The bicomplex quantum Coulomb potential problem

Generalizations of the complex number system underlying the mathematical formulation of quantum mechanics have been known for some time, but the use of the commutative ring of bicomplex numbers for that purpose is relatively new. This paper provides an analytical solution of the quantum Coulomb potential problem formulated in terms of bicomplex numbers. We define the problem by introducing a bicomplex hamiltonian operator and extending the canonical commutation relations to the form [X_i,P_k] = i_1 hbar xi delta_{ik}, where xi is a bicomplex number. Following Pauli's algebraic method, we find the eigenvalues of the bicomplex hamiltonian. These eigenvalues are also obtained, along with appropriate eigenfunctions, by solving the extension of Schrodinger's time-independent differential equation. Examples of solutions are displayed. There is an orthonormal system of solutions that belongs to a bicomplex Hilbert space.Comment: Clarifications; some figures removed; version to appear in Can. J. Phy

Differential correction and preliminary orbit determination for lunar satellite orbits

Differential correction and preliminary orbit calculation for lunar satellite orbit

Les différentes approches méthodologiques de reconstitution des paléo-inondations : une revue de la littérature

Les deux dernières décennies en recherche scientifique se caractérisent par la multiplication des travaux concernant le réchauffement planétaire et les conséquences appréhendées de ce phénomène dans les divers milieux du globe. Ces travaux de recherche touchent différents champs disciplinaires dont la géomorphologie, l'hydrologie, l'écologie et bien d'autres. Dans le contexte des changements climatiques, on voit apparaître un intérêt grandissant pour l'étude des inondations anciennes ou des paléo-inondations. On tente de reconstituer la chronologie des inondations du passé notamment en regard des changements climatiques anciens ou subactuels (derniers siècles). Devant l'émergence de nombreux travaux dans ce domaine de la paléohydrologie, il nous est apparu intéressant d'examiner à travers une revue de la littérature scientifique les différentes approches méthodologiques utilisées dans l'étude des paléo-inondations. On s'attarde à décrire les principales méthodes et techniques employées dans la reconstitution des anciennes inondations, en particulier pour les environnements fluviaux (rivières, fleuves). On passe en revue les différents indicateurs biophysiques utilisés, notamment l'analyse des séquences stratigraphiques et sédimentaires, l'analyse des macrorestes, les méthodes de datation radiocarbone (14 C) et les techniques comme la thermoluminescence optique (TLO) et la dendrochronologie. Aussi, on présente les principaux modèles mathématiques utilisés dans la reconstitution des paléo-inondations, lesquels servent notamment à évaluer les variations niveaux/débits et la fréquence des inondations anciennes.The last two decades of scientific research have been characterized by an increase in the number of studies on global warming and its impact on the earth's various environments (e.g., terrestrial and aquatic ecosystems, river systems). The research concerns different fields such as geomorphology, ecology, hydrology and many others. In the context of climatic change, there is growing interest in the study of past floods or paleofloods. Researchers are attempting to reconstruct the chronology of past floods, especially with respect to past or subrecent (past centuries) climatic changes. The work involves using different methodological approaches borrowed from various disciplines including geology, geomorphology and ecology. The reconstruction of ancient hydrological events such as paleofloods in fact requires that different methods and techniques be combined in order to retrace the chronology of events as precisely as possible using different biological and physical indicators. The earliest research in this field was conducted in the United States, more specifically in the southern and southwestern parts of the country, which are regions characterized by an arid and semi-arid climate. Over the last few years, however, there have been an increasing number of studies from various parts of the world. Much of this research is based on previous work but with new elements of interpretation, which are mainly related to the many fluvial environments and climatic patterns associated with floods.A wide variety of indicators are used in the chronological reconstruction of ancient fluvial environments, whether in humid, sub-humid or desert regions. These indicators involve analyzing stratigraphic sequences and sedimentary deposits, organic matter and macrofossil deposits, as well as using radiocarbon dating (14 C), thermoluminescence (TL), and even dendrochronology. Some research uses statistical and mathematical models to evaluate river flow rates, which are transposed and adapted to ancient flood events. In fact, most of the work pertaining to the reconstruction of the frequency and magnitude of ancient floods uses several methods and techniques to obtain the long-term chronology of flood events in relation to the specific conditions (e.g. climate, geomorphology) of a region or study area.Many studies have analyzed slackwater deposits to reconstruct the paleoflood history of rivers (ELY and BAKER, 1985 ; JONES et al., 2001 ; KOCHEL and BAKER, 1982 ; WOHL et al., 1994). These kinds of deposits are mainly composed of fine-grained sediments (silt and fine sand) from river banks that were deposited during "large floods in areas of reduced flow velocity caused by ponding, eddying, or back-flooding up tributaries" (ELY and BAKER, 1985, p. 104). These deposits were found in different fluvial environments and for many researchers serve as adequate physical and geomorphologic indicators in the reconstruction of relic floods. Also, in many studies researchers used both slackwater deposits (SWD) and paleostage indicators (PSI) for the reconstruction of ancient floods. In addition to slackwater sediments, flood debris and silt lines (paleostage indicators) are often well-preserved along the river terraces (BAKER,1987; OSTENAA et al., 2002; WOHL et al., 1994) and facilitate the reconstruction of ancient flood events. The main problem in reconstructing paleofloods essentially lies in finding layers of organic matter in the sedimentary sequences, which makes it difficult to date the flood events using radiocarbon methods (14C). In arid or semi-arid environments, these organic layers are often rare because the prevalent climatic conditions do not favor the formation of a thick vegetation cover. However, this problem is not limited to these environments but also characterizes humid regions (YANG et al., 2000). The frequent absence of such organic matter layers in sediments is either due to an overly short vegetation cover formation period between phases of flooding or the erosion of such layers through the action of different natural phenomena (e.g. streaming, gliding, bioturbation, fluvial erosion). Other methods through which flood events can be dated include dendrochronology and thermoluminescence (TL). This last method can be used to obtain relatively precise dating of archaeological artefacts but at present is not very reliable for dating mineralogical samples (e.g. quartz or feldspath grains). The various problems involved in dating ancient floods make us aware of the importance of using as many physical and biological field indicators as possible in order to reconstruct the chronology of flood events as precisely as possible

