Unexpected By-product Research Articles

Another look at volume self-calibration: calibration and self-calibration within a pinhole model of Scheimpflug cameras

We address calibration and self-calibration of tomographic PIV experiments within a pinhole model of cameras. A complete and explicit pinhole model of a camera equipped with a 2-tilt angles Scheimpflug adapter is presented. It is then used in a calibration procedure based on a freely moving calibration plate. While the resulting calibrations are accurate enough for Tomo-PIV, we confirm, through a simple experiment, that they are not stable in time, and illustrate how the pinhole framework can be used to provide a quantitative evaluation of geometrical drifts in the setup. We propose an original self-calibration method based on global optimization of the extrinsic parameters of the pinhole model. These methods are successfully applied to the tomographic PIV of an air jet experiment. An unexpected by-product of our work is to show that volume self-calibration induces a change in the world frame coordinates. Provided the calibration drift is small, as generally observed in PIV, the bias on the estimated velocity field is negligible but the absolute location cannot be accurately recovered using standard calibration data.

A Machine Intelligence Designed Bayesian Network Applied to Alzheimer's Detection Using Demographics and Speech Data

Bayesian networks (BNs) have classically been designed by two methods: expert approach (ask an expert for nodes and links) and data driven approach (infer them from data). An unexpected by-product of previous Alzheimer's / dementia research (presented at CAS2015) was yet another approach where the results of a hybrid design were used to configure a BN. A complex adaptive systems approach, (e.g. GA-SVM-oracle hybrid) can sift through the combinatorics of feature subset selection, yielding a modest set of only the most influential features. Then using known likelihoods of demographics associated to dementia, and assuming direct and independent influence of dementia upon speech features, the BN is specified. The conditional probabilities needed can be estimated with far fewer data than the traditional BN data-driven approach. Although BNs have advantages (intuitive interpretation and graceful handling of missing data) they also have challenges. We report initial implementation results that suggest the need to reduce continuous variables to discrete categories, and the still-remaining need to estimate a substantial number of conditional probabilities, remain challenges for BNs. We suggest some ways forward in the application of BNs with the objective of improving / refining Alzheimer's / dementia detection using speech.

Crystallographic identification of an unexpected by-product in an Ullman's reaction toward biphenyls: 1-(4-hexyloxy-3-hydroxyphenyl)ethanone.

The synthesis of 3,3'-diacetoxy-4,4'-bis(hexyloxy)biphenyl following the nickel-modified Ullmann reaction yielded a by-product which was identified successfully by crystallographic analysis as 1-(4-hexyloxy-3-hydroxyphenyl)ethanone, C14H20O3. This unexpected nonbiphenyl by-product exhibited IR, (1)H NMR, (13)C NMR and COSY (correlation spectroscopy) spectra fully consistent with the proposed structure. The compound crystallized in the orthorombic Pbca space group, with two independent formula units in the asymmetric unit (one of which was slightly disordered), and showed a supramolecular architecture in which molecules linked by hydroxy-ethanone O-H···O interactions are organized in columns separated by the aliphatic tails.

Delay-induced Turing-like waves for one-species reaction-diffusion model on a network

A one-species time-delay reaction-diffusion system defined on a complex network is studied. Traveling waves are predicted to occur following a symmetry-breaking instability of a homogeneous stationary stable solution, subject to an external nonhomogeneous perturbation. These are generalized Turing-like waves that materialize in a single-species populations dynamics model, as the unexpected byproduct of the imposed delay in the diffusion part. Sufficient conditions for the onset of the instability are mathematically provided by performing a linear stability analysis adapted to time-delayed differential equations. The method here developed exploits the properties of the Lambert W-function. The prediction of the theory are confirmed by direct numerical simulation carried out for a modified version of the classical Fisher model, defined on a Watts-Strogatz network and with the inclusion of the delay.

