Particle module of Piernik MHD code

Piernik is a multi-fluid grid magnetohydrodynamic (MHD) code based on the Relaxing Total Variation Diminishing (RTVD) conservative scheme. The original code has been extended by addition of dust described within the particle approximation. The dust is now described as a system of interacting particles. The particles can interact with gas, which is described as a fluid. The comparison between the test problem results and the results coming from fluid simulations made with Piernik code shows the most important differences between fluid and particle approximations used to describe dynamical evolution of dust under astrophysical conditions.Comment: 4 pages, submitted to the Proceedings of the 17'th Young Scientists' Conference on Astronomy and Space Physics (April 26 - May 1, 2010 Kyiv, Ukraine

Comparison between particle and fluid approximations to dust dynamics

We present a new particle module of the magnetohydrodynamic (MHD) Piernik code. The original multi-fluid grid code based on the Relaxing Total Variation Diminishing (RTVD) scheme has been extended by addition of dust described within the particle approximation. The dust is now described as a system of interacting particles. The particles can interact with gas, which is described as a fluid. In this poster we introduce the scheme used to solve equations of motion for the particles and present the first results coming from the module. The results of test problems are also compared with the results coming from fluid simulations made with Piernik-MHD code. The comparison shows the most important differences between fluid and particle approximations used to describe dynamical evolution of dust under astrophysical conditions.Comment: 2 pages, submitted to the Proceedings of the International Conference of Young Astronomers (September 7-13, 2009 Krak\'ow, Poland

Nakrycia głowy biskupów przemyskich z archikatedry pw. Jana Chrzciciela i Wniebowzięcia Najświętszej Maryi Panny

The article presents the headdress found during the research conducted in 2012–2015 in the crypts of the Przemyśl archcathedral. They were furnishings ofburials of ordinary and suffragan bishops. There were analysed mitres, which are an important part of the pontifical attire, and calottes, which are not liturgical vestments. Both headdresses are exceptional finds because they are found relatively rarely during archaeological research. Although they are headdress typical of bishops,they differ significantly in form and purpose, which was demonstrated in the article. Based on written sources, the mitre was presented in a broader symbolic and culturalcontext, recalling the prayers that were said during the consecration and during preparation for the pontifical mass, when the mitre was placed on the bishop’s head.Its appearance was discussed, paying attention to the characteristic features of the cut and finish, which made it possible to distinguish mitre: pretiosa, auriphrygiataand simplex. The way of wearing it was also indicated and the changes in its form observed over the centuries. The article also highlights the modifications in the appearanceof the calotte. The Przemyśl finds allowed to capture various forms of this headdress and the transition stage between the calotte typical of the 16th century anda fully shaped one made of several equal wedges.W artykule zaprezentowano nakrycia głowy wydobyte podczas badań w kryptach grobowych archikatedry przemyskiej. Stanowiły one wyposażenie pochówków biskupów ordynariuszy i sufraganów. Analizie poddano mirty, będące ważną częścią stroju pontyfikalnego i kalotki, które nie są szatą liturgiczną. Zwrócono uwagę na charakterystyczne cechy ich kroju i wykończenia. Na podstawie źródeł pisanych zaprezentowano je w szerszym kontekście symboliczno–kulturowym, zwracając uwagę na odmienną funkcję, jaką pełniły oba nakrycia głowy

Kościół w świecie mediów. Ewangelizacja w dobie komputerów

Kirche in Medienwelt. Evangeliesierung in die Zeit der Computern XXI Jahrhundert zeigt uns eine gewaltige Entwicklung der Massenmedien und ihren Einfluss auf die Unwelt und das Leben eines Menschen. In einer so ausgebildeten Welt soll die Kirche diesen Einfluss der Massenmedien ausnutzen, um Ihr Evangelisationswerk zu fuhren. Vorliegender Artikel gibt uns eine kurze Reflexion zum Thema der Teilnahme der Kirche an die Welt der Massenmedien und der Teilnahme der Massenmedien an den Kirchendienst.  

Microbiological Hazards Associated with Archaeological Works, Illustrated with an Example of Fredro Crypt (Przemyśl, Poland)

The human remains and other materials found in crypts can be highly contaminated with microorganisms. Archaeologists are exposed to microorganisms in many ways (e.g by inhaling dust, contaminating scratches or cuts). We aimed at evaluating microbial hazards associated with human remains and bioaerosols formed during archaeological works in burial crypts. The samples of the human remains, bioaerosols and personal protective equipment (dust respirators, disposable coveralls) were collected during archaeological works in the vault of the Cathedral Basilica of St. John the Baptist and the Assumption of the Blessed Virgin Mary in Przemyśl (Fredro crypt). The microbiological examination involved determining the number of spores of aerobic and anaerobic bacteria, the number of mesophilic and hemolytic bacteria, and the number of xerophilic, non- xerophilic and keratinolytic fungi. The air as well as objects and materials found in crypts are highly contaminated with bacteria and fungi. The xerophilic fungi were the most numerous in all samples of human remains 1–230·103 cfu(colony forming units/g). The non-xerophilic fungi were predominant in bioaerosols (>104 cfu/m3 during archaeological works). The majority of bacterial strains (81.3%) belonged to the genus Bacillus. Fungi belonging to the genera Penicillium (65.2%) and Aspergillus (28.6%) dominated among the isolated fungi. Fogging sterilization of the crypt turned out to be ineffective. The high number of microorganisms both in the air and on human remains indicates that there is a need for particular caution during archaeological works which cause dust emission. In order to reduce exposure to harmful biological factors, the use of disposable personal protective equipment seems necessary

