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Nonparametric Estimation of Trend Function for Stochastic Differential Equations Driven by a Weighted Fractional Brownian Motion
Get PDFIn this paper, we consider the problem of nonparametric estimation of trend function for stochastic differential equations driven by a weighted fractional Brownian motion (weighted-fBm). Under some general conditions, the consistent uniform, the rate of convergence as well as the asymptotic normality of our estimator are established. In addition, a numerical example is provided to illustrate the validity of the considered estimator
Green Synthesis of Silver Nanoparticles with Antimicrobial Properties Using Phyla dulcis Plant Extract
No full textFoodborne illnesses caused by the consumption of food contaminated with foodborne pathogens at infectious doses are becoming a common health issue throughout the world. Metal nanoparticles with potential antimicrobial properties are an area that can be explored to discover novel antimicrobial agents. The traditional synthesis methods of metal nanoparticles involve the use of toxic chemicals and the generation of harmful byproducts. In this study, a greener method to synthesize silver nanoparticles (AgNPs) with potential antimicrobial properties was investigated. The aqueous extract of the medicinal plant Phyla dulcis Trev. (verbenaceae) was used as the reducing and stabilizing agent to synthesize AgNPs using microwave irradiation. The formation of AgNPs was confirmed using ultraviolet-visible spectroscopy by the appearance of characteristic surface plasmon resonance peaks in the 430-440 nm wavelength range. The size and stability of the AgNPs were studied using Zetasizer nano-series for 5 weeks after synthesis. The average particle size remained between 63 and 76 nm during the first 4 weeks and increased to 114 nm in the fifth week showing possible aggregation after the fourth week. The zeta potential remained between -20 and -24 mV throughout the 5 weeks showing relatively good stability. Scanning electron microscopy/energy dispersive X-ray spectroscopy showed the association of phytoconstituents with the AgNPs. X-ray photoelectron spectroscopy analysis confirmed the formation of metallic nanoparticles starting from silver nitrate. Finally, the AgNPs were tested to be effective against Escherichia coli O157:H7 (ATCC 43888), Salmonella Typhimurium (novobiocin and nalidixic acid resistant strain), Listeria monocytogenes (4b; ATCC 19115), and Staphylococcus aureus (ATCC 6538) strains, which are known to be common foodborne pathogens
Identification of Phytotoxic Levels of Copper and Nickel in Commercial Organic Soil Amendments Recycled from Poultry Farms and Municipal Wastes
No full textCommercial-scale recycling of agricultural and municipal wastes into organic soil amendments facilitates safe disposal of waste and reduces environmental contamination. However, phytotoxicity of commercial organic amendments to crops is a major concern to farmers. Consistent with this, commercial chicken manure and Milorganite (recycled from municipal waste) were found to be phytotoxic. Chicken manure aqueous extract contains 10.8 ppm Cu and 0.7 ppm Ni. The level of Cu and Ni in Milorganite is lower. The current study identified an aqueous solution containing 5 ppm Cu, lower than in chicken manure aqueous extract, was highly phytotoxic to mustard seeds germination. Therefore, phytotoxicity of chicken manure is in part due to Cu. An aqueous solution containing 1 ppm Ni was not phytotoxic; whereas 0.125 ppm Ni was phytotoxic when 62.5 ppm Na, which is nontoxic, was added to the solution. Therefore, synergistic effects of chemicals in the organic amendments may induce phytotoxicity
Studies on the Conversion Cyclic Aldehyde to Aromatic Amine by Reductive Amination
Get PDFAmines have broadly applied in the pharmaceutical and fine chemical industries, which cause intense research for developing efficient methods to produce primary, secondary and tertiary amines in organic synthesis. N, N-dimethyl tertiary amines are useful as catalysts which are buffers on the analysis of peptides and proteins. This transformation proceeds via an active C-N bond, and the most attractive method to produce amines is the reductive amination of carbonyl compounds. This method involves two steps, the condensation of aldehyde and the subsequent imine hydrogenation in the presence of a hydrogen donor. The synthesis of a catalytic, light-driven process for the reductive amination of native Biomass in the presence of heat is considered.
