Search Results (377)

Acanthamoeba, a free-living amoeba ubiquitous in environmental water, has been considered as the environmental reservoir of certain bacterial pathogens, including Campylobacter jejuni, an intracellular human pathogen causing self-limiting gastroenteritis. Acanthamoeba-C. jejuni interaction mechanisms may help clarify how the otherwise fastidious bacterium C. jejuni survives in environmental waters. In this study, we constructed single deletion mutants of C. jejuni strain 81–176 for the 10 selected genes (motAB, ciaB, kpsE, virB11, cheY, flaAB, cstII, docB, sodB, and cadF) previously shown to be important for the interaction (invasion and intracellular survival) of C. jejuni with mammalian hosts. We used a modified gentamicin protection assay to quantify the internalization and intracellular survival of these mutants and the wild type with the two species of Acanthamoeba (A. castellanii and A. polyphaga). Both internalization and intracellular survival were significantly lower for all mutants compared to the wild type with both amoeba strains, except for ΔcstII in the internalization assay with A. castellanii (p < 0.05). The results of this study highlight that the mechanisms used by C. jejuni to interact with mammalian hosts are conserved in its interactions with amoeba hosts. This understanding may be useful in developing effective strategies to reduce the transmission of C. jejuni to chickens through drinking water. Full article

Background/Objectives: Psychological vulnerability in individuals with obesity represents a significant concern in the context of bariatric surgery. This study aimed to assess psychosocial functioning and identify the psychological, clinical, and sociodemographic predictors of impairment among patients undergoing preoperative evaluation. Methods: A retrospective observational study was conducted on patients referred for bariatric surgery at a single academic medical center. Data were collected through clinical interviews and validated psychometric tools: the Clinical Impairment Assessment (CIA), the Patient Health Questionnaire-9 (PHQ-9), and the Generalized Anxiety Disorder-7 (GAD-7). Robust multiple regression analysis determined associations between CIA scores and psychological and demographic factors. Results: A total of 688 patients were evaluated (median age: 46 years; 70.3% female). Most had a high school education (56.9%) and were employed (69%). Elevated scores on the Clinical Impairment Assessment (CIA) were significantly associated with female gender (β = 1.075, p = 0.029), moderate anxiety (GAD-7 ≥ 10; β = 3.85, p < 0.001), and severe depressive symptoms (PHQ-9 ≥ 15; β = 16.67, p < 0.001). Other significant predictors included prior psychotherapy (β = 1.18, p = 0.044), aesthetic motivation for surgery (β = 0.92, p = 0.120), and expectations that weight loss would improve self-esteem (β = 2.11, p = 0.001) or social relationships (β = 1.98, p = 0.002). Conversely, physical activity was associated with lower CIA scores (β = –1.23, p = 0.050). The regression model showed strong explanatory power (McFadden R² = 0.529). Conclusions: This study highlights key predictors of psychosocial distress in bariatric candidates, underscoring the importance of comprehensive psychological assessment before surgery. The CIA appears to be a valuable screening and monitoring tool. Future research should explore the longitudinal evolution of psychosocial functioning and support the integration of psychological care into multidisciplinary bariatric programs. Full article

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disorder whose precise etiology remains unclear, though growing evidence implicates gut microbiota in its pathogenesis. This study aimed to investigate the role of gut microbiota in the onset and progression of RA by employing fecal microbiota transplantation (FMT) in a collagen-induced arthritis (CIA) mouse model using DBA/1J and Aire⁻/⁻ strains. Mice received FMT from healthy donors, treatment-naïve RA patients, or treated RA patients in relapse, followed by assessment of microbiota composition via 16S rRNA sequencing, arthritis severity scoring, histological evaluations, and systemic inflammatory markers. The findings revealed distinct microbiota clustering patterns post-FMT across experimental groups, highlighting strain-specific colonization effects. Notably, genera such as Bifidobacterium and Paraprevotella correlated positively with arthritis severity in DBA/1J mice, whereas Corynebacterium, Enterorhabdus, and Odoribacter exhibited negative correlations, suggesting potential protective roles. Despite these microbial differences, minor variations in arthritis scores, paw inflammation, or systemic inflammation were observed among FMT groups. This indicates that although gut microbiota alterations are associated with RA pathogenesis, further investigation with larger cohorts and comprehensive sequencing approaches is essential to elucidate the therapeutic potential of microbiome modulation in autoimmune diseases. Full article

