The blogosphere as an excitable social medium: Richter's and Omori's Law in media coverage

We study the dynamics of public media attention by monitoring the content of online blogs. Social and media events can be traced by the propagation of word frequencies of related keywords. Media events are classified as exogenous - where blogging activity is triggered by an external news item - or endogenous where word frequencies build up within a blogging community without external influences. We show that word occurrences show statistical similarities to earthquakes. The size distribution of media events follows a Gutenberg-Richter law, the dynamics of media attention before and after the media event follows Omori's law. We present further empirical evidence that for media events of endogenous origin the overall public reception of the event is correlated with the behavior of word frequencies at the beginning of the event, and is to a certain degree predictable. These results may imply that the process of opinion formation in a human society might be related to effects known from excitable media.Comment: 4 pages, 4 figure

A Quark Transport Theory to describe Nucleon--Nucleon Collisions

On the basis of the Friedberg-Lee model we formulate a semiclassical transport theory to describe the phase-space evolution of nucleon-nucleon collisions on the quark level. The time evolution is given by a Vlasov-equation for the quark phase-space distribution and a Klein-Gordon equation for the mean-field describing the nucleon as a soliton bag. The Vlasov equation is solved numerically using an extended testparticle method. We test the confinement mechanism and mean-field effects in 1+1 dimensional simulations.Comment: 23 pages, LaTeX (figures available from the authors), UGI-93-

Retrospektive Digitalisierung von Bibliotheksbeständen für eine Verteilte Digitale Forschungsbibliothek : Bericht der Arbeitsgruppe Technik zur Vorbereitung des Programms "Retrospektive Digitalisierung von Bibliotheksbeständen" im Förderbereich "Verteilte Digitale Forschungsbibliothek"

Bericht der Arbeitsgruppe Technik zur Vorbereitung des Programms "Retrospektive Digitalisierung von Bibliotheksbeständen" im Förderbereich "Verteilte Digitale Forschungsbibliothek" Arbeitssitzungen am 14. Mai 1996 (Frankfurt a. M.), 29.-30. Juli 1996 (München), 12.-13. Dezember 1996 (Göttingen) Mitglieder der Arbeitsgruppe: Prof. Dr. Rudolf Bayer, Technische Universität München, Fakultät für Informatik Dr. Jürgen Bunzel, Deutsche Forschungsgemeinschaft, Bonn Dr. Marianne Dörr, Bayerische Staatsbibliothek München Dr. Reinhard Ecker, Beilstein-Institut bzw. ABC Datenservice GmbH, Frankfurt/Main Dipl.-Math. Heinz-Werner Hoffmann, Hochschulbibliothekszentrum NRW, Köln (als Gast für die AG der Verbundsysteme) Dr. Norbert Lossau, Niedersächsische Staats- und Universitätsbibliothek Göttingen (DFG-Projekt ‘Verteilte Digitale Forschungsbibliothek’) Prof. Dr. Elmar Mittler, Niedersächsische Staats- und Universitätsbibliothek Göttingen Dipl.-Inf. Christian Mönch, FB Informatik der J.W. Goethe-Universität Frankfurt Dr. Wilhelm R. Schmidt, Stadt- und Universitätsbibliothek Frankfurt Dr. Hartmut Weber, Landesarchivdirektion, Stuttgar

Dynamics of Entanglement in One-Dimensional Spin Systems

We study the dynamics of quantum correlations in a class of exactly solvable Ising-type models. We analyze in particular the time evolution of initial Bell states created in a fully polarized background and on the ground state. We find that the pairwise entanglement propagates with a velocity proportional to the reduced interaction for all the four Bell states. Singlet-like states are favored during the propagation, in the sense that triplet-like states change their character during the propagation under certain circumstances. Characteristic for the anisotropic models is the instantaneous creation of pairwise entanglement from a fully polarized state; furthermore, the propagation of pairwise entanglement is suppressed in favor of a creation of different types of entanglement. The ``entanglement wave'' evolving from a Bell state on the ground state turns out to be very localized in space-time. Further support to a recently formulated conjecture on entanglement sharing is given.Comment: 25 pages, 21 figures; revte

Mathematics of Gravitational Lensing: Multiple Imaging and Magnification

The mathematical theory of gravitational lensing has revealed many generic and global properties. Beginning with multiple imaging, we review Morse-theoretic image counting formulas and lower bound results, and complex-algebraic upper bounds in the case of single and multiple lens planes. We discuss recent advances in the mathematics of stochastic lensing, discussing a general formula for the global expected number of minimum lensed images as well as asymptotic formulas for the probability densities of the microlensing random time delay functions, random lensing maps, and random shear, and an asymptotic expression for the global expected number of micro-minima. Multiple imaging in optical geometry and a spacetime setting are treated. We review global magnification relation results for model-dependent scenarios and cover recent developments on universal local magnification relations for higher order caustics.Comment: 25 pages, 4 figures. Invited review submitted for special issue of General Relativity and Gravitatio

Implementing complex innovations in fluid multi-stakeholder environments: Experiences of 'telecare'

