Preemptive Control Research Articles

The role of RNF149 in the pre-emptive quality control substrate ubiquitination

Protein quality control is a process in which a protein’s folding status is constantly monitored. Mislocalized proteins (MLP), are processed by the various quality control pathways, as they are often misfolded due to inappropriate cellular surroundings. Polypeptides that fail to translocate into the ER due to an inefficient signal peptide, mutations or ER stress are recognized by the pre-emptive ER associated quality control (pEQC) pathway and degraded by the 26 S proteasome. In this report we reveal the role of RNF149, a membrane bound E3 ligase in the ubiquitination of known pEQC substrates. We demonstrate its selective binding only to non-translocated proteins and its association with known pEQC components. Impairment in RNF149 function increases translocation flux into the ER and manifests in a myeloproliferative neoplasm (MPN) phenotype, a pathological condition associated with pEQC impairment. Finally, the dynamic localization of RNF149 may provide a molecular switch to regulate pEQC during ER stress.

Pre-emptive Braking Control for Stability Improvement of Autonomous Vehicles on a Curved Road Based on Vehicle-to-Everything Technology

<div>Vehicle-to-everything (V2X) technology has played an important role in improving the active safety of autonomous vehicles. In order to improve the stability of the autonomous vehicle on the curved road, this article presents a pre-emptive braking control method based on V2X technology. Instead of using the active safety system to try to stabilize the vehicle in case of danger, the pre-emptive braking action is proposed to reduce the vehicle speed in advance to a level that allows safe navigation of the turn to avoid danger. It is assumed that the friction and curvature of the curved road ahead can be obtained through V2X technology. Combined with a linear two degrees of freedom (2-DOF) bicycle model, an optimal control method is adopted to calculate the front and rear wheel steering angles to track the centerline of the curve lane. A more complex vehicle dynamics model established earlier is selected for simulation analysis to verify the proposed control method. The results show that the proposed control method can improve greatly the stability of the autonomous vehicle on the curved road.</div>

SMART Emergency Vehicle Management at Signalized Intersection using Machine Learning

Objective: Primary objective of the article is to develop a machine-learningbased pre-emptive traffic signal controller to ensure the free flow of an emergency vehicle across the signalized intersection. Method: Pre-emptive signal control system involves various functional modules such as emergency vehicle notification, traffic volume estimation, green time prediction, and signal control. The current study is focused on green time prediction based on traffic composition and volume. The study is presented in two folds; identify a suitable machine learning model to predict the green time and use the selected model to design the proposed system. The results obtained from the proposed system are compared against a non-pre-emptive controller. Findings: The Convolution Neural Network (CNN) is found to be the best suitable algorithm for green time prediction. The green time prediction module shares a pivotal role in the system as more/less green time prediction can waste the green time or block the free flow of emergency vehicles. Thus, the accuracy of green time prediction has significance in the system and CNN showed a 96% R2-score. Delay for an emergency vehicle is 86 seconds in a conventional non-pre-emptive controller and it is 8 seconds in the case of proposed system. Novelty: Green time prediction under heterogeneous traffic conditions is a challenge. Analytical models are widely used to estimate the green time as per existing research works concerned with emergency vehicle management. However, machine learning models are also in use, but deep learning models are applied rarely, and CNN is applied in current work. Keywords: Signal preemption; edge computing; machine learning; signalized intersection; emergency management

On Pre-Emptive In-Wheel Motor Control for Reducing the Longitudinal Acceleration Oscillations Caused by Road Irregularities

Road irregularities induce vertical and longitudinal vibrations of the sprung and unsprung masses, which affect vehicle comfort. While the vertical dynamics and related compensation techniques are extensively covered by the suspension control literature, the longitudinal dynamics on uneven road surfaces are less frequently addressed, and are significantly influenced by the tires and suspension systems. The relatively slow response of internal combustion engines does not allow any form of active compensation of the effect of road irregularities. However, in-wheel electric powertrains, in conjunction with pre-emptive control based on the information on the road profile ahead, have some potential for effective compensation, which, however, has not been explored yet. This paper presents a proof-of-concept nonlinear model predictive control (NMPC) implementation based on road preview, which is preliminarily assessed with a simulation model of an all-wheel drive electric vehicle with in-wheel motors, including a realistic tire model for ride comfort simulation. The major improvement brought by the proposed road preview controller is evaluated through objective performance indicators along multiple maneuvers, and is confirmed by the comparison with two benchmarking feedback controllers from the literature.

