Техники за запазване на поверителността и техни приложения в електронното обучение

The paper summarizes contemporary methods and techniques for privacy preservation as some challenging issues are analyzed and presented. A bibliometric approach is utilized in order for the "big picture" to be outlined, showing current research status and trending topics. The bibliographic data are taken from scientific database Scopus and processed through specialized software. In addition, a detailed review is also performed to classify problems and solutions in the area of privacy preservation. Special attention is given to possibilities for data privacy protection in intelligent eLearning environments. The role of machine learning for creating more secure data models is pointed out. A conceptual model, summarizing the findings, is proposed.This research is supported by the Bulgarian FNI fund through the project “Modeling and Research of Intelligent Educational Systems and Sensor Networks (ISOSeM)”, contract КП-06-Н47/4 from 26.11.2020

Određivanje strukture netopljivog dekstrana proizvedenog s pomoću bakterije Leuconostoc mesenteroides NRRL B-1149 u prisutnosti maltoze

Leuconostoc mesenteroides NRRL B-1149 is known to produce dextran with 52 % α-(1→6) and 40 % α-(1→3) linkages. Low solubility of dextran in water is associated with the presence of high percentage of α-(1→3) linkages. Leuconostoc mesenteroides NRRL B-1149 produces two types of enzymes, dextransucrase and fructansucrase, which are active with sucrose and raffinose, respectively, as confirmed by the activity staining. The insoluble dextran was synthesized using partially purified dextransucrase in the presence of maltose. A water-soluble dextran was also produced by dextransucrase from Leuconostoc mesenteroides NRRL B-1149. The produced insoluble dextran was purified by alcohol precipitation, and then structurally characterized using FTIR, 1H NMR, and 13C NMR spectroscopic techniques. From the spectral analysis, it was confirmed that the insoluble dextran produced by Leuconostoc mesenteroides NRRL B-1149 contained dextran with α-(1→6) linkages and α-(1→3) branched linkages. The surface morphology of dried and powdered dextran studied using scanning electron microscopy revealed its fibrous structure.Leuconostoc mesenteroides NRRL B-1149 proizvodi dekstran s 52 % α-(1→6) i 40 % α-(1→3) veza. Mala topljivost dekstrana u vodi u svezi je s velikim udjelom α-(1→3) veza. Leuconostoc mesenteroides NRRL B-1149 proizvodi dva tipa enzima, dekstran saharazu, koja se aktivira u prisutnosti saharoze, i fruktan saharazu, koja djeluje u prisutnosti rafinoze, što je potvrđeno bojenjem s Coomasie brilijant plavom bojom. Netopljivi je dekstran sintetiziran pomoću djelomično pročišćene dekstran saharaze u prisutnosti maltoze. Pomoću istog je enzima proizveden i dekstran topljiv u vodi. Netopljivi je dekstran pročišćen taloženjem alkoholom i zatim okarakteriziran FTIR, 1H NMR i 13C NMR spektroskopijom. Spektralnim je analizama potvrđeno da je netopljivi dekstran, proizveden s pomoću Leuconostoc mesenteroides NRRL B-1149, povezan α-(1→6) i α-(1→3) vezama. Pomoću skenirajućeg elektronskog mikroskopa (SEM) utvrđeno je da osušeni i mljeveni dekstran ima vlaknastu strukturu

Cytokines in Inflamed Mucosa of IBD Patients

Cells of the innate and the adaptive immune system have been identified as the key players in inflammatory bowel disease (IBD) pathogenesis, and the cytokines are central components of the inflammatory pathways that take place in the gut mucosa during the active and chronic phases of IBD. The effector cell response is largely determined by the type of cytokines that predominate in the intestinal mucosa. Here we describe the main cytokine players in intestinal inflammation during IBD—related to innate immune responses (tumor necrosis factor α—TNFα), TNF-like cytokine 1A, IL-8), and related to adaptive immune responses—Th1 (IL-1β, IL-18, IFNγ, IL-12), Th2 (IL-4, IL-5, IL-13, IL-11, IL-33), Th17 (IL-17A, IL-17F, IL-21, IL-22, IL-25, IL-27), cytokines required for Th17 development (IL-6, TGFβ, IL-23), anti-inflammatory cytokine IL-10 and Tregs along with IL-2. Recently described innate lymphoid cells (ILCs) could also be potential sources of IFN-γ, TNF, IL-5, IL-13, IL-17, and IL-22. The effects of cytokines in the gut are described in conjunction with the clinical implication and available biologic therapy. The data in the literature and our own results make us believe that in order to achieve immune homeostasis in the gut, pro-inflammatory and anti-inflammatory responses that define the mucosal cell immunophenotype should achieve balance

