T-W-DIamond,a Stone Ring Site in Northern Colorado

Abstract

The T-W-Diamond Site, 4LR200, is a large teepee ring village on the? edge of the High Plains in northern Colorado. Seventeen out of the 47 remaining stone ring areas were excavated or tested by the Colorado State University Archae-ological Field School in 1971. Artifacts, fire hearths and midden materials were scarce but indicated the domestic nature of the structures. Stone and ceramic artifacts indicate cultural affiliations with the Late Prehistoric period as reported at Birdshead Cave, and the Piney Creek sites in Wyoming; and at the Agate Bluff Rock Shelters, and the Dipper Gap site in northern Colorado. Carbon-14 dates of A. D. 1020±230 years and A.D. 1170±220 years support the time of the occupation. A third date of A.D. 400±340 seems improbably early. It is hypothesized that the village was occupied seasonally for a short time by a small group of people, perhaps of Shoshonean affiliation, exploiting a mixedbase subsistence economy.     

Synthetic Studies Towards a Novel,Chemical Stable,Abasic Site Analogue of DNA

Abstract

We synthesized the phosphinate 7 via photoaddition of methanol to the α, βunsaturated deoxyribono lactone as the key step, followed by an Arbusov reaction for the introduction of phosphorous. Precursor 7 serves for the synthesis and incorporation into DNA of a novel chemically stable abasic site analogue that might act as an inhibitor for DNA glycosylases.     

古人类遗址湖北郧西黄龙洞的铀系年代

湖北郧西黄龙洞为近年来发现的晚期智人遗址。本文报道该地点具明确层位意义的洞穴次生碳酸盐岩和骨化石样铀系测年的结果。含文化堆积下伏一局部钙板的年代为约100ka BP, 其中部偏上一局部钙板为约77ka BP, 表层钙板形成于27—57ka BP间。人类化石和石制品出土于文化堆积的底部, 其年代应在57—100ka BP, 并很可能在77—100ka BP间。与人牙化石同层的四枚犀牛牙化石在35—72ka BP间, 与基于次生碳酸盐岩的年代框架没有冲突。本文结果为中国现代人类的早期出现和距今40—100ka BP间有人类活动提供了有力证据。     

fpr,a Deficient Xer Recombination Site from a Salmonella Plasmid,Fails To Confer Stability by Dimer Resolution: Comparative Studies with the pJHCMW1 mwr Site

