A test of the counting of elephants from the air

Aerial counts of elephants made three times a day over the same region tended to be consistent if due allowance is made for observed movements to and from the area. There was little difference between observers when two were present. Ground counts made on the same day as the aerial counts tended to return lower totals, due probably to elephants in dense vegetation being hidden from the ground observer but visible from the air. It is concluded that aerial survey is the most efficient way of counting elephants, at least in the Queen Elizabeth National Park.     

Expression of bacteriophage M13 DNA in vivo. Localization of the transcription initiation and termination signal of the mRNA coding for the major capsid protein.

During the infection cycle of the filamentous bacteriophage M13 a phage specific RNA species is made which selectively directs in vitro the synthesis of the precursor of the major capsid protein encoded by gene VIII. This RNA is unstable (its mean half-life is 11 min) and is made in amounts representing at least 2% of the newly synthesized RN. Nucleotide sequence analysis have indicated that the synthesis of this RNA species is initiated and terminated at the same promoter (G0.18) and termination signal (T0.25) of the M13 genome as the 8S RNA species made in vitro under the direction of M13 replicative form DNA.     

Variants of the agglutination reaction: the present and future

The methodological analysis of the main problems of serological diagnosis has made it possible to pick out the tests of the agglutination type, especially those made with the use of sensitized erythrocytes, as most suitable for mass use. The comparison made between different agglutination tests has confirmed the fact that the use of sensitized erythrocytes in such tests is highly effective. The comparison of the diagnostic possibilities of agglutination tests involving the use of erythrocytic reagents with those offered by enzyme immunoassays has demonstrated that tests based on the phenomenon of passive hemagglutination have great possibilities and hold considerable promise not only for mass immunological surveys, but also for research work.     

Strong-polar mutations in the transferase gene of the galactose operon in E.coli

Summary A class of mutations in the transferase gene of the galactose operon in E. coli is described, which is strongly polar for the synthesis of kinase. The latter enzyme is made only to the extent of about 0.1% of the amount made in the induced wildtype. This amount is not dependent on the map position of the mutations and the residual synthesis is non-inducible. The mutants thus resemble 0° mutants in the same operon.Epimerase, which is coded for by the gene proximal to the transferase gene with respect to the operator, is made in normal amounts and its synthesis is normally inducible.The mutants do not seem to belong either to the nonsense or to the frameshift class on the basis of reversion pattern, suppressibility, and degree of polarity. The possible nature of the mutations is discussed.     

Freshwater Diatomflora of the Panhalgarh Hillfort in the Kolhapur district

Synopsis This is an account on the freshwater Diatomflora of the Panhalgarh hills in the Kolhapur district based on collections and studies made during different seasons of the years 1953–1956. Besides the taxonomical studies, it is also endeavoured here to present notes on ecology, occurrence and distribution of these diatoms. A suggestion also has been made, wherever possible, regarding their form- change occurring during their reproduction or otherwise under the influence of varying climatic conditions.     

The Theoretical and Empirical Foundations of the Sociocultural-Interdeterminist Dialogical Metatheory of the Integration of Psychological Knowledge

This article examines the problem of finding the theoretical and empirical foundations of the integration of psychological knowledge in the context of a sociocultural-interdeterminist dialogical metatheory. An argument is made for the idea of the four-dimensionality of the continuums of psychological phenomenology, of which the universal systemic foundation is culture. Heteroqualitative, multidimensional, and multiparadigm psychological knowledge is conceptualized in the form of three four-dimensional continuums. Based on the introduced principle of dialogical interdeterminism, a case is made that the interaction among their constituent structural elements is interdeterminist in character. Theoretical and empirical substantiation is presented for the innovativeness of the approach.     

