TOI-2015 is a known exoplanetary system around an M4 dwarf star, consisting of a transiting sub-Neptune planet in a 3.35-day orbital period, TOI-2015 b, accompanied by a non-transiting companion, TOI-2015 c. High-precision radial-velocity measurements were taken with the MAROON-X spectrograph, and high-precision photometric data were collected, primarily using the SPECULOOS, MUSCAT, TRAPPIST and LCOGT networks. We collected 63 transit light curves and 49 different transit epochs for TOI-2015 b. We recharacterized the target star by combining optical spectra obtained by the MAROON-X, Shane/KAST and IRTF/SpeX spectrographs, Bayesian model averaging (BMA) and spectral energy distribution (SED) analysis. The TOI-2015 host star is a K = 10.3 mag M4-type dwarf with a subsolar metallicity of [Fe/H] = −0.31 ± 0.16, and an effective temperature of Teff ≈ 3200 K. Our photodynamical analysis of the system strongly favors the 5:3 mean-motion resonance and in this scenario the planet b (TOI-2015 b) has an orbital period of Pb = 3.34 days, a mass of Mp = 9.02-0.36+0.32M⊕ , and a radius of Rp = 3.309-0.011+0.013R⊕ , resulting in a density of ρp = 0.25 ± 0.01 ρ⊕ = 1.40 ± 0.06 g cm−3; this is indicative of a Neptune-like composition. Its transits exhibit large (> 1 hr) timing variations characteristic of an outer perturber in the system. We performed a global analysis of the high-resolution radial-velocity measurements, the photometric data, and the TTVs, and inferred that TOI-2015 hosts a second planet, TOI-2015 c, in a non-transiting configuration. Our analysis places it near a 5:3 resonance with an orbital period of Pc = 5.583 days and a mass of Mp = 8.91-0.40+0.38M⊕. The dynamical configuration of TOI-2015 b and TOI-2015 c can be used to constrain the system’s planetary formation and migration history. Based on the mass-radius composition models, TOI-2015 b is a water-rich or rocky planet with a hydrogen-helium envelope. Moreover, TOI-2015 b has a high transmission-spectroscopic metric (TSM=149), making it a favorable target for future transmission spectroscopic observations with the JWST to constrain the atmospheric composition of the planet. Such observations would also help to break the degeneracies in theoretical models of the planet’s interior structure.
Weniger anzeigenMediterranean cyclones can trigger severe weather hazards, including convective precipitation, lightning and hail, with implications for operational forecasting, risk assessment in the insurance industry, and societal preparedness. This work examines the climatological link between Mediterranean cyclones and atmospheric conditions conducive to severe convection. Using ATDnet lightning detections we find that, from autumn to spring, 20%–80% of lightning hours over the Mediterranean basin and adjacent land regions are associated with nearby cyclones. Based on reanalysis data, we demonstrate that severe convective environments and associated hazards predominantly occur in the warm sector of Mediterranean cyclones and to the north-east of their centres. Convective processes and hazards exhibit a peak approximately 6 h prior to the time of minimum pressure of the cyclone centre, consistent with previous studies. Additionally, we find a strong seasonal dependence of severe convection within cyclones. Severe convective environments are often detected in cyclone types typical of transition seasons (autumn especially) and summer, while they are rarer in deep baroclinic cyclones characteristic of winter. Finally, we provide novel insights regarding the dependence of convective activity on the presence of dynamical features around Mediterranean cyclones. Warm conveyor belts, characterised by large-scale ascent and high thermodynamic instability, emerge as the most favourable regions for lightning activity, with lightning potential being twice as high compared to cyclone cold fronts. These results advance our understanding of the interplay between cyclone dynamics and severe convection, offering valuable guidance for improving hazard prediction and for elaborating weather emergency strategies in the Mediterranean region.
