Gold Open-Access
Refine
Year of publication
- 2017 (52) (remove)
Document Type
- Article (45)
- Other (2)
- Postprint (2)
- Review (2)
- Master's Thesis (1)
Keywords
- Bergbau (2)
- EDTA (2)
- Myodes glareolus (2)
- NTA (2)
- Puumala virus seroprevalence (2)
- Reisetagebücher (2)
- Sklaverei (2)
- biomimetic mineralization (2)
- biomineralization (2)
- brushite (2)
- calcium phosphate (2)
- flooding (2)
- hydroxyapatite (2)
- precipitation (2)
- 1.5 degrees C (1)
- Abolitionismus (1)
- Akademienvorhaben "Alexander von Humboldt auf Reisen - Wissenschaft aus der Bewegung (1)
- Amerikanische Reisetagebücher (1)
- Apis mellifera (1)
- Arabian carbonate platform (1)
- Arabidopsis-thaliana (1)
- Archaea (1)
- Auger electron spectroscopy (1)
- Bacteria (1)
- Barremian-Aptian (1)
- Berlin (1)
- Beta-diversity (1)
- Bifurkation (1)
- Brillenpinguin (1)
- Bucherwerbungen (1)
- Buchgeschenke (1)
- Bücherkatalog (1)
- Community (1)
- Continuous renal replacement therapy (1)
- Cuba-Manuskript (1)
- Cyanobacteria (1)
- DNA metabarcoding (1)
- DNA methylation (1)
- DPP-4 inhibitors (1)
- Dipeptidyl peptidase IV (1)
- Edelmetalle (1)
- Editionsphilologie (1)
- Electrical Potential (1)
- Essai politique sur l'île de Cuba (1)
- Eukaryota (1)
- Flüsse (1)
- Freshwater (1)
- Förderung (1)
- Geologie (1)
- Geuns, Steven Jan van (1)
- Gold (1)
- Guanaco (1)
- HPLC (1)
- Herneck (1)
- Highest Good (1)
- Humboldt (1)
- Humboldt, Alexander von (1)
- Humboldt-Pinguin (1)
- Indicators of socioeconomic status (1)
- Intensive care (1)
- Kameralismus (1)
- Kant (1)
- Karl Friedrich Neumann (1)
- Kartographie (1)
- Klaus Holzkamp (1)
- Kulturpflanzen (1)
- Königliche Bibliothek Berlin (1)
- Lake (1)
- Larix (1)
- Leopoldina (1)
- MIS 5 to 1 (1)
- Mumien von Ureinwohnern Perus (1)
- NMR-based metabolomics (1)
- Nachlass Alexander von Humboldt (1)
- Nachtrag (1)
- Namensgebung für Humboldt-Pinguin (1)
- Naturkundemuseum zu Berlin (1)
- Nigeria (1)
- Nosema spp. (1)
- Novemberaufstand (1)
- Oxygen Transport (1)
- Pflanzengeographie (1)
- Pharmacokinetics/Pharmacodynamics (1)
- Platin (1)
- Polen (1)
- Polycomb (1)
- Population dynamics (1)
- Praxissemester (1)
- REDD (1)
- RNA (1)
- Reflexivität (1)
- Reiseliteraur (1)
- Renal function (1)
- Risk assessment tool (1)
- Russlandreise (1)
- Sap Flow (1)
- Sediment (1)
- Silber (1)
- Space use (1)
- Stiftung Preußische Seehandlung (1)
- Survival (1)
- Target attainment (1)
- Tree Metabolism (1)
- Tree Stems (1)
- Turnover (1)
- UN-REDD (1)
- USA (1)
- Warburg effect (1)
- Wirtschaftgeschichte (1)
- Wissenschaftsgeschichte (1)
- Xylem (1)
- acquired thermotolerance (1)
- acute kidney injury (1)
- adaptation (1)
- age (1)
- agroecosystem (1)
- alexithymia (1)
- alien species (1)
- ancient DNA (1)
- anti-oxidative response (1)
- assessment (1)
- balance (1)
- beta-Lactam (1)
- biodiversity exploratories (1)
- caffeine (1)
- carotenoid (1)
- change detection (1)
- chromatin (1)
- chronic back pain (1)
- climate change mitigation (1)
- climate policy (1)
- competitive resistance (1)
- consumptive resistance (1)
- culture (1)
- cyberbully-victims (1)
- cyberbullying (1)
- cybervictimization (1)
- defense (1)
- defensives Lernen (1)
- democracy (1)
- developing brain (1)
- education (1)
- enzymatic MIP synthesis (1)
- enzymatic analyte conversion (1)
- enzyme tracer (1)
- epidemiology (1)
- epigenetics (1)
- evaporite minerals (1)
- expansives Lernen (1)
- expectations (1)
- extinct birds (1)
- fertilization (1)
- final end (1)
- gene-expression (1)
- gliptins (1)
- global environmental change (1)
- governance (1)
