Influence of Different Yeast Strains on Metabolism of Tryptophan and Indole-3-Acetic Acid During Fermentation

The effect of supplementation of Riesling (Vitis vinifera L.) must with ammonium sulphate (AS) ontryptophan (Trp) and indole-3-acetic acid (IAA) metabolism during alcoholic fermentation with fourcommercial yeast strains (Uvaferm CEG, Lalvin Cross Evolution, Anchor VIN 13 and Anchor exoticSPH) were examined. AS addition reduced Trp uptake by yeasts from 1% to 15%. Wines produced byAnchor VIN 13 and Uvaferm CEG yeasts with AS addition had the highest concentrations of Trp (0.60and 0.59 mg/L respectively). Concentrations of total and bound IAA decreased during all treatments. Atthe end of fermentation the highest concentration of free IAA was measured in the control must inoculatedwith Anchor VIN 13 yeast (35.83 μg/L) and the lowest in the sample inoculated with Uvaferm CEG yeast(13.08 μg/L). Anchor VIN 13 yeast showed the strongest change in metabolism due to AS addition duringfermentation. 2-Aminoacetophenone (2-AAP) formation was not observed in all the studied wines

THE QUALITY OF WATER AND ICHTHIOFAUNA OF THE SOUTHERN LAKE IN OSIJEK – THE CONDITIONS FOR BIOMANIPULATION

Južno je jezero plitko (do 4 m dubine) umjetno jezero, površine 2,5 ha, a nalazi se unutar urbane cjeline grada Osijeka. Nakon dugogodišnjeg onečišćenja godine 1995. otpočela je njegova revitalizacija. Rezultati provedenih hidrobioloških istraživanja pokazuju osnovna ekološka obilježja Južnog jezera: veliku prozirnost vode, veliku količinu nutrijenata i bogato razvijenu makrofitsku vegetaciju. Analizom kvalitativnog sastava ihtiofaune utvrđeno je 13 vrsta riba iz 6 porodica, od kojih je vrstama najbrojnija porodica Cyprinidae. U kvantitativnom sastavu ihtiofaune brojnošću prevladava bezribica, a dobro su zastupljene sunčanica, babuška, crvenperka i bodorka. U trofičnoj je strukturi odnos grabežljivih vrsta prema mirnim vrstama nepovoljan. Radi daljnje revitalizacije Južnog jezera predlaže se primjena metode biomanipulacije: količinu makrofitske vegetacije smanjiti njezinim izravnim uklanjanjem i unosom biljoždernih vrsta riba, a nepovoljne trofične odnose unutar ihtiofaune mijenjati izlovom grabežljivih vrsta i unosom mirnih vrsta riba.The Southern lake is shallow (deep up to 4 meters) artificial lake with the ackerage of 6. 25. It is situated within the city of Osijek. Its reconstruction began in 1995, after it has been polluted for many years. The results of, hydrobiological examination show the basic ecological characteristics of the Southern lake: high transparency, great quantity of nutrients and highly developed macrophit vegetation. After the conducted analysis of the qualitative composition of the ichthiofauna, it has been found that the lake has 13 species of fish form six families, with the greatest number of them coming from Cyprinidae family. idae family. The fish species that outnumbers all other in the quantitative composition of the ichtiofauna is P. parua, but also well represented are L. gibosus, C. carrasius gibelio, Scardinius erythrophthalmus and Rutilus rutilus. In the trophic structure, the ratio of the predatory species is disadvantageous in relation to the unpredatory species. The application of the biomanipulation method has been suggested for the further reconstruction of the Southern lake: the quantity of the macrophit vegetation should be reduced by the way of its direct removal and the input of the herbivore fish species. The disadvantageous trophic ratio should be changed by overfishing of predatory species within the ichthiofauna and the input of unpredatory fish species

Ampelographic and genetic characterization of Croatian grapevine varieties

Before the Phylloxera (Daktulosphaira vitifoliae) crisis in Croatia more than 400 grape varieties were under cultivation. Today their number is drastically decreased. Recently, many efforts in the preservation of grapevine biodiversity were undertaken: detailed inventory of varieties in different wine-growing regions, establishing of national and regional collections and their systematic ampelographic and genetic characterisation. This paper shows results of multiannual ampelographic and genetic research concerning Croatian grapevines considered as autochthonous varieties. After identification, many synonyms and homonyms were detected and unique genotypes were selected. Basic data of them are shown: description (according to OIV descriptors) and genetic profiles (9 SSR loci), growing area and status of vulnerability. Also, genetic relationship based on the shared allele distance is computed from SSR data. Results show certain level of similarity among varieties, and classify Croatia as important gene-pool in Europe. Some additional accessions which were detected and introduced into collections recently are still being investigated and characterized so that the here presented list of Croatian native grapevine cultivars is not final

The Historical Context of the Gender Gap in Mathematics

This chapter is based on the talk that I gave in August 2018 at the ICM in Rio de Janeiro at the panel on "The Gender Gap in Mathematical and Natural Sciences from a Historical Perspective". It provides some examples of the challenges and prejudices faced by women mathematicians during last two hundred and fifty years. I make no claim for completeness but hope that the examples will help to shed light on some of the problems many women mathematicians still face today

A generalized mathematical model for efficiency calibration of gamma detectors: Application to practical cases

Efficiency calibration, i. e. determination of detection efficiency, εp, is a crucial issue in gamma spectrometry (quantification of gamma spectroscopic measurements) with semiconductor and scintillation detectors. Comparing three possible ways to addressing the problem – relative, absolute and semi empirical – advantages of the latter are emphasized. Among semi empirical models, efficiency transfer using effective solid angles, Ω¯, is sorted out and briefly elaborated. This approach reduces the problem of efficiency calibration to the determination of Ω¯. It proved reliable and has been broadly used in practice, mainly in the form of the long existing ANGLE software. Progressing further, a generalized mathematical formula for calcu- lations is developed – first of the kind – offering an opportunity for advanced applications of gamma spectrometry. The formula enables unlimited flexibility in application, as it conveniently separates the source data from the detector data during the integration procedures Ω¯ calculations). Its practicality is demonstrated for a number of typically encountered counting arrangements, as well as for some exotic ones. The relevant formulae are used in PC calculations and numerical testing is further performed so as to check the validity of the mathematical method and the computer code. Care was taken of the optimization of complex numerical procedures employed (involving fivefold numerical integration), so as to keep computation times as low as possible (in order of minutes or even seconds on ordinary PC). Results obtained are affirmative for both the method and the code. The model will be gradually incorporated into ANGLE software, thus making it readily available for routine use by gamma spectrometry community