759 research outputs found
How Do Auditors Behave During Periods of Market Euphoria? The Case of Internet IPOs
The study of periods of market euphoria, such as Holland’s seventeenth-century tulip
mania, England’s eighteenth-century South Sea Company, America’s nineteenth-century
railroads, or, most recently, the U.S. housing market, is a topic of long-standing interest to economists. Theorists specify conditions under which market participants and institutions cause "bubbles" to arise and persist and empiricists test participant-centric or institution- centric explanations (Hong, Scheinkman, and Xiong 2008; Schultz 2008; Greenwood and Nagel 2009). In this paper, we study a different participant other than one that stands to gain from price fluctuations. We are interested in how auditors behave during periods of market euphoria. Given their gatekeeper responsibility to act in the public’s interest, along with the seeming inevitability of bubbles (Rampell 2009), it is important to study how auditors behave during euphoric market conditions. To address this question, we examine auditor going-concern (GC) opinions around the time of the wave of stressed Internet firms filing to go public on NASDAQ, the capital markets entry point for the companies that went on to constitute "dotcom mania"
Surface Gravities for 228 M, L, and T Dwarfs in the NIRSPEC Brown Dwarf Spectroscopic Survey
We combine 131 new medium-resolution (R~2000) J-band spectra of M, L, and T
dwarfs from the Keck NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) with 97
previously published BDSS spectra to study surface-gravity-sensitive indices
for 228 low-mass stars and brown dwarfs spanning spectral types M5-T9.
Specifically, we use an established set of spectral indices to determine
surface gravity classifications for all M6-L7 objects in our sample by
measuring equivalent widths (EW) of the K I lines at 1.1692, 1.1778, 1.2529 um,
and the 1.2 um FeHJ absorption index. Our results are consistent with previous
surface gravity measurements, showing a distinct double peak - at ~L5 and T5 -
in K I EW as a function of spectral type. We analyze K I EWs of 73 objects of
known ages and find a linear trend between log(Age) and EW. From this
relationship, we assign age ranges to the very low gravity, intermediate
gravity, and field gravity designations for spectral types M6-L0.
Interestingly, the ages probed by these designations remain broad, change with
spectral type, and depend on the gravity sensitive index used. Gravity
designations are useful indicators of the possibility of youth, but current
datasets cannot be used to provide a precise age estimate.Comment: 33 pages, 13 figures, ApJ in pres
The haunted delimitation of subjectivity in the Work of Nicolas Abraham
Kinesin-like calmodulin binding protein (KCBP), a Kinesin-14 family motor protein, is involved in the structural organization of microtubules during mitosis and trichome morphogenesis in plants. The molecular mechanism of microtubule bundling by KCBP remains unknown. KCBP binding to microtubules is regulated by Ca(2+)-binding proteins that recognize its C-terminal regulatory domain. In this work, we have discovered a new function of the regulatory domain. We present a crystal structure of an Arabidopsis KCBP fragment showing that the C-terminal regulatory domain forms a dimerization interface for KCBP. This dimerization site is distinct from the dimerization interface within the N-terminal domain. Side chains of hydrophobic residues of the calmodulin binding helix of the regulatory domain form the C-terminal dimerization interface. Biochemical experiments show that another segment of the regulatory domain located beyond the dimerization interface, its negatively charged coil, is unexpectedly and absolutely required to stabilize the dimers. The strong microtubule bundling properties of KCBP are unaffected by deletion of the C-terminal regulatory domain. The slow minus-end directed motility of KCBP is also unchanged in vitro. Although the C-terminal domain is not essential for microtubule bundling, we suggest that KCBP may use its two independent dimerization interfaces to support different types of bundled microtubule structures in cells. Two distinct dimerization sites may provide a mechanism for microtubule rearrangement in response to Ca(2+) signaling since Ca(2+)- binding proteins can disengage KCBP dimers dependent on its C-terminal dimerization interface
ARL3 mutations cause Joubert syndrome by disrupting ciliary protein composition
Joubert syndrome (JBTS) is a genetically heterogeneous autosomal recessive neurodevelopmental
ciliopathy. We investigated further the underlying genetic etiology of Joubert syndrome by studying
two unrelated families in whom JBTS was not associated with pathogenic variants in known JBTSrelated
genes. Combined autozygosity mapping of both families highlighted a candidate locus on
chromosome 10 (chr10: 101569997-109106128 (hg 19)), and exome sequencing revealed two
missense variants in ARL3 within the candidate locus. The encoded protein, ADP Ribosylation
Factor-Like GTPase 3, ARL3, is a small GTP-binding protein that is involved in directing lipid-modified
proteins into the cilium in a GTP-dependent manner. Both missense variants replace the highly
conserved Arg149 residue, which we show to be necessary for the interaction with its guanine
nucleotide exchange factor ARL13B, such that the mutant protein is associated with reduced INPP5E
and NPHP3 localisation in cilia. We propose that ARL3 provides a potential hub in the network of
encoded ciliopathy genes, whereby perturbation of ARL3 results in the mislocalisation of multiple
ciliary proteins due to abnormal displacement of lipidated protein cargo
Water Banks in the West
1 v. (in various pagings) : ill, maps. ; 28 cmhttps://scholar.law.colorado.edu/books_reports_studies/1059/thumbnail.jp
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