Control of Aeromonas hydrophila Infection in Spotted Snakehead, Channa punctatus, by Solanum nigrum L., a Medicinal Plant

The present study describes the potential of black nightshade, Solanum nigrum , to control Aeromonas hydrophila infection in spotted snakehead, Channa punctatus . Similar sizes of Ch.   punctatus were grouped into three categories as follows: control (injected with sterilized water), Ae.   hydrophila infected   +   untreated, and Ae.   hydrophila infected   +   treated with S.   nigrum leaf extract. Hematological parameters (white blood cell [WBC], red blood cell [RBC], hemoglobin [Hb], and packed cell volume [PCV]) were analyzed in these fishes once every 5   d from Days 5 to 30 postexposure. Preliminary antibacterial assay reported that leaf extracted with ethyl acetate had the maximum inhibition compared to other parts of the plant (i.e., berries and whole plant) or when extracted with other solvent extracts (chloroform and ethanol). Except for WBC count, all other parameters showed a declining trend from Day 5 onward and reaching to a minimum on Day 30 in Ae.   hydrophila -infected fish, whereas the WBC count increased. The infected fish treated with S.   nigrum leaf extract reported a significant reversion to normal RBC, WBC, Hb, and PCV levels and the skin ulceration recovered within a short period. The antiulcer potential of the medicinal plant as described in humans may be extended to the fish population.     

Influence of Solar Radiation and Vapour Pressure Deficit on Transpiration Efficiency of Rainfed Sorghum

Besides assimilation, plant water relations are important aspects of physiological basis of productivity of crops in water limited environment. The relationships of photosynthesis rate, transpiration rate, leaf water potential and stomatal conductance with photosynthetically active radiation (PAR) and vapour pressure deficit (VPD) during pre-flowering (panicle initiation to ear emergence) and grain filling (from anthesis to maturity) stages of a sorghum hybrid (cv. CSH-6 ) grown under rainfed conditions were studied. Photosynthesis rate declined when PAR was above 1300 μmol m⁻² s⁻¹. during both the growth stages. Higher transpiration rate during grain filling stage at higher PAR caused the transpiration efficiency to be lower than during pre-flowering stage when PAR was above 1200 μmol m⁻²s⁻¹.Leaf water potential and stomatal conductance decreased with increase in PAR. Leaf water potential was higher during pre-flowering than during grain filling stage but maximum photosynthesis rate was similar during both the growth stages. Changes in VPD did not qualitatively alter the relationships of the physiological variables with PAR.
Decreasing photosynthesis rate and LWP at high PAR suggest that photosynthesis rate was limited by low leaf water potential when PAR was optimal, and by low PAR even when leaf water potential was high in rainfed sorghum during rainy season.     

Correlation Studies and Path Coefficient Analysis in Sesame (Sesamum indicum L.)

Field investigations were carried out at the Agricultural College and Research Institute, Madurai, India during 1989—1990 to study the genotypic character association in sesame. The F4 and F5 generations of TSS6 X TMV3 and TMV3 X TSS6 were raised and eight genotypic characters were recorded: plant height; primary branches; secondary branches; capsule number per plant; seed number per capsule; 1000 seed—weight; oil content and seed yield per plant. Correlation studies showed that the magnitude and direction of correlation between eight pairs of traits varied with generations in both crosses involving two genotypes reciprocally. Single plant yield had a strong significant and positive relationship with capsule number in both generations of the two cross combinations indicating the close link between the two traits. The path coefficient analysis revealed that direct and indirect contributions by different traits primary branches, secondary branches, capsule number per plant, seed number per capsule and 1000—seed weight had to be considered as the most important traits in the determination of seed yield and selection of parents.     

Economics of Flexible Versus Conservative Stocking Strategies to Manage Climate Variability Risk

Recommended strategies for dealing with drought include maintaining a conservative stocking rate, maintaining grazing flexibility by having yearlings as one of multiple enterprises on the ranch, and leaving a significant amount of herbaceous production at the end of the grazing season. We perform an economic analysis of these grazing strategies using a bio-economic multiperiod linear programming model with variable annual forage production and beef prices. We evaluate the economics of conservative versus flexible grazing where stock numbers are adjusted to match forage conditions. The deterministic model estimates that a flexible grazing strategy could nearly double net returns relative to a conservative strategy, but realizing this substantial economic potential means higher production costs, and it depends on a quality climate forecast that is not currently available. Maintaining grazing flexibility was determined to be very important for managing variable forage conditions, and its importance increased with the level of variability. Without annual variation in forage production, over 80% of available forage would optimally be allocated to cow–calf production. As forage variability increased to levels observed on the arid rangelands of the western United States, a 50:50 forage allocation between cow–calf and yearling enterprises was found to be optimal, but optimal cow numbers decreased over time as dry conditions force herd reductions. As compared to a cow–calf ranch only, adding flexible yearling enterprises increased average annual net ranch returns by 14% with conservative stocking and by up to 66% with flexible grazing. Herd expansion beyond a conservative level should occur with yearlings because adjusting cow numbers is too expensive relative to the potential short-term gain, even if forage conditions are known with certainty.     

