4,817 research outputs found

    Tame and wild theorem for the category of filtered by standard modules for a quasi-hereditary algebra

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    We introduce the notion of interlaced weak ditalgebras and apply reduction procedures to their module categories to prove the tame-wild dichotomy for the category F(Δ){\cal F}(\Delta) of filtered by standard modules for a quasi-hereditary algebra. Moreover, in the tame case, we show that given a fixed dimension dd, for every dd-dimensional indecomposable module M∈F(Δ)M \in {\cal F}(\Delta), with the only possible exception of those lying in a finite number of isomorphism classes, the module MM coincides with its Auslander-Reiten translate in F(Δ){\cal F}(\Delta). Our results are based on a theorem by Koenig, K\"ulshammer, and Ovsienko relating F(Δ){\cal F}(\Delta) with the module category of some special type of ditalgebra.Comment: 51 page

    Electron-Ion Recombination Rate Coefficients and Photoionization Cross Sections for Astrophysically Abundant Elements VI. Ni II

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    We present the first detailed ab initio quantum mechanical calculations for total and state-specific recombination rate coefficients for e + Ni III --> Ni II. These rates are obtained using a unified treatment for total electron-ion recombination that treats the nonresonant radiative recombination and the resonant dielectronic recombination in a self-consistent unified manner in the close coupling approximation. Large-scale calculations are carried out using a 49-state wavefunction expansion from core configurations 3d^8, 3d^74s, and 3d^64p that permits the inclusion of prominent dipole allowed core transitions. These extensive calculations for the recombination rates of Ni II required hundreds of CPU hours on the Cray T90. The total recombination rate coefficients are provided for a wide range of temperature. The state-specific recombination rates for 532 bound states of doublet and quartet symmetries, and the corresponding photoionization cross sections for leaving the core in the ground state, are presented. Present total recombination rate coefficients differ considerably from the currently used data in astrophysical models.Comment: ApJ Suppl. (submitted), 4 figure

    The Role of Late Antigen in CD4 Memory T Cell Formation during Influena [i.e. Influenza] Infection: A Dissertation

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    While memory CD4 T cells are critical for effective immunity to pathogens, the mechanisms underlying their generation are poorly defined. Although extensive work has been done to examine the role of antigen (Ag) in shaping memory formation, most studies focus on the requirements during the first few days of the response known as the priming phase. Little is known about whether or not Ag re-encounter by effector T cells (late Ag) alters CD4 memory T cell formation. Since influenza infection produces a large, heterogeneous, protective CD4 memory T cell population, I used this model to examine the role of late Ag in promoting CD4 memory T cell formation. In the experiments presented in this thesis, I demonstrate that late Ag is required to rescue responding CD4 T cells from default apoptosis and to program the transition to long-lived memory. Responding cells that failed to re-encounter Ag had decreased memory marker expression and failed to produce multiple cytokines upon re-stimulation. Ag recognition is required at a defined stage, as short-term Ag presentation provided 6 days after infection is able to restore canonical memory formation even in the absence of viral infection. Finally, I find that memory CD4 T cell formation following cold-adapted influenza vaccination is boosted when Ag is administered at this stage. These findings imply that persistence of viral Ag presentation into the effector phase is the key factor that determines the efficiency of memory generation. They also suggest that administering Ag during the effector stage may improve vaccine efficacy

    Building Character by Building Characters: A Literature Review Examining the Efficacy of Tabletop Roleplay as a Creative Intervention for Developing Social Skills in Adolescents

