Neutrino scattering and flavor transformation in supernovae.

We argue that the small fraction of neutrinos that undergo direction-changing scattering outside of the neutrinosphere could have significant influence on neutrino flavor transformation in core-collapse supernova environments. We show that the standard treatment for collective neutrino flavor transformation is adequate at late times but could be inadequate in early epochs of core-collapse supernovae, where the potentials that govern neutrino flavor evolution are affected by the scattered neutrinos. Taking account of this effect, and the way it couples to entropy and composition, will require a new approach in neutrino flavor transformation modeling.

C1-esterase inhibitor infusion increases survival rates for patients with sepsis*.

OBJECTIVES: Systemic inflammatory response variability displays differing degrees of organ damage and differing outcomes of sepsis. C1-esterase inhibitor, an endogenous acute-phase protein, regulates various inflammatory and anti-inflammatory pathways, including the kallikrein-kinin system and leukocyte activity. This study assesses the influence of high-dose C1-esterase inhibitor administration on systemic inflammatory response and survival in patients with sepsis. DESIGN: Open-label randomized controlled study. SETTING: Surgical and medical intensive care units of nine university and city hospitals. PATIENTS: : Sixty-one patients with sepsis. INTERVENTIONS: Patients were randomized to receive either 12,000 U of C1-esterase inhibitor infusions in addition to conventional treatment or conventional treatment only (n = 41 C1-esterase inhibitor, 20 controls). Blood samples for measurement of C1-esterase inhibitor, complement components C3 and C4, and C-reactive protein concentrations were drawn on days 1, 3, 5, 7, 10, and 28. MEASUREMENTS AND MAIN RESULTS: Quartile analysis of C1-esterase inhibitor activity in sepsis subjects revealed that the lowest quartile subgroup had similar activity levels (0.7-1.2 U/L), when compared to healthy volunteers (p > .05). These normal-level C1-esterase inhibitor sepsis patients nevertheless displayed increased C-reactive protein (p = .04) production and higher likelihoods of a more severe sepsis (p = .001). Overall, infusion of C1-esterase inhibitor increased C1-esterase inhibitor (p < .005 vs. control on days 2, 3, and 5) functional activity, resulted in higher C3 levels (p < .05 vs. control on days 2 and 3), followed by decreased C-reactive protein (p < .05 vs. control on days 3 and 10). Simultaneously, C1-esterase inhibitor infusion in sepsis patients was associated with reduced all-cause mortality (12% vs. 45% in control, p = .008) as well as sepsis-related mortality (8% vs. 45% in control, p = .001) assessed over 28 days. The highest absolute reduction risk of 70% was achieved in sepsis patients with Simplified Acute Physiology Score II scores >27. CONCLUSION: In the present study, patients in the lowest quartile of C1-esterase inhibitor activity in combination with high C-reactive protein demonstrated a higher risk of developing severe sepsis. In general, high-dose C1-esterase inhibitor infusion down-regulated the systemic inflammatory response and was associated with improved survival rates in sepsis patients, which could have important treatment and survival implications for individuals with C1-esterase inhibitor functional deficiency.

DNA damage-induced phosphorylation of Rad55 protein as a sentinel for DNA damage checkpoint activation in S. cerevisiae.

Rad55 protein is one of two Rad51 paralogs in the budding yeast Saccharomyces cerevisiae and forms a stable heterodimer with Rad57, the other Rad51 paralog. The Rad55-Rad57 heterodimer functions in homologous recombination during the assembly of the Rad51-ssDNA filament, which is central for homology search and DNA strand exchange. Previously, we identified Rad55 protein as a terminal target of the DNA damage checkpoints, which coordinate the cellular response to genotoxic stress. Rad55 protein phosphorylation is signaled by a significant electrophoretic shift and occurs in response to a wide range of genotoxic stress. Here, we map the phosphorylation site leading to the electrophoretic shift and show that Rad55 protein is a bona fide direct in vivo substrate of the central DNA damage checkpoint kinase Mec1, the budding yeast equivalent of human ATM/ATR. We provide protocols to monitor the Rad55 phosphorylation status in vivo and assay Rad55-Rad57 phosphorylation in vitro using purified substrate with the Mec1 and Rad53 checkpoint kinases.