Differentiation of Bacillus pumilus and Bacillus safensis Using MALDI-TOF-MS

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) despite being increasingly used as a method for microbial identification, still present limitations in which concerns the differentiation of closely related species. Bacillus pumillus and Bacillus safensis, are species of biotechnological and pharmaceutical significance, difficult to differentiate by conventional methodologies. In this study, using a well-characterized collection of B. pumillus and B. safensis isolates, we demonstrated the suitability of MALDI-TOF-MS combined with chemometrics to accurately and rapidly identify them. Moreover, characteristic species-specific ion masses were tentatively assigned, using UniProtKB/Swiss-Prot and UniProtKB/TrEMBL databases and primary literature. Delineation of B. pumilus (ions at m/z 5271 and 6122) and B. safensis (ions at m/z 5288, 5568 and 6413) species were supported by a congruent characteristic protein pattern. Moreover, using a chemometric approach, the score plot created by partial least square discriminant analysis (PLSDA) of mass spectra demonstrated the presence of two individualized clusters, each one enclosing isolates belonging to a species-specific spectral group. The generated pool of species-specific proteins comprised mostly ribosomal and SASPs proteins. Therefore, in B. pumilus the specific ion at m/z 5271 was associated with a small acid-soluble spore protein (SASP O) or with 50S protein L35, whereas in B. safensis specific ions at m/z 5288 and 5568 were associated with SASP J and P, respectively, and an ion at m/z 6413 with 50S protein L32. Thus, the resulting unique protein profile combined with chemometric analysis, proved to be valuable tools for B. pumilus and B. safensis discrimination, allowing their reliable, reproducible and rapid identification.     

Formation of CuInSe2 and CuGaSe2 Thin‐Films Deposited by Three‐Stage Thermal Co‐Evaporation: A Real‐Time X‐Ray Diffraction and Fluorescence Study

Thin film solar cells based on co‐evaporated Cu(In,Ga)Se₂ absorber films present the highest efficiencies among current polycrystalline thin‐film technologies. Thanks to the development of a novel experimental setup for in situ growth studies, it was possible to follow the formation of the crystalline phases during such deposition processes for the first time. This synchrotron‐based energy‐dispersive X‐ray diffraction and fluorescence setup is suited for real‐time studies of thin film vapor deposition processes. Focusing on the growth of CuInSe₂ and CuGaSe₂ fabricated by three‐stage processing, we find that the phase transitions in the Cu‐In‐Se system follow the reported pseudo‐binary In₂Se₃‐Cu₂Se phase diagram. This requires a transformation of the Se sublattice during the incorporation of Cu‐Se into the In₂Se₃ precursor film from the first process stage. In the Cu‐Ga‐Se system, besides an increase in the lattice spacings, we observe no transformation of the Se sublattice. Furthermore, the structural defects of the Ga‐Se precursor film are preserved until the CuGaSe₂ stoichiometry is reached. By means of model calculations of the fluorescence signals, we confirm in both systems the segregation of Cu₂Se at the surface near a concentration of 25 at.% Cu shortly after the recrystallization of the films. The modeling also reveals that Cu₂Se penetrates into the CuInSe₂ film, whereas it remains at the surface of the CuGaSe₂ film.     

Integrative taxonomy reveals too extensive lumping and a new species in the moss genus Amphidium (Bryophyta)

An integrative taxonomic approach, including molecular phylogenetic reconstructions based on plastid rps4-trnF and nuclear ITS sequences, statistical analysis of morphological-anatomical characters, and classical taxonomy, indicates that the reduction of 13 Amphidium species to three in a recent morphological revision represents a case of too extensive lumping. Instead, six Amphidium species can be distinguished based on molecular and morphological data, the widespread Amphidium lapponicum, A. mougeotii, and A. tortuosum, as well as the Macaronesian endemic A. curvipes, the North American endemic A. californicum, and a newly discovered species from Central Asia (southern Siberia and northern Mongolia), A. asiaticum sp. nov. Diagnostic morphological characters for all six species are discussed. The present data confirm that species diversity of Amphidium is highest in the Holarctic, where all six species occur.     

