Extensible Prototyping for pragmatic engineering of knowledge-based systems

Knowledge-based systems (KBSs) have been built and practically applied in various contexts for decades. Yet, they still challenge developers by their complexity: Apart from a sound knowledge base they likewise require comprehensive user interface (UI) and interaction design for supporting the task at hand optimally. However, current KBS-Engineering methodologies still mostly focus on knowledge base development, regarding UI/interaction design a more incidental, low priority task. Thus, the UI often is developed in a rather ad hoc manner, thereby neglecting the potential of experimental design and creating reusable solutions. The integration of (rapid) evolutionary prototyping activities with KBS Engineering offers the chance for incorporating UI/interaction design more prominently into the process while at the same time leveraging the overall development task; specifically, we propose Extensible Prototyping as a tailored prototyping approach and we suggest its integration with the Agile Process Model for knowledge-based systems in this paper. For practical support, we further introduce the customized prototyping and knowledge systems engineering tool ProKEt, and we report on practical experiences with applying both the approach and the tool.     

Summoning earth and fire: The energy development implications of Grameen Shakti (GS) in Bangladesh

Since its establishment in 1996, the nonprofit company Grameen Shakti (GS) has installed almost half a million solar home systems (SHS), 132,000 cookstoves, and 13,300 biogas plants among 3.1 million beneficiaries. They plan to ramp up their expansion so that by 2015, more than 1.5 million SHS are in place along with 100,000 biogas units and 5 million improved cookstoves. This article describes GS’s current activities, the contours of its programs, and likely reasons for its success. It also explores the remaining challenges facing GS and distils common lessons for other energy development assistance projects and programs around the world. After detailing research methods consisting primarily of research interviews and site visits, the article briefly explores the history of GS and summarizes its three most prominent programs. The article then identifies six distinct benefits to their programs—expansion of energy access, less deforestation and fewer greenhouse gas emissions, price savings, direct employment and income generation, improved public health, and better technology—before discussing challenges related to staff retention and organizational growth, living standards, technical obstacles, affordability, tension with other energy programs, political constraints, and awareness and cultural values.     

Biodegradable polymers applied in tissue engineering research: a review

Typical applications and research areas of polymeric biomaterials include tissue replacement, tissue augmentation, tissue support, and drug delivery. In many cases the body needs only the temporary presence of a device/biomaterial, in which instance biodegradable and certain partially biodegradable polymeric materials are better alternatives than biostable ones. Recent treatment concepts based on scaffold‐based tissue engineering principles differ from standard tissue replacement and drug therapies as the engineered tissue aims not only to repair but also regenerate the target tissue. Cells have been cultured outside the body for many years; however, it has only recently become possible for scientists and engineers to grow complex three‐dimensional tissue grafts to meet clinical needs. New generations of scaffolds based on synthetic and natural polymers are being developed and evaluated at a rapid pace, aimed at mimicking the structural characteristics of natural extracellular matrix. This review focuses on scaffolds made of more recently developed synthetic polymers for tissue engineering applications. Currently, the design and fabrication of biodegradable synthetic scaffolds is driven by four material categories: (i) common clinically established polymers, including polyglycolide, polylactides, polycaprolactone; (ii) novel di‐ and tri‐block polymers; (iii) newly synthesized or studied polymeric biomaterials, such as polyorthoester, polyanhydrides, polyhydroxyalkanoate, polypyrroles, poly(ether ester amide)s, elastic shape‐memory polymers; and (iv) biomimetic materials, supramolecular polymers formed by self‐assembly, and matrices presenting distinctive or a variety of biochemical cues. This paper aims to review the latest developments from a scaffold material perspective, mainly pertaining to categories (ii) and (iii) listed above. Copyright © 2006 Society of Chemical Industry     

Practical application of the “turbid water” flag in ocean color imagery: Interference with sun-glint contaminated pixels in open ocean

A simple method to identify turbid, sediment-loaded, waters within satellite ocean color imageries was recently proposed (A. Morel and S. Bélanger, Remote Sensing of Environment, 102, (2006), 237-249). Systematic application of this method to the level-3 composites obtained from three ocean color sensors shows that the “turbid” flag is often raised in the open ocean, especially in the sub-tropical oligotrophic gyres, where turbidity is unlikely. In addition these flagged zones migrate with season, and clearly follow the sun declination course. The combination of low chlorophyll waters with a residual sun-glint is at the origin of this artifact. Simple approaches for eliminating such a misleading detection are proposed. The identification and elimination of the bias are also needed in particular for an unambiguous detection of the presence of calcite (coccolithophores) in open waters.     

