Introgression is widespread in the radiation of carnivorous Nepenthes pitcher plants.

Introgression and hybridization are important processes in plant evolution, but they are difficult to study from a phylogenetic perspective, because they conflict with the bifurcating evolutionary history typically depicted in phylogenetic models. The role of hybridization in plant evolution is best documented in the form of allo-polyploidizations. In contrast, homoploid hybridization and introgression are less explored, although they may be crucial in adaptive radiations. Here we employ genome-wide data (ddRAD-seq, transcriptomes) to investigate the evolutionary history of Nepenthes, a radiation of c. 160 species of iconic carnivorous plants mainly from tropical Asia. Our data indicates that the main radiation is only c. 5 million years old, and confirms previous bifurcating phylogenies. However, due to a greatly expanded number of loci, we were able test for the first time the long-standing hypotheses of introgression and historical hybridization. The genus presents one very clear case of organellar capture between two distantly related but sympatric groups. Furthermore, all Nepenthes species show introgression signals in their nuclear genomes, as uncovered by a general survey of ABBA-BABA-like statistics. The ancestor of the rapid main radiation shows ancestry from two deeply diverged lineages, as indicated by phylogenetic network analyses. All major clades of the main radiation show further introgression both within and between each other, as suggested by admixture graphs. Our study supports the hypothesis that rapid adaptive radiations are hotspots of introgression in the tree of life, and highlights the need to consider non-treelike processes in evolutionary studies of Nepenthes in particular

Evolutionary footprints of a cold relic in a rapidly warming world

With accelerating global warming, understanding the evolutionary dynamics of plant adaptation to environmental change is increasingly urgent. Here we reveal the enigmatic history of the genus Cochlearia (Brassicaceae), a Pleistocene relic that originated from a drought-adapted Mediterranean sister genus during the Miocene. Cochlearia rapidly diversified and adapted to circum-Arctic regions and other cold-characterized habitat types during the Pleistocene. This sudden change in ecological preferences was accompanied by a highly complex, reticulate polyploid evolution, which was apparently triggered by the impact of repeated Pleistocene glaciation cycles. Our results illustrate that two early diversified arctic-alpine diploid gene pools contributed differently to the evolution of this young polyploid genus now captured in a cold-adapted niche. Metabolomics revealed central carbon metabolism responses to cold in diverse species and ecotypes, likely due to continuous connections to cold habitats that may have facilitated widespread adaptation to alpine and subalpine habitats, and which we speculate were coopted from existing drought adaptations. Given the growing scientific interest in adaptive evolution of temperature-related traits, our results provide much-needed taxonomic and phylogenomic resolution of a model system as well as first insights into the origins of its adaptation to cold

Modular Superconducting Qubit Architecture with a Multi-chip Tunable Coupler

We use a floating tunable coupler to mediate interactions between qubits on separate chips to build a modular architecture. We demonstrate three different designs of multi-chip tunable couplers using vacuum gap capacitors or superconducting indium bump bonds to connect the coupler to a microwave line on a common substrate and then connect to the qubit on the next chip. We show that the zero-coupling condition between qubits on separate chips can be achieved in each design and that the relaxation rates for the coupler and qubits are not noticeably affected by the extra circuit elements. Finally, we demonstrate two-qubit gate operations with fidelity at the same level as qubits with a tunable coupler on a single chip. Using one or more indium bonds does not degrade qubit coherence or impact the performance of two-qubit gates.Comment: 9 pages, 6 figure

Ncs2* mediates in vivo virulence of pathogenic yeast through sulphur modification of cytoplasmic transfer RNA.

Fungal pathogens threaten ecosystems and human health. Understanding the molecular basis of their virulence is key to develop new treatment strategies. Here, we characterize NCS2*, a point mutation identified in a clinical baker's yeast isolate. Ncs2 is essential for 2-thiolation of tRNA and the NCS2* mutation leads to increased thiolation at body temperature. NCS2* yeast exhibits enhanced fitness when grown at elevated temperatures or when exposed to oxidative stress, inhibition of nutrient signalling, and cell-wall stress. Importantly, Ncs2* alters the interaction and stability of the thiolase complex likely mediated by nucleotide binding. The absence of 2-thiolation abrogates the in vivo virulence of pathogenic baker's yeast in infected mice. Finally, hypomodification triggers changes in colony morphology and hyphae formation in the common commensal pathogen Candida albicans resulting in decreased virulence in a human cell culture model. These findings demonstrate that 2-thiolation of tRNA acts as a key mediator of fungal virulence and reveal new mechanistic insights into the function of the highly conserved tRNA-thiolase complex

Linear oscillatory cellular thermocapillary convection in liquid layers

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76679/1/AIAA-232-799.pd

Constructivism: Defense or a Continual Critical Appraisal – A Response to Gil-Pérez et al.

