Ram Kumar - Academia.edu (original) (raw)

Papers by Ram Kumar

Water

Given the omnipresence and potential of entering the food web, the recently emerged pollutant mic... more Given the omnipresence and potential of entering the food web, the recently emerged pollutant microplastics (MPs) has become a global threat. The impacts of MPs in marine ecosystems are well documented, but the freshwater environment is relatively understudied. Improper disposal of industrial and commercial waste introduces MPs in the freshwater environment where it is either transported to the ocean or eventually settles down to the bottom. To elicit the impacts on components of fitness, the effect of inert particles on the reproductive and behavioral performance on organisms can only be translated after long-term experiments, but most of the available information on freshwater benthos relies only on short-term experiments. This study investigated the rates of microplastic ingestion, locomotion and reproduction in the globally invasive snail Physa acuta (Gastropoda, Pulmonata) at six environmental concentrations (0, 2.5, 5, 10, 20 and 40 mg/200 mL) of polystyrene (PS) MPs particle ...

arXiv (Cornell University), Oct 25, 2018

When machine learning systems fail because of adversarial manipulation, how should society expect... more When machine learning systems fail because of adversarial manipulation, how should society expect the law to respond? Through scenarios grounded in adversarial ML literature, we explore how some aspects of computer crime, copyright, and tort law interface with perturbation, poisoning, model stealing and model inversion attacks to show how some attacks are more likely to result in liability than others. We end with a call for action to ML researchers to invest in transparent benchmarks of attacks and defenses; architect ML systems with forensics in mind and finally, think more about adversarial machine learning in the context of civil liberties. The paper is targeted towards ML researchers who have no legal background.

Colonisation of crustacean zooplankton with ciliate epibionts is widespread in freshwater and mar... more Colonisation of crustacean zooplankton with ciliate epibionts is widespread in freshwater and marine environments. However, the ecology of such association are little studied as yet. The occurrence of ciliate epibionts on copepods and the preference towards this association with different life stages of Mesocyclops were studied from winter to spring. Relative susceptibility of zooplankton species was evaluated by analysing the epibiont colonies and zooids and relate this to the surface area of the host. The maximum epibiont infestation was recorded on copepodites followed by copepod adults rather than other zooplankton species, whereas the rotifer Asplanchna was never affected. Influence of climatic factors such as temperature on the colonisation of epibionts on basibionts was found significant. In winter (November to February) samples, copepods were infested by autotrophic epibionts whereas in late spring and early summer (March-April) heterotrophic protists (peritrichian ciliates)...

Journal of Energy Resources Technology

Geological sequestration of carbon dioxide (CO2) in deep saline aquifers is one of the most promi... more Geological sequestration of carbon dioxide (CO2) in deep saline aquifers is one of the most promising technologies for large-scale CO2 mitigation. Temperature can play a significant role in the ensuing geochemistry, affecting equilibria in a multicomponent system and impacting reactive transport processes. The objectives of this study are to quantify the effect of temperature on storage efficiency, solubility trapping of CO2, pH of residual brine, and changes in the mineralogy and porosity. Using toughreact 3.3 (a reactive transport simulator), we have simulated the injection of CO2 into a heterogeneous layered carbonate formation for a period of 50 years, followed by a 50-year equilibration period with no injection. Mineralogy and physical properties of the simulated aquifer are based on a dolomitic limestone aquifer located within the South Florida Basin. Simulations were conducted for seven values of temperature. Density of supercritical CO2 decreases with an increase in temperat...

ArXiv, 2021

Attacks from adversarial machine learning (ML) have the potential to be used "for good"... more Attacks from adversarial machine learning (ML) have the potential to be used "for good": they can be used to run counter to the existing power structures within ML, creating breathing space for those who would otherwise be the targets of surveillance and control. But most research on adversarial ML has not engaged in developing tools for resistance against ML systems. Why? In this paper, we review the broader impact statements that adversarial ML researchers wrote as part of their NeurIPS 2020 papers and assess the assumptions that authors have about the goals of their work. We also collect information about how authors view their work's impact more generally. We find that most adversarial ML researchers at NeurIPS hold two fundamental assumptions that will make it difficult for them to consider socially beneficial uses of attacks: (1) it is desirable to make systems robust, independent of context, and (2) attackers of systems are normatively bad and defenders of syste...

