Browse Articles

Adaptive fixed-time fault-tolerant trajectory tracking control for disturbed robotic manipulator

This article introduces a fixed-time trajectory control method for robotic manipulators, aimed at improving trajectory precision despite external disturbances, actuator faults, and uncertainties. Initially, a fast fixed-time nonsingular terminal sliding surface (FFNTSS) is utilized, featuring a bounded convergence time that remains unaffected by the initial conditions. This sliding surface not only prevents the occurrence of singularity but also guarantees fast convergence. Subsequently, building upon the FFNTSS and adaptive methodology, a novel approach termed continuous adaptive fixed-time nonsingular terminal sliding mode fault-tolerant control (CAFNTSMFTC) is introduced. According to the Lyapunov theorem, rigorous analysis demonstrates that the sliding mode variables and tracking errors of the closed-loop system converge to a small neighborhood of the origin within a fixed-time frame. Moreover, by approximating the square of the uncertainty’s upper bound, the devised CAFNTSMFTC approach eliminates the need for the boundary layer commonly imposed in existing adaptive fixed-time control approaches. Lastly, comprehensive comparative simulations are conducted employing the PUMA560 robot. These simulations validate the proposed control strategy, underscoring its ability to achieve precise trajectory tracking and fast convergence, even when facing uncertainties, disturbances, and actuator faults. Moreover, the proposed control strategy for the robot manipulator is distinguished by its continuity and demonstrates dynamics in which chattering is mitigated.

How a Single Atom Influences the Spatiotemporal Response of Flexible MOFs: Insights from Theory and Experiment

Screening macrocyclic peptide libraries by yeast display allows control of selection process and affinity ranking

Estimation of bimodal soil-water characteristics curve under wetting process

Soil-water characteristics curve (SWCC) is hysteretic. The hysteretic curves represent the soil conditions during drying and wetting processes. Almost all failure of geotechnical structures, particularly in soils with dual porosity (bimodal soils) occurs during soil wetting, making the wetting curve more relevant to geotechnical applications than the drying curve. Still, due to the high-cost implications, time require, and difficulties associated with measuring SWCC under wetting process, the wetting curve has been continuously neglected. This leads to analyses that do not reflect the actual soil condition, which may result in structural failure. Although bimodal soils are encountered in many areas across the globe, there is no mathematical model for estimating bimodal SWCC under wetting process. This work developed a new mathematical equation to estimate a bimodal SWCC under wetting process. The proposed model also has parameters with physical meaning in relation to the variables of the wetting SWCC, which is very important in practical applications and numerical analyses. Six soil types were used in the model validation. The overall model performance has been evaluated through statistical methods using the coefficient of determination (R2) and Root Mean Square Error (RMSE). The evaluation also indicates a good performance of the model, with an average RMSE of 0.0263 and an average R2 of 0.9945 for the six soil samples used in the validation. Given the significance of wetting-induced failures, the proposed model is highly relevant in engineering applications.

Polyglutamylation of microtubules drives neuronal remodeling

Abstract Developmental remodeling shapes neural circuits via activity-dependent pruning of synapses and axons. Regulation of the cytoskeleton is critical for this process, as microtubule loss via enzymatic severing is an early step of pruning across many circuits and species. However, how microtubule-severing enzymes, such as spastin, are activated in specific neuronal compartments remains unknown. Here, we reveal that polyglutamylation, a post-translational tubulin modification enriched in neurons, plays an instructive role in developmental remodeling by tagging microtubules for severing. Motor neuron-specific gene deletion of enzymes that add or remove tubulin polyglutamylation—TTLL glutamylases vs. CCP deglutamylases—accelerates or delays neuromuscular synapse remodeling in a neurotransmission-dependent manner. This mechanism is not specific to peripheral synapses but also operates in central circuits, e.g., the hippocampus. Thus, tubulin polyglutamylation acts as a cytoskeletal rheostat of remodeling that shapes neuronal morphology and connectivity.