- green growth (1)
- harmful algae (1)
- health inequality (1)
- herbivory (1)
- honey bee (1)
- hope (1)
- hyperoxia (1)
- hyperspectral (1)
- iCheck (1)
- imagination (1)
- income (1)
- insurance (1)
- ischemia reperfusion injury (1)
- job position (1)
- leaf economics (1)
- legume-grass mixture (1)
- local government (1)
- lutein (1)
- macroeconomic models (1)
- mediation (1)
- metabarcoding (1)
- metal recycling plants (1)
- microbial invasion (1)
- mitochondrial genome (1)
- mixed cropping (1)
- molecularly imprinted polymers (1)
- moral ideal reflective judgment (1)
- mowing (1)
- multi-stage diagenesis (1)
- multitemporal (1)
- museum specimens (1)
- nutrient availability (1)
- nutrient ratios (1)
- ovarian cancer (1)
- oxidative stress (1)
- palaeoenvironment (1)
- palaeogenomics (1)
- perennial crop (1)
- permafrost deposits (1)
- phosphorus (1)
- photochemistry (1)
- photofragmentation (1)
- plant biology (1)
- plant functional traits (1)
- plant strategies (1)
- playa (1)
- pollution indices (1)
- polnische Romantik (1)
- polnische Wissenschaftler (1)
- population dynamics (1)
- potentially toxic elements (1)
- preterm infants (1)
- proprioception (1)
- protein (1)
- prozessorientierte Didaktik (1)
- radiocarbon ages (1)
- remodeling atpase brahma (1)
- replacement (1)
- responses (1)
- risk reduction (1)
- salt pan (1)
- sedaDNA (1)
- seed mass (1)
- shallow-water chemostratigraphy (1)
- single-nucleotide polymorphism (SNP) (1)
- slags (1)
- socioeconomic status (1)
- space use (1)
- spectrophotometry (1)
- sphingosine kinase-1 (1)
- survival (1)
- sustainable investment (1)
- symbolic representation (1)
- technical progress (1)
- template digestion (1)
- training (1)
- transcriptional memory (1)
- transgenerational inheritance (1)
- treeline (1)
- trnL (1)
- ultimate end (1)
- ultrafast dynamics (1)
- vestibular (1)
- vulnerability (1)
- widerständiges Lernen (1)
- wildflower mixture (1)
- yolk (1)
Institute
- Institut für Biochemie und Biologie (16)
- Institut für Romanistik (10)
- Institut für Geowissenschaften (7)
- Institut für Ernährungswissenschaft (3)
- Institut für Physik und Astronomie (3)
- Institut für Umweltwissenschaften und Geographie (3)
- Department Sport- und Gesundheitswissenschaften (2)
- Department Erziehungswissenschaft (1)
- Institut für Chemie (1)
- Institut für Mathematik (1)
Strong experimental evidence in animal and cellular models supports a pivotal role of sphingosine kinase-1 (SK1) in oncogenesis. In many human cancers, SK1 levels are upregulated and these increases are linked to poor prognosis in patients. Here, by employing untargeted NMR- based metabolomic profiling combined with functional validations, we report the crucial role of SK1 in the metabolic shift known as the Warburg effect in A2780 ovarian cancer cells. Indeed, expression of SK1 induced a high glycolytic rate, characterized by increased levels of lactate along with increased expression of the proton/monocarboxylate symporter MCT1, and decreased oxidative metabolism, associated with the accumulation of intermediates of the tricarboxylic acid cycle and reduction in CO2 production. Additionally, SK1-expressing cells displayed a significant increase in glucose uptake paralleled by GLUT3 transporter upregulation. The role of SK1 is not limited to the induction of aerobic glycolysis, affecting metabolic pathways that appear to support the biosynthesis of macromolecules. These findings highlight the role of SK1 signaling axis in cancer metabolic reprogramming, pointing out innovative strategies for cancer therapies.
