Evaluación de comunidades microbianas edáficas mediante CLPP : estandarización de una técnica de laboratorio para reemplazar microplacas comerciales

129-136Variation of soil-microbial communities are good bioindicators of human impacts in soils, such as different soils management or contamination. Considering that traditional methods of isolation and taxonomic analysis do not consider the functionality of the microbial community, Community-Level Physiological Profiles (CLPP) emerged as a complementary methodology to study microbial communities. Several studies have shown that Biolog® EcoPlates® are very useful for determining physiological differences between communities from different samples. However, commercial microplates have some disadvantages which led us to the idea of replacing them by microplates prepared in the laboratory (Laboratory's). Here, we compared both types of microplates using soil samples from a bioremediation assay. We compared a) the average well color development for each sample, b) the averages of absorbance values for each type of microplate, c) Principal Components, and d) Shannon-Weaver's diversity index (H). Although Laboratory's showed significantly lower Average absorbance values than EcoPlates®, the principal component analysis and diversity index did not differ between types of microplates. In conclusion, both types of microplates showed a relatively similar ability to detect differences in the CLPP of the treatments studied. Consequently, microplates prepared in laboratory are a reliable and economical tool to study the physiology of soil microbial communities

Evaluación de comunidades microbianas edáficas mediante CLPP : estandarización de una técnica de laboratorio para reemplazar microplacas comerciales

129-136Variation of soil-microbial communities are good bioindicators of human impacts in soils, such as different soils management or contamination. Considering that traditional methods of isolation and taxonomic analysis do not consider the functionality of the microbial community, Community-Level Physiological Profiles (CLPP) emerged as a complementary methodology to study microbial communities. Several studies have shown that Biolog® EcoPlates® are very useful for determining physiological differences between communities from different samples. However, commercial microplates have some disadvantages which led us to the idea of replacing them by microplates prepared in the laboratory (Laboratory's). Here, we compared both types of microplates using soil samples from a bioremediation assay. We compared a) the average well color development for each sample, b) the averages of absorbance values for each type of microplate, c) Principal Components, and d) Shannon-Weaver's diversity index (H). Although Laboratory's showed significantly lower Average absorbance values than EcoPlates®, the principal component analysis and diversity index did not differ between types of microplates. In conclusion, both types of microplates showed a relatively similar ability to detect differences in the CLPP of the treatments studied. Consequently, microplates prepared in laboratory are a reliable and economical tool to study the physiology of soil microbial communities

First record of brown long-eared bat Plecotus auritus (Chiroptera: Vespertilionidae) for Sicily island (Italy)

The knowledge of the bat fauna of Sicily (Southern Italy) is scarce, fragmentary or sometimes even confusing. A recent review mentioned 20 species for the region, but it is likely that the checklist of bats of Sicily is still far from being exhaustive. To help fill this gap, in the past few years specific studies were carried out on the distribution of bat species in Sicily, especially in the woodlands of the Nebrodi Mountains. In the municipality of Caronia (Messina province) has captured a young female brown long-eared bat Plecotus auritus (Linneaus, 1758). The capture of P. auritus in Sicily represents the first record of brown long-eared bat Plecotus auritus for Sicily island, an interesting biogeographical record, as this bat is mostly known for the north and centre of the Italian peninsul

Spectral evolution of bright NS LMXBs with INTEGRAL: an application of the thermal plus bulk Comptonization model

The aim of this work is to investigate in a physical and quantitative way the spectral evolution of bright Neutron Star Low-Mass X-ray Binaries (NS LMXBs), with special regard to the transient hard X-ray tails. We analyzed INTEGRAL data for five sources (GX 5-1, GX 349+2, GX 13+1, GX 3+1, GX 9+1) and built broad-band X-ray spectra from JEM-X1 and IBIS/ISGRI data. For each source, X-ray spectra from different states were fitted with the recently proposed model compTB. The spectra have been fit with a two-compTB model. In all cases the first compTB describes the dominant part of the spectrum that we interpret as thermal Comptonization of soft seed photons (< 1 keV), likely from the accretion disk, by a 3-5 keV corona. In all cases, this component does not evolve much in terms of Comptonization efficiency, with the system converging to thermal equilibrium for increasing accretion rate. The second compTB varies more dramatically spanning from bulk plus thermal Comptonization of blackbody seed photons to the blackbody emission alone. These seed photons (R < 12 km, kT_s > 1 keV), likely from the neutron star and the innermost part of the system, the Transition Layer, are Comptonized by matter in a converging flow. The presence and nature of this second compTB component (be it a pure blackbody or Comptonized) are related to the inner local accretion rate which can influence the transient behaviour of the hard tail: high values of accretion rates correspond to an efficient Bulk Comptonization process (bulk parameter delta > 0) while even higher values of accretion rates suppress the Comptonization, resulting in simple blackbody emission (delta=0).Comment: 12 pages, 10 figures, accepted for publication in A&

