Comment to "Fine structure constant in the spacetime of a cosmic string"

In the paper Phys. Lett. B614 (2005), 140-142, F. Nasseri shows that the values of the fine structure constant reduces due to the presence of a cosmic string. In this comment I want to point out that this conclusion is not completely correct in the sense that the result obtained is valid only in a very special situation.Comment: Accepted for publication in Physics Letters

On the inexplicability of the implicit: differences in the information provided by implicit and explicit tests

Implicit measures are often preferred to overt questioning in many areas of psychology. Their covert nature allows them to circumvent conscious expectations and biases, theoretically providing more objective indicators of people's true attitudes and bel iefs. However, we argue that implicit and explicit measures tap into different memory systems, so that the interpretation of implicit measures is not as straightforward as the interpretation of explicit measures. We conducted an experiment investigating the relation between implicit and explicit measures of person impressions. The results demonstrate that a single stimulus can have opposite effects on implicit and explicit measures, supporting the theory that the measures reflect the contents of different memory systems. We suggest that implicit measures reflect simple associations stored in a "slow-learning" memory system, while explicit measures reflect a combination of these associations with contextually dependent memories stored in a "fast-binding" memory system

Self-energy and Self-force in the Space-time of a Thick Cosmic String

We calculate the self-energy and self-force for an electrically charged particle at rest in the background of Gott-Hiscock cosmic string space-time. We found the general expression for the self-energy which is expressed in terms of the $S$ matrix of the scattering problem. The self-energy continuously falls down outward from the string's center with maximum at the origin of the string. The self-force is repulsive for an arbitrary position of the particle. It tends to zero in the string's center and also far from the string and it has a maximum value at the string's surface. The plots of the numerical calculations of the self-energy and self-force are shown.Comment: 15 pages, 4 Postscript figures, ReVTe

Is null-point reconnection important for solar flux emergence?

The role of null-point reconnection in a 3D numerical MHD model of solar emerging flux is investigated. The model consists of a twisted magnetic flux tube rising through a stratified convection zone and atmosphere to interact and reconnect with a horizontal overlying magnetic field in the atmosphere. Null points appear as the reconnection begins and persist throughout the rest of the emergence, where they can be found mostly in the model photosphere and transition region, forming two loose clusters on either side of the emerging flux tube. Up to 26 nulls are present at any one time, and tracking in time shows that there is a total of 305 overall, despite the initial simplicity of the magnetic field configuration. We find evidence for the reality of the nulls in terms of their methods of creation and destruction, their balance of signs, their long lifetimes, and their geometrical stability. We then show that due to the low parallel electric fields associated with the nulls, null-point reconnection is not the main type of magnetic reconnection involved in the interaction of the newly emerged flux with the overlying field. However, the large number of nulls implies that the topological structure of the magnetic field must be very complex and the importance of reconnection along separators or separatrix surfaces for flux emergence cannot be ruled out.Comment: 26 pages, 12 figures. Added one referenc

Assistive devices, hip precautions, environmental modifications and training to prevent dislocation and improve function after hip arthroplasty (Review)

