Browse Articles

An investigation into the spatial patterns of invasive common milkweed (Asclepias syriaca L.) stands through the utilization of drone images

Abstract The phenomenon of biological invasions represents one of the most significant threats to biodiversity. A fundamental aspect of combating invasive plant species is the comprehension of the spatial and temporal alterations in their population dynamics. One of the important habitats of the European Union is the Pannon sand grasslands in Hungary, which are primarily threatened by the invasive common milkweed (Asclepias syriaca). The objective of this study was to ascertain the efficacy of drone imaging in examining the spatial patterns of milkweed shoots in comparison to ground survey data. To facilitate comparison, a survey was conducted on 12 milkweed populations in the Fülöpháza area of Kiskunság National Park. In each population, a 12-meter transect (comprising six contiguous 2 m × 2 m quadrats) was designated within which the positions of the shoots were recorded with centimeter accuracy through ground surveys. The individual shoots were marked on images captured from an altitude of 20 m using a drone. The results indicated that the number of shoots identified in the drone images was slightly lower than in the ground surveys; however, a positive correlation was observed between the two datasets (r = 0.9594). A strong positive correlation was evident between the ground and drone surveys in terms of both the average distance between shoots and the observed pattern (r = 0.933 and r = 0.9146). In light of these findings, it can be concluded that drone imaging represents an effective method for examining the size and pattern of populations. Consequently, it may prove to be a valuable tool for the accurate planning of invasive species management in conservation efforts and the monitoring of the effectiveness of treatments.

Fluctuations of driven probes reveal nonequilibrium transitions in complex fluids

Complex fluids subjected to localized microscopic energy inputs, typical of active microrheology setups, exhibit poorly understood nonequilibrium behaviors because of the intricate self-organization of their mesoscopic constituents. In this work, we show how to identify changes in the microstructural conformation of the fluid by monitoring the variance of the probe position, based on a general method grounded in the breakdown of the equipartition theorem. To illustrate our method, we perform large-scale Brownian dynamics simulations of an effective model of micellar solution and we link the different scaling regimes in the variance of the probe’s position to the transitions from diffusive to jump dynamics, where the fluid intermittently relaxes the accumulated stress. This suggests that stored elastic stress may be the physical mechanism behind the nonlinear friction curves recently measured in micellar solutions, pointing at a mechanism for the observed multi-step rheology. Our approach overcomes the limitations of continuum macroscopic descriptions and introduces an empirical method, applicable in experiments, to detect nonequilibrium transitions in the structure of complex fluids.

The efficacy and safety of inhaled peptide YKYY017 for COVID-19 patients with mild illness: a phase 2 randomized controlled trial

Parental social environment has transgenerational effects on zebrafish (Danio rerio) growth

The state-dependence of the diffusion-controlled transport: Transitions and relaxations

The transport through a medium is primarily identified with the rate of the process and population densities inside it. The environmental conditions, such as the viscosity and temperature of the system, effectively the diffusion coefficients, govern stochastic transports. In addition, the structure of the potential characterizing the medium plays a crucial role in determining the key features of the transitions and relaxations. Here, we explore the importance of detailed information about the medium of transport in terms of the diffusion coefficient and the position of the reference point at which the rate is measured. Our study reveals that the varying positions of the states considered and the diffusion coefficient characterizing them have significant impacts on the integrated understanding of the kinetics of the diffusion-limited processes. We consider the left-to-right well transition in a double-well potential. We vary the location of the reference point systematically in the right well to measure the state-dependent rate. Interestingly, we observe that the rate exhibits a power-law relation with the distance from the barrier top. Another important perspective of our study is to consider varying diffusion coefficients for the two wells to account for the state-dependent fluctuations and explore their effects in the determination of rates of the transport processes. The observations reveal some critical aspects regarding the fundamental roles of the originating and target states in transport. The results of the current study not only enrich the elemental understanding of diffusion-controlled kinetics but also indicate the paths in developing advantageous technologies based on optimizing the conditions of transport.