Sequelae of prematurity triggered by oxidative stress and free radical-mediated tissue damage have coined the term “oxygen radical disease of prematurity”. Caffeine, a potent free radical scavenger and adenosine receptor antagonist, reduces rates of brain damage in preterm infants. In the present study, we investigated the effects of caffeine on oxidative stress markers, anti-oxidative response, inflammation, redox-sensitive transcription factors, apoptosis, and extracellular matrix following the induction of hyperoxia in neonatal rats. The brain of a rat pups at postnatal Day 6 (P6) corresponds to that of a human fetal brain at 28–32 weeks gestation and the neonatal rat is an ideal model in which to investigate effects of oxidative stress and neuroprotection of caffeine on the developing brain. Six-day-old Wistar rats were pre-treated with caffeine and exposed to 80% oxygen for 24 and 48 h. Caffeine reduced oxidative stress marker (heme oxygenase-1, lipid peroxidation, hydrogen peroxide, and glutamate-cysteine ligase catalytic subunit (GCLC)), promoted anti-oxidative response (superoxide dismutase, peroxiredoxin 1, and sulfiredoxin 1), down-regulated pro-inflammatory cytokines, modulated redox-sensitive transcription factor expression (Nrf2/Keap1, and NFκB), reduced pro-apoptotic effectors (poly (ADP-ribose) polymerase-1 (PARP-1), apoptosis inducing factor (AIF), and caspase-3), and diminished extracellular matrix degeneration (matrix metalloproteinases (MMP) 2, and inhibitor of metalloproteinase (TIMP) 1/2). Our study affirms that caffeine is a pleiotropic neuroprotective drug in the developing brain due to its anti-oxidant, anti-inflammatory, and anti-apoptotic properties.
Strong events of long-range transported biomass burning aerosol were detected during July 2013 at three EARLINET (European Aerosol Research Lidar Network) stations, namely Granada (Spain), Leipzig (Germany) and Warsaw (Poland). Satellite observations from MODIS (Moderate Resolution Imaging Spectroradiometer) and CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) instruments, as well as modeling tools such as HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) and NAAPS (Navy Aerosol Analysis and Prediction System), have been used to estimate the sources and transport paths of those North American forest fire smoke particles. A multiwavelength Raman lidar technique was applied to obtain vertically resolved particle optical properties, and further inversion of those properties with a regularization algorithm allowed for retrieving microphysical information on the studied particles. The results highlight the presence of smoke layers of 1-2 km thickness, located at about 5 km a.s.l. altitude over Granada and Leipzig and around 2.5 km a.s.l. at Warsaw. These layers were intense, as they accounted for more than 30% of the total AOD (aerosol optical depth) in all cases, and presented optical and microphysical features typical for different aging degrees: color ratio of lidar ratios (LR532/LR355) around 2, alpha-related angstrom exponents of less than 1, effective radii of 0.3 mu m and large values of single scattering albedos (SSA), nearly spectrally independent. The intensive microphysical properties were compared with columnar retrievals form co-located AERONET (Aerosol Robotic Network) stations. The intensity of the layers was also characterized in terms of particle volume concentration, and then an experimental relationship between this magnitude and the particle extinction coefficient was established.
