5,050 research outputs found
Evaluation of the role of prolactin to prevent diabetic retinopathy
Abstract:
Introduction: Diabetic retinopathy (DR) is a one of the long-term complications of DM and constitutes the leading cause of blindness in working-age individuals and affects a majority of diabetic patients by 20 years after disease onset.
Objective: The aim of this study it investigation of the potential role of prolactin in the prevention of Diabetic retinopathy.
Methods: The study was conducted on 90 diabetic patients who were divided into a group that included 37 patients without retinopathy and a group that included 27 patients with non-proliferative retinopathy and 26 patients with proliferative retinopathy who attended the Endocrinology clinic and Division at Tishreen University Hospital in Lattakia during the period from 2023 to 2024.
Results: Independent samples T-test analysis showed Significant decreased in prolactin level in diabetic patients with DR in comparison to diabetic patients without DR (p=0.0001). Person correlation showed a statistically significant inverse relationship between prolactin levels and Glycosylated hemoglobin levels between patient groups.
Conclusions: From this study it can be concluded that diabetic patients with retinopathy had lower level of prolactin and serum prolactin does seem to have protective role in diabetic retinopathy
Development of power factor correction using boost converter circuit
This project describes on developed of a system that can control current by using Texas Instruments microcontroller with Code Compressor Studio software. The type of controller used is C2000 Microcontroller (Texas Instrument TMS320F28) for current feedback loop application. The connection between PC as the software for Code Compressor Studio software (CCS), Pulse Width Modulation (PWM), Texas Instrument (interface), gate driver, power factor correction circuit in boost circuit topology and rectifier circuit, load and sensor are the main parts in this project. Texas Instrument works as the interface communication with MATLAB SIMULINK 2015a to the power factor correction system. In order to control the triggering of the MOSFETs in the Power Factor Correction (PFC), the Pulse Width Modulation (PWM) is needed from MATLAB SIMULINK that has been applied in this project. The main objective in this project is to control the current output by using microcontroller and to detect the load current in order to have the closed loop feedback. By designing the rectifier and the boost circuit in MATLAB simulation is the first part of the project, which gives Total Harmonic Distortion in opened loop 23.86 % and meanwhile for about 17.66 % in closed based. At the same time the hardware part has also been assemble. The current controller loop has been designed according to mathematical equations which is achieved the results of efficiency and stability in output voltage and the input current of the source. With 22 V AC voltage input the obtained output of the rectifier circuit voltage is at 21.2 V DC voltage with 0.139 mA current. Meanwhile the boost circuit boosted the output voltage to 31.6 V DC voltage with 1.05 mA amount of current. The project has been accomplished and achieved all the objectives successfully
PENDEKATAN SAINTIFIK PADA PEMBELAJARAN FISIKA DENGAN METODE EKSPERIMEN DAN DEMONSTRASI DITINJAU DARI KEMAMPUAN BERPIKIR ABSTRAK DAN KEMAMPUAN ANALISIS SISWA (Penelitian di SMA Negeri 1 Bayat Klaten Kelas X Tahun Pelajaran 2014/2015 Pada Materi Alat-Alat Optik)
Tujuan dari penelitian ini adalah untuk mengetahui pengaruh pendekatan saintifik menggunakan metode eksperimen dan demonstrasi, kemampuan berpikir abstrak, kemampuan analisis, dan interaksinya terhadap prestasi belajar siswa.
Penelitian ini merupakan eksperimen semu. Populasi dari penelitian ini adalah seluruh siswa kelas X SMA Negeri 1 Bayat Klaten yang terdiri dari 5 kelas. Sampel terdiri dari dua kelas yaitu XA yang pembelajarannya dengan pendekatan saintifik menggunakan metode demonstrasi dan XC menggunakan metode eksperimen. Data prestasi belajar kognitif siswa, kemampuan berpikir abstrak dan kemampuan analisis siswa diperoleh dari hasil tes. Data dinalisis menggunakan anava tiga jalan, dengan desain faktorial 2x2x2.
