Simulating and Designing RF Transmitter for Small Satellites

This paper discusses the simulation and the design of an RF transmitter for small satellites operating in the commercial S- band (2.2 - 2.29 GHz) with a data rate of 8Mbps. In such systems, modelling frequency-dependent nonlinear characteristics of complex analog blocks and subsystems is critical for enabling efficient verification of mixed-signal system designs. In order to provide efficient and accurate simulation for the transmitter circuits, simple macromodels for weakly nonlinear mixer and power amplifier are used in the system simulation. Also, we introduce the noise in several circuits (frequency synthesizer, crystal oscillator, power amplifier, mixer,…) and we demonstrate their effect on the noise performance system. In the simulation we consider features of components and technologies commercially available

Cloning and characterization of novel methylsalicylic acid synthase gene involved in the biosynthesis of isoasperlactone and asperlactone in Aspergillus westerdijkiae

Aspergillus westerdijkiae is the main producer of several biologically active polyketide metabolites including isoasperlactone and asperlactone. A 5298 bp polyketide synthase gene ‘‘aomsas” has been cloned in Aspergillus westerdijkiae by using gene walking approach and RACE-PCR. The predicted amino acid sequence of aomsas shows an identity of 40–56% with different methylsalicylic acid synthase genes found in Byssochlamys nivea, P. patulum, A. terreus and Streptomyces viridochromogenes. Based on the reverse transcription PCR and kinetic secondary metabolites production studies, aomsas expression was found to be associated with the biosynthesis of isoasperlactone and asperlactone. Moreover an aomsas knockout mutant ‘‘aoDmsas” of A. westerdijkiae, not only lost the capacity to produce isoasperlactone and asperlactone,but also 6-methylsalicylic acid. The genetically complemented mutant ao+msas restored the biosynthesis of all the missing metabolites. Chemical complementation through the addition of 6-methylsalicylic acid, aspyrone and diepoxide to growing culture of aoDmsas mutant revealed that these compounds play intermediate roles in the biosynthesis of asperlactone and isoasperlactone

Deep Learning for Scene Recognition from Visual Data:A Survey

The use of deep learning techniques has exploded during the last few years, resulting in a direct contribution to the field of artificial intelligence. This work aims to be a review of the state-of-the-art in scene recognition with deep learning models from visual data. Scene recognition is still an emerging field in computer vision, which has been addressed from a single image and dynamic image perspective. We first give an overview of available datasets for image and video scene recognition. Later, we describe ensemble techniques introduced by research papers in the field. Finally, we give some remarks on our findings and discuss what we consider challenges in the field and future lines of research. This paper aims to be a future guide for model selection for the task of scene recognition

Challenges and experiences in linking community level reported out-of-pocket health expenditures to health provider recorded health expenditures: experience from the iHOPE project in Northern Ghana

Out of pocket health payment (OOPs) has been identified by the System of Health Accounts (SHA) as the largest source of health care financing in most low and middle-income countries. This means that most low and middle-income countries will rely on user fees and co-payments to generate revenue, rationalize the use of services, contain health systems costs or improve health system efficiency and service quality. However, the accurate measurement of OOPs has been challenged by several limitations which are attributed to both sampling and non-sampling errors when OOPs are estimated from household surveys, the primary source of information in LICs and LMICs. The incorrect measurement of OOP health payments can undermine the credibility of current health spending estimates, an otherwise important indicator for tracking UHC, hence there is the need to address these limitations and improve the measurement of OOPs. In an attempt to improve the measurement of OOPs in surveys, the INDEPTH-Network Household out-of-pocket expenditure project (iHOPE) developed new modules on household health utilization and expenditure by repurposing the existing Ghana Living Standards Survey instrument and validating these new tools with a 'gold standard' (provider data) with the aim of proposing alternative approaches capable of producing reliable data for estimating OOPs in the context of National Health Accounts and for the purpose of monitoring financial protection in health. This paper reports on the challenges and opportunities in using and linking household reported out-of-pocket health expenditures to their corresponding provider records for the purpose of validating household reported out-of-pocket health expenditure in the iHOPE project

Wheat rust epidemics damage Ethiopian wheat production: A decade of field disease surveillance reveals national-scale trends in past outbreaks.

