Immobilisation of hydroxynitrile lyases

Hydroxynitrile lyases are a versatile group of enzymes that are applied both in the laboratory and on an industrial scale. What makes them particularly interesting is that to date five structurally unrelated categories of hydroxynitrile lyases have been discovered. Given their great importance they have often been immobilised utilising many...

More efficient redox biocatalysis by utilising 1,4-butanediol as a ‘smart cosubstrate’

1,4-Butanediol is shown to be an efficient cosubstrate to promote NAD(P)H-dependent redox biocatalysis. The thermodynamically and kinetically inert lactone coproduct makes the regeneration reaction irreversible. Thereby not only the molar surplus of cosubstrate is dramatically reduced but also faster reaction rates are obtained.

Revealing hidden paint layers in oil paintings by means of scanning macro-XRF: A mock-up study based on Rembrandt's “An old man in military costume”

Over the past several decades the oeuvre of Rembrandt has been the subject of extensive art historical and scientific investigations. One of the most striking features to emerge is his frequent re-use of canvases and panels. The painting An Old Man in Military Costume (78.PB.246), in the collection of the J. Paul Getty Museum, is an example of...

Experimenteren met een Open Access Fonds

Om Open Access onder de eigen medewerkers te promoten, beschikt TU Delft over een Open Access Fonds. Wat heeft dit fonds de afgelopen jaren opgeleverd? Anke Versteeg en Just de Leeuwe bespreken de resultaten en belichten en passant ook nieuwe ontwikkelingen. Engelse versie is zonder tabellen en niet gepubliceerd

Towards Voluntary Interoperable Open Access Licenses for the Global Earth Observation System of Systems (GEOSS)

Access to earth observation data has become critically important for the wellbeing of society. A major impediment to achieving widespread sharing of earth observation data is lack of an operational web-wide system that is transparent and consistent in allowing users to legally access and use the earth observations of others without seeking...

Experts speak: Interview met Jacob Fokkema over Open Access

The fluxes through glycolytic enzymes in Saccharomyces cerevisiae are predominantly regulated at posttranscriptional levels

Metabolic fluxes may be regulated ‘‘hierarchically,’’ e.g., by changes of gene expression that adjust enzyme capacities (Vmax) and/or ‘‘metabolically’’ by interactions of enzymes with substrates, products, or allosteric effectors. In the present study, a method is developed to dissect the hierarchical regulation into contributions by...

On partitions, surjections, and Stirling numbers

A Functional Approach to the Stationary Waiting Time and Idle Period Distributions of the GI/G/1 Queue

The GI/G/1 queueing model is regarded as a functional which maps the service and interarrival time distributions onto output quantities of interest, such as the stationary waiting time distribution. For the case where the input distributions have densities, techniques from infinite-dimensional analysis are used to obtain derivatives and Taylor...

Density and uniqueness in percolation

Tail Triviality for Sums of Stationary Random Variables

We study tail $\sigma$-fields and loss of memory associated with sums of stationary integer-valued random variables. An application concerns convergence in distribution of interarrival times in zero-one sequences.

On the Uniqueness of the Infinite Occupied Cluster in Dependent Two- Dimensional Site Percolation

We consider dependent site percolation on the two-dimensional square lattice, the underlying probability measure being invariant and ergodic under each of the translations and invariant under axis reflections. If this measure satisfies the FKG condition and if percolation occurs, then we show that the infinite occupied cluster is unique with...

An Algebraic Construction of a Class of One-Dependent Processes

A special class of stationary one-dependent two-valued stochastic processes is defined. We associate to each member of this class two parameter values, whereby different members receive different parameter values. For any given values of the parameters, we show how to determine whether: 1. a process exists having the given parameter values, and...

On the uniqueness of the infinite cluster in the percolation model

We simplify the recent proof by Aizenman, Kesten and Newman of the uniqueness of the infinite open cluster in the percolation model. Our new proof is more suitable for generalization in the direction of percolation-type processes with dependent site variables.

One-dimensional dynamics: The Schwarzian derivative and beyond

Most of the important results in the study of the dynamics of smooth interval maps ƒ : [0,1] —• [0,1] assume the condition that S f < 0 where S f is the Schwarzian derivative of ƒ.