Our Current Understanding of Commensalism

2020 ◽  
Vol 51 (1) ◽  
pp. 167-189
Author(s):  
Kaitlyn A. Mathis ◽  
Judith L. Bronstein
Keyword(s):  
Species Interactions ◽  
The Other ◽  
Current Understanding ◽  
Single Type ◽  
Future Research ◽  
Ecological Processes ◽  
Present Evidence ◽  
Ecological Literature ◽  
Evolutionary Consequences ◽  
The Continuum

Commensalisms, interactions between two species in which one species benefits and the other experiences no net effect, are frequently mentioned in the ecological literature but are surprisingly little studied. Here we review and synthesize our limited understanding of commensalism. We then argue that commensalism is not a single type of interaction; rather, it is a suite of phenomena associated with distinct ecological processes and evolutionary consequences. For each form of commensalism we define, we present evidence for how, where, and why it occurs, including when it is evolutionarily persistent and when it is an occasional outcome of interactions that are usually mutualistic or antagonistic. We argue that commensalism should be of great interest in the study of species interactions due to its location at the center of the continuum between positive and negative outcomes. Finally, we offer a roadmap for future research.

scholarly journals Longevity and ageing: appraising the evolutionary consequences of growing old

2005 ◽  
Vol 361 (1465) ◽  
pp. 119-135 ◽  
Author(s):  
Michael B Bonsall
Keyword(s):  
Life History ◽  
Biological Diversity ◽  
Species Coexistence ◽  
Life History Strategies ◽  
Life History Trait ◽  
Future Research ◽  
Ecological Processes ◽  
Physiological Processes ◽  
Trade Offs ◽  
Evolutionary Consequences

Senescence or ageing is an increase in mortality and/or decline in fertility with increasing age. Evolutionary theories predict that ageing or longevity evolves in response to patterns of extrinsic mortality or intrinsic damage. If ageing is viewed as the outcome of the processes of behaviour, growth and reproduction then it should be possible to predict mortality rate. Recent developments have shown that it is now possible to integrate these ecological and physiological processes and predict the shape of mortality trajectories. By drawing on the key exciting developments in the cellular, physiological and ecological process of longevity the evolutionary consequences of ageing are reviewed. In presenting these ideas an evolutionary demographic framework is used to argue how trade-offs in life-history strategies are important in the maintenance of variation in longevity within and between species. Evolutionary processes associated with longevity have an important role in explaining levels of biological diversity and speciation. In particular, the effects of life-history trait trade-offs in maintaining and promoting species diversity are explored. Such trade-offs can alleviate the effects of intense competition between species and promote species coexistence and diversification. These results have important implications for understanding a number of core ecological processes such as how species are divided among niches, how closely related species co-occur and the rules by which species assemble into food-webs. Theoretical work reveals that the proximate physiological processes are as important as the ecological factors in explaining the variation in the evolution of longevity. Possible future research challenges integrating work on the evolution and mechanisms of growing old are briefly discussed.

C. The Continuous Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney
Keyword(s):  
Continuous Spectrum ◽  
Variable Stars ◽  
Velocity Fields ◽  
The Other ◽  
Line Spectrum ◽  
Direct Information ◽  
Thermodynamic Structure ◽  
Diagnostic Interpretation ◽  
Pulsating Variable Stars ◽  
The Continuum

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.

The Continuum of Conscientiousness: The Antagonistic Interests among Obsessive and Antisocial Personalities

2014 ◽  
Vol 45 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Steven C. Hertler
Keyword(s):  
Personality Disorder ◽  
Evolutionary Theory ◽  
Antisocial Personality Disorder ◽  
The Other ◽  
Antisocial Personality ◽  
Obsessive Compulsive ◽  
Demographic Differences ◽  
Other Hand ◽  
The Continuum

Abstract The five factor trait of conscientiousnessis a supertrait, denoting on one hand a pattern of excessive labor, rigidity, orderliness and compulsivity,and on the other hand a pattern of strict rectitude, scrupulosity, dutifulness and morality. In both respects the obsessive-compulsive personality is conscientious; indeed, it has been labeled a disorder of extreme conscientiousness (Widiger et al., 2009). Antisocial personality disorder, in the present paper, is described as occupying the opposite end of the conscientiousness continuum. The antisocial is impulsive rather than compulsive, illicit rather than licit, and furtive rather than forthright.After clinically comparing the obsessive and antisocial personalities, the present paper invokes evolutionary theory to explain their resultant behavioral, ideological, political and demographic differences.

