Integrated rearing system proposal for Cantareus aspersus in experimental orchards: Growth models

2021 ◽  
pp. 002367722110439
Author(s):  
Anton Garcia ◽  
Cecilio Barba ◽  
Manuel Aragón ◽  
Jose M León ◽  
Carmen De-Pablos-Heredero ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Growth Models ◽  
Animal Experimentation ◽  
Quadratic Model ◽  
Natural Behaviour ◽  
Rearing Conditions ◽  
Rearing Density ◽  
Cantareus Aspersus ◽  
Best Fit ◽  
Commercial Size

An integrated rearing system for Cantareus aspersus under environmental conditions in an experimental orchard is proposed. In this study, the natural behaviour, circadian rhythms and suitable rearing conditions of the edible snail were optimised to produce homogeneous growth and low variability. The growth was standardised, and growth pattern fit was assessed with various models. One thousand fry were cultured in the orchard, and a random sample of 100 snails were measured weekly for 23 weeks. The rearing system had the following characteristics: snails and earthworms were included in the experimental rearing orchard; a homogeneous group of juvenile snails of the same age and size and high rearing density (500 snails/m2) was used; snails were fed with layers mash ad libitum; and mixed and fringes vegetation was planted in the orchard. A commercial size of 60% of snails was achieved in 21 weeks and 95% in 23 weeks. The different models showed a good fit, and the quadratic model obtained the best fit. This experimental snail orchard proposal can be extended to other areas, although it must be corrected according to different environmental conditions and fit to other species of interest. This experimental model could constitute a viable alternative to traditional models of animal experimentation with mammals, and given its high adaptability, it could be applied in different fields of science.

scholarly journals Prediction of Mold Spoilage for Soy/Polyethylene Composite Fibers

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Chinmay Naphade ◽  
Inyee Han ◽  
Sam Lukubira ◽  
Amod Ogale ◽  
James Rieck ◽  
...  
Keyword(s):  
Growth Models ◽  
Storage Period ◽  
Weibull Model ◽  
Mold Growth ◽  
Growth Data ◽  
Final Model ◽  
Polyethylene Composite ◽  
Interaction Term ◽  
Environmental Temperatures ◽  
Best Fit

Mold spoilage was determined over 109 days on soy/PE fibers held under controlled temperatures (T) ranging from 10°C to 40°C and water activities(aw)from 0.11 to 0.98. Water activities were created in sealed containers using saturated salt solutions and placed in temperature-controlled incubators. Soy/PE fibers that were held at 0.823awor higher exhibited mold growth at all temperatures. As postulated, increased water activity (greater than 0.89) and temperature (higher than 25°C) accelerated mold growth on soy/PE fibers. A slower mold growth was observed on soy/PE fibers that were held at 0.87awand 10°C. A Weibull model was employed to fit the observed logarithmic values ofT, aw, and an interaction termlog⁡T×log⁡awand was chosen as the final model as it gave the best fit to the raw mold growth data. These growth models predict the expected mold-free storage period of soy/PE fibers when exposed to various environmental temperatures and humidities.

Field calibration of a soil sulfate test on sward lucerne on the eastern Darling Downs, Queensland

1981 ◽  
Vol 21 (110) ◽  
pp. 303 ◽  
Author(s):  
PJ White ◽  
MJ Whitehouse ◽  
LA Warrell ◽  
PR Burrill
Keyword(s):  
Soil Water ◽  
Chloride Concentration ◽  
Relative Yield ◽  
Quadratic Model ◽  
Square Root ◽  
Relative Importance ◽  
Water Suspension ◽  
Field Calibration ◽  
Best Fit ◽  
Soil Level

The relation between phosphate-extractable sulfate and the response of lucerne to applied sulfur was examined on 20 established lucerne (Medicago sativa) swards on the black earths of the Darling Downs. Two rates of S were used (0.100 kg ha-1) and soil depths to 90 cm were considered. Six sites responded at the first cut and relative yield of lucerne was correlated with soil sulfate. The best fit of the data was obtained using a square root quadratic model and sulfate in the 0-80 cm zone. The critical soil level was 3.5 ppm. Of 17 attributes examined, only chloride concentration (0-60 cm) and conductivity of the soil water suspension (0-60 cm) significantly improved the variance in relative yield explained, but this was considered to be fortuitous. The relative importance of sub-soil sulfate (40-80 cm) to lucerne nutrition on these soils is shown.

scholarly journals Incorporating temporal heterogeneity in environmental conditions into a somatic growth model

