Mechanistic Features Research Articles

Truthful and privacy-preserving generalized linear models

This paper explores estimating Generalized Linear Models (GLMs) when agents are strategic and privacy-conscious. We aim to design mechanisms that encourage truthful reporting, protect privacy, and ensure outputs are close to the true parameters. Initially, we address models with sub-Gaussian covariates and heavy-tailed responses with finite fourth moments, proposing a novel private, closed-form estimator. Our mechanism features: (1) o(1)-joint differential privacy with high probability; (2) o(1n)-approximate Bayes Nash equilibrium for (1−o(1))-fraction of agents; (3) o(1) error in parameter estimation; (4) individual rationality for (1−o(1)) of agents; (5) o(1) payment budget. We then extend our approach to linear regression with heavy-tailed data, using an ℓ4-norm shrinkage operator to propose a similar estimator and payment scheme.

Animal-Morphing Bio-Inspired Mechatronic Systems: Research Framework in Robot Design to Enhance Interplanetary Exploration on the Moon

Over the past 50 years, the space race has potentially grown due to the development of sophisticated mechatronic systems. One of the most important is the bio-inspired mobile-planetary robots, actually for which there is no reported one that currently works physically on the Moon. Nonetheless, significant progress has been made to design biomimetic systems based on animal morphology adapted to sand (granular material) to test them in analog planetary environments, such as regolith simulants. Biomimetics and bio-inspired attributes contribute significantly to advancements across various industries by incorporating features from biological organisms, including autonomy, intelligence, adaptability, energy efficiency, self-repair, robustness, lightweight construction, and digging capabilities-all crucial for space systems. This study includes a scoping review, as of July 2024, focused on the design of animal-inspired robotic hardware for planetary exploration, supported by a bibliometric analysis of 482 papers indexed in Scopus. It also involves the classification and comparison of limbed and limbless animal-inspired robotic systems adapted for movement in soil and sand (locomotion methods such as grabbing-pushing, wriggling, undulating, and rolling) where the most published robots are inspired by worms, moles, snakes, lizards, crabs, and spiders. As a result of this research, this work presents a pioneering methodology for designing bio-inspired robots, justifying the application of biological morphologies for subsurface or surface lunar exploration. By highlighting the technical features of actuators, sensors, and mechanisms, this approach demonstrates the potential for advancing space robotics, by designing biomechatronic systems that mimic animal characteristics.

Funding Mechanisms for State Road Maintenance

The deferred maintenance practices for road infrastructure will result in increasing life-cycle costs and deteriorating economic productivity. Governments have addressed the issue by expanding revenue sources, but we don’t know much about the revenue allocation mechanisms. This research reviewed 50 states’ constitutions and statutes to find the similarities and differences in the institutional features of the funding mechanisms for road maintenance. As of 2020, it found that ten states had strict earmarking mechanisms for securing resources for road maintenance; four states had less strict earmarking mechanisms. Furthermore, this research found wide variations in the designs of 50 states’ transportation/highway trust funds and their uses. The research developed the eight propositions to examine the relationship between the funding mechanisms and state highway maintenance spending. Overall, this research contributes to the current literature and policymakers to enhance our understanding of the funding mechanisms of 50 states for road maintenance.

Conformational plasticity links structural instability of NAA10F128I and NAA10F128L mutants to their catalytic deregulation

The acetylation of proteins' N-terminal amino groups by the N-acetyltransferase complexes plays a crucial role in modulating the spatial stability and functional activities of diverse human proteins. Mutations disrupting the stability and function of NAA10 result in X-linked rare genetic disorders. In this study, we conducted a global analysis of the impact of fifteen disease-associated missense mutations in NAA10. The analyses revealed that mutations in specific residues, such as Y43, V107, V111, and F128, predictably disrupted interactions essential for NAA10 stability, while most mutations (except R79C, A111W, Q129P, and N178K) expectedly led to structural destabilization. Mutations in many conserved residues within short linear motifs and post-translational modification sites were predicted to affect NAA10 functionality and regulation. All mutations were classified as pathogenic, with F128I and F128L identified as the most destabilizing mutations. The findings show that the F128L and F128I mutations employ different mechanisms for the loss of catalytic activities of NAA10F128L and NAA10F128I due to their structural instability. These two mutations induce distinct folding energy states that differentially modulate the structures of different regions of NAA10F128L and NAA10F128I. Specifically, the predicted instability caused by the F128I mutation results in decreased flexibility within the substrate-binding region, impairing the substrate peptide binding ability of NAA10F128I. Conversely, F128L is predicted to reduce the flexibility of the region containing the acetyl-CoA binding residues in NAA10F128L. Our study provides insights into the mechanism of catalytic inactivation of mutants of NAA10, particularly elucidating the mechanistic features of the structural and functional pathogenicity of the F128L and F128I mutations.

