A proposal for statistical evaluation of the detection of gunshot residues on a suspect

The possibility of accidental contamination of a suspect by gunshot residues (GSRs) is considered. If two hypotheses are taken into account ("the suspect has shot a firearm" and "the suspect has not shot a firearm"), the likelihood ratio of the conditional probabilities of finding a number n of GSRs is defined. Choosing two Poisson distributions, the parameter lambda of the first one coincides with the mean number of GSRs that can be found on a firearm shooter, while the parameter mu of the second one is the mean number of GSRs that can be found on a nonshooter. In this scenario, the likelihood ratio of the conditional probabilities of finding a number n of GSRs in the two hypotheses can be easily calculated. The evaluation of the two parameters lambda and mu and of the goodness of the two probability distributions is performed by using different sets of data: "exclusive" lead-antimony-barium GSRs have been detected in two populations of 31 and 28 police officers at diverse fixed times since firearm practice, and in a population of 81 police officers who stated that they had not handled firearms for almost 1 month. The results show that the Poisson distributions well fit the data for both shooters and nonshooters, and that the probability of detection of two or more GSRs is normally greater if the suspect has shot firearms.     

Q-FIHC: quantification of fluorescence immunohistochemistry to analyse p63 isoforms and cell cycle phases in human limbal stem cells

Fluorescence microscopy has long been used for qualitative characterization of various parameters such as subcellular distribution of proteins, lipids, nucleic acids, and ions. However, quantification of these parameters is complicated by a variety of optical, biological, and physical factors. In the last decade, the progress achieved with powerful softwares and digital image processing systems has facilitated the development of fluorescence immunohistochemistry (FIHC) into a widely used quantitative assay (quantitative-FIHC or Q-FIHC). We describe here a rapid and sensitive Q-FIHC assay based on the use of a laser scanning confocal microscope and advanced image analysis softwares (Zeiss semi automatic LSM 510 and fully automatic Axiovision 4.4) for the detection and quantification of fluorescent intensity in human corneal tissues and cells obtained from small clinical samples. We have used this methodology to characterize and quantify the gene expression profile of p63 and its DeltaNalpha isoform, specific markers of human limbal stem cells. The validity of this method was evaluated through comparative studies with conventional approaches suggesting no significant differences and providing an alternative technique to traditional methods. Since Q-FIHC requires at least 20-fold less cells than traditional techniques, we have adopted it as the main quality control for our limbal cultures destined to clinical application.     

Copolymerization of styrene and methyl methacrylate with nickel acetylacetonate/methylaluminoxane catalyst system

The present work deals with copolymerization of styrene (STY) and methyl methacrylate (MMA) catalysed by nickel acetylacetonate - Ni(acac) ₂ , employing methylaluminoxane (MAO) as cocatalyst. This catalyst system presented low catalyst activities for STY homopolymerization and very high activities for MMA. It seems that the catalyst system based on Ni(acac) ₂ /MAO is effective for the copolymerization of MMA and STY to give block copolymer but it also produced polystyrene and poly(methyl methacrylate) homopolymers. The polymers were characterized by ¹³ C NMR, GPC and FTIR. The polystyrene homopolymer was identified by IR and NMR analyses of the cyclohexane soluble fraction. The presence of absorption bands correspondent to carbonyl group and aromatic ring was observed in the IR spectrum of the acetic acid soluble part. This result is a clue that STY-MMA copolymer with low molecular weight was produced. The high molecular weight copolymer (acetic acid insoluble fraction) was also characterized by IR analysis which indicated the presence of characteristic absorption bands of carbonyl group and aromatic ring. These results were confirmed by ¹³ C NMR analysis. Received: 6 August 1997/Revised version: 29 December 1997/Accepted: 7 January 1998     

Corrosion of a Dense, Low-additive Si3N4 in High Temperature Combustion Gases

The oxidation/corrosion resistance of silicon nitride is determined by a number of factors, most notably the amount and chemical composition of the grain boundary phases produced as a result of adding oxides to promote densification during sintering/hot pressing. The intergranular material may be very active during high temperature exposure, producing a deleterious effect on the oxidation/corrosion processes. A method for producing silicon nitride with low levels of additives (only 0·59% Al₂O₃ and 1·22% Y₂O₃) and the benefits in terms of corrosion behaviour are described in this paper. The results of tests in combustion gases, where the concentration of sulphur in the fuel and contaminants in the ingested air have particular effects on the rate of corrosion, are reported.     

Natural gas flow computer with open architecture using intelligent instrumentation and field bus

A new approach to natural gas flow computer design is presented in this paper. The developed system runs on a personal computer and employs the state-of-the-art mathematical models for corrections of some aspects of fluid flow dynamics, as well as for compressible behavior of gaseous fluid considerations. Orifice plates were used as primary elements. Measurements were performed through intelligent sensors. Results of the system metrological tests are also presented.     

