Air Education and Training Command
governmentFort Sam Houston Joint Base San Antonio, Texas, United States
Research output, citation impact, and the most-cited recent papers from Air Education and Training Command (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Air Education and Training Command
In Brief Background: Effective combat trauma management strategies depend upon an understanding of the epidemiology of death on the battlefield. Methods: A panel of military medical experts reviewed photographs and autopsy and treatment records for all Special Operations Forces (SOF) who died between October 2001 and November 2004 (n = 82). Fatal wounds were classified as nonsurvivable or potentially survivable. Training and equipment available at the time of injury were taken into consideration. A structured analysis was conducted to identify equipment, training, or research requirements for improved future outcomes. Results: Five (6%) of 82 casualties had died in an aircraft crash, and their bodies were lost at sea; autopsies had been performed on all other 77 soldiers. Nineteen deaths, including the deaths at sea were noncombat; all others were combat related. Deaths were caused by explosions (43%), gunshot wounds (28%), aircraft accidents (23%), and blunt trauma (6%). Seventy of 82 deaths (85%) were classified as nonsurvivable; 12 deaths (15%) were classified as potentially survivable. Of those with potentially survivable injuries, 16 causes of death were identified: 8 (50%) truncal hemorrhage, 3 (19%) compressible hemorrhage, 2 (13%) hemorrhage amenable to tourniquet, and 1 (6%) each from tension pneumothorax, airway obstruction, and sepsis. The population with nonsurvivable injuries was more severely injured than the population with potentially survivable injuries. Structured analysis identified improved methods of truncal hemorrhage control as a principal research requirement. Conclusions: The majority of deaths on the modern battlefield are nonsurvivable. Improved methods of intravenous or intracavitary, noncompressible hemostasis combined with rapid evacuation to surgery may increase survival. Effective combat trauma management strategies depend on an understanding of the epidemiology of death on the battlefield. A review of photographs and autopsy and treatment records of 82 combat deaths classified the majority as nonsurvivable. Twelve (15%) deaths identified as potentially survivable led us to conclude that improved methods of intravenous or intracavitary, noncompressible hemostasis, and rapid evacuation may increase survival.
A potential emerging problem associated with increasingly popularized extreme conditioning programs (ECPs) has been identified by the military and civilian communities. That is, there is an apparent disproportionate musculoskeletal injury risk from these demanding programs, particularly for novice participants, resulting in lost duty time, medical treatment, and extensive rehabilitation. This is a significant and costly concern for the military with regard to effectively maintaining operational readiness of the Force. While there are certain recognized positive aspects of ECPs that address a perceived and/or actual unfulfilled conditioning need for many individuals and military units, these programs have limitations and should be considered carefully. Moreover, certain distinctive characteristics of ECPs appear to violate recognized accepted standards for safely and appropriately developing muscular fitness and are not uniformly aligned with established and accepted training doctrine. Accordingly, practical solutions to improve ECP prescription and implementation and reduce injury risk are of paramount importance.
OBJECTIVE: Evaluate the effect of a community-based, experiential cooking and nutrition education program on consumption of fruits and vegetables and associated intermediate outcomes in students from low-income families. DESIGN: Quasi-experimental program evaluation by pre-post survey of participating students and their parents. SETTING: Underserved elementary and middle schools in Chicago. PARTICIPANTS: Students (n = 271; 65% girls, 44% Hispanic, 32% African American; 94% eligible for free/reduced price lunch) in grades 3-8 selected by school staff to participate by variable inclusion criteria. 59% of students who applied returned both pre- and post-surveys. INTERVENTION(S): Ten-week (2 h/wk) chef-instructor-led program held in cafeteria kitchens after school. MAIN OUTCOME MEASURE(S): Changes in student nutrition knowledge, cooking self-efficacy, fruit and vegetable liking and consumption, and communication to family about healthy eating. ANALYSIS: Changes from beginning to end of program were analyzed with paired t test. Results were considered significant at P < .05. RESULTS: Increased nutrition knowledge score from 0.6 to 0.8, cooking self-efficacy score from 3.2 to 3.6, and vegetable consumption score from 2.2 to 2.4 (all P < .05). Increased score for communication about healthy eating (4.1 to 4.4; P < .05) 6 months after the end of the course. CONCLUSIONS AND IMPLICATIONS: Experiential cooking and nutrition education programs led by chef-instructors may be effective ways to improve nutrition in low-income communities.