Salmonella plasmid pFPTB1 includes a Tn3-like transposon and a Xer recombination site, fpr, which mediates site-specific recombination at efficiencies lower than those required for stabilizing a plasmid by dimer resolution. Mutagenesis and comparative studies with mwr, a site closely related to fpr, indicate that there is an interdependence of the sequences in the XerC binding region and the central region in Xer site-specific recombination sites.Xer site-specific recombination stabilizes many plasmids by resolving dimers created through recombination events (17, 18). Most plasmids'' Xer recombination sites consist of a core recombination site (CRS) that includes two 11-nucleotide binding sites for XerC and XerD, separated by a 6- to 8-nucleotide central region, and a stretch of about 180 bp known as accessory sequences (AS) that bind the architectural proteins PepA and ArgR (Fig. ​(Fig.1A).1A). These elements form a synaptic complex (11, 14) where XerC is activated by interaction with XerD and catalyzes the exchange of the first pair of strands, which results in the formation of a Holliday junction (3, 6) that, in the case of cer (ColE1) or mwr (pJHCMW1), is resolved by Xer-independent processes (Fig. ​(Fig.1B)1B) (2).Open in a separate windowFIG. 1.(A) Comparative diagrams of pFPBT1 and pJHCMW1. The black lines represent regions of homology. The Tn3-like transposons in both plasmids are shown at the correct locations but are not to scale. The gray bar between the plasmid maps identifies the replication (REP) regions, which share 97% homology. The numbers indicate the coordinates in the GenBank database (pJHCMW1, accession number {"type":"entrez-nucleotide","attrs":{"text":"AF479774","term_id":"19698424","term_text":"AF479774"}}AF479774; pFPBT1, accession number {"type":"entrez-nucleotide","attrs":{"text":"AJ634602","term_id":"46019644","term_text":"AJ634602"}}AJ634602). The location and a diagram of the Xer site-specific recombination site are shown below the plasmid diagrams. The different regions of the Xer site-specific recombination site, shown with different colors, are not drawn to scale. ARG, ARG box, ArgR binding site. (B) Schematic representation of dimer resolution mediated by the Xer site-specific recombination reaction. For clarity, the proteins are shown only in the synaptic complex (red rectangle, XerD; green rectangle, XerC; brown oval, PepA; yellow oval, ArgR). Blue lines represent AS, and the CRS is the only region shown with a double line (green and red) representing the two DNA strands. The green line represents the DNA strand exchanged by XerC. Only the Xer-independent pathway of resolution of the Holliday junction (demonstrated for cer and mwr) is shown. (C) Comparison of the nucleotide sequences of mwr, fpr, and cer. The ARG box and different regions of the CRS are individually boxed. The ARG box consensus sequence is shown at the top. Nucleotides mutated in different derivatives are indicated by an arrow (central region) or a star (ARG box). Black dots identify the most conserved nucleotides among several sites (8).The pJHCMW1 plasmid, originally isolated from Klebsiella pneumoniae, includes mwr and the Tn3-like transposon Tn1331, which transposes through a replicative pathway (15, 20, 22). The efficiency of Xer-mediated dimer resolution at mwr when Escherichia coli is cultured in L broth is below the levels needed to stabilize the plasmid; instead, stabilization is mediated by the Tn1331 resolvase acting at the res site (13, 21). However, the efficiency of Xer-mediated dimer resolution at mwr is substantially increased when the cells are cultured in low-osmolarity broth (4, 13). The low levels of dimer resolution observed when cells are cultured in L broth seem to be due to a weak interaction of the substandard mwr ARG box with ArgR, hindering proper formation of the synaptic complex. When the cells are cultured in low-osmolarity growth medium, an increase in the density of negative supercoiling results in an increased stability of the synaptic complex and/or efficiency of catalysis by XerC, leading to a significantly higher efficiency of dimer resolution (23). These characteristics make pJHCMW1 a very unusual plasmid that includes a Xer recombination site that, under certain conditions, is unable to confer stability by resolution of dimers; instead, that function is performed by the cointegrate resolution system of Tn1331. In this study, we report that another plasmid, Salmonella Typhimurium plasmid pFPTB1 (12), includes a Xer recombination site with high homology to mwr (Fig. ​(Fig.1C),1C), from here on called fpr (pFPTB1 Xer recombination site), and a copy of the replicative transposon Tn3-ΔTn1721 (Fig. 1A and C). Plasmid pFPTB1 is the second case reported in which stabilization by dimer resolution is provided by the insertion of a replicative transposon rather than a resident Xer recombination site, suggesting that rather than being exceptional, pJHCMW1 and pFPTB1 may be part of a group of plasmids with these characteristics.The E. coli strains and plasmids used in this study are described in Table ​Table1.1. Plasmid pFPRTT1 was generated by inserting a synthetic DNA fragment with the fpr site sequence (coordinates 2221 to 2520, accession number {"type":"entrez-nucleotide","attrs":{"text":"AJ634602","term_id":"46019644","term_text":"AJ634602"}}AJ634602) from pFPTB1 (12) into the EcoRV site of pUC57 (accession number {"type":"entrez-nucleotide","attrs":{"text":"Y14837","term_id":"2440162","term_text":"Y14837"}}Y14837). Plasmids pTTT1 through pTTT6 were generated by site-directed mutagenesis using the QuikChange II XL kit (Stratagene). Lennox L broth (containing 2% [wt/vol] agar in the case of solid medium) is called high-osmolarity medium (containing 0.5% NaCl; osmolality, 209 mmol/kg); for low-osmolarity growth medium, NaCl was omitted (osmolality, 87 mmol/kg) (13, 23). In vivo resolution assays were carried out as described by Pham et al. (13). Although pFPTB1 has been isolated from S. Typhimurium, we decided it was appropriate to carry out the in vivo experiments with E. coli because it has been shown before that the Xer recombination proteins of S. Typhimurium can substitute for and are highly homologous to the corresponding proteins of E. coli (7), K. pneumoniae Xer recombination proteins share high homology with those of E. coli and can complement mutants, we have observed no difference in levels of resolution with some sites such as dif and cer and minimal differences with mwr (4), and pJHCMW1-like replicons such as pGY1 (Salmonella) (9), pVI678 (E. coli; accession number {"type":"entrez-nucleotide","attrs":{"text":"NC_008597","term_id":"118480566","term_text":"NC_008597"}}NC_008597), and pTKH11 (Klebsiella) (25) are being found in nature across the members of the family Enterobacteriaceae rather than in one specific genus.