Crystal Structure of 3,3′-Ethanediylidenebis(1-ethylindoline-2-one): An Unexpected Byproduct in <i>N</i>-Ethylation of Isatin in Tetrahydrofurane

Crystal Structure of 3,3′-Ethanediylidenebis(1-ethylindoline-2-one): An Unexpected Byproduct in <i>N</i>-Ethylation of Isatin in Tetrahydrofurane

Reactivity of TpMe2-Containing Hydride–Iridafurans with Alkenes, Alkynes, and H2

The TpMe2-containing hydride-iridafurans 2a,b (TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate) cleanly reacted with ethylene to give the bicyclic derivatives 6a,b. Formation of the latter complexes is a reversible process, and it is proposed to occur by an electrocyclic ring closure that takes place between C2H4 and the 16e unsaturated intermediates A, resulting from hydride migration to the α carbon of the metallacycle. Similar reactions were observed with a variety of alkynes RC≡CR (R = H, Ph, CO2Me) and R′C≡CH (R′= CO2Me, Ph, CMe3), with the regioselectivity observed for the latter substrates depending on the nature of R′. In the case of Me3SiC≡CH the structure of an unexpected byproduct indicates that an alkyne–vinylidene rearrangement has taken place on the metal coordination sphere during the reaction, and this observation suggests that in the mechanism of all these coupling processes the corresponding π adducts are active intermediates. Finally, complexes 2a,b reacted with H2 to give products derived from the hydrogenation of their alkenyl arms.

Revised role of selectfluor in homogeneous Au-catalyzed oxidative C-O bond formations.

The pairing of transition metal catalysis with the reagent Selectfluor (F-TEDA-BF4) has attracted considerable attention due to its utility in myriad C-C and C-heteroatom bond-forming reactions. However, little mechanistic information is available for Selectfluor-mediated transition metal-catalyzed reactions and controversy surrounds the precise role of Selectfluor in these processes. We present herein a systematic investigation of homogeneous Au-catalyzed oxidative C-O bond-forming reactions using density functional theory calculations. Currently, Selectfluor is thought to serve as an external oxidant in Au(I)/Au(III) catalysis. However, our investigations suggest that these reactions follow a newly proposed mechanism in which Selectfluor functions as an electrophilic fluorinating reagent involved in a fluorination/defluorination cycle. We have also explored Selectfluor-mediated gold-catalyzed homocoupling reactions, which, when cyclopropyl propargylbenzoate is used as a substrate, lead to an unexpected byproduct.

Synthesis and Crystal Structures of New 1,4-Disubstituted 1,2,4-Triazoline-5-thiones

Abstract Introduction of sulfur into the 5-position of 1,4-disubstituted quaternary 1,2,4-triazolium salts (1-9; Cl, Br, I, BF4, PF6, CH3OSO3 were used as anions) by two methods was investigated. The syntheses of nine 1,4-disubstituted 1,2,4-triazoline-5-thiones 10-18 are reported (1, 10: R1 = CH3, R2 = CH3; 2, 11: R1 = NH2, R2 = CH3; 3, 12: R1 = NH2, R2 = CH(CH3)2; 4, 13: R1 = N(CH3)2, R2 = CH3; 5, 14: R1 = N(CH3)2, R2 = CH(CH3)2; 6, 15: R1 = CH3, R2 = NH2; 7, 16: R1 = OCH2Ph, R2 = CH3; 8, 17: R1 = OCH2Ph, R2 = CH2CH3; 9, 18: R1 = CH3, R2 = CH2Ph). Compounds 11-17 represent 1-amino, 4-amino, 4-dimethylamino, and 4-benzyloxy-1,2,4-triazoline-5- thiones, whereas 10 served as a reference compound. Thione 18 was identified as an unexpected by-product in the synthesis of 16 and was also prepared independently. Thermolysis of 10 in air gave 1,4-dimethyl-1,2,4-triazolium hydrogensulfate. Crystal structures of eight 1,4-disubstituted 1,2,4- triazoline-5-thiones were determined by single-crystal X-ray diffraction. Intermolecular hydrogen bonds (C-H···S, C-H···N, N-H···N, N-H···S) were observed in the solid state. The solvent-dependent 1H NMR chemical shifts of signals of 10 and 13 were satisfactorily correlated with the Kamlet- Abboud-Taft π* and b parameters in ten solvents. From the lack of correlation with the a parameter and from the C=S bond length (average 1.67 Å) a significant contribution of a mesoionic imidazolium-2-thiolate resonance structure seems unlikely

