scholarly journals Tobacco Cembranoids

1984 ◽  
Vol 12 (3) ◽  
Author(s):  
I. Wahlberg ◽  
C. R. Enzell
Keyword(s):  
Singlet Oxygen ◽  
Insect Resistance ◽  
The Other ◽  
Tobacco Leaf ◽  
Acid And Base ◽  
New Compounds ◽  
Insight Into ◽  
Growth Inhibiting ◽  
Considerable Insight

AbstractThe discovery of the first diterpenoids of the cembrane type in tobacco dates back to the early 1960's. Since then some forty tobacco cembranoids have been encountered. Most of these have a hydroxyl substituent at C-4 and are commonly divided into two series: those having a 4R- and those having a 4S-configuration. Additional oxygenation is found at C-6, C-7, C-8, C-11 or C-12. These compounds, which are present in the gummy exudate of the tobacco leaf and flower, are susceptible to biodegradation thus accounting for the presence of the large number of odoriferous norcembranoids in tobacco. They are also reported to include representatives having growth inhibiting and insect resistance properties. A considerable insight into the biological transformations of the tobacco cembranoids has been obtained by isolation and determination of the stereostructures of new compounds and by biomimetic experiments. The latter have involved singlet oxygen reactions, epoxidations and acid- and base-induced rearrangements. The results obtained support the importance of the (1S,2 E,4R,6R,7E,11 E)- and (1 S,2 E,4 S,6R,7 E,11 E)-2,7,11-cembratriene-4,6-diols, the major tobacco cembranoids, as key metabolites in the biogenesis of the other cembranic compounds. An account of these biogenetic reactions will be given and the isolation of a few new cembranoids will be reported.

A Uniform Method for Determining Angular Accelerations in Mechanisms

1946 ◽  
Vol 13 (1) ◽  
pp. A41-A44
Author(s):  
L. R. Koenig
Keyword(s):  
Full Advantage ◽  
Velocity Vector ◽  
Angular Acceleration ◽  
Uniform Method ◽  
Insight Into ◽  
Considerable Insight

Abstract The purpose of this paper is to disclose a more reliable and uniform method, applicable to mechanisms in general, for determining directly the angular accelerations of the constituent links. The method completely suffices where the determination of angular accelerations is the end in view. Although it is independent of normal, tangential, and total accelerations of points on the links, reliable determinations of such accelerations are considerably facilitated with the aid of the acquired angular accelerations. Angular-acceleration problems may be solved with increased assurance because; (a) only velocity-vector considerations are required in the necessary kinematic layouts; (b) full advantage may be taken of the process of inversion in simplifying velocity-vector layouts, which is not possible when acceleration vectors are employed; and (c) the method gives considerable insight into the effects of the various factors controlling the angular accelerations.

Accuracy of the final model

2002 ◽  
Author(s):  
David Blow
Keyword(s):  
Data Bank ◽  
The Other ◽  
Protein Crystal ◽  
Major Error ◽  
Final Model ◽  
Bond Angles ◽  
Bond Lengths ◽  
R Factor ◽  
Insight Into

The result of all the work described in the previous chapters will be a set of coordinates and other data suitable for deposit in the Protein Data Bank. You or I may use these coordinates, and we need to have some insight into their accuracy and reliability. In the previous chapters, indicators have been described, which may suggest aspects of the data or interpretation procedures that might lead to problems. But as the determination of protein crystal structures becomes more routine, many of these indicators are omitted from publications. Fortunately, crystallographic procedures are self-checking to a large extent. It is rare for a major error of interpretation to lead right through to a published refined structure. A high Rfree factor is a warning, especially if coupled with departures from the requirements of correct bond lengths, angles, and acceptable dihedral angles. On the other hand, there will always be a desire to squeeze more results from the data. All interpretations are subject to error; nearly all protein crystals have regions that are less ordered, where accurate interpretation is less feasible; and the structure may be overrefined, using too many variables for the data. If the majority of the molecule is correctly interpreted, a reasonable R factor may be obtained even though some small regions are completely wrong. During refinement it is usual to restrain the bond lengths and bond angles to be near their theoretical values, as described in Chapter 12. The extent to which bond lengths and bond angles depart from these values is often quoted as an indicator of accuracy. These departures are, however, difficult to interpret because they depend on how tightly the restraints have been applied. The same applies to the restraint of certain coordinates to lie in a plane. This difficulty illustrates a general problem. Designers of refinement procedures are understandably anxious to improve their procedures to lead directly to a well-refined structure. Every aspect of structure that can be recognized as having a regularity could, in principle, be expressed as a restraint which enforces it during refinement.

