Cation Transport I. Metabolic Activity of the Polyphosphoinositide Complex in Isolated Renal Cortex Tubules

Although several mechanisms have been proposed to explain the transport of hydrophylilc cations across lipoprotein barriers, the nature and identity of the carrier mechanism have not yet been elucidated. The present communication is concerned with a mechanism postulating that monoesterified phosphate on the inositol moiety of phosphatidyl inositol might provide anionic sites that function as cation carriers via a phosphorylation-dephosphorylation cycle, catalyzed in its simplest sequence by phosphatidyl inositol kinase and diphosphoinositide phosphomonoesterase activities. In this context, one might reasonably expect that turnover of monoesterified phosphate in the polyphosphoinositides of isolated renal cortex tubules would be reduced in tubules in which movement of sodium out of, and of potassium into, the tubule cells had been inhibited by ouabain. Contrary to this expectation, turnover of monoesterified phosphate, as evidenced by 32P-orthophosphate incorporation into the monoesterified phosphate of the polyphosphoinositides, was strikingly increased when such tubules from rabbits were incubated in the presence of ouabain. This increase appeared to correlate only with ouabain-inhibited extrusion of sodium from the intracellular compartment of tubule cells, and not at all with the inhibitory effects of ouabain on K+-reaccumulation

Microseismicity Induced in the Opalinus Clay by a Gallery Excavation in the Mont Terri Underground Rock Laboratory

International audienc

Seismotectonic analysis around the Mont Terri rock laboratory (Switzerland): a pilot study

For this pilot study we used recorded seismic events from the SED permanent network and data from a dedicated SNS network to improve the seismotectonic understanding of very weak seismicity in the vicinity of the Mont Terri underground laboratory. We combined field data on faults with microseismic events and modelling of stress and focal mechanisms. Eighty-six events with very low magnitudes (ML ≈ −2.0 to 2.0) recorded between July 2014 and August 2015 were located within a radius of 10 km of the underground laboratory and used for modelling. We compiled 234 fault/striation data from laboratory tunnels and regional geology, and also from seismic/borehole data on basement faults. With this database we defined seven groups of main faults in the cover and four groups in the basement. For each of these groups we computed a synthetic focal mechanism that was subsequently used to determine a synthetic P-phase waveform. The synthetic waveforms were then correlated with the microseismic events of the cover and the basement respectively. Of these, 78 events yielded satisfactorily correlation coefficients that we used for a regional seismotectonic interpretation. The synthetic focal mechanism can be linked to the main regional structural features: the NNE–SSW-oriented reactivated faults associated with the Rhine Graben development, and the NE–SW-oriented reverse faults related to the thrust development of major folds such as the Mont Terri anticline. The results for this pilot study confirm that our affirmative method can be used to augment local and regional seismotectonic interpretations with very weak-intensity earthquake data

Impact of Marine Drugs on Animal Reproductive Processes

The discovery and description of bioactive substances from natural sources has been a research topic for the last 50 years. In this respect, marine animals have been used to extract many new compounds exerting different actions. Reproduction is a complex process whose main steps are the production and maturation of gametes, their activation, the fertilisation and the beginning of development. In the literature it has been shown that many substances extracted from marine organisms may have profound influence on the reproductive behaviour, function and reproductive strategies and survival of species. However, despite the central importance of reproduction and thus the maintenance of species, there are still few studies on how reproductive mechanisms are impacted by marine bioactive drugs. At present, studies in either marine and terrestrial animals have been particularly important in identifying what specific fine reproductive mechanisms are affected by marine-derived substances. In this review we describe the main steps of the biology of reproduction and the impact of substances from marine environment and organisms on the reproductive processes

Effects of the Potent Nephrotogenic Aminonucleoside of Puromycin on Phospholipid Metabolism in Rat Kidney Cortex Subcellular Fractions

A continuing study of a chemically induced model of nephrosis raises some interesting possibilities in the understanding of membrane mechanochemistry and resultant transport abnormalitie

