12,499 research outputs found
Microparticle Vaccines Against Toxoplasma gondii
Significant information indicates that future investigations on Toxoplasma vaccine development have to include adjuvants for enhancing protective immunity against Toxoplasma gondii. Especially, safe and effective adjuvants capable of fulfilling Th1âdependent cellâmediated immunity appear to be more likely to be allowed to use for anti Toxoplasma vaccine development. Recently, biodegradable and biocompatible polymers, such as poly (lactideâcoâglycolide) (PLG) polymers, have been utilized as safe and efficacious adjuvants to encapsulate antigens for producing longâterm release microparticleâbased vaccines. PLG microencapsulation allows the sustained release of antigens and facilitates antigen uptake via antigenâpresenting cells (APCs) to favorably generate Th1 cellâmediated immunity, which is required for the prevention of T. gondii infection. In our recent work, recombinant surface antigens (rSAGs), including rSAG1, rSAG2, and rSAG1/2, have been, respectively, encapsulated with the PLG polymer for production of PLGâencapsulated rSAG1 (PLGârSAG1), PLGâencapsulated rSAG2 (PLGârSAG2), or PLGâencapsulated rSAG1/2 (PLGârSAG1/2) microparticles. This chapter describes adjuvant effect of PLG microparticles, controlled release of PLG microparticles, PLG microparticlesâimmune system interaction, Toxoplasma SAGâloaded PLG microparticles, protective immunity by Toxoplasma SAGâloaded PLG microparticles, and future prospects. PLG microparticle vaccines would be advantageous for their application in the development of longâlasting vaccines against T. gondii for future use in humans and animals
Affleck-Dine Baryogenesis, Split Supersymmetry, and Inflation
It is shown that, in the context of split supersymmetry, a simple model with
a single complex scalar field can produce chaotic inflation and generate the
observed amount of baryon asymmetry via the Affleck-Dine mechanism. While the
inflaton quantum fluctuations give rise to curvature perturbation, we show that
quantum fluctuations of the phase of the scalar field can produce baryonic
isocurvature perturbation. Combining with constraints from WMAP data, all
parameters in the model can be determined to within a narrow range.Comment: version accepted for publication in PR
Occlusion of acute distal brachial, proximal radial and ulnar arteries in a young thrower
SummaryAcute arterial occlusion, a rare condition in throwers, requires early detection and treatment for avoiding further complications. Thus far, no study has mentioned the occurrence of distal brachial, proximal radial, and ulnar artery occlusion in baseball players. An adolescent baseball pitcher presented with acute occlusion of the distal brachial, proximal radial, or ulnar artery. The patient complained of a cold sensation in the hand, wrist, and distal forearm. On physical examination, decreased surface skin temperature, and no radial pulse in the wrist suggested arterial occlusion. Emergency angiography validated the clinical suspicion, and identified the arteries and sites of vascular occlusion. Surgery was performed to alleviate the occlusions, thereby resolving the preoperative complaints and abnormal findings. Furthermore, postoperative magnetic resonance imaging of the shoulder and elbow joint was conducted to determine the causes of arterial occlusion. The patient resumed pitching 4 months postoperatively, and has remained active and symptom free. Magnetic resonance imaging examination revealed no vascular abnormalities or bony or soft tissue in the shoulder or elbow region. With early detection and treatment, a favorable prognosis can be achieved in baseball pitchers with acute upper extremity arterial occlusion so that their pitching career is not jeopardized
Achieving minimum-error discrimination of an arbitrary set of laser-light pulses
Laser light is widely used for communication and sensing applications, so the
optimal discrimination of coherent states--the quantum states of light emitted
by a laser--has immense practical importance. However, quantum mechanics
imposes a fundamental limit on how well different coher- ent states can be
distinguished, even with perfect detectors, and limits such discrimination to
have a finite minimum probability of error. While conventional optical
receivers lead to error rates well above this fundamental limit, Dolinar found
an explicit receiver design involving optical feedback and photon counting that
