Kashinath Bhattacharya

Deteriorative changes of maize, groundnut and soybean seeds by fungi in storage

This paper deals with investigations on fungal infection, moisture content, germinability and deterioration of three seeds, viz., maize (starchy), groundnut (oily) and soybean (proteinaceous) in storage at the locality of Santiniketan, West Bengal, India, under natural condition for 1 year. The airspora of storage environment was trapped using culture plate method. Different species of Aspergillus (A. candidus, A. flavus, A. niger, A. terreus, and A. ruber) were dominant followed by Rhizopus, Penicillium, Curvularia, Fusarium, Alternaria, etc. Seed moisture was maximum in the rainy season followed by a gradual decrease during longer storage. A gradual decrease in field fungi with simultaneous increase in storage fungi accompanied by a reduction in germinability occurred in all seeds as storage proceeded. A gradual loss of carbohydrate (both soluble and insoluble) content in all the seeds were recorded. A loss of protein content was recorded followed by a small increase. Oil content decreased in prolonged storage with simultaneous increase in fatty acid.

Indoor and outdoor aeromycological survey in Burdwan, West Bengal, India

A comparative survey of airborne fungal spores in fiveindoor and five outdoor environments in Burdwan, WestBengal, India, was carried out for a period of twoyears using rotorod samplers and sedimentation plates(culture plate). A total of 29 spore types wereidentified, of which three were Phycomycetous (Mucor, Rhizopus, Syncephalastrum), one Ascomycetous(Chaetomium), one Basidiomycetous (Ganoderma) and the remainder were Fungi Imperfecti. The results revealed lowest count during summer andmaximum during the rainy season. Aspergilluswas quite abundant in all the environments surveyed. The predominance of Aspergillus, Curvularia,Alternaria, Cladosporium, Drechslera, Fusarium in allthe surveyed environments has been attributed to theirability to grow in various substrata. The occurrenceof Cladosporium in the winter months suggestthat it is sensitive to high temperature. Allspore types were common in both environmentsexcept Bispora, Cercospora, Papularia, Spegazzinia, Trichothecium in the outdoor sites. Acorrelation has been made between the volumetriccomposition of airspora and the incidence of seasonalmold allergy.

Aerobiology, allergenicity and biochemistry of three pollen types in Berhampore town of West Bengal, India

An aerobiological survey was performed in Berhampore town of West Bengal, India, to know the frequency of three common airborne pollen, namely Acacia auriculiformis, Eucalyptus citriodora and Madhuca indica using an ASTIR one day volumetric sampler. Acacia pollen showed its peak concentration in September, followed by Madhuca in April, while Eucalyptus showed its two peaks between September–October and January–April. Meteorological factors like temperature, RH, rainfall played an important role in release and dispersal of pollen. Skin prick tests with the antigenic extracts of the three pollen types, showed their allergenic potentialities. The highest markedly positive reactions were exhibited by Eucalyptus (34.04%), followed by Madhuca (22.93%) and Acacia (21.87%). 30–60% (NH4)2 SO4 cut fraction (Fraction II) of each pollen type showed maximum positivity in skin prick test. Biochemical analysis showed that Acacia pollen was richer in protein and carbohydrate, than the other two types. The total protein component of the above types were studied by SDS-PAGE showing different protein bands with a range of molecular weight 29–110 KD. In isolated fraction II (allergenically most potent) of Eucalyptus and Madhuca different protein band of 43–200 KD were obtained, while a single protein band of 57 KD was obtained for Acacia. The IgE specific allergenic reactivity was confirmed by Dot-blotting technique.

