BibSonomy publications for /user/a_olympiaSat May 09 21:38:26 CEST 2009WiesbadenWeb 2.0 - Eine empirische Bestandsaufnahme53-72Wer bloggt was? Eine Analyse der deutschen Top 100-Blogs mit Hilfe von Cluster-Verfahren2008blog software Sat May 09 21:24:38 CEST 2009cite arxiv:0811.3302
Comment: 20 pages, 6 figures, submitted for publicationThe first digit frequencies of primes and Riemann zeta zeros tend to
uniformity following a size-dependent generalized Benford's law2008imported Prime numbers seem to distribute among the natural numbers with no other law
than that of chance, however its global distribution presents a quite
remarkable smoothness. Such interplay between randomness and regularity has
motivated sci- entists of all ages to search for local and global patterns in
this distribution that eventually could shed light into the ultimate nature of
primes. In this work we show that a generalization of the well known
first-digit Benford's law, which addresses the rate of appearance of a given
leading digit d in data sets, describes with astonishing precision the
statistical distribution of leading digits in the prime numbers sequence.
Moreover, a reciprocal version of this pattern also takes place in the sequence
of the nontrivial Riemann zeta zeros. We prove that the prime number theorem
is, in the last analysis, the responsible of these patterns. Some new relations
concerning the prime numbers distribution are also deduced, including a new
approximation to the counting function pi(n). Furthermore, some relations
concerning the statistical conformance to this generalized Benford's law are
derived. Some applications are finally discussed.
Sat May 02 17:41:41 CEST 2009cite arxiv:0804.2273
Object Re-Use & Exchange: A Resource-Centric Approach2008imported The OAI Object Reuse and Exchange (OAI-ORE) framework recasts the
repository-centric notion of digital object to a bounded aggregation of Web
resources. In this manner, digital library content is more integrated with the
Web architecture, and thereby more accessible to Web applications and clients.
This generalized notion of an aggregation that is independent of repository
containment conforms more closely with notions in eScience and eScholarship,
where content is distributed across multiple services and databases. We provide
a motivation for the OAI-ORE project, review previous interoperability efforts,
describe draft ORE specifications and report on promising results from early
experimentation that illustrate improved interoperability and reuse of digital
objects.
Fri Mar 20 19:37:00 CET 2009cite arxiv:cs/0612043
Comment: 15 pages, LaTeX, 1 figure, Proc. 10th Int'nl Conf. Principles Of
Distributed Systems (OPODIS), Lecture Notes in Computer Science, Vol. 4305,
Springer Verlag, Berlin, 2006, 290--305About the Lifespan of Peer to Peer Networks2006imported We analyze the ability of peer to peer networks to deliver a complete file
among the peers. Early on we motivate a broad generalization of network
behavior organizing it into one of two successive phases. According to this
view the network has two main states: first centralized - few sources (roots)
hold the complete file, and next distributed - peers hold some parts (chunks)
of the file such that the entire network has the whole file, but no individual
has it. In the distributed state we study two scenarios, first, when the peers
are ``patient'', i.e, do not leave the system until they obtain the complete
file; second, peers are ``impatient'' and almost always leave the network
before obtaining the complete file.
Tue Jan 13 07:01:21 CET 2009New York{SIGIR'03}: Proceedings of the 26th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval41-47Quantitavie Evaluation of Passage Retrieval Algorithms for Question Answering2003algorthmus Sat Jan 03 15:09:36 CET 2009cite arxiv:astro-ph/0212375
Comment: 19 pages, revised following referee's report, and accepted by MNRAS.
Higher resolution Figures, an animated version of Figure 12 and a colour
version of Figure 22 are available from http://www.nottingham.ac.uk/~ppxeh/The 2dF Galaxy Redshift Survey: correlation functions, peculiar
velocities and the matter density of the Universe2002arxiv dark matter We present a detailed analysis of the two-point correlation function, from
the 2dF Galaxy Redshift Survey (2dFGRS). We estimate the redshift-space
correlation function, xi(s), from which we measure the redshift-space
clustering length, s_0=6.82+/-0.28 Mpc/h. We also estimate the projected
correlation function, Xi(sigma), and the real-space correlation function,
xi(r), which can be fit by a power-law, with r_0=5.05+/-0.26Mpc/h,
gamma_r=1.67+/-0.03. For r>20Mpc/h, xi drops below a power-law as is expected
in the popular LCDM model. The ratio of amplitudes of the real and
redshift-space correlation functions on scales of 8-30Mpc/h gives an estimate
of the redshift-space distortion parameter beta. The quadrupole moment of xi on
scales 30-40Mpc/h provides another estimate of beta. We also estimate the
distribution function of pairwise peculiar velocities, f(v), including
rigorously the effect of infall velocities, and find that it is well fit by an
exponential. The accuracy of our xi measurement is sufficient to constrain a
model, which simultaneously fits the shape and amplitude of xi(r) and the two
redshift-space distortion effects parameterized by beta and velocity
dispersion, a. We find beta=0.49+/-0.09 and a=506+/-52km/s, though the best fit
values are strongly correlated. We measure the variation of the peculiar
velocity dispersion with projected separation, a(sigma), and find that the
shape is consistent with models and simulations. Using the constraints on bias
from recent estimates, and taking account of redshift evolution, we conclude
that beta(L=L*,z=0)=0.47+/-0.08, and that the present day matter density of the
Universe is 0.3, consistent with other 2dFGRS estimates and independent
analyses.
