Influence of Changing Seasons on Schooling Behavior of Yellow Perch

1968 ◽  
Vol 25 (4) ◽  
pp. 711-716 ◽  
Author(s):  
Gary L. Hergenrader ◽  
Arthur D. Hasler
Keyword(s):  
School Size ◽  
Yellow Perch ◽  
Light Transmission ◽  
Perca Flavescens ◽  
Lake Mendota ◽  
Schooling Behavior ◽  
Bottom Fish ◽  
The Mean ◽  
Definition Of ◽  
The Individual

Analysis of echo-sounder and sonar records made on Lake Mendota during summer and winter indicated that the schooling behavior of yellow perch, Perca flavescens (Mitchill), changed markedly between the two seasons. The distance separating individuals in schools during summer was less than 1.5–2.0 ft, consequently producing dense traces on the recorder charts which showed no definition of individuals. During winter, however, the fish-to-fish distances often were greater than 1.5–2.0 ft, producing many traces showing the individual fishes in a school. The mean distance between the top and bottom fish in a school during winter was 22.1 ft (6.7 m); in summer only 8.5 ft (2.5 m). High correlations existed between light transmission of the water and school size (r =.77) and between temperature and school size (r = −.89). The possible adaptive significance of this seasonal change in behavior is discussed.

Predicting the Vertical Distribution of Fish Populations: Analysis of Cisco, Coregonus artedii, and Yellow Perch, Perca flavescens

1985 ◽  
Vol 42 (6) ◽  
pp. 1178-1188 ◽  
Author(s):  
Lars G. Rudstam ◽  
John J. Magnuson
Keyword(s):  
Vertical Distribution ◽  
Yellow Perch ◽  
Factor Model ◽  
Perca Flavescens ◽  
Fish Population ◽  
Lake Mendota ◽  
Vertical Distributions ◽  
Preferred Temperatures ◽  
Coregonus Artedii ◽  
The Vertical Distribution

We develop a model based on fish behavior in temperature and oxygen gradients that yields quantitative predictions of the vertical distribution of a fish population throughout the water column. The model was tested against observed vertical distributions of cisco, Coregonus artedii, and yellow perch, Perca flavescens, in 1981 and 1982 from five Wisconsin lakes. In some cases, the model seemed adequate for cisco, but in most cases, they occupied a temperature lower than their final preferendum. Occupation of lower temperature is consistent with a response to less than ad libitum food rations expected in these oligotrophy to mesotrophic lakes. In Lake Mendota, which is eutrophic with an anaerobic hypolimnion, cisco occupied temperatures higher than predicted by the model. For perch distributions, avoidance of high light intensities appears important. We did not observe effects of interspecific segregation between cisco and perch in their vertical distributions beyond that expected from differences in their preferred temperatures. Deviations of actual distributions from predictions of our relatively simplistic two-factor model can be used to help identify and evaluate other important physical and biotic factors influencing vertical distributions.

Diel Activity and Vertical Distribution of Yellow Perch (Perca flavescens) Under the Ice

1966 ◽  
Vol 23 (4) ◽  
pp. 499-509 ◽  
Author(s):  
Gary L. Hergenrader ◽  
Arthur D. Hasler
Keyword(s):  
Vertical Distribution ◽  
Activity Pattern ◽  
Yellow Perch ◽  
Depth Distribution ◽  
Perca Flavescens ◽  
Diel Activity ◽  
Limited Extent ◽  
Diel Pattern ◽  
Lake Mendota ◽  
Individual Fish

Use of echo sounders showed that, under the ice in Lake Mendota, yellow perch (Perca flavescens Mitchill) have a bimodal diel pattern of activity. The first peak of activity, during midmorning, was much higher than the second, in midafternoon. Schools of fish in mid water made up the bulk of the fish traces per hour although individual fish were also commonly recorded. At night, when activity was much reduced, principally single fish were observed. The fish swam much more slowly at night than during the day.The activity pattern generally agreed with those reported by investigators for other lakes in that the perch were active during the day and relatively inactive at night.No well-defined change in depth distribution was noted. There was a tendency for the fish to move away from the bottom to a limited extent at night but no marked movement was recorded. The majority of fish were most often recorded at a depth of 30–60 ft (9–18 m), the main concentrations being in areas of the lake more than 50 ft (15 m) deep.

scholarly journals SEA LEVEL ANALYSES OF PSMSL SERIES BY PROXIMITY AND COLLINEARITY COEFFICIENTS

