منابع مشابه
7 billion and counting.
The world is currently in the midst of the greatest demographic upheaval in human history. Dramatic reductions in mortality, followed (but with a lag) by equally marked reductions in fertility, resulted in a doubling of world population between 1960 and 2000. A further increase of 2 to 4.5 billion is projected for the current half-century, with the increase concentrated in the world's least dev...
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The UK's Millennium Seed Bank, part of the Royal Botanic Gardens, Kew, has collected its billionth seed for safekeeping and conservation. The seed was presented to the British chancellor, Gordon Brown, ahead of an official ceremony at the Seed Bank in southern England late last month to mark World Biodiversity Day. The Millennium Seed Bank (MSB) Project is one of the most ambitious conservation...
متن کاملCounting of Moore Families for n=7
Given a set Un = {0, 1, ..., n−1}, a collectionM of subsets of Un that is closed under intersection and contains Un is known as a Moore family. The set of Moore families for a given n, denoted by Mn, increases very quickly with n, thus |M3| is 61 and |M4| is 2480. In [1] the authors determined the number for n = 6 and stated a 24hcomputation-time. Thus, the number for n = 7 can be considered as...
متن کامل0.5 billion events per second time correlated single photon counting using CMOS SPAD arrays.
We present a digital architecture for fast acquisition of time correlated single photon counting (TCSPC) events from a 32×32 complementary metal oxide semiconductor (CMOS) single photon avalanche detector (SPAD) array (Megaframe) to the computer memory. Custom firmware was written to transmit event codes from 1024-TCSPC-enabled pixels for fast transfer of TCSPC events. Our 1024-channel TCSPC sy...
متن کاملThe Mesoproterozoic – no “boring billion”
The authors show that the Mesoproterozoic (1.6-1.0 bn year before present) was no “boring billion” but a “bustling billion” - not only with Stromatolites and their apex in the Calymmian and Ectasian but also with the presence of multicellular organisms. To make it visible a graphical reconstruction was created. For a long time, it was assumed that there existed no noteworthy biosphere on Earth ...
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ژورنال
عنوان ژورنال: Science
سال: 2011
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.1209290