can achieve the minimum probability of error for discriminating any two given
coherent states. The generalization of this construction to larger sets of
coherent states has proven to be challenging, evidencing that there may be a
limitation inherent to a linear-optics-based adaptive measurement strategy. In
this Letter, we show how to achieve optimal discrimination of any set of
coherent states using a resource-efficient quantum computer. Our construction
leverages a recent result on discriminating multi-copy quantum hypotheses
(arXiv:1201.6625) and properties of coherent states. Furthermore, our
construction is reusable, composable, and applicable to designing
quantum-limited processing of coherent-state signals to optimize any metric of
choice. As illustrative examples, we analyze the performance of discriminating
a ternary alphabet, and show how the quantum circuit of a receiver designed to
discriminate a binary alphabet can be reused in discriminating multimode
hypotheses. Finally, we show our result can be used to achieve the quantum
limit on the rate of classical information transmission on a lossy optical
channel, which is known to exceed the Shannon rate of all conventional optical
receivers.Comment: 9 pages, 2 figures; v2 Minor correction
SIMP (Strongly Interacting Massive Particle) Search
We consider laboratory experiments that can detect stable, neutral strongly
interacting massive particles (SIMPs). We explore the SIMP annihilation cross
section from its minimum value (restricted by cosmological bounds) to the barn
range, and vary the mass values from a GeV to a TeV. We also consider the
prospects and problems of detecting such particles at the Tevatron.Comment: Latex. 7 pages, 1 eps figure. Proceedings to the 4th UCLA Symposium
on Dark Matter DM2000, Marina del Rey, CA, USA, Feb. 23-25, 200
Lorentz violation and the proper-time method
In this paper, we apply the proper-time method to generate the
Lorentz-violating Chern-Simons terms in the four-dimensional Yang-Mills and
non-linearized gravity theories. It is shown that the coefficient of the
induced Chern-Simons term is finite but regularization dependent.Comment: 11 pages, Revtex
Reconstruction of plasma density profiles by measuring spectra of radiation emitted from oscillating plasma dipoles
We suggest a new method for characterising non-uniform density distributions of plasma by measuring the spectra of radiation emitted from a localised plasma dipole oscillator excited by colliding electromagnetic pulses. The density distribution can be determined by scanning the collision point in space. Two-dimensional particle-in-cell simulations demonstrate the reconstruction of linear and nonlinear density profiles corresponding to laser-produced plasma. The method can be applied to a wide range of plasma, including fusion and low temperature plasmas. It overcomes many of the disadvantages of existing methods that only yield average densities along the path of probe pulses, such as interferometry and spectroscopy
A Comparative Study of Pentaquark Interpolating Currents
In a diquark-diquark-antiquark picture of pentaquarks, we use two
interpolating currents to calculate the mass of the recently measured
state in the framework of QCD sum rules. We show that, even though
yielding similar values for (and close to the experimental
value), these currents differ from each other in what concerns the strength of
the pole, convergence of the OPE and sensitivity to the continuum threshold
parameter.Comment: 19 pages, 8 figures, replaced version accepted for publication in
Phys. Lett.
IMAGE-BASED MEASUREMENT AND BIOMECHANICAL ANALYSIS OF THE KNEE JOINT DURING FUNCTIONAL ACTIVITIES
A new approach based on the integration of medical image-based measurement techniques, infrared stereophotogrammetry and finite element modelling (FEM) was developed for comprehensive subject-specific biomechanical analyses of the knee joint during weight-bearing functional activities including cycling. The medical image-based methods include digitally reconstructed radiograph (DRR) based 3D fluoroscopy methods, and a new slice-to-volume registration method using FLASH MRI for the real-time measurement of the 3D kinematics of the knee in vivo. With the new approach, the soft tissue artefacts associated with skin marker-based stereophotogrammetry and their effects on the calculated biomechanical variables were also investigated
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