Combinatorial Bounds for Conflict-free Coloring on Open Neighborhoods

In an undirected graph $G$, a conflict-free coloring with respect to open neighborhoods (denoted by CFON coloring) is an assignment of colors to the vertices such that every vertex has a uniquely colored vertex in its open neighborhood. The minimum number of colors required for a CFON coloring of $G$ is the CFON chromatic number of $G$, denoted by $\chi_{ON}(G)$. The decision problem that asks whether $\chi_{ON}(G) \leq k$ is NP-complete. We obtain the following results: * Bodlaender, Kolay and Pieterse [WADS 2019] showed the upper bound $\chi_{ON}(G)\leq {\sf fvs}(G)+3$, where ${\sf fvs}(G)$ denotes the size of a minimum feedback vertex set of $G$. We show the improved bound of $\chi_{ON}(G)\leq {\sf fvs}(G)+2$, which is tight, thereby answering an open question in the above paper. * We study the relation between $\chi_{ON}(G)$ and the pathwidth of the graph $G$, denoted ${\sf pw}(G)$. The above paper from WADS 2019 showed the upper bound $\chi_{ON}(G) \leq 2{\sf tw}(G)+1$ where ${\sf tw}(G)$ stands for the treewidth of $G$. This implies an upper bound of $\chi_{ON}(G) \leq 2{\sf pw}(G)+1$. We show an improved bound of $\chi_{ON}(G) \leq \lfloor \frac{5}{3}({\sf pw}(G)+1) \rfloor$. * We prove new bounds for $\chi_{ON}(G)$ with respect to the structural parameters neighborhood diversity and distance to cluster, improving existing results. * We also study the partial coloring variant of the CFON coloring problem, which allows vertices to be left uncolored. Let $\chi^*_{ON}(G)$ denote the minimum number of colors required to color $G$ as per this variant. Abel et. al. [SIDMA 2018] showed that $\chi^*_{ON}(G) \leq 8$ when $G$ is planar. They asked if fewer colors would suffice for planar graphs. We answer this question by showing that $\chi^*_{ON}(G) \leq 5$ for all planar $G$. All our bounds are a result of constructive algorithmic procedures.Comment: 30 page

LAGUNA in Polkowice-Sieroszowice mine in Poland

The Polkowice–Sieroszowice mine in one of the seven candidates for the future pan-European underground laboratory studied in the framework of the LAGUNA project. We review the evidence that from the point of view of geology, long-term plans for the mine and existing infrastructure, and support of the authorities this is a perfect place to host the 100 kton liquid argon detector GLACIER

Causes of mortality in laying hens in different housing systems in 2001 to 2004

<p>Abstract</p> <p>Background</p> <p>The husbandry systems for laying hens were changed in Sweden during the years 2001 – 2004, and an increase in the number of submissions for necropsy from laying hen farms was noted. Hence, this study was initiated to compare causes of mortality in different housing systems for commercial laying hens during this change.</p> <p>Methods</p> <p>Based on results from routine necropsies of 914 laying hens performed at the National Veterinary Institute (SVA) in Uppsala, Sweden between 2001 and 2004, a retrospective study on the occurrence of diseases and cannibalism, i.e., pecking leading to mortality, in different housing systems was carried out. Using the number of disease outbreaks in caged flocks as the baseline, the expected number of flocks with a certain category of disease in the other housing systems was estimated having regard to the total number of birds in the population. Whether the actual number of flocks significantly exceeded the expected number was determined using a Poisson distribution for the variance of the baseline number, a continuity correction and the exact value for the Poisson distribution function in Excel 2000.</p> <p>Results</p> <p>Common causes of mortality in necropsied laying hens included colibacillosis, erysipelas, coccidiosis, red mite infestation, lymphoid leukosis and cannibalism. Less common diagnoses were Newcastle Disease, pasteurellosis and botulism. Considering the size of the populations in the different housing systems, a larger proportion of laying hens than expected was submitted for necropsy from litter-based systems and free range production compared to hens in cages (<it>P </it>< 0.001). The study showed a significantly higher occurrence of bacterial and parasitic diseases and cannibalism in laying hens kept in litter-based housing systems and free-range systems than in hens kept in cages (<it>P </it>< 0.001). The occurrence of viral diseases was significantly higher in indoor litter-based housing systems than in cages (<it>P </it>< 0.001).</p> <p>Conclusion</p> <p>The results of the present study indicated that during 2001–2004 laying hens housed in litter-based housing systems, with or without access to outdoor areas, were at higher risk of infectious diseases and cannibalistic behaviour compared to laying hens in cages. Future research should focus on finding suitable prophylactic measures, including efficient biosecurity routines, to reduce the risk of infectious diseases and cannibalism in litter-based housing systems for laying hens.</p

Genome-wide screens identify Toxoplasma gondii determinants of parasite fitness in IFNγ-activated murine macrophages

