In this paper, we study the incorporation of the commensalism interaction and harvesting on the Lotka–Volterra food chain model. The system provides one commensal prey, one harvested prey, and two predators. A set of preliminary results in local bifurcation analysis around each equilibrium point for the proposed model is discussed, such as saddle-node, transcritical and pitchfork. Some numerical analysis to confirm the accruing of local bifurcation is illustrated. To back up the conclusions of the mathematical study, a numerical simulation of the model is carried out with the help of the MATLAB program. It can be concluded that the system's coexistence can be achieved as long as the harvesting rate on the second prey population is

The interplay of predation, competition between species and harvesting is one of the most critical aspects of the environment. This paper involves exploring the dynamics of four species' interactions. The system includes two competitive prey and two predators; the first prey is preyed on by the first predator, with the former representing an additional food source for the latter. While the second prey is not exposed to predation but rather is exposed to the harvest. The existence of possible equilibria is found. Conditions of local and global stability for the equilibria are derived. To corroborate our findings, we constructed time series to illustrate the existence and the stability of equilibria numerically by varying the different values

من المؤسف حقا ان نجد أنفسنا نعيش في ظروف عصيبة لم تشاهده أعيننا ولم تطرأ على مسامعنا من قبل، وجاء الاحتلال البغيض بكل تبعاته السلبية افرز عنه اليوم تفرقاً ملحوظا وصراعا اليماً وتناحراً أضر بمكانتنا ووحدتنا،  ولنا في كل يوم مصيبة وعويل، حتى صارت عبارة عن مذاهب وطوائف وأشخاص، تتنازعهم الأهواء والخرافات والتقليد والتعصب وأمراض أخرى، وباتت تلك الأشلاء يلعن بعضها بعضاً وينفي أحدها الآخر.

وص

Find a study in the relationship between geography and medicine and a variety of sources, this study multiple. Valjgraveh is the image of the earth recipe haunted them and which of the seven regions and seas and mountains, prairies, rivers and cities geographical study of the Earth as the abode of the person or is the study of the natural environment of the human race and the geographical that analyzes the different factors that make up the natural environment and examines the impact of each factor separately and then the effects of all factors combined to human life and health and activity.

Resumen

     El Ultraísmo es un movimiento literario que comenzó en España a finales de 1918 y continuó hasta el año 1922. Este movimiento, que representó la contribución de España al Vanguardismo literario, que en la primera parte del siglo XX surgió en toda Europa, se desarrolló no tanto a través de los libros, cuanta a través de las revistas literarias de la época.

La creacionista es, sin duda, la escuela que dio a Ultra mayores aportes. Por esta razón, en las literaturas de Vanguardia se funden, y a veces también se confunden, con frecuencia, Ultraísmo y Creacionismo. Los dos movimientos eran como una revo

This study analyzes how to make use of the resources in the marshlands of Iraq and how to utilize them, especially after the water returns to these areas and they are revitalized. We take an example of AL- Saheen Marsh and plan an ideal tourist resort there. This example can further expand to include other parts of the marshlands. The resort will utilize the local environment and tourist characteristics as it will have a feel and architectural resemblance to the houses and buildings that are currently built there. In addition the transportation methods will be the same as those used by the locals. Yet the resort will still posses all the facilities required by a modern tourist resort that includes all the services that will make

The research deals with the lyrical introduction in the commentary of Tarfa bin al-Abd as a formative system characterized by flexibility and richness of imagination, which achieved a formative treatment and a unique construction within the structures of the structural and semantic language. I dealt with the poetic verses represented by the lyrical introduction as a formative hypothesis, basing its goal on a methodological framework distributed on the problem that was summarized by the following question: Is it possible to look at the poetic pattern within the pre-Islamic poem / hanging blinking as a model, in its plastic dimensions and to identify the stylistic treatment that achieves the formation space within the poetic text. The rese

The research aims to build an educational program - learning, according to the concepts of renewable energy and nanotechnology And knowledge of its impact on the technological enlightenment when the third phase students in the Department of Chemistry, and to verify the goal and put the researcher null hypothesis the following: No Statistically significant difference at the level (0.05) between the average scores of the experimental group students who are studying material nanotechnology and renewable energy program Altalima- learning and the average score for the control group of students who are studying the same article the usual way in technological enlightenment. The search was limited to the third row in the Department of Chemistry,