scholarly journals Comparative Population Characteristics of Muskellunge (Esox masquinongy), Northern Pike (E. lucius), and Their Hybrid (E. masquinongy × E. lucius)

1993 ◽  
Vol 50 (9) ◽  
pp. 1961-1968 ◽  
Author(s):  
David H. Wahl ◽  
Roy A. Stein
Keyword(s):  
Northern Pike ◽  
Population Characteristics ◽  
Gizzard Shad ◽  
First Year ◽  
Dorosoma Cepedianum ◽  
Esox Masquinongy ◽  
Survival Patterns ◽  
Prey Length ◽  
Better Than ◽  
Comparative Population

We compared growth, survival, diet, and angler catch of muskellunge (Esox masquinongy), northern pike (E. lucius), and tiger muskellunge (E. masquinongy × E. lucius) through 5 yr after their introduction into three Ohio reservoirs. Muskellunge grew slower than northern pike and tiger muskellunge through the first year but faster than northern pike in subsequent years. Large stocked esocids (180–205 mm) survived better than small ones (145 mm). Survival patterns established through the first fall were maintained through age 5; northern pike survived best, followed by muskellunge and tiger muskellunge. Angler catch reflected differences in survival as well as catchability among taxa. Northern pike were caught at smaller sizes and younger ages than other taxa. Gizzard shad (Dorosoma cepedianum) dominated esocid diets for all taxa and age classes, followed by centrarchids and cyprinids. Prey length consumed increased linearly with esocid length; northern pike selected larger gizzard shad than either muskellunge or tiger muskellunge. These differences in population characteristics among esocids should influence mangement and stocking programs. Whereas northern pike maximize angling opportunities, muskellunge probably will provide trophy fisheries. Although tiger muskellunge can be reared inexpensively, they appear to provide little recreational fishing in return.

Effect of detritus quality on growth and survival of gizzard shad (Dorosoma cepedianum): potential importance to benthic–pelagic coupling

2007 ◽  
Vol 64 (12) ◽  
pp. 1805-1815 ◽  
Author(s):  
Gene W Kim ◽  
Alpa P Wintzer ◽  
Trisha K Menker ◽  
Roy A Stein ◽  
John M Dettmers ◽  
...  
Keyword(s):  
Food Webs ◽  
Sediment Quality ◽  
Trophic Levels ◽  
Population Characteristics ◽  
Gizzard Shad ◽  
Dorosoma Cepedianum ◽  
Lake Productivity ◽  
Growth And Survival ◽  
Piscivorous Fish ◽  
Detritus Quality

Gizzard shad (Dorosoma cepedianum) population characteristics vary with lake productivity, competing with and providing prey for sport fishes. Because age-0 gizzard shad (>30 mm total length) are facultative detritivores, they can link benthic energy, carbon, and nutrients to pelagic food webs. To determine how age-0 gizzard shad success varies along a detritus-quality gradient, we completed a 15-day laboratory experiment in which age-0 gizzard shad fed lake sediment and starved gizzard shad both suffered high mortality, whereas fish fed zooplankton grew and survived well. This suggested that detritus alone is insufficient to ensure gizzard shad growth and survival. When sediment quality was high in outdoor mesocosms, density-dependent factors led to rapid growth only at low fish density and high-quality sediments; however, survival generally increased with sediment quality, regardless of gizzard shad density. In four small reservoirs, annual growth of gizzard shad increased with sediment quality. Collectively, our findings suggest that detritus quality ultimately can contribute to regulation of community and ecosystem productivity, mediated by its influence on gizzard shad biomass available for trophic transfer to gape-limited predators (i.e., piscivorous fish). This role of gizzard shad can link higher trophic levels in aquatic food webs to allochthonous detritus subsidies from the surrounding watershed.

