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The recovery of European freshwater biodiversity has come to a halt
Owing to a long history of anthropogenic pressures, freshwater ecosystems are among the most vulnerable to biodiversity loss. Mitigation measures, including wastewater treatment and hydromorphological restoration, have aimed to improve environmental quality and foster the recovery of freshwater biodiversity. Here, using 1,816 time series of freshwater invertebrate communities collected across 22 European countries between 1968 and 2020, we quantified temporal trends in taxonomic and functional diversity and their responses to environmental pressures and gradients. We observed overall increases in taxon richness (0.73% per year), functional richness (2.4% per year) and abundance (1.17% per year). However, these increases primarily occurred before the 2010s, and have since plateaued. Freshwater communities downstream of dams, urban areas and cropland were less likely to experience recovery. Communities at sites with faster rates of warming had fewer gains in taxon richness, functional richness and abundance. Although biodiversity gains in the 1990s and 2000s probably reflect the effectiveness of water-quality improvements and restoration projects, the decelerating trajectory in the 2010s suggests that the current measures offer diminishing returns. Given new and persistent pressures on freshwater ecosystems, including emerging pollutants, climate change and the spread of invasive species, we call for additional mitigation to revive the recovery of freshwater biodiversity
Co-application of the GABAB receptor agonist, baclofen, and of the mGlu receptor agonist, L-CCG-I, facilitate [3H]GABA release from rat cortical nerve endings.
Interaction between different transmitter receptor
systems is an emerging feature of neurotransmission at
central synapses. G protein-coupled receptors\u2019 ability to
form dimers or larger hetero-oligomers probably serves to
facilitate the integration of diverse signals within the cell.
We found that, in nerve terminals isolated from the cerebral
cortices of rats, co-application of the GABAB agonist,
baclofen, and of the non-selective mGlu agonist, L-CCG-I,
potentiates the basal and depolarization-evoked release of
[3H]GABA via a mechanism that involves mobilization of
intracellular Ca2? ions. The effect of L-CCG-I ? baclofen
was abolished by the phospholipase C inhibitor U73122,
reduced by Xestospongin C (an IP3 receptor blocker), and
blocked by 2-APB, an IP3 receptor antagonist. Pretreatment
of the synaptosomes with the lipid-soluble Ca2? chelator
BAPTA-AM also inhibited the effects of L-CCGI
? baclofen. Subtype-selective non-competitive group I
mGlu receptor antagonists, MPEP and CPCCOEt, had no
effect on the release enhancement produced by baclofen
? L-CCG-I. The enhancement was reversed by the
GABAB receptor antagonist, CGP54626, and by the group
I/group II mGlu receptor antagonist (R,S)-MCPG. The
GABA release-enhancing effects of L-CCG-I ? baclofen
in our model might reflect the presence on cortical nerve
endings of GABAB/group I mGlu receptor heteromers with
pharmacological properties distinct from those of the
component receptors. Activation of these heteromeric
receptors might modify the function of the GABAB
receptor in such a way that it facilitates GABAergic
transmission, an effect that might be useful under conditions
of excessive glutamatergic activity
Measuring the albedo deuteron flux in the PAMELA satellite experiment
The results of measuring albedo deuteron fluxes in the vicinity of the Earth are presented. The data were obtained in the PAMELA experiment conducted aboard the Resurs DK-1 artificial Earth satellite. High-precision detectors of the instrument setup allow us to identify albedo deuterons and measure their spectra in the energy interval from 70 to 600 MeV/nucleon at altitudes of 350\u2013600 km for different geomagnetic latitudes