Charge redistribution, charge order and plasmon in La2−x_{2-x}Srx_{x}CuO4_{4}/La2_{2}CuO4_{4} superlattices

Interfacial superconductors have the potential to revolutionize electronics, quantum computing, and fundamental physics due to their enhanced superconducting properties and ability to create new types of superconductors. The emergence of superconductivity at the interface of La$_{2-x}$Sr$_{x}$CuO$_{4}$/La$_{2}$CuO$_{4}$ (LSCO/LCO), with a T$_c$ enhancement of $\sim$ 10 K compared to the La$_{2-x}$Sr$_{x}$CuO$_{4}$ bulk single crystals, provides an exciting opportunity to study quantum phenomena in reduced dimensions. To investigate the carrier distribution and excitations in interfacial superconductors, we combine O K-edge resonant inelastic X-ray scattering and atomic-resolved scanning transmission electron microscopy measurements to study La$_{2-x}$Sr$_{x}$CuO$_{4}$/La$_{2}$CuO$_{4}$ superlattices (x=0.15, 0.45) and bulk La$_{1.55}$Sr$_{0.45}$CuO$_{4}$ films. We find direct evidence of charge redistribution, charge order and plasmon in LSCO/LCO superlattices. Notably, the observed behaviors of charge order and plasmon deviate from the anticipated properties of individual constituents or the average doping level of the superlattice. Instead, they conform harmoniously to the effective doping, a critical parameter governed by the T$_c$ of interfacial superconductors.Comment: 8 pages, 5 figure

A combination of methods needed to assess the actual use of provisioning ecosystem services

Failure to recognize that potential provisioning ecosystem services are not necessarily collected and used by people may have important consequences for management of land and resources. Accounting for people's actual use of ecosystem services in decision making processes requires a robust methodological approach that goes beyond mapping the presence of ecosystem services. But no such universally accepted method exists, and there are several shortcomings of existing methods such as the application of land use/cover as a proxy for provisioning ecosystem service availability and surveys based on respondents' recall to assess people's collection of e.g. wild food. By combining four complementary methods and applying these to the shifting cultivation systems of Laos, we show how people’s actual use of ecosystem services from agricultural fields differs from ecosystem service availability. Our study is the first in Southeast Asia to combine plot monitoring, collection diaries, repeat interviews, and participant observation. By applying these multiple methods borrowed from anthropology and botany among other research domains, the study illustrates that no single method is sufficient on its own. It is of key importance for scientists to adopt methods that can account for both availability of various services and actual use of those services

Effects of calorie restriction on life span of microorganisms

Calorie restriction (CR) in microorganisms such as budding and fission yeasts has a robust and well-documented impact on longevity. In order to efficiently utilize the limited energy during CR, these organisms shift from primarily fermentative metabolism to mitochondrial respiration. Respiration activates certain conserved longevity factors such as sirtuins and is associated with widespread physiological changes that contribute to increased survival. However, the importance of respiration during CR-mediated longevity has remained controversial. The emergence of several novel metabolically distinct microbial models for longevity has enabled CR to be studied from new perspectives. The majority of CR and life span studies have been conducted in the primarily fermentative Crabtree-positive yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, but studies in primarily respiratory Crabtree-negative yeast and obligate aerobes can offer complementary insight into the more complex mammalian response to CR. Not only are microorganisms helping characterize a conserved cellular mechanism for CR-mediated longevity, but they can also directly impact mammalian metabolism as part of the natural gut flora. Here, we discuss the contributions of microorganisms to our knowledge of CR and longevity at the level of both the cell and the organism

ATP modulates intracellular Ca2+ and firing rate through a P2Y1 purinoceptor in cane toad pacemaker cells

The effect of extracellular ATP (10–100 μm) on intracellular Ca2+ concentration ([Ca2+]i) and firing rate has been studied in single pacemaker cells isolated from the sinus venosus of cane toads. In spontaneously firing cells, ATP initially increased peak [Ca2+]i by 43 ± 5 %, increased diastolic [Ca2+]i by 20 + 3 % and increased the firing rate by 58 ± 8 %. These early effects were followed by a late phase in which both the peak [Ca2+]i and the firing rate declined. Adenosine, and UTP (respectively, P1- and P2Y2,4,6-selective agonists) caused no significant change in [Ca2+]i or firing rate, while αβ-methylene ATP (a P2X1,3 agonist) caused a small increase in firing rate but no changes in [Ca2+]i. In contrast the P2Y1-selective agonist 2-MesADP (1 μm) mimicked the biphasic effects of ATP and these effects were inhibited by the purinoceptor antagonists suramin and PPADS and by the P2Y1-selective antagonist MRS 2179. Immunohistochemistry established that P2Y1 purinoceptors were present on the cell surface. Western blotting analysis demonstrated that the P2Y1 antibody recognised a 57 kDa protein. After sarcoplasmic reticulum Ca2+ release was prevented with caffeine or ryanodine, ATP no longer had any effect on [Ca2+]i or firing rate. Furthermore, the SR Ca2+ store content was decreased during the late phase of 2-MesADP application. The effect of ATP was coupled to phospholipase C (PLC) activity because the PLC inhibitor U-73122 eliminated the effects of ATP. Our study shows that in toad pacemaker cells, the biphasic effects of ATP on pacemaker activity are mainly through P2Y1 purinoceptors, which are able to modulate Ca2+ release from the SR Ca2+ store

