6,431 research outputs found
Squeezed correlations of strange particle-antiparticles
Squeezed correlations of hadron-antihadron pairs are predicted to appear if
their masses are modified in the hot and dense medium formed in high energy
heavy ion collisions. If discovered experimentally, they would be an
unequivocal evidence of in-medium mass shift found by means of hadronic probes.
We discuss a method proposed to search for this novel type of correlation,
illustrating it by means of D_s-mesons with in-medium shifted masses. These
particles are expected to be more easily detected and identified in future
upgrades at RHIC.Comment: 6 pages, 3 figures with parts a) and b), SQM 2009 contribution; added
acknowledgmen
Creating Equitable Access Pathways For All Students In South Carolina? A Study Of SC International Baccalaureate Diploma Programs
This case study adds insight to the idea of equitable access as it relates to advanced coursework available to students in public high schools in South Carolina. The International Baccalaureate Diploma Program (IBDP) has become a viable choice since secondary-level magnet programs in SC have taken root for over thirty years. The IBDP originally developed in SC to attract the global elite, however in the recent decade, the IBDP has morphed into a program meant for all students. The concept of IB for All is marketed as a college readiness program within South Carolina IBDP schools. Access is multidimensional; it includes educational policies, leadership, and practices heavily shaped by the local-school policy actors. However, my analysis demonstrates that access is also a socio-cultural construct, formulated, or redefined, year after year in schools. The perspectives of IBDP coordinators from across the state of SC generated the central insights analyzed in this dissertation. Based on their responses to an initial questionnaire, coordinators were interviewed individually providing rich details about the patterns of change throughout the state. Then, focus groups and further one-on-one interviews were conducted with other key participants providing an historic and broader perspective from the state and national levels. This inquiry adds insight to the idea of what access to the IBDP looks like in relation to school reform, choice, integration, and giftedness. This case study presents the multidimensionality of access and will inform choice implementation through leveling the field for equitable opportunities for SC students to choose the IBDP option for college readiness
Testing the Resolving Power of 2-D K^+ K^+ Interferometry
Adopting a procedure previously proposed to quantitatively study
two-dimensional pion interferometry, an equivalent 2-D chi^2 analysis was
performed to test the resolving power of that method when applied to less
favorable conditions, i.e., if no significant contribution from long lived
resonances is expected, as in kaon interferometry. For that purpose, use is
made of the preliminary E859 K^+ K^+ interferometry data from Si+Au collisions
at 14.6 AGeV/c. As expected, less sensitivity is achieved in the present case,
although it still is possible to distinguish two distinct decoupling
geometries. The present analysis seems to favor scenarios with no resonance
formation at the AGS energy range, if the preliminary K^+ K^+ data are
confirmed. The possible compatibility of data with zero decoupling proper time
interval, conjectured by the 3-D experimental analysis, is also investigated
and is ruled out when considering more realistic dynamical models with
expanding sources. These results, however, clearly evidence the important
influence of the time emission interval on the source effective transverse
dimensions. Furthermore, they strongly emphasize that the static Gaussian
parameterization, commonly used to fit data, cannot be trusted under more
realistic conditions, leading to distorted or even wrong interpretation of the
source parameters!Comment: 11 pages, RevTeX, 4 Postscript figures include
Optimizing an Actuator Array for the Control of Multi-Frequency Noise in Aircraft Interiors
Techniques developed for selecting an optimized actuator array for interior noise reduction at a single frequency are extended to the multi-frequency case. Transfer functions for 64 actuators were obtained at 5 frequencies from ground testing the rear section of a fully trimmed DC-9 fuselage. A single loudspeaker facing the left side of the aircraft was the primary source. A combinatorial search procedure (tabu search) was employed to find optimum actuator subsets of from 2 to 16 actuators. Noise reduction predictions derived from the transfer functions were used as a basis for evaluating actuator subsets during optimization. Results indicate that it is necessary to constrain actuator forces during optimization. Unconstrained optimizations selected actuators which require unrealistically large forces. Two methods of constraint are evaluated. It is shown that a fast, but approximate, method yields results equivalent to an accurate, but computationally expensive, method
A novel method to detect translation of membrane proteins following microvesicle intercellular transfer of nucleic acids
