1,277 research outputs found
The census of complex organic molecules in the solar type protostar IRAS16293-2422
Complex Organic Molecules (COMs) are considered crucial molecules, since they
are connected with organic chemistry, at the basis of the terrestrial life.
More pragmatically, they are molecules in principle difficult to synthetize in
the harsh interstellar environments and, therefore, a crucial test for
astrochemical models. Current models assume that several COMs are synthesised
on the lukewarm grain surfaces (30-40 K), and released in the gas
phase at dust temperatures 100 K. However, recent detections of COMs
in 20 K gas demonstrate that we still need important pieces to
complete the puzzle of the COMs formation. We present here a complete census of
the oxygen and nitrogen bearing COMs, previously detected in different ISM
regions, towards the solar type protostar IRAS16293-2422. The census was
obtained from the millimeter-submillimeter unbiased spectral survey TIMASSS.
Six COMs, out of the 29 searched for, were detected: methyl cyanide, ketene,
acetaldehyde, formamide, dimethyl ether, and methyl formate. The multifrequency
analysis of the last five COMs provides clear evidence that they are present in
the cold (30 K) envelope of IRAS16293-2422, with abundances 0.03-2
. Our data do not allow to support the hypothesis that the
COMs abundance increases with increasing dust temperature in the cold envelope,
as expected if COMs were predominately formed on the lukewarm grain surfaces.
Finally, when considering also other ISM sources, we find a strong correlation
over five orders of magnitude, between the methyl formate and dimethyl ether
and methyl formate and formamide abundances, which may point to a link between
these two couples of species, in cold and warm gas
EXPLORING INTERGENERATIONAL TRANSMISSION OF TRAUMA IN THIRD GENERATION HOLOCAUST SURVIVORS
Over sixty-five years ago the Jewish people were liberated from Nazi Europe. Since that time, researchers have found that the Holocaust has had a psychological, social, and cultural effect on first and second generation survivors. Despite the significant amount of research that has been done on Holocaust survivors and their offspring, little has been investigated about when, why and how surviving generations begin to move past pathological symptoms. This study explored the impact the Holocaust had on third generation survivors through administering an eight item semi-structured questionnaire called, The Third Generation Questionnaire, which was created for the purpose of this study. The questions emerged from the literature as well as the search for perceptions and meanings and utilized Vikor Frankl’s existential theory. The questionnaire was administered to a purposive sample of (N=30) of third generation survivors through REDCap, an online survey database. Previous research points to the transmission of pathologic symptoms; this study strongly suggests that among third generation survivors, pride, strength, and gratitude are as much a part of the legacy as the negative effects of the experience. The third generation appears to be reconstructing their grandparents’ history, resurfacing their legacy, and in doing so they are realizing the strength and heroic battles their grandparents fought in order to get to the place they are today. Findings indicate that rather than ruminating on the pain of their ancestors, focusing attention on their strength may result in the ability to move past the pathological symptoms. Focusing this study on third generation survivors expands scientific knowledge regarding transmission of trauma and provides direction to clinical social workers treating individuals who may have a history of intergenerational trauma
Project management : learning by breaking the rules
The paper explores project management in action in a large public research organisation – NLAT which decided to change its internal organisation from team-based to project-based organisation a few years ago. A systematic and comparative analysis of 8 projects reveals that adherence to the ISO 9000’s standardized rules of project management - specific staffing and project leaders, definition of milestones ex ante, procedure manuals, and formalized learning accumulation mechanisms - had little to do with the organisations success over recent years: Looking for explanations for this success, the paper focuses on the process of transferring from one project to another, enhancing organisational learning through rules breaking. We identify three elements which encourage the accumulation of knowledge and competencies, as organisational learning: low project core staffing levels which stimulates the circulation of engineers and researchers between projects and blurs project boundaries, implementing and managing thematic projects which build on specific competencies developed in dedicated projects and encouraging ‘bricolage’ to hybridise project management with traditional hierarchical management practices.PROJECT MANAGEMENT;R&D;HIGH TECH;MANAGEMENT PRACTICES
Disk-Like Structure in the Semi-Regular Pulsating Star, X Her
The author reports a result of an interferometric observation of the
semiragular pulsating star with an unusual narrow molecular line profile, X
Her, in the CO J=1-0 line with the Berkeley-Illinois-Maryland array. In the CO
spectrum, a double-component profile (including narrow and broad components) is
seen as reported by previous observations. The narrow component consists of two
spiky peaks. The spatial structure of the board component shows bipolar shape,
and that of the narrow component shows an elliptical/spherical shape. The two
peaks in the narrow component show a systematic difference in the integrated
intensity map. The kinematical and geometrical properties of the narrow
component are reminiscent of a Keplerian rotating disk with the central mass of
0.9 M_sun, though an interpretation by an expansion disk seems to be more
natural. A secondary bipolar flow instead of the disk cannot be fully excluded
as an interpretation of the narrow line.Comment: 12 pages, 4 figues, accepted for publication in Ap
Shedding light on the formation of the pre-biotic molecule formamide with ASAI
Formamide (NH2CHO) has been proposed as a pre-biotic precursor with a key
role in the emergence of life on Earth. While this molecule has been observed
in space, most of its detections correspond to high-mass star-forming regions.
