scholarly journals Distribution of migratory fish in the stream (depth, velocity, body size, predators)

2019 ◽  
Vol 27 (3) ◽  
pp. 221-226
Author(s):  
A. A. Chemagin
Keyword(s):  
Predatory Fish ◽  
Dimensional Structure ◽  
Visual Orientation ◽  
Energy Costs ◽  
Migratory Fish ◽  
Risk Of Predation ◽  
Significant Difference ◽  
Faunistic Complex ◽  
Orientation Mechanism ◽  
Available Information

In order to supplement the available information for the eco-hydraulic approach to designing fish passages, taking into account the taxonomic, dimensional structure, as well as taking into account the presence of predatory fish in the stream, the distribution of migratory fish of the boreal plain faunistic complex (Russian Federation) was studied. Three depth-velocity sections from the shore to the midstream were investigated: 5 m and 27.8 cm/s, 8 m and 44.4 cm/s, 11 m and 55.6 cm/s. Analysis of the migration distribution of fish showed that in the direction from the shore to the midstream, the proportion of representatives of Cyprinidae decreases from 41.8–24.3% and that of Percidae decreases from 25.0–18.4%. For individuals of two groups: the Acipenseridae and Lotidae, Coregonidae and Esocidae, patterns of distribution in the structure of migratory fish are opposite – their share increases with increasing speed and depth characteristics: 23.0–40.2% and 10.2–17.1%, respectively. An assessment of the dimensional structure revealed a feature of increase in the size range of fish from the shore to the midstream: the dominance of small individuals (<10 cm) in the shore area is replaced by the dominance of large fish (> 30 cm) in the area of higher speeds and depths. A significant difference in the distribution for all studied taxonomic fish groups between the shore and the midstream was shown. Thus, it has been established that for Cyprinidae during the migration period, the choice shifts in favour of minimizing energy costs, and the choice to avoid the risk of predation from individuals of the groups: Coregonidae and Esocidae, and also Percidae, shifts in favour of the former. The distribution of perch is influenced by the reduction of energy costs and the simultaneous avoidance of predation and cannibalism. For the fish group Acipenseridae and Lotidae, their predominance in the deeper area is due to their less developed visual orientation mechanism in the stream because they are bottom-living fish species.

scholarly journals Fish distribution in riverbed depression and conjugated reservoirs (effects of lighting and turbulence)

2019 ◽  
Vol 2019 (4) ◽  
pp. 42-54
Author(s):  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Open Water ◽  
Fish Population ◽  
Water Bodies ◽  
Predatory Fish ◽  
Dark Time ◽  
Risk Of Predation ◽  
Significant Difference ◽  
Irtysh River ◽  
Riverbed Depression ◽  
The Irtysh River

The paper describes the studies carried out by the hydroacoustic method in the open water period (spring) in the water area of the riverbed depression of the Irtysh River and its conju-gated water bodies (Western Siberia, the Russian Federation) in 2017. Collectively investigated reservoirs form a laminar-turbulent system, as they vary in intensity and direction of currents which form a certain turbulence and turbidity. It has been stated that in the dark time the fish population density increases in the waters of the reservoir with the maximal turbulence and turbidity rates - 166 NTU (the Irtysh river), and decreases in other water bodies (in the Konda river - 20.75 NTU and in the lentic section of the riverbed depression - 25 NTU). In the waters of conjugate reservoirs an increasing share of cyprinids is accompanying by a decrease in the proportion of predatory fish, while with an increase in predatory fish, on the contrary, the proportion of cyprinids decreases. A significant difference (P < 0.001) in terms of fish density was noted in the dark time. It was found that of the two factors (time of the day and turbulence) the second factor has a significant reliable effect (F = 18.518; P < 0.001) on the variable of fish population average density, both factors reliably interacting (F = 3.982; P = 0.037). There has been shown a transition of non-predatory fish to the site that is visually and hydrodynamically the most difficult for finding prey, which seems to be an element of reducing the risk of predation. Thus, there was found a significant influence of an abiotic factor of turbulence and, consequently, arising turbidity when interacting with the illumination factor on forming the increased fish concentration in the waters of the riverbed depression during the open water period.