Wheat rusts are the key biological constraint to wheat production in Ethiopia-one of Africa's largest wheat producing countries. The fungal diseases cause economic losses and threaten livelihoods of smallholder farmers. While it is known that wheat rust epidemics have occurred in Ethiopia, to date no systematic long-term analysis of past outbreaks has been available. We present results from one of the most comprehensive surveillance campaigns of wheat rusts in Africa. More than 13,000 fields have been surveyed during the last 13 years. Using a combination of spatial data-analysis and visualization, statistical tools, and empirical modelling, we identify trends in the distribution of wheat stem rust (Sr), stripe rust (Yr) and leaf rust (Lr). Results show very high infection levels (mean incidence for Yr: 44%; Sr: 34%; Lr: 18%). These recurrent rust outbreaks lead to substantial economic losses, which we estimate to be of the order of 10s of millions of US-D annually. On the widely adopted wheat variety, Digalu, there is a marked increase in disease prevalence following the incursion of new rust races into Ethiopia, which indicates a pronounced boom-and-bust cycle of major gene resistance. Using spatial analyses, we identify hotspots of disease risk for all three rusts, show a linear correlation between altitude and disease prevalence, and find a pronounced north-south trend in stem rust prevalence. Temporal analyses show a sigmoidal increase in disease levels during the wheat season and strong inter-annual variations. While a simple logistic curve performs satisfactorily in predicting stem rust in some years, it cannot account for the complex outbreak patterns in other years and fails to predict the occurrence of stripe and leaf rust. The empirical insights into wheat rust epidemiology in Ethiopia presented here provide a basis for improving future surveillance and to inform the development of mechanistic models to predict disease spread

Political candidates in infotainment programmes and their emotional effects on Twitter: An analysis of the 2015 Spanish general elections pre-campaign season

This is an Accepted Manuscript of an article published by Taylor & Francis in Contemporary Social Science on 2019, available online: http://www.tandfonline.com/10.1080/21582041.2017.1367833.[EN] The infotainment format offers candidates an informal setting to show a more personal side of themselves to the electorate, opening themselves up to potential voters. An example of media hybridisation, social networks users can immediately comment on infotainment television programmes, a process known as second screening. These second screeners tend to be especially active in politics. This paper analyses the immediate emotional reaction of these users as they watch infotainment programmes that air during the campaign or pre-campaign seasons and feature political candidates as guests. We have confirmed that second screeners react more emotionally towards the candidate when his or her party is mentioned, and less emotionally when the host displays an aggressive attitude through his or her non-verbal communication. When issues related to the candidate¿s personal lives are discussed, users¿ emotional reactions improve slightly. The relevance of this research stems from the fact that we are witnessing the consolidation of a politics that increasingly strays from ideological questions, and instead focuses on more emotional and personal issues.This work was supported by the Ministerio de Economia y Competitividad under Grants CSO2013-43960-R and CSO2016-77331-C2-1-R.Baviera, T.; Peris, À.; Cano-Orón, L. (2019). Political candidates in infotainment programmes and their emotional effects on Twitter: An analysis of the 2015 Spanish general elections pre-campaign season. 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The Hybrid Media System. doi:10.1093/acprof:oso/9780199759477.001.0001Dang-Xuan, L., Stieglitz, S., Wladarsch, J., & Neuberger, C. (2013). AN INVESTIGATION OF INFLUENTIALS AND THE ROLE OF SENTIMENT IN POLITICAL COMMUNICATION ON TWITTER DURING ELECTION PERIODS. Information, Communication & Society, 16(5), 795-825. doi:10.1080/1369118x.2013.783608Giglietto, F., & Selva, D. (2014). Second Screen and Participation: A Content Analysis on a Full Season Dataset of Tweets. Journal of Communication, 64(2), 260-277. doi:10.1111/jcom.12085Grabe, M. E., & Bucy, E. P. (2009). Image Bite Politics. doi:10.1093/acprof:oso/9780195372076.001.0001Guo, L., & Vargo, C. (2015). The Power of Message Networks: A Big-Data Analysis of the Network Agenda Setting Model and Issue Ownership. Mass Communication and Society, 18(5), 557-576. doi:10.1080/15205436.2015.1045300Harrington, S. (2008). Popular news in the 21st century Time for a new critical approach? Journalism: Theory, Practice & Criticism, 9(3), 266-284. doi:10.1177/1464884907089008López-Rico, C.-M., & Peris-Blanes, À. (2017). Agenda e imagen de los candidatos de las elecciones generales de 2015 en España en programas televisivos de infoentretenimiento. El Profesional de la Información, 26(4), 611. doi:10.3145/epi.2017.jul.05Maruyama, M., Robertson, S. P., Douglas, S., Raine, R., & Semaan, B. (2017). Social Watching a Civic Broadcast. Proceedings of the 2017 ACM Conference on Computer Supported Cooperative Work and Social Computing. doi:10.1145/2998181.2998340Medhat, W., Hassan, A., & Korashy, H. (2014). Sentiment analysis algorithms and applications: A survey. Ain Shams Engineering Journal, 5(4), 1093-1113. doi:10.1016/j.asej.2014.04.011Saif, H., He, Y., & Alani, H. (2012). Semantic Sentiment Analysis of Twitter. Lecture Notes in Computer Science, 508-524. doi:10.1007/978-3-642-35176-1_32Shah, D. V., Hanna, A., Bucy, E. P., Lassen, D. S., Van Thomme, J., Bialik, K., … Pevehouse, J. C. W. (2016). Dual Screening During Presidential Debates. American Behavioral Scientist, 60(14), 1816-1843. doi:10.1177/0002764216676245Sullivan, D. G., & Masters, R. D. (1988). «Happy Warriors»: Leaders’ Facial Displays, Viewers’ Emotions, and Political Support. American Journal of Political Science, 32(2), 345. doi:10.2307/2111127Thelwall, M., Buckley, K., Paltoglou, G., Cai, D., & Kappas, A. (2010). Sentiment strength detection in short informal text. Journal of the American Society for Information Science and Technology, 61(12), 2544-2558. doi:10.1002/asi.21416Vergeer, M., & Franses, P. H. (2015). Live audience responses to live televised election debates: time series analysis of issue salience and party salience on audience behavior. Information, Communication & Society, 19(10), 1390-1410. doi:10.1080/1369118x.2015.1093526Vilares, D., Thelwall, M., & Alonso, M. A. (2015). The megaphone of the people? Spanish SentiStrength for real-time analysis of political tweets. Journal of Information Science, 41(6), 799-813. doi:10.1177/0165551515598926Wohn, D. Y., & Na, E.-K. (2011). Tweeting about TV: Sharing television viewing experiences via social media message streams. First Monday. doi:10.5210/fm.v16i3.336