Rapid Formation of Massive Planetary Cores in a Pressure Bump

Models of planetary core growth by either planetesimal or pebble accretion are traditionally disconnected from the models of dust evolution and formation of the first gravitationally-bound planetesimals. The state-of-the-art models typically start with massive planetary cores already present. We aim to study the formation and growth of planetary cores in a pressure bump, motivated by the annular structures observed in protoplanetary disks, starting with sub-micron-sized dust grains. We connect the models of dust coagulation and drift, planetesimal formation in the streaming instability, gravitational interactions between planetesimals, pebble accretion, and planet migration, into one uniform framework. We find that planetesimals forming early at the massive end of the size distribution grow quickly dominantly by pebble accretion. These few massive bodies grow on the timescales of ~100 000 years and stir the planetesimals formed later preventing the emergence of further planetary cores. Additionally, a migration trap occurs allowing for retention of the growing cores. Pressure bumps are favourable locations for the emergence and rapid growth of planetary cores by pebble accretion as the dust density and grain size are increased and the pebble accretion onset mass is reduced compared to a smooth-disk model.Comment: 15 pages, 11 figures, accepted by A&

SKI complex: A multifaceted cytoplasmic RNA exosome cofactor in mRNA metabolism with links to disease, developmental processes, and antiviral responses

RNA stability and quality control are integral parts of gene expression regulation. A key factor shaping eukaryotic transcriptomes, mainly via 30–50 exoribonucleolytic trimming or degradation of diverse transcripts in nuclear and cytoplasmic compartments, is the RNA exosome. Precise exosome targeting to various RNA molecules requires strict collaboration with specialized auxiliary factors, which facilitate interactions with its substrates. The predominant class of cytoplasmic RNA targeted by the exosome are protein-coding transcripts, which are carefully scrutinized for errors during translation. Normal, functional mRNAs are turned over following protein synthesis by the exosome or by Xrn1 50–30-exonuclease, acting in concert with Dcp1/2 decapping complex. In turn, aberrant transcripts are eliminated by dedicated surveillance pathways, triggered whenever ribosome translocation is impaired. Cytoplasmic 30–50 mRNA decay and surveillance are dependent on the tight cooperation between the exosome and its evolutionary conserved co-factor— the SKI (superkiller) complex (SKIc). Here, we summarize recent findings from structural, biochemical, and functional studies of SKIc roles in controlling cytoplasmic RNA metabolism, including links to various cellular processes. Mechanism of SKIc action is illuminated by presentation of its spatial structure and details of its interactions with exosome and ribosome. Furthermore, contribution of SKIc and exosome to various mRNA decay pathways, usually converging on recycling of ribosomal subunits, is delineated. A crucial physiological role of SKIc is emphasized by describing association between its dysfunction and devastating human disease—a trichohepatoenteric syndrome (THES). Eventually, we discuss SKIc functions in the regulation of antiviral defense systems, cell signaling and developmental transitions, emerging from interdisciplinary investigations

Origin of isotopic diversity among carbonaceous chondrites

Carbonaceous chondrites are some of the most primitive meteorites and derive from planetesimals that formed a few million years after the beginning of the solar system. Here, using new and previously published Cr, Ti, and Te isotopic data, we show that carbonaceous chondrites exhibit correlated isotopic variations that can be accounted for by mixing among three major constituents having distinct isotopic compositions, namely refractory inclusions, chondrules, and CI chondrite-like matrix. The abundances of refractory inclusions and chondrules are coupled and systematically decrease with increasing amount of matrix. We propose that these correlated abundance variations reflect trapping of chondrule precursors, including refractory inclusions, in a pressure maximum in the disk, which is likely related to the water ice line and the ultimate formation location of Jupiter. The variable abundance of refractory inclusions/chondrules relative to matrix is the result of their distinct aerodynamical properties resulting in differential delivery rates and their preferential incorporation into chondrite parent bodies during the streaming instability, consistent with the early formation of matrix-poor and the later accretion of matrix-rich carbonaceous chondrites. Our results suggest that chondrules formed locally from isotopically heterogeneous dust aggregates which themselves derive from a wide area of the disk, implying that dust enrichment in a pressure trap was an important step to facilitate the accretion of carbonaceous chondrite parent bodies or, more generally, planetesimals in the outer solar system.Comment: 12 pages, 4 figures, 1 table. Accepted for publication in ApJ