Murine hematopoietic progenitor cell lines with erythroid and megakaryocyte potential

Abstract Red blood cells and platelets derive from bi-potential bone marrow megakaryocyte-erythroid progenitors, but their study is constrained by cell scarcity and limited experimental systems. Here we show that conditional expression of a virally transduced, regulated form of Hoxa7 enables expansion of murine cells resembling megakaryocyte-erythroid progenitors (Hoxa7-TPO), which undergo erythro-megakaryocytic differentiation upon Hoxa7 inactivation. The close relationship of Hoxa7-TPO cells to megakaryocyte-erythroid progenitors is supported by genetic and phenotypic analyses, and mature Hoxa7-TPO-derived red blood cells and platelets are largely indistinguishable from their primary counterparts. Genetic knock-out studies in Hoxa7-TPO cells recapitulate the key function of Klf1 and Nfe2 in red blood cell and platelet development, respectively, while disruption of the von Willebrand receptor gene Gp1ba recapitulates features of human Bernard-Soulier syndrome. Hence, we developed a versatile experimental system for expansion and differentiation of megakaryocyte-erythroid progenitors to study red blood cell and platelet development and model human diseases.

Statistical inference and applications of a new transforming weibull distribution

Three-photon quantum cutting infrared emission based on two-step energy transfers in Er3+ doped bi-perovskite Ca2ScSbO6 phosphors: Mechanism and efficiency

Quantum cutting (QC) materials still attract significant attention due to their high quantum and energy efficiencies, which stem from the effective utilization of the excitation energy. In this study, a one-to-three QC 1544 nm emission was first developed in an Er3+ single-doped Ca2ScSbO6 phosphor system. The Ca2ScSbO6 host was selected since it possesses moderate maximum-phonon energy, which suppresses non-radiative relaxation while maintaining phonon-assisted energy transfers between Er3+ ions. Spectroscopic measurements elucidated the QC mechanisms that two-step energy transfers, including ET1: 4S3/2(2H11/2) + 4I15/2 → 4I9/2 + 4I13/2 and ET2: 4I9/2 + 4I15/2 → 4I13/2 + 4I13/2 processes, are responsible for the three-photon generation. The radiative transitions, non-radiative relaxations, and energy transfers of pertinent levels were taken into consideration when calculating the QC efficiencies for Er3+ doped Ca2ScSbO6 phosphors with varying Er3+ concentrations. The concerned radiative transition rates of Er3+ in Ca2ScSbO6 were calculated in the framework of Judd–Ofelt theory, while the non-radiative transition rates were derived based on the energy gap law. The maximum energy transfer efficiencies for ET1 and ET2 were determined to be 99% and 93%. Finally, the QC efficiencies for Er3+ doped Ca2ScSbO6 phosphors were calculated, and the maximum value was confirmed in the 20 mol. % Er3+ doped sample to be 232%. The primary reason for the deviation of the QC efficiencies from the theoretical maximum value of 300% was attributed to the fluorescence self-quenching of Er3+.

Effervescence in a binary mixture with nonlinear non-reciprocal interactions

Abstract Non-reciprocal interactions between scalar fields that represent the concentrations of two active species are known to break the parity and time-reversal (PT) symmetries of the equilibrium state, as manifested in the emergence of travelling waves. We explore the notion of nonlinear non-reciprocity and consider a model in which the non-reciprocal interactions can depend on the local values of the scalar fields in such a way that the non-reciprocity can change sign. For generic cases where such couplings exist, we observe the emergence of spatiotemporal chaos in the steady-state. We associate this chaotic behaviour with a local restoration of PT symmetry in fluctuating spatial domains, which leads to the coexistence of oscillating densities and phase-separated droplets that are spontaneously created and annihilated. We uncover that this phenomenon, which we denote as effervescence, can exist as a dynamical steady-state in large parts of the parameter space in two different incarnations, as characterised by the presence or absence of an accompanying travelling wave.