A Cohort study to compare Admission criteria and Academic performance among preclinical students at The Copperbelt University School of Medicine: complete enumeration (Preprint)

2019 ◽  
Author(s):  
Andrew Mwila
Keyword(s):  
Academic Performance ◽  
Cohort Study ◽  
Clinical Medicine ◽  
Average Score ◽  
First Year ◽  
Admission Criteria ◽  
Biomedical Sciences ◽  
Dental Surgery ◽  
School Of Medicine ◽  
Better Than

BACKGROUND The Copperbelt University is the second public University in Zambia. The School of Medicine has four major programs namely; Bachelor of Medicine and Surgery, Bachelor of Dental Surgery, Bachelor of Clinical Medicine and Bachelor of Biomedical sciences. The Copperbelt University School of Medicine runs a five-year training program for both the BDS and the MBCHB programs. Students are admitted into the Medical school after successfully completing their first year at the Main campus in the School of Natural Sciences with an average of 4 B grades or higher (B grade is a mark of 65 to 74%). OBJECTIVE The study was done to determine the association between admission criteria and academic performance among preclinical students. Hence, the study compares the academic performance among preclinical students admitted into the Bachelor of Dental Surgery and Bachelor of Medicine and Surgery at the Copperbelt University School of Medicine. METHODS This is a retrospective cohort study conducted at Michael Chilufya Sata School of medicine Campus. A pilot study was conducted with 30 BDS and 30 MBCHB students and the obtained information helped determine the sample size. SPSS was used to analyze the data. The study period lasted approximately 7 weeks at a cost of K1621. RESULTS In 2014, there was an improvement in average performance between 2nd and 3rd year for each program. An average score of 15.4 (SD 4.2) was obtained in 3rd year compared to 12.8 (SD 4.9) in 2nd year (p<0.001). Meanwhile, 3rd MB ChB mean score was 12.6 (SD 3.7) compared to 10.7 (SD 3.6) in 2nd years (p<0.05). However, in 2016, both programs, 3rd year mean scores were lower than 2nd year (MB ChB 2nd year mean score was 12.0 (SD 4.3) compared to 3rd year with a mean score of 9.5 (SD 4.5), p<0.001; BDS 2nd year mean score was 10.6 (SD 4.0) compared to 3rd year mean score of 8.2 (SD 3.4), p<0.01. On average MB ChB students performed better than BDS students in all the years (p<0.05), except in 2016 when the results were comparable. CONCLUSIONS Results from the study shows that entry criteria has a correlation to academic performance as students admitted with higher grades perform much better than those with lower grades.

scholarly journals Deep learning for intelligent diagnosis in thyroid scintigraphy

2021 ◽  
Vol 49 (1) ◽  
pp. 030006052098284
Author(s):  
Tingting Qiao ◽  
Simin Liu ◽  
Zhijun Cui ◽  
Xiaqing Yu ◽  
Haidong Cai ◽  
...  
Keyword(s):  
Deep Learning ◽  
Disease Diagnosis ◽  
Kappa Coefficient ◽  
Diagnostic Assessment ◽  
First Year ◽  
Thyroid Scintigraphy ◽  
Diagnostic Ability ◽  
The Third ◽  
Classification Time ◽  
Better Than

Objective To construct deep learning (DL) models to improve the accuracy and efficiency of thyroid disease diagnosis by thyroid scintigraphy. Methods We constructed DL models with AlexNet, VGGNet, and ResNet. The models were trained separately with transfer learning. We measured each model’s performance with six indicators: recall, precision, negative predictive value (NPV), specificity, accuracy, and F1-score. We also compared the diagnostic performances of first- and third-year nuclear medicine (NM) residents with assistance from the best-performing DL-based model. The Kappa coefficient and average classification time of each model were compared with those of two NM residents. Results The recall, precision, NPV, specificity, accuracy, and F1-score of the three models ranged from 73.33% to 97.00%. The Kappa coefficient of all three models was >0.710. All models performed better than the first-year NM resident but not as well as the third-year NM resident in terms of diagnostic ability. However, the ResNet model provided “diagnostic assistance” to the NM residents. The models provided results at speeds 400 to 600 times faster than the NM residents. Conclusion DL-based models perform well in diagnostic assessment by thyroid scintigraphy. These models may serve as tools for NM residents in the diagnosis of Graves’ disease and subacute thyroiditis.

scholarly journals An analysis of Italian university students’ performance through segmented regression models: gender differences in STEM courses

