340 research outputs found
Landrace added value and accessibility in Europe: what a collection of case studies tells us
In the actual climate change scenario, in situ conservation of plant genetic resources for food and agriculture can significantly contribute broadening the diversity of our food system as well as increasing its resilience; nevertheless, landrace cultivation has been dramatically reduced in the last decades all over Europe. One of the most effective approaches to counteract the loss of landrace diversity in situ is facilitating its use. Aims of this study were to (i) describe how in situ maintenance of landraces occurs in different agro-environmental conditions in Europe and (ii) identify the main factors influencing landrace added values and accessibility as means to increase their adoption by new farmers. To the purpose, a collection of 95 case studies of both garden and open field landraces maintained in situ was analysed. A first description was obtained by classifying the information into 18 purposely defined categories. Data on landraces added values and accessibility were further transformed into weighted variables; the derived quantitative scores were then used as dependent variables in univariate and multivariate analyses. Results showed that farmers alone are still the main actors maintaining landraces in situ across different European biogeographical regions, mainly carrying out their activity under organic or low-input conditions, often in marginal areas. Results of the multivariate analysis showed that (i) type of actor involved in the multiplication, (ii) the main use of the product and (iii) presence of promotion actions significantly affect garden landraces added value and accessibility; presence of promotion actions was the only factor affecting added value of open field entries. Evidence arising from this work can contribute to the establishment of a fruitful ground of discussion for future European policies and strategies to protect and increase landrace use
Investigating the genetic basis of salt-tolerance in common bean: a genome-wide association study at the early vegetative stage
Salinity poses a significant challenge to global crop productivity, affecting approximately 20% of cultivated and 33% of irrigated farmland, and this issue is on the rise. Negative impact of salinity on plant development and metabolism leads to physiological and morphological alterations mainly due to high ion concentration in tissues and the reduced water and nutrients uptake. Common bean (Phaseolus vulgaris L.), a staple food crop accounting for a substantial portion of consumed grain legumes worldwide, is highly susceptible to salt stress resulting in noticeable reduction in dry matter gain in roots and shoots even at low salt concentrations. In this study we screened a common bean panel of diversity encompassing 192 homozygous genotypes for salt tolerance at seedling stage. Phenotypic data were leveraged to identify genomic regions involved in salt stress tolerance in the species through GWAS. We detected seven significant associations between shoot dry weight and SNP markers. The candidate genes, in linkage with the regions associated to salt tolerance or harbouring the detected SNP, showed strong homology with genes known to be involved in salt tolerance in Arabidopsis. Our findings provide valuable insights onto the genetic control of salt tolerance in common bean and represent a first contribution to address the challenge of salinity-induced yield losses in this species and poses the ground to eventually breed salt tolerant common bean varieties
Corrigendum: Airway T cells protect against RSV infection in the absence of antibody
Correction to: Mucosal Immunology (2018) 11, 249–256; doi:10.1038/mi.2017.46; published online 24 May 201
Quebra de dormência em diásporos de teca (Tectona grandis L.f.).
Tectona grandis L.f. é uma essência florestal exótica de importância econômica e social para o Brasil. As mudas dessa espécie são produzidas através de diásporos constituídos dos frutos com endocarpo e mesocarpo rígidos. O objetivo do presente trabalho foi avaliar o efeito de métodos de quebra de dormência na germinação das sementes desta espécie. Para superar a dormência do endocarpo e mesocarpo, os diásporos de teca foram submetidos à imersão em água quente, imersão em ácido sulfúrico (33,5%) e imersão em água corrente. Os diásporos foram distribuídos em substrato constituído de areia, e o teste de germinação foi realizado em câmara de germinação com temperatura de 30 ºC, sob luz branca durante oito horas por dia. As avaliações foram feitas diariamente, durante 60 dias. O método de imersão dos diásporos em ácido sulfúrico por três minutos, foi o tratamento mais eficiente, apresentando 73% das sementes germinadas
Comportamento da Macrofauna edáfica em diferentes modelos de arborização de cafeeiro Robusta (Coffea canephora) em Rondônia.
