Development of a Valid and Reliable Job Performance Formative Feedback Instrument for High School Activities Directors

The problem of the study was to develop and test for validity and reliability, a 20-item, 360-degree formative feedback instrument for assessing the performance of high school activities directors. Data were collected from coaches, extra-curricular advisors, licensed staff members, non-licensed staff members, and administrators regarding activities directors’ performances. Contributing high schools in the state of Minnesota participated in the study during the spring of 2017. A standard statistical item analysis was completed to calculate basic descriptive statistics and a Cronbach’s (1951) alpha to determine reliability. In addition, a pilot test and content analysis of the items was conducted to determine and ensure validity. The study resulted in a valid and reliable instrument, which may be used by activities directors, their supervisors, and constituents for a formative performance appraisal process. The instrument was designed to provide job-specific feedback from a variety of constituents to activities directors regarding performance. The findings resulted in a reliability correlation coefficient ranging from .88 to .93. The instrument was found to have alpha correlation coefficients above the .70 threshold, which is strong reliability. The formative feedback instrument was pilot tested with practitioners from the education field that render knowledge of the activities director position. Individuals were requested to review the formative feedback instrument for adequacy of appropriate language, format, font, clarity, user friendliness, and validity of items. Along with pilot testing the 20-item instrument, content validity was established through an extensive literature review. The formative feedback instrument will be added to the Wedin (2013) self-evaluation instrument and supervisor evaluation instrument developed previously as part of an Activities Director’s Performance Appraisal Handbook

Extinctions of aculeate pollinators in Britain and the role of large-scale agricultural changes

Pollinators are fundamental to maintaining both biodiversity and agricultural productivity, but habitat destruction, loss of flower resources, and increased use of pesticides are causing declines in their abundance and diversity. Using historical records we assessed the rate of extinction of bee and flower-visiting wasp species in Britain, from the mid 19th century to the present. The most rapid phase of extinction appears to be related to changes in agricultural policy and practice beginning in the 1920s, before the agricultural intensification prompted by the Second World War, often cited as the most important driver of biodiversity loss in Britain. Slowing of the extinction rate from the 1960s onwards may be due to prior loss of the most sensitive species and/or effective conservation programs

Biodiversity and decomposition in experimental grassland ecosystems

We examined the impact of biodiversity on litter decomposition in an experiment that manipulated plant species richness. Using biomass originating from the experimental species richness gradient and from a species used as a common substrate, we measured rates of decomposition in litterbags in two locations: in situ in the experiment plots and in an adjacent common garden. This allowed us to separate the effects of litter quality and decomposition location on decomposition. We found that plant species richness had a significant, but minor negative effect on the quality (nitrogen concentration) of the biomass. Neither litter type nor location had a consistent effect on the rate of carbon and nitrogen loss over a 1-year period. Thus, the increased productivity and corresponding lower soil available nitrogen levels observed in high diversity plots do not lead to faster litter decomposition or faster nitrogen turnover. This supports the hypothesis that increased productivity corresponding with higher species richness results in increased litter production, higher standing litter pools and a negative feedback on productivity, because of an increased standing nitrogen pool in the litter

Diagnostic Accuracy of Clinical Tests Assessing Ligamentous Injury of the Talocrural and Subtalar Joints: A Systematic Review With Meta-Analysis

