Water Movement Research Articles

Enhancing malting performance of harder barley varieties through ultrasound treatment

Harder kernels of barley are regarded as one of the factors that restrict water and enzyme movement within the endosperm during malting. A comprehensive study of two domestic varieties was performed for evaluating malting quality. Both β-glucan and total protein content of the Chinese domestic barley (Ganpi-6 and Kenpi-14) were significantly higher than Copeland. Grain hardness of the Chinese domestic barley was higher and water uptake ratio was lower compared with the Copeland. During germination, the expression levels of NCED1, NCED2 (major key regulatory enzymes for abscisic acid biosynthesis genes) were higher, whereas gibberelic acid (GA) synthesis genes (GA20ox1, GA2ox3, GA3ox2) were lower in the Ganpi-6, Kenpi-14 compared with Copeland. These two domestic barley varieties also showed significantly lower limit dextrinase and β-glucanase activity compared with Copeland. Ultrasound treatment improved the malting quality of Ganpi-6 by enhancing water uptake and GA synthesis gene expression increased. Therefore, these findings provided insights into the future direction on the utilization of ultrasonication for the applications towards the improvement of the harder barley variety.

Limiting physical properties of Technosols formed by the Fundão dam failure, Minas Gerais, Brazil

ABSTRACT Physical properties of the Technosols formed by the tailings deposition may constitute a physical barrier that limits water movement and plant development due to the properties received from those sediments. This study aimed to evaluate the physical quality of the Technosols formed by the deposition of sediments displaced by the Fundão Dam failure, Mariana, Minas Gerais State, Brazil, based on the evaluation of physical properties and Load Bearing Capacity Models (LBCM). For that, three areas under different vegetation types were selected: eucalyptus (Euc), forest with human-assisted revegetation (RF), and forest with native vegetation (NF). Three sampling subareas were demarcated in each area: non-impacted areas (Ni), and Technosols formed in directly impacted areas (Di), and partially impacted areas (Pi). Undisturbed samples were collected in two layers and subjected to the uniaxial compression test after equilibration at five matric potentials. Soil compression curves and LBCM were determined. Soil bulk density (BD), total porosity (TP), organic matter (OM), granulometry, and particle density (PD) were also determined. Clay content was less significant, and the silt and very fine sand content was significantly higher in the Technosols, generating an increase in BD and reduction in TP. Technosols generally exhibited greater load-bearing capacity due to higher pre-consolidation pressure values attained by these soils due to the lower clay and OM contents. High resistance of these soils is one limitation for revegetation of the areas evaluated, being necessary management practices to improve physical properties of the Technosols.

On the existence of flux as a function of the surface elevation for long wave solution of shallow water equations

The shallow water equations in mechanics of fluids, govern the motion of a shallow layer of water over a fixed impervious bed. In this paper, the bed form is assumed to be rough and horizontal, and the motion of water is assumed to be of the long wave type (Lamb [1], pp. 254-256) such that the free surface has a gradually varying propagating profile. Gravitation permits such motion but is resisted by the turbulence generated by the bed friction. A model of the governing equations based on the Reynolds averaged Navier-Stokes equations has recently been given by Bose [2], which is highly nonlinear. A heuristic approach of numerically solving the equations for the modified long waves is also presented in that article, by assuming that the horizontal flux across a section of flow is some function of the free surface elevation alone. This key assertion is analysed in this article and proved to hold provided some boundedness criteria are satisfied by the flux gradients. The theory is apparently applicable to find appropriate boundedness conditions on the flux of flow for numerically solving long wave equations in the case of other models for long wave propagation as well.

Effect of guar gum on the rheological properties, microstructure and 3D printing performance of egg yolk powder-potato starch composite gel

This work explored the effects of guar gum (GG) concentration (0, 0.9, 1.8, 2.7, 3.6, 4.5 g) on the rheological properties, water distribution, microstructure and 3D printing performance of egg yolk powder-potato starch (EYP-PS) composite gels. The results showed that EYP-PS inks with GG added showed higher gel modulus, apparent viscosity, and hardness compared to the “Control”. Low-field nuclear magnetic resonance (LF-NMR) results indicated that GG was able to restrict the free movement of water and promote the migration of EYP-PS to tightly bound water. The microstructure results showed that GG could induce EYP-PS to form a denser network structure, and EYP-PS inks with an appropriate amount of GG showed better springiness. Fourier transform infrared spectroscopy (FT-IR) confirmed that the addition of GG did not create new functional groups in EYP-PS, but enhanced the hydrogen bonding in the gels. Overall, GG-1.8 and GG-2.7 exhibited the best 3D printing performance and were more suitable for patients with swallowing disorders. This study contributes to the development of 3D-printed gel food containing egg yolk powder as well as exploring the effect of GG on egg yolk powder-starch composite food materials.

