Peeling Back the Layers: Sloughing Esophagitis in a Teenager with Chronic Vomiting.

Esophagitis dissecans superficialis (EsoDS) is a rare condition characterized by the shedding of superficial esophageal epithelium. Limited data exists on EsoDS in the pediatric population. We present a case of a 17-year-old female with chronic nausea and vomiting diagnosed with EsoDS.

Better estimation of protein-DNA interaction parameters improve prediction of functional sites.

Background: Characterizing transcription factor binding motifs is a common bioinformatics task. For transcription factors with variable binding sites, we need to get many suboptimal binding sites in our training dataset to get accurate estimates of free energy penalties for deviating from the consensus DNA sequence. One procedure to do that involves a modified SELEX (Systematic Evolution of Ligands by Exponential Enrichment) method designed to produce many such sequences.

Neural encoding: the brain's representation of space.

Recent studies have shown that a part of the brain makes use of a grid of equilateral triangles to encode the location of the animal within the local environment.

Non-additivity in protein-DNA binding.

Motivation: Localizing protein binding sites within genomic DNA is of considerable importance, but remains difficult for protein families, such as transcription factors, which have loosely defined target sequences. It is generally assumed that protein affinity for DNA involves additive contributions from successive nucleotide pairs within the target sequence. This is not necessarily true, and non-additive effects have already been experimentally demonstrated in a small number of cases.

Application of electrochemical impedance spectroscopy to the study of dioleoyl phosphatidylcholine monolayers on mercury.

Electrochemical impedance spectroscopy has been applied to the analysis of the behavior of monolayers of dioleoyl phosphatidylcholine (DOPC) on a mercury electrode. Experiments were carried out in electrolytes KCl and NaCl (0.1 mol dm(-3)) and Mg(NO3)2 (0.

Optimal path to epigenetic switching.

We use large deviation methods to calculate rates of noise-induced transitions between states in multistable genetic networks. We analyze a synthetic biochemical circuit, the toggle switch, and compare the results to those obtained from a numerical solution of the master equation.

Repression of the yeast HO gene by the MATalpha2 and MATa1 homeodomain proteins.

The HO gene in Saccharomyces cerevisiae is regulated by a large and complex promoter that is similar to promoters in higher order eukaryotes. Within this promoter are 10 potential binding sites for the a1-alpha2 heterodimer, which represses HO and other haploid-specific genes in diploid yeast cells. We have determined that a1-alpha2 binds to these sites with differing affinity, and that while certain strong-affinity sites are crucial for repression of HO, some of the weak-affinity sites are dispensable.

Combined analysis of expression data and transcription factor binding sites in the yeast genome.

Background: The analysis of gene expression using DNA microarrays provides genome wide profiles of the genes controlled by the presence or absence of a specific transcription factor. However, the question arises of whether a change in the level of transcription of a specific gene is caused by the transcription factor acting directly at the promoter of the gene or through regulation of other transcription factors working at the promoter.

Results: To address this problem we have devised a computational method that combines microarray expression and site preference data.