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Ovo je priča o ledenom čovjeku nazvanom Ötzi, starom 5300 godina. Čini se kao najsuvremenija detektivska priča s nevjerojatnim zapletima i otkrićima. To je najstarija i najbolje očuvana smrznuta prirodna mumija ikad nađena. Pruža nam zapanjujući uvid u svijet prije našeg doba. Otkriva nam kako je živio, što je jeo i kako je završio svoj život. Postavlja nam mnoga pitanja, stavlja nas u nedoumice i navodi nas na preispitivanje dosadašnjih znanja o tom davnom dobu. Krenimo na putovanje u prošlost i zavirimo u jedan sasvim poseban život.

Praćen je učinak norflurazona na zelenu hidru (Hydra viridissima Pallas, 1766), smeđu hidru (Hydra oligactis Pallas, 1766) i zelenu algu Chlorella kessleri Fott i Novak. [K&H, 1992]. Norflurazon je selektivni translokacijski herbicid s izbljeđujućim učinkom na novonastale kloroplaste pri čemu se smanjuje fotosintetska aktivnost i vijabilnost organizma. Zelena hidra je tipičan primjer endosimbioze jer u svojim gastrodermalnim mioepitelnim stanicama sadrži zelene alge vrste Chlorella vulgaris Beij. [K&H, 1992]. Dobiveni rezultati uspoređivani su sa spomenutim, evolucijski srodnim, organizmima izvan simbioze - smeđom hidrom te algom klorelom. U ekotoksikološkom istraživanju, to je prvi primjer serije test-organizama, koji dijele spomenute složene evolucijsko-simbiotske odnose. Organizmi su tretirani na jakom i difuznom svjetlu 21 dan s pet koncentracija vodene otopine norflurazona (2x10-4, 2x10-5, 2x10-6, 2x10-7 i 2x10-8 mol/L) u laboratorijskim uvjetima. Ovisno o koncentraciji i svjetlosnim uvjetima, norflurazon je izazvao smrtnost, značajne morfološke, citološke, histološke i ultrastrukturne promjene, promjene u ponašanju, lokomociji i nespolnom razmnožavanju na svim test-organizmima, te smanjenu fotosintetsku aktivnost algi. U niskim koncentracijama norflurazona uočena je sličnost s kontrolom te hormestički učinak na rast algi. Od posebnog značaja bio je antikloroplastni te antimitohondrijski učinak, kao i oštećenja animalnih organizama istraživanim herbicidom. Novonastali pupovi u simbiotskoj zelenoj hidri nisu bili izblijeđeni, dok je efekt izbljeđivanja bio prisutan u algi izvan simbioze. Norflurazon se pokazao kao potencijalni opasni ksenobiotik/onečistač okoliša, s deletirajućim učinkom na sve istraživane organizme i gotovo sve njihove strukture. Kao krajnji rezultat narušene simbioze hidre i alge, pokazala se ponovna uspostava endosimbioze kod pojedinih preživjelih jedinki te njihov djelomični ili potpuni oporavak. Rezultati ovih istraživanja doprinose razrješavanju i pojašnjavanju složene problematike simbioze, a uvodi se i metoda nazvana Chlorella test.