Measuring Indoor Fungal Contaminants in Rural West Bengal, India, with Reference to Allergy Symptoms

An airborne fungal spore survey in five indoor environ ments in Santiniketan, West Bengal, India was carried out for a period of 2 years using the Astir 1-day personal volumetric sampler as well as a Rotorod sampler and sedimentation plates. A total of 24 fungal spore genera in addition to Aspergilli were recorded of which three were Phycomycetes (Cunninghamella, Rhizopus, Syncepha lastrum), two were Ascomycetes (Chaetomium, Pleospo ra), one was Basidiomycete (Ganoderma ) and the re mainder were fungi imperfecti. Aspergillus contributed most to the total aerospora in the environment, followed by Curvularia and Cladosporium. The occurrence of aerospora exhibited a distinct seasonal periodicity in their annual distribution, perhaps due to differences in meteorological conditions. Concentrations were lowest in summer and highest during monsoon and postmon soon periods. High concentration of spores in winter was due to a large number of saprophytic forms, of which Cladosporium was the major component. The predomi nance of Aspergillus, Curvularia, Cladosporium, Alter naria in all the indoor environments contributed to their ability to grow in various substrata. Moreover, indoor aeroflora might have been diluted by the outside aeroflo ra entering through different inlets. The clinical investi gation clearly demonstrated the highly allergenic nature of the ten tested fungal antigens that may be due to a higher prevalence of such fungal forms in the surround ings of those tested.

Late Quaternary vegetational history of Upper Assam, India

Abstract Pollen diagrams made from the sub-surface Late Quaternary sediments of Upper Assam, India, reveal palaeoecological and vegetational patterns which include associations of a large number of temperate ferns and other subtropical/temperate plants. A peat sample at a depth of 1.80 m dates back to 17,930± 575 yr BP. The occurrence of north-east Asian elements like Carya, Pterocarya , and Tsuga suggests a trans-migratory link between India and countries of north-east Asia during the time of deposition which has been subsequently eliminated due to climatic change or some other natural phenomenon.

SU‐E‐T‐57: Estimation of Uncertainty in Dose Delivery Due to MLC Position Inaccuracies by Inverse Derivative Method during Volumetric Modulated Arc Therapy Delivery by Elekta Beam Modulator

Purpose: To investigate uncertainties in dose delivery (UDD) due to MLC positional inaccuracies during Volumetric Modulated Arc therapy (VMAT) delivery by Elekta Beam ModulatorLINAC.Methods: In Beam Modulatorfield size is defined by MLCs. In VMAT the field aperture χ is a function of the gantry angular speed ω and position of ith MLC Xi {=f (t)} at time t (χ=f(ω, dXi/dt)). The absorbed dose to EPID (DTW) is defined as a function of ω and dXi/dt; DTW=f(ω, dXi/dt). dDTW/dχ vs. χ calibration curve was generated, in Am‐Si EPID, using higher than dmax buildup (2 cm) for a square field length of 0.8 to 3.2 cm for 6MV beam. MLCs were interrupted at some intermediate position (single or multiple time, in later case average error was considered) of the VMAT delivery and projection images were taken in EPID. Uncertainties in field definition were calculated by Δχ = Σ ΔXi * MLC width. UDD was calculated from dDTW/dx vs. χ calibrationcurve. Results: The MLCs move with linear, parabolic or circular velocity at 0.5, 1, 1.5, 2 and 2.5 cm/sec having dose rate 35, 70, 140, 280, 560 MU/min. UDD was determined for all combinations of these dose rate and MLC velocities for 101 MLC defined fields. Maximum and minimum UDD of 0.2 cGy/mu and 0.004cGy/mu were obtained for 560MU/min‐1.5cm/sec and 35MU/min‐2.0cm/sec respectively. Mean uncertainty in UDD was 0.15 cGy/MU with a standard deviation of 0.045. Conclusions: Mean UDD obtained was high (15%) and its not the peripheral dose uncertainty. The UDD evaluated for either single or three interruptions, considering that in MLC movement will show similar behavior during their rest of the motion. Actually this fact was observed for multiple interruption cases. Nevertheless if its possible to measure Δχ for each control point, by cine mode in EPID, better results can be obtained.