10 research outputs found
Examining Periodic Solar Wind Density Structures Observed in the SECCHI Heliospheric Imagers
We present an analysis of small-scale, periodic, solar-wind density
enhancements (length-scales as small as \approx 1000 Mm) observed in images
from the Heliospheric Imager (HI) aboard STEREO A. We discuss their possible
relationship to periodic fluctuations of the proton density that have been
identified at 1 AU using in-situ plasma measurements. Specifically, Viall,
Kepko, and Spence (2008) examined 11 years of in-situ solar-wind density
measurements at 1 AU and demonstrated that not only turbulent structures, but
also non-turbulent periodic density structures exist in the solar wind with
scale sizes of hundreds to one thousand Mm. In a subsequent paper, Viall,
Spence, and Kasper (2009) analyzed the {\alpha} to proton solar-wind abundance
ratio measured during one such event of periodic density structures,
demonstrating that the plasma behavior was highly suggestive that either
temporally or spatially varying coronal source plasma created those density
structures. Large periodic density structures observed at 1 AU, which were
generated in the corona, can be observable in coronal and heliospheric
white-light images if they possess sufficiently high density contrast. Indeed,
we identify such periodic density structures as they enter the HI field of view
and follow them as they advect with the solar wind through the images. The
smaller periodic density structures that we identify in the images are
comparable in size to the larger structures analyzed in-situ at 1 AU, yielding
further evidence that periodic density enhancements are a consequence of
coronal activity as the solar wind is formed.Comment: 15 pages, 12 figures. The final publication is available at
http://www.springerlink.co
Coding SNPs analysis highlights genetic relationships and evolution pattern in eggplant complexes
[EN] Brinjal (Solanum melongena), scarlet (S. aethiopicum) and gboma (S. macrocarpon) eggplants are three Old World domesticates. The genomic DNA of a collection of accessions belonging to the three cultivated species, along with a representation of various wild relatives, was characterized for the presence of single nucleotide polymorphisms (SNPs) using a genotype-by-sequencing approach. A total of 210 million useful reads were produced and were successfully aligned to the reference eggplant genome sequence. Out of the 75,399 polymorphic sites identified among the 76 entries in study, 12,859 were associated with coding sequence. A genetic relationships analysis, supported by the output of the FastSTRUCTURE software, identified four major sub-groups as present in the germplasm panel. The first of these clustered S. aethiopicum with its wild ancestor S. anguivi; the second, S. melongena, its wild progenitor S. insanum, and its relatives S. incanum, S. lichtensteinii and S. linneanum; the third, S. macrocarpon and its wild ancestor S. dasyphyllum; and the fourth, the New World species S. sisymbriifolium, S. torvum and S. elaeagnifolium. By applying a hierarchical FastSTRUCTURE analysis on partitioned data, it was also possible to resolve the ambiguous membership of the accessions of S. campylacanthum, S. violaceum, S. lidii, S. vespertilio and S. tomentsum, as well as to genetically differentiate the three species of New World Origin. A principal coordinates analysis performed both on the entire germplasm panel and also separately on the entries belonging to sub-groups revealed a clear separation among species, although not between each of the domesticates and their respective wild ancestors. There was no clear differentiation between either distinct cultivar groups or different geographical provenance. Adopting various approaches to analyze SNP variation provided support for interpretation of results. The genotyping-by-sequencing approach showed to be highly efficient for both quantifying genetic diversity and establishing genetic relationships among and within cultivated eggplants and their wild relatives. The relevance of these results to the evolution of eggplants, as well as to their genetic improvement, is discussed.This work has been funded in part by European Unions Horizon 2020 Research and Innovation Programme under grant agreement No 677379 (G2P-SOL project: Linking genetic resources, genomes and phenotypes of Solanaceous crops) and by Spanish Ministerio de Economia, Industria y Competitividad and Fondo Europeo de Desarrollo Regional (grant AGL2015-64755-R from MINECO/FEDER). Funding has also been received from the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives", which is supported by the Government of Norway. This last project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew and implemented in partnership with national and international gene banks and plant breeding institutes around the world. For further information see the project website:http://www.cwrdiversity.org/. Pietro Gramazio is grateful to Universitat Politecnica de Valencia for a pre-doctoral (Programa FPI de la UPV-Subprograma 1/2013 call) contract. Mariola Plazas is grateful to Spanish Ministerio de Economia, Industria y Competitividad for a post-doctoral grant within the Santiago Grisolia Programme (FCJI-2015-24835). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Acquadro, A.; Barchi, L.; Gramazio, P.; Portis, E.; Vilanova Navarro, S.; Comino, C.; Plazas Ávila, MDLO.... (2017). Coding SNPs analysis highlights genetic relationships and evolution pattern in eggplant complexes. PLoS ONE. 12(7). https://doi.org/10.1371/journal.pone.0180774Se018077412
Variabilidade genética e fluxo gênico em populações híbridas e silvestres de pupunha acessada com marcadores RAPD
As populações híbridas de pupunha (Bactris gasipaes Kunth) acumularam variabilidade genética provenientes de raças primitivas ao seu redor, o que deveria aumentar sua variabilidade. Para testar esta hipótese, avaliou-se a variabilidade genética de populações híbridas por meio de marcadores RAPD utilizando 176 plantas mantidas no Banco Ativo de Germoplasma do INPA, Manaus-AM, sendo quatro populações híbridas [Belém (n=26); Manaus (n=38); Iquitos, Peru (n=41); Yurimáguas, Peru (n=41)], duas populações silvestres (B. gasipaes variedade chichagui) tipos 1 (n=21) e 3 (n=7), e duas amostras de espécie afim, B. riparia, e compararam-se os parâmetros genéticos com estudos das raças primitivas. Oito iniciadores RAPD geraram 88 marcadores polimórficos e 11 monomórficos. O teste de replicabilidade apresentou uma similaridade de Dice 0,67, considerado aceitável. A heterozigosidade média das populações híbridas foi 0,34 e o polimorfismo foi 87,9%, maiores que nas silvestres (0,31; 74,7%). O dendrograma das similaridades de Dice não apresentou grupos que representassem claramente as populações híbridas. O fluxo gênico entre Iquitos e Yurimáguas (Nm=12,75) e entre Iquitos e Manaus (Nm=9,47) foi alto, enquanto o fluxo entre Belém e Manaus (Nm=7,72) foi menor que o esperado, possivelmente devido à influência da raça Solimões. O alto valor de heterozigosidade em Manaus (0,31) parece ser resultado da união de duas dispersões após a domesticação: a do oeste amazônico, com Iquitos e Yurimáguas, e a do leste amazônico, com Belém, que se juntam em Manaus. No entanto, essas populações não apresentaram acúmulo de variabilidade genética tão expressiva para diferenciá-las das raças primitivas
Recent advances in psychoneuroimmunology: inflammation in psychiatric disorders
Psychiatric disorders are common and complex and their precise biological underpinnings remain elusive. Multiple epidemiological, molecular, genetic and gene expression studies suggest that immune system dysfunction may contribute to the risk for developing psychiatric disorders including schizophrenia, bipolar disorder, and major depressive disorder. However, the precise mechanisms by which inflammation-related events confer such risk are unclear. In this review, we examine the peripheral and central evidence for inflammation in psychiatric disorders and the potential molecular mechanisms implicated including inhibition of neurogenesis, apoptosis, the HPA-axis, the role of brain-derived neurotrophic factor and the interplay between the glutamatergic, dopaminergic and serotonergic neurotransmitter systems