Color Glass Condensate in Brane Models or Don't Ultra High Energy Cosmic Rays Probe 1015eV10^{15}eV Scale ?

In a previous work hep-ph/0203165 we have studied propagation of relativistic particles in the bulk for some of most popular brane models. Constraints have been put on the parameter space of these models by calculating the time delay due to propagation in the bulk of particles created during the interaction of Ultra High Energy Cosmic Rays with protons in the terrestrial atmosphere. The question was however raised that probability of hard processes in which bulk modes can be produced is small and consequently, the tiny flux of UHECRs can not constrain brane models. Here we use Color Glass Condensate (CGC) model to show that effects of extra dimensions are visible not only in hard processes when the incoming particle hits a massive Kaluza-Klein mode but also through the modification of soft/semi-hard parton distribution. At classical level, for an observer in the CM frame of UHECR and atmospheric hadrons, color charge sources are contracted to a thin sheet with a width inversely proportional to the energy of the ultra energetic cosmic ray hadron and consequently they can see an extra dimension with comparable size. Due to QCD interaction a short life swarm of partons is produced in front of the sheet and its partons can penetrate to the extra-dimension bulk. This reduces the effective density of partons on the brane or in a classical view creates a delay in the arrival of the most energetic particles if they are reflected back due to the warping of the bulk. In CGC approximation the density of swarm at different distance from the classical sheet can be related and therefore it is possible (at least formally) to determine the relative fraction of partons in the bulk and on the brane at different scales. Results of this work are also relevant to the test of brane models in hadron colliders like LHC.Comment: 17 pages, 3 figures. Text is modified to highlight the relation between the distribution gluons at high and low rapidity scales. v3: published versio

An enhanced median filter for removing noise from MR images

In this paper, a novel decision based median (DBM) filter for enhancing MR images has been proposed. The method is based on eliminating impulse noise from MR images. A median-based method to remove impulse noise from digital MR images has been developed. Each pixel is leveled from black to white like gray-level. The method is adjusted in order to decide whether the median operation can be applied on a pixel. The main deficiency in conventional median filter approaches is that all pixels are filtered with no concern about healthy pixels. In this research, to suppress this deficiency, noisy pixels are initially detected, and then the filtering operation is applied on them. The proposed decision method (DM) is simple and leads to fast filtering. The results are more accurate than other conventional filters. Moreover, DM adjusts itself based on the conditions of local detections. In other words, DM operation on detecting a pixel as a noise depends on the previous decision. As a considerable advantage, some unnecessary median operations are eliminated and the number of median operations reduces drastically by using DM. Decision method leads to more acceptable results in scenarios with high noise density. Furthermore, the proposed method reduces the probability of detecting noise-free pixels as noisy pixels and vice versa

Teratogenic effects of carbamazepine on embryonic eye development in pregnant mice

Background: Carbamazepine is an antiepileptic drug used widely for the treatment of epileptic seizures and neuropathic pain. Several malformations in humans, mainly neural tube defects, have been reported as a consequence of its use during pregnancy. The association between maternal use of carbamazepine and congenital eye malformations is not very well understood. Objective: The purpose of this study was to examine this association after intraperitoneal injection of carbamazepine during the period of organogenesis in mice. Methods: Balb/c timed-pregnant mice were divided into 4 experimental and control groups. Two experimental groups received daily intraperitoneal injections of 15mg/kg (group I) or 30mg/kg (group II) of carbamazepine on gestational days 6 to 15. Two control groups received normal saline or Tween 20 (polysorbate 20). Dams underwent Cesarean section on gestational day 18 and embryos were harvested. External examination for eye malformations, routine histological processing of malformed fetuses to study eye morphology, and skeletal staining were performed. Results: The mean weight and crown-rump of the fetuses in both experimental groups were significantly reduced compared with those of the control groups. Various malformations were detected such as brachygnathia, calvarial deformity, vertebral deformity, short tail, and brachydactyly. Premature opening of one or both eyes with mild to severe exophthalmos occurred in the 2 experimental groups. Deformed lens, retinal folds with undeveloped layers, and corneal folds with absence of surface epithelium were detected in both experimental groups. Conclusions: This study, to the best of our knowledge, showed for the first time that intraperitoneal administration of carbamazepine at clinically comparable doses during organogenesis can induce several eye malformations in mice. The implication of these results needs to be considered when carbamazepine is administered during human pregnancy. © 2010 Informa UK Ltd

Relationships between soil depth and terrain attributes in a semi arid hilly region in western Iran

Soil depth generally varies in mountainous regions in rather complex ways. Conventional soil survey methods for evaluating the soil depth in mountainous and hilly regions require a lot of time, effort and consequently relatively large budget to perform. This study was conducted to explore the relationships between soil depth and topographic attributes in a hilly region in western Iran. For this, one hundred sampling points were selected using randomly stratified methodology, and considering all geomorphic surfaces including summit, shoulder, backslope, footslope and toeslope; and soil depth was actually measured. Eleven primary and secondary topographic attributes were derived from the digital elevation model (DEM) at the study area. The result of multiple linear regression indicated that slope, wetness index, catchment area and sediment transport index, which were included in the model, could explain about 76 % of total variability in soil depth at the selected site. This proposed approach may be applicable to other hilly regions in the semi-arid areas at a larger scale

On the behaviour of single scale hard small xx processes in QCD near the black disc limit