Methods of using diversity to improve frequencyshift keyed receptions in the presence of Rayleigh fading are analyzed. In the absence of prior information about signal amplitude and phase, square-law combination is optimum; the error rate for this combination method has been found. If signal amplitude and phase are exactly known prior to reception of the signal, coherent combination and detection are optimum; at low error probability this yields only a 3-db improvement. Nonoptimum switch diversity yields only slightly less diversity gain than square-law combination. For dual diversity, correlation of the fading on the separate antennas does not give a large loss if the correlation coefficient is moderate. Correlated noise yields a similar small loss.
Abstract Disproportionately large numbers of threatened and endangered species and unusually high biodiversity occur on active and former military training areas. Although this may seem paradoxical given the apparently destructive nature of military training, an evaluation of the nature and extent of the disturbances is enlightening. Military training frequently produces heterogeneous landscapes. Large portions of military training areas remain virtually untouched, favoring disturbance‐averse species; other portions are heavily disturbed, favoring disturbance‐dependent species. The rich habitat mosaics include the two extremes as well as the continua of disturbance and succession between them, thus providing suitable habitat for a very large number of species with widely varying habitat requirements. To explain the phenomenon, a heterogeneous disturbance hypothesis is proposed which suggests that biodiversity is maximized where multiple kinds, frequencies, severities, periodicities, sizes, shapes, and/or durations of disturbance occur concomitantly on a landscape in a spatially and temporally distributed fashion. The enhanced biodiversity occurring on active and former military training areas illustrates the need for restoration ecologists to restore or maintain an appropriate heterogeneous disturbance regime when attempting to restore ecosystem function and biodiversity.
Ontologies are entering widespread use in many areas such as knowledge and content management, electronic commerce and the Semantic Web. In this paper we show how the use of ontologies has helped us overcome some important problems in the development of pervasive computing environments. We have integrated ontologies and Semantic Web technology into our pervasive computing infrastructure. Our investigations have shown that Semantic Web technology can be integrated into our CORBA-based infrastructure to augment several important services. This work suggests a number of requirements for future research in the development of ontologies, reasoners, languages and interfaces.
Screening weapon systems development projects is a complex, multicriteria decision problem that must be accomplished within a constrained resource environment. This paper presents a hybrid decision support methodology for use in the screening of weapon systems development projects. The hybrid methodology integrates the analytic hierarchy process (AHP) with a 0-1 integer portfolio optimization model. An AHP component allows the decision maker to incorporate qualitative and intangible criteria into the decision-making process and use the priority rankings of the AHP to represent a measure of value in the 0-1 integer model objective function. The hybrid methodology is extremely flexible and the decision maker can tailor both the AHP and the 0-1 integer optimization model to represent a specific decision-making situation. To fully appreciate the added value of implementing the hybrid screening methodology, a group of Air Force decision makers applied the hybrid methodology to a realistic weapon-systems project screening activity. Results indicate that decision support provided by the methodology could lead to substantial improvements in a weapon-systems portfolio value.
Prevention of musculoskeletal injuries (MSKI) is critical in both civilian and military populations to enhance physical performance, optimize health, and minimize health care expenses. Developing a more unified approach through addressing identified movement impairments could result in improved dynamic balance, trunk stability, and functional movement quality while potentially minimizing the risk of incurring such injuries. Although the evidence supporting the utility of injury prediction and return-to-activity readiness screening tools is encouraging, considerable additional research is needed regarding improving sensitivity, specificity, and outcomes, and especially the implementation challenges and barriers in a military setting. If selected current functional movement assessments can be administered in an efficient and cost-effective manner, utilization of the existing tools may be a beneficial first step in decreasing the burden of MSKI, with a subsequent focus on secondary and tertiary prevention via further assessments on those with prior injury history.
Abstract Symmetric and unsymmetric double cantilever beam (DCB) specimens were tested and analyzed to assess the effect of (1) adherend thickness and (2) a predominantly mode I mixed mode loading on cyclic debond growth and static fracture toughness. The specimens were made of unidirectional composite (T300/5208) adherends bonded together with EC3445 structural adhesive. The thickness was 8, 16 or 24 plies. The experimental results indicated that the static fracture toughness increases and the cyclic debond growth rate decreases with increasing adherend thickness. This behavior was related to the length of the plastic zone ahead of the debond tip. For the symmetric DCB specimens, it was further found that displacement control tests resulted in higher debond growth rates than did load control tests. While the symmetric DCB tests always resulted in cohesive failures in the bondline, the unsymmetric DCB tests resulted in the debond growing into the thinner adherend and the damage progressing as delamination in that adherend. This behavior resulted in much lower fracture toughness and damage growth rates than found in the symmetric DCB tests.
The NASA two stage fan was tested with a low aspect ratio first stage rotor having no midspan dampers. At design speed the fan achieved an adiabatic design efficiency of 0.846, and peak efficiencies for the first stage and rotor of 0.870 and 0.906, respectively. Peak efficiency occurred very close to the stall line. In an attempt to improve stall margin, the fan was retested with circumferentially grooved casing treatment and with a series of stator blade resets. Results showed no improvement in stall margin with casing treatment but increased to 8 percent with stator blade reset.
