Application of Random Walk Model for Timing Recovery in Modern Mobile SATCOM Systems

In a modern mobile satellite communication (SATCOM) system, a ground terminal receiver receives a radio frequency signal that is demodulated to generate a baseband digital signal waveform containing a self-clocking bit stream of digital data. The received baseband digital signal waveform is recovered and tracked using a timing recovery loop (TRL). The traditional TRLs use early-and-late gates, digital transition tracking, filter-and-square, and delay-and-multiply functions. In bit timing detection, the bit stream is self-clocking and the timing differential dithers about correct bit timing in the TRLs. For mobile satellite communication environments, the traditional TRLs drop lock when the loop signal-to-noise ratio (SNR) is smaller than a threshold value or the residual Doppler frequency is larger than the operating loop bandwidth. After dropping lock, the traditional TRLs experience long hang up time due to the need to reacquire the timing pulses. Recently, random walk filters (RWF) have been adapted to improve the bit clock locking stability and are applied to recover bit timing information of a digital data stream. This chapter describes random walk model for timing jitter and discusses how RWF solution can address the timing recovery challenges in mobile satellite communication environments

Blood feeding patterns of mosquitoes: random or structured?

<p>Abstract</p> <p>Background</p> <p>The foraging behavior of blood-sucking arthropods is the defining biological event shaping the transmission cycle of vector-borne parasites. It is also a phenomenon that pertains to the realm of community ecology, since blood-feeding patterns of vectors can occur across a community of vertebrate hosts. Although great advances in knowledge of the genetic basis for blood-feeding choices have been reported for selected vector species, little is known about the role of community composition of vertebrate hosts in determining such patterns.</p> <p>Methods & Results</p> <p>Here, we present an analysis of feeding patterns of vectors across a variety of locations, looking at foraging patterns of communities of mosquitoes, across communities of hosts primarily comprised of mammals and birds. Using null models of species co-occurrence, which do not require ancillary information about host abundance, we found that blood-feeding patterns were aggregated in studies from multiple sites, but random in studies from a single site. This combination of results supports the idea that mosquito species in a community may rely primarily on host availability in a given landscape, and that contacts with specific hosts will be influenced more by the presence/absence of hosts than by innate mosquito choices. This observation stresses the importance of blood-feeding plasticity as a key trait explaining the emergence of many zoonotic mosquito transmitted diseases.</p> <p>Discussion</p> <p>From an epidemiological perspective our observations support the idea that phenomena promoting synchronization of vectors and hosts can promote the emergence of vector-borne zoonotic diseases, as suggested by observations on the linkages between deforestation and the emergence of several human diseases.</p

War-Gaming Applications for Achieving Optimum Acquisition of Future Space Systems

This chapter describes an innovative modeling and simulation approach using newly proposed Advanced Game-based Mathematical Framework (AGMF), Unified Game-based Acquisition Framework (UGAF) and a set of War-Gaming Engines (WGEs) to address future space systems acquisition challenges. Its objective is to assist the DoD Acquisition Authority (DAA) to understand the contractor’s perspective and to seek optimum Program-and-Technical-Baseline (PTB) solution and corresponding acquisition strategy under both the perspectives of the government and the contractors. The proposed approach calls for an interdisciplinary research that involves game theory, probability and statistics, and non-linear programming. The goal of this chapter is to apply the proposed war-gaming frameworks to develop and evaluate PTB solutions and associated acquisition strategies in the context of acquisition of future space systems. Our simulation results suggest that our optimization problem for the acquisition of future space systems meets the affordability and innovative requirements with minimum acquisition risk