Background: Total hip arthroplasty (THA) is one of the most common orthopaedic operations performed worldwide. Painful osteoarthritis of the hip is the primary indication for THA. Following THA, people have conventionally been provided with equipment, such as raised toilet seats and chairs, and educated to avoid activities that could cause the hip joint to be in a position of flexion over 90 degrees, or adduction or rotation past the midline. These aspects of occupational therapy have been advocated to reduce the risks of prosthesis dislocation. However, the appropriateness of these recommendations has been questioned. Objectives: To assess the effects of provision of assistive devices, education on hip precautions, environmental modifications and training in activities of daily living (ADL) and extended ADL (EADL) for people undergoing THA. Search methods: We searched MEDLINE (1946 to April 2016), EMBASE (1947 to April 2016), the Cochrane Library including CENTRAL (Issue 4 of 12, 2016), Database of Reviews of Effects (DARE), Health Technology Assessment (HTA), Economic Evaluations Database (EED), CINAHL, PEDro and CIRRIE from inception to April 2016. In addition we checked Controlled Clinical Trials, Clinicaltrials.gov, the National Institutes of Health Trial Registry, theWorld Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and the OpenGrey database from inception to April 2016. Selection criteria: We included randomised controlled trials (RCTs), quasi-RCTs and cluster-RCTs that evaluated the effectiveness of the provision of assistive devices, education on hip precautions, environmental modifications, or training in ADL and EADL for people undergoing THA. The main outcomes of interest were pain, function, health-related quality of life (HRQOL), global assessment of treatment success, reoperation rate, hip dislocation and adverse events. Data collection and analysis: We used standard methodological procedures recognised by Cochrane. We conducted a systematic literature search using several databases and contacted corresponding authors, appraised the evidence using the Cochrane risk of bias tool, analysed the data using a narrative analysis approach (as it was not possible to conduct a meta-analysis due to heterogeneity in interventions), and interpreted all outcomes using the GRADE approach. Main results: We included three trials with a total of 492 participants who had received 530 THA. The evidence presented with a high risk of performance, detection and reporting bias. One study (81 participants) compared outcomes for participants randomised to the provision of hip precautions, equipment and functional restrictions versus no provision of hip precautions, equipment or functional restrictions. Due to the quality of evidence being very low, we are uncertain if the provision of hip precautions, equipment and functional restrictions improved function measured using the Harris Hip Score at 12 month follow-up, or health-related quality of life (HRQOL) measured by the Short Form-12 at four week follow-up, compared to not providing this. There were no incidences of hip dislocation or adverse events in either group during the initial 12 postoperative months. The study did not measure pain score, global assessment of treatment success or total adverse events. One study (265 participants; 303THAs) evaluated the provision of hip precautions with versus without the prescription of postoperative equipment and restrictions to functional activities. Due to the quality of evidence being very low, we are uncertain if perceived satisfaction in the rate of recovery differed in people who were not prescribed postoperative equipment and restrictions (135/151 satisfied) compared to those prescribed equipment and restrictions (113/152) (risk ratio (RR) 0.83, 95% confidence interval (CI) 0.75 to 0.93; 265 participants, one trial; number needed to treat for an additional beneficial outcome (NNTB) = 7). Due to the low quality evidence, we are uncertain if the incidence of hip dislocation differed between participants provided with hip precautions with (1/152) compared to without providing equipment or restrictions post-THA (0/151) (RR 2.98, 95% CI 0.12 to 72.59). The study did not measure pain, function, HRQOL, re-operation rates or total adverse events. One study (146 participants) investigated the provision of an enhanced postoperative education and rehabilitation service on hospital discharge to promote functional ADL versus a conventional rehabilitation intervention in the community. This study was of very low quality evidence. We were uncertain if the provision of enhanced postoperative education and rehabilitation improved function at six months follow-up, when assessed using the Objective and Subjective Functional Capability Index (146 participants, one trial; P > 0.05; no numerical results provided) compared to conventional rehabilitation. The study did not measure pain score, HRQOL, global assessment of treatment success, hip dislocation, re-operation rate or total adverse events. Authors’ conclusions: Very low quality evidence is available from single trials, thus we are uncertain if hip precautions with or without the addition of equipment and functional restrictions are effective in preventing dislocation and improving outcomes after THA. There is also insufficient evidence to support or refute the adoption of a postoperative community rehabilitation programme consisting of functional reintegration and education compared to conventional rehabilitation strategies based on functional outcomes. Further high-quality trials are warranted to assess the outcomes of different occupational therapy interventions both in the short and longer-term for those who undergo THA. An assessment of the impact of such interventions on pain and restriction on personal ADL, EADL and instrumental ADL is needed, and also of functional integration-type interventions rather than just hip precautions,equipment and restrictions

One Dimensional Chain with Long Range Hopping

The one-dimensional (1D) tight binding model with random nearest neighbor hopping is known to have a singularity of the density of states and of the localization length at the band center. We study numerically the effects of random long range (power-law) hopping with an ensemble averaged magnitude \expectation{|t_{ij}|} \propto |i-j|^{-\sigma} in the 1D chain, while maintaining the particle-hole symmetry present in the nearest neighbor model. We find, in agreement with results of position space renormalization group techniques applied to the random XY spin chain with power-law interactions, that there is a change of behavior when the power-law exponent $\sigma$ becomes smaller than 2

Proof of the Hyperplane Zeros Conjecture of Lagarias and Wang

We prove that a real analytic subset of a torus group that is contained in its image under an expanding endomorphism is a finite union of translates of closed subgroups. This confirms the hyperplane zeros conjecture of Lagarias and Wang for real analytic varieties. Our proof uses real analytic geometry, topological dynamics and Fourier analysis.Comment: 25 page

Phase mixing of standing Alfven waves with shear flows in solar spicules

Alfvenic waves are thought to play an important role in coronal heating and solar wind acceleration. Here we investigate the dissipation of such waves due to phase mixing at the presence of shear flow and field in the stratified atmosphere of solar spicules. The initial flow is assumed to be directed along spicule axis and to vary linearly in the x direction and the equilibrium magnetic field is taken 2-dimensional and divergence-free. It is determined that the shear flow and field can fasten the damping of standing Alfven waves. In spite of propagating Alfven waves, standing Alfven waves in Solar spicules dissipate in a few periods. As height increases, the perturbed velocity amplitude does increase in contrast to the behavior of perturbed magnetic field. Moreover, it should be emphasized that the stratification due to gravity, shear flow and field are the facts that should be considered in MHD models in spicules.Comment: Accepted for publication in Astrophysics & Space Scienc

Persistent Currents in 1D Disordered Rings of Interacting Electrons

We calculate the persistent current of 1D rings of spinless fermions with short-range interactions on a lattice with up to 20 sites, and in the presence of disorder, for various band fillings. We find that {\it both} disorder and interactions always decrease the persistent current by localizing the electrons. Away from half-filling, the interaction has a much stronger influence in the presence of disorder than in the pure case.Comment: Latex file, 11 pages, 5 figures available on request, Report LPQTH-93/1

Draft genome sequence of the bacteriophage vB_Eco_slurp01.

Bacteriophage vB_Eco_slurp01 was isolated from porcine feces using Escherichia coli MG1655 as a host. With a genome size of 348 kb, vB_Eco_slurp01 is one of the largest bacteriophages isolated to date