11 research outputs found
Monitoring zdravstvene ispravnosti vode za piÄe iz vodoopskrbnog sustava Grada Zagreba (Monitoring of Drinking Water Safety from the City of Zagreb Water Supply)
U radu su prikazani rezultati monitoringa zdravstvene ispravnosti vode za piÄe iz javnog vodoopskrbnog sustava grada Zagreba u razdoblju od 01.01.2005. do 01.09.2006. godine. Zdravstvena ispravnost vode za piÄe je od velikog javno-zdravstvenog interesa, pa je monitoring vode za piÄe potrebno provoditi u cjelosti i na nacionalnoj razini
PRC1ālabeled microtubule bundles and kinetochore pairs show oneātoāone association in metaphase
In the mitotic spindle, kinetochore microtubules form kāfibers, whereas overlap or interpolar microtubules form antiparallel arrays containing the crossālinker protein regulator of cytokinesis 1 (PRC1). We have recently shown that an overlap bundle, termed bridging fiber, links outermost sister kāfibers. However, the relationship between overlap bundles and kāfibers throughout the spindle remained unknown. Here, we show that in a metaphase spindle more than 90% of overlap bundles act as a bridge between sister kāfibers. We found that the number of PRC1āGFPālabeled bundles per spindle is nearly the same as the number of kinetochore pairs. Liveācell imaging revealed that kinetochore movement in the equatorial plane of the spindle is highly correlated with the movement of the coupled PRC1āGFPālabeled fiber, whereas the correlation with other fibers decreases with increasing distance. Analysis of endogenous PRC1 localization confirmed the results obtained with PRC1āGFP. PRC1 knockdown reduced the bridging fiber thickness and interkinetochore distance throughout the spindle, suggesting a function of PRC1 in bridging microtubule organization and force balance in the metaphase spindle
Rast i fotosinteza u vodene leÄe (Lemna minor L.) izložene kadmiju u kombinaciji s cinkom ili bakrom
Metals have a variety of negative outcomes on plants, essential components of any ecosystem. The effects of CdCl2 (5 Ī¼mol L-1), ZnCl2 (25 or 50 Ī¼mol L-1), and CuCl2 (2.5 or 5 Ī¼mol L-1) and combinations of CdCl2 with either ZnCl2 or CuCl2 on the growth, photosynthetic pigments, and photosystem II (PSII) efficiency of duckweed (Lemna minor L.) were investigated. All of the treatments caused growth inhibition and remarkable metal accumulation in plant tissue after 4 and 7 days. In the combined treatments, the accumulation of each metal applied was lesser in comparison to treatments with single metals. After 4 days, all of the treatments generally diminished chlorophyll a content and decreased the maximum quantum yield (Fv/Fm) and effective quantum yield (ĪF/Fām) of PSII. However, after 7 days of exposure to a combination of Cd and Zn, pigment content and PSII activity recovered to control levels. A higher concentration of Cu (5 Ī¼mol L-1) as well as Cd in combination with Cu had a prolonged inhibitory effect on photosynthetic features. Our results suggest that growth inhibition was due to the toxic effect of absolute metal quantity in plant tissue. Zn counteracted Cd uptake, as seen from the recovery of pigment content and PSII efficiency in plants exposed for 7 days to the Cd and Zn combination. Cu-induced oxidative stress led to a prolonged inhibitory effect in plants treated both with a higher concentration of Cu (5 Ī¼mol L-1) and simultaneously with Cd and Cu. Our findings could contribute to general knowledge on anthropogenic and environmental contaminants that endanger plant communities and significantly disrupt the sensitive balance of an ecosystem by influencing photosynthetic mechanisms.Izloženost metalima može izazvati razliÄite Å”tetne uÄinke u biljaka. Vodene leÄe izložili smo solima teÅ”kih metala CdCl2 (5 Ī¼mol L 1), ZnCl2 (25 Ī¼mol L 1 ili 50 Ī¼mol L 1) i CuCl2 (2,5 Ī¼mol L 1 ili 5 Ī¼mol L 1) te kombinaciji CdCl2 sa svakom od navedenih koncentracija ZnCl2 i CuCl2. Rast biljaka, koliÄina fotosintetskih pigmenata i uÄinkovitost