Search

This work was supported by the British Heart Foundation (grant ref: FS/20/3/34956). Obesity is a complex disease that increases an individual’s risk of developing other diseases and health-related problems. A common feature is dyslipidemia characterized by increased levels of plasma lipids, which include non-esterified fatty acids (NEFAs). The role of NEFAs in obesity-related morbidity is interesting as NEFAs constitute a reservoir of metabolic energy, are principal components of cell membranes and are precursors for signalling molecules. Bariatric surgery promotes sustained weight loss in severely obese patients, reducing the incidence and severity of co-morbidities. In this study we measure changes in circulating NEFA species in plasma samples taken from 25 obese individuals before and 9 months after Roux-en-Y gastric bypass surgery. The mean weight of the cohort reduced by 29.2% from 149.0±25.1 kg pre-surgery to 105.5±19.8 kg post-surgery and the BMI by 28.2% from 51.8±6.3 kg/m2 pre-surgery to 37.2±5.4 kg/m2. Mean glycated haemoglobin (HbA1c) reduced from 6.5±1.3% to 5.5±0.5%, consistent with the intervention leading to improved glycaemic control, particularly in those who were dysglycemic prior to surgery. Total and LDL cholesterol concentrations were markedly reduced following surgery. Concentrations of seven NEFAs were found to decrease 9 months after surgery compared to pre-surgery levels: myristate, palmitoleate, palmitate, linoleate, oleate, stearate and arachidonate. Bariatric surgery led to increased lipogenesis and elongase activity and decreased stearoyl-CoA desaturase 1 activity. This study thus highlights metabolic changes that take place following gastric bypass surgery in severely obese patients. Publisher PDF

BackgroundPatients with anti-aquaporin-4 antibody seropositive (AQP4-IgG+) neuromyelitis optica spectrum disorders (NMOSDs) frequently suffer from optic neuritis (ON) leading to severe retinal neuroaxonal damage. Further, the relationship of this retinal damage to a primary astrocytopathy in NMOSD is uncertain. Primary astrocytopathy has been suggested to cause ON-independent retinal damage and contribute to changes particularly in the outer plexiform layer (OPL) and outer nuclear layer (ONL), as reported in some earlier studies. However, these were limited in their sample size and contradictory as to the localisation. This study assesses outer retinal layer changes using optical coherence tomography (OCT) in a multicentre cross-sectional cohort.Method197 patients who were AQP4-IgG+ and 32 myelin-oligodendrocyte-glycoprotein antibody seropositive (MOG-IgG+) patients were enrolled in this study along with 75 healthy controls. Participants underwent neurological examination and OCT with central postprocessing conducted at a single site.ResultsNo significant thinning of OPL (25.02±2.03 µm) or ONL (61.63±7.04 µm) were observed in patients who were AQP4-IgG+ compared with patients who were MOG-IgG+ with comparable neuroaxonal damage (OPL: 25.10±2.00 µm; ONL: 64.71±7.87 µm) or healthy controls (OPL: 24.58±1.64 µm; ONL: 63.59±5.78 µm). Eyes of patients who were AQP4-IgG+ (19.84±5.09 µm, p=0.027) and MOG-IgG+ (19.82±4.78 µm, p=0.004) with a history of ON showed parafoveal OPL thinning compared with healthy controls (20.99±5.14 µm); this was not observed elsewhere.ConclusionThe results suggest that outer retinal layer loss is not a consistent component of retinal astrocytic damage in AQP4-IgG+ NMOSD. Longitudinal studies are necessary to determine if OPL and ONL are damaged in late disease due to retrograde trans-synaptic axonal degeneration and whether outer retinal dysfunction occurs despite any measurable structural correlates.

ObjectiveTo identify candidate biomarkers associated with neuromyelitis optica spectrum disorder (NMOSD) using high-throughput technologies that broadly assay the concentrations of serum analytes and frequencies of immune cell subsets.MethodsSera, peripheral blood mononuclear cells (PBMCs), and matched clinical data from participants with NMOSD and healthy controls (HCs) were obtained from the Collaborative International Research in Clinical and Longitudinal Experience Study NMOSD biorepository. Flow cytometry panels were used to measure the frequencies of 39 T-cell, B-cell, regulatory T-cell, monocyte, natural killer (NK) cell, and dendritic cell subsets in unstimulated PBMCs. In parallel, multiplex proteomics assays were used to measure 46 serum cytokines and chemokines in 2 independent NMOSD and HC cohorts. Multivariable regression models were used to assess molecular and cellular profiles in NMOSD compared with HC.ResultsNMOSD samples had a lower frequency of CD16+CD56+ NK cells. Both serum cohorts and multivariable logistic regression revealed increased levels of B-cell activating factor associated with NMOSD. Interleukin 6, CCL22, and CCL3 were also elevated in 1 NMOSD cohort of the 2 analyzed. Multivariable linear regression of serum analyte levels revealed a correlation between CX3CL1 (fractalkine) levels and the number of days since most recent disease relapse.ConclusionsIntegrative analyses of cytokines, chemokines, and immune cells in participants with NMOSD and HCs provide congruence with previously identified biomarkers of NMOSD and highlight CD16+CD56+ NK cells and CX3CL1 as potential novel biomarker candidates.