On Commutation Properties of the Composition Relation of Convergent and Divergent Permutations (Part I)

2014 ◽  
Vol 58 (1) ◽  
pp. 13-22
Author(s):  
Roman Wituła ◽  
Edyta Hetmaniok ◽  
Damian Słota
Keyword(s):  
Finite Order ◽  
Convergent Series ◽  
The Other ◽  
Other Hand ◽  
The Family ◽  
Composition Relation ◽  
The Continuum

Abstract In the paper we present the selected properties of composition relation of the convergent and divergent permutations connected with commutation. We note that a permutation on ℕ is called the convergent permutation if for each convergent series ∑an of real terms, the p-rearranged series ∑ap(n) is also convergent. All the other permutations on ℕ are called the divergent permutations. We have proven, among others, that, for many permutations p on ℕ, the family of divergent permutations q on ℕ commuting with p possesses cardinality of the continuum. For example, the permutations p on ℕ having finite order possess this property. On the other hand, an example of a convergent permutation which commutes only with some convergent permutations is also presented.

scholarly journals Collective efficacy and disorder through the eyes of neighbourhood inhabitants and key informants

2021 ◽  
pp. 147737082110006
Author(s):  
Wim Hardyns ◽  
Thom Snaphaan ◽  
Sara Willems ◽  
Lieven J. R. Pauwels
Keyword(s):  
Convergent Validity ◽  
Social Trust ◽  
Survey Method ◽  
Future Research ◽  
Ecological Stability ◽  
Organizational Processes ◽  
Ecological Processes ◽  
Key Informants ◽  
Analysis Technique ◽  
Key Informant

This study examines the ecological reliability, convergent validity and ecological stability of neighbourhood (dis)organizational processes measured by means of two methods: inhabitant surveys and the so-called key informant analysis technique. Considering that ecological processes play a major role in many contemporary criminological theories and research, it is vital to take into account methodological challenges and to question the reliability, validity and stability of the measures reflecting these underlying processes. (Dis)organizational processes are predominantly measured by means of questionnaires surveying neighbourhood inhabitants. To yield ecologically reliable and valid measures this approach requires large numbers of respondents. In this study we analyse the relationships between ecological measures of neighbourhood processes based on surveys of inhabitants versus key informants. The findings suggest that key informants can provide reliable, valid and stable measures of (dis)organizational neighbourhood processes. Therefore, the key informant analysis technique is an essential complementary, or even substitutive, method in the measurement of neighbourhood processes; shared survey-method variance is eliminated and it is possible to survey fewer key informants than inhabitants to obtain reliable and valid information on social trust and disorder. Nevertheless, this method is not suitable for measuring all neighbourhood processes, such as informal social control. Therefore, outstanding challenges and avenues for future research are discussed as well.

scholarly journals Endocrine Disrupting Chemicals: Current Understanding, New Testing Strategies and Future Research Needs

2021 ◽  
Vol 22 (2) ◽  
pp. 933
Author(s):  
Maria E. Street ◽  
Karine Audouze ◽  
Juliette Legler ◽  
Hideko Sone ◽  
Paola Palanza
Keyword(s):  
Endocrine Disrupting Chemicals ◽  
Endocrine System ◽  
Current Understanding ◽  
Future Research ◽  
Developmental Origins ◽  
Research Needs ◽  
Important Class ◽  
Testing Strategies ◽  
Endocrine Disrupting ◽  
Health And Disease

Endocrine disrupting chemicals (EDCs) are exogenous chemicals which can disrupt any action of the endocrine system, and are an important class of substances which play a role in the Developmental Origins of Health and Disease (DOHaD) [...]

scholarly journals A minimal timescale for the continuum in 4U 1608-52 and Aql X-1

2021 ◽  
Vol 502 (1) ◽  
pp. L72-L78
Author(s):  
K Mohamed ◽  
E Sonbas ◽  
K S Dhuga ◽  
E Göğüş ◽  
A Tuncer ◽  
...  
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Power Spectra ◽  
Light Curves ◽  
State Transitions ◽  
Strong Positive Correlation ◽  
Present Evidence ◽  
X Ray ◽  
X Ray Binaries ◽  
The Continuum

ABSTRACT Similar to black hole X-ray binary transients, hysteresis-like state transitions are also seen in some neutron-star X-ray binaries. Using a method based on wavelets and light curves constructed from archival Rossi X-ray Timing Explorer observations, we extract a minimal timescale over the complete range of transitions for 4U 1608-52 during the 2002 and 2007 outbursts and the 1999 and 2000 outbursts for Aql X-1. We present evidence for a strong positive correlation between this minimal timescale and a similar timescale extracted from the corresponding power spectra of these sources.

