Plastic Capacity Research Articles

Experimental and numerical investigation of novel triangular headed one-sided bolted T-stub connections

The reliable one-sided bolts constitute a vital component of fully bolted joints in demountable steel structures. In this study, an innovative triangular headed one-sided bolt (THOB) based on the traditional hexagon headed bolt (HHB) was proposed, and the tensile performance of T-stubs using the THOBs has been investigated through experimental and numerical approaches. Monotonic tensile tests were performed on 25 THOB bolted T-stubs to analyze the failure modes and load-carrying performance of the specimens. The test results disclosed that, beyond the three typical failure modes stipulated in the Eurocode 3, the specimens exhibited a characteristic failure mode, namely, limit groove pull-off failure. Finite element models, validated by the test results, were employed for the parametric analysis to compare the load-carrying performance of THOB bolted T-stubs with that of HHB bolted T-stubs. The finite element analysis results indicated that the average ratio of the plastic load-carrying capacity of THOB bolted T-stubs to HHB bolted T-stubs was close to 0.88. Furthermore, the load-carrying capacity of THOB bolted T-stubs was evaluated using existing specifications for comparison with the experimental and numerical results, and Eurocode 3 calculations for the plastic load-carrying capacities of THOB bolted T-stubs demonstrated a commendable level of precision. Finally design recommendations were put forward based on the test and finite element analysis results.

A population of Vasa2 and Piwi1 expressing cells generates germ cells and neurons in a sea anemone

Germline segregation, essential for protecting germ cells against mutations, occurs during early embryogenesis in vertebrates, insects and nematodes. Highly regenerative animals (e.g., cnidarians), however, retain stem cells with both germinal and somatic potentials throughout adulthood, but their biology and evolution remain poorly understood. Among cnidarians (e.g., sea anemones, jellyfish), stem cells are only known in few hydrozoans (e.g., Hydra). Here, we identify and characterize a rare, multipotent population of stem and/or progenitor cells expressing the conserved germline and multipotency proteins Vasa2 and Piwi1 in the sea anemone Nematostella vectensis. Using piwi1 and vasa2 transgenic reporter lines, we reveal that the Vasa2+/Piwi1+ cell population generates not only gametes, but also a diversity of proliferative somatic cells, including neural progenitors, in juveniles and adults. Our work has uncovered a multipotent population of Vasa2+/Piwi1+ stem/progenitor cells that forms the cellular basis to understand body plasticity and regenerative capacities in sea anemones and corals.

Numerical investigation on plastic hinge behavior of hybrid steel-FRP reinforced concrete columns

This paper presents a numerical study on the plastic hinge behavior and rotation capacity of concrete columns reinforced with a combination of steel bars and fiber-reinforced polymer (FRP) bars. A meso-scale numerical model, which considers the internal heterogeneity of concrete and bond behavior between concrete and longitudinal reinforcements, was developed and validated. The failure modes, lateral load-displacement responses, and the physical plastic hinge lengths of hybrid steel-FRP reinforced concrete (SFRC) columns were investigated and compared with those of conventional steel-reinforced concrete columns. The results indicated that the steel yielding zone and curvature localization zone of SFRC columns with FRP longitudinal bars were enlarged, due to the relatively low modulus of FRP bars. After that, a parametric analysis was performed to study the plastic hinge length of SFRC columns with respect to the nominal area ratio of FRP longitudinal bars, shear span-to-depth ratio, axial load ratio, and longitudinal reinforcement ratio. A new empirical model was proposed to predict the equivalent plastic hinge length, which was subsequently integrated into an analytical method for predicting the ultimate rotation. The comparison of predictions with simulation and test results demonstrated the accuracy of both the proposed empirical model and analytical method.

Molecular regulation of reversible cardiac remodeling: lessons from species with extreme physiological adaptations.

Some vertebrates evolved to have a remarkable capacity for anatomical and physiological plasticity in response to environmental challenges. One example of such plasticity can be found in the ambush-hunting snakes of the genus Python, which exhibit reversible cardiac growth with feeding. The predation strategy employed by pythons is associated with months-long fasts that are arrested by ingestion of large prey. Consequently, digestion compels a dramatic increase in metabolic rate and hypertrophy of multiple organs, including the heart. In this Review, we summarize the post-prandial cardiac adaptations in pythons at the whole-heart, cellular and molecular scales. We highlight circulating factors and cellular signaling pathways that are altered during digestion to affect cardiac form and function and propose possible mechanisms that may drive the post-digestion regression of cardiac mass. Adaptive physiological cardiac hypertrophy has also been observed in other vertebrates, including in fish acclimated to cold water, birds flying at high altitudes and exercising mammals. To reveal potential evolutionarily conserved features, we summarize the molecular signatures of reversible cardiac remodeling identified in these species and compare them with those of pythons. Finally, we offer a perspective on the potential of biomimetics targeting the natural biology of pythons as therapeutics for human heart disease.

