Excessive Water Loss Research Articles

Better placement of soil moisture point measurements guided by 2D resistivity tomography for improved irrigation scheduling

Soil moisture beneath irrigated crops has traditionally been determined using point measurement methods such as neutron probes or capacitance systems. These approaches cannot measure soil moisture at depths beyond the root-zone of plants and have limited lateral coverage. It is shown that surface two-dimensional electrical resistivity tomography (ERT) can be used to map the spatial heterogeneity in soil moisture throughout a field under irrigated cotton. The case study demonstrates that ERT provides a better understanding of the pathways of water migration, and provides spatial information on how water storage changes throughout the growing season. We conclude that ERT should be integrated into farm water management surveys to delineate zones of excessive water loss due to deep drainage and to improve the positioning of point measurement methods for measuring soil moisture, thereby improving irrigation scheduling.

Equisetum species show uniform epicuticular wax structures but diverse composition patterns

Only few data on the epicuticular waxes (EWs) of horsetails are available. This contribution therefore focuses on the wax micromorphology and chemical composition of Equisetum species of the subgenera Equisetum and Hippochaete. Distribution patterns and structural details of EW on the shoots were studied by scanning electron microscopy. After extraction with chloroform, the chemical composition of wax isolates was analysed by gas chromatography. Epicuticular wax crystals were non-oriented platelets or membraneous platelets. They were usually located on subsidiary cells of stomata and adjacent cells. Other parts of the shoots were covered mainly with a smooth wax film or small granules only. The chemical constituents found were alkanes, esters, aldehydes, primary alcohols and free fatty acids in a range of C(20)-C(36) (in esters C(36)-C(56)). All species of the subgenus Hippochaete showed a similar pattern of fractions with high percentages of alkanes and aldehydes, whereas the subgenus Equisetum species had distinctly different wax compositions. Extracts from the internodes-surfaces without well-developed EW crystals and only few stomata-showed the lowest contents of aldehydes. The covering with EW crystals will provide unhindered gas exchange and, combined with intracuticular wax, may prevent excess water loss during winter in the evergreen shoots of the subgenus Hippochaete. The results indicate that the Equisetum wax micromorphology and biosynthesis are comparable to EW of other pteridophyte classes and mosses.

Treatment of Variable Water Sources: Adaptations for a Flexible Desalination System

There are a number of locations where a utility would want to be able to treat multiple sources of water with one treatment system. Those that the Bureau of Reclamation (Reclamation) has come across recently are:The Texas Gulf Coast where brackish surface or groundwater is available for much of the year but only seawater is available during dry seasons;South central California where the character of the irrigation drainage water changes with the intensity of irrigation;Inland desert areas where the composition of brackish surface and groundwater is significantly different when augmented with storm water. Reclamation assisted the US Office of Naval Research in development and demonstration of the Expeditionary Unit Water Purifier system which can produce 378 m3/day (100,000 gal/day) of potable water from any liquid source water up to 60 g/L TDS under 35°C. The system was tested under the Environmental Technology Validation (ETV) program overseen by NSF International for the US Environmental Protection Agency (EPA). Test water sources were seawater, turbid surface water, and tertiary wastewater. As a complete system, it performed well with each source. It was only capable of 50% recovery of water however. Because of this, the system has been turned down for potential emergency applications due to the excessive loss of water. This issue occurring at the same time as the three situations mentioned above prompted a proposal to design a flexible system that could be adapted to achieve high water recovery when the feed source allows while still maintaining the capability of recovering energy when the remaining concentrate pressure allows.

Relationship between jasmonic acid accumulation and senescence in drought-stress.