Lutein is an essential dietary carotenoid with health benefits and is inter alia responsible for the colouration of egg yolk. The relationship between lutein accumulation and egg yolk colouration was therefore studied in more detail. After feeding a low-luteine diet for 21 days, 14 birds (Lohmann brown hens aged 20 weeks) were fed a diet containing marigold (80 mg lutein/kg feed) and 14 other birds were fed a diet containing oleoresin (45 mg lutein/kg feed) for 21 days; for both groups of birds, this feeding period was followed by withdrawal for 21 days. The Roche Yolk Colour Fan (RYCF) score (0 to 15, where higher values denote greater colour intensity; R-2=0.87; P<0.01) and redness (R-2=0.89; P<0.01) increased with increasing lutein content of egg yolk. Total carotenoid content had a poor relationship with lightness (R-2=0.13; P>0.05) and yellowness (R-2=0.12; P>0.05) of the yolk. It may be concluded that increased lutein is potentially responsible for an increased RYCF score and redness (a*), but decreased yellowness (b*) and lightness (L*), of egg yolk.
The Western honey bee (Apis mellifera) is widely used as commercial pollinator in worldwide agriculture and, therefore, plays an important role in global food security. Among the parasites and pathogens threatening health and survival of honey bees are two species of microsporidia, Nosema apis and Nosema ceranae. Nosema ceranae is considered an emerging pathogen of the Western honey bee. Reports on the spread of N. ceranae suggested that this presumably highly virulent species is replacing its more benign congener N. apis in the global A. mellifera population. We here present a 12 year longitudinal cohort study on the prevalence of N. apis and N. ceranae in Northeast Germany. Between 2005 and 2016, a cohort of about 230 honey bee colonies originating from 23 apiaries was sampled twice a year (spring and autumn) resulting in a total of 5,600 bee samples which were subjected to microscopic and molecular analysis for determining the presence of infections with N. apis or/and N. ceranae. Throughout the entire study period, both N. apis- and N. ceranae-infections could be diagnosed within the cohort. Logistic regression analysis of the prevalence data demonstrated a significant increase of N. ceranae-infections over the last 12 years, both in autumn (reflecting the development during the summer) and in spring (reflecting the development over winter) samples. Cell culture experiments confirmed that N. ceranae has a higher proliferative potential than N. apis at 27. and 33 degrees C potentially explaining the increase in N. ceranae prevalence during summer. In autumn, characterized by generally low infection prevalence, this increase was accompanied by a significant decrease in N. apis- infection prevalence. In contrast, in spring, the season with a higher prevalence of infection, no significant decrease of N. apis infections despite a significant increase in N. ceranae infections could be observed. Therefore, our data do not support a general advantage of N. ceranae over N. apis and an overall replacement of N. apis by N. ceranae in the studied honey bee population.
Franz Ferdinand Julius Meyen (1804–1840) veröffentlichte auf sehr vielen Gebieten der Biologie wichtige Arbeiten, vor allem in Botanik und Zoologie. Mit Unterstützung Alexander von Humboldts gelang es ihm, auf dem Forschungsschiff „Prinzess Louise“ anzuheuern und als Schiffsarzt an einer mehrjährigen Weltreise teilzunehmen. Humboldt, der einige Regionen ebenfalls besucht und erforscht hatte, unterstützte seinen jungen Kollegen bei der Vorbereitung seiner Reise. Meyen veröffentlichte seine Reiseergebnisse bereits kurz nach seiner Rückkehr, gefördert von Christian Gottfried Nees von Esenbeck (1776–1858), sowohl als zweiteiligen historischen Reisebericht als auch in sieben Einzelabhandlungen. Einige Ergebnisse, die er, schwerkrank, nicht selbst verwerten konnte, übergab er noch bei Lebzeiten zur Bearbeitung an Spezialisten, andere wurden posthum von Mitgliedern der Leopoldina publiziert. Meyen brachte u. a. eine umfangreiche Sammlung an Vogelpräparaten mit, zu denen auch das Erstbeschreibungsexemplar des von ihm so genannten Spheniscus humboldti (Trivialname: Humboldt-Pinguin) gehört.
