Global existence and asymptotic behaviour for a degenerate diffusive SEIR model

International audienceIn this paper we analyze the global existence and asymptotic behavior of a reaction diusion system with degenerate diusion arising in modeling the spatial spread of an epidemic disease

Régie des populations de Cydia pomonella (Lepidoptera : Tortricidea) dans les vergers commerciaux du Québec avec des phéromones de synthèse

Des diffuseurs à phéromones sexuelles de synthèse ont été installés en 1992 et 1993 dans trois vergers de pommiers (Malus pumila) du Québec, à raison de 1000 diffuseurs ha lors d'un essai de régie des populations de carpocapse de la pomme, Cydia pomonella [Lepidoptera : Tortricidae]. De 1991 à 1992, soit après un an d'essai, les dégâts de carpocapse à la récolte sont passés de 54 % à 32 %, de 11 % à 2 %, et se sont maintenus à 0 % dans les vergers à forte, moyenne et faible pressions de carpocapse, respectivement. Après deux ans d'essai, les dégâts sont demeurés au même niveau ou ont été diminués davantage selon le type de programme de répression utilisé contre les autres ravageurs. En 1993, une baisse de 75-100 % des captures a aussi été observée dans les pièges à phéromones par rapport aux captures observées en 1991.Pheromone dispensers were installed in 1992 and 1993, at a rate of 1000 dispensers ha1, in three Quebec apple (Malus pumila) orchards, to reduce populations of the codling moth, Cydia pomonella [Lepidoptera : Tortricidae]. After one year, codling moth damage at harvest decreased from 54% to 32%, from 11% to 2% and remained at 0% in the high, medium and low codling moth pressure orchards, respectively. Damage remained at the same level after the second year, or further decreased, depending on the type of spray program used against other pests. Pheromone trap catches in 1993 also decreased from 75 to 100% when compared to 1991 catches

Effets des anions minéraux sur la décomposition de l'ozone dans l'eau

L'influence des anions minéraux sur la décomposition de l'ozone est étudiée. Les expériences mettent en oeuvre les anions SO42-, PO43-, BO33-, SiO22-, NO3-, HCO3-+ CO32- à des concentrations identiques à celles habituellement rencontrées dans le domaine des eaux potables. Un plan d'expérience simple qui permet d'attribuer ou non une influence à chaque espèce minérale et de voir l'interaction éventuelle avec le pH est utilisé. Les manipulations sont réalisées sur un pilote de laboratoire conçu pour éliminer toutes traces de matières organiques.L'étude fait apparaître que seuls les carbonates et les bicarbonates ont une influence notable sur cette décomposition et que le pH interfère en jouant sur l'équilibre carbonates-bicarbonates. Ceci permet de vérifier l'équation théorique établie par YURTERI et GUROL (1988) en l'absence de matières organiques. L'ordre apparent de la réaction varie entre 1 et 2 : ordre 2 pour les teneurs en bicarbonates faibles (30 mg.l-1) et ordre 1 pour une teneur forte (300 mg.l-1) lorsque le pH basique déplace l'équilibre vers les carbonates. Pour 300 mg.l-1 et des pH neutres l'ordre de la réaction oscille entre 1,5 et 2. Pour un ordre 1, on peut calculer la constante d'initiation de la décomposition de l'oxydant par l'ion hydroxyle OH- (k = 80 l.mol-1 s-1).The influence of anionic mineral species on the decomposition of ozone in water was studied. The experiments involved the anions SO42-, PO43-, BO33-, SiO22-, NO3-, HCO3-+ CO32- at concentrations identical to those usually found in drinking water. The manipulations were carried out with a simple experimental procedure which allowed to determine whether or not the mineral species had an influence on this decomposition and to observe thereof the effect of the pH. A laboratory pilot made of glass and teflon, in order to eliminate any traces of organic compounds, was used.Results of this work prove that only the carbonates and bicarbonates have a notable influence on this decomposition and that the pH interferes by disrupting the bicarbonate-carbonate equilibrium. The theoretical equation established without organic compounds by YURTERI and GUROL (1988) is verified.The order of the reaction varies from 1 to 2. The order is 1 when the amount of bicarbonates is weak (30 mg/l). The order is 2 in the case of a 300 mg.l-1 concentration when the basic pH changes the equilibrium towards the carbonates. For 300 mg.l-1 concentrations and a neutral pH, the order of the reaction reaches values from 1,5 to 2. In the case of an order 1, the constant rate of the oxidant decomposition by hydroxyle ion OH¯ is calculated. Its value is 80 l.mol-1 s-1

