THE GEOLOGIC CONTEXT OF WONDERSTONE: A COMPLEX, OUTCROP-SCALED PATTERN OF IRONOXIDE CEMENT

Although siderite is a widespread early diagenetic mineral in fluvial systems, it is unstable in oxidizing environments and destroyed in permeable rocks that experience uplift and exhumation. The products of siderite oxidation, however, (mm- to cm-scale rhombs, concretions, and complex bands of iron-oxide cement) are widespread in the rock record of fluvial systems. The fluvial channels of the Shinarump Member of the Chinle Formation in southern Utah and northern Arizona, U.S.A., provide an excellent suite of examples of diagenetic features produced by Triassic and Neogene oxidation of early diagenetic siderite. These diagenetic features also provide direct evidence of the level of the water table during deposition of the Shinarump member. Large, in situ, discoidal concretions containing preserved siderite are present in Shinarump floodplain siltstones. Rip-up clasts derived from the siltstones developed iron-oxide rinds during late-stage, near-surface oxidation. These two structures show that floodplain silts contained abundant organic matter and methanic pore water. Groundwater recharging through these silts carried reducing water through underlying sand bodies and discharged into active channels. Degassing of CO2 and methanogenesis caused rhombic crystals of siderite to precipitate in channel sands during these wet intervals. Some of this siderite may have been oxidized during dry intervals when groundwater circulation reversed, but most siderite in the channel sands was preserved until the Shinarump was exhumed during the Neogene. As oxygenated near-surface water entered joints in the lithified Shinarump, colonies of iron-oxidizing microbes living in the phreatic zone occupied redox boundaries and used the rhombic crystals of siderite in the sandstone and the spherulitic siderite in transported siltstone intraclasts as their sources of energy and carbon. The ferrous iron released from dissolving siderite within the intraclasts was oxidized at the siltstone–sandstone contact, generating rinded concretions similar to those in the Cretaceous Dakota Formation. Complex banding known as wonderstone was produced in the channel sandstones from oxidation of the rhombic siderite; the pattern is a combination of Liesegang bands and microbially mediated cements. The preserved rhombs are pseudomorphs after siderite crystals that were either oxidized during Triassic dry intervals, or escaped Neogene microbial oxidation in the phreatic zone, only to be oxidized abiotically in the vadose zone. Microbes are likely oxidizing Shinarump siderite a few kilometers down dip of outcrops with exposed wonderstone. At such locations, the Shinarump is in contact with overlying watersaturated Quaternary alluvium

Species Richness Affects Grassland Yield and Yield Stability Across Seasons, Sites and Years

The benefits of biodiversity (specifically species richness) are proposed to include both greater yield and greater stability of yield in a variable environment (Sanderson et al., 2004). Experimental evidence showing yield benefits is inconsistent (White et al., 2004). There is relatively little experimental data showing the effects of species richness on yield stability. The objective of this study was to measure the yield from mixtures with up to 12 species, and to measure the variability of yield between 2 sites, between spring and summer, and in 2 successive years

The ecology and evolution of Japanese encephalitis virus

Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus mainly spread by Culex mosquitoes that currently has a geographic distribution across most of Southeast Asia and the Western Pacific. Infection with JEV can cause Japanese encephalitis (JE), a severe disease with a high mortality rate, which also results in ongoing sequalae in many survivors. The natural reservoir of JEV is ardeid wading birds, such as egrets and herons, but pigs commonly play an important role as an amplifying host during outbreaks in human populations. Other domestic animals and wildlife have been detected as hosts for JEV, but their role in the ecology and epidemiology of JEV is uncertain. Safe and effective JEV vaccines are available, but unfortunately, their use remains low in most endemic countries where they are most needed. Increased surveillance and diagnosis of JE is required as climate change and social disruption are likely to facilitate further geographical expansion of Culex vectors and JE risk areas

Non-orientable Boundary Superstring Field theory with Tachyon field

We use the BSFT method to study the unoriented open string field theory (type I). The partition function on the Mobius strip is calculated. We find that, at the one-loop level, the divergence coming from planar graph and unoriented graph cancel each other as expected.Comment: 17 pages, 2 figures, references adde

