Aquaporins of the TIP subfamily (Tonoplast Intrinsic Proteins) have been suggested to facilitate permeation of water and ammonia across the vacuolar membrane of plants, allowing the vacuole to efficiently sequester ammonium ions and counteract cytosolic fluctuations of ammonia. Here, we report the structure determined at 1.18 Å resolution from twinned crystals of Arabidopsis thaliana aquaporin ...

We carried out spectral-induced polarization (SIP) measurements on a set of dried seafloor massive sulfide samples and compared the results with those obtained same fully saturated NaCl solution. find that conductivity polarizability are generally high for both samples, i.e., exhibiting phase shifts in order 100 s mrad imaginary conductivities up to 1 S/m. Depending particular sample, polarizab...

Two resin injection studies of the lumbar extradural space were performed to elucidate its size and shape. To counteract the lack of cerebrospinal fluid pressure in the cadaver, the subarachnoid space was filled with water. In group 1, the extradural injection of resin caused an immediate increase in subarachnoid pressure. The casts produced varied in thickness, but were situated predominantly ...

We report results of EPR measurements of activated carbon fibers. Experiments made for pristine activated carbon fibers and activated carbon fibers with adsorbed molecules (CCl4, C6H5NO2, and H2O) confirmed the localized character of paramagnetic centers observed in the system. Pristine activated carbon fibers are characterized by single Lorentzian line. Broader component of EPR signal appears ...

The potassium channel from Streptomyces lividans is an integral membrane protein with sequence similarity to all known K+ channels, particularly in the pore region. X-ray analysis with data to 3.2 angstroms reveals that four identical subunits create an inverted teepee, or cone, cradling the selectivity filter of the pore in its outer end. The narrow selectivity filter is only 12 angstroms long...

Compacted clays are considered as excellent candidates for barriers to radionuclide transport in future repositories for nuclear waste due to their very low hydraulic permeability. Diffusion is the dominant transport mechanism, controlled by a nano-scale pore system. Assessment of the clays' long-term containment function requires adequate modelling of such pore systems and their evolution. Exi...

Caenorhabditis elegans strains carrying stress-reporter green fluorescent protein transgenes were used to explore patterns of response to metals. Multiple stress pathways were induced at high doses by most metals tested, including members of the heat shock, oxidative stress, metallothionein (mtl) and xenobiotic response gene families. A mathematical model (to be published separately) of the gen...

abstract by increasing the world population and more need to supply food, farmers attend to use of chemical fertilizers, organic manures and pesticides. also, applications of these agents without attention to their side effects, cause more problems to human health and environment. nitrate is one of the most important elements of organic manures, which leach through soil to surface and ground wa...

pore network modeling uses a network of pores connected by throats to model the void space of a porous medium and tries to predict its various characteristics during multiphase flow of various fluids. in most cases, a non-realistic regular lattice of pores is used to model the characteristics of a porous medium. although some methodologies for extracting geologically realistic irregular network...