CPT and Lorentz tests with muons

Precision experiments with muons are sensitive to Planck-scale CPT and Lorentz violation that is undetectable in other tests. Existing data on the muonium ground-state hyperfine structure and on the muon anomalous magnetic moment could be analyzed to provide dimensionless figures of merit for CPT and Lorentz violation at the levels of $4\times 10^{-21}$ and $10^{-23}$.Comment: 4 pages, accepted for publication in Physical Review Letter

Model-Independent Global Constraints on New Physics

Using effective-lagrangian techniques we perform a systematic survey of the lowest-dimension effective interactions through which heavy physics might manifest itself in present experiments. We do not restrict ourselves to special classes of effective interactions (such as `oblique' corrections). We compute the effects of these operators on all currently well-measured electroweak observables, both at low energies and at the $Z$ resonance, and perform a global fit to their coefficients. Despite the fact that a great many operators arise in our survey, we find that most are quite strongly bounded by the current data. We use our survey to systematically identify those effective interactions which are {\it not} well-bounded by the data -- these could very well include large new-physics contributions. Our results may also be used to efficiently confront specific models for new physics with the data, as we illustrate with an example.Comment: plain TeX, 68 pages, 2 figures (postscript files appended), McGill-93/12, NEIPH-93-008, OCIP/C-93-6, UQAM-PHE-93/08, UdeM-LPN-TH-93-15

News from the Muon (g-2) Experiment at BNL

The magnetic moment anomaly a_mu = (g_mu - 2) / 2 of the positive muon has been measured at the Brookhaven Alternating Gradient Synchrotron with an uncertainty of 0.7 ppm. The new result, based on data taken in 2000, agrees well with previous measurements. Standard Model evaluations currently differ from the experimental result by 1.6 to 3.0 standard deviations.Comment: Talk presented at RADCOR - Loops and Legs 2002, Kloster Banz, Germany, September 8-13 2002, to be published in Nuclear Physics B (Proc. Suppl.); 5 pages, 3 figure

Naturalness Bounds on Dipole Moments from New Physics

Assuming naturalness that the quantum corrections to the mass should not exceed the order of the observed mass, we derive and apply model-independent bounds on the anomalous magnetic moments and electric dipole moments of leptons and quarks due to new physics.Comment: 4 pages, 2 figure

Towards a sterile insect technique field release of Anopheles arabiensis mosquitoes in Sudan: Irradiation, transportation, and field cage experimentation

<p>Abstract</p> <p>Background</p> <p>The work described in this article forms part of a study to suppress a population of the malaria vector <it>Anopheles arabiensis </it>in Northern State, Sudan, with the Sterile Insect Technique. No data have previously been collected on the irradiation and transportation of anopheline mosquitoes in Africa, and the first series of attempts to do this in Sudan are reported here. In addition, experiments in a large field cage under near-natural conditions are described.</p> <p>Methods</p> <p>Mosquitoes were irradiated in Khartoum and transported as adults by air to the field site earmarked for future releases (400 km from the laboratory). The field cage was prepared for experiments by creating resting sites with favourable conditions. The mating and survival of (irradiated) laboratory males and field-collected males was studied in the field cage, and two small-scale competition experiments were performed.</p> <p>Results</p> <p>Minor problems were experienced with the irradiation of insects, mostly associated with the absence of a rearing facility in close proximity to the irradiation source. The small-scale transportation of adult mosquitoes to the release site resulted in minimal mortality (< 6%). Experiments in the field cage showed that mating occurred in high frequencies (i.e. an average of 60% insemination of females after one or two nights of mating), and laboratory reared males (i.e. sixty generations) were able to inseminate wild females at rates comparable to wild males. Based on wing length data, there was no size preference of males for mates. Survival of mosquitoes from the cage, based on recapture after mating, was satisfactory and approximately 60% of the insects were recaptured after one night. Only limited information on male competitiveness was obtained due to problems associated with individual egg laying of small numbers of wild females.</p> <p>Conclusion</p> <p>It is concluded that although conditions are challenging, there are no major obstacles associated with the small-scale irradiation and transportation of insects in the current setting. The field cage is suitable for experiments and studies to test the competitiveness of irradiated males can be pursued. The scaling up of procedures to accommodate much larger numbers of insects needed for a release is the next challenge and recommendations to further implementation of this genetic control strategy are presented.</p

High precision measurements of the ground state hyperfine structure interval of muonium and of the muon magnetic moment

No description supplie

Use of incisional vacuum-assisted closure in the prevention of postoperative infection in high-risk patients who underwent spine surgery: A proof-of-concept study

© 2019 AANS. Objective: This proof-of-concept study was conducted to determine whether negative-pressure wound therapy, through the use of incisional vacuum-assisted closure (VAC), is associated with a reduction in surgical site infections (SSIs) when compared to standard wound dressings in patients undergoing open posterior spinal fusion who have a high risk of infection. Methods: A total of 64 patients were examined; 21 patients received incisional VAC application (VAC group) versus 43 diagnosis-matched patients who received standard wound dressings (control group). Patients in the VAC group were prospectively enrolled in a consecutive series between March 2013 and March 2014 if they met the following diagnostic criteria for high risk of infection: posterior open surgery across the cervicothoracic junction; thoracic kyphosis due to metastatic disease; high-energy trauma; or multilevel revision reconstructive surgery. Patients in the VAC group also met one or more comorbidity criteria, including body mass index ≥ 35 or \u3c 18.5, diabetes, previous radiation at surgical site, chemotherapy, steroid use, bedridden state, large traumatic soft-tissue disruption, or immunocompromised state. Consecutive patients in the control group were retrospectively selected from the previous year by the same high-risk infection diagnostic criteria as the VAC group. All surgeries were conducted by the same surgeon at a single site. The primary outcome was SSI. All patients had 1 year of follow-up after their surgery. Baseline demographics, intraoperative parameters, and postoperative wound infection rates were compared between groups. Results: Patient demographics including underlying comorbidities were similar, with the exception that VAC-treated patients were malnourished (p = 0.020). VAC-treated patients underwent longer surgeries (p \u3c 0.001) and required more postoperative ICU admissions (p = 0.039). The median length of hospital stay was not different between groups. In total, 9 control patients (21%) developed an SSI, versus 2 VAC-treated patients (10%). Conclusions: Patients in this cohort were selected to have an increased risk of infection; accordingly, the rate of SSI was high. However, negative-pressure wound therapy through VAC application to the postoperative incision resulted in a 50% reduction in SSI. No adverse effects were noted secondary to VAC application. The preliminary data confirm the authors\u27 proof of concept and strongly support the need for a prospective randomized trial