This study focuses on the upper section of the Zhujiang Formation in the Enping Sag of the Zhujiangkou Basin in the South China Sea, investigating the mechanisms by which astronomical orbital cycles drive paleoclimate, sea-level fluctuations, and sedimentary development. In this study, a cyclic stratigraphic analysis was performed using natural gamma-ray logging data and geochemical proxies (Chemical Index of Alteration (CIA); Al₂O₃ content) in combination with depositional noise modeling (DYNOT Dynamic Orbital Tuning Model and ρ1 noise factor). High-resolution time series analysis revealed three key findings: (1) a 15.98–19.09 Ma astronomical timescale was established through the identification of Milankovitch cycles including 405 kyr eccentricity, 100 kyr eccentricity, 40 kyr obliquity, and 20 kyr precession; (2) sea-level changes exhibited 405 kyr eccentricity-driven cyclicity, with high-eccentricity phases corresponding to warm-humid climates and transgressive mudstone deposition, and low-eccentricity phases reflecting arid conditions and regressive sandstone development; and (3) orbital-scale precession modulation regulated sediment source-to-sink processes through climate–sea level coupling. This work provides a quantitative framework for predicting astronomical cycle-controlled reservoirs, offering critical insights for deepwater hydrocarbon exploration in the Zhujiangkou Basin. Full article

Background: Verticillium wilt, which is a soil-borne vascular disease, causes serious economic losses worldwide. Various toxins secreted by V. dahliae are key factors that lead to wilt symptoms. Methods: The Vd-toxins CIA, indazole, and 3ICD were labeled with fluorescence groups, respectively, to observe the transport pathway. Transcriptome sequencing and qRT-PCR were employed to assess the expression patterns under Vd-toxin treatment. Results: AtALA1 and AtALA7 were up-regulated by V. dahliae and LC-toxins, and overexpression of either AtALA1 or AtALA7 increased Arabidopsis resistance against LC-toxins. Overexpression of AtALA1 improved the resistance of Arabidopsis to 4MBA, 3ICD, and indazole, while AtALA7 enhanced resistance to 4MBA, 3ICD, and CIA. AtALA7-overexpressing plants showed a stronger capability to transport CIA^FITC and 3ICD^5-FAM into vacuoles, while AtALA1-overexpressing plants accumulated indazole^5-FAM and 3ICD^5-FAM. Aggregation of AtALA1 and AtALA7 enhances the resistance of plants to V. dahliae. Conclusions: Arabidopsis P4-ATPase genes AtALA1 and AtALA7 mediated cell detoxification by transporting different Vd-toxins to vacuoles for degradation, thereby increasing resistance to Verticillium wilt. Full article

Recently, significant effort has been devoted to enhancing magnetic anisotropy energy (MAE) and the Dzyaloshinskii–Moriya interaction (DMI) in two-dimensional (2D) ferromagnetic materials through various tuning approaches. Among these methods, defect engineering is one of the most effective strategies. However, the influence of these charged defects on the MAE and DMI is unclear. Therefore, we systematically investigate the defect effect on the MAE and DMI of I vacancy-doped (v_I-CrI₃), 3d-transition-metal-doped (TM = Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) (3d-TM_i@CrI₃), and v_I-TM co-doped (3d-TM_i@v_I-CrI₃) monolayer CrI₃ using first-principles calculations. Our results indicate that Cr-rich conditions can promote the defect formation of v_I-CrI₃, 3d-TM_i@CrI₃, and 3d-TM_i@v_I-CrI₃ systems and demonstrate that 49 types of charged systems are stable. Among these systems, the Cu_i@v_I-CrI₃ in the +1 charge state (Cu_i^•@v_I-CrI₃) system has a smaller defect formation energy, exhibiting a large MAE exceeding 30 meV, and the ratio (D/J) of the antisymmetric magnetic exchange parameter (D) to the Heisenberg exchange parameter (J) reaches 1.04. The large MAE originates from the transition from single-ion anisotropy (SIA) to covalent interaction anisotropy (CIA) due to the coupling variation between the p_y and p_x orbitals of I atoms near the Fermi level caused by charge states. The enhancement of the DMI is due to the electrostatic potential differences between the I-top and I-bottom layers, which are conducive to forming stable chiral spin textures. This study provides insight into the defect charge state modulating the magnetism of 2D magnetic materials. Full article

