eChapters

Each optic vesicle grows outwardly until it comes into contact with the surface ectoderm. At this point, the optic vesicle induces the overlying ectoderm to thicken and to invaginate against the optic vesicle. The optic vesicle becomes concave and convert into double walled optic cup. The attachment of optic cup to the brain is called optic stalk. The space between inner and outer walls disappears as they come opposed. Since invagination of optic cup occurs at the ventral margin of the vesicle a groove is formed in ventral rim of the cup which extends along the ventral surface of the optic stalk (choroid fissure) which closes at the end of embryonic period. The groove and the notch in the optic cup are referred to collectively as the optic fissure. The optic fissure begins to close by fusion of its edges soon after the optic cup is completely formed. While it is open, the fissure allows a branch of the choroid artery (Hyaloid artery) into the cavity of the optic cup.

With the development of the optic cup the lens placode invaginates into rim of the optic vesicle and forms lens vesicle. The lens vesicle loses contact with the surface ectoderm and positioned at the opening of the optic cup and forms lens.

The sense organs in an insect body are distributed on different parts and respond to a given stimulus such as light, sound, touch, chemicals etc. The sense organs may be classified as • Visual organs (or) photoreceptors • Auditory organs (or) organs of hearing

• Chemoreceptors which respond to chemicals

• Tacticle receptors which respond to touch

• Gustatory receptors which respond to taste.

Photoreceptors

Light is perceived by insects through a number of different sense organs and these are the organs that react with light and useful for vision. These are of different types, but most important are the compound eyes.

Compound eyes

The highly specialized organs that receive physical and chemical stimuli from the environment and various body parts, and transform them into stimuli are called sense organs or sensory receptors. These organs are closely associated with nervous system. The physical stimuli such as change of heat, light intensity and quality, acoustical stimuli and chemical stimuli like hear, taste, smell, touch, lateral line etc are received by the sense organs such as ear, eye, nose and others. These are more prominent sense organs. Less obvious ones in fishes are sensory crypts and papillae, ampullae of Lorenzini and Savi.

The crustaceans have various sense organs whose action are mediated through the nervous system. Crustacean antennae are important sites for the reception of environmental information, mainly chemical, and aesthetases, the olfactory hairs on the first pair, are usually well developed. The aesthetases help not only in locating food but also in recognizing other individuals and their sexual state.  The frequent grooming of the antennae by many decapods prevents fouling of the receptor sites (Bauer, 1971).

One of the major goals in agricultural crop management is to achieve maximum yield with minimum investment while maintaining a good quality of the crop produce. Crop infestation due to insects, diseases, and weeds are some of the major factors responsible for loss in crop yield. Further, an efficient Precision Agriculture Crop Management System is one, which is capable of precisely detecting the crop yield indicators (or crop health parameters) at an early stage and can predict the yield at any point of time of the crop cycle.

Sensor is a physical device used to detect manifestations or variations in a process value and collect data in real time assessment mode for measuring and predicting system/device performance and finally analyzing it to attain a specific task or application. Sensor technology is now-a-days used for interdisciplinary applications for data collection, system analysis and monitoring.

