Background: The vasoconstricting agents: nor-adrenaline and 5- hydroxytryptamine
(5-HT) have a stimulant action on smooth muscle contractility of the rat vas deferens.
Objective: This study aimed to investigate the effect of exposure to continuous
darkness and continuous light on the contractility of the vasa deferntia smooth
muscles from rats to applied nor-adrenaline and 5-HT.
Method: Male albino wistar rats were divided into 3 experimental groups. Group 1:
Control animals, were exposed to the ordinary photoperiod each day. Group 2: Rats
were kept in a dark room. Group 3: In a room under a bright artificial light.
All animals were killed after 4 weeks.
Results: Vasa deferentia preparations from continuous dark group of rats exhibited a
reduced reactivity with a significant lower maximal response to 5-HT than those from
control rats. The maximal response in the control vasa deferentia preparations were
nearly doubled compared with that of the continuous dark preparation where as they
responded to exogenous nor-adrenaline with no significant difference from those of
continuous dark animals. Vasa deferentia of continuous light animals responded with
decreased reactivity and a smaller maximal response to both vasoconstrictors
compared with that of control animals.
Conclusion: It is concluded that changes in the rhythm of the photoperiod have
considerable effects on the reactivity of the vasa deferentia smooth muscle from rats
to applied nor-adrenaline and 5-HT
Mercury is a heavy metal that is extremely toxic. There are three types of it: inorganic, organic, and elemental. Mercury in all its forms has been shown to have harmful effects on living things. It can multiply its concentration from lower to higher trophic levels and accumulate in the body's various tissues. Aquatic organisms bodies have been exposed to mercury mostly through various human activities. The largest source of mercury pollution in the air is thermal power plants that mostly use coal as fuel. It is carried to a body of water after being deposited on the ground surface from the air. The way it enters the food chain is through aquatic plants and animals. Mercury accumulations in the kidney, liver, gills, or gonadal tissu
... Show MorePraise be to God, Lord of the worlds, and prayers and peace be upon our master Muhammad and upon his family and companions.
We see human societies differ from one society to another in organizing social life, and each according to the foundations and rules prepared by the main thing in the welfare and prosperity.
That is why we see eastern societies differ from western societies in many patterns and various ways of reaching that sophistication, until Islam came and gave the proper model in raising society at that time to the best and highest social levels, because it is based on heavenly rules and foundations and not status as in previous civilizations.
And when the Islamic community has
Urban wetlands are one of the complex systems that provide many economic, social and environmental services to the city. In this research, the most important services provided by urban wetlands from the point of view of the urban planner were reviewed, and the types of these lands and their divisions according to the type of services provided by each type were presented. Environmental is represented in its ability to reduce the dangers of floods, mitigate the climate and reduce its negative impacts, purify water and deplete a lot of suspended impurities and pollutants, and social services such as recreational areas and beautiful landscapes that inspire joy and reassurance in the soul, as well as cultural areas and sports activities for m
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We report a method of converting non-conductive plastic surfaces into conductive by plating either copper electroless or copper electroplating -carbon black containing bending Agent onto Perspex plastics . Various approaches have been studied in order to comparing properties of the plated copper for two methods such as scanning electron microscopy (SEM),thickness, roughness, porosity, tensile Strength and elongation. The results show that the surface of electroplating was uniform, compact, and continuous and it had an obvious metallic sheen, while the surface of plated copper for electroless for it had many pores. Also observed that the coating was composed of small cells. Thes
... Show Moreكان لنهاية الحرب الباردة وعولمة العالم على وفق رؤية كونية تتجاوز حدود ومفاهيم السيادة الوطنية والقومية الاثر الواضح في ترتيب العلاقات الدولية , واصبحت تلك العلاقات تدور حول محورين الاول .. هو الاعتماد المتبادل بين الدول من اجل الوصول الى خطوط مشتركة للمصالح المختلفة بين هذه الدول . والآخر.. هو تبعية الدول الضعيفة للدول القوية لافتقار الاولى توفير الحاجيات الى مواطنيها . هذا يشير الى نشأة علا
... Show More. The concepts of structural flexibility became one of the important goals in the design phases to reach high performance in architecture. The pioneering projects and ideas that linked architecture with technologies and scientific innovations appeared, with the aim of reaching projects that mix the concepts of flexibility with the development of machine thought and modern technology to meet the functional, environmental, and aesthetic requirements for human wellbeing. The aim of this paper is to identify the mechanisms used in order to reach flexible structural systems capable of accommodating technological changes and developments. The research hypothesizes that the structural design according to the concepts of flexibility achieves high s
... Show MoreMercury is a heavy metal that is extremely toxic. There are three types of it: inorganic, organic, and elemental. Mercury in all its forms has been shown to have harmful effects on living things. It can multiply its concentration from lower to higher trophic levels and accumulate in the body's various tissues. Aquatic organisms bodies have been exposed to mercury mostly through various human activities. The largest source of mercury pollution in the air is thermal power plants that mostly use coal as fuel. It is carried to a body of water after being deposited on the ground surface from the air. The way it enters the food chain is through aquatic plants and animals. Mercury accumulations in the kidney, liver, gills, or gonadal tissues of sp
... Show MoreIn this paper we find the exact solution of Burger's equation after reducing it to Bernoulli equation. We compare this solution with that given by Kaya where he used Adomian decomposition method, the solution given by chakrone where he used the Variation iteration method (VIM)and the solution given by Eq(5)in the paper of M. Javidi. We notice that our solution is better than their solutions.
In this paper, new method have been investigated using evolving algorithms (EA's) to cryptanalysis one of the nonlinear stream cipher cryptosystems which depends on the Linear Feedback Shift Register (LFSR) unit by using cipher text-only attack. Genetic Algorithm (GA) and Ant Colony Optimization (ACO) which are used for attacking one of the nonlinear cryptosystems called "shrinking generator" using different lengths of cipher text and different lengths of combined LFSRs. GA and ACO proved their good performance in finding the initial values of the combined LFSRs. This work can be considered as a warning for a stream cipher designer to avoid the weak points, which may be f
... Show MoreIn this study, we present a new steganography method depend on quantizing the perceptual color spaces bands. Four perceptual color spaces are used to test the new method which is HSL, HSV, Lab and Luv, where different algorithms to calculate the last two-color spaces are used. The results reveal the validity of this method as a steganoic method and analysis for the effects of quantization and stegano process on the quality of the cover image and the quality of the perceptual color spaces bands are presented.