Improved sensitivity RF photonics doppler frequency measurement system

An improved sensitivity Doppler frequency measurement system based on microwave photonics technology was demonstrated practically. The system employs a four-wave mixing effect to achieve broad radio-frequency (RF) frequency measurement. In addition, a lock-in amplification technique was utilized to achieve high-measurement sensitivity. The system is, thus, capable of Doppler frequency estimation of radar echoes with a carrier frequency up to 40 GHz and a power level as low as $-$35 dBm. © 2009-2012 IEEE

The Effects of Diclofenac on Renal Toxicity Disorders Induced by Gentamicin in Rats

BACKGROUND AND OBJECTIVE: Gentamicin, an antibiotic is used to treat infection with gram-negative bacteria. Due to side effects such as renal disorders, its used is limited. In this research the effect of diclofenac on gentamicin induced nephrotoxicity was examined. METHODS: Male Wistar rats(n=32) weighting between 200-250 g were randomly divided into 4 groups (n = 8 in each group):1- control group received no drug, 2- treatment group with gentamicin (100 mg/kg/day i.p) for 8 days, 3- treatment group with diclofenac (0.5 mg/kg/day i.p) for 8 days, 4- treatment group with gentamicin (100 mg/kg/day i.p) and diclofenac (0.5 mg/kg/day i.p) for 8 days. In ninth day, blood pressure and renal artery blood flow and also level of urea, creatinine, magnesium, sodium, potassium, and osmolality were measured in urine and plasma samples. Finally, histological study was performed by using Hematoxylin and Eosin staining. FINDINGS: Co-treatment with diclofenac significantly decreased fractional excretion of potassium (328±17.6; P<0.001) ، fractional excretion of sodium (0.885±0.005; P<0.001), excretion of urea (56.08±5.56; P<0.001), urine osmolality (439±14.3; p<0.01) and creatinine clearance (p <0.001, 0.427 ± 0.01 ml/min/kg) but decreased renal blood flow (3.99±0.2), which had previously been reduced by gentamicin. CONCLUSION: The results of the study showed that diclofenac exacerbates kidney disorders caused by gentamici

Fixation time in evolutionary graphs: A mean-field approach

Using an analytical method we calculate average conditional fixation time of mutants in a general graph-structured population of two types of species. The method is based on Markov chains and uses a mean-field approximation to calculate the corresponding transition matrix. Analytical results are compared with the results of simulation of the Moran process on a number of network structures

Classification of Heart Sounds Using Chaogram Transform and Deep Convolutional Neural Network Transfer Learning

Heart sounds convey important information regarding potential heart diseases. Currently, heart sound classification attracts many researchers from the fields of telemedicine, digital signal processing, and machine learning—among others—mainly to identify cardiac pathology as quickly as possible. This article proposes chaogram as a new transform to convert heart sound signals to colour images. In the proposed approach, the output image is, therefore, the projection of the reconstructed phase space representation of the phonocardiogram (PCG) signal on three coordinate planes. This has two major benefits: (1) it makes possible to apply deep convolutional neural networks to heart sounds and (2) it is also possible to employ a transfer learning scheme by converting a heart sound signal to an image. The performance of the proposed approach was verified on the PhysioNet dataset. Due to the imbalanced data on this dataset, it is common to assess the results quality using the average of sensitivity and specificity, which is known as score, instead of accuracy. In this study, the best results were achieved using the [Formula: see text] model, which achieved a score of 88.06%

Binaural Acoustic Scene Classification Using Wavelet Scattering, Parallel Ensemble Classifiers and Nonlinear Fusion

The analysis of ambient sounds can be very useful when developing sound base intelligent systems. Acoustic scene classification (ASC) is defined as identifying the area of a recorded sound or clip among some predefined scenes. ASC has huge potential to be used in urban sound event classification systems. This research presents a hybrid method that includes a novel mathematical fusion step which aims to tackle the challenges of ASC accuracy and adaptability of current state-of-the-art models. The proposed method uses a stereo signal, two ensemble classifiers (random subspace), and a novel mathematical fusion step. In the proposed method, a stable, invariant signal representation of the stereo signal is built using Wavelet Scattering Transform (WST). For each mono, i.e., left and right, channel, a different random subspace classifier is trained using WST. A novel mathematical formula for fusion step was developed, its parameters being found using a Genetic algorithm. The results on the DCASE 2017 dataset showed that the proposed method has higher classification accuracy (about 95%), pushing the boundaries of existing methods

Standalone microwave photonics doppler shift estimation system

A standalone microwave photonics system for Doppler frequency measurement purposes is conceived and demonstrated practically. The system exhibits a maximum of 1.61% relative error in Doppler frequency estimation at the worst case. Utilization of all optical mixing has enabled RF frequency independent operation. The system is thus capable of operating at any radar carrier frequency up to 40 GHz. This makes it a perfect candidate for various types of photonic-based radars and frequency agility systems

Resistance of Fritillaria imperialis to freezing stress through gene expression, osmotic adjustment and antioxidants

Plant survival in response to freezing stress depends on the efficient activation of tolerance mechanisms. Fritillaria imperialis exposure to freezing stress enhanced signalling molecules Ca2+ and H2O2 along with overexpression of Ca2+ signalling proteins (Ca2+ dependent protein kinases, CPK), followed by upregulation of NHX1 (Na+/H+ antiporter), LEA (late embryogenesis abundant proteins) and P5CS (1-pyrroline-5-carboxylate synthetase). Overexpression of OsCNGC6 was responsible for high accumulation Ca2+, Na+ and K+. The NHX1 gene product transported Na+ to vacuoles and increased cytosolic K+ content to re-establish ionic homeostasis under stress conditions. The reduced water potential of leaves was due to high accumulation of osmolytes and ions. No changes were observed in relative water content of leaves, which might be correlated with overexpression of the LEA gene, which protects against dehydration. High accumulation of H2O2 under freezing stress was responsible for activation of antioxidant systems involving SOD, phenols, anthocyanins, catalase and ascorbate peroxidase. Photosynthesis, suppressed in freezing-stressed plants, returned to normal levels after termination of freezing stress. Taken together, our findings suggest that Fritillaria efficiently tolerated freezing stress through induction of signalling mechanisms and overexpression of cold stress-responsive genes, and prevention of cold-induced water stress, oxidative stress and photosynthetic damage