eChapters

Kirchner was the first in 1950 to think of thin layers. But it was Egon Stahl in 1958 who was responsible for bringing out standard equipment and related procedures to popularize thin layer chromatography (TLC). TLC is a modified form of column chromatography. Hence it is also called open column chromatography. The adsorbent is spread over a supporting material (glass or plastic sheets) to form a thin layer of adsorbent. As a binder, plaster of Paris or gypsum is added to the adsorbent material like silica gel (hence silica gel TLC). The adsorbent is spread over the plate as a thin layer of 0.25 or 0.5 mm. The adsorbent to water ratio is 1:2. It is initially allowed to air dry, followed by drying in an oven at 110oC for 1-2hr or overnight (activation of TLC plates) after which the plate is ready for thin layer chromatography.

The procedure used in the preparation of samples depends on the purpose of analysis and the nature of the constituents that are to be determined.

a. Plant material (Herbage)

    1.    Separate the plant material by using sharp knife.
    2.    Remove the contaminations like soil or other material by gentle brushing. Never wash the plant material with water.
    3.    Mix corresponding plant parts from more than one plant to obtain representative sample of sufficient size for analysis.
    4.    Cut the sample immediately into small pieces and mix thoroughly. 
    5.    Weigh a portion of this sample for those analyses which are to be performed on green material. 
    6.    Dry the sample in a hot air oven at 100 ± 2ºC for storage.

Digging and Filling of Pits

1.    Marking of pits and planting should always be done with the help of planting board.

2.    The guide pegs are installed at both the ends.

3.    One meter deep pits of one meter diameter should be dug.

4.    Top 30 cm soil should be kept on one side, which is used for refilling the pits as it is fertile soil.

5.    Bottom 70 cm soil should be kept on other side, which is discarded.

6.    The pits should be left exposed for a few days before actual planting.

7.    These pits should be refilled with mixture of topsoil, 2-3 baskets of silt and 2-3 baskets of well-decomposed farmyard manure.

8.    The refilled pits should be watered a few days before planting the tree. To each pit add carbofuron (25g) for control of white ants.

Review of the state of art of Drought on impact assessment, monitoring and management with special reference to agricultural production has revealed that Drought is still a complex natural disaster and difficult to forewarn in spite of advancements in atmospheric sciences and computational procedures. It is realized only after it is set in and is not known when it is likely to withdraw. A long way one has to travel to predict its occurrence, spread and its continuation to the next season over a region. The existing net work of observational set up in developing countries in Africa, Asia and in South America need to be strengthened further for effective monitoring of significant weather events at regional and micro regional level. With the rapid expansion of communication system over the past two decades, establishment of Automatic Weather Stations (AWS) at as many locations as possible even in remote regions should be taken up on priority basis and funding may be provided by the respective governments or by the International Organizations where ever necessary. Nations with limited resources may also be convinced to strengthen their weather observational net work in view of the increased occurrences of climate extremes and changing climate. Drought vulnerability regions over the globe were delineated based on sparse historical weather data which do not match with real surface conditions. Now, with the availability of weather data from more number of stations both temporally and spatially, drought prone regions over the world may be re-delineated. This would help the planners to allocate funds rationally to the affected regions. Globally every year, some regions or others may be experiencing droughts and more so in drought prone regions.

Pumpkin (Cucurbita maxima Duch.) is a well known and widely cultivated vegetable variety of the family Cucurbitaceae. The seed production can be done in summer season (February - March) and in rainy season (April - May). In Tamil Nadu, sowing during July – August is best for seed production.

Soil pores differ greatly in size, shape, tortuosity, and continuity. They are characterized generally in terms of total porosity, air-filled porosity, and pore-size distribution. The characterization of pore space is important in understanding the storage and movement of water and gases, the development of plant root systems, the flow and retention of heat, and soil strength. The observation that bulk density is considerably lower than the average particle density indicates that only part of the bulk volume is occupied by soil solids and the remainder is occupied by a lighter material, such as air and water.

Total Porosity

Total porosity (n) is the percentage of the bulk volume not occupied by solids and can be computed using following relationship:

1. Botanical Name : Baccaurea ramiflora Lour.

2. Family : Phyllanthaceae

3. Common Name : Burmese Grape

4. Name in Indian languages

Sohramdieng (Khasi) and Sohmyndong (Pnar), Khatta phal (Hindi), Moktok (Manipuri), Bhubi, Iphek (Tripura)

15.1 Computer Network

It is a group of computers and peripherals which are interconnected to share information and resources. A communication system that supports many users can be called a Network or we can say network is a communication system which interconnects many users who have something in common, either with respect to the type of data being sent or to the geographic areas that the users cover. There are three types of computer networks:

15.1.1 Local area network (LAN)

It is a small network (2 to 100 nodes) usually located within a single building or group of buildings belonging to an organization or an institute.

t TEST FOR TWO SAMPLE MEAN:

Comparison of two sample means  and assumed to have been obtained on the basis of random samples of sizes n₁ and n₂ from the same population which is assumed to be normal.

