Optimal Scheduling Policies for Remote Estimation of Autoregressive Markov Processes over Time-Correlated Fading Channel

We consider the problem of transmission scheduling for the remote estimation of a discrete-time autoregressive Markov process that is driven by white Gaussian noise. A sensor observes this process, and then decides to either encode the current state of this process into a data packet and attempts to transmit it to the estimator over an unreliable wireless channel modeled as a Gilbert-Elliott channel, or does not send any update. Each transmission attempt consumes $\lambda$ units of transmission power, and the remote estimator is assumed to be linear. The channel state is revealed only via the feedback (ACK\slash NACK) of a transmission, and hence the channel state is not revealed if no transmission occurs. The goal of the scheduler is to minimize the expected value of an infinite-horizon cumulative discounted cost, in which the instantaneous cost is composed of the following two quantities: (i)~squared estimation error, (ii) transmission power. We show that this problem can equivalently be posed as a partially observable Markov decision process (POMDP), in which the scheduler maintains a belief about the current state of the channel, and makes decisions on the basis of the current value of the estimation error, and the belief state.~We then show that the optimal policy is of threshold-type, i.e. for each value of the estimation error $e$, there is a threshold b\ust(e) such that when the error is equal to $e$, then it is optimal to transmit only when the current belief state is greater than b\ust(e)

Development of a pre-operative scoring system for predicting risk of post-operative paediatric cerebellar mutism syndrome

BACKGROUND: Despite previous identification of pre-operative clinical and radiological predictors of post-operative paediatric cerebellar mutism syndrome (CMS), a unifying pre-operative risk stratification model for use during surgical consent is currently lacking. The aim of the project is to develop a simple imaging-based pre-operative risk scoring scheme to stratify patients in terms of post-operative CMS risk.METHODS: Pre-operative radiological features were recorded for a retrospectively assembled cohort of 89 posterior fossa tumour patients from two major UK treatment centers (age 2-23yrs; gender 28 M, 61 F; diagnosis: 38 pilocytic astrocytoma, 32 medulloblastoma, 12 ependymoma, 1 high grade glioma, 1 pilomyxoid astrocytoma, 1 atypical teratoid rhabdoid tumour, 1 hemangioma, 1 neurilemmoma, 2 oligodendroglioma). Twenty-six (29%) developed post-operative CMS. Based upon results from univariate analysis and C4.5 decision tree, stepwise logistic regression was used to develop the optimal model and generate risk scores.RESULTS: Univariate analysis identified five significant risk factors and C4.5 decision tree analysis identified six predictors. Variables included in the final model are MRI primary location, bilateral middle cerebellar peduncle involvement (invasion and/or compression), dentate nucleus invasion and age at imaging >12.4 years. This model has an accuracy of 88.8% (79/89). Using risk score cut-off of 203 and 238, respectively, allowed discrimination into low (38/89, predicted CMS probabilit

Optimal Scheduling of Uplink-Downlink Networked Control Systems with Energy Harvesting Sensor

In this work, we consider a wireless networked control system (WNCS) consisting of a plant, a battery-operated sensor, a controller, and an actuator. The battery in the sensor harvests energy from the environment. The sensor then uses this energy for packet transmissions. There are two types of wireless communication channels, (i) sensor--controller channel (also called uplink channel), and (ii) controller--actuator channel (also called downlink channel). The controller is \emph{half-duplex}, and this prevents it from simultaneously receiving an update from the sensor, and also transmitting a control packet to the actuator. Though frequent transmissions via uplink channel improve controller's estimate of the plant state, but this also reduces the timely control of the plant. Hence, in order to strike a balance between these two, we consider the problem of designing an optimal scheduling policy that minimizes the expected cumulative infinite horizon discounted cost, where the instantaneous cost is equal to the square of the plant state. At each time $t$, the scheduler at the sensor has to decide whether it should activate the uplink channel, or downlink. We pose this dynamic optimization problem as a Markov decision process (MDP), in which the state at time $t$ is composed of (i) the plant state $x(t)$, (ii) the age of the data packet available at the controller, denoted by $\tau(t)$, (iii) a binary variable $y(t)$ which indicates the availability of a control packet at the controller, and (iv) the energy level of the battery at the sensor $b(t)$. We show that there exists an optimal scheduling policy that exhibits a threshold structure, meaning that for each time $t$, if there is a control packet available with the controller, then the sensor activates the downlink channel in case $|x(t)|$ exceeds a threshold x\ust(\tau(t),b(t))