Plants raised from shoot-tip cultures of apricot (DT: drought-tolerant genotypePrunus armeniaca L. cv. Ansu Maxim, and DS: drought-sensitive genotype P. armeniaca L. cv. Longwangmao) were grown in pots of peat-based compost. Water was withheld for 12 days. Gas chromatography–mass spectrometry analysis indicated that jasmonic acid (JA) levels in leaves of DT plants increased three-fold on day 12 after water was withheld, while there was little variation in leaf JA in DS plants for the whole drying period. There was no significant difference in the JA concentration in roots of the two apricot cultivars from 1 – 9 days. JA concentration in DT plants roots increased slightly by 12 days compared to JA concentration in DS. There was 100% abscission in DT plants at 13 days, earlier than 14 days for DS. Two months after rewatering, 12 of the 18 DT plants were alive, but all 18 DS plants were dead. Exogenous JA accelerated leaf senescence in both DT and DS plants by chlorophyll loss. After JA treatment there were increased malondialdehyde (MDA) levels in DT and DS plants. These results suggest that the transient JA accumulation from DT leaves may promote leaf senescence due to soil drying, thus avoiding excessive water loss, and aiding drought survival. Key words: Apricot, drought stress, leaf, jasmonic acid, senescence.

Interleukin-28 and interleukin-29: novel regulators of skin biology.

The skin forms an essential barrier between the inside of an organism and the environment. In addition to its function in insulation, temperature regulation, and sensation, it protects the body against physical trauma, pathogens, UV radiation, and excessive water loss. Many processes necessary for maintaining the skin integrity, including antimicrobial/antiviral defense, wound healing, and removal of tumors, are regulated by cytokines. Accumulating results lead us to assume that interleukin (IL)-28 and IL-29, 2 novel members of the IL-10-interferon cytokine family, are important regulators of some of these processes. In the skin, IL-28 and IL-29 can be produced by virus-infected cells, maturing dendritic cells (DCs), and regulatory T-cells, and they mainly influence keratinocytes and melanocytes. In keratinocytes, IL-28 and IL-29 induce growth inhibition. Simultaneously, these cytokines increase the cellular synthesis of proteins that directly hinder virus replication and enhance the readiness to present viral antigens to immune cells. Further, IL-28 and IL-29 upregulate expression of viral and microbial sensing cellular receptors, including toll-like receptor (TLR)3, TLR2, and melanoma differentiation associated gene 5, and strengthen the cellular response to these receptors' ligands. Thereby, in the noninfected skin IL-28 and IL-29 enhance the capacity of keratinocytes to react to viral and microbial products and at least indirectly upregulate their inflammatory potential and innate immunity. IL-28 and IL-29 can act synergistically with other mediators secreted during DC maturation (eg, IL-20). In summary, IL-28/IL-29 may play an important role in the skin in the clearance of viral and microbial infections and in the removal of tumors.

Quality Attributes Limiting Snap Bean (Phaseolus vulgaris L.) Postharvest Life at Chilling and Non-chilling Temperatures

‘Opus’ and ‘Leon’ snap beans were harvested, hydrocooled, held for 2 to 7 days at five temperatures and evaluated for quality attributes. The objectives of this work were to obtain quality curves at chilling and non-chilling temperatures, identify for each temperature which quality attributes limit snap beans marketability, and determine the remaining compositional value at the point the snap beans had reached the minimum acceptable quality for sale. Results from this study showed that temperature had a significant effect on the shelf life and overall quality of snap bean. Snap beans stored at temperatures higher than 10 °C were less green, softer and more shriveled, had higher weight loss, and lower acidity, soluble solids, ascorbic acid, and chlorophylls contents than those stored at lower temperatures. When stored at 1, 5, and 10 °C, ‘Leon’ snap beans developed chilling injury (CI), whereas no visual symptoms were noticeable in ‘Opus’ snap beans. Although CI might have indirectly affected the quality of ‘Leon’ snap beans, it was not considered a sensory quality-limiting factor. Overall, weight loss was the first non-sensory quality attribute to reach the limit of acceptability, whereas firmness was the first sensory quality attribute, followed by color, to reach the limit of acceptability and therefore limited the shelf life of ‘Opus’ and ‘Leon’ snap beans cultivars. As a result of excessive water loss and accelerated softening, shelf life of both snap bean cultivars was relatively short, ranging from 1 to 3.5 days, depending on the temperature and cultivar. Furthermore, the compositional value was considerably reduced at the point of poor sensory quality. The high weight loss obtained for beans stored at all temperatures suggests that the use of a film wrap may help create a high relative humidity and therefore reduce water loss, maintain better overall quality, and extend the shelf life of snap beans. Overall, maximum shelf life and best quality were obtained when ‘Opus’ and ‘Leon’ snap beans were stored at 10 °C.

