23 research outputs found
New insights into Capsicum spp relatedness and the diversification process of Capsicum annuum in Spain
The successful exploitation of germplasm banks, harbouring plant genetic resources indispensable for plant breeding, will depend on our ability to characterize their genetic diversity. The Vegetable Germplasm Bank of Zaragoza (BGHZ) (Spain) holds an important Capsicum annuum collection, where most of the Spanish pepper variability is represented, as well as several accessions of other domesticated and non-domesticated Capsicum spp from all over the five continents. In the present work, a total of 51 C. annuum landraces (mainly from Spain) and 51 accessions from nine Capsicum species maintained at the BGHZ were evaluated using 39 microsatellite (SSR) markers spanning the whole genome. The 39 polymorphic markers allowed the detection of 381 alleles, with an average of 9.8 alleles per locus. A sizeable proportion of alleles (41.2%) were recorded as specific alleles and the majority of these were present at very low frequencies (rare alleles). Multivariate and model-based analyses partitioned the collection in seven clusters comprising the ten different Capsicum spp analysed: C. annuum, C. chinense, C. frutescens, C. pubescens, C. bacatum, C. chacoense and C. eximium. The data clearly showed the close relationships between C. chinense and C. frutescens. C. cardenasii and C. eximium were indistinguishable as a single, morphologically variable species. Moreover, C. chacoense was placed between C. baccatum and C. pubescens complexes. The C. annuum group was structured into three main clusters, mostly according to the pepper fruit shape, size and potential pungency. Results suggest that the diversification of C. annuum in Spain may occur from a rather limited gene pool, still represented by few landraces with ancestral traits. This ancient population would suffer from local selection at the distinct geographical regions of Spain, giving way to pungent and elongated fruited peppers in the South and Center, while sweet blocky and triangular types in Northern Spain
The clumpy structure of Eridani's debris disc revisited by ALMA
Eridani is the closest star to our Sun known to host a debris
disc. Prior observations in the (sub-)millimetre regime have potentially
detected clumpy structure in the disc and attributed this to interactions with
an (as yet) undetected planet. However, the prior observations were unable to
distinguish between structure in the disc and background confusion. Here we
present the first ALMA image of the entire disc, which has a resolution of
1.6"1.2". We clearly detect the star, the main belt and two point
sources. The resolution and sensitivity of this data allow us to clearly
distinguish background galaxies (that show up as point sources) from the disc
emission. We show that the two point sources are consistent with background
galaxies. After taking account of these, we find that resolved residuals are
still present in the main belt, including two clumps with a
significance -- one to the east of the star and the other to the northwest. We
perform -body simulations to demonstrate that a migrating planet can form
structures similar to those observed by trapping planetesimals in resonances.
We find that the observed features can be reproduced by a migrating planet
trapping planetesimals in the 2:1 mean motion resonance and the symmetry of the
most prominent clumps means that the planet should have a position angle of
either or . Observations over multiple epochs
are necessary to test whether the observed features rotate around the star.Comment: 16 pages, 10 figures, accepted for publication in MNRA
Brightness and mass accretion rate evolution during the 2022 burst of EX~Lupi
EX Lupi is the prototype by which EXor-type outbursts were defined. It has experienced multiple accretion-related bursts and outbursts throughout the last decades, whose study have greatly extended our knowledge about the effects of these types of events. This star experienced a new burst in 2022. We used multi-band photometry to create color-color and color-magnitude diagrams to exclude the possibility that the brightening could be explained by a decrease in extinction. We obtained VLT/X-shooter spectra to determine the Lacc and Macc during the peak of the burst and after its return to quiescence using 2 methods: empirical relationships between line luminosity and Lacc, and a slab model of the whole spectrum. We examined the 130 year light curve of EX Lupi to provide statistics on the number of outbursts experienced during this period of time. Our analysis of the data taken during the 2022 burst confirmed that a change in extinction is not responsible for the brightening. Our two approaches in calculating the Macc were in agreement, and resulted in values that are 2 orders of magnitude above what had previously been estimated, thus suggesting that EX Lupi is a strong accretor even when in quiescence. We determined that in 2022 March the Macc increased by a factor of 7 with respect to the quiescent level. We also found hints that even though the Macc had returned to almost its pre-outburst levels, certain physical properties of the gas had not returned to the quiescent values. We found that the mass accreted during this three month event was 0.8 lunar masses, which is approximately half of what is accreted during a year of quiescence. We calculated that if EX Lupi remains as active as it has been for the past 130 years, during which it has experienced at least 3 outbursts and 10 bursts, then it will deplete the mass of its circumstellar material in less than 160000 yr
Binary Switching of Calendar Cells in the Pituitary Defines the Phase of the Circannual Cycle in Mammals
