A fuselage/tank structure study for actively cooled hypersonic cruise vehicles, summary

A detailed analytical study was made to investigate the effects of fuselage cross section (circular and elliptical) and the structural arrangement (integral and nonintegral tanks) on aircraft performance. The vehicle was a 200 passenger, liquid hydrogen fueled Mach 6 transport designed to meet a range goal of 9.26 Mn (5000 NM). A variety of trade studies were conducted in the area of configuration arrangement, structural design, and active cooling design in order to maximize the performance of each of three point design aircraft: (1) circular wing-body with nonintegral tanks, (2) circular wing-body with integral tanks and (3) elliptical blended wing-body with integral tanks. Aircraft range and weight were used as the basis for comparison. The resulting design and performance characteristics show that the blended body integral tank aircraft weights the least and has the greatest range capability, however, producibility and maintainability factors favor nonintegral tank concepts

An inventory of aeronautical ground research facilities. Volume 3: Structural

An inventory of test facilities for conducting acceleration, environmental, impact, structural shock, load, heat, vibration, and noise tests is presented. The facility is identified with a description of the equipment, the testing capabilities, and cost of operation. Performance data for the facility are presented in charts and tables

An inventory of aeronautical ground research facilities. Volume 1: Wind tunnels

A survey of wind tunnel research facilities in the United States is presented. The inventory includes all subsonic, transonic, and hypersonic wind tunnels operated by governmental and private organizations. Each wind tunnel is described with respect to size, mechanical operation, construction, testing capabilities, and operating costs. Facility performance data are presented in charts and tables

Mining grapevine downy mildew susceptibility genes: A resource for genomics-based breeding and tailored gene editing

Several pathogens continuously threaten viticulture worldwide. Until now, the investigation on resistance loci has been the main trend to understand the interaction between grapevine and the mildew causal agents. Dominantly inherited gene-based resistance has shown to be race-specific in some cases, to confer partial immunity, and to be potentially overcome within a few years since its introgression. Recently, on the footprint of research conducted in Arabidopsis, putative genes associated with downy mildew susceptibility have been discovered also in the grapevine genome. In this work, we deep-sequenced four putative susceptibility genes\u2014namely VvDMR6.1, VvDMR6.2, VvDLO1, VvDLO2\u2014in 190 genetically diverse grapevine genotypes to discover new sources of broad-spectrum and recessively inherited resistance. Identified Single Nucleotide Polymorphisms were screened in a bottleneck analysis from the genetic sequence to their impact on protein structure. Fifty-five genotypes showed at least one impacting mutation in one or more of the scouted genes. Haplotypes were inferred for each gene and two of them at the VvDMR6.2 gene were found significantly more represented in downy mildew resistant genotypes. The current results provide a resource for grapevine and plant genetics and could corroborate genomic-assisted breeding programs as well as tailored gene editing approaches for resistance to biotic stresses

Exploring the G-quadruplex binding and unwinding activity of the bacterial FeS helicase DinG

Despite numerous reports on the interactions of G-quadruplexes (G4s) with helicases, systematic analysis addressing the selectivity and specificity of each helicase towards a variety of G4 topologies are scarce. Among the helicases able to unwind G4s are those containing an iron-sulphur (FeS) cluster, including both the bacterial DinG (found in E. coli and several pathogenic bacteria) and the medically important eukaryotic homologues (XPD, FancJ, DDX11 and RTEL1). We carried out a detailed study of the interactions between the E. coli DinG and a variety of G4s, by employing physicochemical and biochemical methodologies. A series of G4-rich sequences from different genomic locations (promoter and telomeric regions), able to form unimolecular G4 structures with diverse topologies, were analyzed (c-KIT1, KRAS, c-MYC, BCL2, Tel23, T30695, Zic1). DinG binds to most of the investigated G4s with little discrimination, while it exhibits a clear degree of unwinding specificity towards different G4 topologies. Whereas previous reports suggested that DinG was active only on bimolecular G4s, here we show that it is also able to bind to and resolve the more physiologically relevant unimolecular G4s. In addition, when the G4 structures were stabilized by ligands (Pyridostatin, PhenDC3, BRACO-19 or Netropsin), the DinG unwinding activity decreased and in most cases was abolished, with a pattern that is not simply explained by a change in binding affinity. Overall, these results have important implications for the biochemistry of helicases, strongly suggesting that when analysing the G4 unwinding property of an enzyme, it is necessary to investigate a variety of G4 substrates

Breeding for grapevine downy mildew resistance via gene editing

Downy mildew (DM) caused by the oomycete Plasmopara viticola ranks in the top diseases affecting grapevine (Vitis vinifera L.) cultivation and its control requires every year a large use of fungicides. The Farm to Fork strategy newly promoted by the EU aims to accelerate the transition to a sustainable food system and has set very ambitious targets including the reduction by 50% of the use and risk of pesticides by 2030. The introduction of disease-tolerant grapevine varieties or clones clearly represents a step forward to reach this goal. The recent advent of new breeding tools such as genome editing and cis-genesis offers a great opportunity to obtain resistant plants with higher precision and speed than by conventional breeding, either by knocking down susceptibility genes or by introducing known resistance-genes in commercial cultivars. Based on reports in other crops, the family of Downy Mildew Resistant 6 (DMR6) and DMR6-like oxygenases (DLOs) are candidate susceptibility genes for the control of DM resistance in V. vinifera. Deep-sequencing the putative susceptibility genes in 190 genetically diverse grapevine genotypes identified several Single Nucleotide Polymorphisms then screened for their impact on protein structure/function and association with DM resistant genotypes. Gene expression and gene network analysis suggested that grapevine DMR6 and DLO genes have distinct functions, and that VviDMR6-1 is co-regulated with several Pathogenesis-related genes. Based on this evidence, we generated a large collection of DMR6-1 and DMR6-2 single and double knock-out mutants in multiple grapevine cultivars and evaluated their resistance to DM. Phenotypic resistance data upon artificial infection are being collected and will be presented here. In parallel, we also developed a new DNA-free gene editing methodology and obtained non-transgenic and non-chimeric edited grapevine plants regenerated from a single cell