53 research outputs found
The emergence of new localities of Orobanche bartlingii Griseb. in the Silesian-Cracow Upland as a result of the spreading of Libanotis pyrenaica (L.) Bourgh. due to changes in land use : [poster]
During the last few decades, many cultivated fields and grazed grasslands have disappeared in the Silesian-
Cracow Upland. Therefore, abandoned lands occupy now a large area there. As a result of these changes, some plant species have significantly increased the area of occurrence.
Libanotis pyrenaica is one of them. In many places it begins to behave like an expansive species (Fragment tekstu)
A homology model of restriction endonuclease SfiI in complex with DNA
BACKGROUND: Restriction enzymes (REases) are commercial reagents commonly used in recombinant DNA technologies. They are attractive models for studying protein-DNA interactions and valuable targets for protein engineering. They are, however, extremely divergent: the amino acid sequence of a typical REase usually shows no detectable similarities to any other proteins, with rare exceptions of other REases that recognize identical or very similar sequences. From structural analyses and bioinformatics studies it has been learned that some REases belong to at least four unrelated and structurally distinct superfamilies of nucleases, PD-DxK, PLD, HNH, and GIY-YIG. Hence, they are extremely hard targets for structure prediction and homology-based inference of sequence-function relationships and the great majority of REases remain structurally and evolutionarily unclassified. RESULTS: SfiI is a REase which recognizes the interrupted palindromic sequence 5'GGCCNNNN^NGGCC3' and generates 3 nt long 3' overhangs upon cleavage. SfiI is an archetypal Type IIF enzyme, which functions as a tetramer and cleaves two copies of the recognition site in a concerted manner. Its sequence shows no similarity to other proteins and nothing is known about the localization of its active site or residues important for oligomerization. Using the threading approach for protein fold-recognition, we identified a remote relationship between SfiI and BglI, a dimeric Type IIP restriction enzyme from the PD-DxK superfamily of nucleases, which recognizes the 5'GCCNNNN^NGGC3' sequence and whose structure in complex with the substrate DNA is available. We constructed a homology model of SfiI in complex with its target sequence and used it to predict residues important for dimerization, tetramerization, DNA binding and catalysis. CONCLUSIONS: The bioinformatics analysis suggest that SfiI, a Type IIF enzyme, is more closely related to BglI, an "orthodox" Type IIP restriction enzyme, than to any other REase, including other Type IIF REases with known structures, such as NgoMIV. NgoMIV and BglI belong to two different, very remotely related branches of the PD-DxK superfamily: the α-class (EcoRI-like), and the β-class (EcoRV-like), respectively. Thus, our analysis provides evidence that the ability to tetramerize and cut the two DNA sequences in a concerted manner was developed independently at least two times in the evolution of the PD-DxK superfamily of REases. The model of SfiI will also serve as a convenient platform for further experimental analyses
O współczesnym statusie kulturoznawstwa: prolegomena do dyskusji. W kontekście Kongresu Polskiego Kulturoznawstwa, Wrocław, 16–17 lutego 2018
Prolegomena do zaganień kondycji oraz przyszłości nauk o kulturze, dyscyplin kulturoznawczych i ośrodków kulturoznawczych w Polsce poruszanych podczas Kongresu Polskiego Kulturoznawstwa
Management of expenditure on the development of higher education – Poland as compared to EU countries
Purpose: The objective of the article is to identify, analyse and diagnose the current state of management of expenditure on the development of higher education in Poland as compared to other EU countries, and thus to indicate the necessary changes and recommendations. Design/Methodology/Approach: The research relied mainly on data on the number of students and universities, enrolment, and expenditure on higher education. Polish and foreign data sources were applied to determine diversity of the distribution of students in Poland among public and private universities as well as the dynamics of the changes. In comparison to other EU countries, the changes in the coefficients of the level of higher education were analysed and the enrolment indices were compared with the indices of human development. Expenditure on higher education was examined with various approaches. In the study, statistical methods were used to describe the current trends. Findings: During the study period, the structure of tertiary education, measured by the ratio of state-owned to private universities, changed from 95:5 to 34:66. However, in terms of the number of students, state-owned universities played a dominant role. In this case, the proportions hardly changed during the study period and were 77:23 at its end. Since 2007, a slowdown in the increase in the number of students has been observed in Poland, and since 2010 the same tendency was observed in the number of universities. Practical Implications: In the long-term Polish education will develop efficiently, strengthen Poland's integration in Europe and, as a result, translate into the qualitative development of higher education in Poland. Originality/value: Knowledge of trends and levels of development of higher education, defining the role of the state as compared to the other members of the EU are important for policymakers, helping them consciously to identify prospects for development, and thus effectively manage expenses by minimizing existing risks.peer-reviewe