Inflation and Kahler Stabilization of the Dilaton

The problems of attempting inflationary model-building in a theory containing a dilaton are explained. In particular, I study the shape of the dilaton potential today and during inflation, based on a weakly-coupled heterotic string model where corrections to the Kahler potential are assumed to be responsible for dilaton stabilization. Although no specific model-building is attempted, if the inflationary energy density is related to the scale of gaugino condensation, then the dilaton may be stabilized close enough to today's value that there is no significant change in the GUT scale coupling. This can occur in a very wide range of models, and helps to provide some justification for the standard predictions of the spectral index. I explain how this result can ultimately be traced to the supersymmetry structure of the theory.Comment: 12 pages, submitted to PR

Bounding Anomalous Gauge-Boson Couplings

In this version we have corrected some minor errors in the tables, corrected typos, and added a reference. We have also updated our comparison with earlier workers. Figures are now included as uuencoded compressed tar files.Comment: 32 page

Progressing the science of effluent treatment using Lasersizer diffraction analysis - a pilot study

Disinfection of waste water with ultraviolet (UV) light is a common procedure in many sewage treatment plants because it is used to inactivate coliform bacteria in the effluent. The number of coliform bacteria in a given sample is used as a proxy to indicate the presence of targeted pathogenic organisms. Typically the coliform bacteria exist in a particle-associated state which results in their being shielded from the UV light (Darby et al., 1999). Such particles are documented in the size range 20 to 80 μm, and therefore measurement of the size distribution in a sample could be used to indicate the degree of shielding. UV treatment is less effective for particles larger than about 40 μm in size (Table 1). Our pilot study used the laser diffraction technique to generate particle-size distributions of samples of effluent. By quantifying the amount of bacteria-shielding particles using this technique we were able to estimate the general efficacy of the UV sterilization process. The surface weighted mean diameter statistic was taken as a numerical measure of the bacteriashielding particle size distribution

Barriers and enablers to uptake of agroecological and regenerative farming practices, and stakeholder views about ‘living labs’

This report forms the second component of a Defra-sponsored research project entitled “Evaluating the productivity, environmental sustainability and wider impacts of agroecological compared to conventional farming systems”. The first component comprised a rapid evidence review of regenerative/agroecological farming systems. This second component describes and discusses the results of a survey to explore i) farmer and stakeholder definitions of agroecological and regenerative farming, ii) the barriers to the adoption of agroecological and regenerative farming, and iii) farmer and stakeholder views towards the concept of ‘living labs’ as a way to share research and learnings about agroecological/regenerative farming (Figure 1)

Time-dependent Orbifolds and String Cosmology

In these lectures, we review the physics of time-dependent orbifolds of string theory, with particular attention to orbifolds of three-dimensional Minkowski space. We discuss the propagation of free particles in the orbifold geometries, together with their interactions. We address the issue of stability of these string vacua and the difficulties in defining a consistent perturbation theory, pointing to possible solutions. In particular, it is shown that resumming part of the perturbative expansion gives finite amplitudes. Finally we discuss the duality of some orbifold models with the physics of orientifold planes, and we describe cosmological models based on the dynamics of these orientifolds.Comment: 74 pages, 20 figures. Updated version of lectures at RTN Winter School on Strings, Supergravity and Gauge Theory - Torino, January 2003. Contains many new results. Minor correction

Model-Independent Global Constraints on New Physics

Using effective-lagrangian techniques we perform a systematic survey of the lowest-dimension effective interactions through which heavy physics might manifest itself in present experiments. We do not restrict ourselves to special classes of effective interactions (such as `oblique' corrections). We compute the effects of these operators on all currently well-measured electroweak observables, both at low energies and at the $Z$ resonance, and perform a global fit to their coefficients. Despite the fact that a great many operators arise in our survey, we find that most are quite strongly bounded by the current data. We use our survey to systematically identify those effective interactions which are {\it not} well-bounded by the data -- these could very well include large new-physics contributions. Our results may also be used to efficiently confront specific models for new physics with the data, as we illustrate with an example.Comment: plain TeX, 68 pages, 2 figures (postscript files appended), McGill-93/12, NEIPH-93-008, OCIP/C-93-6, UQAM-PHE-93/08, UdeM-LPN-TH-93-15