Microorganisms in Honey

Honey is a product with low water activity because of the great amount of sugars (fructose and glucose), and also it has antimicrobial compounds derived from flowers or because of its transformation process in the beehive. Despite all the honey microorganism barriers, some species of microorganisms are able to survive and may cause damage to honeybees or consumers. Techniques of pathogenic microorganism identification by DNA using PCR are recommended and required for sanitary and customs control. It is important to know the diversity of contaminating microorganisms in honey, especially due to disseminate pathogenic microorganisms in the international traded marketing. In contrast, beneficial microorganisms such as yeasts can remain latently in this product waiting for the moment in which the environment is suitable for their development. Among the beneficial bacteria found in honeybee products, we can mention some lactic acid bacteria that act as prebiotics when ingested. The microorganisms in the digestive tract of honeybees are important for their health. Thus, we present the knowledge of microbiota associated with honey from honeybees and stingless bees (Hymenoptera, Apidae) and the techniques available for the detection of microorganisms in honey

Lukanka, a Semi-Dried Fermented Traditional Bulgarian Sausage: Role of the Bacterial Cultures in its Technological, Safety and Beneficial Characteristics

Background: Production of different fermented meat products is a well-known practice done in different European countries since ancient times. Fermentation of primary materials and/or smoking and salting processes are part of the preservation processes and is important for the formation of final products which is inherent in South European countries. Originally, fermentation of meat products is intended for preservation and safe storage for long periods of time. However, nowadays, gastronomical properties of fermented meat products are essential in obtaining specific flavor, odor, color and structure of the sausages which consumers highly prefer. Emphasis is given on gastronomic characteristics, which results from the various combination of raw meat, specific spices and the natural microbiota or conducted fermentation processes by application of specific starter cultures. Seven bacterial genera (Lactobacillus, Leuconostoc, Staphylococcus, Enterococcus, Lactococcus, Micrococcus and Streptococcus) are commonly used as meat starter cultures. Complex fermentation processes that occur during the ripening of the fermented meat products are the results of the interaction between bacterial starter cultures, remaining enzymes in the muscle and fat tissue and available bacterial enzymes. Objective: The present overview aims to provide information related to the characterization of the specific microbiota associated with lukanka, a naturally-fermented semi-dried Bulgarian sausage. What is the specificity of its fermentation processes; how do different starter and indigenous meat microbiota interfere to form specific final products; what is the role of starter and adjunct cultures in the safety of the products; how is the Bulgarian lukanka classified in the perspective of other Mediterranean dry fermented sausages? These are some of the questions that this review will discuss

Bioelectromagnetics research within an Australian context: the Australian centre for electromagnetic bioeffects research (ACEBR)

Mobile phone subscriptions continue to increase across the world, with the electromagnetic fields (EMF) emitted by these devices, as well as by related technologies such as Wi-Fi and smart meters, now ubiquitous. This increase in use and consequent exposure to mobile communication (MC)-related EMF has led to concern about possible health effects that could arise from this exposure. Although much research has been conducted since the introduction of these technologies, uncertainty about the impact on health remains. The Australian Centre for Electromagnetic Bioeffects Research (ACEBR) is a National Health and Medical Research Council Centre of Research Excellence that is undertaking research addressing the most important aspects of the MC-EMF health debate, with a strong focus on mechanisms, neurodegenerative diseases, cancer, and exposure dosimetry. This research takes as its starting point the current scientific status quo, but also addresses the adequacy of the evidence for the status quo. Risk communication research complements the above, and aims to ensure that whatever is found, it is communicated effectively and appropriately. This paper provides a summary of this ACEBR research (both completed and ongoing), and discusses the rationale for conducting it in light of the prevailing science.Sarah P. Loughran ... Jim Manavis ... Robert Vink ... et al

Selección de un aislado del nucleopoliedrovirus de Helicoverpa armigera (HearNPV) para su uso como base de un bioinsecticida

