919 research outputs found
The role of endoproteolytic processing in neurodegeneration
Endoproteolysis is a normal post-translational process in the eukaryotic cell that had played a role early on in protein evolution allowing protein catabolism and the generation of amino acids. Endoproteolytic cleavage regulates many crucial cellular processes including the activity of many proteins, their protein-protein interactions and the amplification of cell signals. Not surprisingly, disruption or alternation of endoproteolytic cleavage maybe the root cause of many human diseases such as Alzheimer’s disease, Huntington’s disease and prion diseases. Most neurodegenerative diseases (ND) are caused by the build-up of misfolded proteins and the promotion of aggregation events. A common event that occurs in these ND is the alteration of endoproteolytic cleavage due to genetic mutations of the associated-proteases or in the target substrate. Endoproteolytic cleavage resulting in protein truncation has significant effects on the structure and function of a protein representing a common feature of ND. In this review, we will discuss the endoproteolytic cleavage events that lead to ND, namely Alzheimer’s disease, Huntington’s disease and prion diseases
Gravity Bouncing Universe with Cosmological Parameters
In recent few years, the Gauss-Bonnet
theory of gravity has fascinated considerable researchers owing to its coupling
of trace of the stress-energy tensor with the Gauss-Bonnet term
. In this context, we focuss ourselves to study bouncing universe
with in gravity background. Some important
preliminaries are presented along with the discussion of cosmological
parameters to develop a minimal background about
theory of gravity. The exact bouncing
solutions with physical analysis are provided with the choice of two equation
of state parameters. It is shown that the results do agree with the present
values of deceleration, jerk and snap parameters. Moreover, it is concluded
that the model parameters are quite important for the validity of conservation
equation (as the matter coupled theories do not obey the usual conservation
law).Comment: 12 pages, 10 figure
Relative changes from prior reward contingencies can constrain brain correlates of outcome monitoring
It is well-known that the affective value of an environment can be relative to whether it reflects an improvement or a worsening from a previous state. A potential explanation for this phenomenon suggests that relative changes from previous reward contingencies can constrain how brain monitoring systems form predictions about future events. In support of this idea, we found that changes per se relative to previous states of learned reward contingencies modulated the Feedback-Related Negativity (FRN), a human brain potential known to index discrepancies between predictions and affective outcomes. Specifically, we observed that environments with a 50% reward probability yielded different FRN patterns according to whether they reflected an improvement or a worsening from a previous environment. Further, we also found that this pattern of results was driven mainly by variations in the amplitude of ERPs to positive outcomes. Overall, these results suggest that relative changes in reward probability from previous learned environments can constrain how neural systems of outcome monitoring formulate predictions about the likelihood of future rewards and nonrewards
Traversable wormholes in the extended teleparallel theory of gravity with matter coupling
This study explores the Gaussian and the Lorentzian distributed spherically
symmetric wormhole solutions in the gravity. The basic idea of the
Gaussian and Lorentzian noncommutative geometries emerges as the physically
acceptable and substantial notion in quantum physics. This idea of the
noncommutative geometries with both the Gaussian and Lorentzian distributions
becomes more striking when wormhole geometries in the modified theories of
gravity are discussed. Here we consider a linear model within
gravity to investigate traversable wormholes. In particular, we discuss the
possible cases for the wormhole geometries using the Gaussian and the
Lorentzian noncommutative distributions to obtain the exact shape function for
them. By incorporating the particular values of the unknown parameters
involved, we discuss different properties of the new wormhole geometries
explored here. It is noted that the involved matter violates the weak energy
condition for both the cases of the noncommutative geometries, whereas there is
a possibility for a physically viable wormhole solution. By analyzing the
equilibrium condition, it is found that the acquired solutions are stable.
