141 research outputs found
A Catalog of Absorption Lines in Eight HST/STIS E230M 1.0 < z < 1.7 Quasar Spectra
We have produced a catalog of line identifications and equivalent width
measurements for all absorption features in eight ultraviolet echelle quasar
spectra. These spectra were selected as having the highest signal-to-noise
among the HST/STIS spectra obtained with the E230M grating. We identify 56
metal-line systems toward the eight quasars, and present plots of detected
transitions, aligned in velocity-space. We found that about 1/4 - 1/3 of the
features in the Lya forest region, redward of the incidence of the Lyb forest,
are metal lines. High ionization transitions are common. We see both O VI and C
IV in 88 - 90% of the metal-line systems for which the spectra cover the
expected wavelength. Si III is seen in 58%, while low ionization absorption in
C II, Si II, and/or Al II is detected in 50% of the systems for which they are
covered. This catalog will facilitate future studies of the Lya forest and of
metal-line systems of various types.Comment: 13 pages, 2 figures, submitted to Monthly Notices of the Royal
Astronomical Society, a complete version with the appendix and all figures is
available at http://www.astro.psu.edu/users/misawa/pub/Paper/qalcat.pdf.g
Third mission of the university ā basic differences in approaches
Tradicionalne i osnovne misije sveuÄiliÅ”ta, nastava i istraživanje sve se viÅ”e proÅ”iruju. TreÄa misija sveuÄiliÅ”ta je viÅ”edimenzionalan koncept koji poprima Å”iroke razmjere na svjetskom nivou. Kao cilj rada postavlja se prouÄavanje osnovnih sliÄnosti i razlika u pristupima treÄoj misiji sveuÄiliÅ”ta kada je rijeÄ o ameriÄkim u odnosu na europska sveuÄiliÅ”ta. Kao polazna osnova za usporedbu uzima se Äinjenica da treÄa misija sveuÄiliÅ”ta svoje porijeklo ima na ameriÄkom kontinentu dok se nastanak sveuÄiliÅ”ta vezuje za Europu. Cilj rada je konkretiziran na sljedeÄe zadatke: ispitati utjecaj globalnih obrazovnih politika na pristupe treÄoj misiji sveuÄiliÅ”ta; ispitati razlike u naÄinu funkcioniranja europskih u odnosu na ameriÄka sveuÄiliÅ”ta; objasniti obrazovne implikacije provedbe treÄe misije na europskim sveuÄiliÅ”tima. Kao zakljuÄak rada istiÄe se da je neophodno razumijevanje globalnih druÅ”tveno-ekonomskih utjecaja na proces visokog obrazovanja kako bi se sveobuhvatnije pristupilo obrazovnim reformama i naÄinima njihovog sprovoÄenja. TakoÄer, s obzirom na sudjelovanje sve brojnijih interesnih grupa u okviru realizacije treÄe misije sveuÄiliÅ”ta, neminovno je razvijanje stavova o vrijednostima i naÄelima treÄe misije kod svih onih koji su ukljuÄeni u proces visokog obrazovanja.The traditional and basic missions of the university, teaching and research are expanding. Terminology on the third mission of the university is gaining wide scope at the global level. The aim of this paper is to study basic similarities and differences in approach to the third mission of the university by comparing American to European universities. The starting point for comparing these approaches is the fact that the third mission of the university has its origins in the American continent, while the creation of the university is linked to Europe. The aim of this paper is to specify the following tasks: to examine the impact of global education policies on approaches to the third mission of the university; to examine the differences in the way European universities operate in relation to American universities; to explain the educational implications of the implementation of the universityās third mission at European universities. In conclusion, it is necessary to understand the global socioeconomic impacts on the process of higher education in order to approach educational reforms and ways of implementing them more comprehensively. Also, given the growing number of the participating interest groups in the implementation of the third mission of the university, it is inevitable to develop attitudes about the values and principles of the third mission among all those who are involved in the process of higher education
Measurement of the Ļ x BR(HāZZ*) at 350 GeV and 3 TeV center-of-mass energies CLIC