Weniger anzeigenAt the 6th International Conference of the Global Bioequivalence Harmonisation Initiative (GBHI), co-organised by the European Federation of Pharmaceutical Sciences (EUFEPS) and the Product Quality Research Institute (PQRI), critical bioequivalence (BE) topics were discussed by pharmaceutical scientists from academia, industry and regulatory agencies, revealing the following main conclusions: (1) Physiologically based pharmacokinetic/biopharmaceutic modelling (PBPK/PBBM) for solid oral drugs: PBPK/PBBM gains increasing recognition for generic drug development, e.g. waivers of fed studies and drug interaction studies with proton pump inhibitors. However, especially for complex formulations containing low-solubility compounds, more data are needed for modelling-based conclusion regarding BE in fed state. (2) Narrow therapeutic index drugs: A progress towards harmonisation of BE criteria from US-FDA and EMA speakers was made as there is consensus in the usefulness of applying a mixed scale for BE acceptance range depending on variability, via either fully or partially replicated design. Differences still remain regarding variability comparison and the selection of regulatory constant (0.760 vs. 1.05361). All parties confirmed the importance of controlling type-I error. (3) Single- vs. multiple-dose studies for BE demonstration of modified-release (MR) products: To circumvent multiple-dose studies, model-informed approaches were discussed based on real-life data, e.g. to simulate steady-state profiles from single-dose data. To reduce the burden in patient trials for long-acting injectables promising modelling approaches were presented, extrapolating from incomplete steady-state scenarios. (4) BE demonstration for additional dose strengths of solid oral MR products: For multiple-unit dosage forms where strengths differ in number of units only, testing BE of the highest dose was considered sufficient. In addition, there was some consensus that, whenever extrapolation from one strength to the others is not easily established, the “bracket-approach” of the EMA focusing on the intake conditions in the label claim (fasted or fed), can help mitigating risks without adding significant cost and effort. (5) Partial AUC for BE demonstration: Clinical relevance is key to decide on the relevant PK metrics for BE assessment whenever possible. There was consensus that the BE criteria and evaluation strategy may be best specified in product-specific guidances – preferably with international harmonisation. (6) BE of orally inhaled drug products (OIDPs): The “weight-of-evidence” approach of US-FDA and the stepwise approach of EMA largely differ. The auditorium was in favour of combining data on in-vitro characteristics and PK exposure. For prediction of comparable efficacy of two OIDPs, there is good trust in PK exposure data whenever they present concentrations being absorbed via the lung. GBHI has a strong role in scientifically supporting official harmonisation efforts including the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use since the first conference in 2015.
Weniger anzeigenCyanobacteria oxygenated the atmosphere of early Earth and continue to be key players in global carbon and nitrogen cycles. A phylogenetically diverse subset of extant cyanobacteria can perform photosynthesis with far-red light through a process called far-red light photoacclimation, or FaRLiP. This phenotype is enabled by a cluster of ∼20 genes and involves the synthesis of red-shifted chlorophylls d and f, together with paralogs of the ubiquitous photosynthetic machinery used in visible light. The FaRLiP gene cluster is present in diverse, environmentally important cyanobacterial groups, but its origin, evolutionary history, and connection to early biotic environments have remained unclear. This study takes advantage of the recent increase in (meta)genomic data to help clarify this issue: sequence data mining, metagenomic assembly, and phylogenetic tree networks were used to recover more than 600 new FaRLiP gene sequences, corresponding to 51 new gene clusters. These data enable high-resolution phylogenetics and—by relying on multiple gene trees, together with gene arrangement conservation—support FaRLiP appearing early in cyanobacterial evolution. Sampling information shows that considerable FaRLiP diversity can be observed in microbialites to the present day, and we hypothesize that the process was associated with the formation of microbial mats and stromatolites in the early Paleoproterozoic. The ancestral FaRLiP cluster was reconstructed, revealing features that have been maintained for billions of years. Overall, far-red-light-driven oxygenic photosynthesis may have played a significant role in Earth’s early history.
