1,938 research outputs found

    Developmental competence of equine oocytes after ICSI : Implications on technical, morphological and cellular aspects

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    Using equine intracytoplasmic sperm injection (ICSI) procedure, the present study was performed, (i) to study the effect of assisted oocyte activation with calcium ionophore A23187 on developmental competence of oocytes, (ii) to re-evaluate the effect of cumulus morphology on meiotic and developmental competence of oocytes, (iii) to investigate the effect of glucose-6-phosphate dehydrogenase (G6PD) activity on meiotic and developmental competence of oocytes and (iv) to analyze zona pellucida (ZP) properties of equine oocytes of different quality and maturational status, quantitatively by polarization light microscopy. One hour after ICSI, injected oocytes were categorized into two groups: those treated with calcium ionophore A23187 and non-treated group. Cleavage and blastocyst rate were significantly (PDie Entwicklungskompetenz equiner Eizellen nach ICSI: technische, morphologische und zellul√§re Aspekte inbegriffen Die vorliegende Studie untersucht den Effekt der assistierten Eizellaktivierung mit Calcium Ionophor A23187 equiner Embryonen nach der intrazytoplasmatischen Spermainjektion (ICSI) auf die Entwicklungskompetenz. Es wurde eine Re-evaluierung des Einflusses der Kumulusmorphologie, der Glucose-6-Phosphat-Dehydrogenase (G6PD) Aktivit√§t und der Beschaffenheit der Zona pellucida mit Hilfe der Polarisationslichtmikroskopie im Hinblick auf die pr√§implantative Entwicklungskompetenz durchgef√ľhrt. Eine Einteilung in zwei Gruppen wurde eine Stunde nach ICSI vorgenommen, wobei nur eine Gruppe mit Calcium- Ionophor A23187 behandelt wurde. Die mit Calcium-Ionophor A23187 behandelten Eizellen zeigten signifikant h√∂here Teilungs- und Blastozystenraten (P < 0,05) als jene, die nicht behandelt wurden. Die Kumulusmorphologie der ungereiften Eizellen (expandierter Kumulus (Ex) vs. kompaktierter Kumulus (Cp)) zeigte ebenfalls signifikante Unterschiede (P<0,05) in der Maturationsrate und der Blastozystenrate nach ICSI. Zur Messung der G6PD Aktivit√§t der Eizellen wurden diese mit Brilliant Cresyl Blue (BCB) gef√§rbt. Der prozentuale Anteil der Eizellen mit einer geringeren G6PD-Aktivit√§t und blauem Cytoplasma war in der Gruppe der Ex Eizellen signifikant h√∂her (P<0,01) als in der Gruppe der Cp Eizellen. Des Weiteren wurden signifikant h√∂here (P<0,05) Maturations- und Entwicklungsraten der BCB+ Eizellen beobachtet verglichen mit Eizellen mit hoher G6PD Aktivit√§t. Mit Hilfe der Polarisationslichtmikroskopie wurde die Zona pellucida der Eizellen mit unterschiedlicher Entwicklungskompetenz (Ex vs. Cp und BCB+ vs. BCB-) und in verschiedenen Reifungsstadien (Immature Eizellen und mature Eizellen mit und ohne Polk√∂rper) vermessen. Unsere Ergebnisse zeigen, dass die Ex Eizellen verglichen mit den Cp Eizellen und die BCB+ Eizellen verglichen mit den BCB- Eizellen eine signifikant (P<0,05) dickere Zona pellucida und eine h√∂here Doppellichtbrechungsintensit√§t aufweisen. Zus√§tzlich hatten die Eizellen, die nach der in vitro Maturation keinen Polk√∂rper ausschleusten, eine signifikant (P<0,05) dickere Zona pellucida und eine signifikant (P<0,05) h√∂here Doppellichtbrechungsintensit√§t als immature Eizellen und Eizellen, die einen Polk√∂rper ausschleusten. Zusammenfassend zeigte sich dass sich die Aktivierung der Eizellen nach ICSI mit Calcium-Ionophor A23187 √§u√üerst positiv auf die Entwicklung der equinen Embryonen auswirkt. Kumulusmorphologie wie auch G6PD Aktivit√§t sind verl√§ssliche Indikatoren f√ľr die Entwicklungskompetenz. Ebenfalls k√∂nnten die Dicke und die Struktur der Zona pellucida, gemessen an Hand der Doppellichtbrechungsintensit√§t, als neue Methode zur Bestimmung des Entwicklungspotentials equiner Eizellen dienen

