Over‐dispersed count data in crop and agronomy research

While evaluating plant response to biotic or abiotic stress and genotype–environment interactions and searching causes of yield gap, very often are observed data with non‐normal distributions. One of the commonly encountered types of variables with a non‐normal distribution is count data. Count data are defined as the type of observations which have a positive, non‐zero, integer value. The selection of appropriate probability distributions and model types is very important due to the risk of estimating the variance incorrectly—the phenomenon of over‐dispersion. Increasingly, biologists and agronomists have been using methods based on generalized linear models. However, sometimes, when including count data, they are not aware of or disregard their over‐dispersion. One of the solutions for over‐dispersed count data is to use probability distributions and model types which assume a more flexible mean and variance relationship. Thus, the aim of this study is to present various ways of assessing over‐dispersion. Additionally, we present alternative distributions and discuss other approaches to solve the problem of over‐dispersion in count data sets. As examples in this study are used real data sets from different agricultural experiments. In our study, in one out of the two data sets used, this phenomenon occurred. Thus, in the analysis of count data, instead of using default distribution (usually Poisson distribution), other distributions should be considered because of the possible occurrence of over‐dispersion. We also observed that there is not one universal distribution to use and each data set might need a separate assessment to choose its distribution. For an efficient and proper count data analysis, with potential over‐dispersion, it is important to explore several options, i.e. evaluate models with an alternative to Poisson probability distributions and then make an informed choice.     

Effect of Replacing Cocoa Powder by Carob Powder in the Muffins on Sensory and Physicochemical Properties

The increasing demand for cocoa and search for ingredients rich in bioactive compounds encouraged us to investigate the possibility of replacing it by carob powder in the muffins containing soy beans, sesame oil and flaxseeds. There was 5% addition of carob or cocoa powder to the individual doughs. The muffins with the addition of carob were characterized by improved antiradical activity (by 36% - 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) method, by 83% - 2,2-diphenyl-1-picrylhydrazyl (DPPH) method), higher content of genistein (18%) and total phytosterols (17%) in the dry mass. The color differences in the carob muffins crusts were not perceptible by consumers (ΔE?=?0.70 for crust, ΔE?=?5.6 for crumb) and their taste was found to be less bitter and sweeter than the taste of cocoa muffins. Moreover, the addition of carob powder as well as cocoa powder resulted in good sensory quality. The high content of phytosterols, genistein and improved antiradical properties proved carob to be a source of bioactive compounds. The results show that carob powder may be used as valuable alternative muffin ingredient to cocoa.     

Community structure of Lumbricidae in beech woodland of the Bieszczady National Park, Southeast Poland

As ecosystem engineers, earthworms play a key role in the soil environment. However, due to increasing anthropogenic pressure, soil organisms,including earthworms, are being threatened by habitat loss. In this study, we undertook a qualitative and quantitative investigation of earthworms of the family Lumbricidae in four types of Carpathian beech woodland(Fagetum carpaticum), characterized by their understory vegetation(I, F. c. festucetosum drymejae; II, F. c. typicum; III, F. c. lunarietosum; and IV, F. c. allietosum), in the Bieszczady National Park(Eastern Carpathians, Southeast Poland). At each investigated site, soil monoliths(25 cm × 25 cm × 25 cm) were examined by hand sorting. Earthworms were expelled from deep soil layers using a weak formalin solution(0.4%). Depending on the phytocoenosis, 7 species of Lumbricidae were identified at each of the sites I, II, and III and 10 at site IV. Site IV(F. c. allietosum) differed significantly(P 0.05) from the other three sites with respect to earthworm biomass(59.71 ± 39.53 g m~(-2))and the Shannon-Wiener diversity index(0.52 ± 0.12). Although present three decades ago, the deep-burrowing species Octodrilus transpadanus and the litter-dwelling species Dendrobaena octaedra were not found at site IV in the present study. We suspect that these two species may have been displaced by the invasive Lumbricus terrestris, which was not found at the same site in the 1980 s. Such observations warrant further investigation to verify the predicted effects of an invasive earthworm, including the potential effects on soils and other fauna and flora, which have been documented in numerous countries.     

Plastic and moldable metals by self-assembly of sticky nanoparticle aggregates

Deformable, spherical aggregates of metal nanoparticles connected by long-chain dithiol ligands self-assemble into nanostructured materials of macroscopic dimensions. These materials are plastic and moldable against arbitrarily shaped masters and can be thermally hardened into polycrystalline metal structures of controllable porosity. In addition, in both plastic and hardened states, the assemblies are electrically conductive and exhibit Ohmic characteristics down to approximately 20 volts per meter. The self-assembly method leading to such materials is applicable both to pure metals and to bimetallic structures of various elemental compositions.     

