95 research outputs found
The Use of Selected Methods of Linear Ordering to Assess the Innovation Performance of the European Union Member States
The growing interest in measuring economic and social phenomena that are difficult to observe directly increases the need for researchers to broaden the use of multivariate statistical analysis methods. The ease of interpreting results presented in the form of rankings makes it common practice to use different methods of linear ordering of objects. If the appropriate assumptions are met, the determined set of variables allows for the construction of a synthetic measure whose ordered values provide a ranking. Such a statistical approach is quite often used in assessing the level of innovativeness of economies, and the literature abounds in various innovation indices. The starting point of this paper is a set of 27 variables on the basis of which the Summary Innovation Index is developed. After verifying the statistical assumptions and reducing the database to 21 diagnostic factors, the authors construct a total of nine innovation rankings, using different methods of linear ordering and selected procedures for normalisation of variables. The aim of the paper is therefore to assess the impact of selected methods of linear ordering (Hellwig’s method, TOPSIS method, GDM method) and various procedures for normalising variables (classic standardisation, positional standardisation, quotient transformation) on the final ranking of the EU Member States due to the level of their innovation performance. The obtained results confirm that the applied method of linear ordering and the selection of the normalisation procedure have an impact on the final ranking of the examined objects – in this case, the final ranking of the EU Member States due to the level of their innovativeness analysed in the presented research
PAHs, PCBs, PBDEs and Pesticides in Cold-Pressed Vegetable Oils
The aim of this study was to investigate levels of polychlorinated biphenyls (marker and dioxin-like congeners), polycyclic aromatic hydrocarbons (EPA 15 + 1), polybrominated diphenyl ethers (14 predominant congeners) and pesticides (74 compounds) in various cold-pressed vegetable oils. Poppy seed oil, rapeseed oil, sesame seed oil, pumpkinseed oil, hempseed oil, linaire oil, borage oil and evening star oil were investigated. Results of this study revealed that concentrations of PCBs, PBDEs and PAHs were low in majority of the investigated samples. However, high concentrations of organophosphorus insecticides were found. Chlorpyrifos methyl and pirimiphos methyl were the pesticide residues most commonly found in the studied oils. Concentration of 15 + 1 EPA PAHs was within the 17.85–37.16 μg kg−1 range, concentration of (marker) PCBs varied from 127 to 24,882 pg g−1, dioxin-like TEQ values were below 0.1 pg TEQ g−1. Concentration of PBDEs was below LOQ in most cases
Multiple Wnts Redundantly Control Polarity Orientation in Caenorhabditis elegans Epithelial Stem Cells
During development, cell polarization is often coordinated to harmonize tissue patterning and morphogenesis. However, how extrinsic signals synchronize cell polarization is not understood. In Caenorhabditis elegans, most mitotic cells are polarized along the anterior-posterior axis and divide asymmetrically. Although this process is regulated by a Wnt-signaling pathway, Wnts functioning in cell polarity have been demonstrated in only a few cells. We analyzed how Wnts control cell polarity, using compound Wnt mutants, including animals with mutations in all five Wnt genes. We found that somatic gonadal precursor cells (SGPs) are properly polarized and oriented in quintuple Wnt mutants, suggesting Wnts are dispensable for the SGPs' polarity, which instead requires signals from the germ cells. Thus, signals from the germ cells organize the C. elegans somatic gonad. In contrast, in compound but not single Wnt mutants, most of the six seam cells, V1–V6 (which are epithelial stem cells), retain their polarization, but their polar orientation becomes random, indicating that it is redundantly regulated by multiple Wnt genes. In contrast, in animals in which the functions of three Wnt receptors (LIN-17, MOM-5, and CAM-1) are disrupted—the stem cells are not polarized and divide symmetrically—suggesting that the Wnt receptors are essential for generating polarity and that they function even in the absence of Wnts. All the seam cells except V5 were polarized properly by a single Wnt gene expressed at the cell's anterior or posterior. The ectopic expression of posteriorly expressed Wnts in an anterior region and vice versa rescued polarity defects in compound Wnt mutants, raising two possibilities: one, Wnts permissively control the orientation of polarity; or two, Wnt functions are instructive, but which orientation they specify is determined by the cells that express them. Our results provide a paradigm for understanding how cell polarity is coordinated by extrinsic signals