Genus ◽  
2021 ◽  
Vol 77 (1) ◽  
Author(s):  
Andrea Priulla ◽  
Nicoletta D’Angelo ◽  
Massimo Attanasio
Keyword(s):  
Gender Differences ◽  
Regression Models ◽  
First Year ◽  
Strongly Correlated ◽  
Segmented Regression ◽  
Freshmen Students ◽  
Female Performance ◽  
And Mathematics ◽  
The Relationship ◽  
Better Than

AbstractThis paper investigates gender differences in university performances in Science, Technology, Engineering and Mathematics (STEM) courses in Italy, proposing a novel application through the segmented regression models. The analysis concerns freshmen students enrolled at a 3-year STEM degree in Italian universities in the last decade, with a focus on the relationship between the number of university credits earned during the first year (a good predictor of the regularity of the career) and the probability of getting the bachelor degree within 4 years. Data is provided by the Italian Ministry of University and Research (MIUR). Our analysis confirms that first-year performance is strongly correlated to obtaining a degree within 4 years. Furthermore, our findings show that gender differences vary among STEM courses, in accordance with the care-oriented and technical-oriented dichotomy. Males outperform females in mathematics, physics, chemistry and computer science, while females are slightly better than males in biology. In engineering, female performance seems to follow the male stream. Finally, accounting for other important covariates regarding students, we point out the importance of high school background and students’ demographic characteristics.

Improvements in water quality following biomanipulation of gizzard shad (Dorosoma cepedianum) in Lake Denham, Florida

2011 ◽  
Vol 27 (4) ◽  
pp. 287-297 ◽  
Author(s):  
Walt Godwin ◽  
Michael Coveney ◽  
Edgar Lowe ◽  
Lawrence Battoe
Keyword(s):  
Water Quality ◽  
Gizzard Shad ◽  
Dorosoma Cepedianum

Comparative urogenital morphology and external sex determination in muskellunge, Esox masquinongy Mitchill

1989 ◽  
Vol 67 (4) ◽  
pp. 1053-1060 ◽  
Author(s):  
Bernard Lebeau ◽  
Gérard Pageau
Keyword(s):  
Ventral Surface ◽  
Northern Pike ◽  
Structural Basis ◽  
Simple Method ◽  
Esox Masquinongy ◽  
Secondary Sexual Characteristics ◽  
Sexual Characteristics ◽  
Spawning Behaviour ◽  
Accurate Indicator ◽  
Secondary Sexual

Primary and secondary sexual characteristics in northern pike, Esox lucius Linneaus, and muskellunge, Esox masquinongy Mitchill, differ markedly. Differences in the internal urogenital anatomy include the structure of the genital ducts and the angle they form with the ventral surface. Externally, the genital and urinary ducts open directly to the environment in northern pike, whereas in muskellunge they open into a muscular papilla and then through a urogenital pore. Differences in sexual dimorphism between the two closely related esocids constitute a structural basis to explain the known differences in spawning behaviour and reproductive success. Differences in secondary sexual characteristics explain why the methods developed by Demchenko or Casselman to externally sex pike are inapplicable to muskellunge. To develop and test two external sexing techniques for muskellunge, specimens were collected from two regions in Canada from 1980 to 1987. Examination of reproductive products obtained from stripping provided an accurate indicator of sex and sexual maturity, but demonstrated serious limitations. A simple method to sex muskellunge by examination of the external urogenital morphology is described for juveniles and adults. Dissection of fish revealed that with the urogenital examination technique we sexed juveniles with a success rate of 92–98%, and adults with 100% accuracy.

Reflecting materials in the eyes of three teleosts, Orthopristes chrysopterus, Dorosoma cepedianum and Anchoa mitchilli

1973 ◽  
Vol 184 (1074) ◽  
pp. 15-27 ◽  
Keyword(s):  
Body Length ◽  
Pigment Epithelium ◽  
Total Body Length ◽  
Gizzard Shad ◽  
Dorosoma Cepedianum ◽  
Anchoa Mitchilli ◽  
First Report ◽  
Total Body ◽  
Bay Anchovy

