Archeological evidence for utilizaton of wild rice

The use of wild rice during the late prehistoric period is suggested by charred wild rice grains associated with fire hearths and threshing pits in historically known, specialized harvesting sites. Similar wild rice grains imbedded in the clay lining of specialized threshing pits called "jig pots" confirms the prehistoric use.     

Flaxedil (gallamine triethiodide): evidence for a central action

A central action of gallamine triethiodide has been demonstrated in cats with permanently implanted electrodes that permit direct repetitive stimulation and recording of afterdischarges from cerebral cortex. Systemically administered gallamine produced a consistent and reproducible augmentation of duration of afterdischarge at doses just sufficient to produce skeletal muscle paralysis. Simultaneous examination of expiratory carbon dioxide, blood pressure, body temperature, blood glucose, and direct cortical response to brief single stimuli failed to reveal any consistent peripheral change to which the centrally observed effecte Could be attributed.     

d- 柠檬烯混合油剂对红火蚁的毒力及灭巢效果

d-柠檬烯是从芸香科植物中提取出的一种具有杀虫活性的天然单萜烯类化合物。以d-柠檬烯为有效成分并配以食品级植物油制成的80%、85%和90%d-柠檬烯混合油剂对红火蚁有翅繁殖蚁、工蚁、卵和蛹均具有良好的毒杀作用,其中90%d-柠檬烯混合油剂的效果最理想。各浓度d-柠檬烯混合油剂对红火蚁工蚁的作用时间均远小于有翅繁殖蚁。以单蚁巢处理的方式施用90%d-柠檬烯混合油剂,每蚁巢投放吸收了10m L混合油剂的海绵,药后7d灭巢率达97.44%(±2.56)%,与对照药剂0.1%氟虫腈粉剂灭巢率97.22%(±2.78)%差异不显著。以该方法施用90%d-柠檬烯混合油剂灭杀红火蚁巢效果显著,而且比传统的灌巢方法更简便。     

Kinetic evidence for five-coordination in AlOH(aq)2+ ion

Trivalent aluminum ions are important in natural bodies of water, but the structure of their coordination shell is a complex unsolved problem. In strong acid (pH < 3.0), Al(III) exists almost entirely as the octahedral Al(H2O)6(3+) ion, whereas in basic conditions (pH > 7), a tetrahedral Al(OH)(4- structure prevails. In the biochemically and geochemically critical pH range of 4.3 to 7.0, the ion structures are less clear. Other hydrolytic species, such as AlOH(aq)2+, exist and are traditionally assumed to be hexacoordinate. We show, however, that the kinetics of proton and water exchange on aqueous Al(III), coupled with Car-Parrinello simulations, support a five-coordinate Al(H2O)4OH2+ ion as the predominant form of AlOH(aq)2+ under ambient conditions. This result contrasts Al(III) with other trivalent metal aqua ions, for which there is no evidence for stable pentacoordinate hydrolysis products.     

《诗经》中商周时期农作物的考古学研究

商周时期是我国农业发展较快的时期,《诗经》中的大量诗歌涉及到了这一时期普遍种植的粟(小米)、麦(大麦)、来(小麦)、黍(谷)、稷(谷)、稻(大米)、粱、菽(豆)等粮食作物和瓜、葫、桃、枣等瓜果菜蔬以及桑、麻、葛等经济作物,并有考古发掘实物予以证实.先民在农作物种植过程中不断积累经验,为自身的生存和发展创造了更多的物质条件.     

First solvation shell of the Cu(II) aqua ion: evidence for fivefold coordination

We determined the structure of the hydrated Cu(II) complex by both neutron diffraction and first-principles molecular dynamics. In contrast with the generally accepted picture, which assumes an octahedrally solvated Cu(II) ion, our experimental and theoretical results favor fivefold coordination. The simulation reveals that the solvated complex undergoes frequent transformations between square pyramidal and trigonal bipyramidal configurations. We argue that this picture is also consistent with experimental data obtained previously by visible near-infrared absorption, x-ray absorption near-edge structure, and nuclear magnetic resonance methods. The preference of the Cu(II) ion for fivefold instead of sixfold coordination, which occurs for other cations of comparable charge and size, results from a Jahn-Teller destabilization of the octahedral complex.     

