512 research outputs found

    THE EFFECTS OF HETEROLOGOUS ANTI-THYMOCYTE SERA IN MICE : III. HIGH SUSCEPTIBILITY OF GERMFREE MICE TO THE SUPPRESSIVE EFFECTS OF IGG FROM RABBIT ANTI-MOUSE THYMOCYTE SERUM

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    A quantitative graft-vs.-host (GVH) assay was used to compare the reactivity of spleen cells from germfree (GF) and conventionally reared (CV) mice against allogeneic tissue before and after treatment with rabbit anti-mouse thymocyte serum (ATS) and its IgG fraction (AT-IgG). AT-IgG produced a far greater and longer lasting suppression of this reactivity in GF than in CV mice. Moreover, CV mice recovered from suppression twice as rapidly as did GF mice. In both groups, the rate of recovery was exponential. These results suggest that recovery from the suppressive effects of ATS or AT-IgG was the result of generation of new cells. Transfer of mice born and initially reared in a conventional animal room to germfree isolators, with subsequent maintenance on the same diet that the germfree mice received, did not change the reactivity of their spleen cells in the assay used nor their susceptibility to AT-IgG. Removal of GF mice to a conventional animal room resulted in a prompt reduction in susceptibility to AT-IgG. The possibility that this might be related to the elaboration of a plasma factor affecting lymphocyte stability was discussed. Spleen cells taken from GF mice at various times after such "conventionalization" showed a transient but marked hyperreactivity to tissues of the allogeneic recipients. The amount of reduction in reactivity of spleen cells from such mice treated with AT-IgG was always proportional to the activity of spleen cells from comparable untreated mice. It was suggested that the increased reactions evoked should be ascribed to an adjuvant effect rather than to specific immunologic sensitization. Blood lymphocyte counts correlated very poorly with the state of suppression, confirming previous observations. It was also shown that while AT-IgG had little or no effect on blood granulocyte counts in both GF and CV mice, marked reductions in circulating granulocytes followed administration of AT-IgG during the period of increased granulocytopoiesis that resulted from conventionalization. This demonstrated that AT-IgG can produce functional impairment of target cells other than lymphocytes

    Entanglement conditions for two-mode states: Applications

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    We examine the implications of several recently derived conditions [Hillery and Zubairy, Phys. Rev. Lett. 96, 050503 (2006)] for determining when a two-mode state is entangled. We first find examples of non-Gaussian states that satisfy these conditions. We then apply the entanglement conditions to the study of several linear devices, the beam splitter, the parametric amplifier, and the linear phase-insensitive amplifier. For the first two, we find conditions on the input states that guarantee that the output states are entangled. For the linear amplifier, we determine in the limit of high and no gain, when an entangled input leads to an entangled output. Finally, we show how application of two two-mode entanglement conditions to a three-mode state can serve as a test of genuine three-mode entanglement.Comment: 7 pages, no figures, replaced with published versio

    Sequence validation of candidates for selectively important genes in sunflower

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    Analyses aimed at identifying genes that have been targeted by past selection provide a powerful means for investigating the molecular basis of adaptive differentiation. In the case of crop plants, such studies have the potential to not only shed light on important evolutionary processes, but also to identify genes of agronomic interest. In this study, we test for evidence of positive selection at the DNA sequence level in a set of candidate genes previously identified in a genome-wide scan for genotypic evidence of selection during the evolution of cultivated sunflower. In the majority of cases, we were able to confirm the effects of selection in shaping diversity at these loci. Notably, the genes that were found to be under selection via our sequence-based analyses were devoid of variation in the cultivated sunflower gene pool. This result confirms a possible strategy for streamlining the search for adaptively-important loci process by pre-screening the derived population to identify the strongest candidates before sequencing them in the ancestral population