In this paper we present results of the determination of the statistical precision of the branching fraction measurement, for Higgs decaying to ā pairs at 3 TeV and 350 GeV CLIC. Measurements are simulated with the CLIC_ILD detector model, taking into consideration all relevant physics and beam-induced background processes. It is shown that the product of the branching fraction ( ā ā ) and the Higgs production cross-section can be measured with a relative statistical uncertainty of 3% (20%) at 3 TeV (350 GeV) center-of-mass energy, using semileptonic final states and assuming an integrated luminosity of 5 (1) abā1 .BPU11 : 11th International Conference of the Balkan Physical Union : Proceedings book; Aug 11 - Sep 1, 2022S05-HEP High Energy Physics (Particles and Fields
The Red Flour Beetle as a Model for Bacterial Oral Infections
Experimental infection systems are important for studying antagonistic interactions and coevolution between hosts and their pathogens. The red flour beetle Tribolium castaneum and the spore-forming bacterial insect pathogen Bacillus thuringiensis (Bt) are widely used and tractable model organisms. However, they have not been employed yet as an efficient experimental system to study host-pathogen interactions. We used a high throughput oral infection protocol to infect T. castaneum insects with coleopteran specific B. thuringiensis bv. tenebrionis (Btt) bacteria. We found that larval mortality depends on the dietary spore concentration and on the duration of exposure to the spores. Furthermore, differential susceptibility of larvae from different T. castaneum populations indicates that the host genetic background influences infection success. The recovery of high numbers of infectious spores from the cadavers indicates successful replication of bacteria in the host and suggests that Btt could establish infectious cycles in T. castaneum in nature. We were able to transfer plasmids from Btt to a non-pathogenic but genetically well-characterised Bt strain, which was thereafter able to successfully infect T. castaneum, suggesting that factors residing on the plasmids are important for the virulence of Btt. The availability of a genetically accessible strain will provide an ideal model for more in-depth analyses of pathogenicity factors during oral infections. Combined with the availability of the full genome sequence of T. castaneum, this system will enable analyses of host responses during infection, as well as addressing basic questions concerning host-parasite coevolution
Vaccinium myrtillus L. Leaf Waste as a Source of Biologically Potent Compounds: Optimization of Polyphenol Extractions, Chemical Profile, and Biological Properties of the Extracts
The aims of the present research include (1) optimization of extraction from Vaccinium myrtillus leaf waste via investigation of plant material:medium ratio, extraction medium, and extraction period, employing extractions at room and high temperatures, or using ultrasound and microwaves (M, HAE, UAE, and MAE, respectively), (2) physicochemical characterization, and (3) investigation of extract biological potential. The statistical analysis revealed that optimal levels of parameters for the greatest polyphenolic yield were a proportion of 1:30 g/mL, ethyl alcohol 50% (v/v) during 2 min of microwave irradiation. By LC-MS analysis, 29 phenolic components were detected; HAE showed the highest richness of almost all determined polyphenols, while chlorogenic acid and quercetin 3-O-glucuronide were dominant. All extracts showed a high inhibition of Staphylococcus aureus growth. The effect of different parameters on extractsā antioxidant capacity depended on the used tests. The extracts also showed a stimulative influence on keratinocyte viability and anti-inflammatory activity (proven in cell-based ELISA and erythrocyte stabilization assays). The extraction procedure significantly affected the extraction yield (MAE ā„ maceration ā„ UAE ā„ HAE), whereas conductivity, density, surface tension, and viscosity varied in a narrow range. The presented research provides evidence on the optimal extraction conditions and technique, chemical composition, and antioxidant, antimicrobial, anti-inflammatory, and keratinocyte viability properties of bilberry extracts for potential applications in pharmacy and cosmetics
Supplementary data for the article: IliÄ, I.; MilutinoviÄ-NikoliÄ, A.; MojoviÄ, Z.; VukoviÄ, Z.; VuliÄ, P.; GržetiÄ, I.; BankoviÄ, P.; JoviÄ-JoviÄiÄ, N. Oxidative Degradation of Aromatic N-Compounds Using Cobalt Containing Montmorillonite-Based Catalysts. Applied Clay Science 2020, 193, 105668. https://doi.org/10.1016/j.clay.2020.105668
