High-Temperature Superconducting Level Meter for Liquid Argon Detectors

Capacitive devices are customarily used as probes to measure the level of noble liquids in detectors operated for neutrino studies and dark matter searches. In this work we describe the use of a high-temperature superconducting material as an alternative to control the level of a cryogenic noble liquid. Lab measurements indicate that the superconductor shows a linear behaviour, a high degree of stability and offers a very accurate determination of the liquid volume. This device is therefore a competitive instrument and shows several advantages over conventional level meters.Comment: 13 pages, 11 figures. Accepted for publication in JINS

rDock: A Fast, Versatile and Open Source Program for Docking Ligands to Proteins and Nucleic Acids

Identification of chemical compounds with specific biological activities is an important step in both chemical biology and drug discovery. When the structure of the intended target is available, one approach is to use molecular docking programs to assess the chemical complementarity of small molecules with the target; such calculations provide a qualitative measure of affinity that can be used in virtual screening (VS) to rank order a list of compounds according to their potential to be active. rDock is a molecular docking program developed at Vernalis for high-throughput VS (HTVS) applications. Evolved from RiboDock, the program can be used against proteins and nucleic acids, is designed to be computationally very efficient and allows the user to incorporate additional constraints and information as a bias to guide docking. This article provides an overview of the program structure and features and compares rDock to two reference programs, AutoDock Vina (open source) and Schrodinger's Glide (commercial). In terms of computational speed for VS, rDock is faster than Vina and comparable to Glide. For binding mode prediction, rDock and Vina are superior to Glide. The VS performance of rDock is significantly better than Vina, but inferior to Glide for most systems unless pharmacophore constraints are used; in that case rDock and Glide are of equal performance. The program is released under the Lesser General Public License and is freely available for download, together with the manuals, example files and the complete test sets, at http://rdock.sourceforge.net

Dynamical generation of a gauge symmetry in the Double-Exchange model

It is shown that a bosonic formulation of the double-exchange model, one of the classical models for magnetism, generates dynamically a gauge-invariant phase in a finite region of the phase diagram. We use analytical methods, Monte Carlo simulations and Finite-Size Scaling analysis. We study the transition line between that region and the paramagnetic phase. The numerical results show that this transition line belongs to the Universality Class of the Antiferromagnetic RP(2) model. The fact that one can define a Universality Class for the Antiferromagnetic RP(2) model, different from the one of the O(N) models, is puzzling and somehow contradicts naive expectations about Universality

Perspective of US farmers on collaborative on-farm agronomic research

On-farm research has emerged in recent years as a unique approach to involve farmers and other agricultural stakeholders as active participants in knowledge development and as an effective method of technology and innovation transfer across farms. This study assessed the perspective and knowledge of US farmers regarding on-farm research via the implementation of a 24-question survey distributed across most of the US Midwest and South-Central regions.We found that farmers generally are willing to engage with universities to conduct on-farm research and were 40% more likely to adopt practices supported by on-farm research findings than research not conducted on-farm. Notably, a shift toward conservation practices was made, with cover crops and no-till at the forefront. Insights of this nature have implications for fostering collaborations, addressing constraints, and maximizing the impact of on-farm research, offering guidance for sustainable agriculture progress in the United States and beyond. Results from this research survey could be used to initiate much-needed policies to promote on-farm research. Further, information on the benefits and drawbacks of on-farm research could be used in the development of studies that benefit both farmers and researchers

Cell Survival Enabled by Leakage of a Labile Metabolic Intermediate

Many metabolites are generated in one step of a biochemical pathway and consumed in a subsequent step. Such metabolic intermediates are often reactive molecules which, if allowed to freely diffuse in the intracellular milieu, could lead to undesirable side reactions and even become toxic to the cell. Therefore, metabolic intermediates are often protected as protein-bound species and directly transferred between enzyme active sites in multi-functional enzymes, multi-enzyme complexes, and metabolons. Sequestration of reactive metabolic intermediates thus contributes to metabolic efficiency. It is not known, however, whether this evolutionary adaptation can be relaxed in response to challenges to organismal survival. Here, we report evolutionary repair experiments on Escherichia coli cells in which an enzyme crucial for the biosynthesis of proline has been deleted. The deletion makes cells unable to grow in a culture medium lacking proline. Remarkably, however, cell growth is efficiently restored by many single mutations (12 at least) in the gene of glutamine synthetase. The mutations cause the leakage to the intracellular milieu of a highly reactive phosphorylated intermediate common to the biosynthetic pathways of glutamine and proline. This intermediate is generally assumed to exist only as a protein-bound species. Nevertheless, its diffusion upon mutation-induced leakage enables a new route to proline biosynthesis. Our results support that leakage of sequestered metabolic intermediates can readily occur and contribute to organismal adaptation in some scenarios. Enhanced availability of reactive molecules may enable the generation of new biochemical pathways and the potential of mutation-induced leakage in metabolic engineering is noted.This work was supported by Human Frontier Science Program Grant RGP0041/2017 (J.M.S.R. and B.S.), Spanish Ministry of Science and Innovation FEDER Funds Grants RTI2018-097142-B-100 and PID2021-124534OB-100 (J.M.S.R.), National Aeronautics and Space Administration (NASA) Grant 80NSSC18K1277 (B.S.) Grant RYC2021-031155-I (E.M.C.) from Spanish Ministry of Science and Innovation and NextGenerationEU/PRTR and Grant E-BIO-464-UGR-20 (E.M.C.) from FEDER Funds and Consejería de Economía, Conocimiento, Empresas y Universidad de la Junta de Andalucia. E.A.L. was a recipient of a postdoctoral fellowship from the regional Andalusian Government (2020_DOC_00541). We thank the “Centro de Supercomputacion” (ALHAMBRA-CSIRC) of the University of Granada for providing computational resources and Dr Valeria A. Risso for useful discussions, comments on the manuscript and help with the evolutionary and structural analyses of the rescuing mutations.Peer reviewe

