eChapters

Nanotechnology is a field of study which deals with materials at nano-scale like nanometer which is one billionth of a meter (1 nm = 10-9 meter). At nano-scale, physics, chemistry and biology converge towards the same principles and tools. Nanotechnology is domain in science and technology, which is multidisciplinary in nature and any scientist, engineer, medical doctor can do research on nanotechnology. Presently, it is more of a science and less of a technology because of a lack of proper tools for studying the properties of nano-material. Nano-particles (NPs) are materials that are small enough to fall within the nanometric range, with at least one of their dimensions being less than a hundred nanometres. This reduction in size brings about significant changes in their physical properties with respect to those observed in bulk materials. The presence of naturally occurring NPs is implicated in interplanetary and interstellar space (Hochella Jr, 2002) as well as our earth in which life from the beginning has evolved in their presence (Becker and Reitmeijer, 2006). Currently it is observed that NPs can be synthesized from many biological organisms including plants.

Through green revolution, we have developed high yielding varieties albeit with high nutrient requirements putting much more reliance on chemical fertilizers. The major challenge facing plant biology right now is to improve crop production and to feed an expanding world population. This is against a background of pressure on agricultural land use and climate change having negative impacts on growing conditions. The adverse effects of agriculture, and specifically fertilizer use, include damage to the environment, a large carbon footprint for the manufacture and use of agrochemicals, and the utilization of non-renewable resources. One solution is to increase the area of land for agriculture, as well as increasing production while maintaining the current rate of inputs; however, this is predicted to have substantial negative impacts on the environment (Tilman et al., 2002), is unsustainable in terms of phosphate use, and would have a huge economic footprint in terms of energy demands for nitrogenous fertilizer production. The challenge is to increase yield, decrease inputs, and improve resistance to abiotic and biotic stresses. Improving crop nutrient use efficiency ideally requires an understanding of the whole system, from the macro (agro-ecosystem) to the molecular level.

Nutrient supply is one of the major inputs for agricultural crop production in a sustainable manner. The factor productivity of inputs especially the fertilizers in agriculture was found to be in a declining phase during the last four decades. This had a detrimental effect on annual compound growth rate of major crops as wells on soil quality. The current status of nutrient use efficiency in different cropping system is low in case of major macro nutrients likes Nitrogen (30-50%) and Phosphorus (15-20%). Because 50-70% of the nitrogen applied using conventional fertilizers, with particle size dimensions greater than 100 nm, is lost to the soil due to leaching, nutrient utilization efficiency (NUE) by plants is low. Attempts to increase the NUE in conventional fertilizer formulations have thus far resulted in little success. On the other hand, the emerging nano strategies indicate that, due to the high surface area to volume ratio, nano fertilizers are expected to be far more effective than even polymer-coated conventional slow-release fertilizers. In this context, nanotechnology offers an important role in improving the nutrient use efficiency of agricultural systems.

In plants, mineral uptake is the process in which minerals enter the cellular material, typically following the same pathway as water. The most normal entrance portal for mineral uptake is through plant roots. Some mineral ions diffuse in-between the cells. In contrast to water, some minerals are actively taken up by plant cells. Mineral nutrient concentration in roots may be 10,000 times more than in surrounding soil. During transport throughout a plant, minerals can exit xylem and enter cells that require them. Mineral ions cross plasma membranes by a chemiosmotic mechanism. Plants absorb minerals in ionic form: nitrate (NO₃^-), phosphate (HPO₄^-) and potassium ions (K+); all have difficulty crossing a charged plasma membrane. It has long been known plants expend energy to actively take up and concentrate mineral ions. Proton pump hydrolyzes ATP to transport H⁺ ions out of cell; this sets up an electrochemical gradient that causes positive ions to flow into cells. Negative ions are carried across the plasma membrane in conjunction with H⁺ ions as H⁺ ions diffuse down their concentration gradient.

Nutrient use efficiency of crops is being improved through temporal and spatial management of the form and amount of nutrient inputs as being demonstrated by various agronomic practices. In addition, understanding of the genetic basis of nutrient efficiency would lead to the development of nutrient use efficient varieties thus reducing the application of nutrients. Earlier studies on genetics of nutrient use efficiency were limited as increasing productivity with heavy nutrient inputs was the main focus. But in the backdrop of environmental degradation due to the excessive nutrients and its impact in climate change, nutrient use efficiency in crops is need of the hour for sustainable and eco-friendly agriculture.

