Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Behavior Control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 865 records · Page 48Linked to original sources
PubMed1978

Potential and structure controlled interfacial behavior of uracil derivatives.

The adsorption and related interfacial behavior of uracil, various methylated uracil derivatives, uridine, uridine-5'-monophosphate and uridine-3'5'-cyclic monophosphate has been studied by surface electrochemical measurements at a mercury electrode. All uracil derivatives exhibit an initial "dilute" adsorption region where the virtually flat uracil residue is absorbed flat on the electrode surface. In the case of uracil and its methylated derivatives the area occupied by one molecule is about 60-70 A2. Uracil, thymine and 1,5-dimethyluracil exhibit a second adsorption region where they rearrange on the surface and adopt a perpendicular orientation and occupy about 40 A2 per molecule. In this perpendicular orientation the uracils are bound to the electrode through the N(3)-H or perhaps N(1)-H functions in a manner similar to their Watson-Crick bonding in nucleic acids. When in the perpendicular orientation the adsorbed molecules undergo extensive stacking (association) interactions, again similar to those observed between adjacent bases in nucleic acids. The ability of a uracil derivative to undergo a surface reorientation is critically dependent on electrode potential, bulk-solution concentration and molecular structure.

Electrodes↗
PubMed1993

Aromatase: neuromodulator in the control of behavior.

Estrogens are required for both the organization of the brain in early development and adult behavior. Two approaches have been used in our laboratory to study the behavioral role of brain aromatase. First, brain metabolism of testosterone (T) has been related to behavior in the same individual using a well established neuroendocrine model, the ring dove, in which estradiol-17 beta (E2) has specific effects on brain mechanisms of male behavior. Aromatase in preoptic area (POA) (a) has a high activity (Vmax) and strong substrate binding affinity (Km < 5 nM), (b) is regulated by both androgens and estrogens, and the type of regulation differs according to brain area, (c) is influenced by products of an endogenous inactivating pathway, 5 beta-reduction; 5 beta-dihydrotestosterone and other 5 beta-reduced metabolites appear to be non-genomic regulators of the brain aromatase. Preoptic aromatase activity is also influenced by photoperiod and socio-sexual stimuli. The codistribution of regulated aromatase activity and estrogen receptor cells is found to be T-dependent. Our second approach has been to relate the aromatase system to developmental sex differences in brain structure and behavior of the Mongolian gerbil. Neonatal gerbil aromatase is relatively active in the POA, but has a weaker T substrate-binding affinity (Km = 30 nM) than the dove. T acting via its metabolite, E2, masculinizes the sexually dimorphic area of the hypothalamus; the differentiating effect is asymmetric. We suggest that the regulation of the brain aromatase system may be lateralized during steroid-sensitive periods of development.

Animals↗
PubMed2005

Analysis of motor control and behavior in multi agent systems by means of artificial neural networks.

This article gives a short introduction to Self-Organizing Maps, a particular form of Artificial Neural Networks and shows by some examples, how these approaches can be used in order to analyze and visualize time series data originating from complex systems. The methods shown in this article have originally been developed for the analysis of RoboCup robot soccer games, a special kind of so-called Multi Agent Systems. Although this application has no direct connection to biomechanics, the examples shown here may give an impression of the abilities of Neural Networks in the field of Time Series Analysis in general. Because of the abstractness of the methods, it appears to be very likely that they can easily be adapted to Time Series Analysis problems within the biomechanics context.

Algorithms↗
PubMedDate not supplied

Competing stimuli in the treatment of multiply controlled problem behavior during hygiene routines.

The current study describes the use of noncontingent competing stimuli in the treatment of problem behavior exhibited by three individuals during staff-assisted hygiene routines. Functional analyses revealed that particular topographies of problem behaviors appeared to be maintained by their own sensory consequences, whereas other topographies appeared to be maintained by escape from demands. Competing stimulus assessments were then conducted to identify items associated with low levels of automatically-maintained problem behavior and high levels of stimulus engagement. Stimuli associated with low levels of automatically-maintained problem behavior (competing stimuli) were then delivered noncontingently during staff-assisted hygiene routines that were problematic for each participant. In all three cases, substantial reductions in all problem behaviors were observed. These results are discussed in terms of the relative ease of this intervention and possible mechanisms underlying the effects of competing stimuli on behaviors maintained by different types of reinforcement.

