128 research outputs found
Construction of nacelle power-curve following Markov's theory
The standard procedure to constuct a power curve is the lEC standard. However, this model contains some flaws. In fact, by averaging the power inside a bin speed the power obtained isn't precise, since the power is directly affected by the turbulence intensity of the wind speed. Moreover, it requires long time to evaluate the influence of different settings with this method. The solution proposed in this thesis is to implement a novel method to construct a power curve, which is by following the Markov's theory. This method calculates the stationary power with a stochastic approach, which is more precise and should take less time than the standard procedure. Nonetheless, the construction of a power curve with the meteorological-mast (MM) anemometer isn't always feasible. In addition, the distance between the MM and the turbine can reduce the correlation of the wind speed read at the MM anemometer and the one which hit the blades of the turbine. Thus, to correct that, the construction of the power curve should be implemented on the nacelle anemometer.
The final objective of this master thesis is to implement a Markov power-curve program, which will calculate the stationary power with the nacelle anemometer at each speed bin. Furthermore, this thesis will evaluate and optimise the parameters to obtain the best power curve following this novel method. Finally, the evaluation of the measurement time required to construct this type of power curve will be executed.
Albeit the power curves obtained following this new method aren't stable, this thesis proposes the median to calculate the conditional moment, since the results are less affected by the turbulence intensity. Besides, it also proposes to average the wind speed over a period of two minutes, when using the nacelle anemometer, to eliminate the fast fluctuations of the wind speed due to the blade passage. Moreover, the utilisation of the data averaged over different periods of time doesn't change the result of the power curve. However, the time required to construct a Markov power-curve isn't affected by the averaging time of the data. Nevertheless, this novel method is a little bit faster than the lEC procedure.
Further improvement should be done in the power-curve program. The software amelioration should make the results more stable and more accurate. In addition, the required time to construct a Markov power-curve might decrease again. The first recommendation is to verify with more data sets the rotor-position filter effect, when using the nacelle anemometer to construct a Markov power-curve. The second recommendation could be to correct the second minimum problem when calculating the stationary power with the minimal potential. A method to correct that will be to optimize the relaxation-time interval to determine the drift
Linear Efficient Antialiased Displacement and Reflectance Mapping
International audienceWe present Linear Efficient Antialiased Displacement and Reflectance (LEADR) mapping, a reflectance filtering technique for displacement mapped surfaces. Similarly to LEAN mapping, it employs two mipmapped texture maps, which store the first two moments of the displacement gradients. During rendering, the projection of this data over a pixel is used to compute a noncentered anisotropic Beckmann distribution using only simple, linear filtering operations. The distribution is then injected in a new, physically based, rough surface microfacet BRDF model, that includes masking and shadowing effects for both diffuse and specular reflection under directional, point, and environment lighting. Furthermore, our method is compatible with animation and deformation, making it extremely general and flexible. Combined with an adaptive meshing scheme, LEADR mapping provides the very first seamless and hardware-accelerated multi-resolution representation for surfaces. In order to demonstrate its effectiveness, we render highly detailed production models in real time on a commodity GPU, with quality matching supersampled ground-truth images
Phase 2B randomized study of nemolizumab in adults with moderate-to-severe atopic dermatitis and severe pruritus
Background: Nemolizumab targets the IL-31 receptor a subunit
involved in atopic dermatitis (AD) pathogenesis.
Objective: We sought to evaluate a new dosing strategy of
nemolizumab in patients with AD.
Methods: We performed a 24-week, randomized, double-blind,
multicenter study of nemolizumab (10, 30, and 90 mg)
subcutaneous injections every 4 weeks versus placebo, with
topical corticosteroids in adults with moderate-to-severe AD,
severe pruritus, and inadequate control with topical treatment
(n 5 226). The Eczema Area and Severity Index (EASI), the
peak pruritus (PP) numeric rating scale (NRS), and the
Investigator’s Global Assessment (IGA) were assessed. Standard
safety assessments were performed.
