Evaluation of interspecific DNA variability in poplars using AFLP and SSR markers

The objective of this paper was to examine interspecific DNA variation in poplars using AFLP and SSR markers. The AFLP and SSR markers polymorphism and its power of discrimination were determinedwithin 13 genotypes of different genetic background (clones, cultivars, hybrids) of two sections (Aigeiros and Tacamahaca) of genus Populus. Twelve sets of PTR and four sets of WPMS microsatellite primers as well as 6 AFLP primer combinations were used in this study. SSR and AFLP markers revealed high power of discrimination, 0.81 and 0.92 respectively. Results obtained using SSR data showed a clear separation of three major clusters, while four major clusters were obtained using AFLP data. Both markers crearly separated two distinct clusters, one included Populus nigra and the other Populus deltoides genotypes. According to both markers, different genetic background were revealed between two clones of Populus trichocarpa. When evaluating polymorphisms within genotypes ofinterest, microsatellite and AFLP DNA markers proved to be a useful tool for distinguishing genetic background of tree clones, cultivars and hybrid genotypes thus grouping them according to their genetic dissimilarity. The results presented in this study could be of significant interest in poplarbreeding programs and could also be used as a valuable annex in new bred clones registration process

No one asks the children, right?

Modern tourism planning and development of a destination should include input from all levels of society, including different age groups and varying interest groups within a local community. However, it is very rare that, in the process of participatory planning, youths and school groups are invited to express their views on development plans or have the opportunity to take an active part in decision-making. In this study, a nonverbal semantic differential was used in order to learn about how children in Slovenian primary schools view tourists and tourism. A sample of students from three primary schools located in developed, semi developed and poorly developed tourist destinations completed an "activity book" containing questions and a methodology for drawing a picture of "tourists", "hosts", and "children\u27s parents\u27 perception of tourists". This study showed that children from regions where tourism is highly developed have significantly different attitudes toward tourists than children living in regions where tourism is not as developed. However, the study also takes a perspective of the importance of sustainability in the tourism offer and how this may affect the views of children & youth in general and in different regions in particular

Gauge transformations and symmetries of integrable systems

We analyze several integrable systems in zero-curvature form within the framework of $SL(2,\R)$ invariant gauge theory. In the Drienfeld-Sokolov gauge we derive a two-parameter family of nonlinear evolution equations which as special cases include the Kortweg-de Vries (KdV) and Harry Dym equations. We find residual gauge transformations which lead to infinintesimal symmetries of this family of equations. For KdV and Harry Dym equations we find an infinite hierarchy of such symmetry transformations, and we investigate their relation with local conservation laws, constants of the motion and the bi-Hamiltonian structure of the equations. Applying successive gauge transformatinos of Miura type we obtain a sequence of gauge equivalent integrable systems, among them the modified KdV and Calogero KdV equations.Comment: 18pages, no figure Journal versio

Femtosecond x-ray diffraction from an aerosolized beam of protein nanocrystals

We demonstrate near-atomic-resolution Bragg diffraction from aerosolized single granulovirus crystals using an x-ray free-electron laser. The form of the aerosol injector is nearly identical to conventional liquid-microjet nozzles, but the x-ray-scattering background is reduced by several orders of magnitude by the use of helium carrier gas rather than liquid. This approach provides a route to study the weak diffuse or lattice-transform signal arising from small crystals. The high speed of the particles is particularly well suited to upcoming MHz-repetition-rate x-ray free-electron lasers

Dinamika proizvodnje deoksinivalenola i zearalenona kod izolata Fusarium graminearum u laboratorijskim uslovima

