kaolinite and Dehydration

Treatment and control of acute neonatal diarrhea in calves are outlined and discussed. The difficulty in making a definitive etiological diagnosis makes effective treatment and control also difficult and largely empirical. Physiological events in calves with diarrhea are known, and fluid therapy is directed toward treating dehydration and acidosis. Whether affected calves should receive antibacterial agents orally is an open question. Principles of control of diarrhea in calves are outlined and discussed.

Topics: Animals; Animals, Newborn; Anti-Bacterial Agents; Bicarbonates; Cattle; Cattle Diseases; Colostrum; Dehydration; Diarrhea; Diet; Escherichia coli Infections; Glucose; Glycine; Housing, Animal; Infusions, Parenteral; Kaolin; Phosphates; Potassium Chloride; Reoviridae Infections; Salmonella Infections, Animal; Sodium Chloride

Topics: Acidosis; Anthelmintics; Anti-Bacterial Agents; Candidiasis; Child; Dehydration; Diarrhea; Dysentery, Amebic; Dysentery, Bacillary; Escherichia coli Infections; Giardiasis; Humans; Intestinal Diseases, Parasitic; Kaolin; Lactose; Parasympatholytics; Pectins; Salmonella Infections

Regarding the foreseeing climate change is reasonable to expect harmful consequences to olive tree (Olea europaea L.), an iconic species of Mediterranean region. Thus, the selection of practices that allow a better drought resistance and recovery capacity needs the immediate attention of scientific community. This study evaluates the strategies adopted by young potted olive trees, subjected to three cycles of drought and rewatering, in the presence of a reflective clay, kaolin (KL). The results demonstrated that KL induced shade-related leaf structural changes and was effective in keeping leaf water status during the most stressful periods. In general, photosynthetic activity of sprayed plants was improved by the alleviation of drought-induced stomatal and non-stomatal limitations. Moreover, during stress imposition sprayed leaves showed reduced oxidative damages, allowing lower investment in antioxidant defences. Furthermore, sprayed plants also had lower nighttime water losses due to inferior nighttime stomatal conductance, and are able to maintain higher respiration rates. Upon rewatering, the shaded effect conferred by KL limited gas exchange restauration, but improved the plants' capacity to restore the metabolic functions. In spite of the induced physiological and biochemical changes, no significant differences were found in whole-plant water use efficiency and plant biomass accumulation, possibly by the attenuation of photosynthesis restauration during the recovery events. In conclusion, the changes induced by KL might be beneficial under severe conditions, as on realistic Mediterranean field environments.

Topics: Dehydration; Kaolin; Membranes, Artificial; Olea; Plant Stomata; Water

Viticulture is widely practiced in dry regions, where the grapevine is greatly exposed to water stress. Optimizing plant water use efficiency (WUE) without affecting crop yield, grape and wine quality is crucial to limiting use of water for irrigation and to significantly improving viticulture sustainability. This study examines the use in vineyards of particle film technology (engineered kaolin) and compares it to a film-forming antitranspirant (pinolene), traditionally used to limit leaf water loss, and to an untreated control. The trial was carried out under field conditions over three growing seasons, during which moderate to very severe plant water stress (down to -1.9 MPa) was measured through stem water potential. Leaf stomatal conductance (gs) and photosynthesis rate (An) were measured during the seasons and used to compute intrinsic WUE (WUEi, defined as An/gs ratio). Leaf temperature was also recorded and compared between treatments. Bunch quantity, bunch and berry weight, sugar accumulation, anthocyanin and flavonoid contents were measured. Finally, microvinifications were performed and resultant wines subjected to sensory evaluation.Results showed that the use of kaolin increased grapevine intrinsic WUE (+18% on average as compared to unsprayed vines) without affecting berry and bunch weight and quantity, or sugar level. Anthocyanin content increased (+35%) in kaolin treatment, and the wine was judged more attractive (p-value <0.05) and slightly more appreciated (p-value < 0.1) than control. Pinolene did not increase WUEi, limiting An more than gs; grapes with this treatment contained lower sugar and anthocyanin content than control, and the obtained wine was the least appreciated. This study demonstrates that particle film technology can improve vine WUEi and wine quality at the same time, while traditional antitranspirants were not as effective for these purposes. This positive effect can be used in interaction with other already-demonstrated uses of particle film technology, such as pest control and sunburn reduction, in order to achieve more sustainable vineyard management.

