48 research outputs found

    Effect of Bilateral Mandibular Osteodistration on the Condylar Cartilage: An Experimental Study on Rabbits

    Get PDF
    Although various aspects of bone formation during distraction osteogenesis have been studied extensively, there are only limited experimental data concerning the influence of hyper-physiologic mandibular distraction rate on structural alterations in the temporomandibular joint (TMJ) condylar cartilage. The purpose of this study was to evaluate the effect of bilateral distraction osteogenesis of the mandibular body, at a hyper-physiologic rate and length, on the integrity of the condylar cartilage in rabbits. MATERIALS AND METHODS: Eighteen healthy adult male rabbits weighing 2 to 3 kg were assigned to 1 of 2 groups: the control group (n = 2 rabbits, 4 joints) or the study group (n = 16 rabbits, 32 joints) four rabbits (8 joints) in each subgroup according to the post-distraction period (1,2,3 or 4 weeks). In the control group, rabbits received sham surgery (Osteotomy without distraction) and then left to live for 4 weeks under the same condition of the study group then euthanized using intravenous overdose of pentobarbital sodium. In the study group, an extra oral custom-made distracter was employed to achieve bilateral mandibular hyper physiologic distraction (1.5 mm twice daily for 5 days) distraction. All animals were evaluated clinically and histomorphometrically and results analyzed by MINITABE 13.1 statistical package using ANOVA test. RESULTS: Animals underwent distraction showed obvious changes in condylar surface contour related to length of the follow up period, compared to the control; these changes seemed to be partly reversible. The most pronounced observation was the irregularities and resorption in the anterior part of the condylar cartilage and the subcondylar bone. Moreover, at the first two weeks, the area of resorption was invaded by large number of osteoclasts and chronic inflammatory cells which declined later in the 3rd and 4th weeks and replaced with osteoblastic activities. CONSLUSION: These experimental data showed that distraction rate of 3 mm per day may lead to degenerative or even early arthritic changes in the TMJ condylar cartilage in the 1st and 2nd post-distraction weeks. However, all condyles showed adaptive and remodeling sings in the following 3rd and 4th weeks

    Modelling semantic transparency

    Get PDF
    We present models of semantic transparency in which the perceived trans- parency of English noun–noun compounds, and of their constituent words, is pre- dicted on the basis of the expectedness of their semantic structure. We show that such compounds are perceived as more transparent when the first noun is more frequent, hence more expected, in the language generally; when the compound semantic rela- tion is more frequent, hence more expected, in association with the first noun; and when the second noun is more productive, hence more expected, as the second ele- ment of a noun–noun compound. Taken together, our models of compound and con- stituent transparency lead us to two conclusions. Firstly, although compound trans- parency is a function of the transparencies of the constituents, the two constituents differ in the nature of their contribution. Secondly, since all the significant predictors in our models of compound transparency are also known predictors of processing speed, perceived transparency may itself be a reflex of ease of processing

    Fighting Software Piracy: Which Governance Tools Matter in Africa?

    Full text link
    This article integrates previously missing components of government quality into the governance-piracy nexus in exploring governance mechanisms by which global obligations for the treatment of IPRs are effectively transmitted from international to the national level in the battle against piracy. It assesses the best governance tools in the fight against piracy and upholding of Intellectual Property Rights (IPRs). The instrumentality of IPR laws (treaties) in tackling piracy through good governance mechanisms is also examined. Findings demonstrate that: (1) while all governance tools under consideration significantly decrease the incidence of piracy, corruption-control is the most effective weapon; (2) but for voice and accountability, political stability and democracy, IPR laws (treaties) are instrumental in tackling piracy through government quality dynamics of rule of law, regulation quality, government effectiveness, corruption-control, and press freedom. Hence, the need for a policy approach most conducive to expanding development is to implement an integrated system of both IPRs and corollary good governance policies. Moreover, our findings support the relevance of good governance measures in developing countries wishing to complement their emerging IPR regimes

    Enforcing IPR Through Informal Institutions: The Possible Role of Religion in Fighting Software Piracy

    Full text link
    The existence of formal IPR laws can be considered a prerequisite for having efficient law enforcement but does not imply efficient enforcement in itself. A simple model is constructed to explain the interplay between the IPR law and human behavior within counterfeiting countries. It shows how a politically monitored IPR enforcement strategy is able to alter formal IPR laws or institutions but might not affect informal institutions, or human morals and behavior, to the same extent, hence barely affecting piracy situation. The model shows the essential role of informal institutions and its sanction mechanisms in the enforcement process. The main obstacle of IPR enforcement is that people are still not convinced that IPR violations are unethical. Religion can be considered an informal institution that might support or hinder formal laws issued with regards to IPR and hence influence de facto enforcement of laws, especially in countries with high piracy rate if a high adherence to religion is found. As the Religion-Loyalty Index (RLI) developed by this study shows, Muslim countries have the highest religiosity level among different religions. Consequently, an investigation of how Islamic jurisprudence views IPR piracy is conducted. As Islam generally prohibits IPR piracy, a set of policy recommendations based on new institutional perspective is presented that can effectively help in minimizing IPR piracy in developing countries in general and Muslim ones in specific
    corecore