Sat Dec 27 11:36:01 CET 2008HeidelbergAdvances in Information Retrieval, 30th European Conference on IR Research, ECIR 2008101-113LNAIA Comparison of Social Bookmarking with Traditional Search49562008tagging Social bookmarking systems allow users to store links to internet resources on a web page. As social bookmarking systems are growing in popularity, search algorithms have been developed that transfer the idea of link-based rankings in the Web to a social bookmarking system’s
data structure. These rankings differ from traditional search engine rankings in that they incorporate the rating of users.
In this study, we compare search in social bookmarking systems with traditionalWeb search. In the first part, we compare the user activity and behaviour in both kinds of systems, as well as the overlap of the underlying sets of URLs. In the second part,we compare graph-based and vector space rankings for social bookmarking systems with commercial search engine rankings.
Our experiments are performed on data of the social bookmarking system Del.icio.us and on rankings and log data from Google, MSN, and AOL. We will show that part of the difference between the systems is due to different behaviour (e. g., the concatenation of multi-word lexems
to single terms in Del.icio.us), and that real-world events may trigger similar behaviour in both kinds of systems. We will also show that a graph-based ranking approach on folksonomies yields results that are closer to the rankings of the commercial search engines than vector space
retrieval, and that the correlation is high in particular for the domains that are well covered by the social bookmarking system.Tue Nov 18 09:56:22 CET 2008D-Lib MagazineNovember/December 11/12Social Annotations in Digital Library Collections142008Annotations Collections Digital Library Social in Thu Oct 30 12:11:30 CET 2008VIII, 216 S.Quellen und Studien zur Geschichte des Deutschen Ordens ; 37Hochmeister Hermann von Salza und Kaiser Friedrich II.1987Salza Tue Oct 28 11:20:05 CET 2008Indianapolis, INProfessional VMware Server2007Server professional vmware Sat Jul 12 18:16:45 CEST 2008Ann Univ Mariae Curie Sklodowska [Med]252-6High doses of atorvastatin (Sortis) modify the secretory process in the exocrine portion of the pancreas.592004Atorvastatin Changes were observed in the ultrastructure of the pancreatic acinar cells in rats after administration of atorvastatin (Sortis) in the therapeutic and ten times larger dose for the period of 6 weeks. It was found that atorvastatin given to rats in the therapeutic dose (80 mg/day) stimulated the secretion in pancreocytes, whereas the ten times higher dose of atorvastatin distorts the complicated process of the release of the secretion from the cell.Sat Jul 12 18:16:45 CEST 2008Am J CardiolJul112-8Effect of Intensive Atorvastatin Therapy on Prostaglandin E(2) Levels and Metalloproteinase-9 Activity in the Plasma of Patients With Non-ST-Elevation Acute Coronary Syndrome.1022008Atorvastatin Inflammation plays a pivotal role in the pathophysiology of non-ST elevation acute coronary syndromes (NSTEACS). Intensive statin therapy reduces the recurrence of cardiovascular events after acute coronary syndromes. The aim of this study was to examine nuclear factor-kappaB activity in peripheral blood mononuclear cells, prostaglandin E(2) (PGE(2)) and leukotriene B(4) levels, and matrix metalloproteinase-9 (MMP-9) activity in plasma from patients with NSTEACS (at 0 days, 4 days, 2 months, and 6 months), patients with stable coronary artery disease, and healthy controls. On day 4, patients with NSTEACS were randomized to receive atorvastatin 80 mg/day (n = 14) or standard treatment (n = 16) during 2 months to study its effect on these parameters. Nuclear factor-kappaB activity (by electrophoretic mobility shift assay), PGE(2) levels (by enzyme-linked immunosorbent assay), and MMP-9 activity (by gelatin zymography) in the plasma of patients with NSTEACS were significantly increased compared with patients with coronary artery disease and healthy controls. At 6 months, MMP-9 activity was normalized, whereas nuclear factor-kappaB activity and PGE(2) levels were still increased. Leukotriene B(4) plasma levels (by enzyme-linked immunosorbent assay) were similar in patients with NSTEACS and those with coronary artery disease but were significantly higher than those of healthy subjects. There was a significant correlation between plasma PGE(2) levels and MMP-9 activity in patients with NSTEACS (r = 0.754, p <0.01). Atorvastatin 80 mg/day reduced circulating PGE(2) levels (median 222.4 [interquartile range 157.4 to 253.5] vs 550.8 [276.9 to 613.0] pg/ml, p = 