Additional file 2. Agenda - ACCESS Study-Recruitment material Focus Group.

Additional file 1. Interview Guide - Assessing outcomes of enhanced Chronic disease Care through patient Education and a value-baSed formulary Study (ACCESS).

Additional file 4.

Additional file 5.

Additional file 3.

Additional file 2.

Telephone Baseline Questionnaire. (DOCX 66 kb)

Paper Baseline Survey. (DOCX 612 kb)

Summary of human resources costs. (DOCX 20 kb)

The predominant secretory cargo of bloodstream form Trypanosoma brucei is variant surface glycoprotein (VSG), comprising ~10% total protein and forming a dense protective layer. Blocking VSG translation using Morpholino oligonucleotides triggered a precise pre-cytokinesis arrest. We investigated the effect of blocking VSG synthesis on the secretory pathway. The number of Golgi decreased, particularly in post-mitotic cells, from 3.5 +/- 0.6 to 2.0 +/- 0.04 per cell. Similarly, the number of endoplasmic reticulum exit sites (ERES) in post-mitotic cells dropped from 3.9 +/- 0.6 to 2.7 +/- 0.1 eight hours after blocking VSG synthesis. The secretory pathway was still functional in these stalled cells, as monitored using Cathepsin L. Rates of phospholipid and glycosylphosphatidylinositol-anchor biosynthesis remained relatively unaffected, except for the level of sphingomyelin which increased. However, both endoplasmic reticulum and Golgi morphology became distorted, with the Golgi cisternae becoming significantly dilated, particularly at the trans-face. Membrane accumulation in these structures is possibly caused by reduced budding of nascent vesicles due to the drastic reduction in the total amount of secretory cargo, that is, VSG. These data argue that the total flux of secretory cargo impacts upon the biogenesis and maintenance of secretory structures and organelles in T. brucei, including the ERES and Golgi.

European Commission FP7 Marie Curie Initial Training Network ‘ParaMet’ [290080 to S.S.]; ANR project MetaboHub [ANR-11-INBS-0010 to B.M.]; Wellcome Trust [085349]; The work of Fiona Achcar was part of the SysMO SilicoTryp project coordinated by R.B. Funding for open access charge: European Commission FP7 Marie Curie Initial Training Network ‘ParaMet’ [290080]. The metabolic network of a cell represents the catabolic and anabolic reactions that interconvert small molecules (metabolites) through the activity of enzymes, transporters and non-catalyzed chemical reactions. Our understanding of individual metabolic networks is increasing as we learn more about the enzymes that are active in particular cells under particular conditions and as technologies advance to allow detailed measurements of the cellular metabolome. Metabolic network databases are of increasing importance in allowing us to contextualise data sets emerging from transcriptomic, proteomic and metabolomic experiments. Here we present a dynamic database, TrypanoCyc (http://www.metexplore.fr/trypanocyc/), which describes the generic and condition-specific metabolic network of Trypanosoma brucei, a parasitic protozoan responsible for human and animal African trypanosomiasis. In addition to enabling navigation through the BioCyc-based TrypanoCyc interface, we have also implemented a network-based representation of the information through MetExplore, yielding a novel environment in which to visualise the metabolism of this important parasite. Publisher PDF

Neuromyelitis optica spectrum disorder (NMO/SD) and its clinical variants have at their core the loss of immune tolerance to aquaporin-4 and perhaps other autoantigens. The characteristic phenotype is disruption of astrocyte function and demyelination of spinal cord, optic nerves, and particular brain regions. In this second of a 2-part article, we present further perspectives regarding the pathogenesis of NMO/SD and how this disease might be amenable to emerging technologies aimed at restoring immune tolerance to disease-implicated self-antigens. NMO/SD appears to be particularly well-suited for these strategies since aquaporin-4 has already been identified as the dominant autoantigen. The recent technical advances in reintroducing immune tolerance in experimental models of disease as well as in humans should encourage quantum leaps in this area that may prove productive for novel therapy. In this part of the article series, the potential for regulatory T and B cells is brought into focus, as are new approaches to oral tolerization. Finally, a roadmap is provided to help identify potential issues in clinical development and guide applications in tolerization therapy to solving NMO/SD through the use of emerging technologies. Each of these perspectives is intended to shine new light on potential cures for NMO/SD and other autoimmune diseases, while sparing normal host defense mechanisms.

