854 research outputs found
Collaboration Between Nonprofit Universities and Commercial Enterprises: The Rationale for Exempting Nonprofit Universities from Federal Income Taxation
Sharpening land use maps and predicting the trends of land use change using high resolution airborne image: A geostatistical approach
High quality land use/land cover (LULC) data with fine spatial resolution and frequent temporal coverage are indispensable for revealing detail information of the Earth’s surface, characterizing LULC of the area, predicting the plausible land use changes, and assessing the viability and impacts of any development plans. While airborne imagery has high spatial resolution, it only provides limited temporal coverage over time. The LULC data from historical remote sensing images, such as those from Landsat, have frequent coverages over a long temporal period, but their spatial resolutions are low.
This paper presents a spatio-temporal Cokriging method to sharpen LULC data and predict the trends of land use change. A set of time-series coarse resolution LULC maps and one frame of high spatial resolution airborne imagery of the Upper Mill Creek Watershed were used to illustrate the utility of our method. By explicitly describing the spatio-temporal dependence within and between different datasets, modelling the Anderson classification codes using spatial, temporal, and cross-covariance structures, and transforming the Anderson integer classification code to class probability, our method was able to resolve the differences between multi-source spatio-temporal LULC data, generate maps with sharpened and detailed land features, characterize the spatial and temporal LULC changes, reveal the trend of LULC change, and create a quality dataset invaluable for monitoring, assessing, and modelling LULC changes
Traffic restrictions during the 2008 Olympic Games reduced urban heat intensity and extent in Beijing
Satellite thermal remote sensing has been utilized to examine the urban heat dynamics in relation to the urban traffic restriction policy. During the 2008 Olympic Games in Beijing, the traffic volume was approximately cut off by half through the road space rationing. Based on daily MODIS satellite thermal observations on the surface temperature, statistical models were developed to analyze the contribution of traffic volume reduction to the urban heat intensity and spatial extent. Our analyses show that cutting off half of the traffic volume has led to a marked decrease in the mean surface temperature by 1.5–2.4 °C and shrinkage of the heat extent by 820 km2 in Beijing. This research suggests that the impact of urban traffic on heat intensity is considerably larger than previously thought, and the management of urban traffic and vehicle fossil fuel use should be included in the future urban heat mitigation plan
Salinity-dependent expression of the branchial Na+/K+/2Cl(-) cotransporter and Na+/K+-ATPase in the sailfin molly correlates with hypoosmoregulatory endurance
In the branchial mitochondrion-rich (MR) cells of euryhaline teleosts, the Na+/K+/2Cl(-)cotransporter (NKCC) is an important membrane protein that maintains the internal Cl -concentration, and the branchial Na+/K+-ATPase (NKA) is crucial for providing the driving force for many other ion-transporting systems. Hence this study used the sailfin molly (Poecilia latipinna), an introduced aquarium fish in Taiwan, to reveal that the potential roles of NKCC and NKA in sailfin molly were correlated to fish survival rates upon salinity challenge. Higher levels of branchial NKCC were found in seawater (SW)-acclimated sailfin molly compared to freshwater (FW)-acclimated individuals. Transfer of the sailfin molly from SW to FW revealed that the expression of the NKCC and NKA proteins in the gills was retained over 7 days in order to maintain hypoosmoregulatory endurance. Meanwhile, their survival rates after transfer to SW varied with the duration of FW-exposure and decreased significantly when the SW-acclimated individuals were acclimated to FW for 21 days. Double immunofluorescence staining showed that in SW-acclimated sailfin molly, NKCC signals were expressed on the basolateral membrane of MR cells, whereas in FW-acclimated molly, they were expressed on the apical membrane. This study illustrated the correlation between the gradual reductions in expression of branchial NKCC and NKA (i.e., the hypoosmoregulatory endurance) and decreasing survival rates after hyperosmotic challenge in sailfin molly
Neutron beam test of CsI crystal for dark matter search
We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear
recoils and 's below 10 keV. The response of CsI crystals to nuclear
recoil was studied with mono-energetic neutrons produced by the
H(p,n)He reaction. This was compared to the response to Compton
electrons scattered by 662 keV -ray. Pulse shape discrimination between
the response to these 's and nuclear recoils was studied, and quality
factors were estimated. The quenching factors for nuclear recoils were derived
for both CsI(Na) and CsI(Tl) crystals.Comment: 21pages, 14figures, submitted to NIM
Steroid-like compounds in Chinese medicines promote blood circulation via inhibition of Na+/K+-ATPase
