Assessment of a green roof practice using the coupled SWMM and HYDRUS models.

Green roof can mitigate urban stormwater and improve environmental, economic, and social conditions. Various modeling approaches have been effectively employed to implement a green roof, but previous models employed simplifications to simulate water movement in green roof systems. To address this issue, we developed a new modeling tool (SWMM-H) by coupling the stormwater management and HYDRUS-1D models to improve simulations of hydrological processes. We selected green roof systems to evaluate the coupled model. Rainfall-runoff experiments were conducted for a pilot-scale green roof and urban subbasin. Soil moisture in the green roof and runoff volume in the subbasin were simulated more accurately by using SWMM-H instead of SWMM. The scenario analysis showed that SWMM-H selected sandy loam for controlling runoff whereas SWMM recommended sand. In conclusion, SWMM-H could be a useful tool for accurately understanding hydrological processes in green roofs.

External water transport is more important than vascular transport in the extreme atmospheric epiphyte Tillandsia usneoides (Spanish moss).

Most epiphytic bromeliads, especially those in the genus Tillandsia, lack functional roots and rely on the absorption of water and nutrients by large, multicellular trichomes on the epidermal surfaces of leaves and stems. Another important function of these structures is the spread of water over the epidermal surface by capillary action between trichome "wings" and epidermal surface. Although critical for the ultimate absorption by these plants, understanding of this function of trichomes is primarily based on light microscope observations. To better understand this phenomenon, the distribution of water was followed by its attenuation of cold neutrons following application of H2 O to the cut end of Tillandsia usneoides shoots. Experiments confirmed the spread of added water on the external surfaces of this "atmospheric" epiphyte. In a morphologically and physiologically similar plant lacking epidermal trichomes, water added to the cut end of a shoot clearly moved via its internal xylem and not on its epidermis. Thus, in T. usneoides, water moves primarily by capillarity among the overlapping trichomes forming a dense indumentum on shoot surfaces, while internal vascular water movement is less likely. T. usneoides, occupying xeric microhabitats, benefits from reduction of water losses by low-shoot xylem hydraulic conductivities.

Sensory ecology of the fish lateral-line system: Morphological and physiological adaptations for the perception of hydrodynamic stimuli.

Fishes are able to detect and perceive the hydrodynamic and physical environment they inhabit and process this sensory information to guide the resultant behaviour through their mechanosensory lateral-line system. This sensory system consists of up to several thousand neuromasts distributed across the entire body of the animal. Using the lateral-line system, fishes perceive water movements of both biotic and abiotic origin. The anatomy of the lateral-line system varies greatly between and within species. It is still a matter of debate as to how different lateral-line anatomies reflect adaptations to the hydrodynamic conditions to which fishes are exposed. While there are many accounts of lateral-line system adaptations for the detection of hydrodynamic signals in distinct behavioural contexts and environments for specific fish species, there is only limited knowledge on how the environment influences intra and interspecific variations in lateral-line morphology. Fishes live in a wide range of habitats with highly diverse hydrodynamic conditions, from pools and lakes and slowly moving deep-sea currents to turbulent and fast running rivers and rough coastal surf regions. Perhaps surprisingly, detailed characterisations of the hydrodynamic properties of natural water bodies are rare. In particular, little is known about the spatio-temporal patterns of the small-scale water motions that are most relevant for many fish behaviours, making it difficult to relate environmental stimuli to sensory system morphology and function. Humans use bodies of water extensively for recreational, industrial and domestic purposes and in doing so often alter the aquatic environment, such as through the release of toxicants, the blocking of rivers by dams and acoustic noise emerging from boats and construction sites. Although the effects of anthropogenic interferences are often not well understood or quantified, it seems obvious that they change not only water quality and appearance but also, they alter hydrodynamic conditions and thus the types of hydrodynamic stimuli acting on fishes. To date, little is known about how anthropogenic influences on the aquatic environment affect the morphology and function of sensory systems in general and the lateral-line system in particular. This review starts out by briefly describing naturally occurring hydrodynamic stimuli and the morphology and neurobiology of the fish lateral-line system. In the main part, adaptations of the fish lateral-line system for the detection and analysis of water movements during various behaviours are presented. Finally, anthropogenic influences on the aquatic environment and potential effects on the fish lateral-line system are discussed.