Inducing memristive behavior to MoSe2/graphene bilayer using plasma treatment

Oriented composition fluctuation domains of a two-dimensionally confined critical Ising fluid

A quasi-binary two-dimensional Ising critical system with the main components D2O and butyric acid confined by surfactant layers has been studied. The surfactant forms large planar layers and is the basis of the charge density waves with wave fronts aligned with the layers. To orient the domains in an external magnetic field, thulium ions were added to the system (replacing sodium in the surfactant with thulium and adding more TmCl3). The critical behavior of the forward scattering and the correlation length were observed to be more mean-field-like. This can be explained by the presence of the trivalent thulium ions mediating between water and butyric acid. The high-Q scattering could be distinguished in the different directions and the ideal two-dimensional critical composition fluctuation exponent ηxy = 1/4 was observed, while the other exponent ηz = −0.08 ± 0.06 was slightly negative due to a finite acceptance angle and the finite magnetic field. The orientationally averaged high-Q exponent x of this study is well-explained by ηxy = 1/4 of the two-dimensional Ising behavior and ηz = 0.

Urinary Complement proteome strongly linked to diabetic kidney disease progression

Evaluation of the quality and reliability of Chinese content about orthognathic surgery on BiliBili and TikTok: a cross-sectional study

Sound attenuation in glasses

Comprehending sound attenuation is integral to understanding the anomalous low temperature properties of glasses. Despite decades of studies, the underlying mechanism of sound attenuation in glasses is still debated. In this perspective, we review recent work on sound attenuation in amorphous solids. We focus on the role of defects and heterogeneous elasticity, and we also discuss attenuation in model amorphous solids without defects. We review our definition of attenuation defects and show that they strongly influence sound attenuation. However, we also find another contribution to sound attenuation that cannot be attributed to attenuation defects. We confirm an earlier result of Kapteijns et al. [Kapteijns et al., J. Chem. Phys. 154, 081101 (2021)] that heterogeneous elasticity theory predicts relative changes of sound attenuation in model two-dimensional glasses if the configuration-to-configuration elastic constants fluctuations are used to quantify the heterogeneity. We extend this finding to similar three-dimensional glasses. We end by discussing the Euclidean random matrix model, which exhibits Rayleigh scaling of sound attenuation but does not have quasi-localized excitations and, thus, probably does not have sound attenuation defects. We propose that the mechanisms behind sound attenuation can be more fully understood by approaching the problem from two directions: one where the strong influence of defects is studied and another where sound attenuation is studied in defect free, although disordered, materials.

Iterative SCRaMbLE for engineering synthetic genome modules and chromosomes

Abstract Saccharomyces cerevisiae is closing-in on the first synthetic eukaryotic genome with genome-wide redesigns, including LoxPsym site insertions that enable inducible genomic rearrangements in vivo via Cre recombinase through SCRaMbLE (Synthetic Chromosome Recombination and Modification by LoxPsym-mediated Evolution). Combined with selection, SCRaMbLE quickly generates phenotype-enhanced strains by diversifying gene arrangement and content. Here, we demonstrate how iterative cycles of SCRaMbLE reorganises synthetic genome modules and chromosomes to improve functions. We introduce SCOUT ( S CRaMbLE C ontinuous O utput and U niversal T racker), a reporter system that allows sorting of SCRaMbLEd cells into high-diversity pools. Paired with long-read sequencing, SCOUT enables high-throughput mapping of genotype abundance and genotype-phenotype relationships. Iterative SCRaMbLE is applied here to yeast strains with a full synthetic chromosome and histidine biosynthesis modules. Five HIS module designs are tested, and SCRaMbLE is used to optimise the poorest performer. Our results highlight iterative SCRaMbLE as a powerful tool for data driven modular genome design.

ALDH18A1 has carcinogenic functions and regulates alternative splicing events of DNA repair-related genes in esophageal carcinoma cells

Photodynamics simulation insights into excited-state relaxation mechanisms via Z/E isomerization in para-amino substituted GFP chromophores

