Exact and Asymptotic Conditions on Traveling Wave Solutions of the Navier-Stokes Equations

We derive necessary conditions that traveling wave solutions of the Navier-Stokes equations must satisfy in the pipe, Couette, and channel flow geometries. Some conditions are exact and must hold for any traveling wave solution irrespective of the Reynolds number ($Re$). Other conditions are asymptotic in the limit $Re\to\infty$. The exact conditions are likely to be useful tools in the study of transitional structures. For the pipe flow geometry, we give computations up to $Re=100000$ showing the connection of our asymptotic conditions to critical layers that accompany vortex structures at high $Re$

Diagnostic accuracy in rotator cuff tears: clinical tests vs MRI

Background: Till date there is a lack of consensus regarding validity of clinical tests in identifying the rotator cuff injuries and also the predictive value of noninvasive investigations done to confirm such shoulder pathology.Methods: We included 48 patients with shoulder complaints in our study who underwent blinded clinical examination and MRI of shoulder, whose findings were compared with arthroscopic findings and were statistically analyzed.Results: In the study group mean age was 47 years and 71% were males. When compared with arthroscopy, clinical examination for supraspinatus had better sensitivity (90) but low specificity and negative predictive value (NPV) (37.5). MRI evaluation of supraspinatus had specificity of 85 and NPV of 60. Infraspinatus had almost similar statistical values. MRI was found to have better specificity (89.5) in comparison with clinical examination (52.6) in subscapularis evaluation along with higher positive (67 vs. 30) and negative predictive value (94 vs. 90).Conclusions: Clinical examination is good in identifying lesion or tear of supraspinatus and subscapularis but may also have false positives, where usage of noninvasive MRI will reduce these false positive in comparison with gold standard arthroscopy. Although clinical examination is very useful for diagnosis of rotator cuff injuries, MRI could be used to improve specificity and predictive values in patients who are planned for surgical management of rotator cuff injury

A small angle neutron scattering study of the vortex matter in La{2-x}Sr{x}CuO{4} (x=0.17)

The magnetic phase diagram of slightly overdoped La{2-x}Sr{x}CuO{4} (x=0.17) is characterised by a field-induced hexagonal to square transition of the vortex lattice at low fields (~0.4 Tesla) [R. Gilardi et al., Phys. Rev. Lett. 88, 217003 (2002)]. Here we report on a small angle neutron scattering study of the vortex lattice at higher fields, that reveals no further change of the coordination of the square vortex lattice up to 10.5 Tesla applied perpendicular to the CuO2 planes. Moreover, it is found that the diffraction signal disappears at temperatures well below Tc, due to the melting of the vortex lattice.Comment: 3 pages, 2 figures. Presented at the New3SC-4 meeting, San Diego, Jan. 16-21 2003; to be published in Int. J. Mod. Phys.

LIGAND BASED PHARMACOPHORE MODELING, VIRTUAL SCREENING AND MOLECULAR DOCKING STUDIES TO DESIGN NOVEL PANCREATIC LIPASE INHIBITORS

Objective: To understand the essential structural features required for pancreatic lipase (PL) inhibitory activity and to design novel chemical entities, ligand-based pharmacophore modeling, virtual screening and docking studies were carried out.Methods: The pharmacophore model was generated based on 133 compounds with PL inhibitory activity using PHASE. An external test set and decoy dataset methods were applied to validate the hypothesis and to retrieve potential PL inhibitors. The generated hypothesis model was further subjected to virtual screening and molecular docking studies.Results: A five point pharmacophoric hypothesis model which consists of three hydrogen bond acceptor sites and two hydrophobic sites was developed. The generated pharmacophore gave significant 3D QSAR (three-dimensional Quantitative Structural Activity Relationship) model with r2 of 0.9389 and Q2 value of 0.4016. After database screening, five molecules were found to have better glide scores and binding interactions with the active site amino acid residues.Conclusion: As an outcome of this study, five hit molecules were suggested as potent PL inhibitors as they showed good glide scores as well as binding interactions with required active site amino acids. The five molecules obtained from this study may serve as potential leads for the development of promising anti-obesity agents.Â

