Beyond species loss Valiente-Banuet, Alfonso; Aizen, Marcelo A.; Alcántara, Julio M. ...
Functional ecology,
March 2015, Letnik:
29, Številka:
3
Journal Article
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Summary
The effects of the present biodiversity crisis have been largely focused on the loss of species. However, a missed component of biodiversity loss that often accompanies or even precedes ...species disappearance is the extinction of ecological interactions.
Here, we propose a novel model that (i) relates the diversity of both species and interactions along a gradient of environmental deterioration and (ii) explores how the rate of loss of ecological functions, and consequently of ecosystem services, can be accelerated or restrained depending on how the rate of species loss covaries with the rate of interactions loss.
We find that the loss of species and interactions are decoupled, such that ecological interactions are often lost at a higher rate. This implies that the loss of ecological interactions may occur well before species disappearance, affecting species functionality and ecosystems services at a faster rate than species extinctions. We provide a number of empirical case studies illustrating these points.
Our approach emphasizes the importance of focusing on species interactions as the major biodiversity component from which the ‘health’ of ecosystems depends.
Lay Summary
The transformation of mechanical energy into electrical signals is the first step in mechanotransduction in the peripheral sensory nervous system and relies on the presence of mechanically gated ion ...channels within specialized sensory organs called mechanoreceptors. Piezo2 is a vertebrate stretch‐gated ion channel necessary for mechanosensitive channels in mammalian cells. Functionally, it is related to light touch, which has been detected in murine cutaneous Merkel cell–neurite complexes, Meissner‐like corpuscles and lanceolate nerve endings. To the best of our knowledge, the occurrence of Piezo2 in human cutaneous mechanoreceptors has never been investigated. Here, we used simple and double immunohistochemistry to investigate the occurrence of Piezo2 in human digital glabrous skin. Piezo2 immunoreactivity was detected in approximately 80% of morphologically and immunohistochemically characterized (cytokeratin 20+, chromogranin A+ and synaptophisin+) Merkel cells. Most of them were in close contact with Piezo2− nerve fibre profiles. Moreover, the axon, but not the lamellar cells, of Meissner's corpuscles was also Piezo2+, but other mechanoreceptors, i.e. Pacinian or Ruffini's corpuscles, were devoid of immunoreactivity. Piezo2 was also observed in non‐nervous tissue, especially the basal keratinocytes, endothelial cells and sweat glands. The present results demonstrate the occurrence of Piezo2 in cutaneous sensory nerve formations that functionally work as slowly adapting (Merkel cells) and rapidly adapting (Meissner's corpuscles) low‐threshold mechanoreceptors and are related to fine and discriminative touch but not to vibration or hard touch. These data offer additional insight into the molecular basis of mechanosensing in humans.
Road transportation is heading towards electrification using Li-ion batteries to power electric vehicles offering eight or ten years' warrant. After that, batteries are considered inappropriate for ...traction services but they still have 80% of its original capacity. On the other hand, energy storage devices will have an important role in the electricity market. Being Li-ion batteries still too expensive to provide such services with economic profit, the idea to reuse affordable electric vehicle batteries for a 2nd life originated the Sunbatt project, connecting the automotive and electricity sectors. The battery reuse is, by itself, a path towards sustainability, but the cleanliness of energy storage also depends on the electricity generation power sources and the battery ageing or lifespan. This paper analyses the rest of useful life of 2nd life batteries on four different stationary applications, which are: Support to fast electric vehicle charges, self-consumption, area regulation and transmission deferral. To do so, it takes advantage of an equivalent electric battery-ageing model that simulates the battery capacity fade through its use. This model runs on Matlab and includes several ageing mechanisms, such as calendar ageing, C-rate, Depth-of-Discharge, temperature and voltage. Results show that 2nd life battery lifespan clearly depends on its use, going from about 30 years in fast electric vehicle charge support applications to around 6 years in area regulation grid services. Additionally, this study analyses the day-to-day emissions from electricity generation in Spain, and states that grid oriented energy storage applications will hardly offer environmental benefits in the nearby future. On the other hand, applications that go by the hand of renewable power sources, such as self-consumption applications, are much more appropriate.
