Application of morphometric measures in estimation of body weight and discrimination of Astyanax lacustris and Astyanax fasciatus

The objective of this study was to verify the direct and indirect correlation between morphometric measures, ratios, body weight and yield in two lambari species Astyanax lacustris and Astyanax fasciatus and whether the discriminant analysis is capable of separating and allocating the species. We used 102 lambari yellow tail and 60 lambari red tail. The fish were weighed and submitted to the evaluation of the morphometric measurements. The direct and indirect effects were evaluated by the method of track analysis, considering weight at slaughter, weight of body parts and body yields as dependent variables and measures and morphometric ratios as explanatory variables. Astyanax lacustris presented higher height and body width, carcass yield and trunk, while A. fasciatus presented higher head yield and viscera weight. The discriminant analysis was able to classify 79.5% of the two species. Track analysis demonstrated that the morphometric measurements can be used for estimation of body and body components’ weight in A. lacustris and A. fasciatus. However, regarding the corporal yield; the morphometric measures were insufficient to explain the yield variations of the species.     

Effectiveness of early-generation testing applied to upland rice breeding

A plant breeding program is a long-term investment. Therefore, periodic assessment of the effectiveness of a breeding strategy is essential to maximize genetic gains per unit of time and resource invested. In this work, we assessed the effectiveness of the early-generation testing (EGT) approach used in the upland rice (Oryza sativa L.) breeding program at Embrapa (Brazilian Agricultural Research Corporation), Brazil, estimating the genetic progress achieved for three traits in two distinct phases, spanning 15 years. In the first phase (from 2003 to 2010), it was used the bulk method within F₃ progenies with prior testing of F₂ crosses, while in the second phase (from 2010 to 2017), it was used the bulk method within F₂ progenies. The dataset comprised 70 yield trials, involving 1884 F_3:5 progenies (phase I) and 925 F_2:4 progenies (phase II) from an elite population, and 10 check cultivars, evaluated for grain yield (GY), plant height (PH) and days to flowering (DTF). For estimating the genetic gain, we adapted a generalized linear regression method to compute bi-segmented linear regression coefficients. Desirable genetic gains were achieved only for GY in both phases of the breeding program, with 78.75 kg ha^?1 year^?1 (2.68%) in the first phase, and 53.78 kg ha^?1 year^?1 (1.54%) in the second phase. These results show the effectiveness of EGT, especially via bulk method within F₃ progenies with prior testing of F₂ crosses, applied to upland rice breeding. Some refinements are discussed in the method to make it more cost-effective and more efficient in achieving genetic gains.     

First feeding of diploid and triploid yellowtail tetra Astyanax altiparanae: An initial stage for application in laboratory studies

In this study, the aim was to establish a protocol for first feeding of diploid and triploid yellowtail tetra Astyanax altiparanae in laboratory conditions. The fry were fed with five different diets: (i) Artemia franciscana nauplii, (ii) plankton, (iii) dry food, (iv) Artemia franciscana nauplii + plankton, and (v) Artemia nauplii + plankton + dry food. Additionally, the growth and survival rates of diploid and triploid individuals were also evaluated. On day 10, the length of the fish between the treatments differed significantly (p = .0001) and ranged from 4.07 ± 0.06 mm (dry food) to 8.50 ± 0.64 mm (plankton + Artemia). The sizes of the fish increased with time, except for the fish fed with dry food. The survival rates were similar for the fish fed with the four diets and ranged from 80.7 ± 5.4% (dry food + plankton + Artemia to 92.0 ± 1.6% (plankton + Artemia), but differed from the fish fed with dry food (17.7 ± 5.8%, p = .0017). Diploids and triploids did not present differences on day 0 (p = .2252) and on day 10 (p = .4844) when the fish presented 6.77 ± 0.25 mm and 6.54 ± 0.15 mm respectively. Survival of diploids (87.3 ± 5.13%) and triploids (74.67 ± 2.30%) were also similar (p = .0285). These data are innovative and useful for establishing protocols for this species in both academic and applied sciences.     

Editorial

Journal of Plant Diseases and Protection -     

Pedotransfer function to predict density of forest soils in Switzerland

Soil density is an important soil property, but respective measurements are usually scarce. With data from 559 mineral soil horizons (134 sites) we developed a linear regression pedotransfer function (PTF) for the density of forest soils (sieved to ≤ 2 mm). The field estimate of density was the most important covariate. RMSE of 0.205 Mg m^?3 and R² of 0.67, calculated on independent data (131 horizons), were better than the statistics obtained by published, recalibrated PTF (RMSE 0.271–0.324 Mg m^?3; R² 0.28–0.42).     

The State‐Level Impacts of Enforcing Sales Taxes for E‐retail Purchases

The Marketplace Fairness Act (S. 743) recently passed by the U.S. Senate may portend a national move toward states imposing sales taxes for business‐to‐consumer e‐retail purchases. While much of the policy debate surrounding this question has focused on trade creation versus diversion, there are likely distinct compositional effects at the state level, which will affect both economic activity and tax revenue. Consumers are clearly hurt by an online sales tax. However, such a policy would seemingly benefit state tax coffers, as well as traditional brick‐and‐mortar retailers and their employees. This paper uses a computable general equilibrium model approach to get a better understanding of the state‐level income, employment, and tax revenue effects of such a policy shift, in particular the likely tradeoffs between these three traditional economic targets across reasonable ranges of price elasticities.     

Effect of Natural Disasters on Local Nonprofit Activity

Disaster damage levels are matched to county‐level nonprofit activity indicators. Using dynamic panel‐data estimation, nonprofit net assets (and nonprofit revenue to a lesser extent) defined at this local level are found to be positively correlated with disaster event damage levels, consistent with a post‐disaster giving mechanism. Magnitudes are relatively small, suggesting a distributed downstream flow of benefits to local nonprofits from larger national organizations. Furthermore, disaster damage at a lag is associated with only minor increases in the count of local nonprofit organizations at the county level. The relative impacts of assets and nonprofit counts in particular indicate that existing nonprofits have the established credibility and networks to be reliable conduits for post‐disaster asset flows. If local nonprofits are an indicator of regional social capital, the findings suggest that disasters reveal the resilience of social capital structures in the face of crisis along the focal dimension of nonprofit activity.     

Importance of hedgerows as habitat corridors for forest plants in agricultural landscapes

Hedgerows have been proposed as habitat and conservation corridor for forest plant species, but their importance for the survival of these species is still not clear. The objective of our study was to examine the frequency of occurrence of forest species and total forest species richness in different parts of the hedgerows, and to relate these patterns of occurrence to the species’ habitat requirements and life history traits. We surveyed in total 130 forest-hedgerow transects in North-western Germany, including three age classes.About 77% of all forest plant species (including some endangered taxa) occurring in the neighbouring forests were also found in the adjacent hedgerows. In all age classes, there was a negative relationship between distance from the forest-hedgerow ecotone and the number of species. Ancient hedgerows were not significantly more species-rich than more recent ones. Within 100 m distance from the forest edge, forest species richness increased with an increasing number of species in the nearby forest and with an increasing cover of the tree canopy as well as a decreasing cover of the shrub layer. Species with high frequency had comparatively high Ellenberg indicator values for light, and were mostly associated with anemochorous and epizoochorous seed dispersal.The frequency of occurrence in hedgerows of species with common attributes was partly in agreement, partly in disagreement with the results obtained in previous studies. We conclude that patterns are difficult to generalize, probably due to a strong regional variation in the pool of forest species and in the specific environments of both forests and hedgerows.