Nishith Dharaiya - Academia.edu (original) (raw)

Papers by Nishith Dharaiya

Bears of the World

The Zero-Range Process, in which particles hop between sites on a lattice under conserving dynami... more The Zero-Range Process, in which particles hop between sites on a lattice under conserving dynamics, is a prototypical model for studying real-space condensation. Within this model the system is critical only at the transition point. Here we consider a non-conserving Zero-Range Process which is shown to exhibit generic critical phases which exist in a range of creation and annihilation parameters. The model also exhibits phases characterised by mesocondensates each of which contains a subextensive number of particles. A detailed phase diagram, delineating the various phases, is derived.

LIFE SCIENCES LEAFLETS, 2018

Remote sensing has become a very powerful tool for crop condition assessment and management. The ... more Remote sensing has become a very powerful tool for crop condition assessment and management. The objective of this study was to understand the effectiveness of basal crop coefficient (Kcb) values estimated from remote sensing and their application in real time crop water requirement. During the crop growing season, the value of Kc for most agricultural crops increase from a minimum value at emergence in relation to change in canopy development, until a maximum Kc is reached at full canopy cover. The study was carried out for the Cotton crop in Sirsa district of Haryana. A spectral index such as SAVI (Soil Adjusted Vegetation Index) and Fractional Vegetation Cover (Fc) was used to estimate Kcb value. High spatial resolution Landsat TM 5 images were used to generate a spectral profile of NDVI, SAVI, and Fc for different crop cover. Using, available empirical models from literature, crop coefficient was derived from SAVI values. Reference Crop Evapotranspiration (ET0) was estimated usi...

Plastics have battle to biological breakdown that result in its accumulation in the environment. ... more Plastics have battle to biological breakdown that result in its accumulation in the environment. This accentuates the need to search for biodegradable polymer, which is readily disposable and degradable. Bacteria synthesize and accumulate polyhydroxy alkanote (PHA) as carbon source under limiting conditions of nutrients. Bioprospecting for poly-β-hydroxyalkanoate (PHA)-accumulating micro-organisms was carried out in edible oil contaminated soil of north Gujarat region. They were isolated in unbalanced culture medium (high carbon/nitrogen ratio) with various edible oil used as carbon source. PHAs producing bacteria were identified by staining with Sudan black and solubilising cellular components in sodium hypochlorite. Two bacterial strains isolated, screened and characterized from edible oil contaminated soil samples were selected due to their capacity of growing in the presence of edible oil and at the same time producing PHA. The isolates were identified by PCR of the 16S rDNA gen...

Analysis of pest impact assessment using remote sensing is based on that pest infestation change ... more Analysis of pest impact assessment using remote sensing is based on that pest infestation change the photosynthesis and physical structure in plants, which in term alter the absorption and reflectance property of plant in electromagnetic spectrum. Productivity of cotton crop grown in India is at risk due to the incidence of new emerging pests, especially after introduction of BT cotton varieties. Crop losses due to new pests like mealybug can be substantial and may be prevented, or reduced, by crop protection measures. An attempt has been made on identification of probable hot spots of mealybug concentration zones in cotton crop. A methodology is developed for estimation of pest affected areas using two years Indian Remote Sensing and MODIS satellite data and ground measured severity index of the pest concentration. The pest severity index seems to have high correlation with the satellite derived index which can be used to locate the severely affected zones in the district so that c...

Detection of crop stress is one of the major applications of remote sensing in agriculture. Many ... more Detection of crop stress is one of the major applications of remote sensing in agriculture. Many researchers have confirmed the ability of remote sensing techniques for detection of pest/disease on cotton. Hence, this research was designed to investigate, (1) to study the spectral properties of noninfested and mealybug infested cotton crop (ii) damage assessment using remote sensing derived index. Mealybug-infested cotton crop showed significantly lower reflectance in the near infrared region and higher in the visible region of the spectrum compared with the noninfested cotton crop. Mealybug Pest Stress Index-8 (MPSI-8), a remote sensing index derived in this study shows a significant negative relationship with mealybug severity (r 2 =0.6319) and shows the potential to assess the pest and disease damage because of its characteristic that include pigment, leaf structure, and water sensitive band. MPSI-8 depicts the change in pigment concentration and water stress and shows a negative...

