A schema for cryptographic keys generation using hybrid biometrics

Biometric identifiers refer to unique physical properties or behavioural attributes of individuals. Some of the well known biometric identifiers are voice, finger prints, retina or iris, facial structure etc. In our daily interaction with others directly or indirectly, we implicitly use biometrics to know, distinguish and trust people. Biometric identifiers represent the concept of "who a person is" by gathering vital characteristics that don't correspond to any other person. The human brain to some extent is able to ascertain disparities or variation in certain physical attributes and yet verify the authenticity of a person. But this is difficult to be implemented in electronic systems due to the intense requirements of artificial decision making and hard-coded logic. This paper examines the possibility of using a combination of biometric attributes to overcome common problems in having a single biometric scheme for authentication. It also investigates possible schemes and features to deal with variations in Biometric attributes. The material presented is related to ongoing research by the Computer Communications Research Group at Leeds Metropolitan University. We use this paper as a starting step and as a plan for advanced research. It offers ideas and proposition for implementing hybrid biometrics in conjunction with cryptography. This is work in progress and is in a very preliminary stage

Extending du Bois-Reymond's Infinitesimal and Infinitary Calculus Theory

The discovery of the infinite integer leads to a partition between finite and infinite numbers. Construction of an infinitesimal and infinitary number system, the Gossamer numbers. Du Bois-Reymond's much-greater-than relations and little-o/big-O defined with the Gossamer number system, and the relations algebra is explored. A comparison of function algebra is developed. A transfer principle more general than Non-Standard-Analysis is developed, hence a two-tier system of calculus is described. Non-reversible arithmetic is proved, and found to be the key to this calculus and other theory. Finally sequences are partitioned between finite and infinite intervals.Comment: Resubmission of 6 other submissions. 99 page

Fretting wear behaviour of MoS2 dry film lubricant

Dry film lubricants (DFL) are used as palliative coatings to prevent fretting wear. In this work fretting tests are carried out on coated Ti6Al4V cylinders on coated flat samples under dry sliding conditions, using an amplitude of 300 µm, 2.5 Hz frequency and 575 N normal loads. During the tests the coefficient of friction (CoF) was monitored, with tests being terminated when the coefficient of friction reached 0.7. Wear scars were analysed by profilometry and SEM to elucidate wear mechanisms. Results show that CoF initially increases rapidly to 0.4, this is then followed by a plateau region that finishes in a sudden step decrease in CoF following which CoF rises steadily. This behaviour is shown to be characteristic and interrupted tests are presented to allow elucidation of the wear scar at different stages in the lifetime and thus aid an understanding of the mechanisms of degradation which control the tribological behaviour

The use of Doppler velocitnetry of the utnbilical artery before 24 weeks' gestation to screen for high-risk pregnancies

Objective. To describe the prevalence and natural history of absent end-diastolic velocities (AEDV) in the mnbilical artery of the fetus between 16 and 24 weeks' gestation, and to evaluate its role as a screening test.Design. Population-based descriptive study.Setting. Tygerberg Hospital, Tygerberg, South Africa. The hospital serves a population from the lower socio-economic bracket.Subjects. Doppler velocimetry was performed at routine ultrasound examinations for confirmation of gestational age in 496 women.Main outcome measures. The occurrence of perinatal death, small-for-gestational-age (SGA) babies and proteinuric hypertension.Results. Forty-four (8,9%) patients had AEDVs at the first examination, but AEDV persisted in only 1. In this case, severe proteinuric hypertension developed unexpectedly at 29 weeks' gestation and the fetus needed delivery because ofpersistent late decelerations of the fetal heart rate pattern. There was a significant association between the group with AEDV at first examination and the development of proteinuric hypertension (P <0,05), but no association with SGA babies. The association with proteinuric hypertension was too weak to be of clinical use.Conclusion. Doppler velocimetry of the mnbilical artery, performed along with routine ultrasound examination to confirm gestational age, is not of use as a screening test for identifYing highrisk pregnancies

The tap test- an accurate First-line test for fetal lung maturity testing

Objective. To determine the accuracy of near-patient and laboratory- based fetal lung maturity tests in predicting the need for neonatal ventilation.Design. A prospective descriptive study. Subjects. One hundred high-risk obstetric patients where confirmation of fetal lung maturity would initiate delivery.Methods. Fetal weight estimation, placental maturity grading, and amniocentesis were performed. The investigators examined the amniotic fluid visually, and performed the tap test and shake test. Laboratory technicians estimated the lecithin-sphingomyelin (L/S) ratio, determined the presence of a phosphatidyl glycerol (PG) band on gel electrophoresis, and the optical density at 650 nm. Neonates delivered within 1 week of amniocentesis were included in the analysis. The primary end-point was the ability of the lung maturity tests to predict the need for neonatal ventilation.Results. Twelve of 100 neonates required ventilation. The tap test and optical density (OD) shift at 650 nm predicted the need for neonatal ventilation with the greatest accuracy.Conclusion. The tap test is a rapid, easy and accurate predictor of the need for neonatal ventilation. The OD shift at 650 nm is the laboratory-based test with the greatest accuracy in our setting

