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The annual variations of phytoplankton pigments were studied from January to December, 1971 at four stations in the backwater area (Porto Novo, India). At these stations, chlorophyll a varied from 2.91–65.56 μg/1; chlorophyll b from 0–1.90 μg/l; chlorophyll c from 0–38.60 μg/1; plant carotenoids from 0.30–22.34 MSPU/m 3 and phaeopigments from 0–31.51 μg/l. The main (or primary) maximum of chlorophyll a appeared during June at Stations 3–5 and at Station 6, it was during May. Stations 3 and 4 had secondary chlorphyll a maxima during September and at Stations 5 and 6 during August. In general, all the stations showed an increasing trend of chlorphyll a values before the main peak. The chlorophyll a maximum was mainly due to the presence of phytoplankton species belonging to the genera such as Noctiluca, Coscinodiscus, Thalassiothrix, Biddulphia, Hemidiscus, Melosira and Rhizosolenia . Amongst all the backwater stations, Station 5 had the highest chlorophyll a (65.56 μg/1) and the lowest chlorophyll a was recorded at Station 3. Chlorophyll a concentration was normally affected by rainfall.

The annual variations of phytoplankton pigments were studied from January to December, 1971, at two stations of the local mangrove (Pichavaram) environment. At these two stations, chlorophyll a varied from 2.90 to 35.06; chlorophyll b from 0 to 10.02 and chlorophyll c from 0 to 18.12 μg/l. Plant carotenoids varied from 1.56 to 13.83 MSPU/m3 and phaeopigments from 0 to 12.28 μg/l. The main (primary) peak of chlorophyll a was recorded during March at Station 1, and during June at Station 2. Secondary maxima occurred during June and August at Station 1, and during September at Station 2. During the period studied chlorophyll a was the dominant pigment at both the stations, followed by chlorophyll c and chlorophyll b in that order. The increase in the concentration of pigments was mainly due to the presence of phytoplankton species belonging to the genera such as Coscinodiscus, Rhizosolenia, Thalassiothrix, Melosira, Chaetoceros and Biddulphia. During October, phytoplankton was less and the pigment concentration was also low.

Zusammenfassung Kerntechnologisches messgerat der sedimentanreicherung—ein vergleich der ubergangs- und streuungs-arbeitsweisen Dieser Artikel gibt einen Vergleich zwischen den “Ubergangs”- und “Streuungs”-Verwendungsarten eines Am-241 Messgerats fur die Anreicherung von Sediment in Suspension. Es wird sowohl aus theoretischen Erwagungen und aus Versuchen gezeigt, dass zwischen den beiden Arbeitsweisen keine wesentlichen Unterschiede bestehen konnen. Die beschrankte praktische Nutzlichkeit des Messgerats in hydrologischen Forschungs-arbeiten, wo die Sedimentanreicherungen in der Grossenordnung von 0 bis 3000 ppm liegen, wurde ebenfalls erklart.

1. A rare case of a combined intra-nasal and extra-nasal glioma is being presented in this report. 2. The origin of nasal gliomas is not known. The various conjectures about the origin is being discussed. 3. The Pathology diagnosis is mostly based on. 4. Surgical excision is the treatment of choice.

This report describes how radiotracers were employed to study the flow path of seepage in dams. Bromide-82 as potassium bromide was used as tracer. Scintillation counters and G.M. tubes, attached to long waterproof cables were used for detection of the radiotracer in the boreholes in the structure of the dam, and in the water adjacent to the dam. Some of the major points of entry of seepage and the flow path of seepage across the coffer dam were established. The utility of iodine-131 in this type of experiment was also determined.

A brief survey of the many existing computational and experimental methods in estimating seepage losses from unlined canals is given. A new method is suggested in this paper in which the filtration velocity of seepage is measured using radioisotopes. The seepage rate is then computed from the knowledge of the phreatic curve and Numerov's theoretical formula for laterally spreading seepages from unlined canals. A practical application of the procedure to estimate seepage losses from Ganga Canal near Roorkee is also described.

A survey was conducted on 15th November, 1970, in mangrove forests and backwater regions of a section of the Vellar-Coleroon estuarine complex; a total of 19 stations were occupied. Detailed investigations on nutrients, pigments, and plankton were carried out. The following ranges in values were recorded: salinity, 10.40 to 30.50‰; pH, 7.50 to 8.30; temperature, 29.50° to 30.50°C; total phosphorus, 0.72 to 3.34 μg at/l; inorganic phosphate, 0.19 to 1.59 μg at/l; ammonia, 0.34 to 0.36 μg at/l; nitrite, 0.11 to 0.25 μg at/l; nitrate, 2.85 to 6.94 μg at/l; silicate, 18.49 to 134.92 μg at/l. Dissolved oxygen content ranged from a minimum of 3.69 ml to a maximum of 5.44 ml/l. Chlorophyll a ranged from an undetectable amount to 1.01 mg/m3, chlorophyll b from 0.02 to 0.85 mg/m3, chlorophyll c from 0 to 0.41 mg/m3 and carotenoids from 0 to 0.74 MSPU/m3. The plankton displacement volume ranged from a negligible amount to 3.60 cm3/m3; seston varied between 0.29 and 0.91 g/l. Phytoplankton was abundant at 3 stations; at other stations zooplankton was abundant. Coscinodiscus, Asterionella and Ditylum were the dominant forms among the phytoplankton; Oithona, Acrocaanus, Euterpina, Centropages, Corycaeus, Lucifer and Oikocreura were dominant among the zooplankton. Phytoplankton and zooplankton populations, as percentage of the total plankton, varied between 3.70 and 89.00% and between 11 and 96.30%, respectively. Average gross production values in the mangrove and back-water stations were 7.56 and 3.33 g C/m3/day, and the net production values 6.29 and 2.67 g C/m3/day, respectively.