1. Introduction
Precision farming, often referred to as precision agriculture, is an advanced agricultural management approach that leverages technology and data-driven strategies to optimize various aspects of farming operations. At its core, precision farming involves the precise measurement and control of variables like soil conditions, crop growth and environmental factors to enhance productivity, sustainability and resource efficiency. This approach encompasses use of a wide range of automated technologies, including Global Positioning System (GPS), Geographic Information Systems (GIS), remote sensing, sensor networks and automated machinery.
The significance of precision farming lies in its potential to revolutionize agriculture by addressing sustainability and conservation of resources. Precision farming is able to tailor farming practices to specific field conditions. This sitespecific management approach minimizes resource wastage, incumbent costs and environmental hazards. It enhances crop management through real-time monitoring and data analysis. By the use of GPS fitted automated machinery, drones and robotic harvesters and advanced decision support system labour costs are reduced and efficiency is increased (Gebbers and Adamchuk, 2010).By employing soil sensors, and satellite imagery, farmers can gain valuable insights of soil moisture, nutrient levels and pest infestations which helps in irrigation scheduling and adequate fertilizer application (Srinivasan et al., 2019). In contemporary agriculture, the need for sensor-based approaches in soil management has become increasingly apparent. These approaches harness cuttingedge technology and data-driven solutions to optimize soil health, crop production and resource utilization. One of the primary advantages of sensor-based approaches is their ability to monitor soil moisture levels. Soil moisture sensors, such as those based on time-domain reflectometry (TDR) or capacitance technology, provide continuous data on soil moisture content at different depths (Dzikiti et al., 2012). In addition to monitoring moisture and nutrients, sensors can assess other vital soil parameters. Soil pH sensors help maintain the optimal pH level for crop growth, as soil pH can affect nutrient availability. Compaction sensors identify areas of soil compaction, allowing for targeted tillage practices to alleviate compaction and improve root growth. These are just a few examples of how physical parameter sensors can address soil health challenges, as documented in studies by Marchetti et al. (2018) which emphasizes the role of sensors in mitigating soil erosion. Chemical parameters sensors like soil nutrient sensors, such as ion-selective electrodes, can measure key nutrients like nitrogen, phosphorus and potassium. This information enables farmers to tailor their fertilization practices with pinpoint accuracy through variable rate technology (VRT) (Zhao et al., 2018). Moreover, sensor data can be integrated with Geographic Information Systems (GIS) and global positioning systems (GPS) to create detailed soil maps, aiding in sitespecific management strategies.

Sensor is a device which converts environmental parameters into electrical signals. In the broad definition, it is a device, module, machine, or subsystem which is designed to detect events or changes in the environment and send the information to other electronics components. An actuator is a component of a machine which is responsible for moving and controlling a system. A microcontroller is a small computer on a single metal-oxide-semiconductor (MOS) integrated circuit (IC) chip. This chapter explains the microcontroller development boards and their components along with the classifications of sensors and actuators.

4.1 Classification of Sensors

The sensors can be classified on the basis of different areas as follows-

i. Classification based on Application

Sensors are chosen on the basis of application where they need to be implemented like Industrial process control, measurement and automation, Automobiles, Consumer electronics, Aircraft, Medical products etc. As with change in application the selection criteria changes, so application needs to be considered.

SENSORY EVALUATION OF FOOD

When the quality of a food is judged or evaluated by the senses (taste, smell, sight, touch and hearing), it is said to be a sensory evaluation. Since food is prepared for the primary purpose of being eaten and enjoyed through the senses, sensory evaluation is most appropriate. No machine has yet been devised that can totally substitute for the human senses in evaluating the quality of human food. However, the human instrument used in sensory evaluation is very complex and many problems need to be managed as data are collected and analysed. Computers are generally used to analyse data from sensory evaluations and may also be used to collect information firsthand.

Flavour perceptions are difficult to characterise verbally, for example, think about how a strawberry tastes, then try to describe it some one else. In food research small groups of trained individuals called juding panels or sensory panels are commonly used to determine differences among food samples. These panels often consist of from 5 to 15 individuals who have had training and experience in testing the particular food products being evaluated.

Principles
The quality of foods can be defined as the ‘composite’ of those ‘characteristics’ that differentiate individual unit of a product and have significance in determining the degree of acceptability of that unit by the consumer. The overall quality refers to technological, physiological, chemical, microbiological, nutritional; and sensory parameters to achieve the wholesome food. Sensory quality attributes such as taste, colour, texture, flavour and overall quality of any food products were evaluated by 9- point Hedonic rating test is used for the purpose of evaluation. This test measures the consumer’s acceptability.