Creutzfeldt-Jakob Disease Incidence, South Korea, 2001-2019.

We found increasing trends of Creutzfeldt-Jakob disease (CJD) cases and annual incidence in South Korea during 2001–2019. We noted relatively low (5.7%) distribution of familial CJD. An unusually high percentage (≈1%) of patients were in the 30–39 age group, which should prompt a preemptive CJD control system.

The Role of the Rhomboid Superfamily in ER Protein Quality Control: From Mechanisms and Functions to Diseases.

The endoplasmic reticulum (ER) is an essential organelle in eukaryotic cells and is a major site for protein folding, modification, and lipid synthesis. Perturbations within the ER, such as protein misfolding and high demand for protein folding, lead to dysregulation of the ER protein quality control network and ER stress. Recently, the rhomboid superfamily has emerged as a critical player in ER protein quality control because it has diverse cellular functions, including ER-associated degradation (ERAD), endosome Golgi-associated degradation (EGAD), and ER preemptive quality control (ERpQC). This breadth of function both illustrates the importance of the rhomboid superfamily in health and diseases and emphasizes the necessity of understanding their mechanisms of action. Because dysregulation of rhomboid proteins has been implicated in various diseases, such as neurological disorders and cancers, they represent promising potential therapeutic drug targets. This review provides a comprehensive account of the various roles of rhomboid proteins in the context of ER protein quality control and discusses their significance in health and disease.

Neural Underpinnings of Proactive and Preemptive Adjustments of Action Control

This study aimed to trace the neural basis of proactive and preemptive adjustments of executive control and their effects on online processing of response conflict. In two EEG experiments, participants performed the flanker task with predictive cueing of conflict. The following questions were addressed: "Does conflict cueing improve performance?" We observed improved behavioral performance in the predictive condition, suggesting that participants proactively utilized the cues to prepare for the upcoming demands. "How is conflict processing affected by predictive cueing?" Conflict-related modulations of midfrontal N2 and theta power were smaller in the predictive than in the neutral condition. This suggests that proactive control suppressed the impact of incongruent flankers so that the conflict was reduced, and so was the involvement of online control. "Is proactive control implemented through preactivation of online control?" Conflict cueing increased midfrontal theta power also before target onset, suggesting preactivation of the control processes beforehand. "Do proactive and reactive control depend on common or unique processes?" Unlike the online control, the proactive control triggered a burst of theta power in the right hemisphere's dorsal and ventral lateral prefrontal cortices, connected with the midfrontal area via theta phase coherence. This indicates that the two control modes involve partially unique but coordinated neural processes. "Is preemptive control implemented through modulations of visual processing?" Predictive cueing modulated both the pretarget preparatory alpha desynchronization and the target selection-related posterior contralateral negativity (N2pc and sustained posterior contralateral negativity), in line with the hypothesis of preemptive tuning of sensory selection aimed at reducing the impact of conflicting stimuli.

Preemptive warning and control strategies for algal blooms in the downstream of Han River, China

