Hydrostatic Pressure Project: Linked-Class Problem-Based Learning In Engineering

Over the last few years, WTAMU Mathematics, Engineering and Science faculty has used interdisciplinary projects as the basis for implementation of a linked-class approach to Problem-Based Learning (PBL). A project that has significant relevance to engineering statics, fluid mechanics, and calculus is the Hydrostatic Pressure Project. This project was developed by faculty associated with the NSF-funded INCRSE project, Increasing Numbers and Connections in Science, Math, and Engineering, for application of the linked-class PBL to calculus II and engineering statics. The students in the linked classes were to predict the horizontal force and the vertical force on a submerged surface and determine the appropriate locations of these forces in order to experimentally verify the calculations. They worked in groups to outline their procedures, develop their functional relations, record experimental data, and report on their findings. Assessment efforts have focused on student laboratory reports and student perceptions about their learning and experiences with this linked-class PBL project collected through surveys and focus groups. In all the surveys and focus groups conducted with students who had participated in the Hydrostatic Pressure Project, all of the students felt their experience was beneficial and had enhanced their understanding and applications of engineering and mathematics

Continuously tunable modulation scheme for precision control of optical cavities with variable detuning

We present a scheme for locking optical cavities with arbitrary detuning by many linewidths from resonance using an electro-optic modulator that can provide arbitrary ratios of amplitude-to-phase modulation. We demonstrate our scheme on a Fabry–Perot cavity, and show that a well-behaved linear error signal can be obtained by demodulating the reflected light from a cavity that is detuned by several linewidths.National Science Foundation (U.S.) (PHY-0757058

Continuous detuning of an optical cavity with a Universally Tunable Modulator

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 51).It is currently well-known how to lock an optical cavity on resonance using the Pound- Drever-Hall technique. It is also possible to lock a cavity at a single detuned length using an amplitude modulated laser beam. However, there are many interesting applications, that would benefit from the use of a Universally Tunable Modulator (UTM), because it can create any ratio of amplitude to phase modulation. The unique transfer function of the UTM allows for cavity locking at any of the intermediate points between resonance and about half a linewidth of detuning. In this thesis, we construct such a UTM and verify experimentally that the modulator can indeed be used for continuous detuning of optical cavities.by Emily Davis.S.B

Fossil gaps inferred from phylogenies alter the apparent nature of diversification in dragonflies and their relatives

<p>Abstract</p> <p>Background</p> <p>The fossil record has suggested that clade growth may differ in marine and terrestrial taxa, supporting equilibrial models in the former and expansionist models in the latter. However, incomplete sampling may bias findings based on fossil data alone. To attempt to correct for such bias, we assemble phylogenetic supertrees on one of the oldest clades of insects, the Odonatoidea (dragonflies, damselflies and their extinct relatives), using MRP and MRC. We use the trees to determine when, and in what clades, changes in taxonomic richness have occurred. We then test whether equilibrial or expansionist models are supported by fossil data alone, and whether findings differ when phylogenetic information is used to infer gaps in the fossil record.</p> <p>Results</p> <p>There is broad agreement in family-level relationships between both supertrees, though with some uncertainty along the backbone of the tree regarding dragonflies (Anisoptera). "Anisozygoptera" are shown to be paraphyletic when fossil information is taken into account. In both trees, decreases in net diversification are associated with species-poor extant families (Neopetaliidae, Hemiphlebiidae), and an upshift is associated with Calopterygidae + Polythoridae. When ghost ranges are inferred from the fossil record, many families are shown to have much earlier origination dates. In a phylogenetic context, the number of family-level lineages is shown to be up to twice as high as the fossil record alone suggests through the Cretaceous and Cenozoic, and a logistic increase in richness is detected in contrast to an exponential increase indicated by fossils alone.</p> <p>Conclusions</p> <p>Our analysis supports the notion that taxa, which appear to have diversified exponentially using fossil data, may in fact have diversified more logistically. This in turn suggests that one of the major apparent differences between the marine and terrestrial fossil record may simply be an artifact of incomplete sampling. Our results also support previous notions that adult colouration plays an important role in odonate radiation, and that Anisozygoptera should be grouped in a single inclusive taxon with Anisoptera, separate from Zygoptera.</p

Hospital discharges for fever and neutropenia in pediatric cancer patients: United States, 2009

Background Fever and neutropenia (FN) is a common complication of pediatric cancer treatment, but hospital utilization patterns for this condition are not well described. Methods Data were analyzed from the Kids’ Inpatient Database (KID), an all-payer US hospital database, for 2009. Pediatric FN patients were identified using: age ≤19 years, urgent or emergent admit type, non-transferred, and a combination of ICD-9-CM codes for fever and neutropenia. Sampling weights were used to permit national inferences. Results Pediatric cancer patients accounted for 1.5 % of pediatric hospital discharges in 2009 (n = 110,967), with 10.1 % of cancer-related discharges meeting FN criteria (n = 11,261). Two-fifths of FN discharges had a “short length of stay” (SLOS) of ≤3 days, which accounted for approximately $65.5 million in hospital charges. Upper respiratory infection (6.0 %) and acute otitis media (AOM) (3.7 %) were the most common infections associated with SLOS. Factors significantly associated with SLOS included living in the Midwest region (OR = 1.65, 1.22–2.24) or West region (OR 1.54, 1.11–2.14) versus Northeast, having a diagnosis of AOM (OR = 1.39, 1.03–1.87) or viral infection (OR = 1.63, 1.18–2.25) versus those without those comorbidities, and having a soft tissue sarcoma (OR = 1.47, 1.05–2.04), Hodgkin lymphoma (OR = 2.33, 1.62–3.35), or an ovarian/testicular tumor (OR = 1.76, 1.05–2.95) compared with patients without these diagnoses. Conclusion FN represents a common precipitant for hospitalizations among pediatric cancer patients. SLOS admissions are rarely associated with serious infections, but contribute substantially to the burden of hospitalization for pediatric FN

Co-managing wildfire suppression in southwestern Utah

2 pagesIn a given area, there are commonly multiple agencies that manage wildfire suppression on different jurisdictions. These agencies can face divergent or even competing missions and mandates, yet must also address the cross-boundary nature of managing wildfire risk. Therefore, how can they more effectively co-manage fire suppression? Co-management in this context refers to communication, coordination, and collaboration between entities for meaningful collective action that shares the resources, costs, and burdens of managing fire risk. We examine factors that facilitated and limited co-management in a case study in southwestern Utah.FUNDER: Joint Fire Science Program