0.006) and MMP-9 activity (0.0025 [0.0017 to 0.0035] vs 0.0280 [0.0057 to 0.0712] arbitrary units, p = 0.03). In conclusion, nuclear factor-kappaB activity in peripheral blood mononuclear cells, and plasma PGE(2) levels and MMP-9 activity, increase during NSTEACS. Atorvastatin 80 mg/day normalizes PGE(2) levels and MMP-9 activity, providing additional mechanisms by which intensive atorvastatin therapy may reduce the incidence of cardiovascular events.Sat Jul 12 09:50:45 CEST 2008HypertensionJun61281-6Different effect of antihypertensive drugs on conduit artery endothelial function.412003Hypertonie To compare the effect of antihypertensive drugs on endothelium-dependent vasodilation in the peripheral conduit arteries of patients with essential hypertension, in a prospective, randomized, parallel group study, endothelial function was assessed in 168 hypertensive patients before and after 6-month treatment with randomly assigned nifedipine GITS (30 to 60 mg, n=28), amlodipine (5 to 10 mg, n=28), atenolol (50 to 100 mg, n=29), nebivolol (5 to 10 mg, n=28), telmisartan (80 to 160 mg, n=29), and perindopril (2 to 4 mg, n=28). If necessary, hydrochlorothiazide (25 mg) was added to each compound. We evaluated brachial artery flow-mediated, endothelium-dependent dilation (high-resolution ultrasound) compared with endothelium-independent response to glyceryl trinitrate (25 microg/s). Brachial artery diameter was measured by automatic computerized analysis. Forty healthy subjects were evaluated as a control group. Oxidative stress production was evaluated by measuring plasma malondialdehyde and plasma lipoperoxides; plasma antioxidant capacity was assessed as ferric-reducing antioxidant power. Hypertensive patients showed a significantly (P<0.01) lower flow-mediated dilation (5.2+/-1.9%) as compared with healthy control subjects (7.1+/-2.6%). Response to glyceryl trinitrate was similar in control subjects and patients. At baseline, blood pressure, diameter, flow-mediated dilation, and response to glyceryl trinitrate were similar in the different treatment groups. All treatments similarly reduced blood pressure, but only perindopril increased flow mediated dilation (from 5.1+/-2 to 6.4+/-2.4%; P<0.01) without modifying the response to glyceryl trinitrate. Perindopril but also telmisartan nifedipine and amlodipine reduced oxidative stress and increased plasma antioxidant capacity. In patients with essential hypertension, ACE inhibitors appear to be the only compounds able to improve conduit artery endothelium-dependent vasodilation.Sat Jul 12 09:50:45 CEST 2008HypertensionMay5993-1002Identification of telmisartan as a unique angiotensin II receptor antagonist with selective PPARgamma-modulating activity.432004Bluthochdruck The metabolic syndrome is a common precursor of cardiovascular disease and type 2 diabetes that is characterized by the clustering of insulin resistance, dyslipidemia, and increased blood pressure. In humans, mutations in the peroxisome proliferator-activated receptor-gamma (PPARgamma) have been reported to cause the full-blown metabolic syndrome, and drugs that activate PPARgamma have proven to be effective agents for the prevention and treatment of insulin resistance and type 2 diabetes. Here we report that telmisartan, a structurally unique angiotensin II receptor antagonist used for the treatment of hypertension, can function as a partial agonist of PPARgamma; influence the expression of PPARgamma target genes involved in carbohydrate and lipid metabolism; and reduce glucose, insulin, and triglyceride levels in rats fed a high-fat, high-carbohydrate diet. None of the other commercially available angiotensin II receptor antagonists appeared to activate PPARgamma when tested at concentrations typically achieved in plasma with conventional oral dosing. In contrast to ordinary antihypertensive and antidiabetic agents, molecules that can simultaneously block the angiotensin II receptor and activate PPARgamma have the potential to treat both hemodynamic and biochemical features of the metabolic syndrome and could provide unique opportunities for the prevention and treatment of diabetes and cardiovascular disease in high-risk populations.Sat Jul 12 09:50:45 CEST 2008HypertensionJulComparison of the Efficacy of Morning Versus Evening Administration of Telmisartan in Essential Hypertension.2007Micardis Valsartan administration at bedtime as opposed to on wakening improves the sleep time-relative blood pressure decline toward a more dipper pattern without loss in 24-hour efficacy. Yet to be determined is whether this administration time-dependent efficacy is a class-related feature, characteristic