scholarly journals The Syrian Golden Hamster: A Model for the Cardiomyopathy of Friedreich's Ataxia

1979 ◽  
Vol 6 (2) ◽  
pp. 223-226 ◽  
Author(s):  
J. Azari ◽  
T. Reisine ◽  
A. Barbeau ◽  
H.I. Yamamura ◽  
R. Huxtable
Keyword(s):  
Adrenergic Receptor ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Laboratory Model ◽  
Receptor Density ◽  
Significant Difference ◽  
Calcium Magnesium ◽  
The Difference ◽  
Whole Heart ◽  
Available Information

SummaryIn light of the available information on the cardiomyopathy of Friedreich's ataxia, the cardiomyopathic Syrian hamster may be an appropriate laboratory model. Cardiomyopathy in these animals is a result of calcium accumulation. We analyzed the atria and right and left ventricles from cardiomyopathic (CM) and random bred (RB) animals for calcium, magnesium, and iron concentrations at 30-40 and 60-70 days of age (age of maximum lesioning). There are no significant differences in the concentration of iron or magnesium among age-matched groups. The concentration of calcium in the left ventricles of the CM animals at 60 days old is 14 fold higher than that of R B animals. Although there is a significant difference in the concentration of calcium in the left ventricles of younger animals, it is not as pronounced as the difference in older animals. Analysis of the taurine concentration in 30-40 day old animals revealed that the CM animals show slightly higher taurine concentrations than RB in the whole heart. In 60 day old CM hamsters the ß-adrenergic receptor density of the ventricles is unchanged. This indicates that calcium overload is not due to a drene rg i c super sensitivity.

scholarly journals The strength of a female mate preference increases with predation risk

2008 ◽  
Vol 276 (1657) ◽  
pp. 775-780 ◽  
Author(s):  
Tae Won Kim ◽  
John H Christy ◽  
Stefan Dennenmoser ◽  
Jae C Choe
Keyword(s):  
Sexual Selection ◽  
Predation Risk ◽  
Perceived Risk ◽  
General Pattern ◽  
Visual Orientation ◽  
Relative Preference ◽  
Avian Predators ◽  
Risk Of Predation ◽  
Courtship Signals ◽  
Perceived Predation Risk

When females search for mates and their perceived risk of predation increases, they less often express preferences for males that use conspicuous courtship signals, relaxing sexual selection on production of these signals. Here, we report an apparent exception to this general pattern. Courting male fiddler crabs Uca beebei sometimes build pillars of mud at the openings to their burrows in which crabs mate. Females visit several males before they choose a mate by staying and breeding in their burrows, and they preferentially visit males with pillars. Previous studies suggested that this preference is based on a visual orientation behaviour that may reduce females' risk of predation while searching for a mate. We tested this idea by determining whether the female preference for males with pillars increases with perceived predation risk. We attracted avian predators to where crabs were courting and measured the rates that sexually receptive females visited courting males with and without mud pillars. Under elevated risk, females continued to search for mates and they showed a stronger relative preference for males with pillars. Thus, when predation risk is high, females may continue to express preferences that are under natural selection because they help females avoid predation, strengthening sexual selection for use of the preferred signal.

scholarly journals Recurrent pyogenic granuloma: an update

2015 ◽  
Vol 1 (1) ◽  
pp. 22 ◽  
Author(s):  
Rami A. Al-shiaty ◽  
Bacem A. E. Ottoman
Keyword(s):  
Alcian Blue ◽  
Periodic Acid ◽  
Pyogenic Granuloma ◽  
T Test ◽  
The Other ◽  
Dimensional Structure ◽  
Periodic Acid Schiff ◽  
Fibrous Stroma ◽  
Significant Difference ◽  
Initial Appearance

