464 research outputs found

    Isolation, characterisation and molecular evolution of the actin gene family of the New Zealand black-footed abalone, Haliotis iris.

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    Molluscs are biologically important; they form a diverse taxon and the most well known members of the Lophotrochozoa, the most understudied Bilaterian group. Despite this importance, few studies have characterised molluscs at the genetic level. The New Zealand black-footed abalone Haliotis iris, an economically and culturally valued species, was chosen as a model for genetic characterisation of a molluscan actin gene family. In H. iris, actin is essential for the production of a large muscular foot, which forms the bulk of the body mass. The structure, expression and evolution of actin genes were investigated to elucidate the function of the actin gene family in H. iris. H. iris actin genes were isolated by PCR using gene subtype-specific primers designed from previously characterised partial H. iris actin sequences and generic primers derived from H. rufescens (Californian red abalone) and Cyprinus carpio (common carp). Three full length genes, H.irisA1, H.irisA2 and H.irisA3, and three partial genes, H.irisA1a, H.irisA1b and H.irisA1c, were isolated. The full length genes showed 82-95% sequence similarity to mollusc actin gene sequences deposited in GenBank. Sequence conservation confirmed the identity of the putative actin genes. The six genes contained a single variable length intron between codons 41 and 42. Intron lengths were: 174 nt, H.irisA1; 1,078 nt, H.irisA2; 581 nt, H.irisA3; 301 nt, H.irisA1a; 282 nt, H.iris1l and 229 nt, H.irisA1c. The predicted proteins of the full length genes contained 375 aa and lacked the second amino acid usually found in invertebrate actin proteins. Southern hybridisation of genomic DNA suggested there was a large gene family composed of at least eight members. The expression of H.irisA1, H.irisA2 and H.irisA3 in developmental stages and adult tissues was investigated by RT-PCR. RT-PCR demonstrated differential expression of H. iris actin genes during development and in adult tissues. H.irisA1 and H.irisA2 were expressed at low levels in fertilised eggs and blastula, with expression increasing in trochophore and veliger larvae. H.irisA3 was not expressed in eggs, but was faintly detected in blastula and highly expressed in trochophore and veliger larvae. H.irisA1 was ubiquitously expressed in adult gill, gonad, hepatopancreas, foot and mantle tissue, suggesting it may be a cytoplasmic-type actin. H.irisA2 was expressed in all tissues except the hepatopancreas, although low expression may not have been detectable by electrophoresis of RT -PCR products. Further characterisation is required to confirm whether H.irisA2 encodes a cytoplasmic-type actin. H.irisA3 was expressed at high levels in the muscular foot and mantle, and was faintly detected in gonad, suggesting it may be a muscle type actin. Phylogenetic analyses of H. iris actin genes and other molluscan actin genes available on GenBank were performed using maximum parsimony and maximum likelihood methods. Analyses suggested that haliotid actins can be divided into two orthologous clades, the first clade containing H.irisA1, H.irisA1a, H.irisA1b, H.irisA1c, H.virgA1a, H.virgA1b, H.virgA1c and H. Rufescens actin, the second clade containing H.irisA2, H.irisA3 and H. discus hannai actin. Orthology indicated that the last common ancestor of haliotids had at least two actin genes. Clustering of actin genes from individual haliotid species within orthologous actin gene clades suggests paralogy resulting from duplication of actin genes within species. Evidence for gene orthology between mollusc actin genes was found, but further characterisation of actin genes from other mollusc species is required to infer the evolutionary significance of orthology

    Электроснабжение обжигового цеха, никелевого завода

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    Дипломный проект обжигового цеха "Никелевого завода", объект исследования является электрическая часть "Никелевого завода". Проектирования схем электроснабжения от подстанции энергосистемы, до электроприемника. Выбор кабелей и проводов, коммуникационное оборудования. Экономический расчет капитальных затрат на сооружение этой схемы.The graduation project of the roasting shop of the "Nickel Plant", the object of research is the electrical part of the "Nickel Plant". Designing power supply schemes from a power system substation, to an electrical receiver. Selection of cables and wires, communication equipment. Economic calculation of capital costs for the construction of this scheme