Feigning Democracy
(2017)
Reducing Emissions from Deforestation and forest Degradation plus the sustainable management of forest and enhancement of carbon stocks (REDD+) is a global climate change mitigation initiative. The United Nations REDD Programme (UN-REDD) is training governments in developing countries, including Nigeria, to implement REDD+. To protect local people, UN-REDD has developed social safeguards including a commitment to strengthen local democracy to prevent an elite capture of REDD+ benefits. This study examines local participation and representation in the UN-REDD international policy board and in the national-level design process for the Nigeria-REDD proposal, to see if practices are congruent with the UN-REDD commitment to local democracy. It is based on research in Nigeria in 2012 and 2013, and finds that local representation in the UN-REDD policy board and in Nigeria-REDD is not substantive. Participation is merely symbolic. For example, elected local government authorities, who ostensibly represent rural people, are neither present in the UN-REDD board nor were they invited to the participatory forums that vetted the Nigeria-REDD. They were excluded because they were politically weak. However, UN-REDD approved the Nigeria-REDD proposal without a strategy to include or strengthen elected local governments. The study concludes with recommendations to help the UN-REDD strengthen elected local government authority in Nigeria in support of democratic local representation.
Background. Metal recycling factories (MRFs) have developed rapidly in Nigeria as recycling policies have been increasingly embraced. These MRFs are point sources for introducing potentially toxic elements (PTEs) into environmental media. Objectives. The aim of this study was to determine the constituents (elemental and mineralogy) of the wastes (slag and particulate matter, (PM)) and soils around the MRFs and to determine the level of pollution within the area. Methods. Sixty samples (30 slag samples, 15 soil samples and 15 PM samples) were collected for this study. The soils, slag and PM samples were analyzed for elemental constituents using inductively coupled plasma optical emission spectrometry. Mineralogy of the PM was determined using scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), and soil mineralogy was determined by an X-ray diffractometer (XRD). Results. The results of the soil analyses revealed the following concentrations for the selected metals in mg/kg include lead (Pb) (21.0-2399.0), zinc (Zn) (56.0-4188.0), copper (Cu) (10.0-1470.0), nickel (Ni) (6.0-215.0), chromium (Cr) (921.0-1737.0) and cadmium (Cd) (below detectable limit (Bdl)-18.1). For the slags the results were Pb (68.0-.333.0), Zn (1364.0-3062), Cu (119.0-1470.0), Ni (12.0-675.0), Cr (297-1737) and Cd (Bdl-15.8). The results in mu g/g for the metal analysis in PM were Pb (4.6-160.0), Zn (18.0-471.0), Cu (2.5-11.0), Ni (0.8-4.2), and Cr (2.5-11.0), while Cd was undetected. The slags are currently utilized for filling the foundations of buildings and roads, providing additional pathways for the introduction of PTEs into the environment from the suspended materials generated from mechanical breakdown of the slags. Conclusions. The MRFs were found to have impacted the quality of environmental media through the introduction of PTEs, impairing soil quality, in addition to PM, which can have detrimental health consequences. Further studies on the health implications of these pollutants and their impacts on human health are needed. Competing Interests. The authors declare no competing financial interests
Plants frequently have to weather both biotic and abiotic stressors, and have evolved sophisticated adaptation and defense mechanisms. In recent years, chromatin modifications, nucleosome positioning, and DNA methylation have been recognized as important components in these adaptations. Given their potential epigenetic nature, such modifications may provide a mechanistic basis for a stress memory, enabling plants to respond more efficiently to recurring stress or even to prepare their offspring for potential future assaults. In this review, we discuss both the involvement of chromatin in stress responses and the current evidence on somatic, intergenerational, and transgenerational stress memory.
