Crafting Exhibitions

Book reviewed in this article:
Crafting Exhibitions: Contemporary Navajo Weaving: The Gloria F. Ross Collection of the Denver Art Museum .
Crafting Exhibitions: Reflections of the Weavers' World: The Gloria F. Ross Collection of the Denver Art Museum .     

Crafting a career in molecular animation

When I first set out on a path to becoming a cell biologist, I would have never imagined that it would lead to a career in molecular animation. I had always thought I would follow a more traditional route. What happened? In this essay, I will describe the experiences that led to my decision to forge a career as an academic molecular animator, and how my work has evolved over the years. I will also provide some resources and advice for those who may be considering following a similar route.     

Crafting Grand Cra Chocolates in Contemporary France

C'est un magasin où le chocolat règne en maître, traité par un maître. C'est du travail cent pour cent artisanal au sens "artist" du terme, qui sait tirer de la sublime fève d'Amérique la substantifique splendeur.1     

Crafting fidelity: pedagogical creativity in kathak dance

Through a phenomenological account of apprenticeship in the North Indian dance form of kathak, I show how skills are adapted and changed through the ingenuity and innovation required in teaching to new generations of students. The traditional pedagogical model for learning in the Indian arts, the guru‐shishya parampara (master‐disciple relationship), has historically been based on imitative and repetitive pedagogies. Yet close examination reveals less conspicuous forms of creativity at work in the process of reproducing the tradition with fidelity; this improvisational work is further heightened in the demands of teaching in the diaspora. As teachers create opportunities for experiential learning, a spectrum of pedagogical tactics, scaffolding strategies, and coaching competencies are developed and accumulate as this tradition is passed on from one generation to the next. The pedagogical work in crafting fidelity can, in fact, produce its own kind of knowledge, which, ironically, can add new elements to the tradition in unexpected ways. In one unique case – the example of ‘kathak yoga’ – the pedagogical adaptations of kathak artist Pandit Chitresh Das elicited a creative response, a new scaffolding technique that would eventually be incorporated into the repertoire as a skill in itself. Pedagogical process, in this sense, was creative process.     

Self-assembly of minimal COPII cages

The small G-protein Sar1 and the cytosolic complexes Sec23/24 and Sec13/31 associate sequentially on endoplasmic reticulum membranes to form a protein coat named COPII, which drives the formation of transport vesicles. Using dynamic light scattering, we show that Sec23/24 and Sec13/31 can self-assemble in a stoichiometric manner in solution to form particles with hydrodynamic radii in the range of 40–60 nm. Self-assembly is favoured by lowering the pH, the ionic strength and/or the temperature. Electron microscopy reveals the formation of spherical particles 60–120 nm in diameter with a tight, rough mesh on their surfaces. We suggest that these stuctures, which represent a minimal COPII cage, mimic the molecular organization of the membrane-associated COPII coat.     

Design and structure of two new protein cages illustrate successes and ongoing challenges in protein engineering

In recent years, new protein engineering methods have produced more than a dozen symmetric, self‐assembling protein cages whose structures have been validated to match their design models with near‐atomic accuracy. However, many protein cage designs that are tested in the lab do not form the desired assembly, and improving the success rate of design has been a point of recent emphasis. Here we present two protein structures solved by X‐ray crystallography of designed protein oligomers that form two‐component cages with tetrahedral symmetry. To improve on the past tendency toward poorly soluble protein, we used a computational protocol that favors the formation of hydrogen‐bonding networks over exclusively hydrophobic interactions to stabilize the designed protein–protein interfaces. Preliminary characterization showed highly soluble expression, and solution studies indicated successful cage formation by both designed proteins. For one of the designs, a crystal structure confirmed at high resolution that the intended tetrahedral cage was formed, though several flipped amino acid side chain rotamers resulted in an interface that deviates from the precise hydrogen‐bonding pattern that was intended. A structure of the other designed cage showed that, under the conditions where crystals were obtained, a noncage structure was formed wherein a porous 3D protein network in space group I2₁3 is generated by an off‐target twofold homomeric interface. These results illustrate some of the ongoing challenges of developing computational methods for polar interface design, and add two potentially valuable new entries to the growing list of engineered protein materials for downstream applications.     

Modelling benthic deposition under fish cages

Simple models which predict the dispersion and input of organic waste from cage fish farms can be used as management tools for the siting of farms and assessing the potential for enrichment of the benthic ecosystem. A modification of the sediment model originally described by Gowen et al. (1988) is presented. The modifications include: variation in bottom topography; changes in current speed with depth; correction of horizontal current flow in response to changing depth. Data from a fish farm in Chile are used to compare simulations of dispersion and sediment loading from the original and modified models.     

Microclimate in two types of rat cages

The microclimate in two types of rat cages (a Makrolon type IV with a solid floor and a stainless steel cage with a wire mesh floor (five rats per cage)) placed in the same macro-environment was compared. The temperature, relative humidity and ammonia concentration in the cages were measured twice a day for 8 days. The cages were cleaned every 4 days. The greatest difference between the cage types was in the ammonia build-up. In Makrolon cages the ammonia concentration never reached 5 ppm, whereas in steel cages it showed a constant increase and already exceeded the threshold limit for man (25 ppm for 8 h per day) on the third day after cleaning.     

A forced-air ventilation system for rodent cages

A novel forced-air ventilation system for rodent cages was developed. The apparatus was operated at an air flow rate of 56 L/min when used with a 230 mm wide X 450 mm long X 165 mm deep cage. Air velocity measurements in the cage did not exceed 8 m/min at animal (rat) height. The average NH3 concentration in a cage which housed two 250 g rats was less than 0.3 ppm at the end of the third day, whereas the concentration measured in a cage without the forced-air ventilation system was 150 ppm after 3 days. Tests of the water content of soiled bedding showed the forced-air ventilation system to provide a much drier environment for the rodents.     

Actin cages isolate damaged mitochondria during mitophagy

Mitochondrial homeostasis is maintained by removing dysfunctional, ubiquitinated mitochondria from the network via PRKN-dependent mitophagy. MYO6, a unique myosin that moves towards the minus ends of actin filaments, forms a complex with PRKN and is selectively recruited to damaged mitochondria by binding to ubiquitin. On the mitochondrial surface, this myosin motor initiates the assembly of F-actin cages, which serve as a quality control mechanism to isolate dysfunctional mitochondria thereby preventing their refusion with neighboring populations. MYO6 also plays a role in the later stages of the mitophagy pathway by tethering endosomes to actin filaments facilitating mitophagosome maturation and autophagosome-lysosome fusion.