Halogenation of SiC for band-gap engineering and excitonic functionalization

The optical excitation spectra and excitonic resonances are investigated in systematically functionalized SiC with Fluorine and/or Chlorine utilizing density functional theory in combination with many-body perturbation theory. The latter is required for a realistic description of the energy band-gaps as well as for the theoretical realization of excitons. Structural, electronic and optical properties are scrutinized and show the high stability of the predicted two-dimensional materials. Their realization in laboratory is thus possible. Huge band-gaps of the order of 4 eV are found in the so-called GW approximation, with the occurrence of bright excitons, optically active in the four investigated materials. Their binding energies vary from 0.9 eV to 1.75 eV depending on the decoration choice and in one case, a dark exciton is foreseen to exist in the fully chlorinated SiC. The wide variety of opto-electronic properties suggest halogenated SiC as interesting materials with potential not only for solar cell applications, anti-reflection coatings or high-reflective systems but also for a possible realization of excitonic Bose-Einstein condensation

Extremal Black Attractors in 8D Maximal Supergravity

Motivated by the new higher D-supergravity solutions on intersecting attractors obtained by Ferrara et al. in [Phys.Rev.D79:065031-2009], we focus in this paper on 8D maximal supergravity with moduli space [SL(3,R)/SO(3)]x[SL(2,R)/SO(2)] and study explicitly the attractor mechanism for various configurations of extremal black p- branes (anti-branes) with the typical near horizon geometries AdS_{p+2}xS^{m}xT^{6-p-m} and p=0,1,2,3,4; 2<=m<=6. Interpretations in terms of wrapped M2 and M5 branes of the 11D M-theory on 3-torus are also given. Keywords: 8D supergravity, black p-branes, attractor mechanism, M-theory.Comment: 37 page

Long-term Outcome of Hirschsprung Disease: Impact on Quality of Life and Social Condition at Adult Age

BACKGROUND: Hirschsprung disease is a rare congenital disease typically requiring surgical treatment during childhood. Quality of life and social condition at adult age can be impaired by disease-specific sequelae. OBJECTIVE: This study aimed to assess the quality of life and social outcome of adult patients operated on for Hirschsprung disease during childhood. DESIGN: Patients operated on for Hirschsprung disease during childhood were identified and specific questionnaires were sent to them. SETTINGS: Data from 2 referral centers were used. PATIENTS: Patients who completed the questionnaires regarding quality of life and social condition were included. MAIN OUTCOME MEASURES: The Hirschsprung\u27s Disease and Anorectal Malformations Quality of Life disease-specific questionnaire (8 dimensions explored; each scored from 0 to 100 maximum score) and a sociodemographic questionnaire were sent to identified patients. Sociodemographic data were compared with those of the French general population. RESULTS: Thirty-four patients had Hirschsprung disease (men, 76%; mean age, 32 years) were included in the study. Mean total Hirschsprung\u27s Disease and Anorectal Malformations Quality of Life score was 611 of 800 (maximum score 800). The 2 most impaired dimensions were "physical symptoms" and "diarrhea" (62.9/100 and 73.6/100). Fecal continence was only marginally affected (mean score, 89/100). Patients with Hirschsprung disease achieved better educational levels than the French general population. Parental and marital status did not differ between the 2 groups. LIMITATIONS: This study had the limitations inherent to a retrospective study. CONCLUSION: The quality of life of adult patients with Hirschsprung disease sequelae is marginally impaired in this study. Despite the consequences of this congenital abnormality, the condition eventually achieved can be considered as satisfactory. See Video Abstract at http://links.lww.com/DCR/A917

Dominantes pathologiques chez les caprins du Nord Marocain: cas de la région de Tétouan