The ability of green fluorescent protein (GFP) chromophore and its derivatives to undergo cis–trans photoswitching behavior has been widely acknowledged as of great interest because of its emerging applications in optogenetics and optoelectronics. However, key aspects of the internal conversion process in the GFP chromophore derivatives remain largely unclear. Based on quantum chemical methods and on-the-fly nonadiabatic dynamics simulations, we investigated the ultrafast photoinduced cis–trans isomerization phenomenon in the para-amino (NH2-HBDI) derivative of the GFP chromophore, which is intrinsically non-fluorescent. We demonstrate that upon excitation to the excited (S1) state, there occurs nonselective progression along the distortion of exocyclic methine-bridged imidazolinone (I) and phenylamine (P) bonds, leading to ultrafast nonradiative relaxation via S1(1ππ*)/S0 internal conversion. This internal conversion process is facilitated by multiple S1/S0 conical intersections with dominant imidazolinone (ΦI) dihedral rotations. Our results provide insight into the effect of the amino group on the dynamics of fluorescent probes. Therefore, these observations contribute to a valuable understanding of photoinduced switching phenomena and find a relation between structure and dynamics.

Mechanistic analysis and kinetic profiling of Soai’s asymmetric autocatalysis for pyridyl and pyrimidyl substrates

Abstract Nonlinear effects in chemical reactions, coupled with amplifying catalysis, can lead to remarkable phenomena like spontaneous symmetry breaking, central to the origin of biological homochirality. Soai’s asymmetric autocatalysis is a prototypical reaction for this, where the enantiomeric excess of the product alcohol is amplified during alkylation of pyridyl and pyrimidyl carbaldehydes by diisopropylzinc. However, the complex equilibria and elusive intermediates make the mechanism difficult to clarify. Here we unravel the intricate dynamics of this reaction by in situ high-resolution mass spectrometry, kinetic analysis, and reaction profile simulations. We identify for both the pyrimidyl and the pyridyl systems transient hemiacetalate isopropyl zinc complexes, formed by the addition of the alcoholate product to the aldehyde, as key catalytic intermediates. These diastereomeric complexes enable dual stereocontrol, explaining the observed enantioselectivity. Our analysis confirms the structures of all intermediates and validates the autocatalytic cycle, offering insights into how substituent and structural variations influence reaction performance. This understanding guides the design of new, efficient asymmetric autocatalytic systems.

Metabolic dynamics of human external urethral sphincter myoblast differentiation and the effects of tricarboxylic acid cycle inhibition

Abstract Stress urinary incontinence commonly arises with aging or following prostatectomy, yet its underlying mechanisms remain unclear. To address this, we investigated the role of metabolic pathways—particularly the tricarboxylic acid (TCA) cycle—in the differentiation of human external urethral sphincter myoblasts. Immortalized sphincter cells (US2-KD) were induced to differentiate over 192 h. Metabolomic profiling using gas chromatography–mass spectrometry, along with pathway enrichment analysis, identified key metabolic changes. Inhibition of mitochondrial pyruvate transport with UK5099 markedly suppressed TCA cycle metabolites, including citrate, α-ketoglutarate, fumarate, and malate. This inhibition also significantly reduced MYH7 expression and intracellular adenosine triphosphate levels throughout the differentiation period. These results demonstrate that the TCA cycle plays a critical role in both energy metabolism and the differentiation of urethral sphincter myoblasts. This study is the first to suggest that impaired TCA cycle activity may contribute to the pathogenesis of Stress urinary incontinence and represents a potential therapeutic target. Our findings offer new insight into age-related metabolic decline associated with Stress urinary incontinence and support the development of therapies that combine metabolic modulation with regenerative approaches.

Extension of the Fermi–Amaldi functional to fractional electron number

The Fermi–Amaldi correction is a conceptually significant density-functional approximation with explicit dependence on the electron number N. This dependence raises the question of whether N should be treated as the integral of the total electron density for systems with noninteger (fractional) N. We answer this question negatively by observing that the Fermi–Amaldi functional is identical with the exact exchange functional for any number of fermions or bosons occupying the same spatial orbital and in systems where occupied orbitals have zero differential overlap. This conclusion is consistent with previous reports that the preservation of certain properties of N-dependent functionals requires treating N as a parameter. Our analysis also suggests that the Fermi–Amaldi functional is discontinuous within a given spin-channel of the total electron density and continuous on the boundaries between different spin-channels at N = 1. This implies that the jump discontinuity of the exact exchange–correlation potential observed at N = 1 is a correlation effect. The last conclusion is illustrated with numerical calculations.