Experiments on thermo-hydro-mechanical behaviour of Opalinus Clay at Mont Terri rock laboratory, Switzerland

Repositories for deep geological disposal of radioactive waste rely on multi-barrier systems to isolate waste from the biosphere. A multi-barrier system typically comprises the natural geological barrier provided by the repository host rock – in our case the Opalinus Clay – and an engineered barrier system (EBS). The Swiss repository concept for spent fuel and vitrified high-level waste (HLW) consists of waste canisters, which are emplaced horizontally in the middle of an emplacement gallery and are separated from the gallery wall by granular backfill material (GBM). We describe here a selection of five in-situ experiments where characteristic hydro-mechanical (HM) and thermo-hydro-mechanical (THM) processes have been observed. The first example is a coupled HM and mine-by test where the evolution of the excavation damaged zone (EDZ) was monitored around a gallery in the Opalinus Clay (ED-B experiment). Measurements of pore-water pressures and convergences due to stress redistribution during excavation highlighted the HM behaviour. The same measurements were subsequently carried out in a heater test (HE-D) where we were able to characterise the Opalinus Clay in terms of its THM behaviour. These yielded detailed data to better understand the THM behaviours of the granular backfill and the natural host rock. For a presentation of the Swiss concept for HLW storage, we designed three demonstration experiments that were subsequently implemented in the Mont Terri rock laboratory: (1) the engineered barrier (EB) experiment, (2) the in-situ heater test on key-THM processes and parameters (HE-E) experiment, and (3) the full-scale emplacement (FE) experiment. The first demonstration experiment has been dismantled, but the last two ones are on-going

Solute transport in crystalline rocks at Äspö — I: Geological basis and model calibration

Water-conducting faults and fractures were studied in the granite-hosted A¨ spo¨ Hard Rock Laboratory (SE Sweden). On a scale of decametres and larger, steeply dipping faults dominate and contain a variety of different fault rocks (mylonites, cataclasites, fault gouges). On a smaller scale, somewhat less regular fracture patterns were found. Conceptual models of the fault and fracture geometries and of the properties of rock types adjacent to fractures were derived and used as input for the modelling of in situ dipole tracer tests that were conducted in the framework of the Tracer Retention Understanding Experiment (TRUE-1) on a scale of metres. After the identification of all relevant transport and retardation processes, blind predictions of the breakthroughs of conservative to moderately sorbing tracers were calculated and then compared with the experimental data. This paper provides the geological basis and model calibration, while the predictive and inverse modelling work is the topic of the companion paper [J. Contam. Hydrol. 61 (2003) 175]. The TRUE-1 experimental volume is highly fractured and contains the same types of fault rocks and alterations as on the decametric scale. The experimental flow field was modelled on the basis of a 2D-streamtube formalism with an underlying homogeneous and isotropic transmissivity field. Tracer transport was modelled using the dual porosity medium approach, which is linked to the flow model by the flow porosity. Given the substantial pumping rates in the extraction borehole, the transport domain has a maximum width of a few centimetres only. It is concluded that both the uncertainty with regard to the length of individual fractures and the detailed geometry of the network along the flowpath between injection and extraction boreholes are not critical because flow is largely one-dimensional, whether through a single fracture or a network. Process identification and model calibration were based on a single uranine breakthrough (test PDT3), which clearly showed that matrix diffusion had to be included in the model even over the short experimental time scales, evidenced by a characteristic shape of the trailing edge of the breakthrough curve. Using the geological information and therefore considering limited matrix diffusion into a thin fault gouge horizon resulted in a good fit to the experiment. On the other hand, fresh granite was found not to interact noticeably with the tracers over the time scales of the experiments. While fracture-filling gouge materials are very efficient in retarding tracers over short periods of time (hours–days), their volume is very small and, with time progressing, retardation will be dominated by altered wall rock and, finally, by fresh granite. In such rocks, both porosity (and therefore the effective diffusion coefficient) and sorption Kds are more than one order of magnitude smaller compared to fault gouge, thus indicating that long-term retardation is expected to occur but to be less pronounced