Dans le but de caractériser les dominantes pathologiques des caprins dans la province de Tetouan, un suivi clinique a porté sur 13 élevages caprins de décembre 1993 à mai 1994. En plus, une étude lésionnelle macroscopique et microscopique a été réalisée sur 400 carcasses de caprins au niveau de 2 abattoirs ruraux. La fréquence de mortalité moyenne dans les élevages suivis était de 22,4% et la mortalité a touché plus les chevreaux de moins d’un mois d’âge (82,5%). Les fréquences d’avortements variaient de 5,3% à 13.3% avec une fréquence moyenne de 7,2% et affectaient beaucoup plus les chèvres primipares (60%). Les diarrhées des chevreaux ont été notées dans 38% des élevages avec une fréquence moyenne de morbidité de 22,4% et elles étaient responsables de 45% des mortalités des chevreaux. La phtiriose a été observée dans 100% des élevages avec une fréquence moyenne de morbidité de 13%. Les abcès ganglionnaires (lymphadénite caséeuse) ont été observés dans 38% des élevages. Sur les carcasses examinées à l’abattage, les broncho-pneumonies vermineuses étaient les plus fréquentes (49%) suivies des kystes hydatiques pulmonaires et/ou hépatiques (9%), des hépato-cholangites (7%) et la cysticercose hépato-péritonéale (6%). D’autres lésions comme l’ictère, l’adénomatose et la lymphdénite caséeuse ont été relevées mais avec une fréquence moindre. Au total 160 poumons (80% des organes porteurs de lésions) et 30 foies (55%) ont été saisis totalement contre 41 poumons (20%) et 22 foies (45%) saisis partiellement. Ces résultats montrent l’importance des pertes économiques dues aux problèmes pathologiques que subit l’élevage caprin de la région de Tétouan en l’absence de toute intervention technique

On Black Attractors in 8D and Heterotic/Type IIA Duality

Motivated by the study of black attractors in 8D supergravity with 16 supersymmetries, we use the field theory approach and 8D supersymmetry with non trivial central charges to shed light on the exact duality between heterotic string on T^2 and type IIA on real connected and compact surfaces {\Sigma}2. We investigate the two constraints that should be obeyed by {\Sigma}2 and give their solutions in terms of intersecting 2-cycles as well their classification using Dynkin diagrams of affine Kac-Moody algebras. It is shown as well that the moduli space of these dual theories is given by SO(1,1)x((SO(2,r+2))/(SO(2)xSO(r+2))) where r stands for the rank of the gauge symmetry G_{r} of the 10D heterotic string on T^2. The remarkable cases r=-2,-1,0 as well as other features are also investigated.Comment: LaTex, 18 pages, 2 figures, To appear in JHE

On self-sustaining processes in Rayleigh-stable rotating plane Couette flows and subcritical transition to turbulence in accretion disks

Subcritical transition to turbulence in Keplerian accretion disks is still a controversial issue and some theoretical progress is required in order to determine whether or not this scenario provides a plausible explanation for the origin of angular momentum transport in non-magnetized accretion disks. Motivated by the recent discoveries of exact nonlinear steady self-sustaining solutions in linearly stable non-rotating shear flows, we attempt to compute similar solutions in Rayleigh-stable rotating plane Couette flows and to identify transition mechanisms in such flows by combining nonlinear continuation methods and asymptotic theory. We obtain exact nonlinear solutions for Rayleigh-stable cyclonic regimes but show that it is not possible to compute solutions for Rayleigh-stable anticyclonic regimes, including Keplerian flow, using similar techniques. We also present asymptotic descriptions of these various problems at large Reynolds numbers that provide some insight into the differences between the non-rotating and Rayleigh-stable anticyclonic regimes and derive some necessary conditions for mechanisms analogous to the non-rotating self-sustaining process to be present in flows on the Rayleigh line. Our results demonstrate that subcritical transition mechanisms cannot be identified in wall-bounded Rayleigh-stable anticyclonic shear flows by transposing directly the phenomenology of subcritical transition in cyclonic and non-rotating wall-bounded shear flows. Asymptotic developments, however, leave open the possibility that nonlinear self-sustaining solutions may exist in unbounded or periodic flows on the Rayleigh line. These could serve as a starting point to discover solutions in Rayleigh-stable flows, but the nonlinear stability of Keplerian accretion disks remains to be determined.Comment: 16 pages, 12 figures. Accepted for publication in A&

