Results 71 to 80 of about 1,082,995 (200)

‘The big chunky belemnite’: a new relict megateuthidid from the Oxfordian (Late Jurassic) of Wyoming, USA, and its place in the evolutionary history of the group

Papers in Palaeontology, Volume 12, Issue 5, September/October 2026.
Abstract We describe and discuss two finds of large and untypical belemnite rostra originating from the upper part of the Sundance Formation (Oxfordian) of Wyoming, USA. With a diameter reaching c. 60 mm at the anterior end, these rostra are the thickest known for belemnites so far.
Alexey P. Ippolitov, Jessica L. Lippincott, William R. Wahl, Dean R. Lomax   +3 more
wiley   +1 more source

On maximal immediate extensions of valued division algebras [PDF]

, 2003
We show an extension theorem for strictly contracting bilinear mappings into a spherically complete valued vector space and we apply this result to prove that every maximal valued division algebra having the same characteristic as its residue division ...
Schörner, Erwin
core   +1 more source

Multi‐Sensor Logger Tracking Reveals the Threats of Offshore Windfarms to Passerine‐Sized Birds

Conservation Letters, Volume 19, Issue 5, September/October 2026.
ABSTRACT Offshore wind energy is a cornerstone of the transition to renewable energy, yet its rapid expansion raises concerns for wildlife. These concerns notably involve small migratory birds whose movements across marine barriers and therefore potential interactions with offshore wind turbines remain poorly understood.
Paul Doniol‐Valcroze, Ian Beggs, Fraser Bell, Pierrick Bocher, Malcolm Burgess, Greg Conway, Yannig Coulomb, Sophie de Grissac, Rose Delacroix, Paul Dufour, Catrin F. Eden, Chris Hewson, Kevin Leighton, Raphaël Nussbaumer, Fanny Rey, Stuart P. Sharp, Frédéric Jiguet   +16 more
wiley   +1 more source

Mal'tsev objects, R_1-spaces and ultrametric spaces

Theory and Applications of Categories, 2017
In this paper we introduce a notion of Mal'tsev object, and the dual notion of co-Mal'tsev object, in a general category. In particular, a category $\mathbb{C}$ is a Mal'tsev category if and only if every object in $\mathbb{C}$ is a Mal'tsev object.
openaire   +3 more sources

On homogeneous ultrametric spaces

, 2015
A metric space M is homogeneous if every isometry between finite subsets extends to a surjective isometry defined on the whole space. We show that if M is an ultrametric space, it suffices that isometries defined on singletons extend, i.e that the group of isometries of M acts transitively. We derive this fact from a result expressing that the arity of
Delhomme, C., Laflamme, C., Pouzet, M., Sauer, N.   +3 more
openaire   +2 more sources

Concentrated vulnerabilities in bees: Diet specialists have smaller geographic ranges

Insect Conservation and Diversity, Volume 19, Issue 5, Page 1114-1123, September 2026.
Niche breadth theory predicts a positive association between range size and diet breadth, which could concentrate risk among specialists, but this is not well established for bees. Using global occurrence data (range size) and natural history collection‐derived pollen data (diet breadth), we compared these traits in 633 species from six families and ...
Charles N. Thrift, Thomas J. Wood, An Bui, Hillary S. Young, Katja C. Seltmann   +4 more
wiley   +1 more source

Hyperbolic Metric Spaces and Stochastic Embeddings

Forum of Mathematics, Sigma
Stochastic embeddings of finite metric spaces into graph-theoretic trees have proven to be a vital tool for constructing approximation algorithms in theoretical computer science.
Chris Gartland
doaj   +1 more source

Orderability and continuous selections for Wijsman and Vietoris hyperspaces

Applied General Topology, 2003
Bertacchi and Costantini obtained some conditions equivalent to the existence of continuous selections for the Wijsman hyperspace of ultrametric Polish spaces. We introduce a new class of hypertopologies, the macro-topologies.
Debora Di Caprio, Stephen Watson
doaj   +1 more source

Cryptic diversity and recent diversification in the Pyrrhulina australis species complex (Characiformes, Lebiasinidae) revealed by mitochondrial DNA

Journal of Fish Biology, Volume 109, Issue 3, Page 1771-1785, September 2026.
Abstract Pyrrhulina australis Eigenmann & Kennedy, 1903, is widely distributed across the main hydrographic basins of South America. The taxonomic integrity of this species is nevertheless challenged by the lack of clear diagnostic characters, its marked geographic variation and the morphological overlap with its congeners. In this context, the present
Taina Barbosa De Souza, Daniela Cristina Ferreira, Hugmar Pains Da Silva, Carolina B. Machado, Claudio Oliveira, André L. Netto‐Ferreira, Paulo C. Venere   +6 more
wiley   +1 more source

Max–min measures on ultrametric spaces

Topology and its Applications, 2013
The ultrametrization of the set of all probability measures of compact support on the ultrametric spaces was first defined by Hartog and de Vink. In this paper we consider a similar construction for the so called max-min measures on the ultrametric spaces. In particular, we prove that the functors max-min measures and idempotent measures are isomorphic.
Cencelj, Matija, Repovš, Dušan, Zarichnyi, Michael   +2 more
openaire   +2 more sources