180 research outputs found
Relational Contract Theory and Sovereign Debt
Relational contract theory will first be presented using principles gleaned from writings in the field 7 to craft a functional/relational model with which to approach legal practice.8 This version of relational contract will then be applied to the problem of developing country debt through description of a hypothetical sovereign loan relationship.9 By exploring the conflicts and trends of this association under a general taxonomy of relational contract, normative analysis of the restructuring process can be accomplished, contractual trends identified, and suggestions for change offered.\u2
Relational Contract Theory and Sovereign Debt
Relational contract theory will first be presented using principles gleaned from writings in the field 7 to craft a functional/relational model with which to approach legal practice.8 This version of relational contract will then be applied to the problem of developing country debt through description of a hypothetical sovereign loan relationship.9 By exploring the conflicts and trends of this association under a general taxonomy of relational contract, normative analysis of the restructuring process can be accomplished, contractual trends identified, and suggestions for change offered.\u2
Isolation of Photosystem II Reaction Center Complexes from Plants
18 Pags. The definitive version is available at: http://www.springerlink.com/content/1064-3745/Methods to isolate and purify 6- and 5-Chl D1/D2/Cyt b559 photosystem II (PSII) reaction center (RC) complexes from plants are presented, and the advantages and disadvantages of each procedure are discussed. One of the simpler 6-Chl procedures and a procedure for isolating 5-Chl complexes are described in detail. Furthermore, a rapid procedure that produces relatively large amounts of less pure 6-Chl material (i.e., more nonpigmented protein) is also described. Criteria to assess the purity of PSII RC preparations are presented, and problems associated with each of the isolation procedures are discussed.This work was supported by the Chemical
Sciences, Geosciences, and Biosciences Division, Office of Science, U.S. Department of Energy
(MS) and by the MCYT of Spain (Grant BFU2005-04722-C02-01 and AGL2008-00377) to RP.Peer reviewe
Evaluation of the tolerability of the Salmonella Typhimurium live vaccine Salmoporc® for oral administration in three day old piglets
Vaccination against Salmonella is a measure to reduce salmonella disease in pigs. In this study a S. Typhimurium live vaccine (Salmoporc®, lmpfstoffwerk Dessau-Tornau, Rosslau, Germany) was applied to 3 day old conventional piglets in order to investigate safety and persistence of the vaccine strain in different tissues. The results indicate that an early vaccination against Salmonella shall be deemed to be safe
MID-IR LED-based, Photoacoustic CO2 Sensor
AbstractThe technology used to implement CO2 sensors depends on the requirements in terms of sensitivity, price and robustness. The most common technology for highly sensitive tasks are based on tunable diode laser spectroscopy, while so-called non-dispersive infrared (NDIR) photometers [2] are used in less demanding scenarios such as control air conditioning systems. Most NDIR systems use thermal emitters as light source which are readily available at low cost but require compensation for cross-sensitivities toward other gas species. The detector technology employed in these systems ranges from photodiodes to thermopiles and pyroelectric detectors, all of which require the use of spectral filters to avoid cross sensitivities. Here we present a low-cost photoacoustic-based detector comprised of a microphone in a hermetically sealed chamber filled with CO2. To excite sound waves a MID-IR LED emitting radiation in the strong CO2 absorption region around 4.2ÎĽm is used for the first time
A trapped single ion inside a Bose-Einstein condensate
Improved control of the motional and internal quantum states of ultracold
neutral atoms and ions has opened intriguing possibilities for quantum
simulation and quantum computation. Many-body effects have been explored with
hundreds of thousands of quantum-degenerate neutral atoms and coherent
light-matter interfaces have been built. Systems of single or a few trapped
ions have been used to demonstrate universal quantum computing algorithms and
to detect variations of fundamental constants in precision atomic clocks. Until
now, atomic quantum gases and single trapped ions have been treated separately
in experiments. Here we investigate whether they can be advantageously combined
into one hybrid system, by exploring the immersion of a single trapped ion into
a Bose-Einstein condensate of neutral atoms. We demonstrate independent control
over the two components within the hybrid system, study the fundamental
interaction processes and observe sympathetic cooling of the single ion by the
condensate. Our experiment calls for further research into the possibility of
using this technique for the continuous cooling of quantum computers. We also
anticipate that it will lead to explorations of entanglement in hybrid quantum
systems and to fundamental studies of the decoherence of a single, locally
controlled impurity particle coupled to a quantum environment
Context-Dependent Behavior of the Enterocin Iterative Polyketide Synthase A New Model for Ketoreduction
AbstractHeterologous expression and mutagenesis of the enterocin type II polyketide synthase (PKS) system suggest for the first time that the association of an extended set of proteins and substrates is needed for the effective production of the enterocin-wailupemycin polyketides. In the absence of its endogenous ketoreductase (KR) EncD in either the enterocin producer “Streptomyces maritimus” or the engineered host S. lividans K4-114, the enterocin minimal PKS is unable to produce benzoate-primed polyketides, even when complemented with the homologous actinorhodin KR ActIII or with EncD active site mutants. These data suggest that the enterocin PKS requires EncD to serve a catalytic and not just a structural role in the functional PKS enzyme complex. This strongly implies that EncD reduces the polyketide chain during elongation rather than after its complete assembly, as suggested for most type II PKSs
Gas sensors for climate research
The availability of datasets providing information on the spatial and
temporal evolution of greenhouse gas concentrations is of high relevance for
the development of reliable climate simulations. However, current gas
detection technologies do not allow for obtaining high-quality data at
intermediate spatial scales with high temporal resolution. In this regard the
deployment of a wireless gas sensor network equipped with in situ gas
analysers may be a suitable approach. Here we present a novel, non-dispersive
infrared absorption spectroscopy (NDIR) device that can possibly act as a
central building block of a sensor node to provide high-quality data of
carbon dioxide (CO2) concentrations under field conditions at a
high measurement rate. Employing a gas-based, photoacoustic detector we
demonstrate that miniaturized, low-cost, and low-power consuming
CO2 sensors may be built. The performance is equal to that of
standard NDIR devices but at a much reduced optical path length. Because of
the spectral properties of the photoacoustic detector, no cross-sensitivities
to humidity exist.</p
On the Efetov-Wegner terms by diagonalizing a Hermitian supermatrix
The diagonalization of Hermitian supermatrices is studied. Such a change of
coordinates is inevitable to find certain structures in random matrix theory.
However it still poses serious problems since up to now the calculation of all
Rothstein contributions known as Efetov-Wegner terms in physics was quite
cumbersome. We derive the supermatrix Bessel function with all Efetov-Wegner
terms for an arbitrary rotation invariant probability density function. As
applications we consider representations of generating functions for Hermitian
random matrices with and without an external field as integrals over
eigenvalues of Hermitian supermatrices. All results are obtained with all
Efetov-Wegner terms which were unknown before in such an explicit and compact
representation.Comment: 23 pages, PACS: 02.30.Cj, 02.30.Fn, 02.30.Px, 05.30.Ch, 05.30.-d,
05.45.M
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