107 research outputs found

    Assessment of Sentinel-2 and Landsat-8 OLI for Small-Scale Inland Water Quality Modeling and Monitoring Based on Handheld Hyperspectral Ground Truthing

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    This study investigates the best available methods for remote monitoring inland small-scale waterbodies, using remote sensing data from both Landsat-8 and Sentinel-2 satellites, utilizing a handheld hyperspectral device for ground truthing. Monitoring was conducted to evaluate water quality indicators: chlorophyll-a (Chl-a), colored dissolved organic matter (CDOM), and turbidity. Ground truthing was performed to select the most suitable atmospheric correction technique (ACT). Several ACT have been tested: dark spectrum fitting (DSF), dark object subtraction (DOS), atmospheric and topographic correction (ATCOR), and exponential extrapolation (EXP). Classical sampling was conducted first; then, the resulting concentrations were compared to those obtained using remote sensing analysis by the above-mentioned ACT. This research revealed that DOS and DSF achieved the best performance (an advantage ranging between 29% and 47%). Further, we demonstrated the appropriateness of the use of Sentinel-2 red and vegetation red edge reciprocal bands (1/(B4 X B6)) for estimating Chl-a (R2 = 0.82, RMSE = 14.52mg/m3). As for Landsat-8, red to near-infrared ratio (B4/B5) produced the best performing model (R2 = 0.71, RMSE = 39.88 mg/m3), but it did not perform as well as Sentinel-2. Regarding turbidity, the best model (with (R2 =0.85, RMSE = 0.87 NTU) obtained by Sentinel-2 utilized a single band (B4), while the best model (with R2 = 0.64, RMSE = 0.90 NTU) using Landsat-8 was performed by applying two bands (B1/B3). Mapping the water quality parameters using the best performance biooptical model showed the significant effect of the adjacent land on the boundary pixels compared to pixels of deeper water

    SARS-CoV-2 infection in acute pancreatitis increases disease severity and 30-day mortality: COVID PAN collaborative study

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    Objective: There is emerging evidence that the pancreas may be a target organ of SARS-CoV-2 infection. This aim of this study was to investigate the outcome of patients with acute pancreatitis (AP) and coexistent SARS-CoV-2 infection. Design: A prospective international multicentre cohort study including consecutive patients admitted with AP during the current pandemic was undertaken. Primary outcome measure was severity of AP. Secondary outcome measures were aetiology of AP, intensive care unit (ICU) admission, length of hospital stay, local complications, acute respiratory distress syndrome (ARDS), persistent organ failure and 30-day mortality. Multilevel logistic regression was used to compare the two groups. Results: 1777 patients with AP were included during the study period from 1 March to 23 July 2020. 149 patients (8.3%) had concomitant SARS-CoV-2 infection. Overall, SARS-CoV-2-positive patients were older male patients and more likely to develop severe AP and ARDS (p<0.001). Unadjusted analysis showed that SARS-CoV-2-positive patients with AP were more likely to require ICU admission (OR 5.21, p<0.001), local complications (OR 2.91, p<0.001), persistent organ failure (OR 7.32, p<0.001), prolonged hospital stay (OR 1.89, p<0.001) and a higher 30-day mortality (OR 6.56, p<0.001). Adjusted analysis showed length of stay (OR 1.32, p<0.001), persistent organ failure (OR 2.77, p<0.003) and 30-day mortality (OR 2.41, p<0.04) were significantly higher in SARS-CoV-2 co-infection. Conclusion: Patients with AP and coexistent SARS-CoV-2 infection are at increased risk of severe AP, worse clinical outcomes, prolonged length of hospital stay and high 30-day mortality

    A Second-Generation Device for Automated Training and Quantitative Behavior Analyses of Molecularly-Tractable Model Organisms

