Performance Analysis and Electromagnetic Compatibility of a Novel Wideband Radio Frequency Remote Sensing Payload

The increase in scale, complexity, and sensitivity of small satellite radio frequency payloads presents challenges in spacecraft level environmental performance testing. The Space Flight Laboratory is developing a novel wideband radio frequency payload for use on multiple satellites as part of a distributed remote sensing system. Qualification of this payload at the spacecraft level is complicated by the range of frequencies requiring analysis, the variety of received signal types, and having to qualify the payload on multiple satellites with differing configurations. This paper presents the system level radio frequency performance testing framework developed to efficiently qualify this new payload consistently in different bus configurations. The goals of this framework were to reliably determine payload receiver performance with frequencies ranging from VHF to X-band, evaluate the impacts of electromagnetic interference, and automate the electromagnetic compatibility and performance test processes such that they could be efficiently run on multiple satellites. Ultimately, this framework has yielded the ability to characterize the performance of a complex wideband radio frequency payload, and efficiently scale that characterization to a fleet of spacecraft

Solitons and Quasielectrons in the Quantum Hall Matrix Model

We show how to incorporate fractionally charged quasielectrons in the finite quantum Hall matrix model.The quasielectrons emerge as combinations of BPS solitons and quasiholes in a finite matrix version of the noncommutative $\phi^4$ theory coupled to a noncommutative Chern-Simons gauge field. We also discuss how to properly define the charge density in the classical matrix model, and calculate density profiles for droplets, quasiholes and quasielectrons.Comment: 15 pages, 9 figure

Policy, competence and participation: empirical evidence for a multilevel health promotion model

This paper uses data from a European health promotion evaluation study (MAREPS) to empirically test some fundamental assumptions of health promotion theory. Analysis shows that both the competence of individual actors and the opportunities provided for by health-promoting policies are significant predictors of participation in health promotion action. It also demonstrates effects of health promotion values on such action. Moreover, people's perception of their own political efficacy, e.g. their influence on community decisions that effect their health, turns out to be a significant predictor of self-rated health. In conclusion, the paper encourages further research to investigate the effectiveness of health-promoting policy strategies within a multilevel health promotion framework. As the present results indicate, effective health-promoting policies may create opportunities that enable individuals and communities to increase control over the determinants of health, and thereby improve their healt

Self reported physical activity, public health, and perceived environment: results from a comparative European study

The focus of physical activity promotion is moving from methods for increasing health enhancing physical activity on the individual level to higher level strategies including environmental and policy approaches. Scientific inquiry, traditionally related to individual-based strategies, requires adaptation and refinement when environmental and policy changes become more relevant. The objective of this study is to investigate the significance for behaviour and health of community-based environments that encourage physical activity. DESIGN AND SETTING The article presents data and results from a cross sectional comparative survey of the general population in six European countries (Belgium, Finland, Germany (East and West), Netherlands, Spain, Switzerland). Specifically, the relation between perceived community-based opportunities for physical activity, self reported physical activity, and self rated health status is investigated. PARTICIPANTS Representative samples of general populations (adults 18 years or older). Overall response rate: 53.5%. Sample sizes realised: Belgium: n=389; Finland: n=400; Germany (East): n = 913; Germany (West): n=489; Netherlands: n=366; Spain: n=380; Switzerland: n=406. MAIN RESULTS Analyses show that best opportunities are reported by people who are lightly to moderately physically active. People's self rated health is moderately, but significantly associated with both perceived opportunities, and physical activity itself. These predictors interact in that especially for women, the health impact of physical activity is more pronounced in case of good opportunities. CONCLUSIONS The paper shows the potential of opportunities within residential and community environments with regard to physical activity, both for behaviour and health. Opportunities may enable the population, especially women, to develop an active lifestyle, and thus improve their health. Future studies with objective indicators for physical activity related environments should test the findings that are based on perceptions

Transforming Growth Factor-b2 Induces Synthesis and Secretion of Endothelin-1 in Human Trabecular Meshwork Cells

