142 research outputs found

    Phylogeography of New Zealand’s coastal benthos

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    During the past 30 years, 42 molecular studies have been undertaken in New Zealand to examine the phylogeography of coastal benthic invertebrates and plants. Here, we identify generalities and/or patterns that have emerged from this research and consider the processes implicated in generating genetic structure within populations. Studies have used various molecular markers and examined taxonomic groups with a range of life histories and dispersal strategies. Genetic disjunctions have been identified at multiple locations, with the most frequently observed division occurring between northern and southern populations at the top of the South Island. Although upwelling has been implicated as a cause of this disjunction, oceanographic evidence is lacking and alternative hypotheses exist. A significant negative correlation between larval duration and genetic differentiation (r2 = 0.39, P < 0.001, n = 29) across all studies suggests that larval duration might be used as a proxy for dispersal potential. However, among taxa with short larval durations (<10 days) there was greater variability in genetic differentiation than among taxa with longer pelagic periods. This variability implies that when larval duration is short, other factors may determine dispersal and connectivity among populations. Although there has been little congruence between the phylogeographic data and recognised biogeographic regions, recent research has resolved population subdivision at finer spatial scales corresponding more closely with existing biogeographic classifications. The use of fast-evolving and ecologically significant molecular markers in hypothesis-driven research could further improve our ability to detect population subdivision and identify the processes structuring marine ecosystems

    Oblique Shocks As The Origin Of Radio To Gamma-ray Variability In AGN

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    The `shock in jet' model for cm-waveband blazar variability is revisited, allowing for arbitrary shock orientation with respect to the jet flow direction, and both random and ordered magnetic field. It is shown that oblique shocks can explain events with swings in polarization position angle much less than the 90 deg. associated with transverse structures, while retaining the general characteristics of outbursts, including spectral behavior and level of peak percentage polarization. Models dominated by a force-free, minimum energy magnetic field configuration (essentially helical) display a shallow rise in percentage polarization and frequency dependent swing in polarization position angle not in agreement with the results of single-dish monitoring observations, implying that the field is predominantly random in the quiescent state. Outbursts well-explained by the `shock in jet' model are present during gamma-ray flaring in several sources, supporting the idea that shock events are responsible for activity from the radio to gamma-ray bands.Comment: 19 pages, 8 figures, accepted for publication in Ap

    Using Administrative Data to Explore the Effect of Survey Nonresponse in the UK Employment Retention and Advancement Demonstration

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    Background: Even a well-designed randomized control trial (RCT) study can produce ambiguous results. This paper highlights a case in which full-sample results from a large-scale RCT in the United Kingdom (UK) differ from results for a sub-sample of survey respondents. Objectives: Our objective is to ascertain the source of the discrepancy in inferences across data sources and, in doing so, to highlight important threats to the reliability of the causal conclusions derived from even the strongest research designs. Research design: The study analyzes administrative data to shed light on the source of the differences between the estimates. We explore the extent to which heterogeneous treatment impacts and survey non-response might explain these differences. We suggest checks which assess the external validity of survey measured impacts, which in turn provides an opportunity to test the effectiveness of different weighting schemes to remove bias. The Subjects included 6,787 individuals who participated in a large-scale social policy experiment. Results: Our results were not definitive but suggest non-response bias is the main source of the inconsistent findings. Conclusions. The results caution against overconfidence in drawing conclusions from RCTs and highlight the need for great care to be taken in data collection and analysis. Particularly, given the modest size of impacts expected in most RCTs, small discrepancies in data sources can alter the results. Survey data remain important as a source of information on outcomes not recorded in administrative data. However, linking survey and administrative data is strongly recommended whenever possible

    Omfördelning av Gränby Sportfälts effektuttag

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    There is currently a power shortage in the electric grid around Uppsala, which obstructs the local development, since it prevents companies from expanding their businesses. Sportfastigheter is a part of Uppsala municipality and operates the ice halls at Gränby Sportfält, which occasionally require large power outputs. The purpose of this study is, therefore, to examine whether flow batteries could be a possible technique to redistribute the power output from the electric grid. Type, size and steering of a flow battery have been examined through simulations. Flow batteries have also been compared to other energy storage methods and the implementation of a possible capacitor bank has been investigated. The result is, that flow batteries is a possible technique to cut power tops at Gränby sportfält, while other storage methods should be investigated more closely, since flow batteries is a rather new and unproven technique. If the installation would be made today, a more established storage method such as lithium ion batteries would be preferable, even though flow batteries have a promising future potential. The installation of a capacitor bank can be considered since it would compensate the reactive effect and, hence, reduce the power output at Gränby Sportfält.Det råder idag kapacitetsbrist i Uppsalas elnät vilket bromsar den lokala utvecklingen eftersom det hindrar företag från att bygga ut sina verksamheter. Sportfastigheter är en del av Uppsala kommun och förvaltar ishallarna vid Gränby Sportfält, som stundtals kräver mycket stora effektuttag. Syftet med denna studie är att undersöka om flödesbatterier kan vara en möjlig teknik för att omfördela effektuttaget från elnätet. Typ, storlek och styrning av ett flödesbatteri har undersökts genom simuleringar. Flödesbatterier har även jämförts med andra energilagringsmetoder och implementeringen av en eventuell kondensatorbank har undersökts. Resultatet är att flödesbatterier är en möjlig teknik för att kapa effekttopparna för Gränby Sportfält men att andra lagringsmetoder bör undersökas närmare, eftersom flödesbatterier är en relativt ny och obeprövad metod. Om installation skulle göras i dagsläget vore en mer etablerad lagringsmetod såsom litiumjonbatterier att föredra, även om flödesbatterier har en lovande framtidspotential. Installationen av en kondensatorbank kan övervägas då det skulle kompensera för den reaktiva effekten och på sätt minska effektuttaget för Gränby Sportfält