Activities of Daily Living↗
PubMed2001

Command and control: regulatory pathways controlling invasive behavior of the border cells.

The invasiveness of cancer cells resembles the normal behavior of cells that migrate into surrounding tissues during development. For example, the border cells in the Drosophila ovary undergo a partial epithelial to mesenchymal transition and invade the neighboring cluster of germline cells, migrating to the oocyte border. Once there, they provide patterning information to the oocyte and produce an eggshell specialization known as the micropyle. Border cell migration has been subjected to extensive genetic analyses using a variety of screening approaches. Recent findings demonstrate that conversion of the border cells from a stationary group of epithelial cells to invasive cells requires integration of the activities of at least two transcriptional regulatory pathways. One such pathway requires the slbo gene, which encodes Drosophila C/EBP, a basic region/leucine zipper transcriptional activator that is required for elevated expression of a number of downstream targets, including DE-cadherin and focal adhesion kinase (FAK). An independent pathway requires the activity of the ecdysone receptor and a recently identified co-activator for the ecdysone receptor known as Taiman (abbreviated TAI, pronounced ti-maan', meaning too slow). Ecdysone is produced in the Drosophila ovary in response to adequate nutrition and is required for progression of oogenesis through stage 9, when border cell migration occurs. Border cells mutant for tai accumulate abnormally high levels of adhesion complexes at their surfaces, which may account for their inability to migrate. Thus border cell migration requires a differentiation program mediated by the C/EBP pathway, which is required for elevated expression of a number of proteins required for motility. In addition, migration requires a hormonal signal that relays information regarding nutritional status and appears to be required for regulation of the proper localization of some of the C/EBP targets. These findings suggest that steroid hormones can regulate cell motility relatively directly, independent of the effects on proliferation. This may contribute to the metastatic effects of steroid hormones on certain cancers and the inhibition of metastasis by steroid hormone antagonists such as tamoxifen.

Animals↗
PubMed1991

Sensory control of behavior in electric fish.

The electrosensory system is ideally suited for the integration of behavioral and cellular approaches and, therefore, has led to the most detailed explanations of natural behaviors at the single-cell level. The electric sense shares basic principles in the coding of sensory information with more advanced sensory modalities and thus provides a convenient model system for studying neuronal mechanisms of information processing in general.

Animals↗
PubMedDate not supplied

Muscarinic receptors of the neostriatum--their role in controlling operant behavior in dogs.

Chronic experiments were performed on six dogs to study the effects of bilateral microinjections of muscarinic receptor agonists and blockers into the dorsal striatum on the performance of an operant defensive reflex consisting of maintenance of a specified posture and on the differentiation of stimuli. Microinjections of carbachol, a non-selective agonist of muscarinic receptors, were accompanied by increases in the tonic component of movements, inhibition of phasic movements, ordering of the postural rearrangement, and increases in the amplitudes of its components. Bilateral microinjections of the selective agonist oxotremorine into the neostriatum had significantly weaker effects on the amplitude of postural rearrangement, generally decreasing the amplitude. Although oxotremorine also increased the tonic component of the operant response, this effect was weaker than that seen with carbachol microinjections. In addition, oxotremorine, unlike carbachol increased the number of intersignal limb elevations. These data, along with data published in the literature, are used to suggest the hypothesis that the actions of oxotremorine are mediated not only via muscarinic M2 but also via M1 receptors in the neostriatum. Stronger changes in responses to differential stimuli were also obtained after microinjection of the non-selective agonist carbachol than after microinjection of oxotremorine, and the fact that changes in responses to differential stimuli were significantly greater than changes in those to defensive stimuli suggests that microinjections of muscarinic M1 and M4 receptor agonists into the striatum are also accompanied by improvements in attention to significant stimuli.

Animals↗