Novel Guess Functions for Efficient Analysis of Raman Fiber Amplifiers

Purpose – The aim of the paper is to demonstrate a fast numerical solution for Raman fiber amplifier equations using proposed guess functions and MATLAB intrinsic properties. MATLAB BVP solvers are addressed for the solution. Design/methodology/approach – The guess functions proposed for the solution of RFA equations using MATLAB BVP solvers are derived from Taylor expansion of pump and signal wave near the boundary to specifically obtain convergence for the initial mesh point. The guess functions increase simulation speed significantly. In order to improve the simulation speed further, vectorization and analytical Jacobians are introduced. Comparisons among bvp4c and bvp5c have been made with respect to total pump power, number of signals, vectorization with/without analytical Jacobians, fiber length, relative tolerance and continuation method. The simulations are performed to determine the effect of the run time on the choice of the number of equally spaced mesh points (N) in the initial guess, and thus optimal N values are found. Findings – MATLAB BVP solvers have been proven to be effective for the numerical solution of RFAs with the proposed guess functions. In particular, with vectorizing, run time reduction is between 2.1 and 5.4 times for bvp4c and between 1.6 and 2.1 times for bvp5c and in addition to vectorizing, with the introduction of the analytical Jacobians, the reduction is between 2.4 and 6.2 times for bvp4c and 1.7 and 2.2 times for bvp5c, respectively, depending on the total pump power between 1,000mW and 2,000mW and the number of signals. Also, simulation results show that the efficiency of the solution with proposed guess functions is improved more than six times compared with those of previously reported continuation methods. Results show that the proposed guess functions with the vectorization and analytical Jacobians can be used for the performance evaluation of RFAs for the high power systems/long gain fiber span. Practical implications – The robust improvement of the solution proposed in this paper lies in the fact that the derived guess functions for the RFAs are highly effective in the sense that they assist the solver to converge to the solution for any total pump power value in a wide range from 1 to 3,000mW and for any fiber lengths ranging 1 to 200 km which are used in practical applications. Hence, it is practicable for the performance evaluation of the existing RFA networks. Originality/value – The novelty of this method is that, starting with the co-propagating single pump and signal RFA schema, the authors derived the guess function specifically for the initial mesh points rather than using its analytical approximations. Moreover, the solution is generalized for co-/counter propagating pumps/signals with the curve fitted coefficient(s)

Plasma Apelin Levels and Thiol/Disulfide Balance in Patients with Type 2 Diabetes Mellitus

The main objective of this research is to investigate the relationship between the plasma apelin concentrations, oxidative stress biomarkers (dynamic thiol/disulfide balance), and albuminuria in patients with type 2 diabetes mellitus. Methods: The study was carried out with 87 patients with type 2 diabetes mellitus and 24 age- and sex-matched healthy control group. Serum apelin concentrations were studied using the enzyme-linked immunosorbent assay method. Colorimetric method was used to determine native and total thiol levels. Concentrations of spot urine albumin and creatinine were measured to calculate the albumin creatinine ratio (mg/g). Results: Serum apelin concentrations were significantly lower in patients with type 2 diabetes mellitus compared to the control group (P < .001). Native and total thiol ratios were also significantly lower in diabetic patients compared to healthy patients (P < .001). The calculated disulfide levels of the patients and control groups were similar (P = .182). A negative and significant correlation was detected between serum apelin concentrations, and glucose and hemoglobin A1c levels in diabetic patients (r = −0.272, P = .004, r = −0.280, P = .003, respectively). A negative and significant correlation was also observed between native and total thiol levels and albumin (r = −0.338, P = .001, r = −0.328, P = .001, respectively). Conclusion: We found significantly lowered serum apelin concentrations and native and total thiol levels in patients with type 2 diabetes mellitus. An association was also observed between serum apelin concentrations and glycemic control. The role of apelin and thiol/disulfide balance in diabetic kidney disease requires more detailed studies

The using levels of the teaching methods and techniques by teachers

AbstractThis study aims to determine the teaching strategies, methods and techniques teachers use in Science and Technology classes and what they lack in this issue. 95 teachers, 45 of whom are science teachers and 50 of whom are primary school teachers, were subjected to a survey, and 33 teachers were interviewed orally. It was revealed that the teachers don’t have sufficient knowledge about teaching strategies, methods and techniques and that they can’t distinguish between these concepts. It was seen that the teachers use explanation and question-answer methods more often even though they know that the best technique is the experiment technique and they seldom get their students to carry out experiments. It was concluded that the teachers who don’t exploit various methods despite knowing their advantages need in-service trainings.