Quasi-Classical Trajectory Calculation of Rate Constants Using an Ab Initio Trained Machine Learning Model (aML-MD) with Multifidelity Data

Machine learning (ML) provides a great opportunity for the construction of models with improved accuracy in classical molecular dynamics (MD). However, the accuracy of a ML trained model is limited by the quality and quantity of the training data. Generating large sets of accurate ab initio training data can require significant computational resources. Furthermore, inconsistent or incompatible data with different accuracies obtained using different methods may lead to biased or unreliable ML models that do not accurately represent the underlying physics. Recently, transfer learning showed its potential for avoiding these problems as well as for improving the accuracy, efficiency, and generalization of ML models using multifidelity data. In this work, ab initio trained ML-based MD (aML-MD) models are developed through transfer learning using DFT and multireference data from multiple sources with varying accuracy within the Deep Potential MD framework. The accuracy of the force field is demonstrated by calculating rate constants for the H + HO2 → H2 + 3O2 reaction using quasi-classical trajectories. We show that the aML-MD model with transfer learning can accurately predict the rate constants while reducing the computational cost by more than five times compared to the use of more expensive quantum chemistry training data sets. Hence, the aML-MD model with transfer learning shows great potential in using multifidelity data to reduce the computational cost involved in generating the training set for these potentials

Type of tea consumption and depressive symptoms in Chinese older adults

10.1186/s12877-021-02203-zBMC Geriatrics21133

Data from: Revealing biogeographic patterns in genetic diversity of native and invasive plants and their association with soil community diversity in the Chinese coast