Role of Aquaporins in a Composite Model of Water Transport in the Leaf.

Water-transport pathways through the leaf are complex and include several checkpoints. Some of these checkpoints exhibit dynamic behavior that may be regulated by aquaporins (AQPs). To date, neither the relative weight of the different water pathways nor their molecular mechanisms are well understood. Here, we have collected evidence to support a putative composite model of water pathways in the leaf and the distribution of water across those pathways. We describe how water moves along a single transcellular path through the parenchyma and continues toward the mesophyll and stomata along transcellular, symplastic and apoplastic paths. We present evidence that points to a role for AQPs in regulating the relative weight of each path in the overall leaf water-transport system and the movement of water between these paths as a result of the integration of multiple signals, including transpiration demand, water potential and turgor. We also present a new theory, the hydraulic fuse theory, to explain effects of the leaf turgor-loss-point on water paths alternation and the subsequent reduction in leaf hydraulic conductivity. An improved understating of leaf water-balance management may lead to the development of crops that use water more efficiently, and responds better to environmental changes.

Flow and geochemical modeling of drainage from Tomitaka mine, Miyazaki, Japan.

The chemistry and flow of water in the abandoned Tomitaka mine of Miyazaki, western Japan were investigated. This mine is located in a non-ferrous metal deposit and acid mine drainage issues from it. The study was undertaken to estimate the quantities of mine drainage that needs to be treated in order to avoid acidification of local rivers, taking into account seasonal variations in rainfall. Numerical models aimed to reproduce observed water levels and fluxes and chemical variations of groundwater and mine drainage. Rock-water interactions that may explain the observed variations in water chemistry are proposed. The results show that: (1) rain water infiltrates into the deeper bedrock through a highly permeable zone formed largely by stopes that are partially filled with spoil from excavations (ore minerals and host rocks); (2) the water becomes acidic (pH from 3 to 4) as dissolved oxygen oxidizes pyrite; (3) along the flow path through the rocks, the redox potential of the water becomes reducing, such that pyrite becomes stable and pH of the mine drainage becomes neutral; and (4) upon leaving the mine, the drainage becomes acidic again due to oxidation of pyrite in the rocks. The present numerical model with considering of the geochemical characteristics can simulate the main variations in groundwater flow and water levels in and around the Tomitaka mine, and apply to the future treatment of the mine drainage.

Against the odds: complete outcrossing in a monoecious clonal seagrass Posidonia australis (Posidoniaceae).

BACKGROUND AND AIMS: Seagrasses are marine, flowering plants with a hydrophilous pollination strategy. In these plants, successful mating requires dispersal of filamentous pollen grains through the water column to receptive stigmas. Approximately 40 % of seagrass species are monoecious, and therefore little pollen movement is required if inbreeding is tolerated. Outcrossing in these species is further impacted by clonality, which is variable, but can be extensive in large, dense meadows. Despite this, little is known about the interaction between clonal structure, genetic diversity and mating systems in hydrophilous taxa. METHODS: Polymorphic microsatellite DNA markers were used to characterize genetic diversity, clonal structure, mating system and realized pollen dispersal in two meadows of the temperate, monoecious seagrass, Posidonia australis, in Cockburn Sound, Western Australia. KEY RESULTS: Within the two sampled meadows, genetic diversity was moderate among the maternal shoots (R = 0·45 and 0·64) and extremely high in the embryos (R = 0·93-0·97). Both meadows exhibited a highly clumping (or phalanx) structure among clones, with spatial autocorrelation analysis showing significant genetic structure among shoots and embryos up to 10-15 m. Outcrossing rates were not significantly different from one. Pollen dispersal distances inferred from paternity assignment averaged 30·8 and 26·8 m, which was larger than the mean clone size (12·8 and 13·8 m). CONCLUSIONS: These results suggest highly effective movement of pollen in the water column. Despite strong clonal structure and moderate genetic diversity within meadows, hydrophilous pollination is an effective vector for completely outcrossed offspring. The different localized water conditions at each site (highly exposed conditions vs. weak directional flow) appear to have little influence on the success and pattern of successful pollination in the two meadows.

Immunolocalization of aquaporins 1, 3, and 5 in the nasal respiratory mucosa of a panting species, the sheep (Ovis aries).

