BACKGROUND Age at onset of Huntington's disease (HD) is largely determined by the CAG trinucleotide repeat length in the HTT gene. Importantly, the CAG repeat undergoes tissue-specific somatic instability, prevalent in brain regions that are disease targets, suggesting a potential role for somatic CAG repeat instability in modifying HD pathogenesis. Thus, understanding underlying mechanisms of ...

Stochastic fluctuations affect the dynamics of biological systems. Typically, such noise causes perturbations that can permit genetic circuits to escape stable states, triggering, for example, phenotypic switching. In contrast, studies have shown that noise can surprisingly also generate new states, which exist solely in the presence of fluctuations. In those instances noise is supplied externa...

We study operator Lyapunov equations in which the innnitesimal generator is not necessarily stable; but it satisses a spectrum decomposition assumption and it has at most nitely many unstable eigenvalues. Under mild conditions; these have unique self-adjoint solutions. We give conditions under which the number of negative eigenvalues of this solution equals the number of unstable eigenvalues of...

background: developmental dysplasia of hip (ddh) is a common childhood disorder, and ultrasonography examination is routinely used for screening purposes. in this study, we aimed to evaluate a modified combined static and dynamic   ultrasound technique for the detection of ddh and to compare with the results of static and dynamic ultrasound techniques.       methods: in this cross-sectional stu...

bus systems are unstable without considering any control. thus, we are able to consider some control strategies to alleviate this problem. a holding control strategy is one commonly used real-time control strategy that can improve service quality. this paper develops a mathematical model for a holding control strategy. the objective of this model is to minimize the total cost related to passeng...

background : developmental dysplasia of the hip (ddh), formerly known as congenital dislocation of the hip (cdh) is a common congenital malformation which occurs worldwide with variable frequencies in respect to the race and geographic distribution.    objective: to determine the incidence of ddh, its predisposing factors and the diagnostic value of click for its detection.   methods : in a cro...

Since the establishment of the Islamic Republic of Iran, there have been three packages used in the state-controlled schools of the country, namely, Graded, Right Path to English, and Prospect/Vision series. These textbooks all include prefaces to indicate the general philosophy of language teaching and education, and how the agents (learners and teachers) have to play roles in the system. This...