Browse Articles

Sensitivity characteristics of the Hirota–Maccari system in nonlinear materials

Reprogramming feedback strength in gibberellin biosynthesis highlights conditional regulation by the circadian clock and carbon dioxide

The phytohormone gibberellin (GA) is an important regulator of plant morphology and reproduction, and the biosynthesis and distribution of GA in planta is agriculturally relevant to past and current breeding efforts. Tools like biosensors, extensive molecular genetic resources in reference plants and mathematical models have greatly contributed to current understanding of GA homeostasis; however, these tools are difficult to tune or repurpose for engineering crop plants. Previously, we showed that a GA-regulated Hormone Activated CAS9-based Repressor (GAHACR) functions in planta . Here, we use GAHACRs to modulate the strength of feedback on endemic GA regulated genes, and to directly test the importance of transcriptional feedback in GA signaling in the model eudicot Arabidopsis thaliana. We first adapted existing mathematical models to predict the impact of targeting a GAHACR to different nodes in the GA biosynthesis pathway, and then implemented a perturbation predicted by the model to lower GA levels. Specifically, we individually targeted either the biosynthetic gene GA20 oxidase ( GA20ox ) or the GA receptor GID1, and characterized primary root length, flowering time and the transcriptome of these transgenic lines. Using this approach, we identified a strong connection between GA signaling status and the circadian clock, which can be largely attenuated by elevated carbon dioxide levels. Our results identify a node in the GA signaling pathway that can be engineered to modulate plant size and flowering time. Our results also raise concerns that rising atmospheric CO 2 concentration are likely to reverse many of the gains of Green Revolution crops.

Ultrastrong MXene composite fibers through static-dynamic densification for wireless electronic textiles

Abstract Inherent transverse wrinkles and resulting voids between MXene (Ti 3 C 2 T x ) nanosheets hinder the preservation of their intrinsic mechanical and electrical properties in macroscopic fibers. Here, we demonstrate a controllable and continuous method for kilometer-scale fabrication of ultrastrong MXene composite fibers by utilizing static filling with short carbon nanotubes combined with dynamic thermal drawing using polylactic acid to bridge MXene nanosheets through hydrogen bonds. The resulting composite fibers achieve a record tensile strength of ~941.5 MPa and an electrical conductivity of ~3899.0 S cm −1 , with an even higher conductivity of ~12,836.4 S cm −1 for the inner MXene fiber. This static-dynamic densification strategy significantly reduces voids with a low porosity of ~4.2% and enhances the nanosheet orientation factor to ~0.945. The embroidered smart textiles enable long-range, battery-free wireless health monitoring, body-coupled remote drone operation, and assisted communication with sustained mechanical durability. This versatile strategy offers a general pathway to fabricate high-performance functional fibers.

Subsistence fishing patterns near food deserts

Fisheries are critical for sustaining waterfront communities. However, subsistence fishing is not well understood in the United States, despite its potential contributions to health and culture. We piloted a multivariable construct to classify subsistence vs. nonsubsistence fishers, identified the strongest predictor of participating in this practice, and tested for differences in place-based fishing motivations, behaviors, and community sharing. Among shore-based fishers in coastal Alabama, lower household income was the most powerful predictor of subsistence fishing. Subsistence fishers held more fishing motivations, targeted more specific fish groups, were more efficient in catching and keeping fish, and more frequently shared fish across social groups. Informed by these findings, we discussed management strategies to addressopportunities and barriers for shore-based subsistence fishing in coastal Alabama. More broadly, the framework piloted here offers a pathway to integrate subsistence fisheries into management using place-based evidence.

