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Digital library of scientific journals published by Plovdiv University Paisii Hilendarski.

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1922 – 1925 in BULGARIA – LITERATURE, LITERARY CRITICISM and POLITICS
(Plovdiv University Press “Paisii Hilendarski”, 2024-04-21) Protohristova, Kleo
This text aims at analysing literary life in Bulgaria between 1922 and 1925. The analysis is motivated by the dominant impression of its extraordinary intensity and draws upon the assumption that the chronological stretch is self-contained as a distinct micro-period in national literary history. The goal of this research is to endorse the hypothesis that the projection potential in the dynamics of the examined time span is meaningful. Observations have been carried out in the mode of H. R. Jauss’s “synchronic cross-sections” and include contextualising parallels with the respective literary years in Western European literature.
3D structure prediction of lignolytic enzymes lignin peroxidase and manganese peroxidase based on homology modelling
(Plovdiv University Press “Paisii Hilendarski”, 2015-11-27) Kale, Swapnil K.; Deshmukh, Amit G.
Lignolytic enzymes have great biotechnological value in biopulping, biobleaching, and bioremediation. Manganese peroxidase (EC 1:11:1:13) and lignin peroxidase (EC 1:11:1:14) are extracellular and hem-containing peroxidases that catalyze H2O2-dependent oxidation of lignin. Because of their ability to catalyse oxidation of a wide range of organic compounds and even some inorganic compounds, they got tremendous industrial importance. In this study, 3D structure of lignin and manganese peroxidase has been predicted on the basis of homology modeling using Swiss PDB workspace. The physicochemical properties like molecular weight, isoelectric point, Grand average of hydropathy, instability and aliphatic index of the target enzymes were performed using Protparam. The predicted secondary structure of MnP has 18 helices and 6 strands, while LiP has 20 helices and 4 strands. Generated 3D structure was visualized in Pymol. The generated model for MnP and LiP has Z-score Qmean of 0.01 and -0.71, respectively. The predicted models were validated through Ramachandran Plot, which indicated that 96.1 and 95.5% of the residues are in most favored regions for MnP and LiP respectively. The quality of predicted models were assessed and confirmed by VERIFY 3D, PROCHECK and ERRAT. The modeled structure of MnP and LiP were submitted to the Protein Model Database.
45 YEARS IS NOT ENOUGH: AN IDEA THAT SHOOK THE WORLD OF LINGUISTICS
(Plovdiv University Press "Paisii Hilendarski", 2024) Dagnev, Ivaylo
Conceptual metaphor theory emerged in the late 1970s and early 1980s and viewed the process and product of metaphorization as a complex interrelationship between language and thought. A central claim of this theory proposed by Lakoff & Johnson and subsequently developed by numerous researchers is that the apperception of the unknown takes place through a special process of construction in semantics – metaphorization, which results from the complex interaction between embodied experience, the conceptual system and its linguistic representation. The evolution of the theory problematises many essential issues of semantics such as the meaning and use of words, the relationship between literal and figurative meaning, between the conceptual character and the lexical expression in language. Like any significant idea, the theory of conceptual metaphor has become the target of numerous criticisms on all its aspects, which, after all, are the necessary driving force for its development.
A case of transportation of Cimex hemipterus (Fabricius, 1803) (Insecta, Hemiptera) in Bulgaria
(Plovdiv University Press "Paisii Hilendarski", 2024-03-25) Georgiev, Dilian
During the period of 02-09.03.2024, the author and their family stayed in a hotel infested with bed bugs in Uroa village, Unguja Island, Zanzibar. Upon returning to Bulgaria (Hrishteni village, Stara Zagota city area), one specimen of Cimex hemipterus (Fabricius, 1803) was found alive in the luggage. This should be the first documented record of the tropical bed bug in Bulgaria, and the possibility of transfer via increased touristic visit in tropical destinations were briefly discussed.
A contribution to the knowledge of the trophic spectrum of three lacertid lizards from Bulgaria
(Plovdiv University Press “Paisii Hilendarski”, 2013-04-04) Mollov, Ivelin; Petrova, Slaveya
A study on the trophic spectrum of three species of lacertid lizards (Lacerta agilis, Lacerta trilineata and Podarcis muralis) was carried out, based on 20 specimens collected in the period 1967-1973 in various localities in Bulgaria. The analyzed data showed that the insects (Insecta) are the most numerous and the most frequently met among the alimentary components of the total amount of food of the studied stomachs (except for Lacerta agilis, where spiders are slightly predominating). The non-insect components consisted spiders and isopods. The largest niche breadth was recorded in Lacerta trilineata (8.25), followed by Podarcis muralis (5.20) and Lacerta agilis (3.44). The niche overlap between the three species (pair-wise comparison) showed medium values and in our opinion there should not be any serious competition for food resources at the places with sympatric distribution.