Low bioavailability of phosphorus (P) in soils is one of the major limiting factors influencing crop production throughout the world. Plants, however, are known to possess potential adaptive mechanisms at morphological, physiological, biochemical, and molecular levels to overcome P deficiency (Vance et al., 2003). Such adaptive mechanisms mainly include an increase in total root length and root hair growth (Bates and Lynch, 2000), enhanced organic acid (Singh and Pandey, 2003), acid phosphatase (Pandey, 2006) and ribonuclease (RNase) secretion into the rhizosphere (Hocking, 2001), increase in expression of proteins such as phosphatase, inorganic phosphate (Pi) transporter, RNase and phosphoenolpyruvate carboxylase (PEPcase) in plant tissues.

World population is expected to cross 8.5 billion by 2025 and it will be a gigantic task to produce enough to meet the future food demand by growing same set of crop varieties on anticipated reduced area. Most of the land that could be brought under cropping has been utilized with exception of some land in Sub-Saharan Africa and South America (Borlaug and Doswell, 1993). Therefore, it is warranted to produce more from less land, less water and less inputs which can be achieved by enhancing the efficiency of production system by devising more efficient crop management practices and developing input use efficient cultivars.

The diets of over two-thirds of the world’s population lack one or more essential mineral elements. This can be remedied through dietary diversification, mineral supplementation, food fortification, or increasing the concentrations and/or bioavailability of mineral elements in produce (biofortification) involving aspects of soil science, plant physiology and genetics underpinning crop biofortification strategies, as well as agronomic and genetic approaches currently taken to biofortify food crops with the mineral elements most commonly lacking in human diets: iron (Fe), zinc (Zn), copper (Cu), calcium (Ca), magnesium (Mg), iodine (I) and selenium (Se).

Under natural conditions, the largest source of labile carbon (C) inputs to the soil is root exudates (Bertin et al., 2003; Hutsch et al., 2002; Kuzyakov 2002). Roots exude a variety of low-molecular weight organic compounds, including sugars, amino acids, organic acids (Bertin et al., 2003), but also contain hormones, vitamins, amino compounds, phenolics and sugar phosphate esters (Uren, 2001). These compounds are rapidly metabolized; for example, Hutsch et al., (2002) found that 64–86% of maize root exudates were respired by soil microorganisms. The effect of root exudates depends on the distance that they can diffuse away from rhizoplane (Gupta and Mukerji, 2002).

Introduction
 
Climate change is a result from emission of greenhouse gases (e.g. CO₂, CH₄, N₂O, etc.) that will cause atmospheric warming (IPCC, 2007). Climate change may be due to natural internal processes or external forcing such as modulations of the solar cycles, volcanic eruptions, and persistent anthropogenic changes in the composition of the atmosphere or in land use. Human induced changes in atmosphere composition are a major concern. Burning of fossil fuels, like oil, coal, and natural gas is adding CO₂ to the atmosphere.

Introduction

The term nitrogen use efficiency, (NUE) is widely used in research to cover problems in use of N in crop production systems. It describes N input/output ratio at different scales starting from farm levels to regional levels. An analysis of of NUE is helpful to analyze possible options for improving NUE in different crops and cropping systems. NUE at crop scale may be defined as the ratio between the yield and the N uptake by the crop. This ratio is sometimes called as the physiological NUE or utilization efficiency. High NUE can be achieved by high harvest index and a high productivity of dry matter per unit N uptake. The second component of NUE is the ratio of plant N uptake to the potentially available N. This ratio is called uptake efficiency or available N use efficiency. Enhancing the uptake efficiency of the crop is possible through enhancing the physiological uptake efficiency of the roots, enhancing root length density and matching the N supply and demand of a particular crop.

Introduction

The soil is the largest terrestrial pool of organic carbon, about 1150 Pg (1Pg = 10¹⁵ g) compared with about 700 Pg in the atmosphere and 600 Pg in land biota (Lal and Kimble,1997). Organic carbon level of soils reaches a fixed equilibrium that is determined by a number of interacting factors such as precipitation, temperature, soil type, tillage, cropping systems, fertilizers, the type and quantity of crop residues returned to soil, and the method of residues management. In the temperate climate, it may take about 50 years for the organic carbon of soils to reach a new equilibrium level following a change in management. However, this period is much shorter in a semiarid and arid climate and also in tropical climate like India.