Mangrove ecosystem serves as feeding and breeding ground for variety of living organisms includin... more Mangrove ecosystem serves as feeding and breeding ground for variety of living organisms including crustaceans, mollusks, fish and many resident and migratory birds. Macro invertebrate fauna are first consumer of mangrove detritus, decomposition matter and hence play a vital role in regulating food web in mangrove ecosystem. Macrofauna are also the most preferred food of migratory as well as resident birds occurring in mangrove ecosystem. The present study provides the baseline information on bird and macrofauna diversity in Jakhau creek system. The bird and macrofauna sampling were carried out at regular interval through point count method. Total 65 bird species belonging to 17 families have been recorded. Out of all recorded bird species, 49% were migratory. 27 species of macro invertebrate were recorded in to five major groups Viz. polychaetes (30%), crustaceans (30%), gastropods (26%), bivalves (7%) and fish (7%). The study reveals that the mangrove ecosystem of Jakhau creek can...

European Journal of Experimental Biology, 2013

Polyhydroxyalkanoates(PHAs) are biodegradable polymers produced by microbes to overcome environme... more Polyhydroxyalkanoates(PHAs) are biodegradable polymers produced by microbes to overcome environmental stress condition. Commercial production of PHAs due to its high cost is limited compared to that of conventional polymers. Another hindrance is the brittle nature and low strength of Poly-3-Hydroxybutyric Acid (PHB), the most widely studied PHA. The needs are to produce PHAs, which have better elastomeric properties suitable for biomedical applications, preferably from inexpensive renewable sources to reduce cost. Certain unique properties of Bacillus subtilissuch as lack of the toxic lipo-polysaccharides, expression of self-lysing genes on completion of PHA biosynthetic process – for easy and timely recovery, usage of bio wastes as feed enable it to compete as potential candidate for commercial production of PHB. Bacillus subtiliswas found to produce PHB and the amount of PHB produced was estimated under various conditions like pH, temperature, and also using different substrates. ...

North-Eastern Gujarat is known for its high density populatinn in lndb. Local csrmrrny arunct the... more North-Eastern Gujarat is known for its high density populatinn in lndb. Local csrmrrny arunct the forests is mainly depending upon the local forest produces and sharing many resources with the wildlife lirres Ute eh, *rl*r seforn resutts in the human-wildlife confrontation and conflicts. The present study has been canied out to knorv fie bod 6p1rpq(ilin d Slo01 bear in the area and the seasonal variation in their diet composition. Scat analysis technQue was enrpbyed b lcw he food oa Stofi bear in different season along with the sign survey to know the habitat use. The scat study revealed that a sffi bear h fE area cfiiefry @nsumes fruits of five plant species, followed by termites, ants and bees. No any signifiEnt seasonal varktrims h bd cqrpqsfbn of Sloth bear were founo; however high consumption of termites and ants (79.Y/") recorded during monsocr ard wirEr, *.e h srnner the bear mainly depends on the fruits. Among the frulls, Zizipus species appe€rr to be importantlood rsrc...

Environmental biotechnology has the intention of increasing sustainability of production process ... more Environmental biotechnology has the intention of increasing sustainability of production process by employing biological systems and human life. In the present study, three different types of plastics were used to check their degradability by using degradability test. The microorganism isolated from oil contaminated soil was found to utilize the edible oil (coconut oil) as a carbon source. These microorganisms were used for the further investigation to produce plastic from the granules, its durability and degradability is in progress. Sudan black staining of this microorganism reveals the presence of PHA granules inside the microorganism. These granules are after extraction useful to produce the plastic film assuming to be used as one of alternatives of biodegradation plastic. TiO2 powders are used for the preparation of microbial plastic. Check their degradability at same time and same species in MMSB medium during these study microbial plastic is highly degradable compare to starc...