A new collection of Psocodea (Insecta) from Unguja Island (Zanzibar, Tanzania)
(Plovdiv University Press "Paisii Hilendarski", 2024-03-30) Georgiev, Dilian
The study presents a new collection of Psocodea (Insecta) from Unguja Island (Zanzibar, Tanzania), conducted during March 3rd to 9th, 2024. Despite recent efforts to explore Psocodea fauna in equatorial and tropical Africa, comprehensive studies in East Africa, particularly along the east coast and inland areas, remain limited. This research contributes to filling these gaps by documenting 16 species, including nine new records for the Zanzibar autonomic region and seven new records for Tanzania. Notably, one species (Nanopsocus sp.) may potentially be new to science.
A novel neutral protease from thermophilic Bacillus strain HUTBS62
(Plovdiv University Press “Paisii Hilendarski”, 2012-10-15) Aqel, Hazem; Al-Quadan, Farouk; Yousef, Tahani K.
A novel neutral highly thermostable protease was detected in the culture medium of thermophilic Bacillus strain HUTBS62 isolated from hot-spring located near to the Dead Sea, Jordan. The enzyme was purified by precipitation with 55-60% ammonium sulfate, gel filtration on Sephadex G-100 and DEAE ion exchange chromatography. The enzyme was purified 53-fold with 2% yield. The optimum pH and temperature for catalytic activity of protease was pH 6.8 and 80ºC, respectively, and 31% activity of protease remained even after heat treatment at 100ºC for 60 min. The relative activity of the enzyme was highly stable (90%) at 50ºC for 2 h. The half-life of the enzyme at 90ºC, 80ºC and 70ºC was estimated to be 3, 4 and 6 h, respectively. The activation energy of denaturation of purified enzyme was 21.7 kJmol-1. Iron, sodium, calcium, and manganese increased protease activity. On the other hand, magnesium, cobalt and zinc variably decreased the residual activity. But cadmium and copper drastically inhibited the enzyme activity. The enzymatic activity was highly stable in the presence of 1 and 2 mM EDTA at pH 6.8 and 80ºC. The neutral protease therefore could be defined as a highly thermostable with new properties make the present enzyme applicable for many biotechnological purposes.
A novel polymerase chain reaction (PCR) based assay for authentication of cell lines or tissues from human, pig and chicken origin
(Plovdiv University Press "Paisii Hilendarski", 2012-05-11) Gorenjak, Mario; Trapecar, Martin; Gradisnik, Lidija; Skok, Pavel; Cencic, Avrelija
A polymerase chain reaction based assay was developed for authentication of cell lines or tissues from human, pig and chicken origin. Specificity was achieved by species specific primer design targeting the mitochondrial D-loop sequence. Amplicon sizes were 114 bp, 169 bp and 645-648 bp for chicken, human and pig derived cell lines, respectively. Primers were tested for species specificity and non-specificity between haplogroups of the same organisms using BLAST tool and subsequently for cross amplification DNA extracted from human, chicken and pig venous blood as a positive control. Primers were also amplifying specific products in DNA extracted from individual cell line in both functional cell models and intentionally mixed cell lines consisting functional cell models. The PCR assay developed in this study represents a low-cost species specific end-point PCR based assay of the mitochondrial D-loop for the authentication of the cell line origin.
A potential Bio corridor for bears? New data on the occurrence of Ursus arctos (Linnaeus, 1758) in the Eastern Balkan Mountains
(Plovdiv University Press "Paisii Hilendarski", 2024-07-01) Marinova, Pavlina; Kolev, Nikolay; Natchev, Nikolay
In the present study we provide data on the presence of a Brown bear specimen in the Eastern Stara Planina (Eastern Balkan). We obtained camera-trap images and photographs of the footprints of bears from the region of Varbishki and Rishki passes (Varbishki Prohod and Rishki Prohod). The locations were positioned at over 100 km from the easternmost border of the core population of bears in the central Stara Planina. Our data indicate a potential bio corridor allowing at least for young bears to migrate east along the mountain.
