US Navy Research Articles

Jump Landing Kinematics: Establishing Normative Ranges For Male And Female Athletes.

Lower extremity joint (LE) kinematics during landing tasks are important predictors of injury risk and performance outcomes in athletes. To establish sex-related differences and normative ranges for LE kinematics during the jump-landing task in a large cohort of healthy military service academy cadets. Cross-Sectional Study. US Air Force, Naval, and Military Academies. 5308 cadets (2062 females [38.8%]). Sex-related differences in LE kinematics were analyzed using independent samples t-tests. Mean differences (MD) and effect sizes (d) were reported for interpretability. Normative ranges for hip and knee joint angles were established separately for males and females at initial contact (IC) and 50% of the stance phase. Compared to males, moderate effect sizes (d ≥ .5) were observed for knee external rotation (negative value) where females displayed greater motion at IC and at 50% stance (MD: - 3.9˚ and -5.0˚, respectively, p < .001). The following findings were of small effect size (.2 ≥ d > .5). Females exhibited less knee and hip flexion at IC (MD: -1.8˚ and -0.5˚, respectively, p < .001) and at 50% stance (MD: -4.1˚ and -4.6˚, respectfully, p < .001). This was accompanied by females having greater knee valgus (negative value) and hip adduction at IC (MD: -2.2˚ and 1.06˚, respectively, p < .001) and at 50% stance (MD: -3.2˚ and 1.8˚, respectfully, p < .001). This study establishes normative ranges for LE kinematics during the jump-landing task in a large cohort of healthy military service academy cadets entering their first year. Sex- related differences in LE kinematics were observed, highlighting the importance of considering sex as a factor in the evaluation of lower extremity movement quality and management of injury risk.

Anchors Aweigh! The History of Women Surgeons at Sea.

Throughout history, the maritime nations of the world have employed surgeons in sea-going service. The history of women in surgery and the military is well described, but no previous report exists describing the gender breakdown of past and current sea-going US Navy general surgeons. Using literature review, primary sources, personal interviews, and correspondence with Navy Medicine administrative leaders, this historical review describes the evolution of women providing surgical care at sea. During the 1800s and early 1900s, some of the earliest women surgeons in England, America, and Russia began their surgical careers in military service or providing combat casualty care. Women at sea served unpaid nursing roles in the 1700s and provided informal medical care in the 1800s. In 1913 and 1941, 2 different women held medical leadership roles aboard sea-going vessels. Four years after Congress allowed women to serve aboard combatant vessels, Dr Beth Jaklic became the first woman to serve as Ship's Surgeon aboard a US Navy warship in 1997. From 1997 to 2020, 19% of surgeons serving on aircraft carriers were women and one-half of the 20 general surgeons assigned to maritime surgical billets were women in 2022. War and the military environment historically have offered opportunities for women to break boundaries in the world of surgery. Navy Medicine's experience with women surgeons at sea serves as a positive example to the broader surgical community, especially "austere" practices and subspecialties with limited female representation.

Making Local Sense of a Global Disease: The 1918 Influenza Pandemic in Guam

ABSTRACT At the end of October 1918, influenza arrived on Guam aboard a US Navy vessel. It struck quickly and dramatically, killing 5 per cent of the Island’s population in a six-week span. Indeed, more Chamorros died in those six weeks than in the entire previous year. Despite its severity, the 1918 Influenza Pandemic has been largely overlooked in Guam’s histories, as it has also been forgotten in much of the world. This essay provides a historical and historiographical look into the 1918 Influenza Pandemic on Guam, using the deaths of close family members and the transformation of the survivors’ lives as stories meriting greater reflection and remembrance.