Remembrances

Tallis ◽  
2020 ◽  
pp. 197-208
Author(s):  
Kerry McCarthy
Keyword(s):  
Family Background ◽  
The Other ◽  
The Everyday ◽  
The Will ◽  
Insight Into ◽  
Considerable Insight

This final chapter returns to the details of Tallis’s biography. It examines his will and the will of his wife Joan, two documents which offer considerable insight into his social circles and the everyday material surroundings of his household, as well as what little we can deduce of his family background. The chapter also discusses Tallis’s epitaph (very recently rediscovered by the author in a more accurate version) and the other memorial poems written at his death in 1585, including Ye sacred Muses, set to music by Byrd. It concludes with some reflections on Tallis’s enigmatic life and his musical gifts.

Bioindicators and Biomarkers

2013 ◽  
Vol 1 (2) ◽  
Author(s):  
Alejandra Hernández-Ceruelos ◽  
Patricia Vázquez-Alvarado ◽  
Nadia Pelallo-Martínez ◽  
Sergio Muñoz-Juárez
Keyword(s):  
Clinical Trials ◽  
Secondary Metabolites ◽  
Epidemiological Studies ◽  
The Other ◽  
Laboratory Practice ◽  
Research And Practice ◽  
Good Laboratory ◽  
Sensitivity Specificity ◽  
Insight Into

The health of an ecosystem can be examined through the use of bioindicators (BI), while the health of a human being can be determined using some molecules such as biomarkers (BM). BI are complete organisms or part of them that can be measured to detect changes in the environment, the presence of pollution and its effect on the ecosystem, as well as the observation of the progress of environmental clean-up. On the other hand, specific kinds of BI are the BM, which are biomolecules, secondary metabolites or measurable parameters used in medical research and practice to provide an insight into the mechanics and course of a disease. In general BM are classified into three groups: exposure, effects or susceptibility, and their role depends on the sensitivity, specificity, reliability and reproducibility of the methods used in the determination of the target molecule selected to be an specific BM, and it has to be validated under the development of guidelines, supported with good laboratory practice, epidemiological studies and clinical trials. BM can be used to detect subclinical stages, to become a diagnostic tool, to observe the efficacy of the treatment or monitoring the different stages on the development of the pathology.

Much Ado about Handwriting: Countersigning with the Other Hand in Stevenson’s The Strange Case of Dr. Jekyll and Mr. Hyde

2006 ◽  
Author(s):  
Jodey Castricano
Keyword(s):  
Structural Model ◽  
The Other ◽  
Multiple Personality Disorder ◽  
The Novel ◽  
Borderline Personality Disorders ◽  
Double Binds ◽  
Other Hand ◽  
Insight Into

Abstract Robert Louis Stevenson’s The Strange Case of Dr. Jekyll and Mr. Hyde has been seen as the nineteenth century prototype of the workings of the criminal mind. Similarly, current psychoanalytic readings of the novel suggest that it serves as a precursor to Freud’s theories on the structural model of personality, and repression and that Dr. Jekyll and Mr. Hyde can provide insight into the psychology of addiction, multiple personality disorder and borderline personality disorders, as these terms have currency in the discipline of modern psychology. Indeed, Stevenson’s novel can even be seen as a precursor to the very genre of Freud’s “case” study. In fact, current readings of Dr. Jekyll and Mr. Hyde continue to focus on its case study aspects, claiming that the novel shows “the composition and operation of the criminal mind” (Thomas qtd in Rosner, Spring 29). “Much Ado About Handwriting: Countersigning with the Other Hand in The Strange Case of Dr. Jekyll and Mr. Hyde is concerned with making a Gothic case “the composition and operation of the criminal mind,” but not because the word “composition” denotes a mental constitution that merely pre-exists the text or that the text refers to or represents a substantive criminal mind; instead the word suggests that there exists a displaced link between writing, reading, interpretation, and criminality as the shadowy “place” where the “other” begins and collusion enters the scene. Taking as a premise Jacques Derrida’s contention that “it is the ear of the other that signs,” this paper is concerned with “composition,” signatures and encryption as a way of exploring how these texts pose insoluble psychic double binds regarding the determination of criminality.

