Transport Components Research Articles

Tube deformation measurement with camera and laser

Underwater tubes are critical infrastructure components for city transportation. The installation and connection of immersed tubes in underwater environments require accurate localization technologies. Currently, many immersed tube localization methods rely on Global Navigation Satellite System (GNSS) based satellite towers. However, various forces such as the tube’s own weight, water pressure, etc. inevitably cause tube deformations and satellite tower to tilt, then affecting tube posture estimation. Targeting this challenge, this paper develops a novel underwater immersed tube deformation measurement algorithm, which detects tube geometric deformation based on cameras and lasers. The cameras and lasers are used to measure horizontal and vertical deformations respectively. Then, the overall geometric deformation can be obtained from the two deformations accurately. Extensive real-world experiments demonstrate that, compared to the GNSS-based satellite towers method, our proposed method significantly reduces localization errors and has been applied to the construction program of the Shenzhen-Zhongshan underwater tube tunnel.

Introducing a novel TRAPPC10 gene variant as a potential cause of developmental delay and intellectual disability in an Iranian family.

TRAPP complexes are crucial components for intracellular transport and cellular organization. Their role in vesicle trafficking, particularly through their involvement in the secretory pathway, make them more important in neurodevelopmental mechanisms. This study aims to identify a novel genetic variant, associated with developmental delay and intellectual disability by analyzing a consanguineous Iranian family. Here, we performed whole-exome sequencing on an Iranian family, originating from a small population. The patient presented with severe developmental delay, microcephaly, and behavioral abnormalities. Through our analysis, we discovered a new biallelic variant on a previously introduced gene: TRAPPC10 (NM_003274.5): c.3222C > A; p.(Cys1074Ter) that is a potential cause for these specific clinical characteristics. Previous functional analysis suggest that the mutation causes premature termination of protein translation, likely leading to nonsense-mediated decay because of biallelic loss of functional TRAPPC10 protein which leads to severe developmental delay, microcephaly, and behavioral abnormalities such as aggression and autistic traits. The aim of this research is to discover a novel variant in the TRAPPC10 gene that is responsible for a particular neurodevelopmental condition, dominantly characterized by developmental delay, intellectual disability, and microcephaly. These findings advance the comprehension of TRAPP-related diseases and emphasize the need for further exploration into the impact of TRAPPC10 on the development of the nervous system.

On the function of TRAP substrate-binding proteins: the isethionate-specific binding protein IseP.

Bacteria evolve mechanisms to compete for limited resources and survive in new niches. Here we study the mechanism of isethionate import from the sulfate-reducing bacterium Oleidesulfovibrio alaskensis. The catabolism of isethionate by Desulfovibrio species has been implicated in human disease, due to hydrogen sulfide production, and has potential for industrial applications. O.alaskensis employs a tripartite ATP-independent periplasmic (TRAP) transporter (OaIsePQM) to import isethionate, which relies on the substrate-binding protein (OaIseP) to scavenge isethionate and deliver it to the membrane transporter component (OaIseQM) for import into the cell. We determined the binding affinity of isethionate to OaIseP by isothermal titration calorimetry (ITC), KD = 0.95 µM (68% CI = 0.6-1.4 µM), which is weaker compared to other TRAP substrate-binding proteins. The X-ray crystal structures of OaIseP in the ligand-free and isethionate-bound forms were obtained and showed that in the presence of isethionate, OaIseP adopts a closed conformation whereby two domains of the protein fold over the substrate. We serendipitously discovered two crystal forms with sulfonate-containing buffers (HEPES and MES) bound in the isethionate-binding site. However, these do not evoke domain closure, presumably because of the larger ligand size. Together, our data elucidate the molecular details of how a TRAP substrate-binding protein binds a sulfonate-containing substrate, rather than a typical carboxylate-containing substrate. These results may inform future antibiotic development to target TRAP transporters and provide insights into protein engineering of TRAP transporter substrate-binding proteins.

