United States Air Force Academy Research Articles

Crossflow Instability on a Swept Fin–Cone with Variable Nose Bluntness in Mach 6 Flow

Experiments and computational analysis have been conducted to study instabilities in the boundary layer over a swept fin–cone geometry in hypersonic flow. Experiments were carried out at the United States Air Force Academy’s Mach 6 Ludwieg Tube. Infrared thermography was employed to assess the surface temperature distribution, particularly the thermal striations on the fin that indicated a crossflow-dominated transition. Increasing the unit Reynolds number increased heating and moved the crossflow-transition front closer to the fin leading edge. Stability analysis based on the linear parabolized stability equations identified unstable stationary crossflow modes across the range of tested unit Reynolds numbers, and the most amplified disturbances were found to have wavelengths of 2–4 mm. The experimentally observed thermal striations were analyzed and found to have initial wavelengths of 2–5 mm but eventually formed higher-amplitude structures with a wavelength of approximately 10 mm. Discrete roughness elements of different diameters and spacings were implemented near the fin leading edge. Boundary-layer transition onset was found to be delayed with a subsequent lowering of the fin surface heating, with discrete roughness elements having a wavelength of 13.33 mm.

Lens X: A Practical Approach to Taking Care of Your People

Graduates of the United States Air Force Academy (USAFA), as commissioned officers, are charged to “take care of their people.” While this leadership aphorism makes sense, this article describes what it means in practice. An interdisciplinary USAFA team explored the dynamics of leader development from multiple angles, resulting in a focus on two dimensions (or “lenses”) that help a leader understand what actions can be taken to help an employee achieve subjective well-being at work. The intent is to draw attention to the nature of the interaction with organizational members that foster engagement and need fulfillment. We do that by focusing a leader’s attention on needs, narratives, and micro-exchanges. Those interactions, behaviors, and micro-exchanges are the foundations of and the most tangible, changeable element of climate and culture. This practical lens equips any leader to seize every opportunity to foster fulfillment of the psychological needs for belonging, agency, and efficacy. This framework can be used by anyone but is particularly relevant to supervisors and USAFA cadets who will be entrusted to lead an all-volunteer military force.

Operationalizing the Human Condition, Cultures, and Societies Outcome through the National Character and Leadership Symposium

This paper focuses on the Human Condition, Cultures, and Societies institutional outcome at the United States Air Force Academy (USAFA) and highlights the connection between the outcome and the 2024 National Character and Leadership Symposium (NCLS) theme. Each year, the symposium provides the USAFA community and visitors the opportunity to learn from and engage with nationally recognized speakers. Interactions allow participants to contemplate not only the importance of valuing the human condition but also engage concertedly and compassionately with others. Every four years, the NCLS theme is rooted in the institutional outcome of the Human Condition, Cultures, and Societies. This year’s theme places particular emphasis on precisely the need to know oneself, know others, and to elevate performance through constructive engagement to make a difference, namely learning what each can and must do to value the human condition and human beings. The authors explore how USAFA operationalizes the importance of understanding the human condition as participants transition from the academic classroom to the field to the Air Force and Space Force.

Undergraduate Management Research as Deliberate Development of Leaders of Character?

The United States Air Force Academy’s mission is to “educate, train, and inspire men and women to become officers of character motivated to lead the U.S. Air Force and Space Force in service to our nation.” Leaders of character are expected to (1) Live Honorably, (2) Lift Others, and (3) Elevate Performance through three critical steps of owning, engaging, and practicing their own development journey. The Cadet Summer Research Program (CSRP) is an institution-wide program that provides selected cadets the opportunity to function as independent adults while conducting research outside the classroom, in both military and civilian institutions. Cadets work on research projects in partnership with organizations across the country and are expected to produce results with real-world applications. Given the considerations explored above, we undertook a nascent exploration of the connection between management majors’ CSRP journey and our deliberate approach in developing leaders of character. We strongly suggest that CSRP, as experienced by management majors, unfolds as a transformative experience that contributes to cadets owning the pursuit of their own identity, engaging in purposeful experiences, and practicing habits of thought and action. During this multifaceted process, cadets put into practice what it takes to live honorably, lift others, and elevate performance in socio-technical systems. In many ways, these systems replicate those they will serve as officers, better preparing them to lead in future conflicts.