Context: Ankle sprains are the most common acute musculoskeletal injury. Clinical tests represent the first opportunity to assess the sprain's severity, but no systematic review has compared these tests to contemporary reference standards. Objective: To determine the diagnostic accuracy of clinical tests assessing the talocrural and subtalar joint ligaments after ankle sprain. Data Sources: CINAHL, EMBASE, MEDLINE, hand-searching, and PubMed-related article searches (inception to November 18, 2020). Study Selection: Eligible diagnostic studies compared clinical examination (palpation, joint laxity) against imaging or surgery. Studies at a high risk of bias or with high concerns regarding applicability on Quality Assessment of Diagnostic Accuracy Studies-2 were excluded from the meta-analysis. Study Design: Systematic review and meta-analysis. Level of Evidence: Level 3a. Data Extraction: True-positive, false-negative, false-positive, and true-negative findings were extracted to calculate sensitivity, specificity, and likelihood ratios. If ordinal data were reported, these were extracted to calculate Cohen's kappa. Results: A total of 14 studies met the inclusion criteria (6302 observations; 9 clinical tests). No test had both sensitivity and specificity exceeding 90%. Palpation of the anterior talofibular ligament is highly sensitive (sensitivity 95%-100%; specificity 0%-32%; min-max; n = 6) but less so for the calcaneofibular ligament (sensitivity 49%-100%; specificity 26%-79%; min-max; n = 6). Pooled data from 6 studies (885 observations) found a low sensitivity (54%; 95% CI 35%-71%) but high specificity (87%; 95% CI 63%-96%) for the anterior drawer test. Conclusion: The anterior talofibular ligament is best assessed using a cluster of palpation (rule out), and anterior drawer testing (rule in). The talar tilt test can rule in injury to the calcaneofibular ligament, but a sensitive clinical test for the ligament is lacking. It is unclear if ligamentous injury grading can be done beyond the binary (injured vs uninjured), and clinical tests of the subtalar joint ligaments are not well researched. The generalizability of our findings is limited by insufficient reporting on blinding and poor study quality

The Role of Litter Quality Feedbacks in Terrestrial Nitrogen and Phosphorus Cycling

Many studies in ecosystem ecology argue for strong control of litter quality over nitrogen (N) cycling. We developed a model for temperate grasslands to test the importance of litter quality in decomposition for N and phosphorus (P) cycling based on the following premises. First, terrestrial N and P cycling differ fundamentally because N is a structural component of the soil organic matter (SOM), whereas P is not. Secondly, SOM has a much lower C:N ratio than litter inputs. Thirdly, litter decomposition follows an exponential decay with 20% of the original litter mass turning into SOM. Fourth, litter N concentration shows an exponential increase during decomposition, whereas P does not change and is released proportionally to the litter mass. Based on these premises we constructed a model which shows that 0.75% N is a critical initial litter concentration at which concentration all N is immobilized and no N is released from the litter. Thus at 0.75% N of the litter all net N mineralization is through SOM decomposition and not through litter decomposition. Phosphorus, in contrast, is primarily released in the early stages of litter decomposition. Empirical tests of these model predictions support the applicability of the model to temperate grassland ecosystems. This model predicts that N mineralization from SOM is much more important than mineralization from litter and that plant litter quality differences alone cannot explain ecosystem N cycling patterns. Phosphorus, in contrast, does cycle largely through litter decomposition, and plant litter quality differences are the dominant factor in determining ecosystem P cycling feedbacks

Smoothed Analysis of Tensor Decompositions

Low rank tensor decompositions are a powerful tool for learning generative models, and uniqueness results give them a significant advantage over matrix decomposition methods. However, tensors pose significant algorithmic challenges and tensors analogs of much of the matrix algebra toolkit are unlikely to exist because of hardness results. Efficient decomposition in the overcomplete case (where rank exceeds dimension) is particularly challenging. We introduce a smoothed analysis model for studying these questions and develop an efficient algorithm for tensor decomposition in the highly overcomplete case (rank polynomial in the dimension). In this setting, we show that our algorithm is robust to inverse polynomial error -- a crucial property for applications in learning since we are only allowed a polynomial number of samples. While algorithms are known for exact tensor decomposition in some overcomplete settings, our main contribution is in analyzing their stability in the framework of smoothed analysis. Our main technical contribution is to show that tensor products of perturbed vectors are linearly independent in a robust sense (i.e. the associated matrix has singular values that are at least an inverse polynomial). This key result paves the way for applying tensor methods to learning problems in the smoothed setting. In particular, we use it to obtain results for learning multi-view models and mixtures of axis-aligned Gaussians where there are many more "components" than dimensions. The assumption here is that the model is not adversarially chosen, formalized by a perturbation of model parameters. We believe this an appealing way to analyze realistic instances of learning problems, since this framework allows us to overcome many of the usual limitations of using tensor methods.Comment: 32 pages (including appendix

Scytinium pulvinatum comb

Abstract In this paper Collema pulvinatum Hoffm. is synonymized under Scytinium pulvinatum (Hoffm.) Otálora, P.M. Jørg. & Wedin, providing "Leptogium" pulvinatum with a formal name