The digital twin in neuroscience: from theory to tailored therapy.

Digital twins enable simulation, comprehensive analysis and predictions, as virtual representations of physical systems. They are also finding increasing interest and application in the healthcare sector, with a particular focus on digital twins of the brain. We discuss how digital twins in neuroscience enable the modeling of brain functions and pathology as they offer an in-silico approach to studying the brain and illustrating the complex relationships between brain network dynamics and related functions. To showcase the capabilities of digital twinning in neuroscience we demonstrate how the impact of brain tumors on the brain's physical structures and functioning can be modeled in relation to the philosophical concept of plasticity. Against this technically derived backdrop, which assumes that the brain's nonlinear behavior toward improvement and repair can be modeled and predicted based on MRI data, we further explore the philosophical insights of Catherine Malabou. Malabou emphasizes the brain's dual capacity for adaptive and destructive plasticity. We will discuss in how far Malabou's ideas provide a more holistic theoretical framework for understanding how digital twins can model the brain's response to injury and pathology, embracing Malabou's concept of both adaptive and destructive plasticity which provides a framework to address such yet incomputable aspects of neuroscience and the sometimes seemingly unfavorable dynamics of neuroplasticity helping to bridge the gap between theoretical research and clinical practice.

Investigation of metaplasticity associated with transcranial focused ultrasound neuromodulation in humans.

Low intensity transcranial focused ultrasound stimulation (TUS) is a novel technique for non-invasive brain stimulation (NIBS). TUS delivered in a theta (5Hz) burst pattern (tbTUS) induces plasticity in the human primary motor cortex (M1) for 30-60 minutes, showing promise for therapeutic development. Metaplasticity refers to activity-dependent changes in neural functions governing synaptic plasticity; depotentiation is the reversal of long-term potentiation (LTP) by a subsequent protocol with no effect alone. Metaplasticity can enhance plasticity induction and clinical efficacy of NIBS protocols. In our study, we compared four NIBS protocol combinations to investigate metaplasticity on tbTUS in humans of either sex.We delivered four interventions: 1) sham continuous theta burst stimulation with 150 pulses (cTBS150) followed by real tbTUS (tbTUS only), 2) real cTBS150 followed by sham tbTUS (cTBS only), 3) real cTBS150 followed by real tbTUS (metaplasticity), and 4) real tbTUS followed by real cTBS150 (depotentiation). We measured motor-evoked potential amplitude, short-interval intracortical inhibition, long-interval intracortical inhibition, intracortical facilitation, and short-interval intracortical facilitation before and up to 90 minutes after plasticity intervention.Plasticity effects lasted at least 60 minutes longer when tbTUS was primed with cTBS150 compared to tbTUS alone. Plasticity was abolished when cTBS150 was delivered after tbTUS. cTBS150 alone had no significant effect. No changes in M1 intracortical circuits were observed.Plasticity induction by tbTUS can be modified in manners consistent with homeostatic metaplasticity and depotentiation. This substantiates evidence that tbTUS induces LTP-like processes and suggest that metaplasticity can be harnessed in the therapeutic development of TUS.Significance statement Low intensity transcranial focused ultrasound stimulation (TUS) is a novel technique for non-invasive brain stimulation (NIBS). Compared to current forms of NIBS, TUS can target deep regions of the brain, such as the basal ganglia and thalamus, with high focality. This is promising for therapeutic development. Neuroplasticity refers to the strengthening or weakening of neural connections based on neural activity. Neural activity can also change the brain's capacity for future plasticity via the process of metaplasticity. This study was the first to characterize the effects of metaplasticity on TUS-induced neuroplasticity, demonstrating that metaplastic processes can enhance and abolish TUS effects. The findings increase understanding of the mechanisms of TUS-induced plasticity and inform future therapeutic development of TUS.

