Antioxidative activity of Salvia Hispanica L.

Chia (Salvia hispanica L.) jednogodišnja je biljka poznata kao izvor sjemenki bogatih nutrijentima. U ovome radu ispitivan je utjecaj osvjetljavanja etioliranih klijanaca chije, tijekom 24 i 48 sata, na njihovu ukupnu antioksidativnu aktivnost, te na sadržaj ukupnih topljivih polifenola, askorbinske kiseline i koncentraciju karotenoida. Najveća koncentracija karotenoida izmjerena je nakon 48 sati osvjetljavanja, jednako kao i sadržaja askorbinske kiseline. Sadržaj ukupnih topljivih polifenola te ukupna antioksidativna aktivnost veći su u klijanaca izloženih svjetlosti u odnosu na etiolirane klijance, ali nema razlike između klijanaca izloženih svjetlu nakon 24 i 48 sati. Iz dobivenih rezultata možemo zaključiti da osvjetljavanje povoljno djeluje na ukupnu antioksidativnu aktivnost klijanaca, sadržaj ukupnih topljivih polifenola i askorbinske kiseline te koncentraciju karotenoida.Chia (Salvia Hispanica L.) is a one-year plant known as a source of nutrient-rich seeds. This thesis investigated the effect of illumination on etiolated seedlings during 24 and 48 hours. After treatment total antioxidant activity, total soluble polyphenols content, ascorbic acid content and carotenoid concentration was measured. The highest carotenoid concentration and ascorbic acid content were measured 48 hours after seedlings illumination. Total soluble polyphenols content and total antioxidant activity were higher in illuminated seedlings compared to etiolated, but there was no difference between seedlings exposed for 24 and 48 hours. From the obtained results we can conclude that illumination had beneficial effect on the total antioxidative activity, the content of total soluble polyphenols, ascorbic acid content and carotenoids concertation and in chia seedlings

Open Science. A Brief Introduction to the Movement and its Methodological Significance

Forum - metodološka bilješkaForum - methodological not

Open Science. A Brief Introduction to the Movement and its Methodological Significance

Forum - metodološka bilješkaForum - methodological not

Attraction Effect in the Visual Working Memory

Temeljno obilježje vidnoga radnog pamćenja jest da preciznost dosjećanja opada porastom broja podražaja koji se pamti. Ovaj se nalaz tumači kao posljedica raspodjele ograničene količine resursa, pri čemu porastom broja podražaja koji se pamti pada količina resursa pridana svakom podražaju. Nedavna istraživanja pokazuju kako dosjećanje u zadacima vidnoga radnog pamćenja ovisi i o karakteristikama seta podražaja koji se pamti. Konkretno, u zadatku pamćenja jednostavnih vidnih karakteristika dvaju podražaja (npr. orijentacije) dosjećanje jednog podražaja karakterizira sustavna pogreška u smjeru drugog zapamćenog podražaja, tzv. efekt privlačenja. U ovom smo istraživanju željeli provjeriti koliko je ovaj efekt otporan na eksperimentalne manipulacije preciznosti pamćenja podražaja. U četiri su eksperimenta sudionici (N = 33) pamtili i dosjećali se istovremeno prikazanih orijentacija podražaja. U prvom je eksperimentu redoslijed dosjećanja odabiran po slučaju; u drugom su eksperimentu sudionici trebali samostalno birati redoslijed kojim će se dosjećati, a u trećem i četvrtom eksperimentu redoslijed dosjećanja ponovno je odabiran po slučaju, no sudionicima je na svakoj sekvenci unaprijed (eksp. 3) ili unatrag (eksp. 4) signalizirano kojeg će se podražaja najvjerojatnije morati dosjetiti prvog. Efekt privlačenja bio je vidljiv u sva četiri eksperimenta, i to pri dosjećanju obaju podražaja. Ovo istraživanje demonstrira robusnost efekta privlačenja u vidnom radnom pamćenju, što implicira da mehanizmi u podlozi tog efekta nisu podložni korekciji, odnosno da su sastavni dio temeljnih procesa kodiranja vidnih podražaja.One of the basic characteristics of visual working memory (VWM) is that recall precision declines with the number of items to be memorised. This finding is interpreted as a consequence of the allocation of a limited pool of resources, whereby the amount of resources allocated to each item drops with each additional stimulus. Recent studies show that recall in VWM tasks also depends on the characteristics of the stimulus set which is to be memorised. Specifically, when memorising simple visual features of two stimuli (e.g. their orientations), the recall of one stimulus\u27s features is marked by a systematic bias towards the other stimulus\u27s features. In this study, we wanted to examine how robust this effect is to experimental manipulations of memory precision. In four experiments, participants (N = 33) memorised and recalled the orientations of two simultaneously presented stimuli. In the first experiment, the recall order was chosen at random. In the second, participants had to choose the recall order themselves. In the third and fourth experiments, recall order was again chosen at random, but participants were presented with a cue before (exp. 3) or after (exp. 4) the stimuli were displayed, which indicated which of the stimuli is most likely to be recalled first. The attraction effect was observed in all four experiments and affected the recall of both stimuli. This study demonstrates the robustness of the attraction effect in VWM, implying that the mechanisms underlying the effect are not susceptible to correction, or in other words, that it is a part of the fundamental processes of coding visual stimuli