Lung cancer and pulmonary tuberculosis: key features of molecular mechanisms of concomitant disease

Lung cancer and pulmonary tuberculosis have long been significant problems for global health, occupying leading positions in terms of morbidity and mortality in both developed and developing countries. Numerous clinical and experimental studies have allowed to get knowledge of the mechanisms of development of these pathological processes individually, the impact of diseases on the macroorganism, and various options of treatment. According to population studies, the interaction between these two processes is undeniable – both active tuberculosis and post-tuberculosis changes are equally risk factors for the development of neoplastic processes, and malignant tumors create favorable conditions and predispositions for the development of mycobacterial infection. However, the mechanisms of interaction between these two diseases in concomitant cases remain opened and insufficiently studied. This literature review provides a detailed description of the variants of lung cancer and pulmonary tuberculosis combinations, the pathophysiological basis of the interaction between infectious and neoplastic processes: modulation of the immune response by M. tuberculosis and lung tumor; oncogenic signaling pathways activated by tuberculosis infection; mechanisms of epithelial-mesenchymal transition in post-tuberculosis scar changes and its role in the formation of so-called "scarcinoma"; the relationship between tumor-mediated and tuberculosis-associated immunosuppression; the role of the PD-1: PD-L signaling pathway, and the influence of modern types of anti-tumor immunotherapy on the course of these pathological processes. The final part of the review presents our own data from experimental studies on the combination of cancer and tuberculosis in a laboratory model, identifying promising directions for further research on this issue.

The SRG/eROSITA All-Sky Survey

Context. Galaxy groups lying between galaxies and galaxy clusters in the mass spectrum of dark matter halos play a crucial role in the evolution and formation of the large-scale structure. Their shallower potential wells compared to clusters of galaxies make them excellent sources to constrain non-gravitational processes such as feedback from the central active galactic nuclei (AGN). Aims. We investigate the impact of feedback, particularly from AGN, on the entropy and characteristic temperature measurements of galaxy groups detected in the SRG/eROSITA’s first All-Sky Survey (eRASS1) to shed light on the characteristics of the feedback mechanisms and help guide future AGN feedback implementations in numerical simulations. Methods. We analyzed the deeper eROSITA observations of 1178 galaxy groups detected in the eRASS1. We divided the sample into 271 subsamples based on their physical and statistical properties and extracted average thermodynamic properties, including the electron number density, temperature, and entropy, at three characteristic radii from cores to outskirts along with the integrated temperature by jointly analyzing X-ray images and spectra following a Bayesian approach. Results. We present the tightest constraints with unprecedented statistical precision on the impact of AGN feedback through our average entropy and characteristic temperature measurements of the largest group sample used in X-ray studies, incorporating major systematics in our analysis. We find that entropy shows an increasing trend with temperature in the form of a power-law-like relation at the higher intra-group medium (IGrM) temperatures, while for the low-mass groups with cooler (T < 1.44 keV) IGrM temperatures, a slight flattening is observed on the average entropy. Overall, the observed entropy measurements agree well with the earlier measurements in the literature. Additionally, comparisons with the state-of-the-art cosmological hydrodynamic simulations (MillenniumTNG, Magneticum, OWL) after applying the selection function calibrated for our galaxy groups reveal that observed entropy profiles in the cores are below the predictions of simulations. At the mid-region, the entropy measurements agree well with the Magneticum simulations, whereas the predictions of MillenniumTNG and OWL simulations fall below observations. At the outskirts, the overall agreement between the observations and simulations improves, with Magneticum simulations reproducing the observations the best. Conclusions. These measurements will pave the way for achieving more realistic AGN feedback implementations in numerical simulations. The future eROSITA Surveys will enable the extension of the entropy measurements in even cooler IGrM temperatures below 0. 5 keV, allowing for the testing of the AGN feedback models in this regime.

