Thermal,swelling and stability kinetics of chitosan based semi-interpenetrating network hydrogels

The present study is focused on studying the swelling kinetics, thermal and aqueous stabilities, and determination of various forms of water in the chitosan (CS) and polyacrylonitrile (PAN) blend and semi-interpenetrating polymer network (sIPN). CS/PAN blend hydrogel films were prepared by solution casting technique. The blend film with optimum swelling properties was selected for the synthesis of sIPN. CS in the blend was crosslinked with the vapors of Glutaraldehyde (GTA) to prepare sIPN. The fabricated CS/PAN blend and sIPN hydrogels films were characterized with Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and field emission scanning electron microscope (FESEM). The kinetics of swelling, bound and unbound waters and aqueous stability were determined experimentally. FESEM showed good miscibility between CS and PAN, FTIR showed no chemical interaction between CS and PAN; however, it did show a doublet for the sIPN, TGA showed improved thermal stability and swelling kinetic followed second order kinetics. The degree of swelling of the sIPN hydrogels samples at room temperature varied from ~2200 % (with a fair degree of stability (~30 %)) to ~1000 % (with high degree of aqueous stability (43 %)) with increase in the crosslinking time. The calculated unbound water (W_UB) max., for the blend was 52.3 % whereas for the bound (W_B) the max., was 41.9 %. However, for sIPN hydrogel films, the W_UB water decreased (max. 21.0 %) where as the W_B increased (max. 52.0 %). The decrease in W_UB and increase in the W_B is attributed to the formation of a compact structure and increase in the contact area between the water and polymers in sIPN hydrogels due to the induction of new water contacting point in these hydrogel films, respectively.     

Zur Wirkung von Milchsäure auf den Varroa-Befall der Biene

40% lactic acid was sprayed 3 times into each of two bee colonies. The rate of infestation was determined, before beginning the experiment and after each of the applications. The treatments showed a mean percentage reduction in the brood infestation byVarroa of 76,7% in the first colony and 85,2% in the second. These data indicate that it is possible to control the Varroasis by means of lactic acid successfully and without side effects.     

Evaluation of the Breeding Soundness of Male Camels (Camelus dromedarius) via Clinical Examination,Semen Analysis,Ultrasonography and Testicular Biopsy: A Summary of 80 Clinical Cases

Male camel infertility is a heterogeneous disorder. A variety of factors may adversely affect sperm production and function and impair fertility. This study was designed to evaluate the sensitivity and specificity of ultrasonography and testicular biopsy in the evaluation of the breeding soundness of male dromedaries compared with results obtained by clinical examination and semen analysis. Eighty‐four male dromedary camels (5–15 years old) were used in this study during the rutting season (November–May). Four sexually mature male camels were used as controls. These animals were apparently healthy and had histories of normal fertility. Eighty infertile male camels were subjected to an algorithmic approach based on information collected during careful examinations of the camels' breeding histories, clinical examinations, testicular evaluations, testicular ultrasonographies, the results of the semen analyses and testicular biopsies to diagnose the camels' infertilities. The differences in the semen parameters between the control and infertile male camels were highly significant (p < 0.01). Regarding the diagnoses of male camel infertility, the results of testicular ultrasonographies and biopsies were compared with those from the semen analyses, and the accuracies of these tests were 92.5% and 90%, respectively. Additionally, the results of the testicular ultrasonographies were matched with those of the testicular biopsies of the infertile animals, and this comparison resulted in 85% accuracy. Testicular biopsy is a promising method that, along with a carefully performed history, clinical examination, an appropriate testicular ultrasonography procedure and semen analysis, can afford veterinarians the opportunity for more precise diagnosis and treatment of many dromedary infertility disorders.     

