Παθογενετικοί μηχανισμοί της δυσλεξίας: μια ανασκόπηση

The authors of the present paper describe the probable pathogenetic mechanisms of specific reading disability, i.e. dyslexia. This analysis is grounded on the most widespread, yet hypothetical, cognitive deficit theories which account for the emergence and causation of dyslexia. These theories, coupled with the neurobiological underpinnings, imply that it is difficult to adopt a single approach in order to locate the causal relationships inherent to the disorder. Each one of the approaches provides critical insights to the mechanisms that underlie the development of literacy skills in normally developing children when exposed to literacy acquisition. Additionally, each theory attempts to explicate the factors that may be involved in the unexpected disruption of the learning process. The difficulty in establishing accurate phonological and orthographic representations in spite of adequate exposure to print, the transparency of mother tongue, brain architecture, and familial predisposition, all seem to contribute drastically to the deficient development of dyslexic children. Neuro-imaging studies along with molecular advances have been shedding even more light onto the backstage of dyslexic reading performance. Apparently, dyslexia could only be accounted for by an interactive approach within the framework of which the different influences from scientific trends may delineate the dyslexic phenotype.Η εργασία αυτή στόχο έχει να παρουσιάσει τους πιθανούς παθογενετικούς μηχανισμούς της ειδικής αναγνωστικής δυσκολίας, δηλαδή της δυσλεξίας. Η ανάλυση που επιχειρείται βασίζεται στις πιο διαδεδομένες, αν και υποθετικές, θεωρίες νοητικού ελλείμματος, που επεξηγούν την εμφάνιση και την αιτιότητα της δυσλεξίας. Το θεωρητικό υπόβαθρο που έχει αναπτυχθεί, σε συνδυασμό και με την ύπαρξη νευροβιολογικών θεωριών, υποδηλώνει ότι είναι δύσκολο να υιοθετηθεί μια και μόνη προσέγγιση προκειμένου να εντοπιστούν οι αιτιώδεις σχέσεις που είναι συμφυείς με αυτήν τη διαταραχή. Κάθε προσέγγιση εισφέρει κρίσιμες αντιλήψεις ως προς τους μηχανισμούς που βρίσκονται στη βάση της ανάπτυξης των αναγνωστικών δεξιοτήτων σε φυσιολογικώς αναπτυσσόμενα παιδιά, κατά την κατάκτηση της ανάγνωσης και της γραφής. Επιπλέον, κάθε θεωρία επιχειρεί να εξηγήσει τους παράγοντες που ενδεχομένως εμπλέκονται στην αναπάντεχη διατάραξη της μαθησιακής διαδικασίας. Η δυσκολία καθιέρωσης ορθών φωνολογικών και ορθογραφικών αναπαραστάσεων, παρά την ικανή έκθεση στον έντυπο λόγο, η διαφάνεια της μητρικής γλώσσας, η αρχιτεκτονική του εγκεφάλου και η οικογενειακή προδιάθεση, όλα δείχνουν ότι συμβάλλουν δραστικά στην ελλειμματική ανάπτυξη των δυσλεκτικών παιδιών. Oι νευροαπεικονιστικές μελέτες παράλληλα με την πρόοδο στη μοριακή βιολογία και γενετική φωτίζουν ακόμα περισσότερο τo παρασκήνιο της δυσλεκτικής αναγνωστικής επίδοσης. Προφανώς, μόνο μια διαδραστική προσέγγιση θα μπορούσε να εξηγήσει τη δυσλεξία, στο πλαίσιο της οποίας οι διαφορετικές επιρροές από τις επιστημονικές τάσεις ενδέχεται να διασαφηνίσουν το δυσλεκτικό φαινότυπο

Contribution of arbuscular mycorrhizal fungi to nitrogen and phosphorus uptake efficiency and productivity of faba bean crop on contrasting cropping systems

