Pre-cut dried blood spot (PCDBS): an alternative to dried blood spot (DBS) technique to overcome hematocrit impact

Quantification of analytes by Dried Blood Spots (DBS) on different paper cards has been extensively reported in the past several years. However, some factors limit the robustness of the precision and accuracy of DBS such as: hematocrit level, blood viscosity, analyte nature, spotting technique and spotting conditions. As such, the paper material used for DBS must meet strict quality control criteria to produce reliable quantification of drugs: uniformity, no chemical leaching and no chromatographic effect. To overcome these variables, especially the hematocrit impact, a modification of the traditional DBS, named Pre-Cut Dried Blood Spot (PCDBS), is presented. In contrast to the classical DBS technique, the new PCDBS procedure demonstrates no variation in response, within ±3%, independently of the hematocrit level or of the type of card used. The impact of the hematocrit level on the analyte recovery is discussed for both DBS and PCDBS approaches. Moreover, for quantification of naproxen by liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS), the PCDBS technique was demonstrated to be as precise (%CV ≤3.1%) and accurate (%nominal between 95.4 and 104.4%) as the classical DBS procedure.     

Gene teams: a new formalization of gene clusters for comparative genomics

This paper describes an efficient algorithm based on a new concept called gene team for detecting conserved gene clusters among an arbitrary number of chromosomes. Within the clusters, neither the order of the genes nor their orientation need be conserved. In addition, insertion of foreign genes within the clusters are permitted to a user-defined extent. This algorithm has been implemented in a publicly available TEAM software that proves to be an efficient tool for systematic searches of conserved gene clusters. Examples of actual biological results are provided. The software is downloadable from http://www-igm.univ-mlv.fr/ approximately raffinot/geneteam.html.     

Are the Weyl and coherent state descriptions physically equivalent?

We investigate the consistency of coherent state quantization in regard to physical observations in the non-relativistic (or Galilean) regime. We compare this particular type of quantization of the complex plane with the canonical (Weyl) quantization and examine whether they are or not equivalent in their predictions. As far as only usual dynamical observables (position, momentum, energy, …) are concerned, the quantization through coherent states is proved to be a perfectly valid alternative. We successfully put to the test the validity of CS quantization in the case of data obtained from vibrational spectroscopy.     

Combinatorial Hopf Algebras and Towers of Algebras—Dimension, Quantization and Functorality

Bergeron and Li have introduced a set of axioms which guarantee that the Grothendieck groups of a tower of algebras $\bigoplus_{n\ge0}A_n$ can be a pair of graded dual Hopf algebras. Hivert and Nzeutchap, and independently Lam and Shimozono constructed dual graded graphs from primitive elements in Hopf algebras. In this paper we apply the composition of these constructions to towers of algebras. We show that if a tower $\bigoplus_{n\ge0}A_n$ gives rise to a pair of graded dual Hopf algebras, then $\dim(A_n)=r^nn!$ where $r = \dim(A_1)$ . In the case of r?=?1 we give a conjectural classification. We then investigate a quantum version of the main theorem. We conclude with some open problems and a categorification of these constructions.     

Near-UV induced interstrand cross-links in anthraquinone-DNA duplexes

Anthraquinone (AQ) has been extensively used as a photosensitizer to study charge transfer in DNA. Near-UV photolysis of AQ induces electron abstraction in oligonucleotides leading to AQ radical anions and base radical cations. In general, this reaction is followed by the transport of base radical cations to sites of low oxidation potential, that is, GG, and conversion of G radical cations to DNA breaks. Here, we show that AQ also produces interstrand cross-links in DNA duplexes. About half of the cross-links collapse to single strands in hot piperidine treatment. The structure of stable interstrand cross-links was deduced by MS, NMR, and sequence substitution. The cross-links consist of a covalent link between the methyl group of T on one strand with either C6 or C7 of AQ on the other strand. The formation of interstrand cross-links decreased in O2 compared to deoxygenated solutions. In the presence of O2, the yield of breaks at GG doublets was 10-fold greater than that of cross-links for end tethered AQ, while cross-links exceeded breaks for centrally located AQ. The formation of stable cross-links can be explained by initial charge transfer from T to excited AQ, deprotonation of T radical cations, and condensation of the latter species with AQ radicals. These studies reveal a novel pathway of damage in the photolysis of AQ-DNA duplexes.     

Modified one-body memory function for classical fluids

A microscopic theory applicable to simple classical fluids, particularly in the hydrodynamic regime, is presented. A simple isomorphic transformation of the space of one-body additive phase-space functions is considered whose distinguishing feature is that the total energy density is contained in the new space. A projection operator formalism for this subspace has certain desirable properties for the study of the hydrodynamic regime. It is shown that, for a broad class of approximations, one obtains a prediction for the VanHove structure factorS(k, ω) that has the correct hydrodynamic structure and in which the only quantities that are approximated are the dissipative transport coefficients; all thermodynamic quantities appearing in the expression are rendered exactly. In particular, a weak coupling approximation is made on the memory function, and results are compared with the analogous theory of Forster and Martin. Agreement is found for the dissipative transport coefficients to lowest nontrivial order in the coupling. On the other hand, thermodynamic quantities are accurately predicted only to second order by Forster and Martin, whereas in the present theory they are exact.     

Approximate solutions of the Liouville equation. IV. The two-body additive approximation

The two-body additive approximation on the time-dependent Liouville distribution, first introduced in part I of this series, is put into the conventional form of a self-contained kinetic equation for the doublet distribution. From this point of view the approximation consists in truncating the BBGKY chain by expressing the triplet distribution as a functional of lower distributions at the same value of the time variable. To accomplish this, it is necessary to study two associated purely spatial integral equations. The doublet kinetic equation can then be written in terms of solutions of these integral equations and comparison with conventional methods of truncating the BBGKY chain can then be made. For the purpose of comparison a method of truncating the chain based on the Kirkwood superposition approximation is introduced and discussed briefly. The momentum structure of the resulting doublet kinetic equation is similar, but the nonlocality in space of our truncation introduces distinct differences in the spatial structure. The inconsistency between conventional truncations and the exact initial conditions used for the calculation of time-dependent correlation functions is pointed out. This inconsistency is not shared by the two-body additive approximation.