The Best Lied Plans: Engaging Undergraduate Participation in Fieldwork

This paper describes a field project from an introductory soils course taught in spring 2001. Looking at soils in the field is a necessity, since the physical details of soils cannot be readily reproduced in a class or lab setting.Convincing students that crawling into a muddy hole will help them learn does not always work. So I conceived a plan to inspire the class about looking at soil in the field. I used geography as a starting point, by selecting an extraordinary environmental setting for the field project. Then I fully developed a research project for the class, including hypotheses to be tested and provided ample background information. I followed the lead of television and peppered advertisements for the project throughout lectures, overemphasizing several aspects with the aim to entice the students into the field. The combination of preparation and marketing resulted in a hugely successful field experience

Geographic variation in empathy: A state-level analysis

Empathy is often studied at the individual level, but little is known about variation in empathy across geographic regions and how this variation is associated with important regional-level outcomes. The present study examined associations between state-level empathy, prosocial behavior, and antisocial behavior in the United States. Participants were 79,563 U.S. residential adults who completed measures of cognitive and emotional empathy (i.e., perspective taking and empathic concern). Information on prosocial and antisocial behavior was retrieved from publicly available government databases. All indices of empathy were related to lower rates of violent crime, aggravated assault, and robbery. Total empathy was associated with higher well-being and higher volunteer rates. Implications for geographic variation in empathy, prosocial behavior, and antisocial behavior are discussed

Natural History of the Ahlstrom’s and Roose’s Prairies, Olympic National Park, Washington

The objective of this research is to evaluate the wetland and forest dynamics in and around the Ozette Prairies to identify their origin and history since the Last Ice Age. The Ozette Prairies are treeless areas, dominated by unique associations of understory species in an otherwise heavily forested region. The prairies are historically (pre-European) persistent elements of the landscape in a region where the climate promotes forest growth. Presently, the prairies are undergoing encroachment by the surrounding forest. The patchy character of the vegetation attests to centuries, or more, of climate change, expansion and demise of forest populations and changing fire regimes. We used a suite of methods to address the environmental history of this landscape. The first phase of this project evaluated the soils of the vicinity (this research is on-going). The soils indicate that fire has been an important component in their formation. The second phase of the project begins to evaluate the incidence of fire on this landscape. Three approaches where taken: examining sediments accumulated in wetlands within the prairies, examining repeat aerial photographs of the prairies to document tree invasion, and vegetation sampling to identify tree demographics

Dye regeneration and charge recombination in dye-sensitized solar cells with ferrocene derivatives as redox mediators

Ferrocene compounds are promising redox shuttles for application in dye-sensitized solar cells (DSCs). Chemical modification of the cyclopentadienyl rings is easily achievable affording almost unlimited variation of the redox properties. This allows fine-tuning of the driving force for dye-regeneration and optimization of the energy conversion efficiency of DSCs. Herein, six ferrocene derivatives have been chosen for investigation which cover the large redox potential range of 0.85 V, by virtue of simple alkylation and halogenation of the cyclopentadienyl ring, and enable improved matching of the energy levels of the sensitizer and the electrolyte. Although the focus of this work was to examine the effect of the redox potential on charge transfer processes, DSCs were fabricated which achieved high energy conversion efficiencies of over 5%. Charge transfer reactions were studied to reveal the dependence of the dye regeneration rate, recombination losses and recombination pathways on the reaction driving force. An increase in redox potential led to a higher efficiency due to higher open circuit potentials until a threshold is reached. At this threshold, the driving force for dye regeneration (18 kJ DE ¼ 0.19 V) becomes too small for efficient device operation, leading to rapid recombination between the oxidized dye and electrons in the TiO2 conduction band. As a result of this work guidelines can be formulated to aid the selection of redox couples for a particular sensitizer in order to maximize the utilization of incident solar energy

Trends in Shoulder Stabilization Techniques Used in the United States Based on a Large Private-Payer Database

