Purification and properties of heat-resistant exotoxin produced by Macrophomina phaseolina (Tassi) Goid in culture.

A partially purified preparation of a water-soluble, heat-resistant, nonspecific exotoxin produced by a strain of Macrophomina phaseolina, isolated from Phaseolus mungo L. could reduce Cu++ ions and produced a red colour with 2,4-dinitrophenyl hydrazine reagent. It caused inhibition of seed germination, wilting of cult seedlings, stunted growth of young seedlings and loss of permeability of the cell membrane. Seedlings of P. mungo, grown in presence of the toxin showed a slight increase in the contents of protein and total RNA over control, but a significant increase in the specific activities of F-1, 6-BP aldolase and G-6-P isomerase.     

Variations in DNA content

Summary DNA content in the active nuclei of various plant organs varies from organ to organ. The amount of DNA in the shoot tip is the least, as compared to that of other organs. The amplification of DNA in the differentiation of organs from the shoot meristem has been suggested.     

C-band positive W chromosome in the female Indian frog

Summary In the female Indian frog,Rana tigrina (2n=26; NF=52), the female is heterogametic. The heterochromosomes (ZW) are morphologically indistinguishable, but the W chromosome proves by C-banding analysis to be entierly heterochromatic.Acknowledgment. S.C. is grateful to Prof. G.K. Manna, Zoology Department, Kalyani University, Prof. Archana Sharma, Botany Department, Calcutta University and to Prof. T. Sharma, Zoology Department, Banarus Hindu University for encouragements. He is also thankful to Prof. D.K. Choudhuri, Burdwan University for support.     

Factor forecasts for the UK

Data are now readily available for a very large number of macroeconomic variables that are potentially useful when forecasting. We argue that recent developments in the theory of dynamic factor models enable such large data sets to be summarized by relatively few estimated factors, which can then be used to improve forecast accuracy. In this paper we construct a large macroeconomic data set for the UK, with about 80 variables, model it using a dynamic factor model, and compare the resulting forecasts with those from a set of standard time‐series models. We find that just six factors are sufficient to explain 50% of the variability of all the variables in the data set. These factors, which can be shown to be related to key variables in the economy, and their use leads to considerable improvements upon standard time‐series benchmarks in terms of forecasting performance. Copyright © 2005 John Wiley & Sons, Ltd.     

Preferential cytotoxicity on tumor cells by caffeic acid phenethyl ester isolated from propolis

Summary The honeybee hive product, propolis, is a folk medicine employed for treating various ailments. Many important pharmaceutical properties have been ascribed to propolis, including anti-inflammatory, antiviral, immunostimulatory and carcinostatic activities. Propolis extracts have provided an active component identified as caffeic acid phenethyl ester (CAPE), which was readily prepared in one step. Differential cytotoxicity has been observed in normal rat/human versus transformed rat/human melanoma and breast carcinoma cell lines in the presence of CAPE.     

Microbial leaching of chromite overburden from Sukinda mines, Orissa, India using Aspergillus niger

Leaching of nickel and cobalt from two physical grades (S1, 125–190 μm, coarser and S3, 53–75 μm, finer) of chromite overburden was achieved by treating the overburden (2% pulp density) with 21-d culture filtrate of an Aspergillus niger strain grown in sucrose medium. Metal dissolution increases with ore roasting at 600°C and decreasing particle size due to the alteration of microstructural properties involving the conversion of goethite to hematite and the increase in surface area and porosity as evident from X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (DT-TGA), and field emission scanning electron microscopy (FESEM). About 65% Ni and 59% Co were recovered from the roasted S3 ore employing bioleaching against 26.87% Ni and 31.3% Co using an equivalent amount of synthetic oxalic acid under identical conditions. The results suggest that other fungal metabolites in the culture filtrate played a positive role in the bioleaching process, making it an efficient green approach in Ni and Co recovery from lateritic chromite overburden.     

Regulation of circadian behaviour and metabolism by synthetic REV-ERB agonists

Synchronizing rhythms of behaviour and metabolic processes is important for cardiovascular health and preventing metabolic diseases. The nuclear receptors REV-ERB-α and REV-ERB-β have an integral role in regulating the expression of core clock proteins driving rhythms in activity and metabolism. Here we describe the identification of potent synthetic REV-ERB agonists with in vivo activity. Administration of synthetic REV-ERB ligands alters circadian behaviour and the circadian pattern of core clock gene expression in the hypothalami of mice. The circadian pattern of expression of an array of metabolic genes in the liver, skeletal muscle and adipose tissue was also altered, resulting in increased energy expenditure. Treatment of diet-induced obese mice with a REV-ERB agonist decreased obesity by reducing fat mass and markedly improving dyslipidaemia and hyperglycaemia. These results indicate that synthetic REV-ERB ligands that pharmacologically target the circadian rhythm may be beneficial in the treatment of sleep disorders as well as metabolic diseases.     

Effect of light and darkness on the hypothalamo-neurohypophyseal system of the garden lizard,Calotes versicolor

Résumé Nous avons étudié l'effet d'une l'illumination continue ou d'une obscurité de 7 jours sur le système hypothalamique neurosécréteur (HNS) du lézard des jardinsCalotes versicolor. L'illumination a stimulé le HNS par activation de la synthèse, du transport et de la libération de la neurohormone(s) tandis que l'obscurité a fait diminuer la quantité libérée de neurohormone de la pars nervosa.