Top to Bottom: A New Method for Assessing Adequacy of Laparoscopic Pyloromyotomy

Introduction: Hypertrophic pyloric stenosis is a commonly encountered pediatric surgical issue. Initially treated with open surgical techniques, many pediatric surgeons have adopted the minimally invasive approach using laparoscopy. However, some concerns exist that the rate of incomplete pyloromyotomy is elevated in laparoscopy. We propose a new technique to assess the adequacy of laparoscopic pyloromyotomy. Methods: Adequacy of laparoscopic pyloromyotomy was assessed by confirming that the top of the serosa on one side of the pylorus has adequate freedom to reach the bottom of the muscle on other side. A retrospective review of patients undergoing laparoscopic pyloromyotomy confirmed by this method from March 2012 to January 2016 was conducted. Demographics, laboratory values on admission, and postoperative outcomes were collected. Descriptive statistics was utilized. Results: Thirty-three patients were included. Median age was 30 days (interquartile range [IQR]: 24, 47). Median pylorus length and thickness were 19?mm (IQR 17.3, 21) and 4.5?mm (IQR: 4.0, 4.8), respectively. Median time to first full feed was 8.5 hours (IQR: 6.6, 15.6). Twenty-three (69%) patients had postoperative emesis. Median length of stay postoperation was 26.5 hours (IQR: 21.1, 44.7). There were no reoperations for incomplete pyloromyotomy and no infections. On follow-up, 1 patient had prolonged postoperative emesis that resolved without further intervention and 1 patient on peritoneal dialysis before surgery had an incisional hernia that required operation in the setting of bilateral inguinal hernias. Conclusion: In a small series, the top to bottom assessment appears to confirm adequacy of pyloromyotomy.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140155/1/lap.2016.0303.pd

Rocaglates as dual-targeting agents for experimental cerebral malaria

Cerebral malaria (CM) is a severe and rapidly progressing complication of infection by Plasmodium parasites that is associated with high rates of mortality and morbidity. Treatment options are currently few, and intervention with artemisinin (Art) has limited efficacy, a problem that is compounded by the emergence of resistance to Art in Plasmodium parasites. Rocaglates are a class of natural products derived from plants of the Aglaia genus that have been shown to interfere with eukaryotic initiation factor 4A (eIF4A), ultimately blocking initiation of protein synthesis. Here, we show that the rocaglate CR-1-31B perturbs association of Plasmodium falciparum eIF4A (PfeIF4A) with RNA. CR-1-31B shows potent prophylactic and therapeutic antiplasmodial activity in vivo in mouse models of infection with Plasmodium berghei (CM) and Plasmodium chabaudi (blood-stage malaria), and can also block replication of different clinical isolates of P. falciparum in human erythrocytes infected ex vivo, including drug-resistant P. falciparum isolates. In vivo, a single dosing of CR-1-31B in P. berghei-infected animals is sufficient to provide protection against lethality. CR-1-31B is shown to dampen expression of the early proinflammatory response in myeloid cells in vitro and dampens the inflammatory response in vivo in P. berghei-infected mice. The dual activity of CR-1-31B as an antiplasmodial and as an inhibitor of the inflammatory response in myeloid cells should prove extremely valuable for therapeutic intervention in human cases of CM.We thank Susan Gauthier, Genevieve Perreault, and Patrick Senechal for technical assistance. This work was supported by a research grant (to P.G.) from the Canadian Institutes of Health Research (CIHR) (Foundation Grant). J.P. and P.G. are supported by a James McGill Professorship salary award. D.L. is supported by fellowships from the Fonds de recherche sante Quebec, the CIHR Neuroinflammation training program. J.P. is supported by CIHR Research Grant FDN-148366. M.S. is supported by a CIHR Foundation grant. J.A.P. is supported by NIH Grant R35 GM118173. Work at the Boston University Center for Molecular Discovery is supported by Grant R24 GM111625. K.C.K. was supported by a CIHR Foundation Grant and the Canada Research Chair program. (Canadian Institutes of Health Research (CIHR); James McGill Professorship salary award; Fonds de recherche sante Quebec; CIHR Neuroinflammation training program; FDN-148366 - CIHR Research Grant; CIHR Foundation grant; R35 GM118173 - NIH; Canada Research Chair program; R24 GM111625

