Determination of organic carbon in coastal marine particles with a CHN analyzer : effects of inorganic carbon

無機炭素を含む海洋中粒子の有機炭素・窒素をCHN元素分析計で定量する場合には，予め酸処理により無機炭素（PIC）を除去する必要があるが，沿岸域試料で，酸処理なしでのCHN分析計の測定値を有機炭素と見做して報告している例が稀に見られる。そこで，瀬戸内海で採取された懸濁粒子，沈降粒子，および堆積物を用いて，酸処理の有無が粒状有機炭素（POC）の分析結果に及ぼす影響と，そこから派生する問題について検討した。一部の懸濁粒子や，沈降粒子および海底堆積物中の炭素の測定値は，酸処理なしの値が酸処理ありの値よりも顕著に高く，C/chl. a，C/N比なども過大評価されることが確認された。以上のことから，瀬戸内海を含む沿岸域試料でも，分析前の酸処理が必須であることが明らかとなった。Organic carbon and nitrogen were generally determined with a CHN analyzer after removing carbonate by acidification of samples with liquid acid or HCl vapor. However, some workers have conducted the CHN measurements for coastal marine particles without the acidification and reported their analytical values as POC. Here, we compared the carbon values of the CHN measurements with or without acid treatment (HCl vapor) to suspended, settling particles and sediments in Seto Inland Sea. As a result, the carbon values of samples without acidification were significantly higher than those of untreated ones. Overall, our results indicate the acidification of samples is an indispensable procedure for determining POC in various marine particles

アマモの葉上着生群集の現存量および種組成の葉齢間における変動

沿岸生態系や物質循環において重要な役割を果たしていることが示唆されつつも，葉上着生群集の種の遷移や現存量の経時的な変化を調べた例は少ない。そこで，アマモ葉上に生育する着生群集を採取し，その現存量と種組成を葉ごとに調べ，葉齢間で比較した。その結果，現存量（クロロフィルα，粒状有機炭素・窒素）と細胞数は葉齢が高くなるほどに高密度であり，最も若い葉を基準にするとその差はPOCで最大21倍，細胞数で最大192倍であった。優占種はシアノバクテリアのLeptolyngbya sp.，珪藻類のCocconeis scutellum, Campylopyxis garkeana, Gomphonemataceaeなどであったが，葉齢と優占種の変化には統計的に有意な差は認められなかった。着生群集中のPOCは珪藻類の細胞数と有意な相関が認められたが，全細胞数との間では認められなかった。このことはシアノバクテリアのLeptolyngbya sp. は細胞数で優占したが，細胞体積が珪藻に比べて顕著に小さい（100～700分の1程度）ためにPOCの増加への寄与が小さいことが原因と考えられた。すなわち，葉上着生群集の中で，珪藻類が有機炭素で示される現存量の主体であることが示唆された。さらに，葉齢の高いものはPOC/DWが低く，無機物含量の多い浮泥等がより付着しやすい環境になっていたと考えられる。The development of the epiphytic community on the leaves of Zostera marina was followed by comparing variations in epiphytic organic carbon, chlorophyll a, cell abundance, and species composition between the younger and older leaves. Biomass of epiphytic community on Z. marina depended on leaf age; particulate organic carbon and cell abundance on the older leaves were 21 and 192 times higher than those on the youngest leaves, respectively. The abundant taxa of epiphytic community were Leptolyngbia sp. (Cyanobacteria), Cocconeis scutellum, Campylopyxis garkeana, and Gomphonemataceae (Bacillariophyceae), and the change of species composition of epiphytic community was independent on the leaf age. Significant relation between CHLa and POC showed organic matter on the leaves was consisted of algal cells. The amount of epiphytic POC was well correlated with diatom cell abundance (P<0.1), but not with total cell abundance. The prevalence of diatoms instead of Cyanobacteria on the leaves was shown by both chemical and taxonomic analyses.　Low POC/DW ratios of epiphytic community on the older leaves indicated that inorganic suspended particles were more likely to adhere

