eChapters

Leptospirosis

Leptospirosis is an infectious disease of animals caused by spirocheate Leptospria sp. and characterized by widespread haemorrhage in visceral organs, nephritis, icterus, hepatitis and anemia (Fig.6.1).

Etiology

• Leptospira ictehaemorrhagae

• L. pomona

Pathogenesis

The organism is transmitted through direct contact with urine of infected animals or ingestion of urine contaminated feed or water. It can also be transmitted through aborted fetuses and infected uterine discharges. The organism enters through abraded skin and mucous membrane and reaches in blood and multiplies rapidly in blood producing septicemia and high rise in body temperature. Thereafter the organism localizes in the kidneys leading to acute or chronic nephritis. In kidneys, it multiplies in proximal convoluted tubules (PCT) and is excreted in urine which acts as source of infection.

Spongiform encephalopathy

Spongiform encephalopathy is an infectious disease of animals caused by prion proteins and characterized by presence of vacuoles in brain.

Etiology

• Prion proteins

• Sheep – Scrapie or Ovine spongiform encephalopathy

• Cattle - Bovine spongiform encephalopathy (Mad cow disease)

• Feline encephalopathy

Pathogenesis

Scrapie is also known as ovine spongiform encephalopathy. The principle means of transmission of disease is from infected mother to their lambs early in life; placental transmission has also been reported. The incubation period of disease is very long (2-5 year). The clinical form is restricted in adults. The prion proteins (PrP) occur normally in the central nervous system of all domestic animals and man bounded with neuronal surface. Animal susceptible to prion disease have a gene (PrP gene) which encodes for normal “Prion protein (PrP)” or “cellular prion protein (PrPc). In scrapie prion protein (PrPsc)/ scrapie associated fibril protein (SAI) is generated which are resistant for protease digestion. Accumulation of PrPsc in neural tissues appears to be the cause of the pathology in prion disease. When prion protein contaminated meat and bone meal are fed to the cattle as part of their concentration, the agent (prion) got introduced into cattle. Prion protein (PrP) on reaching brain slowly and progressively converted into and abnormal form (PrP sc) and this abnormal protein causes development of lesions including vacuolation in nerve cells.

Objective
After performing this experiment you will be able to learn:
How to  determine the caliper/GSM of paperboard.

Introduction

Thickness is calculated as the perpendicular distance between the two principle surfaces of paper or paperboard as measured under specified conditions. The GSM of paper may be defined as the thickness of a paper that is measured in a roundabout way. GSM stands for Gms per Square Metre - and is used to check the quality of the paper to be measured.

It is a very simple to perform test but tells a lot about the basic properties of the material which are very important to decide the quality of the material. Also, the quality of the material is measured with its GSM value. The heavier a paperboard is, the better the quality.

Principle

Packaging materials are chosen by estimating the GSM of the sample material. High Grammage defines the strength of the paper. In certain applications high Grammage is desired, where the paper will be subjected to load and harsh working conditions.

Objective
After performing this experiment you will be able to:
Calculate the Burst strength of the given paper and Board.
Introduction

Bursting strength is defined as the measure of resistance to rupture in various materials. A test specimen is held between two circular clamps and subjected to an increasing pressure from a rubber diaphragm. The rubber diaphragm keeps on expanding with the help of a controlled pneumatic pressure until the test specimen ruptures. The pressure required to rupture the specimen at the time of reading is known as bursting strength.

Principle

The bursting strength of paper, paper board, including linerboard and corrugated board, is a combined measure of properties of the sheet, like tensile strength and elongation. In general, bursting strength is dependent on the type, proportion, preparation and amount of fibres present in the sheet and their formation, internal sizing, and to some degree, the surface treatment. Since bursting strength is an empirical property, this test serves to define “standard grades” in commercial activity in combination with basis weight.

Objective
After performing this experiment you will be able to learn :
The Scuff Resistance of the Printed Sample.
Introduction

Scuff resistance or abrasion resistance is a desirable and sometimes critical property of printed materials. Abrasion damage can occur during shipment, storage, handling, and end use. The result is a significant decrease in product appearance and legibility of product information. A printed substrate's level of abrasion damage is influenced by numerous factors, including time, temperature, humidity, and shipping circumstances. This procedure offers a means of comparing printed materials' resistance to scuffs in a lab setting. The relative scuff resistance of printed inks, coatings, laminates, and substrates can also be assessed using this technique. This procedure can be changed to assess how a product—food, drink, powdered detergent, etc.—affects scuff resistance, which might happen when something spills or leaks while being transported. Labels, folding cartons, corrugated boxes, circulars, inserts, and other packaging materials with applied graphics on a flat substrate can all use this technique.

