Browse Articles

FtsZ-mediated spatial–temporal control over septal cell wall synthesis

FtsZ, the tubulin-like GTPase, is the central organizer of the bacterial divisome, a macromolecular complex that synthesizes new septal cell wall (made of septal peptidoglycan, sPG) to allow cell wall constriction and cytokinesis. In Escherichia coli , it was shown that 1) FtsZ recruits all essential divisome proteins to the septum, including the core sPG synthase complex, FtsWIQLB, and its activator, FtsN; 2) FtsWIQLB must complex with FtsN to be activated to synthesize sPG under the wildtype background; and 3) the Brownian ratcheting by treadmilling FtsZ polymers drives the directional movements of sPG synthase proteins along the septum circumference; and 4) FtsZ is essential for the early stage, but dispensable for the late stage of cell wall constriction. However, it remains unclear how FtsZ spatial–temporally organizes the divisome for robust cell wall constriction during cytokinesis. Combining theoretical modeling with experiments in E. coli , we show that at the early stage during cell division, the Brownian ratcheting by FtsZ treadmilling acts both as a template to corral FtsWIQLB and FtsN into close contacts for FtsWIQLB-FtsN complex formation and as a conveyor to maximally homogenize the septal distribution of sPG synthesis activities to avoid uneven cell wall constriction. When the septum constricts progressively, the FtsN septal density increases via binding to denuded sPG (dnG) and serves as the template to activate FtsWIQLB for continued sPG synthesis, rendering FtsZ dispensable. Our work suggests an overarching framework for how FtsZ spatial–temporally regulates septal cell wall constriction, in which different bacteria species may operate in various parameter regimes to meet their distinct functional requirements.

Optimizing machine learning for network inference through comparative analysis of model performance in synthetic and real-world networks

SFMANet: A Spatial-Frequency multi-scale attention network for stroke lesion segmentation

Rising surface salinity and declining sea ice: A new Southern Ocean state revealed by satellites

For decades, the surface of the polar Southern Ocean (south of 50°S) has been freshening—an expected response to a warming climate. This freshening enhanced upper-ocean stratification, reducing the upward transport of subsurface heat and possibly contributing to sea ice expansion. It also limited the formation of open-ocean polynyas. Using satellite observations, we reveal a marked increase in surface salinity across the circumpolar Southern Ocean since 2015. This shift has weakened upper-ocean stratification, coinciding with a dramatic decline in Antarctic sea ice coverage. Additionally, rising salinity facilitated the reemergence of the Maud Rise polynya in the Weddell Sea, a phenomenon last observed in the mid-1970s. Crucially, we demonstrate that satellites can now monitor these changes in real time, providing essential evidence of the Southern Ocean’s potential transition toward persistently reduced sea ice coverage.

Prediction of blastocyst development using cleavage-stage embryo metrics and maternal age

The epigenetic impacts of pubertal acceleration following early caregiver disruptions

A stable caregiving environment early in life is essential for children’s development, and disruptions have the potential to impact biological processes. Using data from the Bucharest Early Intervention Project, we examined a developmental cascade model in which shifts in pubertal tempo following early caregiving disruptions come at an epigenetic cost. Among 115 individuals, all of whom experienced severe deprivation early in life, we tracked caregiving disruptions across childhood; assessed pubertal timing and tempo across adolescence; and quantified the pace of cellular aging via telomere erosion across the second decade of life. We demonstrate that a greater number of caregiving disruptions is associated with delayed pubertal timing and an acceleration of pubertal tempo. In turn, accelerations in pubertal tempo are associated with significantly greater telomere erosion across time. A formal mediation model indicated that greater caregiving disruptions during childhood predicted greater telomere erosion through an acceleration of pubertal tempo. By documenting the impact of caregiving disruptions on pubertal development and ultimately biological aging, these findings highlight the importance of the stability of the caregiving context and the critical need to ensure that organizations caring for vulnerable children establish programs and policies to minimize unnecessary disruptions.

