866 research outputs found
T.H. Green on property rights
No full textbook chapterPublished.Darin R. Nesbitt (Douglas College Faculty) contributed the chapter, "T.H. Green on property rights" (1st ed. 2005)
T.H. Huxley: The Agnostic
No full textThe author offers a biographical sketch of T.H. Huxley, known as Darwin\u27s Bulldog, his stance on evolution and religion, including an exposition of agnostic philosophy
Soft X-ray properties of a spectroscopically selected sample of interacting and isolated Seyfert galaxies
No full textWe present a catalogue of ROSAT detected sources in the sample of spectroscopically selected Seyfert 1 and Seyfert 2 galaxies of Rafanelli et al. (\cite{Rafanelli95}). The catalogue contains 102 Seyfert 1 and 36 Seyfert 2 galaxies. The identification is based on X-ray contour maps overlaid on optical images taken from the Digitized Sky Survey. We have derived the basic spectral and timing properties of the X-ray detected Seyfert galaxies. For Seyfert 1 galaxies a strong correlation between photon index and X-ray luminosity is detected. We confirm the presence of generally steeper X-ray continua in narrow-line Seyfert 1 galaxies (NLS1s) compared to broad-line Seyfert 1 galaxies. Seyfert 2 galaxies show photon indices similar to those of NLS1s. Whereas a tendency for an increasing X-ray luminosity with increasing interaction strength is found for Seyfert 1 galaxies, such a correlation is not found for Seyfert 2 galaxies. For Seyfert 1 galaxies we found also a strong correlation for increasing far-infrared luminosity with increasing interaction strength. Both NLS1s and Seyfert 2 galaxies show the highest values of far-infrared luminosity compared to Seyfert 1 galaxies, suggesting that NLS1s and Seyfert 2 galaxies host strong (circumnuclear) star formation. For variable Seyfert galaxies we present the X-ray light curves obtained from the ROSAT All-Sky Survey and from ROSAT PSPC and HRI pointed observations. Besides the expected strong short- and long-term X-ray variability in Seyfert 1 galaxies, we find indications for X-ray flux variations in Seyfert 2 galaxies. All overlays can be retrieved via CDS anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)} or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/368/79
Een ontwerp van een boeken-oproepsysteem (bibliofoon) voor de Centrale Bibliotheek van de T.H. Delft
No full textHet ontwerpen en bouwen van een boeken-oproepsysteem (bibliofoon) voor de bibliotheek van de T.H. Delft. Deze bibliofoon moet on-line door een computer bediend kunnen worden. Het uitgangspunt dient te zijn, dat de besturing zoveel mogelijk door deze computer gedaan wordt. In verband met de betrouwbaarheid moet overwogen worden om uitsluitend I.C.'s en Reed-relais toe te passen.Electrical Engineering, Mathematics and Computer ScienceLaboratorium voor Automatische Verkeerssysteme
Structure-function analysis of plant fructosyltransferases
No full textFructans are an important class of plant carbohydrates that consist of linear or
branched chains of fructosyl moieties. Their synthesis requires fructosyltransferases
(FTs) that catalyze the transfer of fructosyl units from a donor substrate (sucrose or
fructan) to an acceptor substrate (sucrose or fructan). The fructosyltransferases involved
in fructan metabolism are related to acid invertases, enzymes that cleave sucrose into
glucose and fructose. An invertase can be considered a fructosyltransferase which
transfers the fructose moiety to water. The aim of the present work was to elucidate what
determines the different catalytic activities of this enzyme group, by use of molecular
methods. In order to study such structure-function relationships we artificially introduced
mutational changes and constructed chimeric FTs (enzymes with exchanged regions).
The goal was to detect the determining regions or single amino acids. For this purpose we
optimized the expression of FTs in the methylotrophic yeast Pichia pastoris and
developed the methodology to create the chimeric constructs. Conventional cloning using
conveniently located restriction sites and the method of overlapping PCR was used.
In a first part domain exchanges between two closely related FTs from cereals
were analyzed by expressing the corresponding constructs in Pichia (Chapter 2). The two
subunits of FTs (N-terminal large subunit and C-terminal small subunit) were exchanged
between Festuca arundinacea (re-classified as Schedonorus arundinaceus)
sucrose:sucrose 1-fructosyltransferases (1-SST) and Hordeum vulgare sucrose:sucrose 6-
fructosyltransferase (6-SFT). The study revealed that it is the large subunit that carries the
structural features responsible for enzyme specificity.
