Transverse momentum dependence of the angular distribution of the Drell-Yan process

We calculate the transverse momentum Q_{\perp} dependence of the helicity structure functions for the hadroproduction of a massive pair of leptons with pair invariant mass Q. These structure functions determine the angular distribution of the leptons in the pair rest frame. Unphysical behavior in the region Q_{\perp} --> 0 is seen in the results of calculations done at fixed-order in QCD perturbation theory. We use current conservation to demonstrate that the unphysical inverse-power and \ln(Q/Q_{\perp}) logarithmic divergences in three of the four independent helicity structure functions share the same origin as the divergent terms in fixed-order calculations of the angular-integrated cross section. We show that the resummation of these divergences to all orders in the strong coupling strength \alpha_s can be reduced to the solved problem of the resummation of the divergences in the angular-integrated cross section, resulting in well-behaved predictions in the small Q_{\perp} region. Among other results, we show the resummed part of the helicity structure functions preserves the Lam-Tung relation between the longitudinal and double spin-flip structure functions as a function of Q_{\perp} to all orders in \alpha_s.Comment: 18 pages, 4 figures; typos corrected, references updated, a few clarifications recommended by the referee. Paper accepted for publication in Physical Review

Click-Gap, paternalism, and tech giants’ relationships with their users

The spread of misinformation and fake news raises important problems for our society and for our democracy. From the January 6 attack on the U.S. Capitol to vaccine hesitancy, from suppressing voter turnout to peddling conspiracy theories, we know that these problems are real and need to be taken seriously. While misinformation is not a new problem for democracy, it can spread more quickly and easily because of new media’s design and popularity. Given these problems, it is encouraging that some technology companies are taking steps to reduce the spread of misinformation and fake news on the platforms they manage. Despite this seemingly positive development, some scholars have criticized some interventions designed to combat the spread of misinformation and fake news as paternalistic. For example, a 2019 Facebook intervention called Click-Gap aimed to reduce the amount of low-quality content (including fake news and misinformation) that users see on their NewsFeed. Click-Gap has been criticized as an instance of epistemic paternalism because it was adopted (1) with the goal of improving the epistemic status of its users and (2) irrespective of what the company believed the wishes of its users to be. If interventions like Click-Gap are problematic because paternalistic, those of us interested in the ethics of technology would face a dilemma—either endorse technology companies treating their users paternalistically or endorse their failing to act to combat the spread of misinformation and fake news on their platforms. Both options seem to me to be problematic. While paternalism may sometimes be permissible, I think we should be very hesitant to endorse a paternalistic relationship between technology companies and their users. The relationship does not seem to bear the right sort of structure to one in which paternalism might be appropriate, if it ever is. The second option seems, if anything worse: surely technology companies should not stand by and change nothing about their platforms despite the spread of misinformation and fake news in those spaces. In this paper, I argue that Click-Gap and interventions like it are not paternalistic, contrary to the conclusion of other scholars. Further, I will argue that the focus on paternalism itself is actually a red herring here. While not just any intervention or strategy that purports to reduce fake news and misinformation is permissible, we should want technology companies to take user well-being seriously and be able to take that well-being as a direct reason for action. Their doing so is not paternalistic nor even morally problematic, and it should not be criticized as such

An Intercomparison of Four Models of Current Meter in High Current Conditions in Drake Passage

Seven current meters representing four models were placed for an 11 month deployment on a stiffly buoyed mooring to intercompare their velocity measurements: two VMCMs, two Aanderaa RCM11s, two Aanderaa SEAGUARDSs, and a Nortek Aquadopp. The current meters were placed 6 m apart from each other at about 4000 m depth in an area of Drake Passage expected to have strong near-bottom currents, that were nearly independent of depth. Two high-current events occurred in bursts of semi-diurnal pulses lasting several days, one with peak speeds up to 67 cm/s and the other above 35 cm/s. The current speed measurements all agreed within about 5% when vector-averaged over simultaneous time intervals: the full time interval (198 days) when all instruments were working, and the two high-speed events lasting 21 days and 7 days. The VMCMs, chosen as the reference measurements, were found to measure the median of the mean-current magnitudes. The RCM11 and SEAGUARD current speeds had a nearly 1:1 relationship with the median. They agreed within 2% at higher speeds (35-70 cm/s), whereas in lower speed ranges (0-35 cm/s) the vector-averaged speeds for the RCM11s and SEAGUARDS were, respectively, 4-5% lower and 3-5% higher than the median. The Aquadopp current speeds were about 7% higher than the VMCMs over the range (0-40 cm/s) encountered through their shorter common time period