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•Lifespan estimation of 2nd life EV batteries on stationary Applications.•Lifespan goes from 30 to 6 years depending on the application.•Battery reuse enhances circular economy.•Grid oriented applications with batteries do not offer environmental benefits.•Batteries should go by the hand of renewable energy power sources.
The ‘centre–periphery hypothesis’ (CPH) is a long‐standing postulate in ecology that states that genetic variation and demographic performance of a species decrease from the centre to the edge of its ...geographic range. This hypothesis is based on an assumed concordance between geographical peripherality and ecological marginality such that environmental conditions become harsher towards the limits of a species range. In this way, the CPH sets the stage for understanding the causes of distribution limits. To date, no study has examined conjointly the consistency of these postulates. In an extensive literature review we discuss the birth and development of the CPH and provide an assessment of the CPH by reviewing 248 empirical studies in the context of three main themes. First, a decrease in species occurrence towards their range limits was observed in 81% of studies, while only 51% demonstrated reduced abundance of individuals. A decline in genetic variation, increased differentiation among populations and higher rates of inbreeding were demonstrated by roughly one in two studies (47, 45 and 48%, respectively). However, demographic rates, size and population performance less often followed CPH expectations (20–30% of studies). We highlight the impact of important methodological, taxonomic, and biogeographical biases on such validation rates. Second, we found that geographic and ecological marginality gradients are not systematically concordant, which casts doubt on the reliability of a main assumption of the CPH. Finally, we attempt to disentangle the relative contribution of geographical, ecological and historical processes on the spatial distribution of genetic and demographic parameters. While ecological marginality gradients explain variation in species' demographic performance better than geographic gradients, contemporary and historical factors may contribute interactively to spatial patterns of genetic variation. We thereby propose a framework that integrates species' ecological niche characteristics together with current and past range structure to investigate spatial patterns of genetic and demographic variation across species ranges.
Emerging evidence suggests that epigenetic regulation is dependent on metabolic state, and implicates specific metabolic factors in neural functions that drive behaviour
. In neurons, acetylation of ...histones relies on the metabolite acetyl-CoA, which is produced from acetate by chromatin-bound acetyl-CoA synthetase 2 (ACSS2)
. Notably, the breakdown of alcohol in the liver leads to a rapid increase in levels of blood acetate
, and alcohol is therefore a major source of acetate in the body. Histone acetylation in neurons may thus be under the influence of acetate that is derived from alcohol
, with potential effects on alcohol-induced gene expression in the brain, and on behaviour
. Here, using in vivo stable-isotope labelling in mice, we show that the metabolism of alcohol contributes to rapid acetylation of histones in the brain, and that this occurs in part through the direct deposition of acetyl groups that are derived from alcohol onto histones in an ACSS2-dependent manner. A similar direct deposition was observed when mice were injected with heavy-labelled acetate in vivo. In a pregnant mouse, exposure to labelled alcohol resulted in the incorporation of labelled acetyl groups into gestating fetal brains. In isolated primary hippocampal neurons ex vivo, extracellular acetate induced transcriptional programs related to learning and memory, which were sensitive to ACSS2 inhibition. We show that alcohol-related associative learning requires ACSS2 in vivo. These findings suggest that there is a direct link between alcohol metabolism and gene regulation, through the ACSS2-dependent acetylation of histones in the brain.
The present research examined the relationship between political ideology and perceptions of the threat of COVID-19. Due to Republican leadership’s initial downplaying of COVID-19 and the resulting ...partisan media coverage, we predicted that conservatives would perceive it as less threatening. Two preregistered online studies supported this prediction. Conservatism was associated with perceiving less personal vulnerability to the virus and the virus’s severity as lower, and stronger endorsement of the beliefs that the media had exaggerated the virus’s impact and that the spread of the virus was a conspiracy. Conservatism also predicted less accurate discernment between real and fake COVID-19 headlines and fewer accurate responses to COVID-19 knowledge questions. Path analyses suggested that presidential approval, knowledge about COVID-19, and news discernment mediated the relationship between ideology and perceived vulnerability. These results suggest that the relationship between political ideology and threat perceptions may depend on issue framing by political leadership and media.