PURPOSE. Analysis of aqueous humor from patients with primary open-angle glaucoma (POAG) revealed marked increases in the content of endothelin-1 (ET-1) and transforming growth factor-beta (TGF-b). We determined the consequences of TGF-b signaling on ET-1 expression and secretion by human trabecular meshwork (TM) cells. METHODS. Primary or transformed (NTM5 and GTM3) human TM cells conditioned in serum-free media were incubated in the absence or presence of TGF-b1 or -b2. Relative changes in preproendothelin (ppET)-1 mRNA content and secreted ET-1 peptide were quantified by real-time PCR and ELISA, respectively. In some experiments, TGF-b or ET-1 receptor antagonists, or Rho G-protein inhibitors, were evaluated for effects on TGF-b signaling. Filamentous actin organization was visualized by phalloidin. RESULTS. Primary or transformed human TM cells cultured in the presence of TGF-b1 or -b2 exhibit a marked (>8-fold) increase in ppET-1 mRNA content compared to vehicle controls. Coincubation with SB-505124, an inhibitor of TGFbRI/ALK-5 signaling, prevented TGF-b-mediated ppET-1 mRNA expression. In contrast, coincubation with ET A or ET B (BQ-788) receptor antagonists had no effect on TGF-b-mediated ppET-1 mRNA expression. TGF-b1 and -b2 each elicited a robust (>7-fold) secretion of ET-1 while enhancing stress fiber organization. Inhibition of Rho signaling attenuated TGF-b-mediated increases in ppET-1 mRNA content, ET-1 secretion, and stress fiber organization. CONCLUSIONS. TGF-b, signaling through the TGFbRI/ALK-5 receptor, elicits marked increases in ET-1 mRNA content and ET-1 secretion from cultured primary or transformed human TM cells. Elevated levels of TGF-b2 present in AH of POAG patients may elevate intraocular pressure, in part, by eliciting aberrant Rho G-protein dependent cell contraction, and increasing ET-1 synthesis and secretion, in human TM cells. (Invest Ophthalmol Vis Sci. 2012;53:5279-5286) DOI:10.1167/iovs.11-9289 P rimary open-angle glaucoma (POAG) is one of the most common causes of blindness worldwide, affecting over 2 million individuals 45 years or older in the United States. 1 In POAG patients, irreversible loss of peripheral vision frequently is associated with a pathologic elevation of intraocular pressure (IOP). 2 Clinically, elevated IOP remains a poorly understood hallmark of POAG. In healthy eyes, normal IOP is maintained through a balance between production and outflow of aqueous humor (AH). In adults, the majority (>50%) of AH exits the eye by a conventional outflow pathway involving the trabecular meshwork (TM) at the iridocorneal angle. 3 TM cells regulate AH outflow facility partly through contraction and relaxation of their actin cytoskeleton. Under pathologic conditions, chronic aberrant contraction of TM cells increases resistance to AH outflow, leading to abnormal and sustained elevation of IOP. The mechanism that promotes harmful chronic aberrant TM cell contraction in POAG remains unknown, but may involve dysregulation of small monomeric Rho G-protein mediated organization of the actin cytoskeleton. 23-26 Levels of transforming growth factor (TGF)-b2, a cytokine known to promote synthesis and release of ECM components, similarly are increased aberrantly in AH from POAG patients. 41 Emerging evidence strongly supports a pathologic association between either ET-1 or TGF-b2 with elevated IOP in the 5279 Downloaded from iovs.arvojournals.org on 06/29/2019 pathogenesis of POAG. Mechanisms responsible for regulating endogenous synthesis and secretion of ET-1 and TGF-b2 within the eye currently remain unknown. A role for TGF-b in promoting transcription and release of ET-1 has been suggested. MATERIALS AND METHODS Human Trabecular Meshwork Cell Culture The use of human cadaver material in our study was approved by the Edward Hines Jr. VA and Loyola University Chicago institutional review boards in compliance with the tenets of the Declaration of Helsinki. Fresh cadaver corneoscleral rims were obtained (Illinois Eye Bank, Chicago, IL) at the time of corneal transplant and primary human TM cells were prepared using a collagenase-free procedure as described previously. Treatment Subconfluent primary or transformed human TM cells were cultured for 24 hours in serum-free media before treatment. Recombinant