Spontaneous Oscillatory Rhythm in Retinal Activities of Two Retinal Degeneration (rd1 and rd10) Mice

Previously, we reported that besides retinal ganglion cell (RGC) spike, there is ~ 10 Hz oscillatory rhythmic activity in local field potential (LFP) in retinal degeneration model, rd1 mice. The more recently identified rd10 mice have a later onset and slower rate of photoreceptor degeneration than the rd1 mice, providing more therapeutic potential. In this study, before adapting rd10 mice as a new animal model for our electrical stimulation study, we investigated electrical characteristics of rd10 mice. From the raw waveform of recording using 8×8 microelectrode array (MEA) from in vitro-whole mount retina, RGC spikes and LFP were isolated by using different filter setting. Fourier transform was performed for detection of frequency of bursting RGC spikes and oscillatory field potential (OFP). In rd1 mice, ~10 Hz rhythmic burst of spontaneous RGC spikes is always phase-locked with the OFP and this phase-locking property is preserved regardless of postnatal ages. However, in rd10 mice, there is a strong phase-locking tendency between the spectral peak of bursting RGC spikes (~5 Hz) and the first peak of OFP (~5 Hz) across different age groups. But this phase-locking property is not robust as in rd1 retina, but maintains for a few seconds. Since rd1 and rd10 retina show phase-locking property at different frequency (~10 Hz vs. ~5 Hz), we expect different response patterns to electrical stimulus between rd1 and rd10 retina. Therefore, to extract optimal stimulation parameters in rd10 retina, first we might define selection criteria for responding rd10 ganglion cells to electrical stimulus

New Era of Air Quality Monitoring from Space: Geostationary Environment Monitoring Spectrometer (GEMS)

GEMS will monitor air quality over Asia at unprecedented spatial and temporal resolution from GEO for the first time, providing column measurements of aerosol, ozone and their precursors (nitrogen dioxide, sulfur dioxide and formaldehyde). Geostationary Environment Monitoring Spectrometer (GEMS) is scheduled for launch in late 2019 - early 2020 to monitor Air Quality (AQ) at an unprecedented spatial and temporal resolution from a Geostationary Earth Orbit (GEO) for the first time. With the development of UV-visible spectrometers at sub-nm spectral resolution and sophisticated retrieval algorithms, estimates of the column amounts of atmospheric pollutants (O3, NO2, SO2, HCHO, CHOCHO and aerosols) can be obtained. To date, all the UV-visible satellite missions monitoring air quality have been in Low Earth orbit (LEO), allowing one to two observations per day. With UV-visible instruments on GEO platforms, the diurnal variations of these pollutants can now be determined. Details of the GEMS mission are presented, including instrumentation, scientific algorithms, predicted performance, and applications for air quality forecasts through data assimilation. GEMS will be onboard the GEO-KOMPSAT-2 satellite series, which also hosts the Advanced Meteorological Imager (AMI) and Geostationary Ocean Color Imager (GOCI)-2. These three instruments will provide synergistic science products to better understand air quality, meteorology, the long-range transport of air pollutants, emission source distributions, and chemical processes. Faster sampling rates at higher spatial resolution will increase the probability of finding cloud-free pixels, leading to more observations of aerosols and trace gases than is possible from LEO. GEMS will be joined by NASA's TEMPO and ESA's Sentinel-4 to form a GEO AQ satellite constellation in early 2020s, coordinated by the Committee on Earth Observation Satellites (CEOS)

