Comparative effects of pimecrolimus cream vehicle and three commercially available moisturizers on skin hydration and transepidermal water loss

Background: Hydration and integrity of the horny layer is essential to normal skin function. Objective: Comparison of the hydrating properties of three moisturizers with pimecrolimus cream vehicle. Methods: Four test preparations (high-quality skin cream, cold cream emulsion, emollient oil, pimecrolimus cream vehicle) were applied to four different regions of the forearms and legs. Transepidermal water loss (TEWL) was assessed by evaporimetry at baseline, and 3 and 6 hours after arm application, and electrical capacitance was assessed by corneometry at baseline, and 1, 2, 3 and 6 hours after leg application. Results: Corneometry assessment - in terms of efficacy in moisturizing the skin, test preparations were ranked (best to worst): high-quality skin cream (45.9 arbitrary units versus 75.3; p < 0.001) > pimecrolimus vehicle cream (46.6 versus 61.5; p < 0.001) > emollient oil (43.5 versus 54.8; p = 0.006) > cold cream emulsion (44.8 versus 49.9; p = 0.738). Untreated skin (control) had a mean capacitance of 44.8 units at baseline and 48.5 units at endpoint. Evaporimetry (assessment of TEWL) revealed no significant differences between control and any test preparation at any timepoint. Conclusions: Pimecrolimus cream vehicle has skin hydration properties comparable with highly effective commercially available products. No test preparation had a significant effect on TEWL.

Transepidermal water loss and resting energy expenditure in preterm infants.

Skin water loss of preterm infants, nursed naked in incubators under thermoneutral conditions, was assessed by a method based on the measurement of water vapor pressure gradient close to the skin surface. The corresponding skin evaporative heat loss was calculated using an energy equivalent of 0.58 kcal/g water vaporised. During the first 5 weeks of life, 128 sets of measurements were made on 56 infants whose gestational age ranged from 28 to 37 weeks. In the first week of life, infants of less than 30 weeks of gestation had substantially higher transepidermal water loss (TEWL) and skin evaporative heat loss (skin EHL) (41.5 +/- 11.5 g/kg X day TEWL; 24.1 +/- 6.5 kcal/kg X day skin EHL) than infants of 34 weeks and greater (11.1 +/- 4.1 g/kg X day; 6.4 +/- 2.4 kcal/kg X day). Infants of 30-33 weeks of gestation had intermediate values (22.4 +/- 7.6 g/kg X day; 13 +/- 4.4 kcal/kg X day). From the third week of life on, TEWL was similar for all preterm infants, i.e. 14.2 +/- 2.6 to 12.7 +/- 1.9 g/kg X day and corresponds to skin EHL of 8.2 +/- 1.5 to 7.4 +/- 1.1 kcal/kg X day. There was a significant inverse relationship between gestational age and TEWL and also between postnatal age and TEWL. In an additional group of 7 preterm infants (30-34 weeks of gestation, mean postnatal age of 21 +/- 9 days) transepidermal water loss and energy expenditure were measured simultaneously. The skin evaporative heat loss (8.8 +/- 2.5 kcal/kg X day) accounted for 17 +/- 5% of energy expenditure (53.3 +/- 4.1 kcal/kg X day). This study emphasizes that in infants of less than 30 weeks of gestation, the transepidermal water loss is of great importance and makes a major contribution to water and heat balances.

Exogenous abscisic acid inhibits the water-loss of postharvest romaine lettuce during storage by inducing stomatal closure

Abstract Postharvest lettuce often lose water, thus affecting both its market value and consumer acceptance. However, the mechanism of the water-loss is still waiting well exploration. The aim of the present study was to investigate the effect of a foliar application of ABA on the fresh weight-loss and the chlorophyll content of postharvest lettuce as well as its association with the regulation of stomata. The present data demonstrated that exogenously application of ABA, in a concentration range of 0 to 100 µM, significantly lowered the fresh weight-loss of postharvest lettuce. ABA also delayed chlorophyll reduction during ambient storage, but this protective effect was ABA concentration-dependent. Among the tested ABA concentrations, 50 µM or lower ABA produced an inhibition effect on chlorophyll degradation in postharvest lettuce leaves. The results demonstrated that the exogenous ABA treatment can obviously reduce the transpiration rate of lettuce leaves by promoting the stomatal closure of postharvest lettuce, therefore eventually delay fresh weight-loss. The present study primarily showed that the application of exogenous ABA, which originated from a naturally-produced phytohormone, has a great potential in retaining the freshness of postharvest lettuce that is stored in an ambient condition, although possible practical application still need to be further evaluated.

