Extracting Semantic Orientations of Words using Spin Model

We propose a method for extracting semantic orientations of words: desirable or undesirable. Regarding semantic orientations as spins of electrons, we use the mean field approximation to compute the approximate probability function of the system instead of the intractable actual probability function. We also propose a criterion for parameter selection on the basis of magnetization. Given only a small number of seed words, the proposed method extracts semantic orientations with high accuracy in the experiments on English lexicon. The result is comparable to the best value ever reported.

Resonant Spin-Flavor Conversion of Supernova Neutrinos: Dependence on Electron Mole Fraction

Detailed dependence of resonant spin-flavor (RSF) conversion of supernova neutrinos on electron mole fraction Ye is investigated. Supernova explosion forms a hot-bubble and neutrino-driven wind region of which electron mole fraction exceeds 0.5 in several seconds after the core collapse. When a higher resonance of the RSF conversion is located in the innermost region, flavor change of the neutrinos strongly depends on the sign of 1-2Ye. At an adiabatic high RSF resonance the flavor conversion of bar{nu}_e -> nu_{mu,tau} occurs in Ye 0.5 and inverted mass hierarchy. In other cases of Ye values and mass hierarchies, the conversion of nu_e -> bar{nu}_{mu,tau} occurs. The final bar{nu}_e spectrum is evaluated in the cases of Ye 0.5 taking account of the RSF conversion. Based on the obtained result, time variation of the event number ratios of low bar{nu}_e energy to high bar{nu}_e energy is discussed. In normal mass hierarchy, an enhancement of the event ratio should be seen in the period when the electron fraction in the innermost region exceeds 0.5. In inverted mass hierarchy, on the other hand, a dip of the event ratio should be observed. Therefore, the time variation of the event number ratio is useful to investigate the effect of the RSF conversion.Comment: 16 pages, 33 figures, accepted for publication in Physical Review

A cross-metathesis approach to the stereocontrolled synthesis of the AB ring segment of ciguatoxin

Synthesis of the AB ring segments of ciguatoxin is described. The present synthesis includes a Lewis acid mediated cyclization of allylstannane with aldehyde, cross-metathesis reaction introducing the side chain, and Grieco-Nishizawa dehydration on the A ring.</p

Supernova Neutrino Nucleosynthesis of Light Elements with Neutrino Oscillations

Light element synthesis in supernovae through neutrino-nucleus interactions, i.e., the ν-process, is affected by neutrino oscillations in the supernova environment. There is a resonance of 13-mixing in the O/C layer, which increases the rates of charged-current ν-process reactions in the outer He-rich layer. The yields of 7Li and 11B increase by about a factor of 1.9 and 1.3, respectively, for a normal mass hierarchy and an adiabatic 13-mixing resonance, compared to those without neutrino oscillations. In the case of an inverted mass hierarchy and a non-adiabatic 13-mixing resonance, the increase in the 7Li and 11B yields is much smaller. Observations of the 7Li/11B ratio in stars showing signs of supernova enrichment could thus provide a unique test of neutrino oscillations and constrain their parameters and the mass hierarchy

Concentration-dependent Dual Effects of Hydrogen Peroxide on Insulin Signal Transduction in H4IIEC Hepatocytes

