scholarly journals Genetic polymorphism in leaf-cutting ants is phenotypically plastic

2007 ◽  
Vol 274 (1618) ◽  
pp. 1625-1630 ◽  
Author(s):  
William O.H Hughes ◽  
Jacobus J Boomsma
Keyword(s):  
Division Of Labour ◽  
Genetic Influence ◽  
Caste Determination ◽  
Adaptive Property ◽  
The Social ◽  
Before And After ◽  
Large Worker ◽  
Leaf Cutting ◽  
Response Thresholds ◽  
Worker Caste

Advanced societies owe their success to an efficient division of labour that, in some social insects, is based on specialized worker phenotypes. The system of caste determination in such species is therefore critical. Here, we examine in a leaf-cutting ant ( Acromyrmex echinatior ) how a recently discovered genetic influence on caste determination interacts with the social environment. By removing most of one phenotype (large workers; LW) from test colonies, we increased the stimulus for larvae to develop into this caste, while for control colonies we removed a representative sample of all workers so that the stimulus was unchanged. We established the relative tendencies of genotypes to develop into LW by genotyping workers before and after the manipulation. In the control colonies, genotypes were similarly represented in the large worker caste before and after worker removal. In the test colonies, however, this relationship was significantly weaker, demonstrating that the change in environmental stimuli had altered the caste propensity of at least some genotypes. The results indicate that the genetic influence on worker caste determination acts via genotypes differing in their response thresholds to environmental cues and can be conceptualized as a set of overlapping reaction norms. A plastic genetic influence on division of labour has thus evolved convergently in two distantly related polyandrous taxa, the leaf-cutting ants and the honeybees, suggesting that it may be a common, potentially adaptive, property of complex, genetically diverse societies.

scholarly journals Epigenetics in Social Insects: A New Direction for Understanding the Evolution of Castes

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Susan A. Weiner ◽  
Amy L. Toth
Keyword(s):  
Dna Methylation ◽  
Social Insects ◽  
Differential Methylation ◽  
Caste Determination ◽  
The Social ◽  
Worker Castes ◽  
Regulatory Flexibility ◽  
Worker Caste ◽  
Caste Differences ◽  
Epigenetic Research

Epigenetic modifications to DNA, such as DNA methylation, can expand a genome’s regulatory flexibility, and thus may contribute to the evolution of phenotypic plasticity. Recent work has demonstrated the importance of DNA methylation in alternative queen and worker “castes” in social insects, particularly honeybees. Social insects are an excellent system for addressing questions about epigenetics and evolution because: (1) they have dramatic caste polyphenisms that appear to be tied to differential methylation, (2) DNA methylation is widespread in various groups of social insects, and (3) there are intriguing connections between the social environment and DNA methylation in many species, from insects to mammals. In this article, we review research on honeybees, and, when available, other social insects, on DNA methylation and queen and worker caste differences. We outline a conceptual framework for the effects of methylation on caste determination in honeybees that may help guide studies of epigenetic regulation in other polyphenic taxa. Finally, we suggest future paths of study for social insect epigenetic research, including the importance of comparative studies of DNA methylation on a broader range of species, and highlight some key unanswered mechanistic questions about how DNA methylation affects gene regulation.

scholarly journals Worker caste determination in the army ant Eciton burchellii

2007 ◽  
Vol 3 (5) ◽  
pp. 513-516 ◽  
Author(s):  
Rodolfo Jaffé ◽  
Daniel J.C Kronauer ◽  
F Bernhard Kraus ◽  
Jacobus J Boomsma ◽  
Robin F.A Moritz
Keyword(s):  
Social Insects ◽  
Division Of Labour ◽  
Test System ◽  
Caste Differentiation ◽  
Caste Determination ◽  
Task Specialization ◽  
Army Ant ◽  
Genetic Components ◽  
Eciton Burchellii ◽  
Worker Caste

Elaborate division of labour has contributed significantly to the ecological success of social insects. Division of labour is achieved either by behavioural task specialization or by morphological specialization of colony members. In physical caste systems, the diet and rearing environment of developing larvae is known to determine the phenotype of adult individuals, but recent studies have shown that genetic components also contribute to the determination of worker caste. One of the most extreme cases of worker caste differentiation occurs in the army ant genus Eciton , where queens mate with many males and colonies are therefore composed of numerous full-sister subfamilies. This high intracolonial genetic diversity, in combination with the extreme caste polymorphism, provides an excellent test system for studying the extent to which caste determination is genetically controlled. Here we show that genetic effects contribute significantly to worker caste fate in Eciton burchellii . We conclude that the combination of polyandry and genetic variation for caste determination may have facilitated the evolution of worker caste diversity in some lineages of social insects.

