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The development of the upper respiratory system composed of nasal cavities, naso pharynx and larynx is directly related to the development of the face. The nasal cavities are derived from ectoderm while nasopharynx and larynx are endodermal in origin. The lower respiratory system (trachea and lungs) is a derivative of the embryonic pharynx.

The epithelial lining of the lower respiratory system is endodermal in origin, while the surrounding connective tissue and cartilage are mesodermal in origin. The endoderm and underlying mesoderm from the floor of foregut i.e caudal part of pharynx grow caudally in midline and form the laryngo-tracheal groove at about the level of the branchial arches IV -VI from which the larynx and trachea arise. The laryngotracheal tube consists of an inner endodermal lining and an outer layer of splanchnic mesoderm. It grows into underlying mesenchyme. Ingrowths from the sides of the groove at about the level of the branchial arches IV - VI form a pair of ridges that grow towards each other and fuse forming a septum changing the groove into a tube with a blind end caudally. The rostral end opens into the floor of the pharynx. The blind caudal end expands in a bilobed manner into mesenchyme forming bronchial buds the primordia of right and left lungs while the groove is closing.

larynx : A pair of elevations, aryteniod swellings appears on the floor of the pharynx along midline at the level of branchial arch IV. The hypobranchial eminence is just infront of the arytenoid swellings. The depression between the hypobranchial eminence and the arytenoid swellings becomes the lumen of the larynx. The caudal part of the hypobranchial eminence forms the epiglottis. The arytenoid swellings and adjacent branchial arch mesenchyme form the other laryngeal cartilages and musculature. The thyroid cartilage arises from branchial arches III and IV. The other cartilages are derived from mesenchyme of branchial arches IV, V & VI. The intrinsic musculature of larynx is derived mostly from the branchial arch V and VI. With the exeption of the epiglottic cartilage the cartilages and muscles of the larynx are formed by the end of embryonic period.

The kidneys develop from the nephrotome (intermediate mesoderm). The series of nephrotomes forms urino-genital ridge which splits up into an lateral nephric and a medial genital ridge, which project into the coelom from the dorsal wall. This is the short segment of mesoderm that connects somite with lateral mesoderm. Three sets of kidneys are formed during embryologic development in vertebrates viz., pronephros, mesonephros, and metanephros. First two sets are temporary structures and third set becomes the kidneys found in the adult.

MENDEL’S RULES OF GENETICS DO NOT ALWAYS WORK

Mendel’s rules:

Segregation of alleles

Independent assortment of genes for different characters

Hold for characters:

Which have dominant & recessive traits

Determined by single genes

Genes are on separate chromosomes

Different types of chromosomes, or

Different homologues of same type of chromosome

These conditions are not always met, so there are many complications

Chromosomes are giant molecules of DNA

Found in nucleus: never leave except in cell division

Carry hereditary units, genes

Two homologous copies in diplod cells

Unwind when replicating or making RNA

Wind up (condense) in cell division

Attach to spindle and separate in meiosis & mitosis

Crossing over in prophase of 1st meiotic division

Chromosomes are equally distributed in mitosis, meiosis

Gametes have half the number of chromosomes as body cells

Sister chromatids are observed to split apart longitudinally in anaphase

UNTIL THE 1940S BIOLOGISTS ARGUED ABOUT WHETHER DNA OR PROTEIN WAS THE MOLECULE OF HEREDITY

Nuclei observed to divide when cells reproduced themselves

Large amounts of both DNA & protein in the nucleus

Many though protein was most likely molecule of heredity

Proteins made of 20 different amino acids- could have more variety than DNA (made of only 4 different bases)

Restriction enzymes cut only at specific sequences of 4 to 8 bases

A long restriction site is rare. Cutting rare sites will produce a few large pieces of DNA.

Restriction enzymes with long sites → small number of large fragments

Restriction enzymes with short sites → large number of small fragments

Cervical vertebrae

The skeleton of neck (Fig 2-1) is formed by the cervical vertebrae. These are seven in number. Of these, the first and second cervical vertebrae are highly modified and deviate greatly from the general architectural plan of the vertebrae. The third, fourth and fifth cervical vertebrae are similar and confirm the general plan of the vertebrae. The sixth and seventh vertebrae have some special characteristics but do not deviate much from the general plan. The general plan of vertebrae and the vertebral column has been described in the chapter on skeletal system under Part I on systemic anatomy. Hence, only regional specific characters of the cervical vertebrae are described hereunder.