TABLE 1.

Strains and plasmids used in this study

DNA, a Possible Site of Action of Aluminum in Rhizobium spp

Al was found to penetrate the cell envelopes of both sensitive and tolerant Rhizobium strains and bind to DNA in vivo. Despite causing a reduction in viability, Al stimulated DNA synthesis in the sensitive strain, which suggested that an excision repair mechanism was operating. The Al-stimulated DNA synthesis was reduced by the simultaneous addition of chloramphenicol. In contrast to the sensitive strain, DNA synthesis was unaffected by Al binding to DNA in the tolerant strain. It is proposed that Al enters the cell and binds to the DNA helix, increasing stabilization and preventing successful replication. Different repair mechanisms appear to operate in response to Al in tolerant and sensitive strains.     

Factors Affecting Redd Site Selection, Hatching, and Emergence of Brook Charr, Salvelinus Fontinalis, in an Artificially Enhanced Site

We measured microhabitat characteristics, hatching and emergence success of brook charr, Salvelinus fontinalis, in a series of sites selected and not selected by individuals spawning in an artificially enhanced lake outlet. Differences between the physico-chemistry of surface and interstitial water were small and did not suggest the presence of groundwater seepage. The mean surface water velocity was significantly higher in selected than non-selected sites during the incubation and emergence periods. Differences in interstitial water flow were not detected. Overall, selected substrate was coarser and contained a lower proportion of fine particles than non-selected substrate, as determined by the geometric mean diameter of particles, the proportion of fine particles (<1mm), and the Fredle index. The proportion of fine particles was correlated with sediment loading in incubators. A two-way ANOVA showed no significant effect of sites (selected versus non-selected) but did show a significant effect of the incubation substrate (Astro-turf, selected substrate, non-selected substrate) on both the hatching and emergence success; the percentages of hatching and emergence were significantly higher in Astro-turf than in non-selected substrate, with selected substrate being intermediate. The results of this study suggest that redd site selection by brook charr is based on surface water velocity and substrate characteristics (granulometry and proportion of fine particles) that in turn affect egg survival. It is possible that the lower proportion of fine particles in selected sites (and incubators) is related to their higher water velocity, which could carry away fine particles that reduce the availability of oxygenated water to the embryos. In the same way, higher water velocity could act as a proximate cue in the absence of groundwater seepage or interstitial water flow for individuals to select suitable sites for spawning and egg incubation.     

Grooved Stones from Zawi Chemi Shanidar, a Protoneolithic Site in Northern Iraq

Grooved stones appear as a new cultural element in Epipaleolithic-Protoneolithic sites (dating from ca. 9000–6000 B.C.) in a broad geographic zone from Southwest Asia to North Africa. Similar objects have been recorded from archeological and ethnographic contexts in both the Old World and the New World. Ethnographic and other evidence has shown that the several types of grooved stones are associated with a variety of functions, mainly related to the manufacture and use of arrows and arrow shafts. It is suggested that these tools may be associated with the discovery and diffusion of the bow and arrow .     

Crystal Structure of the Ectoine Hydroxylase,a Snapshot of the Active Site

Ectoine and its derivative 5-hydroxyectoine are compatible solutes that are widely synthesized by bacteria to cope physiologically with osmotic stress. They also serve as chemical chaperones and maintain the functionality of macromolecules. 5-Hydroxyectoine is produced from ectoine through a stereo-specific hydroxylation, an enzymatic reaction catalyzed by the ectoine hydroxylase (EctD). The EctD protein is a member of the non-heme-containing iron(II) and 2-oxoglutarate-dependent dioxygenase superfamily and is evolutionarily well conserved. We studied the ectoine hydroxylase from the cold-adapted marine ultra-microbacterium Sphingopyxis alaskensis (Sa) and found that the purified SaEctD protein is a homodimer in solution. We determined the SaEctD crystal structure in its apo-form, complexed with the iron catalyst, and in a form that contained iron, the co-substrate 2-oxoglutarate, and the reaction product of EctD, 5-hydroxyectoine. The iron and 2-oxoglutarate ligands are bound within the EctD active site in a fashion similar to that found in other members of the dioxygenase superfamily. 5-Hydroxyectoine, however, is coordinated by EctD in manner different from that found in high affinity solute receptor proteins operating in conjunction with microbial import systems for ectoines. Our crystallographic analysis provides a detailed view into the active site of the ectoine hydroxylase and exposes an intricate network of interactions between the enzyme and its ligands that collectively ensure the hydroxylation of the ectoine substrate in a position- and stereo-specific manner.     