<p class="abstract"><strong><span lang="EN-US">Background: </span></strong>Given the fierce controversy about the nature of pyogenic granulomas, starting with its unfitting name and ending up with its ideal treatment modality, this paper tries to numerically identify some predisposing factors of recurrence.</p><p class="abstract"><strong><span lang="EN-US">Methods: </span></strong>The literature was initially reviewed and a total of twenty recurrent cases of pyogenic granuloma were contrasted, on one hand, to their initial appearance. On the other hand, all are contrasted to a similar number of normal mucosa using three histochemical stains: Alcian blue, periodic acid-Schiff and Masson’s trichrome.</p><p class="abstract"><strong><span lang="EN-US">Results: </span></strong>For all recurrent lesions, all specimens showed myxoid structure histologically even if their initial appearance had possessed a sparse myxoid structure. The age of recurrence has been correlated to the histochemical findings. For the Alcian Blue stain (AB), the value of t-test was 3.808840. The pertaining value of P was 0.000593. The result was significant at P ≤0.05. For the PAS stain, the value of t-test was 3.640327. The value of P was 0.000871. The result was significant at P ≤0.05. In Masson’s trichrome staining, the value of t-test was 3.100816. The value of P was 0.002942. The result was significant at P ≤0.05. Accordingly, all stains showed significant difference in fibrous content in the initial and recurrent lesions. Conversely, the count of both endothelial vessels and inflammatory infiltrates in the recurrent lesions were significantly lower than the primary precursors.</p><p class="abstract"><strong><span lang="EN-US">Conclusions: </span></strong>Given that collagen fibers are continually degraded and resynthesized while proteolytic degradation occur outside the cells through the activity of enzymes called  matrix metalloproteinases (MMPs), it is suggested that MMPs -positively expressed by PAS reactions- account for the spacing of the fibrous stroma, allowing for reshaping the three dimensional structure of the connective tissue. Myxoid structures are certainly promoting recurrence either via excessive secretion of hyaluronic acids or unknown mechanisms. The undisputed fact is the presence of myxoid structures in all our reported recurrent cases. Both inflammatory cascade and endothelial proliferation have no vital role in the recurrence according to our morphometric results. Finally, PAS stain should give more details in examining PGs than the other recruited counterparts.</p><p class="abstract"><strong><span lang="EN-US">Keywords: </span></strong><span lang="EN-US">Recurrent pyogenic granuloma, PAS stain, Myxoid structures, Etiopathogensis</span></p><p class="keywords"> </p>

scholarly journals Régime Alimentaire De Hemichromis Fasciatus (Perciformes, Cichlidae) Dans Le Lac De Barrage Hydroélectrique D’ayamé 2 (Côte D’ivoire)

2017 ◽  
Vol 13 (30) ◽  
pp. 126
Author(s):  
Blahoua Kassi Georges ◽  
Adou Yedehi Euphrasie ◽  
Gogbé Zeré Marius ◽  
N’Douba Valentin
Keyword(s):  
Cote D'ivoire ◽  
Food Habits ◽  
Significant Variation ◽  
Côte D’Ivoire ◽  
Predatory Fish ◽  
Régime Alimentaire ◽  
Relative Importance ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Significant Difference

The diet of Hemichromis fasciatus (Perciformes, Cichlidae) was studied in the lake dam of Ayame 2 (Côte d'Ivoire) from September 2015 to August 2016. A total of 141 specimens were captured using gill nets and hawks. The relative importance of food index has been calculated to assess the relative abundance of the preys. The standard length of fish varied between 70 mm and 250 mm. The global percentage of emptiness and intestinal coefficient mean were 23.40 % and 1.35 ± 0.48 respectively. The food spectra constituted of fishes, insects, arachnids and plants debris showing that this species an omnivorous fish with predatory fish tendency. The comparison of the food habits between size ranges (LS ≤ 110 mm and LS ˃ 110 mm) did not show any significant difference. But, a significant variation of the diet according the sexes and seasons was observed.

