Strategies for educational action to meet veterinary medicine's role in biodefense and public health

It is clear that the profession is not well prepared to respond to society's needs in bio-defense and public health. The imperatives that face the veterinary profession, as emphasized by the agenda for action conference deliberations that are reported in this issue of the journal, require action on many fronts, but possibly none more essential than to address how veterinary education needs to change to meet these challenges. Addressing these needs, participants at the agenda for action conference met in groups of 30 to 50 to shape approaches that would address these key questions. The 161 participants were broadly representative of government, private practice, corporate practice, organized veterinary medicine, and academia (Appendix A). Reported here are the results of those deliberations, with each of the seven sections written up by the discussion leader. Included in the participants were 20 students, representative of eight different veterinary colleges, who both participated in the group discussions and have presented their own report.     

Apigenin di-C-glycosides (ACG) content and composition in grains of bread wheat (Triticum aestivum) and related species

Apigenin di-C-glycosides (ACGs) are present in the grain of bread wheat and other related cereals primarily as one or two sets of Wesseley-Moser isomers containing either arabinose and glucose (ACG1) or arabinose and galactose (ACG2) on the A ring of apigenin. These compounds may contribute to the yellow colour of wheat-based products made under alkaline conditions and in addition, have possible roles in a number of plant physiology processes and human health. The aims of this investigation were to survey genetic variation for ACG content and composition in hexaploid bread wheat (Triticum aestivum L.) and to examine ACGs in the putative progenitors of hexaploid wheat and available genetic stocks as a first step towards understanding the mechanisms involved in their biosynthesis and genetic control. Substantial variation in both grain ACG content and the ratio, ACG1/ACG2, were identified within bread wheat cultivars and related species. Genotype controlled the major portion of the variation. ACG content appeared to be a multigenic trait whereas variation in ACG1/ACG2 was associated with a limited number of chromosomes, in particular chromosomes 1B, 7B and 7D. The results suggest that it should be possible to manipulate both ACG content and composition traits through breeding.     

Inheritance of late maturity α-amylase in wheat

Summary Two wheat cultivars that consistently show high levels of grain -amylase at harvest ripeness, in the absence of preharvest sprouting, were crossed with a control, low -amylase cultivar, and F₁, F₂ and BC₁ populations were developed. Grain of these populations was analysed for -amylase activity at harvest ripeness. Distribution and segregation patterns were consistent with control at a single locus with high -amylase the recessive allele. This mode of inheritance would make it extremely difficult to differentiate homozygous low -amylase lines from heterozygotes (low -amylase phenotype but carriers of high -amylase) and has important implications for wheat breeders. High -amylase, termed late maturity -amylase, was not linked with the awned inhibitor gene, B2, located on the long arm of chromsome 6B.     

Postharvest UV-C irradiation on cut Freesia hybrida L. inflorescences suppresses petal specking caused by Botrytis cinerea

Postharvest petal specking caused by Botrytis cinerea is a major concern for freesia growers and sellers in Holland and the UK. Germicidal and inducible host defence effects of UV-C irradiation were evaluated. UV-C irradiation of freesia inflorescences after artificial inoculation with B. cinerea (i.e. the germicidal effect) was more effective in reducing petal specking, compared to UV-C treatment before artificial inoculation (i.e. the defence induction effect). Cut freesia inflorescences exposed to 1 kJ m^?2 UV-C after artificial inoculation with 10⁴ B. cinerea conidia mL^?1 displayed reduced disease severity scores, lesion numbers and lesion diameters by 74, 68 and 14%, respectively, compared to non-irradiated control inflorescences. In contrast, UV-C irradiation with 1 kJ m^?2 before artificial inoculation reduced lesion numbers and lesion diameters by 13 and 24%, compared to the non-irradiated controls. Higher UV-C doses of 2.5 or 5 kJ m^?2 reduced disease severity scores, lesion numbers and lesion diameters when applied after artificial inoculation, but enhanced disease when applied before artificial inoculation. Vase life of cut freesia inflorescences irradiated with 0.5, 1 or 2.5 kJ m^?2 UV-C was maintained equal to non-irradiated controls. However, 5 kJ m^?2 resulted in phytotoxicity evident as petal discoloration and reduced vase life compared to non-irradiated inflorescences.     

Nano-silver pulse treatments inhibit stem-end bacteria on cut gerbera cv. Ruikou flowers

Nanometer-sized silver (Ag⁺) particles (NS) are used in various applications as an anti-microbial. Effects of NS (2–5 nm diam.) pulse solution treatments on vase life of cut gerbera (Gerbera jamesonii) cv. Ruikou flowers were investigated. Compared with the control [pulsed with deionised water (DI) and subsequently held in DI] pulsing for 24 h with 5 mg/L NS solution followed by holding in DI maintained water uptake and extended vase life. From in vitro and microscopy assessments, NS pulse treatment inhibited bacteria growth in the vase solution and at cut stem ends during the first 2 d of the vase period.     

