7,351 research outputs found
Quantum walk-based search and centrality
We study the discrete-time quantum walk-based search for a marked vertex on a
graph. By considering various structures in which not all vertices are
equivalent, we investigate the relationship between the successful search
probability and the position of the marked vertex, in particular its
centrality. We find that the maximum value of the search probability does not
necessarily increase as the marked vertex becomes more central and we
investigate an interesting relationship between the frequency of the successful
search probability and the centrality of the marked vertex.Comment: 29 pages, 17 figure
Buprenorphine added on brief cognitive behavioral therapy for treatment of methamphetamine use disorder
Background: Methamphetamine (MA) use remains a major public health concern around the world. Recent findings suggest that buprenorphine may be helpful for cocaine use reduction. Moreover, animal studies described reduced dopamine peak effect following MA use, due to the administration of low dose buprenorphine.
Objectives: This study examined the effectiveness of buprenorphine with brief cognitive behavioral therapy on MA use disorder.
Methods: The study was conducted in an outpatient substance abuse treatment center in Qazvin, Iran. Nineteen MA users received buprenorphine for 24 weeks combined with brief cognitive behavioral therapy in an outpatient substance abuse treatment program, three times per week, as a before and after non - randomization study. Clinical outcomes included treatment retention, MA use, degree of MA dependency and craving, quality of life, cognitive abilities questionnaire, addiction severity and also adverse events. Data was analyzed by performing repeated measures analysis and the Friedman test for nonparametric variables.
Results: Fifteen participants completed the study during six months and frequency of MA use was significantly decreased at 24 weeks (P < 0.001). There were also significant reductions in craving (P < 0.001), degree of MA dependence (P < 0.001), and improvements in quality of life, cognitive ability, and some subscales of addiction severity.
Conclusions: The results of this preliminary clinical study demonstrated that buprenorphine could potentially attenuate MA craving and alternate rewarding effects of MA and had promising effects on cognitive impairment. Furthermore, buprenorphine can be considered as a harm reduction intervention in some communities, in which the people, as a result of cultural beliefs, do not accept a therapy, which only consists of counseling and no medications
Null Branes in Curved Backgrounds
We consider null bosonic p-branes in curved space-times. Some exact solutions
of the classical equations of motion and of the constraints for the null
membrane in general stationary, axially symmetrical, four dimensional, gravity
background are found.Comment: 19 pages, LaTeX, no figures. Extended version. To appear in Phys.
Rev.
Gravitational Larmor formula in higher dimensions
The Larmor formula for scalar and gravitational radiation from a pointlike
particle is derived in any even higher-dimensional flat spacetime. General
expressions for the field in the wave zone and the energy flux are obtained in
closed form. The explicit results in four and six dimensions are used to
illustrate the effect of extra dimensions on linear and uniform circular
motion. Prospects for detection of bulk gravitational radiation are briefly
discussed.Comment: 5 pages, no figure
Long-term Follow Up of Van Nes Rotationplasty for Proximal Focal Femoral Deficiency
Proximal focal femoral deficiency (PFFD) is a congenital anomaly that presents challenges for orthopaedic and prosthetic management. The Van Nes rotationplasty is one treatment in which the extremity is surgically rotated to utilize the ankle and foot as a functional knee joint in a prosthesis. The purpose of this study is to determine the long-term functional and quality of life (QOL) outcomes for individuals who have undergone rotationplasty surgery for congenital PFFD compared to age and gender matched controls
Long-term Follow up of Van Nes Rotationplasty for Congenital Proximal Focal Femoral Deficiency [Proceedings]
INTRODUCTIONProximal focal femoral deficiency (PFFD) is a congenital anomaly that presents challenges for orthopaedic and prosthetic management. The Van Nes rotationplasty is one treatment in which the extremity is surgically rotated to utilize the ankle and foot as a functional knee joint in a prosthesis. The purpose of this study is to determine the long-term functional and quality of life (QOL) outcomes for individuals who have undergone rotationplasty surgery for congenital PFFD compared to age and gender matched controls. METHODSThis prospective study had 12 prosthetic participants (PFFD Group: 8 M, 4F, age range 16-57 years) average 31.6±13.5 years and 12 control participants (Control Group: 8M, 4F) with an average age 32.6±14.1 years. Participants completed the following outcome questionnaires: SF-36, Revised-Faces Pain Scale, Harris Hip Score, Oswestry back pain score; and underwent lower extremity range of motion (ROM), hand held dynamometry, gait analysis, computerized dynamic posturography and Timed ‘Up& Go’ (TUG) testing. The PFFD Group also completed the Prosthetic Evaluation Questionnaire© (PEQ). The Wilcoxon Signed rank test was used to statistically compare each PFFD Group participant to the matched Control Group participant with values statistically significant at p\u3c 0.0123. RESULTSParticipants had rotationplasty performed at an average age of 6.5±3.9 years with follow up testing done 25.1±11.2 years later. All adult subjects were working full time in a variety of manual and office/desk jobs. No significant issues were seen for body image. Pain: The PFFD and Control Groups both reported similar low back pain with 6.8±9.7% and 7.0±13.0% disability respectively on the Oswestry back pain questionnaire. On the day of testing, only one PFFD participant reported mild low back pain on the Revised- Faces Pain Scale. The average Harris Hip Score for the PFFD Group was 92.7±9.2 out of 100, indicating excellent outcome. Two participants reported pain on their non-prosthetic hip. ROM: The PFFD Group showed significantly decreased hip flexion