A colorimetric assay for lignin based on its reaction with diazotized sulfanilic acid and its use in studies on lignin biodegradation by bacteria

Summary Studies on lignin biodegradation are considerably hampered by the lack of a simple analytical method. A rapid colorimetric assay for lignin has been developed using its reaction with a diazotized derivative of sulfanilic acid. Using such a method degradation of lignin, by an isolateErwinia sp. Cu3614, and by a genetically engineeredAcinetobacter PE7(pDPE2388) containing the arylether cleaving gene fromErwinia, has been followed.     

A comparison of different sources of information about pregnancy and childbirth

Different methods of obtaining information in medical and social research present problems of interpretation for the researcher. However, there are few systematic studies on the extent of the lack of concordance yielded by different methods. This paper uses data from a randomized controlled trial of social support in pregnancy to examine this issue in relation to three methods of data collection--medical records, home interviews and a postal questionnaire--on the following topics: obstetric history; smoking, alcohol use, number of antenatal hospital visits, bleeding and depression in pregnancy; length of labour; baby's sex, birthweight and neonatal health problems; and ethnicity. Considerable discrepancies are found comparing the different data sources. These suggest that mothers may be more reliable sources of information than medical records, and that the anonymity of a postal questionnaire may provide higher estimates than home interviews on some sensitive topics, such as smoking in pregnancy.     

Strontium-90 and caesium-137 in Indian tea

The paper presents results of measurements made on tea samples, collected during 1961-1979 period for their strontium-90 and caesium-137 content. Tea was found to contain higher concentration of these radioisotopes compared to other food-stuffs having vegetative origin. Levels in tea are compared with those in leafy vegetables from both India and Japan. Interpretation for higher concentrations in tea compared to leafy vegetables is briefly given on the basis of agro-climatic conditions. The levels are also considered from the point of view of health hazard.     

Fishers' knowledge and seahorse conservation in Brazil

From a conservationist perspective, seahorses are threatened fishes. Concomitantly, from a socioeconomic perspective, they represent a source of income to many fishing communities in developing countries. An integration between these two views requires, among other things, the recognition that seahorse fishers have knowledge and abilities that can assist the implementation of conservation strategies and of management plans for seahorses and their habitats. This paper documents the knowledge held by Brazilian fishers on the biology and ecology of the longsnout seahorse Hippocampus reidi. Its aims were to explore collaborative approaches to seahorse conservation and management in Brazil; to assess fishers' perception of seahorse biology and ecology, in the context evaluating potential management options; to increase fishers' involvement with seahorse conservation in Brazil. Data were obtained through questionnaires and interviews made during field surveys conducted in fishing villages located in the States of Piauí, Ceará, Paraíba, Maranhão, Pernambuco and Pará. We consider the following aspects as positive for the conservation of seahorses and their habitats in Brazil: fishers were willing to dialogue with researchers; although captures and/or trade of brooding seahorses occurred, most interviewees recognized the importance of reproduction to the maintenance of seahorses in the wild (and therefore of their source of income), and expressed concern over population declines; fishers associated the presence of a ventral pouch with reproduction in seahorses (regardless of them knowing which sex bears the pouch), and this may facilitate the construction of collaborative management options designed to eliminate captures of brooding specimens; fishers recognized microhabitats of importance to the maintenance of seahorse wild populations; fishers who kept seahorses in captivity tended to recognize the condtions as poor, and as being a cause of seahorse mortality.     

Pathogenic LMNA variants disrupt cardiac lamina-chromatin interactions and de-repress alternative fate genes

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Distribution of metal ions in the subcellular fractions of several rat brain areas.

The levels of Cu, Fe, Zn, Mg and Ca in the synaptosomal myelin and mitochondrial fractions of the rat brain were determined quantitatively by means of the atomic absorption spectroscopic method. In the whole brain the concentrations of the metals were present in the three different fractions in the following range; Cu, 0.46-1.76; Fe, 0.24-3.51; Zn, 0.12-0.93; Mg, 1.08-1.41 and Ca, 1.28-3.56 μg/mg tissue protein. Analyses of the subcellular organelles prepared from different areas of the brain indicated that the concentrations of Cu and Zn were relatively larger in the hypothalamus and lower in cerebellum in comparison with other areas. On treatment of the rats with the metal chelating agents i.e., EDA, EDDHA and HBED intracisternally, it was found that the distribution of the subcellular metals was markedly affected.