Development of Emotional Intelligence During an Adventure and Experiential-Based Learning Course

Background The United States Air Force Academy's Center for Character and Leadership Development developed the ‘Adventure and Experiential Based Learning’ (AEBL) course—a new experiential education summer course intended to develop interpersonal leadership skills in 1,100 sophomore cadets. Purpose Improving cadet emotional intelligence (EI) is of particular focus due to its value in leader effectiveness. Methodology/Approach Rather than rely upon the more common military pedagogy of lecture-based learning or a military handbook that prescribes exactly what participant success looks like, the aim of the course examined in this study was to improve participant EI via a combination of experiential education methods including interactive classwork, challenge course experimentation, and a capstone 28-h adventure comprised of uncertainty and stressful team dynamics. To measure the effect the experiential education curriculum had on participant EI, the Workgroup Emotional Intelligence Profile (WEIP) was used in a pre/postsurvey method. Findings/Conclusion The results indicated a significant increase in EI among AEBL participants as measured by the WEIP. Implications Outdoor experiences like the one described in this article may be an effective way to train EI skills.

Classification of SUAS propellers with auditory feature extraction methods

A measurement of one stock and three custom designed propellers was conducted with the United States Air Force Academy. The measurement consisted of a constant radius arc, and a radial array to examine acoustic attributes as a function of distance and angle. During the measurement activity the experimenters' observed that each propeller possessed different audio attributes that assisted in distinguishing the stock from any of the custom propellers. To adequately explore attributes beyond the propeller's A-weighted level as a function of thrust, a timbre and sound quality analysis were conducted. These auditory feature extraction methods were combined with a fractional octave analysis into a database for machine learning classification analysis. The new baseline propeller is distinguished by the acoustic roughness alone, but the other blade designs require additional timbre features to be segregated from the stock propeller.

Identifying Host Cell Gene Expression Modulation as Potential Markers for SARS-CoV2 Infection

Background The SARSCoV2 emergence in 2019 has caused health, safety, and socioeconomic issues around the world. Current testing prioritizes viral RNA detection, requiring specialized techniques, training, and time periods, resulting in significant testing limitations. Viral infection can cause changes in host cell gene expression, which vary from virus to virus. Recent research suggests SARSCoV2-induced gene expression modulations in infected human cells may be differentiated from expressions elicited by other acute respiratory illnesses. Data in this study highlight specific genes that are differentially expressed during SARSCoV2 infection. This novel application of individual sample analysis in connection with global databases, provides robust data for genes that are specifically modulated during SARSCoV2 infection. This expression profile would be valuable for SARSCoV2 testing, prevention, treatment, and basic virology research. Methods Previously collected COVID-19 surveillance-testing samples from cadets at the United States Air Force Academy were used to quantify the expression of 19 target genes using direct primer-mediated qRTPCR. Additionally, samples were analyzed with RNA-seq to assess the different transcriptomes between uninfected and SARSCoV2-infected samples. Results were compared with national databases to confirm agreement with the results. Results 19 genes were identified to be altered during SARSCoV2 infection using in-lab experimental results. This expression profile matches previous research and may uniquely describe SARSCoV2 infection. The genes expected to be upregulated according to previous research, IL1B, IFI44L, ACE2 & DUX3, were all upregulated. RNA-seq data confirms these results and identified 122 other genes that are significantly different between uninfected and SARSCoV2 infected samples. The results have a 93% agreement rate with national databases. Conclusion Despite the availability of vaccines for SARSCoV2, the continual mutation and evolution of the virus, the emergence of novel and increasingly infectious strains, and the anti-vaccine sentiment increase the need for safe and rapid testing alternative options. The expression profile of altered host genes during SARSCoV2 infection could be extremely advantageous to detect and prevent infection, as well as further research efforts for treatment and understanding SARSCoV2 infection.

The Academic Genealogy of the Scholars of the Information Systems Discipline Lee Freeman, College of Business, University of Michigan-Dearborn Follow Johann Kranz, Ludwig-Maximilians-University of Munich Andrew Urbaczewski, United States Air Force Academy and University of Denver George Westerman, Massachusetts Institute of Technology

Despite the relative youth of our information systems discipline, many of us do not know the founders of our field or the academic “families” that have helped shape us into what we are today. We have changed greatly over the past few decades, both topically and geographically. As the Information Systems (IS) discipline enters its second half-century, now is a good time to identify the origins of our academic community while some of the founders are still with us. We have created a web-enabled “family tree” of more than 11 thousand IS scholars that investigators can use to examine where we came from, where we are going, and how we can position our field for future academic generations. The genealogical data can be used to show the trajectory of our research, the influences that shape our field, and the influences of organizational designs and the broader environment.

