Revelation of a Functional Dependence of the Sum of Two Uniaxial Strengths/Hardness on Elastic Work/Total Work of Indentation

Dimensional and finite element analyses were used to analyze the relationship between the mechanical properties and instrumented indentation response of materials. Results revealed the existence of a functional dependence of (engineering yield strength sigma(E,y) + engineering tensile strength sigma(E,b))/Oliver & Pharr hardness on the ratio of reversible elastic work to total work obtained from an indentation test. The relationship links up the Oliver & Pharr hardness with the material strengths, although the Oliver & Pharr hardness may deviate from the true hardness when sinking in or piling up occurs. The functional relationship can further be used to estimate the SUM sigma(E,y) + sigma(E,b) according to the data of an instrumented indentation test. The sigma(E,y) + sigma(E,b) value better reflects the strength of a material compared to the hardness value alone. The method was shown to be effective when applied to aluminum alloys. The relationship can further be used to estimate the fatigue limits, which are usually obtained from macroscopic fatigue tests in different modes.

Digitized Processing Track Generation of a Computer Integrated Multi-Functional 5-Axis Laser Processing System

Based on the computer integrated and flexible laser processing system, an intelligent measuring sub-system was developed. A novel model has been built up to compensate the deviations of the main frame-structure, and a new 3-D laser tracker system is applied to adjust the accuracy of the system. To analyze the characteristic of all kind surfaces of automobile outer penal moulds and dies, classification of types of the surface、brim and ridge(or vale) area to be measured and processed has been established, resulting in one of the main processing functions of the laser processing system. According to different type of surfaces, a 2-D adaptive measuring method based on B?zier curve was developed; furthermore a 3-D adaptive measuring method based on Spline curve was also developed. According to the laser materials processing characteristics and data characteristics, necessary methods have been developed to generate processing tracks, they are explained in details. Measuring experiments and laser processing experiments were carried out to testify the above mentioned methods, which have been applied in the computer integrated and flexible laser processing system developed by the Institute of Mechanics, CAS.

Structural and functional characterization of the human CCR5 receptor in complex with HIV gp120 envelope glycoprotein and CD4 receptor by molecular modeling studies

The entry of human immunodeficiency virus (HIV) into cells depends on a sequential interaction of the gp120 envelope glycoprotein with the cellular receptors CD4 and members of the chemokine receptor family. The CC chemokine receptor CCR5 is such a receptor for several chemokines and a major coreceptor for the entry of R5 HIV type-1 (HIV-1) into cells. Although many studies focus on the interaction of CCR5 with HIV-1, the corresponding interaction sites in CCR5 and gp120 have not been matched. Here we used an approach combining protein structure modeling, docking and molecular dynamics simulation to build a series of structural models of the CCR5 in complexes with gp120 and CD4. Interactions such as hydrogen bonds, salt bridges and van der Waals contacts between CCR5 and gp120 were investigated. Three snapshots of CCR5-gp120-CD4 models revealed that the initial interactions of CCR5 with gp120 are involved in the negatively charged N-terminus (Nt) region of CCR5 and positively charged bridging sheet region of gp120. Further interactions occurred between extracellular loop2 (ECL2) of CCR5 and the base of V3 loop regions of gp120. These interactions may induce the conformational changes in gp120 and lead to the final entry of HIV into the cell. These results not only strongly support the two-step gp120-CCR5 binding mechanism, but also rationalize extensive biological data about the role of CCR5 in HIV-1 gp120 binding and entry, and may guide efforts to design novel inhibitors.

Molecular Characterization and Functional Commonality of Nucleophosmin/Nucleoplasmin in Two Cyprinid Fish

Nucleophosmin/nucleoplasmin has been studied mostly in mammals and amphibians. To clarify the characteristics and function of nucleophosmin/nucleoplasmin in teleost fish, we cloned a full-length cDNA sequence from two cyprinid fish, Carassius auratus gibelio and Carassius auratus. Molecular characterization and multiple sequence alignments suggested that they are the homologs of nucleophosmin. RT-PCR and Western blot detected a specific expression in gonads, and immunofluorescence localization revealed their distribution in oogenic and spermatogenic cells. Furthermore, a sperm decondensation function was demonstrated by immunodepletion and in vitro sperm decondensation experiments. The data suggest that the cloned nucleophosmin should share expressional and functional characterization with nucleoplasmin and therefore provide novel evidence for a functional commonality of nucleophosmin and nucleoplasmin in fish.