and ankle dorsiflexion, and increased ankle plantarflexion strength on the prosthetic side compared to the Control Group. The PFFD Group had significantly greater ankle abduction strength on their non-prosthetic side compared to the Control Group. Strength: The PFFD Group demonstrated significantly weaker hip flexion, hip abduction and ankle plantarflexion on the prosthetic side compared to the Control Group. TUG: The PFFD Group scored an average of 8.5±1.6 seconds on the TUG, demonstrating a low fall risk. The Control Group scored significantly lower with an average of 6.5 ±1.0 seconds. SF-36: There were no significant differences between the groups in overall health and well-being. PEQ©: The PFFD Group scored lower in areas of satisfaction, appearance, and sounds of the prosthesis. However, participants reported that others perceived them well and they did not see themselves as a social burden. Gait Analysis: Temporal-spatial gait parameters for the PFFD Group demonstrated significant decrease in cadence, stride time, opposite foot off, single support and walking speed compared to Control Group. Posturography: The PFFD Group showed significant decrease in symmetry in stance, as well as a decrease in end point and maximum excursion in limits of stability testing compared to the Control Group. DISCUSSION AND CONCLUSIONOverall, long-term follow up of teens and adults who underwent Van Nes rotationplasty showed that they maintained a high level of function, participation and QOL. They did present with significant differences in temporal spatial and posturography parameters compared to the Control Group
The implications of noninertial motion on covariant quantum spin
It is shown that the Pauli-Lubanski spin vector defined in terms of
curvilinear co-ordinates does not satisfy Lorentz invariance for spin-1/2
particles in noninertial motion along a curved trajectory. The possibility of
detecting this violation in muon decay experiments is explored, where the
noninertial contribution to the decay rate becomes large for muon beams with
large momenta and trajectories with radius of curvature approaching the muon's
Compton wavelength scale. A new spacelike spin vector is derived from the
Pauli-Lubanski vector that satisfies Lorentz invariance for both inertial and
noninertial motion. In addition, this spin vector suggests a generalization for
the classification of spin-1/2 particles, and has interesting properties that
are applicable for both massive and massless particles.Comment: REVTeX file; 7 pages; 2 figures; slightly revised with new abstract;
accepted for publication in Classical and Quantum Gravit
Long-term Follow up of Van Nes Rotationplasty for Congenital Proximal Focal Femoral Deficiency
Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency (PFFD). The lower limb is rotated to use the ankle and foot as a functional knee joint within a prosthesis. A small series of cases was investigated to determine the long-term outcome. At a mean of 21.5 years (11 to 45) after their rotationplasty, a total of 12 prosthetic patients completed the Short-Form (SF)-36, Faces Pain Scale-Revised, Harris hip score, Oswestry back pain score and Prosthetic Evaluation Questionnaires, as did 12 age- and gender-matched normal control participants. A physical examination and gait analysis, computerised dynamic posturography (CDP), and timed ‘Up & Go’ testing was also completed. Wilcoxon Signed rank test was used to compare each PFFD patient with a matched control participant with false discovery rate of 5%. There were no differences between the groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters in the PFFD group. Using CDP, the PFFD group had reduced symmetry in stance, and reduced end point and maximum excursions. Patients who had undergone Van Nes rotationplasty had a high level of function and quality of life at long-term follow-up, but presented with significant differences in gait and posture compared with the control group
Hadronic shift in pionic hydrogen
The hadronic shift in pionic hydrogen has been redetermined to be
\,eV by X-ray
spectroscopy of ground state transitions applying various energy calibration
schemes. The experiment was performed at the high-intensity low-energy pion
beam of the Paul Scherrer Institut by using the cyclotron trap and an
ultimate-resolution Bragg spectrometer with bent crystals.Comment: 10 pages, 6 figure
Reed-Muller codes for random erasures and errors
This paper studies the parameters for which Reed-Muller (RM) codes over
can correct random erasures and random errors with high probability,
and in particular when can they achieve capacity for these two classical
channels. Necessarily, the paper also studies properties of evaluations of
multi-variate polynomials on random sets of inputs.
For erasures, we prove that RM codes achieve capacity both for very high rate
and very low rate regimes. For errors, we prove that RM codes achieve capacity
for very low rate regimes, and for very high rates, we show that they can
uniquely decode at about square root of the number of errors at capacity.
The proofs of these four results are based on different techniques, which we
find interesting in their own right. In particular, we study the following
questions about , the matrix whose rows are truth tables of all
monomials of degree in variables. What is the most (resp. least)
number of random columns in that define a submatrix having full column
rank (resp. full row rank) with high probability? We obtain tight bounds for
very small (resp. very large) degrees , which we use to show that RM codes
achieve capacity for erasures in these regimes.
Our decoding from random errors follows from the following novel reduction.
For every linear code of sufficiently high rate we construct a new code
, also of very high rate, such that for every subset of coordinates, if
can recover from erasures in , then can recover from errors in .
Specializing this to RM codes and using our results for erasures imply our
result on unique decoding of RM codes at high rate.
Finally, two of our capacity achieving results require tight bounds on the
weight distribution of RM codes. We obtain such bounds extending the recent
\cite{KLP} bounds from constant degree to linear degree polynomials
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