Evidence for superantigen involvement in insulin-dependent diabetes mellitus aetiology

Insulin-dependent diabetes mellitus (IDDM) is a T-cell-mediated autoimmune disease whose onset is believed to be triggered by unknown environmental factors acting on a predisposing genetic background. Islet-infiltrating T (IIT) cells from two IDDM patients, who had died at the onset of the disease from brain swelling as a complication of ketoacidosis, were analysed. The results provided evidence for the involvement of a pancreatic islet cell membrane-bound superantigen as a diabetes aetiopathogenetic factor. There was a selective expansion of a T-cell receptor (TCR) variable segment of the beta-chain (V beta 7) in these IIT cells in association with unselected V alpha-chain segments; extensive junctional diversity of the TCR V beta 7 chains; and evidence of positive selection, after exposure to diabetic islet cell membrane preparations, of V beta 7+ T-cell clones among peripheral blood lymphocytes from non-diabetic individuals.     

A negative association of schizophrenia with an allele of the HLA DQB1 gene among African-Americans

The present study investigated the relationship between the time of nocturnal onset of urinary 6-sulfatoxymelatonin (aMT6s) secretion, and the timing of the steepest increase in nocturnal sleepiness ("sleep gate"), as determined by an ultrashort sleep-wake cycle test (7 min sleep, 13 min wake). Twenty-nine men (mean age 23.8 +/- 2.7 years) participated. The ultrashort sleep-wake paradigm started at 0700 hr after a night of sleep deprivation and continued for 24 hr until 0700 hr the next day. Electrophysiological recordings were carried out during the 7-min sleep trials, which were then scored conventionally for sleep stages. Urinary aMT6s was measured every 2 hr. The results showed that the timing of the sleep gate was significantly correlated with the onset of aMT6s secretion. These results are discussed in light of the possible role of melatonin in sleep-wake regulation.     

Risk analysis of underground infrastructures in urban areas

The paper presents an integrated approach for vulnerability and resilience analysis for underground infrastructures, i.e. a societal risk analysis of the failures of underground services for an urban area. The approach is based on the detailed study of (1) domino-effects for the components of a single infrastructure and for a given set of infrastructures interoperated and/or belonging to the same area; (2) risk and vulnerability analysis of a given area; (3) identification of a set of intervention guidelines, in order to improve the overall system resilience. The use of an integrated (interoperability and area) approach, breaking down the analysis area extent into sub-areas and assessing the dependencies among sub-areas both in terms of interoperability and damage propagation of critical infrastructures, demonstrates a useful advantage in terms of resilience analysis, more consistent with the “zoned” nature of failures of the underground infrastructures. An applied case, describing the interoperability and damage propagation analysis with the evaluation of time-dependency for the infrastructures and targets and of different kinds of interventions of the underground infrastructures of a town, is presented for this purpose.     

Evidence for a heterozygote advantage in congenital adrenal hyperplasia due to 21-hydroxylase deficiency

21-Hydroxylase deficiency is one of the most common inherited disorders, with carrier frequencies of approximately 10% in all world populations studied to date. The high prevalence of the mutant gene is probably due to a flanking pseudogene serving as a reservoir for mutations. Despite the potential for a high rate of de novo mutations, a founder effect for specific gene conversions is observed in most populations. We hypothesized that there was a survival advantage to 21-hydroxylase heterozygotes, and here we report endocrinological and molecular investigations to test this hypothesis. We defined 28 carriers and 22 mutation-negative controls by molecular genotyping and determined ACTH-stimulated adrenal hormone responses. We found significantly elevated cortisol responses in the carriers compared to controls (30 min cortisol levels: normal, 24.2 +/- 4.6 micrograms/dL; carrier, 28.1 +/- 4.2 micrograms/dL; P < 0.005). Cortisol has a crucial role in maintaining homeostasis, influencing differentiation, suppressing inflammation, and effecting cross-talk among the immune, nervous, and endocrine systems. The brisk cortisol response we have documented in carriers of 21-hydroxylase may enable a rapid return to homeostasis in response to infectious, inflammatory, or other environmental stresses and may protect from inappropriate immune responses, such as autoimmune diseases.     

