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The aim of the present dissertation is a taxonomic study of the representatives of 3 selected fern families, their distribution and ecological characteristics in Bulgaria. The main tasks are related to field work and collection of materials, taxonomic revision of the collections in all Bulgarian and some foreign herbaria, research on morphology, chorology, vertical distribution, ecology, chromosome number, ploidy levels, evolutionary mechanisms, compiling of determination keys for the genera and species in the Bulgarian flora. The taxonomic diversity of 5 genera with a total of 16 species and 3 hybrids was studied. One species (Polystichum braunii) and two hybrids (P. × bicknellii and Dryopteris × ambroseae) are new to the Bulgarian flora. Updated determination keys for genera and species were presented. Detailed morphological descriptions were prepared. Ecological requirements were clarified. An analysis of the horizontal and vertical distribution of taxa was made. New floristic distribution areas for 17 taxa were identified. For the first time in Bulgaria, chromosome numbers and ploidy levels of 15 taxa were established. Six of them are diploids, 4 - triploids (3 hybrids and 1 apomictic species), 6 - tetraploids and 1 - hexaploid. For the first time in Bulgaria, light microscopic study of mature spores of 19 taxa as well as additional SEM study of spores of 2 taxa were performed,. Assessments were made according to the IUCN Criteria for 2 species., Целта на настоящата дисертация е таксономично проучване на представителите на 3 избрани семейства папрати, разпространението и екологичните им характеристики в България. Основните задачи са свързани с теренна работа и събиране на материали, таксономична ревизия на колекциите в българските и някои чужди хербариуми, изследвания върху морфологията, хорологията, вертикалното разпределение, екологията, хромозомния брой, нивата на плоидност, очертаване на основните еволюционни механизми в родовете, съставяне на определителни ключове за родовете и видовете в българската флора. Проучено е таксономичното разнообразие на 5 рода с общо 16 вида и 3 хибрида. Един вид (Polystichum braunii) и два хибрида (P. ×bicknellii и Dryopteris ×ambroseae) са нови за българската флора. Представени са актуализирани определителни ключове за родовете и видовете. Изготвени са подробни морфологични описания. Изяснени са екологичните изисквания. Направен е анализ на хоризонталното и вертикалното разпределение на таксоните. Идентифицирани са нови флористични райони на разпространение за 17 таксона. За първи път в България са установени хромозомните числа и нивата на плоидност на 15 таксона. Шест от тях са диплоиди, 4 – триплоиди (3 хибриди и 1 апомиктен вид), 6 – тетраплоиди и 1 – хексаплоиден. За първи път в България е извършено светлинно микроскопско изследване на зрели спори от 19 таксона, както и допълнително SEM изследване на спорите на 2 таксона. Направени са оценки по Критериите на IUCN за 2 вида.

Analogue film restoration, both for still photographs and motion picture emulsions, is a slow and laborious manual process. Artifacts such as dust and scratches are random in shape, size, and location; additionally, the overall degree of damage varies between different frames. We address this less popular case of image restoration by training a U-Net model with a modified perceptual loss function. Along with the novel perceptual loss function used for training, we propose a more rigorous quantitative model evaluation approach which measures the overall degree of improvement in perceptual quality over our test set.

Despite the central role of amyloid beta (A beta) peptide in the etiopathogenesis of Alzheimer's disease (AD), its physiological function in healthy brain is still debated. It is well established that elevated levels of A beta induce synaptic depression and dismantling, connected with neurotoxicity and neuronal loss. Growing evidence suggests a positive regulatory effect of A beta on synaptic function and cognition; however the exact cellular and molecular correlates are still unclear. In this work, we tested the effect of physiological concentrations of A beta species of endogenous origin on neurotransmitter release in rat cortical and hippocampal neurons grown in dissociated cultures. Modulation of production and degradation of the endogenous A beta species as well as applications of the synthetic rodent A beta(40) and A beta(42) affected efficacy of neurotransmitter release from individual presynapses. Low picomolar A beta(40) and A beta(42) increased, while A beta depletion or application of low micromolar concentration decreased synaptic vesicle recycling, showing a hormetic effect of A beta on neurotransmitter release. These A beta-mediated modulations required functional alpha7 acetylcholine receptors as well as extracellular and intracellular calcium, involved regulation of CDK5 and calcineurin signaling and increased recycling of synaptic vesicles. These data indicate that A beta regulates neurotransmitter release from presynapse and suggest that failure of the normal physiological function of A beta in the fine-tuning of SV cycling could disrupt synaptic function and homeostasis, which would, eventually, lead to cognitive decline and neurodegeneration.