Evaluation of the ocean component on different coupled hurricane forecasting models using upper-ocean metrics relevant to air-sea heat fluxes during Hurricane Dorian (2019)

In August 2019 Hurricane Dorian traveled through the Caribbean Sea and Tropical Atlantic before devastating the Bahamas. The operational hurricane forecasting models under-predicted the intensity evolution of Dorian prior to the storm reaching its maximum strength. Research studies have shown that a more realistic upper-ocean characterization in coupled atmosphere-ocean models used to forecast hurricanes has the potential to lead to more accurate hurricane intensity forecasts. In this work, we evaluated four ocean products: the ocean component from one NOAA operational hurricane forecasting model that used ocean initial conditions from climatology, the ocean components from two NOAA experimental models using ocean initial conditions from a data-assimilative operational ocean model, and one US Navy data-assimilative operational ocean model for reference. The upper-ocean metrics used to evaluate the models include mixed layer temperature, mixed layer salinity, ocean heat content and depth-averaged temperature in the top 100 m. The observations used are temperature and salinity profiles from an array of six autonomous underwater gliders deployed in the Caribbean region during the 2019 hurricane season. We found that, even though the four models have good skill in predicting temperature and salinity over the whole observed water column, skill significantly deteriorates for the upper-ocean metrics. In particular, the models failed to capture the barrier layer that was present during the passage of Hurricane Dorian through the glider array. We also found that even small differences in the mixed layer temperature along the storm track on the hurricane models evaluated, led to noticeable differences in the total enthalpy fluxes delivered from the ocean to the atmosphere throughout the storm’s synoptic history. These findings highlight the need to improve the upper-ocean initial conditions and representation in coupled atmosphere-ocean models as part of the larger efforts to improve the various modeling aspects that control the hurricane intensity forecast.

Health and Welfare Benefits of Computerized Cognitive Enrichment in California Sea Lions (Zalophus californianus) at the US Navy Marine Mammal Program.

Cognitive enrichment is becoming more prevalent in professional marine mammal facilities. Research with dolphins has suggested that such enrichment provides more welfare benefits than enrichment that does not incorporate cognitive challenge. However, there is little research supporting the use of cognitive enrichment as a means to improve the welfare of sea lions. Recently, a novel form of technological cognitive enrichment, the Enclosure Video Enrichment (EVE) system, was introduced to a population of California sea lions at the US Navy's Marine Mammal Program as a means to enhance welfare. Two of the initial focal animals introduced to EVE were selected based on their health history and the possible benefits of cognitive enrichment in improving health measures. To evaluate this, information regarding the animals' consumption of their offered diet was compared to other animals in the population of similar age and the absence of a similar health history. Subsequently, the total diet consumption of the targeted animals was evaluated in the two years prior to the introduction to EVE and compared to the total diet consumption during the initial 2 years of regular EVE sessions. There was a significant decrease in the number of days in which the sea lions did not consume their entire offered diet in the two years after implementing regular EVE sessions, an increase in participation and performance of voluntary husbandry behaviors, and a reduction in the number of days animals were clinically ill. This study provides evidence of cognitive enrichment as a management tool to improve animal health and welfare as well as performance in training sessions.

Accretion Disk Size and Updated Time-delay Measurements in the Gravitationally Lensed Quasar SDSS J165043.44+425149.3

We analyze variability in 15-season optical lightcurves from the doubly imaged lensed quasar SDSS J165043.44+425149.3 (SDSS1650), comprising five seasons of monitoring data from the Maidanak Observatory (277 nights in total, including the two seasons of data previously presented in Vuissoz et al.), five seasons of overlapping data from the Mercator telescope (269 nights), and 12 seasons of monitoring data from the US Naval Observatory, Flagstaff Station at lower cadence (80 nights). We update the 2007 time-delay measurement for SDSS1650 with these new data, finding a time delay of ΔtAB=−55.1−3.7+4.0 days, with image A leading image B. We analyze the microlensing variability in these lightcurves using a Bayesian Monte Carlo technique to yield measurements of the size of the accretion disk at λ rest = 2420 Å, finding a half-light radius of log(r 1/2/cm) = 16.19−0.58+0.38 assuming a 60° inclination angle. This result is unchanged if we model 30% flux contamination from the broad-line region. We use the width of the Mg ii line in the existing Sloan Digital Sky Survey spectra to estimate the mass of this system’s supermassive black hole, finding M BH = 2.47 × 109 M ⊙. We confirm that the accretion disk size in this system, whose black hole mass is on the very high end of the M BH scale, is fully consistent with the existing quasar accretion disk size–black hole mass relation.

Diving Medicine: An Exciting Journey Through Time and Future Prospects.