An aquaporin and an aquaglyceroporin have roles in low temperature adaptation of mosquitoes (Anopheles sinensis).

Mosquitoes (Anopheles sinensis), widely geographically distributed in Asia including China, are the primary vector of the malaria parasite Plasmodium vivax and other parasitic diseases such as Malayan filariasis. An. sinensis can survive through low winter temperatures. Aquaporin channels are found in all life forms, where they facilitate environmental adaptation by allowing rapid trans-cellular movement of water (classical aquaporins) or water and solutes such as glycerol (aquaglyceroporins). Here, we identified and characterized 2 aquaporin (AQP) homologs in An. sinensis: AsAQP2 (An. sinensis aquaglyceroporin) and AsAQP4 (An. sinensis aquaporin). When expressed in frog (Xenopus laevis) oocytes, AsAQP2 transported water, glycerol, and urea; AsAQP4 transported only water. Water permeation through AsAQP2 and AsAQP4 was inhibited by mercuric chloride. AsAQP2 expression was slightly higher in adult female mosquitoes than in males, and AsAQP4 expression was significantly higher in adult males. The 2 AsAQPs were highly expressed in Malpighian tubules and midgut. AsAQP2 and AsAQP4 expression was up-regulated by blood feeding compared with sugar feeding. At freezing point (0°C), the AsAQP4 expression level increased and An. sinensis survival time reduced compared with those at normal temperature (26°C). At low temperature (8°C), the AsAQP2 and AsAQP4 expression levels decreased and survival time was significantly longer compared with those at 26°C. These results suggest that AsAQP2 and AsAQP4 have roles in water homeostasis during blood digestion and in low temperature adaptation of A. sinensis. Together, our results show that the 2 AQPs are important for mosquito diuresis after blood feeding and when exposed to low temperatures.

Experimental investigation of thawing behavior of saline soils using resistivity method

Abstract Electrical resistivity method has been widely used to study permafrost and to monitor the process of freezing-thawing. However, a thorough understanding of the mechanism of electrical response during thawing is missing. In this study, we investigated the thawing behavior of saline soils in the temperature range from roughly −10 to 15°C considering the effects of soil type and salinity. A total of nine experiments were performed with three soil types (silica sand, sandy soil, and silt) and three salinities (0.01, 0.1, and 1 S m−1). The results show that resistivity variations with temperature can be divided into three stages. In Stage I, tortuosity and unfrozen water content play major roles in the decrease of resistivity. In Stage Ⅱ, which is an isothermal or near isothermal process, resistivity still decreases slightly due to the thawing of residual ice and pore water movement. In Stage III, ionic mobility plays an important impact on decreasing resistivity. In addition, the isothermal process is found to only occur in silica sand that can be explained by latent heat effect. Exponential and linear models linking temperature with resistivity are used to fit the experimental data in Stages I and III. The fitting parameter in different models shows great correlation with soil type and salinity. Furthermore, unfrozen water content below 0°C is also estimated and uncertainty of estimation is analyzed.

The Most Likely Flooded Soil in Terengganu State During Historically Greatest Rainfall Intensity

