60,593 research outputs found
1947 Congratulations Card
A card reading Congratulations to Louis-Philippe Gagné with a hand-written message. Signed M. Pàllet .https://digitalcommons.usm.maine.edu/fac-lpg-1947-01-03/1028/thumbnail.jp
02/10/1949 Letter from Charles P. Nelson
Letter from Maine Congressman Charles P. Nelson, M. C., to Louis-Philippe Gagné regarding Cardinal József Mindszenty.https://digitalcommons.usm.maine.edu/fac-lpg-letters-1949/1004/thumbnail.jp
11/04/1947 Letter from the Lewiston Fire Department
Letter from R. M. Thomas, D. C., Chairman of the Lewiston Fire Department, to Louis-Philippe Gagné. This letter is related to the Great Fires of 1947.https://digitalcommons.usm.maine.edu/fac-lpg-1947-10-12/1026/thumbnail.jp
No Transition Disk? Infrared Excess, PAH, H-2, And X-Rays From The Weak-Lined T Tauri Star DoAr 21
As part of a program to understand disk dispersal and the interplay between circumstellar disks and X-ray emission, we present new high-resolution mid-infrared (IR) imaging, high-resolution optical spectroscopy, and Chandra grating X-ray spectroscopy of the weak-lined T Tauri star DoAr 21. DoAr 21 (age \u3c 10(6) yr and mass similar to 2.2M(circle dot) based on evolutionary tracks) is a strong X-ray emitter, with conflicting evidence in the literature about its disk properties. It shows weak but broad H alpha emission (reported here for the first time since the 1950s); polarimetric variability; polycyclic aromatic hydrocarbon (PAH) and H-2 emission; and a strong, spatially resolved 24 mu m excess in archival Spitzer photometry. Gemini sub-arcsecond-resolution 9-18 mu m images show that there is little or no excess mid-IR emission within 100 AU of the star; the excess emission is extended over several arcseconds and is quite asymmetric. The extended emission is bright in the ultraviolet (UV)-excited lambda = 11.3 mu m PAH emission feature. A new high-resolution X-ray grating spectrum from Chandra shows that the stellar X-ray emission is very hard and dominated by continuum emission; it is well fit by a multi-temperature thermal model, typical of hard coronal sources, and shows no evidence of unusually high densities. A flare during the X-ray observation shows a temperature approaching 10(8) K. We argue that the far-UV emission from the transition region is sufficient to excite the observed extended PAH and continuum emission, and that the H-2 emission may be similarly extended and excited. While this extended emission may be a disk in the final stages of clearing, it also could be more akin to a small-scale photodissociation region than a protoplanetary disk, highlighting both the very young ages (\u3c10(6) yr) at which some stars are found without disks and the extreme radiation environment around even late-type pre-main-sequence stars
Do CEOs Exercise Their Stock Options Earlier than Other Executives?
This paper looks at the timing chosen by CEOs to exercise their stock options and to sell their shares of stock compared to the timing chosen by other top executives in the firm. We first present a model that predicts when CEOs should exercise their options and/or sell their shares, and when other top managers should. Using a tournament approach we find that other top executives should exercise their stock options later than the CEO. We test this model using an unique data set of Canadian companies from 1993 onward. Our results seem to support the theoretical model as non-CEO executives seem to exercise their stock options about a calendar year later than the CEO. Moreover, non-CEO executive a more likely to exercise when a new CEO has been appointed, confirming our tournament model results. Nous étudions dans cet article le moment choisi par le PDG d'une compagnie pour lever ses options ou vendre ses actions dans la compagnie comparativement au moment choisi par les autres hauts dirigeants de la compagnie. Nous présentons premièrement un modèle théorique de tournoi qui fait des prédictions quant au moment opportun pour le PDG et les autres dirigeants de lever leurs options et/ou de vendre leurs actions dans la compagnie. Nous montrons théoriquement dans un tel modèle de tournoi que les hauts dirigeants devraient lever leurs options après le PDG. Nous testons ce modèle en utilisant une base de données unique de compagnies canadiennes de 1993 à 1999. Nos résultats empiriques semblent supporter notre modèle théorique puisque les hauts dirigeants semblent lever leurs options un an plus tard que le PDG. De plus, les hauts dirigeants semblent plus enclins à lever leurs options lorsqu'un nouveau PDG vient d'être nommé, confirmant ainsi notre modèle de tournoi.CEO and Executive Compensation, Options, Timing of Exercised Options., Contributions volontaires, pertes publiques, risque, ambiguïté, données expérimentales