    Prosociality in a despotic society

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    Prosociality is the intent to improve others’ well-being. Existing hypotheses postulate that enhanced social tolerance and inter-individual dependence may facilitate prosocial preferences, which may favor the evolution of altruism. While most studies are restricted to “tolerant” (cooperatively breeding and self-domesticated) species, despotic societies provide an alternative opportunity to investigate prosociality due to nepotism and ample inter-individual dependencies. Japanese macaques live in hierarchical matrilineal societies, with strong kin bonds. Besides, tolerance among non-kin may persist through reciprocity. Using a group service food-provision paradigm, we found prosocial preferences in a semi free-ranging group of Japanese macaques. The extent of provisioning was at levels comparable to tolerant species. Dyadic tolerance predicted the likelihood and magnitude of provisioning, while kinship predicted the magnitude. We emphasize the role of a complex socio-ecology fostering individual prosocial tendencies through kinship and tolerance. These findings necessitate a framework including different forms of interdependence beyond the generally tolerant species

    Tracing Multiple Scattering Patterns in Absolute (e, 2e) Cross Sections for H₂ and He over a 4π Solid Angle

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    Absolutely normalized (e,2e) measurements for H2 and He covering the full solid angle of one ejected electron are presented for 16 eV sum energy of both final state continuum electrons. For both targets rich cross-section structures in addition to the binary and recoil lobes are identified and studied as a function of the fixed electron\u27s emission angle and the energy sharing among both electrons. For H2 their behavior is consistent with multiple scattering of the projectile as discussed before. For He the binary and recoil lobes are significantly larger than for H2 and partly cover the multiple scattering structures. To highlight these patterns we propose a alternative representation of the triply differential cross section. Nonperturbative calculations are in good agreement with the He results and show discrepancies for H2 in the recoil peak region. For H2 a perturbative approach reasonably reproduces the cross-section shape but deviates in absolute magnitude

    Presence of Nonhemolytic Pneumolysin in Serotypes of Streptococcus pneumoniae Associated with Disease Outbreaks

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    Pneumolysin is an important virulence factor of the human pathogen Streptococcus pneumoniae. Sequence analysis of the ply gene from 121 clinical isolates of S. pneumoniae uncovered a number of alleles. Twenty-two strains were chosen for further analysis, and 14 protein alleles were discovered. Five of these had been reported previously, and the remaining 9 were novel. Cell lysates were used to determine the specific hemolytic activities of the pneumolysin proteins. Six strains showed no hemolytic activity, and the remaining 16 were hemolytic, to varying degrees. We report that the nonhemolytic allele reported previously in serotype 1, sequence type (ST) 306 isolates is also present in a number of pneumococcal isolates of serotype 8 that belong to the ST53 lineage. Serotype 1 and 8 pneumococci are known to be associated with outbreaks of invasive disease. The nonhemolytic pneumolysin allele is therefore associated with the dominant clones of outbreak-associated serotypes of S. pneumonia

    First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength

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    We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations all corroborate the existing models for SASE FELs.Comment: 6 pages including 6 figures; e-mail: [email protected]

    Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR

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    Simulation results for future measurements of electromagnetic proton form factors at \PANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel pˉpe+e\bar p p \to e^+ e^- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.\textit{i.e.} pˉpπ+π\bar p p \to \pi^+ \pi^-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance

    Проектирование автоматизированной групповой замерной установки при разработке Макарьевского месторождения нефти на проточном-1 лицензионном участке недр Томской области

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    В данной дипломной работе произведено обоснование оптимальной конфигурации и проектирование автоматизированной группой замерной установки для системы сбора продукции эксплуатационных скважин в рамках прогноза эффективности разработки Макарьевского месторождения Томской области.In this graduation work the study of the optimal configuration and design of automated group measuring system for the collection system of production wells within the forecast development efficiency Makar deposits of Tomsk region
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