Equivalent circuit modeling of electrokinetically driven analytical microsystems

Equivalent circuit modeling of microfluidic chips accounts for the transport of fluid and electricity in the entire network of microchannels as a function of the applied pressure and electric potentials. For these calculations, each microchannel is represented by a set of conductance coefficients that relates to driving forces and conjugate flows. Theoretical expressions of the coefficients for rectangular microchannels with arbitrary values of the cross-sectional aspect ratio are derived from the fundamentals of electrokinetic phenomena. Particular emphasis is placed on the analysis of the conditions under which the equivalent circuit model can be accurately employed. Model predictions successfully match data on electrokinetically driven chips for immunoassays reported in the literature. A simulation example is also given to illustrate the capability of the technique for the design and manipulation of analytical microsystems.     

Design space exploration of an open-source, IP-reusable, scalable floating-point engine for embedded applications

This paper describes an open-source and highly scalable floating-point unit (FPU) for embedded systems. Our FPU is fast and efficient, due to the high parallelism of its architecture: the functional units inside the datapath can operate in parallel and independently from each other. A comparison between different versions of the FPU has been made to highlight how performance scales accordingly. Logic synthesis results show that our FPU requires 105 Kgates and runs at 400 MHz on a low-power 90 nm std-cells low-power technology, and requires 20 K Logic Elements running at 67 MHz of an Altera Stratix FPGA. The proposed FPU is supported by a software tool suite which compiles programs written using the C/C++ language. A set of DSP and 3D graphics algorithms have been benchmarked, showing that using our FPU the amount of clock cycles required to perform each algorithm is one order of magnitude smaller than what is required by its corresponding software implementation.     

Characterization of threshold-induced phenomena in deterministic driven devices

In the field of measurement nonlinear behavior is typical of a large set of sensors (mechanical, electrical, pneumatic, and so on). In several devices, SQUID and piezoelectric sensors being very well-known examples, the nonlinearity is strictly correlated to the hysteresis phenomenon, which can be described by introducing the quartic double well (QDW) potential in the system model. The analysis addresses the influence of potential characteristics on the performance of hysteretic measuring devices. A Brownian system with a QDW potential is used as a general prototype of hysteretic phenomena. This paper applies to the general class of hysteretic devices forced with low-amplitude signals and gives suitable outlines for the design of several measuring devices.     

Development of functionalized Fe–Al–Cr alloy fibers as innovative catalytic oxidation devices

Catalytic devices play a very important role to drastically reduce the noxious contaminants released by the combustion engines. Common devices consist of functionalized ceramic monoliths; an interesting alternative can be realized with a support material made of a high temperature compatible metal alloy, like FeCrAl. In the present study the FeAlCr fibers used to make a device similar to the ceramic monolith were thermally treated to obtain alumina whiskers, which were homogenously covered with alumina or ceria–zirconia–alumina washcoats. Pt or Pt and Pd have been loaded over the functionalized fibers obtaining an innovative oxidation catalyst. The systems were characterized by BET surface area measurements, hydrogen chemisorption and tested under high space velocity and fast heating run-up cycles, for hydrocarbon and CO conversion and particulate filtration ability. The good catalytic activity after severe aging treatments confirms the possibility of use of these innovative functionalized metallic stacks in air pollution control applications.     

Effects of pressure toasting on in situ degradability and intestinal protein and protein‐free organic matter digestibility of rapeseed

BACKGROUND: Rapeseed is a protein supplement that contains up to 40% crude protein (CP) on a dry matter (DM) basis, but a large part of its protein can be easily degraded in the rumen. Therefore, before inclusion in ruminant's diet, the extent of its protein degradation in the rumen must be reduced without altering its intestinal digestibility. A study was conducted to investigate the effects of pressure toasting (T, 130 °C) at two residence times (1.5 and 10 min) alone or in combination with soaking in water (ST, 4 h) on ruminal degradability and intestinal digestibility of CP and protein‐free organic matter (PFOM) in whole full‐fat rapeseed. RESULTS: Regardless of the processing time (1.5 or 10 min), T significantly (P < 0.05) increased the fraction of undegraded intake protein (UIP) compared to the untreated rapeseed samples. Soaking prior to further toasting did not improve the rumen degradation characteristics of rapeseed CP. Compared to the untreated rapeseed samples, both T and ST significantly (P < 0.0001) improved the true protein digested in the small intestine (DVE) and degraded protein balance (OEB), effects that were more evident in samples heated for 10 min. Soaking prior to pressure toasting, however, did not further improve the DVE or OEB in the rapeseed samples in comparison with T treatment. CONCLUSIONS: It was concluded that ruminal protein degradability of rapeseed decreased after pressure toasting, without seriously affecting its intestinal digestibility. Copyright © 2008 Society of Chemical Industry