Early Warning Systems in the Republic of Korea: Experiences, Lessons, and Future Steps

This paper examines the cases of the Early Warning System (EWS) in the Republic of Korea, which was introduced in the wake of 1997/98 Asian financial crisis in a policy effort to prevent its recurrence. The EWS in the Republic of Korea was expanded into a national system in 2005 incorporating the finance, real estate, commodities, and labor sectors. This paper provides the descriptions of each EWS sector and documents several episodes of their policy contributions. The past experiences suggest that quantitative models tend to have difficulty predicting a crisis due to the changing nature of crises. Hence, it is desirable that quantitative models are supplemented by qualitative analysis reinforcing EWSs with various methodologies. To improve economic surveillance and message delivery to guide proper policy actions, the independence of surveillance unit should be maintained and the scope of monitoring should be expanded to incorporate regions and markets other than domestic ones given the growing influences of the external sector on the domestic economy through trade and financial linkages.EWS; crisis; surveillance; monitoring; quantitative model; qualitative analysis

Image-guided transcranial focused ultrasound stimulates human primary somatosensory cortex

Focused ultrasound (FUS) has recently been investigated as a new mode of non-invasive brain stimulation, which offers exquisite spatial resolution and depth control. We report on the elicitation of explicit somatosensory sensations as well as accompanying evoked electroencephalographic (EEG) potentials induced by FUS stimulation of the human somatosensory cortex. As guided by individual-specific neuroimage data, FUS was transcranially delivered to the hand somatosensory cortex among healthy volunteers. The sonication elicited transient tactile sensations on the hand area contralateral to the sonicated hemisphere, with anatomical specificity of up to a finger, while EEG recordings revealed the elicitation of sonication-specific evoked potentials. Retrospective numerical simulation of the acoustic propagation through the skull showed that a threshold of acoustic intensity may exist for successful cortical stimulation. The neurological and neuroradiological assessment before and after the sonication, along with strict safety considerations through the individual-specific estimation of effective acoustic intensity in situ and thermal effects, showed promising initial safety profile; however, equal/more rigorous precautionary procedures are advised for future studies. The transient and localized stimulation of the brain using image-guided transcranial FUS may serve as a novel tool for the non-invasive assessment and modification of region-specific brain functionopen43

Hierarchical Multiscale Hyperporous Block Copolymer Membranes via Tunable Dual-Phase Separation

The rational design and realization of revolutionary porous structures have been long-standing challenges in membrane science. We demonstrate a new class of amphiphilic polystyrene-block-poly(4-vinylpyridine) block copolymer (BCP)-based porous membranes featuring hierarchical multiscale hyperporous structures. The introduction of surface energy-modifying agents and the control of major phase separation parameters (such as nonsolvent polarity and solvent drying time) enable tunable dual-phase separation of BCPs, eventually leading to macro/nanoscale porous structures and chemical functionalities far beyond those accessible with conventional approaches. Application of this BCP membrane to a lithium-ion battery separator affords exceptional improvement in electrochemical performance. The dual-phase separation-driven macro/nanopore construction strategy, owing to its simplicity and tunability, is expected to be readily applicable to a rich variety of membrane fields including molecular separation, water purification, and energy-related devices.clos

A review of technologies for in-situ sulfide control in anaerobic digestion

The generation of toxic, malodorous, and corrosive hydrogen sulfide (H2S), which can cause serious hygiene and health problems and damage biogas plants, is inevitable in anaerobic digestion (AD) of organic waste. H2S is directly toxic to different microorganisms involved in AD, and sulfidogenesis competitively inhibits methanogenesis. Many technologies for ex-situ and in-situ sulfide removal have been developed for biogas cleaning. In-situ technologies that control sulfide within digesters do not require separate facilities and thus are more convenient and economical than ex-situ technologies. However, in-situ sulfide control during AD is directly affected by digester operating conditions and environmental factors, complicating its effective operation and leads to suboptimal performance. This paper reviews the principles, advantages, and disadvantages of different in-situ sulfide control technologies, from conventional to state-of-the-art. Although conventional technologies are technically simple and effective, their large-scale application has practical limitations related to high energy and chemical consumption and the need for sophisticated operation of digesters. Recently, several advanced technologies with promising potential have been developed to overcome these limitations, although there is still a long way to go for their practical application. In addition to better performance, the advanced technologies provide attractive possibilities to improve the economic feasibility for large-scale application by regenerating and recycling valuable materials and/or recovering elemental sulfur (S0). Sulfide control is critical not only for biogas cleaning but also for stable digester operation, and it is receiving increasing attention as the importance of AD as an alternative energy source is growing. Given the increasing demand for more sustainable biogas production and upgrading, more research is needed to evaluate and improve the practical applicability of the advanced in-situ sulfide control technologies in anaerobic digester environments, particularly at large scale. This review also discusses the key challenges for their practical application and suggests future research directions

