126 research outputs found

    Can Internet search queries help to predict stock market volatility?

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    This paper studies the dynamics of stock market volatility and retail investor attention measured by internet search queries. We find a strong co-movement of stock market indices' realized volatility and the search queries for their names. Furthermore, Granger causality is bi-directional: high searches follow high volatility, and high volatility follows high searches. Using the latter feedback effect to predict volatility we find that search queries contain additional information about market volatility. They help to improve volatility forecasts in-sample and out-of-sample as well as for different forecasting horizons. Search queries are particularly useful to predict volatility in high-volatility phases. --realized volatility,forecasting,investor behavior,noise trader,search engine data

    Can internet search queries help to predict stock market volatility?

    Get PDF
    This paper studies the dynamics of stock market volatility and retail investor attention measured by internet search queries. We find a strong co-movement of stock market indices' realized volatility and the search queries for their names. Furthermore, Granger causality is bi-directional: high searches follow high volatility, and high volatility follows high searches. Using the latter feedback effect to predict volatility we find that search queries contain additional information about market volatility. They help to improve volatility forecasts in-sample and out-of-sample as well as for different forecasting horizons. Search queries are particularly useful to predict volatility in high-volatility phases. --realized volatility,forecasting,investor behavior,noise trader,search engine data

    Effector Glycosyltransferases in Legionella

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    Legionella causes severe pneumonia in humans. The pathogen produces an array of effectors, which interfere with host cell functions. Among them are the glucosyltransferases Lgt1, Lgt2 and Lgt3 from L. pneumophila. Lgt1 and Lgt2 are produced predominately in the post-exponential phase of bacterial growth, while synthesis of Lgt3 is induced mainly in the lag-phase before intracellular replication of bacteria starts. Lgt glucosyltransferases are structurally similar to clostridial glucosylating toxins. The enzymes use UDP–glucose as a donor substrate and modify eukaryotic elongation factor eEF1A at serine-53. This modification results in inhibition of protein synthesis and death of target cells.In addition to Lgts, Legionella genomes disclose several genes, coding for effector proteins likely to possess glycosyltransferase activities, including SetA (subversion of eukaryotic vesicle trafficking A), which influences vesicular trafficking in the yeast model system and displays tropism for late endosomal/lysosomal compartments of mammalian cells. This review mainly discusses recent results on the structure–function relationship of Lgt glucosyltransferases

    Can Internet Search Queries Help to Predict Stock Market Volatility?

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    This paper studies the dynamics of stock market volatility and retail investor attention measured by internet search queries. We find a strong co-movement of stock market indices’ realized volatility and the search queries for their names. Furthermore, Granger causality is bi-directional: high searches follow high volatility, and high volatility follows high searches. Using the latter feedback effect to predict volatility we find that search queries contain additional information about market volatility. They help to improve volatility forecasts in-sample and out-of-sample as well as for different forecasting horizons. Search queries are particularly useful to predict volatility in high-volatility phases

    Early Changes in Pain Acceptance Predict Pain Outcomes in Interdisciplinary Treatment for Chronic Pain

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    Studies have shown that pain acceptance is associated with a better pain outcome. The current study explored whether changes in pain acceptance in the very early treatment phase of an interdisciplinary cognitive-behavioral therapy (CBT)-based treatment program for chronic pain predict pain outcomes. A total of 69 patients with chronic, non-malignant pain (at least 6 months) were treated in a day-clinic for four-weeks. Pain acceptance was measured with the Chronic Pain Acceptance Questionnaire (CPAQ), pain outcomes included pain intensity (Numeric Rating Scale, NRS) as well as affective and sensory pain perception (Pain Perception Scale, SES-A and SES-S). Regression analyses controlling for the pre-treatment values of the pain outcomes, age, and gender were performed. Early changes in pain acceptance predicted pain intensity at post-treatment measured with the NRS (B = -0.04 (SE = 0.02); T = -2.28; p = 0.026), affective pain perception at post-treatment assessed with the SES-A (B = -0.26 (SE = 0.10); T = -2.79; p = 0.007), and sensory pain perception at post-treatment measured with the SES-S (B = -0.19 (SE = 0.08); T = -2.44; p = 0.017). Yet, a binary logistic regression analysis revealed that early changes in pain acceptance did not predict clinically relevant pre-post changes in pain intensity (at least 2 points on the NRS). Early changes in pain acceptance were associated with pain outcomes, however, the impact was beneath the threshold defined as clinically relevant

    Zur Person des Lehrers im Musikunterricht. Methodologische Probleme und Perspektiven zu einem Konzept offenen Musikunterrichts

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    Dieser Beitrag ist schwerpunktmäßig auf wissenschaftstheoretische und methodologische Probleme der Analyse der Lehrerperson ausgelegt. Mit dem Begriff \u27wissenschaftstheoretisch\u27 bezeichnen die Autoren in einem weiten Begriffsverständnis alle mit der Produktion und Kritik wissenschaftlicher Erkenntnis verknüpften theoretischen Fragen; der Begriff \u27methodologisch\u27 bezieht sich demgegenüber in einem engeren Sinne auf die forschungslogischen und -praktischen Probleme wissenschaftlicher Arbeit. (DIPF/Orig.

