Ramesh T.,University of KwaZulu - Natal |
Kalle R.,University of KwaZulu - Natal |
Kalle R.,Nalanda University |
Downs C.T.,University of KwaZulu - Natal
Behavioral Ecology and Sociobiology | Year: 2017
Abstract: Top predators often have cascading effects on mesopredator communities by driving behavioural changes. Using camera-trapping surveys, we explored the site-detection probability of sympatric predators and temporal overlap and examined behavioural patterns to explore hypotheses of carnivore guild interactions between and within large and small predators in the presence/absence of lion (Panthera leo) in open and closed habitat cover. We used single-season two-species occupancy models to test inter-predator interactions at 205 camera sites spread across five Protected Areas of the Maputaland Conservation Unit, South Africa. These data showed the respective associations between the presence of large carnivores and smaller carnivores. We observed that leopard (Panthera pardus) and hyena (Crocuta crocuta) tended to avoid interference encounters, as they were less likely co-detected at the same sites. There was a decrease in detection of leopard and hyena as a function of lion presence. Small predators such as the group honey badger (Mellivora capensis)-striped polecat (Ictonyx striatus) and the slender mongoose (Herpestes sanguineus) were detected less often at cameras where leopards were detected. Detection probabilities of the group badger-polecat and slender mongoose were much higher in the closed habitat than in open habitat where leopards were detected. At camera sites where hyenas were detected, badger-polecat and genet (Genetta tigrina) detection probability was much higher in the closed habitat than open habitat. Slender mongoose overlapped less temporally with large predators while others did not. Our study showed that large predator guilds can affect the probability of detecting subordinate mesopredators; therefore, reintroduction of large carnivores can have a cascading effect on subordinate carnivores, and it is necessary to consider this effect when planning recovery programmes for carnivore conservation. Significance statement: We think this study is of importance and interest as top predators often shape mesopredator communities by inducing apparent avoidance behaviour based on associations between the presence of large carnivores and smaller carnivores. As a consequence, smaller predators use closed habitat to minimize the risk of larger predators due to intraguild interference interaction. We explored behavioural patterns of sympatric predators’ site detection probability and temporal overlap and examined hypotheses about carnivore guild interactions between leopard and spotted hyena, these two and small predators with and without lion in open and closed habitat cover. Reintroduction of one carnivore population can have cascading effects on the other, and this nature of consequences needs to be accounted when planning conservation or species recovery programmes. Therefore, we extended our study to explore these important aspects. Our study is novel as there are no studies documenting species interactions between/within large and small predators from co-occurrence patterns in South Africa. © 2017, Springer-Verlag Berlin Heidelberg.
Kalle R.,University of KwaZulu - Natal |
Kalle R.,Nalanda University |
Combrink L.,University of KwaZulu - Natal |
Ramesh T.,University of KwaZulu - Natal |
Downs C.T.,University of KwaZulu - Natal
Ecology and Evolution | Year: 2017
Distributions of avian mutualists are affected by changes in biotic interactions and environmental conditions driven directly/indirectly by human actions. The range contraction of red-billed oxpeckers (Buphagus erythrorhynchus) in South Africa is partly a result of the widespread use of acaracides (i.e., mainly cattle dips), toxic to both ticks and oxpeckers. We predicted the habitat suitability of red-billed oxpeckers in South Africa using ensemble models to assist the ongoing reintroduction efforts and to identify new reintroduction sites for population recovery. The distribution of red-billed oxpeckers was influenced by moderate to high tree cover, woodland habitats, and starling density (a proxy for cavity-nesting birds) with regard to nest-site characteristics. Consumable resources (host and tick density), bioclimate, surface water body density, and proximity to protected areas were other influential predictors. Our models estimated 42,576.88–98,506.98 km2 