Model connective tissue systems: the effect of proteoglycans on the distribution of small non-electrolytes and micro-ions

Donnan equilibria between solutions of various carbohydrates polyins and Na^⊕ have been measured by equilibrium dialysis. From the results, estimates have been made of the degree of Na^⊕ fixation by the polyions. Comparison is made between the behavior of the complex proteoglycan macromolecules and their constituent glycosaminoglycans. Attempts to interpret these results and the Na^⊕ activity in saltfree solutions on the parameter of the intercharge distance has been made. By use of studies on carboxymethylcellulose, the relative importance of the carboxyl and of the sulphate ester groups in the Na^⊕ fixation is assessed. The relevance of the measurements to the previously described diffusional effects found in real and model connective tissues is discussed.     

Fragmentation of polyploid nuclei in the giant cells of the rat trophoblast. I. The ultrastructure of the nuclear fragments

Electron microscope study of the nuclear fragments in the rat trophoblast has demonstrated that the division of the trophoblast giant nucleus results first in the formation of a multinuclear cell. Each nuclear fragment is covered with its own nuclear envelope made of two membranes with numerous pore complexes. The chromatin in these nuclear fragments is condenced with various degrees of condensation, which depends on the step of placenta development, cell differentiation and the degree of nuclear fragmentation. The nuclear ultrastructure in nuclear fragments also depends on the degree of nuclear fragmentation and on the level of chromatin condensation. The nucleolus has no granular component. On large fragments, with lower chromatin condensation the nucleolus is not homogenous being made of fragments of more and of less electron dense fibrilles. Small light lacunae are seen in the nucleolus where chromatin threads and strands pass on. With a high chromatin condensation in the nucleus, round small nucleoli look homogenous being made of moderately electron dense fibrilles. Products of chromosome activity have been found in the nuclear fragments: accumulations of minute granules (d = 15--20 nm), perichromatinous granules (d = 35--40 nm), and fibrillar nucleolus-like bodies. In the multinuclear cell, made as the result of fragmentation of the initially giant nucleus, all the small nuclei are first arranged very close to each other, so that the contours of the neighbouring nuclei coincide.     

Reconstituted high density lipoprotein behaviour is modified by the nature of the lipid vesicle

Apo HDL is a more potent inhibitor of lipoprotein lipase than native HDL. HDL reconstituted from apo HDL and vesicles made from either HDL total lipids or HDL phospholipids inhibits lipoprotein lipase in the same manner as native HDL. HDL reconstituted from apo HDL and vesicles made from phosphatidylcholine and sphingomyelin still behaves like apo HDL.     

Optimization of the determination of RNA nucleotide composition by ultraviolet spectral analysis

We have optimized the spectrophotometric method for the quantitative analysis of a tetranucleotide mixture (for example an RNA hydrolysate) by carefully choosing the wavelengths and the pH at which the absorbance measurements were made, and estimated the error made on the calculated concentration of each nucleotide. The most convenient method involved the measurement of only four absorbances (at 228 nm at pH 13; 200, 212 and 284 nm at pH 2). If the sensitivity of the spectrophotometer is 0.001 unit absorbance, the absolute error made on the calculated percentage of each nucleotide is lower than 0.33%.     

Prediction of the secondary structure of the carboxy-terminal third of rat thyroglobulin

A secondary structure prediction has been made using the available primary sequence data of the proposed carboxy-terminal of rat thyroglobulin. The model predicts 22% alfa-helix, 28% beta-structure and 17% beta turns. Out of the 8 possible carbohydrate acceptor-sites (Asn-x-Ser/Thr), 3 (residues 136, 368, 782) are associated with peptide sequences which favour the formation of beta-turn or loop-structures and are located in high hydrophilic regions. The entire sequence is predicted to be made up of two domains: one of them is highly structured, contains the hormonogenic sites, a cluster of tyrosines and at least one carbohydrate acceptor site.     

Evaluation of the system for controlling the quality of the HBsAg detection in the system of screening laboratories

The two-stage control system, ensuring the high quality of serological investigations in the network of screening laboratories in Moscow was developed and introduced into practice. At the first stage the entry control of the quality of the test system for the detection of HbsAg, coming to the screening laboratories, is made in the reference laboratory with the use of specially developed "representative" panels, as well as the test systems for comparison ("reference" test systems). Then "minipanels" are formed from specimens included into the "representative" panels, which are used for the evaluation of the quality of laboratory investigations made in the screening laboratories. The high quality of such system for controlling the quality of the detection of HBsAg in the screening laboratories of Moscow is shown.     

