HIF2 keeps paces in tight hypoxic spaces

Tight supply keeps oil prices soaring

Transcription in tight spaces

n meiosis II, vertebrate oocytes undergo a cell cycle arrest that is maintained until fertilization, but it has been difficult to identify the factors responsible for this process. By screening a novel cDNA library, Lefebvre et al., page 603, have discovered and characterized a protein that specifically regulates meiosis II spindle integrity during arrest. The work helps to explain how the cell...

In tight spaces

Positronium (Ps) is the bound state of an electron and its antiparticle, the positron [1]. It is made purely of leptons and, as such, provides a unique opportunity for studying bound-state, two-body quantum electrodynamics and the effect of virtual annihilation that occurs between a particle and an antiparticle in a bound state. So far, experimentalists performing precision measurements [2] of ...

On Σ-countably Tight Spaces

Extending a result of R. de la Vega, we prove that an infinite homogeneous compactum has cardinality c if either it is the union of countably many dense or finitely many arbitrary countably tight subspaces. The question if every infinite homogeneous and σ-countably tight compactum has cardinality c remains open. We also show that if an arbitrary product is σ-countably tight then all but finitel...

Tight Equivariant Immersions of Symmetric Spaces

Introduction. Let G/K be a compact, irreducible symmetric space and Q = f+p the Lie algebra of G. If ir is a non trivial real class-one representation of G on E with O^e, infixed, then the map TlG/K —*E given by gK—*ir{g)e gives an immersion of G/K into E. The purpose of this note is to announce the classification of such immersions with minimal absolute curvature (i.e., are tight) [ l ] , [4]....