101 research outputs found

    Global land surface temperature influenced by vegetation cover and PM2.5 from 2001 to 2016

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    Land surface temperature (LST) is an important parameter to evaluate environmental changes. In this paper, time series analysis was conducted to estimate the interannual variations in global LST from 2001 to 2016 based on moderate resolution imaging spectroradiometer (MODIS) LST, and normalized difference vegetation index (NDVI) products and fine particulate matter (PM2.5) data from the Atmospheric Composition Analysis Group. The results showed that LST, seasonally integrated normalized difference vegetation index (SINDVI), and PM2.5 increased by 0.17 K, 0.04, and 1.02 �g/m3 in the period of 2001–2016, respectively. During the past 16 years, LST showed an increasing trend in most areas, with two peaks of 1.58 K and 1.85 K at 72�N and 48�S, respectively. Marked warming also appeared in the Arctic. On the contrary, remarkable decrease in LST occurred in Antarctic. In most parts of the world, LST was affected by the variation in vegetation cover and air pollutant, which can be detected by the satellite. In the Northern Hemisphere, positive relations between SINDVI and LST were found; however, in the Southern Hemisphere, negative correlations were detected. The impact of PM2.5 on LST was more complex. On the whole, LST increased with a small increase in PM2.5 concentrations but decreased with a marked increase in PM2.5. The study provides insights on the complex relationship between vegetation cover, air pollution, and land surface temperature

    Deletion of Kncn Does Not Affect Kinocilium and Stereocilia Bundle Morphogenesis and Mechanotransduction in Cochlear Hair Cells

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    Auditory hair cells possess stunning cilia structure that composes of a bundle of stereocilia for mechano-electrical transduction and a single kinocilium for guiding the polarity of hair bundle towards maturation. However, the molecules underlying kinocilium function have not yet been fully understood. Hence, the proteins involved in hair bundle development and function are of a large interest. From a fine microarray analysis, we found that kinocilin (Kncn) was enriched in hair cell specific expression profile. Consistently, it has been reported that KNCN was a protein mainly located in the kinocilium of hair cells in the inner ear. However, the hypothesis that KNCN is a kinocilium protein has not been validated in mice with Kncn gene perturbed. In this study, we generated Kncn knockout mouse lines by CRISPR/Cas9 technique and further examined the morphology and function of cochlear hair cells. Our results showed that there was no obvious hearing loss in the knockout mice, determined by audiometry. Histological study demonstrated that the inner ear and hair cell structure were intact. Especially, there was no deficit of mechanotransduction (MET) in cochlear outer hair cells (OHCs). In summary, our work suggests that KNCN is not essential for kinocilium-oriented hair bundle function in cochlear hair cells

    Cognitive impairment in diffuse axonal injury patients with favorable outcome

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    Background and purposeTraumatic brain injury (TBI), especially the severe TBI are often followed by persistent cognitive sequalae, including decision-making difficulties, reduced neural processing speed and memory deficits. Diffuse axonal injury (DAI) is classified as one of the severe types of TBI. Part of DAI patients are marginalized from social life due to cognitive impairment, even if they are rated as favorable outcome. The purpose of this study was to elucidate the specific type and severity of cognitive impairment in DAI patients with favorable outcome.MethodsThe neurocognition of 46 DAI patients with favorable outcome was evaluated by the Chinese version of the Montreal Cognitive Assessment Basic (MoCA-BC), and the differences in the domains of cognitive impairment caused by different grades of DAI were analyzed after data conversion of scores of nine cognitive domains of MoCA-BC by Pearson correlation analysis.ResultsAmong the 46 DAI patients with favorable outcome, eight had normal cognitive function (MoCA-BC ≥ 26), and 38 had cognitive impairment (MoCA-BC < 26). The MoCA-BC scores were positively correlated with pupillary light reflex (r = 0.361, p = 0.014), admission Glasgow Coma Scale (GCS) (r = 0.402, p = 0.006), and years of education (r = 0.581, p < 0.001). Return of consciousness (r = −0.753, p < 0.001), Marshall CT (r = −0.328, p = 0.026), age (r = −0.654, p < 0.001), and DAI grade (r = −0.403, p = 0.006) were found to be negatively correlated with the MoCA-BC scores. In patients with DAI grade 1, the actually deducted scores (Ads) of memory (r = 0.838, p < 0.001), abstraction (r = 0.843, p < 0.001), and calculation (r = 0.782, p < 0.001) were most related to the Ads of MoCA-BC. The Ads of nine cognitive domains and MoCA-BC were all proved to be correlated, among patients with DAI grade 2. However, In the DAI grade 3 patients, the highest correlation with the Ads of MoCA-BC were the Ads of memory (r = 0.904, p < 0.001), calculation (r = 0.799, p = 0.006), orientation (r = 0.801, p = 0.005), and executive function (r = 0.869, p = 0.001).ConclusionDAI patients with favorable outcome may still be plagued by cognitive impairment, and different grades of DAI cause different domains of cognitive impairment