Abstract. This commentary is a critical appraisal of Gil-Pérez et al.’s (2002) conceptualization of constructivism. It is argued that the following aspects of their presentation are problematic: (a) Although the role of controversy is recognized, the authors implicitly subscribe to a Kuhnian perspective of ‘normal’ science; (b) Authors fail to recognize the importance of von Glasersfeld’s contribution to the understanding of constructivism in science education; (c) The fact that it is not possible to implement a constructivist pedagogy without a constructivist epistemology has been ignored; and (d) Failure to recognize that the metaphor of the ‘student as a developing scientist’ facilitates teaching strategies as students are confronted with alternative/rival/conflicting ideas. Finally, we have shown that constructivism in science education is going through a process of continual critical appraisals

Secondary school students’ epistemic insight into the relationships between science and religion – a preliminary enquiry

A number of previous studies have shown that there is a widespread view among young people that science and religion are opposed. In this paper, we suggest that it requires a significant level of what can be termed ‘epistemic insight’ to access the idea that some people see science and religion as compatible while others do not. To explore this further, we draw on previous work to devise a methodology to discover students’ thinking about apparent contradictions between scientific and religious explanations of the origins of the universe. In our discussion of the findings, we highlight that students’ epistemic insight in this context does seem in many cases to be limited and we outline some of the issues emerging from the study that seem to boost or limit students’ progress in this area

Attributable mortality of candidemia – Results from the ECMM Candida III multinational European Observational Cohort Study

\ua9 2024 The Author(s)Introduction: Despite antifungal advancements, candidaemia still has a high mortality rate of up to 40%. The ECMM Candida III study in Europe investigated the changing epidemiology and outcomes of candidaemia for better understanding and management of these infections. Methods: In this observational cohort study, participating hospitals enrolled the first ten consecutive adults with blood culture-proven candidemia. Collected data included patient demographics, risk factors, hospital stay duration (follow-up of 90 days), diagnostic procedures, causative Candida spp., management details, and outcome. Controls were included in a 1:1 fashion from the same hospitals. The matching process ensured similarity in age (10-year range), primary underlying disease, hospitalization in intensive care versus non-ICU ward, and major surgery within 2 weeks before candidemia between cases and controls. Overall and attributable mortality were described, and a survival probability for cases and controls was performed. Results: One hundred seventy-one pairs consisting of patients with candidemia and matched controls from 28 institutions were included. In those with candidemia, overall mortality was 40.4%. Attributable mortality was 18.1% overall but differed between causative Candida species (7.7% for Candida albicans, 23.7% for Candida glabrata/Nakaseomyces glabratus, 7.7% for Candida parapsilosis and 63.6% for Candida tropicalis). Regarding risk factors, the presence of a central venous catheter, total parenteral nutrition and acute or chronic renal disease were significantly more common in cases versus controls. Duration of hospitalization, and especially that of ICU stay, was significantly longer in candidemia cases (20 (IQR 10–33) vs 15 days (IQR 7–28); p = 0.004). Conclusions: Although overall and attributable mortality in this subgroup analysis of matched case/control pairs remains high, the attributable mortality appears to have decreased in comparison to historical cohorts. This decrease may be driven by improved prognosis of Candida albicans and Candida parapsilosis candidemia; whereas candidemia due to other Candida spp. exhibits a much higher attributable mortality

Should science educators deal with the science/religion issue?

I begin by examining the natures of science and religion before looking at the ways in which they relate to one another. I then look at a number of case studies that centre on the relationships between science and religion, including attempts to find mechanisms for divine action in quantum theory and chaos theory, creationism, genetic engineering and the writings of Richard Dawkins. Finally, I consider some of the pedagogical issues that would need to be considered if the science/religion issue is to be addressed in the classroom. I conclude that there are increasing arguments in favour of science educators teaching about the science/religion issue. The principal reason for this is to help students better to learn science. However, such teaching makes greater demands on science educators than has generally been the case. Certain of these demands are identified and some specific suggestions are made as to how a science educator might deal with the science/religion issue. © 2008 Taylor & Francis