Montreal Biodome

Most falls occur while walking, making gait quality a logical therapeutic target. Many temporo-spatial variables have been implicated in increased fall risk, but these are dependent upon kinematic parameters of the joints involved in the gait cycle. The widespread availability of wearable sensors has made the acquisition of kinematic data feasible, and those related to the ankle are most relevant, as they relate most closely to causes of falls, trips, slips, and mis-steps. The purpose of this study is to estimate the extent to which measures of ankle angular velocity (AV) during walking are associated with falls. This is a comparative study of ankle AV metrics between people who have or have not experienced a fall in the past year. Data came from experimental use of the Heel2Toe™ sensor in a variety of settings, including demonstrations and clinical research studies. The sample comprised 387 participants, of whom 68 (17.6%) self-reported falling in the past year. Logistic regression with a natural cubic spline with 3 degrees of freedom identified AV of the angle at heel strike to discriminate between fallers and non-fallers, and the regression parameters were used to propose an algorithm to estimate fall risk. Applying the algorithm to the existing data yielded a range of probabilities from 0.0480 to 0.7245 depending on age of the person assessed. Further testing of this algorithm in different samples is warranted.

Gill neoplasia in fish is rare but has been reported in multiple elasmobranch and teleost species. Although more commonly a site of metastatic disease, primary neoplasms of the gill may occur, and both spontaneous and chemically induced tumors have been reported. Here we describe a spontaneous branchioblastoma in a koi carp (Cyprinus rubrofuscus) with no known history of chemical exposure. A soft-tissue mass on the inner surface of the dorsal opercular chamber appeared to originate from either a gill arch or a pseudobranch. Histologically, the mass was comprised of 3 well-differentiated cell types: blastemal cells, epithelial cells arranged in a lamellar fashion, and islands of cartilage resembling those present in gill filaments. To our knowledge, this is only the fourth case of spontaneous branchioblastoma recorded in koi.

The evolution and diversification of ancient megathermal angiosperm lineages with Africa-India origins in Asian tropical forests is poorly understood because of the lack of reliable fossils. Our palaeobiogeographical analysis of pollen fossils from Africa and India combined with molecular data and fossil amber records suggest a tropical-African origin of Dipterocarpaceae during the mid-Cretaceous and its dispersal to India during the Late Maastrichtian and Paleocene, leading to range expansion of aseasonal dipterocarps on the Indian Plate. The India-Asia collision further facilitated the dispersal of dipterocarps from India to similar climatic zones in Southeast Asia, which supports their out-of-India migration. The dispersal pathway suggested for Dipterocarpaceae may provide a framework for an alternative biogeographic hypothesis for several megathermal angiosperm families that are presently widely distributed in Southeast Asia.

The Atlantic wolffish (AW) and the spotted wolffish (SW) are long-lived fish found in the North Atlantic and Arctic oceans and are respectively classified as special concern and threatened species, mainly due to fisheries bycatch. To better understand health issues associated with the care of these species in public aquaria, reports from all necropsies performed in 2 zoological institutions between 2009 and 2019 were reviewed (31 AW and 8 SW). These wolffish were fed with a similar fish-based diet and kept in multi-species exhibits with comparable environmental parameters. The most frequent necropsy findings were the presence of xanthomas (AW: 41.9%; SW: 75.0%), nephrocalcinosis (AW: 42.9%; SW: 75.0%) and urocystoliths (AW: 6.5%; SW: 62.5%). Xanthomas were mostly located at the base of pectoral fins and were characterized by extensive granulomatous inflammation centered on accumulations of partly mineralized degenerate fatty material, mainly composed of cholesterol crystals. Nephrocalcinosis was characterized by the deposition of calcium salts within the renal tubules and was commonly associated with tubular necrosis. The aquarium-housed wolffish were fed a coldwater fish-based diet. However, the natural diet of wolffish is composed mostly of invertebrates such as urchins and crustaceans. Differences in nutrient composition between these diets, such as lipid and mineral content, may have contributed to the development of xanthomatosis, nephrocalcinosis and urocystolithiasis in wolffish housed in these institutions.

Abstract Comparing ecologically relevant communities of insects in heterogeneous environments requires methods capable of sampling a sufficient number of individuals and diversity of species to measure β diversity. A battery‐operated computer fan powers a 1.5 m high Voegtlin suction trap. These traps are efficient at capturing small, weakly flying insects, and can be used to sample the α and β diversity of Microhymenoptera in discrete habitats within a temperate forest ecosystem. During a preliminary study comparing Voegtlin‐style suction and Townes‐style Malaise traps, we found that the suction traps caught a greater number and a greater diversity of Hymenoptera than the Malaise traps, especially of those OTUs smaller than 1.5 mm. Placed along a transect at 50 m intervals, the suction traps also yielded more heterogeneous samples than the Malaise traps, suggesting they may be particularly useful for quantifying β diversity at small spatial scales. The same analyses with brachyceran Diptera were more nuanced. Malaise traps outperformed suction traps in terms of measuring α diversity, but suction traps resolved a higher degree of brachyceran community heterogeneity using β diversity. Insofar as Hymenoptera are amongst the most diverse of insect orders and the vast majority of species are specialist parasitoids of other insects, suction trapped Hymenoptera diversity may be a useful proxy for measuring α and β insect diversity in general.

