Potential barriers to upstream fish passage caused by anthropogenic river modifications: A computer modeling study of emerald shiners ( Notropis atherinoides) in the upper Niagara River

Improperly installed or poorly maintained culverts can pose a serious threat to fish by disrupting their habitat and endangering spawning success. Road culverts that are not designed for fish passage frequently can become obstacles. This can be especially problematic for migratory species, but can lead to fragmentation of resident populations as well. This study evaluated 40 culverts of 29 sites within a 25-km radius from Toledo city, Paraná State, southern Brazil, with respect to their likely effects on movement of the local ichthyofauna. We collected data on the shape and length of culverts, culvert material, waterfall height, water column depth, slope, and estimated flow velocity. Culverts were categorized by level of barrier risk for upstream migration: high, medium, low, and impassable, as well as the type of barrier posed (fall height, depth, length and velocity). Most of culverts analyzed were considered potential barriers to fish movement, with 45% classified as impassible, 45% as high risk, 10% as medium risk, and no culverts as low risk. Brazilian culverts as fishways will require additional monitoring and studies to corroborate the premises proposed in the present study. Road culvert projects that are properly built and maintained will be able to simultaneously improve function of roadways and protect fish populations.

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Modes of Binding of 2′-AMP to RNase T1A Computer Modeling Study

Journal of Biomolecular Structure and Dynamics ◽

10.1080/07391102.1992.10507970 ◽

1992 ◽

Vol 9 (5) ◽

pp. 959-969 ◽

Cited By ~ 2

Author(s):

P. V. Balaji ◽

W. Saenger ◽

V. S.R. Rao

Keyword(s):

Computer Modeling ◽

Modeling Study

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The Importance of Consistent 1/d Scans in Determining Size and Strain by Powder Diffraction Profile Analysis

Advances in X-ray Analysis ◽

10.1154/s0376030800019789 ◽

1989 ◽

Vol 33 ◽

pp. 373-381 ◽

Cited By ~ 1

Author(s):

Y. Zhang ◽

J. H. Stewart ◽

C. R. Hubbard ◽

B. Morosin

Keyword(s):

Crystallite Size ◽

Computer Modeling ◽

Powder Diffraction ◽

Profile Analysis ◽

Reciprocal Space ◽

Polycrystalline Materials ◽

Diffraction Profile ◽

Profile Fitting ◽

Modeling Study

AbstractThis paper reports and discusses the results of a computer modeling study on powder diffraction profile analysis for crystallite size and strain of polycrystalline materials. The results of this computer modeling show that if the spans of diffraction profiles in reciprocal space (1/d) are not carefully chosen, an overestimation on size and an underestimation on strain may result in analysis by both the Warren-Averbach and the Hall-Williamson methods. A general way to eliminate such errors based on profile fitting and regeneration is presented and discussed in this paper.

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