Journals at the University of Arizona
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TISSUE DIELECTRIC CONSTANT RATIOS AS A METHOD TO CHARACTERIZE TRUNCAL LYMPHEDEMA
No full textTruncal lymphedema is one possible complication of breast cancer treatment. It affects many women and is diagnosed based on symptoms and clinical assessment. Because changes occur late in the process, it is useful to have a quantitative assessment that is applied earlier to detect more subtle changes and quantitively assess treatment progress. Our goal was to describe a possible method to accomplish this via measurements of tissue dielectric constant (TDC). TDC was measured at lateral thorax, anterior forearm, and biceps in 120 women awaiting surgery for breast cancer. Inter-side TDC ratios were defined as values measured on the at-risk (cancer-side) lateral thorax divided by TDC values measured on contralateral thorax, forearm, and biceps. These ratios, designated as thorax-thorax, thorax-forearm, and thorax- biceps were (mean ± SD) 1.017 ± 0.121, 1.138 ± 0.223, and 1.263 ± 0.255 respectively. Corresponding truncal lymphedema thresholds were determined by adding 2.5SD to each mean yielding thresholds of 1.32, 1.70 and 1.90. For these thresholds, 99.4% of patients would have inter-side ratios less than the threshold value. Thus, from assessments in a non-lymphedematous patient-group a set of reference threshold-ratios are now available against which patients surgically treated for breast cancer may be prospectively compared
Third Language Acquisition: Evolving Perspectives
No full textThis paper critically reviews the evolving perspectives and disciplinary developments in the field of third language acquisition. It illustrates three of the most prominent and widely discussed models, namely Cumulative Enhancement Model (Flynn, Foley, Vinnitskaya, 2004), L2 Status Factor Model (Bardel Falk, 2007), Typological Primacy Model (Rothman, 2011), and their later developments/refinements. Based on the comparison of the three models, this article continues with a survey of up-to-date empirical studies and further reconciles the current conflicting findings. It points out potential factors and deficiencies of research designs, including selection of participants, languages involved, linguistic features examined, and elicitation instruments, that may have led to controversial findings. Built upon the critical investigation of existing theoretical frameworks and empirical studies, this paper moves beyond the three models, brings in perspectives that are overlooked in prior research, and identifies the future research directions in the field of third language acquisition
Success Rates Depend on the Appropriateness of the Outcome Measures
No full textThis "Cheap Lessons" article emphasizes the importance of selecting an appropriate outcome. A brief example from the sports medicine literature relating to baseball pitching performance and the “Tommy John surgery” (TJS) is discussed. The example illustrates how an inappropriate outcome measure often utilized in studies involving the TJS has resulted in deceptive, overestimates of the surgery’s success rate. The unintended consequence of this methodological miscalculation is that numerous athletes have elected to pursue this unnecessary medical procedure and put both their health and sporting careers at risk
Differences in Plant Species Composition as Evidence of Alternate States in the Sagebrush Steppe
No full textState-and-transition models (STMs), conceptual models of vegetation change based on alternate state theory, are increasingly applied as tools for land management decision-making. As STMs are created throughout the United States, it is crucial to ensure that they are supported by ecological evidence. Plant species composition reflects ecosystem processes that are difficult to measure and may be a useful indicator of alternate states. This study aims to create data-driven STMs based on plant species composition for two ecological sites (Claypan and Mountain Loam) in northwestern Colorado sagebrush steppe. We sampled 76 plots with different management and disturbance histories. Drawing on the hierarchical approach currently taken to build STMs, we hypothesized that A) differences in species composition between the two ecological sites would be related toenvironmental factors and B) differences in species composition within each ecological site would be related to management and disturbance history. Relationships among species composition, site history, and environmental variables were evaluated using multivariate statistics. We found that between ecological sites, species composition was related to differences in soil texture, supporting Hypothesis A and the creation of separate STMs for each site. Within ecological sites, species composition was related to site history and also to environmental variation. This finding partially supports Hypothesis B and the identification ofalternate states using species composition, but also suggests that these ecological sites are not uniform physical templates upon which plant community dynamics play out. This data-driven, plant species–based approach created two objective, credible STMs with states and transitions that are consistent with the sagebrush steppe literature. Our findings support the hierarchical view of landscapes currently applied in building STMs. An approach that acknowledges environmental heterogeneity within ecological sites is necessary to help define finer-resolution ecological sites and elucidate cases in which specific abiotic conditions make transitions between states more likely
