Perpendicular momentum injection by lower hybrid wave in a tokamak

The injection of lower hybrid waves for current drive into a tokamak affects the profile of intrinsic rotation. In this article, the momentum deposition by the lower hybrid wave on the electrons is studied. Due to the increase in the poloidal momentum of the wave as it propagates into the tokamak, the parallel momentum of the wave increases considerably. The change of the perpendicular momentum of the wave is such that the toroidal angular momentum of the wave is conserved. If the perpendicular momentum transfer via electron Landau damping is ignored, the transfer of the toroidal angular momentum to the plasma will be larger than the injected toroidal angular momentum. A proper quasilinear treatment proves that both perpendicular and parallel momentum are transferred to the electrons. The toroidal angular momentum of the electrons is then transferred to the ions via different mechanisms for the parallel and perpendicular momentum. The perpendicular momentum is transferred to ions through an outward radial electron pinch, while the parallel momentum is transferred through collisions.Comment: 22 pages, 4 figure

Maternal genetic inheritance of red pericarp in the grain of maize

The diversity of colors in the grain of corn is wide, from whites to blacks and including a continuum of various shades of yellows, pinks, reds, purples and blues. The most abundant commercial colors are yellow and white, however other colors have become more important because of the presence of pigments to which are attributed favorable effects as a food. The pigments are also considered natural barriers of the grain against the invasion of pests and diseases in the production fields. The colors of the grain of corn occur in three different parts of the seed: the cover of the grain or pericarp, derived from the maternal tissue, with a diploid genetic content; the endo-sperm, including the aleurone layers that are cells in the grain immediately below the pericarp with a chromosome content of 3n; and the embryo, with a genetic content of 2n. The red color considered in this study is present in the pericarp ignoring possible effects in other tissues of grain and other organs of the plant. In this study, we used materials with colorless or red pericarp, and white or yellow endosperm; with the purpose of describing the type of inheritance of this character in the grain of corn. The results indicated a maternal genetic inheritance with classical complete dominance of the red color of pericarp over the clear or transparent phenotype, where the red color of the grains on ear is determined by the genotype of the mother grain but not by the seed embryo genotypes, which is characterized by uniformity of grain color of the ear. This type of inheritance could be useful in the development of pigmented varieties of higher food quality for humans

Breastfeeding during the COVID-19 pandemic: analysis of the breastmilk antibodies, neutralization capacity and microbiota profile from infected and vaccinated wome

Resumen del póster presentado a las III Jornadas Científicas PTI+ Salud Global, celebradas en el Centro de Ciencias Humanas y Sociales (CCHS), CSIC (Madrid) del 20 al 22 de noviembre de 2023.[Background] Breastmilk is considered the gold standard in infant nutrition and provides bioactive compounds to the neonate, among them antibodies and microbiota. In the context of the COVID- 19 pandemics, there were great concerns about a possible mother-to-infant transfer of SARS-CoV-2, since limited knowledge about the safety of breastfeeding after natural infection or vaccination, as well as the transfer of protective antibodies and their neutralization capacity, was available. Additionally, there are concerns about potential short- and long-term adverse effects of SARS-CoV-2 infection and vaccine-induced changes to the breastmilk microbiome composition, which contributes in shaping the early-life microbiome.[Methods] This study included 60 mothers which had a confirmed SARS-CoV-2 infection and also, 86 mothers vaccinated with mRNA-based (Comirnaty, mRNA-1273) and adenoviral-vectored vaccines (ChAdOx1 nCoV-19) were recruited and breastmilk samples were collected longitudinally from baseline up to 30 days after the second dose at seven or eight time points (depending on vaccine type). In COVID-19 lactating mothers, the presence of SARS-CoV-2 was assessed by RT-qPCR targeting the N1 region of the nucleocapsid gene and the envelope (E) gene. In both studies, the levels of SARS-CoV-2 RBD-specific IgA, IgM and IgG were determined by ELISA. The neutralization capacity was tested using pseudotyped vesicular stomatitis virus carrying either the Wuhan-Hu-1, Delta, or BA.1 Omicron spike proteins. To assess the microbiome composition, DNA from breastmilk samples was extracted and the V3-V4 region of the 16S rRNA gene was sequenced using the MiSeq system of Illumina.[Results] After SARS-CoV-2 infection, no virus-specific RNA was detected in breastmilk samples. Determination of antibody levels in mothers with confirmed SARS-CoV-2 infection showed that 82.9% (58 of 70) of milk samples were positive for at least one of the three tested antibody isotypes. Vaccination elicited also a strong induction of SARS-CoV-2-specific antibodies, which was higher in IgG when compared to COVID-19 convalescent women and was strongly increased after the 2nd dose. mRNA-based vaccines induced higher IgG and IgA levels when compared to the adenovirus- vectored vaccine, and women with previous virus exposure increased their IgG antibodies levels after the first dose to a similar level observed in vaccinated women after the second dose. When assessing the neutralization capacity, natural infection resulted in higher neutralizing titers that correlated positively with levels of SARS-CoV-2-specific immunoglobulin A in breastmilk. Breastmilk samples from COVID-19 convalescent mothers infected during the first wave (Wuhan-Hu-1 strain) neutralized less effectively Omicron BA.1 than the Wuhan-Hu-1 variant. In addition, significant differences in the capacity to produce neutralizing antibodies were observed between both mRNA- based vaccines and the adenovirus-vectored ChAdOx1 COVID-19 vaccine. First results of the analysis of the breastmilk microbiome found no significant differences in the mean diversity of species (alpha-diversity) after natural SARS-CoV-2 infection, whereas some specific bacterial groups were increased (e.g. Enterobacteriaceae).[Conclusions] Overall, our results indicate that breastmilk from naturally infected women or those vaccinated with mRNA-based vaccines contain SARS-CoV-2 neutralizing antibodies that could potentially provide protection to breastfed infants from infection.Peer reviewe

