FD-TD numerical simulation of an entire lightning strike on the C160 aircraft

Experimental transient electromagnetic field measurements were performed on a Transall C160 aircraft during in-flight lightning strikes. The data allow a test of the predictive capabilities of a three dimensional time domain finite difference code (ALICE) developed at ONERA in order to investigate lightning-aircraft interactions. Using a transfer function technique in the 3D code, it is shown that a bi-leader attached to an aircraft can be simulated by a linear model, and so the electromagnetic fields can be calculated anywhere on the vehicle. Comparison of experimental and numerical results were made for several lightning strikes. Skin current density and electromagnetic field distributions are discussed in detail

FD-TD calculation with composite materials. Application to C160 aircraft measurements

In a frequency domain in which a material thickness is smaller than the skin depth, a formalism based on the sheet impedance concept was developed and introduced in the FD-TD (finite difference-time domain) code ALICE. The predictive capabilities of the 3D code was evaluated by comparison to analytical and experimental data. The following subject areas are covered: low frequency electromagnetic penetration of loaded apertures; FD-TD modeling; and in-flight experiment modeling

Impact of sheep grazing on juvenile sea bass, Dicentrarchus labrax L., in tidal salt marshes

The diet of young of the year sea bass, Dicentrarchus labrax L., from sheep grazed and ungrazed tidal salt marshes were com-pared qualitatively and quantitatively in Mont Saint-Michel Bay. In areas without grazing pressure, the vegetation gradient changes from a pioneer Puccinellia maritima dominated community at the tidal ¯at boundaries through a Atriplex portulacoides dominated community in the middle of the marsh to a mature Elymus pungens dominated community at the landward edge. The A. portula-coides community is highly productive and provides important quantities of litter which provides a habitat and good supply to substain high densities of the detrivorous amphipod Orchestia gammarellus. In the grazed areas, the vegetation is replaced by P. maritima communities, a low productive grass plant, and food availability and habitat suitability are reduced for O. gammarellus. Juvenile sea bass colonise the salt marsh at ¯ood during 43% of the spring tides which inundate the salt marsh creeks. They forage inside the marsh and feed mainly on O. gammarellus in the ungrazed marshes. In grazed areas, this amphipod is replaced by other species and juvenile sea bass consume less food from the marsh. This illustrates a direct effect of a terrestrial herbivore on a coastal food web, and suggests that management of salt marsh is complex and promotion of one component of their biota could involve reductions in other species

Educational needs of health professionals working in rheumatology in Europe

Objective: To explore the availability of postgraduate education for health professionals (HPs) working in rheumatology in Europe, and their perceived educational needs and barriers for participation in current educational offerings. Methods: Structured interviews were conducted with national representatives of rheumatology HPs’ organisations and an online survey among individual HPs was disseminated through existing EULAR networks (10 languages including English). These comprised questions on: availability of postgraduate education, familiarity with EULAR and its educational offerings, unmet needs regarding the contents and mode of delivery and potential barriers to participate in education (0-10 scales). Results: According to 17 national representatives, postgraduate rheumatology education was most common for nurses, physical and occupational therapists. There were 1041 individual responses to the survey, of whom 48% completed all questions. More than half (56%) were familiar with EULAR as an organisation, whereas less than 25% had attended the EULAR congress or was familiar with EULAR online courses. Educational needs regarding contents were highest for “inflammatory arthritis” and “connective tissue diseases” and regarding modes of delivery for “courses organised in own country” and “online courses”. Important barriers to participation included lack of “resources”, “time” and “English language skills”. Overall, there was considerable variation in needs and barriers among countries . Conclusions: There is a lack of postgraduate rheumatology education for HPs in most countries. There are opportunities to raise awareness regarding EULAR educational offerings and to develop courses provided in HPs’ own country, tailored to national needs and barriers and taking language barriers into consideration

Integral potential method for a transmission problem with Lipschitz interface in R^3 for the Stokes and Darcy–Forchheimer–Brinkman PDE systems

The purpose of this paper is to obtain existence and uniqueness results in weighted Sobolev spaces for transmission problems for the non-linear Darcy-Forchheimer-Brinkman system and the linear Stokes system in two complementary Lipschitz domains in R3, one of them is a bounded Lipschitz domain with connected boundary, and the other one is the exterior Lipschitz domain R3 n. We exploit a layer potential method for the Stokes and Brinkman systems combined with a fixed point theorem in order to show the desired existence and uniqueness results, whenever the given data are suitably small in some weighted Sobolev spaces and boundary Sobolev spaces

Microglial activation and chronic neurodegeneration

Microglia, the resident innate immune cells in the brain, have long been implicated in the pathology of neurode-generative diseases. Accumulating evidence points to activated microglia as a chronic source of multiple neurotoxic factors, including tumor necrosis factor-α, nitric oxide, interleukin-1β, and reactive oxygen species (ROS), driving progressive neuron damage. Microglia can become chronically activated by either a single stimulus (e.g., lipopolysaccharide or neuron damage) or multiple stimuli exposures to result in cumulative neuronal loss with time. Although the mechanisms driving these phenomena are just beginning to be understood, reactive microgliosis (the microglial response to neuron damage) and ROS have been implicated as key mechanisms of chronic and neurotoxic microglial activation, particularly in the case of Parkinson’s disease. We review the mechanisms of neurotoxicity associated with chronic microglial activation and discuss the role of neuronal death and microglial ROS driving the chronic and toxic microglial phenotype

Lethal junctional epidermolysis bullosa in heavy horses in France

Cinq cas d’épidermolyse huileuse jonctionnelle léthale ( Epitheliogenesis imperfecta ) ont été diagnostiqués au début de l’année 1989 dans deux races de cheval de trait en France. Les études anatomo-cliniques, ultra-structurales et génétiques montrent qu’il s'agit d’une affection héréditaire à déterminisme autosomal récessif analogue à l’épidermolyse huileuse jonctionnelle léithale décrite par Herlitz chez l'homme car le clivage de la jonction dermo-épidermique se situe au- dessus de la basale, au sein de la Lamina lucida. Il s’agit des premiers cas de cette maladie décrits chez le cheval en France.Five cases of junctional epidermolysis bullosa ( Epitheliogenis imper fecta) have been diagnosed since the beginning of 1989 in two draught- horse breeds in France. Anatomo-clinical, ultrastructural and genetic studies indicate that it is an hereditary disease due to an autosomal recessive gene similar to the lethal form of junctional epidermolysis bullosa descri bed by Herlitz in the child, as the cleft of the dermo-epidermal junction is located under the basal membrane, in the Lamina lucida. These are the first cases of this disease described in France in the horse