2,224 research outputs found
Phylogenetic analysis of rhodolith formation in the Corallinales (Rhodophyta)
Although the ecological importance of rhodolith (maerl, free-living coralline algae) beds is well-known, rhodolith-forming species have been neglected in molecular phylogenetic studies. This is the first molecular systematic study aimed at understanding whether the rhodolith habit is a fixed feature in lineages and determining the relationship (phylogenetic vs. environmental) between rhodolith and crustose habits. Phylogenetic relationships of rhodolith-forming species and encrusting coralline algae at generic and species levels were analysed using SSU rDNA and psbA sequences. Extensive sampling in the European North Atlantic, Pacific and Caribbean Mexico of Phymatolithon, Lithothamnion, Lithophyllum and Neogoniolithon taxa forming rhodoliths and crusts was accompanied by examination of type or topotype material. Phylogenetic reconstruction showed that Neogoniolithon contained a monophyletic group of rhodolith-forming species whereas other rhodolith-formers were closely related to encrusting forms in the genera Phymatolithon, Lithothamnion, Mesophyllum, Hydrolithon, Spongites and Sporolithon. DNA analysis showed that the crust-forming Lithophyllum cf. incrustans/dentatum also forms rhodoliths with a stone nucleus that occur on rocky shores. In contrast, species that form beds of non-nucleate rhodoliths (e.g. Neogoniolithon spectabile, N. strictum, Lithophyllum cf. incrustans/dentatum or sp. 1 and Phymatolithon calcareum) rarely form crusts. The rhodolith habit cannot be used to delimit species for taxonomic or identification purposes. Extensive taxonomic revision will be required to deal with problems such as the position of specimens identified as Lithophyllum margaritae in two unrelated lineages
Study of Beauveria bassiana growth, blastospore yield, desiccation-tolerance, viability and toxic activity using different liquid media
Beauveria bassiana was grown on three liquid media containing casaminoacids, corn steep liquor or peptone. After incubation, the blastospore counts reached 6.38 × 109 blastospores/ml, in the medium containing sucrose and corn steep liquor, which was significantly higher than the obtained with media containing casaminoacids or peptone. The medium containing corn steep liquor produced predominately submerged conidia, meanwhile the other media produced blastospores. The blastospores produced in the medium containing casaminoacids presented faster germination rates, than the blastospores produced in media containing corn steep liquor or peptone, although, after airdrying, were observed significant reductions on the viability of blastospores produced in the media composed by casaminoacids or peptone, but the spores produced in the medium with corn steep liquor were not affected. For storage of blastospores at 4 and 26°C after some months, the blastospores produced in the medium with casaminoacids showed the highest viability at 26°C, whereas at 4°C the counts of viable blastospores produced in medium containing corn steep liquor were significantly higher than the counts of blastospores produced in the other media with casaminoacids or peptone. The blastospores maintained for six months at 4°C showed high mortality against third-instar Plutella xylostella larvae.Key words: Beauveria bassiana, liquid media, fermentation, short times of propagation, biological control, entomopathogen fungus
Identifying masked uncontrolled hypertension in the community pharmacy setting
© 2015 Wolters Kluwer Health, Inc. Masked uncontrolled hypertension (MUCH) is associated with an increased cardiovascular risk. This condition is frequent in the community pharmacy (i.e., CP-MUCH), but there is no evidence on the factors associated with its presence in that setting. The aim of this analysis was to explore these factors. A sample of 98 treated hypertensive patients from the MEPAFAR study, with normal community pharmacy blood pressure (CPBP <135/85 mmHg), were analyzed. Blood pressure (BP) was also measured at home (4 days) and monitored for 24 h. CP-MUCH was identified when either ambulatory (daytime) or home BP averages were equal to or higher than 135/85 mmHg. A multivariate logistic regression analysis was carried out to identify the factors associated with CP-MUCH. The prevalence of CP-MUCH tends to be higher as systolic and diastolic CPBP increase, reaching 47% in patients with both systolicand diastolic CPBP equal to or higher than 123 mmHg and 79 mmHg, respectively.The multivariate regression analysis showed only systolic CPBP as an independent factor of CP-MUCH [≥123 mmHg: odds ratio=16.46 (P=0.012); from 115 to 122.9 mmHg: odds ratio=10.74 (P=0.036); systolic CPBP <115 mmHg as the reference]. Further assessment, using ambulatory and/or home BP monitoring, is recommended in patients with normal CPBP, but systolic CPBP equal to or higher than 115 mmHg. A more feasible approach would be evaluating patients with systolic CPBP equal to or higher than 123 mmHg and diastolic CPBP equal to or higher than 79 mmHg
Salivary Parameters (Salivary Flow, pH and Buffering Capacity) in Stimulated Saliva of Mexican Elders 60 Years Old and Older
Objective: To compare a limited array of chewing-stimulated saliva features (salivary flow, pH and
buffer capacity) in a sample of elderly Mexicans with clinical, sociodemographic and socio-economic
variables.