    Исследование охлаждения твердотельной мишени с помощью потока мелкодисперсно распылённой воды для производства радионуклидов I-123/I-124 на циклотроне

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    В диссертационной работе поставлена актуальная научная задача, состоящая в разработке теоретических основ технологии производства нуклидов 123I/124I с использованием нового подхода к охлаждению твердотельной мишени. Из-за низкой теплопроводности ТеО2 (30 мВт/см К), используемого в качестве материала мишени, затрудняется процесс передачи тепла от вещества мишени к охлаждаемой подложке, что приводит к снижению рабочего тока и производительности наработки нуклидов. Для решения данной задачи необходимо применять дополнительное охлаждение мишени.In the dissertation the actual scientific problem is given, which consists in development of theoretical bases of production technology of nuclides 123I/124I with the use of new approach to cooling of solid-state target. Due to low thermal conductivity of TheO2 (30 mW/cm K), used as a target material, it is difficult to transfer heat from the target material to the cooled substrate, which leads to a decrease in operating current and productivity of nuclides. To solve this problem, it is necessary to apply additional cooling of the target

    Aminoacyl-tRNA-Charged Eukaryotic Elongation Factor 1A Is the Bona Fide Substrate for Legionella pneumophila Effector Glucosyltransferases

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    Legionella pneumophila, which is the causative organism of Legionnaireś disease, translocates numerous effector proteins into the host cell cytosol by a type IV secretion system during infection. Among the most potent effector proteins of Legionella are glucosyltransferases (lgt's), which selectively modify eukaryotic elongation factor (eEF) 1A at Ser-53 in the GTP binding domain. Glucosylation results in inhibition of protein synthesis. Here we show that in vitro glucosylation of yeast and mouse eEF1A by Lgt3 in the presence of the factors Phe-tRNAPhe and GTP was enhanced 150 and 590-fold, respectively. The glucosylation of eEF1A catalyzed by Lgt1 and 2 was increased about 70-fold. By comparison of uncharged tRNA with two distinct aminoacyl-tRNAs (His-tRNAHis and Phe-tRNAPhe) we could show that aminoacylation is crucial for Lgt-catalyzed glucosylation. Aminoacyl-tRNA had no effect on the enzymatic properties of lgt's and did not enhance the glucosylation rate of eEF1A truncation mutants, consisting of the GTPase domain only or of a 5 kDa peptide covering Ser-53 of eEF1A. Furthermore, binding of aminoacyl-tRNA to eEF1A was not altered by glucosylation. Taken together, our data suggest that the ternary complex, consisting of eEF1A, aminoacyl-tRNA and GTP, is the bona fide substrate for lgt's

    Protein glutaminylation is a yeast-specific posttranslational modification of elongation factor 1A

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    Ribosomal translation factors are fundamental for protein synthesis and highly conserved in all kingdoms of life. The essential eukaryotic elongation factor 1A (eEF1A) delivers aminoacyl tRNAs to the A-site of the translating 80S ribosome. Several studies have revealed that eEF1A is posttranslationally modified. Using MS analysis, site-directed mutagenesis, and X-ray structural data analysis of Saccharomyces cerevisiae eEF1A, we identified a posttranslational modification in which the α amino group of mono-l-glutamine is covalently linked to the side chain of glutamate 45 in eEF1A. The MS analysis suggested that all eEF1A molecules are modified by this glutaminylation and that this posttranslational modification occurs at all stages of yeast growth. The mutational studies revealed that this glutaminylation is not essential for the normal functions of eEF1A in S. cerevisiae. However, eEF1A glutaminylation slightly reduced growth under antibiotic-induced translational stress conditions. Moreover, we identified the same posttranslational modification in eEF1A from Schizosaccharomyces pombe but not in various other eukaryotic organisms tested despite strict conservation of the Glu45 residue among these organisms. We therefore conclude that eEF1A glutaminylation is a yeast-specific posttranslational modification that appears to influence protein translation

    CGEF-1 regulates mTORC1 signaling during adult longevity and stress response in

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    The mechanistic target of rapamycin (mTOR) kinase is central to metabolism and growth, and has a conserved role in aging. mTOR functions in two complexes, mTORC1 and mTORC2. In diverse eukaryotes, inhibition of mTORC1 signaling increases lifespan. mTORC1 transduces anabolic signals to stimulate protein synthesis and inhibits autophagy. In this study, we demonstrate that CGEF-1, theC. eleganshomolog of the human guanine nucleotide exchange factor Dbl, is a novel binding partner of RHEB-1 and activator of mTORC1 signaling inC. elegans.cgef-1mutants display prolonged lifespan and enhanced stress resistance. The transcription factors DAF-16/FoxO and SKN-1/Nrf are required for increased longevity and stress tolerance, and induce protective gene expression incgef-1mutants. Genetic evidence indicates thatcgef-1functions in the same pathway withrheb-1, the mTOR kinaselet-363, anddaf-15/Raptor. Whencgef-1is inactivated, phosphorylation of 4E-BP, a central mTORC1 substrate for protein translation is reduced inC. elegans. Moreover, autophagy is increased uponcgef-1and mTORC1 inhibition. In addition, we show that in human cells Dbl associates with Rheb and stimulates mTORC1 downstream targets for protein synthesis suggesting that the function of CGEF-1/Dbl in the mTORC1 signaling pathway is evolutionarily conserved. These findings have important implications for mTOR functions and signaling mechanisms in aging and age-related diseases
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