A Review of Diagramming in Systems Practice and How Technologies Have Supported the Teaching and Learning of Diagramming for Systems Thinking in Practice

The educational process arguably involves a mediated discourse between teachers and learners to aid sense or meaning making for both parties. That mediation, particularly in distance teaching models, is often done through the use of educational resources, whereby teachers develop and/or select the educational resources which the learners then study or engage with through purposeful activities. Some issues or topics are so complicated or complex that words or numbers may be insufficient to represent the meanings contained within them and this is particularly relevant to systems studies which examine complex adaptive systems. Equally diagrams can break out of the linear and systematic nature of printed text to show non-linear and systemic features. This latter trait has been enhanced through the emergence in recent years of digital technologies whereby hypertext and other web applications now make it easier to create dynamic and/or interactive diagrams. And yet there has been little recent research into the influence of such technologies on the learning of systems diagramming skills at a distance. These issues are examined through a review of the literature and the reporting of previously unpublished surveys within The Open University on the value of diagrams to systems studies and the role of technology in influencing the study of diagramming in the teaching of systems thinking in practice. This review indicates that diagrams are seen as an important feature of systems studies and that digital technology can be effective in supporting the teaching and learning of systems diagramming skills at a distance. It also notes that new investigations are needed to examine whether more recent developments in digital technologies have made them more effective and/or efficient for teaching and using such skills in practice.     

Light-dependent phosphorylation of the carboxy tail of mouse melanopsin

Melanopsin-based phototransduction is involved in non-image forming light responses including circadian entrainment, pupil constriction, suppression of pineal melatonin synthesis, and direct photic regulation of sleep in vertebrates. Given that the functions of melanopsin involve the measurement and summation of total environmental luminance, there would appear to be no need for the rapid deactivation typical of other G-protein coupled receptors. In this study, however, we demonstrate that heterologously expressed mouse melanopsin is phosphorylated in a light-dependent manner, and that this phosphorylation is involved in regulating the rate of G-protein activation and the lifetime of melanopsin’s active state. Furthermore, we provide evidence for light-dependent phosphorylation of melanopsin in the mouse retina using an in situ proximity ligation assay. Finally, we demonstrate that melanopsin preferentially interacts with the GRK2/3 family of G-protein coupled receptor kinases through co-immunoprecipitation assays. Based on the complement of G-protein receptor kinases present in the melanopsin-expressing retinal ganglion cells, GRK2 emerges as the best candidate for melanopsin’s cognate GRK.     

Annealing-induced interfacial toughening using a molecular nanolayer

Self-assembled molecular nanolayers (MNLs) composed of short organic chains and terminated with desired functional groups are attractive for modifying surface properties for a variety of applications. For example, organosilane MNLs are used as lubricants, in nanolithography, for corrosion protection and in the crystallization of biominerals. Recent work has explored uses of MNLs at thin-film interfaces, both as active components in molecular devices, and as passive layers, inhibiting interfacial diffusion, promoting adhesion and toughening brittle nanoporous structures. The relatively low stability of MNLs on surfaces at temperatures above 350-400 degrees C (refs 12, 13), as a result of desorption or degradation, limits the use of surface MNLs in high-temperature applications. Here we harness MNLs at thin-film interfaces at temperatures higher than the MNL desorption temperature to fortify copper-dielectric interfaces relevant to wiring in micro- and nano-electronic devices. Annealing Cu/MNL/SiO2 structures at 400-700 degrees C results in interfaces that are five times tougher than pristine Cu/SiO2 structures, yielding values exceeding approximately 20 J m(-2). Previously, similarly high toughness values have only been obtained using micrometre-thick interfacial layers. Electron spectroscopy of fracture surfaces and density functional theory modelling of molecular stretching and fracture show that toughening arises from thermally activated interfacial siloxane bridging that enables the MNL to be strongly linked to both the adjacent layers at the interface, and suppresses MNL desorption. We anticipate that our findings will open up opportunities for molecular-level tailoring of a variety of interfacial properties, at processing temperatures higher than previously envisaged, for applications where microlayers are not a viable option-such as in nanodevices or in thermally resistant molecular-inorganic hybrid devices.     

Biochemistry: a cadmium enzyme from a marine diatom

The ocean biota contains a vast reservoir of genomic diversity. Here we present the sequence and preliminary characterization of a protein that is a cadmium-containing carbonic anhydrase from the marine diatom Thalassiosira weissflogii. The existence of a cadmium enzyme in marine phytoplankton may indicate that there is a unique selection pressure for metalloenzymes in the marine environment, and our discovery provides a long-awaited explanation for the nutrient-like behaviour of cadmium in the oceans.     

On the action ofβ-melanocyte stimulating hormone (β-MSH) on spontaneous electric discharge of the transparent knife fish,G. eigenmannia

Résumé L'hormone mélanophorétique-MSH, à des concentrations de 0.1 à 0.2µg/ml dans l'eau de l'aquarium, produit une diminution de la fréquence des modifications spontanées de l'amplitude des décharges électriques du poissonG. eigenmannia. Ces résultats sont en accord avec les observations antérieures montrant divers effets de-MSH sur l'activité électrique du système nerveux central chez les mammifères.     

Teaching Diagramming at a Distance: Seeing the Human Wood Through the Technological Trees

The Systems Group at the Open University has always seen diagramming as an essential skill for students to learn and use properly if they are to become effective systems practitioners. However, teaching students at a distance to use diagramming effectively has posed challenges to both Lecturers and Students alike. While we have tried to provide some face-to-face opportunities to help teach this skill we have had to rely heavily on technological means most of the time. This paper reviews the role of diagramming in systems studies generally and specifically in Open University courses and assesses the advantages and disadvantages of the various technological methods used to teach diagramming over 30 years by the Systems Group. In so doing we try to determine how much the technology hinders or helps budding systems practitioners.