Conference Papers and Abstracts

Table of Contents:
(ISBN 978-976-620-299-6)

To cite an Abstract or Full Paper the following example may help:
Ventura, A.K. and Wint, S.M.E. (2018),
"Can Caribbean Countries Ignore Scientific and Technological Knowledge and Still Prosper?"
Proceedings of The 21st CAS General Meeting and Conference on
"Science, Technology and Innovation - Vehicles for a Knowledge Based Economy",
Mona Visitors' Lodge and Conference Centre, Kingston, Jamaica, West Indies,
27-30 November 2018 (ISBN 978-976-620-299-6) Ref.CAS-006, pp.28-36





CAS-001: The Central Challenge for Caribbean Scientists, Engineers, Technologists and Economic Planners

Winston H.E. Suite


CAS-002: On a Stochastic Differential Equation with Gamma-Distributed Jumps

Jasmine Cesars, Silvere P. Nuiro and Jean Vaillant


CAS-003: Integrating Global Biomedical Sciences for Health Research in the Caribbean: The University of the West Indies and State University of New York Health Research Task Force

John F. Lindo,; Jeffrey C. Lombardo, Terrence Forrester, Horace Fletcher, Tomlin Paul, Gina Prescott, Alison Nicholson, Andrew H. Talal, Sanjay Sethi, Brian Tsuji, Venu Govindaraju,

Karen Phillips, Tyler Mullen, Jack DeHovitz, and Gene D. Morse


CAS-004: SEM/EDAX Studies on Consolidated Volcanic Soils and Crystalline Rocks Indicating the Strong Presence of Rare Earth and Rare Elements in the Caribbean Island of Grenada

Ramsey Saunders, Leon Radix, and David Hinds


CAS-005: A Story of the Accidental Formation of Novel Titanium(IV) Schiff Base Salen Complexes

Alvin A. Holder, Raj K. Gurung, William L. Jarrett, and Colin, McMillen


CAS-006: Can Caribbean Countries Ignore Scientific and Technological Knowledge and Still Prosper?

Arnoldo K. Ventura and Sandra M. E. Wint


CAS-007: Lightsources for Africa, the Americas, Asia and Middle East Project (LAAAMP): An IUPAP and IUCr ICSU-Funded Project

Sekazi K. Mtingwa


CAS-008: A Survey of Knowledge Management Practices in Trinidad and Tobago Manufacturing Enterprises: Highlights of Findings

Man Yin Rebecca Yiu and Kit Fai Pun


CAS-009: Building Local Skills to Compete in a Global Economy: The Use of a Formal Apprenticeship Programme in the Bahamas

Robert W. Robertson


CAS-010: Solving Multi-Objective Economic Dispatch Problems Incorporating Wind Units Using a Semi-definite Programming Approach

Kolapo Sulaimon Alli; Abimbola Muideen Jubril and Lawrence O. Kehinde




CAS-011: Geoheritage and the Conservation of Natural Geological Sites of Interest in Guadeloupe, French West Indies

Yves Mazabraud


CAS-012: 30 Years of JCAMP-DX Formats and Still Going Strong

Antony N. Davies and Robert J. Lancashire


CAS-013: Some Notable Scientists of Colonial Jamaica

Robert J. Lancashire


CAS-014: Temperature Effect on the Cracking Healing Potential of Asphalt Concrete Mixes

Lee P. Leon, Rico Nurse, and Shannon Noel


CAS-015: Multi-stage Extraction and Purification of Waste Sargassum Natans to Produce Sodium Alginate: An Optimiisation Approach

Akeem Mohammed, Rakesh Bissoon, Elisheba Bajnath, Kristy Mohammed, Therese Lee, Meera Bissram, Nigel John, Nigel K. Jalsa, Koon Yang-lee, and Keeran Ward


CAS-016: Fabrication of Calcium Alginate Thin Films from Sargassum Natans for the Adsorption of Heavy Metal Ions from Waste Water

Chantal Mohammed, Shivanie Mahabir, Kristy Mohammed, Nigel John, Koon Yang-lee, and Keeran Ward


CAS-017: Process Simulation and Energy Analysis of Carbon Dioxide Removal from the Ammonia process

Therese G. Lee and Keeran Ward


CAS-018: Anatomy and Histology of the Digestive Tract of the Cocrico (Oratalis ruficauda)