Accepted versio

The associations among objectively estimated sleep and obesity indicators in elementary schoolchildren

© 2018 Elsevier B.V. Objective: A negative linear association between sleep duration and obesity in children has been reported, but this has been predominantly based on subjective estimates of sleep duration and only one indicator of obesity. This cross-sectional study aimed to examine the relationships among objectively measured sleep parameters and a range of obesity indicators in schoolchildren. Patients/methods: Baseline data were obtained from 335 elementary schoolchildren (aged 7–12 years) recruited to the study. Five indicators of obesity were determined and two global cut-off points (WHO and International Obesity Task Force) were used to define overweight/obesity. Participants wore wrist actigraphy devices (N = 264) for seven consecutive days/nights to objectively estimate six sleep features. Results: Average weekday sleep duration was 7.6 ± 0.7 h and 42.1% of the participants were overweight/obese. After adjustment, those achieving \u3c8 h of sleep had an increased body mass index z-score (β = 0.88, p \u3c 0.001), waist circumference (β = 6.49, p \u3c 0.001), body fat percentage (β = 5.17, p \u3c 0.001), and fat mass (kg) (β = 3.23, p \u3c 0.001) compared to those sleeping ≥8 h. Based on two standardized cut-off points for overweight/obesity, sleeping \u3c8 h was associated with an increased risk of obesity (odds ratio (OR) = 3.75, 95% confidence interval (CI): 1.56–9.05; OR = 4.79 95% CI: 2.11–10.90). Conclusion: Sleep insufficiency, in addition to other lifestyle factors, is likely to play a role in childhood obesity. Lifestyle interventions should include advice regarding sleep improvement with promotion of other healthy lifestyle behaviors to tackle childhood obesity, a serious global public health problem

Hopf algebras and Markov chains: Two examples and a theory

The operation of squaring (coproduct followed by product) in a combinatorial Hopf algebra is shown to induce a Markov chain in natural bases. Chains constructed in this way include widely studied methods of card shuffling, a natural "rock-breaking" process, and Markov chains on simplicial complexes. Many of these chains can be explictly diagonalized using the primitive elements of the algebra and the combinatorics of the free Lie algebra. For card shuffling, this gives an explicit description of the eigenvectors. For rock-breaking, an explicit description of the quasi-stationary distribution and sharp rates to absorption follow.Comment: 51 pages, 17 figures. (Typographical errors corrected. Further fixes will only appear on the version on Amy Pang's website, the arXiv version will not be updated.

Atypical fibroxanthoma with lymphomatoid reaction

Background: Atypical fibroxanthoma (AFX) represents an uncommon skin tumor typically occurring on sun-damaged skin of the elderly. Histopathologic variants include spindled, clear cell, osteoid, osteoclastic, chondroid, pigmented, granular cell and myxoid lesions. To date, an atypical lymphoid infiltrate, including CD30-positive large cells mimicking lymphomatoid papulosis, has not been described in association with AFX. Methods: The clinical and histopathological characteristics of two AFX cases inciting an atypical lymphoid infiltrate, along with immunohistochemical profiles and T-cell receptor gamma ( TCR γ) gene rearrangement results, were reviewed. Results: Lesions in both cases occurred as solitary nodules in elderly patients. Microscopically, both lesions showed a cellular proliferation composed of pleomorphic spindle cells, associated with a prominent intralesional atypical lymphoid infiltrate. The spindle cells expressed CD10 but lacked the expression of S-100, cytokeratins and muscle markers, thereby confirming the diagnosis of AFX. CD30 highlighted a significant subset of large mononuclear cells in the lymphoid infiltrate of one case. TCR γ gene rearrangement analyses were negative for both cases. Conclusion: An atypical lymphoid infiltrate, including the one resembling lymphomatoid papulosis, associated with AFX has not been previously described. It is important to recognize the reactive nature of the infiltrate to avoid a misdiagnosis of lymphoma.Zheng R, Ma L, Bichakjian CK, Lowe L, Fullen DR. Atypical fibroxanthoma with lymphomatoid reaction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79152/1/j.1600-0560.2010.01622.x.pd

Imprisonment and internment: Comparing penal facilities North and South

Recent references to the ‘warehouse prison’ in the United States and the prisión-depósito in Latin America seem to indicate that penal confinement in the western hemisphere has converged on a similar model. However, this article suggests otherwise. It contrasts penal facilities in North America and Latin America in terms of six interrelated aspects: regimentation; surveillance; isolation; supervision; accountability; and formalization. Quantitatively, control in North American penal facilities is assiduous (unceasing, persistent and intrusive), while in Latin America it is perfunctory (sporadic, indifferent and cursory). Qualitatively, North American penal facilities produce imprisonment (which enacts penal intervention through confinement), while in Latin America they produce internment (which enacts penal intervention through release). Closely entwined with this qualitative difference are distinct practices of judicial involvement in sentencing and penal supervision. Those practices, and the cultural and political factors that underpin them, represent an interesting starting point for the explanation of the contrasting nature of imprisonment and internment