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Performance of an EKF-based Orbit Determination (OD) algorithm using Global Positioning System (GPS) measurements is examined under erroneous observation conditions. A generalized formulation of a dynamic orbit model is designed to predict the satellite states in an Earth-Centered Earth-Fixed (ECEF) frame. A suitable orbit interpolation method is then chosen for interpolating the GPS satellite position at the measurement time tag before finding the geometric range between the GPS and the LEO satellites. Thereafter, the commonly used Extended Kalman Filter (EKF) algorithm is implemented for the nonlinear OD problem. The proposed algorithm is tested for the precision in OD of two LEO satellites, namely GRACE and Megha-Tropiques based on the available raw GPS measurements in the Receiver Independent Exchange (RINEX) observation files. For the GRACE satellite, the efficacy of the present OD algorithm is validated by comparing the estimated and publicly available precise orbit information. The Megha-Tropiques satellite, however, does not have precise orbit information. Furthermore, it is observed that the RINEX file has several erroneous observations as detected by the Fault Detection and Exclusion (FDE) algorithm in-built in the OD algorithm. A comparison of the estimated satellite position with that obtained from the standard software GNSS-Lab Tool (gLAB) shows that the accuracy of the position estimates varies proportionally with the number of erroneous observations of the Megha-Tropiques satellite.

AbstractBackground:Medication adherence is critical for success of clinical trials.Objective:To assess oral riboflavin is an adherence marker.Methods:Riboflavin was incorporated into active treatment and placebo pills for a clinical trial lasting for 2 years.Results:The accuracy (area under the receiver operating curve) of urinary riboflavin was 0.91 as a binary classifier of adherence, and was similar or better than for two active study ingredients daidzein (0.92) and genistein (0.87) (all p < 0.0001). Decreased adherence over time was similar in the two study groups.Conclusion: Riboflavin is an accurate and useful biomarker for study pill ingestion.

Inductively coupled plasma-mass spectrometry (ICP-MS) is a powerful tool for both quantitative multielement analyses of inorganic elements and measurement of isotope ratios (IRs). The main disadvantage of this technique is the existence of polyatomic isobaric interferences at some key masses. Zinc has been investigated for such potential interferences in serum or plasma. The Zn isotopes,66Zn and68Zn, have no apparent interferences, but32S16O2and32S2are isobaric with64Zn. The possible effects of S and other major components of blood plasma—Na, K, Cl, P, Ca—on Zn IRs were investigated using a series of mineral solutions which simulated human plasma with respect to these elements. The mixture of all mineral elements interfered only with64Zn (6.66 ng/mL) and70Zn (8.51 ng/mL). Interferences to66Zn,67Zn, and68Zn were minimal containing 0.90, 0.94, and 0.39 ng/mL, respectively. The copresence of Na or S shifted35Cl16O2(atomic mass 67 coming from Cl solution) to35Cl2which reduced the contribution to67Zn. The hypothesis that Zn IRs obtained from plasma at various intervals after the intravenous administration of enriched67Zn to humans would reflect those obtained after extraction of Zn was therefore tested. To compare the two pretreatment methods, “extraction” versus “nonextraction,” specimens were collected from 10 human subjects at intervals of 5 min to 24 h postinjection, and in 4 subjects from 5 min to 9 d postinjection. Two separate aliquots of plasma from each time-point were dried and digested with hydrogen peroxide, and the residue dissolved in nitric acid. One specimen was subjected to zinc extraction using ammonium diethyldithiocarbamate chelate followed by back extraction into nitric acid. The matching aliquot received no further pretreatment. The normalized IRs obtained from67Zn/66Zn and67Zn/68Zn in both the “extracted” and “nonextracted” samples agreed well(r2= 0.976 andr2= 0.985, respectively) compared to those from other ratios (r2= 0.838 for67Zn/64Zn andr2= 0.747 for67Zn/70Zn). Considering the minimum possibility of isobaric interferences in plasma samples,67Zn/68Zn obtained from “nonextracted” samples is sufficient for routine Zn kinetic analysis by ICP-MS.