Acro‐ischaemia in hospitalized COVID‐19 patients Suarez‐Valle, A.; Fernandez‐Nieto, D.; Diaz‐Guimaraens, B. ...
Journal of the European Academy of Dermatology and Venereology,
September 2020, Letnik:
34, Številka:
9
Journal Article
Most species are exposed to significant environmental gradients across their ranges, but vital rates (survival, growth, reproduction and recruitment) need not respond in the same direction to those ...gradients. Opposing vital rate trends across environments, a phenomenon that has been loosely called ‘demographic compensation’, may allow species to occupy larger geographical ranges and alter their responses to climate change. Yet the term has never been precisely defined, nor has its existence or strength been assessed for multiple species. Here, we provide a rigorous definition, and use it to develop a strong test for demographic compensation. By applying the test to data from 26 published, multi‐population demographic studies of plants, we show that demographic compensation commonly occurs. We also investigate the mechanisms by which this phenomenon arises by assessing which demographic processes and life stages are most often involved. In addition, we quantify the effect of demographic compensation on variation in population growth rates across environmental gradients, a potentially important determinant of the size of a species’ geographical range. Finally, we discuss the implications of demographic compensation for the responses of single populations and species’ ranges to temporal environmental variation and to ongoing environmental trends, e.g. due to climate change.
The COVID-19 pandemic triggered vast governmental lockdowns. The impact of these lockdowns on mental health is inadequately understood. On the one hand such drastic changes in daily routines could be ...detrimental to mental health. On the other hand, it might not be experienced negatively, especially because the entire population was affected.
The aim of this study was to determine mental health outcomes during pandemic induced lockdowns and to examine known predictors of mental health outcomes. We therefore surveyed n = 9,565 people from 78 countries and 18 languages. Outcomes assessed were stress, depression, affect, and wellbeing. Predictors included country, sociodemographic factors, lockdown characteristics, social factors, and psychological factors.
Results indicated that on average about 10% of the sample was languishing from low levels of mental health and about 50% had only moderate mental health. Importantly, three consistent predictors of mental health emerged: social support, education level, and psychologically flexible (vs. rigid) responding. Poorer outcomes were most strongly predicted by a worsening of finances and not having access to basic supplies.
These results suggest that on whole, respondents were moderately mentally healthy at the time of a population-wide lockdown. The highest level of mental health difficulties were found in approximately 10% of the population. Findings suggest that public health initiatives should target people without social support and those whose finances worsen as a result of the lockdown. Interventions that promote psychological flexibility may mitigate the impact of the pandemic.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Diversity of ageing across the tree of life Jones, Owen R; Scheuerlein, Alexander; Salguero-Gómez, Roberto ...
Nature (London),
01/2014, Letnik:
505, Številka:
7482
Journal Article
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Evolution drives, and is driven by, demography. A genotype moulds its phenotype's age patterns of mortality and fertility in an environment; these two patterns in turn determine the genotype's ...fitness in that environment. Hence, to understand the evolution of ageing, age patterns of mortality and reproduction need to be compared for species across the tree of life. However, few studies have done so and only for a limited range of taxa. Here we contrast standardized patterns over age for 11 mammals, 12 other vertebrates, 10 invertebrates, 12 vascular plants and a green alga. Although it has been predicted that evolution should inevitably lead to increasing mortality and declining fertility with age after maturity, there is great variation among these species, including increasing, constant, decreasing, humped and bowed trajectories for both long- and short-lived species. This diversity challenges theoreticians to develop broader perspectives on the evolution of ageing and empiricists to study the demography of more species.
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