Multi-deformable interpenetrating network thermosensitive hydrogel fluorescent device for real-time and visual detection of nitrite

Functionalized thermosensitive hydrogel materials exhibit excellent properties for the fabrication of sensing devices that enable real-time visual detection of food safety duo to their good plasticity and powerful loading capacity. Here, a ratiometric fluorescent device based on an interpenetrating network (IPN) thermosensitive hydrogel was designed to embed functionalized Au nanoclusters (Au NCs) and Blue Carbon dots (BCDs) composites in a multi-network structure to build a sensitive hazardous material nitrite (NO2-) chemsensor. The hydrogel was utilized poloxamer 407 (P407), lignin and cellulose to form stable IPN structure, which resulted in complementation and synergy, thereby strengthening its porous network structure. The combination of fluorescent nanoprobes with the porous network structure has the potential to enhance stable fluorescence signals and improve sensing sensitivity. Moreover, the thermosensitive liquid-solid transition characteristics of the hydrogel facilitate its preparation into diverse sensing devices following curing at room temperature. The hydrogel device, when combined with a smartphone system, converted image information into data information, thereby enabling the accurate quantification of NO2- with a detection limit of 9.38 nM in 2 s. The designed multi-functional hydrogel device is capable of real-time differentiation of NO2- dosage with the naked eye, offering a high-contrast, rapid-response sensing methodology for visual assessment of food freshness. This research contributes to the expansion of hydrogel materials applications and the detection of hazardous materials in food safety.

Teriflunomide, cognition and MRI: A longitudinal study

BackgroundAs cognitive impairment in multiple sclerosis (MS) is a frequent and disabling symptom, it is particularly important to identify treatments that have proven efficacy in this aspect of the disease. Several disease-modifying therapies for MS have been evaluated and shown to have a potential effect on cognition and its neurobiological correlates, but to date there is very little data on Teriflunomide (TRF). The aim of this study is to explore the influence of TRF on comprehensive cognitive function and its MRI correlations (global and focal brain volume) in relapsing-remitting multiple sclerosis (RRMS) after two years of therapy. MethodsTwenty-four patients with RRMS were evaluated at baseline and after two years of treatment with BCcogSEP, a French translation of the Brief Repeatable Battery (BRB-N) including 3 additional tests. We explored the performance evolution for each test and correlation with MRI data for all patients. We also differentiated MS patients with and without cognitive impairment. ResultsAfter two years of treatment, an improvement is observed at the Selective Reminding Test for mean number of words (p = 0.044), learning (p = 0.018), and delayed recall (p = 0.002) and at GoNoGo task (p = 0.022). At MRI, the corpus callosum volume variation correlates positively with SRT total recall test (p = 0,047). Intergoup analysis shows that the evolution of group performance differs only for the SRT total recall test. The comparison of patients with or without cognitive impairment showed a clear difference in white matter substance volume (p = 0,003) and in the Percentage Brain Volume Change (p = 0,016). ConclusionResults suggest that TRF treatment in RRMS has a positive effect in cognitive function, and specifically on long term verbal memory and inhibition. Neuroimaging data suggest a link between cognition and global and focal white matter volume, particularly in the corpus callosum which is involved in anatomical disconnection syndrome and therefore brain plasticity capacities.

Geotechnical Assessment of Seismic Vulnerability in the Built Environment of Fako Division, South West Region of Cameroon

Introduction: Volcanic earthquakes may trigger severe hazards with considerable impact on the natural and built environment and the surrounding population. Aim: Evaluate the geotechnical characteristics of soils in Fako division to estimate their seismic vulnerability and recommend suitable stabilization techniques to enhance the safety and resilience of built environments. Place and Duration of Study: This study was conducted over a period of 12 months beginning from June 2022 to May 2023. Methodology: It employed a multi-criteria geotechnical approach, involving soil sampling, laboratory analysis, and seismic risk analysis. Soil samples collected from various locations within the study area, were subjected to laboratory tests to determine their plasticity (Atterberg limits) and load-bearing capacity (California Bearing Ratio - CBR). Historical data analysis and seismic hazard mapping were used to assess seismic vulnerability which helped to identify highly susceptible and unstable areas that may require engineered interventions. Results: The findings revealed significant variations in soil plasticity and load-bearing capacity, correlating with observed settlement and instability issues in the region. Historical seismic events, highlighted significant structural damage in areas with high plasticity and low CBR values, underscoring the necessity for robust soil stabilization measures (geotechnical interventions) to mitigate seismic risks and enhance the resilience and safety of structures, reducing the risk of settlement and instability within the Mount Cameroon area, particularly Fako Division.

