Democracy under uncertainty: The ‘wisdom of crowds’ and the free-rider problem in group decision making

We introduce a game theory model of individual decisions to cooperate by contributing personal resources to group decisions versus by free-riding on the contributions of other members. In contrast to most public-goods games that assume group returns are linear in individual contributions, the present model assumes decreasing marginal group production as a function of aggregate individual contributions. This diminishing marginal returns assumption is more realistic and generates starkly different predictions compared to the linear model. One important implication is that, under most conditions, there exist equilibria where some, but not all members of a group contribute, even with completely self-interested motives. An agent-based simulation confirms the individual and group advantages of the equilibria in which behavioral asymmetry emerges from a game structure that is a priori perfectly symmetric for all agents (all agents have the same payoff function and action space, but take different actions in equilibria). And a behavioral experiment demonstrates that cooperators and free-riders coexist in a stable manner in groups performing with the non-linear production function. A collateral result demonstrates that, compared to a ―dictatorial‖ decision scheme guided by the best member in a group, the majority-plurality decision rules can pool information effectively and produce greater individual net welfare at equilibrium, even if free-riding is not sanctioned. This is an original proof that cooperation in ad hoc decision-making groups can be understood in terms of self-interested motivations and that, despite the free-rider problem, majority-plurality decision rules can function robustly as simple, efficient social decision heuristics.group decision making under uncertainty, free-rider problem, majority-plurality rules, marginally-diminishing group returns, evolutionary games, behavioral experiment

在阪朝鮮人の定住化と生活に関する史的研究 一九一〇年から一九四五年、日本人との関係を中心にして [全文の要約]

関西大

Adult T cell Leukemia-Lymphoma

Adult T-cell leukemialymphoma (ATL) was first described in 1977 as a distinct clinico-pathological entity with a suspected viral etiology. Subsequently, a novel RNA retrovirus, human T-cell leukemia/lymphotropic virus type 1 (HTLV-1) was isolated from a cell line established from the leukemic cells of an ATL patient, and the finding of a clear association with ATL led to its inclusion among human carcinogenic pathogens. The three major routes of HTLV-1 transmission are mother-to-child infections via breast milk, sexual intercourse, and blood transfusions. HTLV-1 infection early in life, presumably from breast feeding, is crucial in the development of ATL. The diversity in clinical features and prognosis of patients with this disease has led to its subtype-classification into four categories, acute, lymphoma, chronic, and smoldering types defined by organ involvement, and LDH and calcium values. In cases of acute, lymphoma, or unfavorable chronic subtypes (aggressive ATL), intensive chemotherapy such as VCAP-AMP-VECP is usually recommended. In cases of favorable chronic or smoldering ATL (indolent ATL), watchful waiting until disease progression has been recommended although the long term prognosis was inferior to those of, for instance, chronic lymphoid leukemia. Retrospective analysis suggested that the combination of interferon alpha and zidovudine was apparently promising for the treatment of ATL, especially for types with leukemic manifestation. Allogeneic hematopoietic stem cell transplantation is also promising for the treatment of aggressive ATL possibly reflecting graft vs. ATL effect. Several new agent-trials for ATL are ongoing and in preparation, including a defucosylated humanized anti-CC chemokine receptor 4 monoclonal antibody. Two steps should be considered for the prevention of HTLV-1-associated ATL. The first is the prevention of HTLV-1 infections and the second is the prevention of ATL among HTLV-1 carriers. So far, no agent has been found to be effective for the latter. Further investigation on the pathogenesis of ATL is crucial for the prevention and treatment of this refractory leukemialymphoma

