Interaction driven phases in the honeycomb lattice from exact diagonalization

We investigate the fate of interaction driven phases in the half-filled honeycomb lattice for finite systems via exact diagonalization with nearest and next nearest neighbour interactions. We find evidence for a charge density wave phase, a Kekul\'e bond order and a sublattice charge modulated phase in agreement with previously reported mean-field phase diagrams. No clear sign of an interaction driven Chern insulator phase (Haldane phase) is found despite being predicted by the same mean-field analysis. We characterize these phases by their ground state degeneracy and by calculating charge order and bond order correlation functions.Comment: 7 pages, 6 figures, updated reference

Omega-3 Fatty Acids Improve Recovery, whereas Omega-6 Fatty Acids Worsen Outcome, after Spinal Cord Injury in the Adult Rat

Spinal cord injury (SCI) is a cause of major neurological disability, and no satisfactory treatment is currently available. Evidence suggests that polyunsaturated fatty acids (PUFAs) could target some of the pathological mechanisms that underlie damage after SCI. We examined the effects of treatment with PUFAs after lateral spinal cord hemisection in the rat. The ω-3 PUFAs α-linolenic acid and docosahexaenoic acid (DHA) injected 30 min after injury induced significantly improved locomotor performance and neuroprotection, including decreased lesion size and apoptosis and increased neuronal and oligodendrocyte survival. Evidence showing a decrease in RNA/DNA oxidation suggests that the neuroprotective effect of ω-3 PUFAs involved a significant antioxidant function. In contrast, animals treated with arachidonic acid, an ω-6 PUFA, had a significantly worse outcome than controls. We confirmed the neuroprotective effect of ω-3 PUFAs by examining the effects of DHA treatment after spinal cord compression injury. Results indicated that DHA administered 30 min after spinal cord compression not only greatly increased survival of neurons but also resulted in significantly better locomotor performance for up to 6 weeks after injury. This report shows a striking difference in efficacy between the effects of treatment with ω-3 and ω-6 PUFAs on the outcome of SCI, with ω-3 PUFAs being neuroprotective and ω-6 PUFAs having a damaging effect. Given the proven clinical safety of ω-3 PUFAs, our observations show that these PUFAs have significant therapeutic potential in SCI. In contrast, the use of preparations enriched in ω-6 PUFAs after injury could worsen outcome after SCI

Docosahexaenoic Acid Promotes Recovery of Motor Function by Neuroprotection and Neuroplasticity Mechanisms

The omega-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA), has been shown to promote recovery of motor function after spinal cord injury. This is likely to be at least partly due to neuroprotective effects of DHA. However, recent studies have shown that DHA also supports neuroplasticity after injury, such as promoting sprouting of spared corticospinal tract (CST) axons. In this chapter, we review the published studies showing that DHA promotes recovery of motor function in rodent models of spinal cord injury (SCI), and consider the available data on the underlying mechanisms. This includes effects on inflammation and on neuronal and oligodendrocyte survival at the injury site, and effects on spared CST axons and serotonergic axons. Current data support the hypothesis that DHA promotes recovery of motor function by both neuroprotection and neuroplasticity mechanisms. The significance of this, and the implications of combining DHA with rehabilitation strategies, will be discussed

Emergence of cosmic space in Tsallis modified gravity from equilibrium and non-equilibrium thermodynamic perspective

The profound connection between the law of emergence and the thermodynamic laws provides a new thermodynamic perspective on the accelerated expansion of the universe. In this paper, we explore this connection in the context of Tsallis entropy in both equilibrium and non-equilibrium perspectives. From an equilibrium perspective, we derive the law of emergence by considering Tsallis entropy as the horizon entropy from the unified first law of thermodynamics and the Clausius relation and is found to be consistent with the earlier proposals \cite{SHEYKHI2018118,Chen2022}. However, when one uses Tsallis entropy as the horizon entropy, the thermal evolution of the system becomes non-equilibrium \cite{10.1093/mnras/stab2671}, which results in the generation of additional entropy, and the first law of thermodynamics will get modified accordingly compared to its usual equilibrium version. We obtained the law of emergence from this modified form of the first law of thermodynamics. The law of emergence thus obtained have a simple form, which explains the emergence of the universe, in terms of the rate of change of the areal volume of the horizon, instead of the effective volume as in the equilibrium case. We have further shown that the law of emergence also satisfies the condition of the maximization of entropy; thus, the entropy of the universe evolves to a bounded value in the asymptotic future.Comment: 20 page

The effect of friction stir processing on mechanical, wear and corrosion characteristics of Cu-AlN-BN surface composite

This research investigates the impact of hybrid particles dispersed onto the surface of a copper matrix using Friction Stir Processing (FSP) on its microstructural, mechanical, and corrosion behavior. The hybrid particles under study consist of equal fractions of Aluminium Nitride (AlN) and Boron Nitride (BN). Microstructural characterization confirms breakdown of grain size due to dynamic recrystallization and presence of particles, along with their effective bonding to copper matrix. Attained results indicated a significant enhancement in hardness, with an increase of up to 3.9 % upon the introduction of particles onto the surface. Moreover, the tensile properties exhibit noticeable improvements in terms of ultimate tensile strength (6.39 %) and yield strength (6.12 %), albeit at the expense of reduced ductility in the copper matrix. Furthermore, the wear rate (decreases up to 22 %) and corrosion rate of the developed composites demonstrate a decreasing trend with the introduction of particles. This improvement can be attributed to the reduction in grain size during the FSP process and the formation of a nitride passive layer facilitated by the reinforced hybrid particles, thereby effectively inhibiting the corrosion rate