Octadecadienoate derivatives from Michelia champaca seed extract as potential larvicide and pupicide against Dengue vector Aedes albopictus

Abstract The present study was designed aiming at finding novel botanicals for controlling the vector population. Objective was to evaluate the larvicidal and pupicidal efficacies of crude and solvent extracts of Michelia champaca seed against the notorious dengue vector Aedes albopictus. 0.5% concentration of the crude extractive and 40 ppm concentration of ethyl acetate extractive were enough to execute 100% of larval mortality of all the instars after 72 h of exposure and the LC50 and LC90values (95% confidence level) of ethyl acetate extractive were 0.9880 ppm and 36.0491 ppm. In case of pupicidal bioassay, 100% mortality was observed at 200 ppm of ethyl acetate extract. Through TLC techniques, the bioactive compounds were isolated, which caused remarkable larval toxicity at 15 ppm concentration. Three-way factorial ANOVA analysis showed different concentrations, time intervals, and instars revealed a significant difference in larval death. FT-IR analysis revealed the presence several important functional groups. Presence of methyl 5,12-octadecadienoate and ethyl 9cis,11trans-octadecadienoate were ascertained by GC-MS analysis. The said bioactive compounds showed very low toxicity in non-target organisms such as damselfly (Ischnura sp.) and water bug (Diplonychus sp.) Thus, proclaiming the potentialities of Michelia champaca seed extracts as larvicidal and pupicidal agents against Ae. albopictus

Pd^II/Ag^I‑Catalyzed Room-Temperature Reaction of γ‑Hydroxy Lactams: Mechanism, Scope, and Antistaphylococcal Activity

The present work reports a PdII/AgI-promoted amidoalkylation reaction involving various γ-hydroxy lactams and C/O/S nucleophiles at room temperature. The dual mode of activation of both the electrophile and nucleophile by in situ generated catalytically active cationic PdII species facilitates the reaction at room temperature. Among the synthesized isoindoline derivatives, three compounds are found to be active against vancomycin and methicillin-resistant S. aureus strain with appreciable MIC values

Demographic factors associated with financial toxicity: Results from the multisite cost study.

e18362 Background: Financial toxicity (FT) is a major cause of distress for cancer patients. We have previously reported that FT was high among patients at a county hospital and a tertiary academic center. In this study, we sought to compare factors associated with FT at these institutions. Methods: Patients with clinic visits were asked to fill out an 11-item validated FT survey, the COST tool, and demographic questions from 10/2017 - 2/2018 at the county hospital and 7/2015 - 10/2018 at the academic center. We used a logistic regression model to analyze demographic factors associated with FT. Results: Mean COST score was significantly higher at the county hospital (28.7) compared to the academic center (20.4) (p &lt; 0.001). Distribution of cancer stage was similar between the institutions. Patients at the county hospital were more likely to have an annual household income (AHI) &lt; 25K (p < 0.001), and be insured by Medi-cal (p < 0.001). Patients at the academic center were more likely to be White (p < 0.001). Monthly OOP spending was more likely to be > 500 at the academic center (p &lt; 0.001). Conclusions: Overall, FT was higher at the county hospital as compared to the academic center. FT at both institutions was associated with higher OOP spending and lower AHI. However, variations in FT among other demographic factors may reflect differences in care delivery systems and patient populations. Our study demonstrates that demographic groups at risk for FT differs between institutions suggesting the factors that contribute financial toxicity are complex and variable. Thus local assessments of FT may be necessary for individual health systems to develop targeted interventions to improve FT among their patients.[Table: see text] </jats:p

Pd^II/Ag^I‑Catalyzed Room-Temperature Reaction of γ‑Hydroxy Lactams: Mechanism, Scope, and Antistaphylococcal Activity

The present work reports a Pd^II/Ag^I-promoted amidoalkylation reaction involving various γ-hydroxy lactams and C/O/S nucleophiles at room temperature. The dual mode of activation of both the electrophile and nucleophile by in situ generated catalytically active cationic Pd^II species facilitates the reaction at room temperature. Among the synthesized isoindoline derivatives, three compounds are found to be active against vancomycin and methicillin-resistant <i>S. aureus</i> strain with appreciable MIC values