of highly suitable habitat (0.5–1) covering the majority of Limpopo, Mpumalanga, North West, a substantial portion of northern KwaZulu-Natal (KZN) and the Gauteng Province. Niche models reliably predicted suitable habitat in 40%–61% of the reintroduction sites where breeding is currently successful. Ensemble, boosted regression trees and generalized additive models predicted few suitable areas in the Eastern Cape and south of KZN that are part of the historic range. A few southern areas in the Northern Cape, outside the historic range, also had suitable sites predicted. Our models are a promising decision support tool for guiding reintroduction programs at macroscales. Apart from active reintroductions, conservation programs should encourage farmers and/or landowners to use oxpecker-compatible agrochemicals and set up adequate nest boxes to facilitate the population recovery of the red-billed oxpecker, particularly in human-modified landscapes. To ensure long-term conservation success, we suggest that the effect of anthropogenic threats on habitat distributions should be investigated prior to embarking on a reintroduction program, as the habitat in the historical range may no longer be viable for current bird populations. © 2017 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
Bhattacharya S.,Nalanda University |
Gupta K.,Presidency University of India |
Ghosh U.C.,Presidency University of India
IOP Conference Series: Materials Science and Engineering | Year: 2017
Arsenic contamination in the ground water has serious health consequences in many parts of the world. The surface sorption method for arsenic mitigation has been widely investigated due to its simple method, inexpensive operation, highly efficient and low content of by-products. In the present study, nanostructured hydrated cerium aluminum oxide (NHCAO) was synthesized and characterized and its arsenic (III) sorption behavior from the aqueous solution was studied. The material was characterized in SEM, FE-SEM, TEM, AFM, XRD, and FT-IR. Batch method was used for the kinetics of As (III) sorption on nanoparticles at 303 (± 1.6) K and at pH 7.0 (± 0.2). The experiments on isotherm subject were performed individually at 288K, 303K, 318K temperatures at pH 7.0 (± 0.2) using the batch sorption method. In the kinetics study of arsenic (III) sorption, the sorption percentage was observed to remain nearly unchanged up to pH 9.0, thereafter only slight reduction in sorption percentage. The equilibrium sorption results were tested using the models of Langmuir and the Freundlich isotherm. The Langmuir model is the most fitted model for the sorption reaction. NHCAO was highly efficient in As(III) removal out of the water in the extensive range of pH and could be used for arsenic removal from contaminated water. © Published under licence by IOP Publishing Ltd.
Sagar K.,Nalanda University
Disaster Advances | Year: 2017
The aim of the research was to assess climate change issues of relevance to traditional peoples' views and knowledge about climate change, its impacts and activities, adaptation strategies together with any perceive hindrance to its adaptation. These people are vulnerable to the effects of climate change due to their marginal location, low levels of technology, and lack of other essential farming resources. The research study was carried out in Nalanda district of Bihar (India), commonly known for its rich culture inherited from various dynasty and birthplace of and great personalities and several religions along with rich wildlife, birds and sanctuaries and immense agricultural activity. This research also aims to identify indigenous practices that jeopardize the sustainable development module among predominantly smallholder farmers by their knowledge of climate change impacts and adaptation strategies. This study utilizes information from questionnaire surveys administered to bureaucrats. Adaptation occurs through public policy making and decisions made by these stakeholders. The questions covered in the survey included a focus on possible holistic stakeholder perceptions in understanding the climate change effects on the environment, socio-economic status, current preparedness, coverage of climate change issues in current plans, the need to respond and the measures required. Climate change is potential threat to corrode the many development gains made by Bihar and it is believed that frequency and intensity of extreme weather events are likely to exacerbate in future.