    A Deep Learning-to-learning Based Control system for renewable microgrids

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    In terms of microgrids (MGs) operation, optimal control and management are vital issues that must be addressed carefully. This paper proposes a practical framework for the optimal energy management and control of renewable MGs considering energy storage (ES) devices, wind turbines, and microturbines. Due to the non-linearity and complexity of operation problems in MGs, it is vital to use an accurate and robust optimization technique to control the power flow of units efficiently. To this end, in the proposed framework, teacher learning-based optimization (TLBO) is utilized to solve the power flow dispatch in the system efficiently. Moreover, a novel hybrid deep learning model based on principal component analysis (PCA), convolutional neural networks (CNN), and bidirectional long short-term memory (BLSTM) is proposed to address the short-term wind power forecasting problem. The feasibility and performance of the proposed framework and the effect of wind power forecasting on operation efficiency are examined using the IEEE 33-bus test system. Also, the Australian Woolnorth wind site data is utilized as a real-world dataset to evaluate the performance of the forecasting model. The results show that the proposed framework can be used to schedule MGs in the best way possible.© 2023 The Authors. IET Renewable Power Generation published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.fi=vertaisarvioitu|en=peerReviewed

    A Framework for Hurricane Resilience Assessment of Power Distribution Systems

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    In current resilience assessment frameworks for power distribution systems, the failure events of overhead structures e.g. utility poles are assumed independent. Since adjacent poles have similarities in wind exposure, age, rate of decay, and structural properties, among others, it is likely that a level of correlation exists between their failure events. To explore potential effects, here correlations among failure events of poles are considered in the simulation process using dichotomized Gaussian method (DGM) that generates correlated failure and survival events. A real distribution network in southeast of U.S. is chosen for the case study. The network consists of three substations with 7051 poles. Following realizations of the physical state of the infrastructure, connectivity based analyses are performed to estimate the number of customers without power considering time-dependent restoration sequences. Results indicate that correlations among failure events of poles have a noticeable impact on the resilience of the power systemneglecting this characteristic results in an error in the estimation of resilience of distribution systems. This may lead to risk management solutions such as maintenance and replacement of utility poles that are not optimal for resilience enhancement purposes

    Effective Management of Energy Internet in Renewable Hybrid Microgrids : A Secured Data Driven Resilient Architecture

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    This paper proposes a two-layer in-depth secured management architecture for the optimal operation of energy internet in hybrid microgrids considering wind turbines, photovoltaics, fuel cell unit, and microturbines. In the physical layer of the proposed architecture, the operation of the grid is formulated as a single objective problem that is solved using teacher learning-based optimization (TLBO). Regarding the cyber layer of the proposed architecture, a two-level intrusion detection system (IDS) is proposed to detect various cyber-attacks (i.e. Sybil attacks, spoofing attacks, false data injection attacks) on wireless-based advanced metering infrastructures. The sequential probability ratio testing (SPRT) approach is utilized in both levels of the proposed IDS to detect cyber-attacks based on a sequence of anomalies rather than only one piece of evidence. The feasibility and performance of the proposed architecture are examined on IEEE 33-bus test system and the results are provided for both islanded and grid-connected operation modes.©2021 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.fi=vertaisarvioitu|en=peerReviewed

    Estudio pedagógico sobre el efecto del mes sagrado de Ramadán en el volumen de operaciones y los rendimientos anormales en el mercado de capitales iraní

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    The objective of this study was to evaluate the calendar effect of the holy month of Ramadan on trading volume and abnormal returns in the Iranian capital market during the years 2009 to 2019 for 10 years in the stock exchange. The present study is considered as applied in terms of purpose and correlation in terms of descriptive method. Also, the data panel model was used to investigate the relationship between the variables. According to the results, the variable coefficient of the effect of the holy month of Ramadan on the trading volume has a significant level of 0.441, therefore, considering that this value is greater than the alpha level of the research, which is equal to 0.05, therefore, this hypothesis (zero) that the variable of the effect of Ramadan is not effective on the variable of trading volume, is not rejected. Therefore, the effect of the calendar of the holy month on the volume of transactions is not significant. Also, variable coefficient of the effect of Ramadan and the share return has a significant level of 0.000, so considering that this value is smaller than the alpha level of the research, which is equal to 0.05, therefore, this hypothesis (zero) that the variable of Ramadan effect D01 does not affect the share return in Iran, is rejected.El objetivo de este estudio fue evaluar el efecto calendario del mes sagrado de Ramad√°n sobre el volumen de operaciones y los rendimientos anormales en el mercado de capitales iran√≠ durante los a√Īos 2009 a 2019 durante 10 a√Īos en la bolsa de valores. El presente estudio se considera aplicado en t√©rminos de prop√≥sito y correlaci√≥n en t√©rminos de m√©todo descriptivo. Adem√°s, se utiliz√≥ el modelo de panel de datos para investigar la relaci√≥n entre las variables. De acuerdo con los resultados, la variable coeficiente del efecto del mes sagrado de Ramad√°n sobre el volumen de negociaci√≥n tiene un nivel significativo de 0.441, por lo tanto, considerando que este valor es mayor que el nivel alfa de la investigaci√≥n, que es igual a 0.05, por lo tanto, no se rechaza esta hip√≥tesis (cero) de que la variable del efecto del Ramad√°n no es efectiva sobre la variable de volumen de comercio. Por tanto, el efecto del calendario del mes sagrado sobre el volumen de transacciones no es significativo. Seg√ļn los resultados la variable coeficiente del efecto del Ramad√°n y el retorno de la acci√≥n tiene un nivel significativo de 0.000, por lo que considerando que este valor es menor que el nivel alfa de la investigaci√≥n, que es igual a 0.05, por lo tanto, esta hip√≥tesis (cero) que la variable de efecto Ramad√°n D01 no afecta la rentabilidad de las acciones en Ir√°n, se rechaza