Weniger anzeigenBentonite is a key barrier material in deep geological facilities for spent nuclear fuel, where it may be exposed to temperatures >100 °C because of radiogenic heating. Understanding how prolonged heating affects its physicochemical properties and radionuclide retention capacity is critical for ensuring long-term repository safety. This study investigated the impacts of dry heating (unconfined, evaporation allowed) at 150 °C for 36 months on the mineralogical and geochemical stability of a Wyoming bentonite, chosen for the Finnish geological disposal facility, and its subsequent sorption behavior with 90Sr. Although the bentonite mineralogy remained mostly stable, combined X-ray diffraction, cation exchange capacity, titrations, demonstrated partial Na to Ca exchange within montmorillonite's interlayer following heating, and specific surface area analyses revealed a > 50 % reduction in specific surface area (30 to 14 m2/g). Colloid stability tests revealed that bentonite colloids did not form under repository-relevant saline conditions (I = 0.2 M), and heat treatment did not significantly impact colloid formation in reduced ionic-strength systems. Sorption isotherms demonstrated that Sr sorption was strongly pH-dependent, increasing from ∼40 % at pH 8 to ∼90 % at pH 13, and heating slightly enhanced Sr retention at pH 8. Two-site protolysis non-electrostatic surface complexation and cation exchange modelling suggested that in unheated bentonite, Sr was bound via a combination of surface complexation (∼30 %) and cation exchange (∼70 %) at pH 8, while at pH 13, sorption shifted towards surface complexation. However, after heating, cation exchange dominated at both pH values. Extended X-ray absorption fine structure analysis confirmed outer-sphere Sr sorption at pH 8 and increasing inner-sphere complexation at pH 13. Together, these findings highlight that despite minor physicochemical alterations, bentonite retained its Sr sorption potential, supporting its continued suitability as a buffer material in the ONKALO® repository.
Weniger anzeigenFemale rhinoceroses have an ovarian reserve that consists of immature oocytes in primordial follicles. Establishing methods to grow and culture these oocytes from those follicles in the laboratory might fuel efforts towards in vitro embryo production in this species without the need for repeated in vivo oocyte collection. In depth understanding of the biology behind and improvement of assisted reproductive techniques (ARTs) is the only option for preventing the disappearance of functionally extinct species such as the northern white rhinoceros. In vitro follicle development can only be obtained by in depth knowledge on rhinoceros ovarian histology. In addition to known ovarian features, we identified numerous undescribed structural and molecular ovarian characteristics from adult southern white rhinoceros (n=3). Ovarian sections were stained with H&E, PAS or Masson Trichrome and molecular analyses (hyaluronic acid detection, immunohistochemistry and TUNEL assay) were performed to identify proliferation, extracellular matrix, pluripotency markers, hormones, enzymes, markers for inflammation or endocrine glands, blood vessel presence, oocyte markers and apoptosis. Besides degenerating, deformed, or luteinized follicles, analysis revealed several ‘follicle-like structures’ (FLS) that deviated from the expected follicle appearance. Most importantly, the majority of FLS did not contain any oocyte and were comprised of a collection of cells organised around fluid islands with or without an antral cavity. The discovery and description of FLS in aged southern white rhinoceroses may play a role in poor oocyte recovery rates in ovum pick-up (OPU) in older rhinoceroses. It remains to be investigated whether FLS might be present on ovaries from other rhinoceros species and whether they might serve as a general indicator for oocyte recovery success in aged females.
Weniger anzeigen1. In recent years, seismic sensors, traditionally used in geophysical studies, have been utilized to record seismic waves generated by wildlife locomotion, providing new ways to monitor wildlife non-invasively and continuously. Given the novelty of this approach, numerous research questions, unexplored potentials, and methodological challenges remain. 2. In this study, we investigate the seismic signal properties of African savanna species during locomotion and employ machine learning techniques to classify wildlife based on these footfall signals. We utilize the SeisSavanna dataset, which contains over 70,000 three-component seismograms paired with labelled images from co-located camera traps. To create a graphical overview of the entire seismic dataset, we combine a scattering transform with uniform manifold approximation and projection (UMAP). While the different wildlife categories display different footfall patterns, local geological conditions known as site effects significantly alter the frequency content of those signals. To address the issue of the site effect, we trained machine learning models on data recorded on various sites. 3. For a multi-class classification task involving signals from elephants, giraffes, hyenas, and zebras, the models achieved a balanced accuracy of 87% at a maximum animal-sensor distance of 50 m. The accuracy decreases to 77% when the maximum distance is extended to 150 m due to decreasing signal and label quality. We demonstrate that the models can generalize to new seismic stations if similar site conditions are present in the training data. 4. Our results indicate the potential for using seismic signals in wildlife monitoring and conservation, complementing other existing passive monitoring sensors such as camera traps or acoustic loggers with new observables about silent species. However, further methodological advancements and larger datasets are essential for this approach to become a reliable tool in wildlife monitoring.
