Applicability assessment of a real-time PCR assay for the specific detection of bovine,ovine and caprine material in feedstuffs

A TaqMan real-time polymerase chain reaction (PCR) method was developed for specific detection of bovine, ovine and caprine processed animal protein (PAP) in industrial feedstuffs. The method uses species-specific primers and probes targeting short mitochondrial D-loop sequences, and a positive amplification control based on 18S rRNA gene. The applicability of the real-time PCR protocol was assessed through analysis of 126 industrial feed samples that were manufactured to reproduce rendering processes of commercial feeds destined for farmed animals. The assay successfully classified samples as positive or negative according to the ruminant composition, enabling qualitative detection of banned material in feeds at levels as low as 0.1%. Although the method provides quantitative potential, results suggest that the real quantitative capability of the assay is limited by the existing variability in terms of composition and processing treatments of the feeds, which affect the amount and quality of amplifiable DNA.     

Small-angle scattering study of colloidal particles in heavy crude oils

The structural and dispersion characteristics of samples of heavy crude oils and fractions isolated from them have been studied. A method of in situ analysis of the aggregation of asphaltenes directly in crude oils on the basis of small-angle X-ray scattering is proposed. It has been shown that the maximum size of scattering particles in all crude oil samples is limited to the value on the order of 8.0 nm; the average diameter is ∼2.0 nm. It has been found that the fraction with sizes of 0.8–2.5 nm is mostly composed of resins. Asphaltenes in crude oils form larger aggregated particles with a size up to 8 nm. A comparative study of model dilute solutions of asphaltenes in toluene (0.23 wt %) has shown that the major part of asphaltenes in the liquid (∼94%) is in the form of individual molecules with a size of 0.4–1.2 nm, and only an insignificant remaining part (∼6%) occurs in the form of large aggregates.     

Microstructure of NiCoAlFeCuCr multi-component systems synthesized by mechanical alloying

The present study uses the mechanical alloying method to produce series of binary to senary alloys based on Ni, Co, Al, Fe, Cu, Cr. Milling times are 0, 10, 20 and 30 h and experiments are performed in a high energy ball mill. The results of this investigation show that an FCC solid solution is formed in all the studied systems, but a different phase formation response is presented in each system. A mixture of FCC and BCC solid solutions in quaternary to senary systems, is formed for short milling times. Apparently, the dissolution rate of Fe and Cr into the FCC solid solution, is low. Moreover, it is observed that additions of these elements promote the formation of BCC solid solution, which is stable at temperatures up to ?1273 K. Finally, it is observed that the heat treated products present a mixture of FCC and BCC solid solutions with lattice parameters close to those found in the milled products.     

Regulation of memory accuracy with multiple answers: The plurality option.

We report two experiments that investigated the regulation of memory accuracy with a new regulatory mechanism: the plurality option. This mechanism is closely related to the grain-size option but involves control over the number of alternatives contained in an answer rather than the quantitative boundaries of a single answer. Participants were presented with a slideshow depicting a robbery (Experiment 1) or a murder (Experiment 2), and their memory was tested with five-alternative multiple-choice questions. For each question, participants were asked to generate two answers: a single answer consisting of one alternative and a plural answer consisting of the single answer and two other alternatives. Each answer was rated for confidence (Experiment 1) or for the likelihood of being correct (Experiment 2), and one of the answers was selected for reporting. Results showed that participants used the plurality option to regulate accuracy, selecting single answers when their accuracy and confidence were high, but opting for plural answers when they were low. Although accuracy was higher for selected plural than for selected single answers, the opposite pattern was evident for confidence or likelihood ratings. This dissociation between confidence and accuracy for selected answers was the result of marked overconfidence in single answers coupled with underconfidence in plural answers. We hypothesize that these results can be attributed to overly dichotomous metacognitive beliefs about personal knowledge states that cause subjective confidence to be extreme. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A formulation to model the nonlinear viscoelastic properties of the vascular tissue

Nearly all soft tissues, including the vascular tissue, present a certain degree of viscoelastic material response, which becomes apparent performing multiple relaxation tests over a wide range of strain levels and plotting the resulting stress relaxation curves, nonlinear viscoelasticity of the tissue. Changes in relaxation rate at each strain may occur at multiple strain levels. A constitutive formulation considering the particular features of the vascular tissue, such as anisotropy, together with these nonlinear viscoelastic phenomena is here presented and used to fit stress?Cstretch curves from experimental relaxation tests. This constitutive model was used to fit several data set of in vitro experimental stress relaxation tests performed on ovine and porcine aorta. The good fitting of the experimental data shows the capability of the model to reproduce the viscoelastic response of the vascular tissue.     

Dosage individualization of erythropoietin using a profile-dependent support vector regression

The external administration of recombinant human erythropoietin is the chosen treatment for those patients with secondary anemia due to chronic renal failure in periodic hemodialysis. The objective of this paper is to carry out an individualized prediction of the EPO dosage to be administered to those patients. The high cost of this medication, its side-effects and the phenomenon of potential resistance which some individuals suffer all justify the need for a model which is capable of optimizing dosage individualization. A group of 110 patients and several patient factors were used to develop the models. The support vector regressor (SVR) is benchmarked with the classical multilayer perceptron (MLP) and the Autoregressive Conditional Heteroskedasticity (ARCH) model. We introduce a priori knowledge by relaxing or tightening the epsilon-insensitive region and the penalization parameter depending on the time period of the patients' follow-up. The so-called profile-dependent SVR (PD-SVR) improves results of the standard SVR method and the MLP. We perform sensitivity analysis on the MLP and inspect the distribution of the support vectors in the input and feature spaces in order to gain knowledge about the problem.     