Neuromyelitis optica (NMO) and spectrum disorder (NMO/SD) represent a vexing process and its clinical variants appear to have at their pathogenic core the loss of immune tolerance to the aquaporin-4 water channel protein. This process results in a characteristic pattern of astrocyte dysfunction, loss, and demyelination that predominantly affects the spinal cord and optic nerves. Although several empirical therapies are currently used in the treatment of NMO/SD, none has been proven effective in prospective, adequately powered, randomized trials. Furthermore, most of the current therapies subject patients to long-term immunologic suppression that can cause serious infections and development of cancers. The following is the first of a 2-part description of several key immune mechanisms in NMO/SD that might be amenable to therapeutic restoration of immune tolerance. It is intended to provide a roadmap for how potential immune tolerance restorative techniques might be applied to patients with NMO/SD. This initial installment provides a background rationale underlying attempts at immune tolerization. It provides specific examples of innovative approaches that have emerged recently as a consequence of technical advances. In several autoimmune diseases, these strategies have been reduced to practice. Therefore, in theory, the identification of aquaporin-4 as the dominant autoantigen makes NMO/SD an ideal candidate for the development of tolerizing therapies or cures for this increasingly recognized disease.

Non-streptococcal species found at the site of infection used in RPA assay exclusivity testing. (DOCX 22Â kb)

Clinical sample analysis results. (DOCX 24Â kb)

Brain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder, but the specific morphological and temporal patterns distinguishing them unequivocally from lesions caused by other disorders have not been identified. This literature review summarizes the literature on advanced quantitative imaging measures reported for patients with NMO spectrum disorder, including proton MR spectroscopy, diffusion tensor imaging, magnetization transfer imaging, quantitative MR volumetry, and ultrahigh-field strength MRI. It was undertaken to consider the advanced MRI techniques used for patients with NMO by different specialists in the field. Although quantitative measures such as proton MR spectroscopy or magnetization transfer imaging have not reproducibly revealed diffuse brain injury, preliminary data from diffusion-weighted imaging and brain tissue volumetry indicate greater white matter than gray matter degradation. These findings could be confirmed by ultrahigh-field MRI. The use of nonconventional MRI techniques may further our understanding of the pathogenic processes in NMO spectrum disorders and may help us identify the distinct radiographic features corresponding to specific phenotypic manifestations of this disease.

Current management of neuromyelitis optica (NMO) is noncurative and only partially effective. Immunosuppressive or immunomodulatory agents are the mainstays of maintenance treatment. Safer, better-tolerated, and proven effective treatments are needed. The perceived rarity of NMO has impeded clinical trials for this disease. However, a diagnostic biomarker and recognition of a wider spectrum of NMO presentations has expanded the patient population from which study candidates might be recruited. Emerging insights into the pathogenesis of NMO have provided rationale for exploring new therapeutic targets. Academic, pharmaceutical, and regulatory communities are increasingly interested in meeting the unmet needs of patients with NMO. Clinical trials powered to yield unambiguous outcomes and designed to facilitate rapid evaluation of an expanding pipeline of experimental agents are needed. NMO-related disability occurs incrementally as a result of attacks; thus, limiting attack frequency and severity are critical treatment goals. Yet, the severity of NMO and perception that currently available agents are effective pose challenges to study design. We propose strategies for NMO clinical trials to evaluate agents targeting recovery from acute attacks and prevention of relapses, the 2 primary goals of NMO treatment. Aligning the interests of all stakeholders is an essential step to this end.

VCU Theses and Dissertations

The following study investigates the use of a web-based mechanism that was designed to attempt to influence levels of self-efficacy by engaging participants in an experimental procedure. The process encouraged participants to monitor their time management behaviors and engage in a self-regulated learning process. The study utilized a web-based tool in order to attempt to evoke these changes using current and emerging instructional technologies and tools. This mechanism provided participants with feedback on their time management behaviors as they progressed through a two-week process of setting goals, monitoring their time management practices, and receiving feedback. Although no significant findings were discovered via the statistical analyses, many implications regarding the development and implementation of future interventions can be inferred. Ph. D.