Outcome of universal newborn hearing screening conducted in three referral hospitals in Cameroon

Jurassic constraints on the chaotic Mars–Earth eccentricity cycle linked to the volcanically induced Jenkyns event

Solar system gravitational interactions are embedded in Earth’s record of climate, providing a way to bypass the 60 Myr limit imposed by chaos. Presently with a 2.4 Myr period, the Mars–Earth beat cycle of orbital perihelion frequencies is particularly sensitive to chaotic diffusion, potentially varying by more than a million years. Early Mesozoic (252 to 145 Ma) strata provide some constraints on this cycle, with evidence of a swing through most of the solution space from 1.8 Myr at 210 Ma to 2.5 Myr at 190 Ma and back to 1.6 Myr at 180 Ma. However, only the 1.8 Myr cycle is corroborated by geochronologic data and the 1.6 Myr period is disputed. Here, we show that variations in land-plant-dominated stable carbon isotopic ratios (δ 13 C org ) from the lacustrine, paleo-high-latitude Sangonghe Formation (Junggar Basin, northwestern China), reveal at least three 1.6 Myr Mars–Earth beat cycles centered at 183 Ma, tracking atmospheric CO 2 isotopic composition in Earth’s exchangeable carbon reservoirs. Furthermore, the middle cycle includes the famous Jenkyns Event, expressed here by poleward migration of cheirolepidaceous conifers driven by CO 2 warming from the Karoo-Ferrar large igneous province (LIP). Our data do not, however, support major, LIP-triggered input of isotopically light carbon and instead support CO 2 amplification of local processes via warming and ecosystem change. Although requiring additional independent geochronological support, Sangonghe data help provide empirical constraints for filtering orbital solutions, tightening initial conditions, and testing gravitational models, as well as showing how extrinsic cyclical processes interact with a tectonic event, the Karoo-Ferrar LIP.

Fabrication of a sponge-like protein based hydrogel incorporating fluconazole against Candida species as a potential treatment for vulvovaginal candidiasis infection

A transcriptomic, proteomic, and functional genetic atlas dissects neurofibromin function in the peripheral nervous system

The NF1 tumor suppressor gene is recurrently mutated in human cancers and is associated with the neurofibromatosis type 1 (NF-1) cancer predisposition syndrome. NF1 encodes neurofibromin, a Ras guanosine triphosphate (GTPase) activating protein that negatively regulates Ras signaling. NF1 mutation accordingly leads to Ras misactivation and downstream activation of RAF/MEK/ERK signaling, leading to the approval of the MEK inhibitor selumetinib for NF-1 associated peripheral nervous system (PNS) tumors. However, how NF1 loss modifies response to selumetinib and the utility of targeting additional upstream inputs or downstream outputs of Ras these tumors remain unclear. Here, we perform RNA-sequencing, phosphoproteomic, pharmacologic, and proximal proteomic analysis across a panel of CRISPR interference immortalized peripheral nerve (iPN) cells to systematically dissect the function of neurofibromin loss. Small guide NF1 (sg NF1 ) repression is sufficient to increase Ras GTP levels and alter gene expression to promote cell proliferation and dedifferentiation, with sg NF1 iPNs showing decreased sensitivity to selumetinib due to altered feedback regulation to Ras/RAF/MEK/ERK. Upstream small guide PTPN11 (sg PTPN11 ) repression leads to the inverse gene expression signature, decreasing cell proliferation and promoting differentiation, and sg PTPN11 iPNs are more sensitive to selumetinib. However, upstream sonof sevenless 1 inhibition shows limited efficacy in iPNs due to compensation by SOS2. Finally, proximal proteomics reveals Kirsten rat sarcoma virus (KRAS), but not Harvey rat sarcoma virus (HRAS) or neuroblastoma Ras viral oncogene homolog (NRAS), associates with neurofibromin in iPN cells, and pan-KRAS inhibition is sufficient to block ERK activation and CDK1/2 activation in NF1 mutant cells, suggesting blocking KRAS may be a therapeutic approach for NF1 mutant PNS tumors.

