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Long-Term Active Rather than Passive Restoration Promotes Soil Organic Carbon Accumulation by Alleviating Microbial Nitrogen Limitation in an Extremely Degraded Alpine Grassland
No full textGrassland degradation disrupts microbial nutrient cycling, yet the role of nitrogen (N) limitation in regulating soil organic carbon (SOC) dynamics during restoration remains poorly understood. Here, 10 years of active (sowing of seeds of native plants) and passive restoration (sand barrier protection) in degraded grasslands on the Qinghai–Tibetan Plateau are compared. Restoration impacts are assessed by integrating microbial metabolic traits such as stoichiometry-based nutrient limitation and C use efficiency (CUEST) with SOC fractionation, which considers both POC and MAOC). Active restoration reduces microbial N limitation by 44–71%, driving a 291–467% increase in SOC stocks, from 0.81 to 3.15 kg m−2 in topsoil and 0.54 to 3.08 kg m−2 in subsoil. It also reduces CUEST by 54% in topsoil and 34% in subsoil, boosting POC by 483–557% and MAOC by 621–1,071%. MAOC dominates SOC accumulation, exceeding POC by 2.3–7.2 times. The CUEST reduction aids POC transformation into MAOC, stabilizing SOC storage. In contrast, passive restoration slightly reduces N limitation by 36–39% and CUEST by 10–23%, but failed to enhance C fractions or SOC stocks due to persistent nutrient constraints. The findings demonstrate that alleviating microbial N limitation by active restoration is critical for stabilizing SOC through MAOC accumulation
Social identity and capital income: A social psychological approach to identity economics using UK household data
No full textSocial identity research has yet to fully engage with identity economics. This article bridges the two by examining capital market participation and capital income inequality – a critical economic behaviour and a societal issue that remain understudied in social psychology. We integrate psychological concepts and metrics of social identity with large-scale, representative UK data on household economics, encompassing 60,156 individuals and 130,598 observations from 2010 to 2023. Examining gender, ethnicity, education, occupation, politics, age and family as aspects of individuals' self-concept, our findings show that between- and within-person variations in these identities, beyond mere group memberships, were uniquely associated with both the presence and amount of capital income. Rather than reinforcing group membership effects, which could suggest adherence to group norms around capital market participation, our results highlight the importance of identity domains. Gender and ethnic identity were associated with lower capital income, whereas educational and political identity were linked to higher capital income. These patterns persisted across different groups and income strata. Importantly, the predictive power of social identities was comparable to traditional sociodemographic variables. This study extends social identity research to understudied economic behaviours and contributes to the emerging fields of identity economics and the psychology of inequality
Lethal effect of heterologous Haemonchus contortus α- and β-tubulin expression in Leishmania tarentolae
No full textBenzimidazoles are widely used anthelmintics that target β-tubulin and disrupt microtubule formation, yet the precise mode of action and resistance mechanisms in parasitic nematodes remains incompletely understood. To investigate the processes, heterologous expression of Haemonchus contortus isotype-1 α-tubulin and isotype-1 β-tubulin linked to the selection markers nourseothricin and hygromycin, respectively, was attempted following integration into Leishmania tarentolae ssu(18S) loci. Transcription of both tubulin genes was confirmed by RT-PCR two days post-transfection. However, transgenic L. tarentolae failed to recover or enter exponential growth under antibiotic selection. In contrast, control constructs containing scrambled open reading frame integrated successfully and yielded viable and proliferating lines expressing the corresponding mRNAs. These findings indicate that translation of functional H. contortus tubulins is toxic to L. tarentolae, likely due to incompatibility with native tubulins and disruption of the native microtubule network, resulting in loss of motility and cell death. The study provides experimental evidence that cross-species tubulin expression can be lethal due to cytoskeletal interference, underscoring the functional specificity of tubulin subunits. This incompatibility represents a barrier to heterologous tubulin expression and suggests that controlled or inducible eukaryotic expression systems may be necessary for the functional production of nematode tubulins
The dorsal aortic compartment is a developmental source of brown adipose tissue in mice
No full textWhite adipose tissue primarily stores energy while brown adipose tissue dissipates energy as heat, holding promise for therapeutic use. Brown adipose tissue in the anterior trunk is believed to derive from the somitic mesoderm, although some depots are of partially unknown origin. Here we show that the subscapular, lateral, cervical and peri-aortic brown adipose depots, but not the interscapular depot, are in part formed by a non-somitic source. Single-cell sequencing along with genetic lineage tracing indicates that at embryonic day 9.5 the dorsal aorta compartment harbors multipotent mesenchymal progenitors expressing the transcription factor Osr1. Spreading laterally from the dorsal aortic midline, these cells contribute to adipose, cartilage and myogenic lineages. This study uncovers an alternative source of brown adipose tissue and suggests that a fraction of dorsal aorta-associated mesenchymal Osr1 + cells may represent the in vivo correlate of a multipotent progenitor cell type so far only characterized in vitro, the mesoangioblast