Hedayati M.,Uppsala University |
Sharma P.,Nalanda University |
Katyal D.,Guru Gobind Singh Indraprastha University |
Fagerlund F.,Uppsala University
Journal of Nanoparticle Research | Year: 2016
Carbon-based engineered nanoparticles have been widely used due to their small size and unique physical and chemical properties. At the same time, the toxic effects of these nanoparticles on human and fish cells have also been observed; therefore, their release and distribution into the surface and subsurface environment is a subject of concern. The aim of this research is to evaluate and compare the transports and retentions of two types of engineered nanoparticles (multiwalled carbon nanotubes and C60) and the natural carbon nanoparticles collected from a fire accident. Several laboratory experiments were conducted to observe the transport behavior of nanoparticles through a column packed with silica sand. The column experiments were intended to monitor the effect of ionic strength on transport of nanoparticles as a function of their shapes. It was observed that the mobilities of both types of engineered nanoparticles were reduced with the increasing ionic strength from 1.34 to 60 mM. However, at ionic strengths up to 10.89 mM, spherical nanoparticles were more mobile than cylindrical nanoparticles, but the mobility of the cylindrical nanoparticles became significantly higher than spherical nanoparticles at the ionic strength of 60 mM. In comparison with natural fire-born nanoparticles, both types of engineered nanoparticles were much less mobile under the selected experimental condition in this study. Furthermore, inverse modeling was used to calculate parameters such as attachment efficiency, the longitudinal dispersivity, and capacity of the solid phase for the attachment of nanoparticles. The results indicate that the combination of the shape and the solution chemistry of the NPs are responsible for the transport and the retention of nanoparticles in natural environment; however, fire-burned nanoparticles can be highly mobile at the natural groundwater chemistry. © 2016, Springer Science+Business Media Dordrecht.
Seo S.N.,Nalanda University
Environmental and Ecological Statistics | Year: 2016
This paper evaluates behavioral adaptation models to climate change using South American agricultural data. This paper finds that the Ricardian model with spatial effects leads to 20 % loss of land value under the UK Hadley center (UKMO hereafter) model and 11 % loss under the milder US Goddard Institute (GISS hereafter) model by the middle of the century. The micro portfolio adaptation model (G-MAP hereafter), on the other hand, results in a much smaller damage estimate: 1 % loss of land value under the GISS model and 3.4 % loss under the UKMO model. Even with the G-MAP model, however, the land value of the crops-only system falls sharply by as much as 9.5 % under the GISS scenario. In contrast to the Ricardian model, the G-MAP model can explicitly explain the decisions to choose one of the agricultural systems as well as the conditional land value function for each system of agriculture. Under the GISS model, the choice of a crops-only farm declines by 3.3 % which is offset by an increase in the mixed system by 2.1 % and an increase in the livestock-only system by 1.2 %. Although the land value of the crops-only system falls by 9.5 %, the land value of the mixed system falls only by 3.5 % while that of the livestock-only system increases by a large percentage. This paper finds that the differences in the impact estimates between the two models result from the treatment of sunk cost. The result from the Ricardian model would deviate from that from the G-MAP model if sunk cost is significantly large. © 2015, Springer Science+Business Media New York.
Sharma P.,Nalanda University |
Sharma P.,Uppsala University |
Fagerlund F.,Uppsala University
Journal of Visualized Experiments | Year: 2015
Carbon nanotubes (CNTs) are widely manufactured nanoparticles, which are being utilized in a number of consumer products, such as sporting goods, electronics and biomedical applications. Due to their accelerating production and use, CNTs constitute a potential environmental risk if they are released to soil and groundwater systems. It is therefore essential to improve the current understanding of environmental fate and transport of CNTs. The transport and retention of CNTs in both natural and artificial media have been reported in literature, but the findings widely vary and are thus not conclusive. There are a number of physical and chemical parameters responsible for variation in retention and transport. In this study, a complete procedure of selected multiwalled carbon nanotubes (MWCNTs) is presented starting from their surface modification to a complete set of laboratory column experiments at critical physical and chemical scenarios. Results indicate that the stability of the commercially available MWCNTs are critical with their attached surface functional group which can also influence the transport and retention of MWCNT through the surrounding medium. © 2015 Creative Commons Attribution-NonCommercial License.
