Manifolds with large isotropy groups

We classify all simply connected Riemannian manifolds whose isotropy groups act with cohomogeneity less than or equal to two.Comment: 21 page

Cross border mergers and strategic trade policy with two-part taxation: is international policy coordination beneficial?

We analyse how national taxation of firms are likely to affect merger incentives in international markets. In particular, we ask whether non-coordinated trade policies stimulate cross-border mergers that are overall inefficient, and if this is then an argument for international coordination of such policies? We address this issue in a setting where policy makers use two-part tariffs to tax exporting firms. The analysis reveals that while non-coordinated policies may induce cross-border mergers (by allowing the firms in question to play national policy makers out against each other), this can nevertheless be overall welfare enhancing compared to market outcomes under coordinated policy making. -- Das Papier untersucht die möglichen Wirkungen der nationalen Besteuerung auf Anreize für Fusionen in internationalen Märkten. Dabei wird vor allem gefragt, ob unkoordinierte Handelspolitik zu grenzüberschreitenden Fusionen führt, die insgesamt ineffizient sind und ob das für die internationale Koordination der Handelspolitik spricht. Im vorgestellten Modellrahmen nutzen Politikentscheider zweiseitige Zölle um Exportfirmen zu besteuern. Die Untersuchung zeigt, dass zwar nichtkoordinierte Politik grenzüberschreitende Fusionen hervorbringt, indem die beteiligten Firmen ihre nationalen Gesetzgeber gegeneinander ausspielen können; allerdings ist das Ergebnis durchaus wohlfahrtssteigernd im Vergleich zu dem Marktergebnis, das sich aus koordinierter Handelspolitik ergibt.Strategic trade policy,two-part taxation,endogenous merger,policy coordination

Access regulation and cross-border mergers: Is international coordination beneficial?

The international integration of regulated markets poses new challenges for regulatory policy. One question is the implications that the overall international regulatory regime will have for cross-border and/or domestic merger activity. In particular, do non-coordinated policies stimulate cross-border mergers that are overall inefficient, and is this then an argument for international coordination of such policies? The paper addresses this issue in a setting where firms must have access to a transportation network which is controlled by national regulators. The analysis reveals that while non-coordinated regulatory policies may induce cross-border mergers (by allowing the firms in question to play national regulators out against each other), this can nevertheless be overall welfare enhancing compared to market outcomes under coordinated regulation.Access regulation; Endogenous merger; Policy coordination

Clifford algebras and new singular Riemannian foliations in spheres

Using representations of Clifford algebras we construct indecomposable singular Riemannian foliations on round spheres, most of which are non-homogeneous. This generalizes the construction of non-homogeneous isoparametric hypersurfaces due to by Ferus, Karcher and Munzner.Comment: 21 pages. Construction of foliations in the Cayley plane added. Proofs simplified and presentation improved, according to referee's suggestions. To appear in Geom. Funct. Ana

Cross-border mergers and strategic trade policy with two-part taxation: is international policy coordination beneficial?

"Das Papier untersucht die möglichen Wirkungen der nationalen Besteuerung auf Anreize für Fusionen in internationalen Märkten. Dabei wird vor allem gefragt, ob unkoordinierte Handelspolitik zu grenzüberschreitenden Fusionen führt, die insgesamt ineffizient sind und ob das für die internationale Koordination der Handelspolitik spricht. Im vorgestellten Modellrahmen nutzen Politikentscheider zweiseitige Zölle um Exportfirmen zu besteuern. Die Untersuchung zeigt, dass zwar nichtkoordinierte Politik grenzüberschreitende Fusionen hervorbringt, indem die beteiligten Firmen ihre nationalen Gesetzgeber gegeneinander ausspielen können; allerdings ist das Ergebnis durchaus wohlfahrtssteigernd im Vergleich zu dem Marktergebnis, das sich aus koordinierter Handelspolitik ergibt." (Autorenreferat)"We analyse how national taxation of firms are likely to affect merger incentives in international markets. In particular, we ask whether non-coordinated trade policies stimulate cross-border mergers that are overall inefficient, and if this is then an argument for international coordination of such policies? We address this issue in a setting where policy makers use two-part tariffs to tax exporting firms. The analysis reveals that while non-coordinated policies may induce cross-border mergers (by allowing the firms in question to play national policy makers out against each other), this can nevertheless be overall welfare enhancing compared to market outcomes under coordinated policy making." (author's abstract

