Effects Of Reorganization Research Articles

Theoretical framework for learning through structural plasticity

A growing body of research indicates that structural plasticity mechanisms are crucial for learning and memory consolidation. Starting from a simple phenomenological model, we exploit a mean-field approach to develop a theoretical framework of learning through this kind of plasticity, capable of taking into account several features of the connectivity and pattern of activity of biological neural networks, including probability distributions of neuron firing rates, selectivity of the responses of single neurons to multiple stimuli, probabilistic connection rules, and noisy stimuli. More importantly, it describes the effects of stabilization, pruning, and reorganization of synaptic connections. This framework is used to compute the values of some relevant quantities used to characterize the learning and memory capabilities of the neuronal network in training and testing procedures as the number of training patterns and other model parameters vary. The results are then compared with those obtained through simulations with firing-rate-based neuronal network models. Published by the American Physical Society 2024

Specialty economies of scope in English hospitals: Cost Arguments for colocation

ObjectiveCurrent policy responses to COVID-19 disruption and care backlogs suggest potential changes to the location and structure of hospital healthcare supply. However, few studies investigating the cost effects of hospital reorganisation consider changes in the mix of outputs or test for the existence of economies of scope in hospital healthcare. Attempts to create dedicated hubs to address healthcare demand backlogs could have unintended adverse cost effects where these are provided outside existing hospital arrangements. To evaluate this, we investigate the existence and size of economies of scope in English hospital healthcare. DataWe use cost and activity data from the English NHS, linked to aggregated staff wage information and information taken from hospital financial statements. Cost and activity data was obtained from NHS England's Costing Publications. Wage data was extracted from the NHS's Electronic Staff Record via the NHS England Workforce Statistics Team, and published hospital financial accounts were aggregated and linked together at the organisation level. ResultsGeneral Surgery exhibited positive economies of scope when provided alongside other healthcare, as to a lesser extent did General Medicine and Obstetric/Gynaecology healthcare. There was little evidence for economies of scope in Diagnostic and Pathology services, Orthopaedics, or Emergency Care. Few (2/28) output cross-products (cost complementarities) were statistically significant, but Baumol's wider definition of scope economies demonstrates that scope economies are present in some specialties. ConclusionPolicymakers seeking to maximise the amount of healthcare provided and minimise the costs of doing so may wish to consider retaining General Surgery, General Medicine and Obstetric/Gynaecology healthcare supply alongside the provision of other clinical specialties. There is limited evidence that reconfiguring supply by centralizing other specialty groups into fewer providers would increase costs.

Reorganization of Snowfall beneath Cloud Top within the Comma Head Region of Two Extreme U.S. East Coast Winter Cyclones

Abstract This paper examines ice particle reorganization by three-dimensional horizontal kinematic flows within the comma head regions of two U.S. East Coast winter storms and the effect of reorganization on particle concentrations within snowbands in each storm. In these simplified experiments, the kinematic flows are from the initialization of the HRRR model. Ice particles falling through the comma head were started from either 9-, 8-, or 7-km altitude, spaced every 200 m, and were transported north or northwest, arriving within the north or northwest half of the primary snowband in each storm. The greatest particle concentration enhancement within each band was a factor of 2.32–3.84 for the 16–17 December 2020 storm and 1.76–2.32 for the 29–30 January 2022 storm. Trajectory analyses for particles originating at 4 km on the southeast side of the comma head beneath the dry slot showed that this region supplied particles to the south side of the band with particle enhancements of factor of 1.36–2.08 for the 16–17 December 2020 storm and 1.04–2.16 for the 29–30 January 2022 storm. Snowfall within the bands had two source regions: 1) on the north/northwestern side, from ice particles falling from the comma head, and 2) on the southeastern side, from particles forming at or below 4-km altitude and transported northwestward by low-level flow off the Atlantic. While the findings give information on the source of particles in the bands, they do not definitively determine the cause of precipitation banding since other factors, such as large-scale ascent and embedded convection, also contribute to snow growth. Significance Statement Wintertime storms along the east coast of North America can produce heavy snowfall, high winds, coastal flooding, and cold temperatures, resulting in major economic impacts within the northeast U.S. urban corridor. The heaviest snowfall typically occurs within snowbands, elongated narrow regions identifiable by high reflectivity on radar. This paper examines the potential sources of the ice particles contributing to the snowbands and how the flow fields throughout the storm can contribute to enhanced particle concentrations within the bands.

