331 research outputs found

    Conservation and directed utilization of forest genetic resources

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    Forest genetic resources represent the genetic diversity contained in the thousands of species of forest trees on the earth. their conservation is a set of activities and strategies, which are performed in the aim of ensuring the continued existence, evolution and availability of these resources for the present and future generations. the aim of genetic resource management is the enhancement of conditions for the continual evolution of the species which is the defensive mechanism of the organisms in the struggle with environmental changes

    Female power that protects: Examples of the apotropaic and decorative functions of the Medusa in Roman visual culture from the territory of the Central Balkans

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    Meduza ili Gorgona imala je tokom antičkog perioda u rimskoj vizuelnoj umetnosti zaštitnički, ali i izrazit dekorativni karakter. Nj eno poreklo treba tražiti među praistorijskim boginjama prirode, te stoga nije neuobičajena njena bliskost sa boginjama kao što su Boginja Majka, Rea, Kibela, Demetra ili materinska Artemida. Meduza je od arhajskog do kasnoantičkog perioda doživela brojne transformacije koje se mogu tretirati kao jedinstveni primerak evolucije lika. Demonsko biće široke glave sa naglašenom bradom, velikim ustima i isplaženim jezikom prerasta tokom helenističkog perioda u ženu izuzetne lepote sa diskretno naznačenim zmijama u kosi ili sa samo nagoveštenim rogovima na glavi. U pojedinim eshatološko-filozofskim pravcima različite je tumačena njena uloga. Prema orfičarima, Meduza se nalazila na vratima pakla i tretirana je u okviru mesečevog kulta. Prema pitagorejcima imala je ulogu da hrabri ljude na njihovom putu preko Okeana do ostrva Blaženih. Za stoičare, Meduza je bila personifikacija straha kojeg pobeđuje mitski junak Persej. Gorgonin pogled imao je za cilj da ubije pohotljive, životinjske nagone kod ljudi, dok je kod muškaraca obuzdavao njihovu muškost, ali nije imao efekta na žene. Tokom rimske epohe, u arhitektonskoj i sitnoj, zanatskoj umetnosti Meduza je isključivo predstavljana kao lepa žena sa diskretnim zmijama u kosi i s krilima na glavi. Najzastupljenija je na spomenicima funerarnog karaktera (stele i sarkofazi), na kojima je zadržala prvobitni karakter "one koja posmatra", štiti i zastrašuje sve potencijalne uništitelje groba. Glava Meduze na mozaiku iz ulaza u triklinijum vile sa peristilom u Medijani ima funkciju zaštite prolaza. Među predmetima sitne zanatske umetnosti, Meduza uglavnom krasi vojničku opremu (oklop) i oružje (umbo štita). U tim situacijama, lik Meduze imao je za cilj da štiti vojnika od svih nedaća, a pre svega od pogibije. Apotropejska moć Meduze bila je za Rimljane toliko značajna da je predstava glave Meduze postala deo nekakvog ličnog kulta, jer je nošena u okviru nakita, pa je često bila dekoracija kameja i gema na prstenju, naušnicama i medaljonima. Lik ljupke žene na nakitu namenjenom ženama ima jedno dodatno svojstvo, koje je pre svega vezano za zaštitu nežnog ženskog bića, jer, kao što se saznaje iz mita o Perseju, Meduza je zastrašivala muškarce, a nikako žene, te se stoga može tretirati i kao zaštitnica žena. U narodnoj tradiciji Srba zabeležene su dve legende zahvaljujući kojima je lik Meduze nastavio svoj vizuelni i simbolički život na zidovima pravoslavnih manastira Rukumija i Nimnik (kod Požarevca) - dva zabata nadgrobnih stela sa glavom Meduze upotrebljena su kao spolije na fasadama navedenih manastira. Biće apotropejskog karaktera je tako, preko narodne tradicije, prihvaćeno u hrišćanskom svetu kao trijumf pravde, pokajanja i kažnjavanja krivaca, usaglašavajući pagansko sa hrišćanskim religioznim idejama.The motif of Medusa had significant importance in Roman visual culture, reflecting the comprehension of ancient people about this frightful being. Visual material from the territory of the Central Balkans suggests a widely known understanding and belief of the protective as well as apotropaic functions of Medusa. The motif of Medusa i.e. the Gorgoneion, was one of the well known and most represented motifs in architecture, funerary art and artiminori and a widely appreciated decoration of jewelry, signifying the importance of Medusa's protection for people, especially for women

