Decay of High-Energy Astrophysical Neutrinos

Existing limits on the non-radiative decay of one neutrino to another plus a massless particle (e.g., a singlet Majoron) are very weak. The best limits on the lifetime to mass ratio come from solar neutrino observations, and are \tau/m \agt 10^{-4} s/eV for the relevant mass eigenstate(s). For lifetimes even several orders of magnitude longer, high-energy neutrinos from distant astrophysical sources would decay. This would strongly alter the flavor ratios from the $\phi_{\nu_e}:\phi_{\nu_{\mu}}:\phi_{\nu_{\tau}} = 1:1:1$ expected from oscillations alone, and should be readily visible in the near future in detectors such as IceCube.Comment: 4 pages, 1 figure. References added. Version to appear in PR

Can μ\mu--ee Conversion in Nuclei be a Good Probe for Lepton-Number Violating Higgs Couplings ?

Motivated by the improving sensitivity, $R$, of experiments on $\mu~Ti \rightarrow e~Ti$ and the enhanced Higgs nucleon interaction, we study this lepton number violating process induced by Higgs exchange. Taking the possible sensitivity, $R \simeq 10^{-16}$, we obtain the constraint on the Higgs-muon-electron vertex, $\kappa_{\mu e}$, to be less than $2.4\times10^{-7}$ if the masses of the Higgs scalar and $W$ gauge boson are the same. $\kappa_{\mu e}$ is also calculated for some models.Comment: 11 pages(revtex 3), TRI-PP-93-7

Detecting Nutau Oscillations as PeV Energies

It is suggested that a large deep underocean neutrino detector, given the presence of significant numbers of neutrinos in the PeV range as predicted by various models of Active Galactic Nuclei, can make unique measurements of the properties of neutrinos. It will be possible to observe the existence of the nu_tau, measure its mixing with other flavors, in fact test the mixing pattern for all three flavors based upon the mixing parameters suggested by the atmospheric and solar neutrino data, and measure the nu_tau cross section. The key signature is the charged current nu_tau interaction, which produces a double cascade, one at either end of a minimum ionizing track. At a few PeV these cascades would be separated by roughly 100 m, and thus be easily resolvable in DUMAND and similar detectors. Future applications are precise neutrino astronomy and earth tomography.Comment: 10 Pages, 2 figs included, 15 May 1994, Preprint DUMAND-3-9

Constraints on decay plus oscillation solutions of the solar neutrino problem

We examine the constraints on non-radiative decay of neutrinos from the observations of solar neutrino experiments. The standard oscillation hypothesis among three neutrinos solves the solar and atmospheric neutrino problems. Decay of a massive neutrino mixed with the electron neutrino results in the depletion of the solar neutrino flux. We introduce neutrino decay in the oscillation hypothesis and demand that decay does not spoil the successful explanation of solar and atmospheric observations. We obtain a lower bound on the ratio of the lifetime over the mass of $\nu_2$, (\tau_2/m_2) > 22.7 (\srm/\MeV) for the MSW solution of the solar neutrino problem and (\tau_2/m_2) > 27.8 (\srm/\MeV) for the VO solution (at 99% C.L.).Comment: 8 pages latex file with 4 figure

Plant cell wall profiling by fast maximum likelihood reconstruction (FMLR) and region-of-interest (ROI) segmentation of solution-state 2D 1H–13C NMR spectra

BACKGROUND: Interest in the detailed lignin and polysaccharide composition of plant cell walls has surged within the past decade partly as a result of biotechnology research aimed at converting biomass to biofuels. High-resolution, solution-state 2D (1)H–(13)C HSQC NMR spectroscopy has proven to be an effective tool for rapid and reproducible fingerprinting of the numerous polysaccharides and lignin components in unfractionated plant cell wall materials, and is therefore a powerful tool for cell wall profiling based on our ability to simultaneously identify and comparatively quantify numerous components within spectra generated in a relatively short time. However, assigning peaks in new spectra, integrating them to provide relative component distributions, and producing color-assigned spectra, are all current bottlenecks to the routine use of such NMR profiling methods. RESULTS: We have assembled a high-throughput software platform for plant cell wall profiling that uses spectral deconvolution by Fast Maximum Likelihood Reconstruction (FMLR) to construct a mathematical model of the signals present in a set of related NMR spectra. Combined with a simple region of interest (ROI) table that maps spectral regions to NMR chemical shift assignments of chemical entities, the reconstructions can provide rapid and reproducible fingerprinting of numerous polysaccharide and lignin components in unfractionated cell wall material, including derivation of lignin monomer unit (S:G:H) ratios or the so-called SGH profile. Evidence is presented that ROI-based amplitudes derived from FMLR provide a robust feature set for subsequent multivariate analysis. The utility of this approach is demonstrated on a large transgenic study of Arabidopsis requiring concerted analysis of 91 ROIs (including both assigned and unassigned regions) in the lignin and polysaccharide regions of almost 100 related 2D (1)H–(13)C HSQC spectra. CONCLUSIONS: We show that when a suitable number of replicates are obtained per sample group, the correlated patterns of enriched and depleted cell wall components can be reliably and objectively detected even prior to multivariate analysis. The analysis methodology has been implemented in a publicly-available, cross-platform (Windows/Mac/Linux), web-enabled software application that enables researchers to view and publish detailed annotated spectra in addition to summary reports in simple spreadsheet data formats. The analysis methodology is not limited to studies of plant cell walls but is amenable to any NMR study where ROI segmentation techniques generate meaningful results. Please see Research Article: http://www.biotechnologyforbiofuels.com/content/6/1/46/

Raising a Small Flock of Sheep in Ohio

PDF pages: 1

Recommendations for reducing energy consumption and improving air quality through energy efficiency in Indian Country: Working paper series--04-04

The strongest recommendation stemming from the Air Pollution Prevention forum of the Western Regional Air Partnership (WRAP) was for tribes to develop and implement energy plans. This paper provides a discussion of the benefits of any such plan and itemized a variety of components of any said plan. A brief discussion of the WRAP is presented is the framework of improving air quality. Based on the background of Jacobs (2000) and Smith (2000), the primary and secondary benefits of energy efficiency plans are then discussed. Then a series of specific recommendations are itemized. These include tribally sponsored programs, collaborative opportunities, and tribal leadership programs