ADESubalgebras of the Triplet Vertex Algebra 𝒲(p):E6,E7

It is the forth paper in a series devoted to the investigation of the |$ADE$| subalgebras of the triplet vertex algebra |$\mathcal {W}(p)$|⁠. In this paper, we prove |$C_{2}$|-cofiniteness of the invariant subalgebras |$\mathcal {W}(p)^{\Gamma }$| and study their representations when |$\Gamma$| is the tetrahedral group |$T$| (of |$E_6$|-type), or the octahedral group |$O$| (of |$E_7$|-type). We give a list of |$21p$| irreducible |$\mathcal {W}(p)^{T}$|-modules and a list of |$28p$| irreducible |$\mathcal {W}(p)^{O}$|-modules. The completeness of these two lists can be reduced to some conjectures about constant term identities which have been verified in the case |$p=1$|⁠. For the proof of |$C_{2}$|-cofiniteness of |$\mathcal {W}(p)^{\Gamma }$|⁠, and the calculations of the Zhu's algebras |$A(\mathcal {W}(p)^{\Gamma })$|⁠, we develop several quite universal formulas (Theorem 4.3 and its corollaries). In Appendix, we further apply them to derive a useful tool of structure coefficients for the triplet vertex algebra |$\mathcal {W}(p)$| and its irreducible modules, which unifies almost all the calculations in this paper; as an unexpected byproduct, we give a new proof of |$\mathfrak {sl}_{2}$|-action on |$\mathcal {W}(p)$|⁠.

Transformation of syngas to light hydrocarbons over bifunctional CuO–ZnO/SAPO-34 catalysts: the effect of preparation methods

Two series of bifunctional catalysts CuO–ZnO/SAPO-34 were prepared by isometric impregnation and milling calcination. The catalyst samples with different composition ratios have been investigated in the direct transformation of syngas to light hydrocarbons. Furthermore, all the samples were characterized by SEM, XRD, BET, H2-TPR and NH3-TPD techniques. The catalytic reactions were conducted with a feeding gas mixture of CO and H2 at 320 °C and 3.0 MPa. The results indicate that the preparation methods have significant effect on the catalysts performance. Though both series of catalysts could realize the direct transformation and the catalysts prepared by the milling calcination method facilitated a little more syngas to convert, the catalysts prepared by the impregnation method led to higher light hydrocarbons selectivity and less unexpected byproduct like CO2, since these serious catalysts displayed a smaller amount of metallic solid solution, a stronger interaction between the loaded metallic particles and supportive zeolites, more appropriate acidity strength as well.

A novel carotenoid, 4-keto-α-carotene, as an unexpected by-product during genetic engineering of carotenogenesis in rice callus

Rice endosperm is devoid of carotenoids because the initial biosynthetic steps are absent. The early carotenogenesis reactions were constituted through co-transformation of endosperm-derived rice callus with phytoene synthase and phytoene desaturase transgenes. Subsequent steps in the pathway such as cyclization and hydroxylation reactions were catalyzed by endogenous rice enzymes in the endosperm. The carotenoid pathway was extended further by including a bacterial ketolase gene able to form astaxanthin, a high value carotenoid which is not a typical plant carotenoid. In addition to astaxanthin and precursors, a carotenoid accumulated in the transgenic callus which did not fit into the pathway to astaxanthin. This was subsequently identified as 4-keto-α-carotene by HPLC co-chromatography, chemical modification, mass spectrometry and the reconstruction of its biosynthesis pathway in Escherichia coli. We postulate that this keto carotenoid is formed from α-carotene which accumulates by combined reactions of the heterologous gene products and endogenous rice endosperm cyclization reactions.

Role of the σRs for Development of Medications.

Role of the σRs for Development of Medications.

