Experiments on the Preparation of Aminohydroxynaphthoic Acids

Some suggested methods for the preparation of aminohydroxynaphthoic acids have been investigated. The main part of the research was devoted to the preparation of those having the -NH2 group in the 2-position, and the particular one desired was the 2-amino-5-hydroxy-7-naphthoic acid. The scheme, outlined on pages 13 and 14, shows that the -OH group was to be introduced by sulphonation and subsequent alkali fusion of 2:7-aminonaphthoic acid. Consequently the first consideration was the preparation of 2:7-aminonaphthoic acid. The formation of 2:7-aminonaphthonitrile by replacement of -SO3H by -CN by the dry distillation of 2:7-aminonaphthalene sulphonic acid with KCN and K4Fe(CN)6 gave very poor yields, insufficient for the subsequent series of reactions, while fusion with KCN under pressure eliminated the -SO3H group. The diazotisation of 2:7-aminonaphthol was successfully accomplished by the usual Greiss reaction in the presence of a large excess of HCl; also after the method of Hodgson & Walker, and that of Schoutissen, but attempts to form the 2:7-cyanonaphthol by the Sandmeyer reaction and various modifications of same failed due to the preference of the diazo compound to couple with itself. The diazotisation of 2:7-diaminonaphthalene was accomplished using a modification of the method of Schoutissen, but attempts to form the 2:7-aminonaphthonitrile failed. 2:7-Aminonaphthoic acid was synthesised from 2:7-aminonaphthalene sulphonic acid by the series of reactions outlined on page 82 and described on pages 120-136, and successfully sulphonated but the yield of sulphonic acid was poor. The same result was obtained with chlorosulphuric acid. Sulphonation of the acetyl derivative gave excellent yields, but isomers were present and various attempts to separate them were unsuccessful, while conversion to the aminohydroxynaphthoic acids by alkali fusion yielded oxidation products. Estimation of the alpha-SO3H groups in the sulphonation mixture gave 60%. It would appear, judging from results on page 125, that about 40% of the sulphonic mixture contains the -SO3H group in the 6-position. The preparation of 1:2:7- and 1:2:6-aminohydroxynaphthoic acids was accomplished by method 1. They were obtained as the hydrochlorides since the free bases oxidise very rapidly in the air. The action of nitrous acid on 2:7- and 2:6-hydroxy-naphthoic acids gave highly coloured products containing no nitrogen. A table of properties is given on page 189

Characterization of Growth Morphology and Pathology, and Draft Genome Sequencing of Botrytis fabae, the Causal Organism of Chocolate Spot of Faba Bean (Vicia faba L.)

Chocolate spot is a major fungal disease of faba bean caused by the ascomycete fungus, Botrytis fabae. B. fabae is also implicated in botrytis gray mold disease in lentils, along with B. cinerea. Here we have isolated and characterized two B. fabae isolates from chocolate spot lesions on faba bean leaves. In plant disease assays on faba bean and lentil, B. fabae was more aggressive than B. cinerea and we observed variation in susceptibility among a small set of cultivars for both plant hosts. Using light microscopy, we observed a spreading, generalized necrosis response in faba bean toward B. fabae. In contrast, the plant response to B. cinerea was localized to epidermal cells underlying germinated spores and appressoria. In addition to the species characterization of B. fabae, we produced genome assemblies for both B. fabae isolates using Illumina sequencing. Genome sequencing coverage and assembly size for B. fabae isolates, were 27x and 45x, and 43.2 and 44.5 Mb, respectively. Following genome assembly and annotation, carbohydrate-active enzyme (CAZymes) and effector genes were predicted. There were no major differences in the numbers of each of the major classes of CAZymes. We predicted 29 effector genes for B. fabae, and using the same selection criteria for B. cinerea, we predicted 34 putative effector genes. For five of the predicted effector genes, the pairwise dN/dS ratio between orthologs from B. fabae and B. cinerea was greater than 1.0, suggesting positive selection and the potential evolution of molecular mechanisms for host specificity in B. fabae. Furthermore, a homology search of secondary metabolite clusters revealed the absence of the B. cinerea phytotoxin botrydial and several other uncharacterized secondary metabolite biosynthesis genes from B. fabae. Although there were no obvious differences in the number or proportional representation of different transposable element classes, the overall proportion of AT-rich DNA sequence in B. fabae was double that of B. cinerea

An update to the MARVEL data set and ExoMol line list for ¹²C₂

The spectrum of dicarbon (C_{2}) is important in astrophysics and for spectroscopic studies of plasmas and flames. The C_{2} spectrum is characterized by many band systems with new ones still being actively identified; astronomical observations involve eight of these bands. Recently, Furtenbacher et al. presented a set of 5699 empirical energy levels for {12}^C_{2}, distributed among 11 electronic states and 98 vibronic bands, derived from 42 experimental studies and obtained using the MARVEL (Measured Active Rotational-Vibrational Energy Levels) procedure. Here, we add data from 13 new sources and update data from 5 sources. Many of these data sources characterize high-lying electronic states, including the newly detected 3 {3}^Π_{g} state. Older studies have been included following improvements in the MARVEL procedure that allow their uncertainties to be estimated. These older works in particular determine levels in the C {1}^Π_{g} state, the upper state of the insufficiently characterized Deslandres–d’Azambuja (C {1}^Π_{g}–A {1}^Π_{u}) band. The new compilation considers a total of 31 323 transitions and derives 7047 empirical (MARVEL) energy levels spanning 20 electronic and 142 vibronic states. These new empirical energy levels are used here to update the 8states C_{2} ExoMol line list This updated line list is highly suitable for high-resolution cross-correlation studies in astronomical spectroscopy of, for example, exoplanets, as 99.4 per cent of the transitions with intensities over 10^{−18} cm molecule^{−1} at 1000 K have frequencies determined by empirical energy levels

