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The ensemble forecast system based on the Korea Integrated Model (KIM), which is developed for Korea’s own numerical weather prediction (NWP) model, has been in operation at Korean Meteorological Administration (KMA) since October 2021. KMA ensemble forecast system consists of 50 perturbation members (25 members for long-range forecast) and 1 control simulation. Four-dimensional LETKF (Local Ensemble Transform Kalman Filter) with additive and RTPS inflation scheme is used to make initial perturbation. Evaluation of forecast scores shows that our operational ensemble forecast system is generally more skillful compared to the deterministic simulation as forecast time is longer. Also, forecast with increased ensemble size produces better representation of atmospheric fields especially in higher latitudes. Details of results from operational ensemble system and impacts of increased ensemble size will be discussed with introducing a brief overview of our ensemble forecast system and development plan in future.

This paper studies the simulations of active airframe vibration controls for the Sikorsky X2 helicopter with a lift-offset coaxial rotor. The 4P hub vibratory loads of the X2TD rotor are obtained from the previous work using a rotorcraft comprehensive analysis code, CAMRAD II. The finite element analysis software, MSC.NASTRAN, is used to model the structural dynamics of the X2TD airframe and to analyze the 4P vibration responses of the airframe. A simulation study using Active Vibration Control System(AVCS) with Fx-LMS algorithm to reduce the airframe vibrations is conducted. The present AVCS is modeled using MATLAB Simulink. When AVCS is applied to the X2TD airframe at 250 knots, the 4P longitudinal and vertical vibration responses at the specified airframe positions, such as the pilot seat, co-pilot seat, engine deck, and prop gearbox, are reduced by 30.65 ~ 94.12 %.

Observations from uncrewed surface vehicles (saildrones) in the Bering, Chukchi, and Beaufort Seas during June – September 2019 were used to evaluate initial conditions and forecasts with lead times up to 10 days produced by eight operational numerical weather prediction centers. Prediction error behaviors in pressure and wind are found to be different from those in temperature and humidity. For example, errors in surface pressure were small in short-range (

Currently, the Korea Meteorological Administration (KMA) is operating two global models. One is the Unified Model (UM) developed by the United Kingdom Met Office, and the other is the Korean Integrated Model (KIM), which was developed by the Korea Institute of Atmospheric Prediction Systems (KIAPS) during a 9-year project funded by KMA. The UM global model has been operation since 2010, and the KIM global model since April 2020. The plan is that KIM will be the sole operational global model of KMA after retirement of the UM at the end of 2022. In this chapter, we introduce the data assimilation systems used with the two global models, and with the limited area models that are nested inside the global UM. The UM global model uses a hybrid-4DVar data assimilation system, while the KIM global model uses a hybrid-4DEnVar system. UM-based 1.5 km local and very short range forecast models cycled with 3DVar are also being operated. KMA also runs another very short range forecasting system with a 5 km grid spacing named the Korea Local Analysis and Prediction System (KLAPS) which is also cycled with 3DVar.

The proper representation of water vapor helps set accurate initial conditions in numerical weather prediction (NWP) models. Water vapor levels have been observed over the tropics by the Sounder for Atmospheric Profiling of Humidity in the Inter-tropics by Radiometry (SAPHIR) on the Megha-Tropiques (MT) satellite. To determine how tropical convection, which is relevant to water vapor levels, can affect medium-range forecasts in both the tropics and extratropics, we compare the differences between simulations with and without MT-SAPHIR data using the operational NWP model from the Korea Meteorological Administration (KMA), which includes a hybrid four-dimensional variational process in data assimilation. More observed water vapor in the lower tropical troposphere leads to stronger tropical convection, which is well represented in the 300 hPa velocity potential, and strengthens mean meridional circulation. Root-mean-square errors (RMSEs) for relative humidity, temperature, and wind fields in the tropics are reduced by up to 7%. This improvement enhances the forecast field in the middle latitudes. In particular, RMSEs are reduced by up to 3.5% in the humidity field in the extratropics. Overall, the correct simulation of tropical water vapor via MT-SAPHIR data improves medium-range forecasts in the extratropics.