Advances in Fish Tagging and Marking Technology

2012 ◽  
Keyword(s):  
Sockeye Salmon ◽  
Release Site ◽  
Migratory Fish ◽  
The Poor ◽  
The Pacific ◽  
Significant Difference ◽  
Haplotype Frequencies ◽  
Acoustic Tags ◽  
The Pacific Ocean ◽  
Salmon Hatchery

<i>Abstract</i>.—We investigated the marine migratory behavior and survival of Sakinaw Lake sockeye salmon <i>Oncorhynchus nerka </i>during their outbound migration as juveniles and return migration as adults two or more years later by tracking individuals that had been implanted with Vemco acoustic tags programmed to have two periods of active transmission. We tracked both hatchery-reared anadromous sockeye salmon (‘hatchery sockeye’) and wild nonanadromous ‘kokanee,’ two genetically-distinct, sympatric ecotypes inhabiting Sakinaw Lake, British Columbia. Tagged kokanee were distinguished from wild sockeye by haplotype frequencies at two mitochondrial DNA genes. Migrations were inferred from detections by the Pacific Ocean Shelf Tracking (POST) receivers, and supplemental tracking near the release site and in Sakinaw Lake. We found no significant differences between the ecotypes in the proportion of ‘migratory’ fish (those detected migrating seaward by POST telemetry in the year of release, 42% of all 254 fish released) or in the proportion of ocean-going fish (those detected at receivers near the open ocean, 20% of all fish released). Seaward migration in both ecotypes was primarily northward through Johnstone Strait in 2 of the 3 years studied (92% of migratory fish in 2004 and 84% in 2006). A significantly higher proportion of fish moved southward in 2005 (45% of migratory fish) than in 2004 or 2006, but this difference could not be attributed to ecotype, body size, or release date. One significant difference observed between the ecotypes was that 6 kokanee but no sockeye migrated back into Sakinaw Lake within 2 weeks of release in 2006. The number of tagged fish detected as returning adults with operational tags was low (3 sockeye at the release site and 2 kokanee at Sakinaw Creek), but none of these fish had been detected crossing seaward POST lines as juveniles and thus appeared to be nonmigratory. The adult return rate of these nonmigratory tagged fish (3.4% in sockeye, 4.3% in kokanee) was higher than for migratory tagged fish (0% for both ecotypes). This discrepancy suggests that factors outside the Strait of Georgia have caused the poor marine survival that is preventing recovery of the endangered Sakinaw sockeye population (mean <0.2% since 2003).

scholarly journals Nutrition education of young women

1994 ◽  
Vol 71 (5) ◽  
pp. 789-798 ◽  
Author(s):  
Gill A. Fine ◽  
D. M. Conning ◽  
Cella Firmin ◽  
Anne E. De Looy ◽  
M. S. Losowsky ◽  
...  
Keyword(s):  
Nutrition Education ◽  
White Women ◽  
Learning Ability ◽  
Nutritional Knowledge ◽  
Control Groups ◽  
Training Material ◽  
Significant Difference ◽  
Baseline Group ◽  
Available Information ◽  
And Control

White women aged 25–34 years (n 264) from the lower socio-economic classes (C2, D and E) were classified according to their motivation in respect of health and their educational attainment and arithmetical ability. They were randomly allocated to three groups. One group (test) was given a course in basic nutrition consisting of a video and booklet, each embellished with motivational material. Those classed as of low ability also received the training material in simplified format. A second group (control) received a video and booklet with no motivational or simplified materials. The third group (baseline) received no tuition and represented a control of publicly available information during the period of the experiment. The participants answered a series of questions by administered questionnaire to measure their nutritional knowledge before and one week after they viewed the video programme. All participants achieved significantly higher scores at the second questionnaire. The test and control groups achieved significantly higher scores than the baseline group but there was no significant difference between the test and control groups. The presentation of motivational or simplified materials had no significant effect on learning ability though those classified as more highly motivated and of higher ability achieved higher scores at each questionnaire. The results indicate that young adult females can be taught basic nutrition irrespective of their motivation or ability.

Does exposure to cues of fish predators fed different diets affect morphology and performance of Northern Leopard Frog (Lithobates pipiens) larvae?

