Spatial Models to Account for Variation in Observer Effort in Bird Atlases

To assess the importance of variation in observer effort between and within bird atlas projects and demonstrate the use of relatively simple conditional autoregressive (CAR) models for analyzing grid-based atlas data with varying effort. Pennsylvania and West Virginia, United States of America. We used varying proportions of randomly selected training data to assess whether variations in observer effort can be accounted for using CAR models and whether such models would still be useful for atlases with incomplete data. We then evaluated whether the application of these models influenced our assessment of distribution change between two atlas projects separated by twenty years (Pennsylvania), and tested our modeling methodology on a state bird atlas with incomplete coverage (West Virginia). Conditional Autoregressive models which included observer effort and landscape covariates were able to make robust predictions of species distributions in cases of sparse data coverage. Further, we found that CAR models without landscape covariates performed favorably. These models also account for variation in observer effort between atlas projects and can have a profound effect on the overall assessment of distribution change. Accounting for variation in observer effort in atlas projects is critically important. CAR models provide a useful modeling framework for accounting for variation in observer effort in bird atlas data because they are relatively simple to apply, and quick to run

Influencing culture related risks to improve project success

Advances in technologies have resulted in significant interest, projects and investment in associated infrastructure to transform how public and private organisations engage and interact with their stakeholders. However, the success of such projects is far from certain. Projects continue to fail in higher numbers than they succeed across multiple industries, no matter the type of project management methodology adopted. Project success is often focused on time, cost and quality. However, there is growing recognition that the dynamic interaction of multiple actors from diverse networks influences project success. Current project management methodologies may not sufficiently reflect the complex and dynamic nature of projects. This paper explores how actions to influence culture can contribute to project success. We explore this concept through the lens of actor-network theory (ANT) which was used to guide the collection of data and the data analysis

Content Analysis of International STEM Education Research Journals

STEM education emerged as a focus for educators and researchers in the United States as more states and schools implement integrated, STEM-driven curricula and instruction in order to improve students’ STEM literacy, critical thinking skills, and 21st century workforce skills (Bybee, 2013). This study used content analysis (Grbich, 2013; Hsieh & Shannon, 2005) to investigate recent trends in STEM education research by analyzing all of the published articles in three international STEM education research journals. The criteria for journal selection were publication origination date, number of articles published, and ability to obtain the journals through student-accessible databases or journal websites. Data included the number and types of STEM subjects, whether or not the STEM subjects were integrated, the date of publication, and the setting and participants. Findings from this study suggest that STEM education research articles tend to focus on two or more STEM silos, with the number of iSTEM education research articles increasing in publication over time. Future research in STEM education should include K–12 settings to complement the work already being performed in higher education settings. ReferencesBybee, R. W. (2013). The case for STEM education: Challenges and opportunities. Arlington, VA: National Science Teachers Association.Grbich, C. (2013). Qualitative data analysis: An introduction. Los Angeles, CA: SAGE.Hsieh, H. F., & Shannon, S. E. (2005). Three approaches to qualitative content analysis. Qualitative Health Research, 15(9), 1277–1288. doi:10.1177/104973230527668

Gravity vs radiation model: on the importance of scale and heterogeneity in commuting flows

We test the recently introduced radiation model against the gravity model for the system composed of England and Wales, both for commuting patterns and for public transportation flows. The analysis is performed both at macroscopic scales, i.e. at the national scale, and at microscopic scales, i.e. at the city level. It is shown that the thermodynamic limit assumption for the original radiation model significantly underestimates the commuting flows for large cities. We then generalize the radiation model, introducing the correct normalisation factor for finite systems. We show that even if the gravity model has a better overall performance the parameter-free radiation model gives competitive results, especially for large scales.Comment: in press Phys. Rev. E, 201

A preliminary appraisal of the mineral potential of Venda based on a reconnaissance geochemical soil sampling survey and literature review

