20,654 research outputs found

    Asymptotic boundary forms for tight Gabor frames and lattice localization domains

    Full text link
    We consider Gabor localization operators Gϕ,ΩG_{\phi,\Omega} defined by two parameters, the generating function ϕ\phi of a tight Gabor frame {ϕλ}λΛ\{\phi_\lambda\}_{\lambda \in \Lambda}, parametrized by the elements of a given lattice ΛR2\Lambda \subset \Bbb{R}^2, i.e. a discrete cocompact subgroup of R2\Bbb{R}^2, and a lattice localization domain ΩR2\Omega \subset \Bbb{R}^2 with its boundary consisting of line segments connecting points of Λ\Lambda. We find an explicit formula for the boundary form BF(ϕ,Ω)=AΛlimRPF(Gϕ,RΩ)RBF(\phi,\Omega)=\text{A}_\Lambda \lim_{R\rightarrow \infty}\frac{PF(G_{\phi,R\Omega})}{R}, the normalized limit of the projection functional PF(Gϕ,Ω)=i=0λi(Gϕ,Ω)(1λi(Gϕ,Ω))PF(G_{\phi,\Omega})=\sum_{i=0}^{\infty}\lambda_i(G_{\phi,\Omega})(1-\lambda_i(G_{\phi,\Omega})), where λi(Gϕ,Ω)\lambda_i(G_{\phi,\Omega}) are the eigenvalues of the localization operators Gϕ,ΩG_{\phi,\Omega} applied to dilated domains RΩR\Omega, RR is an integer and AΛ\text{A}_\Lambda is the area of the fundamental domain of the lattice Λ\Lambda.Comment: 35 page

    Characteristic Energy of the Coulomb Interactions and the Pileup of States

    Get PDF
    Tunneling data on La1.28Sr1.72Mn2O7\mathrm{La_{1.28}Sr_{1.72}Mn_2O_7} crystals confirm Coulomb interaction effects through the E\sqrt{\mathrm{E}} dependence of the density of states. Importantly, the data and analysis at high energy, E, show a pileup of states: most of the states removed from near the Fermi level are found between ~40 and 130 meV, from which we infer the possibility of universal behavior. The agreement of our tunneling data with recent photoemission results further confirms our analysis.Comment: 4 pages, 4 figures, submitted to PR

    Comparison of ductile damage models during scratch tests - a numerical study

    Full text link
    The ‘wear mode diagram’ has been commonly used to classify the deformation regime of the soft work-piece during scratching, into three modes: ploughing, wedge formation and cutting. The scratch test is usedto evaluate wear modes and material removal associated with wear. There are different damage models in the literature used for the description of material behaviour after damage initiation under different loadingconditions. However, there has been little analysis to compare damage models during scratch test conditions. The first aim of this work is first to use a finite element modelling package (Abaqus/Explicit) to build a 3Dmodel to capture deformation modes during scratching with indenters with different attack angles. Three different damage models are incorporated into the model and patterns of damage initiation and propagation arecompared with experimental results from the literature. This work highlights the role of the damage model in accurately capturing wear modes and material removal during two body sliding interactions

    Novel assay to measure the plasmid mobilizing potential of mixed microbial communities

    Get PDF
    This is the final version of the article. Available from the publisher via the DOI in this record.Mobilizable plasmids lack necessary genes for complete conjugation and are therefore non-self-transmissible. Instead, they rely on the conjugation system of conjugal plasmids to be horizontally transferred to new recipients. While community permissiveness, the fraction of a mixed microbial community that can receive self-transmissible conjugal plasmids, has been studied, the intrinsic ability of a community to mobilize plasmids that lack conjugation systems is unexplored. Here, we present a novel framework and experimental method to estimate the mobilization potential of mixed communities. We compare the transfer frequency of a mobilizable plasmid to that of a mobilizing and conjugal plasmid measured for a model strain and for the assayed community. With Pseudomonas putida carrying the gfp-tagged mobilizable IncQ plasmid RSF1010 as donor strain, we conducted solid surface mating experiments with either a P. putida strain carrying the mobilizing IncP-1α plasmid RP4 or a model bacterial community that was extracted from the inner walls of a domestic shower conduit. Additionally, we estimated the permissiveness of the same community for RP4 using P. putida as donor strain. The permissiveness of the model community for RP4 [at 1.16 × 10(-4) transconjugants per recipient (T/R)] was similar to that previously measured for soil microbial communities. RSF1010 was mobilized by the model community at a frequency of 1.16 × 10(-5) T/R, only one order of magnitude lower than its permissiveness to RP4. This mobilization frequency is unexpectedly high considering that (i) mobilization requires the presence of mobilizing conjugal plasmids within the permissive fraction of the recipients; (ii) in pure culture experiments with P. putida retromobilization of RSF1010 through RP4 only took place in approximately half of the donors receiving the conjugal plasmid in the first step. Further work is needed to establish how plasmid mobilization potential varies within and across microbial communities. This method has the potential to provide such insights; in addition it allows for the direct isolation of in situ mobilizing plasmids together with their endogenous hosts.We thank L. Riber and S. J. Sørensen for access to the tagged RSF1010 plasmid, L. K. Jensen for technical assistance in the laboratory and S. M. Milani for assistance in FACS sorting. This work was funded by the Villum Kann Rasmussen Foundation Center of Excellence CREAM (Center for Environmental and Agricultural Microbiology)