A homologue of mammalian type II interleukin-1 receptor (IL-1RII) was isolated from a rainbow trout cDNA library by differential hybridization using a suppression subtractive hybridization generated probe enriched far sequences upregulated after immune stimulation. The trout cDNA has an ORF encoding 441 amino acids, and represents the first piscine IL-1 receptor described. The predicted amino-acid sequence has 29 and 26% identity with human and mouse IL-1RII, respectively. The trout IL-1 receptor has a domain organization similar to that of mammalian type II receptor, with a short cytoplasmic tail of 24 amino acids. These results suggest that type II receptor is also present in lower vertebrates, and therefore the duplication of an ancestral gene that generated type I and type II IL-1 receptors occurred prior to the time mammals emerged.

Udgivelsesdato: 2009-Sep OBJECTIVE: To identify components of a provisional clinical response index for thyroid eye disease using a modified Delphi technique. METHODS: The International Thyroid Eye Disease Society conducted a structured, 3-round Delphi exercise establishing consensus for a core set of measures for clinical trials in thyroid eye disease. The steering committee discussed the results in a face-to-face meeting (nominal group technique) and evaluated each criterion with respect to its feasibility, reliability, redundancy, and validity. Redundant measures were consolidated or excluded. RESULTS: Criteria were parsed into 11 domains for the Delphi surveys. Eighty-four respondents participated in the Delphi 1 survey, providing 220 unique items. Ninety-two members (100% of the respondents from Delphi 1 plus 8 new participants) responded in Delphi 2 and rated the same 220 items. Sixty-four members (76% of participants) rated 153 criteria in Delphi 3 (67 criteria were excluded because of redundancy). Criteria with a mean greater than 6 (1 = least appropriate to 9 = most appropriate) were further evaluated by the nominal group technique and provisional core measures were chosen. CONCLUSIONS: Using a Delphi exercise, we developed provisional core measures for assessing disease activity and severity in clinical trials of therapies for thyroid eye disease. These measures will be iteratively refined for use in multicenter clinical trials.

List of covered medications. (DOCX 34 kb)

List of covered medications. (DOCX 34 kb)

WorldCOM 12M progress and financial report

Infectious diseases, caused by pathogenic microorganisms such as bacteria, fungi or viruses, are a leading cause of significant global morbidity and mortality, with over 10 million associated deaths reported each year. Respiratory tract infections, such as bacterial meningitis, account for the highest rates of infectious disease related mortality. Bacterial meningitis infection is caused by human commensal bacteria that invade the respiratory tract and central nervous system leading to inflammation and rapid onset of symptoms, which can be fatal if untreated. Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae are the most common etiological agents of bacterial meningitis infection. S. pneumoniae and N. meningitidis are responsible for over 80% of all bacterial meningitis cases since the implementation of the H. influenzae type b (Hib) conjugate vaccine. However, H. influenzae related meningitis remains a serious threat in regions without immunisation and especially amongst children under five years of age. Global vaccination programmes have significantly reduced the occurrence of bacterial meningitis infection, however, approximately 1.2 million cases and over 100,000 related deaths are still reported annually, with increasing incidents of drug resistance leading to treatment failures. The global burden of bacterial meningitis infection is directly related to socioeconomic factors, with the highest rates of infection in low-resourced developing regions. The rate of infection in developed regions is approximately 1 in 100,000 persons per year, however, this can be as high as 20-40 in 100,000 persons per year in developing regions, with significantly higher mortality rates and severe impairments in survivors. The rapid and accurate detection of bacterial meningitis pathogens is essential for early and appropriate treatment which is directly linked with lower morbidity and mortality rates, and prevents broad-range antibiotic administration, a major contributing factor to antimicrobial-resistance dissemination. Isothermal nucleic acid amplification technologies such as recombinase polymerase amplification (RPA) and loop-mediated isothermal amplification (LAMP) offer rapid, sensitive and specific diagnostic approaches for the identification of bacterial meningitis associated pathogens. Additionally, these methods are low-cost, easy-to-use and compatible with point-of-care (POC) diagnostic technologies, essential for near-patient testing in poorer disease-burdened regions. This thesis describes the development and evaluation of novel RPA and LAMP technologies for the detection of S. pneumoniae, N. meningitidis and H. influenzae. These technologies include: three internally controlled duplex RPA assays for the detection of each pathogen; a novel Tth endonuclease cleavage loop-mediated isothermal amplification (TEC-LAMP) assay for the internally controlled multiplex detection of these pathogens; and novel loop-primer endonuclease cleavage loop-mediated isothermal amplification (LEC-LAMP) technology for the singleplex or multiplex detection of each pathogen with flexible single-base specificity for effective single nucleotide polymorphism detection. All technologies demonstrated efficient analytical specificity when tested with extensive exclusivity and inclusivity bacterial reference strains, and low limits of detection using Probit regression analysis. Clinical testing of each technology, using samples from confirmed cases of bacterial meningitis infection, demonstrated efficient diagnostic specificity and sensitivity. This thesis advanced the current state-of-the-art in multiplex isothermal nucleic acid amplification detection of these major bacterial meningitis pathogens, providing novel transferable diagnostics technology for infectious disease POC testing.

