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Dr. A.S. Dixit

FACULTY

Name:  Prof. A. S. Dixit

Designation:  Professor

Specialization:  Endocrinology

 

Contact Information:

Department of Zoology,
North-Eastern Hill University
Shillong 793022,
Meghalaya, INDIA

Tel.: +91 364 272 2309  Fax: +91 364 272 2301  Mobile: +919436312383 

Email:- asdixitnehu@rediffmail.com, asdixitnehu@gmail.com

 

Academic Qualifications:

Degree

Year

University

B. Sc.

1977

Banaras Hindu University

M. Sc.

1980

Gorakhpur University

Ph. D.

1987

Banaras Hindu University

 

Fellowships/Awards/Recognitions:

   As faculty 

  • Vice- President: Indian Society for Chronobiology, 2019-2021.
  • Vice- President: Association of Avian Biologists in India, 2018-Contd.
  • Subjected Expert: Selection Committees for recruitment and promotion of faculty in some Indian Universities.
  • Reviewer for number of International Journals in Zoology/ Biology/ Behavior/ Chronobiology.
  • Editorial board member: Global Journal of Zoology; International Journal of Research Studies in Zoology; The NEHU journal.
  • Executive committee Member: Indian Society for Chronobiology, 2017-2021.
  • Vice- President: Indian Society for Chronobiology, 2013-2017.
  • Coordinator: 3rd DST-SERB School in Avian Biology, Shillong, 2015.
  • Member of the PG e pathsala team to develop e content for Zoology (Chronobiology) under UGC National Mission on Education through ICT (NME-ICT) Project.
  • Coordinator: DST-SERB School in Chronobiology, Shillong, 2012.
  • Member: National Coordination Committee, International Congress on Chronobiology, Dept. Zoology, Delhi University, 2012.
  • Member: DST-National Planning Committee for SERB School in Chronobiology, 2010-15.
  • Faculty: DST-SERC/SERB School in Chronobiology (2009-15).
  • Coordinator: DST-SERC School in Chronobiology, Shillong, 2009.
  • Member: Organizing Committee, 96th Indian Science Congress, NEHU, Shillong, 2009.
  • Reviewer for the development of NCERT Textbook in Biology (Class XII), 2006

As student

  •    Research Associate, CSIR-New Delhi, May 1988 to August 1990.
  •    Sr. Research Fellow, CSIR-New Delhi, January 1986 to April 1988.
  •    Sr. Research Fellow, UGC-SAP, March 1985 to December 1985.
  •    Jr. Research Fellow, UGC-SAP, April 1983 to February 1985.
  •    Certificate of Merit for best research paper and presentation, 71st ISCA, Ranchi, 1984.
  •    B.H.U. Research Scholarship April 1981 to March 1983.

 

Teaching Experience:  ~29 years (Since August 1990)

Research Experience: ~ 39 years (Since March 1981)

 

Research focus and Major areas of Research

Cycles in biological systems are all pervasive in Nature. Birds like any other species express daily rhythms in activity/rest, hormone secretion and several other rhythmic characteristics. Most bird species also show long-term cycles in feeding behavior, body fattening (in migrants), reproduction, moult, or migration. Both daily and seasonal behaviors are under the strict control of the endogenous clock mechanisms, but the role of environment remains critical for optimal performance and ultimately the survival. Synchrony with the environment is achieved through interaction of clock component with external cues (e.g. photoperiod), and internal coordination among different rhythmic physiological correlates is achieved through neural and endocrine signaling. Thus, we are interested to learn about how birds achieve precision in timing their daily and seasonal activities in synchrony with the periodic environment. Our research effort mainly centers around the “Avian Circadian and Seasonal Systems: Study from Behavior to Molecules”. The working hypothesis has been that specialized cells localized in different tissues express genes involved in the clock circuitry, and different cell populations control the food intake, body fattening, reproductive axis, molt and migration, in a way that each event can be timed and spaced with each other to optimize an ecological adaptation.

Research Themes          

  • Clocks controlled daily and seasonal behaviors (e.g. migration and reproduction).
  • Neurobiology of seasonal behaviors. Neuronal changes in the brain (neurogenesis/synaptogenesis) in response to seasonality and hormone status. Hormonal modulation of brain functions.
  • Hypothalamic expressions and roles of GnIH and GnRH-I, TSHβ, Dio2 and Dio3 in photoperiodic regulation of avian seasonality.
  • Endocrinology of seasonal reproduction and related behaviors (with reference to hormones of HPG axis).
  • Physiology of reproduction and migration.
  • Metabolism: glucose uptake studies in response to daily and seasonal changes.
  • Endocrinology of free-living birds. Measurement of hormones and recording their behavioral changes.
  • Clock and metabolism using migratory birds as model systems.
  • Life style patterns and biological clock mediated functions in human.

