Quantification of Compound and Cascading Hydroclimatic Extreme Events

Compound and cascading hydroclimatic extreme events have garnered much attention in recent studies. The combined effects of interconnected extremes can cause widespread damage, with a higher potential impact than individual extremes. Both anthropogenic warming and natural climate variability affect these extremes, which is why detecting past extreme events, understanding the underlying mechanisms, and assessing their future impacts can aid in mitigation efforts to reduce their overall impact. However, thus far, identifying such events is oversimplified and the propagation of their impact as cascades from the physical to human systems remains partly explored. The overreaching goal of this thesis is to develop robust methodologies to quantify the compound and cascading extreme events, such as drought and heatwaves, extreme precipitation and atmospheric rivers, extreme heat and humidity, and flash droughts in the past and future climate. A suite of advanced statistical methods, system dynamics, and causality approaches are implemented to achieve the research goal. This thesis consists of ten chapters, and the objective of each chapter are summarized as follows. (1) Chapter 1 provides a brief introduction and examples of various compound and cascading hydroclimatic extremes. (2) Chapter 2 provides a perspective of drought indices and highlights the challenges in the context of climate change. (3) The objective of chapter 3- chapter 5 is to quantify the compound drought and heatwave characteristics (frequency, duration, and severity) and investigate their association with natural climate variability, anthropogenic warming, land-climate feedback, and background aridity across the globe. (4) Chapter 6 is dedicated to quantifying the future changes in the potential impact of heat-stress (combination of extreme heat and humidity) on the human population. (5) The cascading influence of meteorological forcing on the moisture advection processes associated with extreme precipitation related to atmospheric rivers is discussed in chapter 7. (6) The objective of chapter 8 is to investigate and quantify the compound and cascading influence of different spatial drivers, such as precipitation, temperature, surface-energy portioning, soil moisture-temperature coupling strength, and vapor pressure deficit on the evolution and intensification of global flash droughts. (7) Chapter 9 proposes a methodology to quantify the compound and cascading effects in a dry-hot event network using a system dynamics approach. Finally, the conclusion and recommendations are provided in chapter 10

Plant diversity of Gadchiroli district of Maharashtra, India: a brief survey

A qualitative survey was carried out during 2005- 2010 of all indigenous and naturalized plants of Gadchiroli district, Maharashtra, India. There are 237 species belonging to 184 genera and 73 families which are listed in this paper. Out of 73 families listed, 63 belong to dicotyledonae and 10 belong to monocotyledonae. Dominant families were Fabaceae (21 genera), Acanthaceae (12 genera) followed by Asteracece (9 genera). The nomenclature system followed in this paper is up to date. Three plants (1.63%) listed in this paper come under Vulnerable (VU) and two (1.09%) comes under Lower Risk (LR) categories. Eleven genera (5.98%) are reported to be endemic to Maharashtra state of India. Only one plant species (Agave americana var. americana) was not native of the area and is cultivated. Voucher specimens of the representative plants are submitted at Medicinal Plants Conservation Center (MPCC), Pune, Maharashtra, and the voucher number is provided along with names of plants

Underground and Opencast Coal Mining Methods in India: A Comparative Assessment

Coal is one of the most essential resources of a country. It is widely used for power generation and as a raw material in the industries. India ranks third in coal production. However, the country has to import coal in order to meet the rising demand for coal.  In India, coal mining is conducted using two methods: underground and opencast methods. The underground method is suitable for extraction of deeper coal seams, whereas opencast method is suitable for shallow coal seams. However, due to less production cost, mechanisation, and less wastage, opencast method dominates in India (93.26% of the total production in the financial year 2016-17). Underground coal production in India shows a declining trend, and several underground mines are closed every year. However, 60% of the total coal production in the world is from underground mines, whereas in India it constitutes only 6.74% in the financial year 2016-17. Thus, underground coal production in India is declining. Due to the large scale extraction of near-surface coal resources by opencast mining, near-surface coal resources will be depleted in future. Moreover, opencast mining has several environmental impacts, which is ignored keeping in view the colossal coal demand of the country.  Thus, coal production in India is facing a crisis concerning the production method, environmental impacts and future demand for coal. With this background, this paper has been prepared on the basis of data collected from reports, research papers, and articles. Here, we make an attempt to compare both the mining methods with respect to advantages, disadvantages, environmental impact and feasibility. We also discuss the current and future trends of coal production using both the mining methods. Measures to sustain coal production in India are discussed in the conclusion part

Polyamidoamine Dendrimer Nanoparticle Cytotoxicity, Oxidative Stress, Caspase Activation and Infammatory Response: Experimental Observation and Numerical Simulation

Mechanisms underlying the in vitro cytotoxicity of Polyamidoamine nano-dendrimers in human keratinocytes are explored. Previous studies demonstrated a systematic, dendrimer-generation-dependent cytotoxicity, oxidative stress, and genotoxicity. The emerging picture is of dendrimer endocytosis, endosomal rupture and subsequent mitochondrial attack and cell death. To understand the underlying mechanisms, the evolution of reactive oxygen species, intracellular glutathione, caspase activation, mitochondrial membrane potential decay, and inflammatory responses have been examined. Early-stage responses are associated with endosomal encapsulation, later-stage with mitochondrial attack. In all cases, the magnitude and evolution of responses depend on dendrimer generation and dose. The early-stage response is modelled using a rate equation approach, qualitatively reproducing the time, dose and generation dependences, using only two variable parameters. The dependence of the response on the nanoparticle physicochemical properties can thus be separated from internal cellular parameters, and responses can be quantified in terms of rate constants rather than commonly employed effective concentrations