Optical characterization of nanocomposite polymer formed by ion implantation of boron

© 2017, Springer Science+Business Media New York.The boron-ion-implanted polymethylmethacrylate (B:PMMA) samples formed with an energy of 40 keV, ion doses ranging from 6.25 × 1014 to 2.5 × 1016 B+/cm2, and current density of 1016 B+/cm2) in the course of ion-induced carbonization are observed. The value of optical band gap energy of boron-ion-implanted layer Egopt,B was estimated given thickness of implanted layer as a maximum penetration depth of B+ ions into PMMA by slow positron beam spectroscopy in agreement with SRIM simulation results. On the basis of Egopt,B values, a number of carbon atoms in carbonaceous clusters N for the B:PMMA was calculated. It is found the existence of three regions of ion doses (1) 6.25 × 1014 ÷ 3.13 × 1015 B+/cm2, (2) 3.75 × 1015 ÷ 6.25 × 1015 B+/cm2, and (3) 1.25 × 1016 ÷ 2.5 × 1016 B+/cm2, showing thresholds in the estimated Egopt,B and N values as a function of ion dose for the B:PMMA studied. The ion-induced structural evolution towards formation of carbon nanostructures within these thresholds is suggested as explanation of experimental results, taking into account the possible carbonization in high-dose B:PMMA nanocomposite films

Exploring Continual Learning of Diffusion Models

Diffusion models have achieved remarkable success in generating high-quality images thanks to their novel training procedures applied to unprecedented amounts of data. However, training a diffusion model from scratch is computationally expensive. This highlights the need to investigate the possibility of training these models iteratively, reusing computation while the data distribution changes. In this study, we take the first step in this direction and evaluate the continual learning (CL) properties of diffusion models. We begin by benchmarking the most common CL methods applied to Denoising Diffusion Probabilistic Models (DDPMs), where we note the strong performance of the experience replay with the reduced rehearsal coefficient. Furthermore, we provide insights into the dynamics of forgetting, which exhibit diverse behavior across diffusion timesteps. We also uncover certain pitfalls of using the bits-per-dimension metric for evaluating CL

Physiological Response of Three Grapevine Cultivars Grown In North-Western Poland to Mycorrhizal Fungi

West Pomerania (Poland) is located near the northern boundary of the range of viticulture (the coldest zone A). Unfavourable weather conditions can pose a serious threat to the cultivated vines. One of the treatments used to increase the tolerance of plants to abiotic and biotic stresses is inoculation with symbiotic soil microorganisms. This paper focuses on the influence of mycorrhization on the changes in soil microbiology, the degree of colonization of roots by mycorrhizal fungi, and on selected physiologicalparameters of three grapevine cultivars (‘Pinot Noir’ on SO4 rootstock, ‘Regent’ on 5BB rootstock, and ‘Rondo’ on 125AA rootstock). The applied inoculation had a stimulating effect on the colonization of roots by arbuscular mycorrhizal (AM) fungi, as evidenced by higher mycorrhizal frequency and intensity in the mycorrhized plants. The mycorrhizal treatment increased the intensity of CO2 assimilation and transpiration. Mycorrhization reduced the efficiency of photosynthetic water use and increased stomatal conductance for water in the grapevines tested. The mycorrhizal treatment did not affect the concentration of assimilation pigments in vine leaves. The mycorrhization of grapevines had no effect on the values of initial fluorescence, maximum fluorescence, the maximum potential efficiency of photochemical reaction in PS II, the size of the pool of reduced electron acceptors in PS II, nor on the value of the PS II vitality index

Distinct Effects on Diversifying Selection by Two Mechanisms of Immunity Against Streptococcus pneumoniae