Ocean warming and acidification adjust inter- and intra-specific variability in the functional trait expression of polar invertebrates

Climate change is known to affect the distribution and composition of species, but concomitant alterations to functionally important aspects of behaviour and species-environment relations are poorly constrained. Here, we examine the ecosystem ramifications of changes in sediment-dwelling invertebrate bioturbation behaviour—a key process mediating nutrient cycling—associated with near-future environmental conditions (+ 1.5 °C, 550 ppm [pCO2]) for species from polar regions experiencing rapid rates of climate change. We find that responses to warming and acidification vary between species and lead to a reduction in intra-specific variability in behavioural trait expression that adjusts the magnitude and direction of nutrient concentrations. Our analyses also indicate that species behaviour is not predetermined, but can be dependent on local variations in environmental history that set population capacities for phenotypic plasticity. We provide evidence that certain, but subtle, aspects of inter- and intra-specific variation in behavioural trait expression, rather than the presence or proportional representation of species per se, is an important and under-appreciated determinant of benthic biogeochemical responses to climate change. Such changes in species behaviour may act as an early warning for impending ecological transitions associated with progressive climate forcing.

Inelastic behavior of diagonally reinforced coupling beams confined with steel fibers

Experimental studies were conducted to analyze the plastic rotation capacity and the effect of replacing transverse reinforcements with steel fibers in diagonal reinforced concrete coupling beams. Six specimens were planned, and the steel fiber reinforcing index and total area of transverse reinforcements were the main variables. Reverse cyclic loading tests were conducted to confirm the seismic performance of the coupling beam. The results showed that the plastic hinge rotation capacity increased and the buckling point of the diagonal reinforcing bars was delayed as the steel fiber reinforcing index increased. An analysis of 78 specimens and the results of previous studies confirmed that ductility improved when the confinement effect of the steel fiber was considered. Application of an equation for ductility requirements reflecting the confining stress of steel fiber reinforced concrete confirmed that the amount of transverse reinforcement could be reduced.

Enteric neuropathy and the vagus nerve: Therapeutic implications.

Enteric neuropathies are characterized by abnormalities of gut innervation, which includes the enteric nervous system, inducing severe gut dysmotility among other dysfunctions. Most of the gastrointestinal tract is innervated by the vagus nerve, the efferent branches of which have close interconnections with the enteric nervous system and whose afferents are distributed throughout the different layers of the digestive wall. The vagus nerve is a key element of the autonomic nervous system, involved in the stress response, at the interface of the microbiota-gut-brain axis, has anti-inflammatory and prokinetic properties, modulates intestinal permeability, and has a significant capacity of plasticity and regeneration. Targeting these properties of the vagus nerve, with vagus nerve stimulation (or non-stimulation/ pharmacological methods), could be of interest in the therapeutic management of enteric neuropathies.

Differential Regulation of Opsin Gene Expression in Response to Internal and External Stimuli.

Determining how internal and external stimuli interact to determine developmental trajectories of traits is a challenge that requires the integration of different subfields of biology. Internal stimuli, such as hormones, control developmental patterns of phenotypic changes, which might be modified by external environmental cues (e.g. plasticity). Thyroid hormone (TH) modulates the timing of opsin gene expression in developing Midas cichlid fish (Amphilophus citrinellus). Moreover, fish reared in red light accelerate this developmental timing compared to fish reared in white light. Hence, we hypothesized that plasticity caused by variation in light conditions has coopted the TH signaling pathway to induce changes in opsin gene expression. We treated Midas cichlids with TH and crossed this treatment with two light conditions, white and red. We observed that not only opsin expression responded similarly to TH and red light but also that, at high TH levels, there is limited capacity for light-induced plasticity. Transcriptomic analysis of the eye showed that genes in the TH pathway were affected by TH, but not by light treatments. Coexpression network analyses further suggested that response to light was independent of the response to TH manipulations. Taken together, our results suggest independent mechanisms mediating development and plasticity during development of opsin gene expression, and that responses to environmental stimuli may vary depending on internal stimuli. This conditional developmental response to external factors depending on internal ones (e.g. hormones) might play a fundamental role in the patterns of phenotypic divergence observed in Midas cichlids and potentially other organisms.

