Mixed-Signal Circuit Classification in a Pseudo-Random Testing Scheme

Pseudo-random testing techniques for mixed-signal circuits offer several advantages compared to explicit time-domain and frequency-domain test methods, especially in a BIST structure. To fully exploit these advantages a suitable choice of the pseudo-random input parameters should be done and an investigation on the accuracy of the circuit response samples needed to reduce the risk of misclassification should be carried out. Here these issues have been addressed for a testing scheme based on the estimation of the impulse response of the device under test (DUT) by means of input-output cross-correlation. Moreover, new acceptance criteria for the DUT are suggested which solve some ambiguity problems arising if the classification of the DUT as good or bad is based on a few samples of the cross-correlation function. Examples of application of the proposed techniques to real cases are also shown in order to assess the impact of the measurement system inaccuracies on the reliability of the test.     

Polarization mode dispersion characterization of single-modeoptical fiber using backscattering technique

This paper presents a completely new method able to characterize polarization mode dispersion (PMD) properties of randomly birefringent single-mode fibers, using polarization sensitive backscattering technique. We show analytical relationships between evolution of polarization state of backscattered signal with respect to state of polarization of forward one. Our technique allows one to measure differential group delay, beat length, and correlation length at the same time over long single-mode fibers using only one fiber end. Experimental data fit very well with numerical results, confirming the capability of our technique for fast routine characterization of PMD during cabling, before and after installation     

Lipofilling in Breast Oncological Surgery: A Safe Opportunity or Risk for Cancer Recurrence?

Lipofilling (LF) is a largely employed technique in reconstructive and esthetic breast surgery. Over the years, it has demonstrated to be extremely useful for treatment of soft tissue defects after demolitive or conservative breast cancer surgery and different procedures have been developed to improve the survival of transplanted fat graft. The regenerative potential of LF is attributed to the multipotent stem cells found in large quantity in adipose tissue. However, a growing body of pre-clinical evidence shows that adipocytes and adipose-derived stromal cells may have pro-tumorigenic potential. Despite no clear indication from clinical studies has demonstrated an increased risk of cancer recurrence upon LF, these observations challenge the oncologic safety of the procedure. This review aims to provide an updated overview of both the clinical and the pre-clinical indications to the suitability and safety of LF in breast oncological surgery. Cellular and molecular players in the crosstalk between adipose tissue and cancer are described, and heterogeneous contradictory results are discussed, highlighting that important issues still remain to be solved to get a clear understanding of LF safety in breast cancer patients.     

The coordinated automatic voltage control of the Italian transmission Grid-part I: reasons of the choice and overview of the consolidated hierarchical system

Transmission network voltage regulation through coordinated automatic control of reactive powers is now becoming a challenging objective for many utilities and system operators (ISO or TSO) to achieve significant improvements in the security, quality, and efficiency of power system operation. This survey paper is concerned with application of Secondary and Tertiary Voltage Regulations (SVR and TVR), already operating in the Italian transmission network. The basic concepts behind SVR and TVR and the related hierarchical control system are first described in terms of system characteristics, main functions and design requirements. Cost/benefit analysis and comparison with alternative voltage control solutions are also provided in relation to the influence of power system restructuring process on the voltage ancillary service. More details about control system apparatuses and their field test results are provided in Part II.     

The fluid-filling system for the Borexino solar neutrino detector

The system for controlled filling of the nested flexible scintillator containment vessels in the Borexino solar neutrino detector is described. The design and operation principles of pressure and shape monitoring systems are presented for gas filling, gas displacement by water, and water displacement by scintillator. System specifications for safety against overstressing the flexible nylon vessels are defined as well as leak-tightness and cleanliness requirements. The fluid-filling system was a major engineering challenge for the Borexino detector.     

