Nucleotide Frequencies in Human Genome and Fibonacci Numbers

This work presents a mathematical model that establishes an interesting connection between nucleotide frequencies in human single-stranded DNA and the famous Fibonacci's numbers. The model relies on two assumptions. First, Chargaff's second parity rule should be valid, and, second, the nucleotide frequencies should approach limit values when the number of bases is sufficiently large. Under these two hypotheses, it is possible to predict the human nucleotide frequencies with accuracy. It is noteworthy, that the predicted values are solutions of an optimization problem, which is commonplace in many nature's phenomena.Comment: 12 pages, 2 figure

An Optimized Data Structure for High Throughput 3D Proteomics Data: mzRTree

As an emerging field, MS-based proteomics still requires software tools for efficiently storing and accessing experimental data. In this work, we focus on the management of LC-MS data, which are typically made available in standard XML-based portable formats. The structures that are currently employed to manage these data can be highly inefficient, especially when dealing with high-throughput profile data. LC-MS datasets are usually accessed through 2D range queries. Optimizing this type of operation could dramatically reduce the complexity of data analysis. We propose a novel data structure for LC-MS datasets, called mzRTree, which embodies a scalable index based on the R-tree data structure. mzRTree can be efficiently created from the XML-based data formats and it is suitable for handling very large datasets. We experimentally show that, on all range queries, mzRTree outperforms other known structures used for LC-MS data, even on those queries these structures are optimized for. Besides, mzRTree is also more space efficient. As a result, mzRTree reduces data analysis computational costs for very large profile datasets.Comment: Paper details: 10 pages, 7 figures, 2 tables. To be published in Journal of Proteomics. Source code available at http://www.dei.unipd.it/mzrtre

Contribution to the knowledge of the family Otoplanidae Hallez, 1892 (Rhabditophora, Proseriata) in the Mediterranean

A growing awareness is rising that present perception of marine biodiversity is inadequate, and based upon unrepresentative data. The inadequacy of knowledge on taxonomy and distribution of marine organisms is particularly acute for interstitial meiofauna, especially for "soft bodied" taxa, which necessitate of observations on both living and fixed specimens. Among these groups, information on Platyhelminthes, a species-rich, ubiquitous and diverse taxon, is at present far from adequate, and is entirely absent for entire biogeographical regions. In this scenario, my research aimed to gather data in the composition and distribution of a family of Platyhelminthes Proseriata, the Otoplanidae Hallez, 1892, in biogeographically significant sectors along the coasts of Mediterranean. The most striking results of a series of sampling campaigns is the great number of new Otoplanidae species found. In this work fifteen new species, belonging to the genus Parotoplana Meixner, 1938 are formally described: P. pythagorae Delogu & Curini-Galletti, 2007; P. spathifera Delogu & Curini-Galletti, 2007; P. terpsichore Delogu & Curini-Galletti, 2007; P. jondelii Delogu & Curini-Galletti, 2007; P. cucullata Delogu et al., 2008; P. fretigaditani Delogu et al., 2008; P. varispinosa Delogu et al., 2008; P. mastigophora Delogu et al., 2008; P. geminispina sp. n., P. crassispina sp. n., P. carthagoensis sp. n., P. ichnusae sp. n., P. pulchrispina sp. n., P. obtusispina sp. n. and P. axii sp. n

A Reproducible Study on Remote Heart Rate Measurement

This paper studies the problem of reproducible research in remote photoplethysmography (rPPG). Most of the work published in this domain is assessed on privately-owned databases, making it difficult to evaluate proposed algorithms in a standard and principled manner. As a consequence, we present a new, publicly available database containing a relatively large number of subjects recorded under two different lighting conditions. Also, three state-of-the-art rPPG algorithms from the literature were selected, implemented and released as open source free software. After a thorough, unbiased experimental evaluation in various settings, it is shown that none of the selected algorithms is precise enough to be used in a real-world scenario

Lead identification and structure-activity relationships of heteroarylpyrazole arylsulfonamides as allosteric CC-chemokine receptor 4 (CCR4) antagonists

A knowledge-based library of aryl 2,3-dichlorophenylsulfonamides was synthesised and screened as human CCR4 antagonists, in order to identify a suitable hit for the start of a lead-optimisation programme. X-ray diffraction studies were used to identify the pyrazole ring as a moiety that could bring about intramolecular hydrogen bonding with the sulfonamide NH and provide a clip or orthogonal conformation that was believed to be the preferred active conformation. Replacement of the core phenyl ring with a pyridine, and replacement of the 2,3-dichlorobenzenesulfonamide with 5- chlorothiophenesulfonamide provided compound 33 which has excellent physicochemical properties and represents a good starting point for a lead optimisation programme. Electronic structure calculations indicated that the preference for the clip or orthogonal conformation found in the small molecule crystal structures of 7 and 14 was in agreement with the order of potency in the biological assay

What do DG categories form?

We introduce a homotopy 2-category structure on the category of 2-categories

Chromosome complement and meiosis in three species of the Neotropical bug genus Antiteuchus (Heteroptera, Pentatomidae, Discocephalinae)

Orcein staining of spermatocytes was used to study the meiotic behavior of holocentric chromosomes in three member of the genus Antiteuchus (commonly known as stink bugs). We describe and illustrate the karyotype of Antiteuchus mixtus, A. sepulcralis and A. macraspis which were cytogenetically characterized as having a diploid number of 2n = 14 and an XY sex chromosome system showing pre-reductional meiosis for autosomes and post-reductional meiosis for sex chromosomes. These species were also shown to have a long diffuse stage during meiotic prophase I and aberrant harlequin-type meiocytes. The chiasma frequency was also analyzed for two of the three species studied.Fil: Lanzone, Cecilia. Universidade Federal de Pernambuco; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: de Souza, Maria José. Universidade Federal de Pernambuco; Brasi