157,072 research outputs found
Can social microblogging be used to forecast intraday exchange rates?
Get PDFThe Efficient Market Hypothesis (EMH) is widely accepted to hold true under
certain assumptions. One of its implications is that the prediction of stock
prices at least in the short run cannot outperform the random walk model. Yet,
recently many studies stressing the psychological and social dimension of
financial behavior have challenged the validity of the EMH. Towards this aim,
over the last few years, internet-based communication platforms and search
engines have been used to extract early indicators of social and economic
trends. Here, we used Twitter's social networking platform to model and
forecast the EUR/USD exchange rate in a high-frequency intradaily trading
scale. Using time series and trading simulations analysis, we provide some
evidence that the information provided in social microblogging platforms such
as Twitter can in certain cases enhance the forecasting efficiency regarding
the very short (intradaily) forex.Comment: This is a prior version of the paper published at NETNOMICS. The
final publication is available at
http://www.springer.com/economics/economic+theory/journal/1106
Phenolic compounds with antioxidant activity from Anthemis tinctoria L. (Asteraceae)
No full textFrom the aerial parts of Anthemis tinctoria L. subsp. tinctoria var. pallida DC. (Asteraceae), one new cyclitol glucoside, conduritol F-1-O-(6′-O-E-p-caffeoyl)-β-D-glucopyranoside (1), has been isolated together with four flavonoids, nicotiflorin (2), isoquercitrin (3), rutin (4) and patulitrin (5). The structures of the isolated compounds were established by means of NMR, MS, and UV spectral analyses. Methanolic extract and pure isolated compounds were examined for their free radical, scavenging activity, using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free stable radical, and for their inhibitory activity toward soybean lipoxygenase, using linoleic acid as substrate. Compounds 1 and 5 showed a strong scavenging effect in the DPPH radical assay. In addition 5 also exhibited high inhibitory activity on soybean lipoxygenase. © 2007 Verlag der Zeitschrift für Naturforschung
Neotectonic analysis, active stress field and active faults seismic hazard assessment in western crete
Get PDFWithin the framework of this study the complicated fault system of Western Crete was napped in detail and its kinematic and dynamic setting was analysed in order to distinguish 13 major active and possible active fault zones, the seismic potential of which was assessed. Moreover, kinematic data and striations were used to estimate the corresponding stress field geometry. Two stress phases were recognized: 1st the N-S extension phase (D1) in Mid-Upper Miocene to Lower Pliocene times forming E-W normal faults that bound the Neogene basins; 2nd the E-W extension phase (D2) in Late Pliocene-recent times forming N-S trending active normal faults. Smaller, mainly NE-SW trending faults, with significant strike-slip component, indicate a kinematic compatibility to the D2 phase, acting as transfer faults between larger N-S fault zones. The faults were incorporated in a detailed seismic hazard analysis together with the available seismological data, involving both probabilistic and deterministic approaches, for seismic hazard assessment of several selected sites (municipalities)
The actions of Caenorhabditis elegans neuropeptide-like peptides (Nlps) on body wall muscle of Ascaris suum and pharyngeal muscle of C. elegans
No full textThe actions of six Neuropeptide-like Peptides (NLPs) were investigated on Ascaris suum dorsal body wall muscle and Caenorhabditis elegans pharyngeal muscle. The NLPs tested on A. suum muscle, viz, NLP-1A, NLP-2A and B, had no direct effect on the muscle but all reversibly reduced acetylcholine (ACh)-induced contractions of the muscle, NLP-2A being the most potent, with an IC 50 value of 78 ?M. NLP-2A also reversibly reduced ACh-induced depolarizations of A. suum muscle resting membrane potential. NLP-1A, NLP-2A, NLP-3C and NLP-10A all increased pharyngeal pumping in C. elegans , NLP-8A weakly inhibited pumping while NLP-2B was inactive. NLP-10A induced a concentration-dependent increase in pumping activity with a threshold of 10–100 nM. Since genes encoding NLPs ( nlp genes) are expressed in C. elegans pharyngeal neurons it is likely these peptides play a role in feeding behaviour
Neotectonic study of the Western Crete and implications for seismic hazard assessment