Water infiltration in the soil is an essential topic for investigation because soil fully saturated with water forms standing water that leads to flooding on top of the soil. Soil investigation is vital for agricultural study due to the necessity to know soil carrying capacity in holding water, field capacity, and also the soil temperature for biological activities and chemical reactions. However, human urbanization and expansion into previously unexplored soil areas could lead to unnecessary environmental stress, such as floods. Floodwater forms when the rainfall intensity exceeds soil water infiltration. The flood event is crucial since it affects the human livelihood and facility damages. Therefore, a good understanding of soil hydraulic water infiltration helps better understanding the cause of flood occurrence. The current study examines the soil series in Terengganu state with its soil properties concerning the soil water characteristics curve, which indicates the soil's ability to absorb and allow water movement in the ground. The equation used was the improved Richards’ equation that can be applied to examine the standing water or floodwater impacts on water infiltration. Also, the unsaturated soil moisture movement conditions can be investigated. The simulation equation verifies with benchmark datasets that was solved on Richards’ equation using a different numerical method. The twelve-soil series of Terengganu state subjected to water infiltration study subjected to flooded conditions, by exposing the soil to the highest rainfall identified in the history of Kuala Terengganu from 1985 to early 2023. The results reveal Jambu, Rhu Tapai and Rudua soil series' water infiltration rate was greater than the rainfall intensity, whereas other soil series could not accommodate the rainfall intensity. Thus, other soil series areas will likely encounter flooded conditions when exposed to heavy rainfall, as has occurred in history.

Case Study of Emerging Groundwater Management Issues at the Forefront of Large-scale Production from a Confined Aquifer: The Vista Ridge Project

Continued population growth, increased demands for water and declining water availability are statewide water concerns in Texas. The development and movement of water from where it is to where it is needed brings with it benefits to the receiving area and concerns for the area of origin. The Vista Ridge project serves as an on-point example and case study of such concerns and processes that can mitigate, in part, negative impacts that are informative to other Texans who will soon be facing similar pressures.. Impacts on the water levels in existing wells made the Vista Ridge Project a focus of significant public discussion in 2022, including Texas House and Senate interim session hearings. This paper spotlights groundwater management issues prominent in the Vista Ridge Project that will likely be of concern with other Texas groundwater projects in the near future. These issues involve well mitigation, significant impacts from groundwater production across groundwater conservation district boundaries, meaningful consideration of nine factors in Texas Water Code §36.108(d), the balance between limiting groundwater production, development of fair share doctrines, the role of the Texas Water Development Board in the

Dynamics of Fluids in the Cavity of a Rotating Body: A Review of Analytical Solutions

Since the middle of the 20th century, an understanding of the diversity of the natural magnetohydrodynamic phenomena surrounding us has begun to emerge. Magnetohydrodynamic nature manifests itself in such seemingly heterogeneous processes as the flow of water in the world’s oceans, the movements of Earth’s liquid core, the dynamics of the solar magnetosphere and galactic electromagnetic fields. Their close relationship and multifaceted influence on human life are becoming more and more clearly revealed. The study of these phenomena requires the development of theory both fundamental and analytical, unifying a wide range of phenomena, and specialized areas that describe specific processes. The theory of translational fluid motion is well developed, but for most natural phenomena, this condition leads to a rather limited model. The fluid motion in the cavity of a rotating body such that the Coriolis forces are significant has been studied much less. A distinctive feature of the problems under consideration is their significant nonlinearity, (i.e., the absence of a linear approximation that allows one to obtain nontrivial useful results). From this point of view, the studies presented here were selected. This review presents studies on the movements of ideal and viscous fluids without taking into account electromagnetic phenomena (non-conducting, non-magnetic fluid) and while taking them into account (conducting fluid). Much attention is payed to the macroscopic movements of sea water (conducting liquid) located in Earth’s magnetic field, which spawns electric currents and, as a result, an induced magnetic field. Exploring the processes of generating magnetic fields in the moving turbulent flows of conducting fluid in the frame of dynamic systems with distributed parameters allows better understanding of the origin of cosmic magnetic fields (those of planets, stars, and galaxies). Various approaches are presented for rotational and librational movements. In particular, an analytical solution of three-dimensional unsteady magnetohydrodynamic equations for problems in a plane-parallel configuration is presented.

ESTIMATION OF SOIL WETTING PATTERN USING DIFFERENT IRRIGATION REGIMES IN CONJUCTION WITH SUPER ABSORBENT POLYMER

The design and management of irrigation systems require soil water movement and distribution knowledge. Finding the actual ability of drip irrigation to supply sufficient water uniformly and timely requires optimizing the operational management parameters. The objective of the study was to estimate the water distribution pattern with drip irrigation under different irrigation frequencies, durations and Belsap super absorbent polymer. A factorial experimental design layout of drip irrigation system was set up in Noiwet, Mogotio Sub County, Baringo County. The same quantity of water with three irrigation frequencies were applied once daily, after two days and three days and three durations which were full, half and a third the irrigation time. The total number of treatments were 18 with three replications making a total of 54 experiments. The wetted depths and widths of the soil were measured directly in the field using a ruler immediately after irrigation. ANOVA statistical analysis was carried out to determine the significance of the treatments on the soil wetting pattern of the clay soil. The results from the study revealed that the super absorbent polymer had no effect on the soil wetting pattern while the decrease in the irrigation frequency and increase in irrigation duration led to an enlargement in both the diameter and depth of the soil wetted zone. Information on depths and widths of wetted zone of soil under drip irrigation have a great significance in the design and management of drip irrigation system for delivering required quantity of water and chemicals to plants.