A metabarcode based (species) inventory of the northern Adriatic phytoplankton

The northern Adriatic is characterised as the coldest and most productive marine area of the Mediterranean, which is due to high nutrient levels introduced by river discharges, the largest of which is the Italian Po River (at the same time also the largest freshwater input into the Mediterranean). The northern Adriatic is a very shallow marine ecosystem with ocean current patterns that result in long retention times of plankton in the area. The northern Adriatic phytoplankton biodiversity and abundance are well-studied, through many scientific and long-term monitoring reports. These datasets were based on phytoplankton morphological traits traditionally obtained with light microscopy. The most recent comprehensive eastern Adriatic phytoplankton checklist was published more than 20 years ago and is still valuable today. Since phytoplankton taxonomy and systematics are constantly being reviewed (partly also due to new molecular methods of species identification that complement classical methodologies), checklists need to be updated and complemented. Today, metabarcoding of molecular markers gains more and more importance in biodiversity research and monitoring. Here, we report the use of high throughput sequencing methods to re-examine taxonomic richness and provide updated knowledge of phytoplankton diversity in the eastern northern Adriatic to complement the standardised light microscopy method.This study aimed to report an up-to-date list of the phytoplankton taxonomic richness and phylogenetic relationships in the eastern northern Adriatic, based on sequence variability of barcoding genes resolved with advanced molecular tools, namely metabarcoding. Here, metabarcoding is used to complement standardised light microscopy to advance conventional monitoring and research of phytoplankton communities for the purpose of assessing biodiversity and the status of the marine environments. Monthly two-year net sampling targeted six phytoplankton groups including Bacillariophyceae (diatoms) and Chrysophyceae (golden algae) belonging to Ochrophyta, Dinophyceae (dinoflagellates), Cryptophyceae (cryptophytes), Haptophyta (mostly coccolithophorids) and Chlorophyta with Prasinophyceae (prasinophytes) and Chlorophyceae (protist green algae). Generated sequence data were taxonomically assigned and redistributed in two kingdoms, five classes, 32 orders, 49 families and 67 genera. The most diverse group were dinoflagellates, comprising of 34 found genera (48.3%), following by diatoms with 23 (35.4%) and coccolithophorids with three genera (4.0%). In terms of genetic diversity, results were a bit different: a great majority of sequences with one nucleotide tolerance (ASVs, Amplicon sequence variants) assigned to species or genus level were dinoflagellates (83.8%), 13.7% diatoms and 1.6% Chlorophyta, respectively. Although many taxa have not been detected that have been considered as common in this area, metabarcoding revealed five diatoms and 20 dinoflagellate genera that were not reported in previous checklists, along with a few species from other targeted groups that have been reported previously. We here describe the first comprehensive 18S metabarcode inventory for the northern Adriatic Sea