BACKGROUND: Oxidative stress induced by the accumulation of reactive oxygen species (ROS) has a causal role in the development of insulin resistance, whereas ROS themselves function as intracellular second messengers that promote insulin signal transduction. ROS can act both positively and negatively on insulin signaling, but the molecular mechanisms controlling these dual actions of ROS are not fully understood. METHODOLOGY/PRINCIPAL FINDINGS: Here, we directly treated H4IIEC hepatocytes with hydrogen peroxide (H2O2), a representative membrane-permeable oxidant and the most abundant ROS in cells, to identify the key factors determining whether ROS impair or enhance intracellular insulin signaling. Treatment with high concentrations of H2O2 (25-50 µM) for 3 h reduced insulin-stimulated Akt phosphorylation, and increased the phosphorylation of both JNK and its substrate c-Jun. In contrast, lower concentrations of H2O2 (5-10 µM) enhanced insulin-stimulated phosphorylation of Akt. Moreover, lower concentrations suppressed PTP1B activity, suggesting that JNK and phosphatases such as PTP1B may play roles in determining the thresholds for the diametrical effects of H2O2 on cellular insulin signaling. Pretreatment with antioxidant N-acetyl-L-cysteine (10 mM) canceled the signal-promoting action of low H2O2 (5 µM), and it canceled out further impairment of insulin of insulin signaling induced by high H₂O₂ (25 µM). CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that depending on its concentration, H2O2 can have the positive or negative effect on insulin signal transduction in H4IIEC hepatocytes, suggesting that the concentration of intracellular ROS may be a major factor in determining whether ROS impair or enhance insulin signaling

Supernova Neutrino Nucleosynthesis of Light Elements with Neutrino Oscillations

Light element synthesis in supernovae through neutrino-nucleus interactions, i.e., the nu-process, is affected by neutrino oscillations in the supernova environment. There is a resonance of 13-mixing in the O/C layer, which increases the rates of charged-current nu-process reactions in the outer He-rich layer. The yields of 7Li and 11B increase by about a factor of 1.9 and 1.3, respectively, for a normal mass hierarchy and an adiabatic 13-mixing resonance, compared to those without neutrino oscillations. In the case of an inverted mass hierarchy and a non-adiabatic 13-mixing resonance, the increase in the 7Li and 11B yields is much smaller. Observations of the 7Li/11B ratio in stars showing signs of supernova enrichment could thus provide a unique test of neutrino oscillations and constrain their parameters and the mass hierarchy.Comment: 5 pages, 3 figures, accepted for publication in Physical Review Letter

The Combination of Gemcitabine, Cisplatin, and Paclitaxel as Salvage Chemotherapy for Advanced Urothelial Carcinoma

There is no standard second-line or salvage treatment for advanced urothelial carcinoma (UC). Here we investigated the efficacy and safety of gemcitabine, cisplatin, and paclitaxel (GCP) combination chemotherapy as salvage chemotherapy for advanced UC. We retrospectively analyzed the cases of 23 patients with advanced UC who showed progression or recurrence after cisplatin-based chemotherapy. Gemcitabine (1000 mg/m2), and paclitaxel (80 mg/m2) were administered on days 1 and 8. Cisplatin (70 mg/m2) was administered on day 1. The 3-week cycle regimen was repeated until disease progression if it had no intolerable toxicity. The overall response rate was 61% (95%CI, 41-78%). The median overall survival and progression-free survival times were 14 months and 5.5 months, respectively. Of the already known risk factors of chemotherapy for advanced UC, only the performance status was a prognostic factor for OS. Overall, 16 of the 23 patients (70%) experienced grade 3/4 toxicities, and no fatal adverse events were observed. GCP therapy was a promising option as second-line or salvage therapy for advanced UC

Neutrino-Nucleus Reaction Cross Sections for Light Element Systhesis in Supernova Explosions

The neutrino-nucleus reaction cross sections of 4He and 12C are evaluated using new shell model Hamiltoni-ans. Branching ratios of various decay channels are calculated to evaluate the yields of Li, Be, and B producedthrough the ν -process in supernova explosions. The new cross sections enhance the yields of7Li and11B pro-duced during the supernova explosion of a 16.2 M⊙star model compared to the case using the conventionalcross sections by about 10%. On the other hand, the yield of10B decreases by a factor of two. The yieldsof6Li,9Be, and the radioactive nucleus10 Be are found at a level of ∼ 10−11M⊙. The temperature of νµ,τ-and ¯νµ,τ-neutrinos inferred from the supernova contribution of11B in Galactic chemical evolution models isconstrained to the 4.3 − 6.5 MeV range. The increase in the7Li and11B yields due to neutrino oscillations isdemonstrated with the new cross section