Search Results (21)

Chronic, non-resolving inflammation is a major contributor to impaired wound healing in diabetes. Annexin A1 (AnxA1), a pro-resolving mediator, and its mimetic peptide Ac_2–26 have demonstrated therapeutic potential in modulating inflammatory responses. In this study, we evaluated the effects of topical Ac_2–26 hydrogel in a streptozotocin-induced diabetic wound model. Treatment significantly accelerated wound closure, improved tissue architecture, and reduced leukocyte infiltration. Immunohistochemical analysis revealed diminished mast cell accumulation and IL-1β expression in treated wounds. Complementary transcriptomic profiling supported the downregulation of pro-inflammatory genes, including Il1b and mast cell-related mediators, confirming the peptide’s regulatory effect on the wound immune landscape. Mounting evidence suggests that dysregulated mast cell activity plays a role in the heightened inflammatory tone and delayed tissue repair observed in diabetic wounds. In our model, Ac_2–26 hydrogel treatment attenuated IL-1β expression, suggesting an indirect downregulation of NLRP3 inflammasome activation, potentially mediated through mast cell modulation, though effects on other cell types within the wound microenvironment cannot be excluded. While definitive causality cannot be assigned, the integration of histological and transcriptomic data highlights mast cells as contributors to the IL-1β-driven inflammatory burden in diabetic wounds. These findings underscore the immunomodulatory capacity of Ac_2–26 and its potential to restore resolution pathways in chronic wound settings, positioning it as a promising candidate for future therapeutic development. Full article

Mouse models serve as a means of examining immune changes when genes of interest are knocked out (KO). One group of immune gene-producing cells that have been identified is type 2 innate lymphoid cells (Ilc2). These cells are involved in the production of Th2 equivalent immune responses and signal cytokine production during the resolution of Nippostrongylus brasiliensis parasite infection in mice lungs. However, many questions about Ilc2 activity in the gut remain. To study this, retinoic acid receptor (RAR)-related orphan receptor alpha (RORα)-deficient mice were infected with adult N. brasiliensis and arranged into four treatment groups. Ten days post-infection (dpi), mouse ileum tissue was extracted for RNA-Seq. The RORα-deficient mice showed little change in gene expression at 10 dpi (N = 51) when compared to the WT mice at 10 dpi (N = 915), displaying dysregulation within the mouse gut. Based on the results, the gene expression in the gut of Ilc2-deficient mice denoted that the inability to craft Ilc2 cells left the mice unable to mount classical helminth immune responses involving humoral, mast cell, and antibody Th2-driven reactions. Overall, the results showed the importance of Ilc2 in the gut during N. brasiliensis infections and the effect that the lack of these cells had on immunity. Full article

Forests and trees provide a variety of essential ecosystem services. Maintaining them is becoming increasingly important, as global and regional climate change is already leading to major changes in the structure and composition of forests. To minimize the negative effects of storm damage risk, the tree and stand characteristics on which the storm damage risk depends must be known. Previous work in this field has consisted of tree-pulling tests and targets attached to selected branches. They fail, however, since the mass of such targets is very high compared to the mass of the branches, causing the targets to influence the tree’s response significantly, and because they cannot model dynamic wind loads. We, therefore, installed a multi-camera system consisting of nine cameras that are mounted on four masts surrounding a tree. With those cameras acquiring images at a rate of 10 Hz, we use photogrammetry and a semi-automatic feature-matching workflow to deduce a 3D model of the tree crown over time. Together with motion sensors mounted on the tree and tree-pulling tests, we intended to learn more about the wind-induced tree response of all dominant aerial tree parts, including the crown, under real wind conditions, as well as dampening processes in tree motion. Full article

