PopStar I: evolutionary synthesis model description Mollá, M.; García-Vargas, M. L.; Bressan, A.
Monthly Notices of the Royal Astronomical Society,
September 2009, Letnik:
398, Številka:
1
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We present new evolutionary synthesis models for simple stellar populations for a wide range of ages and metallicities. The models are based on the Padova isochrones. The core of the spectral library ...is provided by the medium resolution Lejeune et al. atmosphere models. These spectra are complemented by Non Local Thermodynamic Equilibrium (NLTE) atmosphere models for hot stars that have an important impact on the stellar cluster's ionizing spectra: O, B and WR stellar spectra at the early ages, and spectra of post asymptotic giant branch stars and planetary nebulae, at intermediate and old ages. At young ages, our models compare well with other existing models, but we find that the inclusion of the nebular continuum, not considered in several other models, significantly reddens the integrated colours of very young stellar populations. This is consistent with the results of spectral synthesis codes particularly devised for the study of starburst galaxies. At intermediate and old ages, the agreement with the literature model is good and, in particular, we reproduce the observed colours of star clusters in Large Magellanic Cloud well. Given the ability to produce good integrated spectra from the far-ultraviolet to the infrared at any age, we consider that our models are particularly suited for the study of high-redshift galaxies. These models are available on the web site http://www.fractal-es.com/SEDmod.htm and also through the Virtual Observatory Tools on the PopStar server.
The isolation and characterization of the phytoene synthase gene from the green microalga
Chlorella zofingiensis
(
CzPSY
), involved in the first step of the carotenoids biosynthetic pathway, have ...been performed.
CzPSY
gene encodes a polypeptide of 420 amino acids. A single copy of
CzPSY
has been found in
C. zofingiensis
by Southern blot analysis. Heterologous genetic complementation in
Escherichia coli
showed the ability of the predicted protein to catalyze the condensation of two molecules of geranylgeranyl pyrophosphate (GGPP) to form phytoene. Phylogenetic analysis has shown that the deduced protein forms a cluster with the rest of the phytoene synthases (PSY) of the chlorophycean microalgae studied, being very closely related to PSY of plants. This new isolated gene has been adequately inserted in a vector and expressed in
Chlamydomonas reinhardtii
. The overexpression of
CzPSY
in
C. reinhardtii
, by nuclear transformation, has led to an increase in the corresponding
CzPSY
transcript level as well as in the content of the carotenoids violaxanthin and lutein which were 2.0- and 2.2-fold higher than in untransformed cells. This is an example of manipulation of the carotenogenic pathway in eukaryotic microalgae, which can open up the possibility of enhancing the productivity of commercial carotenoids by molecular engineering.
Aim: In recent years evidence has accumulated that plant species are differentially sorted from regional assemblages into local assemblages along local-scale environmental gradients on the basis of ...their function and abiotic filtering. The favour-ability hypothesis in biogeography proposes that in climatically difficult regions abiotic filtering should produce a regional assemblage that is less functionally diverse than that expected given the species richness and the global pool of traits. Thus it seems likely that differential filtering of plant traits along local-scale gradients may scale up to explain the distribution, diversity and filtering of plant traits in regional-scale assemblages across continents. The present work aims to address this prediction. Location: North and South America. Methods: We combine a dataset comprising over 5.5 million georeferenced plant occurrence records with several large plant functional trait databases in order to: (1) quantify how several critical traits associated with plant performance and ecology vary across environmental gradients; and (2) provide the first test of whether the woody plants found within 1° and 5° map grid cells are more or less functionally diverse than expected, given their species richness, across broad gradients. Results: The results show that, for many of the traits studied, the overall distribution of functional traits in tropical regions often exceeds the expectations of random sampling given the species richness. Conversely, temperate regions often had narrower functional trait distributions than their smaller species pools would suggest. Main conclusion: The results show that the overall distribution of function does increase towards the equator, but the functional diversity within regional-scale tropical assemblages is higher than that expected given their species richness. These results are consistent with the hypothesis that abiotic filtering constrains the overall distribution of function in temperate assemblages, but tropical assemblages are not as tightly constrained.
