121 research outputs found
Isolement chez le Fennec (Fennecus zerda) d’une souche de toxoplasme pathogène pour le Chien
Vallée A., Destombes P. Isolement chez le Fennec (Fennecus Zerda) d’une souche de toxoplasme pathogène pour le Chien. In: Bulletin de l'Académie Vétérinaire de France tome 113 n°4, 1960. pp. 223-224
Reins polykystiques observés chez des Cyprinidés d'un étang de l'Eure
Besse P., Levaditi J.-C., Destombes P., Nazimoff O., Guillot Jacques. Reins polykystiques observés chez les Cyprinidés d'un étang de l'Eure. In: Bulletin de l'Académie Vétérinaire de France tome 112 n°7, 1959. pp. 421-426
HI Narrow Self-Absorption in Dark Clouds: Correlations with Molecular Gas and Implications for Cloud Evolution and Star Formation
We present the results of a comparative study of HI narrow self-absorption
(HINSA), OH, 13CO, and C18O in five dark clouds. The HINSA follows the
distribution of the emission of the carbon monoxide isotopologues, and has a
characteristic size close to that of 13CO. This confirms that the HINSA is
produced by cold HI which is well mixed with molecular gas in well-shielded
regions. The ratio of the atomic hydrogen density to total proton density for
these sources is 5 to 27 x 10^{-4}. Using cloud temperatures and the density of
HI, we set an upper limit to the cosmic ray ionization rate of 10^{-16} s^{-1}.
Comparison of observed and modeled fractional HI abundances indicates ages for
these clouds to be 10^{6.5} to 10^{7} yr. The low values of the HI density we
have determined make it certain that the time scale for evolution from an
atomic to an almost entirely molecular phase, must be a minimum of several
million years. This clearly sets a lower limit to the overall time scale for
star formation and the lifetime of molecular clouds
A search for 4750- and 4765-MHz OH masers in Southern Star Forming Regions
We have used the Australia Telescope Compact Array (ATCA) to make a sensitive
(5- 100 mJy) search for maser emission from the 4765-MHz
F=10 transition of OH. Fifty five star formation regions
were searched and maser emission with a peak flux density in excess of 100 mJy
was detected toward fourteen sites, with ten of these being new discoveries. In
addition we observed the 4750-MHz F=11 transition towards a
sample of star formation regions known to contain 1720-MHz OH masers, detecting
marginal maser emission from G348.550-0.979. If confirmed this would be only
the second maser discovered from this transition. The occurrence of 4765-MHz OH
maser emission accompanying 1720-MHz OH masers in a small number of well
studied star formation regions has lead to a general perception in the
literature that the two transitions favour similar physical conditions. Our
search has found that the presence of the excited-state 6035-MHz OH transition
is a much better predictor of 4765-MHz OH maser emission from the same region
than is 1720-MHz OH maser emission. Combining our results with those of
previous high resolution observations of other OH transitions we have examined
the published theoretical models of OH masers and find that none of them
predict any conditions in which the 1665-, 6035- and 4765-MHz transitions are
simultaneously inverted.
Erratum abstract:
Dodson & Ellingsen (2002) included several observations with significant
pointing errors, invalidating the upper limits found in these directions. These
have now been reobserved or recalculated. A new table of upper limits has been
generated, and two more masers that would have been seen have been found.Comment: Included an Erratum with Max as another author. This erratum was
rejected by MNRAS (Feb 04) as it contained too much data. Resubmitted as a
paper (Jun 04). Rejected (Sep 04) it had too little data. Resubmitted as
reduced erratum (Apr 05). Still waitin
ISO LWS Spectroscopy of M82: A Unified Evolutionary Model
We present the first complete far-infrared spectrum (43 to 197 um) of M82,
the brightest infrared galaxy in the sky, taken with the Long Wavelength
Spectrometer of the Infrared Space Observatory (ISO). We detected seven fine
structure emission lines, [OI] 63 and 145 um, [OIII] 52 and 88 um, [NII] 122
um, [NIII] 57 um and [CII] 158 um, and fit their ratios to a combination
starburst and photo-dissociation region (PDR) model. The best fit is obtained
with HII regions with n = 250 cm^{-3} and an ionization parameter of 10^{-3.5}
and PDRs with n = 10^{3.3} cm^{-3} and a far-ultraviolet flux of G_o =
10^{2.8}. We applied both continuous and instantaneous starburst models, with
our best fit being a 3-5 Myr old instantaneous burst model with a 100 M_o
cut-off. We also detected the ground state rotational line of OH in absorption
at 119.4 um. No excited level OH transitions are apparent, indicating that the
OH is almost entirely in its ground state with a column density ~ 4x10^{14}
cm^{-2}. The spectral energy distribution over the LWS wavelength range is well
fit with a 48 K dust temperature and an optical depth, tau_{Dust} proportional
to lambda^{-1}.Comment: 23 pages, 4 figures, accepted by ApJ, Feb. 1, 199
Phase-Referenced VLBA Observations of OH Masers at 4765 MHz
