Browse Articles

Hybrid Young’s double-slit experiment and differential evolution for enhanced photovoltaic parameter estimation

Hierarchical dynamic coding coordinates speech comprehension in the human brain

Speech comprehension involves transforming an acoustic waveform into meaning. To do so, the human brain generates a hierarchy of features that converts the sensory input into increasingly abstract language properties. However, little is known about how rapid incoming sequences of hierarchical features are continuously coordinated. Here, we propose that each language feature is supported by a dynamic neural code, which represents the sequence history of hierarchical features in parallel. To test this “hierarchical dynamic coding” (HDC) hypothesis, we use time-resolved decoding of brain activity to track the construction, maintenance, and update of a comprehensive hierarchy of language features spanning phonetic, word form, lexical–syntactic, syntactic, and semantic representations. For this, we recorded 21 native English participants with magnetoencephalography (MEG), while they listened to two hours of short stories in English. Our analyses reveal three main findings. First, the brain represents and simultaneously maintains a sequence of hierarchical features. Second, the duration of these representations depends on their level in the language hierarchy. Third, each representation is maintained by a dynamic neural code, which evolves at a speed commensurate with its corresponding linguistic level. This HDC preserves the maintenance of information over time while limiting destructive interference between successive features. Overall, HDC reveals how the human brain maintains and updates the continuously unfolding language hierarchy during natural speech comprehension, thereby anchoring linguistic theories to their biological implementations.

Integrated stimulation technology for ultra deep tight sandstone gas reservoirs with ultra low permeability in Sichuan Xujiahe formation

Assortative breeding experiment in a songbird suggests telomere length is determined during early life rather than at conception

Abstract Telomere length (TL) early in life often shows high heritability and may predict telomere shortening later in life and life expectancy. Yet, there is limited data about what influences TL and TL change at early developmental stages. It is debated whether early-life TL is determined at conception or shaped by early environmental conditions. Here, we investigate whether TL and telomere shortening are set close to conception. We assortatively paired zebra finches ( Taeniopygia guttata ) based on their TL when nestlings, forming two parental pair groups with either ‘short’ or ‘long’ TL. We then measured TL in the offspring of these pairs at the embryo and nestling stages. In embryos, TL did not differ between offspring from the two parental pair groups. However, in nestlings, particularly in sons, offspring TL matched parental TL. Our results suggest that early-life TL itself is not determined at conception. Instead, telomere shortening rate before and just after hatching appears to determine early postnatal TL. These findings highlight that early development is critical for telomere shortening during early life stages and that it may be a key process underlying the similarity in early-life TL between parents and offspring, potentially affecting telomere dynamics throughout life.

Virulence hierarchies within the <i>Mycobacterium tuberculosis</i> complex

The Mycobacterium tuberculosis complex (MTBC) includes M. tuberculosis ( M. tb ), the primary cause of human tuberculosis, M. bovis, the classical zoonotic pathogen and cause of bovine tuberculosis, and M. orygis, a recently recognized multihost pathogen. Given that M. tb, M. bovis, and M. orygis pose significant threats to the health of humans and animals, we sought to understand fundamental differences in pathogenicity among these closely related organisms. Building upon historical observations, we conducted a comparative virulence assessment of these pathogens using both bovine and murine infection models. Holstein calves were infected via aerosol with M. tb, M. bovis, or M. orygis , and pathology was analyzed through macroscopic and microscopic assessments of lungs and lymph nodes, along with quantitative tissue bacterial burden measurements. In C57BL/6 mice, we compared virulence using three readouts, namely survival, lethal dose determination, and detailed pathological assessments. Despite genomic similarity, animal-adapted MTBCs consistently showed dramatically enhanced virulence compared to M. tb with distinct immunopathology and, in the murine model, mortality within 24 days. Using gene disruption studies guided by proteomic comparisons, we determined that these infection outcomes were dependent on shared (ESAT-6) and lineage-associated (MPT70) virulence factors, the route of infection, and prior infection or immunization. Our findings reveal unexpected virulence hierarchies within the MTBC, with fundamental and translational implications for tuberculosis research.

