Random multispace quantization as an analytic mechanism for BioHashing of biometric and random identity inputs

Biometric analysis for identity verification is becoming a widespread reality. Such implementations necessitate large-scale capture and storage of biometric data, which raises serious issues in terms of data privacy and (if such data is compromised) identity theft. These problems stem from the essential permanence of biometric data, which (unlike secret passwords or physical tokens) cannot be refreshed or reissued if compromised. Our previously presented biometric-hash framework prescribes the integration of external (password or token-derived) randomness with user-specific biometrics, resulting in bitstring outputs with security characteristics (i.e., noninvertibility) comparable to cryptographic ciphers or hashes. The resultant BioHashes are hence cancellable, i.e., straightforwardly revoked and reissued (via refreshed password or reissued token) if compromised. BioHashing furthermore enhances recognition effectiveness, which is explained in this paper as arising from the random multispace quantization (RMQ) of biometric and external random inputs     

A collaborative study on the determination of free amino acids in blood plasma

Collaborative work to determine the amino acid, taurine, urea and ammonia contents of a standard mixture of amino acids and of blood plasma from a preruminant and a ruminant calf was carried out at four laboratories to assess the accuracy of the ion-exchange column chromatographic technique. Samples of blood plasma were deproteinised by the organising laboratory and by the collaborating laboratories using their own methods. For the standard amino acid mixture the mean absolute deviation was 0.036 of the true concentration. This compared favourably with results from previous collaborative trials on protein hydrolysates. The mean absolute deviations were 0.192 for preruminant calf blood deproteinised by the organising laboratory and 0.159 for blood deproteinised by the collaborating laboratories. Comparable values for ruminant calf blood were 0.149 and 0.117, respectively. These results were much poorer than those obtained for protein hydrolysates and possible explanations are put forward for these different degrees of precision.     

A study of the stability of horizontal cylindrical vessels filled with varying amounts of liquid— Part I: Experimental investigations

The instability behaviour of thin-walled horizontal cylindrical vessels supported by means of ring girders, or from rigid end plates, is examined experimentally during liquid filling. Selected results from a horizontal test on a large stainless steel horizontal storage vessel are presented to illustrate the way in which thin-walled vessels, of large radius/thickness ratios (300–650), behave during fill.Such results have provided the motivation for some 26 polyester film model cylinder tests. The models cover three different radius/thickness ratios (300, 400 and 500) and a range of length/radius ratios. They were supported at their ends and progressively filled with liquid. In each case the onset of instability was noted. In Part II¹ of this paper a theoretical approach is presented and compared with the experimental values in an effort to assess the validity of design methods currently in use.     

A review of products evolved from heated coal,wood and PVC

A review is presented of the gaseous combustion and pyrolysis products evolved from coal, wood and PVC. Information has been collated on the range of products evolved, the temperatures of evolution and the effect of different ambient conditions (e.g. oxidizing of inert conditions). The data for coal have been subdivided into those from which rates of gas evolution have been or can be derived and those from which this is not possible. Probable decomposition routes for PVC and for wood are discussed. Although all three materials have been widely studied, the correlation between the work of different authors in not always good. The data obtained are dependent on the form of the experiment, and there are gaps in the information available, especially information on the rates of evolution of products of products as a function of temperature.     

A Study of the Buckling Behaviour of Horizontal Saddle Supported Vessels

Previous experimental work, by one of the authors, examined the behaviour of end supported cylindrical vessels loaded centrally. It was found that the vessels failed by buckling when the radius to thickness ratio (R/t) was greater than 150. These results provided the motivation for examining the buckling behaviour of such vessels when they are supported, in a more conventional way, by using two saddles. In the cases examined it was noted that the stresses that cause buckling behaviour are the longitudinal and circumferential membrane stresses. These occur at four vessel locations, i.e. the zenith and nadir (top and bottom) of both the vessel mid-span and the saddle centre profiles. Known buckling formulae based on simple loading patterns, such as an axially loaded cylinder and a cylinder under pure bending, will be utilized in determining the allowable buckling stress. Present British Code rules and European recommendations will also be discussed. The allowable buckling load will be compared with theoretical stresses obtained from a small displacement linear elastic analysis, using a Fourier series method. From these results a design method will be presented.     

The derivation of the stresses in a pressurised pipe or cylindrical vessel with initial geometric imperfections

Several analytical methods are outlined to deal with the title problem when the vessel is free of external constraints. In essence these correspond to the Haigh equation, which provides a nonlinear relationship between the induced circumferential stress and the applied internal pressure. To make use of these analyses a survey of the cross sectional profile is required. The approach using an internal swinging arm has been found most useful. The extent to which an improved Haigh equation is valid is examined with reference to the pneumatic loading of a twin saddle supported horizontal vessel which contains imperfections and restraints at the supports.     