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    A deep understanding of cognitive processes requires functional, quantitative analyses of the steps leading from genetics and the development of nervous system structure to behavior. Molecularly-tractable model systems such as Xenopus laevis and planaria offer an unprecedented opportunity to dissect the mechanisms determining the complex structure of the brain and CNS. A standardized platform that facilitated quantitative analysis of behavior would make a significant impact on evolutionary ethology, neuropharmacology, and cognitive science. While some animal tracking systems exist, the available systems do not allow automated training (feedback to individual subjects in real time, which is necessary for operant conditioning assays). The lack of standardization in the field, and the numerous technical challenges that face the development of a versatile system with the necessary capabilities, comprise a significant barrier keeping molecular developmental biology labs from integrating behavior analysis endpoints into their pharmacological and genetic perturbations. Here we report the development of a second-generation system that is a highly flexible, powerful machine vision and environmental control platform. In order to enable multidisciplinary studies aimed at understanding the roles of genes in brain function and behavior, and aid other laboratories that do not have the facilities to undergo complex engineering development, we describe the device and the problems that it overcomes. We also present sample data using frog tadpoles and flatworms to illustrate its use. Having solved significant engineering challenges in its construction, the resulting design is a relatively inexpensive instrument of wide relevance for several fields, and will accelerate interdisciplinary discovery in pharmacology, neurobiology, regenerative medicine, and cognitive science

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    On the influence of the aliphatic linker on fabrication of highly ordered and orientated self-assembled monolayers of aromatic selenols on AU(111)

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    Self-assembled monolayers (SAMs) formed by adsorption of 1,2-dibenzyldiselenide (DPMSe) and 1,2-diphenyldiselenide (DBSe) on Au(111) substrates at room temperature have been characterized using scanning tunnelling microscopy, X-ray photoelectron spectroscopy, infrared reflection absorption spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and low-energy electron diffraction. Upon adsorption, the Se-Se bonds in DPMSe and DBSe were cleaved on the gold surface to form phenylmethaneselenolate (PMSe) and benzeneselenolate (BSe) species, respectively. Although both PMSe and BSe molecular entities only differ in their structure (an additional methyl group in PMSe), the resulting monolayer films revealed noteworthy dissimilarities regarding their adlayer SAM structure and surface morphology. The molecular adlayer structure and orientation of PMSe and BSe species were found to vary significantly with the immersion time (IT). The resulting PMSe films were poorly organized, and the structure was described by a (4√3 × 2) rectangular unit cell for the SAMs prepared with 24 h of IT. Moreover, the PMSe-SAMs were found to be unstable upon exposure to air for a long time. Our results showed that exposure to air for 48 h results in the formation of small bright ad-islands, which have a height corresponding to that of a single atomic step on the Au(111). Contrary, BSe-SAMs exhibited densely packed and well-ordered monolayers, and two different structural phases were resolved at short and long ITs. The most densely packed structure was obtained for SAMs prepared with very short ITs (10 min). Upon increasing the IT, the SAMs exhibited structural changes to a lower density of molecular packing structure. The spectroscopic data also confirmed this structural transformation by suggesting an upright orientation for BSe-SAMs prepared after short ITs and strongly inclined adsorption geometry for SAMs prepared after long ITs. © 2014 American Chemical Society

    Identification of new inhibitors of Mdm2&ndash;p53 interaction via pharmacophore and structure-based virtual screening