Effects of increasing ultraviolet B radiation on decomposition and soil organic matter dynamics: a synthesis and modelling study

The net effect of increasing ultraviolet B radiation levels on ecosystems is unknown. Most of the relevant ecological research has focused on the responses of living plants and algae to ultraviolet B exposure, with little attention directed toward other groups. However, research in such diverse areas of study as the degradation of textiles, pigments, synthetic polymers, paper, cellulose, wood, and museum artifacts show that ultraviolet light is a significant factor in the decay of many organic compounds. In aquatic ecosystems, the photochemical degradation of recalcitrant, dissolved organic compounds is increased by ultraviolet B exposure, and similar reactions could make important contributions to organic matter turnover in terrestrial ecosystems. This hypothesis is supported by observed patterns of decomposition of exposed surface litter in arid and semi-arid environments. Since plant lignins are both photochemically reactive and form a significant component of soil organic matter, ultraviolet B-induced lignin degradation could alter material cycling in terrestrial ecosystems. However, results of a model simulating the potential effects of ultraviolet B-induced lignin degradation suggest that higher rates of litter turnover may have only slight effects on soil organic matter dynamics.     

Synthesis of pyrazole derivatives and their evaluation as photosynthetic electron transport inhibitors

Two series of new pyrazoles, namely six pyrazolo[1,5-a][1,3,5]triazine-2,4-dione and four pyrazolo[1,5-c][1,3,5]thiadiazine-2-one derivatives, were synthesized as potential inhibitors of the photosynthetic electron transport chain at the photosystem II level. The compounds were confirmed by 1H NMR, elemental, and IR analyses. Their biological activity was evaluated in vivo upon both the growth of blue-green algae and the photosynthetic oxygen evolution by eukaryotic algae and in vitro as the ability to interfere with light-driven reduction of ferricyanide by isolated spinach chloroplasts. Some compounds exhibited remarkable inhibitory properties, comparable to those of the reference commercial herbicides lenacil, diuron, and hexazinone. Results suggest that the substitution of triazine with thiadiazine ring may act as amplifier for herbicidal activity.     

Synthetic pyrazole derivatives as growth inhibitors of some phytopathogenic fungi

The present study was carried out to investigate the antifungal activity of pyrazole/isoxazole-3-carboxamido-4-carboxylic acids, 4-oxo-5-substituted pyrazolo[3,4-d]pyrimidine-6-thiones, and N-alkyl/aryl-N'-(4-carbethoxy-3-pyrazolyl)thioureas against Pythium ultimum, Botrytis cinerea, and Magnaporthe grisea. The results on growth inhibition showed differences in the sensitivity of the three fungi to the tested substances, and in general P. ultimum was shown to be the most sensitive. On all phytopathogens the best results within the pyrazole/isoxazolecarboxamide series are given by the compounds with the carboxamide and carboxylic groups in positions 3 and 4; the presence of these groups seems to be critical for biological activity in this series of compounds. Among the pyrazolopyrimidines the derivative supplied with the benzylic group was the most active on the three fungi and in particular against P. ultimum. Several compounds belonging to the thiourea series are able to inhibit selectively M. grisea at 50 and 10 microg mL(-1), doses at which the reference commercial compound tricyclazole had low or no effect.     

In vivo digestibility and nitrogen balance in sheep diets with foliage of fodder trees in substitution for soybean meal

Apparent digestibility and nitrogen (N) balance were evaluated in sheep fed low-quality Cynodon nlemfuensis grass supplemented with different foliages of forage-potential trees. Four male hair sheep were housed in metabolic cages and fed in a Latin Square design with 30 % inclusion of foliage of Erythrina indica (Ei), Moringa oleifera (Mo), or Trichanthera gigantea (Tg) replacing soybean meal. Adaptation and faeces and urine collection periods were 14 and 7 days, respectively. Sheep received 70 g DM/kg/BW^0.75 of the diet in order to achieve total consumption of feed. Dry matter, organic matter, and neutral detergent fiber digestibilities were similar (P > 0.05) among the control, Mo, and Ei diets, while the Tg diet resulted in the lowest (P < 0.05) value. The Ei diet showed the highest (P < 0.05) total N intake among the three diets with 30 % of leaf meal, which was similar (P > 0.05) to the control diet. N excreted in faeces was highest (P < 0.05) in the Tg diet when compared to the other leaf meal diets, in which the Mo diet presented the lowest (P < 0.05) value, but was similar (P > 0.05) to that found in the control diet. The Mo and Ei diets had similar (P > 0.05) values for the percent of N absorbed by the animals, which was much higher (P < 0.05) than that of the Tg diet. The forage of M. oleifera and Ei can be used in diets at 30 % incorporation to substitute the use of soybean meal in small ruminant production.     

Switchgrass forage yield and biofuel quality with no-tillage interseeded winter legumes in the southern Great Plains

Information is limited on using winter legumes as a source of nitrogen (N) intercropped with switchgrass in the southern Great Plains of the United States. The objectives of this study were to evaluate N contribution of several winter legumes to switchgrass, and to determine the influence of winter legumes on biofuel quality and soil fertility status. Field experiments were conducted at two locations in Oklahoma in which six winter legumes and four rates of N fertilizer were studied over a 3-year period. Winter legumes did not increase switchgrass forage yield, cellulose, lignin, and hemicellulose concentrations at any location. Soil organic matter (OM), nitrate-N (NO₃-N), soil test phosphorus (P), soil test potassium (K), and soil pH remained unchanged. In contrast, applying inorganic N only increased switchgrass yield. This study demonstrated that southern Great Plains may not be conducive to utilizing legumes as the primary N source for switchgrass.