Effects of climate change on productivity of cereals and legumes; model evaluation of observed year-to-year variability of the CO2 response

The effect of elevated [CO₂] on the productivity of spring wheat, winter wheat and faba bean was studied in experiments in climatized crop enclosures in the Wageningen Rhizolab in 1991–93. Simulation models for crop growth were used to explore possible causes for the observed differences in the CO₂ response. Measurements of the canopy gas exchange (CO₂ and water vapour) were made continuously from emergence until harvest. At an external [CO₂] of 700 μmol mol^?1 Maximum Canopy CO₂ Exchange Rate (CCERmax) at canopy closure was stimulated by 51% for spring wheat and by 71% for faba bean. At the end of the growing season, above ground biomass increase at 700 μmol mol^?1 was 58% (faba bean), 35% (spring wheat) and 19% (winter wheat) and the harvest index did not change. For model exploration, weather data sets for the period 1975-88 and 1991–93 were used, assuming adequate water supply and [CO₂] at 350 and 700 μmol mol^?1. For spring wheat the simulated responses (35–50%) were at the upper end of the experimental results. In agreement with experiments, simulations showed smaller responses for winter wheat and larger responses for faba bean. Further model explorations showed that this differential effect in the CO₂ response may not be primarily due to fundamental physiological differences between the crops, but may be at least partly due to differences in the daily air temperatures during comparable stages of growth of these crops. Simulations also showed that variations between years in CO₂ response can be largely explained by differences in weather conditions (especially temperature) between growing seasons.     

Peak fitting in 2D <Superscript>1</Superscript>H–<Superscript>13</Superscript>C HSQC NMR spectra for metabolomic studies

A modified Lorentzian distribution function is used to model peaks in two-dimensional (2D) ¹H–¹³C heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectra. The model fit is used to determine accurate chemical shifts from genuine signals in complex metabolite mixtures such as blood. The algorithm can be used to extract features from a set of spectra from different samples for exploratory metabolomics. First a reference spectrum is created in which the peak intensities are given by the median value over all samples at each point in the 2D spectra so that ¹H–¹³C correlations in any spectra are accounted for. The mathematical model provides a footprint for each peak in the reference spectrum, which can be used to bin the ¹H–¹³C correlations in each HSQC spectrum. The binned intensities are then used as variables in multivariate analyses and those found to be discriminatory are rapidly identified by cross referencing the chemical shifts of the bins with a database of ¹³C and ¹H chemical shift correlations from known metabolites.     

Utilization by the isolated perfused rat liver of N-acetyl-D-[1-14C]galactosamine and N-[3H]acetyl-D-galactosamine for the biosynthesis of glycoproteins.

The isolated perfused rat liver system has been used to monitor the utilization of N-[3H]acetyl-D-galactosamine and N-acetyl-D-[1-14C]galactosamine for the biosynthesis of radiolabelled glycoproteins, which are subsequently secreted into the plasma. Both radiolabels appear in a number of different glycoproteins, predominantly as sialic acid and N-acetylglucosamine. The ratio of labelled sialic acid to labelled N-acetylglucosamine varies for different glycoproteins, but the bulk of N-acetyl-D-galactosamine is incorporated without deacetylation.     

Hepatic microsomal warfarin metabolism in warfarin-resistant and susceptible mouse strains: influence of pretreatment with cytochrome P-450 inducers

