Isolation and characterization of a Serratia marcescens with insecticidal activity from Polyphylla olivieri (Col.: Scarabaeidae)

Members of the genus Serratia are known for their abilities to infect insects. In this study, a red‐pigmented S. marcescens was isolated and characterized from the infected larvae of Polyphylla olivieri using bacterial cultivation, phylogenetic analysis as well as bioassays against larvae of the two insect pests, Plodia interpunctella and Ephestia kuehniella. Comparative 16S rRNA and groEL gene sequence BLAST analyses strongly suggested that the isolated strain should be placed in the genus Serratia, sharing high sequence similarities with several strain of S. marcescens associated with insects. Phylogenetic analysis placed the isolated bacterium with other S. marcescens bacteria in a clade with high bootstrapping values. To assess pathogenicity of the S. marcescens isolate, the bacterial cells were either injected into the haemolymph of the fifth‐instar larvae or added to the diets of insects. Survival curves of the control insects and those challenged with six different concentrations of S. marcescens showed that the S. marcescens isolate significantly reduced survival rates of the larvae. The LC₅₀s of the bacterium on P. interpunctella and E. kuehniella were 1992.26 and 1.09 × 10⁴ (CFU/μl) for injection bioassays at 6 h post‐injection, and 4.48 × 10⁴ and 1.96 × 10⁵ (CFU/10 μl) for feeding bioassays at 24 h post‐feeding, respectively. Injection of the bacterial culture supernatant into the larvae led to continuous bleeding from the site of injection, while injection of heat‐treated culture supernatant of the bacterium did not cause continuous bleeding. Together, our results showed the possibility of using this S. marcescens isolate in microbial control of the insect pests after addressing the safety concerns. Moreover, it might be considered as a source of useful bioactive molecules and genes with application in insect control and biotechnology via developing insect‐resistant plants.     

Quantification of homozygosity in consanguineous individuals with autosomal recessive disease

Individuals born of consanguineous union have segments of their genomes that are homozygous as a result of inheriting identical ancestral genomic segments through both parents. One consequence of this is an increased incidence of recessive disease within these sibships. Theoretical calculations predict that 6% (1/16) of the genome of a child of first cousins will be homozygous and that the average homozygous segment will be 20 cM in size. We assessed whether these predictions held true in populations that have preferred consanguineous marriage for many generations. We found that in individuals with a recessive disease whose parents were first cousins, on average, 11% of their genomes were homozygous (n = 38; range 5%-20%), with each individual bearing 20 homozygous segments exceeding 3 cM (n = 38; range of number of homozygous segments 7-32), and that the size of the homozygous segment associated with recessive disease was 26 cM (n = 100; range 5-70 cM). These data imply that prolonged parental inbreeding has led to a background level of homozygosity increased approximately 5% over and above that predicted by simple models of consanguinity. This has important clinical and research implications.     

Effect of glenoid prosthesis design on glenoid bone remodeling: Adaptive finite element based simulation

Glenoid prosthesis loosening is the most common cause for revision total shoulder arthroplasty. Improved glenoid prosthesis design requires looking beyond initial post-implantation static stress analyses. Adaptive bone remodeling simulations based on Wolff’s law are needed for predicting long-term glenoid prosthesis results. This study demonstrates the capability of predicting glenoid bone remodeling produced by changing prosthesis design features. Twelve glenoid prostheses were designed to fit each of six donor human glenoids, using combinations of three peg types and four backing-peg material combinations (polyethylene and or metal). The twelve FE prosthesis models were individually combined, simulating surgical implantation, with the glenoid models. Remodeling simulations, using a validated adaptive bone remodeling simulation, commenced with homogeneous glenoid bone density. To produce bone remodeling, center, posterior-offset, and anterior-offset physiologic loads were consecutively applied to the bone–prosthesis FE models for 300 iterations. Upon completion, region-specific mean predicted bone apparent densities were compared between bone–prosthesis and intact glenoid FE models. Metal fixations significantly increased proximal-center bone density. Polyethylene fixations resulted in bone density approximately equal to intact. Two angled polyethylene peg designs with longer-anterior and shorter-posterior pegs, reflecting natural glenoid shape, best maintained mid and distal glenoid bone density. While these initial results were not validated, they demonstrate the capability and potential of adaptive glenoid bone remodeling simulation. We expect FE glenoid bone remodeling simulations to become powerful and robust tools in the design and evaluation of glenoid prostheses.     

By-products formed during direct conversion of sugar beets to ethanol byZymomonas mobilis in conventional submerged and solid-state fermentations

Summary The nature and amounts of by-products formed during conversion of sugar beets to ethanol byZ. mobilis in Conventional Submerged Fermentation (CSF) and Solid-State Fermentation (SSF) were investigated. It was found that the bacterium produced fewer by-products in SSF than CSF, and that by-products profile was different. The influence of fermentation temperature on synthesis of by-products in SSF was also studied. High fermentation temperature favoured sorbitol synthesis and low fermentation temperature the synthesis of levan. The best results were obtained at 35°C. An ethanol yield of up to 95% of the theoretical value with final ethanol concentration of 142 g/L were obtained.     