•Gd doped ferrites were synthesized under controlled concentration.•Gd ion induced structural changes are significant.•Gd-incorporation changes the dielectric relaxations.•Two-layer heterogeneous ...model proposed accounts for dielectric properties.•A correlation between microstructure and electrical properties is established.
Gadolinium (Gd) substituted cobalt ferrites (CoFe2−xGdxO4, referred to CFGO) with variable Gd content (x=0.0–0.4) have been synthesized by solid state reaction method. The crystal structure, surface morphology, chemistry, electrical conduction and dielectric properties of CFGO compounds have been evaluated. X-ray diffraction measurements indicate that CFGO crystallize in the inverse spinel phase. The CFGO compounds exhibit lattice expansion due to substitution of larger Gd ions into the crystal lattice. Gd-substitution induced smooth microstructure and particle size reduction is evident in electron microscopy analyses. Frequency dependent dielectric measurements at room temperature obey the modified Debye model with a relaxation time of ∼10−4s and a spreading factor of 0.244–0.616. The frequency (f=20Hz–1MHz) and temperature (T=30–900°C) dependent dielectric constant analyses indicate that pure CFO exhibits two dielectric relaxations in the frequency range of 1–10kHz while Gd substituted CFO compositions exhibit only single relaxation at 1kHz. The dielectric constant of CFGO is temperature independent up to ∼550°C. The dielectric constant increases with T>550°C. Dielectric constant of CoFe2−xGdxO4 ceramics is also enhanced compared to pure CoFe2O4 due to the lattice distortion upon Gd incorporation. The tanδ (loss tangent)–T data reveals the typical behavior of relaxation loses in CFGO. Activation energy of the dielectric relaxation calculated employing Arrhenius equation varies from 0.564 to 0.668 (±0.003)eV with increasing x values from 0.0 to 0.4. Thermally activated small polaron hopping mechanism is evident in temperature dependent electrical properties of CFGO. The effect of Gd-substitution in CFO is remarkable on the resistivity and, hence, activation energy; both increases with increasing Gd content. A two-layer heterogeneous model consisting of semiconducting grains separated by insulating grain boundaries was able to account for the observed temperature and frequency dependent electrical properties in CFGO ceramics. The results demonstrate that the crystal structure, microstructure, electrical and dielectric properties can be tailored by tuning Gd-content in the CFGO compounds.
An intensive isolation program carried out in three replicated composting piles allowed the identification of the resident and transient components of the composting microbiome. More than 4000 ...bacterial strains were isolated, enzymatically characterized and identified by partial sequencing of their 16S rRNA gene. While microorganisms isolated under mesophilic conditions were prominent throughout the process, thermophilic stages gathered the highest total counts and spore-forming bacteria prevailed at the bio-oxidative phase of composting. Enzymatic capabilities related to the degradation of polymeric materials were exhibited by most of the isolates and as a result of these activities, more soluble compounds could be made available to the entire composting microbiota. A high proportion of isolates showed to be thermotolerant as they were detected at mesophilic and thermophilic phases. Isolated strains belonged to 187 bacterial species. Biodiversity was greater at the central stages of composting and mesophilic, thermophilic and cooling phases shared 50% of species.
High-throughput sequencing is helping biologists to overcome the difficulties of inferring the phylogenies of recently diverged taxa. The present study analyzes the phylogenetic signal of genomic ...regions with different inheritance patterns using genome skimming and ddRAD-seq in a species-rich Andean genus (Diplostephium) and its allies.
We analyzed the complete nuclear ribosomal cistron, the complete chloroplast genome, a partial mitochondrial genome, and a nuclear-ddRAD matrix separately with phylogenetic methods. We applied several approaches to understand the causes of incongruence among datasets, including simulations and the detection of introgression using the D-statistic (ABBA-BABA test).
We found significant incongruence among the nuclear, chloroplast, and mitochondrial phylogenies. The strong signal of hybridization found by simulations and the D-statistic among genera and inside the main clades of Diplostephium indicate reticulate evolution as a main cause of phylogenetic incongruence.
Our results add evidence for a major role of reticulate evolution in events of rapid diversification. Hybridization and introgression confound chloroplast and mitochondrial phylogenies in relation to the species tree as a result of the uniparental inheritance of these genomic regions. Practical implications regarding the prevalence of hybridization are discussed in relation to the phylogenetic method.