Éléments d’aide au contrôle de gestion et au management de l’agrumiculture au Maroc

L’étude est dédiée aux grandes entreprises agrumicoles structurées et décentralisées. Elle fournit les éléments agronomiques et financiers pour un modèle de contrôle de gestion de type bottom-up concevable à partir de l’expérience sur la nouvelle agrumiculture née du plan Maroc Vert. Le modèle suppose la transparence, un travail en partenariat fermes-contrôle de gestion, un système d’information fiable et une fluidité de circulation de l’information. En agriculture, il n’y a pas d’analogie parfaite avec l’industrie concernant l’évaluation des écarts de performance par rapport aux objectifs de gestion affichés par le budget. Dans l’industrie, les mêmes inputs et le même process produisent en général le même résultat, ce qui facilite amplement l’analyse des écarts constatés et aide beaucoup à proposer des mesures correctives. En agriculture, avec une même quantité d’inputs (eau, engrais, pesticides), et un même process de production (porte greffe, variété, densité, taille), le résultat peut être très différent selon l’année climatique, la région ou le type de sol. Par conséquent, le plus important dans cette activité, n’est pas l’écart de performance lui-même, mais de pouvoir expliquer la part de cet écart qui revient à la gestion et celle due aux facteurs externes non maitrisables du milieu. Une contre-performance sur la productivité ou la qualité peut être la conséquence d’effets pervers d’un Chergui (chute des fruits, marbrures, coup de soleil) alors qu’aucune modification n’a été apportée au process usuel de production. De même qu’une excellente performance est parfois en partie le fait d’une année climatique favorable et d’un bon prix sur le marché et non d’un effort particulier de gestion. Cette énorme difficulté à prévoir avec une certaine confiance, ce que sera le comportement du verger d’une année à l’autre, rend donc malaisé l’usage de «&nbsp;normes&nbsp;» figées pour le contrôle de gestion. C’est pourquoi dans la présente étude, l’effort a plus porté sur l’exploration des causes des écarts autour des chiffres moyens que sur les chiffres eux-mêmes. Au Maroc, on est en présence d’un système économique libéral certes, mais la surproduction avec l’idée d’ensuite vendre les agrumes «&nbsp;a dime a dozen&nbsp;» ou de laisser la main invisible d’Adam Smith réguler le marché n’a jamais été un objectif du plan Maroc Vert. Le but recherché, est plutôt de produire pour ensuite exporter davantage afin d’améliorer la balance commerciale du pays. Aujourd’hui, on est en situation d’offre excessive en petits fruits aggravée par un Export qui peine à monter en charge, il est donc légitime que chacun cherche à tirer son épingle du jeu. Faute de pouvoir agir sur les prix, la mission basique du contrôle de gestion est donc de maîtriser au moins les charges. Même si la vraie solution pour le Maroc, aurait été plutôt d’instaurer un super-contrôle de gestion innovant de type filière avec notamment des prérogatives de gel provisoire des plantations, le temps de conquérir de nouveaux marchés. Ce que nous craignions est maintenant arrivé en 2018, c'est-à-dire finir après autant d’investissements par vendre la clémentine de qualité sur le marché local à 10cts/kg. L’étude suggère entre autres, comment sortir de cette période trouble et surmonter la crise avec un minimum de dégâts pour le producteur. Mots clés&nbsp;: Contrôle de gestion, agrumes, MarocThe study concerns the large structured and decentralized citrus fruit companies. It provides the agronomic and financial tools for management control. The present management model is based on a bottom-up design. It is inspired from the new citrus cropping experience born from the Green Morocco plan. The model assumes transparency, farm and management control partnership, reliable information system and fluidity of information. In agriculture, there is no perfect analogy with the industry sector concerning the assessment of performance gaps compared to the management objectives reported by the budget. In industry, the same inputs combined to the same process generally produce the same result. Thus, the analysis of the observed performance gaps become easier and corrective measures can be suggested. In agriculture, the result can’t be similar even the same amount of inputs (water, fertilizer, pesticides), and the same production process (rootstock, cultivar, density, pruning) have been used. This situation is related to climatic year, location and soil type. Therefore, the most important in agricultural activity, is to explain the causes of the performance gap. Then, to classify these causes into manageable factors and not manageable factors of the environment. A low performance on productivity or quality can be related to the negative effect of “Chergui” wind (fall, physical damage, sunburn, ...) even we keep the same usual production process. Also, an excellent performance is sometimes related to a very good climate year and not to a specific management effort. The enormous difficulty of predicting confidently the orchard behavior, for each year, constrains the establishment of fixed "standards" useful for management control. Thus, in the present study, we try to explore causes of deviations around average numbers. In Morocco, a liberal economy is established. However, the overproduction with the idea of selling the citrus fruit as dime a dozen or leaving the Adam Smith invisible hand regulates the market has never been the goal of the Green Morocco Plan. Such plan aims to produce and to export more in order to improve the country's trade balance. Today, we are in a situation of excessive clementine supply aggravated by the difficulty to increase export quantity. This situation pushes each producer to perform well. Regarding the difficulty to regulate prices, the basic mission of the management control is to master at least the production costs. The true solution would to introduce an innovative super-control management of citrus sector. This management would include a provisional plantation freezing waiting for finding new markets. In fact, the feared problem is occurred in 2018. Indeed, high quality clementine has been sold at 10 cts kg-1. on the local market after many investments of the producer. The study aims to give suggestions to producers on how to manage this troubled period and overcome the crisis with minimal damage. Key words: Management control, citrus fruits, Morocc

