The concentrations of dissolved Fe ([DFe]), total dissolvable Fe, humic‐type fluorescence intensity (humic F intensity) as humic‐type fluorescent dissolved organic matter (humic‐type FDOM), and nutrients were determined vertically in the northern Bering Sea shelf (Yukon River estuary region and St. Lawrence Island polynya region), the eastern Chukchi Sea shelf (Chukchi shelf polynya region), and the central Bering Strait during 30 July to 12 August 2007 and 30 June to 12 July 2008. In early July 2008, with a nearly peak river water discharge period, remarkably high humic F intensity and high [DFe] were found with a decrease in salinity (S = 26–30) in the surface water of the Yukon River estuarine region. These results suggest that riverine humic‐type FDOM is responsible for [DFe] in coastal waters, with natural organic ligand complexation of Fe(III) apparently playing an important role in iron transport to the northern Bering Sea shelf. In the St. Lawrence Island and Chukchi shelf polynya regions, cold dense waters (T = −1.5 to −1.7°C and σθ = 26.2 to 26.7) were found in deep and bottom waters. The cold waters are characterized by high nutrient and iron concentrations and high humic F intensity, probably resulting from two main processes: brine rejection during sea ice formation and transport across the sediment‐water interface during early diagenesis. In the central Bering Strait, the waters are vertically uniform with high salinity (S ≥ 32.5) and high nutrient and iron concentrations. These waters appear to originate from the outer shelf of the Bering Sea and are not affected by denitrification occurring in bottom sediments of the Bering shelf.
We measured water-column iron concentrations from west to east along 47 degrees N in the subarctic North Pacific, and in the Bering Sea. In the North Pacific dissolved Fe (D-Fe) showed surface depletion, mid-depth maxima at 1000-1500 m (west, 1.3-1.6 nM; east, 0.9-1.1 nM), and a gradual decrease with depth below 3500-4000 m depth (west, 1.1-1.4 nM; east, 0.6-0.7 nM). D-Fe and total soluble Fe (T-Fe) in deep water showed a decreasing trend eastward. The higher iron concentrations in western deep waters probably result from higher inputs of dissolved Fe through atmospheric deposition or lateral transport. In contrast, D-Fe throughout the Bering Sea showed a consistent depth regime characterized by a rapid increase with depth to mid-depths, a gradual increase with depth in intermediate water to a maximum of 1.6-1.7 nM at 1500-2250 m, and a gradual decrease with depth to 1.3-1.4 nM at 3700 m. Higher iron concentrations and deeper D-Fe maxima in the Bering Sea are likely due to higher biological productivity and greater and deeper D-Fe input from the decomposition of sinking particulate organic matter in deep water. We suggest that the higher concentrations and deeper input of D-Fe as well as PO4 and humic-type fluorescent dissolved organic matter in the Bering Sea probably results from the longer time for the accumulation of decomposition products resulting from iron supply from the organic-rich downslope sediment along the steep continental slopes and slow replacement of the deep water in the Bering Sea Basin
12As a basis for analyzing development of six large grazing copepods (Eucalanus bungii,
Henoch -Schönlein purpura (HSP) is characterized by IgA-dominant deposition of immune complexes in the walls of small vessels, and is the most common cause of non-thrombocytopenic purpura in children. 1 Acute abdominal pain that is often colicky in nature is one of the most frequent symptoms in HSP. Although systemic corticosteroid therapy is often associated with dramatic improvement in relieving abdominal pain, it is inconclusive whether this treatment can prevent such serious intra-abdominal complications as spontaneous bowel perforations. 2 We describe a child with HSP who required repeated emergency laparotomy for intussusception and for ileal perforation that occurred consecutively during the course of corticosteroid therapy. Case reportA previously healthy 5-year-old boy presented with a 3 day history of joint pains and palpable purpura on both legs. He was diagnosed as having HSP based on a typical purpuric rash without thrombocytopenia (platelet count 348 000/mm 3 ; normal, 16 8000 -341 000/mm 3 ) on day 2. He was admitted because of intermittent abdominal pain on day 4. Routine blood and urine tests showed no abnormal fi ndings except slightly decreased activity of coagulation Factor X III (36.0%; normal, 70 -134%) in the plasma. Throat culture yielded Streptococcus pyogenes . He was placed on i.v. prednisolone (2 mg/kg per day) and ampicillin (100 mg/kg per day, for 5 days). Abdominal pain resolved quickly within 24 h after starting therapy. Purpura on the legs and arthralgias fl uctuated over several days despite treatment. On day 9 he complained of abrupt-onset colicky abdominal pain and emesis. The diagnosis of ileocolic intussusception was made on fl uoroscopy with contrast enema as well as on abdominal ultrasonography, which demonstrated the target sign. After failure to treat the condition by hydrostatic methods, an emergency laparotomy was performed. During surgery a segment of ileum measuring 15 cm in length, from the proximal to the ileocecal valve, showed intussusception. The intussusception was manually reduced. The color of the intestine was dark reddish, suggestive of slight ischemic change. There was no evidence of necrosis or perforation of the rest of the bowel. Appendectomy was also performed because the appendix was adherent to the mesentery. On the fi rst postoperative day famotidine and dried human coagulation factor X III concentrate (50 U/kg per day, i.v., for 3 days) were added to the aforementioned regimen.Although the purpuric rash persisted, the postoperative course was uneventful until day 16, when he again developed intermittent abdominal pain. On the following day he became febrile with a temperature of up to 38.4°C, and his abdomen was distended with diffuse tenderness, rebound, and guarding. Abdominal X-ray in a standing position showed subphrenic free air. Ultrasound indicated ascites uprising predominantly in the right lower quadrant and the Douglas pouch. Subsequent CT scan confi rmed the ultrasound fi ndings, and suggested acute panperitonitis. An emergency laparotomy...
11Short-term changes in vertical distributions of copepods during the spring 12 phytoplankton bloom were analyzed based on day and night vertically stratified 13 sampling (9 strata between 0-1000 m) with a fine-mesh (60 µm
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