142Nd evidence for early (>4.53 Ga) global differentiation of the silicate Earth

New high-precision samarium-neodymium isotopic data for chondritic meteorites show that their 142Nd/144Nd ratio is 20 parts per million lower than that of most terrestrial rocks. This difference indicates that most (70 to 95%) of Earth's mantle is compositionally similar to the incompatible element-depleted source of mid-ocean ridge basalts, possibly as a result of a global differentiation 4.53 billion years ago (Ga), within 30 million years of Earth's formation. The complementary enriched reservoir has never been sampled and is probably located at the base of the mantle. These data influence models of Earth's compositional structure and require revision of the timing of global differentiation on Earth's Moon and Mars.     

Photoperiod evidence in the introduction of xanthium (cocklebur) to australia

North American populations of cocklebur Xanthium strumarium L. are diverse in form and show critical dark periods ranging from 7.75 to 10.75 hours (critical photoperiods of 13.25 to 16.25 hours). South American cockleburs also are diverse in form and response. American cockleburs are adapted to diverse ecosystems, which suggests that they are indigenous. In contrast, the widespread Australian populations known as Noogoora Burr are all of the chinense morphological complex and respond uniformly to photoperiod. Plants from southern Louisiana and Australia are nearly identical in external form and in critical dark period of 10.5 hours. Probably the Australian Noogoora Burr and the Indian monsoon form arrived in their present countries after 1800 as contaminants in cottonseed from the Mississippi Delta region.     

The S1-sensitive form of d(C-T)n.d(A-G)n: chemical evidence for a three-stranded structure in plasmids

Homopurine-homopyrimidine sequences that flank certain actively transcribed genes are hypersensitive to single strand-specific nucleases such as S1. This has raised the possibility that an unusual structure exists in these regions that might be involved in recognition or regulation. Several of these sequences, including d(C-T)n.d(A-G)n, are known to undergo a transition in plasmids to an underwound state that is hypersensitive to single strand-specific nucleases; this transition occurs under conditions of moderately acid pH and negative supercoiling. Chemical probes were used to examine the reactivity of a restriction fragment from a human U1 gene containing the sequence d(C-T)18.d(A-G)18 as a function of supercoiling and pH, and thus analyze the structure in this region. Hyperreactivity was seen in the center and at one end of the (C-T)n tract, and continuously from the center to the same end of the (A-G)n tract, in the presence of supercoiling and pH less than or equal to 6.0. These results provide strong support for a triple-helical model recently proposed for these sequences and are inconsistent with other proposed structures.     

Microbodies (peroxisomes) containing catalase in myocardium: morphological and biochemical evidence

Microbodies characterized by a single limiting membrane and finely granular matrix occur in mouse myocardium and appear in close spatial relation to mitochondria and sarcoplasmic reticulum. The presence of catalase in the microbodies is revealed cytochemically and confirmed biochemically by direct measurement of its activity in myocardial tissue fractions. It is suggested that the microbodies may play an important role in myocardial lipid metabolism.     

仙客来花药培养胚状体诱导影响因素的研究

把不同基因型仙客来的花药接种于B5培养基上进行培养，研究低温预处理、蔗糖浓度、基因型和植物生长调节剂等因素对仙客来花药胚状体诱导的影响。结果表明，花蕾经过4℃48h的预处理，能明显促进花药胚状体的诱导；仙客来花药在添加90g/L蔗糖的B5＋0．02mg／L（或0．1mg／L）NAA＋6-BA1．0mg／L培养基上胚状体诱导率最高；胚状体诱导率在基因型之间有明显的差异。     

Extinct (129)I in halite from a primitive meteorite: evidence for evaporite formation in the early solar system

Halite crystals from the Zag H3-6 chondrite contain essentially pure (monoisotopic) xenon-129 ((129)Xe) produced in the early history of the solar system by the decay of short-lived iodine-129 ((129)I) (half-life = 15.7 million years). Correlated release of (129)Xe and (128)Xe, produced artificially from (127)I by neutron irradiation, corresponds to an initial ((129)I/(127)I) ratio of (1.35 +/- 0.05) x 10(-4), close to the most primitive early solar system value. If the (129)Xe was produced by in situ decay, then the halite formed from an aqueous fluid within 2 million years of the oldest known solar system minerals.     