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    In the realm of tabletop roleplay games, Dungeons & Dragons (D&D) earned a reputation as the most prolific franchise within the genre and has since prevailed as a popular bonding activity for peer groups of all ages and backgrounds. Among the player base in the D&D community are those that gleaned its potential to offer a conducive space for personal growth, particularly in the realm of psychosocial development, given that D&D sessions facilitated dynamic social interactions among the members. The emphasis on imagination in D&D nurtures the tenets of intermodal expression, as players are encouraged to explore their creativity through the embodiment of their character in addition to engaging in the fictional play-space, which appeals to such concepts in expressive arts therapy as in expanding the range of play by decentering into an alternative reality or alternative world experience. This literature review desired to address the gap in literature analyzing D&D as a creative tool for social skills development, especially for adolescents who are in the process of cultivating their unique personalities. Recommendations for utilizing this method in a therapeutic setting were provided in addition to a fully conceptualized outline for a ten-week group curriculum which may act as a springboard for inspiring future endeavors in incorporating D&D roleplay with the selected population

    Discernment of Spirits in the Bible

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    In English, “to discern” basically means “to detect something that is obscure or concealed.” It also means “to perceive or recognize as being different or distinct; distinguish.” Hence, in ordinary usage, “discernment” has to do with “keenness of insight and judgment.

    Condition-based maintenance for a system subject to multiple degradation processes with stochastic arrival intensity

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    In this work, a system subject to different deterioration processes is analysed. The arrival of the degradation processes to the system is modelled using a shot-noise Cox process. The degradation processes grow according to an homogeneous gamma process. The system fails when a degradation process exceeds a failure threshold. The combined process of initiation and growth of the degradation processes is modelled and the system reliability is obtained. Heterogeneities are also integrated in the model assuming that the inverse of the scale parameter follows a uniform distribution. A maintenance strategy is implemented in this system and the state of the system is checked in inspection times. If the system is working at inspection time, a preventive replacement is performed if the deterioration level of a degradation process exceeds a certain threshold. A corrective replacement is performed if the system is down at inspection time. Under this maintenance strategy, the expected cost rate is obtained. Sensitivity analysis on the main parameters of the gamma process is performed.Comment: 30 pages, 10 figure

    Atomic Processes in Planetary Nebulae and H II Regions

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    Spectroscopic studies of Planetary Nebulae (PNe) and H {\sc ii} regions have driven much development in atomic physics. In the last few years the combination of a generation of powerful observatories, the development of ever more sophisticated spectral modeling codes, and large efforts on mass production of high quality atomic data have led to important progress in our understanding of the atomic spectra of such astronomical objects. In this paper I review such progress, including evaluations of atomic data by comparisons with nebular spectra, detection of spectral lines from most iron-peak elements and n-capture elements, observations of hyperfine emission lines and analysis of isotopic abundances, fluorescent processes, and new techniques for diagnosing physical conditions based on recombination spectra. The review is directed toward atomic physicists and spectroscopists trying to establish the current status of the atomic data and models and to know the main standing issues.Comment: 9 pages, 1 figur

    NMR spectroscopy and antioxidant activity of flavanones and flavones isolated from Chromolaena tacotana (Klatt) R.M. King & H. Rob.

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    Chromolaena tacotana is considered as a source of flavonoids. Here we examined the content and antioxidant properties of flavones and flavanones from the leaves of the plant. Four flavonoids, including (Cta) 5, 4' dihydroxy-7-methoxy flavanone, (Ctb) 3,5,3'-trihydroxy-7,4'-dimethoxyflavone; (Ctc), 3,4'-dihydroxy -5,7-dimethoxyflavanone; and (Ctd) 4'-hydroxy-5,7-dimethoxyflavanone, were isolated from leaves extracts, were identified by their NMR spectroscopic data, and then free radical scavenging activities of the flavonoids were assessed against DPPH. The antioxidant activity for the flavanone Ctb was the highest even compared to that of quercetin, with IC50 of 6.27 ÎŒg/mL and 8.67 ÎŒg/mL respectively. The flavanones Cta, Ctc and Ctd presented a lowest activity against free radicals as expected according to their molecular substituents and the position within the structure. Data obtained from this study support the ethnomedicinal use of the leaves of C. tacotana for an antioxidant purpose
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