In the present paper, the heterogeneity of hepatic cytochrome P-450 isoenzymes in the mouse has been probed, using warfarin as the substrate. Both sex and strain differences in the in vitro microsomal metabolism of warfarin have been investigated in male and female warfarin-resistant HC and warfarin-susceptible LAC-grey mouse strains. Animals were either untreated or treated with the cytochrome P-450 inducers phenobarbitone, beta-napthoflavone or clofibrate. In both sexes and strains of mice, metabolism of warfarin was stereoselective in favour of the R(+) enantiomer. However, regioselectively was different in both strains and sexes of untreated animals. After pretreatment with phenobarbitone, increases in the rate of formation of 4' and 7-hydroxy R(+) and S(-) warfarin metabolites in HC mice were observed, compared with untreated animals. In LAC-grey mice increases in 4'-, 6-, 7- and 8-hydroxy R(+) and S(-) warfarin metabolites were noted, compared with untreated animals. This data indicated that different amounts or forms of cytochrome P-450s were responsible for warfarin metabolism after phenobarbitone treatment in the two strains. Pretreatment of animals with beta-napthoflavone resulted in significant decreases in the rat of R(+) warfarin metabolism in both strains and sexes of mice indicating that the beta-naphthoflavone-inducible cytochrome P-450 isoenzymes were less active in the metabolism of warfarin, as compared to the uninduced isoenzymes. In addition, the cytochrome P-450 isoenzyme composition in the two mouse strains was different after clofibrate pretreatment, as reflected in reduced levels of some warfarin metabolites and a reduced total metabolism of warfarin, consistent with the narrow substrate specificity of clofibrate-induced cytochrome P450IVA1 for fatty acid hydroxylation. Accordingly, it is clear that both the basal and xenobiotic inducible hepatic cytochrome P-450 isoenzymes in warfarin-resistant and susceptible mice are different and therefore have implications for the in vivo disposition of warfarin.     

Galvechelone lopezmartinezae gen. et sp. nov., a new cryptodiran turtle in the Lower Cretaceous of Europe

Abstract: The Spanish town of Galve (Teruel) is notable because of the abundance of Upper Jurassic and, especially, Lower Cretaceous vertebrates recorded there. Although most groups have been studied in detail, information on turtles is very limited even though the material is relatively abundant. So far, no turtle taxa have been identified at the generic level. The only Lower Cretaceous articulated specimen from Galve is analysed here. It is identified as a representative of Cryptodira, Galvechelone lopezmartinezae gen. et sp. nov. Galvechelone lopezmartinezae is determined as a taxon belonging to the node that groups the turtles traditionally assigned to ‘Macrobaenidae’ and ‘Sinemydidae’, and other taxa such as the members of Panchelonioidea. This node, very abundant in the Lower Cretaceous of Asia, and with a broad subsequent distribution, has recently been recognized in the Lower Cretaceous of Europe. The diversity of basal members of Eucryptodira in the European Late Jurassic (represented by Thalassemydidae, Plesiochelyidae and Eurysternidae) was high. Owing to a relative scarcity of well‐preserved early Cretaceous turtles from Europe, the knowledge of this group of reptiles is limited. The study of the new turtle from Galve, together with the recently described Hoyasemys jimenezi, and the recently completed review of the enigmatic Chitracephalus dumonii demonstrate that members of the cryptodiran node grouping ‘Macrobaenidae’, ‘Sinemydidae’ and Panchelonioidea were also very diverse in this period.     

Improving ability to identify malaria and correctly use chloroquine in children at household level in Nakonde District, Northern Province of Zambia

BACKGROUND: This study investigated causes of malaria and how cases were managed at household level, in order to improve the ability to identify malaria and ensure correct use of chloroquine. It was conducted in Nakonde District, Northern Province of Zambia, between 2000 and 2001. Nakonde district is in a hyperendemic malaria province, where Plasmodium falciparum is predominant. The district has a total population of 153, 548 people, the majority of whom are peasant farmers. The main aim of the post intervention survey was to establish the proportion of caretakers of children five years and below, who were able to identify simple and severe malaria and treat it correctly using chloroquine in the home. METHODS: A baseline survey was conducted in five wards divided into intervention and control.Intervention and control wards were compared. Village health motivators and vendors were identified and trained in three intervention wards, as a channel through which information on correct chloroquine dose could be transmitted. A total of 575 carers, who were 15 years old and above and had a child who had suffered from malaria 14 days before the survey commenced, were interviewed. The two control wards received no intervention. 345 caretakers were from the intervention wards, while 230 came from the control wards. Identification of malaria and correct use of anti-malarial drugs was assessed in terms of household diagnosis of malaria in children under five years, type and dose of anti-malarial drugs used, self medication and the source of these anti-malarials. RESULTS: The majority of respondents in the study were females (81%). Chloroquine was the most frequently used anti-malarial (48.5%) in both the intervention and control wards. There was no difference between the intervention and control wards at pre-intervention (P = 0.266 and P = 0.956), in the way mothers and other caretakers identified simple and severe malaria. At baseline, knowledge on correct chloroquine dosage in the under five children was comparable between intervention and control wards. Post-intervention revealed that mothers and other caretakers were 32% and 51%, respectively, more likely to identify simple and severe malaria. There was a 60% increase on correct chloroquine dosage in all age groups among carers living in post-intervention wards. CONCLUSION: Compliance with standard therapeutic doses and correct identification of malaria was poorest in control wards, where no motivators and vendors were trained.     