Summer distribution and short-term variation of the bottom turbid layer in Suo-sound in the Western Seto Inland Sea, Japan

2009年の6月29日-7月2日と8月22-23日に，周防灘において水温，塩分，クロロフィルα（以下chl. α），濁度の鉛直分布を調べた。6-7月にはchl. αの亜表層極大と海底高濁度層がほぼ調査海域全体に形成されていた。8月にはchl. α の亜表層極大は弱くなり，6-7月と較べて海底高濁度層の発達が顕著で，chl. α濃度の増加も見られた。6-7月と8月の両観測期間は，それぞれ小潮と大潮の時期に相当していたことから，潮汐周期が海底高濁度層の発達に影響を及ぼしている可能性が示唆された。また，両観測期間中に，灘西部の2観測点（水深10mの浅海域と30mの沖合域）において1-3時間毎の連続観測を行って日周変動を調べた。海底高濁度層は水温・塩分（および密度）の急激な変化時に最大値を示し，濁度層の分布パターン・厚さは潮汐周期と底層の水温･塩分･密度分布によく対応していた。さらに，塩分－chl. α，塩分－濁度，chl. α－濁度の関係から，粒状懸濁物を陸（河川）起源，海底高濁度層，亜表層クロロフィル極大，異水塊に由来するものに分別することができた。During June 28 to July 2 and August 22 to 23 in 2009, we investigated the distributiosn and diurnal variations of temperature, salinity, chlorophyll a (chl.α) and turbidity in Suo-sound, Seto Inland Sea. In June to July observation, the subsurface chl.α maximum layer (SCM) and the bottom turbid layer (BTL) were found throughout the Suo-sound. In August, the SCM almost diminished but the BTL significantly developed compared to June to July observations and chl.α also showed a noticeable increase in the bottom layer. June to July and August observations corresponded with a neap and spring tides, suggesting a close relation between the development of the BTL and the tidal cycle. The turbidity values of BTL showed a maximum when temperature and salinity changed rapidly, and the distribution pattern of the BTL well-corresponded to those of temperature and salinity, particularly in spring tide in August. Particulate matter was classified into four groups such as terrigeous matter, BTL, SCM, and different water mass according to salinity-chl.α, salinity-turbidity, and chl.α-turbidity relationships

Seasonal and spatial variations of optical properties, chlorophyll a and turbidity in Suo-Sound of the western Seto Inland Sea, Japan

2007年の5月から11月にかけて，ほぼ毎月，周防灘全域の全水柱（ここでは，海表面から海底直上20cmまで）における水温，塩分，光量子，クロロフィルα（以下Chl.α），濁度の鉛直分布及び透明度の海域分布を調査し，アサリ生産との関連性について検討した。その結果，海底高濁度層が灘全体に見られ，特に灘南西部の浅海域（水深10m程度）では，観測期間を通じて沖合域よりも濁度は高く，Chl.αも高濃度だった。これらの浅海域を含めて，灘西部の水深20m程度以浅の海域では，一般に海表面から海底までの全水柱が有光層になっていた。周防灘のアサリ漁場は，干潟から水深5m程度までの海域にあるため，底生濾過捕食者のアサリにとって，餌料供給の点では沖合域よりは好適条件を備えていると考えられた。また，Chl.α濃度は，鉛直混合の開始初期の10月に周防灘全体で最も高く，時期的にはアサリの秋季産卵の数週間前であると考えられた。これらのことから，周防灘のアサリ生産は，地域的・季節的な環境条件の違いとそれに伴う植物プランクトンの変動に関連があることが明らかとなった。From May to November 2007, we investigated the seasonal and spatial variations of temperature, salinity, optical properties, chlorophyll-α and turbidity in Suo-Sound of the Seto Inland Sea in relation to the Manila clam (Ruditapes philippinarum) production. The bottom turbid layer was found throughout the Suo-Sound, particularly in the western shallow area (bottom depth: about 10 m) which chlorophyll a concentrations were significantly higher than offshore. Generally, the entire water column of western area (bottom depth: less than 20 m) was mostly the euphotic zone. As the fishery grounds of the Manila clam located in the mud flat and the areas less than 5 m water depth, they inhabit in potentially productive area of phytoplankton and benthic microalgae. Also, the highest chlorophyll-α concentrations were observed in October, approximately a few weeks before their autumn spawning period. These results indicate that the marina clam's production is apparently coupled with local environmental factors and seasonal events related to the phytoplankton production.本研究は，広島大学と水産総合センター瀬戸内海区水産研究所との共同研究「瀬戸内海におけるベントスの生産性評価手法の開発」の一環として行われ，「広島大学地域貢献研究」および「水産基盤整備調査委託事業：広域アサリ漁場整備開発のための海況調査」の予算支援を受けたものである