fotosistema II (PSII) mjereni su nakon Äetiri i sedam dana tretmana. UtvrÄeno je da su svi tretmani uzrokovali znaÄajnu inhibiciju rasta te akumulaciju metala u biljci. U biljaka koje su bile izložene kombinacijama teÅ”kih metala koliÄina pojedinog metala u tkivu bila je niža u odnosu na koliÄinu istog metala u biljaka izloženih samo tom metalu. Nakon Äetiri dana tretmana sva su tri metala, neovisno o tome jesu li bila primijenjena zasebno ili u kombinacijama, uzrokovala smanjenje koliÄine klorofila a i pad vrijednosti maksimalnog (Fv/Fm) i efektivnog (ĪF/Fām) prinosa PSII. MeÄutim, u biljaka koje su bile istovremeno izlagane kadmiju i cinku, vrijednosti koliÄine pigmenata i uÄinkovitost PSII vratile su se nakon sedam dana na kontrolnu razinu, a bakar u koncentraciji 5 Ī¼mol L 1 te kombinacija kadmija i bakra i dalje su imali inhibitorni uÄinak. BuduÄi da smanjeno primanje pojedinog metala uoÄeno u biljaka izloženih kombiniranim tretmanima nije ublažilo inhibitorni uÄinak na rast, možemo zakljuÄiti da je inhibicija rasta uzrokovana apsolutnom koliÄinom metala primljenog u tkivo. PoveÄanje koliÄine fotosintetskih pigmenata i uÄinkovitosti PSII nakon sedam dana tretmana kadmijem i cinkom upuÄuje na oporavak biljaka, Å”to se može objasniti ublažavajuÄim djelovanjem cinka na uÄinak kadmija uslijed smanjenog primanja kadmija u biljku. Suprotno tome, dugotrajni inhibitorni uÄinak istovremenog tretmana biljaka kadmijem i bakrom te samim bakrom u koncentraciji 5 Ī¼mol L 1 može se objasniti oksidacijskim stresom uzrokovanim bakrom. Rezultati ovoga istraživanja pridonose saznanjima o Å”tetnim uÄincima antropogenih i okoliÅ”nih oneÄiÅ”ÄivaÄa, koji naruÅ”avanjem mehanizama fotosinteze ugrožavaju ne samo biljke i njihove zajednice nego i osjetljivu ravnotežu ekosustava
On the Zagreb Indices as Complexity Indices
Two original Zagreb indices, denoted M1 and M2, and introduced in 1972, were symmetry-modified by summing up only degrees (SMM1) or edge-weights (SMM2) of symmetry nonequivalent vertices or edges of graphs. Their dependence on the structural features and symmetry of molecular graphs is studied. They were also compared to eight other complexity indices (RCI, TC, TC1, BT, BI, twc, wcx) on nine graphs (A, B, C, D, E, F, G, H, I) with five vertices that were earlier studied by several research groups. The TC, TC1 and Nt produce exactly the same complexity ordering of nine graphs (I>H>G>F>E>D>C>B>A). The ordering produced by M1 is different from this ordering in that it cannot discriminate E and F, and C and D. Likewise, M2 and twc produce exactly the same ordering and the latter ordering differs from the former only in the reverse order of E and F. Orderings produced by SMM1 and SMM2 differ considerably from orderings given by TC, TC1 and Nt or M2 and twc
Occurrence of P. aeruginosa in Water Intended for Human Consumption and in Swimming Pool Water
Considering the fact that water is a basic need of every living being, it is important to ensure its safety. In this work, the data on the presence of the opportunistic pathogen P. aeruginosa in drinking water (n = 4171) as well as in pool water (n = 5059) in Primorje-Gorski Kotar County in Croatia in the five-year period (2016ā2020) were analysed. In addition, the national criteria were compared with those of neighboring countries and worldwide. The proportion of P. aerugino-sa- positive samples was similar for drinking water (3.9%) and pool water (4.6%). The prevalence of this bacterium was most pronounced in the warmer season. P. aeruginosa-positive drinking water samples were mostly collected during building commissioning, while pool samples were from entertainment and spa/hydromassage pools. Outdoor pools showed a higher percentage of positive samples than indoor pools, as well as the pools filled with freshwater rather than sea-water. The highest P. aeruginosa load was found in rehabilitation pools. Cro
UÄinak bakra na toksiÄnost i genotoksiÄnost kadmija u vodenoj leÄi (Lemna minor L.)