Metabolic response to [13C]glucose and [13C]fructose ingestion during exercise

Seven healthy male volunteers exercised on a cycle ergometer at 50 +/- 5% VO2max for 180 min, on three occasions during which they ingested either water only (W), [13C]glucose (G), or [13C]fructose (F) (140 +/- 12 g, diluted at 7% in water, and evenly distributed over the exercise period). Blood glucose concentration (in mM) significantly decreased during exercise with W (5.1 +/- 0.4 to 4.2 +/- 0.1) but remained stable with G (5.0 +/- 0.4 to 5.3 +/- 0.6) or F ingestion (5.4 +/- 0.5 to 5.1 +/- 0.4). Decreases in plasma insulin concentration (microU/ml) were greater (P less than 0.05) with W (11 +/- 3 to 3 +/- 1) and F (12 +/- 4 to 5 +/- 1) than with G ingestion (11 +/- 2 to 9 +/- 5), and fat utilization was greater with F (103 +/- 11 g) than with G ingestion (82 +/- 9 g) and lower than with W ingestion (132 +/- 14 g). However F was less readily available for combustion than G; over the 3-h period 75% (106 +/- 11 g) of ingested G was oxidized, compared with 56% (79 +/- 8 g) of ingested fructose. As a consequence, carbohydrate store utilizations were similar in the two conditions (G, 174 +/- 20 g; F, 173 +/- 17 g; vs. W, 193 +/- 22 g). These observations suggest that, during prolonged moderate exercise, F ingestion maintains blood glucose as well as G ingestion, and increases fat utilization when compared to G ingestion. However, due to a slower rate of utilization of F, carbohydrate store sparing is similar with G and F ingestions.     

Exogenous Application of Selenium Mitigates Cadmium Toxicity in <Emphasis Type="Italic">Brassica juncea</Emphasis> L. (Czern &amp; Cross) by Up-Regulating Antioxidative System and Secondary Metabolites

The main aim of the present study was to examine the role of selenium (Se) in ameliorating the toxic effect of cadmium (Cd) in mustard (Brassica juncea) plants. The plants exposed to elevated levels of Cd exhibited reduced biomass, pigment content, and relative water content (RWC). However, supplementation of Se restores the negative effect of Cd and increases biomass, pigment content, and RWC. Osmolyte (proline and glycine betaine) and sugar content were increased under Cd stress and further increase was observed with addition of Se. Cd decreased protein content and supplementation of Se increases it to appreciable levels. Cd also increased production of H₂O₂ and lipid peroxidation, electrolyte leakage, and the activities of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, and glutathione reductase. Supplementation of Se decreased accumulation of H₂O₂ and lipid peroxidation, increased the activities of antioxidant enzymes to greater levels, and regulates Cd accumulation in roots and shoots. Ascorbic acid (AsA) and flavonoids decreased with elevated concentrations of Cd; however, tocopherol and total phenols were increased with the same concentrations of Cd. Se application maintains AsA and flavonoid content, and further increase in tocopherol and total phenols were observed with Se in the present study. Overall the results confirm that exogenous application of Se mitigates the negative effects of Cd stress in mustard plants through the regulation of osmoprotectants, antioxidant enzymes, and secondary metabolites.     

Anti-genotoxic effect of Ocimum sanctum L. extract against cyproterone acetate induced genotoxic damage in cultured mammalian cells

The anti-genotoxic effect of Ocimum sanctum L. extract was studied against the genotoxic effect induced by a synthetic progestin cyproterone acetate, on human lymphocytes using chromosomal aberrations, mitotic index, sister chromatid exchanges and replication index as a parameters. About 30 microM of cyproterone acetate was treated with O. sanctum L. infusion, at dosages of 1.075 x 10(-4), 2.125 x 10(-4) and 3.15 x 10(-4) g/ml of culture medium. A clear dose-dependent decrease in the genotoxic damage of cyproterone acetate was observed, suggesting a possible modulating role of the plant infusion. The results of the present study suggest that the plant infusion per se does not have genotoxic potential, but can modulate the genotoxicity of cyproterone acetate on human lymphocytes in vitro.     

Restriction of transpiration rate under high vapour pressure deficit and non‐limiting water conditions is important for terminal drought tolerance in cowpea

Drought stress is a major constraint on cowpea productivity, since the crop is grown under warm conditions on sandy soils having low water‐holding capacity. For enhanced performance of crops facing terminal drought stress, like cowpea, water‐saving strategies are crucial. In this work, the growth and transpiration rate (TR) of 40 cowpea genotypes with contrasting response to terminal drought were measured under well‐watered conditions across different vapour pressure deficits (VPD) to investigate whether tolerant and sensitive genotypes differ in their control of leaf water loss. A method is presented to indirectly assess TR through canopy temperature (CT) and the index of canopy conductance (Ig). Overall, plants developed larger leaf area under low than under high VPD, and there was a consistent trend of lower plant biomass in tolerant genotypes. Substantial differences were recorded among genotypes in TR response to VPD, with tolerant genotypes having significantly lower TR than sensitive ones, especially at times with the highest VPD. Genotypes differed in TR response to increasing VPD, with some tolerant genotypes exhibiting a clear VPD breakpoint at about 2.25 kPa, above which there was very little increase in TR. In contrast, sensitive genotypes presented a linear increase in TR as VPD increased, and the same pattern was found in some tolerant lines, but with a smaller slope. CT, estimated with thermal imagery, correlated well with TR and Ig and could therefore be used as proxy for TR. These results indicate that control of water loss discriminated between tolerant and sensitive genotypes and may, therefore, be a reliable indicator of terminal drought stress tolerance. The water‐saving characteristics of some genotypes are hypothesised to leave more soil water for pod filling, which is crucial for terminal drought adaptation.