2,652 research outputs found
Phenotypic characteristics of 31 strains of Corynebacterium striatum isolated from clinical samples
During a 34-month period (January 1991 to October 1993), 31 Corynebacterium striatum strains recovered from clinical samples from 24 patients were characterized. Twenty (64%) strains were isolated from wound exudates, 5 (16%) were isolated from bronchial aspirates, 2 (7%) were isolated from urine, 2 (7%) were isolated from endotracheal tubes, 1 (3%) was isolated from a catheter, and 1 (3%) was isolated from empyema. The organisms were identified by conventional culture and phenotypic characterization, the API CORYNE system, and cellular fatty acid composition analyses. The colonies of C. striatum could be confused with those of coagulase-negative staphylococci upon primary isolation from clinical material. A consistent phenotypic pattern was observed: all strains reduced nitrate, hydrolyzed tyrosine, and produced acid from glucose, fructose, and sucrose but not from maltose. API CORYNE profile numbers were 3100105 (28 strains) and 3000105 (3 strains). Susceptibility testing of C. striatum was performed by disk diffusion. All strains were susceptible to both imipenem and vancomycin and resistant to fosfomycin; most strains were susceptible to ampicillin and cephalosporins and resistant to clindamycin, erythromycin, and tetracycline. Performing a Gram stain of fosfomycin-resistant 'Staphylococcus-like' colonies was critical in order to identify C. striatum
Platinum-group elements in the cores of potassium feldspar spherules from the Cretaceous-Tertiary boundary at Caravaca (Spain)
The abundant spherules present in the Cretaceous-Tertiary boundary layer at Caravaca are diagenetically transformed to potassium feldspar. Before our study no possible relicts of the precursor material had been reported. but in this paper we describe the presence of cores in these spherules that could represent a relict of the «unknown precursor». These cores are made up of C mixed with Si. Mg. AL Cr. Ca among other elements. Laser Ablation System analysis also reveals an enrichment in pe;E could suggest an extraterrestrial origin for this material. PI. Pd and Ir do not show a chondritic ratio: however. asevere modification of their concentration could be expected during the early diagenetic processes.Las esférulas existentes en la lámina de sedimento del tránsito Cretácico-Terciario de la sección de Caravaca han sido transformadas diagenéticamente a feldespato potásico. En este trabajo se describe la existencia de núcleos encontrados en el interior de las esférulas. los cuales' pueden representar relictos del material precursor. Dichos núcleos están constituidos por C. Si. Mg, AL Cr y Ca entre otros elementos. Se pone de relieve, por vez primera, su notable enriquecimiento en elementos del grupo del platino, cuyas relaciones no condríticas pueden ser debidas a la existencia de importantes modificaciones en su concentración inicial causadas por los procesos diagenéticos y por la existencia de materia orgánica
Lockdown impact on lifestyle and its association with oral parafunctional habits in a Spanish adolescent population
Aim: To analyse the possible association between decreased physical and social activity
and an increase in the use of mobile devices, internet, and social networks with
increased anxiety and the appearance of oral parafunctions and bruxism for adolescents
before and during COVID-19.
Design: A total of 213 adolescents attended private clinics at two different times:
before lockdown (T0) and after completion of total lockdown (T1). In T0 and T1, a
clinical examination was carried out to assess dental wear (IA) and only in T1 were
they given the self-report
questionnaire which focuses on the periods before and during
lockdown (self-reported
bruxism, state anxiety, mobile phone and internet, social
network use, physical and social activity, and questions on parafunctions).
Results: There were a decrease in physical activity at T0-T1
and an increase in social
media use, internet, state anxiety, and clinical and self-reported
bruxism at T0-T1.
There was a positive correlation between increased self-reported
bruxism, increased
social media use, mobile device use, and state anxiety.
Conclusions: There has been a change in adolescent lifestyle during lockdown with
an increase in the prevalence of oral parafunctions and bruxism. In particular, the
increase in the use of social networks at night and also in anxiety levels during lockdown
were associated with of the increase in self-reported
bruxism
Exploring the intricate evolutionary history of the diploid-polyploid complexVeronica subsection Pentasepalae(Plantaginaceae)
[EN]Veronica subsection Pentasepalae is a diploid–polyploid complex of c. 20 species distributed in Eurasia and North Africa, in which species boundaries are difficult to determine. Here, we present the first comprehensive phylogenetic analysis of V. subsection Pentasepalae based on nucleotide sequences [internal transcribed spacer (ITS) and the plastid trnH-psbA and ycf6-psbM spacers] combined with ploidy estimations. Our results support the monophyly of the subsection. Five well-supported clades are recovered in the ITS sequence analyses, corresponding to broad geographical areas. The causes of the extensive incongruence found between the ITS and plastid DNA datasets, namely incomplete lineage sorting and/or hybridization and polyploidization, are discussed. Most of the diploids traditionally recognized based on morphological characters and one tetraploid are each recovered as monophyletic by the ITS sequence analyses. The Balkan species V. kindlii is resurrected. DNA ploidy level for V. teucrioides is reported here for the first time (2x). Diploid populations have been found for V. orbiculata, which was previously thought to be only tetraploid. Past contact in the amphi-Adriatic area between V. orsiniana and V. orbiculata is suggested. Finally, molecular analyses show that diploid V. jacquinii and diploid V. orbiculata are unrelated. This study contributes to our understanding of the evolutionary history of polyploid complexes, especially those in southern Europe, and highlights the importance of using multiple lines of evidence to investigate species boundaries in such actively diversifying groups
