Abstract-Anew route for the formation of gammacerane from tetmhymanol is proposed; in addition to dehydration and hydrogenation, sulphurisation and early C-S cleavage are shown to be important in the pathway of formation, especially in marine sediments. Evidence is twofold. First, relatively large amounts of the gammacerane skeleton are sequestered in S-rich macromolecular aggregates formed by natural sulphurisation of functionalised lipids.

To study the putative association of dopamine agonists with sleep attacks in patients with Parkinson's disease (PD) and their relation to daytime sleepiness, we performed a survey of 2,952 PD patients in two German counties. In 177 patients, sudden, unexpected, and irresistible sleep episodes while engaged in some activity were identified in a structured telephone interview. Ninety-one of these patients denied the occurrence of appropriate warning signs. A total of 133 patients (75%) had an Epworth Sleepiness Scale (ESS) score >10; 65 (37%) >15. Thirty-one patients (18%) had an ESS score < or =10 and yet experienced sleep attacks without warning signs. Thus, although a significant proportion of patients at risk for sleep attacks might be identified using the ESS, roughly 1% of the PD patient population seems to be at risk for sleep attacks without appropriate warning signs and without accompanying daytime sleepiness. Sleep attacks occurred with all dopamine agonists marketed in Germany (alpha-dihydroergocryptine, bromocriptine, cabergoline, lisuride, pergolide, pramipexole, ropinirole), and no significant difference between ergot and nonergot drugs was evident. Levodopa (L-dopa) monotherapy carried the lowest risk for sleep attacks (2.9%; 95% confidence interval [CI], 1.7-4.0%) followed by dopamine agonist monotherapy (5.3%; 95% CI, 1.5-9.2%) and combination of L-dopa and a dopamine agonist (7.3%; 95% CI, 6.1-8.5%). Neither selegeline nor amantadine or entacapone appeared to influence the occurrence of sleep attacks. A high ESS score, intake of dopamine agonists, and duration of PD were the main influencing factors for the occurrence of sleep attacks. The odds ratio for dopamine agonist therapy was 2.9 compared to 1.9 with L-dopa therapy and 1.05 for a 1-year-longer disease duration.

This study addresses key processes in high-energy beach systems using an interdisciplinary approach. We assess spatial variations in subsurface pore water residence times, salinity, organic matter (OM) availability, and redox conditions and their effects on nutrient cycles as well as on microbial community patterns and microphytobenthos growth. At the study site on Spiekeroog Island, southern North Sea, beach hydrology is characterized by the classical zonation with an upper saline plume (USP), a saltwater wedge, and a freshwater discharge tube in between. Sediment and pore water samples were taken along a cross-shore transect from the dunes to the low-water line reaching sediment depths down to 5 m below sediment surface. Spatial variations in pore water residence time, salinity, and organic matter availability lead to steep redox and nutrient gradients. Vertical and horizontal differences in the microbial community indicate the influence of these gradients and salinity on the community structure. shoreline. We propose that this nutrient efflux triggers growth of microphytobenthos on sediment surfaces of the discharge zone. A first comparison of nutrient discharge rates of the beach site with a nearby sandy backbarrier tidal flat margin indicates that the beach system might be of less importance in supplying recycled nutrients to nearshore waters than the backbarrier tidal flat area.

Abstract--A wide range of novel diagenetic and catagenetic products of the diaromatic carotenoid isorenieratene, a pigment of the photosynthetic green sulphur bacteria Chlorobiaceae, has been identified in a number of sedimentary rocks ranging from Ordovician to Miocene. Compound identification is based on NMR, mass spectrometry, the presence of atropisomers, and stable carbon isotopes. Atropisomers contain an axially chiral centre which, in combination with other chiral centres, results in two or more diastereomers that can be separated on a normal GC column. Chlorobiaceae use the reverse TCA cycle to fix carbon, so that their biomass is enriched in 13C. High ~3C contents of isorenieratene derivatives therefore support their inferred origins.Isorenieratene derivatives include C4o, C33, and C32, diaryl isoprenoids and short-chain aryl isoprenoids with additional aromatic and/or S-containing rings. C33 and C32 compounds are diagenetic products of C33 and C32 "carotenoids" formed from isorenieratene during early diagenesis through expulsion of toluene and m-xylene, respectively. Cyclisation of the polyene acyclic isoprenoid chain can proceed via an intramolecular Diels-Alder reaction, followed by aromatisation of the newly formed ring. Sulphurisation is also an important process during early diagenesis, competing with expulsion and cyclisation. Sulphur-bound isorenieratane is released during progressive diagenesis, due to cleavage of relatively weak S-S and C-S bonds. Cleavage of C-C bonds during aromatisation of newly formed rings and during catagenesis yields short-chain compounds. The inherent presence of a conjugated double bond system in carotenoids implies that similar diagenetic and catagenetic reactions can occur with all carotenoids.Chlorobiaceae live at or below the oxic/anoxic boundary layer and require both light and H2S. The presence of isorenieratene or its diagenetic and catagenetic products in ancient sedimentary rocks and crude oils is therefore an excellent indication for photic zone anoxia in the depositional environment. Diagenetic and catagenetic products of isorenieratene are expected to find applications in reconstruction of palaeoenvironments and in oil-oil and oil-source rock correlation studies. Their presence in several petroleum source rocks suggests that anoxia is an important environmental parameter for the preservation of organic matter.

