Stable homotopy groups of spheres.

We discuss the current state of knowledge of stable homotopy groups of spheres. We describe a computational method using motivic homotopy theory, viewed as a deformation of classical homotopy theory. This yields a streamlined computation of the first 61 stable homotopy groups and gives information about the stable homotopy groups in dimensions 62 through 90.

Living alone predicts mortality in patients with ischemic stroke before 70 years of age: a long-term prospective follow-up study.

Background: Living alone is associated with increased mortality after myocardial infarction but little data is available about whether this applies to prognosis after stroke. We aimed to examine the association between living situation and long-term mortality in patients with ischemic stroke and a control group, and to explore whether this association is modified by patient gender.

Methods: This is a prospective case-control study of 600 patients with ischemic stroke before 70 years of age and 600 age- and sex-matched controls who have been included in the Sahlgrenska Study on Ischemic Stroke.

Uncoupling of proliferation and Stat5 activation in thymic stromal lymphopoietin-mediated signal transduction.

Thymic stromal lymphopoietin (TSLP) is a cytokine that facilitates B lymphocyte differentiation and costimulates T cells. Previous studies have demonstrated that a functional TSLP receptor complex is a heterodimer consisting of the TSLP receptor and the IL-7R alpha-chain. TSLP-mediated signaling is unique among members of the cytokine receptor family in that activation of the transcription factor Stat5 occurs without detectable Janus kinase activation.

Requirement for stat5 in thymic stromal lymphopoietin-mediated signal transduction.

Thymic stromal lymphopoietin (TSLP) is a newly identified cytokine that uniquely promotes B lymphopoiesis to the B220+/IgM+ immature B cell stage. In addition, TSLP shares many biological properties with the related cytokine IL-7. This can be explained by the finding that the receptor complexes for TSLP and IL-7 both contain the IL-7R alpha-chain; IL-7Ralpha is paired with the common gamma-chain (gammac) in the IL-7 receptor complex and the unique TSLP-R chain in the TSLP receptor complex.