Objective
After performing this experiment you will be able to learn 
Determination of porosity of tin plate.

Introduction

Porosity in tinplate refers to the presence of tiny holes or pores in the tin coating on steel sheets used for making tin cans. These pores can expose the underlying steel to the contents of the can, potentially leading to corrosion and contamination of the food product. Ensuring minimal porosity is crucial for maintaining the integrity and safety of food packaging. Tinplate is produced by coating a thin layer of tin onto a steel sheet. This can be done through hot dipping or electroplating. The goal is to create a uniform and continuous tin layer that acts as a protective barrier against corrosion. During the coating process, imperfections such as pores or pinholes can form in the tin layer. These imperfections can occur due to variations in the coating thickness, impurities in the tin, or mechanical damage during handling and processing.When a tinplate can with porosity is filled with food, the contents can come into direct contact with the exposed steel through the pores.The acidic or basic nature of certain food products can accelerate the corrosion of the exposed steel, leading to the formation of rust.This corrosion can compromise the structural integrity of the can and potentially contaminate the food with rust particles or harmful by-products of the corrosion process. The primary function of the tin coating is to act as a physical barrier that prevents the food from contacting the steel. A continuous and defect-free tin layer ensures effective protection.Tin also provides cathodic protection to the steel. In the presence of an electrolyte (e.g., acidic food), tin acts as the sacrificial anode, corroding preferentially to the steel. However, this mechanism is only effective if the tin layer is relatively thick and the porosity is minimal.

Objective
After performing this experiment you will be able to learn:
How to do edible packaging of food sample.

Introduction

Edible Packaging – An edible film or coating is simply defined as a thin continuous layer of edible material formed on, placed on, or between the foods or food components. The package is an integral part of the food, which can be eaten as a part of the whole food product.

Edible packaging can be done in two types:

Edible coating: Edible coating are applied and formed directly on food (e.g. by spraying, immersion, and fluidization) via a coating solution. This will be a part of the food and must not provoke unwanted change (organoleptic, physical, and chemical).

Objective
After performing this experiment you will be able to learn:
Physical tests of packaging material.
I. Determination of Machine Direction 
Introduction
Machine-made paper has two directions and two sides:

Directions

a) Machine Direction: The direction in which the paper or board aligns with the flow of material on the paper machine.

b) Cross Direction: The direction perpendicular to the machine direction

Objective
After performing this experiment you will be able to learn:
Moisture content of packaging material.

Introduction

The moisture content of paper is a critical parameter that significantly affects its other properties, such as printing quality and absorbency. Maintaining an optimal moisture level is essential for ensuring the functionality and durability of the paper. For instance, double-faced corrugated boards tend to break or crack during bending operations if they are too dry.

Procedure

• Weigh the conditioned specimen and place it in a drying oven, maintained at a temperature of 103°C ± 2°C, to expel moisture. Continue heating until a constant weight is achieved.

• If the moisture content of the paper is to be determined "as received," the sample should not be conditioned.

Objective
After performing this experiment you will be able to learn:
pH value of packaging material.

Introduction

As mentioned earlier, these tests are performed to assess the suitability of the board for printing, corrosion protection, food packaging etc. The presence of acid in paper or paper possessing an acidic reaction is a property of specific importance. Not only may the presence of acid effect the aging properties of paper, but it also may act upon materials that come into contact with the paper. In addition, the sizing of paper, wet strength treatment, and dye and fillers retention, usually depend upon the addition of alum or other acidic materials to the beater furnish. Hence many appers are acidic to various degrees at the time of manufacture. pH is a measure of hydrogen ion present which depends both upon the amount of acidic material and upon its degree of ionization. Hence, pH does not measure the amount of acid present. Since it is the 'activity or ‘intensity’ of acid that is usually of most interest, the pH value is the more common test.