ВОЗМОЖНОСТИ СОВРЕМЕННЫХ НЕИНВАЗИВНЫХ МЕТОДИК ИЗМЕРЕНИЯ ВНУТРИБРЮШНОГО ДАВЛЕНИЯ ПРИ АБДОМИНАЛЬНОМ КОМПАРТМЕНТ-СИНДРОМЕ У ПАЦИЕНТОВ В КРИТИЧЕСКОМ СОСТОЯНИИ

Intra-abdominal pressure (IAP) is rarely measured by default in intensive care patients. Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) contribute significantly to the development of multiorgan insufficiency in critically ill patients and are associated with significant morbidity and mortality. This article discusses and analyzes the causes and features of the pathophysiological mechanisms of increased intra-abdominal pressure, as well as modern aspects of the diagnosis and treatment of patients with abdominal compartment syndrome.

Molecular mechanism of androgen receptor mutation in multigenerational mild androgen insensitivity syndrome.

Androgen insensitivity syndrome (AIS) due to androgen receptor (AR) mutations create a spectrum of clinical presentations based on residual AR function with the mildest impairment creating mild AIS (MAIS) whose undefined molecular mechanism and subtle clinical features leave it little understood and underdiagnosed. in silico modelling and in vitro androgen bioassay of the mutated AR to identify its structural and physiological mechanism. Describing clinical features and responses to high dose testosterone treatment of three cases of MAIS cases across a six-generation family pedigree. Structural and dynamic in silico molecular modelling and in vitro yeast-based androgen bioassays of the mutant AR. Three cases of MAIS with consistent (gynecomastia, micropenis) and variable (infertility) clinical features across generations and effects of high dose testosterone treatment. The missense AR exon 8 mutation (nucleotide aga > gga, p.R872G arginine to glycine), known to cause increases ligand dissociation rate from mutant AR in binding assays, modelling shows the mutation weakens the closure energy of the "lid" of the ligand binding pocket allowing for easier ligand dissociation from binding site but with unimpaired in vitro androgen bioactivity. High dose testosterone treatment for 3 years in one young man caused increased virilisation and height growth but was ineffective for micropenis. Genetic counselling allowed effective prediction of MAIS risks in progeny for a carrier and non-carrier sisters. The differential diagnosis and clinical management of MAIS is reviewed. The novel molecular mechanism of an AR ligand binding domain mutation in MAIS may be present in other case of MAIS.

DiamondNet: A Neural-Network-Based Heterogeneous Sensor Attentive Fusion for Human Activity Recognition.

With the proliferation of intelligent sensors integrated into mobile devices, fine-grained human activity recognition (HAR) based on lightweight sensors has emerged as a useful tool for personalized applications. Although shallow and deep learning algorithms have been proposed for HAR problems in the past decades, these methods have limited capability to exploit semantic features from multiple sensor types. To address this limitation, we propose a novel HAR framework, DiamondNet, which can create heterogeneous multisensor modalities, denoise, extract, and fuse features from a fresh perspective. In DiamondNet, we leverage multiple 1-D convolutional denoising autoencoders (1-D-CDAEs) to extract robust encoder features. We further introduce an attention-based graph convolutional network to construct new heterogeneous multisensor modalities, which adaptively exploit the potential relationship between different sensors. Moreover, the proposed attentive fusion subnet, which jointly employs a global-attention mechanism and shallow features, effectively calibrates different-level features of multiple sensor modalities. This approach amplifies informative features and provides a comprehensive and robust perception for HAR. The efficacy of the DiamondNet framework is validated on three public datasets. The experimental results demonstrate that our proposed DiamondNet outperforms other state-of-the-art baselines, achieving remarkable and consistent accuracy improvements. Overall, our work introduces a new perspective on HAR, leveraging the power of multiple sensor modalities and attention mechanisms to significantly improve the performance.

A supramolecular approach towards the photorelease of encapsulated caged acids in water: 7-diethylaminothio-4-coumarinyl molecules as triggers.

