Thermal and mechanical properties of chitosan nanocomposites with cellulose modified in ionic liquids

In this paper, ionic liquid treatment was applied to produce nanometric cellulose particles of two polymorphic forms. A complex characterization of nanofillers including wide-angle X-ray scattering, Fourier transform infrared spectroscopy, and particle size determination was performed. The evaluated ionic liquid treatment was effective in terms of nanocrystalline cellulose production, leaving chemical and supermolecular structure of the materials intact. However, nanocrystalline cellulose II was found to be more prone to ionic liquid hydrolysis leading to formation larger amount of small particles. Each nanocrystalline cellulose was subsequently mixed with a solution of chitosan, so that composite films containing 1, 3, and 5% mass/mass of nanometric filler were obtained. Reference samples of chitosan and chitosan with micrometric celluloses were also solvent casted. Thermal, mechanical, and morphological properties of films were tested and correlated with properties of filler used. The results of both, tensile tests and thermogravimetric analysis showed a significant discrepancy between composites filled with nanocrystalline cellulose I and nanocrystalline cellulose II

Both tails and the centromere targeting domain of CENP-A are required for centromere establishment

The centromere—defined by the presence of nucleosomes containing the histone H3 variant, CENP-A—is the chromosomal locus required for the accurate segregation of chromosomes during cell division. Although the sequence determinants of human CENP-A required to maintain a centromere were reported, those that are required for early steps in establishing a new centromere are unknown. In this paper, we used gain-of-function histone H3 chimeras containing various regions unique to CENP-A to investigate early events in centromere establishment. We targeted histone H3 chimeras to chromosomally integrated Lac operator sequences by fusing each of the chimeras to the Lac repressor. Using this approach, we found surprising contributions from a small portion of the N-terminal tail and the CENP-A targeting domain in the initial recruitment of two essential constitutive centromere proteins, CENP-C and CENP-T. Our results indicate that the regions of CENP-A required for early events in centromere establishment differ from those that are required for maintaining centromere identity

How pension savings should be managed – active vs. passive management

Zarówno teoria finansów, jak i doświadczenia w zakresie funkcjonujących dotychczas produktów długoterminowego oszczędzania pozwalają stwierdzić, że kluczowe dla wartości oszczędności w długim okresie są koszty. Rekomenduje się, aby każda instytucja oferująca produkty emerytalne oferowała przynajmniej jeden fundusz pasywny, który umożliwi osiąganie rynkowej stopy zwrotu, nie pobierając przy tym wysokich opłat. Jest to szczególnie uzasadnione w sytuacji, gdy istotną część polskich funduszy inwestycyjnych stanowią potencjalni closet indexers, którzy inwestują w dużej mierze pasywnie, ale pobierają opłaty jak fundusze aktywne. Postuluje się ponadto zapewnienie transparentności wynagrodzeń zarządzających oszczędnościami emerytalnymi, a jako negatywny przykład podano produkty emerytalne w formie UFK. Zarządzający aktywami w ramach produktów emerytalnych powinni mieć możliwość pobierania jedynie opłaty za zarządzanie, której poziom byłby prawnie limitowany.We use experiences with long term saving products to draw conclusions on how the system of private pension savings should be designed. First and foremost, we highlight the costs charged by an asset manager as a crucial element of the system, which significantly influences the level of accumulated capital. Passive funds offer returns in line with the market return without charging high fees. Hence, we recommend that every institution entering the market of pension savings should be obliged to offer at least one passive fund. Especially in light of the fact that a significant part of Polish investment funds includes potential closet indexers, which are largely passively managed, but charge fees as if they were active. Another conclusion is that the structure of fees charged by asset managers has to be clear and transparent. Currently existing pension products in the form of unit linked insurance are a negative example of an opaque cost structure. Asset managers on the pension market should be allowed to charge only a management fee. Its level should be limited by appropriate regulations