Seasonal variations of water column nutrients in the inner area of Ariake Bay, Japan: the role of muddy sediments.

To investigate seasonal variations of nutrient distribution in the mudflat-shallow water system, we conducted field surveys once a month from August 2007 to July 2008 in the inner area of Ariake Bay (IAB), Japan. The NH4 (+)-N concentration of the water column increased in autumn because of the high NH4 (+) release from the sediments, ranging from 850 to 3,001 µmol m(-2) day(-1). The NO3 (-)-N concentration was maximal in January, which was thought to be caused by NO3 (-) release from the oxic sediments and by NO3 (-) regeneration due to water column nitrification. The PO4 (3-)-P concentration of the water column was high in summer-autumn due to the high PO4 (3-) release from the reduced sediments, ranging from 22 to 164 µmol m(-2) day(-1). We estimated the total amounts of DIN and PO4 (3-)-P release (R DIN and [Formula: see text], respectively) from the muddy sediment area of the IAB. In summer-autumn, R DIN and [Formula: see text] corresponded to about 47.7 % of DIN input and about 116.6 % of PO4 (3-)-P input from the river, respectively. Thus, we concluded that the muddy sediments were an important source of nutrients for the water column of the IAB during summer-autumn. In addition, we found that phosphorus necessary for the growth of Porphyra (Porphyra yezoensis, Rhodophyceae) would be insufficient in the water column when phosphorus during the Porphyra aquaculture period is supplied only from the river. Therefore, the phosphorus release from the muddy sediments was thought to play an important role in the sustainable production of Porphyra in Ariake Bay.

Gender differences in coronary plaque characteristics in patients with stable angina: a virtual histology intravascular ultrasound study.

The purpose of this study was to compare culprit coronary plaque characteristics between female and male patients with stable angina using virtual histology intravascular ultrasound (VH-IVUS). The target population consisted of three hundred and sixty-four consecutive patients with stable angina who underwent percutaneous coronary intervention (PCI) after VH-IVUS. The baseline characteristics and VH-IVUS results were compared between 72 female and 292 male patients. Culprit coronary plaque histological composition ratios, which were classified as fibrous (FI)%, fibro-fatty (FF)%, dense-calcium (DC)% and necrotic core (NC)%, were evaluated by VH-IVUS. The HbA1c (6.4 ± 1.2% vs. 5.9 ± 1.0%, p < 0.0001), total cholesterol (202 ± 33 mg/dL vs. 189 ± 34 mg/dL, p = 0.004), and LDL-cholesterol (118 ± 32 mg/dL vs. 110 ± 27 mg/dL, p = 0.03) were higher in female patients compared to male patients. The FI ratio (55 ± 15% vs. 60 ± 15%, p = 0.02) and FF ratio (9 ± 8% vs. 12 ± 10%, p = 0.02) were lower, but the DC ratio (12 ± 13% vs. 9 ± 11%, p = 0.01) and NC ratio (23 ± 11% vs. 19 ± 12%, p = 0.02) were higher in female patients than in male patients. The differences in coronary risk factors between females and males may be associated with coronary plaque characteristics. Differences in culprit coronary plaque composition were observed between female and male patients with stable angina.