First cervical vertebra (Atlas)

The first cervical vertebra (Figure 2-2 A) is called the atlas vertebra because in man it supports the globe of the head. This is an atypical vertebra and it deviates greatly from the general plan of vertebrae. The body and the spinous process are absent. The arch forms a bony ring from which two large curved plates, the wings project laterally. The ring encloses the vertebral foramen. It forms a part of the vertebral canal through which passes the spinal cord.

Things required for cell culture

1. Lab – having negative pressure (HEPA filter)

2. Safety cabinet (Hood/laminar flow)

a) Biosafety level 1 (BSL-1) – Basic level of protection. Agents handled under this cabinet are NOT infectious.

b) BSL-2 – Appropriate for moderate risk agents. Most of the non infectious cell cultures are done under this facility.

Cell counting is the fundamental techniques in various fields of biology, medicine and biotechnology.

Importance of cell counting

1. Research: Cell counting is a critical component of biological and medical research. It helps scientists understand the behavior of cells in various contexts, such as studying cell proliferation, differentiation, and response to stimuli.

2. Disease diagnosis: Monitoring various medical conditions, including infections, autoimmune diseases, cancer and blood disorders. Complete blood counts (CBCs) are routinely used to assess the levels of different blood cell types and assess disease conditions.

3. Stem Cell Research: Cell counting plays a significant role in stem cell research, where precise quantification of stem cells is necessary for various applications, including regenerative medicine and tissue engineering.

4. Cell Culture: Cell counting is integral part to determine seeding density. Seeding of cells to available surface area for growth is important consideration for successful culture.

5. Cell-Based Assay: The cell-based assays are used for drug screening, toxicity testing, and evaluating the efficacy of new compounds. Accurate cell counts are essential to ensure the reliability of assay results.

Introduction

Peripheral blood mononuclear cells (PBMCs) consist of chiefly of lymphocytes and monocytes. Purified PBMCs are used in vitro to evaluate a variety of functions of lymphocytes viz; a) proliferation to mitogenic (PHA, Con-A) stimulation, b) monitoring of prior sensitization in antigen recall assays by scoring lymphocyte proliferation, c) immunophenotyping for surface markers as well as intracellular molecules in monocytes and lymphocytes etc. Activation of monocytes/macrophages by small molecules, cytokines and pathogen components can also be monitored. PBMCs can also be used for a variety of structural and functional studies for addressing issues in human immunology such as scoring for apoptosis and production of cytokines as well as other mediators in vitro.

Background information

Blood is a liquid mixture comprised of plasma, cells and proteins. The liquid portion, plasma, makes up half of the blood volume, and cells the other half. Isolation of lymphocytes is a common procedure in immunology and cell biology that involves separating and collecting lymphocytes.

Principle

The quantification of infectious virus particles is commonly achieved through the utilisation of the Median Tissue Culture Infectious Dose (TCID50) assay. The assay functions through the introduction of a serial dilution of the virus sample into cells in a 96 well plate format. The chosen cell type is specifically intended to exhibit a cytopathic effect (CPE), which refers to observable changes in morphology or cell death resulting from viral infection. Following a period of incubation, the cells are examined for cytopathic effects or cell death, and each well is categorised as either infected or uninfected. The concentration at which 50% of the wells exhibit a cytopathic effect (CPE) is employed to determine the 50% tissue culture infectious dose (TCID50 ) of the viral sample. The end point is the dose or dilution that infects or kills or shows CPE of the cells. The calculation can be performed using various mathematical techniques, such as the Spearman-Karber method or the Reed Muench method. The virus titer is quantified as the number of tissue culture infectious dose 50 (TCID50 ) per millilitre (ml). The non-cytopathic virus can be quantified by employing the fluorescent antibody test, immune-peroxidase assay, or other appropriate methodologies.

Climate change is now a global phenomenon and its impact on livelihood health and wellbeing, and overall quality of life is not deniable. No country is free from the overall impacts of climate change, but poor people of developing countries have been disproportionately affected by the adverse effects. Vulnerability in the context of climate change is a function of sensitivity, exposure and adaptive capacities. Odisha is the 9^th largest state by area and the 11th largest state by population in India. The state has an area of 155,707 km², which is 4.87 per cent of the total area of India, and a coastline of 480 km. In the eastern part of the state lies the coastal plain. It extends from the Subarnarekha river in the north to the Rushikulya river in the south. The State is broadly divided into four geographical regions, i.e. Northern Plateau, Central River Basins, Eastern Hills and Coastal Plains. The climate of the state is characterized by hot summer and cold winter in the interior parts. The state has historically been highly prone to climate change and multiple hazards – mainly cyclones, droughts and ?oods. Natural disasters devastate millions of lives and livelihoods in Odisha each year. More children and women suffer from the effects of natural disasters and this is predicted to worsen as storms ?oods and droughts become more severe and frequent because of climate change.