布団とベット上における介護初心者と介護熟練者のおむつ交換時の腰部負担の差異

Objectives : To clarify the difference in low back load between novice and skilled caregivers in diaper changing on a futon and a bed. Methods : Agonist trunk and lower-limb muscle activity during diaper changing in 26 novice and 21 skilled caregivers was examined using a surface electromyograph attached to 8 agonist muscles, including the left and right lumbar erector spinae, rectus abdominis, vastus lateralis, and semitendinosus. 　The low back loads during diaper changes on the futon and bed were measured. 　The maximum voluntary contractions of the 8 muscles were normalized (%MVC) to compare their mean integrals between the novice and skilled caregivers on the futon and bed, and analyzed using t-tests, paired t-tests, and two-way analysis of variance. Using MyoResearch XP Software, diaper changing measurements were simultaneously videotaped to perform real-time analysis of movements and muscle activity. Results : For care time, novices took significantly longer to perform a diaper change on the futon and bed compared with skilled caregivers. The bilateral erector spinae in the novice caregivers was significantly greater on the bed than on the futon, but there was no significant difference in the rectus abdominis. In skilled caregivers, there was no significant difference in erector spinae and the rectus abdominis between the futon and bed. On the futon, no significant differences were observed in the left and right erector spinae and rectus abdominis between the novice and skilled caregivers. On the bed, the right erector spinae was significantly greater in novice compared with the skilled caregivers. For the bilateral vastus lateralis and semitendinosus, muscle activity in novice caregivers was significantly greater compared with skilled caregivers on the futon and bed. Skilled caregivers tended to maintain their posture by standing with their femora supported by the bed mattress throughout care activity on the bed. Discussion : It may be necessary for novice caregivers to acquire higher-level skills, such as creating a supporting point on the bed throughout caring activity. This will allow care activities to be performed efficiently with a reduced lumber load, while making full use of the convenience of beds and the lower height difference from caregiver to receiver.【目的】布団上とベッド上において、介護の初心者と熟練者間のおむつ交換時の介護動作 と腰部負荷の違いを明らかにする。 【方法】介護の初心者26名と熟練者21名を対象とし、表面筋電計を用いて布団上と在宅介 護ベッド上でのおむつ交換時の左右の体幹及び下肢の主動作筋活量 (腰部脊柱起立筋、腹 直筋、外側広筋、半腱様筋) を計測した。各筋の%MVC (Maximum voluntary contraction) の積分値を算出し、t 検定、対応のある t 検定、2 元配置分散分析を用いて、布団上とベッ ド上の初心者と熟練者を比較した。MyoResearch XP Softwareを用いて、筋活量と介護動 作をリアルタイムに画像分析した。 【結果】介護時間は、布団上とベッド上で、初心者の方が熟練者よりも有意に長かった。初 心者では、両側の脊柱起立筋はベッド上の方が布団上よりも有意に高かったが、腹直筋に は違いがなかった。熟練者では、脊柱起立筋と腹直筋と布団上とベッド上では違いがな かった。布団上では、左右の脊柱起立筋と腹直筋は、初心者と熟練者では違いがなかった。 ベッド上では、右の脊柱起立筋は初心者の方が熟練者よりも有意に高かった。両側の外側 広筋と半腱様筋は、布団上とベッド上で、初心者の方が有意に高かった。熟練者は、ベッ ド上での介護時は常に大腿部でマットレスに支点を作っておむつ交換をしていた。 【考察】布団上では、介護初心者は習得した介護を実践しやすかったと示唆される。ベッ ド上での介護時は、ベッドの利便性と要介護者との高低差が少ないことを活用して、常に ベッドに支点を作って介護する技術の習得が必要である。Thesis of Kyota Kaoru / 京田 薫 博士論文 金沢大学医薬保健学総合研究科（保健学専攻

Phosphorus behavior in sediments during a sub-seabed CO\u3csub\u3e2\u3c/sub\u3e controlled release experiment

© 2015 Elsevier Ltd. The CO2 controlled release experiment Quantifying and Monitoring Potential Ecosystem Impacts of Geological Carbon Storage (QICS) assessed the impacts of potential CO2 leakage from sub-seabed carbon capture and storage reservoirs to the marine environment. During QICS, CO2 gas was released into shallow sediment in Ardmucknish Bay, Scotland, in the spring and summer of 2012. As part of this project, we investigated the effects of CO2 leakage on sedimentary phosphorus (P), an essential nutrient for marine productivity. We found no statistically significant effects during QICS, as the solid-phase P content in the sediment was constant before, during, and after exposure to CO2. However, laboratory experiments using marine sediment standard materials as well as QICS sediment revealed substantial differences among these different sediment types in their potential for P release during CO2 exposure. Employing the SEDEX sequential extraction technique to determine the sizes of the major P pools in the sediments, we showed that calcium-bound P can be easily released by CO2 exposure, whereas iron-bound P is a major sink of released P. The overall impacts of CO2 leakage on sediment P behavior appear to be low compared to natural variability

