Flame retardancy,Thermal and mechanical properties of Kenaf fiber reinforced Unsaturated polyester/Phenolic composite

Unsaturated polyester (UP) resin has been blended with phenolic resin (PF) resole type at various ratios to obtain a homogeneous blend with improved flame resistance compared to its parent polymers. The polymer blend was reinforced with 20 wt% kenaf using hand lay out technique. Fourier transform infrared spectroscopy (FT-IR) was used to characterize changes in the chemical structure of the synthesized composites. The thermal properties of the composites were investigated using thermogravimetric analysis (TGA). The thermal stability of UP/PF kenaf composites co-varies with the PF content, as shown by the degradation temperature at 50 % weight loss. The char yield of the composites increases linearly with PF content as shown by the TGA results. The flammability properties of the composites were determined using the limiting oxygen index (LOI) and UL-94 fire tests. The LOI increased with the PF content while the composites exhibit improved flame retardancy as demonstrated by UL-94 test. The mechanical and morphological properties of the composites were determined by tensile test and scanning electron microscopy (SEM), respectively. The tensile strength and the Young’s modulus of the blend/composites slightly decreased with increasing PF content albeit higher than PF/kenaf fiber composites.     

Estimation of heterotic components for lactation traits and reproductive performance in three crossbreeding trials of Holstein cattle with German Friesian raised under hot climatic conditions

Lactation traits and reproductive performance of three trials of crossing Holstein cattle (H) and German Friesians (F) raised in a hot climatic were evaluated. The first 90-day (M90), 305-day (M305) and total milk yield (TMY), 305-day milk yield per day of calving interval (MCI1), total milk yield per day of calving interval (MCI2) along with length of lactation period (LP), age at first calving (AC1) and calving interval (CI) were used. For these traits, a genetic model was applied for each trial separately to obtain estimates of individual (G^I) and maternal (G^M) additive effects, individual (H^I) and maternal (H^M) heterosis and individual recombination effect (R^I). Data of 8045 normal lactations from the three trials were analysed. Among the crossbreds obtained in the three trials, cows of ¾H¼F ranked first in their lactational performance. Estimates of G^I and G^M were generally large and in favour of H cows (daughters) and dams for most milk-yield traits, CI and AC1 in the three trials. Estimates of H^I in crossbred cows for milk traits, CI and AC1 were mostly negative and reveal that crossing F with H was associated with a reduction in milk-yield traits, shorter CI and earlier AC1 along with longer LP in the three trials. Estimates of H^M for milk yields, LP, AC1 and CI in daughters of crossbred dams were mostly negative. Recombination losses in crossbred cows were negative for milk-yield traits, AC1 and CI in most cases.     

Synthesis and characterization of novel organo-soluble poly(ether-imide)s containing bulky moiety of triphenyl methane in the main chain

This paper describes the synthesis of novel thermally stable and organo-soluble poly(ether-imide)s (PEIs) by polycondensation reaction of a new synthesized diamine with different dianhydrides. Bis [4-(4-amino phenoxy)-2,5-dimethyl phenyl] paratolyl methane (6) as a new compound containing ether groups and bulky moiety of triphenyl methane was successfully prepared by a three step reaction. First, the diol compound (3) was prepared by a solvent free reaction of 2,5-dimethylphenol (1) with 4-methylbenzaldehyde (2). Then, the diol (3) was converted to dinitro (5) by reaction with 4-fluoronitrobenzene. Finally, dinitro (5) was reducted through the reaction with Pd/C 10 %. The structure of diamine (6) and resulting poly(ether-imide)s (8a-d) confirmed by ¹HNMR, FTIR spectroscopy and elemental analysis (CHN). Also the properties of poly(ether-imide)s (8a-d) were investigated by mean of thermal gravimetric analysis (TGA), differantial thermal gravimetric (DTG), differential scanning calorimetry (DSC), solubility tests and inherent viscosity. The resulted polymers show excellent thermal stability, good solubility in aprotic polar solvent and inherent viscosities between 0.37-0.50 dl/g.     

Effect of surgery for cannula implantation into the hypothalamus on the behaviour and neural activity of broiler chicks

1.?The effects of a surgical operation, to implant a guide cannula in the chick hypothalamus for microdialysis, on behavioural responses and neural activity in broiler chicks are described.

