scholarly journals Estimation of Some Population Parameters of Squalius cephalus (Linnaeus 1758) in Tabakane Stream (Ordu-Turkey)

2021 ◽  
Author(s):  
Serdar YEDIER
Keyword(s):  
Population Parameters ◽  
Squalius Cephalus

Source populations in coastal crabs: population parameters affecting egg production

2009 ◽  
Vol 7 ◽  
pp. 31-43 ◽  
Author(s):  
AAV Flores ◽  
CC Gomes ◽  
WF Villano
Keyword(s):  
Egg Production ◽  
Population Parameters ◽  
Source Populations

Estimating Population Parameters of the Cladocera

1998 ◽  
Vol 34 (4-5) ◽  
pp. 41-49
Author(s):  
V. I. Razlutskii
Keyword(s):  
Population Parameters

scholarly journals Does Larval Rearing Diet Lead to Premating Isolation in Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae)?

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 203
Author(s):  
Xue-Yuan Di ◽  
Bin Yan ◽  
Cheng-Xu Wu ◽  
Xiao-Fei Yu ◽  
Jian-Feng Liu ◽  
...  
Keyword(s):  
Mate Choice ◽  
Spodoptera Litura ◽  
Artificial Diet ◽  
Survival Rates ◽  
Intrinsic Rate Of Increase ◽  
Larval Rearing ◽  
Population Parameters ◽  
Premating Isolation ◽  
Behavioral Isolation ◽  
Rate Of Increase

Host plant preference during the larval stage may help shape not only phenotypic plasticity but also behavioral isolation. We assessed the effects of diet on population parameters and mate choice in Spodoptera litura. We raised larvae fed on tobacco, Chinese cabbage, or an artificial diet, and we observed the shortest developmental time and highest fecundity in individuals fed the artificial diet. However, survival rates were higher for larvae on either of the natural diets. Population parameters including intrinsic rate of increase and finite rate of increase were significantly higher with the artificial diet, but this diet led to a lower mean generation time. Copulation duration, copulation time, and number of eggs reared significantly differed between diets. In terms of mate choice, females on the artificial diet rarely mated with males fed on a natural host. Our results support the hypothesis that different diets may promote behavioral isolation, affecting mating outcomes. Thus, findings for populations fed an artificial diet may not reflect findings for populations in the field.

scholarly journals Mild Abiotic Stress Affects Development and Stimulates Hormesis of Hemp Aphid Phorodon cannabis

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 420
Author(s):  
Roma Durak ◽  
Malgorzata Jedryczka ◽  
Beata Czajka ◽  
Jan Dampc ◽  
Katarzyna Wielgusz ◽  
...  
Keyword(s):  
Glutathione Transferase ◽  
Insect Pest ◽  
Mild Stress ◽  
Population Parameters ◽  
Live Feed ◽  
Average Fecundity ◽  
The Impact ◽  
Considerable Damage ◽  
Group 1 ◽  
Future Management

The hemp aphid Phorodon cannabis Passerini is a well- known (Asia, Europe) or newly emerging (North America) insect. It is a monophagous insect pest causing considerable damage in field and glasshouse cultivations. The aim of this work was to study the effects of meteorological (temperature) and agronomical (herbicide) factors on the biology of the hemp aphid. In one experiment, hemp plants were kept at constant temperatures ranging from 20 to 30 °C, and aphid survival and fecundity were measured. In a related experiment conducted at 20 °C, plants were treated with field-appropriate rates of a selective graminicide containing quizalofop-P-tefuryl (40 gL−1, 4.38%, HRAC group 1), commonly used to control weeds in hemp, and aphid enzyme activity was measured in addition to population parameters. We found that hemp aphids could live, feed and reproduce within the whole studied range of temperatures, demonstrating its great evolutionary plasticity. However, the optimal temperature for development was 25 °C, at which the insect lived and reproduced for 25 and 15 days, respectively, with an average fecundity of 7.5 nymphs per reproduction day. The herbicide treatment increased the activity of superoxide dismutase (SOD), catalase (CAT), β-glucosidase, S-glutathione transferase (GST), oxidoreductive peroxidase (POD), and polyphenol oxidase (PPO) in the aphids, but only on certain days after treatment, which indicates a mild stress in aphid tissues, related to a higher reproduction and changed feeding behavior; aphids moved from the actively growing tips compared to untreated plants. The results of these experiments are discussed in terms of the impact on the future management of this pest.

