scholarly journals Sex-biased parasitism and expression of a sexual signal

2020 ◽  
Vol 131 (4) ◽  
pp. 785-800
Author(s):  
Adam A Rosso ◽  
Daniel J Nicholson ◽  
Michael L Logan ◽  
Albert K Chung ◽  
John David Curlis ◽  
...  
Keyword(s):  
Attachment Site ◽  
Cost Of Reproduction ◽  
Good Genes ◽  
Sexual Signals ◽  
Sexual Signal ◽  
Trade Offs ◽  
Parasite Infections ◽  
Handicap Hypothesis ◽  
Fat Bodies ◽  
The Relationship

Abstract Given that sexual signals are often expressed more highly in one sex than the other, they can impose a sex-specific cost of reproduction through parasitism. The two primary paradigms regarding the relationship of parasites to sexual signals are the good genes hypothesis and the immunocompetence handicap hypothesis; however, there are other ecological, morphological and energetic factors that might influence parasite infections in a sex-specific fashion. We tested the relationship between expression of a sexual signal (the dewlap) and ecological, morphological and energetic factors mediating ectoparasite (mite) load between male and female Panamanian slender anoles (Anolis apletophallus). We found that males were more highly parasitized than females because of the preponderance of ectoparasites on the larger dewlap of males. Indeed, ectoparasite infection increased with both body size and dewlap size in males but not in females, and parasite infection was related to energy storage in a sex-specific fashion for the fat bodies, liver and gonads. Our work and previous work on testosterone in anoles suggests that this pattern did not arise solely from immunosuppression by testosterone, but that mites prefer the dewlap as an attachment site. Thus, the expression of this sexual signal could incur a fitness cost that might structure life-history trade-offs.

scholarly journals Adiposity, compared with masculinity, serves as a more valid cue to immunocompetence in human mate choice

2013 ◽  
Vol 280 (1751) ◽  
pp. 20122495 ◽  
Author(s):  
Markus J. Rantala ◽  
Vinet Coetzee ◽  
Fhionna R. Moore ◽  
Ilona Skrinda ◽  
Sanita Kecko ◽  
...  
Keyword(s):  
Mate Choice ◽  
Female Mate Choice ◽  
Good Genes ◽  
Secondary Sexual Traits ◽  
Genetic Quality ◽  
Secondary Sexual Trait ◽  
Sexual Traits ◽  
Handicap Hypothesis ◽  
The Relationship ◽  
Secondary Sexual

According to the ‘good genes’ hypothesis, females choose males based on traits that indicate the male's genetic quality in terms of disease resistance. The ‘immunocompetence handicap hypothesis’ proposed that secondary sexual traits serve as indicators of male genetic quality, because they indicate that males can contend with the immunosuppressive effects of testosterone. Masculinity is commonly assumed to serve as such a secondary sexual trait. Yet, women do not consistently prefer masculine looking men, nor is masculinity consistently related to health across studies. Here, we show that adiposity, but not masculinity, significantly mediates the relationship between a direct measure of immune response (hepatitis B antibody response) and attractiveness for both body and facial measurements. In addition, we show that circulating testosterone is more closely associated with adiposity than masculinity. These findings indicate that adiposity, compared with masculinity, serves as a more important cue to immunocompetence in female mate choice.

scholarly journals Testosterone-mediated trade-offs in the old age: a new approach to the immunocompetence handicap and carotenoid-based sexual signalling

2009 ◽  
Vol 276 (1664) ◽  
pp. 2093-2101 ◽  
Author(s):  
C. Alonso-Alvarez ◽  
Lorenzo Pérez-Rodríguez ◽  
Jesus T. Garcia ◽  
Javier Viñuela
Keyword(s):  
Antioxidant Properties ◽  
Optimal Solution ◽  
Cell Mediated Immunity ◽  
Sexual Signals ◽  
Middle Aged ◽  
New Approach ◽  
Trade Off ◽  
Trade Offs ◽  
Sexual Signalling ◽  
Handicap Hypothesis

The immunocompetence handicap hypothesis proposes that testosterone mediates a trade-off between sexual signalling and immunocompetence in males. Such a trade-off could favour the reliability of sexual signals on the basis that testosterone required for signal expression also promotes immunosuppression. However, the immunosuppressive activity of testosterone has not been convincingly demonstrated. We propose that the optimal solution to the testosterone-mediated trade-off should change with age, explaining ambiguous results in the past. Testosterone and ageing would promote two simultaneous immunosuppressive challenges unaffordable for low-quality males. Oxidative stress, as intimately related to ageing and immunosenescence, could contribute to enhance signal reliability. In this context, traits coloured by carotenoids (yellow–red traits) could play a crucial role due to the immunostimulatory and antioxidant properties of these pigments. Here, old and middle-aged male red-legged partridges were treated with testosterone or manipulated as controls. In the presence of high-testosterone levels, middle-aged males increased both circulating carotenoid levels and colour expression, whereas their cell-mediated immunity was not significantly altered. However, in old males, neither circulating carotenoids nor sexual signalling increased when treated with testosterone, but immunosuppression was detected. The link between testosterone and carotenoids could favour the reliability of sexual signals throughout the life.