Prospective study.The purpose of this study was to compare the long-term clinical and radiologic outcomes of hybrid surgery (HS) and 2-level anterior cervical discectomy and fusion (2-ACDF) in patients with 2-level cervical disk disease.In a previous study with a 2-year follow-up, HS was shown to be superior to 2-ACDF, with a better Neck Disability Index (NDI) score, less postoperative neck pain, faster C2-C7 range of motion (ROM) recovery, and less adjacent ROM increase.Between 2004 and 2006, 40 patients undergoing 2-level cervical disk surgery at our hospital were identified as 2-level degenerative disk disease. Forty patients were included in the previous study; 35 patients were followed up for 5 years. Patients completed the NDI and graded their pain intensity before surgery and at routine postoperative until 5 years. Dynamic cervical radiographs were obtained before surgery and at routine postoperative intervals and the angular ROM for C2-C7 and adjacent segments was measured.The HS group had better NDI recovery until 3 years after surgery (P0.05). Postoperative neck pain was lower in the HS group at 1 and 3 years after surgery (P0.05), but arm pain relief was not differently relieved. The HS group showed more angular ROM for C2-C7 at 2 and 3 years after surgery. The superior adjacent segment ROM showed hypermobility in the 2-ACDF group and hypomobility in the HS group at all follow-up periods without statistically significance, but the inferior adjacent segment ROM differed significantly (P0.05).HS is superior to 2-ACDF; it leads to better NDI recovery, less postoperative neck pain, faster C2-C7 ROM recovery, and less adjacent ROM increase over a 2-year follow-up, but these benefits of HS become similar to those of 2-ACDF with 5 years of follow-up.

Recently, the number of observations used in a data assimilation system is increasing due to the enormous amount of observations, including satellite data. However, it is not clear that all of these observations are always beneficial to the performance of the numerical weather prediction (NWP). Therefore, it is important to evaluate the effect of observations on these forecasts so that the observations can be used more usefully in NWP process. In this study, the adjoint-based Forecast Sensitivity to Observation (FSO) method with the KMA Unified Model (UM) is applied to two high-impact weather events which occurred in summer and winter in Korea in an effort to investigate the effects of observations on the forecasts of these events. The total dry energy norm is used as a response function to calculate the adjoint sensitivity. For the summer case, TEMP observations have the greatest total impact while BOGUS shows the greatest impact per observation for all of the 24-, 36-, and 48-hour forecasts. For the winter case, aircraft, ATOVS, and ESA have the greatest total impact for the 24-, 36-, and 48-hour forecasts respectively, while ESA has the greatest impact per observation. Most of the observation effects are horizontally located upwind or in the vicinity of the Korean peninsula. The fraction of beneficial observations is less than 50%, which is less than the results in previous studies. As an additional experiment, the total moist energy norm is used as a response function to measure the sensitivity of 24-hour forecast error to observations. The characteristics of the observation impact with the moist energy response function are generally similar to those with the dry energy response function. However, the ATOVS observations were found to be sensitive to the response function, showing a positive (a negative) effect on the forecast when using the dry (moist) norm for the summer case. For the winter case, the dry and moist energy norm experiments show very similar results because the adjoint of KMA UM does not calculate the specific humidity of ice properly such that the dry and moist energy norms are very similar except for the humidity in air that is very low in winter.

We present first results from a hybrid coplanar waveguide microfluidic tank circuit for monitoring lipid bilayer formation and fluctuations of integrated proteins. The coplanar waveguide is a radio frequency resonator operating at ~250 MHz. Changes within the integrated microfluidic chamber, such as vesicle bursting and subsequent nanopore formation alter the reflected signal, and can be detected with nanosecond resolution. We show experimental evidence of such alterations when the microfluidic channel is filled with giant unilamellar vesicles (GUVs). Subsequent settling and bursting of the GUVs form planar lipid bilayers, yielding a detectable change in the resonant frequency of the device. Results from finite element simulations of our device correlate well with our experimental evidence. These simulations also indicate that nanopore formation within the bilayer is easily detectable. The simulated structure allows for incorporation of microfluidics as well as simultaneous RF and DC recordings. The technique holds promise for high throughput drug screening applications and could also be used as an in-plane probe for various other applications. It opens up possibilities of exploring ion channels and other nano scale pores in a whole new frequency band allowing for operating at bandwidths well above the traditional DC methods.

