A multimission three-axis stabilized spacecraft flight dynamics ground support system

The Multimission Three-Axis Stabilized Spacecraft (MTASS) Flight Dynamics Support System (FDSS) has been developed in an effort to minimize the costs of ground support systems. Unlike single-purpose ground support systems, which attempt to reduce costs by reusing software specifically developed for previous missions, the multimission support system is an intermediate step in the progression to a fully generalized mission support system in which numerous missions may be served by one general system. The benefits of multimission attitude ground support systems extend not only to the software design and coding process, but to the entire system environment, from specification through testing, simulation, operations, and maintenance. This paper reports the application of an MTASS FDSS to multiple scientific satellite missions. The satellites are the Upper Atmosphere Research Satellite (UARS), the Extreme Ultraviolet Explorer (EUVE), and the Solar Anomalous Magnetospheric Particle Explorer (SAMPEX). Both UARS and EUVE use the multimission modular spacecraft (MMS) concept. SAMPEX is part of the Small Explorer (SMEX) series and uses a much simpler set of attitude sensors. This paper centers on algorithm and design concepts for a multimission system and discusses flight experience from UARS

DIESE Final Report

The DIESE program (Determination of relevant Indicators for Environmental monitoring: A Strategy for Europe) brought together seven French and British research teams, a private company and the agencies responsible for the management of water bodies of the two countries (ONEMA and the Environmental Agency) in a joint effort to document the ecotoxicological effects related to the presence of chemicals in the environment. To contribute to a better understanding and management of the environment, the program has expanded its efforts to (1) use existing knowledge, or new information acquired during the research program, to identify important biological problems affecting wildlife, (2) increase our understanding of toxicological mechanisms involved and thus be able to identify the causes of the identified dysfunctions and (3) to hone our expertise and vigilance systems in order to better monitor changes in the environment and make appropriate diagnoses. The first part of the program identified clear biological effects, and using biological tests representative of the mechanisms of action of compounds, identified the responsible compounds present in the environment. In connection with the feminization observed in many fish species in European streams, a search for estrogenic and anti-androgenic compounds was conducted. A new test identifying estrogenic compounds has been developed in roach and the ER-Calux test for anti-androgenic effects has been implemented. The results showed that, in addition to biocides such as triclosan and chlorophène, many aromatic hydrocarbon compounds are likely to disturb the physiology of living organisms by interacting with the androgen receptor. Six of these were identified in sediment extracts: benzanthrone, fluoranthene, 1,2- benzodiphenylene sulfide, benzo[a]pyrene, benz[a] anthracene, and 9-phenylcarbazole. The second part of the program aimed at documenting and understanding the mechanisms of action of chemicals leading to physiological changes. This work represents a particular challenge when dealing with molluscs, as knowledge about their physiology and endocrinology is still fragmentary. Thus, new technologies including metabolomic and transcriptomic analyses have been implemented in order to obtain a comprehensive picture of the effects on molluscs. Metabolomic research demonstrated that estrogenic compounds are able to alter the metabolism of eicosanoids and amines, while transcriptomic strategies identified genes whose expression is altered in intersex clams. Because these genes mainly appear as “male” genes, the results suggest that these profound physiological changes result from demasculinisation of male clams. Proteomic studies have also been carried out to elucidate the mechanisms of action of pollutants on fish physiology. These studies generally included a set of molecular marker measurements in an integrative and ecological perspective. The results showed that not only male fish physiology is altered but also female reproductive status is impaired. Moreover, it appeared that other alterations of the fish endocrine system, such as androgenic effects, are at work and that the immune system is also subject to chemical pressure including effects from environmental estrogens. Notably, the immune system, like the endocrine system, seems to show periods of particular sensitivity during development. Measurements on growth and on the general metabolism emphasize the importance of environmental conditions in the physiology of aquatic organisms and in particular the inter-site variability due to temperature,hypoxic conditions, and fish development strategies. They thus provide a unique perspective that allow us to better understand the context and consequences of natural conditions on the population. In a third part of the program, the research conducted had the objective of developing and testing a biomarker strategy to support the environmental management methodologies. Two lanes of specific studies have been followed. The first was to implement, over all or part of the study area, robust biomarkers to establish maps that highlight the water bodies at risk and provide information on sources of compounds and associated disturbances. The second part of the work aimed at exploring methodologies to take advantage of biomarker measurements and to integrate them in a very simple and clear index. Partial or comprehensive maps of the Channel area were produced to report the presence of mutagenic or anti-androgenic compounds in the sediments, intersex fish and clams, and imposex. These maps may remain to be completed and work will be necessary to confront this information in order to learn relevant lessons for management of the environment, a goal that the DIESE program has contributed to by providing some necessary and original information