Doing politics by other means: Abdelmalek Sayad and the political sociology of a collective intellectual

2020 ◽  
Vol 68 (5) ◽  
pp. 999-1014
Author(s):  
Amín Pérez
Keyword(s):  
International Organizations ◽  
Political Action ◽  
The Political ◽  
Host Society ◽  
Intellectual Work ◽  
Academic Fields ◽  
The Social ◽  
Social Fields ◽  
Before And After ◽  
The One

This article proposes a new understanding of the constraints and opportunities that lead intellectuals engaged in different political and social fields to create alternative modes of resistance to domination. The study of the Algerian sociologist Abdelmalek Sayad offers insights into the social conditions of this mode of committed scholarship. On the one hand, this article applies Sayad’s theory of immigration to his transnational intellectual engagements. It establishes how immigrants’ intellectual work are conditioned by their trajectories, both before and after leaving their country, and by the stages of emigration (from playing a role in the society of origin to becoming caught up in the reality of the host society). On the other hand, the article illuminates the constraints and the spaces of possible action intellectuals face while moving across national universes and disparate political and academic fields. Sayad’s marginal position within the academy constrained him to work for the French and Algerian governments and international organizations while he was simultaneously engaged with political dissidents, unionists, writers, and social movements. In tracking Sayad’s roles as an academic, expert and public sociologist, the article uncovers the conditions that grounded improbable alliances between those fields and produced new forms of critique and political action. The article concludes by drawing out some reflections that ‘collective intellectual’ engagements elicit to the sociology of intellectuals.

Neural response thresholds in the Nucleus Contour cochlear implant before and after stylet removal

2009 ◽  
Vol 129 (11) ◽  
pp. 1330-1336 ◽  
Author(s):  
Robinson Koji Tsuji ◽  
Maria Valéria Schmidt Goffi-Gomez ◽  
Cristina Ornelas Peralta ◽  
Mariana Cardoso Guedes ◽  
Ana Tereza Magalhães ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Neural Response ◽  
Before And After ◽  
Response Thresholds

Antecedents of growth-oriented entrepreneurship before and during the Greek economic crisis

2017 ◽  
Vol 24 (3) ◽  
pp. 528-544 ◽  
Author(s):  
Ioannis Giotopoulos ◽  
Alexandra Kontolaimou ◽  
Aggelos Tsakanikas
Keyword(s):  
Work Experience ◽  
Early Stage ◽  
New Ventures ◽  
High Growth ◽  
Content Type ◽  
Crisis Period ◽  
Individual Level ◽  
Level Data ◽  
The Social ◽  
Before And After

Purpose The purpose of this paper is to explore potential drivers of high-growth intentions of early-stage entrepreneurs in Greece before and after the onset of the financial crisis of 2008. Design/methodology/approach To this end, the authors use individual-level data retrieved from Global Entrepreneurship Monitor annual surveys (2003-2015). Findings The results show that high-growth intentions of Greek entrepreneurs are driven by different factors in the crisis compared to the non-crisis period. Male entrepreneurs and entrepreneurs with significant work experience seem to be more likely to be engaged in growth-oriented new ventures during the crisis period. The same appears to hold for entrepreneurs who are motivated by an opportunity and also perceive future business opportunities in adverse economic conditions. On the other hand, the educational level and the social contacts of founders with other entrepreneurs are found to drive ambitious Greek entrepreneurship in the years before the crisis, while they were insignificant after the crisis outbreak. Originality/value Based on the concept of ambitious entrepreneurship, this study contributes to the literature by investigating the determinants of entrepreneurial high-growth expectations in the Greek context emphasizing the crisis period in comparison to the pre-crisis years.

TRAFFIC ACCIDENTS INVOLVING CHILD PEDESTRIANS: A PROGRAM FOR THEIR PREVENTION

PEDIATRICS ◽  
1969 ◽  
Vol 44 (5) ◽  
pp. 838-847
Author(s):  
John H. Read
Keyword(s):  
Traffic Accidents ◽  
Climatic Conditions ◽  
Systematic Research ◽  
Injury Patterns ◽  
Traffic Pattern ◽  
Enforcement Policy ◽  
The Social ◽  
Before And After ◽  
Pedestrian Accidents ◽  
Australian City

