Graphical histories for visualization: supporting analysis, communication, and evaluation

Interactive history tools, ranging from basic undo and redo to branching timelines of user actions, facilitate iterative forms of interaction. In this paper, we investigate the design of history mechanisms for information visualization. We present a design space analysis of both architectural and interface issues, identifying design decisions and associated trade-offs. Based on this analysis, we contribute a design study of graphical history tools for Tableau, a database visualization system. These tools record and visualize interaction histories, support data analysis and communication of findings, and contribute novel mechanisms for presenting, managing, and exporting histories. Furthermore, we have analyzed aggregated collections of history sessions to evaluate Tableau usage. We describe additional tools for analyzing users’ history logs and how they have been applied to study usage patterns in Tableau.     

The binding of beta-casein to hydroxyapatite: the effect of phosphate content and location.

The elution behaviour of beta-casein from columns of hydroxyapatite has been studied and the effect examined of the enzymic addition of an extra phosphate residue. When the additional phosphate is located near pre-existing phosphate residues stronger binding to hydroxyapatite is observed. When the additional phosphate is remote from the pre-existing phosphates no increase in strength of binding is observed. It is suggested that the clustering of phosphate residues which characterizes alphas- and beta-caseins can be rationalized on the basis that it facilitates co-operative interactions between these phosphates and the Ca phosphate of the casein micelle and/or basic residues within casein polypeptide chains.     

Insight into kinetics and thermodynamics properties of multicomponent lead(II), cadmium(II) and manganese(II) adsorption onto Dijah-Monkin bentonite clay

Multicomponent adsorption of lead(II), cadmium(II) and manganese(II) by Nigerian Dijah-Monkin bentonite clay was investigated. The clay samples were characterized for elemental composition, cation exchange capacity and textural properties. Natural bentonite exhibits cation exchange capacity of 47.7?meq/100?g and specific surface area of 23.5?m²/g. Manganese(II) displays higher values of rate constant than lead(II) in multimetals adsorption. However, lead(II) is favorably adsorbed onto bentonite adsorbents at different concentrations studied. The multimetals adsorption onto bentonite clay samples is site selective and site specific. The pseudo-second-order kinetics model gave a better fit to the adsorption data, suggesting ion exchange and/or complex formation. The adsorption mechanism could be described by intraparticle diffusion with some restriction of metals diffusion due to film or boundary layer. Also, the multicomponent adsorption is endothermic and becomes more spontaneous as temperature increased from 303 to 338?K. Nigerian bentonite clay in its natural form is a promising adsorbent for multimetals removal in aqueous solution.     

Graft site and gonadotrophin stimulation influences the number and quality of oocytes from murine ovarian tissue grafts

Ovarian tissue cryopreservation and subsequent transplantation can restore fertility in cancer patients. This study used a mouse ovarian grafting model to investigate whether the graft site (bursal cavity, the kidney capsule or subcutaneous) influences the number, fertilization rate and developmental potential of oocytes recovered from grafts and whether using a standard gonadotrophin stimulation protocol would increase oocyte yield from the grafts. Mouse ovarian tissue was grafted into four week old mice and collected three weeks later. Graft recipients were treated either with or without exogenous gonadotrophin stimulation prior to graft collection. Grafted ovaries yielded oocytes that were either at the germinal vesicle (GV) stage or mature metaphase II (MII) stage at collection. These GV oocytes were matured before in vitro fertilization (IVF), while the MII oocytes underwent IVF immediately. Oocytes collected from the oviducts of non-grafted superovulated mice of the same age served as controls. Two-cell embryos were transferred to pseudopregnant recipients and recovered at day 15 of gestation or left to go to term. Graft retrieval and the number of oocytes from each graft were lowest from the subcutaneous graft site. The number of two-cell embryos produced was significantly higher for oocytes from the grafts to the bursa as compared with the other sites. All graft sites gave rise to embryos with comparable implantation rates and developmental potential to fetuses and offspring following transfer. However, the oocytes from grafted ovaries had a significantly lower developmental potential when compared with the control group. Stimulation with exogenous gonadotrophins did not significantly increase oocyte yield from grafted ovaries but did enhance oocyte maturation and development. In conclusion, graft site affects the number and quality of oocytes produced from ovarian grafts.     

A method for aggregating state variables in large ecosystem models

Simplifying large ecosystem models is essential if we are to understand the underlying causes of observed behaviours. However, such understanding is often employed to achieve simplification. This paper introduces a method for model simplification that can be applied without requiring intimate prior knowledge of the system. Its utility is measured by the resulting values of given model diagnostics relative to those of the original model. The method uses a least-squares criterion to identify sets of state variables that can be aggregated, and then generates a modified model structure and accompanying parameters that enable these variables to be replaced with the aggregates. The method is applied to a model of the nitrogen cycle in Port Phillip Bay, Victoria, Australia. Aside from reducing the model’s order, the method enables the reduced model to retain an ecological interpretation, and reveals insights into the system’s structure.     

VLSI and software engineering: Guest editor's introduction

This paper describes an IEEE Computer Society Workshop on the subject of VLSI and Software Engineering and introduces five papers that were generated as a result of the workshop. Also presented here are some thoughts on parallels between the two disciplines.     

Surface modification of low-cost bentonite adsorbents—A review

The growth of science and technology over the world has led to the establishment of various industries which has helped the industrial, technological, and agricultural development of many nations. Environmental pollution from a variety of toxic derivatives, particularly heavy metals and minerals, aromatic molecules and dyes in wastewater posed a great danger to human, plants, and aquatic creatures. Adsorption appears to be the most widely used method among other techniques for the removal of toxic compounds from wastewater. The use of different adsorbents for heavy metal removal has become a subject of great interest, and there have been continuous efforts to develop new, low-cost, and efficient adsorbent materials. Bentonite, in natural and modified forms, has been applied in the removal of different water contaminants. This paper provides a review on recent progress of surface modifications of bentonite and their applications in the removal of organic and inorganic water pollutants. A comparison on the physicochemical characteristics and removal performance was presented. The adsorption mechanisms in relation to the bentonite properties were briefly discussed to offer readers some insight on the usefulness of this clay mineral in wastewater treatment. The challenges encountered and remarks on future prospects were highlighted.     

Show me: automatic presentation for visual analysis

This paper describes Show Me, an integrated set of user interface commands and defaults that incorporate automatic presentation into a commercial visual analysis system called Tableau. A key aspect of Tableau is VizQL, a language for specifying views, which is used by Show Me to extend automatic presentation to the generation of tables of views (commonly called small multiple displays). A key research issue for the commercial application of automatic presentation is the user experience, which must support the flow of visual analysis. User experience has not been the focus of previous research on automatic presentation. The Show Me user experience includes the automatic selection of mark types, a command to add a single field to a view, and a pair of commands to build views for multiple fields. Although the use of these defaults and commands is optional, user interface logs indicate that Show Me is used by commercial users.