Point of impact : delivering mission essential supplies to the warfighter through the Joint Precision Airdrop System (JPADS)

Thesis (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 107-111).The Joint Precision Airdrop System (JPADS) exists to execute logistical resupply operations using fixed and rotary wing air in a safe, effective and precise manner in order to deliver supplies and equipment to intended recipients at multiple locations on a single mission in hostile or restricted terrain. In the U.S. Military's Current Operating Environment (COE) in locations all over the world, Soldiers find themselves operating in areas that are either too arduous to move to by ground or where the threat is elevated to the point where the unit must maneuver to a particular location by air in order to increase unit survivability, maintain the element of surprise and execute timely operations. Current and previous logistical resupply platforms and systems fail to meet these requirements due to inaccuracies and ineffectiveness, increased enemy capabilities to effect friendly supply lines and increased threats to low flying aircraft, which has an immediate impact on mission accomplishment. Current force structure requires a system that can operate in a dynamic and mercurial environment in order to rapidly adjust to changes on the ground, which is a necessity. The objective of this research thesis is to provide a thorough analysis of the JPADS through a rich stakeholder analysis of the system and a complete study of the JPADS system architecture. This will allow further investigation using the Design Structure Matrix (DSM), which is a system engineering methodology and tool utilized to provide improvement recommendations to project sponsors working on the system. This research thesis will argue that there are two critical components vital to the success of the JPADS, which include an integrated Wind Data Sensor that can provide real-time wind updates to the JPADS and a Terrain Avoidance Feature to ensure success in challenging terrain such as we find our military currently operating in. Instrumental to the success of the JPADS is developing a system that takes full advantage of tip of the spear technology through a modular system capable of adapting to both the environment and the mission. This research thesis will apply systems architecture and DSM analysis to the JPADS in order to fully analyze the system and illustrate why the incorporation of both the Wind Data Sensor and the Terrain Avoidance Feature is a necessity to ensure operational success of the system.by Joshua A. N. Eaton.S.M.in Engineering and Managemen

The Rotation Period of the Planet-Hosting Star HD 189733

We present synoptic optical photometry of HD 189733, the chromospherically active parent star of one of the most intensively studied exoplanets. We have significantly extended the timespan of our previously reported observations and refined the estimate of the stellar rotation period by more than an order of magnitude: $P = 11.953\pm 0.009$ days. We derive a lower limit on the inclination of the stellar rotation axis of 56\arcdeg (with 95% confidence), corroborating earlier evidence that the stellar spin axis and planetary orbital axis are well aligned.Comment: To appear in A

Biomechanical, ultrastructural, and electrophysiological characterization of the non-human primate experimental glaucoma model.

Laser-induced experimental glaucoma (ExGl) in non-human primates (NHPs) is a common animal model for ocular drug development. While many features of human hypertensive glaucoma are replicated in this model, structural and functional changes in the unlasered portions of trabecular meshwork (TM) of laser-treated primate eyes are understudied. We studied NHPs with ExGl of several years duration. As expected, ExGl eyes exhibited selective reductions of the retinal nerve fiber layer that correlate with electrophysiologic measures documenting a link between morphologic and elctrophysiologic endpoints. Softening of unlasered TM in ExGl eyes compared to untreated controls was observed. The degree of TM softening was consistent, regardless of pre-mortem clinical findings including severity of IOP elevation, retinal nerve fiber layer thinning, or electrodiagnostic findings. Importantly, this softening is contrary to TM stiffening reported in glaucomatous human eyes. Furthermore, microscopic analysis of unlasered TM from eyes with ExGl demonstrated TM thinning with collapse of Schlemm's canal; and proteomic analysis confirmed downregulation of metabolic and structural proteins. These data demonstrate unexpected and compensatory changes involving the TM in the NHP model of ExGl. The data suggest that compensatory mechanisms exist in normal animals and respond to elevated IOP through softening of the meshwork to increase outflow

The Relationship between Knee Valgus and Clinical Measures in Professional Basketball: A CART Analysis