© 2016 The Authors. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved. Microvesicles (MVs) serve as vectors of nucleic-acid dissemination and are important mediators of intercellular communication. However, the functionality of packaged nucleic acids on recipient cells following transfer of MV cargo has not been clearly elucidated. This limitation is attributed to a lack of methodology available in assessing protein translation following homotypic intercellular transfer of nucleic acids. Using surface peptide shaving we have demonstrated that MVs derived from human leukaemic cells transfer functional P-glycoprotein transcripts, conferring drug-efflux capacity to recipient cells. We demonstrate expression of newly synthesized protein using Western blot. Furthermore, we show functionality of translated P-gp protein in recipient cells using Calcein-AM dye exclusion assays on flow cytometry. Newly synthesized 170 kDa P-gp was detected in recipient cells after coculture with shaven MVs and these proteins were functional, conferring drug efflux. This is the first demonstration of functionality of transferred nucleic acids between human homotypic cells as well as the translation of the cancer multidrug-resistance protein in recipient cells following intercellular transfer of its transcript. This study supports the significant role of MV's in the transfer of deleterious traits in cancer populations and describes a new paradigm in mechanisms governing the acquisition of traits in cancer cell populations
Texture Evolution During Isothermal, Isostrain, and Isobaric Loading of Polycrystalline Shape Memory NiTi
In situ neutron diffraction was used to provide insights into martensite variant microstructures during isothermal, isobaric, and isostrain loading in shape memory NiTi. The results show that variant microstructures were equivalent for the corresponding strain, and more importantly, the reversibility and equivalency were immediately evident in variant microstructures that were first formed isobarically but then reoriented to near random self-accommodated microstructures following isothermal deformation. Variant microstructures formed isothermally were not significantly affected by a subsequent thermal cycle under constant strain. In all loading cases considered, the resulting variant microstructure correlated with strain and did not correlate with stress. Based on the ability to select a variant microstructure for a given strain despite thermomechanical loading history, the results demonstrated here can be obtained by following any sequence of thermomechanical loading paths over multiple cycles. Thus, for training shape memory alloys (repeating thermomechanical cycling to obtain the desired variant microstructure), optimal paths can be selected so as to minimize the number of training cycles required, thereby increasing the overall stability and fatigue life of these alloys in actuator or medical applications
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RADIATION ACCESS ZONE AND VENTILATION CONFINEMENT ZONE CRITERIA FOR THE MGR SURFACE FACILITIES
The objectives of this technical report are to: (1) Establish the criteria for Radiation Access Zone (RAZ) designation. (2) Establish the criteria for the Ventilation Confinement Zone (VCZ) designation. The scope will be to formulate the RAZ and VCZ zoning designation for the Monitored Geologic Repository (MGR) surface facilities and to apply the zoning designations to the current Waste Handling Building (WHB), Waste Treatment Building (WTB), and Carrier Preparation Building (CPB) configurations
Quantum corrections for pion correlations involving resonance decays
A method is presented to include quantum corrections into the calculation of
two-pion correlations for the case where particles originate from resonance
decays. The technique uses classical information regarding the space-time
points at which resonances are created. By evaluating a simple thermal model,
the method is compared to semiclassical techniques that assume exponential
decaying resonances moving along classical trajectories. Significant
improvements are noted when the resonance widths are broad as compared to the
temperature.Comment: 9 pages, 4 figure
A Preliminary Analysis of Anthropogenic and Natural Impacts on a Volcanic Lake Ecosystem in Southern Italy by UAV-Based Monitoring
Lakes play an important role in providing various ecosystem services. However, stressors such as climate change, land use, or land-cover change threaten the ecological functions of lakes. National and international legislations address these threats and establish consistent, long-term monitoring schemes. Remote sensing techniques based on the use of Unmanned Aerial Vehicles (UAV) have recently been demonstrated to provide accurate and low-cost spatio-temporal views for the assessment of the ecological status of aquatic ecosystems and the identification of areas at risk of contamination. Few studies have been carried out so far on the employment of these tools in the monitoring of lakes. Therefore, high-resolution UAV surveys were used to analyse and evaluate natural and anthropogenic impacts on the habitat status of a volcanic lake in a protected area. Five UAV flights took place during a year-long cycle (November 2020 to November 2021) in a volcanic lake located in southern Italy. For each flight performance, an orthomosaic of georeferenced RGB images was obtained, and the different features of interest were monitored and quantified using automated processing in a GIS environment. The UAV images made it possible not only to estimate the flooded shores but also to detect the impact of human-made structures and infrastructures on the lagoon environment. It has been possible to observe how the rapid changes in lake-water level have led to the submersion of about 90.000 m(2) of terrain in winter, causing the fragmentation and degradation of habitats, while the connectivity of the natural ecosystem has been threatened by the presence of the road around the lake. The proposed methodology is rather simple and easily replicable by decision makers and local administrators and can be useful for choosing the best restoration interventions
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