Effect of water movement in frozen soil on long-term hydrological simulation of Soil and Water Assessment Tool in cold climate watershed in Hokkaido, Japan

ABSTRACT Despite the unique hydrological properties exhibited by frozen soil, its characteristics are often oversimplified in most distributed hydrological models, resulting in major errors in material cycle predictions in cold climate regions. This study aims to modify the Soil and Water Assessment Tool (SWAT), a semi-distributed hydrological model that originally assumes no water movement in frozen soil layers, by incorporating the dynamic change of soil permeability based on the degree of soil freezing, and to understand the effect of water movement in frozen soil on watershed hydrology. SWAT with frozen soil permeability (SWAT-FSP) was developed by adding two modules to the original SWAT: a heat conduction equation that considers the phase change of ice and liquid water and a frozen-soil percolation model that considers dynamic decrease in soil permeability due to soil freezing. The original SWAT and SWAT-FSP were set up in the Tokoro River watershed in northern Japan. The river flow and soil water dynamics during the snowmelt period (March–May) simulated using the original SWAT and SWAT-FSP were compared. The modified model significantly alters the soil water dynamics simulation to generate earlier soil water drainage and reduces the soil water content during the snowmelt period in years featuring weak soil freezing. Consequently, the SWAT-FSP estimated an earlier increase in river flow at the beginning of the snowmelt period and a smaller river flow in the middle of the snowmelt period as compared with the original SWAT. The modified model improved the overall performance in river flow simulation for the snowmelt period (March–May) of 2012–2019. The Nash-Sutcliffe efficiency obtained during the calibration period by the original SWAT was 0.602, and during the validation period it was 0.367. For the SWAT-FSP, it was 0.659 during calibration, and 0.639 during validation. Meanwhile, the SWAT-FSP showed unsatisfactory performance in 2014 and 2015, with underestimated snow water equivalent, indicating that improvements in the snowmelt/accumulation module may further enhance its accuracy. Our results showed that the dynamic change of soil permeability governed by the degree of soil freezing is an important factor affecting the water cycle of cold climate watersheds with seasonally frozen soil.

Expression and functional analysis of a recombinant aquaporin Z from Antarctic Pseudomonas sp. AMS3.

Aquaporin (AQP) is a water channel protein from the family of transmembrane proteins which facilitates the movement of water across the cell membrane. It is ubiquitous in nature, however the understanding of the water transport mechanism, especially for AQPs in microbes adapted to low temperatures, remains limited. AQP also has been recognized for its ability to be used for water filtration, but knowledge of the biochemical features necessary for its potential applications in industrial processes has been lacking. Therefore, this research was conducted to express, extract, solubilize, purify, and study the functional adaptations of the aquaporin Z family from Pseudomonas sp. AMS3 via molecular approaches. In this study, AqpZ1 AMS3 was successfully subcloned and expressed in E. coli BL21 (DE3) as a recombinant protein. The AqpZ1 AMS3 gene was expressed under optimized conditions and the best optimized condition for the AQP was in 0.5 mM IPTG incubated at 25°C for 20 h induction time. A zwitterionic mild detergent [(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate was the suitable surfactant for the protein solubilization. The protein was then purified via affinity chromatography. Liposome and proteoliposome was reconstituted to determine the particle size using dynamic light scattering. This information obtained from this psychrophilic AQP identified provides new insights into the structural adaptation of this protein at low temperatures and could be useful for low temperature application and molecular engineering purposes in the future.

Zinc and silicon fertilizers in conventional and nano‐forms: Mitigating salinity effects in maize (Zea mays L.)

