Effect of botanicals on the population dynamics ofNephotettix virescens, rice tungro disease incidence and yield of rice

Leaf extracts ofVitex negundo L,Synadenium grantii Hook. f. andProsopis juliflora (SW) DC, and cake ofAzadirachta indica A. Juss. were evaluated for their efficacy in reducing the population of the green leafhopper,Nephotettix virescens (Distant), and its transmission of rice tungro virus under field conditions. All four plant species tested reduced the population of the vector significantly in both the nursery and main field. The lowest population of the vector was recorded with application of neem cake at 5 kg/0.032 ha of nursery, followed by foliar spray of neem seed kernel extract at 5% in the main field. Rice tungro disease incidence was also less in this treatment, with maximum grain yield of 3580 kg/ha in ‘Kharif’ (July-Oct.) and 3257 kg/ha in ‘Rabi’ (Nov.-March) seasons, and a cost:benefit ratio of 1:3.9 in both seasons. However, the maximum cost:benefit ratio of 1:5.6 and 1:5.8 in Kharif and Rabi seasons, respectively, was recorded withV. negundo.     

Crystal Structure of Tl2Ba2Ca2Cu3O10, a 125 K Superconductor

There is now a new series of high-temperature superconductors that may be represented as (A(III)O)(2)A(2)(II)Can-1CunO2+2n where A(III) is Bi or Tl, A(II) is Ba or Sr, and n is the number of Cu-O sheets stacked consecutively. There is a general trend toward higher transition temperatures as n increases. The highest n value for a bulk phase is three and is found when A(III) is Tl. This compound, Tl(2)Ba(2)Ca(2)Cu(3)O(10), has the highest transition temperature( approximately 125 K) of any presently known bulk superconductor. The structure of Tl(2)Ba(2)Ca(2)Cu(3)O(10) has been determined from single-crystal x-ray diffraction data and is tetragonal, with a = 3.85 A and c = 35.9 A. No superstructure is observed, and the material is essentially twin-free. Electron microscopy in the Tl/Ba/Ca/Cu/O system has revealed intergrowths where n = 5; such regions may well be responsible for the superconducting onset behavior observed in this system at about 140 K.     

Anomalous scattering study of the bi distribution in the 2212 superconductor: implications for cu valency

The distribution of the bismuth atoms over the cation sites in the 2212 Bi-Sr-Ca-Cu-O superconductor has been determined by anomalous scattering synchrotron crystallography. The analysis of reflection pairs measured at wavelengths of 0.9243 and 0.9600 angstrom shows a delocalization of the bismuth atoms over the calcium and strontium sites. The "mixed" plane between the CuO(2) layers contains 6.0(1.4) percent bismuth (where the number in brackets represents the statistical standard deviation derived from the least-squares refinement of the data), and a much smaller amount of strontium than often assumed. The strontium deficiency is charge-compensated by the creation of electron holes in the CuO(2) layer. The result supports the view that neither extra oxygen nor overlap of the bismuth 6p and copper 3d bands is needed to account for the holes, which are an essential feature of the superconductivity mechanism.     

Use of resistant ACCase mutants to screen for novel inhibitors against resistant and susceptible forms of ACCase from grass weeds

The aryloxyphenoxypropionic acid (AOPP) and cyclohexanedione (CHD) herbicides inhibit the first committed enzyme in fatty acid biosynthesis, acetyl CoA carboxylase (ACCase). The frequent use of AOPP and CHD herbicides has resulted in the development of resistance to these herbicides in many grass weed species. New herbicides that inhibit both the susceptible and resistant forms of ACCase in grass weeds would have obvious commercial appeal. In the present study, an attempt was made to identify molecules that target both the herbicide-sensitive and -resistant forms of ACCase. Seven experimental compounds, either CHD-like or AOPP-CHD hybrids, were synthesized and assayed against previously characterized susceptible and resistant forms of ACCase. All seven compounds inhibited ACCase from sensitive biotypes of Setaria viridis and Eleusine indica (I50 values from 6.4 to >100 microM) but were not particularly potent compared to some commercialized herbicides (I50 values of 0.08-5.6 microM). In almost all cases, the I50 values for each compound assayed against the resistant ACCases were higher than those against the corresponding sensitive ACCase, indicating reduced binding to the resistant ACCases. One compound, a CHD analogue, was almost equally effective against the resistant and susceptible ACCases, although it was not a very potent ACCase inhibitor per se (I50 of 51 and 76 microM against susceptible ACCase from S. viridis and E. indica, respectively). The AOPP-CHD hybrid molecules also inhibited some of the resistant ACCases, with I50 values ranging from 6.4 to 50 microM. These compounds may be good leads for developing ACCase inhibitors that target a wider range of ACCase isoforms, including those found in AOPP- and CHD-resistant weed biotypes.     