Urban flood disaster prevention, control, and rescue using edge computing and the resilience concept

Computation suggests that the cell adhesion sub-proteome is enriched for sites of pH-dependence and charge burial

Prediction of protein pH-dependence is generally made for individual proteins or pathways, and is also increasingly being used to aid protein functional design. Combining high-throughput pKa prediction methods with AlphaFold models allows pH-dependence to be studied across a proteome. Here, two methods and a variety of features for detecting pH-dependence and charge burial that is physiologically relevant, have been applied to human proteins. Predictions are effective for a small benchmark subset of well-characterised proteins and, more broadly, identify an overlap between features associated with pH-dependence and enzymes and transporters. The most informative filters are those describing relatively buried ionisable groups, with pKas close to neutral pH and/or involvement in highly-coupled charge networks. The question is addressed of which human proteins not annotated as enzymes or transporters, are predicted to have these features of predicted pH-dependence and/or charge networking. A striking feature from gene ontology analysis of those proteins is a predicted enrichment at the cell periphery, in particular an association with cell adhesion, including protein families not currently known to exhibit pH-dependence. Gene ontology classifications that are depleted for proteins with buried charge networks and/or predicted functional pH-dependence, include some associated with ribosomal and nuclear structure. This overall result suggests a possible general resilience of some key processes to pH fluctuations, whilst not precluding specific instances where signalling pathways have evolved responses to pH changes. A drawback of the study is restriction to protomer models, thus omitting groups that mediate pH-dependence through burial at an interface. However predictions are already notable, with their details (including molecular origins) provided for experimental design.

Structural basis of undecaprenyl phosphate glycosylation leading to polymyxin resistance in Gram-negative bacteria

Precancer exercise capacity and metabolism during tumor development coordinate the skeletal muscle–tumor metabolic competition

Higher exercise capacity and regular exercise training improve cancer prognosis at all stages of disease. However, the metabolic adaptations to aerobic exercise training that mediate tumor–host interactions are poorly understood. Here, we demonstrate that voluntary wheel running slows tumor growth and repartitions glucose uptake and oxidation to skeletal and cardiac muscle and away from breast and melanoma tumors in mice. Further, prehabilitation induces repartitioning of glucose metabolism in obese mice: Uptake and oxidation of glucose are enhanced in skeletal and cardiac muscle, and reduced in tumors. These increases in muscle glucose metabolism and reductions in tumor glucose metabolism, correlated with slower tumor progression. Using [U- 13 C 6 ] glucose infusion, we show that exercise increases the fractional contribution of glucose to oxidative metabolism in muscle while reducing it in tumors, suggesting that aerobic exercise shifts systemic glucose metabolism away from the tumor microenvironment and toward metabolically active tissues. Transcriptional analysis revealed downregulation of mTOR signaling in tumors from exercised mice. Collectively, our findings suggest that voluntary exercise may suppress tumor progression by enhancing host tissue glucose oxidation and limiting tumor glucose availability, supporting a model in which exercise-induced metabolic competition constrains tumor energetics.

MGWO-CNN: hyperparameter optimization of CNN classifier for cervical cancer detection using Modified Grey Wolf Optimizer

Trends and factors associated with pneumonia mortality at Buea Regional Hospital in Cameroon from 2020 to 2023

Background Pneumonia cases and associated deaths remain a public health concern necessitating ongoing efforts in prevention, diagnosis, and treatment. This study was aimed at identifying the trend of pneumonia, case fatality rate and factors associated with pneumonia mortality at the Buea regional hospital from 2020 to 2023. Methods In this retrospective study, data was collected from all available and complete adult inpatient/outpatient hospital records from 2020 to 2023 at Buea regional hospital. Only patients clinically and radiologically diagnosed with pneumonia (excluding TB and COVID-19) were considered for this study. Data was analyzed using SPSS with statistical significance set at p < 0.05. Results After reviewing 18,805 entries/records, 746 files corresponding to 746 patients (59.5% females) diagnosed with pneumonia were retained with mean age of 54.7 ± 19.2 years. There was a fluctuating trend in cases across the years with 2021 generally having higher values. There was a decreasing trend in case fatality rate across the years (2020: 17%, 2021:24%, 2022:8%, 2023:6%) with an overall case fatality rate of 13.7%. Being hospitalized for ≤10 days (aOR: 10.14, CI: 2.31–44.52, p = 0.002) and not being treated with amoxicillin-clavulanic acid (aOR: 3.33, CI: 1.43–7.75, p = 0.005) were significantly associated with pneumonia mortality. Conclusion Although the number of pneumonia cases fluctuated over time, they remained consistently present across all months from 2020 to 2023, highlighting the year-round nature of pneumonia transmission and its endemicity in the Buea Health District. Being hospitalized for less than 10 days and not using amoxicillin-clavulanic acid for treatment were risk factors of pneumonia mortality. These findings underscore the importance of timely diagnosis and empiric treatment with guideline recommended agents such as amoxicillin–clavulanic acid so as to reduce pneumonia mortality in the Buea regional hospital.