ABSTRACTHybridization between closely related species can generate genetic and phenotypic variation, providing valuable biological material to assess the physiological impact of the structural or functional variability of different organs. In the present study, we examined growth rates of various organs and whole body in brook char, Arctic char and their reciprocal hybrids over a period of 281 days. Parental species achieved significantly higher body mass than their hybrids. Hybridization significantly reduced the relative size of the heart, liver and spleen. The relative size of pyloric caeca did not differ among the four groups. The observed lower growth performance of the hybrids compared to parental species strongly suggests that divergence in the relative size of digestive organs, liver and heart partly dictate growth capacity. Our results also suggest that the increased variability achieved through hybridization may prove useful in a genetic selection program.

Environmental temperature influences rates of embryonic development, but a detailed staging series for vertebrate embryos developing in the subzero cold of Antarctic waters is not yet available from fertilization to hatching. Given projected warming of the Southern Ocean, it is imperative to establish a baseline to evaluate potential effects of changing climate on fish developmental dynamics. We studied the Bullhead notothen (Notothenia coriiceps), a notothenioid fish inhabiting waters between -1.9 and +2 °C. In vitro fertilization produced embryos that progressed through cleavage, epiboly, gastrulation, segmentation, organogenesis, and hatching. We compared morphogenesis spatially and temporally to Zebrafish and medaka. Experimental animals hatched after about 6 months to early larval stages. To help understand skeletogenesis, we analyzed late embryos for expression of sox9 and runx2, which regulate chondrogenesis, osteogenesis, and eye development. Results revealed that, despite their prolonged developmental time course, N. coriiceps embryos developed similarly to those of other teleosts with large yolk cells. Our studies set the stage for future molecular analyses of development in these extremophile fish. Results provide a foundation for understanding the impact of ocean warming on embryonic development and larval recruitment of notothenioid fish, which are key factors in the marine trophic system. Developmental Dynamics 245:1066-1080, 2016. © 2016 Wiley Periodicals, Inc.

Pressures on the Brazilian Amazon forest have been accentuated by agricultural activities practiced by families encouraged to settle in this region in the 1970s by the colonization program of the government. The aims of this study were to analyze the temporal and spatial evolution of land cover and land use (LCLU) in the lower Tapajós region, in the state of Pará. We contrast 11 watersheds that are generally representative of the colonization dynamics in the region. For this purpose, Landsat satellite images from three different years, 1986, 2001, and 2009, were analyzed with Geographic Information Systems. Individual images were subject to an unsupervised classification using the Maximum Likelihood Classification algorithm available on GRASS. The classes retained for the representation of LCLU in this study were: (1) slightly altered old-growth forest, (2) succession forest, (3) crop land and pasture, and (4) bare soil. The analysis and observation of general trends in eleven watersheds shows that LCLU is changing very rapidly. The average deforestation of old-growth forest in all the watersheds was estimated at more than 30% for the period of 1986 to 2009. The local-scale analysis of watersheds reveals the complexity of LCLU, notably in relation to large changes in the temporal and spatial evolution of watersheds. Proximity to the sprawling city of Itaituba is related to the highest rate of deforestation in two watersheds. The opening of roads such as the Transamazonian highway is associated to the second highest rate of deforestation in three watersheds.

The ‘earthy’ and ‘muddy’ off-flavours in pond-reared fish are due to the presence of geosmin or 2-methylisoborneol in the flesh of the fish. Similar off-flavours have been reported in fish raised in recirculating aquaculture systems (RAS); however, little information is available regarding the cause of these off-flavours. Our hypothesis was that earthy and muddy off-flavour compounds, found previously in pond-raised fish, are also responsible for off-flavours in fish raised in RAS. In this preliminary study, we examined water, biofilms in RAS and fillets from cultured arctic charr known to have off-flavours and requiring depuration using instrumental [solid-phase microextraction procedure and gas chromatograph-mass spectrometry (GC-MS)] and human sensory analyses. Geosmin was present in the samples taken from the biofilter and on the side walls of the tanks. Two-methylisoborneol was only found in low levels in the samples. The GC-MS results indicated the presence of geosmin in the fillets (705 ng kg−1), but lower levels were found in the water (30.5 ng L−1). Sensory analyses also detected an earthy flavour (i.e., geosmin presence) in the fillets, and, therefore, it appears that geosmin is the main compound responsible for the off-flavour in RAS. Further studies are being performed to identify the microorganisms responsible for geosmin production in RAS.