12,078 research outputs found
The development of methods for the early identification of heart disease and related job stresses Progress report, 1 Mar. - 30 Jun. 1969
Methods for early identification of heart disease and related job stresse
Underlying symmetries of realistic interactions and the nuclear many-body problem
The present study brings forward important information, within the framework
of spectral distribution theory, about the types of forces that dominate three
realistic interactions, CD-Bonn, CDBonn+ 3terms and GXPF1, in nuclei and their
ability to account for many-particle effects such as the formation of
correlated nucleon pairs and enhanced quadrupole collective modes.
Like-particle and proton-neutron isovector pairing correlations are described
microscopically by a model interaction with Sp(4) dynamical symmetry, which is
extended to include an additional quadrupole-quadrupole interaction. The
analysis of the results for the 1f7/2 level shows that both CD-Bonn+3terms and
GXPF1 exhibit a well-developed pairing character compared to CD-Bonn, while the
latter appears to build up more (less) rotational isovector T = 1 (isoscalar T
= 0) collective features. Furthermore, the three realistic interactions are in
general found to correlate strongly with the pairing+quadrupole model
interaction, especially for the highest possible isospin group of states where
the model interaction can be used to provide a reasonable description of the
corresponding energy spectra.Comment: 12 pages, 4 figure
Duality Between the Weak and Strong Interaction Limits for Randomly Interacting Fermions
We establish the existence of a duality transformation for generic models of
interacting fermions with two-body interactions. The eigenstates at weak and
strong interaction U possess similar statistical properties when expressed in
the U=0 and U=infinity eigenstates bases respectively. This implies the
existence of a duality point U_d where the eigenstates have the same spreading
in both bases. U_d is surrounded by an interval of finite width which is
characterized by a non Lorentzian spreading of the strength function in both
bases. Scaling arguments predict the survival of this intermediate regime as
the number of particles is increased.Comment: RevTex4, 4 pages, 4 figures. Accepted for publication at Phys. Rev.
Let
Shell model study of the pairing correlations
A systematic study of the pairing correlations as a function of temperature
and angular momentum has been performed in the sd-shell region using the
spherical shell model approach. The pairing correlations have been derived for
even-even, even-odd and odd-odd systems near N=Z and also for the asymmetric
case of N=Z+4. The results indicate that the pairing content and the behavior
of pair correlations is similar in even-even and odd-mass nuclei. For odd-odd
N=Z system, angular momentum I=0 state is an isospin, t=1 neutron-proton paired
configuration. Further, these t=1 correlations are shown to be dramatically
reduced for the asymmetric case of N=Z+4. The shell model results obtained are
qualitatively explained within a simplified degenerate model
A procedure to analyze nonlinear density waves in Saturn's rings using several occultation profiles
Cassini radio science experiments have provided multiple occultation optical
depth profiles of Saturn's rings that can be used in combination to analyze
density waves. This paper establishes an accurate procedure of inversion of the
wave profiles to reconstruct the wave kinematic parameters as a function of
semi-major axis, in the nonlinear regime. This procedure is achieved from
simulated data in the presence of realistic noise perturbations, to control the
reconstruction error. By way of illustration we have applied our procedure to
the Mimas 5:3 density wave. We were able to recover precisely the kinematic
parameters from the radio experiment occultation data in most of the
propagation region; a preliminary analysis of the pressure-corrected dispersion
allowed us to determine new but still uncertain values for the opacity
( cm/g) and velocity dispersion of ( cm/s) in
the wave region. Our procedure constitutes the first step in our planned
analysis of the density waves of Saturn's rings. It is very accurate and
efficient in the far-wave region. However, improvements are required within the
first wavelength. The ways in which this method can be used to establish
diagnostics of ring physics are outlined.Comment: 50 pages,13 figures, 2 tables. Published in Icarus
Dynamics of Perfectly Wetting Drops under Gravity
We study the dynamics of small droplets of polydimethylsiloxane (PDMS)
silicone oil on a vertical, perfectly-wetting, silicon wafer. Interference
videomicroscopy allows us to capture the dynamics of these droplets. We use
droplets with a volumes typically ranging from 100 to 500 nanolitres
(viscosities from 10 to 1000 centistokes) to understand long time derivations
from classical solutions. Past researchers used one dimensional theory to
understand the typical scaling for the position of the tip of the
droplet in time . We observe this regime in experiment for intermediate
times and discover a two-dimensional, similarity solution of the shape of the
droplet. However, at long times our droplets start to move more slowly down the
plane than the scaling suggests and we observe deviations in droplet
shape from the similarity solution. We match experimental data with simulations
to show these deviations are consistent with retarded van der Waals forcing
which should become significant at the small heights observed
Some Remarks about Variable Mass Systems
We comment about the general argument given to obtain the rocket equation as
it is exposed in standard textbooks. In our opinion, it can induce students to
a wrong answer when solving variable mass problems.Comment: 2 page
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Developing theory-informed interventions to implement evidence into practice: a systematic approach using the Theoretical Domains Framework
Background: There is little systematic operational guidance about how best to develop complex interventions to reduce the gap between practice and evidence. This article is one in a series of articles documenting the development and use of the Theoretical Domains Framework (TDF) to advance the science of implementation research.