Molecular characterization of pyridoxine 5′-phosphate oxidase and its pathogenic forms associated with neonatal epileptic encephalopathy

Defects of vitamin B6 metabolism are responsible for severe neurological disorders, such as pyridoxamine 5′-phosphate oxidase deficiency (PNPOD; OMIM: 610090), an autosomal recessive inborn error of metabolism that usually manifests with neonatal-onset severe seizures and subsequent encephalopathy. At present, 27 pathogenic mutations of the gene encoding human PNPO are known, 13 of which are homozygous missense mutations; however, only 3 of them have been characterised with respect to the molecular and functional properties of the variant enzyme forms. Moreover, studies on wild type and variant human PNPOs have so far largely ignored the regulation properties of this enzyme. Here, we present a detailed characterisation of the inhibition mechanism of PNPO by pyridoxal 5′-phosphate (PLP), the reaction product of the enzyme. Our study reveals that human PNPO has an allosteric PLP binding site that plays a crucial role in the enzyme regulation and therefore in the regulation of vitamin B6 metabolism in humans. Furthermore, we have produced, recombinantly expressed and characterised several PNPO pathogenic variants responsible for PNPOD (G118R, R141C, R225H, R116Q/R225H, and X262Q). Such replacements mainly affect the catalytic activity of PNPO and binding of the enzyme substrate and FMN cofactor, leaving the allosteric properties unaltered

Hard X-ray Bursts Recorded by the IBIS Telescope of the INTEGRAL Observatory in 2003-2009

To find X-ray bursts from sources within the field of view of the IBIS/INTEGRAL telescope, we have analysed all the archival data of the telescope available at the time of writing the paper (the observations from January 2003 to April 2009). We have detected 834 hard (15-25 keV) X-ray bursts, 239 of which were simultaneously recorded by the JEM-X/INTEGRAL telescope in the standard X-ray energy range. More than 70% of all bursts (587 events) have been recorded from the well-known X-ray burster GX 354-0. We have found upper limits on the distances to their sources by assuming that the Eddington luminosity limit was reached at the brightness maximum of the brightest bursts.Comment: 18 pages, 2 figures, 2 table

Partially Absorbed Comptonization Spectrum from the Nearly Edge-on Source X 1822-371

We report the results of a spectral analysis over the range 0.1-200 keV performed on the dipping source X 1822-371 observed by BeppoSAX. We find the best fit to the continuum using a partially covered Comptonization model, due to scattering off soft seed photons by electrons at a temperature of ~4.8 keV, without the presence of any soft blackbody emission. The equivalent hydrogen column obtained for the absorbed component is ~4.5 10^{22} cm^{-2}, an order of magnitude larger than the Galactic absorption for this source, and the covering fraction is ~71%. Because the inclination angle of X 1822-371 to the line of sight is ~85^\circ, this model gives a reasonable scenario for the source: the Comptonized spectrum could come from an extended accretion disk corona (ADC), probably the only region that can be directly observed due to the high inclination. The excess of matter producing the partial covering could be close to the equatorial plane of the system, above the outer disk, occulting the emission from the inner disk and the inner part of the ADC. An iron emission line is also present at ~6.5 keV with an equivalent width of ~150 eV. We argue that this strong iron line cannot be explained as reflection of the Comptonized spectrum by the accretion disk. It is probably produced in the ADC. An emission line at ~1.9 keV (with an equivalent width of ~54 eV) and an absorption edge at \~8.7 keV (with an optical depth of ~0.1) are also required to fit this spectrum. These features are probably produced by highly ionized iron (Fe XXIV) present in the outer part of the ADC, where the plasma density is \~10^{11}-10^{12} cm^{-3} and ionized plasma is present.Comment: 15 pages, including 3 figures. Accepted by ApJ. Corrected typos and Figure

Micorrizas arbusculares : Asociaciones simbióticas e indicadores de calidad ambiental en sistemas de cultivos extensivos

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