We argue that at sufficiently small Bjorken $x$ where pQCD amplitude rapidly increases with energy and violates probability conservation the shadowing effects in the single-scale small $x$ hard QCD processes can be described by an effective quantum field theory of interacting quasiparticles. The quasiparticles are the perturbative QCD ladders. We find, within the WKB approximation, that the smallness of the QCD coupling constant ensures the hierarchy among many-quasiparticle interactions evaluated within physical vacuum and in particular, the dominance in the Lagrangian of the triple quasiparticle interaction. It is explained that the effective field theory considered near the perturbative QCD vacuum contains a tachyon relevant for the divergency of the perturbative QCD series at sufficiently small $x$. We solve the equations of motion of the effective field theory within the WKB approximation and find the physical vacuum and the transitions between the false (perturbative) and physical vacua. Classical solutions which dominate transitions between the false and physical vacua are kinks that cannot be decomposed into perturbative series over the powers of $\alpha_s$. These kinks lead to color inflation and the Bose-Einstein condensation of quasiparticles. The account of the quantum fluctuations around the WKB solution reveals the appearance of the "massless" particles-- "phonons". It is explained that "phonons" are relevant for the black disc behaviour of small $x$ processes, leading to a Froissart rise of the cross-section. The condensation of the ladders produces a color network occupying a "macroscopic" longitudinal volume. We discuss briefly the possible detection of new QCD effects.Comment: 24 pages, 1 Figure. References added, and several misprints eliminate

Electrospinning piezoelectric fibers for biocompatible devices

The field of nanotechnology has been gaining great success due to its potential in developing new generations of nanoscale materials with unprecedented properties and enhanced biological responses. This is particularly exciting using nanofibers, as their mechanical and topographic characteristics can approach those found in naturally occurring biological materials. Electrospinning is a key technique to manufacture ultrafine fibers and fiber meshes with multifunctional features, such as piezoelectricity, to be available on a smaller length scale, thus comparable to subcellular scale, which makes their use increasingly appealing for biomedical applications. These include biocompatible fiber-based devices as smart scaffolds, biosensors, energy harvesters, and nanogenerators for the human body. This paper provides a comprehensive review of current studies focused on the fabrication of ultrafine polymeric and ceramic piezoelectric fibers specifically designed for, or with the potential to be translated toward, biomedical applications. It provides an applicative and technical overview of the biocompatible piezoelectric fibers, with actual and potential applications, an understanding of the electrospinning process, and the properties of nanostructured fibrous materials, including the available modeling approaches. Ultimately, this review aims at enabling a future vision on the impact of these nanomaterials as stimuli-responsive devices in the human body

Solid-state synthesis of NASICON (Na3Zr2Si2PO12) using nanoparticle precursors for optimisation of ionic conductivity

In this work, the effect of varying the size of the precursor raw materials SiO2 and ZrO2 in the solid-state synthesis of NASICON in the form Na3Zr2Si2PO12 was studied. Nanoscale and macro-scale precursor materials were selected for comparison purposes, and a range of sintering times were examined (10, 24 and 40 h) at a temperature of 1230 °C. Na3Zr2Si2PO12 pellets produced from nanopowder precursors were found to produce substantially higher ionic conductivities, with improved morphology and higher density than those produced from larger micron-scaled precursors. The nanoparticle precursors were shown to give a maximum ionic conductivity of 1.16 × 10−3 S cm−1 when sintered at 1230 °C for 40 h, in the higher range of published solid-state Na3Zr2Si2PO12 conductivities. The macro-precursors gave lower ionic conductivity of 0.62 × 10−3 S cm−1 under the same processing conditions. Most current authors do not quote or consider the precursor particle size for solid-state synthesis of Na3Zr2Si2PO12. This study shows the importance of precursor powder particle size in the microstructure and performance of Na3Zr2Si2PO12 during solid-state synthesis and offers a route to improved predictability and consistency of the manufacturing process

Evaluation of relationship between smile line and age

Smile line is one of the most important elements of the smile esthetics. In an attractive smile, the maxillary anterior incisal curve is parallel to the lower lip. With the changes in face, lips and teeth muscles, which are caused by aging, this element (Smile line) also changes. Aging causes smile line to move from its parallel position and in complete smile, formulate different shapes relative to the lower lip curve. Therefore through and accurate information about smile elements and anatomy seems to be essential for attractive smile restoration in various ages. A descriptive research on this issue has been done on 300 men and women between 20 to 70 years of age. Each subject was analyzed and evaluated by careful visual judgment. After the completion of information and evaluation of the results, findings based on the clinical observation on students and clients at Azad University-School of Dentistry have shown that, with the passing of age. The smile line gradually changes form parallel from to straight and then reverse form. Other elements of smile such as tooth lower lip position also changes their forms through aging, and different forms such as slightly covered and touching decline while not touching increases. In the position of lip line the high form declines whereas the low form increases. Keywords: Smile design, Esthetic, Smile lin

Ferroelectric and ferromagnetic nanofibers: synthesis, properties and applications

As first time, ferroelectric (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCTZ), biocompatible (Na0.5K0.5)NbO3 (NKN), and ferromagnetic Y3Fe5O12 (YIG) nanofibers were synthesized by sol-gel assisted electrospining technique. Non-woven, bead-free 100 μm long fiber mat was formed from close-packed nanocrystals after calcination in air at 800°C (BCTZ and NKN) and 1100°C (YIG). BCTZ fibers are 200 nm in width whereas NKN and YIG fibers have smaller 50-100 nm diameter. X-ray diffraction and Raman spectroscopy show that BCTZ and NKN crystallized in tetragonal and rhombohedral polar phases in the vicinity of morphotropic phase boundary. Room temperature ferromagnetism in YIG fibers is indicated by a well formed M-H hysteresis loop with about 70% of remnant magnetization to the saturated value reached at 150 Oe. Broad band microwave spectroscopy revealed strong asymmetry of the shape of ferromagnetic resonance lines that conforms to a three orders of magnitude shape aspect ratio of YIG nanofibers