Unlike PAHs from Exxon Valdez crude oil, PAHs from Gulf of Alaska coals are not readily bioavailable.

In the wake of the 1989 Exxon Valdez oil spill, spatially and temporally spill-correlated biological effects consistent with polycyclic aromatic hydrocarbon (PAH) exposure were observed. Some works have proposed that confounding sources from local source rocks, prominently coals, are the provenance of the PAHs. Representative coal deposits along the southeast Alaskan coast (Kulthieth Formation) were sampled and fully characterized chemically and geologically. The coals have variable but high total organic carbon content technically classifying as coals and coaly shale, and highly varying PAH contents. Even for coals with high PAH content (approximately 4000 ppm total PAHs), a PAH-sensitive bacterial biosensor demonstrates nondetectable bioavailability as quantified, based on naphthalene as a test calibrant. These results are consistent with studies indicating that materials such as coals strongly diminish the bioavailability of hydrophobic organic compounds and support previous work suggesting that hydrocarbons associated with the regional background in northern Gulf of Alaska marine sediments are not appreciably bioavailable.

Organic geochemistry of Jurassic-Cretaceous source rocks and oil seeps from the profile across the Adriatic-Dinaric carbonate platform

Organic geochemical and stable isotope investigations were performed to provide an insight into the depositional environments, origin and maturity of the organic matter in Jurassic and Cretaceous formations of the External Dinarides. A correlation is made among various parameters acquired from Rock-Eval, gas chromatography-mass spectrometry data and isotope analysis of carbonates and kerogen. Three groups of samples were analysed. The first group includes source rocks derived from Lower Jurassic limestone and Upper Jurassic ``Leme'' beds, the second from Upper Cretaceous carbonates, while the third group comprises oil seeps genetically connected with Upper Cretaceous source rocks. The carbon and oxygen isotopic ratios of all the carbonates display marine isotopic composition. Rock-Eval data and maturity parameter values derived from biomarkers define the organic matter of the Upper Cretaceous carbonates as Type I-S and Type II-S kerogen at the low stage of maturity up to entering the oil-generating window. Lower and Upper Jurassic source rocks contain early mature Type III mixed with Type IV organic matter. All Jurassic and Cretaceous potential source rock extracts show similarity in triterpane and sterane distribution. The hopane and sterane distribution pattern of the studied oil seeps correspond to those from Cretaceous source rocks. The difference between Cretaceous oil seeps and potential source rock extracts was found in the intensity and distribution of n-alkanes, as well as in the abundance of asphaltenes which is connected to their biodegradation stage. In the Jurassic and Cretaceous potential source rock samples a mixture of aromatic hydrocarbons with their alkyl derivatives were indicated, whereas in the oil seep samples extracts only asphaltenes were observed.

Fish oil supplementation does not alter energy efficiency in healthy males

BACKGROUND AND AIMS: Fish oil (FO) supplementation prevents the development of obesity and insulin resistance, and upregulate the expression of UCP3 in skeletal muscle in rodents. This may represent indirect evidence that FO promotes fat oxidation and/or alter energy efficiency. The aim of this study was to evaluate whether such effects can be observed in humans. The metabolic effects of FO were assessed during exercise in order to obtain a direct measurement of energy efficiency. METHODS: Eight healthy male volunteers were studied with and without supplementation with 7.2 g/day FO (including 1.1 g/day eicosopentaenoic acid and 0.7 g/day decosahexaenoic acid) during 14 days. Their VO(2 max) was measured on cycle ergometer. Thereafter, energy metabolism (substrate oxidation, energy expenditure and energy efficiency) was assessed during a 30 min cycling exercise at 50% VO(2 max) performed 2 h 30 after a standardized, high carbohydrate breakfast. RESULTS: VO(2 max) was 38.6+/-2.2 after FO and 38.4+/-2.0 (mL x kg(-1) x min(-1)) in control conditions (NS). Basal plasma glucose, insulin and NEFA concentrations, and energy metabolism were similar with FO and in controls. During exercise, the increases in plasma NEFA concentrations, energy expenditure, glucose and lipid oxidation, and the decreases in glycaemia and insulinemia were not altered by FO intake. Energy efficiency was 22.4+/-0.6% after FO vs 21.8+/-0.7% in controls. In order to ascertain that the absence of effects of FO was not due to consumption of a carbohydrate meal immediately before exercise, 4 of the 8 subjects were re-studied in fasting conditions, FO also failed to alter energy efficiency in this subset of studies. CONCLUSION: FO supplementation did not significantly alter energy metabolism and energy efficiency during exercise in healthy humans.