The original formulation of Zagreb indices (M1 and M2) is presented and their properties are discussed. Their variants: modified ZG indices (mM1 and mM2), ZG complexity indices (TM1, TM1*, TM2 and TM2*) and the modified ZG complexity indices (mTM1, mTM1*, mTM2 and mTM2*) are presented. The modified ZG complexity indices were derived combining ideas of Bonchev1 about calculating indices for all connected subgraphs s of a graph and summing them up and using as indices the modified Zagreb indices: mTM1 =     [1/di2 (s)] (1) s vertices mTM2 =     [1/di dj(s)] (2) s edges The first sum in the above formulas represents the sum over all connected subgraphs s of a graph G. In (1), the mM1 index is calculated for each subgraph s using the vertex-degrees as they are in the graph G. If the mM1 index is calculated for each subgraph s using the vertex-degrees as they are in the isolated subgraphs, then the corresponding index is mTM1*. In the case of the mTM2 index (eq. 2), the mM2 index is calculated for each subgraph s using the edge-weights as they are in the graph G. If the mM2 index is calculated for each subgraph s using the edge-weigths as they are in the isolated subgraphs, then the corresponding index is mTM2*. The use of mTM1, mTM1*, mTM2 and mTM2* indices as complexity indices is illustrated on several classes (n-alkanes, cycloalkanes, branched acyclics, polycyclic hydrocarbons) of molecules. The use of the whole family of ZG complexitx indices in the QSPR is illustrated by modeling several properties of C3-C8 alkanes using our CROMRsel procedure. The obtained models are compared to the corresponding models in the literature.

Bratislava-grad vode

Proučavajući početke umjetnosti u vrste Homo sapiens, saznajemo kako je doživljavao prirodu i promjene oko sebe te kakvo je bilo njegovo poimanje svijeta. Još i danas postoje kulture čija je umjetnost na razini paleolitskog čovjeka. Proučavajući te kulture saznajemo o našoj dalekoj prošlosti.

CHLOROPLASTAL DAMAGE AS TRIGGER TO HYDRA-ALGA ENDOSYMBIOSIS BREAKDOWN G. KOVACEVIC(1), N. LJUBESIC(2), M. KALAFATIC(1) (1)Faculty of Science, University of Zagreb, Department of Zoology, HR-10000 Zagreb, Croatia, (2) Ruder Boskovic Institute, Department of Molecular Genetics, Bijenicka 54, HR-10000 Zagreb, Croatia The deleterious effect of herbicide SAN 9789 on hydra-alga endosymbiosis was studied. The aim of this study was to observe the changes on chloroplast in endosymbiotic green alga and on other ultrastructural components in both endosymbionts, and from this point of view to draw out the conclusion about (in)dependence of both endosymbionts and maintaining of the endosymbiosis. Green hydra (Hydra viridissima Pallas, 1776) is an excellent example of endosymbiosis. In its gastrodermal myoepithelial cells it contains the individuals of unicellular green alga Chlorella vulgaris(1). Endosymbiosis is possible because of the specific preadaptations of both endosymbiont and its host. Green alga contains the characteristic huge kidney-like chloroplast with dense thylakoides that form numerous grana. Chloroplast envelopes contain carotenoids that have protective photooxidative role. Individuals of green hydra were treated in high-light (1372 lx) and low-light (294 lx) laboratory conditions (21oC, 10 hs daylight and 14 hs dark) for 72 hs with 2x10-4 mol/L and 2x10-5 mol/L of water solution of herbicide SAN 9789, active compound norflurazon, using aquarium water. They were compared to control groups of organisms. For cTEM standard preparation methods were used. Micrographs were made by using electron microscope Zeiss EM10A. The expected antichloroplastal effect was the most expressed since norflurazon is a bleaching agent that affects carotenoids especially in high-light conditions(2). The ultrastructural analysis of high-light conditions treatment in higher concentration showed irregularities to chloroplastal thylakoidal system that was changed in shape and position, with thylakoides thorn apart, ending with blind ends. Changes were observed also on other ultrastructures of green alga and hydra. Algal hard cell wall was wrinkled. Absence of symbiosomes and changed volume of perialgal space pointed out the extreme damages. Mitochondria were affected. Endoplasmic reticulum was torn apart, found only in fragments. Different kinds of membrane structures were formed in the shape of osmiophylic figures as the result of complete animal cell degradation, while white globules and dark spots appeared in algal vacuoles. Inside chloroplast plastoglobules appeared (Fig. 1). This is known response to the xenobiotic treatment(3). In concentration 2x10-5 mol/L occurred similar changes but of weaker intensity (Fig. 2). Described but milder damages occurred also in low-light conditions treatment.