Cubeb (Piper cubeba L.): nutritional value, phytochemical profiling and dermacosmeceutical properties

IntroductionCubeb, Piper cubeba L., has been used for centuries in traditional medicine and culinary practices, with a wide range of biological and pharmacological activities.ObjectiveHerein, we determined the phytochemical profile, mineral, fatty acids, and amino acid contents of P. cubeba berries and assessed the dermacosmeceutical properties of their water extract and essential oil (EO). These included assessing their antioxidant and antibacterial activities as well as their in vitro inhibitory activities against tyrosinase and elastase enzymes. In addition, molecular docking and molecular dynamics studies were performed on the major identified compounds of the EO.Results and discussionA total of forty-three compounds belonging to organic acids, phenolic acids and flavonoids were found in the water extract, while 36 volatile compounds were identified in the EO with Z-isoeugenol, dihydroeugenol, β-pinene, E-caryophyllene, and 1,8-cineole as major constituents. The berries were found to be rich in sodium and iron, have moderate zinc content along with low contents of total nitrogen, phosphorus, and potassium. Amino acid analysis revealed a considerable concentration of isoleucine and phenylalanine, whereas 11,14,17-eicosatrienoic acid and linoleic acid were identified as the major fatty acids. In the DPPH and FRAP assays, the water extract elicited considerable antioxidant activity compared to the reference compounds. Enzyme inhibitory assays revealed that the EO had a potential to inhibit tyrosinase and elastase enzymes with IC50 values of 340.56 and 86.04 μg/mL, respectively. The water extract and EO completely inhibited the bacterial growth at MIC of 50 mg/mL and 20%, respectively. At sub-MIC concentrations, the extract and the EO substantially reduced the biofilm formation by up to 26.63 and 77.77%, respectively, as well as the swimming and swarming motilities in a dose-dependent manner. Molecular docking and molecular dynamics showed that the five main components of P. cubeba EO could be the major contributors to the elastase and tyrosinase inhibitory effect.ConclusionThis study emphasizes the promising potential of P. cubeba as a valuable source of natural compounds that can be utilized for the development of innovative pharmaceuticals, dietary supplements, and dermacosmeceutical agents