Phonon drag thermopower and weak localization

Previous experimental work on a two-dimensional (2D) electron gas in a Si-on-sapphire device led to the conclusion that both conductivity and phonon drag thermopower $S^g$ are affected to the same relative extent by weak localization. The present paper presents further experimental and theoretical results on these transport coefficients for two very low mobility 2D electron gases in $\delta-$doped GaAs/Ga$_x$Al$_{1-x}$As quantum wells. The experiments were carried out in the temperature range 3-7K where phonon drag dominates the thermopower and, contrary to the previous work, the changes observed in the thermopower due to weak localization were found to be an order of magnitude less than those in the conductivity. A theoretical framework for phonon drag thermopower in 2D and 3D semiconductors is presented which accounts for this insensitivity of $S^g$ to weak localization. It also provides transparent physical explanations of many previous experimental and theoretical results.Comment: 19 page Revtex file, 3 Postscript figur

Weak localization effect on thermomagnetic phenomena

The quantum transport equation (QTE) is extended to study weak localization (WL) effects on galvanomagnetic and thermomagnetic phenomena. QTE has many advantages over the linear response method (LRM): (i) particle-hole asymmetry which is necessary for the Hall effect is taken into account by the nonequilibrium distribution function, while LRM requires expansion near the Fermi surface, (ii) when calculating response to the temperature gradient, the problem of WL correction to the heat current operator is avoided, (iii) magnetic field is directly introduced to QTE, while the LRM deals with the vector potential and and special attention should be paid to maintain gauge invariance, e.g. when calculating the Nernst effect the heat current operator should be modified to include the external magnetic field. We reproduce in a very compact form known results for the conductivity, the Hall and the thermoelectric effects and then we study our main problem, WL correction to the Nernst coefficient (transverse thermopower).Comment: 20 pages 2 figure

Transposable element genomic fissuring in Pyrenophora teres is associated with genome expansion and dynamics of host-pathogen genetic interactions

Syme, Martin, Wyatt, Lawrence, Muria-Gonzalez, Friesen and Ellwood. Pyrenophora teres, P. teres f. teres (PTT) and P. teres f. maculata (PTM) cause significant diseases in barley, but little is known about the large-scale genomic differences that may distinguish the two forms. Comprehensive genome assemblies were constructed from long DNA reads, optical and genetic maps. As repeat masking in fungal genomes influences the final gene annotations, an accurate and reproducible pipeline was developed to ensure comparability between isolates. The genomes of the two forms are highly collinear, each composed of 12 chromosomes. Genome evolution in P. teres is characterized by genome fissuring through the insertion and expansion of transposable elements (TEs), a process that isolates blocks of genic sequence. The phenomenon is particularly pronounced in PTT, which has a larger, more repetitive genome than PTM and more recent transposon activity measured by the frequency and size of genome fissures. PTT has a longer cultivated host association and, notably, a greater range of host-pathogen genetic interactions compared to other Pyrenophora spp., a property which associates better with genome size than pathogen lifestyle. The two forms possess similar complements of TE families with Tc1/Mariner and LINE-like Tad-1 elements more abundant in PTT. Tad-1 was only detectable as vestigial fragments in PTM and, within the forms, differences in genome sizes and the presence and absence of several TE families indicated recent lineage invasions. Gene differences between P. teres forms are mainly associated with gene-sparse regions near or within TE-rich regions, with many genes possessing characteristics of fungal effectors. Instances of gene interruption by transposons resulting in pseudogenization were detected in PTT. In addition, both forms have a large complement of secondary metabolite gene clusters indicating significant capacity to produce an array of different molecules. This study provides genomic resources for functional genetics to help dissect factors underlying the host-pathogen interactions

Flattening of Single-Particle Spectra in Strongly Correlated Electron Systems and the Violation of the Wiedemann-Franz Law

The renormalization of the Wiedemann-Franz (WF) ratio in strongly correlated electron systems is analyzed within the Landau quasiparticle picture. We demonstrate that the WF law is violated: (i) at the quantum critical point, where the effective mass diverges, and (ii) beyond a point of fermion condensation, where the single-particle spectrum $\epsilon(p)$ becomes flat. Results of the analysis are compared with available experimental data.Comment: 6 pages, 5 figures, added reference

The development of private bore-wells as independent water supplies: challenges for water utilities in France and Australia

International audienceIn developed countries, a number of factors are leading a growing number of households to drill private boreholes as independent water supplies. This chapter describes this phenomenon based on two case studies conducted in Southern France and Western Australia. It shows that, while the development of private wells was encouraged by the authorities in Perth, it is a major source of environmental, public health, economic and social concern for French water utilities. Household's motivations to develop independent supply are then investigated. We finaly discuss how water utilities need to adapt their management practices (setting tariffs, demand forecasting and resource protection) to take into account this phenomenon

Pathways to health: a framework for health-focused research and practice

Public health research and practice is faced with three problems: 1) a focus on disease instead of health, 2) consideration of risk factor/disease relationships one at a time, and 3) attention to individuals with limited regard for the communities in which they live. We propose a framework for health-focused research and practice. This framework encompasses individual and community pathways to health while incorporating the dynamics of context and overall population vulnerability and resilience. Individual pathways to health may differ, but commonalities will exist. By understanding these commonalities, communities can work to support health-promoting pathways in addition to removing barriers. The perspective afforded by viewing health as a dynamic process instead of as a collection of risk factors and diseases expands the number of approaches to improving health globally. Using this approach, multidisciplinary research teams working with active community participants have the potential to reshape health and intervention sciences