A Conversation with Pranab Kumar Sen

Pranab Kumar Sen was born on November 7, 1937 in Calcutta, India. His father died when Pranab was 10 years old, so his mother raised the family of seven children. Given his superior performance on an exam, Pranab nearly went into medical school, but did not because he was underage. He received a B.Sc. degree in 1955 and an M.Sc. degree in 1957 in statistics from Calcutta University, topping the class both times. Dr. Sen's dissertation on order statistics and nonparametrics, under the direction of Professor Hari Kinkar Nandi, was completed in 1961. After teaching for three years at Calcutta University, 1961--1964, Professor Sen came to Berkeley as a Visiting Assistant Professor in 1964. In 1965, he joined the Departments of Statistics and Biostatistics at the University of North Carolina at Chapel Hill, where he has remained. Professor Sen's pioneering contributions have touched nearly every area of statistics. He is the first person who, in joint collaboration with Professor S. K. Chatterjee, developed multivariate rank tests as well as time-sequential nonparametric methods. He is also the first person who carried out in-depth research in sequential nonparametrics culminating in his now famous Wiley book Sequential Nonparametrics: Invariance Principles and Statistical Inference and SIAM monograph. Professor Sen has over 600 research publications. In addition, he has authored or co-authored 11 books and monographs, and has edited or co-edited 11 more volumes. He has supervised over 80 Ph.D. students, many of whom have achieved distinction both nationally and internationally. Professor Sen is the founding co-editor of two international journals: Sequential Analysis and Statistics and Decisions.Comment: Published in at http://dx.doi.org/10.1214/08-STS255 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

The role of the Caenorhabditis elegans E4 enzyme UFD-2 in DNA damage repair and apoptosis

DNA double-strand breaks (DSBs) are major threats for the genome of a cell and if left unrepaired they may lead to severe genomic instability which can result in apoptosis. In order to cope with DSBs a tight spatiotemporal regulation of DNA repair factors is required. These factors are recruited to lesions where they form nuclear foci to repair the damage. Timely repair is mandatory, as persisting unprocessed DSBs in pachytene nuclei of the Caenorhabditis elegans (C. elegans) germline trigger apoptosis. Yet unknown signals seem to be transmitted between the DNA damage response (DDR) and apoptosis. To allow quick responding, signaling is likely mediated by post-translational modification (PTM) of proteins located at these foci. Ubiquitylation is emerging as an important PTM in the DDR, regulating the proteasomemediated degradation of DDR-players or their displacement from chromatin. Thus, E3 ubiquitin ligases have been identified to be prominent factors in the damage response. This study demonstrates that the C. elegans E4 ligase UFD-2, a specialized form of an E3 ligase, with its binding partner the ubiquitin-selective segregase CDC-48/p97 accumulates rad-51 dependent in ionizing radiation induced nuclear foci (IRIF) in the apoptosis prone pachytene zone of the germline. The recruitment of UFD-2 and CDC-48 is independently from each other. However, impaired binding between both proteins results in misregulated UFD-2 foci, possibly caused by disturbed segregase function of CDC-48. Moreover, experiments measuring the embryonic sensitivity to IR confirm a role of UFD-2 in homologous recombination mediated DNA repair. These findings suggest that the E4 ligase UFD-2 regulates the abundance of substrates at IRIF which might serve as mediators between the DDR and apoptosis. Consistently, ufd-2 positively regulates IR-induced apoptosis and a deletion of ufd-2 results in inefficient apoptosis, correlating with persisting RAD-51 foci indicating persisting unprocessed DSBs. This study establishes a new function of UFD-2 in the displacement of an anti-apoptotic signal at sites of homologous recombination that needs to be removed for proceeding of apoptosis. It prevents undesired cell death when the damage repair is still in progress but unleashes the power of apoptosis if the DNA repair fails

Pilgrimage events for the Hungarian Germans / Danube Swabians in the North of the archbishopric of Freiburg after World War II: Walldürn and the "Paulusheim" near Bruchsal