2013 ◽  
Vol 31 (5) ◽  
pp. 23
Author(s):  
Afrânio Rubens de Mesquita ◽  
Carlos Augusto De Sampaio França ◽  
Marco Antonio Corrêa
Keyword(s):  
Sea Level ◽  
San Francisco ◽  
International Association ◽  
Regression Line ◽  
Mean Sea Level ◽  
Distribution Shape ◽  
The Mean ◽  
Global Sea Level ◽  
Definition Of ◽  
The Individual

ABSTRACT. Annual mean sea level data distributed by PSMSL (Permanent Service for the Mean Sea Level) of IAPSO (International Association for the Physical Sciences of the Oceans) were analysed in the search for global sea level co-variants and invariants. The correlation coefficient ρ , taken as a measure of collinearity ρc in time series, was shown to depend on the ratio of two variances and then invariant with the inclination β of the regression line yri(ti) = tan(β)xi + α , α the intercept, relative to the Cartesian coordinated axes. Also invariant with the trends βt is the distance i of the discrete data points (xi, yi)i = 1, 2 . . . , n , to the regression straight line previously calculated. The mean over all i was taken as a measure, a coefficient of proximity of each series. Analysis of the two coefficients allowed the definition of a variable F = ρc × whose values, in consequence, are also invariants with the trends βt of the individual series. The same can be said about the F distribution shape, in a plot that allowed the comparison of the F values of all ports round the globe. Ports as of Cananeia (Brazil), San Francisco (USA), Brest (France), Antofagasta (Chile), and Takoradi, from Gana (Africa), occupy very distinct and relatively permanent positions in the plot, which, for longer series, are also invariant with their length in years. Analyses of a plot of ρc and βt showed also that although they are statistically mutually invariants, their values, calculated from PSMSL series, seem to be distributed as covariant variables. All mentioned invariance and co-variance seem related to what appears to be a limit globally imposed on the variability of planetary sea level series from all ports of islands and continents, by the Earth’s gravity field. The study of the induced co-variance between , ρc and the F values, with the trends , may help to unveil the characteristics of the constraints on the planetary relative to sea level series. Keywords: collinearity coefficient, proximity coefficient, PSMSL series, regression line, planetary series, trend invariants.  RESUMO. Valores médios anuais de nível do mar distribuídos pelo PSMSL (Serviço Permanente para o Nível do Mar) da IAPSO (Associação Internacional para as Ciências Físicas dos Oceanos) são analisados na procura de invariantes globais do nível do mar. O coeficiente de correlação ρ , admitido como uma medida da colinearidade em séries de tempo ρc, foi mostrado ser dependente da razão de duas variâncias e então invariante com relação à inclinação β da reta de regressão relativa aos eixos coordenados cartesianos. Também invariante com a inclinação β é a distância média dos pontos discretos da série até a reta de regressão. A distância média é tomada como uma medida, como um coeficiente de proximidade dos pontos da série à reta. A análise desses coeficientes ( ρc e ) e sua invariância com relação à rotação do sistema de coordenadas permitiram a definição de uma variável F = ρc × que é também invariante com o sistema e pode ser tomada como uma constante de cada s´erie, que caracteriza cada série do conjunto de séries planetárias e, em consequência a distribuição dos valores F contidos nas series PSMSL. Nessa distribuição os portos de Cananeia (Brasil), São Francisco, (EUA), Brest (França), Antofagasta (Chile) e Takoradi, Ghana (África), ocupam posições bastante particulares, relativamente permanentes e invariantes com o comprimento das séries. Análises das variáveis colinearidade ρc e tendências βt, mostraram também, que embora elas sejam estatisticamente mutuamente invariantes, seus valores calculados a partir das séries PSMSL, são linear e globalmente distribuídos como variáveis covariantes. Isso é interpretado como devido a limites naturais geofisicamente impostos nas séries planetárias. O estudo dessa dependência induzida entre ρc, βt, e F , pode, eventualmente, ajudar a descobrir as características desses vínculos planetários. Palavras-chave: coeficiente de colinearidade, coeficiente de proximidade, séries do PSMSL, reta de regressão, séries planetária, tendências constantes.