Results: Nemolizumab improved EASI, IGA, and/or NRS-itch
scores, with the 30-mg dose being most effective.
Nemolizumab (30 mg) reduced EASI scores versus placebo at
week 24 (268.8% vs 252.1%, P 5 .016); significant
differences were observed by week 8 (P <_ .01). With significant
improvement (P 5 .028) as early as week 4, IGA 0/1 rates
were higher for 30 mg of nemolizumab versus placebo at week
16 (33.3% vs 12.3%, P 5 .008) but not week 24 because of an
increased placebo/topical corticosteroid effect (36.8% vs
21.1%, P 5 .06). PP-NRS scores were improved for 30 mg of
nemolizumab versus placebo at week 16 (268.6% vs 234.3%,
P <.0001) and week 24 (267.3% vs 235.8%, P <.0001), with a
difference by week 1 (P _4-point
decrease) were greater for 30 mg of nemolizumab versus
placebo at week 16 (P <_ .001) and week 24 (P <_ .01).
Nemolizumab was safe and well tolerated. The most common
adverse events were nasopharyngitis and upper respiratory
tract infection.
Conclusions: Nemolizumab resulted in rapid and sustained
improvements in cutaneous signs of inflammation and pruritus
in patients with AD, with maximal efficacy observed at 30 mg.
Nemolizumab had an acceptable safety profile. (J Allergy Clin
Immunol 2020;145:173-82.
Immune state is associated with natural dietary variation in wild mice Mus musculus domesticus
1. The ability, propensity and need to mount an immune response vary both among individuals and within a single individual over time.2. A wide array of parameters have been found to influence immune state in carefully controlled experiments, but we understand much less about which of these parameters are important in determining immune state in wild populations.3. Diet can influence immune responses, for example when nutrient availability is limited. We therefore predict that natural dietary variation will play a role in modulating immune state, but this has never been tested.4. We measured carbon and nitrogen stable isotope ratios in an island population of house mice Mus musculus domesticus as an indication of dietary variation, and the expression of a range of immune?related genes to represent immune state.5. After accounting for potential confounding influences such as age, sex and helminth load, we found a significant association between carbon isotope ratio and levels of immune activity in the mesenteric lymph nodes, particularly in relation to the inflammatory response.6. This association demonstrates the important interplay between diet and an animal's response to immune challenges, and therefore potentially its susceptibility to disease
Livestock trade networks for guiding animal health surveillance
BACKGROUND: Trade in live animals can contribute to the introduction of exotic diseases, the maintenance and spread endemic diseases. Annually millions of animals are moved across Europe for the purposes of breeding, fattening and slaughter. Data on the number of animals moved were obtained from the Directorate General Sanco (DG Sanco) for 2011. These were converted to livestock units to enable direct comparison across species and their movements were mapped, used to calculate the indegrees and outdegrees of 27 European countries and the density and transitivity of movements within Europe. This provided the opportunity to discuss surveillance of European livestock movement taking into account stopping points en-route. RESULTS: High density and transitivity of movement for registered equines, breeding and fattening cattle, breeding poultry and pigs for breeding, fattening and slaughter indicates that hazards have the potential to spread quickly within these populations. This is of concern to highly connected countries particularly those where imported animals constitute a large proportion of their national livestock populations, and have a high indegree. The transport of poultry (older than 72 hours) and unweaned animals would require more rest breaks than the movement of weaned animals, which may provide more opportunities for disease transmission. Transitivity is greatest for animals transported for breeding purposes with cattle, pigs and poultry having values of over 50%. CONCLUSIONS: This paper demonstrated that some species (pigs and poultry) are traded much more frequently and at a larger scale than species such as goats. Some countries are more vulnerable than others due to importing animals from many countries, having imported animals requiring rest-breaks and importing large proportions of their national herd or flock. Such knowledge about the vulnerability of different livestock systems related to trade movements can be used to inform the design of animal health surveillance systems to facilitate the trade in animals between European member states. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12917-015-0354-4) contains supplementary material, which is available to authorized users
