Neuropeptidomics of the Supraoptic Rat Nucleus

The mammalian supraoptic nucleus (SON) is a neuroendocrine center in the brain regulating a variety of physiological functions. Within the SON, peptidergic magnocellular neurons that project to the neurohypophysis (posterior pituitary) are involved in controlling osmotic balance, lactation, and parturition, partly through secretion of signaling peptides such as oxytocin and vasopressin into the blood. An improved understanding of SON activity and function requires identification and characteriza-tion of the peptides used by the SON. Here, small-volume sample preparation approaches are optimized for neuropeptidomic studies of isolated SON samples ranging from entire nuclei down to single magnocellular neurons. Unlike most previous mammalian peptidome studies, tissues are not im-mediately heated or microwaved. SON samples are obtained from ex vivo brain slice preparations via tissue punch and the samples processed through sequential steps of peptide extraction. Analyses of the samples via liquid chromatography mass spectrometry and tandem mass spectrometry result in the identification of 85 peptides, including 20 unique peptides from known prohormones. As the sample size is further reduced, the depth of peptide coverage decreases; however, even from individually isolated magnocellular neuroendocrine cells, vasopressin and several other peptides are detected

(1-x)(Na₀.₅Bi₀.₅)TiO₃-xCaTiO₃ ceramics: Investigating structural and microstructural features for enhanced dielectric properties

(1-x)(Na₀.₅Bi₀.₅)TiO₃-xCaTiO₃ Lead-free piezoelectric systems, positioned near the morphotropic phase boundary, were synthesized for varying compositions (x = 0.0, 0.05, 0.10, 0.15, and 0.20) using the solid-state reaction route. This study delves into the comprehensive investigation of the compositional effects on phase, structure, and electrical characteristics. Specifically, a morphotropic phase boundary (MPB) involving rhombohedral (R3c) and orthorhombic (Pnma) structures was seen in a (1-x)NBT-xCT crystal structure close to the composition of x = 0.10. Information on the pure phase formation and grain size of the intended composite system has been obtained using Rietveld refinement of the X-ray diffraction (XRD) diagram as well as scanning electron microscopy (SEM). The impact of the CT phase on the NBT lattice was investigated through an analysis of the charge density distribution. Using Williamson-Hall plots from XRD data, the average particle diameter was estimated to be between 131.87 nm and 136.54 nm. The relative permittivity increases with the addition of Ca2+, according to dielectric measurements. All ceramics exhibit a diffuse phase transition near (Tm) with a diffusivity range of 1.5–1.8, and a downward shift in depolarization temperature (Td). At the morphotropic phase boundary (MPB), excellent dielectric properties were observed at x = 0.10, which are attributed to the presence of both rhombohedral and orthorhombic structures as well as an appropriate particle size. The conduction process at different temperatures is thermally activated, as determined by the frequency-dependent ac conductivity

Airflow and microclimate patterns in a one-hectare Canary type greenhouse: an experimental and CFD assisted study

This study presents an analysis of air circulation and microclimate distribution during daytime in a 1-hectare Canary type tomato greenhouse in the coastal area of southern Morocco. The investigation of the climate inside the greenhouse is based on a numerical simulation using a finite volumes method to solve the mass, momentum and energy conservation equations. The main novelty of this simulation lies in the realism of the 3D modelling of this very large agricultural structure with (i) a coupling of convective and radiative exchanges at the surface of the plastic roof cover, (ii) simulation of the dynamic influence of the insect screens and tomato crop on airflow movement, using the concept of porous medium, (iii) simulation, in each grid cell of the crop canopy, of the sensible and latent heat exchanges between the greenhouse air and the tomato crop, and (iv) detailed simulation of climate parameters in a 1-hectare real-scale commercial greenhouse. The model simulations were first validated with respect to temperature and relative humidity fields measured inside the experimental greenhouse for fairly steady-state outside conditions marked by a prevailing sea breeze around the solar noon. A good agreement was observed between the measured and simulated values for inside air temperatures and specific humidity. It was next used for exploring the details of the inside air temperature and humidity fields and plant microclimates and transpiration fluxes throughout the greenhouse space. Simulation for a wind direction perpendicular to the side and roof openings shows that the insect screen significantly reduced inside air velocity and increased inside temperature and humidity, especially in the vicinity of the crop canopy. It revealed the details of the flow field within the greenhouse. At the windward end of the greenhouse, the flow field was marked by a strong windwise air current above the tomato canopy which was fed by the wind ward side vent, and a slow air stream flowing within the tomato canopy space. Then, from the first third of the greenhouse to the leeward end, the flow field was marked by the combination of wind and buoyancy forces, with warmer and more humid inside air which was evacuated through the upper roof vents, while colder and dryer air was penetrated through the upper roof vent openings. Based on these simulations, design studies of the greenhouse crop system were performed to improve inside air temperature and humidity conditions by simple modifications of orientation of the crop row

