Rafidain Journal of Science

Four cultivars of durum wheat (Triticum durum Desf) were used in two crosses, the first, Leeds x Waha and the second Azeghar x Om rabi-3. The parent generations, first and second filial generations and first and second back crosses from each cross were used to study gene action, heritability, average degree of dominance and expected genetic advance for plant height, number of spikes, grain yield, weight of 100 grains and number of grains per spike. The results revealed that additive dominance model was adequate for weight of 100 grains in the two crosses, while additive, dominance and epistatic gene action played a significant role in the inheritance of other traits. Most of the studied traits revealed over dominance and high to medium narrow sense heritability. The values of expected genetic advance as percentage of the mean indicated that selection in the second filial generation will be effective to improve most of the studied traits.

Keywords: Gene

The present study was conducted on Staphylococcus aureus isolated from clinical and subclinical cases of mastitis in cows. Isolates were diagnosed by conventional and biochemical tests and API kit which was used to confirm the identification of Staph. aureus. Antibiotic resistance of these bacteria were tested against Penicillin, Gentamicin, Oxacillin, Tetracycline, Erythromycin, methicilin, vancomycin and the heavy metals like cadmium chloride, zinc chloride, mercury chloride and copper. The genetic transformation of the standard strain of E. coli k12JM83 was done with the plasmid DNA purified from these study isolates. The results revealed that the location of antibiotic resistance genes were found to be on plasmid. Transformants were obtained at a frequency of (0.8 – 2.0) × 10-4. The results showed that location of heavy metals resistance genes were located on plasmid DNA also.

Three generations (F2 , B1 and B2) of two crosses between durum wheat varieties viz. (Leeds X Waha) and (Azeghar X Omrabi), were used to estimate: (1) phenotypic and additive genotypic correlations between grain yield and its components and among components; (2) Direct and indirect effects of each of yield components on grain yield through path coefficient analysis; (3) the relative importance of components contributing to grain yield. The results showed that phenotypic and additive genotypic correlations in the two crosses were: (1) positive and significant between grain yield and its components (number of spikes, 100 grain weight and number of grains per spike). (3) negative and significant between the components. The value of determination coefficient as percent indicated that the contributing to grain yield were number of spikes, 100 grain weight and their joint effects, therefore, can be used as selection index in the program of wheat breeding.

The study aims were to investigate the effect of passive smoking on the changes in the level of glycogen in mice. The mice were exposed for (2 to 4) months to passive smoking, for 2 to 4 hour's daily. The intensity of carbohydrate and glycogen reaction by increasing the amount of smoking and histochemical stains was decreased with the lapse of time to exposure of passive smoking as compared with the group of control.

This study includes the investigation of the ability of some gram positive and gram negative bacterial species to produce slime layer which play a role in biofilm formation and complication of pathogenic infections and resistance to antibiotic therapy.
Thirty five bacterial isolates were used in this study, they include: Staphylococcus aureus (14 isolates), Pseudomonas aeruginosa (7 isolates), Escherichia coli (6 isolates), Proteus mirabilis (3 isolates), Salmonella spp. (2 isolates), Enterobacter aerogenes, Klebsiella pneumoniae, Serratia spp.
Three methods were used to detect slime layer production which include: Congo red agar medium (CRA), modified congo red agar method (mCRA), and Microtiter (MTP) method.
The results showed that there is no differences between Congo red agar and modified Congo red agar methods. Microtiter plate method was more sensitive for slime layer detection as the rate of production was 51.429% from all isolates as compared with 31.429% positive results in Congo red agar method. There are clear differences in moderate and negative results for both methods.

The rate of bromination of 1,3-diaryl -2-propen-1-one (a1) and its derivatives p-bromo acetophenone (a2), p-chloro acetophenone (a3), p-methoxy acetophenone (a4), p-nitro acetophenone (a5), p-chloro benzaldehyde (a6) and p-nitro benzaldehyde (a7) had been studied in chloroform. The study indicated first order dependence on each of reactants with rates (a5 > a3 > a2 > a1 > a4 ) and (a1 > a7 > a6) at any temperature. The effect of substituents on the rate showed that electronic factors, inductive and conjugative effects play a reasonable role on the stability of the intermediates. Suggested mechanisms, which are consistent with the results have been postulated and suitable rate laws in consonance with the suggested mechanisms have been derived.

The assay is based on the reaction of nitrite in acidic medium with
m-nitroaniline to form the corresponding diazonium ion which is coupled with
N-(1-naphthyl)ethylenediamine to form a stable purplish azo dye that shows maximum absorption at 530 nm. Beer's law is obeyed over the concentration range 0.04-1.0 ppm. The molar absorptivity is (4.6x104l.mol-1.cm-1), and Sandell's sensitivity index of (0.1 ng. cm-2).
The proposed method has been applied to the determination of nitrite in meat, water and soil.

In this research, we try to study the fatigue resistance of coated mild steel 1020 AISI. The alloy was coated with Al in single process using pack cementation technique and Ni using electrodeposition technique. Both processes were also used for coating the same alloy (double layer coating). The fatigue resistance of these coating was compared with the base alloy and with those subjected to a heat treatment at the same conditions of time and temperature. The aim of this study was to understand the effect of the temperature and coating type on the fatigue life.
The results obtained, based on XRD, Fatigue test, optical microstructure and hardness measurement, that the temperature of heat treatment played the major rule of fatigue life reduction. This can be attributed to the phase transformation of α­ ferrite steel to pearlite ( ferrite + cementite).
The results also showed that the coating types have a very important effect on fatigue life. The coatings performed at high temperature (aluminizing) revealed a negative effect on the fatigue life. This is due to the formation of a new brittle and less ductility of Fe-Al phase on the alloy surface. The electrodeposition of Ni leads to a positive effect which is due to an improvement in surface conditions of the alloys via filling the voids or other defects which are present at the surface. The double layer coating (Ni-Al) applied to some specimens shows some improvement in fatigue resistance, in comparison with a single aluminized specimen. This was attributed to the formation of multiphase layer consisting of Fe-Al and Ni-Al intermetallic compound.

An electromagnetic projector lens of double air gap with identical four poles and single coil has been designed. The projector focal length has been minimized to its lowest value, in order to obtain higher magnification and resolution by reducing the air gap width and the axial bore diameter. The single coil was divided in to two coils of equal area and number of turns. It was found that the projector lens properties for the single coil in comparison with that of the double coils were identical. Moreover, the radial and spiral distortions were reduced at the minimum value of the projector focal length when the lens of double air gap was used and the direction of the current was reversed, which led to attaining this lens the best image formation.

UV- visible spectrophotometer was used to determine the optical properties of the dental x-ray radiation films poly (vinyl chloride). The films were irradiated with varying doses of ultraviolet radiation UVc with 245nm. Optical absorbance peaks Abs. ranged from (0.032- 0.073), the peaks of extinction coefficient ko ranged from (1.2×10-5- 2.8×10-5), while the peaks of the real dielectric constant ε1 were found to be between the (2.2- 3.2), and the of the optical conductivity σ ranged from (1.6×1010 sec-1 - 4.4×1010 sec-1). The above data were obtained for lower radiation dose (102859 erg/mm2) and higher radiation dose (720014 erg/mm2). The results showed that there is a direct correlation between the optical properties and radiation dose. The results revealed that there is a high possibility for using the dental X-ray radiation films as dosimeters of UVc- radiation.