Implementation of Biometric Systems — Security and Privacy Considerations

As biometric systems are deployed within security systems, or as part of identification programs, implementation issues relating to security and privacy need to be considered. The role of a biometric system is to recognize (or not) an individual through specific physiological or behavioral traits. The use of the word ‘recognize’ is significant — defined in the Oxford Dictionary as “identify as already known”. In other words, a biometric system does not establish the identity of an individual in any way, it merely recognizes that they are who they say they are (in a verification or a ‘positive identification’ system), or that they were not previously known to the system (in a ‘negative identification’ system, for example, to avoid double enrollment in a welfare system). This tie between the actual identity of an individual and the use of biometrics is subtle and provokes much debate, particularly relating to privacy and other societal issues. This paper seeks to clarify come of these issues by providing a framework, and by distinguishing between technology and societal issues.     

The Variety of Variables in Computer-Aided Real-Time Programming

The refinement calculus is a well-established theory for translating specifications to program code. Recent research has extended the calculus to handle real-time requirements and we have developed an interactive support tool based on these extensions. Via a case study, this paper shows how the tool helps the programmer by supporting the many forms of variables used in the theory. These include simple state variables as in the untimed calculus, timed-trace variables that model the evolution of properties over time, and auxiliary variables that exist to support formal reasoning only.     

Effects of waterlogging at different stages of development on the growth and yield of winter wheat

The response of winter wheat to waterlogging at different stages of growth outdoors was studied for 3 years using lysimeters containing undisturbed monoliths of sandy loam and clay soils. The treatments were selected as the most extreme likely to occur in field conditions in Britain, i.e. waterlogging to the soil surface for up to 16 days in October, 42 days in January and February and 6 days in May. Waterlogging in midwinter was common to all experiments. Yield losses from mid-winter waterlogging ranged from 15% when yields were heavy (10 t ha^?1), to nil when yields were light (3-4 t ha^?1) after the plants had been affected by frost damage in late winter and by take-all. Winter wheat was most sensitive to waterlogging after germination but before emergence. At this stage, 16 days waterlogging killed all seedlings and 6 days waterlogging depressed plant populations to 12% (clay) and 38% (sandy loam) of the control. However, there was vigorous compensatory growth in the remainder of the growing season and yield was only depressed to about 82% of the control. When the crop was waterlogged at any stage after emergence plant populations were not affected; however, winter waterlogging treatments usually depressed shoot numbers and, to a lesser extent, ear numbers at harvest. Shoot survival under waterlogged conditions seemed related to nitrogen availability in the soil. The amount of ‘take-all’ (Gaeumannomyces graminis var. tritici) was increased by waterlogging.     

Filtre passe-bande antimétrique paramétrique

In a first time, the paper shows that the antimetric parametric filters with a single passband exist only with an even number of free parameters. In a second time, it gives a method for the determination of attenuation formula in this last case.     

On Modeling the Single Motor Unit Action Potential

A model has been proposed for the generation of single motor unit potentials routinely observed in the clinical EMG examination of the normal biceps brachii muscle. A dipole representation was chosen for the single fiber activity. The motor unit was constructed from a uniform random array of single fibers. Motor unit potentials generated by this array have been observed at various distances both inside and outside the array. The effects of single fiber dipole axial dispersions on the potentials observed at increasing distances from the array have also been investigated. Motor unit potentials generated by the model have been compared with existing data from multielectrode studies in the biceps brachii.     

Preparation of3H-phosphatidylmyoinositol withKloeckera brevis

The growth ofKloeckera brevis in the presence of uniformly tritiated myoinositol is described. The major radioactive lipid isolated from the cells is³H-phosphatidylmyoinositol, labeled exclusively in the myoinositol moiety. Chromatographic methods for purifying³H-phosphatidylmyoinositol, free from other labeled lipids, are described, and the use of this labeled lipid as a precursor in studying enzymatic synthesis of complex inositol lipids is demonstrated.     

The extended jones—dole equation

A number of authors have recently interpreted the relative viscosities of electrolytic solutions in terms of an extended Jones—Dole equation containing a term Dc²:

The B-coefficients resulting from such analyses are not directly comparable with those arising from the simple Jones—Dole expression because of the high negative correlation between the B and D terms. There is therefore some difficulty in relating results from both types of analysis. In this paper a number of data sets are examined statistically with a view to establishing a standard procedure for obtaining estimates of the B-coefficients which relate exclusively to the linear term and are not influenced by the effect of higher terms. Two methods which recognize the high correlation of B and D terms are suggested.     

Salmonella carriage in an Irish pig herd: correlation between serological and bacteriological detection methods

Salmonella carriage in pigs represents a serious health problem that undoubtedly contributes to the spread of human disease. Thus, the efficient and reliable testing of farm animals for bacteria such as Salmonella is an important aspect of any efficient control strategy. Serological analysis of 15 meat juice samples detected antibodies against Salmonella in some. but not all, of the animals identified bacteriologically as harboring the pathogen, indicating a lack of correlation between the bacteriological and serological methods used for Salmonella detection. The results suggest that testing by enzyme-linked immunosorbent assay is appropriate at the herd level, with culture methods preferable for individual animal analysis. A novel culture protocol detected Salmonella in the cecal contents of 15 pigs, whereas a method based on the European Standard identified only 9 pigs as being Salmonella-positive. During the study, an unusual finding was the relatively high incidence of Salmonella London carriage in the pigs tested.