Results 41 to 50 of about 21,160 (248)
The Anatomical Record, EarlyView.Abstract Phylogenetic comparative methods have been used in recent literature to work with laws and test for regularities (evolutionary associations of quantitative features) and evolutionary singularities (features that evolved in a single taxon). We analyzed these uses epistemologically, taking the evolution of red‐blood‐cell mean corpuscular volume (
Jorge Cubo +3 more
wiley +1 more source
, 1985 Topics addressed include: meteorite concentration mechanisms; meteorites and the Antarctic ice sheet; iron meteorites; iodine overabundance in meteorites; entrainment, transport, and concentration of meteorites in polar ice sheets; weathering of stony ...
core
Magnetic classification of stony meteorites: 3. Achondrites
, 2009 A database of magnetic susceptibility measurements of stony achondrites (acapulcoitelodranite clan, winonaites, ureilites, angrites, aubrites, brachinites, howardite-eucrite-diogenite (HED) clan, and Martian meteorites, except lunar meteorites) is ...
Pesones, L. +7 more
core +1 more source
The Richardton Meteorite [PDF]
The Journal of Geology, 1919 At 9:48 P.M. Mountain time, June 30, I918,' a meteorite was seen to fall in the country between Richardton and Mott, North Dakota. Pieces fell on both sides of the line between Stark and Hettinger counties within a strip about 9 miles wide from north to south and 5 miles wide from east to west. The center of this area lies in altitude 46037'30" N.
openaire +2 more sources
Uncatalyzed Guanosine Phosphorylation under Potentially Prebiotic Conditions
Chemistry – A European Journal, EarlyView.Pyrophosphate acts as phosphorylating agent of guanosine under simple wet‐dry cycles without condensing agent and inorganic catalysts to afford cyclic guanosine monophosphate derivatives useful for oligomerization in prebiotic processes. ABSTRACT The phosphorylation of nucleosides and their subsequent polymerization are key issues in the study of the ...
Martina Proietti +5 more
wiley +1 more source
The life and work of Ernest Sydney Keeping
Canadian Journal of Statistics, EarlyView.Abstract This article reviews the life and contributions of Ernest S. Keeping (1895–1984), a British‐born physicist who became a mathematics professor at the University of Alberta in 1929. He played a pivotal role in shaping the university's Mathematics Department, serving as its head from 1954 to 1961, and continuing to teach until 1970, nine years ...
David R. Bellhouse, Christian Genest
wiley +1 more source
Proceedings of the National Academy of Sciences, 2011 Primitive meteorites, interplanetary dust particles, and comets contain dust grains that formed around stars that lived their lives before the solar system formed. These remarkable objects have been intensively studied since their discovery a little over twenty years ago and they provide samples of other stars that can be studied in the laboratory in ...
openaire +2 more sources
Geological Journal, EarlyView.Chemical states of Se and Br atoms in the KPg boundary sediments from Stevns Klint were studied using XAFS spectroscopy. The high concentrations of Se4+ could become an index of the degree to which the global environment was soiled with dust and ash derived from impact ejecta or volcanic eruptions.
Kei‐ichiro Murai +5 more
wiley +1 more source
The stellar origins of 96Zr excesses in presolar graphites from the Murchison meteorite
Astronomy & AstrophysicsContext. Zirconium-96 is a stable isotope that can be synthesized under different neutron-rich nucleosynthetic conditions. Astrophysical models predict its production to occur in various stellar environments: from low-to-intermediate-mass asymptotic ...
Pal I. +16 more
doaj +1 more source