The availability of multi-rotor UAVs with lifting capacities of several kilograms allows for a new paradigm in atmospheric measurement techniques, i.e., the integration of research-grade sonic anemometers for airborne turbulence measurements. With their ability to hover and move very slowly, this approach yields unrevealed flexibility compared to mast-based sonic anemometers for a wide range of boundary layer investigations that require an accurate characterization of the turbulent flow. For an optimized sensor placement, potential disturbances by the propeller-induced flow (PIF) must be considered. The PIF characterization can be done by CFD simulations, which, however, require validation. For this purpose, we conducted an experiment to map the PIF below a multi-rotor drone using a mobile array of five sonic anemometers. To achieve measurements in a controlled environment, the drone was mounted inside a hall at a 90° angle to its usual flying orientation, thus leading to the development of a horizontal downwash, which is not subject to a pronounced ground effect. The resulting dataset maps the PIF parallel to the rotor plane from two rotor diameters, beneath, to 10 D, and perpendicular to the rotor plane from the center line of the downwash to a distance of 3 D. This measurement strategy resulted in a detailed three-dimensional picture of the downwash below the drone in high spatial resolution. The experimental results show that the PIF quickly decreases with increasing distance from the centerline of the downwash in the direction perpendicular to the rotor plane. At a distance of 1 D from the centerline, the PIF reduced to less than 4 ms⁻¹ within the first 5 D beneath the drone, and no conclusive disturbance was measured at 2 D out from the centerline. A PIF greater than 4 ms⁻¹ was still observed along the center of the downwash at a distance of 10 D for both throttle settings tested (35% and 45%). Within the first 4 D under the rotor plane, flow convergence towards the center of the downwash was measured before changing to diverging, causing the downwash to expand. This coincides with the transition from the four individual downwash cores into a single one. The turbulent velocity fluctuations within the downwash were found to be largest towards the edges, where the shear between the PIF and the stagnant surrounding air is the largest. Full article

Both scientific and industrial communities have a growing interest in marine renewable energies. There is a wide variety of technologies in this domain, with different degrees of maturity. This study focuses on two models of a mast-free vertical axis Darrieus tidal turbine with the objective of characterizing the effect of vertical confinement, rotor configuration, and fluid–structure interactions on their performances in free-surface flows. The first model comprised four straight rigid blades maintained by circular flanges on both ends of the rotor and the second model is equipped with free-ended interchangeable blades attached to a single upper flange. Two configurations of the second model mounted with either rigid or flexible blades were used, first for comparison with the dual-flange turbine, then in order to address the effect of fluid–structure interactions on the turbine performances. While the single-flange models exhibit a significantly lower efficiency at all operating points, it is observed that the use of flexible blades tends to enhance turbine performances at low Reynolds numbers. The flow topology obtained from PIV measurement at selected operating points is discussed with respect to the performance of each turbine model in order to highlight the role of the dynamic stall and blade–vortex interactions. Full article

This paper analyzes the field performance of two cup anemometers installed in Zaragoza (Spain). Data acquired over almost three years, from January 2015 to December 2017, were analyzed. The effect of the different variables (wind speed, temperature, harmonics, wind speed variations, etc.) on two cup anemometers was studied. Data analysis was performed with ROOT, an open-source scientific software toolkit developed by CERN (Conseil Européen pour la Recherche Nucléaire) for the study of particle physics. The effects of temperature, wind speed, and wind dispersion (as a first approximation to atmospheric turbulence) on the first and third harmonics of the anemometers’ rotation speed (i.e., the anemometers’ output signature) were studied together with their evolution throughout the measurement period. The results are consistent with previous studies on the influence of velocity, turbulence, and temperature on the anemometer performance. Although more research is needed to assess the effect of the anemometer wear and tear degradation on the harmonic response of the rotor’s angular speed, the results show the impact of a recalibration on the performance of an anemometer by comparing this performance with that of a second anemometer. Full article

Whereas autoimmune diseases are mediated primarily by T and B cells, auto-inflammatory syndromes (AIFS) involve natural killer cells, macrophages, mast cells, dendritic cells, different granulocyte subsets and complement components. In contrast to autoimmune diseases, the immune response of patients with AIFS is not associated with a breakdown of immune tolerance to self-antigens. Focusing on B lymphocyte subsets, this article offers a fresh perspective on the multiple cross-talks between both branches of innate and adaptive immunity in mounting coordinated signals that lead to AIFS. By virtue of their potential to play a role in adaptive immunity and to exert innate-like functions, B cells can be involved in both promoting inflammation and mitigating auto-inflammation in disorders that include mevalonate kinase deficiency syndrome, Kawasaki syndrome, inflammatory bone disorders, Schnitzler syndrome, Neuro-Behçet’s disease, and neuromyelitis optica spectrum disorder. Since there is a significant overlap between the pathogenic trajectories that culminate in autoimmune diseases, or AIFS, a more detailed understanding of their respective roles in the development of inflammation could lead to designing novel therapeutic avenues. Full article