Efficient Curriculum based Continual Learning with Informative Subset Selection for Remote Sensing Scene Classification

We tackle the problem of class incremental learning (CIL) in the realm of landcover classification from optical remote sensing (RS) images in this paper. The paradigm of CIL has recently gained much prominence given the fact that data are generally obtained in a sequential manner for real-world phenomenon. However, CIL has not been extensively considered yet in the domain of RS irrespective of the fact that the satellites tend to discover new classes at different geographical locations temporally. With this motivation, we propose a novel CIL framework inspired by the recent success of replay-memory based approaches and tackling two of their shortcomings. In order to reduce the effect of catastrophic forgetting of the old classes when a new stream arrives, we learn a curriculum of the new classes based on their similarity with the old classes. This is found to limit the degree of forgetting substantially. Next while constructing the replay memory, instead of randomly selecting samples from the old streams, we propose a sample selection strategy which ensures the selection of highly confident samples so as to reduce the effects of noise. We observe a sharp improvement in the CIL performance with the proposed components. Experimental results on the benchmark NWPU-RESISC45, PatternNet, and EuroSAT datasets confirm that our method offers improved stability-plasticity trade-off than the literature

Time-gated optical imaging through turbid media using stimulated Raman scattering: studies on image contrast

In this paper, we report the development of experimental set-up for time-gated optical imaging through turbid media using stimulated Raman scattering. Our studies on the contrast of time-gated images show that for a given optical thickness, the image contrast is better for sample with lower scattering coefficient and higher physical thickness, and that the contrast improves with decreasing value of anisotropy parameters of the scatterers. These results are consistent with time-resolved Monte Carlo simulations

AC CONDUCTIVITY STUDY OF POLYANILINE / NiCuFe 2 O 3 COMPOSITES

ABSTRACT The PANI/ NiCuFe 2 O 3 composites have been synthesized by Insitu polymerization of aniline in the presence of NiCuFe 2 O 3 by chemical oxidation method with various compositions viz., 10, 30, and 50 Wt. % of NiCuFe 2 O 3 in PANI. The AC conductivity was studied in the frequency range 10 2 -10 7 Hz. The dimensions of NiCuFe 2 O 3 particles in the matrix have a greater influence on the conductivity values

Flexure compensation simulation tool for TMT-WFOS Spectrograph

The Wide Field Optical Spectrograph (WFOS) is one of the first-light instruments of Thirty Meter Telescope. It is a medium resolution, multi object, wide field optical spectrograph. Since 2005 the conceptual design of the instrument has focused on a slit-mask based, grating exchange design that will be mounted at the Nasmyth focus of TMT. Based on the experience with ESI, MOSFIRE and DEIMOS for Keck we know flexure related image motion will be a major problem with such a spectrograph and a compensation system is required to mitigate these effects. We have developed a flexure Compensation and Simulation (FCS) tool for TMT-WFOS that provides an interface to accurately simulate the effects of instrument flexure at the WFOS detector plane (e.g image shifts) using perturbation of key optical elements and also derive corrective motions to compensate the image shifts caused by instrument flexure. We are currently using the tool to do mote-carlo simulations to validate the optical design of a slit-mask concept we call Xchange-WFOS, and to optimize the flexure compensation strategy. We intend to use the tool later in the design process to predict the actual flexure by replacing the randomized inputs with the signed displacement and rotations of each element predicted by global FEA model on the instrument

Non-invasive ophthalmic imaging of adult zebrafish eye using optical coherence tomography

We describe the development of a single-mode fibre based optical coherence tomography set-up and its use for non-invasive optical imaging of adult zebrafish (Danio rerio) eyes. The free-space axial and lateral resolutions of the set-up were estimated to be ~ 11 and 17 μm respectively. Images of whole eye, cornea and retina acquired with the set-up have been used to estimate several ocular parameters, viz. corneal thickness, mean retinal thickness and effective refractive index of the crystalline lens