Introduction

Organic matter in soil is the key to soil health. SOM improves many physical, chemical, and biological characteristics of the soil, including water holding capacity, cation exchange capacity, pH, buffering capacity, and chelating of micronutrients. Furthermore, well decomposed SOM improves soil structure by increasing aggregation, enhances biological activities in the soil, slowly releases nutrients, and suppresses some diseases. A loss of SOM can lead to soil erosion, loss of fertility, compaction, and general land degradation.

Introduction

Our soil resource is generally taken for granted for many uses. Most people don’t realize the importance of the resource and that it is fundamental for farming/agriculture. Without high quality soils, agriculture production cannot be achieved on a sustainable basis to meet ever growing demand. Thus, conservation agricultural practices are capable of improving soil health by increasing organic carbon, aggregation, improving infiltration and minimizing erosion losses.

Introduction

Use of FYM, crop residues, leaf fall, root deposition etc. has been part and parcel in agriculture. These material undergoes microbial decay over the time slowly and the major portion of it finds way back to the atmosphere. Not only that, residue burning traditionally provides a fast way to clear the agricultural field of residual biomass, facilitating further land preparation and planting. However, in addition to the loss of valuable biomass and nutrients, biomass burning leads to release of toxic gases including GHGs.

According to Planning Commission Report (2014), India generates about 62 million tons of municipal solid wastes (MSW) every year from urban cities. There has been a significant increase in municipal solid waste generation in India in the last few decades. This is largely due to rapid population growth and economic development in the country (Annepu, 2012). Solid waste management (SWM) has become a major environmental issue because of serious environmental implications like global warming (through green house gases emission) and contamination of toxic pollutants (like heavy metals) in surface and groundwater bodies. Solid waste management is one of the essential services to be provided by municipal authorities in the country to keep urban areas clean. Out of total waste generated in India, only 12.45% waste is scientifically processed and rest is disposed in open dumps (CPCB Report, 2013). Although, incineration of solid wastes is being followed in many places for energy production, composting is considered most environment friendly method of SWM as it promotes recycling of nutrients in crop production.

Fertility of a soil can be assessed by analyzing various available nutrients present in the soil. Fertilizer recommendations for various crops and cropping sequences can be made on the basis of fertility status of a soil. Besides this, problematic soil can be ameliorated on the basis of soil test values. Among the various steps of soil testing programmes, soil sampling is the most vital step.

Soil organisms play vital role in agri-ecosystem processes such as nutrient cycling, soil detoxification and organic matter decomposition. They also influence water infiltration by improving soil porosity through production of polysaccharides. Rhizosphere microorganisms help plant to acquire macro and micronutrients, produce phytohormones for better crop establishment. Soil microbes process organic matter to provide a balance of minerals and nutrients which are utilized by plants to achieve healthy and vigorous growth. Microbes also colonize on plants parts and offers protection by excluding many plant pathogens. They are the basic indicators of soil fertility and are responsible for maintaining a hospitable environment for crop growth.

A new analytical technique called inductively coupled plasma emission spectroscopy has been used for simultaneous multi element analysis of biological materials and soils (Hou and Jones 2000; Wikipedia, 2010; Bradford and Cook, 1997). This technique offers advantages over AAS and other multi-element methods because matrix problems are eliminated or minimized through use of the high temperature argon plasma. Apart from multi- element capability at all concentration levels, plasmas are noted for relative freedom from chemical and ionization interferences that are common with AAS, and detection limits are equal to or better than AAS, depending on the element to be analyzed. Elements such as Al, P, S and B, which are either poorly measured at low concentrations or not possible by AAS, are readily determined with higher sensitivity by ICP.