Evaluating College Quarterbacks As They Enter the National Football League Draft

The National football League (NFL) in the United States has become a quarterback-centric league, where an elite quarterback is needed to win a Super Bowl. This paper will aim to provide statistical insight into how to project which college quarterback prospects will have the most successful NFL careers. We specifically focus on two quarterbacks, Jameis Winston and Marcus Mariotta, who, respectively, were the first and second choice in the first round of the NFL draft recently, in May, 2015. However, our methodology is applicable to other quarterback draftees, and, with modest adaptation, to evaluating players at other positions

Gating NO Release from Nitric Oxide Synthase

We have investigated the kinetics of NO escape from Geobacillus stearothermophilus nitric oxide synthase (gsNOS). Previous work indicated that NO release was gated at position 223 in mammalian enzymes; our kinetics experiments include mutants at that position along with measurements on the wild type enzyme. Employing stopped-flow UV–vis methods, reactions were triggered by mixing a reduced enzyme/N-hydroxy-l-arginine complex with an aerated buffer solution. NO release kinetics were obtained for wt NOS and three mutants (H134S, I223V, H134S/I223V). We have confirmed that wt gsNOS has the lowest NO release rate of known NOS enzymes, whether bacterial or mammalian. We also have found that steric clashes at positions 223 and 134 hinder NO escape, as judged by enhanced rates in the single mutants. The empirical rate of NO release from the gsNOS double mutant (H134/I223V) is nearly as rapid as that of the fastest mammalian enzymes, demonstrating that both positions 223 and 134 function as gates for escape of the product diatomic molecule

In vivo dissection of the chromosome condensation machinery: reversibility of condensation distinguishes contributions of condensin and cohesin

The machinery mediating chromosome condensation is poorly understood. To begin to dissect the in vivo function(s) of individual components, we monitored mitotic chromosome structure in mutants of condensin, cohesin, histone H3, and topoisomerase II (topo II). In budding yeast, both condensation establishment and maintenance require all of the condensin subunits, but not topo II activity or phospho-histone H3. Structural maintenance of chromosome (SMC) protein 2, as well as each of the three non-SMC proteins (Ycg1p, Ycs4p, and Brn1p), was required for chromatin binding of the condensin complex in vivo. Using reversible condensin alleles, we show that chromosome condensation does not involve an irreversible modification of condensin or chromosomes. Finally, we provide the first evidence of a mechanistic link between condensin and cohesin function. A model discussing the functional interplay between cohesin and condensin is presented

Finite-Dimensional Bicomplex Hilbert Spaces

This paper is a detailed study of finite-dimensional modules defined on bicomplex numbers. A number of results are proved on bicomplex square matrices, linear operators, orthogonal bases, self-adjoint operators and Hilbert spaces, including the spectral decomposition theorem. Applications to concepts relevant to quantum mechanics, like the evolution operator, are pointed out.Comment: 21 page

Do children unintentionally report maltreatment? Comparison of disclosures of neglect versus sexual abuse

Background and aimsChildren's initial reports often play a key role in the identification of maltreatment, and a sizeable amount of scientific research has examined how children disclose sexual and physical abuse. Although neglect constitutes a large proportion of maltreatment experiences, relatively little attention has been directed toward understanding whether and how children disclose neglect. The overarching aim of the present study was to document this process by comparing disclosure patterns in cases of neglect to those in cases of sexual abuse.MethodRedacted jurisdiction reports (N = 136) of substantiated dependency cases of neglect (n = 71) and sexual abuse (n = 65) in 4- to 17-year-olds were coded for why maltreatment was suspected, and for children's perceived awareness and disclosure of the maltreatment.ResultsNeglect was most often initially suspected via contact with emergency services (e.g., police, emergency medical services), whereas sexual abuse was most often initially suspected as a result of children's statements. Children evidenced greater perceived awareness of sexual abuse than neglect and were more likely to disclose the former in their first investigative interview. Perceived awareness was further associated with a higher likelihood of children's statements initiating discovery of maltreatment and disclosing in the first investigative interview.ConclusionsChildren may benefit from greater knowledge about their needs for safety, supervision, and provision in the home, which could increase the likelihood they would disclose neglect. Such, in turn, could lead to earlier interventions for children and families