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Trait space and compactness: A new perspective on explaining variations in primary productivity
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Contrasting evolution of the Arabian Sea and Pacific Ocean oxygen minimum zones during the Miocene
No full textOcean oxygen minimum zones have expanded since the mid-20th century, yet their future remains uncertain. Previous studies show that the eastern tropical North Pacific was well oxygenated during the warm Miocene Climatic Optimum (17.0–14.8 Ma), suggesting better oxygenation under climatic warming. To explore whether this response was global, we reconstruct Miocene oxygenation in the second largest oxygen minimum zone, the Arabian Sea. Trace elements and nitrogen isotopes in planktonic foraminifera show that the Arabian Sea was also better oxygenated during the Miocene Climatic Optimum than today. However, deoxygenation history and establishment of a true oxygen deficient zone following the Miocene cooling lagged in the Arabian Sea, indicating the important role of regional oceanographic processes like proto-monsoon or Tethys outflow. Our study supports future projections of deoxygenation reversals in both oxygen minimum zones, but with more complexity in the Arabian Sea due to competing changes in monsoonal upwelling and influx from marginal seas
“Nobody should control the end user”: {E}xploring Privacy Perspectives of Indian Internet Users in Light of {DPDPA}
No full textReceptor-specific noradrenergic modulation of oscillatory dynamics during non-rapid eye movement sleep in adult male rats
No full textCortical slow oscillations (SO, ∼1 Hz), which are hallmarks of non-rapid eye movement (NREM) sleep, temporally organize thalamocortical spindles (10-16 Hz) and hippocampal ripples (∼150 Hz), thereby promoting coordinated activity within the thalamocortical-hippocampal (TCH) network. Although markedly reduced during NREM sleep, the firing of noradrenergic neurons and norepinephrine (NE) release are temporally coordinated with SOs and spindles. We assessed the acute impact of pharmacologically targeting adrenergic receptors (ARs) on the oscillatory dynamics during NREM sleep. We recorded local field potentials from the parietal cortex and the dorsal hippocampus in freely behaving adult male rats. To examine receptor-specific effects, we injected intraperitoneally prazosin (α1-AR antagonist, 0.5 mg/kg), propranolol (β-AR antagonist, 10 mg/kg), or clonidine (α2-AR agonist, 0.05 mg/kg). Adrenergic treatment produced state- and receptor-specific alterations of sleep oscillations and affected their cross-frequency and cross-regional coupling. The most pronounced effects were observed after α2-AR activation and combined blockade of α1-and β-ARs. Namely, these treatments suppressed SOs and ripples while promoting sleep spindles; blockage of β-ARs mainly affected the SO rate, and α1-antagonist alone had no effect. Clonidine and the synergistic action of propranolol and prazosin weakened the hippocampal-cortical coupling (ripple/spindle and ripple/SO, respectively); clonidine also modulated the grouping of sleep spindles around SOs. Our findings revealed the state- and receptor-specific noradrenergic modulation of the oscillatory dynamics within the TCH network during NREM sleep. These alterations may have functional implications for sleep quality, homeostatic regulation, and sleep-dependent cognitive processes, and should be considered when using noradrenergic medication
Photo-alignment kinetics of azobenzene in the nanopores of the metal-organic framework HKUST-1
No full textAzobenzene molecules in the pores of metal-organic frameworks can be aligned by polarized light. To use this effect for an opto-optical switch in data processing, it needs to be enhanced and its kinetics must be understood. Here, we study the switching kinetics in detail which is enabled by a six-fold increase in switching contrast reached by 2-step azobenzene loading process. We observe bi-exponential behavior over time and correlate it with a rate-equation model. The bi-exponential behavior of the switching with non-polarized light proofs that the azobenzene molecules align parallel to the propagation direction of the light, in addition to the known alignment perpendicular to the polarization plane
Grenzüberschreitender Verbraucherschutz: § 17 Internationale Zuständigkeit, § 18 Anwendbares Recht
No full textNew Phytologist
No full textSummary Chromatin organization and histone modifications play essential roles in regulating gene expression during development. DEK is a conserved chromatin-associated protein implicated in DNA topology and transcriptional regulation, yet its in vivo function in plants has remained elusive. To uncover DEK function, we used Arabidopsis thaliana dek mutants and performed genome-wide analyses of histone modifications. Genetic and physical interactions with Polycomb Repressive Complex 2 (PRC2)-associated proteins were examined, and transcriptome comparisons were conducted among single and multiple mutants. Loss of DEK function led to a genome-wide increase in the PRC2-mediated histone modification H3K27me3. DEK genetically and physically interacts with the PRC2-associated protein LIKE HETEROCHROMATIN PROTEIN 1 (LHP1), and DEK deficiency partially restores H3K27me3 levels in the lhp1 mutant. The dek multiple mutant exhibited enhanced H3K27me3 at PRC2 target genes and ectopic accumulation at pericentromeric interstitial telomeric repeats ? similar to histone H1 mutants ? suggesting altered chromatin accessibility. Combined dek and lhp1 mutations intensified developmental defects and disrupted expression of many PRC2 target genes, including MADS-box transcription factors. Transcriptome analyses revealed that DEK and chromatin remodeler alpha thalassemia/mental retardation syndrome X-linked chromatin remodeler have opposing effects on gene expression. Our findings uncover DEK as a novel regulator of H3K27me3 homeostasis and chromatin structure, critical for coordinated plant development