Kompjuterska paleoantropologija

Predreaction complexes, transition states and adducts were characterized with MP2/6-31+G(d, p) and B3LYP/6-31G(d, p) methods. Reaction rate were calculated using transition state theory.

Prvi Europljani

Proučavajući početke umjetnosti u vrste Homo sapiens, saznajemo kako je doživljavao prirodu i promjene oko sebe te kakvo je bilo njegovo poimanje svijeta. Još i danas postoje kulture čija je umjetnost na razini paleolitskog čovjeka. Proučavajući te kulture, saznajemo o našoj dalekoj prošlosti.

Background and purpose: The main aim of this study was to determine the effect of low doses of insecticide diflubenzurone on the Dugesia tigrina (Gir.) species in laboratory conditions. Materials and methods: Individuals of planarian Dugesia tigrina (Gir.) were treated with 0.02 % and 0.01 % water solution of insecticide diflubenzurone for 24 hours. Mortality and behavioral, morphological, cytological and histological changes were monitored, as well as regeneration and the course of recovery. Morphological changes and behaviour were monitored daily by means of stereomicroscope. For cytological and histological analysis, on the 1st, 2nd, 3rd, 6th and 11th day after the treatment two extremely damaged animals from each concentration were fixed, embedded into paraplast, cut, stained and immerse into Canada balsam. Results: Treatment with water solution of diflubenzurone resulted with mortality in the higher concentration. It also caused behavioural changes and extreme morphological, histological and histological damages. Anterior parts of planarian body were extremely damaged, but recovered successfully. In this part of the body greater amount of neoblasts and nerve tissue was present. After regenerative processes on the posterior part of the body certain lower number of permanent deformations was remarked. Less damaged planarians regenerated after the short period of time, but strongly damaged animals needed longer period for recovery. It took nine days for the complete regeneration of the damaged body parts. Conclusions: Used concentrations of diflubenzurone caused mortality, behavioral changes, as well as cytological and histolgical changes in treated planarians. Reticular cells and neoblasts take part in the formation of regeneration blastema. Results showed that the anterior parts of planarian body were more sensitive to diflubenzurone treatment than the posterior, but anterior parts regenerated faster and more successfully. After the regenerative processes, small amount of permanent deformations on the posterior parts of the body was established.

Reaction minima and transition states, concerning proton transfer in acetylacetone were determined using Möller-Plesset ab initio and B1LYP density functional theory calculations. It is found that minima and the transition state for proton transfer have different methyl groups orientation. Intrinsic reaction path calculation has shown that the rotation of the methyl groups is not concerted with the proton transfer reaction, rather they are consecutive processes. The thermodynamical stability of the keto and enol forms of acetylacetone is explored by using G2 type calculations and it is shown to be in good agreement with experimental results. The position and shape of the OH stretching band in acetylacetone have been calculated using Density Functional Theory with the B1LYP functional. Our analysis reveals strong anharmonic coupling between four vibrational modes; the OH stretching, two OH bending (in plane and out-of plane), and the H-bond stretching mode. Accurate vibrational calculations in the resulting four-dimensional normal coordinate subspace are presented.