Effect of varying density and water level on the spawning response of African catfish Clarias gariepinus: Implications for seed production

The development of a reliable methodology for spawning of African catfish, Clarias gariepinus without the use of hormone injections would greatly improve the prospects of aquaculture in Africa. Earlier work has shown that it is possible to produce C. gariepinus fingerlings by subjecting the broodfish to a physical stress of reduced water depth and/or increased temperature. The hypothesis that C. gariepinus could be induced to spawn through a combined physical stress of lowered water level and increased stocking density was tested in concrete tanks. Three water levels (25, 50 and 75 cm) and three stocking densities (2, 4 and 6 pairs of broodfish at a 1:1 sex ratio in each hapa) were tested. Water depth in the tanks and brood fish density in the hapas affected spawning success. The percentage of spawning females was significantly higher when broodfish were stocked at 2 and 4 pairs in each hapa at water levels of 25 cm or 50 cm. There was no significant difference in spawning response between the 25 and 50 cm depths while a significant difference was seen between the 75 cm and both 25 and 50 cm depths. The results indicate optimum levels and densities for enhancing spawning success in C. gariepinus.     

Egg production,fertility, hatchability and immune responses of some chicken strains under high ambient temperatures

This experiment was designed to investigate and compare the egg production, fertility, hatchability and immune responses of some local developed Egyptian chicken strains under high ambient temperatures. A total of 108 (26 weeks old) laying hens of Matrouh, Silver Montazah, Mandarah and Inshas (9 hens × 3 replicates × 4 strains) were used to evaluate the impact of thermal stress (24-34ºC) during summer season (June, July and August) on egg production, fertility, hatchability and immune responses. The obtained results revealed that final body weight (FBW/g) and body weight change (BWC/g) among different chicken strains were not affected. The daily feed consumption (FC/g) and feed conversion ratio (FCR) for Silver Montazah and Inshas strains were significantly (p ≤ .05) higher than those of Matrouh and Mandarah strains. The mean egg production (EP/%) and egg mass (EM) for Silver Montazah and Inshas strains were significantly (p ≤ .05) higher than those of Matrouh and Mandarah strains. The highest percentages of hatchability of total eggs (HTE) and fertile eggs (HFE) were recorded in Inshas chickens, while the lowest value was recorded in Mandarah chickens. Also, the highest embryonic mortalities (p ≤ .05) and lowest chick weight at hatch (CWH/g) were recorded in Mandarah chickens compared with the other strains. The highest values for antibody titres against phytohemagglutinin-P (PHA-P) were recorded in Mandarah chickens, while the least values were recorded in Inshas chickens.     

Use of cyproterone acetate to lower circulating corticosterone and its effects on lymphocytes in domestic fowl

Chickens were given daily injections of cyproterone acetate (CA) and the effects on plasma corticosterone, bodyweight, weights of the adrenals and lymphoid organs, numbers of circulating peripheral blood lymphocytes and their proliferation in the presence of lectins, concanavalin A (Con A) and phytohaemagglutinin (PHA), were investigated. Five daily doses of 10 or 30 mg CA kg-1 bodyweight each week over a three-week period caused a decrease in weight gain and a reduction in the relative weights of the bursa and thymus but not the spleen. There was a small decrease in the adrenals after treatment with 10 mg CA kg-1. When daily injections of CA were given over a seven-day period doses of 6 and 10 mg CA kg-1 bodyweight caused a significant (P less than 0.05) decrease in plasma corticosterone concentration after four days. However, after eight daily injections of CA a single injection of corticotrophin (10 iu ACTH kg-1) increased circulating corticosterone indicating CA had not completely blocked adrenal synthesis. CA had no effect on numbers of circulating peripheral blood lymphocytes or their ability to proliferate in the presence of Con A or PHA. The results indicate that CA is effective in lowering circulating corticosterone in the fowl but this did not affect the numbers or responsiveness of peripheral blood lymphocytes.     