Ductal carcinoma in situ: Molecular and cellular basis of malignancy.

e12582 Background: The goal of our study is to improve the diagnosis and treatment of DCIS through the identification of the factors driving its invasion and metastasis. Methods: We utilized the Mouse INtraDuctal (MIND) model to investigate the mechanism(s) by which some DCIS become invasive while others remain indolent. This model closely replicates the human condition by injecting non-invasive epithelial cells from patients into mouse mammary ducts to form in situ lesions. In some cases, these cells will display invasive behavior by overcoming the natural barriers of myoepithelium. To compare these two processes, we performed single-cell (sc) RNA-sequencing analysis of 60,000 cells from the pre-transplant time-point representing 17 DCIS (11 became invasive, 6 remained non-invasive). We also performed scATAC/RNA sequencing of a DCIS with associated IDC. Results: Our analysis revealed that the proportion of endothelial cells was higher in cases that became invasive, while the proportion of plasma and T cells was higher in those that remained non-invasive (t-test; P<0.05). This finding suggested that invasive cells reprogrammed the immune microenvironment to exclude immune cells as a means of evading immune surveillance. Additionally, we performed cell-cell interaction (CCI) analysis by CellPhoneDB. This analysis revealed highly ranked CCIs in invasive cases, including luminal cell interactions with pericytes via Wnt5A-SFRP1. On the other hand, highly ranked CCIs in non-invasive cases included HR-positive luminal cell interactions with T cells via CD226-Nectin-2 and CD96-Nectin1. Notably, CD226 and CD96 are T cell receptors that enhance CD8+ T cell activity. These results support the potential role of T-cell interactions with DCIS luminal cells in preventing their invasive transition. We conducted additional analysis of sc-RNA-sequencing data using a stem cell-based gene signature algorithm called CytoTRACE. Our analysis revealed that invasive cells were enriched in cell clusters with significantly higher stem cell scores than non-invasive cells. In another analysis of a patient DCIS with associated IDC using sc-ATAC and RNA sequencing, we discovered that the open chromatin regions in the stem cell cluster were enriched for FOXA1 binding motifs. This cluster also had the highest expression of two pioneer factors (FOXA1 and GRHL2), NEAT1 (paraspeckle protein), ERBB2, 3,4, and ANKRD30A (cell surface protein). Our findings suggest that the pioneer factors FOXA1 and GRHL2 play a crucial role as transcriptional drivers of stemness. Additionally, the ANKRD30A could be used to isolate stem cell clusters to validate their self-renewal potential. Conclusions: DCIS progression is facilitated by interactions between stromal, immune, and epithelial cells, which lead to epigenetic and transcriptional changes. This results in the formation of stem-like cells that are characterized by their plasticity and invasive capacity.

Experimental investigation of dowel action in reinforcing bars using refined measurements

AbstractIn typical reinforced concrete design, reinforcement is designed to carry axial forces, but it can also resist transversal forces by dowel action. This is usually neglected for simplicity's sake in the design phase, but it can be accounted for either explicitly in mechanical models or implicitly in empirical relationships. Furthermore, there are cases where the connection between various concrete elements explicitly depends on dowel action, as for example, in connections between precast elements or between two concrete parts cast at different times. On the other side, dowel action can have a negative impact on the fatigue resistance of reinforcing bars subjected to cyclic loading, because of the local stress concentrations near interfaces due to relative movements, either in sliding or in opening of cracks not perpendicular to the bar. For the assessment of the remaining capacity of existing structures, improved models of the behavior are needed, including realistic models of the behavior of concrete, steel and their interfaces. The aim of the present paper is to provide a contribution to a better understanding of dowel action by two test series. The first series focused on the behavior of the dowel: the concrete specimens with the embedded bars were placed in a custom‐made test setup and subjected to monotonic or low stress‐level cyclic actions with a longitudinal and a transversal crack opening component, up to developing the full plastic capacity of the dowel and rupture at the peak of catenary action. The measurement system included tracking the displacement field at the surface of the concrete and the strains in the dowel by optical fibers glued on its surface. The latter measurements allow to derive the internal forces in the reinforcing bar and deformed shape of the bar as well as the contact pressure between the bar and the surrounding concrete. The results show a strong dependency on the test variables: diameter of the bar, imposed crack kinematics and angle between the bar and the crack. The second test series looked more closely at the behavior of concrete underneath the bar, in the presence of a point load introduced at various locations into concrete through a reinforcing bar. A comparison of the test results with existing models shows a general good agreement and some aspects that deserve to be improved.

