123 research outputs found

    Symmetry defects in single-gyre, wind-driven oceanic systems

    Get PDF
    We explore some symmetry properties of the leading terms that constitute the solution describing the flow field structure in a wind-driven, bottom-dissipated ocean. Both the weakly non-linear and the highly non-linear regime are investigated. The main result is that the northward displacement and the westward intensification of the current system, which are typical of the subtropical gyres (for instance the North Atlantic Ocean), can be ascribed to an interplay between the symmetries of these terms. Moreover, a duality relationship allows us to relate the conclusions concerning one regime to the other

    Induced expression of the Fragaria 7 ananassa Rapid alkalinization factor-33-like gene decreases anthracnose ontogenic resistance of unripe strawberry fruit stages

    Get PDF
    Rapid alkalinization factor (RALF) genes encode for ubiquitous small peptides that stimulate apoplastic alkalinization through interaction with malectin-like receptor kinase. RALF peptides may act as negative regulators of plant immune response, inhibiting the formation of the signal receptor complex for immune activation. Recently RALF homologues were identified in different fungal pathogen genomes contributing to host infection ability. Here, FaRALF-33-like gene expression was evaluated in strawberry fruits inoculated with Colletotrichum acutatum, Botrytis cinerea, or Penicillium expansum after 24 and 48 h post-infection. To investigate the role of FaRALF-33-like in strawberry susceptibility, transient transformation was used to overexpress it in white unripe fruits and silence it in red ripe fruits. Agroinfiltrated fruits were inoculated with C. acutatum and expression, and histological analysis of infection were performed. Silencing of FaRALF-33-like expression in C. acutatum-inoculated red fruits led to a delay in fruit colonization by the fungal pathogen, and infected tissues showed less penetrated infective hyphae than in wild-type fruits. In contrast, C. acutatum-inoculated white unripe fruits overexpressing the FaRALF-33-like gene decreased the ontogenic resistance of these fruits, leading to the appearance of disease symptoms and penetrated subcuticular hyphae, normally absent in white unripe fruits. The different response of transfected strawberry fruits to C. acutatum supports the hypothesis that the FaRALF-33-like gene plays an important role in the susceptibility of fruits to the fungal pathogen C. acutatum

    Human aging and longevity are characterized by high levels of mitokines

    Get PDF
    Mitochondrial stress elicits the production of stress response molecules indicated as mitokines, including FGF21, GDF15 and Humanin (HN). Many diseases are characterized by progressive mitochondrial dysfunction with alterations of mitokine secretion. It is still controversial whether healthy aging and extreme longevity are accompanied by altered production of mitokines. We analyzed FGF21, HN and GDF15 plasma levels in 693 subjects aged from 21 to 113 years, and the association of these mitokines with parameters of health status. FGF21, HN and GDF15 resulted increased in old age, with the highest levels found in centenarians. These molecules are associated with worsened parameters (such as handgrip strength, insulin sensitivity, total triglycerides), particularly in 70-year-old persons, and their levels are inversely correlated with survival in the oldest subjects. Considering the positive biological effect of these molecules, our results can be interpreted in the framework of the hormetic paradigm as an attempt of the cells/tissues to cope with a stress that can have beneficial or detrimental effects depending on its intensity. Finally, persons with Down Syndrome (characterized by accelerated aging) have higher levels of GDF15 and HN with respect to their siblings, suggesting that these molecules, especially GDF15, could be considered markers of biological age

    Best Practices for Cataloging Streaming Media Using RDA and MARC21

    Get PDF
    This document is intended to assist catalogers in creating records for streaming media according to instructions within Resource Description and Access (RDA), the successor to the Anglo-American Cataloguing Rules (AACR2)

