The effect of anti-sense RNA on the expression of the bialaphos resistance (bar) gene which encodes phosphinothricin acetyl transferase (PAT), was analysed in tobacco. Transient expression studies revealed that an anti-bar RNA with sequence complementarity to the complete bar coding region, inhibits PAT synthesis. To quantify the phenomenon, SR1 tobacco cells were transformed twice to introduce...

A mathematic-geometric model was used to evaluate the variation of mandibular dental arch length with respect to the incisor inclination, but without modifying the intercanine width. In analytical terms, the equations of the curves representing the lower dental arch, before and after incisor inclination of 1 mm and of 1 degree, with controlled and uncontrolled tipping, were studied. The length ...

Crowding is one of the causes of class I malocclusion. The purpose of the present study was to examine the relationship between arch length, arch width and arch perimeter in crowded and non-crowded arches, as well as to made comparison of the right and left sides between them and to find out the contributing factor in lower arch crowding. The study groups consisted of 60 subjects aged 16 to 21 ...

BACKGROUND AND AIM: Tooth extraction as a part of orthodontic treatment plan to create space for leveling and aligning teeth or causing tooth movement leads to changes in arch width and length. The outcome of these changes is important for the clinicians and affects the treatment and retention plans. Despite some previous studies, data in this regard are still scarce and further investigation i...

PURPOSE The rehabilitation of the edentulous mandible is a challenge due to various limiting factors, of which the available vertical restorative space (AVRS) has been well understood in the literature. However, other anatomic variations such as arch form, arch size, and also the interforaminal distance (IFD) (due to the presence of mandibular nerve) are influential in the selection of size and...

BACKGROUND In the Plio-Pleistocene, the hominin foot evolved from a grasping appendage to a stiff, propulsive lever. Central to this transition was the development of the longitudinal arch, a structure that helps store elastic energy and stiffen the foot during bipedal locomotion. Direct evidence for arch evolution, however, has been somewhat elusive given the failure of soft-tissue to fossiliz...

The conventional lingual arch is a nonfunctional fixed space maintainer used in the mandibular arch to maintain arch length by the prevention of mesial movement of the permanent first molars. This study highlights a functional lingual arch with a hinge-type lockable dentulous component that incorporates molar tubes, with various advantages over the conventional lingual arch. How to cite this ...

In this paper the class of ARCH(∞) models is generalized to the nonstationary class of ARCH(∞) models with time-varying coefficients. For fixed time points, a stationary approximation is given leading to the notation “locally stationary ARCH(∞) process.” The asymptotic properties of weighted quasi-likelihood estimators of time-varying ARCH(p) processes (p < ∞) are studied, including asymptotic ...

Magnetic resonance imaging has become the gold standard for imaging the aortic arch with the ability to demonstrate not only the arterial branching pattern, but also the relationship of aorta and its branches to the trachea and bronchi. Examples of four major aortic arch types--left aortic arch, right aortic arch, double aortic arch and persistent fifth aortic--with most of their variations are...