Background: Elastomeric chains are used to generate force in many orthodontic procedures, but this force decays over time, which could affect tooth movement. This study aimed to study the force degradation of elastomeric chains. Data and Sources: An electronic search on Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, LILACS, and PubMed was made, only articles written in English were included, up to January 2022.Study selection: Fifty original articles, systematic reviews, and RCTs were selected. Conclusion: Tooth movement, salivary enzymes, alcohol-containing mouthwash, whitening mouthwash, and alkaline and strong acidic (pH <5.4) solutions all have a significant impact on elastomeric chain force degradation. The fo

The aim of the current research is to construct a scale of emotional adjustment for kindergarten children and to set a standard for its evaluation. To achieve this, a scale consisting of (19) items was prepared. The mother of the child answered by adopting the method of self-report, which is expressed in the form of reporting terms, as each item represents a situation in the child's life and each situation has three alternatives to answer that represent various responses to the mentioned situation. One of the alternatives represents the emotionally adaptive response, which is given a degree (3), the second response expresses the emotional adjustment partly that took the degree of (2), and the third response expresses the weakness of emot

The bandwidth requirements of telecommunication network users increased rapidly during the last decades. Optical access technologies must provide the bandwidth demand for each user. The passive optical access networks (PONs) support a maximum data rate of 100 Gbps by using the Orthogonal Frequency Division Multiplexing (OFDM) technique in the optical access network. In this paper, the optical broadband access networks with many techniques from Time Division Multiplexing Passive Optical Networks (TDM PON) to Orthogonal Frequency Division Multiplex Passive Optical Networks (OFDM PON) are presented. The architectures, advantages, disadvantages, and main parameters of these optical access networks are discussed and reported which have many ad

This paper introduces a relationship between the independence of polynomials associated with the links of the network, and the Jacobian determinant of these polynomials. Also, it presents a way to simplify a given communication network through an algorithm that splits the network into subnets and reintegrates them into a network that is a general representation or model of the studied network. This model is also represented through a combination of polynomial equations and uses Groebner bases to reach a new simplified network equivalent to the given network, which may make studying the ability to solve the problem of network coding less expensive and much easier.

النظام السياسي اليمني : دراسة في المتغيرات الداخلية

Lorraine Hansberry’s A Raisin in the Sun (1959) appeared at the beginning of renewed political activity on the part of the blacks; it is a pamphlet about the dream of recognition of black people and the confusion of purposes and means to reach such recognition. It embodies ideas that have been uncommon on the Broadway stage in any period. Situations such as a black family moving into an all-white neighborhood were not familiar before this time; they were just beginning to emerge. In depicting this so realistically, Hansberry depends more on her personal experience as an African American embittered by social prejudices and discrimination. 

The speech act of refusals has been studied widely either alone or in relation to such areas as apology, requests, promotion, and invitation. The present study aims to investigate the strategies employed by Iraqi females in refusing marriage proposals. It attempts to explore their preferences to respond directly or indirectly in relation to their ages and educational background of the parents. The sample of the study consists of 25 participants; they are learners of English as a foreign language (EFL) at the College of Education for Women/ University of Baghdad. The data are collected by using a discourse completion task (DCT) followed by a follow up interview. The researchers used a Google form shared via emails to get responses from the p