This paper presents simulation and hardware implementation of single phase grid tied photovoltaic... more This paper presents simulation and hardware implementation of single phase grid tied photovoltaic system. A grid tied PV system is one in which solar power system is connected to the load & power grid. This enables us to sell surplus energy to the electricity board.Compared to the traditional energy resources, photovoltaic (PV) system that uses the solar energy toproduce electricity considered as one of renewable energies has a great potential and developing increasingly fast compared to its counterparts of renewable energies. Such systems can be either stand-alone or connected to utility grid. However, the disadvantage is that PV generation depended on weather conditions.

Frontiers in Oncology, 2021

The lack of traditional cancer treatments has resulted in an increased need for new clinical tech... more The lack of traditional cancer treatments has resulted in an increased need for new clinical techniques. Standard two-dimensional (2D) models used to validate drug efficacy and screening have a low in vitro-in vivo translation potential. Recreating the in vivo tumor microenvironment at the three-dimensional (3D) level is essential to resolve these limitations in the 2D culture and improve therapy results. The physical and mechanical environments of 3D culture allow cancer cells to expand in a heterogeneous manner, adopt different phenotypes, gene and protein profiles, and develop metastatic potential and drug resistance similar to human tumors. The current application of 3D scaffold culture systems based on synthetic polymers or selected extracellular matrix components promotes signalling, survival, and cancer cell proliferation. This review will focus on the recent advancement of numerous 3D-based scaffold models for cancer tissue engineering, which will increase the predictive abi...

Plants, 2020

The aquatic plants, Azolla filiculoides, and Landoltia punctate, were used as complementing phyto... more The aquatic plants, Azolla filiculoides, and Landoltia punctate, were used as complementing phytoremediators of wastewater containing high levels of phosphate, which simulates the effluents from textile, dyeing, and laundry detergent industries. Their complementarities are based on differences in capacities to uptake nitrogen and phosphate components from wastewater. Sequential treatment by L. punctata followed by A. filiculoides led to complete removal of NH4, NO3, and up to 93% reduction of PO4. In experiments where L. punctata treatment was followed by fresh L. punctata, PO4 concentration was reduced by 65%. The toxicity of wastewater assessed by shrimps, Paratya australiensis, showed a four-fold reduction of their mortality (LC50 value) after treatment. Collected dry biomass was used as an alternative carbon source for heterotrophic marine protists, thraustochytrids, which produced up to 35% dry weight of lipids rich in palmitic acid (50% of total fatty acids), the key fatty aci...

Barbastella, 2019

Myanmar and Sri Lanka (Molur et al. 2008). Individuals of P. giganteus live gregariously in well-... more Myanmar and Sri Lanka (Molur et al. 2008). Individuals of P. giganteus live gregariously in well-exposed large trees, and camp size ranges from a few hundred to many thousands (Eby 1991, Parry-Jones & Augee 1992, Markus & Blackshaw 2002). Day roosts offer a site for courtship, social activity and mother-infant interaction (Markus & Blackshaw 2002). These exchanges among individuals influence group social structure and mating systems (Kunz & Lumsden 2003). Marimuthu (1988) reported that P. giganteus is considered as sacred species within a few villages across southern and northern India. Flying foxes are eco-enhancers that effectively improve the ecosystem by seed dispersal and pollination services (Fujita & Tuttle 1991). They play a vital role in seed dispersal by retaining viable seeds in their guts during different foraging flights and defecate while returning to their diurnal roosts (Shilton et al. 1999). However, they face a number of anthropogenic threats, of which hunting for bushmeat and felling of roost trees are the major contributors (Neupane et al. 2016).

Developmental Cell, 2018

Highlights d Loss of Hippo pathway LATS kinase leads to YAP/TAZ-driven global hypertranscription ... more Highlights d Loss of Hippo pathway LATS kinase leads to YAP/TAZ-driven global hypertranscription d YAP/TAZ-driven hypertranscription upregulates many growth and proliferation genes d Hypertranscription impairs neural progenitor differentiation and causes apoptosis d Cell-number-normalized methods are required to detect global hypertranscription

Development (Cambridge, England), Jan 10, 2018

Early mammalian development is critically dependent on the establishment of oxidative energy meta... more Early mammalian development is critically dependent on the establishment of oxidative energy metabolism within the trophectoderm (TE) lineage. Unlike inner cell mass (ICM), TE cells enhance ATP production via mitochondrial oxidative phosphorylation (OXPHOS) and this metabolic preference is essential for blastocyst maturation. However, molecular mechanisms that regulate establishment of oxidative energy metabolism in TE cells are incompletely understood. Here, we show that conserved transcription factor TEAD4, which is essential for pre-implantation mammalian development, regulates this process by promoting mitochondrial transcription. In the developing TE and TE-derived trophoblast stem cells (TSCs), TEAD4 localizes to mitochondria, binds to mitochondrial DNA (mtDNA) and facilitates mtDNA transcription by recruiting mitochondrial RNA Polymerase (POLRMT). Loss of TEAD4 impairs recruitment of POLRMT, resulting in reduced expression of mtDNA-encoded electron transport chain components,...

