Marcello De Giosa

Major axis approach to the statistical analysis of the relative growth of Chinese mitten crab (Eriocheir sinensis) in the Odra estuary (Poland)

A total of 379 individuals of Eriocheir sinensis (198 males and 181 females) were captured in the Odra estuary (Poland). The crabs were thawed and their carapace length (CL), the maximum carapace width (CW) and the maximum height (CH) were measured. Measurements were also taken on each claw, the claw length (CHL1, the right claw; CHL2, the left claw), the width (CHW1 and CHW2 for the right and the left claw, respectively), and the height (CHH1 and CHH2 for the right and the left claw). For each crab, the wet weight was measured for each of the following body components: the whole crab (CrWe), the carapace (CaWe), the right claw (WRC) and the left claw (WLC). For females, the relationship between CL and CW, CH and CW were isometric, and for all linear measures, the relationship with CW was positively allometric. For males only this first relationship was isometric, but others were positively allometric. The differences between relative growth parameters for males and females were statistically significant.

Seasonal Changes in Condition Factor and Weight-Length Relationship of Invasive Carassius gibelio (Bloch, 1782) from Leszczynskie Lakeland, Poland

Samples of invasive cyprinid fish, the Prussian carp (Carassius gibelio), were collected by fyke nets in Leszczynskie Lakeland (Poland) during the summer and autumn, 2010, and during the spring, 2011. All captured fish were females. For each fish, the total weight () and the standard length () were measured and Fulton’s condition factor was computed. Graphical investigation and the Mann-Whitney-Wilcoxon test showed statistically significant location shift of the distribution from summer to autumn (upward) and from autumn to spring (downward). Relationship between total weight and standard length was described with the mean growth curve . Seasonal parameters ( and ) were estimated with a nonlinear regression approach, that is, numerical optimization methods. Growth was allometric in summer and autumn and isometric in spring. The differences between summer and autumn growth curves and between autumn and spring growth curves were statistically significant. The seasonality exhibited by the condition factor and the growth curve may be due to different spawning, breeding, and feeding activity in the different seasons and to variable environmental conditions.

The relative growth of walking legs of adult Chinese mitten crabs, Eriocheir sinensis in the Odra estuary (Poland). The major axis statistical modeling

We have quantified the relative growth of the merus and the propodus & carpus of walking legs of an adult of Eriocheir sinensis against the carapace width by fitting the major axis lines. Different lines have been fitted to data relative to male and female individuals. Slope and elevation tests have been performed to investigate sexual dimorphism. Isometry tests have been used to classify the relative growth of each part of the legs against the carapace width as isometric or allometric.All the slope tests have not rejected the null hypothesis of a common slope for the major axes fitted to male data and to female data. However, all the elevation tests have rejected the null hypothesis of a common elevation; so sexual dimorphism was detected for all measured leg parts. The isometry tests have rejected the null hypothesis of isometry only for the merus of the first (left and right) legs of male individuals. All the other isometry tests have not rejected the null hypothesis of isometry. So the relative growth of all the measured leg parts, but the merus of the first (left and right) legs of males, against the carapace width was isometric both for males and for females.

Free area estimation in a dynamic germ-grain model with renewal dropping process

A partially observed dynamic germ-grain model with renewal dropping process is considered. The expected fraction of free area function is estimated by a product integral-type estimator. Uniform consistency and asymptotic Gaussianity of the estimator are proved. Confidence bands and simulation results are also provided.

Free area estimation in a partially observed dynamic germ-grainmodel

The estimation problem of the expected local fraction of free area function S for a partially observed dynamic germ-grain model is presented. Properties of the estimators are proved by martingale and product integral methods. Confidence bounds are provided. Furthermore, an estimator of the hazard rate α ( t ) = − d S ( t ) / ( S ( t ) d t ) is obtained by the kernel function method and asymptotic properties of the estimator are proved and used to find confidence intervals. By a simulated illustrative example, the qualitative behavior of the estimators is shown.

On the Doléans function of set-indexed submartingales☆

A necessary and sufficient condition for the countable additivity of the Doleans function of a set-indexed weak submartingale is given in terms of stopping sets.

A generalized, nonlinear regression approach to the length-weight relationship of European perch (Perca fluviatilis L.) from the Polish coast of the southern Baltic Sea

Abstract Length-weight relationships in fish are important tools in fisheries management. The aim of this study was to estimate the growth curve W=aLb for European perch, Perca fluviatilis L., from the Polish coast of the southern Baltic Sea (ICES Subdivision 25). The data set comprised the total weights and total lengths of 827 specimens caught during the 2011-2013 period. The mean total length (TL) was 169.4 mm (range 100.0-310.0 mm), and the mean total weight was 83.9 g (range 11.3-553.2 g). First, a multiplicative error term and a linear regression approach to loglog-transformed data was considered. The following estimated values for the parameters were obtained: a = exp(-12.5323), b=3.25, s=0.07862. This approach was not successful in solving the common heterogeneity problem of the length-weight data. A generalized nonlinear regression approach to the original data was more suitable in our case. The estimated model was W = 3.83×10-6×L3.238 + ε, with ε~norm(0,0.0281×E[W|L]2×1.242). The estimated 95% confidence interval for b was (3.218, 3.259), and the growth was allometric. The perch from the coastal waters of the Baltic Sea (ICES Subdivision 25) was characterized by slightly better condition than that caught in inland waters and estuaries.

Measure Distributions for Some Poisson Process Random Domains and Statistical Applications

Abstract We define random domains originated by a homogeneous planar Poisson process on that have been never considered before. Distributional results are stated and proved for the Lebesgue measure of the considered domains. Statistical applications are outlined.Abstract We define random domains originated by a homogeneous planar Poisson process on that have been never considered before. Distributional results are stated and proved for the Lebesgue measure of the considered domains. Statistical applications are outlined.