Combining hypoxic methods for peak performance.

New methods and devices for pursuing performance enhancement through altitude training were developed in Scandinavia and the USA in the early 1990s. At present, several forms of hypoxic training and/or altitude exposure exist: traditional 'live high-train high' (LHTH), contemporary 'live high-train low' (LHTL), intermittent hypoxic exposure during rest (IHE) and intermittent hypoxic exposure during continuous session (IHT). Although substantial differences exist between these methods of hypoxic training and/or exposure, all have the same goal: to induce an improvement in athletic performance at sea level. They are also used for preparation for competition at altitude and/or for the acclimatization of mountaineers. The underlying mechanisms behind the effects of hypoxic training are widely debated. Although the popular view is that altitude training may lead to an increase in haematological capacity, this may not be the main, or the only, factor involved in the improvement of performance. Other central (such as ventilatory, haemodynamic or neural adaptation) or peripheral (such as muscle buffering capacity or economy) factors play an important role. LHTL was shown to be an efficient method. The optimal altitude for living high has been defined as being 2200-2500 m to provide an optimal erythropoietic effect and up to 3100 m for non-haematological parameters. The optimal duration at altitude appears to be 4 weeks for inducing accelerated erythropoiesis whereas <3 weeks (i.e. 18 days) are long enough for beneficial changes in economy, muscle buffering capacity, the hypoxic ventilatory response or Na(+)/K(+)-ATPase activity. One critical point is the daily dose of altitude. A natural altitude of 2500 m for 20-22 h/day (in fact, travelling down to the valley only for training) appears sufficient to increase erythropoiesis and improve sea-level performance. 'Longer is better' as regards haematological changes since additional benefits have been shown as hypoxic exposure increases beyond 16 h/day. The minimum daily dose for stimulating erythropoiesis seems to be 12 h/day. For non-haematological changes, the implementation of a much shorter duration of exposure seems possible. Athletes could take advantage of IHT, which seems more beneficial than IHE in performance enhancement. The intensity of hypoxic exercise might play a role on adaptations at the molecular level in skeletal muscle tissue. There is clear evidence that intense exercise at high altitude stimulates to a greater extent muscle adaptations for both aerobic and anaerobic exercises and limits the decrease in power. So although IHT induces no increase in VO(2max) due to the low 'altitude dose', improvement in athletic performance is likely to happen with high-intensity exercise (i.e. above the ventilatory threshold) due to an increase in mitochondrial efficiency and pH/lactate regulation. We propose a new combination of hypoxic method (which we suggest naming Living High-Training Low and High, interspersed; LHTLHi) combining LHTL (five nights at 3000 m and two nights at sea level) with training at sea level except for a few (2.3 per week) IHT sessions of supra-threshold training. This review also provides a rationale on how to combine the different hypoxic methods and suggests advances in both their implementation and their periodization during the yearly training programme of athletes competing in endurance, glycolytic or intermittent sports.

Effect of n-3 fatty acids on markers of brain injury and incidence of sepsis-associated delirium in septic patients.

BACKGROUND: Data regarding immunomodulatory effects of parenteral n-3 fatty acids in sepsis are conflicting. In this study, the effect of administration of parenteral n-3 fatty acids on markers of brain injury, incidence of sepsis-associated delirium, and inflammatory mediators in septic patients was investigated. METHODS: Fifty patients with sepsis were randomized to receive either 2 ml/kg/day of a lipid emulsion containing highly refined fish oil (equivalent to n-3 fatty acids 0.12 mg/kg/day) during 7 days after admission to the intensive care unit or standard treatment. Markers of brain injury and inflammatory mediators were measured on days 1, 2, 3 and 7. Assessment for sepsis-associated delirium was performed daily. The primary outcome was the difference in S-100β from baseline to peak level between both the intervention and the control group, compared by t-test. Changes of all markers over time were explored in both groups, fitting a generalized estimating equations model. RESULTS: Mean difference in change of S-100β from baseline to peak level was 0.34 (95% CI: -0.18-0.85) between the intervention and control group, respectively (P = 0.19). We found no difference in plasma levels of S-100β, neuron-specific enolase, interleukin (IL)-6, IL-8, IL-10, and C-reactive protein between groups over time. Incidence of sepsis-associated delirium was 75% in the intervention and 71% in the control groups (risk difference 4%, 95% CI -24-31%, P = 0.796). CONCLUSION: Administration of n-3 fatty acids did not affect markers of brain injury, incidence of sepsis-associated delirium, and inflammatory mediators in septic patients.