Use of amide as the nitrogen donor and reductant require high temperature. Materials containing zirconium are used as superionic conductors in oxygen sensors, fuel links, and as catalysts of secondary generation. The catalysts applied in environmental protection, petrochemistry, electrocatalysis, polymerization, etc. Zirconium dioxide is an essential component of the Lambda probe (oxygen sensor) and a significant component of catalysts used in fume purification (three-way catalysts (TWC)) for catalytic fuel combustion, etc. Zirconium dioxide can be applied in the catalysis as a single unit or as a component of compound catalysts. Zirconium dioxide characterized by high chemical resistance is stable at a wide temperature range. It possesses both acidic and basic centers. Its properties enable surface processes as a mechanism of bifunctional acid-base catalysis. The number of acidic and basic centers can be changed using proper preparations in ZrO2 synthesis. All polymorph types of ZrO2 are used in catalysis.
In this study, the researcher developed in the presence of a heterogeneous zirconium-based catalyst in which N, N-dimethylformamide at 180°C was used as the solvent, a low molecular weight amine source and a reductant. Aromatic tertiary amines, 3,4-dimethoxy, N, N-dimethyl benzylamine have been produced from starting materials lignin-derived from grass aromatic aldehydes via the Leuckart reaction using ZrO2 as a catalyst. Approximately 94% yield of the tertiary amines were achieved over a straightforward step for the preparation. The reusability of Zirconium dioxide as a catalyst for the system was studied by using the same zirconium for the conversion of Veratraldehyde to tertiary amine at 600°C for 4h by consecutive addition of Veratraldehyde in six catalytic cycles. The catalyst remains active for the six periods with an 86% yield. All results were fully characterized by 1H and 13C nuclear magnetic resonance spectroscopy and Infrared (IR) spectroscopy
Results for the ground state energy of a finite system of dipoles in a one-dimensional crystal lattice
No full textWe investigate the ground state energy of a finite classical system consisting of an arbitrary number of electric dipoles localized at the sites of a regular one-dimensional crystal lattice. The ground state energy per dipole can be exactly calculated in the thermodynamic limit but an exact analytical expression for the energy valid for an arbitrary finite number of dipoles is not possible. In this work we obtain an approximate analytical expression for the ground state energy that applies to any given finite number of dipoles. The approximate analytical expression that we report reproduces the exact numerically calculated values of the ground state energy with an astonishing accuracy
Effects of transrectal palpation with the fetal membrane slip technique for early pregnancy diagnosis on the proportion and type of associated pregnancy loss in dairy cattle
No full textOBJECTIVE: To assess the effect of transrectal palpation (TRP) performed with the fetal membrane slip (FMS) technique for early pregnancy diagnosis on the proportion and type of associated pregnancy losses (PLs) in dairy cattle. ANIMALS: 580 healthy pregnant cattle. PROCEDURES: Data for artificially inseminated females with 1 or 2 viable embryos detected by transrectal ultrasonography (TRUS) at approximately 30 days of gestation were retrospectively assessed. Cattle were assigned to 1 of 2 groups on the basis of whether they did or did not undergo TRP once between 34 and 41 days of gestation (palpation and control group, respectively). At approximately 45 and 60 days of gestation, all cattle were reevaluated by TRUS; PL was categorized as type I (FMS detectable by TRP and TRUS-confirmed evidence of embryo or fetus degeneration and a functional corpus luteum) or type II (FMS undetectable by TRP and no TRUS-confirmed evidence of an embryo or fetus or of a functional corpus luteum). RESULTS: Of the 580 healthy pregnant cattle, 271 underwent TRP and 309 did not. In the palpation and control groups, PL occurred in 40 (14.8%) and 47 (15.2%) cattle, respectively. Among the palpation group\u27s PLs, 17 (43%) were type I and 23 (58%) were type II. Among the control group\u27s PLs, 27 (57%) were type I and 20 (43%) were type II. The prevalance and type of PL did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE: TRP with the FMS technique for early pregnancy diagnosis did not increase the prevalence of PL in dairy cattle or alert the proportion of type I versus type II PL
Green Synthesis of Silver Nanoparticles with Antimicrobial Properties Using Phyla dulcis Plant Extract
