4,254 research outputs found
The synthesis of MDA from helional and characterisation by isotope ratio mass spectrometry
No full textPresented here is an investigation into the stable isotopic ratios of 3,4-methylenedioxyamphetamine (MDA) prepared from the alternative precursor helional. Two methods for the synthesis of MDA were investigated, both utilising hydroxylamine as the nitrogen source. Recent publications found both helional and hydroxylamine with isotopic compositions significantly different to traditional precursors and nitrogen sources. While minimal fractionation was observed in carbon isotopic compositions, apparent fractionation occurred to hydrogen, nitrogen and oxygen isotopic compositions during the synthesis of MDA. Fractionation observed in δ15N were explained by the reaction conditions during the addition of hydroxylamine. The fractionation observed in δ18O was consistent with the replacement and loss of an oxygen atom during the synthesis of the amide intermediate and MDA. A brief investigation into isotopic fractionation during MDA hydrogen chloride (HCl) salt precipitation was also conducted, and additional fractionation may be expected in both δ2H and δ15N during the process, consistent with the proposed mechanism. These results suggest that tactical intelligence can be gained from the batch-to-batch variations to isotopic composition of MDA during the synthesis from helional.Full Tex
A survey of novel MDA and MDMA precursors by isotope ratio mass spectrometry
No full textPresented is a survey of the hydrogen, carbon and oxygen isotope profiles of traditional and novel precursors and pre-precursors used for the synthesis of 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethylamphetamine (MDMA). The purpose of this survey was to determine what variations exist in the stable isotope profiles of compounds from which these drugs can be produced. The control of the traditional precursors safrole, isosafrole, piperonal and 3,4-methylenedioxyphenyl-2-propanone (MDP2P) has seen clandestine laboratories utilising some novel alternative chemicals. Helional has emerged primarily as a precursor to MDA and although recently legislated in Queensland, Australia, remains largely uncontrolled in most jurisdictions. Results for the uncontrolled pre-precursors catechol, vanillin and vanillic acid are also presented in this survey. In total 45 precursor samples were collected, with a focus on helional that is readily available online through fragrance supply companies. The identity and purity of all samples was confirmed using a range of techniques. Stable isotope profiles were obtained by isotope ratio mass spectrometry (IRMS) analysis. These results showed a greater variation in stable isotope profiles than previously reported in MDA/MDMA precursors. These results suggest that stable isotope profiling may be used to compare and differentiate precursors used in the production of MDA/MDMA. IRMS may also allow for the grouping or discrimination of MDA and MDMA, especially when synthesised from these novel precursors or pre-precursors.Full Tex
CR1 Knops blood group alleles are not associated with severe malaria in the Gambia
No full textThe Knops blood group antigen erythrocyte polymorphisms have been associated with reduced falciparum malaria-based in vitro rosette formation (putative malaria virulence factor). Having previously identified single-nucleotide polymorphisms (SNPs) in the human complement receptor 1 (CR1/CD35) gene underlying the Knops antithetical antigens Sl1/Sl2 and McC(a)/McC(b), we have now performed genotype comparisons to test associations between these two molecular variants and severe malaria in West African children living in the Gambia. While SNPs associated with Sl:2 and McC(b+) were equally distributed among malaria-infected children with severe malaria and control children not infected with malaria parasites, high allele frequencies for Sl 2 (0.800, 1,365/1,706) and McC(b) (0.385, 658/1706) were observed. Further, when compared to the Sl 1/McC(a) allele observed in all populations, the African Sl 2/McC(b) allele appears to have evolved as a result of positive selection (modified Nei-Gojobori test Ka-Ks/s.e.=1.77, P-valu
Quantum and its irreducible representations
No full textWe define for real a unital -algebra
quantizing the universal enveloping
-algebra of . The -algebra
is realized as a -subalgebra of the
Drinfeld double of and its dual Hopf -algebra
, generated by the equatorial Podle\'s sphere coideal
-subalgebra of and
its associated orthogonal coideal -subalgebra . We then classify all the irreducible
-representations of .Comment: 22 pages; author accepted manuscrip
On the sheaf-theoretic SL(2, C) Casson–Lin invariant
No full textWe prove that the (τ-weighted, sheaf-theoretic) SL(2, C) Casson–Lin invariant introduced by Manolescu and the first author is generically independent of the parameter τ and additive under connected sums of knots in integral homology 3-spheres. This addresses two questions asked by Manolescu and the first author. Our arguments involve a mix of topology and algebraic geometry, and rely crucially on the fact that the SL(2, C) Casson–Lin invariant admits an alternative interpretation via the theory of Behrend functions.</p
Candidatus Rhetoricae (or Novus Candidatus).