    Wind Reliability of Transmission Line Models using Kriging-Based Methods

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    Risk assessment of power transmission systems against strong winds requires models that can accurately represent the realistic performance of the physical infrastructure. Capturing material nonlinearity, p-delta effects in towers, buckling of lattice elements, joint slippage, and joint failure requires nonlinear models. For this purpose, this study investigates the reliability of transmission line systems by utilizing a nonlinear model of steel lattice towers, generated in OpenSEES platform. This model is capable of considering various geometric and material nonlinearities mentioned earlier. In order to efficiently estimate the probability of failure of transmission lines, the current study adopts an advanced reliability method through Error rate-based Adaptive Kriging (REAK) proposed by the authors. This method is capable of significantly reducing the number of simulations compared to conventional Monte Carlo methods such that reliability analysis can be done within a reasonable time. Results indicate that REAK efficiently estimates the reliability of transmission lines with a maximum of 150 Finite Element simulations for various wind intensities

    Trans-Ureteral Ureterolithotripsy of Ureteral Calculi:Which is the Best; Pneumatic or Holmium Laser Technique?

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    INTRODUCTION: Our aim was compare of two types of lithotripter include holmium: YAG laser and pneumatic one in transurethral ureterolithotripsy (TUL) for the management of ureteral calculi ‚Č•1 cm.METHODS: 112 patients with ureteral calculi more than 1 cm were selected in randomized order for pneumatic or holmium: YAG laser transurethral ureterolithotripsy (56 patients in each group). Ultrasonography and intravenous urography were performed for all patients before surgery. Complete clearance and success was defined as the absence of any fragments on post operation KUB and ultrasonography images.RESULTS: Success rate was 85.7% in pneumatic group and 100% in holmium: YAG laser group (p =0.003). Stone migration up in the pelvicalyceal system was observed only in 8 cases of pneumatic group. No statically differences were observed in terms of patient‚Äôs age, hospital stay, and complications between two groups.CONCLUSION: According to our experience, for ureteral stone larger than 1 Cm treatment with ureteroscopy and laser lithotripsy is a preferring approach with favorable operation time and hospital admission, and no more significant complication

    Forage Production in Different Intercropping Patterns of Sorghum (Sorghum Bicolor L.) With Hairy Vetch (Vicia Villosa) in Nitrogen Fertilizer Levels

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    In order to evaluate the intercropping of forage sorghum (Sorghum bicolor) andhairy vetch (Vicia villosa) at different nitrogen fertilizer levels and planting patterns, a field experiment was conducted at the Agricultural Research Station, University of Tabriz in 2014. The experimental design was factorial based on randomized complete block design (RCBD) with three replications. The treatments were nitrogen fertilizer levels (0, 30 and 60 kg N.ha-1) and three planting patterns [(planting sorghum on the furrow bank and planting vetch in the both side of furrow bank (P1), planting sorghum in one side of furrow bank and planting vetch in other side (P2) and planting sorghum on the furrow bank and planting vetch on the furrow bank and both side of furrow bank (P3)]. Results indicated that nitrogen fertilizer application increased sorghum forage yield. The highest sorghum forage yield was achieved in first and second planting patterns by application of 60 kg.ha-1 nitrogen fertilizer. Also, the highest forage yield (371.7 kg. ha-1) of vetch produced in the third nitrogen fertilizer level (N60) and third planting pattern (P3). In all intercropping treatments, land equivalent ratios (LER) were well above 1 indicating yield advantages for intercropping. The greater LER of the intercrops was mainly due to a greater resource use and resource complementarities that when the species were grown alone. The highest LER (1.94) and RVT (1.14) were obtained in first planting pattern with no nitrogen application. Also the greatest LERs (1.92) were obtained under interaction of second planting pattern and third nitrogen fertilizer level (N60). In general, it can be stated that for the production of forage, the combination of first and second planting patterns with no nitrogen application is superior on other planting patterns
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