Modeled El Niño-Southern Oscillation Effects on Grain Sorghum under Varying Irrigation Strategies and Cultural Practices

Equatorial sea surface temperatures vary systematically to cause the El Niño southern oscillation (ENSO) that produces predictable weather patterns in North America and may permit longrange climate predictions and eventual proactive summer crop irrigation management. The declining Ogallala Aquifer in the Southern High Plains and consequently limited well capacities challenge producers to adapt cropping practices for irrigation that doesn’t meet crop water demand. Our objective was to evaluate sorghum [Sorghum bicolor (L.) Moench] yield response to ENSO climate-informed management of cultural practices and irrigation strategies on a Pullman soil (fine, mixed, superactive, thermic Torrertic Paleustoll). We used the simulation model SORKAM and long-term (1961–2000) weather records from Bushland, TX, classified by ENSO phase to calculate sorghum grain yields for all combinations of irrigation levels (0.0, 2.5, 3.75, or 5.0 mm d–1), planting day of year (DOY = 135, 156, 176), and cultivar maturity (early, 95 d; medium, 105 d; late, 120 d). Using the September–November Oceanic Niño Index (ONI) to identify ENSO phase, La Niña years had 50 mm less precipitation and a corresponding 14.5% reduction in overall yield to 4550 kg ha–1 for sorghum planted at 16 plants m–2 population. Late maturing cultivars and late planting led to sorghum freeze injury and reduced yields regardless of ENSO phase. While yields consistently increased with irrigation, we conclude that concentrating water to irrigate an area partitioned 2:1 or 1:1 at 3.75- or 5.0-mm d–1 with complementary dryland produced \u3e30% more grain, overall, than uniformly irrigating an area at 2.5 mm d–1

Infrared conductivity of a one-dimensional charge-ordered state: quantum lattice effects

The optical properties of the charge-ordering ($CO$) phase of the one-dimensional (1D) half-filled spinless Holstein model are derived at zero temperature within a well-known variational approach improved including second-order lattice fluctuations. Within the $CO$ phase, the static lattice distortions give rise to the optical interband gap, that broadens as the strength of the electron-phonon ($el-ph$) interaction increases. The lattice fluctuation effects induce a long subgap tail in the infrared conductivity and a wide band above the gap energy. The first term is due to the multi-phonon emission by the charge carriers, the second to the interband transitions accompanied by the multi-phonon scattering. The results show a good agreement with experimental spectra.Comment: 5 figure

Allergen sensitization is associated with increased dna methylation in older men

Background: Variation in epigenetic modifications, arising from either environmental exposures or internal physiological changes, can influence gene expression and may ultimately contribute to complex diseases such as asthma and allergies. We examined the association of asthma and allergic phenotypes with DNA methylation levels of retrotransposon-derived elements. Methods: We used data from 704 men (mean age 73 years) in the longitudinal Normative Aging Study to assess the relationship between asthma, allergic phenotypes and DNA methylation levels of the retrotransposon-derived elements Alu and long interspersed nuclear element (LINE)-1. Retrotransposons represent a large fraction of the genome (>30%) and are heavily methylated to prevent expression. Percent methylation of Alu and LINE-1 elements in peripheral white blood cells was quantified using PCR pyrosequencing. Data on sensitization to common allergens from skin prick testing, asthma and methacholine responsiveness were gathered approximately 8 years prior to DNA methylation analysis. Results: Prior allergen sensitization was associated with increased methylation of Alu (\u3b2 = 0.32 for sensitized vs. nonsensitized patients; p = 0.003) in models adjusted for pack-years of smoking, body mass index, current smoking, air pollutants, percentage of eosinophils, white blood cell count and age. Of the men interviewed, 5% of subjects reported a diagnosis of asthma. Neither Alu nor LINE-1 methylation was associated with asthma. Conclusions: These data suggest that increased DNA methylation of repetitive elements may be associated with allergen sensitization but does not appear to be associated with asthma. Future work is needed to identify potential underlying mechanisms for these relationships

Localizability of Tachyonic Particles and Neutrinoless Double Beta Decay

The quantum field theory of superluminal (tachyonic) particles is plagued with a number of problems, which include the Lorentz non-invariance of the vacuum state, the ambiguous separation of the field operator into creation and annihilation operators under Lorentz transformations, and the necessity of a complex reinterpretation principle for quantum processes. Another unsolved question concerns the treatment of subluminal components of a tachyonic wave packets in the field-theoretical formalism, and the calculation of the time-ordered propagator. After a brief discussion on related problems, we conclude that rather painful choices have to be made in order to incorporate tachyonic spin-1/2 particles into field theory. We argue that the field theory needs to be formulated such as to allow for localizable tachyonic particles, even if that means that a slight unitarity violation is introduced into the S matrix, and we write down field operators with unrestricted momenta. We find that once these choices have been made, the propagator for the neutrino field can be given in a compact form, and the left-handedness of the neutrino as well as the right-handedness of the antineutrino follow naturally. Consequences for neutrinoless double beta decay and superluminal propagation of neutrinos are briefly discussed.Comment: 12 pages, 5 figure