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 lower than its intrinsic growth rate. Further, the role of mutual interaction can lead to the stability of the proposed system.
Background: Melanin pigmentation of the gingiva appears in all ethnicities. Excessive pigmentation is an esthetic concern that has increased awareness about depigmentation procedures. This epidemiological study aims to find the correlation between skin color and gingival pigmentation in Sulaimani Governorate, Kurdistan/Iraq.
Subjects and Methods: A total of 820 apparently healthy and non-smokers, including 338 males and 482 females with healthy gingiva, aged between (18-40 years old) were enrolled in this study. Clinical examination on the participants’ gingivae was performed to assess color, and the distribution of pigmentations. Afterward the of participants skin color were
... Show MoreFifty snails of Paropeas achatinaceum specimens were collected and classified from four areas in Baghdad-Iraq from the period between June and July, 2017. The snails were divided into two groups (each group contain 25 snails). Two environment conditions were used in this study. Natural environment considered as control and experimental environment contains Citrus sinensis (L.) roots as snail’s source food. The comparison result between snail weights in the nature and experimental environment was not significant (0.497, 95% confidence interval [CI] 0.01209–0.02309). Also, the comparison between snail weights in the nature environment and the food mean weight was significant (0.014, 95% confidence interval [CI] 0.00591-0.04109), while the
... Show MoreTeaching techniques are the vehicles, which are used by teachers to help pupils learn and gain experiences and create positive classroom activities, as much as these techniques are varied, they lead to successful and fruitful learning in the foreign language. They help teachers achieve their objectives (Asowrth, 1985: 124).
The English language teacher's work is an active and purposeful one when he can plan carefully and frequently make the necessary changes in the contents and methods of teaching programme to fit the interest and needs of pupils. It seems that the majority of primary English teachers' interests does not go far in planning their work, and do not understand which o
... Show MoreIn the present work, the efficiency of Tri-octyl Methyl Ammonium Chloride (TOMAC) ionic liquid was investigated as new and green demulsifier for three types of Iraqi crude oil emulsions (Nafut Khana (NK), Kirkuk and Basrah). The separation efficiency was studied at room temperature and by using microwave heating technique. Several batch experiments were done to specify the suitable conditions for the emulsification and demulsification which were specified as 45 minutes and 3000 rpm for crude oil emulsification while the ionic liquid doses were (500,300,150,50) ppm and the conditions of microwave heating were 1000 watt and 50 second as irradiation time. The results were very encouraging especially for NK and Kirkuk crude oil emulsions whe
... Show MoreIn this work, we construct the projectively distinct (k, n)-arcs in PG (3, 4) over Galois field GF (4), where k 5, and we found that the complete (k, n)-arcs, where 3 n 21, moreover we prove geometrically that the maximum complete (k, n)-arc in PG (3, 4) is (85, 21)-arc. A (k, n)-arcs is a set of k points no n+ 1 of which are collinear. A (k, n)-arcs is complete if it is not contained in a (k+ 1, n)-arcs
Death is undoubtedly the theme of Don DeLillo’s White Noise. Murray Siskind, a College-on-the-Hill professor who is obsessed with the exploration and reinterpretation of American popular culture, talks about the Tibetan Book of the Dead, and the German mentor of Jack Gladney has been using the Egyptian Book of the Dead, translated into German. The core episode of the story is the Airborne Toxic Event, the associate of Heinrich (Jack’s teenage son), Orestes Mercator, dreams of becoming one of the great figures in the Guinness Book by challenging and confronting death by enclosing himself in a glass pen jam-packed with poisonous snakes, and Heinrich challenges an imprisoned mass murderer in a chess game. The scholarly expertise of Jack c
... Show MoreAsthma is a chronic respiratory disorder of airways characterized by inflammation, hyperresponsiveness, inflammatory cell infiltration, mucous secretion, and remodelling. Ammi majus is medicinal plant belong to family of Apiaceous which has anti-inflammatory and antioxidant activities. This study designed to investigate of anti-asthmatic activity of alcoholic extract of Ammi majus in improvement of asthma. Forty-eight healthy female mice divided to six groups Group I: the negative control group (distal water only), Group II: Positive control group (ovalbumin group), Group III: Ammi majus (64 mg/kg/day) with sensitization, Group IV:Ammi majus (128 mg/kg/day) with sensitization, Group V: Ammi majus (64 mg/kg/day) without sensitiza
... Show MoreThe General Company for Iraqi Cement is regarded as one of the companies that contribute to support the Iraqi economy. It contributes to provide the material of cement which fulfils the consumer and investment need in the markets in competitive prices and not to resort to the importing of the cement from abroad. That would save a great share of the purchase parity of the poor sectors of society. The estimation of production function will contribute to putting the company.
The application functions of the standard production of benefit critical to clarify the actual relationship between production & its components, & allow to clarify the i
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