The Distribution and Migration of 137Cs in Oak (Quercus serrata) and Cedar (Cryptomeria japonica) Forest Organic Fractions

To analyse the 137Cs distribution and migration under various fractions of organic matter layers, this study investigated easily recognizable, originally shaped organic L-fractions, and not easily recognizable, early fermented and fragmented organic F-fractions, of both oak (Quercus serrata) and cedar (Cryptomeria japonica) sampled from Osawa watershed sites at Nihonmatsu City, Fukushima Prefecture, Japan. The organic materials were put on top of soil columns from Field Museum (FM) Tamakyuryo in Hachioji City, Tokyo. The 137Cs vertical distribution in forest soil profiles was analyzed using the relaxation mass depth, ho (kg m−2). Soil columns with both L and F- organic layer fractions of both oak and cedar, labelled as Oak-L, Oak-F, Cedar-L and Cedar-F with four replications (n = 16), were set up by the laboratory column-based method and kept under five months’ incubation period. Soil columns after incubation were sampled at depths of 0–1 cm, 1–2 cm, 2–5 cm and 5–10 cm. Results of 137Cs inventory in the organic fractions showed that 86% (oak and cedar) of the total organic layer fractions 137Cs inventory accumulated within the F-layer, indicating that the transformation of litter is a huge source for potentially mobile 137Cs, especially the oak F-layer (67% 137Cs inventory) and further continuous transfer into the forest soil mineral layers. A higher ho in L treated soils (Oak-L and Cedar-L) compared to the F treatments implied that the low 137Cs amounts penetrated faster and deeper due to their water-soluble nature. Furthermore, Cedar-F showed a higher ho of 24.3 kg m−2 than Oak-F of ho, 14.0 kg m−2, and a significant positive relationship between 137Cs retention and total carbon (TC) (p < 0.05) suggested the influence of soil organic matter on 137Cs penetration and retention. The C/N (carbon nitrogen ratio) results revealed that organic matter fractions of high C/N including 137Cs, as observed in Cedar-F, in which decomposition does not advance, penetrates soil depths while the organic matter fraction of low C/N, observed in Oak-F, showed that decomposition advanced to release 137Cs which was held by adsorption unto the RIP (radiocesium interception potential) of soil surface. In addition, infiltration by water as a transportation process was suggested to largely influence the downward migration and retention of 137Cs at lower depths of Cedar-F.Japan Society for the Promotion of SciencePeer Reviewe

Webサイトにおけるユーザビリティテスト事例(フレキシブル・ラーニングのための学習支援と評価(I),メディアFDとフレキシブル・ラーニング支援の研究開発)

本稿ではWebサイトのユーザビリティ向上に向け、株式会社富士通ラーニングメディアのサービスサイトを対象に実施したヒューリスティック評価ならびにユーザビリティテスト結果と、改善したWebサイトにおけるユーザビリティ改善効果について報告する

Conversion to complete resection with mFOLFOX6 with bevacizumab or cetuximab based on K‐RAS status for unresectable colorectal liver metastasis (BECK study): Long‐term results of survival

[Background/Purpose]To investigate the long‐term outcome and entire treatment course of patients with technically unresectable CRLM who underwent conversion hepatectomy and to examine factors associated with conversion to hepatectomy. [Methods]Recurrence and survival data with long‐term follow‐up were analyzed in the cohort of a multi‐institutional phase II trial for technically unresectable colorectal liver metastases (the BECK study). [Results]A total of 22/12 patients with K‐RAS wild‐type/mutant tumors were treated with mFOLFOX6 + cetuximab/bevacizumab. The conversion R0/1 hepatectomy rate was significantly higher in left‐sided primary tumors than in right‐sided tumors (75.0% vs 30.0%, P = .022). The median follow‐up was 72.6 months. The 5‐year overall survival (OS) rate in the entire cohort was 48.1%. In patients who underwent R0/1 hepatectomy (n = 21), the 5‐year RFS rate and OS rate were 19.1% and 66.3%, respectively. At the final follow‐up, seven patients had no evidence of disease, five were alive with disease, and 20 had died from their original cancer. All 16 patients who achieved 5‐year survival underwent conversion hepatectomy, and 11 of them underwent further resection for other recurrences (median: 2, range: 1‐4). [Conclusions]Conversion hepatectomy achieved a similar long‐term survival to the results of previous studies in initially resectable patients, although many of them experienced several post‐hepatectomy recurrences. Left‐sided primary was found to be the predictor for conversion hepatectomy

第5章 eラーニングにおけるメンタリングメールの学習効果について(第I部 平成14年度、15年度の研究課題,フレキシブル・ラーニングのための学習支援と評価(II),メディアFDとフレキシブル・ラーニング支援の研究開発)