介護老人保健施設における排便ケアシステムの構築を目指した介入

This study was conducted to evaluate the construction of a system for defecation care in long-term care health facilities. Two intervention programs were undertaken, one each for Facility A and Facility B. In both Programs A and B, fecal assessment using the Bristol Stool Scale (BSS) was introduced, and a defecation care leadership development workshop helped staff members to develop a defecation care improvement plan. In Program B, researchers also performed in-house education for 6 months after the workshop to support the defecation care improvement plan. The results were evaluated 1 year after the initiation of the programs. The feces changed from soft or hard to normal in 29.5% of residents in Facility A (Program A) and in 48.3% of residents in Facility B (Program B). The level of resident satisfaction increased significantly in both facilities. There was a significant increase in the number of residents not receiving stimulant cathartics, and the total amount of cathartics used decreased significantly in both facilities. In Program B, all the defecation care improvement plan goals were achieved, and there was a high rate of implementation of defecation assessment by staff. In Program A, some of the defecation care improvement plan goals were not achieved. It is suggested that the promotion of workshops for training defecation care leaders would improve the quality of defecation care. We also confirmed the efficacy of in-house training following the workshops, for the construction of a system for defecation care. 本研究の目的は、施設における排便ケアシステムの構築を目指した介入を行い、その効果を評価することである。施設内において排便ケアシステムを構築するため、２つのプログラムを作成した。２つのプログラムは、Ａ施設またはＢ施設のそれぞれで実施した。プログラムＡは、The Bristol Stool Scaleを用いて便の性状をアセスメントして便通コントロールをする能力、および排便ケアリーダーが排便ケア改善計画を立案して実施し、評価する能力の育成のため、６ケ月間の研修会を実施した。プログラムＢは、研修会後も引き続き６ケ月間、施設内における排便ケア改善計画の実施を支援するための組織内教育を加えた。Ａ施設はプログラムＡ、Ｂ施設はプログラムＢの対象とした。２つのプログラムの効果は１年後に評価した。入所者の便の性状は２つのプログラムとも１年後に有意に変化しており、軟便または硬便から普通便に改善した者の割合は、プログラムAが２９.５％、プログラムBが４８.３％だった。入所者の満足度は２つのプログラムとも有意に高くなった。２つのプログラムとも刺激性下剤を使用しない者の割合は有意に増加しており、施設全体の緩下剤の使用量は有意に減少した。プログラムＢは、以上の成果に加えて、スタッフの排便アセスメントの実施度は有意に高くなり、排便ケア改善計画の目標のすべてを達成した。しかし、Ａ施設では目標の一部が達成できなかった。以上の結果より、研修会により、スタッフの便の性状のコントロール能力の向上の効果が示唆された。さらに研修会後に組織内教育を行なうことで、施設内の排便ケアのシステムの構築における有効性が示唆された。Thesis of Sakakibara, Chiaki / 榊原 千秋 博士学位論文(金沢大学 / 大学院医薬保健学総合研究科

Characteristic expression of HTLV-1 basic zipper factor (HBZ) transcripts in HTLV-1 provirus-positive cells

<p>Abstract</p> <p>Background</p> <p>HTLV-1 causes adult T-cell leukemia (ATL). Although there have been many studies on the oncogenesis of the viral protein Tax, the precise oncogenic mechanism remains to be elucidated. Recently, a new viral factor, HTLV-1 basic Zip factor (HBZ), encoded from the minus strand mRNA was discovered and the current models of Tax-centered ATL cell pathogenesis are in conflict with this discovery. HBZs consisting of non-spliced and spliced isoforms (HBZ-SI) are thought to be implicated in viral replication and T-cell proliferation but there is little evidence on the HBZ expression profile on a large scale.</p> <p>Results</p> <p>To investigate the role of HBZ-SI in HTLV-1 provirus-positive cells, the HBZ-SI and Tax mRNA loads in samples with a mixture of infected and non-infected cells were measured and then adjusted by dividing by the HTLV-I proviral load. We show here that the HBZ-SI mRNA level is 4-fold higher than non-spliced HBZ and is expressed by almost all cells harboring HTLV-1 provirus with variable intensity. The proviral-adjusted HBZ-SI and Tax quantification revealed a characteristic imbalanced expression feature of high HBZ and low Tax expression levels in primary ATL cells or high HBZ and very high Tax levels in HTLV-1-related cell lines (cell lines) compared with a standard expression profile of low HBZ and low Tax in infected cells. Interestingly, according to the mutual Tax and HBZ expression status, HTLV-1-related cell lines were subcategorized into two groups, an ATL cell type with high HBZ and low Tax levels and another type with high Tax and either high or low HBZ, which was closely related to its cell origin.</p> <p>Conclusion</p> <p>This is the first comprehensive study to evaluate the mutual expression profile of HBZ and Tax in provirus-positive cells, revealing that there are quantitative and relative characteristic features among infected cells, primary ATL cells, and cell lines.</p

