Seedling responses to soil moisture amount versus pulse frequency in a successfully encroaching semi-arid shrub.

Rainfall timing, frequency, and quantity is rapidly changing in dryland regions, altering dryland plant communities. Understanding dryland plant responses to future rainfall scenarios is crucial for implementing proactive management strategies, particularly in light of land cover changes concurrent with climate change. One such change is woody plant encroachment, an increasing abundance of woody plants in areas formerly dominated by grasslands or savannas. Continued woody plant encroachment will depend, in part, on seedling capacity to establish and thrive under future climate conditions. Seedling performance is primarily impacted by soil moisture conditions governed by precipitation amount (quantity) and frequency. We hypothesized that (H1) seedling performance would be enhanced by both greater soil moisture and pulse frequency, such that seedlings with similar mean soil moisture would perform best under high pulse frequency. Alternatively, (H2) mean soil moisture would have greater influence than pulse frequency, such that a given pulse frequency would have little influence on seedling performance. The hypotheses were tested with Prosopis velutina, a shrub native to the United States that has encroached throughout its range and is invasive in other continents. Seedlings were grown in a greenhouse under two soil moisture treatments, each which was maintained by two pulse frequency treatments. Contrary to H1, mean soil moisture had greater impact than pulse frequency on seedling growth, photosynthetic gas exchange, leaf chemistry, and biomass allocation. These results indicate that P. velutina seedlings may be more responsive to rainfall amount than frequency, at least within the conditions seedlings experienced in this experimental manipulation.

Nebulized Ketamine Used for Pain Management of Orthopedic Trauma.

BACKGROUND: Ketamine is a noncompetitive N-methyl-D-aspartate/glutamate receptor complex antagonist that decreases pain by diminishing central sensitization and hyperalgesia. When administered via i.v. (push-dose, short infusion, or continuous infusion) or intranasal routes, ketamine has shown to be effective in patients with acute traumatic pain. However, when i.v. access is not attainable or readily available, the inhalation route of ketamine administration via breath-actuated nebulizer (BAN) provides a noninvasive and titratable method of analgesic delivery. The use of nebulized ketamine has been studied in areas of postoperative management of sore throat and acute traumatic musculoskeletal and abdominal pain. To our knowledge, this is the first case series describing the use of nebulized ketamine for analgesia and orthopedic reduction. CASE SERIES: We describe 4 patients who presented to the emergency department with acute traumatic painful conditions (one patellar dislocation, one shoulder dislocation, and two forearm fractures) and received nebulized ketamine for management of their pain. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Administration of nebulized ketamine via BAN can be used as analgesic control for musculoskeletal trauma, as it can be administrated to patients with difficult i.v. access, has a rapid onset of analgesic effects with minimal side effects, and remains opioid-sparing.