The present study was focused on evaluating the effect of AMF (Arbuscular Mycorrhizal Fungi) inoculation on nitrogen and phosphorus uptake efficiency and productivity of faba bean (Vicia faba L.) crop, under different fertilization levels on organic or conventional cropping systems. The 2-year field experiment was conducted in central Greece and laid out in a split-plot design, with three replications, two main plots (AMF inoculation treatments) and five sub-plots (fertilization treatments). The results demonstrated that plants of AMF inoculated plots exhibited greater plant height, leaf area index (LAI), leading to higher biomass, and consequently higher final seed yields. Regarding the quality parameters, including nutrients (nitrogen and phosphorus) uptake and their utilization indices, similar results to those of the productivity results were found with the AMF inoculated plants presented the higher values. Finally, all the parameters of the root system, including AMF root colonization and weighted mycorrhizal dependency (WMD), were negatively affected by fertilization level, particularly in an inorganic form. As a conclusion, the current study confirmed that replacement of inorganic inputs by organic in combination with AMF inoculation, should be seriously considered as a sustainable practice of faba bean crop cultivation under Mediterranean conditions

FL learning could contribute to the enhancement of cognitive functions in MCI older adults

The purpose of the current research endeavour was to evaluate if the learning of English as a Foreign Language (EFL) could constitute an effective non-pharmacological intervention for older adults diagnosed with Mild Cognitive Impairment (MCI). Specifically, the focus was on the assessment of the impact of EFL learning on a variety of cognitive and psychological functions. To this aim, a total sample of 241 Greek older adults was recruited from the day care units for patients with dementia of the Greek Association of Alzheimer’s Disease and Related Disorders, in Thessaloniki, Greece. An experimental research design was adopted and two groups were formulated. The intervention group comprised 98 individuals who attended an18-month EFL course and either had no prior knowledge of English or had attended some lessons decades before. The control group included 143 individuals who did not attend any cognitive stimulation programme within the premises of the day care units. A battery of neuropsychological tests, assessing general cognitive functioning, attention, verbal learning, memory, visuo-perceptual ability, executive function, and depression, was administered by the psychologists of the day care units to all of the participants. Neuropsychological data for the intervention group were collected at three time-points (i.e. pre-, mid-, and post-intervention), while neuropsychological data for the control group were collected at two time-points (i.e. pre- and post-research). Hypothesis testing revealed statistically significant differences both within the intervention group and between the intervention and control group across the evaluation time-points

Effect of Lentil Cover Cropping on Soil Hydraulic Properties and Subsequent Crop Productivity in Two Soil Types in Central Greece

Agricultural management practices can significantly affect soil hydraulic properties and processes in space and time. Cover crops are described as “crops grown primarily for the purpose of protecting and improving soil between periods of regular crop production”. They have long been valued for their soil conservation benefits, including reducing erosion, increasing infiltration, and improving soil health. Experiments were carried out on a clayey and on a sandy soil, following a RCB design, for two years, to examine the effects of various lentil cover cropping managements on soil hydraulic properties and subsequent corn yield. Three legume managements were tested before growing corn (rotation, incorporation as green manure, no cover crop). Soil hydraulic properties were assessed with the equation I= S*t -1/2+ Ktr*t + d. Corm productivity was determined by field samplings. Green manuring and rotation with lentil, lowered the Infiltration rate as well as the Hydraulic conductivity in the sandy soil, suggesting less irrigation water losses and higher water exploitation for the subsequent crop. On the contrary, for the clay soil, only Hydraulic conductivity of transiting zone was affected and especially during springtime. Legume rotation and green manure positively affected corn kernel yield in both soils

Lentil Crop Rotation and Green Manuring Effects on Soil Structural Stability and Corn Yield in Different Soils in Central Greece

Grain legume production contributes widely to ecosystem services and have the potential to improve soil structure, increase soil organic carbon and reduce soil compaction. Growing more legumes in future requires changes to the cropping system, the sequence, and crop management. The objectives of this study were to examine the effects of lentil cover cropping managements on (i) soil structure and (ii) subsequent corn yield, in two different soil types. Experiments were carried out on a clayey and on a sandy soil, following a RCB design, for two years. Three legume managements were tested before growing corn (rotation, incorporation as green manure, no cover crop). For assessing soil structure stability the instability index, β was used. Corm productivity was determined by field samplings. Both lentil management, had significant effect on the instability index β. Stability of soil aggregates was enhanced during spring and reduced during autumn, regardless of the lentil pre-treatment, confirming the seasonal variation of soil structure stability. Legume rotation and green manure positively affected corn kernel yield in both soils. Results suggest that lentil rotation or green manuring has a positive effect on soil structure on both sandy and clay soils, leading to higher yields for subsequent corn crop

