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Water as a Physiological Currency: Hydration State Impacts Immune Function, Metabolic Substrates, and Reproductive InvestmentJanuary 2019 (has links)
abstract: Environmental changes are occurring at an unprecedented rate, and these changes will undoubtedly lead to alterations in resource availability for many organisms. To effectively predict the implications of such changes, it is critical to better understand how organisms have adapted to coping with seasonally limited resources. The vast majority of previous work has focused on energy balance as the driver of changes in organismal physiology. While energy is clearly a vital currency, other resources can also be limited and impact physiological functions. Water is essential for life as it is the main constituent of cells, tissues, and organs. Yet, water has received little consideration for its role as a currency that impacts physiological functions. Given the importance of water to most major physiological systems, I investigated how water limitations interact with immune function, metabolism, and reproductive investment, an almost entirely unexplored area. Using multiple species and life stages, I demonstrated that dehydrated animals typically have enhanced innate immunity, regardless of whether the dehydration is a result of seasonal water constraints, water deprivation in the lab, or high physiological demand for water. My work contributed greatly to the understanding of immune function dynamics and lays a foundation for the study of hydration immunology as a component of the burgeoning field of ecoimmunology. While a large portion of my dissertation focused on the interaction between water balance and immune function, there are many other physiological processes that may be impacted by water restrictions. Accordingly, I recently expanded the understanding of how reproductive females can alter metabolic substrates to reallocate internal water during times of water scarcity, an important development in our knowledge of reproductive investments. Overall, by thoroughly evaluating implications and responses to water limitations, my dissertation, when combined previous acquired knowledge on food limitation, will enable scientists to better predict the impacts of future climate change, where, in many regions, rainfall events are forecasted to be less reliable, resulting in more frequent drought. / Dissertation/Thesis / Doctoral Dissertation Biology 2019
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Variabilidad en la práctica clínica sobre el uso de la hipodermoclisis en pacientes al final de la vidaVelasco Álvarez, María Luisa 01 June 2016 (has links)
No description available.
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Energetics of Home Dehydration; The Effect on Product Cost and QualityWillis, Crystal A. 01 May 1980 (has links)
The purpose of this study was two-fold: (1) to compare different home dehydrators and determine if the operation and design of the home dehydrators affected the color, cost, nutrient content, acceptability or flavor of the resulting products and (2) to determine the effect of physical parameters on product color, nutrient content, acceptability and flavor. The physical parameters that were measured during the dehydration process were temperature, relative humidity, and mass flow rate of air. Two products, Daucus carota var sativa (carrot) and juice of Lycopersicon sp. (tomato), were dried in each of six dehydrators (treatments). A sensory panel was used to determine the color, acceptability and flavor differences in dehydrated carrots and tomato juice form the different treatments. Carotene and ascorbic acid content were determined in the carrots and tomato juice, respectively. The total cost of dehydration was calculated by summing the fresh produce cost, energy costs, equipment and cost of labor.
The design and operation of the five dehydrators designated for home use had significantly different effects on the cost, color, flavor, and acceptability of both carrots and tomato juice. Ascorbic acid content in dehydrated tomato juice production from the six dehydrators differed significantly, but, the carotene content of dehydrated carrots did not differ statistically between treatments.