Humans, led by their eternal wish to explore the unknown, have always wanted to perfect their diving skills and conquer the sea world. The adverse conditions experienced by divers brought about medical problems and a new field of medicine. Diving medicine serves the identification, treatment, and precautions against illnesses that are related to diving activities. While the development of diving equipment is advancing, divers have had the chance to reach greater depths for a longer time. Along with this success, a novel medical condition under the term 'decompression illness' (DCI) was introduced. Although the history of hyperbaric medicine is very long, progress in the field of mechanics has offered great contributions to the management of the disease. The first attempt at DCI guidelines was made by the US Navy in 1944-1945 and resulted in the creation of hyperbaric treatment tables. These tools received international recognition, offering a major advance. Hyperbaric-Diving Medicine holds an important place in modern medical science nowadays with indications for various diseases. At the same time, there is great scientific interest and a lot of research in the use of hyperbaric oxygen for several medical disorders, demonstrating great potential.

Interfacility Transfer Teams: A Pilot Study to Assess Viability as a Skill Sustainment Platform.

A US Naval hospital in the remote Pacific region has developed interfacility transfer (IFT) teams staffed by active duty personnel out of necessity due to a large percentage of critically ill patients requiring IFT and a lack of local resources. The IFT program underwent significant improvements in training and quality assurance in 2017. We sought to assess patient safety when transport was performed by our locally sourced and trained IFT teams. En route care (ERC) is a recognized critical capability gap in the US Navy requiring clinicians with current knowledge and skills to maintain competency. IFT programs may be a viable skill sustainment program for ERC clinicians. A database was created as part of the quality assurance program to collate information on patient demographics, level of care provided, reason for transport, and interventions provided by the transporting team. A retrospective review of these data was conducted with emphasis on the appropriateness of patient management and skill sustainment for active duty personnel. The project was deemed institutional review board exempt. Of the 1,193 patient care reports reviewed, interventions were required in 128 (10.7%) of patients and 58 (4.9%) required ventilator management. Medical deterioration occurred during 22 (1.8%) of the transports, with 20 (90.9%) of the deterioration episodes managed appropriately. No patient harm occurred. IFT teams with local training were able to safely transport critically ill patients with no adverse outcomes, defined as direct harm to the patients as a result of transport. Patient care during transports included routine interventions, ventilator management, and troubleshooting of patient deteriorations. Our data further suggest IFT programs may be a viable skill sustainment platform for ERC clinicians.

Capturing wartime history to forge postwar intelligence liaison: Telford Taylor’s battle with the US Navy over the future of Anglo-American signals intelligence

ABSTRACT Telford Taylor was not a career military intelligence officer, but his short career in military intelligence during World War Two had an outsized impact on the development of American interservice as well as Anglo-American signals intelligence. Near the end of the war, Taylor put forth a visionary proposal to harness wartime lessons learned against Germany and Japan in order to prepare for postwar collaboration against likely rivals, particularly the Soviets. While his British interlocutors were amenable to such a project, the US Navy was not.

The Most Significant Technical Challenges for the US Naval Forces at the South China Sea

The United States of America’s Naval Forces constantly prepare for operations againstpotential adversaries, most notably the military threat posed by the People’s Republicof China. Chinese developments over the past decades have successfully reduced thetechnological and procedural gap compared with the US Navy in some areas, and insome cases they have already demonstrated certain advantages. In my study, I willexamine the US response to these challenges in the recent past, with regard to theNavy and the Marine Corps.

Analyzing daily sorties at NAS Kingsville utilizing alternative refueling methods

Training Air Wing TWO (TW-2) is responsible for the intermediate and advanced phases of Undergraduate Jet Pilot Training and provides the US Navy and Marine Corps with newly winged aviators. The objective of this study is to improve daily operations at TW-2 using sortie output and aircraft refuel waiting time as measures of performance. We define a sortie as any flight event attempted on the daily flight schedule to facilitate student training. We create a discrete-event simulation to model daily jet flow and operations at TW-2. We compare current operations with several alternative refueling strategies that incorporate hot pit refueling to minimize the time jets spend on the ground between consecutive sorties. We consider different factors and run a variety of experiments to determine the impact of various fueling strategies on resource utilization rates in an effort to generate more sorties. Our analysis finds that TW-2 can increase daily sortie throughput by an average of 60 sorties by incorporating both hot pit and cold refueling. We recommend using two hot pits to decrease the yearly idle fuel-burn cost by over $342,000 and reclaim a value of $98,422,500 from the annual maintenance contract at TW-2.

