Determinants of healthy ageing: a systematic review of contemporary literature.

BACKGROUND: Healthy ageing frameworks have been highly explored. Our objective was to assess existing frameworks for healthy ageing and to identify commonly described factors that can potentially act as determinants of healthy ageing. METHODS: We carried out a systematic review by searching five electronic databases (EMBASE, MEDLINE, Cochrane, PsychINFO, and CINAHL) from January 2010 to November 2020 to capture contemporary evidence. Eligible studies needed to report a clear framework of healthy ageing in humans, within one or more of three domains (physical, mental/cognitive, social), in English. No restriction was placed on geographical location. Retrospective studies, studies that did not report a framework of healthy ageing, and studies with a focus on diagnostic measures were excluded. RESULTS: Of 3329 identified records, nine studies met our eligibility criteria and were included. Most of the studies were qualitative or cross sectional, and a majority were carried out in Asia, followed by North America, Australia, and Africa. The ten determinants identified for healthy ageing include physical activity, diet, self-awareness, outlook/attitude, life-long learning, faith, social support, financial security, community engagement, and independence. CONCLUSIONS: We identified ten determinants of healthy ageing proposed by the contemporary evidence base. There appears to be increasing acknowledgement of the instrumental role of social and mental/cognitive well-being as determinants of healthy ageing. The extent to which each determinant contributes to healthy ageing requires further evaluation.

Divergence in energy sources for Prochilodus lineatus (Characiformes: Prochilodontidae) in Neotropical floodplains

The stable carbon isotopic variability and the contributions of autochthonous (sediment microbial biomass, phytoplankton, and periphyton) and allochthonous (soil microbial biomass) sources available to the detritivorous fish Prochilodus lineatus were investigated in three environments of the floodplain of the Upper Paraná River. The isotopic composition of carbon sources and fish varied significantly among the studied environments. The autochthonous resources, represented by the phytoplankton, were the most assimilated by the species, followed by periphyton and sediment microbial biomass. The species used the sources differently in each environment. This study suggests that the inherent characteristics of this area, as well as the size of the watershed, the dry season, anthropogenic actions, and phytoplankton productivity, favor the use of autochthonous resources by the species studied. Therefore, studies in the floodplain should employ an eco-hydrological approach that quantifies the magnitude of energy subsidies, as well as an access route to consumers, knowledge about the selectivity of detritivorous species and the effects of different land uses.(AU)

A variabilidade isotópica e as contribuições autóctones (biomassa microbiana do sedimento, fitoplâncton e perifíton) e alóctone (biomassa microbiana do solo) assim como as principais fontes de carbono para o peixe detritívoro Prochilodus lineatus foram investigadas em três diferentes ambientes, da planície de inundação do alto rio Paraná. A composição isotópica das fontes de carbono e dos consumidores variaram significativamente entre os ambientes estudados, e os recursos alóctones, representados pelo fitoplâncton, foram os mais utilizados pela espécie, seguido pelo perifíton e biomassa do sedimento microbiano. A espécie utilizou fontes de carbono distintas em cada ambiente. Este estudo sugere que características inerentes a cada ambiente, assim como o tamanho do ambiente, o período de seca, ações antropogênicas e produtividade do fitoplâncton favorecem o uso dos recursos alóctones pela espécie estudada. Portanto, estudos na planície de inundação devem empregar uma abordagem eco-hidrológicas que quantifique a magnitude dos subsídios energéticos, bem como as vias energéticas aos consumidores, o conhecimento acerca da seletividade das espécies de detritívoros e o efeito dos diferentes usos da terra.(AU)

Use of food resuurces by detritivorous fish in floodplains: a syntheiis / El uso de los recursos alimenticios por peces detritívoros en planicies de inundación: una síntesis

The present review investigated the sources of energy for detritivorous fish species in floodplains. Recent studies have shown that environmental changes that alter the terrestrial vegetation affect essentially the resource base in these areas, such as the detritus. In aquatic environments, especially floodplains, a major part of metabolic processes is supported by terrestrial detritus, which accounts for maintaining the detritivorous food chain. Thus, one way to evaluate environments changes is through isotopic studies of organic matter, which allows acquiring information about the quantity and quality of organic matter. This approach is required for understanding the interactions between the organic matter dynamics and its ecological effects, allowing the monitoring of these resources. However, researches on the energy flow in food chains should also employ an approach that quantifies the magnitude of these food subsidies, as also the access routes of aquatic consumers, in watersheds of different sizes and in diverse land uses.