Atmospheric Deposition of Local Mineral Dust Delivers Phosphorus to the Greenland Ice Sheet
No full textAerosol composition, size, and deposition rate determine the impact these particles have on cryosphere environments. Mineralogical, biological, and geochemical characteristics of aerosols collected over two years from the southwest Greenland Ice Sheet indicate that aerosols delivered via dry deposition and in snow primarily consisted of silicate minerals, with mean particle diameters of 1.01 ± 1.58 μm (2016) and 0.76 ± 0.87 μm (2017) for dry deposition and 2.4 ± 3.2 μm for dust delivered in snow (2017). The rare earth element signature of the delivered dust was typical of nearby Greenlandic lithologies, and combining this with other geochemical results and airmass history modeling indicated that the airborne mineral dust collected on-ice was likely from local emission sources, namely nearby proglacial plains. Dust and snow deposition rates were used to estimate phosphorus delivery to the ice surface at a rate of 1.2 mg·m–2·year–1, which could fuel estimated pigmented glacier ice algal cell abundances of 8.6 × 103 cells·mL–1, a value consistent with glacier ice algal bloom cell densities documented in the region. The eukaryotic communities in air and snow samples were dominated by algae and fungi, respectively, with both sample types also hosting various bacteria. These results suggest that the airborne transfer of glacier ice and snow algae may be a method by which fresh cryosphere surfaces become inoculated with these pigmented organisms. Collectively, these findings highlight the biogeochemical links between aerosols and the ice sheet surface, which have impacts on glacier ice algal growth and the corresponding surface ice albedo and melting
Cultural Interventions, Writing Climate, and a Burning Planet
No full textWho, or what, is the contemporary climatic subject? Addressing the climate crisis in thought, imagination, and in action requires a connection between scholars, artists, journalists, and activists. The contributors to this volume put such a cooperation into practice and present not only academic articles, but also interviews, short stories, poems, and political essays. Readers will encounter the ›climatic subject‹ as an entity and as a historical force. But they will also hear the ›climatic subject‹ posed as a question, a displacement of subjectivation under the condition of the climate crisis. Finally, they will find the ›climatic subject‹ as a connector for new subjectivities yet to be embodied in cultural practice
Development and validation of a multiclass LC-MS/MS method for the analysis of cyanotoxins
No full textCyanobacteria are prokaryotic organisms that can form large monospecific blooms, which pose a risk to human and animal health as some species produce toxic secondary metabolites called cyanotoxins. Multiclass cyanotoxin analysis is challenging due to varying chemical and physical properties between classes, as well as potentially large numbers of analogues within each class. Incorporating anatoxins (ATXs) into multiclass methods can be particularly challenging due to their small molecular size, potential interferences, polarity, and a lack of chemical standards for most analogues. Here, we present the development of a multiclass LC–MS/MS method and a quantitative calibration solution for aetokthonotoxin (AETX), an emerging cyanotoxin linked to mass mortalities of bald eagles in the Eastern United States. The developed method is capable of detecting 17 microcystins (MCs), nodularin-R, three cylindrospermopsins (CYNs), AETX, and 17 ATXs, including recently tentatively identified 10-hydroxy analogues. Analytes were identified by retention time and product ion ratio matching with available standards. The method was evaluated with respect to limits of detection (LODs), linear range, accuracy, and precision using neat and matrix matched standards. LODs in wet cyanobacterial biofilms ranged from 0.14 ng/g for CYN to 2.8 ng/g for [Dha7]MC-LR with accuracies ranging from 65% for [Leu1]MC-LY to 116% for CYN. Finally, the method’s application was demonstrated through analysis of cyanobacterial field samples, a dietary supplement matrix reference material, and passive sampler extracts to assess versatility within different matrices
Lung retention, distribution and persistence of polymer particles in rats exposed via inhalation
No full textBackground
Microplastics have been repeatedly detected in the human body, yet uncertainties surround their bioavailability and fate due to experimental challenges and limitations, especially regarding their nano-sized counterparts. Knowing that toxicokinetics information is essential for accurate risk assessment and management, this research aimed to (1) evaluate different sample preparation and quantification methods for nanoplastics particles in mammalian tissue, and (2) investigate the lung retention, bioavailability and fate of these particles.