2.?General behavioural activities (feeding, preening, sitting, drinking, cage pecking and beak wiping), open field and locomotor activity tests were conducted to evaluate the effects related to surgery in the immediate 4 d following this procedure. Perfusion of Ringer solution with high K⁺ after 4 d of guide cannula implantation was used to estimate the neural activity resulting from surgery through stimulation of monoamine release by in vivo brain dialysis.

3.?The results of direct behavioral observations indicated that the stress provoked by surgical guide cannula insertion caused behavioural alterations that are particularly evident in the immediate days following this procedure. Open-field tests on day 4 after surgery showed that, compared to the intact control chickens, the treated chicks had a shorter latency to ambulate and defecate, with more vocalisation. Locomotor activity was less in the treated chicks than inthe controls.

4.?After 4 d of guide cannula implantation, the serotonin concentration started to increase 30 min after the onset of perfusing high-K⁺ Ringer solution. It reached its highest value at one hour, suggesting that the 4 d after surgery is enough to alleviate some neurochemical dysfunction resulting from surgery. The results of behavioural observations, open-field and locomotor activity tests indicate that the surgical operation caused stress and fear in chicks which persisted up to 4 d.     

Evaluation of milk yield and some related maternal traits in a crossbreeding project of Egyptian Gabali breed with Spanish V‐line in rabbits

This study was conducted in a four‐year rabbit project that aimed to develop a synthetic line named Moshtohor (M) by crossing Sinai Gabali breed (G) with the Spanish V‐line (V). The G, V, F₁ (G × V), F₂ (G × V)² and M line were analysed. Traits of doe body weight at delivery (DBW), litter size at birth (LSB) and at weaning (LSW), milk production during the first, second, third and fourth week of lactation and total milk yield (TMY) were recorded. Data were analysed using a repeatability uni‐trait animal model to estimate the genetic parameters and estimable functions of genetic group effects. Based on them and the matrix of their variance–covariance, the crossbreeding parameters were also estimated. Estimates of heritabilities for all the studied traits were low ranging from 0.06 to 0.11 for DBW, LSB and LSW and from 0.0 to 0.06 for milk production traits. Permanent environmental effects were very low ranging from 0.0 to 0.10 for all the traits, except for DBW (0.41). Least square means of V line were superior (p < 0.05) in DBW (3253 versus 3037 g) and LSB (6.71 versus 6.28 young) relative to G breed. M line had superiority in LSB (6.94 young) compared with G breed. M line and G breed were better than V line for milk production traits (3415 and 3236 versus 2893 g for TMY). Significant effects of direct additive were observed for most traits studied (ranged from ?6.8 to 20.7%). Effects of individual heterosis for most milk production traits were significant and ranged from 2.1 to 13.9%, but they were not significant for DBW, LSB and LSW. On the opposite side, effects of maternal heterosis for all the traits were not significant.     

Impact of the catalytic activity of iodine on the granule morphology, crystalline structure, thermal properties and water solubility of acetylated corn (Zea mays) starch synthesized under microwave assistance

By activating corn starch with acetic acid and using acetic anhydride as an esterifying agent, starch acetates with increasing degrees of substitution were obtained using microwave assistance when the amount of iodine varied from 0.5 to 1.75 mmol. The study of Fourier Transform Infrared (FT-IR) spectra, X-ray diffraction pattern, thermal properties, granule morphology, water absorption and solubility, revealed important changes on the physical properties of the obtained products related to the increase of the iodine content. As shown by the scanning electron microscope (SEM), a specific structure on the granule surface was discerned for each amount of iodine. By its exo-corrosive action on starch, iodine indirectly induced loss of crystallinity, decrease of the glass transition and melting temperatures, and a progressive reduction in the water absorption and water solubility index of the modified products. Starch esters with better hydrophobicity and good processability for bio-based material applications were synthesized. Alternatively, the variation in the concentration of the iodine could also be of interest in special purposes, in which starch granules with controlled surface porosity are needed.     

