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Collective Nuclear Excitation and Pulse Propagation in Single-Mode X-Ray Waveguides
No full textWaveguides offer a means to controllably couple atomic ensembles to the electromagnetic field therein. Here, we demonstrate x-ray propagation in planar thin-film waveguides coupled to Mössbauer nuclei under collective resonant excitation by short pulses of synchrotron radiation. We record x-ray photons that have been emitted into resonant modes of the waveguide. Depending on the geometry and mode of excitation, two fundamentally different signatures of the collective emission are observed, for which we present a unifying theoretical model. Our results form a new platform for waveguide quantum electrodynamics in the hard x-ray regime with the potential to provide a coherent narrow band source of x-rays on the nanometer scale.Max Planck School of Photonics http://dx.doi.org/10.13039/501100022731Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/50110000165
Nitrogen Availability Governs Priming Effect Induced by Biodegradable Microplastics Through Microbial Life‐Strategies
No full textABSTRACT Microplastics (MPs) have emerged as an increasingly concerning soil contaminant. Although biodegradable plastics are good alternatives to non‐biodegradable plastics in croplands, they can influence soil organic matter (SOM) decomposition through a priming effect. We investigated how the biodegradable MPs‐induced priming effect responds to nitrogen (N) availability in soil. The impact of biodegradable MPs and mineral N on the priming effect was generalized by a meta‐analysis, and the mechanisms were investigated by 13 C isotope techniques coupled with 16S rRNA amplicon sequencing. By combining the meta‐analysis of data from 67 publications with an incubation experiment, we tested the MPs‐induced priming effect and their mechanisms depending on four levels of mineral N: 1.50, 0.75, 0.50, 0.30 mg N g −1 soil. The meta‐analysis suggested that the mineral N input decreased the priming effect induced by root exudates (effects size: −1.1) and MPs (effects size: −1.5), but increased the priming effect induced by biochar (effects size: 3.1). The effect size of mineral N input on the priming effect decreased with the increase of carbon‐to‐nitrogen ratio (C/N) between added organic carbon and mineral N. Due to the differences in MPs degradability, the range of the priming effects induced by polyhydroxyalkanoate was from 200% to 250%, while the priming effects induced by polylactic acid were negative (−22% to −5%). Mineral N primarily mitigated the MPs‐induced priming effect by reducing the abundances of microorganisms with K‐strategy (Acidobacteria and Basidiomycota), thereby reducing their N mining from SOM. Priming reduction by N fertilization was minimal when the C/N between added MPs carbon and mineral N was 10 (high N availability), and the abundance of r ‐strategists (Proteobacteria and Ascomycota) was large. We conclude that both r ‐ and K‐strategists collectively drive the intensity and direction of the MPs‐induced priming effect, which decreases with increasing C/N between added MPs carbon and mineral N.National Natural Science Foundation of China https://doi.org/10.13039/501100001809National Key Research and Development Program of China https://doi.org/10.13039/501100012166Russian Science Foundation https://doi.org/10.13039/50110000676
Potential impact of climate change on the reproductive success of grayling ( Thymallus thymallus )
No full textAbstract The European grayling is a salmonid species experiencing a sharp population decline, and conservation measures have been initiated through artificial propagation. As the species is not commonly cultivated in aquaculture, there is little information on their optimal reproduction conditions. Therefore, this study has combined a two‐pronged approach of examining the temperature of the natural spawning area during the spawning season, while also experimentally testing four different incubation temperatures under standardized aquaculture conditions. Nine egg clutches from pond‐reared females were fertilized with a sperm mix from 10 wild grayling. Eggs were divided into four treatment groups and incubated at 6, 8, 10 and 12°C. Hatched larvae were then collected and examined for body weight, yolk‐sac weight and length. Both the temperature of the natural habitat and the physiological parameters of the larvae indicate that 6 and 8°C are the optimal hatching temperatures for grayling reproduction. The hatching rate was highest at 8 and 6°C, at 80.35 ± 6.30% and 76.87 ± 8.01%, respectively, although it gradually decreased with increasing temperature. The impact of warmer water temperatures hindered survival rates, resulting in a significant decrease in hatching rates at 10°C (68.46 ± 13.85%) and 12°C (45.54 ± 27.14%)
Small pangenome of Candida parapsilosis reflects overall low intraspecific diversity