Buried Treasure: The Economics of Leak Detection and Water Loss Prevention in Ontario

On average approximately 13% of the water that is withdrawn by Canadian municipal water suppliers is lost before it reaches final users. This is an important topic for several reasons: water losses cost money, losses force water agencies to draw more water from lakes and streams thereby putting more stress on aquatic ecosystems, leaks reduce system reliability, leaks may contribute to future pipe failures, and leaks may allow contaminants to enter water systems thereby reducing water quality and threatening the health of water users. Some benefits of leak detection fall outside water agencies’ accounting purview (e.g. reduced health risks to households connected to public water supply systems) and, as a result, may not be considered adequately in water agency decision-making. Because of the regulatory environment in which Canadian water agencies operate, some of these benefits-especially those external to the agency or those that may accrue to the agency in future time periods- may not be fully counted when agencies decide on leak detection efforts. Our analysis suggests potential reforms to promote increased efforts for leak detection: adoption of a Canada-wide goal of universal water metering; development of full-cost accounting and, pricing for water supplies; and co-operation amongst the provinces to promulgate standards for leak detection efforts and provide incentives to promote improved efficiency and rational investment decision-making.

Cutaneous Resistance to Evaporative Water Loss in Brazilian Rhinella (Anura: Bufonidae) from Contrasting Environments

Influenced by taxonomic position. For example, bufonids are regarded as exhibiting a permeable skin that seems typical for terrestrial anurans. However, this assumption is supported by information on only four bufonid species; therefore, the enormous ecological diversity of the family remains poorly Investigated. To assess whether variation in R(s) within related bufonids correlates with environmental aridity, we measured area-specific rates of EWL of two Brazilian populations of Rhinella granulosa (previously Bufo granulosus), one from the Atlantic Forest and other from the semi-arid Caatinga, and compared both with the forest species R. ornato. Rhinella granulosa from the Atlantic Forest had higher cutaneous resistance than conspecifics from Caatinga and R. ornata. Rhinella ornato presented the lowest cutaneous resistance values. However, Rs were very close to zero In all three populations. We conclude that enhanced Rs is not part of the suite of traits allowing R. granulosa to exploit the Caatinga, and that variation in R(s) within bufonids may relate to traits other than water conservation. Some Information on microhabitat occupation and ventral skin morphology supports the idea that exceptional abilities for detecting and taking up water may be the key factors enhancing the survival of R. granulosa, and possibly other bufonids, in xeric environments.

Effect of temperature on incubation period, embryonic mortality, hatch rate, egg water loss and partridge chick weight (Rhynchotus rufescens)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaporative water loss and oxygen uptake in two casque-headed tree frogs, Aparasphenodon brunoi and Corythomantis greeningi (Anura, Hylidae)

Evaporative water loss (EWL) and oxygen uptake ((V) over dot o(2)) was measured in two species of tree frogs with cranial co-ossification, Aparasphenodon brunoi and Corythomantis greeningi. Both species use their head to seal the entrance of bromeliads, tree holes or rocky crevices used as shelters. EWL was significantly reduced in sheltered individuals of both species as compared with those exposed nude to desiccation. EWL per unit area through the head surface was significantly lower than the body skin for A. brunoi but not for C., greeningi. EWL per unit surface area through C. greeningi body skin was about 50% that of A. brunoi, indicating a less permeable skin in the former species. The relationship between cranial coossification and EWL is discussed. ((V) over dot o(2)) in A. brunoi was comparable with other anurans of similar size, whereas in C. greeningi, it was lower than predicted from body mass. Moreover, ((V) over dot o(2)), in C. greeningi showed less sensitivity to temperature increase than in A. brunoi. C. greeningi occurs in a drier environment than A. brunoi, and this appears to be reflected in their EWL and ((V) over dot o(2)) characteristics. (C) 1997 Elsevier B.V.