Ionic Liquids as Potential Cleaning and Restoration Agents for Cellulosic Artefacts

This study explores the efficacy of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide and 1-hexyl-3-methylimidazolium chloride as cleaning agents for aged cellulosic artifacts. A 10% v/v acetone solution of these ionic liquids (ILs) effectively removes the brownish-yellow color of aged paper in a 10 min immersion treatment. Colorimetric analysis shows a remarkable increase in lightness (L*) by up to 40% and a decrease in red/brownish tones (b*) after IL treatment. The cleaning process also deacidifies the paper, shifting the pH to neutral-slightly basic levels and enhancing its long-term stability. Optimal pH outcomes are achieved, with ionic liquid consumption values of 0.4–0.6 g/g of paper. The FTIR analysis revealed structural changes in cellulose induced by the washing step, which is mainly due to the reorganization effect imparted by the ionic liquids. Furthermore, ILs mobilized degraded compounds and acidic species, aiding in their extraction during the restoration process. Mechanical testing indicated an enhancement in the overall tensile strength and strain at break values for IL-treated papers by up to 33%. This study demonstrates the multiple benefits of alkylimidazolium ionic liquids for preserving and restoring cultural heritage artifacts made of cellulosic materials.

Mapping the effects of functional and structural network reorganization on the tau‐cognition relationship in Alzheimer’s disease

AbstractBackgroundTau pathology can spread through connectivity‐based networks, with certain regions (or epicenters) accumulating more tau than others. Such spatial vulnerabilities may be due to their unique apical position in the cortical hierarchy, which can be elucidated through ‘gradients of connectivity’ (Margulies 2016 PNAS). Prior work showed that the primary gradient of functional connectivity unveils a uni‐to‐transmodal topography of the healthy neocortex which highly correlates with a cognitive gradient of perception‐to‐abstraction. Here, we hypothesized that the gradients of functional/structural connectivity interact with tau to affect cognitive functions in Alzheimer’s disease (AD).MethodWe included 213 participants from TRIAD (103 CN Aß‐, 103 CN Aß+, and 75 CI Aß+) with diffusion‐weighted MRI, resting‐state functional MRI, 18F‐MK6240 tau‐PET, and an extensive cognitive battery. We performed non‐linear dimensionality reduction on the individual functional and structural connectomes, and extracted the first components (‘gradients’) ‐explaining most variance (G1FC and G1SC). First, we compared G1FC_or_SC between diagnostic groups. Second, we investigated the interaction effect of G1FC_or_SC*tauSUVR on cognition (across 9 cognitive domains). Last, we investigated whether the tau‐cognition relationship changed in a topography‐specific manner along the cortical hierarchy, within (equally‐sized) gradient‐derived meta‐ROIs along G1FC_or_SC. Results were compared to Braak‐derived regional associations. Analyses were adjusted for age, sex, APOE, education, and multiple comparisons.ResultWe observed reduced segregation of functional networks in AD compared to controls, with unimodal (lower‐order cognitive) and transmodal (higher‐order cognitive) regions moving closer on G1FC. This may indicate loss of network specialization in AD. Participants who had both higher tau and G1FC alterations had more cognitive impairment (Fig.1A; shown for MMSE/language). This interaction‐effect was less pronounced with G1SC (Fig.1B). Last, tau correlated with cognition in a topography‐specific progressive manner (i.e., along the transmodal‐unimodal G1FC axis and anterior‐posterior G1SC axis) (Fig.1C). Notably, tau correlated with delayed memory progressively along the posterior‐anterior G1SC axis (R2 = 0.93 in all and R2 = 0.95 in A+) and BraakI‐VI axis (R2 = 0.77 in all and R2 = 0.28 in A+).ConclusionOur work supports the contribution of connectome‐driven tau distribution on cognitive impairment in AD. Connectome gradients may provide a spatial framework to study tau spreading along the major axes of brain organization underlying specific cognitive domains.

