723 research outputs found
Chairs, bells and students – a novel method to simulate and teach molecular interactions in pharmacology
Background: Pharmacy education requires an understanding of the fundamental principles of molecular pharmacology. Among these, abstract concepts such as affinity, association and dissociation rates and partial agonism may be difficult to demonstrate to students. Aims: We wished to devise a method to simulate drug-receptor interactions that could readily be used in teaching sessions and that would promote student engagement. Methods: A role play was carried out in which drugs (represented by students) associate with receptors (represented by chairs) and cause signal transduction (represented by a bell ringing). By varying the parameters associated with the role play (e.g. time taken to sit in the chair and how often the bell is rung) fundamental principles of drug-receptor interactions could be modelled. Results: The simulation was considered by the students to improve their understanding of the intended learning outcomes. Conclusion: This simulation offers a method to introduce students to drug-receptor interactions in a manner that promotes their engagement
Chairs, bells and students – a novel method to simulate and teach molecular interactions in pharmacology
Background: Pharmacy education requires an understanding of the fundamental principles of molecular pharmacology. Among these, abstract concepts such as affinity, association and dissociation rates and partial agonism may be difficult to demonstrate to students. Aims: We wished to devise a method to simulate drug-receptor interactions that could readily be used in teaching sessions and that would promote student engagement. Methods: A role play was carried out in which drugs (represented by students) associate with receptors (represented by chairs) and cause signal transduction (represented by a bell ringing). By varying the parameters associated with the role play (e.g. time taken to sit in the chair and how often the bell is rung) fundamental principles of drug-receptor interactions could be modelled. Results: The simulation was considered by the students to improve their understanding of the intended learning outcomes. Conclusion: This simulation offers a method to introduce students to drug-receptor interactions in a manner that promotes their engagement
Influence of early postmortem protein oxidation on beef quality
The objective of this study was to examine the effect of early postmortem protein oxidation on the color and tenderness of beef steaks. To obtain a range of oxidation levels, the longissimus lumborum muscles (LM) from both strip loins of 20 steers fed either a finishing diet with vitamin E (1,000 IU per steer daily, minimum of 126 d [VITE]; n = 10 steers) or fed the same finishing diet without vitamin E (CON; n = 10 steers) were used. Within 24 h after slaughter, the LM muscle from each carcass was cut into 2.54-cm-thick steaks and individually vacuum packaged. Steaks from each steer were assigned to a nonirradiated group or an irradiated group. Steaks were irradiated within 26 h postmortem, and were aged at 4°C for 0, 1, 3, 7, and 14 d after irradiation. Steaks from each diet/irradiation/aging time treatment were used to determine color, shear force, and degree of protein oxidation (carbonyl content). Steaks from steers fed the VITE diet had higher (P \u3c 0.01) α-tocopherol contents than steaks from steers fed the CON diet. Immediately following irradiation, steaks that had been irradiated had lower (P \u3c 0.05) L* values regardless of diet. Irradiated steaks, regardless of diet, had lower a* (P \u3c 0.05) and b* (P \u3c 0.01) values than nonirradiated steaks at all aging times. Carbonyl concentration was higher (P \u3c 0.05) in proteins from irradiated steaks compared to nonirradiated steaks at 0, 1, 3, and 7 d postirradiation. Immunoblot analysis showed that vitamin E supplementation decreased the number and extent of oxidized sarcoplasmic proteins. Protein carbonyl content was positively correlated with Warner-Bratzler shear force values. These results indicate that increased oxidation of muscle proteins early postmortem could have negative effects on fresh meat color and tenderness
Level Sets of the Takagi Function: Local Level Sets
The Takagi function \tau : [0, 1] \to [0, 1] is a continuous
non-differentiable function constructed by Takagi in 1903. The level sets L(y)
= {x : \tau(x) = y} of the Takagi function \tau(x) are studied by introducing a
notion of local level set into which level sets are partitioned. Local level
sets are simple to analyze, reducing questions to understanding the relation of
level sets to local level sets, which is more complicated. It is known that for
a "generic" full Lebesgue measure set of ordinates y, the level sets are finite
sets. Here it is shown for a "generic" full Lebesgue measure set of abscissas
x, the level set L(\tau(x)) is uncountable. An interesting singular monotone
function is constructed, associated to local level sets, and is used to show
the expected number of local level sets at a random level y is exactly 3/2.Comment: 32 pages, 2 figures, 1 table. Latest version has updated equation
numbering. The final publication will soon be available at springerlink.co
Effects of thermal fluctuation and the receptor-receptor interaction in bacterial chemotactic signalling and adaptation
Bacterial chemotaxis is controlled by the conformational changes of the
receptors, in response to the change of the ambient chemical concentration. In
a statistical mechanical approach, the signalling due to the conformational
changes is a thermodynamic average quantity, dependent on the temperature and
the total energy of the system, including both ligand-receptor interaction and
receptor-receptor interaction. This physical theory suggests to biology a new
understanding of cooperation in ligand binding and receptor signalling
problems. How much experimental support of this approach can be obtained from
the currently available data? What are the parameter values? What is the
practical information for experiments? Here we make comparisons between the
theory and recent experimental results. Although currently comparisons can only
be semi-quantitative or qualitative, consistency is clearly shown. The theory
also helps to sort a variety of data.Comment: 26 pages, revtex. Journal version. Analysis on another set of data on
adaptation time is adde
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