    Interleukin 8 and matrix metalloproteinases 2 and 9 as markers of invasiveness in hormone dependent breast cancer

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    Ekspresija receptora za estrogen (ER) i receptora za progesteron (PR) je preduslov hormonske zavisnosti karcinoma dojke. Hormonski receptori su još uvek jedni od najpouzdanijih parametara prognoze i predikcije ovog karcinoma, mada su klinički ishod pacijentkinja i odgovor na hormonsku terapiju varijabilni. Uključivanje receptora za humani epidermalni faktor rasta 2 (HER2) u klasifikaciju karcinoma dojke zajedno sa hormonskim receptorima, samo je donekle doprinelo utvrđivanju preciznijeg prognostičkog profila, što je ukazalo na potrebu za traženjem dodatnih, selektivnijih markera prognoze i predikcije. Prognostički značaj potencijalnih biomarkera se najbolje sagledava praćenjem prirodnog toka bolesti tj. toka bolesti koji nije bio prekidan adjuvantnom (postoperativnom) terapijom. O prirodnom toku bolesti karcinoma dojke ima vrlo malo literaturnih podataka s obzirom da se u savremenoj kliničkoj praksi svim pacijentkinjama daje neki oblik adjuvantne terapije. Literaturni podaci ukazuju na značaj interleukina 8 (IL8) i matriksnih metaloproteinaza 2 i 9 (MMP2, MMP9) kao potencijalnih biomarkera prognoze i predikcije u različitim tipovima humanih kancera. Studije koje se odnose na hormonsku regulaciju ekspresije ovih potencijalnih biomarkera u karcinomu dojke su kontroverzne. Više studija je ukazalo da bi ovi biomarkeri mogli biti potencijalni indikatori rezistencije na hormonsku terapiju. Ciljevi: Ciljevi istraživanja su bili: da se ispita prognostički i prediktivni značaj kliničkopatoloških parametara i odabranih biomarkera (IL8, MMP2, MMP9); da se proceni da li i na koji način interakcije između ER, PR i HER2 kao glavnih determinanti karcinoma dojke, imaju uticaja na ekspresiju odabranih biomarkera; da se proceni eventualno postojanje sprege između odabranih biomarkera, što bi moglo doprineti razumevanju progresije hormonski zavisnog karcinoma dojke i objašnjenju rezistencije na hormonsku terapiju...Expression of estrogen receptor (ER) as well as progesterone receptor (PR) is the prerequisite of hormonal dependence of breast cancer. Hormone receptors are still among the most reliable prognostic and predictive parameters of this cancer, although the clinical outcome of patients and the response to hormonal therapy are variable. Inclusion of human epidermal growth factor receptor 2 (HER2) in the classification of breast cancer together with hormone receptors, only partly contributed to the determination of more precise prognostic profile, which pointed out the need for searching additional, more selective prognostic and predictive markers. The best way to evaluate the prognostic significance of potential biomarkers is by following the natural course of the disease – the course that hadn’t been interrupted by adjuvant (postoperative) therapy. Very few literature data is available regarding this issue as some kind of adjuvant therapy is given to all breast cancer patients nowadays. Literature data have indicated the significance of interleukin 8 (IL8) and matrix metalloproteinase 2 and 9 (MMP2, MMP9) as potential prognostic and predictive biomarkers in different types of human cancers. Available data regarding hormonal regulation of expression of these potential biomarkers in breast cancer are controversal. Many studies have indicated that these biomarkers could be potential indicators of resistance to hormonal therapy. Aims: The aims of this study were: to evaluate the prognostic and predictive significance of clinicopathological parameters and selected biomarkers (IL8, MMP2, MMP9); to examine if and how interactions among ER, PR and HER2 as the main determinants of breast cancer influence the expression of selected biomarkers; to examine the possible existence of feedback between selected biomarkers, which might contribute to understanding of progression of hormone dependent breast cancer as well as to the explaination of resistance to hormonal therapy..

