Wyniki wyszukiwania - Biblioteka Nauki

1

Spanning Trees whose Stems have a Bounded Number of Branch Vertices

100%

Yan Z.

Discussiones Mathematicae Graph Theory

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2016

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tom 36

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nr 3

773-778

EN

Let T be a tree, a vertex of degree one and a vertex of degree at least three is called a leaf and a branch vertex, respectively. The set of leaves of T is denoted by Leaf(T). The subtree T − Leaf(T) of T is called the stem of T and denoted by Stem(T). In this paper, we give two sufficient conditions for a connected graph to have a spanning tree whose stem has a bounded number of branch vertices, and these conditions are best possible.

2

Is Entering STEM Socially Contagious? Contextual Factors in Women’s Educational Decisions

100%

Zawistowska A.

Polish Sociological Review

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2017

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tom 197

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nr 1

51-66

EN

Despite the nonexistence of institutional obstacles, majors in science and mathematics continuously attract women to a greater extent than those in technology and engineering. Based on a series of in-depth interviews conducted with students of various STEM majors in an university and a polytechnic in the same city in Poland, this paper attempts to explore the reasons for this divergence. Analysis of the detailed biographical narrations reveals that the women’s choice of male-dominated majors coincides with the presence of a significant role model (SRM) in the close social network. An SRM is an individual who is more experienced in a given domain and who has personal, lasting, and emotional contact with the decision-maker. The presence of an SRM was observed most often among female students of polytechnic, and was hardly observable among their university counterparts. The SRM provided various forms of support and information, and debunked discouraging stereotypes of maledominated majors. Furthermore, a long-lasting relationship with the SRM led to the development of a strong preference for polytechnics over universities. Those findings fit well with the explanations provided by the theory of social contagion.

3

Cyperus canus J.Presl & C.Presl – A traditional source of fiber, its uses, products and cultural significances among ethnic communities of Central America

100%

Mó E. , Cetzal-Ix W. , Noguera-Savelli E. , Basu S. K. , Zandi P. , Możdżeń K.

Annales Universitatis Paedagogicae Cracoviensis Studia Naturae

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2016

EN

Rodzaj Cyperus L. (Cyperaceae) obejmuje od 750 do 950 gatunków. Występuje w ścisłym powiązaniu z ekologicznymi ugrupowaniami różnych gatunków traw. Gatunki z rodzaju Cyperus posiadają rozmieszczenie kosmopolityczne. Niektóre z nich są uważane za szkodliwe chwasty uprawowe. Jednak duża ich liczba znalazła zastosowanie w rolnictwie, ogrodnictwie oraz w przemyśle farmaceutycznym. Cyperus canus J.Presl & C.Presl (Cyperaceae) jest rośliną naturalną dla tropikalnej Ameryki i rozmieszczony jest od południowego Meksyku oraz Gwatemali do Kolumbii. Gatunek ten występuje wzdłuż brzegów jezior, strumieni i bagien, a czasami na skałach, na wysokości 200-1500 m n.p.m. W naturalnym środowisku jest rośliną dość rzadko spotykaną, ponieważ traktowany jest jako pospolity chwast. W Ameryce Środkowej, C. canus jest rośliną powszechnie stosowaną do produkcji dywanów, nosidełek dla dzieci, portfeli, teczek, kapeluszy i lin. W Gwatemali, pędy tego gatunku są używane do wyplatania koszy i torebek, do produktów codziennego użytku (śpiworów, sandałów, wachlarzy) oraz przygotowywania tradycyjnych potraw. W artykule tym opisano zastosowanie i procesy produkcji niektórych ważnych wyrobów wykonywanych z dzikorosnącego C. canus.

4

Investigations on tensile load-carrying ability of reed stems

100%

Kowalski W.

Acta Scientiarum Polonorum. Architectura

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2016

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tom 15

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nr 4

EN

The investigations on mechanical properties of reed stems face numerous difficulties, because of their anisotropy, heterogeneity, shell-like structure, small lateral dimensions of stems and huge diversity of species and habitats of origination. Aware of all difficulties to cope with, the basic experiment has been conducted, that is the uni-axial tension test for reed stems, with- and without joints. The strain-stress relation, at tension, displayed an exponential character, showing material stiffening with the growth of strain. Test results incline to conclusion, that stem-pieces without joints are equally stiff as pieces with joints, however, they are twice as strong as the latter. It means, that joints can be perceived as fragile (in the sense: “brittle”) discontinuity in structure of reed stems. The results of the test have been put through critical estimate and analysis tending to statistical modelling of the load-carrying ability of reed stems.