PHOTOSYNTHETIC CHARACTERISTICS AND PRODUCTIVITY OF THE COCONUT PALM

Among the tree crops in the tropics the coconut palm occupies an importantposition as a food, oil, and fibre crop. Productivity of crop species depends on thecombined effect of their genetic constitution, climate, nutrition and other bioticfactors. To increase the productivity of the coconut palm it is necessary to have abasic understanding of physiological processes such as assimilation of carbon andgrowth in relation to climatic factors.In-situ photosynthetic measurement of coconut seedlings using Li-COR 6500portable photosynthesis system revealed that their maximum photosynthetic capacityis attained at photosynthetic photon flux densities (PPFD) ranging from 1400-1700u moles photons m'2 S"1. The rate of apparent photosynthesis (A) of the coconutpalm varies between 2-15 a moi C02 m"2 S"1 depending on leaf age, nutritional status.and climatic factors. The rate of leaf respiration was closely similar in young andolder leaves ranging from - 2 to -1 fi mol C02m'2S"'. The measured light-useefficiency of the coconut palm was found to be 1.2 g MJ"1 and the conversionefficiency of solar energy was approximately 2.4%.Water deficit is the major constraint causing wide fluctuations in photosynthesis.Due to height of trees, the leaves in the canopy are exposed to a high wind velocityas well as water and thermal stresses. As a result, under soil water deficit conditionscoconut palms reduce excessive water loss and gaseous exchange by mid-day closureof stomata and maintain stomatal conductance at a lower level. However, the rateof apparent photosynthesis and the ratio of intercellular to ambient partial pressureof C 0 2 (P/PJ are not decreased proportionately with the stomatal conductance.

Research progression in inducing factors of evaporative dry eye

干眼主要分为水样液缺乏型干眼和蒸发过强型干眼.蒸发过强型干眼是在泪液分泌功能正常的情况下,由各种因素导致暴露的眼球表面泪液过量损失引起的.诱发此类干眼的因素包括泪膜脂质层异常、瞬目频率降低、配戴角膜接触镜、眼表障碍及眼表疾病、环境因素等.随着信息社会的发展,人们生活和工作方式的改变,蒸发过强型干眼的发病率逐渐增高,发病年龄年轻化,而临床上蒸发过强型干眼容易被忽视或误诊,就其主要诱发因素及其诊断和治疗的研究进展进行综述。

Added salt helps sunbirds and honeyeaters maintain energy balance on extremely dilute nectar diets

Nectar-feeding birds ingest excess water and risk loss of solutes when they excrete it. Previous work has shown that white-bellied sunbirds (Cinnyris talatala) are unable to maintain energy balance on extremely dilute sucrose diets without salts (e.g. <0.25 mol l(-1)), and that they lose more electrolytes (i.e. Na(+) and K(+)) via cloacal fluid on these diets than on more concentrated diets. Using white-bellied sunbirds and New Holland honeyeaters (Phylidonyris novaehollandiae) we tested the effect of adding electrolytes to a 0.1 mol l(-1) sucrose diet, by including equimolar NaCl and KCl at concentrations from 5 to 40 mmol l(-1) and the individual salts at 20 mmol l(-1). Addition of salts enabled both species to drink significantly more of the 0.1 mol l(-1) sucrose diet than in the absence of salts, and mass loss during the experiment was reduced when salt was included. The larger honeyeaters may be more susceptible to electrolyte depletion than the smaller sunbirds. On 20 mmol l(-1) combined salts, both sunbirds and honeyeaters consumed eight times their body mass in fluid daily. KCl alone had no effect. Birds are thus limited in their consumption of extremely dilute diets by increasing losses of Na(+). This was confirmed by measuring plasma Na(+) levels, which decreased in both species in the absence of dietary Na(+). In addition, sucrose assimilation efficiencies were slightly, but significantly lower when sunbirds were fed salt-free diet, while glucose levels in ureteral urine remained extremely low. It is concluded that Na(+) depletion on very dilute salt-free diets does not affect Na(+)-glucose transport activity in the kidney, but interferes with sugar digestion and/or assimilation in the intestine.

