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The impact of temperature and photosynthetically active radiation on the growth and pigments concentration in Baltic picocyanobacterium Synechococcus sp.

100%

Śliwińska-Wilczewska S., Cieszyńska A., Latała A.

Annales Universitatis Paedagogicae Cracoviensis Studia Naturae

2017

The experiments on three Baltic picocyanobacterial strains of Synechococcus (BA-120 – red strain, BA-124 – green strain and BA-132 – brown strain) were conducted at four scalar irradiances in Photosynthetically Active Radiation (PAR) and four temperature levels. The main aim of this work was to estimate the effect of environmental conditions (temperature and PAR) on cell concentration and photosynthetic pigments (Chlorophyll a – Chl a and Carotenoids – Car) contents. The ranges of PAR and temperatures were 10, 100, 190, 280 μmol m-2 s-1 and 10, 15, 20, 25ºC, respectively. The experiment was carried in a medium of salinity of 8. The number of Synechococcus sp. cells was determined using a BD Accuri™ C6 flow cytometer. The pigments contents were determined by a spectrophotometric method. In this work, it was found that elevated intensity and temperature have, on average, a positive effect on cell concentration for Synechococcus sp. The highest cells concentrations were noted at the highest PAR (280 µmol m-2 s-1) and the highest T (25ºC) for green and brown strains (BA-124 and BA-132, respectively) and at 190 µmol m-2 s-1 and 25ºC for red strain (BA-120). Comparing the strains at each PAR level and temperature, the highest cell concentration was noted in green strain (36·106 cell ml-1), while the lowest was observed in red strain (8·106 cell ml-1). In general, in the two strains of Synechococcus (BA-120 and BA-132), the highest Car and Chl a contents were observed at the lowest light intensity and the highest temperature. On the other hand, Car and Chl a maximum content in BA-124 were noted at the lowest light and temperature. The experiments on Synechococcus strains demonstrated their high capacity to acclimate to a wide range of PAR and temperature levels. The three strains of Synechococcus showed adaptation capabilities, since they were able to change the composition of their photosynthetic pigments to use light quantity better and to protect the cells from the unfavourable effect of elevated light and temperature.

Badania partycypacyjne w działaniu (PAR): między produkcją wiedzy a społecznym zaangażowaniem

99%

Brzozowska-Brywczyńska M.

Rozwój Regionalny i Polityka Regionalna

2019

issue 46

91-101

The article aims to present the general principles of conducting participatory action research. It outlines the twofold history of PAR, resulting in two distinct philosophies and research practices. I discuss the specificity of PAR research process and the nature of relations between researcher and research participants. I also address the paradigmatic non-obviousness of PAR that leads to a series of significant methodological and ethical dilemmas. Most importantly, they stem from the plethora of names used to describe the method and – consequently – to define its purpose and form, especially when it comes to the role of participation. The importance of participation in PAR and its influence on the research practice are discussed in the final part of the article, offering – alongside description of the title method – a pretext for a further discussion on conditions and consequences of its implementation.

Artykuł ma na celu przybliżenie ogólnych zasad prowadzenia partycypacyjnych badań w działaniu, przywołując ich dwutorową historię oraz wynikającą z niej filozofię i praktykę badawczą. Opisuję w nim specyfikę procesu badawczego oraz relacji między badaczem i uczestnikami badań. Jednocześnie moja prezentacja opiera się na założeniu o paradygmatycznej nieoczywistości PAR, która wikła je w szereg istotnych dylematów etycznych i metodologicznych. Związane są one przede wszystkim z przyjmowaniem przez badaczy różnych definicji, a co za tym idzie – celu i formy – partycypacji uczestników badań w działaniu. Znaczenie partycypacji w PAR i jej konsekwencje dla praktyki badawczej są przedmiotem dyskusji końcowej części artykułu, oferując czytelnikowi obok opisu metody, również pretekst do namysłu nad warunkami i konsekwencjami jej stosowania.

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1 Annales Universitatis Paedagogicae Cracoviensis Studia Naturae

1 Rozwój Regionalny i Polityka Regionalna

1 Brzozowska-Brywczyńska M.

1 Cieszyńska A.

1 Latała A.

1 Śliwińska-Wilczewska S.

1 2019

1 2017

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The impact of temperature and photosynthetically active radiation on the growth and pigments concentration in Baltic picocyanobacterium Synechococcus sp.

Badania partycypacyjne w działaniu (PAR): między produkcją wiedzy a społecznym zaangażowaniem