The benefits of wind turbines as a means for renewable energy generation are offset by the turbines’ creation of signal interference, such as Doppler shift, for radar systems used for air traffic control and weather forecasting. This restricts the placement of wind farms in the vicinity of radar installations. In this research, we investigate the effectiveness of placing a screen in front of a wind turbine in reducing turbine-generated Doppler shift interference. Software-defined radar (SDR) transmitting in continuous-wave mode was used to collect data required to analyze the signature of the Doppler returns. We built a rotator (i.e., an arm with metallic ball attached to one end) to establish the computation method to analyze the Doppler signature. Once the computation method was determined, measurements at various angles were carried out on the rotator with the aluminum shroud and screen included. Similar measurements were carried out on the scaled-down wind turbine model in Port Hueneme, CA, for comparison. This research shows that the SDR can be used to accurately measure the Doppler shift, and high-quality screens are effective in reducing the turbine-generated Doppler shift by more than 20 dB. http://archive.org/details/windturbineradar1094558328 Military Expert 5, Republic of Singapore Navy Approved for public release; distribution is unlimited.

Pregnancy and labour are physiological events controlled by a complex interplay between maternal and foetal factors. These processes are diverse and specific to each species, hence simple extrapolation from model organisms to humans is challenging. Nonetheless, understanding the underlying regulatory mechanisms involved is of utmost importance in the diagnosis and treatment of preterm and post-term labour. Throughout pregnancy the uterus maintains a quiescent state and develops a strong and rhythmic contraction towards parturition. Progesterone and oestrogen play vital roles in this transformation. In most mammals, high concentrations of progesterone dominate pregnancy (pro-relaxatory), while oestrogen (pro-contraction) levels take over towards labour. However, in humans the circulating levels of both progesterone and oestrogens remain high throughout pregnancy. Hence, functional withdrawal of progesterone and responsiveness to oestrogen is believed to occur more at the molecular level than at the circulating level. This study, therefore, focused on developing a myometrial smooth muscle cell culture model to evaluate the transcriptomic effect of steroid hormone treatment on cultured human uterine smooth muscle cells (hUtSMCs). Microarray-based gene expression analysis was performed on RNA isolated from hUtSMCs, treated with 17beta-estradiol (E2) and progesterone (P4) (separately or in combination) in addition to functional withdrawal of P4 with mifepristone (RU486) in order to identify differentially expressed genes associated with each treatment. Functional P4 withdrawal by RU486 altered the expression of these genes favouring myometrial contraction, whereas (P4+E2)-treatment favoured myometrial quiescence. The findings of these studies are in line with published reports on labouring and nonlabouring myometrium across various species, confirming that the cultured cell model system developed in the present study responds to hormonal treatments in a similar manner to that of the myometrium in vivo. The myometrial cell culture system is therefore an additional research tool that can be used for functional studies of human pregnancy and labour.

The main hypothesis on which this study has been based is that the surface modification of nano-particles of different size (Quantum Dots) and varying nano-surfaces roughness (Silicones of nanosurface roughness) can make them highly biocompatible in various applications of biology and medicine. In this work, attempts were made to investigate if the surface modification of nano-particles by gelatination of different size (Quantum Dots) makes them more biocompatible by reducing the toxicity on the cells and increasing the nano-surface roughness (Silicones of nanosurface roughness ranging from ~88 nm to ~650 nm) makes them more biocompatible by reducing the fibroblast growth of the cells in vitro. To address these questions, the nano-particles [CdTe Quantum dots of thioglycolic acid (TGA) capped gelatinated and non-gelatinated] and nano-surfaces (Silicones of nanosurface roughness) were characterised and then three different types of cells were used to check the biocompatibility in in vitro cell lines. At first, the Quantum Dots (QDs) were co-incubated with undifferentiated Pheochromocytoma12 (PC12) cells and investigated the cellular interaction, uptake and resultant toxic influence of the QD cell interplay was explored as the QD concentrations were varied over extended (up to 72 hours) co-incubation periods. Following this, QDs have been co-incubated with differentiated pheochromocytoma 12 (PC12) cells and the apoptotic process involved in the cell death machinery and also the intrinsic behaviour of QDs upon uptake by the cells have been analysed to extended (up to 17 days) co-incubation periods. In the same experiment, differentiated PC12 cells were also exposed to QDs after the neurites were grown for 10 days. Subsequently QDs were co-incubated with Human Pulmonary Microvascular Endothelial (HPMEC-ST1.6R) cells and analysed their cytotoxicity, differentially expressed genes and also their pathways involved to extended (up to 72 hours) co-incubation periods. Finally, the nano-surface roughnesses of silicone elastomer samples with rms surface roughnesses varying from ~88 nm to ~650 nm were co-incubated with NIH-3T3 fibroblast cells and analysed the total amount of DNA to extended (up to 24 hours) co-incubation periods. In conclusion, it was shown here that the surface modification of nano-particles (Quantum Dots) and nano-surfaces (Silicones of nanosurface roughness) were more biocompatible in vitro.

