Occurrence and distribution of novel botryococcene hydrocarbons in freshwater wetlands of the Florida Everglades

A high abundance of isoprenoid hydrocarbons, the botryococcenes, with carbon numbers from 32 to 34 were detected in the Florida Everglades freshwater wetlands. These compounds were present in varying amounts up to 106microg/gdw in periphyton, 278microg/gdw in floc, and 46microg/gdw in soils. Their structures were determined based on comparison to standards, interpretation of their mass spectra and those of their hydrogenation products, and comparison of Kovats indexes to those reported in the literature. A total of 26 cyclic and acyclic botryococcenes with 8 skeletons were identified, including those with fewer degrees of unsaturation, which are proposed as early diagenetic derivatives from the natural products. This is the first report that botryococcenes occur in the Everglades freshwater wetlands. Their potential biogenetic sources from green algae and cyanobacteria were examined, but neither contained botryococcenes. Thus, the source implication of botryococcenes in this ecosystem needs further study.     

Comparison of Extraction Methods for the Detection of Tick-Borne Encephalitis Virus RNA in Goat Raw Milk and Cream Cheese

Food and Environmental Virology - Infection with the tick-borne encephalitis virus (TBEV) can cause meningitis, meningoencephalitis and myelitis in humans. TBEV is an enveloped RNA virus of the...     

Effects of new technologies with special regard for the implementation process per se

The aim of this study was to investigate the effects of the implementation process to new technologies [e.g. drawing board/computer-aided design (CAD), microfiche/electronic data processing] on the employees concerned. Since the emphasis of the study lay in the intrinsic relationship of the implementation process with stress reactions, the parameters were measured at the place of work in a longitudinal design. Employees (n = 279) in seven companies (work fields: CAD, clerical work, telephone information desk) were tested three times — two months prior to, during, and 12 months after implementation. Aspects of strain and satisfaction were taken into account at each measurement phase. A special test-instrument was designed to describe the ’style of implementation‘ (manner in which implementation took place) particular to each company. The level of strain was found to increase during the implementation process. The amount of this increase was found to correlate with the company's style of implementation as well as with the type of the individual's work activity. The highest levels were found among those employees little included in the implementation process and those whose work is described as monotonous.     

The major components of particles emitted during recycling of waste printed circuit boards in a typical e-waste workshop of South China

Electronic waste from across the world is dismantled and disposed of in China. The low-tech recycling methods have caused severe air pollution. Air particle samples from a typical workshop of South China engaged in recycling waste printed circuit boards have been analyzed with respect to chemical constituents. This is the first report on the chemical composition of particulate matter (PM) emitted in an e-waste recycling workshop of South China. The results show that the composition of PM from this recycling process was totally different from other emission sources. Organic matter comprised 46.7–51.6% of the PM. The major organic constituents were organophosphates consisting mainly of triphenyl phosphate (TPP) and its methyl substituted compounds, methyl esters of hexadecanoic and octadecanoic acids, levoglucosan and bisphenol A. TPP and bisphenol A were present at 1–5 orders of magnitude higher than in other indoor and outdoor environments throughout the world, which implies that they might be used as potential markers for e-waste recycling. The elemental carbon, inorganic elements and ions had a minor contribution to the PM (<5% each). The inorganic elements were dominated by phosphorus and followed by crustal elements and metal elements Pb, Zn, Sn, and lesser Cu, Sb, Mn, Ni, Ba and Cd. The recycling of printed circuit boards was demonstrated as an important contributor of heavy metal contamination, particularly Cd, Pb and Ni, to the local environment. These findings suggest that this recycling method represents a strong source of PM associated with pollutants to the ambient atmosphere of an e-waste recycling locale.     

Mobile fission and activation products in nuclear waste disposal

When disposing nuclear waste in clay formations it is expected that the most radiotoxic elements like Pu, Np or Am move only a few centimetres to meters before they decay. Only a few radionuclides are able to reach the biosphere and contribute to their long-term exposure risks, mainly anionic species like I129, Cl36, Se79 and in some cases C14 and Tc99, whatever the scenario considered. The recent OECD/NEA cosponsored international MOFAP workshop focussed on transport and chemical behaviour of these less toxic radionuclides. New research themes have been addressed, such as how to make use of molecular level information for the understanding of the problem of migration at large distances. Diffusion studies need to face mineralogical heterogeneities over tens to hundreds of meters. Diffusion rates are very low since the clay rock pores are so small (few nm) that electrostatic repulsion limits the space available for anion diffusion (anion exclusion). The large volume of traversed rock will provide so many retention sites that despite weak retention, even certain of these “mobile” nuclides may show significant retardation. However, the question how to measure reliably very low retention parameters has been posed. An important issue is whether redox states or organic/inorganic speciation change from their initial state at the moment of release from the waste during long term contact with surfaces, hydrogen saturated environments, etc.     

Towards an experimental analysis of molecular self-organization and precellular Darwinian evolution

An experimental system is described, which opens up a novel pathway towards a molecular understanding of the origin of life. The systemic conditions for the evolution of biological macromolecules are investigated in detail.     

Abfallwirtschaft: Neue Sichtweisen und Techniken

In den letzten Jahren werden in vielen Ländern eher die Abfallkomponenten als vielmehr die Stoffmischungen betrachtet. Das gesetzliche Rahmenwerk des Stoffstrommanagement kann dazu beitragen, die Probleme auf wissenschaftlicher Grundlage zu lösen. Der Einfluss der neuen Gesetzgebung in Deutschland und Europa auf das Stoffstrommanagement sowie auf die Entwicklung neuer Techniken bei Abfallentsorgung und-recycling wird in diesem Beitrag untersucht. Neue Prinzipien für das Abfallmanagement werden vom Management der Stoffströme abgeleitet.     

Seventh International Congress of Ecology: Symposium on “Trace Metals in the Environment” Florenz, Juli 1998

Der VII. Internationale Kongre? für ?kologie ergab die M?glichkeit, auch einige Spezialisten aus der ?kologischen Spurenelementforschung in Florenz zusammenzubringen. Dabei zeigte sich deutlich, da? noch wesentliche Arbeit auf dem Weg zu einem generellen Verst?ndnis der Wirkung einzelner Elemente und ihrer Spezies vor uns liegt. Obwohl auf analytischem Sektor beachtliche Durchbrüche durch die Entwicklung leistungsf?higer Methoden bewerkstelligt wurden, bleiben noch wichtige Fragen zur essentiellen und/oder toxikologischen Wirkung einzelner Spurenelemente zu beantworten. Hieraus lassen sich aus den Beitr?gen der Teilnehmer des Symposiums folgende Forderungen ableiten: