All PBL Starts Here: The Problem

One essential piece of implementing of PBL is the problem. There have been calls from practitioners in the PBL field for a systematic process for designing effective PBL problems. Yet, the research efforts to explore, develop, and test PBL problem design methods or processes are still sparse. From an instructional designer and researcher’s perspective, I deem problem design to be the first step to ensure not only the proper affordance of the learning goal but also the students’ overall learning process in PBL implementation. PBL problem design is the area I have studied most consistently and passionately. In this paper, I share my continuing study of PBL problem design, from the original 3C3R model and the 9-step design process, to an examination of the cognitive components of PBL problems such as problem difficulty structure and levels, to my recent focus on the affective components of PBL problems

A Taxonomy and Framework for Designing Educational Games to Promote Problem Solving

Problem solving is often discussed as one of the benefits of games and game-based learning, yet little empirical research exists to support this assertion. It will be critical to establish and validate models of problem solving in games, but this will be difficult if not impossible without a better understanding of problem solving than currently exists in the field of serious games. Problem solving and problem-based learning (PBL) have been studied intensely in both Europe and the United States for more than 75 years. Any models and research on the relation of games and problem solving must build on the existing research base in problem solving and PBL rather than unwittingly covering old ground in these areas. In this paper, we present an overview of the dimensions upon which different problems vary as well as their associated learning outcomes. We also propose a classification of gameplay (as opposed to game genre) that accounts for the cognitive skills encountered during gameplay, relying in part on previous classification systems, Mark Wolf\u27s concept of grids of interactivity (which we call iGrids), and our own cognitive analysis of gameplay. We then briefly describe eleven different types of problems, the ways in which they differ, and the gameplay types most likely to support them using our gameplay topology. We believe that this approach can guide the design of games intended to promote problem solving and that it points the way toward future research in problem solving and games

Aligning Problem Solving and Gameplay : A Model for Future Research and Design

Problem solving is often discussed as one of the benefits of games and game-based learning (e.g., Gee, 2007a, Van Eck 2006a), yet little empirical research exists to support this assertion. It will be critical to establish and validate models of problem solving in games (Van Eck, 2007), but this will be difficult if not impossible without a better understanding of problem solving than currently exists in the field of serious games. While games can be used to teach a variety of content across multiple domains (Van Eck, 2006b, 2008), the ability of games to promote problem solving may be more important to the field of serious games because problem solving skills cross all domains and are among the most difficult learning outcomes to achieve. This may be particularly important in science, technology, engineering, and math (STEM), which is why serious game researchers are building games to promote problem solving in science (e.g., Gaydos & Squire, this volume; Van Eck, Hung, Bowman, & Love, 2009). This is perhaps why serious game researchers are building games to promote problem solving in science Current research and design theory in serious games are insufficient to explain the relationship between problem solving and games, nor do they support the design of educational games intended to promote problem solving. Problem solving and problem-based learning (PBL) have been studied intensely in both Europe and the United States for more than 75 years, and while the focus of that study and conceptualization of problem solving have evolved during that time, there is a tremendous body of knowledge to draw from. Most recently, researchers (e.g., Jonassen, 1997, 2000, & 2002; Hung, 2006a; Jonassen & Hung, 2008) have made advances in both the delineation and definition of problem types and models for designing effective problems and PBL. Any models and research on the relation of games and problem solving must build on the existing research base in problem solving and PBL rather than unwittingly covering old ground in these areas. In this chapter, the authors present an overview of the dimensions upon which different problems vary, including domain knowledge, structuredness, and their associated learning outcomes. We then propose a classification of gameplay (as opposed to game genre) that accounts for the cognitive skills encountered during gameplay, relying in part on previous classifications systems (e.g., Apperley, 2006), Mark Wolf’s (2006) concept of grids of interactivity (which we call iGrids), and our own cognitive analysis of gameplay. We then use this classification system, the iGrids, and example games to describe eleven different types of problems, the ways in which they differ, and the gameplay types most likely to support them. We conclude with a description of the ability of problems and games themselves to address specific learning outcomes independent of problem solving, including domain-specific learning, higher-order thinking, psychomotor skills, and attitude change. Implications for future research are also described. We believe that this approach can guide the design of games intended to promote problem solving and points the way toward future research in problem solving and games

1-Benzoyl-3-[4-(3-benzoyl­thio­ureido)phen­yl]thio­urea

The mol­ecule of the title compound, C22H18N4O2S2, lies across a crystallographic inversion centre. The mol­ecule adopts a syn–anti configuration with respect to the positions of the carbonyl groups and terminal phenyl rings relative to the thione S atom across the C—N bond. There are two intra­molecular N—H⋯O and C—H⋯S hydrogen bonds within each molecule, resulting in the formation of four six-membered S(6) rings. The central and terminal rings make a dihedral angle of 13.55 (15)°. In the crystal, mol­ecules are linked by inter­molecular C—H⋯S hydrogen bonds, forming R 2 2(14) rings and resulting in zigzag chains