This thesis project explores two approaches for military tactical wireless communications solutions in the context of being useful for the Swedish Armed Forces. The study's tactical perspective focuses on a force of battalion size. The two network approaches, ad hoc networking and infrastructure based, were analyzed and compared via simulation. As a baseline for this thesis project, research was initiated based on appropriate communication requirements for the tactical force. This was followed by background research into current technologies for ad hoc networking and infrastructure-based systems. In order to analyze and compare the two technology approaches, a model was developed using the software Joint Communication Simulation System (JCSS) and a battalion-sized network simulation using ad hoc and infrastructure-based technology. This thesis project addressed tactical force requirements from the perspective of the basic Swedish Armed Forces principle for command and control, which is Maneuver Warfare. Evaluation of the technologies is discussed through the important perspectives of capacity, mobility, flexibility, robustness, interoperability, and cost. By analyzing the technology approaches from these perspectives, this thesis project attempts to provide the Swedish Armed Forces with more information and understanding, which in-turn will allow better-suited future developments of all tactical wireless communication systems. http://archive.org/details/comparativenalys109455555 Approved for public release; distribution is unlimited.

In order to quantify any node's capacity to support optimal information flow within a distributed command and control network, a novel node capability value calculation is developed from first principles. The expression for the node capability value is developed using three fundamental building blocks: data throughput, bandwidth efficiency, and the link margin. The data throughput depends on the average packet arrival rate, the probability of not dropping a packet and the probability of correct receiving a packet at the queue. The bandwidth efficiency depends on the node data rate and the transmission bandwidth, while the link margin is a function of the received and required energy per bit to noise power density. The generalized connectivity integrates the computed node capability value by considering all the distributed network connections scaled by their route length and estimating the characteristic tempo, which is the maximum information exchange rate. The generalized connectivity results reflect the amount and quality of detectable information that the nodes can process and transmit about the network. The results also show how the power and bandwidth efficiency of any specific node compares the power and bandwidth efficiency of all the other nodes. A four-node dynamic scenario is simulated and used to numerically evaluate the expression for the node capability value. Command and control tradeoff issues facing battlespace managers and decision makers are examined by including the networks characteristic tempo into a single observe, orient, decide and act (OODA loop). Also, included in the OODA loop, are action tempos and the command and control speed. Consideration of the influence of three classic Sheridan levels of automation on decision making are used to model the operational impacts via three action tempo tiers: high, medium, and low-action. Input command and control information rates produced the strongest observed influences on aggregate network simulation outputs. http://archive.org/details/adaptivenodecapa109455558 Approved for public release; distribution is unlimited.

The use of different pulse repetition frequencies (PRFs) delivers significantly different behaviors to airborne radars. For instance, the main purpose for using low PRF is to obtain an unambiguous range measurement. However, the tradeoff when using a low PRF is that the measurement of the target's radial velocity is highly ambiguous and can result in missing some target detections. On the other hand, high PRF is used to reduce or eliminate ambiguities in the measurement of radial velocity. A high PRF, however, causes a highly ambiguous range measurement. The true range is resolved by transmitting multiple waveforms with different PRFs. A modified form of pulse Doppler radar that operates at a medium PRF has both range and Doppler shift ambiguities. However, medium PRF is potentially better for detecting aircraft with low closing speeds than high PRF pulse Doppler. This thesis will focus on the effectiveness and localized optimization of medium PRF in airborne pulse Doppler radars, for the Turkish Air Force. This thesis will also present an analysis of medium PRF performance in a low altitude, air-to-air operating environment offering moderate range radar capability and also delivering acceptable range and Doppler resolution within that operating environment. http://archive.org/details/localizedoptimiz109455544 Approved for public release; distribution is unlimited.

