85 research outputs found
What countries select more experienced Leaders? The PolEx measure of political experience
How can we assess which countries select more experienced leaders for the highest oce? There is a wide variation in
prior career paths of national leaders within, and even more so between, regime types. Obtaining a truly comparative
measure of political experience is therefore a challenge and empirical studies have to rely on proxies instead. We propose
PolEx, a measure of political experience that abstracts away from the details of the career paths and generalises based on
duration of experience in politics, its quality, and its breadth. We draw on a novel data set of around 2,000 leaders from
1950 to 2017 and use a Bayesian latent variable model to estimate PolEx. We illustrate how the new measure can be
used comparatively by addressing the question whether democracies select more experienced leaders. We find that while
on average they do, this century the dierence with non-democracies has declined dramatically. Future research may
leverage PolEx to investigate the role of prior political experience in, for example, policy-making and crisis management
On the maximal number of cubic subwords in a string
We investigate the problem of the maximum number of cubic subwords (of the
form ) in a given word. We also consider square subwords (of the form
). The problem of the maximum number of squares in a word is not well
understood. Several new results related to this problem are produced in the
paper. We consider two simple problems related to the maximum number of
subwords which are squares or which are highly repetitive; then we provide a
nontrivial estimation for the number of cubes. We show that the maximum number
of squares such that is not a primitive word (nonprimitive squares) in
a word of length is exactly , and the
maximum number of subwords of the form , for , is exactly .
In particular, the maximum number of cubes in a word is not greater than
either. Using very technical properties of occurrences of cubes, we improve
this bound significantly. We show that the maximum number of cubes in a word of
length is between and . (In particular, we improve the
lower bound from the conference version of the paper.)Comment: 14 page
Diversity of Mobile Genetic Elements in the Mitogenomes of Closely Related Fusarium culmorum and F. graminearum sensu stricto Strains and Its Implication for Diagnostic Purposes
Much of the mitogenome variation observed in fungal lineages seems driven by mobile genetic elements (MGEs), which have invaded their genomes throughout evolution. The variation in the distribution and nucleotide diversity of these elements appears to be the main distinction between different fungal taxa, making them promising candidates for diagnostic purposes. Fungi of the genus Fusarium display a high variation in MGE content, from MGE-poor (Fusarium oxysporum and Fusarium fujikuroi species complex) to MGE-rich mitogenomes found in the important cereal pathogens F. culmorum and F. graminearum sensu stricto. In this study, we investigated the MGE variation in these latter two species by mitogenome analysis of geographically diverse strains. In addition, a smaller set of F. cerealis and F. pseudograminearum strains was included for comparison. Forty-seven introns harboring from 0 to 3 endonucleases (HEGs) were identified in the standard set of mitochondrial protein-coding genes. Most of them belonged to the group I intron family and harbored either LAGLIDADG or GIY-YIG HEGs. Among a total of 53 HEGs, 27 were shared by all fungal strains. Most of the optional HEGs were irregularly distributed among fungal strains/species indicating ancestral mosaicism in MGEs. However, among optional MGEs, one exhibited species-specific conservation in F. culmorum. While in F. graminearum s.s. MGE patterns in cox3 and in the intergenic spacer between cox2 and nad4L may facilitate the identification of this species. Thus, our results demonstrate distinctive traits of mitogenomes for diagnostic purposes of Fusaria
Diversity of mobile genetic elements in the mitogenome of closely related Fusarium culmorum and F. graminearum sensu stricto strains ans its implication for diagnostic purposes