The nasal respiratory mucosa is the primary site for evaporative water loss in panting species, necessitating the movement of water across the nasal epithelium. Aquaporins (AQP) are protein channels that facilitate water movement in various fluid transporting tissues of non-panting species. Whether the requirement for enhanced capacity for transepithelial water movement in the nasal respiratory mucosa of panting species has led to differences in AQP localization is unknown. Using immunohistochemistry, we report the localization of AQP1, 3, and 5 in the nasal respiratory mucosa of sheep being exposed to ambient temperatures of ~21 °C or ~38 °C for 4.5 h before death (n=3/treatment). Exposure to either treatment resulted in panting. While exposure to ~38 °C resulted in a higher respiratory frequency (mean difference: 82 breaths min(-1); P<0.001) than exposure to ~21 °C, there was no difference in the localization of AQPs. Connective tissue and vascular endothelial cells expressed AQP1. Glandular acini expressed AQP1 and apically localized AQP5, which was also present in glandular duct cells. Ciliated columnar epithelial cells expressed AQP5 apically and AQP3 basolaterally. Basal cells expressed AQP3. The distribution and co-localization of AQPs in the ovine nasal respiratory mucosa is different to that reported in non-panting species and may reflect the physiological demands associated with enhanced respiratory evaporation. We propose that AQP1, 3, and 5 may constitute a transepithelial water pathway via glandular secretions and across the surface epithelium, which provides a possible means for rapid and controllable water movement in the nasal respiratory mucosa of a panting species.

Homeostatic status of thyroid hormones and brain water movement as determinant factors in biology of cerebral gliomas: a pilot study using a bioinformatics approach.

Introduction: The expression and localization of the water channel transporters, aquaporins (AQPs), in the brain are substantially modified in gliomas during tumorigenesis, cell migration, edema formation, and resolution. We hypothesized that the molecular changes associated with AQP1 and AQP4 in the brain may potentially be anticancer therapeutic targets. To test this hypothesis, a bioinformatics analysis of publicly available data from international consortia was performed. Methods: We used RNA-seq as an experimental strategy and identified the number of differential AQP1 and AQP4 transcript expressions in glioma tissue compared to normal brain tissue. Results: AQPs genes are overexpressed in patients with glioma. Among the glioma subtypes, AQP1 and AQP4 were overexpressed in astrocytoma (low-grade glioma) and classical (high-grade glioma). Overall survival analysis demonstrated that both AQP genes can be used as prognostic factors for patients with low-grade glioma. Additionally, we observed a correlation between the expression of genes involved in the tyrosine and thyroid hormone pathways and AQPs, namely: PNMT, ALDH1A3, AOC2, HGDATP1B1, ADCY5, PLCB4, ITPR1, ATP1A3, LRP2, HDAC1, MED24, MTOR, and ACTB1 (Spearman's coefficient = geq 0.20 and p-value = ≤ 0.05). Conclusion: Our findings indicate that the thyroid hormone pathways and AQPs 1 and 4 are potential targets for new anti-tumor drugs and therapeutic biomarkers for malignant gliomas.

The ecology, behaviour and physiology of fishes on coral reef flats, and the potential impacts of climate change.

Reef flats, typically a low-relief carbonate and sand habitat in shallow water leeward of the reef crest, are one of the most extensive zones on Pacific coral reefs. This shallow zone often supports an abundant and diverse fish assemblage that is exposed to more significant variations in physical factors, such as water depth and movement, temperature and ultraviolet (UV) radiation levels, than most other reef fishes. This review examines the characteristics of reef flat fish assemblages, and then investigates what is known about how they respond to their biophysical environment. Because of the challenges of living in shallow, wave-exposed water, reef flats typically support a distinct fish assemblage compared to other reef habitats. This assemblage clearly changes across tidal cycles as some larger species migrate to deeper water at low tide and other species modify their behaviour, but quantitative data are generally lacking. At least some reef flat fish species are well-adapted to high temperatures, low oxygen concentrations and high levels of UV radiation. These behavioural and physiological adaptations suggest that there may be differences in the demographic processes between reef flat assemblages and those in deeper water. Indeed, there is some evidence that reef flats may act as nurseries for some species, but more research is required. Further studies are also required to predict the effects of climate change, which is likely to have multifaceted impacts on reef flats by increasing temperature, water motion and sediment load. Sea-level rise may also affect reef flat fish assemblages and food webs by increasing the amount of time that larger species are able to forage in this zone. The lack of data on reef flats is surprising given their size and relative ease of access, and a better understanding of their functional role within tropical marine seascapes is urgently required.