Model systems

Non-migratory and migratory songbirds.

Techniques we use

  • Monitoring of activity rest rhythm and feeding behavior by using chronobiology software.
  • Anatomical modifications in the brain in relation to seasons and physiological status.
  • ELISA.
  • Non-invasive study of seasonality (feather regeneration and molt, body fattening, food intake, plumage and bill color scores etc.).
  • Metabolic activity through respirometer.
  • Immunohistochemistry.
  • PCR and Real time quantitative PCR.
  • Laparotomy and other approaches used for studying photoperiodism and seasonal reproduction.

 

Major Research Projects undertaken:

  1. Role of proximate factors in timing the seasonal breeding in Passeriformes finches of North-East. DST, New Delhi (2008-2011).

  2. Role of kisspeptin and GnIH in regulation of seasonal breeding in the tree sparrow. DST, New Delhi (2013-2016).

  3. Anticipation in genes: Molecular, physiological and behavioral correlates of response of circa-annual clocks to seasons in night-migratory songbirds: Investigation of physiological and metabolic adaptations in migrants”. DBT, New Delhi (2013-2018).

  4. Effect of climate change on breeding strategies of songbirds. DBT Twining, New Delhi.

 

Memberships of Scientific societies etc.:

  • Life and Executive Committee Member: Indian Society for Chronobiology.
  • Member: International Society for Chronobiology.
  • Member: DST National Planning Committee, SERB School in Chronobiology, Department of Science and Technology, New Delhi.
  • Member: International Ornithological Society.
  • Life member: Association of Avian Biologist in India.

 

Administrative Responsibilities:                                                                                                         

  • Member: Academic Council, 01.01.2012 till date, North-Eastern Hill University, Shillong.
  • Member: Committee on National Institutional Ranking Framework, 21.10.2016 till date, North-Eastern Hill University, Shillong.
  • Member: Internal Quality Assurance Cell (IQAC), 29.05.2017 to 28.05.2019, North-Eastern Hill University, Shillong.
  • Member: Board of Research Studies, 1.8.2010 till date, North-Eastern Hill University, Shillong.
  • Member: School Board of life Sciences, 6.8.2008 to 5.8. 2010 and from 01.01.2012 till date North-Eastern Hill University, Shillong.
  • Member: Board of Study in Zoology, North-Eastern Hill University, Shillong.
  • Member: Board of Post Graduate Studies in Zoology, 28.5.2007 to 27.5.2010, North-Eastern Hill University, Shillong.
  • Member: Board of Under Graduate Studies in Pisciculture, 11.8. 2010 to 10.8. 2012, North-Eastern Hill University, Shillong.
  • Member: Vidyalaya Management Committee, 2010, Kendriya Vidyalaya, NEHU, Shillong.

 

Number of M. Phil. /Ph. D. produced: 4

Sl. No.

Name

     

Year

                      Title of thesis

1.

Dr. Namram Sushindrajit Singh

2012

Role of photoperiod in timing seasonal breeding in the tree sparrow, Passer montanus (Linneus).

2.

Dr. Ramita Sougrakpam

2013

Photoperiodic regulation of seasonality in reproduction in the yellow-breasted bunting,  Emberiza aureola (Pallas).

3.

Dr. Iadalangki Bamon

2018

Studies on the effects of photic and non-photic cues on circadian and seasonal responses in the tree sparrow, Passer montanus (L.)

4.

Dr. Sanborlang Byrsat

2019

Expression of gnrh-I and gnih genes and their roles in photoperiodic contol of seasonal breeding in tree sparrow, Passer montanus  L.

 

Number of Ph. D. students working for the degree: 3

Sl. No.

Name

Year of joining

                      Title of thesis

1.

 

Ms. Ranju Chetri

2014

Physiological and metabolic changes in response to photoperiods in the migratory red-headed bunting, Emberiza bruniceps Brandt.

2.

Mr. Debashish Khanikar

2017

Effects of climatic factors on breeding biology of spotted munia, Lonchura  punctulata L.

3.

Ms. Bidisha Kataki

2019

Hypothalamic expressions of TSH-β, Dio2 and Dio3 gene in photoperiodic regulation of reproduction in the tree sparrow, Passer montanus (Linneus).




Publications:

National: 9

International: 9

Updated by lakmen_zoology on Jul 04, 2019 15:15:07