    Cytomegalovirus infection and pathogenesis TI оf experimental autoimmune encephalomyelitis

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    BALB/c miševi su, za razliku od C57BL/6 miševa, relativno rezistentni na indukciju eksperimentalnog autoimunskog encefalomijelitisa (EAE) imunizacijom peptidom MOG35-55. U ovoj studiji je po prvi put pokazano da i neonatalna infekcija mišjim Sytomegalovirus-om (MCMV) i infekcija u adultnom dobu prekida ovu rezistenciju. Inficirani BALB/c miševi imunizovani peptidom MOG35-55 su razvili kliničke i histološke karakteristike EAE slične onim koji se razvijaju u osetljivom soju miševa, C57BL/6. U infiltratima CNS-a BALB/c miševa inficiranih virusom i imunizovanih peptidom MOG35-55 su pored CD4+ limfocita u značajnom procentu nađeni i CD8+ limfociti, slično nalazima kod obolelih od multiple skleroze (MS). CD8+ limfociti izolovani iz infiltrata CNS-a obolelih miševa koji su u odgovoru na ex vivo restimulaciju MOG35-55 peptidom odgovorili produkcijom citokina nisu specifični za virusne epitope pp89 i m164. MCMV infekcija BALB/c miševa stimuliše razvoj proinflamacijskog fenotipa dendritskih ćelija (CD86+CD40+CD11c+) u perifernim limfnim organima, M1 tipa mikroglije u CNS-u, i encefalitogenih Th1/Th17 ćelija. Ova studija ukazuje da Sytomegalovirus, stimulacijom razvoja proinflamacijskog fenotipa ćelija koje prikazuju antigene i Th1/Th17 i CD8 odgovora na MOG35-55 peptid, pojačava autoimunske procese u CNS-u i ukida rezistenciju na razvoj EAE.In contrast to C57BL/6 mice, BALB/c mice are relatively resistant to the induction of experimental autoimmune encephalomyelitis (EAE) after challenge with MOG35-55 peptide. Here we provide the first evidence that both neonatal and adult infection with murine cytomegalovirus (MCMV) abrogates this resistance. Infected BALB/c mice developed clinical and histological signs similar to those seen in susceptible C57BL/6 mice. In addition to CD4+ cells large proportion of cells in the infiltrate of diseased BALB/c mice were CD8+, similar with findings in multiple sclerosis (MS). CD8+ cells that responded to ex vivo restimulation with MOG35-55 were not specific for viral epitopes pp89 and m164. MCMV infection favors proinflammatory type of dendritic cells (CD86+CD40+CD11c+) in the peripheral lymph organs, M1 type of microglia in CNS, and polarization to Th1/Th17 encephalitogenic cells. This study indicates that CMV may enhance autoimmune neuropathology and abrogate inherent resistance to EAE in mouse strain by enhancing proinflammatory phenotype of antigen presenting cells and Th1/Th17 and CD8 response to MOG35-55

    Trametes suaveolens as ligninolytic enzyme producer

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    Species of the genus Trametes represent one of the most efficient lignin-degraders which can be attributed to a well developed ligninolytic enzyme system. Current trends are screening of ability of new species to produce these enzymes, as well as the optimization of conditions for their overproduction. Therefore, the aim of the study was to evaluate the potential of T. suaveolens to synthesize laccase and Mn-oxidizing peroxidases during fermentation of the selected plant raw materials. Level of enzyme activities was measured on 7, 10 and 14th day of submersion, as well as the solid-state fermentation of wheat straw and oak sawdust in the presence of NH4NO3 in previously determined optimal nitrogen concentration of 25 mM. The enzyme activity was determined spectrophotometrically using ABTS and phenol red as the substrates. The highest level of laccase activity (1087.1 U/L) was noted after 7 days of wheat straw solid-state fermentation, while during the submerged cultivation the production of the enzyme was not noted. Submerged cultivation in oak sawdust-enriched medium was the optimal for activity of Mn-dependent peroxidase (1767.7 U/L on day 14) and Mn-independent peroxidase (1113.7 U/L on day 7). Introduction of T. suaveolens to produce ligninolytic enzyme represented the base for further study, as well as the determination of relation between enzyme activity and rate of lignin degradation. It could lead to greater possibility of fungal species selection with high delignification capacity, which could take participation in sustainable production of food, feed, fibres, and energy, environmentally friendly pollution prevention, and bioremediation