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Multiphase, Multicomponent Systems: Divalent Ionic Surfactant Phases and Single-Particle Engineering of Protein and Polymer GlassesRickard, Deborah January 2011 (has links)
<p>This thesis presents an analysis of the material properties and phase behavior of divalent ionic surfactant salts, and protein and polymer glasses. There has been extensive interest in understanding the phase behavior of divalent ionic surfactants due to the many applications of ionic surfactants in which they come into contact with divalent ions, such as detergency, oil recovery, and surfactant separation processes. One goal of determining the phase boundaries was to explore the option of incorporating a hydrophobic molecule into the solid phase through the micelle-to-crystal bilayer transition, either for drug delivery applications (with a biologically compatible surfactant) or for the purpose of studying the hydrophobic molecule itself. The liquid micellar and solid crystal phases of the alkaline earth metal dodecyl sulfates were investigated using calorimetry, visual inspection, solubilization of a fluorescent probe, and x-ray diffraction. The Krafft temperature and dissolution enthalpy were determined for each surfactant, and partial composition-temperature phase diagrams of magnesium dodecyl sulfate-water, calcium dodecyl sulfate-water, as well as sodium dodecyl sulfate with MgCl<sub>2</sub> and CaCl<sub>2</sub> are presented. As a proof of concept, fluorescence microscopy images showed that it is, in fact, possible to incorporate a small hydrophobic molecule, diphenylhexatriene, into the solid phase.</p><p>The second, and main, part of this thesis expands on work done previously in the lab by using the micropipette technique to study two-phase microsystems. These microsystems consist of a liquid droplet suspended in a second, immiscible liquid medium, and can serve as direct single-particle studies of drug delivery systems that are formed using solvent extraction (e.g., protein encapsulated in a biodegradable polymer), and as model systems with which to study the materials and principles that govern particle formation. The assumptions of the Epstein-Plesset model, which predicts the rate of droplet dissolution, are examined in the context of the micropipette technique. A modification to the model is presented that accounts for the effect a solute has on the dissolution rate. The modification is based on the assumption that the droplet interface is in local thermodynamic equilibrium, and that the water activity in a solution droplet can be used to determine its dissolution (or dehydration) rate. The model successfully predicts the dissolution rates of NaCl solutions into octanol and butyl acetate up to the point of NaCl crystallization. The dehydration of protein solutions (lysozyme or bovine serum albumin) results in glassified microbeads with less than a monolayer of water coverage per protein molecule, which can be controlled by the water activity of the surrounding organic medium. The kinetics of dehydration match the prediction of the activity-based model, and it is shown how the micropipette technique can be used to study the effect of dissolution rate on final particle morphology. By using a stable protein with a simple geometry (lyosyzme), this technique was be used to determine the distance dependence of protein-protein interactions in the range of 2-25 Å, providing the first calculation of the hydration pressure decay length for globular proteins. The distance-dependence of the interaction potential at distances less than 9 Å was found to have a decay length of 1.7 Å, which is consistent with the known decay length of hydration pressure between other biological materials. Biodegradable polyesters, such as poly(lactide-co-glycolide) (PLGA), are some of the most common materials used for the encapsulation of therapeutics in microspheres for long-term drug release. Since they degrade by hydrolysis, release rates depend on water uptake, which can be affected by processing parameters and the material properties of the encapsulated drug. The micropipette technique allows observations not possible on any bulk preparation method. Single-particle observations of microsphere formation (organic solvent extraction into a surrounding aqueous phase) show that as solvent leaves the microsphere and the water concentration in the polymer matrix becomes supersaturated, water phase separates and inclusions initially grow quickly. Once the concentration in the polymer matrix equilibrates with the surrounding aqueous medium, the water inclusions continue to grow due to dissolved impurities, solvent, and/or water-soluble polymer fragments resulting from hydrolysis, all of which locally lower the water activity in the inclusion. Experiments are also presented in which glassified protein microbeads were suspended in PLGA solution prior to forming the single microspheres. This technique allowed the concentration of protein in a single microbead/inclusion to be determined as a function of time.</p> / Dissertation
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Effects of plasma osmolality on red cell sizeBranam, Lois Marie 03 June 2011 (has links)
The changes in plasma osmolality and percentage change in mean corpuscular volume accompanying dehydration (2~ and 4of body weight loss) were studied to assess the use of the venous hematocrit as a gauge of the percentage change in plasma volume. In vitro experiments were also conducted to verify the relationship between plasma osmolality and mean corpuscular volume.By utilizing the mean corpuscular hemoglobin concentration, calculation of the percentage change in mean corpuscular volume following dehydration showed a marked shrinkage of the red cells that was significantly related to the increase in plasma osmolality (r = - 0.99). Consequently, it was concluded that calculations of the percentage change in plasma volume during dehydration based on the change in venous hematocrit are subject to error unless corrections are made for alterations in mean corpuscular volume.Ball State UniversityMuncie, IN 47306
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New dehydration and pretreatment process for ethanol production from biomassKanchanalai, Pakkapol 08 June 2015 (has links)
The cost of pretreatment process for saccharification from biomass and the cost of dilute ethanol purification are significant components of the overall cost for fuel grade ethanol production through fermentation or other biological routes. This work focuses on developing optimal designs of dilute ethanol purification process and the new acid hydrolysis technology for the production of fermentable sugars from biomass where the overarching goal is to reduce the cost of ethanol production from biomass. In this thesis, the ethanol separation process with the reverse osmosis membrane pretreatment is developed to reduce separation cost and energy consumption especially when the feed is dilute. In addition, the new solid phase reactive separation system for biomass saccharification via acid hydrolysis is proposed. This new process is applied for both dilute and concentrated acid hydrolysis where the goal is to increase sugar yield and to reduce byproduct formation. The reaction kinetics of the concentrated acid hydrolysis is investigated through batch experiment. All of these use optimization approaches for seeking the best process designs and for parameter estimations.