Methods: The intervention was developed considering three main components: theory, evidence, and practical issues. We used a four-step approach, consisting of guiding questions, to direct the choice of the most appropriate components of an implementation intervention: Who needs to do what, differently? Using a theoretical framework, which barriers and enablers need to be addressed? Which intervention components (behaviour change techniques and mode(s) of delivery) could overcome the modifiable barriers and enhance the enablers? And how can behaviour change be measured and understood?
Results: A complex implementation intervention was designed that aimed to improve acute low back pain management in primary care. We used the TDF to identify the barriers and enablers to the uptake of evidence into practice and to guide the choice of intervention components. These components were then combined into a cohesive intervention. The intervention was delivered via two facilitated interactive small group workshops. We also produced a DVD to distribute to all participants in the intervention group. We chose outcome measures in order to assess the mediating mechanisms of behaviour change.
Conclusions: We have illustrated a four-step systematic method for developing an intervention designed to change clinical practice based on a theoretical framework. The method of development provides a systematic framework that could be used by others developing complex implementation interventions. While this framework should be iteratively adjusted and refined to suit other contexts and settings, we believe that the four-step process should be maintained as the primary framework to guide researchers through a comprehensive intervention development process
A novel protein isoform of the RON tyrosine kinase receptor transforms human pancreatic duct epithelial cells.
The MST1R gene is overexpressed in pancreatic cancer producing elevated levels of the RON tyrosine kinase receptor protein. While mutations in MST1R are rare, alternative splice variants have been previously reported in epithelial cancers. We report the discovery of a novel RON isoform discovered in human pancreatic cancer. Partial splicing of exons 5 and 6 (P5P6) produces a RON isoform that lacks the first extracellular immunoglobulin-plexin-transcription domain. The splice variant is detected in 73% of xenografts derived from pancreatic adenocarcinoma patients and 71% of pancreatic cancer cell lines. Peptides specific to RON P5P6 detected in human pancreatic cancer specimens by mass spectrometry confirm translation of the protein isoform. The P5P6 isoform is found to be constitutively phosphorylated, present in the cytoplasm, and it traffics to the plasma membrane. Expression of P5P6 in immortalized human pancreatic duct epithelial (HPDE) cells activates downstream AKT, and in human pancreatic epithelial nestin-expressing cells, activates both the AKT and MAPK pathways. Inhibiting RON P5P6 in HPDE cells using a small molecule inhibitor BMS-777607 blocked constitutive activation and decreased AKT signaling. P5P6 transforms NIH3T3 cells and induces tumorigenicity in HPDE cells. Resultant HPDE-P5P6 tumors develop a dense stromal compartment similar to that seen in pancreatic cancer. In summary, we have identified a novel and constitutively active isoform of the RON tyrosine kinase receptor that has transforming activity and is expressed in human pancreatic cancer. These findings provide additional insight into the biology of the RON receptor in pancreatic cancer and are clinically relevant to the study of RON as a potential therapeutic target
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Revisiting Politics in Political CSR: How coercive and deliberative dynamics operate through institutional work in a Colombian company
This article analyses the political dynamics taking place within a Colombian supplier company during the implementation of a client’s global Corporate Social Responsibility (CSR) programme, which radically transformed the local understandings of the supplier’s social responsibilities. We distinguish two forms of politics in political CSR – coercive and deliberative politics – and examine how they unfold through lower-level managers’ institutional work. Our longitudinal case study identifies four types of institutional work, which combine into three political configurations – irreconcilable politics, complementary politics and aligned deliberative politics – resulting in the hybridization of explicit and implicit CSR. By analysing how local managers from emerging countries and at the bottom of the supply chain cope with the new political role of MNCs, we expand the political microfoundations of CSR and highlight the interactive and political nature of institutional work aimed at addressing major societal challenges
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