Effects of age on the neural correlates of auditory working memory in cochlear implant users

Following a conversation in a noisy environment is challenging, especially for individuals who received cochlear implants (CIs) to remediate severe-to-profound hearing loss. CI users likely work harder than their normal-hearing counterparts to understand speech in adverse listening conditions. Recruiting cognitive resources can be taxing and may interfere with attentional regulation and working memory processes. Few studies have, however, examined the impact of CIs on the neural correlates of attention and working memory. We used a high-density electroencephalogram to investigate behavioural and neural correlates of auditory attention and working memory in 14 CI users and age-matched normal hearing (NH) controls (age ranges: 21–75). All participants completed an auditory n-back task with zero- and two-back memory load conditions. Behaviourally, CI users were slower in identifying targets during the two-back condition, especially older adults. The sensory-evoked responses were reduced in CI users compared to NH. With increasing memory load, younger CI users and NH controls displayed decreased amplitudes, while older CI users showed no change in amplitude. We also observed reduced frontal theta synchrony and greater alpha/beta desynchrony in CI users where alpha/beta in the left inferior frontal gyrus was related to slower response times in CI users. Attenuated frontotemporal connectivity was also evident compared to NH. These findings suggest that CI users adapt to higher task demands by allocating more attentional resources while encoding and maintaining stimuli in working memory. This pattern of activity potentially indexes a delay in identification and possible neural correlates of cognitive deficits while aging with a CI.

Excited State Dynamics of Odd [<i>n</i>]Cumulenes: Chain Length and Conformational Effects

ETMR stem-like state and chemo-resistance are supported by perivascular cells at single-cell resolution

Abstract Embryonal tumor with multilayered rosettes (ETMR) is a lethal embryonal brain tumor entity. To investigate the intratumoral heterogeneity and cellular communication in the tumor microenvironment (TME), we analyze in this work single-cell RNA sequencing of about 250,000 cells of primary human and murine ETMR, in vitro cultures, and a 3D forebrain organoid model of ETMR, supporting the main findings with immunohistochemistry and spatial transcriptomics of human tumors. We characterize three distinct malignant ETMR subpopulations - RG-like, NProg-like and NB-like - positioned within a putative neurodevelopmental hierarchy. We reveal PDGFRβ+ pericytes as key communication partners in the TME, contributing to stem cell signaling through extracellular matrix-mediated interactions with tumor cells. PDGF signaling is upregulated in chemoresistant RG-like cells in vivo and plays a role in recruiting pericytes to ETMR TME by finalizing a signaling cascade which promotes the differentiation of non-malignant radial glia cells, derived from our 3D model, into pericyte-like cells. Selective PDGFR-inhibition blocked the lineage differentiation into pericytes in vitro and reduced the tumor cell population in vivo. Targeting ETMR-pericyte interactions in the TME presents a promising therapeutic approach.

Organisational kindness and compassion: what are the barriers, enablers and outcomes for clients and stakeholders?

Unkind bureaucratic policies such as the Australian Robodebt policy, which targeted welfare recipients with automatic debt letters, and are geared towards economic savings, can significantly harm those impacted by them. Compassion and kindness are receiving increased research attention related to how organisations work internally. However, a greater investment in studies is needed to increase understandings about how compassion and kindness can underpin interactions with external stakeholders. Addressing this research gap, we aimed to identify barriers, enablers and outcomes to organisational kindness and compassion informed by the literature, and to propose future research directions related to organisational kindness and compassion towards external stakeholders. A search of four scholarly databases identified 25 relevant publications. Thematic analysis of included publications revealed barriers of commodification, personal risks, dysfunctional environments, inauthentic attempts at, and a lack of understanding of the need to be compassionate or kind. Enablers included building compassion into organisational policies, processes, practices and activities, compassion contagion, training of staff, leading with compassion, and kind and compassionate communication. Outcomes of kindness included building positive and healthy relationships with stakeholders, supporting positive experiences among stakeholders, and contributing to an organisation’s profitability, productivity, performance and standing in the community. We conclude by recognising that kindness is essential for ongoing trust in health and social care institutions and government policy.

Iron regulatory pathways differentially expressed during Madurella mycetomatis grain development in Galleria mellonella

Abstract Mycetoma is a chronic granulomatous infection of the subcutaneous tissue, most often caused by the fungal pathogen Madurella mycetomatis. Characteristic of the infection is the formation of grains. However, knowledge of the function and formation of the grain is limited. Here, we use a Galleria mellonella larvae infection model and transcriptomic profiling to identify processes associated with M. mycetomatis grain formation. Larvae were infected with M. mycetomatis and, after 4, 24, 72 and 168 h post-inoculation, RNA was extracted from larval content and sequenced. We found that 3498 G. mellonella and 136 M. mycetomatis genes were differentially expressed during infection. In particular, genes encoding proteins related to iron transport were highly expressed by both G. mellonella (transferrin and ferritin) and M. mycetomatis (SidA, SidD and SidI). LC-MS/MS analysis of M. mycetomatis cultured under iron-limiting conditions revealed the presence of SidA and SidD orthologs, and concurrent RP-HPLC and LC-MS identified a singly charged, putative siderophore in culture supernatant. Furthermore, we show that M. mycetomatis can obtain iron from holoferritin. Thus, our results highlight the importance of iron acquisition pathways during grain formation, suggesting potential avenues for development of new diagnostic and therapeutic strategies for mycetoma.

RETRACTED: Application of IRSA-BP neural network in diagnosing diabetes

Within the healthcare sector, the application of machine learning is gaining prominence, notably enhancing the efficiency and precision of diagnostic procedures. This study focuses on this key area of diabetes prediction and aims to develop an innovative prediction method. Using the data set published by Kare, this paper constructs and compares various intelligent systems based on multilayer algorithms, and specifically introduces improved reptile search algorithm (IRSA) to optimize the weight and threshold initialization of traditional backpropagation (BP) neural networks. This improvement aims to improve the network performance and accuracy in diabetes detection. In the study, the IRSA-BP hybrid algorithm and many other machine learning algorithms were used for diabetes prediction, and the algorithm performance was comprehensively evaluated using multiple classification metrics. The experimental results showed that the IRSA-BP algorithm performed the best among all the evaluated algorithms, with an accuracy of up to 83.6%, showing its superior performance in diabetes prediction. Therefore, the IRSA-BP classifier has an important potential for application in the medical field. It can assist medical professionals to identify diabetes risk earlier and assess the condition more accurately, thus improving diagnostic efficiency and accuracy. This is important for early intervention and treatment of patients with diabetes and to improve their health status and quality of life.

The mitochondrial methylation potential gates mitoribosome assembly

Abstract S-adenosylmethionine (SAM) is the principal methyl donor in cells and is essential for mitochondrial gene expression, influencing RNA modifications, translation, and ribosome biogenesis. Using direct long-read RNA sequencing in mouse tissues and embryonic fibroblasts, we show that processing of the mitochondrial ribosomal gene cluster fails in the absence of mitochondrial SAM, leading to an accumulation of unprocessed precursors. Proteomic analysis of ribosome fractions revealed these precursors associated with processing and assembly factors, indicating stalled biogenesis. Structural analysis by cryo-electron microscopy demonstrated that SAM-dependent methylation is required for peptidyl transferase centre formation during mitoribosome assembly. Our findings identify a critical role for SAM in coordinating mitoribosomal RNA processing and large subunit maturation, linking cellular methylation potential to mitochondrial translation capacity.

Tissue tropism of toxic metals in northern quolls (Dasyurus hallucatus) and northern brown bandicoots (Isoodon macrourus) on Groote Eylandt, Australia