Comparison of absorption coefficients between accumulated matter on the thalli of Ecklonia kurome and suspended matter in the water surrounding Ecklonia bed

海水中の懸濁物と，海藻の葉上堆積物は，ともに藻体表面に到達する光を質的かつ量的に変化させ，海藻の生産力に多大な影響を及ぼす。本研究では内湾域である広島湾における大型褐藻クロメの葉上堆積物とクロメ群落直近の海水中の懸濁物について，両者の光吸収係数を統一的手法（QFT法）に基づいて把握し，その特性を比較した。懸濁物と堆積物の全体の光吸収特性に明瞭な差は認められず，葉上堆積物の多くが沈降した懸濁物によって構成されていたことが推察された。懸濁物・堆積物ともに，デトリタスや微細藻類など多様な要素により構成されており，光合成有効波長域（400-700nm）のうち，短波長側の光は微細藻類の色素以外のデトリタスなどが，長波長側の光は微細藻類の光合成色素が吸収し，それぞれクロメの光吸収に大きく影響すると考えられた。Light is the primary limiting factor for macroalgal production. Understanding not only the quantity but also the quality of light reaching algal thalli is important to the success of algal recovery and sustainability. This study explores the optical properties of accumulated matter on the thalli of Ecklonia kurome and suspended matter in the water surrounding an Ecklonia bed in Hiroshima Bay, based on spectral absorption coefficient estimated by the quantitative filter technique (QFT) method. According to the experiments, minimal difference of optical properties between suspended matter and accumulated matter was recognized. It is assumed that suspended matter in the water formed the accumulated matter on the thalli of E. kurome. Both suspended matter and accumulated matter were composed of multiple components, various kinds of microalgae, detritus and inorganic matter. In the wavelength-specific photosynthetically active radiation (400-700nm), detritus and inorganic matter formed the primary absorber of blue light, while microalgal pigments was the primary absorber of red light. Each absorber in suspended and accumulated matter might attenuate specific wavelength and change the quality of light reaching the thalli of E. kurome

Accumulation of Ulva spp. (Chlorophyta) and other seaweed thalli on the shallow sea bottom of Hiroshima Bay (A preliminary survey)

広島湾奥部の大野瀬戸周辺の砂泥海底域で，小型底曳き網（ナマコ桁網）と潜水により，アオサ類等をはじめとする海藻類の堆積状況を調査した。38種の海藻・海草類が採集されたが，現存量では底曳き網による採集物の64～100％をアオサ類が占めていた。アオサ類は水深5m以浅で最も多く採集され，砂浜・干潟に連続する海底勾配の緩やかな浅海底がアオサ類の増殖帯になっていると考えられた。Biomass of Ulva spp. (Chlorophyta) causing ‘green tide’ and other seaweeds accumulated on shallow sea bottom in inner area of Hiroshima Bay was estimated by trawl-net and SCUBA surveys. Thirty-eight species of seaweed and seagrass was sampled, but Ulva spp. was dominant occupying 64-100 % in biomass of all samples. Ulva spp. was sampled most abundantly at the stations shallower than 5 m, and it was indicated that sea bottom with a gentle slope, and located offshore of sandy beaches or tidal-flats offers a suitable condition for Ulva growth

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362