The cystatin M/E‐cathepsin L balance is essential for tissue homeostasis in epidermis, hair follicles, and cornea

Cystatin M/E (CST6) is a nonredundant, epithelium-specific protease inhibitor with a presumed role in epidermal differentiation and tumor suppression. We have previously reported that cystatin M/E deficiency in Cst6(-/-) mice causes neonatal lethality because of excessive transepidermal water loss. Biochemical evidence suggests that cystatin M/E controls the activity of legumain, cathepsin L, cathepsin V, and transglutaminase-3. Using a genetic approach we sought to define the role of cystatin M/E in epithelial biology by identification of its target proteases and their downstream functions. Ablation of cathepsin L in a Cst6(-/-) background (Cst6(-/-)Ctsl(-/-) double-knockout mice) restored viability and resulted in normalization of stratum corneum morphology. Ablation of legumain or transglutaminase-3 in Cst6(-/-) mice, however, did not rescue the lethal phenotype. Intriguingly, both Cst6(-/-)Ctsl(-/-) and Cst6(-/-)Ctsl(+/-) mice were viable, but the absence of cystatin M/E caused scarring alopecia in adult animals. In the cornea of Cst6(-/-)Ctsl(+/-) mice, we observed keratitis, hyperplasia, and transition to a cornified epithelium. Evidence is provided that activation of cathepsin D and transglutaminase-1 are downstream events, dependent of cathepsin L activity. We conclude that a tightly regulated balance between cathepsin L and cystatin M/E is essential for tissue integrity in epidermis, hair follicles, and corneal epithelium.

Enhanced tolerance to water stress in adults of the South India strain of the seed beetle, Callosobruchus maculatus (Coleoptera: Bruchidae), as a product of large body size

A water balance study was conducted on newly-emerged adults of seed beetle, Callosobruchus maculatus, to explore how South India strain survives longer than Brazil strain in laboratory cultures. No difference between strains was noted with regard to dehydration tolerance, and water conservation features confirm classification of this species as xerophilic. There was no evidence for critical transition temperature (CTT), thereby safeguarding against excessive water loss as the temperature rises, or for critical equilibrium humidity (CEH), indicating that water is imbibed as a liquid. In contrast to the Brazil strain, adults of the South India strain were distinguished by a larger body size, resulting in a lower net transpiration rate with suppressed activation energy (Ea, permeability constant) for water loss, and a lower percentage body water content due to a higher dry mass (fat). These modifications for water balance of the South India strain link enhancing time for reproduction and distribution spread in the adult with the higher seed consumption/respiratory rate trait that has been previously reported for larvae of this strain.

A physiologically active polysaccharide hydrogel promotes wound healing

When the skin is injured, the subcutaneous tissues and organs are threatened by pathogens and excessive water loss. Wound dressings are, therefore, needed to protect the wound site from infection and improve the wound closure. Natural polysaccharides have been applied for various biomaterials including wound dressings, which show their advantages in biocompatibility, low toxicity, and pharmaceutical biomedical activity. In this study, a natural polysaccharide Bletilla striata polysaccharide (BSP) hydrogel is prepared by an oxidation and crosslinking methods. This BSP hydrogel represents preferable swelling ability and appropriate water vapor transmission rate. Using a full-thickness trauma mouse model, the hydrogel is applied on the in vivo cutaneous wound healing. Compared with the control groups, the BSP hydrogel achieves the much better healing results. The quantification of the infiltrating inflammatory cells and the level of tumor necrosis factor alpha (TNF-alpha) in the BSP group are attenuated, whereas the secretion of the epidermal growth factor (EGF) is highly elevated. On the 11th day after surgery, the wound area in the BSP hydrogel group is only 1/5-1/3 of those in the control groups. This new BSP hydrogel is proved to control the inflammatory responses and accelerate the wound closure and has potential application in wound healing. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.

