A Logical Model and Data Placement Strategies for MEMS Storage Devices

MEMS storage devices are new non-volatile secondary storages that have outstanding advantages over magnetic disks. MEMS storage devices, however, are much different from magnetic disks in the structure and access characteristics. They have thousands of heads called probe tips and provide the following two major access facilities: (1) flexibility: freely selecting a set of probe tips for accessing data, (2) parallelism: simultaneously reading and writing data with the set of probe tips selected. Due to these characteristics, it is nontrivial to find data placements that fully utilize the capability of MEMS storage devices. In this paper, we propose a simple logical model called the Region-Sector (RS) model that abstracts major characteristics affecting data retrieval performance, such as flexibility and parallelism, from the physical MEMS storage model. We also suggest heuristic data placement strategies based on the RS model and derive new data placements for relational data and two-dimensional spatial data by using those strategies. Experimental results show that the proposed data placements improve the data retrieval performance by up to 4.0 times for relational data and by up to 4.8 times for two-dimensional spatial data of approximately 320 Mbytes compared with those of existing data placements. Further, these improvements are expected to be more marked as the database size grows.Comment: 37 page

Cellular and Molecular Mediators of Neuroinflammation in the Pathogenesis of Parkinson’s Disease

Neuroinflammation is a host-defense mechanism associated with restoration of normal structure and function of the brain and neutralization of an insult. Increasing neuropathological and biochemical evidence from the brains of individuals with Parkinson's disease (PD) provides strong evidence for activation of neuroinflammatory pathways. Microglia, the resident innate immune cells, may play a major role in the inflammatory process of the diseased brain of patients with PD. Although microglia forms the first line of defense for the neural parenchyma, uncontrolled activation of microglia may directly affect neurons by releasing various molecular mediators such as inflammatory cytokines (tumor necrosis factor-α, interleukin [IL]-6, and IL-1β), nitric oxide, prostaglandin E2, and reactive oxygen and nitrogen species. Moreover, recent studies have reported that activated microglia phagocytose not only damaged cell debris but also intact neighboring cells. This phenomenon further supports their active participation in self-enduring neuronal damage cycles. As the relationship between PD and neuroinflammation is being studied, there is a realization that both cellular and molecular mediators are most likely assisting pathological processes leading to disease progression. Here, we discuss mediators of neuroinflammation, which are known activators released from damaged parenchyma of the brain and result in neuronal degeneration in patients with PD

Advances in Neuroprotective Ingredients of Medicinal Herbs by Using Cellular and Animal Models of Parkinson’s Disease

Parkinson’s disease (PD) is a multifactorial disorder, which is neuropathologically identified by age-dependent neurodegeneration of dopaminergic neurons in the substantia nigra. Development of symptomatic treatments has been partly successful for PD research, but there remain a number of inadequacies in therapeutic strategies for the disease. The pathogenesis of PD remains intricate, and the present anti-PD treatments appears to be clinically insufficient. Comprehensive research on discovery of novel drug candidates has demonstrated that natural products, such as medicinal herbs, plant extracts, and their secondary metabolites, have great potential as therapeutics with neuroprotective activity in PD. Recent preclinical studies suggest that a number of herbal medicines and their bioactive ingredients can be developed into optimum pharmaceuticals for treating PD. In many countries, traditional herbal medicines are used to prevent or treat neurodegenerative disorders, and some have been developed as nutraceuticals or functional foods. Here we focus on recent advances of the evidence-linked neuroprotective activity of bioactive ingredients of herbal origin in cellular and animal models of PD research

Dissection Manual for Open Rhinoseptoplasty in a Silicone Nose Model

Open rhinoseptoplasty has been widely performed in the field of otorhinolaryngology. However, from the perspective of beginners, rhinoseptoplasty is a hard-to-learn surgery that involves a relatively steep learning curve. Therefore, practical guidance is essential to enhance the skills needed for excellent surgical outcomes. Here, we provide a step-wise dissection manual using a commercialized silicone nose model designed for rhinoseptoplasty. The contents include general approaches with regard to transcolumellar inverted V incision, flap elevation, osteotomy, septoplasty, modification of the lower lateral cartilage for tip surgery, and dorsal augmentation using silicone implants. In addition, we introduce novel techniques such as dorsal augmentation using a ready-made mold with tissue glue applied to diced cartilage and polycaprolactone mesh for rhinoseptoplasty. The present study also provides photos of individual surgical procedures using a silicone nose model for actual guidance. The authors expect that this manual will help beginning rhinoseptoplasty surgeons improve their confidence

