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Parameterised Pushdown Systems with Non-Atomic Writes  [PDF]
Matthew Hague
Computer Science , 2011,
Abstract: We consider the master/slave parameterised reachability problem for networks of pushdown systems, where communication is via a global store using only non-atomic reads and writes. We show that the control-state reachability problem is decidable. As part of the result, we provide a constructive extension of a theorem by Ehrenfeucht and Rozenberg to produce an NFA equivalent to certain kinds of CFG. Finally, we show that the non-parameterised version is undecidable.
Centennial to millennial geomagnetic field variations  [cached]
Korte Monika,Muscheler Raimund
Journal of Space Weather and Space Climate , 2012, DOI: 10.1051/swsc/2012006
Abstract: Reconstructions of the geomagnetic field in the past represent a useful tool not only to investigate the geodynamo process, but also to estimate the effect of geomagnetic shielding for any studies on cosmogenic radionuclides and galactic cosmic rays. A number of new millennial-scale geomagnetic field reconstructions have been published over the last years, based on improved global archeo- and paleomagnetic data compilations. Here we review several spherical harmonic models and compare their dipole field predictions to reconstructions based on virtual axial dipole moments and virtual geomagnetic poles. Dipole intensity estimates from cosmogenic radionuclide production records, with suitable filtering to minimise the solar influence, have also been included in the comparison to provide independent information about variations in the strength of the geomagnetic field. However, due to differences among geomagnetic models and between 14C and 10Be production records this comparison is fairly inconclusive with respect to multi-centennial variations. Different geomagnetic dipole tilt reconstructions agree well for much of the Holocene, but dipole moment estimates still differ substantially. Recent spherical harmonic models for the past 3 and 10 kyrs have improved considerably compared to earlier versions. Nevertheless at present we recommend to test if any interpretation depends on the choice of model.
General Relativity and Gravitation: A Centennial Perspective  [PDF]
Abhay Ashtekar,Beverly K. Berger,James Isenberg,Malcolm A. H. MacCallum
Physics , 2014,
Abstract: To commemorate the 100th anniversary of general relativity, the International Society on General Relativity and Gravitation (ISGRG) commissioned a Centennial Volume, edited by the authors of this article. We jointly wrote introductions to the four Parts of the Volume which are collected here. Our goal is to provide a bird's eye view of the advances that have been made especially during the last 35 years, i.e., since the publication of volumes commemorating Einstein's 100th birthday. The article also serves as a brief preview of the 12 invited chapters that contain in-depth reviews of these advances. The volume will be published by Cambridge University Press and released in June 2015 at a Centennial conference sponsored by ISGRG and the Topical Group of Gravitation of the American Physical Society.
Centennial Oscillations in an Ocean-ice Coupled Model
Jin Xiangze,Huang Ruixin,Yang Jiayan,
Jin Xiangze
,Huang Ruixin,Yang Jiayan

大气科学进展 , 1999,
Abstract: Irregular centennial oscillations, with a spectral peak at 106 years, were obtained from anocean-ice coupled model for the North Atlantic with realistic coastline and bottom topography.The model/s thermohaline circulation is forced by mixed boundary conditions, i.e., a Haney-typel-elaxation condition for temperature, but an equivalent virtual salt flux condition for salinity.Allforcing fields are taken from the observed monthly mean climatological wind stress and buoyancyfluxes.The oscillations appeared in the form of a surface-intensified triPOle in both the sea surfacetemperature and salinity fields located in the vicinity of the Labrador Sea. The oscillations involvea delicate interplay between heat and fresh water advection by meridional overturning circulation,horizontal gyres, vertical convection, and the seasonal cycle. The oscillations al.e primarily controLled by the salinity component of the circulation; however, sea ice plays a minor role in driving theoscillations observed in the model. On the other hand,a regular seasonal cycle in the forcing fieldsis an important ingredient for the centennial oscillations.
The CLAVIUS Four Centennial Meeting and XXXI ESOP  [PDF]
Costantino Sigismondi
Physics , 2011,
Abstract: The XXXI European Symposium on Occultation Projects will be celebrated in ICRANet center of Pescara from 24 to 27 August 2012 (www.icranet.org/clavius2012). The occasion is the fourth centennial of the Jesuit astronomer Christopher Clavius (Bamberg 1538- Napoli 1612). The hybrid eclipse witnessed by Clavius in Rome (1567) and published on his Commentarius on the Sphere (1581 edition) was the first account of an annular eclipse ever published in a scientific book. To account of this eclipse a larger solar diameter for 1567 has to be considered, and the scientific debate is still open. This is the trait-d'union between Clavius and ESOP annual meeting. The city of Pescara and the region of Abruzzo are presented with an historical, climatic, religious and gastronomical outline.