Introduction

After the Second World War, isotopes have become available in sufficient quantities for use in different fields of scientific research. There has been tremendous increase in the number and scope of applications of these new tools and agricultural research is no exception. During the last quarter of a century, the use of isotopes and radiations has become one of the important tools in the solution of practical problems in the area of soil-plant nutritional studies throughout the world. In India, these studies were initiated as early as 1955 with the establishment of the Radiotracer Laboratory at the Indian Agricultural Research Institute, New Delhi. The use of these nuclear tools got further fillip in our country with the establishment of the Nuclear Research Laboratory at the Indian Agricultural Research Institute, New Delhi in 1968 as a UNDP Project on Nuclear Research in Agriculture, operated by the Joint FAO/IAEA division of the International Atomic Energy Agency. Also, the agriculture division of Bhabha Atomic Research Centre, Mumbai and the special radioisotope laboratories established by several agricultural universities had made significant contributions to the use of isotopes and radiations in agricultural research.

Knowledge of structure is a basic element of biological research. Understanding structures of various degrees of complexity contributes to a better understanding of function, ontogenetic and physiologic processes, as well as phylogenetic relationships. In biological sciences, ultrastructure refers to the nanostructure of a biological specimen, such as a cell, tissue, or organ, at scales smaller than can be viewed with light microscopy. Electron microscopy (EM) has a great impact on our knowledge and understanding of ultrastructure.

Ever since industrial revolution altered the whole gamut of economic activity at least two hundred years ago, the path of economic growth including its modified form economic development had appeared unending and limitless. The whole focus of economic activity is to produce mere goods and services for use by the mankind so that life could be more comfortable and satisfying. Increasing population and increased needs of more goods and service was also seen as a hindrance or limitation in the march towards economic growth and development.

AIR

Air is a non-homogenous mixture of gases, solid particles, and liquids; It consists of gases and particles with small settling velocity that exhibit stability in a gravitational field. Atmosphere has four major layers Troposphere from 0-17km., Stratosphere from 17-50km., Mesosphere from 50-90 km. and Ionosphere is from 90-100 km. (95% of the air by weight is contained in the Troposphere i.e. from 0-17 km).

AIR POLLUTION FROM AUTO EXHAUST

Motor vehicles are the major source of a number of pollutants, in particular carbon monoxide (CO),nitrogen oxides (NOx), unburnt hydrocarbons (HC),ozone (O3) and other photo chemical oxidants and lead (Pb) and, in smaller proportions Total Suspended Particulate Matter (TSPM), sulphur dioxide (SO2) and volatile organic compounds.

Particulate Matter

Anthropogenic emissions of particulate matter include fossil fuel (diesel and petrol) combustion from mobile and stationary sources (Rogge et. al., 1993a-c), biomass burning (Forest fires, landfills, agricultural activities and incinerators) (Oros and Simoneit, 1999) natural gas (Rogee et. al., 1993c), wood (McDonald et. al., 2000) and coal combustion (Mastral and Callen, 2000).

Effect of Air Pollutants on Plants
 
Elements of those air pollutants which accumulate in plants (S from SO2, heavy metals from anthropogenic emissions etc.) may be used for specific bio-indication of possible effects caused by these pollutants, and for mapping their spatial and temporal distribution. Measuring accumulated components in plants rather than directly in the environment, provides the dual advantages of an integrated rather than a momentary value, and of a biological content rather than a mere concentration (Stocker and Gluch, 1990).

The response of plants to air pollution can be understood by analyzing the physiological and biochemical parameters of plants.

Physiological Parameters

The epidermal cells are the first to interact with the air pollutants and also lack chloroplast. Epidermal cells hence cannot remove excess sulphur through the production and release of H2S. Damage to plants by air pollutants depends upon the amount of pollutants entering the cells and their reactivity with cellular constituents. Plants regulate the entry of gaseous molecules through stomatal movement thereby affecting the photosynthesis and transpiration. Response of plants to gaseous pollutants varies from species to species. This is due to differences in the stomatal conductance, aperture size and permeability of plasma membrane (Yunus et al., 1996).

Atmosphere serves as the medium through which pollutants are transported and dispersed. While being transported, the pollutants undergo chemical reactions, which may be lethal or scavenged by chemical or physical process/method. But it all exclusively depends upon the meteorological conditions (Lee et .al, 1994). Historic air pollution episodes reveal that atmospheric conditions influence the pollutant concentrations as well as their toxicity (Goldsmith & Friberg, 1976; Wichmann et.al, 1989 and Pope et.al, 1992). However, the location, duration of release, height as well as the pollutant concentrations are also important, which effect the secondary pollutant transformation under the influence of meteorological conditions, but the atmospheric behavior is independent of their sources (Holzworth, 1974).