Molecular cloning and expression of a larval immunogenic protein from the cattle tick Boophilus annulatus

A full-length cDNA of an immunogenic protein was cloned from a cDNA library of the local Egyptian cattle tick Boophilus annulatus. Antibodies raised against B. annulatus larval proteins were used to screen a cDNA expression library. A 936bp cloned fragment was sequenced and showed an open reading frame of 516bp encoding a protein of 171 amino acids. Comparison of the deduced amino acid sequence with protein data bank revealed that the sequence is related to a sequence isolated from the hard tick Haemaphysalis qinghaiensis (Hq05). Southern blot analysis of B. annulatus genomic DNA showed that the cloned cDNA hybridized to double bands per restriction digest, suggesting that the cloned cDNA is a double copy gene. Amino acid analysis of the cloned gene revealed the presence of two casein kinase II phosphorylation sites in the N-terminal domain suggesting that this molecule may be involved in the signal transduction or gene expression pathways. RT-PCR and northern blotting revealed the presence of two isoforms of the Ba05 gene in salivary glands and in the 3-day-old eggs. The cloned gene without the signal peptide, was expressed in Escherichia coli under T7 promotor of pET-30b vector, and purified under denaturation conditions. The purified protein appeared as a single band on 12% SDS-PAGE with a molecular weight around 22.8kDa including the histidine tag of the vector. Antibodies raised against the purified molecule were used to detect the B. annulatus homologue to the Hq05 gene in whole tick, larvae and gut protein extracts. Immunoblotting revealed the presence of this molecule Ba05 only in whole tick and larval protein extracts and not in the gut protein extract. Using the same antibodies, homologues to the Ba05 gene were detected in other tick species as Hyalomma dromedarii and Rhipicephalus sp. but not in Ornithodoros moubata.     

Bacillus subtilis as an alternative biologically based strategy for controlling Fusarium wilt disease in tomato: A histological study

The employment of formulateBacillus subtilis as a biocontrol agent successfully controlledFusarium oxysporum f.sp.lycopersici within tomato seedlings (in vivo). B. subtilis was able to proted cortex and vascular tissues of tomato against progression of the wilt pathogen. No changes were observed in tomato tissues due to application ofB. subtilis except for hypertrophy and elongation of cortex tissues, which indicates the production of plant growth hormones byB. subtilis.     

Lipid metabolism in tomato and bean as a sensitive monitor for biocontrol of wilt diseases

The lipids metabolism of tomato and bean plants during biological control of wilt pathogens (Fusarium oxysporum f.sp.lycopersici andF. oxysporum f.sp.phaseoli, respectively) byBacillus subtilis was investigated. The interaction of wilt pathogens with both tomato and bean caused an imbalance and drastic reduction in total lipids, triacylglycerol, sterol and all phospholipd fractions except phosphatidic acid. The application of a formulated biocontrol agent,B. subtilis, eliminated the detrimental effect of both wilt pathogens and consequently prevented catabolism of lipid fractions in both tomato and bean. Moreover, the changes in the lipid fractions as a sensitive monitor for biocontrol of wilt diseases suggest a positive correlation between the application ofB. subtilis and improvement in the host metabolism towards anabolism. http://www.phytoparasitica.org posting Sept. 20, 2006.     

Increasing Farm Productivity and Soil Fertility on Sustainable Basis Through “Summer Gap” Utilization with Biochar and Legumes

To reduce reliance on scientific fertilizer due to rapid increase of fertilizer prices and environmental constraint, it necessary to improve crop productivity and soil fertility on sustainable basses. Utilization of “summer gap” through biochar and legumes have pleasant effects on improving crop productivity and soil fertility on long term basses. Two years’ field experiments were conducted on wheat and maize crops with “summer gap” utilization with legumes and biochar at research farm of agronomy, the University of Agriculture Peshawar during 2011–2013. Wheat-maize-wheat cropping system was followed with the adjustment of legumes in “summer gap” (land available after wheat harvest till maize sowing). Legumes i.?e. mung bean, cowpea and Sesbania with a fallow were adjusted in the “summer gap” with and without biochar application. Biochar was included at the rate of 0 and 50?t?ha^-1 with four N levels of 0, 90, 120, 150 and 0, 60, 90, 120?kg?ha^-1 to subsequent maize and wheat crops, respectively. In legumes’ experiment, biochar increased fresh and dry fodder yield in cowpea and Sesbania, grain and biological yields in mung bean. In maize experiments, biochar improved grain yield. Nitrogen application increased grain and biological yields. In wheat experiments with increasing nitrogen level enhanced biological and grain yields. It is concluded that use of biochar and legumes in “summer gap” improve overall farm productivity and soil fertility on sustainable basses.