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Background: Pectoralis major (PM) tendon tears are common injuries in athletic patient populations, where operative repair is largely recommended for maximum functional recovery. The repair varies in difficulty and technique based on the location of the tear within the muscle-tendon unit. Magnetic resonance imagining (MRI) has been reported to be sensitive and specific for identifying the tear location, but the effect of injury mechanism on tear pattern has not been previously investigated. Purpose: To examine PM tears in a military patient population and assess the effect of injury mechanism (weightlifting vs high-energy trauma) on the tear pattern and accuracy of MRI interpretation. Study Design: Cohort study; Level of evidence, 3. Methods: Active duty military servicemembers undergoing operative repair of PM tendon tears with corresponding preoperative MRIs from 2 medical centers were identified. Two musculoskeletal fellowship–trained radiologists reviewed imaging studies, reporting the location of the tear within the muscle-tendon unit and the severity of the tear (sternal head vs clavicular head vs both). Radiographic findings were compared against intraoperative findings. Mechanism of injury and timing from injury to imaging and surgery were assessed to determine whether they affected the accuracy of MRI interpretations. Results: A total of 72 patients were included (mean ± SD age, 33.7 ± 7.0 years; 100% male). Mechanisms of injury consisted of 46 weightlifting injuries and 26 high-energy injuries. Interrater reliability was poor for tear location (kappa, 0.162; P = .003) but substantial for extent of tear (kappa, 0.637; P < .0001). MRI had a 51.3% sensitivity and 63.6% specificity for identifying complete tears. MRI had a sensitivity of 73.9% and specificity of 72.2% for avulsion injuries and sensitivity of 75% and specificity of 79.3% for musculotendinous injuries. Mechanism of injury had no effect on extent of the tear but did affect the location of the tear, with a higher rate of avulsion injuries in the high-energy mechanism cohort (81% vs 40%; P = .02). Conclusion: The mechanism of injury was found to significantly affect the location of tendon tears. A higher rate of avulsion injuries was found in high-energy injuries than weightlifting injuries. MRI appeared to be less sensitive and specific than previous reports for traumatic PM tendon injuries.

In recent decades, environmental drivers of community change have been associated with changes in biodiversity from local to global scales. Here we evaluate the role of anthropogenic drivers in marine ecosystems as drivers of change in local species richness with a meta-analysis of a novel dataset of temporal change in species richness. We paired biodiversity data from 144 sites with large-scale drivers derived from geospatial databases: human cumulative impact scores, sea surface temperature change, nutrient loading, and invasion potential. Three specific drivers (nutrient inputs, rate of linear temperature change, and non-native species invasion potential) explained patterns in local marine species richness change. We show that these drivers have opposing effects on biodiversity trends. In some cases, variability in drivers can create contrasting directions of change yielding observations of no net change when localities are pooled in an attempt to find a global average. Further, long-term studies reveal different effects of drivers that are not observed in short-term studies. These findings begin to explain high variability observed in species diversity trends at local scales. Formally attributing local species diversity change to human drivers is essential to understanding global patterns of local species diversity change and their consequences.

High rates of inorganic fertilizers are used in conventional intensive production systems such as Abies fraseri (fraser fir) cropping systems for Christmas trees. Groundcovers can be used as green mulches, help reduce the use of farm chemicals, and provide several environmental benefits. We investigated the performance of a low-input cropping system by combining two legume cover crops [Dutch white clover (Trifolium repens) and alfalfa (Medicago sativa)] in combination with low rates of inorganic fertilizers as a step toward a more sustainable production system. The randomized block design comprised one cover crop and one of three applications of reduced rate inorganic fertilizer (75%, 50%, and 25% of the recommended rate). A conventional system using herbicides for weed control and the 100% rate of inorganic fertilizer was used as a control. Parameters measured included tree morphology, foliar nitrogen concentration, soil mineral nitrogen, and nitrate-N leaching below the root zone. A significant positive growth response (height and diameter) was obtained in all alfalfa-based cropping systems. This was accompanied by foliar nutrient concentrations similar to conventional plots and a reduction in nitrate-N leaching. However, in white clover-based cropping systems, the growth response was reduced (both height and diameter), suggesting competition for soil resources. In addition, the total nitrate-N leaching was higher in this system, suggesting an imbalance between mineral nitrogen availability and use in white clover-based cropping systems. We conclude that if the potential competition between cover crops and trees can be properly managed, legume cover crops can be effectively used to make intensive production tree-based systems more sustainable. Further studies related to mineralization and macronutrient flows are needed before any definite recommendation can be made about the use of these systems in large-scale production systems.