Well-posedness for a model of individual clustering

25 pagesInternational audienceWe study the well-posedness of a model of individual clustering. Given p > N ≥ 1 and an initial condition in W 1,p (Ω), the local existence and uniqueness of a strong solution is proved. We next consider two specific reproduction rates and show global existence if N = 1, as well as, the convergence to steady states for one of these rates

Observation of individual molecules trapped on a nanostructured insulator

For the first time, ordered polar molecules confined in monolayer-deep rectangular pits produced on an alkali halide surface by electron irradiation have been resolved at room temperature by non-contact atomic force microscopy. Molecules self-assemble in a specific fashion inside pits of width smaller than 15 nm. By contrast no ordered aggregates of molecules are observed on flat terraces. Conclusions regarding nucleation and ordering mechanisms are drawn. Trapping in pits as small as 2 nm opens a route to address single molecules

Obesity-induced insulin resistance in human skeletal muscle is characterised by defective activation of p42/p44 MAP kinase

Insulin resistance (IR), an impaired cellular, tissue and whole body response to insulin, is a major pathophysiological defect of type 2 diabetes mellitus. Although IR is closely associated with obesity, the identity of the molecular defect(s) underlying obesity-induced IR in skeletal muscle remains controversial; reduced post-receptor signalling of the insulin receptor substrate 1 (IRS1) adaptor protein and downstream effectors such as protein kinase B (PKB) have previously been implicated. We examined expression and/or activation of a number of components of the insulin-signalling cascade in skeletal muscle of 22 healthy young men (with body mass index (BMI) range, 20–37 kg/m2). Whole body insulin sensitivity (M value) and body composition was determined by the hyperinsulinaemic (40 mU. min−1.m−2.), euglycaemic clamp and by dual energy X-ray absorptiometry (DEXA) respectively. Skeletal muscle (vastus lateralis) biopsies were taken before and after one hour of hyperinsulinaemia and the muscle insulin signalling proteins examined by western blot and immunoprecipitation assay. There was a strong inverse relationship between M-value and BMI. The most striking abnormality was significantly reduced insulin-induced activation of p42/44 MAP kinase, measured by specific assay, in the volunteers with poor insulin sensitivity. However, there was no relationship between individuals' BMI or M-value and protein expression/phosphorylation of IRS1, PKB, or p42/44 MAP kinase protein, under basal or hyperinsulinaemic conditions. In the few individuals with poor insulin sensitivity but preserved p42/44 MAP kinase activation, other signalling defects were evident. These findings implicate defective p42/44 MAP kinase signalling as a potential contributor to obesity-related IR in a non-diabetic population, although clearly multiple signalling defects underlie obesity associated IR

Theory of Current and Shot Noise Spectroscopy in Single-Molecular Quantum Dots with Phonon Mode

Using the Keldysh nonequilibrium Green function technique, we study the current and shot noise spectroscopy of a single molecular quantum dot coupled to a local phonon mode. It is found that in the presence of electron-phonon coupling, in addition to the resonant peak associated with the single level of the dot, satellite peaks with the separation set by the frequency of phonon mode appear in the differential conductance. In the ``single level'' resonant tunneling region, the differential shot noise power exhibit two split peaks. However, only single peaks show up in the ``phonon assisted'' resonant-tunneling region. An experimental setup to test these predictions is also proposed.Comment: 5 pages, 3 eps figures embedde