Expression regulation and functional characterization of a novel interferon inducible gene Gig2 and its promoter

Grass carp hemorrhagic virus (GCHV)-induced gene 2 (Gig2) is a novel gene previously identified from UV-inactivated GCHV-treated Carassius auratus blastulae embryonic (CAB) cells, suggesting that it should play a pivotal role in the interferon (IFN) antiviral response. In this study, a polyclonal anti-Gig2 antiserum was generated and used to study the inductive expression pattern by Western blot analysis, showing no basal expression in normal CAB cells but a significant up-regulation upon UV-inactivated GCHV, polyinosinic:polycytidylic acid (Poly I:Q and recombinant IFN (rIFN). However, constitutive expression of Gig2 is observed in all tested tissues from grass carp (Ctenopharyngodon idellus), and Poly I:C injection increases the relative amount of Gig2 protein in skin, spleen, trunk kidney, gill, hindgut and thymus. Moreover, the genomic sequence covering the whole Gig2 ORF and the upstream promoter region were amplified by genomic walking. Significantly, the Gig2 promoter contains three IFN-stimulated response elements (ISREs), nine GAAA/TfTC motifs and five gamma-IFN activating sites (GAS), which are the characteristics of genes responsive to both type I IFN and type 11 IFN. Subsequently, the complete Gig2 promoter sequence was cloned into pGL3-Basic vector, and its activity was measured by luciferase assays in the transfected CAB cells. The Gig2 promoter-driven construct is highly induced in CAB cells after treatment with Poly I:C or rIFN, and the functional capability is dependent on IFN regulatory factor 7 (IRF7), because its activity can be stimulated by IRF7. Collectively, the data provide strong evidence that Gig2 is indeed a novel IFN inducible gene and its expression is likely dependent on IRF7 upon Poly I:C or IFN. (C) 2009 Elsevier Ltd. All rights reserved.

Functional domains and the antiviral effect of the double-stranded RNA-dependent protein kinase PKR from Paralichthys olivaceus

The double-stranded RNA (dsRNA)-dependent protein kinase PKR is thought to mediate a conserved antiviral pathway by inhibiting viral protein synthesis via the phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2 alpha). However, little is known about the data related to the lower vertebrates, including fish. Recently, the identification of PKR-like, or PKZ, has addressed the question of whether there is an orthologous PKR in fish. Here, we identify the first fish PKR gene from the Japanese flounder Paralichthys olivaceus (PoPKR). PoPKR encodes a protein that shows a conserved structure that is characteristic of mammalian PKRs, having both the N-terminal region for dsRNA binding and the C-terminal region for the inhibition of protein translation. The catalytic activity of PoPKR is further evidence that it is required for protein translation inhibition in vitro. PoPKR is constitutively transcribed at low levels and is highly induced after virus infection. Strikingly, PoPKR overexpression increases eIF2 alpha phosphorylation and inhibits the replication of Scophthalmus maximus rhabdovirus (SMRV) in flounder embryonic cells, whereas phosphorylation and antiviral effects are impaired in transfected cells expressing the catalytically inactive PKR-K421R variant, indicating that PoPKR inhibits virus replication by phosphorylating substrate eIF2 alpha. The interaction between PoPKR and eIF2 alpha is demonstrated by coimmunoprecipitation assays, and the transfection of PoPKR-specific short interfering RNA further reveals that the enhanced eIF2 alpha phosphorylation is catalyzed by PoPKR during SMRV infection. The current data provide significant evidence for the existence of a PKR-mediated antiviral pathway in fish and reveal considerable conservation in the functional domains and the antiviral effect of PKR proteins between fish and mammals.

processline: visualizing time-series data in process industry

In modern process industry, it is often difficult to analyze a manufacture process due to its umerous time-series data. Analysts wish to not only interpret the evolution of data over time in a working procedure, but also examine the changes in the whole production process through time. To meet such analytic requirements, we have developed ProcessLine, an interactive visualization tool for a large amount of time-series data in process industry. The data are displayed in a fisheye timeline. ProcessLine provides good overviews for the whole production process and details for the focused working procedure. A preliminary user study using beer industry production data has shown that the tool is effective.