India is considered a pioneer in software development and a favourite destination for IT-enabled services. West Bengal is predominantly an agrarian State. Comprising only 2.7% of India’s geographical area, it supports nearly 8% of its population. There are 71.23 lakh farm families, of whom 96% are small and marginal farmers. The average size of land holding is only 0.77 ha. However, the State is bestowed with diverse natural resources and varied agro climatic conditions that support the cultivation of a wide range of crops.

The net cropped area is 52.05 lakh ha, comprising 68% of the geographical area and 92% of arable land. The cropping intensity is 184%. However, as the State is in the humid tropic and the Bay of Bengal is close by, it often must face natural vagaries like floods, cyclones, hailstorms, etc. Though the State has a surplus production of rice, vegetables and potatoes, a huge gap exists between the requirement and production of pulses, oilseeds, and maize. The deterioration of soil health due to imbalances in chemical fertilizers, the paucity of suitable improved seed varieties, inadequate farm mechanization, unorganized marketing structure, etc., is a major challenge to agricultural growth.

A student investigator confronted time constraints, such as course credit pressure, and resource constraints, such as physical, budgetary, and managerial constraints, in the current investigation. However, every effort and consideration made the study as objective and scientific as feasible. Despite the researcher’s best efforts, the study depends on the respondents’ opinions, which may or may not be devoid of their perceptions and biases.

As a result, it is a modest piece of labour that may be completed over a more extended period.

Suggestions for Future Research

• The findings of the present study warrant the need for further investigations in several directions. The following suggestions are made for further research in the following areas.

• The study was confined to one state; therefore, the results cannot be generalised to the whole country. Similar analyses can be taken up in other states to generalise the results.

Objective

The aim of this practical is to categorize insects based on their wing characteristics.

Introduction: Insect classification, as outlined by A.D. Imms (1957), divides Class Insecta or Hexapoda into two primary groups:

Group 1: Apterygota: These insects lack wings, and the absence of wings is considered primitive. Metamorphosis is minimal or absent. Adults typically possess one or more pairs of pregenital abdominal appendages. The mandible of adults usually articulates with the head capsule at a single point. This group comprises four orders:

1. Thysanura - Example: Silverfish

2. Diplura - Example: Japygids

3. Protura - Example: Telson tails or proturans

4. Collembola - Example: Springtails

Objective: The objective of this practical exercise is to understand the taxonomic features of the order Orthoptera and classify its suborders and families.

Observations: Order - Orthoptera (Orthos = straight, pteron = wing) Includes grasshoppers, crickets, and locusts.

Key Characteristics

1. Presence of wings, either fully developed, shortened (brachypterous), or absent (apterous).

2. Mouthparts are of the biting and chewing type (mandibulate).

3. Hind legs are typically enlarged and adapted for jumping.

4. Two pairs of wings, sometimes reduced or vestigial. The front wings, called Tegmina, are straight and thickened, while the hind wings are membranous.

5. Exhibits gradual metamorphosis, where nymphs closely resemble adults in essential features and habits.

Objective: The aim of this practical session is to explore the taxonomic features of the order Isoptera and classify its families.

Order: Isoptera (Iso = equal, ptera = wing) – Termites

Taxonomic Characteristics

1. Moderate-sized, social insects with thin skin, comprising various castes such as winged kings and queens, wingless kings and queens, workers, and soldiers.

2. Exhibits simple metamorphosis.

3. Mouthparts are of the typical biting and chewing type.

4. Wings are equal in size, long, narrow, membranous, and somewhat opaque.

5. Workers and soldiers of both sexes are wingless and sterile forms.

Objective: To explore the habits, habitats, and taxonomic features of the order Thysanoptera and the family Thripidae.

Order: Thysanoptera

Etymology: Thysano (fringed) + Ptera (wings) = Fringed-winged Insects (THRIPS)

Habitat: Terrestrial, commonly found in flowers

Habit: Phytophagous, feeding on plant material

Size: Minute to small, characterized by thin, slender elongated bodies

Taxonomic Characteristics

1. Antennae: Typically 6-10 segmented, with sensorial structures (cone like) on the 3rd or 4th segment.

2. Compound Eyes: Conspicuous, with 3-4 ommatidia in apterous forms and up to 150 in winged forms. Winged forms also exhibit 3 ocelli.

