Search results for "microscopi"
showing 10 items of 232 documents
Differential Effect of Plant Lipids on Membrane Organization
2015
SPE IPM; International audience; The high diversity of the plant lipid mixture raises the question of their respective involvement in the definition of membrane organization. This is particularly the case for plant plasma membrane, which is enriched in specific lipids, such as free and conjugated forms of phytosterols and typical phytosphingolipids, such as glycosylinositolphosphoceramides. This question was here addressed extensively by characterizing the order level of membrane from vesicles prepared using various plant lipid mixtures and labeled with an environment-sensitive probe. Fluorescence spectroscopy experiments showed that among major phytosterols, campesterol exhibits a stronger…
Long slide holders for microscope stages
2018
ABSTRACT The use of automated techniques for image analysis of microscopic wood specimens together with new procedures for the preparation of stained xylem tissue support the use of quantitative wood anatomy. These techniques and procedures are especially useful in the studies of retrospective analysis of xylem phenology, reaction(s) of trees to stressful conditions of growth, or reconstruction of long-term growth trends. The unresolved technical problems during the digitalization of cross sections from entire increment cores were stabilization and precise shifting of long microscopic specimens onto the optical microscope stage. For this reason, we have developed a long slide holder for mic…
Pistachio fruits rust caused by Tuberculina persicina (Ditmar) Sacc., anamorph of Helicobasidium purpureum (Tul.) Pat.
2020
In the study, we found rust in pistachio fruits and verified that it was caused by Tuberculina persicina, anamorph of Helicobasidium purpureum, through isolation and culture, microscopic observation, molecular identification and pathogenicity tests of Koch’s postulates. To our knowledge, this is the first report of rust fruit in pistachio caused by Tuberculina persicina.
Crowd-Averse Robust Mean-Field Games: Approximation via State Space Extension
2016
We consider a population of dynamic agents, also referred to as players. The state of each player evolves according to a linear stochastic differential equation driven by a Brownian motion and under the influence of a control and an adversarial disturbance. Every player minimizes a cost functional which involves quadratic terms on state and control plus a cross-coupling mean-field term measuring the congestion resulting from the collective behavior, which motivates the term “crowd-averse.” Motivations for this model are analyzed and discussed in three main contexts: a stock market application, a production engineering example, and a dynamic demand management problem in power systems. For th…
Two simple criteria to estimate an objective's performance when imaging in non design tissue clearing solutions
2019
Tissue clearing techniques are undergoing a renaissance motivated by the need to image fluorescent neurons, and other cells, deep in the sample without physical sectioning. Optical transparency is achieved by equilibrating tissues with high refractive index (RI) solutions. When the microscope objective is not perfectly matched to the RI of the cleared sample, aberrations are introduced. We present two simple-to-calculate numerical criteria predicting: (i) the degradation in image quality (brightness and resolution) from optimal conditions of any clearing solution/objective combination; (ii) which objective, among several available, achieves the highest resolution in a given medium. We deriv…
Increased ischemic stroke, acute coronary artery disease and mortality in patients with granulomatosis with polyangiitis and microscopic polyangiitis.
2018
International audience; Objective: The aim of our study was to assess major cardiovascular event incidence, predictors, and mortality in ANCA-associated vasculitis (AAV).Methods: We conducted a retrospective cohort study of all GPA or MPA, according to Chapel Hill Consensus Conference classification criteria, diagnosed between 1981 and 2015. Major cardiovascular event was defined as acute coronary artery disease, or ischemic stroke, or peripheral vascular disease requiring a revascularization procedure. We calculated the comparative morbidity/mortality figure (CMF) and we used Cox proportional hazards regression models to assess the risk of coronary artery disease, ischemic stroke associate…
Entropic Interactions between Two Knots on a Semiflexible Polymer.
2017
Two knots on a string can either be separated or intertwined, and may even pass through each other. At the microscopic scale, such transitions may occur spontaneously, driven by thermal fluctuations, and can be associated with a topological free energy barrier. In this manuscript, we study the respective location of a trefoil ( 3 1 ) and a figure-eight ( 4 1 ) knot on a semiflexible polymer, which is parameterized to model dsDNA in physiological conditions. Two cases are considered: first, end monomers are grafted to two confining walls of varying distance. Free energy profiles and transition barriers are then compared to a subset of free chains, which contain exactly one 3 1 and one 4 1 kn…
A topological look at human trabecular bone tissue
2017
Bone quality is affected by trabecular architecture at microscopic level. Various abnormalities of bone tissue lead to altered strength and to an increased susceptibility to fracture, such as Osteoporosis and Osteoarthritis, two major health burdens of our society. These are two complex musculoskeletal diseases that mainly concern bone tissue. In the last twenty years, there has been a growing interest in finding an appropriate topological model for the micro-architecture of trabecular bone tissue. In particular, we prove that these models involve general topological spaces. The appropriate notion to deal with is that of CW-complex.
Sural nerve biopsy studies in leigh's subacute necrotizing encephalomyelopathy
1986
Peripheral neuropathy marked by reduced nerve conduction velocities was found in four unrelated children, between the ages of 15 months and 9 years, whose autopsies revealed Leigh's subacute necrotizing encephalomyelopathy. Sural nerve biopsies disclosed primary demyelination and remyelination, as well as loss of myelinated and unmyelinated axons. The use of morphometric and electron microscopic studies shows that these techniques may reveal peripheral neuropathy in Leigh's disease more often than light microscopic methods alone.
Técnicas de microscopía para la mejora en resolución, obtención de seccionado óptico y medida cuantitativa de fase
2014
La microscopía óptica convencional alcanzó el límite en resolución que predice la difracción por medio del empleo de sofisticados objetivos de microscopio, que consiguen la captura de la información espacial en el espacio de la muestra con un ángulo de captura de prácticamente 70º en aire, esto es, aperturas numéricas (NA) de 0.9 (y mayores si existe un medio de inmersión). Existe la posibilidad de sobrepasar dicho límite o, mejor dicho, encontrar otro límite en resolución siempre que el microscopio que se emplee no pueda entenderse como un microscopio convencional. Por otro lado, los microscopios convencionales carecen de capacidad de seccionado óptico ya que, cuando se tiene una muestra t…