Organic sulfur compounds resulting from the interaction of iron sulfide,hydrogen sulfide and carbon dioxide in an anaerobic aqueous environment

The reaction of iron sulfide (FeS) with H₂S in water, in presence of CO₂ under anaerobic conditions was found to yield H₂ and a variety of organic sulfur compounds, mainly thiols and small amounts of CS₂ and dimethyldisulfide. The same compounds were produced when H₂S was replaced by HCl, in the H₂S-generating system FeS/HCl/CO₂. The identification of the products was confirmed by GC-MS analyses and the incorporation of H₂ in the organic sulfur compounds was demonstrated by experiments in which all hydrogen compounds were replaced by deuterium compounds. Generation of H₂ and the synthesis of thiols were both dependent upon the relative abundance of FeS and HCl or H₂S, i.e. the FeS/HCl- or FeS/H₂S-proportions. Whether thiols or CS₂ were formed as the main products depended also on the FeS/HCl-ratio: All conditions which create a H₂ deficiency were found to initiate a proportional increase in the amount of CS₂. The quantities of H₂ and thiols generated depended on temperature: the production of H₂ was significantly accelerated from 50°C onward and thiol synthesis above 75°C. The yield of thiols increased with the amount of FeS and HCl (H₂S), given a certain FeS/HCl-ratio and a surplus of CO₂. A deficiency of CO₂ results in lower thiol systhesis. The end product, pyrite (FeS₂), was found to appear as a silvery granular layer floating on the aqueous surface. The identity of the thiols was confirmed by mass spectrometry, and the reduction of CO₂ demonstrated by the determination of deuterium incorporation with DCl and D₂O. The described reactions can principally proceed under the conditions comparable to those obtaining around submarine hydrothermal vents, or the global situation about 4 billion years ago, before the dawn of life, and could replace the need for a reducing atmosphere on the primitive earth.     

Cis-dichloro-diammine platinum (II) as stain for electron microscopic preparations.

Cis-dichloro-diammine platinum (II) provides a strong contrast to electron microscopic preparations by reacting with nucleic acids and proteins. This staining technique is easy and applicable to ultrathin sections embedded in Epon; various staining conditions have been tested.     

Variability of the molecular size of extracellular amylase produced by intact cells and protoplasts of Bacillus caldolyticus

One of the typical properties of the extracellular amylase produced by Bacillus caldolyticus is the tendency to disintegrate into subunits with a molecular weight (MW) of less than 10,000, when the enzyme is subjected to ultrafiltration. Disintegration is due to a loss of Ca-ions, leading to nonactive subunits. Activity can be fully restroed by addition of Ca-ions. Reactivation occurs also spontaneously if the low MW fraction is stored in glassware. Comparative ultrafiltration experiments with the subunit fraction with or without a supply of Ca revealed that in presence of this divalent cation the subunits reaggregated to the active enzyme. The different distribution patterns obtained in absence or presence of Ca showed that reactivation is directly linked to the formation of a high MW form of the protein. Substitution of Ca by other divalent cations also led to reaggregation. These aggregates are, however, inactive. The enzyme was found to be formed intracellularly in its low MW form. Experiments with protoplasts revealed that these are capable to produce and release the amylase. When the production of the enzyme by protoplasts declined, full restoration could be achieved by a recovery treatment. Normally, the enzyme released by the protoplasts consisted of equal portions of the high, medium, and low MW form of the amylase. If the cells were, however, depleted as a result of continued incubations, the extruded enzyme consisted increasingly of the low MW form, which could finally represent more than 80%. This trend could be completely reversed by the supply of carbon and nitrogen sources during the recovery treatment, whereafter the enzyme consisted again of the intially observed equal amounts of the three MW forms. Vesicles prepared from the protoplasts were also found to release amylase, but on a lower level, and only for a very limited time, with no possibility to regain activity by a recovery treatment. Subunit formation was also observed during column chromatography, which could be counteracted by a sufficient supply with Ca-ions.     

The Importance of a Social Science Research Agenda in the Management of Protected Natural Areas,with Selected Examples

The advent of the modern protected area movement began in 1872 with the creation of Yellowstone National Park in the United States. For a century thereafter, as more nations began to set up protected area systems, the movement was largely western-dominated and adhered to ‘fences and fines’ forms of conservation. As many more developing nations gained independence in the latter half of the twentieth century, it was increasingly recognized that strict forms of conservation based on western ideals of nature could not be sustained in the long term. Specifically, many rural people in developing countries are dependent on local natural resources, and the conservation rules put into place in many protected areas frequently forbade all extraction and in many cases all entry except for tourism or research. This created a climate of increasing park-people conflicts that in many cases compromised conservation goals and led to a refocus in protected areas management and research in the social sciences worldwide. Here I describe survey and non-survey based protocols developed to study the effectiveness of protected areas in the societal realm. Policy gap analyses, rapid rural appraisals, key informant and focus group surveys and structured and semi-structured social surveys are described. Such studies can allow managers to plan for interventions where needed and can aid in designing appropriate local development projects in an effort to ameliorate park-people conflicts. I finish with a preliminary social research protocol, tested in May, 2009, for Yachang Orchid Reserve, Guangxi Province, the People’s Republic of China.