Mining is an essential part of the Australian economy, but can create environmental concerns due to toxic metal pollution. Surrounding active manganese (Mn) mining sites, such as those on Groote Eylandt, Australia, toxic metal exposure leads to variation in the internal distribution within animals (i.e., tissue tropism) and can exert long-term health effects on wildlife. We aimed to determine if hair of the endangered northern quoll (Dasyurus hallucatus) or of the northern brown bandicoot (Isoodon macrourus) would be sufficient to monitor internal contamination. We analyzed nine toxic metals (Al, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) in eight tissues/organs (cerebellum, hair, kidney, liver, lung, neocortex, olfactory bulb, testes) of quolls and bandicoots using inductively coupled plasma – optical emission spectroscopy (ICP-OES). We found six significant positive and five significant negative correlations between the concentration of metals in internal tissues and the concentration in hair in quolls, and four significant relationships in bandicoots, all negative. We also found that the concentrations of metals in quoll tissues/organs, except for hair, were significantly higher than in bandicoots. Differences in the magnitude and direction of these relationships may reflect differences in life histories or metabolic rates. The concentration of Mn in hair was significantly higher in quolls collected near the mining sites than in quolls collected at distant locations, and this also appeared to be the case for bandicoots, but we lacked a sufficient sample size to demonstrate this statistically. The concentration of Al in the hair of quolls was also significantly higher near the mining sites. The concentration of Mn in the hair of quolls reflected the concentration of Mn in the cerebellum and neocortex, while the concentration of Al in the hair of quolls reflected Al concentration in the cerebellum, neocortex, liver, and kidney. We conclude that hair analyzed with ICP-OES is an effective biomarker of local exposure to Mn and Al for quolls, and that hair Mn and Al concentration in quolls can be used as a biomarker of concentration of some tissues, such as cerebellum and neocortex. These findings point to hair as a valuable non-invasive method for assessing metal exposure in wildlife that can be useful for management and conservation efforts.

Topochemical Ring-Opening Polymerization of an Oxathianethione

Low frequency oscillations – neural correlates of stability and flexibility in cognition

Abstract Cognitive processing relies on the brain’s ability to balance flexibility for encoding new information with stability for maintaining it. We examined these dynamics in three magnetoencephalography (MEG) datasets of visuospatial working memory (vsWM) tasks. Across all tasks, we identified four distinct networks in the theta and alpha bands, which were used to define functional states. Optimal transitioning rate between states was associated with better cognitive performance. Further, two of the states were linked to flexibility and stability, respectively: an encoding state dominated by a posterior theta and a maintenance state dominated by a dorsal alpha. We simulated the states in an in-silico model with biologically realistic cortical connectivity. The model, featuring spiking and oscillatory cortical layers interacting via phase-amplitude coupling, demonstrated how frequency and spatial region could modulate information flow. Our findings suggest a cognitive control mechanism, where selective transitions between large-scale networks optimize information flow, enabling both stable and flexible visual representations.

National trends in utilization and outcomes of elective open and minimally invasive colostomy reversal: A NSQIP analysis

Background Minimally invasive approach for reversal of Hartmann’s procedure remains understudied. This study examined the outcomes associated with open and minimally invasive approaches for colostomy reversal in a national cohort. Methods The 2012–2022 American College of Surgeons National Surgical Quality Improvement Program participant use file data was queried to identify all adult (≥18 years) patients undergoing elective open or minimally invasive colostomy takedown. Multivariable regression models were developed to assess the associations between operative modalities and outcomes of interest, including overall complications (cardiac, respiratory, infectious, wound, renal and thromboembolic postoperative sequelae as well as reoperation and transfusion), operative duration, postoperative length of stay, and 30-day Readmissions. Results Among the 20,163 patients who underwent colostomy takedown during the study period, 6,180 (30.7%) had a minimally invasive reversal. Utilization of minimally invasive colostomy reversal increased from 18.2% in 2012 to 41.9% in 2022 (nptrend &lt; 0.001). Following risk adjustment, minimally invasive colostomy takedown was associated with reduced odds of overall complications compared to the open approach (AOR 0.56, 95% CI 0.51–0.62). The minimally invasive approach was associated with decremental operative duration by 16.9 minutes (95% CI 13.6 to 20.2 minutes) and postoperative length of stay by 1.70 days (95% CI 1.56 to 1.84 days), as well as decreased odds of 30-day readmission (AOR 0.75, 95% CI 0.67–0.85). Conclusions Over the past decade, utilization of minimally invasive colostomy reversal has more than doubled and yielded lower overall complication rates compared to the open approach. Our findings suggest that the minimally invasive approach may be appropriate for colostomy takedown in suitable cases.