Forest reorganisation effects on fuel moisture content can exceed changes due to climate warming in wet temperate forests.

The distributions of vegetation and fire activity are changing rapidly in response to climate warming. In many regions, climate effects on dead fuel moisture content (FMC) are expected to increase future wildfire activity. However, forest FMC is largely driven by microclimate conditions, which are moderated from open weather by vegetation canopies. As shifts in vegetation increase under climate warming, the extent to which future fire activity will be driven by climate directly or associated vegetation shifts remains unresolved. Here, we present a study aimed at quantifying the relative magnitudes of (i) direct climate warming, and (ii) vegetation change, on FMC. Field sites to evaluate these effects were established in a natural laboratory of altered forest states to mature wet temperate forest in south-eastern Australia. FMC was estimated using a process-based model and 48 years of reconstructed climate data. Canopy effects on microclimate were captured by transferring inputs from climate to microclimate using models parameterised with field observations. To evaluate the relative magnitude of climate and vegetation effects, we calculated the maximum difference in mean annual FMC across annual climate replicates and compared this to FMC differences across reorganising forest sites. Our results show vegetation effects on FMC can exceed those related to expected climate change. Changes to forest structure and composition increased (+15.7%) and decreased (-12.3%) mean annual FMC, with a larger negative effect when forest cover was completely removed (-18.5%). In contrast, the largest climate effect on FMC was -6.6% across 48-years of data. Our study demonstrates that the magnitude of vegetation effects on FMC can exceed expected climate change effects. Models of future fire activity that do not account for changing vegetation effects on microclimate are omitting a key biophysical control on FMC and therefore may not be accurately predicting future fire activity.

Elucidation of the α-Ketoamide Inhibition Mechanism: Revealing the Critical Role of the Electrostatic Reorganization Effect of Asp17 in the Active Site of the 20S Proteasome.

The 20S proteasome is an attractive drug target for the development of anticancer agents because it plays an important role in cellular protein degradation. It has a threonine residue that can act as a nucleophile to attack inhibitors with an electrophilic warhead, forming a covalent adduct. Fundamental understanding of the reaction mechanism between covalent inhibitors and the proteasome may assist the design and refinement of compounds with the desired activity. In this study, we investigated the covalent inhibition mechanism of an α-keto phenylamide inhibitor of the proteasome. We calculated the noncovalent binding free energy using the PDLD/S-LRA/β method and the reaction free energy through the empirical valence bond method (EVB). Several possible reaction pathways were explored. Subsequently, we validated the calculated activation and reaction free energies of the most plausible pathways by performing kinetic experiments. Furthermore, the effects of different ionization states of Asp17 on the activation energy at each step were also discussed. The results revealed that the ionization states of Asp17 remarkably affect the activation energies and there is an electrostatic reorganization of Asp17 during the course of the reaction. Our results demonstrate the critical electrostatic effect of Asp17 in the active site of the 20S proteasome.

Functional network connectivity patterns predicting the efficacy of repetitive transcranial magnetic stimulation in the spectrum of Alzheimer’s disease

BackgroundNeuro-navigated repetitive transcranial magnetic stimulation (rTMS) is potentially effective in enhancing cognitive performance in the spectrum of Alzheimer’s disease (AD). We explored the effect of rTMS-induced network reorganization and its predictive value for individual treatment response.MethodsSixty-two amnestic mild cognitive impairment (aMCI) and AD patients were recruited. These subjects were assigned to multimodal magnetic resonance imaging scanning before and after a 4-week stimulation. Then, we investigated the neural mechanism underlying rTMS treatment based on static functional network connectivity (sFNC) and dynamic functional network connectivity (dFNC) analyses. Finally, the support vector regression was used to predict the individual rTMS treatment response through these functional features at baseline.ResultsWe found that rTMS at the left angular gyrus significantly induced cognitive improvement in multiple cognitive domains. Participants after rTMS treatment exhibited significantly the increased sFNC between the right frontoparietal network (rFPN) and left frontoparietal network (lFPN) and decreased sFNC between posterior visual network and medial visual network. We revealed remarkable dFNC characteristics of brain connectivity, which was increased mainly in higher-order cognitive networks and decreased in primary networks or between primary networks and higher-order cognitive networks. dFNC characteristics in state 1 and state 4 could further predict individual higher memory improvement after rTMS treatment (state 1, R = 0.58; state 4, R = 0.54).ConclusionOur findings highlight that neuro-navigated rTMS could suppress primary network connections to compensate for higher-order cognitive networks. Crucially, dynamic regulation of brain networks at baseline may serve as an individualized predictor of rTMS treatment response.Relevance statementDynamic reorganization of brain networks could predict the efficacy of repetitive transcranial magnetic stimulation in the spectrum of Alzheimer’s disease.Key points• rTMS at the left angular gyrus could induce cognitive improvement.• rTMS could suppress primary network connections to compensate for higher-order networks.• Dynamic reorganization of brain networks could predict individual treatment response to rTMS.Graphical