3,3′′,4,4′′-Tetra­meth­oxy-1,1′:4′,1′′-terphen­yl

The title mol­ecule, C22H22O4, is centrosymmetric with an inversion centre located at the centre of the benzene ring. The 3,4-dimeth­oxy­benzene fragment is essentially planar [maximum deviation = 0.400 (2) Å] and twisted relative to the central benzene ring, forming a dihedral angle of 21.25 (7)°. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules into a two-dimensional polymeric structure lying parallel to (100)

1,2-Bis(N′-benzoyl­thio­ureido)-4-chloro­benzene

In the title compound, C22H17ClN4O2S2, both benzoyl groups are trans to the thiono group across their C—N bonds. The two methyl­ene carbamothioyl formamide fragments of the benzoyl­thio­urea side arms make a dihedral angle of 87.00 (10)°. The mol­ecule is stabilized by intra­molecular N—H⋯O, N—H⋯S and C—H⋯·S hydrogen bonds. In the crystal, mol­ecules are linked by N—H⋯O and N—H⋯S inter­molecular hydrogen bonds into zigzag chains along the a axis

Factors Related to Significant Improvement of Estimated Glomerular Filtration Rates in Chronic Hepatitis B Patients Receiving Telbivudine Therapy

Background and Aim. The improvement of estimated glomerular filtration rates (eGFRs) in chronic hepatitis B (CHB) patients receiving telbivudine therapy is well known. The aim of this study was to clarify the kinetics of eGFRs and to identify the significant factors related to the improvement of eGFRs in telbivudine-treated CHB patients in a real-world setting. Methods. Serial eGFRs were calculated every 3 months using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The patients were classified as CKD-1, -2, or -3 according to a baseline eGFR of ≥90, 60–89, or <60 mL/min/1.73 m2, respectively. A significant improvement of eGFR was defined as a more than 10% increase from the baseline. Results. A total of 129 patients were enrolled, of whom 36% had significantly improved eGFRs. According to a multivariate analysis, diabetes mellitus (DM) (p=0.028) and CKD-3 (p=0.043) were both significantly related to such improvement. The rates of significant improvement of eGFR were about 73% and 77% in patients with DM and CKD-3, respectively. Conclusions. Telbivudine is an alternative drug of choice for the treatment of hepatitis B patients for whom renal safety is a concern, especially patients with DM and CKD-3

Granulocyte Colony-Stimulating Factor Activating HIF-1α Acts Synergistically with Erythropoietin to Promote Tissue Plasticity

Stroke and peripheral limb ischemia are serious clinical problems with poor prognosis and limited treatment. The cytokines erythropoietin (EPO) and granulocyte-colony stimulating factor (G-CSF) have been used to induce endogenous cell repair and angiogenesis. Here, we demonstrated that the combination therapy of EPO and G-CSF exerted synergistic effects on cell survival and functional recovery from cerebral and peripheral limbs ischemia. We observed that even under normoxic conditions, G-CSF activates hypoxia-inducible factor-1α (HIF-1α), which then binds to the EPO promoter and enhances EPO expression. Serum EPO level was significantly increased by G-CSF injection, with the exception of Tg-HIF-1α+f/+f mice. The neuroplastic mechanisms exerted by EPO combined with G-CSF included enhanced expression of the antiapoptotic protein of Bcl-2, augmented neurotrophic factors synthesis, and promoted neovascularization. Further, the combination therapy significantly increased homing and differentiation of bone marrow stem cells (BMSCs) and intrinsic neural progenitor cells (INPCs) into the ischemic area. In summary, EPO in combination with G-CSF synergistically enhanced angiogenesis and tissue plasticity in ischemic animal models, leading to greater functional recovery than either agent alone

Void Structures in Regularly Patterned ZnO Nanorods Grown with the Hydrothermal Method

The void structures and related optical properties after thermal annealing with ambient oxygen in regularly patterned ZnO nanrorod (NR) arrays grown with the hydrothermal method are studied. In increasing the thermal annealing temperature, void distribution starts from the bottom and extends to the top of an NR in the vertical (c-axis) growth region. When the annealing temperature is higher than 400°C, void distribution spreads into the lateral (m-axis) growth region. Photoluminescence measurement shows that the ZnO band-edge emission, in contrast to defect emission in the yellow-red range, is the strongest under the n-ZnO NR process conditions of 0.003 M in Ga-doping concentration and 300°C in thermal annealing temperature with ambient oxygen. Energy dispersive X-ray spectroscopy data indicate that the concentration of hydroxyl groups in the vertical growth region is significantly higher than that in the lateral growth region. During thermal annealing, hydroxyl groups are desorbed from the NR leaving anion vacancies for reacting with cation vacancies to form voids