AbstractBackgroundSalinity stress, an escalating concern in the realm of agriculture, significantly hampers crop productivity worldwide. In recent years, nano‐fertilizers have been identified as an innovative and promising avenue for improving nutrient use efficiency and mitigating salt stress in plants.AimsThis study delves into the comparative efficacy of nano‐fertilizers (Zn and Si) and their conventional sources in bolstering maize's resilience against salt stress.MethodsThe hydroponic experiment was conducted to test maize plants under salt stress along with Zn and Si nanoparticles (NPs) application. The analysis extends to their impacts on ionic homeostasis, specifically focusing on potassium and sodium concentrations, K/Na ratio, stomatal conductance, chlorophyll content, and the osmotic potential (OP) within the shoots and roots of maize.ResultsNanoparticles relatively helped plants better under stress, compared to their respective bulk mode of applications. Nano‐Zn treatment considerably boosts the K+ concentration and enhanced K/Na ratio, as a key physiological trait in salt‐resistant species, while nano‐Si demonstrates a prominent role in modulating OP and limiting Na+ accumulation along with higher Zn and Si accumulation in plants. The salt tolerance index confirmed the contribution of these ionic and osmotic adjustments in helping maize plant against salt stress.ConclusionsOur findings confirm that the application of nutrients as nano‐fertilizers, particularly nano‐Zn, enhanced K/Na ratio and improved nutrient availability and uptake of the plant. Si nanoparticles are also attributed to better osmotic adjustment and facilitating water movement, thus highlighting the potential of nano‐fertilizers in improving overall agricultural productivity and related environmental issues.

Multiple isotopes reveal the impact of land use change on nitrate transport and transformation in deep loess deposits

The deep-rooted economic trees decrease water storage but increase nitrate-nitrogen (NO3–N) accumulation in the soil due to the root water uptake and excessive use of fertilizers. Knowing how the NO3 accumulates in the soil and to what extent it can be flushed out or transformed can provide insights on the processes controlling N flux to waterways. We sampled cultivated farmland and orchards with varying ages of apple and peach trees in the loess deposits to > 15 m depth to measure the contents and isotopes of water and NO3 in soils. The novelty of this study is that the water isotopes are used to analyze water and NO3 transport, while the NO3 isotopes are further employed for NO3 source and transformation analysis. The parabolic NO3–N profiles (258–3579 kg N ha−1) were mainly observed within 0–5 m under different land use types. The surface-aggregated NO3 reservoirs under old apple orchard were about six times of farmland due to the overuse of chemical fertilizers, while those of peach orchard were only half of farmland because of less fertilizer inputs and possible root absorption effects. Piston flow resulted in the overall slow water movement and low NO3 flux under different land use types in deep loess deposits. Despite the soil water recharge by precipitation and low surface evaporation, the strong transpiration effects further resulted in no water and NO3 fluxes in the deep layers under old apple orchard. Nitrate reservoirs were mainly contributed by soil organic N (44 % ± 26 %) and ammonium N fertilizer (36 % ± 20 %), but their transformation was dominated by nitrification under old apple orchard and by mineralization in deep layers. The risks of NO3 bombs are temporarily weakened by lower dried soil layers under deep rooted plants; however, with lower water movement rates and limited denitrification potential, NO3 would eventually reach the aquifers in a few hundred years or more. This study provides new insights for clarifying NO3 transport and transformation processes by combing multiple isotopes, and the NO3 bombs would chronically endanger the sustainable development of terrestrial ecosystems and the environment in arid regions.

Measuring and modeling of liquid water transport in a carbon paper with the aid of centrifuge experiment

In previous macroscopic average models of proton exchange membrane fuel cells (PEMFCs), liquid water was assumed to be continuous throughout the carbon paper. The transport of disconnected water drops in carbon paper has long been neglected in these models, which tend to underestimate water saturation in carbon paper. This study proposes a two-phase flow model that considers the transport of disconnected water drops to simulate the air-water transport in carbon paper. The proposed model was established based on the relationship between capillary force and liquid water saturation, and this relationship was obtained by conducting centrifuge experiments. In the centrifuge experiment, initially, the water saturation inside the carbon paper sample was one, and the centrifugal acceleration was zero. As the centrifugal acceleration increased, the water saturation decreased owing to the centrifugal force. After twenty seconds, the water saturation no longer decreases because the centrifugal force on the liquid water is balanced by the capillary force. Centrifugal acceleration was used to evaluate the capillary force. When the centrifugal acceleration was 185 ms−2, the saturation of the water drops in the balanced state was 32.0%. As the centrifugal acceleration increases to 739 ms−2, the saturation decreases to 6.5%. According to the experimental results, a function correlating the saturation and centrifugal acceleration, that is, the capillary force, was established. Finally, the results show that the centrifugal acceleration is more than 18.5 times that of the gravitational acceleration, indicating that the effect of gravity on the motion of water drops is negligible.