Aim: To examine if steroid-like compounds found in many Chinese medicinal products conventionally used for the promotion of blood circulation may act as active components via the same molecular mechanism triggered by cardiac glycosides, such as ouabain. Methods: The inhibitory potency of ouabain and the identified steroid-like compounds on Na+/K+-ATPase activity was examined and compared. Molecular modeling was exhibited for the docking of these compounds to Na+/K+-ATPase. Results: All the examined steroid-like compounds displayed more or less inhibition on Na+/K+-ATPase, with bufalin (structurally almost equivalent to ouabain) exhibiting significantly higher inhibitory potency than the others. In the pentacyclic triterpenoids examined, ursolic acid and oleanolic acid were moderate inhibitors of Na+/K+-ATPase, and their inhibitory potency was comparable to that of ginsenoside Rh2. The relatively high inhibitory potency of ursolic acid or oleanolic acid was due to the formation of a hydrogen bond between its carboxyl group and the Ile322 residue in the deep cavity close to two K+ binding sites of Na+/K+-ATPase. Moreover, the drastic difference observed in the inhibitory potency of ouabain, bufalin, ginsenoside Rh2, and pentacyclic triterpenoids is ascribed mainly to the number of hydrogen bonds and partially to the strength of hydrophobic interaction between the compounds and residues around the deep cavity of Na+/K+-ATPase. Conclusion: Steroid-like compounds seem to contribute to therapeutic effects of many cardioactive Chinese medicinal products. Chinese herbs, such as Prunella vulgaris L, rich in ursolic acid, oleanolic acid and their glycoside derivatives may be adequate sources for cardiac therapy via effective inhibition on Na+/K+-ATPase
Active ingredients in Chinese medicines promoting blood circulation as Na+/K+-ATPase inhibitors
The positive inotropic effect of cardiac glycosides lies in their reversible inhibition on the membrane-bound Na+/K+-ATPase in human myocardium. Steroid-like compounds containing a core structure similar to cardiac glycosides are found in many Chinese medicines conventionally used for promoting blood circulation. Some of them are demonstrated to be Na+/K+-ATPase inhibitors and thus putatively responsible for their therapeutic effects via the same molecular mechanism as cardiac glycosides. On the other hand, magnesium lithospermate B of danshen is also proposed to exert its cardiac therapeutic effect by effectively inhibiting Na+/K+-ATPase. Theoretical modeling suggests that the number of hydrogen bonds and the strength of hydrophobic interaction between the effective ingredients of various medicines and residues around the binding pocket of Na+/K+-ATPase are crucial for the inhibitory potency of these active ingredients. Ginsenosides, the active ingredients in ginseng and sanqi, substantially inhibit Na+/K+-ATPase when sugar moieties are attached only to the C-3 position of their steroid-like structure, equivalent to the sugar position in cardiac glycosides. Their inhibitory potency is abolished, however, when sugar moieties are linked to C-6 or C-20 position of the steroid nucleus; presumably, these sugar attachments lead to steric hindrance for the entrance of ginsenosides into the binding pocket of Na+/K+-ATPase. Neuroprotective effects of cardiac glycosides, several steroid-like compounds, and magnesium lithospermate B against ischemic stroke have been accordingly observed in a cortical brain slice-based assay model, and cumulative data support that effective inhibitors of Na+/K+-ATPase in the brain could be potential drugs for the treatment of ischemic stroke
Identification of alpha-enolase as an autoantigen in lung cancer: Its overexpression is associated with clinical outcomes
Purpose: Although existence of humoral immunity has been previously shown in malignant pleural effusions, only a limited number of immunogenic tumor-associated antigens (TAA) have been identified and associated with lung cancer. In this study, we intended to identify more TAAs in pleural effusion-derived tumor cells. Experimental Design: Using morphologically normal lung tissues as a control lysate in Western blotting analyses, 54 tumor samples were screened with autologous effusion antibodies. Biochemical purification and mass spectrometric identification of TAAs were done using established effusion tumor cell lines as antigen sources. We identified a p48 antigen as of-enolase (ENO1). Semiquantitative immunohistochemistry was used to evaluate expression status of ENO1 in the tissue samples of 80 patients with non-small cell lung cancer (NSCLC) and then correlated with clinical variables. Results: Using ENO1-specifc antiserum, up-regulation of ENO1 expression in effusion tumor cells from 11 of 17 patients was clearly observed compared with human normal lung primary epithelial and non-cancer-associated effusion cells. Immunohistochemical studies consistently showed high level of ENO1 expression in all the tumors we have examined thus far. Log-rank and Cox's analyses of ENO1 expression status revealed that its expression level in primary tumors was a key factor contributing to overall- and progression-free survivals of patients (P < 0.05). The same result was also obtained in the early stage of NSCLC patients, showing that tumors expressing relatively higher ENO1 level were tightly correlated with poorer survival outcomes. Conclusions: Our data strongly support a prognostic role of ENO1 in determining tumor malignancy of patients with NSCLC
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