Green Propellant Infusion Mission Program Development and Technology Maturation

The NASA Space Technology Mission Directorate's (STMD) Green Propellant Infusion Mission (GPIM) Technology Demonstration Mission (TDM) is comprised of a cross-cutting team of domestic spacecraft propulsion and storable green propellant technology experts. This TDM is led by Ball Aerospace & Technologies Corp. (BATC), who will use their BCP- 100 spacecraft to carry a propulsion system payload consisting of one 22 N thruster for primary divert (DeltaV) maneuvers and four 1 N thrusters for attitude control, in a flight demonstration of the AF-M315E technology. The GPIM project has technology infusion team members from all three major market sectors: Industry, NASA, and the Department of Defense (DoD). The GPIM project team includes BATC, includes Aerojet Rocketdyne (AR), Air Force Research Laboratory, Aerospace Systems Directorate, Edwards AFB (AFRL), NASA Glenn Research Center (GRC), NASA Kennedy Space Center (KSC), and NASA Goddard Space Flight Center (GSFC). STMD programmatic and technology oversight is provided by NASA Marshall Space Flight Center. The GPIM project shall fly an operational AF-M315E green propulsion subsystem on a Ball-built BCP-100 spacecraft

Holonomic functions of several complex variables and singularities of anisotropic Ising n-fold integrals

Lattice statistical mechanics, often provides a natural (holonomic) framework to perform singularity analysis with several complex variables that would, in a general mathematical framework, be too complex, or could not be defined. Considering several Picard-Fuchs systems of two-variables "above" Calabi-Yau ODEs, associated with double hypergeometric series, we show that holonomic functions are actually a good framework for actually finding the singular manifolds. We, then, analyse the singular algebraic varieties of the n-fold integrals $\chi^{(n)}$, corresponding to the decomposition of the magnetic susceptibility of the anisotropic square Ising model. We revisit a set of Nickelian singularities that turns out to be a two-parameter family of elliptic curves. We then find a first set of non-Nickelian singularities for $\chi^{(3)}$ and $\chi^{(4)}$, that also turns out to be rational or ellipic curves. We underline the fact that these singular curves depend on the anisotropy of the Ising model. We address, from a birational viewpoint, the emergence of families of elliptic curves, and of Calabi-Yau manifolds on such problems. We discuss the accumulation of these singular curves for the non-holonomic anisotropic full susceptibility.Comment: 36 page