Search results for "differential"
showing 10 items of 6566 documents
Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory
2011
The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$, the proton component of the sources should lead to excesses in the same regions at energies $E/Z$. We here report the lack of anisotropies in these directions at energies above $E_{th}/Z$ (for illustrative values of $Z=6,\ 13,\ 26$). If the anisotropies above $E_{th}$ are du…
On the arithmetic and geometry of binary Hamiltonian forms
2011
Given an indefinite binary quaternionic Hermitian form $f$ with coefficients in a maximal order of a definite quaternion algebra over $\mathbb Q$, we give a precise asymptotic equivalent to the number of nonequivalent representations, satisfying some congruence properties, of the rational integers with absolute value at most $s$ by $f$, as $s$ tends to $+\infty$. We compute the volumes of hyperbolic 5-manifolds constructed by quaternions using Eisenstein series. In the Appendix, V. Emery computes these volumes using Prasad's general formula. We use hyperbolic geometry in dimension 5 to describe the reduction theory of both definite and indefinite binary quaternionic Hermitian forms.
Epidemiology of eating disorders in Latin America: a systematic review and meta-analysis.
2016
Purpose of reviewEating disorders are currently not considered to be limited to Western culture. We systematically reviewed the existing literature on the prevalence of eating disorders in Latin America.Recent findingsOf 1583 records screened, 17 studies from Argentina, Brazil, Chile, Colombia, Mexico, and Venezuela were included in the analysis. Most studies reported point-prevalence rates and only three studies provided lifetime and 12-month prevalence rates. We found a mean point-prevalence rate of 0.1% for anorexia nervosa, 1.16% for bulimia nervosa, and 3.53% for binge-eating disorder (BED) in the general population. Heterogeneity for bulimia nervosa and BED was large. This meta-analys…
Using the Johnson-Neyman Procedure to Detect Item Bias in Personality Tests
2016
I present an alternative to a widely used item-bias analysis procedure known as the ANOVA method. The new method is based on the Johnson-Neyman procedure, which is a multiple regression-based technique with properties that can overcome the major weaknesses of the ANOVA method. I introduce the proposed procedure in a non-technical manner, provide an illustrative example, and suggest guidelines for empirical analysis that can be readily applied in personality research.
Is mental health literacy for depression associated with the intention toward preventive actions? A cross-sectional study among university students
2021
Objective Mental Health Literacy (MHL) might play an important role in preventing depression. This study assessed the MHL level for depression of university students and its association with intentions toward preventive actions against depression. Participants: University students (n = 315) were surveyed online. Methods: MHL level and group differences were analyzed using t-tests and one-way ANOVA. To investigate the relation between MHL and the intention for preventive actions against depression, correlation and regression analyses were performed. Results: The mean MHL level of the participants was reasonably high (42.65 of 75 points). MHL levels differed significantly between different gr…
The “central dot sign” in acute epiploic appendagitis
2018
Epiploic appendagitis is the acute inflammation and infarction of epiploic appendages, commonly secondary to torsion. It is a great mimicker as its clinical manifestation may be similar to appendicitis, diverticulitis, or colitis. Focal abdominal pain, tenderness, and mild pyrexia are clinical features of the condition [1]. Epiploic appendages are pedunculated adipose structures which extend from the serosal surface of the colon, along the free taenia and taenia omentalis. They are abundant in the caecum and sigmoid colon and absent in the rectum
Intestinal tuberculosis in a child living in a country with a low incidence of tuberculosis : a case report
2014
Background: Relatively common in adults, intestinal tuberculosis is considered rare in children and adolescents. The protean manifestations of intestinal tuberculosis mean that the diagnosis is often delayed (sometimes even for years), thus leading to increased mortality and unnecessary surgery. The main diagnostic dilemma is to differentiate intestinal tuberculosis and Crohn’s disease because a misdiagnosis can have dramatic consequences. Case presentation: A 13-year-old Caucasian, Italian female adolescent attended the Emergency Department complaining of abdominal pain, a fever of up to 38°C, night sweats, diarrhea with blood in stool, and a weight loss of about three kilograms over the p…
Abel transforms with low regularity with applications to X-ray tomography on spherically symmetric manifolds
2017
We study ray transforms on spherically symmetric manifolds with a piecewise $C^{1,1}$ metric. Assuming the Herglotz condition, the X-ray transform is injective on the space of $L^2$ functions on such manifolds. We also prove injectivity results for broken ray transforms (with and without periodicity) on such manifolds with a $C^{1,1}$ metric. To make these problems tractable in low regularity, we introduce and study a class of generalized Abel transforms and study their properties. This low regularity setting is relevant for geophysical applications.
A generalization of Françoise's algorithm for calculating higher order Melnikov functions
2002
Abstract In [J. Differential Equations 146 (2) (1998) 320–335], Francoise gives an algorithm for calculating the first nonvanishing Melnikov function Ml of a small polynomial perturbation of a Hamiltonian vector field and shows that Ml is given by an Abelian integral. This is done under the condition that vanishing of an Abelian integral of any polynomial form ω on the family of cycles implies that the form is algebraically relatively exact. We study here a simple example where Francoise's condition is not verified. We generalize Francoise's algorithm to this case and we show that Ml belongs to the C [ log t,t,1/t] module above the Abelian integrals. We also establish the linear differentia…
Development and Characterization of an Amorphous Solid Dispersion of Furosemide in the Form of a Sublingual Bioadhesive Film to Enhance Bioavailabili…
2017
Administered by an oral route, Furosemide (FUR), a diuretic used in several edematous states and hypertension, presents bioavailability problems, reported as a consequence of an erratic gastrointestinal absorption due to various existing polymorphic forms and low and pH-dependent solubility. A mucoadhesive sublingual fast-dissolving FUR based film has been developed and evaluated in order to optimize the bioavailability of FUR by increasing solubility and guaranteeing a good dissolution reproducibility. The Differential Scanning Calorimetry (DSC) analyses confirmed that the film prepared using the solvent casting method entrapped FUR in the amorphous state. As a solid dispersion, FUR increa…