The region Ser333-Arg356 of the alpha-chain of human C4b-binding protein is involved in the binding of complement C4b

Human C4b-binding protein (C4BP) functions as a cofactor to factor I in the degradation of C4b and accelerates the decay rate of the C4b2a complex. In this study we describe a monoclonal antibody directed against the alpha-chain of C4BP that inhibits the binding of C4b to C4BP. In order to identify the structural domain of the alpha-chain of C4BP that interacts with C4b, tryptic fragments of C4BP were generated. Amino acid sequence analysis of the fragments revealed that the residues Ser333-Arg356 of the alpha-chain of C4BP contain the epitope of this antibody, and as a consequence, that this part of the alpha-chain of C4BP is likely to be involved in the interaction with C4b.     

Collection of biological materials in biodiversity prospecting in India: problems and solutions

Forests are the chief resource for the collection and exploration of biological materials. The past few decades have witnessed a large scale deforestation in India due to substantial pressures generated by population growth, leading to demand for more land for agriculture, urbanization and industrial activities, in addition to increased demand for fuel wood and timber. This has resulted in the loss of soil cover, habitat destruction, environmental degradation and ecological imbalance. This scenario has created a progressive awareness for the conservation and restoration of habitats and, thus, the declaration of many forest areas into protected zones, such as national parks, biosphere reserves, etc., including the protection of some marine areas, by both the National and State Governments. Normally, permission for biological collecting is not granted in these protected areas. In India, forests are a State subject and grant for collection permission is vested with the State Forest Departments. In the absence of any rules, regulations and guidelines, either from National or State Governments, forest authorities impose their terms and conditions, which are arbitrary and even contradictory at times, in the process of granting collecting permits. A set of new rules to be applied throughout the country is needed.     

Apparatuses of the mustang family: A new page in laser therapy

Translated from Metallurg, Vol. 39, No. 6, p. 45, June, 1995.     

On the Theory of Electrical Phenomena in Combustion of Heterogeneous Systems with Condensed Products

The effect of the electromotive force arising in combustion of heterogeneous systems with condensed products is explained. A convective mechanism of arising regions with different charge densities due to charge transfer by the gas filtered in the pores is formulated on the basis of the developed physical concepts, estimates, and analysis of experimental data. Key words: combustion, electron emission, filtration, electromotive force.     

Control over the parameters of InAs-GaAs quantum dot arrays in the Stranski-Krastanow growth mode

The effect of the growth temperature on the density, lateral size, and height of InAs-GaAs quantum dots (QD) has been studied by transmission electron microscopy. With the growth temperature increasing from 450 to 520°C, the density and height of QDs decrease, whereas their lateral size increases; i.e., the QDs are flattened. The blue shift of the photoluminescence line indicates decreasing QD volume. The observed behavior is in agreement with the thermodynamic model of QD formation. The effect of lowering the substrate temperature immediately after the formation of QDs on the QD parameters has been studied. On lowering the temperature, the lateral size of QDs decreases and their density increases; i.e., the parameters of QD arrays tend to acquire the equilibrium parameters corresponding at the temperature to which the cooling is done. The QD height rapidly increases with cooling and may exceed the equilibrium value for a finite time of cooling, which enables fabrication of QD arrays with a prescribed ratio between height and lateral size by choosing the time of cooling.