Sodium (Na) is the most abundant electrolyte in the extracellular fluid and is essential to life. The physiological level of Na in body fluids is constantly maintained. When experimental animals are deprived of sodium, they show an appetite for salt. Although many analyses of the mechanism of salt appetite have been made, there are still many unknown factors. As an implication for the regulatory relation between sodium and other minerals, it has also been reported that NaCl preference increases with a deficiency in calcium or zinc. We previously reported that NaCl preference increases in zinc-deficient rats even after a few days of deficiency. We also found that short-term zinc deficiency decreases hypothalamus hormone secretion, however, the chorda tympani nerve responses to NaCl were maintained and only significantly reduced later with prolonged zinc deficiency. These findings suggest that zinc deficiency may influence sodium metabolism, as the result of a combination of peripheral taste nerve and central nervous system.

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Sodium (Na) is distributed in extra-cellular fluid by approximately 90%. As there is less movement of Na across cell membranes, the serum Na level is dependent upon Na content and circulatory blood volume. Urinary concentration ability contributes to homeostasis of body water, that is, renal medullary hypertonicity and release and the renal action of arginine vasopressin (AVP). Also drinking behavior is involved in water homeostasis. Disorders of water metabolism causes hyper-and hypo volemic states, which are related to hyponatremia and hypernatremia, respectively.
Serum Na levels range from 136 to 145 mmol/l, and hyponatremia defined as serum Na levels are less than 135 mmol/l. Hyponatremia is classified into 3 groups; hypovolemic, euvolemic and hypervolemic hyponatremia. Hypovolemic hyponatremia is primarily caused by renal and extra-renal Na loss, including Addison's disease, Na-losing nephritis, renal tubular acidosis, diuretic abuse, diarrhea, vomiting and so on. Exaggerated release of AVP produces euvolemic hyponatremia, such as the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), hypopituitarism and hypothyroidism. Renal sodium handling disturbance in elderly subjects causes mineralocorticoid-responsive hyponatremia in the elderly (MRHE). Hypervolemic hyponatremia is found in edematous disorders, including congestive heart failure, liver cirrhosis and nephrotic syndrome. The symptoms of hyponatremia are nausea, vomiting, appetite loss, conscious disturbance and convulsions. Severe hyponatremia below 120 mmol/l should be corrected to maintain more than 125 mmol/l in any groups of hyponatremia. After keeping serum Na greater than 125 mmol/l, diagnosis and specific treatment must be performed.

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The authors have developed application research for “Wild Plants Water Extract Minerals; WPE-Minerals” as an ingredient for making safe and high-quality foods. In this report, we investigated additional effectiveness on Sio-Tarako and Karashi-mentaiko, especially in terms of as tone improvement, free amino acid penetration, and increase of useful minerals. Additional amount of WPE-Minerals were at 0.05w/w% of cod roe weight in the salt-preserved process of Sio-Tarako and Karashi-mentaiko. In the results, it is clear that additional WPE-Minerals Sio-Tarako samples were brighter than no-addition WPE-Minerals Sio-Tarako samples. The amount of free amino acids in both added WPE-Minerals Sio-Tarako and Karashi-mentaiko samples increased due to permeation of glutamic acid as an Umami ingredient, and also the amount of six kinds of useful minerals increased remarkably.

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The salt tolerance of trees was evaluated in order to select species for salt affected land afforestation. In the Wheatbelt of Western Australia, native trees have been cleared and the land converted to crop cultivation which recently resulted in the rise of ground water levels and salt accumulation on the soil surface. In order to rehabilitate the land and increase the wheat yield, partial reforestation is required. In addition, the high growth rate of trees contributes to the decrease in carbon dioxide concentration in the atmosphere and mitigates global climate change issues. In the present study, the survival limitation was experimentally determined for eight tree species by periodically increasing the salt concentration in the irrigation water with the control conditions of fresh water irrigation. The growth of the trees was evaluated by the tree height. The tree species with high survival rates during salty water irrigation generally showed small growth rates under the salt water irrigation condition and small final mass under the control conditions. Only the native hybrid species of Eucalyptus rudis×E. camaldulensis showed extremely high growth rates with high survival rates under salty water irrigation conditions. This species was thought to be the optimum tree species for afforestation in saline land.

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Major and trace elements such as manganese, iron, scandium, antimony, lanthanoids, thorium and uranium were determined by instrumental neutron activation analysis (INAA) in marine sediment core samples collected from Kagoshima Bay and Shimabara Bay in the Kyushu region of Japan. The following findings were obtained.(1) In the Kagoshima Bay core sediments, it was indicated from the vertical profile of manganese and the Th/U-Ce/U plot that the cores below the surface were under reducing conditions, particularly the lower cores.(2) In the Shimabara Bay core sediments, the concentrations of manganese and iron were comparatively high between 20 and 60mm in depth, indicating oxidizing conditions at that depth, a finding that was consistent with the result from the Th/U-Ce/U plot.(3) It could be considered that the sediments from Shimabara Bay had been significantly affected by terrigenous materials judging from the lanthanoid abundance ratios, and a higher Th/Sc ratio showed the origin was mainly detritus of granitic rocks.(4) The concentrations of antimony in the Kagoshima Bay sediments were several times higher than those in the Shimabara Bay sediments, which is probably related to the hydrothermal activity of the submarine volcano (Wakamiko Caldera) in the vicinity.

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The purpose of the experiments was to analyze the phenomenon of hydration on cooked rice that was soaked in various solutions. The solutions used for analysis were alkali metal chloride, alkaline earth metalchloride, saccharide, and alcohol solutions. The rice grains, outer layers were removed and germ were polished by levels of 90% or 50%. The materials soaked in the solutions were boiled rice that was cooked using an electric rice cooker. The volumes of 90% and 50% boiled rice soaked in alkali metal chloride, alkaline earth metal chloride, and saccharide solutions were small in order of the dynamic hydration number. The breaking stress of boiled rice soaked in alkali metal chloride and saccharide solutions was large in order of the dynamic hydration number. The correlation coefficient between volume and breaking stress was a minus value on the 90% and 50% cooked rice soaked in alkali metal chloride and saccharide solutions. Based on the dynamic hydration number of the coexisting materials, 90% and 50% cooked rice soaked in alkali metal chloride and saccharide solutions were hard, while the volume was small. We found that those dynamic hydration numbers with coexisting materials in the solutions affected the rheological properties of cooked rice.

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Substrates for seaweed culture with recycled glass powder and foaming agent were prepared. To simulate manufacturing conditions, 5% addition of foaming agent and a sintering temperature of 790°C were most suitable. The substrates on which saprophytes (seedling) of brown alga Ecklonia kurome were attached were submerged in seawater at St 1 in the Yatsushiro Sea. However, cultivation was not successful because of the predation of some fish. The thin rope (1.2m long) on which the saprophytes of brown alga Laminaria japonica were attached were surrounded on the substrate (14cm×16cm), and was cultured in the sea (St. 2) beginning 26 December, 2005. The growth was monitored monthly, and the final growth at 199 cm in maximum blade length, 11.9cm in maximum blade width and 112g in maximum individual wet weight were obtained on 12 May, 2006. The number of fronds per substrate was 66, and the final yield during this period was 3.7kg. From the results, an attempt to utilize recycled glass as a substrate for seaweed cultures was considered to be successful.

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