Weniger anzeigenArtificial light at night (ALAN) is an omnipresent anthropogenic stressor disrupting ecological interactions, potentially driving rapid evolutionary change. However, evidence for genetic adaptation to ALAN remains limited, with ecological responses dominating observed effects. Here, we critically review current evidence for evolution under ALAN and propose that interactions between ecological and evolutionary processes—so-called eco-evolutionary feedbacks—may obscure direct evolutionary signals. We argue for more common-garden experiments to disentangle genetic adaptation from environmentally induced plasticity, for multiple study organisms. Using a conceptual framework of an urban freshwater pond and a key ecological interactor, the water flea Daphnia, we illustrate how ALAN may affect key ecological phenomena, including diel vertical migration, parasite infection, and top-down control of algae, and may impose complex and cascading selection pressures. Recognizing interactions between ecological and evolutionary processes provides new insights on how light pollution can influence ecosystem health and inform conservation strategies in increasingly illuminated environments.
Weniger anzeigenSolid phase synthesis (SPS) offers a bottom-up approach for assembling (bio-)oligomers and polymers with precise molecular detail. Although SPS has been applied to various organic compounds, it is expressly convenient for assembling biopolymers. Fundamental studies and optimization efforts have focused solely on organic chemistry aspects, often neglecting physicochemical issues. Here, we summarize the current understanding of the physical phenomena occurring in the gel-like, solvent-swollen polymer beads used commonly as a solid support, aiming to help advance SPS by providing new insights based on physicochemical principles.
Weniger anzeigenProlactin is a protein hormone that plays a regulating role in many physiological processes across mammalian species, but the two primary functions it exerts are the development of the mammary glands and milk production. This review will focus on the potential key role of prolactin in the hormonal control of maternal investment and survival in mammals. Prolactin has been demonstrated to influence maternal investment throughout the complete investment process from ovulation and implantation to gestation and lactation, highlighting its essential role in this balance. Different stressors may affect prolactin secretion, and therefore, be a trigger to lower or stop maternal investment. Hence, comprehending prolactin's function in maternal investment and survival strategies can have important implications for our understanding of reproductive success and failure, potentially benefiting conservation efforts to protect endangered species. Since the role of prolactin is inconsistent in different mammalian species, species-specific research is mandatory to determine the exact role of prolactin in individual maternal survival-investment strategies. The current knowledge on this topic is highlighted in the present review but is also illustrative of the fact that many areas of prolactin related research remain underexposed.
Weniger anzeigenConsumers are often exposed to prior reviews when considering posting themselves. We examine how finding one’s opinion in the minority (vs. majority) of previous ratings affects a consumer’s decision to post. Specifically, we contrast the posting decisions of frequent posters with those of less frequent posters. Results from seven experimental studies show that frequent posters prefer review environments in which their opinion belongs to the minority of previously posted ratings. We support these findings with additional evidence from secondary review data. This behavior sets them apart from infrequent posters, who are reluctant to share minority opinions. In addition, we show that this effect is driven by differences in how a minority post is perceived: As an opportunity to signal one’s reviewer identity or as socially risky. Based on these insights, we explore how rating platforms can motivate review posting, particularly among infrequent posters. Our findings extend previous research on social influence effects in online reviews and have implications for various stakeholders who rely on and aim to solicit reviews on rating platforms.
