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Frequent Queen Replacement and Presence of Unrelated Queens in Colonies of a Functionally Monogynous Ant Species
Get PDFIn eusocial insects, social parasitism—the exploitation of the host's brood care behavior for survival and reproduction—can occur either within or between species. Parasitic queens invade host nests and aggressively replace the resident queen. While the adoption of conspecific queens is a common feature of species with multiqueen colonies (polygyny), the origin of parasitic founding is not fully understood. Functionally monogynous ants, in which nestmate queens establish social and reproductive hierarchies through biting and antennal boxing, may provide a link between peaceful adoption and social parasitism. In this study, we investigated whether alien queens can usurp colonies of the functionally monogynous ant Leptothorax gredleri. Ovary dissection of queens from 33 nests showed that multiple queens with developed ovaries can occasionally co-occur in the same nest. Genetic analysis revealed frequent replacement of the dominant queens by relatives. Instead, alien queens rarely take over reproduction, suggesting a few occurrences of intraspecific social parasitism. However, the data suggest that alien queens without developed ovaries frequently invade nests without being eliminated. This suggests that alien queens are somehow prevented from reproducing and social parasitism is therefore limited in this species
Eckhard, Jesse (2023): Interventionen. Zur (Zeit‑)Geschichte und zur Politikwissenschaft. Parteien, Extremismus, Wahlen
Get PDFThe Mechanosensitive PIEZO1 Channel Contributes to the Reaction of RAW264.7 Macrophages to Mechanical Strain
Get PDFThe mechanosensitive channel ‘piezo type mechanosensitive ion channel component 1’ (PIEZO1) plays a regulatory role in the response of periodontal ligament fibroblasts (PDLFs) to the mechanical strain that occurs during orthodontic tooth movement. In addition to PDLFs, immune cells such as macrophages are also exposed to mechanical stimuli. Macrophages respond to mechanical strain with increased expression of inflammatory mediators. The role of PIEZO1 in this response remains elusive. To investigate the effect of PIEZO1 activation, RAW264.7 macrophages were stimulated with the PIEZO1 activator YODA1 without concurrent application of pressure. To further examine the specific role of PIEZO1 during mechanical strain, RAW264.7 macrophages were exposed to mechanical strain without and with simultaneous inhibition of PIEZO1 either by chemical inhibition (GsMTx4) or siRNA silencing. The expression of genes and proteins involved in orthodontic tooth movement was examined by quantitative PCR, western blot, and enzyme-linked immunosorbent assay (ELISA). Activation of PIEZO1 by YODA1 or mechanical strain increased the expression of inflammatory cytokines and osteoprotegerin (Opg), which is critically involved in bone remodeling processes. Conversely, inhibition of the PIEZO1 channel attenuates the effects of mechanical stress. In conclusion, our data demonstrate that the PIEZO1 channel is a major contributor to the response of macrophages to mechanical strain encountered during orthodontic tooth movement and affects the expression of inflammatory and bone remodeling factors
The association between relative fat mass (RFM) and lumbar bone density in US adults: Insight from 2011–2018 NHANES
Get PDFBackground
The relationship between obesity and osteoporosis has been widely studied. Studies
have shown that relative fat mass (RFM) can be used to predict obesity. However, its
relationship with bone mineral density (BMD) is unclear. The aim of this study was to
investigate the relationship between RFM and lumbar BMD.
Methods
We used data from the National Health and Nutrition Examination Survey (NHANES)
from 2011 to 2018. Multiple linear regression models were applied to examine the
relationship between RFM and lumbar BMD. We used smoothed curve fitting and
threshold effect analysis to check for non-linear trends. Subgroup analyses were
performed to explore differences in various populations. The Receiver operating characteristic
(ROC) curve was used to evaluate the diagnostic potential of body mass
index (BMI), weight-adjusted waist circumference index (WWI), waist circumference
(WC), and RFM for OP.