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

Tomato breeding resistance to late blight in Western Mexico

Late blight caused by Phytophthora infestans is one of the most devastating diseases of tomato cultivation in western Mexico. Annually large sums of money are spent for its control, which significantly increases production costs. In the group of tomato breeding research at the University Center of Biological and Agricultural Sciences located in Zapopan, Jalisco, Mexico, we have worked for some time in screening sources of resistance to P. infestans and other pathogens. We are working with wild species of Solanum lycopersicon var. cerasiforme collected in the western region of Mexico and materials generated through crosses and backcrosses between wild materials and open pollinated cultivars. We have selected 9 breeding lines which were tested under natural infection of P. infestans both in field and greenhouse. The reaction of genotypes was evaluated following the methodology calculating the area under the curve of the disease, under laboratory conditions, using detached leaf inoculation and compared against 'LA 2533' resistant and 'Rio Grande' and 'San Marzano' susceptible cultivars. Breeding lines have proven resistant, statistically equal or superior to the 'LA 2533' in field and laboratory tests using highly virulent strains of P. infestans collected in the Toluca Valley, Mexico State

Tomato breeding resistance to late blight in Western Mexico

Late blight caused by Phytophthora infestans is one of the most devastating diseases of tomato cultivation in western Mexico. Annually large sums of money are spent for its control, which significantly increases production costs. In the group of tomato breeding research at the University Center of Biological and Agricultural Sciences located in Zapopan, Jalisco, Mexico, we have worked for some time in screening sources of resistance to P. infestans and other pathogens. We are working with wild species of Solanum lycopersicon var. cerasiforme collected in the western region of Mexico and materials generated through crosses and backcrosses between wild materials and open pollinated cultivars. We have selected 9 breeding lines which were tested under natural infection of P. infestans both in field and greenhouse. The reaction of genotypes was evaluated following the methodology calculating the area under the curve of the disease, under laboratory conditions, using detached leaf inoculation and compared against 'LA 2533' resistant and 'Rio Grande' and 'San Marzano' susceptible cultivars. Breeding lines have proven resistant, statistically equal or superior to the 'LA 2533' in field and laboratory tests using highly virulent strains of P. infestans collected in the Toluca Valley, Mexico State

Relationships among twelve genotypes of roselle (Hibiscus sabdariffa L.) cultivated in western Mexico

The aim of this study was to characterize agromorphological and molecular relationships between twelve genotypes of roselle (Hibiscus sabdariffa L.) grown in western Mexico. Variables related to crop yield and management at two localities were used for agromorphological characterization. Data were analyzed using principal component analysis. The first four components explained 75.77% of the variation between genotypes. Molecular characterization was conducted using the inverse sequence-tagged repeat marker, which separated the 12 genotypes into two main groups. Three of the genotypes that grouped together at the molecular level had a similar leaf phenotypic characteristic (the number of lobes), which differed from that of the other genotypes. Variation between genotypes was evident in respect of molecular variables, which were used as genetic markers to distinguish between genotypes. Grouping of genotypes according to agromorphological variables, which reflect the response of a genotype to the environment, yielded similar results to molecular grouping. Genetic structure analysis indicated that the China, Fresa, Diamante, and Gigante genotypes probably share a common origin. © 2011 Elsevier B.V

Climatic adaptation and ecological descriptors of 42 Mexican maize races

To better understand the range of adaptation of maize (Zea mays L.) landraces, climatic adaptation intervals of 42 Mexican maize races were determined. A database of 4161 maize accessions was used to characterize altitudinal and climatic conditions where the 42 maize races grow, yielding ecological descriptors for each race. Using the geographical coordinates of the collection sites of each accession, their climatic conditions were characterized using the geographic information system IDRISI and a national environmental information system. Analyses of variance and cluster analyses of the racial ecological descriptors were performed to determine possible environmental groupings of the races. We found a very high level of variation among and within Mexican maize races for climate adaptation and ecological descriptors. The general overall climatic ranges for maize were 0 to 2900 m of altitude, 11.3 to 26.6°C annual mean temperature, 12.0 to 29.1°C growing season mean temperature, 426 to 4245 mm annual rainfall, 400 to 3555 mm growing season rainfall, and 12.46 to 12.98 h mean growing season daylength. These climatic ranges of maize surpass those from its closest relative, teosinte (Z. mays ssp. parviglumis litis and Doebley), indicating that maize has evolved adaptability beyond the environmental range in which ancestral maize was first domesticated. © Crop Science Society of America. All rights reserved