一个具有S位点的水稻类受体激酶OsSRL参与干旱胁迫反应

植物在进化过程中针对干旱、高盐和高低温等逆境胁迫形成了多种适应机制, 植物类受体激酶作为重要的细胞信号传递分子在植物生长和抗逆境胁迫中发挥着重要功能。该文发现一个具有S位点的类受体激酶基因OsSRL可能参与水稻(Oryza sativa)的干旱胁迫反应。利用RNAi技术降低OsSRL的表达水平后, 转基因植株抗旱性增强, 并表现出幼苗存活率、叶绿素含量及鲜重增加等表型。进一步的研究表明30%PEG和100 μmol·L^–1ABA可诱导OsSRL基因表达, 利用RNAi降低其表达导致干旱诱导基因RAB16A及LEA3表达水平明显增加。表达模式分析发现OsSRL在胚芽、胚根、根、茎节以及花中表达。以上结果表明, OsSRL表达水平的降低增强植物的干旱耐受性, 其作为一个S-位点样类受体激酶可能参与了水稻对干旱胁迫的反应。     

世界自然遗产预选地施秉鱼类物种组成

通过对贵州省中国南方喀斯特第二批世界自然遗产提名预选地施秉县的鱼类物种组成进行调查,共采集到鱼类46种,隶属于7目15科39属,其中鲤形目(Cypriniformes) 有28种,占本次调查的61％.在物种组成上,土著鱼类是该区域河流的主体,有40种,占87％;外来鱼类有6种,约占13％.其中外来入侵物种有食蚊鱼(Gambusia affinis);大银鱼(Protosalanx hyalocroaniah属于人工放养;从人工养殖地逃逸到野外的鱼类有4种,分别为草鱼(Ctenopryngodon idellus)、鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)和团头鲂(Megalobrama amblycephala).     

Surface and Airborne Arsenic Concentrations in a Recreational Site near Las Vegas,Nevada, USA

Elevated concentrations of arsenic, up to 7058 μg g^-1 in topsoil and bedrock, and more than 0.03 μg m^-3 in air on a 2-week basis, were measured in the Nellis Dunes Recreation Area (NDRA), a very popular off-road area near Las Vegas, Nevada, USA. The elevated arsenic concentrations in the topsoil and bedrock are correlated to outcrops of yellow sandstone belonging to the Muddy Creek Formation (≈ 10 to 4 Ma) and to faults crossing the area. Mineralized fluids moved to the surface through the faults and deposited the arsenic. A technique was developed to calculate airborne arsenic concentrations from the arsenic content in the topsoil. The technique was tested by comparing calculated with measured concentrations at 34 locations in the NDRA, for 3 periods of 2 weeks each. We then applied it to calculate airborne arsenic concentrations for more than 500 locations all over the NDRA. The highest airborne arsenic concentrations occur over sand dunes and other zones with a surficial layer of aeolian sand. Ironically these areas show the lowest levels of arsenic in the topsoil. However, they are highly susceptible to wind erosion and emit very large amounts of sand and dust during episodes of strong winds, thereby also emitting much arsenic. Elsewhere in the NDRA, in areas not or only very slightly affected by wind erosion, airborne arsenic levels equal the background level for airborne arsenic in the USA, approximately 0.0004 μg m^-3. The results of this study are important because the NDRA is visited by more than 300,000 people annually.     

早籼稻碾磨品质品种、地点、品种×地点互作效应的研究

以浙江省1995年早籼稻品种区域试验6个试点参试品种碾磨品质测定结果为试验材料,用多元分析法探讨了糙米率、精米率、整精米率3个碾磨品质的品种(基因型)、地点、品种×地点互作效应和各效应内碾磨品质间的相关关系,进行了参试品种互作效应检验。分析结果表明,糙米率、精米率以品种效应为主,整精米率性状以环境效应最大。相关分析显示,糙米率、精米率呈较强正相关,糙米率、精米率与整精米率均无相关关系。参试品种互作效应检验显示,多数品种整精米率均存在基因型×地点交互作用,糙米率、精米率多数品种较稳定。 Abstract:The genotype,test site,genotype×site effects on brown rice rate,milled rice recovery and head rice recovery as well as the correlation coefficients between the milling qualities within various effects were approached by using multiple analysis method with the data collected from early season indica rice varieties tested in regional trial in Zhejiang Province.Results showed that brown rice rate,milled rice recovery were predominantly affected by genotype.While head rice recovery was mostly conditioned by environment effect.Correlation analysis displayed that there were positive correlation between brown rice rate and milled rice rate.However,no correlation between brown rice rate,milled rice recovery and head rice recovery was found.The analysis of genotype×site of the varieties tested displayed that head rice recovery of the most tested varieties is involved with the interaction effects between the two components,while brown rice rate,milled rice recovery of the most tested varieties were more stable.     