Fabrication,characterization, and analysis of photodetectors metal-porous silicon with different geometry and thickness of the porous silicon layer

Porous silicon photodetectors obtained by electrochemical etching of p-type non-polished crystalline silicon were studied. A metal-porous silicon structure was used to obtain the rectifying behavior. The geometry of the metal layer deposited by thermal evaporation on the porous zone was modified with different masks fabricated using a photolithographic method. The samples obtained under different anodization conditions were characterized by PL. The sample that showed the best intensity in photoluminescence, centered on 675 nm, was selected and five samples obtained under these conditions were prepared to compare the difference in the photoresponse because of the geometry of the evaporated metal layer. The responsivities obtained show us an important difference between the devices and allow us to propose a specific geometrical pattern to obtain a better response in this kind of devices.     

The effects of controlling capture on multimedia traffic for shared Ethernet systems

The IEEE 802.3 Ethernet standard is evolving to support much higher data rates and improved quality of service. Even low cost halfduplex CSMA/CD networks can be improved using an enhanced backwardscompatible collision arbitration algorithm known as the Binary Logarithmic Arbitration Method (BLAM) now being proposed as the IEEE 802.3w draft standard. BLAM is designed to coexist fairly with the existing Binary Exponential Backoff (BEB) algorithm, while eliminating its shortterm unfairness problems. In this paper, we focus on how BLAM improves Ethernet performance for multimedia data transport. Analytical, simulation, and prototype hardware experimental results using synthetic, trace, and actual measured traffic are presented. It is shown that BLAM Ethernets can support significantly greater numbers of video streams than existing BEB Ethernets and if the delivery requirements for the video traffic are not too strict, that BLAM Ethernets can even support video if the network is completely saturated with data traffic.     

Fault Detection in Switched Current Circuits Using Built-in Transient Current Sensors

Switched current (SI) circuits use analogue memory cells as building blocks. In these cells, like in most analogue circuits, there are hard-to-detect faults with conventional test methods. A test approach based on a built-in dynamic current sensor (BIDCS), whose detection method weights the highest frequency components of the dynamic supply current of the circuit under test, makes possible the detection of these faults, taking into account the changes in the slope of the dynamic supply current induced by the fault. A study of the influence of these faults in neighbouring cells helps to minimize the number of BICS needed in SI circuits as is shown in two algorithmic analogue-to-digital converters. Yolanda Lechuga received a degree in Industrial Engineering from the University of Cantabria (Spain) in April 2000. Since then, she has been collaborating with the Microelectronics Engineering Group at the University of Cantabria, in the Electronics Technology, Systems and Automation Engineering Department. Since October 2000 she has been a post-graduate student, to be appointed as lecturer at this university, where she is working in her Ph.D. She is interested in supply current test methods, fault simulation, BIST and design for test of mixed signal integrated circuits. Román Mozuelos received a degree in Physics with electronics from the University of Cantabria, Spain. From 1991 to 1995 he was working on the development of quartz crystal oscillators. Currently, he is a Ph.D. student and an assistant teacher at the University of Cantabria in the Department of Electronics Technology. His interests include mixed-signal design and test, fault simulation, and supply current monitoring. Miguel A. Allende received his graduate degree in 1985 and Ph.D. degree in 1994, both from the University of Cantabria, Santander, Spain. In 1996, he became an Assistant Professor of Electronics Technology at the same Institution, where he is a member of the Microelectronics Engineering Group at the Electronics Technology, Systems and Automation Engineering Department in the Industrial and Telecommunication Engineering School. His research interests include design of VLSI circuits for industrial applications, test and DfT in digital VLSI communication circuits, and power supply current test of mixed, analogue and digital circuits. Mar Martínez received her graduate degree and Ph.D. from the University of Cantabria (Spain) in 1986 and 1990. She has been Assistant Professor of Electronic Technology at the University of Cantabria (Spain) since 1991. At present, she is a member of the Electronics Technology, Systems and Automation Engineering Department in the Industrial and Telecommunication Engineering School. She has participated in several EU and Spanish National Research Projects. Her main research interest is mixed, analogue and digital circuit testing, using techniques based on supply current monitoring. She is also interested in test and design for test in digital VLSI circuits. Salvador Bracho obtained his graduate degree and Ph.D. from the University of Seville (Spain) in 1967 and 1970. He was appointed Professor of Electronic Technology at the University of Cantabria (Spain) in 1973, where, at present, he is a member of the Electronics Technology, Systems and Automation Engineering Department in the Industrial and Telecommunication Engineering School. He has participated, as leader of the Microelectronics Engineering Group at the University of Cantabria, in more than twenty EU and Spanish National Research Projects. His primary research interest is in the area of test and design for test, such as full scan, partial scan or self-test techniques in digital VLSI communication circuits. He is also interested in mixed-signal, analogue and digital test, using methods based on power supply current monitoring. Another research interest is the design of analogue and digital VLSI circuits for industrial applications. Prof. Bracho is a member of the Institute of Electrical and Electronic Engineers.