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Current European flood-rich period exceptional compared with past 500 years 期刊论文
NATURE, 2020, 583 (7817) : 560-+
作者:  ;  nter Blö;  schl;  Andrea Kiss;  Alberto Viglione;  Mariano Barriendos;  Oliver Bö;  hm;  Rudolf Brá;  zdil;  Denis Coeur;  Gaston Demaré;  e;  Maria Carmen Llasat;  Neil Macdonald;  Dag Retsö;  Lars Roald;  Petra Schmocker-Fackel;  Inê;  s Amorim;  Monika Bě;  ;  nová;  Gerardo Benito;  Chiara Bertolin;  Dario Camuffo;  Daniel Cornel;  Radosł;  aw Doktor;  ;  bor Elleder;  Silvia Enzi;  Joã;  o Carlos Garcia;  ;  diger Glaser;  Julia Hall;  Klaus Haslinger;  Michael Hofstä;  tter;  ;  rgen Komma;  Danuta Limanó;  wka;  David Lun;  Andrei Panin;  Juraj Parajka;  Hrvoje Petrić;  Fernando S. Rodrigo;  Christian Rohr;  Johannes Schö;  nbein;  Lothar Schulte;  Luí;  s Pedro Silva;  Willem H. J. Toonen;  Peter Valent;  ;  rgen Waser;  Oliver Wetter
收藏  |  浏览/下载:84/0  |  提交时间:2020/08/09

There are concerns that recent climate change is altering the frequency and magnitude of river floods in an unprecedented way(1). Historical studies have identified flood-rich periods in the past half millennium in various regions of Europe(2). However, because of the low temporal resolution of existing datasets and the relatively low number of series, it has remained unclear whether Europe is currently in a flood-rich period from a long-term perspective. Here we analyse how recent decades compare with the flood history of Europe, using a new database composed of more than 100 high-resolution (sub-annual) historical flood series based on documentary evidence covering all major regions of Europe. We show that the past three decades were among the most flood-rich periods in Europe in the past 500 years, and that this period differs from other flood-rich periods in terms of its extent, air temperatures and flood seasonality. We identified nine flood-rich periods and associated regions. Among the periods richest in floods are 1560-1580 (western and central Europe), 1760-1800 (most of Europe), 1840-1870 (western and southern Europe) and 1990-2016 (western and central Europe). In most parts of Europe, previous flood-rich periods occurred during cooler-than-usual phases, but the current flood-rich period has been much warmer. Flood seasonality is also more pronounced in the recent period. For example, during previous flood and interflood periods, 41 per cent and 42 per cent of central European floods occurred in summer, respectively, compared with 55 per cent of floods in the recent period. The exceptional nature of the present-day flood-rich period calls for process-based tools for flood-risk assessment that capture the physical mechanisms involved, and management strategies that can incorporate the recent changes in risk.


Analysis of thousands of historical documents recording floods in Europe shows that flooding characteristics in recent decades are unlike those of previous centuries.


  
Origin of complexity in haemoglobin evolution 期刊论文
NATURE, 2020
作者:  Cheema, Suraj S.;  Kwon, Daewoong;  Shanker, Nirmaan;  dos Reis, Roberto;  Hsu, Shang-Lin;  Xiao, Jun;  Zhang, Haigang;  Wagner, Ryan;  Datar, Adhiraj;  McCarter, Margaret R.;  Serrao, Claudy R.;  Yadav, Ajay K.;  Karbasian, Golnaz;  Hsu, Cheng-Hsiang;  Tan, Ava J.;  Wang, Li-Chen;  Thakare, Vishal;  Zhang, Xiang;  Mehta, Apurva;  Karapetrova, Evguenia;  Chopdekar, Rajesh, V;  Shafer, Padraic;  Arenholz, Elke;  Hu, Chenming;  Proksch, Roger;  Ramesh, Ramamoorthy;  Ciston, Jim;  Salahuddin, Sayeef
收藏  |  浏览/下载:81/0  |  提交时间:2020/07/03

Most proteins associate into multimeric complexes with specific architectures(1,2), which often have functional properties such as cooperative ligand binding or allosteric regulation(3). No detailed knowledge is available about how any multimer and its functions arose during evolution. Here we use ancestral protein reconstruction and biophysical assays to elucidate the origins of vertebrate haemoglobin, a heterotetramer of paralogous alpha- and beta-subunits that mediates respiratory oxygen transport and exchange by cooperatively binding oxygen with moderate affinity. We show that modern haemoglobin evolved from an ancient monomer and characterize the historical '  missing link'  through which the modern tetramer evolved-a noncooperative homodimer with high oxygen affinity that existed before the gene duplication that generated distinct alpha- and beta-subunits. Reintroducing just two post-duplication historical substitutions into the ancestral protein is sufficient to cause strong tetramerization by creating favourable contacts with more ancient residues on the opposing subunit. These surface substitutions markedly reduce oxygen affinity and even confer cooperativity, because an ancient linkage between the oxygen binding site and the multimerization interface was already an intrinsic feature of the protein'  s structure. Our findings establish that evolution can produce new complex molecular structures and functions via simple genetic mechanisms that recruit existing biophysical features into higher-level architectures.


Experimental analysis of reconstructed ancestral globins reveals that haemoglobin'  s complex tetrameric structure and oxygen-binding functions evolved by simple genetic and biophysical mechanisms.


  
Ant diversity in Brazilian tropical dry forests across multiple vegetation domains 期刊论文
ENVIRONMENTAL RESEARCH LETTERS, 2017, 12 (3)
作者:  Silva, Luciana Figueiredo;  Souza, Rayana Mello;  Solar, Ricardo R. C.;  Neves, Frederico de Siqueira
收藏  |  浏览/下载:9/0  |  提交时间:2019/04/09
alpha diversity  beta diversity  historical mechanisms  regional scale  species turnover  transitional zones