Evidence for the presence of pro-oxytocin/neurophysin-converting enzyme in the human ovary

The activity of pro-oxytocin/neurophysin (pro-OT/Np)-processing enzymes was determined in human granulosa cells, follicular fluids and purified secretory granules of corpora lutea. We detected the presence of an endoprotease which releases OT-Gly10-Lys11-Arg12 on cleavage of the synthetic pro-OT/Np(1-20) peptide after the dibasic Lys11-Arg12 doublet. This endoprotease was inhibited by EDTA, but was not affected by phenylmethanesulfonyl fluoride and pepstatin. Enzymatic activity was markedly reduced by replacement of L-Arg by D-Arg in the basic amino acid doublet of the substrate. The molecular weight of this enzyme was estimated to be 60 kDa. These features closely resembled those of the endoprotease identified in the bovine pituitary. The endoprotease is a metalloenzyme, specific for the Lys-Arg doublet. We also detected a carboxypeptidasic activity, inhibited by guanidinoethane-mercaptosuccinic acid. In the light of our previous detection of the processing intermediates, OT-Gly-Lys-Arg, OT-Gly-Lys and OT-Gly, in human ovary, these observations are in favour of a pro-OT/Np-processing pathway in the human ovary comparable with that in the bovine ovary. Moreover, these results confirm that oxytocin post-translational processing occurs in the human ovary and strongly suggest that pro-OT/Np is synthesized locally.     

Rheological analysis of vapor‐grown carbon nanofiber‐reinforced polyethylene composites

The melt rheological analysis of high‐density polyethylene reinforced with vapor‐grown carbon nanofibers (VGCNFs) was performed on an oscillatory rheometer. The influence of frequency, temperature, and nanofiber concentration (up to 30 wt %) on the rheological properties of composites was investigated. Specifically, the viscosity increase is accompanied by an increase in the elastic melt properties, represented by the storage modulus G′, which is much higher than the increase in the loss modulus G″. The composites and pure PE exhibit a typical shear thinning behavior as complex viscosity decreases rapidly with the increase of shearing frequency. The shear thinning behavior is much more pronounced for the composites with high fiber concentration. The rheological threshold value for this system was found to be around 10 wt % of VGCNF. The damping factor was reduced significantly by the inclusion of nanofibers into the matrix. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 155–162, 2004     

Chattering-Free Sliding Mode Altitude Control for a Quad-Rotor Aircraft: Real-Time Application

Nowadays, the chattering problem in sliding mode control is one of the most important points to consider in real-time applications. To address this problem, a real-time robust altitude control scheme is proposed for the efficient performance of a Quad-rotor aircraft system using a continuous sliding mode control. The sensing of altitude measurement sensing is performed by a pressure sensor in order to obtain a robust altitude control of the vehicle in hovering mode both indoor and outdoor. The altitude measurement has the advantage of introducing this state information directly in the closed loop control which should be very useful for achieving robust stabilization of the altitude control. Accordingly, we propose a sliding mode control strategy without chattering. The sliding mode control proposed removes the chattering phenomenon by replacing a sign function with a high-slope saturation function. The control algorithm is derived from the Lyapunov stability theorem. Moreover, we have assumed that the actuators are able to respond quickly and accurately and we have not enforced limits on the control signals for a real-time application. Finally, to verify the satisfactory performance of proposed nonlinear control law, several simulations and experimental results of the Chattering-free sliding mode control for the Quad-rotor aircraft in the presence of bounded disturbances are presented.     

Fault Estimation for a Quad-Rotor MAV Using a Polynomial Observer

This work addresses the problem of fault detection and diagnosis (FDD) for a quad-rotor mini air vehicle (MAV). Actuator faults are considered on this paper. The basic idea behind the proposed method is to estimate the faults signals using the extended state observers theory. To estimate the faults, a polynomial observer (Aguilar et al. 2011; Mata-Machuca et al., Commun Nonlinear Sci Numer Simul 15(12):4114–4130, 2010, BioSystems 100(1):65–69, 2010) is presented by using the available measurements and know inputs of the system. In order to investigate the diagnosability properties of the system, a differential algebra approach is proposed (Cruz-Victoria et al., J Frankl Inst 345(2):102–118, 2008; and Martinez-Guerra and Diop, IEE P-Contr Theor Ap 151(1):130–135, 2004). The effectiveness of the methodology is illustrated by means of numerical simulations.     