Persistent free-running circannual (approximately year-long) rhythms have evolved in animals to regulate hormone cycles, drive metabolic rhythms (including hibernation), and time annual reproduction. Recent studies have defined the photoperiodic input to this rhythm, wherein melatonin acts on thyrotroph cells of the pituitary pars tuberalis (PT), leading to seasonal changes in the control of thyroid hormone metabolism in the hypothalamus. However, seasonal rhythms persist in constant conditions in many species in the absence of a changing photoperiod signal, leading to the generation of circannual cycles. It is not known which cells, tissues, and pathways generate these remarkable long-term rhythmic processes. We show that individual PT thyrotrophs can be in one of two binary states reflecting either a long (EYA3+) or short (CHGA+) photoperiod, with the relative proportion in each state defining the phase of the circannual cycle. We also show that a morphogenic cycle driven by the PT leads to extensive re-modeling of the PT and hypothalamus over the circannual cycle. We propose that the PT may employ a recapitulated developmental pathway to drive changes in morphology of tissues and cells. Our data are consistent with the hypothesis that the circannual timer may reside within the PT thyrotroph and is encoded by a binary switch timing mechanism, which may regulate the generation of circannual neuroendocrine rhythms, leading to dynamic re-modeling of the hypothalamic interface. In summary, the PT-ventral hypothalamus now appears to be a prime structure involved in long-term rhythm generation
A genome-wide identification and comparative analysis of the lentil MLO genes
Revista electrónica on linePowdery mildew is a widespread fungal plant disease that can cause significant losses in
many crops. Some MLO genes (Mildew resistance locus O) have proved to confer a durable
resistance to powdery mildew in several species. Resistance granted by the MLO gene family
members has prompted an increasing interest in characterizing these genes and implementing
their use in plant breeding. Lentil (Lens culinaris Medik.) is a widely grown food
legume almost exclusively consumed as dry seed with an average world production of 4.5
million tons. Powdery mildew causes severe losses on certain lentil cultivars under particular
environmental conditions. Data mining of the lentil CDC Redberry draft genome allowed to
identify up to 15 gene sequences with homology to known MLO genes, designated as
LcMLOs. Further characterization of these gene sequences and their deduced protein
sequences demonstrated conformity with key MLO protein characteristics such as the presence
of transmembrane and calmodulin binding domains, as well as that of other conserved
motifs. Phylogenetic and other comparative analyses revealed that LcMLO1 and LcMLO3
are the most likely gene orthologs related to powdery mildew response in other species,
sharing a high similarity with other known resistance genes of dicot species, such as pea
PsMLO1 and Medicago truncatula MtMLO1 and MtMLO3. Sets of primers were designed
as tools to PCR amplify the genomic sequences of LcMLO1 and LcMLO3, also to screen
lentil germplasm in search of resistance mutants. Primers were used to obtain the complete
sequences of these two genes in all of the six wild lentil relatives. Respective to each gene,
all Lens sequences shared a high similarity. Likewise, we used these primers to screen a
working collection of 58 cultivated and 23 wild lentil accessions in search of length polymorphisms
present in these two genes. All these data widen the insights on this gene family and
can be useful for breeding programs in lentil and close related species.S
Botella orgánica
A día de hoy el plástico causa muchos problemas al medioambiente, por lo que hemos pensado una alternativa capaz de hacer frente a los daños medioambientales que producen las botellas convencionales de plástico.Hemos utilizado un bioplástico junto a una calabaza butternut reseca, para dar estructura a lo que sería nuestra botella orgánica, siendo estas más económicas respecto al tiempo de uso. El fin de este material amorfo utilizado es dar resistencia a impactos, deformación elástica y proteger a la calabaza de ser comida por otros seres vivos. Hemos puesto a prueba este material haciendo distintos tipos de ensayos para comprobar sus propiedades y hemos comprobado que estamos ante un material 100 % biodegradable
Une horloge circannuelle sonne le réveil des hibernants [= A circannual clock wakes up hibernating mammals].
news2015 Apr2015 05 08importe
Valorisation of Sargassum muticum through the extraction of phenolic compounds using eutectic solvents and intensification techniques
Seaweeds are naturally abundant and spread all over the globe. They have several biologically active secondary metabolites of great interest. In this work, Sargassum muticum was the algae employed as biomass and the aim was to extract phenolic compounds (PCs) using eutectic solvents (ESs). Several betaine-based, proline-based, and choline-based ESs were tested for the extraction of PCs. All extracts were evaluated according to the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity (DPPH). Afterwards, the extracts were characterized using HPLC in terms of 9 target PCs (gallic acid, 3,4-dihydroxybenzoic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, salicylic acid, catechin and quercetin). Proline combined with propylene glycol (Pro[thin space (1/6-em)]:[thin space (1/6-em)]PPG) exhibited a higher yield according to HPLC results, followed by proline[thin space (1/6-em)]:[thin space (1/6-em)]1,2-butanediol (Pro[thin space (1/6-em)]:[thin space (1/6-em)]1,2-But) and choline[thin space (1/6-em)]:[thin space (1/6-em)]citric acid (ChCl[thin space (1/6-em)]:[thin space (1/6-em)]CA). Pro[thin space (1/6-em)]:[thin space (1/6-em)]PPG also presented high selectivity towards salicylic acid, while ChCl[thin space (1/6-em)]:[thin space (1/6-em)]CA towards gallic acid. Optimization studies of water content and temperature were performed for the three best ESs, the optimum conditions being 30% (v/v) water and 60 °C extraction temperature. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) were two intensification methods evaluated to enhance the extraction process, proving their ability to reduce the extraction time when compared with the conventional solid–liquid extraction (SLE) process. In particular, Pro[thin space (1/6-em)]:[thin space (1/6-em)]PPG-based MAE provided a significantly higher extraction yield in comparison with conventional extraction and with the other extraction solvents. In summary, the combination of ESs with intensification techniques was shown to be a valuable valorization strategy of a marine macroalgae waste, in particular Sargassum muticum.info:eu-repo/semantics/publishedVersio
APEX Observations of the CO Envelope around the Young FUor-type Star V883 Ori
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