Recent decrease in carbon sink to Russian forests

Regional Evaluation of Carbon Budget of Forests (RECBF), was used to study the dynamics of carbon balance in Russian forests in 1988–2015. The carbon sink (excess of absorption over losses) to forests was minimal in 1988. Since the first half of the 1990s, its increase has started. This increase was associated with the reduction of logging volume in connection with socioeconomic reforms. Since 2008, the carbon sink was gradually reduced due to increasing losses in logging operations, forest fires, and decreased carbon absorption.     

BOOK REVIEWS

Book reviewed in this article:
P hysical A nthropology : Yearbook of Physical Anthropology, 1947. G abriel W. L asker and J. L awrence A ngel
Yearbook of Physical Anthropology, 1948. G abriel W. L asker and F rederick P. T hieme     

Plasmacytoma of the breast. Unusual initial presentation of myeloma: report of two cases and review of the literature

Two patients who presented initially with breast masses proven to be plasmacytomas, are described. In both cases the breast masses led to the diagnosis of multiple myeloma, which was retrospectively already present at the time of the breast biopsy. One patient with IgG lambda-type myeloma developed plasma cell leukemia and amyloidosis and failed to respond to radiochemotherapy. The second patient was in complete remission, four years after therapy, but has subsequently relapsed and died. All cases of breast plasmacytoma, described in the medical literatures are reviewed, and guidelines for future therapy are suggested.     

Measurements of electron spin resonance with the pyruvate dehydrogenase complex from Escherichia coli. Studies on the allosteric binding site of acetyl-coenzyme A

Binding of the feedback inhibitor acetyl-coenzyme A to the pyruvate dehydrogenase complex from Escherichia coli was studied by electron spin resonance spectroscopy with the spin-labelled acetyl-CoA analogue 3-carboxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl-CoA-thioester. The spin-labelled compound binds to the pyruvate dehydrogenase component of the enzyme complex and this binding can be reversed by acetyl-CoA, while CoA has no effect. AMP and fructose 1,6-bisphosphate, which are both activators of the pyruvate dehydrogenase complex, exhibit a partial competition with the spin-labelled acetyl-CoA analogue and it could be shown that both activators act essentially by reversion of the feedback inhibition of acetyl-CoA. The binding site for these activators seems to overlap with the acetyl-CoA binding site, possibly by a common phosphate attachment point. No competition for binding to the feedback inhibition site exists with pyruvate, thiamine diphosphate, magnesium ions and with the fluorescent chromophore 8-anilino-1-naphthalene sulfonic acid. Thus, the feedback inhibition site proves to be a true allosteric regulatory site, which appears to be completely separate from the catalytic site on the pyruvate dehydrogenase component. The spin-labelled acetyl-CoA analogue binds also to the product binding site of acetyl-CoA on the dihydrolipoamide acetyltransferase component of the pyruvate dehydrogenase complex. Two binding sites per polypeptide chain with identical affinities on this enzyme component were found and the binding of the analogue can be inhibited by acetyl-CoA as well as by CoA.     

H-2-linked genetic control of the plaque-forming cell response to sheep red blood cells

The role of genes linked to the H-2 locus in effecting an immune response to SRBC was examined using strains of mice which differ in the classes of antibodies produced following multiple injections with SRBC. While H-2-linked gene action appeared to be at the level of regulating the number of plaque-forming cells (PFC) present in the spleens of different strains following two injections with SRBC, non-H-2-linked immune response genes seemed to determine whether an IgM-IgG switch occurred as well as how much of each antibody class was produced by the number of PFC available as a result of H-2-linked gene intervention. Mapping studies showed that the H-2-linked genetic effects were due to either the requirement for two genes or the presence of genes located between I-B and H-2D.     

Digestibility of the hydrogenated derivative of an isomaltooligosaccharide mixture by rats.

The digestibility of the hydrogenated derivative of an isomaltooligosaccharide mixture (IMO-H) was investigated. In an in vitro experiment, the digestibility of IMO-H was examined by models of the digestive system. IMO-H was resistant to two types of alpha-amylase and to artificial gastric juice. Enzymes in the rat small intestinal mucosa hydrolyzed tri-, tetra- and higher saccharide alcohols to disaccharide alcohol, removing successive glucose units from the non-reducing ends of the chains. The hydrolysis ratio for IMO-H was intermediate between the values for maltose and maltitol. In an in vivo study, growing rats were fed on an experimental diet containing IMO-H, maltitol, or hydrogenated palatinose in the range from 5% to 20%. The growth parameters of the rats fed on the test sugar show that the availability of IMO-H was about 1.2 to 1.25 times that of maltitol or hydrogenated palatinose.