2013 ◽  
Vol 91 (4) ◽  
pp. 203-211 ◽  
Author(s):  
Rayan El Balaa ◽  
Gabriel Blouin-Demers
Keyword(s):  
Life History ◽  
Phenotypic Plasticity ◽  
Perceived Risk ◽  
Leopard Frog ◽  
Predatory Fish ◽  
Lithobates Pipiens ◽  
Northern Leopard Frog ◽  
Risk Of Predation ◽  
Fish Predators ◽  
Plastic Changes

Phenotypic plasticity allows animals to change their morphological and life-history traits when exposed to predator cues, which modifies performance and can enhance survival but engender costs. Thus, the extent of plastic changes should vary in relation to the perceived risk of predation. We tested the hypothesis that plastic changes in morphology (and their effect on performance) and life history of developing Northern Leopard Frog (Lithobates pipiens (Schreber, 1782)) larvae vary when exposed to cues of fish predators fed different diets. During development, we exposed tadpoles to control cues, cues from brown bullhead (Ameiurus nebulosus (Lesueur, 1819)) fed trout pellets, or cues from A. nebulosus fed L. pipiens tadpoles. Tadpoles exposed to predatory fish cues had smaller bodies, deeper tail fins, slower growth and development rates, and better turning performance than tadpoles that were not exposed to predatory fish cues, but we found limited evidence that the predator’s diet had an effect on phenotypic plasticity. Predator diet affected tail morphology and activity, but the latter effect was only marginally significant. Lithobates pipiens tadpoles clearly respond to predatory fish cues, but it remains unclear whether their response is modulated by the predator’s diet.

Studies of structure and specificity of some antigen-antibody complexes

1989 ◽  
Vol 323 (1217) ◽  
pp. 487-494
Keyword(s):  
Monoclonal Antibodies ◽  
Three Dimensional ◽  
High Specificity ◽  
Single Amino Acid ◽  
Dimensional Structure ◽  
X Ray ◽  
Homologous Antigen ◽  
Significant Difference ◽  
Antigen Antibody ◽  
Antibody Interactions

By using X -ray diffraction and immunochemical techniques, we have exploited the use of monoclonal antibodies raised against hen egg lysozyme (HEL) to study systematically those factors responsible for the high specificity of antigen -antibody interactions. HEL was chosen for our investigations because its three-dimensional structure and immunochemistry have been well characterized and because naturally occurring sequence variants from different avian species are readily available to test the fine specificity of the antibodies. The X-ray crystal structure of a complex formed between HEL and the Fab D1.3 shows a large complementary surface with close interatomic contacts between antigen and antibody. Thus single amino acid sequence changes in heterologous antigens give antigen-antibody association constants that are several orders of magnitude smaller than that of the homologous antigen. For example, a substitution of His for Glu at position 121 in the antigen is sufficient to diminish significantly the binding between D1.3 and the variant lysozyme. The conformation of HEL when complexed to D1.3 shows no significant difference from that seen in the free molecule, and immunobinding studies with other anti-HEL antibodies suggest that this observation may be generally true for the system of monoclonal antibodies that we have studied.

Information Seeking with Limitations on Available Information and Resources

1975 ◽  
Vol 17 (5) ◽  
pp. 502-513 ◽  
Author(s):  
Jerrold M. Levine ◽  
Michael G. Samet ◽  
Rae E. Brahlek
Keyword(s):  
Information Seeking ◽  
Three Dimensions ◽  
Range Limit ◽  
Limit Condition ◽  
Additional Information ◽  
Significant Difference ◽  
Factor Design ◽  
The Subject ◽  
Available Information ◽  
The Given

Nineteen subjects were given a multinomial Bayesian task in which they had to determine which of four populations was being sampled. Each sequentially drawn data item was described on one of three dimensions of differing diagnosticity; knowledge of the given dimension was presented and the subject could choose to purchase or pass it up. Sixty computer-generated problems were administered in a 2 times 3 within-subject factorial design. A problem contained either 16 or 24 total items of information, and subjects were given sufficient resources to purchase either 50%, 75%, or 100% of the available information. A second study incorporating the same task, involving 20 subjects, and employing a one-factor design was carried out to compare available information limits that were specified either exactly (12 and 24 items) or within a range (12 to 24 items). Results indicated that: (1) significantly more information was sought as both amount of available information and resources increased; (2) as response uncertainty was reduced by the acquisition of additional information, accuracy generally increased; (3) when more information was available, subjects were more efficient in selecting data items; and (4) there was no significant difference in information seeking or accuracy between the average of the two exact-limit conditions and the range-limit condition of amount of available information.

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