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Att motverka dehydrering hos äldre i teori och praktikArneson, Sofia January 2015 (has links)
Syfte: Att kartlägga likheter och skillnader i åtgärder och hjälpmedel mot dehydrering hos äldre i teori och praktik. Metod: Initialt utfördes litteraturstudier via universitetsbibliotekets söktjänst OneSearch. Tre intervjuer utfördes på undersköterskor på gruppboende, demensboende och hemtjänst. Dessa erbjuder en inblick i den praktiska verksamheten. Resultat: Följande faktorer av betydelse för att förebygga eller motverka dehydrering identifierades samstämmigt i litteratur och vid intervjuer: (1) kunskap om den äldre via dokumentation, (2) anpassning av tillvägagångssätt vid servering av dryck efter den äldres preferenser och tillstånd, (3) hemtrevlig miljö med sociala interaktioner, (4) bedömning av vätskeintag, väskebalans och riskfaktorer via uppmärksamhet, vätskeregistrering och med hjälp av flera andra yrkesgrupper samt med hänsyn till den äldres historik, (5) påminnelser (särskilt vid demens) och en stor mängd lättabsorberade drycker som intas succesivt vid diarré och kräkningar, (6) lättanvända och specialutformade hjälpmedel. Följande metoder särskilde sig: (1) utbildning för vårdare; begränsad på de undersökta platserna, (2) tekniska hjälpmedel och sväljterapi (kostmodifieringar, anpassade huvudpositioner, sväljträning) vid dysfagi; kostmodifieringar används på de undersökta platserna, (3) färgsättning av koppar och kannor, vilket visats kunna ha betydelse för intag. Slutsats: Skillnader fanns gällande utbildning och användning av sväljterapi, tekniska hjälpmedel och infusioner. Utbildning av personalen, mer frekvent vätskeregistrering och fullständig sväljterapi utgör förbättringsmöjligheter. Vissa av dessa åtgärder kräver ökade resurser och/eller tydliga riktlinjer. Acceptans för tekniska hjälpmedel är inte en självklarhet. Undersökningar gällande möjligheterna i att med färgval och design av dryckeskärl stimulera de äldre att dricka mer kan vara värt att undersöka vidare. Intervjuerna syftade främst till att ge en inblick i den praktiska verksamheten och generaliserbarheten av erhållna resultat är begränsad. De flesta åtgärder som har identifierats är ”mjuka” till sin karaktär. Det är svårt att få en klar bild av olika metoders effektivitet. Några av metoderna som har utvärderats med goda resultat vid dysfagi och som därför kan förbättra vätskeintaget är sväljterapi och stimulering av sväljmuskulatur. / Objective: To identify similarities and differences in methods and aids used to prevent dehydraton in the elderly as identified from the scientific literature and from interviews with caretakers. Method: Literature studies was performed through the University Library search service ”OneSearch” and further from references in key papers. Three interviews were conducted on nursing assistants in two retirement homes and home care services, to offer some insight into the practical activities. Results : The following factors were identified as important in both literature and interviews: (1) knowledge of the elderly through documentation, (2) adapted approach when serving drinks after the elderly person's preferences and condition, (3) a homely environment with social interactions, (4) assessments of fluid intake, fluid balance and risk factors through attention, fluid registration and with the help of several other professional groups, and given the history of the elderly, (5) reminders for dementia and a accessibility of large amount of easily absorbed beverages consumed gradually during diarrhea and vomiting, (6) easy-to-use and specially designed drinking aids. For the following factors differences were obeserved between literature survey and interviews: (1) education for caregivers; limited to the investigated sites, (2) technical aids and swallowing therapy (dietary modifications, adapted head positions, swallowing training) in dysphagia; diet modification is used at the investigated sites (3) the importance of cup and jug colours; blue cups used in practice, no support in literature. Conclusions: Differences were found in terms of education and the use of swallowing therapy, assistive technology and infusions. Education, more frequent fluid registration and a complete swallowing therapy are improvement opportunites, some of them requires extra resources and/or clear guidelines. Acceptance of technical aids is not self-evident. Investigation of the effect of cup color and design that can encourage the elderly to drink could potentially be a way forward. The results of the interviews are not generalizable because they only aimed to give an insight into the practical activities. Most of the strategies that have been identified are "soft" in nature. It is difficult to get a clear picture of the efficiency of different methods. Methods that have been evaluated with good results in dysphagia and therefore offer potential to improve liquid intake, are swallowing therapy and stimulation of swallowing musculature.
