The photochemical decomposition of the herbicide isoproturon

The photochemical degradation of the herbicide isoproturon in aqueous and non-aqueous solutions and in soils has been investigated. Four new photometabolites were formed in non-aqueous solution and three in soil. These were characterised by spectroscopic methods and identified by comparison with authentic synthetic samples such as 3-(4-isopropylphenyl)-1-methylurea; 3-(4-isopropylphenyl)urea; 4,4′-diisopropylazobenzene and 4,4′-diisopropylazoxybenzene. The pathway of formation of these photo products is depicted.     

Establishment of Prosopis cineraria (L.) druce in the hot deserts of India

Prosopis cineraria (L.) Druce, commonly known as Jandi, is a deep rooted, nitrogen fixing, multipurpose tree endemic to the hot deserts of India. These trees are the essential component of the agroforestry land use system in these parts of India. The shade-intolerant tree reproduces poorly in nature and is difficult to propagate vegetatively. Germination up to 86.6% was observed after 15 days in seeds soaked in water at room temperature for 72 h. In another treatment, pouring of boiling water twice (at 0 and 6 h) over seeds and germinating after 12 h produced germination rates of 92.6%. Field establishment of containerized transplants in polythene bags (22×10 cm; 150 gauge) gave 90.3% survival after 6 months and 75.4% survival after 24 months. Seedlings were irrigated once during transplanting with 15 1 water. Bare root transplants and manual direct seeding after 6 months had a survival of 30.8 and 45.0%, respectively. Increased levels of nutrients (N, P and K), moisture content and organic carbon were observed under plantations as compared to open areas.     

Viability retention of seeds of shisham (Dalbergia sissoo Roxb.) on the trees after maturity

In 1991 and 1992 studies on Dalbergia sissoo Roxb. showed the availability of ample amount of viable seed from November to May. Viability of seeds collected from December to March was more than 90 per cent. There was a slight but significant decrease in germination from March to may. Again germination per cent was slightly and significantly decreased from May to July. Thereafter, seed availability and viability were got drastically reduced. Sufficient viable seed of Dalbergia sissoo Roxb. can be collected at any time from November to July.     

Influence of feeding regime on intraspecific competition, fin damage and growth in 1+ Atlantic salmon parr (Salmo salar L.) held in freshwater production cages

The feeding behaviour, growth and feed conversion ratio (FCR) of cage‐held Atlantic salmon parr (Salmo salar L.) were studied when in 576 m³ (12 m × 12 m × 4 m) commercial freshwater cages under ambient water temperature (8.84±3.53°C) and photoperiod (11.02±2.05 h) for 205 days. The effect of feeding regime on fin damage was also investigated. Six groups (n=31 234±2051 fish group⁻¹, initial stocking density 1.25±0.14 kg m⁻³) were fed to satiation using either (a) an imposed regime involving scheduled, fixed ration feeding every 10 min from dawn till dusk or (b) on demand from dawn till dusk using commercial interactive feedback systems. During feeding, there were no significant differences in aggression although swimming speeds and turning angles were significantly higher in fish under the imposed regime. On‐demand feeding significantly reduced the incidence of dorsal fin damage. There was no clear relationship between fish size, feed regime and the incidence of fin damage until 1 week before the fish were transferred to marine cages, when the smallest fish under each feeding regime had the highest incidence of fin damage. Interestingly, growth did not differ between regimes, but fish under the imposed regime were significantly overfed and achieved higher FCRs.     

The impact of initial concentration of selected pharmaceuticals on their early stage of dissipation in soils

Journal of Soils and Sediments - Dissipation of pharmaceutical compounds entered into the natural environment is an important process minimizing the adverse effects on the living organisms. The aim...     

