41 research outputs found
Does exposure to inflammatory particles modify the pattern of anion in exhaled breath condensate?
Exposure to environmental and occupational particulate matter (PM) induces health effects on the cardio-pulmonary system. In addition, associations between exposure to PM and metabolic syndromes like diabetes mellitus or obesity are now emerging in the literature. Collection of exhaled breath condensate (EBC) is an appealing non-invasive technique to sample pulmonary fluids. This hypothesis-generating study aims to (1) validate an ion chromatography method allowing the robust determination of different metabolism-related molecules (lactate, formate, acetate, propionate, butyrate, pyruvate, nitrite, nitrate) in EBC; (2) apply this method to EBC samples collected from workers exposed to quartz (a known inflammatory particle), to soapstone (a less inflammatory particle than quartz), as well as to controls. A multi-compound standard solution was used to determine the linearity range, detection limit, repeatability and bias from spiked EBC. The biological samples were injected without further treatment into an ion chromatograph with a conductivity detector. RTube <sup>®</sup> were used for field collection of EBC from 11 controls, 55 workers exposed to soapstone and 12 volunteers exposed to quartz dust. The analytical method used proved to be adequate for quantifying eight anions in EBC samples. Its sub-micromolar detection limits and repeatability, combined with a very simple sample preparation, allowed an easy and fast quantification of different glycolysis or nitrosative stress metabolites. Using multivariate discriminant analysis to maximize differences between groups, we observed a different pattern of anions with a higher formate/acetate ratio in the EBC samples for quartz exposed workers compared to the two other groups. We hypothesize that a modification of the metabolic signature could be induced by exposure to inflammatory particles like quartz and might be observed in the EBC via a change in the formate/acetate ratio
Phylogenetic relationships of cone snails endemic to Cabo Verde based on mitochondrial genomes
Background: Due to their great species and ecological diversity as well as their capacity to produce hundreds of different toxins, cone snails are of interest to evolutionary biologists, pharmacologists and amateur naturalists alike. Taxonomic identification of cone snails still relies mostly on the shape, color, and banding patterns of the shell. However, these phenotypic traits are prone to homoplasy. Therefore, the consistent use of genetic data for species delimitation and phylogenetic inference in this apparently hyperdiverse group is largely wanting. Here, we reconstruct the phylogeny of the cones endemic to Cabo Verde archipelago, a well-known radiation of the group, using mitochondrial (mt) genomes. Results: The reconstructed phylogeny grouped the analyzed species into two main clades, one including Kalloconus from West Africa sister to Trovaoconus from Cabo Verde and the other with a paraphyletic Lautoconus due to the sister group relationship of Africonus from Cabo Verde and Lautoconus ventricosus from Mediterranean Sea and neighboring Atlantic Ocean to the exclusion of Lautoconus endemic to Senegal (plus Lautoconus guanche from Mauritania, Morocco, and Canary Islands). Within Trovaoconus, up to three main lineages could be distinguished. The clade of Africonus included four main lineages (named I to IV), each further subdivided into two monophyletic groups. The reconstructed phylogeny allowed inferring the evolution of the radula in the studied lineages as well as biogeographic patterns. The number of cone species endemic to Cabo Verde was revised under the light of sequence divergence data and the inferred phylogenetic relationships. Conclusions: The sequence divergence between continental members of the genus Kalloconus and island endemics ascribed to the genus Trovaoconus is low, prompting for synonymization of the latter. The genus Lautoconus is paraphyletic. Lautoconus ventricosus is the closest living sister group of genus Africonus. Diversification of Africonus was in allopatry due to the direct development nature of their larvae and mainly triggered by eustatic sea level changes during the Miocene-Pliocene. Our study confirms the diversity of cone endemic to Cabo Verde but significantly reduces the number of valid species. Applying a sequence divergence threshold, the number of valid species within the sampled Africonus is reduced to half.Spanish Ministry of Science and Innovation [CGL2013-45211-C2-2-P, CGL2016-75255-C2-1-P, BES-2011-051469, BES-2014-069575, Doctorado Nacional-567]info:eu-repo/semantics/publishedVersio
Analysis of nitrogen oxides (NOx) in the exhaled breath condensate (EBC) of subjects with asthma as a complement to exhaled nitric oxide (FeNO) measurements: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>The study of pulmonary biomarkers with noninvasive methods, such as the analysis of exhaled breath condensate (EBC), provides a useful approach to the pathophysiology of asthma. Although many recent publications have applied such methods, numerous methodological pitfalls remain. The first stage of our study consisted of validating methods for the collection, storage and analysis of EBC; we next sought to clarify the utility of analysing nitrogen oxides (NOx) in the EBC of asthmatics, as a complement to measuring exhaled nitric oxide (FeNO).</p> <p>Methods</p> <p>This hospital-based cross-sectional study included 23 controls matched with 23 asthmatics. EBC and FeNO were performed and respiratory function measured. Intra-assay and intra-subject reproducibility were assessed for the analysis of NOx in the EBC of 10 healthy subjects.</p> <p>Results</p> <p>The intraclass correlation coefficient (ICC) was excellent for intra-assay reproducibility and was moderate for intra-subject reproducibility (Fermanian's classification). NOx was significantly higher in asthmatics (geometric mean [IQR] 14.4 μM [10.4 - 19.7] vs controls 9.9 μM [7.5 - 15.0]), as was FeNO (29.9 ppb [17.9 - 52.4] vs controls 9.6 ppb [8.4 - 14.2]). FeNO also increased significantly with asthma severity.</p> <p>Conclusions</p> <p>We validated the procedures for NOx analysis in EBC and confirmed the need for assays of other biomarkers to further our knowledge of the pathophysiologic processes of asthma and improve its treatment and control.</p