Harnessing artificial intelligence for environmental sustainability via human capital and renewable energy

Atomic engineering of intrinsic permanent magnetism in MnBi

Broadband topological transitions in twisted elastodynamic metasurfaces

In the last decade, the connection between physics and topology has resulted in the discovery of several new phenomena. A celebrated example is the field of topological insulators [X.-L. Qi, S.-C. Zhang, Rev. Mod. Phys. 83 , 1057–1110 (2011)]., in which topological quantities describing the bulk medium response in reciprocal space dictate the presence of protected transport states at the boundary of a finite sample. Broken symmetries in the microscopic structure of a material play a prominent role in determining its topological features relevant to these phenomena. As another landmark phenomenon driven by broken symmetries, twistronics leverages the rotation angle between coupled layers to control in extreme ways the dispersion topology, leading to flat-band superconductivity [Y. Cao et al. , Nature 556 , 43–50 (2018)] and topological transitions for polaritons [G. Hu et al. , Nature 582 , 209–213 (2020)]. Here, we apply these concepts to elastodynamic waves, and exploit the twist degree-of-freedom to control broken symmetries in the microscopic structure of elastic metasurfaces, demonstrating extreme wave control. We predict and experimentally demonstrate topological transitions within twisted elastodynamic metasurfaces, which we harness for broadband, reconfigurable, and robust manipulation of phonons. Our twist-elastic approach opens alternative directions in microelectronics, microfluidics, and ultrasound sensing, leveraging precise multifunctional engineering of mechanical vibrations of relevance to many modern technologies.

Analysis of the correlation between PM2.5 and PM10 concentrations and the epidemiology of severe Mycoplasma pneumoniae in the PICU

p-GaN source integrated GaN/AlGaN/GaN double heterojunction field-effect transistor (FET) for next-generation electronic applications

TMEM16F phospholipid scramblase regulates tumorigenesis by modulating the tumor immune microenvironment

The immunosuppressive tumor microenvironment enables immune evasion through mechanisms beyond canonical immune checkpoints. While phosphatidylserine (PS) externalization coordinates apoptotic clearance under physiological conditions, tumors hijack this mechanism through apoptotic mimicry to subvert antitumor immunity. Here, we identify TMEM16F, a calcium-activated phospholipid scramblase, as a driver of tumor-intrinsic PS externalization. TMEM16F-mediated PS scrambling polarized macrophages to an immunosuppressive M2 phenotype, which promotes TGF-β1 secretion and regulatory T cell expansion to suppress cytotoxic lymphocytes. Genetic ablation of TMEM16F abolished PS exposure, systemically reprogrammed the tumor microenvironment and primary immune organs toward immune activation, and suppressed tumor growth across cancer models. Pharmacological scramblase inhibition produced these effects, demonstrating therapeutic potential. Our findings establish TMEM16F-dependent phospholipid scrambling as a critical immune evasion axis and propose targeting this pathway for cancer treatment.

Tracing old carbon sources in Hungarian nectar samples using radiocarbon analysis

Phytosphingosine, a sphingolipid isolated from fungal endophyte Penicillium oxalicum, exerts cytotoxic effects against breast cancer cells and shows blood compatibility

Shapes of ideal stalagmites

Stalagmites are isolated columns of calcium carbonate growing on a cave floor; their growth is driven by the constant dripping of supersaturated solutions from the roof of the cave. In this paper, we derive a closed-form expression for the shape of a steadily growing stalagmite. Our analysis gives rise to three distinct shapes, all of them observable in nature, with the shape characterized by a single dimensionless parameter. Transitions between different shapes occur at a specific value of this parameter, with additional selection rules determining the shape and size of stalagmites evolving under specific cave conditions. Our theory shows that the stalagmite shape influences the 13 C isotope shifts, which are an important source of paleoclimatic information.