In vitro cytochrome P450-mediated hepatic activities for five substrates in specific pathogen free chickens

Total hepatic microsomal cytochrome P450 (CYP) content as well as in vitro CYP mediated activities for five substrates [bufuralol 1-hydroxylation, ethoxyresorufin O-deethylation, S-mephenytoin 4-hydroxylation, testosterone 6beta-hydroxylation, and tolbutamide hydroxylation] were measured in specific pathogen free male Japanese leghorn chickens and male beagle dogs. The Vmax, Km and intrinsic clearance (Vmax/Km) for these substrates were calculated and compared between animal species in order to evaluate the drug catalytic activity in chicken liver. The total CYP content in chicken (0.296 +/- 0.04 nmol/mg microsomal protein) was close to levels reported for other species including humans, cats, pigs and some nonmammalian vertebrates (e.g. snakes, frogs and trout fish), but was lower than levels measured in dogs (1.11 +/- 0.22) or recorded in guinea-pigs, hamsters, monkeys, mice, rabbits, rats, horse and ruminants. Bufuralol 1-hydroxylation, ethoxyresorufin O-deethylation, S-mephenytoin 4-hydroxylation, and testosterone 6beta-hydroxylation were lower in chickens than in dogs based on intrinsic clearance. On the other hand, tolbutamide hydroxylation was markedly higher in chickens than in dogs.     

Suppression of Stress Responses in Siberian Sturgeon,Acipenser baeri,Juveniles by the Dietary Administration of Bovine Lactoferrin

A study was performed to investigate the influence of dietary lactoferrin (LF) on growth and stress responses of juvenile Siberian sturgeon. Fish were fed six experimental diets (0, 100, 200, 400, 800, and 1600 mg LF/kg diet) for 10 wk. At the end of the experiment, fish were exposed to an acute stressor of 2‐min air exposure. The levels of cortisol, glucose, and lactate were measured before and at 1, 3, 6, 9, 12, and 24 h after stress. LF supplementation did not influence the fish growth. Cortisol and lactate, but not glucose level, were significantly affected by dietary LF. Cortisol levels in the control group rose twofold 1 h after stress and were significantly higher than that in LF groups. Moreover, the lowest level of cortisol at all sampling times (prestress and poststress) was observed in fish fed 400 mg LF/kg diet. Lactate concentrations in sturgeon fed 400 mg LF/kg markedly rose 1 h after stress, albeit changes in other LF groups were not significant. Results of this study show that dietary LF can suppress the stress responses in Siberian sturgeon, while 400 mg LF/kg diet appears to be an effective dietary level for this species to reduce stress.     

Effect of dietary α‐tocopherol on the bioavailability of lutein in laying hen

Lutein and its isomer zeaxanthin have gained considerable interest as possible nutritional ingredient in the prevention of age‐related macular degeneration (AMD) in humans. Egg yolk is a rich source of these carotenoids. As an oxidative sensitive component, antioxidants such as α‐tocopherol (T) might contribute to an improved accumulation in egg yolk. To test this, chickens were fed lutein esters (LE) with and without α‐tocopherol as an antioxidant. After depletion on a wheat–soya bean‐based lutein‐poor diet for 21 days, laying hens (n = 42) were equally divided into three groups and fed the following diets for 21 days: control (basal diet), a LE group (40 mg LE/kg feed) and LE + T group (40 mg LE plus 100 mg T/kg feed). Eggs and blood were collected periodically. Carotenoids and α‐tocopherol in yolk and blood plasma were determined by HPLC. Egg yolk was also analysed for total carotenoids using a one‐step spectrophotometric method (iCheck^(?)). Lutein, zeaxanthin, α‐tocopherol and total carotenoids in egg yolk were highest after 14 days of feeding and decreased slightly afterwards. At the end of the trial, eggs of LE + T group contained higher amount of lutein (13.72), zeaxanthin (0.65), α‐tocopherol (297.40) and total carotenoids (21.6) compared to the LE group (10.96, 0.55, 205.20 and 18.0 mg/kg, respectively, p < 0.05). Blood plasma values of LE + T group contain higher lutein (1.3), zeaxanthin (0.06) and tocopherol (20.1) compared to LE group (1.02, 0.04 and 14.90 mg/l, respectively, p < 0.05). In conclusion, dietary α‐tocopherol enhances bioavailability of lutein reflecting higher content in egg yolk and blood plasma. Improved bioavailability might be due to increased absorption of lutein in the presence of tocopherol and/or a greater stability of lutein/zeaxanthin due to the presence of α‐tocopherol as an antioxidant.