A Neglected Argument in “The Will to Believe

In “The Will to Believe,” William James develops two distinct arguments for the legitimacy of holding a belief on what he calls unintellectual grounds. The first of these arguments (which I call the ‘indeterminacy argument’) attempts to distinguish between intellectual and unintellectual grounds as objective epistemological categories. The second argument (which I call the ‘subjective argument’) abandons that attempt and instead distinguishes between public and private, and subjectively intellectual and unintellectual reasons. Although these arguments differ, and both are present in “The Will to Believe,” the indeterminacy argument has received far more critical attention than the subjective argument. This disparity is unfortunate because the subjective argument presents a greater challenge to James’s opponents than does the indeterminacy argument. In this paper I will draw from “The Will to Believe” and other related works by James to outline both arguments. I will also criticize both to show why the subjective argument is more successful than the indeterminacy argument at proving James’s thesis

Long-Slit Observations of Extended C II 1335 Emission Around V854 Centauri and RY Sagittarii

We have obtained long-slit far-ultraviolet (1150--1730 A) spectra of the R Coronae Borealis (RCB) stars V854 Cen and RY Sgr, near maximum light and pulsational phase zero, with the Space Telescope Imaging Spectrograph (STIS) on Hubble Space Telescope (HST). The far-UV spectrum of each star shows a photospheric continuum rising steeply toward longer wavelengths, and a prominent emission feature at C II 1335. RY Sgr displays a second, but fainter, emission attributed to Cl I 1351 (which is radiatively fluoresced by C II 1335), but Cl I is weak or absent in V854 Cen. Most surprisingly, the C II emission of V854 Cen is significantly extended along the slit by +/- 2.5 arcsec, about 6 x 10^3 AU at the distance of the star. The C II feature of RY Sgr exhibits no such gross extension. Nevertheless, subtle broadenings of the C II emissions beyond the point response profile suggests inner clouds of radius \~0.1 arcsec (250 AU) around both stars. V854 Cen is only the third RCB star after R CrB and UW Cen known to have a resolved shell.Comment: 15 pages, 2 figures, (Figure 1 is a jpeg file), ApJ, in pres

Exposure to CO2 influences metabolism, calcification and gene expression of the thecosome pteropod Limacina retroversa

Author Posting. © The Company of Biologists, 2018. This article is posted here by permission of The Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 221 (2018): jeb164400, doi:10.1242/jeb.164400.Thecosomatous pteropods, a group of aragonite shell-bearing zooplankton, are becoming an important sentinel organism for understanding the influence of ocean acidification on pelagic organisms. These animals show vulnerability to changing carbonate chemistry conditions, are geographically widespread, and are both biogeochemically and trophically important. The objective of this study was to determine how increasing duration and severity of CO2 treatment influence the physiology of the thecosome Limacina retroversa, integrating both gene expression and organism-level (respiration and calcification) metrics. We exposed pteropods to over-saturated, near-saturated or under-saturated conditions and sampled individuals at 1, 3, 7, 14 and 21 days of exposure to test for the effect of duration. We found that calcification was affected by borderline and under-saturated conditions by week two, while respiration appeared to be more strongly influenced by an interaction between severity and duration of exposure, showing complex changes by one week of exposure. The organismal metrics were corroborated by specific gene expression responses, with increased expression of biomineralization-associated genes in the medium and high treatments throughout and complex changes in metabolic genes corresponding to both captivity and CO2 treatment. Genes associated with other physiological processes such as lipid metabolism, neural function and ion pumping had complex responses, influenced by both duration and severity. Beyond these responses, our findings detail the captivity effects for these pelagic organisms, providing information to contextualize the conclusions of previous studies, and emphasizing a need for better culturing protocols.Funding for this research was provided by a National Science Foundation grant to G.L.L., A.E.M. and A.M.T. (OCE-1316040). Additional support for field sampling was provided by theWoods Hole Oceanographic Institution, Coastal Ocean Institute and the Pickman Foundation.2019-02-1

Impact of the new solar abundances on the calibration of the PMS binary system RS Cha

Context: In a recent work, we tried to obtain a calibration of the two components of the pre-main sequence binary system RS Cha by means of theoretical stellar models. We found that the only way to reproduce the observational parameters of RS Cha with standard stellar models is to decrease the initial abundances of carbon and nitrogen derived from the GN93 solar mixture of heavy elements by a few tenths of dex. Aims: In this work, we aim to reproduce the observational properties of the RS Cha stars with stellar evolution models based on the new AGS05 solar mixture recently derived from a three-dimensional solar model atmosphere. The AGS05 mixture is depleted in carbon, nitrogen and oxygen with respect to the GN93 mixture. Methods: We calculated new stellar models of the RS Cha components using the AGS05 mixture and appropriate opacity tables. We sought models that simultaneously satisfy the observations of the two components (masses, radii, luminosities, effective temperatures and metallicity). Results: We find that it is possible to reproduce the observational data of the RS Cha stars with AGS05 models based on standard input physics. From these models, the initial helium content of the system is Y~0.255 and its age is ~9.13 +- 0.12 Myr.Comment: Research note accepted in A&A, 5 pages, 2 figure

Sequence Analysis of Alginate-Derived Oligosaccharides by Negative-Ion Electrospray Tandem Mass Spectrometry

