635 research outputs found
The effects of an individual, multistep intervention on adherence to treatment in hemodialysis patients
Purpose: The present study was conducted to investigate the effect of individual, multistep intervention on adherence to treatment in hemodialysis patients referred to a hemodialysis center in Shahrekord, Iran. Method: In this interventional study, hemodialysis patients referring the center of the study were randomly assigned into two control and intervention groups (each 33). The control group received routine treatment, recommended dietary and fluid restrictions. The intervention group participated in eight individual interventional sessions accompanied routine treatment. At the beginning and the end of the study, routine laboratory tests and end-stage renal disease-adherence questionnaire were filled out for patients in both groups. The data were analyzed using Mann-Whitney and Wilcoxon tests. Results: At the end of the study, the two groups showed a significant difference in all domains of adherence except adherence to diet and adherence was better in the intervention group (p < 0.05). In demographic characteristic, only age indicated a positive correlation with adherence to dialysis program (p = 0.04, r = 0.254). After intervention, serum phosphorus decreased significantly in the intervention group (p < 0.05). Conclusions: Adherence to treatment is one of the major problems in hemodialysis patients; however, comprehensive interventions are required in view of individual condition. ▸ Implications for Rehabilitation • Adherence to treatment means that all patients behaviors (diet, fluids and drugs intake) should be in line with the recommendations given by healthcare professionals. • There is evidence on the association between adherence to treatment and decreased risk of hospitalization in dialysis patients. • Individual structured programs are most likely to be successful in encouraging adherence to treatment. © 2015 Informa UK Ltd. All rights reserved
A unified uncertainty-aware exploration: Combining epistemic and aleatory uncertainty
Exploration is a significant challenge in practical reinforcement learning
(RL), and uncertainty-aware exploration that incorporates the quantification of
epistemic and aleatory uncertainty has been recognized as an effective
exploration strategy. However, capturing the combined effect of aleatory and
epistemic uncertainty for decision-making is difficult. Existing works estimate
aleatory and epistemic uncertainty separately and consider the composite
uncertainty as an additive combination of the two. Nevertheless, the additive
formulation leads to excessive risk-taking behavior, causing instability. In
this paper, we propose an algorithm that clarifies the theoretical connection
between aleatory and epistemic uncertainty, unifies aleatory and epistemic
uncertainty estimation, and quantifies the combined effect of both
uncertainties for a risk-sensitive exploration. Our method builds on a novel
extension of distributional RL that estimates a parameterized return
distribution whose parameters are random variables encoding epistemic
uncertainty. Experimental results on tasks with exploration and risk challenges
show that our method outperforms alternative approaches.Comment: Accepted by ICASSP202
A Robust Quantile Huber Loss With Interpretable Parameter Adjustment In Distributional Reinforcement Learning
Distributional Reinforcement Learning (RL) estimates return distribution
mainly by learning quantile values via minimizing the quantile Huber loss
function, entailing a threshold parameter often selected heuristically or via
hyperparameter search, which may not generalize well and can be suboptimal.
This paper introduces a generalized quantile Huber loss function derived from
Wasserstein distance (WD) calculation between Gaussian distributions, capturing
noise in predicted (current) and target (Bellman-updated) quantile values.
Compared to the classical quantile Huber loss, this innovative loss function
enhances robustness against outliers. Notably, the classical Huber loss
function can be seen as an approximation of our proposed loss, enabling
parameter adjustment by approximating the amount of noise in the data during
the learning process. Empirical tests on Atari games, a common application in
distributional RL, and a recent hedging strategy using distributional RL,
validate the effectiveness of our proposed loss function and its potential for
parameter adjustments in distributional RL. The implementation of the proposed
loss function is available here.Comment: 6 pages, 1 figure, to be published in ICASSP 202
RAPD analysis of Sclerotium rolfsii isolates causing collar rot of eggplant and tomato
Eight isolates of Sclerotium rolfsii from four strategically geographical sites of Bangladesh were characterized and their cultural properties like average linear mycelial growth, colony colour, colony consistency, growth pattern and sclerotia formation were studied. Isolates varied in mycelial growth and other growth characteristics and were grouped into three. The highest linear growth was displayed by S8. DNA concentration of eight isolates varied from 1150-7200 ng/?l. DNA fingerprinting by RAPD prompted the grouping of isolates. Selected 3 primers generated 20 bands with size ranging from 100-1500 bp. Out of the 20 bands, 9 bands (45%) were polymorphic and 11 bands (55%) were monomorphic among the eight isolates of Sclerotium rolfsii. The co-efficient of gene differentiation (Gst) was 1.000 reflecting the existence of high level of genetic variations among the 8 isolates. The lowest genetic distance and highest inter isolate similarity was found in S1 and S2 which would be homogeneous. The highest genetic distance and lowest inter isolate similarity found in S3, S7 and S3, S8 pair which would be most divergent isolates. The cluster analysis also revealed that S3, S7 and S8 belong to different clusters. All five varieties of eggplant and tomatoes were graded as susceptible when inoculated with eight isolates. Plant mortality 93.33% was recorded in S4, S6 and in S8. Considering the isolate factor the most virulent isolate would be S8 whereas the less virulent isolate would be S2 and S7. Host plant of S8 was tomato collected from Thakurgaon. S2 and S7 were collected from BAU farm and Dinajpur and host plants were lentil and tomato respectively. It is evident that Sclerotium rolfsii from Thakurgaon on host tomato is more virulent.Int. J. Agril. Res. Innov. & Tech. 6 (1): 47-57, June, 201
Simulation of Traffic Flow Model with Traffic Controller Boundary
This paper considers a fluid dynamic traffic flow model appended with a closure linear velocity-density relationship which provides a first order hyperbolic partial differential equation (PDE) and is treated as an initial boundary value problem (IBVP). We consider the boundary value in such a way that one side of highway treat like there is a traffic controller at that point. We present the analytic solution of the traffic flow model as a Cauchy problem. A numerical simulation of the traffic flow model (IBVP) is performed based on a finite difference scheme for the model with two sided boundary conditions and a suitable numerical scheme for this is the Lax-Friedrichs scheme. Solution figure from our scheme indicates a desired result that amplitude and frequency of cars density and velocity reduces as time grows. Also at traffic controller point, velocity and density values change as desired manner. In further, we also want to introduce anisotropic behavior of cars(to get more realistic picture) which has not been considered here.