Numerical Study of Pore Water Pressure in Frozen Soils during Moisture Migration

Frost heaving in soils is a primary cause of engineering failures in cold regions. Although extensive experimental and numerical research has focused on the deformation caused by frost heaving, there is a notable lack of numerical investigations into the critical underlying factor: pore water pressure. This study aimed to experimentally determine changes in soil water content over time at various depths during unidirectional freezing and to model this process using a coupled hydrothermal approach. The agreement between experimental water content outcomes and numerical predictions validates the numerical method’s applicability. Furthermore, by applying the Gibbs free energy equation, we derived a novel equation for calculating the pore water pressure in saturated frozen soil. Utilizing this equation, we developed a numerical model to simulate pore water pressure and water movement in frozen soil, accounting for scenarios with and without ice lens formation and quantifying unfrozen water migration from unfrozen to frozen zones over time. Our findings reveal that pore water pressure decreases as freezing depth increases, reaching near zero at the freezing front. Notably, the presence of an ice lens significantly amplifies pore water pressure—approximately tenfold—compared to scenarios without an ice lens, aligning with existing experimental data. The model also indicates that the cold-end temperature sets the maximum pore water pressure value in freezing soil, with superior performance to Konrad’s model at lower temperatures in the absence of ice lenses. Additionally, as freezing progresses, the rate of water flow from the unfrozen region to the freezing fringe exhibits a fluctuating decline. This study successfully establishes a numerical model for pore water pressure and water flow in frozen soil, confirms its validity through experimental comparison, and introduces an improved formula for pore water pressure calculation, offering a more accurate reflection of the real-world phenomena than previous formulations.

Characterization and prediction of soil hydraulic and solute transport parameters using a random forest model

AbstractTo effectively control nonpoint source pollution and predict its transport and load, understanding water and solute transport processes, patterns and mechanisms is essential. However, the measurement of water movement and solute transport parameters is usually a laborious and time‐consuming task. It is important to predict water movement and solute transport parameters from more readily available soil physical and chemical properties. In this study, a database of soil hydraulic and solute transport parameters containing information retrieved from 83 published studies on soil properties, land use, management measures, etc. was established to characterize and simulate soil water movement and solute transport processes. Our results showed that the soil particle composition was closely related to all soil hydraulic and solute transport parameters. As the soil texture changed from sand to clay, the soil residual water content (θr) obviously increased. The soil porosity was significantly positively correlated with θr, saturated water content (θs), van Genuchten parameter α, dispersity (λ) and retardation factor (R) and negatively correlated with van Genuchten parameter n (p < 0.01). The use of random forest models allowed the prediction of soil hydraulic and solute transport parameters by inputting common or even incomplete soil property parameters. The bulk density and particle composition jointly contributed 66% to the prediction of the soil hydraulic parameters and 44% to the prediction of the solute transport parameters. The pH exerted a notable impact on the solute transport parameters, especially dispersion coefficient (D), λ and R. The results may be useful in providing data support and facilitating the development of watershed nonpoint source pollution models.

Effect of Parenchymal Arachnoid on Brain Fluid Transport.

The pia-arachnoid is a critical component of cerebrospinal fluid removal. It covers and invaginates into the brain parenchyma, and physiologic failure results in hydrocephalus and cerebral edema. The purpose of this study was to characterize the role of arachnoid within brain parenchyma and determine if water flux and solute transport are affected by these intra-parenchymal cells. An immortalized arachnoid rat cell line was used to seed 300-μm organotypic rat brain slices of 4-week-old rats. Fluid and tracer transport analyses were conducted following a 7-10 day intraparenchymal growth period. The development of an arachnoid brain slice model was characterized using diffusion chamber experiments to calculate permeability, diffusion coefficient, and flux. Labeled rat arachnoid cells readily penetrated organotypic cultures for up to 10 days. A significant reduction of dye and water flux across arachnoid-impregnated brain slices was observed after 3 hours in the diffusion chamber. Permeability decreased in whole brain slices containing arachnoid cells compared to slices without arachnoid cells. In comparison, a significant reduction of dextran across all slices occurred when molecular weights increased from 40 to 70 kDa. Tracer and small molecule studies show that arachnoid cells' presence significantly impacts water's movement through brain parenchyma. Size differential experiments indicate that the permeability of solute changed substantially between 40 and 70 kDa, an essential marker of blood-CSF barrier definition. We have developed an arachnoid organotypic model that reveals their ability to alter permeability and transport.