Kumar B.M.,Nalanda University |
Jose S.,University of Missouri
Agroforestry Systems | Year: 2016
Agroforestry entails different life forms including mixtures of trees that occupy different soil strata and exhibit a certain degree of spatial complementarity in resource use. However, rigorous experimental studies characterising root interactions in tree–tree systems are notoriously few. We present here the available empirical evidence to support the hypothesis that occurrence of two or more tree species close to one another may favour diminished lateral spread and/or deeper root penetration of the woody components and closer the tree components are located greater will be the subsoil root activity. These evidences are based on either root excavation studies in coconut-based multistorey production systems, or 32P soil injection experiments involving binary mixtures of coconut+interplanted dicot multipurpose trees (Vateria indica, Ailanthus triphysa or Grevillea robusta), and bamboo (Bambusa bambos)+teak (Tectona grandis) or Malabar white pine (V. indica). The excavation study denotes a spatially segregated root distribution pattern of the component species. Furthermore, in the coconut + dicot tree system, interplanted dicot trees absorbed considerable quantities of the radio-label applied to the palm, which declined log-linearly with distance from the palms, signifying a substantial potential for “capturing” the lower leaching nutrients, at proximal distances. Likewise, lower teak/Vateria root activity in the surface horizons and higher activity in the deeper layers, when bamboo clumps were nearby and vice versa when they were farther apart, implied that proximity of species/individuals favoured competitive downward displacement of roots. Nutrient pumping and/or current transfer of nutrients between the rhizospheres of the two associated crops are also possible. In designing sustainable agroforestry systems, it is, therefore, advantageous to mix trees with divergent root growth habits. © 2016 Springer Science+Business Media Dordrecht
Seo S.N.,Nalanda University
Economic Affairs | Year: 2015
This article develops the economics of adaptation to global warming as an optimal transition process to future climates. Three policy approaches that encompass the existing theories and policy options are initially outlined: measures based on individuals' social responsibility, government regulations, and carbon pricing. Evidence suggests that each of these options has little chance of being agreed upon and implemented at a global level. The economics of adaptation begins with climate signals which force individuals to adapt. Private adaptations are simultaneously tapped into for carbon dioxide removal and abatement. With increasingly severe damage over time, public sectors will be compelled to work in partnership with individuals and communities. Responding to amplifying climate signals, adaptation strategies evolve in such a way as to accelerate carbon dioxide reductions through low-carbon energy sources and technological solutions. Adaptations in a centuries-long timescale would effectively fend off dangerous global warming, but in a manner that is unbearably slow for the world's communities. The optimality of the transition process is based on micro efficiency, coordination, and the public goods nature and unique characteristics of specific adaptation strategies. © 2015 Institute of Economic Affairs.
