When the guard honey bees, Apis mellifera L., form a clump at the hive entrance or on the flight board, the oriental hornet, Vespa orientails L., either creeps toward the clump or hovers over it in order to take a bee. Once the hornet creeps, only few bees facing the hornet become alert, rock their heads and antennae, open their wings, and take a posture of defense. The rest of the clump stays listless without any signal of concern. However, the clump stays dense and the defending bees do not detach themselves neither from the rest of the clump nor from each other. For this reason, it is very difficult for the hornet to grab a bee unless the latter makes a “mistake” by detaching herself from other adjacent bees. If the hornet grabs such a bee, the other defending bees will not attack the hornet to free that bee even when the latter is one centimeter from the others. The defending bees can capture the hornet only when the latter grabs one of them which stands very close to the others. The hornet seems very “aware” of such a situation; hence she seldom becomes a captive. On the other hand, hovering over the clump makes it easier for the hornet to grab a bee. The hovering puts all the clump, rather than part of it, on alert. If the hornet is persistent, which is not often the case, then the clump will no longer be dense. The bees will panicly disperse all over the flight board; hence the hornet can find a detached bee and grabs it easily. The hornet also waits on wing in front of the hive to capture an outgoing or incoming flying bee but the latter usually maneuver to escape. Also, foraging bees reduce their activity during main hours of hornet presence. Among the main factors reducing the hornet impact are the continuous chasing of hornets to each other and the non-persistent attempts of the hornets when they attack bee clumps.
Infertility can be detected when the couples have not completed pregnancy after a year or more of normal coitus. So, in order to treat infertility, there are many supported reproductive techniques are in practice. The success rate of these techniques depends upon the way by which preparation of the paternal semen sample. Over the past 30 years, the manual has been standard as providing global standards and has been used extensively by research and clinical laboratories throughout the world. The spermatozoa of all placental (eutherian) mammals, including humans, are in a protective, no labile formal at ejaculation and are incapable of fertilization even if they are placed in direct contact with an oocyte. Accordingly, they must undergo a sub
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At the last two decades , The environment has witnessed tremendous changes in many fields with the huge competition , various technological development and customer satisfaction , that are reflected in economic units a doption for lean production system.
Lean accounting that has appeared as a response for change occurred of economic units adoption for changes occurred of economic units adoption for lean production instead of wide production system , has devised new performance measures suitable for economic units adoption for lean ideas: and helping in providing suitable information about evaluating economic unit performance , these measures are divided into three levels , cell level,value flow level , a
... Show MoreReading and analyzing Paula Vogel’s plays, the readers can attest that she achieves success in drama or theater because she is passionate about theater. Vogel is a modern American playwright who won the 1998 Pulitzer Prize for drama. Her success and insight in playwriting or in adapting do not come all of a sudden; she is influenced by many writers. Vogel is influenced by many American dramatists, including Eugene O’ Neill, Arthur Miller, Tennessee Williams, and Edward Albee, and by other non-American writers, including August Strindberg, Anton Chekhove, and Bertolt Brecht. Certainly, there were female playwrights who wrote preeminent plays and they influence Vogel as well. Nevertheless, dramas by female
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Introduction: Biliary atresia (BA) is a disease characterized by a biliary obstruction of unknown origin. Viral agents have been proposed in the aetiology of BA such as cytomegalovirus (CMV). This virus also considered as a one of agents that can infect the liver and cause hepatitis. The aim of this study was to determine the role of CMV in children with both chronic hepatitis (negative for hepatitis B and C) and have biliary atresia in the same time.Material and Methods: A retrospective study done on 13 liver tissue paraffin blocks of children with chronic hepatitis (negative for hepatitis B and C) and biliary atresia (extra and intra). The diagnosis was based on the presence of HCMV protein (pp65) by using immunohistochemistry.Res
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Electromechanical actuators are used in a wide variety of aerospace applications such as missiles, aircrafts and spy-fly etc. In this work a linear and nonlinear fin actuator mathematical model has been developed and its response is investigated by developing an algorithm for the system using MATLAB. The algorithm used to the linear model is the state space algorithm while the algorithm used to the nonlinear model is the discrete algorithm. The huge moment constant is varied from (-3000 to 3000) and the damping ratio is varied from (0.4 to 0.8).
The comparison between linear and nonlinear fin actuator response results shows that for linear model, the maximum overshoot is about 10%,
... Show MoreIn the name of Allah, the Beneficent, the Merciful.
Praise be to Allah, Lord of the Worlds and peace and blessings on the honest and trustworthy (Muhammad) and his family and his divine good companions.
The Islamic clothing is one of the requirements of the common and original innateness to humans; the innateness that is created by God to all people, Allah says, (So set thou thy face steadily and truly to the Faith: [establish] Allah's handiwork according to the pattern on which He has made mankind: no change [let there be] in the work [wrought] by Allah: that is the standard Religion: but most among mankind understand not) (1). Islam as a natural religion has ordered the Muslims to wear decently, Allah says, ( O Children of Adam!
A Spectroscopic study has been focused in this article to study one of the main types of active galaxies which are quasars, and to be more precise this research focuses on studying the correlation between the main engine of Quasi-Stellar Objects (QSO), the central black hole mass (SMBH) and other physical properties (e.g. the star formation rate (SFR)). Twelve objects have been randomly selected for “The Half Million Quasars (HMQ) Catalogue” published in 2015 and the data collected from Salon Digital Sky survey (SDSS) Dr. 16. The redshift range of these galaxies were between (0.05 – 0.17). The results show a clear linear proportionality between the SMBH and the SFR, as well as direct proportional between the luminosit
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The study aimed at identifying the level of administrative work quality of private Schools principals at Southern Governorates of Palestine from the teachers' point of view in their schools. To achieve the objectives of this research, a questionnaire was prepared by the researcher consisted of (28) items. It was applied to a sample of (350) teachers. The researcher adopted the descriptive-analytical approach. The results of the study showed that the degree to which principals of private schools in the southern governorates of Palestine practice Administrative Work Quality from the viewpoint of their teachers was very high, with relative weight (85.00%). The results also showed that there are statistically significant differences at the l
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