2017 ◽  
Vol 74 (3) ◽  
pp. 316-326 ◽  
Author(s):  
M.C. Dzul ◽  
C.B. Yackulic ◽  
J. Korman ◽  
M.D. Yard ◽  
J.D. Muehlbauer
Keyword(s):  
Food Availability ◽  
Growth Model ◽  
Environmental Conditions ◽  
Colorado River ◽  
Growth Models ◽  
Somatic Growth ◽  
Environmental Data ◽  
Fish Growth ◽  
Positive Temperature ◽  
Environmental Controls

Evaluating environmental effects on fish growth can be challenging because environmental conditions may vary at relatively fine temporal scales compared with sampling occasions. Here we develop a Bayesian state-space growth model to evaluate effects of monthly environmental data on growth of fish that are observed less frequently (e.g., from mark–recapture data where time between captures can range from months to years). We assess effects of temperature, turbidity, food availability, flow variability, and trout abundance on subadult humpback chub (Gila cypha) growth in two rivers, the Colorado River (CR) and the Little Colorado River (LCR), and we use out-of-sample prediction to rank competing models. Environmental covariates explained a high proportion of the variation in growth in both rivers; however, the best growth models were river-specific and included either positive temperature and turbidity duration effects (CR) or positive temperature and food availability effects (LCR). Our approach to analyzing environmental controls on growth should be applicable in other systems where environmental data vary over relatively short time scales compared with animal observations.

Prediction of dry matter accumulation in bitter vetch

2017 ◽  
Author(s):  
Ufuk Karadavut ◽  
Adil Bakoglu ◽  
Halit Tutar ◽  
Kagan Kokten ◽  
Hava Seyma Yilmaz
Keyword(s):  
Growth Models ◽  
Block Design ◽  
Coefficient Of Determination ◽  
Dry Matter Accumulation ◽  
Randomized Block Design ◽  
Bitter Vetch ◽  
Best Fitting ◽  
Local Genotypes ◽  
Best Fit ◽  
Different Sources

This study was carried out in Bingol province on eastern Anatolian Region between 2013 and 2015. In this study, we obtained 14 bitter vetch genotypes from different sources. The experiment was carried our in three replications in randomized block design. Each plant was weekly measured for 6 weeks starting from germination. For each plant, plant height, fresh and dry stem weight, fresh and dry leaf weights were determined. Logistic, Richards and Weibull growth models were fitted to describe the growth pattern of the genotypes. The best fitting model criteria used were coefficient of determination and mean squared. Richards’s growth model was found to best fit the data for most of the genotypes. Logistic model was the worst fit. In Turkey, climate and soil properties have very large variations. For this, local genotypes showed large variation according to plating areas. YEREL LICE genotype showed more stable and it is the height identified all growth models than other local genotypes. However, IFVE 2923 SEL and IFVE 2977 SEL 2802 these genotypes gave positive results in different environmental conditions.

scholarly journals Some Clarifications Regarding Literature on Atmospheric Corrosion of Weathering Steels

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
I. Díaz ◽  
H. Cano ◽  
B. Chico ◽  
D. de la Fuente ◽  
M. Morcillo
Keyword(s):  
Corrosion Rate ◽  
Environmental Conditions ◽  
Atmospheric Corrosion ◽  
Research Work ◽  
Rust Layer ◽  
Morphology And Structure ◽  
Time Of Wetness ◽  
Best Fit

Extensive research work has thrown light on the requisites for a protective rust layer to form on weathering steels (WSs) in the atmosphere, one of the most important is the existence of wet/dry cycling. However, the abundant literature on WS behaviour in different atmospheres can sometimes be confusing and lacks clear criteria regarding certain aspects that are addressed in the present paper. What corrosion models best fit the obtained data? How long does it take for the rust layer to stabilize? What is the morphology and structure of the protective rust layer? What is an acceptable corrosion rate for unpainted WS? What are the guideline environmental conditions, time of wetness (TOW), SO2, and Cl−, for unpainted WS? The paper makes a review of the bibliography on this issue.

scholarly journals Age, growth, and maturity of the whitebrow skate, Bathyraja minispinosa, from the eastern Bering Sea

2011 ◽  
Vol 68 (7) ◽  
pp. 1426-1434 ◽  
Author(s):  
Shaara M. Ainsley ◽  
David A. Ebert ◽  
Gregor M. Cailliet
Keyword(s):  
Bering Sea ◽  
Growth Models ◽  
Gompertz Model ◽  
Parameter Estimates ◽  
Population Declines ◽  
Age At Maturity ◽  
Von Bertalanffy Model ◽  
Eastern Bering Sea ◽  
Best Fit ◽  
The Bering Sea

