15 research outputs found

    The complex genetics of gait speed:Genome-wide meta-analysis approach

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    Emerging evidence suggests that the basis for variation in late-life mobility is attributable, in part, to genetic factors, which may become increasingly important with age. Our objective was to systematically assess the contribution of genetic variation to gait speed in older individuals. We conducted a meta-analysis of gait speed GWASs in 31,478 older adults from 17 cohorts of the CHARGE consortium, and validated our results in 2,588 older adults from 4 independent studies. We followed our initial discoveries with network and eQTL analysis of candidate signals in tissues. The meta-analysis resulted in a list of 536 suggestive genome wide significant SNPs in or near 69 genes. Further interrogation with Pathway Analysis placed gait speed as a polygenic complex trait in five major networks. Subsequent eQTL analysis revealed several SNPs significantly associated with the expression of PRSS16, WDSUB1 and PTPRT, which in addition to the meta-analysis and pathway suggested that genetic effects on gait speed may occur through synaptic function and neuronal development pathways. No genome-wide significant signals for gait speed were identified from this moderately large sample of older adults, suggesting that more refined physical function phenotypes will be needed to identify the genetic basis of gait speed in aging

    GWAS analysis of handgrip and lower body strength in older adults in the CHARGE consortium

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    Decline in muscle strength with aging is an important predictor of health trajectory in the elderly. Several factors, including genetics, are proposed contributors to variability in muscle strength. To identify genetic contributors to muscle strength, a meta-analysis of genomewide association studies of handgrip was conducted. Grip strength was measured using a handheld dynamometer in 27 581 individuals of European descent over 65 years of age from 14 cohort studies. Genomewide association analysis was conducted on ~2.7 million imputed and genotyped variants (SNPs). Replication of the most significant findings was conducted using data from 6393 individuals from three cohorts. GWAS of lower body strength was also characterized in a subset of cohorts. Two genomewide significant (P-value< 5 × 10−8) and 39 suggestive (P-value< 5 × 10−5) associations were observed from meta-analysis of the discovery cohorts. After meta-analysis with replication cohorts, genomewide significant association was observed for rs752045 on chromosome 8 (β = 0.47, SE = 0.08, P-value = 5.20 × 10−10). This SNP is mapped to an intergenic region and is located within an accessible chromatin region (DNase hypersensitivity site) in skeletal muscle myotubes differentiated from the human skeletal muscle myoblasts cell line. This locus alters a binding motif of the CCAAT/enhancer-binding protein-β (CEBPB) that is implicated in muscle repair mechanisms. GWAS of lower body strength did not yield significant results. A common genetic variant in a chromosomal region that regulates myotube differentiation and muscle repair may contribute to variability in grip strength in the elderly. Further studies are needed to uncover the mechanisms that link this genetic variant with muscle strength

    Extracting FSA descriptions of robot behaviours from the dynamics of automatically designed controller networks

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    Automatic design has become a common approach to evolve complex networks, such as artificial neural networks (ANNs) and random boolean networks (RBNs), and many evolutionary setups have been discussed to increase the efficiency of this process. However networks evolved in this way have few limitations that should not be overlooked. One of these limitations is the black-box problem that refers to the impossibility to analyze internal behaviour of complex networks in an efficient and meaningful way. The aim of this study is to develop a methodology that make it possible to extract finite-state automata (FSAs) descriptions of robot behaviours from the dynamics of automatically designed complex controller networks. These FSAs unlike complex networks from which they're extracted are both readable and editable thus making the resulting designs much more valuable

    The Story of a Stone: Mi Fu’s Ink-Grinding Stone and its Eighteenth-Century Replications