Motivated by this lack of investigation in the low-mass regime, we searched for
formamide, as well as isocyanic acid (HNCO), in 10 low- and intermediate-mass
pre-stellar and protostellar objects. The present work is part of the IRAM
Large Programme ASAI (Astrochemical Surveys At IRAM), which makes use of
unbiased broadband spectral surveys at millimetre wavelengths. We detected HNCO
in all the sources and NH2CHO in five of them. We derived their abundances and
analysed them together with those reported in the literature for high-mass
sources. For those sources with formamide detection, we found a tight and
almost linear correlation between HNCO and NH2CHO abundances, with their ratio
being roughly constant -between 3 and 10- across 6 orders of magnitude in
luminosity. This suggests the two species are chemically related. The sources
without formamide detection, which are also the coldest and devoid of hot
corinos, fall well off the correlation, displaying a much larger amount of HNCO
relative to NH2CHO. Our results suggest that, while HNCO can be formed in the
gas phase during the cold stages of star formation, NH2CHO forms most
efficiently on the mantles of dust grains at these temperatures, where it
remains frozen until the temperature rises enough to sublimate the icy grain
mantles. We propose hydrogenation of HNCO as a likely formation route leading
to NH2CHO.Comment: 26 pages, 9 figures. Accepted by Monthly Notices of the Royal
Astronomical Societ
Vocal aging and adductor spasmodic dysphonia: Response to botulinum toxin injection
Aging of the larynx is characterized by involutional changes which alter its biomechanical and neural properties and create a biological environment that is different from younger counterparts. Illustrative anatomical examples are presented. This natural, non-disease process appears to set conditions which may influence the effectiveness of botulinum toxin injection and our expectations for its success. Adductor spasmodic dysphonia, a type of laryngeal dystonia, is typically treated using botulinum toxin injections of the vocal folds in order to suppress adductory muscle spasms which are disruptive to production of speech and voice. A few studies have suggested diminished response to treatment in older patients with adductor spasmodic dysphonia. This retrospective study provides a reanalysis of existing pre-to-post treatment data as function of age. Perceptual judgments of speech produced by 42 patients with ADSD were made by two panels of professional listeners with expertise in voice or fluency of speech. Results demonstrate a markedly reduced positive response to botulinum toxin treatment in the older patients. Perceptual findings are further elucidated by means of acoustic spectrography. Literature on vocal aging is reviewed to provide a specific set of biological mechanisms that best account for the observed interaction of botulinum toxin treatment with advancing age
Elastic and Raman scattering of 9.0 and 11.4 MeV photons from Au, Dy and In
Monoenergetic photons between 8.8 and 11.4 MeV were scattered elastically and
in elastically (Raman) from natural targets of Au, Dy and In.15 new cross
sections were measured. Evidence is presented for a slight deformation in the
197Au nucleus, generally believed to be spherical. It is predicted, on the
basis of these measurements, that the Giant Dipole Resonance of Dy is very
similar to that of 160Gd. A narrow isolated resonance at 9.0 MeV is observed in
In.Comment: 31 pages, 11 figure
A spectral line survey in the 2 mm and 1.3 mm windows toward the carbon rich envelope of IRC +10216
We present the results of our spectral line surveys in the 2 mm and 1.3 mm
windows toward the carbon rich envelope of IRC +10216. Totally 377 lines are
detected, among which 360 lines are assigned to 57 known molecules (including
29 rare isotopomers and 2 cyclic isomers). Only 17 weak lines remain
unidentified. Rotational lines of isotopomers 13CCH and HN13C are detected for
the first time in IRC +10216. The detection of the formaldehyde lines in this
star is also confirmed. Possible abundance difference among the three 13C
substituted isotopic isomers of HC3N is reported. Isotopic ratios of C and O
are confirmed to be non-solar while those of S and Si to be nearly solar.
Column densities have been estimated for 15 molecular species. Modified
spectroscopic parameters have been calculated for NaCN, Na13CN, KCN and SiC2.
Transition frequencies from the present observations were used to improve the
spectroscopic parameters of Si13CC, 29SiC2 and 30SiC2.Comment: 17 pages of text, 18 pages of 14 tables, 35 pages of 4 figures, a
typo corrected in Abstrac
Observational evidence of the formation of cyanopolyynes in CRL618 through the polimerization of HCN
The abundance ratio of consecutive members of the cyanopolyynes family has
been explored in CRL618 using data acquired in a complete line survey covering
the frequency range 81-356 GHz. The Jup range explored for the different
molecules is the following: 1 to 4 for HCN and HNC, 9 to 39 for HC3N, 31 to 133
for HC5N, and 72 to 85 for HC7N (not detected beyond Jup=85). The lowest
vibrationally excited state of HC7N (nu_15 at 62 cm^-1) has been tentatively
detected. Data analysis has been performed by extending our previous
geometrical and radiative transfer model of the slowly expanding envelope (SEE)
surrounding the compact central continuum source of CRL 618, that was
established from the study of rotational lines in several vibrationally excited
states of HC_3N. The new lines analyzed here require to model the high velocity
wind (HVW) component and the colder circumstellar gas, remnant of the AGB phase
of CRL618. The derived HC3N/HC5N and HC5N/HC7N abundance ratios from this set
of uniformly calibrated lines are between 3 and 6 in the different regions,
similar to standard values in the CSM and ISM, and consistent with previous
estimates obtained from ISO observations and chemical models. However, the
abundance ratios of HC3N, HC5N and HC7N with respect to HCN are at least two
orders of magnitude larger than those typical for AGB C-rich stars, such as
IRC+10216. This fact indicates that, in the short transition toward the
Planetary Nebula phase, HCN is quickly reprocessed into longer cyanopolyyne
chains. A similar behavior was previously found in this object for the
polyacetylenic chains (C(2n)H2).Comment: 8 figures, accepted in ApJ main journa
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