Effects of upstream activities of Tigris-Euphrates River Basin on water and soil resources of Shatt al-Arab Border River.

The Tigris-Euphrates River Basin (TERB) is one of the key transboundary basins among the developing countries in the Middle East which has been significantly damaged by mismanagement, exploitation for energy production and unsustainable water use. This study aimed to evaluate the water and soil resources in the lower parts of this basin. More specifically, how the area of the Shatt al-Arab River (SAR) formed at the confluence of the Tigris and Euphrates rivers is affected in terms of quality by upstream activities. Four mathematical models of hydrodynamics, advection-dispersion in the river, and convection-dispersion in soil were used in conjunction with assessment of soil salinization by irrigation water. The soil salinization based on direct saltwater infiltration from riverbanks and soil salinization by irrigation with river water were predicted after simulating the intrusion of saline seawater by considering the tidal conditions of the SAR. The results showed that by applying six optimistic and probable scenarios of freshwater inflows for the future, changes in the water and soil quality in downstream riparian countries (Iran and Iraq) reflect this basin's developments and water allocation upstream. Regarding the possible scenario of maximum inflow reduction in the future, the findings of this study can be used to create a comprehensive view of the current condition and development challenges. This emphasizes the need for participatory crisis mitigation strategies between the upstream and downstream countries.

[Effects of exogenous attapulgite addition on water conservation function of reclaimed soils in a semi-arid mining area]. / å¤–æºå‡¹å‡¸æ£’åœŸæ·»åŠ å¯¹åŠå¹²æ—±çŸ¿åŒºå¤åž¦åœŸå£¤æ°´åˆ†æ¶µå »åŠŸèƒ½çš„å½±å“.

Large-scale mining has greatly damaged vegetation and caused ecological degradation in the semi-arid area in China. It is urgent to restore the vegetation to solve the deteriorating ecological and environmental problems in mining area. How to reclaim soils for effectively storing and utilizing precipitation is the primary issue for vegetation restoration in the area. In this study, we proposed to take the mixture of attapulgite clay and local sandy soils as covering materials to improve the weak water conservation function of soils in mining areas, and studied the effects of the addition of attapulgite clay on soil infiltration, drainage and water storage sampled from the Shenmu mining area. The results showed that, with increasing application rates of attapulgite clay, the cumulated infiltration volumes decreased by 4.8%-37.4%, the infiltration rates dropped by 6.4%-46.3%, the wetting front advance rates decreased by 9.8%-116.9%, the saturated hydraulic conductivities decreased by 14.3%-59.5%, the drained water volumes reduced by 0.3%-4.3% for 24 hours and by 0.3%-2.5% for 72 hours, and the maximum soil water storages increased by 1.6%-22.4%. The maximum effect of attapulgite clay peaked at the application rate of 150 t·hm-2. Considering the economic cost, the optimum application rate should be 30-150 t·hm-2. The results syste-matically revealed the mechanism of reclaiming mining soils with attapulgite clay to restore the function of water conservation, and demonstrated that attapulgite clay is an effective material for soil reclamation in the semi-arid mining area, which can provide references for soil reclamation and ecological restoration in the semi-arid mining area.

Effect of Sodium Carboxymethyl Cellulose on Water and Salt Transport Characteristics of Saline-Alkali Soil in Xinjiang, China.

The scientific use of sodium carboxymethyl cellulose (CMC) to improve the production capacity of saline-alkali soil is critical to achieve green agriculture and sustainable land use. It serves as a foundation for the scientific use of CMC to clarify the water and salt transport characteristics of CMC-treated soil. In this study, a one-dimensional soil column infiltration experiment was carried out to investigate the effects of different CMC dosages (0, 0.2, 0.4, 0.6, and 0.8 g/kg) on the infiltration characteristics, infiltration model parameters, water and salt distribution, and salt leaching of saline-alkali soil in Xinjiang, China. The results showed that the final cumulative infiltration of CMC-treated soil increased by 8.63-20.72%, and the infiltration time to reach the preset wetting front depth increased by 1.02-3.96 times. The sorptivity (S) in the Philip infiltration model and comprehensive shape coefficient (α) in the algebraic infiltration model showed a trend of increasing first and then decreasing with CMC dosage, revealing a quadratic polynomial relationship. The algebraic model could accurately simulate the water content profile of CMC-treated soil. CMC enhanced the soil water holding capacity and salt leaching efficiency. The average soil water content, desalination rate, and leaching efficiency were increased by 5.18-15.54%, 21.17-57.15%, and 11.61-30.18%, respectively. The effect of water retention and salt inhibition on loamy sand was the best when the CMC dosage was 0.6 g/ kg. In conclusion, the results provide a theoretical basis for the rational application of CMC to improve saline-alkali soil in arid areas.