A reconnaissance soil sampling survey was carried out over Venda by Cycad (Pty) Ltd and the samples were analysed for 36 elements using XRF techniques, by Anglo American Research Laboratories in Johanuesburg. The data resulting from this survey forms the basis for the present interpretive study. Initially the sample positions were co-ordinated, then the geological, soil and sample types were allocated to each point. Twelve lithological groupings were chosen which incorporated most of the available data, retained significant geological characteristics and consisted of statistically significant sample populations. Statistical manipulation was undertaken for each of the lithological groups. Using a final population of 5768 samples, means were determined and anomalous values were identified using a threshold of mean plus two standard deviations. Due to time and budgetary constraints, 24 of the 36 elements were chosen for statisical manipulation and fourteen of these, with particular economic significance, were chosen for plotting, wherever significant numbers of anomalies were present. The element overlays were plotted so as to coincide with 18 of the 25, 1:50 000 topographic sheets covering Venda , the remaining 7 having inadequate sample coverage to yield meaningful contours. In this way a total of 175 element overlay sheets were plotted, each showing contoured element levels, with selected anomalous values. The treatment of the vast body of information made available by the Cycad sampling programme has thus been selective and has continually been aimed at highlighting and concentrating attention on the areas of greatest indicated mineralization potential, rather than on specific anomalies. In this regard it is felt that the present study has been successful, in spite of limited sample coverage in some areas. Combining the results of this study with a modern tectonically-based appraisal of mineralization potential and a knowledge of the local geology and previously known mineralization gleaned from an extensive literature review, the following types of mineralization are considered to have the highest potential in Venda: i) Nickel-copper-platinum mineralization as well as magnesite, in the olivine dolerite sills which intrude the base of the Karoo Sequence in Northern Venda. ii) Coal in the basal Karoo Sequence sediments in a broad zone from Jazz 715 MS in the west, and along the Klein Tshipise fault from Amonda 159 MT to the Mutale Copper Fields then east of these to the Kruger National Park. Where intrusives invade these lower Karoo sed iments the potential exists for amorphous graphite. iii) Hydrothermal copper and possibly gold and silver concentrations, in Nzhelele and Sibasa Formation rocks, particularly those associated with faults known to have been active in post-Soutpansberg times. iv) Sediment-hosted massive sulphide deposits (Cu-Pb -Zn) close to basin margin faults, near intersections with cross cutting faults that have resulted in localized basin formation. These are most likely in the Soutpansberg sediments. v) Martle, flake-graphite and late stage skarn mineralization (including lead, zinc, gold and tungsten), in calcareous rocks of the Gumbu Formation

The Cool and Deliberate Sense of the Community : \u3cem\u3eThe Federalist\u3c/em\u3e on Congress

The American civic canon holds that the Constitution creates three branches of government that are both separate and “equal.” Publius’s essays on Congress cast serious doubt on this supposition, at least with respect to the extent of each branch’s influence on the workings of the national regime. It is no mistake that both the Constitution and The Federalist treat Congress as the first branch of government. It is “justly regarded” as such, Louis Fisher says, primarily because of the appropriations power elucidated in Federalist 58. The Federalist understands Congress, George W. Carey writes, “to be the heart of the proposed system.” Even the doubts and concerns that Publius expresses about Congress reflect regard for its authority. Federalist 51, for example, acknowledges that the legislature “necessarily predominates” (Fed. 51, 350) in a republic, but it also seeks a remedy for the “inconveniency” this poses to the separation of powers. Institutionally, Congress has the power both to constitute and discipline the other branches, which have no comparable authority over it. Even when defending executive energy, Publius describes it as secondary to legislative deliberation. The centrality of the legislative branch is demonstrable not only institutionally but also theoretically, for it is here that Publius places his greatest hopes for solving one of his most fundamental problems: the reconciliation of a government with sufficient authority and energy on the one hand, with the preservation of both public and personal liberty, on the other – a concern that Hamilton and Madison respectively expressed in Federalist 1 and 37

How do the grain size characteristics of a tephra deposit change over time?

Financial support was provided by the National Science Foundation of America through grant 1202692 ‘Comparative Island Ecodynamics in the North Atlantic’ and grant 1249313 ‘Tephra layers and early warning signals for critical transitions’ (both to AJD).Volcanologists frequently use grain size distributions (GSDs) in tephra layers to infer eruption parameters. However, for long-past eruptions, the accuracy of the reconstruction depends upon the correspondence between the initial tephra deposit and preserved tephra layer on which inferences are based. We ask: how closely does the GSD of a decades-old tephra layer resemble the deposit from which it originated? We addressed this question with a study of the tephra layer produced by the eruption of Mount St Helens, USA, in May 1980. We compared grain size distributions from the fresh, undisturbed tephra with grain size measurements from the surviving tephra layer. We found that the overall grain size characteristics of the tephra layer were similar to the original deposit, and that distinctive features identified by earlier authors had been preserved. However, detailed analysis of our samples showed qualitative differences, specifically a loss of fine material (which we attributed to ‘winnowing’). Understanding how tephra deposits are transformed over time is critical to efforts to reconstruct past eruptions, but inherently difficult to study. We propose long-term, tephra application experiments as a potential way forward.Publisher PDFPeer reviewe