Furthermore, we provide the embedded diagrams for wormhole structures under
Gaussian and Lorentzian noncommutative frameworks. Moreover, we present the
critical analysis on an anisotropic pressure under the Gaussian and the
Lorentzian distributions.Comment: 20 pages, 13 figures, submitted for publicatio
Effect of short chain fatty acids on the expression of free fatty acid receptor 2 (Ffar2), Ffar3 and early-stage adipogenesis
Adipose tissue has a major influence on insulin sensitivity. Stimulation of free fatty acid receptor 2 (FFAR2) has been proposed to influence adipocyte differentiation. We hypothesised that exposing preadipocytes to short chain fatty acids would induce earlier expression of nuclear receptors that co-ordinate adipogenesis, triglyceride accumulation and leptin secretion. 3T3-L1 preadipocytes were differentiated in the presence of 1 μM acetate, 0.1–10 μM propionate or vehicle control. In experiment 1, expression of Ffar2 and nuclear receptor mRNA was measured by quantitative PCR over 48 h following onset of differentiation. In experiment 2, extracellular leptin concentration and intracellular triglyceride content were measured at days 0, 2, 4, 6, 8 and 10 following the onset of differentiation. Control cells exhibited similar temporal dynamics of gene expression, triglyceride accumulation and leptin secretion as reported previously. We were unable to detect expression of Ffar3 mRNA at any stage of differentiation. Consistent with a lack of Ffar2 expression in the first 24 h of differentiation, acetate and propionate had no significant effect on nuclear receptor expression. Furthermore, acetate or propionate treatment did not alter leptin concentration or triglyceride content. In conclusion, we observed no significant effect of propionate or acetate on adipogenesis in 3T3-L1 cells using validated quantitative techniques
Screening of maize germplasm for Turcicum leaf blight resistance
: A study was conducted during Kharif 2012 and 2013 at Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar Campus Srinagar with the objective of screening sixty maize genotypes against Turcicum leaf blight caused by Exserohilum turcicum (Pass.) Leonard and Suggs. Field experiment was laid out in a randomized block design with three replications. In order to ensure establishment of infection, artificial inoculation of E. turcicum on test genotypes was made twice at 30 and 40 days after sowing with two different methods of inoculation (spraying on foliage of maize with spore suspension of pathogen @ 5x104 spores/ml at 30 DAS and by whorl drop inoculation of pathogen multiplies on sorghum grains at 40 DAS). Disease severity on test entries was scored at silk drying stage and studies revealed that two inbred lines, viz., NAI-112 and NAI-147, and one hybrid, viz., HQPM-1 were found resistant with pooled disease intensity of 4.12 per cent, 4.04 per cent and 4.38 per cent, respectively. Four inbred lines, viz., KDM 381 A, KDM 918 A, NAI-152 and NAI-167 were found susceptible with pooled disease intensity of 52.82 per cent, 51.02 per cent, 58.58 per cent and 61.33 per cent, respectively. The remaining genotypes were moderately resistant to moderately susceptible
Exploring Disturbance as a Force for Good in Motor Learning
Disturbance forces facilitate motor learning, but theoretical explanations for this counterintuitive phenomenon are lacking. Smooth arm movements require predictions (inference) about the force-field associated with a workspace. The Free Energy Principle (FEP) suggests that such ‘active inference’ is driven by ‘surprise’. We used these insights to create a formal model that explains why disturbance might help learning. In two experiments, participants undertook a continuous tracking task where they learned how to move their arm in different directions through a novel 3D force field. We compared baseline performance before and after exposure to the novel field to quantify learning. In Experiment 1, the exposure phases (but not the baseline measures) were delivered under three different conditions: (i) robot haptic assistance; (ii) no guidance; (iii) robot haptic disturbance. The disturbance group showed the best learning as our model predicted. Experiment 2 further tested our FEP inspired model. Assistive and/or disturbance forces were applied as a function of performance (low surprise), and compared to a random error manipulation (high surprise). The random group showed the most improvement as predicted by the model. Thus, motor learning can be conceptualised as a process of entropy reduction. Short term motor strategies (e.g. global impedance) can mitigate unexpected perturbations, but continuous movements require active inference about external force-fields in order to create accurate internal models of the external world (motor learning). Our findings reconcile research on the relationship between noise, variability, and motor learning, and show that information is the currency of motor learning
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