Effects of walnut husk washing waters and their phenolic constituents on horticultural species

INTRODUCTION: The reuse of wastewaters for agricultural purposes is a common practice in many countries and is increasingly recommended by organizations that promote sustainable development. Yet, it is restricted by the potential negative impact of these materials on soil and crops. The aim of this study was therefore to evaluate the environmental impact of walnut husk washing waters (WHWW) and their organic fractions, in order to conceive their agricultural exploitation. DISCUSSION: Phytotoxicity tests and morphological investigations on representative plant species of horticultural interest indicated that WHWW and their organic fractions can elicit a concentration-dependent stimulating effect on the growth of radish, lettuce cv. cavolo Napoli with effects up to 165 %. An opposite inhibitory effect up to 70 % was observed on spinach and lettuce cv. Gentilina. Proapoptotic effects were observed by acridine orange/ethidium bromide assay in the species inhibited by WHWW treatment. High-performance liquid chromatography-mass spectrometry analysis of the WHWW revealed the presence of a main component which was extracted selectively in organic solvents and purified by preparative chromatography. Complete spectral analysis allowed identification as 4,8-dihydroxy-1-tetralone, commonly known as regiolone. Regiolone exhibited the same concentration-dependent activity on root elongation with a stimulation in the case of radish up to 135 % with respect to control. These results open perspectives in the exploitation of WHWW and the main phenolic constituent readily available by a straightforward isolation procedure as a natural fertilizer for specific crops.     

Strengths and weaknesses of microarray approaches to detect Pseudo-nitzschia species in the field

The planktonic diatom genus Pseudo-nitzschia contains several genetically closely related species. Some of these can produce domoic acid, a potent neurotoxin. Thus, monitoring programs are needed to screen for the presence of these toxic species. Unfortunately, many are impossible to distinguish using light microscopy. Therefore, we assessed the applicability of microarray technology for detection of toxic and non-toxic Pseudo-nitzschia species in the Gulf of Naples (Mediterranean Sea). Here, 11 species have been detected, of which at least 5 are potentially toxic. A total of 49 genus- and species-specific DNA probes were designed in silico against the nuclear LSU and SSU rRNA of 19 species, and spotted on the microarray. The microarray was tested against total RNA of monoclonal cultures of eight species. Only three of the probes designed to be species-specific were indeed so within the limits of our experimental design. To assess the effectiveness of the microarray in detecting Pseudo-nitzschia species in environmental samples, we hybridized total RNA extracted from 11 seasonal plankton samples against microarray slides and compared the observed pattern with plankton counts in light microscopy and with expected hybridization patterns obtained with monoclonal cultures of the observed species. Presence of species in field samples generally resulted in signal patterns on the microarray as observed with RNA extracted from cultures of these species, but many a-specific signals appeared as well. Possible reasons for the numerous cross reactions are discussed. Calibration curves for Pseudo-nitzschia multistriata showed linear relationship between signal strength and cell number.     

Soil carbon dynamics in a Mediterranean forest during the Kyoto Protocol commitment periods

The purpose of the present work is to asses the possibility of detecting changes in soil organic carbon (SOC) at the end of the 5-years of the first Commitment Period (CP) of the Kyoto Protocol of the United Nation’s Framework Convention on Climate Change (1 January, 2008–31 December, 2012), by both direct measurement and the use of an opportunely evaluated SOC model, CENTURY. The investigated soil is young, developed since 28 years on virtually C-free spoil banks and under the influence of two managed forest stands, one a mix of English oak (Quercus robur L.) and Italian alder (Alnus cordata Loisel.) and the other pure English oak. The SOC stock of either stand was monitored since the time the stands were planted in 1981, and it was used together with other parameters for the model evaluation, while the future projections for the end of the first (2012) and second (2017) CP were made according to two extreme IPCC climatic scenarios: A1F1, the most dramatic, and B2, among the less impacting. Direct SOC measurements performed at the beginning and at the end of a time frame equivalent to a commitment period (2004–2008) had not shown significant variations in either stands. Compared to the 2008 SOC stock, in both stands the model shows variations at the end of the first CP from 0.7 to 1.8 Mg C ha⁻¹ for the A1F1 scenario and from 0.3 to 1.7 Mg C ha⁻¹ for the B2. These variations are within the standard deviations of the C stocks measured in 2008. On the contrary, at the end of the second CP, the modelled SOC increments range from 2.5 to 3.6 Mg C ha⁻¹ (A1F1) or from 1.9 to 3.4 Mg C ha⁻¹ (B2), indicating the possibility to detect the SOC changes by direct measurement, since the values well agree with the minimum detectable variation estimated for both sites in 3.3–4.5 Mg C ha⁻¹. This work shows that SOC stock changes measured directly in the field can be minimal at the end of both CPs, and that CENTURY well simulates the SOC dynamics of the stands. The use of such a model, validated at long-term experimental sites, hence represents an effective tool for estimating future changes in SOC amounts in support of direct measurements when a short period of time, such as the CP, is considered.     

