On the experimental evaluation of a Reich and Stivala computer algorithm by house et al

Reich, Leo; Stivala, Salvatore

doi:10.1016/0040-6031(88)87086-2

Cited by 9 publications

(14 citation statements)

References 3 publications

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“…Recent resolved observations -Adebahr et al (2012) recently presented resolved radio observations of M82 at frequencies 0.3 − 10 GHz, seperating the starburst region emission from a 'halo' component. In contrast to Williams & Bower (2010), Adebahr et al (2012) find an even flatter spectrum (ν −0.5 ) with no evidence of curvature. The overall flux level is systematically lower than the Williams & Bower (2010) spectrum, even at 5 GHz where the Williams & Bower (2010) beam is small enough to resolve the starburst.…”

Section: Data For M82's Radio Spectrumcontrasting

confidence: 92%

“…The starburst is viewed essentially edge-on from Earth. Unlike the other bright starburst, NGC 253 (Carilli 1996), a large fraction of the radio emission comes from the starburst itself rather than the host galaxy (Klein et al 1988;Basu et al 2012;Adebahr et al 2012). This is especially important at low frequencies, where galaxies are frequently unresolved: the starburst may be obscured by its own H II regions, but the host galaxy is likely to be unobscured down to < ∼ 10 MHz.…”

Section: Data For M82's Radio Spectrummentioning

confidence: 99%

“…One spans 22.5 MHz to 92 GHz where the starburst of M82 is unresolved. The other includes the data of Adebahr et al (2012) where the starburst region itself is resolved and with frequencies 330 MHz to 10 GHz; I add high frequency flux measurements at 20 -100 GHz to this data set.…”

Section: Data For M82's Radio Spectrummentioning

confidence: 99%

“…However, there has been relatively little work on the theory of the low frequency radio spectra of starburst galaxies. For model fitting, if free-free absorption is even considered at all, the typical assumption is the uniform slab model, in which both the free-free absorption and emission come from a uniform density ionized medium pervading the synchrotron-emitting region (for examples of uniform slabs used to fit starburst radio spectra, see, e.g., Sopp & Alexander 1991;Condon et al 1991;Carilli 1996;Torres 2004;Clemens et al 2010;Williams & Bower 2010;Adebahr et al 2012). The best current measurements are at GHz frequencies, where the integrated free-free absorption is often expected to be small and the details of the absorption may not matter much, although it has been claimed to be important at GHz frequencies in Arp 220 and other Ultraluminous Infrared Galaxies (ULIRGs) (Condon et al 1991;Sopp & Alexander 1991;Clemens et al 2008Clemens et al , 2010.…”

Section: Introductionmentioning

confidence: 99%

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Interpreting the low-frequency radio spectra of starburst galaxies: a pudding of Strömgren spheres

Lacki

2013

Monthly Notices of the Royal Astronomical Society

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The low frequency radio emission of starburst galaxies is informative, but it can be absorbed in several ways. Most importantly, starburst galaxies are home to many H II regions, whose free-free absorption blocks low frequency radio waves. These H II regions are discrete objects, but most multiwavelength models of starbursts assume a uniform medium of ionized gas, if they include the absorption at all. I calculate the effective absorption coefficient of H II regions in starbursts, which is ultimately a cross section times the density of H II regions. The cross sectionsare calculated by assuming that H II regions are Strömgren spheres. The coefficient asymptotes to a constant value at low frequencies, because H II regions partially cover the starburst, and are buried part way into the starburst's synchrotron emitting material. Considering Strömgren spheres around either OB stars or Super Star Clusters, I demonstrate the method by fitting to the low frequency radio spectrum of M82. I discuss implications of the results for synchrotron spectrum shape, H II region pressure, and free-free emission as a star-formation rate indicator. However, these results are preliminary, and could be affected by systematics. I argue that there is no volume-filling warm ionized medium in starbursts, and that H II regions may be the most important absorption process down to ∼ 10 MHz. Future data at low and high radio frequency will improve our knowledge of the ionized gas.