Aim
To identify and evaluate randomized clinical trials focusing on economic evaluation of workplace health promotion (WHP) interventions based on healthy lifestyles, physical activity and nutrition.
...Design
A systematic review and meta‐analysis was carried out between March and May 2019, following the PRISMA statement.
Data Sources
The literature search was conducted on Cochrane Library, Scopus, WOS and Medline databases.
Review Methods
The quality appraisal included the overall risk of bias (Cochrane Collaboration tool), the quality of the evidence (GRADEpro) and the quality of the health economic analysis (QHES instrument).
Results
Of the 15 studies selected, 3 were interventions based on nutrition, 11 were focused on lifestyle and only one on physical activity. Given the heterogeneity of included studies, it was decided to do a subgroup analysis. For the weight loss (n = 5 studies), a general increase of 0.56 Kg (95% CI = 0.76, 0.84) I2 = 99.41%, and for the Quality‐adjusted Life Years achieved (n = 5 studies) a very small increase of 0.003 (95% CI = 0.002, 0.004) I2 = 99.25%, were observed.
Conclusions
The implementation of lifestyle interventions in the workplace has proven to be cost‐effective for both employers and society.
Impact
What problem did the study address? There are few studies aimed at evaluating the efficiency of WHP interventions. However, those that identify and assessing interventions related to lifestyle are particularly scarce, despite the evidence showing that these researchers improve the quality of care of occupational health.
What were the main findings? This systematic review demonstrates the effectiveness of the WHP interventions, and in some cases, the efficiency of these interventions for both employers and society. Additional research in this area is necessary as well as the assessment of the cost‐effectiveness of such interventions.
Where and on whom will the research have an impact? To know the cost‐benefit of different WHP interventions allows more efficient management of resources, which helps to make political and business decisions, becoming healthier and safer workplaces.
A simple and straightforward technique for coating microplate wells with molecularly imprinted polymer nanoparticles (nanoMIPs) to develop assays similar to the enzyme-linked immunosorbent assay ...(ELISA) is presented here for the first time. NanoMIPs were synthesized by a solid-phase approach with an immobilized vancomycin (template) and characterized using Biacore 3000, dynamic light scattering, and electron microscopy. Immobilization, blocking, and washing conditions were optimized in microplate format. The detection of vancomycin was achieved in competitive binding experiments with a horseradish peroxidase-vancomycin conjugate. The assay was capable of measuring vancomycin in buffer and in blood plasma within the range of 0.001-70 nM with a detection limit of 0.0025 nM (2.5 pM). The sensitivity of the assay was 3 orders of magnitude better than a previously described ELISA based on antibodies. In these experiments, nanoMIPs have shown high affinity and minimal interference from blood plasma components. Immobilized nanoMIPs were stored for 1 month at room temperature without any detrimental effects to their binding properties. The high affinity of nanoMIPs and the lack of a requirement for cold chain logistics make them an attractive alternative to traditional antibodies used in ELISA.
Smart facemask for wireless CO2 monitoring Escobedo, P.; Fernández-Ramos, M. D.; López-Ruiz, N. ...
Nature communications,
01/2022, Letnik:
13, Številka:
1
Journal Article
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Abstract
The use of facemasks by the general population is recommended worldwide to prevent the spread of SARS-CoV-2. Despite the evidence in favour of facemasks to reduce community transmission, ...there is also agreement on the potential adverse effects of their prolonged usage, mainly caused by CO
2
rebreathing. Herein we report the development of a sensing platform for gaseous CO
2
real-time determination inside FFP2 facemasks. The system consists of an opto-chemical sensor combined with a flexible, battery-less, near-field-enabled tag with resolution and limit of detection of 103 and 140 ppm respectively, and sensor lifetime of 8 h, which is comparable with recommended FFP2 facemask usage times. We include a custom smartphone application for wireless powering, data processing, alert management, results displaying and sharing. Through performance tests during daily activity and exercise monitoring, we demonstrate its utility for non-invasive, wearable health assessment and its potential applicability for preclinical research and diagnostics.
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