To meet the growing energy demand and increasing environmental concerns, clean and renewable fluid energy, such as wind and ocean energy, has received considerable attention. This study proposes a bladeless wind energy–harvesting device based vortex-induced vibrations (VIV). The proposed design is mainly composed of a base, a hollow mast, and an elastic rod. The proposed design takes advantage of vortices generated when the airflow interacts with the mast, and the flow splits and then separates and generates vortices that eventually make the elastic rod oscillate, and out of these oscillations, energy can be harvested. Different airflow disruption geometries are studied and tested numerically and experimentally to identify the most effective shape and orientation for converting wind energy to electric energy. Computational fluid dynamics (CFD) modeling and simulations were performed on the elastic mast, a VIV device’s core wind energy–collecting component, to guide the device’s design. These simulations examined the mast-produced lift coefficient, velocity, pressure, and vorticity contours of different mast geometries. The mast’s vibration energy under different wind intensities was also experimentally tested using a scaled model in the wind tunnel. The level of converted electric power was measured and monitored using piezoelectric sensors mounted at different locations on the mast. The experimental study identified the ideal orientation angle of the mast and the best location for the piezoelectric sensors for harnessing more energy. The experiments confirmed the CFD simulation results that a complex cylinder design produces more power. The combined numerical and experimental studies led to an environmentally friendly, new VIV design with much improved power generation capabilities. Full article

The human host immune responses to parasitic infections are complex. They can be categorized into four immunological pathways mounted against four types of parasitic infections. For intracellular protozoa, the eradicable host immunological pathway is TH1 immunity involving macrophages (M1), interferon gamma (IFNγ) CD4 T cells, innate lymphoid cells 1 (NKp44+ ILC1), CD8 T cells (Effector-Memory4, EM4), invariant natural killer T cells 1 (iNKT1) cells, and immunoglobulin G3 (IgG3) B cells. For intracellular protozoa, the tolerable host immunological pathway is TH1-like immunity involving macrophages (M2), interferon gamma (IFNγ)/TGFβ CD4 T cells, innate lymphoid cells 1 (NKp44- ILC1), CD8 T cells (EM3), invariant natural killer T 1 (iNKT1) cells, and immunoglobulin A1 (IgA1) B cells. For free-living extracellular protozoa, the eradicable host immunological pathway is TH22 immunity involving neutrophils (N1), interleukin-22 CD4 T cells, innate lymphoid cells 3 (NCR+ ILC3), iNKT17 cells, and IgG2 B cells. For free-living extracellular protozoa, the tolerable host immunological pathway is TH17 immunity involving neutrophils (N2), interleukin-17 CD4 T cells, innate lymphoid cells 3 (NCR- ILC3), iNKT17 cells, and IgA2 B cells. For endoparasites (helminths), the eradicable host immunological pathway is TH2a immunity with inflammatory eosinophils (iEOS), interleukin-5/interleukin-4 CD4 T cells, interleukin-25 induced inflammatory innate lymphoid cells 2 (iILC2), tryptase-positive mast cells (MCt), iNKT2 cells, and IgG4 B cells. For ectoparasites (parasitic insects and arachnids), the eradicable host immunological pathway is TH2b immunity with inflammatory basophils, chymase- and tryptase-positive mast cells (MCct), interleukin-3/interleukin-4 CD4 T cells, interleukin-33 induced nature innate lymphoid cells 2 (nILC2), iNKT2 cells, and immunoglobulin E (IgE) B cells. The tolerable host immunity against ectoparasites and endoparasites is TH9 immunity with regulatory eosinophils, regulatory basophils, interleukin-9 mast cells (MMC9), thymic stromal lymphopoietin induced innate lymphoid cells 2, interleukin-9 CD4 T cells, iNKT2 cells, and IgA2 B cells. In addition, specific transcription factors important for specific immune responses were listed. This JAK/STAT signaling is key to controlling or inducing different immunological pathways. In sum, Tfh is related to STAT5β, and BCL6 expression. Treg is related to STAT5α, STAT5β, and FOXP3. TH1 immunity is related to STAT1α, STAT4, and T-bet. TH2a immunity is related to STAT6, STAT1α, GATA1, and GATA3. TH2b immunity is related to STAT6, STAT3, GATA2, and GATA3. TH22 immunity is associated with both STAT3α and AHR. THαβ immunity is related to STAT1α, STAT1β, STAT2, STAT3β, and ISGF. TH1-like immunity is related to STAT1α, STAT4, STAT5α, and STAT5β. TH9 immunity is related to STAT6, STAT5α, STAT5β, and PU.1. TH17 immunity is related to STAT3α, STAT5α, STAT5β, and RORG. TH3 immunity is related to STAT1α, STAT1β, STAT2, STAT3β, STAT5α, STAT5β, and ISGF. This categorization provides a complete framework of immunological pathways against four types of parasitic infections. This framework as well as relevant JAK/STAT signaling can provide useful knowledge to control allergic hypersensitivities and parasitic infections via development of vaccines or drugs in the near future. Full article