The Effects of High Temperatures on Roach (Rutilus Rutilus)

1959 ◽  
Vol 36 (1) ◽  
pp. 203-216 ◽  
Author(s):  
ANTHONY W. COCKING
Keyword(s):  
Gall Bladder ◽  
Survival Time ◽  
Median Survival ◽  
Median Survival Time ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Rutilus Rutilus ◽  
Lethal Temperature ◽  
Roach Rutilus Rutilus ◽  
The Mean

1. The temperature at which 50% of a sample of roach (Rutilus rutilus) die within a week cannot be raised above 33.5° C. by raising the acclimatization temperature. 2. The roach is about as eurythermal as the yellow perch (Perca flavescens). 3. The mean asphyxial concentration of oxygen at 30 and 32°C is approximately 0.8 mg./l. 4. Median survival time at any lethal temperature increases with increase in acclimatization temperature; survival time for any acclimatization temperature decreases as test temperature increases; the temperature at which 50% of a sample die within a week rises by about 1° C. for each 3° C. rise in acclimatization temperature. 5. The behaviour, on transfer to higher temperatures, depends on the acclimatization temperature and the size of the jump in temperature and can be divided into five characteristic stages. 6. Dying fish develop a black pattern; myotomic swimming muscles die first and opercular muscles last. The heart was still beating when the fish were opened but the gall bladder was abnormal.

Gape Limitation and Prey Selection in Larval Yellow Perch (Perca flavescens), Freshwater Drum (Aplodinotus grunniens), and Black Crappie (Pomoxis nigromaculatus)

1991 ◽  
Vol 48 (10) ◽  
pp. 1919-1925 ◽  
Author(s):  
Denise M. Schael ◽  
Lars G. Rudstam ◽  
John R. Post
Keyword(s):  
Yellow Perch ◽  
Prey Selection ◽  
Perca Flavescens ◽  
Fish Length ◽  
Prey Selectivity ◽  
Lake Mendota ◽  
Pomoxis Nigromaculatus ◽  
Aplodinotus Grunniens ◽  
Gape Size ◽  
Freshwater Drum

We compared prey selection of larval yellow perch (Perca flavescens), freshwater drum (Aplodinotus grunniens), and black crappie (Pomoxis nigromaculatus) in Lake Mendota, Wisconsin. All three species had a diet dominated by copepods and selected progressively larger prey as fish length increased. For a given fish length, freshwater drum selected larger prey and black crappie selected smaller prey than yellow perch. These differences in prey selectivity were partly explainable from differences in gape to length relationships. Freshwater drum did have the largest gape for a given length of the three species, but gape size for black crappie and yellow perch were similar. Gape size predicted 67% of the variability in mean prey size ingested by yellow perch but only 15% for freshwater drum and 8% for black crappie. Although gape size did predict the upper limit of ingestible prey sizes and explained some of the differences in prey selectivity among the three species, both the degree to which the different fishes can ingest prey close to their gape limit and the degree to which gape predicted mean size of ingested prey varied among the three fish species.

Comparison of Fluorine(18)-fluorodeoxyglucose and Gallium(68)-citrate PET/CT in patients with tuberculosis

2019 ◽  
Vol 58 (05) ◽  
pp. 371-378
Author(s):  
Alfred O. Ankrah ◽  
Ismaheel O. Lawal ◽  
Tebatso M.G. Boshomane ◽  
Hans C. Klein ◽  
Thomas Ebenhan ◽  
...  
Keyword(s):  
Tracer Uptake ◽  
Pet Ct ◽  
The Mean ◽  
18F Fdg ◽  
Definition Of ◽  
Gallium 68 ◽  
Attending Physician ◽  
Pet Scans ◽  
The Brain

Abstract 18F-FDG and 68Ga-citrate PET/CT have both been shown to be useful in the management of tuberculosis (TB). We compared the abnormal PET findings of 18F-FDG- and 68Ga-citrate-PET/CT in patients with TB. Methods Patients with TB on anti-TB therapy were included. Patients had a set of PET scans consisting of both 18F-FDG and 68Ga-citrate. Abnormal lesions were identified, and the two sets of scans were compared. The scan findings were correlated to the clinical data as provided by the attending physician. Results 46 PET/CT scans were performed in 18 patients, 11 (61 %) were female, and the mean age was 35.7 ± 13.5 years. Five patients also had both studies for follow-up reasons during the use of anti-TB therapy. Thirteen patients were co-infected with HIV. 18F-FDG detected more lesions than 68Ga-citrate (261 vs. 166, p < 0.0001). 68Ga-citrate showed a better definition of intracerebral lesions due to the absence of tracer uptake in the brain. The mean SUVmax was higher for 18F-FDG compared to 68Ga-citrate (5.73 vs. 3.01, p < 0.0001). We found a significant correlation between the SUVmax of lesions that were determined by both tracers (r = 0.4968, p < 0.0001). Conclusion Preliminary data shows 18F-FDG-PET detects more abnormal lesions in TB compared to 68Ga-citrate. However, 68Ga-citrate has better lesion definition in the brain and is therefore especially useful when intracranial TB is suspected.