The First Case of Catheter-related Bloodstream Infection Caused by Nocardia farcinica

Nocardia farcinica is an emerging pathogen in immunocompromised hosts. Even though several species of Nocardia have been reported as causative pathogens of catheter-related blood stream infections (CRBSI), CRBSI caused by N. farcinica has not been reported. A 70-yr-old man with a tunneled central venous catheter (CVC) for home parenteral nutrition was admitted with fever for two days. Norcardia species was isolated from the blood through CVC and peripheral bloods and identified to N. farcinica by 16S rRNA and rpoB gene sequence analyses. This report emphasizes the rapid and correct identification of causative agents in infectious diseases in the selection of antimicrobial agents and the consideration of catheter removal

Clinical Features of Probable Cluster Headache: A Prospective, Cross-Sectional Multicenter Study

Background: Epidemiological data of probable cluster headaches (CH) are scarce in the relevant literature. Here, we sought to assess the prevalence and clinical characteristics of probable CH in comparison with definite CH.Methods: Data used in this study were obtained from the Korean Cluster Headache Registry (KCHR), a prospective, cross-sectional, multicenter headache registry that collected data from consecutive patients diagnosed with CH.Results: In total, 159 patients were enrolled in this study; 20 (12.6%) were diagnosed with probable CH. The most common unfulfilled criterion in patients with probable CH was the duration of attack, which was found in 40% of patients with probable CH. Among clinical characteristics, the number of autonomic symptoms tended to be lower in probable CH than in definite CH (1.7 ± 1.2 vs. 2.4 ± 1.5, p = 0.051) and conjunctival injection and lacrimation showed an increased odds ratio (OR) [OR = 3.03; 95% confidence interval (CI): 1.03–8.33] in definite CH. The groups did not differ with regard to baseline demographic characteristics, disability, impact on life, or treatment response.Conclusions: Probable CH is relatively common among CH disorders, with a clinical impact similar to that of definite CH

Analysis of Methicillin Resistance among Staphylococcus aureus Blood Isolates in an Emergency Department

The increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) has become of great concern in both hospital and community settings. To evaluate the prevalence and risk factors for methicillin resistance among Staphylococcus aureus, blood isolates in our Emergency Department (ED) were collected. All patients with S. aureus bacteremia (SAB) who presented to the ED from January 2000 to August 2005 were included, and a retrospective study was performed. A total of 231 patients with SAB were enrolled (median age, 59 yr; M:F, 125:106). Among these patients, methicillin-resistant strains accounted for 27.3% (63 patients). Catheter-related infection was the most frequent primary site of SAB (39.0%), followed by skin and soft tissue infection (16.5%). In multivariate analysis, recent surgery (OR, 3.41; 95% CI, 1.48-7.85), recent hospitalization (2.17; 1.06-4.62), and older age (≥61 yr) (2.39; 1.25-4.57) were independently associated with the acquisition of methicillin-resistant strains. When antimicrobial therapy is considered for the treatment of a patient with suspected SAB, clinicians should consider obtaining cultures and modifying empirical therapy to provide MRSA coverage for patients with risk factors: older age, recent hospitalization, and recent surgery

Catheter-associated bacteremia by Mycobacterium senegalense in Korea

BACKGROUND: Rapidly growing mycobacteria is recognized as one of the causative agents of catheter-related infections, especially in immunocompromised hosts. To date, however, Mycobacterium senegalense, which was known as the principal pathogen of bovine farcy, has not been reported in human infection. CASE PRESENTATION: We describe the first case of human infection by M. senegalense, which has caused catheter-related bloodstream infection in a cancer patient in Korea. The microorganism was identified by the 16S rRNA gene, rpoB, and 16S-23S rRNA gene internal transcribed spacer (ITS) sequence analyses. CONCLUSION: Our first report of catheter-associated bacteremia caused by M. senegalense suggests the zoonotic nature of this species and indicates the expansion of mycobacterial species relating to human infection. M. senegalense should be considered as one of the causes of human infections in the clinical practice