Waldemar Berchtold

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BACKGROUND Diagnosis and management of idiopathic thrombocytopenic purpura (ITP) have been based primarily on expert opinion and practice guidelines rather than on evidence. We have used a registry to prospectively survey the presenting features and the diagnostic evaluation and management practices used for children with ITP worldwide. METHODS We used(More)
The aim of this study was to retrospectively assess the prognostic value of p53 and bcl-2 protein expression, cell proliferation index (Mib-1 index), and tumor microvessel density (factor VIII-related antigen) in pediatric medulloblastoma patients. Tumor specimens of 55 patients (age 2-18 years) with medulloblastoma treated with a curative intent between(More)
This paper proposes a novel digital watermarking algorithm for 3D mesh models that, while developed with focus on video games, operates on a generalized mesh model representation. It combines spectral mesh compression with modifications of the vertex norm distribution in the spatial domain. Furthermore, it uses an optimizer based on evolutionary strategies(More)
To trace back copyright infringements, digital transaction watermarking today is a widely accepted method. Here, copies of a single work are individualized by embedding userspecific watermark messages. However, transaction watermarking is vulnerable to collusion attacks, where multiple individualized copies of one work are compared and/or combined to attack(More)
Today digital transaction watermarking is a widely accepted mechanism in multimedia security. Copies of one work are distributed with individual watermarks. One major threat on transaction watermarking are collusion attacks. Multiple individualized copies of the work are mixed to produce a counterfeited or undetectable watermark. As a countermeasure(More)
In a randomised, multicentre study intravenous IgG was compared with oral corticosteroids in 108 children with untreated acute immune thrombocytopenic purpura. IgG was an efficient treatment with no severe untoward reactions. The effects of corticosteroids and IgG were identical for rapid responders, who accounted for 62% of all patients. In contrast,(More)
Fingerprinting codes are mechanisms to increase the security of transaction watermarking. Digital transaction watermarking is an accepted mechanism to discourage illegal distribution of multimedia. Here copies of the same content are distributed with individual markings. Simple but effective attacks on transaction watermarking are collusion attacks where(More)
Digital transaction watermarking today is a widely accepted mechanism in multimedia security. Here, copies of one work are distributed with individual markings. One major threat on transaction watermarking are collusion attacks. Here multiple individualized copies of the work are mixed in order to create a counterfeited or undetectable watermark. One(More)