Rapidity bin multiplicity correlations from a multi-phase transport model

The central-arbitrary bin and forward-backward bin multiplicity correlation patterns for Au+Au collisions at $\sqrt{s_{NN}}$= $7.7-62.4$ GeV are investigated within a multi-phase transport (AMPT) model. An interesting observation is that for $\sqrt{s_{NN}} <19.6$ GeV Au+Au collisions, these two correlation patterns both have an increase with the pseudorapidity gap, while for $\sqrt{s_{NN}} >19.6$ GeV Au+Au collisions, they decrease. We mainly discuss the influence of different evolution stages of collision system on the central-arbitrary bin correlations, such as the initial conditions, partonic scatterings, hadronization scheme and hadronic scatterings. Our results show that the central-arbitrary bin multiplicity correlations have different responses to partonic phase and hadronic phase, which can be suggested as a good probe to explore the dynamical evolution mechanism of the hot dense matter in high-energy heavy-ion collisions.Comment: 7pages, 6 figures, accepted for publication in EPJ

Identification and characterization of neurofibromatosis type 1 (NF1) gene mutations

La neurofibromatose 1 (NF 1) affecte un individu sur 3000 et se caractérise par l'extrême variabilité des symptôme cliniques. Le gène de NF/, situé sur le chromosome l 7q 11.2, contient 350 kb et 60 exons. Le taux de mutation est de 1 x 104/gamète/génération. Environ 50% des mutations sont d'origine familiale et 50% sporadique. Nous avons identifié et caractérisé une mutation qui cause l'exclusion des exons 11 et l 2a, six délétions et un polymorphisme HinclI et aussi déterminé le déséquilibre de liaison dans la population québécoise. Une mutation originale a été identifiée grâce au test de tronquation des protéines; elle serait la cause de l'exclusion d'exons. Le séquençage de la région génomique entre les introns 1 Oc et 12a a permis d'identifier le changement d'un G en A en position 2056+ l dans le site d' épissage 5' de l 'exon 12a. Ceci engendre l'excision des deux exons l l et 12a sans changement du cadre de lecture et sans que la quantité des ARN messagers en soit affectée. Des essais d'épissage in vivo et in vitro nous ont permis de démontrer pour la première fois que le mutation naturelle supprime la définition des exons. Nos résultats montrent aussi que la séquence encodée par les exons 11 et l 2a est essentielle pour l'activité de la neurofibromine. L 'haplotypage de 19 familles a permis de détecter la perte d'hétérozygosité (LOH) grâce aux 4 microsatellites et aux RFLPs RsaI et EcoRI. Six délétions (2 familles:76 l 0 et 74 73, et 4 patients: 178, 184, 236 et 23 7) ont été identifiées et caractérisées par la LOH et des buvardages de type Southern. La délétion dans la famille 7610 est d'origine maternelle et seul restent les exons l-4b. La délétion dans la famille 7473 est aussi d'origine maternelle et les exons de là 5 sont délétés, la délétion s'arrêtant quelque part avant l' intron 26. Avec le patient 1 78 la délétion commence entre les exons 23-2 et 27b pour se terminer après la région 3' de NFJ. La délétion dans le patient 184 commence au 5' du gène et se termine entre les exons 27b-29. La délétion dans le patient 236 commence entre les exons 14-18 et se termine après l'extrémité 3' de NFJ. Avec le patient 237, la délétion commence entre les exons 38-45 et se termine après la région 3' du gène. Ces délétions sont distribuées au hasard dans le gène NF 1.Abstract: Neurofibromatosis type 1 (NF1) afflicts 1 in 3,000 individuals and is characterized with variable clinical presentations. The NF1 gene spans 350 kb on chromosome 17q11.2 with 60 exons. The gene exhibits high mutation rate of 1 × 104/gamete/generation and approximately 50% are sporadic new mutations. In this study, a splice site mutation and 6 gross deletions have been identified and characterized. Also, a HincII polymorphism was detected and the linkage disequilibrium was investigated. Using a protein truncation assay, we have identified a exon skipping mutation. The mutation, which consists of a G to A transition at position +1 (2056+1) of the 5' splice site of exon 12a, is associated with the loss of both exons 11 and 12a in the NF1 mRNA. The mutation inactivates the 5' splice site of exon 12a, prevents exon definition and leads to the skipping of both exons 11 and 12a. These results document the first example of a natural mutation that inactivates exon definition, and suggest that the 11-12a region of NF1 plays an important role in the activity of neurofibromin. Six gross deletions (families 7610 and 7473, patients 178, 184, 236 and 236) have been identified. The breakpoint of the deletion is located between exons 5 and 26. The deletions are unique and different from those reported previously. The deletions are not associated with unusual clinical features. The HincII polymorphism is located between exons 1 and 4a as defined by probe GE2-400 bp. Three alleles are detected: A1 (3.1 and 3.3 kb), A2 (2.4 and 4.0 kb), A3 (1.3 and 5.1 kb). The detected heterozygote forms are A1-A2, or A1-A3 and the homozygote forms A1-A1 or A2-A2. Analysis haplotypes of the 19 NF1 families indicates that the four intragenic polymorphic microsatellites are strongly linked with the NF1 disease. However, no linkage disequilibrium and founder effect was observed in this Québec population collection. In conclusion, the study shows that the analysis of NF1 gene mutation is complex. No particular founder mutation has been observed in the Québec population."--Résumé abrégé par UM

Antecedents driving the different levels of behavioral engagement in online travel communities

