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Inbreeding reduces fitness in spatially structured populations of a threatened rattlesnake
No full textSmall and fragmented populations are at high risk of local extinction, in part because of elevated inbreeding and subsequent inbreeding depression. A major conservation priority is to identify the mechanisms and extent of inbreeding depression in small populations. The eastern massasauga (Sistrurus catenatus) rattlesnake is listed as Federally Threatened in the United States, having experienced significant habitat fragmentation and concomitant population declines over the past 200 years. Here, we use long-term monitoring of two wild populations of eastern massasaugas in Michigan to estimate the extent of inbreeding in each population, identify mechanisms that generate inbreeding, and test for the impact of inbreeding on fitness. Using targeted genomic data and spatial coordinates of capture locations from over 1000 individuals, we find evidence of inbreeding and link inbreeding to spatial kinship structure within populations, possibly driven by limited dispersal. We reconstruct multigenerational pedigrees for each population to measure reproductive output and use long-term capture-recapture data to estimate individual survival (i.e., the two major components of fitness). We find evidence of inbreeding depression in both fitness metrics. The 5% most inbred individuals are 13.5% less likely to have any surviving offspring and have 11.6% lower annual survival compared to all less inbred individuals. By combining genomics and long-term monitoring data, we are able to link the life history of eastern massasaugas to inbreeding and detect relationships between fitness and inbreeding. These insights provide important conservation context for future management and for understanding how spatial structure can generate inbreeding depression even at fine spatial scales.</p
Increasing the Lewis Acidity of Pyramidal Boranes:Cationic 9-Bora-1-Azatriptycenes as Strong Boron Lewis Superacids
No full textBora-azatriptycenes have been synthesized and used as geminal pyridine–boranes pairs, which exhibit unusual binding modes with weakly coordinating anions, to unique aza-triptycene/bora-triptycene Lewis adducts, and to bis-triptycenes dimers with unprecedented architectural motifs. Embedding a boron atom at the edge of a triptycene scaffold, in a strongly pyramidalized and geometrically constrained environment, and protonation of the adjacent pyridine ring strongly enhances the Lewis acidity of the boron atom. High levels of Lewis acidity are reached at the boron atom of these cationic boron Lewis superacids. Experimental and quantum-chemistry screening of their Lewis acidity enables elucidation of the interplay between Lewis acidity, pyramidalization angle, reorganization energy, and charge position in the adjacent pyridinium ring, and identifies new dicationic Lewis superacids
Exploring the Computational Complexity of Uniform Random Sampling and SAT Counting with Phase Transitions
No full textUniform Random Sampling (URS) and Model Counting (#SAT) are two intrinsically linked, theoretical problems with relevant practical applications in software engineering. In particular, in configurable system engineering, URS and #SAT can support studying configurations’ properties unbiasedly. Despite the community efforts to provide scalable URS and #SAT tools, solving these problems efficiently remains challenging for a large number of formulae. Contrary to the classical SAT problem, whose complexity has been an object of fundamental studies, little is known about what makes a formula hard to sample from. For the first time, we investigate how phase transitions can explain the practical complexity of sampling. Our results, computed on 11,409 synthetic formulae and 4656 real-world formulae, show that phase transitions occur in both cases, but at a different clause-to-variable ratio than for SAT tasks. We further reveal that low formula modularity is correlated with a higher URS/#SAT time. Overall, our work contributes to a principled understanding of URS and #SAT complexity
In vitro investigation of traditional medicine recipes used in Bukavu (DR-Congo) to treat Trichophyton rubrum dermatophytosis
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Correction to:Growth factor-triggered de-sialylation controls glycolipid-lectin-driven endocytosis (Nature Cell Biology, (2025), 27, 3, (449-463), 10.1038/s41556-025-01616-x)
No full textCorrection to: Nature Cell Biologyhttps://doi.org/10.1038/s41556-025-01616-x, published online 21 February 2025. In the version of the article initially published, the Agence Nationale pour la Recherche grant no. ANR-23-CE13-0033-01 was missing from the Acknowledgements section and has now been added to the HTML and PDF versions of the article.</p
The effect of prenatal balanced energy and protein supplementation on gestational weight gain:An individual participant data meta-analysis in low- and middle-income countries