Physiological Effects of TolC-Dependent Multidrug Efflux Pumps in Escherichia coli: Impact on Motility and Growth Under Stress Conditions.

Enterobacteriaceae possess eight TolC-dependent multidrug efflux pumps: AcrAB-TolC, AcrAD-TolC, AcrEF-TolC, MdtEF-TolC, MdtABC-TolC, EmrAB-TolC, EmrYK-TolC, and MacAB-TolC, which efflux bile salts, antibiotics, metabolites, or other compounds. However, our understanding of their physiological roles remains limited, especially for less-studied pumps like EmrYK-TolC. In this study, we tested the effects on swimming motility and growth under stress conditions of Escherichia coli mutants individually deleted for each inner-membrane transporter component of all eight TolC-dependent pumps, a mutant deleted for the AcrB-accessory protein AcrZ, and a mutant simultaneously deleted for all eight pumps (ΔtolC). We found that all mutants tested, except the ΔemrY and ΔacrZ mutants, displayed increased swimming motility. Additionally, the loss of each individual TolC-dependent pump or AcrZ did not reduce growth and sometimes even enhanced it compared to the parental strain under various growth conditions: temperature (LB at 25, 30, 37, and 42°C), pH (LB at pH 6.0, 7.4, and 9.0; and LB buffered to pH 6.0, 7.4, and 8.25), LB with limited air exchange, and nutritional stress (M9-glucose or M9-glycerol). In contrast, the ΔtolC mutant grew significantly slower than the parental strain under all conditions tested except in LB-TRIS pH 7.4 and LB with limited air exchange. Overall, these findings indicate that while individual TolC-dependent pumps are generally dispensable for growth under many stress conditions in the absence of antimicrobials, possibly due to their partially overlapping substrate profiles, TolC-dependent efflux is required for maximal growth under most conditions.

Caregiver Accompaniment in Pediatric Critical Care Transport: A Systematic Scoping Review.

Family-centered care is a critical component of critical care interfacility and medical retrieval transport (MRT) services. These services provide a critical bridge for a physiologically and psychologically unique population often best served in specialized, tertiary centers. Caregivers often wish to accompany patients during MRT. However, there is currently little research on the impact of caregiver accompaniment on MRT. The aim of the study is to determine: 1) What are caregiver attitudes to accompanied and unaccompanied MRT? 2) What are healthcare provider attitudes to caregiver presence? 3) What are patient attitudes to caregiver presence? and 4) Are there differences in patient outcome depending on caregiver presence? Data sources are MEDLINE, Embase, and CINAHL. Studies with a focus on patient, caregiver, or family-oriented care practices in MRT. Reviewed articles were not restricted unless they discussed neonatal transport, palliative transport, were non-English, or were conference proceedings. We screened 1373 articles, with 45 full-text articles reviewed. After removal of duplicates and abstract-only results, 25 articles remained. Three additional articles were found in references of reviewed articles. Articles generally supported caregiver presence on MRT, with caregivers and providers in agreement. However, for many services, space was a limiting factor controlling when caregivers could travel. There is a paucity of literature on this topic, and studies were entirely from English-speaking countries. Caregivers and healthcare providers largely prefer caregiver accompaniment on MRT services. There is little data on patient perspectives and transport-related adverse events affecting patient outcomes.

Quantification of Salt Transports Due To Exchange Flow and Tidal Flow in Estuaries

AbstractTo understand mechanisms of salt intrusion in estuaries, we develop a semi‐analytical model, that explicitly accounts for salt transport by both exchange flow and tidal flow. This model, after calibration, successfully hindcasts hydrodynamics and salinity dynamics in three estuaries that have strongly different characteristics. We find, from analyzing the model results for these three estuaries, that salt transport processes by exchange flow and tidal flow interact through the subtidal stratification. Transport by exchange flow creates stratification, thereby generating a phase shift of tidal salinity with respect to the tidal flow, which is important for the magnitude of the tidal salt transport. Conversely, the strength of tidal currents determines the vertical mixing that breaks down stratification. A new analytical formulation is presented for the component of the salt transport driven by the depth‐averaged tidal flow. This salt transport is larger than the component associated with the vertical shear of the tidal current. Finally, a method that yields analytical equations that quantify the importance of different contributions to the salt transport using only primary information is developed using approximate solutions for the subtidal stratification. This method performs well for the estuaries considered.