Aim

To determine the contours by grid method using dumpy level.

Materials required

Dumpy level

Leveling staff

Measuring tape

Wooden pegs/chain pins

Field book

Introduction

All biological reactions in soil are catalyzed by enzymes. Soil enzyme activities are believed to indicate the extent of specific processes in soil and in some cases, can act as indicators of soil fertility. Biological oxidation of organic compounds is generally a dehydrogenation process and there are many dehydrogenases that carry out the following reaction:

XH₂ is an organic compound and is a hydrogen donor and A is a hydrogen acceptor. These systems are integral part of the microorganisms, so dehydrogenase activity can be correlated with active population.

Principle

Measurement of dehydrogenase activity involves determination of Triphenyl formazan (TPF) produced by the reduction of Triphenyl tetrazolium chloride (TTC). TTC is a redox indicator, a yellow coloured water soluble salt which possesses the property of being easily transformed into, methanol soluble formazan (intensely coloured, water insoluble) by reduction. 

Principal Scientist and I/c Head, Division of Social Sciences and Training, IIHR, Hessaraghatta Lake Post, Bangalore – 560 089, Karnataka

Entrepreneurs have many forms of retail business ownership available to them. Each business model has its own list of pros and cons. Choosing a type of retail business to start will depend on why you want to own a business, as well as your lifestyle, family, personality, basic skills and much more. Here are a few of the main types of retail ownership and the advantages, disadvantages, and support system of each.

Veterinary anatomy is a backbone as well as basic discipline in the veterinary sciences at large. The new entrants of the first professional year of B.V.Sc. & A.H. get more exposure in gross anatomy, histo- architect models and developmental anatomy of their current curriculum in our country.
Laboratory demonstration plays a vital role module in virtual teaching and learning program of their better understanding of the subject. The visualization and memorization is the basic requirement for thorough understanding of the anatomy of the individual in medical sciences. The various method of teaching have been debated because it has own limitations. To improve the anatomical understanding the traditional way of using cadavers but with current scenario of restrictive laws which implemented by Veterinary Council of India (VCI) and other organizations viz, SPCA, PFA, CPCSEA/IAEC etc. The scarcity of specimens which are invited the other alternative way of keeping and preserving the specimens for laboratory teaching. Under the unusual circumstances, the normal conventional method of cadaver/specimen/organ preservation should be replaced by the advanced technologies for easy and interesting to learn. In the traditional curriculum method of anatomical specimens taught and learned by formalin fixed cadavers/specimens/tissues. Since, the conventional method creates health problem due to extensive use of formalin as preservative chemical for cadaver preservation. This method of preservation causes wet slippery tissues, respiratory irritation, topical allergic reactions, and students should wear gloves to protect themselves from the fixative like formaldehyde (act as a potential carcinogenic agent). However, the anatomists have been challenged for an alternative laboratory teaching aids in near future. In recent past, the alternative method has developed teaching materials by the innovative novel techniques like Plastination, corrosion cast, pneumatic air dried specimen etc.

Like many other beautiful plants, Bougainvillea has been chosen as the symbol of a host of countries, regions and municipalities. It is the National Flower of the Caribbean Nation of Granada and the United States territory of Guam. It is also the official flower of several counties in Taiwan and Malaysia. In the United States, Bougainvillea is the floral symbol of three California cities (Camarillo, Laguna Niguel and San Clemente). Bougainvillea spectabilis: Paper Flower; Common name: Bougainvillea; Scientific name: Bougainvillea spp.; Hindi: Baganvilas (Booganbel); Manipuri : Cherei; Bengali : Baganbilash; Marathi: Bougainvillea (Booganvel); Konkani: Bouganvila; Telegu: Bogam Malle (Kagithala Puvvu); Malaysia: Bunga kertas, buganvil, buginvila;  Indonesia: kembang kertas; China: Ye Zi Hua; Spain: Bouganvilla, Aka Buganvilla; Mexico and Philippines: Bugambilia; Honduras: Napoleon; Colombia, Nicaragua, El Salvador, Costa Rica and Panama: Veranera; Colombia, Cuba, Panama, Puerto Rico, Dominican Republic and Venezuela: Trinitaria; Argentina, Bolivia, Brazil, Paraguay and Uruguay: Santa Rita; Northern Peru: Papelillo.

