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How do resource mobility and group size affect institutional arrangements for rule enforcement? A qualitative comparative analysis of fishing groups in South Korea 期刊论文
ECOLOGICAL ECONOMICS, 2020, 174
作者:  Shin, Hoon C.;  Yu, David J.;  Park, Samuel;  Anderies, John M.;  Abbott, Joshua K.;  Janssen, Marco A.;  Ahn, T. K.
收藏  |  浏览/下载:13/0  |  提交时间:2020/05/13
Common-pool resources  Design principles  Voice option  Resource mobility  Group size  Institutional fit  
APOE4 leads to blood-brain barrier dysfunction predicting cognitive decline 期刊论文
NATURE, 2020, 581 (7806) : 70-+
作者:  Doherty, Tiarnan A. S.;  Winchester, Andrew J.;  Macpherson, Stuart;  Johnstone, Duncan N.;  Pareek, Vivek;  Tennyson, Elizabeth M.;  Kosar, Sofiia;  Kosasih, Felix U.;  Anaya, Miguel;  Abdi-Jalebi, Mojtaba;  Andaji-Garmaroudi, Zahra;  Wong, E. Laine;  Madeo, Julien;  Chiang, Yu-Hsien;  Park, Ji-Sang;  Jung, Young-Kwang;  Petoukhoff, Christopher E.;  Divitini, Giorgio;  Man, Michael K. L.;  Ducati, Caterina;  Walsh, Aron;  Midgley, Paul A.;  Dani, Keshav M.;  Stranks, Samuel D.
收藏  |  浏览/下载:25/0  |  提交时间:2020/07/03

Breakdown of the blood-brain barrier in individuals carrying the epsilon 4 allele of the APOE gene, but not the epsilon 3 allele, increases with and predicts cognitive impairment and is independent of amyloid beta or tau pathology.


Vascular contributions to dementia and Alzheimer'  s disease are increasingly recognized(1-6). Recent studies have suggested that breakdown of the blood-brain barrier (BBB) is an early biomarker of human cognitive dysfunction(7), including the early clinical stages of Alzheimer'  s disease(5,8-10). The E4 variant of apolipoprotein E (APOE4), the main susceptibility gene for Alzheimer'  s disease(11-14), leads to accelerated breakdown of the BBB and degeneration of brain capillary pericytes(15-19), which maintain BBB integrity(20-22). It is unclear, however, whether the cerebrovascular effects of APOE4 contribute to cognitive impairment. Here we show that individuals bearing APOE4 (with the epsilon 3/epsilon 4 or epsilon 4/epsilon 4 alleles) are distinguished from those without APOE4 (epsilon 3/epsilon 3) by breakdown of the BBB in the hippocampus and medial temporal lobe. This finding is apparent in cognitively unimpaired APOE4 carriers and more severe in those with cognitive impairment, but is not related to amyloid-beta or tau pathology measured in cerebrospinal fluid or by positron emission tomography(23). High baseline levels of the BBB pericyte injury biomarker soluble PDGFR beta(7,8) in the cerebrospinal fluid predicted future cognitive decline in APOE4 carriers but not in non-carriers, even after controlling for amyloid-beta and tau status, and were correlated with increased activity of the BBB-degrading cyclophilin A-matrix metalloproteinase-9 pathway(19) in cerebrospinal fluid. Our findings suggest that breakdown of the BBB contributes to APOE4-associated cognitive decline independently of Alzheimer'  s disease pathology, and might be a therapeutic target in APOE4 carriers.


  
Extant timetrees are consistent with a myriad of diversification histories 期刊论文
NATURE, 2020, 580 (7804) : 502-+
作者:  Bhaskar, M. K.;  Riedinger, R.;  Machielse, B.;  Levonian, D. S.;  Nguyen, C. T.;  Knall, E. N.;  Park, H.;  Englund, D.;  Loncar, M.;  Sukachev, D. D.;  Lukin, M. D.
收藏  |  浏览/下载:19/0  |  提交时间:2020/07/03

An infinite number of alternative diversification scenarios-which may have markedly different, but equally plausible, dynamics-can underpin a given time-calibrated phylogeny of extant species, suggesting many previous studies have over-interpreted phylogenetic evidence.