Riverine blooms have become a challenging global environmental problem owing to strong disturbances from intensified human activities and the construction or operation of hydraulic projects. Previous studies mainly paid attention to algal blooms in the lakes and reservoirs, while less focused on the prediction and prevention of algal blooms in large rivers. As one of the highly regulated rivers in China, the downstream of Han River frequently occurred consecutive algal blooms in recent decades, was selected as the case study. Firstly, algal blooms in the downstream of Han River during 1992–2021 were investigated to find out the key environmental factors governing algal blooms. Secondly, the distribution lag model was applied to ascertain the time lag between key environmental factors and algal growth in January-April 2021. Thirdly, a random forest machine learning (RFML) model was established for prediction and early warning of river algal bloom. Finally, the threshold of controllable hydro-meteorological conditions and control strategies for the algal bloom prevention was proposed. Results reveal that: (1) The importance ranking of key environmental variables for algal bloom are antecedent air temperature, total phosphorus, flow discharge, total nitrogen, solar radiation and river turbidity; (2) The time-lag between algal growth and the key environmental drivers is the previous 1–5 days period; (3) The RFML model based on antecedent environmental variables can effectively predict the concentration of Chl-a; (4) The diatom bloom is very possible to outbreak if the 5-day sliding accumulated temperature is more than 43.13 °C and the average flow discharge is less than 780 m3/s. Our study may provide potential scientific guidance for the preemptive warning and control strategies of riverine blooms.

COMPARISON OF INTRAVENOUS DICLOFENAC SODIUM WITH OR WITHOUT PRE-EMPTIVE KETAMINE FOR POSTOPERATIVE ANALGESIA IN PATIENTS UNDERGOING TOTAL ABDOMINAL HYSTERECTOMY UNDER SPINAL ANAESTHESIA. A COMPARATIVE MULTIMODAL ANALGESIA APPROACH

BACKGROUND AND AIMS: Pre-emptive analgesia is initiated before surgery in order to prevent the establishment of central sensitization during intra-operative and early post-operative period. Multimodal analgesia relates a balanced approach to treat post-operative pain by combining multiple therapeutic agents and regional techniques. This study was conducted to evaluate the post-operative analgesic efcacy and safety of intravenous water based diclofenac sodium with or without pre-emptive intravenous ketamine in patients undergoing total abdominal hysterectomy under spinal anaesthesia. METHODS: This was a prospective, randomized, double blinded controlled comparative tertiary hospital based study. Three groups of 30 patients each, i.e., receiving diclofenac with and without pre-emptive ketamine and control group were enrolled. The time of rst analgesic request, total analgesic requirement in rst 24h, intra-operative and post-operative vitals, any side effects and complication were recorded. RESULTS: Statistically signicant differences were observed in post-operative mean VAS scores between T30m to T24h, mean time of requirement of rst dose of rescue analgesia request was longer in patients in group DK (373±9.39 min.), as compared to group NS (179.13±5.95min.) and group D (228.30±7.97min.), post-operative requirement of analgesia in rst 24h was lower in group DK (1.27±0.45) as compared to group NS (2.86±0.44) and group D (1.67±0.55), and quality of analgesia among the three groups (p=0.001). CONCLUSION: Pre-emptive use of ketamine with intravenous diclofenac sodium as a part of multimodal analgesia regimen render the patient pain-free in immediate post-operative period and minimize the demand of rescue analgesic.

Monitoring Protein Import into the Endoplasmic Reticulum in Living Cells with Proximity Labeling.

The proper trafficking of eukaryotic proteins is essential to cellular function. Genetic, environmental, and other stresses can induce protein mistargeting and, in turn, threaten cellular protein homeostasis. Current methods for measuring protein mistargeting are difficult to translate to living cells, and thus the role of cellular signaling networks in stress-dependent protein mistargeting processes, such as ER pre-emptive quality control (ER pQC), is difficult to parse. Herein, we use genetically encoded peroxidases to characterize protein import into the endoplasmic reticulum (ER). We show that the ERHRP/cytAPEX pair provides good selectivity and sensitivity for both multiplexed protein labeling and for identifying protein mistargeting, using the known ER pQC substrate transthyretin (TTR). Although ERHRP labeling induces formation of detergent-resistant TTR aggregates, this is minimized by using low ERHRP expression, without loss of labeling efficiency. cytAPEX labeling recovers TTR that is mistargeted as a consequence of Sec61 inhibition or ER stress-induced ER pQC. Furthermore, we discover that stress-free activation of the ER stress-associated transcription factor ATF6 recapitulates the TTR import deficiency of ER pQC. Hence, proximity labeling is an effective strategy for characterizing factors that influence ER protein import in living cells.