Site selection in a polymorphic mangrove snail

Three species of littorinid snail live on mangroves of the genus Rhizophora on the north coast of Papua New Guinea. They have recently been placed in the genus Littoraria. The species are L. scabra and L. intermedia , which are monomorphic and cryptic and live on bark, and L. pallescens which is polymorphic and lives in foliage. Littoraria intermedia was found mostly on mangroves facing on to partially fresh water, while L. scabra occurred only at sites facing on to the sea; L. pallescens occurs at both types of site. When kept together in plastic containers, L. pallescens shows a greater propensity to climb than the other two species. The morphs of L. pallescens are principally yellow, orange or dark. Orange is present at a frequency of 0–9% and yellow at 10–50%. There is little evidence of geographical variation in frequency over 80 km of coast, although one central locality has a significantly higher frequency of yellow than sites to the north or south of it. Throughout the tropics where the species occurs, orange is the rarest and yellow usually the next rarest morph. Larger individuals are on average higher in the foliage than smaller ones, and there is a higher frequency of yellows among larger shells than smaller ones. As the air temperature increases, a progressively larger fraction of a sample was found to be on the under-surfaces of leaves rather than on the upper epidermis or on flower or leaf buds. When over 30% of a sample is situated on lower surfaces there is a significant excess of yellows and a deficiency of darks on the upper surfaces. This indicates that individuals selectively take up different positions depending on morph colour, resulting in a degree of optimal background matching. Such a choice of location may be of direct relevance to the maintenance of the polymorphism. A difference in morph frequency between the same sites examined in 1979 and 1984 is interpreted as being a result of site selectivity.     

A Bone Needle From a Midland Site

Abstract

Investigation of a western Texas campsite containing an apparently discrete assemblage of Midland points and other tools has yielded part of a tiny bone needle.     

The West Island Site, 14PH10, A Keith Focus Plains Woodland Site in Kirwin Reservoir Phillips County,Kansas

Abstract

Salvage excavations at a badly eroded site, now an island in the Kirwin Reservoir of west-central Kansas, produced pottery and other artifacts indicative of the Keith Focus. Although the site remains undated, it should fall at ca. A. D. 600.     

关于金盆洞遗址的古地理古气候古生态问题

2004年金盆洞遗址被第二次发掘。新的化石材料表明,金盆洞产有8目18科25属31种的化石。金盆洞动物群的地质时代为中更新世的最晚期, 相当于MIS6,或欧洲的RISS冰期, 或世界上的倒数第二次冰期。这个动物群既展示了森林环境, 也展示了灌木丛林和草原环境。长江以南的茂密的丛林阻碍了江南各哺乳动物群之间的交流。     

Restoration of a Landfill Site in Berlin, Germany by Spontaneous and Directed Succession

We report on spontaneous and directed succession on a dry sandy landfill site of low fertility at Berlin‐Malchow, Germany. Changes in species composition and cover were followed on unmown and mown permanent plots of 2 × 2 m size through 5 years of vegetation development. Species richness on unmown plots was relatively constant during the time of observation, with 20 to 25 species per 4 m². Total cover of unmown plots continuously increased from approximately 10% in the first year to 80% in the fifth year. There are no clearly discernible sequential successional stages until present. The species composition includes species of all life forms, which colonized the site immediately after the initiation of the succession process representing the initial floristic composition type of vegetation development. However, perennial grasses and herbs gradually increased in cover up to approximately 40%. Woody plants were also present from the first year of succession and increased up to more than 20% cover in the fifth year, forming a shrub layer (>0.5 m) after the second year. Mowing significantly increased species richness, which was evident from the third year onward. This effect was mainly due to the reduction of the tall perennial grass Calamagrostis epigejos. Solidago canadensis and woody species were also significantly affected (lower cover and height), whereas short perennial herbs like Plantago lanceolata and Trifolium repens benefited from mowing.