No abstract

We studied the microbial diversity of benthic cyanobacterial mats inhabiting a heavily polluted site in a coastal stream (Wadi Gaza) and monitored the microbial community response induced by exposure to and degradation of four model petroleum compounds in the laboratory. Phormidium-and Oscillatoria-like cyanobacterial morphotypes were dominant in the field. Bacteria belonging to different groups, mainly the Cytophaga-Flavobacterium-Bacteriodes group, the ␥ and ␤ subclasses of the class Proteobacteria, and the green nonsulfur bacteria, were also detected. In slurry experiments, these communities efficiently degraded phenanthrene and dibenzothiophene completely in 7 days both in the light and in the dark. n-Octadecane and pristane were degraded to 25 and 34% of their original levels, respectively, within 7 days, but there was no further degradation until 40 days. Both cyanobacterial and bacterial communities exhibited noticeable changes concomitant with degradation of the compounds. The populations enriched by exposure to petroleum compounds included a cyanobacterium affiliated phylogenetically with Halomicronema. Bacteria enriched both in the light and in the dark, but not bacteria enriched in any of the controls, belonged to the newly described Holophaga-Geothrix-Acidobacterium phylum. In addition, another bacterial population, found to be a member of green nonsulfur bacteria, was detected only in the bacteria treated in the light. All or some of the populations may play a significant role in metabolizing the petroleum compounds. We concluded that the microbial mats from Wadi Gaza are rich in microorganisms with high biodegradative potential.

The subsurface of a tidal-flat sediment was analyzed down to 360 cm in depth by molecular and geochemical methods. A community structure analysis of all three domains of life was performed using domain-specific PCR followed by denaturing gradient gel electrophoresis analysis and sequencing of characteristic bands. The sediment column comprised horizons easily distinguishable by lithology that were deposited in intertidal and salt marsh environments. The pore water profile was characterized by a subsurface sulfate peak at a depth of about 250 cm. Methane and sulfate profiles were opposed, showing increased methane concentrations in the sulfate-free layers. The availability of organic carbon appeared to have the most pronounced effect on the bacterial community composition in deeper sediment layers. In general, the bacterial community was dominated by fermenters and syntrophic bacteria. The depth distribution of methanogenic archaea correlated with the sulfate profile and could be explained by electron donor competition with sulfate-reducing bacteria. Sequences affiliated with the typically hydrogenotrophic Methanomicrobiales were present in sulfate-free layers. Archaea belonging to the Methanosarcinales that utilize noncompetitive substrates were found along the entire anoxic-sediment column. Primers targeting the eukaryotic 18S rRNA gene revealed the presence of a subset of archaeal sequences in the deeper part of the sediment cores. The phylogenetic distance to other archaeal sequences indicates that these organisms represent a new phylogenetic group, proposed as "tidal-flat cluster 1." Eukarya were still detectable at 360 cm, even though their diversity decreased with depth. Most of the eukaryotic sequences were distantly related to those of grazers and deposit feeders.It has been estimated, that marine subsurface habitats harbor the majority of the global prokaryotic biomass (55). Despite the inhospitality of subsurface sites, remarkably diverse microbial communities were found within the deep biosphere tens to hundreds of meters below the seafloor (15, 31). Microbiological investigations on marine subsurface communities mainly focused on the deep biosphere in open-ocean and continental-margin sediments (8, 34). So far, little attention has been paid to the subsurface of coastal sediments (49), but the number of publications is increasing (23,29,56).Tidal flats are characterized by high primary production rates and consequently intense remineralization in the sediment (10, 38, 39). Furthermore, they exhibit high sedimentation rates and, in contrast to open-ocean sites (8, 35), steep chemical gradients, with oxygen generally being depleted within a few millimeters below the sediment surface (2). Nevertheless, tidal-flat sediments show a strong patchiness as oxic microniches can be found down to a depth of 20 cm along the burrows of the zoobenthos (40). In layers beneath, however, microbial processes are strictly anaerobic and seem to be governed by the sequence of electron acceptors along the redox series, wit...

A double-blind, placebo-controlled study with a subsequent open-label phase was conducted in 354 patients with Parkinson's disease (PD) and motor fluctuations under individually adjusted therapy with levodopa. During the double-blind phase 174 patients received pramipexole and 180 placebo. In agreement with previous studies, pramipexole treatment improved UPDRS sum scores of parts II and III by 30% and off times by approximately 2.5 hours per day. Differences between the treatment groups became significant at a daily dose of 0.75 mg of pramipexole dihydrochloride. We, furthermore, performed post hoc analyses with respect to resting tremor and depression. Patients with pronounced resting tremor derived a clear benefit from pramipexole treatment compared with placebo. In addition, pramipexole significantly improved the subitems motivation/initiative and depression in a subpopulation with increased Unified Parkinson's Disease Rating Scale I scores at the time of inclusion. There were 262 patients who were subsequently enrolled into the open-label study featuring a maximum duration of up to 57 months. Statistical analysis revealed good long-term efficacy and tolerability of pramipexole. Overall, only a low prevalence of somnolence was found. In summary, this study provides additional level I evidence of the usefulness of pramipexole, suggests a particular tremorlytic and a possible antidepressant action of this compound, and addresses for the first time its efficacy and safety during long-term administration in advanced PD.