A preliminary study of the effect of phytoadditive carvacrol on the trace elements (Cu, Mn and Zn) content in fish tissues
(Plovdiv University Press “Paisii Hilendarski”, 2014-01-08) Yılmaz, Ebru; Yılmaz, Sevdan; Ergün, Sebahattin; Kaya, Hasan; Kızılkaya, Bayram; Soytaş, Nergiz
Phytoadditives have gained increasing interest as feed additives for fish. The aim of the present study was to determine whether selected dietary phytoadditive can influence the bioavailability of several trace elements (Cu, Mn and Zn), which play an important role in the physiological processes. The experiments were carried out at a commercial trout farm. A total of 420 juvenile rainbow trout (mean weight ± SD = 10.79±0.57), Oncorhynchus mykiss, were randomly allocated into four different treatments with three replicates each. Fish were kept in raceways (3X0.8X0.4 m) at 10±1°C with a natural photoperiod. Proper amount of carvacrol was sprayed on 1 kg of commercial trout diet to prepare four diets with 0 (Control, C0), 1 (C1), 3 (C3) and 5 (C5) carvacrol g/kg diet. Fish were fed to apparent satiation three times per day. The feeding trial lasted four weeks. Then, in different type of fish tissues (muscle, liver and pyloric caeca) from fish fed with diets enriched in carvacrol, beneficial elements (Cu, Mn and Zn) were analysed by atomic adsorption spectrophotometer. Results showed that the levels of Cu, Zn and Mn were especially significantly increase by C1 diet in all tissues (muscle, liver and pyloric caeca) except muscle and pyloric caeca Zn. The results of this experiment indicate that the carvacrol had the ability to potentiate the trace element retention. Although bioaccumulations of Cu, Zn and Mn in the muscle, liver and pyloric caeca are well demonstrated, the exact mechanisms of phytoadditives are still only partially understood. More investigations are required to detail the mechanisms involved in phytoadditives this enhancement.
A record of import of the invasive snail Theba pisana (O. F. Müller, 1774) (Gastropoda: Helicidae) in Bulgaria
(Plovdiv University Press “Paisii Hilendarski”, 2024-01-03) Georgiev, Dilian
This is a short communication of a discovery of the invasive Mediterranean snail species Theba pisana among food products in a market in Bulgaria imported from Spain. A single live juvenile specimen was found among lettuce leaves. Later it was alive kept in a terrarium.
Aberrant promoter methylation in p53 and ATM genes was not associated with sporadic breast carcinogenesis in Bulgarian patients
(Plovdiv University Press “Paisii Hilendarski”, 2014-04-02) Krasteva, Maria E.; Antov, Georgi G.; Gospodinova, Zlatina I.; Angelova, Svetla G.; Nacheva, Maria B.; Georgieva, Elena I.; Gavrilov, Ivan G.
Epigenetic silencing of gene expression has become an intensively studied topic regarding breast cancer during the last years. Previous investigations have shown that hypermethylation in gene promoters is an alternative to mutations cancer-related mechanism for inactivation of tumor suppressor gene function. The present study was designed for evaluation of promoter methylation in p53 and ATM tumor suppressor genes in Bulgarian patients with sporadic breast cancer. Sodium bisulfite conversion and methylation-specific PCR were performed on tumor DNA isolated from 55 patients with sporadic breast cancer. The data showed normal profile of methylation in the promoter region of p53 and ATM genes in all studied patients. Cases with hypermethylation were not observed. Our results did not support the involvement of p53 and ATM promoter hypermethylation in the neoplastic pathways of sporadic breast cancer. The lack of promoter hypermethylation in p53 and ATM is suggestive of a greater share of genetic aberrations in loss of tumor suppressor function of these genes and presumes the involvement of other epigenetic cancer mechanisms. To our knowledge this study provides the first data on promoter hypermethylation status of p53 and ATM genes in Bulgarian patients.
Aberrant signature patterns of ATM, γ-H2AX and p53 proteins in the patients exposed to methyl isocyanate diagnosed with gallbladder cancer
(Plovdiv University Press “Paisii Hilendarski”, 2014-04-29) Jatawa, Suresh Kumar; Tiwari, Archana
Cancer of gallbladder is a hidden phenomenon and highly malignant with underprivileged diagnosis and poor survival. Study of cancer patterns amongst victims of Bhopal gas tragedy exposed to methyl isocyanate revealed higher incidence of gallbladder cancer that necessitated a more objective elucidation of the disease at its molecular level. Tissues of 92 cases of gallbladder cancer patients were taken in the study (31 men and 61 women, age range 16–85 years, mean age 45.8±1.50 years). Mutations of ATM, γ-H2AX and p53 were predominantly seen in the methyl isocyanate exposed cohort diagnosed with adenocarcinoma, with 61.4% (43/70), 54.3% (38/70) and 73% (51/70) respectively, involving infiltration into the papillary and mucinous region/cell types of the gallbladder. Out of these, the expression frequency of all the above three genes was higher in moderately differentiated adenocarcinoma in comparison to poorly and well-differentiated ones. The results of the present study support the hypothesis that ATM and p53 mutations provide fundamental genetic signatures influencing tumor behavior across patient subsets and invasiveness of the disease, while γ-H2AX is apparently an ordinary pathway involved in the genesis of tumors.
