| 1. |
- Kraemer, Benjamin M., et al.
(författare)
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Climate change drives widespread shifts in lake thermal habitat
- 2021
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Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 11:6, s. 521-529
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Tidskriftsartikel (refereegranskat)abstract
- Lake surfaces are warming worldwide, raising concerns about lake organism responses to thermal habitat changes. Species may cope with temperature increases by shifting their seasonality or their depth to track suitable thermal habitats, but these responses may be constrained by ecological interactions, life histories or limiting resources. Here we use 32 million temperature measurements from 139 lakes to quantify thermal habitat change (percentage of non-overlap) and assess how this change is exacerbated by potential habitat constraints. Long-term temperature change resulted in an average 6.2% non-overlap between thermal habitats in baseline (1978-1995) and recent (1996-2013) time periods, with non-overlap increasing to 19.4% on average when habitats were restricted by season and depth. Tropical lakes exhibited substantially higher thermal non-overlap compared with lakes at other latitudes. Lakes with high thermal habitat change coincided with those having numerous endemic species, suggesting that conservation actions should consider thermal habitat change to preserve lake biodiversity. Using measurements from 139 global lakes, the authors demonstrate how long-term thermal habitat change in lakes is exacerbated by species' seasonal and depth-related constraints. They further reveal higher change in tropical lakes, and those with high biodiversity and endemism.
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| 2. |
- Pilla, Rachel M., et al.
(författare)
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Global data set of long-term summertime vertical temperature profiles in 153 lakes
- 2021
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Ingår i: Scientific Data. - : Springer Nature. - 2052-4463. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Climate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change.
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| 3. |
- Pilla, Rachel M., et al.
(författare)
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Deeper waters are changing less consistently than surface waters in a global analysis of 102 lakes
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Globally, lake surface water temperatures have warmed rapidly relative to air temperatures, but changes in deepwater temperatures and vertical thermal structure are still largely unknown. We have compiled the most comprehensive data set to date of long-term (1970–2009) summertime vertical temperature profiles in lakes across the world to examine trends and drivers of whole-lake vertical thermal structure. We found significant increases in surface water temperatures across lakes at an average rate of + 0.37 °C decade−1, comparable to changes reported previously for other lakes, and similarly consistent trends of increasing water column stability (+ 0.08 kg m−3 decade−1). In contrast, however, deepwater temperature trends showed little change on average (+ 0.06 °C decade−1), but had high variability across lakes, with trends in individual lakes ranging from − 0.68 °C decade−1 to + 0.65 °C decade−1. The variability in deepwater temperature trends was not explained by trends in either surface water temperatures or thermal stability within lakes, and only 8.4% was explained by lake thermal region or local lake characteristics in a random forest analysis. These findings suggest that external drivers beyond our tested lake characteristics are important in explaining long-term trends in thermal structure, such as local to regional climate patterns or additional external anthropogenic influences.
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| 4. |
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| 5. |
- La Spina, M, et al.
(författare)
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Multiple Mechanisms Converging on Transcription Factor EB Activation by the Natural Phenol Pterostilbene
- 2021
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Ingår i: Oxidative medicine and cellular longevity. - : Hindawi Limited. - 1942-0994 .- 1942-0900. ; 2021, s. 7658501-
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Tidskriftsartikel (refereegranskat)abstract
- Pterostilbene (Pt) is a potentially beneficial plant phenol. In contrast to many other natural compounds (including the more celebrated resveratrol), Pt concentrations producing significant effects in vitro can also be reached with relative ease in vivo. Here we focus on some of the mechanisms underlying its activity, those involved in the activation of transcription factor EB (TFEB). A set of processes leading to this outcome starts with the generation of ROS, attributed to the interaction of Pt with complex I of the mitochondrial respiratory chain, and spreads to involve Ca2+ mobilization from the ER/mitochondria pool, activation of CREB and AMPK, and inhibition of mTORC1. TFEB migration to the nucleus results in the upregulation of autophagy and lysosomal and mitochondrial biogenesis. Cells exposed to several μM levels of Pt experience a mitochondrial crisis, an indication for using low doses in therapeutic or nutraceutical applications. Pt afforded significant functional improvements in a zebrafish embryo model of ColVI-related myopathy, a pathology which also involves defective autophagy. Furthermore, long-term supplementation with Pt reduced body weight gain and increased transcription levels of Ppargc1a and Tfeb in a mouse model of diet-induced obesity. These in vivo findings strengthen the in vitro observations and highlight the therapeutic potential of this natural compound.