Biguanide-functionalized peptide mimics effectively combat drug-resistant ESKAPE pathogens and meningitis

Barrierless nucleation in glassy precursors drives zeolite formation

Zeolites are crystalline, microporous silicates widely used in catalysis and separations, yet the molecular mechanisms of their formation remain unresolved. Experiments indicate that hydrothermal synthesis of silica zeolites from clear solution proceeds through amorphous nanoaggregates that gradually develop zeolite order in an apparently continuous amorphous to crystal transformation. Here, we combine molecular simulations with advanced algorithms that identify zeolite order and computer vision to elucidate the pathway from clear solution to zeolite nanocrystal. We show that at conditions of hydrothermal synthesis of silica zeolites, the transformation of precursor aggregate into zeolite is not limited by nucleation barriers but by the slow dynamics of reorganization in the glassy precursor matrix. The negligible nucleation barriers result in spinodal-like crystallization that leads to a gradual formation of a mosaic of small crystallites that explain the seemingly continuous character of zeolite crystallization and the catalytic activity of X-ray amorphous, protozeolites and embryonic zeolites. We find that zeolite-like porosity and short-range order emerge early within glassy precursors, well before crystallinity is detected in transmission electron microscopy (TEM) images or X-ray diffraction. The nanoaggregate’s temperature-size phase diagram reveals a convergence of the zeolite–amorphous equilibrium and maximum crystallization rate at ~3 nm diameter nanoparticle diameters and ~200 °C. This convergence signals the termination of the first-order amorphous-to-zeolite transition. Our results provide a unifying framework for understanding nucleation of silica zeolites from solution and suggest that barrierless nucleation may govern the formation of other nanoparticle systems, including minerals and oxides synthesized far below their bulk melting points.

A kinematic-and-muscular modulation strategy for FES-assisted upper limb rehabilitation: a feasibility study

Trajectories of disability and influence of contextual factors among adults aging with HIV: Insights from a community-based longitudinal study in Toronto, Canada

Background Individuals aging with HIV may experience disability that is multidimensional and evolving over time. Our aims were to characterize the longitudinal trajectories of disability and to investigate how intrinsic and extrinsic contextual factors influence dimensions of disability over an eight-month period among adults aging with HIV. Methods We analyzed longitudinal observational data from a community-based study in Toronto, Canada, where adults aging with HIV completed self-reported questionnaires over eight months (five time points). We measured disability using the Short-Form HIV Disability Questionnaire (SF-HDQ), which included six dimensions: physical, cognitive, mental-emotional health challenges, uncertainty, difficulties with day-to-day activities, and challenges to social inclusion. Higher SF-HDQ scores (range: 0–100) indicate greater severity of disability. We assessed intrinsic (age, gender, education, living status, number of comorbidities, mastery) and extrinsic (stigma, social support) contextual factors using baseline self-reported questionnaires. Latent class growth analysis was performed to identify distinct disability trajectories within each of the six dimensions. Multinomial logistic regression models were used to assess the influence of contextual factors on the disability trajectories. Results Of 108 participants, 89% identified as men with a mean age of 50.6 years (standard deviation ±10.9). We identified three disability trajectories: low, medium, and high disability severity in the physical, mental-emotional, and day-to-day activities dimensions. Four trajectories: low, medium-low, medium-high, and high disability severity were in the cognitive, uncertainty, and social inclusion dimensions. Factors such as higher self-mastery and social support were associated with lower disability trajectories, whereas greater number of comorbidities and stigma were associated with more severe disability trajectories over time. Conclusion Disability experiences among adults aging with HIV included three or four distinct trajectories with considerable heterogeneity over time. Information on contextual factors may be helpful for informing interventions and supports that mitigate disability among adults aging with HIV.