Results
A total of 10636 participants were included. Multiple linear regression showed a
significant negative link between RFM and lumbar BMD. In subgroup studies and
smoothed curve fitting, RFM was consistently associated with lower BMD across
subgroups. ROC curve indicate that RFM is more sensitive than BMI, WWI and WC
in diagnosing OP capacity.
Conclusion
RFM is negatively associated with lumbar BMD in US adults. This suggests that RFM
contributes to the study of low BMD
Cost for research - How cost data of research can be included in open metadata to be reused and evaluated
Get PDFMorphological effects of input data quantity in AI-powered dental crown design
Get PDFObjectives:
This retrospective in vitro study evaluated the impact of input data quantity on the morphology of dental crowns generated by AI-based software. The hypothesis suggests that increased input data quantity improves the quality of generated occlusal surfaces.
Methods:
A dataset comprising n=30 patients (11 males, 19 females; age: 22–31 years) was analyzed. Input data was categorized into full dentition (full), quadrant data (quad), and adjacent teeth (adj). AI-based software (Dentbird Crown, Imageworks Inc.) generated crowns for a single lower first molar (36/46). Metrics were proposed to assess the morphology and occlusal relationships of the crowns, with the original tooth as reference. Statistics: Friedman Chi-Square tests, Wilcoxon signed rank tests, Kendall correlation and Fligner–Killeen tests (α= 0.05).
Results:
Full and quad groups provided consistent reconstruction quality with no significant differences in morphology and occlusal relationships. The adj group showed significant () morphological deviations and higher reconstruction failure rates compared to the full and quad groups. Correlations (median: 0.19; min–max range: 0.01–0.54) indicate that the proposed metrics capture distinct morphological and functional crown aspects.
Conclusion:
The software reliably reconstructed crowns with at least quadrant-level input data. Performance declined with reduced input. Full-jaw scans did not enhance accuracy compared to quadrant data.
Clinical Significance:
Increased input data quantity can improve the accuracy of AI-based restorations. As a result, prosthodontists benefit from predictable, accurate restoration proposals that reduce the need for digital chairside adjustments as well as manual modifications after fabrication. This streamlines clinical workflows and enhances the quality of restorations. Quadrant-level data has proven sufficient to generate high-quality reconstructions. Further input data did not significantly improve the accuracy of the reconstructions. The proposed metrics enable quantitative assessments of morphological and functional restoration quality, supporting reliable AI-driven workflows
Functional Characterization of the SARS-CoV-2 Nucleocapsid Protein
No full textIn late 2019, SARS-CoV-2 caused a global pandemic with severe health issues, leading to widespread morbidity and mortality. The SARS-CoV-2 Nucleocapsid (N) protein is a multifunctional protein and crucial for viral replication and pathogenesis. This study comprehensively explored the intricate functions and mechanisms of the N protein, focusing on its interactions with nucleic acids and host cell surface components.
Through a series of biochemical and biophysical assays, distinct functional domains within the N protein responsible for its interaction with RNA, were identified. Generally, the N protein comprises two structured domains, the RNA-binding domain (RBD) and the C-terminal domain (CTD), which are flanked and interconnected by three intrinsically disordered regions (IDRs). The RBD in combination with the IDR2 were found to be essential for ssRNA binding, while the combined action of RBD, IDR2, and CTD facilitated efficient dsRNA binding. The N protein was discovered to harbor an intrinsic RNA chaperone activity. This activity is crucial for RNA packaging as well as for the efficient and accurate folding of the viral RNA genome. The experiments revealed the RBD, IDR2, and CTD to be essential for this function.
Comparative analysis between the Wuhan and Omicron BA.5 N protein variants revealed significant differences in RNA chaperone activity. The BA.5 N exhibited reduced chaperone activity, which can be restored by protein phosphorylation. Additionally, phosphorylation decreases RNA binding affinity, necessary for RNA release into the host cytoplasm to facilitate viral replication. These findings suggest distinct regulatory mechanisms between the variants and highlight the crucial role of phosphorylation in RNA packaging and release.
