The Effects Of Beaver Impoundments On Montane Stream Fish Communites

North American beavers (Castor canadensis) are ecological engineers, and their dams alter stream environments. Few studies have examined the effect of beaver dams on Southern Appalachian fishes. I sampled fish communities from 9 streams with active beaver ponds and 7 with inactive beaver ponds. Sediment was taken from all ponds to quantify the abundance of oligochaete worms, potential hosts for the fish parasite Myxobolus cerebralis. I found that both active and inactive beaver impoundments affect water quality, fish communities, and oligochaete prevalence. Generalized linear mixed effect models (GLMMs) indicate reduced fish diversity in streams with active impoundments. The magnitude of this reduction depends on the proximity to an impoundment. Models indicate that site elevation plays the strongest role in determining fish species richness. Active ponds also had lower dissolved oxygen and temperatures. Indicator species analysis found two species associated with active beaver ponds and 8 associated with inactive ponds or unimpounded reaches. Oligochaetes were more prevalent in active ponds, but I detected no abnormal salmonids. My work indicates that Appalachian Mountain streams with active ponds support less diverse fish assemblages than those with inactive ponds. Beaver ponds improve habitat for oligochaetes but their role in fish disease transmission remains unclear

The Melanostomini of the Neotropical region (Diptera, Syrphidae). American Museum novitates ; no. 1272

29 p. : ill. ; 24 cm.Includes bibliographical references

Chemotherapy Is Associated With Improved Survival in Adult Patients With Primary Extremity Synovial Sarcoma

Two prospectively collected sarcoma databases were used to analyze the impact of ifosfamide-based chemotherapy on the survival of patients with high-risk primary extremity synovial sarcoma. Ifosfamide-based chemotherapy was associated with an improved survival compared with patients that received no chemotherapy

The Permafrost Young Researchers Network (PYRN) is getting older: The past, present, and future of our evolving community

International audienceA lasting legacy of the International Polar Year (IPY) 2007–2008 was the promotion of the Permafrost Young Researchers Network (PYRN), initially an IPY outreach and education activity by the International Permafrost Association (IPA). With the momentum of IPY, PYRN developed into a thriving network that still connects young permafrost scientists, engineers, and researchers from other disciplines. This research note summarises (1) PYRN’s development since 2005 and the IPY’s role, (2) the first 2015 PYRN census and survey results, and (3) PYRN’s future plans to improve international and interdisciplinary exchange between young researchers. The review concludes that PYRN is an established network within the polar research community that has continually developed since 2005. PYRN’s successful activities were largely fostered by IPY. With >200 of the 1200 registered members active and engaged, PYRN is capitalising on the availability of social media tools and rising to meet environmental challenges while maintaining its role as a successful network honouring the legacy of IPY