Relationship between Hidrogenionic Potential (pH) of Protein-based Baits and Attraction of the Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann)

Hidrogenionic potential (pH) of the baits plays a fundamental role in attracting fruit flies. So, the purposes of this study were to study the effect of pH-level on the ability of protein-based baits to attract Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) under field conditions. Three concentrations of Buminal (2.5, 5 and 10%) in addition to three concentrations of ammonium acetate, ammonium carbonate, di-ammonium phosphate and acetic acid (1, 2 and 3%) added to Buminal 5% were tested by using the modified Nadel traps in navel orange and mandarin orchards. The obtained data showed that the highest effective treatment in attracting C. capitata adults in navel orange and mandarin orchards was that of Buminal + 3% of ammonium acetate, where, pH-levels ranged between 6.32 and 6.89. Buminal + acetic acid when used at pH-levels ranged between 3.73 and 4.43 were less attractive to C. capitata. All of the tested treatments obviously attracted females more than males. Statistically, C. capitata adults specifically were females affected by pH-level more than concentration percentage. C. capitata preferred baits which had pH-levels ranged between 5.5 and 8.5 and the highest attractive treatments were occurred between 6.32 and 8.29

Physiological responses to excess boron in wheat cultivars

This study investigates the response of two wheat cultivars to boron toxicity stress. Plants were cultivated in sand culture and boron was applied to the culture for 10-day. Symptoms, tiller number, boron concentration, soluble sugars, proteins and other free amino acids than proline were studied. The differences between the cultivars were apparent from higher boron and the chlorosis in tolerant cultivar was about 7% compared to the sensitive one 70%. Tiller number gradual decreased in tolerant-cultivar, while in sensitive one a dramatic reduction was exhibited by increasing boron level in culture media. In most boron levels, although the accumulation of soluble carbohydrates was significantly stimulated in shoot of B-sensitive cultivar (Gemmeza 9; S), there were no appreciable differences in the production of carbohydrates in shoot of B-tolerant cultivar (Sakha 93; T). However, the soluble proteins production did not affect by most boron levels in both cultivars. The presence of boron at various concentrations induced a production of free amino acids in shoots of each of the two test cultivars. Tiller number (yield index) decreased in the two test cultivars and was in range 50-59 and 84-92% less than control plants for tolerant and sensitive cultivar, respectively. DOI: http://dx.doi.org/10.5281/zenodo.20037

Corrosion Control of Mg-Zn Implant Alloys in Simulated Body Fluid

Magnesium alloys have recently attracted the attention as a new biodegradable material.  In this study, Mg-Zn alloys (1-4wt.% Zn) were fabricated with high purity raw materials using a clean melting process (fluxless method) and a protective atmosphere of CO2 + 0.4 SF6. The as-cast microstructures of the investigated alloys were characterized by optical and scanning electron microscopes, EDS and XRD. Corrosion properties of the prepared alloys were examined in simulated body fluid (SBF) by electrochemical techniques and immersion test (hydrogen evolution method).  Surface modification of the prepared alloys was performed using micro arc oxidation (MAO) treatment and hydroxiapatite (HA) coating. The results of the as-cast microstructure showed that Zn up to 2 wt% was completely dissolved in a-Mg matrix. On increasing Zn content (> 2wt%) the grain size decreased and a second MgZn2 phase was observed. Corrosion testing results revealed that Mg-1,2,3 wt% Zn have almost the same corrosion rates (0.025 mm/y) whereas Mg-4Zn has the highest degradation rate. Hydroxiapatite (HA) coating on micro-arc oxidation (MAO) treated magnesium alloys formed a dense and compact layer on the surface of magnesium alloys which had greatly improved surface properties and enhanced corrosion resistance of the prepared alloys. Keywords: Mg alloys, implants, biodegradable, corrosion, surface modificatio

Suppressive efficiency of Kojic acid from Aspergillus tamarii MM11 against HepG-2 cell line derived from human liver cancer

Purpose: To evaluate the antioxidant and cytotoxic properties of Kojic acid (KOJIC ACID) from Aspergillus tamarii MM11 against HepG-2 cell line derived from human liver cancer.Methods: The crude extract of A. tamarii MM11 was dissolved in a mixture of CH2Cl2/MeOH (85:15) and separation was done using silica gel chromatography using gradient size exclusion chromatograph. The non-polar oily fractions were subjected to gas chromatography-mass  spectrometric (GC-MS) analysis. Kojic acid structure was identified by x-beam crystallography and spectroscopic methods. Total antioxidant properties of KOJIC ACID were evaluated by using 1,1-diphenyl-2- picrylhydrazyl (DPPH) against ascorbic acid as a reference. The cytotoxic activity of KOJIC ACID from A. tamarii MM11 was investigated on the human cell line of liver cancer (HepG-2) using a sulforhodamine B (SRB) assay based on a cell density determination by the measurement of cellular protein content.Result: Highly bioactive Kojic acid was isolated as the main product. A. tamarii MM11 Kojic acid showed good antioxidant activity with half-maximal inhibitory concentration of IC50 at concentrations of 10.34 compared to 6.79 μg/mL for ascorbic acid. Kojic acid also showed good cytotoxic activity against HepG-2 cell line of human liver cancer with IC50 at 6.20 compared to 3.25 μg/mL of reference drug doxorubicin.Conclusion: Kojic acid produced naturally from A. tamarii MM11 shows good antioxidant and cytotoxic activity against HepG-2 cell line derived from  human liver cancer. These findings suggest that Kojic acid can be therapeutically used as an antitumor drug after further in vivo studies. Keywords: Aspergillus tamarii, Secondary metabolites, Kojic acid, Anticancer, Liver cance

Daily flight activity rhythms of the peach and mediterranean fruit flies using sexual and olfactory attractants

The periodicity of insect activity is affected by endogenous and exogenous factors, and these factor thresholds often limit its activity. The flight activity within 24 h circadian rhythm is often influenced by light, whereas the abundance is affected by temperature. This study aimed to hourly follow the flight activity of the peach (PFF) and Mediterranean (MFF) fruit flies, at guava orchard, using sexual and olfactory attractants. The flight of PFF males usually started before that of females, whereas that of MFF males was in the same time as females. As temperature rose above 30 °C, the flight activity of males affected, but that of females not. Thus, flight activities of males were negatively, and females were positively, correlated with temperature. On the contrary, males were positively, and females were negatively, correlated with relative humidity. The sexual attractant attracted more PFF males than MFF, but the olfactory attractants attracted more PFF females than MFF. The highest male captures were between 7:00 am and 10:00 am, and females between 11:00 am and 5:00 pm, suggesting males fly actively during the morning to locate their mates, whereas females fly actively during the afternoon to locate their food and/or distribute their eggs. This also suggests that PFF and MFF are diurnal species. For management of both species, the spray treatments therefore should be taken during the time interval 7:00 am and 10:00 am for males (to disrupt mating) and 11:00 am and 5:00 pm for females (to disrupt feeding and oviposition)

On a System of Difference Equations of an Economic Model

We study some qualitative properties of the solutions of a system of difference equations, which describes an economic model. The study of the local stability of the equilibrium points is carried out. We give some important results of the invariant and the boundedness of the solutions to the considered system. The global convergence of the solutions is presented and investigated