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The effects of varying hydration conditions on the estimation of body composition by bioelectrical impedance analysis, near infrared interactance, and dual-energy x-ray absorptiometryLiparulo, Timothy L. January 2001 (has links)
The purpose of this study was to examine the effects of hydration status on the prediction of body composition using BIA, NIR, and DEXA. Twenty healthy males and females ages 18 to 28 were recruited for this study. The subjects were dehydrated in the climate control chamber and engaged in physical exercise, until they lost approximately 1%, 2%, and 3% of their pre-exercise body weight. Percent body fat (%BF), body weight, and urinalysis measures were taken initially on day 1, on day 4 at euhydration, following 1%, 2%, and 3% dehydration, and upon rehydration during day 5. The results indicated that there were significant decreases for %BFBIA and %BFNIR between euhydration and 1%, 2%, and 3% dehydration. %BFDExA did not significantly change.There were also significant differences in the response to dehydration between each technique. Proper hydration should be ensured before %BF is estimated with BIA and NIR. / School of Physical Education
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Fluid replacement after exercise in the heat : influence of beverage carbonation and carbohydrate contentLambert, Charles Paul January 1990 (has links)
This investigation evaluated the Influence of beverage carbonation and carbohydrate content on fluid replacement following exercise/thermal dehydration. Eight recreationally trained men cycled at 50% of their maximal aerobic power in a hot environment (40°C 40% relative humidity) until a body weight loss of 4.12 ± 0.02% was attained. In the subsequent four hours subjects ingested one of four randomly assigned solutions at 15 minute intervals. The total volume ingested equalled that lost during dehydration. The solutions varied in their carbohydrate and carbonation content as follows: 1) CK: carbonated 10% carbohydrate solution, 2) NCK: non-carbonated 10% carbohydrate solution, 3) CNK: carbonated non-caloric solution, and 4) NCNK: non-carbonated non-caloric solution. Before dehydration and at 0, 60, 120, 180, and 240 minutes of recovery subjects performed a five minute cycling bout (SCB) at 70% venous blood samples were obtained before and after dehydration, and at 30, 90, 150, and 240 minutes of of their maximal aerobic power. In addition, resting data from the carbohydrate treatments were pooled and recovery. Rehydration evaluated from body weight, plasma volume, plasma protein, and urine volume data was not significantly (p> 0.05) different between treatments at any time. In addition, carbonated beverage (CK and CNK) ingestion did not significantly alter the pC02 or pH of venous blood at rest or the respiratory exchange ratio (RER) during exercise, however, the ingestion of carbohydrate beverages (CK and NCK) elevated the RER during the SCB relative to the level elicited by Ingestion of non-carbohydrate beverages. Oxygen consumption during the SCB at 240 minutes was significantly (p< 0.05) higher in the non-carbohydrate treatments (NCNK vs. CK and CNK and NCNK vs. NCK), however, no differences in caloric expenditure were observed. Arterialized blood lactate one minute after each SCB was not different between treatments. Lactate levels were significantly higher, however, when compared to the non-carbohydrate treatments. No significant differences were observed in ratings of perceived exertion, or ratings of gastrointestinal comfort. The results of this Investigation suggest that solutions which are carbonated and/or contain a carbohydrate concentration of 10 b are as effective as non-carbonated and/or non-carbohydrate solutions with regard to fluid replacement. In addition, the ingestion of carbonated beverages does not appear to be associated with alterations in the pC02 or pH of venous blood or gastric distress relative to the levels attained with non-carbonated beverages. / School of Physical Education
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An assessment of pediatric nurse practitioners' use of clinical criteria for evaluating the hydration status of children a research report submitted in partial fulfillment ... /Hanson, Marilyn E. January 1989 (has links)
Thesis (M.S.)--University of Michigan, 1989.
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