Examples and Counterexamples for Existence of Categorical Quotients

We give examples for existence and non-existence of categorical quotients for algebraic group actions in the categories of algebraic varieties and prevarieties. All our examples are subtorus actions on toric varieties.Comment: 15 pages, 3 figures, LaTeX2e + pste

Orbit spaces of small tori

Consider an algebraic torus of small dimension acting on an open subset of a complex vector space, or more generally on a quasiaffine variety such that a separated orbit space exists. We discuss under which conditions this orbit space is quasiprojective. One of our counterexamples provides a toric variety with enough effective invariant Cartier divisors that is not embeddable into a smooth toric variety.Comment: 11 pages, 1 figur

Photoionization of Galactic Halo Gas by Old Supernova Remnants

We present new calculations on the contribution from cooling hot gas to the photoionization of warm ionized gas in the Galaxy. We show that hot gas in cooling supernova remnants (SNRs) is an important source of photoionization, particularly for gas in the halo. We find that in many regions at high latitude this source is adequate to account for the observed ionization so there is no need to find ways to transport stellar photons from the disk. The flux from cooling SNRs sets a floor on the ionization along any line of sight. Our model flux is also shown to be consistent with the diffuse soft X-ray background and with soft X-ray observations of external galaxies. We consider the ionization of the clouds observed towards the halo star HD 93521, for which there are no O stars close to the line of sight. We show that the observed ionization can be explained successfully by our model EUV/soft X-ray flux from cooling hot gas. In particular, we can match the H alpha intensity, the S++/S+ ratio, and the C+* column. From observations of the ratios of columns of C+* and either S+ or H0, we are able to estimate the thermal pressure in the clouds. The slow clouds require high (~10^4 cm^-3 K) thermal pressures to match the N(C+*)/N(S+) ratio. Additional heating sources are required for the slow clouds to maintain their ~7000 K temperatures at these pressures, as found by Reynolds, Hausen & Tufte (1999).Comment: AASTeX 5.01; 34 pages, 2 figures; submitted to Astrophysical Journa

Evaluation der Expression von PDGFR-β, VEGF-ab1, Ki-67 und Bcl-2 zur Therapieprädiktion bei Riesenzelltumoren des Skelettsystems

Diese Studie untersucht die prognostische Relevanz von PDGFR-ß, VEGF-ab1, Ki-67 und Bcl-2 bei ossären Riesenzelltumoren zwecks zielgerichteter molekularer Therapien. MATERIAL UND METHODEN: Mittels TMA-Verfahren wurden 112 Biopsien auf die Expression der Faktoren untersucht und den klinischen Verläufen gegenübergestellt. SIGNIFIKANTE ERGEBNISSE: 87,2 % zeigten im Stroma keine Expression für Bcl-2. Der Anteil gering oder mittelstark angefärbter Proben war mit je 3,7% sehr gering. 70,3% der Gewebeproben zeigte keine oder geringe Expression von Ki-67. Für VEGF konnte bei je 13,8% eine leichte und mittelstarke Färbung nachgewiesen werden. 97,2% des Stromas zeigte eine Expression von PDGFR-ß. Es bestand keine Korrelation der Ergebnisse mit Rezidiven, Metastasen oder Malignität. DISKUSSION UND SCHLUSSFOLGERUNG: Die Expression der untersuchten Faktoren ist bei RZT kein prognostischer Parameter. PDGFR-ß und VEGF sind eventuell Ansatzpunkte für Angiogenese-Hemmstoffe in der RZT-Therapie

Relationship Between Plasma Glucose Levels and Malignant Uterine Cervical Neoplasias

Background There is a direct correlation between glycemic load and the risk of developing many malignant neoplasms. Aims The aim of this study was to determine the plasma glucose levels in women with cervical cancer. Methods The study included 177 women with anatomopathologically diagnosed uterine cervical cancer (stages 0–IV) treated between 1980 and 2008 at the Gynecology and Obstetrics outpatient service of the UFTM, Brazil. The plasma glucose levels of all patients were assayed at the time of diagnosis and correlated with tumor staging. Results We statistically compared the plasma glucose levels of group 1 (cervical intraepithelial neoplasia 2–3), group 2 (stage I–II), group 3 (stage III–IV), and group 4 (control group: leiomyomas). Patient groups with poor prognosis (groups 2 and 3) showed significantly higher plasma glucose levels ( P 90 mg/dl showed CIN versus I/II: P = 0.0753; OR = 2.018; (95% CI: 0.9236 to 4.410) and CIN versus III/IV: P = 0.0975; OR = 2.400; (95% CI: 0.8335 to 6.911). Conclusion We observed an association between high plasma glucose levels and cervical cancer cases with poor prognoses. Plasma glucose tests should be routinely used as additional prognostic parameters in patients with cervical neoplasias