Distortion of certain Voronoi tesselations when one particle moves

1979 ◽  
Vol 16 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Luis-M. Cruz Orive
Keyword(s):  
Sex Ratio ◽  
Animal Species ◽  
Plant Competition ◽  
Voronoi Polygon ◽  
Voronoi Tesselations ◽  
Relevant Role ◽  
Moving Particle

Some properties of the Voronoi polygon associated with a moving particle in a regular tessellation are studied. In particular, the area of the variable polygon has played a relevant role in previous studies on plant competition, animal predation, adjustment of the sex ratio in bisexual populations and the gregarious behaviour of animal species.

Distortion of certain Voronoi tesselations when one particle moves

1979 ◽  
Vol 16 (01) ◽  
pp. 95-103
Author(s):  
Luis-M. Cruz Orive
Keyword(s):  
Sex Ratio ◽  
Animal Species ◽  
Plant Competition ◽  
Voronoi Polygon ◽  
Voronoi Tesselations ◽  
Relevant Role ◽  
Moving Particle

Some properties of the Voronoi polygon associated with a moving particle in a regular tessellation are studied. In particular, the area of the variable polygon has played a relevant role in previous studies on plant competition, animal predation, adjustment of the sex ratio in bisexual populations and the gregarious behaviour of animal species.

The effect of operational sex ratio on sex allocation and neonate phenotype in a viviparous lizard Eremias multiocellata

2012 ◽  
Vol 33 (3-4) ◽  
pp. 485-493 ◽  
Author(s):  
Xiao-Long Tang ◽  
Feng Yue ◽  
De-Jiu Zhang ◽  
Xue-Feng Yan ◽  
Ying Xin ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Sex Allocation ◽  
Animal Species ◽  
Field Experiments ◽  
Maternal Investment ◽  
Tail Length ◽  
Operational Sex Ratio ◽  
Sex Allocation Theory ◽  
Female Investment ◽  
Eremias Multiocellata

Maternal investment in the production of male versus female neonates was approximately equal in most animal species. However, sex allocation theory predicts that under certain conditions, selection may favor the females’ ability to adjust the sex ratio of their offspring, which females tend to use more for an investment of the rare sex. The mechanism of operational sex ratio (OSR) influence on sex allocation is still unclear, and recent studies conducted on lizards have reached conflicting conclusions. Here, we selected a viviparous lizard Eremias multiocellata to test whether pregnant females could adjust the sex ratio of their offspring in response to OSRs. Our results showed that mothers did not adjust the sex ratios or phenotypes of neonates in the laboratory and field-based experiments, except tail length. However, the OSRs subsequently affected growth in both mass and SVL of the offspring in laboratory experiments; whereas only the mass was affected in the semi-nature field experiments. Our results, thus, contradict the predictions of sex allocation theory and challenge the idea that female investment in the scarcity sex might serve as a mechanism which is used for adjusting the population sex ratio.

scholarly journals Significant competitive dominance in mid-latitude European plant communities

2016 ◽  
Author(s):  
José A Capitán ◽  
Sara Cuenda ◽  
Alejandro Ordóñez ◽  
David Alonso
Keyword(s):  
Large Scale ◽  
Species Coexistence ◽  
Plant Competition ◽  
Biotic Interactions ◽  
Plant Distribution ◽  
Distribution Data ◽  
Coexistence Theory ◽  
Relevant Role ◽  
Plausible Mechanism ◽  
Main Determinants

Understanding the main determinants of species coexistence across space and time is a central question in ecology. However, ecologists still know little about the scales and conditions at which biotic interactions matter and their interplay with the environment to structure species assemblages. Here we develop ecological theory to analyze plant distribution and trait data across Europe and find that plant height clustering is related to evapotranspiration and gross primary productivity. Our analysis suggests competitive dominance as a plausible mechanism underlying community assembly patterns over these continental scales. In particular, we find a clear signal of plant-to-plant competition in mid-latitude ecoregions, where conditions for growth (reflected in actual evapotranspiration rates and gross primary productivities) are optimal. Under severe conditions, either climate is too harsh and overrides the effect of competition or other interactions play a relevant role. Our approach bridges the gap between modern coexistence theory and large-scale species distribution data analysis.