scholarly journals Elaborate visual and acoustic signals evolve independently in a large, phenotypically diverse radiation of songbirds

2014 ◽  
Vol 281 (1788) ◽  
pp. 20140967 ◽  
Author(s):  
Nicholas A. Mason ◽  
Allison J. Shultz ◽  
Kevin J. Burns
Keyword(s):  
Comparative Study ◽  
Evolutionary Biology ◽  
Inverse Correlation ◽  
Acoustic Signals ◽  
Sexual Signals ◽  
Sexual Signal ◽  
Trade Off ◽  
Selective Pressures ◽  
Sexual Signalling ◽  
The Relationship

The concept of a macroevolutionary trade-off among sexual signals has a storied history in evolutionary biology. Theory predicts that if multiple sexual signals are costly for males to produce or maintain and females prefer a single, sexually selected trait, then an inverse correlation between sexual signal elaborations is expected among species. However, empirical evidence for what has been termed the ‘transfer hypothesis’ is mixed, which may reflect different selective pressures among lineages, evolutionary covariates or methodological differences among studies. Here, we examine interspecific correlations between song and plumage elaboration in a phenotypically diverse, widespread radiation of songbirds, the tanagers. The tanagers (Thraupidae) are the largest family of songbirds, representing nearly 10% of all songbirds. We assess variation in song and plumage elaboration across 301 species, representing the largest scale comparative study of multimodal sexual signalling to date. We consider whether evolutionary covariates, including habitat, structural and carotenoid-based coloration, and subfamily groupings influence the relationship between song and plumage elaboration. We find that song and plumage elaboration are uncorrelated when considering all tanagers, although the relationship between song and plumage complexity varies among subfamilies. Taken together, we find that elaborate visual and vocal sexual signals evolve independently among tanagers.

STUDY ON THE RELATIONSHIP BETWEEN PARASITIC INFECTION AND KNOWLEDGE, HYGIENIC PRACTICAL MEASURES OF PARASITIC INFECTIOUS PREVENTION IN VINH THAI COMMUNITY

2017 ◽  
pp. 119-124
Author(s):  
Keyword(s):  
Health Education ◽  
Risk Behaviors ◽  
Ascaris Lumbricoides ◽  
Intestinal Parasite ◽  
Parasitic Infection ◽  
Parasite Infection ◽  
Intestinal Parasite Infection ◽  
Before And After ◽  
Parasite Infections ◽  
The Relationship

Introduction: Intestinal parasite infections werecommonintropical country such as Vietnam. Having good knowledge of parasitic infectious prevention and changing risk behaviors can decrease the infection rate. Objective: To evaluate the parasitic infectious rate in Vinh Thai community before and after being health education and the changing of knowledge of parasitic infectious prevention and risk behaviors. Materials and methods: 60 households in Vinh Thai commune were interviewed their knowledge of parasitic infectious prevention and examined intestinal parasite infection by Kato technique and then trained the knowledge of parasitic infectious prevention. The interview and examination parasite infectiousrate were carried out after 6 months to evaluating their knowledge. Result: Before health education, the rate of intestinal parasite infection was 17.4% with the prevalence of Ascaris lumbricoides, hookworm, whipworm, pinworm, small fluke worm and co-infection with A. lumbricoides - whipworm, hookworm-whipworm were 0.1%; 8.0%; 5.8%; 0.6%; 0.3%; 1.2% and 3.0% respectively. Six months later the rate of intestinal parasite infection was decreased in 12.6% even though not statistical significantly. However, there were no case of small fluke worm and co-infection with hookworm-whipworm. Receiving health education, their knowledge of parasitic infectious prevention was higher significantly but their risk behaviors were not changed so much. Conclusion: Health education can change the rate of parasite infection with higher knowledge of parasitic infectious prevention but it was necessary continuous study to change the risk behaviors. Key words: intestinal parasite, health education

scholarly journals Social and endocrine correlates of immune function in meerkats: implications for the immunocompetence handicap hypothesis

