Cognitive and learning difficulties and how they affect access to IT systems

In October 2005, the IBM Human Ability and Accessibility Center and T.J. Watson Research Center hosted a symposium on “cognitive and learning difficulties and how they affect access to IT systems”. The central premise of the symposium was the recognition that cognitive and learning difficulties have a profound impact on a person’s ability to interact with information technology (IT) systems, but that little support is currently being offered by those systems. By bringing together internationally renowned experts from a variety of different, but complementary, research fields, the symposium aimed to provide a complete overview of the issues related to this topic. This paper summarises the discussions and findings of the symposium.     

Toward Scalable Fabrication of Hierarchical Silica Capsules with Integrated Micro‐, Meso‐, and Macropores

Hierarchical porous structures are ubiquitous in biological organisms and inorganic systems. Although such structures have been replicated, designed, and fabricated, they are often inferior to naturally occurring analogues. Apart from the complexity and multiple functionalities developed by the biological systems, the controllable and scalable production of hierarchically porous structures and building blocks remains a technological challenge. Herein, a facile and scalable approach is developed to fabricate hierarchical hollow spheres with integrated micro‐, meso‐, and macropores ranging from 1 nm to 100 μm (spanning five orders of magnitude). (Macro)molecules, micro‐rods (which play a key role for the creation of robust capsules), and emulsion droplets have been successfully employed as multiple length scale templates, allowing the creation of hierarchical porous macrospheres. Thanks to their specific mechanical strength, these hierarchical porous spheres could be incorporated and assembled as higher level building blocks in various novel materials.     

Label Transfer Reagents to Probe p38 MAPK Binding Partners

Protein kinases are essential enzymes for cellular signaling, and are often regulated by participation in protein complexes. The mitogen‐activated protein kinase (MAPK) p38 is involved in multiple pathways, and its regulation depends on its interactions with other signaling proteins. However, the identification of p38‐interacting proteins is challenging. For this reason, we have developed label transfer reagents (LTRs) that allow labeling of p38 signaling complexes. These LTRs leverage the potency and selectivity of known p38 inhibitors to place a photo‐crosslinker and tag in the vicinity of p38 and its binding partners. Upon UV irradiation, proteins that are in close proximity to p38 are covalently crosslinked, and labeled proteins are detected and/or purified with an orthogonal chemical handle. Here we demonstrate that p38‐selective LTRs selectively label a diversity of p38 binding partners, including substrates, activators, and inactivators. Furthermore, these LTRs can be used in immunoprecipitations to provide low‐resolution structural information on p38‐containing complexes.     

Algorithms for planning and control of robot motions [TC Spotlight]

Robot motion planning and control is an essential component in creating autonomous systems that are able to execute high-level tasks for navigating and manipulating objects in challenging environments. Motion planning has led to active research over the past decades. Most of the research focused on the computational issue of generating feasible paths that lead the robot to a desired goal, while generally ignoring control concerns such as feedback, optimum, and uncertainty. The breakthrough achieved with sampling-based algorithms leads to effective techniques for hard, high-dimensional problems, and the recent improvements brought motion-planning algorithms closer to applicability in real problems. Nowadays, the practical interest of the state-of-the-art techniques is no longer restricted to robotics but extends to challenging problems arising in such diverse fields as graphics animation, virtual prototyping, and computational biology.     

Utilization and management practices of animal manure for replenishing soil fertility among smallscale crop farmers in semi-arid farming districts of the North West Province,South Africa

