350 research outputs found
Does the three site Higgsless model survive the electroweak precision tests at loop?
We complete the list of one loop renormalization group equations and matching
conditions relevant for the computation of the electroweak precision parameters
and in the three site Higgsless model. We obtain one-loop formulas for
and expressed in terms of physical observables such as the KK gauge
boson mass , the KK fermion mass , and the KK gauge boson ()
couplings with light quarks and leptons . It is shown that these
physical observables, , and are severely constrained by
the electroweak precision data. Unlike the tree level analysis on the ideally
delocalized fermion, we find that perfect fermiophobity of is ruled out by
the precision data. We also study the cutoff dependence of our analysis.
Although the model is non-renormalizable, the dependence on the cutoff
parameter is shown to be non-significant.Comment: 13pages, 5figures, minor corrections made, references adde
Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory study
The accumulation of manganese (Mn) in drinking water distribution systems (DWDS) is the main reason for ‘black water’ occurrences at customers' taps. Here, we focused on the impact of hydraulic conditions on Mn accumulation in well chlorinated DWDS, particularly on the physical pathway (i.e., the attachment of particulate Mn to the inner pipe surface) and the chemical pathway (i.e., the autocatalytic oxidation of Mn2+ on the surface of accumulated Mn). Mn accumulation on epoxy resin, a typical lining material for distribution pipes in Japan, was observed in laboratory-scale experiments under different water velocity conditions. The results showed that Mn accumulation was significantly enhanced under higher velocity conditions, which was then fitted with the numerical models describing Mn accumulation by the physical and chemical pathways and the detachment. The rate constants for the physical and chemical pathways had a positive relationship with the flow turbulence in the investigated range, suggesting that hydraulic conditions in DWDS play an important role in Mn accumulation. Effects of Mn speciation and water characteristics on the accumulation process were also simulated under various hydraulic conditions. Based on the obtained results, appropriate countermeasures to control manganese accumulation were then discussed
Z to b bbar and Chiral Currents in Higgsless Models
In this note we compute the flavor-dependent chiral-logarithmic corrections
to the decay Z to b bbar in the three site Higgsless model. We compute these
corrections diagrammatically in the "gaugeless" limit in which the electroweak
couplings vanish. We also compute the chiral-logarithmic corrections to the
decay Z to b bbar using an RGE analysis in effective field theory, and show
that the results agree. In the process of this computation, we compute the form
of the chiral current in the gaugeless limit of the three-site model, and
consider the generalization to the N-site case. We elucidate the Ward-Takahashi
identities which underlie the gaugeless limit calculation in the three-site
model, and describe how the result for the Z to b bbar amplitude is obtained in
unitary gauge in the full theory. We find that the phenomenological constraints
on the three-site Higgsless model arising from measurements of Z to b bbar are
relatively mild, requiring only that the heavy Dirac fermion be heavier than 1
TeV or so, and are satisfied automatically in the range of parameters allowed
by other precision electroweak data.Comment: 19 pages, 7 embedded eps figures (additional reference added
Influence of Cigarette Smoking on Estimated Glomerular Filtration Rate (eGFR) in Japanese Male Workers
The link between changes in estimated glomerular filtration rate (eGFR) and cigarette smoking was evaluated in Japanese male workers with a 5-year follow-up. We examined the data of 456 Japanese male workers, aged 22-70 years, who were taking no medications, and from this group, 286 men (43.5±8.2 years) were followed for 5-years. Habits of cigarette smoking were obtained during interviews by well-trained staff. The influence of cigarette smoking on eGFR was evaluated. In the first analysis, there was no significant difference in eGFR between subjects with and without cigarette smoking. In the second analysis, eGFR was significantly reduced after 5 years in all subjects. Changes in eGFR in subjects with cigarette smoking (-1.90±12.31ml/min/1.73m2) were significantly smaller than those in subjects without cigarette smoking (-4.97±12.05ml/min/1.73m2). At follow-up, we found that eGFR was weakly and negatively correlated with the number of cigarettes smoked (/day). The present study indicated that cigarette smoking may be an important modifiable factor for eGFR in Japanese male workers who are not taking any medications
Incidence and Risk Factors of Hypomagnesemia in Head and Neck Cancer Patients Treated with Cetuximab
Background Hypomagnesemia is a common adverse event during cetuximab (Cmab) treatment. However, few reports have investigated the incidence and risk factors of hypomagnesemia in head and neck cancer patients treated with Cmab. Methods We retrospectively reviewed 131 head and neck cancer patients who received Cmab-containing therapy. Main eligibility criteria were ≥3 Cmab administrations, no prior EGFR-directed therapy, and no prophylactic Mg supplementation.Results Median baseline serum Mg level and number of Cmab administrations were 2.2 mg/dl and eight, respectively. Overall incidence of hypomagnesemia was 50.4% (grade 1, 46.6%; grade 2, 3.1%; grade 3, 0%; grade 4, 0.8%) and differed between patients treated with palliative chemotherapy and bioradiation (Cmab and radiation) (63% vs. 24%; p<0.01). Independent risk factors were low baseline serum Mg [Odds ratio (OR) 161.988, 95% confidence interval (CI) 9.436-2780.895], ≥7 Cmab administrations (OR 3.56, 95% CI 1.16-13.98), and concurrent administration of platinum (cisplatin; OR 23.695, 95% CI 5.219-107.574, carboplatin; OR 5.487, 95% CI 1.831-16.439). Respective incidence of hypomagnesemia in patients in high- (concurrent platinum and ≥7 Cmab administrations) and low-risk (no concurrent platinum and <7 Cmab administrations) groups was 66.0% and 6.6% (P<0.001, OR 28.0). Conclusion Cmab is associated with a significant risk of hypomagnesemia in patients with head and neck cancer with longer term administration and concurrent platinum therapy. High-risk patients should be treated with particular care
Dynamical pinning of domain wall in magnetic nanowire induced by Walker breakdown
Transmission probability of a domain wall through a magnetic nanowire is
investigated as a function of the external magnetic field. Very intriguing
phenomenon is found that the transmission probability shows a significant drop
after exceeding the threshold driving field, which contradicts our intuition
that a domain wall is more mobile in the higher magnetic field. The
micromagnetics simulation reveals that the domain wall motion in the wire with
finite roughness causes the dynamical pinning due to the Walker breakdown,
which semi-quantitatively explains our experimental results.Comment: 17 pages, 4 figure
Hydrogen-bond-assisted isotactic-specific radical polymerization of N-vinyl-2-pyrrolidone with tartrate additives in toluene at low temperatures : high-resolution 1H NMR analysis
A diethyl L-tartrate (L-EtTar)-assisted radical polymerization of N-vinyl-2-pyrrolidone has been developed as the first reported example of the synthesis of isotactic-rich poly(N-vinyl-2-pyrrolidone) (PVP). The addition of L-EtTar in toluene at temperatures of –40°C and lower led to a significant increase in the polymer yield by one order of magnitude compared with the reaction in the absence of L-EtTar. Decreasing the polymerization temperature led to increases in the isotacticity of the PVP, with the mm triad reaching 66.4% at −93 °C. 1H NMR measurement at 920 MHz was conducted to establish a reliable strategy for quantifying the triad tacticities. High-temperature NMR measurements at 250 °C were performed using a specially-designed NMR probe, which led to dramatic narrowing of the 1H line width
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