High levels of stigma among the healthcare workforce impede efforts to increase access to effective substance use disorder (SUD) treatments. Education on SUDs that (1) is tailored to physicians in training and (2) directly addresses and attempts to combat SUD stigma may help produce lasting reductions in SUD stigmatization within the healthcare setting. This study aims to describe the development of a technology-based, interactive SUD stigma intervention for medical students, created in collaboration with medical students, practicing clinicians, and experts in the fields of psychology and addiction medicine. This intervention is unique in its interactive application-based approach and the use of a computerized intervention authorizing system (CIAS) to guide the participant through the training. The final intervention includes four interactive online modules focused on SUD education using a biopsychosocial model, including stigma acknowledgment, an examination of patient perspectives, and the application of skills. Planned future studies will examine the feasibility, acceptability, and preliminary efficacy of the intervention among medical students. This intervention leverages the existing CIAS to provide interactive training that can be used as a part of medical student training and be expanded to other healthcare professionals (e.g., nurses and community health workers). Ultimately, this work will be used to drive a reduction in SUD stigma in medical settings. Full article

The increased use of electronic devices in the Internet of Things (IoT) leads not only to an improved comfort of living but also to an increased risk of attacks. IoT security has thus become an important research field. However, due to limits on performance and bandwidth, IoT devices are often not powerful enough to execute, e.g., costly cryptographic algorithms or protocols. This limitation can be solved through a delegation concept. By delegating certain operations to devices with sufficient resources, it is possible to achieve a high level of security without overloading a device that needs protection. In this paper, we give an overview of current approaches for security delegation in the context of IoT, formalise security notions, discuss the security of existing approaches, and identify further research questions. Furthermore, a mathematical formalisation of the CIA triad (confidentiality, integrity, and availability) is proposed for the predefined application areas, in order to evaluate the different approaches. Full article

Understanding the climate–weathering coupling mechanisms remains pivotal for interpreting global glacial–interglacial cycles, yet advancements have been constrained by the limited high-resolution sedimentary archives. The newly acquired BXZK2017-2 borehole (30.5 m core) from Bohai Bay provides an exceptional sedimentary sequence to investigate the Late Quaternary climate–weathering interactions. Through an integrated high-resolution chronostratigraphic framework (AMS ¹⁴C and OSL dating) coupled with multi-proxy sedimentological analyses (major element geochemistry and granulometric parameters), we reconstructed the chemical–weathering dynamics in the Bohai coastal region since the Late Pleistocene. Our findings revealed four distinct climate-weathering phases that correlate with the regional paleoenvironmental evolution and global climate perturbations: (1) enhanced weathering during mid-MIS3 to ~37.5 cal kyr BP (Chemical Index of Alteration (CIA): 55.9–62.2), corresponding to regional warming and strengthened summer monsoon circulation; (2) weathering minimum in late MIS3 through early–mid-MIS2 (37.5–14.8 cal kyr BP, CIA < 55), marking the peak aridity before the Last Glacial Maximum; (3) maximum weathering intensity from mid-MIS2 to early MIS1 (14.8–3.34 cal kyr BP, CIA: 65–68), documenting the postglacial humidification driven by the intensified East Asian Summer Monsoon; (4) renewed weathering decline during the Neoglacial (3.34 cal kyr BP-present, CIA: 59–63), coinciding with the late Holocene cooling events. Remarkably, this study identifies a striking synchronicity between the CIA in marine drill cores and δ¹⁸O records derived from Greenland ice cores. Our results indicate that chemical weathering proxies from marginal sea sediments can serve as robust recorders of post-Late Pleistocene climate variability, establishing a new proxy framework for global paleoclimate comparative research. Full article