Serum sodium disorders: safe management

Sodium (Na+) is the main electrolyte in the extracellular compartment (ECC) and its level represents the relative content of sodium in relation to water. Sodium loss in excess of water loss or water gain will result in hyponatraemia, while water loss in excess of sodium or sodium excess will result

Water and heat fluxes above a lowland dipterocarp forest in Peninsular Malaysia

AbstractWe measured the fluxes of sensible and latent heat between a low‐land dipterocarp forest in Peninsular Malaysia and the atmosphere. No clear seasonal or interannual changes in latent heat flux were found from 2003 to 2005, while sensible heat flux sometimes fluctuated depending on the fluctuation of incoming radiation between wet and dry seasons. The evapotranspiration rates averaged for the period between 2003 and 2005 were 2·77 and 3·61 mm day−1 using eddy covariance data without and with an energy balance correction, respectively. Average precipitation was 4·74 mm day−1. Midday surface conductance decreased with an increasing atmospheric water vapour pressure deficit and thus restricted the excess water loss on sunny days in the dry season. However, the relationship between the surface conductance and vapour pressure deficit did not significantly decline with an increase in volumetric soil water content even during a period of extremely low rainfall. Copyright © 2009 John Wiley &amp; Sons, Ltd.

Treasure or artifact: a decade of p63 research speaks for itself

Treasure or artifact: a decade of p63 research speaks for itself

Architectural Engineering of Rice Panicle for Increased Productivity: A Powerful Biological Tool for Combating Agricultural Water Crisis

Grain sterility in rice increases with plant water deficit, particularly during panicle development. We compared certain aspects of water relations of rice panicle with that of flag leaf. The emerging young rice panicles transpired more water than the flag leaves, despite the latter being heavily lashed with stomata. On an individual organ basis, the rate of water loss by panicle was about 4.5 times greater (45 × 10−4 ml min−1 panicle−1) than the rate exhibited by flag leaf (10 × 10−4 ml min−1 leaf −1), whereas on an equal or unit area basis, the magnitude of difference in water loss was 22 times higher (33.5 × 10−6 ml min−1 cm−2) than the rate of water loss by flag leaves (1.3 × 10−6 ml min−1 cm−2). Panicles coated with gypsum, covered by polythene bags, compacted with threads or devoid of awns had a significant impact on the rate of water loss. For cv. NDRH-2, water loss was less when panicle was coated with gypsum than when it was covered with polythene bags or compacted with threads in that order, i.e., gypsum coating > polythene covering > compacting. Further, awns inhibited water loss in cv. Tipakhiya. Open panicles of cv. Sathi transpired more water than those inherently hidden inside the leaf sheaths. Barriers to water loss increased the water content and viability of the panicles during soil-moisture stress. Increased panicle water content decreased the spikelet desiccation injury and spikelet sterility during plant water stress. We concluded that it was the excessive water loss by panicles, not leaves, and the diurnal fluctuations, which appeared to be the first and foremost signal-transduction stimulus, that caused the commonly observed grain sterility and its irregular and random distribution within the panicle.

Hypernatremia

Hypernatremia

Crosstalk of Nitric Oxide with Ca 2+ in Stomatal Movement in Vicia faba Guard Cells

For gaining further insights into Ca 2+ function in nitric oxide (NO)-regulated stomatal movement, Vicia faba guard cell protoplasts were patch-clamped in a whole-cell configuration. In the absence of extracellular Ca 2+, sodium nitroprusside (SNP, the NO donor) inhibited inward rectifying K + current at a concentration of 10 or 100 μmol L −1, but had little effect on outward rectifying K + current. SNP significantly activated outward rectifying K + current when CaCl 2 (0.1 mmol L −1) was added to the bath solution, and LaCl 3 could alleviate this effect of NO. In contrast, 0.1 mmol L −1 CaCl 2 alone had little effect on inward or outward rectifying K + current. Extracellular Ca 2+ significantly inhibited inward rectifying K + current and activated outward rectifying K + current at the concentration of 10 mmol L −1, and this effect was not alleviated by 2-(4-carboxyphenyl)-4,4,5,5 tetramethylimidazoline (c-PTIO). When monitoring Ca 2+ and NO levels in single cells by Fluo 3-AM and 4,5-diaminofluorescein diacetate (DAF-2DA), the specific fluorescence probes for Ca 2+ and NO, respectively, SNP at 100 μmol L −1 evidently induced the accumulation of Ca 2+ in guard cells, and the induction could be partially alleviated by LaCl 3. However, CaCl 2 at 0.1 mmol L −1 or 10 mmol L −1 had small effect on the accumulation of NO in the guard cells. These results indicated that NO promoted influx of Ca 2+ into cytoplasm through Ca 2+ channels to activate outward rectifying K + channels and promotes K + efflux. Alternatively, NO inhibited inward rectifying K + channels and blocks K + influx, thus inhibiting stomatal opening and preventing excessive loss of water in plants. In addition, extracellular Ca 2+ at a concentration of 10 mmol L −1 modulated stomatal movement and plasma membrane K + channels of V. faba guard cells in a NO-independent signaling pathway.

