TEMPORAL CHANGES IN LENGTH-WEIGHT RELATIONSHIPS OF SCIAENIDAE (PISCES: TELEOSTEI) SPECIES IN SOUTH BRAZIL

This study reports the importance to evaluate the length-weight relationships (LWR) across the years. We evaluate the LWR for 8 Sciaenidae species of Paranaguá Estuarine Complex, South Brazil, sampled between 2016 and 2018 by bottom trawls similar to the used by artisanal fisheries in this region. There were differences between growth type among the years for 5 species, and all species showed differences in the slope of LWR in at least one year. These results show the importance of fauna and fisheries monitoring programs to better evaluate the population dynamics and fisheries stocks. Keywords: estuarine fish, fisheries biology, marine fish, sciaenid, weight-length relationship

Seasonal Changes of Length-Weight Relationships and Condition Factor of Three Fish Species from the Tanoe-Ehy Swamp Forest (Côte d’Ivoire)

Aims: The Tanoe-Ehy swamp forest (TESF) is a freshwater swampy area characterized by seasonal variation of environmental parameters and fish diversity. So, the aim of this study was to analyze seasonal variations of growth parameters and condition factors of the three abundant species. Methodology: Specimens were collected by using gill nets and fyke nets, measured and weighed. Length-weight relationship (LWR), Fulton’s condition (KF) and relative condition (KR) factors were analyzed from Standard Length (SL) and body weight (BW). Results: The Standard Length of Clarias buettikoferi, Thysochromis ansorgii and Parachana obscura varied between 9.50 and 29.30 cm, 4.60 and 11.50 cm, 10.70 and 29.30 cm, respectively. The growth type of population was allometric negative for C. buettikoferi and P. obscura and isometric for T. ansorgii. In terms of seasonal variation, C. buettikoferi females and P. obscura specimens exhibited isometric growth in dry seasons (DS) against a negative allometric growth in flooded seasons (FS). In contrast, female and combined sex specimens of T. ansorgii showed positive allometric growth in DS and isometric growth type in FS. KR varied between 0.76 and 2.02 and was significantly higher in FS than in DS, indicating a state of well-being during flooded seasons in the 3 species. Conclusion: There was a significant relationship between length with weight and both condition factor for the three species. This study provided the first data about fish body measurements in the TESF and concluded that LWRs and condition factors of the three fish species were strongly influenced by seasonal variations in hydrological conditions.

Evaluation of tomato phenological stages passing on multilevel installations «Fitopiramida»

Relevance. Multilevel pipe vegetation installations (MVTU) “Fitopiramida” are designed for hydroponic cultivation of different agricultural crops including tomatoes.Methods. To create F1 tomato hybrids for this technology the assessment of phenological stages passing of tomato lines on “Fitopiramida” MVTU was carried out. 19 breeding lines including 9 cherry tomato lines, 10 large-fruited tomato lines of indeterminate and determinate growth types were tested. These lines were used in various hybridization schemes to obtain F1 tomato heterotic hybrids for “Fitopiramida”.Results. According to the results of the conducted researches in conditions of low-volume technology “Fitopiramida” duration of periods “germination – beginning of flowering” ("G-BF") and “germination – beginning of ripening” ("G-BR") is significantly reduced. In cherry group lines “G-BR” period is shorter by 17.7 days at average, in large-fruited lines by 23-27.3 days at average depending on growth type. The difference in ripening time is more expressed in largefruited lines; border-grown Kb 183 line began ripening 35 days later. Shorter growing season makes it possible to carry out largest number of crop rotations per year to obtain maximum yield per area unit (in full year use greenhouses). Similar results were obtained in the tests of tomato varieties and F1 hybrids on “Fitopiramida” MWTU in 2019-2020 in terms of phenological stages passing acceleration and earlier fruiting of hydroponic grown tomatoes.

Relative Growth and Size Structure of Achelous spinicarpus Stimpson, 1871 Associated with Shrimp Trawling in the State of Veracruz

The objective was to analyse the relative growth and size structure of Achelous spinicarpus associated with trawling in Veracruz. The organisms came from shrimp trawls carried out in July 2013. There were 45 trawls organized in two depth intervals (B: 22 to 46 m and C: >46 m) and 14 fishing quadrants. Abundance, mean and standard deviation, by sex and depth interval, and sex ratio were determined. An ANOVA was applied to compare CW means, depth intervals and fishing quadrants. The CW-weight relationship was obtained, and growth type was also determined. Length-frequency analyses were carried out. A total of 2377 crabs were collected, 1164 males and 713 females. The overall average CW was 3.65 ± 0.7677 cm, the minimum value was 1.50 cm, and the maximum was 6.00 cm. For males, the average CW was 3.65 ± 0.8242 cm, with1.50 cm minimum value and 6.00 cm maximum value. The average CW of females was 3.64 ± 0.6164 cm, with 1.60 cm minimum value and 5.90 cm maximum value. There were no statistically significant differences in CW between males and females. However, there were significant differences between depth intervals (B and C) for the total and sex CW data. The sex ratio was 2.94:1 and 2.05:1 for depth intervals B and C, and 2.33:1 for the total data set. Growth type was allometric negative for both sexes and overall, with significant differences in slopes between sexes. There was a unimodal pattern for the two fishing depth intervals and for each sex; crabs were between 2.40 and 4.00 cm (77.64%) and between 2.56 and 5.12 (91.12%) for the B and C intervals, respectively. In males, 88.46% were between 2.40 and 4.80 cm, and 90.46% of females were between 2.72 and 4.64 cm. Achelous spinicarpus is an essential species in the structure of the brachyuran assemblage and in benthic communities, as well as a food resource for various species of demersal fish. Thus, the present study provides information on the population subjected to the impact of fishing activity in the area, allowing comparisons between different populations in the species’ area of distribution.