No full textABSTRACT Candida parapsilosis is an opportunistic yeast pathogen that can cause life-threatening infections in immunocompromised humans. Whole-genome sequencing studies of the species have demonstrated remarkably low diversity, with strains typically differing by about 1.5 single nucleotide polymorphisms (SNPs) per 10 kb. However, SNP calling alone does not capture the full extent of genetic variation. Here, we define the pangenome of 372 C . parapsilosis isolates to determine variation in gene content. The pangenome consists of 5,859 genes, of which 48 are not found in the genome of the reference strain. This includes 5,791 core genes (present in ≥99.5% of isolates). Four genes, including the allantoin permease gene DAL4 , were present in all isolates but were truncated in some strains. The truncated DAL4 was classified as a pseudogene in the reference strain CDC317. CRISPR-Cas9 gene editing showed that removing the early stop codon (producing the full-length Dal4 protein) is associated with improved use of allantoin as a sole nitrogen source. We find that the accessory genome of C. parapsilosis consists of 68 homologous clusters. This includes 38 previously annotated genes, 27 novel paralogs of previously annotated genes, and 3 uncharacterized open reading frames. Approximately one-third of the accessory genome (24/68 genes) is associated with gene fusions between tandem genes in the major facilitator superfamily. Additionally, we identified two highly divergent C. parapsilosis strains and found that, despite their increased phylogenetic distance (~30 SNPs per 10 kb), both strains have similar gene content to the other 372. IMPORTANCE Candida parapsilosis is a human fungal pathogen listed in the high-priority group by the World Health Organization. It is an increasing cause of hospital-acquired and drug-resistant infections. Here, we studied the genetic diversity of 372 C . parapsilosis isolates, the largest genomic surveillance of this species to date. We show that there is relatively little genetic variation. However, we identified two more distantly related isolates from Germany, suggesting that even more sampling may yield more diversity. We find that the pangenome (the cumulative gene content of all isolates) is surprisingly small, compared to other fungal species. Many of the non-core genes are involved in transport. We also find that variations in gene content are associated with nitrogen metabolism, which may contribute to the virulence characteristics of this species.Candida parapsilosis is a human fungal pathogen listed in the high-priority group by the World Health Organization. It is an increasing cause of hospital-acquired and drug-resistant infections. Here, we studied the genetic diversity of 372 C . parapsilosis isolates, the largest genomic surveillance of this species to date. We show that there is relatively little genetic variation. However, we identified two more distantly related isolates from Germany, suggesting that even more sampling may yield more diversity. We find that the pangenome (the cumulative gene content of all isolates) is surprisingly small, compared to other fungal species. Many of the non-core genes are involved in transport. We also find that variations in gene content are associated with nitrogen metabolism, which may contribute to the virulence characteristics of this species.ABSTRACT Candida parapsilosis is an opportunistic yeast pathogen that can cause life-threatening infections in immunocompromised humans. Whole-genome sequencing studies of the species have demonstrated remarkably low diversity, with strains typically differing by about 1.5 single nucleotide polymorphisms (SNPs) per 10 kb. However, SNP calling alone does not capture the full extent of genetic variation. Here, we define the pangenome of 372 C . parapsilosis isolates to determine variation in gene content. The pangenome consists of 5,859 genes, of which 48 are not found in the genome of the reference strain. This includes 5,791 core genes (present in ≥99.5% of isolates). Four genes, including the allantoin permease gene DAL4 , were present in all isolates but were truncated in some strains. The truncated DAL4 was classified as a pseudogene in the reference strain CDC317. CRISPR-Cas9 gene editing showed that removing the early stop codon (producing the full-length Dal4 protein) is associated with improved use of allantoin as a sole nitrogen source. We find that the accessory genome of C. parapsilosis consists of 68 homologous clusters. This includes 38 previously annotated genes, 27 novel paralogs of previously annotated genes, and 3 uncharacterized open reading frames. Approximately one-third of the accessory genome (24/68 genes) is associated with gene fusions between tandem genes in the major facilitator superfamily. Additionally, we identified two highly divergent C. parapsilosis strains and found that, despite their increased phylogenetic distance (~30 SNPs per 10 kb), both strains have similar gene content to the other 372. IMPORTANCE Candida parapsilosis is a human fungal pathogen listed in the high-priority group by the World Health Organization. It is an increasing cause of hospital-acquired and drug-resistant infections. Here, we studied the genetic diversity of 372 C . parapsilosis isolates, the largest genomic surveillance of this species to date. We show that there is relatively little genetic variation. However, we identified two more distantly related isolates from Germany, suggesting that even more sampling may yield more diversity. We find that the pangenome (the cumulative gene content of all isolates) is surprisingly small, compared to other fungal species. Many of the non-core genes are involved in transport. We also find that variations in gene content are associated with nitrogen metabolism, which may contribute to the virulence characteristics of this species.Candida parapsilosis is a human fungal pathogen listed in the high-priority group by the World Health Organization. It is an increasing cause of hospital-acquired and drug-resistant infections. Here, we studied the genetic diversity of 372 C . parapsilosis isolates, the largest genomic surveillance of this species to date. We show that there is relatively little genetic variation. However, we identified two more distantly related isolates from Germany, suggesting that even more sampling may yield more diversity. We find that the pangenome (the cumulative gene content of all isolates) is surprisingly small, compared to other fungal species. Many of the non-core genes are involved in transport. We also find that variations in gene content are associated with nitrogen metabolism, which may contribute to the virulence characteristics of this species.