Get PDFA detailed study has been realized in the framework of a large-scale seismotectonic survey in Western Crete (Southern Greece), for the creation of a revised neotectonic map in a scale of 1:50.000, including the recognition and mapping of the main neotectonic faults and the evaluation of their seismic potential. For this reason, the faults under investigation were distinguished as active, possible active and inactive. Kinematic data and striations were used to estimate the corresponding stress field geometry. Two distinctive stress phases were recognized, operating after the Middle Miocene extensional exhumation of deep crustal rocks. The first N-S extension phase (D1) took place during Mid-Upper Miocene to Lower Pliocene, forming large normal faults, trending mainly E-W, that bound the large Neogene basins. The second phase (D2) took place during late Pliocene-Quaternary times, forming medium-to-large normal faults that trend mainly N-S, related to an E-W extension. In the E-W trending D1 faults, a younger strike-slip striation usually occurs, compatible with the later D2 kinematics. Smaller, mainly NE-SW trending faults, with significant lateral displacement, indicate a kinematic compatibility to the more recent D2 phase. Some of these faults act as transfer zones between the larger N-S trending D2 faults. Considering the fault length and the using several geological criteria for their seismic risk evaluation, we recognized 13 large major fault zones in the study area, six of which were considered as active, while three as possible active faults. Results obtained from the analysis of fault plane solution information verify both the determined active (D2 phase) stress field results, as well as the local kinematic behavior of the neotectonic faulting. Moreover, a detailed seismic hazard analysis, involving both probabilistic and deterministic approaches, shows a significant spatial variation of the various hazard measures, with the seismic hazard of the westernmost part of study area being controlled by the neighboring higher seismicity neotectonic faults
O. A. C. Review Volume XLVI Issue 5, February 1934
No full textThe focus of this issue is the preparation for College Royal and recognizing its tenth anniversary. This month's agricultural article is a report from the Dominion Parasite Laboratory on the biological control of pests. Other articles provide an account of the activities of a stage manager and the development of the field of home economics at Macdonald College in Quebec. Campus news addresses the success of the 1934 Conversazione, the commemorating of the sixtieth anniversary of the founding of O. A. C., the attendance at the Canadian Author Lecture, and the successful productions of "The Apple Cart" and "Iolanthe". The Macdonald Institute column comments on the Conversat and women's athletics activities in basketball and the rifle club. The Alumni Record supplies alumni updates.EditorialTen Years of the RoyalRamblings on the RoyalBlame it on the stage managerBiological control of insect pests in CanadaNot for girls onlyCollege lifeLiterary sectionO. A. C. sportsfolioAlumni recordMacdonald newsLetters to the editoradvertisin
O. A. C. Review Volume XXXVI Issue 12, August 1924
No full textThis slim summer issue contains the address given by the agricultural section of the British Association for the Advancement of Science, and a report on the visit of this association to the O. A. C. Other articles include instructions on increasing strawberry production and a biography of the author John Masefield. The editorial comments on Rhodes Scholars. The Alumni column provides an update of alumni activities. This issue does not contain a Macdonald column.JoyPresent-day problems in crop productionAfter the strawberry harvestJohn MasefieldVisit of the Agricultural Section of the British Association for the Advancement of ScienceEditorialCollege lifeAlumniadvertisin
Attention and neurocognition
No full textEssig K, Janelle C, Borgo F, Koester D. Attention and neurocognition. In: Papaioannou AG, Hackfort D, eds. Routledge Companion to Sport and Exercise Psychology : Global perspectives and fundamental concepts. International perspectives on key issues in sport and exercise psychology. London: Routledge; 2014: 253--271
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Elements and Construction of Motor Control
No full textSchack T, Bläsing B, Hughes C, Flash T, Schilling M. Elements and Construction of Motor Control. In: Papaioannou A, Hackfort D, eds. Routledge Companion to Sport and Exercise Psychology:Global Perspectives and Fundamental Concepts. Routledge, London; 2014: 306-321
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