741 research outputs found
X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2
The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position. Ă‚Â Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses
Does Basel compliance matter for bank performance?
The global financial crisis underscored the importance of regulation and supervision to a well-functioning banking system that efficiently channels financial resources into investment. In this paper, we contribute to the ongoing policy debate by assessing whether compliance with international regulatory standards and protocols enhances bank operating efficiency. We focus specifically on the adoption of international capital standards and the Basel Core Principles for Effective Bank Supervision (BCP). The relationship between bank efficiency and regulatory compliance is investigated using the Simar and Wilson (2007. J. Econ. 136 (1), 31) double bootstrapping approach on an international sample of publicly listed banks. Our results indicate that overall BCP compliance, or indeed compliance with any of its individual chapters, has no association with bank efficiency
Trigonometric Sutherland systems and their Ruijsenaars duals from symplectic reduction
Besides its usual interpretation as a system of indistinguishable
particles moving on the circle, the trigonometric Sutherland system can be
viewed alternatively as a system of distinguishable particles on the circle or
on the line, and these 3 physically distinct systems are in duality with
corresponding variants of the rational Ruijsenaars-Schneider system. We explain
that the 3 duality relations, first obtained by Ruijsenaars in 1995, arise
naturally from the Kazhdan-Kostant-Sternberg symplectic reductions of the
cotangent bundles of the group U(n) and its covering groups
and , respectively. This geometric interpretation
enhances our understanding of the duality relations and simplifies Ruijsenaars'
original direct arguments that led to their discovery.Comment: 34 pages, minor additions and corrections of typos in v
Estimation of the Coefficient of Double-Reduction in Autotetraploid Lucerne
Polyploidy plays an important role in the evolution of species and many cultivated species, particularly in angiosperms, are polyploids (Bever and Felber, 1992; Gallais, 2003). Autopolyploid species that show a tetrasomic inheritance have complex genetics. However, some theoretical models were built for: (1) genetic mapping (Hackett et al., 1998), (2) quantitative genetics (Gallais, 2003) and (3) population genetics (Ronfort et al., 1998). But in practice, most data analyses ignore one essential feature of tetrasomic inheritance that is double-reduction. Indeed, in an autotetraploid species, homologous chromosomes can form tetravalents at meiosis. In this case, a double-reduction is observed if crossing-over occurs between a locus and its centromere, and if the sister chromatids migrate to the same pole at anaphase I. The gametes may, thus, carry a pair of sister alleles. Double-reduction frequency is represented by the index of separation (α) (Demarly, 1963; Mather, 1935; Mather, 1936). The parameter α is considered as a product of four probabilities: α = q e a s (Gallais, 2003) in which “ q ” is the probability of multivalent formation, “ e ” the probability of first equational division, related to the frequency of crossing-over, “ a ” is the probability of non-disjunction at first anaphase and “s” is the probability of having two sister chromatids in the same gamete. If separation during anaphase II is random, s = ½. Consequently, α will be low for a gene located in the vicinity of the centromere and will increase with distance between the gene and the centromere. It was demonstrated that double-reduction events alter the rate of progression towards equilibrium under inbreeding or under random mating, modify the recombination rate between loci and also alter the rate of decay of linkage disequilibrium under random mating (Bever and Felber, 1992). Current theoretical models allow drawing genetic maps taking into account double-reduction (Luo et al., 2004). Thus, it is possible to estimate α for codominant loci in tetraploid species. To date, we have few estimates of the double-reduction frequency. Haynes and Douches (1993) on potato and Julier et al. (2003) on lucerne found that double-reduction occurs sporadically. In both studies, the low number of progenies hampered a precise estimation of α. The aim of our study was to estimate the frequency of double-reduction in a mapping population of lucerne that includes a large number of individuals
Bank business model migrations in Europe: determinants and effects
In response to post-crisis regulatory reforms, the European banking sector has undergone
significant changes that have led banks to reconsider their strategies, structures and
operations. Based on a sample of over 3,000 banks from 32 European countries during
the period 2010–2017, we identify banks’ business models based on cluster analysis and
track their evolution.We then apply a logistic regression and find that banks with higher
risk and lower profitability are more likely to change their business model. Employing
a propensity score matching approach, we investigate the effect of migration on bank
performance and find that changing the business model affects banks positively (i.e. migrating