Ultradeep (>300 kilometers) ultramafic xenoliths: petrological evidence from the transition zone

The seismologically delineated transition zone, at depths between 400 and 670 kilometers, is a fundamental discontinuity in the earth that separates the upper mantle from the lower mantle. Xenoliths from within or close to the transition zone are dominated by pyropic garnet and associated pyroxene or mineralogically heterogeneous garnet lherzolite. These xenoliths show evidence for the high-pressure (90 to 120 kilobars) transformation of pyroxene to a solid solution of pyroxene in garnet (majorite) and silicon in octahedral coordination; low-pressure (less than 80 kilobars) exsolution of clinopyroxene or orthopyroxene from the original majorite is preserved. Although mineral modes and rock proportions below the transition zone and the relative amount of eclogite present cannot be accurately assessed from the xenoliths, it is likely that both majorite and beta-spinel help produce the observed seismic gradient of the transition zone.     

Molecular evidence for blocking erucic acid synthesis in rapeseed(Brassica napus L.) by a two-base-pair deletion in FAE1(fatty acid elongase 1)

DNA sequences of fatty acid elongase 1 genes FAE1.1(EA) and FAE1.2(EC) were isolated and characterized for 30 commercialized low erucic acid rapeseed(LEAR) cultivars in China. Four types of independent mutation leading to low erucic acid trait were found, i.e., a single-base transition(eA1), a two-base deletion(eC2) and four-base deletion(eC4) as well as single-base transition with a four-base deletion(eA*). Three genotypes, i.e., eA1eA1eC2eC2, eA1eA1eC4eC4 and eA*eA*eC4eC4 were responsible for LEA content in storage lipids of different rapeseed cultivars. Most of the LEAR cultivars had a genotype of eA1eA1eC2eC2, which were descended from the first LEAR cultivar, Oro. Yeast expression analysis revealed that two-base-pair(AA) deletion(eC2) at the base sites of 1 422–1 423 in the C genome FAE1 gene resulted in the absence of the condensing enzyme and led to the failure to produce erucic acid. Coexpression of FAE1 and ketoacyl-CoA reductase(KCR) or enoyl-CoA reductase(ECR) was found in high erucic acid rapeseed(HEAR) but not in LEAR(eA1eA1eC2eC2 or eA1eA1eC4eC4). Moreover, KCR and ECR were still coordinately regulated in eA1eA1eC2eC2 or eA1eA1eC4eC4 genotypes, suggesting that the expression of two genes was tightly linked. In addition, specific detection methods were developed by high-resolution melting curve analysis in order to detect eA1 and eC4.     

No evidence for an effect of Wolbachia on mtDNA variation and evolution in natural populations of Sesamia inferens(Lepidoptera: Noctuidae)

Wolbachia are widespread maternally-inherited endosymbiotic bacteria that infect numerous arthropods.This study represents a thorough survey of the Wolbachia infection patterns in the pink stem borer,Sesamia inferens(Walker),an important rice pest in China,based on nucleotide comparisons for the surface protein(wsp)and cell division protein(ftsZ)genes.The effects of Wolbachia on mtDNA variation and evolution of S.inferens were also investigated.Although we identified six genetically diverse strains,we found infections to be infrequent,with only 7.8%of hosts infected,and identified geographical differences in infection rates between southern and northern populations.Nucleotide indexes(haplotype diversity(Hd),nucleotide diversity(π)and number of variable sites(S)of mtDNA in infected populations were not significantly lower or higher than that in the uninfected populations.Furthermore,there was no association between Wolbachia infection status and phylogeny of mtDNA haplotypes.Analysis of molecular variance(AMOVA)showed that significant differentiation mainly existed within groups rather than among the groups.Additionally,using Tajima’s D and Fu’s F values,the mtDNA genes did not deviate significantly from neutral evolution.Taken together these results indicate that currently there were no effects of Wolbachia infection on host mtDNA variation and evolution in S.inferens.