Towards a comprehensive view of the primary structure of venom proteins from the parasitoid wasp Pimpla hypochondriaca

Venom from the parasitoid wasp Pimpla hypochondriaca has potent in vivo activity against insect haemocytes and disrupts host immune responses. Using hybridisation techniques, and more recently random sequence analysis, we had previously identified cDNAs encoding 10 venom proteins from this wasp and deduced their primary structures. We have now extended the random sequence analysis and discovered a further nine cDNAs encoding proteins with predicted signal sequences. The mature proteins were calculated to have masses of between 4 and 22 kDa. Post-signal sequence residues predicted from the cDNAs matched those derived by Edman degradation from venom proteins separated using gel filtration and reverse phase chromatography, confirming that the cloned cDNAs encode proteins which are secreted into the venom sac. Proteins containing at least six cysteine residues were abundant and seven of these cysteine-rich venom proteins, cvp1-7, were identified. The sequences of some of these proteins were similar, or contained similar cysteine arrangements, to Kunitz type protease inhibitors, pacifastin, the trypsin inhibitor domain protein family, atracotoxin and omega-conotoxin, respectively, which occur in a diverse range of animals including spiders, molluscs, humans and grasshoppers. Two small venom proteins, svp1 and svp2, as well as cvp7 did not have similar sequences to proteins in the GenBank protein database suggesting they may be highly specialised venom components. The random sequencing approach has provided a rapid means of determining the primary structure of the majority of Pimpla hypochondriaca venom proteins.     

Combined prime-boost vaccination against tick-borne encephalitis (TBE) using a recombinant vaccinia virus and a bacterial plasmid both expressing TBE virus non-structural NS1 protein

Background  

Heterologous prime-boost immunization protocols using different gene expression systems have proven to be successful tools in protecting against various diseases in experimental animal models. The main reason for using this approach is to exploit the ability of expression cassettes to prime or boost the immune system in different ways during vaccination procedures. The purpose of the project was to study the ability of recombinant vaccinia virus (VV) and bacterial plasmid, both carrying the NS1 gene from tick-borne encephalitis (TBE) virus under the control of different promoters, to protect mice against lethal challenge using a heterologous prime-boost vaccination protocol.     

Trichoderma spp. and Bacillus spp. as growth promoters in maize (Zea mays L.)

Microbes that are beneficial to plants are used to enhance the crop growth, yield and are alternatives to chemical fertilizers. Trichoderma and Bacillus are the predominant plant growth-promoting fungi and bacteria. The objective of this study was select, characterize, and evaluate isolates of Trichoderma spp. and Bacillus spp. native from the northern region of Sinaloa, Mexico, and assess their effect on growth promotion in maize (Zea mays L.). In greenhouse conditions, four Trichoderma isolates and twenty Bacillus isolates, as well as two controls, were tested in a completely randomized design with three replicates. We selected the two best strains of Trichoderma and Bacillus: TB = Trichoderma asperellum, TF = Trichoderma virens, B14 = Bacillus cereus sensu lato and B17 = Bacillus cereus, which were evaluated in the field in a completely randomized blocks in factorial arrangement design with three replicates applying different rates of nitrogen fertilizer (0, 150 kg N/ha, and 300 kg N/ha). Treatments 5 (B17 = B. cereus) and 11 (TF = T. virens) both fertilized with 150 kg N/ha showed similar yields and they did not reveal significant differences from the treatments fertilized with 300 kg N/ha. This indicated that treatment 5 (B17= B. cereus with 150 kg N/ha) and treatment 11 (TF= T. virens with 150 kg N/ha) were efficient as growth promoters, by not showing significant differences in root volume and dry weight of foliage. The results indicated a reduction of 50% in the rate of nitrogen to fertilizer required for maize (Zea mays L.) crops. These microorganisms Trichoderma and Bacillus could be an alternative to reduce the use of chemical fertilizers in maize.