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Highlights
• Determination of styrene-butadiene rubber as tire constituent using TED-GC/MS.
• Determination of zinc content as tire constituent using ICP-OES.
• Representative sampling strategy with large-volume mixed samples.
• Tire wear content is decreasing with increasing sampling depth and distance to road.
• Deposited tire wear particles are mainly present in soil fraction <100 μm.
Abstract
Tire wear (TW) constitutes a significant source of microplastic in terrestrial ecosystems. It is known that particles emitted by roads can have an effect up to 100 m into adjacent areas. Here, we apply for the first-time thermal extraction desorption gas chromatography-mass spectrometry (TED-GC/MS) to determine TW in soil samples by detection of thermal decomposition products of styrene-butadiene rubber (SBR), without additional enrichment. Additionally, zinc contents were determined as an elemental marker for TW. Mixed soil samples were taken along three transects along a German motorway in 0.3, 2.0, and 5.0 m distance from the road. Sampling depths were 0–2, 2–5, 5–10, and 10–20 cm. Four fine fractions, 1 000–500, 500–100, 100–50, and <50 μm, were analyzed.
TW contents based on SBR ranged from 155 to 15 898 mg kg−1. TW contents based on zinc were between 413 and 44 812 mg kg−1. Comparison of individual values of SBR and zinc reveals SBR as a more specific marker. Results confirm that most TW ends up in the topsoil within a 2 m distance.
The sampling strategy resulted in representative data for a larger area. Standard deviations of quadruple TED-GC/MS determination of SBR were <10% for all grain size fractions. TED-GC/MS is a suitable analytical tool for determining TW in soil samples without the use of toxic chemicals, enrichment, or special sample preparation.
Reactive oxygen species (ROS) are constant by-products of aerobic life. In excess, ROS lead to cytotoxic protein aggregates, which are a hallmark of ageing in animals and linked to age-related pathologies in humans. Acylamino acid-releasing enzymes (AARE) are bifunctional serine proteases, acting on oxidized proteins. AARE are found in all domains of life, albeit under different names, such as acylpeptide hydrolase (APEH/ACPH), acylaminoacyl peptidase (AAP), or oxidized protein hydrolase (OPH). In humans, AARE malfunction is associated with age-related pathologies, while their function in plants is less clear. Here, we provide a detailed analysis of AARE genes in the plant lineage and an in-depth analysis of AARE localization and function in the moss Physcomitrella and the angiosperm Arabidopsis. AARE loss-of-function mutants have not been described for any organism so far. We generated and analysed such mutants and describe a connection between AARE function, aggregation of oxidized proteins and plant ageing, including accelerated developmental progression and reduced life span. Our findings complement similar findings in animals and humans, and suggest a unified concept of ageing may exist in different life forms.
Protein oxidation results from the reaction of amino-acid side chains with reactive oxygen species (ROS) and is partly irreversible. In non-photosynthetic tissues, mitochondria are a main source of ROS, whereas plastids are the major source in photosynthetic tissues. Oxidized proteins suffer from decreased structural integrity and even loss of function, and their accumulation leads to cytotoxic aggregates. In mammals, aggregate formation correlates with aging and is linked to several age-related pathologies. Mammalian proteolytic pathways for clearance of oxidized proteins are under intensive research, while mechanistic insights into this process in plants is scarce. Acylamino acid-releasing (AARE) enzymes are ATP-independent serine proteases, presumably acting on oxidized proteins and operating in a dual exo-/endopeptidase mode. They are found in all domains of life. Here, we investigated AARE enzymes in the moss Physcomitrella and the angiosperm Arabidopsis and identified three homologous nuclear genes in Physcomitrella (PpAARE1-3) and a single nuclear gene in Arabidopsis (AtAARE). Surprisingly, we observed triple localization of the proteins AtAARE and PpAARE1 to plastids, mitochondria and the cytosol in vivo, likely conserved across the plant lineage. This represents an ATP-independent possibility for degradation of oxidized proteins in the major source organelles of ROS in plants, which is distinct to mammals. Combinatorial knockout plants and protein interaction analysis revealed specific interactions of the moss AARE isoforms and functions in progressive aging. Analysis of an AtAARE T-DNA mutant further suggests the evolutionary conservation of AARE function in age-related development.