Doi: 10.12777/ijse.5.1.25-30
[How to cite this article: Sultana, N., Parvin, M. , Sarker, R., Andallah, L.S. (2013). Simulation of Traffic Flow Model with Traffic Controller Boundary. International Journal of Science and Engineering, 5(1),25-30. Doi: 10.12777/ijse.5.1.25-30
Arabidopsis ITPK1 and ITPK2 Have an Evolutionarily Conserved Phytic Acid Kinase Activity
Diphospho-myo-inositol polyphosphates, also termed inositol pyrophosphates, are molecular messengers containing at least one high-energy phosphoanhydride bond and regulate a wide range of cellular processes in eukaryotes. While inositol pyrophosphates InsP7 and InsP8 are present in different plant species, both the identity of enzymes responsible for InsP7 synthesis and the isomer identity of plant InsP7 remain unknown. This study demonstrates that Arabidopsis ITPK1 and ITPK2 catalyze the phosphorylation of phytic acid (InsP6) to the symmetric InsP7 isomer 5-InsP7 and that the InsP6 kinase activity of ITPK enzymes is evolutionarily conserved from humans to plants. We also show by 31P nuclear magnetic resonance that plant InsP7 is structurally identical to the in vitro InsP6 kinase products of ITPK1 and ITPK2. Our findings lay the biochemical and genetic basis for uncovering physiological processes regulated by 5-InsP7 in plants
PIP3-Independent Activation of TorC2 and PKB at the Cell's Leading Edge Mediates Chemotaxis
SummaryBackgroundStudies show that high phosphotidylinositol 3,4,5-trisphosphate (PIP3) promotes cytoskeletal rearrangements and alters cell motility and chemotaxis, possibly through activation of protein kinase Bs (PKBs). However, chemotaxis can still occur in the absence of PIP3, and the identities of the PIP3-independent pathways remain unknown.ResultsHere, we outline a PIP3-independent pathway linking temporal and spatial activation of PKBs by Tor complex 2 (TorC2) to the chemotactic response. Within seconds of stimulating Dictyostelium cells with chemoattractant, two PKB homologs, PKBA and PKBR1, mediate transient phosphorylation of at least eight proteins, including Talin, PI4P 5-kinase, two Ras GEFs, and a RhoGap. Surprisingly, all of the substrates are phosphorylated with normal kinetics in cells lacking PI 3-kinase activity. Cells deficient in TorC2 or PKB activity show reduced phosphorylation of the endogenous substrates and are impaired in chemotaxis. The PKBs are activated through phosphorylation of their hydrophobic motifs via TorC2 and subsequent phosphorylation of their activation loops. These chemoattractant-inducible events are restricted to the cell's leading edge even in the absence of PIP3. Activation of TorC2 depends on heterotrimeric G protein function and intermediate G proteins, including Ras GTPases.ConclusionsThe data lead to a model where cytosolic TorC2, encountering locally activated small G protein(s) at the leading edge of the cell, becomes activated and phosphorylates PKBs. These in turn phosphorylate a series of signaling and cytoskeletal proteins, thereby regulating directed migration
A trust-based authentication framework for security of WPAN using network slicing
New technologies bring along many challenges including security and privacy. Wireless personal area networks (WPANs) are characterized by limited energy resources and computing power that calls for lightweight security mechanisms in these networks as a mandatory requirement. In this paper, a lightweight trust-based framework for node authentication in WPAN is proposed. Our main objective is to minimise the effort in distinguishing valid requests of trustworthy nodes from invalid requests of malicious nodes that can result in network compromises. We achieve this through network slicing which divides the network into virtually primary and secondary networks. The proposed framework has three-fold benefits. First, it authenticates nodes’ requests based on a novel method of trust value calculation. Second, the framework maintains energy efficiency while authenticating nodes’ requests to access WPAN resources. Finally, the framework provides a solution for biasing problem that can arise due to unexpected behaviour of malicious users in WPANs. The framework efficacy is illustrated on a case study to shown how it can accurately capture trust relations among nodes while preventing malicious behavior
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