一般的にeラーニングにおけるメンタリングとして、企業内教育においては特定条件の学習者に対して定型メールを送信する方法が多く用いられている。今回、モチベーションの持続と学習目標の理解達成度に対してより効果のあるメンタリング方法を模索するため、複数グループの学習者に対して、それぞれ異なるメンタリング方法を適用し、その差異を比較調査した。結果、学習者の進捗状況に応じてパーソナライズされたメンタリング方法がもっとも高い学習効果が見られた

Differences in Characteristics of Photosynthesis and Nitrogen Utilization in Leaves of the Black Locust (Robinia pseudoacacia L.) According to Leaf Position

Robinia pseudoacacia L. has been widely planted worldwide for a variety of purposes, but it is a nonindigenous species currently invading the central part of Japanese river terraces. To understand and control this invasion, we investigated how this species invests nitrogen resources in different functions depending on the leaf location, and how these resources are used in physiological reactions such as photosynthesis. The Tama river terrace was examined in Tokyo, Japan. The leaf nitrogen (N) concentration, chlorophyll (Chl) concentration, Chl a/b ratio, leaf mass per unit area (LMA) and ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCo) concentration were all significantly lower in shade leaves than in leaves exposed to the sun. Conversely, the net photosynthetic rate in saturated light conditions (Pmax), the net photosynthetic rate under enhanced CO2 concentration and light saturation (Amax), the maximum carboxylation rate of RuBisCo (Vcmax) and the maximum rate of electron transport driving RUBP regeneration (Jmax) were all significantly lower in shade leaves than in leaves exposed to the sun. We also found that RuBisCo/N and Chl/N were significantly less in shade leaves, and values of Jmax/N, Vcmax/N less in shade leaves than in sun leaves, but not significantly. Allocation of nitrogen in leaves to photosynthetic proteins, RuBisCo (NR) was broadly less in shade leaves, and NL (light-harvesting complex: LHC, photosystem I and II: PSI and PSII) and NE (electron transport) were also lower. The N remaining was much greater in shade leaves than in sun leaves. We suggest that N remobilization from RuBisCo is more efficient than remobilization from proteins of NE, and from NL. This study shows that R. pseudoacacia has an enhanced ability to adapt to environmental changes via characteristic changes in N allocation trade-offs and physiological traits in its sun and shade leaves.Forestry, Faculty ofNon UBCReviewedFacult

Regional Comparison of Nitrogen Export to Japanese Forest Streams

Nitrogen (N) emissions in Asian countries are predicted to increase over the next several decades. An understanding of the mechanisms that control temporal and spatial fluctuation of N export to forest streams is important not only to quantify critical loads of N, N saturation status, and soil acidification N dynamics and budgets in Japanese forested watersheds is not clear due to the lack of regional comparative studies on stream N chemistry. To address the lack of comparative studies, we measured inorganic N (nitrate and ammonium) concentrations from June 2000 to May 2001 in streams in 18 experimental forests located throughout the Japanese archipelago and belonging to the Japanese Union of University Forests. N concentrations in stream water during base flow and high flow periods were monitored, and N mineralization potential in soil was measured using batch incubation experiments. Higher nitrate concentrations in stream water were present in central Japan, an area that receives high rates of atmospheric N deposition. In northern Japan, snowmelt resulted in increased nitrate concentrations in stream water. The potential net N mineralization rate was higher in surface soil than in subsurface soil, and the high potential for N mineralization in the surface soil partly contributed to the increase in nitrate concentration in stream water during a storm event. Regional differences in the atmospheric N deposition and seasonality of precipitation and high discharge are principal controls on the concentrations and variations of nitrates in stream water in forested watersheds of Japan

Postoperative Complications following Open Reduction and Rigid Internal Fixation of Mandibular Condylar Fracture Using the High Perimandibular Approach

The high perimandibular approach is a feasible surgical technique for treating mandibular condylar fractures with open reduction and internal fixation, followed by fewer complications. Temporary trismus is the only postoperative complication that may occur. This study evaluated postoperative complications following open reduction and rigid internal fixation (OR-IF) of mandibular condylar fractures using the high perimandibular approach. Twenty consecutive patients undergoing OR-IF were included in this study. They included 11 male and 9 female patients, of an average age of 58.5 years, all of whom responded to a follow-up call at least 12 months after the surgery. All patients were evaluated for range of mouth opening, postoperative complications, and radiological findings. A statistical analysis of the relationship between range of mouth opening and related clinical parameters at 6 months postoperative evaluation was conducted. The fracture of the condylar neck was associated with a limited range of mouth opening and longer operation time. However, longer operation time was not associated with a limited range of mouth opening. The high perimandibular approach with OR-IF in mandibular condylar fractures is a feasible and safe technique; however, prolonged surgery and mandibular condylar neck fractures could affect the postoperative range of mouth opening