We investigated interactions between copper (in the concentrations of 2.5 Ī¼mol L-1 and 5 Ī¼mol L-1) and cadmium (5 Ī¼mol L-1) in common duckweed (Lemna minor L.) by exposing it to either metal or to their combinations for four or seven days. Their uptake increased with time, but it was lower in plants treated with combinations of metals than in plants treated with either metal given alone. In separate treatments, either metal increased malondialdehyde (MDA) level and catalase and peroxidase activity. Both induced DNA damage, but copper did it only after 7 days of treatment. On day 4, the combination of cadmium and 5 Ī¼mol L-1 copper additionally increased MDA as well as catalase and peroxidase activity. In contrast, on day 7, MDA dropped in plants treated with combinations of metals, and especially with 2.5 Ī¼mol L-1 copper plus cadmium. In these plants, catalase activity was higher than in copper treated plants. Peroxidase activity increased after treatment with cadmium and 2.5 Ī¼mol L-1 copper but decreased in plants treated with cadmium and 5 Ī¼mol L-1 copper. Compared to copper alone, combinations of metals enhanced DNA damage after 4 days of treatment but it dropped on day 7. In conclusion, either metal given alone was toxic/genotoxic and caused oxidative stress. On day 4 of combined treatment, the higher copper concentration was more toxic than either metal alone. In contrast, on day 7 of combined treatment, the lower copper concentration showed lower oxidative and DNA damage. These complex interactions can not be explained by simple antagonism and/or synergism. Further studies should go in that direction.U svrhu istraživanja interakcija izmeÄu bakra kao esencijalnog elementa te kadmija kao neesencijalnog i toksiÄnog metala, vodenu leÄu Lemna minor L. uzgajali smo na podlogama s kadmijem (5 Ī¼mol L-1) odnosno s bakrom (2,5 Ī¼mol L-1 i 5 Ī¼mol L-1) te s njihovim kombinacijama. Unos metala u biljke poveÄavao se s trajanjem pokusa, a kod kombinacije metala u biljkama je izmjerena niža koliÄina kadmija nego u onima uzgajanima samo na kadmiju. U biljkama tretiranim pojedinaÄnim metalom doÅ”lo je do poveÄanja
sadržaja malondialdehida (MDA) te aktivnosti katalaze i peroksidaze u odnosu na kontrolne biljke. TakoÄer, primijeÄeno je oÅ”teÄenje DNA iako kod bakra tek sedmog dana tretmana. KoliÄina MDA i aktivnost obaju enzima dodatno se poveÄala na tretmanu kombinacijom kadmija i bakra (5 Ī¼mol L-1) nakon Äetvrtog dana pokusa, dok se koliÄina MDA smanjila nakon sedmog dana kod kombinacije kadmija i 2,5 Ī¼mol L-1 bakra. U tim biljkama primijeÄena je i veÄa aktivnost katalaze, dok je aktivnost peroksidaze porasla na tretmanu kadmijem i 2,5 Ī¼mol L-1 bakrom, ali se smanjila na tretmanu kadmijem i 5 Ī¼mol L-1 bakrom. OÅ”teÄenje DNA koje je bilo veÄe kod kombinacije metala nakon Äetvrtog dana, osobito u usporedbi sa samim bakrom, smanjilo se nakon sedmog dana pokusa. Iz ovih rezultata može se zakljuÄiti da su oba metala u istraživanim koncentracijama toksiÄna i genotoksiÄna za vodenu leÄu i da uzrokuju oksidacijski stres. Kadmij u kombinaciji s bakrom viÅ”e koncentracije bio je toksiÄniji od pojedinaÄnih metala nakon
Äetvrtog dana pokusa, dok su u biljaka tretiranih kombinacijom kadmija i bakra niže koncentracije toksiÄni uÄinci bili manji. BuduÄi da su primijeÄene interakcije vrlo kompleksne i ne ukljuÄuju samo antagonizam odnosno sinergizam potrebna su daljnja istraživanja