Background: Arthroscopic stabilization is the most broadly used surgical procedure in the United States for management of recurrent shoulder instability. Latarjet coracoid transfer has been considered a salvage surgical procedure for failed arthroscopic repairs or cases of significant glenoid bone loss; however, with recent literature suggesting reduced risk of recurrent instability with Latarjet, several surgeons have advocated its broader utilization as a primary operation for treatment of shoulder instability. Purpose: To determine trends in shoulder stabilization techniques used in the United States. Study Design: Cross-sectional study. Methods: A retrospective analysis of a publicly available national insurance database was performed to identify shoulder stabilization procedures performed over 9 years (2007-2015). The following Current Procedural Terminology codes were searched: 29806 (arthroscopic stabilization), 23455 (open capsulolabral repair), 23466 (open capsular shift), 23462 (Latarjet coracoid transfer), and 23460 (open anterior capsulorrhaphy with other bone block augmentation). Outcomes of interest included (1) trends in the use of each technique throughout the study interval, (2) age and sex distributions of patients undergoing each technique, and (3) regional predilections for the use of each technique. Results: Arthroscopic stabilization was the most broadly used shoulder stabilization procedure in the database (87%), followed by open Bankart (7%), Latarjet (3.2%), open capsular shift (2.6%), and alternative bone block procedure (0.8%). Throughout the study period, the incidence of arthroscopic stabilization and Latarjet increased (8% and 15% per year, respectively); the incidence of open capsular shift remained relatively constant; and the incidence of open Bankart decreased (9% per year). Arthroscopic stabilization, open Bankart, and Latarjet each had similar sex-based distributions (roughly 70% male), while open capsular shift and alternative bone block were relatively more common in females (54% and 50% male, respectively). The incidence of arthroscopic stabilization and Latarjet were greatest in the South and lowest in the Northeast. Conclusion: Arthroscopic stabilization remains the most commonly utilized stabilization technique in the United States. The use of the Latarjet procedure is steadily increasing and now rivals open Bankart stabilization among the most commonly used open stabilization techniques

Prognostic significance of vegetations detected by two-dimensional echocardiography in infective endocarditis

Although 2DE is considered the most sensitive method for detecting vegetations in infective endocarditis, the independent clinical significance of these vegetations continues to be debated. To further examine this, we identified 74 patients who were diagnosed as having infective endocarditis over a 54-month period. The 50 patients who underwent 2DE examination form the basis of this report. Definite vegetations were present in 21 (42%) patients and measured 1.2 +/- 0.2 cm2. The vegetation was localized to the aortic valve in 10 patients, the mitral valve in eight, and the tricuspid valve in three. A major complication, defined as death, new-onset congestive heart failure, major arterial embolus, or valve surgery occurred in 86% of the vegetative endocarditis patients compared to 62% of those without vegetations. Among those patients with vegetations, death occurred in 24%, heart failure in 38%, arterial embolus in 48%, and surgery in 43%. This compared to 7%, 21%, 21%, and 24%, respectively, in those patients without vegetations. These data support the concept that 2DE detection of a vegetation defines a high-risk subgroup of patients with infective endocarditis in whom careful monitoring and aggressive management are warranted.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25968/1/0000034.pd

A Geometric Formulation of Quantum Stress Fields

We present a derivation of the stress field for an interacting quantum system within the framework of local density functional theory. The formulation is geometric in nature and exploits the relationship between the strain tensor field and Riemannian metric tensor field. Within this formulation, we demonstrate that the stress field is unique up to a single ambiguous parameter. The ambiguity is due to the non-unique dependence of the kinetic energy on the metric tensor. To illustrate this formalism, we compute the pressure field for two phases of solid molecular hydrogen. Furthermore, we demonstrate that qualitative results obtained by interpreting the hydrogen pressure field are not influenced by the presence of the kinetic ambiguity.Comment: 22 pages, 2 figures. Submitted to Physical Review B. This paper supersedes cond-mat/000627

Selecting patients for randomized trials: a systematic approach based on risk group