of all angiotensin receptor blockers or specific only to valsartan. Terminal half-life is a major difference between angiotensin receptor blockers, being largest ( approximately 24 hours) for telmisartan. This trial investigated the administration time-dependent antihypertensive efficacy of telmisartan. We studied 215 patients with hypertension (114 men and 101 women), 46.4+/-12.0 years of age, randomly assigned to receive telmisartan (80 mg/d) as a monotherapy either on awakening or at bedtime. Blood pressure was measured for 48 hours before and after 12 weeks of treatment. The significant blood pressure reduction after treatment was similar for both groups. Bedtime administration of telmisartan, however, was more efficient than morning dosing in reducing the nocturnal blood pressure mean. The sleep time-relative blood pressure decline was slightly reduced after telmisartan on awakening but significantly increased with bedtime dosing, thus reducing the prevalence of nondipping from baseline by 76%. Telmisartan administered at bedtime, as opposed to morning dosing, improved the sleep time-relative blood pressure decline toward a more dipper pattern without loss in 24-hour efficacy. Nocturnal BP regulation is significantly better achieved with bedtime dosing of telmisartan. Results from this prospective trial suggest that these beneficial features of bedtime dosing may be class related for angiotensin receptor blockers. These results should be taken into account when prescribing this class of antihypertensive medication for treatment of essential hypertension.Wed Jun 25 06:25:58 CEST 2008New Yorkninth Dover printing, tenth GPO printingHandbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables1964Handbook Mon Sep 17 21:43:48 CEST 2007BioinformaticsSepii79--85The fragment assembly string graph21 Suppl 22005graph string We present a concept and formalism, the string graph, which represents all that is inferable about a DNA sequence from a collection of shotgun sequencing reads collected from it. We give time and space efficient algorithms for constructing a string graph given the collection of overlaps between the reads and, in particular, present a novel linear expected time algorithm for transitive reduction in this context. The result demonstrates that the decomposition of reads into kmers employed in the de Bruijn graph approach described earlier is not essential, and exposes its close connection to the unitig approach we developed at Celera. This paper is a preliminary piece giving the basic algorithm and results that demonstrate the efficiency and scalability of the method. These ideas are being used to build a next-generation whole genome assembler called BOA (Berkeley Open Assembler) that will easily scale to mammalian genomes.Wed Sep 12 23:04:22 CEST 2007Edinburgh, ScotlandProceedings of the Collaborative Web Tagging Workshop at the WWW 2006MayTowards the Semantic Web: Collaborative Tag Suggestions2006Collaborative Semantic collaborative semantic suggestions web Content organization over the Internet went through several interesting phases of evolution: from structured directories to unstructured Web search engines and more recently, to tagging as a way for aggregating information, a step towards the semantic web vision. Tagging allows ranking and data organization to directly utilize inputs from end users, enabling machine processing of Web content. Since tags are created by individual users in a free form, one important problem facing tagging is to identify most appropriate tags, while eliminating noise and spam. For this purpose, we define a set of general criteria for a good tagging system. These criteria include high coverage of multiple facets to ensure good recall, least effort to reduce the cost involved in browsing, and high popularity to ensure tag quality. We propose a collaborative tag suggestion algorithm using these criteria to spot high-quality tags. The proposed algorithm employs a goodness measure for tags derived from collective user authorities to combat spam. The goodness measure is iteratively adjusted by a reward-penalty algorithm, which also incorporates other sources of tags, e.g., content-based auto-generated tags. Our experiments based on My Web 2.0 show that the algorithm is effective.Sat Sep 08 11:56:08 CEST 2007Lecture Notes of the {STOP} 1992 {S}ummerschool on {C}onstructive {A}lgorithmicsSeptember1--72 of Part 1A Gentle Introduction to Category Theory --- the calculational approach1992imported Tue Sep 04 21:40:06 CEST 2007PaperbackAprilWelches Wissen brauchen Lehrer? Lehrerbildung aus dem Blickwinkel der Pädagogik.2002Wissen lehrerbildung tools wissen