Lake Titicaca, situated in the Altiplano high plateau, is the only ancient lake in South America. This 2- to 3-My-old (where My is million years) water body has had a complex history that included at least five major hydrological phases during the Pleistocene. It is generally assumed that these physical events helped shape the evolutionary history of the lake's biota. Herein, we study an endemic species assemblage in Lake Titicaca, composed of members of the microgastropod genus Heleobia, to determine whether the lake has functioned as a reservoir of relic species or the site of local diversification, to evaluate congruence of the regional paleohydrology and the evolutionary history of this assemblage, and to assess whether the geographic distributions of endemic lineages are hierarchical. Our phylogenetic analyses indicate that the Titicaca/Altiplano Heleobia fauna (together with few extralimital taxa) forms a species flock. A molecular clock analysis suggests that the most recent common ancestor (MRCAs) of the Altiplano taxa evolved 0.53 (0.28–0.80) My ago and the MRCAs of the Altiplano taxa and their extralimital sister group 0.92 (0.46–1.52) My ago. The endemic species of Lake Titicaca are younger than the lake itself, implying primarily intralacustrine speciation. Moreover, the timing of evolutionary branching events and the ages of two precursors of Lake Titicaca, lakes Cabana and Ballivián, is congruent. Although Lake Titicaca appears to have been the principal site of speciation for the regional Heleobia fauna, the contemporary spatial patterns of endemism have been masked by immigration and/or emigration events of local riverine taxa, which we attribute to the unstable hydrographic history of the Altiplano. Thus, a hierarchical distribution of endemism is not evident, but instead there is a single genetic break between two regional clades. We also discuss our findings in relation to studies of other regional biota and suggest that salinity tolerance was the most likely limiting factor in the evolution of Altiplano species flocks.

This study describes the development, implementation, and psychometric assessment of the multiple mini-interview (MMI) for the inaugural class of veterinary medicine applicants at the University of Calgary Faculty of Veterinary Medicine (UCVM). The MMI is a series of approximately five to 12 10-minute interviews that consist of situational events. Applicants are given a scenario and asked to work through an issue or behavioral-type questions that are meant to assess one attribute (e.g., empathy) at a time. This structure allows for multiple assessments of the applicants by trained interviewers on the same questions. MMI scenario development was based on a review of the noncognitive attributes currently assessed by the 31 veterinary schools across Canada and the United States and the goals and objectives of UCVM. The noncognitive attributes of applicants (N=110) were assessed at five stations, by two interviewers within each station, on three items using a standardized rating form on an anchored 1-5 scale. The method was determined to be reliable (G-coefficient=0.88) and demonstrated evidence of validity. The MMI score did not correlate with grade-point average (r=0.12, p=0.22). While neither the applicants nor interviewers had participated in an MMI format before, both groups reported the process to be acceptable in a post-interview questionnaire. This analysis provides preliminary evidence of the reliability, validity, and acceptability of the MMI in assessing the noncognitive attributes of applicants for veterinary medical school admissions.

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Disease ecology is a relevant but relatively unexplored subject of research in urban coyotes ( Canis latrans Say, 1823). In fact, this carnivore may play a role in the circulation of parasites that can have implications on the health of humans and domestic dogs, but can also be affected by pathogens transmitted from domestic reservoirs. To investigate the gastrointestinal parasites of urban coyotes in Calgary, Alberta, Canada, we analyzed 61 carcasses and 247 fecal samples collected within the metropolitan area, including city parks, in 2009–2010. We found nine parasite taxa: Toxascaris leonina (Linstow, 1902), Uncinaria stenocephala (Railliet, 1884), Ancylostoma caninum (Ercolani, 1859), Pterygodermatites affinis (Jägerskiöld, 1904), Trichuris vulpis (Froelich, 1789), Echinococcus multilocularis Leuckart, 1863, Taenia crassiceps (Zeder, 1800), genus Giardia Kunstler, 1882, and genus Cystoisospora Frenkel, 1977. Factors related to coyote ecology, habitat characteristics, and dog management likely influence the community of coyote parasites in an urban environment, and need to be taken into account to assess the actual role of this carnivore in the maintenance of parasites in the city landscape. Further research is needed to assess the current risk for transmission of potentially zoonotic parasites (e.g., E. multilocularis, T. crassiceps, Giardia sp.) among coyotes, dogs, and humans.

BackgroundOnchocerca cervipedis is a filarioid nematode of cervids reported from Central America to boreal regions of North America. It is found primarily in subcutaneous tissues of the legs, and is more commonly known as ‘legworm’. Blackflies are intermediate hosts and transmit larvae to ungulates when they blood-feed. In this article we report the first records of O. cervipedis from high latitudes of North America and its occurrence in previously unrecognized host subspecies including the Yukon-Alaska moose (Alces americanus gigas) and the Grant’s caribou (Rangifer tarandus granti).MethodsWe examined the subcutaneous connective tissues of the metacarpi and/or metatarsi of 34 moose and one caribou for parasitic lesions. Samples were collected from animals killed by subsistence hunters or animals found dead in the Northwest Territories (NT), Canada and Alaska (AK), USA from 2005 to 2012. Genomic DNA lysate was prepared from nematode fragments collected from two moose. The nd5 region of the mitochondrial DNA was amplified by PCR and sequenced.ResultsSubcutaneous nodules were found in 12 moose from the NT and AK, and one caribou from AK. Nematodes dissected from the lesions were identified as Onchocerca cervipedis based on morphology of female and male specimens. Histopathological findings in moose included cavitating lesions with multifocal granulomatous cellulitis containing intralesional microfilariae and adults, often necrotic and partially mineralized. Lesions in the caribou included periosteitis with chronic cellulitis, eosinophilic and lymphoplasmacytic infiltrate, and abundant granulation associated with intralesional adult nematodes and larvae. Sequences of the nd5 region (471bp), the first generated for this species, were deposited with Genbank (JN580791 and JN580792). Representative voucher specimens were deposited in the archives of the United States National Parasite Collection.ConclusionsThe geographic range of O. cervipedis is broader than previously thought, and extends into subarctic regions of western North America, at least to latitude 66°N. The host range is now recognized to include two additional subspecies: the Yukon-Alaska moose and Grant’s caribou. Accelerated climate change at high latitudes may affect vector dynamics, and consequently the abundance and distribution of O. cervipedis in moose and caribou. Disease outbreaks and mortality events associated with climatic perturbations have been reported for other filarioids, such as Setaria tundra in Fennoscandia, and may become an emerging issue for O. cervipedis in subarctic North America.