The amount of water loss was determined by drying at 110°C

Deep-sea deposits, which resemble in nearly every respect the deep-sea oozes have been observed in many islands of the East-Indian Archipelago, notably the islands of Borneo, Rotti and Timor. Manganese nodules are found in equivalents of deeep-sea red clays on Timor and Rotti island. In this paper, those relative to red clay deposits dating from a Cretaceous ocean are analysed in detail in the vicinity of the town of Niki Niki in Western Timor.

Tab. 1: Mean water loss by mosses and lichens at 40%

The loss of water in a desiccating atmosphere (c.40% r.h. at 10°C) and uptake of water from a saturated atmosphere (100% r.h. at 10°C) was recorded at intervals over periods of many hours or days in the dominant mosses and macroiichens occurring near the Australian Casey Station. Wilkes Land, continental Antarctica. While major differences exist in the water holding capacity and rates of water loss between mosses and lichens, the minimum levels attained after prolonged exposure to desiccating conditions are remarkably similar. By contrast, the volume of water absorbed from a saturated atmosphere is very similar in both groups of cryptogams. Morphological and anatomical characters are responsible for many of the differences, both between species, and within species exhibiting different growth features. Thus, significantly larger amounts of water are held by colonies of Bryum algens with a dense tomentum of rhizoids than those with sparse rhizoids; similarly, the rhizinate Umbilicaria aprina held a greater volume of water than the erhizinate U. decussata. The filamentous mat form of Alectoria mimiscula permits a much higher water content to be attained than in the coarser fruticose forms of Usnea sphacelata and U. antarctica. The dense shoot arrangement in Schistidium antarcticum accounts for the high water holding capacity in the hydric turf form whereas the less densely packed shoots and thicker cell walls of the xeric cushion form maintain a lower water content. The rate of water loss (as percentage dry weight) was much faster in the turf form of Schistidium and tomenlose form of Bryum, although this trend was reversed when expressed as percentage of the initial water content. Minimal water contents arc achieved by the lichens in desiccating conditions within 6-12 hours, whereas the mosses take several times longer. The water relations characteristics of these cryptogams are considered in the light of their distribution in the field and of their metabolic activity under prevailing Antarctic conditions.

Effects of Xylem pH on Transpiration from Wild-Type and flacca Tomato Leaves1 : A Vital Role for Abscisic Acid in Preventing Excessive Water Loss Even from Well-Watered Plants

The pH of xylem sap from tomato (Lycopersicon esculentum) plants increased from pH 5.0 to 8.0 as the soil dried. Detached wild-type but not flacca leaves exhibited reduced transpiration rates when the artificial xylem sap (AS) pH was increased. When a well-watered concentration of abscisic acid (0.03 μm) was provided in the AS, the wild-type transpirational response to pH was restored to flacca leaves. Transpiration from flacca but not from wild-type leaves actually increased in some cases when the pH of the AS was increased from 6.75 to 7.75, demonstrating an absolute requirement for abscisic acid in preventing stomatal opening and excessive water loss from plants growing in many different environments.

Water-loss investigations: Lake Hefner 1958 evaporation reduction investigations.

Mode of access: Internet.