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    Noor Atatreh,1 Mohammad A Ghattas,1 Sanaa K Bardaweel,2 Sara Al Rawashdeh,1 Mohammad Al Sorkhy1 1Department of Pharmaceutical Sciences, College of Pharmacy, Al Ain University of Science and Technology, Al Ain, Abu Dhabi, United Arab Emirates; 2Department of Pharmaceutical Sciences, School of Pharmacy, The University of Jordan, Amman 11942, Jordan Background: The tumor suppressor protein p53 plays an important role in preventing tumor formation and progression through its involvement in cell division control and initiation of apoptosis. Mdm2 protein controls the activity of p53 protein through working as ubiquitin E3 ligase promoting p53 degradation through the proteasome degradation pathway. Inhibitors for Mdm2-p53 interaction have restored the activity of p53 protein and induced cancer fighting properties in the cell.Purpose: The objective of this study is to use computer-aided drug discovery techniques to search for new Mdm2-p53 interaction inhibitors.Methods: A set of pharmacophoric features were created based on a standard Mdm2 inhibitor and this was used to screen a commercial drug-like ligand library; then potential inhibitors were docked and ranked in a multi-step protocol using GLIDE. Top ranked ligands from docking were evaluated for their inhibition activity of Mdm2-p53 interaction using ELISA testing.Results: Several compounds showed inhibition activity at the submicromolar level, which is comparable to the standard inhibitor Nutlin-3a. Furthermore, the discovered inhibitors were evaluated for their anticancer activities against different breast cancer cell lines, and they showed an interesting inhibition pattern.Conclusion: The reported inhibitors can represent a starting point for further SAR studies in the future and can help in the discovery of new anticancer agents. Keywords: protein&ndash;protein interaction, virtual screening, Mdm2, p53, anticancer, docking, pharmacophore, ELIS

    Effect of Treated Wastewater Irrigation on the Accumulation and Transfer of Heavy Metals in Lemon Trees Cultivated in Arid Environment

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    The Middle East is considered as one of the driest regions of the world and the use of municipal-treated wastewater (TWW) for agricultural purposes is needed. The aim of this study was to evaluate the effect of continuous irrigation of TWW in lemon orchards on the accumulation of heavy metals (HMs) in the soil, as well as their uptake and translocation to aerial parts of the trees. For this purpose, two lemon orchards were selected to be irrigated from two different water sources: TWW from a tertiary treatment plant and freshwater (SW) from Moses springs in Jordan. Continuous irrigation with TWW resulted in higher concentrations of nutrients and HM accumulation in the soil as compared to SW. However, HM accumulation in the soil was found to be within the acceptable range according to the standards of the WHO. On the contrary, the continuous irrigation with TWW resulted in the accumulation of HMs in plant parts when compared to SW irrigation; the fruits were clearly affected by the accumulation of high levels of Cd and Pb that exceed the maximum limits for the presence of HMs in plant tissues. The irrigation of lemon trees with TWW had a significant effect on the bioaccumulation factor and translocation factors (TF) of HMs into different lemon tree parts. Heavy metal accumulation coincided with high translocation rates to different tree parts, and this is considered to be a main challenge for long-term irrigation with TWW in arid environments

    Effect of Treated Wastewater Irrigation on the Accumulation and Transfer of Heavy Metals in Lemon Trees Cultivated in Arid Environment

    No full text
    The Middle East is considered as one of the driest regions of the world and the use of municipal-treated wastewater (TWW) for agricultural purposes is needed. The aim of this study was to evaluate the effect of continuous irrigation of TWW in lemon orchards on the accumulation of heavy metals (HMs) in the soil, as well as their uptake and translocation to aerial parts of the trees. For this purpose, two lemon orchards were selected to be irrigated from two different water sources: TWW from a tertiary treatment plant and freshwater (SW) from Moses springs in Jordan. Continuous irrigation with TWW resulted in higher concentrations of nutrients and HM accumulation in the soil as compared to SW. However, HM accumulation in the soil was found to be within the acceptable range according to the standards of the WHO. On the contrary, the continuous irrigation with TWW resulted in the accumulation of HMs in plant parts when compared to SW irrigation; the fruits were clearly affected by the accumulation of high levels of Cd and Pb that exceed the maximum limits for the presence of HMs in plant tissues. The irrigation of lemon trees with TWW had a significant effect on the bioaccumulation factor and translocation factors (TF) of HMs into different lemon tree parts. Heavy metal accumulation coincided with high translocation rates to different tree parts, and this is considered to be a main challenge for long-term irrigation with TWW in arid environments
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