Enhancing Tram Safety in Mixed-Traffic Systems: A Case Study of Melbournes Tram Collision Factors and Improvement Strategies

Abstract: Trams, a vital component of public transportation, operate within diverse environments ranging from fully segregated tracks to mixed-traffic systems. This study investigated tram collisions in Melbournea city renowned for its extensive and historic tram networkand explored both systemic and behavioral factors contributing to these incidents. The analysis identified key factors such as the arrangement of tram platforms, intersection design, right-of-way (ROW) regulations, tram driver behavior, and the actions of other road users. The study revealed that inadequate tram platform arrangements and suboptimal intersection designs are major contributors to tram collisions. Recommendations for improvement include implementing elevated, standalone tram platforms with protective barriers and accessible ramps, expanding the use of Hook Turn intersections, and integrating intelligent transportation systems to enhance traffic management. Additionally, addressing behavioral factors is crucial. Enhanced training for tram drivers and educational campaigns for pedestrians and other road users are proposed to improve situational awareness and adherence to safety norms. By addressing both objective systemic issues and subjective behavioral factors, this study aimed to enhance the safety of tram operations in mixed-traffic environments, ultimately reducing collision risks and improving public confidence in tram systems.

A Distributed VMD-BiLSTM Model for Taxi Demand Forecasting with GPS Sensor Data.

With the ubiquitous deployment of mobile and sensor technologies in modes of transportation, taxis have become a significant component of public transportation. However, vacant taxis represent an important waste of transportation resources. Forecasting taxi demand within a short time achieves a supply-demand balance and reduces oil emissions. Although earlier studies have forwarded highly developed machine learning- and deep learning-based models to forecast taxicab demands, these models often face significant computational expenses and cannot effectively utilize large-scale trajectory sensor data. To address these challenges, in this paper, we propose a hybrid deep learning-based model for taxi demand prediction. In particular, the Variational Mode Decomposition (VMD) algorithm is integrated along with a Bidirectional Long Short-Term Memory (BiLSTM) model to perform the prediction process. The VMD algorithm is applied to decompose time series-aware traffic features into multiple sub-modes of different frequencies. After that, the BiLSTM method is utilized to predict time series data fed with the relevant demand features. To overcome the limitation of high computational expenses, the designed model is performed on the Spark distributed platform. The performance of the proposed model is tested using a real-world dataset, and it surpasses existing state-of-the-art predictive models in terms of accuracy, efficiency, and distributed performance. These findings provide insights for enhancing the efficiency of passenger search and increasing the profit of taxicabs.

State special transport service in the system of subjects of the Ministry of Defense of Ukraine: directions of influence and the role of public administration for their implementation

It was emphasized that in the conditions of ongoing Russian aggression, the issue of effective and stable functioning of the system of the Ministry of Defense of Ukraine has become important. It is noted that such an intention is possible only thanks to the systematically effective work of all subjects of this system. The exceptional role of the State Special Service of Transport in this aspect is emphasized, given the subject orientation of the latter. We are talking about the transport component, which is one of the basic prerequisites for the successful implementation of the lion’s share of measures by subjects not only of the ministry system, but also of the entire security and defense sector. The position of the State Special Service of Transport as a subject of public-legal relations at the current stage of law-making is highlighted in general outlines. It was found that it is appropriate to talk about an institution endowed with the status of a specialized military formation, which carries out a number of defense measures peculiar only to it. Despite its regulatory specifics, it is advisable to talk about a number of similar parameters, compared to the rest of the institutions. The essence of the directions of the analyzed body’s work, including under the current situation, is outlined and disclosed. Arguably, it is emphasized that such directions are derived from the functions of the institution, which the latter’s officials implement in practice. The legislator’s position on their gradation into two fundamental groups was supported and developed: 1) peacetime; 2) a special period. Based on this, the author’s vision of the quantitative and specific composition of the areas of work of the State Special Service of Transport is proposed, followed by their general characteristics. The problems of the importance of public administration tools in the framework of the implementation of management functions performed by this specialized military formation have been studied. It is emphasized that the presence of these tools is a prerequisite for the implementation of management steps. The above constitutes a critical and unalternative position from the point of view of the application of appropriate measures within the limits of one or another outlined direction. Based on the preliminary results, an attempt was made to determine the place of the State Special Transport Service in the structure of the Ministry of Defense system. Based on the competence of the institution, directions of influence and awareness of the role of the stability of the transport component, a well-argued assumption is made about the uniquely important role of this institution.