The purpose of this study was to evaluate the potential of naturally occurring aldose reductase (AR) inhibitors from white-color natural products (Aruncus dioicus var. kamtschaticus, Chionanthus retusa, Cosmos bipinnatus, Hibiscus syriacus, Hydrangea paniculata, Magnolia denudata, Prunus padus, Robinia pseudo-accacia, Rhododendron mucronulatum for. albiflorum, Spiraea blumei, and Spiraea prunifolia var. simpliciflora). The MeOH extract of white-color natural products were tested on rat lens AR inhibition in vitro. Among them, the MeOH extract of R. mucronulatum for. albiflorum showed highest inhibition on AR (IC 50 value, 1.07 ㎍/ml). These results suggested that R. mucronulatum for. albiflorum, a white-color natural product, could be a useful resource in the development of a novel AR inhibitory agent against diabetic complications.

Bamboo is one of the fastest growing plants in the world and is an economically important crop species in Asia. To identify the genes involved in fast shoot growth, an expressed sequence tag analysis was performed on Bambusa edulis Murno fast-growing shoots. Sequencing of the cDNA clones generated 1,402 5′-end high-quality expressed sequence tags (JG296384-JG297785, average length 655 bp), of which 1,101 clusters (143 consensus and 958 singletons) were revealed by sequence comparison to be unique and 597 (54% of total clusters) of them have a putative ATG start codon. A Basic Local Alignment Search Tool X analysis showed that 995 of these genes were similar to genes present in the National Center for Biotechnology database. A total of 868 genes were most similar to rice genes. The most abundant genes were three thionin-coding genes, which have 27, 17, or 10 clones, respectively, followed by aminocyclopropanecarboxylate oxidase and cysteine protease. Thionin and putative cell elongation-associated genes, xyloglucan endotransglycosylase/hydrolase, expansin, cellulose synthase, and pectin esterase were analyzed by real-time reverse transcription polymerase chain reaction using gene-specific primers. These results suggest that this high-quality library could be a good resource for understanding molecular events of bamboo shoot elongation, and the full-length clones could be used for crop improvement studies in the future.

We evaluated the restoration effect by introducing willows as a means of controlling invasions of giant ragweed (Ambrosia trifida L.) on a riparian site. Our preliminary survey demonstrated that a problematic exotic species, giant ragweed and the representative riparian species, Salix koreensis are in competitive exclusive relationship. We planted willows at 1 m intervals on the bank of the Dongmun stream at Munsan, Paju, in Central Western Korea as an experimental restoration practice. We installed two 50 m ⅹ 5 m sized restored and non-restored for this experimental study. The non-restored plots were located on river banks, which were covered with concrete blocks and left in itself without any treatment. The height of willow was measured after each of three consecutive growing seasons and compared with the height of the giant ragweed. Although the height of Salix gracilistyla did not achieve the height of the giant ragweed, the height of S. koreensis surpassed that of giant ragweed in the third year after introduction. The results were also reflected in the relative light intensity on the herb layer of willow stand, and thereby the relative light intensities of stands, which were dominated by S. koreensis or restored by introducing S. koreensis, 1.99 ± 0.33 (%, mean ± SD) and 1.92 ± 0.50 (%, mean ± SD), respectively were lower than those in the stands treated by S. gracilistyla, 3.01 ± 0.43 (%, mean ± SD). The giant ragweed stands receive full sunlight as there are no any vegetation layers higher than the herb layer formed by the giant ragweed. As the result of Detrended Correspondence analysis ordination based on naturally established vegetation, the stands dominated by willows and giant ragweed showed different species composition between both stands. The species composition of the restoratively treated sites resembled the reference sites more than the non-treated sites. The species diversity (H’) of the sites restored by introducing S. koreensis and S. gracilistyla was higher than the non-restored site dominated by A. trifida . On the basis of our results, the restoration of riparian vegetation equipped with integrated features could contribute not only to the control of exotic plants including giant ragweed but also to ensure the diversity and stability of riverine ecosystems.

