该属于同时期的产物。     

Unusual commonality in active site structural features of substrate promiscuous and specialist enzymes

Enzyme promiscuity is the ability of (some) enzymes to perform alternate reactions or catalyze non-cognate substrate(s). The latter is referred to as substrate promiscuity, widely studied for its biotechnological applications and understanding enzyme evolution. Insights into the structural basis of substrate promiscuity would greatly benefit the design and engineering of enzymes. Previous studies on some enzymes have suggested that flexibility, hydrophobicity, and active site protonation state could play an important role in enzyme promiscuity. However, it is not known yet whether substrate promiscuous enzymes have distinctive structural characteristics compared to specialist enzymes, which are specific for a substrate. In pursuit to address this, we have systematically compared substrate/catalytic binding site structural features of substrate promiscuous with those of specialist enzymes. For this, we have carefully constructed dataset of substrate promiscuous and specialist enzymes. On careful analysis, surprisingly, we found that substrate promiscuous and specialist enzymes are similar in various binding/catalytic site structural features such as flexibility, surface area, hydrophobicity, depth, and secondary structures. Recent studies have also alluded that promiscuity is widespread among enzymes. Based on these observations, we propose that substrate promiscuity could be defined as a continuum feature that varies from narrow (specialist) to broad range of substrate preferences. Moreover, diversity of conformational states of an enzyme accessible for ligand binding may possibly regulate its substrate preferences.     

泥河湾盆地板井子旧石器时代遗址的形成过程

板井子遗址是泥河湾盆地晚更新世早期的一处重要遗址,光释光年代为距今8～9万年.本文以2015年出土的考古材料为研究对象,从地层的沉积环境、考古材料本体的埋藏特点两个角度,对板井子遗址的形成过程进行分析.分析表明,主文化层第5层为近原地埋藏类型,水流作用对小尺寸标本的保存及标本的空间集聚特征影响较大,但石制品技术类型组合...     

Relations between understorey vegetation,site productivity,and environmental factors in Pinus sylvestris L. stands in southern Finland

Relations between understorey vegetation, site productivity, and environmental factors in mature stands of Pinus sylvestris L. in southern Finland were studied using data from 234 sample plots. The (weighted) Pearson product-moment correlation between site index and the first ordination axis of detrended correspondence analysis (DCA) was 0.83. The correlation was clearly better where site index was above 21 m (r=0.83) than where it was less (r=0.33). Partial canonical correspondence analysis (CCA) indicated that the residual compositional variation, not related to site fertility as expressed by site index, can be partly ascribed to high moisture regime with poor drainage (paludification), soil deposit type, soil stoniness, and macroclimate, and in part to unexplained sources. The unique influence of canopy cover on the vegetation composition was non-significant (p<0.05) and that of stand age too small to be detected in the vegetation data. The results support Cajander's forest site type theory according to which there exists a dominant relationship between understorey vegetation and site productivity in boreal forest ecosystems. Cladonia sectio Cladonia lichens, exluding Cladonia uncialis, were treated collectively, and abbreviated as Cladonia spp. The most frequent of these species were C. gracilis, C. cornuta, C. fimbriata, C. deformis, C. cenotea, C. botrytes, C. crispata, C. pyxidata, C. cornuta, and C. furcata.     

Documentation of sites of intertidal blue mussel (Mytilus edulis L.) beds of the Lower Saxonian Wadden Sea, southern North Sea (as of 2003) and the role of their structure for spatfall settlement

Field surveys (dating back to 1950) and aerial photograph series (dating back to 1966) were evaluated to determine sites of intertidal blue mussel (Mytilus edulis) beds at the Wadden Sea coast of Lower Saxony. Maps were prepared indicating sites of blue mussel beds during the last decades. A table gives additional information on the presence (or absence) of blue mussel beds at each site at the time of large-scale surveys. Altogether 187 sites of M. edulis beds were recorded in the investigation area. In spring 1996, there were still only 19 sites where mussel beds still occurred, although at 51 sites residual mussel-bed structures were present, e.g. shell bases of former beds or protruding patches (which had been occupied by M. edulis before the beds vanished) and open spaces. At that time, the majority of the sites contained neither mussel beds nor mussel-bed structures. The analysis of recent data confirmed that mussel larvae have preferred to settle in sites of present mussel beds and sites with bases of former mussel beds. There was no preferential selection of one of these categories (settled beds vs. shell bases). On the other hand, the presence of mussel beds or mussel bed structures is not obligatory for settlement, because sites without those structures were also re-settled by the spatfall in 1996, even though on a smaller scale.     

Modulation of copper site properties by remote residues determines the stability of plastocyanins

The metal cofactor determines the thermal stability in cupredoxins, but how the redox state of copper modulates their melting points remains unknown. The metal coordination environment is highly conserved in cyanobacterial plastocyanins. However, the oxidised form is more stable than the reduced one in thermophilic Phormidium, but the opposite occurs in mesophilic Synechocystis. We have performed neutral amino-acid substitutions at loops of Phormidium plastocyanin far from the copper site. Notably, mutation P49G/G50P confers a redox-dependent thermal stability similar to that of the mesophilic plastocyanin. Moreover, X-ray absorption spectroscopy reveals that P49G/G50P mutation makes the electron density distribution at the oxidised copper site shift towards that of Synechocystis plastocyanin.     

Archaeological horizons and fluvial processes at the Lower Paleolithic open-air site of Revadim (Israel)

In this paper we present new data pertaining to the paleo-landscape characteristics at the Acheulian site of Revadim, on the southern coastal plain of Israel. Sedimentological, isotopic, granulometric and micromorphological studies showed that the archaeological remains accumulated in an active fluvial environment where channel action, overbank flooding and episodic inundation occurred. Measurements of total organic matter and its carbon isotopic composition indicate that the hominin activity at the site started at a period of relatively drier conditions, which coincided with erosion of the preceding soil sequence. This process led to the formation of a gently-undulating topography, as reconstructed by a GIS model. Later deposition documents relatively wetter conditions, as indicated by carbon isotopic composition. Formation processes identified at the site include fluvial processes, inundation episodes that resulted in anaerobic conditions and formation of oxide nodules, as well as small-scale bioturbation and later infiltration of carbonate-rich solutions that resulted in the formation of calcite nodules and crusts. The combination of micro-habitats created favorable conditions that repeatedly drew hominins to the area, as seen by a series of super-imposed archaeological horizons. This study shows that site-specific paleo-landscape reconstructions should play an important role in understanding regional variation among hominin occupations and in extrapolating long-term behavioral patterns during the Middle Pleistocene.