Radiomic Features of Multi-ROI and Multi-Phase MRI for the Prediction of Microvascular Invasion in Solitary Hepatocellular Carcinoma

ObjectivesTo develop and validate an MR radiomics-based nomogram to predict the presence of MVI in patients with solitary HCC and further evaluate the performance of predictors for MVI in subgroups (HCC ≤ 3 cm and > 3 cm).Materials and MethodsBetween May 2015 and October 2020, 201 patients with solitary HCC were analysed. Radiomic features were extracted from precontrast T1WI, arterial phase, portal venous phase, delayed phase and hepatobiliary phase images in regions of the intratumoral, peritumoral and their combining areas. The mRMR and LASSO algorithms were used to select radiomic features related to MVI. Clinicoradiological factors were selected by using backward stepwise regression with AIC. A nomogram was developed by incorporating the clinicoradiological factors and radiomics signature. In addition, the radiomic features and clinicoradiological factors related to MVI were separately evaluated in the subgroups (HCC ≤ 3 cm and > 3 cm).ResultsHistopathological examinations confirmed MVI in 111 of the 201 patients (55.22%). The radiomics signature showed a favourable discriminatory ability for MVI in the training set (AUC, 0.896) and validation set (AUC, 0.788). The nomogram incorporating peritumoral enhancement, tumour growth type and radiomics signature showed good discrimination in the training (AUC, 0.932) and validation sets (AUC, 0.917) and achieved well-fitted calibration curves. Subgroup analysis showed that tumour growth type was a predictor for MVI in the HCC ≤ 3 cm cohort and peritumoral enhancement in the HCC > 3 cm cohort; radiomic features related to MVI varied between the HCC ≤ 3 cm and HCC > 3 cm cohort. The performance of the radiomics signature improved noticeably in both the HCC ≤ 3 cm (AUC, 0.953) and HCC > 3 cm cohorts (AUC, 0.993) compared to the original training set.ConclusionsThe preoperative nomogram integrating clinicoradiological risk factors and the MR radiomics signature showed favourable predictive efficiency for predicting MVI in patients with solitary HCC. The clinicoradiological factors and radiomic features related to MVI varied between subgroups (HCC ≤ 3 cm and > 3 cm). The performance of radiomics signature for MVI prediction was improved in both the subgroups.

Increasing population density reduces soybean yield components and productivity

Studies addressing the interaction of different spatial arrangement in soybean are needed in order to achieve management that leads to higher grain yield associated with rational seed use. The objective of this work was to evaluate the yield components and productivity of an undetermined growth type soybean as a function of different row spacing and plant densities. The treatments consisted of three row spaces (0.25, 0.35 and 0.45 m) and three plant population densities (30, 40 and 50 plants/m²). There was no interaction of row spaces and plant population on soybean yield. Regarding the overall spacing average, the grain yield of the population of 30/m² plants was higher than the productivity of the populations of 40 and 50/m² plants. The largest populations reduce plant sizes due to greater competition between plants. In addition, smaller populations promote higher individual plant yields due to the increase components of the production. This characteristic is defined as the ability of the plant to change its morphology and yield components in order to adapt to the conditions imposed by the spatial arrangement.

Growth parameters of Brycinus longipinnis (Günther, 1864) from the Aghien Lagoon (South East of Côte D’ivoire)

The growth of Brycinus longipinnis caught at Aghien Lagoon was studied between June 2014 and May 2015 through growth type, condition factor and growth parameters according to the Von Bertalanffy model. Sampling was conducted using experimental fisheries. Growth type was determined from the length-weight relationship and growth parameters according to the Von Bertalanffy model from the FiSAT software. The growth was of negative allometric type (b = 2.59). The Brycinus longipinnis population grows faster towards the asymptotic length ((L∞ = 92.40 mm SL) with a growth coefficient K of 0.36 year-1. It is also a long-lived fish species with maximum longevity (tmax) of 8.32 years.

General nucleation-growth type kinetic models of nanoparticle formation: possibilities of finding analytical solutions

In this work, analytical solutions for the time dependences for the concentration of each chemical species are determined in a class of nucleation-growth type kinetic models of nanoparticle formation. These models have an infinitely large number of dependent variables and describe the studied process without approximations. Symbolic solutions are found for the mass kernel (where reactivity is directly proportional to the mass of a nanoparticle) and the diffusion kernel (where reactivity is independent of the size of the nanoparticle). The results show that the average particle size is primarily determined by the type of the kernel function and the ratio of the rate constants of spontaneous nucleation and particle growth. The final distribution of nanoparticle sizes is a continuously decreasing function in each studied case. Furthermore, the time dependences of the concentrations of monomeric units show the induction behavior that has already been observed in many experimental studies.