Homfly Polynomials of Generalized Hopf Links

Following the recent work by T.-H. Chan in [HOMFLY polynomial of some generalized Hopf links, J. Knot Theory Ramif. 9 (2000) 865--883] on reverse string parallels of the Hopf link we give an alternative approach to finding the Homfly polynomials of these links, based on the Homfly skein of the annulus. We establish that two natural skein maps have distinct eigenvalues, answering a question raised by Chan, and use this result to calculate the Homfly polynomial of some more general reverse string satellites of the Hopf link.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol2/agt-2-2.abs.htm

Conjugacy for positive permutation braids

Positive permutation braids on n strings, which are defined to be positive n-braids where each pair of strings crosses at most once, form the elementary but non-trivial building blocks in many studies of conjugacy in the braid groups. We consider conjugacy among these elementary braids which close to knots, and show that those which close to the trivial knot or to the trefoil are all conjugate. All such n-braids with the maximum possible crossing number are also shown to be conjugate. We note that conjugacy of these braids for n<6 depends only on the crossing number. In contrast, we exhibit two such braids on 6 strings with 9 crossings which are not conjugate but whose closures are each isotopic to the (2,5) torus knot

Décès liés au monoxyde de carbone : à propos de Trois cas

L'incidence et la mortalité cumulées mondiales de l'empoisonnement au CO sont actuellement estimées à 137 cas et 4,6 décès par million. En Algérie, ce tueur silencieux, a fait 175 victimes en 2022 selon les données de la protection civil L’objectif est de faire une revue de la littérature sur l’intoxication au CO sur le plan étiologique, clinique ainsi que l'aspect analytique, de rapporter les 3 cas de décès dû au CO qui ont fait l'objet d'une enquête par le service de médecine légale de CHU Mustapha dont le dosage a été réalisée par RAPIDpoint 500ede la marque siemen

The stepwise oxidation of indolino[2,1-b]oxazolidine derivatives

This work presents an original strategy to modulate the electrochemical properties of the indolino[2,1-b]oxazolidine core appropriately substituted in position 5 (para-substitution of the phenyl ring) by acceptor or donor groups (CHO, OMe, Me, F, H, Cl, Br). Supported by spectroelectrochemical experiments and confronted to electrochemical simulations, the stepwise oxidation of indolino[2,1-b]oxazolidine derivatives involves an electrochemical mechanism which depends on the para-substitution of the phenyl ring and leads to either the formation of a stable radical cation, the opening of the oxazolidine ring or an irreversible aryl C-C coupling

Two Dimensional Fractional Supersymmetry from the Quantum Poincare Group at Roots of Unity

A group theoretical understanding of the two dimensional fractional supersymmetry is given in terms of the quantum Poincare group at roots of unity. The fractional supersymmetry algebra and the quantum group dual to it are presented and the pseudo-unitary, irreducible representations of them are obtained. The matrix elements of these representations are explicitly constructed.Comment: 10 pages. Some misprints are corrected. To appear in J. Phys.

Spatial Effects of NAO on Temperature and Precipitation Anomalies in Italy

The NAO teleconnective pattern has a great influence on the European climate; however, the exact quantification of NAO pattern in the different areas is sometimes lacking, and at other times, highlights even large differences between the various studies. This motivation led to the identification of the aim of this research in the study of the relationship between the NAO index and temperature and precipitation anomalies over the period 1991-2020, through the analysis of 87 rain gauges and 86 thermometric stations distributed as homogeneously as possible over the Italian territory. The results were sometimes at odds with the scientific literature on the subject, as significance was also found outside the winter season, e.g., in the spring for temperatures and in the autumn for precipitation, and in some cases, correlations were found, especially in August, even in southern Italy, which is usually considered a poorly correlated area. In addition, the linear relationship between the NAO index and temperature and precipitation anomalies was verified, with many weather stations obtaining significant coefficients of determinations as high as 0.5-0.6 in December, with 29 degrees of freedom, and a p-value set at 95%. Finally, for both climatic parameters, the presence of clusters and outliers at seasonal and monthly levels was assessed, obtaining a spatial distribution using the local Moran index, and summarising them in maps. This analysis highlighted important clusters in Northern and Central Italy, while clusters in the summer months occur in the South. These results provide information that may further elucidate local atmospheric dynamics in relation to NAO phases, as well as encourage future studies that may link other teleconnective indices aimed at better explaining the variance of climate parameters

The geoenvironmental factors influencing slope failures in the Majerda basin, Algerian-Tunisian border

In mountainous regions globally, landslides pose severe threats to both human lives and infrastructure, with the Mediterranean region, in particular, being highly susceptible to these destructive events that result in substantial damage to settlements and infrastructure. In this study, we employ a GIS-based approach to comprehensively characterize terrain instabilities along the Algerian-Tunisian border, recognizing the critical need for effective land planning and disaster mitigation strategies in this context. Our methodology integrates geological, geophysical, and geotechnical reconnaissance techniques and multi-criteria analysis, with a particular focus on geotechnical parameters. Our findings reveal significant slope instability within the study area; it is particularly concentrated in the mid-altitude slopes of the eastern basin, with high and very high susceptibility zones covering 20.89% of the study area. Validation of our model through ROC analysis demonstrates its high accuracy, with an area under the curve (AUC) value of 0.92. Crucially, slope gradients and precipitation emerge as key contributors to landslide occurrence, alongside Triassic lithofacies, which is a significant geological factor influencing susceptibility. These results emphasize the necessity of identifying high-landslide-susceptibility regions for sustainable land management and risk reduction, which will ultimately enhance the resilience of the studied region and mitigate the associated natural hazard risks