Acute Physiological Response of Lumbar Intervertebral Discs to High-load Deadlift Exercise.

PURPOSE: We aimed to evaluate the acute physiological effects of high-load deadlift exercise on the lumbar intervertebral discs using MR diffusion-weighted imaging (DWI). METHODS: Fifteen volunteers (11 men and 4 women; 23.2 ± 3.3 years) without lumbar intervertebral disc degeneration performed deadlift exercise (70% of 1 repetition maximum, 6 repetitions, 5 sets, 90 s rest between sets) using a Smith machine. Sagittal MR diffusion-weighted images of the lumbar intervertebral discs were obtained using a 1.5-Tesla MR system with a spine coil before and immediately after the exercise. We calculated apparent diffusion coefficient (ADC; an index of water movement) of the nucleus pulposus from diffusion weighted images at all lumbar intervertebral discs (L1/2 through L5/S1). RESULTS: All lumbar intervertebral discs showed significantly decreased ADC values immediately after deadlift exercise (L1/2, -2.8%; L2/3, -2.1%; L3/4, -2.8%; L4/5, -4.9%; L5/S1, -6.2%; P < 0.01). In addition, the rate of ADC decrease of the L5/S1 disc was significantly greater than those of the L1/2 (P = 0.017), L2/3 (P < 0.01), and L3/4 (P = 0.02) discs. CONCLUSION: The movement of water molecules within the lumbar intervertebral discs is suppressed by high-load deadlift exercise, which would be attributed to mechanical stress on the lumbar intervertebral discs during deadlift exercise. In particular, the L5/S1 disc is subjected to greater mechanical stress than the other lumbar intervertebral discs.

Chloride tracer of the loess unsaturated zone under sub-humid region: A potential proxy recording high-resolution hydroclimate.

A high-resolution hydroclimate archive is critical to understanding the past changes, but such hydroclimatic reconstructions are extremely limited. Our study aims to examine the potential of the chloride tracer (Cl) within unsaturated zone (USZ) to reconstruct high-resolution hydroclimate records. We investigated a representative sub-humid monsoon area of the Chinese Loess highland, where piston flow recharge dominates and a constant rate of Cl input occurs. We successfully reconstructed a 1007-yr hydroclimate record with a 2-yr sampling resolution using a 95-m USZ Cl profile. Excluding the recycling and mixing zone, and the groundwater affecting zone, six relatively humid phases and five relatively dry phases were discernible. The uncertainty in the time of wet/dry phase decreases as the accumulated time increases, and the minimal recharge uncertainty is 16% over a 10-yr time scale. The reconstructed hydroclimate record from the semi-humid region has a much higher resolution than that of the arid zones, likely because the semi-humid, fine-grained thick USZ, possesses higher velocity piston flow, relatively to diffusion and dispersion of Cl signals. The record compared well with other related records, suggesting that the Cl proxy can be used in sub-humid areas, and is sensitive to wet/dry alternations that are largely driven by the Asian monsoon intensity. To the best of our knowledge, this is the first investigation of the USZ Cl to hydroclimatic reconstruction in a non-arid region. The high-resolution hydroclimate record may deepen our understanding of the hydrological process in the deep USZ, past climate and water resources, and promote developments of the hydropedology and global change science.

[Oxygen and hydrogen stable isotope compositions of soil water in deep loess profile under different land use types of northern Shaanxi, China]. / é™•åŒ—é»„åœŸåŒºæ·±å‰–é¢ä¸åŒåœŸåœ°åˆ©ç”¨æ–¹å¼ä¸‹åœŸå£¤æ°´æ°¢æ°§ç¨³å®šåŒä½ç´ ç‰¹å¾.

