Introductory Graphics Programming: Transition to IMPACT

Computer programming is a difficult field for students to learn, while the most effective teaching strategies are not known conclusively. Educator’s opinions vary as to the optimal approach. It is largely a point of agreement however that programming, as an applied field, is learned more quickly as a function of practice. Traditional lecture approaches impose a passive mindset upon the student and uses valuable time. This study posits that students might be better served by minimizing student time passively listening to lectures and instead keeping students actively engaged at the keyboard work through programming problems individually and in small groups. The IMPACT model helps facilitate this move away from a purely instructor-led model to a more student-centered model. Both affective and performance metrics are gathered and analyzed in the transition to the new teaching model. As the first IMPACT class, run in a true IMPACT room, is currently in session, study results are pending

The Nature of Linkage Variation with Age in Inversion Heterozygotes of Drosophila melanogaster

Two kinds of variation in linkage values in Drosophila experiments are well known but poorly understood. One is the change in crossover values with increasing age of the female as shown by Bridges [1]; the other is excessive variation from female to female as pointed out by Gowen [2]. Studies reported in the present paper on an age effect in a special situation may contribute to the interpretation of both problems. They also serve as controls for the irradiation paper which follows [3]. The chief result of aging is a rapid decrease in recombination values during the first six days of egg-laying, particularly at or near the spindle attachment of the chromosome. After that period smaller changes consist, with variations, of a slight rise and second fall. In recognition of this Bridges [4] has defined as a condition for chromosome mapping the use of data from young females. From such data inferences are made as to the amount of actual crossing over which has occurred between genes which are assumed to be heterozygous at the time when the germ cells enter meiosis. That this procedure may overestimate the amount of crossing over has been elaborated by the senior author both by reasoning back from observable clustering of the data [5] and by deducing certain consequences of crossing over premeiotically, in gonial cells [6]. The present experiment shows an age effect and clustering attributable to oogonial crossing over in the same body of data, where meiotic crossovers have been greatly reduced or eliminated by inversions

Privacy, Anonymity, and Big Data in the Social Sciences

Quality social science research and the privacy of human subjects require trust

Introductory programming: a systematic literature review

As computing becomes a mainstream discipline embedded in the school curriculum and acts as an enabler for an increasing range of academic disciplines in higher education, the literature on introductory programming is growing. Although there have been several reviews that focus on specific aspects of introductory programming, there has been no broad overview of the literature exploring recent trends across the breadth of introductory programming. This paper is the report of an ITiCSE working group that conducted a systematic review in order to gain an overview of the introductory programming literature. Partitioning the literature into papers addressing the student, teaching, the curriculum, and assessment, we explore trends, highlight advances in knowledge over the past 15 years, and indicate possible directions for future research

Distinct respiratory responses of soils to complex organic substrate are governed predominantly by soil architecture and its microbial community

Factors governing the turnover of organic matter (OM) added to soils, including substrate quality, climate, environment and biology, are well known, but their relative importance has been difficult to ascertain due to the interconnected nature of the soil system. This has made their inclusion in mechanistic models of OM turnover or nutrient cycling difficult despite the potential power of these models to unravel complex interactions. Using high temporal-resolution respirometery (6 min measurement intervals), we monitored the respiratory response of 67 soils sampled from across England and Wales over a 5 day period following the addition of a complex organic substrate (green barley powder). Four respiratory response archetypes were observed, characterised by different rates of respiration as well as different time-dependent patterns. We also found that it was possible to predict, with 95% accuracy, which type of respiratory behaviour a soil would exhibit based on certain physical and chemical soil properties combined with the size and phenotypic structure of the microbial community. Bulk density, microbial biomass carbon, water holding capacity and microbial community phenotype were identified as the four most important factors in predicting the soils’ respiratory responses using a Bayesian belief network. These results show that the size and constitution of the microbial community are as important as physico-chemical properties of a soil in governing the respiratory response to OM addition. Such a combination suggests that the 'architecture' of the soil, i.e. the integration of the spatial organisation of the environment and the interactions between the communities living and functioning within the pore networks, is fundamentally important in regulating such processes

Techniques and crops for efficient rooftop gardens in Bologna, Italy

Urban rooftop farming favours local food production. Although rooftop farming is perceived as 33 a sustainable system, there is a lack of quantitative studies on rooftop farming. There we set up 34 experiments in the community rooftop garden of a public housing building in Bologna, Italy, 35 between 2012 and 2014. We grew lettuce, a leafy vegetable, using three techniques: nutrient 36 film, floating hydroponic and soil cultivation. We also grew tomato, chilli pepper, eggplant, 37 melon, watermelon on soils. Data was analysed by life cycle assessment for environmental and 38 economic performance. Results reveal that the best techniques of lettuce cultivation to address 39 global warming were floating in the summer, with 65-85% less environmental impact per kg 40 than nutrient film; and soil production in the winter, with 85-95% less environmental impact. 41 Furthermore, floating production was 25% cheaper in summer and soil was 65% cheaper in 42 winter, compared to the nutrient film technique. For soil production, eggplants and tomatoes 43 showed the best environmental performances of about 74 g CO2 per kg. Eggplant production in 44 soil gave in the cheapest crop of 0.13 € per kg