The toxic effect of antibiotic cinoxacin on endosymbiotic green alga (Chlorella vulgaris) from green hydra (Hydra viridissima Pallas) was studied. It is known that some antibiotics have antichloroplastal and antimitochondrial effect on Euglena and green hydra1, 4, what points out the connection of chloroplasts and mitochondria with eubacteria2. The individuals of unicellular green algae are placed in gastrodermal myoepithellial cells of green hydra as endosymbionts, at most 20 algae in one gastrodermal myoepithellial cell (Fig. 1). Endosymbiosis is possible because of specific preadaptations of both endosymbiont and its host. Green algae contain the characteristic huge kidney-like chloroplast with dense thylakoides that form numerous grana. This organelle is, as well as mitochondria, sensitive to antibiotic treatment. Individuals of green hydra were treated for 72 hs in glass dishes under laboratory conditions (room temperature 21oC, 14 hs daylight, and 10 hs dark) with 62.5 mg/L and 117.6 mg/L of water solution of cinoxacin, using aquarium water. They were compared to control group of organisms. For conventional transmission electron microscopy standard preparation methods were used. Treated as well as control endosymbiotic organisms were fixed with 1% glutaraldehyde pH 6.9, buffered with sodium-cacodylate and postfixed with 1% osmium-tetroxide buffered with the same buffer. Afterwards, material was dehydrated in the ethanol-series, immersed in araldite and cut with the glass knife on the ultramicrotome. Preparations were dyed with 4% Pb-citrate and uranil-acetate. Micrographs were made using electron microscope Zeiss EM10A. Endosymbiotic green algae of Chlorella vulgaris species were damaged. Changes in algal structure and ultrastructure were observed. It was remarked that cinoxacin had the strongest effect on endosymbiotic alga performing 72 hs treatment especially higher concentration concerned. Antichloroplastal and antimitochondrial effect was the most expressed. In some algae irregularities in chloroplastal thylakoide system were observed. Thylakoides changed their shape or they were swollen. Mitochondria increased in size. They were also swollen (Fig. 2). Cinoxacin belongs to quinolone and fluoroquinolone group of antibiotics. It blocks the synthesis of bacterial DNA by inhibition of DNA gyrase enzyme. Since it is assumed that chloroplasts and mitochondria originated from eubacteria, it was expected to trace damages on these organelles. Except these strongest damages on chloroplasts and mitochondria, changes were observed also on other cell-components of green algae. Ribosomes decreased in number. Plastoglobules increased in size and number. Different kinds of membrane structures were formed inside the vacuole in the shape of osmiophyllic and myelin figures. These manifestations are known response to the antibiotic treatment3. Tough cell wall was also damaged. Less damaged organisms regenerated after a period of time and made normal endosymbiotic interaction again. From the results it could be concluded that cinoxacin showed the toxic effect and that toxicity resulted in structural and numerous ultrastructural changes of green alga. Results of research on the field of antichloroplastal and antimitochondrial effect of antibiotics point out the evolutionary connection of chloroplasts and mitochondria with eubacteria and their prokaryotic origin.

Pejzaži hrvatske.

The toxic effect of antibiotic ciprofloxacino on the ultrastrucfures of endosymbiotic alga from green hydra (Hydra viridissima Pallas) was studied. The individuals of green alga (Chlorella vulgaris are placed in gastrodermal myoepithelial cells of hydrra, as endosymbionts. Green hydras were treated under laboratory conditions with 1 g/L and 5 g/L of water solution of ciprofloxacin. For electronic microscopy treated and control animals were fixed with 1% glutaraldehyde pH 6.9, buffered with 0.01% Na-cacodylate and postfixed with l% osmium-tetroxide buffered with the same buffer. Afterwards material was dehydrated in ethanol-series, immersed in araaldite and cut with the glass knife on the ultaramicrotome. Preperations were dyed with Pb-citrate and uranyl-acetate. Micrographs werem made by the electronic microscope Zeiss EMl0A. It was remarked that ciprofloxacin has the strongest effect on the ultrastructures of green alga 72hs after the treatment, especially the higher concentration. Antichloroplastal and antimitochondrial effect was the most expressed. Ciprofloxacin blocks the synthesis of bacterial DNA by inhibition of the DNAgyrase enzyme. Since it is assumed that chloroplastsa and mitochondria have the eubacterial origin, it was expected to trace damagese exactly on these organelles. Changes were observed also on the structures of other cell-components such as ribosomes and plastoglobules. Also, different membrane structures formed as the effect of antibiotic treatment like osmiophyllic and myeline figures in the vacuoles of algae could be observed. Less damaged organisms recovered after a period of time and made normal symbiotic interactio again.

