324 research outputs found
Gradual evolution of allopolyploidy in Arabidopsis suecica.
Most diploid organisms have polyploid ancestors. The evolutionary process of polyploidization is poorly understood but has frequently been conjectured to involve some form of 'genome shock', such as genome reorganization and subgenome expression dominance. Here we study polyploidization in Arabidopsis suecica, a post-glacial allopolyploid species formed via hybridization of Arabidopsis thaliana and Arabidopsis arenosa. We generated a chromosome-level genome assembly of A. suecica and complemented it with polymorphism and transcriptome data from all species. Despite a divergence around 6 million years ago (Ma) between the ancestral species and differences in their genome composition, we see no evidence of a genome shock: the A. suecica genome is colinear with the ancestral genomes; there is no subgenome dominance in expression; and transposon dynamics appear stable. However, we find changes suggesting gradual adaptation to polyploidy. In particular, the A. thaliana subgenome shows upregulation of meiosis-related genes, possibly to prevent aneuploidy and undesirable homeologous exchanges that are observed in synthetic A. suecica, and the A. arenosa subgenome shows upregulation of cyto-nuclear processes, possibly in response to the new cytoplasmic environment of A. suecica, with plastids maternally inherited from A. thaliana. These changes are not seen in synthetic hybrids, and thus are likely to represent subsequent evolution
Description of the initial ontogenic development of the Dorada Brycon moorei (Characiformes: Bryconidae)
Ontogeny is a biological process associated with the appearance or disappearance of anatomical structures and physiological associated process. The objective of this work is to describe ontogenic development of Brycon moorei, an oviparous and potamodromous fish species. It is a contribution to a better understanding of its initial development. Samples were obtained from parents kept in captivity. Woynarovich-type incubators were used for the embryos and cement ponds for the larvae, both with a constant supply of water at an average temperature of 27 ºC and food availability. The hours post-fertilization (HPF) of ontogeny were recorded. The optic capsule was evident at 9 HPF, the opening of the mouth and anus at 23 and 24 HPF respectively. Duration of each phase during the embryonic period: cleavage (4 h), gastrulation (3 h), embryogenesis (7 h) and, of the larval period: vitelline larva (28 h), pre-flexion (61 h), flexion (80 h) and post-flexion (>170 h). In each period and phase the analysis of its shape was carried out using distance measurements. Larvae had a considerable increase in length with the HPF. Total number of myomers was kept constant since preflexion phase. Our results can be used to explain the general picture of early development of B. moorei under captivity conditions. Also, they can help develop better breeding methods for larvae in production and to find diagnostic characters that can be used at thein taxonomic level
Monitoring spin-crossover phenomena via Re(I) luminescence in hybrid Fe(II) silica coated nanoparticles
Financial support from Projects CTQ2014-56312-P and PGC2018-102052-B-C21 financed by MCIN/AEI/10.13039/501100011033/FEDER "Una manera de hacer Europa", the Junta de Andalucia (FQM-195), Feder project A-FQM-172UGR18 and the University of Granada is gratefully acknowledged. I.-F. Diaz-Ortega and J.-R Jimenez are also thankful to the Junta de Andalucia for Postdoctoral research fellowships.Bare (1) and silica coated (1@SiO2) spin crossover (SCO) nanoparticles based on the polymer {[Fe
(NH2Trz)3](BF4)2}n have been prepared following a water-in-oil synthetic procedure. For 1, the critical
temperatures of the spin transition are TC↓ = 214.6 K and TC↑ = 220.9 K. For 1@SiO2, the abruptness of
the transition is enhanced and the critical temperatures are centred at room temperature (TC↓ = 292.1 K
and TC↑ = 296.3 K). An inert Re(I) complex of formula [Re(phen)(CO)3(PETES)](PF6) (phen = 1, 10-phenanthroline;
PETES = 2(4-pyridylethyl)triethoxysilane) (Re) was also synthesized yielding intense green emission
centred at λem = 560 nm. The grafting of this complex on the silica shell of 1@SiO2 led to a bifunctional
SCO-luminescence composite (1@SiO2/Re) whose luminescence properties were tuned by the
spin state switching. Temperature-variable photophysical studies showed that luminescence and spin
transition were synchronized through a radiative (trivial) energy transfer mechanism between the Re(I) and
the Fe(II)-LS (LS, Low Spin) centres.FEDER "Una manera de hacer Europa" CTQ2014-56312-P
PGC2018-102052-B-C21Junta de Andalucia FQM-195European Commission A-FQM-172UGR18University of GranadaJunta de Andaluci
A research agenda on geoinformation sciences towards responsible land administration in Colombia
Desarrollo de un medio de cultivo para potenciar la producción de componentes bioactivos en la microalga autóctona Scenedesmus obliquus