Venkatesan Sundaram, Chantal Perryman, Kern Johnson, Avinash Lodie, Clive Folkes, and Andrew A. Adogwa


CAS-019: Potential Use of Tropical Landfill Leachate in Manufacturing Portland Cement Concrete

Samantha Jagmohan, Abrahams Mwasha and Winston Mellowes


CAS-020: How Returns Differ by Field of Study in Trinidad and Tobago

Roshnie Doon




CAS-021: Activated Charcoal Promotes Surgical Wound Healing Effects of Musa sapientum and Citrus Limon Peel Gel in Rattus novergicus

James Omale


CAS-022: Mechanistic Aspects of the Aerobic Copper-catalyzed Decarboxylative Thiolation of Benzoic Acids

Kerry-Ann Green and Jessica M. Hoover


CAS-023: An Assessment of Host-plant Preference of Aphis gossypii in Jamaica

Desireina D.S. Delancy, Tannice A. Hall and Eric Garraway


CAS-024: The Efficacy of Sulphur/Insecticide Treatments for Franlinella Occidentallis (Western Flower Thrips) under Protected Cultivated in Jamaica

St. Sanya G.L. Morrison, Camille C. Marks Kelly, Michelle A. Sherwood, Michael Pryce and Sheldon Elliott


CAS-025: Evaluation of Isomate- Baw Mating Disruption Technology for the Management of Beet Armyworm (Spodoptera Exigua) in Scallion/Welsh Onion (Allium Fistulosum) in Todd Town, St. Elizabeth Jamaica

Michelle A. Sherwood, Marina Young, Francine Webb-Lawrence, and Michael Pryce


CAS-026: Evaluation of UV-absorbing Film for Management of Western Flower Thrips under Protected Cultivated in Jamaica

St. Sanya G.L. Morrison, Camille C. Marks Kelly, Michelle Sherwood, Michael Pryce and Sheldon Elliott


CAS-027: Evaluation of New Irish Potato (Solanum tuberosum L.) Varieties for High Yield Potential, Late Blight Tolerance and Market Suitability in Jamaica

Michelle A. Sherwood, Michael Pryce, Lisa R. Myers Morgan, Carla Douglas, Alexi Reid, Patrice Pitter, and Christopher A. Haughton


CAS-028: The Efficacy of Baculovirus Bio-Pesticides in the Management of Beet Armyworm, Spodoptera Exigua (Hubner) in Scallion, Allium Fistulosum L. in Jamaica

Christopher A. Haughton, Michelle A. Sherwood, Francine Webb-Lawrence, and Dwayne Henry


CAS-029: A Point Prevalence Survey of Health Associated Infections and Antimicrobial Use in a Public Health Institution in Trinidad

Shinelle C. Francois, Patricia Sealy and George Legall


CAS-030: Mild Steel Corrosion Inhibition in Acidic Medium by Theobroma Cacao Pod Extracts

Annacia K. Jeffers and Ann M. Wilson




CAS-031: An Environmentally Friendly Solution to Realising ICT Sector Growth in Developing Countries

Brandon O. Campbell, Kaycilee S. Wright, and Louis-Ray O. Harris


CAS-032: A Newly Modified QuEChERS Method for the Analysis of Pesticide Residues in Select Fruit and Vegetable Matrices in Trinidad and Tobago

Winnette A. Collimore and Grace-Anne E. Bent


CAS-033: A Systems-oriented Vulnerability Approach to Flooding in Cave, Westmoreland, Jamaica

Tracy-Ann N. Hyman


CAS-034: Transition-Metal Catalysis for the Production of Active Pharmaceutical Ingredients

Kadane O. Morris, Paul T. Maragh, Tara P. Dasgupta and Kamaluddin Abdur-Rashid


CAS-035: Entropy Analysis of Heart Rate Variability of Adult Human Diabetics and Non-diabetics Before, During and After Mild Exercise

Michelle Amoroso


CAS-036: Effect of 150kHz Electromagnetic Radiation on Polycystic Ovary Development (Rat Model)

Stephanie Mohammed, Nikolay Zyzuikov, Shivananda Nayak, and Venkatesan Sundaram


CAS-037: Design of a Practical, Cost-effective Real-time Surveillance System for Leptospirosis in Trinidad and Tobago