Children With Intellectual Disability and Victimization: A Logistic Regression Analysis

2021 ◽  
pp. 107755952199417
Author(s):  
Katherine R. Brendli ◽  
Michael D. Broda ◽  
Ruth Brown
Keyword(s):  
Logistic Regression ◽  
Regression Analysis ◽  
Intellectual Disability ◽  
Logistic Regression Analysis ◽  
District Of Columbia ◽  
The Other ◽  
Future Research ◽  
Common Assumption ◽  
Research And Practice ◽  
Demographic Correlates

It is a common assumption that children with disabilities are more likely to experience victimization than their peers without disabilities. However, there is a paucity of robust research supporting this assumption in the current literature. In response to this need, we conducted a logistic regression analysis using a national dataset of responses from 26,572 parents/caregivers to children with and without disabilities across all 50 states, plus the District of Columbia. The purpose of our study was to acquire a greater understanding of the odds of victimization among children with and without intellectual disability (ID), while controlling for several child and parent/adult demographic correlates. Most notably, our study revealed that children with ID have 2.84 times greater odds of experiencing victimization than children without disabilities, after adjusting for the other predictors in the model. Implications for future research and practice are discussed.

scholarly journals A taxonomy of antonymy in Arabic: Egyptian and Saudi proverbs in comparison

2021 ◽  
Vol 7 (1) ◽  
pp. 200-222
Author(s):  
Hamada Hassanein ◽  
Mohammad Mahzari
Keyword(s):  
Main Clause ◽  
The Other ◽  
Subordinate Clause ◽  
Future Research ◽  
Case Marking ◽  
News Discourse ◽  
Discourse Functions ◽  
Syntactic Frames

Abstract This study has set out to identify, quantify, typify, and exemplify the discourse functions of canonical antonymy in Arabic paremiography by comparing two manually collected datasets from Egyptian and Saudi (Najdi) dialects. Building upon Jones’s (2002) most extensive and often-cited classification of the discourse functions of antonyms as they co-occur within syntactic frames in news discourse, the study has substantially revised this classification and developed a provisional and dynamic typology thereof. Two major textual functions are found to be quantitatively significant and qualitatively preponderant: ancillarity (wherein an A-pair of canonical antonyms project their antonymicity onto a more important B-pair) and coordination (wherein one antonym holds an inclusive or exhaustive relation to another antonym). Three new functions have been developed and added to the retrieved classification: subordination (wherein one antonym occurs in a subordinate clause while the other occurs in a main clause), case-marking (wherein two opposite cases are served by two antonyms), and replacement (wherein one antonym is substituted with another). Semicanonical and noncanonical guises of antonymy are left and recommended for future research.

Political Marriage Alliances at the Shi'i Court of Awadh

1983 ◽  
Vol 25 (4) ◽  
pp. 593-616 ◽  
Author(s):  
Michael H. Fisher
Keyword(s):  
Las Vegas ◽  
Mutual Recognition ◽  
Social Groups ◽  
The Other ◽  
Shared Identity ◽  
Wedding Ceremony ◽  
Eleanor Of Aquitaine ◽  
The Continuum

A marriage expresses a mutual recognition of some degree of shared identity. The wedding ceremony confirms these links and creates new ones, although to an extent variable with the culture and the specific case. The affinity can be between individuals acting for themselves, for families, or for larger social or national groups. At one extreme would be the temporary liason, stemming from personal whim or passion, between individuals who share little more than common acceptance of the culture which recognizes the form. A Las Vegas marriage followed by a quickie Mexican divorce, a Hindu Gāndharva marriage consummated without any ceremony, or a Shi'i mut 'ah (marriage of pleasure) of contractually stipulated length might typify this end of the continuum. At the other end would be the purely political marriage that links social groups, parties, or even nations together but which disregards the desires of the principals. Richard II's diplomatic marriage to Eleanor of Aquitaine, a Kulin Brahmin's ritual marriage with dozens of women, or Asaf al-Daula's apparently unconsummated marriage with Shams al-Nisā' Begum (discussed later) exemplifies this extreme. Between lie a diversity of forms within a variety of cultures.

Sign in / Sign up

Export Citation Format

Share Document