Practical Approaches to Pest Control: The Use of Natural Compounds

Food production is challenged by different factors: climate changes, market competitiveness, food safety, public demands, environmental challenges, new and invasive pests, etc. Intensive food production must be protected against pests, which is nowadays impossible with traditional techniques. The use of eco-friendly biopesticides based on essential oils (EOs), plant extracts (PE), and inert dusts appears to be a complementary or alternative methodology to the conventional chemically synthesized insecticides. The use of such biopesticides reduces the adverse pesticide effects on human health and environment. Biopesticides can exhibit toxic, repellent, and antifeeding effects. Development of bio-insecticides tackles the problem of food safety and residues in fresh food. Innovation within this approach is the combination of several types of active ingredients with complementary effects. Essential oils are well-known compounds with insecticide or repellent activities. New approaches, tools, and products for ecological pest management may substantially decrease pesticide use, especially in fruit and vegetable production. A win-win strategy is to find an appropriate nature-based compound having impact on pests, together with pesticide use, when unavoidable. Toxic or repellent activity could be used for pest control in the field conditions, as well as attractiveness of some compounds for mass trapping, before pests cause significant economic damage

Zajednica Arctio-Artemisetum vulgaris (Tx. 1942) Oberd. et al. 1967.: najzastupljenija ruderalna zajednica na području Pančevačkog rita

A several-year investigation of distribution, phytocoenological differentiation, floristic composition and structure of the ruderal flora and vegetation, and relative anthropogenic influences was conducted in the area of Pančevački rit. The study focused on the ruderal community Arctio-Artemisetum vulgaris, the most widespread of 10 ruderal communities identified in a detailed phytocoenological analysis of the location of Pančevački rit.Na području Pančevačkog rita su obavljena višegodišnja floristička istraživanja rasprostranjenosti, fitocenološke diferenciranosti, strukturalne i antropogene uslovljenosti ruderalne vegetacije. U radu je analizirana zajednica Arctio-Artemisetum vulgaris, koja predstavlja najrasprostranjeniju zajednicu od 10 razvijenih i opisanih ruderalnih zajednica na prostoru Pančevačkog rita

Tourbillion in the phase space of the Bray-Liebhafsky nonlinear oscillatory reaction and related multiple-time-scale model

The mixed-mode dynamical states found experimentally in the concentration phase space of the iodate catalyzed hydrogen peroxide decomposition (The Bray-Liebhafsky oscillatory reaction) are discussed theoretically in a related multiple-time-scale model, from the viewpoint of tourbillion. With aim to explain the mixed-mode oscillations obtained by numerical simulations of the various dynamical states of a model for the Bray-Liebhafsky reaction under CSTR conditions, the folded singularity points on the critical manifold of the full system and Andronov-Hopf bifurcation of the fast subsystem are calculated. The interaction between those singularities causes occurrence of tourbillion structure

Reduced order modeling of harmonic signals

Dans cet article on traîte le problème d'estimation des fréquences des' sinusoïdes' dans le cas où la structure du modèle n'est pas connue a priori. Deux algorithmes sont proposés pour l'estimation simultanée de la fréquence et de l'ordre du modèle. Le premier, applicable "off-line", est basé sur la métode des moindres carrés genéralisée tendis que le second est recursif, basé sur la méthode RML. Dans les deux cas on suppose que le modèle est dans ta forme des "notch" filtres en cascades. L'estimation de l'ordre est basé sur les tests directs de la puissance des signaux résudus. Les résultats de l'analyse expérimentale donnent une illustration des qualités des méthodes proposées, qui représentent un outil simple, mais efficace, pour les applications pratiques

Prosodic Abilities and Phonological Working Memory in Swedish Preschool Children with Cochlear Implants