Assessing the Success of Postfire Reseeding in Semiarid Rangelands Using Terra MODIS
No full textSuccessful postfire reseeding efforts can aid rangeland ecosystem recovery by rapidly establishing a desired plant community and thereby reducing the likelihood of infestation by invasive plants. Although the success of postfire remediation is critical, few efforts have been made to leverage existing geospatial technologies to develop methodologies to assess reseeding success following a fire. In this study, Terra Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data were used toimprove the capacity to assess postfire reseeding rehabilitation efforts, with particular emphasis on the semiarid rangelands of Idaho. Analysis of MODIS data demonstrated a positive effect of reseeding on rangeland ecosystem recovery, as well as differences in vegetation between reseeded areas and burned areas where no reseeding had occurred (P,0.05). We conclude that MODIS provides useful data to assess the success of postfire reseeding
Mowing Wyoming Big Sagebrush Communities With Degraded Herbaceous Understories: Has a Threshold Been Crossed?
No full textWyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle A. Young] S.L. Welsh) plant communities with degraded native herbaceous understories occupy vast expanses of the western United States. Restoring the native herbaceous understory in these communities is needed to provide higher-quality wildlife habitat, decrease the risk of exotic plant invasion, and increase forage for livestock. Though mowing is commonly applied in sagebrush communities with the objective of increasing native herbaceous vegetation, vegetation response to this treatment in degradedWyoming big sagebrush communities is largely unknown. We compared mowed and untreated control plots in five Wyoming big sagebrush plant communities with degraded herbaceous understories in eastern Oregon for 3 yr posttreatment. Native perennial herbaceous vegetation did not respond to mowing, but exotic annuals increased with mowing. Density of cheatgrass (Bromus tectorum L.), a problematicexotic annual grass, was 3.3-fold greater in the mowed than untreated control treatment in the third year posttreatment. Annual forb cover, largely consisting of exotic species, was 1.8-fold greater in the mowed treatment compared to the untreated control in the third year posttreatment. Large perennial grass cover was not influenced by mowing and remained below 2%. Mowing does not appear to promote native herbaceous vegetation in degraded Wyoming big sagebrush plant communities and may facilitate the conversion of shrublands to exotic annual grasslands. The results of this study suggest that mowing, as a standalonetreatment, does not restore the herbaceous understory in degraded Wyoming big sagebrush plant communities. We recommend that mowing not be applied in Wyoming big sagebrush plant communities with degraded understories withoutadditional treatments to limit exotic annuals and promote perennial herbaceous vegetation
Cross-university collegiality: Supporting 21st century cooperation in preservice English Language Arts teachers
No full textAs preservice teachers develop ideas about what it means to be and become educators, they benefit from opportunities that allow them to experience cooperative group work with diverse populations. This is especially important because during the induction phase, as they cross over from teacher education students to inservice teachers, they are often expected to engage in collegial work with their coworkers. In this article, the authors describe a cross-university project using a digital platform that afforded two sets of preservice teachers from two different universities to cooperate over the course of four weeks to inform each other’s practice. This cooperative project included peer review sessions focused on lesson plans and synchronous revision conferences as part of a digital learning community. The authors considered the affordances and limitations of using an online platform as a way to foster cooperative practice among preservice teachers. Overall, preservice teachers had a positive perception of this project. In this article, we share the planning and implementation of the project, the ways in which students engaged with both their peers and the digital tools, and the trials and tribulations of the authors as instructors of these two cohorts of preservice teachers. Ultimately, our goal is to highlight the need in teacher education for projects that engage preservice teachers in cooperative practice with both the use of digital tools and authentic conversations with others outside of their own educational communities. DOI:10.2458/azu_itet_v6i1_rybakov