Dynamic Investigations of Shared Bicycle Operators’ Competition Based on Profit Maximization

With the rise of the sharing economy, shared bicycles have become an important component of urban transportation. This paper explores the nonlinear dual oligopoly system for the Cournot model in the bike-sharing market; both operators have maximized profits as their competitive goals. The analysis of pivotal factors influencing passenger preferences, including pricing discounts and comfort levels, is meticulously depicted by a bifurcation diagram. A new chaotic attractor—the shared bicycle attractor—is discovered. The research results indicate that larger discounts and adjustment speeds can cause the system to be in a chaotic state, which is not conducive to the long-term development of operators, although discounts can indeed attract more passengers to a certain extent. On the other hand, the increase in the marginal cost of comfort loss can also make it difficult for enterprises to operate, which requires continuous technological innovation to improve the comfort of cycling.

Use of a Novel Whole Blood Separation and Transport Device for Targeted and Untargeted Proteomics.

There is significant interest in developing alternatives to traditional blood transportation and separation methods, which often require centrifugation and cold storage to preserve specimen integrity. Here we provide new performance findings that characterize a novel device that separates whole blood via lateral flow then dries the isolated components for room temperature storage and transport. Untargeted proteomics was performed on non-small cell lung cancer (NSCLC) and normal healthy plasma applied to the device or prepared neat. Significantly, proteomic profiles from the storage device were more reproducible than from neat plasma. Proteins depleted or absent in the device preparation were shown to be absorbed onto the device membrane through largely hydrophilic interactions. Use of the device did not impact proteins relevant to an NSCLC clinical immune classifier. The device was also evaluated for use in targeted proteomics experiments using multiple-reaction monitoring (MRM) mass spectrometry. Intra-specimen detection intensity for protein targets between neat and device preparations showed a strong correlation, and device variation was comparable to the neat after normalization. Inter-specimen measurements between the device and neat preparations were also highly concordant. These studies demonstrate that the lateral flow device is a viable blood separation and transportation tool for untargeted and targeted proteomics applications.

The role of biochar nanoparticles in reducing salt stress in tomato (Solanum lycopersicum) plants grown in fields

Soil salinization is a major threat to global food security, affecting over 20 % of cultivated land and reducing yields of important crops like tomato (Solanum lycopersicum). This field study explored the potential of biochar nanoparticles (BNPs) derived from rice straw to mitigate salt stress in tomato plants. The BNPs, prepared by pyrolysis at 350 ℃ and ball milling, had an average size of 130.32 nm. Tomato plants were grown for 12 weeks in soil with 0.2 % NaCl (w/w) and BNPs at 0.5, 1, or 2 ‰ w/w. Controls included unamended soil, soil with NaCl only, soil with BNPs only, and regular biochar with and without NaCl. BNPs significantly improved growth, biomass, and fruit yield of salt-stressed tomato plants. The 2 ‰ BNP treatment increased fruit yield by 115.05 % compared to salt stress alone. Stem fresh and dry weights increased by 35.64 % and 79.71 %, respectively, while root fresh and dry weights increased by 138.27 % and 68.35 %, respectively. BNPs enhanced fruit quality, with higher concentrations showing better effects. BNPs alleviated salt stress by regulating ion homeostasis, limiting Na translocation to leaves and fruits (reducing Na content by 35.15 % in leaves and 16.06 % in fruits), improving K content and Na/K ratio, and influencing Mg and P absorption and translocation. The nanoscale size, high surface area, and enhanced reactivity of BNPs allow them to penetrate plant tissues and interact with ion transport components. This study demonstrates the potential of BNPs as a sustainable approach for enhancing tomato salt tolerance in the field. Using crop residues for BNP production supports circular economy and sustainable agriculture. This approach holds potential for enhancing sustainable crop production under saline conditions, contributing to food security and the development of resilient agricultural systems in challenging environments.

