Envelopes and clutters

AbstractIn this paper, a set function ϕ defined on a finite set Ω is said to be an upper envelope if there exists a set {pi} of nonnegative vectors on Ω such that ϕ(G)=max{p1(G),…,pn(G)} for all G⊂Ω. All upper envelopes form a convex cone. We give a necessary and sufficient condition for an upper envelope to be extremal in the cone of all upper envelopes in terms of its representation. Furthermore we study the upper envelopes represented by clutters. We show that a clutter is extremal in the cone of the upper envelopes if and only if it satisfies some kind of connectivity

Deep tree-ensembles for multi-output prediction

Recently, deep neural networks have expanded the state-of-art in various scientific fields and provided solutions to long standing problems across multiple application domains. Nevertheless, they also suffer from weaknesses since their optimal performance depends on massive amounts of training data and the tuning of an extended number of parameters. As a countermeasure, some deep-forest methods have been recently proposed, as efficient and low-scale solutions. Despite that, these approaches simply employ label classification probabilities as induced features and primarily focus on traditional classification and regression tasks, leaving multi-output prediction under-explored. Moreover, recent work has demonstrated that tree-embeddings are highly representative, especially in structured output prediction. In this direction, we propose a novel deep tree-ensemble (DTE) model, where every layer enriches the original feature set with a representation learning component based on tree-embeddings. In this paper, we specifically focus on two structured output prediction tasks, namely multi-label classification and multi-target regression. We conducted experiments using multiple benchmark datasets and the obtained results confirm that our method provides superior results to state-of-the-art methods in both tasks

The electric field changes and UHF radiations caused by the triggered lightning in Japan

In the rocket triggered lightning experiment of fiscal 1989, researchers observed electromagnetic field changes and UHF electromagnetic radiation accompanying rocket triggered lightning. It was found that no rapid changes corresponding to the return stroke of natural lightning were observed in the electric field changes accompanying rocket triggered lightning. However, continuous currents were present. In the case of rocket triggered lightning to the tower, electromagnetic field changes corresponding to the initiation of triggered lightning showed a bipolar pulse of a relatively large amplitude. In contrast, the rocket triggered lightning to the ground did not have such a bipolar pulse. The UHF radiation accompanying the rocket triggered lightning preceded the waveform portions corresponding to the first changes in electromagnetic fields. The number of isolated pulses in the UHF radiation showed a correlation with the time duration from rocket launching up to triggered lightning. The time interval between consecutive isolated pulses tended to get shorter with the passage of time, just like the stepped leaders of natural lightning

骨形成細胞シートは血管柄付き人工骨内での骨形成および血管形成を促進させる

BACKGROUND: The regeneration of large, poorly vascularized bone defects remains a significant challenge. Although vascularized bone grafts promote osteogenesis, the required tissue harvesting causes problematic donor-site morbidity. Artificial bone substitutes are promising alternatives for regenerative medicine applications, but the incorporation of suitable cells and/or growth factors is necessary for their successful clinical application. The inclusion of vascular bundles can further enhance the bone-forming capability of bone substitutes by promoting tissue neovascularization. Little is known about how neovascularization occurs and how new bone extends within vascularized tissue-engineered bone, because no previous studies have used tissue-engineered bone to treat large, poorly vascularized defects. METHODS: In this study, the authors developed a novel vascularized tissue-engineered bone scaffold composed of osteogenic matrix cell sheets wrapped around vascular bundles within β-tricalcium phosphate ceramics. RESULTS: Four weeks after subcutaneous transplantation in rats, making use of the femoral vascular bundle, vascularized tissue-engineered bone demonstrated more angiogenesis and higher osteogenic potential than the controls. After vascularized tissue-engineered bone implantation, abundant vascularization and new bone formation were observed radially from the vascular bundle, with increased mRNA expression of alkaline phosphatase, bone morphogenetic protein-2, osteocalcin, and vascular endothelial growth factor-A. CONCLUSION: This novel method for preparing vascularized tissue-engineered bone scaffolds may promote the regeneration of large bone defects, particularly where vascularization has been compromised.博士（医学）・甲第652号・平成28年3月15日Copyright © 2016 American Society of Plastic Surgeons All rights reserved.This is a non-final version of an article published in final form in "http://dx.doi.org/10.1097/PRS.0000000000002079

Multidimensional imaging of liver injury repair in mice reveals fundamental role of the ductular reaction

Upon severe and/or chronic liver injury, ectopic emergence and expansion of atypical biliary epithelial-like cells in the liver parenchyma, known as the ductular reaction, is typically induced and implicated in organ regeneration. Although this phenomenon has long been postulated to represent activation of facultative liver stem/progenitor cells that give rise to new hepatocytes, recent lineage-tracing analyses have challenged this notion, thereby leaving the pro-regenerative role of the ductular reaction enigmatic. Here, we show that the expanded and remodelled intrahepatic biliary epithelia in the ductular reaction constituted functional and complementary bile-excreting conduit systems in injured parenchyma where hepatocyte bile canalicular networks were lost. The canalicular collapse was an incipient defect commonly associated with hepatocyte injury irrespective of cholestatic statuses, and could sufficiently provoke the ductular reaction when artificially induced. We propose a unifying model for the induction of the ductular reaction, where compensatory biliary epithelial tissue remodeling ensures bile-excreting network homeostasis

Uso de "stents" no tratamento de lesões arteriais intimas de origem traumática: relato de caso

