We compared selection of northern Yellowstone elk (Cervus elaphus) by hunters in the Gardiner Late Hunt and northern Yellowstone wolves (Canis lupus) with regard to sex, age, and impacts to recruitment. We compared harvest data from 1996–2001 with wolf‐killed elk data from 1995–2001. We assessed the effects of hunting and wolf predation on reproductive female elk by constructing a life table and calculating reproductive values for females in the northern Yellowstone herd. We devised an index of total reproductive impact to measure impacts to calf production due to hunting and wolf predation. The age classes of female elk selected by wolves and hunters were significantly different. Hunters selected a large proportion of female elk with the greatest reproductive values, whereas wolves selected a large proportion of elk calves and older females with low reproductive values. The mean age of adult females killed by hunters throughout the study period was 6.5 years, whereas the mean age of adult females killed by wolves was 13.9 years. Hunting exerted a greater total reproductive impact on the herd than wolf predation. The combined effects of hunters killing prime‐aged females (2–9 yr old), wolves killing calves, and predation by other predators has the potential to limit the elk population in the future. Yellowstone is unique in this regard because multiple predators that occur sympatrically, including hunters, wolves, grizzly bears (Ursus arctos), black bears (Ursus americanus), cougars (Felis concolor), and coyotes (Canis latrans), all prey on elk. Using an Adaptive Harvest Management process the known female elk harvest during the Gardiner Late Hunt has been reduced by 72% from 2,221 elk in 1997 to 620 elk in 2004. In the future, hunting harvest levels may be reduced further to partially offset elk losses to wolves, other predators, and environmental factors.

BACKGROUND: When the coronavirus pandemic caused widespread school and business closures in March 2020, blood drives were cancelled and the supply of blood decreased suddenly in the United States (US). In response, hospital-based transfusion medicine physicians instituted policies to conserve blood and decrease blood product usage. These efforts were aided by the US Surgeon General recommendation to cancel all elective procedures. Nevertheless, the duration, severity, and impact of the pandemic on the national blood supply was uncertain. Hospitals with in-house donor programs had the opportunity not only to control demand, but also increase supply. STUDY DESIGN AND METHODS:A hospital-based blood donor center was rapidly mobilized to increase the supply of in-house collected blood, in order to counteract a sudden but potentially long-term depletion of the national blood supply during a pandemic. RESULTS:Collections increased approximately 5-fold above baseline for whole blood units, while apheresis platelet units were maintained at the historical average for the blood donor center.Cancellation of elective procedures showed a modest, but not yet statistically significant decrease in average blood product usage per day, nevertheless the in-house collection rate was sufficient to meet demand. CONCLUSION:A hospital-based blood donor center can quickly increase collection volumes and capacity in the face of a national emergency / pandemic. The desire to collect units should be balanced with safety concerns, need for sustainability, and blood product demand.

Approximately 30% of temporomandibular joint (TMJ) disorders include degenerative changes to the articular disc, with sex-specific differences in prevalence and severity. Limited tensile biomechanical properties of human TMJ discs have been reported. Stress relaxation tests were conducted on TMJ disc specimens harvested bilaterally from six males and six females (68.9 ± 7.9 years), with step-strain increments of 5%, 10%, 15%, 20% and 30%, at 1% strain-per-second. Stress versus strain plots were constructed, and Young’s Modulus, Instantaneous Modulus and Relaxed Modulus were determined. The effects of direction, region, and sex were examined. Regional effects were significant (p<0.01) for Young’s Modulus and Instantaneous Modulus. Anteroposteriorly, the central region was significantly stiffer than medial and lateral regions. Mediolaterally, the posterior region was significantly stiffer than central and anterior regions. In the central region, anteroposteriorly directed specimens were significantly stiffer compared to mediolateral specimens (p<0.04). TMJ disc stiffness, indicated by Young’s Modulus and Instantaneous Modulus, were higher in directions corresponding to high fiber alignment. Additionally, human TMJ discs were stiffer for females compared to males, with higher Young’s Modulus and Instantaneous Modulus, and female TMJ discs relaxed less. However, sex effects were not statistically significant. Using second-harmonic generation microscopy, regional collagen fiber organization was identified as a potentially significant factor in determining the biomechanical properties for any combination of direction and region. These findings establish structure-function relationships between collagen fiber direction and organization with biomechanical response to tensile loading, and may provide insights into the prevalence of TMJ disorders among women.

The objective of this study was to examine the impact of mechanical loading on solute transport in porcine temporomandibular joint (TMJ) discs using the electrical conductivity method. The electrical conductivity, as well as ion diffusivity, of TMJ discs was determined under confined compression with 3 strains in 5 disc regions. The average electrical conductivity over the 5 regions (mean ± SD) at 0% strain was 3.10 ± 0.68 mS/cm, decreased to 2.76 ± 0.58 mS/cm (-11.0%) at 10% strain, and 2.38 ± 0.55 mS/cm (-22.2%) at 20% compressive strain. Correspondingly, the average relative ion diffusivity (mean ± SD) at 0% strain was 0.273 ± 0.055, decreased to 0.253 ± 0.048 (-7.3%) at 10% strain, and 0.231 ± 0.048 (-15.4%) at 20% compressive strain. These results indicated that compressive strain impeded solute transport in the TMJ disc. Furthermore, our results showed that the transport properties of TMJ discs were regiondependent. The electrical conductivity and ion diffusivity in the anterior region were significantly higher than in the posterior region. This regional difference is likely due to the significant differences of tissue hydration between these 2 regions. This study provides important insight into the electrical and solute transport behaviors in TMJ discs under mechanical loading and aids in the understanding of TMJ pathophysiology related to tissue nutrition.

This study investigated the effect of mechanical strain on solute diffusion in human TMJ discs (mean cadaver age 77.8) using the electrical conductivity method. The electrical conductivity, as well as small ion diffusivity, of male and female TMJ discs was determined under three compressive strains. In the male group, the average disc electrical conductivity (mean ± sd) at 0% strain was 5.14±0.97 mS/cm, decreased to 4.50±0.91 mS/cm (−12.3%) at 10% strain, and 3.93±0.81 mS/cm (−23.5%) at 20% compressive strain. Correspondingly, the average disc relative ion diffusivity at 0% strain was 0.44±0.08, decreased to 0.40±0.08 (−8.9%) at 10% strain, and 0.36±0.08 (−16.7%) at 20% compressive strain. In the female group, the average disc electrical conductivity at 0% strain was 5.84±0.59 mS/cm, decreased to 5.01±0.50 mS/cm (−14.2%) at 10% strain, and 4.33±0.46 mS/cm (−25.8%) at 20% compressive strain. Correspondingly, the average disc relative ion diffusivity at 0% strain was 0.49±0.05, decreased to 0.43±0.04 (−11.3%) at 10% strain, and 0.39±0.04 (−19.9%) at 20% compressive strain. The results indicated that mechanical strain significantly impeded solute diffusion through the disc. This mechanical strain effect was larger in the female than in the male human TMJ disc. This study may provide new insights into TMJ pathophysiology.