The kynurenine pathway and the brain: challenges, controversies and promises

Research on the neurobiology of the kynurenine pathway has suffered years of relative obscurity because tryptophan degradation, and its involvement in both physiology and major brain diseases, was viewed almost exclusively through the lens of the well-established metabolite serotonin. With increasing recognition that kynurenine and its metabolites can affect and even control a variety of classic neurotransmitter systems directly and indirectly, interest is expanding rapidly. Moreover, kynurenine pathway metabolism itself is modulated in conditions such as infection and stress, which are known to induce major changes in well-being and behaviour, so that kynurenines may be instrumental in the etiology of psychiatric and neurological disorders. It is therefore likely that the near future will not only witness the discovery of additional physiological and pathological roles for brain kynurenines, but also ever-increasing interest in drug development based on these roles. In particular, targeting the kynurenine pathway with new specific agents may make it possible to prevent disease by appropriate pharmacological or genetic manipulations. The following overview focuses on areas of kynurenine research which are either controversial, of major potential therapeutic interest, or just beginning to receive the degree of attention which will clarify their relevance to neurobiology and medicine. It also highlights technical issues so that investigators entering the field, and new research initiatives, are not misdirected by inappropriate experimental approaches or incorrect interpretations at this time of skyrocketing interest in the subject matter

Recursive strategy for decomposing Betti tables of complete intersections

We introduce a recursive decomposition algorithm for the Betti diagram of a complete intersection using the diagram of a complete intersection defined by a subset of the original generators. This alternative algorithm is the main tool that we use to investigate stability and compatibility of the Boij-Soederberg decompositions of related diagrams; indeed, when the biggest generating degree is sufficiently large, the alternative algorithm produces the Boij-Soederberg decomposition. We also provide a detailed analysis of the Boij-Soederberg decomposition for Betti diagrams of codimension four complete intersections where the largest generating degree satisfies the size condition

Eroding ribbon thermocouples: impulse response and transient heat flux analysis

We have investigated a particular type of fast-response surface thermocouple to determine if it is appropriate to use a one dimensional transient heat conduction model to derive the transient surface heat flux from the measurements of surface temperature. With these sensors, low thermal inertia thermocouple junctions are formed near the surface by abrasive wear. Using laser excitation, we obtained the impulse response of these commercially available devices. The response of particular sensors can vary if new junctions are created by abrasive wear. Furthermore, the response of these sensors was found to deviate substantially from the one dimensional model and varied from sensor to sensor. The impulse response was simulated with greater fidelity using a two dimensional finite element model, but three dimensional effects also appear to be significant. The impact of these variations on the derived heat flux is assessed for the case of measurements in an internal combustion engine. When the measured impulse response is used to derive the surface heat flux, the apparent reversal of heat flux during the expansion stroke does not occur

Mass Round-Up Urinalysis and Original Intent

On Constitution Day, September 17, 1986, forty-eight days before the national elections, the Federal Register published President Ronald Reagan\u27s Executive Order 12564, Drug-Free Federal Workplace, ordering all agencies in the Executive Branch to develop and implement plans to collect and test urine from all government employees in sensitive positions

Representation of numerical information : exploration of the category structure of distributions of numerical stimuli.

A series of experiments explored the nature of the memory representation of numerical information. Two distributions were presented to each subject as three-digit numbers paired with distribution labels. Three stimulus presentation conditions were used in Experiment 1: a rapid serial presentation as used in Malmi and Samson (1983); a task which requires the subject to retype each stimulus item; and a classification task in which the subject must supply the category name when presented with the stimulus number. In Experiment 1, subjects estimated the averages of the distributions they were presented. In Experiment 2, subjects classified an additional 40 items, chosen to enable discrimination between two classes of models of memory representation. Subjects in Experiment 3 made estimates of the frequency of scores per decade for each distribution. The results strongly favor the category density model (Fried and Holyoak, 1984), a model which assumes that the subject abstracts distributional information and uses a default \u27normal\u27 distribution to organize the incoming information. The Nosofsky (1988) exemplar similarity model did not predict subject classification behavior or subject frequency estimation as accurately as the category density model. Reasons for these findings are discussed

The general biology of Verruca stroemia (O.F. Muller) with some additional observation on penis development and moulting frequency in Balanus balanoides.

First paragraph: This thesis is largely concerned with the biology of Verruca stroemia (O.F. Mulller), a common species of the sublittoral and near-littoral of the eastern Atlantic. A small animal even when fully grown, it is not very conspicuous, and there is very little information on its general biology. V. stroemia is the only easily accessible species of the genus, all others being found only in relatively deep water. Two features of its biology are of particular interest: first, although boreo-arctic in its distribution it is not, like some other species of similar geographical distribution, restricted to a single annual brood; secondly, the genus Verruca is a primitive one, in many respects more closely allied to the Lepadomorpha than to the Balanomorpha with which it is classified. Both these aspects of the species have been considered, the latter particularly with reference to feeding and cirral activity. The relation of the major nauplii release to the spring diatom outburst and the effects of desiccation have been investigated since these are important in the ecology of the species and there is much comparative data on both for other cirripedes