Learning to communicate computationally with Flip: a bi-modal programming language for game creation

Teaching basic computational concepts and skills to school children is currently a curricular focus in many countries. Running parallel to this trend are advances in programming environments and teaching methods which aim to make computer science more accessible, and more motivating. In this paper, we describe the design and evaluation of Flip, a programming language that aims to help 11–15 year olds develop computational skills through creating their own 3D role-playing games. Flip has two main components: 1) a visual language (based on an interlocking blocks design common to many current visual languages), and 2) a dynamically updating natural language version of the script under creation. This programming-language/natural-language pairing is a unique feature of Flip, designed to allow learners to draw upon their familiarity with natural language to “decode the code”. Flip aims to support young people in developing an understanding of computational concepts as well as the skills to use and communicate these concepts effectively. This paper investigates the extent to which Flip can be used by young people to create working scripts, and examines improvements in their expression of computational rules and concepts after using the tool. We provide an overview of the design and implementation of Flip before describing an evaluation study carried out with 12–13 year olds in a naturalistic setting. Over the course of 8 weeks, the majority of students were able to use Flip to write small programs to bring about interactive behaviours in the games they created. Furthermore, there was a significant improvement in their computational communication after using Flip (as measured by a pre/post-test). An additional finding was that girls wrote more, and more complex, scripts than did boys, and there was a trend for girls to show greater learning gains relative to the boys

Antidepressant Controlled Trial For Negative Symptoms In Schizophrenia (ACTIONS): a double-blind, placebo-controlled, randomised clinical trial

Background Negative symptoms of schizophrenia represent deficiencies in emotional responsiveness, motivation, socialisation, speech and movement. When persistent, they are held to account for much of the poor functional outcomes associated with schizophrenia. There are currently no approved pharmacological treatments. While the available evidence suggests that a combination of antipsychotic and antidepressant medication may be effective in treating negative symptoms, it is too limited to allow any firm conclusions. Objective To establish the clinical effectiveness and cost-effectiveness of augmentation of antipsychotic medication with the antidepressant citalopram for the management of negative symptoms in schizophrenia. Design A multicentre, double-blind, individually randomised, placebo-controlled trial with 12-month follow-up Setting Adult psychiatric services, treating people with schizophrenia. Participants Inpatients or outpatients with schizophrenia, on continuing, stable antipsychotic medication, with persistent negative symptoms at a criterion level of severity. Interventions Eligible participants were randomised 1 : 1 to treatment with either placebo (one capsule) or 20 mg of citalopram per day for 48 weeks, with the clinical option at 4 weeks to increase the daily dosage to 40 mg of citalopram or two placebo capsules for the remainder of the study. Main Outcome Measures The primary outcomes were quality of life measured at 12 and 48 weeks assessed using the Heinrich’s Quality of Life Scale, and negative symptoms at 12 weeks measured on the negative symptom subscale of the Positive and Negative Syndrome Scale. Results No therapeutic benefit in terms of improvement in quality of life or negative symptoms was detected for citalopram over 12 weeks or at 48 weeks, but secondary analysis suggested modest improvement in the negative symptom domain, avolition/amotivation, at 12 weeks (mean difference –1.3, 95% confidence interval–2.5 to–0.09). There were no statistically significant differences between the two treatment arms over 48-week follow-up in either the health economics outcomes or costs, and no differences in the frequency or severity of adverse effects, including corrected QT interval prolongation. Limitations The trial under-recruited, partly because cardiac safety concerns about citalopram were raised, with the 62 participants recruited falling well short of the target recruitment of 358. Although this was the largest sample randomised to citalopram in a randomised controlled trial of antidepressant augmentation for negative symptoms of schizophrenia and had the longest follow-up, the power of statistical analysis to detect significant differences between the active and placebo groups was limited. Conclusion Although adjunctive citalopram did not improve negative symptoms overall, there was evidence of some positive effect on avolition/amotivation, recognised as a critical barrier to psychosocial rehabilitation and achieving better social and community functional outcomes. Comprehensive assessment of side-effect burden did not identify any serious safety or tolerability issues. The addition of citalopram as a long-term prescribing strategy for the treatment of negative symptoms may merit further investigation in larger studies. Future Work Further studies of the viability of adjunctive antidepressant treatment for negative symptoms in schizophrenia should include appropriate safety monitoring and use rating scales that allow for evaluation of avolition/amotivation as a discrete negative symptom domain. Overcoming the barriers to recruiting an adequate sample size will remain a challenge.</p

Characterization of the Single Stranded DNA Binding Protein SsbB Encoded in the Gonoccocal Genetic Island

Background: Most strains of Neisseria gonorrhoeae carry a Gonococcal Genetic Island which encodes a type IV secretion system involved in the secretion of ssDNA. We characterize the GGI-encoded ssDNA binding protein, SsbB. Close homologs of SsbB are located within a conserved genetic cluster found in genetic islands of different proteobacteria. This cluster encodes DNA-processing enzymes such as the ParA and ParB partitioning proteins, the TopB topoisomerase, and four conserved hypothetical proteins. The SsbB homologs found in these clusters form a family separated from other ssDNA binding proteins. Methodology/Principal Findings: In contrast to most other SSBs, SsbB did not complement the Escherichia coli ssb deletion mutant. Purified SsbB forms a stable tetramer. Electrophoretic mobility shift assays and fluorescence titration assays, as well as atomic force microscopy demonstrate that SsbB binds ssDNA specifically with high affinity. SsbB binds single-stranded DNA with minimal binding frames for one or two SsbB tetramers of 15 and 70 nucleotides. The binding mode was independent of increasing Mg 2+ or NaCl concentrations. No role of SsbB in ssDNA secretion or DNA uptake could be identified, but SsbB strongly stimulated Topoisomerase I activity

Strategies for Controlled Placement of Nanoscale Building Blocks

The capability of placing individual nanoscale building blocks on exact substrate locations in a controlled manner is one of the key requirements to realize future electronic, optical, and magnetic devices and sensors that are composed of such blocks. This article reviews some important advances in the strategies for controlled placement of nanoscale building blocks. In particular, we will overview template assisted placement that utilizes physical, molecular, or electrostatic templates, DNA-programmed assembly, placement using dielectrophoresis, approaches for non-close-packed assembly of spherical particles, and recent development of focused placement schemes including electrostatic funneling, focused placement via molecular gradient patterns, electrodynamic focusing of charged aerosols, and others

Initial sequencing and analysis of the human genome

The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62798/1/409860a0.pd