Abundance and biomass of Cladocera (Crustacea) in Vaya Lake
(Plovdiv University Press "Paisii Hilendarski", 2024-02-27) Nenova, Elena; Stoichev, Stefan
The number and biomass of Cladocera in Vaya Lake during the period 2003 - 2007 was studied under the conditions of increased anthropogenic pressure. The total number of cladocerans by station and by species, as well as their biomass, was determined. A dendrogram of similarity in species and quantitative composition of Cladocera was made. St. 1 and St. 5 are distinguished by the equal and lowest abundance of D. magna, and the very similar and highest abundance of M. micrura. Stations 3, 4, 11, and 12 had the highest Cladocera abundances, which were mainly due to close D. longispina and M. micrura. St. 9, 8, 2 and 7 form one group with more than 83% similarity. They show similar abundances of D. pulex. The dendrogram of similarity in species composition and biomass for the cladocerans showed 75% similarity among all stations except st. 5, which clearly stands out with the lowest total biomass.
Acetylcholinesterase inhibitory, antioxidant, and antimicrobial activities of Salvia tomentosa Mill. essential oil
(Plovdiv University Press “Paisii Hilendarski”, 2015-08-10) Marchev, Andrey; Ivanov, Ivan; Denev, Petko; Nikolova, Milena; Gochev, Velizar; Stoyanova, Albena; Pavlov, Atanas; Georgiev, Vasil
Chemical composition and bioactivity of essential oil from Salvia tomentosa Mill. natively grown in Bulgaria were investigated. GC-MS analysis identified 60 compounds which represented 98% of the oil constituents. The prevalent constituents were monoterpenes with eight dominant compounds being identified: borneol (10.3%), β-pinene (9%), camphor (7.9%), α-pinene (6%), camphene (4%), 1.8-cineole (3.8%), α-limonene (3.5%) and β-caryophyllene (3%). The essential oil showed considerable acetylcholinesterase inhibitory activity (IC50=0.28±0.06 μg/mL), comparable with that of galanthamine. Study of antioxidant activity strongly suggested that the hydrogen atom transfer reaction was preferable over the electron transfer (ORAC=175.0±0.40 μM Trolox equivalents/g oil and FRAP=1.45±0.21 mM Trolox equivalents/g oil). The essential oil showed moderate antifungal and antibacterial activities against Candida albicans and Gram-positive bacteria, whereas it was almost inactive against the investigated Gram-negative strains. The results suggested that the essential oil of Bulgarian S. tomentosa could be considered as a prospective active ingredient for prevention of oxidative stress-related and neurodegenerative disorders in aromatherapy. Because of the high antioxidant capacity, the oil could be considered as natural supplement or antioxidant in cosmetics and food products.
Adenovirus Serotype 5 Vectors with Tyr3-Octreotate Modified as a Virulytic Oncotherapy Agent in AGS Cells
(Plovdiv University Press “Paisii Hilendarski”, 2020-09-17) Salkhori, Najmeh Yarkeh; Farivar, Taghi Naserpour; Noroozi, Jamileh; Najafipour, Reza; Pakzad, Parviz
Background: Oncolytic viral therapy is known as a new promising strategy to treat cancer. Oncolytic viruses (OVs) can replicate in cancer cells, and beside this primary effect, OVs can also stimulate the immune system. Moreover, Adenovirus serotype 5 (Ad5) is widely used as an oncolytic agent for cancer therapy. The present study aimed to make a change in the adenovirus fiber area. Methods: The tyr3-octreotate sequence was inserted into the HI-loop in the adenovirus fiber knob. In addition, recombinant virus was transferred to the HEK-293 packaging cells using the calcium phosphate method; therefore, the new virus was prepared. Accordingly, virus titer was calculated using the TCID50 method. Afterward, recombinant adenovirus and wild-type 5 strain were transferred to perform against human adenocarcinoma gastric cell line (AGS). Subsequently, they were evaluated for cytopathic effects, and the manipulated virus was then confirmed Using PCR and sequencing. Results & Conclusions: In this regard, the obtained results showed that the recombinant adenovirus has a greater ability in infecting AGS cells compared to the wild-type adenovirus. Our data suggest that, modification of Ad5 with tyr3-octreotate expands its usage as an oncolytic agent against the AGS cells.