Construction of the A ring of halichomycin via a RCM strategy

Attempts to the synthesis of the A ring of halichomycin via ring-closing metathesis (RCM) reaction were investigated. When triene 5 was used as the precursor of cyclization, only unexpected byproduct aldehyde 17 was obtained. When diene 6 was used as the precursor of cyclization, the desired product 20 was obtained in reasonable yield. This work demonstrated that both modification of the substrate and the RCM reaction conditions are important for obtaining the desired 11-membered macrocycle in reasonable yield.

Low-energy tools underlie high-energy physics

Charles Roos (Physics Today, May 2012, page 10) has charged me with naiveté in claiming that high-energy particle physics has never produced jobs for anyone but HEP physicists (Physics Today, September 2011, page 10). In support of his charge he cites several developments stemming from HEP research that have contributed significantly to the economy and to job growth.However, Roos appears to have inadvertently made my case for me: None of the contributions he cites has anything to do with HEP physics itself. All are tools engineered from lower-energy electron-volt physics, or byproduct results, or spinoffs. High-field and superconducting magnets are pure eV physics. Money spent on the thousands of them in the Large Hadron Collider at CERN would have benefited the country and the world more if the funds had instead been spent on developing superconducting transmission lines to convey electricity efficiently from the remote solar and wind farms generating it to urban centers using it.All R&D programs generate unexpected byproduct results or spinoffs. That is an excellent reason for public support of science: You always get lagniappe—more than you paid for. However, the unpredictability of those results means that the expectation of them cannot be the basis for choosing to support one program over another. For example, the development of integrated-circuit microprocessors was greatly speeded by NASA’s need for extremely lightweight computers in triplicate for its space capsules. So the entire computer industry—for smartphones, cars, washing machines, and refrigerators—can be claimed to be a byproduct of the space program. Millions of jobs! (Memo to NASA: Ask for more money.)All the jobs for which Roos credits HEP physics are applications of eV physics and result merely from the expenditure of vast sums of money, irrespective of the goal for which it was spent. They have nothing to do with HEP physics itself.© 2012 American Institute of Physics.

Infinite dimensional manifolds from a new point of view

In this paper we propose a new treatment about infinite dimensional manifolds, using the language of categories and functors. Our definition of infinite dimensional manifolds is a natural generalization of finite dimensional manifolds in the sense that de Rham cohomology and singular cohomology can be naturally defined and the basic properties (Functorial Property, Homotopy Invariant, Mayer–Vietoris Sequence) are preserved. In this setting we define the classifying space BG of a Lie group G as an infinite dimensional manifold. Using simplicial homotopy theory and the Chern–Weil theory for principal G-bundles we show that de Rhamʼs theorem holds for BG when G is compact. Finally we get, as an unexpected byproduct, two simplicial set models for the classifying spaces of compact Lie groups; they are totally different from the classical models constructed by Milnor, Milgram, Segal and Steenrod.

Novel approach for optimization of a ‘difficult’ peptide synthesis by utilizing quantitative reaction monitoring assays

Three different synthetic strategies were tested to synthesize EGFRvIII peptide (1), which is a functional variant of the epidermal growth factor receptor, a protein that has been well validated as a target for cancer therapy. The initial synthesis was performed with Applied Biosystem (Carlsbad, CA, USA) 433A peptide synthesizer and it indicated that the last three amino acids coupling and Fmoc removal rates were lower than the rest of the sequence. Purity of the crude peptide was 54.5%. The second synthesis was performed manually utilizing C S Bio (Menlo Park, CA, USA) synthesizer and the Kaiser test for reaction monitoring. Because of non-optimized reaction conditions and an unexpected by-product, lower purity crude peptide (40.5%) was obtained. Quantitative assays to monitor reactions were developed and demonstrated in gram scale synthesis with C S Bio synthesizer. The optimized synthetic conditions improved the peptide purity to 68.1%.

On-column ligand exchange for structure-based drug design: a case study with human 11β-hydroxysteroid dehydrogenase type 1.

Successfully forming ligand-protein complexes with specific compounds can beasignificant challenge in supporting structure-based drug design for a given protein target. In this respect, an on-column ligand- and detergent-exchange method was developed to obtain ligand-protein complexes of an adamantane series of compounds with 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) after a variety of other complexation methods had failed. This report describes the on-column exchange method and an unexpected byproduct of the method in which artificial trimers were observed in the structures.