Study of the nature and dynamics of processes in terms of fractals on the example of selected joint stock companies
PURPOSE: The main purpose of the article is to highlight the role and impact on modern
management of natural processes of knowledge about their nature.DESIGN/METHODOLOGY/APPROACH: The authors accepted the thesis that complex processes
which contemporary management encounters should be solved with the use of complex
formal tools.PRACTICAL IMPLICATIONS: Thanks to the new and formal paradigms of modern science we are
able to penetrate deeper into the nature of the real processes (economic, social, banking and
even into the nature of the stock exchange - which was studied) and their complexity
(structure).ORIGINALITY/VALUE: The originality of the content of the article lies in the combination of
theoretical concepts related to the research on the fractal nature of some reality processes
with empirical research.peer-reviewe
Mechanism of polypurine tract primer generation by HIV-1 reverse transcriptase
HIV-1 reverse transcriptase (HIV-1 RT) possesses both DNA polymerase activity and RNase H activity that act in concert to convert single-stranded RNA of the viral genome to double-stranded DNA that is then integrated into the DNA of the infected cell. Reverse transcriptase-catalyzed reverse transcription critically relies on the proper generation of a polypurine tract (PPT) primer. However, the mechanism of PPT primer generation and the features of the PPT sequence that are critical for its recognition by HIV-1 RT remain unclear. Here, we used a chemical crosslinking method together with MD simulations and single-molecule assays to study the mechanism of PPT primer generation. We found that the PPT was specifically and properly recognized within covalently tethered HIV-1 RT-nucleic acid complexes. These findings indicated that recognition of the PPT occurs within a stable catalytic complex after its formation. We found that this unique recognition is based on two complementary elements that rely on the PPT sequence: RNase H sequence preference and incompatibility of the poly-rA/dT tract of the PPT with the nucleic acid conformation that is required for RNase H cleavage. The latter results from rigidity of the poly-rA/dT tract and leads to base-pair slippage of this sequence upon deformation into a catalytically relevant geometry. In summary, our results reveal an unexpected mechanism of PPT primer generation based on specific dynamic properties of the polyrA/dT segment and help advance our understanding of the mechanisms in viral RNA reverse transcription
Global value chains: Potential synergies between external trade policy and internal economic initiatives to address the strategic dependencies of the EU
Global value chains enable two-thirds of international trade, notably for the EU. The EU
wants to preserve its commercial links with third countries and organisations to make
up for trade disruptions. This study examines sustainable supply of raw materials,
commodities, and critical goods using the EU's Open Strategic Autonomy concept. It
examines which raw material are crucial for sustainable supply and necessary for the
green transition. The paper examines EU internal legislation and international
cooperation instruments to determine the EU's disruption risk. It evaluates the
economic impact of EU preferential trade agreements on raw material availability. The
study illustrates the political and economic relevance of raw material partnerships and
plurilateral and bilateral trade agreements. It analyses the EU's toolbox for
safeguarding its interests and making independent trade choices to counteract other
actors' unfair practices and intervention. Finally, the paper examines regulatory
frameworks, international alliances, and activities to find ways to strengthen global
value chains in critical EU industries
The analysis of coexistence of celiac disease and vulvar lichen sclerosus in girls
Objectives: Vulvar lichen sclerosus (VLS) is a chronic inflammatory disease of unclear etiology. Recent studies show that 15–34% of cases in adult women and 14% in girls coexist with allergies or autoimmune diseases, among others — celiac disease (CD). Most of the research on the coexistence of VLS and autoimmune diseases has been carried out on a group of adult women. Literature data on this issue are very scarce.Material and methods: The presented work is a pioneering project in which we tried to elucidate a possible relationship between celiac disease and lichen sclerosus in girls. The aim of the research was to study the antibodies characteristic of celiac disease in girls with VLS. The control group consisted of 35 heathy adolescent girls and the study group consistedof 20 girls aged 2–18 years old diagnosed with vulvar lichen sclerosus recruited at the Gynecological Clinic for Girls at the Women’s Health Center in Katowice.Results: There were no significant differences in the concentrations of antibodies characteristic for CD in the blood serum between the studied groups.Conclusions: The main limitation of our study was the small size of the study group. It is therefore legitimate to conduct further research on a larger study group to find themutual correlations between the analyzed antibodies and the onset and the course of VLS in girls. The finding of a positive correlation between the coexistence of VLS and CD may prevent potentially serious, long-term complications
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