Planarije su često upotrebljavani test organizmi pa se često proučavaju kao zanimljiv eksperimentalni objekt.

The effect of chloramphenicol on the symbiosis between alga and hydra.

The toxic effects of chloramphenicol, ciprofloxacin and cinoxacin on endosymbiotic alga from green hydra were observed by means of electron microscope. Mitochondria were swollen, chloroplastal thylakoids were destroyed.

Green alga of Chllorella genus is the endosymbiont in gastrodermal myoepithelial cells of green hydra. The aim of this study was to establish the toxic effects of antibiotic ciprofloxcin on their relationship. Animals were treated with 0.5, 1.0 and 5.0 g/L of water solution of ciprofloxacin. Sections were observed by means of light and electron microscope. Ciprofloxacin caused mortality morphological, cytological and ultrastructural changes in both hydra and alga.

Snimljeni su HeI fotoelektronski spektri 11 seskviterpena. Elektronski sustavi su pripisani ionizaciji iz pi, Walshovih i sigma orbitala na temelju semiempirijskih kvantnokemijskih računa pod pretpostavkom da vrijedi Koopmansov teorem. Pokazano je da energije pi i Walshovih orbitala ovise o sigma kosturu, te o drugim pi ili Walshovim orbitalama zbog djelovanja kroz vezu i djelovanja kroz prostor. Na temelju prve ionizacijske energije procijenjena je energija HOMO orbitale, a na temelju energija UV-Vis spektara, procijenjene su energije LUMO orbitala.

Voda je izvor svega živoga.

Duga povijest multiplih hominidnih vrsta koje se bore za prevlast na Zemlji završila je. Nakon milijun godina, evolucija prirodnom selekcijom, djelujući naslijepo i slučajno, proizvela je stvorenje koje je sposobno preokrenuti evoluciju na svoju ruku. Kamo ćemo od ove točke u vremenu, ovisi o nama samima.

Utvrđen je toksični učinak kloramfenikola na hidru. Ovaj antibiotik je uzrokovao smrtnost, promjene u lokomociji, morfološke, citološke i histološke proimjene na hidri te oštećenja u algalnoj ultrastrukturi, naročito mitohondrija i kloroplasta. Istraživanja s ovog područja prilog su endosimbiotskoj teoriji o postanku eukariotske stanice.

Hidra kao jedinka jest pojedinačni polip cilindrična oblika koji nastava kopnenim stajaćim vodama. U prirodi je lako dostupna. Hidre imaju veoma zanimljivu anatomsku i citološku građu, a kao eksperimentalne životinje proučavaju se više od 250 godina.

Razumijevanjem kemizma i ekoloških interakcija spojeva kojima se sluzimo u svakodnevnom životu i industriji možemo doći do vrijednih saznanja o očuvanju ljudskog zdravlja i prirodnog okoliša.

Sažeta saznanja o parku prirode Medvednica, iz mnogih aspekata ljudskog života, uključujući očuvanje biodiverziteta, zaštitu prirode i dr.

Praćen je učinak antibiotika kloramfenikola na simbiozu alge i hidre. Utvrđeno je izrazito djelovnje agensa na navedenu simbiozu. Pupanje je bilo smanjeno, a smrtnost izražena. Utvrđene su promjene na svim staničnim slojevima hidre te izbjeljivanje i promjene u položaju i strukturi algi. Neke hidre ostale su trajno deformirane, dok su se preostale uspješno regenerirale. Ovim pokusom potvrđeno je da antibiotik ima svoju točno određenu koncentraciju u kojoj pokazuje svoje najučinkovitije djelovanje.

Koristeći se podacima iz preliminarnog projekta plovnog pritegnutog mosta određene su osnove analize opterećenja konstrukcije. Posebna pozornost posvećena je utjecaju vjetra i valova na konstrukciju.