Effectiveness of Ninth-Grade Physics in Maine: Conceptual Understanding

The Physics First movement - teaching a true physics course to ninth grade students - is gaining popularity in high schools. There are several different rhetorical arguments for and against this movement, and it is quite controversial in physics education. However, there is no actual evidence to assess the success, or failure, of this substantial shift in the science teaching sequence. We have undertaken a comparison study of physics classes taught in ninth- and 12th grade classes in Maine. Comparisons of student understanding and gains with respect to mechanics concepts were made with excerpts from well-known multiple-choice surveys and individual student interviews. Results indicate that both populations begin physics courses with similar content knowledge and specific difficulties, but that in the learning of the concepts ninth graders are more sensitive to the instructional method used.Comment: 15 pages, 2 tables, 0 figures, to be published in The Physics Teache

On the genus Anchonus Schönherr in Florida (Coleoptera: Curculionidae)

Four species of Anchonus Schonherr occur in Florida: A. flol'idanus Schwarz, A. dul'yi Blatchley, A. blatchleyi Sleeper, and A. suillus (Fabricius), which is recorded from Florida and the continental United States for the first time. The species are distinguished in a key and illustrated. A lectotype is selected for A. floridanus

Locally Estimating Core Numbers

Graphs are a powerful way to model interactions and relationships in data from a wide variety of application domains. In this setting, entities represented by vertices at the "center" of the graph are often more important than those associated with vertices on the "fringes". For example, central nodes tend to be more critical in the spread of information or disease and play an important role in clustering/community formation. Identifying such "core" vertices has recently received additional attention in the context of {\em network experiments}, which analyze the response when a random subset of vertices are exposed to a treatment (e.g. inoculation, free product samples, etc). Specifically, the likelihood of having many central vertices in any exposure subset can have a significant impact on the experiment. We focus on using $k$-cores and core numbers to measure the extent to which a vertex is central in a graph. Existing algorithms for computing the core number of a vertex require the entire graph as input, an unrealistic scenario in many real world applications. Moreover, in the context of network experiments, the subgraph induced by the treated vertices is only known in a probabilistic sense. We introduce a new method for estimating the core number based only on the properties of the graph within a region of radius $\delta$ around the vertex, and prove an asymptotic error bound of our estimator on random graphs. Further, we empirically validate the accuracy of our estimator for small values of $\delta$ on a representative corpus of real data sets. Finally, we evaluate the impact of improved local estimation on an open problem in network experimentation posed by Ugander et al.Comment: Main paper body is identical to previous version (ICDM version). Appendix with additional data sets and enlarged figures has been added to the en

Effect of Genotype and Environment on the Glycoalkaloid Content of Rare, Heritage, and Commercial Potato Varieties

peer-reviewedPotatoes accumulate toxic steroidal compounds that could be harmful for humans if consumed in high quantities and must be controlled. In this study, we were interested in assessing the levels and variation of glycoalkaloid content in 60 varieties of potato planted in 2 trial sites over 2 y. Total glycoalkaloid levels ranged from 4 to 957 mg/kg of dry weight in the flesh and from 150 to 8133 mg/kg in the skin, with the latter accumulating generally more α-chaconine than α-solanine. Contents in the flesh were below the safe limit for all varieties, but were generally above in the skin. Maximum values in each site and year of cultivation were found for varieties “Beauty of Hebron,” “May Queen,” and “Arran Pilot” in the skin and “Beauty of Hebron,” “International Kidney,” and “Congo” in the flesh. Year of cultivation had a significant effect on total glycoalkaloid content (P < 0.0001), with interactions between variety and site of cultivation and variety and year of cultivation also significant (P < 0.0001), implying that environmental effects seem to act differentially and could induce high levels in genetically predisposed varieties.Teagasc Walsh Fellowship Programm

Reforming welfare: a look backwards

In its final report the Welfare Working Group (WWG) asserts that ‘Our welfare system has major deficiencies that need to be corrected if we are to achieve the outcomes New Zealanders expect from the welfare system. Addressing these issues requires innovation and fundamental change to the welfare system, rather than further piecemeal change’ (WWG, 2011, p.i). The report fails to meet all these aims because of: (1) its imprecision and lack of clarity about key terminology; (2) the agenda which it set, including the terms of reference under which it worked; and (3) the assumptions it made about the purpose and role of income support systems and the values on which those systems should be based

The Idea of the American South, 1920-1941

Originally published in 1979. The idea of the "South" has its roots in Romanticism and American culture of the nineteenth century. This study by Michael O'Brien analyzes how the idea of a unique Southern consciousness endured into the twentieth century and how it affected the lives of prominent white Southern intellectuals. Individual chapters treat Howard Odum, John Donald Wade, John Crowe Ransom, Allen Tate, Frank Owsley, and Donald Davidson. The chapters trace each man's growing need for the idea of the South—how each defined it and how far each was able to sustain the idea as an element of social analysis. The Idea of the American South moves the debate over Southern identity from speculative essays about the "central theme" of Southern history and, by implication, past the restricted perception that race relations are a sufficient key to understanding the history of Southern identity

Information Seeking & Documentation as Communication: A Software Engineering Perspective

Effective communication of knowledge is paramount in every software organisation. Essentially, the role of documentation in a software engineering context is to communicate information and knowledge of the system it describes. Unfortunately, the current perception of documentation is that it is outdated, irrelevant and incomplete. Several studies to date have revealed that documentation is unfortunately often far from ideal. Problems tend to be diverse, ranging from incompleteness, to lack of clarity, to inaccuracy, obsolescence, difficulty of access, and lack of availability in local languages. This paper begins with a discussion of information seeking as an appropriate perspective for studying software maintenance activities. To this end, it examines the importance and centrality of documentation in this process. It finally concludes with a discussion on how software documentation practices can be improved to ensure software engineers communicate more effectively via the wide variety of documents that their projects require