Metals

Metals are ubiquitous in the modern industrialized environment. Heavy metals like cadmium, iron, molybdenum, lead, nickel, tin and zinc are present in the environment in trace concentrations. These metals are universally present in soil, water, air and biota (Freedman, 1995). Global anthropogenic heavy metal inputs to ecosystem through air, water and soil have increased substantially world wide over last century (Nriagu, 1996).

Through the sharing of experience of developed countries, which faced the massive health problem due to vehicular pollution in the past and remedial measures adopted by them, it is needed to avoid mistakes made in the past and instead introduce effective measures for the future to reduce or confine the damage that has already been incurred. A progressive policy of motor vehicle emission control strategy, which may be more feasible/affordable, has to be adopted for solving immediate air pollution problems. Uncontrolled growth of vehicular fleet and its emission is taking place in the urban areas, which must be controlled/regulated in order to prevent future disaster. Because of economic development and speed of motorization expected over next decades this problem will become more vulnerable and even greater, If control measure are not adopted timely. It is suggested that planning must begin to provide alternatives to the motor vehicles and to reduce emission of the vehicles. The country without high capital resources will face challenging problems for evolving control strategy that will be acceptable both economically and socially.

Urban Air Pollution and Its Impact on Roadside Plants
Urban Air Pollution

Modern industrial society produces a large number of gases and particles in quantities to harm human, plant or animal life. The amount of pollutants released to the atmosphere by fixed or mobile anthropogenic sources is generally associated with the levels of economic activity. Deterioration of air quality is a major environmental problem in many urban centers in both developed and developing countries. Automobiles constitute a major source of air pollution in the urban areas. Motor vehicle emissions result from fuel combustion or evaporation. The most common types of transport fuel are gasoline and diesel. CO₂ and water vapors are the main products of the combustion, emitted in vehicle exhaust. The major pollutants emitted from the vehicles are particulate matter (suspended fine and ultra fine), sulphur dioxide, oxides of nitrogen, carbon monoxide and metals.

Plants play an important role in maintaining ecological balance by actively participating in the cycling of nutrients and gases like carbon dioxide, oxygen and air pollutants. Sensitivity and responses of plants to air pollutants is variable. Some plants are sensitive and act as bio indicators of air pollution (Kozhouharov et. al. 1985, Guderian, 1998). Others which are tolerant may act as sink to air pollutants. However this aspect needs more investigation for their use as indicators of air pollutants and in abatement of air pollution.

Air

Estimation of Total Suspended Particulate Matter (TSPM) and Respirable Suspended Particulate Matter (RSPM)

Requirements
Instrument

High Volume Sampler (HVS) APM 415-411 (Envirotech Instrument India), Respirable Dust Sampler (RDS) APM 451 (Envirotech Instrument India) with midget impinger containing absorbing solution were used.

Pollution is continuously increasing in India. To control ambient air pollution CPCB has prescribed National Ambient Air Quality Standards

True/False

Q.1.    Statistics in singular is used to denote a subject (branch) of science.
Q.2.    Statistics in plural is used to denote “data or methods”
Q.3.    Statistics is defined as a science of collection, compilation, analysis and interpretation of numerical data.
Q.4.    Statistics can be used for two major purposes: descriptive and infe-rential.

True/False
 
Q.1.    The set of observations or measurements collected on specific characteristics from each item (individual) constitutes data.
Q.2.    Each characteristic that is measured or observed, varies from item to item and is called “Variable”.
Q.3.    “Blood type”, “stage of disease” and “weight” observed on a group of cancer patients, are three distinct variables.
Q.4.    A variable that can be expressed in numbers such as age, height, blood pressure, is said to be “Quantitative variable”.

True/False

Q.1.    A set containing all possible outcome of a trial in a study is known as “Sample space”.
Q.2.    If we are interested in observing the blood type of a child born in a hospital then sample space may be a set S is of the form S = {A, B, AB, O}.
Q.3.    If outcomes are continuous in nature, the sample space is specified as an interval that contains all possible outcome values.
Q.4.    When the occurrence of one event excludes the occurrence of other events, the events are said to be “Mutually exclusive events”.
Q.5.    In case of testing the type of blood of a newly born baby in a hospital, the blood types A, B, AB, O or gender (male, female) are exclusive events.