骨破壊性T細胞による口腔細菌感染制御

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 畠山 昌則, 東京大学教授 清野 宏, 東京大学特任准教授 柳井 秀元, 東京大学教授 藤尾 圭志, 東京大学教授 田中 栄University of Tokyo(東京大学

Game Theory and Thin Spread of Japanese Banks

本稿は、銀行の貸出金利設定行動を、ゲームの理論を応用したモデルを用いてシミュレーションしたものである。銀行にドライ型(米銀をイメージし、個々の取引からの利益を重視する銀行とした)とウエット型(邦銀をイメージし、長期的な対顧客取引を重視する銀行とした)があるとする。ドライ型は当期の利益の最大化を目指すものとする。ウエット型は、景気局面による借り手の信用コストの変動を金利設定に反映させないものとし、当期の利益に加えて顧客数の増加も目標の一つとして金利設定を行なうものとした。銀行数は二行とし、互いに相手の行動パターンを知った上で相手の出方を予測しながら自らの金利設定を行なうとして、シミュレーションを行なった。結果の第一は、二行ともドライ型である場合(米国市場を想定)と二行ともウエット型である場合(日本市場を想定)では、後者の方が金利が低く銀行の利益が小さくなる可能性があるというもので、邦銀の行動パターンが低利鞘の一因である可能性を示唆している。結果の第二は、ドライ型とウエット型が共存する場合には、ウエット型の方が低い金利を提示し、結果として高い利益を上げるというものである。ウエット型が主である日本市場においては、ある銀行がドライ型への転換を決意しても成功せず、ウエット型中心の構造が持続するというメカニズムが示唆される。なお、共存モデルにおいてウエット型の方が利益が大きいということは、ドライ型の方が合理的で優れているとは限らないことを示唆しており、興味深い

Can Soft Budget Constraints Be Rational?

銀行が合理的に行動したとしても、「実質債務超過でありながらリストラを怠っている借り手に対して追い貸しを行なう」ことはあり得るし、それが国民経済的に望ましい場合もある。したがって、「追い貸しだから問題だ」とは言えない。たとえば建設中のビルを完成させるための資金を追い貸しすることは、銀行の回収額を増加させるのみならず、生産的で国民経済的にも意義のあるプロジェクトである。また、債務超過であっても借り手が自力で利払いを行なっていれば、これに対する追い貸しも、銀行にとり合理的で国民経済的にも意味がある。「銀行が利払い資金を追い貸しして借り手を延命させ、自己資本の毀損を防いでBIS規制の制約を逃れる」という行為も、銀行にとっては場合により合理的な行為であり得るし、国民経済的にも有害とは言い切れない。マクロ的な資金配分への悪影響が限定的である一方で、貸し渋りを緩和する効果も期待でき、しかも景気が回復するとこうした追い貸しが縮小されていくメカニズムが内包されているからである。銀行がBIS規制逃れの目的で追い貸しを行なう場合には、モデル上は、「借り手の資産が少ないほど追い貸しを受けやすい」という逆転現象が生じ得る。もっとも、90年代の邦銀の状況に鑑みれば、そうした実例は多くなかったと思われる。銀行が追い貸しを行なうことが予想されると借り手がリストラを怠るという問題があるため、銀行としては「リストラしないと清算する」と脅す必要がある