Object A ruptured dissecting aneurysm of the vertebrobasilar artery (VBA-DA) is a well-known cause of acute subarachnoid hemorrhage (SAH) with a high rate of early rebleeding. Internal trapping of the parent artery, including the dissected segment, is one of the most reliable techniques to prevent rebleeding. However, for a ruptured VBA-DA not suitable for internal trapping, the optimal treatment method has not been well established. The authors describe their experience in treating ruptured VBA-DAs not amenable to internal trapping of the parent artery with stent-assisted coil embolization (SAC) followed by a stent-within-a-stent (SWS) technique. Methods Eleven patients—6 men and 5 women with a mean age of 48 years and each with a ruptured VBA-DA not amenable to internal trapping of the parent artery—underwent an SAC-SWS between November 2005 and October 2007. The feasibility and clinical and angiographic outcomes of this combined procedure were retrospectively evaluated. Results The SAC-SWS was successful without any treatment-related complications in all 11 patients. Immediate posttreatment angiograms revealed complete obliteration of the DA sac in 3 patients, near-complete obliteration in 7, and partial obliteration in 1. One patient died as a direct consequence of the initial SAH. All 10 surviving patients had excellent clinical outcomes (Glasgow Outcome Scale Score 5) without posttreatment rebleeding during a follow-up period of 8–24 months (mean follow-up 15 months). Angiographic follow-up at 6–12 months after treatment was possible at least once in all surviving patients. Nine VBA-DAs showed complete obliteration; the other aneurysm, which had appeared partially obliterated immediately after treatment, demonstrated progressive obliteration on 2 consecutive follow-up angiography studies. There was no in-stent stenosis or occlusion of the branch or perforating vessels. Conclusions The SAC-SWS technique seems to be a feasible and effective reconstructive treatment option for a ruptured VBA-DA. The technique may be considered as an alternative therapeutic option in selected patients with ruptured VBA-DAs unsuitable for internal trapping of the parent artery.

Study Design. A prospective analysis. Objective. The purpose of this study was to compare the clinical and radiologic outcomes of cervical artificial disc replacement (C-ADR) combined with anterior cervical discectomy and fusion (ACDF) and 2-level ACDF in patients with 2-level cervical disc disease. Summary of Background Data. Adjacent segment degeneration is a long-term complication of ACDF, and estimated to affect 25% of patients within 10 years of the initial surgery. Two-level fusion leads to a substantially greater increase in intradiscal pressure than one-level fusion. It has been demonstrated that C-ADR maintains motion at the level of the surgical procedure and decreases strain on the adjacent segments for prevention of adjacent segment degeneration. In the case of 2-level cervical disc disease, hybrid surgery (HS), consisting of C-ADR combined with ACDF, may be a reasonable alternative to 2-level ACDF (2-ACDF). Methods. Between 2004 and 2006, 40 patients undergoing 2-level cervical disc surgery at our hospital were identified who met the following surgical indications: 2 consecutive level degenerative disc disease between C3/4 and C6/7; either a radiculopathy or myelopathy; and no response to conservative treatment for >6 weeks. Twenty patients of the HS group were matched to 20 patients of the 2-ACDF group based on age and gender. Patients were asked to check the neck disability index (NDI) and grade their pain intensity before surgery and at routine postoperative intervals of 1, 3, 6, 12, and 24 months. Dynamic flexion and extension lateral cervical radiographs were obtained in the standing position before surgery and at routine postoperative intervals of 1, 3, 6, 12, and 24 months. The angular range of motion (ROM) for C2―C7 and adjacent segments were measured using the Cobb method with PACS software. Results. The HS group had better NDI recovery 1 and 2 years after surgery (P < 0.05). Postoperative neck pain was less in the HS group 1 month and 1 year after surgery (P < 0.05). There was no difference in arm pain relief between the groups. The HS group showed faster C2―C7 ROM recovery. The mean C2―C7 ROM of the HS group recovered to that of the preoperative value, but that of the 2-ACDF group did not (P < 0.05). The inferior adjacent segment ROM showed significant differences between the groups 6 and 9 months, and 1 and 2 years after surgery (P < 0.05, P < 0.01, P < 0.05, and P < 0.05, respectively). Conclusion. HS is superior to 2-ACDF in terms of better NDI recovery, less postoperative neck pain, faster C2―C7 ROM recovery, and less adjacent ROM increase.

