In this paper, we present some physical models that can describe the ascent of volcanic ash into the atmosphere during a volcanic eruption. We consider both sustained volcanic eruption columns and discrete volcanic thermal clouds. To test the modeling approach, we compare our predictions of the ascent rate of a model cloud with some observations of the ascent of the ash cloud during the April 1...

Pruritic urticarial papules and plaques of pregnancy (PUPPP)(also known as polymorphic eruption of pregnancy in Europe) is an intensely pruritic eruption that affects women during the third trimester of pregnancy. Treatment usually is aimed at symptom relief until delivery, as the eruption usually resolves rapidly in the postpartum period. We report the case of a 30-year-old woman who presented...

Abstract Introduction: Maxillary canines commonly have an ectopic eruption. This study aimed to assess the factors related to the ectopic maxillary permanent canines. Materials and Methods:This was a descriptive cross-sectional study of 1357 panoramic radiographs from patients 8 to 13 years old. The radiography was excluded if the patient had any developmental disease or if the panoramic im...

INTRODUCTION In this prospective longitudinal study, we compared the prevalence of mandibular second molar eruption difficulties in patients treated with appliances to maintain mandibular arch perimeter. Other independent variables (age, molar angulation, space-width ratio, treatment time, and sex) were tested for their value as predictors of eruption difficulty. METHODS Three hundred one pat...

Polar ice core records attest to a colossal volcanic eruption that took place ca. A.D. 1257 or 1258, most probably in the tropics. Estimates based on sulfate deposition in these records suggest that it yielded the largest volcanic sulfur release to the stratosphere of the past 7,000 y. Tree rings, medieval chronicles, and computational models corroborate the expected worldwide atmospheric and c...

[1] Starting soon after the 1997 eruption at Okmok volcano and continuing until the start of the 2008 eruption, magma accumulated in a storage zone centered ∼3.5 km beneath the caldera floor at a rate that varied with time. A Mogi‐type point pressure source or finite sphere with a radius of 1 km provides an adequate fit to the deformation field portrayed in time‐sequential interferometric synth...

On 2005 September 13 a filament eruption accompanied by a halo CME occurred in the most flare-productive active region NOAA 10808 in Solar Cycle 23. Using multi-wavelength observations before the filament eruption on Sep. 13th, we investigate the processes leading to the catastrophic eruption. We find that the filament slowly ascended at a speed of 0.1km s over two days before the eruption. Dur...

The purpose of this study was to elucidate a possible association between ectopic first molar eruption causing root resorption on the distal root of the primary maxillary second molar, and ectopic canine eruption causing root resorption on the permanent maxillary incisors. The subjects consisted of 30 patients, 22 females and eight males in the age range 8.3-15.0 years in whom root resorption o...

OBJECTIVE: To evaluate the influence of the initial vertical position of impacted maxillary incisor on spontaneous eruption frequency and its timing after surgical removal of the supernumerary tooth. Material And Methods: 44 patients with unilateral impaction of maxillary permanent central incisor with an average age of 10.5 years were studied for spontaneous eruption of impacted tooth. Orthopa...