Income variation and excess sensitivity of goods-intensive leisure

We investigate the life-cycle permanent income hypothesis (LCPIH) by estimating the effect of exogenous and predictable income variation on students’ signout activity. Students at the United States Air Force Academy (USAFA) receive monthly stipends that cannot be influenced by their labor supply but have considerable and predictable monthly variation. We also observe their absences from campus, which students are required to document on detailed signout logs, and we believe reflect specifically goods-intensive leisure such as dining and entertainment. We estimate the effect of pay variation on leisure choices using difference-in-differences. A $100 increase in monthly income induces 1.8 additional hours off base and increases the frequency of longer-duration trips. Students also record 27 percent more time away from campus than average in weeks when they receive their monthly stipend. These results suggest a departure from the LCPIH using a novel outcome and in a setting where liquidity constraints and imperfect information do not appear to explain the patterns.

Phylodynamics of a regional SARS-CoV-2 rapid spreading event in Colorado in late 2020.

Since the initial reported discovery of SARS-CoV-2 in late 2019, genomic surveillance has been an important tool to understand its transmission and evolution. Here, we sought to describe the underlying regional phylodynamics before and during a rapid spreading event that was documented by surveillance protocols of the United States Air Force Academy (USAFA) in late October-November of 2020. We used replicate long-read sequencing on Colorado SARS-CoV-2 genomes collected July through November 2020 at the University of Colorado Anschutz Medical campus in Aurora and the United States Air Force Academy in Colorado Springs. Replicate sequencing allowed rigorous validation of variation and placement in a phylogenetic relatedness network. We focus on describing the phylodynamics of a lineage that likely originated in the local Colorado Springs community and expanded rapidly over the course of two months in an outbreak within the well-controlled environment of the United States Air Force Academy. Divergence estimates from sampling dates indicate that the SARS-CoV-2 lineage associated with this rapid expansion event originated in late October 2020. These results are in agreement with transmission pathways inferred by the United States Air Force Academy, and provide a window into the evolutionary process and transmission dynamics of a potentially dangerous but ultimately contained variant.

Beyond Reading, Writing, and Arithmetic: The Role of Teachers and Schools in Reporting Child Maltreatment

Cassandra Benson, Maria D. Fitzpatrick⇑ and Samuel Bondurant Cassandra Benson is an Assistant Professor at the United States Air Force Academy. Samuel Bondurant is the Administrator at the Dallas-Fort Worth Federal Statistical Research Data Center. Maria Fitzpatrick is a Professor of Economics and Public Policy in the Jeb E. Brooks School of Public Policy at Cornell University and Research Associate at the National Bureau of Economic Research. Corresponding author: Maria Fitzpatrick, Department of Economics and Jeb E. Brooks School of Public Policy, Cornell University and NBER. Mail: 3216 Martha van Rensselear Hall, Ithaca, NY 14853. Email: maria.d.fitzpatrick{at}cornell.edu Phone: (607) 255-1272.