O tratamento de lesões arteriais íntimais de origem traumática é controversa pela sua evolução natural ser desconhecida. As opções terapêuticas atuais incluem reconstrução arterial e observação clínica. A idéia da utilização de "stents" para a correção de descolamentos intimais é baseada no seu uso em dissecções, "flaps" e irregularidades da artéria após angioplastia com balão. Descrevemos o tratamento bem sucedido de um descolamento de íntima da artéria femoral superficial causado por ferimento de arma de fogo com a utilização de um "stent" de Palmaz na fase aguda. Um ano após a implantação do "stent", o duplex scan mostrou fluxo normal pela artéria com a exclusão completa do descolamento de íntima, com pulsos distais palpáveis e com o paciente completamente assintomático.Treatment of arterial traumatic intimal lesions is controversial due to its unknown natural history. Current therapeutical options include arterial reconstruction and clinical observation. The idea of using stents to correct intimal flaps is based on their use to correct dissections, flaps, and arterial irregularities after angioplasty. We report the successful treatment of a traumatic intimal flap of the superficial femoral artery, caused by gunshot trauma, with a Palmaz stent in the acute period. One year after the operation, a duplex scan revealed normal flow in the artery and complete exclusion of the intimal flap; distal pulses were palpable, and the patient was completely asymptomatic

トラウマ ノ コウゾウカ カイジ ガ ガイショウゴ ストレス ハンノウ ト ワーキング メモリ ヨウリョウ ニ オヨボス エイキョウ : ガイショウゴ ストレス ハンノウ オ チョウキ ニ ワタッテ イジ サセテイル コジン オ タイショウ ト シタ ケントウ

The first purpose of this study was to establish effective structured disclosure for the reduction of the post traumatic stress reactions (PTSR) than the free disclosure. The second purpose was to investigate whether the disclosure of the trauma brought the increase of the working memory capacity (WMC).Individuals who have maintained PTSR more than six months were selected as participants. Sixteen participants were randomly assigned to one of the three groups: structured disclosure group (S)，free disclosure group (F)，control group (C). To enhance cognitive restructuring of the trauma，the S group was required to describe the trauma following detailed instructions. In addition，they were asked to rate the conviction degree for the negative cognitions about the trauma quantitatively. The F group was asked to describe the trauma as freely as they remember it. The C group was asked to write about neutral topics. Measures were Impact of Event scale and WMC scores. Results indicated that only the structured disclosure significantly decreased the degree of the PTSR. Although the WMC scores increased in the S group，there was not the significant difference. Thus，the further research is needed to modify the procedures of cognitive restructuring and to increase the number of participants

Mechanism of Isotactic Styrene Polymerization with a C6F5‑Substituted Bis(phenoxyimine) Titanium System

We report a combined, experimental and theoretical, study of styrene polymerization to clarify the regio- and stereocontrol mechanism operating with a C6F5-substituted bis(phenoxyimine) titanium dichloride complex. Styrene homopolymerization, styrene−propene and styrene− ethene−propene copolymerizations have been carried out to this aim. A combination of 13C NMR analysis of the chain-end groups and of the microstructure of the homopolymers and copolymers reveals that styrene polymerization is highly regioselective and occurs prevalently through 2,1- monomer insertion. DFT calculations evidenced that steric interaction between the growing chain and the monomer in the transition state insertion stage is at the origin of this selectivity. The formation of isotactic polystyrene with a chain-end like microstructure is rationalized on the base of a mechanism similar to that proposed for the syndiospecific propene polymerization catalyzed by bis(phenoxyimine) titanium dichloride complexes. Finally, a general stereocontrol mechanism operative in olefin polymerization with this class of complexes is proposed

Scintigraphic studies on the etiology of Ampulla Cardiomyopathy

SummaryBackgroundAlthough there are many reports on Ampulla Cardiomyopathy, its etiologic mechanisms are not well known.AimEtiology of Ampulla Cardiomyopathy was investigated by myocardial scintigraphy with various nuclear tracers.Subjects and methodsIn nine patients with Ampulla Cardiomyopathy, myocardial scintigraphy was performed at acute, subacute and chronic phases. Total defect score (TDS) of tallium-201 (Tl) or technetrium-99m sestamibi (MIBI) myocardial perfusion and iodine-123-beta-methyl-p-iodophenyl penta-decanoic acid (BMIPP) scintigraphies was calculated. Cardio-mediastinal ratio (H/M) and washout rate (WR) of early and delayed images of iodine-123-meta-iodobenzylguanidine (MIBG) scintigraphy were also calculated. The patients in whom TDS of myocardial perfusion scintigraphy at acute phase was 0, were classified into group N (n=5) and those with TDS≥1 into group D (n=4).ResultsTDS of BMIPP at acute, subacute and chronic phases was higher in D than in N; 28.8±10.3 vs. 7.2±4.7 (p=0.0039), 15.5±2.1 vs. 1.0±0.8 (p<0.0001) and 2.7±1.2 vs. 0 (p=0.05), respectively. WR of MIBG at acute phase was also higher in D (50.3±5.7% vs. 36.6±10.5%, p=0.05). H/M (dH/M) on the delayed images and WR at chronic phase were not different between the two groups. H/M (eH/M) on the early images was lower in D. Blood noradrenaline (ng/ml) at acute phase was higher in D than in N (1.21±0.55 vs. 0.45±0.33, p<0.05). Left ventricular ejection fraction (LVEF) was decreased in both at acute phase but it was lower in D than in N (48.1±3.7% vs. 69.9±9.7%, p<0.05) at subacute phase.ConclusionThese findings suggest that the etiology of Ampulla Cardiomyopathy is neurologically stunned myocardium induced by coronary microcirculatory disorder.Due to the significant amount of time that was necessary for normalization of wall motion in the D group, myocardial scintigraphy is believed to be also useful in assessment of severity