In a second part we focused on the conserved motifs (S/N)DPNG, RDP and EC,
located on the large subunit, that are presumably essential in the active site of plant FTs.
For this purpose two other SST-SFT-chimeras with exchanged N-termini encompassing
these motifs, as well as Festuca 1-SST carrying single amino acid substitutions in the
RDP- and EC-motif were analyzed (Chapter 3). This study revealed the importance of the
three hypothesized active site motifs for the transfructosylation reaction. All three of
them were shown to be important for enzyme activity and/or for specificity.
In a third part, we addressed the question what structural components determine
the relative transferase and hydrolase activities of FTs and vacuolar invertases via a
targeted mutational analysis based on sequence comparisons between vacuolar invertases
and 1-SSTs, the latter an example of a sucrose-using FT (Chapter 4). We chose Allium
cepa invertase and Festuca arundinacea 1-SST for our analysis. Nine amino acids
dispersed along the sequence could be identified correlating with either invertase or
1-SST activities. The selected amino acids of onion invertase were mutated to the
corresponding amino acids in Festuca 1-SST and vice versa. For both enzymes, the
mutations were analyzed independently. Functional expression in Pichia revealed shifts
in the catalytic specificity and activity, demonstrating the importance of these amino
acids outside the three highly conserved motifs (S/N)DPNG, RDP, and EC for the
enzymatic reaction (Chapter 4).
This work helped to narrow down the region potentially responsible for enzyme
specificity in plant FTs. We could pinpoint the importance of the regions with the highly
conserved motifs, and of some additional characteristic single amino acids dispersed
along the sequence, for enzyme activity and specificity
Letter from T.H. Hayes, Jr. to Attorney Henry M. Beaty Jr
No full textA letter of recommendation for Russell B. Sugarmon, Jr. to be admitted to the bar in Memphis and Shelby County. The author commends his ability, character, and family background
Vibration Based Damage Identification in a Composite T-Beam Utilising Low Cost Integrated Actuators and Sensors
No full textThe development of integrated measurement systems for composite structures is urged by the fact that a Structural Health Monitoring environment requires these systems to become an integral part of the structure. The feasibility of using low cost piezoelectric diaphragms for dynamic characterisation and vibration based damage identification in a composite T-beam structure is demonstrated. The dynamic behaviour is analysed by applying these basic electronic sound components for actuation and sensing. Impact induced damage at the skin-stiffener connection is detected and localized by applying the MSE-DI algorithm on the measured bending strain mode shapes
Map of the emigrant road from Independence Mo. to St. Francisco, California /
No full textRelief shown by hachures.Accompanied by text: Accompaniment to the Map of the emigrant road from Independence, Mo. to St. Francisco, California by T.H. Jefferson, New York, 1849 (11 p., negative photocopy, folded in pocket, 16 cm.).LC Trails, 113"This map is in four parts and represents the emigrant road from Independence, Mo. by the South Pass of the Rocky Mountains to California. The author was one of a party of emigrants who travelled the road with waggons in 1846. All the streams of water and springs upon the road are delineated; also daily distances, courses and camps made by the party."--Printed on Part 1.Sheets labeled Part I, Part II, Part III, and Part IV.Includes notes and distance table.LC copy imperfect: Some acid-transfer. DLCLC copy quarter-bound in black leather with black and cream marbled board (42 cm.), map sheets mounted on linen. DL
Arakelian 564: An XMM-Newton View
No full textWe report on two XMM-Newton observations of the bright narrow-line Seyfert 1 galaxy Ark 564 taken one year apart (2000 June and 2001 June). The 0.6-10 keV continuum is well described by a soft blackbody component (kTau approximately equal 140-150 eV) plus a steep power law (Tau approximately equal to 2.50-2.55). No significant spectral changes are observed between the two observations, although the X-ray flux in the second observation is approximately equal to 40-50 per cent lower. In both observations we detect a significant absorption edge at a rest-frame energy of approximately equal to 0.73 keV, corresponding to O VII. The presence of the absorption feature is confirmed by a simultaneous Chandra grating observation in 2000 June, although the best-fitting edge threshold is at a slightly lower energy in the Chandra data, possibly because of a different parameterization of the underlying X-ray continuum. We find tentative evidence for a broad iron emission line in the 2000 June observation. The results from an analysis of the power spectral density (PSD) function are also presented. The present XMM-Newton data support the idea that the PSD shown two breads, although the location of the high-frequency break requires further constraints
XMM-Newton spectroscopy of highly polarized and luminous broad absorption line quasar CSO 755
No full text- …