Balancing the necessary and the possible

The US Navy should hedge by retaining conventional warships and concepts of operations while at the same time developing next-generation formations.

Moderate Anthropogenic Noise Exposure Does Not Affect Navy Bottlenose Dolphin (Tursiops truncatus) Whistle Rates

Bottlenose dolphins (Tursiops truncatus) rely on frequency- and amplitude-modulated whistles to communicate, and noise exposure can inhibit the success of acoustic communication through masking or causing behavioral changes in the animal. At the US Navy Marine Mammal Program (MMP) in San Diego, CA, dolphins are housed in netted enclosures in the San Diego Bay and exposed to noise from vessels, unmanned underwater vehicles, and other remote sensing devices. The acoustic behavior of 20 dolphins was monitored and whistle rates during noise events were quantified. Whistle rates during the onset of the event (i.e., the first 5 min) did not significantly differ from the pre-onset (5 min immediately preceding). Whistle rates were also not significantly different for the entire duration of the event compared to a matched control period. The noise’s frequency range (i.e., control, mid-frequency (0–20 kHz) or high-frequency (21–80 kHz)), signal-to-noise ratio, and sound pressure level were not significantly related to the dolphins’ whistle rate. Considering this is a location of frequent and moderate noise output, these results lend support to established guidelines on anthropogenic noise exposure for cetaceans, suggesting that moderate noise exposure levels may not impact communication efforts in bottlenose dolphins.

Cryotherapy-Induced Iatrogenic Frostbite on Distal Digit: Case Report and Review of Management Strategies.

Cryotherapy is a widely utilized topical treatment for various dermatological conditions. While generally safe and effective, it carries potential risks, such as frostbite injury. Frostbite, a vascular condition causing skin and tissue freezing, is usually associated with prolonged exposure to freezing environments. Certain populations, like military personnel navigating frigid terrains, face an increased risk of frostbite and other cold-weather injuries. In this case, we present an unusual instance of iatrogenic frostbite in a 23-year-old active duty United States Navy Sailor. The patient required a diverse range of treatment modalities, including pain management, sildenafil, nitroglycerine paste, and hyperbaric oxygen therapy. The implemented treatment regimen resulted in significant clinical improvements with minimal long-term structural damage. This case underscores the clinical value of establishing clear management guidelines for cryotherapy administration in cutaneous conditions. Such guidelines are essential to ensure optimal dosing, minimize adverse sequelae, and improve overall prognosis.

Analysis of Japanese Defeats at The Battle of Midway in 1942

Analysis of Japanese Defeats at The Battle of Midway in 1942

Strengthening Naval Diplomacy RI-US in Intelligence, Surveillance, Reconnaissance through Cooperation Afloat Readiness and Training 2024

This research discusses the joint exercise between the Indonesian Navy, the US Navy, and the US Marines (USMC), namely Cooperation Afloat Readiness and Training (CARAT) to carry out Intelligence, Surveillance, and Reconnaissance (ISR), littoral warfare, and coastal defence missions. This research uses descriptive qualitative related to Cooperation Afloat Readiness and Training (CARAT). CARAT is implemented bilaterally to enhance the maritime partnership between Indonesia and the US. For Indonesia, building a maritime partnership with the US should focus on bilateral interests as well as regional security. For the US, the CARAT programme in Indonesia can be seen as part of an effort to strengthen its influence in Southeast Asia, including facing China's dominance in the region. Based on the above background, the researcher formulates the problem, namely how to strengthen Indonesia's cooperative relationship with the United States in the face of China's dominance in the Southeast Asian region. Data collection is obtained from literature review by collecting various articles, books, journals, or other sources.   The results of this study indicate that to strengthen Indonesia's cooperative relationship with the United States in the face of China's dominance in the Southeast Asian region, is to increase cooperation in the field of security and defence, through Cooperation Afloat Readiness and Training 2024. This will help strengthen Indonesia's defence capacity and also send a signal to China that Indonesia is not easily intimidated. It is also important to continue to build relations with China in a critical but constructive manner, by promoting dialogue and diplomacy to seek points of agreement and achieve stability in the Southeast Asian region as a whole. CARAT activities are an effective strategy in enhancing security stability in the region through maritime defence cooperation. The programme benefits partner countries in building relationships of trust, enhancing defence capabilities and combating maritime threats. To increase the effectiveness of CARAT, it is recommended that partner countries continue to be committed to the programme and maintain good cooperation with the US navy and other countries in the region.