This study also uncovered a novel mechanism of the N protein involving extracellular liquid-liquid phase separation with heparin and heparan sulfate on the host cell surface during viral infection, suggesting another host evasion mechanism by shielding heparan sulfate, which is essential for antiviral immune response, and heparin, which is necessary for anti-coagulation during infection. Additionally, this study found that the cell surface bound N protein triggers the release of proinflammatory cytokines TNF and IL-8, potentially contributing to the cytokine storm observed in COVID-19 cases.
In conclusion, this study provided a detailed understanding of the SARS-CoV-2 N protein regarding its intrinsic functions and potential immune modulatory mechanisms. It fills key knowledge gaps in the basic mechanisms of SARS-CoV-2 infection and established a foundation for future research aimed at targeting N as a therapeutic strategy
Essays on Government Policies in Finance and Real Estate Finance
No full textThe finance and real estate sectors are central to economic development and societal well-being, yet both face pressing challenges shaped by regulatory frameworks and dynamic market conditions. Academic research cannot remain detached from these debates. Instead, rigorous empirical analyses are essential to identify areas where governmental regulation and market mechanisms can be improved, providing evidence-based policy guidance. This dissertation contributes to this endeavor by offering independent policy advice based on data-driven analyses.
The thesis consists of three empirical studies, each addressing a politically relevant question at the intersection of finance, real estate, and public policy. Together, these studies demonstrate how academic research can bridge the gap between theory and practice, supporting more effective policymaking.
The first paper, The Effect of Commission Bans on Household Wealth: Evidence from OECD Countries, investigates the implications of regulatory reforms in financial advisory markets. It shows that banning commission-based remuneration increases household wealth returns by better aligning advisor incentives with client outcomes. The findings move beyond classical debates around financial literacy by highlighting broader institutional factors that shape regulatory change.
The second paper, Does Residential Land Development Pay off Fiscally?, examines the fiscal consequences of residential land development for German municipalities. Using spatial econometric models, it demonstrates that residential development can significantly raise municipal income tax revenues. This evidence challenges the prevalent municipal preference for commercial land development, which is primarily motivated by business tax revenues. Instead, the results support a proactive residential land policy, which not only enhances fiscal capacity but also addresses severe housing shortages.
The third paper, Living on the Highway? Addressing Highway Infrastructure Potential through Object Detection, explores the acute shortage of Heavy Goods Vehicle (HGV) parking in Germany. Drawing on advanced object detection techniques applied to satellite imagery, the study maps current infrastructure and identifies regions of critical undersupply. The results provide actionable insights both for policymakers, who must address infrastructure bottlenecks as freight volumes rise, and for real estate developers, who can use these data-driven insights to identify high-demand investment opportunities.
Overall, this dissertation seeks to address contemporary policy debates in finance and real estate through independent, evidence-based analysis. Rather than advocating for either deregulation or overregulation, the findings underscore the importance of targeted re-regulation to foster positive economic and social outcomes. By doing so, the thesis contributes not only to academic discourse but also to practical policymaking, demonstrating the potential of empirical research to inform decisions of high societal relevance
Exploring Foot-Operated Input for Desktop Applications
No full textThere is a rich history of foot-operated machinery, ranging from treadmill-powered lathes to modern vehicles. Even though early HCI research explored general-purpose foot input, most modern day research on this topic focuses either on gesture-based interaction or very specific application scenarios. Today, working on a desktop or laptop computer relies almost exclusively on users’ hands, leaving their feet unoccupied. Therefore, we explore how foot-operated input devices can be incorporated in modern office workflows. We first gathered design requirements and use cases in multiple focus groups sessions. Based on our findings, we conducted a five-day diary study with twelve participants incorporating off-the-shelf footswitches with customizable functions into their usual workflows. Throughout the study, all participants continued to use the footswitches mainly for secondary tasks, such as controlling media playback or triggering shortcuts. We conclude that even simple foot-operated input devices with customizable functions can improve user experience and help users work more efficiently