1. INTRODUCTION AND IMPORTANCE

Sensory evaluation is one of the important methods of evaluation of the quality of food. Without the sensory evaluation of a product whether it is fresh or processed, it cannot be launched in the market. All the other methods like physical, chemical and microbiological fails for the product development if sensory evaluation is ignored as the final acceptance can come from the sensory evaluation only. So sensory evaluation has got an upper edge as compared to the other methods of food quality evaluation. However, a collective approach of quality evaluation of a product that includes the physical, chemical, microbiological and sensory evaluation is the most acceptable approach today.

In the past, human sensory perception had been the only mean of assessment of product quality as illustrated by the classical examples of cooks who knew how to mask the off-notes long before the microbial assessment of quality came into existence. Everybody relied on the sensory evaluation of food as a criterion of quality assessment. In the past, even the kings depended upon “tasters” to assure that the food was suitable for their consumption in the past. The role of sensory organs in sensory evaluation of food is shown in Table 1. But later on, with the development of instrumentation, sensory analysis was overlooked and the instrumental methods were preferred as they were supposed to provide absolute measures of quality. Consequently, the product quality was traditionally determined by physical, chemical and microbiological criteria with the assumption that the products meeting the prescribed specifications in the above parameters would automatically meet the desired sensory quality. However, soon it was realized that without sensory evaluation, the acceptability of a product cannot be determined.

Introduction

Quality is the ultimate criterion of the desirability of any food product to the consumer. Overall quality depends on quantity, nutritional and other hidden attributes along with sensory quality. Sensory quality is of great importance to both processors and consumers, since it attracts consumers; it satisfies consumers’ aesthetics and gustatory sense. Sensory quality is the combination of sensory senses of perception responsible for choosing and eating a food.

According to Institute of Food Technologists and the American Society for Testing and Materials, sensory evaluation is a scientific method used to evoke measure, analyze, and explain those responses to products as perceived through different senses like sense of sight, smell, touch, taste, and hearing (Stone and Sidel, 2004). Sensory evaluation gives a general rule for the preparation and serving of samples under controlled conditions so that unfair decisions are minimized. People for sensory evaluation are often placed in individual test booths so that the judgments they give are true and do not reflect the opinions of those around them.

Samples with random numbers are given to the evaluators so that they do not form judgments based upon labels, but rather on their sensory experiences. Products may be given in different orders to each evaluator to help measure and to ensure internal validity by controlling the potential confounds created by sequence and order effects. To control unwanted variation and to improve test precision, standard procedures may be established for sample temperature, volume, and spacing in time, as needed.

Sensory evaluation or testing is a quantitative science in which numerical data are collected to establish lawful and specific relationships between product characteristics and human perception. Sensory methods draw heavily from the techniques of behavioural research in observing and quantifying human responses. For example, we can assess the proportion of times people are able to discriminate small product changes or the proportion of a group that expresses liking for one product over another. Another example is having people generate numerical responses reflecting their perception of products taste and smell.

Sensitivity-Threshold tests Sensitivity tests are conducted to assess the ability of individuals to detect different tastes, odors and feel the presence of specific factors in.

.0. Objectives

• To recognize different types of sentences and text
• To demonstrate the correct structure of sentence and text
• To demonstrate the method to transform the tense of sentence
• To idenitify the function of teaching verb tense

2.0. Basic Sentence Structure

2.1. Subject and Predicate

In the following short sentence.

INTRODUCTION

A mixture is a combination of two or more elements or compounds in any proportion so that the components do not lose their identity. Most materials in our world are mixtures and very few materials are pure substances. Foods are complex mixtures of compounds and the extraction or separation of food components is fundamental for the preparation of ingredients to be used in other processes. Separations usually aim to remove specific components in order to increase the added value of the products, which may be the extracted component, the residue or both. Purposes include cleaning, sorting and grading operations, extraction and purification of fractions such as sugar solutions or vegetable oils, recovery of valuable components such as enzymes or flavour compounds, or removal of undesirable components such as microorganisms, agricultural residues or radionuclides. For example, cooking oils from oilseeds or gelatin from connective tissue; or for retrieval of high value compounds, such as enzymes (e.g. papain from papaya for meat tenderisation or rennet from calf stomachs for cheese making). Other types of separation methods are used to sort foods by separating them into classes based on size, colour or shape and to clean them by separating contaminating materials.