PHOTOSYNTHESIS IN TOBACCO (Nicotiana tabacum L.) LEAVES DEVELOPMENT

Duhan (Nicotiana tabacum L.) je gospodarski značajna kultura, a ujedno i često korišteni modelni organizam u biološkim istraživanjima. U ovom radu cilj je bio istražiti dinamiku razvoja fotosintetskog aparata tijekom ontogeneze listova duhana određivanjem koncentracija fotosintetskih pigmenata ključnih za apsorpciju svjetlosti (Chl a, Chl b) i mjerenjem fluorescencije klorofila a u svrhu procjene funkcionalnosti fotosintetskog aparata. Početna mjerenja izvršena su na listovima 14 dana starih presadnica, a sljedeća su obuhvatila pet insercija odnosno pet parova listova starosti 20, 24, 29, 32 i 37 dana. Rezultati su pokazali konstantni porast maksimalnog kvantnog prinosa fotosustava II (TR0/ABS) i indeksa fotosintetske učinkovitosti (PIABS) tijekom razvoja, potvrđujući kompetentnost ispitivanih skupina listova za učinkovito apsorbiranje i iskorištavanje energije u fotokemijskim procesima, unatoč različitoj dinamici akumulacije fotosintetskih pigmenata (Chl a, Chl b, Chl a+b). Porast gustoće aktivnih reakcijskih središta (RC/CS0) i smanjenje apsorpcije (ABS/RC) osigurali su porast učinkovitosti fotosustava II tijekom razvoja listova. Najviše koncentracije pigmenata izmjerene u insercijama 2 i 3 ukazuju na maksimum eksponencijalnog rasta listova u toj fazi razvoja. Degradacija pigmenata u insercijama 4 i 5 nije utjecala na funkcionalnost fotosintetskog aparata što je utvrđeno visokim vrijednostima parametara TR0/ABS i PIABS, ali ipak ukazuje na početak senescencije listova.Tobacco (Nicotiana tabacum L.) is one of the most economically important crops and also frequently used model organism in biological researches. The aim of this study was to investigate the dynamics of photosynthetic apparatus development during tobacco leaf ontogenesis. The concentration of photosynthetic pigments crucial for light absorption (Chl a, Chl b) as well as chlorophyll a fluorescence were measured to estimate functionality of photosynthetic apparatus. The measurements were performed on 14-day-old transplants and five insertions (leaf pairs) differing in developing stage (20, 24, 29, 32 and 37 days old). The results showed a constant increase of maximum quantum yield of photosystem II (TR0/ABS) and performance index (PIABS) during development, confirming the competence of all studied leaves for efficient utilization of absorbed energy in photochemical processes, despite the different pattern of pigments accumulation. Increasing density of active reaction centers (RC/CS0) and decreasing absorption (ABS/RC) provided a high photosystem II efficiency in developing leaves. The highest pigment concentrations measured in insertions 2 and 3 indicate that maximum exponential growth has been reached at this stage. The pigments degradation observed in insertions 4 and 5 did not affect the functionality of the photosynthetic apparatus, confirmed by the high values of TR0/ABS and PIABS, but nevertheless suggested the onset of leaf senescence

Antioxidative activity of Salvia Hispanica L.

Chia (Salvia hispanica L.) jednogodišnja je biljka poznata kao izvor sjemenki bogatih nutrijentima. U ovome radu ispitivan je utjecaj osvjetljavanja etioliranih klijanaca chije, tijekom 24 i 48 sata, na njihovu ukupnu antioksidativnu aktivnost, te na sadržaj ukupnih topljivih polifenola, askorbinske kiseline i koncentraciju karotenoida. Najveća koncentracija karotenoida izmjerena je nakon 48 sati osvjetljavanja, jednako kao i sadržaja askorbinske kiseline. Sadržaj ukupnih topljivih polifenola te ukupna antioksidativna aktivnost veći su u klijanaca izloženih svjetlosti u odnosu na etiolirane klijance, ali nema razlike između klijanaca izloženih svjetlu nakon 24 i 48 sati. Iz dobivenih rezultata možemo zaključiti da osvjetljavanje povoljno djeluje na ukupnu antioksidativnu aktivnost klijanaca, sadržaj ukupnih topljivih polifenola i askorbinske kiseline te koncentraciju karotenoida.Chia (Salvia Hispanica L.) is a one-year plant known as a source of nutrient-rich seeds. This thesis investigated the effect of illumination on etiolated seedlings during 24 and 48 hours. After treatment total antioxidant activity, total soluble polyphenols content, ascorbic acid content and carotenoid concentration was measured. The highest carotenoid concentration and ascorbic acid content were measured 48 hours after seedlings illumination. Total soluble polyphenols content and total antioxidant activity were higher in illuminated seedlings compared to etiolated, but there was no difference between seedlings exposed for 24 and 48 hours. From the obtained results we can conclude that illumination had beneficial effect on the total antioxidative activity, the content of total soluble polyphenols, ascorbic acid content and carotenoids concertation and in chia seedlings