Coordination of Cell Differentiation and Migration in Mathematical Models of Caudal Embryonic Axis Extension
Vertebrate embryos display a predominant head-to-tail body axis whose formation is associated with the progressive development of post-cranial structures from a pool of caudal undifferentiated cells. This involves the maintenance of active FGF signaling in this caudal region as a consequence of the restricted production of the secreted factor FGF8. FGF8 is transcribed specifically in the caudal precursor region and is down-regulated as cells differentiate and the embryo extends caudally. We are interested in understanding the progressive down-regulation of FGF8 and its coordination with the caudal movement of cells which is also known to be FGF-signaling dependent. Our study is performed using mathematical modeling and computer simulations. We use an individual-based hybrid model as well as a caricature continuous model for the simulation of experimental observations (ours and those known from the literature) in order to examine possible mechanisms that drive differentiation and cell movement during the axis elongation. Using these models we have identified a possible gene regulatory network involving self-repression of a caudal morphogen coupled to directional domain movement that may account for progressive down-regulation of FGF8 and conservation of the FGF8 domain of expression. Furthermore, we have shown that chemotaxis driven by molecules, such as FGF8 secreted in the stem zone, could underlie the migration of the caudal precursor zone and, therefore, embryonic axis extension. These mechanisms may also be at play in other developmental processes displaying a similar mode of axis extension coupled to cell differentiation
The Role of Glypicans in Wnt Inhibitory Factor-1 Activity and the Structural Basis of Wif1's Effects on Wnt and Hedgehog Signaling
Proper assignment of cellular fates relies on correct interpretation of Wnt and Hedgehog (Hh) signals. Members of the Wnt Inhibitory Factor-1 (WIF1) family are secreted modulators of these extracellular signaling pathways. Vertebrate WIF1 binds Wnts and inhibits their signaling, but its Drosophila melanogaster ortholog Shifted (Shf) binds Hh and extends the range of Hh activity in the developing D. melanogaster wing. Shf activity is thought to depend on reinforcing interactions between Hh and glypican HSPGs. Using zebrafish embryos and the heterologous system provided by D. melanogaster wing, we report on the contribution of glypican HSPGs to the Wnt-inhibiting activity of zebrafish Wif1 and on the protein domains responsible for the differences in Wif1 and Shf specificity. We show that Wif1 strengthens interactions between Wnt and glypicans, modulating the biphasic action of glypicans towards Wnt inhibition; conversely, glypicans and the glypican-binding “EGF-like” domains of Wif1 are required for Wif1's full Wnt-inhibiting activity. Chimeric constructs between Wif1 and Shf were used to investigate their specificities for Wnt and Hh signaling. Full Wnt inhibition required the “WIF” domain of Wif1, and the HSPG-binding EGF-like domains of either Wif1 or Shf. Full promotion of Hh signaling requires both the EGF-like domains of Shf and the WIF domains of either Wif1 or Shf. That the Wif1 WIF domain can increase the Hh promoting activity of Shf's EGF domains suggests it is capable of interacting with Hh. In fact, full-length Wif1 affected distribution and signaling of Hh in D. melanogaster, albeit weakly, suggesting a possible role for Wif1 as a modulator of vertebrate Hh signaling
Determination of marker and dioxin-like polychlorinated biphenyls in grains of selected cereals and cereal products
Celem pracy była ocena zawartości polichlorowanych bifenyli (PCB) w ziarnie pszenicy i jęczmienia oraz w otrębach
pszennych dostępnych na rynku krajowym. W badaniach wykorzystano wysokorozdzielczy układ do chromatografii gazowej
sprzęgnięty z niskorozdzielczym spektrometrem mas z pułapką jonową. Badano 7 wskaźnikowych kongenerów PCB oraz 12
kongenerów o własnościach analogicznych do dioksyn (tzw. dioksynopodobnych). Stwierdzono niskie stężenia PCB w badanych
produktach zbożowych; tj. suma 7 wskaźnikowych PCB w żadnej z analizowanych próbek nie przekraczała wartości
1 ng g-1. Stężenie dioksynopodobnych kongenerów PCB wyrażone jako równoważnik toksyczności WHO-TEQ w żadnej
z analizowanych próbek nie przekraczało wartości 0,4 pg TEQ g-1.The aim of this study was to evaluate the content of polychlorinated biphenyls (PCBs) in wheat and barley grain and
wheat bran samples collected from the domestic market. High resolution gas chromatographic system coupled to a low