This essay seeks to consider a particular form of spirituality: the pilgrimage events of the “Danube Swabians” shortly after their arrival in South-West Germany following the Second World War. In terms of the time span, the focus will be on the years 1946-1949 – a phase during which the future forms of government had not yet been constituted in Central Europe.The essay wishes to reflect on two key aspects, namely that (a) these early events afford a tangibly Hungarian spiritual aspect, and (b) entirely practical, functional aspects also came into effect at these events. The essay expands on contemporary theories, which are currently the subject of international debate, with an evaluation of new archive materials

Comparing the Evolution of Risk Culture in Radiation Oncology, Aviation, and Nuclear Power

Objectives: All organizations seek to minimize the risks that their operations pose to public safety. This task is especially significant if they deal with complex or hazardous technologies. Five decades of research in quantitative risk analysis have generated a set of risk management frameworks and practices that extend across a range of such domains. Here, we investigate the risk culture in three commercial enterprises that require exceedingly high standards of execution: radiation oncology, aviation, and nuclear power. Methods: One of the characteristics of high reliability organizations is their willingness to learn from other such organizations. We investigate the extent to which this is true by compiling a database of the major publications on risk within each of the three fields. We conduct a bibliographic coupling analysis on the combined database to identify connections among publications. This analysis reveals the strength of engagement across disciplinary boundaries and the extent of cross-adoption of best practices. Results: Our results show that radiation oncology is more insulated than the other two fields in its adoption and propagation of state-of-the-art risk management tools and frameworks that have transformed aviation and nuclear power into high reliability enterprises with actuarially low risk. Conclusions: Aviation and nuclear power have established risk cultures that cross-pollinate. In both nature and extent, we found a distinct difference in radiation oncology's engagement with the risk community, and it lags behind the other two fields in implementing best practices that might mitigate or eliminate risks to patient safety

Field assisted sintering of Ta–Al2_2O3_3 composite materials and investigation of electrical conductivity

Ta–Al$_2$O$_3$ composite samples with different compositions are prepared using Field Assisted Sintering Technique (FAST). Two different alumina powders are used to investigate the influence of the starting powders particle size on the microstructural features and the resulting electrical conductivity of the prepared composite materials. Percolation threshold of the two material systems is influenced by the metal fraction, as well as the alumina particle size of the starting powder. The percolation threshold for the fine- and the coarse-grained alumina is found to be at 15 vol.-% Ta and 7.5 vol.-% Ta, respectively. Microstructural investigations show significant differences in terms of particle shape of both, Ta and Al$_2$O$_3$ after sintering, most likely being the reason for the different percolation thresholds of the investigated materials. Anisotropy effects resulting from the processing using FAST and the influence on electrical properties are also shown

Enhancement of the Zero Phonon Line emission from a Single NV-Center in a Nanodiamond via Coupling to a Photonic Crystal Cavity

Using a nanomanipulation technique a nanodiamond with a single nitrogen vacancy center is placed directly on the surface of a gallium phosphide photonic crystal cavity. A Purcell-enhancement of the fluorescence emission at the zero phonon line (ZPL) by a factor of 12.1 is observed. The ZPL coupling is a first crucial step towards future diamond-based integrated quantum optical devices

Field‐Assisted Sintering of Nb–Al2_2O3_3 Composite Materials and Investigation of Electrical Conductivity

Field-assisted sintering technique (FAST) is used for the preparation of Nb–Al$_2$O$_3$ composite materials. The electrical conductivity is investigated depending on the particle size of the used starting powders and under varying volume contents of the refractory metal in the starting powder mixture. The percolation threshold is investigated and found to be influenced not only by the metal fraction but also by the particle size of the alumina used for sample preparation. For the fine- and coarse-grained alumina, a percolation threshold of 17.5 and 10 vol% Nb is estimated, respectively. Furthermore, the microstructure is investigated to gain a basic understanding of the dependency between microstructural features and the resulting material properties on the macroscopic scale. Also, the influence of the sintering process and the resulting microstructure–properties relationship is considered. It could be shown that the electrical properties are anisotropic because of anisotropy effects caused by the FAST process