Author response for "Perceptual rivalry across animal species"

2020 ◽  
Author(s):  
Olivia Carter ◽  
Bruno Swinderen ◽  
David Leopold ◽  
Shaun Collin ◽  
Alex Maier
Keyword(s):  
Animal Species ◽  
Author Response ◽  
Perceptual Rivalry

Anchoring Fibrils in Arterial Endothelium

1969 ◽  
Vol 27 ◽  
pp. 274-275
Author(s):  
A. Trillo
Keyword(s):  
Carotid Arteries ◽  
Animal Species ◽  
Cell Layer ◽  
Present Communication ◽  
Internal Elastic Lamina ◽  
Endothelial Cell Layer ◽  
Structural Details ◽  
Rats And Mice ◽  
Arterial Endothelium ◽  
Elastic Lamina

There are conflicting reports regarding some fine structural details of arteries from several animal species. Buck denied the existence of a sub-endothelial space, while Karrer and Keech described a space of variable width which separates the endothelium from the underlying internal elastic lamina in aortas of aging rats and mice respectively.The present communication deals with the ultrastrueture of the interface between the endothelial cell layer and the internal elastic lamina as observed in carotid arteries from rabbits of varying ages.

Ultrastructure and Drug Metabolism in the Developing Guinea Pig

1973 ◽  
Vol 31 ◽  
pp. 538-539
Author(s):  
W. Kuenzig ◽  
M. Boublik ◽  
J.J. Kamm ◽  
J.J. Burns
Keyword(s):  
Guinea Pig ◽  
Metabolic Activity ◽  
Animal Species ◽  
Adult Animal ◽  
Smooth Endoplasmic Reticulum ◽  
Fetal Life ◽  
Mixed Function Oxidase ◽  
Cytochrome P 450 ◽  
Microsomal Mixed Function Oxidase ◽  
Mixed Function Oxidase Activity

Unlike a variety of other animal species, such as the rabbit, mouse or rat, the guinea pig has a relatively long gestation period and is a more fully developed animal at birth. Kuenzig et al. reported that drug metabolic activity which increases very slowly during fetal life, increases rapidly after birth. Hepatocytes of a 3-day old neonate metabolize drugs and reduce cytochrome P-450 at a rate comparable to that observed in the adult animal. Moreover the administration of drugs like phenobarbital to pregnant guinea pigs increases the microsomal mixed function oxidase activity already in the fetus.Drug metabolic activity is, generally, localized within the smooth endoplasmic reticulum (SER) of the hepatocyte.

Further Studies on the Ultrastructure of Harderian Gland in Adult Rats

1974 ◽  
Vol 32 ◽  
pp. 288-289
Author(s):  
Alfredo Feria-Velasco ◽  
Guadalupe Tapia-Arizmendi
Keyword(s):  
Fine Structure ◽  
Domestic Fowl ◽  
Animal Species ◽  
Acinar Cells ◽  
Harderian Gland ◽  
Myoepithelial Cells ◽  
The Other ◽  
Albino Rats ◽  
Adult Rats ◽  
Cell Components

The fine structure of the Harderian gland has been described in some animal species (hamster, rabbit, mouse, domestic fowl and albino rats). There are only two reports in the literature dealing on the ultrastructure of rat Harderian gland in adult animals. In one of them the author describes the myoepithelial cells in methacrylate-embbeded tissue, and the other deals with the maturation of the acinar cells and the formation of the secretory droplets. The aim of the present work is to analize the relationships among the acinar cell components and to describe the two types of cells located at the perifery of the acini.