Macrophages play an essential role in the early immune response against Toxoplasma and are the cell type preferentially infected by the parasite in vivo. Interferon gamma (IFNγ) elicits a variety of anti-Toxoplasma activities in macrophages. Using a genome-wide CRISPR screen we identify 353 Toxoplasma genes that determine parasite fitness in naїve or IFNγ-activated murine macrophages, seven of which are further confirmed. We show that one of these genes encodes dense granule protein GRA45, which has a chaperone-like domain, is critical for correct localization of GRAs into the PVM and secretion of GRA effectors into the host cytoplasm. Parasites lacking GRA45 are more susceptible to IFNγ-mediated growth inhibition and have reduced virulence in mice. Together, we identify and characterize an important chaperone-like GRA in Toxoplasma and provide a resource for the community to further explore the function of Toxoplasma genes that determine fitness in IFNγ-activated macrophages

Exchange Reactions between Alkanethiolates and Alkaneselenols on Au{111}

When alkanethiolate self-assembled monolayers on Au{111} are exchanged with alkaneselenols from solution, replacement of thiolates by selenols is rapid and complete, and is well described by perimeter-dependent island growth kinetics. The monolayer structures change as selenolate coverage increases, from being epitaxial and consistent with the initial thiolate structure to being characteristic of selenolate monolayer structures. At room temperature and at positive sample bias in scanning tunneling microscopy, the selenolate-gold attachment is labile, and molecules exchange positions with neighboring thiolates. The scanning tunneling microscope probe can be used to induce these place-exchange reactions

Charakterystyka mikrostruktury nadstopu Inconel 713C po badaniach pełzania

The main aim of this investigation was to determine the microstructural degradation of Inconel 713C superalloy during creep at high homologous temperature. The alloy in as cast condition was characterized by large microstructural heterogeneity. Inside equiaxed grains dendrite cores consisted of γ' precipitates surrounded by channels of matrix, whereas enrichment of interdendritic spaces in carbide formers, Zr and B resulted in the formation of additional constituents, namely M3B2, Ni7Zr2 and eutectic island γ/γ'. Directional coarsening of γ′ precipitates (rafting) under applied stress and decomposition of primary MC- type carbides accompanied by the formation of secondary carbides enriched in Cr and γ' phase was observed.Głównym celem badania było określenie degradacji mikrostruktury nadstopu Inconel 713C zachodzącej podczas badania pełzania w wysokiej temperaturze homologicznej. Badany nadstop bezpośrednio w stanie lanym charaktery- zuje się wysoką niejednorodnością mikrostrukturalną. Wewnątrz ziaren równoosiowych rdzenie dendrytów składają się z wydzieleń γ' otoczonych kanałami osnowy, natomiast wzbogacenie przestrzeni międzydendrytycznych w pier- wiastki węglikotwórcze, a także Zr i B, prowadzi do tworze- nia dodatkowych składników, mianowicie eutektyki γ/γ', wę- glików MC, borków M3B2 oraz fazy międzymetalicznej Ni7Zr2. W trakcie pełzania przy parametrach T = 982ºC i naprężeniu σ = 152 MPa zaobserwowano rafting typu N fazy międzymetalicznej γ'. W przestrzeniach międzydendrytycznych w wyniku częściowego rozpuszczenia węglików typu MC wydzieliły się węgliki M23C6 bogate w Cr

Sezonowe zmiany zawartości związków fenolowych w nadziemnych i podziemnych organach wiązówki bulwkowej (Filipendula vulgaris Moench)

The content and chemical composition of phenolic compounds in above- and underground organs of dropwort during second year of plant vegetation were studied. Five flavonoids (hyperosid, astragalin, spireaoside, kaempferol, quercetin), 2 catechin derivatives ((+)-catechin, (-)-epigallocatechin), and 7 polyphenolic acids (ellagic, gallic, syringic, salicylic, chlorogenic, caffeic and rosmarinic) were identified in aboveground organs. Their content, both in flowers and leaves, was significantly higher at the beginning of flowering as compared with full flowering stage. In underground organs (+)-catechin and its derivatives ((-)-epigallocatechin, (-)-epigallocatechin gallate, (-)-epicatechin) as well as 2 polyphenolic acids (ellagic and gallic) were identified. Their content was not closely related to the stage of plant development.Badano zawartość i skład chemiczny związków fenolowych w organach nadziemnych i podziemnych wiązówki bulwkowej w drugim roku uprawy. Pięć flawonoidów (hiperozyd, astragalina, spireozyd, kemferol i kwercetyna), 2 związki katechinowe ((-)-epigalokatechina i (+)-katechina) oraz 7 kwasów polifenolowych (elagowy, galusowy, syryngowy, salicylowy, chlorogenowy, kawowy i rozmarynowy) zidentyfikowano w organach nadziemnych. Zawartość tych związków zarówno w kwiatostanach, jak i w liściach była istotnie wyższa na początku kwitnienia niż podczas pełni kwitnienia roślin. W organach podziemnych zidentyfikowano natomiast (+)-katechinę i jej pochodne ((-)-epigalokatechinę, (-)-galusan epigalokatechiny i (-)-epikatechinę) oraz dwa kwasy fenolowe (galusowy i elagowy). Zawartość tych związków nie była ściśle związana z fazą rozwojową roślin