Release of neurotransmitter is executed by complex multiprotein machinery, which is assembled around the presynaptic cytomatrix at the active zone. One well-established function of this proteinaceous scaffold is the spatial organization of synaptic vesicle cluster, the protein complexes that execute membrane fusion and compensatory endocytosis, and the transmembrane molecules important for alignment of pre- and postsynaptic structures. The presynaptic cytomatrix proteins function also in processes other than the formation of a static frame for assembly of the release apparatus and synaptic vesicle cycling. They actively contribute to the regulation of multiple steps in this process and are themselves an important subject of regulation during neuronal plasticity. We are only beginning to understand the mechanisms and signalling pathways controlling these regulations. They are mainly dependent on posttranslational modifications, including phosphorylation and small-molecules conjugation, such as ubiquitination. Ubiquitination of presynaptic proteins might lead to their degradation by proteasomes, but evidence is growing that this modification also affects their function independently of their degradation. Signalling from presynapse to nucleus, which works on a much slower time scale and more globally, emerged as an important mechanism for persistent usage-dependent and homeostatic neuronal plasticity. Recently, two new functions for the largest presynaptic scaffolding proteins bassoon and piccolo emerged. They were implied (1) in the regulation of specific protein ubiquitination and proteasome-mediated proteolysis that potentially contributes to short-term plasticity at the presynapse and (2) in the coupling of activity-induced molecular rearrangements at the presynapse with reprogramming of expression of neuronal activity-regulated genes.

The food industry has been seen as one of the most successful sectors in Bulgaria with potential to growth. At the same time agriculture and food industry have had large negative effect on the environment. For reduction of the potential harmful environmental impact caused by agricultural and food sector it is time to transform into a sustainable production. Certification schemes are one of the most common policy instruments used for promoting sustainable production and consumption. A total 90 producers in food sector were asked about motivation for certification, the challenges and outcomes of certification. The survey provides information on existing certification schemes (system certification and products certification) among companies in the food sector in Bulgaria.

The paper discusses the possibilities for establishing a system for independent comparative tests of products on a national level with the participation of stakeholders in the provision of consumer information. The method of “in-depth interview” was used for the purposes of the survey. Interviews were conducted with 23 people - representatives of stakeholders from a system of independent comparative product tests: experts from the central government, representatives of the business and the sectoral organisations, non-governmental organisations, consumers’ associations, representatives of the media and the specialized editions, consulting and certifying companies and educational organisations (universities), scientific research institutions and others. The participants’ views for generating and providing of independent information through consumers’ comparative testing of products in Bulgaria are analyzed and summarized. On the basis of the expressed statements (content analysis) conclusions are drawn for the purpose, scope, prerequisites for establishing a system for independent comparative product tests on a national level as well as opportunities for European and international cooperation in this field.

An identification and analysis of practices for providing consumer information in Bulgaria and their potential to disclose information about products to consumers are presented. Third party certification, labelling and comparative testing of products has been proven to effectively contribute for development of an efficient market by diminishing asymmetry of information. Discussion focuses on the alternative practices for submitting information and consideration of their accessibility and independence. The disclosure of information to consumers by the websites for comparison of products prices, collective shopping and consumer assistance is explored. Conclusions are drawn regarding their potential role in future shifts towards efficient consumer information practices in Bulgaria.