Generalist hydrocarbon-degrading bacterial communities in the oil-polluted water column of the North Sea.

The aim of this work was to determine the effect of light crude oil on bacterial communities during an experimental oil spill in the North Sea and in mesocosms (simulating a heavy, enclosed oil spill), and to isolate and characterize hydrocarbon-degrading bacteria from the water column. No oil-induced changes in bacterial community (3 m below the sea surface) were observed 32 h after the experimental spill at sea. In contrast, there was a decrease in the dominant SAR11 phylotype and an increase in Pseudoalteromonas spp. in the oiled mesocosms (investigated by 16S rRNA gene analysis using denaturing gradient gel electrophoresis), as a consequence of the longer incubation, closer proximity of the samples to oil, and the lack of replenishment with seawater. A total of 216 strains were isolated from hydrocarbon enrichment cultures, predominantly belonging to the genus Pseudoaltero monas; most strains grew on PAHs, branched and straight-chain alkanes, as well as many other carbon sources. No obligate hydrocarbonoclastic bacteria were isolated or detected, highlighting the potential importance of cosmopolitan marine generalists like Pseudoalteromonas spp. in degrading hydrocarbons in the water column beneath an oil slick, and revealing the susceptibility to oil pollution of SAR11, the most abundant bacterial clade in the surface ocean.

The TRAF-interacting protein (TRAIP) is a novel E2F target with peak expression in mitosis.

The TRAF-interacting protein (TRAIP) is an E3 ubiquitin ligase required for cell proliferation. TRAIP mRNA is downregulated in human keratinocytes after inhibition of the PI3K/AKT/mTOR signaling. Since E2F transcription factors are downstream of PI3K/AKT/mTOR we investigated whether they regulate TRAIP expression. E2F1 expression significantly increased the TRAIP mRNA level in HeLa cells. Reporter assays with the 1400bp 5'-upstream promoter in HeLa cells and human keratinocytes showed that E2F1-, E2F2- and E2F4-induced upregulation of TRAIP expression is mediated by 168bp upstream of the translation start site. Mutating the E2F binding site within this fragment reduced the E2F1- and E2F2-dependent promoter activities and protein-DNA complex formation in gel shift assays. Abundance of TRAIP mRNA and protein was regulated by the cell cycle with a peak in G2/M. Expression of GFP and TRAIP-GFP demonstrated that TRAIP-GFP protein has a lower steady-state concentration than GFP despite similar mRNA levels. Cycloheximide inhibition experiments indicated that the TRAIP protein has a half-life of around four hours. Therefore, the combination of cell cycle-dependent transcription of the TRAIP gene by E2F and rapid protein degradation leads to cell cycle-dependent expression with a maximum in G2/M. These findings suggest that TRAIP has important functions in mitosis and tumorigenesis.

Immediate ecotoxicological effects of short-lived oil spills on marine biota.

Marine environments are frequently exposed to oil spills as a result of transportation, oil drilling or fuel usage. Whereas large oil spills and their effects have been widely documented, more common and recurrent small spills typically escape attention. To fill this important gap in the assessment of oil-spill effects, we performed two independent supervised full sea releases of 5 m(3) of crude oil, complemented by on-board mesocosm studies and sampling of accidentally encountered slicks. Using rapid on-board biological assays, we detect high bioavailability and toxicity of dissolved and dispersed oil within 24 h after the spills, occurring fairly deep (8 m) below the slicks. Selective decline of marine plankton is observed, equally relevant for early stages of larger spills. Our results demonstrate that, contrary to common thinking, even small spills have immediate adverse biological effects and their recurrent nature is likely to affect marine ecosystem functioning.