Water loss management strategies for developing countries

Diese Arbeit beschäftigt sich mit nicht in Rechnung stellbaren Wasserverlusten in städtischen Versorgungsnetzen in Entwicklungsländern. Es soll das Wissen über diese Verluste erweitert und aufgezeigt werden, ob diese auf ein ökonomisch vertretbares Maß reduziert werden können. Die vorliegende Doktorarbeit untersucht solche unberechneten Wasserverluste und versucht, neben der Quantifizierung von Leckagen auch Entscheidungswerkzeuge für ein verbessertes Management der Versorgungsnetze in Entwicklungsländern zu erarbeiten. Als Fallstudie dient Harare, die Hauptstadt von Simbabwe. Wasserverluste in Verteilungsnetzen sind unvermeidbar, sollten aber auf ein ökonomisch tragbares Niveau reduziert werden, wenn ein nachhaltiger Betrieb erreicht werden soll. Wasserverluste können sowohl durch illegale und ungenehmigte Anschlüsse oder durch Undichtigkeiten im Verteilnetz, als auch durch mangelhafte Mess- und Berechnungssysteme entstehen. Es sind bereits viele Ansätze zur Verringerung von Verlusten in Wasserverteilsystemen bekannt geworden, entsprechend existieren dazu auch zahlreiche Methoden und Werkzeuge. Diese reichen von computergestützten Verfahren über gesetzliche und politische Vorgaben sowie ökonomische Berechnungen bis hin zu Maßnahmen der Modernisierung der Infrastruktur. Der Erfolg dieser Anstrengungen ist abhängig von der Umsetzbarkeit und dem Umfeld, in dem diese Maßnahmen durchgeführt werden. Die Bewertung der Arbeitsgüte einer jeden Wasserversorgungseinheit basiert auf der Effektivität des jeweiligen Verteilungssystems. Leistungs- und Bewertungszahlen sind die meist genutzten Ansätze, um Wasserverteilsysteme und ihre Effizienz einzustufen. Weltweit haben sich zur Bewertung als Indikatoren die finanzielle und die technische Leistungsfähigkeit durchgesetzt. Die eigene Untersuchung zeigt, dass diese Indikatoren in vielen Wasserversorgungssystemen der Entwicklungsländer nicht zur Einführung von Verlust reduzierenden Managementstrategien geführt haben. Viele durchgeführte Studien über die Einführung von Maßnahmen zur Verlustreduzierung beachten nur das gesamte nicht in Rechnung stellbare Wasser, ohne aber den Anteil der Leckagen an der Gesamthöhe zu bestimmen. Damit ist keine Aussage über die tatsächliche Zuordnung der Verluste möglich. Aus diesem Grund ist ein Bewertungsinstrument notwendig, mit dem die Verluste den verschiedenen Ursachen zugeordnet werden können. Ein solches Rechenwerkzeug ist das South African Night Flow Analysis Model (SANFLOW) der südafrikanischen Wasser-Forschungskommission, das Untersuchungen von Wasserdurchfluss und Anlagendruck in einzelnen Verteilbezirken ermöglicht. In der vorliegenden Arbeit konnte nachgewiesen werden, dass das SANFLOW-Modell gut zur Bestimmung des Leckageanteiles verwendet werden kann. Daraus kann gefolgert werden, dass dieses Modell ein geeignetes und gut anpassbares Analysewerkzeug für Entwicklungsländer ist. Solche computergestützte Berechnungsansätze können zur Bestimmung von Leckagen in Wasserverteilungsnetzen eingesetzt werden. Eine weitere Möglichkeit ist der Einsatz von Künstlichen Neuronalen Netzen (Artificial Neural Network – ANN), die trainiert und dann zur Vorhersage der dynamischen Verhältnisse in Wasserversorgungssystemen genutzt werden können. Diese Werte können mit der Wassernachfrage eines definierten Bezirks verglichen werden. Zur Untersuchung wurde ein Mehrschichtiges Künstliches Neuronales Netz mit Fehlerrückführung zur Modellierung des Wasserflusses in einem überwachten Abschnitt eingesetzt. Zur Bestimmung des Wasserbedarfes wurde ein MATLAB Algorithmus entwickelt. Aus der Differenz der aktuellen und des simulierten Wassernachfrage konnte die Leckagerate des Wasserversorgungssystems ermittelt werden. Es konnte gezeigt werden, dass mit dem angelernten Neuronalen Netzwerk eine Vorhersage des Wasserflusses mit einer Genauigkeit von 99% möglich ist. Daraus lässt sich die Eignung von ANNs als flexibler und wirkungsvoller Ansatz zur Leckagedetektion in der Wasserversorgung ableiten. Die Untersuchung zeigte weiterhin, dass im Versorgungsnetz von Harare 36 % des eingespeisten Wassers verloren geht. Davon wiederum sind 33 % auf Leckagen zurückzuführen. Umgerechnet bedeutet dies einen finanziellen Verlust von monatlich 1 Millionen Dollar, was 20 % der Gesamteinnahmen der Stadt entspricht. Der Stadtverwaltung von Harare wird daher empfohlen, aktiv an der Beseitigung der Leckagen zu arbeiten, da diese hohen Verluste den Versorgungsbetrieb negativ beeinflussen. Abschließend wird in der Arbeit ein integriertes Leckage-Managementsystem vorgeschlagen, das den Wasserversorgern eine Entscheidungshilfe bei zu ergreifenden Maßnahmen zur Instandhaltung des Verteilnetzes geben soll.