    Best Practices for Cataloging Streaming Media Using RDA and MARC21

    Get PDF
    This document is intended to assist catalogers in creating records for streaming media according to instructions within Resource Description and Access (RDA), the successor to the Anglo-American Cataloguing Rules (AACR2). Like the original Best Practices for Cataloging Streaming Media, made available in 2008, it covers both streaming video and audio, including those that are born digital, as well as those that are created from an existing resource in another format, such as a video issued on DVD or videocassette. Its main focus is on resources that are “streaming” over the Internet in real-time, rather than resources that are not (e.g., video on CD-ROM or DVD-ROM, MP3 files on compact disc). In addition, it includes some examples of online video and audio files that can be downloaded in their entirety to one’s local computer

    OLAC CAPC Moving Image Work-Level Records Task Force Draft Report and Recommendations, Part I: Moving Image Work Definition and Boundaries, Part II: Core Attributes and Relationships

    Get PDF
    The Moving Image Work-Level Records Task Force of Online Audiovisual Catalogers (OLAC) Cataloging Policy Committee (CAPC) was charged with investigating and making recommendations on issues related to FRBR-based work-level records for moving image materials, including, but not limited to: Identifying characteristics of moving image works (possibly with some indication of relative importance) that should be included in work-level records and creating operational definitions of these characteristics. Identifying potential sources of information about these characteristics and examining the reliability of these sources. Examining existing bibliographic records to identify places where work-level information might be recorded and investigating the possibility of extracting information from pools of existing bibliographic records to create provisional work-level records

    OLAC CAPC Moving Image Work-Level Records Task Force Report and Recommendations, Part I: Moving Image Work Definition and Boundaries, Part II: Core Attributes and Relationships

    Get PDF
    The Moving Image Work-Level Records Task Force of Online Audiovisual Catalogers (OLAC) Cataloging Policy Committee (CAPC) was charged with investigating and making recommendations on issues related to FRBR-based work-level records for moving image materials, including, but not limited to: Identifying characteristics of moving image works (possibly with some indication of relative importance) that should be included in work-level records and creating operational definitions of these characteristics. Identifying potential sources of information about these characteristics and examining the reliability of these sources. Examining existing bibliographic records to identify places where work-level information might be recorded and investigating the possibility of extracting information from pools of existing bibliographic records to create provisional work-level records

    OLAC CAPC Moving Image Work-Level Records Task Force Final Report and Recommendations, Part IV: Extracting Work-Level Information from Existing MARC Manifestation Records

    Get PDF
    This subgroup of the Moving Image Work-Level Records Task Force of Online Audiovisual Catalogers (OLAC) Cataloging Policy Committee (CAPC) was charged with identifying places in MARC manifestation-level bibliographic records where work-level information may be encoded and examining a sample of MARC records to see how reliably this information might be extrapolated from existing records. Currently we do not have work-level records for moving images, except for a relatively small number of uniform title authority records, which usually contain only title information. Moving image uniform title authority records usually represent works, but tend to include only enough information to uniquely identify the work or expression rather than a more complete description. However, information about moving image works is often embedded in our current manifestation-level bibliographic records. If we wish to move to an environment where we create and share work-level records for moving images, it would be helpful if we could use automated means to extract data from existing bibliographic records to populate provisional work-level records. These provisional records could later be enhanced, verified and corrected by human beings. Therefore, we are interested in determining the extent to which it is possible to accurately extract work-level information from existing bibliographic records

    OLAC CAPC Moving Image Work-Level Records Task Force Final Report and Recommendations, Part IIIb: Data Sources

    Get PDF
    This second section of part three examines a number of primary and secondary sources that include information about moving images works and provides brief annotations of coverage, assessment of reliability, and a list of elements covered in each source. Print, and free and subscription online sources are included. Information about these sources is being entered into a relational database in the hope that it can be made available on the web in a flexible manner (e.g., by element covered, types of works covered, level of reliability, online vs. print)

    OLAC CAPC Moving Image Work-Level Records Task Force Final Report and Recommendations, Part IIIa: Operational Definitions: A Thought Experiment

    Get PDF
    This first section of part three examines the types of information and guidance that will be needed by catalogers in order to create, enhance, correct, and maintain work/primary expression records for moving images, which we have often referred to as work records for short
    corecore