3,641 research outputs found
A contribution to the knowledge of the species Rafalskia olympica (KULCZYNSKI, 1903) (Opiliones, Phalangiidae, Phalangiinae)
Balkan populations of Rafalskia olympica (KULCZYNSKI, 1903) are distinguished as separate subspecies Rafalskia olympica bulgarica ST ARI::GA, 1963 novo stat. Certain novel details of the R. olympica female body structure are presented. It is stated that Metaplatybunus drenskii SILHAVY, 1965 is not a synonym of R. olympica
A continuous analogue of the tensor-train decomposition
We develop new approximation algorithms and data structures for representing
and computing with multivariate functions using the functional tensor-train
(FT), a continuous extension of the tensor-train (TT) decomposition. The FT
represents functions using a tensor-train ansatz by replacing the
three-dimensional TT cores with univariate matrix-valued functions. The main
contribution of this paper is a framework to compute the FT that employs
adaptive approximations of univariate fibers, and that is not tied to any
tensorized discretization. The algorithm can be coupled with any univariate
linear or nonlinear approximation procedure. We demonstrate that this approach
can generate multivariate function approximations that are several orders of
magnitude more accurate, for the same cost, than those based on the
conventional approach of compressing the coefficient tensor of a tensor-product
basis. Our approach is in the spirit of other continuous computation packages
such as Chebfun, and yields an algorithm which requires the computation of
"continuous" matrix factorizations such as the LU and QR decompositions of
vector-valued functions. To support these developments, we describe continuous
versions of an approximate maximum-volume cross approximation algorithm and of
a rounding algorithm that re-approximates an FT by one of lower ranks. We
demonstrate that our technique improves accuracy and robustness, compared to TT
and quantics-TT approaches with fixed parameterizations, of high-dimensional
integration, differentiation, and approximation of functions with local
features such as discontinuities and other nonlinearities
A rare cause of recurrent spontaneous pneumothorax: Birt-hogg-dube syndrome
Birt-Hogg-Dube (BHD) syndrome is an unusual disorder characterized by the triad of cutaneous lesions, renal tumors and lung cysts. In cases with BHD syndrome, the frequency of recurrent pneumothorax is increased due to presence of multiple lung cysts. It is important to evaluate the BHD syndrome in differential diagnosis of recurrent pneumothorax especially with multiple lung cysts predominating in the lung base. In these patients, the presence of accompanying kidney and other tumors should be investigated. Herein, we report a case of BHD syndrome presenting with recurrent pneumothorax. © 2018 by Turkish Thoracic Society
The SENSE-Isomorphism Theoretical Image Voxel Estimation (SENSE-ITIVE) Model for Reconstruction and Observing Statistical Properties of Reconstruction Operators
The acquisition of sub-sampled data from an array of receiver coils has become a common means of reducing data acquisition time in MRI. Of the various techniques used in parallel MRI, SENSitivity Encoding (SENSE) is one of the most common, making use of a complex-valued weighted least squares estimation to unfold the aliased images. It was recently shown in Bruce et al. [Magn. Reson. Imag. 29(2011):1267-1287] that when the SENSE model is represented in terms of a real-valued isomorphism,it assumes a skew-symmetric covariance between receiver coils, as well as an identity covariance structure between voxels. In this manuscript, we show that not only is the skew-symmetric coil covariance unlike that of real data, but the estimated covariance structure between voxels over a time series of experimental data is not an identity matrix. As such, a new model, entitled SENSE-ITIVE, is described with both revised coil and voxel covariance structures. Both the SENSE and SENSE-ITIVE models are represented in terms of real-valued isomorphisms, allowing for a statistical analysis of reconstructed voxel means, variances, and correlations resulting from the use of different coil and voxel covariance structures used in the reconstruction processes to be conducted. It is shown through both theoretical and experimental illustrations that the miss-specification of the coil and voxel covariance structures in the SENSE model results in a lower standard deviation in each voxel of the reconstructed images, and thus an artificial increase in SNR, compared to the standard deviation and SNR of the SENSE-ITIVE model where both the coil and voxel covariances are appropriately accounted for. It is also shown that there are differences in the correlations induced by the reconstruction operations of both models, and consequently there are differences in the correlations estimated throughout the course of reconstructed time series. These differences in correlations could result in meaningful differences in interpretation of results
IMPACT ASSESSMENT ON MILK INCENTIVE POLICIES IN TURKEY: ANTALYA PROVINCE CASE