human TGF-b1 or TGF-b2 (Cell Signaling Technology, Danvers, MA) was reconstituted as a stock solution in 4 mM HCl containing 0.1% BSA for 30 minutes at 238C before use. Serum-starved cultures were treated (24 hours) in the absence (vehicle, 200 nM HCl) or presence (5 ng/mL) of TGF-b1 or TGF-b2 in fresh serum-free media. TM cell viability was routinely determined by Trypan Blue dye exclusion and was consistently >90%. To determine mechanism of action, GTM3 cells were co-treated (24 hours) with TGF-b2 (5 ng/mL) in the absence or presence of SB-505124 (1 lM), a TGF-b type I receptor (TGFbRI)/ activin receptor-like kinase 5 (ALK-5) inhibitor; BQ-123 (1 lM), an ET A antagonist; or BQ-788 (1 lM), an ET B antagonist. To determine the role of Rho G-proteins, TM cells were pretreated (1 hour) with chemicallyactivated lovastatin (10 lM) 3,48,50 ; GGTI-298 (10 lM, a geranylgeranyl transferase-I inhibitor) or with cell-permeable exoenzyme C3 transferase (10 lg /mL, a selective Rho G-protein subfamily inhibitor; Cytoskeleton, Denver, CO). Unless otherwise indicated, all reagents were purchased from Sigma-Aldrich. Real Time RT-PCR Total RNA was extracted from primary or transformed human TM cells using TRIzol reagent, and 5 lg were reverse-transcribed using Super Script III First Strand Synthesis system (Life Technologies) as described previously. Endothelin-1 ELISA The content of ET-1 in cell culture media was assessed using a commercially-available ELISA kit (R&D Systems, Minneapolis, MN) according to manufacturer's instructions. The working range for this human-specific ET-1 ELISA kit is 0.39-25 pg/ml. Media from primary or transformed human TM cells cultured in 12-well cell culture plates were harvested, centrifuged (700g 3 5 minutes) to remove particulate, and aliquots (75 lL) were added to microtiter wells precoated with a monoclonal antibody against human ET-1. Samples were read at 450 nm with a 540 nm correction, and results expressed as pg of ET-1. Filamentous Actin Staining NTM5 or GTM3 cells were cultured on Nunc Lab-Tek II chambered slides overnight (24 hours) in serum-free DMEM and treated 3 24 hours without (vehicle, 200 nM HCl) or with 5 ng/mL TGF-b1 or TGF-b2. Some cultures were pretreated (1 hour) with chemically-activated lovastatin (10 lM) or GGTI-298 (10 lM) before TGF-b2 treatment. Treated cells were fixed 315 minutes at 238C by immersion in phosphate buffered (pH 7.4) 4% paraformaldehyde. Filamentous actin stress fiber organization was visualized using AlexaFluor488-conjugated phalloidin. Stained slides were mounted using Fluoroshield containing DAPI (Sigma), and visualized by confocal microscopy. Statistical Analysis Results are expressed as mean 6 SD of duplicate (primary) or triplicate (transformed) cultures, repeated at least one additional time unless otherwise specified. Parametric data were analyzed by Student's t-test or by one-way ANOVA followed by either a Dunnett's or Bonferroni's multiple comparison post-hoc analysis, as indicated. In all cases, P < 0.05 was considered statistically significant. RESULTS TGF-b2 Increases ppET-1 mRNA Content Transformed human TM cells (NTM5) conditioned overnight in serum-free media and incubated subsequently for 24 hours in the presence of TGF-b2 (5 ng/mL) exhibited a >8-fold increase in ppET-1 mRNA content compared to vehicle-treated controls The effect of TGF-b2 on relative changes in ppET-1 mRNA content was dose-and time-dependent 39,51-53 GTM3 cells also responded to 5 ng/mL TGF-b2 stimulation in a time-dependent 5280 Von Zee et al. IOVS, August 2012, Vol. 53, No. 9 Downloaded from iovs.arvojournals.org on 06/29/2019 manner, exhibiting significant and sustained changes in ppET-1 mRNA content at 6-12 hours of incubation 44 Pretreating TM cells with SIS3, a specific inhibitor of the canonical TGF-b effector Smad3, however, did not reduce TGFb2 enhanced ppET-1 mRNA expression (data not shown), suggesting the involvement a non-canonical TGF-b signaling pathway. Previously, a role for small monomeric G-proteins in the regulation of ppET-1 expression has been suggested. One mechanism by which statins indirectly inhibit small Gprotein signaling in TM cells is by limiting the availability of isoprenoid intermediates required for post-translational modification and activation of Rho G-proteins

