Domestic horses (Equus ferus caballus) fail to intuitively reason about object properties like solidity and weight.

From early infancy, humans reason about the external world in terms of identifiable, solid, cohesive objects persisting in space and time. This is one of the most fundamental human skills, which may be part of our innate conception of object properties. Although object permanence has been extensively studied across a variety of taxa, little is known about how non-human animals reason about other object properties.

2-micron vectors containing the Saccharomyces cerevisiae metallothionein gene as a selectable marker: excellent stability in complex media, and high-level expression of a recombinant protein from a CUP1-promoter-controlled expression cassette in cis.

We have constructed 2-micron-based yeast expression vectors containing a copy of the metallothionein (CUP1) gene of Saccharomyces cerevisiae as a semi-dominant, selectable marker. When used for the expression of the thrombin inhibitor hirudin, originally derived from the leech Hirudo medicinalis, these vectors displayed the following characteristics. (1) In the presence of copper salts, they were mitotically more stable than similarly designed control vectors lacking the CUP1 gene.

Fibre-optic biosensor for hypoxanthine and xanthine based on a chemiluminescence reaction.

Fibre-optic biosensors were constructed for determination of hypoxanthine and xanthine. Xanthine oxidase and peroxidase were immobilized on different preactivated membranes which were subsequently mounted onto the tip of a fibre-optic bundle. The H2O2 generated by the reaction of hypoxanthine and xanthine oxidase was measured by chemiluminescence (CL) detection using luminol and peroxidase.

An integrated silicon thermophile as biosensor for the thermal monitoring of glucose, urea and penicillin.

A new kind of calorimetric biosensor for the measurement of the heat (molar enthalpy change) of enzymatic reactions is presented. The device operates according to the Seebeck effect, the same principle on which thermocouples are based. The thermopile used in this work consists of an array of p-type silicon/aluminium strips integrated on a thin silicon membrane (5 microns).

Flow injection analysis and in-line biosensors for bioprocess control: a comparison.

Miniaturization will unify the different approaches chosen for the application of biosensors in bioprocess control. The most versatile system, which in our opinion is flow injection analysis will be the method of choice for the introduction of biosensors in bioprocess control. A lot of experience will be gained for the future development of miniaturized total chemical analysis systems.

Amperometric determination of phosphate by use of a nucleoside phosphorylase-xanthine oxidase enzyme sensor based on a Clark-type hydrogen peroxide or oxygen electrode.

A bienzymatic sensor for the determination of phosphate was constructed by coimmobilization of xanthine oxidase (EC 1.2.3.

Oxidation of benzo(a)pyrene by extracellular ligninases of Phanerochaete chrysosporium. Veratryl alcohol and stability of ligninase.

Benzo(a)pyrene was oxidized with crude and purified extracellular ligninase preparations from Phanerochaete chrysosporium. Both the crude enzyme and the purified fractions oxidized the substrate to three organic soluble products, namely benzo(a)pyrene 1,6-, 3,6-, and 6,12-quinones. These findings support the recent proposition that lignin-degrading enzymes are peroxidases, mediating oxidation of aromatic compounds via aryl cation radicals.