Topics: Agriculture; Dehydration; Droughts; Kaolin; Plant Diseases; Plant Leaves; Terpenes; Vitis; Water; Water Resources; Wine

Kaolin applications have been used to mitigate the negative effects of water and heat stress on plant physiology and productivity with variable results, ranging from increased to decreased yields and photosynthetic rates. The mechanisms of action of kaolin applications are not clear: although the increased albedo reduces leaf temperature and the consequent heat stress, it also reduces the light available for photosynthesis, possibly offsetting benefits of lower temperature. The objective of this study was to investigate which of these effects are prevalent and under which conditions.. A 6% kaolin suspension was applied on well-irrigated and water-stressed walnut (Juglans regia) and almond (Prunus dulcis) trees. Water status (i.e. stem water potential, psi(s)), gas exchange (i.e. light-saturated CO2 assimilation rate, Amax; stomatal conductance, g(s)), leaf temperature (T(l)) and physiological relationships in treated and control trees were then measured and compared.. In both species, kaolin did not affect the daily course of psi(s) whereas it reduced Amax by 1-4 micromol CO2 m(-2) s(-1) throughout the day in all combinations of species and irrigation treatments. Kaolin did not reduce g(s) in any situation. Consequently, intercellular CO2 concentration (C(i)) was always greater in treated trees than in controls, suggesting that the reduction of Amax with kaolin was not due to stomatal limitations. Kaolin reduced leaf temperature (T(l)) by about 1-3 degrees C and leaf-to-air vapour pressure difference (VPD(l)) by about 0.1-0.7 kPa. Amax was lower at all values of g(s), T(l) and VPD(l) in kaolin-treated trees. Kaolin affected the photosynthetic response to the photosynthetically active radiation (PAR) in almond leaves: kaolin-coated leaves had similar dark respiration rates and light-saturated photosynthesis, but a higher light compensation point and lower apparent quantum yield, while the photosynthetic light-response curve saturated at higher PAR. When these parameters were used to model the photosynthetic response curve to PAR, it was estimated that the kaolin film allowed 63% of the incident PAR to reach the leaf.. The main effect of kaolin application was the reduction, albeit minor, of photosynthesis, which appeared to be related to the shading of the leaves. The reduction in T(l) and VPD(l) with kaolin did not suffice to mitigate the adverse effects of heat and water stress on Amax.

Topics: Carbon Dioxide; Dehydration; Juglans; Kaolin; Light; Photosynthesis; Plant Leaves; Plant Stems; Prunus; Temperature; Water

Lomotil liquid in a dose of 0.3 mg/kg/day has been compared with plain mist kaolin in controlling acute diarrhoea in young children aged 6 weeks to 2 years. Lomotil was found to stop the diarrhoea faster and significantly shorten the period of hospital admission than kaolin (P less than 0.05) in children whose diarrhoea was complicated by moderate dehydration. In those with mild dehydration lomotil had no advantage over kaolin. Children with severe dehydration treated with lomotil spent on the average much shorter period in hospital than those on kaolin, but the numbers were too small to allow for useful comparison. There was no adverse effect observed in any of subjects at the dose of lomotil used.

Topics: Acute Disease; Dehydration; Diarrhea, Infantile; Diphenoxylate; Female; Humans; Infant; Isonipecotic Acids; Kaolin; Male

Topics: Adult; Colitis, Ulcerative; Dehydration; Diarrhea; Diphenoxylate; Dysentery, Amebic; Humans; Infusions, Parenteral; Kaolin; Morphine; Sodium Chloride; Sulfasalazine; Travel; Water-Electrolyte Balance