A variety of variables, such as organic matter input, redox conditions, depositional rates, and terrigenous input, affect the deposition of black shale. Furthermore, because of the significant regional variations in paleodepositional environments, these factors have a complex role in organic matter enrichment. Global geological events influenced sedimentary conditions, organic enrichment, and the development of organic-enriched shales during the Late Ordovician to Early Silurian. The Wufeng–Longmaxi Formation black shales in Southeastern Chongqing were analyzed for X-ray diffraction (XRD), major and trace element geochemistry, and total organic carbon (TOC) data; this led to further analysis of the relationship between the depositional environment and organic matter aggregation and rock type evolution. The primary minerals found in the Wufeng–Longmaxi shale are quartz, feldspar, carbonatite (calcite and dolomite), and clay. The high index of compositional variability (ICV) values (>1) and the comparatively low chemical index of alteration (CIA) values (52.6–72.8) suggest that the sediment source rocks are juvenile and are probably experiencing weak to moderate chemical weathering. The selected samples all show negative Eu anomalies, flat heavy rare earth elements, and mildly enriched light rare earth elements. The ratios of La/Th, La/Sc, Th/Sc, ΣREE-La/Yb, TiO₂-Ni, and La/Th-Hf suggest that acidic igneous rocks were the main source of sediment, with minor inputs from ancient sedimentary rocks. The correlations of paleoclimate proxies (Sr/Cu, CIA), redox proxies (V/Cr, V/Ni, V/(V + Ni), Ni/Co, U/Th), paleoproductivity proxies (Ba_xs, Cu_EF, Ni_EF), and water mass restriction proxies (Mo/TOC, U_EF, Mo_EF) suggest a humid–semiarid, anoxic, moderate–high paleoproductivity, and moderate–strongly restricted environment. On the basis of the aforementioned interpretations, the paleoenvironment of the Wufeng–Longmaxi Formations was established, with paleoredox conditions and restricted water masses likely being the primary factors contributing to organic matter enrichment. Full article

Background: According to the One Health concept, the physical proximity between pets and their owners facilitates the interspecies spread of bacteria including those that may harbor numerous antimicrobial resistance genes (ARGs). Methods: A shotgun sequencing metagenomic data-based bacteriome and resistome study of 1830 canine saliva samples was conducted considering the subsets of ARGs with higher public health risk, ESKAPE pathogen relatedness (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species), and survey results on the physical and behavioral characteristics of the participating dogs. Results: A total of 318 ARG types achieved sufficiently high detection rates. These ARGs can affect 31 antibiotic drug classes through various resistance mechanisms. ARGs against tetracyclines, cephalosporins, and, interestingly, peptides appeared in the highest number of samples. Other Critically Important Antimicrobials (CIAs, WHO), such as aminoglycosides, fluoroquinolones, or macrolides, were among the drug classes most frequently affected by ARGs of higher public health risk and ESKAPE pathogen-related ARGs of higher public health risk. Several characteristics, including coat color, sterilization status, size, activity, or aggressiveness, were associated with statistically significant differences in ARG occurrence rates (p < 0.0500). Conclusions: Although the oral microbiome of pet owners is unknown, the One Health and public health implications of the close human–pet bonds and the factors potentially underlying the increase in salivary ARG numbers should be considered, particularly in light of the presence of ARGs affecting critically important drugs for human medicine. Full article

RA is a chronic autoimmune disease characterized by synovial inflammation and joint damage, driven by autoantibodies such as ACPA, anti-CarP and RF. These autoantibodies, influenced by genetic and environmental factors, play a crucial role in RA pathogenesis through post-translational modifications like citrullination, carbamylation, and acetylation. The early detection of ACPA provides a potential window for intervention, while anti-CarP antibodies correlate with severe disease progression and RF aids in diagnosis. Translating these findings from human pathology to animal models presents significant challenges. Although the presence of adaptative immune cells (T cells) is well defined in animal models of RA, studies yield inconsistent results regarding autoantibody production and implication in the disease onset and progression, with varying detectability of ACPA, anti-CarP antibodies, and RF across different species and models. The collagen-induced arthritis (CIA) model shows PAD4 expression and citrullinated protein presence but inconsistent ACPA detection, while the K/BxN model elucidates the pathogenicity of anti-GPI autoantibodies and implicates Fcγ receptors in disease processes. Therefore, further research is needed to bridge the gap between animal models and human RA pathology. Future studies should focus on developing more representative animal models, exploring pharmacological targets and pathways that involve the interplay between anti-inflammatory and autoimmune responses, and investigating the complex interplay between genetic predisposition, environmental triggers, and autoimmune mechanisms. This approach may lead to improved early diagnostic tools, targeted therapies, and potentially preventive strategies for RA, ultimately enhancing patient outcomes and quality of life. Full article