We report VLBA observations of maser emission from the rotationally excited
doublet Pi 1/2, J=1/2 state of OH at 4765 MHz. We made phase-referenced
observations of W3(OH) at both 4765 MHz and 1720 MHz and found emission in
three fields within a about 2000 AU diameter region and verified that in two of
the three fields, 4765 MHz and 1720 MHz emission arise from the same position
to within about 4 mas (about 5 AU diameter emission regions along an
approximately N-S arc with linear extent about 500 AU. In addition, we carried
out phase-referenced observations of 4765 MHz emission from K3-50. We searched
for the 4765 MHz line in W49 (without phase referencing) and W75N
(phase-referenced to the strongest 4765 MHz maser feature in DR21EX); we were
unable to detect these sources with the VLBA. For 2 1/2 years (including the
dates of the VLBA observations), we carried out monitoring observations of 4765
MHz emission with the VLA. Constraints on models for maser emission at 1720 MHz
and 4765 MHz are derived from the observations. These observations are then
briefly compared with existing models.Comment: 30 pages, 7 figures, to be published in Ap. J. (Dec 10, 2003
Strategic maintenance technique selection using combined quality function deployment, the analytic hierarchy process and the benefit of doubt approach
The business performance of manufacturing organizations depends on the reliability and productivity of equipment, machineries and entire manufacturing system. Therefore, the main role of maintenance and production managers is to keep manufacturing system always up by adopting most appropriate maintenance methods. There are alternative maintenance techniques for each machine, the selection of which depend on multiple factors. The contemporary approaches to maintenance technique selection emphasize on operational needs and economic factors only. As the reliability of production systems is the strategic intent of manufacturing organizations, maintenance technique selection must consider strategic factors of the concerned organization along with operational and economic criteria. The main aim of this research is to develop a method for selecting the most appropriate maintenance technique for manufacturing industry with the consideration of strategic, planning and operational criteria through involvement of relevant stakeholders. The proposed method combines quality function deployment (QFD), the analytic hierarchy process (AHP) and the benefit of doubt (BoD) approach. QFD links strategic intents of the organizations with the planning and operational needs, the AHP helps in prioritizing the criteria for selection and ranking the alternative maintenance techniques, and the BoD approach facilitates analysing robustness of the method through sensitivity analysis through setting the realistic limits for decision making. The proposed method has been applied to maintenance technique selection problems of three productive systems of a gear manufacturing organization in India to demonstrate its effectiveness
Histological and microbiological aspects of actinomycetoma cases in Venezuela
A ten year (1976-1986) review study of cases of Actinomycetoma in Venezuela was made through personal interview and clinical examinations, analysis of medical records of patients with actinomycetoma, histological studies of biopsy samples, as well as microbiological studies of isolates strain, also through out personal interviews with researchers and dermatologists who were sources of information on mycetoma cases. A total of 47 cases were recorded. As etiologic agent Actinomadura madurae was found in 20 cases - (42.5%), Nocardia brasiliensis in 13 cases (27.6%), Nocardia spp 7 cases (14.8%), Streptomyces somaliensis in 4 cases (8.5%), N. asteroides in 2 cases (4.2%) and N. otitidis caviarum, (N. caviae) in 1 case (2.1%). Most of the reported cases involved individuals living and working in rural areas, mostly males who outnumber females 4:1. The patients were 18 to 80 years old. A. madurae was reported as the most frequent etiologic agent. Most of the clinical cases were seen when the disease was well established. Twenty four of the forty seven cases reported were observed in Lara State, which represents a 51.0% of all the cases studied
Etude histopathologique de la nocardiose du boeuf au Tchad et caractères biochimiques de Nocardia farcinica
L'histologie des lésions dues à Nocardia farcinica a été faite sur des ganglions de zébus tchadiens prélevés à l'abattoir de Fort-Lamy. Du fait de la ressemblance de ces lésions, par leur localisation et leur aspect macroscopique avec celles de la tuberculose, ce moyen d'étude, réservé au laboratoire, permet un diagnostic différentiel. Quelques caractères culturaux et biochimiques des souches isolées de ces lésions ganglionnaires ont été étudiés. Ils ont été comparés avec ceux de souches de Nocardia farcinica et Nocardia asteroides, provenant d'autres pays ou de collections étrangères. L'ensemble de ces caractères permet de distinguer des variétés parmi les souches de Nocardia farcinic
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