Weniger anzeigenOkapi (Okapia johnstoni) belong to the Giraffidae family and is the only representative of the Okapia genus. The species has been declared as endangered and due to its very elusive nature, little is known about its reproductive behavior. The wild population has continued to decrease over the last decades despite the different conservation programs developed worldwide. Captive breeding is difficult and the European population is not self-sustaining. An alternative tool to prevent the extinction of this charismatic species is the use of assisted reproductive technologies (ART). Specifically, we introduce a novel protocol for the in vitro maturation (IVM) and cryopreservation of matured oocytes obtained post-mortem. Out of sixteen cumulus-oocytes complexes isolated from one deceased individual, four matured metaphase II (MII) oocytes were successfully obtained following IVM. Furthermore, these matured oocytes demonstrated resilience during the vitrification/warming process and underwent sperm injection. Although no embryos were obtained, this study represents the first step towards the application of ART in okapi, providing a foundation for future reproductive interventions aimed at preserving self-sustaining captive populations.
Weniger anzeigenFood processing by-products such as mango peel and apple pectin present valuable sources of dietary fibre, pectins and various other beneficial compounds for pig nutrition. The study's objective was to explore the effects of incorporating mango peel and apple pectin into pig feed. Batch fermentations using sow faeces were conducted to assess the fermentability of the substrates over a 24-hour incubation period. Subsequently, a feeding experiment was conducted using post-weaning piglets to examine the impact of adding 1 % or 2 % (w/w) mango peel and apple pectin to their diet. The in vitro fermentation studies with sow faeces showed increasing lactate and short-chain fatty acid concentrations when apple and mango pectin were added as substrates. The feeding trial indicated no significant impact on piglets' performance, nor the apparent praecaecal digestibility of crude protein was altered, while the apparent praecaecal digestibility of crude fat decreased with the addition of 1 % apple pectin, but increased with 2 % mango peel. Concentrations of microbial metabolites in the digesta were similar, and only slight variations were observed in the bacterial levels as determined by qPCR. In the treatment groups, enhanced utilisation of mango peel and apple pectin by the faecal microbiota was noted compared to the control group (BIOLOG test). In summary, incorporating small quantities of mango peel and apple pectin resulted in only mild alterations within the piglets' digestive system. Additional research to determine the optimal levels for effective usage of mango peels and apple pectin in piglet diets is required.
Weniger anzeigenTwo growth modes are recognized in colonial pterobranchs (Graptolithina): monopodial growth and sympodial growth. The earliest colonial Graptolithina likely developed through monopodial growth, a mode of colony formation well-documented in the extant graptolite Rhabdopleura normani. This growth involves a permanent terminal zooid and the sequential budding of additional zooids behind it, as the contractile stalk (gymnocaulus) of this terminal zooid elongates. This process is reflected in specific features of the secreted housing structure, the tubarium. Recently, monopodial growth was identified for the first time in a fossil taxon—the Cambrian dithecodendrid Tarnagraptus—based on tubarium characteristics, as no zooids were preserved. Monopodial growth also appears probable in other Cambrian taxa resembling Tarnagraptus, although evidence remains limited due to fragmentary materials. Sympodial growth, characterized by transient terminal zooids that are sequentially replaced as new buds form, is extensively documented in the fossil record of the Graptolithina. This growth mode characterizes the vast majority of Cambrian to Devonian Dendroidea and Graptoloidea. Phylogenetic evidence suggests sympodial growth evolved from monopodial growth in graptolithines, but the mechanisms underlying this evolutionary transition remain unclear.