Department of Biology, Graduate School of Seoul Women's University, Seoul 139-774, KoreaABSTRACT: We analyzed the factors driving succession and the structure, and dynamics of vegetation on sand and gravel bars in order to clarify the differences in vegetation succession in rivers with different river bed sub-strates. Woody plant communities (dominated by Salix), perennial herb communities (dominated by Miscanthus), and annual plant communities (dominated by Persicaria) appeared in that order from upstream to downstream on the sandbar. The results of DCA ordination based on vegetation data reflected a successional trend. This result suggests that sandbars grow in a downstream direction. Various vegetation types different in successional stage, such as grassland, young stands of Korean red pine (Pinus densiflora), two-layered stands of young and mature pines, and mature pine stands also occurred on gravel bars, but the vegetation in earlier successional stage was established upstream, which is the opposite to the direction found on sandbars. Those results demonstrate that the dynamics of the bed load itself could be a factor affecting vegetation succession in rivers. In fact, sands suspended by running water were transported downstream over the vegetated area of sand bar and thereby created new areas of sandbar on the downstream end of the sandbar. Meanwhile, gravel, which is heavy and thereby is shifted by strong water currents, accumulated on the upstream end of the vegetated area, and thus created new areas of gravel bar in that direction. These results showed that allogenic processes drive vegetation succession on sand and gravel bars in streams and rivers.Key words: Allogenic process, Gravel bar, Sand bar, Succession, Vegetation

This study was carried out to evaluate the relationships between stand attributes and litterfall amounts in a 28-year old Quercus acutissima stand. Eighteen sampling plots of were chosen and litterfall was collected from May 2005 to December 2006. There was no correlation between stand attributes(tree density, mean diameter at breast height, mean height, basal area) and litterfall amounts except for flower and miscellaneous litter for the study period. There were no significant relationships between leaf litter and basal area(r

Object The objective of this study was to evaluate the invasiveness of microendoscopic discectomy (MED) in comparison with microscopic discectomy (MD) by measuring serum levels of creatine phosphokinase (CPK)-MM and lactate dehydrogenase (LDH)-5, and by comparing visual analog scale (VAS) scores of postoperative pain. Methods This study included a group of 15 patients who underwent surgery using MED and 15 patients who underwent surgery using MD, both for single-level unilateral herniated nucleus pulposus. The CPK-MM and LDH-5 levels were measured at admission and after 1, 3, and 5 days postoperatively. Pain assessment was recorded using scores raging from 0 to 10 on a subjective VAS at admission and at 1, 3, and 5 days postoperatively. Results The mean CPK-MM levels were lower for the MED group than for the MD group at both 3 (576.1 ± 286.3 IU/L compared with 968.1 ± 377.8 IU/L) and 5 days (348.1 ± 231.0 IU/L compared with 721.7 ± 463.2) postoperatively (p < 0.05). The mean VAS scores for postoperative back pain were lower in the MED group than in the MD group, both at 1 (3.3 ± 2.3 compared with 5.8 ± 1.5) and 5 days (1.9 ± 1.1 compared with 3.6 ± 1.1) postoperatively (p < 0.01). Conclusions The MED procedure is less invasive than MD, and causes less muscle damage and less back pain.

Genus Phyllostachys is a long-lived woody species primarily distributed throughout South East Asia. Many species of this genus has been regarded as medically and ecologically important in the world. We evaluated representative samples of the four taxa with RAPD to estimate genetic relationships within the genus Phyllostachys. The percentages of polymorphic loci were 8.9-33.3% at the species level. P. bambusoides was found to show lower genetic diversity (H=0.018) than other species. Total genetic diversity (H T ) was 0.315, genetic diversity within populations (H S ) was 0.043, the proportion of total genetic diversity partitioned among populations (G ST ) was 0.659 and the gene flow (Nm) was 0.0263. As some Korean populations were isolated and patchily distributed, they exhibited low levels of genetic diversity. The four taxa of the genus Phyllostachys analyzed were distinctly related to a monophyletic. P. nigra var. henonis. Stapf was found to be more closely related to P. pubescens than to P. nigra. P. bambusoides was quite distinct from the remaining species.

Korean rivers and their surrounding environments have been used excessively for rice production in the past and more recently for construction of urban areas to accomodate the rapidly increasing population. Affected Korean rivers experience dramatic fluctuations in their water levels and have faster currents compared with those in other countries. In order to restore more natural conditions in rivers experiencing such conditions, we employed a partial restoration method, which is designed to achieve physical and biological stability simultaneously. Concrete blocks were introduced to increase the river`s physical stability during floods, and terra cottem, a soil enhancer, was used to reduce water loss due to intense heat. These interventions increased the river`s ability to hold water and thereby promoted plant growth. This restoration method increased vegetation coverage and species diversity in treated areas, and changed the species composition in treated areas to more closely approximate that of the control site. These results suggest that this method is effective in restoring damaged habitats to more natural conditions.