Lisa A. Benjamin


CAS-038: Chiral Transition Metal Diphosphine Complexes and Their Applications in Asymmetric Catalysis

Shannen C. Lorraine, Paul T. Maragh, Tara P. Dasgupta, and Kamaluddin Abdur-Rashid


CAS-039: Theoretical Study of the Interaction of Two Chloride Pesticides with Superficial Amines of Activated Carbon

Kenia Melchor-Rodriguez, Chayan Carmenate-Rodriguez, Juan J. Gamboa-Carballo, Nady Passe-Coutrin, Sarra Gaspard and Ulises. J. Jauregui-Haza


CAS-040: Depollution of Waters Contaminated with Chlordecone and β -hexachlorocyclohexane by their Precipation with Cyclodextrins

Juan J. Gamboa-Carballo, A. Ferino-Perez, Vijay K. Rana, Kenia Melchor-Rodriguez,Ronald Ranguin, Joelle Levallois-Grutzmacher, Sarra Gaspard, and Ulises. J. Jauregui-Haza




CAS-041: Using Gamma Radiation for Degradation of Diazepam, Midazolam and Flumazenil in Wastewaters

Michel Manduca-Artiles, Susana Gomez-Gonzalez, Claudia Marchan-Moreno, Maria Gonzalez-Marin, Sarra Gaspard, and Ulises Jauregui-Haza


CAS-042: A Cost-effective Virtual Reality Headset for Immersive Interactive Learning in Developing Nations

Kaycilee S. Wright, Brandon O. Campbell and Louis-Ray O. Harris


CAS-043: PET Technology: An Opportunity for Innovation in Radiopharmacy and Nuclear Medicine in the Caribbean

Lyonel Belia, Caroline Faes, and Ulises. J. Jáuregui-Haza


CAS-044: Catalytic Conversion of Carbon Dioxide to Methanol and Chemical Hydrogen Storage

Kareem Abdur-Rashid, Wenli Jia and Kamaluddin Abdur-Rashid


CAS-045: The Effects of Wall Thickness and Raster Resolution on the Diametric Accurancy, Cylindricity, and Concentricity of Fused Deposition Modelled Sacrificial Patterns

Winston Sealy


CAS-046: Removal of 2-Nitrophenol, 2, 4-Dinitrophenal and 2, 4, 6-Trinitrophenol from Aqueous Solution Through Adsorption on Cobalt, Nickel and Tungsten Ferrocyanides

Tricia Grant and Brij B. Tewari  


CAS-047: Chiral Ruthenium Aminophospine and Phosphine Iminopyridine Complexes for Asymmetric Catalytic Transformations

Littlelet N. Scarlet-Banks, Kamaluddin Abdur-Rashid, Paul T. Maragh, and Tara Dasgupta


CAS-048: Characterisation of Trace Elements and Organic Compounds in Kingston, Jamaica

Dwight Messam, Novelette Sadler-Mcknight, Michael Coley and Johan Boman


CAS-049: The Fatigue Resistance of RAP in Asphalt Concrete Mixes Using Two Different Binders

Lee P. Leon, Trevor Townsend, and Dale Diaz


CAS-050: Chemical Structure Investigation of Nutmeg (Myristica Fragrans) Shells and its Derived Carbon Sorbents and the Process Conditions for Producing Such Sorbents

Crispin R. Andrews, Reginald Pantin, Ronald Ranguin, Christelle Yacou, Jeffrey V. Smith, and Sarra Gaspard  




CAS-051: PM2.5 and Gaseous Pollution at an Industrial Site in Kingston, Jamaica

Johan Boman, Willard Pinnock, Samuel M. Gaita, Novelette McKnight, and Carlos Mingoes


CAS-052: Pincer Ligands Based on Pyridylcarbo(thio)amides Backbones as Effective Ancillary Ligands in Electro- and Homogeneous-catalysis

Mark A.W. Lawrence


CAS-053: Advancing the Caribbean Energy Landscape - A Comprehensive Review of the State of Electric Vehicles and Storage Systems

Masao I. Ashtine, Randy Koon Koon, Delando Grant and Anila Maharaj


CAS-054: Residual Levels of Furan in Some Caribbean Foods Using Headspace Gas Chromatograph Mass Spectrometer (HS/GC-MS)