Principle

Cell viability refers to the quantity of healthy cells in a sample, while cell proliferation is a crucial indicator for comprehending the mechanisms and pathways involved in the survival of cells or death following exposure to toxic substances. The methods used to assess viability are typically the same as those used to detect cell proliferation. Cell cytotoxicity and proliferation assays are commonly employed in drug evaluations to determine if the test compounds impact cell proliferation or exhibit direct cytotoxic effects. Cell viability can be determined by calculating the ratio of total live cells to the total number of cells (live and dead). Staining also helps to observe the general cell structure. Cell proliferation assay by MTT. Metabolically active cells reduce the yellow tetrazolium MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) through dehydrogenase enzymes to produce NADH and NADPH. The purple formazan produced inside the cell can be dissolved and measured using spectrophotometry. The MTT Cell Proliferation Assay quantifies cell proliferation rate and detects decreases in cell viability caused by metabolic events leading to apoptosis or necrosis. The MTT Reagent produces minimal absorbance values when no cells are present.

Spinal nerves

The thoracic spinal nerves are thirteen pairs in ox. These are named and numbered according to the vertebra caudal to which they emerge from the vertebral canal. They emerge from the vertebral canal through the respective lateral vertebral (intervertebral) foramina. Each nerve, after its emergence, divides into dorsal and ventral branches. Each dorsal branch passes up dorsally between the transverse processes of the vertebrae and divides in to medial and lateral branches. The medial branch passes upward and supplies the dorsal muscles of the back. The lateral branch passes laterally on the deep surface of the longissimus dorsi muscle. At the lateral border of this muscle it passes between this and longissimus costarum muscles and becomes a cutaneous nerve which divides into ascending and descending branches supplying the muscles and the skin of this region.. Before its division, the lateral branch supplies muscular branches to the longissimus dorsi and longissimus costarum muscles.

The ventral branches continue ventrally as intercostal nerves. The first and second thoracic nerves, before their continuation as intercostal nerves, give out a branch to the brachial plexus. At a short distance from the spinal nerve, the ventral branch of each of these nerves is connected to sympathetic trunk by a ramus communicans containing preganglionic and postganglionic sympathetic fibres. The intercostal nerves run down ventrally through the intercostal spaces, lying between the external and internal intercostal muscles close to the caudal border of the respective rib and in company with the intercostal vessels. Along this course they supply these muscles. After a variable distance, the intercostal nerves and vessels traverse through the internal intercostal muscles and become subpleural in position. The second to eighth nerves end in the transversus thoracis muscle. The rests behind these end in the rectus abdominis and other abdominal muscles and the skin in this region.

Introduction

Climate change is one of the important areas of concern for world to ensure food and nutrition security to the growing population. The impacts of climate change are global but development countries like India are highly vulnerable as large population depends upon agriculture and allied service. As per the latest report, the global average temperature rises is 0.99⁰C (NASA, 2016) since pre-industrial time (1850). The year 2016 ranks as the warmest year, 16 of the 17 warmest years in the 136 years record all have occurred since 2001. The predicted temperature rise for India is in the range 0.5-1.2⁰C by 2020, 0.88-3.16⁰C by 2050 and 1.56-5.44⁰C by the year 2080. Studies in India showed significant negative impacts of climate change, predicted to reduce yields by 4.5 to 9.0%, depending on the magnitude and distribution of warming. Agriculture sector is contributing about 17.4% of India’s GDP, a 4.5-9.0% negative impact on production implies a cost of climate change to be roughly up to 1.5% GDP per year. Therefore, Govt. of India has accorded high priority on research and development to cope with the climate change in general and agriculture and allied sector. The Prime Ministers National Action Plan on Climate Change has Identified Agriculture and allied sector as one of the 8 national Missions. Agriculture and the future of global food security figure very importantly in climate change negotiations. As stated in Article II of the United Nations Framework Convention on Climate Change (UNFCCC), the goal is to ensure stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent “dangerous anthropogenic interference with the climate system”. With this background to meet the challenges of sustaining domestic food production in the face of changing climate and to generate information on adaptation and mitigation in agriculture to contribute to global for a like UNFCCC, the Indian Council of Agricultural Research (ICAR) launched a flagship network project National Initiative on Climate Resilient Agriculture (NICRA) during XI plan in February 2011, and during XII Plan it is referred as National Innovations in Climate Resilient Agriculture (NICRA).