Ecological plasticity, stability, and nitrogen-fixing capacity of edible bean cultivars in the Forest-Steppe of Ukraine

The purpose of this study was to investigate the influence of climatic conditions of the research years on changes in productivity and environmental plasticity and stability of edible bean cultivars. Furthermore, the study investigated the nitrogen-fixing potential of edible bean cultivars for the biologisation of agriculture. The study was conducted in the conditions of the educational and production department of the Uman National University of Horticulture during 2020-2022, using nine cultivars of edible beans. Standard methods of statistical analysis were used to study the parameters of adaptive variability. As a result of the comparative study, the characteristics of various parameters of the adaptive potential of edible bean cultivars were established by the following traits: the onset of the technical ripeness phase: Bianco and Extra Grano Violetto – 78 days. The cultivars Windsor Broad (16.42 t/ha), Bianco (13.73 t/ha), and Svitiaz (11.51 t/ha) stood out in terms of yield and adaptability in the technical ripeness phase, the cultivars Bacchus (1.92 t/ha) and Svitiaz (1.90 t/ha) – in terms of yield and adaptability in the biological ripeness phase; cultivars with high protein content in immature grain: Karmazin (12.77 g/100 g), Windsor Broad (13.51 g/100 g), Bianco (14.30 g/100 g), and Green lowland (14.43 g/100 g); cultivars with high nitrogen-fixing capacity: Ukrainian Sloboda (67.7 kg/ha), Windsor Broad (71.0 kg/ha), and Extra Grano Violetto (75.7 kg/ha). The results of the statistical analysis showed a significant influence of environmental conditions on the formation of productivity indicators of edible bean cultivars and a greater dependence on environmental conditions (CVA = 10.40-82.7%) than on the genetic component (CVG = 5.76-39.7%). The data suggest a tendency for yields to be inversely related to yield stability, with low-yielding cultivars showing stability and high-yielding cultivars showing instability. The presented findings suggest an idea of the change in the productivity parameters of edible beans under contrasting weather conditions, which makes it possible to identify cultivars with high productivity for food purposes and with a higher proportion of high-protein and energy-rich consumer products. Cultivars with increased nitrogen-fixing capacity were identified, which will help reduce the use of synthetic fertilisers

Central carbon metabolism exhibits unique characteristics during the handling of fungal patterns by monocyte-derived dendritic cells

Monocyte-derived dendritic cells (MDDCs) are key players in the defense against fungal infection because of their outstanding capacity for non-opsonic phagocytosis and phenotypic plasticity. Accordingly, MDDCs rewire metabolism to meet the energetic demands for microbial killing and biomass synthesis required to restore homeostasis. It has been commonplace considering the metabolic reprogramming a mimicry of the Warburg effect observed in tumor cells. However, this may be an oversimplification since the offshoots of glycolysis and the tricarboxylic acid (TCA) cycle are connected in central carbon metabolism. Zymosan, the external wall of Saccharomyces cerevisiae, contains β-glucan and α-mannan chains that engage the C-type lectin receptors dectin-1/2 and Toll-like receptors. This makes it an optimal fungal surrogate for experimental research. Using real-time bioenergetic assays and [U–13C]glucose labeling, central hubs connected to cytokine expression were identified. The pentose phosphate pathway (PPP) exhibited a more relevant capacity to yield ribose-5-phosphate than reducing equivalents of NADPH, as judged from the high levels of isotopologues showing 13C-labeling in the ribose moiety and the limited contribution of the oxidative arm of the PPP to the production of ROS by NADPH oxidases (NOX). The finding of 13C-label in the purine ring and in glutathione unveiled the contribution of serine-derived glycine to purine ring and glutathione synthesis. Serine synthesis also supported the TCA cycle. Zymosan exhausted NAD+ and ATP, consistent with intracellular consumption and/or extracellular export. Poly-ADP-ribosylated proteins detected in the nuclear fractions of MDDCs did not show major changes upon zymosan stimulation, which suggests its dependence on constitutive Fe(II)/2-oxoglutarate-dependent demethylation of 5-methylcytosine by TET translocases and/or demethylation of histone H3 lysine 27 by JMJD demethylases rather than on NOX activities. These results disclose a unique pattern of central carbon metabolism following fungal challenge, characterized by the leverage of glycolysis offshoots and an extensive recycling of NAD+ and poly(ADP-ribose).