The macroecology of infectious diseases: a new perspective on global-scale drivers of pathogen distributions and impacts
© 2016 John Wiley & Sons Ltd/CNRS. Identifying drivers of infectious disease patterns and impacts at the broadest scales of organisation is one of the most crucial challenges for modern science, yet answers to many fundamental questions remain elusive. These include what factors commonly facilitate transmission of pathogens to novel host species, what drives variation in immune investment among host species, and more generally what drives global patterns of parasite diversity and distribution? Here we consider how the perspectives and tools of macroecology, a field that investigates patterns and processes at broad spatial, temporal and taxonomic scales, are expanding scientific understanding of global infectious disease ecology. In particular, emerging approaches are providing new insights about scaling properties across all living taxa, and new strategies for mapping pathogen biodiversity and infection risk. Ultimately, macroecology is establishing a framework to more accurately predict global patterns of infectious disease distribution and emergence
Kinetoplastid Phylogenomics Reveals the Evolutionary Innovations Associated with the Origins of Parasitism
The evolution of parasitism is a recurrent event in the history of life and a core problem in evolutionary biology. Trypanosomatids are important parasites and include the human pathogens Trypanosoma brucei, Trypanosoma cruzi, and Leishmania spp., which in humans cause African trypanosomiasis, Chagas disease, and leishmaniasis, respectively. Genome comparison between trypanosomatids reveals that these parasites have evolved specialized cell-surface protein families, overlaid on a well-conserved cell template. Understanding how these features evolved and which ones are specifically associated with parasitism requires comparison with related non-parasites. We have produced genome sequences for Bodo saltans, the closest known non-parasitic relative of trypanosomatids, and a second bodonid, Trypanoplasma borreli. Here we show how genomic reduction and innovation contributed to the character of trypanosomatid genomes. We show that gene loss has “streamlined” trypanosomatid genomes, particularly with respect to macromolecular degradation and ion transport, but consistent with a widespread loss of functional redundancy, while adaptive radiations of gene families involved in membrane function provide the principal innovations in trypanosomatid evolution. Gene gain and loss continued during trypanosomatid diversification, resulting in the asymmetric assortment of ancestral characters such as peptidases between Trypanosoma and Leishmania, genomic differences that were subsequently amplified by lineage-specific innovations after divergence. Finally, we show how species-specific, cell-surface gene families (DGF-1 and PSA) with no apparent structural similarity are independent derivations of a common ancestral form, which we call “bodonin.” This new evidence defines the parasitic innovations of trypanosomatid genomes, revealing how a free-living phagotroph became adapted to exploiting hostile host environments
The origin and development of nonlymphoid tissue CD103+ DCs
CD103+ dendritic cells (DCs) in nonlymphoid tissues are specialized in the cross-presentation of cell-associated antigens. However, little is known about the mechanisms that regulate the development of these cells. We show that two populations of CD11c+MHCII+ cells separated on the basis of CD103 and CD11b expression coexist in most nonlymphoid tissues with the exception of the lamina propria. CD103+ DCs are related to lymphoid organ CD8+ DCs in that they are derived exclusively from pre-DCs under the control of fms-like tyrosine kinase 3 (Flt3) ligand, inhibitor of DNA protein 2 (Id2), and IFN regulatory protein 8 (IRF8). In contrast, lamina propria CD103+ DCs express CD11b and develop independently of Id2 and IRF8. The other population of CD11c+MHCII+ cells in tissues, which is CD103−CD11b+, is heterogenous and depends on both Flt3 and MCSF-R. Our results reveal that nonlymphoid tissue CD103+ DCs and lymphoid organ CD8+ DCs derive from the same precursor and follow a related differentiation program
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