The behavior of unconstrained parachute fabric under aerodynamic loading

As parachute systems are required to make precise drops of increasingly heavy equipment, it is important that the simulation tools that are used to develop these systems have relevant data that they can use for validation. Before a detailed validation experiment can be run, it is necessary to understand how these fabrics behave over a wide range of conditions to determine the proper parameter space for the validation tests. In an effort to determine fabric behavior so that specific test points can be selected for validation, minimally constrained squares of F111 nylon fabric were tested in the United States Air Force Academy’s (USAFA’s) low speed wind tunnel and the Army Research Laboratory’s (ARL’s) Microsystem Aeromechanics Wind Tunnel. The tests at USAFA covered different angles of attack, freestream velocities, and amounts of excess length. Testing at ARL was conducted to obtain particle image velocimetry (PIV) measurements around the fabric while simultaneously tracking the motion of the fabric. The results of the experiments with varying excess length indicated that spanwise excess length had a more significant impact on the fabric mean shape and vibrations than excess length in the chordwise direction. Variations in angle of attack and freestream velocity indicated that the minimally constrained fabric experiences large amplitude vibrations at low angles of attack and vibrations beyond the trailing edge are insignificant at angles above 6°. Data from both the USAFA and ARL experiments indicated that this was true even when the leading edge shear layer was separated and undergoing unsteady oscillations. The PIV results from the ARL experiments indicated that at low angles of attack the fabric often experienced unsteady oscillations causing a leading edge region to flip into an up-or-down quasi-stable position. When this flipping occurred it induced vortex shedding which resulted in highly unsteady forces generated by the model. The lack of vibration of the fabric at angles of attack where the leading edge shear layer was undergoing unsteady separation indicates that the material properties of the F111 nylon make it less sensitive to small disturbances when under load. The presence of spanwise pre-strain eliminated large amplitude vibrations of the fabric at low angles of attack and the vortex formation was linked to leading edge oscillations, indicating that the leading edge state drives much of the fluid–structure interaction for minimally constrained fabric.

Better Living through Political Science: On Claudia Hauer's Strategic Humanism

Better Living through Political Science:On Claudia Hauer's Strategic Humanism Konrad Weeda (bio) When my students and I spend a class or two on the Federalist toward the end of a year-long course on the history of political philosophy that began with Plato's Republic, a few passages elicit chuckles or smirks. One is Hamilton's remark in no. 9 that "the science of politics, however, like most other sciences, has received great improvement." The other is Madison's mention in no. 37 of "the greatest adepts in political science."1 Hamilton's optimism could be what causes the smirk. But besides that, it would seem odd, say, to read an article in the science section of the New York Times reporting from the cutting edge of political science. The findings of political scientists fall closer in the space of discourse to the "takes" of pundits than to discoveries in the hard sciences. Madison's "adepts" are just as obscure as Hamilton's "improvement." If an adept in a science is someone with a distinct aptitude for it, do people ever talk about anyone as having an aptitude for political science? A precocious youngster might bring about an advance in computing in her garage; has this ever happened in the study of politics? Even in areas like the prediction of election results, where there have arguably been improvements, improvement seems to owe more to someone's facility with statistics than understanding of politics. But that is enough of explaining jokes where none were meant. If the humor of these passages wasn't the point, then they should lose nothing by being explained. The bulk of this essay will grapple with the consequences of this off-beat humor for teachers and students in the liberal arts. In the main, I want anyone else who is unsettled by a joke about improvements and adepts in political science to [End Page 87] know that we may take heart from Claudia Hauer's Strategic Humanism: Lessons on Leadership from the Ancient Greeks. The very slipperiness of improvement and aptitude in political science are what make "strategic humanism" so necessary, and Hauer's essays on it so refreshing. A tutor at St. John's College in Santa Fe, New Mexico, and professor in the Lyon Chair in Professional Ethics at the United States Air Force Academy, Hauer has written a book that aims in particular to broaden the perspective of people whose jobs require them to formulate military strategy and foreign policy, but which should be known more generally to students and teachers of classics and the liberal arts who are concerned with the public relevance of our disciplines. If I wanted to say that political science cannot really improve, I would say, with Hauer, that this is because human beings are complex wholes for whom theory and practice can never be the same. Theories may develop, but as human activity remains free, it will always get out ahead of theory. In the hard sciences, the matter to be theorized might lie beyond our understanding, but it doesn't get out ahead of it. Newtonian physics missed a great deal about the universe, and awaited improvement until the twentieth century, but its failure to describe the movements of the universe had nothing to do with anybody's decision to act differently. As long as practical reason remains, the human sciences should be on guard against the mindset of the hard sciences where improvements to theory are not liable to get tripped up by the unpredictability of action. In an era when political prognostications are taken with a block of salt but enthusiastically discussed all the same, the "adept in political science" might be a figure both absurd and ridiculous. Aptitude for practical politics is serious, even if the success it brings can be difficult to maintain. If the rewards of political talent are fickle and controversial, those with an aptitude for thinking or speaking about politics are even more dubious. This dramatic picture applies more to the pundit than the actual political scientist, who may not win even pyrrhic victories. Neither of them is like the practitioner of the hard sciences for...

