547 research outputs found
Do cognitive distortions explain the longitudinal relationship between life adversity and emotional and behavioural problems in secondary school children?
Research has shown that children exposed to life adversity are at higher risk of negative developmental outcomes than those enduring lower stress levels. Life adversity can lead, among other things, to emotional and behavioural problems. Several factors have been studied to explain this relationship, with several investigators underlining the role of thought structures such as cognitive distortions, which refer to negatively biased information‐processing of external events. This can help explain why some individuals characterised by adverse personal life stories interpret ambiguous events in a negatively biased way. This study was aimed at assessing the mediating role of cognitive distortions in the longitudinal relationship between life adversity and two dimensions of psychopathology, namely, emotional and behavioural problems in 247 secondary school children attending three state secondary schools in one county in the South East of England. An increase in life adversity was associated with an increase in cognitive distortions, which was in turn related to a higher number of symptoms reflecting behavioural issues. In terms of practical applications, an effort to protect children from further exposure to adverse life events could represent a step forward to prevent the development of future behavioural problems in at‐risk children
Effect of interchain separation on the photoinduced absorption spectra of polycarbazolyldiacetylenes
The photoinduced absorption spectra of a novel polycarbazolyldiacetylene with long aliphatic chains on the carbazolyl side groups are measured and compared with those of the unsubstituted polyDCHD. The two polymers in the blue form exhibit very similar electronic absorption spectra and Raman frequencies. This fact indicates that the conjugation length of the polydiacetylene backbone is not too affected by the long substituents. In contrast, the near steady-state photoinduced absorption spectra show that different photogeneration mechanisms are involved in the two polymers. This result can be ascribed to the role played by the interchain distance in the dynamics of the relaxation processes in polydiacetylenes
Long-lived photoexcited states in polydiacetylenes with different molecular and supramolecular organization
With the aim of determining the importance of the molecular and supramolecular organization on the excited states of polydiacetylenes, we have studied the photoinduced absorption spectra of the red form of poly[1,6-bis(3,6-didodecyl-N-carbazolyl)-2,4-hexadiyne] (polyDCHD-S) and the results compared with those of the blue form of the same polymer. An interpretation of the data is given in terms of both the conjugation length and the interbackbone separation also in relation to the photoinduced absorption spectra of both blue and red forms of poly[1,6-bis(N-carbazolyl)-2,4-hexadiyne] (polyDCHD), which does not carry the alkyl substituents on the carbazolyl side groups. Information on the above properties is derived from the analysis of the absorption and Raman spectra of this class of polydiacetylenes
NIKEL: Electronics and data acquisition for kilopixels kinetic inductance camera
A prototype of digital frequency multiplexing electronics allowing the real
time monitoring of microwave kinetic inductance detector (MKIDs) arrays for
mm-wave astronomy has been developed. Thanks to the frequency multiplexing, it
can monitor simultaneously 400 pixels over a 500 MHz bandwidth and requires
only two coaxial cables for instrumenting such a large array. The chosen
solution and the performances achieved are presented in this paper.Comment: 21 pages, 14 figure
Transmission curves and effective refraction indices of MKO near infrared consortium filters at cryogenic temperatures
We report transmission measurements at cryogenic temperatures for 4 broad-band filters of the Mauna Kea Observatories (MKO) near-infrared filter set and 5 narrow-band filters. The spectral scans were collected using the multi-mode IR instrument of the TNG telescope (NICS) in which these filters are permanently mounted and commonly used for astronomical observations. We determined the transmission curves at a temperature of 78K and found no significant red-leak up to 2.6 microns, the data are available in electronic form on the TNG web page. We also estimated the variation of the wavelength response with the incidence angle and found it compatible with an effective refractive index of about 2
The TNG Near Infrared Camera Spectrometer
NICS (acronym for Near Infrared Camera Spectrometer) is the near-infrared
cooled camera-spectrometer that has been developed by the Arcetri Infrared
Group at the Arcetri Astrophysical Observatory, in collaboration with the
CAISMI-CNR for the TNG (the Italian National Telescope Galileo at La Palma,
Canary Islands, Spain).