Induction and destruction of folding motifs in cyclotides by cyclic cystine knots

Multivariate roles of cyclic cystine knots (CCK) present in cyclotides are well known. More than often this marvellous combination of disulphide linkages embedded in a macrocyclic backbone is seen to induce and stabilize otherwise unfavourable secondary structural motifs in peptides. Partial or complete reduction of the disulphide bonds leads to significant overhauling of the peptide structure and associated dynamics with disappearance of some of the CCK-stabilized local motifs. In this work, we explore structural and dynamical intricacies in two prototypical bracelet and a Möbius cyclotide, respectively cycloviolacin O1 (cyO1), cycloviolacin O2 (cyO2) and kalata B1 (kB1), either in their native (N, with CCK), partially reduced (with either one or two S-S bonds) or completely reduced (D, without CCK) forms using molecular dynamics simulations. The S-S linkage(s) primarily responsible for sustaining a given organized motif in each case is identified from the simulation of the partially reduced forms. Correlation of helix propensity, strand propensity and hydropathicity indices of the amino acids conserved across families of different bracelet/Möbius cyclotides give insight to the natural inclination of the CCK stabilized backbones to exhibit a given motif. Dihedral principal component analysis (dPCA) and normal mode analysis (NMA) help scan through the effect of structural reorganization on peptide dynamics. The relatively restricted dynamical modes in CCK-intact native peptides are replaced with large amplitude dynamical fluctuations in the reduced peptides. Concomitant structural variance is observed across the clusters in the space spanned by the dominant principal components (PCs).

Effect of Structural Reorganization of the Surface Layer in AMN-P and OPMN-P Membranes on the Transport Characteristics of the Electronanofiltration Separation of Aqueous Ammonium Chloride Solution

Effect of Structural Reorganization of the Surface Layer in AMN-P and OPMN-P Membranes on the Transport Characteristics of the Electronanofiltration Separation of Aqueous Ammonium Chloride Solution

Effect of Structural Reorganization of the Surface Layer in AMN-P and OPMN-P Membranes on the Transport Characteristics of the Electronanofiltration Separation of Aqueous Ammonium Chloride Solution

Effect of Structural Reorganization of the Surface Layer in AMN-P and OPMN-P Membranes on the Transport Characteristics of the Electronanofiltration Separation of Aqueous Ammonium Chloride Solution

The Effects of Judicial Reorganization of Companies on the cost of credit in Brazil and its social impacts

The present study aims to analyze whether the institute of judicial reorganization of companies has viability in the context of Economic Analysis of Law, taking into account its reflexes on the cost of credit in Brazil and consequently on society as a whole. The method of approach followed was empirical-dialectical, using bibliographic and legislative research. In conclusion, it was verified that the institute of judicial reorganization of companies, in the current national scenario, does not have viability in face of the theoretical framework of Economic Analysis of Law, considering that it provides short-term benefits only to those who participate directly in its process.