Unilateral Nevoid Telangiectasis: Report of Five Cases

Unilateral nevoid telangiectasia (UNT) is a rare cutaneous disorder characterized by superficial telangiectasias distributed unilaterally. UNT can be congenital or acquired. Acquired UNT may be seen during pregnancy, puberty, and in association with cirrhosis and hepatitis C. Besides, the disease has been reported in healthy individuals. In the etiology, elevated blood estrogen levels and/or increased estrogen and progesterone receptors in the involved skin are suggested to cause this disorder. Here, we present four male patients aged 26-33 years, without an identified underlying disease and an 18-year-old female hepatitis B carrier with diagnosis of acquired UNT. Since UNT is seen rarely, it is discussed in the light of the literature data

Diagnosis and management of carotid body tumor: a report of seven cases

Bozok, Sahin/0000-0002-1256-5055WOS: 000314377200038Paragangliomas are rare asymptomatic painless tumors, originating from paraganglionic bodies of autonomous nerve system of the embriological neural crest and increasing gradually. Despite their gradual developing nature, it is critical to reach early diagnosis and tailor surgical plan for carotid body tumors due to their potential of being malignant and local aggressive development, as well as invasion or pressure on the adjacent vascular and neural tissues. in this article, we present seven cases who were admitted with the complaints of pain and swelling in the neck and were diagnosed with carotid body tumor based on the further investigations and were surgically treated in the light of literature review and different surgical modalities were discussed

Investigation on malondialdehyde, s100b and advanced oxidation protein product levels in significant hyperbilirubinemia and the effect of intensive phototherapy on these parameter

Background: The parameters of oxidative stress [advanced oxidation protein products (AOPPs), malondialdehyde (MDA), and S100B] and the effect of intensive phototherapy (PT) on these parameters have not been studied extensively in newborns with significant hyperbilirubinemia (SH). We aimed to measure the levels of MDA, S100B, and AOPPs in newborns with SH, and to compare newborns with healthy control newborns without hyperbilirubinemia on the basis of these parameters of oxidative stress. In addition, we investigated the effect of intensive PT on these parameters during the treatment of SH and report our findings for the first time in the literature. Methods: The study was performed in newborns (n = 62) who underwent intensive PT because of SH. Newborns without jaundice constituted the control group (n = 30). Both groups were compared with respect to demographic characteristics and biochemical (laboratory) parameters including MDA, AOPPs, and S100B. MDA, AOPPs, and S100B were also compared before and after intensive PT in the PT group. In the study group, a correlation analysis of demographic characteristics; MDA, AOPP, and S100B values; and changes occurring in MDA, AOPPs, and S100B values due to the effect of intensive PT was performed. Results: Serum total bilirubin, S100B, and MDA levels in the PT group before performing PT were significantly higher than those in the control group. In newborns receiving PT serum total bilirubin, MDA and AOPP levels decreased significantly after intensive PT. In correlation analysis, a statistically significant negative correlation was found only between the amount of billrubin decrease with PT and AOPP levels after PT in the study group. Conclusion: Whether the significant decrease in MDA levels, which was higher prior to PT, is due to the decrease in serum bilirubin levels or due to the effect of intensive PT itself remains to be determined in further studies. The decrease in AOPP levels after PT implies that intensive PT has protective effects on oxidative stress. Copyright (C) 2014, Taiwan Pediatric Association. Published by Elsevier Taiwan LLC. All rights reserved

Honey Plants of Düzce University Ornamental and Medicinal Plants Botanical Garden

In this study, melliferous plants that the honey bee (Apis mellifera L.) can benefit from among the taxa planted in Düzce University Ornamental and Medicinal Plants Botanical Garden, are presented. Among the 451 taxa planted in the botanical garden, those with these characteristics were determined by reviewing studies on the subject. Of the 165 taxa (36.58%) included in the honey plant class; 119 contain both nectar and pollen, 25 contain pollen, 13 contain nectar, 4 contain both pollen and insect secretion (IS) or sweet sap (SS), 2 contain pollen, nectar and IS or SS, 1 contain both nectar and SS, 1 contain only IS. In order to prevent the decrease in pollinator and pollinator insects, whose numbers are decreasing due to global climate change, a "Bee and Insect Hotel" was placed in the botanical garden. For this reason, the majority of the plants selected for planting were chosen from taxa with honey plant properties. The main purpose here is both to pollinate the plants in the botanical garden and to show and explain the effects of insect species on pollination through nature education