Molecularly imprinted polymers (MIPs) have the potential to complement antibodies in bioanalysis, are more stable under harsh conditions, and are potentially cheaper to produce. However, the affinity and especially the selectivity of MIPs are in general lower than those of their biological pendants. Enzymes are useful tools for the preparation of MIPs for both low and high-molecular weight targets: As a green alternative to the well-established methods of chemical polymerization, enzyme-initiated polymerization has been introduced and the removal of protein templates by proteases has been successfully applied. Furthermore, MIPs have been coupled with enzymes in order to enhance the analytical performance of biomimetic sensors: Enzymes have been used in MIP-sensors as tracers for the generation and amplification of the measuring signal. In addition, enzymatic pretreatment of an analyte can extend the analyte spectrum and eliminate interferences.
Emergency Care in Germany being re-assessed Hybrid Medical Care Model Seen As Potential Answer
(2017)
Platinum electrodes were implanted into the xylem of a lime tree (Tilia cordata) stem and solar- induced electrochemical potential differences of up to 120 mV were measured during the vegetative period and up to 30 mV in winter. The time dependent curves were found to be delayed with respect to solar radiation, sap flow activity, temperature and vapor pressure deficit. A general equation for the potential difference was derived and simplified by analyzing the effect of temperature and tensile strength. The potential determining influence of oxygen concentration on the respective location of the platinum electrode was identified as the principal phenomenon measured. A systematic analysis and investigation of the observed periodic oxygen concentration signals promises new information on sap flow, oxygen diffusion through tree tissues and on oxygen consumption related to the energy turnover in tree tissues.
EDTA and NTA effectively tune the mineralization of calcium phosphate from bulk aqueous solution
(2017)
This study describes the effects of nitrilotriacetic acid (NTA) and ethylenediaminotetraacetic acid (EDTA) on themineralization of calciumphosphate from bulk aqueous solution. Mineralization was performed between pH 6 and 9 and with NTA or EDTA concentrations of 0, 5, 10, and 15 mM. X-ray diffraction and infrared spectroscopy show that at low pH, mainly brushite precipitates and at higher pH, mostly hydroxyapatite forms. Both additives alter the morphology of the precipitates. Without additive, brushite precipitates as large plates. With NTA, the morphology changes to an unusual rod-like shape. With EDTA, the edges of the particles are rounded and disk-like particles form. Conductivity and pH measurements suggest that the final products form through several intermediate steps.
EDTA and NTA effectively tune the mineralization of calcium phosphate from bulk aqueous solution
(2017)
This study describes the effects of nitrilotriacetic acid (NTA) and ethylenediaminotetraacetic acid (EDTA) on themineralization of calciumphosphate from bulk aqueous solution. Mineralization was performed between pH 6 and 9 and with NTA or EDTA concentrations of 0, 5, 10, and 15 mM. X-ray diffraction and infrared spectroscopy show that at low pH, mainly brushite precipitates and at higher pH, mostly hydroxyapatite forms. Both additives alter the morphology of the precipitates. Without additive, brushite precipitates as large plates. With NTA, the morphology changes to an unusual rod-like shape. With EDTA, the edges of the particles are rounded and disk-like particles form. Conductivity and pH measurements suggest that the final products form through several intermediate steps.
ecoAO
(2017)
Although aldehyde oxidase (AO) is an important hepatic drug-metabolizing enzyme, it remains understudied and is consequently often overlooked in preclinical studies, an oversight that has resulted in the failure of multiple clinical trials. AO’s preclusion to investigation stems from the following: (1) difficulties synthesizing metabolic standards due to the chemospecificity and regiospecificity of the enzyme and (2) significant inherent variability across existing in vitro systems including liver cytosol, S9 fractions, and primary hepatocytes, which lack specificity and generate discordant expression and activity profiles. Here, we describe a practical bacterial biotransformation system, ecoAO, addressing both issues simultaneously. ecoAO is a cell paste of MoCo-producing Escherichia coli strain TP1017 expressing human AO. It exhibits specific activity toward known substrates, zoniporide, 4-trans-(N,N-dimethylamino)cinnamaldehyde, O6-benzylguanine, and zaleplon; it also has utility as a biocatalyst, yielding milligram quantities of synthetically challenging metabolite standards such as 2-oxo-zoniporide. Moreover, ecoAO enables routine determination of kcat and V/K, which are essential parameters for accurate in vivo clearance predictions. Furthermore, ecoAO has potential as a preclinical in vitro screening tool for AO activity, as demonstrated by its metabolism of 3-aminoquinoline, a previously uncharacterized substrate. ecoAO promises to provide easy access to metabolites with the potential to improve pharmacokinetic clearance predictions and guide drug development.