Biopolitics, control and pandemic policing in Victoria, Australia

The state of Victoria experienced the most far-reaching of Australia’s COVID-19 control strategies in 2020. While an initial lockdown resulted in a temporary abatement of reported infections, this was followed by an extensive resurgence of cases resulting in a 112-day lockdown from the end of winter through most of spring 2020. The ongoing social and economic costs of these measures are yet to be determined. However, our contribution proposes that the links between Foucauldian biopolitics and the Deleuzian society of control offer important insights into the impacts of the Victorian lockdowns on routine police work. Specifically, we argue that the evolution of pandemic policing, within a framework seeking to promote biopolitical control of Victoria’s population, unduly extended police powers and perpetuated many preexisting forms of bias and social injustice, which ultimately compromised public health. In building on the work of Arrigo et al (2020), we document the theoretical relationships between biopolitics, control and the broad idea of pandemic policing. We suggest emerging forms of preemptive control are inextricably tied to a pre-crime securitisation logic that sought to curtail the spread of COVID-19 throughout both urban and regional communities in Victoria. We frame our discussion in light of the Victorian Ombudsman’s inquiry into Operation Benessere, which involved a sudden, hard lockdown in nine high-rise public housing estates in North-West Melbourne. Our analysis of this inquiry highlights the controversies of emergency pandemic enforcement and their implications for police organisational accountability. This case study reveals that biopolitical notions of control strengthened formal police powers under a state of emergency that targeted the urban poor, while immunising police from conventional forms of public accountability. We argue that these forms of biopolitical control associated with pandemic policing are characterised by the same sorts of selectivity, bias, and lack of formal accountability evident in many recent Victorian policing initiatives.

Binary separation control in preparative gradient chromatography using iterative learning control

Purification of biopharmaceuticals has shifted toward continuous and integrated processes, in turn bringing along a need for monitoring and control to maintain a desired separation between the target pharmaceutical and any impurities it may carry. In this study, a cycle-to-cycle control of the retention volumes of two compounds in a chromatographic, ion exchange purification step was developed, allowing the process to maintain the desired retention volumes in the separation. The controller made use of a model-based, multivariate iterative learning control (ILC) algorithm that used a quadratic-criterion objective function for optimal set point control, along with feed-forward control based on direct model inversion for preemptive control of set point changes. The model was calibrated using 3 experiments, allowing for fast setup. The controller was tested by introducing three different disturbances to a sequence of otherwise identical ion exchange separation processes: a change in the salt concentration of the elution buffer, a change in set point, and a change in the pH of the elution buffer. It was capable of correcting for all disturbances within at most 3 cycles, proving its efficacy. The successful application of ILC for separation control in biopharmaceutical purification paves the way for the development of further ILC-based control strategies within the field, as well as combination with other control strategies.

Real-time data based thermal comfort prediction leading to temperature setpoint control

AbstractThe different thermal comfort indices such as Predictive Mean Vote (PMV), Standard Effective Temperature (SET), and Thermal Sensations (TS) have been used to predict occupants’ thermal comfort in a building. The advances in the machine learning approach help overcome the challenges of predicting current traditional thermal indices in a real-time environment. The different indices have different types of data samples (continuous/labelled). Therefore, while considering the machine learning technique in developing the models of the predictive thermal indices, it is essential to select the vital features, the proper learning type, the algorithm, and the evaluation method to establish the models of the predictive thermal comfort. The main focus of this paper is on the development of the ML model and the evaluation technique that helps in selecting the best model in predicting the thermal indices. This work proposes the new neighbourhood-component-analysis Bayesian-optimization-algorithm-based artificial-neural-network to develop a predictive model for the thermal indices. Here, we have proposed a regression-based model to predict PMV, SET and a classification-based model to predict 7-point TS. The statistical-testing results specify that the ANN model's performance is highly accurate and more reliable in predicting the thermal perception in a real-time environment. The performance of the selected model is validated using subjective measures. This prediction leads to the pre-emptive control of the setpoint temperature of the air-conditioning unit, hence resulting in energy efficiency and comfort.