Gas-phase reactions of carbon cluster ions with isomeric chloropropenes

Sun J, Grützmacher H-F, Lifshitz C. Gas-phase reactions of carbon cluster ions with isomeric chloropropenes. International Journal of Mass Spectrometry and Ion Processes. 1994;138:49-61.Gas-phase ion/molecule reactions of carbon cluster ions (C-n(.+), n = 10-20) with allylchloride (AC) and 2-chloro-propene (CP) were investigated by Fourier transform ion cyclotron resonance spectrometry (FT-ICR). The carbon cluster ions C-n(.+) were generated by electron impact ionization of perchloroarenes and subsequent elimination of all Cl substituents from the molecular ion giving rise to monocyclic C-n(.+). Clear pseudo-first-order reactions were observed for the carbon cluster ions C-n(.+) thus formed without any sign of isomeric clusters of different reactivity. An exception is C-11(.+), for which a small amount of unreactive ions was observed. The reactions of C-n(.+) with AC and CP at low operating pressure (1.2 x 10(-8)-8.0 x 10(-7) mbar) yield product ions Cn+3H5+ by loss of Cl from an intermediate adduct. Rate constants for the reactions with CP are always distinctly larger than with AC in spite of the smaller dissociation energy of the C-Cl bond in AC. Exceptionally large reaction efficiencies are found for C-13(.+) and C-17(.+), corroborating the high reactivity of cyclic anti-aromatic C-n(.+) with n = 4r + 1. The nature of the reaction products depends on the number of carbon atoms in C-n(.+). Secondary reactions of primary product ions Cn+3H5+ were observed only for reactions of odd numbered C-13(.+) and C-17(.+). Further, on collision induced dissociation (CID) the product ions from even C-n(.+) yield exclusively C3H3+, while product ions from odd C-n(.+) generate several fragment ions by loss of H and of C-(2-4)H-2. A reaction model explaining these observations is proposed

Adaptive Optimization of Wave Functions for Fermion Lattice Models

We present a simulation algorithm for Hamiltonian fermion lattice models. A guiding trial wave function is adaptively optimized during Monte Carlo evolution. We apply the method to the two dimensional Gross-Neveu model and analyze systematc errors in the study of ground state properties. We show that accurate measurements can be achieved by a proper extrapolation in the algorithm free parameters.Comment: 4 pages, 6 figures (Encapsulated PostScript

Lorentz breaking Effective Field Theory and observational tests

Analogue models of gravity have provided an experimentally realizable test field for our ideas on quantum field theory in curved spacetimes but they have also inspired the investigation of possible departures from exact Lorentz invariance at microscopic scales. In this role they have joined, and sometime anticipated, several quantum gravity models characterized by Lorentz breaking phenomenology. A crucial difference between these speculations and other ones associated to quantum gravity scenarios, is the possibility to carry out observational and experimental tests which have nowadays led to a broad range of constraints on departures from Lorentz invariance. We shall review here the effective field theory approach to Lorentz breaking in the matter sector, present the constraints provided by the available observations and finally discuss the implications of the persisting uncertainty on the composition of the ultra high energy cosmic rays for the constraints on the higher order, analogue gravity inspired, Lorentz violations.Comment: 47 pages, 4 figures. Lecture Notes for the IX SIGRAV School on "Analogue Gravity", Como (Italy), May 2011. V.3. Typo corrected, references adde

Degradation of azo dye (Acid orange 7) in a microbial fuel cell: comparison between anodic microbial-mediated reduction and cathodic laccase-mediated oxidation

More than 80 per cent of wastewater from industries is discharged into receiving water bodies without any pollution control. Microbial fuel cells (MFCs) are a promising technology for the simultaneous treatment of wastewater and electricity production. With regard to azo-dye containing wastewater (e.g. from textile manufacturing), the dye may be fed via the anode chamber containing electrochemically active bacteria or via the cathode chamber containing laccase enzyme as catalyst for oxygen reduction. This study investigated which of the two approaches is the best with regard to rate of decolourization of the dye (Acid orange 7), COD reduction and electricity production. The power density was higher for the MFCDye cathode (50±4 mW m-2, COD reduction 80.4±1.2%) compared with 42.5±2.6 mW m-2 (COD reduction 69±2%) for MFCDye anode. The time required for decolourization was longer in the MFCDye anode (Shewanella oneidensis) where only 20% decolourization was obtained after 24 h compared to 80% for the MFCDye cathode. The anodic dye degradation products were unstable when exposed to air resulting in regaining of colour. In case of degradation by laccase in the cathode chamber, the decolourization products were stable and simpler in chemical structure as determined by GC-MS. This work suggests that feeding azo dyes in cathode chambers of MFCs containing laccase is a better way of treating the dyes compared to the commonly used approach of feeding the dye in the anode chamber provided enzyme activity can be sustained