Agricultural policy instruments are implementing in different ways among all agricultural based activities. These instruments have been performed for livestock including dairy cattle and milk for many years in Turkey. Until the year 1950, agricultural support system was organized according to genetically improvement, animal illnesses and veterinary services. Nowadays, agricultural support composition has changed. Milk incentive premium is one of the supports given to producers to achieve high quality level for milk. The idea behind this premium was to provide well organized milk distribution channel from producers to modern enterprises. In this study, producers who receive milk incentive premium were chosen for face to face survey in Antalya province. It was examined from the study if premium system is accomplished through the idea. The secondary outcomes of the research were to determine the influence of the premium on producers attitudes, income level, product quantity, as well as membership tendency for cooperatives or unions.milk incentive premium, milk marketing, producer surplus, Antalya, Agricultural and Food Policy, Livestock Production/Industries,
Preliminary Studies on Solid Lipid Microparticles of Loratadine for the Treatment of Allergic Reactions via the Nasal Route
Purpose: To formulate solid lipid microparticles (SLM) of loratadine (LRT) for the treatment of allergic reactions via the nasal route.Methods: Microparticles were prepared by emulsion congealing technique. The drug content of microparticles was analysed. Drug/excipient compatibility and crystallinity characteristics of microparticles were investigated by Fourier Transform Infrared Spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Particle size distribution was determined by laser diffraction (LD). Drug release from microparticles was compared to that from conventional vehicles (O/W emulsion, gel andoleageneous cream) using Franz-type diffusion cells.Results: Drug content of microparticles was > 87.96 %. FT-IR and DSC analysis indicated that the drug and excipients were compatible for at least 6 months at room temperature after production. Microparticle size was between 86 ± 5.63 ìm and 184 ± 13.21 ìm while mean droplet size of O/Wemulsion was 76 ± 3.45 ìm. Release profiles of LRT from microparticles were significantly different from those of O/W emulsion, gel and oleageneous cream (p < 0.05). In the case of conventional vehicles,increase in the hydrophilicity of the vehicles led to increase in drug release rate. Drug release fitted generally to zero order kinetics as well as Korsmeyer-Peppas model for one of the SLM formulations, indicating non-Fickian drug release (super case II transport).Conclusion: SLM provided LRT release for a longer period than the conventional vehicles. However, in vivo studies are required to ascertain the effectiveness of the formulations.Keywords: Loratadine, Solid lipid microparticles, Allergy, Controlled drug delivery, Transnasal deliver
An adaptive speckle suppression filter for medical ultrasound imaging
Cataloged from PDF version of article.An adaptive smoothing technique for speckle suppression in medical B-scan ultrasonic imaging is presented. The technique is based on filtering with appropriately shaped and sized local kernels. For each image pixel, a filtering kernel, which fits to the local homogeneous region containing the processed pixel, is obtained through a local statistics based region growing technique. Performance of the proposed filter has been tested on the phantom and tissue images. The results show that the filter effectively reduces the speckle while preserving the resolvable details. The simulation results are presented in a comparative way with two existing speckle suppression methods. © 1995 IEE
VLSI Circuits for adaptive digital beamforming in ultrasound imaging
Cataloged from PDF version of article.For phased-array ultrasound imaging, alternative
beamforming techniques and their VLSI circuits are studied
to form a fully digital receive frontad hardware. In order
to increase the timiig accuracy in beamforming, a computationally
efficient interpolation scheme to increase the sampling
rate is examined. For adaptive beamforming, a phase aberration
correction method with very low computational complexity is
described. Image quality performance of the method is examined
by processing the non-aberrated and aberrated phased-array
experimental data sets of an ultrasound resolution phantom. A
digital beamforming scheme based on receive focusing at the
raster focal points is examined. The sector images of the resolution
phantom, reconstructed from the phased-array experimental
data by beamforming at the radial and raster focal points, are
presented for comparison of the image resolution performances
of the two beamforming schemes. VLSI circuits and their implementations
for the proposed techniques are presented
On external morphology of the female of Roncus orao Ćurčić, 2004 (Neobisiidae, Pseudoscorpiones) from Montenegro
Direct Measure of Giant Magnetocaloric Entropy Contributions in Ni-Mn-In
Off-stoichiometric alloys based on Ni 2 MnIn have drawn attention due to the
coupled first order magnetic and structural transformations, and the large
magnetocaloric entropy associated with the transformations. Here we describe
calorimetric and magnetic studies of four compositions. The results provide a
direct measure of entropy changes contributions including at the first-order
phase transitions, and thereby a determination of the maximum field-induced
entropy change corresponding to the giant magnetocaloric effect. We find a
large excess entropy change, attributed to magneto-elastic coupling, but only
in compositions with no ferromagnetic order in the high-temperature austenite
phase. Furthermore, a molecular field model corresponding to antiferromagnetism
of the low-temperature phases is in good agreement, and nearly independent of
composition, despite significant differences in overall magnetic response of
these materials
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