Critical and Gaussian Conductivity Fluctuations in Granular Ho1?xPrxBa2Cu3O7?δ Superconductor

Fluctuations in the electrical conductivity of polycrystalline Ho_1−x Pr _x Ba₂Cu₃O_7−δ superconductors were investigated with Ho contents from x=0.01 up to 0.10. Samples were prepared by the standard solid-state reaction technique. The method of analysis is based on the determination of the quantity c_s^-1=-\fracddTlnDs\chi_{\sigma}^{-1}=-\frac{d}{dT}\ln\Delta\sigma, where Δσ=σ−σ _R is the fluctuation conductivity. The results show that the resistive transition proceeds in two stages as seen by the temperature derivative of the resistivity near T _C . In the normal phase, Gaussian and critical fluctuation conductivity regimes were identified. The pairing transition splitting, associated with Pr doping and related to the occurrence of a phase separation, as observed in studies with other rare earth elements, was not clearly observed. On approaching the zero-resistance state, our results show a power-law behavior that corresponds to a phase transition from a paracoherent to a coherent state of the granular array. This behavior was not affected by Pr doping.     

Microalgal Lipid Extracts Have Potential to Modulate the Inflammatory Response: A Critical Review

Noncommunicable diseases (NCD) and age-associated diseases (AAD) are some of the gravest health concerns worldwide, accounting for up to 70% of total deaths globally. NCD and AAD, such as diabetes, obesity, cardiovascular disease, and cancer, are associated with low-grade chronic inflammation and poor dietary habits. Modulation of the inflammatory status through dietary components is a very appellative approach to fight these diseases and is supported by increasing evidence of natural and dietary components with strong anti-inflammatory activities. The consumption of bioactive lipids has a positive impact on preventing chronic inflammation and consequently NCD and AAD. Thus, new sources of bioactive lipids have been sought out. Microalgae are rich sources of bioactive lipids such as omega-6 and -3 polyunsaturated fatty acids (PUFA) and polar lipids with associated anti-inflammatory activity. PUFAs are enzymatically and non-enzymatically catalyzed to oxylipins and have a significant role in anti and pro-resolving inflammatory responses. Therefore, a large and rapidly growing body of research has been conducted in vivo and in vitro, investigating the potential anti-inflammatory activities of microalgae lipids. This review sought to summarize and critically analyze recent evidence of the anti-inflammatory potential of microalgae lipids and their possible use to prevent or mitigate chronic inflammation.     

A comparative study of STBC transmissions at 2.4 GHz over indoor channels using a 2 × 2 MIMO testbed

In this paper we employ a 2 × 2 Multiple‐Input Multiple‐Output (MIMO) hardware platform to evaluate, in realistic indoor scenarios, the performance of different space‐time block coded (STBC) transmissions at 2.4 GHz. In particular, we focus on the Alamouti orthogonal scheme considering two types of channel state information (CSI) estimation: a conventional pilot‐aided supervised technique and a recently proposed blind method based on second‐order statistics (SOS). For comparison purposes, we also evaluate the performance of a Differential (non‐coherent) space‐time block coding (DSTBC). DSTBC schemes have the advantage of not requiring CSI estimation but they incur in a 3 dB loss in performance. The hardware MIMO platform is based on high‐performance signal acquisition and generation boards, each one equipped with a 1 GB memory module that allows the transmission of extremely large data frames. Upconversion to RF is performed by two RF vector signal generators whereas downconversion is carried out with two custom circuits designed from commercial components. All the baseband signal processing is implemented off‐line in MATLAB ®, making the MIMO testbed very flexible and easily reconfigurable. Using this platform we compare the performance of the described methods in line‐of‐sight (LOS) and non‐line‐of‐sight (NLOS) indoor scenarios. Copyright © 2007 John Wiley & Sons, Ltd.     

