616 research outputs found
The upper critical magnetic field of holographic superconductor with conformally invariant power-Maxwell electrodynamics
The properties of -dimensional -wave holographic superconductor in
the presence of power-Maxwell field is explored. We study the probe limit in
which the scalar and gauge fields do not backreact on the background geometry.
Our study is based on the matching of solutions on the boundary and on the
horizon at some intermediate point. At first, the case without external
magnetic field is considered, and the critical temperature is obtained in terms
of the charge density, the dimensionality, and the power-Maxwell exponent.
Then, a magnetic field is turned on in the -dimensional bulk which can
influence the -dimensional holographic superconductor at the boundary.
The phase behavior of the corresponding holographic superconductor is obtained
by computing the upper critical magnetic field in the presence of power-Maxwell
electrodynamics, characterized by the power exponent . Interestingly, it is
observed that in the presence of magnetic field, the physically acceptable
phase behavior of the holographic superconductor is obtained for ,
which guaranties the conformal invariance of the power-Maxwell Lagrangian. The
case of physical interest in five spacetime dimensions (, and ) is
considered in detail, and compared with the results obtained for the usual
Maxwell electrodynamics in the same dimensions.Comment: 12 pages, 1 table, 5 figure
Specific composition and morphological peculiarities of endemic monogenean parasites of freshwater fishes of Iran
Result obtained during ten years research work (1990-2000) on distribution of monogenean fauna Iranian fishes indicates that its composition of monogenean fauna of Iranian fishes depends on their habit and since Iran includes three different zoogeographical zones with highly endemic fish hosts, its monogenean parasites have specific composition. The Caspian fauna is characterized by relatively great diversity of monogenean species (eleven genera and at least forty-eight species). Presence of some species with sphymoid type of anchors is one of its speciation. The Iranian part of Mezopotomian (Tigris) fauna (six genera and at least twenty-six species) is characterized by distinct monogenean parasites, for instance, presence of Dogielius type of anchors and prevalence of Dactylogyrus spp. with morphilogical peculiarities not similar to Sarmatian fauna. The most of its specific character is the shape of dorsal and ventral bar in Dactylogyrus species found in the Tigris Zone. Endemism in the a forsaid zone is high therefore species of Dactylogyrus will be increased more. The oriental monogenean fauna of Iran (three genera and at least eleven species) shows special characteristics, amongthem, the presence of one connective dorsal bar only, presence of varicorhinoid type of bar and haptor would suggest that aforesaid zone of Iran has been influenced by the Indian fauna
A space-time pseudospectral discretization method for solving diffusion optimal control problems with two-sided fractional derivatives
We propose a direct numerical method for the solution of an optimal control
problem governed by a two-side space-fractional diffusion equation. The
presented method contains two main steps. In the first step, the space variable
is discretized by using the Jacobi-Gauss pseudospectral discretization and, in
this way, the original problem is transformed into a classical integer-order
optimal control problem. The main challenge, which we faced in this step, is to
derive the left and right fractional differentiation matrices. In this respect,
novel techniques for derivation of these matrices are presented. In the second
step, the Legendre-Gauss-Radau pseudospectral method is employed. With these
two steps, the original problem is converted into a convex quadratic
optimization problem, which can be solved efficiently by available methods. Our
approach can be easily implemented and extended to cover fractional optimal
control problems with state constraints. Five test examples are provided to
demonstrate the efficiency and validity of the presented method. The results
show that our method reaches the solutions with good accuracy and a low CPU
time.Comment: This is a preprint of a paper whose final and definite form is with
'Journal of Vibration and Control', available from
[http://journals.sagepub.com/home/jvc]. Submitted 02-June-2018; Revised
03-Sept-2018; Accepted 12-Oct-201
Home Bound Working Women and Organizational Efficiency of Developing Economy
This research aims to understand the preferences of educated unemployed womenof Pakistan and India on the imposition of the law of “Flex time/rules for homebound educated women”. For this purpose, 158 respondents were asked to f illa survey out of which 79 respondents were educated employed women and 79respondents were unemployed women (79). Chi-square was applied to the data.Findings suggest that 94% of the women from both the groups are of the viewthat an introduction of women quota would result in an increase in women par-ticipation in the workforce. To understand management’s perspective, 6 inter-views with HR heads of selective industries were conducted. Narrative Analysiswas applied which revealed only 10 to 20% women participated in the totalworkforce. The study also highlights reasons for low women participation. Theseinclude cultural norms, maternal issues, maternity problems, after marriage re-strictions and childbirth. The study concludes that introducing an introductionof women quota in both public and private sectors would help increase womenparticipation and contribution to the country’s economy
Biosynthesis of Silver Nanoparticles from Desmodium triflorum: A Novel Approach Towards Weed Utilization
A single-step environmental friendly approach is employed to synthesize silver nanoparticles. The biomolecules found in plants induce the reduction of Ag+ ions from silver nitrate to silver nanoparticles (AgNPs). UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5–20 nm. X-ray diffraction (XRD) spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. The process of reduction is extracellular and fast which may lead to the development of easy biosynthesis of silver nanoparticles. Plants during glycolysis produce a large amount of H+ ions along with NAD which acts as a strong redoxing agent; this seems to be responsible for the formation of AgNPs. Water-soluble antioxidative agents like ascorbic acids further seem to be responsible for the reduction of AgNPs. These AgNPs produced show good antimicrobial activity against common pathogens