Biodiversity conservation is becoming a large concern with the rapid pace of urbanization in deve... more Biodiversity conservation is becoming a large concern with the rapid pace of urbanization in developing countries. Currently biodiversity conservation is limited to conservation of existing natural green areas, like National Park, and Sanctuaries. This research undertaken by the authors and funded by the Mumbai Metropolitan Region Environment Improvement Trust, proposes to map association within and amongst communities to study, evaluate and make maximum use of such floral-floral and floral – faunal associations to develop and sustain the ecological balance of urban areas through natural processes. The research proposes ways of integrating this with urban landscaping to make the urban areas more rich in biodiversity.

Ecotoxicology, 2018

Organochlorine compounds (OCs) pose a serious threat towards the wildlife due to their well-known... more Organochlorine compounds (OCs) pose a serious threat towards the wildlife due to their well-known adverse effects. India is the second largest producer of pesticides in Asia, with DDT production still ongoing, and is ranked amongst the leading countries of pesticide consumption. However, a significant data gap in avian biomonitoring studies has been identified in Asia. The objective of this review is to compile and discuss the available literature on concentrations of organochlorine pesticides and PCBs in Indian birds. The review of 18 articles showed that DDTs were the OCs most frequently analysed, followed by HCHs and PCBs (highest hepatic mean values: 11.6, 1.8 and 1.03 µg/g ww, respectively). The most frequently analysed matrix was whole body homogenates, followed by internal tissues. Plasma, eggs, feathers and guano were poorly sampled. The range of sampling years was 1980-2007. In general, hepatic OC concentrations were below the level known to cause adverse effects, although p,p'-DDE in eggs was found in concentrations associated with eggshell thinning. Most of the studies were carried out in Southern India (Tamil Nadu). Out of 106 species studied, house crow (Corvus splendens) was the most frequently monitored. However, the number of individuals sampled per species is generally low and different sample types are used, thus, huge limitations to compare OC exposure exist. This review shows that there is a clear deficit of data on OC concentrations and sublethal effects that needs to be addressed to understand the status of OC exposure, spatio-temporal trends and potential impacts in Indian avifauna.

Tigerpaper, 2009

This study was conducted from January 2006 to January 2007 to determine the food composition and ... more This study was conducted from January 2006 to January 2007 to determine the food composition and habitat use through scat analysis, direct encounters and sign surveys of the striped hyena (Haeyena haeyena) in North Gujarat, India. The study area comprises a wide spectrum of ...

Human–Wildlife Interactions, 2018

Conflicts with wild animals are increasing as human populations grow and related anthropogenic ac... more Conflicts with wild animals are increasing as human populations grow and related anthropogenic activities encroach into wildlife habitats. A good example of this situation is the increase in conflicts between humans and sloth bears (Melursus ursinus) in India. Sloth bears are known for their aggressive and unpredictable behavior. More human fatalities and injuries have been attributed to sloth bear attacks than all recorded incidences of wildlife attacks in Buldhana Forest Division of Maharashtra, India. We interviewed 51 victims that were attacked by sloth bears between 2009-2017 to better understand the reasons for the attacks. Thirtyfour of the attacks (66.7%) resulted in serious injuries, and there were 7 human mortalities (13.7%) reported. Most attacks occurred close to agricultural fields (66.7%) and during midday (1100–1400 hours). More attacks (64.7%) occurred when a person was working or resting in the field, or retrieving water for the field followed by attacks while watch...

Proceedings of the Zoological Society, 2021

The anatomic study of guard hairs found on epidermis of the mammals have proven to be an effectiv... more The anatomic study of guard hairs found on epidermis of the mammals have proven to be an effective way in identifying the species. Many researchers have been employing this methodology as an aid in wildlife forensics also creating the dataset of hair structures enabling them to explore different aspect of wildlife ecology. The goal of the present study is to develop a key of hair structures that can be helpful to researchers, wildlife managers and forensics for rapid identification of mammal species. In this study, 16 different mammals found commonly in North Gujarat were selected to develop the identification keys. The morphology and anatomical structure of hair samples were studied by cross-sectioning, analyzing cuticular structure and hair imprinting. A photographic reference was developed using the identification characteristics. This would be helpful in drawing comparisons with the unidentified hair samples collected as it is difficult to have direct sightings of mammals in the field every time. Photographic references have been given in the paper for efficient and timely interpretation of results.

Journal of Environmental Studies, 2021