Concussion reporting intentions for incoming military athletes and cadets

ABSTRACT Cultures of concussion reporting exist outside athletics; however, athlete-only studies dominate the literature. Comparing athletes and similar high-risk populations broadens our understanding of concussion reporting acculturation. We aimed to (1) describe and compare concussion self-report willingness as measured by anticipated concussion reporting (ACR), perceived costs, perceived rewards, brain health knowledge, and correct symptom identification for incoming cadets at the United States Air Force Academy (USAFA) (n = 1,136; female = 276, 24.43%) and (2) determine whether those variables predict ACR. Univariate analyses were performed to compare intercollegiate status, sex, and parental income for perceived costs and rewards, and brain health knowledge (α = 0.05) and multinomial logistic regressions to determine if those variables predicted ACR. A $40,000 parental increase in income resulted in one additional symptom identified (β = 0.80, p = 0.026). Athletes demonstrated greater brain health knowledge by nearly one symptom correctly identified (β = 0.98, p = 0.002); non-athletes reported significantly greater ACR (β = 5.92; p < 0.001). Our model accounted for 37% of the variance in ACR (χ2 = 393.86, p < 0.001, Nagelkerke R2 = 0.37). Before military acculturation, athletes had less intention to seek medical care for concussion, likely from prior athletic experiences.

Review: Profiting from the Peak: Landscape and Liberty in Colorado Springs, by John Harner

John Harner’s detailed study of the growth of Colorado Springs connects two stories that are often told separately. The first is the familiar history of William Jackson Palmer’s railroad, tourism, tuberculosis refugees, and Cripple Creek gold that shaped the city’s first seventy years. The second is the development since 1940 of a post-industrial economy based on defense, sports, and conservative Protestantism. The first has been the province of historians, the second more often that of journalists and social commentators. Harner is a geographer who finds essential continuities in both the continuing role of economic boosterism and the ways in which the location itself, epitomized by Pikes Peak, shaped the evolution of the city.The Peak figures in obvious ways as the basis for growing a tourist economy in which everyone with enough money enjoyed mountain views and excursions, but also as the vital source of water in the formative years and the source of gold from its western flank. The aspirational image of a towering mountain helped Colorado Springs win the new Air Force Academy over finalists Lake Geneva, Wisconsin and Alton, Illinois (!). One wonders if the veiled reference in a 1954 Chamber of Commerce brochure was intended—“An ideal location for the United States Air Force Academy, where study reaches its peak due to fine climate and surroundings” (Figure 7.2). Meanwhile, Harmer also traces the economic attraction of clear, dry air from recreational and medical tourism to military training installations to sports headquarters and Olympic training facilities.The other theme is equally interesting. Nineteenth-century urban boosters and twenty-first century economic development professionals are seldom tied up in the same bundle, but Harner’s narrative highlights the similarities between efforts to promote Colorado Springs as a center for curing physical bodies in the sanatorium era and as a center for saving souls through the work of organizations such as Focus on the Family. He argues that the path toward the politically conservative city of recent decades was firmly set by 1900 when a commitment to elite tourism blended with fierce anti-labor ideology after the Cripple Creek strike. Subsequent developments then reinforced each other: full commitment to the military in the 1940s and 1950s, courting of profit-oriented sports bureaucracies, the conservative Christianity that has flourished at the Air Force Academy, the growing importance of military retirees, and the recruitment of evangelical Christian organizations.Harner brings together topics that I have known piecemeal and as components of separate stories and shows me some new connections. The book is richly illustrated with dozens of clearly legible and informative maps, many created or visually annotated by the author, and more dozens of illustrations. Many of the latter are color reproductions taken from tourism brochures in the collection of the Colorado Springs Pioneer Museum, which hosts a related online exhibit. Colorado Springs profited from Pikes Peak and this reviewer has profited from Profiting from the Peak.