Reactive oxygen species (ROS) are constant by-products of aerobic life. In excess, ROS lead to cytotoxic protein aggregates, which are a hallmark of ageing in animals and linked to age-related pathologies in humans. Acylamino acid-releasing enzymes (AARE) are bifunctional serine proteases, acting on oxidized proteins. AARE are found in all domains of life, albeit under different names, such as acylpeptide hydrolase (APEH/ACPH), acylaminoacyl peptidase (AAP), or oxidized protein hydrolase (OPH). In humans, AARE malfunction is associated with age-related pathologies, while their function in plants is less clear. Here, we provide a detailed analysis of AARE genes in the plant lineage and an in-depth analysis of AARE localization and function in the moss Physcomitrella and the angiosperm Arabidopsis. AARE loss-of-function mutants have not been described for any organism so far. We generated and analysed such mutants and describe a connection between AARE function, aggregation of oxidized proteins and plant ageing, including accelerated developmental progression and reduced life span. Our findings complement similar findings in animals and humans, and support a unified concept of ageing.
Diurnal and nocturnal behaviour of cheetahs (Acinonyx jubatus) and lions (Panthera leo) in zoos
(2022)
Mammals are constantly exposed to exogenous and endogenous influences that affect their behaviour and daily activity. Light and temperature, as well as anthropogenic factors such as husbandry routines, visitors, and feeding schedules are potential influences on animals in zoological gardens. In order to investigate the effects of some of these factors on animal behaviour, observational studies based on the analyses of activity budgets can be used. In this study, the daily and nightly activity budgets of six lions (Panthera leo) and five cheetahs (Acinonyx jubatus) from four EAZA institutions were investigated. Focused on the influencing factor light and feeding, we analysed these activity budgets descriptively. Behaviour was recorded and analysed during the winter months over an observation period of 14 days and 14 nights using infrared-sensitive cameras. Our results show that lions and cheetahs exhibit activity peaks at crepuscular and feeding times, regardless of husbandry. Thus, lions in captivity shift nocturnal behaviour familiar from the wild to crepuscular and diurnal times. In cheetahs, in contrast, captive and wild individuals show similar 24 h behavioural rhythms. The resting behaviour of both species is more pronounced at night, with cheetahs having a shorter overall sleep duration than lions. This study describes the results of the examined animals and is not predictive. Nevertheless, the results of this study make an important contribution to gaining knowledge about possible factors influencing the behaviour of lions and cheetahs in zoos and offer implications that could be useful for improving husbandry and management.
The success of the increasing use of technology in education is highly dependent on learner acceptance. Although the Technology Acceptance Model (TAM) is dominant in research for surveying acceptance of technology, it does not allow the prediction of a successful first time use of technology. The successful first time use can be determined with the survey of technology affinity, as it corresponds to the expression of certain personality traits of users and is thus detached from the specific technology. Since there are no measurement instruments for the educational sector so far and existing instruments for measuring technology affinity do not meet the specific requirements for use in the educational context (e.g., limited time for questioning), we present the single item Inclusion of Technology Affinity in Self-Scale (ITAS). In study 1 we provide evidence of convergent and discriminant validity within the general population so that a generalization of its applicability is possible. In study 2 we subsequently tested ITAS in the actual target group, the educational sector. The high correlations of the ITAS with the ATI and the control instrument TA-EG (ranging from rs = 0.679 to rs = 0.440) show that ITAS is suitable for use in research. Furthermore, the newly developed instrument convinces with its low complexity, the graphical component, which requires little text understanding and the high time saving. This research thus can contribute to the investigation of technology affinity in the educational sector helping educators to conduct technical activities with their learning group, to predict possible difficulties and adjust their planning accordingly.
Microplastics are small plastic fragments that are widely distributed in marine and terrestrial environments. While the soil ecosystem represents a large reservoir for plastic, research so far has focused mainly on the impact on aquatic ecosystems and there is a lack of information on the potentially adverse effects of microplastics on soil biota. Earthworms are key organisms of the soil ecosystem and are due to their crucial role in soil quality and fertility a suitable and popular model organism in soil ecotoxicology.