scholarly journals A Frequentist Alternative to Significance Testing, p-Values, and Confidence Intervals

Econometrics ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 26 ◽  
Author(s):  
David Trafimow
Keyword(s):  
Present Article ◽  
Confidence Intervals ◽  
Null Hypothesis ◽  
A Priori ◽  
Significance Testing ◽  
Population Parameters ◽  
Null Hypothesis Significance Testing ◽  
P Values ◽  
Statistical Procedures ◽  
Major Section

There has been much debate about null hypothesis significance testing, p-values without null hypothesis significance testing, and confidence intervals. The first major section of the present article addresses some of the main reasons these procedures are problematic. The conclusion is that none of them are satisfactory. However, there is a new procedure, termed the a priori procedure (APP), that validly aids researchers in obtaining sample statistics that have acceptable probabilities of being close to their corresponding population parameters. The second major section provides a description and review of APP advances. Not only does the APP avoid the problems that plague other inferential statistical procedures, but it is easy to perform too. Although the APP can be performed in conjunction with other procedures, the present recommendation is that it be used alone.

THE MEASUREMENT AND ANALYSIS OF TRIPLE CORRELATIONS

1964 ◽  
Vol 42 (6) ◽  
pp. 1101-1115 ◽  
Author(s):  
Philip B. Smith
Keyword(s):  
Gamma Rays ◽  
Heavy Particle ◽  
Original Data ◽  
Population Parameters ◽  
True Solution ◽  
Error Matrix ◽  
Mixing Ratios ◽  
Triple Correlation ◽  
Measurement And Analysis

The measurement and analysis of the intensity–direction correlation of gamma rays emitted in cascade following heavy-particle capture are treated. A procedure is discussed which is based upon the expansion of the triple-correlation intensity in terms of the set of angular functions orthogonal over the space of the emission (or absorption) directions. This is in contrast to the usual method which expresses the correlation in terms of Legendre polynomials. In the analysis procedure proposed, the population parameters are found directly from the original data, with the gamma-radiation mixing ratios assigned. The least-squares equations representing the best fit to the data contain the population parameters linearly and are solved by a standard computer program which also gives the value of χ2. The true solution is then found by varying the mixing ratios until a minimum in χ2 is reached. In addition to the determination of the population parameters of the decaying state and the mixing ratios of the gamma rays in the cascade, the calculation of the error matrix of these quantities, and the calculation of the formation parameters in simple capture, are described.

Inferring age from otolith measurements: a review and a new approach

2004 ◽  
Vol 61 (7) ◽  
pp. 1269-1284 ◽  
Author(s):  
RIC Chris Francis ◽  
Steven E Campana
Keyword(s):  
Simulation Experiment ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
New Method ◽  
Population Parameters ◽  
Benefit Analysis ◽  
Mixture Analysis ◽  
New Approach ◽  
Individual Fish ◽  
The Cost

In 1985, Boehlert (Fish. Bull. 83: 103–117) suggested that fish age could be estimated from otolith measurements. Since that time, a number of inferential techniques have been proposed and tested in a range of species. A review of these techniques shows that all are subject to at least one of four types of bias. In addition, they all focus on assigning ages to individual fish, whereas the estimation of population parameters (particularly proportions at age) is usually the goal. We propose a new flexible method of inference based on mixture analysis, which avoids these biases and makes better use of the data. We argue that the most appropriate technique for evaluating the performance of these methods is a cost–benefit analysis that compares the cost of the estimated ages with that of the traditional annulus count method. A simulation experiment is used to illustrate both the new method and the cost–benefit analysis.

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz
Keyword(s):  
Sex Ratio ◽  
Ringed Seal ◽  
Adult Males ◽  
Population Parameters ◽  
Phoca Hispida ◽  
Age Class ◽  
Ringed Seals ◽  
Males And Females ◽  
The Mean ◽  
Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

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