Effect of Heart Rate Variability on Defensive Reaction and Eating Disorder Symptomatology in Chocolate Cravers

2009 ◽  
Vol 23 (3) ◽  
pp. 95-103 ◽  
Author(s):  
Sonia Rodríguez-Ruiz ◽  
Elisabeth Ruiz-Padial ◽  
Nieves Vera ◽  
Carmen Fernández ◽  
Lourdes Anllo-Vento ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Eating Disorder ◽  
Eating Behavior ◽  
Rest Period ◽  
Food Craving ◽  
Defensive Reaction ◽  
Relevant Role ◽  
Eating Disorder Symptomatology ◽  
Uncontrolled Eating

The study examines the effect of heart rate variability (HRV) on the cardiac defence response (CDR) and eating disorder symptomatology in chocolate cravers. Female chocolate cravers (n = 36) and noncravers (n = 36) underwent a psychophysiological test to assess their HRV during a 5-min rest period, followed by three trials to explore the CDR, elicited by an intense white noise, during the viewing of chocolate, neutral, and unpleasant pictures. After the test, participants completed a questionnaire to measure eating disorder symptomatology. The HRV was inversely related to the magnitude of the CDR and to eating disorder symptomatology in chocolate cravers. In addition, the HRV was inversely related to the magnitude of the CDR when viewing unpleasant pictures but not to neutral or chocolate ones, across all participants. These findings support the idea that poor autonomic regulation, indexed by low HRV, plays a relevant role in food craving and uncontrolled eating behavior.

The Contribution of Pavlov's Typology of CNS Properties to Personality Research

1997 ◽  
Vol 2 (2) ◽  
pp. 125-138 ◽  
Author(s):  
Jan Strelau
Keyword(s):  
Soviet Union ◽  
Former Soviet Union ◽  
Animal Species ◽  
Special Significance ◽  
The West ◽  
Personality Dimensions ◽  
Personality Research ◽  
Personality Theories ◽  
Strength Of Excitation ◽  
Point Of Departure

This paper presents Pavlov's contribution to the development of biological-oriented personality theories. Taking a short description of Pavlov's typology of central nervous system (CNS) properties as a point of departure, it shows how, and to what extent, this typology influenced further research in the former Soviet Union as well as in the West. Of special significance for the development of biologically oriented personality dimensions was the conditioned reflex paradigm introduced by Pavlov for studying individual differences in dogs. This paradigm was used by Russian psychologists in research on types of nervous systems conducted in different animal species as well as for assessing temperament in children and adults. Also, personality psychologists in the West, such as Eysenck, Spence, and Gray, incorporated the CR paradigm into their theories. Among the basic properties of excitation and inhibition on which Pavlov's typology was based, strength of excitation and the basic indicator of this property, protective inhibition, gained the highest popularity in arousaloriented personality theories. Many studies have been conducted in which the Pavlovian constructs of CNS properties have been related to different personality dimensions. In current research the behavioral expressions of the Pavlovian constructs of strength of excitation, strength of inhibition, and mobility of nervous processes as measured by the Pavlovian Temperament Survey (PTS) have been related to over a dozen of personality dimensions, mostly referring to temperament.

Animals as Social Objects

2016 ◽  
Vol 21 (3) ◽  
pp. 206-217 ◽  
Author(s):  
Verónica Sevillano ◽  
Susan T. Fiske
Keyword(s):  
Social Perception ◽  
Animal Species ◽  
Social Groups ◽  
Social Responses ◽  
Content Model ◽  
Stereotype Content ◽  
Nonhuman Animals ◽  
Behavioral Tendencies ◽  
Similarities And Differences ◽  
Sphere Of Influence

Abstract. Nonhuman animals are typically excluded from the scope of social psychology. This article presents animals as social objects – targets of human social responses – overviewing the similarities and differences with human targets. The focus here is on perceiving animal species as social groups. Reflecting the two fundamental dimensions of humans’ social cognition – perceived warmth (benign or ill intent) and competence (high or low ability), proposed within the Stereotype Content Model ( Fiske, Cuddy, Glick, & Xu, 2002 ) – animal stereotypes are identified, together with associated prejudices and behavioral tendencies. In line with human intergroup threats, both realistic and symbolic threats associated with animals are reviewed. As a whole, animals appear to be social perception targets within the human sphere of influence and a valid topic for research.

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