    AXAF user interfaces for heterogeneous analysis environments

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    The AXAF Science Center (ASC) will develop software to support all facets of data center activities and user research for the AXAF X-ray Observatory, scheduled for launch in 1999. The goal is to provide astronomers with the ability to utilize heterogeneous data analysis packages, that is, to allow astronomers to pick the best packages for doing their scientific analysis. For example, ASC software will be based on IRAF, but non-IRAF programs will be incorporated into the data system where appropriate. Additionally, it is desired to allow AXAF users to mix ASC software with their own local software. The need to support heterogeneous analysis environments is not special to the AXAF project, and therefore finding mechanisms for coordinating heterogeneous programs is an important problem for astronomical software today. The approach to solving this problem has been to develop two interfaces that allow the scientific user to run heterogeneous programs together. The first is an IRAF-compatible parameter interface that provides non-IRAF programs with IRAF's parameter handling capabilities. Included in the interface is an application programming interface to manipulate parameters from within programs, and also a set of host programs to manipulate parameters at the command line or from within scripts. The parameter interface has been implemented to support parameter storage formats other than IRAF parameter files, allowing one, for example, to access parameters that are stored in data bases. An X Windows graphical user interface called 'agcl' has been developed, layered on top of the IRAF-compatible parameter interface, that provides a standard graphical mechanism for interacting with IRAF and non-IRAF programs. Users can edit parameters and run programs for both non-IRAF programs and IRAF tasks. The agcl interface allows one to communicate with any command line environment in a transparent manner and without any changes to the original environment. For example, the authors routinely layer the GUI on top of IRAF, ksh, SMongo, and IDL. The agcl, based on the facilities of a system called Answer Garden, also has sophisticated support for examining documentation and help files, asking questions of experts, and developing a knowledge base of frequently required information. Thus, the GUI becomes a total environment for running programs, accessing information, examining documents, and finding human assistance. Because the agcl can communicate with any command-line environment, most projects can make use of it easily. New applications are continually being found for these interfaces. It is the authors' intention to evolve the GUI and its underlying parameter interface in response to these needs - from users as well as developers - throughout the astronomy community. This presentation describes the capabilities and technology of the above user interface mechanisms and tools. It also discusses the design philosophies guiding the work, as well as hopes for the future

    Major Information from a "Minor Parameter": Point of Contact in Sign Language Phonology

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    Proceedings of the Eighth Annual Meeting of the Berkeley Linguistics Society (1982

    Anticancer Photodynamic Therapy Using Ruthenium(II) and Os(II)-Based Complexes as Photosensitizers

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    Photodynamic therapy (PDT) is an approved procedure using a photosensitizer (PS) activated by light to selectively destroy malignant/premalignant cells. Transition metal complexes, such as Ru(II)- and Os(II)-based PSs (Theralase Technologies Inc., Ontario. Canada), are activated in a wide range of wavelengths, are resistant to photobleaching and have a high singlet oxygen quantum yield and ability to produce cytotoxic reactive oxygen species (ROS). Their design allows fine-tuning of the photophysical and photochemical properties. They demonstrate Type I and II photoreactions, and some are activated in hypoxia. High PDT potency and activation under NIR light and even X-ray may provide an advantage over the approved PSs. Their ability to associate with transferrin (Tf) as an endogenous delivery system increases photobleaching resistance, ROS production, selective cellular uptake, and PDT efficacy in combination with a decreased systemic toxicity. This makes these PSs attractive for systemic therapy of recurrent/progressive cancers. Their PDT efficacy has been demonstrated in various in vitro and in vivo clinically relevant models. The unique properties of the mentioned PSs allow bypassing such limitations of PDT as low specific uptake ratio, insufficiently broad absorption band, and low efficacy in hypoxia. One of these PSs (TLD-1433) was successful against non-muscle invasive urinary bladder cancer unresponsive to contemporary anticancer therapies

    Comparative genomics-based investigation of resequencing targets in Vibrio fischeri: Focus on point miscalls and artefactual expansions

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    <p>Abstract</p> <p>Background</p> <p>Sequence closure often represents the end-point of a genome project, without a system in place for subsequent improvement and refinement. Building on the genome project of <it>Vibrio fischeri </it>ES114, we used a comparative approach to identify and investigate genes that had a high likelihood of sequence error.</p> <p>Results</p> <p>Comparison of the <it>V. fischeri </it>ES114 genome with that of conspecific strain MJ11 identified 82 target loci in ES114 as containing likely errors, and thus of high-priority for resequencing. Analysis of the targets identified 75 loci in which an error had occurred, resulting in the correction of 10,457 base pairs to generate the new ES114 genomic sequence. A majority of the inaccurate loci involved frameshift errors, correction of which fused adjacent ORFs. Although insertions/deletions are thought to be rare in microbial genome assemblies, fourteen of the loci contained extraneous sequence of over 300 bp, likely due to imperfect contig ends that were misassembled in tandem rather than as overlapping segments. Additionally we updated the entire genome annotation with 113 new features including previously uncalled protein-coding genes, regulatory RNA genes and operon leader peptides, and we analyzed the transcriptional apparatus encoded by ES114.</p> <p>Conclusion</p> <p>We demonstrate that errors in microbial genome sequences, thought to largely be confined to point mutations, may also consist of other prevalent large-scale rearrangements such as insertions. Ongoing genome quality control and annotation programs are necessary to accompany technological advancements in data generation. These updates further advance <it>V. fischeri </it>as an important model for understanding intercellular communication and colonization of animal tissue.</p

    Recidivism Studied and Defined

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