Anthroponotic cutaneous leishmaniasis (CL) is a common cause of ulcerative lesions and disfiguring scarring among children in Afghanistan. Most lesions occur on the face and are commonly caused by the trypanosome protozoan parasite Leishmania tropica, transmitted by the bite of an infected sandfly (Phlebotomus sergenti). This study compared the effectiveness of a single localized treatment with thermotherapy to 5 days of intralesional administration of Glucantime for the treatment of CL. Three hundred and eighty-two patients with CL were randomly assigned to the two treatment groups and followed for 6 months. The cure rate for the thermotherapy group was 82.5%, compared to 74% in the Glucantime group. The authors concluded that a single localized treatment with thermotherapy was more effective than 5 days of intralesional administration of Glucantime. Additionally, thermotherapy was more cost-effective, with fewer side effects, of shorter duration, and with better patient compliance than intralesional Glucantime.
Lubrication of microelectromechanical systems (MEMS) became very critical as the devices became complex and its reliability began to deteriorate. In this paper, ionic liquids (ILs) with low volatility and high environmental stability were investigated as lubricants for sliding MEMS devices. A method that is based on atomic force microscopy (AFM) with a liquid cell was developed to study friction and wear properties of surfaces lubricated with ILs, having a systematic variation in molecular geometry and chemistry. Six-member pyridinium and five-member imidazolium rings are compared as cations in ethyl methyl pyridinium and ethyl methyl imidazolium ethyl sulfate; influence of short and long alkyl chain lengths on lubrication is studied with butyl methyl pyrrolidinium and hexyl methyl pyrrolidinium bis(trifluro methyl sulfonyl) imide. Formation of a surface-screening cation layer was discovered and linked to low friction and wear of IL-lubricated hydrogenated-silicon (H-Si) substrates. Several promising IL lubricants were identified from the AFM study and were tested in real MEMS motor devices. The friction and wear data obtained for these tests showed good correlation with the failure life span of lubricated MEMS motors. This supports a conclusion that the AFM-liquid-cell technique can be used in screening IL lubricants for MEMS devices.
Cet article montre comment l’approche en termes de dimensions négatives de la proximité contribue à la compréhension des processus conflictuels caractéristiques des espaces ruraux et périurbains. Notre démarche repose sur des recherches empiriques menées sur différents terrains, qui nous ont permis d’élaborer des faits stylisés, et se fonde également sur les grandes catégories de l’analyse des proximités. Elle a pour objectif de contribuer à l’identification et à la catégorisation de ces conflits. Le texte aborde tout d’abord l’analyse des conflits liés à l’espace, en comparant différentes approches qui traitent des relations de voisinage puis en proposant une définition générique des conflits et des conflits d’usage et de voisinage. Dans un second temps, nous examinons la question du lien entre processus conflictuels et relations de proximité, en commençant par montrer comment l’approche en termes de proximité permet de comprendre et de classer les différents types de relations à l’œuvre dans les relations conflictuelles, puis en présentant enfin une série d’illustrations, issues de nos travaux empiriques, des catégories présentées auparavant.
Quality circle (QC) programs instituted in two Department of Defense (DOD) organizations were evaluated within the framework of a nonequivalent control group design. Two waves of survey data were collected from 107 members of a military maintenance organization and 165 employees of a medical facility located on the same DOD installation. Analysis of covariance procedures on data from the maintenance sample isolated significant treatment group effects on 7 of the 20 criterion variables used in the study. However, QC treatment effects were not apparent in the covariance results for the hospital personnel. Subgroup analyses on the data provided by active QC members identified different patterns of responses from individuals in the two samples. Active circle members from the maintenance organization tended to evaluate their situation more favorably as the study progressed. In contrast, responses provided by active QC group members from the medical facility tended to take an increasingly more negative tone over the course of the study. Qualitative differences between the two organizations in the conduct of the QC intervention are reviewed in an effort to identify potential moderating variables conditioning the degree of program success.
OBJECTIVE: To estimate West Nile virus (WNV) infection rates, assess environmental variables that correlated with seropositivity in dogs and cats, and assess whether pets should be considered as possible sentinels for WNV and therefore of potential human exposure. DESIGN: Cross-sectional serosurvey. ANIMALS: 442 dogs and 138 cats. PROCEDURE: Serum samples were screened for seropositivity against WNV by use of the plaque reduction neutralization test. RESULTS: 116 (26%) dogs and 13 (9%) cats yielded positive results. The odds of seropositivity against WNV for outdoor-only family dogs were almost 19 times as great as those for indoor-only family dogs and almost twice as great for stray dogs as for family dogs. Family dogs not receiving heartworm medication were 2.5 times as likely to yield positive results for antibodies against WNV as family dogs receiving heartworm medication. CONCLUSIONS AND CLINICAL RELEVANCE: Seropositivity was greater for outdoor family dogs than for indoor family dogs. Further investigation of the potential use of stray dogs as sentinel indicators for WNV infection and the potential risk of human exposure is warranted.