    SAGUARO: Time-domain Infrastructure for the Fourth Gravitational-wave Observing Run and Beyond

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    We present upgraded infrastructure for Searches after Gravitational Waves Using ARizona Observatories (SAGUARO) during LIGO, Virgo, and KAGRA's fourth gravitational-wave (GW) observing run (O4). These upgrades implement many of the lessons we learned after a comprehensive analysis of potential electromagnetic counterparts to the GWs discovered during the previous observing run. We have developed a new web-based target and observation manager (TOM) that allows us to coordinate sky surveys, vet potential counterparts, and trigger follow-up observations from one centralized portal. The TOM includes software that aggregates all publicly available information on the light curves and possible host galaxies of targets, allowing us to rule out potential contaminants like active galactic nuclei, variable stars, solar-system objects, and preexisting supernovae, as well as to assess the viability of any plausible counterparts. We have also upgraded our image-subtraction pipeline by assembling deeper reference images and training a new neural network-based real-bogus classifier. These infrastructure upgrades will aid coordination by enabling the prompt reporting of observations, discoveries, and analysis to the GW follow-up community, and put SAGUARO in an advantageous position to discover kilonovae in the remainder of O4 and beyond. Many elements of our open-source software stack have broad utility beyond multimessenger astronomy, and will be particularly relevant in the "big data" era of transient discoveries by the Vera C. Rubin Observatory.Comment: submitted to AAS Journal

    RAC1(P29S) Induces a Mesenchymal Phenotypic Switch via Serum Response Factor to Promote Melanoma Development and Therapy Resistance

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    RAC1 P29 is the third most commonly mutated codon in human cutaneous melanoma, after BRAF V600 and NRAS Q61. Here, we study the role of RAC1P29S in melanoma development and reveal that RAC1P29S activates PAK, AKT, and a gene expression program initiated by the SRF/MRTF transcriptional pathway, which results in a melanocytic to mesenchymal phenotypic switch. Mice with ubiquitous expression of RAC1P29S from the endogenous locus develop lymphoma. When expressed only in melanocytes, RAC1P29S cooperates with oncogenic BRAF or with NF1-loss to promote tumorigenesis. RAC1P29S also drives resistance to BRAF inhibitors, which is reversed by SRF/MRTF inhibitors. These findings establish RAC1P29S as a promoter of melanoma initiation and mediator of therapy resistance, while identifying SRF/MRTF as a potential therapeutic target

    Identification of a Putative Crf Splice Variant and Generation of Recombinant Antibodies for the Specific Detection of Aspergillus fumigatus

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    BACKGROUND: Aspergillus fumigatus is a common airborne fungal pathogen for humans. It frequently causes an invasive aspergillosis (IA) in immunocompromised patients with poor prognosis. Potent antifungal drugs are very expensive and cause serious adverse effects. Their correct application requires an early and specific diagnosis of IA, which is still not properly achievable. This work aims to a specific detection of A. fumigatus by immunofluorescence and the generation of recombinant antibodies for the detection of A. fumigatus by ELISA. RESULTS: The A. fumigatus antigen Crf2 was isolated from a human patient with proven IA. It is a novel variant of a group of surface proteins (Crf1, Asp f9, Asp f16) which belong to the glycosylhydrolase family. Single chain fragment variables (scFvs) were obtained by phage display from a human naive antibody gene library and an immune antibody gene library generated from a macaque immunized with recombinant Crf2. Two different selection strategies were performed and shown to influence the selection of scFvs recognizing the Crf2 antigen in its native conformation. Using these antibodies, Crf2 was localized in growing hyphae of A. fumigatus but not in spores. In addition, the antibodies allowed differentiation between A. fumigatus and related Aspergillus species or Candida albicans by immunofluorescence microscopy. The scFv antibody clones were further characterized for their affinity, the nature of their epitope, their serum stability and their detection limit of Crf2 in human serum. CONCLUSION: Crf2 and the corresponding recombinant antibodies offer a novel approach for the early diagnostics of IA caused by A. fumigatus

    Comment letters to the National Commission on Commission on Fraudulent Financial Reporting, 1987 (Treadway Commission) Vol. 1

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    https://egrove.olemiss.edu/aicpa_sop/1661/thumbnail.jp
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