An assessment of gene‐by‐environment interactions in developmental dyslexia‐related phenotypes

While the genetic and environmental contributions to developmental dyslexia (DD) have been studied extensively, the effects of identified genetic risk susceptibility and of specified environmental hazardous factors have usually been investigated separately. We assessed potential gene‐by‐environment (GxE) interactions on DD‐related reading, spelling and memory phenotypes. The presence of GxE effects were investigated for the DYX1C1, DCDC2, KIAA0319 and ROBO1 genes, and for seven specified environmental moderators in 165 nuclear families in which at least one member had DD, by implementing a general test for GxE interaction in sib‐pair‐based association analysis of quantitative traits. Our results support a diathesis‐stress model for both reading and memory composites: GxE effects were found between some specified environmental moderators (i.e. maternal smoke during pregnancy, birth weight and socio‐economic status) and the DYX1C1‐1259C/G marker. We have provided initial evidence that the joint analysis of identified genetic risk susceptibility and measured putative risk factors can be exploited in the study of the etiology of DD and reading‐related neuropsychological phenotypes, and may assist in identifying/preventing the occurrence of DD.     

Contributo all'embriologia delle tamaricaceae

Riassunto

L'Autore stabilisce, con osservazioni effettuate su oltre 4500 ovuli prelevati tutti da una medesima pianta, che lo sviluppo del gametofito femminile in Tamarix gallica L. si effettua secondo i seguenti quattro tipi di costruzione e con le rispettive percentuali di frequenza: 1) tipo Euphorbia dulcis, S-nucleato, 90%; 2) tipo Pyrethrum cierariaefolium 12- e 10-nucleato, 5%; 3) tipo Pyrethrum parthenifolium sottotipo Ulmus 10-nucleato, 3%; 4) tipo Adoxa 8-nucleato, 2%. L'A. mette pure in luce che la triploidia dei nuclei calazali caratteristica dei gametofiti di tipo Euphorbia dulcis può determinarsi nella stessa pianta secondo due distinte modalità: o per un processo di vera e propria cariogamia dei tre nuclei sporiali quiescenti durante lo stadio di polarizzazione 143 con conseguente formazione durante la storia dello sviluppo di uno stadio binucleato secondario, o per coalescenza dei tre fusi calazali durante la terza divisione dello sviluppo.

L'A. stabilisce, con osservazioni effettuate su ca. 1000 ovuli prelevati tutti da una stessa pianta, che lo sviluppo del gametofito femminile di Tamarix africana Poir. si effettua secondo tre tipi di costruzione, con le seguenti percentuali di frequenza: 1) tipo Euphorbia dulcis 8-nucleato, 43%; 2) tipo Pyrethrum cinerariaefolium 12- e 10-nucleato, 47%; 3) tipo Pyrethrum parthenifolium 16- e 14-nucleato, 10%.     

Sulla Terminologia dei Processi Mitotici

Summary

The Author has proposed to establish a general plan for the best known modality of the mitosis discovered in these last years in the higher organism animals and vegetables. Two facts are taken in consideration: the distribution of the chromosomes in the anaphase and the chromosome structure. When the distribution of the chromosomes is unever, the mitosis is called with the phrase “mitosis with irregular distribution” (case of the distribution of the chromosomes non regular between the two poles), or “restitutional mitosis” (case of the forming of the restitution nucleus in metaphase or in the anaphase), or “endorestitutional mitosis” (case of the return of the resting stage before the end of the prophase).

A special case is given when is present the accessory phenomenon of the somatic pairing, in which case the mitosis is called precisely “mitosis with somatic pairing”. The Author regards to the mechanism of the mitosis, observes that the determination of the structure gone beyond the chromatid has not value because the anaphase distributes as a rule whole chromatids. From this point of view the types of chromosomes experimentally observed in an undoubted manner are exactly: monochromosomes, diplochromosomes, polychromosomes, univalents, bivalents, polivalents, diplounivalents and diplobivalents. These two last types of the chromosomes are observed during the first mitosis of the spore, in cases in which the meiosis respectively fails in the interkinesis or before the heterotypic anaphase. The term diplounivalent is originated by the author to distinguish this type of chromosome (that though present in the mitosis is however of meiotic origin) from the other type (the diplochromosome) that has same structure but not of meiotic origin. (The diplochromosome is owing to a supernumerary reproduction of the usual mitotic chromosome).