Designing Innovative Crops According to the Needs of Climate Change and Green Deal

Climate change and environmental degradation pose an actual threat to Europe and the rest of the world. Innovative or retrovative crops could be components of alternative redesigned agro-ecosystems, meeting the EU Green Deal targets for reduced use of chemical inputs by 2030. The present study aimed to evaluate: a) the adaptation of production to the stormy effects of climate change, b) the detection of the receptivity of the producers to the application of the design of innovative and retro-innovative crops in the field, and c) the in-depth detection of inhibiting factors (natural resources, economic, social and anthropogenic factors) for producers. A quantitative research was performed using structured interviews (face to face - a set of questions) and open-ended questions. The selected sample was composed of 41 farmers and the study area was the Mani Peninsula, Southern Greece. The statistical processing of the answers showed a significant correlation of change receptivity with age, educational level and the main profession. Younger people, those with higher education and non-mainstream farmers are more receptive to change and switch to innovative crops. The environment, climatic and economic, requires adaptation and change in order to maintain sustainability. Producers are receptive to reforms and shifts to innovative and retro-innovative crops. However, there is a lack of coherent policies in the direction of building infrastructure, solving structural problems, training and transferring know-how, and finally, providing incentives and opportunities by creating and utilizing the appropriate tools

Performance of fourteen genotypes of durum wheat under Eastern Mediterranean conditions

Durum wheat is used as raw material for many foods. Climate change might be responsible for larger or smaller changes in crop yields. For the combined assessment of climate and crop, growing degree days (GDDs) have a crucial role. Two experimental lines and twelve commercial wheat (Triticum durum) varieties from diverse backgrounds were cultivated to compare their crop properties, yield, and protein content in terms of GDDs. The experiment was established in typical Mediterranean environment, using a randomized complete block design with blocks of varieties and lines for two growing seasons. For all varieties, GDDs to head emergence was affected by factor year, whereas GDDs from head emergence to harvest were influenced by both varieties and year. Protein content (%) was not affected by genotypes. Factor of variety and interaction variety × year had an impact on vitreousness; it was ranged from 79.75 % (‘Makaras’ variety) to 44.00 % (‘Levante’ variety). Yield had no statistically significant difference among varieties/lines. In durum wheat cultivation, up to head emergence, when GDDs increased, yield would be declined in contrast to GDDs from emergence to harvest; with the increasing of GDDs to harvest, yield was climbed. Nowadays, the integrations of and interpretation of GDDs in the evaluation of crop performance seem vital

Performance of two cotton interspecific hybrids (Gossypium hirsutum L. × G. barbadense L.) in Greece: A comparative case study

Cotton (Gossypium hirsutum L.) is one of the most prominent and important industrial crops. In Greece, cotton farming occupies a significant share of the agricultural sector. However, the adverse effects of climate change have raised concerns regarding its performance in the near future, thus it is crucial to develop adaptation strategies for the production of cotton in Greece. One such alternative is the adoption of interspecific hybrids (G. hirsutum × G. barbadense). These hybrids have been suggested to be more resilient and to outperform their parental varieties. In order to evaluate the potential of such hybrids, a field experiment was conducted in two sites in Greece. Two novel cotton hybrids (1432 and 701) and a conventional variety (‘Elpida’) were farmed in two different plant densities (8 and 13 plants m2) and their agronomic traits (biomass, LAI), yield and yield components (seed cotton yield, lint yield, seed yield, ration lint/seed cotton, and ratio seed/seed cotton), and quality traits were assessed. The agronomic traits and the yield of the hybrids were equal or superior in comparison to ‘Elpida’. Similar findings were also observed in the majority of the quality traits. Based on our results, interspecific cotton hybrids are promising for the European cotton sector.