An Air-Stable High-Nickel Cathode with Reinforced Electrochemical Performance Enabled by Convertible Amorphous Li2 CO3 Modification.

High-nickel (Ni ≥ 90%) cathodes with high specific capacity hold great potential for next-generation lithium-ion batteries (LIBs). However, their practical application is restricted by the high interfacial reactivity under continuous air erosion and electrolyte assault. Herein, a stable high-nickel cathode is rationally designed via in situ induction of a dense amorphous Li2 CO3 on the particle surface by a preemptive atmosphere control. Among the residual lithium compounds, Li2 CO3 is the most thermodynamically stable one, so a dense Li2 CO3 coating layer can serve as a physical protection layer to isolate the cathode from contact with moist air. Furthermore, amorphous Li2 CO3 can be transformed into a robust F-rich cathode electrolyte interphase (CEI) during cycling, which reinforces the cathode's interfacial stability and improves the electrochemical performance. The assembled coin cell with this modified cathode delivers a high discharge capacity of 232.4mAhg-1 with a superior initial Coulombic efficiency (CE) of 95.1%, and considerable capacity retention of 90.4% after 100 cycles. Furthermore, no slurry gelation occurs during the large-scale electrode fabrication process. This work opens a valuable perspective on the evolution of amorphous Li2 CO3 in LIBs and provides guidance on protecting unstable high-capacity cathodes for energy-storage devices.

Pre‐emptive oral clarithromycin to reduce the skin toxicity of panitumumab treatment for metastatic colorectal cancer.

79 Background: Chemotherapy with panitumumab is expected to be well tolerated and improve survival in patients with metastatic colorectal cancer (mCRC). However, skin toxicities are its most common adverse events. The aim of this trial was to evaluate the efficacy and safety of pre-emptive antibiotic treatment with clarithromycin (CAM) to prevent panitumumab skin toxicities. Methods: We conducted a phase lll, multicenter, open-label, randomized clinical trial on mCRC patients treated with pani- tumumab. Eligible patients were randomly assigned 1:1 to pre-emptive antibiotic and control groups. In the pre-emptive group, CAM administration (200 mg twice per day) continued daily through the panitumumab treatment period. The control regimen consisted of skin care only. The primary end point was the incidence of grade ≥ 2 skin toxicities during the 6-week skin treatment period. Results: Of 156 enrolled patients, 78 received pre-emptive antibiotic treatment, and 78 received reactive treatment. The number and incidence of grade ≥ 2 skin toxicities during the 6-week skin treatment period were 16 (21.3%) and 41 (54.7%) for the pre-emptive and control groups, respectively (HR, 0.32; 95% CI, 0.17–0.56). There was almost no difference in the rate of other adverse events between the two groups, but the incidence of grade ≥ 3 diarrhea in the pre-emptive group was high, at 8% vs. 1.3% in the control group. There were no treatment-related deaths. Conclusions: Prophylactic oral CAM together with relatively simple skin care was found to be effective in suppressing the development of grade ≥ 2 skin toxicities induced by panitumumab. Clinical trial information: UMIN000011485.

Preemptive admission control mechanism for strict QoS guarantee to life-saving emergency traffic in wireless LANs