Weniger anzeigenAnthropogenic stressors on Caribbean reefs have shifted coral dominance toward stress-tolerant species such as Siderastrea siderea, increasing their importance for reef construction. However, the sublethal responses of these corals to past stressors remain understudied, limiting our understanding of their long-term acclimatization capacity. Here, we reconstructed the annual skeletal growth rates (1912–2020) of twelve S. siderea coral colonies from Martinique (Caribbean Sea) and examined their relationships with changes in human population, sea surface temperature (SST), precipitation, river discharge, and agricultural indicators between 1950 and 2020. Long-term growth rate declines observed since the 1950s were initially associated with human population, a proxy for local stress. Warming SST enhanced coral skeletal growth between 1950 and 1985, suggesting optimal temperatures for calcification during this interval. However, skeletal density exhibited a multidecadal (1950–2020) parabolic response, indicating a surpassing of this thermal optimum in recent decades. This parabolic response included persistent skeletal density declines from 2010 to 2020, possibly related to cumulative thermal stress or the interaction with ocean acidification effects. Our findings suggest a limited acclimatization capacity of long-lived S. siderea corals to cumulative pressures in Martinique and highlight their vulnerability to the compounding effects of local stressors and climate change.
Weniger anzeigenExtension of the light period causes photoperiod stress in Arabidopsis thaliana. The photoperiod stress phenotype is characterized by an induction of stress and cell death marker genes, the formation of reactive oxygen species (ROS) and enhanced formation of jasmonates during the night following the extended light period. Previously, experiments had shown that the jar1-1 mutant, carrying a point mutation in the jasmonoyl-isoleucine (JA-Ile) biosynthesis gene JAR1, showed a strongly reduced stress phenotype suggesting that JA-Ile is required for the stress response. Here, we have analyzed the roles of JA-Ile and JAR1 in more detail. While jar1-1 reduced the photoperiod stress phenotype indicating that JAR1 is required for the response to photoperiod stress, mutation of the ALLENE OXIDE SYNTHETASE (AOS) jasmonate biosynthesis gene did not rescue the stress phenotype. Further, analysis of jasmonate signaling mutants did not indicate their broad resistance to photoperiod stress. Unexpectedly, other JAR1 mutant alleles like jar1-11 and fin219-2 did not alleviate the photoperiod stress phenotype. Genetic analysis revealed that a recessive unlinked second-site mutation in the jar1-1 mutant background is responsible for the suppression of the photoperiod stress response. Taken together, these results suggest that JA-Ile is less important for the response to photoperiod stress than indicated by previous results.
Weniger anzeigenAntimicrobial resistance (AMR) poses a critical global health challenge, prompting the exploration of antimicrobial peptides (AMPs) as alternatives. Here, we investigated the genetic mechanisms of resistance evolution in Staphylococcus aureus against single and combined AMPs (temporin, melittin, and pexiganan). Whole-genome sequencing of evolved populations revealed that combination therapy significantly reduced the overall number of mutations, and importantly, did not typically lead to broad multi-AMP resistance. Instead, resistance likely focused on one component of the combination. While mutations in pmtR (toxin transport) and tagO (wall-teichoic acid biosynthesis) were common across treatments, AMP-specific mutations, such as dagK and msrR, were also identified. Notably, mutations in a hypothetical membrane protein operon (SAOUHSC_02307–02309) imply a potential pexiganan resistance pathway. The findings suggest that AMP combinations might limit mutation accumulation, while constraining the development of general AMP resistance. The genetic mechanism of resistance is complex, thus careful selection is required for designing effective AMP-based therapies.
Weniger anzeigenAs global digitization continues to grow, technology becomes more affordable and easier to use, and social media platforms thrive, becoming the new means of spreading information and news. Communities are built around sharing and discussing current events. Within these communities, users are enabled to share their opinions about each event. Using Sentiment Analysis to understand the polarity of each message belonging to an event, as well as the entire event, can help to better understand the general and individual feelings of significant trends and the dynamics on online social networks. In this context, we propose a new ensemble architecture, EDSA-Ensemble (Event Detection Sentiment Analysis Ensemble), that uses Event Detection and Sentiment Analysis to improve the detection of the polarity for current events from Social Media. For Event Detection, we use techniques based on Information Diffusion taking into account both the time span and the topics. To detect the polarity of each event, we preprocess the text and employ several Machine and Deep Learning models to create an ensemble model. The preprocessing step includes several word representation models: raw frequency, TFIDF, Word2Vec, and Transformers. The proposed EDSA-Ensemble architecture improves the event sentiment classification over the individual Machine and Deep Learning models.
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