Helicoverpa armigera (Lepidoptera; Noctuidae), conocida como el taladro del tomate, es una especie polífaga y de amplia distribución, responsable de grandes pérdidas económicas en más de 60 cultivos a lo largo de las regiones tropicales y subtropicales del mundo. Estas plagas se controlan mayoritariamente con plaguicidas químicos, aunque existe un gran interés por desarrollar otros agentes de control biológico. Entre estos, se encuentra el nucleopoliedrovirus de Helicoverpa armigera (HearNPV, Baculoviridae), que por sus características de seguridad y eficacia, sería útil para impulsar los programas de gestión integrada de plagas que se fomentan desde la Directiva 2009/128/CEE. El objetivo de este trabajo fue realizar una caracterización bioquímica y biológica de varios aislados de HearNPV : un aislado silvestre español (Badajoz) HearNPV-SP1, un aislado chino HearSNPV-G4, tres aislados sudafricanos (HearNPV-Whl, HearNPV-Kzn, HearNPV-Alb) y la materia activa de un producto comercial en uso en Europa (HearNPV-Hx). El análisis con las enzimas de restricción determinó que la enzima BglII generaba perfiles similares pero con fragmentos característicos en todos los casos a excepción de los aislados HearNPV-Kzn y HearNPVAlb, que no pudieron ser diferenciados entre sí con ninguna de las enzimas probadas. El análisis filogenético, basado en las secuencias parciales de los genes poliedrina (polh), lef-8 y lef-9, donde se incluyeron las secuencias correspondientes a 18 genomas mostró que el aislado HearNPV-Whl es filogenéticamente próximo a las cepas de origen ibérico, mientras que los aislados HearNPV-Hx y HearNPV-Alb comparten la misma rama que los aislados asiáticos y australiano. La caracterización insecticida de los aislados HearNPV-SP1, HearNPV-Hx y HearNPV-G4 reveló que la virulencia (TMM) del aislado HearNPV-SP1 (104 h) fue significativamente menor que la de los aislados HearNPV-G4 (109 h) y HearNPV-Hx (111 h). En este trabajo, se determinó que el tiempo de acción del HearNPV-SP1 es menor al de otros bioinsecticidas en uso en Europa, por lo que se confirma la posibilidad de mejorar los productos activos en uno de los aspectos más sensibles de cara a su comercialización como es su tiempo de actuación.Helicoverpa armigera (Lepidoptera, Noctuidae), known as the tomato borer is a key pest widely distributed and responsible for large economic losses in more than 60 crops throughout the tropical and subtropical regions of the world. Microbial insecticides are proposed as an alternative to control this pest, as they exhibit great advantages such as safety for non-target organisms including people exposed to them. Helicoverpa armigera nucleopolyhedrovirus (HearNPV; Baculoviridae) has been studied as a promising biological control agent to be implemented in the framework of integrated pest management, and recent EU legislation on the sustainable use of pesticides. This study addressed the biochemical and biological characterization of a collection of HearNPV isolates from different geographic origins including the Spanish wild isolate (Badajoz) HearNPV-SP1, the Chinese HearSNPV-G4 isolate, three South Africans isolates (HearNPV- Whl, HearNPV-Kzn, HearNPV-Alb) and the active ingredient of a biopesticides registered in Europe (HearNPV-Hx). The viral DNA analysis with restriction enzymes (REN) showed that BglII profiles distinguished the isolates each other by the presence of characteristic fragments, except to HearNPV-Kzn and HearNPV-Alb that could not be differentiate to one another using any of the tested enzymes. Secondly, a phylogenetic analysis was performed based on partial sequences of the three genes located in a highly conserved region (polyhedrin, late expression factor-8 and lef-9). To construct the phylogenetic tree 18 virus genomes were included, four of which were sequenced de novo and the rest obtained from the database Gene-Bank (NCBI). The HearNPV-Whl isolated was found phylogenetically close to the Iberian strains, while the isolates HearNPV-Hx and HearNPV-Alb shared the same branch together with Asian and Australian isolates. No common trend between closest geographically isolated was observed. The biological characterization was performed by bioassays for the three isolated HearNPV-SP1, HearNPV-Hx, and HearNPV-G4 in terms of mean time to death (MTD). The MTD value of HearNPV-SP1 (104hpi) Spanish isolate was significantly lower than those for the HearNPV-G4 (109hpi) and HearNPV-Hx (111hpi). The Spanish isolate exhibits very desirable characteristics as a biological control agent, being one of the most pathogenic and virulent HearNPV isolates described so far. Here we demonstrated that the HearNPVSP1 kill faster than the active ingredient of a biopesticide in use in Europe. The reforethis findings may contribute to improve HearNPV-based biopesticides by selecting those genotypes with the best speed of action, which mainly affect their efficiency in fields.Máster Universitario en AgrobiotecnologíaUnibertsitate Masterra Agrobioteknologia

Changes in Streptomyces hygroscopicus 155 endopeptidase and aminopeptidase activity and heat resistance under starvation and increased temperature

The influence of temperature stress and starvation for amino acids, glucose and phosphates, on the heat resistance of mycelium and endo- and aminopeptidase activity of Streptomyces hygroscopicus   155, was studied. The strongest growth inhibition was determined at temperature elevation from 30° to 39°C and at starvation for amino acids. Also these stress treatments mostly induce the heat resistance of the mycelium. A correlation between the intracellular endo- and aminopeptidase activity and decrease in biomass yield was registered. The process of catabolization of proteins, during the adaptation to stress treatments, depends on energy and is stimulated by the presence of Mg2+ ions