Investigation of stable isotope composition under different land use types is helpful for understanding soil water movement and hydrological effects of land use change. We collected soil samples in profiles ＞ 15 m deep under four land use types (i.e. farmland, grassland, Salix cheilophila and Populus sp.) in the loess deposits of northern Shaanxi. We measured hydrogen and oxygen stable isotope composition of soil water to explore the mechanism of soil water movement and the impacts of land use types. The isotope compositions of soil water under four land use types were significantly different. The δD values of soil water under farmland, grassland, S. cheilophila and Populus sp. were -81.1‰--60.1‰, -91.2‰--61.0‰, -87.4‰--63.6‰ and -73.5‰--62.2‰, while the δ18O values were -11.2‰--7.6‰, -12.6‰--8.2‰, -11.5‰--8.1‰ and -9.9‰--7.7‰, respectively. The soil water stable isotopes fluctuated across the profiles. The soil water isotope compositions in the layers of 0-3 m changed sharply, with the δD values being -80.2‰--61.8‰, -75.9‰--65.5‰, -76.0‰--63.6‰ and -73.5‰--62.2‰, respectively. In the layers of 3-12 m, the isotope profiles of farmland and grassland were parabolic, whereas those of S. cheilophila and Populus sp. were relatively stable. Soil water isotope compositions in the layers deeper than 12 m were generally stable with the δD values of -80.8‰--71.5‰, -83.0‰--67.5‰, -87.4‰--76.0‰ and -67.5‰--64.3‰, respectively. Across the four land use types, soil water stable isotope compositions were not significantly different either in the shallow layers or in the deep soil layers, but their differences in the layers of 3-12 m were significant. Soil moisture was mainly recharged from precipitation with piston flow as the main form of soil water movement. Soil water under four land use types might be recharged by wet events of different intensities. Soil water under farmland and grassland could be recharged by wet events of small intensity, but that under S. cheilophila and Populus sp. may be mainly recharged by the rainstorm in summer and autumn.

[Effects of conservation tillage measures on soil water and NO3--N leaching in dryland maize cropland]. / 保护性耕作措施对旱地春玉米土壤水分和硝态氮淋溶累积的影响.

Based on a field experiment on conservation tillage over 15 years in Weibei Highland maize cropland, six conservation tillage patterns, i.e., conventional tillage (CT), no-tillage (NT), no-tillage plus biochar (NB), no-tillage and straw mulching (NS), no-tillage and plastic film mulching (NF), and no-tillage and straw-plastic film mulching (NSF), were investigated for their effects on soil water and nitrate nitrogen(NO3--N) leaching, to seek sustainable agricultural cultivation measures suitable for the region. Results showed that, compared with NT treatment in the first water recharge period, CT had no effect on water recharge in 0-100 cm soil layer, and NS, NB, NSF and NF significantly reduced soil water recharge. In 100-300 cm soil layer, NS, NB, NF and NSF significantly increased soil water recharge, but CT significantly reduced soil water recharge. During the second water recharge period, water recharge depth was mainly concentrated in 0-100 cm soil layer, and there was no significant difference between each treatment and NT. During the water depletion period, compared with NT treatment, other treatments had no significant effect on water depletion in 0-100 cm soil layer, but NF and NSF increased soil water depletion by 33.9% and 59.9% in 100-300 cm soil layer, respectively. In 0-200 cm soil layer, compared to NT, CT significantly increased the accumulation of NO3--N by 2.2 fold, NS, NB, NF and NSF reduced soil NO3--N accumulation by 44.6%, 61.5%, 69.2% and 69.8%, respectively. In 200-300 cm soil layer, NS significantly reduced the accumulation amount of NO3--N, but CT had no significant effect on the accumulation amount of NO3--N, and NS, NB, and NSF all had negative effects on NO3--N accumulation. Soil water movement had significant effect on the distribution of NO3--N in soil profile. Soil NO3--N was mainly distributed in 0-40 cm soil layer for NB, NF and NSF treatments, in 0-100 cm and 200-300 cm soil layers for NS treatment, and over the entire profile for NT and CT, and NS, NT and CT treatments had two NO3--N accumulation peaks in soil profile. Different agricultural cultivation measures could reduce soil NO3--N leaching by regulating soil water content, and subsequently improve nitrogen utilization efficiency. Among those measures, NSF could effectively control soil water movement to reduce the NO3--N leaching and accumulation, and thus is a feasible measure to improve soil water and fertility conditions and increase dryland maize yields.