Introduction

Climate change and pollution are the two major concerns that retard growth in animal sector particularly in a developing country like India. Pollution is directly contributed by human beings, while the former is also an after effect of continuous abuse of nature and natural resources. Hence these two areas are to be looked into seriously for country’s growth in general and animal production in particular.

Stress Effect

Stress is nothing but inability of an animal to cope with its environment, a phenomenon that is often ends up with a failure to achieve the full genetic potential. Stress may be from any origin and can even be a disease itself. There exists a variety of endocrine regulatory points of stress which limits the efficiency of production and reproduction. A simple transport produces an immediate constant increase in arginine, vasopressin and corticotrophinreleasing hormone secretion in animals. However, adenocorticotrophic hormone reaches a maximum in the first hour, while cortisol is highest during the second hour. Contrastingly, the hypothalamo–pituitary–adrenal response is delayed occurring only after glucose decreases below a threshold in an insulin treated animal. Negative feedback effects appear to operate mainly at the pituitary level during transport but at the hypothalamus during hypoglycaemia.

Livestock farming is an important activity to a large population of small and marginal farmers as well as landless agricultural labourers of Tamil Nadu. It also provides employment opportunities for most of the unemployed and underemployed in the rural areas. Tamil Nadu is bounded by the Eastern Ghats on the north, by the Nilgiris, the Anamalai Hills and Kerala on the west, by the Bay of Bengal in the east, and by the Indian Ocean on the south. Tamil Nadu is the eleventh largest state in India by area. The land area has been classified into seven agro-climatic zones based on soil characteristics, rainfall distribution, irrigation pattern, cropping pattern and other ecological and social characteristics. Tamil Nadu endowed with 13.97 per cent of recognised breeds of the domestic ruminants (cattle, buffalo, sheep and goats) with 22.55 millions of population (19^thLivestock Census-2012).

Introduction

Climate change represents a threat not only to the existence of individual species, but also to the genetic diversity hidden within them. The finding promises to complicate assessments of how climate change will affect biodiversity, as well as conservationists’ task in preserving it.

Climate change comes as an additional factor affecting a livestock sector that is already highly dynamic and facing many challenges. Important objectives of AnGR management include ensuring that AnGR are effectively deployed to meet these challenges (i.e. are well matched to the production environments in which they are kept) and that the genetic diversity needed to adapt production systems to future changes is maintained. Climate change is likely to create a number of problems in many areas of animal husbandry (housing, feeding, health care, etc.) and threaten the sustainability of many livestock production systems and their associated AnGR. At the same time, many of the specific challenges associated with climate change (high temperatures, disruptions to feed supplies, disease outbreaks, etc,) as well as the general unpredictability it brings to the future of the livestock sector, highlight the importance of retaining diverse genetic options for the future. The upper critical temperature of dairy cattle is lower than other livestock species (Wathes et al.,1983).

Introduction
A significant aspect of an animal’s existence is their adaptability to changing circumstances and their willingness to adapt their behaviour. An animal becomes more intelligent the more it learns. Associative and non-associative learning are the two main categories into which learning can be divided. Whereas associative learning involves classical conditioning, non-associative learning involves sensitization and habituation. When a stimulus
occurs frequently, an individual develops a gradual familiarity with it. This is known as habituation. Sensitization, on the other hand, is the increased response to the same stimulus that may or may not be related to other variables. In order to get the desired response, training is required for the behavioural responses to two independent stimuli that are kept associated during the conditioning process. In general, non-associative learning stems from an animal’s perception of its environment or circumstances, whereas conditioning is based on training-based learning.

The urinary organs include the kidneys, ureters, bladder and urethra (Fig. 4-5 A).

Kidneys

The kidneys are two compound tubular glands situated retroperitoneally in the sublumbar region. They are elongated, the right kidney being elliptical in outline and the left one slightly oval. They are red brown in colour. The weight of each kidney varies from 500 to 700 gm, the left kidney being about 25 gm heavier than the right kidney. The outer surface of the bovine kidneys is marked by polygonal lobes which are about twenty in number and are separated from each other by deep grooves (fissures). The grooves are filled in by fat. Both the kidneys are embedded in a large amount of perirenal fat termed as adipose capsule.