Herein, we establish the release of aliphatic acids in water upon excitation of 7-diethylaminothio-4-coumarinyl derivatives encapsulated within the organic host octa acid (OA). The 7-diethylaminothio-4-coumarinyl skeleton, employed here as the trigger, photoreleases caged molecules from the excited triplet state, in contrast to its carbonyl analogue, where the same reaction is known to occur from the excited singlet state. Encapsulation in OA solubilizes molecules in water that are otherwise water-insoluble, and retains the used trigger within itself following the release of the aliphatic acid. Such supramolecular characteristics usher in new features to the photorelease methodology. The thiocarbonyl chromophore extends the absorption of coumarinyl trigger to visible range while enhancing the intersystem crossing (ISC) to the triplet state, making it the reactive state. Despite the non-polar environment within the OA capsules the photocleavage occurs in a heterolytic fashion to release the conjugate base and the used trigger as triplet carbocation in an adiabatic process. Interestingly, the triplet carbocation crosses to the ground singlet surface (closed shell singlet carbocation) with the help of water molecules, possibly aided by C = S chromophore. Utilizing the known excited state dynamics of related thiocoumarinyl and coumarinyl systems, we have identified a few of the important mechanistic features of the photorelease process of 7-diethylaminothio-4-coumarinyl derivatives. Ultrafast excited state dynamic studies and quantum chemical calculations planned should help us better understand the photorelease process so as to effectively exploit the proposed system for potential applications.

C-H Activation and Hydrogen Isotope Exchange of Aryl Carbamates using Iridium(I) Complexes Bearing Chelating NHC-Phosphine Ligands.

Hydrogen isotope exchange (HIE) via C-H activation constitutes an efficient method for the synthesis of isotopically-enriched compounds, which are crucial components of the drug discovery process and are extensively employed in mechanistic studies. A series of iridium(I) complexes, bearing a chelating phosphine-N-heterocyclic carbene ligand, was designed and synthesized for application in the catalytic HIE of challenging N- and O-aryl carbamates. A broad range of substrates were labeled efficiently, and applicability to biologically-relevant systems was demonstrated by labeling an ʟ-tyrosine-derived carbamate with excellent levels of deuterium incorporation. Combined theoretical and experimental studies unveiled intriguing mechanistic features within this process, in comparison to C-H activation and hydrogen isotope exchange catalysed by monodentate Ir(I) NHC/phosphine complexes.

What Can CISS Teach Us about Electron Transfer?

Electron transfer (eT) processes have garnered the attention of chemists and physicists for more than seven decades, and it is commonly believed that the essential features of the electron transfer mechanism are well understood─despite some open questions relating to the efficiency of long-range eT in some systems and temperature effects that are difficult to reconcile with the existing theories. The chiral induced spin selectivity (CISS) effect, which has been studied experimentally since 1999, demonstrates that eT through chiral systems depends on the electron's spin. Attempts to explain the CISS effect by adding spin-orbit coupling to the existing eT theories fails to reproduce the experimental results quantitatively, and it has become evident that the theory for explaining CISS must consider electron-vibration and/or electron-electron interactions. In this Perspective we identify some features of the CISS effect that imply that we should reconsider and refine the Marcus-Levich-Jortner mechanistic description for eT processes, especially for nonlinear systems and in the case of long-range eT.

High-Rate Nitrite Production by Stable Denitrification Granular Sludge in a Reinforced-Mixing Up-Flow System: Shift in Spatiotemporal Characteristics of Functional Bacteria and Metagenomic Mechanisms

High-Rate Nitrite Production by Stable Denitrification Granular Sludge in a Reinforced-Mixing Up-Flow System: Shift in Spatiotemporal Characteristics of Functional Bacteria and Metagenomic Mechanisms

Effect of Short-Term Restraint Stress on the Expression of Genes Associated with the Response to Oxidative Stress in the Hypothalamus of Hypertensive ISIAH and Normotensive WAG Rats

