Is strong CP invariance due to a massless up quark?

A standing mystery in the Standard Model is the unnatural smallness of the strong CP violating phase. A massless up quark has long been proposed as one potential solution. A lattice calculation of the constants of the chiral Lagrangian essential for the determination of the up quark mass, 2 alpha_8 - alpha_5, is presented. We find 2 alpha_8 - alpha_5 = 0.29 +/- 0.18, which corresponds to m_u / m_d = 0.410 +/- 0.036. This is the first such calculation using a physical number of dynamical light quarks, N_f = 3.Comment: 4 pages, 5 figures, submitted to Phys. Rev. Lett., corrected small normalization error in f_pi (conclusions were unaffected), improved lattice spacing analysis, improved finite volume analysi

Lessons Learned from Incorporating Climate Considerations in the Three Rivers Watershed-Based Plan

The South Carolina Department of Health and Environmental Control has recently incentivized planners to incorporate climate change projections into watershed-based plans. Methods for doing so vary by geography, specific basin-level conditions, and available resources. This short communication documents an early example developed by a collaborative team including a council of governments, private contractor, and university researchers. We outline steps taken to construct climate change scenarios, incorporate them into a basin-level model, and develop a holistic approach to climate adaptation and resilience for the Three Rivers Watershed-Based Plan in the Columbia, South Carolina, metropolitan area. We present lessons learned about integrating appropriate climate change scenarios with hydrological tools and incorporating a community development strategy that addresses freshwater pollution and integrates cobenefits and equitable adaptation frameworks into the watershed-based planning process

The mechanism of energy transfer in the bacterial photosynthetic reaction center

In the accompanying paper (Scholes, G. D.; Jordanides, X. J.; Fleming, G. R. J. Phys. Chem. 2001, 105, 1640, a generalization of Förster theory is developed to calculate electronic energy transfer (EET) in molecular aggregates. Here we apply the theory to wild-type and mutant photosynthetic reaction centers (RCs) from Rb. sphaeroides, as well as to the wild-type RC from Rps. Viridis. Experimental information from the X-ray crystallographic structure, resonance Raman excitation profiles, and hole-burning measurements are integrated with calculated electronic couplings to model the EET dynamics within the RC complex. Optical absorption and circular dichroism spectra are calculated at various temperatures between 10 K and room temperature, and compare well with the experimentally observed spectra. The calculated rise time of the population of the lower exciton state of P, P -, as a result of energy transfer from the accessory bacteriochlorophyll, B, to the special pair, P, in Rb. sphaeroides (Rps. Viridis) wild-type at 298 K is 193 fs (239 fs), and is in satisfactory agreement with experimental results. Our calculations, which employ a weak-coupling mechanism suggest that the upper exciton state of P, P + plays a central role in trapping excitation from B. Our ability to predict the experimental rates is partly attributed to a proper calculation of the spectral overlap J δR ( ) using the vibronic progressions. The main advance we have made, however, is to calculate the electronic couplings V δR in terms of the molecular composition of donor and/or acceptor aggregates, rather than treating the acceptors P + and P -as point dipoles associated with each spectroscopic band. Thus, we believe our electronic couplings capture the essence of the many-body interactions within the RC. Calculations for EET in two mutants, (M)-L214H (the beta mutant) and (M)H202L (the heterodimer), are in reasonable agreement with experimental results. In the case of the heterodimer the agreement depends on a decrease in the electronic couplings between D M and the rest of the pigments

Climate Data Empathy

In the era of climate services, which provide globally complete data products in a ready-to-use form, the context of climate data is in danger of being neglected or forgotten. However, the historical and present-day context imprinted on this climate data is important in its own right. The data depend on political, economic and technological factors, as we show with a range of data coverage maps. We term awareness of and sensitivity to this context-dependence “climate data empathy,” and argue that context should be seen as a source of information to be communicated along with the data. Such context not only provides additional information about the data products, but may help in designing communication strategies and contribute more generally to raising awareness of the contingency of environmental data. Decision making should thus make use of both climate data and its context

The First Extrasolar Planet Discovered with a New Generation High Throughput Doppler Instrument

We report the detection of the first extrasolar planet, ET-1 (HD 102195b), using the Exoplanet Tracker (ET), a new generation Doppler instrument. The planet orbits HD 102195, a young star with solar metallicity that may be part of the local association. The planet imparts radial velocity variability to the star with a semiamplitude of $63.4\pm2.0$ m s$^{-1}$ and a period of 4.11 days. The planetary minimum mass ($m \sin i$) is $0.488\pm0.015$ $M_J$.Comment: 42 pages, 11 figures and 5 tables, Accepted for publication in Ap

Pediatric severe asthma with fungal sensitization is mediated by steroid-resistant IL-33

Background: The mechanism underlying severe asthma with fungal sensitization (SAFS) is unknown. IL-33 is important in fungus-induced asthma exacerbations, but its role in fungal sensitization is unexplored. Objective: We sought to determine whether fungal sensitization in children with severe therapy-resistant asthma is mediated by IL-33. Methods: Eighty-two children (median age, 11.7 years; 63% male) with severe therapy-resistant asthma were included. SAFS (n= 38) was defined as specific IgE or skin prick test response positivity to Aspergillus fumigatus, Alternaria alternata, or Cladosporium herbarum. Clinical features and airway immunopathology were assessed. Chronic exposure to house dust mite and A alternata were compared in a neonatal mouse model. Results: Children with SAFS had earlier symptom onset (0.5 vs 1.5 years, P= .006), higher total IgE levels (637 vs 177 IU/mL, P= .002), and nonfungal inhalant allergen-specific IgE. Significantly more children with SAFS were prescribed maintenance oral steroids (42% vs 14%, P= .02). SAFS was associated with higher airway IL-33 levels. In neonatal mice A alternata exposure induced higher serum IgE levels, pulmonary IL-33 levels, and IL-13+ innate lymphoid cell (ILC) and TH2 cell numbers but similar airway hyperresponsiveness (AHR) compared with those after house dust mite exposure. Lung IL-33 levels, IL-13+ ILC numbers, TH2 cell numbers, IL-13 levels, and AHR remained increased with inhaled budesonide during A alternata exposure, but all features were significantly reduced in ST2-/- mice lacking a functional receptor for IL-33. Conclusion: Pediatric SAFS was associated with more oral steroid therapy and higher IL-33 levels. A alternata exposure resulted in increased IL-33-mediated ILC2 numbers, TH2 cell numbers, and steroid-resistant AHR. IL-33 might be a novel therapeutic target for SAFS