History on the margin: unravelling the changing fortunes of a Devon house and its relation to the locality

It has long been recognised that the line between the noted and the ignored in architectural history is somewhat arbitrary, and that despite Pevsner's confident assertion about the cathedral and the bicycle shed in his Outline of European Architecture, no summary division between architecture and mere building can be achieved. Furthermore, the general rule that nothing under thirty years gets listed while everything over 300 years does reflects at one end uncertainty in judging the recent, and at the other the rarity of survival. This study lies in between, presenting a case that has recently crossed the boundary of recognition through listing as an historic monument. The story began with personal curiosity about a second-rate Devon house connected with the author's family, but opened up into a much wider story about the changing history of place, and advances in technology embracing water power, the printed book and the coming of the railway. An unexpected by-product was the exemplary impact of aristocratic power felt through the uncompleted follies of the last Earl of Egremont and the architect whose career he launched, J.T.Knowles. The intention is neither to identify an overlooked masterpiece, nor to extend the canon, but to show the manner in which the history of ordinary buildings can, with the advantage of hindsight, be richly definitive of time, place and changes in society.

Is there room for dual blockade of the renin–angiotensin–aldosterone system?

Is there room for dual blockade of the renin–angiotensin–aldosterone system?

Synthesis and Structure of (Bis(1-propylbenzimidazol-2-yl)-trans-1,2-cyclohexane)copper(II) Dichloride and the Structure of a Novel, Unexpected By-Product

Two structures containing the novel ligand bis(1-propylbenzimidazol-2-yl)-trans-1,2-cyclohexane, L, are reported. The first structure, (bis(1-propylbenzimidazol-2-yl)-trans-1,2-cyclohexane)copper(II) dichloride, Cu(II)(L)Cl2 1, crystallized in the monoclinic space group P 21/n with a = 10.992(4) A, b = 13.576(5) A, c = 18.047(7) A, β = 106.909(8) and V = 2576.7(16) A3 and Z = 4. Complex 1 exhibits a D 2d-flattened tetrahedral Cu(II)N2Cl2 coordination geometry, for which the four-coordinate geometry index τ4 of 0.59 lies almost midway between the ideal geometry values of zero (square-planar) and 1 (tetrahedral). The second and unexpected structure, (bis(1-hydro-3-propylbenzimidazol-1-ium)-trans-1,2-cyclohexane)(μ4-oxo-hexa-(μ2-chloro)-tetra(chloro-copper(II)) di(nitromethane) solvate, 2[H2L]2+[Cu4OCl10]4−·(CH3NO2)2, 2, consists of three dimensionally hydrogen bonded bis(benzimidazolium) dications and tetra-copper(II)-oxo-chloride tetra-anions, interspersed with nitromethane solvate molecules. A balanced equation for the formation of the byproduct suggests that it forms via an acid–base reaction in the presence of water in the reaction mixture. The complex crystallized in the triclinic space group P −1 with a = 13.696(3) A, b = 13.819(3) A, c = 16.797(4) A, α = 89.480(4), β = 87.308(4)°, γ = 89.434(4) and V = 3175.3(12) A3 and Z = 2. Ligand L contains two stereogenic centers, each of the same handedness, and, since the space groups determined for structures 1 and 2 are centrosymmetric, both structures are racemates. Both title complexes contain the ligand bis(1-propylbenzimidazol-2-yl)-trans-1,2-cyclohexane. The first structure corresponds to the target complex with D 2d-flattened tetrahedral Cu(II)N2Cl2 coordination. For this structure, the four-coordinate geometry index τ4 of 0.59 lies almost midway between the ideal geometry values of zero (square-planar) and 1 (tetrahedral). The second and unexpected structure is a minor by-product which contains two hydrogen bonded diprotonated ligand dictations and a copper-oxo tetra-anion interspersed with nitromethane. A balanced equation for the formation of the byproduct suggests that it forms via an acid–base reaction in the presence of water in the reaction mixture.