Samantha R. Brown-Dewar, Tara P. Dasgupta, and Paul T. Maragh


CAS-055: Assessing the Potential Impacts of Increasing Temperatures on Asphalt Binder Performance

Lee P. Leon; and Kellesia Williams-Gittens


CAS-056: Effect of Sample Mass on Particle Size Distribution in Predominantly Medium to Heavy Textured Tropical Soils

Mark N. Wuddivira, De Shorn E. Bramble, Gregory A. Gouveia and Ananda Ramlochan


CAS-057: Morphology of Third Instar Larvae of Three Species of Flies (Family: Sarcophagidae) of Potential Forensic Importance in Jamaica

Rochelle S.H. Daley, Eric Garraway, and Catherine Murphy


CAS-058: On Well-Posedness of a Non-linear Degenerate DiRICHLET Problem with Very Irregular Data


Silvere P. Nuiro

CAS-059: Assessment of Temporal Rainfall Distribution in Trinidad and Tobago Using the Annual and Seasonal Precipitation Concentration Indices

Reynold J. Stone


CAS-060: Temperature Effects on the Relative Stability of Ultra-High-Pressure Phases of Oxygen

Beatriz H. Cogollo-Olivo; Sandro Scandolo, Sananda Biswas, and Javier A. Montoya




CAS-061: Solving Stochastic Multi-Objective Economic Dispatch Problems Incorporating CHP and Wind Power Units Using SDP Technique

Kolapo Sulaimon Alli, Abimbola Muideen Jubril, and Lawrence O. Kehinde


CAS-062: Peristaltic Transport of an Ellis Fluid in an Inclined Channel

Andre Small, Marneni Narahari and Nagarani Ponakala


CAS-063: Dynamics of e-Rumor Models

Severine Bernard, Alain Pietrus and Kendy Valmont


CAS-064: Rapid Propagation of Improved Cassava Varieties Using the Multiple Shoot Removal Technique

Fradian V.N. Murray, Jane E. Cohen and L. Myers-Morgan


CAS-065: Muscadine Grape Skin Extract Decreases Proliferation of Prostate Cancer Cells by Affecting Proteins Involved with the Cell Cycle and the Androgen Receptor

Diane N. Ignacio, Trevor Alleyne, Tamaro S. Hudson, and Sonia Peter


CAS-066: Components of a Leaf Extract of an Exotic Caribbean Plant Inhibits Growth of PC-3 Androgen Independent Prostate Cancer Cells

Dunstan Arrindell, Shantelle Henry, Diane N. Ignacio, Sonia Peter and Trevor Alleyne


CAS-067: Carbon Storage Change as It Relates to Land Use and Texture in a Tropical Forest Ecosystem

Melissa A. Atwell, Mark N. Wuddivira, and Mike P. Oatham


CAS-068: Guyana-Suriname Energy Resources

Sally Radford


CAS-069: Students' Conceptions about Geothermal Energy in the Caribbean

Claire Anjou, Thomas Forissier and Yves Mazabraud


CAS-070: Underpinning Intercultural Competence within a Context-Effect Didactic Method

Lamprini Chartofylaka, and Thomas Forissier




CAS-071: Essential Oil Composition and Antimicrobial Activity of Cannabis Sativa Grown in Jamaica at Five Stages of Maturity

Kellyann Clarke, Roy Porter, Petrea Facey and Camille Thoms-Rodriguez


CAS-072: Duration of Life Cycle Stages of Four Species of Blowflies (Diptera: Calliphoridae)

Taneisha A. Barrett, Eric Garraway, Catherine Murphy, and Tannice Hall


CAS-073: The Impact of Dibenzyl Trisulfide on Breast Cancer Cell Lines Derived from African American Patients and on Cytochrome P450 1 Enzymes

Shaniece F. Wauchope, Jonathan V. Wooten, Nicole U. Mavingire, Petreena S. Campbell, JeAnn E. Watson, Eileen J. Brantley, Maxine D. Gossell-Williams, and Rupika Delgoda


CAS-074: Comparative Extraction Performance and Application of Sodium Alginate from Sargassum Seaweed

Tiffany S. Husbands, and Srinivasa R. Popuri


CAS-075: Bivariate Distributions with Transmuted Conditionals: Models and Applications