This paper attempts to make a systematic comparison of all important criteria for the selection of either scandium-46 or iridium-192 as the radioisotopic glass tracer for bed-load transport studies in rivers and estuaries. This study has been restricted to only these two tracers as they are found to be the only strong contenders for long-range quantitative studies. The discussion leads the authors to the conclusion that except for the transport problem, scandium-46 is preferable to iridium-192 in all other respects.

The study was carried out in the neritic and estuarine waters of Porto Novo, Coromandel Coast, Bay of Bengal, India during the period January, 1960 to December, 1967. The average displacement volume of plankton usually varied between 2 and 4 c2/m2. During summer, with a season of high plankton productivity, the average plankton displacement volume rose to 8 c2/m3. Generally speaking, the average zooplankton density (standing crop) was usually between 80,000 and 100,000 organisms/m3, of which copepods alone comprised usually between 70,000 and 90,000 organisms/m3. The average copepod density per sample varied from 30,000 to 50,000 organisms/m3. However, in the summer months, the copepod density was usually not less than 100,000 organisms/m3; in some years this was even higher (from 125,000 to 170,000 organisms/m3). Copepods comprised between 80 and 95% of the zooplankton population. The maximum non-copepod population in the zooplankton seldom reached 30%, was ofter below 25%, and usually less than 20%. During the period March to October (in some years as early as February, and in some years up to November), either an increasing or a steady trend of plankton production was evident. It would appear that salinity and rainfall determine the occurrence and distribution of plankton in Porto Novo.

The seasonal variations of marine (collected at the ten fathom line-Station A) and estuarine (collected at the Mouth of the Vellar estuary-Station I) plankton of Porto Novo (India) are described, covering the period 1960–63. The biological, temporal and numerical variations of phytoplankton and zooplankton are described for the two stations. The succession of species was more or less similar at both stations, but certain forms like colonial Radiolaria, Scyphomedusae, Anthozoa, trochophore of Sipunculids, Stomatopod larvae and Protochordate larvae were relatively more confined to Station A, and crustacean larvae other than Stomatopods Actinotrocha larva, fish eggs and larvae were relatively more confined to Station I.

In this paper an attempt has been made to develop a simple theory for the application of radiotracer techniques to estimate the quantum of bed material transported in rivers, estuaries, etc. The emphasis is mainly on the physical concepts involved. Certain assumptyions made in the theory are later verified experimentally.

A new technique is reported on the rapid screening of fumigants for their reactivity or non-reactivity with chemical constituents of foods particularly those which can be studied by paper chromatography. In the present study, extremely low quantities of amino acids spotted on paper and exposed to the volatile chemicals indicated high reactivity of methyl bromide, methyl iodide, ethyl bromide, vapona and β-propriolactone with methionine, after development of the chromatogram. This chromatographic technique offers good scope for picking out the non-reactive fumigants with ease, rapidity and reliability. It can be used as a tool for predicting the reactivity of the chemical with the constituents of the food, and the residues which a fumigant would have in fumigated foodstuffs during exposure.

Studies were made to examine the applicability of a common leaf product constant (K-constant × length × width), for estimating the area of single leaf and it was found that the same constant was applicable for the 3 sorghum genotypes (Sorghum bicolor L Moench) studied (K=0.71). Adaptability of the common leaf product constant for individual leaves according to its position in the plant was also tested by regression analysis, and the same constant was found to be applicable in most cases. Because complete measurement of all leaves of a plant in field trials is time-consuming and involves prohibitive labor input, the most representative leaf was identified through correlation studies to use it in working out the leaf area index. The largest leaf was found to be the most representative. This representative leaf differed with genotype, depending upon total leaf number. An appropriate factor to work out leaf area of the whole plant from a single leaf was determined. This leaf area factor was found to vary from 4.106 to 5.873 among the sorghum genotypes

CEREAL yields have been shown to depend more on assimilation in the ears and flag leaves than on translocation into the grain of compounds manufactured or stored in other green parts of the plant1. Quantitative estimates of the relative contributions from the ears, the flag leaves or other green parts have been made by shading and defoliation methods2–6, by enclosing ears in a transparent chamber supplied with 14CO2 (ref. 7), or by following changes in the carbon dioxide content of air-streams entering and leaving such a chamber8. Such methods have been criticized for various reasons9,10. Buttrose and May9 claimed that their technique with regulated floret numbers is free of many of these disadvantages, but Thorne8 has shown that one of the assumptions on which the method is based is not valid and Lupton11 has demonstrated that different results can be obtained if different numbers of florets are left on the ear. Obviously, this method of measuring net assimilation of cereal ears is also open to criticism.

STORED food-grains suffer from considerable losses due to insect infestations in the tropical and subtropical regions of the world1. During post-harvest storage, cross-infestation by insect pests and the multiplication of pests as a result of field-infestation occur in stored grains even within a storage period of a few months in warehouses2–3. Fumigation with noxious gases such as methyl bromide, carbon disulphide, carbon tetrachloride, hydrocyanic acid, ethylene oxide and others, although of use in the control of most infestations, is not easy for the producer or the warehouse-man to apply2. Parkin1 observed that application of such measures unfortunately lags behind the advance of knowledge in all but the most highly developed countries, and even in those is not always so widespread or up-to-date as it could be. A new approach has therefore been made to replace the fumigation treatment with a relatively simpler prophylactic spray treatment of the grain under pre-harvest condition, using a chemical of low toxicity for mammals, for the control of pest infestation during post-harvest storage.