The increasing usage of distributed emergency services (e.g. natural disaster or disaster caused by humans) in wireless local area networks requires the support of immediate channel access with strict quality of service (QoS) guarantee from a medium access control (MAC) protocol. The IEEE 802.11e/enhanced distributed channel access (EDCA) standard is the MAC enhancement for QoS. Unfortunately, 802.11e (EDCA) neither supports emergency traffic nor provides a strict QoS guarantee especially for a large number of users who report an emergency. To address this problem of achieving a strict QoS guarantee for emergency traffic, we previously developed and reported a multi-preemptive EDCA (MP-EDCA) protocol suitable for operating under low to medium traffic loads. However, MP-EDCA does not provide a strict QoS guarantee to life-saving emergency traffic (e.g. ambulance calls) in highly loaded networks. In this paper, we provide a solution to the problem of achieving a strict QoS guarantee to life-saving emergency traffic under high traffic loads. To this end, we propose a preemptive admission control (PAC) mechanism for MP-EDCA called PAC-MP-EDCA. The proposed PAC-MP-EDCA protects ongoing life-saving emergency traffic flows by giving high priority; thus, assures a QoS guarantee (in terms of lower packet delays) to life-saving emergency traffic when a high number of nodes require immediate channel access during emergency time. The priorities are set by carefully adjusting the short inter-frame space and slot-time in the emergency frames. The performance of PAC-MP-EDCA is evaluated by Riverbed Modeler simulation. Results obtained show that the proposed PAC-MP-EDCA achieved up to 98% lower MAC delays for life-saving emergency nodes and about 15% higher throughput than MP-EDCA under high traffic loads.

Epidemiology and infection control of carbapenem resistant Acinetobacter baumannii and Klebsiella pneumoniae at a German university hospital: a retrospective study of 5\xa0years (2015\u20132019)

BackgroundCarbapenem resistant (CR) Klebsiella pneumoniae (Kp) and Acinetobacter baumannii (Ab) are emerging multidrug resistant bacteria with very limited treatment options in case of infection. Both are well-known causes of nosocomial infections and outbreaks in healthcare facilities.MethodsA retrospective study was conducted to investigate the epidemiology of inpatients with CR Kp and CR Ab in a 1500-bed German university hospital from 2015 to 2019. We present our infection control concept including a weekly microbiologic screening for patients who shared the ward with a CR Kp or CR Ab index patient.ResultsWithin 5 years, 141 CR Kp and 60 CR Ab cases were hospitalized corresponding to 118 unique patients (74 patients with CR Kp, 39 patients with CR Ab and 5 patients with both CR Ab and CR Kp). The mean incidence was 0.045 (CR Kp) and 0.019 (CR Ab) per 100 inpatient cases, respectively. Nosocomial acquisition occurred in 53 cases (37.6%) of the CR Kp group and in 12 cases (20.0%) of the CR Ab group. Clinical infection occurred in 24 cases (17.0%) of the CR Kp group and in 21 cases (35.0%) of the CR Ab group. 14 cases (9.9%) of the CR Kp group and 29 cases (48.3%) of the CR Ab group had a history of a hospital stay abroad within 12 months prior to admission to our hospital. The weekly microbiologic screening revealed 4 CR Kp cases caused by nosocomial transmission that would have been missed without repetitive screening.ConclusionsCR Kp and CR Ab cases occurred infrequently. A history of a hospital stay abroad, particularly in the CR Ab group, warrants pre-emptive infection control measures. The weekly microbiologic screening needs further evaluation in terms of its efficiency.

Effect of Ozonated Water on Oral Mucositis and Pain Induced by Head and Neck Radiotherapy: A Cross-sectional Study

Background: Oral mucositis and local pain are the negative effects of the treatment of head and neck cancer with radiotherapy. Objectives: The study aimed to investigate the effect of ozonated water on the severity of mucositis and pain in (1) patients who were treated with ozonated water and (2) patients who were not treated with ozonated water. Methods: We randomly divided 93 patients with head and neck malignancy (aged 18 to 80) into three groups. Ozone-treated group 1 rinsed their mouth with 15 mL of ozonated water with a concentration of 20 - 50 ppm from the first session of radiotherapy for one minute before and after each session. Ozone-treated group 2 rinsed their mouth with 15 mL of ozonated water with a concentration of 20 - 50 ppm for three minutes and then swallowed it before and after each session. Ozone-treated groups 1 and 2 and the non-ozone-treated group received standard treatment if mucositis symptoms appeared in each patient. The minimum number of radiotherapy sessions was 30, and the minimum planned dose for each patient was 50 Gray. Anamnesis and the following clinical parameters were taken: the degree of mucositis, the use of corticosteroids, radiotherapy method, radiation dose, and Pain Visual Analog Scale. Multi-level and subgroup analyses were performed on the ozone-treated and non-ozone-treated levels. Results: The mean degrees of oral mucositis and pain were lower in the ozone-treated group 2 than in the ozone-treated group 1 and non-ozone-treated group (P < 0.05). The non-ozone-treated group had the highest degrees of oral mucositis and pain severity (P < 0.05). The Kruskal-Wallis H test showed that there was a statistically significant difference in the Visual Analog Scale of sessions 5, 10, 15, 20, 25, and 30 between different groups. However, there was no statistically significant difference in the Visual Analog Scale of session 1 (χ2 (2) = 1.022, P = 0.6). This study revealed that ozonated water can be used for preemptive pain control and mucositis. This finding aligned with previous studies. Also, former research proved the safety and efficacy of ozonated water in dentistry and medical uses. Conclusions: The use of ozonated water in patients with head and neck malignancy can reduce the pain severity and oral mucositis induced by radiotherapy. It seems that ozonated water can be used as a preemptive agent in patients who receive head and neck radiotherapy.

