Does grandparental care select for a longer lifespan in non-human mammals?

Author(s):  
Guillaume Péron ◽  
Christophe Bonenfant ◽  
Jean-François Lemaitre ◽  
Victor Ronget ◽  
Morgane Tidiere ◽  
...  

Abstract Several non-human mammalian species provide grandparental care but remain fertile until death, unlike our species. This might call into question the ‘grandmother hypothesis’ that the ability to provide grandparental care, associated with an increase in the cost of breeding with age, promote the early cessation of reproduction. Here, we analyse individual longevity records from non-human mammals to determine whether the few species with grandparental care also stand out among mammals in terms of age-specific survival patterns. Indeed, females of species with grandparental care lived on average 43% longer than males (range: 24–61%), compared with 12% in other polygynous species (95% quantile: −8 to 30%), because of low baseline mortality rates and delayed onset of actuarial senescence. We discuss this finding with respect to the ‘stopping early’ vs. ‘living longer’ debate. We review the role of the environmental context and of the decrease in offspring performance with maternal age (Lansing effect). We formalize the idea of a continuum of parental–grandparental allocation instead of a discrete switch to grandparental care only. Lastly, we suggest that the evolution of menopause has been driven by different forces in different species.

2021 ◽  
Author(s):  
Marta Callejas‐Díaz ◽  
M. Regina Chambel ◽  
Javier San‐Martín‐Lorén ◽  
Guillermo Gea‐Izquierdo ◽  
Luis Santos‐Del‐Blanco ◽  
...  

2007 ◽  
pp. 70-84 ◽  
Author(s):  
E. Demidova

This article analyzes definitions and the role of hostile takeovers at the Russian and European markets for corporate control. It develops the methodology of assessing the efficiency of anti-takeover defenses adapted to the conditions of the Russian market. The paper uses the cost-benefit analysis, where the costs and benefits of the pre-bid and post-bid defenses are compared.


2020 ◽  
Vol 27 (2) ◽  
pp. 107-112
Author(s):  
Huseyin BUYUKGOL ◽  
◽  
Fatma Aysen EREN ◽  

The productivity of land has been often discussed and deliberated by the academia and policymakers to understand agriculture, however, very few studies have focused on the agriculture worker productivity to analyze this sector. This study concentrates on the productivity of agricultural workers from across the states taking two-time points into consideration. The agriculture worker productivity needs to be dealt with seriously and on a time series basis so that the marginal productivity of worker can be ascertained but also the dependency of worker on agriculture gets revealed. There is still disguised unemployment in all the states and high level of labour migration, yet most of the states showed the dependency has gone down. Although a state like Madhya Pradesh is doing very well in terms of income earned but that is at the cost of increased worker power in agriculture as a result of which, the productivity of worker has gone down. States like Mizoram, Meghalaya, Nagaland and Tripura, though small in size showed remarkable growth in productivity and all these states showed a positive trend in terms of worker shifting away from agriculture. The traditional states which gained the most from Green Revolution of the sixties are performing decently well, but they need to have the next major policy push so that they move to the next orbit of growth.


Author(s):  
Olga Osadtsia

The main forms and methods of distribution of music publications in Galicia in the XIX — early XX centuries are scrutinized. The demand for the relevant music production is one of the determining factors in the formation of the musical publishing repertoire, its structure and special features in the process of the existence of music publications in society. It is noted that export-import trade in books has become especially widespread in Galicia; there are facts about the links between publishers and booksellers in Lviv and Warsaw. The basic types of presentation of book advertising of music products, its regional peculiarities, and ways of its placement are considered. Special emphasis is placed on the role of specialized press in the advertising of music products, typical examples of press advertising. The registration bibliographic information as the initial form of music bibliography and the forms of its compilation are distinguished. The emphasis is placed on the importance of thorough critical articles as a separate typological group of bibliographic publications under the conditions of formation of the Ukrainian bibliography, in which the main importance is given to the disclosure of the content and evaluation of the reviewed work. The combination of article genres and reviews on examples of separate publications by Stanislav Lyudkevych and Ivan Franko is traced. Special book-selling and book-publishing catalogs are characterized. While executing the marketing and advertising function, these directories were addressed primarily to foreign consumers and distributors (the so-called commissioners).One way to distribute music is to subscribe through libraries. A significant financial factor in the distribution of any printed matter was the price that depended primarily on the cost of each process associated with its publication. Keywords: music publications, bookstore, book-trading enterprise, advertising of publications, pricing.


2021 ◽  
Vol 22 (11) ◽  
pp. 5918
Author(s):  
Paweł Kordowitzki ◽  
Gabriela Sokołowska ◽  
Marta Wasielak-Politowska ◽  
Agnieszka Skowronska ◽  
Mariusz T. Skowronski

The oocyte is the major determinant of embryo developmental competence in all mammalian species. Although fundamental advances have been generated in the field of reproductive medicine and assisted reproductive technologies in the past three decades, researchers and clinicians are still trying to elucidate molecular factors and pathways, which could be pivotal for the oocyte’s developmental competence. The cell-to-cell and cell-to-matrix communications are crucial not only for oocytes but also for multicellular organisms in general. This latter mentioned communication is among others possibly due to the Connexin and Pannexin families of large-pore forming channels. Pannexins belong to a protein group of ATP-release channels, therefore of high importance for the oocyte due to its requirements of high energy supply. An increasing body of studies on Pannexins provided evidence that these channels not only play a role during physiological processes of an oocyte but also during pathological circumstances which could lead to the development of diseases or infertility. Connexins are proteins that form membrane channels and gap-junctions, and more precisely, these proteins enable the exchange of some ions and molecules, and therefore they do play a fundamental role in the communication between the oocyte and accompanying cells. Herein, the role of Pannexins and Connexins for the processes of oogenesis, folliculogenesis, oocyte maturation and fertilization will be discussed and, at the end of this review, Pannexin and Connexin related pathologies and their impact on the developmental competence of oocytes will be provided.


2021 ◽  
pp. 135910532110299
Author(s):  
Terise Broodryk ◽  
Kealagh Robinson

Although anxiety and worry can motivate engagement with COVID-19 preventative behaviours, people may cognitively reframe these unpleasant emotions, restoring wellbeing at the cost of public health behaviours. New Zealand young adults ( n = 278) experiencing nationwide COVID-19 lockdown reported their worry, anxiety, reappraisal and lockdown compliance. Despite high knowledge of lockdown policies, 92.5% of participants reported one or more policy breaches ( M  = 2.74, SD = 1.86). Counter to predictions, no relationships were found between anxiety or worry with reappraisal or lockdown breaches. Findings highlight the importance of targeting young adults in promoting lockdown compliance and offer further insight into the role of emotion during a pandemic.


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