scholarly journals Timing, location and population characteristics of spawning Montana arctic grayling (Thymallus articus montanus (Milner)) in the Big Hole River drainage, 1989 / by Bradley B. Shepard and Richard A. Oswald.

1990 ◽  
Author(s):  
Bradley B. Shepard ◽  
Richard A. Oswald ◽  
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Keyword(s):  
Population Characteristics ◽  
River Drainage ◽  
Arctic Grayling

Paddlefish Management, Propagation, and Conservation in the 21st Century

2009 ◽  
Keyword(s):  
Mississippi River ◽  
Entire Range ◽  
Population Characteristics ◽  
Ohio River ◽  
River Drainage ◽  
Temporal And Spatial Variability ◽  
Class Strength ◽  
Catch Rates ◽  
Future Work ◽  
River Drainages

<em>Abstract.</em>—The paddlefish <em>Polyodon spathula </em>occurs in the Mississippi and Ohio River drainages, as well as in several Gulf of Mexico tributaries. Populations throughout the Mississippi and Ohio River drainages have been relatively well studied, often relative to their exploitation. In contrast, the genetically distinct Alabama River drainage population has been studied relatively little. Here, we use both historical work and our own research conducted since 1992 to summarize population characteristics of the Alabama River paddlefish population and compare them to other stocks. We also examine the influence of flow on catch rates in the upstream reaches of this drainage during 1998–2003 and suggest where future work is needed to conserve this unique stock. Spawning temperatures and age at maturity were similar between Alabama and Mississippi river populations, and flow and adult paddlefi sh catch rates were positively related, suggesting that year-class strength may be related to flow, as has been shown for other populations. However, Alabama River paddlefish can spawn more frequently, grow faster, and have a much shorter life span. Previous work suggested that paddlefish throughout the Alabama River drainage were genetically distinct from other stocks, and recent work suggests that differences may exist between fish from the upper Alabama River and lower Alabama River. We argue that additional work with Alabama River drainage populations should focus on three areas: (1) detailed genetic work to identify differences among areas within the Alabama River drainage, as well as with other drainages; (2) quantify temporal and spatial variability in population characteristics of paddlefish throughout the entire range of the Alabama River drainage; and (3) quantify year-class strength and correlate it with flow/discharge to eventually predict recruitment and year-class strength in this unique stock.

Retrospective Diagnosis of Pontocerebellar Hypoplasia Type 1B in a Family with Two Deceased Newborn Children

2020 ◽  
Author(s):  
Irena Bradinova ◽  
Silvia Andonova ◽  
Alexey Savov
Keyword(s):  
Clinical Signs ◽  
Final Diagnosis ◽  
Population Based ◽  
Neuromuscular Disorder ◽  
Population Characteristics ◽  
High Risk Population ◽  
Pontocerebellar Hypoplasia ◽  
Clinical Genetic ◽  
Retrospective Diagnosis ◽  
Newborn Children

AbstractPontocerebellar hypoplasia type 1B is a severe autosomal recessive neurologic disorder characterized by a combination of cerebellar and spinal motor neuron degeneration beginning at birth. Pontocerebellar hypoplasia type 1B is caused by mutations in EXOSC3 gene. High prevalence of the p.Gly31Ala mutation was found recently, especially in the Roma ethnic minority. We present a young Bulgarian Roma family with two deceased newborn children manifesting severe neuromuscular disorder including severe muscle weakness, respiratory distress, and multiple joint contractures. Based on the clinical signs and family's population characteristics, DNA testing for the previously described EXOSC3 in Bulgarian Roma mutation c.92G > C; p.Gly31Ala was performed on blood samples of both parents and they were found to be heterozygous carriers. This finding indirectly confirmed the diagnosis of pontocerebellar hypoplasia type B in the deceased offspring. Knowledge of population-specific molecular bases of genetic conditions was the key to final diagnosis in the presented family. Designing of population-based clinical-genetic panels may be a powerful diagnostic tool for patients with such origin. Preconception carrier screening in high-risk population groups is a feasible option to discuss.

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