Significant correlation in 11 different 1,4-benzodiazepinones has been established between log k2(the second order rate constant for the reduction of the ‘azepinones’ by sodium borohydride) and their ED50 against leptazol-induced seizures in mice. The results suggest a possible involvement of the carbonyl group at the receptor site.

Soybean consumption is associated with reduced rates of prostate and other cancers, possibly due in part to the presence of isoflavones. The metabolism and disposition of these soya-derived phytoestrogens after chronic soya exposure were studied on a metabolic unit in six healthy males (21-35 yrs of age) who consumed an unrestricted hospital diet and a 12-oz portion of soymilk with each meal for one month. The daily isoflavone intake was about 100 mg of daidzein (mostly as daidzin) and about 100 of mg of genistein (mostly as genistin). At two-week intervals, excretion of isoflavones in urine was studied, during which time the subjects consumed a constant basal diet for three to four days, ingested the full daily 36-oz portion of soymilk within 30 minutes each day for one to two days, and collected urine continuously. The urinary recovery of ingested daidzin plusdaidzein (46.9 ± 15.2%, mean ± SD) and genistin plus genistein (14.6 ± 9.2%) didnotchange with prolonged soya ingestion. The absorption half-lives (t1/2) for daidzein and genistein and the appearance t1/2 for equol (1 subject) were initially 1.5 ± 0.4, 1.9 ± 0.6, and 2.2 hours, respectively, and 2.5 + 1.1 (p = 0.06 compared with baseline), 1.4 ± 0.9 (p = 0.03 compared with baseline), and 4.2 hours, respectively, during one month of soymilk ingestion. The excretion t1/2 for daidzein, genistein, and equol were initially 2.9 + 0.5, 3.8 ± 0.7, and 5.2 hours, respectively, and 3.9 + 1.2 (p = 0.03), 5.5 ± 1.6 (p = 0.02), and 9.7 hours, respectively, during one month of soymilk ingestion. These results indicate that chronic soya exposure did not induce significant changes in the metabolic pathways of isoflavones but altered the time courses of daidzein and genistein excretion. Thus chronic exposure to soya might prolong the tissue exposure to the presumed biologically active free and unconjugated forms of these isoflavones and thereby enhance their oncoprotective effects.

Abstract: Formation of ternary complexes of copper(II) with thiodiglycolic acid as primary ligand(A) and glycine, α-alanine, β-alanine, serine, ethylenediamine or malonic acid as secondary ligand(B) have been investigated in aqueous solution at 30°C employing pH-metric and spectrophotometric methods. The overall formation constants of the mixed-ligand complexes have been evaluated and the relative stabilities of the complexes are compared and discussed in terms of statistical considerations, nature of the donor atoms, steric effects and charge neutralisation as also the distribution of the different complex species present in the solution as a function of pH.

The formation constants of mixed-ligand complexes with hetero donors of the type CuAB where A is a carboxylic acid such as lactic acid or oxalic acid and B is an α−or β-amino acid are studied by polarography. The mixed-ligand stabilisation constant clearly indicates the preferred formation of copper(II) mixedligand complexes with hetero donors over homo donors. The other driving forces leading to the favoured formation of mixed-ligand complexes are also discussed.

Polarographic investigation of uranyl complexes with potentially bidentate α-, β-, and γ-amino acids have been carried out. The polarographic behaviour of these complexes as a function of pH and ligand concentration has revealed the nature of binding to be unidentate carboxylate coordination in the complexes. The amino group is not involved in coordination. The relative stabilities of α-, β-, and γ-amino acid complexes are discussed.

Formation of ternary complexes of copper(II) with thiodiglycolic acid as primary ligand(A) and glycine, α-alanine, β-alanine, serine, ethylenediamine or malonic acid as secondary ligand(B) have been investigated in aqueous solution at 30°C employing pH-metric and spectrophotometric methods. The overall formation constants of the mixed-ligand complexes have been evaluated and the relative stabilities of the complexes are compared and discussed in terms of statistical considerations, nature of the donor atoms, steric effects and charge neutralisation as also the distribution of the different complex species present in the solution as a function of pH.

The title ligand (I), prepared by the condensation of o‐phenylenediamine with diacetyl monoxime, reacts to give the Co complexes (III).