207 research outputs found
First person – Varun Jayeshkumar Shah
No full textABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Varun Jayeshkumar Shah is the first author on ‘CRL7SMU1 E3 ligase complex-driven H2B ubiquitination functions in sister chromatid cohesion by regulating SMC1 expression’, published in Journal of Cell Science. Varun is a PhD student in the lab of Dr Subbareddy Maddika at the Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, India, investigating the role of LisH-domain-containing proteins in the assembly of multi-subunit E3 ligase complexes.</jats:p
Estimating the value of demand-side management in low-cost, solar micro-grids
No full textDemand-side management has the potential to reduce the cost of solar based community micro-grids and solar home systems for electricity access. This paper presents a methodology for optimal least-cost sizing of generation assets while meeting explicit reliability constraints in micro-grids that are capable of active demand management. The battery management model considers kinetic constraints on battery operation and represents dispatch in the field to regulate the depth of discharge. The model allows consideration of the trade-off between depth of discharge, cycle life, and calendar lifetime in lead-acid batteries. Separate reliability targets for disaggregated, residential load profiles at hourly timesteps are considered to evaluate the performance and cost reduction potential of demand-side management capabilities — with economic results and sensitivity analyses around key input assumptions subsequently presented. We find that demand-side management can reduce the number and cost of requisite solar panels and batteries with the integration of real-time management and controls – a key result for justifying next generation micro-grids for electricity access. Keywords: Micro-grids, Electricity access, Demand-side management, Reliability, Asset selection, Off-grid, Techno-economic model, CostMassachusetts Institute of Technology. Tata Center for Technology and Desig
A novel PCM1-PDGFRB fusion in a patient with a chronic myeloproliferative neoplasm and an ins(8;5)
No full textSocial rights and economics : claims to health care and education in developing countries
No full textThe author analyzes contemporary rights-based and economic approaches to health care and education in developing countries. He assesses the foundations and uses of social rights in development, outlines an economic approach to improving health and education services, and then highlights the differences, similarities, and the hard questions that the economic critique poses for rights. The author argues that the policy consequences of rights overlap considerably with a modern economic approach. Both the rights-based and the economic approaches are skeptical that electoral politics and de facto market rules provide sufficient accountability for the effective and equitable provision of health and education services, and that further intrasectoral reforms in governance, particularly those that strengthen the hand of service recipients, are needed. There remain differences between the two approaches. Whether procedures for service delivery are ends in themselves, the degree of disaggregation at which outcomes should be assessed, the consequences of long-term deprivation, metrics used for making tradeoffs, and the behavioral distortions that result from subsidies are all areas where the approaches diverge. Even here, however, the differences are not irreconcilable, and advocates of the approaches need not regard each other as antagonists.Health Monitoring&Evaluation,Health Systems Development&Reform,Decentralization,Public Health Promotion,Early Child and Children's Health,Health Monitoring&Evaluation,Health Economics&Finance,Poverty Assessment,Agricultural Knowledge&Information Systems,Gender and Education
Coherency matrices for characterization of vector optical fields
No full textWe describe optical coherency matrices as a generalized method for characterizing the statistical properties of optical fields. We then use this formalism to classify optical fields, in terms of separability, and transfer of entropy between multiple degrees of freedom.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-12-01The student, Varun Ajit Kelkar, accepted the attached license on 2019-07-12 at 20:22.The student, Varun Ajit Kelkar, submitted this Thesis for approval on 2019-07-12 at 20:30.This Thesis was approved for publication on 2019-07-15 at 11:29.DSpace SAF Submission Ingestion Package generated from Vireo submission #14293 on 2020-02-28 at 17:34:54Made available in DSpace on 2020-03-02T22:28:39Z (GMT). No. of bitstreams: 2
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Previous issue date: 2019-07-15Embargo set by: Seth Robbins for item 113953
Lift date: 2022-03-02T22:28:46Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 113953
Lift date: 2022-03-02T22:38:05Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 113953
Lift date: 2022-03-02T22:39:04Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 113953 on 2022-03-03T10:15:30Z
Determination of structural changes and phase transformations in boron carbide by static and dynamic studies
No full textRecent transmission electron microscopy results demonstrate that the failure of B4C is commensurate with the segregation of boron icosahedra embedded in amorphous carbon in 2–3 nm wide amorphous bands along the (113) lattice direction, in good agreement with our recent theoretical results. Boron carbide is generally composed of multiple polytypes of B4C which have the same primitive lattice parameters but differ from each other by the location of the boron and carbon atoms in the unit cells. The unit cells are formed by a 12-atom B12-nCn icosahedron and a 3-atom (C3-nBn) chain. Our theoretical results indicate that one polytype, B12(C3), whose formation is responsible for
the failure of the entire material. This anomalous and poorly understood glass-like behavior in boron carbide has been the subject of research since its discovery over 70 years ago. The characterization of disorder in hot pressed and powder boron carbide samples
is therefore of primary interest. The research work has focused on characterization techniques which can be used at a micrometric sampling size so that individual powder grains of the material can be utilized. Specifically, micro-Raman and electrical