O levantamento da fauna edáfica do solo é uma forma indicada de avaliar a viabilidade em função do manejo deste tipo de sistema. O objetivo deste trabalho foi fazer um levantamento da ocorrência da macrofauna do solo em 05 (dez) propriedades cultivadas com o café Robusta (Coffea canephora) arborizado no município de Rolim de Moura, localizado na região da Zona da Mata/RO em duas épocas diferentes. Na época chuvosa e seca, as Ordens com maiores frequência de ocorrência foram Hymenoptera, Araneae, Coleoptera, Dermaptera, Orthoptera, Isoptera, Acari, Lithobiomorpha, Diptera, Hemiptera. Através do índice de diversidade de Shannon identificou-se propriedades com maior estabilidade, principalmente quando houve maior diversidade de espécies florestais nos SAFs. O manejo dos SAFs, o clima, a diversidade de espécies florestais e o tamanho das áreas amostradas possivelmente influenciam a diversidade de Ordens da macrofauna
Fungos micorrízicos arbusculares em solo de cerrado nativo e sob diferentes sistemas de integração lavoura/pecuária.
Distribuição de fungos micorrízicos arbusculares em solos de região de cerrado sob sistemas de pastagens.
The Treg/Th17 cell ratio is reduced in the skin lesions of patients with pyoderma gangrenosum.
Feasibility Study of Lense-Thirring Precession in LS I +61303
Very recent analysis of the radio spectral index and high energy observations
have shown that the two-peak accretion/ejection microquasar model applies for
LSI+61303. The fast variations of the position angle observed with MERLIN and
confirmed by consecutive VLBA images must therefore be explained in the context
of the microquasar scenario. We calculate what could be the precessional period
for the accretion disk in LSI+61303 under tidal forces of the Be star
(P_{tidal-forces}) or under the effect of frame dragging produced by the
rotation of the compact object (P_{Lense-Thirring}). P_{tidal-forces}R_{tr}r_g$, where the Bardeen-Petterson effect
should align the midplane of the disk. For this truncated radius of the
accretion disk P_{Lense-Thirring} for a slow rotator results in a few days.
Therefore, Lense-Thirring precession induced by a slowly rotating compact
object could be compatible with the daily variations of the ejecta angle
observed in LSI+61303.Comment: 6 pages, 5 figures, accepted for publication in Astronomy and
Astrophysic
Erratic Jet Wobbling in the BL Lacertae Object OJ287 Revealed by Sixteen Years of 7mm VLBA Observations
We present the results from an ultra-high-resolution 7mm Very Long Baseline
Array (VLBA) study of the relativistic jet in the BL Lacertae object OJ287 from
1995 to 2011 containing 136 total intensity images. Analysis of the image
sequence reveals a sharp jet-position-angle swing by >100 deg. during
[2004,2006], as viewed in the plane of the sky, that we interpret as the
crossing of the jet from one side of the line of sight to the other during a
softer and longer term swing of the inner jet. Modulating such long term swing,
our images also show for the first time a prominent erratic wobbling behavior
of the innermost ~0.4mas of the jet with fluctuations in position angle of up
to ~40 deg. over time scales ~2yr. This is accompanied by highly superluminal
motions along non-radial trajectories, which reflect the remarkable
non-ballistic nature of the jet plasma on these scales. The erratic nature and
short time scales of the observed behavior rules out scenarios such as binary
black hole systems, accretion disk precession, and interaction with the ambient
medium as possible origins of the phenomenon on the scales probed by our
observations, although such processes may cause longer-term modulation of the
jet direction. We propose that variable asymmetric injection of the jet flow;
perhaps related to turbulence in the accretion disk; coupled with hydrodynamic
instabilities, leads to the non-ballistic dynamics that cause the observed
non-periodic changes in the direction of the inner jet.Comment: Accepted for Publication in The Astrophysical Journal. 11 pages, 6
figures, 4 tables. High resolution images on figure 1 and complete tables 1
and 2 may be provided on reques
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