A 1.1 to 1.9 GHz SETI Survey of the Kepler Field: I. A Search for Narrow-band Emission from Select Targets

We present a targeted search for narrow-band (< 5 Hz) drifting sinusoidal radio emission from 86 stars in the Kepler field hosting confirmed or candidate exoplanets. Radio emission less than 5 Hz in spectral extent is currently known to only arise from artificial sources. The stars searched were chosen based on the properties of their putative exoplanets, including stars hosting candidates with 380 K > T_eq > 230 K, stars with 5 or more detected candidates or stars with a super-Earth (R_p 50 day orbit. Baseband voltage data across the entire band between 1.1 and 1.9 GHz were recorded at the Robert C. Byrd Green Bank Telescope between Feb--Apr 2011 and subsequently searched offline. No signals of extraterrestrial origin were found. We estimate that fewer than ~1% of transiting exoplanet systems host technological civilizations that are radio loud in narrow-band emission between 1-2 GHz at an equivalent isotropically radiated power (EIRP) of ~1.5 x 10^21 erg s^-1, approximately eight times the peak EIRP of the Arecibo Planetary Radar, and we limit the the number of 1-2 GHz narrow-band-radio-loud Kardashev type II civilizations in the Milky Way to be < 10^-6 M_solar^-1. Here we describe our observations, data reduction procedures and results.Comment: Accepted to the Astrophysical Journa

G28.17+0.05: An unusual giant HI cloud in the inner Galaxy

New 21 cm HI observations have revealed a giant HI cloud in the Galactic plane that has unusual properties. It is quite well defined, about 150 pc in diameter at a distance of 5 kpc, and contains as much as 100,000 Solar Masses of atomic hydrogen. The outer parts of the cloud appear in HI emission above the HI background, while the central regions show HI self-absorption. Models which reproduce the observations have a core with a temperature <40 K and an outer envelope as much as an order of magnitude hotter. The cold core is elongated along the Galactic plane, whereas the overall outline of the cloud is approximately spherical. The warm and cold parts of the HI cloud have a similar, and relatively large, line width of approximately 7 km/s. The cloud core is a source of weak, anomalously-excited 1720 MHz OH emission, also with a relatively large line width, which delineates the region of HI self-absorption but is slightly blue-shifted in velocity. The intensity of the 1720 MHz OH emission is correlated with N(H) derived from models of the cold core. There is 12CO emission associated with the cloud core. Most of the cloud mass is in molecules, and the total mass is > 200,000 Solar Masses. In the cold core the HI mass fraction may be 10 percent. The cloud has only a few sites of current star formation. There may be about 100 more objects like this in the inner Galaxy; every line of sight through the Galactic plane within 50 degrees of the Galactic center probably intersects at least one. We suggest that G28.17+0.05 is a cloud being observed as it enters a spiral arm and that it is in the transition from the atomic to the molecular state.Comment: 35 pages, inludes 12 figure

Effects of circadian rhythm phase alteration on physiological and psychological variables: Implications to pilot performance (including a partially annotated bibliography)

The effects of environmental synchronizers upon circadian rhythmic stability in man and the deleterious alterations in performance and which result from changes in this stability are points of interest in a review of selected literature published between 1972 and 1980. A total of 2,084 references relevant to pilot performance and circadian phase alteration are cited and arranged in the following categories: (1) human performance, with focus on the effects of sleep loss or disturbance and fatigue; (2) phase shift in which ground based light/dark alteration and transmeridian flight studies are discussed; (3) shiftwork; (4)internal desynchronization which includes the effect of evironmental factors on rhythmic stability, and of rhythm disturbances on sleep and psychopathology; (5) chronotherapy, the application of methods to ameliorate desynchronization symptomatology; and (6) biorythm theory, in which the birthdate based biorythm method for predicting aircraft accident susceptability is critically analyzed. Annotations are provided for most citations