An outer membrane vesicle vaccine prevents lung pathology in a macaque model of pneumonic melioidosis

Tppp3 determines basal body positioning and identity of respiratory cilia via microtubule assembly and sphingolipid homeostasis

Cilia are hair-like organelles that protrude from the cell surface. In mammals, tracheal multiciliated cells (MCCs) play an important role in elimination of hazardous microorganisms by driving a unidirectional mucus flow. Although uniform orientation of ciliary beating is critical for the unidirectional flow, it remains unknown how MCCs establish uniform orientations and maintain identities of hundreds of ciliary membranes. This study focuses on investigating the roles of Tubulin Polymerization Promoting Family Member 3 (Tppp3) in MCC function. We generated a Tppp3-deficient mouse ( Tppp3 ∆ex2-4/∆ex2-4 ; Tppp3 knockout (KO)) and found that the Tppp3 KO mouse exhibited cough and hyposmia phenotype. The loss of Tppp3 disrupted the apical microtubules (MTs) meshwork in the tracheal MCCs, leading to random orientation and alignment of basal bodies (BBs) of the motile cilia. Unexpectedly, aberrant ciliary membrane fusions occurred in the trachea of the Tppp3 KO mice. We examined the underlying molecular mechanism of the ciliary membrane fusion by isolating the tracheal cilium. Liquid Chromatography-Mass Spectrometry (LC–MS) analysis as well as pharmacological analysis revealed that hyperaccumulation of a long chain ceramide at the ciliary membrane caused the membrane fusion. In addition, sensory cilia formation was impaired in the olfactory sensory neuron of the Tppp3 KO mice. Due to the lack of Tppp3, dendritic MT assembly that underlies long-range migration of BBs toward the cell surface was impaired. These findings demonstrate that Tppp3, as well as the defined intracellular MT architecture, regulate proper orientation/subcellular positioning of BBs and the independency of individual motile cilium membranes.

Correlation between clay activity and dynamic properties of intact loess: evidence from microstructure and water-retention capacity

Bearing characteristics and settlement calculation method of pile groups in beaded karst areas

In order to explore the influence of the different position of karst on the bearing capacity of pile group foundation, a theoretical analysis was carried out from the perspective of the reduction rate of pile group effect. Combined with the calculation method of pile foundation settlement, the calculation formula for pile group foundation settlement corresponding to different relative position conditions of karst caves was derived. Finite element numerical simulations were conducted using data from real pile foundation projects, and the results were verified with field measurements. The results demonstrate that the proposed method for analyzing pile bearing characteristics is widely applicable. When the karst cave is located beneath the central area of the pile foundation, the ultimate bearing capacity is relatively high. However, when the karst cave is located in the peripheral area, the ultimate bearing capacity decreases. The conclusions provide a theoretical basis and practical guidance for managing and controlling similar engineering problems.

Harnessing non-equilibrium forces to optimize work extraction

Abstract While optimal control theory offers effective strategies for minimizing energetic costs in noisy microscopic systems over finite durations, a significant opportunity lies in exploiting the temporal structure of non-equilibrium forces. We demonstrate this by presenting exact analytical forms for the optimal protocol and the corresponding work for any driving force and protocol duration. We also derive a general quasistatic bound on the work, relying only on the coarse-grained, time-integrated characteristics of the applied forces. Notably, we show that the optimal protocols automatically harness information about non-equilibrium forces and an initial state measurement to extract work. These findings chart new directions for designing adaptive, energy-efficient strategies in noisy, time-dependent environments, as illustrated through our examples of periodic driving forces and active matter systems. By exploiting the temporal structure of non-equilibrium forces, this largely unexplored approach holds promise for substantial performance gains in microscopic devices operating at the nano- and microscale.

Forests weather soil cations and lose them to streams