Satellite altimetry for Indian reservoirs

Satellite radar altimetry has immense potential for monitoring fresh surface water resources and predicting the intra-seasonal, seasonal, and inter-annual variability of inundated surface water over large river basins. As part of the Preparation for the Surface Water and Ocean Topography mission scheduled for launch in mid-2022, the present study aimed to evaluate the performance of radar altimetry over the inland water bodies of India. The Joint Altimetry Satellite Oceanography Network (Jason) and Satellite with ARgos and ALtiKa (SARAL/AltiKa) data were used to derive the water levels of 18 major reservoirs in India by incorporating the geophysical and propagation corrections into the radar range. In situ gauge data were used to evaluate the performance of the altimetry-derived water level time series from 2008 to 2019. The results showed a strong correlation between Jason-2 and in situ data with the determination coefficient (R2) and root mean squared error (RMSE) ranging from 0.96 to 0.99 and from 0.28 m to 1.62 m, respectively. The Jason-3 data had the highest correlation with the in situ observation (R2 = 0.99) and the lowest correlation (R2 = 0.82), with RMSE values ranging from 0.11 m to 1.18 m. With an R2 range of 0.93–0.99 and an RMSE range of 0.20–1.05 m, the SARAL/AltiKa mission presented greater accuracy than the Jason altimetry mission. The estimated water levels can be utilized in remote, inaccessible, or ungauged areas and in international transboundary rivers for water storage and river discharge estimations. However, the accuracy of remotely sensed data depends on such factors as along-track distance, water body area, and geographical and terrain conditions near water bodies.publishedVersio

In vitro and in vivo anticancer studies of 2'-hydroxy chalcone derivatives exhibit apoptosis in colon cancer cells by HDAC inhibition and cell cycle arrest

Considering the therapeutic values of bioflavonoids in colon cancer treatment, six 2′-hydroxy chalcones (C1-C6) were synthesized, characterized and screened for in vitro cytotoxicity on human colon carcinoma (HCT116) and African green monkey kidney epithelial cells (Vero). Only C5 showed selective cytotoxicity against HCT116 cells. Other potent cytotoxic compounds were C1, C2 and C3. Further screening included enzyme inhibition studies on histone deacetylase (HDAC) enzyme where C1 showed lowest IC50 value (105.03 µM). Based on cytotoxicity data C1, C2 and C3 were selected for further in vitro mechanistic studies, namely apoptotic studies (Acridine or- ange/Ethidium bromide (AO/EB) and Annexin V), cell cycle analysis using propidium iodide (PI) stain and in vivo anticancer efficacy in 1,2-dimethyl hydrazine (DMH) induced colorectal carcinoma in Wistar rats. The com- pounds induced apoptosis in more than 30 % cells in AO/EB and Annexin V staining. They also showed cell cycle arrest in G2/M phase with PI staining. They showed a significant reduction in aberrant crypt foci formation and adenocarcinoma count along with a significant (p<0.05) reduction in TNF-α levels as compared to DMH control at 100 mg/kg dose. Thus, it can be concluded that the synthesized 2′-hydroxychalcones were effective against colon adenocarcinoma in in vitro and in vivo studies

On Virtual Displacement and Virtual Work in Lagrangian Dynamics

The confusion and ambiguity encountered by students, in understanding virtual displacement and virtual work, is discussed in this article. A definition of virtual displacement is presented that allows one to express them explicitly for holonomic (velocity independent), non-holonomic (velocity dependent), scleronomous (time independent) and rheonomous (time dependent) constraints. It is observed that for holonomic, scleronomous constraints, the virtual displacements are the displacements allowed by the constraints. However, this is not so for a general class of constraints. For simple physical systems, it is shown that, the work done by the constraint forces on virtual displacements is zero. This motivates Lagrange's extension of d'Alembert's principle to system of particles in constrained motion. However a similar zero work principle does not hold for the allowed displacements. It is also demonstrated that d'Alembert's principle of zero virtual work is necessary for the solvability of a constrained mechanical problem. We identify this special class of constraints, physically realized and solvable, as {\it the ideal constraints}. The concept of virtual displacement and the principle of zero virtual work by constraint forces are central to both Lagrange's method of undetermined multipliers, and Lagrange's equations in generalized coordinates.Comment: 12 pages, 10 figures. This article is based on an earlier article physics/0410123. It includes new figures, equations and logical conten

An innovative resident-driven mortality case review curriculum to teach and drive system-based practice improvements in the United States

Purpose Traditionally, the morbidity and mortality conference (M&MC) is a forum where possible medical errors are discussed. Although M&MCs can facilitate identification of opportunities for systemwide improvements, few studies have described their use for this purpose, particularly in residency training programs. This paper describes the use of M&MC case review as a quality improvement activity that teaches system-based practice and can engage residents in improving systems of care. Methods Internal medicine residents at a tertiary care academic medical center reviewed 347 consecutive mortalities from March 2014 to September 2017. The residents used case review worksheets to categorize and track causes of mortality, and then debriefed with a faculty member. Selected cases were then presented at a larger interdepartmental meeting and action items were implemented. Descriptive statistics and thematic analysis were used to analyze the results. Results The residents identified a possible diagnostic mismatch at some point from admission to death in 54.5% of cases (n= 189) and a possible need for improved management in 48.0% of cases. Three possible management failure themes were identified, including failure to plan, failure to communicate, and failure to rescue, which accounted for 21.9%, 10.7 %, and 10.1% of cases, respectively. Following these reviews, quality improvement initiatives proposed by residents led to system-based changes. Conclusion A resident-driven mortality review curriculum can lead to improvements in systems of care. This novel type of curriculum can be used to teach system-based practice. The recruitment of teaching faculty with expertise in quality improvement and mortality case analyses is essential for such a project