    Suicide risk after bariatric surgery

    Get PDF
    Indexación: Web of Science; Scopus; Scielo.Bariatric surgery is considered the most effective treatment for severe obesity and its benefits include improvement in medical comorbidities. However, a higher rate of suicides after this type of surgery has been reported. We performed a literature review on the subject, and concluded that the mentioned increase in suicide rates, compared to the general population, is probably caused by conditions that the patient had before surgery, especially psychiatric disorders such as depression or eating disorders. These are risk factors for suicide, and are more common in the population with indication for bariatric surgery. Therefore, it is necessary to thoroughly evaluate these patients before surgery searching for suicide risk factors, deriving them to a mental health professional if necessary and follow their mental health after surgery. Considering that the literature on the topic is inconsistent, further research is needed.Bariatric surgery is considered the most effective treatment for severe obesity and its benefits include improvement in medical comorbidities. However, a higher rate of suicides after this type of surgery has been reported. We performed a literature review on the subject, and concluded that the mentioned increase in suicide rates, compared to the general population, is probably caused by conditions that the patient had before surgery, especially psychiatric disorders such as depression or eating disorders. These are risk factors for suicide, and are more common in the population with indication for bariatric surgery. Therefore, it is necessary to thoroughly evaluate these patients before surgery searching for suicide risk factors, deriving them to a mental health professional if necessary and follow their mental health after surgery. Considering that the literature on the topic is inconsistent, further research is needed.http://ref.scielo.org/58vmw

    Mangiferin: A Promising Anticancer Bioactive

    Get PDF
    Of late, several biologically active antioxidants from natural products have been investigated by the researchers in order to combat the root cause of carcinogenesis, i.e., oxidative stress. Mangiferin, a therapeutically active C-glucosylated xanthone, is extracted from pulp, peel, seed, bark and leaf of Mangifera indica. These polyphenols of mangiferin exhibit antioxidant properties and tend to decrease the oxygen-free radicals, thereby reducing the DNA damage. Indeed, its capability to modulate several key inflammatory pathways undoubtedly helps in stalling the progression of carcinogenesis. The current review article emphasizes an updated account on the patents published on the chemopreventive action of Mangiferin, apoptosis induction made on various cancer cells, along with proposed antioxidative activities and patent mapping of other important therapeutic properties. Considering it as promising polyphenol, this paper would also summarize the diverse molecular targets of Mangiferin

    An E-mail Service in a Military Adolescent Medicine Clinic: will teens use it and what for?

    Get PDF
    The goal of this study was to determine utilization patterns of an Adolescent Medicine Clinic e-mail service. An e-mail service was offered to 6134 patients presenting for care to a military Adolescent Medicine Clinic in San Antonio, Texas over a 6-month period. Families had to complete an authorization form acknowledging that the e-mail service was not encrypted and was not to be used for emergent issues prior to use. 482 families signed up for the service. A total of 42 e-mails were received from 28 of these families. 75% of all e-mails were initiated by parents. The majority of e-mails were administrative issues including: medication refills, lab follow up, and referrals requests. In conclusion, the e-mail service was a low cost method to increase communication options for our patients that was not associated with a large increase in clinic workload because of low utilization rates, especially among younger adolescents.Keywords: Adolescents; E-mail; Internet; Electronic communication; Physicianpatient communicatio

    Systèmes de production et pratiques à risque en agriculture urbaine: Cas du maraîchage dans la ville de Yamoussoukro en Côte d’Ivoire

    Get PDF
    La question de l’impact de l’agriculture urbaine sur l’environnement revient, fréquemment, au coeur des débats dans la gestion des villes africaines, comme Yamoussoukro. Les inquiétudes liées à la préservation de l’environnement urbain, eu égard à l’usage de pesticides et à la qualité des eaux utilisées, constituent une préoccupation prise en compte dans le cadre de cette étude. Celle-ci porte, aussi bien sur l’évaluation du risque sur l’environnement consécutif à de mauvaises pratiques agricoles que sur l’évaluation du risque sanitaire consécutif à l’usage des eaux usées. Pour atteindre cet objectif, la méthodologie utilisée a été d’une part, la collecte de données, à travers une enquête et d’autre part, des analyses au laboratoire. Il ressort que le maraîchage urbain à Yamoussoukro est une activité informelle. Les cultures pratiquées sont dominées par la laitue, l’oignon vert et la carotte. Le recours aux intrants, notamment les pesticides, est très répandu. Les dispositifs règlementaires sur la distribution des produits agrochimiques ne sont pas appliqués. Ainsi, 74% des pesticides recensés ne sont pas homologués pour les cultures maraîchères, 12% sont très toxiques (classe Ib) et 57% nocifs (classe II). Les risques encourus sont accentués par un traitement chimique qui n’est pas suffisamment maîtrisé. Les analyses physico-chimiques et microbiologiques ont mis en évidence, d’une part, des eaux d’irrigation aux caractéristiques très hétérogènes et d’autre part, une grande diversité microbienne et une contamination de ces eaux, suggérant des risques sanitaires avérés.Mots clés: cultures maraîchères, environnement, risque sanitaire, pesticides, eau

    Long-term manure exposure increases soil bacterial community potential for plasmid uptake.

    Get PDF
    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Microbial communities derived from soils subject to different agronomic treatments were challenged with three broad host range plasmids, RP4, pIPO2tet and pRO101, via solid surface filter matings to assess their permissiveness. Approximately 1 in 10 000 soil bacterial cells could receive and maintain the plasmids. The community permissiveness increased up to 100% in communities derived from manured soil. While the plasmid transfer frequency was significantly influenced by both the type of plasmid and the agronomic treatment, the diversity of the transconjugal pools was purely plasmid dependent and was dominated by β- and γ-Proteobacteria
    corecore