Differential tractography and whole brain connectometry in primary motor area gliomas resection: A feasibility study

ObjectiveEstablish the evolution of the connectome before and after resection of motor area glioma using a comparison of connectome maps and high-definition differential tractography (DifT). MethodsDifT was done using normalized quantitative anisotropy (NQA) with DSI Studio. The quantitative analysis involved obtaining mean NQA and fractional anisotropy (FA) values for the disrupted pathways tracing the corticospinal tract (CST), and white fiber network changes over time. ResultsWe described the baseline tractography, DifT, and white matter network changes from two patients who underwent resection of an oligodendroglioma (Case 1) and an IDH mutant astrocytoma, grade 4 (Case 2). Case 1. There was a slight decrease in the diffusion signal of the compromised CST in the immediate postop. The NQA and FA values increased at the 1-year follow-up (0.18 vs. 0.32 and 0.35 vs. 0.44, respectively). Case 2. There was an important decrease in the immediate postop, followed by an increase in the follow-up. In the 1-year follow-up, the patient presented with radiation necrosis and tumor recurrence, increasing NQA from 0.18 in the preop to 0.29. Fiber network analysis: whole-brain connectome comparison demonstrated no significant changes in the immediate postop. However, in the 1-year follow up there was a notorious reorganization of the fibers in both cases, showing the decreased density of connections. ConclusionsConnectome studies and DifT constitute new potential tools to predict early reorganization changes in a patient’s networks, showing the brain plasticity capacity, and helping to establish timelines for the progression of the tumor and treatment-induced changes.

Synaptic Information Storage Capacity Measured With Information Theory.

Variation in the strength of synapses can be quantified by measuring the anatomical properties of synapses. Quantifying precision of synaptic plasticity is fundamental to understanding information storage and retrieval in neural circuits. Synapses from the same axon onto the same dendrite have a common history of coactivation, making them ideal candidates for determining the precision of synaptic plasticity based on the similarity of their physical dimensions. Here, the precision and amount of information stored in synapse dimensions were quantified with Shannon information theory, expanding prior analysis that used signal detection theory (Bartol etal., 2015). The two methods were compared using dendritic spine head volumes in the middle of the stratum radiatum of hippocampal area CA1 as well-defined measures of synaptic strength. Information theory delineated the number of distinguishable synaptic strengths based on nonoverlapping bins of dendritic spine head volumes. Shannon entropy was applied to measure synaptic information storage capacity (SISC) and resulted in a lower bound of 4.1 bits and upper bound of 4.59 bits of information based on 24 distinguishable sizes. We further compared the distribution of distinguishable sizes and a uniform distribution using Kullback-Leibler divergence and discovered that there was a nearly uniform distribution of spine head volumes across the sizes, suggesting optimal use of the distinguishable values. Thus, SISC provides a new analytical measure that can be generalized to probe synaptic strengths and capacity for plasticity in different brain regions of different species and among animals raised in different conditions or during learning. How brain diseases and disorders affect the precision of synaptic plasticity can also be probed.

Numerical method for the primary torsional capacity of arbitrary steel cross sections considering nonlinear plastic behaviour

In structural design, plastic capacities of cross sections are of great importance for evaluating the capacity of steel members. Moreover, when it comes to problems of member stability, states of partial plasticisation are of interest as well. Depending on the cross section geometry and the material law to be considered, the determination can be challenging. This particularly applies to load conditions characterised by shear stress states, as for instance in the case of primary torsion (St. Venant's torsion). Simplifications are therefore often made with regard to the cross section geometry and engineering models are applied if the plastic limit moment of primary torsion Mpl,xp is to be determined. However, numerical methods allow a precise determination of properties and stress distributions of arbitrary cross section. In the present study, corresponding finite element formulations are combined with a plasticity algorithm for torsional analysis considering effects of nonlinear isotropic hardening. The approach approximates the nonlinear material law by a multilinear curve, which is stepwise evaluated based on linear hardening formulations. It allows determining states of partial cross section plasticisation for any strain or deformation state as well as the identification of the plastic limit capacity of the cross section. Results of the implemented algorithm are presented and verified for different common steel profiles showing excellent agreement to comparative studies.