Rates of surficial rock creep on hillslopes in Western colorado.

The average rate of downslope movement of rock fragments on shale hillslopes is directly proportional to the sine of the slope angle or that component of the gravitational force which acts parallel to the hillslope. The rates of surficial rock creep range from a few millimeters per year on a 3degree slope to almost 70 millimeters per year on a 40-degree slope, but these rates vary with natural variations in soil characteristics and microclimate, as well as with accidental disturbances.

Meander wavelength of alluvial rivers.

Data on river channel and sediment characteristics were collected at 36 cross sections of stable alluvial river channels in Australia and western United States. These data demonstrate that the meander wavelength of a river is dependent not only on water discharge, but also on the type of sediment load moved through the channel. The meander wavelength of rivers that are transporting a high proportion of their total sediment load as both sand and gravel will be greater than the meander wavelengths of channels of similar discharge which are transporting mainly fine sediment loads.

Alluvial-river response to neotectonic deformation in louisiana and Mississippi.

Repeat geodetic surveys show uplift of the Monroe and Wiggins anticlines in Louisiana and Mississippi. There are deformed Quaternary terraces, which indicate long-term deformation in the valleys of the alluvial rivers that cross these structures, and there are floodplain and channel convexities that provide evidence of modern deformation. In addition, the channels show significant variations of morphology (sinuosity, gradient, and depth) and behavior appropriate to reaches of increased and decreased valley slope. These alluvial rivers are adjusting to modern deformation and their adjustment confirms two geodetic leveling anomalies.

Comprehensive metabolomics to evaluate the impact of industrial processing on the phytochemical composition of vegetable purees.

The effects of conventional industrial processing steps on global phytochemical composition of broccoli, tomato and carrot purees were investigated by using a range of complementary targeted and untargeted metabolomics approaches including LC-PDA for vitamins, (1)H NMR for polar metabolites, accurate mass LC-QTOF MS for semi-polar metabolites, LC-MRM for oxylipins, and headspace GC-MS for volatile compounds. An initial exploratory experiment indicated that the order of blending and thermal treatments had the highest impact on the phytochemicals in the purees. This blending-heating order effect was investigated in more depth by performing alternate blending-heating sequences in triplicate on the same batches of broccoli, tomato and carrot. For each vegetable and particularly in broccoli, a large proportion of the metabolites detected in the purees was significantly influenced by the blending-heating order, amongst which were potential health-related phytochemicals and flavour compounds like vitamins C and E, carotenoids, flavonoids, glucosinolates and oxylipins. Our metabolomics data indicates that during processing the activity of a series of endogenous plant enzymes, such as lipoxygenases, peroxidases and glycosidases, including myrosinase in broccoli, is key to the final metabolite composition and related quality of the purees.

Photocrosslinking in ruthenium-labelled duplex oligonucleotides.

The formation of a photoadduct between a [Ru(1,4,5,8-tetraazaphenanthrene)(2)4,7-diphenylphenanthroline](2+) complex chemically attached to a synthetic oligonucleotide, and a guanine moiety in a complementary targeted single-stranded DNA molecule was studied for ten 17-mer duplexes by denaturing gel electrophoresis. This photoadduct formation leads to photocrosslinking of the two strands. The percentage quenching of luminescence of the complex by electron transfer was compared to the resulting yield of photocrosslinked product. This yield does not only depend on the ionisation potential of the guanine bases, which are electron donors, but also on other factors, such as the position of the guanine bases as compared to the site of attachment of the complex. The photocrosslinking yield is higher when the guanine moieties are towards the 3' end on the complementary strand as compared to the tethering site. Computer modelling results are in agreement with this preference for the 3' side for the photoreaction. Interestingly, the photocrosslink is not alkali labile. Moreover, a type III exonuclease enzyme is blocked at the position of photocrosslinking.

Luminescence quenching of Ru-labeled oligonucleotides by targeted complementary strands.

The yield of hole injection into guanines of different oligonucleotide duplexes by a photooxidizing tethered Ru(II) complex is examined by measuring the luminescence quenching of the excited complex. This yield is investigated as a function of the anchoring site of the complex (on a thymine nucleobase in the middle of the sequence or on the 5' terminal phosphate) and the number and position of the guanine bases as compared with the site of attachment of the Ru(II) compound. In contrast to other studies, the tethered complex, [Ru(tap)(2)(dip)](2+), is a non-intercalating compound and has been shown previously to produce an irreversible photocrosslinking between the two strands as the ultimate step of hole injection. The study of luminescence quenching of the anchored complex by emission intensity and lifetime measurements for the different duplexes indicates that a direct contact between the complex and the guanine nucleobase is needed for the electron transfer to take place. Moreover, for none of the sequences a clear contribution of a static quenching is evidenced independently of the two types of attachment of the [Ru(tap)(2)(dip)](2+) complex to the oligonucleotide. A comparison of the fastest hole-injection process by electron transfer to the excited anchored [Ru(tap)(2)(dip)](2+), with the rate of the photo-electron transfer between the same complex free in solution and guanosine-5'-monophosphate, indicates that the hole injection by the anchored complex is slower by a factor of 10 at least. A bad overlap between donor and acceptor orbitals is probably the cause of this slow rate, which could be attributed to some steric hindrance induced by the complex linker.