Brown Dwarfs in Young Moving Groups from Pan-STARRS1. I. AB Doradus
Substellar members of young (150 Myr) moving groups are valuable
benchmarks to empirically define brown dwarf evolution with age and to study
the low-mass end of the initial mass function. We have combined Pan-STARRS1
(PS1) proper motions with opticalIR photometry from PS1, 2MASS and
to search for substellar members of the AB Dor Moving Group
within 50 pc and with spectral types of late-M to early-L,
corresponding to masses down to 30 M at the age of the group
(125 Myr). Including both photometry and proper motions allows us to
better select candidates by excluding field dwarfs whose colors are similar to
young AB~Dor Moving Group members. Our near-IR spectroscopy has identified six
ultracool dwarfs (M6L4; 30100 M) with intermediate
surface gravities (INT-G) as candidate members of the AB Dor Moving Group. We
find another two candidate members with spectra showing hints of youth but
consistent with field gravities. We also find four field brown dwarfs
unassociated with the AB Dor Moving Group, three of which have INT-G gravity
classification. While signatures of youth are present in the spectra of our
125 Myr objects, neither their nor colors are
significantly redder than field dwarfs with the same spectral types, unlike
younger ultracool dwarfs. We also determined PS1 parallaxes for eight of our
candidates and one previously identified AB Dor Moving Group candidate.
Although radial velocities (and parallaxes, for some) are still needed to fully
assess membership, these new objects provide valuable insight into the spectral
characteristics and evolution of young brown dwarfs.Comment: ApJ, accepte
02/20/1947 New Orleans Postcard
Postcard to Louis-Philippe Gagné from New Orleans, Louisiana, signed by M. M. Gagnéhttps://digitalcommons.usm.maine.edu/fac-lpg-1947-04-06/1020/thumbnail.jp
The Coolest Isolated Brown Dwarf Candidate Member of TWA
We present two new late-type brown dwarf candidate members of the TW Hydrae
association (TWA) : 2MASS J12074836-3900043 and 2MASS J12474428-3816464, which
were found as part of the BANYAN all-sky survey (BASS) for brown dwarf members
to nearby young associations. We obtained near-infrared (NIR) spectroscopy for
both objects (NIR spectral types are respectively L1 and M9), as well as
optical spectroscopy for J1207-3900 (optical spectral type is L0{\gamma}), and
show that both display clear signs of low-gravity, and thus youth. We use the
BANYAN II Bayesian inference tool to show that both objects are candidate
members to TWA with a very low probability of being field contaminants,
although the kinematics of J1247-3816 seem slightly at odds with that of other
TWA members. J1207-3900 is currently the latest-type and the only isolated
L-type candidate member of TWA. Measuring the distance and radial velocity of
both objects is still required to claim them as bona fide members. Such
late-type objects are predicted to have masses down to 11-15 MJup at the age of
TWA, which makes them compelling targets to study atmospheric properties in a
regime similar to that of currently known imaged extrasolar planets.Comment: 8 pages, 4 figures, accepted for publication in the ApJ Letter
Saltbush-associated Asphondylia species (Diptera: Cecidomyiidae) in the Mediterranean Basin and their chalcidoid parasitoids (Hymenoptera: Chalcidoidea)
Numerous species of gall midges (Diptera: Cecidomyiidae) have been recorded from saltbush (Chenopodiaceae: Atriplex) around the world but only 11 of them belong to the large cecidomyiid genus Asphondylia. Of these, two species were de-scribed in the late 19th century from complex bud galls on Atriplex halimus in the Mediterranean Basin. In the present study Asphondylia punica is redescribed, A. conglomerata is synonymized with it, and Asphondylia scopuli is described from Atriplex lanfrancoi, an endemic plant to the Maltese Islands. Descriptions are accompanied by information about the galls and life history of the gall midges, and a review of the parasitic Hymenoptera associated with A. scopuli is provided. Four species of parasitoids were found and attributed to the families Eurytomidae, Pteromalidae, Eupelmidae and Eulophidae, of which the pteromalid Mesopolobus melitensis is described as new.peer-reviewe
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