    Using the Surface Temperature-Albedo Space to Separate Regional Soil and Vegetation Temperatures from ASTER Data

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    Soil and vegetation component temperatures in non-isothermal pixels encapsulate more physical meaning and are more applicable than composite temperatures. The component temperatures however are difficult to be obtained from thermal infrared (TIR) remote sensing data provided by single view angle observations. Here, we present a land surface temperature and albedo (T-α) space approach combined with the mono-surface energy balance (SEB-1S) model to derive soil and vegetation component temperatures. The T-α space can be established from visible and near infrared (VNIR) and TIR data provided by single view angle observations. This approach separates the soil and vegetation component temperatures from the remotely sensed composite temperatures by incorporating soil wetness iso-lines for defining equivalent soil temperatures; this allows vegetation temperatures to be extracted from the T-α space. This temperature separation methodology was applied to advanced scanning thermal emission and reflection radiometer (ASTER) VNIR and high spatial resolution TIR image data in an artificial oasis area during the entire growing season. Comparisons with ground measurements showed that the T-α space approach produced reliable soil and vegetation component temperatures in the study area. Low root mean square error (RMSE) values of 0.83 K for soil temperatures and 1.64 K for vegetation temperatures, respectively, were obtained, compared to component temperatures measurements from a ground-based thermal camera. These results support the use of soil wetness iso-lines to derive soil surface temperatures. It was also found that the estimated vegetation temperatures were extremely close to the near surface air temperature observations when the landscape is well watered under full vegetation cover. More robust soil and vegetation temperature estimates will improve estimates of soil evaporation and vegetation transpiration, leading to more reliable the monitoring of crop water stress and drought

    Direct Evidence of Ice Crystallization Inhibition by Dielectric Relaxation of Hydrated Ions

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    In this paper, the inhibition effect of an alternative current (AC) electric field on ice crystallization in 0.9 wt % NaCl aqueous solution was confirmed thermodynamically with characterization. An innovative experimental and analytical method, combining differential scanning calorimeter (DSC) measurement with an externally applied electric field was created by implanting microelectrodes in a sample crucible. It was found that the ice crystallization, including pure ice and salty ice, was obviously inhibited after field cooling with an external AC electric field in a frequency range of 100 k–10 MHz, and the crystallization ratio was related to frequency. Compared with non-field cooling, the crystallization ratio of ice crystals was reduced to less than 20% when E = 57.8 kV/m and f = 1 MHz. The dielectric spectrum results show that this inhibition effect of an alternating electric field on ice crystal growth is closely related to the dielectric relaxation process of hydrated ions

    Spatio-Temporal Prediction Based Algorithm for Parallel Improvement of HEVC

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    Objective Functions and Performance Optimization of Ocean Thermal Energy Conversion (OTEC) with CO<sub>2</sub>-Based Binary Zeotropic Mixture Power Cycle

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    Ocean thermal energy is a huge renewable and clean energy. For different applications of the Ocean Thermal Energy Conversion (OTEC) system, new objective functions are proposed and optimal CO2-based binary zeotropic mixtures for each objective function are discussed. Propane, butane, isobutane, and pentane were selected as the secondary component of the mixture working fluid. Based on each objective function, some parameters of the CO2-based binary zeotropic mixture power cycle were studied and the optimal working fluids were obtained. The results indicated that the thermal efficiency showed an upwards trend as the evaporating temperature increased from 20 to 23 °C and decreased as the molar fraction of the secondary component of the working fluid increased from 0.01 to 0.05, but the specific volumetric flow showed the opposite trend. The specific net power increased as the evaporating temperature increased, and the net power output had a greater effect on the variations in the specific net power than the molar fraction of the secondary component. When taking thermal efficiency or specific volumetric flow as the objective functions, CO2/propane was the suitable working fluid under the considered conditions; in the case that specific net power was taken as the objective function, CO2/butane (0.97/0.03 or 0.96/0.04 molar ratio) or CO2/isobutane (0.97/0.03, 0.96/0.04, or 0.95/0.05 molar ratio) were suitable under the considered evaporating temperature
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