BACKGROUND: A key aspect of randomized trial design is the choice of risk group. Some trials include patients from the entire at-risk population, others accrue only patients deemed to be at increased risk. We present a simple statistical approach for choosing between these approaches. The method is easily adapted to determine which of several competing definitions of high risk is optimal. METHOD: We treat eligibility criteria for a trial, such as a smoking history, as a prediction rule associated with a certain sensitivity (the number of patients who have the event and who are classified as high risk divided by the total number patients who have an event) and specificity (the number of patients who do not have an event and who do not meet criteria for high risk divided by the total number of patients who do not have an event). We then derive simple formulae to determine the proportion of patients receiving intervention, and the proportion who experience an event, where either all patients or only those at high risk are treated. We assume that the relative risk associated with intervention is the same over all choices of risk group. The proportion of events and interventions are combined using a net benefit approach and net benefit compared between strategies. RESULTS: We applied our method to design a trial of adjuvant therapy after prostatectomy. We were able to demonstrate that treating a high risk group was superior to treating all patients; choose the optimal definition of high risk; test the robustness of our results by sensitivity analysis. Our results had a ready clinical interpretation that could immediately aid trial design. CONCLUSION: The choice of risk group in randomized trials is usually based on rather informal methods. Our simple method demonstrates that this decision can be informed by simple statistical analyses

Infrared cameras overestimate skin temperature during rewarming from cold exposure

This is an accepted manuscript of an article published by Elsevier in Journal of Thermal Biology on 03/05/2020, available online: https://doi.org/10.1016/j.jtherbio.2020.102614 The accepted version of the publication may differ from the final published version.Objective The primary aim of this study was to assess the accuracy of an infrared camera and that of a skin thermistor, both commercially available. The study aimed to assess the agreement over a wide range of skin temperatures following cold exposure. Methods Fifty-two males placed their right hand in a thin plastic bag and immersed it in 8 °C water for 30 min whilst seated in an air temperature of 30 °C. Following hand immersion, participants removed the bag and rested their hand at heart level for 10 min. Index finger skin temperature (Tsk) was measured with a thermistor, affixed to the finger pad, and an infrared camera measured 1 cm distally to the thermistor. Agreement between the infrared camera and thermistor was assessed by mean difference (infrared camera minus thermistor) and 95% limits of agreement analysis, accounting for the repeated measures over time. The clinically significant threshold for Tsk differences was set at ±0.5 °C and limits of agreement ±1 °C. Results As an average across all time points, the infrared camera recorded Tsk 1.80 (SD 1.16) °C warmer than the thermistor, with 95% limits of agreement ranging from −0.46 °C to 4.07 °C. Conclusion Collectively, the results show the infrared camera overestimated Tsk at every time point following local cooling. Further, measurement of finger Tsk from the infrared camera consistently fell outside the acceptable level of agreement (i.e. mean difference exceeding ±0.5 °C). Considering these results, infrared cameras may overestimate peripheral Tsk following cold exposure and clinicians and practitioners should, therefore, adjust their risk/withdrawal criteria accordingly.Published versio

Exploratory randomised controlled trial of a mindfulness-based weight loss intervention for women

To explore the efficacy of a mindfulness-based weight loss intervention for women. Sixty-two women (ages 19-64; BMI 22.5-52.1) who were attempting to lose weight were randomised to an intervention or control condition. The former were invited to attend four 2-h workshops, the latter were asked to continue with their normal diets. Data were collected at baseline, 4 and 6 months. BMI, physical activity, mental health. At 6 months intervention participants showed significantly greater increases in physical activity compared to controls (p<.05) but no significant differences in weight loss or mental health. However, when intervention participants who reported 'never' applying the workshop principles at 6 months (n=7) were excluded, results showed both significantly greater increases in physical activity (3.1 sessions per week relative to controls, p<.05) and significantly greater reductions in BMI (0.96 relative to controls, equivalent to 2.32 kg, p<0.5). Reductions in BMI were mediated primarily by reductions in binge eating. Despite its brevity, the intervention was successful at bringing about change. Further refinements should increase its efficacy