A nomenclatural treatment for Veronica subsect. Pentasepalae (Plantaginaceae sensu APG III) and typification of several names
[EN] The large genus Veronica has a complex evolutionary history. Within it, Veronica subsect. Pentasepalae represents an ideal system to study important evolutionary processes, such as hybridization and polyploidization. Delimitation of species boundaries within the subsection is a difficult task and the highly complicated taxonomy of the group has led to an accumulation of approximately 230 names for 22 accepted taxa. Many names have been used in different taxonomic senses even in recent Floras, scientific works, catalogues, Red Lists and internet resources. The lack of an updated taxonomic and nomenclatural framework represents a significant problem to develop further studies in several fields such as ecology, conservation, plant and evolutionary biology. A complete nomenclatural treatment for the whole subsection is provided here, that relies on results derived from the first phylogenetic analysis of V. subsect. Pentasepalae based on DNA sequence data, morphology and ploidy‐ level information. Nomenclatural types for 22 validly published names are designated. In total 21 lectotypes, 2 epitypes and 1 neotype are chosen. A new combination, Veronica linearis, is proposed
Efficiency of three buffers for extracting β-glucosidase enzyme in different soil orders: Evaluating the role of soil organic matter
The objective of this research was to evaluate extraction methods for β-glucosidases comparing three buffer solutions (MUB, acetate, and maleate) at different incubation times (0.5 h to 10 h) and in three different soil orders (Mollisols, Andisols and Ultisols). Seven acidic soils were evaluated, showing differences in pH, OM, and clay contents. To evaluate the effect of OM as enzymes source, one soil of each order was treated to partially remove its OM and then the enzyme assay was performed. When using MUB and maleate buffers the highest (32 and 31 µg-pNP g-soil-1h-1 in average, respectively) were found, and the latter was significantly (p < 0.050) correlated with the soil clay content. The activity obtained with acetate buffer was much lower (38.2 µg-pNP g-soil-1h-1 in average). The use of MUB buffer with 1 h of incubation is suggested as extraction method, showing good reproducibility and allowing to express higher enzyme potential for soil comparisons. For the Andisol and Ultisol, the enzyme activity significantly decreased with the OM removal (%) indicating that OM is the major source of the measured β-glucosidase activity, while a different trend was observed for the Mollisol, in which the mineral fraction (mainly 2:1 type clay) appears to be involved in the increased enzyme activity displayed after the initial OM removal.The objective of this research was to evaluate extraction methods for β-glucosidases comparing three buffer solutions (MUB, acetate, and maleate) at different incubation times (0.5 h to 10 h) and in three different soil orders (Mollisols, Andisols and Ultisols). Seven acidic soils were evaluated, showing differences in pH, OM, and clay contents. To evaluate the effect of OM as enzymes source, one soil of each order was treated to partially remove its OM and then the enzyme assay was performed. When using MUB and maleate buffers the highest (32 and 31 µg-pNP g-soil-1h-1 in average, respectively) were found, and the latter was significantly (p < 0.050) correlated with the soil clay content. The activity obtained with acetate buffer was much lower (38.2 µg-pNP g-soil-1h-1 in average). The use of MUB buffer with 1 h of incubation is suggested as extraction method, showing good reproducibility and allowing to express higher enzyme potential for soil comparisons. For the Andisol and Ultisol, the enzyme activity significantly decreased with the OM removal (%) indicating that OM is the major source of the measured β-glucosidase activity, while a different trend was observed for the Mollisol, in which the mineral fraction (mainly 2:1 type clay) appears to be involved in the increased enzyme activity displayed after the initial OM removal
Geochemical characterization of the mining district of Linares (Jaen, Spain) by means of XRF and ICP-AES
Linares (Jaen, Spain) has been subjected to an intense mining and metallurgic activity during 2500 years. Basically, lead and silver have been extracted from galena; as well as copper and zinc. Different studies have been conducted to evaluate trace element concentrations to obtain relationships with anthropogenic and geologic factors. The analytical results of these studies have been obtained with ICP-AES. This analytical technique is relatively expensive and inaccessible in zones with scarce economic means. In this study, XRF analyses have been conducted and the obtained results are presented, as well as a comparison with the previously obtained ICP results. In both cases, a cluster analysis has been made to try to identify the same relations in the target area. 5 groups have been identified, mainly related with lithology. Only 10 of the 122 grid squares (each one of 1 km2) are classified in different groups if the cluster analysis is conducted with XRF results or ICP results. ICP classifies better where these grid squares are located, mostly, in contact zones of different lithologies
Integrating Spanish lexical resources by meta-classifiers for polarity classification
In this paper we focus on unsupervised sentiment analysis in Spanish. The lack of resources for languages other than English, as for example Spanish, adds more complexity to the task. However, we take advantage of some good already existing lexical resources. We have carried out several experiments using different unsupervised approaches in order to compare the different methodologies for solving the problem of the Spanish polarity classification in a corpus of movie reviews. Among all these approaches, perhaps the newest one integrates SentiWordNet with the Multilingual Central Repository to tackle polarity detection directly over the Spanish corpus. However, the results obtained were not as promising as we expected, and so we carried out another group of experiments combining all the methods using meta-classifiers. The results obtained with stacking outperformed the individual experiments and encourage us to continue in this way
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