banks increase their profitability, stability and cost efficiency). The effect of migration
differs depending on the target business model. When switches are a consequence
of being acquired or motivated by regulatory compliance, the positive impact remains
Evaluation des traits de vie d'une espèce endémique du Maroc (Salmo trutta macrostigma, Dumeril, 1858) dans une rivière du Moyen Atlas du Maroc: Oued Sidi Rachid
Cette étude a pour objectif la contribution à la détermination de la qualité physicochimique des eaux de l'Oued Sidi Rachid au Moyen Atlas où vit une espèce endémique du Maroc : la truite de rivière (Salmo trutta macrostigma, Duméril, 1858). L'étude des paramètres essentiels pour la vie de ce salmonidé au cours de la période comprise entre le mois de mai 2007 et le mois d'avril 2008 montre que la température, le potentiel Hydrogène (pH) et les concentrations des nitrites témoignent de la bonne qualité des eaux de l'Oued Sidi Rachid et permettent de classer ce site parmi les sites à vocation salmonicole. Les concentrations des orthophosphates sont très faibles et ne témoignent d'aucune source de pollution organique. Les concentrations des indicateurs de la dureté reflètent la nature géologique (carbonatée) de la région. Les résultats obtenus montrent bien que les eaux de l'Oued Sidi Rachid assurent à la truite de rivière un bon habitat écologique favorable à son développement et à sa reproduction.Mots clés: Qualité physicochimique, Truite de rivière, Oued Sidi Rachid, Maro
Study of adatoms diffusion through current density fluctuation functions
In this work, we investigate the diffusion process by using a mean field lattice gas dynamical model. The temporal correlation function of the current density is calculated in a probe area of radius R. The latter is considered to test if the developed formulation can be applied to reproduce STM experiments. The obtained results concerning the effective diffusion coefficient exhibit clearly the order disorder transition effect translated by two minima appearing respectively at p=1/3 and p=2/3. The effect of the ordering phase at p=1/3 requires a threshold size more precisely, the minimum size system where, the ordering phase effect begins, to appear here is R=5.In this work, we investigate the diffusion process by using a mean field lattice gas dynamical model. The temporal correlation function of the current density is calculated in a probe area of radius R. The latter is considered to test if the developed formulation can be applied to reproduce STM experiments. The obtained results concerning the effective diffusion coefficient exhibit clearly the order disorder transition effect translated by two minima appearing respectively at p=1/3 and p=2/3. The effect of the ordering phase at p=1/3 requires a threshold size more precisely, the minimum size system where, the ordering phase effect begins, to appear here is R=5
Molecular characterization of Îł gliadin from durum wheat (Triticum turgidum L. Subsp. Durum ((Desf.) Husn.)
The gluten quality is one of the main factors affecting the quality of durum wheat. It depends primarily on its storage proteins composition (glutenins and gliadins). In order to set up and initiate a technological quality improvement program of durum wheat we have conducted a prospection of the different protein sequences of gliadin in different databases for Triticum, then the filtration steps and assembly by appropriate software have been conducted to reduce the number of redundant sequences. On the other hand, we have isolated a gene from Iride "Gli-A1" encoding a Îł-gliadin protein associated with gluten strength and viscoelasticity of the dough, we performed an in silico molecular and structural analysis in order to define its putative functional properties. The latter could be a valuable candidate as molecular marker for selecting high nutritive value of durum wheat and/or for genetic improvement of durum wheat quality.Keywords: in silico; Storage Proteins; Gliadin; Triticum ; wheat; technological qualit
Contribution a l’étude physicochimique de l’écosystème lacustre Dayet Aoua au Maroc
L’étude consiste à la détermination de la qualité physicochimique des eaux du lac Dayet Aoua situé dans le Moyen Atlas au Maroc juste après son dernier desséchement survenu en été 2002. Les résultats d’analyse obtenus au cours de la période d’étude comprise entre février et juillet 2005, montrent que les eaux du lac sont bicarbonatées calciques et magnésiennes, dures à très dures. La dureté dépend essentiellement des ions magnésium. Les analyses des formes azotées et des orthophosphates des eaux du lac donnent des valeurs très faibles, et ne décèlent aucune sorte de pollution de type organique pouvant engendrer son eutrophisation, ce qui permet de le classeractuellement parmi les lacs oligotrophes.Mots-clés : lac, physico-chimie, pollution organique, oligotrophe
Perinatal-lethal Gaucher disease presenting as hydrops fetalis
Perinatal-lethal Gaucher disease is very rare and is considered a variant of type 2 Gaucher disease that occurs in the neonatal period. The most distinct features of perinatal-lethal Gaucher disease are non-immune hydrops fetalis. Less common signs of the disease are hepatosplenomegaly, ichthyosis and arthrogryposis. We report a case of Gaucher's disease (type 2) diagnosed in a newborn who presented with Hydrops Fetalis
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