It is also describes, as far as it can be said accuracy, the course of the different types in metaphase and in anaphase. Keeping thus in mind the chromosome structure (the chromatid is considered as a unity) the mitosis is subdivided in the following types: 1° Mitosis with monochromosomes; 2° Mitosis with diplochromosomes; 3° Mitosis with polychromosomes; 4° Mitosis with diplounivalents; 5° Mitosis with diplobivalents.

The terms proposed considering the chromosome distribution or the chromosome structure can be combinable so that the mitosis with monocromosomes (etc). can be called “restitutional mitosis with monochromosomes” (as for instance in the case of the action of the colchicine), or endorestitutional mitosis with monochromosomes (as for istance in the case of the tapetal cells of Spinacia). Not adding either the term restitutional or endorestitutional, it is understood that the course of the mitosis is regular right up to the end.

In the course of his research the Autor shows a personal explanation for the “later divisions ” in Culex (Berger 1938, Grell 1946) and points out the necessarity of new researches on the mitotic, supramitotic, etc. chromosomes type of Trillium (Matssuura e Haga 1940).     

Sulla Terminologia dei Processi Apomittici

Summary

The Author observing the great disagreement of the terminology usually adopted for the apomictic phenomena, examines the whole series of the phenomena noted both in regards of the formation of the gametophyte and of the embryo. The forming of the gametophyte is fixed on the base of nature of its original cell, normally a haploid spore or »haplospore« (phenomenon of the »haplospory« following the regular meiosis), rarely a diploid spore or »diplospore« (phenomenon of the »diplospory« following the irregular meiosis, as for instance in the case of restitution nucleus, etc.). The original cell can be at least represented by the same cell that usually is the spore mother cell, whether for the outward causes, or for inward causes is lacking the usual reductional process. For the failure of the meiotic process, such a cell cannot be called »spore«.

A cell of the somatic tissue of the sporophyte can even become the original cell of the gametophyte always in case of the absence of the meiosis. These two last cases of apospory are respectively called: »somatic apospory« and »gonial apospory« (= germinal apospory) (Chiarugi 1926).

The formation of the embryo is fixed on the base of the nature of the fecundation. The principal phenomena of the fecundation are represented by the following cases: »amphigamy« (or eugamy, or gamy), »semigamy, »pseudogamy«, »apogamy« »parthenogenesis«. The A. uses the term »apogamy« both for the diploid eggs and for the haploid eggs in which the stimulation of the division is produced by the pollen-tube or by male nuclei, in absence of the gamy.

The term »parthenogenesis« is restricted to the division of the haploid or diploid eggs in which the stimulation is not caused by pollen-tube nor even for the great reason, by the male nuclei existing in it.     

Kinetic-based indexes for the functional evaluation of gait in diplegic children: a preliminary report

Abstract

We evaluated the feasibility of a set of indexes based on ground reaction forces to discriminate between the degree of severity of spastic diplegia, identified via Gross Motor Function Classification System (GMFCS). A stepwise discriminant ordinal regression analysis performed on a sample of 58 children returned a subset of variables related to the ratio between braking and propulsive vertical forces and anteroposterior timings. Rather, parameters concerning bilateral symmetry were poorly discriminating. The relative simplicity of the selected indexes allows for their easy implementation on existing gait analysis applications for screening purposes.     

Xanthine Oxidase Inhibition by 1,3-dipropyl-8-sulfophenyl-xanthine (DPSPX), an Antagonist of Adenosine Receptors

Xanthine oxidase (XO), an enzyme involved in purine metabolism, is a source of either oxidants (superoxide radical) or antioxidants (uric acid). Interference with XO activity can lead to oxidative stress, thus contributing to the pathogenesis of cardiovascular diseases. The adenosine receptors antagonist, 1,3-dipropyl-8-sulfophenylxanthine (DPSPX), induces hypertension and cardiovascular injury in rats. Since DPSPX is a xanthine, we aimed at evaluating DPSPX's influence on XO activity to ascertain its contribution to DPSPX-induced hypertension. The activity of isolated XO in the presence of DPSPX was evaluated spectrophotometrically. Serum and urinary uric acid levels of DPSPX-treated rats were measured using a commercial kit. DPSPX inhibited XO activity in a concentration-dependent manner and reduced rat serum and urinary uric acid levels. It can be concluded that: DPSPX is an inhibitor of XO; decreased generation of uric acid may lead to oxidative stress, thus contributing to endothelial dysfunction and vascular morphological changes in DPSPX-treated rats.