308 research outputs found
On some expansions for the Euler Gamma function and the Riemann Zeta function
In the present paper we introduce some expansions, based on the falling
factorials, for the Euler Gamma function and the Riemann Zeta function. In the
proofs we use the Fa\'a di Bruno formula, Bell polynomials, potential
polynomials, Mittag-Leffler polynomials, derivative polynomials and special
numbers (Eulerian numbers and Stirling numbers of both kinds). We investigate
the rate of convergence of the series and give some numerical examples.Comment: Published articl
Two control laws for a spray system with time varying delay and dead band
International audienceTwo control laws, to control the liquid pressure of an agricultural spray boom are presented and compared. Characteristic for the process is a dead zone and a time varying delay. The first control law is rather intuitive and is based on direct dead zone compensation and a pole placement idea. The other control law originates from sliding mode control where the continuous part of the control contains some compensation dynamics, assuring stability. Both control laws are compared and tested in practice
INTRODUCTION TO CLIFFORD ANALYSIS OVER PSEUDO-EUCLIDEAN SPACE
An introduction is given to Clifford Analysis over pseudo-Euclidean space of arbitrary signature, called for short Ultrahyperbolic Clifford Analysis (UCA). UCA is regarded as a function theory of Clifford-valued functions, satisfying a first order partial differential equation involving a vector-valued differential operator, called a Dirac operator. The formulation of UCA presented here pays special attention to its geometrical setting. This permits to identify tensors which qualify as geometrically invariant Dirac operators and to take a position on the naturalness of contravariant and covariant versions of such a theory. In addition, a formal method is described to construct the general solution to the aforementioned equation in the context of covariant UCA
First Same-Sex Partner and the Internet
The present study examined the first episode of anal intercourse of young gay and bisexual men (YGBM) who were in the midst of their coming-out. Cross-sectional data regarding the first episode of anal intercourse were extracted from Outcomes, a longitudinal study on coming-out and sexual behavior of YGBM in the Netherlands. Overall, 45% of respondents reported unprotected anal intercourse (UAI) with their first same-sex partner. Rates of UAI did not significantly differ between meeting place (offline vs. online) and partner status (steady, regular or casual)
Yeast as a Model System to Study Tau Biology
Hyperphosphorylated and aggregated human protein tau constitutes a hallmark of a multitude of neurodegenerative diseases called tauopathies, exemplified by Alzheimer's disease. In spite of an enormous amount of research performed on tau biology, several crucial questions concerning the mechanisms of tau toxicity remain unanswered. In this paper we will highlight some of the processes involved in tau biology and pathology, focusing on tau phosphorylation and the interplay with oxidative stress. In addition, we will introduce the development of a human tau-expressing yeast model, and discuss some crucial results obtained in this model, highlighting its potential in the elucidation of cellular processes leading to tau toxicity
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