7,849 research outputs found
Quantum Field Theory of Forward Rates with Stochastic Volatility
In a recent formulation of a quantum field theory of forward rates, the
volatility of the forward rates was taken to be deterministic. The field theory
of the forward rates is generalized to the case of stochastic volatility. Two
cases are analyzed, firstly when volatility is taken to be a function of the
forward rates, and secondly when volatility is taken to be an independent
quantum field. Since volatiltiy is a positive valued quantum field, the full
theory turns out to be an interacting nonlinear quantum field theory in two
dimensions. The state space and Hamiltonian for the interacting theory are
obtained, and shown to have a nontrivial structure due to the manifold moving
with a constant velocity. The no arbitrage condition is reformulated in terms
of the Hamiltonian of the system, and then exactly solved for the nonlinear
interacting case.Comment: 7 Figure
Molecular Typing of Human Brucella melitensis Isolated from Patients in Erbil, Iraq
Brucellosis is a reemerging infectious zoonotic disease of worldwide importance. In the Kurdistan Region of Iraq, it is a widely spread disease and remains a challenging health problem. This disease is mainly caused by Brucella melitensis, in human. For confirmation of these isolates, a study was performed, by isolation and molecular typing of Brucella Spp. from human patients in Rizgari Hospital at Erbil city (Iraq), between March 2014 and November 2016. One hundred sixty seven samples of blood collected from patients suspected for brucellosis, one hundred twenty one samples from these were recorded as genus of Brucella, using biochemical test and confirmed by applying polymerase chain reaction (PCR), using genus specific primer for omp31 gene which was specific for B. melitensis. These results support using molecular method that based on PCR as diagnostic test for the control of brucellosis in Erbil. Further studies are needed from different geographical areas of the country with different level of endemicity to plan and execute control strategies against human brucellosis
Numerical modeling of dynamic powder compaction using the Kawakita equation of state
Dynamic powder compaction is analyzed using the assumption that the powder behaves, while it is being compacted, like a hydrodynamic fluid in which deviatoric stress and heat conduction effects can be ignored throughout the process. This enables techniques of computational fluid dynamics such the equilibrium flux method to be used as a modeling tool. The equation of state of the powder under compression is assumed to be a modified version of the Kawakita loading curve. Computer simulations using this model are performed for conditions matching as closely as possible with those from experiments by Page and Killen [Powder Metall. 30, 233 (1987)]. The numerical and experimental results are compared and a surprising degree of qualitative agreement is observed
Oblique amplitude modulation of dust-acoustic plasma waves
Theoretical and numerical studies are presented of the nonlinear amplitude
modulation of dust-acoustic (DA) waves propagating in an unmagnetized three
component, weakly-coupled, fully ionized plasma consisting of electrons,
positive ions and charged dust particles, considering perturbations oblique to
the carrier wave propagation direction. The stability analysis, based on a
nonlinear Schroedinger-type equation (NLSE), shows that the wave may become
unstable; the stability criteria depend on the angle between the
modulation and propagation directions. Explicit expressions for the instability
rate and threshold have been obtained in terms of the dispersion laws of the
system. The possibility and conditions for the existence of different types of
localized excitations have also been discussed.Comment: 21 pages, 6 figures, to appear in Physica Script
ABO BLOOD GROUPS IN CORRELATION WITH HYPERLIPIDEMIA, DIABETES MELLITUS TYPE II AND ESSENTIAL HYPERTENSION
Objectives: There are associations between ABO blood groups and systemic diseases. So we aim to explore any associations among ABO blood groupwith hyperlipidemia; diabetes mellitus (DM) type II, and essential hypertension.Methods: A total of 800 subjects were recruited. Patients groups were subdivided into hyperlipidemia group (n=100), DM type II group (n=160),and hypertension group (n=166). Fasting blood sample was collected and plasma samples used for measuring of 2, 3-dinor-6-keto-prostaglandinF1α (PGF1α), 11-dehydro-thromboxane (TX) B2, insulin, triglycerides (TGs), total cholesterol (Tc), high-density lipoprotein cholesterol (HDL-C),prothrombin time (PT), activated partial PT (aPPT), blood group type, random blood glucose level, and body mass index (BMI) were also determined.Results: Blood Group A demonstrates a significant elevation in insulin, random blood sugar (RBS), Tc, TGs, and low-density lipoprotein (LDL)/HDLratio and shows a significant decrease in prostacyclin. Blood group B demonstrates a significant elevation in TXB, Tc, TGs, and LDL/HDL ratio andshows a significant decrease in PT. Blood group AB demonstrates a significant elevation in PT, and prostacyclin and shows a significant decrease ininsulin, RBS, Tc, TGs, and LDL/HDL. Blood group O demonstrates a significant elevation in PT, and prostacyclin and shows a significant decrease inTXB2, Tc, TGs, and LDL/HDL ratio.2Conclusions: Blood group AB is protective against hyperlipidemia, diabetes, thrombosis, and hypertension, blood group O is protective againstcardiovascular diseases while blood group B followed by A are risk factors for hypertension and blood group A is a risk factor for diabetes. Thesefindings are establishing the ethnic-dependent correlation of ABO groups and studied diseases.Keywords: Hyperlipidemia, DM type II, Hypertension, Thrombosis, ABO blood groups
