20,104 research outputs found
Non-Scissors-Mode Behaviour of Isovector Magnetic Dipole Orbital Transitions Involving Isospin Transfer
We study the response of isovector orbital magnetic dipole (IOMD) transitions
to the quadrupole-quadrupole () interaction, to the
isospin-conserving pairing interaction (ICP) and to combinations of both. We
find qualitatively different behaviours for transitions in which the final
isospin differs from the initial isospin versus cases where the two isospins
are the same. For even-even nuclei with ground states
such as and , the summed IOMD from the ground
state to all the states in the space does not
vanish when the interaction is turned off. The pairing interaction
(ICP) alone leads to a finite transition rate. For nuclei with
ground states such as and , the summed IOMD
vanish when the interaction is turned off, as is expected in
a good scissors-mode behaviour. However this is not the case for the
corresponding sum of the IOMD transitions. In (but not
in ) the sum of the IOMD transitions is remarkably
insensitive to the strengths of both the and the ICP interactions.
In an energy weighted-sum is similarly insensitive. All our
calculations were carried out in the space.Comment: 19 pages (including 5 figures). submitted to Nucl. Phys.
Platelet-rich gel for the adjuvant treatment of wound healing of transposed flap for arteriovenous fistula in systemic scleroderma
LETTER TO EDITO
Extracellular vesicle microRNAs contribute to the osteogenic inhibition of mesenchymal stem cells in multiple myeloma
Osteolytic bone disease is the major complication associated with the progression of multiple myeloma (MM). Recently, extracellular vesicles (EVs) have emerged as mediators of MM-associated bone disease by inhibiting the osteogenic differentiation of human mesenchymal stem cells (hMSCs). Here, we investigated a correlation between the EV-mediated osteogenic inhibition and MM vesicle content, focusing on miRNAs. By the use of a MicroRNA Card, we identified a pool of miRNAs, highly expressed in EVs, from MM cell line (MM1.S EVs), expression of which was confirmed in EVs from bone marrow (BM) plasma of patients affected by smoldering myeloma (SMM) and MM. Notably,we found that miR-129-5p, which targets different osteoblast (OBs) differentiation markers, is enriched in MM-EVs compared to SMM-EVs, thus suggesting a selective packaging correlated with pathological grade. We found that miR-129-5p can be transported to hMSCs by MM-EVs and, by the use of miRNA mimics, we investigated its role in recipient cells. Our data demonstrated that the increase of miR-129-5p levels in hMSCs under osteoblastic differentiation stimuli inhibited the expression of the transcription factor Sp1, previously described as a positive modulator of osteoblastic differentiation, and of its target the Alkaline phosphatase (ALPL), thus identifying miR-129-5p among the players of vesicle-mediated bone disease
Orbital Magnetic Dipole Mode in Deformed Clusters: A Fully Microscopic Analysis
The orbital M1 collective mode predicted for deformed clusters in a schematic
model is studied in a self-consistent random-phase-approximation approach which
fully exploits the shell structure of the clusters. The microscopic mechanism
of the excitation is clarified and the close correlation with E2 mode
established. The study shows that the M1 strength of the mode is fragmented
over a large energy interval. In spite of that, the fraction remaining at low
energy, well below the overwhelming dipole plasmon resonance, is comparable to
the strength predicted in the schematic model. The importance of this result in
view of future experiments is stressed.Comment: 10 pages, 3 Postscript figures, uses revte
cyTRON and cyTRON/JS: two Cytoscape-based applications for the inference of cancer evolution models
The increasing availability of sequencing data of cancer samples is fueling
the development of algorithmic strategies to investigate tumor heterogeneity
and infer reliable models of cancer evolution. We here build up on previous
works on cancer progression inference from genomic alteration data, to deliver
two distinct Cytoscape-based applications, which allow to produce, visualize
and manipulate cancer evolution models, also by interacting with public genomic
and proteomics databases. In particular, we here introduce cyTRON, a
stand-alone Cytoscape app, and cyTRON/JS, a web application which employs the
functionalities of Cytoscape/JS.