3. Mouthparts: Asymmetrical, lacking the right mandible. Adapted for lacerating, rasping, and sucking, with three stylets. The mouth cone, formed by the labrum, labium, and maxillae, extends ventrally between the fore coxae

Objective: To identify key characters of the order Neuroptera and explore the characteristics of the family Chrysopidae.

Order: Neuroptera

Etymology: Neuro (nerve) + Ptera (wings) = Wings with net-like patterns of veins

Common Members: Lacewings, Aphid Lions, Ant Lions, Alder Flies, Snakeflies

Key Features of Neuroptera

1. Neuroptera possess two pairs of similar-sized membranous wings with a complex, net-like pattern of veins.

2. They are relatively fragile insects and weak fliers.

3. Antennae are filiform, with or without a terminal club.

4. Both adults and larvae have chewing mouthparts, with larval mandibles being very strong and elongated. Some larval mouthparts are modified for piercing and sucking.

5. Larvae are compodiform and predaceous.

Objective: Explore and understand the key identical characteristics that differentiate the suborders Symphyta and Apocrita within the order Hymenoptera.

Objective: Identify and understand the distinctive features of the order Lepidoptera and its significance in agriculture through key families.

Objective: This practical aims to familiarize students with the essential traits of Diptera and explore the agriculturally significant families within this order.

Objective: To investigate and compare the taxonomic traits of Heteroptera and Homoptera, two suborders within the order Hemiptera, commonly known as true bugs.

Objective: To explore and compare the taxonomic traits of beetles and weevils through detailed examination and suitable examples.

Objective: Aims to investigate and understand the distinguishing features of butterflies and moths, focusing on their unique traits and examples.

Objective: This practical aims to understand the taxonomic traits of Megaloptera and Planipennia, focusing on their unique features and differences.

Objective: This practical aims to understand the taxonomic traits of Terebrantia and Tubilifera, focusing on their unique features and differences.

Objective: Aims to understand and identify the key differences between insects belonging to the suborders Nematocera and Brachycera.

Objective: This practical aims to understand the distinctive features of the insect order Mantophasmatodea and its major family, Mantophasmatidae.

Objective: To differentiate between locusts and grasshoppers based on their morphometric measurements and behavioral traits.

Objective: The order Dictyoptera includes insects like cockroaches and praying mantises with netted wings. Recognizing their unique taxonomic traits is essential for precise identification and classification.

Objective: To investigate and comprehend the taxonomic traits of family Mantidae, specifically cockroaches and praying mantises, through detailed examination and diagrammatic representation.

Objective: To explore and document the taxonomic characteristics of cockroaches belonging to the family Blattidae through detailed observation and analysis.

Objective: To explore and record the taxonomic features of insects in the family Pentatomidae through thorough examination and analysis of their morphology.

Objective: To thoroughly examine and record the fundamental taxonomic traits of insects belonging to the family Cicadellidae through detailed observation and analysis.

Objective: The objective of this practical exercise is to explore and document key taxonomic characteristics of Aphididae, focusing on specimens like cotton aphids (Aphis gossypii) and bean aphids (Aphis craccivora).

Objective: To study and identify key taxonomic features of whiteflies in the family Aleurodidae, which are small insects crucial as vectors of plant diseases like mosaic viruses.

Objective: To elucidate the taxonomic characteristics of Psocoptera and Mallophaga, emphasizing their distinctive morphological features, ecological roles as parasites, and significance in entomology and veterinary sciences

Objective: To differentiate and identify orthopteroid and hemipteroid groups based on their distinct taxonomic characteristics.

Objective: To study the habitat, habits, and key morphological characteristics of Dermaptera (earwigs).

Objective: To study the habitat, habits, and key morphological characteristics of Embioptera

Objective: To differentiate and document the key morphological characteristics of insects from the families Arctiidae (tiger moths) and Acrididae (grasshoppers).

Objective: To identify and understand the taxonomic status and relationships of orders within Endopterygota, focusing on their distinct larval and adult stages and current sister group hypotheses.

Objective: To explore and document the taxonomic characteristics of Strepsiptera and Mecoptera, highlighting their unique morphological features and biological adaptations.

Objective: To study and document the taxonomic characteristics of Siphonaptera and Trichoptera, emphasizing their unique morphological features and ecological adaptations.

Objective: To identify agriculturally important insect orders and understand their key morphological characteristics relevant to their impact on agriculture.