PL

Badania wytrzymałościowe trzciny napotykają szereg trudności z powodu powłokowej struktury łodyg, ich anizotropii, niejednorodności, małych wymiarów przekroju oraz dużych rozrzutów w wynikach z powodu specyficzności użytych próbek. Mając świadomość wszystkich tych trudności, w niniejszej pracy przedstawiono wyniki prostego eksperymentu, polegającego na osiowym rozciąganiu próbek łodyg trzciny z kolankami i bez. Związek między odkształceniem a naprężeniem w czasie testu przybierał charakter wykładniczy, co wskazuje na tendencję do usztywniania się łodyg wraz ze wzrostem odkształceń. Wyniki testu skłaniają do wniosku, że części łodygi bez kolanek są tak samo sztywne jak z kolankami, są jednak dwukrotnie od nich wytrzymalsze. Prawdziwość takiego wniosku oznaczałaby, że kolanka stanowią niepodatne, kruche osłabienie łodyg. Wyniki przeprowadzonego testu poddano krytycznej ocenie, a przeprowadzone dodatkowe analizy pozwoliły na budowę prostego modelu probabilistycznego dla przeprowadzonego eksperymentu.

5

Fungi colonizing potato stem bases depending on the method of nitrogen fertilization

100%

Czajka W. , Cwalina-Ambroziak B. , Brzozowska I. , Ciecko Z. , Zolnowski A.

Polish Journal of Natural Sciences

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2002

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tom 12

6

Optical properties of stems and leaves of apple trees

100%

Tokarz K. , Pilarski J.

Polish Journal of Natural Sciences. Supplement

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2003

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tom 01

7

Research of parameters of cutting the stems of giant miscanthus on the resistance force

88%

Nowakowski T. , Wrobel K.

Annals of Warsaw University of Life Sciences - SGGW. Agriculture

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2015

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nr 65 Agric.Forest Eng.

8

Methyl jasmonate induces the formation of secondary abscission zone in stem of Bryophyllum calycinum Salisb.

88%

Saniewski M. , Ueda J. , Miyamoto K.

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tom 22

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nr 1

9

Extreme conditions for proceeding photosynthesis in stem of herbaceous plants

75%

Kocurek M. , Pilarski J.

Acta Physiologiae Plantarum

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2007

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tom 29

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nr 1 Suppl.

10

XRF analysis of Pongamia pinnata stem of semi arid region of Kachchh

75%

Ram V. R. , Patel M. G. , Ram P. N. , Khatri T. T. , Dave P. N.

International Letters of Natural Sciences

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2015

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tom 40

EN

The objective of the present investigation was to study the chemical composition of stem of Pongamia pinnata is a species of tree native to India growing in semi-arid region of Kachchh district, Gujarat, India. The stem of Pongamia pinnata were subjected to Energy Dispersive X-ray Fluorescence (EDXRF) and were analyzed for different mineral composition. As the X-ray Fluorescence is one of the most reliable and accurate, as well as it is also a consistent and nondestructive method for analysis of major and trace elements using a single pressed pellet. During the study it was found that Potassium, Chloride, Calcium, Silicon, Sulfur, Aluminum, Phosphorus were noted in higher amounts, compared to that of other elements like Manganese, Iron, Nickel, Copper, Zink, Bromide, Rubidium, Strontium, Stannous, whereas the elements which were not detected in stem of Pongamia pinnata are Titanium, Cobalt, Hafnium and Tantalum.

11

The Changing Stereotypes in Popular Films Stem Themed: On Breaking the Traditional Rigid Values and the Popularisation of Science

75%

Gürkan H. , Echazarreta-Soler C. M.

Communication Today

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2023

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tom 14

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nr 1

192-207

EN

This study analyses STEM identities in STEM fields represented in popular films. The authors argue that the recently produced big-budget popular films directly or indirectly affirm STEM characters with their portrayal of STEM fields. This analysis focuses on how popular narratives can be an essential tool to communicate the idea that women can be scientists and how they can inspire young women to enter science. These narratives reflect a significant problem in the interactions between the audience and science. The audience thinks the scientists are heroes and the public expect that scientists will automatically accept scientific solutions to problems. Nevertheless, scientists find a solution in these films, and everything gets better. Thus, recent popular STEMthemed big-budget films provide identification with the audience and STEM characters. These narratives construct an alternative STEM discourse by breaking down gender stereotypes and dominant ideology. These films can be coded as films that produce ideology against the dominant ideology and patriarchy, especially regarding STEM, character and gender representation. There is a positive change in the hierarchical order in the STEM field and the representation of women and Others. And these representations do not have any marginalisation.

12

Photosynthetic activity of leaves, pods and stem internodes of field bean (Vicia faba L. var. minor) in various phases of pods development

75%

Koscielniak J. , Filek W. , Skoczkowski A.

Bulletin of the Polish Academy of Sciences. Biological Sciences

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1988

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tom 36

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nr 10-12

13

High-frequency adventitious shoot organogenesis from in vitro stem explants of Scutellaria araxensis Grossh

75%

Gharari Z. , Bagheri K. , Sharari A.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2022

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tom 103

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nr 2

14

Effect of epibrassinosteroids and auxin on the stem growth and ethylene production in tulips

75%

Wegrzynowicz-Lesiak E. , Saniewski M.

Acta Physiologiae Plantarum

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2007

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tom 29

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nr 1 Suppl.

15

Chemical control of rhododendron twig blight caused by Phytophthora Ramorum

75%

Orlikowski L. B.

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16

The use of paclobutrazol, an inhibitor of gibberellin biosynthesis, for study of hormonal control of tulip stem elongation

75%

Saniewski M.