Studi Fasies Formasi Endapan Danau untuk Menentukan Lingkungan Pengendapan Danau Limboto
The research area located in the lowland zone and the corrugated hilly zone which is dominated by sedimentary rocks. Therefore, this study aims to determine the geological features of the research area and the study of depositional environmental facies of the Lake Deposits Formation as an analysis of the depositional environment of Limboto Lake. The research method used is the surface geological mapping, measuring a section of stratigraphic and laboratory analysis. Field data consists of stratigraphical features of the research area. Laboratory analysis consists of petrography and stratigraphy-sedimentology analysis. It can be concluded facies and stratigraphy of research from older to youngest, consists of clastic limestones unit formed in Late Miocene-late Early Pliocene age, reef limestones formed in Late Miocene-early Late Pliocene age, sandstones unit formed in Late Pliocene-Pleistocene age, clay unit, and sandy clay unit are deposited in Holocene. Overall the study site consisted of marine, transitional and terrestrial deposition environment with Lake Deposits Formation facies is lake margin clastic deposits and meandering-stream environment deposits
Effective "Penetration Depth" in the Vortex State of a d-wave Superconductor
The temperature and field dependence of the effective magnetic penetration
depth in the vortex state of a d-wave superconductor, as measured by muon spin
rotation experiments, is calculated using a nonlocal London model. We show that
at temperatures below T^* \propto \sqrt{B}, the linear T-dependence of the
effective penetration depth crosses over to a T^3-dependence. This could
provide an explanation for the low temperature flattening of the effective
penetration depth curves observed in a recent muon spin rotation experiment.Comment: 4 pages, RevTex, 3 Postscript figure
A combined approach to data mining of textual and structured data to identify cancer-related targets
BACKGROUND: We present an effective, rapid, systematic data mining approach for identifying genes or proteins related to a particular interest. A selected combination of programs exploring PubMed abstracts, universal gene/protein databases (UniProt, InterPro, NCBI Entrez), and state-of-the-art pathway knowledge bases (LSGraph and Ingenuity Pathway Analysis) was assembled to distinguish enzymes with hydrolytic activities that are expressed in the extracellular space of cancer cells. Proteins were identified with respect to six types of cancer occurring in the prostate, breast, lung, colon, ovary, and pancreas. RESULTS: The data mining method identified previously undetected targets. Our combined strategy applied to each cancer type identified a minimum of 375 proteins expressed within the extracellular space and/or attached to the plasma membrane. The method led to the recognition of human cancer-related hydrolases (on average, ~35 per cancer type), among which were prostatic acid phosphatase, prostate-specific antigen, and sulfatase 1. CONCLUSION: The combined data mining of several databases overcame many of the limitations of querying a single database and enabled the facile identification of gene products. In the case of cancer-related targets, it produced a list of putative extracellular, hydrolytic enzymes that merit additional study as candidates for cancer radioimaging and radiotherapy. The proposed data mining strategy is of a general nature and can be applied to other biological databases for understanding biological functions and diseases
Eliciting Mathematical Thinking of Students Through Realistic Mathematics Eucation
This paper focuses on an implementation a sequence of instructional activities about addition of fractions that has been developed and implemented in grade four of primary school in Surabaya, Indonesia. The theory of Realistic Mathematics Education (RME) has been applied in the sequence, which aims to assist low attaining learners in supporting students' thinking in the addition of fractions. Based on the premise that eliciting and addressing learners' alternative conceptions in mathematics is beneficial in assisting them to improve their understanding, the paper seeks to explore the role that RME plays pertaining to this particular supposition. The paper presents and discusses examples of learners' responses to contextual problems given to them during the course of the instructional activities
Inflaton Fragmentation and Oscillon Formation in Three Dimensions
Analytical arguments suggest that a large class of scalar field potentials
permit the existence of oscillons -- pseudo-stable, non-topological solitons --
in three spatial dimensions. In this paper we numerically explore oscillon
solutions in three dimensions. We confirm the existence of these field
configurations as solutions to the Klein-Gorden equation in an expanding
background, and verify the predictions of Amin and Shirokoff for the
characteristics of individual oscillons for their model. Further, we
demonstrate that significant numbers of oscillons can be generated via
fragmentation of the inflaton condensate, consistent with the analysis of Amin.
These emergent oscillons can easily dominate the post-inflationary universe.
Finally, both analytic and numerical results suggest that oscillons are stable
on timescales longer than the post-inflationary Hubble time. Consequently, the
post-inflationary universe can contain an effective matter-dominated phase,
during which it is dominated by localized concentrations of scalar field
matter.Comment: See http://easther.physics.yale.edu/downloads.html for numerical
codes. Visualizations available at http://www.mit.edu/~mamin/oscillons.html
and http://easther.physics.yale.edu/fields.html V2 Minor fixes to reference
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