Continuous augmentation of anaerobic digestion with electroactive microorganisms: Performance and stability

The performance and stability of a bioelectrochemical anaerobic digester (BeAD), continuously augmented with electroactive microorganisms (EAMs), were investigated. The BeAD showcased superior performance, sustaining the high COD removal efficiency and methane production rate of 76.5 % and 0.67 L/(L.d), respectively, in a stable state. Prominently, it exhibited remarkable resilience under hydraulic and organic shock loads, adeptly recuperating from disturbances up to 1000 % of its stable condition. This resilience of up to 300 % shock load was driven by increased levels of electron transport components such as quinones and riboflavins, which act as electron shuttles. However, after extreme shock exposures from 500 % to 1000 %, despite the spike in inhibitory by-products such as humic acids and ammonia, the upregulation of the mtr complex was pivotal in recovering and sustaining methane production. These insights emphasize the BeAD’s capability to bolster both performance and stability, thereby providing a potent strategy for practical application of bioelectrochemical systems.

Functional variations in efficiency of PSII during leaf ontogeny in the tropical plant Saraca asoca

Leaf ontogeny of tropical evergreen tree species lasts several months with changes in size, shape, colouration and internal tissue distribution of leaves. Leaf initiation in Saraca asoca generally occurs once in a year during February–April, followed by very limited leafing thereafter. We measured the rate of photosynthesis, chlorophyll a fluorescence, energy quenching and PSII functions during the leaf ontogeny process. Observations were taken up to 35 days after opening of lamina (DAOL). Significant increase in the synthesis and accumulation of photosynthetic pigments but negative net photosynthesis was noticed during initial days of the ontogeny. The leaf moved from heterotrophy to autotrophy with gradual improvement of PSII functions. The ratio of intercellular CO2 (Ci) and ambient CO2 (Ca) showed significant change at ≥11 DAOL. Increase in the age of the leaf (between 5 and 28 DAOL) caused decrease in O-J rise and corresponding increase in J-I and I-P rise as well as of fluorescence maximum (FM) of the OJIP curve. The improvement of the electron transport components of the donor side of PSII was seen with increase in the functional oxygen evolving complex. The functional improvements of the donor and acceptor side of PSII during leaf ontogeny are discussed.

Tunneling Mechanisms of Quinones in Photosynthetic Reaction Center–Light Harvesting 1 Supercomplexes

In photosynthesis, light energy is absorbed and transferred to the reaction center, ultimately leading to the reduction of quinone molecules through the electron transfer chain. The oxidation and reduction of quinones generate an electrochemical potential difference used for adenosine triphosphate synthesis. The trafficking of quinone/quinol molecules between electron transport components has been a long‐standing question. Here, an atomic‐level investigation into the molecular mechanism of quinol dissociation in the photosynthetic reaction center–light‐harvesting complex 1 (RC–LH1) supercomplexes from Rhodopseudomonas palustris, using classical molecular dynamics (MD) simulations combined with self‐random acceleration MD‐MD simulations and umbrella sampling methods, is conducted. Results reveal a significant increase in the mobility of quinone molecules upon reduction within RC–LH1, which is accompanied by conformational modifications in the local protein environment. Quinol molecules have a tendency to escape from RC–LH1 in a tail‐first mode, exhibiting channel selectivity, with distinct preferred dissociation pathways in the closed and open LH1 rings. Furthermore, comparative analysis of free energy profiles indicates that alternations in the protein environment accelerate the dissociation of quinol molecules through the open LH1 ring. In particular, aromatic amino acids form π‐stacking interactions with the quinol headgroup, resembling the key components in a conveyor belt system. This study provides insights into the molecular mechanisms that govern quinone/quinol exchange in bacterial photosynthesis and lays the framework for tuning electron flow and energy conversion to improve metabolic performance.