Biomechanical evaluation of cell-loaded and cell-free hydroxyapatite implants for the reconstruction of segmental bone defects

Porous hydroxyapatite (HA) scaffoldings are currently used in tissue engineering for bone reconstruction. When this osteoconductive biomaterial is combined with osteoprogenitor cells, it acquires osteoinductive features which accelerate and improve bone formation in vivo. The aim of our study was to assess the mechanical properties of HA–bone complexes undergoing indentation tests, and relate stiffness to composition and structure as examined by micro X-ray. To this purpose, 35-mm tibia diaphyseal resections were performed in sheep. Gaps were filled using porous HA cylinders. Implants were loaded with autologous bone marrow stromal cells (BMSC); cell-free cylinders were used as control. After 8 weeks, bone tissue was found within the internal macropores of cell-loaded HA carriers, and in control implants, bone formation was mostly limited to the outer surface. As assessed by indentation testing the stiffness values of bone–HA composites were halfway between those of HA scaffoldings and tibia bone. Cell-loaded implants were stiffer than cell-free ones. In a cell-loaded implant we also analyzed the variation of stiffness along the main axis of the tibia.     

Reflections on the state of research: indoor environmental quality

More than 30 years after the First International Indoor Climate Symposium, ten researchers from the USA, Slovakia, Sweden, and Denmark gathered to review the current status of indoor environmental research. We initiated our review with discussions during the 1-day meeting and followed that with parallel research and writing efforts culminating with internal review and revision cycles. In this paper, we present our choices for the most important research findings on indoor environmental quality from the past three decades followed by a discussion of the most important research questions in our field today. We then continue with a discussion on whether there are research areas for which we can 'close the book' and say that we already know what is needed. Finally, we discuss whether we can maintain our identity in the future or it is time to team up with new partners. PRACTICAL IMPLICATIONS: In the early years of this field, the accumulated knowledge was small and it was possible for any researcher to acquire a complete understanding. To do so has become impossible today as what we know has grown to exceed the learning capacity of any person. These circumstances challenge us to work collectively to synthesize what we do know and to define clearly what remains to be learned. If we fail to do these things well, we risk repeating research without memory, an inefficiency that we cannot afford.     

Ubiquitin is conjugated to the cytoskeletal protein alpha-spectrin in mature erythrocytes

Ubiquitination of red blood cell (RBC) proteins was investigated by encapsulation of 125I-ubiquitin into human erythrocytes using a procedure of hypotonic dialysis, isotonic resealing, and reannealing. Incubation (37 degrees C, up to 2 h) of 125I-ubiquitin-loaded cells resulted in the recovery of 125I-ubiquitin with the cytosolic proteins (9.22 +/- 0.4 micrograms/ml RBC) and conjugated to membrane proteins (2.18 +/- 0.05 micrograms/ml RBC). This conjugation was time-dependent, and the predominant membrane protein band that became labeled showed an apparent molecular mass of 240 kDa on SDS-polyacrylamide gel electrophoresis (PAGE). Western blotting experiments with three different anti-ubiquitin antibodies revealed that this protein is also ubiquitinated in vivo. Cell-free experiments have shown that fraction II (a DEAE-bound protein fraction eluted by 0.5 M KCl) prepared from both mature erythrocytes and reticulocytes is able to conjugate ubiquitin to this protein. Ubiquitin conjugation was ATP-dependent (Km 0.09 mM), time-dependent, and fraction II-dependent (8 +/- 0.5 pmol of 125I-ubiquitin/h/mg of fraction II). Isolation of the major RBC membrane protein that is ubiquitinated was obtained by using biotinylated ubiquitin. Membrane proteins, once ubiquitinated with this derivative, were extracted and purified by affinity chromatography on immobilized avidin. The major components retained by the column were two peptides of molecular masses 220 and 240 kDa. Both proteins are recognized by a monoclonal anti-spectrin antibody, but only the 240-kDa component is detected by streptavidin peroxidase conjugate. That indeed the ubiquitinated membrane protein of 240-kDa is alpha-spectrin was confirmed by immunoaffinity chromatography using 125I-ubiquitin and a monoclonal anti-spectrin antibody. Antigen-antibody complexes were purified by protein A chromatography and analyzed by SDS-PAGE and autoradiography. Again two bands of 240 and 220 kDa were eluted (alpha- and beta-spectrin), but only one band corresponding to the electrophoretic mobility of alpha-spectrin was detected by autoradiography. Thus, alpha-spectrin is a substrate for the ATP-dependent ubiquitination system, suggesting that the cytoskeleton is covalently modified by ubiquitination both in reticulocytes and mature RBC.