1,088 research outputs found
Stability of the Chari-Pressley-Loktev bases for local Weyl modules of
We prove stability of the Chari-Pressley-Loktev bases for natural inclusions
of local Weyl modules of the current algebra . These modules being
known to be Demazure submodules in the level 1 representations of the affine
Lie algebra , we obtain, by passage to the direct limit, bases
for the level 1 representations themselves.Comment: 20 pages; minor revision
Specific Antibodies to Recombinant Allergens of \u3cem\u3eAspergillus fumigatus\u3c/em\u3e in Cystic Fibrosis Patients with ABPA
Background
Aspergillus fumigatus, a widely distributed fungus, has been implicated in causing life threatening infections as well as severe asthma and allergic diseases in man. Allergic affliction like allergic bronchopulmonary aspergillosis (ABPA) is a disabling lung disease frequently seen in patients with asthma and cystic fibrosis. Immunodiagnosis of the former is comparatively easier due to the availability of purified antigens and sensitive methods. However, this is not true with cystic fibrosis patients where the prevalence of ABPA is fairly high and the morbidity and mortality are significant. Methods
In the present study, we have evaluated purified recombinant allergens from A. fumigatus, namely Asp f 1, f 2, f 3, f 4, and f 6 using ELISA and a semi-automated method (ImmunoCAP). We studied 17 patients each from cystic fibrosis with ABPA, and cystic fibrosis with asthma, 22 cystic fibrosis with no ABPA or asthma, and 11 age matched controls. Results
The results indicate that no antigen, antibody or method is capable of differentiating cystic fibrosis (CF) with ABPA from other CF patients, although some allergens showed strong reaction or showed more prevalence among the patients studied. Conclusion
When results of several allergens such as Asp f 1, f 2, f 3, f 4, and f 6 in their binding to IgA, IgG, and IgE antibodies were analyzed, a more strong discrimination of CF patients with ABPA was possible from the other groups studied
Effect of crystal structure and cationic order on phonon modes across ferroelectric phase transformation in Pb(Fe0.5-xScxNb0.5)O3 bulk ceramics
Pb(Fe0.5-xScxNb0.5)O3 [(PFSN) (0 ≤ x ≤ 0.5)] multiferroic relaxors were synthesized and the temperature dependence of phonon modes across ferroelectric to paraelectric transition was studied. With varying Sc content from x = 0 to 0.25 the structure remains monoclinic and with further addition (x = 0.3 - 0.5) the structure transforms into rhombohedral symmetry. Structural refinement studies showed that the change in crystal structure from monoclinic to rhombohedral symmetry involves a volume increment of 34-36%. Associated changes in the tolerance factor (1.024 ≤ t ≤ 0.976) and bond angles were observed. Structure assisted B′-B″ cation ordering was confirmed through the superlattice reflections in selected area electron diffraction (SAED) pattern of Pb(Sc0.5Nb0.5)O3 (x = 0.5). Cation ordering is also evident from the evolution of Pb-O phonon mode in Raman spectra of compositions with rhombohedral symmetry (x ≥ 0.3). The high temperature Raman scattering studies show that the B-localized mode [F1u, ∼250 cm−1] and BO6 octahedral rotational mode [F1g, ∼200 cm−1], both originating from polar nano regions (PNRs) behave like coupled phonon modes in rhombohedral symmetry. However, in monoclinic symmetry they behave independently across the transition. Softening of B localized mode across the transition followed by the hardening for all compositions confirms the diffusive nature of the ferroelectric transformation. The presence of correlation between the B localized and BO6 rotational modes introduces a weak relaxor feature for systems with rhombohedral symmetry in PFSN ceramics, which was confirmed from the macroscopic dielectric studies
Hype or Help? A Longitudinal Field Study of Virtual World Use for Team Collaboration
Despite increasing organizational interest and investment in virtual worlds (VWs), there is a lack of research on the benefits of VWs. When and how does the use of VW systems engender better organizational outcomes than traditional collaborative technologies? This paper investigates the value of VWs for team collaboration. Team collaboration is particularly relevant in studying VWs given the rich interactive nature of VWs and an increasing organizational reliance on virtual teamwork. To understand the value of VW use for team collaboration, we examine the relationship between a team’s disposition toward IT, their general disposition (personality) and VW use in influencing team cohesion and performance. We conducted a field study that compares two collaborative technology systems – one that is based on a traditional desktop metaphor and one that is grounded in the principles of a virtual world. We tracked the use of the systems for one year. We analyzed data at the team level and the results generally support our model, with agreeableness, conscientiousness, extraversion, openness, and computer self-efficacy interacting with time and technology type to positively influence team technology use. We also found that the use of the virtual world system positively influenced the relationship between technology use and team cohesion, which, in turn, predicts team performance. The model explains 57 percent, 21 percent, and 24 percent of the variance in team technology use, team cohesion, and team performance, respectively
A Method for Dynamic Characterization and Response Prediction Using Ground Vibration Test(GVT)Data for Unknown Structures.
The Objective Of This Proposed Work Is To Develop A Reliable Method For Dynamic Characterization And Prediction Of Dynamic Response Of Structures Of Known/Unknown Configurations, By Processing The Free Vibration Data Generated Experimentally From The Ground Vibration Tests (GVT)Of The Prototype Vehicles. The Methodology Would Make Use Of The Measured Dynamic Data In Terms Of Mode Shapes, Natural Frequencies, Modal Damping, Point Impedances Etc.And Generate Modal (Scaled) Stiffness And Inertia Information That Will Be Used For Prediction Of Response Characteristics Of The Prototype Structure .
With These Objectives, The Present Work Develops The Mathematical Formulation Of The Method, And Demonstrates Its Reliability By Performing The Experiment On A Simple Cantilever Beam To Determine Its Dynamic Characteristics. Results On Scaled Modal Stiffness And Inertia, Generated Through The Method Using Experimental (GVT) Data Show Excellent Agreement With Those Generated By FE And Analytical Models .It Must Be Noted That A Valid Benchmarking Is Performed With The Condition That The Experimental Procedure Is 'Blind' To The Actual Stiffness And Inertia Distributions As Used In FEM Or Analytical Models . Agreement Of The Predicted Response Of The Structure With That From Direct Experiment And Those From The FE And Analytical Models Indicates That This Method Will Be A Promising Tool To Predict The Dynamic And Aeroelastic Characteristics Of Any Prototype Vehicle In The Future.
Once The Reliability Of The Method Is Established,It Can Be Extended To Determine The Dynamic And Aeroelastic Characteristics Of All Aircraft For Which Dynamic Characteristics Are Available From A Ground -; Vibration Test (GVT)
Predicting the Growth of Two-Dimensional Nanostructures
The ability to predict the morphology of crystals formed by chemical
reactions is of fundamental importance for the shape-controlled synthesis of
nanostructures. Based on the atomistic mechanism for crystal growth under
different driving forces, we have developed morphology diagrams to predict
regimes for the growth of two-dimensional crystals. By using controlled
reactions for crystal growth in the absence of surfactants/capping agents, we
demonstrate the validity of this approach for the formation of 2-D structures
of Au, Ag, Pt, Pd and hydroxyapatite.Comment: 31 pages, 10 figure
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