An Officer of the Old Guard: Lewis Stephenson Craig, 1807–1852 by William Harris Bragg

Reviewed by: An Officer of the Old Guard: Lewis Stephenson Craig, 1807–1852 by William Harris Bragg Robert Wettemann An Officer of the Old Guard: Lewis Stephenson Craig, 1807–1852. By William Harris Bragg. ( Macon, Ga.: Mercer University Press, 2020. Pp. lvi, 295. $35.00, ISBN 978-0-88146-764-2.) Prominent antebellum U.S. Army leaders and commanders often left paper collections or memoirs readily digested and reexamined by historians and scholars, making new material on the antebellum U.S. Army fruitful for further exploration. Such is the case with William Harris Bragg's study of Lewis Stephenson Craig, which brings Craig's letters, journals, and a heretofore untouched family archive to the forefront. The result is a rich personal portrait of a Virginia gentleman and military officer, who had been denied his plantation by unscrupulous older siblings and guardians and was given an officer's commission when lengthy court battles cost him his inheritance. Abandoning hopes of a place among the Virginia gentry, Craig sought martial glory, gaining a commission as an officer in the Second Dragoons, which he led into the fray in the battle of the Loxahatchee River during the Second Seminole War. Having demonstrated his martial abilities at a time when non–West Point graduates faced prospects of resignation, Craig received a transfer to the Third Infantry regiment. While serving on the southwestern frontier, he not only met and [End Page 158] married Elizabeth Church but also continued to distinguish himself before being ordered to accompany the Third Infantry to the U.S.-Mexican border in anticipation of war. At this point, Bragg's narrative assumes a new form, a deft balance of historical contextualization with excerpts from Craig's journal of his service in the Mexican War. Bragg's efforts are workmanlike as he lets the officer speak: the reader follows Craig in the battles of Palo Alto and Resaca de la Palma, shares in his promotion to captain, and marches into the battle of Monterrey, where the Third Infantry distinguished itself in seizing the city. Craig continues as the dominant narrator, describing his path into the enemy works at the battle of Cerro Gordo and thence down the National Road into central Mexico. Craig's wartime journal concluded with General Winfield Scott's capture of Mexico City and Craig's brevet promotions to major for gallantry in the battle of Monterrey and to lieutenant colonel for his efforts at Contreras and Churubusco. After the war, Craig received an appointment to the Joint United States and Mexico Boundary Commission, functioning as the military escort to those charting the boundary between the two nations. The author's narrative continues to balance Craig's extant journal (it is missing the October 26–November 16, 1851, period) with additional historical context tracing the surveying team's progress. Departing from San Antonio and proceeding to El Paso, Craig chronicled the challenges faced by the infantry company under his command, such as Native attacks and actions by U.S. Army deserters. This latter threat brought an ignominious end to Craig's career, as he was murdered while attempting to apprehend a deserter on June 5, 1852. Bragg is at his best when discussing Craig's experience, effectively describing the social and cultural context of life in the Old South and how a young man looked to military service as an alternative to plantation life. Bragg's deeper understanding of the antebellum U.S. Army is less nuanced. While he repeatedly speaks of military professionalism and national service, Bragg's treatment of those notions with respect to officers' possessing a recognized body of military expertise, their shared responsibilities regarding commitment and national service, and the larger corporate nature of officership is cursory at best, particularly considering Craig's uniqueness in receiving a commission direct from civilian life and otherwise lacking the shared West Point traditions that defined the army officer corps before the Mexican War. These shortcomings notwithstanding, Bragg is to be credited for making the life of Lewis Stephenson Craig available to future scholars of the antebellum U.S. Army. Robert Wettemann United States Air Force Academy Copyright © 2022 The Southern Historical Association

Calibration, sensitivity analysis, and demonstration of a basic polarimeter for artificial satellite observations

The Department of Physics at the United States Air Force Academy has a DFM Engineering f/8.2, 16-inch telescope outfitted with a 9-position filter wheel populated with broadband photometric filters (Johnson-Cousins B, V, R, and a blue-blocking exoplanet filter) and a 100 lines per millimeter diffraction grating. As part of their senior capstone project, physics cadets developed a simple, four-channel linear Stokes polarimeter by populating the open slots in the filter wheel with linear polarization filters oriented at 0°, 45°, 90°, and 135° relative to the vertical axis of the imaging camera. Size and weight restrictions on the back of the telescope prohibited the use of more elaborate polarimeters. They also developed the process and procedures to characterize the effect of the telescope optical elements on the polarization of incident light. Using an unpolarized uniform flat light source, along with a polarized film rotated at 10° increments from 0° to 180°, the intensity of the light source was measured as it passed through the entire optical system including the previously mentioned linear polarized filters. The measured intensities were fitted to Malus Law using a least squares method. From this fit, a modified Mueller matrix was created that describes how the telescope’s optical elements, including the polarizing filters, alter the incident light measured by the telescope’s camera. To relate the measured intensities of light to the Stokes parameters of the light reflected from a satellite, a calibration matrix was computed using a pseudoinverse of the modified Mueller matrix. The sensitivity of the pseudoinverse process was analyzed by perturbing input data and measuring the root mean square (RMS) error between the perturbed and ideal matrices. This process for employing the pseudoinverse introduced minimal error into the system as the RMS error for the calibration matrix was within an acceptable error range. The calibration matrix was applied to observations of three different satellites, AMC-15, DirecTV-10, and DirecTV-14, resulting in their measured Stokes parameters, Degree of Linear Polarization, and Angle of Linear Polarization.

