Attitude Determination and Control for the Multi-Mission Space Payload Platform (SPP)

The first artificial satellite, Sputnik, was a smallsat of sort with its 58 cm. diameter and mass of just under 84 kg. Since then, design trends have produced progressively larger spacecraft tracking the launch vehicle throw capabilities. This approach, however, is being challenged today and, although large satellites will continue to meet global requirements cost effectively, there is a need to accommodate specific payloads with smaller spacecraft buses. The economy of scale that called for larger satellites in the past, is now focusing on a multi-mission design approach. A general purpose spacecraft bus can be designed to support a wide range of payloads: meteorological, surveillance, communication, and scientific. General Electric Astro Space has developed such a reliable and cost effective vehicle, the Space Payload Platform (Photo 1), with a common core bus weighing 130 kg. (dry weight), available in both spin-stabilized and three-axis stabilized configurations. Compatible with both Air Launch Vehicle (ALV-Pegasus) and Standard Small Launch Vehicle (SSLV-Taurus), the SPP allows up to a 300 kg, 260 Watt payload to be injected directly into a low altitude circular or elliptic orbit. This basic capability can be augmented by an on-board hydrazine propulsion system to achieve, correct, and/or maintain higher altitude orbits. To accommodate these various programs, a flexible Attitude Determination and Control System (ADACS) has been implemented such that only a minimum of alterations are required for different missions. In this paper, we shall explore ADACS design approach for several configuration options

Furosemide kinetics and dynamics after kidney transplant

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110005/1/cptclpt1981134.pd

Understanding fixed effects in human well-being

In studies of subjective well-being, economists and other researchers typically use a fixed or random effect estimation to control for unobservable heterogeneity across individuals. Such individual heterogeneity, although substantially reducing the estimated effect of many characteristics, is little understood. This paper shows that personality measures can account for 20% of this heterogeneity and a further 13% can be accounted for by other observable between-person information. This paper then demonstrates that the use of personality measures, in a new technique developed by [Plumper, T., Troeger, V.E. (2007). Efficient estimation of time-invariant and rarely changing variables in finite sample panel analyses with unit fixed effects, Political Analysis, 15(2), 124-139.], can help researchers obtain improved estimates for important characteristics such as marital status, disability and income. The paper argues that this has important practical implications

ICTV Virus Taxonomy Profile: Pospiviroidae

[EN] Members of the family Pospiviroidae have single-stranded circular RNA genomes that adopt a rod-like or a quasi-rod-like conformation. These genomes contain a central conserved region that is involved in replication in the nucleus through an asymmetric RNA-RNA rolling-circle mechanism. Members of the family Pospiviroidae lack the hammerhead ribozymes that are typical of viroids classified in the family Avsunviroidae. The family Pospiviroidae includes the genera Apscaviroid, Cocadviroid, Coleviroid, Hostuviroid and Pospiviroid, with >25 species. This is a summary of the ICTV Report on the family Pospiviroidae, which is available at ictv.global/report/pospiviroidae.Production of this summary, the online chapter, and associated resources was funded by a grant from the Wellcome Trust (WT108418AIA).Di Serio, F.; Owens, RA.; Li, S.; Matousek, J.; Pallás Benet, V.; Randles, JW.; Sano, T.... (2021). ICTV Virus Taxonomy Profile: Pospiviroidae. Journal of General Virology. 102(2):1-2. https://doi.org/10.1099/jgv.0.00154312102

Zampanolida, un novedoso agente estabilizador de microtubulos quew se une covalentemente al sitio de paclitaxel

Trabajo presentado en el XI Congreso de la Sociedad de Biofísica de España: "XXV años y más allá", celebrado en Murcia (España) , del 1 al 4 de junio de 201

Does intergroup contact predict personality? A longitudinal study on the bidirectional relationship between intergroup contact and personality traits

We conducted a longitudinal study to test whether, in addition to being predicted by personality, intergroup contact is longitudinally associated with personality traits. Participants were 388 majority (Italian) and 109 minority (immigrant) first-year highschool students. Results revealed a bidirectional relationship between contact and personality: quality of contact was longitudinally associated with greater agreeableness and openness to experience, while agreeableness and openness to experience were longitudinal predictors of contact quality. An unexpected negative longitudinal association also emerged between quantity of contact and agreeableness. These effects were not moderated by group of belonging (majority vs. minority). Our findings highlight the importance of integrating research on intergroup contact with research on personality

Web-based Indicated Prevention of Common Mental Disorder in University Students in Four European Countries - Study Protocol for a Randomised Controlled Trial