DPP4 inhibition prevents AKI
(2017)
A substantial amount of research has revealed that cyberbully-victims have more emotional and behavioral problems than either cyberbullying victims or perpetrators. However, until now, little research has been conducted into the factors that contribute to the interplay between cyberbullying victimization and perpetration. The purpose of this study was to examine the relationship between cyberbullying victimization, perpetration, and two emotional components of alexithymia, namely difficulties in identifying and describing one's own feelings. Self-report questions were administered to 1549 adolescents between 12 and 18 years old (M = 14.51; SD = 1.68; 42.1% (n = 652) male) from Germany and Thailand. Results showed that cyberbullying victimization and alexithymia are associated with cyberbullying perpetration. Moreover, alexithymia mediated the associations between cyberbullying victimization and adolescents' cyberbullying perpetration. Consequently, we suggest that the ability to describe and identify one's own feelings might be important for understanding the link between cyberbullying, victimization, and perpetration. The results may help develop prevention and intervention programs focused on reducing cyberbullying.
Epigenetic maintenance of gene repression is essential for development. Polycomb complexes are central to this memory, but many aspects of the underlying mechanism remain unclear. LIKE HETEROCHROMATIN PROTEIN 1 (LHP1) binds Polycomb-deposited H3K27me3 and is required for repression of many Polycomb target genes in Arabidopsis. Here we show that LHP1 binds RNA in vitro through the intrinsically disordered hinge region. By independently perturbing the RNA-binding hinge region and H3K27me3 (trimethylation of histone H3 at Lys27) recognition, we found that both facilitate LHP1 localization and H3K27me3 maintenance. Disruption of the RNAbinding hinge region also prevented formation of subnuclear foci, structures potentially important for epigenetic repression.
Disentangling shallow‐water bulk carbonate carbon isotope archives into primary and diagenetic components is a notoriously difficult task and even diagenetically screened records often provide chemostratigraphic patterns that significantly differ from global signals. This is mainly caused by the polygenetic nature of shallow‐water carbonate substrates, local carbon cycle processes causing considerable neritic–pelagic isotope gradients and the presence of hiatal surfaces resulting in extremely low carbonate preservation rates. Provided here is an in‐depth petrographic and geochemical evaluation of different carbonate phases of a mid‐Cretaceous (Barremian–Aptian) shallow‐water limestone succession (Jabal Madar section) deposited on the tropical Arabian carbonate platform in Oman. The superposition of stable isotope signatures of identified carbonate phases causes a complex and often noisy bulk carbon isotope pattern. Blocky sparite cements filling intergranular pores and bioclastic voids evidence intermediate to (arguably) deep burial diagenetic conditions during their formation, owing to different timing or differential faulting promoting the circulation of fluids from variable sources. In contrast, sparite cements filling sub‐vertical veins reveal a rock‐buffered diagenetic fluid composition with an intriguing moderate enrichment in 13C, probably due to fractionation during pressure release in the context of the Miocene exhumation of the carbonate platform under study. The presence of abundant, replacive dedolomite in mud‐supported limestone samples forced negative carbon and oxygen isotope changes that are either associated with the thermal breakdown of organic matter in the deep burial realm or the expulsion of buried meteoric water in the intermediate burial realm. Notwithstanding the documented stratigraphically variable and often facies‐related impact of different diagenetic fluids on the bulk‐rock stable isotope signature, the identification of diagenetic end‐members defined δ13C and δ18O threshold values that allowed the most reliable ‘primary’ bulk carbon isotope signatures to be extracted. Most importantly, this approach exemplifies how to place regional shallow‐water stable isotope patterns with evidence for a complex multi‐stage diagenetic history into a supraregional or even global context.