Molecular genetic characteristics of Streptococcus pneumoniae serogroups 15 and 11 representatives circulating in Russia and their relationship with global genetic lineages

Aim of the study. Genetic analysis of Streptococcus pneumoniae serogroups 15 and 11 circulating in Russia according to the following parameters: serotype affiliation; clonal complex (CC); presence of resistance and virulence determinants; relatedness to genetic lineages circulating in the world, and justification of inclusion of the actual serotypes of serogroups 15 and 11 in the future conjugate vaccine composition. Materials and methods. The study included whole genome data of S. pneumoniae serogroups 11 and 15. Results. Genomes of serogroup 15 strains from Russia are represented mainly by serotypes 15B and 15C, the majority of which belong to CC-1025 and CC-1262. CC-1025 is characterized by a more frequent association with invasive diseases. Representatives of CC-1025 and CC-1262 contain virulence determinants unique to these genetic lineages within the studied population of serogroup 15: oligopeptide transporters, fructose-specific PTS system, unique hydrolase variants, additional iron ion transporters, the gene of zinc metalloprotease ZmpC (activating human MMP9). The genomes of serogroup 11 are represented mainly by serotype 11A, the majority belong to CC-62 and CC-1012. The virulence determinants unique to CC-62 (within the studied serogroup 11) include bacteriocins, components of oligopeptide transport, flavin reductase-like protein (adhesin, also protects bacteria from oxidative stress), fucose processing operon, PsaA (adhesin, also a component of the ATP-binding cassette transporter that imports manganese ions). Conclusion. In the Russian Federation, serogroups 15 and 11 are the most common non-vaccine serogroups. No antimicrobial resistance determinants have been identified in the genomes of representatives of these serogroups. For each of the genetic lineages prevalent in Russia and associated with serogroups 15 and 11, unique virulence determinants within the studied serogroup have been identified, which may contribute to the success of these lineages. It is advisable to include serotypes 15B and 11A in vaccines promising for the Russian Federation.

A juvenile journey: Using a highly resolved 3D mooring array to investigate the roles of wind and internal tide forcing in across‐shore larval transport

AbstractThe across‐shore transport of meroplanktonic larvae is predominantly driven by coastal physical processes, resulting in episodic recruitment of benthic species. Historically, due to the sampling challenges associated with resolving these advective mechanisms across the continental shelf, relevant components of larval transport have been difficult to isolate and understand. We use three‐dimensional temperature and velocity data from an array of 29 moorings to identify fundamental physical processes that could have generated successful across‐shore transport and settlement of meroplankton. The dense spatial and temporal sampling from this array allows us to use Lagrangian particle tracking to estimate the influences of wind conditions and the internal tide on the across‐shore transport of planktonic larvae. Settlement was found to be episodic at all depths studied. Above mid‐water, modeled larvae were successfully transported onshore by the internal tide during wind relaxations. Surprisingly, abundant pulses of shallow‐water larvae were supplied to the coast on occasions when strong, upwelling‐favorable winds (> 4 m s−1) drove offshore‐flowing surface waters, revealing a complex, potentially topographically influenced flow. These intense upwelling‐favorable winds also contributed to subsurface onshore flows that created large pulses of larval settlement in deeper waters (> 20 m). Our analyses from this highly resolved data set provide novel insights into the interactions of physical drivers in creating episodic pulses of coastal larval recruitment.