As NICS is in its scientific commissioning phase, we report its observing
capabilities in the near-infrared bands at the TNG, along with the measured
performance and the limiting magnitudes. We also describe some technical
details of the project, such as cryogenics, mechanics, and the system which
executes data acquisition and control, along with the related software.Comment: 7 pages, 5 figures, compiled with A&A macros. A&A in pres
A project for polarimetric observations in single dish with Medicina and Noto 32 m antennas
A project with multidisciplinary characteristics, aimed to implement the possibility of polarimetric measurements in single dish at the VLBI stations of Medicina and Noto, is presented. The project will open a new window on many
astrophysical items that may be approached using the already existing instrumentation and facilities of the two Italian radioastronomical stations. We report here some scientific backgrounds, together with some technical evaluations, on which the feasibility of the project is based
New light on the S235A-B star forming region
The S235A-B star forming region has been extensively observed in the past
from the radio to the near-IR, but what was happening in the immediate
surroundings of the water maser, placed in between the two nebulosities, was
still unclear because of insufficient resolution especially in the spectral
range from the Far-IR to the mm, even though there were sound indications that
new young stellar objects (YSOs) are being formed there. We present here new
high resolution maps at mm wavelengths in different molecules (HCO+, C34S,
H2CS, SO2 and CH3CN), as well as in the 1.2 and 3.3 mm continuum obtained with
the Plateau de Bure interferometer, and JCMT observations at 450 micron and 850
micron that unambiguously reveal the presence of new YSOs placed in between the
two HII regions S235A and S235B and associated with the water maser. A
molecular core and an unresolved source in the mm and in the sub-mm are centred
on the maser, with indication of mass infall onto the core. Two molecular
bipolar outflows and a jet originate from the same position. Weak evidence is
found for a molecular rotating disk perpendicular to the direction of the main
bipolar outflow. The derived parameters indicate that one of the YSOs is an
intermediate luminosity object (L~1000 Lsun) in a very early evolutionary
phase, embedded in a molecular core of ~100 Msun, with a temperature of 30 K.
The main source of energy for the YSO could come from gravitational infall,
thus making of this YSO a rare example of intermediate luminosity protostar
representing a link between the earliest evolutionary phases of massive stars
and low mass protostars of class 0-I.Comment: 19 pages, 22 figures, to be published in Astronomy & Astrophysic
Clumpy outer Galaxy molecular clouds and the steepening of the IMF
We report the results of high-resolution (~0.2 pc) CO(1-0) and CS(2-1)
observations of the central regions of three star-forming molecular clouds in
the far-outer Galaxy (~16 kpc from the Galactic Center): WB89 85 (Sh 2-127),
WB89 380, and WB89 437. We used the BIMA array in combination with IRAM 30-m
and NRAO 12-m observations. The GMC's in which the regions are embedded were
studied by means of KOSMA 3-m CO(2-1) observations. The properties the CO and
CS clumps are analyzed and compared with newly derived results of previously
published single-dish measurements of local clouds (OrionB South and Rosette).
We find that the slopes of the clump mass distributions (-1.28 and -1.49, for
WB89 85 and WB89 380, respectively) are somewhat less steep than found for most
local clouds, but similar to those of clouds which have been analyzed with the
same clumpfind program. We investigate the clump stability by using the virial
theorem, including all possible contributions (gravity, turbulence, magnetic
fields, and pressure due to the interclump gas). It appears that under
reasonable assumptions a combination of these forces would render most clumps
stable. Comparing only gravity and turbulence, we find that in the far-outer
Galaxy clouds, these forces are in equilibium (virial parameter alpha~1) for
clumps down to the lowest masses found (a few Msol). For clumps in the local
clouds alpha~1 only for clumps with masses larger than a few tens of Msol. Thus
it appears that in these outer Galaxy clumps gravity is the dominant force down
to a much lower mass than in local clouds, implying that gravitational collapse
and star formation may occur more readily even in the smallest clumps. Although
there are some caveats, due to the inhomogeneity of the data used, this might
explain the apparently steeper IMF found in the outer Galaxy.Comment: 29 pages, including 9 tables, 21 figures. Accepted for Astron.
Astrop
VLA Observations of H2O Masers in the Class 0 Protostar S106 FIR: Evidence for a 10 AU-Scale Accelerating Jet-like Flow
We conducted VLA observations at 0".06 resolution of the 22 GHz water masers
toward the Class 0 source S106 FIR (d=600 pc; 15" west of S106-IRS4) on two
epochs separated by ~3 months. Two compact clusters of the maser spots were
found in the center of the submillimeter core of S106 FIR. The separation of
the clusters was ~80 mas (48 AU) along P. A. = 70 degrees and the size of each
cluster was ~20 mas x 10 mas. The western cluster, which had three maser
components, was 7.0 km/s redshifted with respect to the ambient cloud velocity.
Each component was composed of a few spatially localized maser spots and was
aligned on a line connecting the clusters. We found relative proper motions of
the components with ~30 mas/yr (18 AU/yr) along the line. In addition, a series
of single-dish observations show that the maser components drifted with a
radial acceleration of ~1 km/s/yr.
These facts indicate that the masers could be excited by a 10 AU-scale
jet-like accelerating flow ejected from an assumed protostar located between
the two clusters. The outflow size traced by the masers was 50 AU x 5 AU after
correction for an inclination angle of 10 degrees which was derived from the
relative proper motions and radial velocities of the maser components. The
three-dimensional outflow velocity ranged from 40 to 70 km/s assuming symmetric
motions for the blue and red components. Since no distinct CO molecular
outflows have been detected so far, we suggest that S106 FIR is an extremely
young protostar observed just after the onset of outflowing activity.Comment: 24 pages, 6 figures, No. 5 color. Accepted, Astrophysical Journa
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