Effect of the Predecessor and the Nitrogen Rate on Productivity and Essential Oil Content of Coriander (Coriandrum sativum L.) in Southeast Bulgaria

Received: May 31st, 2022 ; Accepted: August 13th, 2022 ; Published: September 19th, 2022 ; Correspondence: [email protected] (Coriandrum sativum L.) is one of the most important essential oil crops on a global scale. Coriander productivity is determined by the genotype, the environmental factors, as well the agronomic practices. A field experiment was conducted in Southeast Bulgaria during three vegetation seasons (2015, 2016, and 2017). The present study aimed at analysing the influence of two crop predecessors (winter wheat and sunflower) and four nitrogen (N) levels (0, 40, 80, and 120 kg ha-1 ). Productivity elements, seed yield, and seed essential oil content of coriander (cv. Mesten drebnoploden) were under evaluation. The results obtained showed that winter wheat was a more suitable predecessor of coriander in comparison to sunflower. The highest results regarding the number of umbels per plant, the umbel’s diameter, the number of umbellets per umbel, the number of seeds per umbel, the seed weight per plant, the 1,000 seed mass, as well as the seed yield for the rate of 80 kg ha-1 of N were recorded. The highest essential oil content after applying 120 kg ha-1 of N was established. Increasing the N level from 0 to 120 kg ha-1 led to a positive and significant effect on essential oil yield. No significant differences between the N rates of 80 and 120 kg ha-1 were recorded. The received results contributed for the evaluatation of the optimum nitrogen level, as well as for the determination of a more suitable predecessor of coriander in order to obtain the highest yield of better quality in the region of Southeast Bulgaria

The Antioxidant Role of Xanthurenic Acid in the Aedes aegypti Midgut during Digestion of a Blood Meal

In the midgut of the mosquito Aedes aegypti, a vector of dengue and yellow fever, an intense release of heme and iron takes place during the digestion of a blood meal. Here, we demonstrated via chromatography, light absorption and mass spectrometry that xanthurenic acid (XA), a product of the oxidative metabolism of tryptophan, is produced in the digestive apparatus after the ingestion of a blood meal and reaches milimolar levels after 24 h, the period of maximal digestive activity. XA formation does not occur in the White Eye (WE) strain, which lacks kynurenine hydroxylase and accumulates kynurenic acid. The formation of XA can be diminished by feeding the insect with 3,4-dimethoxy-N-[4-(3-nitrophenyl)thiazol-2-yl] benzenesulfonamide (Ro-61-8048), an inhibitor of XA biosynthesis. Moreover, XA inhibits the phospholipid oxidation induced by heme or iron. A major fraction of this antioxidant activity is due to the capacity of XA to bind both heme and iron, which occurs at a slightly alkaline pH (7.5-8.0), a condition found in the insect midgut. The midgut epithelial cells of the WE mosquito has a marked increase in occurrence of cell death, which is reversed to levels similar to the wild type mosquitoes by feeding the insects with blood supplemented with XA, confirming the protective role of this molecule. Collectively, these results suggest a new role for XA as a heme and iron chelator that provides protection as an antioxidant and may help these animals adapt to a blood feeding habit

Germ band retraction as a landmark in glucose metabolism during Aedes aegypti embryogenesis

<p>Abstract</p> <p>Background</p> <p>The mosquito <it>A. aegypti </it>is vector of dengue and other viruses. New methods of vector control are needed and can be achieved by a better understanding of the life cycle of this insect. Embryogenesis is a part of <it>A. aegypty </it>life cycle that is poorly understood. In insects in general and in mosquitoes in particular energetic metabolism is well studied during oogenesis, when the oocyte exhibits fast growth, accumulating carbohydrates, lipids and proteins that will meet the regulatory and metabolic needs of the developing embryo. On the other hand, events related with energetic metabolism during <it>A. aegypti </it>embryogenesis are unknown.</p> <p>Results</p> <p>Glucose metabolism was investigated throughout <it>Aedes aegypti </it>(Diptera) embryonic development. Both cellular blastoderm formation (CBf, 5 h after egg laying - HAE) and germ band retraction (GBr, 24 HAE) may be considered landmarks regarding glucose 6-phosphate (G6P) destination. We observed high levels of glucose 6-phosphate dehydrogenase (G6PDH) activity at the very beginning of embryogenesis, which nevertheless decreased up to 5 HAE. This activity is correlated with the need for nucleotide precursors generated by the pentose phosphate pathway (PPP), of which G6PDH is the key enzyme. We suggest the synchronism of egg metabolism with carbohydrate distribution based on the decreasing levels of phosphoenolpyruvate carboxykinase (PEPCK) activity and on the elevation observed in protein content up to 24 HAE. Concomitantly, increasing levels of hexokinase (HK) and pyruvate kinase (PK) activity were observed, and PEPCK reached a peak around 48 HAE. Glycogen synthase kinase (GSK3) activity was also monitored and shown to be inversely correlated with glycogen distribution during embryogenesis.</p> <p>Conclusions</p> <p>The results herein support the hypothesis that glucose metabolic fate changes according to developmental embryonic stages. Germ band retraction is a moment that was characterized as a landmark in glucose metabolism during <it>Aedes aegypti </it>embryogenesis. Furthermore, the results also suggest a role for GSK3 in glycogen balance/distribution during morphological modifications.</p