This paper presents a low-cost bidirectional (BiDi) wavelength-division-multiplexed passive optical network (WDM-PON) employing colorless uncooled BiDi transceivers (TRxs) and superluminescent diode (SLD)-based broadband light sources (BLSs). The C band is allocated for upstream and the E+ band for downstream in consideration of BiDi packaging, SLD development, and wavelength alignment of dual-window arrayed waveguide gratings (AWGs). The BiDi TRx integrates an uncooled Fabry-Perot laser diode (FP-LD), a p-i-n photodiode (PD), and a 45/spl deg/-angled thin-film filter in a small-form-factor (SFF) package. The SLD-based BLSs provide 13-dBm amplified spontaneous emissions (ASEs) with spectral ripples of < 3 dB and polarization dependencies of

This study was carried out to estimate above-ground biomass and inorganic nutrient distribution for a Camellia japonica stand located Mt. Cheon-gwan, Jeonnam province. Regression analysis of biomass for stem, current twig, branch and foliage versus diameter at breast height(DBH) was used to calculate regression equations of the form of logY

We demonstrate a gain-clamped semiconductor optical amplifier (GC-SOA) which has gratings under both end regions of an active waveguide. Two gratings of the new GC-SOA are fabricated in different lengths. Their lasing modes and gain characteristics are measured and analyzed with different combinations of grating lengths. It shows different gain and noise characteristics according to the measurement direction in asymmetric grating combinations.

We outline the fabrication of piezoelectric through-pores in crystalline quartz using a rapid micromachining process, and demonstrate piezoelectric deformation of the pore. The single-step fabrication technique combines ultraviolet (UV) laser irradiation with a thin layer of absorbing liquid in contact with the UV-transparent quartz chip. The effects of different liquid media are shown. We demonstrate that small exit pores, with diameters nearing the 193 nm laser wavelength and with a smooth periphery, can be achieved in 350 μm thick quartz wafers. Special crater features centring on the exit pores are also fabricated, and the depth of these craters are tuned. Moreover, by applying a voltage bias across the thickness of this piezoelectric wafer, we controllably contract and expand the pore diameter. We also provide a sample application of this device by piezoelectrically actuating alamethicin ion channels suspended over the deformable pore.

High-throughput screening of ion channels is now possible with the advent of the planar patch clamp system. This system drastically increases the number of ion channels that can be studied, as multiple ion channel experiments can now be conducted in parallel. However, due to tedious, usually pressure-driven mechanotransduction techniques, there has been a slow integration of this technology into the field of mechanosensitive ion channels. By implementing a piezoelectric quartz substrate into a planar patch clamp system, we show that the patch clamp substrate itself can be used to mechanically actuate ion channels. The piezoelectric substrate transduces an external, applied electric field into a mechanical tension, so precise actuation of the membrane can be accomplished. By applying this electric field only to the outer edges of the substrate, no ulterior electric field is created in the vicinity of the membrane during actuation. Further, with resonant frequencies ranging from 1 kHz to 200 MHz, quartz substrates can be used to apply a wide range of time-varying tensions to cell membranes. This will allow for new and instructive investigations into the dynamic mechanotransductive properties of ion channels.

We show that a single-crystal quartz substrate provides a working platform for ion channel research. Single-crystal quartz is piezoelectric, so it can be nanomechanically actuated to perform precise membrane deformations. This, along with its superior noise properties, makes single-crystal quartz ideal for analyzing mechanosensitive ion channels.

Stochastic resonance refers to the increased sensitivity of a system when a finite level of noise is applied to the system. This counter-intuitive concept is evidenced by a maximum in the signal-to-noise ratio with respect to applied noise level. We have applied this technique to a system of alamethicin ion channels incorporated in a planar lipid bilayer. When used as a molecular biosensor, an enhancement of the signal-to-noise ratio of such a system improves the sensor's limit of detection. Thus, by adding noise to the biosensor, we can maximize its sensitivity. We also show how this technique can be used to design an inherently optimal molecular biosensor. By varying the lipid membrane area, the alamethicin concentration, and applied voltage in each system, we control the level of noise internal to the system. Then, by noting the level of external noise that induces stochastic resonance, we inferred the level of internal noise that each variable introduces to the system. In doing so, we found that microphonic noise, which is introduced by the lipid membrane, most significantly influences the signature of stochastic resonance. Thus, we have shown that by tuning the membrane area to induce an optimal level of microphonic noise, one can design a molecular biosensor that inherently induces stochastic resonance.