cyTRON was developed in Java; the code is available at
https://github.com/BIMIB-DISCo/cyTRON and on the Cytoscape App Store
http://apps.cytoscape.org/apps/cytron. cyTRON/JS was developed in JavaScript
and R; the source code of the tool is available at
https://github.com/BIMIB-DISCo/cyTRON-js and the tool is accessible from
https://bimib.disco.unimib.it/cytronjs/welcome
Pause-and-Go Self-Balancing Formation Control of Autonomous Vehicles Using Vision and Ultrasound Sensors
In this work, we implement a decentralized and noncooperative state estimation and control algorithm to autonomously balance a team of robots in a circular formation pattern. The group of robots includes a leader periodically moving at a constant steering angle and a set of followers that, by only leveraging intermittent and noisy proximity measurements, independently implement a fully decentralized state estimation control algorithm to determine and adjust their relative position with closest neighbors. The algorithm is conducted in a pause-and-go sequence, where, during the pause, each robot stops to gather and process the information coming from the measurements, estimate the relative phase with respect to the others, and identify its closest pursuant. During the go, each robot accelerates to space from its closest pursuant and then to move at a constant speed when the desired spacing is achieved. The algorithm is tested in an unprecedented experiment on a custom-made low-cost caster-wheeled robotic framework featuring sonar and vision sensors mounted on a rotating platform to estimate the proximity distance to closer neighbors. The control scheme, which does not necessitate cooperation and is capable of coping with uncertain and intermittent sensor feedback data, is shown to be effective in balancing the robot on the circle even when, at a steady state, no feedback sensor data are available
Additive Equivalence in Turbulent Drag Reduction by Flexible and Rodlike Polymers
We address the "Additive Equivalence" discovered by Virk and coworkers: drag
reduction affected by flexible and rigid rodlike polymers added to turbulent
wall-bounded flows is limited from above by a very similar Maximum Drag
Reduction (MDR) asymptote. Considering the equations of motion of rodlike
polymers in wall-bounded turbulent ensembles, we show that although the
microscopic mechanism of attaining the MDR is very different, the macroscopic
theory is isomorphic, rationalizing the interesting experimental observations.Comment: 8 pages, PRE, submitte
WARNING: Physics Envy May Be Hazardous To Your Wealth!
The quantitative aspirations of economists and financial analysts have for
many years been based on the belief that it should be possible to build models
of economic systems - and financial markets in particular - that are as
predictive as those in physics. While this perspective has led to a number of
important breakthroughs in economics, "physics envy" has also created a false
sense of mathematical precision in some cases. We speculate on the origins of
physics envy, and then describe an alternate perspective of economic behavior
based on a new taxonomy of uncertainty. We illustrate the relevance of this
taxonomy with two concrete examples: the classical harmonic oscillator with
some new twists that make physics look more like economics, and a quantitative
equity market-neutral strategy. We conclude by offering a new interpretation of
tail events, proposing an "uncertainty checklist" with which our taxonomy can
be implemented, and considering the role that quants played in the current
financial crisis.Comment: v3 adds 2 reference
Proactive, boundaryless, and confident graduates entering the labour market: does need for cognitive closure play a role as a moderator?
The university to work transition is a crucial and delicate stage for graduates, as it involves an essential change of role. Previous studies have shown that proactive personality, boundaryless mind-set and career self-efficacy are critical variables for a successful labour market integration/entry. This study analyzes the involvement of the need for cognitive closure as an individual variable that can both favor and hinder this process. Specifically, this work examines the moderating role of need for cognitive closure in the indirect association between proactive personality and career self-efficacy through boundaryless mind-set in a sample of 762 adults enrolled at the university or recently graduated therein. Results showed that career self-efficacy was positively predicted by proactive personality and boundaryless mind-set. Although a significant indirect effect was present thus confirming our first hypothesis, it did not vary depending on the need for cognitive closure proving that need for cognitive closure did not act as a moderator of this indirect association, hence not supporting our second hypothesis. These findings were discussed concerning the complexity of
students’ choices in transition and the nature of the information processing process needed for those choices
High-energy scissors mode
All the orbital M1 excitations, at both low and high energies, obtained from
a rotationally invariant QRPA, represent the fragmented scissors mode. The
high-energy M1 strength is almost purely orbital and resides in the region of
the isovector giant quadrupole resonance. In heavy deformed nuclei the
high-energy scissors mode is strongly fragmented between 17 and 25 MeV (with
uncertainties arising from the poor knowledge of the isovector potential). The
coherent scissors motion is hindered by the fragmentation and for single transitions in this region. The cross
sections for excitations above 17 MeV are one order of magnitude larger for E2
than for M1 excitations even at backward angles.Comment: 20 pages in RevTEX, 5 figures (uuencoded,put with 'figures') accepted
for publication in Phys.Rev.
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