There continues to be increasing interest from a broad range of disciplines in agent-based and artificial life simulations. This includes the Department of Defense - which uses simulations heavily in its decision making process. Indeed, military conflicts can have many attributes that are consistent with complex adaptive systems - such as many entities interacting with some degree of autonomy, each of which is continually making decisions to satisfy a variety of sometimes conflicting objectives. In this paper, we present three applications of agent-based simulations used to analyze military problems. The first uses the MANA model to explore the ability of the U.S. Army's network-based Future Force to perform with degraded communications. The second studies how unmanned surface vehicles can be used in force protection missions with the Pythagoras model. The last example examines the standard Army squad size with an integrated effort using MANA, Pythagoras, and the high-resolution simulation JANUS.
In mid-May 2007, a respiratory disease outbreak associated with adenovirus, serotype B14 (Ad14), was recognized at a large military basic training facility in Texas. The affected population was highly mobile; after the 6-week basic training course, trainees immediately dispersed to advanced training sites worldwide. Accordingly, enhanced surveillance and control efforts were instituted at sites receiving the most trainees. Specimens from patients with pneumonia or febrile respiratory illness were tested for respiratory pathogens by using cultures and reverse transcription-PCR. During May through October 2007, a total of 959 specimens were collected from 21 sites; 43.1% were adenovirus positive; the Ad14 serotype accounted for 95.3% of adenovirus isolates. Ad14 was identified at 8 sites in California, Florida, Mississippi, Texas, and South Korea. Ad14 spread readily to secondary sites after the initial outbreak. Military and civilian planners must consider how best to control the spread of infectious respiratory diseases in highly mobile populations traveling between diverse geographic locations.
BACKGROUND: In this meta-analysis, we compared the risk of obtaining nondiagnostic results and the diagnostic accuracy for detection of salivary gland malignancy between core needle biopsy (CNB) and fine-needle aspiration (FNA). METHODS: All published English-language studies comparing CNB and FNA diagnostic accuracy for salivary gland masses through December 2019 were searched. Pooled risk ratios (RRs) of nondiagnostic results, sensitivities, and specificities of CNB and FNA for salivary gland malignancy diagnosis were determined. Complication rates were compared. RESULTS: Six studies (1924 procedures) were quantitatively analyzed. CNB yielded significantly fewer nondiagnostic results (P < .001) and had significantly higher pooled sensitivity (P < .001) and specificity (P = .002) than FNA for differentiating malignant and benign salivary gland neoplasms. Hematoma occurred in 0.3% of CNB, while no complication occurred in FNA procedures. CONCLUSION: CNB yielded fewer nondiagnostic results and had superior diagnostic performance compared with FNA for detecting salivary gland malignancies.
Tumor diameter has traditionally been used as a standard metric in terms of diagnosis and prognosis prediction of lung cancer. However, recent advances in imaging techniques and data analyses have enabled novel quantitative imaging biomarkers that can characterize disease status more comprehensively and/or predict tumor behavior more precisely. The most widely used imaging modality for lung tumor assessment is computed tomography. Therefore, we focused on computed tomography imaging biomarkers such as tumor volume and mass, ground-glass opacities, perfusion parameters, as well as texture features in this review. Herein, we first appraised the conventional 1- or 2-dimensional measurement with brief discussion on their limits and then introduced the potential imaging biomarkers with emphasis on the current understanding of their clinical usefulness with respect to the malignancy differentiation, treatment response monitoring, and patient outcome prediction.
The assumption that the palatal (PAL) root of maxillary molars has significantly greater attachment area than either the mesiobuccal (MB) or the distobuccal (DB) root was tested by documenting the root surface area of the individual roots and root trunks of 20 extracted maxillary first molars. Each molar was cross sectioned every millimeter, and the circumference of each root and root trunk section was measured with a calibrated opisometer. Mean circumferential measurements from each 1-mm section were summed to give the surface area for each root and root trunk. The DB root had significantly less surface area than either the MB or PAL root or the root trunk. There was no significant difference between the surface areas of the MB and PAL roots. The surface area of the root trunk, which was significantly greater than that of any of the three individual roots, averaged 32% of the total root surface area of the maxillary first molar.