Antigenic variation to evade host immunity has long been assumed to be a driving force of diversifying selection in pathogens. Colonization by Streptococcus pneumoniae, which is central to the organism's transmission and therefore evolution, is limited by two arms of the immune system: antibody- and T cell- mediated immunity. In particular, the effector activity of CD4+ TH17 cell mediated immunity has been shown to act in trans, clearing co-colonizing pneumococci that do not bear the relevant antigen. It is thus unclear whether TH17 cell immunity allows benefit of antigenic variation and contributes to diversifying selection. Here we show that antigen-specific CD4+ TH17 cell immunity almost equally reduces colonization by both an antigen-positive strain and a co-colonized, antigen-negative strain in a mouse model of pneumococcal carriage, thus potentially minimizing the advantage of escape from this type of immunity. Using a proteomic screening approach, we identified a list of candidate human CD4+ TH17 cell antigens. Using this list and a previously published list of pneumococcal Antibody antigens, we bioinformatically assessed the signals of diversifying selection among the identified antigens compared to non-antigens. We found that Antibody antigen genes were significantly more likely to be under diversifying selection than the TH17 cell antigen genes, which were indistinguishable from non-antigens. Within the Antibody antigens, epitopes recognized by human antibodies showed stronger evidence of diversifying selection. Taken together, the data suggest that TH17 cell-mediated immunity, one form of T cell immunity that is important to limit carriage of antigen-positive pneumococcus, favors little diversifying selection in the targeted antigen. The results could provide new insight into pneumococcal vaccine design

Fragmentation in Peripheral Heavy-Ion Collisions: from Neck Emission to Spectator Decays

Invariant cross sections of intermediate mass fragments in peripheral collisions of Au on Au at incident energies between 40 and 150 AMeV have been measured with the 4-pi multi-detector INDRA. The maximum of the fragment production is located near mid-rapidity at the lower energies and moves gradually towards the projectile and target rapidities as the energy is increased. Schematic calculations within an extended Goldhaber model suggest that the observed cross-section distributions and their evolution with energy are predominantly the result of the clustering requirement for the emerging fragments and of their Coulomb repulsion from the projectile and target residues. The quantitative comparison with transverse energy spectra and fragment charge distributions emphasizes the role of hard scattered nucleons in the fragmentation process.Comment: 5 pages, 5 eps figures, RevTeX4, submitted to Phys. Lett.

Identification of pneumococcal colonization determinants in the stringent response pathway facilitated by genomic diversity

Background: Understanding genetic determinants of a microbial phenotype generally involves creating and comparing isogenic strains differing at the locus of interest, but the naturally existing genomic and phenotypic diversity of microbial populations has rarely been exploited. Here we report use of a diverse collection of 616 carriage isolates of Streptococcus pneumoniae and their genome sequences to help identify a novel determinant of pneumococcal colonization. Results: A spontaneously arising laboratory variant (SpnYL101) of a capsule-switched TIGR4 strain (TIGR4:19F) showed reduced ability to establish mouse nasal colonization and lower resistance to non-opsonic neutrophil-mediated killing in vitro, a phenotype correlated with in vivo success. Whole genome sequencing revealed 5 single nucleotide polymorphisms (SNPs) affecting 4 genes in SpnYL101 relative to its ancestor. To evaluate the effect of variation in each gene, we performed an in silico screen of 616 previously published genome sequences to identify pairs of closely-related, serotype-matched isolates that differ at the gene of interest, and compared their resistance to neutrophil-killing. This method allowed rapid examination of multiple candidate genes and found phenotypic differences apparently associated with variation in SP_1645, a RelA/ SpoT homolog (RSH) involved in the stringent response. To establish causality, the alleles corresponding to SP_1645 were switched between the TIGR4:19F and SpnYL101. The wild-type SP_1645 conferred higher resistance to neutrophil-killing and competitiveness in mouse colonization. Using a similar strategy, variation in another RSH gene (TIGR4 locus tag SP_1097) was found to alter resistance to neutrophil-killing. Conclusions: These results indicate that analysis of naturally existing genomic diversity complements traditional genetics approaches to accelerate genotype-phenotype analysis. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1573-6) contains supplementary material, which is available to authorized users

Statistical Multifragmentation of Non-Spherical Expanding Sources in Central Heavy-Ion Collisions

We study the anisotropy effects measured with INDRA at GSI in central collisions of Xe+Sn at 50 A.MeV and Au+Au at 60, 80, 100 A.MeV incident energy. The microcanonical multifragmentation model with non-spherical sources is used to simulate an incomplete shape relaxation of the multifragmenting system. This model is employed to interpret observed anisotropic distributions in the fragment size and mean kinetic energy. The data can be well reproduced if an expanding prolate source aligned along the beam direction is assumed. An either non-Hubblean or non-isotropic radial expansion is required to describe the fragment kinetic energies and their anisotropy. The qualitative similarity of the results for the studied reactions suggests that the concept of a longitudinally elongated freeze-out configuration is generally applicable for central collisions of heavy systems. The deformation decreases slightly with increasing beam energy.Comment: 35 pages, 19 figures, submitted to Nuclear Physics