Islands beneath islands: phylogeography of a groundwater amphipod crustacean in the Balearic archipelago
<p>Abstract</p> <p>Background</p> <p>Metacrangonyctidae (Amphipoda, Crustacea) is an enigmatic continental subterranean water family of marine origin (thalassoid). One of the species in the genus, <it>Metacrangonyx longipes</it>, is endemic to the Balearic islands of Mallorca and Menorca (W Mediterranean). It has been suggested that the origin and distribution of thalassoid crustaceans could be explained by one of two alternative hypotheses: (1) active colonization of inland freshwater aquifers by a marine ancestor, followed by an adaptative shift; or (2) passive colonization by stranding of ancestral marine populations in coastal aquifers during marine regressions. A comparison of phylogenies, phylogeographic patterns and age estimations of clades should discriminate in favour of one of these two proposals.</p> <p>Results</p> <p>Phylogenetic relationships within <it>M. longipes </it>based on three mitochondrial DNA (mtDNA) and one nuclear marker revealed five genetically divergent and geographically structured clades. Analyses of cytochrome oxidase subunit 1 (<it>cox1</it>) mtDNA data showed the occurrence of a high geographic population subdivision in both islands, with current gene flow occurring exclusively between sites located in close proximity. Molecular-clock estimations dated the origin of <it>M. longipes </it>previous to about 6 Ma, whereas major cladogenetic events within the species took place between 4.2 and 2.0 Ma.</p> <p>Conclusions</p> <p><it>M. longipes </it>displayed a surprisingly old and highly fragmented population structure, with major episodes of cladogenesis within the species roughly correlating with some of the major marine transgression-regression episodes that affected the region during the last 6 Ma. Eustatic changes (vicariant events) -not active range expansion of marine littoral ancestors colonizing desalinated habitats-explain the phylogeographic pattern observed in <it>M. longipes</it>.</p
Electronic Properties of Vinylene-Linked Heterocyclic Conducting Polymers: Predictive Design and Rational Guidance from DFT Calculations
The band structure and electronic properties in a series of vinylene-linked
heterocyclic conducting polymers are investigated using density functional
theory (DFT). In order to accurately calculate electronic band gaps, we utilize
hybrid functionals with fully periodic boundary conditions to understand the
effect of chemical functionalization on the electronic structure of these
materials. The use of predictive first-principles calculations coupled with
simple chemical arguments highlights the critical role that aromaticity plays
in obtaining a low band gap polymer. Contrary to some approaches which
erroneously attempt to lower the band gap by increasing the aromaticity of the
polymer backbone, we show that being aromatic (or quinoidal) in itself does not
insure a low band gap. Rather, an iterative approach which destabilizes the
ground state of the parent polymer towards the aromatic \leftrightarrow
quinoidal level-crossing on the potential energy surface is a more effective
way of lowering the band gap in these conjugated systems. Our results highlight
the use of predictive calculations guided by rational chemical intuition for
designing low band gap polymers in photovoltaic materials.Comment: Accepted by the Journal of Physical Chemistry
Longidorus poessneckensis Altherr, 1974 and L. piceicola Lišková, Robbins & Brown, 1997 (Nematoda: Longidoridae): new records from Poland and the first description of the L. poessneckensis male and a bivulval female
Impacts of changing climate on the non-indigenous invertebrates in the northern Baltic Sea by end of the twenty-first century
Nematodes associated with plant growth inhibition in the Wielkopolska region
The list of species of the plant parasitic nematodes presented in this paper (133 species belonging to 14 families) is based on the results of faunistic research conducted in the Wielkopolska region by Polish nematologists up until the year 2010, and the results obtained from the project “Elaboration of Innovative Methods for Rapid Identification of Nematodes Causing Damage to the Economy” managed by the Museum and Institute of Zoology of the Polish Academy of Sciences. During the two years of the project (2010-2011) we found 21 species of nematodes which had not yet been reported in the list of species from the Wielkopolska region. Two of them were reported for the first time in Poland
Differential gene regulation underlies variation in melanic plumage coloration in the dark-eyed junco (Junco hyemalis)
Colour plays a prominent role in species recognition; therefore, understanding the proximate basis of pigmentation can provide insight into reproductive isolation and speciation. Colour differences between taxa may be the result of regulatory differences or be caused by mutations in coding regions of the expressed genes. To investigate these two alternatives, we studied the pigment composition and the genetic basis of coloration in two divergent dark‐eyed junco (Junco hyemalis) subspecies, the slate‐coloured and Oregon juncos, which have evolved marked differences in plumage coloration since the Last Glacial Maximum. We used HPLC and light microscopy to investigate pigment composition and deposition in feathers from four body areas. We then used RNA‐seq to compare the relative roles of differential gene expression in developing feathers and sequence divergence in transcribed loci under common‐garden conditions. Junco feathers differed in eumelanin and pheomelanin content and distribution. Within subspecies, in lighter feathers melanin synthesis genes were downregulated (including PMEL, TYR, TYRP1, OCA2 and MLANA), and ASIP was upregulated. Feathers from different body regions also showed differential expression of HOX and WNT genes. Feathers from the same body regions that differed in colour between the two subspecies showed differential expression of ASIP and three other genes (MFSD12, KCNJ13 and HAND2) associated with pigmentation in other taxa. Sequence variation in the expressed genes was not related to colour differences. Our findings support the hypothesis that differential regulation of a few genes can account for marked differences in coloration, a mechanism that may facilitate the rapid phenotypic diversification of juncos.Funding was provided by a grant from the Spanish Ministry of Science and Innovation (CGL‐2011‐25866) to BM.Peer Reviewe