Cascadia Pilot Experiment Data Report

This report documents the processing of data collected from an line of inverted echo sounders equipped with bottom pressure gauges and current meters (CPIES) deployed offshore of Oregon in the Cascadia subduction zone region from April to November 2017. The line consisted of four URI-model CPIES across the continental slope, spanning water depths from 2900 m to 1300 m. From offshore to onshore, the sites were designated O1, O1.5, O2 and O3. The instrument spacing telescoped toward the coast from 3.5 km to 7 km to 9 km. CTDs were taken at each site on the deployment and recovery cruises. Additionally, two Sonardyne-model PIES (lacking the integrated current meter) were colocated at the deepest and shallowest sites (O1 and O3) for comparison tests. An Aanderaa Seaguard current meter was moored in August 2017 at site O2 because the status of CPIES current meter at that location was uncertain

Responsiveness of PROMIS® to change in chronic obstructive pulmonary disease.

BackgroundChronic obstructive pulmonary disease (COPD) is a progressive chronic disease characterized by airflow obstruction that leads to shortness of breath and substantial negative impacts on health-related quality of life (HRQL). The course of COPD includes periodic acute exacerbations that require changes in treatment and/or hospitalizations. This study was designed to examine the responsiveness of Patient-Reported Outcomes Measurement Information System® (PROMIS®) measures to changes associated with COPD exacerbation recovery.MethodsA longitudinal analysis using mixed-effects models was conducted of people who were enrolled while stable (n = 100) and those who experienced an acute exacerbation (n = 85). PROMIS (physical function, pain interference, pain behavior, fatigue, anxiety, depression, anger, social roles, discretionary social activities, Global Health, dyspnea severity and dyspnea functional limitations) and COPD-targeted HRQL measures were completed at baseline and at 12 weeks.ResultsWe administered PROMIS measures using computer adaptive testing (CAT), followed by administration of any remaining short form (SF) items that had not yet been administered by CAT. Examination of the difference between group differences from baseline to 12 weeks in the stable and exacerbation groups revealed that the exacerbation group changed (improved) significantly more than the stable group in anxiety (p < .001 to p < .01; f2 effect size [ES] = 0.023/0.021), fatigue (p < .0001; ES = 0.036/0.047) and social roles (p < .001 to p < .05; ES = 0.035/0.024). All effect sizes were small in magnitude and smaller than hypothesized. Depression was also statistically significant (p < .05, SF only) but the ES was trivial. For all other PROMIS domains, the differences were not significant and ES were trivial.ConclusionsThis longitudinal study provides some support for the validity of the PROMIS fatigue, anxiety, and social roles domains in COPD, but further evaluation of responsiveness is warranted

PIES and CPIES Data Processing Manual

The Inverted Echo Sounder (IES) is an ocean bottom-moored instrument that measures the vertical acoustic travel time (VATT) round-trip from the seafloor to the sea surface and back. The VATT varies principally due to changes in the temperature profile of the water column, making the IES well-suited for monitoring changes in temperature structure and dynamic height (baroclinic signal). Currently, the Model 6.2, a combined IES, data-logger, and acoustic release, with measurements of bottom pressure and temperature (PIES) and optional measurements of current speed and direction (CPIES, with attached Aanderaa Doppler current sensor) is produced at URI/GSO. Data are processed in situ and are available (optional) remotely by an acoustic telemetry link. In addition to the IES-measured baroclinic signals, barotropic near-bottom pressure variations may be measured with the optional pressure sensor. A report was written in 1991 describing IES data processing [Fields et al., 1991]. Since that report, significant improvements have been made to both IES hardware and software, warranting an update of the IES data processing. The report by Kennelly et al. [2007] documents the standard processing steps contained in IESpkg 3, which has been used since the early 2000s, for IES/PIES/CPIES Models 6.1 and 6.2 at URI/GSO. More recently, IESpkg 4 was developed to allow more flexibility in the processing steps and data outputs, and to process the Fast PIES versions that sample 96 travel times each hour. This report documents the processing steps in IESpkg 4 and it repeats as much of the original text of Kennelly et al. [2007] as is still applicable. A separate document, Inverted Echo Sounder User\u27s Manual, IES Model 6.2, describes the IES hardware and instrument configuratio