No full textBackground AU Understanding: Please confirm that all heading levels are represented correctly the effects of balanced energy and protein (BEP): supplements on gestational weight gain (GWG) and how the effects differ depending on maternal characteristics and the nutritional composition of the supplements will inform the implementation of prenatal BEP interventions. Methods and findings Individual participant data from 11 randomized controlled trials of prenatal BEP supplements (N = 12,549, with 5,693 in the BEP arm and 6,856 in the comparison arm) in low- and middle-income countries were used. The primary outcomes included GWG adequacy (%) and the estimated total GWG at delivery as continuous outcomes, and severely inadequate (<70% adequacy), inadequate GWG (<90% adequacy), and excessive GWG (>125% adequacy) as binary outcomes; all variables were calculated based on the Institute of Medicine recommendations. Linear and log-binomial models were used to estimate study-specific mean differences or risk ratios (RRs), respectively, with 95% confidence intervals (CIs) of the effects of prenatal BEP on the GWG outcomes. The study-specific estimates were pooled using meta-analyses. Subgroup analyses were conducted by individual characteristics. Subgroup analyses and meta-regression were conducted for study-level characteristics. Compared to the comparison group, prenatal BEP led to a 6% greater GWG percent adequacy (95% CI: 2.18, 9.56; p = 0.002), a 0.59 kg greater estimated total GWG at delivery (95% CI, 0.12, 1.05; p = 0.014), a 10% lower risk of severely inadequate GWG (RR: 0.90; 95% CI: 0.83, 0.99; p = 0.025), and a 7% lower risk of inadequate GWG (RR: 0.93; 95% CI: 0.89, 0.97; p = 0.001). The effects of prenatal BEP on GWG outcomes were stronger in studies with a targeted approach, where BEP supplements were provided to participants in the intervention arm under specific criteria such as low body mass index or low GWG, compared to studies with an untargeted approach, where BEP supplements were provided to all participants allocated to the intervention arm. Conclusions Prenatal BEP supplements are effective in increasing GWG and reducing the risk of inadequate weight gain during pregnancy. BEP supplementation targeted toward pregnant women with undernutrition may be a promising approach to delivering the supplements.</p
Influence of praseodymium(iii) chloride on corrosion resistance of AS1020 steel in an environment containing chloride ions and carbon dioxide
No full textRare earth salts (RESs) are considered one of the good choices for anticorrosion due to their high inhibition efficiency via the suppression of oxygen reduction reactions. In this work, praseodymium chloride (PrCl3) was used as a potential inhibitor that can become a promising candidate for mitigating mild steel corrosion in environments rich in chloride and carbon dioxide. The results of electrochemical and surface analyses indicated that mild steel was protected from corrosion in a CO2-saturated sodium chloride solution throughout 72 hours immersion when PrCl3 was added to the solution. This was evidenced through considerably reduced corrosion current density, increased protective and charge transfer resistances, especially, random redistribution of minor anodes, as well as less corrosion-induced damages on the steel surfaces. Tafel extrapolations were applied to estimate the inhibition efficiency of PrCl3, achieving the highest value of 96.33 ± 0.47 % at 2.4 mM PrCl3. This positive result is primarily attributed to the formation of the barrier layer from praseodymium oxides and hydroxides in combination with iron(ii)-based products. Based on these findings, this work recommends a potential inhibitor for mitigating mild steel corrosion in aqueous media containing carbon dioxide and chloride ions.</p
Conserved and distinct expression of circular RNAs in commercially used Marek’s disease vaccine viruses
No full textCircular RNAs (circRNAs) are covalently closed RNA molecules, supporting a wide diversity of functions. While aberrant circRNA expression stands as a recognized hallmark of cancer development, our attention has turned to investigating their role in viral infections, specifically Mardivirus Gallidalpha 2 (GaHV-2, Marek’s disease virus) infection. In a previous study focused on the virulent GaHV-2 strain, RB-1B, we extensively catalogued circRNAs produced from virulence genes, notably from the MEQ-vIL-8 locus and the latency-associated transcripts (LATs) gene. Building upon this groundwork, our current investigation uncovers novel loci expressing viral circRNAs in distinct stages of GaHV-2 infection. Furthermore, we extend our focus to viral circRNA signatures in three commonly used Marek’s disease vaccines, the avirulent GaHV-2 (CVI988/Rispens strain), non-oncogenic Mardivirus Gallidalpha 3 (GaHV-3) and non-oncogenic Mardivirus Meleagridalpha 1 (MeHV-1) commercially called herpesvirus of turkey. In these vaccine viruses, we identified viral circRNA expression from a locus antisense to the ICP4 immediate early gene, a conserved feature across the three species. This region has been characterized herein for the first time in terms of candidate LATs’ exons and introns for GaHV-3 and MeHV-1. LATs’ circRNAs were then deeply analysed, and we observed both similarities and distinctions when compared with those of the virulent GaHV-2. Another conserved gene, encoding the DNA packaging protein, was identified as a source of circRNAs in all three species. Eventually, different levels of circRNAs were found to be expressed from the meq locus between virulent and avirulent GaHV-2 strains. Our findings highlight a conserved pattern of virus-derived circRNAs in these related avian alphaherpesviruses. This conservation underscores the potential significance of these transcripts in completing the viral cycle and facilitating viral spread.</p