Normotensive and hypertensive organisms respond differently to stress factors; however, the features of the central molecular genetic mechanisms underlying the reaction of the hypertensive organism to stress have not been fully established. In this study, we examined the transcriptome profiles of the hypothalamus of hypertensive ISIAH rats, modeling a stress-sensitive form of arterial hypertension, and normotensive WAG rats at rest and after exposure to a single short-term restraint stress. It was shown that oxidative phosphorylation is the most significantly enriched process among metabolic changes in the hypothalamus of rats of both strains when exposed to a single short-term restraint stress. The analysis revealed DEGs representing both a common response to oxidative stress for both rat strains and a strain-specific response to oxidative stress for hypertensive ISIAH rats. Among the genes of the common response to oxidative stress, the most significant changes in the transcription level were observed in Nos1, Ppargc1a, Abcc1, Srxn1, Cryab, Hspb1, and Fosl1, among which Abcc1 and Nos1 are associated with hypertension, and Fosl1 and Ppargc1a encode transcription factors. The response to oxidative stress specific to hypertensive rats is associated with the activation of the Fos gene. The DEG’s promoter region enrichment analysis allowed us to hypothesize that the response to oxidative stress may be mediated by the participation of the transcription factor CREB1 (Cyclic AMP-responsive element-binding protein 1) and the glucocorticoid receptor (NR3C1) under restraint stress in the hypothalamus of both rat strains. The results of the study revealed common and strain-specific features in the molecular mechanisms associated with oxidative phosphorylation and oxidative stress response in the hypothalamus of hypertensive ISIAH and normotensive WAG rats following a single short-term restraint stress. The obtained results expand the understanding of the most significant molecular targets for further research aimed at developing new therapeutic strategies for the prevention of the consequences of acute emotional stress, taking into account the hypertensive state of the patient.

Estimation Network for Multiple Chemical Parameters of Astragalus Leaves Based on Attention Mechanism and Multivariate Hyperspectral Features

In the context of smart agriculture, accurately estimating plant leaf chemical parameters is crucial for optimizing crop management and improving agricultural yield. Hyperspectral imaging, with its ability to capture detailed spectral information across various wavelengths, has emerged as a powerful tool in this regard. However, the complex and high-dimensional nature of hyperspectral data poses significant challenges in extracting meaningful features for precise estimation. To address this challenge, this study proposes an end-to-end estimation network for multiple chemical parameters of Astragalus leaves based on attention mechanism (AM) and multivariate hyperspectral features (AM-MHENet). We leverage HybridSN and multilayer perceptron (MLP) to extract prominent features from the hyperspectral data of Astragalus membranaceus var. mongholicus (AMM) leaves and stems, as well as the surface and deep soil surrounding AMM roots. This methodology allows us to capture the most significant characteristics present in these hyperspectral data with high precision. The AM is subsequently used to assign weights and integrate the hyperspectral features extracted from different parts of the AMM. The MLP is then employed to simultaneously estimate the chlorophyll content (CC) and nitrogen content (NC) of AMM leaves. Compared with estimation networks that utilize only hyperspectral data from AMM leaves as input, our proposed end-to-end AM-MHENet demonstrates superior estimation performance. Specifically, AM-MHENet achieves an R2 of 0.983, an RMSE of 0.73, an MAE of 0.49, and an RPD of 7.63 for the estimation of CC in AMM leaves. For NC estimation, AM-MHENet achieves an R2 value of 0.977, an RMSE of 0.27, an MAE of 0.16, and an RPD of 6.62. These results underscore AM-MHENet’s effectiveness in significantly enhancing the accuracy of both CC and NC estimation in AMM leaves. Moreover, these findings indirectly suggest a strong correlation between the development of AMM leaves and stems, as well as the surface and deep soil surrounding the roots of AMM, and directly highlight the ability of AM to effectively focus on the relevant spectral features within the hyperspectral data. The findings from this study could offer valuable insights into the simultaneous estimation of multiple chemical parameters in plants, thereby making a contribution to the existing body of research in this field.

Thickened Flame Model Extension for Dual Gas Turbine Combustion: Validation Against Single Cup Atmospheric Test

Abstract The development of predictive combustion models is more and more strategic in the design definition of gas turbine (GT) combustor. The thickened flame model (TFM), despite its high computational cost, is one of the most accurate approach available in literature since it can naturally take into account the nonequilibrium effects into the flame brush (i.e., strain and heat losses) as well as preferential diffusion when hydrogen is employed. Conversely, the original formulation of this combustion model needs several adjustments to accommodate the properties of the mixture when different streams of fuels and/or oxidizers are present in the system. The present work represents a first step in the extension of this combustion model to handle multiple streams of fuels and oxidizers. More specifically, an industrial burner fed with two different fuel streams and air as oxidizer is considered. The pilot fuel line is fed with microhydrogen injections with the aim to enhance the lean blow-out margin, while the main one is with pure methane. Dedicated tests are performed at the Technology for High Temperature laboratory (University of Florence) to retrieve the main information characterizing the burner (emissions, temperature, and pressure pulsations) as well as OH* chemiluminescence for the flame shape and position at the same operating conditions. The comparison between the numerical results and the experimental data will provide highlights about the ability of the extended-TFM to capture the main features of the flame stabilization mechanisms.