2018 ◽  
Vol 5 (8) ◽  
pp. 180435 ◽  
Author(s):  
Kendra N. Smyth ◽  
Nicholas M. Caruso ◽  
Charli S. Davies ◽  
Tim H. Clutton-Brock ◽  
Christine M. Drea
Keyword(s):  
Immune Function ◽  
Social Status ◽  
Dominant Species ◽  
Reproductive Activity ◽  
Trade Offs ◽  
Endocrine Mechanism ◽  
Immunocompetence Handicap Hypothesis ◽  
Handicap Hypothesis ◽  
Serum Bacteria ◽  
Bacteria Killing

Social status can mediate effects on the immune system, with profound consequences for individual health; nevertheless, most investigators of status-related disparities in free-ranging animals have used faecal parasite burdens to proxy immune function in the males of male-dominant species. We instead use direct measures of innate immune function (complement and natural antibodies) to examine status-related immunocompetence in both sexes of a female-dominant species. The meerkat is a unique model for such a study because it is a cooperatively breeding species in which status-related differences are extreme, evident in reproductive skew, morphology, behaviour, communication and physiology, including that dominant females naturally express the greatest total androgen (androstenedione plus testosterone) concentrations. We found that, relative to subordinates, dominant animals had reduced serum bacteria-killing abilities; also, relative to subordinate females, dominant females had reduced haemolytic complement activities. Irrespective of an individual's sex or social status, androstenedione concentrations (but not body condition, age or reproductive activity) negatively predicted concurrent immunocompetence. Thus, dominant meerkats of both sexes are immunocompromised. Moreover, in female meerkats, androstenedione perhaps acting directly or via local conversion, may exert a double-edged effect of promoting dominance and reproductive success at the cost of increased parasitism and reduced immune function. Given the prominent signalling of dominance in female meerkats, these findings may relate to the immunocompetence handicap hypothesis (ICHH); however, our data would suggest that the endocrine mechanism underlying the ICHH need not be mediated solely by testosterone and might explain trade-offs in females, as well as in males.

Chinese "Cancer Villages"

2020 ◽  
Author(s):  
Ajiang Chen ◽  
Pengli Cheng ◽  
Yajuan Luo
Keyword(s):  
Public Health ◽  
Economic Growth ◽  
Cultural Change ◽  
Social Life ◽  
Social Economic ◽  
Rural China ◽  
Sociological Analysis ◽  
Complex Interactions ◽  
Trade Offs ◽  
The Relationship

The phenomenon of "cancer villages" has emerged in many parts of rural China, drawing media attention and becoming a fact of social life. However, the relationship between pollution and disease is often hard to discern. Through sociological analysis of several villages with different social and economic structures, the authors offer a comprehensive, historically grounded analysis of the coexistence between the incidence of cancer, environmental pollution and villagers’ lifestyles, as well as the perceptions, claims and responses of different actors. They situate the appearance of "cancer villages" in the context of social, economic and cultural change in China, tracing the evolution of the issue over two decades, and providing deep insights into the complex interactions and trade-offs between economic growth, environmental change and public health.

scholarly journals Research on Mediating Mechanisms and the Impact on Food Provision Services in Poor Areas from the Perspective of Stakeholders

2021 ◽  
Vol 18 (19) ◽  
pp. 10510
Author(s):  
Tianwei Geng ◽  
Hai Chen ◽  
Di Liu ◽  
Qinqin Shi ◽  
Hang Zhang
Keyword(s):  
Ecosystem Service ◽  
Behavioral Responses ◽  
The Loess Plateau ◽  
Trade Offs ◽  
Different Types ◽  
Mediating Mechanisms ◽  
The Common ◽  
Food Provision ◽  
The Impact ◽  
The Relationship

Exploring and analyzing the common demands and behavioral responses of different stakeholders is important for revealing the mediating mechanisms of ecosystem service (ES) and realizing the management and sustainable supply of ES. This study took Mizhi County, a poverty-stricken area on the Loess Plateau in China, as an example. First, the main stakeholders, common demands, and behavioral responses in the food provision services were identified. Second, the relationship among stakeholders was analyzed. Finally, this study summarized three types of mediating mechanisms of food provision services and analyzed the influence of the different types of mediating mechanisms. The main conclusions are as follows: (1) Five main stakeholders in the study area were identified: government, farmers, enterprises, cooperatives, and middlemen. (2) Increasing farmers’ income is the common demand of most stakeholders in the study area, and this common demand has different effects on the behavioral responses of different stakeholders. (3) There are three types of mediating mechanisms in the study area: government + farmers mediating corn and mutton, government + enterprises mediating millet, and government + cooperatives mediating apples. On this basis, the effects of the different types of mediating mechanisms on variations in food yield, and trade-offs and synergies in typical townships, were analyzed.