中国西部亚热带常绿阔叶林木本植物小枝功能生态学初步研究

常绿阔叶林以其富饶的生物资源、丰富的生物多样性和巨大的生态与环境效益引起了人们越来越大的重视，它的研究已成为国际植被科学界关注的主题之一。我国分布着世界上面积最大的亚热带常绿阔叶林，在世界植被中具有重要地位，它的分布表现出明显的地带性差异，存在着多样的植物群系及其对应的气候特征。但是在植物功能性状领域，与全球范围其它生物群系相比，常绿阔叶林物种的研究较少，其功能性状间、功能性状与环境间的关系尚不清晰。 本研究以常绿阔叶林木本植物的当年生小枝为对象，试图从小枝水平上的生物量分配格局、叶片大小与数量的权衡关系、小枝茎的构型效应、叶片元素化学计量学，以及小枝大小的成本与效益分析等方面，较为系统地揭示小枝水平上的植物功能性状间及其与气候间的关系。因此，在华西雨屏带内部的不同纬度设置峨眉－青城－雷波－平武的温度梯度进行比较，并对有降水差异的川西南偏湿性（雷波）与偏干性常绿阔叶林（西昌）进行对比研究，同时在不同山体进行不同海拔梯度的比较研究。 本文主要研究结果如下： （1）小枝生物量分配格局叶水平上，叶片重－叶柄重（Y轴vs.X轴,下同）呈斜率小于1的异速生长关系，表明叶柄对叶内部的生物量分配影响显著。小枝水平上，叶和茎的生物量以及它们与小枝总生物量间基本呈等速生长关系，表明大的小枝或大叶物种不一定在叶生物量的分配上占优势。不同生活型间，在小枝或者茎的生物量一定时，常绿物种叶片的生物量比例较落叶物种稍高。与温度和水分较优越（峨眉及其低海拔）的生境相比，在相对低湿（螺髻）与低温（平武）的生境中的植物会减少对叶的投入而增加对支撑部分的投资比例。 （2）小枝叶片大小与数量的权衡无论是不同气候带还是不同生活型以及不同海拔梯度，叶片大小与出叶强度基本都是呈负的等速生长关系，表明了叶片大小－数量在小枝水平上的权衡。在不同气候梯度的对比中，叶片数量（出叶强度）一定时，高温和高水分生境（峨眉）比低温（平武）和低湿（螺髻山）生境中的物种的叶片大小（质量和面积）更大，表明不同生境的比较中，小的叶片可能具有较高的出叶强度和更高的适合度收益。“出叶强度优势”（Leafingintensitypremium）假说可能不适宜解释不同生境物种叶片大小差异。 （3）小枝茎的构型效应虽然茎长和茎径与叶片大小都呈正相关关系，与出叶强度都呈负相关关系，但茎长/茎径比与叶/茎生物量之比呈负相关关系；与叶片的大小呈负相关关系，与出叶强度呈正相关关系。这说明小枝构型能影响小枝叶/茎生物量分配和叶大小－数量的权衡关系。其影响机制可能是小枝内部的顶端优势。另外，茎长/茎径比在低湿和低温等不利生境中的植物中较高，而在降水和温度较适宜环境中较低。 （4）叶片C、N、P化学计量学N含量和P含量，C/N比和比叶重（LMA,leafmassperarea）呈正的等速生长关系，而N和LMA，P和LMA呈负的等速生长关系。在LMA一定时，C/N比随着生境胁迫压力的增加而降低，N、P含量随着生境压力的增加而增加。在P含量一定时，N含量随着生境压力的增加而降低，即N/P比在生境条件较优（峨眉及其低海拔）时较高。常绿和落叶植物叶片的N/P比没有差异，在LMA一定时，常绿植物的N、P含量较高、C/N比较低。总之，植物的C、N、P化学计量学特征受叶片属性如LMA与气候，及其相互作用的影响。 （5）小枝大小的代价与效益分析、TLA与小枝总重总叶面积（TLA,totalleafarea，Y轴，下同）与总叶重（X轴）均呈斜率小于1的异速生长关系，TLA与小枝横切面积呈斜率为1的等速生长关系。表明叶片面积的增加总是小于叶重和小枝总重的增加，随着小枝的增大，它的叶面积支撑效率下降。在热量和降水优越的生境（峨眉及其低海拔）中，相同小枝重或者相同茎横切面积的小枝，其叶面积支撑效率较低湿与低温环境下（螺髻山、平武及高海拔）的高。 总体上，本文初步研究了小枝水平上可能存在的以下三种权衡关系：叶－茎生物量分配权衡；叶片大小－数量的权衡；小枝茎长－茎径的权衡关系，以及气候要素等对这三种权衡关系的影响。在此基础上，我们还讨论了这些权衡关系的可能形成机制，及其与物种生态适应的联系。本研究丰富了生活史对策中关于权衡关系的研究内容，为我国常绿阔叶林功能生态学研究积累了材料。 Evergreen broad-leaved forests are attracting much more attention from vegetation ecologists than ever before because of their abundant nature resource and biological diversity, and also great ecological benefits. China has the largest distribution of subtropical evergreen broad-leaved forests (temperate rainforests) that are typical and representative in the world. The forests span over more than ten degrees in latitude and more than 30 degrees in longitude, providing an ideal place to study plant functional ecology, i.e., the climatic effect on plant functional traits and the relationship between the traits. However, relative to the other biomes, there are few studies addressing functional ecology of the plant species from subtropical evergreen broad-leaved forests. In this study, I focused on the leaf size-twig size spectrum of the woody species of subtropical evergreen broad-leaved forests in southwestern china. I collected data on leaf size and number, twig size in terms of both mass and volume, and stem architecture from five temperate mountains, and then I analyzed the relationships between leaf and stem biomass and between leaf size and number, the effect of stem length/diameter ratio on biomass allocation and on the relationship between leaf size and number, leaf C:N:P stoichiometry, and the twig efficiency of supporting leaf area in relation to twig size. I also addressed the climate effect on the spectrum. The temperature gradient from warm to cool sites was represented by Emei Mountain, Qingchengshan, Leibo, and Pingwu, and the rainfall gradient was assumed to emerge from the comparison between Leibo (High) and Luojishan (Low). In addition, altitudinal effects were analyzed with comparisons between low and high altitudes for each mountains. My main results are as follows. Isometric relationships were found between leaf mass and twig mass and between lamina mass and twig mass, suggesting that the biomass allocation to leaves or laminas was independent of twig