Status of scientific knowledge of North American sturgeon

2016 ◽  
Vol 32 ◽  
pp. 5-10 ◽  
Author(s):  
T. J. Haxton ◽  
K. Sulak ◽  
L. Hildebrand
2007 ◽  
Vol 30 (1) ◽  
pp. 158-167
Author(s):  
Ana Carolina Maciel Vieira ◽  
Mariana Gonzalez Leandro Novaes ◽  
Juliana Da Silva Matos ◽  
Ana Carolina Gelmini Faria ◽  
Deusana Maria da Costa Machado ◽  
...  

Since the calls "cabinets of curiosities", the essence of natural history was consolidating itself with the birth of the museums and the development of the Museums of Natural History. This consolidation was reached through following activities: expeditions, field trips, collection classification works, catalogues of diffusion of scientific knowledge, educativ activities and expositions. The present paper intends to discuss the importance of the museal institutions for the studies of Paleontology; since the museums of Natural History had exerted a pioneering paper in the institutionalization of certain areas of knowledge, as Palaeontology, Anthropology and Experimental Physiology, in Brazil. The Paleontological studies in museums had collaborated in the specialization and modernization of the appearance of "new museum idea". As this new concept the museum is a space of diffusion of scientific knowledge, represented as an object that reflects the identity of the society without an obligator linking with physical constructions. However, the Brazilian museums have been sufficiently obsolete, with problems that involve acquisition and maintenance of collections to production of temporary or permanent exhibitions. When the Brazilian institutions of natural history are analyzed they are not organized on the new museum conception and the digital age as the North American and European ones. Despite the difficulties found by the Museums since its birth as Institution in the 18th century, the contemporary development of Museology and Palaeontology as Science had contributed for the consolidation and institutionalization of both, helping the diffusion of scientific knowledge.


2014 ◽  
Vol 7 (2) ◽  
pp. 263-282 ◽  
Author(s):  
Lama Kabbanji

The general objective of this paper is to explore the scientific knowledge produced on the topic of migration in/from African or Arab countries. More specifically, it attempts to identify how different features of the current international division of scientific labour can be illustrated by an examination of the research conducted on migration in/from African and Arab countries. Two main aspects are explored: the role that Arab and African academic communities play in the production of knowledge on migration; and the research priorities among ‘Western and non-Western’ academics. Articles published between the years 2000 and 2010 in three main journals specialized in migration studies are analysed in order to discuss to a certain extent the setting of a hegemonic scientific agenda on international migration which mainly reflects West European and North American concerns. Two main conclusions are drawn: (1) the quasi-absence of scholars from Arab and African academic institutions in mainstream journals is one of the factors explaining the focus of published research on topics relevant to ‘Western’ societies (mainly the insertion process in European and North American countries); and (2) important dimensions of migration dynamics in Arab and African countries are being neglected.


Copeia ◽  
2016 ◽  
Vol 104 (1) ◽  
pp. 260-266
Author(s):  
Marc A. Chalupnicki ◽  
Dawn E. Dittman

<em>Abstract.</em>—We evaluated the ability of juvenile lake sturgeon <em>Acipenser fulvescens</em> and shortnose sturgeon <em>A. brevirostrum</em> to guide along various configurations of angled bar racks and louvers in a laboratory flume. Young-of-the-year (YOY) lake sturgeon were evaluated with the guidance arrays angled at 45 and 15 degrees to the approach flow, and age-1 lake and shortnose sturgeon were evaluated only with the guidance structures set at a 15 degree angle. The YOY lake sturgeon, also, were evaluated with a perpendicular bar rack and with no guidance structure in place. We estimated guidance efficiency at three approach velocities (0.3, 0.6, and 0.9 m/s) by determining the percentage of released fish that were diverted to a full-depth bypass. Guidance efficiency of YOY lake sturgeon was low (<37%) for all bar rack and louver configurations evaluated. The highest guidance efficiencies for YOY lake sturgeon occurred at an approach velocity of 0.3 m/s, and the lowest guidance levels were observed at 0.9 m/s. All YOY lake sturgeon were entrained (i.e., 0% guidance) during tests with the perpendicular bar rack and with no guidance structure in place. There was little difference in YOY lake sturgeon guidance efficiency rates among the various configurations of angled bar racks and louvers that were evaluated with respect to slat spacing, structure angle, and the presence or absence of a solid overlay on the bottom 30 cm of the guidance structures angled at 15 degrees to the approach flow. Guidance efficiencies for age-1 lake and shortnose sturgeon were high, exceeding 90% at all velocities, during tests of the 15-degree bar racks and louvers with the solid bottom overlay installed. The lowest shortnose sturgeon guidance efficiency (83.3%) occurred during the evaluation of the louver without the overlay in place at a velocity of 0.6 m/s. The large difference in guidance rates between the YOY lake sturgeon and the age-1 lake and shortnose sturgeon was most likely due to swimming capabilities associated with fish size. Based on the sizes of the fish we evaluated, the use of angled bar racks and louvers may not be appropriate for sturgeons less than about 200 mm in length, whereas they may be viable guidance technologies for larger fish.


1974 ◽  
Vol 60 (3) ◽  
pp. 548 ◽  
Author(s):  
G. L. Hoffman ◽  
E. V. Raikova ◽  
W. G. Yoder

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