Silica-coated quantum dots and magnetic nanoparticles for bioimaging applications (Mini-Review)

Fluorescent quantum dots (e.g., CdSe-ZnS) and magnetic nanoparticles (e.g., Fe(2)O(3) or Fe(3)O(4)) are two important candidate systems that have been emerging as potential probes for bioimaging applications. This review focuses on the development of silica-coated inorganic probes (optical and magnetic) that are originated mainly from the author's laboratory for bioimaging applications. The recent developments in the synthesis of rare earth nanoparticles for multimodality imaging are also delineated.     

Hexanal and 1-MCP treatments for enhancing the shelf life and quality of sweet cherry (Prunus avium L.)

Sweet cherry has a short post-harvest shelf life and this greatly affects the consumer preference and export of fresh fruits. In this study, the effects of pre-harvest application of a hexanal formulation (enhanced freshness formulation, EFF) and post-harvest application of hexanal vapour and 1-MCP on quality parameters and shelf life of sweet cherry were investigated. Cherries subjected to pre-harvest spray with EFF had better color, brightness and firmness than unsprayed cherries even after 30 days of storage at 4 °C. These EFF-treated cherries also showed higher chroma values indicative of enhanced red color. Post-harvest application of either, hexanal vapour, 1-MCP, or a combination of both, enhanced the firmness of cherries. These treatments also resulted in higher levels of superoxide dismutase and ascorbate peroxidase activities. The levels of anthocyanins and phenolic components were either enhanced or maintained during the 30-day storage period. Our results suggest that a pre-harvest application of EFF combined with post-harvest treatment of hexanal and 1-MCP may enhance the quality and shelf life of sweet cherry.     

Diaryloxyacetate herbicides

The discovery and investigation of a novel family of herbicides containing a diaryl acetal are described. The stability of the acetal limited herbicidal efficacy and recognizing that fact led to the design of analogs with commercial levels of post-emergence activity on broadleaf weeds. These compounds inhibited acetolactate synthase and in vitro activity data were used to guide target design. However, no members of this family provided a commercially valuable combination of herbicidal efficacy and crop selectivity.     

Immunoprophylaxis against Theileria annulata with protein from plasma membrane of infected lymphoblasts

Cross-bred (Bos taurus male x Bos indicus female) calves were protected against the homologous sporozoite-induced challenge of Theileria annulata when immunised with protein from the plasma membrane of macroschizont-infected lymphoblasts of allogeneic origin. However, such protection was parasite-strain specific with the plasma membrane originating from lymphoblasts infected and transformed by the same isolate of T. annulata sporozoites. No protection ensued when the infected lymphoblasts and sporozoites were from immunologically different isolates of T. annulata. There was enhanced proliferation of cells and evidence for lymphokine, originating from antigen-sensitised lymphocytes, demonstrable as macrophage migration inhibition factor in peripheral blood lymphocytes of the calves immunised by plasma membrane protein and challenged by sporozoites of homologous origin.     

Seasonal abundance of western flower thrips and its natural enemies in different French bean agroecosystems in Kenya

The seasonal abundance of western flower thrips (WFT) [Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)] and its natural enemies on French beans in two agro-ecological zones (AEZs) (high and mid altitude) in Kenya, was studied in three growing cycles from January to December 2009. French beans were sampled every 2 weeks for WFT and natural enemies. Results show that colonization of French beans with WFT in both farm scales studied in the two AEZs started at 2- to 3-leaf stage. There was an increase in the population density of WFT from budding stage to podding/flowering stage, and it declined at crop senescence. The population densities of WFT on French beans were lower in the first compared with the second growing cycle and the highest in the third growing cycle. Two natural enemies of thrips, Orius spp. (Hemiptera: Anthocoridae) and Ceranisus menes (Walker) (Hymenoptera: Eulophidae), were recorded on French beans. The population density of C. menes was positively correlated with thatof WFT, while the population densities of Orius spp. and WFT were not correlated. The population density of WFT was not correlated with temperature and relative humidity, but was negatively correlated with rainfall. Our results suggest that the population density of WFT in the two AEZs differs along growing cycles and plant phenological stages. Management strategies targeted at WFT would need to start at early crop stages (3-leaf to budding stage), depending on growing cycle, to prevent further build-up of thrips population.