Study of the kinetics of thermoinactivation of lysyl-tRNA-synthetase from the liver of x-irradiated rats

A study was made of the kinetics of thermoinactivation of lysyl-tRNA-synthetase isolated from rat liver at early times of radiation damage development after the effect of a minimum absolutely lethal X-radiation dose (0.21 C/kg). The thermostability of a dimer form of the enzyme was shown to be higher than that of a monomer. It was established that substrates had a stabilizing effect on the enzyme during thermoinactivation. On the basis of the data obtained from the studies in the kinetic properties of the enzyme and the thermoinactivation a conclusion is made that lysyl-tRNA-synthetase is stabilized during subunit aggregation. The thermostability of the enzyme was decreased by irradiation.     

On the vertical distribution of pelagic tunicates in relation to the water masses in the western part of the Bay of Bengal

A study on the vertical distribution of pelagic tunicates in relation to the water masses in the western part of the Bay of Bengal is made. Their depth distribution has clearly pointed out that while some pelagic tunicates are primarily associated with water conditions similar to those of the Northern Dilute Water and Transition Water, the others were associated with the water conditions similar to those of the Southern Bay of Bengal Water and Upwell Water. The present study supports the observations made earlier on the horizontal and depth distribution of pelagic tunicates in the western part of the Bay of Bengal.     

A synopsis of calculations of the energy band structures for protein molecules

A review is given of the theoretical approaches that have been made to understand and describe the electronic energy band structures for protein molecules. In recent years significant progress has been made, and it is now clear that a theoretical basis does exist for the possibility that the electronic conduction properties of proteins are of biological relevance.     

On the theory of cell division from the point of view of the principle of maximum energy exchange

An analysis is made of the equation of cellular elongation during division, which was derived by N. Rashevsky from the principle of maximum energy exchange. The method used is the same as that employed by H. D. Landahl in discussing a similar equation deduced from the theory of diffusion drag forces. The differential equation is expanded in a power series of the relative elongation, and in this way is reduced to the form studied by H. D. Landahl, which has been shown to agree very well with experimental data. An estimate of the order of magnitude of the universal constant τ, which appears in the generalized Hamiltonian principle, is made, and τ is found to be of the order of 10⁻⁴ sec.     

用铁蛋白合成纳米粒子的研究进展

铁蛋白是一种生物储铁蛋白 ,其储存铁的特性和储存铁在生物体内的特殊形态 ,通过相对温和、简便的生物、化学、物理过程 ,可合成多种具有特异的力、热、光、电、磁等特性的纳米粒子 ,并可用来构建纳米级的分子器件     

Recent breakthroughs in the study of salicylic acid biosynthesis

Salicylic acid is an important regulator of induced plant resistance to pathogens. Consequently, the biosynthesis of salicylic acid and its regulation has received a lot of attention. Salicylic acid can be made from phenylalanine via cinnamic and benzoic acid. Recently, genetic studies in Arabidopsis have shown that salicylic acid is made in the chloroplast from isochorismate, a pathway that is known to operate in prokaryotes.     

A comparison between the inlet and outlet diameters of the normal aortic valve.

Two studies are described comparing the inlet and outlet diameters of the normal aortic valve. Both studies show the valve inlet to be smaller than the valve outlet. The first study is of measurements made on 12 casts of physiologically pressurised human aortic valves. The mean ratio between the diameter of the aortic ring and of the aorta just distal to the sinus ridge was 1.1, and the mean ratio between the diameter of the aortic ring and the maximum diameter of the valve leaflets was 1.18. The second study presents echocardiographic data from normal volunteers. The mean ratio between the diameter of the aortic ring and of the aorta just distal to the sinus ridge was 1.17. It is suggested that stents made to support the leaflets of prosthetic valves are made in conical or hyperbolic form, with the outlet being approximately 20% larger than the inlet.