Applying the Oscillation Test Strategy to FPAA’s Configurable Analog Blocks

This paper presents the application of the oscillation test methodology as an alternative to test configurable analog blocks of Field Programmable Analog Arrays. The blocks of the device under test are first configured to behave as oscillators. Then, the output frequency and amplitude are observed to obtain the signature of the fault-free circuit. During test, this signature is compared to the actual output signal. Experimental results show the effectiveness of the method in detecting parametric and large deviation faults of the tested components.A paper based on this work was presented at the Fourth IEEE Latin American Test Workshop, Natal, Brazil, February 2003.Tiago Roberto Balen was born in Erechim, Brazil, in 1979. He received the Electrical Engineering degree from the Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil in 2004. At present, he is M.Sc. student in the Electrical Engineering Department and works in the Prototyping and Test Laboratory at UFRGS. His research interests include analog and mixed-signal design and test, built-in self-test and design-for-testability. He has published papers on FPAA testing in important conferences, such as the VLSI Test Symposium (VTS) and the International Test Conference (ITC).Antonio Andrade, Jr., received the Electrical Engineering degree from the Universidade Federal da Bahia (UFBA), Salvador, Brazil, in 2003, and is currently pursuing the M.Sc. degree at Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil. His experience as a researcher includes the design of a temperature controller using thermo-resistive sensors and FPGA prototyping, at the Instrumentation Laboratory in UFBA, in 2001, a 2-month scholarship from Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, Brazil, in 2002, and 2 years as a graduate student at the Prototyping and Test Laboratory, at UFRGS. His primary research topics include Mixed-Signal Circuit and Systems Testing as well as fast system prototyping in platforms as FPGAs and FPAAs, having published papers in important conferences, such as the VLSI Test Symposium (VTS) and International Test Conference (ITC), in the field of FPAA testing.Florence Azaïs received the Ph.D. degree in electrical engineering from the University of Montpellier, France in 1996. She is currently working in the Microelectronics department of the Laboratory of Computer Science, Robotics and Microelectronics of Montpellier (LIRMM) as a researcher of the National Council of Scientific Research (CNRS). Since 1993, she has been interested in the general domain of test and reliability of integrated circuits and systems. Her main research interests include fault modeling, analog and mixed-signal circuit testing, MEMS testing, reliability and failure analysis of integrated systems. She has authored or co-authored over 80 international papers on these topics. She also served as a member of the Program Committee of several international conferences (DATE, ICCD, ETS, IMSTW, LATW).Marcelo Lubaszewski received the Electrical Engineering and M.Sc. degrees from the Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil, in 1986 and 1990, respectively. In 1994, he received the Ph.D. degree from the Institut National Polytechnique de Grenoble (INPG), France. In 2001, he joined the Laboratoire dInformatique, Robotique et Microélectronique de Montpellier in France as an Invited Researcher for 3 months and, in 2004, the Instituto de Microelectrónica de Sevilla (IMSE) in Spain for 1 year. He is currently with UFRGS, where he has been an Associate Professor since 1990. His primary research interests include design and test of mixed-signal, micro-electro-mechanical and core-based systems, self-checking and fault-tolerant architectures, and computer-aided testing. He has published over 150 papers in international journals and conferences on these topics. Dr. Lubaszewski has served as the general chair or program chair of the Symposium on Integrated Circuits and Systems Design (SBCCI) and of the Latin American Test Workshop (LATW), and as a member of the Organizing or the Program Committee of the VLSI Conference, the International Mixed-Signals Testing Workshop, the Asian Test Symposium, the European Design and Test Conference, the Design of Complex Integrated Systems Conference, the European Test Symposium and the GHz/Gbps Test Workshop. He has also served as a Guest Editor of the Journal of Electronic Testing: Theory and Applications and as an Associate Editor of the Design and Test of Computers Magazine.Michel Renovell is head of the Microelectronics Department at LIRMM (Laboratory of Computer Science, Automation and Microelectronics of Montpellier). His research interests include: Fault modeling, Analog testing and FPGA testing. He is Vice-Chair of the IEEE TTTC (Test Technology Technical Committee). He is a member of the editorial board of JETTA and the editorial board of IEEE Design & Test. Michel has been General Chair of the International Mixed Signal Testing Workshop IMSTW2000, the Field Programmable Logic Conference FPL2002 and the European Test Symposium ETS2004.     

Collaborative eScience libraries

In the context of collaborative eScience, digital libraries are one of many distributed, interoperable resources available to scientists that facilitate both human and machine collaboration: machine collaboration in the form of standards such as the Open Archives Initiative Protocol for Metadata Harvesting and human collaboration in the form of collaborative workspaces. This paper describes a set of collaborative workspaces created at the Los Alamos National Laboratory Research Library, initial patterns of use, and additional user requirements determined based on these initial patterns of use.     

嵌入式应用中的能耗调试

优化软件和外设的使用率对于节能是至关重要的在越来越多的嵌入式系统应用中,节能和效率已成为开发人员最优先考虑的因素。这种情况可能是出于以下原因：政府管制、增加电池寿命的需求或者仅仅是需要降低用电量。     

Size limits on doping phosphorus into silicon nanocrystals

We studied the electronic properties of phosphorus-doped silicon nanocrystals using the real-space first-principles pseudopotential method. We simulated nanocrystals with a diameter of up to 6 nm and made a direct comparison with experimental measurement for the first time for these systems. Our calculated size dependence of hyperfine splitting was in excellent agreement with experimental data. We also found a critical nanocrystal size below which we predicted that the dopant will be ejected to the surface.     

Effect of harvesting stress and storage conditions on protein degradation in fillets of farmed gilthead seabream (Sparus aurata): A differential scanning calorimetry study

A trial was undertaken to evaluate Differential Scanning Calorimetry (DSC) as a fast analytical tool to differentiate gilthead seabream subjected to variable conditions of slaughter stress and post-mortem storage. Fish were subjected to different harvesting stress conditions: profound anaesthesia (PA, low stress) and net crowding (NC, high stress). Fish were slaughtered in an ice-salt water slurry, and subsequently stored on ice (7 days). Additional NC fish were frozen (−20 °C) and subjected to a freeze–thaw cycle. Dorsal muscle was assessed for cathepsins activity, liquid loss and DSC analysis. It is demonstrated that DSC analysis is capable of differentiating fresh, frozen and thawed-re-frozen fish, while liquid loss and cathepsin B activity are good markers to distinguish fresh from frozen fish. Harvesting stress had little effect on myosin and actin enthalpy transitions, as observed by DSC at 49 and 74 °C, respectively, but a lower ΔH actin/myosin ratio was found in PA fish, suggesting that intense exercise prior to slaughter promoted partial denaturation of muscle myosin.