Investigation of structural, optical, magnetic, and electrochemical properties of La1 − xAgxFe0.5Mn0.5O3−δ perovskites

Combined exercise and Hawthorn protect against learning impairments and hippocampal damage from trimethyltin neurotoxicity in rat

The importance of scientists’ intellectual humility for communicating effectively across ideological and identity-based divides

Growing identity-based and partisan gaps in confidence in scientists and scientific institutions call for novel approaches to science communication. In this perspectives piece, we focus on the need for greater intellectual humility (i.e., willingness to revise one’s views and admit that one might be wrong) among social scientists, who are met with particularly high levels of skepticism from the public. We begin with an overview of research demonstrating that when scientists’ identities or ideologies align (or are perceived to align) with those of the public, trust in science increases. We then highlight intellectual humility as a potential tool for cultivating trust in the social sciences even when social scientists’ and the public’s identities or ideologies do not match. Specifically, intellectual humility among social scientists predicts less bias toward one another’s research and hence may increase the diversity of perspectives to which the public is exposed and shift public perceptions of social scientists. We conclude with a discussion of how to foster intellectual humility in science communication, broadly defined.

The impact of insufficient sleep on dietary choices and physical activity behaviors: evidence from a randomized cross-over trial

Ternary recombination of excited Ar+(2P1/2) ions. II. Internal states of nascent Ar2+ and a novel view on the elementary recombination processes

Electronic states and internal energies of stabilized Ar2+ ions resulting from ternary collisions of Ar+(P1/22) with argon atoms are analyzed at close to thermal conditions (E/N = 1 Td). For the former, a quasiadiabatic behavior has been observed with the electronic states of the stabilized dimer ions almost exclusively asymptotically correlating to the P1/22 state of the colliding atomic ion. Transitions to the electronic states with the P3/22 asymptote are of only marginal importance. The internal energies of stabilized dimer ions are found around the P1/22 dissociation limit, with a non-negligible number of the ions formed in rotationally metastable states. The calculations performed for Ar+(P1/22) are compared with selected data obtained for Ar+(P3/22). Qualitatively, the same behavior is seen for both types of ions. The results obtained for both types of Ar+ ions lead us to the conclusion that the simple picture of the ternary recombination of Ar+ ions generally shared in the literature will have to be replaced by a more complex one.

Fused federated learning framework for secure and decentralized patient monitoring in healthcare 5.0 using IoMT

Abstract Federated Learning (FL) enables artificial intelligence frameworks to train on private information without compromising privacy, which is especially useful in the medical and healthcare industries where the knowledge or data at hand is never enough. It paved the way for a substantial amount of study because of the high degree of communication efficacy it possessed, which is connected to dispersed training issues. The major goal of this paper is to shed light on how FL approaches might be adapted and put to use in several aspects of healthcare, including medicine discovery, medical assessment, digital health management, and the forecasting and identification of disease. This article presents a comprehensive and in-depth study of the data about fused federated learning in healthcare version 5.0. The purpose of this research is to develop a Healthcare 5.0 monitoring system by utilizing a fused federated learning approach integrated with RTS-DELM. It gives medical practitioners the ability to monitor patients through the use of various medical sensors and to take remedial action at regular intervals. The approach is shown to be successfully improved by the use of the recommended system, which is intended for healthcare monitoring. This paper introduces a novel framework leveraging Fused Federated Learning (FFL) integrated with IoMT devices aimed at securely monitoring patient health data in a decentralized manner. This study introduces a novel integration of Real-Time Sequential Deep Extreme Learning Machine (RTS-DELM) and Fused Federated Learning (FFL) for secure and decentralized chronic kidney disease diagnosis within Healthcare 5.0. The proposed approach efficiently aggregates data from distributed Internet of Medical Things (IoMT) devices, enhancing predictive accuracy while maintaining patient privacy. Experimental validation demonstrates significant improvements, achieving an accuracy rate of 98.21%, thereby showcasing superior performance over existing federated learning methodologies.

