Combined administration of Spondias mombin and Ficus exasperata leaf extracts stall Indomethacin-mediated gastric mucosal onslaught in rats.

Background: Despite the rapidly changing concept of gastric ulcer management from conventional vagotomy, H2 receptor antagonists and antacids to proton pump inhibitors, gastrointestinal toxicity remains an impediment to their application in clinical practice. Combined administration of two or more plant extracts with therapeutic efficacy may proffer solution to this menace. This study investigated the combined gastroprotective effects of Spondias mombin and Ficus exasperata leaf extracts against indomethacin-induced gastric ulcer in rats.Materials and Methods: Thirty rats were randomized into six groups of five animals each and ulceration was induced by a single oral administration of indomethacin (30 mg/kg body weight). Ulcerated rats were orally administered with Spondias mombin, Ficus exasperata at 200 mg/kg body weightand esomeprazole (a reference drug) at a dose of 20 mg/kg body  weight once daily for 21 days after ulcer induction. At the end of the experiment, gastric secretions and antioxidant parameters were evaluated.Results: We observed that the significantly increased (P < 0.05) ulcer index, gastric acidity, malondialdehyde level and pepsin activity were markedly reduced following co-administration of S. mombin and F. exasperata. The extracts also effectively attenuated the reduced activities of superoxide dismutase and catalase as well as pH, mucin content and reduced glutathione level in the ulcerated rats.Discussion and Conclusion: These findings are indicative of gastroprotective and antioxidative attributes of the two extracts which is also evident in the % protective index value obtained. The available evidences in this study suggest that the complementary effects of S. mombin and F. exasperata proved to be capable of ameliorating indomethacin-mediated gastric ulceration and the probable mechanisms are via antioxidative and proton pump inhibition.Key words: Esomeprazole; Gastroprotective; NSAIDS; Proton pump inhibitor; Ulceration

Effect of air pollution on the foliar morphology of some species in the family Euphorbiaceae in southwestern Nigeria

Morphological studies of the leaves of ten species in the family Euphorbiaceae collected from three different locations with different pollution levels in Southwestern Nigeria were carried out in order to establish the effect of air pollution on these species. The study was carried out in both dry and wet seasons. Climatic data and pollutants concentration levels of the study sites were determined. Leaf area of all the species was measured using an established nondestructive method while petiole length was determined using metric ruler. The result showed that most species showed significant reductions (p<0.05) in the leaf area and petiole length across the three locations and this reduction is from rural to sub-urban to urban areas. Among all the species that showed reductions in leaf area, Alchornea cordifolia showed the highest response while Euphorbia hyssopifolia, E. hirta and Croton lobatus do not show clear reductions. Similar significant reductions were recorded for petiole length with the highest impact recorded in Manihot esculenta while species like E. hyssopifolia, E. hirta, C. lobatus and Flueggea virosa were not significantly reduced. This study showed that plants generally respond to air pollution with reduction in foliar morphology and the response is species specific.Keywords: Pollution, leaf morphology, Euphorbiaceae, leaf area, petiole lengt

A time-domain control signal detection technique for OFDM

Transmission of system-critical control information plays a key role in efficient management of limited wireless network resources and successful reception of payload data information. This paper uses an orthogonal frequency division multiplexing (OFDM) architecture to investigate the detection performance of a time-domain approach used to detect deterministic control signalling information. It considers a type of control information chosen from a finite set of information, which is known at both transmitting and receiving wireless terminals. Unlike the maximum likelihood (ML) estimation method, which is often used, the time-domain detection technique requires no channel estimation and no pilots as it uses a form of time-domain correlation as the means of detection. Results show that when compared with the ML method, the time-domain approach improves detection performance even in the presence of synchronisation error caused by carrier frequency offset

Evaluation of Greenbug and Yellow Sugarcane Aphid Feeding Behavior on Resistant and Susceptible Switchgrass Cultivars