Abstract Ainsley, S. M., Ebert, D. A., and Cailliet, G. M. 2011. Age, growth, and maturity of the whitebrow skate, Bathyraja minispinosa, from the eastern Bering Sea. – ICES Journal of Marine Science, 68: 1426–1434. Skates are a common bycatch in groundfish fisheries in the Bering Sea; however, their life-history characteristics are not well known. The study is the first to investigate the age, growth, and age at maturity of Bathyraja minispinosa. Ages were estimated using sectioned vertebrae and several growth models were compared. The Gompertz model was the best fit and no significant differences were detected between sexes for any model. The maximum age estimated was 37 years, and parameter estimates generated from the three-parameter von Bertalanffy model were k = 0.02 year−1 and L∞ = 146.9 cm total length (TL). Males reached their size at 50% maturity larger than females (70.1 and 67.4 cm, respectively), but no significant differences in the estimated size or age at maturity were found. Whereas B. minispinosa is smaller than many skate species in the eastern Bering Sea, it has a considerably longer estimated lifespan, indicating that size may not be a reliable method of estimating the vulnerability of a rajid species to population declines in the eastern North Pacific.

scholarly journals Emergent Rarity Properties in Carabid Communities From Chinese Steppes With Different Climatic Conditions

2021 ◽  
Vol 9 ◽  
Author(s):  
Noelline Tsafack ◽  
Paulo A. V. Borges ◽  
Yingzhong Xie ◽  
Xinpu Wang ◽  
Simone Fattorini
Keyword(s):  
Community Structure ◽  
Environmental Conditions ◽  
Large Scale ◽  
Species Abundance ◽  
Climatic Conditions ◽  
Carabid Beetles ◽  
Model Parameters ◽  
Desert Steppe ◽  
Best Fit ◽  
Scale Of Analysis

Species abundance distributions (SADs) are increasingly used to investigate how species community structure changes in response to environmental variations. SAD models depict the relative abundance of species recorded in a community and express fundamental aspects of the community structure, namely patterns of commonness and rarity. However, the influence of differences in environmental conditions on SAD characteristics is still poorly understood. In this study we used SAD models of carabid beetles (Coleoptera: Carabidae) in three grassland ecosystems (desert, typical, and meadow steppes) in China. These ecosystems are characterized by different aridity conditions, thus offering an opportunity to investigate how SADs are influenced by differences in environmental conditions (mainly aridity and vegetation cover, and hence productivity). We used various SAD models, including the meta-community zero sum multinomial (mZSM), the lognormal (PLN) and Fisher’s logseries (LS), and uni- and multimodal gambin models. Analyses were done at the level of steppe type (coarse scale) and for different sectors within the same steppe (fine scale). We found that the mZSM model provided, in general, the best fit at both analysis scales. Model parameters were influenced by the scale of analysis. Moreover, the LS was the best fit in desert steppe SAD. If abundances are rarefied to the smallest sample, results are similar to those without rarefaction, but differences in models estimates become more evident. Gambin unimodal provided the best fit with the lowest α-value observed in desert steppe and higher values in typical and meadow steppes, with results which were strongly affected by the scale of analysis and the use of rarefaction. Our results indicate that all investigated communities are adequately modeled by two similar distributions, the mZSM and the LS, at both scales of analyses. This indicates (1) that all communities are characterized by a relatively small number of species, most of which are rare, and (2) that the meta-communities at the large scale maintain the basic SAD shape of the local communities. The gambin multimodal models produced exaggerated α-values, which indicates that they overfit simple communities. Overall, Fisher’s α, mZSM θ, and gambin α-values were substantially lower in the desert steppe and higher in the typical and meadow steppes, which implies a decreasing influence of environmental harshness (aridity) from the desert steppe to the typical and meadow steppes.

scholarly journals Selecting the best growth model for elasmobranches

2015 ◽  
Author(s):  
Kwang-Ming Liu ◽  
Chiao-Bin Wu ◽  
Shoou-Jeng Joung ◽  
Wen-Pei Tsai
Keyword(s):  
Growth Model ◽  
Growth Models ◽  
Stock Assessment ◽  
Gompertz Model ◽  
Information Criterion ◽  
Age And Growth ◽  
Deep Waters ◽  
Extended Longevity ◽  
Best Fit ◽  
Two Parameter