Esta revisión procuró investigar las fuentes de energía para las especies de peces detritívoras en la llanura de inundación. Los estudios han demostrado que las transformaciones ambientales que causan los cambios en la vegetación terrestre afectan principalmente la base de los recursos en estos planos inundables, tales como el detritus. En los ambientes acuáticos, especialmente las llanuras de inundación, la mayoría de los procesos metabólicos están sustentados por el detritus terrestre, y esta función es responsable de mantener las redes detritívoras. Una forma de evaluar estos cambios es a través de estudios isotópicos de la materia orgánica, los cuales permiten obtener información sobre su cantidad y su calidad mediante el análisis de la biomasa microbiana. Este enfoque es necesario para comprender las interacciones entre la dinámica de la materia orgánica y sus efectos ecológicos, lo que permite a su vez la valoración de estos recursos. Sin embargo, se concluye que los estudios futuros también deben cuantificar la magnitud de estos subsidios energéticos, asícomo las vías de acceso de los consumidores acuáticos, lo cual debe evaluarse en cuencas hidrográficas de diferentes tamaños y con diversos usos de la tierra.

Leaf allocation patterns and 13C and 15N natural abundances of tropical lianas (Passiflora sp.) as dependent on external climbing support.

The transformation from self-supporting lianas to host-supported climbing lianas is related to re-allocation of biomass and nutrients among plant organs. Therefore, first, variations in leaf mass per area (LMA), leaf carbon and nitrogen allocation and (13)C and (15)N natural abundances were analysed among three tropical Passiflora species (P. edulis, P. ligularis, and P. tripartita) in a greenhouse study. Second, the influence of a climbing support was considered for each species and parameter. P. ligularis leaves were most enriched in (13)C in both treatments when compared with the other two species. This enrichment was caused by a high LMA, which is related to a high internal resistance to CO(2) diffusion. For P. edulis and P. tripartita, δ(13)C was additionally increasing with nitrogen content per area. Generally, there were no differences when considering carbon and nitrogen allocation to leaves of host-supported and self-supporting lianas. The only hints towards increased investment into leaves after the transition from self-supporting to host-supported stages could be seen by a trend to increased leaf areas and masses. δ(13)C values of supported P. edulis or P. tripartita plants were significantly increasing faster than those of non-supported plants once the interactions of leaf mass or nitrogen content per area were accounted for. Hence, the offer of a climbing support had only a minor impact on δ(13)C or δ(15)N values in vitro, but this could be different with increasing age of lianas in vivo.

Below-ground partitioning (14C) and isotopic fractionation (delta13C) of carbon recently assimilated by maize.

Partitioning of carbon recently assimilated by maize between shoots, roots, exudates, and CO2 from root respiration depending on three different levels of nutrient supply (full nutrient solution (NS), 10 times diluted NS, or deionised water) was estimated by 14C pulse labelling. A 13C fractionation in these compartments was investigated in relation to the nutrient supply. With decreasing nutrient supply, 14C allocation to the shoots and to the roots decreased from 76 % to 69 % and increased from 8 % to 13 % of 14C recovery, respectively. Average percentage of 14C in exudates and root-respired CO2 was 0.5 % and 16 % of 14C recovery, respectively. The concentration of the NS was not crucial for the amount of recently assimilated C recovered in exudates and CO2, but for the amounts in shoots and roots. For all three nutrient levels, roots were enriched in 13C when compared with shoots and 13C fractionation increased with decreasing nutrient supply up to 0.7 per thousand. Further 13C discrimination by exudation led to more 13C in exudates when compared with the roots of full nutrient supply and less 13C in exudates when compared with the roots grown in diluted NS and in deionised water. There were only small differences of<1.0 per thousand in delta13C values between roots and CO2 from root respiration. A 13C fractionation of recently assimilated C occurred between roots and exudates but was negligible for the CO2 respired by roots.