Correct Understanding (correct + understanding)

Distribution by Scientific Domains

Selected Abstracts

Islet adaptation to insulin resistance: mechanisms and implications for intervention

B. Ahrén
Abstract:, Insulin sensitivity and insulin secretion are reciprocally related such that insulin resistance is adapted by increased insulin secretion to maintain normal glucose and lipid homeostasis. The relation between insulin sensitivity and secretion is curvilinear and mathematically best described as a hyperbolic relation. Several potential mediators have been suggested to be signals for the beta cells to respond to insulin resistance such as glucose, free fatty acids, autonomic nerves, fat-derived hormones and the gut hormone glucagon-like peptide-1 (GLP-1). Failure of these signals or of the pancreatic beta cells to adequately adapt insulin secretion in relation to insulin sensitivity results in inappropriate insulin levels, impaired glucose intolerance (IGT) and type 2 diabetes. Therefore, treatment of IGT and type 2 diabetes should aim at restoring the normal relation between insulin sensitivity and secretion. Such treatment includes stimulation of insulin secretion (sulphonylureas, repaglinide and nateglinide) and insulin sensitivity (metformin and thiazolidinediones), as well as treatment aimed at supporting the signals mediating the islet adaptation (cholinergic agonists and GLP-1). Both, for correct understanding of diabetes pathophysiology and for development of novel treatment modalities, therefore, the non-linear inverse relation between insulin sensitivity and secretion needs to be acknowledged. [source]

Range error detection caused by occlusion in non-coaxial LADARs for scene interpretation

Bingbing Liu
When processing laser detection and ranging (LADAR) sensor data for scene interpretation, for example, for the purposes of feature extraction and/or data association in mobile robotics, most previous work models such devices as processing range data which follows a normal distribution. In this paper, it is demonstrated that commonly used LADARs suffer from incorrect range readings at changes in surface reflectivity and/or range discontinuities, which can have a much more detrimental effect on such algorithms than random noise. Most LADARs fall into two categories: coaxial and separated transmitter and receiver configurations. The latter offer the advantage that optical crosstalk is eliminated, since it can be guaranteed that all of the transmitted light leaves the LADAR and is not in any way partially reflected within it due to the beam-splitting techniques necessary in coaxial LADARs. However, they can introduce a significant disparity effect, as the reflected laser energy from the target can be partially occluded from the receiver. As well as demonstrating that false range values can result due to this occlusion effect from scanned LADARs, the main contribution of this paper is that the occurrence of these values can be reliably predicted by monitoring the received signal strength and a quantity we refer to as the "transceiver separation angle" of the rotating mirror. This paper will demonstrate that a correct understanding of such systematic errors is essential for the correct further processing of the data. A useful design criterion for the optical separation of the receiver and transmitter is also derived for noncoaxial LADARs, based on the minimum detectable signal amplitude of a LADAR and environmental edge constraints. By investigating the effects of various sensor and environmental parameters on occlusion, some advice is given on how to make use of noncoaxial LADARs correctly so as to avoid range errors when scanning environmental discontinuities. © 2005 Wiley Periodicals, Inc. [source]

A study investigating obstetricians' and gynaecologists' management of women requesting an intrauterine device

Kirsten I. BLACK
Background:, Intrauterine methods including the copper intrauterine device (Cu-IUD) and the levonorgestrel intrauterine system (LNG-IUS) provide highly effective long-term reversible contraception. The reasons for relative low use of these methods in Australia compared to many European countries are not clear, but may in part relate to provider reluctance because of outdated knowledge about their safety and efficacy. Aims:, The aim of this study was to survey Australian Fellows of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists about their knowledge of the risks, benefits and mechanisms of action of intrauterine methods. Methods:, In 2008, we undertook a cross-sectional survey of all Australian Fellows not registered as a subspecialist. The survey was mailed to 1050 practitioners and 701 were returned, comprising a response rate of 67%. Results:, Knowledge about the LNG-IUS was significantly better than for the Cu-IUD in terms of correct understanding about mechanism of action (89.3% vs. 30%; P < 0.001) and efficacy (63.2% vs. 33.5%; P < 0.001). According to the WHO, both methods are considered suitable for use in nulliparous women, yet only 39.1% of providers believed the Cu-IUD suitable compared to 69.4% for the LNG-IUS (P < 0.001). When responses were analysed according to time from graduation, many aspects of knowledge about these devices showed a linear trend, with greater accuracy in recent graduates (<10 years) compared with graduates of more than 30 years. Conclusion:, Both methods are highly effective, non-user dependent and reversible and deserve greater understanding and consideration for use by Australian practitioners and women. [source]

You be the examiner!

"Model answers" that require critical thinking
Abstract "You be the examiner!" is an online approach to providing students with immediate, readily accessible, and nonthreatening feedback on their understanding of key biochemical concepts. The feedback aims to affirm correct understanding and, where further study appears necessary, direct the student to the relevant sections of their textbook and/or lecturer-provided study notes. Rather than providing model answers to previous examination questions, "You be the examiner" asks the students to evaluate typical "student" answers to such questions. Instead of a single "correct" answer, students encounter a range of answers that they must assess for accuracy and appropriateness. [source]