Investigation of ZnO nanoparticles’ ecotoxicological effects towards different soil organisms

Introduction  

Nanomaterials have widespread applications in several industrial sectors. ZnO nanoparticles (NPs) are among the most commonly used metal oxide NPs in personal care products, coating and paints. However, their potential toxicological impact on the environment is largely unexplored.     

Poliovirus and Other Enteroviruses from Environmental Surveillance in Italy, 2009–2015

Within the initiatives for poliomyelitis eradication by WHO, Italy activated an environmental surveillance (ES) in 2005. ES complements clinical Acute Flaccid Paralysis (AFP) surveillance for possible polio cases, detects poliovirus circulation in environmental sewage, and is used to monitor transmission in communities. In addition to polioviruses, the analyses comprised: (i) the monitoring of the presence of non-polio enteroviruses in sewage samples and (ii) the temporal and geographical distribution of the detected viruses. From 2009 to 2015, 2880 sewage samples were collected from eight cities participating in the surveillance. Overall, 1479 samples resulted positive for enteroviruses. No wild-type polioviruses were found, although four Sabin-like polioviruses were detected. The low degree of mutation found in the genomes of these four isolates suggests that these viruses have had a limited circulation in the population. All non-polio enteroviruses belonged to species B and the most frequent serotype was CV-B5, followed by CV-B4, E-11, E-6, E-7, CV-B3, and CV-B2. Variations in the frequency of different serotypes were also observed in different seasons and/or Italian areas. Environmental surveillance in Italy, as part of the ‘WHO global polio eradication program’, is a powerful tool to augment the polio surveillance and to investigate the silent circulation or the re-emergence of enteroviruses in the population.     

A Myanmar amber cockroach with protruding feces contains pollen and a rich microcenosis

Several hypotheses have been proposed to explain the mechanisms responsible for maintenance of host-specific gentes in the common cuckoo (Cuculus canorus). Some of them expect that when adult cuckoos return to lay their eggs to their natal site (natal philopatry hypothesis) or habitat in which they were reared (habitat-imprinting hypothesis), there is a higher probability of finding nests of the host species by which they were reared. Since published evidence is ambiguous, we here evaluate the natal philopatry and habitat-imprinting hypotheses using information on habitat homogeneity and cross-continental long-term ringing data. We found no evidence for the natal philopatry hypothesis—instead of returning to their natal site, juvenile cuckoos exhibited longer dispersal movements than adults, and the difference was even larger in comparison with a wide array of cuckoo host species. On the contrary, we found support for the habitat-imprinting hypothesis—juvenile cuckoos followed similar levels of natal habitat homogeneity at 5- and 25-km scale when returning to breed in the next years. Our results suggest that preference for the particular habitat structures may help cuckoos to find appropriate hosts.

     

EU vision of sustainable agriculture,land use,forestry and management of natural resources – level of the Slovak state administration convergence to the EU requirements

The EU vision of sustainable agriculture, land use, forestry and management of natural resources contributes to the balanced exploitation of the environment, taking into account rural development strategy. Whilst the EU directs activities through legislative tools, national systems of public administration are responsible for the implementation of the respective laws. Despite there not being acquis communautaire in public administration, non-formal cooperation has nevertheless emerged and systems of national public administration have to meet EU criteria and ensure the effective implementation of legislation. The paper presents an analysis of how Slovak state administration has converged with EU requirements in the field of sustainable agriculture, land use, forestry and natural resources. Administrative convergence is considered through the internal convergence represented by capacities without legal subjectivity, and through external convergence represented by legal and administrative subjectivity. Both approaches are observed at the central level within specialized public authorities. Local state administration is characterized by the creation of internal administrative capacities with the challenging delimitation of which competences are affected by the process of administrative convergence.