Testicular expression of TDRD1, TDRD5, TDRD9 and TDRD12 in azoospermia.

BACKGROUND: Tudor domain-containing proteins (TDRDs) play a critical role in piRNA biogenesis and germ cell development. piRNAs, small regulatory RNAs, act by silencing of transposons during germline development and it has recently been shown in animal model studies that defects in TDRD genes can lead to sterility in males. METHODS: Here we evaluate gene and protein expression levels of four key TDRDs (TDRD1, TDRD5, TDRD9 and TDRD12) in testicular biopsy samples obtained from men with obstructive azoospermia (OA, n = 29), as controls, and various types of non-obstructive azoospermia containing hypospermatogenesis (HP, 28), maturation arrest (MA, n = 30), and Sertoli cell-only syndrome (SCOS, n = 32) as cases. One-way ANOVA test followed by Dunnett's multiple comparison post-test was used to determine inter-group differences in TDRD gene expression among cases and controls. RESULTS: The results showed very low expression of TDRD genes in SCOS specimens. Also, the expression of TDRD1 and TDRD9 genes were lower in MA samples compared to OA samples. The expression of TDRD5 significantly reduced in SCOS, MA and HP specimens than the OA specimens. Indeed, TDRD12 exhibited a very low expression in HP specimens in comparison to OA specimens. All these results were confirmed by Western blot technique. CONCLUSION: TDRDs could be very important in male infertility, which should be express in certain stages of spermatogenesis

Frequency response of IPMC actuators: physical characterization and identification for control

[Abstract] Ionic polymer metal composite (IPMC) actuators have promising applications in robotics and medicine in a not distance future, which will require a big knowledge in different fields, such as, manufacturing, material characterization and control theory. In this paper, frequency response of several IPMC actuators, cut from the same bulk IPMC sheet with a micro laser etching machine, is analyzed. Specifically, the objective is to 1) characterize each actuator, i.e., determine how cutting affects to the parameters of the physical model of this kind of actuators, and 2) identify a model for each actuator for control purposes. The frequency responses have been obtained experimentally in LabVIEW by attaching a couple of gold electrodes to each IPMC unit and measuring the tip deection by means of a laser distance meter.[Resumen] Los actuadores de compuesto de polímero metálico iónico (IPMC) tienen aplicaciones prometedoras en robótica y medicina en un futuro no lejano, lo que requerirá un gran conocimiento en diferentes campos, como la fabricación, la caracterización de materiales y la teoría de control. En este documento, se analiza la respuesta de frecuencia de varios actuadores IPMC, cortados de la misma hoja de IPMC a granel con una máquina de grabado por láser micro. Específicamente, el objetivo es 1) caracterizar cada actuador, es decir, determinar cómo afecta el corte a los parámetros del modelo físico de este tipo de actuadores, y 2) identificar un modelo para cada actuador con fines de control. Las respuestas de frecuencia se han obtenido experimentalmente en LabVIEW al conectar un par de electrodos de oro a cada unidad IPMC y medir la división de la punta por medio de un medidor de distancia láser.Ministerio de Economía y Competitividad; DPI2016-80547-

New food diet formulation for rearing and propagation in white worm (Enchytraeus albidus Henle, 1837)

In this study, 4 different food diets were examined for feeding white worm (Enchytraeus albidus Henle, 1837) which is used as the most important live food for fingerlings sturgeons were studied. Results showed that suitable moisture for growth and development of white worm was 50 - 70 % that their biomass reached to a 675 g/m^2 during 90 days. But it decreased significantly at moisture lower than 45 % and upper than 65 %. White worm had similar growth both in acidic and basic area. White worm biomass reached to 576g/m^2 during 90 days in basic area but reached to 568 g/m^2 in acidic that was maximum at pH 6.4 - 7.6, while its growth decreases at pH lower than 6 and higher than 8. In this study, Azola used as food for white worm in amount of 60%, wheat meal 25%, and wheat bran 15% that caused to more growth in worms and their biomass reached to 533 g/m^2 during 90 days. Although biomass of worm fed with mixture of potato 30%, carrot 3%, wheat meal 25% and wheat bran 15% reached to 584 g/m^2 , but biomass of worms were fed with mixture of potato 60%, wheat meal 25%, and wheat bran 15% reached to 576 during 90 days. Economically, cost production of Azola was lower in comparison to other diets. Biochemical decomposition of worms fed with mixture of Azola, wheat meal and wheat bran showed more protein (33 %) than others. Based on results Azola can be used as a suitable and commercial replacement for white worm food diets

Using an enhanced homotopy perturbation method in fractional differential equations via deforming the linear part

AbstractConvergence and stability are main issues when an asymptotical method like the Homotopy Perturbation Method (HPM) has been used to solve differential equations. In this paper, convergence of the solution of fractional differential equations is maintained. Meanwhile, an effective method is suggested to select the linear part in the HPM to keep the inherent stability of fractional equations. Riccati fractional differential equations as a case study are then solved, using the Enhanced Homotopy Perturbation Method (EHPM). Current results are compared with those derived from the established Adams–Bashforth–Moulton method, in order to verify the accuracy of the EHPM. It is shown that there is excellent agreement between the two sets of results. This finding confirms that the EHPM is powerful and efficient tool for solving nonlinear fractional differential equations

Remnant Magnetisation State Control for Positioning of a Hybrid Tunable Magnet Actuator

The recent development of a hybrid tunable magnet actuator proposes to eliminate Joule heating when maintaining a force or position offset. By controlling the remnant magnetic flux in an AlNiCo magnet within the actuator, the actuation force can be linearly varied and maintained. While a method for tuning the magnetisation state of the magnet with minimal magnetic field changes has been demonstrated previously, the method is inefficient due to its slow tuning rate, which hinders its use in controlling the actuator’s position. This paper presents a novel method of magnetisation state tuning with a fast tuning rate and validates its effectiveness for controlling the position of a short-stroke linear actuator. This tuning method is implemented and verified for changing the flux density of an AlNiCo magnet in the range of ±1.2 T, with a root-mean-square error (RMSE) of 7.2 mT. An accurate estimation of the magnetisation state is furthermore achieved during positioning, guided by the design and experimental validation of a lumped parameter model, allowing the position to be controlled with an RMSE of 4.0 µm in a range of −157 to 320 µm