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    1790 年 、 北 京 で 手 の 形 を し た 驚 く べ き 研 山 ( 硯 山 〔 硯 の 一 種 で 盆 石 と し て も 鑑 賞 さ れ る 。 起 伏 の 多 い 石 を 用 い 中 央 の 平 ら な 部 分 を 硯 と し て 使 っ た も の 。 起 伏 の 部 分 に 筆 を 横 に し て も た せ か け る こ と が で き る 〕 ) が 出 現 し て 、 古 物 愛 好 家 た ち の 好 奇 心 を 駆 り 立 て た 。 「 宝 晋 斎 研 山 」 と 呼 ば れ る そ の 石 は 、 形 態 も さ る こ と な が ら 、 来 歴 も 驚 く べ き も の だ っ た 。 十 国 南 唐 ( 江 南 ) の 最 後 の 国 主 ・ 李 煜 ( り ・ い く 、 937~ 978 年 ) の た め に デ ザ イ ン さ れ 、 北 宋 末 の 書 家 ・ 画 家 ・ 蒐 集 家 と し て 有 名 な 米 芾 ( べ い ・ ふ つ 、 1051~ 1107 年 ) が 入 手 し た こ と が あ る 研 山 だ っ た か ら で あ る 。 翁 方 綱 ( 1738~ 1818 年 ) が そ れ を 詳 細 に 研 究 し 、 そ の 結 果 を 2 枚 の 絵 画 と 2 枚 の 石 刷 り か ら な る 4 つ の 図 を 含 ん だ 長 い 巻 子 本 と し て 著 わ し 、 彼 の 発 見 を 共 有 し た 。 彼 は 、 当 時 の 新 し い 観 念 だ っ た 考 証 学 的 原 理 に 基 づ き 、 そ れ ま で に そ の 石 の 来 歴 や 特 徴 に つ い て 流 布 し て い た 伝 説 を 排 し 、 新 た に 経 験 に よ っ て 明 ら か に さ れ た 事 実 の み を 探 求 し よ う と し た 。 そ れ な ら ば 、 彼 は な ぜ 、 そ の 石 を 絵 画 に よ っ て 示 そ う と し た の か ?   本 論 は 、 18 世 紀 後 半 の 中 国 に お け る 古 物 研 究 に 特 徴 的 な 、 学 問 的 正 確 さ の 追 究 と 芸 術 的 イ マ ジ ネ ー シ ョ ン の 間 の 密 接 な 関 係 を 、 翁 方 綱 と 彼 の 仕 事 に 参 加 し た 芸 術 家 た ち の 努 力 の 中 に 見 出 そ う と す る も の で あ る 。In 1790, a prodigious ink-grinding stone (yanshan) in the shape of a hand resurfaced in Beijing, attracting the curiosity of local antiquarians. Its shape was as exceptional as its provenance: designed for Li Yu (937–978), it was among the treasures of Mi Fu’s (1051–1107) legendary collection. Weng Fanggang (1738–1818) studied the stone first-hand and shared his discoveries in an essay written on a long scroll made up of four representations of the stone, two paintings and two rubbings. Guided by the new principle of objectivity, Weng sought to discard all apocryphal accounts of its history and properties in favour of fresh, empirically grounded evidence. Why then present this material in a painting? This essay reconstructs the efforts made by Weng Fanggang and his artists to capture the most authentic image of the stone, examining the many ways academic rigour became inextricable from artistic imagination in the late eighteenth-century antiquarians’ pursuit of the past.En 1790, une extraordinaire pierre à encre (yanshan) en forme de main refit surface à Pékin, attirant la curiosité des antiquaires locaux. Sa forme était aussi exceptionnelle que sa provenance : conçue pour Li Yu (937-978), elle avait fait partie des trésors de la collection légendaire de Mi Fu (1051-1107). Weng Fanggang (1738-1818) l’a alors étudiée de près et a partagé ses découvertes dans un essai écrit sur un long rouleau où se trouvent également quatre représentations de la pierre : deux peintures et deux estampages. Guidé par le nouveau principe de l’objectivité, Weng a mis à l’épreuve tous les récits apocryphes relatifs à l’histoire et aux propriétés de la pierre, en les confrontant aux nouvelles preuves empiriques. Pourquoi présenter ce matériel sur une peinture ? Cet article présente les efforts déployés par Weng Fanggang et ses artistes pour capturer l’image la plus authentique de la pierre, exposant comment la rigueur académique est devenue inséparable de l’imagination artistique dans la quête du passé propre à la fin du XVIIIe siècle.1790 年 一 塊 形 狀 為 手 的 名 為 “ 研 山 ” 的 奇 特 研 墨 石 在 北 京 古 玩 市 場 出 現 , 受 到 了 金 石 學 家 注 意 。 它 的 形 狀 和 出 處 都 不 同 凡 響 : 最 初 是 為 南 唐 後 主 李 煜 ( 937-978) 量 身 定 做 , 之 後 成 為 宋 朝 書 法 家 米 芾 ( 1051-1107) 的 收 藏 。 翁 方 綱 ( 1738-1818) 近 距 離 觀 察 了 這 塊 研 墨 石 , 把 其 發 現 作 為 短 文 書 寫 在 一 卷 長 捲 軸 上 , 還 伴 隨 有 兩 幅 “ 研 山 ” 的 繪 畫 畫 和 兩 幅 相 關 拓 片 。 在 當 時 考 證 學 影 響 下 , 翁 方 綱 試 圖 摒 棄 與 這 塊 “ 研 山 ” 歷 史 和 特 點 有 關 的 杜 撰 故 事 而 進 行 更 為 腳 踏 實 地 的 研 究 。 為 什 麼 要 在 畫 中 表 現 “ 研 山 ”? 本 文 重 構 了 翁 方 綱 和 他 手 下 藝 術 家 為 了 盡 可 能 真 實 的 描 繪 “ 研 山 ” 圖 像 所 進 行 的 努 力 , 展 現 了 十 八 世 紀 末 期 考 證 學 是 如 何 開 始 影 響 藝 術 想 象 力 的 。Matteini Michele. The Story of a Stone: Mi Fu’s Ink-Grinding Stone and its Eighteenth-Century Replications. In: Arts asiatiques, tome 72, 2017. pp. 81-96

    Visualizzazione real-time della diffusione subacquea della luce

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    ‘China: the empire of things’: Jason Steuber and Nick Pearce, Original Intentions: Essays on the Production, Reproduction, and Interpretation in the Arts of China, Gainesville, FL: University of Florida Press 2012

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    Original Intentions: Essays on the Production, Reproduction, and Interpretation in the Arts of China is a collection of studies on the creation, circulation, and reception of three-dimensional objects from the Bronze Age to the modern times. This review concentrates on the volume’s methodological approach to and conceptual framing of issues like authenticity, and originality. The essay brings the volume and individual essays in relation to ongoing debates on materiality and making in the fields of Chinese and Western art, arguing for the possibility of a cross-cultural history of the material world

    Structural differences between toxic and nontoxic HypF-N oligomers

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    We have studied two misfolded oligomeric forms of the protein HypF-N, which show similar morphologies but very different toxicities. We measured over 80 intermolecular distance-dependent parameters for each oligomer type using FRET, in conjunction with solution- and solid-state NMR and other biophysical techniques. The results indicate that the formation of a highly organised hydrogen bonded core in the toxic oligomers results in the exposure of a larger number of hydrophobic residues than in the nontoxic species, causing the former to form aberrant interactions with cellular components
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