Background/Purpose: Lower extremity injuries occur at an amplified rate in professional basketball. Evidence suggests that knee frontal plane valgus may be associated with risk of injury. The Landing Error Scoring System includes the assessment of maximum knee valgus during a countermovement jump. The investigation of interactions among linear and non-linear factors may help the understanding of the interdependence of various measures and poor performance on the knee valgus displacement (KVD) component of the LESS in professional basketball players. The purpose of this study was to investigate predictors of knee valgus displacement on the LESS. We hypothesize that a positive finding on the knee valgus displacement component of the LESS will be predicted by select clinical measures. Methods: 47 professional basketball players participated. Measurements were completed as part of preseason mobility screening prior to the 2015-16 and 2016-17 NBA seasons. Classification and Regression Tree Analysis (CART) were used to investigate linear and non-linear interactions among predictors and their influence on KVD in players who performed the LESS test. Results: Of the 47 players included in this study, 16 players did not test positive for KVD on the LESS test and 31 did. Pruning resulted in 4 splits (r2=0.507) demonstrating that KVD was predicted by total hip rotation range of motion, dominant leg hip external rotation, and standing arch height index measure. Predictive modeling, classified 18 of the 31 players with KVD and 8 of the 16 players who tested negative for KVD. The area under the ROC curve was .9183, suggesting that classification of players using this model was not random. Conclusion: KVD and performance on the LESS has been linked with injury. CART analysis captured linear and non-linear interactions between clinical measures suggesting that lower extremity biomechanical factors may be associated with predicting KVD during performance on the LESS. Clinical Relevance: KVD and the LESS test has been shown to be predictive of injury. Identifying which clinical measures may be linked with poor performance on this test may aide clinicians in determining appropriate interventions that may be associated with improved scores and minimize risk of injury.https://ecommons.udayton.edu/dpt_symposium/1000/thumbnail.jp

The Utility of Functional Movement Assessment on NBA Players

Professional basketball related injuries have not declined over the last decade despite improvements in training and conditioning or medical advancements in diagnostics, surgery, or rehabilitation. A descriptive epidemiological study of 80% of the National Basketball Association (NBA) teams over 17 years reported an injury incidence of 19.1 per 1000 athlete exposures, and 59,179 games missed due to injury. Starkey found that the there has been a 12.4% increase in game-related injuries in the NBA in a 10-year period from the 1988 - 1997 seasons. It is suspected that increased contact within the NBA along with improved player athleticism, size, power, and speed have contribute to the rise in injuries. The most commonly reported injuries in the NBA as reported via the greatest number of days missed include ankle sprains, patellofemoral inflammation, knee sprains, and lumbar strains. Recent trends involve less focus on specific physical or clinical measures and increased attention on the assessment of functional movement patterns for the purpose of predicting the likelihood of injury. The Functional Movement Screen (FMSTM) was introduced as a pre-participation examination intended to evaluate the quality of seven basic movement patterns that require a balance of both mobility and stability. The functional movements tested include: deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, trunk stability push-up, and rotary stability. It is designed to assess the extremes of specific movements and positions for the purpose of identifying potential limitation, compensation, and asymmetry in individuals without obvious pathology. Recent literature has linked this screen to injury prediction in numerous populations that may be predisposed to injury, including professional football players, firefighters, collegiate female athletes, elite track and field athletes, military personnel. The majority of reliability studies conclude that the FMSTM has good intra-rater reliability. While some researchers conclude that reliability increases with additional training and clinical experience, others claim that the FMS intra-rater reliability was not improved with FMS certification. Inter- rater reliability was reported in recent studies to range from moderate and good to high. The Y-balance Test (YBT) is pre-participation assessment used to screen individuals who may have potential for lower extremity injury. This test involves the examination of dynamic balance and postural control. While research is still lacking regarding the validity and utility of the YBT-LQ, the SEBT has been reported to have a moderate to strong effect size and that this test was reliable and valid as a dynamic predictor to lower extremity injuries. No studies have investigated the outcomes of YBT as an injury predictor in professional basketball athletes or the relationship of these factors with functional movement screens.https://ecommons.udayton.edu/dpt_symposium/1011/thumbnail.jp

Antibody targeting of B7-H4 enhances the immune response in urothelial carcinoma.

Patients with locally advanced and metastatic urothelial carcinoma have a low survival rate (median 15.7 months, 13.1-17.8), with only a 23% response rate to monotherapy treatment with anti-PDL1 checkpoint immunotherapy. To identify new therapeutic targets, we profiled the immune regulatory signatures during murine cancer development using the BBN carcinogen and identified an increase in the expression of the T cell inhibitory protein B7-H4 (VTCN1, B7S1, B7X). B7-H4 expression temporally correlated with decreased lymphocyte infiltration. While the increase in B7-H4 expression within the bladder by CD11

Genome-wide Characterization of Shared and Distinct Genetic Components that Influence Blood Lipid Levels in Ethnically Diverse Human Populations

