974 research outputs found
Supplemental Material - Cyfra 21.1: A Useful Tumour Marker in Pancreatic Ductal Adenocarcinoma: Cross-Sectional Study
No full textSupplemental Material for Cyfra 21.1: A Useful Tumour Marker in Pancreatic Ductal Adenocarcinoma: Cross-Sectional Study by Krishnakumar G. Kuttanchettiyar, Viswanathan Kollengode V, and Meer M. Chisthi in Cancer Control</p
ATMOSPHERIC PHASE DELAY IN SENTINEL SAR INTERFEROMETRY
No full textThe repeat-pass Synthetic Aperture Radio Detection and Ranging (RADAR) Interferometry (InSAR) has been a widely used geodetic technique for observing the Earth’s surface, especially for mapping the Earth’s topography and deformations. However, InSAR measurements are prone to atmospheric errors. RADAR waves traverse the Earth’s atmosphere twice and experience a delay due to atmospheric refraction. The two major layers of the atmosphere (troposphere and ionosphere) are mainly responsible for this delay in the propagating RADAR wave. Previous studies have shown that water vapour and clouds present in the troposphere and the Total Electron Content (TEC) of the ionosphere are responsible for the additional path delay in the RADAR wave. The tropospheric refractivity is mainly dependent on pressure, temperature and partial pressure of water vapour. The tropospheric refractivity leads to an increase in the observed range. These induced propagation delays affect the quality of phase measurement and introduce errors in the topography and deformation fields. The effect of this delay was studied on a differential interferogram (DInSAR). To calculate the amount of tropospheric delay occurred, the meteorological data collected from the Spanish Agencia Estatal de Meteorología (AEMET) and MODIS were used. The interferograms generated from Sentinel-1 carrying C-band Synthetic Aperture RADAR Single Look Complex (SLC) images acquired on the study area are used. The study area consists of different types of scatterers exhibiting different coherence. The existing Saastamoinen model was used to perform a quantitative evaluation of the phase changes caused by pressure, temperature and humidity of the troposphere during the study. Unless the phase values due to atmospheric disturbances are not corrected, it is difficult to obtain accurate measurements. Thus, the atmospheric error correction is essential for all practical applications of DInSAR to avoid inaccurate height and deformation measurements
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No full textWe recently reported that the C2AB portion of Synaptotagmin 1 (Syt1) could selfassemble into Ca2+-sensitive ring-like oligomers on membranes, which could potentially regulate neurotransmitter release. Here we report that analogous ring-like oligomers assemble from the C2AB domains of other Syt isoforms (Syt2, Syt7, Syt9) as well as related C2 domain containing protein, Doc2B and extended Synaptotagmins (E-Syts). Evidently, circular oligomerization is a general and conserved structural aspect of many C2 domain proteins, including Synaptotagmins. Further, using electron microscopy combined with targeted mutations, we show that under physiologically relevant conditions, both the Syt1 ring assembly and its rapid disruption by Ca2+ involve the well-established functional surfaces on the C2B domain that are important for synaptic transmission. Our data suggests that ring formation may be triggered at an early step in synaptic vesicle docking and positions Syt1 to synchronize neurotransmitter release to Ca2+ influx.Fil: Zanetti, Maria Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Bello, Oscar Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Wang, Jing. University of Yale. School of Medicine; Estados UnidosFil: Coleman, Jeff. University of Yale. School of Medicine; Estados UnidosFil: Cai, Yiying. University of Yale. School of Medicine; Estados UnidosFil: Sindelar, Charles V.. University of Yale. School of Medicine; Estados UnidosFil: Rothman, James E.. University of Yale. School of Medicine; Estados UnidosFil: Krishnakumar, Shyam S.. University of Yale. School of Medicine; Estados Unido
Potentialities of Sentinel-1 for mapping and monitoring geological and cryospheric processes in the Patagonia region (Chile)
No full textThis work shows two examples on the use of Sentinel-1 data for monitoring different natural processes, like active geohazards or glacier dynamics in the Patagonia region. Sentinel-1 is a two-satellite constellation, launched by the European Space Agency (ESA), that provides SAR imagery with interferometric capabilities. It is in operation since 2014 and has supposed a significant improvementin the exploitation of these type of data for applications like natural hazards mapping and monitoring. The acquisition policy, that guarantees an acquisition each few days (12 days in Patagonia region) for both ascending and descending trajectories, and the datadistribution policy, that allows free access to the images without legal constrains, are the main reasons for this improvement. These two aspects allowed not only to assure the data in the past but also to perform monitoring plans at medium-long term. In this work we show the potentialities of the use of these data in the Patagonia region through the application of two different techniques in two different application test sites: urban areas and glaciers
Chern-Simons theory of magnetization plateaus on the kagome lattice
No full textFrustrated spin systems on Kagome lattices have long been considered to be a promising candidate for realizing exotic spin liquid phases. Recently, there has been a lot of renewed interest in these systems with the discovery of experimental materials such as Volborthite and Herbertsmithite that have Kagome like structures. In this thesis I will focus on studying frustrated spin systems on the Kagome lattice using a spin-1/2 antiferromagnetic XXZ Heisenberg model in the presence of an external magnetic field as well as other perturbations. Such a system is expected to give rise to magnetization platueaus which can exhibit topological characteristics in certain regimes.