Exploratory neutron tomography of articular cartilage

To investigate the feasibility of using neutron tomography to gain new knowledge of human articular cartilage degeneration in osteoarthritis (OA). Different sample preparation techniques were evaluated to identify maximum intra-tissue contrast. Human articular cartilage samples from 14 deceased donors (18-75 years, 9 males, 5 females) and 4 patients undergoing total knee replacement due to known OA (all female, 61-75 years) were prepared using different techniques: control in saline, treated with heavy water saline, fixed and treated in heavy water saline, and fixed and dehydrated with ethanol. Neutron tomographic imaging (isotropic voxel sizes from 7.5 to 13.5µm) was performed at two large scale facilities. The 3D images were evaluated for gradients in hydrogen attenuation as well as compared to images from absorption X-ray tomography, magnetic resonance imaging, and histology. Cartilage was distinguishable from background and other tissues in neutron tomographs. Intra-tissue contrast was highest in heavy water-treated samples, which showed a clear gradient from the cartilage surface to the bone interface. Increased neutron flux or exposure time improved image quality but did not affect the ability to detect gradients. Samples from older donors showed high variation in gradient profile, especially from donors with known OA. Neutron tomography is a viable technique for specialized studies of cartilage, particularly for quantifying properties relating to the hydrogen density of the tissue matrix or water movement in the tissue.

Wide-characterization of high and low dry matter kiwifruit through spatiotemporal multi-omic approach

Despite the widespread use of dry matter content (DMC) as an indicator of kiwifruit quality, the physiological and molecular impact of DMC in fruit ripening remains unknown. Herein, the post-harvest physiological, metabolomic, and transcriptomic influence of DMC status on the pericarp and placenta tissue of ‘Hayward’ kiwifruit at harvest and at the onset of post-cold ripening was investigated. A segregation strategy based on DMC in commercially harvested kiwifruit was achieved with near-infrared spectroscopy for the estimation of DMC in individual fruits. Additionally, kiwifruits with distinct DMC levels were treated with 1-methylcyclopropene (1-MCP) and systematically monitored for ripening changes (20°C) at various intervals after cold storage (0°C). Following 90 and 120 days of cold exposure, high DMC kiwifruit generally exhibited superior physiological characteristics, such as increased pericarp and placenta firmness, and soluble solid and starch contents compared to low DMC kiwifruit, regardless of the 1-MCP application. Evidence is also presented for 1-MCP delaying the ripening of low-DMC fruit to the level of the untreated high-DMC kiwifruit. An accumulation of primary metabolites, particularly sugars and polyphenolic compounds, such as catechin, chlorogenic acid and procyanidin B1/B2 was evidenced in the high DMC group. At harvest, gene expression analysis revealed minor differences between DMC groups, with beta-amylase being the highest up-regulated gene in high DMC kiwifruit. Moreover, the gene expression patterns between DMC groups became more distinct after cold storage. Genes related to starch biosynthesis (i.e., glucose-1-phosphate adenyltransferase), water movement (i.e., aquaporin), polyphenolic biosynthesis (i.e., chalcone synthase) and lipid metabolism (i.e., diacylglycerol acyltransferase) showed strong variations between low and high DMC. Interestingly, the placenta tissue displayed almost 4 times more than DMC-affected differentially expressed genes compared to the pericarp, highlighting the key role of the placenta in kiwifruit ripening, notably following 1-MCP treatment. This study provides insights into the tissue-specific ripening response between kiwifruit with distinct DMC, as well as the gene expression influenced by an interaction of 1-MCP and DMC level, thereby helping develop postharvest programs aimed at improving kiwifruit quality traits.