The Effects of Professor Gender on the Post-Graduation Outcomes of Female Students

Although women earn approximately 50 percent of science, technology, engineering and math (STEM) bachelor’s degrees, more than 70 percent of scientists and engineers are men. We explore a potential determinant of this STEM gender gap using newly collected data on the career trajectories of United States Air Force Academy students. Specifically, we examine the effects of being assigned female math and science professors on occupation choice and postgraduate education. We find that, among high-ability female students, being assigned a female professor leads to substantial increases in the probability of working in a STEM occupation and the probability of receiving a STEM master’s degree. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Investigation of Aerobic and Muscular Fitness and Concussion Among Service Academy Cadets at the United States Air Force Academy: Results from the CARE Consortium.

Concussion has become the signature injury facing the U.S. military. However, little is understood about the relationship between military fitness and concussion recovery. The current study examined the recoveries of cadets at a U.S. Service Academy to determine whether preinjury physical fitness improved recovery and whether recovery was associated with post-injury physical fitness measures. Participants were enrolled in a longitudinal study of concussion. Aerobic Fitness Test (AFT) and Physical Fitness Test (PFT) data were used to estimate cadet fitness. Survival analysis evaluated significant estimators of concussion recovery time. Linear regression models were used to explore the relationship between recovery duration and change in physical fitness scores. Between 2014 and 2017, 307 (n = 70; 22.80% Women) cadets who had sustained a concussion were enrolled. Preinjury physical fitness was not significantly associated with recovery duration (P > .05). Men and intercollegiate cadets took fewer days to reach recovery milestones. Compared to women, men had greater decrements in the Aerobic Fitness Test total score (P < .05) and increased 1.5-mile time postconcussion (P < .05). Women had greater decreases in push-ups postconcussion compared to males (P < .05). There was a trend for a negative association between days until asymptomatic and change in the Physical Fitness Test score (P = .07). Preconcussion physical fitness levels do not appear to impact concussion recovery time among a highly physically fit cohort. Possible methods to reduce the effect of symptom duration on strength-related physical fitness should be investigated along with evaluating reductions in strength as a possible mechanism for postconcussion injury risk.

Number of prior concussions predict poorer concussion care seeking in military cadets

ABSTRACT Primary objective: To determine whether concussion history predicts concussion care seeking, self-management practices, or confidence to recognize/report. Research design:Cross-sectional. Methods & procedures: 706 United States Air Force Academy (USAFA) cadets completed survey items regarding concussion history (0,1,2,3+), likelihood of reporting a concussion, self-management, and confidence to recognize/report. We used multivariate ordinal and binary logistic regression models to predict responses using concussion history, sex, and race. Main outcomes & results: cadets with 1 (OR = 0.59, 95%CI:0.43–0.82), 2 (OR = 0.55, 95%CI:0.31–0.98), or 3+ (OR = 0.36, 95%CI:0.17–0.78) concussions while at USAFA had respective 41%, 45%, and 64% lower likelihood to report the concussion scenario (ref = no history, p < .001). USAFA cadets with more extensive concussion histories had higher prevalence of not seeking care for a concussion (p < .001); more strongly endorsed self-management (p = .001–0.010); and had greater confidence in their ability to recognize a concussion (p = .005), but not to report (p = .198–0.413). Conclusions: Prior concussion experiences may deter cadets from seeking medical care for future concussions. Interventions should address concussion history and clinicians should consider how the post-concussion management process might deter care seeking.