‎  Since the first outbreak in Wuhan, China, in December 31, 2019, COVID-19    pandemic  ‎has been spreading to many countries in the world. The ongoing COVID-19 pandemic has caused a ‎major global crisis, with 554,767 total confirmed cases, 484,570 total recovered cases, and ‎‎12,306 deaths in Iraq as of February 2, 2020. In the absence of any effective therapeutics or drugs ‎and with an unknown epidemiological life cycle, predictive mathematical models can aid in ‎the understanding of both control and management of coronavirus disease. Among the important ‎factors that helped the rapid spread of the ep

Essential oils of eucalyptus leaves and clove buds were isolated and tested for their bioherbicidal potential on different annual weed species. Gas Chromatography-Mass Spectrophotometry analysis (GC-MS) identified thirteen compounds representing around 87.11% of the total isolated eucalyptus oil. The main constituent was 1,8-cineole, which accounted for 68.15% of the total identified compounds. As for clove oil, eleven compounds were identified, representing 90.03% of the total compounds. Eugenol was the dominant compound and accounted for 73.89%. The bioherbicidal efficacy of the two oils and their combinations by three concentrations (2.5, 5, and 10%) were tested on four weedy species, namely Chenopodium album, Raph

In this paper,  a Sokol-Howell prey-predator model involving strong Allee effect is proposed and analyzed. The existence, uniqueness, and boundedness are studied. All the five possible equilibria have been are obtained and their local stability conditions are established. Using Sotomayor's theorem, the conditions of local saddle-node and transcritical and pitchfork bifurcation are derived and drawn. Numerical simulations are performed to clarify the analytical results

The Present Work includes the study of the population dynamics of Armadillidium vulgare in AL- Jadiriya region in Baghdad. Monthly samples were collected using a quadrat 0.0625 m2 from November 2007 to November 2008.. The population density of A.vulgare, ranged from 880 ind/m2 in May to251 ind/m2 in January respectively. This species showed high aggregation dispersion in the study area. The sex ratio showed that the number of females were more than that of males and significantly differd (P < 0.05) during the reproductive months. Furthermore, it was found that the juveniles of species were present at most time of the year, But the large sized groups have been observed during summer and spring. And showed a positive linear correlations betwe

Abstract:

      In this research we discussed the parameter estimation and variable selection in Tobit quantile regression model in present of multicollinearity problem. We used elastic net technique as an important technique for dealing with both multicollinearity and variable selection. Depending on the data we proposed Bayesian Tobit hierarchical model with four level prior distributions . We assumed both tuning parameter are random variable and estimated them with the other unknown parameter in the model .Simulation study was used for explain the efficiency of the proposed method and then we compared our approach with (Alhamzwi 2014 & standard QR) .The result illustrated that our approach

In this paper, a mathematical model consisting of the prey- predator model with treatment and disease infection in prey population is proposed and analyzed. The existence, uniqueness and boundedness of the solution are discussed. The stability analyses of all possible equilibrium points are studied. Numerical simulation is carried out to investigate the global dynamical behavior of the system.

In this paper, an eco-epidemiological model with media coverage effect is proposed and studied. A prey-predator model with modified Leslie-Gower and functional response is studied. An  -type of disease in prey is considered.  The existence, uniqueness and boundedness of the solution of the model are discussed. The local and global stability of this system are carried out. The conditions for the persistence of all species are established. The local bifurcation in the model is studied. Finally, numerical simulations are conducted to illustrate the analytical results.

The mathematical construction of an ecological model with a prey-predator relationship was done. It presumed that the prey consisted of a stage structure of juveniles and adults. While the adult prey species had the power to fight off the predator, the predator, and juvenile prey worked together to hunt them. Additionally, the effect of the harvest was considered on the prey. All the solution’s properties were discussed. All potential equilibrium points' local stability was tested. The prerequisites for persistence were established. Global stability was investigated using Lyapunov methods. It was found that the system underwent a saddle-node bifurcation near the coexistence equilibrium point while exhibiting a transcritical bifurcation