Cross section measurements of the 3He(alpha, gamma) 7Be reaction using DRAGON at TRIUMF.

4 pags., 2 figs. -- Nuclear Physics in Astrophysics V 3–8 April 2011, Eilat, IsraelWe present our initial efforts with the DRAGON separator at TRIUMF facility towards obtaining the energy dependence of the astrophysical S-factor for 3He(¿, ¿)7Be reaction in the energy range of Ecm = 2 to 3 MeV that was recommended by the recent evaluations. A comparison between the existing data and our new complementary Madrid data, together with the recent theoretical calculations, is also given in the context of our ongoing work.This work has been supported by the UK STFC

Modes, mechanisms and evidence of bet hedging in rotifer diapause traits

In this contribution, we review our knowledge on bet-hedging strategies associated with rotifer diapause. First, we describe the ecological scenario under which bet hedging is likely to have evolved in three diapause-related traits in monogonont rotifer populations: (1) the timing of sex (because diapausing eggs are produced via sexual reproduction), (2) the sexual reproduction ratio (i.e. the fraction of sexually reproducing females) and (3) the timing of diapausing egg hatching. Then, we describe how to discriminate among bet-hedging modes and discuss which modes and mechanisms better fit the variability observed in these traits in rotifers. Finally, we evaluate the strength of the empirical evidence for bet hedging in the scarce studies available, and we call for the need of research at different levels of biological complexity to fully understand bet hedging in rotifer diapause

BMP2/BMP4 colorectal cancer susceptibility loci in northern and southern european populations

Genome-wide association studies have successfully identified 20 colorectal cancer susceptibility loci. Amongst these, four of the signals are defined by tagging single nucleotide polymorphisms (SNPs) on regions 14q22.2 (rs4444235 and rs1957636) and 20p12.3 (rs961253 and rs4813802). These markers are located close to two of the genes involved in bone morphogenetic protein (BMP) signaling (BMP4 and BMP2, respectively). By investigating these four SNPs in an initial cohort of Spanish origin, we found substantial evidence that minor allele frequencies (MAFs) may be different in northern and southern European populations. Therefore, we genotyped three additional southern European cohorts comprising a total of 2028 cases and 4273 controls. The meta-analysis results show that only one of the association signals (rs961253) is effectively replicated in the southern European populations, despite adequate power to detect all four. The other three SNPs (rs4444235, rs1957636 and rs4813802) presented discordant results in MAFs and linkage disequilibrium patterns between northern and southern European cohorts. We hypothesize that this lack of replication could be the result of differential tagging of the functional variant in both sets of populations. Were this true, it would have complex consequences in both our ability to understand the nature of the real causative variants, as well as for further study designs

The influence of the physical education teacher on intrinsic motivation, self-confidence, anxiety, and pre-and post-competition mood states

One of the fundamental problems facing teachers of physical education (PE) is how to increase pupils' motivation. From the point of view of goal achievement, guidelines need to be established so that information may be used to greater effect in classes. This study examined the relationship between the motivational climate created by the PE teacher and the intrinsic motivation of the preparatory sessions together with self-confidence and anxiety prior to competition and pre- and post-competition mood states. The sample was made up of school children (M age = 11.7) from a state school (N = 115), who, after an introduction to an athletics course of 12 sessions, took part in a sports competition. During this time, a teacher (trained to this effect) manipulated the motivational climate, adapting the strategies of TARGET (11, 12, 26, 28). The mastery climate was linked to enjoyment, perceived ability, and effort in the PE classes, as well as to pre-competition somatic anxiety and post-competition vigor. On the other hand, the performance climate was associated with self-confidence, pre-competition vigor, and post-competition stress. The results are discussed in relation to achievement goal theory and motivational climate manipulation