862 research outputs found
An investigation of the self- and inter-incompatibility of the olive cultivars 'Arbequina' and 'Koroneiki' in the Mediterranean climate of Sicily
In this investigation, the self-(in)compatibility of the Spanish cultivar Arbequina and the Greek cultivar Koroneiki was studied for the first time in Sicily, where these low vigour cultivars were recently introduced in super-intensive olive groves. Self- (S.P.) and openpollination (O.P.) tests, observation of fruit set and paternity test of seeds with microsatellite (SSR) markers, were performed to ascertain whether these cultivars were self-fertile and/or inter-compatible. For S.P. tests, branches with flowers at the balloon stage were bagged. For the O.P. tests, flowers were left to pollinate under natural conditions. Fruits from S.P. and O.P. were collected in November and fruit set was calculated. Genomic DNA was extracted from seeds. None of the 'Arbequina' seeds studied in either the S.P. or O.P. tests originated from self-fertilization. In addition, none of these seeds had 'Koroneiki' as the pollen parent. In contrast, 'Koroneiki' was found to be predominantly self-compatible in self-bagged branches, with 70% of the seeds originating from selffertilization. However, the incidence of self-fertilization was low (11%) in seeds from the O.P. test. Low levels of inter-compatibility were found between 'Arbequina' and 'Koroneiki', while many local cultivars were found to be good pollinators. The information presented here will be useful to growers for planning their orchards with suitable pollinators and for our breeding program aiming at obtaining new low vigour olive genotypes. In addition, our results suggested that the recent model of attribution of S-alleles and the prediction of suitable pollinizers for a given variety should be more cautious and always based on controlled crosses and paternity testing of seed from those crosses
Modelling perceived value as a driver of tourism development
This study investigates visitors’ perceived value in little known small areas, at the early stage of
tourism development, participating in a European regional development project, for improving
the local tourism supply and marketing initiatives, with limited investments. We suggest to
employ an Ordinal Structural Equation Model with Pairwise Likelihood estimator to deal with
non-normal and missing data. We detect which destinations’ aspects convey the greatest value
to tourists, identify market segmentation variables, test the relations of perceived value with
satisfaction, intention to recommend and destination image. Results are relevant for policymakers
and destination managers, even more in the post-COVID-19 tourism recovery
Constraints on the emission mechanisms of gamma-ray bursts
If the emission of gamma-ray bursts were due to the synchrotron process in
the standard internal shock scenario, then the typical observed spectrum should
have a slope F(nu) \propto nu^{-1/2}, which strongly conflicts with the much
harder spectra observed. This directly follows from the cooling time being much
shorter than the dynamical time. Particle re-acceleration, deviations from
equipartition, fastly changing magnetic fields and adiabatic losses are found
to be inadequate to account for this discrepancy. We also find that in the
internal shock scenario the relativistic inverse Compton scattering is always
as important as the synchrotron process, and faces the same problems. This
indicates that the burst emission is not produced by relativistic electrons
emitting synchrotron and inverse Compton radiation.Comment: 5 pages, accepted for publications in MNRAS, pink page
Titanium dioxide nanoparticles temporarily influence the sea urchin immunological state suppressing inflammatory-relate gene transcription and boosting antioxidant metabolic activity.
Abstract Titanium dioxide nanoparticles (TiO2NPs) are revolutionizing biomedicine due to their potential application as diagnostic and therapeutic agents. However, the TiO2NP immune-compatibility remains an open issue, even for ethical reasons. In this work, we investigated the immunomodulatory effects of TiO2NPs in an emergent proxy to human non-mammalian model for in vitro basic and translational immunology: the sea urchin Paracentrotus lividus. To highlight on the new insights into the evolutionarily conserved intracellular signaling and metabolism pathways involved in immune-TiO2NP recognition/interaction we applied a wide-ranging approach, including electron microscopy, biochemistry, transcriptomics and metabolomics. Findings highlight that TiO2NPs interact with immune cells suppressing the expression of genes encoding for proteins involved in immune response and apoptosis (e.g. NF-κB, FGFR2, JUN, MAPK14, FAS, VEGFR, Casp8), and boosting the immune cell antioxidant metabolic activity (e.g. pentose phosphate, cysteine-methionine, glycine-serine metabolism pathways). TiO2NP uptake was circumscribed to phagosomes/phagolysosomes, depicting harmless vesicular internalization. Our findings underlined that under TiO2NP-exposure sea urchin innate immune system is able to control inflammatory signaling, excite antioxidant metabolic activity and acquire immunological tolerance, providing a new level of understanding of the TiO2NP immune-compatibility that could be useful for the development in Nano medicines
Arrelvados vivazes da bacia hidrográfica do rio Paiva (Portugal)
Apresenta-se um estudo dos arrelvados naturais vivazes da bacia hidrográfica do
rio Paiva, em particular das classes: 1) Festucetea indigestae; 2) Stipo giganteae-Agrostietea
castellanae; 3) Molinio-Arrhenatheretea e 4) Nardetea. Com base em inventários realizados
desde 2004, bem como em trabalhos publicados onde se estudou o território em causa,
reconhecem-se oito associações e uma comunidade enquadráveis nas referidas classes,
respectivamente: 1) Polytricho-Agrostietum truncatulae, Diantho langeani-Festucetum
summilusitanae ass. nova; 2) Arrhenathero bulbosi-Armerietum beiranae ass. nova, com. de
Armeria beirana e Arrhenatherum sardoum; 3) Peucedano lancifolii-Juncetum acutiflori,
Agrostio castellanae-Arrhenatheretum bulbosi, Anthemido nobilis-Cynosuretum cristati; 4)
Centaureo lusitanae-Pseudarrhenatheretum longifolii ass. nova, Genisto anglicae-Nardetum
strictae. Apresenta-se ainda uma associação vegetal casmofÃtica original, enquadrável na classe
Phagnalo-Rumicetea indurati, encontrada no decorrer do presente trabalho, que aqui se
descreve dado o seu valor para a conservação da natureza, dominada pelo endemismo do centro
de Portugal continental Anarrhinum longipedicellatum (Anarrhinetum longipedicellati ass.
nova). Destaca-se o caso particular do arrelvado Arrhenathero bulbosi-Armerietum beiranae,
hoje com grande expressão no território em estudo, ocupando parte considerável das áreas
granÃticas meso a supratemperadas, húmidas a hiper-húmidas, das serras do Montemuro, Leomil
e Lapa. A expansão deste arrelvado está indiscutivelmente ligada quer ao abandono da
agricultura e do pastoreio – que levaram a uma redução considerável das áreas cultivadas, bem
como das comunidades de Molinio-Arrhenatheretea e de Nardetea – quer à elevada frequência de incêndios, dado que se trata de uma comunidade subserial dos carvalhais de Holco mollis-
Quercetum pyrenaicae e, pontualmente, de Rusco aculeati-Quercetum roboris quercetosum
roborisinfo:eu-repo/semantics/publishedVersio
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