Phosphorus-doped nanoflower-like porous carbon with well-dispersed RuP sites embedded for enhancing hydrogenation of 4-nitrophenol

Heteroatom doping has emerged as a pivotal application in the synthesis of catalytic materials within the realm of catalysis. Herein, we present an innovative synthetic strategy for fabricating phosphorus-doped nanoflower-like porous carbon embedded with uniformly dispersed RuP sites (Ru/P-NFPC) originating from ruthenium-organic frameworks. This unique material was employed for the selective hydrogenation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The observed result reveals that Ru/P-NFPC exhibits outstanding catalytic activity, achieving a remarkable yield of 99.9 % for 4-AP within 180 s at ambient temperature. Comprehensive characterization techniques and experimental outcomes demonstrated that the incorporation of phosphorus atoms altered the electronic structure of the carbon nano-scaffold, facilitating the anchoring of RuP alloys and mitigating aggregation. Density Functional Theory (DFT) calculations validated the partial charge reorganization and electronic coupling effect in the unique Ru/P-NFPC catalysts. These analyses disclosed that phosphorus doping instigated electron transfer at the active catalyst interface, with P species acquiring additional electrons due to Ru's electron deficiency, thereby optimizing the catalytic reaction.

Thermochemical Study of the Interaction of Cytosine and Uracil with Peptides in a Buffered Saline: Complex Formation with beta-Endorphin 30-31 (Human), L-Glutathion (Reduced) and α-L-Alanyl-L-Tyrosine.

The complex formation of uracil and cytosine with glycyl-L-glutamic acid (β-endorphin 30-31), γ-L-glutamyl-L-cysteinyl-glycine (glutathione reduced), α-L-alanyl-L-tyrosine, and α-L-alanyl-α-L-alanine in a buffered saline has been studied using dissolution calorimetry. The values of the reaction constant, the change in Gibbs energy, enthalpy, and entropy were obtained. It is shown that the ratio of the enthalpy and entropy factors depends on the charge of the peptide ion, and the number of H-bond acceptors in the peptide structure. The contributions of interaction between charged groups and polar fragments, hydrogen bonding, and stacking interaction are discussed, taking into account the effect of solvent reorganization around the reactant molecules.

Vibrational Solvatochromism Study of the C-H···O Improper Hydrogen Bond.

The improper C-H···O hydrogen bond is an important weak interaction, with broad implications for protein and nucleic acid structure, molecular recognition, enzyme catalysis, and drug interaction. Despite its wide identification in crystal structures, the general existence of C-H···O hydrogen bonds remains elusive especially for natural C-H groups in bulk aqueous solutions at room temperature. Vibrational spectroscopy is a promising methodology to tackle this challenge, as formation of C-H···O hydrogen bonds usually causes shifts of the C-H stretch frequency. Yet, prior observations are inconclusive, as they are all based on a simple blue-shift in aqueous solution and cannot distinguish if it is an effect caused by solvent reorganization or a specific hydrogen-bonding interaction. In this work, we used vibrational solvatochromism as a calibration of the solvent reorganization effect and identified a specific H-bonding interaction. We performed vibrational solvatochromism study of C-H(D) of multiple alcohol molecules including the CH mode of CD3CH(OH)CD3 and the CD3 modes of CD3OH, CD3CH2OH, and CD3CH(OH)CD3 in a series of solvents. We found an abnormal blue-shift of the Raman frequency of the C-H and C-D bonds at both the Cα and Cβ positions of alcohols in water, which lies in an opposite direction to the expected trend due to vibrational solvatochromism. This experimental evidence supports that the improper C-H···O hydrogen bonds might generally exist between nonpolarized C-H and water in liquid solutions at room temperature.

Effect of Myofascial Reorganization and Classical Massage on Lower Trapezius Muscle Electromiographic Activity in Subjects with Non-Specific in Neck Pain: Randomized Clinical Trial

Effect of Myofascial Reorganization and Classical Massage on Lower Trapezius Muscle Electromiographic Activity in Subjects with Non-Specific in Neck Pain: Randomized Clinical Trial

Anionic lipids modulate little the reorganization effect of amyloid-beta peptides on membranes.