Therefore, the aim of this study was to gain insight into the effects of environmentally relevant concentrations of microplastics on the earthworm Eisenia andrei on multiple levels of biological organization after different exposure periods. Earthworms were exposed to two types of microplastics: (1) polystyrene-HBCD and (2) car tire abrasion in natural soil for 2, 7, 14 and 28 d. Acute and chronic toxicity and all subcellular investigations were conducted for all exposure times, avoidance behavior assessed after 48 h and reproduction after 28 d. Subcellular endpoints included enzymatic biomarker responses, namely, carboxylesterase, glutathione peroxidase, acetylcholinesterase, glutathione reductase, glutathione S-transferase and catalase activities, as well as fluorescence-based measurements of oxidative stress-related markers and multixenobiotic resistance activity. Multiple biomarkers showed significant changes in activity, but a recovery of most enzymatic activities could be observed after 28 d. Overall, only minor effects could be observed on a subcellular level, showing that in this exposure scenario with environmentally relevant concentrations based on German pollution levels the threat to soil biota is minimal. However, in areas with higher concentrations of microplastics in the environment, these results can be interpreted as an early warning signal for more adverse effects. In conclusion, these findings provide new insights regarding the ecotoxicological effects of environmentally relevant concentrations of microplastics on soil organisms.
Spatial genome organization is tightly controlled by several regulatory mechanisms and is essential for gene expression control. Nuclear receptors are ligand-activated transcription factors that modulate physiological and pathophysiological processes and are primary pharmacological targets. DNA binding of the important loop-forming insulator protein CCCTC-binding factor (CTCF) was modulated by 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3). We performed CTCF HiChIP assays to produce the first genome-wide dataset of CTCF long-range interactions in 1,25(OH)2D3-treated cells, and to determine whether dynamic changes of spatial chromatin interactions are essential for fine-tuning of nuclear receptor signaling. We detected changes in 3D chromatin organization upon vitamin D receptor (VDR) activation at 3.1% of all observed CTCF interactions. VDR binding was enriched at both differential loop anchors and within differential loops. Differential loops were observed in several putative functional roles including TAD border formation, promoter-enhancer looping, and establishment of VDR-responsive insulated neighborhoods. Vitamin D target genes were enriched in differential loops and at their anchors. Secondary vitamin D effects related to dynamic chromatin domain changes were linked to location of downstream transcription factors in differential loops. CRISPR interference and loop anchor deletion experiments confirmed the functional relevance of nuclear receptor ligand-induced adjustments of the chromatin 3D structure for gene expression regulation.
Aim
How species respond to climate change is influenced by their sensitivity to climatic conditions (i.e. their climatic niche) and aspects of their adaptive capacity (e.g. their dispersal ability and ecological niche). To date, it is largely unknown whether and how species’ sensitivity to climate change and their adaptive capacity covary. However, understanding this relationship is important to predict the potential consequences of a changing climate for species assemblages. Here, we test how species’ sensitivity to climate change and trait-based measures of their ecological adaptive capacity (i) vary along a broad elevational gradient and (ii) covary across a large number of bird species.
Location
A Neotropical elevational gradient (300–3600 m.a.s.l.) in the Manú Biosphere Reserve, south-east Peru.
Methods
We focus on 215 frugivorous bird species along a Neotropical elevational gradient. We approximate species’ sensitivity to climate change by their climatic niche breadth, based on species occurrences across South America and bioclimatic variables. In addition, we use a trait-based approach to estimate the dispersal ability of species (approximated by their wing pointedness), their dietary niche breadth (approximated by bill width) and their habitat niche breadth (the number of used habitat classes).
Results
We found that (i) species’ climatic niche breadth increased with elevation, while their trait-based dispersal ability and dietary niche breadth decreased with elevation, and (ii) sensitivity to climate change and trait-based adaptive capacity were not related across species.
Main conclusions
These results suggest different mechanisms of how species in lowland and highland assemblages might respond to climate change. The independent variation of species’ sensitivity to climate change and their trait-based adaptive capacity suggests that accounting for both dimensions will improve assessments of species’ susceptibility to climate change and potential impacts of climate change on diverse species assemblages.