Thermal and Chemical Freeze-out in Spectator Fragmentation

Isotope temperatures from double ratios of hydrogen, helium, lithium, beryllium, and carbon isotopic yields, and excited-state temperatures from yield ratios of particle-unstable resonances in 4He, 5Li, and 8Be, were determined for spectator fragmentation, following collisions of 197Au with targets ranging from C to Au at incident energies of 600 and 1000 MeV per nucleon. A deviation of the isotopic from the excited-state temperatures is observed which coincides with the transition from residue formation to multi-fragment production, suggesting a chemical freeze-out prior to thermal freeze-out in bulk disintegrations.Comment: 14 pages, 10 figures, submitted to Phys. Rev. C, small changes as suggested by the editors and referee

Fragment properties of fragmenting heavy nuclei produced in central and semi-peripheral collisions

Fragment properties of hot fragmenting sources of similar sizes produced in central and semi-peripheral collisions are compared in the excitation energy range 5-10 AMeV. For semi-peripheral collisions a method for selecting compact quasi-projectiles sources in velocity space similar to those of fused systems (central collisions) is proposed. The two major results are related to collective energy. The weak radial collective energy observed for quasi-projectile sources is shown to originate from thermal pressure only. The larger fragment multiplicity observed for fused systems and their more symmetric fragmentation are related to the extra radial collective energy due to expansion following a compression phase during central collisions. A first attempt to locate where the different sources break in the phase diagram is proposed.Comment: 23 pages submitted to NP

Viininmaistelun alkeet -tapahtuma Maria P:ssä

Tiivistelmä Tekijät: Paananen Riina ja Korkiakoski Merika Työn nimi: Viininmaistelun alkeet -tapahtuma Maria P:ssä Tutkintonimike: Restonomi (AMK), matkailun koulutus Asiasanat: tapahtuma, viini, viininmaistelu, Chile Opinnäytetyön tarkoituksena oli suunnitella ja järjestää Viininmaistelun alkeet -tapahtuma. Tapahtuman toimeksiantajana toimi kajaanilainen yritys Viinibaari Maria P. Tapahtuma haluttiin toteuttaa baarin imagoon sopivaksi. Opinnäytetyön tavoitteena oli saada Viini-baarille lisää asiakkaita tutustuttamalla kokemattomia viininmaistajia viineihin. Työ oli toiminnallinen opinnäytetyö, jonka tuotoksena oli Viininmaistelun alkeet -tapahtuma. Opinnäytetyöhön kerättiin teoriapohjaa viininmaistelusta sekä viinin ja ruoan yhdistämisestä, Chilestä viinimaana ja tapahtuman järjestämisestä. Näitä kaikkia käytettiin lopullisen tuotoksen valmistumiseen. Toteutuksen arviointina toimi tapahtumaan osallistuneilta saatu kirjallinen palaute. Palautteen mukaan kehittämistehtävän toteutuksessa onnistuttiin hyvin, sillä opinnäytetyön ennalta määritellyt tavoitteet saavutettiin. Opinnäytetyötä voidaan käyttää apuna jatkossa vastaavien tapahtumien suunnittelussa.Abstract Authors: Paananen Riina & Korkiakoski Merika Title of the Publication: Basics of wine tasting- event Degree title: Bachelor of Hospitality Management Keywords: event, wine, tasting, Chile The purpose for this thesis was to plan and arrange Basics of wine tasting –event. The commissioner for this thsesis was a local bar in Kajaani called Viinibaari Maria P. The event was planned to suit the imago of the bar. The objective of the thesis was to gain more customers to Viinibaari Maria P by introducing various wines to novice wine tasters. This research was a functional thesis which produced the Basics wine tasting event. The theory of this thesis focused on wine tasting, combining wine and food, Chile as a wine producer, and on planning and arranging an event. The feedback for the execution consists of the feedback forms that the customers of the event were asked to fill in. In addition observation method was used for evaluation. According to the feedback the event was successful because the objective of the thesis was reached. Our conclusion is that this thesis can be used as a guide in planning similar events