No description available.

Abstract The food spoilage potential of the genus Chryseobacterium has not been studied in equal detail than the taxonomy of this genus. The ability of seven Chryseobacterium species to produce biogenic amines (BAs) at different temperatures and sodium chloride concentrations, was investigated by using amodified Niven medium. Temperatures at and below 15C and 25C seemed to have a definite inhibitory effect on the production of BAs in some Chryseobacterium species. Salt concentrations in excess of 4% would be needed to prevent amine production of Chryseobacterium species in food products. Chryseobacterium species have therefore the ability to decarboxylate some precursors of BAs, making them important spoilage bacteria in dairy food products.

No description available.

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 197-208). Available also in a digital version from Dissertation Abstracts.

No description available.

digitalisering@umu

Trace amines (TAs), tryptamine, tyramine, octopamine, and beta-phenylethylamine, named for their low endogenous concentrations in mammals, are related to the classical monoamine transmitters, but have been understudied and thought of as false transmitters. They share structural, physiological, pharmacological, and metabolic similarities with the monoamines, including synthesis by the aromatic-L-amino acid decarboxylase (AADC) enzyme. In 2001, a new class of receptors preferentially activated by the TAs, termed trace amine-associated receptors (TAARs), was discovered establishing a mechanism for TA actions independent of classic monoaminergic mechanisms. While the TAs and some of their receptors are present in the mammalian central nervous system (CNS), their physiologic role remains uncertain. I hypothesized that the TAs are found intrinsically in the spinal cord, and that they are able to modulate spinal neural networks. Using immunohistochemistry, numerous spinal neurons were identified that express AADC, TAs, and TAARs. Similar results were seen for AADC and TAAR1 with in situ hybridization. The most consistent observation was for labeling D cells associated with the central canal and in motoneurons. Overall, these results provided evidence for the presence of an anatomical substrate onto which the TAs could have intrinsic biological actions in the spinal cord. Using exogenous application of the TAs in the isolated spinal cord in vitro, and in vivo in the mid-thoracic chronically spinalized, I showed that the TAs could induce rhythmic locomotor-like activity. TA injection-induced hindlimb motor rhythms observed in chronic spinalized animals, supports TA spinal actions independent of the descending monoaminergic systems. In the presence of NMDA, TA applications recruited a variety of rhythmic motor patterns in the isolated spinal cord. This ranged from locomotor activity indistinguishable from 5-HT/NMDA induced locomotion to complex patterns including, an episodic form of locomotion where there were locomotor bouts with intervening quiescent periods. TA actions of pattern generating circuits had slower kinetics of activation than 5-HT and NA, were attenuated in the presence of monoamine transport inhibitors, and had increased intracellular labeling when incubated in a nominally Na+-free solution. Together these results suggest that the TAs require transport into neurons to exert their actions, and that transport occurs by Na+-dependent monoamine transporters as well as Na+-independent transporters. Finally, I used the in vitro isolated spinal cord with attached hindlimbs to record electromyographic (EMG) activity from various hindlimb muscles to compare the relationship between the TAs and serotonin (5-HT) evoked motor coordination and to examine the ability of the TAs to modulate ongoing 5-HT and NMDA locomotor-like activity. The TAs produced both the continuous and episodic patterns on muscles as observed in ventral root recordings, but EMG recordings provided more detailed insight into specific muscle actions. The TAs also generally increased both frequency and amplitude of ongoing 5-HT locomotor frequency, with tyramine and octopamine also particularly able to alter 5-HT motor coordination patterns.

Thesis (MScAgric)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Dissertation (Ph.D.)--University of Toledo, 2007. / Typescript. "Submitted as partial fulfillment of the requirements for The Doctor of Philosophy iin Biology." Bibliography: leaves 96-105.

In this study, we experimentally elevated levels of octopamine and serotonin in an orb-weaving spider, and observed the effects on the antipredator behavior thanatosis (death feigning), activity level, and running speed. We found that octopamine significantly shortened the duration of thanatosis, and its effect wore off over 24 h. We also found that serotonin significantly lengthened thanatosis, but in this case, the effect persisted for over 24 h. Neither octopamine nor serotonin affected the general activity or running speed of the spiders. To our knowledge, this is the first study to directly explore the role of biogenic amines on a specific antipredator behavior in spiders. Given that spiders must be both aggressive toward prey, yet wary of predators, we believe that this system will be an outstanding model to explore connections between behavioral ecology and neurochemistry.