Se estudió el efecto de fuentes de nitrógeno (nitrato de sodio y urea) y de carbono (acetato de sodio y glucosa), así como el estrés salino (cloruro de sodio) sobre cultivo de la microalga Scenedesmus obliquus que potencien la producción de carotenoides totales, proteínas totales y fenoles totales. Se empleó como medio de cultivo base Allen & Arnon y la microalga Scenedesmus obliquus autóctona del Embalse de Salto Grande. Las condiciones experimentales que favorecieron la obtención de biomasa de microalga Scenedesmus obliquus rica en componentes bioactivos fueron: para carotenoides totales 0,24g urea/L; 3,68g glucosa/L y 54,71µmol/(m2s); proteínas totales 0,24g urea/L; 5,02g acetato de sodio/L y 54,71µmol/(m2s) y fenoles totales 31,00g urea/L; 3,68g glucosa/L y 45,04µmol/(m2 s). La concentración de carotenoides totales obtenida fue 473,85±11,00mg β-caroteno/g ms; de proteínas totales 7,09±0,23mg ASB/g ms y de fenoles totales, 16,78±0,84mg EAG/g ms. El estrés salino se desestimó ya que provocó una disminución de la concentración de los componentes de interés. De lo expuesto se concluye que el cultivo de Scenedesmus obliquus, bajo las condiciones de estrés señaladas, representa un proceso biotecnológico atractivo para la obtención de biomasa rica en componentes bioactivos con potencialidad para ser utilizada como aditivo natural en la formulación de alimentos
ARK: http://id.caicyt.gov.ar/ark:/s22504559/t9bmfmnb
Relation between coliphages presence in drinking water, rain and acute diarrhea in Costa Rica
La calidad del agua de consumo es una de las preocupaciones más grandes a las que se enfrentan los entes de salud. En Costa Rica, a pesar de la buena calidad de las fuentes de agua y del agua de consumo, se siguen registrando numerosos casos de diarrea anualmente. En este estudio se realizó un análisis de indicadores de contaminación virales y bacterianos, en dos comunidades del Valle Central con acueducto propio. Se analizaron en total 24 muestras de agua por cada comunidad, durante un año, 12 en la fuente de agua y 12 en el agua tratada. La frecuencia de diarreas en cada comunidad fue comparada con la calidad microbiológica del agua consumida, encontrándose ausencia de indicadores bacterianos en muestras de agua tratada, mientras que la presencia de indicadores virales en el agua de consumo (con cloro residual) se relaciona con un incremento en el número de casos de diarreas, adicionalmente se analizó el comportamiento de las diarreas de acuerdo a la precipitación promedio con el fin de observar posibles patrones de estacionalidad. Estos hallazgos respaldan la necesidad de ampliar el monitoreo de calidad microbiológica del agua con otro tipo de indicadores de contaminación que correlacionen mejor con otros agentes patógenos de transmisión hídrica, principalmente en época seca, periodo en que se observan más casos de diarrea.The quality of potable water is one of the
most important issues of public health. In
Costa Rica, in spite of having good
sources of water and good quality of water
for consumption, there continues to be a
significant number of diarrhea cases
annually. In
this
investigation,
viral and
bacterial analyses of indicators of
contamination were conducted in two rural
communities with their own aqueducts in
the Central Valley of Costa Rica. Twenty
-
four samples were taken from each
community during the year; 12 fro
m the
water sources and 12 from the treated
waters. The frequency of diarrhea in each community was compared to the
microbiological quality of the water being
consumed, noting an absence of bacterial
indicators in samples of treated water,
while the presen
ce of viral indicators in the
water (with residual chlorine) were
associated with an incremental increase in
the number of cases of diarrhea. The
analysis also included measurements of
average monthly rainfall with the aim of
observing possible association
s between
seasonal conditions and the incidence of
diarrhea cases. These findings indicate
the need to increase the monitoring of the
microbiological quality of the water with
other types of indicators of contamination
that correlate better with other path
ogens
transmitted by water, especially in the dry
seasons when a greater number of cases
of diarrhea are observed.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA
The role of high-resolution analytical techniques in the development of functional foods
The approaches based on high-resolution analytical techniques, such as nuclear magnetic resonance or mass spectrometry coupled to chromatographic techniques, have a determining role in several of the stages necessary for the development of functional foods. The analyses of botanical extracts rich in bioactive compounds is one of the fundamental steps in order to identify and quantify their phytochemical composition. However, the compounds characterized in the extracts are not always responsible for the bioactive properties because they generally undergo metabolic reactions before reaching the therapeutic targets. For this reason, analytical techniques are also applied to analyze biological samples to know the bioavailability, pharmacokinetics and/or metabolism of the compounds ingested by animal or human models in nutritional intervention studies. In addition, these studies have also been applied to determine changes of endogenous metabolites caused by prolonged intake of compounds with bioactive potential. This review aims to describe the main types and modes of application of high-resolution analytical techniques in all these steps for functional food development