Toxicological investigations encompassed two cultures of Fusarium graminearum: (i) D2 isolate, originating from air was obtained on Sabouraud medium during a routine control of laboratory sterility conditions at the Department of Microbiology of the Center for Bio-Ecology in 2006, and (ii) GZ-LES control isolate, a well known producer of zearalenone (ZON) and deoxynivalenol (DON), was isolated from maize kernel collected at Leskovac in 1975. Preliminary analysis of fungal potential for the production of DON and ZON were performed by the modified rapid screening method of Filtenborg et al. (1983). Dynamics of DON and ZON biosynthesis was tested under different conditions of isolate cultivation: (i) in a basic liquid semi-synthetic medium with 2% yeast extract and 15% sucrose, pH 6.5 (YES), (ii) in broth with same concentrations of yeast extract and sucrose supplemented with 0.23 mg/l ZnSO4 x 5 H2O, pH 6.5 (YESZn) and (iii) on natural solid substrates such as wet sterilized maize and rice kernels. The quantitative determination of DON and ZON was performed in both liquid and natural solid substrates with thin-layer chromatographic methods (TLCs). The maximum yield of DON was recorded after three weeks of cultivation on maize kernels at 27±1°C. Contrary to the D2 isolate, which did not show the potential for the DON biosynthesis, the control isolate GZ-LES produced 645.6 ppb of the same type B trichothecene under previously mentioned conditions. The ZON biosynthesis by the isolate D2 (1.2 ppb) was observed after 2 weeks of the stationary cultivation in YES and YESZn at room temperature (17-19°C). The same isolate produced 0.74 ppb and 17.35 ppb ZON on maize and rice kernels after only 7 and 28 days of cultivation at the room temperature ranging from 17 to 19°C and from 15 to 23°C, respectively.Ispitivanjem su bili obuhvaćeni novoizolovana kultura F. graminearum (D2) neispitanog toksikološkog profila i kontrolni izolat iste vrste gljive (GZ-LES) dobro poznat proizvođač deoksinivalenola (DON) i zearalenona (ZON). Preliminarne analize DON-a i ZON-a su izvršene prema modifikovanoj metodi Filtenborga i sar. (1983). Dinamika biosinteze DON-a i ZON-a je praćena gajenjem izolata gljiva u/na četiri različita tipa podloge: tečnoj polusintetičkoj podlozi sa 2% ekstrakta kvasca i 15% saharoze (YES pH 6,5), podlozi istog sastava sa dodatkom 0,23 mg/l ZnSO4 x 5 H2O (YESZn pH 6,5) i sterilisanim vlažnim zrnima kukuruza i pirinča. Kvantitativno određivanje DON-a u kulturi izolata gljiva gajenih u tečnoj podlozi je izvršeno tankoslojnom hromatografijom prema Cvetniću i sar. (2005), a u čvrstoj podlozi primenom postupka autora Pepeljnjaka i Babića (1991). Potencijal za biosintezu ZON-a kod izolata gajenih u tečnoj podlozi je određivan postupkom tankoslojne hromatografije prema Bočarov - Stančić i sar. (2003), a izolata gajenih na čvrstoj podlozi prema Balzeru i sar. (1978). Maksimalna koncentracija DON-a (645,6 ppb) je determinisana posle tri nedelje kultivacije kontrolnog izolata F. graminearum GZ-LES na zrnu kukuruza i pri 27±1°S. Za izolat iste vrste gljive D2 je utvrđeno da ne poseduje sposobnost biosinteze DON-a, s obzirom da nije proizvodio ovaj trihotecen tipa B ni u jednom od testiranih uslova kultivacije. Proizvodnja ZON-a je konstatovana kod izolata D2 (1,2 ppb, odnosno 1,5 ppb) posle dve nedelje stacionarne kultivacije u tečnim podlogama (YES i YESZn) na sobnoj temperaturi od 17 do 19°C. Na prirodnim čvrstim supstratima (zrno kukuruza i pirinča) isti izolat je biosintetisao ZON već posle sedam dana kultivacije na zrnu kukuruza i sobnoj temperaturi od 17 do 19°C (0,74 ppb) ili posle 28 dana kultivacije na zrnu pirinča i sobnoj temperaturi od 15 do 23°C (17,4 ppb)

