Search results for "Mating"

On the resolution of the lek paradox.

2007

Directional female mate choice is expected to deplete additive genetic variation in male traits. This should preclude such trait-based choice from resulting in genetic benefits to offspring, and yet genetic benefits are the explanation for the choice. This evolutionary conundrum is known as the lek paradox. Newly proposed resolutions to this paradox aim to unravel mechanisms that contribute to the persistence of genetic variance in traits under directional female mate choice.

Transposons Tn916 and Tn925 can transfer from Enterococcus faecalis to Leuconostoc oenos

1996

The streptococcal transposons Tn916 and Tn925 were transferred to several strains of Leuconostoc (Ln.) oenos using the filter mating method. The insertion of both transposons into the chromosome occurred at different sites. Transconjugants of Ln. oenos carrying Tn916 could serve as donors in mating experiments with Lactococcus lactis LM2301. Further analysis of L. lactis LM2301 transconjugants showed that the insertion of the transposon Tn916 into the chromosome was site-specific. These studies establish a basis for the initiation of genetic studies in this Leuconostoc species since there are no efficient conjugal or transformation systems previously described for this microorganism.

Offspring performance is linked to parental identity and male breeding ornamentation in whitefish

2009

The ‘good genes’ hypothesis predicts that males advertise their quality with different sexual ornaments and that females are able to recognize the genetic quality of males by evaluating these characteristics. In the present study, we investigated the parental effects on offspring performance (feeding and swimming ability of newly-hatched larvae) and examined whether male ornamentation indicates offspring success in performance trials of whitefish (Coregonus lavaretus Linnaeus). Offspring first-feeding success had a strong paternal effect and it was also positively correlated with the size of male breeding tubercles, indicating that breeding ornamentation of males can function as an honest i…

Survival relative to new and ancestral host plants, phytoplasma infection, and genetic constitution in host races of a polyphagous insect disease vec…

2014

Dissemination of vectorborne diseases depends strongly on the vector's host range and the pathogen's reservoir range. Because vectors interact with pathogens, the direction and strength of a vector's host shift is vital for understanding epidemiology and is embedded in the framework of ecological specialization. This study investigates survival in host-race evolution of a polyphagous insect disease vector, Hyalesthes obsoletus, whether survival is related to the direction of the host shift (from field bindweed to stinging nettle), the interaction with plant-specific strains of obligate vectored pathogens/symbionts (stolbur phytoplasma), and whether survival is related to genetic differentia…

Genome structure reveals the diversity of mating mechanisms in Saccharomyces cerevisiae x Saccharomyces kudriavzevii hybrids, and the genomic instabi…

2020

Interspecific hybridization has played an important role in the evolution of eukaryotic organisms by favouring genetic interchange between divergent lineages to generate new phenotypic diversity involved in the adaptation to new environments. This way, hybridization between Saccharomyces species, involving the fusion between their metabolic capabilities, is a recurrent adaptive strategy in industrial environments. In the present study, whole-genome sequences of natural hybrids between Saccharomyces cerevisiae and Saccharomyces kudriavzevii were obtained to unveil the mechanisms involved in the origin and evolution of hybrids, as well as the ecological and geographic contexts in which sponta…

Impact of mobility restrictions on active aging; cross-sectional associations and longitudinal changes parallel to COVID-19 restrictions

2021

Background: Meaningful activities can be done in or around home, but opportunities for participation and active aging decrease when moving in smaller areas. Active aging refers to having an active approach to life in line with one's goals, ability and opportunities. In adults over 75 years with different baseline neighborhood mobility levels, we studied active aging scores two years prior to and amid COVID-19, when governments restricted mobility of residents to slow the COVID-19 outbreak. Methods: AGNES cohort data were collected in 2017-2018 and spring 2020. Individuals were queried about their will, ability, and opportunity, and extent of doing 17 activities, and subsequently, item, comp…

2020

Abstract Background and objectives More knowledge is needed of the effectiveness of complex interventions that aim to promote the wellbeing of older people. This study examines the effects of ‘participatory group-based care management’ conducted among community-dwelling older adults living alone in Central and Eastern Finland. The intervention aimed to promote wellbeing and quality of life (QoL) using a needs-based and participatory approach. Methods The study was carried out as a randomized control trial (intervention group n = 185, control group n = 207). In this article, baseline and 6-month follow-up surveys were used. QoL (WHOQOL-Bref instrument), loneliness (Revised UCLA Loneliness Sc…

Life-Space Mobility and Active Aging as Factors Underlying Quality of Life Among Older People Before and During COVID-19 Lockdown in Finland—A Longit…

2020

Abstract Background Social distancing, that is, avoiding places with other people and staying at home, was recommended to prevent viral transmission during the COVID-19 pandemic. Potentially, reduced out-of-home mobility and lower activity levels among older people may lower their quality of life (QOL). We studied cross-sectional and longitudinal associations of and changes in life-space mobility, active aging, and QOL during COVID-19 social distancing compared to 2 years before. Methods Altogether 809 community-living participants initially aged 75, 80, or 85 years of our active aging study (AGNES) conducted in 2017–2018 took part in the current AGNES-COVID-19 survey in May and June 2020. …

Dietary magnesium intake is inversely associated with mortality in adults at high cardiovascular disease risk

2013

The relation between dietary magnesium intake and cardiovascular disease (CVD) or mortality was evaluated in several prospective studies, but few of them have assessed the risk of all-cause mortality, which has never been evaluated in Mediterranean adults at high cardiovascular risk. The aim of this study was to assess the association between magnesium intake and CVD and mortality risk in a Mediterranean population at high cardiovascular risk with high averagemagnesium intake. The present study included 7216 men and women aged 55-80 y fromthe PREDIMED (Prevencíon con Dieta Mediterŕanea) study, a randomized clinical trial. Participants were assigned to 1 of 2 Mediterranean diets (supplemente…

Effects of comprehensive geriatric assessment-based individually targeted interventions on mobility of pre-frail and frail community-dwelling older p…

2014

Aim To assess the effects of comprehensive geriatric assessment (CGA)-based individually targeted interventions on the ability to walk 400 m in pre-frail or frail and non-frail community-dwelling older people. Methods A subgroups analysis of a population-based comparative study, the Geriatric Multidisciplinary Strategy for the Good Care of the Elderly (GeMS) was carried out in the city of Kuopio, Finland, from 2004 to 2007. This study was based on data from 2005 to 2007. The present analysis included 605 community-dwelling older adults aged ≥76 years (mean age 80.9, 70% women), 314 in the intervention and 291 in the control group. Frailty status was assessed in 2005. Mobility was assessed b…