No full textThis little book is a find whatever it finally turns out to be! For now it seems to be a Jesuit collegium text in rhetoric following the Progymnasmata of Aphthonius. If one works from the back of the book, there is an apparently independent 48-page work, Angelus Pacis by Nicolas Caussini (Latinized name), S.J. The rest of the book seems to be a commentary on or presentation of Aphthonius' Progymnasmata in 3 parts covering 435 pages, followed by a T of C and an AI, which is often one page off. Pars II is titled Rhetoricae Praecepta, Pars III De Panegyrico seu Laudatione. Pars I seems to be Apparatus ad Fabulam et Narrationem. Fable is handled on 15-31. After the famous Greek definition of Theion done into Latin ( sermo falsus veritatem effingens ), the author distinguishes rational (human) and moral (animal) fables, with mixed fables including both. He holds (19) that the sense of the fable generally needs to be expressed; otherwise people often miss the point of a fable. His Latin for promythium is praefabulatio, for epimythium affabulatio. Apologus and parabola are identical for him with fabula. After describing the qualities and uses of fables, the author presents some nine fables that exemplify various levels of style, twice telling the same stories on two levels (WL and FC). The last example is of the florid style: The Silkworm and the Spider takes four pages to tell! I found this book sitting in a box of disparate, unmarked, old books. It pays to look!This is a hardbound book (hard cover)Language note: Bilingual: Greek/LatinElzevers
Searches for New Physics effects in b →sl-sl+ transitions
No full textThe dissertation aims at presenting the current situation in the measurements of electroweak
penguin diagrams dominated decays: b → sl−l+1 . These decays have been a smoking gun
for hunting for New Physics effects over many years, but in the last three years the research
on these phenomena has intensified due to new measurements. Enormous progress has
been made both on the theoretical and the experimental sides to understand the measured
deviations from the current Standard Model predictions, referred to in what follows as
“anomalies”. The author of this dissertation has been one of the main authors of the angular analysis
of B0→ K∗ 0µ+µ− decay in the LHCb experiment, which has been widely regarded as one
of the most important results of the flavour physics sector in recent years. He has proposed
a method called “the method of moments” to measure the angular terms of this decay,
which he has later successfully applied in the measurement itself. Moreover, he has been
the driving force behind the two other important analyses in LHCb: the measurement of
the angular distribution and branching ratio of the B0→ K∗ 0 (1430)µ+µ− decay, where again the method of moments has been used to obtain the angular coefficients, and the search for the light scalar particle that can be produced in the b → s transitions and that decays to a dimuon pair. In this case no signal has been observed and the upper limits on the branching fraction have been set, later to be used for constraining the inflaton model.
The dissertation is organized as follows: the brief introduction is followed by, the second
chapter devoted to a theoretical description of rare B decays, where the effective field
theory formalism is introduced. Furthermore, the author discusses the current theoretical
problems in calculating the Standard Model predictions for the b → sl−l+ processes. Last but not least, the optimised angular observables that are less dependent on the form
factors uncertainness are derived. The third chapter describes the experimental apparatus
used in the b → sl−l+ measurements. Special focus is put on the sub-detectors that play
an important role in the studies of b → sl−l+ transitions. Chapters 4, 5, 6 are devoted to
describing the data analyses performed by the author in the LHCb experiment. In Chapter 7
the global analysis of electroweak penguin decays is presented. This kind of global analysis
has become extremely popular in the past few years as it helps to constrain and pin down those New Physics models that are likely to be responsible for the observed anomalies. The
author of this monograph is involved in one of the biggest collaborations performing New
Physics fits, where he is the convenor of the Flavour Working group. Furthermore, the
author presents his own study on separating the long distance effects in the B0→ K∗ 0µ+µ−decay. This is the state of the art way of determining those contributions. The chapter ends with a description of possible New Physics models that can explain the observed discrepancies
contravariant function-valued valuations on polytopes
No full textWe present a complete classification of contravariant,
-valued valuations on polytopes, without any
additional assumptions.It extends the previous results of the second author
[Int. Math. Res. Not. 2020] which have a good connection with the and
Orlicz Brunn-Minkowski theory. Additionally, our results deduce a complete
classification of contravariant symmetric-tensor-valued
valuations on polytopes
The Laurent Extension of Quantum Plane: a Complete List of Uq(sl₂)-Symmetries
No full textThis work finishes a classification of Uq(sl₂)-symmetries on the Laurent extension Cq[x±¹,y±¹] of the quantum plane. After reproducing the partial results of a previous paper of the author related to symmetries with non-trivial action of the Cartan generator(s) of Uq(sl₂) and the generic symmetries, a complete collection of non-generic symmetries is presented. Together, these collections constitute a complete list of Uq(sl₂)-symmetries on Cq[x±¹,y±¹].The author would like to thank the anonymous referees for a large number of comments and suggestions that substantially improved the initial version of this paper
Constructing Thin Subgroups in SL(4, R)
No full textWe give a construction for new families of thin subgroups inside SL(4,R). In particular, we show that the fundamental group of a closed hyperbolic 3-manifold can be isomorphic to a thin subgroup of a lattice. © The Author(s) 2013
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