resolution ion trap mass spectrometer was used for the purpose of this study. Seven so-called marker and twelve dioxin
analogue (dioxin-like) PCB congeners were determined. The results indicated low concentrations of PCBs in the analyzed
cereal products: concentration of 7 marker PCBs did not exceed value of 1 ng g-1 in any sample. Concentration of PCB
dioxin-like congeners expressed as a Toxic Equivalent WHO-TEQ did not exceed 0.4 pg TEQ g-1 in any sample
Analysis of procurement of selected agricultural products in Poland in the years 2010-2016
Economic development is characterised by the fact that the share of agriculture tends to decrease both in terms of resources used and domestic product generated. This does not mean, however, that the role of agriculture in the economic development diminishes. It can be considered a paradox that the lower the share of agriculture in the national economy, the greater its role, as it provides raw materials for the production of goods, especially food, which meet the needs of the ever-growing community. The main aim of the presented study is to measure and evaluate changes in agricultural produce procurement in Poland in the years 2010-2016. The following research hypothesis is put forward in the study: Changes in the procurement volume had a much greater impact on the procurement value of selected agricultural produce in Poland in the period considered than changes in the level of transaction prices. In the paper, a comparative analysis of procurement of crop and animal products was conducted. The research process was based primarily on data derived from official statistics obtained from the Central Statistical Office and the Eurostat database regarding procurement of agricultural produce carried out by commercial entities and processing plants. This information is presented in qualitative and quantitative terms for total agriculture, as well as for individual voivodeships
Macroeconomic stability and the level of competitiveness in EU member states: a comparative dynamic approach
Research background: The choice of the issue of international competitive-ness of economies as the research problem addressed in this paper has been mainly dictated by the changes observed in the nature of the development of EU economies and the need to assess the competitiveness of the Polish economy. It is time to evaluate and learn from the largest enlargement in the history of the EU which took place in May 2004. An assessment of changes in the state of EU economies, including the Polish economy, is in the centre of research interest of many scientists. National competitiveness is the subject of a great deal of research and economic studies. Integration and globalisation processes in the world economy are the main reasons for the popularity of this topic. The efficient use of sources and factors determining the competitiveness of economies, sectors and enterprises is associated with prosperity over the long term. One of the methods based on the observation of selected basic indicators of economic competitiveness is the method of analysis called the macroeconomic stabilisation pentagon. The method illustrates the extent to which the government achieves five macroeconomic objectives. It is very difficult, if not impossible, to meet all these objectives at the same time. The difficulty of meeting all these goals concurrently is due to the fact that they are more or less competitive rather than complementary. The proposed assessment of competitiveness based on the developed model of macroeconomic stabilisation pentagon is a unique approach in terms of discussion of country's competitiveness. This approach significantly distinguishes the current study in comparison with standard international reports on competitiveness such as the Global Competitiveness Index or the EU Regional Competitiveness Index.
Purpose of the article: The main aim of the paper is to assess the competitiveness of EU economies in the years 2005-2018, based on a selected set of diagnostic variables referring to the concept of macroeconomic stabilisation pentagon. The paper also formulates a detailed list of four research hypotheses.
Methods: In order to characterise the competitiveness of the European Union economies, including the EU-15 and EU-13 groups, as well as the Visegrad group, six diagnostic variables affecting the economic situation of individual EU countries were analysed. The variables for analysis were chosen so as to reliably describe the competitive position of a given country, at the same time referring in a substantive sense to the concept of macroeconomic stabilisation pentagon. The linear ordering of objects was made using the reference Hellwig method. The selected method enabled the development of competitiveness rankings of EU Member States in the years 2005, 2009, and 2018.