Blood lipid concentrations are heritable risk factors associated with atherosclerosis and cardiovascular diseases. Lipid traits exhibit considerable variation among populations of distinct ancestral origin as well as between individuals within a population. We performed association analyses to identify genetic loci influencing lipid concentrations in African American and Hispanic American women in the Women’s Health Initiative SNP Health Association Resource. We validated one African-specific high-density lipoprotein cholesterol locus at CD36 as well as 14 known lipid loci that have been previously implicated in studies of European populations. Moreover, we demonstrate striking similarities in genetic architecture (loci influencing the trait, direction and magnitude of genetic effects, and proportions of phenotypic variation explained) of lipid traits across populations. In particular, we found that a disproportionate fraction of lipid variation in African Americans and Hispanic Americans can be attributed to genomic loci exhibiting statistical evidence of association in Europeans, even though the precise genes and variants remain unknown. At the same time, we found substantial allelic heterogeneity within shared loci, characterized both by population-specific rare variants and variants shared among multiple populations that occur at disparate frequencies. The allelic heterogeneity emphasizes the importance of including diverse populations in future genetic association studies of complex traits such as lipids; furthermore, the overlap in lipid loci across populations of diverse ancestral origin argues that additional knowledge can be gleaned from multiple populations

HIV Treatment as Prevention: Systematic Comparison of Mathematical Models of the Potential Impact of Antiretroviral Therapy on HIV Incidence in South Africa

Background: Many mathematical models have investigated the impact of expanding access to antiretroviral therapy (ART) on new HIV infections. Comparing results and conclusions across models is challenging because models have addressed slightly different questions and have reported different outcome metrics. This study compares the predictions of several mathematical models simulating the same ART intervention programmes to determine the extent to which models agree about the epidemiological impact of expanded ART. Methods and Findings: Twelve independent mathematical models evaluated a set of standardised ART intervention scenarios in South Africa and reported a common set of outputs. Intervention scenarios systematically varied the CD4 count threshold for treatment eligibility, access to treatment, and programme retention. For a scenario in which 80% of HIV-infected individuals start treatment on average 1 y after their CD4 count drops below 350 cells/µl and 85% remain on treatment after 3 y, the models projected that HIV incidence would be 35% to 54% lower 8 y after the introduction of ART, compared to a counterfactual scenario in which there is no ART. More variation existed in the estimated long-term (38 y) reductions in incidence. The impact of optimistic interventions including immediate ART initiation varied widely across models, maintaining substantial uncertainty about the theoretical prospect for elimination of HIV from the population using ART alone over the next four decades. The number of person-years of ART per infection averted over 8 y ranged between 5.8 and 18.7. Considering the actual scale-up of ART in South Africa, seven models estimated that current HIV incidence is 17% to 32% lower than it would have been in the absence of ART. Differences between model assumptions about CD4 decline and HIV transmissibility over the course of infection explained only a modest amount of the variation in model results. Conclusions: Mathematical models evaluating the impact of ART vary substantially in structure, complexity, and parameter choices, but all suggest that ART, at high levels of access and with high adherence, has the potential to substantially reduce new HIV infections. There was broad agreement regarding the short-term epidemiologic impact of ambitious treatment scale-up, but more variation in longer term projections and in the efficiency with which treatment can reduce new infections. Differences between model predictions could not be explained by differences in model structure or parameterization that were hypothesized to affect intervention impact

Chemically recyclable fluorescent polyesters via the ring-opening copolymerization of epoxides and anhydrides

Polymers rarely possess the desired properties for their intended application; additives (plasticizers, flame-retardants, stabilizers, colourants) modify their physical properties to those needed in the final product. Colourants are particularly detrimental to recycling technologies, since they cannot be removed by reprocessing; reprocessed plastic retains color from the original material. We have prepared single-component, coloured polymers by adding chromophore monomers to epoxide-anhydride ring-opening copolymerization reactions; chromophores need only be added at dopant levels to give highly coloured materials with little change in properties from the base polymer. We have depolymerized the polymers to the parent acid/alcohol and have remade colourless polymer from reformed epoxide and anhydride. Our approach paves the way to using dopant-level monomers to access recyclable polymers with dial-a-property tunability

Exploring pyroelectricity, thermal and photochemical switching in a hybrid organic-inorganic crystal by in situ X-ray diffraction

The switching behavior of the novel hybrid material (FA)Na[Fe(CN)5(NO)].H2O (1) in response to temperature (T), light irradiation and electric field (E) is studied using in situ X-ray diffraction (XRD). Crystals of 1 display piezoelectricity, pyroelectricity, second and third harmonic generation. XRD shows that the FA+ are disordered at room-temperature, but stepwise cooling from 273–100 K induces gradual ordering, while cooling under an applied field (E=+40 kVcm−1) induces a sudden phase change at 140 K. Structural-dynamics calculations suggest the field pushes the system into a region of the structural potential-energy surface that is otherwise inaccessible, demonstrating that application of T and E offers an effective route to manipulating the crystal chemistry of these materials. Photocrystallography also reveals photoinduced linkage isomerism, which coexists with but is not correlated to other switching behaviors. These experiments highlight a new approach to in situ studies of hybrid materials, providing insight into the structure–property relationships that underpin their functionality