Poor soil fertility is one of the most limiting biophysical factors to agricultural production among smallscale farmers in much of the sub-Saharan Africa, especially the semi-arid areas. In this study, a survey of 200 randomly selected farming households across four districts (Mafikeng, Ditsobotla, Ganyesa and Taung) located in a semi-arid environment of the North West Province in South Africa was conducted to establish the utilisation and management of animal manure for managing soil fertility. The results showed that 66% of the farmers across the districts used animal manure on their crops. The types of manure used were in the order cattle > sheep = goat > chicken. Cattle manure was readily available from farmers’ own kraal or neighbours. Despite its availability and advantages, chicken manure was seldom used. The rates of manure application were generally low (mean 2.5 tha⁻¹) although most farmers (71%) applied it annually. In the majority of cases, manure would be applied to about half (57.5%) of the cropped land every year (average farm size was 5.3 hectares). The manure was mostly broadcasted (76%) on the surface before being ploughed under followed by dollop (53%). The quality of most of the manure resources was relatively poor as it had low N and P but high soil content (mean 22.7%). The study found that farmers have developed local knowledge with regards to criteria for defining manure quality. The criterion, which used physical characteristics such as colour, moisture content and presence of moulds in the manure, was quite consistent across the study districts and points to the possibility of the indigenous knowledge being interfaced with scientific knowledge. The factors which positively influenced farmers’ decision to use manure were herd sizes, farming experience, training and availability of manure, extension services and labour. On the other hand, farm sizes negatively affected manure use. It was observed that housing, feeding, storage and handling practices of manure resources was not optimum in most of the study districts and this contributed to loss of nutrients and quality. It is recommended that improved strategies of manure production and handling be adopted by farmers in order to maximise the quality and efficiency of manure utilization. The potential that exists in using chicken manure to supply crop nutrients needs to be explored.     

A Semi-Lagrangian Method for 3-D Fokker Planck Equations for Stochastic Dynamical Systems on the Sphere

In this paper, we consider stochastic dynamical systems on the sphere and the associated Fokker–Planck equations. A semi-Lagrangian method combined with a Finite Volume discretization of the sphere is presented to solve the Fokker–Planck equation. The method is applied to a typical problem in fiber dynamics and textile production. The numerical results are compared to explicit solutions and Monte-Carlo solutions.     

Optimization of the fabrication of novel stealth PLA-based nanoparticles by dispersion polymerization using D-optimal mixture design

Purpose: Nanoparticle size is important in drug delivery. Clearance of nanoparticles by cells of the reticuloendothelial system has been reported to increase with increase in particle size. Further, nanoparticles should be small enough to avoid lung or spleen filtering effects. Endocytosis and accumulation in tumor tissue by the enhanced permeability and retention effect are also processes that are influenced by particle size. We present the results of studies designed to optimize cross-linked biodegradable stealth polymeric nanoparticles fabricated by dispersion polymerization.

Methods: Nanoparticles were fabricated using different amounts of macromonomer, initiators, crosslinking agent and stabilizer in a dioxane/DMSO/water solvent system. Confirmation of nanoparticle formation was by scanning electron microscopy (SEM). Particle size was measured by dynamic light scattering (DLS). D-optimal mixture statistical experimental design was used for the experimental runs, followed by model generation (Scheffe polynomial) and optimization with the aid of a computer software. Model verification was done by comparing particle size data of some suggested solutions to the predicted particle sizes.

Results and conclusion: Data showed that average particle sizes follow the same trend as predicted by the model. Negative terms in the model corresponding to the cross-linking agent and stabilizer indicate the important factors for minimizing particle size.     

Gestures and multimodal input

For users with motion impairments, the standard keyboard and mouse arrangement for computer access often presents problems. Other approaches have to be adopted to overcome this. In this paper, we will describe the development of a prototype multimodal input system based on two gestural input channels. Results from extensive user trials of this system are presented. These trials showed that the physical and cognitive loads on the user can quickly become excessive and detrimental to the interaction. Designers of multimodal input systems need to be aware of this and perform regular user trials to minimize the problem.     

Integrated Modeling of Anaerobic Fluidized Bed Bioreactor for Deicing Waste Treatment. I: Model Derivation

An integrated mathematical model for propylene glycol (PG) degradation in an anaerobic fluidized bed bioreactor is described. Special attention is put on biomass distribution, bed expansion, and bed segregation, associated with the biofilm accumulation process. In order to interpret the segregation of the bed during the initial development of the biofilm, the model postulates various mixing intensities along the bed height and thereby different exchange rates of microbial cells between the biofilm and the bulk liquid. The model incorporates stoichiometry of PG methanization, hydrodynamics, and reaction kinetics for elucidating microscopic interaction among microbial trophic groups inside the biofilm as well as the macroscopic behavior of the reactor such as bed expansion. A biofilm diffusion mechanism is also taken into account focusing on the spatial distribution of multiple species of micro-organisms. Employing moving boundaries makes the model flexible in computation, which permits simplifying the implementation of the biofilm accumulation and the bed expansion phenomena.