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| 6. |
- Reguitti, A., et al.
(författare)
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SN 2021foa, a transitional event between a Type IIn (SN 2009ip-like) and a Type Ibn supernova
- 2022
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 662
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Tidskriftsartikel (refereegranskat)abstract
- We present photometric and spectroscopic data of the unusual interacting supernova (SN) 2021foa. It rose to an absolute magnitude peak of Mr = −18 mag in 20 days. The initial light curve decline shows some luminosity fluctuations before a long-lasting flattening. A faint source (Mr ∼ −14 mag) was detected in the weeks preceding the main event, showing a slowly rising luminosity trend. The r-band absolute light curve is very similar to those of SN 2009ip-like events, with a faint and shorter duration brightening (‘Event A’) followed by a much brighter peak (‘Event B’). The early spectra of SN 2021foa show a blue continuum with narrow (∼400 km s−1) H emission lines that, two weeks later, reveal a complex profile, with a narrow P Cygni on top of an intermediate-width (∼2700 km s−1) component. At +12 days, metal lines in emission appear and He I lines become very strong, with He I λ5876 reaching half of the Hα luminosity, much higher than in previous SN 2009ip-like objects. We propose that SN 2021foa is a transitional event between the H-rich SN 2009ip-like SNe and the He-rich Type Ibn SNe.
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| 7. |
- Sharma, Sapna, et al.
(författare)
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A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009
- 2015
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Ingår i: Scientific Data. - : Macmillan Publishers Limited. - 2052-4463. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues.
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| 8. |
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| 9. |
- Jenny, Jean Philippe, et al.
(författare)
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Scientists’ Warning to Humanity: Rapid degradation of the world's large lakes
- 2020
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Ingår i: Journal of Great Lakes Research. - : Elsevier BV. - 0380-1330. ; 46:4, s. 686-702
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Forskningsöversikt (refereegranskat)abstract
- © 2020 The Authors Large lakes of the world are habitats for diverse species, including endemic taxa, and are valuable resources that provide humanity with many ecosystem services. They are also sentinels of global and local change, and recent studies in limnology and paleolimnology have demonstrated disturbing evidence of their collective degradation in terms of depletion of resources (water and food), rapid warming and loss of ice, destruction of habitats and ecosystems, loss of species, and accelerating pollution. Large lakes are particularly exposed to anthropogenic and climatic stressors. The Second Warning to Humanity provides a framework to assess the dangers now threatening the world's large lake ecosystems and to evaluate pathways of sustainable development that are more respectful of their ongoing provision of services. Here we review current and emerging threats to the large lakes of the world, including iconic examples of lake management failures and successes, from which we identify priorities and approaches for future conservation efforts. The review underscores the extent of lake resource degradation, which is a result of cumulative perturbation through time by long-term human impacts combined with other emerging stressors. Decades of degradation of large lakes have resulted in major challenges for restoration and management and a legacy of ecological and economic costs for future generations. Large lakes will require more intense conservation efforts in a warmer, increasingly populated world to achieve sustainable, high-quality waters. This Warning to Humanity is also an opportunity to highlight the value of a long-term lake observatory network to monitor and report on environmental changes in large lake ecosystems.
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| 10. |
- Nava, Veronica, et al.
(författare)
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Plastic debris in lakes and reservoirs
- 2023
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 619:7969, s. 317-322
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Tidskriftsartikel (refereegranskat)abstract
- Plastic debris is thought to be widespread in freshwater ecosystems globally(1). However, a lack of comprehensive and comparable data makes rigorous assessment of its distribution challenging(2,3). Here we present a standardized cross-national survey that assesses the abundance and type of plastic debris (>250 mu m) in freshwater ecosystems. We sample surface waters of 38 lakes and reservoirs, distributed across gradients of geographical position and limnological attributes, with the aim to identify factors associated with an increased observation of plastics. We find plastic debris in all studied lakes and reservoirs, suggesting that these ecosystems play a key role in the plastic-pollution cycle. Our results indicate that two types of lakes are particularly vulnerable to plastic contamination: lakes and reservoirs in densely populated and urbanized areas and large lakes and reservoirs with elevated deposition areas, long water-retention times and high levels of anthropogenic influence. Plastic concentrations vary widely among lakes; in the most polluted, concentrations reach or even exceed those reported in the subtropical oceanic gyres, marine areas collecting large amounts of debris(4). Our findings highlight the importance of including lakes and reservoirs when addressing plastic pollution, in the context of pollution management and for the continued provision of lake ecosystem services.
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