861 research outputs found

    Differential Interleukin-2 Transcription Kinetics Render Mouse but Not Human T Cells Vulnerable to Splicing Inhibition Early after Activation

    Get PDF
    T cells are nodal players in the adaptive immune response against pathogens and malignant cells. Alternative splicing plays a crucial role in T cell activation, which is analyzed mainly at later time points upon stimulation. Here we have discovered a 2-h time window early after stimulation where optimal splicing efficiency or, more generally, gene expression efficiency is crucial for successful T cell activation. Reducing the splicing efficiency at 4 to 6 h poststimulation significantly impaired murine T cell activation, which was dependent on the expression dynamics of the Egr1-Nab2-interleukin-2 (IL-2) pathway. This time window overlaps the time of peak IL-2 de novo transcription, which, we suggest, represents a permissive time window in which decreased splicing (or transcription) efficiency reduces mature IL-2 production, thereby hampering murine T cell activation. Notably, the distinct expression kinetics of the Egr1-Nab2-IL-2 pathway between mouse and human render human T cells refractory to this vulnerability. We propose that the rational temporal modulation of splicing or transcription during peak de novo expression of key effectors can be used to fine-tune stimulation-dependent biological outcomes. Our data also show that critical consideration is required when extrapolating mouse data to the human system in basic and translational research

    Response to Open Peer Commentaries on "Diagnosis By Television Documentary: Professional Responsibilities in Informal Encounters".

    Get PDF
    In presenting the situation of a health professional witnessing an instance of misdiagnosis and mistreatment in a television documentary, we hoped to stimulate discussion of the professional responsibilities of health workers in informal encounters in a rapidly changing environment comprising print, television, and more recently social media platforms. The commentaries on our article do not disappoint in this respect, providing insightful and sometimes challenging reactions to the position we outlined in response to our original case. In our reply here, we choose to focus on two themes running through all of the commentaries: (1) the distinction between axiological and deontic perspectives invoked by Salloch, and the open-endedness of the former that we see as crucial in addressing the constantly changing media landscape through which health workers may confront medical need; and (2) the role of institutional, structural, and social factors in constraining or enabling virtuous professional practice—suggesting perhaps a further need for health workers to take action directly against structural injustices that prevent them from fulfilling their professional responsibilities

    Developmental stage-specific regulation of the circadian Clock by Temperature in Zebrafish

    Get PDF
    The circadian clock enables animals to adapt their physiology and behaviour in anticipation of the day-night cycle. Light and temperature represent two key environmental timing cues (zeitgebers) able to reset this mechanism and so maintain its synchronization with the environmental cycle. One key challenge is to unravel how the regulation of the clock by zeitgebers matures during early development. The zebrafish is an ideal model for studying circadian clock ontogeny since the process of development occurs ex utero in an optically transparent chorion and many tools are available for genetic analysis. However, the role played by temperature in regulating the clock during zebrafish development is poorly understood. Here, we have established a clock-regulated luciferase reporter transgenic zebrafish line (Tg (−3.1) per1b::luc) to study the effects of temperature on clock entrainment. We reveal that under complete darkness, from an early developmental stage onwards (48 to 72 hpf), exposure to temperature cycles is a prerequisite for the establishment of self-sustaining rhythms of zfper1b, zfaanat2, and zfirbp expression and also for circadian cell cycle rhythms. Furthermore, we show that following the 5–9 somite stage, the expression of zfper1b is regulated by acute temperature shifts

    Jewish Dimensions in Modern Visual Culture: Antisemitism, Assimilation, Affirmation

    Get PDF
    Gavriel Rosenfeld is a contributing author, “Postwar Jewish Architecture and the Memory of the Holocaust”, pp.285-302. Book description: A fascinating look at key aspects of visual culture in modern Jewish history In modern western history, the cultural and social developments of modernism have long been associated with Jews. Usually this has been a negative association: the perceived breakdown of traditional norms was blamed on Jewish influence in politics, society, and the arts. Throughout Europe, Jews were viewed as carriers of industrialized and cosmopolitan developments that threatened to undermine a cherished way of life. This anthology speaks to this issue through the lens of modernist visual production including paintings, posters, sculpture, and architecture. Essays by scholars from the U.S. and Israel confront the contradictory impulses that modernism’s interaction with Jewish culture provoked. Discussing how religion, class, race, and political alignments were used to provide attacks on modern art, the scholars also comment on visual responses to anti-semitism and the mainstream success of artists in the U.S. and Israel since World War II.https://digitalcommons.fairfield.edu/history-books/1013/thumbnail.jp