No full textFoodborne illnesses caused by the consumption of food contaminated with foodborne pathogens at infectious doses are becoming a common health issue throughout the world. Metal nanoparticles with potential antimicrobial properties are an area that can be explored to discover novel antimicrobial agents. The traditional synthesis methods of metal nanoparticles involve the use of toxic chemicals and the generation of harmful byproducts. In this study, a greener method to synthesize silver nanoparticles (AgNPs) with potential antimicrobial properties was investigated. The aqueous extract of the medicinal plant Phyla dulcis Trev. (verbenaceae) was used as the reducing and stabilizing agent to synthesize AgNPs using microwave irradiation. The formation of AgNPs was confirmed using ultraviolet-visible spectroscopy by the appearance of characteristic surface plasmon resonance peaks in the 430-440 nm wavelength range. The size and stability of the AgNPs were studied using Zetasizer nano-series for 5 weeks after synthesis. The average particle size remained between 63 and 76 nm during the first 4 weeks and increased to 114 nm in the fifth week showing possible aggregation after the fourth week. The zeta potential remained between -20 and -24 mV throughout the 5 weeks showing relatively good stability. Scanning electron microscopy/energy dispersive X-ray spectroscopy showed the association of phytoconstituents with the AgNPs. X-ray photoelectron spectroscopy analysis confirmed the formation of metallic nanoparticles starting from silver nitrate. Finally, the AgNPs were tested to be effective against Escherichia coli O157:H7 (ATCC 43888), Salmonella Typhimurium (novobiocin and nalidixic acid resistant strain), Listeria monocytogenes (4b; ATCC 19115), and Staphylococcus aureus (ATCC 6538) strains, which are known to be common foodborne pathogens
Creating A Patient Handout For Venting Gastrostomy Catheter: A Quality Improvement Project
Get PDFAt the University of Texas MD Anderson Cancer Center (MDACC), approximately 200 patients undergo placement of a venting gastrostomy catheter annually (venting G-catheter). About 10% of these patients are later seen in the emergency room (ER) for complications related to venting G-catheters. These complications include leakage, infection, skin irritation, and dislocation that require interventions ranging from topical management to exchange of the catheter. The purpose of this project was to create an MDACC-designed patient education handout regarding the care of venting G-catheters as a means of improving patient care and reinforcing these concepts for clinical nurses, thus improving their knowledge.
The process for creating the patient education handout included four main steps: synthesis of published evidence-based research findings on the care of venting G-catheters for patients with malignant bowel obstruction; review of the MDACC link for baseline information on the number of patient ER visits; conduct of a pilot study to obtain clinical nurses\u27 expert opinions on the care of venting G-catheters; and validation of the handout\u27s readability using the Flesch-Kincaid Grade Level formula.
Monthly ER visit rates for venting G-catheter-related complications decreased, from 2.85% of patients with venting G-catheters visiting the ER pre-intervention, to 2.07% visiting the ER post-intervention. This change corresponds to a 28% reduction in ER visits following implementation of the intervention. Survey responses also revealed that the nurses\u27 overall knowledge and awareness regarding use of the patient education handout had improved.
These results demonstrate that the patient education handout developed in this project is a useful tool for communicating patient care information regarding venting G-catheters, particularly with respect to discharged patients
Spherically Symmetric Charged Anisotropic Solution In Higher Dimensional Bimetric General Relativity
Get PDFIn this paper we have obtained a solution of field equations of Rosen’s bimetric general relativity (BGR) for the static spherically symmetric space-time with charged anisotropic fluid distribution in (n+2)-dimensions. An exact solution is obtained and a special case is considered. This work is an extension of our previous work where four-dimensional case was discussed
A Study of Small Perturbations in the Coriolis and Centrifugal Forces in RR3BP with Finite Straight Segment
Get PDFIn this paper, the effect of small perturbations in the Coriolis and centrifugal forces on the existence and stability of the equilibrium point in the Robe’s restricted three-body problem (RR3BP) by taking the smaller primary as a finite straight segment is introduced. In the present structure the density rho1 of the fluid filled in the bigger primary of mass m1*and the density rho3 of the infinitesimal body of mass m3 are considered to be equal. It is worth mentioning that the location of the equilibrium point is affected by a small perturbation in the centrifugal force. The present model possesses one equilibrium point L1 which is collinear with the center of mass of the primaries. It lies towards the right or left of the center of the shell according as the perturbation pi2 in the centrifugal force is positive or negative. Further, the stability of L1 is analyzed. The range of stability is affected not only by the perturbations in the Coriolis and centrifugal forces but also by the length of the finite straight segment. For 0 \u3c mu less than or equal to mu*, L1 is unstable whereas for mu* \u3c mu \u3c 1 it becomes stable. It is observed that the Coriolis force is a stabilizing force provided the centrifugal force is kept constant while the centrifugal force is a destabilizing force when the Coriolis force is kept constant