Computational study of thermal performance of an unheated canarian-type greenhouse: influence of the opening configurations on airflow and climate patterns at the crop level

International audienceThe increasing cost of electricity often drives the famers of the countries of the southern shore of the Mediterranean, to adopt the natural ventilation in order to provide greenhouse aeration. The roof and sidewall vents are opened to allow the excess heat to escape and cooler outside air to enter during daytime. During night time, these openings are used mainly to regulate the excess humidity in greenhouse which causes damage on plants due to the development of Botrytis cinerea. This paper presents a computational fluid dynamic (CFD) comparative study of the effect of these roof and sidewall ventilation openings on airflow circulation and diurnal and nocturnal greenhouse climate distribution to assess their effect. The investigation was conducted in a one hectare canarian-type greenhouse, the most widely used in Morocco, with a mature tomato crop. The simulations were performed with the CFD model based on solving partial differential equations, which represent conservation laws for the mass, momentum, and energy, using CFD finite volume method (FVM). This CFD model takes into account the virtual crop as a porous medium using the Darcy-Forchheimer model restricted to its inertial terms. Simulation results show that opening configurations strongly affects the airflow circulation under the studied greenhouse, which can generate a heterogeneous climate at the canopy level, especially during daytime. Results have illustrated also that there is a reverse flow from the leeward end to windward end part of the greenhouse at the crop level. Closing the north-south sidewall ventilation openings contributes significantly to the inside air velocity increase which can decrease the diurnal air temperature at the crop level. Conversely, during night-time, climate distribution at the crop level is homogeneous on the whole greenhouse

Does insect netting affect the containment of airborne pollen from (GM-) plants in greenhouses?

Greenhouses are a well-accepted containment strategy to grow and study genetically modified plants (GM) before release into the environment. Various containment levels are requested by national regulations to minimize GM pollen escape. We tested the amount of pollen escaping from a standard greenhouse, which can be used for EU containment classes 1 and 2. More specifically, we investigated the hypothesis whether pollen escape could be minimized by insect-proof netting in front of the roof windows, since the turbulent airflow around the mesh wiring could avoid pollen from escaping. We studied the pollen flow out of greenhouses with and without insect netting of two non-transgenic crops, Ryegrass (Lolium multiflorum) and Corn (Zea Mays). Pollen flow was assessed with Rotorod® pollen samplers positioned inside and outside the greenhouse’ roof windows. A significant proportion of airborne pollen inside the greenhouse leaves through roof windows. Moreover, the lighter pollen of Lolium escaped more readily than the heavier pollen of Maize. In contrast to our expectations, we did not identify any reduction in pollen flow with insect netting in front of open windows, even under induced airflow conditions. We conclude that insect netting, often present by default in greenhouses, is not effective in preventing pollen escape from greenhouses of wind-pollinated plants for containment classes 1 or 2. Further research would be needed to investigate whether other alternative strategies, including biotic ones, are more effective

Single-cell analysis reveals inflammatory interactions driving macular degeneration

Abstract Due to commonalities in pathophysiology, age-related macular degeneration (AMD) represents a uniquely accessible model to investigate therapies for neurodegenerative diseases, leading us to examine whether pathways of disease progression are shared across neurodegenerative conditions. Here we use single-nucleus RNA sequencing to profile lesions from 11 postmortem human retinas with age-related macular degeneration and 6 control retinas with no history of retinal disease. We create a machine-learning pipeline based on recent advances in data geometry and topology and identify activated glial populations enriched in the early phase of disease. Examining single-cell data from Alzheimer’s disease and progressive multiple sclerosis with our pipeline, we find a similar glial activation profile enriched in the early phase of these neurodegenerative diseases. In late-stage age-related macular degeneration, we identify a microglia-to-astrocyte signaling axis mediated by interleukin-1β which drives angiogenesis characteristic of disease pathogenesis. We validated this mechanism using in vitro and in vivo assays in mouse, identifying a possible new therapeutic target for AMD and possibly other neurodegenerative conditions. Thus, due to shared glial states, the retina provides a potential system for investigating therapeutic approaches in neurodegenerative diseases