723 research outputs found
Representations of the Weyl group and Wigner functions for SU(3)
Bases for SU(3) irreps are constructed on a space of three-particle tensor
products of two-dimensional harmonic oscillator wave functions. The Weyl group
is represented as the symmetric group of permutations of the particle
coordinates of these space. Wigner functions for SU(3) are expressed as
products of SU(2) Wigner functions and matrix elements of Weyl transformations.
The constructions make explicit use of dual reductive pairs which are shown to
be particularly relevant to problems in optics and quantum interferometry.Comment: : RevTex file, 11 pages with 2 figure
Penning traps with unitary architecture for storage of highly charged ions
Penning traps are made extremely compact by embedding rare-earth permanent
magnets in the electrode structure. Axially-oriented NdFeB magnets are used in
unitary architectures that couple the electric and magnetic components into an
integrated structure. We have constructed a two- magnet Penning trap with
radial access to enable the use of laser or atomic beams, as well as the
collection of light. An experimental apparatus equipped with ion optics is
installed at the NIST electron beam ion trap (EBIT) facility, constrained to
fit within 1 meter at the end of a horizontal beamline for transporting highly
charged ions. Highly charged ions of neon and argon, extracted with initial
energies up to 4000 eV per unit charge, are captured and stored to study the
confinement properties of a one-magnet trap and a two-magnet trap. Design
considerations and some test results are discussed
Knowledge and Awareness Among Patients with Chronic Kidney Disease Stage 3
Knowledge is a prerequisite for changing behavior, and is useful for improving outcomes and reducing mortality rates in patients diagnosed with chronic kidney disease (CKD). The purpose of this article is to describe baseline CKD knowledge and awareness obtained as part of a larger study testing the feasibility of a self-management intervention. Thirty patients were recruited who had CKD Stage 3 with coexisting diabetes and hypertension. Fifty-four percent of the sample were unaware of their CKD diagnosis. Participants had a moderate amount of CKD knowledge. This study suggests the need to increase knowledge in patients with CKD Stage 3 to aid in slowing disease progression
Folding-competent and folding-defective forms of Ricin A chain have different fates following retrotranslocation from the endoplasmic reticulum
We report that a toxic polypeptide retaining the potential to refold upon dislocation from the endoplasmic reticulum (ER)
to the cytosol (ricin A chain; RTA) and a misfolded version that cannot (termed RTAÎ), follow ER-associated degradation
(ERAD) pathways in Saccharomyces cerevisiae that substantially diverge in the cytosol. Both polypeptides are dislocated
in a step mediated by the transmembrane Hrd1p ubiquitin ligase complex and subsequently degraded. Canonical
polyubiquitylation is not a prerequisite for this interaction because a catalytically inactive Hrd1p E3 ubiquitin ligase
retains the ability to retrotranslocate RTA, and variants lacking one or both endogenous lysyl residues also require the
Hrd1p complex. In the case of native RTA, we established that dislocation also depends on other components of the
classical ERAD-L pathway as well as an ongoing ERâGolgi transport. However, the dislocation pathways deviate
strikingly upon entry into the cytosol. Here, the CDC48 complex is required only for RTAÎ, although the involvement of
individual ATPases (Rpt proteins) in the 19S regulatory particle (RP) of the proteasome, and the 20S catalytic chamber
itself, is very different for the two RTA variants. We conclude that cytosolic ERAD components, particularly the
proteasome RP, can discriminate between structural features of the same substrate
The functional interactome landscape of the human histone deacetylase family
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102187/1/msb201326-sup-0001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102187/2/msb201326.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102187/3/msb201326.reviewer_comments.pd
A complementarity-based approach to phase in finite-dimensional quantum systems
We develop a comprehensive theory of phase for finite-dimensional quantum
systems. The only physical requirement we impose is that phase is complementary
to amplitude. To implement this complementarity we use the notion of mutually
unbiased bases, which exist for dimensions that are powers of a prime. For a
d-dimensional system (qudit) we explicitly construct d+1 classes of maximally
commuting operators, each one consisting of d-1 operators. One of this class
consists of diagonal operators that represent amplitudes (or inversions). By
the finite Fourier transform, it is mapped onto ladder operators that can be
appropriately interpreted as phase variables. We discuss the examples of qubits
and qutrits, and show how these results generalize previous approaches.Comment: 6 pages, no figure
SU(N)-symmetric quasi-probability distribution functions
We present a set of N-dimensional functions, based on generalized
SU(N)-symmetric coherent states, that represent finite-dimensional Wigner
functions, Q-functions, and P-functions. We then show the fundamental
properties of these functions and discuss their usefulness for analyzing
N-dimensional pure and mixed quantum states.Comment: 16 pages, 2 figures. Updated text to reflect referee comment
Multicomplementary operators via finite Fourier transform
A complete set of d+1 mutually unbiased bases exists in a Hilbert spaces of
dimension d, whenever d is a power of a prime. We discuss a simple construction
of d+1 disjoint classes (each one having d-1 commuting operators) such that the
corresponding eigenstates form sets of unbiased bases. Such a construction
works properly for prime dimension. We investigate an alternative construction
in which the real numbers that label the classes are replaced by a finite field
having d elements. One of these classes is diagonal, and can be mapped to
cyclic operators by means of the finite Fourier transform, which allows one to
understand complementarity in a similar way as for the position-momentum pair
in standard quantum mechanics. The relevant examples of two and three qubits
and two qutrits are discussed in detail.Comment: 15 pages, no figure
Changes in physical education teachersâ beliefs regarding motivational strategies: A quasi-experimental study
Abstract
Physical education teachers use motivational strategies that can (positively or negatively) affect their studentsâ level of motivation and engagement. Indeed, according to their experiences and beliefs, some teachers may focus on strategies that thwart, rather than support, studentsâ psychological needs (autonomy, competence, and relatedness). Effective professional development represents an excellent opportunity to help teachers use research-supported motivational strategies. Therefore, this study aimed to discover if attendance at a 2-day training course could positively affect PE teachersâ beliefs regarding empowering motivational strategies. Specifically, 11 PE teachers (experimental group = 6 [attending the training]; control group = 5 [no training]) from primary school (n = 6) and secondary school (n = 5) expressed their beliefs (effectiveness, feasibility, and normality) regarding 31 empowering motivational strategies proposed during training at the beginning (October) and the end (April) of the school year. Results of the Wilcoxon signed-rank test for related samples indicated no significant differences for the belief regarding effectiveness in either group. However, some positive significant changes (p †.05) occurred in the experimental group for two motivational strategies supporting studentsâ need for autonomy and one supporting their need for competence. Given the small sample, positive trends (p †.10) are also considered results of interest. In conclusion, the training appears likely to impact teachersâ beliefs. However, future professional development should provide additional feedback and follow-up time with teachers during experimentation with students to allow teachers to refine their understanding and use of the motivational strategies proposed
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