Purpose: A retrospective review of medical records and imaging studies. To investigate characteristic clinical features and surgical outcomes of spinal cord tumors (SCTs) of the thoracolumbar junction (TLJ). The spinal cord transitions to the cauda equina in the TLJ. The TLJ contains the upper and lower motor neurons of the spinal cord and cauda equina. As a result, the clinical features of lesions in the TLJ vary, and these anatomical characteristics may affect surgical outcome. Materials and Methods: Pathological diagnosis, clinical features, neurological signs, and surgical outcomes were investigated in 76 patients surgically treated at our institute for SCTs arising from T11 to L2. The patients were divided into epiconus (T11-12, n = 18) and conus groups (L1-2, n = 58). Results: Patients in the epiconus group had hyperactive deep tendon reflexes (DTRs), while those in the conus group had hypoactive DTRs (p < 0.05). Nine patients were misdiagnosed with intervertebral disc diseases (IVDs) before correct diagnoses were made. It was impossible to definitively determine the exact cause of symptoms in four patients who had both SCTs and IVDs. Conclusion: Among SCTs of the TLJ, the epiconus group displayed upper motor neuron syndrome and the conus group displayed lower motor neuron syndrome. SCTs of the TLJ were frequently misdiagnosed as IVDs due to symptomatic similarities. SCTs of the TLJ should be included in differential diagnosis of back and leg pain, and it is highly recommended that routine lumbar magnetic resonance imaging include the TLJ.

Overproduction of amyloid precursor protein (APP) and beta-amyloid likely contribute to neurodegeneration in Alzheimer's disease (AD). In an effort to understand neuronal APP gene regulation, we identified a 52 base element (52sce) immediately downstream from the stop codon that stabilizes APP mRNA. Deletion of this domain drastically destabilized APP mRNAs and reduced APP synthesis in vitro. Chimeric globin-APP mRNAs containing the globin coding sequence fused to the entire APP 3'-UTR, showed regulation similar to full-length APP mRNA. A variety of cytoplasmic lysates contain 52sce RNA binding activity, suggesting cis-trans interactions regulate the element's functionality. Finally, the overexpression of chimeric mRNAs, containing the GFP coding sequence and APP 3'-UTR, dramatically reduced endogenous APP steady-state levels in SH-SY5Y neuroblastoma cells and suggests a novel approach to reduce the amyloid burden in AD patients.

We developed polarization-independent high-power superluminescent diodes (SLDs) for wavelength division multiplexed-passive optical network (WDM-PON) applications. The SLD presents CW output power of 150 mW, spectral bandwidth of 40 nm, polarization-dependent power variation of less than 1 dB, and spectral ripple of 3 dB at current of 1.47 A and temperature of 25 degC

We present a low-cost C/S-band WDM-PON employing colorless uncooled bidirectional transceivers and SOA-based broadband light sources. Colorless operations over 32 DWDM channels are demonstrated from -20 to 80/spl deg/C in 155-Mb/s bidirectional transmissions over 25 km.

We present R-SOAs with improved modulation bandwidth of /spl sim/1.35 GHz as WDM sources in 1.25 Gbit/s WDM-PONs. In back-to-back transmission using the R-SOA seeded by 0.6 nm-wide ASE of -20 dBm, receiver sensitivity at a 10/sup -9 /BER was - 25.3 dBm.

Research on ion channels are traditionally performed in the DC regime. Only a few attempts having been made to conduct RF measurements for probing ion channel properties. We present here simulations and subsequent measurements of an integrated coplanar waveguide and microfluidic tank circuit detecting bilayer formation. We observe a 5 MHz shift in resonant frequency and a 1.4 dB shift in amplitude when a lipid bilayer is formed. These measurements allow for in-vitro radio frequency recordings with nanosecond readout times. The designed structure also enables the incorporation of simultaneous RF and DC recordings from lipid bilayer embedded proteins such as ion channels.

Quartz substrates are attractive platforms for ion channel research, owing to their improved dielectric properties over currently used substrates. Further, the piezoelectric properties of quartz make it an ideal candidate for probing mechanosensitive ion channels. Here we present evidence of planar lipid bilayer formation on a laser-drilled quartz substrate in transport measurements. Bilayer formation is evidenced by the incorporation of voltage-gated ion channels in the membrane.