Amyloid-β peptide interactions with model lipid membranes have been studied by means of small angle neutron scattering and molecular dynamics simulations. These interactions had been indicated recently as an origin of the membrane structure reorganizations between spherical small unilamellar vesicles and planar bicelle-like structures. In present work, we investigate the influence of charge on the peptide-triggered morphological changes by introducing the anionic lipid DMPS to the underlying DMPC membrane. Changes to the membrane thickness and the overall membrane structure with and without Aβ25-35 incorporated have been investigated over a wide range of temperatures. Our results document the previously reported morphological reformations between bicelle-like structures present in gel phase and small unilamellar vesicles present in fluid phase to be independent from the charge existence in the system.

Semiclassical Theory of Multistage Nonequilibrium Electron Transfer in Macromolecular Compounds in Polar Media with Several Relaxation Timescales

Many specific features of ultrafast electron transfer (ET) reactions in macromolecular compounds can be attributed to nonequilibrium configurations of intramolecular vibrational degrees of freedom and the environment. In photoinduced ET, nonequilibrium nuclear configurations are often produced at the stage of optical excitation, but they can also be the result of electron tunneling itself, i.e., fast redistribution of charges within the macromolecule. A consistent theoretical description of ultrafast ET requires an explicit consideration of the nuclear subsystem, including its evolution between electron jumps. In this paper, the effect of the multi-timescale nuclear reorganization on ET transitions in macromolecular compounds is studied, and a general theory of ultrafast ET in non-Debye polar environments with a multi-component relaxation function is developed. Particular attention is paid to designing the multidimensional space of nonequilibrium nuclear configurations, as well as constructing the diabatic free energy surfaces for the ET states. The reorganization energies of individual ET transitions, the equilibrium energies of ET states, and the relaxation properties of the environment are used as input data for the theory. The effect of the system-environment interaction on the ET kinetics is discussed, and mechanisms for enhancing the efficiency of charge separation in macromolecular compounds are analyzed.

Thermodynamics and Kinetics of Electron Transfer of Electrode-Immobilized Small Laccase from Streptomyces coelicolor.

The thermodynamic and kinetic properties for heterogeneous electron transfer (ET) were measured for the electrode-immobilized small laccase (SLAC) from Streptomyces coelicolor subjected to different electrostatic and covalent protein-electrode linkages, using cyclic voltammetry. Once immobilized electrostatically onto a gold electrode using mixed carboxyl- and hydroxy-terminated alkane-thiolate SAMs or covalently exploiting the same SAM subjected to N-hydroxysuccinimide+1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (NHS-EDC) chemistry, the SLAC-electrode electron flow occurs through the T1 center. The E°' values (from +0.2 to +0.1 V vs. SHE at pH 7.0) are lower by more than 0.2 V compared to the protein either in solution or immobilized with different anchoring strategies using uncharged SAMs. For the present electrostatic and covalent binding, this effect can, respectively, be ascribed to the negative charge of the SAM surfaces and to deletion of the positive charge of Lys/Arg residues due to amide bond formation which both selectively stabilize the more positively charged oxidized SLAC. Observation of enthalpy/entropy compensation within the series indicates that the immobilized proteins experience different reduction-induced solvent reorganization effects. The E°' values for the covalently attached SLAC are sensitive to three acid base equilibria, with apparent pKa values of pKa1ox = 5.1, pKa1red = 7.5, pKa2ox = 8.4, pKa2red = 10.9, pKa2ox = 8.9, pKa2red = 11.3 possibly involving one residue close to the T1 center and two residues (Lys and/or Arg) along with moderate protein unfolding, respectively. Therefore, the E°' value of immobilized SLAC turns out to be particularly sensitive to the anchoring mode and medium conditions.

Causes, processes, and effects of academic reorganization at public master’s universities in the United States

ABSTRACT There is a wide-spread perception that universities reorganise their academic units frequently, although there is little beyond anecdote to support this. Similarly, the literature contains some speculation about what affects the success of such efforts, but there is almost no data to support various views. This study assesses the perceptions of academic reorganisations using survey responses from mid-level university administrators, deans and department heads. Relying on a random sample of administrators from Carnegie master’s institutions, we examine their perceptions of reorganisation success, as well as the processes and factors that influence reorganisation. Ultimately, we model dependent variables such as overall satisfaction with the process and perceptions of its benefits of reorganisation in order to explore associations between the nature of the reorganisation, the presence of planning, the role of institutional politics, and individual and institutional level control variables and these variables.