Lost in hyperspace: Linearity versus exploration in the design of multimedia for independent learners

We are developing multimedia tutorials for independent learners based on a generic software shell. In doing so, one of the pedagogic issues we are addressing relates to navigation. This is a key factor in the effectiveness of multimedia teaching, since it affects how easy students find it to extract and integrate information. Multimedia tutorials tend to be either highly structured, with materials presented in a relatively linear fashion, or an encyclopedia-style explorative resource. The former is restrictive and provides the student with little freedom to study the materials in the order they choose; the latter makes systematic study difficult and students can easily become ‘lost’. Disorientation in explorative-style packages is a particular problem for Field Dependent people (Witkin et al., 1971). We have incorporated the best features of both linear and explorative packages in our shell and our tutorials, with the aim of supporting Field Dependent people as much as possible, while not denying those students who prefer to work in an explorative way the freedom to do so

Seasonal Occurrence of Pine Root Collar Weevil, \u3ci\u3eHylobius Radicis\u3c/i\u3e (Coleoptera: Curculionidae), in Red Pine Stands Undergoing Decline

A trapping scheme was devised for sampling the pine root collar weevil, Hylobius radicis, in mature red pine plantations in Wisconsin. Adult weevils were trapped throughout the 1986 field season, and the method appears sensitive enough to discern temporal and spatial trends. The number of weevils caught was higher in stands symptomatic of the general condition currently labelled Red Pine Decline and Mortality. In some stands there was a strong tendency for trap catches to be particularly high near certain trees. Seasonal trends and sex ratios were compared with published reports of H. radicis activity in Michigan

Within-Generation Morality of the Jack Pine Tip Beetle, \u3ci\u3eConophthorus Banksianae\u3c/i\u3e McPherson, in Michigan

(excerpt) The jack pine tip beetle (Conophthorus banksianae McPherson) is a shoot-infesting scolytid hat primarily attacks jack pine (Pinus banksiana Lamb.) in Michigan. The insect was previously thought to be a variant of C. resinosae Hopkins, which attacks cones and shoot tips of red pine. McPherson described C. banksianae as a new species, following life cycle and behavioral studies (McPherson, Wilson, and Stehr 1970; McPherson, Stehr, and Wilson 1970). Separating them by morphological features has been unsuccessful (Herdy 1963)

Seesaw Spectroscopy at Colliders

A low-scale neutrino seesaw may be probed or even reconstructed at colliders provided that supersymmetry is at the weak scale and the LSP is a sterile sneutrino. Because the neutrino Yukawa couplings are small, the NLSP is typically long-lived and thus a significant fraction of colored or charged NLSPs may stop in the detector material before decaying to the LSP and a charged lepton, gauge boson, or Higgs. For two-body NLSP decays, the energy spectrum of the visible decay product exhibits a monochromatic line for each sterile sneutrino which can be used to extract the sterile sneutrino masses and some or all entries of the neutrino Yukawa matrix modulo phases. Similar methods can be used to extract these parameters from the Dalitz plot in the case of three-body NLSP decays. Assuming that the sterile sneutrino and neutrino are roughly degenerate, one can confirm the existence of a neutrino seesaw by comparing these measured parameters to the observed active neutrino masses and mixing angles. Seesaw spectroscopy can also provide genuinely new information such as the value of $\theta_{13}$, the nature of the neutrino mass hierarchy, and the presence of CP conservation in the neutrino sector. We introduce a weak-scale theory of leptogenesis that can be directly tested by these techniques.Comment: 7 pages, 4 figure

Acoustic Mode Measurements in the Inlet of a Model Turbofan Using a Continuously Rotating Rake

Comprehensive measurements of the spinning acoustic mode structure in the inlet of the Advanced Ducted Propeller (ADP) have been completed. These measurements were taken using a unique and previously untried method which was first proposed by T.G. Sofrin. A continuously rotating microphone system was employed. The ADP model was designed and built by Pratt & Whitney and tested in the NASA Lewis 9- by 15-foot Anechoic Wind Tunnel. Three inlet configurations were tested with cut-on and cutoff stator vane sets. The cutoff stator was designed to suppress all modes at the blade passing frequency. Rotating rake measurements indicate that several extraneous circumferential modes were active. The mode orders suggest that their source was an interaction between the rotor and small interruptions in the casing tip treatment. The cut-on stator produced the expected circumferential modes plus higher levels of the unexpected modes seen with the cutoff stator

The Weak Scale from BBN

The measured values of the weak scale, $v$, and the first generation masses, $m_{u,d,e}$, are simultaneously explained in the multiverse, with all these parameters scanning independently. At the same time, several remarkable coincidences are understood. Small variations in these parameters away from their measured values lead to the instability of hydrogen, the instability of heavy nuclei, and either a hydrogen or a helium dominated universe from Big Bang Nucleosynthesis. In the 4d parameter space of $(m_u,m_d,m_e,v)$, catastrophic boundaries are reached by separately increasing each parameter above its measured value by a factor of $(1.4,1.3,2.5,\sim5)$, respectively. The fine-tuning problem of the weak scale in the Standard Model is solved: as $v$ is increased beyond the observed value, it is impossible to maintain a significant cosmological hydrogen abundance for any values of $m_{u,d,e}$ that yield both hydrogen and heavy nuclei stability. For very large values of $v$ a new regime is entered where weak interactions freeze out before the QCD phase transition. The helium abundance becomes independent of $v$ and is determined by the cosmic baryon and lepton asymmetries. To maintain our explanation of $v$ from the anthropic cost of helium dominance then requires universes with such large $v$ to be rare in the multiverse. Implications of this are explored, including the possibility that new physics below 10 TeV cuts off the fine-tuning in $v$.Comment: 26 pages plus appendix, 13 figure

A multimedia tutorial shell with qualitative assessment in biology

The project is developing methods to produce multimedia tutorials relatively quickly and cheaply, using a generic software shell suitable for any subject area. The shell is a version of one produced originally as part of the HEFC-funded TLTP initiative by the Biodiversity Consortium. Tutorials presented in the shell will provide the student with a structured learning experience that will allow their initial knowledge level or their knowledge acquisition and progress to be qualitatively and quantitatively assessed. Where areas of weakness are revealed by the assessment, students will be advised to study particular parts of the tutorial in order to improve their understanding