Gravastar energy conditions revisited

We consider the gravastar model where the vacuum phase transition between the de Sitter interior and the Schwarzschild or Schwarzschild-de Sitter exterior geometries takes place at a single spherical delta-shell. We derive sharp analytic bounds on the surface compactness (2m/r) that follow from the requirement that the dominant energy condition (DEC) holds at the shell. In the case of Schwarzschild exterior, the highest surface compactness is achieved with the stiff shell in the limit of vanishing (dark) energy density in the interior. In the case of Schwarzschild-de Sitter exterior, in addition to the gravastar configurations with the shell under surface pressure, gravastar configurations with vanishing shell pressure (dust shells), as well as configurations with the shell under surface tension, are allowed by the DEC. Respective bounds on the surface compactness are derived for all cases. We also consider the speed of sound on the shell as derived from the requirement that the shell is stable against the radial perturbations. The causality requirement (sound speed not exceeding that of light) further restricts the space of allowed gravastar configurations.Comment: LaTeX/IOP-style, 16 pages, 2 figures, changes wrt v1: motivation for eq. (6) clarified, several referecnes added (to appear in Class. Quantum Grav.

B --> pi and B --> K transitions in partially quenched chiral perturbation theory

We study the properties of the B-->pi and B-->K transition form factors in partially quenched QCD by using the approach of partially quenched chiral perturbation theory combined with the static heavy quark limit. We show that the form factors change almost linearly when varying the value of the sea quark mass, whereas the dependence on the valence quark mass contains both the standard and chirally divergent (quenched) logarithms. A simple strategy for the chiral extrapolations in the lattice studies with Nsea=2 is suggested. It consists of the linear extrapolations from the realistically accessible quark masses, first in the sea and then in the valence quark mass. From the present approach, we estimate the uncertainty induced by such extrapolations to be within 5%.Comment: Published versio

In-Spray Supercharging of Peptides and Proteins in Electrospray Ionization Mass Spectrometry

Enhanced charging, or supercharging, of analytes in electrospray ionization mass spectrometry (ESI MS) facilitates high resolution MS by reducing an ion mass-to-charge (m/z) ratio, increasing tandem mass spectrometry (MS/MS) efficiency. ESI MS supercharging is usually achieved by adding a supercharging reagent to the electrospray solution. Addition of these supercharging reagents to the mobile phase in liquid chromatography (LC)-MS/MS increases the average charge of enzymatically derived peptides and improves peptide and protein identification in large-scale bottom-up proteomics applications but disrupts chromatographic separation. Here, we demonstrate the average charge state of selected peptides and proteins increases by introducing the supercharging reagents directly into the ESI Taylor cone (in-spray supercharging) using a dual-sprayer ESI microchip. The results are comparable to those obtained by the addition of supercharging reagents directly into the analyte solution or LC mobile phase. Therefore, supercharging reaction can be accomplished on a time-scale of ion liberation from a droplet in the ESI ion source

No one asks the children, right?

Modern tourism planning and development of a destination should include input from all levels of society, including different age groups and varying interest groups within a local community. However, it is very rare that, in the process of participatory planning, youths and school groups are invited to express their views on development plans or have the opportunity to take an active part in decision-making. In this study, a nonverbal semantic differential was used in order to learn about how children in Slovenian primary schools view tourists and tourism. A sample of students from three primary schools located in developed, semi developed and poorly developed tourist destinations completed an "activity book" containing questions and a methodology for drawing a picture of "tourists", "hosts", and "children\u27s parents\u27 perception of tourists". This study showed that children from regions where tourism is highly developed have significantly different attitudes toward tourists than children living in regions where tourism is not as developed. However, the study also takes a perspective of the importance of sustainability in the tourism offer and how this may affect the views of children & youth in general and in different regions in particular