Within-species genetic diversity is shaped by multiple evolutionary forces within the confines of geography, and has cascading effects on the biodiversity of other taxa and levels. Invasive species are often initially limited in genetic diversity but still respond rapidly to their new range, possibly through 'pre-adapted' genotypes or multiple sources of genetic diversity, but little is known about how their genetic structure differs from that of native species and how it alters the genetic-species diversity relationship. Here, we selected a widespread native species (Phragmites australis) and its co-occurring invasive competitor (Spartina alterniflora) as our model plant species. We investigated the genetic structure of P. australis using two chloroplast fragments and ten nuclear microsatellites in 13 populations along the Chinese coastal wetlands. We discovered a distinct geographical differentiation, showing that the northern and southern populations harbored unique genotypes. We also found a significant increase in genetic diversity (allelic richness and expected heterozygosity) from south to north. Combined with previous studies of S. alterniflora, the Mantel tests revealed a significant correlation of genetic distances between P. australis and S. alterniflora even when controlling for geographic distance, suggesting that the invasive species S. alterniflora might exhibit a phylogeographic pattern similar to that of the native species to some extent. Furthermore, our results suggest that the S. alterniflora invasion has altered the relationship between the genetic diversity of the dominant native plant and the associated species richness of soil nematodes. The reason for the alteration of genetic-species diversity relationship might be that the biological invasion weakens the environmental impact on both levels of biodiversity. Our findings contribute to understanding the latitudinal patterns of intraspecific genetic diversity in widespread species. This work on the genetic diversity analysis of native species also provides significant implications for the invasion stage and ecological consequences of biological invasions.Funding provided by: National Natural Science Foundation of ChinaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809Award Number: 32100304Funding provided by: Ministry of Natural Resources of the People's Republic of ChinaCrossref Funder Registry ID: http://dx.doi.org/10.13039/100015809Award Number: 2022101Funding provided by: National Natural Science Foundation of ChinaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809Award Number: U22A20558Funding provided by: National Natural Science Foundation of ChinaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809Award Number: 32171661Sampling, genotyping and sequencing of P. australis We collected 194 individuals of P. australis from 13 sites along the Chinese coast. To avoid collecting the same clone and to get enough genetic variation, we selected five P. australis reed populations within each site, with a distance of at least 1 km between stands. We collected three individuals from each population. All individuals were transplanted with rhizomes in a common garden at the Jiangwan Campus of Fudan University in Shanghai (31.28°N, 121.48°E). After the plants regrew, we collected and dried young leaves from all individuals, and stored them in zip-lock plastic bags with silica gel at room temperature until DNA isolation. We extracted total DNA from the dried leaves according to a modified cetyltrimethylammonium bromide (CTAB) method. We examined the quality and quantity of extracted DNA with 1% agarose gels and a microscope spectrophotometer, and stored DNA at -20℃ until later genotyping and sequencing. To measure genetic variation, we used 10 microsatellite primer pairs previously designed for P. australis (Saltonstall 2003, Yu et al. 2013). Forward primers were labeled at the 5' end with the fluorescent dyes FAM, HEX or TAMRA. We performed polymerase chain reaction (PCR) as described by Liu et al. (2022), and separated the PCR products by capillary electrophoresis using an ABI 3730XL DNA capillary sequencer (Applied Biosystems, Foster City, California, USA) after confirming the PCR product on a 2% agarose gel. We scored fragment profiles and carefully check the stutter peaks and the low-frequency alleles with GeneMarker 2.2.0 to reduce the potential effect of null allele. We did not discover the null alleles with the Hardy-Weinberg equilibrium-based method, since there is no reliable approach to elimination of allele dosage for our polyploid data. The same clones were detected by the function assignClones in R package polysat (Clark and Jasieniuk 2011). The duplicated genotypes were removed for further genetic estimates. To determine the haplotype, we amplified two non-coding chloroplast regions by PCR in one sample of each stand, using the primer pairs [trnT (UGU) "a"-trnL (UAA) "b" and rbcL-psaI] as described previously (Saltonstall 2002). We sequenced the PCR products in both directions on an ABI 3730XL DNA sequencer (Applied Biosystems). We assembled and checked the sequencing with SeqMan 7.7.0 (Lasergene, Santa Clara, USA) and identified haplotypes to the naming scheme of P. australis described by Saltonstall (Saltonstall 2016). Data analysis of genetic diversity and structure of P. australis To estimate the genetic diversity level of P. australis, we calculated the number of alleles per locus or allelic richness (Na), and the expected heterozygosity (He) with R package polysat (Clark and Jasieniuk 2011). We assessed the relationship between genetic diversity and latitude using linear regression. To assess the genetic structure of P. australis, we calculated genetic differentiation (Fst) with the R package polysat. We also calculated Pairwise Bruvo distances based on microsatellite variation, and used the genetic distance matrix for principal coordinates analysis (PCoA) and hierarchical cluster analysis using the unweighted pair-group method with arithmetic means (UPGMA). We applied Bayesian clustering with Structure 2.3.4 (Pritchard et al. 2000) to detect the genetic structure of P. australis. We performed 20 replicates of the clustering analysis at each value of K from 1 to 10 under the admixture model with 50,000 burn-in steps and 500,000 Markov Chain Monte Carlo repeats. We calculated Delta K using the online program Structure Harvest (Earl and vonHoldt 2012) to determine the most likely cluster number (K value) for our genetic data, grouped replicates in CLUMPP 1.1.2b (Jakobsson and Rosenberg 2007) and visualized in DISTRUCT 1.1 (Ramasamy et al. 2014). Correlation analysis between geographical and genetic distances of P. australis and S. alterniflora We used the previously published nuclear microsatellites and chloroplast sequences data of S. alterniflora in China (Qiao et al. 2019, Shang et al. 2019, Xia et al. 2020). We extracted the geographical coordinates and the diversity indices (i.e., Allele number, Na; Expected heterozygosity, He) of surveyed populations of S. alterniflora from Shang et al. (2019) and Xia et al. (2020) for further comparisons. For genetic analysis of S. alterniflora, we used the raw data of 11 nuclear microsatellites from Qiao et al. (2019). We removed three loci from the raw dataset because there were many missing values or null alleles in loci 5, 7 and 9. We calculated geographic distances using the function distm in R package geosphere and used pairwise Fst for genetic distance. We used Mantel test and multiple matrix regression with randomization (MMRR) (Wang 2013) to examine relationships between geographic and genetic distance matrices at the site level. We ran correlation analyses between geographical and genetic distance matrices using the function mantel in R package vegan, and regression analyses using the function MMRR written by Wang (2013) with genetic distance as the dependent matrix and geographical distances as the independent (predictor) matrices with 9,999 permutations. The correlation of genetic distances between the two species were also performed with partial Mantel test while controlling the geographical distance for seven common sites. Correlation between genetic variation and nematode community We used the geographic records of nematode genera from a published work (Zhang et al. 2019). These nematode data were investigated to reveal the biotic homogenization of nematode communities by exotic S. alterniflora in China. This study found a clear latitudinal cline (nematode diversity increased with increasing latitude) and a strong correlation of nematode diversity to environmental variables in soils for P. australis, but weak for S. alterniflora (Zhang et al. 2019). Because the TJ and TS sites were located within a very short distance (approximately 54 km) around the same bay, we considered them as one site when comparing the variation in geography, genetics, and community. Thus, we had seven common sites with both genetic and nematode information. We estimated the Jaccard distances between nematode communities using the function dist with a method binary parameter. We used these Jaccard distances to perform principal coordinates analysis (PCoA) of nematodes. Matrix correlation analyses between geographic, genetic and nematode distance matrices for seven common sites were performed using both Mantel test using the function mantel in R package vegan and MMRR using the function MMRR written by Wang (2013) with nematode distance matrices as the dependent variable using 9,999 permutations

Delayed and restricted expression of UAS-regulated GFP gene in early transgenic zebrafish embryos by using the GAL4/UAS system

10.1007/s10126-009-9217-yMarine Biotechnology1211-7MABI