Phase transitions related to the pigeonhole principle

Since Paris introduced them in the late seventies (Paris1978), densities turned out to be useful for studying independence results. Motivated by their simplicity and surprising strength we investigate the combinatorial complexity of two such densities which are strongly related to the pigeonhole principle. The aim is to miniaturise Ramsey's Theorem for $1$-tuples. The first principle uses an unlimited amount of colours, whereas the second has a fixed number of two colours. We show that these principles give rise to Ackermannian growth. After parameterising these statements with respect to a function f:N->N, we investigate for which functions f Ackermannian growth is still preserved

Epidemiological evidence for the association between red and processed meat intake and colorectal cancer

A perspective paper was synthesized during the workshop “How can we approach consensus on the healthiness of red meat?” held in Oslo, Norway, in November 2013 (Oostindjer et al., 2014). The resultant article contains some very interesting information and focuses on the role of red and processed meat in colorectal cancer development. However, not all comments from the co-authors were taken into account in the final manuscript, resulting in a scientifically incorrect statement in the abstract: “Epidemiological and mechanistic data on associations between red and processed meat intake and CRC are inconsistent…”. Because of the high visibility of this abstract through many websites and journals we have to strongly object to that statement

WZW-like Action for Heterotic String Field Theory

We complete the construction of the Neveu-Schwarz sector of heterotic string field theory begun in hep-th/0406212 by giving a closed-form expression for the action and gauge transformations. Just as the Wess-Zumino-Witten (WZW) action for open superstring field theory can be constructed from pure-gauge fields in bosonic open string field theory, our heterotic string field theory action is constructed from pure-gauge fields in bosonic closed string field theory. The construction involves a simple alternative form of the WZW action which is consistent with the algebraic structures of closed string field theory.Comment: 22 pages, no figures, LaTeX2

Surgical excision of post-traumatic myositis ossificans of the adductor longus in a football player

A football player was diagnosed with myositis ossificans of his right adductor longus muscle after an acute injury. Conservative treatment failed and 1 year after the initial trauma the patient underwent surgical excision of a large ossification. Seven months postoperatively, the patient was fully recovered and returned to his preinjury activity levels. We present our approach to this case and discuss our considerations, referring to background information about this rare disease

Layer charge instability in unbalanced bilayer systems in the quantum Hall regime

Measurements in GaAs hole bilayers with unequal layer densities reveal a pronounced magneto-resistance hysteresis at the magnetic field positions where either the majority or minority layer is at Landau level filling factor one. At a fixed field in the hysteretic regions, the resistance exhibits an unusual time dependence, consisting of random, bidirectional jumps followed by slow relaxations. These anomalies are apparently caused by instabilities in the charge distribution of the two layers.Comment: 4 pages, 4 figure

MarkerMiner 1.0: a new application for phylogenetic marker development using angiosperm transcriptomes

Premise of the study: Targeted sequencing using next-generation sequencing (NGS) platforms offers enormous potential for plant systematics by enabling economical acquisition of multilocus data sets that can resolve difficult phylogenetic problems. However, because discovery of single-copy nuclear (SCN) loci from NGS data requires both bioinformatics skills and access to high-performance computing resources, the application of NGS data has been limited. Methods and Results: We developed MarkerMiner 1.0, a fully automated, open-access bioinformatic workflow and application for discovery of SCN loci in angiosperms. Our new tool identified as many as 1993 SCN loci from transcriptomic data sampled as part of four independent test cases representing marker development projects at different phylogenetic scales. Conclusions: MarkerMiner is an easy-to-use and effective tool for discovery of putative SCN loci. It can be run locally or via the Web, and its tabular and alignment outputs facilitate efficient downstream assessments of phylogenetic utility, locus selection, intron-exon boundary prediction, and primer or probe development

Peroneal nerve: normal anatomy and pathologic findings on routine MRI of the knee

Background : Peroneal nerve lesions are not common and are often exclusively assessed clinically and electromyographically. Methods : On a routine MR examination without dedicated MR-neurography sequences the peroneal nerve can readily be assessed. Axial T1-weighted sequences are especially helpful as they allow a good differentiation between the nerve and the surrounding fat. Results : The purpose of this article is to review the normal anatomy and pathologic conditions of the peroneal nerve around the knee. Conclusion : In the first part the variable anatomy of the peroneal nerve around the knee will be emphasized, followed by a discussion of the clinical findings of peroneal neuropathy and general MR signs of denervation. Six anatomical features may predispose to peroneal neuropathy: paucity of epineural tissue, biceps femoris tunnel, bifurcation level, superficial course around the fibula, fibular tunnel and finally the additional nerve branches. In the second part we discuss the different pathologic conditions: accidental and surgical trauma, and intraneural and extraneural compressive lesions. Teaching Points : • Six anatomical features contribute to the vulnerability of the peroneal nerve around the knee. • MR signs of muscle denervation within the anterior compartment are important secondary signs for evaluation of the peroneal nerve. • The most common lesions of the peroneal nerve are traumatic or compressive. • Intraneural ganglia originate from the proximal tibiofibular joint. • Axial T1-weighted images are the best sequence to visualise the peroneal nerve on routine MRI