Kesimpulan dari penelitian ini adalah: (1) ada pengaruh pembelajaran fisika menggunakan metode eksperimen dan demonstrasi terhadap prestasi belajar kognitif siswa (pvalue = 0.001); (2) ada pengaruh kemampuan berpikir abstrak terhadap prestasi belajar kognitif siswa (pvalue = 0.000); (3) ada pengaruh kemampuan analisis terhadap prestasi belajar kognitif siswa (pvalue = 0.047); (4) tidak ada interaksi antara pendekatan saintifik pada pembelajaran fisika dengan kemampuan berpikir abstrak terhadap prestasi belajar kognitif siswa (pvalue = 0.865); (5) tidak ada interaksi antara pendekatan saintifik pada pembelajaran fisika dengan kemampuan analisis terhadap prestasi belajar kognitif siswa (pvalue = 0.865); (6) tidak ada interaksi antara kemampuan berpikir abstrak dengan kemampuan analisis terhadap prestasi belajar kognitif siswa (pvalue = 0.802); (7) tidak ada interaksi antara metode pembelajaran, kemampuan berpikir abstrak, dan kemampuan analisis terhadap prestasi belajar kognitif siswa (pvalue = 0.856)
Colimits in the correspondence bicategory
We interpret several constructions with C*-algebras as colimits in the
bicategory of correspondences. This includes crossed products for actions of
groups and crossed modules, Cuntz-Pimsner algebras of proper product systems,
direct sums and inductive limits, and certain amalgamated free products.Comment: Final versio
Prognosis of Bearing Acoustic Emission Signals Using Supervised Machine Learning
© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Acoustic emission (AE) technique can be successfully utilized for condition monitoring of various machining and industrial processes. To keep machines function at optimal levels, fault prognosis model to predict the remaining useful life (RUL) of machine components is required. This model is used to analyze the output signals of a machine whilst in operation and accordingly helps to set an early alarm tool that reduces the untimely replacement of components and the wasteful machine downtime. Recent improvements indicate the drive on the way towards incorporation of prognosis and diagnosis machine learning techniques in future machine health management systems. With this in mind, this work employs three supervised machine learning techniques; support vector machine regression, multilayer artificial neural network model and gaussian process regression, to correlate AE features with corresponding natural wear of slow speed bearings throughout series of laboratory experiments. Analysis of signal parameters such as signal intensity estimator and root mean square was undertaken to discriminate individual types of early damage. It was concluded that neural networks model with back propagation learning algorithm has an advantage over the other models in estimating the RUL for slow speed bearings if the proper network structure is chosen and sufficient data is provided.Peer reviewe
Blind Two-Dimensional Super-Resolution and Its Performance Guarantee
In this work, we study the problem of identifying the parameters of a linear
system from its response to multiple unknown input waveforms. We assume that
the system response, which is the only given information, is a scaled
superposition of time-delayed and frequency-shifted versions of the unknown
waveforms. Such kind of problem is severely ill-posed and does not yield a
unique solution without introducing further constraints. To fully characterize
the linear system, we assume that the unknown waveforms lie in a common known
low-dimensional subspace that satisfies certain randomness and concentration
properties. Then, we develop a blind two-dimensional (2D) super-resolution
framework that applies to a large number of applications such as radar imaging,
image restoration, and indoor source localization. In this framework, we show
that under a minimum separation condition between the time-frequency shifts,
all the unknowns that characterize the linear system can be recovered precisely
and with very high probability provided that a lower bound on the total number
of the observed samples is satisfied. The proposed framework is based on 2D
atomic norm minimization problem which is shown to be reformulated and solved
efficiently via semidefinite programming. Simulation results that confirm the
theoretical findings of the paper are provided
Determinants of Privatisation in Selected Sub-Saharan African Countries: Is Privatisation Politically Induced?