The effect of road traffic on a breeding community of woodland birds

The very rapid development of the road infrastructure in recent years has adversely affected the natural environment. The main effects of this have been the loss or deteriorating quality of habitats, the mortality of animals due to collisions with road vehicles, the withdrawal of birds as a result of disturbance and excessive noise in the neighbourhood of roads. In this study, we attempted to define the influence of a busy road on a breeding community of woodland birds. Individuals were counted using the point method at 54 observation points located at three various distances (60, 310, 560 m) from the road. At each point, we determined the habitat parameters and the intensity of noise. In total, 995 individuals of 39 species were recorded on the study plot. This study showed that the area was homogeneous with respect to habitat. The number of birds per point increased with distance from the road. Species diversity was lower near the road. The density of nine common species increased with distance from the road. Great Tit Parus major and Song Thrush Turdus philomelos preferred the neighbourhood of the road, whereas the numbers of the other species were the highest in the middle row of points. The number and species diversity of birds were correlated with the pattern of sound propagation across our study area. Our results showed that the species particularly sensitive to road traffic were those nesting near the ground and with low-frequency calls.     

Influence of water salinity on the survival of embryos and growth of the sichel larvae Pelecus cultratus (L.) under controlled conditions

The purpose of this study was to analyse the influence of water salinity on the incubation of eggs and growth of the larvae of sichel Pelecus cultratus (L.) under controlled conditions. The following water salinity was considered: 3, 6, 9, 12, 15 and 0 ppt for the control. The eggs incubation time depended on the water salinity, lasting from 56.3°D [9 ppt] to 107.7°D [0 ppt]. The higher water salinity, shorter the incubation time. The highest survivability of larvae was obtained in water of the salinity equal 3 ppt and in freshwater, where respectively 87% and 84% of the larvae survived. No hatched larvae were obtained in water of the salinity of 12 and 15 ppt, as all embryos died during the experiment. Larvae were reared up for 21 days. The final body weight, depending on the water salinity, reached from 43.5 mg [9 ppt] to 74.6 mg [3 ppt], at the respective body lengths of 19.3 mm and 23.2 mm. The highest body gains and lengths of larvae were observed in water of the salinity of 3 ppt. The lowest survivability of sichel larvae occurred in water of the salinity 9 ppt, where it was only 53.2%. The survivability of larvae in freshwater and water of the salinity of 3 ppt was quite similar: 96.2% and 95.6% respectively. Water salinity degree of 12 and 15 ppt appeared to be lethal for both embryos and larvae of the sichel.     

Breaking wheat yield barriers requires integrated efforts in developing countries

Most yield progress obtained through the so called "Green Revolution", particularly in the irrigated areas of Asia, has reached a limit, and major resistance genes are quickly overcome by the appearance of new strains of disease causing organisms.New plant stresses due to a changing environment are difficult to breed for as quickly as the changes occur.There is consequently a continual need for new research programs and breeding strategies aimed at improving yield potential, abiotic stress tolerance and resistance to new, major pests and diseases.Recent advances in plant breeding encompass novel methods of expanding genetic variability and selecting for recombinants, including the development of synthetic hexaploid, hybrid and transgenic wheats.In addition, the use of molecular approaches such as quantitative trait locus(QTL) and association mapping may increase the possibility of directly selecting positive chromosomal regions linked with natural variation for grain yield and stress resistance.The present article reviews the potential contribution of these new approaches and tools to the improvement of wheat yield in farmer's fields, with a special emphasis on the Asian countries, which are major wheat producers, and contain the highest concentration of resource-poor wheat farmers.     

The effects of sage extract feed supplementation on biochemical parameters, weight of internal organs and Salmonella counts in chickens

We investigated the effects of dietary addition of sage extract on the biochemical parameters, weight of some body organs and changes in the counts of Salmonella Enteritidis PT4 (SE) in experimentally infected chickens. The following diets were used: basal diet, basal diet with addition of an extract of Salvia officinalis L. (S), basal diet and SE, and basal diet and S and SE (SSE). Compared to the SE group, sage extract in the SSE group decreased activities of ALP and ALT and concentrations of glucose and bilirubin on the 4th day post inoculation (p.i.). However, on the 18th day p.i., lower levels of bilirubin and ALT activity only were detected. Addition of sage extract to the diets decreased the counts of Salmonella in the liver, spleen and caecum at both sampling times, along with lower production of mucus in the chickens' intestines. Our results suggest that the addition of sage extract to the diet could be effective in protecting SE-infected chickens.     

Restoration of Vegetation in Relation to Soil Properties of Spoil Heap Heavily Contaminated with Heavy Metals

The main objectives of our study were to evaluate soil contamination on a zinc-lead spoil heap in the Upper Silesian Industrial Region in southern Poland using pollution indices, and to investigate the relation between soil properties and the natural succession of vegetation. Organic carbon and nitrogen, pH, soil texture, base cations, and heavy metal content were analyzed in soil samples at depths of 0–15 cm below the organic horizon over a regular grid of 14 sampling plots. The contents of Zn, Pb, and Cd exceeded by several times the acceptable thresholds. Measurements of soil enzyme activity were used to evaluate the progress of vegetation development in relation to soil chemical properties. The results indicate that heavy metals had a significant impact on soil enzyme activity and the development of vegetation cover. High contents of Pb and Cd reduced enzyme activity, while this activity increased with increasing amounts of soil organic matter. Further, the accumulative capacities of heavy metals in needles of Scots pine (Pinus sylvestris L.) and aboveground biomass of bladder campion (Silene vulgaris (Moench) Garcke) were examined. A high accumulation of Zn, Pb, and Cd in the aboveground tissues of S. vulgaris indicated an unusual tolerance of this species to heavy metals and the possibility of using this species in phytoremediation of post-industrial sites.