Archaeological sites in Grand Canyon National Park along the Colorado River are eroding owing to six decades of Glen Canyon Dam operations.

The archaeological record documenting human history in deserts is commonly concentrated along rivers in terraces or other landforms built by river sediment deposits. Today that record is at risk in many river valleys owing to human resource and infrastructure development activities, including the construction and operation of dams. We assessed the effects of the operations of Glen Canyon Dam - which, since its closure in 1963, has imposed drastic changes to flow, sediment supply and distribution, and riparian vegetation - on a population of 362 archaeological sites in the Colorado River corridor through Grand Canyon National Park, Arizona, USA. We leverage 50 years of evidence from aerial photographs and more than 30 years of field observations and measurements of archaeological-site topography and wind patterns to evaluate changes in the physical integrity of archaeological sites using two geomorphology-based site classification systems. We find that most archaeological sites are eroding; moreover, most are at increased risk of continuing to erode, due to six decades of operations of Glen Canyon Dam. Results show that the wind-driven (aeolian) supply of river-sourced sand, essential for covering archaeological sites and protecting them from erosion, has decreased for most sites since 1973 owing to effects of long-term dam operations on river sediment supply and riparian vegetation expansion on sandbars. Results show that the proportion of sites affected by erosion from gullies controlled by the local base-level of the Colorado River has increased since 2000. These changes to landscape processes affecting archaeological site integrity limit the ability of the National Park Service and Grand Canyon-affiliated Native American Tribes to achieve environmental management goals to maintain or improve site integrity in situ. We identify three environmental management opportunities that could be used to a greater extent to decrease the risk of erosion and increase the potential for in-situ preservation of archaeological sites. Environmental management opportunities are: 1) sediment-rich controlled river floods to increase the aeolian supply of river-sourced sand, 2) extended periods of low river flow to increase the aeolian supply of river-sourced sand, 3) the removal of riparian vegetation barriers to the aeolian transport of river-sourced sand.

Methotrexate treatment for peritoneal trophoblastic implants after laparoscopic salpingectomy and secondary laparoscopic excision of ectopic pregnancy.

Ectopic pregnancy is a one of the primary causes of maternal mortality in first trimester. The most common site of ectopic pregnancy is the fallopian tube. Surgical management of tubal ectopic pregnancy includes salpingotomy or salpingectomy. Persistent ectopic pregnancy can happen after salpingotomy due to incomplete removal of ectopic tissue. However, it is very rare after salpingectomy. In our case, the patient had right-sided salpingectomy and histology confirmed right-sided tubal ectopic pregnancy. She presented 19 days' later with abdominal pain, haemoperitoneum and persistent high beta-HCG (B-HCG). A second laparoscopy was done and tissue implants were removed from the surface of the right ovary and the omentum, which were confirmed to be products of conception on histology. The pain settled postoperative. However, B-HCG remained high postoperative. Subsequently, methotrexate treatment was given leading to full resolution of the pregnancy with one dose.