Effect of slowly and rapidly degraded protein sources on the concentrations of amino acids and peptides in the rumen of steers

Four steers were given diets of straw and tapioca supplemented with urea, casein, formaldehyde treated casein (FTC), decorticated groundnut meal (DCGM), soya bean meal (SBM), maize gluten meal (MGM) or fish meal (FM) to determine the effect of degradability on rumen amino acid and peptide concentrations. Maximum concentrations of amino acid and peptide-N in rumen ultrafiltrates occurred 1 h after feeding. Total amino acid-N concentrations (mg litre^?1) at this time were low, ranging from 1.2 SE 0.8 (urea) to 15.6 SE 6.0 (casein) with little variation in individual amino acids. The peptide-N concentrations (mg litre^?1) were higher, ranging from 2.4 SE 0.5 (urea) to 160.0 SE 21.0 (casein), but were poorly correlated with degradability and solubility. Apart from casein, the highest concentrations of peptide-N were for those protein supplements, MGM (136.0 SE 25.0), FM (90.0 SE 15.0), and FTC (87.0 SE 14.0), with the lowest degradability suggesting that other factors, such as hydrophobicity, are also involved in the control of rumen peptide concentrations. Pooled samples taken 1 h after the morning feed were separated into three molecular weight (MW) fractions, 5000–50 000 da, 250–5000 da and < 250 da by gel filtration chromatography. From amino acid analysis it was found that the highest proportion of peptide-N was in the 250–5000 da fraction, and although some high MW (5000–50 000) constituents were present, only the FTC and MGM diets gave rise to significant amounts.     

Effects of river flooding on PCDD/F and PCB levels in cows' milk, soil, and grass

This paper presents the results of a study examining whether the flooding of pasture by rivers gives rise to higher PCDD/F and PCB concentrations in cows' milk. Over 180 milk, soil, and grass samples, taken from 38 farms across 3 different river systems (River Dee, Trent, and Doe Lea/Rother/Don) in the United Kingdom, were analyzed for PCDD/Fs and PCBs. The concentrations were compared between flood-prone farms, where the animals had access to pasture that is often flooded, and control farms where the land does not flood. The results indicated that concentrations of PCDD/Fs and PCBs in cows' milk were higher in samples taken from farms prone to flooding, but only from the river systems flowing through industrial and urban areas. Raised levels of PCDD/F and PCBs were also found in soil and grass from farms prone to flooding providing strong corroborative evidence that the higher concentrations in cows' milk from such areas is likely to be due to the ingestion of contaminated grass and soil. Overall, the results provide strong evidence that flooding of pastureland can indeed result in elevated concentrations of PCDD/Fs and PCBs in milk from the farms so affected.     

Brominated and chlorinated dioxins, PCBs and brominated flame retardants in Scottish shellfish: methodology, occurrence and human dietary exposure

The most commonly consumed shellfish species produced in Scotland - mussels, oysters and scallops - were investigated for the occurrence of a range of brominated and chlorinated contaminants in order to establish current levels and estimate human dietary exposure. Flesh from individual sub-samples was representatively pooled and 35 composites were analysed for brominated and chlorinated dioxins (PBDD/Fs, PCDD/Fs), brominated and chlorinated biphenyls (PBBs, PCBs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA). The analytical methodology used (13)C(12) labelled surrogates of the target compounds, with GC coupled to (usually) high resolution MS, and LC-MS/MS for HBCD and TBBPA analysis. Positive identifications were made in the majority of samples for most analytes with the exception of TBBPA and most PBDD congeners measured. None of the levels detected for PCDD/F and PCB were above the maximum permitted levels specified in European Union regulations. The levels of brominated furans predominated over brominated dioxins, reflecting the environmental distribution and source emission profiles of these contaminants, and relatively high levels of the tri-brominated congeners were observed. Levels of the flame retardant chemicals reflected current and legacy use, with appreciable concentrations of PBDEs and HBCDs (predominantly alpha-HBCD) but far lower levels of PBBs. TBBPA was not detected in any of the species. In general, mussels and oysters displayed relatively higher levels of contamination than scallops, although the gonad tissue of the latter showed significant levels of brominated dioxins. The estimated adult dietary intakes of PCDD/Fs and PCBs arising from the consumption of a typical portion of these foods in combination with an otherwise average UK diet were in the range 0.5-0.6 pg World Health Organisation (WHO)-toxic equivalent (TEQ)(2005)/kg bodyweight per day. These estimated dietary intakes are well within the Tolerable Daily Intake for dioxins and dioxin-like PCBs of 2 pg WHO-TEQ(2005)/kg bodyweight/day endorsed by the independent expert Committee on Toxicology of Chemicals in Food, Consumer Products and the Environment. The corresponding intakes for sumPBDEs and sumHBCDs were 5.6-6.1 and 5.9-7.9 ng/kg bodyweight/day respectively.