Coexistence of WiFi and WiMAX Systems Based on PS-Request Protocols†

We introduce both the coexistence zone within the WiMAX frame structure and a PS-Request protocol for the coexistence of WiFi and WiMAX systems sharing a frequency band. Because we know that the PS-Request protocol has drawbacks, we propose a revised PS-Request protocol to improve the performance. Two PS-Request protocols are based on the time division operation (TDO) of WiFi system and WiMAX system to avoid the mutual interference, and use the vestigial power management (PwrMgt) bit within the Frame Control field of the frames transmitted by a WiFi AP. The performance of the revised PS-Request protocol is evaluated by computer simulation, and compared to those of the cases without a coexistence protocol and to the original PS-Request protocol

Metabolic Syndrome Prediction Using Machine Learning Models with Genetic and Clinical Information from a Nonobese Healthy Population

The prevalence of metabolic syndrome (MS) in the nonobese population is not low. However, the identification and risk mitigation of MS are not easy in this population. We aimed to develop an MS prediction model using genetic and clinical factors of nonobese Koreans through machine learning methods. A prediction model for MS was designed for a nonobese population using clinical and genetic polymorphism information with five machine learning algorithms, including naïve Bayes classification (NB). The analysis was performed in two stages (training and test sets). Model A was designed with only clinical information (age, sex, body mass index, smoking status, alcohol consumption status, and exercise status), and for model B, genetic information (for 10 polymorphisms) was added to model A. Of the 7,502 nonobese participants, 647 (8.6%) had MS. In the test set analysis, for the maximum sensitivity criterion, NB showed the highest sensitivity: 0.38 for model A and 0.42 for model B. The specificity of NB was 0.79 for model A and 0.80 for model B. In a comparison of the performances of models A and B by NB, model B (area under the receiver operating characteristic curve [AUC] = 0.69, clinical and genetic information input) showed better performance than model A (AUC = 0.65, clinical information only input). We designed a prediction model for MS in a nonobese population using clinical and genetic information. With this model, we might convince nonobese MS individuals to undergo health checks and adopt behaviors associated with a preventive lifestyle

Development of a Rating System for Digestive System Impairments: Korean Academy of Medical Sciences Guideline

A systematic and effective welfare system for people with digestive system impairments is required. In Korea, an objective and scientific rating guideline does not exist to judge the digestive system impairments. Whether the impairments exist or not and the degree of it need to be examined. Thus, with these considerations we need a scientific rating guideline for digestive system impairments to fit our cultural and social background. In 2007, a research team, for the development of rating impairment guidelines, was organized under the supervision of Korean Academy of Medical Sciences. The rating guidelines for digestive system impairments was classified into upper and lower gastrointestinal tracts impairments and liver impairment. We developed objective rating guidelines for the upper gastrointestinal tract, the impairment generated after surgery for the stomach, duodenum, esophagus, and for the lower gastrointestinal tract, the impairment generated after construction and surgery for colon, rectum, anus, and intestinal stomas. We tried to make the rating impairment guidelines to include science, objectivity, convenience, rationality, and actuality. We especially emphasized objectivity as the most important value. We worked to make it easy and convenient to use for both the subjects who received the impairment ratings and the doctors who will give the ratings

Congenital Atrophoderma of Pasini and Pierini

Idiopathic atrophoderma of Pasini and Pierini is a form of dermal atrophy of unknown etiology, usually affecting women during their adolescence and young adulthood. A 2-yr-old girl was presented with erythematous atrophic lesion on the right shoulder, which appeared from birth. The histologic findings were consistent with atrophoderma. This patient, to the best of our knowledge, is the first case of atrophoderma with an onset since birth

Prevalence of Otolaryngologic Diseases in South Korea: Data from the Korea National Health and Nutrition Examination Survey 2008

Objectives. The aims of this study were to evaluate the prevalence of otolaryngologic diseases in Korea. Methods. We obtained data from the 2008 Korea National Health and Nutrition Examination Surveys (KNHANES), which were cross-sectional surveys of the civilian, non-institutionalized population of South Korea (n=4,930). A field survey team that included an otolaryngologist, nurses, and interviewers moved with a mobile examination unit and performed otolaryngologic interviews and physical examinations. Results. The prevalence of subjective hearing loss, tinnitus, preauricular fistua, tympanic membrane perforation, and cholesteatoma were 11.97%, 20.27%, 2.08%, 1.60%, and 1.18%, respectively. Dizziness and vestibular dysfunction were common among Korean adults, since 23.33% of the participants reported symptoms of dizziness or imbalance, and the prevalence of vestibular dysfunction was 3.86%. The prevalence of nasal diseases was relatively high, as the prevalence of allergic rhinitis, chronic rhinosinusitis, and a deviated nasal septum were 28.01%, 7.12%, and 42.94%, respectively. Subjective dysphonia was found in 6.60% of the participants, and the prevalence of subjective dysphonia increased with age. Conclusion. This is the first nation-wide epidemiologic study to assess the prevalence of otolaryngologic diseases by both the Korean Otolaryngologic Society and the Ministry of Health and Welfare. Considering the high prevalence of otolaryngologic diseases in Korea, the results call for additional studies to better prevent and manage otolaryngologic diseases

Th17 Responses Are Not Induced in Dextran Sodium Sulfate Model of Acute Colitis

Dextran sodium sulfate (DSS) is a widely used chemical model for inflammatory bowel disease (IBD). It is thought that imbalances in the T helper (Th) cell subsets contribute to IBD. Recent studies suggest that the acute DSS-colitis model is polarized toward a Th1/Th17 profile based on RT-PCR analysis of colonic tissues. In the current study we determined whether colonic Th cells from DSS-colitis mice were skewed toward the Th17 profile. Mice were treated with 5% DSS for 7 days and colonic T cells isolated and examined for production of IFN-γ (Th1 cell), IL-4 (Th2 cell) and IL-17 (Th17 cell) by intracellular flow cytometry. We found that the percentage of colonic Th17 cells were similar to non-treated controls but the percentage of Th1 cells were elevated in DSS-colitis mice. These results suggest that in the acute DSS-colitis model the colonic Th cells exhibit a Th1 profile and not a Th17 profile

Comparison of Behçet's Disease and Recurrent Aphthous Ulcer According to Characteristics of Gastrointestinal Symptoms

Behçet's disease (BD) is a multisystemic chronic inflammatory disease. It is characterized by recurrent oral and genital ulcers, uveitis, skin lesions and other manifestations, including neurologic, vascular, joint, and gastrointestinal ulcers of variable severity. Recurrent aphthous ulcer (RAU) represents a very common, but poorly understood, mucosal disorder. If a patient of RAU without any other typical symptoms of BD has gastrointestinal symptoms, it is difficult to distinguish this RAU from true BD with gastrointestinal involvement. Because pathognomonic clinical features and tools are absent, the differential diagnosis of these two diseases relies on the characteristic clinical features and the judgement of an experienced physician. Sixty-five out of a total 960 RAU patients and forty-four of 556 BD patients with gastrointestinal symptoms between January 1996 and December 2003 participated in this study. All were evaluated with esophagogastroduodenoscopy and colonoscopy. Clinical, endoscopic and histopathologic findings were analyzed and ELISA tests were conducted to detect serum levels of ASCA and pANCA. No significant difference was found between the two groups. Differential diagnosis between RAU with gastrointestinal symptoms and BD with gastrointestinal involvement requires further prospective, large-scale study