Methods
In this study, rats inhaled aerosols with up to 50 mg/m 3 of Nile Red-labeled polystyrene (PS-NR) or unlabeled polyamide particles (PA-6) particles for 28 days. The tissues were analyzed for the presence of polymer particles. PS-NR were quantified in formalin-fixed tissue by confocal fluorescence laser microscopy with semi-automatic imaging analysis, and PA-6 particles were quantified in dried tissues by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS).
Results
PA-6 deposition was detected and quantified in lung and lymph nodes. Deposition of PS-NR was quantified in lungs and lung-draining lymph nodes, but no particles were detected in the liver, spleen, and kidneys. The lung burdens and translocation to the draining lymph nodes were similar for both particles, and particles were still detectable after the end of the exposure periods (five weeks for PS-NR and 13 weeks for PA-6).
Conclusions
This work highlights limitations and applicability of the various methods for sample preparation, detecting and quantifying polymer particles in mammalian tissues. In addition, it provides reliable data on the internal dose of inhaled polymer particles
Geometry of chiral temporal structures. II. The formalism
No full textWe develop a mathematical formalism underlying the emergence of enantiosensitive molecular orientation due to photoionization or photoexitation of chiral molecules. We consider geometric quantities such as the Berry connection and Berry curvature in light-driven chiral electronic states in the space of complex light polarization vectors. The parametric dependence of the light-driven electronic wave function on such vectors is based on various possible mutual orientations between the laser field and a chiral molecule. Using the tools of differential geometry, we show how the enantiosensitive observables arise from the geometry of the molecular response in such spaces
Antimicrobial resistance genes in weaned pigs: quantitative abundance and group dynamics assessed by qPCR
No full textAntibiotic resistance genes (ARGs) linked with the selection of resistant bacteria in intensive commercial livestock production require regular surveillance. This study quantified ARG abundances in weaner pigs, with emphasis on inter-individual variation and temporal trends of ARG dynamics over 8 weeks in a flat-deck housing system. Fecal samples from 103 individual pigs and 53 pooled pen-floor collections were analyzed. Broad-spectrum ARG profiling of pooled DNA from both sample types was performed using high-throughput qPCR (SmartChip), while standard qPCR quantified eight ARGs (aadA1, blaTEM, dfrA12, erm(B), lnu(F), qnrS, sul2, and tet(A)) and the 16S rRNA gene in all samples. Among the quantified ARGs, erm(B) and aadA1 were the most abundant, while qnrS was least frequently detected. Substantial inter-individual variation was observed for most ARGs, despite pigs living together under the same management conditions. Pooled pen-floor feces exhibited significantly higher ARG loads than individual fecal samples, suggesting that resistome profiles at the pen-floor level cannot be accurately inferred from fresh feces of individual animals. Temporal analysis revealed that 16S rRNA gene copies increased during the later period, while tet(A) and sul2 decreased, suggesting age-related effects. These findings reveal pronounced intra-cohort variability in ARG abundance among weaner pigs and underscore the impact of weaning-associated factors on resistome composition. Future investigations should examine the contribution of gut microbiome dynamics and evaluate dietary interventions aimed at stabilizing ARG profiles and mitigating the resistance development of microbial resistance