We will first develop a flux-attachment transformation that maps the Heisenberg spins (hard-core bosons) onto a problem of fermions coupled to a Chern-Simons gauge field. This mapping relies on being able to define a consistent Chern-Simons term on the lattice. Using this newly developed mapping we analyse the phases/magnetization plateaus that arise at the mean-field level and also consider the effects of adding fluctuations to various mean-fi eld states. Along the way, we show how to discretize an abelian Chern-Simons gauge theory on generic 2D planar lattices that satisfy certain conditions. We find that as long as there exists a one-to-one correspondence between the vertices and plaquettes defined on the graph, one can write down a discretized lattice version of the abelian Chern-Simons gauge theory.
Using the newly developed flux attachment transformation, we show the existence of chiral spin liquid
states for various magnetization plateaus for certain range of parameters in the XXZ Heisenberg model in the presence of an external magnetic field. Speci cally, in the regime of XY anisotropy the ground states at the 1/3 and 2/3 plateau are equivalent to a bosonic fractional quantum Hall Laughlin state with filling fraction 1/2 and that the 5/9 plateau is equivalent to the first bosonic Jain daughter state at filling fraction 2/3.
Next, we also consider the effects of several perturbations: a) a chirality term, b) a Dzyaloshinskii-Moriya term, and c) a ring-exchange type term on the bowties of the kagome lattice, and inquire if they can also support chiral spin liquids as ground states. We find that the chirality term leads to a chiral spin liquid even in the absence of an uniform magnetic field, with an effective spin Hall conductance of 1/2 in the regime of XY anisotropy. The Dzyaloshinkii-Moriya term also leads a similar chiral spin liquid but only when this term is not too strong. An external magnetic field when combined with some of the above perturbations also has the possibility of giving rise to additional plateaus which also behave like chiral spin liquids in the XY regime. Under the in influence of a ring-exchange term we find that provided its coupling constant is large enough, it may trigger a phase transition into a chiral spin liquid by the spontaneous breaking of time-reversal invariance.
Finally, we also present some numerical results based on some exact diagonalization studies. Here, we specifically focus on the 2/3-magnetization plateau which we previously argued should be a chiral spin liquid with a spin hall conductance of 1/2 . Such a topological state has a non-trivial ground state degeneracy and it excitations are described by semionic quasiparticles. In the numerical analysis, we analyse the ground state degeneracy structure on various Kagome clusters of different sizes. We compute modular matrices from the resultant minimally entangled states as well as the Chern numbers of various eigenstates all of which provide strong evidence that the 2/3-magnetization plateau very closely resembles a chiral spin liquid state with the expected characteristics.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-12-01The student, Ponnuraj Krishnakumar, accepted the attached license on 2016-11-23 at 22:00.The student, Ponnuraj Krishnakumar, submitted this Dissertation for approval on 2016-11-23 at 22:29.This Dissertation was approved for publication on 2016-11-29 at 10:54.DSpace SAF Submission Ingestion Package generated from Vireo submission #10318 on 2017-02-28 at 14:36:45Made available in DSpace on 2017-03-01T16:36:55Z (GMT). No. of bitstreams: 2
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Previous issue date: 2016-11-29Embargo set by: Seth Robbins for item 98599
Lift date: 2019-03-01T16:37:19Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 98599 on 2019-03-02T10:15:27Z
Expression of high mobility group A2 protein inretinoblastoma and its association with clinicopathologic features.