Subjects and Methods: A cross-sectional study was carried out in 139 adults, 60 years old and older,
from two retirement homes and a senior day care centre in the city of Pachuca, Mexico. Sociodemographic, socio-economic and behavioural variables were collected through a questionnaire. A
trained and standardized examiner obtained the oral clinical variables. Chewing-stimulated saliva
(paraffin method) was collected and the salivary flow rate, pH and buffer capacity were measured. The
analysis was performed using non-parametric tests in Stata 9.0.
Results: Mean age was 79.1 ± 9.8 years. Most of the subjects included were women (69.1%). Mean
chewing-stimulated salivary flow was 0.75 ± 0.80 mL/minute, and the pH and buffer capacity were 7.88
± 0.83 and 4.20 ± 1.24, respectively. Mean chewing-stimulated salivary flow varied (p < 0.05) across
type of retirement home, tooth brushing frequency, number of missing teeth and use of dental prostheses.
pH varied across the type of retirement home (p < 0.05) and marginally by age (p = 0.087); buffer
capacity (p < 0.05) varied across type of retirement home, tobacco consumption and the number of
missing teeth.
Conclusions: These exploratory data add to the body of knowledge with regard to chewing-stimulated
salivary features (salivary flow rate, pH and buffer capacity) and outline the variability of those features
across selected sociodemographic, socio-economic and behavioural variables in a group of Mexican
elders
Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System
The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species
The submarine volcano eruption at the island of El Hierro: physical-chemical perturbation and biological response
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Quantitative study of hydration of C3S and C2S by thermal analysis. Evolution and composition of C-S-H gels formed
This research is part of a European project (namely, CODICE project), main objective of which is modelling, at a multi-scale, the evolution of the mechanical performance of non-degraded and degraded cementitious matrices. For that, a series of experiments were planned with pure synthetic tri-calcium silicate (C3S) and bi-calcium silicate (C2S) (main components of the Portland cement clinker) to obtain different calcium–silicate–hydrate (C–S–H) gel structures during their hydration. The characterization of those C–S–H gels and matrices will provide experimental parameters for the validation of the multi-scale modelling scheme proposed. In this article, a quantitative method, based on thermal analyses, has been used for the determination of the chemical composition of the C–S–H gel together with the degree of hydration and quantitative evolution of all the components of the pastes. Besides, the microstructure and type of silicate tetrahedron and mean chain length (MCL) were studied by scanning electron microscopy (SEM) and 29Si magic-angle-spinning (MAS) NMR, respectively. The main results showed that the chemical compositions for the C–S–H gels have a CaO/SiO2 M ratio almost constant of 1.7 for both C3S and C2S compounds. Small differences were found in the gel water content: the H2O/SiO2 M ratio ranged from 2.9 ± 0.2 to 2.6 ± 0.2 for the C3S (decrease) and from 2.4 ± 0.2 to 3.2 ± 0.2 for the C2S (increase). The MCL values of the C–S–H gels, determined from 29Si MAS NMR, were 3.5 and 4 silicate tetrahedron, for the hydrated C3S and C2S, respectively, remaining almost constant at all hydration periods
Nuevas aportaciones a la gestión informatizada de derrames de hidrocarburos: su aplicación a "zonas refugio"
pEl objeto del presente trabajo es el de describir la mayor parte de los procedimientos a seguir para decidir si es aconsejable trasladar un petrolero siniestrado a una “zona refugio”. Para tomar esta decisión se deberán considerar diferentes procedimientos, con la finalidad de objetivizar al máximo dicha decisión. Es de gran importancia conocer muy bien las características y las infraestructuras de las diferentes zonas costeras que pueden ser consideradas posibles “zonas refugio”. En base a todo lo anterior, se ha desarrollado un programa formado por varios módulos que permiten obtener datos de gran importancia, entre los que se incluyen las matrices de valores ambientales e infraestructurales, y que permite el cálculo de determinados factores determinantes para las actuaciones de traslado y preparación del petrolero (tiempo de traslado del petrolero, tiempo de atraque y conexión a los sistemas de bombeo, tiempo de vaciado de los hidrocarburos a los depósitos de almacenamiento, trasvase a otro petrolero, etc.). Además, dicho programa permite estimar los costes de limpieza y restauración, así como las pérdidas en el sector turístico./pp /ppstrongPalabras claves:/strong Hidrocarburos; Zona refugio; Derrames de hidrocarburos/p pDOI: a href="http://dx.doi.org/10.5377/nexo.v24i1.590"http://dx.doi.org/10.5377/nexo.v24i1.590/a/p pNexo, Vol. 24, No. 1, pp. 11-19, 2011/
Beyond aridification: multiple explanations for the elevated diversification of cacti in the New World Succulent Biome
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106989/1/nph12752.pd
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