Yellow-flag iris (Iris pseudacorus L.) is a nonnative, invasive wetland plant that disrupts riparian ecosystem processes and is widely distributed across the United States and Canada. Due to its ...physiological and morphological characteristics, I. pseudacorus has the capacity to exclude native vegetation and form extensive monocultures in both lotic and lentic wetland systems. Methods commonly used to manage I. pseudacorus include manual (e.g., hand pulling, digging) and mechanical (e.g., mowing) treatments for small populations and herbicide applications for larger populations; however, herbicide applications near water may be prohibited due to label restrictions. The objective of this research was to evaluate cattle trampling as a nonchemical method to reduce I. pseudacorus in riparian habitats. A greenhouse study was conducted to investigate the effects of inundation and two different timings of simulated trampling on I. pseudacorus density, height, and soluble sugar concentrations in the rhizomes. A complementary field demonstration was established on a ranch in northwestern Nebraska to evaluate cattle trampling effects on I. pseudacorus density and height after two consecutive years. Simulated cattle trampling in the greenhouse had no effect on I. pseudacorus density or height of non-inundated samples. However, combining trampling with inundation reduced I. pseudacorus density from a median of 10 I. pseudacorus per pot to 0 I. pseudacorus per pot and median height from 0.35 m to 0 m by the conclusion of the study. Additionally, the field demonstration resulted in reductions of both density and height of I. pseudacorus after two consecutive years (72% and 67% reduction, respectively). Soluble sugar concentrations were not impacted by any treatment.
Background
Ewing sarcoma of the thoracic spine and chest wall is frequently treated with concurrent chemotherapy and radiation therapy (RT). Treatment‐related acute esophagitis can lead to ...hospitalization and treatment delays. The aim of this study was to analyze the incidence, risk factors, and management of esophagitis in pediatric patients with Ewing sarcoma of the thoracic region.
Methods
We conducted a single‐institution retrospective review of patients treated over a 10‐year period. Medical records were reviewed for patient and treatment characteristics associated with Common Terminology Criteria for Adverse Events grade 2 or higher esophagitis. RT plans were also reviewed and various esophageal dose metrics were analyzed.
Results
Twelve of 37 patients (32%) developed acute esophagitis. Neutropenia was associated with an increased risk of esophagitis (60% vs. 14%; P < 0.01). RT significantly contributed to its incidence when maximum esophageal dose was >47 Gy (69% vs. 5%; P < 0.0001) and esophageal D5cm3 was >15 Gy (67% vs. 9%; P < 0.001). All 12 patients with esophagitis were managed with oral opioid analgesics. Nine patients with persistent symptoms received subsequent fluconazole for empiric fungal treatment and each had a decreased need for opioid analgesics within 2–5 days.
Conclusion
Approximately one‐third of patients with Ewing sarcoma of the thoracic region will develop acute esophagitis. An esophageal D5cm3 dose < 15 Gy and maximal esophageal dose < 47 Gy may keep the rate of acute esophagitis under 5%. However, the association with neutropenia and consistent response to antifungal therapy suggest chemotherapy‐associated toxicity and an infectious component as part of the process.
Grass dominated systems account for ~40% of the earth’s terrestrial surface and typically occur in semi-arid and arid regions. The plant species that grow in these systems are known for their ability ...to withstand disturbance, including drought, grazing, and fire. While it is understood that the plants in these systems often experience multiple forms of stress in a growing season, interactions among these stress variables are not well represented in the literature.In this research, I sought to determine how combinations of stress variables influence the shortgrass steppe, this includes: long-term grazing, drought, erosion, and temperature. Specifically, I examined (1) how the interaction of long-term grazing and drought influences the recovery of the vegetation on the SGS following single-year and multi-year droughts, (2) how the interaction of grazing and erosion influence mortality following exposure to extreme surface temperatures, and (3) performed a comparative analysis of the microclimate of grass dominated systems in the United States to determine the intensity and frequency of stressful abiotic conditions that the vegetation experiences.First, I quantified the interactive effects of single and multi-year droughts with grazing pressure, because the Bouteloua species that dominate the region have been shown to be tolerant of grazing and drought independently, but the interactive effects of the two have not been well studied. Past research has focused on heavy cattle grazing but I included a mixture of moderate cattle grazing with prairie dogs, which is more intensive grazing than heavy cattle grazing. I found that the combined stress of multiple years of drought along with high grazing pressure has the potential to increase mortality in these Bouteloua species.Next, I quantified the erosion severity by ranking the amount crown exposure of the Bouteloua species during a drought on the SGS and then determined how erosion influenced bud outgrowth (production of a tiller) during the recovery year. I combined these data with environmental data collected by the National Ecological Organization Network (NEON) to determine the environmental conditions that the meristems of the plants experienced during the drought. My results showed that the temperatures at the surface of the soil, and exposed meristems, frequently reached levels thought to be lethal to plant cells. I acknowledge that it was likely a combination of water deficit and temperature that led to mortality of Bouteloua species that experienced erosion, but the high temperatures alone had the capacity to cause mortality of the meristems.Finally, I compared several near surface micrometeorological variables of grass dominated systems across the United States. Ultimately, I wanted to determine the frequency that these systems experienced temperatures near the surface that would be damaging to plants, if conventional methods for determining heatwaves represents damaging conditions to grassland plants, and what environmental factors lead to potentially damaging surface temperatures. I found that damaging temperatures occur often at arid sites, conventional heatwaves overestimate heat stress in sites that are wet or at higher latitudes, and underestimates heat stress for arid sites.
Pediatric lung cancer is a very rare occurrence, particularly as a primary lesion. A concurrent diagnosis is even more unusual and only reported a handful of times in Ewing sarcoma. Our patient is a ...13-year-old boy who had concurrent diagnoses of Ewing sarcoma and minimally invasive adenocarcinoma of the lung, formerly bronchoalveolar carcinoma. To our knowledge this has also been found in at least 1 other case. There are some classic genetic mutations associated with Ewing sarcoma. None have been found to be linked with the concurrent diagnosis. A biological linkage is worth considering.
Since the original description of pathogenic germline DICER1 variation underlying pleuropulmonary blastoma (PPB), the spectrum of extrapulmonary neoplasms known to be associated with DICER1 has ...continued to expand and now includes tumors of the ovary, thyroid, kidney, eye, and brain among other sites. This report documents our experience with another manifestation: a primitive sarcoma that resembles PPB and DICER1-associated sarcoma of the kidney. These tumors are distinguished by their unusual location in the peritoneal cavity, associated with visceral and/or parietal mesothelium. A total of seven cases were identified through pathology review in children presenting at a median age of 13 years (range 3-14 years). Primary sites of origin included the fallopian tube (four cases), serosal surface of the colon (one case), and pelvic sidewall (two cases). One case had pathologic features of type I PPB, another type Ir (regressed) PPB, and the remaining five had features of type II or III PPB with a mixed primitive sarcomatous pattern with or without cystic elements. All had a pathogenic DICER1 variation identified in germline and/or tumor DNA. PPB-like peritoneal tumors represent a newly described manifestation of DICER1 pathogenic variation whose pathologic features are also recapitulated in DICER1-related renal sarcoma, cervical embryonal rhabdomyosarcoma, and some Sertoli-Leydig cell tumors with heterologous elements. Tumors arising from the fallopian tube or elsewhere in the abdomen/pelvis, especially those with heterogeneous rhabdomyosarcomatous and/or cartilaginous differentiation, should prompt consideration of germline and tumor DICER1 testing.
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