Bulletin of the Polish Academy of Sciences. Biological Sciences

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1989

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tom 37

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nr 1-3

17

Quantification of bovine mammary stem/progenitor cells by laser scanning and flow cytometry

75%

Osinska E. , Gajewska M. , Majewska A. , Motyl T.

Animal Science Papers and Reports

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2015

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tom 33

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nr 1

EN

Due to the presence and activity of mammary stem cells (MaSC), growth and remodelling of mammary gland during puberty and lactation cycles is possible. In this study the number of putative mammary stem/progenitor cells was examined in 20 months old non-pregnant Holstein-Friesian heifers. Cells were double-stained with fluorescent dye-conjugated antibodies against stem cell antigen-1 (Sca-1) and fibronectin type III domain containing 3B (FNDC3B), and were analysed Rusing scanning cytometry and flow cytometry. Nuclei were counterstained with Hoechst 33342. Scanning and flow cytometry revealed 2.43±0.32% and 1±0.37% of MaSC in total cell number, respectively.Sca-1posFNDC3Bpos cells did not express estrogen receptor (ERα), confirming their undifferentiated phenotype. In conclusion, scanning cytometry is a preferable method for evaluation of the number and localization of MaSC in situ, whereas, flow cytometry with cell sorting enables further genomic and biochemical analyses of isolated cells.

18

The androgenic response in anther culture of spring wheat is greater in genotypes with solid stem in contrast to genotypes with hollow stem

75%

Weigt D. , Kiel A. , Nawracala J. , Pluta M.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2015

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tom 96

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nr 1

19

Biodiversity of fungi inhabiting the highbush blueberry stems

75%

Szmagara M.

Acta Scientiarum Polonorum. Hortorum Cultus

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2009

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tom 08

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nr 1

EN

The aim of the work was to examine the health status of 11 highbush blueberry (Vaccinium corymbosum L.) cultivars cropped on the plantations in a south-eastern region of Poland as well as to determine the composition of fungus species colonizing their stems. The performed observations of health status indicated that stems with disease symptoms were found on almost all bushes. Three types of symptoms were found: spots on stems, from which mainly Topospora myrtilli was isolated, widespread stem necrosis inhabited by Phomopsis archeri and necrosis of stem tops caused by Botrytis cinerea. Moreover, the following isolates of fungi were obtained Cytospora, Phoma, Fusarium, Alternaria and Seimatosporium vaccinii, Myxothyrium leptideum and Sordaria fimicola. It was confirmed that the most malignant pathogen of highbush blueberry in the studied region was Topospora myrtilli.

PL

Celem pracy było określenie zdrowotności 11 odmian borówki wysokiej (Vaccinium corymbosum L.) uprawianych na plantacjach w południowo-wschodnim regionie Polski, jak również wyznaczenie składu gatunkowego grzybów kolonizujących ich pędy. Przeprowadzone obserwacje zdrowotności wskazały, że pędy z objawami chorobowymi były odnajdywane niemal we wszystkich krzewach. Wyróżniono trzy rodzaje objawów: plamy zgorzelowe, z których izolowano głównie Topospora myrtilli, rozległe plamy nekrotyczne zasiedlane głównie przez Phomopsis archeri oraz nekrozę wierzchołków pędów powodowaną przez Botrytis cinerea. Ponadto uzyskano izolaty następujących grzybów: Cytospora, Phoma, Fusarium, Alternaria oraz Seimatosporium vaccinii, Myxothyrium leptideum i Sordaria fimicola. Stwierdzono, że najgroźniejszym patogenem borówki wysokiej w badanym regionie był Topospora myrtilli.

20

Morphological Effects of Stymjod Foliar Application on Medicago × varia T. Martyn

75%

Sosnowski J. , Toczyska E. , Truba M.

Journal of Ecological Engineering

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2019

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tom Vol. 20, nr 8

184--191

EN

The aim of the study was to investigate how the foliar application of iodine, as well as its concentration in the working liquid, influence the growth of fresh and dry weight of plants, stems, leaves, roots and number of shoots and leaf laminae of sand Lucerne. The experiment was carried out in vases. The three plants that developed the largest number of leaves in the vase were left. The experimental factors as the plant growth regulator with the trade name Stymjod in three concentrations of 1.5%, 3% and 4.5% in the working liquid were introduced; the control involved distilled water. Two plant applications were performed. The first one in 6 appropriate leaf phase and the second in the branching formation phase. A single dose of the working liquid was 50 ml per vase. This dose of liquid caused the complete sprinkling of plants in a vase. The obtained results were statistically analyzed by means of analysis of variance. The experiment showed that the concentration of Stymjod in the working liquid is very important. It is difficult to say which concentrations gave the best results in cultivating sand lucerne. The present studies demonstrated that Stymjod applied foliarly at 4.5% concentration significantly affected the growth of stems and leaf blades. Additionally, 1.5% concentration increased the weight of fresh matter and dry matter of roots. The experiment showed that the effects of Stymjod application to hybrid alfalfa depended on its dose. It is difficult, however, to clearly state which concentration produced the best results so further research in this area is needed.