    Bandgap Change of Carbon Nanotubes: Effect of Small Tensile and Torsional Strain

    Full text link
    We use a simple picture based on the π\pi electron approximation to study the bandgap variation of carbon nanotubes with uniaxial and torsional strain. We find (i) that the magnitude of slope of bandgap versus strain has an almost universal behaviour that depends on the chiral angle, (ii) that the sign of slope depends on the value of (nm)mod3(n-m) \bmod 3 and (iii) a novel change in sign of the slope of bandgap versus uniaxial strain arising from a change in the value of the quantum number corresponding to the minimum bandgap. Four orbital calculations are also presented to show that the π\pi orbital results are valid.Comment: Revised. Method explained in detai

    Magnetic Boron Nitride Nanoribbons with Tunable Electronic Properties

    Full text link
    We present theoretical evidence, based on total-energy first-principles calculations, of the existence of spin-polarized states well localized at and extended along the edges of bare zigzag boron nitride nanoribbons. Our calculations predict that all the magnetic configurations studied in this work are thermally accessible at room temperature and present an energy gap. In particular, we show that the high spin state, with a magnetic moment of 1 μB\mu_B at each edge atom, presents a rich spectrum of electronic behaviors as it can be controlled by applying an external electric field in order to obtain metallic \leftrightarrow semiconducting \leftrightarrow half-metallic transitions.Comment: 12 pages, 5 figures, 2 table

    "Narrow" Graphene Nanoribbons Made Easier by Partial Hydrogenation

    Full text link
    It is a challenge to synthesize graphene nanoribbons (GNRs) with narrow widths and smooth edges in large scale. Our first principles study on the hydrogenation of GNRs shows that the hydrogenation starts from the edges of GNRs and proceeds gradually toward the middle of the GNRs so as to maximize the number of carbon-carbon π\pi-π\pi bonds. Furthermore, the partially hydrogenated wide GNRs have similar electronic and magnetic properties as those of narrow GNRs. Therefore, it is not necessary to directly produce narrow GNRs for realistic applications because partial hydrogenation could make wide GNRs "narrower"

    Screening of suitable cationic dopants for solar absorber material CZTS/Se: A first principles study

    Get PDF
    The earth abundant and non-toxic solar absorber material kesterite Cu2ZnSn(S/Se)(4) has been studied to achieve high power conversion efficiency beyond various limitations, such as secondary phases, antisite defects, band gap adjustment and microstructure. To alleviate these hurdles, we employed screening based approach to find suitable cationic dopant that can promote the current density and the theoretical maximum upper limit of the energy conversion efficiency (P(%)) of CZTS/Se solar devices. For this task, the hybrid functional (Heyd, Scuseria and Ernzerhof, HSE06) were used to study the electronic and optical properties of cation (Al, Sb, Ga, Ba) doped CZTS/Se. Our in-depth investigation reveals that the Sb atom is suitable dopant of CZTS/CZTSe and also it has comparable bulk modulus as of pure material. The optical absorption coefficient of Sb doped CZTS/Se is considerably larger than the pure materials because of easy formation of visible range exciton due to the presence of defect state below the Fermi level, which leads to an increase in the current density and P(%). Our results demonstrate that the lower formation energy, preferable energy gap and excellent optical absorption of the Sb doped CZTS/Se make it potential component for relatively high efficient solar cells

    Radiofrequency Electromagnetic Fields Cause Non-Temperature-Induced Physical and Biological Effects in Cancer Cells

    Get PDF
    Non-temperature-induced effects of radiofrequency electromagnetic fields (RF) have been controversial for decades. Here, we established measurement techniques to prove their existence by investigating energy deposition in tumor cells under RF exposure and upon adding amplitude modulation (AM) (AMRF). Using a preclinical device LabEHY-200 with a novel in vitro applicator, we analyzed the power deposition and system parameters for five human colorectal cancer cell lines and measured the apoptosis rates in vitro and tumor growth inhibition in vivo in comparison to water bath heating. We showed enhanced anticancer effects of RF and AMRF in vitro and in vivo and verified the non-temperature-induced origin of the effects. Furthermore, apoptotic enhancement by AM was correlated with cell membrane stiffness. Our findings not only provide a strategy to significantly enhance non-temperature-induced anticancer cell effects in vitro and in vivo but also provide a perspective for a potentially more effective tumor therapy
    corecore