The nucleus paragigantocellularis (PGI) is located in the rostral ventrolateral medulla and has noticeable connections with some other brain nuclei, such as locus ceruleus, nucleus raphe magnus and periaqueductal gray. In rats it is 3 mm in rostrocaudal and 1 mm in mediolateral and 1 mm in the dorsolateral aspect. Anatomically and functionally, PGI has been divided into two subnuclei, retrofaci...

Background: Ferula gummosa Boiss. is a medicinal and economical plant belonging to Apiaceae family. It is a native herb of Iran and is in serious danger of extinction. Objective: Gamma irradiation is an environmental stress and can consider as a new tool to change the content of secondary metabolites in medicinal plants. The effect of gamma irradiation on phenolic content and radical sc...

background: jaw bone quality plays an essential role in treatment planning and prognosis of dental implants. regarding several available methods for bone density measurements, they are not routinely used before implant surgery due to hard accessibility. objective: an in vitro investigation of correlation between average gray scale in direct digital radiographs and hounsfield units in ct-scan pr...

Introduction: Cone-beam CT (CBCT) is an imaging system which offers three-dimensional (3D), multiplanar images and has many advantages over computed tomography (CT) including shorter acquisition times for the resolution desired in dentistry, lower radiation dose to the patient, reasonable price and higher spatial resolution but CBCT scanners are unable to display actual Hounsf...

The pollen of five diploid and two tetraploid guayule (Parthenium argentatum Gray) plants was cultured on nutrient media. It was observed that guayule pollen is released as tetrads of spores which will not ger­ minate on the media unless they are separated into individual pollen grains. For each plant, the results of the germination tests varied with the day and the time of day of the pollen co...

www.sciencemag.org SCIENCE VOL 326 13 NOVEMBER 2009 909 COVER The Interstellar Boundary Explorer (IBEX) spacecraft has returned the first global images of the interaction of our heliosphere with the local interstellar medium. IBEX observations show a ribbon of energetic neutral atoms (reds to greens), snaking between the positions of the two Voyager spacecraft (white dots). This ribbon marks th...