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Science Foundation Ireland http://dx.doi.org/10.13039/501100001602Irish Research Council for Science, Engineering and Technology http://dx.doi.org/10.13039/501100001596Science Foundation Ireland http://dx.doi.org/10.13039/501100001602European Research Council http://dx.doi.org/10.13039/501100000781Science Foundation Ireland http://dx.doi.org/10.13039/501100001602Irish Research Council http://dx.doi.org/10.13039/501100002081National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809EC | FP7 | People | FP7 People: Marie-Curie Action
Protein Storage in Oocytes: Implications for Oocyte Quality, Embryonic Development, and Female Fertility
No full textMaternal storage is a fundamental feature of female gametes and is essential for maintaining oocyte quality and preserving developmental competence. Embryonic development relies on maternally deposited proteins, transcripts, and nutrients, yet the mechanisms by which oocytes accumulate and store these critical factors—particularly proteins—remain poorly understood. Across eukaryotes, diverse protein storage strategies have evolved, reflecting both conserved and species-specific adaptations. Here, we review the mechanisms of oocyte protein storage, comparing different species to uncover functional similarities and differences. Additionally, germ cells must clear damaged molecules accumulated during the mother's lifetime to ensure the production of rejuvenated eggs. We examine the conserved proteostasis mechanisms that support this process. By integrating insights from various model organisms and cellular dormancy studies, this review highlights the molecular basis of oocyte protein storage and its vital role in reproductive success
Three-Year Outcomes After Temperature-Controlled Radiofrequency Ablation of the Posterior Nasal Nerve for Chronic Rhinitis
No full textBackground Chronic rhinitis (CR) is characterized by refractory symptoms such as rhinorrhea, sneezing, nasal congestion, postnasal drip (PND), and cough. Most patients do not achieve lasting symptom relief with medical management. Objective To evaluate the long-term efficacy and safety of temperature-controlled radiofrequency treatment targeting posterior nasal nerves (PNNs) for CR. Methods This prospective, single-arm, open-label, multicenter study included patients aged 18–85 years across 19 centers in the United States and Germany. Outcome measures included reflective Total Nasal Symptom Score (rTNSS), PND and cough scores, and the Mini Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ). Outcomes, including adverse events, were reported through 3 years post-procedure. Setting All procedures were performed in an outpatient office-based setting. Results One hundred twenty-nine patients received treatment; 101 completed 3-year follow-up. The adjusted mean rTNSS Score improved from 7.8 (95% confidence interval [CI]: 7.5-8.1) at baseline to 3.2 (95% CI: 2.8-3.7) at 3 years (mean change: −4.5 [95% CI: −5.1 to −4.0]; P < .001). Rhinorrhea symptom scores improved from 2.6 to 1.2 (55.8% reduction). Compared to baseline, at 3 years, adjusted mean cough and PND scores declined from 1.3 to 0.4 (mean change: −0.9; P < .001, 69% reduction) and from 2.4 to 1.2 (mean change: −1.2; P < .001, 50% reduction), respectively. MiniRQLQ scores were significantly reduced from an adjusted mean of 3.0 (95% CI: 2.8-3.2) at baseline to 1.2 (95% CI: 1.0-1. 4) at 3-year follow-up; P < .001. No serious device- or procedure-related adverse events were reported. Conclusion A single temperature-controlled radiofrequency treatment of the PNN safely and effectively reduced CR symptoms, including cough and PND, improved quality of life, and decreased medication burden through a period of 3 years with no serious adverse events
Subjective theories of teacher trainers as to how to initiate argumentation and proving processes for geometry in lower secondary school classrooms
No full textTwo experienced mathematics teacher trainers are interviewed to assess the possibilities of proof
activities in lower secondary schools that work in everyday school life. The subjective theories of the
teacher trainers on how to make the classical proofs of the sum of angles in triangles and the
Pythagorean theorem accessible to all are investigated within the research programme of individual
curricula. It is striking that their choices of proof procedures are strongly influenced by
heterogeneous classroom situations
An Empirical Study Using Natural Language Processing
No full textIn Germany a centralized common pool of mathematics tasks has been implemented
for the final high school exam, the Abitur. Contextualized tasks form a significant part
of that pool. Here we examine the familiarity of the vocabulary used as well as the level
of syntactic complexity. The tasks are grouped by subject area, course level, level of
demand and text function (informative or instructive). Natural Language Processing
is used for the linguistic analysis. Differences between task groups are described and
the implications for their lexicosyntactic complexity are discussed
