Collision Observation-Based Optimization of Low-Power and Lossy IoT Network Using Reinforcement Learning

The Internet of Things(IoT)has numerous applications in every domain,e.g.,smart cities to provide intelligent services to sustainable cities.The next-generation of IoT networks is expected to be densely deployed in a resource-constrained and lossy environment.The densely deployed nodes producing radically heterogeneous traffic pattern causes congestion and collision in the network.At the medium access control(MAC)layer,mitigating channel collision is still one of the main challenges of future IoT networks.Similarly,the standardized network layer uses a ranking mechanism based on hop-counts and expected transmission counts(ETX),which often does not adapt to the dynamic and lossy environment and impact performance.The ranking mechanism also requires large control overheads to update rank information.The resource-constrained IoT devices operating in a low-power and lossy network(LLN)environment need an efficient solution to handle these problems.Reinforcement learning(RL)algorithms like Q-learning are recently utilized to solve learning problems in LLNs devices like sensors.Thus,in this paper,an RL-based optimization of dense LLN IoT devices with heavy heterogeneous traffic is devised.The proposed protocol learns the collision information from the MAC layer and makes an intelligent decision at the network layer.The proposed protocol also enhances the operation of the trickle timer algorithm.A Q-learning model is employed to adaptively learn the channel collision probability and network layer ranking states with accumulated reward function.Based on a simulation using Contiki 3.0 Cooja,the proposed intelligent scheme achieves a lower packet loss ratio,improves throughput,produces lower control overheads,and consumes less energy than other state-of-the-art mechanisms.

A Multi-Center International Survey Related to the Nutritional Support after Hematopoietic Stem Cell Transplantation Endorsed by the ASIA Pacific Blood and Marrow Transplantation (APBMT)

Background: The nutritional support after hematopoietic stem cell transplantation (HSCT) has not been well established due to the scarcity of clinical trials. To conduct international clinical trials in Asia, we performed the questionnaire survey to investigate the current standard of nutritional support after HSCT. Method: We sent the questionnaire to the physicians nominated by the Asia Pacific Blood and Marrow Transplantation (APBMT) members of each country/ region. Result: We received 15 responses from 7 different countries/regions. The target calorie amount is 1.0 - 1.3 × basal energy expenditure (BEE) in 11 institutes when partial parenteral nutrition is used. When total parenteral nutrition (TPN) is used, the target calorie amount is 1.0 - 1.3 × BEE in 9 institutes and 1.3 - 1.5 × BEE in 4 institutes. Lipid emulsion is routinely used in 12 institutes. Multivitamins and trace elements are routinely added to TPN used in most institutes. It is still uncommon to use the immunonutrition. Blood glucose levels are routinely monitored in all institutes, but the target range varies (<110 in 2 institutes, <150 in 4 institutes, and <200 in 8 institutes). Conclusions: Basic nutritional support is similar in participating institutes. However, the target glucose level varies and the use of immunonutrition is rather rare. These points can be the theme of future clinical trials.

Endoscopic diagnosis of cytomegalovirus gastritis after allogeneic hematopoietic stem cell transplantation

AIM:To clarify the endoscopic and clinical findings of cytomegalovirus(CMV) gastritis after allogeneic hematopoietic stem cell transplantation(allo-SCT).METHODS:Between 1999 and 2005,523 patients underwent allo-SCT at our hospital,and 115 of these patients with gastrointestinal symptoms underwent esophagogastroduodenoscopy.RESULTS:CMV gastritis was diagnosed pathologically in seven patients(1.3%) with the other 108 patients serving as controls.Six of the seven patients developed positive CMV antigenemia,and five complained of abdominal pain.Development of abdominal pain preceded CMV antigenemia in four of the f ive patients.Endoscopic examination showed oozing(n=2),erosion(n=6),and redness(n=5) in the seven patients with CMV gastritis,while the control patients showed oozing(n=3),erosion(n=24),and redness(n=100).Erosion and oozing were more frequently documented in patients with CMV gastritis compared with the controls,and the differences were statistically significant(P=0.0012 and 0.029,respectively).CMV inclusion bodies were documented in 12 of 14 biopsy specimens obtained from erosive lesions,while they were identif ied in 4 of 15 biopsy specimens obtained from lesions other than erosions(P=0.0025).CONCLUSION:This study suggests that erosion and oozing,as well as abdominal pain,are useful indicators in the diagnosis of CMV gastritis following allo-SCT.

Precambrian metallogeny,tectonics and correlations-Preface

The Precambrian continental nuclei in various parts of the globe preserve the records of important magmatic, metamorphic and tectonic events associated with the secular evolution of the Earth. In this thematic section of “Geoscience Frontiers”, we assemble a set of four key papers that address these topics from four key terranes: Western Australia, North China, northwestern India and East Antarctica.

会议聚焦：首届韩国乳腺癌治疗共识会议

首届韩国乳腺癌治疗共识会议专家小组审核和批准了关于局部治疗方法和诊断程序方面的新证据,根据最新的临床试验结果,支持保守治疗。这次会议澄清了限制应用最近的临床试验结果的障碍,如证据级别方面的问题,临床试验和日常临床实践存在的差异以及医疗必要性和医疗环境。根据共识会议,给出了关于乳腺癌治疗和诊断详细的决策建议以及专家投票详情。这些建议因疾病的严重程度、宿主因素、医疗必要性和医疗环境而不同。