Coordination between cell size and chromatin structure

Cells change size during the cell cycle and in response to external conditions. In order to maintain biomolecule concentrations, gene expression is coordinated with cell size in a process called “scaling”. In fission yeast, scaling has been found to be associated with a genome-wide increase in transcription initiation rates and RNA polymerase II occupancy. However, the mechanistic details that underpin this global increase in transcription have not been defined yet. Since transcription initiation operates in the context of chromatin, we hypothesize that global transcriptional scaling is in part regulated by changes in chromatin state that reflect cell-size increase. To test this hypothesis, we used an analogue sensitive strain of the cyclin-dependent protein kinase Cdc2 (cdc2-asM17). Upon analogue treatment this strain exits the cell cycle in G2 and grows up to a size 3-4 times larger than wild-type after 6h of treatment. By mapping nucleosome occupancy in arrested cdc2-asM17 cells of increasing size, I uncover the link between cell size and the global chromatin architecture. More precisely, I show that cell size increase is accompanied by an increasing occupancy at promoters. These factors occupying the promoter in large cells are MNase-sensitive factors, suggesting that they are not canonical nucleosomes. Moreover, I report that a marker of transcription initiation, H3K9ac, scales with cell size, suggesting a possible role of this post-translational modification in setting a favorable context for an increasing occupancy at promoter of larger cells. Finally, comparing the genome wide distribution of H3 between normal and large cells reveals that for most genes, the protein complex occupying the promoter of large cells is not composed of H3, suggesting that they are not nucleosomal particles, although some promoters indeed present an enrichment of H3 upon cell size increase. Altogether, this work provides insights into the mechanism that regulates scaling.Open Acces

Photocatalytic decomposition of nitrous oxide using TiO2 and Ag-TiO2 nanocomposite thin films

TiO2 and Ag-TiO2 (0.05, 0.25 and 1 wt% of Ag) thin films were prepared by the sol–gel method. The prepared films were characterized using SEM-EDAX, XRD, Raman spectroscopy, atomic force microscopy and UV–Vis spectrometry. Photocatalytic decomposition of N2O was performed in an annular batch reactor illuminated with an 8 W Hg lamp (254 nm wavelength). The photoreactivity of Ag-TiO2 increases with the Ag amount to 0.25 wt% Ag. Further increase of Ag loading to 1 wt% Ag did not change N2O conversion. The Ag particles deposited on the TiO2 surface can act as electron–hole separation centers. The presence of water vapor and oxygen in the reaction mixture slightly improved N2O conversion.Web of Science20917517

Plant economy during the Neolithic in a mountain context: the case of "Le Chenet des Pierres” in the French Alps (Bozel-Savoie, France)

The analyses of archaeobotanical assemblages recovered in recent excavations in the northern French Alps permit a better understanding of the way people managed plant resources in a mountain context during the Middle Neolithic (4500-3500cal b.c.). The aim of this paper is to shed new light on the question of crop cultivation as well as wood gathering and management from the results of the new archaeobotanical investigations at "Le Chenet des Pierres” in Bozel (Savoie, France; 1,000m. a.s.l.). The study reveals the presence of cereals like einkorn (Triticum monococcum), emmer (T. dicoccum), naked wheat (T. aestivum/durum/turgidum) and barley (Hordeum vulgare/distichon). In addition wild fruits and nuts, probably gathered, such as hazelnuts (Corylus avellana), wild apples (Malus sylvestris), arolla pine kernels (Pinus cembra), sloes (Prunus spinosa) and raspberries (Rubus idaeus) were recorded. The anthracological analysis shows that the occupants exploited mostly a mixed oak forest, and the available woodland from the alluvial forest to the mountain areas. With the archaeobotanical study of "Le Chenet des Pierres” we also want to raise the question of crop cultivation in a mountain context. Although present data show that cultivation at higher altitudes is common, it is still difficult to demonstrate the inhabitants cultivated plants near their settlement during the Neolithi

Education in the Czech Republic: A Comparative Analysis on the Case of the University of Pardubice

