Hurwitz Actions on Reflection Factorizations in Complex Reflection Group G6

We show that in the complex reflection group G6, reflection factorizations of a Coxeter element that have the same length and multiset of conjugacy classes are in the same Hurwitz orbit. This confirms one case of a conjecture of Lewis and Reiner

Hurwitz Actions on Reflection Factorizations in Complex Reflection Group G6G_6

We show that in the complex reflection group $G_6$, reflection factorizations of a Coxeter element that have the same length and multiset of conjugacy classes are in the same Hurwitz orbit. This confirms one case of a conjecture of Lewis and Reiner.Comment: 14 page

Public policy on drug use in Morocco

L’enjeu principal de la présente thèse a pour objet de faire une analyse des paradigmes socio juridiques, en lien avec la problématisation de l’usage des drogues, ainsi que l’étude de l’interaction des facteurs individuels et politiques dans l’explication de la problématique de la délinquance liée aux drogues, au Maroc. Cette perspective tend à nous éloigner du discours sécuritaire axé sur les associations entre le phénomène de l’insécurité urbaine et l’usage de certaines substances psychoactives. La mise en avant dans les discours politico- médiatiques de cette interaction, semble être plus un argument de répression qu’une réponse efficace au phénomène étudié, et il s’agit parfois d’un raccourci qui interprète le phénomène de la délinquance de manière erronée, en ignorant l’impact des facteurs à risque psychosociaux et politiques, qui prévaut dans la dynamique de la délinquance liée aux drogues.Ces constats correspondent aux contestations des militants et des scientifiques dans plusieurs pays démocratiques, quant aux fondements de la répression de l’usage des drogues par des peines privatives de liberté et les dommages sociaux qui en découlent.La recherche documentaire, les données statistiques multi-sources et la réalisation de deux enquêtes empiriques, auprès d’un échantillon de sujets addicts et d’enfants placés sur décision judiciaire dans des centres de protection de l’enfance, ont permis de soulever que les défaillances juridiques et institutionnelles dans la gestion sociale et sanitaire de la problématique de l’addiction dans la société marocaine, et par conséquent le développement du problème social de l’usage des drogues, à partir de la décennie 1990.The main purpose of this thesis is to analyze the socio-legal paradigms related to the problematization of drug use, as well as to study the interaction of individual and political factors in explaining the problem of drug-related delinquency in Morocco. This perspective tends to distance us from the security discourse focused on the associations between the phenomenon of urban insecurity and the use of certain psychoactive substances. The emphasis in the political and media discourse on this interaction seems to be more an argument for repression than an effective response to the phenomenon studied, and it is sometimes a shortcut that interprets the phenomenon of delinquency in an erroneous manner, ignoring the impact of psychosocial and political risk factors, which prevail in the dynamics of drug-related delinquency.These findings are in line with the challenges of activists and scientists in several democratic countries, as to the basis of the repression of drug use by means of custodial sentences and the social damage that results from it.Documentary research, multi-source statistical data and the realization of two empirical surveys, with a sample of addicts and children placed by judicial decision in child protection centers, allowed to raise that the legal and institutional failures in the social and sanitary management of the problem of addiction in the Moroccan society, favored the development of the social problem of the use of drugs, from the decade of 1990, in connection with the delinquency, the overpopulation of the prisons, and the mental illness

Environmental changes at the Frasnian-Famennian boundary in Central Morocco (Northern Gondwana): integrated rock-magnetic and geochemical studies.

21 pagesRock magnetic (magnetic susceptibility and hysteresis parameters) and geochemical analyses (major and trace elements) were carried out on whole rock samples of two Frasnian–Famennian boundary sections, Anajdam and Bou-Ounebdou in the Central Morocco (Western Meseta). During the Frasnian, the decreasing trend of the magnetic susceptibility signal, mainly carried by low-coercivity magnetite grains, indicates a gradual reduction of detrital influx. This decrease in detrital input parallels a Frasnian long-term sea-level rise. In the Late Frasnian Kellwasser Horizons, that are classically considered to represent highstand deposits, the magnetic signal exhibits the lowest intensities in connection with maximum diamagnetic contribution of the carbonate fraction. With respect to geochemical data, the two black carbonate-rich Kellwasser Horizons are characterized by noticeable positive anomalies of bottom-water dysoxic proxies and of marine primary productivity markers. Our data thus suggest that in Central Morocco, the Late Frasnian marine environments were marked by a relatively important biogenic productivity favouring the onset of oxygen-depleted conditions during periods of maximum transgression on the continental platforms

A 571 million-year-old alkaline volcanic lake photosynthesizing microbial community, the Anti-atlas, Morocco

The Ediacaran period coincides with the emergence of ancestral animal lineages and cyanobacteria capable of thriving in nutrient deficient oceans which together with photosynthetic eukaryotic dominance, culminated in the rapid oxygenation of the Ediacaran atmosphere. However, ecological evidence for the colonization of the Ediacaran terrestrial biosphere by photosynthetic communities and their contribution to the oxygenation of the biosphere at this time is very sparse. Here, we expand the repertoire of Ediacaran habitable environments to a specific microbial community that thrived in an extreme alkaline volcanic lake 571 Myr ago in the Anti‐atlas of Morocco. The microbial fabrics preserve evidence of primary growth structures, comprised of two main microbialitic units, with the lower section consisting of irregular and patchy thrombolytic mesoclots associated with composite microbialitic domes. Calcirudite interbeds, dominated by wave‐rippled sandy calcarenites and stromatoclasts, fill the interdome troughs and seal the dome tops. A meter‐thick epiclastic stromatolite bed grading upwards from a dominantly flat to wavy laminated base, transitions into low convex laminae consisting of decimeter to meter‐thick dome‐shaped stromatolitic columns, overlies the thrombolitic and composite microbialitic facies. Microbialitic beds constructed during periods of limited clastic input, and underlain by coarse‐grained microbialite‐derived clasts and by the wave‐rippled calcarenites, suggest high‐energy events associated with lake expansion. High‐resolution microscopy revealed spherulitic aggregates and structures reminiscent of coccoidal microbial cell casts and mineralized extra‐polymeric substances (EPS). The primary fabrics and multistage diagenetic features, represented by active carbonate production, photosynthesizing microbial communities, photosynthetic gas bubbles, gas escape structures, and tufted mats, suggest specialized oxygenic photosynthesizers thriving in alkaline volcanic lakes, contributed toward oxygen variability in the Ediacaran terrestrial biosphere