Antibodies raised against tobacco aquaporins of the PIP2 class label viscin tissue of the explosive dwarf mistletoe fruit

Dwarf mistletoes, genus Arceuthobium, are parasitic flowering plants and forest pests. In western North America, Arceuthobium americanum (lodgepole pine dwarf mistletoe) is principally found on Pinus contorta var. latifolia (lodgepole pine). Dwarf mistletoes disperse their seeds by an explosive process that involves the buildup of hydrostatic pressure within a mucilaginous fruit tissue called the 'viscin'. Living viscin tissue envelops the discharged seeds. This study examined the possibility that aquaporins, critical in plant water relations, might be found in the dwarf mistletoe fruit, specifically the viscin cells. An antibody raised against a tobacco plasma membrane intrinsic 2 (PIP2) aquaporin was used with a gold-labeled secondary antibody to probe dwarf mistletoe fruit at various developmental stages. Viscin cell plasma membranes were successfully labeled with the anti-tobacco probe, and the validity of the immunolabeling was supported by Western blot analysis, showing a strong signal at about 30 kDa, which is at the expected size of a PIP2. A definitive immunolabeling pattern, supported by quantification of gold signal per membrane length, was observed: viscin cells sampled early in development had abundant gold label at their plasma membranes (1.93 +/- 0.13 to 2.13 +/- 0.33 gold particles per microm membrane), while other areas of the cells had no discernible label. Viscin cells sampled near the time of explosive discharge had significantly less label at the plasma membrane (0.21 gold particles +/- 0.11 per microm membrane, P < 0.05), and label was seen at vesicular membranes. Aquaporins likely have a role in directing water to the viscin mucilage early in development, but are retrieved via endocytosis to prevent excess water loss from viscin cells when discharge is imminent.

No. 3 Vol. 42, No. 2, pp. 94–101, 2008 Effect of Birch (Betula platyphylla Sukatchev var. japonica Hara) sap on cultured human epidermal keratinocyte differentiation

The beauty of ideal skin texture is closely associated with dermal moisture factors. The key factors of skin moisture are NMF (natural moisturizing factor) and skin normal barrier function. The former keeps dermal surface moisture, and the later protects from excess water loss. So we have searched for the ingredient that improves these factors. Birch sap has been widely used as an effective drink for anti‐fatigue and anti‐stress. However, the effect of birch sap on skin as a cosmetic agent has not been known entirely. In this study, we investigated the effects of birch (Betula platyphylla Sukatchev var. japonica Hara) sap on human skin. Birch sap induced epidermal keratinocyte differentiation properties in vitro. We assessed two epidermal differentiation agents. Filaggrin is a precursor protein of NMF, and involucrin is one of the precursor proteins of the cornified cell envelope (CE), which is related to normal barrier function. We have evaluated the production of these proteins where birch sap was applied to human normal keratinocytes. Birch sap not only increased mRNA expression of filaggrin and involucrin, but also accelerated these proteins production. Otherwise, birch sap did not have any influence for IL‐6 production, which is related to inflammatory and aberrant keratinocyte proliferation. The results of induced differentiation properties on birch sap‐treated keratinocytes are very similar to the differentiation induced by calcium in vitro. This similarity suggested that birch sap has a differentiation inducible property on in vitro cultured keratinocytes. Our study suggested that birch sap is able to control both moisturizing‐ and barrier‐related factor production. From these effects, birch sap provides appropriate epidermal functions and skin homeostasis, and revealed itself as a very useful ingredient in the cosmetic field.