Flying foxes optimization with reinforcement learning for vehicle detection in UAV imagery

Intelligent transportation systems (ITS) are globally installed in smart cities, which enable the next generation of ITS depending on the potential integration of autonomous and connected vehicles. Both technologies are being tested widely in various cities across the world. However, these two developing technologies are vital in allowing a fully automatic transportation system; it is necessary to automate other transportation and road components. Unmanned aerial vehicles (UAVs) or drones are utilized for many surveillance applications in the ITS. Detecting on-ground vehicles in drone images is significant for disaster rescue operations, traffic and parking management, and navigating uneven territories. This study presents a flying foxes optimization with deep learning-based vehicle detection and classification model on aerial images (FFODL-VDCAI) technique for ITS application. The main objective of the FFODL-VDCAI technique is to automate and accurately classify vehicles that exist in aerial images. Three primary processes are involved in the presented FFODL-VDCAI technique. Initially, the FFODL-VDCAI approach utilizes YOLO-GD (Ghost-Net and Depthwise convolution) for vehicle detection, where the YOLO-GD uses lightweight Ghost Net in place on the backbone network of YOLO-v4 and interchanges the conventional convolutional with depthwise separable convolutional and pointwise convolutional. Next, the FFO technique is used for hyperparameter tuning the Ghost Net technique. Finally, a deep Q-network (DQN) based reinforcement learning technique is used to classify detected vehicles effectively. A comprehensive simulation analysis of the FFODL-VDCAI methodology is conducted on the UAV image dataset. The performance validation of the FFODL-VDCAI methodology exhibited superior values of 96.15% and 92.03% under PSU and Stanford datasets concerning various aspects.

Accurate Identification of Periplasmic Urea-binding Proteins by Structure- and Genome Context-assisted Functional Analysis

ABC transporters are ancient and ubiquitous nutrient transport systems in bacteria and play a central role in defining lifestyles. Periplasmic solute-binding proteins (SBPs) are components that deliver ligands to their translocation machinery. SBPs have diversified to bind a wide range of ligands with high specificity and affinity. However, accurate assignment of cognate ligands remains a challenging problem in SBPs. Urea metabolism plays an important role in the nitrogen cycle; anthropogenic sources account for more than half of global nitrogen fertilizer. We report identification of urea-binding proteins within a large SBP sequence family that encodes diverse functions. By combining genetic linkage between SBPs, ABC transporter components, enzymes or transcription factors, we accurately identified cognate ligands, as we verified experimentally by biophysical characterization of ligand binding and crystallographic determination of the urea complex of a thermostable urea-binding homolog. Using three-dimensional structure information, these functional assignments were extrapolated to other members in the sequence family lacking genetic linkage information, which revealed that only a fraction bind urea. Using the same combined approaches, we also inferred that other family members bind various short-chain amides, aliphatic amino acids (leucine, isoleucine, valine), γ-aminobutyrate, and as yet unknown ligands. Comparative structural analysis revealed structural adaptations that encode diversification in these SBPs. Systematic assignment of ligands to SBP sequence families is key to understanding bacterial lifestyles, and also provides a rich source of biosensors for clinical and environmental analysis, such as the thermostable urea-binding protein identified here.

Time-fractionated anisotropic osmosis with bilateral total variation for effective shadow mitigation in image processing

This work introduces an innovative strategy for mitigating shadow effects in images through the utilization of a time-fractionated anisotropic osmosis equation. The method goes beyond conventional approaches by incorporating a newly derived bilateral total variation (BTV) term, coupled with a nonlinear anisotropic transport component. Theoretical insights are rigorously presented, accompanied by a meticulous exposition of the discretization scheme based on finite differences. In addition to the theoretical foundation, the paper conducts comprehensive numerical experiments to validate the proposed model's efficacy. These experiments not only affirm the qualitative advantages of the anisotropic osmosis model but also provide quantitative evidence of its superiority over existing state-of-the-art techniques.