Search

This paper examines the association between stock exchange efficiency and the quality of reported earnings for publicly listed firms from 16 MENA countries between 2001 and 2010. The study shows that there is a positive association between stock exchange efficiency and the quality of reported earnings which is robust to potential endogeneity concerns. Meanwhile, the strength of this relationship is not affected by the other exogenous factors (i.e. investor protection, legal origin, economic and political shocks). These results are robust to the inclusion of industry or country fixed effects, exclusion of oil industry, and the use of alternative measures of earnings quality. The study contributes to the extant literature on expanding the definition of the stock exchange efficiency that goes beyond information efficiency. Further, as countries across MENA region are going through reforms, then a study of the influence of such reforms on stock exchange efficiency and earnings quality provides insights in the factors driving stock exchange efficiency in these countries. [ABSTRACT FROM AUTHOR]

Laccases are enzymes belonging to the group of oxidases. Laccases catalyze the oxidation of a variety of phenolic compounds, diamines and aromatic amines. Twenty-four fungal isolates were isolated from biodeteriorated ancient paper and parchment. These isolates were identified and found to belong to six genera: Alternaria , Aspergillus , Cladosporium , Penicillium , Rhizopus and Trichoderma , and were tested for producing laccase enzyme. Trichoderma harzianum have the ability of secreted laccase enzyme. The maximum production of laccase enzyme by T. harzianum was observed at 35 ○ C and pH 5 after 6 days. The highest activity of laccase achieved at 35 ○ C and pH 5 during the reaction. FTIR analysis revealed that the structure of extracted fungal pigments has aromatic ring and phenols group. Crude laccase was capable to decolorize different pigment structures. The enzyme showed great decolorization efficiency toward the extracted yellow pigment produced from Asp. terrus and Asp. ochareceous treated by 200 μl of partially purified enzyme. Laccase enzyme was used to decolorization pigment secreted from deteriorated pigmented fungi on paper and parchment during 30 days by using a pieces of paper and parchment inoculated by spore suspension. The results indicated that a high removal effect of fungal pigment on paper (71.21%) was recorded comparing to parchment samples (32.39%). [ABSTRACT FROM AUTHOR]

Soil samples were collected from different rhizosphere plants grown in SEKEM farm, Bilbis, El-Sharkyia governorate, Egypt. Four fluorescent pseudomonads isolates, out of seventy one, were selected according to their efficiency to produce IAA, cyanide, antagonistic effect and high ability to solubilize potassium and phosphorus. These isolates were identified using 16S rRNA gene sequencing technique to be different strains of Pseudomonas otitidis . Growth curve and growth kinetics were determined on king’s broth medium. Ps. otitidis SE8 gave the highest specific growth rate, multiplication rate and number of generation being 0.287 h −1 , 0.4147 h −1 and 4.98 h −1 , respectively. This strain also showed the lowest of doubling time. Ps. otitidis SE8 and OL2 had higher activity to solubilize phosphorus than other tested strains. Bacterial strain SE8 also gave a considerable amount of soluble potassium as compared with other strains being 80.7 ppm. The maximum IAA and gibberellic acid production was also recorded by Pseudomonas SE8 and OL2. A remarkable quantity of siderophores was detected in the case of Ps. otitidis SE8 being 28.20 mM DFOM. Application of these isolates as inoculants for tomato plants in green house was performed. The results showed that inoculation of tomato seedling with Pseudomonas strains led to suppress the soil-borne pathogen, increased of NPK uptake and supported tomato plant growth. [ABSTRACT FROM AUTHOR]