    USER DEFINED GEOMETRIC FEATURE FOR THE CREATION OF THE FEMORAL NECK ENVELOPING SURFACE

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    There is a growing demand for application of personalized bone implants (endoprostheses or macro-scaffolds, and fixators) which conform the anatomy of patient. Hence the need for a CAD procedure that enables fast and sufficiently accurate digital reconstruction of the traumatized bone geometry. Research presented in this paper addresses digital reconstruction of the femoral neck fracture. The results point out that User-Defined (geometric) Feature (UDF) concept is the most convenient to use in digital reconstruction of numerous variants of the same topology, such as in this kind of bone region. UDF, named FemoNeck, is developed to demonstrate capability of the chosen concept. Its geometry, controlled by a dozen of parameters, can be easily shaped according to anatomy of femoral neck region of the specific patient. That kind of CAD procedure should use minimally required set of geometric (anatomical) parameters, which can be easily captured from X-ray or Computed Tomography (CT) images. For the statistical analysis of geometry and UDF development we used CT scans of proximal femur of 24 Caucasian female and male adults. The validation of the proposed method was done by applying it for remodeling four femoral necks of four different proximal femurs and by comparing the geometrical congruency between the raw polygonal models gained directly from CT scan and reconstructed models

    REVIEW OF BONE SCAFFOLD DESIGN CONCEPTS AND DESIGN METHODS

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    The paper brings out a review of existing, state-of-the-art approaches to designing the geometry of the scaffolds that are used for tissue engineering with a special emphasis on the macro scaffolds aimed for bone tissue recovery. Similar concepts of different authors are organized into groups. The focus of the paper is on determining the existing concepts as well as their advantages and disadvantages. Besides the review of scaffolds' geometry solutions, the analysis of the existing designs points to some serious misconceptions regarding the scaffold role within the (bone) tissue recovery. In the last section of the paper, the main requirements regarding geometry, that is, architecture and corresponding mechanical properties and permeability are reconsidered

    M-Gam Model Based Evaluation of Gradac River Gorge for Geotourism Development

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    The results obtained through evaluation of the Gradac River Gorge by applying the M-GAM model are presented in this study. The main goal of the research was to observe current state and explore possibilities for geotourism development in this area. By virtue of numerous indicators and sub-indicators, which are categorized either in group of Main or Additional values, this methodology gives us good insight in potentials of geoturism development. In addition, the methodology has been improved by involving tourists. This approach offers a more objective perspective of the needs of tourists and provides a starting point for further research. Recently, Serbia has been included in UNESCO’s Global Geopark Network due to the Djerdap Gorge being made the country’s first geopark. The Gradac Gorge is equally valuable; it has vast geoheritage, extraordinary landscapes, lush vegetation, and rich cultural and historical heritage. The geomorphological uniqueness of Gradac is the distinct meandering of the lower part of the river valley. Considering that it’s also a protected area (a Landscape of Outstanding Features), a valuable fishing area, and one of the most important tourist sites in Valjevo Region, it has high potential to become one of Serbia’s future Geoparks. The obtained results show the gorge having exceptional potential for geotourism development. On the other hand, it’s necessary to improve the guide service, the visitor center, and more additional values

    Influence of fertilization on Miscanthus x giganteus (Greef et Deu) yield and biomass traits in three experiments in Serbia

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    Miscanthus x giganteus (Greef et Deu) is an agro-energy crop of the second generation cultivated in purpose to obtain annually renewable bio-fuel produced from the aboveground biomass. Cultivation is preferred on marginal lands to avoid occupation of arable lands. Influence of fertilization and soil type Gleysol, Planosol and Technosol (open pit coal mine overburden) on yield and biomass traits of miscanthus were investigated during five years' field experiment. Among biometric characteristics: stem height, length and width of leaves, the number of leaves (dry and green) per stem and number of stems per rhizome, only the last one has a strong positive correlation with yield. Fertilization increased yield during fourth and fifth year of development on Gleysol and Technosol. The highest yield on Gleysol was 23.12 t/ha in 2014, on Planosol 10.16 t/ha, and 4.77 t/ha in 2015 on Technosol. The yield of miscanthus, beside fertilization, depends on weather conditions and weeds. Cultivation of miscanthus is possible on marginal soils with minimum application of agricultural measures only in the year of establishment. Gleysol is a type of soil that can be recommended for miscanthus cultivation
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