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

Platelet Hypersensitivity in Acute Malaria (Plasmodium falciparum) Infection in Man

1981 ◽  
Vol 46 (02) ◽  
pp. 547-549 ◽  
Author(s):  
E M Essien ◽  
M I Ebhota
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Infection ◽  
Light Transmission ◽  
Human Platelet ◽  
Platelet Rich Plasma ◽  
Wave Pattern ◽  
Falciparum Infection ◽  
Secondary Wave ◽  
Control Subjects ◽  
The Mean

SummaryDuring acute malaria infection, platelets in human platelet-rich plasma are hypersensitive to the addition of ADP between 1.0 uM and 5.0 uM, or adrenaline 0.11 uM as aggregating agents. The mean maximum aggregation amplitude (as % of light transmission) obtained from 8 subjects in response to added ADP (1.0 uM), 39.8 ± 27 (1SD), was significantly greater than the value in 6 controls (5.2±6.7 (1SD); t = 3, 51 P <0.005). A similar pattern of response was obtained with higher ADP concentrations (2.4,4.5 or 5.0 uM) in 22 patients and 20 control subjects (89.9±14.9% vs 77.8±16.5% (1SD) t = 2.45, P <0.02). Addition of 4.5 uM ADP to patient PRP usually evoked only a single aggregation wave (fused primary and secondary waves) while the typical primary and secondary wave pattern was usually obtained from controls.Mean plasma B-thromboglobulin (BTG) concentration in 7 patients (208.3 ± 15.6 ng/ml) was significantly higher than the value in 6 control subjects (59.2±15.7 ng/ml; t = 13.44, P <0.002).

The Autobiographical Subject and the Death Penalty

2013 ◽  
Vol 35 (2) ◽  
pp. 165-187
Author(s):  
E. S. Burt
Keyword(s):  
Death Penalty ◽  
First Person ◽  
Philosophical Investigation ◽  
The Subject ◽  
Definition Of ◽  
The Individual

Why does writing of the death penalty demand the first-person treatment that it also excludes? The article investigates the role played by the autobiographical subject in Derrida's The Death Penalty, Volume I, where the confessing ‘I’ doubly supplements the philosophical investigation into what Derrida sees as a trend toward the worldwide abolition of the death penalty: first, to bring out the harmonies or discrepancies between the individual subject's beliefs, anxieties, desires and interests with respect to the death penalty and the state's exercise of its sovereignty in applying it; and second, to provide a new definition of the subject as haunted, as one that has been, but is no longer, subject to the death penalty, in the light of the worldwide abolition currently underway.

SERUM THYROTROPHIN AND THE RESPONSE TO THYROTROPHIN RELEASING HORMONE IN SYMPTOMLESS AUTOIMMUNE THYROIDITIS AND IN BORDERLINE AND OVERT HYPOTHYROIDISM

1974 ◽  
Vol 75 (2) ◽  
pp. 274-285 ◽  
Author(s):  
A. Gordin ◽  
P. Saarinen ◽  
R. Pelkonen ◽  
B.-A. Lamberg
Keyword(s):  
Autoimmune Thyroiditis ◽  
Elevated Serum ◽  
Mean Value ◽  
Primary Hypothyroidism ◽  
Overt Hypothyroidism ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
The Mean ◽  
The Individual ◽  
Serum Tsh

ABSTRACT Serum thyrotrophin (TSH) was determined by the double-antibody radioimmunoassay in 58 patients with primary hypothyroidism and was found to be elevated in all but 2 patients, one of whom had overt and one clinically borderline hypothyroidism. Six (29%) out of 21 subjects with symptomless autoimmune thyroiditis (SAT) had an elevated serum TSH level. There was little correlation between the severity of the disease and the serum TSH values in individual cases. However, the mean serum TSH value in overt hypothyroidism (93.4 μU/ml) was significantly higher than the mean value both in clinically borderline hypothyroidism (34.4 μU/ml) and in SAT (8.8 μU/ml). The response to the thyrotrophin-releasing hormone (TRH) was increased in all 39 patients with overt or borderline hypothyroidism and in 9 (43 %) of the 21 subjects with SAT. The individual TRH response in these two groups showed a marked overlap, but the mean response was significantly higher in overt (149.5 μU/ml) or clinically borderline hypothyroidism (99.9 μU/ml) than in SAT (35.3 μU/ml). Thus a normal basal TSH level in connection with a normal response to TRH excludes primary hypothyroidism, but nevertheless not all patients with elevated TSH values or increased responses to TRH are clinically hypothyroid.

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