Modeling vegetative vigour in grapevine: unraveling underlying mechanisms

Mechanistic modeling constitutes a powerful tool to unravel complex biological phenomena. This study describes the construction of a mechanistic, dynamic model for grapevine plant growth and canopy biomass (vigor). To parametrize and validate the model, the progeny from a cross of Ramsey (Vitis champinii) × Riparia Gloire (V. riparia) was evaluated. Plants with different vigor were grown in a greenhouse during the summer of 2014 and 2015. One set of plants was grafted with Cabernet Sauvignon. Shoot growth rate (b), leaf area (LA), dry biomass, whole plant and root specific hydraulic conductance (kH and Lpr), stomatal conductance (gs), and water potential (Ψ) were measured. Partitioning indices and specific leaf area (SLA) were calculated. The model includes an empirical fit of a purported seasonal pattern of bioactive GAs based on published seasonal evolutionary levels and reference values. The model provided a good fit of the experimental data, with R = 0.85. Simulation of single trait variations defined the individual effect of each variable on vigor determination. The model predicts, with acceptable accuracy, the vigor of a young plant through the measurement of Lpr and SLA. The model also permits further understanding of the functional traits that govern vigor, and, ultimately, could be considered useful for growers, breeders and those studying climate change.EEA MendozaFil: Hugalde, Ines Pilar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. University of California at Davis. Department of Viticulture and Enology; Estados UnidosFil: Agüero, Cecilia B. University of California at Davis. Department of Viticulture and Enology; Estados UnidosFil: Barrios-Masias, Felipe H. University of California at Davis. Department of Viticulture and Enology; Estados Unidos. University of Nevada. Department of Agriculture, Veterinary and Rangeland Sciences; Estados UnidosFil: Romero, Nina. University of California at Davis. Department of Viticulture and Enology; Estados UnidosFil: Nguyen, Andy Viet. University of California at Davis. Department of Viticulture and Enology; Estados UnidosFil: Riaz, Summaira. University of California at Davis. Department of Viticulture and Enology; Estados UnidosFil: Piccoli, Patricia Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: McElrone, Andrew J. University of California at Davis. Department of Viticulture and Enology; Estados Unidos. US Department of Agriculture. ARS; Estados UnidosFil: Walker, M. Andrew. University of California at Davis. Department of Viticulture and Enology; Estados UnidosFil: Vila, Hernan Felix. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentin

Impact of High Volume Energy Drink Consumption on Electrocardiographic and Blood Pressure Parameters: A Randomized Trial

Background Energy drinks have been linked to an increase in emergency room visits and deaths. We aim to determine the impact of energy drinks on electrocardiographic and hemodynamic parameters in young healthy volunteers. Methods and Results A randomized, double-masked, placebo-controlled, crossover study was conducted in healthy volunteers. Participants consumed 32 oz of either energy drink A, energy drink B, or placebo within 60 minutes on 3 study days with a 6-day washout period in between. The primary end point of QT c interval and secondary end points of QT interval, PR interval, QRS duration, heart rate, and brachial and central blood pressures were measured at baseline, and every 30 minutes for 240 minutes. A repeated-measures 2-way analysis of variance was performed with the main effects of intervention, time, and an interaction of intervention and time. Thirty-four participants were included (age 22.1±3.0 years). The interaction term of intervention and time was statistically significant for Bazett\u27s corrected QT interval, Fridericia\u27s corrected QT interval, QT , PR , QRS duration, heart rate, systolic blood pressure, diastolic blood pressure, central systolic blood pressure, and central diastolic blood pressure (all

The loss of STAT3 in mature osteoclasts has detrimental effects on bone structure

Signal Transducer and Activator of Transcription 3 (STAT3) has recently been shown to be involved in bone development and has been implicated in bone diseases, such as Job’s Syndrome. Bone growth and changes have been known for many years to differ between sexes with male bones tending to have higher bone mass than female bones and older females tending to lose bone mass at faster rates than older males. Previous studies using conditional knock mice with Stat3 specifically deleted from the osteoblasts showed both sexes exhibited decreased bone mineral density (BMD) and strength. Using the Cre-Lox system with Cathepsin K promotor driving Cre to target the deletion of the Stat3 gene in mature osteoclasts (STAT3-cKO mice), we observed that 8-week old STAT3-cKO female femurs exhibited significantly lower BMD and bone mineral content (BMC) compared to littermate control (CN) females. There were no differences in BMD and BMC observed between male knock-out and male CN femurs. However, micro-computed tomography (μCT) analysis showed that both male and female STAT3-cKO mice had significant decreases in bone volume/tissue volume (BV/TV). Bone histomorphometry analysis of the distal femur, further revealed a decrease in bone formation rate and mineralizing surface/bone surface (MS/BS) with a significant decrease in osteoclast surface in female, but not male, STAT3-cKO mice. Profiling gene expression in an osteoclastic cell line with a knockdown of STAT3 showed an upregulation of a number of genes that are directly regulated by estrogen receptors. These data collectively suggest that regulation of STAT3 differs in male and female osteoclasts and that inactivation of STAT3 in osteoclasts affects bone turnover more in females than males, demonstrating the complicated nature of STAT3 signaling pathways in osteoclastogenesis. Drugs targeting the STAT3 pathway may be used for treatment of diseases such as Job’s Syndrome and osteoporosis

Development and Validation of Nomograms Predictive of Overall and Progression-Free Survival in Patients With Oropharyngeal Cancer