Negative-ion electrospray tandem mass spectrometry (ES-MS/MS) with collision-induced dissociation (CID) is attempted for sequence determination of alginate oligosaccharides, derived from polyanionic alginic acid, polymannuronate, and polyguluronate by partial depolymerization using either alginate lyase or mild acid hydrolysis. Sixteen homo- and hetero-oligomeric fragments were obtained after fractionation by gel-filtration and strong anion exchange high performance liquid chromatography. The product-ion spectra of these alginate oligosaccharides were dominated by intense B-, C-, Y-, and Z-type ions together with 0,2A- and 2,5A-ions of lower intensities. Internal mannuronate residues (M) produce weak but specific decarboxylated Zint-ions (Zint − 44 Da; int: denotes internal), which can be used for distinction of M and a guluronate residue (G) at an internal position. A reducing terminal M or G, although neither gives rise to a specific ion, can be identified by differences in the intensity ratio of fragment ions of the reducing terminal residue [2,5Ared]/[0,4Ared] (red: denotes reducing terminal)

Transient Radio Lines from Axion Miniclusters and Axion Stars

Gravitationally bound clumps of dark matter axions in the form of 'miniclusters' or even denser 'axion stars' can generate strong radio signals through axion-photon conversion when encountering highly magnetised neutron star magnetospheres. We systematically study encounters of axion clumps with neutron stars and characterise the axion infall, conversion and the subsequent propagation of the photons. We show that the high density and low escape velocity of the axion clumps lead to strong, narrow, and temporally characteristic transient radio lines with an expected duration varying from seconds to months. Our work comprises the first end-to-end modeling pipeline capable of characterizing the radio signal generated during these transient encounters, quantifying the typical brightness, anisotropy, spectral width, and temporal evolution of the radio flux. The methods developed here may prove essential in developing dedicated radio searches for transient radio lines arising from miniclusters and axion stars.Comment: v2: Minor updates made to match published version. v1: 17 pages, 15 figure

Polyanionic Ligand Platforms for Methyl- and Dimethylaluminum Arrays

Trimethylaluminum finds widespread applications in chemical and materials synthesis, most prominently in its partially hydrolyzed form of methylalumoxane (MAO), which is used as a cocatalyst in the polymerization of olefins. This work investigates the sequential reactions of trimethylaluminum with hexaprotic phosphazenes (RNH)6P3N3 (=XH6) equipped with substituents R of varied steric bulk including tert-butyl (1H6), cyclohexyl (2H6), isopropyl (3H6), isobutyl (4H6), ethyl (5H6), propyl (6H6), methyl (7H6), and benzyl (8H6). Similar to MAO, the resulting complexes of polyanionic phosphazenates [XHn]n−6 accommodate multinuclear arrays of [AlMe2]+ and [AlMe]2+. Reactions were monitored by 31P NMR spectroscopy, and structures were determined by single-crystal X-ray diffraction. They included 1H4(AlMe2)2, 1H3(AlMe2)3, 2H3(AlMe2)3, 3(AlMe2)4AlMe, 4H­(AlMe2)5, 4(AlMe2)6, {5H­(AlMe2)4}2AlMe, 5(AlMe2)6, 6(AlMe2)6, {7(AlMe2)4AlMe}2, and 8(AlMe2)6. The study shows that subtle variations of the steric properties of the R groups influence the reaction pathways, levels of aggregation, and fluxional behavior. While [AlMe2]+ is the primary product of the metalation, [AlMe]2+ is utilized to alleviate overcrowding or to aid aggregation. At the later stages of metalation, [AlMe2]+ groups start to scramble around congested sites. The ligands proved to be very robust and extremely flexible, offering a unique platform to study complex multinuclear metal arrangements

Spectropolarimetry of R Coronae Borealis in 1998--2003: Discovery of Transient Polarization at Maximum Brightness

We present an extended optical spectropolarimetry of R CrB from 1998 January to 2003 September. The polarization was almost constant in the phase of maximum brightness, being consistent with past observations. We detected, however, temporal changes of polarization ($\sim 0.5$ %) in 2001 March and August, which were the first detection of large polarization variability in R CrB near maximum brightness. The amplitude and the position angle of the `transient polarization' were almost constant with wavelength in both two events. There was a difference by about 20 degrees in the position angle between the two events. Each event could be explained by light scattering due to short-lived dust puff occasionally ejected off the line of sight. The flatness of the polarization against the wavelength suggests that the scatterer is a mixture of dust grains having various sizes. The rapid growth and fading of the transient polarization favors the phenomenological model of dust formation near the stellar photosphere (e.g., within two stellar radii) proposed for the time evolution of brightness and chromospheric emission lines during deeply declining periods, although the fading timescale can hardly be explained by a simple dispersal of expanding dust puff with a velocity of $\sim 200-350$ km s $^{-1}$. Higher expansion velocity or some mechanism to destroy the dust grains should be needed.Comment: 22 pages, 10 figures, accepted for publication in A

The fall and rise of V854 Centauri: long-term ultraviolet spectroscopy of a highly-active R Coronae Borealis star

We examine long-term low-dispersion IUE, SWP and LWP spectroscopy of the R Coronae Borealis (RCB) star V854 Cen, obtained across the deep 1991, 1992-1993 and 1994 declines. We also report the optical light curve for the star in the interval 1987-1998, including multi-color photometry obtained during 1989-1998. Analysis of the UV emission line spectra indicates most lines decay during the deep declines on characteristic timescales comparable to that reported for optical features. Fe, Mg and neutral C lines decay on timescales of typically 50-100 d. Other lines, notably ionized C lines, decay on longer timescales (> 200 d) or appear to be unaffected by the declines. The general nature of the UV emission lines and other UV features during the declines is consistent with the E1/E2/BL line-region model developed from the behavior of optical spectral features during declines. However, the detailed line-behavior indicates large intrinsic variability between decline events inconsistent with the simple E1/E2/BL model. Limited temporal coverage prevents detailed examination of the geometry of the emission line region or the obscuring dust. We also report the first detection of the transition-region line C IV 1550 in the spectrum of an RCB star.Comment: AJ in press (June), 7 figures, 4 table