Supplementary material for: [https://doi.org/10.1016/j.clay.2020.105668]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/4045
Makroporozni kopolimer na bazi glicidilmetakrilata funkcionalizovan sa dietilentriaminom kao sorbent tekstilne boje Reactive Black 5
In this paper, macroporous glycidyl methacrylate and ethylene glycol dimethacrylate copolymer functionalized with diethylene triamine (PGME-deta), was evaluated as Reactive Black 5 (RB5) sorbent. Batch RB5 removal from aqueous solution by PGME-deta was investigated by varying pH, contact time, sorbent dosage, initial dye concentration and temperature. The sorption is pH sensitive having maximum at pH 2 (dye removal of 85%), decreasing with the increase of pH (dye removal of 24% at pH 11) after 60 min. Sorption kinetics was fitted to chemical-reaction and particle-diffusion models (pseudo-first-, pseudo-second-order, intraparticle diffusion and Mckay models). The pseudo-second-order kinetic model accurately predicted the RB5 amount sorbed under all investigated operating conditions, while the intraparticle diffusion was the dominant rate-limiting mechanism. The diffusion mechanism was more prevalent with the decrease in temperature and the increase in concentration. The isotherm data was best fitted with the Langmuir model, indicating homogeneous distribution of active sites on PGME-deta and monolayer sorption, with the maximum sorption capacity of 353 mg g(-1). The calculated sorption rates improved with increasing temperature and an activation energy close to 40 kj mol(-1) was determined, suggesting that chemisorption was also rate-controlling.U okviru ovog rada ispitana je moguÄnost koriÅ”Äenja makroporoznog kopolimera glicidilmetakrilata i etilenglikoldimetakrilata funkcionalizovanog reakcijom otvaranja epoksidnih grupa sa dietilentriaminom (PGME-deta) kao sorbenta reaktivne tekstilne boje Reactive Black 5 (RB5). U Å”aržnim uslovima je ispitano uklanjanje RB5 iz vodenog rastvora pomoÄu PGME-deta, variranjem pH, vremena kontakta, mase sorbenta, poÄetne koncentracije boje i temperature. PGME-deta je pokazao afinitet za sorpciju RB5 zbog prisustva protonovanih amino grupa koje privlaÄe anjonske sulfonatne grupe u molekulu boje i moguÄnosti stvaranja vodoniÄnih veza izmeÄu sorbenta i sorbata. Kinetika sorpcije je analizirana pomoÄu Äetiri kinetiÄka modela (pseudo-prvog, pseudo-drugog reda, unutarÄestiÄne difuzije i Mekej) da bi se odredilo koji model najbolje opisuje sorpciju RB5. Zapažen je izrazit uticaj pH vrednosti na sorpciju RB5, sa maksimumom na pH 2 (pri Äemu je efikasnost uklanjanja boje 85%), i smanjenjem koliÄine sorbovane boje sa poveÄanjem pH (koliÄina uklonjene boje na pH 11 posle 60 min iznosi samo 24%). IzuÄavanjem kinetike sorpcije pokazalo se da sorpcija RB5 pomoÄu PGME-deta sledi kinetiÄki model pseudo-drugog reda (PSO), sugeriÅ”uÄi da je brzina sorpcije kontrolisana kapacitetom sorbenta i koncentracijom sorbata. Mehanizam procesa dominantno Äini unutarÄestiÄna difuzija, uz manji uticaj difuzije kroz film. Ovi mehanizmi difuzije su izraženiji pri nižim temperaturama i veÄim koncentracijama. Langmirov model najbolje opisuje ravnotežnu izotermu, ukazujuÄi na homogenu raspodelu aktivnih mesta na povrÅ”ini PGME-deta i monoslojnu sorpciju. Maksimalni sorpcioni kapacitet izraÄunat iz Langmirove izoterme iznosi 353 mg g-1. Zapaženo je da se brzina sorpcije poveÄava sa poveÄanjem temperature. IzraÄunata vrednost aktivacione energije od oko 40 kJ mol-1 potvrÄuje da se radi o procesu koji dominantno kontroliÅ”e hemisorpcija
The z = 0.0777 C III Absorber Towards PHL 1811 as a Case Study of a Low Redshift Weak Metal Line Absorber
We consider the physical conditions and origin of the z = 0.0777 absorption
system observed in C III, C II, Si III, C IV, O VI, and H I absorption along
the line of sight towards the quasar PHL 1811. We analysed the HST/STIS and
FUSE spectra of this quasar and compared the results to Cloudy photoionization
and collisional ionization models in order to derive densities, temperatures,
and metallicities of the absorbing gas. The absorption can be explained by two
C III clouds, offset by 35 km/s in velocity, with metallicities of ~one-tenth
the solar value. One cloud has a density of order n_H = 1.2 +0.9 -0.5 * 10^-3
cm^-3 (thickness 0.4 +0.3 -0.2 kpc) and produces the observed C II and Si III