Purpose Treatment of oropharyngeal squamous cell carcinoma (OPSCC) is evolving toward risk-based modification of therapeutic intensity, which requires patient-specific estimates of overall survival (OS) and progression-free survival (PFS). Methods To develop and validate nomograms for OS and PFS, we used a derivation cohort of 493 patients with OPSCC with known p16 tumor status (surrogate of human papillomavirus) and cigarette smoking history (pack-years) randomly assigned to clinical trials using platinum-based chemoradiotherapy (NRG Oncology Radiation Therapy Oncology Group [RTOG] 0129 and 0522). Nomograms were created from Cox models and internally validated by use of bootstrap and cross-validation. Model discrimination was measured by calibration plots and the concordance index. Nomograms were externally validated in a cohort of 153 patients with OPSCC randomly assigned to a third trial, NRG Oncology RTOG 9003. Results Both models included age, Zubrod performance status, pack-years, education, p16 status, and T and N stage; the OS model also included anemia and age × pack-years interaction; and the PFS model also included marital status, weight loss, and p16 × Zubrod interaction. Predictions correlated well with observed 2-year and 5-year outcomes. The uncorrected concordance index was 0.76 (95% CI, 0.72 to 0.80) for OS and 0.70 (95% CI, 0.66 to 0.74) for PFS, and bias-corrected indices were similar. In the validation set, OS and PFS models were well calibrated, and OS and PFS were significantly different across tertiles of nomogram scores (log-rank P = .003;\u3c .001). Conclusion The validated nomograms provided useful prediction of OS and PFS for patients with OPSCC treated with primary radiation-based therapy

Viral Kinetics and Resistance Development in Children Treated with Neuraminidase Inhibitors: The Influenza Resistance Information Study (IRIS)

BackgroundWe studied the effect of age, baseline viral load, vaccination status, antiviral therapy, and emergence of drug resistance on viral shedding in children infected with influenza A or B virus.MethodsSamples from children (aged ≤13 years) enrolled during the 7 years of the prospective Influenza Resistance Information Study were analyzed using polymerase chain reaction to determine the influenza virus (sub-)type, viral load, and resistance mutations. Disease severity was assessed; clinical symptoms were recorded. The association of age with viral load and viral clearance was examined by determining the area under the curve for viral RNA shedding using logistic regression and Kaplan-Meier analyses.ResultsA total of 2131 children infected with influenza (683, A/H1N1pdm09; 825, A/H3N2; 623, influenza B) were investigated. Age did not affect the mean baseline viral load. Children aged 1−5 years had prolonged viral RNA shedding (±1–2 days) compared with older children and up to 1.2-fold higher total viral burden. Besides, in older age (odds ratio [OR], 1.08; confidence interval [CI], 1.05–1.12), prior vaccination status (OR, 1.72; CI, 1.22–2.43) and antiviral treatment (OR, 1.74; CI, 1.43–2.12) increased the rate of viral clearance. Resistance mutations were detected in 49 children infected with influenza A virus (34, A/H1N1pdm09; 15, A/H3N2) treated with oseltamivir, most of whom were aged [under]5 years (n = 39).ConclusionsChildren aged 1−5 years had a higher total viral burden with prolonged virus shedding and had an increased risk of acquiring resistance mutations following antiviral treatment.Clinical Trials RegistrationNCT00884117

Waterpipe tobacco use in the United Kingdom: A cross-sectional study among university students and stop smoking practitioners

© 2016 Jawad et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Introduction: Despite cigarette-like adverse health outcomes associated with waterpipe tobacco smoking and increase in its use among youth, it is a much underexplored research area. We aimed to measure the prevalence and patterns of waterpipe tobacco use and evaluate tobacco control policy with respect to waterpipe tobacco, in several universities across the UK. We also aimed to measure stop smoking practitioners' encounter of waterpipe tobacco smoking. Methods: We distributed an online survey to six UK universities, asking detailed questions on waterpipe tobacco. Multivariable logistic regression models, adjusted for age, gender, ethnicity, graduate status, university and socioeconomic status (SES) assessed associations between waterpipe tobacco smoking (single use and dual use with cigarettes) and sociodemographic variables. SES was ascertained by average weekly self-spend on non-essentials. We also descriptively analysed data from a 2012 survey of stop smoking practitioners to assess the proportion of clients that used waterpipe regularly. Results: f 2217 student responses, 66.0%(95% CI 63.9-68.0%) had tried waterpipe tobacco smoking; 14.3%(95% CI 12.8-15.8%) reported past-30 day use, and 8.7% (95% CI 7.6-9.9%) reported at least monthly users. Past-30 day waterpipe-only use was associated with being younger (AOR 0.95, 95% CI 0.91-0.99), male (AOR 1.44, 95% CI 1.08-1.94), higher SES (AOR 1.16, 95% CI 1.06-1.28) and belonging to non-white ethnicities (vs. white, AOR 2.24, 95% CI 1.66-3.04). Compared to less than monthly users, monthly users were significantly more likely to have urges to smoke waterpipe (28.1% vs. 3.1%,