Accumulation of genistein and daidzein, soybean isoflavones implicated in promoting human health, is significantly elevated by irrigation

To circumvent drought conditions persisting during seed fill in the mid-south U.S. soybean production region, researchers have developed the early soybean (Glycine max [L.] Merr.) production system (ESPS), which entails early planting of short-season varieties. Because soybean supplies a preponderance of the world's protein and oil and consumption of soy-based foods has been associated with multiple health benefits, the effects of this agronomic practice on seed quality traits such as protein, oil, and isoflavones should be investigated. Four cultivars of soybean, two from maturity group IV and two from maturity group V, were planted in April (ESPS) and May (traditional) in a two-year study at Stoneville, MS. Near-infrared analysis of soybean seed was utilized to determine the percentages of protein and oil. Dependent upon variety, the oil content of the early-planted crop was increased by 3-8%, whereas protein was not significantly changed. Visualization of protein extracts fractionated by sodium dodecyl sulfate-polyacrylamide electrophoresis and fluorescence two-dimensional difference gel electrophoresis revealed that early planting did not affect the relative accumulation of the major seed-storage proteins; thus, protein composition was equal to that of traditionally cultivated soybeans. Maturity group IV cultivars contained a higher percentage of oil and a lower percentage of protein than did the maturity group V cultivars, regardless of planting date. Gas chromatographic separation of fatty acids revealed that the percentages of saturated and unsaturated fatty acids were not significantly altered by planting date. Methanol extracts of seed harvested from different planting dates when analyzed by high-performance liquid chromatography showed striking differences in isoflavone content. Dependent upon the variety, total isoflavone content was increased as much as 1.3-fold in early-planted soybeans. Irrigation enhanced the isoflavone content of both early- and late-planted soybeans as much as 2.5-fold. Accumulation of individual isoflavones, daidzein and genistein, was also elevated by irrigation. Because this cultural practice improves the quality traits of seeds, ESPS provides an opportunity for enhancing the quality of soybean.     

Transport and distribution of heavy metals in Cauvery river

Heavy metal transport in Cauvery river chiefly takes place in the particulate form. Tributaries Hemevathi and Kabini draining highly mineralized areas contribute significantly to the heavy metal load of the Cauvery river. Particulate metal transport is influenced by the presence of major dams built across the river. Factor analysis of the elemental data identifies two major group of heavy metals, (a) Fe, Mn, Cr, V and Ti and (b) Cu, Pb and Zn in the suspended sediments of Cauvery river. Heavy metals in surface sediments show wide variations in their concentrations due to the non-uniform grain size distribution of the sediments. The elements Fe, Mn, Pb, Cu, Zn, Ni, Co and As are dominantly present in the <20 μm fraction of the river sediments. Speciation studies show that Fe-Mn oxide phase held the largest share of heavy metals in the sediments. The depth variation of heavy metals in the core sediments suggest their similar mobility during diagenesis. Geoaccumulation indices calculated suggest that Cd, Zn, Cr, Pb, Cu and Ni are enriched in sediments several times over background values.     

Seedling Peroxidase and IAA Oxidase Activities in Relation to Hybrid Vigour in Pearl Millet (Pennisetum americanum L. Leeke)

Seedlings of three hybrids and their parental lines were analyzed for growth, and peroxidase as well as IAA oxidase activities in cytoplasmic and salt-extracted ionically bound fractions with a view to evaluate heterosis in pearl millet. The hybrid vigour was manifested in roots and shoots of all the three hybrids clearly for growth and activities of peroxidase and IAA oxidase except the wall-bound IAA oxidase. Either better parental or mid-parental heterosis was discernible. The role of peroxidase and IAA oxidase systems in meristematic activity and removal of excessive auxin levels to bring about maximal growth response in the hybrids is discussed.     

Neuroendocrine tumor in the lung of a captive black spider monkey (Ateles paniscus)

This paper describes a neuroendocrine (NE) tumor of the lung that was observed during the necropsy of a 14-year-old female black spider monkey (Ateles paniscus) with sudden death. Grossly, multifocal firm and coalescing nodular masses were observed in the lung. The histological examination showed the tumor to be an typical NE tumor with polygonal cells grouped in small solid aggregates, with regularly sized, spherical, centrally placed nuclei with modest, lightly granular cytoplasm suspended in a fibrovascular stroma. The immunohistochemical examination revealed the tumor to be positive for cytokeratin, chromogranin A and synaptophysin, and negative for CD56. To the best of our knowledge, this is the first report of NE tumor in the lung of the black spider monkey.