Interpreting the power spectral density of a fluctuating colloidal current.

The transport of molecules through biological and synthetic nanopores is governed by multiple stochastic processes that lead to noisy, fluctuating currents. Disentangling the characteristics of different noise-generating mechanisms is central to better understanding molecular transport at a fundamental level but is extremely challenging in molecular systems due to their complexity and relative experimental inaccessibility. Here, we construct a colloidal model microfluidic system for the experimental measurement of particle currents, where the governing physical properties are directly controllable and particle dynamics directly observable, unlike in the molecular case. Currents of hard spheres fluctuate due to the random arrival times of particles into the channel and the distribution of particle speeds within the channel, which results in characteristic scalings in the power spectral density. We rationalize these scalings by quantitatively comparing to a model for shot noise with a finite transit time, extended to include the distribution of particle speeds. Particle velocity distributions sensitively reflect the confining geometry, and we interpret and model these in terms of the underlying fluid flow profiles. Finally, we explore the extent to which details of these distributions govern the form of the resulting power spectral density, thereby establishing concrete links between the power spectral density and underlying mechanisms for this experimental system. This paves the way for establishing a more systematic understanding of the links between characteristics of transport fluctuations and underlying molecular mechanisms in driven systems such as nanopores.

Research on magnetic nonchain transport of steel cartridge casing ammunition

Magnetic force is used to drive ferromagnetic objects by shortening the magnetic flux path to reduce magnetic reluctance and increase magnetic conductivity. Based on this characteristic, magnetic force drives have been widely applied in various fields, such as military, transportation, and engineering, attracting significant attention. This paper proposes a method for the nonchain transport of steel shell ammunition based on magnetic force. The force generated by the minimal magnetic resistance in the air gap is utilized to drive the steel shell ammunition. A calculation model for the driving component is proposed using the Maxwell stress tensor method, and the accuracy of the model is verified by simulating ammunition motion curves using finite element software. Finally, prototype experiments are conducted to explore the motion conditions under uncertain ammunition masses. The magnetic nonchain ammunition transport mechanism features a simpler structure and lower maintenance costs, making it more suitable for use on unmanned platforms.

Enhanced Phishing Website Detection Using Dual-Layer CNN and GRU with Attention Mechanism and Lexical NLP Features

Enhanced Phishing Website Detection Using Dual-Layer CNN and GRU with Attention Mechanism and Lexical NLP Features

An in-depth exploration of ethnomedicinal applications, phytochemical profiles, and pharmacological potentials: unveiling Withania somnifera

Researchers have extensively studied Withania somnifera (L.) Dunal, a woody shrub renowned for its multifaceted medicinal attributes such as antibacterial, anti-inflammatory, adaptogenic, aphrodisiac, and tonifying properties, because of its medicinal and traditional values. However, comprehensive information about its medicinal uses and pharmacological implications is scattered across various sources. Thus, this study aims to provide a comprehensive review of its ethnomedicinal uses, phytochemistry, and pharmacological attributes, consolidating information from diverse data sources. Systematic investigations have revealed the presence of diverse phytochemicals in W. somnifera, including major alkaloids, withanolides, flavonoids, tannins, oils, phytosterols, and amino acids. Extracts, fractions, and bioactive compounds derived from W. somnifera exhibited potent antibacterial, anti-inflammatory, anti-aging, anti-analgesic, anti-cancer, antivenom, anti-fungal, and anti-viral activities. W. somnifera serves as a valuable source of phytochemicals with diverse biological activities, offering significant therapeutic benefits globally. However, further studies are needed to assess potential side effects. Additionally, while several isolated compounds have demonstrated notable bioactivities, future research should focus on elucidating their mechanistic features to facilitate their integration into drug discovery endeavors.