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This paper presents the beam dynamics systematic corrections and their uncertainties for the Run-1 dataset of the Fermilab Muong−2Experiment. Two corrections to the measured muon precession frequencyωamare associated with well-known effects owing to the use of electrostatic quadrupole (ESQ) vertical focusing in the storage ring. An average vertically oriented motional magnetic field is felt by relativistic muons passing transversely through the radial electric field components created by the ESQ system. The correction depends on the stored momentum distribution and the tunes of the ring, which has relatively weak vertical focusing. Vertical betatron motions imply that the muons do not orbit the ring in a plane exactly orthogonal to the vertical magnetic field direction. A correction is necessary to account for an average pitch angle associated with their trajectories. A third small correction is necessary, because muons that escape the ring during the storage time are slightly biased in initial spin phase compared to the parent distribution. Finally, because two high-voltage resistors in the ESQ network had longer than designedRCtime constants, the vertical and horizontal centroids and envelopes of the stored muon beam drifted slightly, but coherently, during each storage ring fill. This led to the discovery of an important phase-acceptance relationship that requires a correction. The sum of the corrections toωamis0.50±0.09ppm; the uncertainty is small compared to the 0.43 ppm statistical precision ofωam.

Elbow arthrodesis is an uncommonly performed operation, but it has a specific and niche place in the management of difficult elbow pathology. Many indications and contraindications have been reported, but one of the more challenging aspects of this procedure remains choosing the appropriate angle of fusion. Varying results have been reported along with speculations as to why the fusion may not have been obtained, such as lack of bony structure in the site. Common complications have also been reported most notably fractures distal to the plate. One area of future research is that of the reversibility of this procedure; going from a total elbow arthroplasty to an elbow arthrodesis has been studied well but not so for converting an arthrodesis to an arthroplasty. Elbow arthrodesis remains a valuable but niche solution for complex elbow pathologies that cannot be addressed with other commoner elbow operations.

We present some of the results in the areas of QCD and Electroweak physics for Run II of the DØ experiment at the Fermilab Tevatron. QCD results include dijet angular decorrelations and inclusive jet and dijet cross sections. Electroweak results include the decay of Z bosons to tau pairs and several results on gauge boson pairs. No deviations from the Standard Model have been observed.

The magnetic moment is a fundamental property of particles. The measurement of these magnetic moments and the comparison with the values predicted by the standard model of particle physics is a way to test our understanding of the fundamental building blocks of our world. In some cases, such as for the electron, this comparison has resulted in confirmation of the standard model with incredible precision. In contrast, the magnetic moment of the muon has shown a long-standing disagreement in the measured and the predicted value. There is currently a tantalizing three-standard-deviation difference between the current best measurement (with a precision of 0.54 ppm) and the state-of-the-art standard model prediction. This represents one of the very few experimental hints for physics beyond the standard model. There are currently two major experimental efforts underway to improve the precision of the muon magnetic moment measurement. The first is an evolution of the E-821 experiment, originally located at Brookhaven National Laboratory in the United States. This is experiment, E-989, is located at Fermilab and will measure the spin precession rate of positive muons in a 14-m diameter storage ring using decay positrons. The goal of the experiment is to reduce the current experimental uncertainty by a factor of three. The experiment is currently being constructed and aims to start taking data in 2017. An alternative, and very complementary, experiment is being planned at J-PARC in Japan. This experiment, E-34, will utilize low energy, ultra-cold muons in a much smaller storage ring. This experiment aims for a similar precision to the Fermilab experiment and aims to begin data taking on a similar timescale.

In this article we examine the validity of inferences drawn from readiness tests when placing children in the regular or a 2-year kindergarten program. Using data from nine Virginia school districts, we studied the technical characteristics of four commonly employed readiness tests. Boys, minorities, children of low socioeconomic status, and young children scored consistently lower on all four tests. Three of the four tests were fairly reliable, but the fourth was highly inconsistent for minorities and those younger than 5 years. None of the four tests were impressive predictors of future test performance. The results are interpreted within specific selection and placement policies.

Undergraduate students often struggle to pay for college expenses. The purpose of this study was to examine the effect of student resources on poverty and undergraduate persistence at the University of North Carolina at Greensboro (UNCG). Guided by Payne’s research on poverty defined as a lack of resources, this study served to examine the difference in reported resources for undergraduate students living in poverty compared to those not living in poverty; reported resources between male and female undergraduate students; and reported resources between African American and Caucasian undergraduate students living in poverty. Furthermore, the following student perceptions were also examined: perception of financial status for students living in generational or situational poverty; perception of economic equity with peers of undergraduate student living in poverty; and the impact of lived experiences on undergraduate student persistence. The study included a sequential explanatory mixed-method design. A total of 235 undergraduate students responded to the quantitative survey and 22 undergraduate students participated in qualitative interviews. The data analysis consisted of t test and chi-square, revealing no significant differences between living in poverty and reported resources. Interviews revealed that students took on financial responsibilities when their families could not provide adequate financial support. The issue of undergraduate student poverty is difficult to measure because students may hide the circumstances of their struggles from their peers and professors. Further research on student resources and poverty should be considered to have a positive impact on social change for undergraduate students living in poverty.

We present a new measurement of the positive muon magnetic anomaly, \\(a_\\mu \\equiv (g_\\mu - 2)/2\\), from the Fermilab Muon \\(g\\!-\\!2\\) Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, \\(\\tilde{\\omega}'^{}_p\\), and of the anomalous precession frequency corrected for beam dynamics effects, \\(\\omega_a\\). From the ratio \\(\\omega_a / \\tilde{\\omega}'^{}_p\\), together with precisely determined external parameters, we determine \\(a_\\mu = 116\\,592\\,057(25) \\times 10^{-11}\\) (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain \\(a_\\mu\\text{(FNAL)} = 116\\,592\\,055(24) \\times 10^{-11}\\) (0.20 ppm). The new experimental world average is \\(a_\\mu (\\text{Exp}) = 116\\,592\\,059(22)\\times 10^{-11}\\) (0.19 ppm), which represents a factor of 2 improvement in precision.

A prototype fresh clinical isolate of type Ia group B streptococci (strain 515) can be opsonized by serum containing low levels of antibody. This opsonizing process can also occur in hypogammaglobulinemic serum, confirming its antibody independence, but it does require Ca++ ions and the second component of complement (C2). When formalin-fixed organisms are reacted with whole serum, C4 and C3 are cleaved. These data are strong evidence that this organism can directly activate C1 in the absence of antibody and that this activation leads to the formation of a classical C3 convertase (C4b2a), which cleaves C3. The observation that opsonization can occur in hypogammaglobulinemic serum suggests that complement alone, presumably the fixation of C3b, is sufficient for phagocytes to ingest this pathogen.

The Fermi National Accelerator Laboratory has measured the anomalous precession frequency \\(a^_ = (g^_-2)/2\\) of the muon to a combined precision of 0.46 parts per million with data collected during its first physics run in 2018. This paper documents the measurement of the magnetic field in the muon storage ring. The magnetic field is monitored by nuclear magnetic resonance systems and calibrated in terms of the equivalent proton spin precession frequency in a spherical water sample at 34.7\\(^\\)C. The measured field is weighted by the muon distribution resulting in \\('^_p\\), the denominator in the ratio \\(^_a\\)/\\('^_p\\) that together with known fundamental constants yields \\(a^_\\). The reported uncertainty on \\('^_p\\) for the Run-1 data set is 114 ppb consisting of uncertainty contributions from frequency extraction, calibration, mapping, tracking, and averaging of 56 ppb, and contributions from fast transient fields of 99 ppb.