The Vascular Flora of the Oklahoma Centennial Botanical Garden site: Osage County, Oklahoma
Bruce W. Hoagland,Amy Buthod
Oklahoma Native Plant Record , 2007,
Abstract: This paper is a report on the results of an inventory of the vascular plants at the future site of the Oklahoma Centennial Botanical Garden in Osage County, Oklahoma. We collected a total of 293 taxa in 208 genera and 68 families. The families Poaceae and Asteraceae had the greatest number of species with 50 and 44 species respectively. Fortyone species of woody plants were present. Forty-four non-native species were present, representing 15% of the flora. No species tracked by the Oklahoma Natural Heritage Inventory were present.
Nonlinear evolution characteristics of the climate system on the interdecadal-centennial timescale
Gao Xin-Quan,Zhang Wen,
高新全
,张文

中国物理 B , 2005,
Abstract: To better understand the physical mechanism of the climate change on interdecadal-centennial timescale, this paper focuses on analysing and modelling the evolution characteristics of the climate change. The method of wavelet transform is used to pick out the interdecadal timescale oscillations from long-term instrumental observations, natural proxy records, and modelling series. The modelling series derived from the most simplified nonlinear climatic model are used to identify whether modifications are concerned with some forcings such as the solar radiation on the climate system. The results show that two major oscillations exist in various observations and model series, namely the 20--30a and the 60--70a timescale respectively, and these quasi-periodicities are modulated with time. Further, modelling results suggest that the originations of these oscillations are not directly linked with the periodic variation of solar radiations such as the 1-year cycle, the 11-year cycle, and others, but possibly induced by the internal nonlinear effects of the climate system. It seems that the future study on the genesis of the climate change with interdecadal-centennial timescale should focus on the internal nonlinear dynamics in the climate system.
Fire-derived organic carbon turnover in soils on a centennial scale  [PDF]
N. Singh,S. Abiven,M. S. Torn,M. W. I. Schmidt
Biogeosciences Discussions , 2011, DOI: 10.5194/bgd-8-12179-2011
Abstract: Pyrogenic Carbon (PyC), the residue of an incomplete combustion of plant biomass, is considered as a carbon (C) sink due to its assumed stability in soil. Our meta-analysis of studies on PyC degradation challenges the assumption that PyC persist in soil for several thousand years. The turnover time for PyC estimated here ranges from decadal to centennial time scales, and is not slower than decomposition of bulk Soil Organic Matter (SOM) and differs with initial biomass, pyrolysis temperature and climate. Thus, using PyC as a strategy for offsetting carbon emissions requires caution and further research.
A DANE WRITES ABOUT CHOPIN. PEER HULTBERG’S “PRELUDES” AS AN EXAMPLE OF A CONTEMPORARY DANISH BIOGRAPHICAL NOVEL
Joanna Cymbrykiewicz
Studia Humanistyczne (Kraków. 2003) , 2011,
Abstract: The paper A Dane writes about Chopin. Peer Hultberg’s “Preludes” as an example of a contemporary Danish biographical novel concerns the condition of a contemporary Danish biographical novel. The main focus is put on Peer Hultberg’s work Preludes on the famous Polish composer, Fryderyk Chopin. The author of the paper uses the definition of a biographical novel as Maria Jasinska understands it, and the definition of a modernist literary novel by Stephen J. Walton. The article also addresses other contemporary biographical novels written in Scandinavia. Its main aim is to examine in what respects Hultberg’s novel deviates from the standards of a modernist biographical novel. The research is based on four criteria: focus put on one character, chronological structure of the narration, including all life stages, presence of the milestones in the protagonist’s professional career and appearance of authentic characters in the novel’s plot. As it turns out, Preludes hardly fulfills any of the above-mentioned requirements. Although the protagonist is clearly defined, the polyphonic structure of the narration makes it difficult to focus on one character only. The chronological composition is present, but the plot does not include any of the milestones in the composer’s career, since the novel only concerns his childhood. As to authentic characters, they play a peripheral role in the novel’s plot. One can therefore assume that Peer Hultberg’s Preludes is a postmodernist biographical novel, where a fragment replaces the whole, and one stage of life, namely childhood, is capable of telling a story of the origin of genius.
The centennial of the Yellow Fever Commission and the use of informed consent in medical research
Güere?a-Burgue?o,Fernando;
Salud Pública de México , 2002, DOI: 10.1590/S0036-36342002000200009
Abstract: the year 2000 marked the centennial of the discovery of the mode of transmission of yellow fever. informed consent was systematically used for the first time in research. this process was the result of a complex social phenomenon involving the american public health association, the us and spanish governments, american and cuban scientists, the media, and civilian and military volunteers. the public health and medical communities face the aids pandemic at the beginning of the 21st century, as they faced the yellow fever epidemic at the beginning of the 20th century. current medical research dilemmas have fueled the debate about the ethical conduct of research in human subjects. the aids pandemic is imposing enormous new ethical challenges on the conduct of medical research, especially in the developing world. reflecting on the yellow fever experiments of 1900, lessons can be learned and applied to the current ethical challenges faced by the international public health research community.
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