Cochleaimplantat (CI) är ett hörselhjälpmedel som kan ge barn med grav hörselnedsättning eller dövhet möjlighet att höra och utveckla talat språk. Svenska grundskolebarn med CI har tidigare visats ha en något nedsatt prosodisk förmåga och fonologiskt arbetsminne även om stora individuella variationer förekommer. Syftet med föreliggande studie var att undersöka prosodisk förmåga och fonologiskt arbetsminne hos svenska förskolebarn med CI. Vidare undersöktes samband mellan prosodisk förmåga och fonologiskt arbetsminne. I studien deltog sex förskolebarn med CI och totalt 18 normalhörande kontroller, varav sex var ålders-, köns- och dialektmatchade med barnen med CI. Barnen med CI i föreliggande studie uppvisade som grupp signifikant lägre resultat än de normalhörande barnen på test avseende prosodisk produktion på ord-, fras- och diskursnivå samt på test som undersöker fonologiskt arbetsminne. Gällande receptiv prosodisk förmåga förekom inga signifikanta skillnader. Vid jämförelse med svenska grundskolebarn med CI framkom att både yngre och äldre barn med CI har svårigheter med prosodi på samtliga nivåer. Vidare jämförelser indikerar att en utveckling av receptiv prosodisk förmåga sker under förskole- och skolåren. Korrelationsberäkningarna tyder på att det föreligger ett samband mellan prosodisk förmåga och fonologiskt arbetsminne. Barnen med CI i föreliggande studie är en heterogen grupp och några barn uppvisade på vissa deltest likvärdiga resultat som sina matchade kontroller, vilket visar att CI ger goda förutsättningar att utveckla prosodiska förmågor och talad kommunikation.Cochlear Implant (CI) is a hearing device that can enable deaf children or children with severe hearing impairment to hear and to develop spoken language. Research has shown that Swedish school aged children with CI have poor prosodic abilities to some extent, as well as poor phonological working memory. However, there are large individual differences. The aim of the present study was to investigate prosodic abilities and phonological working memory in Swedish preschool children with CI. Moreover, the relation between prosodic abilities and phonological working memory was examined. Six preschool children with CI participated in the study. The control group consisted of 18 children with normal hearing, out of which six children were matched for age, sex and regional dialect to the children with CI. In the present study the children with CI as a group demonstrated significantly lower results compared to the children with normal hearing on tests concerning prosodic production abilities at word, phrase and discourse level and tests concerning phonological working memory. No significant differences emerged regarding receptive prosodic abilities. In comparison to Swedish school aged children with CI it was shown that both younger and older children with CI have difficulties at all prosodic levels. Furthermore, the comparisons indicate that receptive prosodic skills develop during preschool and school years. Results also indicate a connection between prosodic abilities and phonological working memory. The children with CI in the present study is a heterogeneous group and a few children demonstrated equivalent results as their matched controls on some parts of the tests, which show that CI provides a good foundation for developing prosodic abilities and spoken communication

Characterisation of twelve newly synthesised N-(substituted phenyl)-2-chloroacetamides with QSAR analysis and antimicrobial activity tests

In this study we screened twelve newly synthesised N-(substituted phenyl)-2-chloroacetamides for antimicrobial potential relying on quantitative structure-activity relationship (QSAR) analysis based on the available cheminformatics prediction models (Molinspiration, SwissADME, PreADMET, and PkcSM) and verified it through standard antimicrobial testing against Escherichia coli, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and Candida albicans. Our compounds met all the screening criteria of Lipinski's rule of five (Ro5) as well as Veber's and Egan's methods for predicting biological activity. In antimicrobial activity tests, all chloroacetamides were effective against Gram-positive S. aureus and MRSA, less effective against the Gram-negative E. coli, and moderately effective against the yeast C. albicans. Our study confirmed that the biological activity of chloroacetamides varied with the position of substituents bound to the phenyl ring, which explains why some molecules were more effective against Gram-negative than Gram-positive bacteria or C. albicans. Bearing the halogenated p-substituted phenyl ring, N-(4-chlorophenyl), N-(4-fluorophenyl), and N-(3-bromophenyl) chloroacetamides were among the most active thanks to high lipophilicity, which allows them to pass rapidly through the phospholipid bilayer of the cell membrane. They are the most promising compounds for further investigation, particularly against Gram-positive bacteria and pathogenic yeasts