Findings & Value added: The comparative analysis of the main macroeconomic indicators conducted in the paper forms the basis for assessing the current state of the EU economy in relation to other countries. In the paper, the authors depart from the standard elaboration of 'magic pentagon.' Instead, they apply the variables used in the macroeconomic stabilisation pentagon analysis to develop competitiveness rankings of EU Member States. The con-ducted empirical study has confirmed that the 15th anniversary of EU member-ship had a decidedly positive impact on the level of economic development of the EU-13 countries
The Use of Selected Methods of Linear Ordering to Assess the Innovation Performance of the European Union Member States
The growing interest in measuring economic and social phenomena that are difficult to observe directly increases the need for researchers to broaden the use of multivariate statistical analysis methods. The ease of interpreting results presented in the form of rankings makes it common practice to use different methods of linear ordering of objects. If the appropriate assumptions are met, the determined set of variables allows for the construction of a synthetic measure whose ordered values provide a ranking. Such a statistical approach is quite often used in assessing the level of innovativeness of economies, and the literature abounds in various innovation indices. The starting point of this paper is a set of 27 variables on the basis of which the Summary Innovation Index is developed. After verifying the statistical assumptions and reducing the database to 21 diagnostic factors, the authors construct a total of nine innovation rankings, using different methods of linear ordering and selected procedures for normalisation of variables. The aim of the paper is therefore to assess the impact of selected methods of linear ordering (Hellwig’s method, TOPSIS method, GDM method) and various procedures for normalising variables (classic standardisation, positional standardisation, quotient transformation) on the final ranking of the EU Member States due to the level of their innovation performance. The obtained results confirm that the applied method of linear ordering and the selection of the normalisation procedure have an impact on the final ranking of the examined objects – in this case, the final ranking of the EU Member States due to the level of their innovativeness analysed in the presented research
Analiza skupu wybranych produktów rolnych w Polsce w latach 2010-2016
Economic development is characterised by the fact that the share of agriculture tends to decrease both in terms of resources used and domestic product generated. This does not mean, however, that the role of agriculture in the economic development diminishes. It can be considered a paradox that the lower the share of agriculture in the national economy, the greater its role, as it provides raw materials for the production of goods, especially food, which meet the needs of the ever-growing community. The main aim of the presented study is to measure and evaluate changes in agricultural produce procurement in Poland in the years 2010-2016. The following research hypothesis is put forward in the study: Changes in the procurement volume had a much greater impact on the procurement value of selected agricultural produce in Poland in the period considered than changes in the level of transaction prices. In the paper, a comparative analysis of procurement of crop and animal products was conducted. The research process was based primarily on data derived from official statistics obtained from the Central Statistical Office and the Eurostat database regarding procurement of agricultural produce carried out by commercial entities and processing plants. This information is presented in qualitative and quantitative terms for total agriculture, as well as for individual voivodeships.Prawidłowością rozwoju gospodarczego jest to, że zmniejsza się udział rolnictwa zarówno w wykorzystanych zasobach, jak i w tworzonym produkcie narodowym. Nie oznacza to jednak, że zmniejsza się rola rolnictwa w rozwoju gospodarczym. Można uważać, za paradoks, że im mniejszy odsetek stanowi rolnictwo w gospodarce narodowej, tym większa jest jego rola, albowiem dostarcza ono surowców do wytwarzania dóbr, zwłaszcza żywnościowych, zaspokajających potrzeby coraz liczniejszej społeczności. Głównym celem niniejszego badania jest pomiar i ocena zmian skupu produktów rolnych w Polsce w latach 2010-2016.W niniejszym badaniu postawiono hipotezę badawczą: Zmiany w wolumenie skupu wywarły znacznie większy wpływ na wartość skupu wybranych produktów rolnych w Polsce w badanym okresie aniżeli zmiany w poziomie cen transakcyjnych. W artykule przeprowadzona została analiza porównawcza skupu towarów produkcji roślinnej oraz skupu towarów produkcji zwierzęcej Postępowanie badawcze oparto, przede wszystkim, na danych statystyki publicznej pozyskanych z Głównego Urzędu Statystycznego oraz bazy Eurostat z zakresu skupu produktów rolnych prowadzanego przez jednostki handlowe i przetwórcze. Informacje te prezentowane są w ujęciu ilościowym i wartościowym dla rolnictwa ogółem oraz dla województw
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