A statnet Tutorial

The statnet suite of R packages contains a wide range of functionality for the statistical analysis of social networks, including the implementation of exponential-family random graph (ERG) models. In this paper we illustrate some of the functionality of statnet through a tutorial analysis of a friendship network of 1,461 adolescents.     

Determination of single mode condition in dielectric rib waveguide with large cross section by finite element analysis

The single mode condition in large cross section rib waveguides is of great interest because almost every kind of active and passive integrated optoelectronic device or sensor is designed to sustain only the fundamental mode of propagation for better matching with optical fibers. In this paper we present a criterion to determine the single mode condition for a large cross section rib waveguides, by comparison between the numerical solutions found with Neumann boundary conditions and Dirichlet boundaries conditions applied when solving the eigenvalues problem.     

Molecular Biomarkers in Idiopathic Pulmonary Fibrosis: State of the Art and Future Directions

Idiopathic pulmonary fibrosis (IPF), the most lethal form of interstitial pneumonia of unknown cause, is associated with a specific radiological and histopathological pattern (the so-called “usual interstitial pneumonia” pattern) and has a median survival estimated to be between 3 and 5 years after diagnosis. However, evidence shows that IPF has different clinical phenotypes, which are characterized by a variable disease course over time. At present, the natural history of IPF is unpredictable for individual patients, although some genetic factors and circulating biomarkers have been associated with different prognoses. Since in its early stages, IPF may be asymptomatic, leading to a delayed diagnosis. Two drugs, pirfenidone and nintedanib, have been shown to modify the disease course by slowing down the decline in lung function. It is also known that 5–10% of the IPF patients may be affected by episodes of acute and often fatal decline. The acute worsening of disease is sometimes attributed to identifiable conditions, such as pneumonia or heart failure; but many of these events occur without an identifiable cause. These idiopathic acute worsenings are termed acute exacerbations of IPF. To date, clinical biomarkers, diagnostic, prognostic, and theranostic, are not well characterized. However, they could become useful tools helping facilitate diagnoses, monitoring disease progression and treatment efficacy. The aim of this review is to cover molecular mechanisms underlying IPF and research into new clinical biomarkers, to be utilized in diagnosis and prognosis, even in patients treated with antifibrotic drugs.     

Temperature‐dependent coefficient of thermal expansion (CTE) of injection molded,short‐glass‐fiber‐reinforced polymers

A deep understanding of the anisotropic, composite‐, geometry‐, and temperature‐dependent coefficient of thermal expansion (CTE) of short‐fiber‐reinforced polymers is often needed in material development and at early stages of the design process of injection molded parts. Usually, the data available does not reflect the complex behavior and the knowledge about the influences and interactions are missing. This paper deals with a method for calculating the composite‐, geometry‐, and temperature‐dependent anisotropic CTE of parts made from short‐fiber reinforced polymers without respectively low preload to create an understanding of its origins and influential factors. Here, a good accordance between the measurements and calculations was achieved. POLYM. ENG. SCI., 55:2661–2668, 2015. © 2015 Society of Plastics Engineers     

Detailed Structure–Function Correlations of Bacillus subtilis Acetolactate Synthase

Isobutanol is deemed to be a next‐generation biofuel and a renewable platform chemical. 1 Non‐natural biosynthetic pathways for isobutanol production have been implemented in cell‐based and in vitro systems with Bacillus subtilis acetolactate synthase (AlsS) as key biocatalyst. 2 – 6 AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg²⁺ as cofactors. AlsS also catalyzes the conversion of 2‐ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol. Our phylogenetic analysis suggests that the ALS enzyme family forms a distinct subgroup of ThDP‐dependent enzymes. To unravel catalytically relevant structure‐function relationships, we solved the AlsS crystal structure at 2.3 Å in the presence of ThDP, Mg²⁺ and in a transition state with a 2‐lactyl moiety bound to ThDP. We supplemented our structural data by point mutations in the active site to identify catalytically important residues.