Pass/Fail Grading and Educational Practices in Computer Science

Binary (pass/fail) grading have been shown to have benefits with respect to mental health and collaboration, and is argued to promote a deep approach to learning. However, diverging results with respect to academic achievement suggests that the full benefits of binary grading are contingent on underlying factors, such as how the teaching and learning activities in the course are designed. We here present experiences and student feedback for an intermediate level course in computer science that is graded using pass/fail, and which is highly successful both in terms of of student enjoyment and academic achievement. Survey results also indicate that students apply a deeper learning approach towards the course than average. Drawing on examples and findings from this course, we argue that the following three practices makes a binary graded course in computer science successful: a) a sufficiently high bar for passing, b) clear course requirements, and c) the use of formative assessment

Time-inconsistent Planning: Simple Motivation Is Hard to Find

With the introduction of the graph-theoretic time-inconsistent planning model due to Kleinberg and Oren, it has been possible to investigate the computational complexity of how a task designer best can support a present-biased agent in completing the task. In this paper, we study the complexity of finding a choice reduction for the agent; that is, how to remove edges and vertices from the task graph such that a present-biased agent will remain motivated to reach his target even for a limited reward. While this problem is NP-complete in general, this is not necessarily true for instances which occur in practice, or for solutions which are of interest to task designers. For instance, a task designer may desire to find the best task graph which is not too complicated. We therefore investigate the problem of finding simple motivating subgraphs. These are structures where the agent will modify his plan at most $k$ times along the way. We quantify this simplicity in the time-inconsistency model as a structural parameter: The number of branching vertices (vertices with out-degree at least $2$) in a minimal motivating subgraph. Our results are as follows: We give a linear algorithm for finding an optimal motivating path, i.e. when $k=0$. On the negative side, we show that finding a simple motivating subgraph is NP-complete even if we allow only a single branching vertex --- revealing that simple motivating subgraphs are indeed hard to find. However, we give a pseudo-polynomial algorithm for the case when $k$ is fixed and edge weights are rationals, which might be a reasonable assumption in practice.Comment: An extended abstract of this paper is accepted at AAAI 202

Subgraph Complementation

A subgraph complement of the graph G is a graph obtained from G by complementing all the edges in one of its induced subgraphs. We study the following algorithmic question: for a given graph G and graph class G, is there a subgraph complement of G which is in G? We show that this problem can be solved in polynomial time for various choices of the graphs class G, such as bipartite, d-degenerate, or cographs. We complement these results by proving that the problem is NP-complete when G is the class of regular graphs.publishedVersio

Introduksjonsdag for gruppeledere i informatikk: hvilke tema bør adresseres?

Poster submissio

Cytotoxicity, in Vivo Skin Irritation and Acute Systemic Toxicity of the Mesoporous Magnesium Carbonate Upsalite ®

Abstract Upsalite ® is a mesoporous magnesium carbonate synthesized without using surfactants and therefore highly attractive from environmental and production economy points of view. The material has recently been suggested as drug delivery vehicle and as topical bacteriostatic agent. In order to continue exploring these and other bio-related applications of the material, primary biocompatibility studies are needed. Herein we present the first in vivo acute systemic toxicity and skin irritation analyses as well as in vitro cytotoxicity evaluations of Upsalite ® . The material was found to be non-toxic for human dermal fibroblasts cells up to a concentration of 1000 µg/ml and 48 h exposure in contrast to the mesoporous silica material SBA-15, used as reference, which significantly affected cell viability at particle concentration of 500 and 1000 µg/ml after the same exposure time. Topical application of Upsalite ® resulted in negligible cutaneous reactions in a rabbit skin irritation model and no evidence of significant systemic toxicity was found when saline extracts of Upsalite ® were injected in mice. Injection of sesame oil extract, however, resulted in transient weight loss, most likely due to injection of particles, and not toxic leachables. The presented results form the basis for future development of Upsalite ® and similar mesoporous materials in biomedical applications and further toxicity as well as biocompatibility studies should be directed towards specific areas of use

A summary to communicate evidence from systematic reviews to the public improved understanding and accessibility of information: a randomized controlled trial.

AbstractObjectivesTo evaluate a new format of a summary, which presents research from synthesized evidence to patients and the public.Study Design and SettingWe conducted a randomized controlled trial in 143 members of the public from five countries (Canada, Norway, Spain, Argentina, and Italy). Participants received either a new summary format (a plain language summary [PLS]) or the current format used in Cochrane systematic reviews. The new PLS presents information about the condition and intervention, a narrative summary of results, and a table of results with absolute numbers for effects of the intervention and quality of the evidence using Grading of Recommendations Assessment, Development, and Evaluation.ResultsWith the new PLS, more participants understood the benefits and harms and quality of evidence (53% vs. 18%, P < 0.001); more answered each of the five questions correctly (P ≤ 0.001 for four questions); and they answered more questions correctly, median 3 (interquartile range [IQR]: 1–4) vs. 1 (IQR: 0–1), P < 0.001). Better understanding was independent of education level. More participants found information in the new PLS reliable, easy to find, easy to understand, and presented in a way that helped make decisions. Overall, participants preferred the new PLS.ConclusionThis new PLS format for patients and the public is a promising tool to translate evidence from synthesized research

Ultrafast All-Polymer Paper-Based Batteries

Conducting polymers for battery applications have been subject to numerous investigations during the last two decades. However, the functional charging rates and the cycling stabilities have so far been found to be insufficient for practical applications. These shortcomings can, at least partially, be explained by the fact that thick layers of the conducting polymers have been used to obtain sufficient capacities of the batteries. In the present letter, we introduce a novel nanostructured high-surface area electrode material for energy storage applications composed of cellulose fibers of algal origin individually coated with a 50 nm thin layer of polypyrrole. Our results show the hitherto highest reported charge capacities and charging rates for an all polymer paper-based battery. The composite conductive paper material is shown to have a specific surface area of 80 m2 g-1 and batteries based on this material can be charged with currents as high as 600 mA cm-2 with only 6 % loss in capacity over 100 subsequent charge and discharge cycles. The aqueous-based batteries, which are entirely based on cellulose and polypyrrole and exhibit charge capacities between 25 and 33 mAh g-1 or 38-50 mAh g-1 per weight of the active material, open up new possibilities for the production of environmentally friendly, cost efficient, up-scalable and lightweight energy storage systems. There is currently a great interest in the development of thin, flexible, lightweight, and environmentally friendly batteries and supercapacitors.1 In this process, the preparation of novel redox polymer and electronically conducting polymer-base