Self-emulsifying peptide drug delivery systems: How to make them highly mucus permeating.

AIM: It was the aim of this study to evaluate the mucus permeating properties of self-emulsifying drug delivery systems (SEDDS) exhibiting different size and zeta potential. METHODS: Various SEDDS were prepared and characterized regarding droplet size, zeta potential and stability. Desmopressin was incorporated as model peptide drug and log P (SEDDS/water) was determined. Thereafter, mucus permeation studies with freshly isolated porcine mucus via Transwell method were performed. Moreover, the impact of water movement on mucus permeation of SEDDS was investigated. Different types of nanocarriers including nanoparticles and liposomes served as references. RESULTS: SEDDS exhibited an initial droplet size of 25.0 ±â€¯2.2, 49.5 ±â€¯4.6, 123.5 ±â€¯12.1, 226.2 ±â€¯93.4 and 502.9 ±â€¯93.7 nm and a zeta potential of +24.4 ±â€¯4.6, +10.6 ±â€¯2.0, 0.2 ±â€¯3.8, -8.2 ±â€¯3.4 and -35.1 ±â€¯2.7 mV. Log P was in the range of 1.29-2.09 and mucus permeation studies with these SEDDS revealed a clear correlation between droplet size and permeation rate. The smaller SEDDS were, the higher their mucus permeating properties were. Negatively charged SEDDS demonstrated a higher permeation rate than positively charged SEDDS. In comparison to liposomes and solid nanocarriers SEDDS exhibited up to 5-fold higher mucus permeating properties. CONCLUSION: Small droplet size and negative zeta potential of SEDDS could be identified as key parameters for their mucus permeating properties.

What you can see by developing real-time radioisotope imaging system for plants: from water to element and CO2 gas imaging.

Since plants live on inorganic elements, absorbing ions from roots and transferring them to each tissue in a plant is an essential activity. However, little is known about the movement of the elements or water in plant tissue. Though fluorescent imaging is now overwhelmingly used at the microscopic level in biology, especially to visualize chemicals or organelles in a cell, radioisotope imaging has become one of the important methods for human imaging in the medical field. In the case of plant studies, however, real-time radioisotope imaging is little-known among plant researchers. The author has developed radioisotope imaging systems using various radioisotopes to study living plant activity, both for elements and for water. Here we review the real-time radioisotope imaging methods we developed, and show new aspects of plant physiology discovered by live imaging.

The landscape model: A model for exploring trade-offs between agricultural production and the environment.

We describe a model framework that simulates spatial and temporal interactions in agricultural landscapes and that can be used to explore trade-offs between production and environment so helping to determine solutions to the problems of sustainable food production. Here we focus on models of agricultural production, water movement and nutrient flow in a landscape. We validate these models against data from two long-term experiments, (the first a continuous wheat experiment and the other a permanent grass-land experiment) and an experiment where water and nutrient flow are measured from isolated catchments. The model simulated wheat yield (RMSE 20.3-28.6%), grain N (RMSE 21.3-42.5%) and P (RMSE 20.2-29% excluding the nil N plots), and total soil organic carbon particularly well (RMSE3.1-13.8%), the simulations of water flow were also reasonable (RMSE 180.36 and 226.02%). We illustrate the use of our model framework to explore trade-offs between production and nutrient losses.

Determination of groundwater recharge mechanism in the deep loessial unsaturated zone by environmental tracers.

Studying the groundwater recharge mechanism in regions with thick unsaturated zone can greatly improve our understanding of hydrological processes since these regions have complex groundwater processes. This study attempted to discuss the groundwater recharge in a region covered by loess over 130m deep in China's Loess Plateau. The water stable isotope, tritium and chloride in precipitation, groundwater and soil water were determined and used as inputs of mass balance methods. The tracer technique is found to be applicable and effective this region with thick unsaturated zone. The groundwater originates from rapid precipitation infiltration through some fast flow paths. The total recharge is likely to be 107±55mmyr-1 accounting for 19±10% of average annual precipitation, while the recharge from preferential flow accounts for 87±4% of the total recharge. The identified recharge mechanism has important implication to groundwater management and recharge modeling for regions covered by thick loess.