Time-calibrated phylogenies of extant species (referred to here as '  extant timetrees'  ) are widely used for estimating diversification dynamics(1). However, there has been considerable debate surrounding the reliability of these inferences(2-5) and, to date, this critical question remains unresolved. Here we clarify the precise information that can be extracted from extant timetrees under the generalized birth-death model, which underlies most existing methods of estimation. We prove that, for any diversification scenario, there exists an infinite number of alternative diversification scenarios that are equally likely to have generated any given extant timetree. These '  congruent'  scenarios cannot possibly be distinguished using extant timetrees alone, even in the presence of infinite data. Importantly, congruent diversification scenarios can exhibit markedly different and yet similarly plausible dynamics, which suggests that many previous studies may have over-interpreted phylogenetic evidence. We introduce identifiable and easily interpretable variables that contain all available information about past diversification dynamics, and demonstrate that these can be estimated from extant timetrees. We suggest that measuring and modelling these identifiable variables offers a more robust way to study historical diversification dynamics. Our findings also make it clear that palaeontological data will continue to be crucial for answering some macroevolutionary questions.


  
Mechanical regulation of glycolysis via cytoskeleton architecture 期刊论文
NATURE, 2020, 578 (7796) : 621-+
作者:  Faivre, Emily J.;  McDaniel, Keith F.;  Albert, Daniel H.;  Mantena, Srinivasa R.;  Plotnik, Joshua P.;  Wilcox, Denise;  Zhang, Lu;  Bui, Mai H.;  Sheppard, George S.;  Wang, Le;  Sehgal, Vasudha;  Lin, Xiaoyu;  Huang, Xiaoli;  Lu, Xin;  Uziel, Tamar;  Hessler, Paul;  Lam, Lloyd T.;  Bellin, Richard J.;  Mehta, Gaurav;  Fidanze, Steve;  Pratt, John K.;  Liu, Dachun;  Hasvold, Lisa A.;  Sun, Chaohong;  Panchal, Sanjay C.;  Nicolette, John J.;  Fossey, Stacey L.;  Park, Chang H.;  Longenecker, Kenton;  Bigelow, Lance;  Torrent, Maricel;  Rosenberg, Saul H.;  Kati, Warren M.;  Shen, Yu
收藏  |  浏览/下载:15/0  |  提交时间:2020/07/03

The mechanics of the cellular microenvironment continuously modulates cell functions such as growth, survival, apoptosis, differentiation and morphogenesis via cytoskeletal remodelling and actomyosin contractility(1-3). Although all of these processes consume energy(4,5), it is unknown whether and how cells adapt their metabolic activity to variable mechanical cues. Here we report that the transfer of human bronchial epithelial cells from stiff to soft substrates causes a downregulation of glycolysis via proteasomal degradation of the rate-limiting metabolic enzyme phosphofructokinase (PFK). PFK degradation is triggered by the disassembly of stress fibres, which releases the PFK-targeting E3 ubiquitin ligase tripartite motif (TRIM)-containing protein 21 (TRIM21). Transformed non-small-cell lung cancer cells, which maintain high glycolytic rates regardless of changing environmental mechanics, retain PFK expression by downregulating TRIM21, and by sequestering residual TRIM21 on a stress-fibre subset that is insensitive to substrate stiffness. Our data reveal a mechanism by which glycolysis responds to architectural features of the actomyosin cytoskeleton, thus coupling cell metabolism to the mechanical properties of the surrounding tissue. These processes enable normal cells to tune energy production in variable microenvironments, whereas the resistance of the cytoskeleton in response to mechanical cues enables the persistence of high glycolytic rates in cancer cells despite constant alterations of the tumour tissue.


Glycolysis in normal epithelial cells responds to microenvironmental mechanics via the modulation of actin bundles that sequester the phosphofructokinase-targeting ubiquitin ligase TRIM21, a process superseded by persistent actin bundles in cancer cells.