While African governments and international donors generally support privatisation for stabilisation as an imperative of public finance problems, academicians are more inclined to discuss the efficiency gains of privatisation. Antithetically, some political economists argue that whereas African governments actually de-emphasise privatisation, donors mainly insist on privatisation to promote neoclassical views without offering an alternative to state reform. This paper realises that the main purposes of privatisation in Sub-Saharan Africa have, so far, been multidimensional. It envisages, empirically, the determinants of privatisation in Sub-Saharan Africa using a probit model over the period 1970-1994. The results are supportive of the hypothesis that privatisation in the sample countries is induced by macro-instability and political bias.
Genetic variability, heritability and character association of grain yield and its components among selected genotypes of maize (Zea mays L.), Gezira State, Sudan
In the Sudan, the low yield of maize was mainly due to the use of low yielding land races and open-pollinated varieties. Hence, the current study was conducted to measure the extent of genotypic and phenotypic variability, genotypic performance, heritability, genotype x season interaction, and the magnitude of association among seed yield and its components of 10 maize genotypes. The experiment was carried out during the summer of 2017 and the winter of 2017/18, using a randomized complete block design with three replicates, at the University of Gezira Farm, Wad Medani, Sudan. The characters measured were days to 50% tasseling and silking, plant and ear height, number of kernels per row and per ear, ear diameter, cob length, 100-kernels weight and grain yield. High significant phenotypic variability was detected for all the measured characters. Seasonal differences were also significant. High broad sense heritability estimates were recorded for 50% tasseling and silking and plant height while the rest of the characters showed moderate estimates. The study confirmed the fact that maize is a summer crop in central Sudan. In summer, the highest seed yield genotype was HSD 5158 (2609 kg/ha) and in winter was HSD 3538 (2285 kg/ha). Days to 50% tasseling and silking and plant height were significantly and positively correlated with yield and so recommended as selection criteria for seed yield improvement. It is recommended to grow genotypes HSD 5158 in summer and HSD 3538 in winter as well as genotypes VMH 4040, VMH 4102 and HSD 5007 in both seasons. Testing of these genotypes under different locations and seasons is suggested.
يعزى ضعف إنتاجية الذرة الشامية بالسودان لزراعة أصناف مفتوحة التلقيح وسلالات محلية ضعيفة الإنتاج. هدفت هذه الدراسة لقياس التباين الظاهري والوراثي ودرجة التوريث على المدى العريض وتفاعل الطراز الوراثي والموسم وارتباط إنتاج البذور ومكوناته. نفذت التجربة في صيف 2017 وشتاء 18/2017 بتصميم القطاعات العشوائية الكاملة بثلاث مكررات بمزرعة جامعة الجزيرة، واد مدني، السودان. الصفات التي قيست هي : عدد الأيام لظهور 50% من الأزهار المذكرة والمؤنثة وطول النبات وارتفاع القندول وعدد بذور الصف والقندول ومحيط القندول وطول الكوز ووزن مائة حبة وإنتاج البذور. أظهرت النتائج اختلافاً معنوياً بين الطرز الوراثية لكل الصفات وفي الموسمين. تأثير الموسم كان معنوياً. سجلت قيم عالية لدرجة التوريث بالمعنى العريض لصفات 50% إزهار مذكر ومؤنث وطول النبات ولكن الصفات الأخرى أظهرت قيم وسطية. ثبت أن محصول الذرة الشامية في وسط السودان محصول صيفي. الطراز الذي أعطى أعلى إنتاجية صيفاً هو HSD 5158 (2609 كجم/هـ) وشتاءً هو HSD 3538 (2285 كجم/هـ). ارتبطت صفات الإزهار المؤنث والمذكر وطول النبات ارتباطاً موجباً ومعنوياً بالإنتاجية وعليه يمكن استعمالها كمؤشرات انتخاب لتحسين إنتاجية الحبوب. يوصى بزراعة الطراز HSD 5158 صيفاً والطراز HSD 3538 شتاءً والطرز VMH 4040 و VMH 4102 و HSD 5007 في الموسمين معاً. يوصى بزراعة هذه الطرز المقترحة في مواسم ومواقع متعددة لتأكيد النتائج.
 
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