Proliferating cells in the adult primate cerebellar cortex after ischemia

INTRODUCTION: Brain ischemia is a devastating neurological condition with significant medical and social impact. Here we investigated the effect of experimental ischemia of different duration on the ability of the adult macaque cerebellum to produce new cells of specific phenotypes.MATERIAL AND METHODS: We used a well-established model of global brain ischemia in young adult Japanese monkeys applying bromodeoxyuridine (BrdU) for 5 days х 100 mg/kg daily. Animals were distributed into different experimental and control groups depending on postischemic survival periods: 4, 9, 15, 23, 44 days (D) and BrdU starting day. Immunohistochemical detection of BrdU+ cells, Iba1+ microglia and GFAP+ astroglia was performed on cryosections. Statistical evaluation of newly generated cells with phenotyping for microglia and astrocytes in various cortical layers of the cerebellum were done.RESULTS and CONCLUSIONS: The numbers of BrdU+ cells in some ischemic groups were significantly higher compared to control animals. By cerebrocerebellum, there was an increasing value by D4 group compared to the control, then slightly reducing in D9 and D15 groups and increasing again by D23 and D44 groups. In the spinocerebellum, an increase was detected only in D44 group. The newly generated cells were dispersed in all cerebellar cortical layers with highest concentration in Purkinje cell layer. Our data show that ischemia stimulates cellular proliferation in the cerebellum but this effect declines with time after ischemia. We found evidence for generation of new microglia but not for astroglia. Our data may contribute to a better understanding of regeneration in the cerebellum after brain ischemia

Urban adaptation to climate change in Europe: Challenges and opportunities for cities together with supportive national and European policies

Climate change leading to higher temperatures, changing precipitation patterns and sea level rise, is a reality in Europe. Climate change mitigation measures will limit the magnitude and rate of related events in the future, but they will not prevent them. Pro-active adaptation to climate change is therefore imperative. While urban adaptation to climate change at a first glance may seem to be purely a local governance issue, the strong connections between European cities and their surrounding regions, or countries, warrant a broader perspective

ΔI=4\Delta I=4 and ΔI=8\Delta I=8 bifurcations in rotational bands of diatomic molecules

It is shown that the recently observed $\Delta I=4$ bifurcation seen in superdeformed nuclear bands is also occurring in rotational bands of diatomic molecules. In addition, signs of a $\Delta I=8$ bifurcation, of the same order of magnitude as the $\Delta I=4$ one, are observed both in superdeformed nuclear bands and rotational bands of diatomic molecules.Comment: LaTex twice, 10 pages and 5 PS figures provided upon demand by the Author

Morphological Transformations of Galaxies in the A901/02 Supercluster from STAGES

We present a study of galaxies in the Abell 901/902 Supercluster at z~0.165, based on HST ACS F606W, COMBO-17, Spitzer 24um, XMM-Newton X-ray, and gravitational lensing maps, as part of the STAGES survey. We characterize galaxies with strong externally-triggered morphological distortions and normal relatively undisturbed galaxies, using visual classification and quantitative CAS parameters. We compare normal and distorted galaxies in terms of their frequency, distribution within the cluster, star formation properties, and relationship to dark matter (DM) or surface mass density, and intra-cluster medium (ICM) density. We revisit the morphology density relation, which postulates a higher fraction of early type galaxies in dense environments, by considering separately galaxies with a low bulge-to-disk (B/D) ratio and a low gas content as these two parameters may not be correlated in clusters. We report here on our preliminary analysis.Comment: To appear in the ASP conference proceedings of the "Frank N. Bash Symposium 2007: New Horizons in Astronomy", Eds. A. Frebel, J. Maund, J. Shen, M. Siegel. 4 pages, 4 figure

Wnt4 and LAP2alpha as pacemakers of Thymic Epithelial Senescence

Age-associated thymic involution has considerable physiological impact by inhibiting de novo T-cell selection. This impaired T-cell production leads to weakened immune responses. Yet the molecular mechanisms of thymic stromal adipose involution are not clear. Age-related alterations also occur in the murine thymus providing an excellent model system. In the present work structural and molecular changes of the murine thymic stroma were investigated during aging. We show that thymic epithelial senescence correlates with significant destruction of epithelial network followed by adipose involution. We also show in purified thymic epithelial cells the age-related down-regulation of Wnt4 (and subsequently FoxN1), and the prominent increase in LAP2α expression. These senescence-related changes of gene expression are strikingly similar to those observed during mesenchymal to pre-adipocyte differentiation of fibroblast cells suggesting similar molecular background in epithelial cells. For molecular level proof-of-principle stable LAP2α and Wnt4-over-expressing thymic epithelial cell lines were established. LAP2α over-expression provoked a surge of PPARγ expression, a transcription factor expressed in pre-adipocytes. In contrast, additional Wnt4 decreased the mRNA level of ADRP, a target gene of PPARγ. Murine embryonic thymic lobes have also been transfected with LAP2α- or Wnt4-encoding lentiviral vectors. As expected LAP2α over-expression increased, while additional Wnt4 secretion suppressed PPARγ expression. Based on these pioneer experiments we propose that decreased Wnt activity and increased LAP2α expression provide the molecular basis during thymic senescence. We suggest that these molecular changes trigger thymic epithelial senescence accompanied by adipose involution. This process may either occur directly where epithelium can trans-differentiate into pre-adipocytes; or indirectly where first epithelial to mesenchymal transition (EMT) occurs followed by subsequent pre-adipocyte differentiation. The latter version fits better with literature data and is supported by the observed histological and molecular level changes