Evaluation of origin-depended nitrogen input through atmospheric deposition and its effect on primary production in coastal areas of western Kyusyu, Japan.

Long term monitoring of atmospheric wet and dry depositions and associated nutrients fluxes was conducted on the coast of Japan facing the East China Sea continuously for 1 year and 2 months, with the origin of air mass investigated based on isotope analyses (Sr, Nd, and NO3). During the same period, intensive observations of ocean conditions and the chemical composition of sinking particles collected using sediment traps were conducted to investigate the effects of atmospheric deposition-derived nutrients on phytoplankton blooms. Dry-deposition-derived nutrient inputs to the surface ocean were larger during autumn to spring than in summer due to the effect of continental air mass occasionally carrying Asian dust (yellow sand). However, these nutrients fluxes were limited (1.1-1.5 mg-N m-2 day-1 on average) and didn't appear to cause phytoplankton blooms through the year. Although average dissolved inorganic nitrogen (DIN) concentrations in rainwater were lower in oceanic air masses compared to continental air masses, wet-deposition-derived nutrient inputs to the surface ocean on rainy days during the summer (26.0 mg-N m-2 day-1 on average) were large due to higher precipitation from oceanic air masses. Wet-deposition-derived nutrients significantly increased nutrient concentrations in the surface ocean and seemed to cause phytoplankton blooms in the warm rainy season when nutrients in the surface were depleted due to increased stratification. The increase in phytoplankton biomass was reflected in increased particle sinking into the bottom layer, as well as changing chemical characteristics. The supply of flesh phytoplankton-derived labile organic matter into the bottom layer could be expected to promote rapid bacterial decomposition and contribute to the formation of hypoxic water masses in early summer when the ocean was strongly stratified. Atmospheric deposition-derived nutrients in East Asia will have important impacts on not only the oligotrophic outer ocean but also surrounding coastal areas in the warm rainy season.

Hepatic screlosed hemangioma which was misdiagnosed as metastasis of gastric cancer: report of a case.

A screlosed hemangioma of the liver is rare among hepatic tumors. A 75 years old male was referred to our hospital for gastric cancer and a hepatic tumor. The histological finding of gastric cancer was revealed to be well differentiated adenocarcinoma. The liver tumor was 1.1×1.0 cm in size and located in segment 8 of the liver. Computed tomography (CT) showed it to be a tumor with ring enhancement. Magnetic resonance imaging (MRI) showed the tumor to have a low signal on T1-weighted and slightly high signal on T2-weighted images. Level of hemoglobin was 7.8 g/dl. It was thought to be persistent bleeding from gastric cancer. With diagnosis of liver metastasis from gastric cancer, chemotherapy is recommended. However, to control the bleeding from gastric cancer, we performed distal gastrectomy and wedge resection of liver (S8). The histological examination of the liver tumor revealed to be a hepatic sclerosed hemangioma with hyalinized tissue and collagen fibers. We report herein a case of the rare tumor which was misdiagnosed as a liver metastasis of gastric cancer.

Surgical results of pancreatoduodenectomy in elderly patients.

PURPOSE: To assess the safety and feasibility of pancreatoduodenectomy (PD) in elderly patients, we investigated the clinical characteristics of patients aged ≥75 years, who underwent this procedure at our hospital. METHODS: Between November 2005 and December 2010, 84 patients underwent PD at Tokushima University Hospital. We analyzed the clinicopathological data and outcomes after PD in patients aged ≥75 years compared with those in patients <75 years. RESULTS: The preoperative characteristics of the elderly group (n = 28) were similar to those of the younger group (n = 56). The hemoglobin and albumin levels were significantly lower in the elderly patients (P < 0.05), who also had a higher rate of preoperative pulmonary dysfunction (P < 0.05). The operation time and intraoperative blood loss did not differ significantly between the groups, but the incidence of pneumonia was higher in the elderly group (P < 0.05). The overall survival rate did not differ significantly between the groups. CONCLUSION: Advanced age alone does not have an adverse effect on surgical outcomes, including postoperative complications and long-term prognosis. Therefore, PD may be justified for selected elderly patients.

Effect of agriculture on water quality of Lake Biwa tributaries, Japan.

We investigated the effects of natural environments and human activity on Lake Biwa, central Japan. We determined the concentrations of 19 elements and the compositions of stable S and Sr isotopes in the main tributaries of the lake and compared them with the corresponding values obtained from the lake water during the circulation period. Results of a principal component analysis indicated that the components dissolved in the lower reaches of the tributaries can be divided into group 1 (HCO(3), SO(4), NO(3), Ca, Mg, Sr) and group 2 components (Cl, Br, Na, K, Ba, Rb, Cs). The concentrations of group 1 components were high in the rivers of the southern area, which is urbanized and densely populated, and the eastern area, which consists of plains where agriculture predominates, compared with the rivers of the northern and western areas, which are mostly mountainous and sparsely populated. The concentrations of group 2 components tended to be high in the river water of industrial areas. The delta(34)S values of SO(4) in the river water converged to 0+/-2 per thousand as the SO(4) concentration increased and, excluding the areas where limestone is extensively distributed, as the HCO(3) concentration increased. In particular, both the delta(34)S values (0+/-2 per thousand) and the (87)Sr/(86)Sr ratios (0.7117+/-0.0005) fell within narrow ranges in the small and medium rivers of the eastern plain area, where rice is widely grown. These values agreed respectively with the delta(34)S values of the fertilizers used in the Lake Biwa basin and the soil-exchangeable (87)Sr/(86)Sr in the eastern plain. The characteristics of water quality in the small and medium rivers of the eastern area can be explained by a model in which sulfuric, nitric, and bicarbonic acids generated by the decomposition of agricultural fertilizer and paddy rice selectively leached out alkaline-earth elements adsorbed on the soil and sediments of the plain or dissolved calcium carbonate enriched with Mg and Sr. Compared with tributary waters, the lake water was depleted in NO(3), owing to denitrification, and in Mn, owing to mineralization, which occur under the redox condition of bottom sediments. Excluding NO(3) and Mn, the compositions of both the dissolved elements and the Sr and S isotopes in the water of Lake Biwa can be approximately reproduced by simple mixing of the tributary water, indicating that these components provide effective indices for evaluating the relationship between the waters of the lake and its tributaries.

Faraday instability of superfluid surface.

We observed that Faraday waves are parametrically generated on a free surface of superfluid 4He when a sample cell is vibrated vertically. Standing-wave patterns appear on the surface, and their frequencies are one-half the driving frequency. We observed clear threshold amplitudes of the vibration for the instability. The difference in the threshold between the superfluid and the normal fluid is explained by a wall damping.