2,810 research outputs found
How can a 22-pole ion trap exhibit 10 local minima in the effective potential?
The column density distribution of trapped OH ions in a 22-pole ion trap
is measured for different trap parameters. The density is obtained from
position-dependent photodetachment rate measurements. Overall, agreement is
found with the effective potential of an ideal 22-pole. However, in addition we
observe 10 distinct minima in the trapping potential, which indicate a breaking
of the 22-fold symmetry. Numerical simulations show that a displacement of a
subset of the radiofrequency electrodes can serve as an explanation for this
symmetry breaking
Imposter Phenomenon and Research Experiences Among Counselor Educators
Content analysis was employed to explore research experiences and imposter phenomenon (IP) among 25 counselor educators. Six overarching categories emerged including inconsistent areas of efficacy in the research process, supports in conducting research, barriers in conducting research, experiences of IP across roles, triggers of IP, and factors that quiet IP, with implications for counselor educators
DECam integration tests on telescope simulator
The Dark Energy Survey (DES) is a next generation optical survey aimed at
measuring the expansion history of the universe using four probes: weak
gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and
Type Ia supernovae. To perform the survey, the DES Collaboration is building
the Dark Energy Camera (DECam), a 3 square degree, 570 Megapixel CCD camera
which will be mounted at the Blanco 4-meter telescope at the Cerro Tololo
Inter- American Observatory. DES will survey 5000 square degrees of the
southern galactic cap in 5 filters (g, r, i, z, Y). DECam will be comprised of
74 250 micron thick fully depleted CCDs: 62 2k x 4k CCDs for imaging and 12 2k
x 2k CCDs for guiding and focus. Construction of DECam is nearing completion.
In order to verify that the camera meets technical specifications for DES and
to reduce the time required to commission the instrument, we have constructed a
full sized telescope simulator and performed full system testing and
integration prior to shipping. To complete this comprehensive test phase we
have simulated a DES observing run in which we have collected 4 nights worth of
data. We report on the results of these unique tests performed for the DECam
and its impact on the experiments progress.Comment: Proceedings of the 2nd International Conference on Technology and
Instrumentation in Particle Physics (TIPP 2011). To appear in Physics
Procedia. 8 pages, 3 figure
Total colonic aganglionosis : multicentre study of surgical treatment and patient-reported outcomes up to adulthood
Background: Surgery for total colonic aganglionosis (TCA) is designed to preserve continence and achieve satisfactory quality of life. This study evaluated a comprehensive group of clinical and social outcomes. Methods: An international multicentre study from eight Nordic hospitals involving examination of case records and a patient-reported questionnaire survey of all patients born with TCA between 1987 and 2006 was undertaken. Results: Of a total of 116 patients, five (4 center dot 3 per cent) had died and 102 were traced. Over a median follow-up of 12 (range 0 center dot 3-33) years, bowel continuity was established in 75 (73 center dot 5 per cent) at a median age of 11 (0 center dot 5-156) months. Mucosectomy with a short muscular cuff and straight ileoanal anastomosis (SIAA) (29 patients) or with aJpouch (JIAA) (26) were the most common reconstructions (55 of 72, 76 per cent). Major early postoperative complications requiring surgical intervention were observed in four (6 per cent) of the 72 patients. In 57 children aged over 4 years, long-term functional bowel symptoms after reconstruction included difficulties in holding back defaecation in 22 (39 per cent), more than one faecal accident per week in nine (16 per cent), increased frequency of defaecation in 51 (89 per cent), and social restrictions due to bowel symptoms in 35 (61 per cent). Enterocolitis occurred in 35 (47 per cent) of 72 patients. Supplementary enteral and/or parenteral nutrition was required by 51 (55 per cent) of 93 patients at any time during follow-up. Of 56 responders aged 2-20 years, true low BMI for age was found in 20 (36 per cent) and 13 (23 per cent) were short for age. Conclusion: Reconstruction for TCA was associated with persistent bowel symptoms, and enterocolitis remained common. Multidisciplinary follow-up, including continuity of care in adulthood, might improve care standards in patients with TCA.Peer reviewe
Computed Rotational Collision Rate Coefficients for Recently Detected Anionic Cyanopolyynes
We report new results from quantum calculations of energy-transfer processes
taking place in interstellar environments and involving two newly observed
molecular species: CN and CN in collision with He atoms and the
p-H molecules. These species are part of the anionic molecular chains
labeled as cyanopolyynes which have been observed over the years in
molecule-rich Circumstellar Envelopes and in molecular clouds. In the present
work, we first carry out new calculations for the CN
interaction potential with He atom and then obtain state-to-state rotationally
inelastic cross sections and rate coefficients involving the same transitions
which have been observed experimentally by emission in the interstellar medium
(ISM) from both of these linear species. For the CN/He system we extend
the calculations already published in our earlier work (see reference below) to
compare more directly the two molecular anions. We extend further the quantum