Aggressive Commercial Practices
(Plovdiv University Press, 2024-05-06) Boneva, Linda
The essay examines the phenomenon of aggressive commercial practices and the legal problems connected with this kind of unfair commercial practices.
Agronomic performances and nutritional composition of three morphotypes of spider plant (Cleome gynandra L.) under different doses of compost
(Plovdiv University Press “Paisii Hilendarski”, 2019-07-15) Kiebre, Zakaria; Traore, Ernest Renan; Kiebre, Mariam; Bationo-Kando, Pauline; Kabore, Dramane; Sawadogo, Boureima; Sawadogo, Mahamadou
Spider plant is an important dietary supplement for the local population of Burkina Faso. The present study aims to evaluate the agronomic and biochemical response of three morphotypes to the variation of compost dose. The split-plot design with three repetitions was used for experiment. Three morphotypes, i.e slightly-violet, green and violet, were evaluated using four doses of compost. The results revealed that the agromorphological traits and biochemical composition vary considerably according to the compost dose. About 6t/ha was identified as the best for biomass production and nutritional profile of spider plant. In general, the agronomic response of morphotypes to the variation of compost dose is not significantly different, except biomass. However, under low fertility conditions, the green morphotype records the best performances whereas in high fertility conditions, the slightly-violet records the best performances. For the biochemical composition, the content of nutrients depends more of compost dose than morphotype.
Allelopathic tolerance in white lupine (Lupinus albus L.) accessions to Sorghum halepense extracts
(Plovdiv University Press “Paisii Hilendarski”, 2019-07-15) Georgieva, Natalia
Modern farming requires a better understanding of the response of species, and in the particular experiment, of accessions, to the influence of weeds in order to develop agricultural systems that are more dependent on ecological interactions and less dependent on the use of pesticides. The present lab study aimed to estimate the tolerance of white lupine accessions to Sorghum halepense extracts on the seed germination and initial growth of the crop. Studied factors were: white lupine accessions – ten levels (Lp01, Lp04, Lp06, Lp10, Lp21, Lp23, Lp25, Lp27, Lp28 Lp29), aqueous extracts – two levels (shoot and root biomass of S. halepense) and concentrations of the extracts – four levels (1.0%, 5.0%, 10.0% and distilled water as control). The results showed a different tolerance of the ten accessions to allelopathic action of the aqueous extracts. Increasing concentrations of the extracts inhibited seed germination (by 5.0 to 10% in the different accessions), elongation and accumulation of primary germ (2.4 to 71.2% and 3.0 to 56.2%, respectively. The GGEbiplot analysis, representing the summary effect of the action of weed extracts on the germination and growth parameters in different concentrations, determined Lp 01, Lp 04 and Lp 10 as tolerant. Sensitivity exhibited Lp 21, Lp 25 and Lp 23. The correlation analysis of data showed that accessions whose seeds had a higher 1000 seeds mass, higher seed vigor index and protein content were less affected by the inhibitory effect of S. halepense extracts, respectively, they exhibited a higher tolerance.
Allelopatic effects of some medicinal plant essential oils on plant seeds germination
(Plovdiv University Press “Paisii Hilendarski”, 2015-11-29) Shokouhian, Ali; Habibi, Hassan; Agahi, Kayvan
The effect of essential oils from some medicinal plants on seed germination was studied with the aim of assessing their potential use as bioherbicides. The experiment was conducted as factorial based on completely randomized design (CRD) with three replications. Seeds of 3 summer crops including lettuce (Lactuca sativa), pepper (Piper longum) and tomato (Solanum lycopersicum) were exposed to essential oils of rosemary (Rosmarinus officinalis), thyme (Thymus vulgaris) and anise (Pimpinella anisum) at 3 different concentrations (25 and 50% diluted and undiluted). Treated seeds were grown in a growth chamber at 25°C for 5 days. The number of germinated seeds in each Petri dish was daily counted. After five days seed germination percentage (Ge) was calculated. Biplot analysis was performed using genotype plus genotype environment interaction (GGE) method. Results showed that the allelopathic effect on Ge was varied among studied plants, which was mainly due to i) differences in the composition of the studied essential oils and ii) different allelopathic effects of the studied essential oils on Ge. Accordingly, compared to the individual use, combining several essential oils would have a greater inhibitory effect on Ge of weeds.

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