Ultrasonic processing in rabbit leg braising advances microstructure, water retention, and flavor development

Intelligent optimization of track and field teaching using machine learning and wearable sensors

TCR signal–enhancing mutation alters lipid metabolism of thymocytes and impairs antitumor immunity of mature T cells

The T cell receptor (TCR), a master regulator of adaptive immunity, serves as a molecular transducer that converts antigen recognition into precisely modulated intracellular signals, orchestrating both T cell development and effector functions. In this study, we leveraged a germline CD3ε I173A mutation, a previously characterized alteration that amplifies TCR signaling through the disruption of inhibitory lipid interactions, to dissect how thymocyte-intrinsic TCR signaling amplification influences the fate of mature T cells. Remarkably, thymic double-positive cells in CD3ε I173A mice with altered TCR repertoires demonstrated a significant downregulation of the phosphatidylserine decarboxylase homolog gene AC149090.1 . This modulation triggered a comprehensive rewiring of lipid metabolic pathways, establishing a systemic compensatory mechanism to counterbalance excessive TCR signaling. These metabolic adaptations culminated in functionally compromised mature T cells, characterized by diminished activation potential, reduced proliferative capacity, and impaired antitumor efficacy in CD3ε I173A mice. Our results underscore the critical role of thymic TCR signaling in T cell development for sustaining immune homeostasis and orchestrating mature T cell functionality, unveiling the lipid metabolic plasticity during thymocyte development that acts as a critical regulatory checkpoint for maintaining immune homeostasis.

Spatiotemporal modeling and mapping of traffic crashes using R programming and GIS: a case study of Bole sub city, Addis Ababa, Ethiopia

Robust IoT security using isolation forest and one class SVM algorithms

Abstract The rapid growth of cloud computing and the Internet of Things (IoT) has increased the exposure of IoT devices to cyber-attacks due to their resource limitations and lack of standardized security protocols. This paper presents a robust anomaly detection framework for IoT networks using two unsupervised machine learning models: Isolation Forest (IF) and One-Class Support Vector Machine (OCSVM). Leveraging the TON_IoT dataset, we conduct a comparative evaluation of IF, OCSVM, and a lightweight fusion approach called Combined Scoring Anomaly Detection (CSAD). Results show that OCSVM achieves superior precision, recall, and accuracy compared to both IF and CSAD. To ensure reliability, we apply Random Forest-based feature importance analysis, fivefold cross-validation and hyperparameter tuning. Model resilience is further examined under adversarial label-flip poisoning attacks and interpretability is enhanced through Local Interpretable Model-Agnostic Explanations (LIME). The findings demonstrate that lightweight unsupervised algorithms can provide effective, low-resource anomaly detection for modern IoT environments.

Oil–water interfaces drive gold precipitation via microdroplet chemistry in thermal geological systems

Sedimentary basins host high-grade gold mineralization at intersections of auriferous hydrothermal fluids and hydrocarbons. However, the precise mechanism of native gold formation associated with organic matter remains poorly understood. Here, we investigate gold precipitation at oil–water interfaces through in situ thermal experiments using various combinations of oil and HAuCl 4 -bearing solutions. Our results reveal that gold particles form spontaneously following the extensive generation and evolution of water microdroplets at oil–water interfaces at temperatures of 140 to 400 °C. We propose that electrons (e − ), released from the conversion of hydroxide ions (OH − ) to hydroxyl radicals (·OH) in water microdroplets, together with H atoms (·H) formed through electron transfer involving H 3 O + , and spontaneously generated H 2 O 2 from·OH recombination, drive the reduction of Au 3+ to Au 0 . The atomic gold progressively aggregates into Au 0 clusters and Au nanoparticles (AuNPs), ultimately forming micrometer-scale gold particles and wires. This precipitation process occurs within minutes at temperatures above 350 °C and within hours below 200 °C. The experimentally produced gold particles exhibit textures like those in natural ore deposits. This interfacial microdroplet–induced mechanism provides a unique perspective on native gold formation in hydrocarbon-rich geosystems. Beyond its geological significance, this mechanism offers a potentially simplified approach for gold recovery from electronic waste without the need to introduce complex adsorbents or reducing agents into the waste stream.