Deep-cavity subporphyrazines with extended π-perimeters

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1277-1283 ◽  
Author(s):  
Roman Münnich ◽  
Patricia Löser ◽  
Andreas Winzenburg ◽  
Rüdiger Faust
Keyword(s):  
Cyclic Voltammetry ◽  
Singlet Oxygen ◽  
The Other ◽  
Quantum Yields ◽  
Spectroscopic Techniques ◽  
Fluorine Substitution ◽  
Deep Cavity ◽  
Other Hand ◽  
Specific Induction

Unprecedentedly large subporphyrazines (SubPz) with dibenzoquinoxalino-fusion and peripheral phenyl substitution were prepared by the cyclization of perfluorated or non-fluorous polyphenyl-substituted quinoxaline dinitriles and characterized by spectroscopic techniques. The compounds suitability to act as photosensitizers was explored by wavelength-specific induction of singlet oxygen luminescence and was shown to be excellent. Determination of 1O2-quantum yields suggests that fluorine substitution enhances the photosensitization efficiencies of the SubPz. On the other hand, cyclic voltammetry reveals an increase of irreversible reductive processes in case of the fluorinated SubPz.

Methylzinn- und Methylindium-bis(trimethylsilyl)amide / Methyltin and Methylindium Bis(trimethylsilyl)amides

1991 ◽  
Vol 46 (4) ◽  
pp. 459-467 ◽  
Author(s):  
Michael Rannenberg ◽  
Johann Weidlein ◽  
Axel Obermeyer
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Homologous Series ◽  
Nmr Spectra ◽  
The Other ◽  
Crystal Structure Determination ◽  
New Compounds

BrSn[N(SiMe3)2]3 and ClIn[N(SiMe3)2]2 react with LiMe · O(C2H5)2 (Me = CH3) in toluene or hexane to give the corresponding amido derivatives MeM[N(SiMe3)2]x (M = Sn, x = 3 and M = In, x = 2). These new compounds and the other members of the homologous series MenM[N(SiMe3)2]4 or 3-n are characterized by their IR, Raman und NMR spectra. In addition, the results of the crystal structure determination of MeSn[N(SiMe3)2]3 are reported.

Determination of the lattice translation across {110} APBs in GaAs

1988 ◽  
Vol 46 ◽  
pp. 600-601
Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter
Keyword(s):  
Grain Boundaries ◽  
Lower Energy ◽  
Antiphase Boundary ◽  
The Other ◽  
Boundary Structure ◽  
Interface Plane ◽  
Inversion Symmetry ◽  
High Angle ◽  
Equilibrium Distance

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.

Determination of the Burgers vector of a dislocation in a Fe-Mn alloy by weak-beam image in HVEM

1978 ◽  
Vol 36 (1) ◽  
pp. 330-331
Author(s):  
Y. Ishida ◽  
H. Ishida ◽  
K. Kohra ◽  
H. Ichinose
Keyword(s):  
High Order ◽  
Simulation Technique ◽  
The Other ◽  
Image Simulation ◽  
Diffraction Vector ◽  
Burgers Vector ◽  
Weak Beam ◽  
Beam Image ◽  
Edge Component

IntroductionA simple and accurate technique to determine the Burgers vector of a dislocation has become feasible with the advent of HVEM. The conventional image vanishing technique(1) using Bragg conditions with the diffraction vector perpendicular to the Burgers vector suffers from various drawbacks; The dislocation image appears even when the g.b = 0 criterion is satisfied, if the edge component of the dislocation is large. On the other hand, the image disappears for certain high order diffractions even when g.b ≠ 0. Furthermore, the determination of the magnitude of the Burgers vector is not easy with the criterion. Recent image simulation technique is free from the ambiguities but require too many parameters for the computation. The weak-beam “fringe counting” technique investigated in the present study is immune from the problems. Even the magnitude of the Burgers vector is determined from the number of the terminating thickness fringes at the exit of the dislocation in wedge shaped foil surfaces.

A Bird in the Hand Isn’t Good for Long

2018 ◽  
Vol 65 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Stefan Scherbaum ◽  
Simon Frisch ◽  
Maja Dshemuchadse
Keyword(s):  
Decision Making ◽  
Cognitive Control ◽  
The Other ◽  
Decision Task ◽  
Short Term ◽  
Additional Time ◽  
Control Processes ◽  
Folk Wisdom ◽  
Study Participants ◽  
Insight Into

Abstract. Folk wisdom tells us that additional time to make a decision helps us to refrain from the first impulse to take the bird in the hand. However, the question why the time to decide plays an important role is still unanswered. Here we distinguish two explanations, one based on a bias in value accumulation that has to be overcome with time, the other based on cognitive control processes that need time to set in. In an intertemporal decision task, we use mouse tracking to study participants’ responses to options’ values and delays which were presented sequentially. We find that the information about options’ delays does indeed lead to an immediate bias that is controlled afterwards, matching the prediction of control processes needed to counter initial impulses. Hence, by using a dynamic measure, we provide insight into the processes underlying short-term oriented choices in intertemporal decision making.

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