The two papers that follow report the results of painstaking epidemiological work on pedestrian accidents involving children. Because these papers relate the age of the child to specific behavior patterns that result in accidents and to specific injury patterns that result from such accidents, they would appear to offer a sound empirical base for the development of a variety of countermeasures, whether such countermeasures are intended to reduce accidents or to limit the severity of the resulting injuries. Unfortunately, however, the ability to generalize such data is extremely limited. A given pattern of child-pedestrian behavior is the result of a highly complex set of variables: the social class and ethnicity of the child, the ecological characteristics of the neighborhood and the broader community, the characteristics of the traffic pattern and the types and density of the vehicles that make it up, the current enforcement policy, climatic conditions, road and highway characteristics, and a host of other conditions that combine and interact in various ways. Consequently, few localities are sufficiently similar to justify the application of data from one to another. The injury patterns described by Ryan, for example, are those produced by Australian vehicles on children walking, playing, and cycling in a specific Australian city. It seems quite unlikely that the injury patterns produced in an American urban environment would resemble those that Ryan reports. Indeed, data from another Australian city might show striking differences. For the same reasons, such data as Read presents cannot be used reliably as a before-and-after measure to assess the effectiveness of a specific countermeasure. Any significant changes in the data after the introduction of a countermeasure might well be attributable not to the countermeasure itself but to changes in traffic patterns, ecology, the weather, or other events which operated to reinforce or counteract the countermeasure in question. The overwhelming obstacle to systematic research in vehicular accidents and on the assessment of countermeasure effectiveness is the investigator's inability to control the numerous variables that affect both the incidence and the consequences of accidents. The present papers, despite their inherently interesting data, are seriously limited by this problem.

scholarly journals Evaluation of pain in outpatient diagnostic hysteroscopy with gas

2010 ◽  
Vol 8 (1) ◽  
pp. 24-28
Author(s):  
Daniela Barreto Fraguglia Quental Diniz ◽  
Daniella de Batista Depes ◽  
Ana Maria Gomes dos Santos ◽  
Simone Denise David ◽  
Salete Yatabe ◽  
...  
Keyword(s):  
Social Sciences ◽  
Carbon Dioxide ◽  
Vaginal Delivery ◽  
Carbon Dioxide Gas ◽  
Verbal Scale ◽  
Experienced Pain ◽  
The Social ◽  
Before And After ◽  
Study Power ◽  
Diagnostic Hysteroscopy

ABSTRACT Objective: To evaluate the intensity of pain reported by patients undergoing outpatient diagnostic hysteroscopy. Methods: Exam performed with a 5-mm lens hysteroscope, vaginal speculum, tenaculum and uterine distention with carbon dioxide gas. Before and after the examination, patients were interviewed to define, in a verbal scale from 0 to 10, pain values that they expected to feel and that they experienced after the end, and also if they would repeat it if indicated. Data were analyzed using Statistical Package for the Social Sciences 15.0, statistic significance was defined as p < 0.05 with a study power of 95%. Results: Fifty-eight patients were included with mean age of 50.9 years, with 32.8% at postmenopause and 6.9% nulliparous. Among those with previous deliveries, mean parity was 2.21 and at least one vaginal delivery had occurred in 63.8%. Only 24.1% of patients knew how the exam would be done, 62.1% needed an endometrial sample and the result was considered satisfactory in 89.7%. The means of expected and experienced pain were similar (6.0 versus 6.1), and 91.4% of women would repeat the hysteroscopy if necessary. The only factor associated with less pain after the exam was previous vaginal delivery, with a decrease of pain score from 7.1 to 5.5 (p = 0.03). Mean pain was significantly lower in those who agreed to repeat the exam (5.8 versus 9.4; p = 0.003). Conclusions: Outpatient diagnostic hysteroscopy with gas can be associated with moderate but tolerable discomfort and satisfactory results.

scholarly journals The (mis)uses of life histories. The linguistic turn, life histories and (women’s) life stories

1999 ◽  
Vol 5 (12) ◽  
pp. 133-151
Author(s):  
Claudia de Lima Costa
Keyword(s):  
Social Sciences ◽  
Life Histories ◽  
Life Stories ◽  
Personal Narratives ◽  
Cultural Scripts ◽  
Linguistic Turn ◽  
The Social ◽  
Before And After ◽  
Women's Lives

This paper retraces the debates on life-histories before and after the linguistic turn in the social sciences, and, more specifically, in the anthropological tradition. It stresses how poststructuralist feminist methodological, theoretical, and political appropriations of personal narratives represent a significant textual intervention in the gendered social-cultural scripts of women’s lives.

Before and after the Italian National Elections of 1976

1977 ◽  
Vol 12 (1) ◽  
pp. 60-87 ◽  
Author(s):  
Gianfranco Pasquino
Keyword(s):  
Popular Front ◽  
National Elections ◽  
Social Democrats ◽  
Absolute Majority ◽  
The Social ◽  
Before And After ◽  
International Pressures

THE ITALIAN ELECTIONS OF 20 JUNE 1976 HAVE BEEN COMPARED TO those of 18 April 1948. Nearly thirty years ago, the Italian electorate, under heavy international pressures, gave 48.5 per cent of the votes and an absolute majority of seats to the DC (Christian Democrats) desisively defeating the Socialist-Communist Popular Front which polled only 31.0 per cent of the votes as compared to their combined percentage of 39.7 per cent only two years earlier (though, in the meantime, the Social Democrats had split from the Socialists and carried with them 7 per cent of the electorate).

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