A Spectroscopic Study of the Environments of Gravitational Lens Galaxies

(Abridged) We present the first results from our spectroscopic survey of the environments of strong gravitational lenses. The lens galaxy belongs to a poor group of galaxies in six of the eight systems in our sample. We discover three new groups associated with the lens galaxies of BRI 0952-0115 (five members), MG 1654+1346 (seven members), and B2114+022 (five members). We more than double the number of members for another three previously known groups around the lenses MG 0751+2716 (13 total members), PG 1115+080 (13 total members), and B1422+231 (16 total members). We determine the kinematics of the six groups, including their mean velocities, velocity dispersions, and projected spatial centroids. The velocity dispersions of the groups range from 110 +170, -80 to 470 +100, -90 km/s. In at least three of the lenses -- MG0751, PG1115, and B1422 -- the group environment significantly affects the lens potential. These lenses happen to be the quadruply-imaged ones in our sample, which suggests a connection between image configuration and environment. The lens galaxy is the brightest member in fewer than half of the groups. Our survey also allows us to assess for the first time whether mass structures along the line of sight are important for lensing. We first show that, in principle, the lens potential may be affected by line-of-sight structures over a wide range of spatial and redshift offsets from the lens. We then quantify real line-of-sight effects using our survey and find that at least four of the eight lens fields have substantial interloping structures close in projection to the lens, and at least one of those structures (in the field of MG0751) significantly affects the lens potential.Comment: Accepted for publication in the Astrophysical Journal. Figure 6 posted as a JPEG image. Requires emulateapj.st

Computational, Integrative, and Comparative Methods for the Elucidation of Genetic Coexpression Networks

Gene expression microarray data can be used for the assembly of genetic coexpression network graphs. Using mRNA samples obtained from recombinant inbred Mus musculus strains, it is possible to integrate allelic variation with molecular and higher-order phenotypes. The depth of quantitative genetic analysis of microarray data can be vastly enhanced utilizing this mouse resource in combination with powerful computational algorithms, platforms, and data repositories. The resulting network graphs transect many levels of biological scale. This approach is illustrated with the extraction of cliques of putatively coregulated genes and their annotation using gene ontology analysis and cis-regulatory element discovery. The causal basis for coregulation is detected through the use of quantitative trait locus mapping

Rapid and reversible impairment of episodic memory by a high-fat diet in mice.

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. This work was supported by an EASTBIO BBSRC PhD studentship to F.H.M., L.M.W., C.G., A.C.M., G.W.H. and F.M.C. are supported by Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS).Peer reviewedPublisher PD

Towards model-based control of Parkinson's disease

Modern model-based control theory has led to transformative improvements in our ability to track the nonlinear dynamics of systems that we observe, and to engineer control systems of unprecedented efficacy. In parallel with these developments, our ability to build computational models to embody our expanding knowledge of the biophysics of neurons and their networks is maturing at a rapid rate. In the treatment of human dynamical disease, our employment of deep brain stimulators for the treatment of Parkinson’s disease is gaining increasing acceptance. Thus, the confluence of these three developments—control theory, computational neuroscience and deep brain stimulation—offers a unique opportunity to create novel approaches to the treatment of this disease. This paper explores the relevant state of the art of science, medicine and engineering, and proposes a strategy for model-based control of Parkinson’s disease. We present a set of preliminary calculations employing basal ganglia computational models, structured within an unscented Kalman filter for tracking observations and prescribing control. Based upon these findings, we will offer suggestions for future research and development

A low H I column density filament in NGC 2403 : signature of interaction or accretion

Date of acceptance: 12/07/2014Observed H i accretion around nearby galaxies can only account for a fraction of the gas supply needed to sustain the currently observed star formation rates. It is possible that additional accretion occurs in the form of low column density cold flows, as predicted by numerical simulations of galaxy formation. To constrain the presence and properties of such flows, we present deep H i observations obtained with the NRAO Green Bank Telescope of an area measuring 4° × 4° around NGC 2403. These observations, with a 5σ detection limit of 2.4 × 1018 cm-2 over a 20 km s-1 linewidth, reveal a low column density, extended cloud outside the main H i disk, about 17′ (~ 16 kpc or ~ 2 R25) to the NW of the center of the galaxy. The total H i mass of the cloud is 6.3 × 106 M⊙, or 0.15 percent of the total H i mass of NGC 2403. The cloud is associated with an 8 kpc anomalous-velocity H i filament in the inner disk, that was previously observed in deep VLA observations. We discuss several scenarios for the origin of the cloud, and conclude that it is either accreting from the intergalactic medium, or is the result of a minor interaction with a neigboring dwarf galaxyPeer reviewe