Floating LIDAR systems (FLS) are a cost-effective way of surveying the wind energy potential of an offshore area. However, as turbulence intensity estimates are strongly affected by wave-induced buoy motion, it is essential to correct them. In this study, we quantify the turbulence intensity measurement error of a WindCube v2^® mounted on a 12-ton anchored buoy as a function of met-ocean conditions, and we construct a subsequently applied correction method suitable for 10-min wind LIDAR data storage. To this end, we build a model to simulate the effect of buoyancy movements on the LIDAR’s wind measurements. We first apply the model to understand the mechanisms responsible for the wind LIDAR measurement error. The effect of the buoy’s rotational and translational motions on the radial wind speed measurements of the individual beams is first studied. Second, the temporality induced by the LIDAR operation is taken into account; the effect of motion subsampling and the interaction between the different measurement beam positions. From this model, a correction method is developed and successfully applied to a 13-week experimental campaign conducted off the shores of Fécamp (Normandie, France) involving the buoy-mounted WindCube v2^® compared with cup anemometers from a met mast and a fixed WindCube v2^® on a platform. The correction improves the linear regression against the fixed LIDAR turbulence intensity measurements, shifting the offset from ~0.03 to ~0.005 without post-processing the remaining peaks. Full article

Downwind turbines have favorable characteristics such as effective energy capture in up-flow wind conditions over complex terrains. They also have reduced risk of severe accidents in the event of disruptions to electrical networks during strong storms due to the free-yaw effect of downwind turbines. These favorable characteristics have been confirmed by wind-towing tank experiments and computational fluid dynamics (CFD) simulations. However, these advantages have not been fully demonstrated in field experiments on actual wind farms. In this study—although the final objective was to demonstrate the potential advantages of downwind turbines through field experiments—field measurements were performed using a vertical-profiling light detection and ranging (LiDAR) system on a wind farm with downwind turbines installed in complex terrains. To deduce the horizontal wind speed, vertical-profiling LiDARs assume that the flow of air is uniform in space and time. However, in complex terrains and/or in wind farms where terrain and/or wind turbines cause flow distortion or disturbances in time and space, this assumption is not valid, resulting in erroneous wind speed estimates. The magnitude of this error was evaluated by comparing LiDAR measurements with those obtained using a cup anemometer mounted on a meteorological mast and detailed analysis of line-of-sight wind speeds. A factor that expresses the nonuniformity of wind speed in the horizontal measurement plane of vertical-profiling LiDAR is proposed to estimate the errors in wind speed. The possibility of measuring and evaluating various wind characteristics such as flow inclination angles, turbulence intensities, wind shear and wind veer, which are important for wind turbine design and for wind farm operation is demonstrated. However, additional evidence of actual field measurements on wind farms in areas with complex terrains is required in order to obtain more universal and objective evaluations. Full article