The tapeta lucida of three species of teleosts were examined to determine the composition of the reflecting material. The fishes were bay anchovy Anchoa mitchilli (Engraulidae), gizzard shad Dorosoma cepedianum (Clupeidae) and pigfish Orthopristes chrysopterus (Haemulidae). The tapetum of each species was situated in the pigment epithelium of the eye. That of the pigfish contained triglycerides identified as chiefly glyceryl tridocosahexaenoate. A reduced pteridine, 7, 8-dihydroxanthopterin, occurred in the tapetum of the gizzard shad. Guanine occurred in the tapetum of the bay anchovy. The tapetum of the shad contained brightly reflecting particles about 0.5 μm in diameter There were 10.8 mg of dihydroxanthopterin in the tapetum of a shad (total body length 23 cm) and 0.46 mg of guanine in the tapetum of an anchovy (total body length 9 cm). This is the first report of a pteridine acting as a retinal reflector in vertebrates. Various aspects of retinal reflectors of teleosts are discussed and their variety and common characteristics commented upon.

EFFECTS OF INORGANIC NITROGEN AND PHOSPHORUS FERTILIZERS ON SELECTED SITES OF NATIVE GRASSLAND IN WESTERN CANADA

1965 ◽  
Vol 45 (3) ◽  
pp. 229-237 ◽  
Author(s):  
M. R. Kilcher ◽  
S. Smoliak ◽  
W. A. Hubbard ◽  
A. Johnston ◽  
A. T. H. Gross ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Total Yield ◽  
First Year ◽  
Western Canada ◽  
Phosphorus Fertilizer ◽  
Nitrogen And Phosphorus ◽  
Native Grass ◽  
Yield Increase ◽  
Native Grassland ◽  
Better Than

N, P, and N + P at 60, 26, and 60 + 26 lb per acre were applied on native grass sites during three successive years at seven, locations in Western Canada. Single applications of the N fertilizer resulted in 3- or 4-year total yield increases of 300 to 600 lb per acre at six locations. At Summerland the 3-year increase was nearly 1400 lb. Phosphorus fertilizer by itself provided very little yield increase. N + P gave yield increases that were only slightly better than those from N alone.Residual responses to fertilizer were important, especially in the 12- to 16-in. rainfall locations. Only about one-third of the total yield increase occurred in the first year, with the remainder coming in the subsequent seasons.Weeds, where present, showed a marked response to fertilizer N in the first season; in subsequent years the response largely disappeared.

Digestive enzyme and gut surfactant activity of detritivorous gizzard shad (Dorosoma cepedianum)

2000 ◽  
Vol 57 (6) ◽  
pp. 1113-1119 ◽  
Author(s):  
James C Smoot ◽  
Robert H Findlay
Keyword(s):  
Enzyme Activity ◽  
Protease Activity ◽  
Feeding Strategy ◽  
Digestive Enzyme ◽  
Artificial Substrates ◽  
Gizzard Shad ◽  
Dorosoma Cepedianum ◽  
Digestive Physiology ◽  
Protease Enzyme ◽  
Surfactant Activity

Measuring digestive enzyme and surfactant activities tested specialization of gizzard shad (Dorosoma cepedianum) digestive physiology to a detritivorous feeding strategy. Digestive enzyme activity was measured in adult and larval gizzard shad using fluorescently labeled artificial substrates. Surfactant activity in gizzard shad was measured by comparing gut juice drop diameters over a range of dilutions. Enzyme activity in the ceca region of adult gizzard shad was high for esterase, beta-glucosidase, lipase, and protease. Enzyme activity was lower in posterior intestine sections than in anterior intestine sections, although protease activity remained high for the greatest distance in the intestine. Micelles were detected in adult gizzard shad gut juice, and surfactant activity was greatest in the ceca region. Larval gizzard shad protease activity was similar to that of adult fish, and surfactants were below their critical micelle concentration. Gizzard shad coupled digestive physiology with gut anatomy to obtain nutrients from detritus, and these adaptations may explain elevated growth rates observed in these fish when they are planktivorous.

The role of water ventilation and sediment ingestion in the uptake of benzo[A]pyrene in gizzard shad (dorosoma cepedianum)

1996 ◽  
Vol 15 (10) ◽  
pp. 1752-1759 ◽  
Author(s):  
Alan S. Kolok ◽  
James N. Huckins ◽  
Jimmie D. Petty ◽  
James T. Oris
Keyword(s):  
Gizzard Shad ◽  
Dorosoma Cepedianum
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