6,455 research outputs found
Phenomenological constraints on minimally coupled exotic lepton triplets
By introducing a set of new triplet leptons (with nonzero hypercharge) that
can Yukawa couple to their Standard Model counterparts, new sources of
tree-level flavor changing currents are induced via mixing. In this work, we
study some of the consequences of such new contributions on processes such as
the leptonic decays of gauge bosons, and which violate lepton flavor, and mu-e conversion in
atomic nuclei. Constraints are then placed on the parameters associated with
the exotic triplets by invoking the current low-energy experimental data.
Moreover, the new physics contribution to the lepton anomalous magnetic moments
is calculated.Comment: 17 pages, 1 figure, 2 tables (REVTeX4.1); v2: refs added, to appear
in PR
Memory difference control of unknown unstable fixed points: Drifting parameter conditions and delayed measurement
Difference control schemes for controlling unstable fixed points become
important if the exact position of the fixed point is unavailable or moving due
to drifting parameters. We propose a memory difference control method for
stabilization of a priori unknown unstable fixed points by introducing a memory
term. If the amplitude of the control applied in the previous time step is
added to the present control signal, fixed points with arbitrary Lyapunov
numbers can be controlled. This method is also extended to compensate arbitrary
time steps of measurement delay. We show that our method stabilizes orbits of
the Chua circuit where ordinary difference control fails.Comment: 5 pages, 8 figures. See also chao-dyn/9810029 (Phys. Rev. E 70,
056225) and nlin.CD/0204031 (Phys. Rev. E 70, 046205
Quantum Hall Effect and Quantum Point Contact in Bilayer-Patched Epitaxial Graphene
We study an epitaxial graphene monolayer with bilayer inclusions via
magnetotransport measurements and scanning gate microscopy at low temperatures.
We find that bilayer inclusions can be metallic or insulating depending on the
initial and gated carrier density. The metallic bilayers act as equipotential
shorts for edge currents, while closely spaced insulating bilayers guide the
flow of electrons in the monolayer constriction, which was locally gated using
a scanning gate probe.Comment: 5 pages, 5 figure
A new neurosurgical tool incorporating differential geometry and cellular automata techniques
Using optical coherence imaging, it is possible to visualize seizure progression intraoperatively. However, it is difficult to pinpoint an exact epileptic focus. This is crucial in attempts to minimize the amount of resection necessary during surgical therapeutic interventions for epilepsy and is typically done approximately from visual inspection of optical coherence imaging stills. In this paper, we create an algorithm with the potential to pinpoint the source of a seizure from an optical coherence imaging still. To accomplish this, a grid is overlaid on optical coherence imaging stills. This then serves as a grid for a two-dimensional cellular automation. Each cell is associated with a Riemannian curvature tensor representing the curvature of the brain's surface in all directions for a cell. Cells which overlay portions of the image which show neurons that are firing are considered "depolarized"
Seasonal and spatial dynamics of the primary vector of plasmodium knowlesi within a major transmission focus in Sabah, Malaysia
Background
The simian malaria parasite Plasmodium knowlesi is emerging as a public health problem in Southeast Asia, particularly in Malaysian Borneo where it now accounts for the greatest burden of malaria cases and deaths. Control is hindered by limited understanding of the ecology of potential vector species.
Methodology/Principal Findings
We conducted a one year longitudinal study of P. knowlesi vectors in three sites within an endemic area of Sabah, Malaysia. All mosquitoes were captured using human landing catch. Anopheles mosquitoes were dissected to determine, oocyst, sporozoites and parous rate. Anopheles balabacensis is confirmed as the primary vector of. P. knowlesi (using nested PCR) in Sabah for the first time. Vector densities were significantly higher and more seasonally variable in the village than forest or small scale farming site. However An. balabacensis survival and P. knowlesi infection rates were highest in forest and small scale farm sites. Anopheles balabacensis mostly bites humans outdoors in the early evening between 1800 to 2000hrs.
Conclusions/Significance
This study indicates transmission is unlikely to be prevented by bednets. This combined with its high vectorial capacity poses a threat to malaria elimination programmes within the region.
Author Summary
The first natural infection of Plasmodium knowlesi was reported 40 years ago. At that time it was perceived that the infection would not affect humans. However, now P. knowlesi is the predominant malaria species (38% of the cases) infecting people in Malaysia and is a notable obstacle to malaria elimination in the country. Plasmodium knowlesi has also been reported from all countries in Southeast Asia with the exception of Lao PDR and Timor Leste. In Sabah, Malaysian Borneo cases of human P. knowlesi are increasing. Thus, a comprehensive understanding of the bionomics of the vectors is required so as to enable proper control strategies. Here, we conducted a longitudinal study in Kudat district, Sabah, to determine and characterize the vectors of P. knowlesi within this transmission foci. Anopheles balabacensis was the predominant mosquito in all study sites and is confirmed as vector for P. knowlesi and other simian malaria parasites. The peak biting time was in the early part of the evening between1800 to 2000. Thus, breaking the chain of transmission is an extremely challenging task for the malaria elimination programme
Multilingual advertising in the linguistic landscape of Seoul
This study examines commercial signs in arguably the two most visited tourism districts in Seoul, namely Myeongdong and Insadong. It focuses on beauty and food businesses and analyzes featured languages and their content and roles in signage. This article argues that business types, specialized marketing focus, and intended sales pitch influence business owners’ linguistic choices. The findings of the study suggest that the beauty industry relies heavily on English in general, but the power of K‐Beauty popularized by ‘Hallyu’ (The Korean Wave) beyond Korea inevitably invites linguistic accommodation in the form of using Chinese and Japanese. In general, the business category of beauty features a more prevalent use of English than the gastronomic business in this study. Moreover, as an area specializing in traditions and cultural heritage, Insadong shows more signs exclusively in Korean than in Myeongdong.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151302/1/weng12427_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151302/2/weng12427.pd
Bifurcations, Chaos, Controlling and Synchronization of Certain Nonlinear Oscillators
In this set of lectures, we review briefly some of the recent developments in
the study of the chaotic dynamics of nonlinear oscillators, particularly of
damped and driven type. By taking a representative set of examples such as the
Duffing, Bonhoeffer-van der Pol and MLC circuit oscillators, we briefly explain
the various bifurcations and chaos phenomena associated with these systems. We
use numerical and analytical as well as analogue simulation methods to study
these systems. Then we point out how controlling of chaotic motions can be
effected by algorithmic procedures requiring minimal perturbations. Finally we
briefly discuss how synchronization of identically evolving chaotic systems can
be achieved and how they can be used in secure communications.Comment: 31 pages (24 figures) LaTeX. To appear Springer Lecture Notes in
Physics Please Lakshmanan for figures (e-mail: [email protected]
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