Public administration is overwhelmingly crucial in providing citizens with the best accessible, affordable, effective, and efficient services. Governments need qualified human resources for satisfactory employment processes. Therefore, higher education institutions play a crucial role in supplying the education in the field of public administration. Universities and various institutes from all over the world have numerous public administration education programmes. In this context, students as well as professionals have a wide range of opportunities to get an education in public administration so as to be employed in the public or relevant sectors. In parallel with globalisation and the development of information technologies, new professions have started to emerge and significant changes have been observed in people’s learning preferences. The Czech Republic is one of the significant Central European countries to offer an education in public administration. To this end, the study examines public administration education in the Czech Republic and looks more closely at public administration education at the University of Pardubice, which offers programmes in the area of public administration and the public sector. The analysis is performed based on a statistical evaluation of students’ interest over a span of 16 years. Finally, the demand for public administration education at the University of Pardubice is analysed in order to put forth the current state of public administration education by comparing it with other relevant faculties in the Czech Republic. The conclusion of the study is devoted to considerations on the possibilities of supporting education in the Czech Republic. More consistent supervision from the position of the state seems appropriate, but also support for a family policy aimed at reconciling professional and family life

The use of rituals at primary school

The paper presents school rituals and their possible use at primary school. Its aim is to show the options of use of rituals in teaching.The authors first define the rituals in general and then characterise the school rituals. Based on a survey they show how the rituals are being used in a school environment. First, they divide the rituals into welcoming, valedictory, educational and celebratory. At the end, they document the main advantages that the respondents see in the use of rituals in their practice. The study results show that nowadays the rituals are an integral part of education at primary school and point to positives, which brings the use of rituals. There is also mentioned possible drawbacks that are related to the research of school rituals

House Prices and Marital Stability

We investigate the effect of house price changes on divorce using data for 1991-2010 from the Current Population Survey and the Federal Housing Finance Agency. Our findings suggest that changing house prices significantly affect the share of a cohort that is divorced, and that these effects are asymmetric with respect to housing gains versus losses. In addition, we find differential effects for groups that are more likely to be homeowners versus renters. Some of this evidence is consistent with homeowners being locked into their homes-and hence marriages-by increased transactions costs in down markets

Mass Spectrometric Characterization of Oligomers in Pseudomonas aeruginosa Azurin Solutions

We have employed laser-induced liquid bead ion desorption mass spectroscopy (LILBID MS) to study the solution behavior of Pseudomonas aeruginosa azurin as well as two mutants and corresponding Re-labeled derivatives containing a Re(CO)_(3)(4,7-dimethyl-1,10-phenanthroline)^+ chromophore appended to a surface histidine. LILBID spectra show broad oligomer distributions whose particular patterns depend on the solution composition (pure H_(2)O, 20−30 mM NaCl, 20 and 50 mM NaP_i or NH_(4)P_i at pH = 7). The distribution maximum shifts to smaller oligomers upon decreasing the azurin concentration and increasing the buffer concentration. Oligomerization is less extensive for native azurin than its mutants. The oligomerization propensities of unlabeled and Re-labeled proteins are generally comparable, and only Re126 shows some preference for the dimer that persists even in highly diluted solutions. Peak shifts to higher masses and broadening in 20−50 mM NaP_i confirm strong azurin association with buffer ions and solvation. We have found that LILBID MS reveals the solution behavior of weakly bound nonspecific protein oligomers, clearly distinguishing individual components of the oligomer distribution. Independently, average data on oligomerization and the dependence on solution composition were obtained by time-resolved anisotropy of the Re-label photoluminescence that confirmed relatively long rotation correlation times, 6−30 ns, depending on Re−azurin and solution composition. Labeling proteins with Re-chromophores that have long-lived phosphorescence extends the time scale of anisotropy measurements to hundreds of nanoseconds, thereby opening the way for investigations of large oligomers with long rotation times

Identification of Employees' Preferences for Health and Wellness Programmes

Today's workplace has created new challenges and opportunities for managers, as employees from three generations (Millennials, Generation X and Baby boomers) with different personal characteristics now form the workforce. It is crucial for a company's management to understand employees' needs regarding benefits, since employees' satisfaction is vital to their motivation and productivity. In this study, we analysed responses from 272 employees to a survey about their preferences for Health & Wellness programmes, using the Analytical Hierarchy Process methodology. The results reveal significant differences between generations, as well as between genders. The most desired programmes for younger generations are educational packages, whereas Baby boomers tend to prefer cultural events. Despite these differences, there is consensus among all the generations about the high importance of dental care programmes

Obecné požadavky kvality programových dokumentů

The systematic tourism promotion can be understood as a specific tool of a regional policy of the Czech regions. At the present time almost all regions have disposed of a particular programme document focused on a development of tourism in a given region. Nevertheless these documents are considerably different in the case of their form and content. That is why an evaluation of their quality is quite difficult. One of the reasons of this situation is an absence of the requirements on a quality of these documents. This paper resulted from the methodological concept which aim is to set the basic requirements on the form and content of the programme documents