Effectively positioning water loss event in smart water networks

With the eye-catching advances in sensing technologies, smart water networks have been attracting immense research interest in recent years. One of the most overarching tasks in smart water network management is the reduction of water loss (such as leaks and bursts in a pipe network). In this paper, we propose an efficient scheme to position water loss event based on water network topology. The state-of-the-art approach to this problem, however, utilizes the limited topology information of the water network, that is, only one single shortest path between two sensor locations. Consequently, the accuracy of positioning water loss events is still less desirable. To resolve this problem, our scheme consists of two key ingredients: First, we design a novel graph topology-based measure, which can recursively quantify the "average distances" for all pairs of senor locations simultaneously in a water network. This measure will substantially improve the accuracy of our positioning strategy, by capturing the entire water network topology information between every two sensor locations, yet without any sacrifice of computational efficiency. Then, we devise an efficient search algorithm that combines the "average distances" with the difference in the arrival times of the pressure variations detected at sensor locations. The viable experimental evaluations on real-world test bed (WaterWiSe@SG) demonstrate that our proposed positioning scheme can identify water loss event more accurately than the best-known competitor.

Environmental Controls In The Water Use Patterns Of A Tropical Cloud Forest Tree Species, Drimys Brasiliensis (winteraceae).

Trees from tropical montane cloud forest (TMCF) display very dynamic patterns of water use. They are capable of downwards water transport towards the soil during leaf-wetting events, likely a consequence of foliar water uptake (FWU), as well as high rates of night-time transpiration (Enight) during drier nights. These two processes might represent important sources of water losses and gains to the plant, but little is known about the environmental factors controlling these water fluxes. We evaluated how contrasting atmospheric and soil water conditions control diurnal, nocturnal and seasonal dynamics of sap flow in Drimys brasiliensis (Miers), a common Neotropical cloud forest species. We monitored the seasonal variation of soil water content, micrometeorological conditions and sap flow of D. brasiliensis trees in the field during wet and dry seasons. We also conducted a greenhouse experiment exposing D. brasiliensis saplings under contrasting soil water conditions to deuterium-labelled fog water. We found that during the night D. brasiliensis possesses heightened stomatal sensitivity to soil drought and vapour pressure deficit, which reduces night-time water loss. Leaf-wetting events had a strong suppressive effect on tree transpiration (E). Foliar water uptake increased in magnitude with drier soil and during longer leaf-wetting events. The difference between diurnal and nocturnal stomatal behaviour in D. brasiliensis could be attributed to an optimization of carbon gain when leaves are dry, as well as minimization of nocturnal water loss. The leaf-wetting events on the other hand seem important to D. brasiliensis water balance, especially during soil droughts, both by suppressing tree transpiration (E) and as a small additional water supply through FWU. Our results suggest that decreases in leaf-wetting events in TMCF might increase D. brasiliensis water loss and decrease its water gains, which could compromise its ecophysiological performance and survival during dry periods.