Are nonequilibrium effects relevant for chiral molecule discrimination?

Sensing and discriminating between enantiomers of chiral molecules remains a significant challenge in the design of sensor platforms. In the case of chemoresistive sensors—where detection relies on changes in electrical response upon analyte adsorption—the sensor substrate is typically functionalized with chirality-sensitive molecular receptors. In this computational study, we investigate whether a chirality-blind substrate, such as a graphene nanoribbon, is still capable of discriminating between enantiomers. To this end, we employ a density-functional parameterized tight-binding method combined with nonequilibrium Green’s functions. For a small set of chiral amino acids, we demonstrate that accounting for the nonequilibrium response of the device leads to significant differences in the electrical currents of enantiomeric pairs of the order of tens of nanoamperes. This effect is further amplified when structural fluctuations of the device’s active region are considered (≈1–2 μA). Moreover, we propose new quantum-mechanical quantities for enantioselective discrimination in molecular sensors, with an emphasis on binding features and property–property correlations. Therefore, our work demonstrates the significance of nonequilibrium effects in chiral discrimination, laying the foundation for future investigations addressing the design of chiral molecular sensors.

Enhanced particle swarm optimization for feature selection in SVM-based Alzheimer’s disease diagnosis

Synthesis, crystal structure, and physical properties of ThRuSn with a distorted kagome structure

We report the synthesis and comprehensive analysis of a new ternary compound, ThRuSn, featuring a distorted kagome structure composed of Th atoms. The compound crystallizes in a ZrNiAl-type structure with lattice parameters a = b = 7.4599(6) Å and c = 4.1306(3) Å. It displays metallic behavior, low magnetoresistance, and paramagnetism, as evidenced by electrical resistivity and magnetic susceptibility measurements. Hall effect measurements reveal that the carrier type follows a single-band model and is predominantly characterized by hole type. The electronic coefficient, γe = 3.6 mJ K−2 mol−1, was derived from low-temperature specific heat. Furthermore, first-principle calculations suggest that the electron states near the Fermi energy are primarily influenced by the Ru and Th states. The electronic band structure exhibits Dirac-like crossings and van Hove singularities at the M and K points, suggestive of potential topological properties. This study contributes to the development of new material platforms at the forefront of ternary equiatomic intermetallic compounds and distorted kagome metal research.

Bee pollen as a source of phenolic compounds in potato snacks

Abstract The study examined the effects of adding bee pollen to potato snacks on their chemical composition, antioxidant properties, and sensory characteristics. Bee pollen from six different sources varied in phenolics and flavonoid content and composition, antioxidant activity and color. The four bee pollens with the highest content of bioactive compounds were used in the preparation of potato snacks obtained by frying extruded pellets with 1, 3 and 5% of bee pollen. During snack production, total phenolic and flavonoid contents decreased by 4.76–65% and 69–80%, respectively, while antioxidant activity was reduced by 9–72% depending on the used level of addition and type of bee pollen. Despite this, snacks enriched with 1–5% bee pollen exhibited significantly higher levels of phenolics (1.3–2.6 times), flavonoids (2.0–4.8 times), and antioxidant capacity (ABTS•+ 1.6–3.7 times, DPPH• 1.1–1.4 times, FRAP 1.8–5.6 times) compared to controls. The highest antioxidant capacity was observed in snacks with 5% rapeseed and multifloral bee pollen. Sensory analysis highlighted snacks with 3% multifloral bee pollen as those with the highest quality. This research has demonstrated that bee pollen can be a promising fortification ingredient, improving the nutritional value of snacks while masking its naturally bitter taste, if used in relatively low percentages (< 5%). These findings supported the development of healthier snack options enriched with bee pollen for the functional food market.