Stress signaling convergence and nutrient crosstalk determine zinc-mediated amelioration against cadmium toxicity in rice
Consumption of rice (Oryza sativa L.) is one of the major pathways for heavy metal bioaccumulation in humans over time. Understanding the molecular responses of rice to heavy metal contamination in agriculture is useful for eco-toxicological assessment of cadmium (Cd) and its interaction with zinc (Zn). In certain crops, the impacts of Cd stress or Zn nutrition on the biophysical chemistry and gene expression have been widely investigated, but their molecular interactions at transcriptomic level, particularly in rice roots, are still elusive. Here, hydroponic investigations were carried out with two rice genotypes (Yinni-801 and Heizhan-43), varying in Cd contents in plant tissues to determine their transcriptomic responses upon Cd15 (15 µM) and Cd15+Zn50 (50 µM) treatments. High throughput RNA-sequencing analysis confirmed that 496 and 2407 DEGs were significantly affected by Cd15 and Cd15+Zn50, respectively, among which 1016 DEGs were commonly induced in both genotypes. Multitude of DEGs fell under the category of protein kinases, such as calmodulin (CaM) and calcineurin B-like protein-interacting protein kinases (CBL), indicating a dynamic shift in hormonal signal transduction and Ca2+ involvement with the onset of treatments. Both genotypes expressed a mutual regulation of transcription factors (TFs) such as WRKY, MYB, NAM, AP2, bHLH and ZFP families under both treatments, whereas genes econding ABC transporters (ABCs), high affinity K+ transporters (HAKs) and Glutathione-S-transferases (GSTs), were highly up-regulated under Cd15+Zn50 in both genotypes. Zinc addition triggered more signaling cascades and detoxification related genes in regulation of immunity along with the suppression of Cd-induced DEGs and restriction of Cd uptake. Conclusively, the effective integration of breeding techniques with candidate genes identified in this study as well as economically and technologically viable methods, such as Zn nutrient management, could pave the way for selecting cultivars with promising agronomic qualities and reduced Cd for sustainable rice production
Direct transcription methods based on fractional integral approximation formulas for solving nonlinear fractional optimal control problems
This paper presents three direct methods based on Grünwald–Letnikov, trapezoidal and Simpson fractional integral formulas to solve fractional optimal control problems (FOCPs). At first, the fractional integral form of FOCP is considered, then the fractional integral is approximated by Grünwald–Letnikov, trapezoidal and Simpson formulas in a matrix approach. Thereafter, the performance index is approximated either by trapezoidal or Simpson quadrature. As a result, FOCPs are reduced to nonlinear programming problems, which can be solved by many well-developed algorithms. To improve the efficiency of the presented method, the gradient of the objective function and the Jacobian of constraints are prepared in closed forms. It is pointed out that the implementation of the methods is simple and, due to the fact that there is no need to derive necessary conditions, the methods can be simply and quickly used to solve a wide class of FOCPs. The efficiency and reliability of the presented methods are assessed by ample numerical tests involving a free final time with path constraint FOCP, a bang-bang FOCP and an optimal control of a fractional-order HIV-immune system.publishe
Case Report: Chemotherapy Indication in a Case of Neurofibromatosis Type 1 Presenting Optic Pathway Glioma: A One-Year Clinical Case Study Using Differential Tractography Approach
Neurofibromatosis type 1 (NF1) is associated with peripheral and central nervous system tumors. It is noteworthy that the regions in which these tumors frequently arise are the optic pathways (OPs) and the brainstem. Thus, we decided to trace the procedure of diffusion Magnetic Resonance Imaging (dMRI) alterations along with Short-Wavelength Automated Perimetry (SWAP) examinations of the OPs after surgery and chemotherapy over 1 year, which enabled us to evaluate chemotherapy's efficacy in an NF1 patient with an OP tumor. In this study, a 25-year-old woman with NF1 and left optic radiation (OR) glioma underwent surgery to remove the glioma. Immunohistochemistry (IHC) revealed a Pilocytic Astrocytoma (PA) WHO grade I. Post-operation chemotherapy done using nine treatment cycles of administering Temozolomide (TMZ) for 5 days every 4 weeks. Applying the region of interest (ROI) differential tractography method and SWAP four times every 3 months allowed us to follow the patient's visual acuity alterations longitudinally. The differential deterministic tractography method and statistical analyses enabled us to discover the white matter (WM) tracts anisotropy alterations over time. Furthermore, statistical analyses on the SWAP results along time illustrated possible alterations in visual acuity. Then, we could compare and associate the findings with the SWAP examinations and patient symptoms longitudinally. Statistical analyses of SWAP tests revealed a significant improvement in visual fields, and longitudinal differential tractography showed myelination and dense axonal packing in the left OR after 1 year of treatment. In this study, we examined an old hypothesis suggesting that chemotherapy is more effective than radiotherapy for NF1 patients with OP gliomas (OPGs) because of the radiation side effects on the visual field, cognition, and cerebrovascular complications. Our longitudinal clinical case study involving dMRI and SWAP on a single NF1-OPG patient showed that chemotherapy did not suppress the OP myelination over time. However, it should be noted that this is a clinical case study, and, therefore, the generalization of results is limited. Future investigations might focus on genetic-based imaging, particularly in more cases. Further, meta-analyses are recommended for giving a proper Field Of View (FOV) to researchers as a subtle clue regarding precision medicine. © Copyright © 2021 Pajavand, Sharifi, Anvari, Bidari-Zerehpoosh, Shamsi, Nateghinia and Meybodi
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