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Section: Data For M82's Radio Spectrumcontrasting

confidence: 92%

Section: Data For M82's Radio Spectrummentioning

confidence: 99%

Section: Data For M82's Radio Spectrummentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Interpreting the low-frequency radio spectra of starburst galaxies: a pudding of Strömgren spheres

Lacki

2013

Monthly Notices of the Royal Astronomical Society

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“…Viruses have evolved a variety of ways to overcome host defenses against infection, including abrogating IFN signaling pathways (27,28). KSHV itself possesses another protein, vIRF-1, to inhibit IFN-mediated transcription.…”

Section: Lymphoma Cells Infected Withmentioning

confidence: 99%

Viral IL-6-Induced Cell Proliferation and Immune Evasion of Interferon Activity

Chatterjee

Osborne

Bestetti

et al. 2002

Science

206

162

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Lymphoma cells infected with Kaposi's sarcoma-associated herpesvirus are autocrine dependent on virus-derived interleukin-6 (IL-6), but not on cellular IL-6. During viral infection, host cells induce the antiviral factor interferon (IFN) to up-regulate p21, initiate cell cycle arrest, and inhibit virus replication. Viral IL-6, however, blocks IFN signaling. A viral transcriptional program exists in which only the viral IL-6 gene is directly activated by IFN-alpha, allowing the virus to modify its cellular environment by sensing and responding to levels of intracellular IFN signaling. The human cytokine cannot mimic this effect because IFN-alpha down-regulates the IL-6 receptor, gp80. Viral IL-6 bypasses the gp80 regulatory checkpoint by binding directly to the gp130 transducer molecule, resulting in tumor cell autocrine dependence on the viral cytokine for proliferation and survival.

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Targeting B Cells and Microglia in Multiple Sclerosis With Bruton Tyrosine Kinase Inhibitors

2023

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ImportanceCurrently, disease-modifying therapies for multiple sclerosis (MS) use 4 mechanisms of action: immune modulation, suppressing immune cell proliferation, inhibiting immune cell migration, or cellular depletion. Over the last decades, the repertoire substantially increased because of the conceptual progress that not only T cells but also B cells play an important pathogenic role in MS, fostered by the empirical success of B cell–depleting antibodies against the surface molecule CD20. Notwithstanding this advance, a continuous absence of B cells may harbor safety risks, such as a decline in the endogenous production of immunoglobulins. Accordingly, novel B cell–directed MS therapies are in development, such as inhibitors targeting Bruton tyrosine kinase (BTK).ObservationsBTK is centrally involved in the B cell receptor–mediated activation of B cells, one key requirement in the development of autoreactive B cells, but also in the activation of myeloid cells, such as macrophages and microglia. Various compounds in development differ in their binding mode, selectivity and specificity, relative inhibitory concentration, and potential to enter the central nervous system. The latter may be important in assessing whether BTK inhibition is a promising strategy to control inflammatory circuits within the brain, the key process that is assumed to drive MS progression. Accordingly, clinical trials using BTK inhibitors are currently conducted in patients with relapsing-remitting MS as well as progressive MS, so far generating encouraging data regarding efficacy and safety.Conclusions and RelevanceWhile the novel approach of targeting BTK is highly promising, several questions remain unanswered, such as the long-term effects of using BTK inhibitors in the treatment of inflammatory CNS disease. Potential changes in circulating antibody levels should be evaluated and compared with B cell depletion. Also important is the potential of BTK inhibitors to enter the CNS, which depends on the given compound. Remaining questions involve where BTK inhibitors fit in the landscape of MS therapeutics. A comparative analysis of their distinct properties is necessary to identify which inhibitors may be used in relapsing vs progressive forms of MS as well as to clarify which agent may be most suitable for sequential use after anti-CD20 treatment.

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On the experimental evaluation of a Reich and Stivala computer algorithm by house et al

Cited by 9 publications

References 3 publications

Interpreting the low-frequency radio spectra of starburst galaxies: a pudding of Strömgren spheres

Interpreting the low-frequency radio spectra of starburst galaxies: a pudding of Strömgren spheres

Viral IL-6-Induced Cell Proliferation and Immune Evasion of Interferon Activity

Targeting B Cells and Microglia in Multiple Sclerosis With Bruton Tyrosine Kinase Inhibitors

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