Densities of microbial count in the rhizosphere of eleven medicinal plants viz., Ocimum basilicum , Marrubium vulgare , Melissa officinals , Origanum syriacum , Quisqualis indica , Solidago virgaurea , Melilotus officinalis , Cymbopogon citratus , Matricaria chamomilla , Thymus vulgaris and Majorana hortensis were determined. The lowest populations were found in the rhizosphere of M. chamomilla and M. hortensis . A total of 112 bacterial cultures were successfully isolated in pure form from the rhizosphere of the tested medicinal plants. Cultural and morphological characteristics of these isolates showed that they belong to bacilli, azotobacter, fluorescent pseudomonads and actinomycetes. These isolates were screened, in vitro, according to their capacities to produce plant growth promoting substance i.e. IAA, phosphate, potassium solubilization, chitinase activities and hydrogen cyanide. Results indicated that 36 bacterial isolates showed IAA production, 25 HCN production, 57 chitinase activities, 39 phosphate and 105 potassium solubilizers. Eleven bacterial isolates were selected which showed highest plant growth promoting activities and further subjected to estimate siderophores and phenols produced in liquid culture along with antifungal activity against two phytopathogenic fungi. The most potent isolates were identified on the basis of 16S rRNA gene sequence as Bacillus thuringiensis C110 , Pseudomonas fluorescens Th98 and Pseudomonas poae Th75 . Their amounts of soluble phosphate in liquid culture were 2.2, 4.62 and 14.53 ppm in respective order. The indol-3-acetic acid (IAA), gibberellic acid (GA 3 ) and trans-zeatin riboside (t-zr) produced by the identified strains were determined by HPLC analysis. These strains proved to be effective PGPR inoculants, as they possess a number of traits useful for plant growth. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to develop a synthetic hydrogel to act as a corneal substitute capable of selectively supporting the adhesion and proliferation of limbal epithelial cells (LECs) while inhibiting growth of limbal fibroblasts. Deficiency of LECs causes conjunctival epithelial cells to move over the cornea, producing a thick scar pannus. Unilateral defects can be treated using LEC cultured from the unaffected eye, transplanting them to the affected cornea after scar tissue is removed. The underlying wound bed is often damaged, however, hence the need to develop a corneal inlay to aid in corneal re-epithelialization. Transparent epoxy-functional polymethacrylate networks were synthesized using a combination of glycerol monomethacrylate, ethylene glycol dimethacrylate, lauryl methacrylate and glycidyl methacrylate that produced two different bulk hydrogel compositions with different equilibrium water contents (EWCs): Base 1 and Base 2, EWC=55% and 35%, respectively. Two sets of amine-functional hydrogels were produced following reaction of the epoxide groups with excesses of either ammonia, 1,2-diamino ethane, 1,3-diamino propane, 1,4-diamino butane or 1,6-diamino hexane. Neither series of hydrogels supported the proliferation of limbal fibroblasts irrespective of amine functionalization but they both supported the adhesion and proliferation of limbal epithelial cells, particularly when functionalized with 1,4-diamino butane. With Base 1 hydrogels (less so with Base 2) a vigorous epithelial outgrowth was seen from small limbal explants and a confluent epithelial layer was achieved in vitro within 6days. The data support the development of hydrogels specific for epithelial formation. [Copyright &y& Elsevier]

Thirty isolates of Thiobacillus sp. were successfully isolated on Thiobacillus enrichment medium from different plants rhizosphere. Thiobacillus A1, Thiobacillus A2 gave the lowest pH and the highest total sulphate in liquid medium after one week. These two isolates were used as bioinoculants. The effect of inoculation with the two selected isolates and/or arbuscular mycorrhizal fungi (AMF) on onion and maize plants was studied in pot experiment under green house conditions. Mineral fertilizers were applied at the recommended dose of N, P, K and sulphur(S) besides rock phosphate (RP) as P fertilizer. Results showed that, inoculation gave significant increases in N, P, K and S concentrations in plants rhizosphere soil at the sampling periods of 60 and 90 days from planting. Highest values of nutrient concentrations were found in soils fertilised with NK + S + rock phosphate (RP) and inoculated with AMF + Thiobacillus A1. Total sulphur-oxidising bacterial counts, dehydrogenase activity (μg TPF/100 g dry soil Day −1 ) and CO 2 evolution (mg CO 2 /100 g soil) were determined in rhizosphere of the tested plants. Soil biology was affected by either mineral or biofertilizer treatments. Significant differences were found for samples collected after 60 days for onion and 90 days for maize fertilised with NK + S + RP and inoculated with AMF + Thiobacillus A1 which gave the highest significant differences over control. Mycorrhizal spores number and AMF infection percentages in plants roots greatly affected by AMF inoculation especially when combined with Thiobacillus A1 after 60 days from planting. Dry weight of onion bulbs and maize shoots as well as NPK contents significantly affected by AMF and Thiobacillus inoculations than the control plants. [ABSTRACT FROM AUTHOR]