Agarose gel electrophoresis is used to resolve DNA fragments on the basis of their molecular weight. it will be visulaized by exposing to UV light. Principle: As the phosphate backbone of DNA is negatively charged, the basic principle is the migration of DNA molecules from negative (cathode) to positive (anode) charge under constant electric field. The DNA will be separated mainly on the basis of their size, DNA conformation, concentration of gel and voltage. The distance travelled by the DNA molecules tell us about their molecular weight, where smaller DNA fragments will travel farther than the larger ones due to constant mass/charge ratio of DNA. The separated DNA molecules will be then visualised under UV light in gel documentation system after staining with suitable dye.

Objective: To estimate qualitatively various chlorophyll fractions

Materials Required: Leaf material, acetone, petroleum ether, distilled water, methyl alcohol, potassium hydroxide, diethyl ether, separating funnels, stand beakers and conical flasks.

Principle: In biological systems the molecule absorbing radiant energy in the visible range is referred as a pigment. To the human eye these pigments are coloured: chlorophyll is green, carotenoids are red or yellow, xanthophylls is yellow and phytochrone is blue. These pigments are complex molecules. Chlorophylls are the most important pigments active in photosynthesis. At least nine different types of chlorophylls are known – chlorophyll a, b, c, d, e bacteriochlorophylls a and b and chlorobium chlorophylls 650 and 660. Chl a and chl b are best known pigments. In addition to chlorophyll, carotenoids, xanthophylls etc. Are also present as accessory pigments. The chlorophylls are directly involved in photosynthetic electron transport the other pigments serve as accessory pigments and they also serve the purpose of light harvesting.

There are different organic molecules are soluble in different organic solutions, however, their solubility is differential in different chemicals. Based on the nature the chlorophyll pigments can be separated and identified.

The various unit operations of food process engineering applied to solve the problem of changing the compositions of solutions, mixture and solids. Often these operations must be conducted on large scale to meet the demands of a large manufacturing plant. In food processes engineering these operations are often referred to as separation / concentration / extraction / purification process. Usually these operations are directed towards separating substances into its component parts or concentrating a particular substance from another.

Acts especially on the portal system, with venous congestion. Stasis and thereby ptosis of viscera and weariness and misery. Weakness, yellow complexion, bearing-down sensation, especially in women, upon whose organism it has most pronounced effect. Pains extend down to back, chills easily. Tendency to abortion. Hot flashes at menopause with weakness and perspiration. Upward tendency of its symptoms. Easy fainting/ Ball" sensation in inner parts. Sepia acts best on brunettes. All pains are from below up. One of the most important uterine remedies. Tubercular patients with chronic hepatic troubles and uterine reflexes. Feels cold even in warm room.

The most important indications of Sepia are in the problems of women relating to the uterus. It has been called the best uterine remedy available. The patient feels that all her internal organs would come out of the pelvic region. She has to sit with legs crossed to relieve this feeling. Sepia is a chronic remedy. It can take care of long standing problems.

It is caused by the entry of the bacteria in to the blood.

The pathogenetic bacteria or their products usually enter the blood through some break in the skin or mucous membrane. Although sepsis may be more easily traced to infection through tears in the parturient canal and other wounds, yet many cases have their origin in the respiratory organs, digestive tract including the teeth and other organs or tissues. Suppuration in any part of the body like otitis, dental or rectal fistula may give rise to sepsis. Gonorrhea or the infections may be directly the cause of sepsis or indirectly by leaving channels for the invading organisms. The most frequent organisms are the staphylococci, although ten or twelve others have been found. Sepsis affects both sexes and all ages.

In the pyemic cases, the abscesses, emboli, thrombi, degeneration of the surrounding tissues, etc., were found most frequently in the lungs then kidneys, spleen and liver. Changes found: blood dark and disintegrated; spleen large and soft; fatty degeneration of the heart; kidney large, pale with prechynmatous changes; liver large with fatty degeneration.