absorption, while the other has a density of order n_H = 1.2 +0.9 -0.5 * 10^-5
cm^-3 (thickness 80 +70 -40 kpc) and gives rise to the observed weak C IV
absorption. Cloud temperatures are ~14,000 +3000 -2000 K and ~34,000 -4000
+2000 K for photoionized models. Although collisionally ionized clouds with T ~
70,000 K are possible, they are less likely because of the short cooling
time-scales involved. Previous studies revealed no luminous galaxy at the
absorber's redshift, so it is probably related to tidal debris, ejected
material, a dwarf galaxy, or other halo material in a galaxy group. Our models
also indicate that one of the two clouds would produce detectable weak Mg II
absorption if spectral coverage of that transition existed. We predict what the
system would look like at z ~ 1 when the ionizing background radiation was more
intense. We find that at z ~ 1 the denser component resembles a C IV absorber.
The second C III cloud in this z = 0.0777 absorber may be analogous to a subset
of the more diffuse O VI absorbers at higher redshift.Comment: 15 pages, 6 figures, accepted by MNRA
A Bare Molecular Cloud at z~0.45
Several neutral species (MgI, SiI, CaI, FeI) have been detected in a weak
MgII absorption line system (W_r(2796)~0.15 Angstroms) at z~0.45 along the
sightline toward HE0001-2340. These observations require extreme physical
conditions, as noted in D'Odorico (2007). We place further constraints on the
properties of this system by running a wide grid of photoionization models,
determining that the absorbing cloud that produces the neutral absorption is
extremely dense (~100-1000/cm^3), cold (<100 K), and has significant molecular
content (~72-94%). Structures of this size and temperature have been detected
in Milky Way CO surveys, and have been predicted in hydrodynamic simulations of
turbulent gas. In order to explain the observed line profiles in all neutral
and singly ionized chemical transitions, the lines must suffer from unresolved
saturation and/or the absorber must partially cover the broad emission line
region of the background quasar. In addition to this highly unusual cloud,
three other ordinary weak MgII clouds (within densities of ~0.005/cm^3 and
temperatures of ~10000K) lie within 500 km/s along the same sightline. We
suggest that the "bare molecular cloud", which appears to reside outside of a
galaxy disk, may have had in situ star formation and may evolve into an
ordinary weak MgII absorbing cloud.Comment: 15 pages, 4 figures, 4 tables, ApJ accepte
Infection routes matter in population-specific responses of the red flour beetle to the entomopathogen Bacillus thuringiensis
Background: Pathogens can infect their hosts through different routes. For studying the consequences for host resistance, we here used the entomopathogen Bacillus thuringiensis and the red flour beetle Tribolium castaneum for oral and systemic (i. e. pricking the cuticle) experimental infection. In order to characterize the molecular mechanisms underpinning the two different infection routes, the transcriptomes of beetles of two different T. castaneum populations ā one recently collected population (Cro1) and a commonly used laboratory strain (SB) ā were analyzed using a next generation RNA sequencing approach. Results: The genetically more diverse population Cro1 showed a significantly larger number of differentially expressed genes. While both populations exhibited similar reactions to pricking, their expression patterns in response to oral infection differed remarkably. In particular, the Cro1 population showed a strong response of cuticular proteins and developmental genes, which might indicate an adaptive developmental flexibility that was lost in the SB population presumably as a result of inbreeding. The immune response of SB was primarily based on antimicrobial peptides, while Cro1 relied on responses mediated by phenoloxidase and reactive oxygen species, which may explain the higher resistance of this strain against oral infection. Conclusions: Our data demonstrate that immunological and physiological processes underpinning the two different routes of infection are clearly distinct, and that host populations particularly differ in responses to oral infection. Furthermore, gene expression upon pricking infection entailed a strong signal of wounding, highlighting the importance of pricking controls in future infection studies
- ā¦