561 research outputs found
Studies on the formaldehydogenic substances present in human urine
PART I. A STUDY OF FORMALDEHYDOGENIC SUBSTANCES
IN, AND THE ISOLATION OP CRYSTALLINE
COMPOUNDS FROM, EXTRACTS OF BOILED) URINE.PART II. COLD ACID-LABILE FORMALDEHYDOGENIC SUBSTANCES (FSS) IN HUMAN URINEPART III. THE ATTEMPTED ISOLATION OF TETRAHYDROCORTISONE GLUCURONOSIDE FROM NORMAL
MALE URIN
Submission to the Justice and Electoral Committee on the Search and Surveillance Bill 2009
This submission to the Justice and Electoral Select Committee of the New Zealand Parliament addresses the surveillance regime created by the Search and Surveillance Bill 2009
Structure and NMR spectra of bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylic acid and its anhydride
Two of the three published sets of 1H and 13C NMR data for bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylic anhydride have been found to actually be those of the corresponding diacid. The NMR spectroscopic distinction between these two compounds is clarified and 1JC–H values are reported for the anhydride, the diacid and a related diester. The X-ray structure of the diacid has been determined and features chains of molecules involving both intra- and inter-molecular hydrogen bonding.PostprintPeer reviewe
An emulation-based approach for interrogating reactive transport models
We present a new approach to understand the interactions among different chemical and biological processes modelled in environmental reactive transport models (RTMs) and explore how the parameterisation of these processes influences the results of multi-component RTMs. We utilize a previously published RTM consisting of 20 primary species, 20 secondary complexes, 17 mineral reactions and 2 biologically-mediated reactions which describes bio-stimulation using sediment from a contaminated aquifer. We choose a subset of the input parameters to vary over a range of values. The result is the construction of a new dataset that describes the model behaviour over a range of environmental conditions. Using this dataset to train a statistical model creates an emulator of the underlying RTM. This is a condensed representation of the original RTM that facilitates rapid exploration of a broad range of environmental conditions and sensitivities. As an illustration of this approach, we use the emulator to explore how varying the boundary conditions in the RTM describing the aquifer impacts the rates and volumes of mineral precipitation. A key result of this work is the recognition of an unanticipated dependency of pyrite precipitation on pCO2 in the injection fluid due to the stoichiometry of the microbially-mediated sulphate reduction reaction. This complex relationship was made apparent by the emulator, while the underlying RTM was not specifically constructed to create such a feedback. We argue that this emulation approach to sensitivity analysis for RTMs may be useful in discovering such new coupled sensitives in geochemical systems and for designing experiments to optimise environmental remediation. Finally, we demonstrate that this approach can maximise specific mineral precipitation or dissolution reactions by using the emulator to find local maxima, which can be widely applied in environmental systems.</p
2,6-exo-8,10-exo-4-Butyl-9-oxa-4-azatetracyclo[5.3.1.02,6.08,10]undecane-3,5-dione
The title epoxide was obtained by spontaneous epoxidation of the corresponding unsaturated imide in air or by peracid oxidation. Unambiguous assignment of the 1H and 13C NMR spectra is achieved by comparison between analogous compounds and its X-ray structure confirms the exo,exo-configuration.Publisher PDFPeer reviewe
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Modelling the Effects of Non-Steady State Transport Dynamics on the Sulfur and Oxygen Isotope Composition of Sulfate in Sedimentary Pore Fluids
We present the results of an isotope-enabled reactive transport model of a sediment column undergoing active microbial sulfate reduction to explore the response of the sulfur and oxygen isotopic composition of sulfate under perturbations to steady state. In particular, we test how perturbations to steady state influence the cross plot of δ34S and δ18O for sulfate. The slope of the apparent linear phase (SALP) in the cross plot of δ34S and δ18O for sulfate has been used to infer the mechanism, or metabolic rate, of microbial metabolism, making it important that we understand how transient changes might influence this slope. Tested perturbations include changes in boundary conditions and changes in the rate of microbial sulfate reduction in the sediment. Our results suggest that perturbations to steady state influence the pore fluid concentration of sulfate and the δ34S and δ18O of sulfate but have a minimal effect on SALP. Furthermore, we demonstrate that a constant advective flux in the sediment column has no measurable effect on SALP. We conclude that changes in the SALP after a perturbation are not analytically resolvable after the first 5% of the total equilibration time. This suggests that in sedimentary environments the SALP can be interpreted in terms of microbial metabolism and not in terms of environmental parameters.</jats:p
Coding Gene Single Nucleotide Polymorphism Mapping and Quantitative Trait Loci Detection for Physiological Reproductive Traits in Brook Charr, Salvelinus fontinalis
A linkage map of 40 linkage groups (LGs) was developed for brook charr, Salvelinus fontinalis, using an F2 interstrain hybrid progeny (n = 171) and 256 coding gene SNP developed specifically for brook charr and validated from a large (>1000) subset of putative SNP, as well as 81 microsatellite markers. To identify quantitative trait loci (QTL) related to reproduction functions, these fish were also phenotyped at six physiological traits, including spermatozoid head diameter, sperm concentration, plasma testosterone, plasma 11-keto-testosterone, egg diameter, and plasma 17β-estradiol. Five significant QTL were detected over four LGs for egg diameter and plasma 17β-estradiol concentration in females, and sperm concentration as well as spermatozoid head diameter in males. In females, two different QTLs located on LG 11 and LG 34 were associated with the egg number, whereas one QTL was associated with plasma 17β-estradiol concentration (LG 8). Their total percent variance explained (PVE) was 26.7% and 27.6%, respectively. In males, two QTL were also detected for the sperm concentration, and their PVE were estimated at 18.58% and 14.95%, respectively. The low QTL number, associated with the high PVE, suggests that the variance in these reproductive physiological traits was either under the control of one major gene or a small number of genes. The QTL associated with sperm concentration, plasma 17β-estradiol, and egg diameter appeared to be under a dominance effect, whereas the two others were under a negative additive effect. These results show that genes underlying the phenotypic variance of these traits are under different modes of action (additive vs. dominance) and may be used to predict an increase or a decrease in their phenotypic values in subsequent generations of selective breeding. Moreover, this newly developed panel of mapped SNP located in coding gene regions will be useful for screening wild populations, especially in the context of investigating the genetic impact of massive stocking of domestic brook charr to support the angling industry throughout eastern North America
Essays on river mechanics
CER92-93-PYJ-5.Presented by the Graduate Students in CE 717 - River Mechanics (Spring 1993).Includes bibliographical references.April 1993
Withdrawal of antihypertensive medication: a systematic review
Although antihypertensive medication is usually continued indefinitely, observations during wash-out phases in hypertension trials have shown that withdrawal of antihypertensive medication might be well tolerated to do in a considerable proportion of people. A systematic review was completed to determine the proportion of people remaining normotensive for 6 months or longer after cessation of antihypertensive therapy and to investigate the safety of withdrawal. The mean proportion adjusted for sample size of people remaining below each study's threshold for hypertension treatment was 0.38 at 6 months [95% confidence interval (CI) 0.37–0.49; 912 participants], 0.40 at 1 year (95% CI 0.40–0.40; 2640 participants) and 0.26 at 2 years or longer (95% CI 0.26–0.27; 1262 participants). Monotherapy, lower blood pressure before withdrawal and body weight were reported as predictors for successful withdrawal. Adverse events were more common in those who withdrew but were minor and included headache, joint pain, palpitations, oedema and a general feeling of being unwell. Prescribers should consider offering patients with well controlled hypertension a trial of withdrawal of antihypertensive treatment with subsequent regular blood pressure monitoring
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