Results 191 to 200 of about 1,644,826 (290)

Pyrite morphology and sulfur isotopes refine taphonomic models for the 2.1 Ga Francevillian biota, Gabon. [PDF]

Sci Rep
El Khoury A, Saleh F, El Albani A, Fontaine C, Rollion-Bard C, Chraiki I, Aubineau J, Ngwal'ghoubou Ikouanga J, Bhilisse M, Zguaid M, Somogyi A, Chi Fru E.   +11 more
europepmc   +1 more source

Chemical Ionization Mass Spectrometry: Fundamental Principles, Diverse Applications, and the Latest Technological Frontiers

Mass Spectrometry Reviews, EarlyView.
ABSTRACT The review examines the evolution of chemical ionization mass spectrometry (CI‐MS), a technique developed in 1966 by Field and Munson. CI is a soft‐ionization method that produces more intense molecular ions with less fragmentation than electron ionization (EI).
Malvika Dutt, Adriana Arigò, Giorgio Famiglini, Pierangela Palma, Achille Cappiello   +4 more
wiley   +1 more source

Production of secondary particles from cosmic ray interactions in the earth's atmosphere: Implications for annual effective dose, 14C/12C ratio, and magnetic field effects. [PDF]

PLoS One
Hassanpour M, Rezaie M, Heydarizade Y, Rashed Iqbal Faruque M, Hassanpour M.   +4 more
europepmc   +1 more source

A Review of Bioarcheological Investigations in Iron Age Cambodia

International Journal of Osteoarchaeology, EarlyView.
ABSTRACT Archeological research within Cambodia is quite extensive, with significant projects led by both Cambodian archeologists and international researchers alike. Many of these projects have uncovered human skeletal remains. This article reviews archeological human skeletal studies in Cambodia, synthesizing published and unpublished data, primarily
Sophorn Nhoem, Kate Domett, Nigel Chang
wiley   +1 more source

Impacts of reindeer grazing on phosphorus sorption and nutrient availability in a tundra site

Oikos, EarlyView.
Reindeer Rangifer tarandus, a large circumpolar herbivore, can influence whether nitrogen (N) or phosphorus (P) is the primary limiting nutrient in tundra plant communities. Specifically, findings from a site in northern Scandinavia suggest that under conditions where reindeer grazing stimulates inorganic N availability, grazing may drive ecosystems ...
Jerzy Szejgis, Johan Olofsson, Henni Ylänne, Michael J. Gundale, Reiner Giesler, Maja K. Sundqvist   +5 more
wiley   +1 more source

Stable isotope evidence of anthropocene disruption in African softshell turtle foraging. [PDF]

PLoS One
de Kock W, van der Meer MTJ, van Bommel R, Taurozzi AJ, Von Tersch M, Allentoft ME, Mackie M, Ramsøe M, Collins M, Alexander M, Palsbøll PJ, Çakırlar C, Turkozan O.   +12 more
europepmc   +1 more source

Temporal changes in the dietary niche of sympatric seals provides insight into the role of competition in population declines

Oikos, EarlyView.
Competition theory suggests that interspecific prey competition can result in changes to the dietary niche, but obtaining timeseries of data from sympatric species experiencing temporal variation in competition is challenging. Scotland is an important area for two species of seals, but over the past 20 years, populations of harbour seals Phoca vitulina
Izzy Langley, Philip S. Hammond, Paul M. Thompson, Graham J. Pierce, Lindsay J. Wilson, Ailsa J. Hall, Gordon D. Hastie, Debbie J. F. Russell   +7 more
wiley   +1 more source

Volcanism and basalt weathering drove Ordovician climatic cooling. [PDF]

Nat Commun
Zhao H, Zhang L, Algeo TJ, Lyu Z, Wang X, Hao F.   +5 more
europepmc   +1 more source

2,3‐Dichloro‐5,6‐Dicyano‐1,4‐Benzoquinone (DDQ)‐Mediated CC Bond Formation: Redox Strategies from Stoichiometric to Catalytic Systems

ChemistryOpen, EarlyView.
2,3‐Dichloro‐5,6‐dicyano‐1,4‐benzoquinone serves as a versatile oxidant and redox catalyst for CC bond formation through hydride abstraction or single‐electron transfer. Stoichiometric and catalytic systems enable benzylic, allylic, and aromatic CH activation under mild, metal‐free conditions, providing sustainable routes to complex and bioactive ...
Dohoon Cha, Sun‐Joon Min
wiley   +1 more source

Dynamic redox-promoted iron and nutrient cycling drove graptolite evolution across the Ordovician-Silurian transition. [PDF]

Sci Adv
Qiu Z, Zou C, Zhang J, Dong A, Kong W, Xiong Y, Wignall PB, Li M, Wang Z, Zhu X, Poulton SW.   +10 more
europepmc   +1 more source