In this paper, an extremely low-profile ferrite dipole antenna operating on the VHF band (30–300 MHz) is proposed. The design antenna consists of 44 plate-type ferrite cells arranged into two stacked ferrite layers: a bottom ferrite layer with $2\times 12$ grid cells and a top ferrite layer with $2\times 10$ grid cells. The antenna is excited by an electric loop feeding structure and maximum gain performance is achieved when the loop feeding structure has five loops. To validate the performance of the proposed antenna, an antenna prototype is fabricated and tested at an outdoor range. The antenna weighs 1.45 kg and has electrical dimensions of approximately 0.0636 $\times$ 0.0112 $\times$ 0.0008 ${\lambda }_L^3$ at the lowest operating frequency of 30 MHz. The measured realized gain varies from −31.48 to −2.44 dBi within the VHF band. Reasonable agreement is also obtained between the measurement and simulation results. To assess the performance of the proposed antenna, it was mounted on the integrated mast of an offshore patrol vessel (OPV) model. The antenna on the OPV was also simulated and the results discussed. Full article

This work describes a study using multi-view hyperspectral imagery to retrieve sediment filling factor through inversion of a modified version of the Hapke radiative transfer model. We collected multi-view hyperspectral imagery from a hyperspectral imaging system mounted atop a telescopic mast from multiple locations and viewing angles of a salt panne on a barrier island at the Virginia Coast Reserve Long-Term Ecological Research site. We also collected ground truth data, including sediment bulk density and moisture content, within the common field of view of the collected hyperspectral imagery. For samples below a density threshold for coherent effects, originally predicted by Hapke, the retrieved sediment filling factor correlates well with directly measured sediment bulk density ( $R^2=0.85$ ). The majority of collected samples satisfied this condition. The onset of the threshold occurs at significantly higher filling factors than Hapke’s predictions for dry sediments because the salt panne sediment has significant moisture content. We applied our validated inversion model to successfully map sediment filling factor across the common region of overlap of the multi-view hyperspectral imagery of the salt panne. Full article

Results of an observational campaign and model study are presented demonstrating how the wind field at roof-level in the urban area of Vienna changed due to the construction of a new building nearby. The investigation was designed with a focus on the wind energy yield of a roof-mounted small wind turbine but the findings are also relevant for air dispersion applications. Wind speed profiles above roof top are simulated with the complex fluid dynamics (CFD) model MISKAM (Mikroskaliges Klima- und Ausbreitungsmodell, microscale climate and dispersion model). The comparison to mast measurements reveals that the model underestimates the wind speeds within the first few meters above the roof, but successfully reproduces wind conditions at 10 m above the roof top (corresponding to about 0.5 times the building height). Scenario simulations with different building configurations at the adjacent property result in an increase or decrease of wind speed above roof top depending on the flow direction at the upper boundary of the urban canopy layer (UCL). The maximum increase or decrease in wind speed caused by the alternations in building structure nearby is found to be in the order of 10%. For the energy yield of a roof-mounted small wind turbine at this site, wind speed changes of this magnitude are negligible due to the generally low prevailing wind speeds of about 3.5 m s⁻¹. Nevertheless, wind speed changes of this order could be significant for wind energy yield in urban areas with higher mean wind speeds. This effect in any case needs to be considered in siting and conducting an urban meteorological monitoring network in order to ensure the homogeneity of observed time-series and may alter the emission and dispersion of pollutants or odor at roof level. Full article

Salt marsh vegetation density varies considerably on short spatial scales, complicating attempts to evaluate plant characteristics using airborne remote sensing approaches. In this study, we used a mast-mounted hyperspectral imaging system to obtain cm-scale imagery of a salt marsh chronosequence on Hog Island, VA, where the morphology and biomass of the dominant plant species, Spartina alterniflora, varies widely. The high-resolution hyperspectral imagery allowed the detailed delineation of variations in above-ground biomass, which we retrieved from the imagery using the PROSAIL radiative transfer model. The retrieved biomass estimates correlated well with contemporaneously collected in situ biomass ground truth data ( $R^2=0.73$ ). In this study, we also rescaled our hyperspectral imagery and retrieved PROSAIL salt marsh biomass to determine the applicability of the method across spatial scales. Histograms of retrieved biomass changed considerably in characteristic marsh regions as the spatial scale of the imagery was progressively degraded. This rescaling revealed a loss of spatial detail and a shift in the mean retrieved biomass. This shift is indicative of the loss of accuracy that may occur when scaling up through a simple averaging approach that does not account for the detail found in the landscape at the natural scale of variation of the salt marsh system. This illustrated the importance of developing methodologies to appropriately scale results from very fine scale resolution up to the more coarse-scale resolutions commonly obtained in airborne and satellite remote sensing. Full article