Limnology and Oceanography, 2017

The salinity gradient of estuaries plays a unique and fundamental role in structuring spatial pat... more The salinity gradient of estuaries plays a unique and fundamental role in structuring spatial patterns of physical properties, biota, and biogeochemical processes. We use variability along the salinity gradient of San Francisco Bay to illustrate some lessons about the diversity of spatial structures in estuaries and their variability over time. Spatial patterns of dissolved constituents (e.g., silicate) can be linear or nonlinear, depending on the relative importance of river-ocean mixing and internal sinks (diatom uptake). Particles have different spatial patterns because they accumulate in estuarine turbidity maxima formed by the combination of sinking and estuarine circulation. Some constituents have weak or no mean spatial structure along the salinity gradient, reflecting spatially distributed sources along the estuary (nitrate) or atmospheric exchanges that buffer spatial variability of ecosystem metabolism (dissolved oxygen). The density difference between freshwater and seawater establishes stratification in estuaries stronger than the thermal stratification of lakes and oceans. Stratification is strongest around the center of the salinity gradient and when river discharge is high. Spatial distributions of motile organisms are shaped by species-specific adaptations to different salinity ranges (shrimp) and by behavioral responses to environmental variability (northern anchovy). Estuarine spatial patterns change over time scales of events (intrusions of upwelled ocean water), seasons (river inflow), years (annual weather anomalies), and between eras separated by ecosystem disturbances (a species introduction). Each of these lessons is a piece in the puzzle of how estuarine ecosystems are structured and how they differ from the river and ocean ecosystems they bridge.

Development (Cambridge, England), Mar 23, 2017

GATA transcription factors are implicated in establishing cell fate during mammalian development.... more GATA transcription factors are implicated in establishing cell fate during mammalian development. In early mammalian embryos, GATA3 is selectively expressed in the extraembryonic trophoblast lineage and regulates gene expression to promote trophoblast fate. However, trophoblast-specific GATA3 function is dispensable for early mammalian development. Here, using dual conditional knockout mice, we show that genetic redundancy of GATA3 with paralog GATA2 in trophoblast progenitors ensures the successful progression of both pre and postimplantation mammalian development. Stage-specific gene deletion in trophoblasts reveals that loss of both GATA genes, but not either one alone, leads to embryonic lethality prior to the onset of their expression within the embryo proper. Using ChIP-seq and RNA-seq analyses, we define the global targets of GATA2/GATA3 and show that they directly regulate a large number of common genes to orchestrate stem vs. differentiated trophoblast fate. Also, in tropho...

Asian Journal of Multidisciplinary Studies, Mar 28, 2014

India is considered as one of the booming economies in the world, which provides tremendous chanc... more India is considered as one of the booming economies in the world, which provides tremendous chances for global corporations. The global brands have gained a bee line to the market in India to seize a market share in the growing pie. In today"s scenario brands are the basis of consumer relationship. Global brand is a product that adds other dimensions that differentiate it in some way from other products designed to satisfy the same need. Globalization is inevitable which has led the entire world to become a market, a global village. Not only has globalization made the world become a real single universal community containing people from various cultures, but also it has aided greatly in the exchange of services and goods, knowledge and information by reducing the international barriers, thus leading to the shrinkage of the world. This study examines consumer perception of global brands in India. Consumer brand perceptions have substantial implications inMarketing. The study explores and understands consumer perceptions of global brands in India by accomplishing the secondary objectives.. A global brand should provide relevant meaning and experience to people across multiple societies. The perception of quality that is associated with the global brands is difficult to unlock but it"s easier to create a blue ocean of opportunities for Indian brands.

