ObjectivePathophysiological mechanisms underlying generation of hippocampal spike is unknown. We analyzed interictal epileptiform activities intraoperatively recorded from the hippocampus and other temporal regions of patients with temporal lobe epilepsy (TLE).MethodsEleven TLE patients with (N=6) or without (N=5) hippocampal sclerosis were included in this study. All of the patients underwent CT, MR Imaging and video-EEG monitoring before the operation for localizing seizure onset and diagnosed as having unilateral mesial temporal lobe focus. After opening the anterior horn of lateral ventricle, recording was made under sevoflurane anesthesia using intrahippocampal multiple electrodes, hippocampal surface electrodes and temporo basal subdural electrodes.Results(1) Frequency of intrahippocampal spike was always higher than spikes from other areas. (2) Intrahippocampal recording demonstrated that there was phase reversal in sclerotic hippocampi but there was not in nonsclerotic hippocampi.(3) Even one transection perpendicular to the long axis desynchronized hippocampal spike.ConclusionWe speculate that the phase reversal occurred at the hippocampal sulcus and the subiculum was the spike generator in sclerotic hippocampus. Mechanisms underlying spike generation is likely to be different between sclerotic hippocampi and nonsclerotic hippocampi. Longitudinal synchronization may be essential for generation of hippocampal spikes. Our data show that hippocampal spikes almost always occur synchronously in different hippocampal regions; Emerson et al (1) have reported that propagation commonly happens from anterior to posterior regions.
Background COVID-19 is a respiratory tract disease, caused by new corona virus, was first\nrecognized in Wuhan, China, December 2019. WHO declared it as pandemic on 30 January 2020\nObjectives:To assess relationship between Temperature and humidity and the spread of COVID-\n19 in the top affected regions Methods:We approached a systemic review on 25th of March 2020\nof WHO reports which were 64 by 24th of March regarding number of cases and\ndeaths.Temperature and humidity from December 2019 to June 2020 of the most affected\nregions regarding top 10 affected countries were reviewed using Google weather information\nand AccuWeather.com to asses any relation between them and COVID-19 spread Results: Total\nnumber of cases till 24th of March WHO report was 372755 ,84.84% occur in Top 10 countries;\nChina(81747) ,Italy (63927),United States of America (42164), Spain (33089) ,Germany (29212)\n,Iran(23049),France(19615),South Korea(9037),Switzerland( 8015),United Kingdom (6654).The\nstart of the pandemic and the peak in number of cases in affected regions were all within a\nfavored temperature (40 –55 Fahrenheit ‘F’) and humidity (40-55%) and with increasing weather\ntemperature & humidity the number of cases dropped Conclusion:COVID-19 has favorable\ntemperature and humidity.Pandemic peak reached its end in Wuhan(temperature 68 F-humidity\n88%),resolving in Seoul(temperature 66.2 F-humidity 53%), expected to resolve in Italy ,USA ,\nand Spain in half of April 2020 to its end , and in Germany ,France ,UK and Switzerland in May\nto June 2020.Increasing temperature above 55 F in areas where you can control it , may have\nbeneficial role in controlling COVID-19.
Dispersive soils are characterized by an unstable structure (disperse and crumb easily and rapidly) without significant mechanical assistance in water of low-salt concentration. These soils are highly erodible in nature and tend to erode under low flow rate. Using dispersive soils in different structures like dams, embankment and roadway may cause serious engineering problems which are worldwide, and several structure failures have occurred and reported in many countries. Soil dispersion is a physical–chemical phenomenon that is caused due to presence of certain approach each other. However, in many countries, this material covers a substantial land area and identification of these soils is necessary for geotechnical engineers. In this paper, the dispersive soils and their mechanism are described from chemistry view point, furthermore the dispersive soil identification methods are discussed in the perspective of qualitative methods evaluations; the advantages and disadvantages of these methods are discussed as well.
Rain drop size and isotopic composition of rain, important parameters that shed light on rain formation processes, are highly sensitive to the ambient weather. We reported earlier a significant correlation between them in individual rain events (with limited sampling), but this is yet to be tested with better, longer term sampling. Here we attempt to do so over a tropical region (i.e. Tirupati, India). Rain samples were collected at short time intervals (<1 h) to capture even small variations their stable oxygen (δ18O) and hydrogen (δD) isotopic compositions. Isotopic analyses were made using an isotope ratio mass spectrometer, and a Joss-Waldvogel disdrometer measured the drop size distribution (DSD). Summer rains show a progressive isotopic depletion with time, while the winter rains fluctuate about a mean value. We find no definite correlation between the drop size and stable isotope ratios as was reported earlier, based on a smaller number of samples: the complexity of rain formation process and varying ambient weather conditions for individual rain events could be the reason. Further, there is no significant difference between the local meteoric water lines (δ18O- δD line) of summer and winter monsoon rains, though the intercepts in both the cases were significantly smaller than global meteoric waterline (GMWL), suggesting the significant influence of secondary evaporation. However, the winter rains are isotopically depleted in both 18O and D. Paleoclimate proxies such as δ18O of cave calcite or teak cellulose form this region need to be interpreted in terms of the relative seasonality of the rainfall rather than the total annual rain.