True/False

Q.1.    The set of all possible outcomes of a variable along with the frequency (the number of occurrence) of each outcome or a group of outcome is called “Frequency Distribution”.
Q.2.    The frequency of an occurrence of each outcome of a trail divided by total frequency is known as “Relative frequency” of the outcome.
Q.3.    The distribution of total probability “1” into probabilities of occurrence of each outcome of a trial, is known as probability distribution of the outcome.

True/False

Q.1.    Collectivity (totality) of all sampling units is known as the “Population” and population size is denoted by “N”.
Q.2.    A list of all sampling units with their identification is known as “Sampling frame”. For example a list of all newly-born children in maternity home during a period of three months with specification of their sex, weight, name of their parents, their permanent address, etc. is known as sampling frame.
Q.3.    A function of all sampling units in the population is known as population parameter or population constant.

True/False

Q.1.    The process of knowing all the relevant information from the known sample to the unknown “Population parameter” is known as “Statistical inference.”
Q.2.    The method of estimating the unknown parameter of the population on the basis of known sample values is known “Estimation method.”
Q.3.    The “Point estimation and Interval estimation” are the two methods of estimating the unknown parameters of the population.

True/False

Q.1.    A hypothesis that sets the fundamental objective of scientific study is called the “Research hypothesis”.
Q.2.     A statistical assumption or statement about the unknown parameters of a population is known as Statistical hypothesis.

True/False

Q.1.    According to Prof. RA Fisher “ANOVA” is the separation of variance assignable to one group of causes from the variance assignable to other group of causes.
Q.2.    The basic purpose of ANOVA technique is to test the equality (homogeneity) of several population means from the same 
experiment.

True/False

Q.1.    Qualitative or categorical data are frequently collected in medical investigation.
Q.2.    Qualitative variables may be, e.g. sex, blood type, treatment, groups, classification of exposure or disease and patients survived or not.
Q.3.    Qualitative variables include the grouped quantitative variables such as age groups of mothers, pre term babies, birth weight groups, 
hypertensive or normotensive etc.

True/False

Q.1.    The most fundamental assumption for “Parametric inference” is that the random sample drawn is from “Normal” population.
Q.2.    The most fundamental assumption of “Non-parametric” test is that the random sample drawn is from “Continuous distribution”
Q.3.    The standard parametric methods are applicable for “Estimating the parameter” as well as for “Testing the hypothesis” about the parameters.
Q.4.    Non-parametric methods, are applicable only for testing the hypothesis about  distribution but not applicable for estimation purpose of parameter.

True/False

Q.1.    Two independent random variables (X,Y) are always uncorrelated but reverse may not be true

True/False

Q.1.    The purpose of most medical research is to identify the causes of disease and search out the ways to prevent or cure them.
Q.2.    Now a day, epidemiology has become a basic science for public health
Q.3.    The studies of diagnostics therapeutic and prognostic procedures have successfully incorporated into growing stream of “Clinical Epidemiology”.

True/False

Q.1.    In clinical practice and in public health, the objective is to find better ways to ‘prevent,  diagnose and treat disease’.
Q.2.    Among all research designs, experimental study designs are the most reliable and  ideal designs to evaluate the ‘effectiveness or value’ of interventions (like drugs,  medication etc.) for human disease and disabilities.

True /False

Q.1.    A diagnostic test enables the doctors to reach at a decision whether the patient is suffering from a particular disease or not.
Q.2.    The recent developments in the field by biotechnology have led to the development of many new medical tests.
Q.3.    The general principles in designing and conduct diagnostic test studies are not known well.

True/False

Q.1.    In many epidemiological studies with substantial follow up time, it is very often an interest to study the time taken for a particular event to occur.
Q.2.    The time taken for death or graft failure since transplant, time taken for relapse after treatment, time to death after treatment etc. are examples for survival time.

True/False

Q.1.    The accuracy of the measurement refers to how close the measured value is to the true value.
Q.2.    The precision refers to how close a set or group of measurements are together.
Q.3.    If the processes of measurement are repeated under identical condition, then precision explains that up to what extent these repeated values are reliable.