With the rapid development of online travel communities, understanding the determinants of users ’ engagement with the online travel communities is critically important for researchers and practitioners. The purpose of this study is to understand which environmental cues drive the engagement behaviors. Specifically, by using a rich data set from a large travel knowledge sharing website and seemingly unrelated regression model, we investigate and compare the antecedents leading to two different behavioral engagements including liking and social interaction. We find that information-, source-, and social interaction-level cues are associated with these behavioral engagements. The results also demonstrate the differential effectiveness of these cues between these two engagement behaviors. Our empirical findings provide theoretical and practical implication for online travel community operators to build a vibrant and successful online travel community

Trace initial interaction from final state observable in relativistic heavy ion collisions

In order to trace the initial interaction in ultra-relativistic heavy ion collision in all azimuthal directions, two azimuthal multiplicity-correlation patterns -- neighboring and fixed-to-arbitrary angular-bin correlation patterns -- are suggested. From the simulation of Au + Au collisions at 200 GeV by using the Monte Carlo models RQMD with hadron re-scattering and AMPT with and without string melting, we observe that the correlation patterns change gradually from out-of-plane preferential one to in-plane preferential one when the centrality of collision shifts from central to peripheral, meanwhile the anisotropic collective flow v_2 keeps positive in all cases. This regularity is found to be model and collision energy independent. The physics behind the two opposite trends of correlation patterns, in particular, the presence of out-of-plane correlation patterns at RHIC energy, are discussed.Comment: 5pages, 4figure

Self-templating and in situ assembly of a cubic cluster-of-clusters architecture based on a {Mo24Fe12} inorganic macrocycle

Engineering self-templating inorganic architectures is critical for the development of bottom-up approaches to nanoscience, but systems with a hierarchy of templates are elusive. Herein we describe that the cluster-anion-templated (CAT) assembly of a {CAT}⊂{Mo24Fe12} macrocycle forms a giant ca. 220 nm3 unit cell containing 16 macrocycles clustered into eight face-shared tetrahedral cluster-of-clusters assemblies. We show that {CAT}⊂{Mo24Fe12} with different CATs gives the compounds 1–4 for CAT=Anderson {FeMo6} (1), Keggin {PMo12} (2), Dawson {P2W18} (3), and {Mo12O36(HPO3)2} (4) polyoxometalates. “Template-free” assembly can be achieved, whereby the macrocycle components can also form a template in situ allowing template to macrocycle to superstructure formation and the ability to exchange the templates. Furthermore, the transformation of template clusters within the inorganic macrocycle {Mo24Fe12} allows the self-generation of an uncapped {Mo12O36(HPO3)2} in compound 4

Triaqua­(2,2′-bipyridine N,N′-dioxide-κ2 O,O′)(5-nitro­benzene-1,3-dicarboxyl­ato-κO 1)zinc(II)

In the title compound, [Zn(C8H3NO6)(C10H8N2O2)(H2O)3], the ZnII ion is coordinated in a distorted octa­hedral geometry by three water mol­ecules, one O atom from a 5-nitro­benzene-1,3-dicarboxyl­ate ligand and two O atoms from a chelating 2,2′-bipyridine N,N′-dioxide ligand. An extensive network of O—H⋯O hydrogen bonds is formed between the water mol­ecules and the carboxyl­ate groups. C—H⋯O inter­actions are also present

On a heuristic point of view concerning the optical activity

Motivated by a recent finding that Fresnel's phenomenological description of the optical activity in the chiral medium is not self-consistent, we conduct a thorough investigation into the nature of the polarization of a plane light wave. We demonstrate that the polarization of light is the reflection of one of its quantum-mechanical properties, called the quasi-spin. Unexpectedly, the quasi-spin is not an observable with respect to the laboratory coordinate system. Instead, it is with respect to the momentum-dependent local coordinate system. The representative operators for the quasi-spin are the Pauli matrices. The wavefunction is the Jones vector. In order to completely determine a state of polarization, two different kinds of degrees of freedom are needed. One is the degrees of freedom to characterize the state of quasi-spin. They are the Stokes parameters, the expectation values of the Pauli matrices in the state described by the Jones vector. The other is the degrees of freedom to specify the local coordinate system, including the propagation direction and an angle of rotation about it. Accordingly, there are two independent mechanisms to change the state of polarization. One is to change the state of quasi-spin in a fixed local coordinate system. This is the traditional mechanism that can be expressed as an SU(2) rotation of the Jones vector. The other is to change the local coordinate system with the state of quasi-spin remaining fixed in it. At last, we show that it is the newly-identified mechanism that accounts for the optical activity.Comment: 24 page

Stokes parameters alone cannot completely characterize the polarization of plane light waves

It was generally assumed that the Stokes parameters are complete characterization for the state of polarization of a plane light wave so that their counterparts in quantum optics, called the Stokes operators, represent the polarization of photons. Here we show, through analyzing the properties of polarized plane waves in an optically active medium, that the Stokes parameters are not able to completely characterize the state of polarization of a plane wave. The key point is that only when a plane wave is expanded in terms of the orthogonal base modes, which are physically meaningful, can the two expansion coefficients make up the Jones vector. Taking this into consideration, we demonstrate that the Stokes parameters of any elliptically polarized wave in an isotropic chiral medium, determined solely by its Jones vector, are transmitted unchanged. They are not able to reflect the rotation of its polarization ellipse along with the propagation. The relationship of the Stokes parameters with the polarization of light needs further investigation.Comment: 13 page