127 research outputs found

    Flight test evaluation of a method to determine the level flight performance of a propeller-driven aircraft

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    The overall drag of the aircraft is expressed in terms of the measured increment of power required to overcome a corresponding known increment of drag, which is generated by a towed drogue. The simplest form of the governing equations, D = delta D SHP/delta SHP, is such that all of the parameters on the right side of the equation can be measured in flight. An evaluation of the governing equations has been performed using data generated by flight test of a Beechcraft T-34B. The simplicity of this technique and its proven applicability to sailplanes and small aircraft is well known. However, the method fails to account for airframe-propulsion system

    Trends in DNA barcoding and metabarcoding

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    This open-access special issue features 12 full articles representing emerging trends from the international DNAbarcoding community. Several articles highlight how DNA-based techniques are elucidating the species diversity,biogeography, and conservation status of Africas biodiversity. Another prominent theme is the movementtowards big biodiversity data using high-throughput, individual-based DNA barcoding methods, which preservevoucher specimens and abundance data, as well as bulk sample-based metabarcoding. Methodological developments are enhancing the detection of specific species and whole communities using environmental DNA(eDNA) barcoding and metabarcoding. Data are also expanding in terms of genetic coverage; in this issue, a newdatabase is established for a secondary fungalDNAbarcode marker, and multi-kingdom, multi-marker biodiversitysurveys are gaining traction. DNA barcode sequence data, often combined with complementary markers or taxonomic information, are increasingly contributing to large-scale phylogenetic projects, with implications for understanding evolutionary history, community structure, and conservation priorities.Fil: Adamowicz, Sarah J.. University of Guelph; CanadáFil: Boatwright, James S.. University of The Western Cape; SudáfricaFil: Chain, Frédéric. University of Massachusetts; Estados UnidosFil: Fisher, Brian L.. California Academy Of Sciences.; Estados UnidosFil: Hogg, Ian D.. Polar Knowledge Canada; CanadáFil: Leese, Florian. Universitat Essen; AlemaniaFil: Lijtmaer, Dario Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Mwale, Monica. South African National Biodiversity Institute; SudáfricaFil: Naaum, Amanda M.. The Queens University of Belfast; IrlandaFil: Pochon, Xavier. University of Auckland; Nueva ZelandaFil: Schubert, Dirk W.. University of Guelph; CanadáFil: Wilson, John James. National Museums Liverpool; Reino UnidoFil: Wood, Susanna. Cawthron Institute; Nueva ZelandaFil: Xu, Jianping. Mcmaster University; CanadáFil: Xu, Sen. University of Texas at Arlington; Estados UnidosFil: Zhou, Xin. China Agricultural University; ChinaFil: Van Der Bank, Michelle. University of Johannesburg; Sudáfric

    Extinction Risk and Diversification Are Linked in a Plant Biodiversity Hotspot

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    Plant extinction risks in the Cape, South Africa differ from those for vertebrates worldwide, with young and fast-evolving plant lineages marching towards extinction at the fastest rate, but independently of human effects

    IRE1/bZIP60-Mediated Unfolded Protein Response Plays Distinct Roles in Plant Immunity and Abiotic Stress Responses

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    Endoplasmic reticulum (ER)-mediated protein secretion and quality control have been shown to play an important role in immune responses in both animals and plants. In mammals, the ER membrane-located IRE1 kinase/endoribonuclease, a key regulator of unfolded protein response (UPR), is required for plasma cell development to accommodate massive secretion of immunoglobulins. Plant cells can secrete the so-called pathogenesis-related (PR) proteins with antimicrobial activities upon pathogen challenge. However, whether IRE1 plays any role in plant immunity is not known. Arabidopsis thaliana has two copies of IRE1, IRE1a and IRE1b. Here, we show that both IRE1a and IRE1b are transcriptionally induced during chemically-induced ER stress, bacterial pathogen infection and treatment with the immune signal salicylic acid (SA). However, we found that IRE1a plays a predominant role in the secretion of PR proteins upon SA treatment. Consequently, the ire1a mutant plants show enhanced susceptibility to a bacterial pathogen and are deficient in establishing systemic acquired resistance (SAR), whereas ire1b is unaffected in these responses. We further demonstrate that the immune deficiency in ire1a is due to a defect in SA- and pathogen-triggered, IRE1-mediated cytoplasmic splicing of the bZIP60 mRNA, which encodes a transcription factor involved in the expression of UPR-responsive genes. Consistently, IRE1a is preferentially required for bZIP60 splicing upon pathogen infection, while IRE1b plays a major role in bZIP60 processing upon Tunicamycin (Tm)-induced stress. We also show that SA-dependent induction of UPR-responsive genes is altered in the bzip60 mutant resulting in a moderate susceptibility to a bacterial pathogen. These results indicate that the IRE1/bZIP60 branch of UPR is a part of the plant response to pathogens for which the two Arabidopsis IRE1 isoforms play only partially overlapping roles and that IRE1 has both bZIP60-dependent and bZIP60-independent functions in plant immunity

    A question of fit:cultural and individual differences in interpersonal justice perceptions

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    This study examined the link between employees’ adult attachment orientations and perceptions of line managers’ interpersonal justice behaviors, and the moderating effect of national culture (collectivism). Participants from countries categorized as low collectivistic (N = 205) and high collectivistic (N = 136) completed an online survey. Attachment anxiety and avoidance were negatively related to interpersonal justice perceptions. Cultural differences did not moderate the effects of avoidance. However, the relationship between attachment anxiety and interpersonal justice was non-significant in the Southern Asia (more collectivistic) cultural cluster. Our findings indicate the importance of ‘fit’ between cultural relational values and individual attachment orientations in shaping interpersonal justice perceptions, and highlight the need for more non-western organizational justice research
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