Much of the mitogenome variation observed in fungal lineages seems driven by mobile genetic elements (MGEs), which have invaded their genomes throughout evolution. The variation in the distribution and nucleotide diversity of these elements appears to be the main distinction between different fungal taxa, making them promising candidates for diagnostic purposes. Fungi of the genus Fusarium display a high variation in MGE content, from MGE-poor (F. oxysporum and Fusarium fujikuroi species complex) to MGE-rich mitogenomes found in the important cereal pathogens F. culmorum and F. graminearum sensu stricto. In this study, we investigated the MGE variation in these latter two species by mitogenome analysis of geographically diverse strains. In addition, a smaller set of F. cerealis and F. pseudograminearum strains was included for comparison. Forty-seven introns harboring from 0 to 3 endonucleases (HEGs) were identified in the standard set of mitochondrial protein-coding genes. Most of them belonged to the group I intron family and harbored either LAGLIDADG or GIY-YIG HEGs. Among a total of 53 HEGs, 27 were shared by all fungal strains. Most of the optional HEGs were irregularly distributed among fungal strains/species indicating ancestral mosaicism in MGEs. However, among optional MGEs, one exhibited species-specific conservation in F. culmorum. While in F. graminearum s.s. MGE patterns in cox3 and in the intergenic spacer between cox2 and nad4L may facilitate the identification of this species. Thus, our results demonstrate distinctive traits of mitogenomes for diagnostic purposes of Fusaria.Fil: Kulik, Tomasz. Department Of Botany And Nature Protection, University; PoloniaFil: Brankovics, Balazs. Wageningen Plant Research, Wageningen University; Países BajosFil: Van Diepeningen, Anne D.. Waneningen Plant Research; Países BajosFil: Bilska, Katarzyna. Department Of Botany And Nature Protection, University; PoloniaFil: Zelechowski, Maciej. Department Of Botany And Nature Protection, University; PoloniaFil: Myszczyński, Kamil. Department Of Botany And Nature Protection, University; PoloniaFil: Molcan, Tomasz. Faculty Of Biology And Biotechnology, University; PoloniaFil: Stakheev. Alexander. Institute Of Bioorganic Chemistry (ras); RusiaFil: Stenglein, Sebastian Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnolológico Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología. Laboratorio de Biología Funcional y Biotecnología; ArgentinaFil: Beyer, Marco. Luxembourg Institute Of Science And Technology; LuxemburgoFil: Pasquali, Matias. Faculty Of Agricultural And Food Sciences; ItaliaFil: Sawicki, Jakub. Department Of Botany And Nature Protection, University; PoloniaFil: Baturo Cieśniewska, Anna. Baturo-cieśniewska; Poloni
Immunochemical studies of the lipopolysaccharides of Hafnia alvei PCM 1219 and other strains with the O-antigens containing D-glucose 1-phosphate and 2-deoxy-2-[(R)-3-hydroxybutyramido]-D-glucose
Health status of five spring barley cultivars cultivated under organic system
The objective of the study was to compare health status of harvested grain of spring barley cv. Rudzik, Rodos, Start and Maresi cultivated in organic system and cv. Damazy grown in an organic farm. Analyses showed that prevalent pathogen on grain was Bipolaris sorokiniana isolated from 48% of grains. Fungi from genus of Fusarium were obtained less numerously, from 27% of grains and were represented mainly by F. poae and F. avenaceum. Microscopic analysis of F. poae was confirmed by PCR analysis.
All cultivars were intensively diseased by B. sorokiniana, thus it is impossible to show a cultivar especially recommended for this system, where B. sorokiniana can be serious problem. However cv. Damazy showed relatively the lowest infestation by B. sorokiniana and it also was not more intensively diseased by Fusarium spp. It is very important in nutrition aspect because these fungi can be dangerous for both human and animal health due to their abilities to produce mycotoxins.Porównano zdrowotność ziarna jęczmienia odmian Rudzik, Rodos, Start i Maresi uprawianego w ekologicznym systemie uprawy na polach doświadczalnych oraz odmiany Damazy uprawianej w gospodarstwie ekologicznym. Stwierdzono, że B. sorokiniana był głównym z patogenów bytujących na ziarnie i zasiedlał średnio 47% ziarniaków. Grzyby z rodzaju Fusarium występowały w niższym nasileniu, zasiedlając 27% ziarniaków i reprezentowane były głównie przez F. poae i F. avenaceum. Przynależność gatunkową F. poae potwierdzono za pomocą PCR. Wszystkie z badanych odmian wykazywały wysokie porażenie przez B. sorokiniana zatem nie można wskazać odmiany szczególnie polecanej do uprawy w systemie ekologicznym, gdzie B. sorokiniana stanowi poważny problem. Odmiana Damazy okazała się stosunkowo najbardziej odporną na B. sorokiniana i jednocześnie nie silniej niż pozostałe porażaną przez grzyby z rodzaju Fusarium. Jest to niezwykle istotne z żywieniowego punktu widzenia, gdyż Fusarium spp. mogą być szkodliwe ze względu na możliwość tworzenia mykotoksyn
- …