scholarly journals Effects of Bacterial Cell-Free Supernatant on Nutritional Parameters of Apis Mellifera and Their Toxicity Against Varroa Destructor

2020 ◽  
Vol 64 (1) ◽  
pp. 55-66
Author(s):  
Fiorella G. De Piano ◽  
Matias D. Maggi ◽  
Facundo R. Meroi Arceitto ◽  
Marcela C. Audisio ◽  
Martín Eguaras ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Varroa Destructor ◽  
High Concentration ◽  
Colony Losses ◽  
Nutritional Parameters ◽  
Low Concentrations ◽  
Bee Health ◽  
Contact Exposure ◽  
Fat Bodies ◽  
The Relationship

AbstractApis mellifera L. is an essential pollinator that is currently being affected by several stressors that disturb their ecological function and produce colony losses. Colonies are being seriously affected by the ectoparasitic mite Varroa destructor. The relationship between stressors and bee symbionts is being studied in order to enhance bee health. The goal of this study was to evaluate the effect of cell-free supernatants (CFSs) produced by Lactobacillus johnsonii AJ5, Enterococcus faecium SM21 and Bacillus subtilis subsp. subtilis Mori2 on A. mellifera nutritional parameters and their toxicity against V. destructor. Toxicity and survival bioassays were conducted on adult bees with different concentrations of CFSs. Nutritional parameters such as soluble proteins and fat bodies in abdomens were measured. Varroa destructor toxicity was analyzed by a contact exposure method and via bee hemolymph. At low concentrations, two of CFSs tends to enhance bee survival. Remarkably fat bodies maintained their levels with all CFS concentrations in the abdomens, and soluble protein increased at a high concentration of two CFSs. Toxicity against V. destructor was observed only via hemolymph, and results were in agreement with the treatment that produced an increase in bee proteins. Finally, CFS produced by L. johnsonii AJ5 could be a promising natural alternative for strengthening bee health.

scholarly journals Security-Efficiency Tradeoffs in Searchable Encryption

2019 ◽  
Vol 2019 (4) ◽  
pp. 132-151 ◽  
Author(s):  
Raphael Bost ◽  
Pierre-Alain Fouque
Keyword(s):  
Lower Bounds ◽  
Minimum Cost ◽  
Searchable Encryption ◽  
Search Queries ◽  
Trade Offs ◽  
Encryption Schemes ◽  
Security Properties ◽  
Client State ◽  
The Relationship

Abstract Besides their security, the efficiency of searchable encryption schemes is a major criteria when it comes to their adoption: in order to replace an unencrypted database by a more secure construction, it must scale to the systems which rely on it. Unfortunately, the relationship between the efficiency and the security of searchable encryption has not been widely studied, and the minimum cost of some crucial security properties is still unclear. In this paper, we present new lower bounds on the trade-offs between the size of the client state, the efficiency and the security for searchable encryption schemes. These lower bounds target two kinds of schemes: schemes hiding the repetition of search queries, and forward-private dynamic schemes, for which updates are oblivious. We also show that these lower bounds are tight, by either constructing schemes matching them, or by showing that even a small increase in the amount of leaked information allows for constructing schemes breaking the lower bounds.

scholarly journals Value-based provider payment: towards a theoretically preferred design

2018 ◽  
Vol 15 (1) ◽  
pp. 94-112 ◽  
Author(s):  
Daniëlle Cattel ◽  
Frank Eijkenaar ◽  
Frederik T. Schut
Keyword(s):  
Health Care ◽  
Pay For Performance ◽  
Empirical Studies ◽  
Risk Profile ◽  
Provider Group ◽  
Payment Incentives ◽  
Trade Offs ◽  
Provider Payment ◽  
Group 2 ◽  
The Relationship

AbstractWorldwide, policymakers and purchasers are exploring innovative provider payment strategies promoting value in health care, known as value-based payments (VBP). What is meant by ‘value’, however, is often unclear and the relationship between value and the payment design is not explicated. This paper aims at: (1) identifying value dimensions that are ideally stimulated by VBP and (2) constructing a framework of a theoretically preferred VBP design. Based on a synthesis of both theoretical and empirical studies on payment incentives, we conclude that VBP should consist of two components: a relatively large base payment that implicitly stimulates value and a relatively small payment that explicitly rewards measurable aspects of value (pay-for-performance). Being the largest component, the base payment design is essential, but often neglected when it comes to VBP reform. We explain that this base payment ideally (1) is paid to a multidisciplinary provider group (2) for a cohesive set of care activities for a predefined population, (3) is fixed, (4) is adjusted for the population’s risk profile and (5) includes risk-mitigating measures. Finally, some important trade-offs in the practical operationalisation of VBP are discussed.

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