Anthonisamy Vincent Raja


CAS-076: Automated Pollen Recognition Using Shape, Texture Features and Logisboost Algorithm

Endrick Barnacin, Jean Luc Henry, Jack Moline, Benoit Foucan-Perafide and Jimmy Nagau


CAS-077: Dispersion of a Solute in Casson Fluid Flow under the Influence of External Body Acceleration

Ajani Ausaru and Nagarani Ponakala


CAS-078: Agriculture and a Knowledge-Based Economy - Gender: Missing in Action

Dorienne A. Rowan-Campbell


CAS-079: Making It Drier: How Pinus Caribaea Influence the Hydrology in Forested Tropical Watersheds

Jesse R. Francis, Kegan Farrick and Mark N. Wuddivira


CAS-080: Free Radical Scavenging Activity, Total Phenolics and Metabolites Identified in Rivina Humilis Berries

Andrea Goldson Barnaby, Kailesha Duffus, Hensleisha Virgo, and Raymond Reid




CAS-081: Producing Valuable Protein Concentrates from the Cassava Crop's Post Harvest Waste Products

Annaleise H.L. Aiken, Ian L. Thompson, Diptendu Chatterjee and G. Harvey Anderson


CAS-082: The Design and Fabrication of a Function Fertitliser

Robert A. Birch, Stefan Thompson, and Gaius Eudoxie


CAS-083: Focusing on Interactions between Individuals and Their Learning Environment: A New Step Forward for Science Education

Alexandra Renouard and Yves Mazabraud


CAS-084: Coffee Crop Phenology and Infestation by the Coffee Berry Borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae) in the Highlands and Blue Mountains of Jamaica

Ameka N. Myrie and Dwight E. Robinson


CAS-085: Response Analysis of Fuzzy Fractionally Damped Mechanical Spring-Mass System

Diptiranjan Behera


CAS-086: New Rare-Earth Metal-Organic Frameworks from Perhalogenated Terephthalate Ligands: Fluorescence Sensors for Iron, Copper and Nitroaromatic Explosives

Jermaine A. Smith, Marvadeen A. Singh-Wilmot, Korey P. Carter, Christopher L. Cahill and James A. Ridenour


CAS-087: Applications of the Lagrangian Method to Heun Function

Davide Batic, Omar A. Forrest, and Marek Nowakowskic


CAS-088: Crystal Engineering of Lanthanide Metal-Organic Frameworks (Ln-MOFs) Using Conceptual Tertiary Building Units (TBUs)

Zeyar Min, Marvadeen Singh-Wilmot, and Richard Taylor


CAS-089: A Portable Modular Mechanised System for In-field Transporting of Harvested Cocoa

Daniel Hosein, Robert A. Birch, Renique Murray, and Cilla Pemberton


CAS-090: Synthesis, Characterisation, Luminescence and Sensing Capabilities of a New 2-Hydroxyterephthalate Lanthanide MOF

Christopher Hossack, Zeyar Min, and Marvadeen Singh-Wilmot




CAS-091: The Use of Web-based Geographical Information Systems (GIS) and Data Visualisation Tools for Productivity Measurement in the Public Sector

Hollee Roberts and Ruel L.A. Ellis


CAS-092: Developing a Casebook of Quality Management Practices of Industrial enterprises in Trinidad and Tobago: An Agenda

Kit Fai Pun


CAS-093: A Mechanised Cocoa Dryer Chamber

Robert A. Birch, Rodney Seepersad, Renique Murray, Cilla Pemberton, and Edwin I. Ekwue


CAS-094: Anaerobic Microbial Degradation of Chlordecone in Microcosms from Guadeloupe Soil

Suly Rambinaising, Laurent Laquitaine, Ronald Ranguin, Corine Jean-Marius, Line Lomheim, Andrei Starostine, Luz A. Puentes, Elizabeth A. Edwards, and Sarra Gaspard


CAS-095: Engineering Programmes and Economic Development in the SIDS of the Caribbean and South Pacific

Cilla Pemberton, John Pumwa, Rajeshkannan Ananthanarayanan, and Oneil Josephs


CAS-096: Investigating Fracture and Crack Propagation in Soils Using MATLAB: A Novel Technique

Robert A. Birch; Jacqueline Bridge; and Edwin I. Ekwue


CAS-097: The Potential Chemo-preventive Value of a Prenylated Flavonoid Isolate of Jackfruit

