In this paper, the aquatic food chain model, consisting of Phytoplankton, Zooplankton, and Fish, in the contaminated environment is proposed and studied. Modified Leslie–Gower model with Holling type IV functional response are used to describe the growth of Fish and the food transition throughout the food chain, respectively. The toxic substance affects directly the Phytoplankton and indirectly the other species. The local stability analysis of all possible equilibrium points is done. The persistence conditions of the model are established. The basin of attraction for each point is specified using the Lyapunov function. Bifurcation analysis near the coexistence equilibrium point is investigated. Detecting the existence of chao

                The characteristics of sulfur nanoparticles were studied by using atomic force microscope (AFM) analysis. The atomic force microscope (AFM) measurements showed that the average size of sulfur nanoparticles synthesized using thiosulfate sodium solution through the extract of cucurbita pepo extra was 93.62 nm. Protecting galvanized steel from corrosion in salt media was achieved by using sulfur nanoparticles in different temperatures. The obtained data of thermodynamic in the presence of sulfur nanoparticles referred to high value as compares to counterpart in the absence of sulfur nanoparticles, the high inhibition efficiency (%IE) and corrosion resistance were at high temperature, the corrosion rate or weig

Malaysia will be an ageing population by 2030 as the number of those aged 60 years and above has increased drastically from 6.2 percent in 2000 and is expected to reach 13.6 percent by 2030. There are many challenges that will be faced due to the ageing population, one of which is the increasing cost of pensions in the future. In view of that, it is necessary to investigate the effect of actuarial assumptions on pension liabilities under the perspective of ageing. To estimate the pension liabilities, the Projected Unit Credit method is used in the study and commutation functions are employed in the process. Demographic risk and salary risk have been identified as major risks in analyzing pension liabilities in this study. The sensitivity

     This research was conducted to measure the levels of asbestos fibers in the air of some dense sites of Baghdad city, which were monitored in autumn 2019. Samples collection was conducted via directing air flow to a mixed cellulose ester membrane filter mounted on an open‑faced filter holder using sniffer with a low flow sampling pump. Air samples were collected from four studied areas selected in some high traffic areas of Baghdad city, two of them were located in Karkh (Al-Bayaa and Al-Shurta tunnel) and two in Rusafa (Al-Jadriya and Al-Meshin complex), then analyzed to determine concentrations of asbestos. Measuring of levels of asbestos fibers on the filters was carried out via using scanning electron micros

Colloidal silver nanoparticles were prepared by single step green synthesis using aqueous extracts of the leaves of thyme as a function of different molar concentration of AgNO₃ (1,2,3,4 mM(. The Field Emission Scanning Electron Microscopy (FESEM), UV-Visible and X-ray diffraction (XRD) were used to characterize the resultant AgNPs. The surface Plasmon resonance was observed at wavelength of 444 nm. The four intensive peaks of XRD pattern indicate the crystalline nature and the face centered cubic structure of the AgNPs. The average crystallite size of the AgNPs ranged from 18 to 22 nm. The FESEM image illustrated the well dispersion of the AgNPs and the spherical shape of the nanoparticles with a particle size distribution be

The presented research investigated the pollen morphology of endemic Iraqi Hypericum species. The study revealed phenotypic features of pollen grains in the polar and equatorial views and their quantitative and qualitative characteristics. The results showed that the pollen grains of the genus Hypericum were radially symmetrical and isopolar, and their apertures were simple and tricolporate, except the species H. davisii, distinguished as tetracolprate. Dividing the studied species based on pollen grain sizes comprised two groups. Small pollen grains with an average length of the equatorial view ranged between 10–16 μm in H. lysimachioides and H. vermiculare. Medium-sized pollen grains with an average extent between 17–26 μm e

Q fever is an infectious disease of animals and humans, caused by globally distributed C. burnetii. In Iraq, there are no previous studies associated with the detection of the organism in cattle. An overall of 130 lactating cows were submitted to direct collection of milk samples. Initially, the samples of milk were tested using the molecular polymerase chain reaction (PCR) assay targeting three genes (16S rRNA, IS1111a transposase, and htpB). However, positive results (18.46%; 24/130) were detected only with the 16s rRNA gene. Concerning risk factors, the highest prevalence of C. burnetii was showed in the district of Badra (42.86%), whereas the lowest - in Al-Numaniyah and Al-Suwaira districts (P=0.025). There was no significant v

This study is carried out to investigate the prevalence of Coxiella burnetii (C. burnetii) infections in cattle using an enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) assay targeting IS1111A transposase gene. A total of 130 lactating cows were randomly selected from different areas in Wasit province, Iraq and subjected to blood and milk sampling during the period extended between November 2018 and May 2019. ELISA and PCR tests revealed that 16.15% and 10% of the animals studied were respectively positive. Significant correlations (P<0.05) were detected between the positive results and clinical data. Two positive PCR products were analyzed phylogenetically, named as C. burnetii IQ-No.5 and C. burnet