News Article | February 3, 2016
Three murders, a suicide and a rash of political appointments at universities have thrown Indian academia into an uproar against the conservative (right-wing) government. Prominent artists, writers, historians and scientists are speaking out against an intensifying climate of religious intolerance and political interference in academic affairs. “What’s going on in this country is really dangerous,” says Rajat Tandon, a number theorist at Hyderabad Central University. Tandon is one of more than 100 prominent scientists, including many heads of institutions, who signed a statement protesting “the ways in which science and reason are being eroded in the country.” The statement cites the murder of three noted rationalists — men who had dedicated their lives to countering superstition and championed scientific thought — and what they see as the government’s silent complicity. Prime Minister Narendra Modi leads the Bharatiya Janata Party (BJP), which won the 2014 general elections in India in a landslide victory. The BJP and Modi, in particular, are aligned with the extremist right-wing group Rashtriya Swayamsevak Sangh, or RSS. (This unholy alliance is comparable to the relationship between the Republican Party and the Tea Party, but the RSS is a paramilitary group with more violent overtones than the Tea Party has shown so far.) Together, the BJP and RSS promote the agenda of Hindutva, the notion that India is the homeland of Hindus and all others — the hundreds of millions of Muslims, Christians, Sikhs and others in this sprawling, secular democracy — are interlopers. “The present government is deviating from the path of democracy, taking the country on the path to what I’d call a Hindu religious autocracy,” says Pushpa Mittra Bhargava , who founded the prestigious Centre for Cellular & Molecular Biology in Hyderabad. Despite his blatantly anti-secular stance, Modi’s stated goals for economic development are wildly popular, particularly among the country’s majority Hindus. But academics and intellectuals have been protesting the erosions on academic freedom almost from the start. In January 2015, at the 102nd session of the Indian Science Congress, several members of the BJP government led a session on ancient Indian science and claimed that thousands of years ago, Indians had built planes that could fly not just on earth but between planets. There were other outlandish claims — that the elephant-headed Hindu god Ganesha is proof that Indian ancients knew the secrets of cosmetic surgery, for example. Scientists were dismayed, and some did call for the session to be canceled, but their primary response then was still ridicule, rather than outrage. In February 2015, economics Nobel Laureate Amartya Sen stepped down as chancellor of Nalanda University in Bihar, protesting the “considerable government intervention” in academic decisions. That same month, gunmen attacked a left-wing politician called Govind Pansare and his wife; Pansare later died of his injuries. Then, in August, gunmen killed Malleshappa Kalburgi, a leading scholar and rationalist, at his home. “They were a threat, so they were eliminated,” says Tandon. The attacks shocked the academic community and ignited protests from writers, filmmakers and historians; many returned their national awards as a symbol of their dissent. Scientists were late to the table, which is not surprising, given that most of Indian science relies on government funds. Still, in October, three separate groups of scientists made statements — the total signatories now number nearly one thousand — protesting the government’s inaction against the acts of violence. (Bhargava returned his Padma Bhushan, one of the highest civilian awards in India, to the president.) “Other people were protesting and we scientists were keeping quiet, and all these things were going on around us,” says Tandon. “Keeping quiet just didn’t seem right.” The latest controversy is over the suicide of Rohith Vemula, a graduate student in life sciences at the University of Hyderabad. Vemula was a Dalit, a member of an oppressed caste in India. In July 2015, he and a group of other students had clashed with the student wing of the BJP on campus. University administrators then barred the students from public spaces on campus and withheld their fellowships, citing administrative delays as the reason. There have many other such reported incidents of discrimination against Dalit students over the past two years. Some level of discrimination has always existed in India, says Bhargava, but “now the discrimination has increased many-fold, has come out in the open and is clearly supported by the Government, as it is an integral part of the Hindutva philosophy of RSS and BJP.” On 17January, Vemula hung himself, saying in his suicide note, “my birth is my fatal accident.” His death has rocked academia, with unabated protests on the Hyderabad campus and elsewhere. Even before the incident, Tandon and others openly referred to Appa Rao Podile, the university’s vice chancellor, as the famed institution's first political appointee. Appa Rao has since left the university on indefinite leave. Not everyone agrees that scientists should join in the fray. “If you’re a social activist, if you’re a politician, if you’re a journalist with strong political view, no problem, you take part in the debate at whichever part of the spectrum you want to,” says , head of the Department of Biotechnology, the largest grant-making organization in the life sciences. “But I don't think it’s an issue which is a core scientific one.” He says the debate runs the risk of detracting scientists’ focus away from more pressing public health and scientific problems in the country. The protesters disagree, saying every scientist is a citizen first. “I signed [the petition] as a scientist but this is something I would have signed even if I was a professor of English,” says Sharath Ananthamurthy, a professor in the physics department at Bangalore University. “If we are quiet and if we let this kind of rubbish be propagated without strong dissent, a lie told a 100 times becomes a truth,” he says. “Talking about it, protesting, clarifying is the right thing.”