Developmental medicine and child neurology, Jan 12, 2015

pallidum), a typical finding of GMI following HIE; together with thalamus involvement it was repo... more pallidum), a typical finding of GMI following HIE; together with thalamus involvement it was reported in 59% of scans. But it may be difficult to discriminate between putamen and pallidum involvement, when the latter may be minimal. Especially when the MRI has been performed in the first year, the identification of involvement may be difficult. There is not much data on the evolution of signal changes in the deep nuclei following HIE and also kernicterus. In both situations signal changes are seen best on T1w in the neonatal period, 5 whereas later on (as given in Reid et al. 4) on T2w images. But the transitional period is unclear (which unfortunately is not dealt with in this study), where MRI was included from an age of 6 months onwards. With respect to clinical outcome, two other observations seem worth mentioning as they confirm what is clinically expected so that counselling can be done on a broader data basis: First, non-spastic motor types of CP were mainly seen when deep nuclei including pallidum were affected, but predominantly where cortico-subcortical injury was not extensive. Secondly, the likelihood of epilepsy was highest in the context of generalized cortico-subcortical involvement and white matter loss, including the hippocampus and temporal lobes. Taken together, this paper certainly adds important information for the understanding of GMI and its relationship to clinical outcome.

Strength assessment of bridges is an important activity in the Bridge Management process. Various... more Strength assessment of bridges is an important activity in the Bridge Management process. Various aspects related to assessment of current strength as well as in future are discussed. Methodology suggested by IRC is also discussed with the help of a case study. The discussion would provide to adopt appropriate methodology for assessment of load carrying capacity of the bridge(s) for the purpose of Bridge Management System suitable to Indian conditions. INTRODUCTION

Mater. Horiz., 2014

It has been possible to bestow significantly improved mechanical properties on a porous MOF by in... more It has been possible to bestow significantly improved mechanical properties on a porous MOF by incorporating BN nanosheets.

Amino Acids, 2015

The biophysical characteristics of the mutated proteins were determined by size-exclusion HPLC, f... more The biophysical characteristics of the mutated proteins were determined by size-exclusion HPLC, far-UV circular dichroism and fluorescence studies. Far-UV circular dichroism spectral analysis displayed slight modifications in β-sheet of R54C mutant. Altered intrinsic tryptophan fluorescence and decreased bis-ANS fluorescence were observed in all the N-terminal mutations revealing the tertiary structural changes and decreased exposure of surface hydrophobicity. An emphatic fall in the chaperone activity was observed in the N-terminal mutants, R12C, R21L and R54C. QCM analysis revealed the occurrence of strong heterogeneous interaction between αA-crystallin and αB-crystallin. Nevertheless, decreased interactions were observed with the N-terminal mutants. In summary, the present study concludes that the loss of interactions between αA-crystallin N-terminal mutants and αB-crystallin signifies quaternary structural alterations due to mutation in the arginine residues.

2008 IEEE Conference on Computer Vision and Pattern Recognition, 2008

Calibrating a network of cameras with non-overlapping views is an important and challenging probl... more Calibrating a network of cameras with non-overlapping views is an important and challenging problem in computer vision. In this paper, we present a novel technique for camera calibration using a planar mirror. We overcome the need for all cameras to see a common calibration object directly by allowing them to see it through a mirror. We use the fact that the mirrored views generate a family of mirrored camera poses that uniquely describe the real camera pose. Our method consists of the following two steps: (1) using standard calibration methods to find the internal and external parameters of a set of mirrored camera poses, (2) estimating the external parameters of the real cameras from their mirrored poses by formulating constraints between them. We demonstrate our method on real and synthetic data for camera clusters with small overlap between the views and non-overlapping views.

Journal of medical case reports, Jan 9, 2007

Acute encephalomyelopathy occurring after an allogeneic bone marrow transplant for leukaemia is a... more Acute encephalomyelopathy occurring after an allogeneic bone marrow transplant for leukaemia is a diagnostic emergency. The diagnosis can be challenging since there is a wide set of alternative diagnoses, including opportunistic infections and relapse of the leukaemia. A 13-year old girl presented with a severe acute myelopathy and encephalopathy. She was in prolonged remission from a central nervous system and bone marrow relapse of an acute lymphoblastic leukaemia, treated with allogeneic bone marrow transplantation. Neuroimaging showed multifocal grey and white matter lesions of demyelinating appearance in the brain and entire spine. Immunophenotyping and cytogenetic investigations of the girl's cerebrospinal fluid lymphocytosis excluded a late central nervous system relapse of her leukaemia. The diagnosis was acute disseminated encephalomyelitis. With standard immunosuppressive therapy, the girl had early cerebral recovery but a prolonged period of recovery from her myelopat...