This article proposes a conversation on the limits and possibilities of collectivizing the way in which we generate and inscribe knowledge within the terms of a political economy of knowledge production and circulation regulated by hierarchies of academic and non-academic classifications, as well as those that demarcate centres and peripheries domestically and internationally through racial–gendered distributions of authority. To this end, it explores a series of collective projects elaborated within the GlobalGRACE network in Brazil (Global Gender and Cultures of Equality), which experiment with residency methodologies designed to create the necessary infrastructure for a redistribution of power, knowledge, and authority in investigations on racial–gendered violence in the peripheries of Rio de Janeiro. As collaborators in this research–action project initiated in 2018 with the Observatory of Favelas of Rio de Janeiro, here, we mobilize two of these collective projects as case studies—the dance residency of Cia Passinho Carioca and the Free School of Arts ELÃ residency—so as to reflect on our ways of knowing and experiencing racial–gendered inequalities in context. In this way, it becomes possible to propose not only questions around the production, erasure, and appropriation of knowledge but also possibilities for the broad-based circulation of dissident knowledge practices and the subsequent displacement of established authorities in the field, notably by means of a disobjectification of subjects of knowledge and exercises in authoring in the first-person plural. This entry point into the conversation on who has the power to know and control the meanings of intersectional inequalities enables a focus on practice, pedagogy, and methods to unpack the ethical and epistemological questions at hand. By centring the problem of authorship, we argue that feminist and decolonial approaches to knowing, teaching, and learning need to effectuate redistributions of power and the construction of politico-epistemic infrastructure if we have any chance of cultivating the conditions needed for liberatory knowledge practices. Full article

The Cambrian period holds a crucial position in the history of life evolution. The Cambrian strata in the Yangtze Plate is a research hotspot in multiple disciplines and it of great significance for the study of the “Cambrian Explosion”. However, the research on the provenance and the degree of weathering of the sedimentary rocks in the Wulongqing (WLQ) Formation remains insufficient. This study focuses on the Cambrian WLQ Formation in the Yangtze Plate. A total of 26 samples, including sandstone and mudstone, were collected and analyzed using petrographic and geochemical analysis (including major elements, trace elements and rare earth elements) to constraint provenance and paleoweathering. The results show that SiO₂, Al₂O₃, and total Fe₂O₃ (Fe₂O₃T) are the main components. The average total concentration of rare earth elements is higher than the average value of the Upper Continental Crust. Through a variety of discrimination methods, such as the ratios of w(SiO₂)/w(Al₂O₃) and w(Al₂O₃)/w(TiO₂), the Zr–TiO₂ and Th/Sc–Zr/Sc diagrams, it is indicated that sedimentary rocks and felsic igneous rocks are the main provenances. The paleoweathering was evaluated by Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA). The CIA value ranges from 56.08 to 75.92, with average value 68.03, indicating a moderate chemical weathering. After correcting for the K metasomatism during diagenesis, the CIAcorr value indicates that deposition took place various climatic conditions ranging from warm and humid to hot and humid. The CIAcorr value indicated a moderate to strong chemical weathering. These findings provide critical geochemical evidence for deciphering the evolution of the Cambrian paleoenvironment. This study establishes connections to biological events through the disclosure of felsic provenance characteristics within the WLQ Formation and the interpretation of paleoclimatic shifts as evidenced by chemical weathering patterns. Full article

We investigated the effects of belt electrode-skeletal muscle electrical stimulation (B-SES) on muscle atrophy in collagen-induced arthritis (CIA) rats. Twenty-eight 8-week-old male Dark Agouti rats were immunized with type II collagen and Freund’s incomplete adjuvant (day 0). From days 14 to 28, 18 rats received B-SES (50 Hz) four times only on the right hindlimb (STIM), while the contralateral left hindlimb remained unstimulated. Both hindlimbs of 10 untreated CIA rats were defined as controls (CONT). Paw volume was measured every other day. On day 28, the muscle weight, histology, and gene expression of the soleus and extensor digitorum longus (EDL) were analyzed. B-SES did not worsen paw volume throughout the experimental period. Compared with CONT, the muscle weight and fiber cross-sectional area of the soleus were higher in STIM. The expression of muscle degradation markers (atrogin-1 and MuRF-1) in the soleus and EDL was lower in the STIM group than that in the CONT group. In contrast, B-SES did not significantly affect the expression of muscle synthesis (Eif4e and p70S6K) and mitochondrial (PGC-1α) markers. B-SES prevents muscle atrophy in CIA rats by reducing muscle degradation without exacerbating arthritis, demonstrating its promising potential as an intervention for RA-induced muscle atrophy. Full article