Prospects for biological control of teasels, Dipsacus spp., a new target in the United States

Two closely related teasels (Dipsacales: Dipsacaceae, Dipsacus spp.) of European origin have become invasive weeds in the United States. Common teasel (Dipsacus fullonum L.) and cutleaf teasel (Dipsacus laciniatus L.) have likely been in North America for more than two centuries, having been introduced along with cultivated teasel [D. sativus (L.) Honckney], an obsolete crop plant. There are few records of American insects or pathogens attacking Dipsacus spp. Invasive teasels have recently begun to spread rapidly throughout much of their current range, for reasons that are not yet known. Common and/or cut-leaf teasel have been listed as noxious in Wve US states and as invasive in 12 other states and four national parks. Because the family Dipsacaceae is an exclusively Old World family, classical biological control is an important component of the overall management strategy of this weed in the US. Field surveys for natural enemies of D. fullonum and D. laciniatus in their native ranges and literature reviews of natural enemies of plants in the family Dipsacaceae have yielded 102 species of insects in six orders, as well as 27 fungi from 10 orders, three mites, one nematode, and two viruses. Due to the biennial nature of these weeds, a strategy to assign highest priority to biological control candidates attacking Wrst-year (rosette) plants has been established. Candidates selected for further study based on this strategy include Chromatomyia ramosa (Hendel) (Diptera: Agromyzidae), Longitarsus strigicollis Wollaston (Coleoptera: Chrysomelidae), Epitrimerus knautiae Liro (Acarina: Eriophyiidae), Euphydryas desfontainii (Godart) (Lepidoptera: Nymphalidae), Erysiphe knautiae Duby (Erysiphales: Erysiphaceae), and Sphaerotheca dipsacearum (Tul. and C. Tul.) (Erysiphales: Erysiphaceae)

Conforming to the EU Food Quality and safety Standards in Bulgaria,

This book is an attempt to present shortly, but systematically, basic results, conclusions and recommendations from the joint research project „Conforming to EU standards and market requirements in the SME of Bulgaria: economic and social effects in the food industry”, headed by Prof. h. Jean-Pierre Gern of the University of Neuchatel, Switzerland. The project was financed by the Swiss National Foundation of Scientific Research in the frame of SCOPES 2005-2008 program. The basic research goal was to reveal social and economic effects of the obligatory implementation of the EU standards on quality, safety and environment protection on SME in the Bulgarian food industry and THE retail sector. The standards relate both to the quality and safety of products and workplaces, as well as to the environment protection. The results and conclusions could be of interest not only for specialized scientific community, but also for official bodies, responsible for conforming to the European food quality and safety standards, non-government organizations like different food sectors and retailers’ organizations, etc.Sofia University St. Kliment Ohridski, Faculty of Economics and Business Administration, Sofia, 112 p., ISBN 978-954-9399-08-0 (In English

Adaptation and Validation of a Burnout Inventory in a Survey of the Staff of a Correctional Institution in Bulgaria

Background: Burnout syndrome is a phenomenon that seems to be studied globally in relation to all types of populations. The staff in the system of correctional institutions in Bulgaria, however, is oddly left out of this tendency. There is no standardized model in Bulgaria that can be used to detect possible susceptibility to professional burnout. The methods available at present only register the irreversible changes that have already set in the functioning of the individual. V. Boyko’s method for burnout assessment allows clinicians to use individual approach to patients and affords easy comparability of results with data from other psychodiagnostic instruments. Adaptation of the assessment instruments to fit the specificities of a study population (linguistic, ethno-cultural, etc.) is obligatory so that the instrument could be correctly used and yield valid results. Validation is one of the most frequently used technique to achieve this

Икономически и социални ефекти от внедряването на европейските стандарти за качество и безопасност на храните в България

Настоящата книга представя основните резултати, изводи и препоръки от изследването по съвместен международен проект “Conforming to EU standards and market requirements in the SME of Bulgaria: economic and social effects in the food industry” с ръководител проф. Жан-Пиер Герн от Университета в Нюшател (Швейцария). Проектът е подпомогнат финансово от Националната фондация за научни изследвания на Швейцария. Основната цел на изследването е да се разкрият социално-икономическите ефекти от въвеждането на стандартите за качество и безопасност на храните в малките и средните предприятия от хранително-вкусовата промишленост, търговията с храни и общественото хранене в България. Разгледани са стандартите за качество и безопасност на продукта, условията на труд и опазването на околната среда. Получените резултати и изводи биха представлявали интерес както за специализираната научна общност, така и за редица държавни органи, отговорни за спазването на европейските стандарти за качество и безопасност на храните, а така също и за неправителствени организации, като браншови асоциации от секторите на хранителната индустрия, търговията с храни и др.Софийски университет „Св. Климент Охридски”, Стопански факултет, 367 с., А 4, София, ISBN 978-954-9399-09-

Внедряване на европейските стандарти за качество и безопасност на храните в България (икономически и социални ефекти).

СУ „Св. К. Охридски”, Стопански факултет, София, 128 с., А4, ISBN 978-954-9399-07-