Radio-frequency powered glow discharge device and method with high voltage interface

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor\u27s terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe\u27s components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe\u27s components from electrically shorting the cell\u27s components

Estimates of Eddy Heat Flux Crossing the Antarctic Circumpolar Current from Observations in Drake Passage

The 4-yr measurements by current- and pressure-recording inverted echo sounders in Drake Passage produced statistically stable eddy heat flux estimates. Horizontal currents in the Antarctic Circumpolar Current (ACC) turn with depth when a depth-independent geostrophic current crosses the upper baroclinic zone. The dynamically important divergent component of eddy heat flux is calculated. Whereas full eddy heat fluxes differ greatly in magnitude and direction at neighboring locations within the local dynamics array (LDA), the divergent eddy heat fluxes are poleward almost everywhere. Case studies illustrate baroclinic instability events that cause meanders to grow rapidly. In the southern passage, where eddy variability is weak, heat fluxes are weak and not statistically significant. Vertical profiles of heat flux are surface intensified with ~50% above 1000 m and uniformly distributed with depth below. Summing poleward transient eddy heat transport across the LDA of −0.010 ± 0.005 PW with the stationary meander contribution of −0.004 ± 0.001 PW yields −0.013 ± 0.005 PW. A comparison metric, −0.4 PW, represents the total oceanic heat loss to the atmosphere south of 60°S. Summed along the circumpolar ACC path, if the LDA heat flux occurred at six “hot spots” spanning similar or longer path segments, this could account for 20%–70% of the metric, that is, up to −0.28 PW. The balance of ocean poleward heat transport along the remaining ACC path should come from weak eddy heat fluxes plus mean cross-front temperature transports. Alternatively, the metric −0.4 PW, having large uncertainty, may be high

A retrospective study of two populations to test a simple rule for spirometry

Abstract Background Chronic lung disease is common and often under-diagnosed. Methods To test a simple rule for conducting spirometry we reviewed spirograms from two populations, occupational medicine evaluations (OME) conducted by Saint Louis and Wake Forest Universities at 3 sites (n = 3260, mean age 64.14 years, 95 % CI 58.94–69.34, 97 % men) and conducted by Wake Forest University preop clinic (POC) at one site (n = 845, mean age 62.10 years, 95 % CI 50.46–73.74, 57 % men). This retrospective review of database information that the first author collected prospectively identified rates, types, sensitivity, specificity and positive and negative predictive value for lung function abnormalities and associated mortality rate found when conducting spirometry based on the 20/40 rule (≥20 years of smoking in those aged ≥ 40 years) in the OME population. To determine the reproducibility of the 20/40 rule for conducting spirometry, the rule was applied to the POC population. Results A lung function abnormality was found in 74 % of the OME population and 67 % of the POC population. Sensitivity of the rule was 85 % for an obstructive pattern and 77 % for any abnormality on spirometry. Positive and negative predictive values of the rule for a spirometric abnormality were 74 and 55 %, respectively. Patients with an obstructive pattern were at greater risk of coronary heart disease (odds ratio (OR) 1.39 [confidence interval (CI) 1.00–1.93] vs. normal) and death (hazard ratio (HR) 1.53, 95 % CI 1.20–1.84) than subjects with normal spirometry. Restricted spirometry patterns were also associated with greater risk of coronary disease (odds ratio (OR) 1.7 [CI 1.23–2.35]) and death (Hazard ratio 1.40, 95 % CI 1.08–1.72). Conclusions Smokers (≥ 20 pack years) age ≥ 40 years are at an increased risk for lung function abnormalities and those abnormalities are associated with greater presence of coronary heart disease and increased all-cause mortality. Use of the 20/40 rule could provide a simple method to enhance selection of candidates for spirometry evaluation in the primary care setting