Isaac J. Morrison, JeAnn E. Murray, Roy Porter, and Rupika Delgoda


CAS-098: Integrated Production of Biodiesel and Purified Glycerol from Waste Cooking Oil

Michael D. Coley, Denise D. Campbell, and Dale R. Rankine


CAS-099: Flood Management in Informal Settlements: The Case of Les Cayes, Haiti

Wisly Jean-Claude and Asad Mohammed


CAS-100: Africanized Bees - The Bees of the Future

Jo-Anne N. Sewlal, Ricardo G. D'Andrade, Hayden A. Sinanan, and Gordon P. Deane




CAS-101: Food Fraud - Honey Laundering

Jo-Anne N. Sewlal, Ricardo G. D'Andrade; Hayden A. Sinanan, and Gordon P. Deane


CAS-102: MHealth Disease Surveillance and Monitoring Among the Jamaican Diabetic Community: A Cross-sectional Study of the Interest to Use Health Mobile Apps

Susan A. Muir


CAS-103: The Impact of Fitspiration (via Social Networking Sites and Mobile Applications) on the Physical Activity Levels and Body Image of Female University Students

Susan A. Muir  


CAS-104: The Fermentation of the Pulp of Watermelon (Citullus lanatus) in the Absence and Presence of Metal Additives with a View to Obtain Ethanol for Commercial Use

Raymond C. Jagessar and Jamacey Lynch


CAS-105: The Status of Surface Water in Linden and Coastal Guyana

Raymond C. Jagessar and Reshmee Lakhan


CAS-106: Synthesis of Nanoparticle of Carbon

Thierry Cesaire, Gabriel Carbonnel, Yves Bercion, Audrey Molza and Philippe Thomas


CAS-107: Tribological Properties of Vegetable Oils Added with Graphite Particles in Dodecane

Nadiege Nomede-Martyr, Jacques-Louis Ricard, Rachel Rossi, Philippe Bilas, Thierry Cesaire, and Philippe Thomas


CAS-108: Integrated Health Information Systems for Diabetics in Guyana

Alicia Layne, Malcolm Williams, and Roland Daynauth


CAS-109: An Investigation of Cognitive Overload and Reaction Time in Mobile Augmented Reality Environments

Amrita Ramnauth and Penelope G. DeFreitas


CAS-110: VisC - A Visualisation Tool for Learning Fundamental Programming Concepts

Dave U. Sarran and Lenandlar Singh




CAS-111: Unlearning Learned Helplessness: A Computerised Cognitive Behavioural Therapy Approach

Juanelle Marks, Malcolm Williams, and Aurell Liddell  


CAS-112: Promoting Computer Science Education in a Developing Country: Experiences from 'Code Camp Guyana'

Juanelle Marks and Lenandlar Singh  


CAS-113: The Use of Keystroke Dynamics as the Primary Basis of Authentication

Kwesi Elliot, Dave Sarran, Lenandlar Singh, and Troy Thomas


CAS-114: A Model to Support the Development of Undergraduate Research in Computer Science

Lenandlar Singh


CAS-115: An Exploration of Users' Perspectives on Software Updating Message Design

Neil Balram, Aurel Liddell, and Lenandlar Singh


CAS-116: Advancing Undergraduate Research in the Disciplines: Insight and Ideas from the University of Guyana

Pamela Rose, Troy Thomas, and Lenandlar Singh


CAS-117: The Perception of Electronics Waste Management and Disposal Practices in Guyana

Penelope G. DeFreitas


CAS-118: First Time Experiences of Females Programming at the Grade 6 to 9 Level

Penelope G. DeFreitas, and Alicia Layne  


CAS-119: The Importance of a National Approach to Cyber Security in a Knowledge-based Economy

Sandra Khan and Malcolm Williams


CAS-120: Using a Web-based Student Response System to Promote Active Learning in a Classroom Setting

Vineeta Persaud and Rita Persaud


CAS-121: Engineering Nanostructured Ceramics Based on Ancient "Cobalt Blue" Technology

Krystal M. Cunningham, Federico Caro and Ioanna Kafoulli


CAS-122: The Global and Local Impact of Road Traffic Injuries. Is it an Epidemic?

Shuvra Dasgupta