Switchgrass (Panicum virgatum L.) is an emerging biofuel crop that serves as host for aphids. To discern the effects of plant age and possible resistance mechanisms, the feeding behavior of greenbugs (Schizaphis graminum Rondani.) and the yellow sugarcane aphid (Sipha flava Forbes.) was monitored on three diverse switchgrasses by the electrical penetration graph (EPG) technique. Callose deposition and genes associated with callose metabolism were also analyzed to discern their association with plant resistance. There was a strong host effect on greenbugs feeding on lowland cultivar Kanlow at the V3 stage of development, as compared to the greenbug-susceptible upland cultivar Summer and plants derived from Kanlow (♂) × Summer (♀) (K×S) crosses. These data confirmed that Kanlow at the V3 stage had antibiosis to greenbugs, which was absent in the Summer and K×S plants. In contrast, similar effects were not observed for yellow sugarcane aphids, excluding significant differences in the time to first probe on Kanlow plants at the V1 stage and reduction in time spent on pathway processes on Kanlow plants at the V3 stage. These data demonstrated that Kanlow plants may have multiple sources of resistance to the two aphids, and possibly some were phloem based. Microscopy of leaf sections stained with aniline blue for callose was suggestive of increased callose deposition in the sieve elements in Kanlow plants relative to Summer and K×S plants. RT-qPCR analysis of several genes associated with callose metabolism in infested plants was equivocal. Overall, these studies suggest the presence of multiple defense mechanisms against aphids in Kanlow plants, relative to Summer and K×S plants

Overexpression of the aphid-induced serine protease inhibitor <i>CI2c </i>gene in barley affects the generalist green peach aphid, not the specialist bird cherry-oat aphid

<div><p>Aphids are serious pests in crop plants. In an effort to identify plant genes controlling resistance against aphids, we have here studied a protease inhibitor, CI2c in barley (<i>Hordeum vulgare</i> L.). The <i>CI2c</i> gene was earlier shown to be upregulated by herbivory of the bird cherry-oat aphid <i>(Rhopalosiphum padi</i> L.<i>)</i> in barley genotypes with moderate resistance against this aphid, but not in susceptible lines. We hypothesized that CI2c contributes to the resistance. To test this idea, cDNA encoding <i>CI2c</i> was overexpressed in barley and bioassays were carried out with <i>R</i>. <i>padi</i>. For comparison, tests were carried out with the green peach aphid (<i>Myzus persicae</i> Sulzer), for which barley is a poor host. The performance of <i>R</i>. <i>padi</i> was not different on the <i>CI2c</i>-overexpressing lines in comparison to controls in test monitoring behavior and fecundity. <i>M</i>. <i>persicae</i> preference was affected as shown in the choice test, this species moved away from control plants, but remained on the <i>CI2c</i>-overexpressing lines. <i>R</i>. <i>padi</i>-induced responses related to defense were repressed in the overexpressing lines as compared to in control plants or the moderately resistant genotypes. A putative susceptibility gene, coding for a β-1,3-glucanase was more strongly induced by aphids in one of the <i>CI2c</i>-overexpressing lines. The results indicate that the CI2c inhibitor in overexpressing lines affects aphid-induced responses by suppressing defense. This is of little consequence to the specialist <i>R</i>.<i>padi</i>, but causes lower non-host resistance towards the generalist <i>M</i>. <i>persicae</i> in barley.</p></div

Aphid-host plant interactions: Does aphid honeydew exactly reflect the host plant amino acid composition?

peer reviewedPlants provide aphids with unbalanced and low concentrations of amino acids. Likely, intracellular symbionts improve the aphid nutrition by participating to the synthesis of essential amino acids. To compare the aphid amino acid uptakes from the host plant and the aphids amino acid excretion into the honeydew, host plant exudates (phloem + xylem) from infested and uninfested Vicia faba L. plants were compared to the honeydew produced by two aphid species (Acyrthosiphon pisum Harris and Megoura viciae Buckton) feeding on V. faba. Our results show that an aphid infestation modifies the amino acid composition of the infested broad bean plant since the global concentration of amino acids significantly increased into the host plant in response to aphid infestations. Specifically, the concentrations of two amino acids glutamine and asparagine were strongly enhanced. The amino acid profiles from honeydews were similar for the two aphid species, but the concentrations found into the honeydews were generally lower than those measured in the exudates of infested plants (aphids uptakes). This work also highlights that aphids take large amounts of amino acids into the host plant, especially glutamine and asparagine which are converted into glutamic and aspartic acids but also into other essential amino acids. The amino acid profiles differed between the host plant exudates and the aphid excretion product. Finally, this study highlights that the pea aphid - a “specialist” for the V. faba host plant - induced more important modifications into the host plant amino acid composition than the “generalist” aphid M. viciae.Solaphi