Wind Estimation for Accurate Airplane Path Following Applications

This paper explores the flight of small fixed-wing Unmanned Aerial Vehicle (UAV) in a non-steady environment. The vulnerability of light airplanes to wind is analyzed and the effect of such perturbations on airplane performance is incorporated in the equations of motion. A straightforward wind computation approach, which relies on the difference between the predicted motion of the aircraft and the real motion measured by sensors, is presented in order to be used for a path following application. The analysis takes into account the effect of the noise in sensors measurements and in estimates of orientation and airspeed components. One approach to reducing noise in wind estimates is proposed based on on-line adaptation techniques. Parameter estimation with minimum-order design is obtained using tuning functions. Simulations are carried out representing real flight scenarios in which the wind field is not constant and the sensor measurements are imperfect.     

Fluorine-intercalated carbon fibers-I. structural and transport properties

The intercalation of fluorine in various types of carbon fibers (PAN-based or pitch-based, asreceived or high-temperature treated) has been investigated at room temperature in the presence of gaseous HF. Stage-1 compounds with C_2.5F to C₄F compositions are obtained for 10 bar F₂ pressures, whereas lower pressures (1 bar F₂) lead to stage-2 compounds. Although in higher stages (≥2) the electrical conductivity is generally larger than in the pristine fiber, in stage-1 compounds a drastic increase of resistivity is observed, ρ being more than one order of magnitude larger than that of the starting material. Finally, fluorine-intercalated GICs have been found appropriate to investigate the effects of disorder and reduced dimensionality.     

An International Collaborative Study on Trypsin Inhibitor Assay for Legumes,Cereals, and Related Products

For determining trypsin inhibitor activity (TIA) in soy products, the American Oil Chemists' Society (AOCS) Method Ba 12-75 has been used. It measures differences in absorbance at 410 nm of bovine trypsin activity toward a synthetic substrate (Nα-benzoyl-DL-arginine-p-nitroanilide) in the absence and presence of an inhibitor. Recently, a significantly improved method was developed (JAOCS, 2019, 96:635–645), featuring 5 mL of total assay volume, enzyme-last sequence, and single inhibitor level in duplicate. It is proposed as the AOCS Method Ba 12a-2020. As a part of the AOCS method approval process, a collaborative study involving 12 international laboratories was conducted to evaluate the performance of the proposed method. The study involved measuring TIA in 10 selected test samples plus a blind duplicate. They included soybeans, pulses, cereals, and their processed products (flours, concentrates, and isolates). After rigorous statistical treatment of the data, only three outliers were removed from the data of two samples. Repeatability relative standard deviations (RSDr) for the 11 samples ranged from 0.99% to 5.52%. Reproducibility RSD (RSD_R) ranged from 7.07% to 22.92%, with seven samples having RSD_R around 10% or less. The remaining four samples had very low TIA, and their RSD_R values ranged from 13.34% to 22.92%. The study has demonstrated reliable performance of the proposed AOCS method. Several collaborators carried out additional experiments addressing some aspects of the method, leading to further refinements. The proposed method is undergoing evaluation by the AOCS Uniform Methods Committee for adoption as an Official Method for measuring TIA in various legume and grain products.     

Online Bi-Objective Scheduling for IaaS Clouds Ensuring Quality of Service

This paper focuses on a bi-objective experimental evaluation of online scheduling in the Infrastructure as a Service model of Cloud computing regarding income and power consumption objectives. In this model, customers have the choice between different service levels. Each service level is associated with a price per unit of job execution time, and a slack factor that determines the maximal time span to deliver the requested amount of computing resources. The system, via the scheduling algorithms, is responsible to guarantee the corresponding quality of service for all accepted jobs. Since we do not consider any optimistic scheduling approach, a job cannot be accepted if its service guarantee will not be observed assuming that all accepted jobs receive the requested resources. In this article, we analyze several scheduling algorithms with different cloud configurations and workloads, considering the maximization of the provider income and minimization of the total power consumption of a schedule. We distinguish algorithms depending on the type and amount of information they require: knowledge free, energy-aware, and speed-aware. First, to provide effective guidance in choosing a good strategy, we present a joint analysis of two conflicting goals based on the degradation in performance. The study addresses the behavior of each strategy under each metric. We assess the performance of different scheduling algorithms by determining a set of non-dominated solutions that approximate the Pareto optimal set. We use a set coverage metric to compare the scheduling algorithms in terms of Pareto dominance. We claim that a rather simple scheduling approach can provide the best energy and income trade-offs. This scheduling algorithm performs well in different scenarios with a variety of workloads and cloud configurations.