Use of apigenin from Cordia dichotoma in the treatment of colitis

Cordia dichotoma f. (Boraginaceae) is a small deciduous tree from India. The bark of was used in the treatment of ulcerative colitis (UC) and colic pain traditionally hence present work was undertaken to identify the phytoconstituent responsible for this activity. Apigenin is isolated by column chromatography from methanol fraction of crude methanol extract of C. dichotoma bark. Structure of apigenin is established by various spectroscopic studies. Apigenin (5 mg/kg, p.o.) showed significant healing and reduction in inflammatory enzymes when screened for UC. It can be concluded that apigenin from C. dichotoma bark may be responsible for the treatment of UC.     

Composition and diversity of five major forest types in moist temperate climate of the western Himalayas

The present study was undertaken in five major forest types (dominated by Quercus semecarpifolia, Quercus floribunda, Acer acuminatum, Abies pindrow and Aesculus indica, respectively) between 2400 and 2850 m a.s.l. in a moist temperate forest of the Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim was to assess the variation in composition and diversity in different vegetation layers, i.e., herb, shrub and tree, among these five forest types. Diversity indices, such as the Shannon-Wiener diversity index, density, total basal cover, Simpson’s concentration of dominance index, Simpson’s diversity index, Pielou’s equitability, species richness, species heterogeneity and β-diversity, were calculated to understand community structures. Dominance-diversity curves were drawn to ascertain resource apportionment among various species in different forest types.     

A Suitable Site for in situ (On-farm) Management of Plant Diversity in Traditional Agroecosystems of Western Himalaya in Uttaranchal State: A Case Study

There is a growing realisation world over that the introduction of modern agriculture has to be supplemented with measures to conserve biodiversity in situ if yield gains are to be stabilized. Hence, there is a growing interest from agricultural development specialists and conservation biologists for understanding the socioeconomic factors determining the conservation of biodiversity in situ. The present study was conducted with the objective of understanding the in situ (on-farm) conservation of agrobiodiversity in traditional agroecosystems taking the Urgam valley in north-western Himalaya of India, as a case study. An inventory was made of traditional crops and wild economic species for subsistence, and the structure of forest resource base, traditional knowledge related to resource management and use. Institutional and scientific challenges for in situ (on-farm) management of crop diversity were studied and are discussed in this paper. Complementarity of in situ (on-farm) conservation with ex situ conservation together with crop improvement in such marginal areas are suggested.     

Analysis of genetic diversity in Piper nigrum L. using RAPD markers

RAPD analysis was conducted in 22 cultivars of P. nigrum(black pepper) from South India and one accession each of P. longum and P. colubrinum. Twenty-four primers generated 372 RAPD markers of which 367 were polymorphic. Jaccard's similarity between pairs of accessions ranged between 0.11 and 0.66 with a mean of 0.38. Among P. nigrum cultivars, the similarity ranged between 0.20 and 0.66 and the mean was 0.42. The existence of wide genetic diversity as revealed in the present study is supported by earlier reports of extensive inter- and intrapopulation morphological variability in pepper cultivars from South India. UPGMA dendrogram and PCO plot revealed P. colubrinum to be most distant of the three species. Genetic proximity among P. nigrum cultivars could be related to their phenotypic similarities or geographical distribution. Greater divergence was observed among landraces than among advanced cultivars. Landraces grown in southern parts of coastal India and those grown in more northern parts were grouped in separate clusters of the dendrogram.     

Two-dimensional nanosheets produced by liquid exfoliation of layered materials

If they could be easily exfoliated, layered materials would become a diverse source of two-dimensional crystals whose properties would be useful in applications ranging from electronics to energy storage. We show that layered compounds such as MoS(2), WS(2), MoSe(2), MoTe(2), TaSe(2), NbSe(2), NiTe(2), BN, and Bi(2)Te(3) can be efficiently dispersed in common solvents and can be deposited as individual flakes or formed into films. Electron microscopy strongly suggests that the material is exfoliated into individual layers. By blending this material with suspensions of other nanomaterials or polymer solutions, we can prepare hybrid dispersions or composites, which can be cast into films. We show that WS(2) and MoS(2) effectively reinforce polymers, whereas WS(2)/carbon nanotube hybrid films have high conductivity, leading to promising thermoelectric properties.