No full textInfluence of carotid tortuosity on the hemodynamics in cerebral aneurysms
No full textClinical observations indicate that the shape and tortuosity of the carotid siphon are some of the contributing factors to the initiation and growth of an aneurysm. The present study explores the validity of this observation by performing systematic numerical simulations. Computational fluid dynamics (CFD) based calculations are performed to compare and contrast four different types of patient-specific carotid siphons, viz., C-, S-, U-, and helical shape, to investigate the hemodynamic influences on flow features, secondary flow patterns, and helicity. Fewer curved regions and the presence of local acute curvature were found to result in higher velocity magnitude, leading to giant sidewall aneurysms in the distal end of this curvature. In contrast, a larger number of curved regions in the parent vessel resulted in disturbed flow and reduced maximum streamwise velocity. When the velocity is lower, smaller aneurysms are observed at the bifurcation carina. The influence of siphon tortuosity, which is exemplified through the Dean number and linked to secondary flows, causes higher helicity when the vessel is more tortuous. It is hypothesized that a highly tortuous vessel protects the further growth of an aneurysm. This is in contrast to a less tortuous vessel with single acute curvature and prone to further expansile behavior of an aneurysm
Consumer Preferences for Imported Kona Coffee in South India: A Latent Class Analysis
No full textConsidering India as a potential export market for 100% Kona coffee, this study explores consumer preferences for imported, specialty, high-end Kona coffee in South India. Conjoint choice experiment with latent class analysis is used and results indicate that India offers an export market potential for Kona coffee, provided it caters to consumer preferences. Results show a significant preference for strong taste. The relative importance of price is lower than taste but majority are also adverse to higher prices. However,15% of the sample population does not care about price but does care about taste, indicating the possibility of a high-end niche market segment. Based on the results, marketing strategies and policy recommendations have been suggested.India, US Coffee Export, Kona Coffee, Conjoint Choice Experiment, Latent Class Analysis, Agribusiness, Q13,
CdO-based nanostructures as novel CO2 gas sensors
No full textCrystalline Cd(OH)2/CdCO3 nanowires, having lengths in the range from 0.3 up to several
microns and 5–30 nm in diameter, were synthesized by a microwave-assisted wet chemical
route and used as a precursor to obtain CdO nanostructures after a suitable thermal treatment in
air. The morphology and microstructure of the as-synthesized and annealed materials have been
investigated by scanning electron microscopy, transmission electron microscopy, x-ray
diffraction and thermogravimetry–differential scanning calorimetry. The change in morphology
and electrical properties with temperature has revealed a wire-to-rod transformation along with
a decreases of electrical resistance.
Annealed samples were printed on a ceramic substrate with interdigitated contacts to
fabricate resistive solid state sensors. Gas sensing properties were explored by monitoring
CO2 in synthetic air in the concentration range 0.2–5 v/v% (2000–50 000 ppm). The effect of
annealing temperature, working temperature and CO2 concentration on sensing properties
(sensitivity, response/recovery time and stability) were investigated. The results obtained
demonstrate that CdO-based thick films have good potential as novel CO2 sensors for practical
applications
Not Available
No full textNot AvailablePhytobeneficial root endophytes of root (wilt) disease resistant coconut palm
Indhuja S1*, Anju R2, Merin Babu1, A.A.Haris1, Krishnakumar, V1
1ICAR-Central Plantation Crops Research Institute, Regional Station, Kayamkulam, Krishnapuram P.O., Alappuzha-690 533, Kerala, India
2Department of Microbiology, St. Mary’s College for women, Paliakkara, Thiruvalla
*Corresponding author
Plant-endophytes interaction and its beneficial role in host fitness and stress mitigation is well established. Endophytes represent a selected fraction of microbial communities of diverse heterotrophs inhabiting the rhizosphere. Endophytic bacteria colonize the roots in high numbers and often exhibit systemic occurrence in the plants without causing negative impact. Plant growth promotion, defense response elicitation and stress modulation are a few functional responsibilities evinced in plant-endophytes interaction. This study is attempted to understand the plant growth promoting functions of culturable bacterial root endophytes of root (wilt) disease (RWD) resistant coconut palm. Fresh feeding roots of apparently healthy (field resistant) coconut selected based on RWD indexing method were sampled for bacterial root endophytes isolation. Plate count showed an average of 2 x 103 cfu/g of fresh root sample on trypticase soya agar. Seventeen bacteria with distinct colony morphotypes were screened for phytobeneficial traits. Of the seventeen, 9 bacteria produced indoleacetic acid ranging from 0.2 to 4.7 µg/mL. Qualitative assessment of nitrogen fixing ability and aminocyclopropane carboxylate (ACC) deaminase activity were made based on their growth on respective media. Six of 17 bacteria grew on nitrogen (N) free media indicating their N fixing potential among which 4 were IAA producers. Seven isolates utilized ACC as their sole N source indicative of their ACC deaminase activity, of which 4 had nitrogen fixation and 3 had IAA production potential. All the 17 bacterial isolates showed growth compatibility with the biocontrol agent Trichoderma harzianum CPTD-28. Three isolates CRE2, CRE9 and CRE15 with all the above plant growth promoting traits were selected for further characterization. All the three bacteria were Gram positive rods with indole negative and catalase positive reactions. Based on 16S rRNA sequence analysis, CRE 2 and CRE 9 were identified belonging to Bacillus subtilis. CRE 15 showed a close similarity with Bacillus Shackletonii. Studies on endophytes of RWD resistant coconut palm in RWD tract are limited and remain a prospective strategy for root (wilt) disease management of coconut.Not Availabl
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