Super-resolution upgrade for deep tissue imaging featuring simple implementation

Abstract Deep tissue imaging with high contrast close to or even below the optical resolution limit is still challenging due to optical aberrations and scattering introduced by dense biological samples. This results in high complexity and cost of microscopes that can facilitate such challenges. Here, we demonstrate a cost-effective and simple to implement method to turn most two-photon laser-scanning microscopes into a super-resolution microscope for deep tissue imaging. We realize this by adding inexpensive optical devices, namely a cylindrical lens, a field rotator, and a sCMOS camera to these systems. By combining two-photon excitation with patterned line-scanning and subsequent image reconstruction, we achieve imaging of sub-cellular structures in Pinus radiata , mouse heart muscle and zebrafish. In addition, the penetration depth of super-resolved imaging in highly scattering tissue is considerably extended by using the camera’s lightsheet shutter mode. The flexibility of our method allows the examination of a variety of thick samples with a variety of fluorescent markers and microscope objective lenses. Thus, with a cost-efficient modification of a multi-photon microscope, an up to twofold resolution enhancement is demonstrated down to at least 70 μ m deep in tissue.

Astragaloside IV combined with quercetin attenuates silica-induced pulmonary fibrosis by promoting autophagy and suppressing pyroptosis

Confirmation bias through selective readout of information encoded in human parietal cortex

Abstract Decision-makers often process new evidence selectively, depending on their current beliefs about the world. We asked whether such confirmation biases result from biases in the encoding of sensory evidence in the brain, or alternatively in the utilization of encoded evidence for behavior. Human participants estimated the source of a sequence of visual-spatial evidence samples while we measured cortical population activity with magnetoencephalography. Halfway through the sequence, participants were prompted to judge the more likely source category. We find that processing of subsequent evidence depends on its consistency with the previously chosen category. Evidence encoded in parietal cortex contributes more to the estimation report when that evidence is consistent with the previous choice compared to when it contradicts that choice. Our results indicate that information contradicting pre-existing beliefs has little impact on subsequent behavior, despite being precisely encoded in the brain. This provides room for deliberative control to counteract confirmation biases.

Impact of feeding strategies on the welfare and behaviour of horses in groups: An experimental study

Finding feeding strategies that meet horses’ needs without compromising health is essential for optimising welfare, particularly in group housing, where limited hay availability increases aggression and injury risks. Recently, two strategies have emerged: portioning daily intake into smaller, frequent meals using time-controlled hay racks, or slowing intake with “slow-feeders.” However, the effects of such management practices on horse behaviour remain underexplored. We conducted a cross-over study with 18 mares divided into four groups to compare three feeding strategies: “traditional” (3 of 2-hours meals during daylight, TD), “portioned” (6 of 1-hour meals spread over 24h, PO) and “slow-feeding” (ad libitum hay covered by a net, SF). Each treatment included 3 weeks of habituation and 2 weeks of data collection. We continuously recorded social interactions for 15 hours and noted the position and activity of all horses every 15 minutes. We also recorded injuries periodically and measured the lying behaviour using accelerometers. We analysed the effects of treatment on agonistic and affiliative behaviour within groups using generalised mixed model and selected the best model using AIC. We used the same procedure for the injuries and lying behaviour at the individual level. Horses in SF exhibited activity time budgets resembling natural conditions, while TD and PO resulted in time budgets similar to box-stall systems, despite the loose-housing system. Surprisingly, our results suggest that PO may be more frustrating for the horses than TD. Indeed, there was no significant reduction of agonistic behaviours during feeding times in PO compared to TD and lying behaviour tended to be impaired in PO (−11.3 min/day, 95% CI [−25.8; 3.1]) compared to SF and TD (37.5 min/day on average). In our study, portioning into smaller, more frequent meals did not reduce the stress in horses. This highlights the need for further research on portioning strategies to find optimal feeding management. In addition, slow-feeding was a more suitable feeding strategy for horses than portioning. However, more research is required to substantiate the initial findings on the efficacy of ad libitum slow-feeding on the horse’s health and behaviour.