GPS-free roll and pitch estimation through pressure altitude aided inertial navigation system for a jet aircraft

This paper presents a novel approach for estimating roll and pitch angles of an aircraft by regulating the dead-reckoning drift using pressure altitude measurements. The proposed algorithm uses measurements from rate gyroscopes, pressure altitude, and an air data system to estimate the roll and pitch angles of an aircraft. This unique combination of sensor data offers a new alternative to traditional navigation approaches relying on accelerometers and satellite systems to estimate the aircraft attitude. Multiple flight data sets from a high-speed crewed US Navy T-38 jet are used to validate the proposed approach. Comparable levels of attitude estimation accuracy are reported thus demonstrating that the proposed algorithm is a viable alternative for attitude estimation purposes. Therefore, this approach can be used to improve the robustness and accuracy of attitude estimation algorithms in scenarios where GPS coverage is denied, unreliable, spoofed and/or jammed.

Book Reviews: Hard Aground: The Wreck of the USS Tennessee and the Rise of the US Navy by Andrew C. A. Jampoler

Book Reviews: <i>Hard Aground: The Wreck of the USS Tennessee and the Rise of the US Navy</i> by Andrew C. A. Jampoler

Wargaming for Learning: How Educational Gaming Supports Student Learning and Perspectives

To what extent does educational gaming add value to more traditional instructional models in learning core concepts of national security and warfighting? This paper presents the results from a quasi-experimental, cross-sectional, and longitudinal study of students taking two standardized courses in the Joint Military Operations department at the US Naval War College. Split into wargaming and non-wargaming sections by instructor preference, subject learning is measured through self-reported and objective measures at three points: prior to the start of the content block on “Operational Art”; after the case study of the WW2 battle of Leyte Gulf but prior to any wargaming; and for subjects in wargaming course sections, after participating in the Leyte Gulf scenario of the “War at Sea” wargame. The results support the hypotheses that wargaming increases learning and alter student preferences in favor of learning through gaming but fail to find evidence that students recognize the value of the debriefing phase of educational gaming. This article adds to existing studies by focusing on an understudied practitioner population—graduate-level career military officers at a professional military education (PME) institution—and mitigating several of the methodological challenges facing many scholarly projects in the study of educational gaming in political science.

Distribution, abundance, and density of harbor porpoises in Hood Canal, Washington

AbstractHarbor porpoises (Phocoena phocoena) are the only cetaceans routinely sighted in Hood Canal, a narrow fjord that comprises the western edge of Puget Sound, Washington, USA. Harbor porpoises are sensitive to anthropogenic sounds, including noise from recreational and commercial vessel traffic, and the United States Navy, which conducts military training and testing within Hood Canal that can include underwater sound sources. This study was funded as part of the Navy monitoring program to assess potential impacts of naval activities on cetaceans. We conducted vessel‐based line‐transect surveys for harbor porpoises in Hood Canal in 2022–2023 to derive seasonal estimates of abundance and density. We carried out surveys over 37 days and surveyed the entire canal twice per season totaling 2,176 km of on‐effort track line. We recorded 809 on‐effort harbor porpoise groups and 1,385 individuals. Seasonal abundance estimates were lowest in winter (308 animals, 95% CI = 189–503) and gradually increased through spring and summer to a peak of 1,336 animals (95% CI = 826–2,160) in fall. Overall porpoise density was highest in central Hood Canal, an area that includes a designated United States Navy training range, though porpoise sightings were notably absent in a 21‐km2 area adjacent to the naval submarine base within this otherwise high‐density region. Though we collected only a single year of data, these results suggest that harbor porpoise abundance in Hood Canal increased significantly since it was last estimated (2013–2015). The notable seasonal fluctuation of harbor porpoise abundance suggests Hood Canal may host a larger percentage of the overall Washington Inland Waters stock during the fall season, raising important management considerations.