Generic Modal Cut Elimination Applied to Conditional Logics

We develop a general criterion for cut elimination in sequent calculi for propositional modal logics, which rests on absorption of cut, contraction, weakening and inversion by the purely modal part of the rule system. Our criterion applies also to a wide variety of logics outside the realm of normal modal logic. We give extensive example instantiations of our framework to various conditional logics. For these, we obtain fully internalised calculi which are substantially simpler than those known in the literature, along with leaner proofs of cut elimination and complexity. In one case, conditional logic with modus ponens and conditional excluded middle, cut elimination and complexity were explicitly stated as open in the literature

Investigating the specificity of the neurologic pain signature against breathlessness and finger opposition

Brain biomarkers of pain, including pain-predictive “signatures” based on brain activity, can provide measures of neurophysiological processes and potential targets for interventions. A central issue relates to the specificity of such measures, and understanding their current limits will both advance their development and explore potentially generalizable properties of pain to other states. Here, we used 2 data sets to test the neurologic pain signature (NPS), an established pain neuromarker. In study 1, brain activity was measured using high-field functional magnetic resonance imaging (7T fMRI, N = 40) during 5 to 25 seconds of experimental breathlessness (induced by inspiratory resistive loading), conditioned breathlessness anticipation, and finger opposition. In study 2, we assessed anticipation and breathlessness perception (3T, N = 19) under blinded saline (placebo) and remifentanil administration. The NPS responded to breathlessness, anticipation, and finger opposition, although no direct comparisons with painful events were possible. Local NPS patterns in anterior or midinsula, S2, and dorsal anterior cingulate responded to breathlessness and finger opposition and were reduced by remifentanil. Local NPS responses in the dorsal posterior insula did not respond to any manipulations. Therefore, significant global NPS activity alone is not specific for pain, and we offer insight into the overlap between NPS responses, breathlessness, and somatomotor demand

The development of the human aspects of information security questionnaire (HAIS-Q)

The Human Aspects of Information Security Questionnaire (HAIS-Q) is being developed using a hybrid inductive, exploratory approach, for the purpose of evaluating information security threats caused by employees within organisations. This study reports on the conceptual development and pre-testing of the HAIS-Q. Results from 500 Australian employees were then used to examine the reliability of the HAIS-Q, as well as the relationships between knowledge of policy and procedures, attitude towards policy and procedures and behaviour when using a work computer. Results indicate significant, positive relationships between all variables. However, both qualitative and quantitative results indicate the direct influence of knowledge of policy and procedure accounted for far less of the variance in self-reported behaviour than attitude towards policy and procedure. Implications for training and education campaigns and plans for future research to further develop this questionnaire are outlined

Opioid suppression of conditioned anticipatory brain responses to breathlessness

Opioid painkillers are a promising treatment for chronic breathlessness, but are associated with potentially fatal side effects. In the treatment of breathlessness, their mechanisms of action are unclear. A better understanding might help to identify safer alternatives. Learned associations between previously neutral stimuli (e.g. stairs) and repeated breathlessness induce an anticipatory threat response that may worsen breathlessness, contributing to the downward spiral of decline seen in clinical populations. As opioids are known to influence associative learning, we hypothesized that they may interfere with the brain processes underlying a conditioned anticipatory response to breathlessness in relevant brain areas, including the amygdala and the hippocampus. Healthy volunteers viewed visual cues (neutral stimuli) immediately before induction of experimental breathlessness with inspiratory resistive loading. Thus, an association was formed between the cue and breathlessness. Subsequently, this paradigm was repeated in two identical neuroimaging sessions with intravenous infusions of either low-dose remifentanil (0.7ng/ml target controlled infusion) or saline (randomised). During saline infusion, breathlessness anticipation activated the right anterior insula and the adjacent operculum. Breathlessness was associated with activity in a network including the insula, operculum, dorsolateral prefrontal cortex, anterior cingulate cortex and the primary sensory and motor cortices. Remifentanil reduced breathlessness unpleasantness but not breathlessness intensity. Remifentanil depressed anticipatory activity in the amygdala and the hippocampus that correlated with reductions in breathlessness unpleasantness. During breathlessness, remifentanil decreased activity in the anterior insula, anterior cingulate cortex and sensory motor cortices. Remifentanil-induced reduction in breathlessness unpleasantness was associated with increased activity in the rostral anterior cingulate cortex and nucleus accumbens, components of the endogenous opioid system known to decrease the perception of aversive stimuli. These findings suggest that in addition to effects on brainstem respiratory control, opioids palliate breathlessness through an interplay of altered associative learning mechanisms. These mechanisms provide potential targets for novel ways to develop and assess treatments for chronic breathlessness