Modern day warfare has presented the United States with a more technically savvy opponent in conflicts that have moved away from the traditional battlefield to the populated environment of the big city. Battle space dominance no longer refers simply to the physical nature of war, but now also encompasses a digital environment with a greater influence on Information Warfare. One of the keys to successfully maintaining open wireless lines of communication and extracting data,or denying the adversary the ability to communicate, is a complete understanding of radio wave propagation and the positive and negative effects of spreading and propagation losses. In a communication link, or radio wave transmission, several sources of degradation are mathematically accounted for, to include losses due to materials used, equipment setup, environmental factors, and interference associated with the actual frequencies. Up until recently, there were no studies evaluating the potential multipath losses that exist between a transmitter and receiver in an urban environment. This thesis will examine existing urban propagation models and evaluate their effectiveness in a variety of urban environments through a range of frequencies. http://archive.org/details/understandingndp109454654 US Navy (USN) author. Approved for public release; distribution is unlimited.

Air dominance is a key factor concerning today's warfare. Obtaining air dominance requires having a high degree of situational awareness. Unmanned aerial vehicles (UAVs) have gained popularity for surveillance and reconnaissance missions and provide situational awareness to ground-based military units. During operations it is necessary to maintain an uninterrupted data and control link between the UAV and the ground control station (GCS). This requires GCS antennas with signal-tracking capability. The work on this research was based on an ongoing project that originally started in 2002. The ultimate purpose is to design and build a digital phased-array antenna system that can automatically acquire, track, demodulate and decode video signals from a UAV using commercial-off-the-shelf (COTS) equipment. Previous work done includes integration of hardware components and development of software modules that allow the array system to auto-track signals from a UAV as well as decode the video signals in a standard format. The research in this thesis focused on allowing the system to demodulatethe video signals acquired by the digital tracking array. The baseband demodulation technique implemented was previously tested with video signals. A new technique utilizing tangent-type demodulation of signals was also implemented and tested using a bench-top test setup. http://archive.org/details/developmentofrec109455221 Turkish Air Force author Approved for public release; distribution is unlimited.

Electronic scanning is the most desirable feature of state-of-the-art radar systems. With electronic scanning, it is possible to steer the main beam of an array antenna instantaneously into a desired direction where no mechanical mechanism is involved in the scanning process. Electronic scanning methods including phase scanning, time delay scanning, and frequency scanning have been used in various radar applications; however new and cheaper scanning methods are still being investigated. It is the purpose of this thesis to investigate an array configuration called frequency diverse array (FDA), which gives rise to range-, time-, and angle-dependent scanning without using phase shifters. In this thesis, first, frequency diverse array as a time-modulated array is presented. A general analysis and the theory of time domain scanning is given. Equations derived for a time-modulated frequency diverse array are simulated using MATLAB. Amplitude tapering and Fourier series expansion is implemented in MATLAB and the results are provided for comparison. Secondly, analysis of a frequency diverse array is presented. Time-, range-, and angle-dependent electronic scanning is achieved by applying a small amount of frequency shift among the antenna elements. The simulation results for radiation patterns with various excitation types are given. Lastly, the radar applications of FDA are considered. The received power from a target at a fixed range is simulated in MATLAB and the results are presented. http://archive.org/details/frequencydiverse109455113 Turkish Navy author Approved for public release; distribution is unlimited.

This wireless distributed digital phase array (WDDPA) has been proposed for several military applications in the sensor and communication areas. The idea of WDDPA is to use a wireless network for transmitting and receiving data between a master controller and modules in an active phased array instead of using a conventional wired beamforming network. The WDDPA provides several advantages over conventional networks such as battlefield survivability, digital architecture and flexibility of system installation on platforms. A phase synchronization circuit has been developed in the WDDPA application, allowing coherent processing of the data from all elements. There are limitations encountered due to non-ideal hardware, and the performance of the circuit is limited. One of the major problems is the leakage from the circulator. The leakage disrupts the power distributed from the T/R modules. A cancellation circuit has been developed to cancel out the leakage. The performance of the cancellation circuit was investigated by a series of simulations using Agilent ADS (Agilent Advanced Design System), and hardware tests were conducted to characterize the behavior of the circuit. The performance is limited by the accuracy of the attenuator and phase shifter in the cancelation branch. A method for cancelling the residual leakage signal digitally is discussed. http://archive.org/details/cancellationcirc109455119 Republic of China Navy author Approved for public release; distribution is unlimited.