A Multichannel Allocation Strategy Based on Preemption Threshold and Preemption Probability in Cognitive Radio Networks

In traditional multichannel cognitive radio networks (CRNs), users are split into two different priorities. Because of the low priority of secondary users (SUs), SU packets’ transmissions are easily interrupted by primary users (PUs). In this paper, two control parameters, called preemption threshold H and preemption probability q, are used to regulate the preemption behavior of PU packets to improve the transmission performance of SU packets. When all channels in the system are occupied, the preemption behavior of PU packets will be adjusted according to the amount of SU packets that are transmitting in the system. If the amount is larger than H, the recently arrived PU packet either preempts a channel with probability q or leaves the system with probability 1 − q . The central controller manages the system’s channel usage right and determines a series of access behaviors of user packets. Considering the possible imperfect sensing, a discrete-time queueing model is developed with the proposed preemption control mechanism. Then we obtain some performance index expressions of PU and SU packets founded on the system’s state transition matrix and make the corresponding performance figures through numerical experiment. Finally, we construct a system utility function and determine the optimal preemption threshold and preemption probability through the seagull optimization algorithm (SOA). Experimental data show that the proposed mechanism by setting preemption threshold and preemption probability can significantly reduce SU packets’ outage rate and improve SU packets’ throughput rate.

Pre-emptive oral clarithromycin reduces the skin toxicity of panitumumab treatment for metastatic colorectal cancer.

Chemotherapy with panitumumab is expected to be well tolerated and improve survival in patients with metastatic colorectal cancer (mCRC). However, skin toxicities are its most common adverse events. The aim of this trial was to evaluate the efficacy and safety of pre-emptive antibiotic treatment with clarithromycin (CAM) to prevent panitumumab skin toxicities. We conducted a phase lll, multicenter, open-label, randomized clinical trial on mCRC patients treated with panitumumab. Eligible patients were randomly assigned 1:1 to pre-emptive antibiotic and control groups. In the pre-emptive group, CAM administration (200mg twice per day) continued daily through the panitumumab treatment period. The control regimen consisted of skin care only. The primary end point was the incidence of grade ≥ 2 skin toxicities during the 6-week skin treatment period. Of 156 enrolled patients, 78 received pre-emptive antibiotic treatment, and 78 received reactive treatment. The number and incidence of grade ≥ 2 skin toxicities during the 6-week skin treatment period were 16 (21.3%) and 41 (54.7%) for the pre-emptive and control groups, respectively (HR, 0.32; 95% CI, 0.17-0.56). There was almost no difference in the rate of other adverse events between the two groups, but the incidence of grade ≥ 3 diarrhea in the pre-emptive group was high, at 8% vs. 1.3% in the control group. There were no treatment-related deaths. Prophylactic oral CAM together with relatively simple skin care was found to be effective in suppressing the development of grade ≥ 2 skin toxicities induced by panitumumab. UMIN000011485 DATE OF REGISTRATION: Sep 1st, 2013.