calculations by also computing in this work collision rate coefficients for the
hydrogen molecule interacting with C5N, using our previously computed
interaction potential. Additionally, we obtain the same rate coefficients for
the CN/H system by using a scaling procedure that makes use of the
new CN/He rate coefficients, as discussed in detail in the present
paper. Their significance in affecting internal state populations in ISM
environments where the title anions have been found is analyzed by using the
concept of critical density indicators. Finally, similarities and differences
between such species and the comparative efficiency of their collision rate
coefficients are discussed. These new calculations suggest that, at least for
the case of these longer chains, the rotational populations could reach local
thermal equilibrium conditions within their observational environments
Cosmological constraints from COMBO-17 using 3D weak lensing
We present the first application of the 3D cosmic shear method developed in
Heavens et al. (2006) and the geometric shear-ratio analysis developed in
Taylor et al. (2006), to the COMBO-17 data set. 3D cosmic shear has been used
to analyse galaxies with redshift estimates from two random COMBO-17 fields
covering 0.52 square degrees in total, providing a conditional constraint in
the (sigma_8, Omega_m) plane as well as a conditional constraint on the
equation of state of dark energy, parameterised by a constant w= p/rho c^2. The
(sigma_8, Omega_m) plane analysis constrained the relation between sigma_8 and
Omega_m to be sigma_8(Omega_m/0.3)^{0.57 +- 0.19}=1.06 +0.17 -0.16, in
agreement with a 2D cosmic shear analysis of COMBO-17. The 3D cosmic shear
conditional constraint on w using the two random fields is w=-1.27 +0.64 -0.70.
The geometric shear-ratio analysis has been applied to the A901/2 field, which
contains three small galaxy clusters. Combining the analysis from the A901/2
field, using the geometric shear-ratio analysis, and the two random fields,
using 3D cosmic shear, w is conditionally constrained to w=-1.08 +0.63 -0.58.
The errors presented in this paper are shown to agree with Fisher matrix
predictions made in Heavens et al. (2006) and Taylor et al. (2006). When these
methods are applied to large datasets, as expected soon from surveys such as
Pan-STARRS and VST-KIDS, the dark energy equation of state could be constrained
to an unprecedented degree of accuracy.Comment: 10 pages, 4 figures. Accepted to MNRA
EM and XRM Connectomics Imaging and Experimental Metadata Standards
High resolution volumetric neuroimaging datasets from electron microscopy
(EM) and x-ray micro and holographic-nano tomography (XRM/XHN) are being
generated at an increasing rate and by a growing number of research teams.
These datasets are derived from an increasing number of species, in an
increasing number of brain regions, and with an increasing number of
techniques. Each of these large-scale datasets, often surpassing petascale
levels, is typically accompanied by a unique and varied set of metadata. These
datasets can be used to derive connectomes, or neuron-synapse level
connectivity diagrams, to investigate the fundamental organization of neural
circuitry, neuronal development, and neurodegenerative disease. Standardization
is essential to facilitate comparative connectomics analysis and enhance data
utilization. Although the neuroinformatics community has successfully
established and adopted data standards for many modalities, this effort has not
yet encompassed EM and XRM/ XHN connectomics data. This lack of standardization
isolates these datasets, hindering their integration and comparison with other
research performed in the field. Towards this end, our team formed a working
group consisting of community stakeholders to develop Image and Experimental
Metadata Standards for EM and XRM/XHN data to ensure the scientific impact and
further motivate the generation and sharing of these data. This document
addresses version 1.1 of these standards, aiming to support metadata services
and future software designs for community collaboration. Standards for derived
annotations are described in a companion document. Standards definitions are
available on a community github page. We hope these standards will enable
comparative analysis, improve interoperability between connectomics software
tools, and continue to be refined and improved by the neuroinformatics
community.Comment: 15 Pages, 3 figures, 2 table
The magnetic dipole transitions in the binding system
The magnetic dipole transitions between the vector mesons and their
relevant pseudoscalar mesons (, , , ,
and etc, the binding states of system) of
the family are interesting. To see the `hyperfine' splitting due to
spin-spin interaction is an important topic for understanding the spin-spin
interaction and the spectrum of the the binding system. The
knowledge about the magnetic dipole transitions is also very useful for
identifying the vector boson mesons experimentally, whose masses are
just slightly above the masses of their relevant pseudoscalar mesons
accordingly. Considering the possibility to observe the vector mesons via the
transitions at factory and the potentially usages of the theoretical
estimate on the transitions, we fucus our efforts on calculating the magnetic
dipole transitions, i.e. precisely to calculate the rates for the transitions
such as decays and , and particularly
work in the Behte-Salpeter framework. In the estimate, as a typical example, we
carefully investigate the dependance of the rate
on the mass difference as well.Comment: 10 pages, 2 figures, 1 tabl
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