Search results for "VARIATION"
showing 10 items of 2124 documents
AtPGAP1 functions as a GPI inositol-deacylase required for efficient transport of GPI-anchored proteins
2021
Abstract Glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) play an important role in a variety of plant biological processes including growth, stress response, morphogenesis, signaling, and cell wall biosynthesis. The GPI anchor contains a lipid-linked glycan backbone that is synthesized in the endoplasmic reticulum (ER) where it is subsequently transferred to the C-terminus of proteins containing a GPI signal peptide by a GPI transamidase. Once the GPI anchor is attached to the protein, the glycan and lipid moieties are remodeled. In mammals and yeast, this remodeling is required for GPI-APs to be included in Coat Protein II-coated vesicles for their ER export and subsequent t…
Paradox lost: variable colour-pattern geometry is associated with differences in movement in aposematic frogs
2014
Aposematic signal variation is a paradox: predators are better at learning and retaining the association between conspicuousness and unprofitability when signal variation is low. Movement patterns and variable colour patterns are linked in non-aposematic species: striped patterns generate illusions of altered speed and direction when moving linearly, affecting predators' tracking ability; blotched patterns benefit instead from unpredictable pauses and random movement. We tested whether the extensive colour-pattern variation in an aposematic frog is linked to movement, and found that individuals moving directionally and faster have more elongated patterns than individuals moving randomly and…
Investigating Müllerian mimicry: predator learning and variation in prey defences
2006
Inexperienced predators are assumed to select for similarity of warning signals in aposematic species (Mullerian mimicry) when learning to avoid them. Recent theoretical work predicts that if co-mimic species have unequal defences, predators attack them according to their average unpalatability and mimicry may not be beneficial for the better defended co-mimic. In this study, we tested in a laboratory environment whether a uniform warning signal is superior to a variable one in promoting predator learning, and simultaneously whether co-mimics are preyed upon according to their average unpalatability. There was an interaction of signal variation and unpalatability but inexperienced birds did…
Determinant factors in the expression of the pronominal subject in spoken Spanish of Valencia
2021
En el presente artículo se estudian los factores determinantes de la presencia del sujeto pronominal en el área metropolitana de Valencia (España). Analizamos fragmentos de habla de un corpus de 72 entrevistas pertenecientes al corpus PRESEVAL, adscrito al grupo PRESEEA. Los resultados muestran la baja tendencia a utilizar la forma expresa (21,8 %). La aparición del sujeto pronominal se ve favorecida por la persona gramatical, muy especialmente la primera del singular, y la clase semántica de los verbos, sobre todo aquellos que indican estados mentales y actividades. Las variables sociales no son especialmente relevantes, si bien el nivel sociocultural y la lengua utilizada (es una comunida…
Systematic screening for mutations in the human serotonin-2A (5-HT2A) receptor gene: Identification of two naturally occurring receptor variants and …
1996
A statistically significant association between a silent mutation (102T/C) in the serotonin-2A (5-HT2A) receptor gene and schizophrenia has recently been reported in a sample of Japanese patients and healthy controls. This finding suggests that genetic predisposition to schizophrenia may be affected by a functional 5-HT2A receptor variant that is in linkage disequilibrium with 102T/C. In the present study, we have sought to identify genetic variation in the 5-HT2A receptor gene by screening genomic DNA samples from 91 unrelated subjects comprising 45 patients with schizophrenia and 46 healthy controls by using single-strand conformation analysis. We have identified four nucleotide sequence …
Anxiety and Covert Changes of Attention Control
1986
Publisher Summary This chapter presents a research paradigm, which allows the study of covert attentional processes in threatening situations and explores their relationship to the subjective experience of anxiety. These processes mediate changes of attention control beyond awareness by influencing the selective organization of behavior. The contingent negative variation (CNV) is a surface-negative slow potential that arises in the interstimulus interval of a forewarned reaction time task, where a warning signal (S1) precedes an imperative stimulus (S2), to which an overt motor response is required. If the interstimulus interval is shorter than approximately 3 seconds, CNV appears as a cont…
ENTROPY SOLUTIONS IN THE STUDY OF ANTIPLANE SHEAR DEFORMATIONS FOR ELASTIC SOLIDS
2000
The concept of entropy solution was recently introduced in the study of Dirichlet problems for elliptic equations and extended for parabolic equations with nonlinear boundary conditions. The aim of this paper is to use the method of entropy solutions in the study of a new problem which arise in the theory of elasticity. More precisely, we consider here the infinitesimal antiplane shear deformation of a cylindrical elastic body subjected to given forces and in a frictional contact with a rigid foundation. The elastic constitutive law is physically nonlinear and the friction is described by a static law. We present a variational formulation of the model and prove the existence and the uniquen…
Regularity of the Inverse of a Sobolev Homeomorphism
2011
We give necessary and sufficient conditions for the inverse ofa Sobolev homeomorphism to be a Sobolev homeomorphism and conditions under which the inverse is of bounded variation.
Penalty Function Methods for the Numerical Solution of Nonlinear Obstacle Problems with Finite Elements
2008
A class of penalty function methods for the solution of nonlinear variational inequalities with obstacles ⩽ 0 fur alle v ⩾ ψ in the Sobolev space W1, p (ω) is studied. The (nonlinear) penalty equations are solved by finite element techniques; the order of convergence of this procedure which depends on the regularity of the solution as well as on the finite elements used is investigated. Eine Klasse von Penalty-Methoden zur Losung nichtlinearer Variationsungleichungen mit Hindernisnebenbedingungen ⩽ 0 fur alle v ⩾ ψ im Sobolev Raum W1, p (ω) wird untersucht. Die (nichtlinearen) Penalty-Gleichungen werden mit Hilfe der Finite Elemente Methode gelost; die Konvergenzordnung dieses Verfahrens, w…
APPROXIMATION OF BANACH SPACE VALUED NON-ABSOLUTELY INTEGRABLE FUNCTIONS BY STEP FUNCTIONS
2008
AbstractThe approximation of Banach space valued non-absolutely integrable functions by step functions is studied. It is proved that a Henstock integrable function can be approximated by a sequence of step functions in the Alexiewicz norm, while a Henstock–Kurzweil–Pettis and a Denjoy–Khintchine–Pettis integrable function can be only scalarly approximated in the Alexiewicz norm by a sequence of step functions. In case of Henstock–Kurzweil–Pettis and Denjoy–Khintchine–Pettis integrals the full approximation can be done if and only if the range of the integral is norm relatively compact.