Fabrication of highly ordered silicon pin-in-a-hole nanostructures via chemical etching of nanopatterned polymer masks

We present a new technique to fabricate a highly ordered silicon pin-in-a-hole structure, in which each silicon nanowire is pinned in a hole, by combining polymer sphere arrays induced by Rayleigh instability with chemical etching process. With this process, we were able to create the novel structures that are periodic over very large areas (3 x 3 cm(2)), where the length of silicon nanowires can be varied by tuning the etching time. A silicon pin-in-a-hole structure was used as the template for preparing polymer nanotubes. And also these structures exhibited a superior anti-reflection property showing specular reflectance of about 0.2%, nearly three orders of magnitude lower than that of a planar silicon wafer.close7

Inverse Magnus effect on a rotating sphere: when and why

In some specific conditions, a flying spinning ball deflects in a direction opposite to that predicted by the Magnus effect, which is known as the inverse Magnus effect. To elucidate when and why this effect occurs, we measure the variations of the drag and lift forces on a rotating sphere and the corresponding flow field with the spin ratio (the ratio of the rotational velocity to the translational one). This counterintuitive phenomenon occurs because the boundary layer flow moving against the surface of a rotating sphere undergoes a transition to turbulence, whereas that moving with the rotating surface remains laminar. The turbulence energizes the flow and thus the main separation occurs farther downstream, inducing faster flow velocity there and generating negative lift force. Empirical formulae are derived to predict the location where the flow separates as a function of the Reynolds number and the spin ratio. Using the formulae derived, the condition for the onset of the inverse Magnus effect is suggested based on the negative lift generation mechanism.close0

Epidemiological, clinical, and microbiological characteristics of carbapenemase-producing Enterobacteriaceae bloodstream infection in the Republic of Korea

Abstract Background Carbapenemase-producing Enterobacteriaceae (CPE) is an important pathogen in nosocomial infections; nevertheless, only a few studies regarding CPE infection and its epidemiological factors have been conducted in the Republic of Korea (ROK). We aimed to analyze the clinical, microbiological, and epidemiological characteristics of CPE bloodstream infections (BSIs) in the ROK. Methods This retrospective cohort study included data collected from the National Surveillance System from January 2015 to December 2016 based on the epidemiologic survey performed by an epidemiologist from the Korea Centers for Disease Control and Prevention. We selected patients with CPE BSI from the Korea National Institute of Health based on carbapenemase genotyping. Results In this study, 131 CPE BSIs were identified, and the proportion of CPE BSI among total CPE isolates was 7%. Klebsiella pneumoniae accounted for 69% of all CPE BSIs, and 66% of these produced K. pneumoniae carbapenemase. Among nine provinces in ROK, one province had NDM as the most common carbapenemase. CPE was susceptible to amikacin, tigecycline, and gentamicin (76, 41, and 39%, respectively). Of 29 patients tested for colistin sensitivity, one patient showed colistin resistance. The most common CPE BSI sources were pneumonia, primary bacteremia, and biliary tract infection. Multivariable analysis showed that adequate antibiotic use at CPE detection was significantly associated with decreased 30-day mortality. Conclusions CPE BSIs are prevalent in the ROK. Moreover, most CPE BSIs originated from hospital-acquired infection, demonstrating the need to improve hospital infection control strategies