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

Serum FGF21 Levels in Obese Korean Children and Adolescents

Background : Serum fibroblast growth factor 21 (FGF21) has been suggested to be a possible biomarker for early detection of metabolic syndrome and type 2 diabetes in adults. However, few studies have investigated the correlation between FGF21 levels and metabolic parameters in children. This study sought to evaluate the relationship between FGF21 and metabolic parameters in obese Korean children and adolescents. Methods : Fasting serum FGF21 and adiponectin levels as well as fasting insulin, glucose, transaminases, and lipid profiles were measured by enzyme-linked immunosorbent assays in 45 lean and 70 obese children aged 7–14 years. Independent t-test and multivariate correlation analysis were used to evaluate the relationship between FGF21 and metabolic parameters. Results : Serum FGF21 was significantly higher in obese children than in lean children. Serum FGF21 levels were positively correlated with insulin resistance index homeostasis model assessment (HOMA-IR) (r=0.355, P=0.004) and triglycerides (r=0.423, P<0.001) and were negatively correlated with high-density lipoprotein (HDL) cholesterol (r=−0.412, P<0.001). After adjustment for body mass index, triglycerides, HDL cholesterol and adiponectin, FGF21 levels showed a significant correlation with only HOMA-IR on multivariate linear regression analysis. Conclusion : Serum FGF21 levels were higher in obese children and significantly correlated with HOMA-IR. Therefore, FGF21 could be a biomarker for obesity-induced insulin resistance in children and adolescents as indicated in adults

Do controlling shareholders' expropriation incentives imply a link between corporate governance and firm value? Theory and evidence

We develop and test a model that investigates how controlling shareholders' expropriation incentives affect firm values during crisis and subsequent recovery periods. Consistent with the prediction of our model, we find that, during the 1997 Asian financial crisis, Asian firms with weaker corporate governance experience a larger drop in their share values but, during the post-crisis recovery period, such firms experience a larger rebound in their share values. We also find consistent evidence for Latin American firms during the 2001 Argentine economic crisis. Our results support the view that controlling shareholders' expropriation incentives imply a link between corporate governance and firm value

Outcome of intentionally replanted molars according to preoperative periapical lesion and tooth location.

Background/purpose: The aims of this retrospective study were to assess the influence of preoperative periapical lesions on the healing of intentionally replanted teeth and compare outcomes of intentional replantation (IR) between maxillary and mandibular molars. Materials and methods: In this study, we retrospectively analyzed 79 cases in whom the IR procedure was used. The outcome of treatment was classified clinically and radiographically as either success or failure. Results: The overall success rate of the reviewed IR procedures was 68.7%. The success rate of IR with mandibular molars (78.0%) was significantly higher than that with maxillary molars (41.2%). There was no significant difference between success rates of IR for teeth with and without preoperative periapical lesions (66.7% vs. 72.0%, respectively). Conclusions: Within the limitations of this study, IR of mandibular molars seemed to provide a higher success rate than that for maxillary molars, regardless of the presence of preoperative periapical lesions.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/0000027976/6SEQ:6PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:0000027976ADJUST_YN:NEMP_ID:A076085DEPT_CD:861CITE_RATE:.222FILENAME:JDS77.pdfDEPT_NM:치의학과EMAIL:[email protected]_YN:NCONFIRM:YCONFIRM:

Clinicopathologic characteristics and survival rate in patients with synchronous or metachronous double primary colorectal and gastric cancer

Purpose Double primary colorectal cancer (CRC) and gastric cancer (GC) represent the most common multiple primary malignant tumors (MPMT) in Korea. The recognition and screening of hidden malignancies other than the primary cancer are critical. This study aimed to investigate the clinicopathologic characteristics and survival rates in patients with synchronous or metachronous double primary CRC and GC. Methods Between January 1994 and May 2018, 11,050 patients were diagnosed with CRC (n=5,454) or GC (n=5,596) at Gil Medical Center. MPMT and metastatic malignant tumors were excluded from this study. A total of 103 patients with double primary CRC and GC were divided into two groups: the synchronous group (n=40) and the metachronous group (n=63). The incidence, clinicopathologic characteristics, and survival rate of the two groups were analyzed. Results The incidence of synchronous and metachronous double primary CRC and GC was 0.93%. Double primary CRC and GC commonly occurred in male patients aged over 60 years with low comorbidities and minimal previous cancer history. There were significant differences between the synchronous and metachronous groups in terms of age, morbidity, and overall survival. Metachronous group patients were 6 years younger on average (P=0.009), had low comorbidities (P=0.008), and showed a higher 5-year overall survival rate (94.8% and 61.3%, P<0.001) in contrast to synchronous group. Conclusion When primary cancer (CRC or GC) is detected, it is important to be aware of the possibility of the second primary cancer (GC or CRC) development at that time or during follow-up to achieve early detection and better prognosis