mass. Petiole mass disproportionably increase with respect to lamina mass and twig mass, indicating the importance of leaf petioles to the within-twig biomass allocation. In addition, the investigated species tended to have a larger leaf and lamina mass, but a smaller stem mass at a given twig mass at favorable environments including warm and humid sites or at low altitude than unfavorable habitats, which might be due to the large requirements in physical support and transporting safety for the species living at unfavorable conditions. Moreover, the evergreen species invested more in leaves and laminas than the deciduous at given stem or twig biomass within any specified habitats. Negative, isometric scaling relationships between leaf number and size broadly existed in the species regardless of climate, altitude, and life forms, suggesting a leaf size/number trade-off within twigs. Along the climatic gradients, at given leaf number or leafing intensity, the leaves were larger in the favorable environments than the poor habitats. This suggested that the fitness benefit gained by small leaves could be larger than that with high leafing intensity in the stressful sites. I concluded that the “leafing intensity premium” hypothesis was not appropriate to interpreting between-habitat variation in leaf size. Both stem length and diameter were positively correlated to leaf size but negatively correlated to leafing intensity. The ratio of stem length to diameter was negatively correlated to leaf mass fraction, and it was negatively correlated to leaf size but positively correlated to leafing intensity. This suggested that the stem architecture influenced twig biomass allocation and the relationship between leaf size and number. The mechanism underlying the architectural effect might lie in the apical dominance within twig. Moreover, the ratio was greater in unfavorable habitats but smaller in favorable environments. Positive, isometric relationships were found between N and P contents per leaf mass, and between C/N ratio and leaf mass per area (LMA), but N and P contents scaled negatively to LMA. C/N ratio decreased but N and P increased with increasing habitat stress at a given LMA. N content declined with increasing habitat stress at given P content. These indicated that N/P and C/N were higher but LMA was lower in favorable habitats than in the other circumstances. The evergreen and deciduous species were non-heterogeneous in N/P, but the evergreen species have higher N and P contents and lower C/N than the deciduous ones. In general, C:N:P stoichiometry were related to both climatic conditions and other important functional traits like LMA. Total leaf area (TLA) allometricly scaled to leaf mass with a slope shallower than 1, similar to the relationship between TLA and total twig mass (leaf mass plus stem mass), suggesting that TLA failed to keep pace with the increase of leaf mass and twig size. However, TLA scaled isometricly to twig cross-sectional area. Thus, it could be inferred that the twig efficiency of displaying leaf area decreased with increasing twig size. In addition, the efficiency at a given twig size was large in favorable than unfavorable habitats. In general, in this preliminary study, I studied three tradeoff relationships within twigs, i.e., between leaf and stem biomass, between leaf number and size, and between stem length and diameter, as well as the climatic effect on the relationships. I discussed the mechanisms underlying the tradeoff relationships in view of biophysics and eco-physiology of plants. I believe that this study can serve as important materials advancing plant functional ecology of subtropical forest and that it will improve the understanding of life history strategies of plants from this particular biome.