Indian gypsy moth: Lymantria obfuscata: Lymantridae

Eggs are laid by the bulky adult female moth, which has only rudimentary wings and hence cannot fly.  Eggs are laid under the bark on the tree trunks or on fallen leaves. They feed on many shade trees and other trees also.  Feeding is gregarious and done during night. The trees are almost completely defoliated. Management involves spot application of contact insecticides at the beginning, when the larvae are small and before they disperse to the different leaves.

Electrophoresis is the migration of particles under the influence of a direct electric current. There are two requirements for this process to be carried out. First the particles to be separated should be charged or at least should accept charge. Proteins, amino acids, nucleotides etc. conform to this requirement. Second, the medium used for separating the compounds also should carry charge. The mobilities of the ions depend on the nature of the electrolyte solution, the concentration and temperature. The cations and anions move in opposite directions with the cations moving towards the anode and the anions towards the cathode.

Two German scientists Henneberg and Stohmann working at the Weende Experimental Station, Germany devised proximate principles analysis system in 1860’s for routine description of animal feedstuffs. Therefore this system is also known as Weende system of analysis. Proximate analysis is a system of expressing the nutrient composition of a feed. The principle of analysis is to separate the nutrient present in the feedstuffs into various fractions, as proximate principles, which are six i.e. moisture, ash, crude protein, ether extract, crude fibre and nitrogen free extract.

Water (Moisture)

The moisture is determined as the loss in weight which results from drying a known weight of feed to constant weight at 100°C. Therefore, dry matter is estimated as a part of substance that does not evaporate at 100°C. The major difference in nutritional value on as fed basis is traceable to moisture content and dry matter. Calculation of relative cost of nutritional value involves consideration of moisture content.

Water is the most important and abundantly required nutrient for poultry. A continuous supply of clean, fresh and wholesome potable water is essential for poultry. Poultry rearing is becoming more and more intensive with which the chances of the infectious diseases being sustained in the different flocks also increase. Consequently, the need for effective disease control measures to be adopted also gains further importance.

Most often, poultry farmers get alarmed only when the mortality level or death rate in a farm is high. However, even the existence of disease at a sub-clinical level may hinder the performance of the birds, in terms of body weight or egg number; such economic losses, sometimes relatively less and unnoticed, may mean the difference between success or failure in the poultry business. Treatment of a sick flock after the onset of any disease becomes costlier and more frequently impracticable. The recovered birds may not regain their production to original levels and may also continue as source of infection to other healthy birds. Hence, the adage ‘prevention is better than cure’ applies more to poultry industry than any other field.

Plant diseases are classified on the basis of type of pathogenic or non- pathogenic causes of the disease. The classification is based on the plant pathogenic organisms as follows.

PARASITES

They include both biotic and mesobiotic agents. The diseases are incited by parasites under a set of suitable environment. Association of definite pathogen is essential with each disease.

i. Biotic agents: They are also called as animate causes. They are living organisms. Biotic agents include:

Remote sensing has proved its credibility beyond doubt in natural resources survey and environmental monitoring owing to its synoptivity, multispectral photographic capability and repetitive coverage. While its synoptivity gives unbiased information on the regional panorama of the earth surface, its multispectral possibility aids precise interpretation of various objects, as different terrestrial objects exhibit various spectral responses in different bands of the electromagnetic spectrum. Amongst various terrestrial objects, water has a characteristic spectral response of its own, i.e. it permits the blue / red part of EMR (electromagnetic radiation, 0.4-0.8 µm) to penetrate inside. On the contrary, it totally absorbs the infrared part of EMR (0.8-1.5 µm). As such blue/red part of EMR penetrates the water bodies, the impurities and suspended sediments are seen very clearly in various shades of gray as and when the water bodies are shallow. Many workers, therefore, have used blue / red band of the satellite data in such water-quality studies^l-3. Hardy⁴ has observed that the infrared light in the spectral regions of 0.6-1.4 µm has the potential to map the turbidity in the ocean water, whereas Kritakos et al ⁵ have used the rationed data of visible and near infrared bands (0.4-1.1 µm) and obtained better results for water quality monitoring. Keeping such facts in mind, the blue/red band (band 2) of the IRS 1A satellite data was used to configurate the bathymetry along Madras coast in Bay of Bengal (Figure 1 a).

In the present study, the IRS lA band 2 data (0.52-0.59 µm) of March 1991 was used and subjected to edge enhancement studies for the coastal zone of Madras (Figure 1 a). Such edge enhancement normally sharpens the edges of two contrasting objects or sharpens the edges of objects of contrasting relief. In such edge enhanced data, few