A snapshot of noncommunicable disease profiles and their prescription costs at ten primary healthcare facilities in the in the western half of the Cape Town Metropole

Objectives: There has been a rapid increase in the prevalence of  noncommunicable diseases globally. It is thought that this increase will have the greatest impact on developing countries, such as South Africa, where it will adversely affect quality of life and increase healthcare costs. This research was conducted to determine the disease profile and cost of treating patients at 10 facilities in the western half of the Cape Town Metropole.Design: An analytical, cross-sectional study was carried out in order to interpret the cost of the medication in relation to the patient disease profile.Setting and subjects: Data were collected from 10 facilities in the western half of the Cape Town Metropole over a threemonth period.Outcome measure: The outcome measure was the disease profile of  patients attending the facilities and the cost of prescriptions for these patients.Results: Most patient visits to the community health centres were to treat chronic diseases (82%). The disease profile of patients was as follows: 58.96% had hypertension, 19.67% diabetes, 12.14% asthma and chronic obstructive pulmonary disease, and 21.80% arthritis. It was found that 65% of patients with a chronic condition had co-morbidities. The cost ofprescriptions was significantly higher (p-value < 0.001) for chronic  conditions than for acute conditions. The number of comorbidities per patient also influenced the cost of the prescriptions.Conclusion: The results indicated that most of the adults attending public sector facilities in the western half of the Cape Town Metropole have  chronic diseases and that the cost of treating these conditions is  significantly greater than that of treating acute conditions. An integrated approach to the management of chronic diseases is important in  low-resource settings for the efficient utilisation of limited resources

1110 Improved real-time cine with the use of a 32-channel cardiac array and Karhunen-Loeve Transform filter

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.Leader-member exchange (LMX) theory proposes that leaders develop different quality relationships with those they manage and this is predictive of work performance. While LMX quality has been viewed as univalent (ranging from low to high quality), this paper proposes that it can also be bivalent in nature (i.e., coexisting positive and negative thoughts towards the relationship), which we refer to as LMX ambivalence. A survey measure of LMX ambivalence is developed, and through three validation and two main studies, it is shown to have construct, discriminant, and incremental predictive validity beyond that of LMX quality. Hypotheses concerning LMX ambivalence and task performance are tested in two main studies and show that (1) LMX ambivalence is negatively related to performance regardless of LMX quality, (2) high levels of perceived support from the organization (Study 1) or coworkers (Study 2) nullify the negative association between LMX ambivalence and performance, and (3) high LMX ambivalence leads to more negative affect and in turn lower task performance, but only when coworker support is low (Study 2). These results show the importance of viewing LMX quality not only in terms of its absolute level (low vs. high quality) but also as a bivalent construct where both positive and negative cognitions can coexist. They also demonstrate the value of social support in buffering the negative effects of LMX ambivalence. Furthermore, our findings extend a central tenet of LMX theory by implying that LMX quality varies not only within groups (i.e., LMX differentiation) but also within leader-follower dyads

Bayesian analysis of bulk viscous matter dominated universe

In our previous works, we have analyzed the evolution of bulk viscous matter dominated universe with a more general form for bulk viscous coefficient, $\zeta=\zeta_{0}+\zeta_{1}\frac{\dot{a}}{a}+\zeta_{2}\frac{\ddot{a}}{\dot{a}}$ and also carried out the dynamical system analysis. We found that the model reasonably describes the evolution of the universe if the viscous coefficient is a constant. In the present work we are contrasting this model with the standard $\Lambda$CDM model of the universe using the Bayesian method. We have shown that, even though the viscous model gives a reasonable back ground evolution of the universe, the Bayes factor of the model indicates that, it is not so superior over the $\Lambda$CDM model, but have a slight advantage over it.Comment: 15 pages, 9 figure

The human G93A-SOD1 mutation in a pre-symptomatic rat model of amyotrophic lateral sclerosis increases the vulnerability to a mild spinal cord compression

<p>Abstract</p> <p>Background</p> <p>Traumatic injuries can undermine neurological functions and act as risk factors for the development of irreversible and fatal neurodegenerative disorders like amyotrophic lateral sclerosis (ALS). In this study, we have investigated how a mutation of the superoxide dismutase 1 (SOD1) gene, linked to the development of ALS, modifies the acute response to a gentle mechanical compression of the spinal cord. In a 7-day post-injury time period, we have performed a comparative ontological analysis of the gene expression profiles of injured spinal cords obtained from pre-symptomatic rats over-expressing the G93A-SOD1 gene mutation and from wild type (WT) littermates.</p> <p>Results</p> <p>The steady post-injury functional recovery observed in WT rats was accompanied by the early activation at the epicenter of injury of several growth-promoting signals and by the down-regulation of intermediate neurofilaments and of genes involved in the regulation of ion currents at the 7 day post-injury time point. The poor functional recovery observed in G93A-SOD1 transgenic animals was accompanied by the induction of fewer pro-survival signals, by an early activation of inflammatory markers, of several pro-apoptotic genes involved in cytochrome-C release and by the persistent up-regulation of the heavy neurofilament subunits and of genes involved in membrane excitability. These molecular changes occurred along with a pronounced atrophy of spinal cord motor neurones in the G93A-SOD1 rats compared to WT littermates after compression injury.</p> <p>Conclusions</p> <p>In an experimental paradigm of mild mechanical trauma which causes no major tissue damage, the G93A-SOD1 gene mutation alters the balance between pro-apoptotic and pro-survival molecular signals in the spinal cord tissue from the pre-symptomatic rat, leading to a premature activation of molecular pathways implicated in the natural development of ALS.</p