Density functional studies of diatomic LaO to LuO

Bond distances, vibrational frequencies, electron affinities, ionization potentials, dissociation energies and dipole moments of the title molecules in neutral, positively and negatively charged ions were studied by use of density functional method. Ground electronic state was assigned for each molecule. The bonding patterns were analyzed and compared with both the available data and across the series. It was found that besides ionic component, covalent bonds are formed between the metal s, d and f orbitals and oxygen p orbitals. Contrary to the well known lanthanide contraction, the bond distance is not regular from LaO to LuO for both neutral and charged molecules. An obvious population at 5d orbital was observed through the lanthanide series. 4f electrons also participate the chemical bonding for CeO to NdO and TbO to TmO. For EuO, GdO, YbO and LuO, 4f electrons tend to be localized. The spin multiplicity is regular for neutral and charged molecules. The spin multiplicity of the charged molecules can be obtained by -1 (or +1 for TbO+, DyO+, YbO- and YbO+) compared with the corresponding neutral molecules.

A key gene of the RNA interference pathway in the black tiger shrimp, Penaeus monodon: Identification and functional characterisation of Dicer-1

RNA interference (RNAi) is an evolutionarily conserved mechanism by which double-stranded RNA (dsRNA) initiates post-transcriptional silencing of homologous genes. Here we report the amplification and characterisation of a full length cDNA from black tiger shrimp (Penaeus monodon) that encodes the bidentate RNAase III Dicer, a key component of the RNAi pathway. The full length of the shrimp Dicer (Pm Dcr1) cDNA is 7629 bp in length, including a 51 untranslated region (UTR) of 130 bp, a 3' UTR of 77 bp, and an open reading frame of 7422 bp encoding a polypeptide of 2473 amino acids with an estimated molecular mass of 277.895 kDa and a predicted isoelectric point of 4.86. Analysis of the deduced amino acid sequence indicated that the mature peptide contains all the seven recognised functional domains and is most similar to the mosquito (Aedes aegypti) Dicer-1 sequence with a similarity of 34.6%. Quantitative RT-PCR analysis showed that Pm Dcr1 mRNA is most highly expressed in haemolymph and lymphoid organ tissues (P 0.05). However, there was no correlation between Pm Dcr1 mRNA levels in lymphoid organ and the viral genetic loads in shrimp naturally infected with gill-associated virus (GAV) and Mourilyan virus (P > 0.05). Treatment with synthetic dsRNA corresponding to Pm Dcr1 sequence resulted in knock-down of Pm Dcr1 mRNA expression in both uninfected shrimp and shrimp infected experimentally with GAV. Knock-down of Pm Dcr1 expression resulted in more rapid mortalities and higher viral loads. These data demonstrated that Dicer is involved in antiviral defence in shrimp. (c) 2007 Elsevier Ltd. All rights reserved.