conductivity measurements can be used with micrometric gap cells to understand the disorder in B4C.The results also demonstrate that it is possible to induce transformations in boron carbide using electric fields that are comparable with those obtained under shock and nanoindentation. Our calculations present a hypothesis which can provide a solution to prevent the
premature failure of B4C. A route to achieve suppression of the B12(CCC) polytype without significantly affecting the elastic constants is via low concentration Silicon (Si) doping of B4C. Suppression of B12(CCC) by Si doping has implications towards
development of boron carbide armor with improved properties for protection against high velocity threats. In order to achieve this, nanostructures (nanowires, nanorods, etc.) of Sidoped boron carbide have been synthesized using a Solid-Liquid-Solid (SLS) growth
mechanism. The resulting structures have been characterized by SEM, TEM and Raman
spectroscopy and consolidated to evaluate their mechanical properties. In addition, the application of nanowires in a transparent and thermally conducting nanocomposite is demonstrated.Ph.D.Includes abstractVitaIncludes bibliographical referencesby Varun Gupt
Early and late-onset veno-occlusive disease/sinusoidal syndrome post allogeneic stem cell transplantation – a real-world UK experience
No full textClassical veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a serious complication post allogeneic hematopoietic stem cell transplantation (HSCT). Before the recently revised EBMT criteria, the Baltimore and modified Seattle criteria failed to recognize the syndrome of late-onset VOD. We present real-world experience from a large UK transplant center reporting on VOD/SOS in consecutive HSCT adult patients (n = 530), transplanted for hematological cancers. We identified 27 patients treated with Defibrotide for VOD/SOS diagnosis, where detailed data were available for final analysis. Using standard definitions including EBMT criteria, around 30% (n = 8/27) of cases classified as late-onset VOD presenting at median of 46 (22-93) days but with D100 survival (63% vs 58%, Log-rank; P = 0.81) comparable to classical VOD. Hazard ratio for D100 mortality was 2.82 (95% CI: 1.74-4.56, P <.001, Gray test) with all VOD/SOS events. Twenty percent (n = 2/8) of late-onset VOD patients were anicteric and 42% (n = 8) classical VOD patients presented with refractory thrombocytopenia, while less than half met EBMT criteria for classical VOD in adults, highlighting gaps in real-world diagnostic limitations using EBMT criteria. However, challenges remain about underrecognition and difficulties related to early defibrotide access for treatment of late-onset VOD in current treatment guidelines. Our report strongly supports early Defibrotide for the treatment of severe VOD/SOS in adults regardless of time of onset.</p
Optimal sizing of solar and battery assets in decentralized micro-grids with demand-side management
No full textThesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, Technology and Policy Program, 2017.Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.Cataloged from PDF version of thesis.Includes bibliographical references (pages 199-209).Solar-based community micro-grids and individual home systems have been recognized as key enablers of electricity provision to the over one billion people living without energy access to-date. Despite significant cost reductions in solar panels, these options can still be cost-prohibitive mainly due over-sizing of generation assets corresponding with a lack of ability to actively manage electricity demand. The main contribution shared is the methodology and optimization approach of least-cost combinations of generation asset sizes, in solar panels and batteries, subject to meeting reliability constraints; these results are based on a techno-economic modeling approach constructed for assessing decentralized micro-grids with demand-side management capabilities. The software model constructed is implemented to represent the technical characteristics of a low-voltage, direct current network architecture and computational capabilities of a power management device. The main use-case of the model presented is based on serving representative, aggregated, household-level load profiles combined with simulated power output from solar photovoltaic modules and the kinetic operating constraints of lead-acid batteries at hourly timesteps over year-long simulations. The state-space for solutions is based on available solar module and battery capacities from distributors in Jharkhand, India. Additional work presented also extends to real-time operation of such isolated micro-grids with requisite local computation. First, for load disaggregation and forecasting purposes, clustering algorithms and statistical learning techniques are applied on quantitative results from inferred load profiles based on data logged from off-grid solar home systems. Second, results from an optimization approach to accurately parametrize a lead-acid battery model for potential usage in real-time field implementation are also shared. Economic results, sensitivity analyses around key technical and financial input assumptions, and comparisons in cost reductions due to the optimization of solar and battery assets for decentralized micro-grids with demand-side management capabilities are subsequently presented. The work concludes with insights and policy implications on establishing differentiated willingness-to-pay, tiers of service, and dynamic price-setting in advanced micro-grids.by Varun Mehra.S.M. in Technology and PolicyS.M
The Need for Continued Innovation in Solar, Wind, and Energy Storage
No full textVarun Sivaram is the Philip D. Reed fellow for science and technology at the Council on Foreign Relations. He is also an adjunct professor at Georgetown University, an adjunct senior research scholar at Columbia University, and a member of the energy and environment advisory boards at Stanford University. He is the author of the book, Taming the Sun: Innovations to Harness Solar Energy and Power the Planet (MIT University Press, 2018) and the editor of the book, Digital Decarbonization: Promoting Clean Energy Systems Through Digital Innovations (CFR Press, 2018). Forbes named him one of its 30 under 30 in law and policy, and Grist named him one of the top 50 leaders in sustainability
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