PHOTOSYNTHESIS IN TOBACCO (Nicotiana tabacum L.) LEAVES DEVELOPMENT

Duhan (Nicotiana tabacum L.) je gospodarski značajna kultura, a ujedno i često korišteni modelni organizam u biološkim istraživanjima. U ovom radu cilj je bio istražiti dinamiku razvoja fotosintetskog aparata tijekom ontogeneze listova duhana određivanjem koncentracija fotosintetskih pigmenata ključnih za apsorpciju svjetlosti (Chl a, Chl b) i mjerenjem fluorescencije klorofila a u svrhu procjene funkcionalnosti fotosintetskog aparata. Početna mjerenja izvršena su na listovima 14 dana starih presadnica, a sljedeća su obuhvatila pet insercija odnosno pet parova listova starosti 20, 24, 29, 32 i 37 dana. Rezultati su pokazali konstantni porast maksimalnog kvantnog prinosa fotosustava II (TR0/ABS) i indeksa fotosintetske učinkovitosti (PIABS) tijekom razvoja, potvrđujući kompetentnost ispitivanih skupina listova za učinkovito apsorbiranje i iskorištavanje energije u fotokemijskim procesima, unatoč različitoj dinamici akumulacije fotosintetskih pigmenata (Chl a, Chl b, Chl a+b). Porast gustoće aktivnih reakcijskih središta (RC/CS0) i smanjenje apsorpcije (ABS/RC) osigurali su porast učinkovitosti fotosustava II tijekom razvoja listova. Najviše koncentracije pigmenata izmjerene u insercijama 2 i 3 ukazuju na maksimum eksponencijalnog rasta listova u toj fazi razvoja. Degradacija pigmenata u insercijama 4 i 5 nije utjecala na funkcionalnost fotosintetskog aparata što je utvrđeno visokim vrijednostima parametara TR0/ABS i PIABS, ali ipak ukazuje na početak senescencije listova.Tobacco (Nicotiana tabacum L.) is one of the most economically important crops and also frequently used model organism in biological researches. The aim of this study was to investigate the dynamics of photosynthetic apparatus development during tobacco leaf ontogenesis. The concentration of photosynthetic pigments crucial for light absorption (Chl a, Chl b) as well as chlorophyll a fluorescence were measured to estimate functionality of photosynthetic apparatus. The measurements were performed on 14-day-old transplants and five insertions (leaf pairs) differing in developing stage (20, 24, 29, 32 and 37 days old). The results showed a constant increase of maximum quantum yield of photosystem II (TR0/ABS) and performance index (PIABS) during development, confirming the competence of all studied leaves for efficient utilization of absorbed energy in photochemical processes, despite the different pattern of pigments accumulation. Increasing density of active reaction centers (RC/CS0) and decreasing absorption (ABS/RC) provided a high photosystem II efficiency in developing leaves. The highest pigment concentrations measured in insertions 2 and 3 indicate that maximum exponential growth has been reached at this stage. The pigments degradation observed in insertions 4 and 5 did not affect the functionality of the photosynthetic apparatus, confirmed by the high values of TR0/ABS and PIABS, but nevertheless suggested the onset of leaf senescence

Supplementary material 1 from: Grižančić L, Baričević A, Smodlaka Tanković M, Vlašiček I, Knjaz M, Podolšak I, Kogovšek T, Pfannkuchen MA, Marić Pfannkuchen D (2023) A metabarcode based (species) inventory of the northern Adriatic phytoplankton. Biodiversity Data Journal 11: e106947. https://doi.org/10.3897/BDJ.11.e106947

List of taxa retrived in this study, during 2 years monthly samplin