The Joint Tactical Information Distribution System (JTIDS) is a hybrid frequencyhopped, direct sequence spread spectrum system that employs a (31, 15) Reed-Solomon (RS) code for forward error correction coding. In this thesis, an alternative error correction coding scheme that uses concatenated coding with a (31, k) RS inner code and a rate 4/5 convolutional outer code is considered. In addition, a sequential diversity of two, consistent with the JTIDS double-pulse structure, is considered both for soft decision (SD) RS decoding and for soft diversity combining with noise-normalization. Both coherent and noncoherent detection are considered. Based on the analyses, the alternative JTIDS waveform outperforms the original in all cases considered. When only additive white Gaussian noise is present, the best performances, which result in a gain of about 1.4 dB relative to the existing JTIDS waveform, are achieved for (31, 23) RS and (31, 25) RS inner codes for coherent detection and for (31, 27) RS and (31, 29) RS inner codes for noncoherent detection. For these RS inner codes, a 23.0% and 33.0% improvement in system throughput is achieved, respectively, for coherent detection, and a 44.0% and 55.0% improvement in throughput is achieved, respectively, for noncoherent detection relative to the existing JTIDS waveform. Noise-normalization neutralizes the effects of pulse-noise interference, but no significant benefits are obtained from using SD RS decoding. http://archive.org/details/performancenalys109455222 Hellenic Navy author Approved for public release; distribution is unlimited.

Like High Altitude Electromagnetic Pulse (HEMP), high power microwaves (HPM) produce intense energies, which may overload or damage various electrical system components such as microcircuits. This thesis investigates possible effects of a hypothetically designed HEMP-like weapon, an "e-bomb," on electronically equipped target systems. The procedure to determine these possible effects is to estimate the electromagnetic coupling from first principles and simulations using a coupling model program (CEMPAT), pursuing a feasible geometry of attack, practical antennas, best coupling approximations of ground conductivity and permittivity, a reasonable system of interest representation from specifications, threat waveshape and operating frequency. The analysis procedure investigates roles of these factors contributes to the e-bomb coupling scenario. Those possible e-bomb effect results are then compared to a published and experimentally created threshold level table to determine whether any upset or damage is formed on the target system. Based on this comparison, the results are evaluated with respect to the factors that caused them to exceed, or not exceed, the threshold levels. Additionally, a conventional weapon attack scenario for the same target system is created. Its results are compared to the e-bomb attack. Finally, operational recommendations are given along with advantages and disadvantages for each type of attack. http://archive.org/details/simulatedebombef109454606 Turkish Air Force author. Approved for public release; distribution is unlimited.

C system. The thesis also explains the testing procedures of the transceiver and the design, test, and integration of the primary and secondary antennas. Finally the thesis explains the frequency licensing process through the Navy-Marine Corps Spectrum Center and the Federal Communications Commission. http://archive.org/details/npsscatcubesatco109454737 US Marine Corps (USMC) author. Approved for public release; distribution is unlimited.

The contemporary military rivalry is driven mostly by the ongoing military technical revolution. In particular, the weapons used on the future battlefield will play an important role in military affairs. Which weapons can play a key role in the future? Electromagnetic weapons seem to involve key elements for the future battlefield; they offer advantages over conventional weaponry by providing nonlethality, the advantage of attack at the speed of light, fast engagement of multiple targets, potentially low operational cost, and wide-area coverage for offensive and defensive purposes. This thesis proposes hypothetical electromagnetic bombs (e-bomb) and classifies e-bombs into three isocategories depending on power sources. It also assesses the potential lethality effects on different targets based on a developed MATLAB Simulation Model. It also provides an understanding of the principles of High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Weapons. In addition, a measure of effectiveness model is proposed to compare the hypothetical e-bomb, HEMP and HPM weapons. The strategic effects on military affairs will be assessed. Finally, this study will help the Turkish Armed Forces decide on investment in e-bomb research and development (R&D) to improve combat capabilities in the future battlefield. The contemporary military rivalry is driven mostly by the ongoing military technical revolution. In particular, the weapons used on the future battlefield will play an important role in military affairs. Which weapons can play a key role in the future? Electromagnetic weapons seem to involve key elements for the future battlefield; they offer advantages over conventional weaponry by providing nonlethality, the advantage of attack at the speed of light, fast engagement of multiple targets, potentially low operational cost, and wide-area coverage for offensive and defensive purposes. This thesis proposes hypothetical electromagnetic bombs (e-bomb) and classifies e-bombs into three isocategories depending on power sources. It also assesses the potential lethality effects on different targets based on a developed MATLAB Simulation Model. It also provides an understanding of the principles of High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Weapons. In addition, a measure of effectiveness model is proposed to compare the hypothetical e-bomb, HEMP and HPM weapons. The strategic effects on military affairs will be assessed. Finally, this study will help the Turkish Armed Forces decide on investment in e-bomb research and development (R&D) to improve combat capabilities in the future battlefield. http://archive.org/details/ebombkeyelemento109453996 Outstanding Thesis Turkish Navy author. Approved for public release; distribution is unlimited.