Performance analysis of a fully-connected, full-duplex CDMA ALOHA network with channel sensing and collision detection

In cases where machines having bursty data are equally likely to transmit to one another, code-division multiple-access (CDMA) ALOHA which allows for an individual "virtual channel" for each receiving station may be a better multiple-access protocol than simple ALOHA. With the use of "receiver-based code" multiple-access protocol, it is also possible for a station to listen to the channel of the intended receiver before transmission, and also abort transmission when it detects others transmitting on the same channel. This paper describes a model for a fully-connected, full duplex, and slotted CDMA ALOHA network where channel sensing and collision detection are used. The model is analyzed using a discrete time Markov chain and some numerical results are presented. For a system with a large number of users, where Markov analysis is impractical, equilibrium point analysis is used to predict the stability of the system, and estimate the throughput as well as the delay performance of the system when it is stable. Finally, a comparison is made with a simple channel sense multiple-access with collision detection (CSMA-CD) network, showing that a substantial improvement in the performance is achieved by the proposed network.published_or_final_versio

A 'Radical' Approach to Reading Development in Chinese: The Role of Semantic Radicals and Phonetic Radicals

Two studies investigating the significance of radical knowledge in Chinese reading development are reported in this paper. Study 1 examined the semantic radical knowledge of 20 Grade 1, 20 Grade 3, and 20 Grade 5 Chinese children in Hong Kong. It was found that various types of semantic radical knowledge, including the position and semantic category of semantic radicals, correlated significantly with Chinese word reading and sentence comprehension. Study 2 examined phonetic radical knowledge with another three groups of 20 Chinese children in Grades 1, 3, and 5 respectively. It was found that various measures of phonetic radical knowledge, including the function and sound value of phonetic radicals, correlated significantly with Chinese word reading. These studies found that, developmentally, the children started acquiring the knowledge of character structure, position, semantic category, and sound value of radicals from about Grade 1. However, they did not understand that the function of semantic radicals is to provide meaning cues in reading until Grade 3. The authors concluded that the radical is an important orthographic processing unit in reading development in Chinese.published_or_final_versio

Mammography screening in general practice - a pilot study

Objectives: To evaluate the acceptability, feasibility and performance of a mammography screening programme for female patients in general practice. Design: A cross sectional study. Setting: A general practice clinic and a resiona/ hospital in Hong Kong. Subjects: 500 Chinese women aged 45 years or older attending a university teaching general practice clinic on Hong Kong Island. Main outcome measures: The rates of uptake of screening, retakes, recall for further evaluation and fine needle aspiration (FNA), and participants' opinion on mammography. Results: The uptake rate of screening was 37%. Mammography was feasible for all participants, 12% had additional films and 7% required retakes. Sixteen percent were recalled for further evaluation, 4% had FNA, one had an excisional biopsy which revealed no cancer. Most women rated pain of mammography mild to moderate and did not find it embarrassing, 98% said that they would recommend it to their friends and 87% indicated that they would do it again. Conclusions: Mammography screening for Chinese women presenting to general practice was technically feasible. Most women found the experience of mammography screening acceptable. The uptake rate of mammography screening was much lower than what would be required to benefit the overall breast cancer mortality. There was also room for improvement in our retake and recall rates. We need to weigh the possible benefit of mammography screening against the stress and resources associated with additional films, retakes, recalls for further evaluation, FNA and excisional biopsy in individuals with false positive results.published_or_final_versio

Resection of T4 hepatocellular carcinomas with adjacent structures, is it justified?

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A case of laparoscopic hepatectomy for recurrent hepatocellular carcinoma

Conventional hepatectomy is an effective way to treat hepatocellular carcinoma. However, it is invasive and stressful. The use of laparoscopy in hepatectomy, while technically demanding, reduces surgical invasiveness and stressfulness but still achieves complete resection with adequate margins. Compared with conventional hepatectomy, laparoscopic hepatectomy provides a better chance and situation for further surgery in the case of recurrence of hepatocellular carcinoma. Even aged patients can successfully endure repeated hepatectomy using laparoscopy, as shown in the present report. This report presents a case of repeated laparoscopic hepatectomy treating hepatocellular carcinoma and its recurrence in an aged patient having cirrhosis, a disease causing extra difficulty for performing laparoscopic hepatectomy. The report also describes techniques of the operation and displays characteristic results of laparoscopic hepatectomy such as smaller wounds, less blood loss, less pain, less scars and adhesion, shorter postoperative hospital stay, and faster recovery. © 2010 Baishideng. All rights reserved.published_or_final_versio

MicroRNA-143 is a potential tumor suppressor targeting DNA methyltransferases 3a in colorectal cancer

Gastroenterology, 2009, v. 136 n. 5, suppl.1, p. A165, abstract no. 10692009 DDW (Digestive Disease Week) Abstract Supplement , AGA (American Gastroenterological Association) Institute Topic Forum, Oral sessions: Scientific sessions: Microrna and digestive cancers, Oral presentation no. 1069postprin

Radiofrequency ablation for controlling iatrogenic splenic injury

published_or_final_versionSpringer Open Choice, 21 Feb 201

Hepatic cancer stem cell marker granulin-epithelin precursor and β-catenin expression associate with recurrence in hepatocellular carcinoma

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Comprehensive characterization of the patient-derived xenograft and the paralleled primary hepatocellular carcinoma cell line

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