Age and growth information is essential for accurate stock assessment of fish, and growth model selection may influence the result of stock assessment. Previous descriptions of the age and growth of elasmobranches relied mainly on the von Bertalanffy growth model (VBGM). However, it has been noted that sharks, skates and rays exhibit significant variety in size, shape, and life-history traits. Given this variation, the VBGM may not necessarily provide the best fit for all elasmobranches. This study attempts to improve the accuracy of age estimates by testing four growth models—the VBGM, two-parameter VBGM, Robertson (Logistic) and Gompertz models—to fit observed and simulated length-at-age data for 37 species of elasmobranches. The best growth model was selected based on corrected Akaike’s Information Criterion (AICc), the AICc difference, and the AICc weight. The VBGM and two-parameter VBGM provide the best fit for species with slow growth and extended longevity (L∞ > 100 cm TL, 0.05 < k < 0.15 yr-1), such as pelagic sharks. For fast-growing small sharks (L∞ < 100 cm TL, kr or kg > 0.2 yr-1) in deep waters and for small-sized demersal skates/rays, the Robertson and the Gompertz models provide the best fit. The best growth models for small sharks in shallow waters are the two-parameter VBGM and the Robertson model, while all the species best fit by the Gompertz model are skates and rays.

scholarly journals Flooding Reduces Gas Exchange and Growth in Snap Bean

HortScience ◽  
1991 ◽  
Vol 26 (4) ◽  
pp. 372-373 ◽  
Author(s):  
Bharat P. Singh ◽  
Kevin A. Tucker ◽  
James D. Sutton ◽  
Harbans L. Bhardwaj
Keyword(s):  
Gas Exchange ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Quadratic Model ◽  
Snap Bean ◽  
Blue Lake ◽  
Relationship Of ◽  
The Relationship ◽  
Best Fit ◽  
Prior Stress

This study was conducted to determine the effect of various flooding durations on the growth, water relations, and photosynthesis of the snap bean (Phaseolus vulgaris L.). Greenhouse-grown plants of cv. Blue Lake 274 were flooded for 0 (control), 1, 3, 5, or 7 days. Leaf water potential (ψ), stomatal conductance (gs), transpiration (E), and net photosynthesis (Pn) were measured at the completion of the flooding period and after recovery for 7 days. Root, stem, and leaf dry weights were recorded after plants were allowed to recover from the flooding stress for 7 days. The values for ψ, gs, E, and Pn decreased quadratically with the increase in the duration of flooding. The Pn of plants flooded for 1 day was 17% lower than that of the control and it reached near zero in plants flooded for 7 days. The decrease in Pn after 1 day of flooding was not associated with ψ or gs; however, for longer duration of flooding, Pn decline coincided with the decline in gs. A week after the cessation of flooding, the level of recovery in ψ, E, and Pn was linear and that in gs quadratic to the duration of prior stress experienced by the plant. However, after recovering for 7 days, none of the flooded plants regained gas exchange activities at par with the control. The relationship of stem dry weight to duration of flooding was linear, while a quadratic model provided the best fit for the regression of root and leaf dry weight on the number of days of flooding. Overall, even 1 day of flooding reduces photosynthesis in snap bean and causes a decrease in dry weight of the plant. the extent of decrease in both increasing with the duration of flooding.

scholarly journals High frequency of social polygyny reveals little costs for females in a songbird

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Simone Santoro ◽  
Pilar Fernández-Díaz ◽  
David Canal ◽  
Carlos Camacho ◽  
László Z. Garamszegi ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Survival Rates ◽  
Central Spain ◽  
Pair Bonds ◽  
Rearing Conditions ◽  
Capture Recapture ◽  
Males And Females ◽  
The Difference ◽  
The Cost

AbstractMating system theory predicts that social polygyny—when one male forms pair bonds with two females—may evolve by female choice in species with biparental care. Females will accept a polygynous male if the benefit of mating with a male providing high-quality genes or rearing resources outweighs the cost of sharing mate assistance in parental care. Based on this rationale, we hypothesise that the population frequency of social polygyny (FSP) varies due to changes in mate sharing costs caused by changing environmental conditions. We predicted that: (1) polygamous females (i.e. mated with a polygynous male) pay a survival cost compared to monogamous females; (2) FSP would be higher in years with better rearing conditions and (3) the difference in survival rates between monogamous and polygamous females would be small following years with higher FSP. We tested these predictions using regression and multistate analyses of capture-recapture data of pied flycatchers, Ficedula hypoleuca, in central Spain collected over 26 years (1990–2016). Monogamous females had a higher mean survival rate than polygamous females (prediction 1), but there was no difference in survival between polygynous and monogamous males. In addition, FSP was positively associated with annual reproductive success (a proxy of the quality of rearing conditions—prediction 2). Finally, following years with high FSP, the survival of polygamous females was similar to that of monogamous females (prediction 3), while the chance of breeding in a polygamous state for 2 years in a row increased for both males and females. Our findings suggest that fluctuating environmental conditions may be a necessary but neglected aspect of understanding social polygyny mechanisms.

Sign in / Sign up

Export Citation Format

Share Document