Nrf2-Mediated Antioxidant Activity of the inner bark extracts obtained from Tabebuia rosea (Bertol) DC and Tabebuia chrysantha (JACQ) G. Nicholson. [version 2; referees: 2 approved]
Background: Several ethnobotanical and ethnopharmacological studies have shown the therapeutic potential of plants from the genus Tabebuia, which have long been used in traditional medicine in rural areas of South America, for the treatment of several human diseases. This study aimed to evaluate the Nrf2-mediated antioxidant activity of the inner bark extracts obtained from Tabebuia rosea and Tabebuia chrysantha. Methods: The antioxidant activity of extracts obtained from the inner bark of T. rosea and T. chrysantha was evaluated using the Oxygen radical absorbance capacity (ORAC) technique. The effect of extracts on the viability of HepG2 cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. The translocation of Nrf2 to the nucleus after exposure of HepG2 cells to the extracts and controls (α-lipoic acid, curcumin and hydrogen peroxide) was evaluated using the Nrf2 transcription factor kit. Induction of the Nrf2-mediated antioxidant response gene (NQO1) was evaluated by real-time PCR. Results: The ethyl acetate extract obtained from both species displayed the highest ORAC activity (12,523 and 6,325 µmoles Eq Trolox/g extract). In addition, the extracts had the ability to activate and to translocate Nrf2 to the nucleus, as well as to induce the expression of NQO1. Conclusion: These results indicate that the ethyl acetate extracts obtained from the inner bark of T. chrysantha and T. rosea have an important antioxidant effect mediated by Nrf2 activation, and could be used as a new source of natural antioxidants
Updating known distribution models for forecasting climate change impact on endangered species
To plan endangered species conservation and to design adequate management programmes, it is necessary to predict their
distributional response to climate change, especially under the current situation of rapid change. However, these
predictions are customarily done by relating de novo the distribution of the species with climatic conditions with no regard
of previously available knowledge about the factors affecting the species distribution. We propose to take advantage of
known species distribution models, but proceeding to update them with the variables yielded by climatic models before
projecting them to the future. To exemplify our proposal, the availability of suitable habitat across Spain for the endangered
Bonelli’s Eagle (Aquila fasciata) was modelled by updating a pre-existing model based on current climate and topography to
a combination of different general circulation models and Special Report on Emissions Scenarios. Our results suggested that
the main threat for this endangered species would not be climate change, since all forecasting models show that its
distribution will be maintained and increased in mainland Spain for all the XXI century. We remark on the importance of
linking conservation biology with distribution modelling by updating existing models, frequently available for endangered
species, considering all the known factors conditioning the species’ distribution, instead of building new models that are
based on climate change variables only.Ministerio de Ciencia e Innovación and FEDER (project CGL2009-11316/BOS
The cellular origin and malignant transformation of Waldenström macroglobulinemia
Although information about the molecular pathogenesis of Waldenström macroglobulinemia (WM) has significantly advanced, the precise cell of origin and the mechanisms behind WM transformation from immunoglobulin-M (IgM) monoclonal gammopathy of undetermined significance (MGUS) remain undetermined. Here, we undertook an integrative phenotypic, molecular, and genomic approach to study clonal B cells from newly diagnosed patients with IgM MGUS (n = 22), smoldering (n = 16), and symptomatic WM (n = 11). Through principal component analysis of multidimensional flow cytometry data, we demonstrated highly overlapping phenotypic profiles for clonal B cells from IgM MGUS, smoldering, and symptomatic WM patients. Similarly, virtually no genes were significantly deregulated between fluorescence-activated cell sorter-sorted clonal B cells from the 3 disease groups. Interestingly, the transcriptome of the Waldenström B-cell clone was highly different than that of normal CD25-CD22+ B cells, whereas significantly less genes were differentially expressed and specific WM pathways normalized once the transcriptome of the Waldenström B-cell clone was compared with its normal phenotypic (CD25+CD22+low) B-cell counterpart. The frequency of specific copy number abnormalities [+4, del(6q23.3-6q25.3), +12, and +18q11-18q23] progressively increased from IgM MGUS and smoldering WM vs symptomatic WM (18% vs 20% and 73%, respectively; P = .008), suggesting a multistep transformation of clonal B cells that, albeit benign (ie, IgM MGUS and smoldering WM), already harbor the phenotypic and molecular signatures of the malignant Waldenström clone.This study was supported by Cooperative Research Thematic Network grants RD12/0036/0058 and RD12/0036/0048 of the Red de Cancer (Cancer Network of Excellence), Consejería de Sanidad, Junta de Castilla y Leon, Valladolid, Spain (557/A/10).Peer Reviewe
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