Abstract Background Mental disorders and their symptoms are highly prevalent in the university student population, and the transition from secondary to tertiary education is associated with a rise in mental health problems. Existing web-based interventions for the prevention of common mental disorders in student populations often focus on just one disorder and have not been designed specifically for students. There is thus a need for transdiagnostic, student-specific preventative interventions that can be widely disseminated. This two-arm, parallel group randomised controlled trial aims to evaluate the effectiveness and cost-effectiveness of a web-based transdiagnostic mental health problem prevention programme (PLUS) across several universities in four countries. Method Students (N = 5550) will be recruited through a variety of channels and asked to complete a personality assessment to determine whether they are at high risk for developing common mental disorders. Students at high risk will be randomly allocated to either PLUS or a control intervention, which provides practical support around issues commonly experienced at university. Students at low risk will be allocated to the control intervention. Both intervention groups will be assessed at baseline, 4 weeks, 3 months, 6 months and 12 months after randomisation. Depression and generalised anxiety, assessed using the Patient Health Questionnaire and the Generalised Anxiety Disorder scales, will form the primary outcomes in this study. Secondary outcome measures include alcohol and drug use, eating behaviour, self-esteem, and quality of life. The cost-effectiveness of the intervention will also be evaluated. Conclusions This study will contribute to understanding the role of transdiagnostic indicated web-based interventions for the prevention of common mental disorders in university students. It will also be one of the first studies to investigate the cost-effectiveness of such interventions

Pharmacokinetics of orally administered acetaminophen in man

Average and individual sets of plasma concentration-time data for acetaminophen following two oral treatments were simultaneously fitted to the integrated equation describing the two-compartment open model with first-order absorption and lag time. The nonlinear least-squares program NONLIN and an IBM 360/67 digital computer were employed to estimate nine parameters (k A , k B , C A 0 , C B 0 , k 12 , k 21 , k el , and ). When the mean plasma concentrations were weighted according to the inverse of their variances, the parameter estimates more accurately reflected those for individual subjects in the disposition portion of the model. Depending on the relative magnitudes of the disposition rate constants (k 12 , k 21 , and k el ), the one-compartment open model can be used to predict equilibrium-state plasma levels even though the drug is really “two compartment.” Equations are presented which show when the one-compartment approximation is justified. Equations are also presented for calculation of loading doses for multiple dose regimens of any drug obeying the two-compartment open model and the equations are applied to acetaminophen .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45044/1/10928_2005_Article_BF01071309.pd

Impact of the Herbal Medicine Sophora flavescens on the Oral Pharmacokinetics of Indinavir in Rats: The Involvement of CYP3A and P-Glycoprotein

Sophora flavescens is a Chinese medicinal herb used for the treatment of gastrointestinal hemorrhage, skin diseases, pyretic stranguria and viral hepatitis. In this study the herb-drug interactions between S. flavescens and indinavir, a protease inhibitor for HIV treatment, were evaluated in rats. Concomitant oral administration of Sophora extract (0.158 g/kg or 0.63 g/kg, p.o.) and indinavir (40 mg/kg, p.o.) in rats twice a day for 7 days resulted in a dose-dependent decrease of plasma indinavir concentrations, with 55%–83% decrease in AUC0-∞ and 38%–78% reduction in Cmax. The CL (Clearance)/F (fraction of dose available in the systemic circulation) increased up to 7.4-fold in Sophora-treated rats. Oxymatrine treatment (45 mg/kg, p.o.) also decreased indinavir concentrations, while the ethyl acetate fraction of Sophora extract had no effect. Urinary indinavir (24-h) was reduced, while the fraction of indinavir in faeces was increased after Sophora treatment. Compared to the controls, multiple dosing of Sophora extract elevated both mRNA and protein levels of P-gp in the small intestine and liver. In addition, Sophora treatment increased intestinal and hepatic mRNA expression of CYP3A1, but had less effect on CYP3A2 expression. Although protein levels of CYP3A1 and CYP3A2 were not altered by Sophora treatment, hepatic CYP3A activity increased in the Sophora-treated rats. All available data demonstrated that Sophora flavescens reduced plasma indinavir concentration after multiple concomitant doses, possibly through hepatic CYP3A activity and induction of intestinal and hepatic P-gp. The animal study would be useful for predicting potential interactions between natural products and oral pharmaceutics and understanding the mechanisms prior to human studies. Results in the current study suggest that patients using indinavir might be cautioned in the use of S. flavescens extract or Sophora-derived products

Pharmaceutical Metabolism in Fish: Using a 3-D Hepatic In Vitro Model to Assess Clearance

At high internal doses, pharmaceuticals have the potential for inducing biological/pharmacological effects in fish. One particular concern for the environment is their potential to bioaccumulate and reach pharmacological levels; the study of these implications for environmental risk assessment has therefore gained increasing attention. To avoid unnecessary testing on animals, in vitro methods for assessment of xenobiotic metabolism could aid in the ecotoxicological evaluation. Here we report the use of a 3-D in vitro liver organoid culture system (spheroids) derived from rainbow trout to measure the metabolism of seven pharmaceuticals using a substrate depletion assay. Of the pharmaceuticals tested, propranolol, diclofenac and phenylbutazone were metabolised by trout liver spheroids; atenolol, metoprolol, diazepam and carbamazepine were not. Substrate depletion kinetics data was used to estimate intrinsic hepatic clearance by this spheroid model, which was similar for diclofenac and approximately 5 fold higher for propranolol when compared to trout liver microsomal fraction (S9) data. These results suggest that liver spheroids could be used as a relevant and metabolically competent in vitro model with which to measure the biotransformation of pharmaceuticals in fish; and propranolol acts as a reproducible positive control