Wide-range monitor for pulsed x-ray sources

A monitoring instrument based on a high-pressure ionization chamber has been developed that measures average dose rates as low as 0.1 mR/h and responds linearly to short pulses at dose rates up to 1.2 x 10/sup 10/ R/h. Its sensitivity can be remotely changed by a factor of 10/sup 4/, to enable accurate measurement of both background radiation and very high intensities such as can be expected from accelerator beam-spills. The instrument's detector-electrometer pulse response was measured using a dose-calibrated field-emission accelerator having a 30-ns pulse width

Strong expression of ID1 protein is associated with decreased survival, increased expression of ephrin-A1/EPHA2, and reduced thrombospondin-1 in malignant melanoma

The ID1 protein, an inhibitor of basic helix–loop–helix transcription factors, has been involved in multiple cellular processes including cell cycle regulation, apoptosis, and angiogenesis. To evaluate the importance of ID1 in malignant melanoma, tumour cell expression was examined by immunohistochemistry in 119 cases of nodular melanoma using tissue microarray technique, and related to multiple tumour markers including proliferation, p16 expression, angiogenesis and patient survival. Strong ID1 expression was significantly associated with increased tumour thickness, and significantly reduced survival. Also, increased ID1 was associated with loss of thrombospondin-1 (TSP-1) expression, a known inhibitor of angiogenesis, and increased intensity of ephrin-A1 and its receptor EPHA2. Presence of BRAF mutations was related to strong ID1 expression, but there was no relationship with p16 protein expression. Further, no significant correlation was found between ID1 and microvessel density. In conclusion, our study supports a significant role of the ID1 protein in melanoma progression and patient prognosis. The absence of correlation with p16 protein expression and angiogenesis suggests that other regulatory pathways and mechanisms might be influenced by ID1 in melanomas. An inverse relation between ID1 and TSP-1 expression support an important role of ID1 in the regulation of this complex multitarget protein

Memberships and CM Diagrams of the Open Cluster NGC 7243

The results of astrometric and photometric investigations of the open cluster NGC 7243 are presented. Proper motions of 2165 stars with root-mean-square error of 1.1 mas/yr were obtained by means of PDS scanning of astrometric plates covering the time interval of 97 years. A total of 211 cluster members down to V=15.5 mag have been identified. V and B magnitudes have been determined for 2118 and 2110 stars respectively. Estimations of mass (348Mo < M < 522Mo), age (t=2.5x10^8 yr), distance (r=698 pc) and reddening (E(B-V)=0.24) of the cluster NGC 7243 have been made.Comment: 24 pages, 15 figures. Submitted to Astronomy and Astrophysic

41Ca in tooth enamel. part I: A biological signature of neutron exposure in atomic bomb survivors

The detection of 41Ca atoms in tooth enamel using accelerator mass spectrometry is suggested as a method capable of reconstructing thermal neutron exposures from atomic bomb survivors in Hiroshima and Nagasaki. In general, 41Ca atoms are produced via thermal neutron capture by stable 40Ca. Thus any 41Ca atoms present in the tooth enamel of the survivors would be due to neutron exposure from both natural sources and radiation from the bomb. Tooth samples from five survivors in a control group with negligible neutron exposure were used to investigate the natural 41Ca content in tooth enamel, and 16 tooth samples from 13 survivors were used to estimate bomb-related neutron exposure. The results showed that the mean 41Ca/Ca isotope ratio was (0.17 ± 0.05) × 10-14 in the control samples and increased to 2 × 10-14 for survivors who were proximally exposed to the bomb. The 41Ca/Ca ratios showed an inverse correlation with distance from the hypocenter at the time of the bombing, similar to values that have been derived from theoretical free-in-air thermal-neutron transport calculations. Given that γ-ray doses were determined earlier for the same tooth samples by means of electron spin resonance (ESR, or electron paramagnetic resonance, EPR), these results can serve to validate neutron exposures that were calculated individually for the survivors but that had to incorporate a number of assumptions (e.g. shielding conditions for the survivors).Fil: Wallner, A.. Ludwig Maximilians Universitat; Alemania. Universitat Technical Zu Munich; Alemania. Universidad de Viena; AustriaFil: Ruhm, W.. Helmholtz Center Munich German Research Center For Environmental Health; Alemania. Ludwig Maximilians Universitat; AlemaniaFil: Rugel, G.. Ludwig Maximilians Universitat; Alemania. Universitat Technical Zu Munich; AlemaniaFil: Nakamura, N.. Radiation Effects Research Foundation; JapónFil: Arazi, Andres. Universitat Technical Zu Munich; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Faestermann, T.. Universitat Technical Zu Munich; AlemaniaFil: Knie, K.. Universitat Technical Zu Munich; Alemania. Ludwig Maximilians Universitat; AlemaniaFil: Maier, H. J.. Ludwig Maximilians Universitat; AlemaniaFil: Korschinek, G.. Universitat Technical Zu Munich; Alemani