Search results for "hypothesis"
showing 10 items of 426 documents
Statistical Analysis of the (In)efficiency of Bitcoin : A comparison of the weak form efficient market hypothesis in the US and Venezuela
2019
Master's thesis Business Administration BE501 - University of Agder 2019 Bitcoin is a phenomenon that has received a lot of attentionduringthe last years. Although the literature on the subject has expanded, there is still need for more research. This paper replicates the work of Urquhart (2016) and examines whether there isevidence ofweak form efficiency in the Bitcoin market. He found that the Bitcoin market in the US showed signs of moving towards weak form efficiency. We contribute to the existing literature by adding recentdata and comparing two different markets;the USand Venezuela. To obtain robustness of the results, the analysis is conducted by performing six different statistical …
Methylation status of VTRNA2-1/nc886 is stable across populations, monozygotic twin pairs and in majority of tissues.
2022
Aims & methods: The aim of this study was to characterize the methylation level of a polymorphically imprinted gene, VTRNA2-1/nc886, in human populations and somatic tissues.48 datasets, consisting of more than 30 tissues and >30,000 individuals, were used. Results: nc886 methylation status is associated with twin status and ethnic background, but the variation between populations is limited. Monozygotic twin pairs present concordant methylation, whereas similar to 30% of dizygotic twin pairs present discordant methylation in the nc886 locus. The methylation levels of nc886 are uniform across somatic tissues, except in cerebellum and skeletal muscle. Conclusion: The nc886 imprint may be est…
Sense-Making, Meaningfulness, and Instrumental Music Education
2020
The purpose of this paper is to re-examine the nature of "meaning" and "meaningfulness" in the context of instrumental music education. By doing so, I propose to expand the ways in which instrumental music educators conceive their mission and the ways in which we may instill meaning in people's lives. Traditionally, pursuits of philosophical deliberation have claimed that meaningfulness comes from either personal happiness (e.g., Jeremy Bentham and John Stuart Mill) or an impersonal sense of duty (e.g., St. Augustine, St. Thomas Aquinas, and Immanuel Kant). However, philosopher Wolf (2010) criticizes these positions in favor of a broader perspective, one that arises from understanding that …
Evaluation of the effect of chance correlations on variable selection using Partial Least Squares -Discriminant Analysis
2013
Variable subset selection is often mandatory in high throughput metabolomics and proteomics. However, depending on the variable to sample ratio there is a significant susceptibility of variable selection towards chance correlations. The evaluation of the predictive capabilities of PLSDA models estimated by cross-validation after feature selection provides overly optimistic results if the selection is performed on the entire set and no external validation set is available. In this work, a simulation of the statistical null hypothesis is proposed to test whether the discrimination capability of a PLSDA model after variable selection estimated by cross-validation is statistically higher than t…
Bayesian chronological analyses consistent with synchronous age of 12,835-12,735 Cal BP for Younger Dryas boundary on four continents
2015
The Younger Dryas impact hypothesis posits that a cosmic impact across much of the Northern Hemisphere deposited the Younger Dryas boundary (YDB) layer, containing peak abundances in a variable assemblage of proxies, including magnetic and glassy impact-related spherules, high-temperature minerals and melt glass, nanodiamonds, carbon spherules, aciniform carbon, platinum, and osmium. Bayesian chronological modeling was applied to 354 dates from 23 stratigraphic sections in 12 countries on four continents to establish a modeled YDB age range for this event of 12,835-12,735 Cal B.P. at 95% probability. This range overlaps that of a peak in extraterrestrial platinum in the Greenland Ice Sheet …
Analysis of an Experimental Model of In Vitro Cardiac Tissue Using Phase Space Reconstruction
2014
International audience; The in vitro cultures of cardiac cells represent valuable models to study the mechanism of the arrhythmias at the cellular level. But the dynamics of these experimental models cannot be characterized precisely, as they include a lot of parameters that depend on experimental conditions. This paper is devoted to the investigation of the dynamics of an in vitro model using a phase space reconstruction. Our model, based on the heart cells of new born rats, generates electrical field potentials acquired using a microelectrode technology, which are analyzed in normal and under external stimulation conditions. Phase space reconstructions of electrical field potential signal…
Le partage des tâches favorise la coexistence dans les communautés bactériennes dégradant l’atrazine
2019
National audience; Les communautés microbiennes exercent un rôle primordial dans la dégradation des xénobiotiques1, et en particulier des pesticides. Dans le cas de l’herbicide atrazine, plusieurs études ont démontré que sa dégradation faisait intervenir un consortium, plutôt qu’une espèce isolée2,3,4. Cependant, on ne sait pas comment la mise en place de ces consortiums dégradants se fait dans la nature. La théorie de la Reine Noire formalise les conditions nécessaires pour le mise en place de dépendance entre espèces5 : un membre de la communauté, appelé « helper », fournit un bien commun à la communauté par la dégradation d’un composé complexe, alors que les autres, appelés « beneficiari…
A multiple-response chi-square framework for the analysis of Free-Comment and Check-All-That-Apply data
2021
International audience; Free-Comment (FC) and Check-All-That-Apply (CATA) provide a contingency table containing citation counts of descriptors by products. The analyses performed on this table are most often related to the chi-square statistic. However, such practices are not well suited because they consider experimental units as being the citations (one descriptor for one product by one subject) while the evaluations (vector of citations for one product by one subject) should be considered instead. This results in incorrect expected frequencies under the null hypothesis of independence between products and descriptors and thus in an incorrect chi-square statistic. Thus, analyses related …
Unaccusativity
2012
Abstract My research is an attempt at suggesting a cross-linguistically valid definition of verbs characterized by unagentivity and affectedness such as “burn”, “die”, “sink”, “fall”, “slide”, etc., which according to the present analysis constitute the semantic core of unaccusativity. Both synchronic and diachronic approaches are followed. Various definitions have been attributed to these verbs (eventives, anticausatives, transformatives, inchoatives, decausatives). Although Perlmutter & Postal (1984) classify unaccusative verbs on the basis of their syntactic behavior, they also argue that the syntactic expression of arguments is always determinable on the basis of the meaning of the verb…
Identification of Partner Proteins of the Algae Klebsormidium nitens NO Synthases: Toward a Better Understanding of NO Signaling in Eukaryotic Photos…
2021
In animals, NO is synthesized from L-arginine by three isoforms of nitric oxide synthase (NOS) enzyme. NO production and effects have also been reported in plants but the identification of its sources, especially the enzymatic ones, remains one of the critical issues in the field. NOS-like activities have been reported, although there are no homologs of mammalian NOS in the land plant genomes sequenced so far. However, several NOS homologs have been found in algal genomes and transcriptomes. A first study has characterized a functional NOS in the chlorophyte Ostreococcus tauri and the presence of NOS homologs was later confirmed in a dozen algae. These results raise the questions of the sig…