Determination of protein in fish meal

A comparison of the Kjeldahl and Lowry methods for the determination of protein in fish meal has been made. The values obtained with the rapid colorimetric Lowry method, using extracts of total fish meal proteins, were lower than those obtained by the Kjeldahl method. For fish meal from different species the general factor 1.19±0.03 (confidence limit for P<0.01) may be used to convert protein values obtained by the Lowry method into protein values obtained by the Kjeldahl method.     

Improving Depth Image Acquisition Using Polarized Light

Control of the source and analysis of the polarization properties of the reflected light in a laser rangefinder based on triangulation offer a potential solution to the problem of distinguishing the primary laser stripe from unwanted inter-reflections caused by holes and concavities on metal surfaces. In this paper, the established polarization theory of first and subsequent inter-reflections from metallic surfaces is reviewed. This provides a point of comparison for ellipsometric measurements which verify the particular applicability of the microfacet surface model in our context. We demonstrate how a conventional laser rangefinder can be modified to discriminate between primary and secondary reflections. However, our experiments on third and subsequent reflections show that more complex models are required to provide complete resolution of the problem. Furthermore, error analysis demonstrates the requirement for very precise control of the source and receiving optoelectronics. We conclude by demonstrating the acquisition of a depth image with and without polarization optics and discuss the significance of our results for laser depth measurement.     

Markov-based methodology for the restoration of underwater acoustic images

This article describes a probabilistic technique for the restoration of underwater acoustic images that is based on the Markov random fields (MRFs) methodology. The beamforming is applied to rough acoustic data that derive from multibeam systems or acoustic cameras to build a three-dimensional (3D) map, that is associated point by point with the estimates of the reliability of such measures. Specifically, backscattered echoes that are received by a 2D array antenna are arranged to generate two images in which each pixel represents the distance (range) from the sensor plane and the confidence of the measures, respectively. Unfortunately, this kind of image is affected by several problems due to the nature of the signal and the related sensing system. In the proposed algorithm, the range and the confidence images are modeled as separate MRFs whose associated probability distributions embed knowledge of the acoustic system, of the considered scene, and of the noise affecting the measures. In particular, the confidence image is first restored and the result is used to reconstruct the 3D image to allow an active integration of the reliability information. Optimal (in the maximum a posteriori probability sense) estimates of the reconstructed 3D map and the restored confidence image are obtained by minimizing the energy functionals, using simulated annealing. Experimental results on synthetic and real images show the performance of the proposed approach. © 1997 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 8, 386–395, 1997     

RERBEE: robust efficient registration via bifurcations and elongated elements applied to retinal fluorescein angiogram sequences

We present RERBEE (robust efficient registration via bifurcations and elongated elements), a novel feature-based registration algorithm able to correct local deformations in high-resolution ultra-wide field-of-view (UWFV) fluorescein angiogram (FA) sequences of the retina. The algorithm is able to cope with peripheral blurring, severe occlusions, presence of retinal pathologies and the change of image content due to the perfusion of the fluorescein dye in time. We have used the computational power of a graphics processor to increase the performance of the most computationally expensive parts of the algorithm by a factor of over × 1300, enabling the algorithm to register a pair of 3900 × 3072 UWFV FA images in 5-10 min instead of the 5-7 h required using only the CPU. We demonstrate accurate results on real data with 267 image pairs from a total of 277 (96.4%) graded as correctly registered by a clinician and 10 (3.6%) graded as correctly registered with minor errors but usable for clinical purposes. Quantitative comparison with state-of-the-art intensity-based and feature-based registration methods using synthetic data is also reported. We also show some potential usage of a correctly aligned sequence for vein/artery discrimination and automatic lesion detection.     

Markerless human articulated tracking using hierarchical particle swarm optimisation

In this paper, we address markerless full-body articulated human motion tracking from multi-view video sequences acquired in a studio environment. The tracking is formulated as a multi-dimensional non-linear optimisation and solved using particle swarm optimisation (PSO), a swarm-intelligence algorithm which has gained popularity in recent years due to its ability to solve difficult non-linear optimisation problems. We show that a small number of particles achieves accuracy levels comparable with several recent algorithms. PSO initialises automatically, does not need a sequence-specific motion model and recovers from temporary tracking divergence through the use of a powerful hierarchical search algorithm (HPSO). We compare experimentally HPSO with particle filter (PF), annealed particle filter (APF) and partitioned sampling annealed particle filter (PSAPF) using the computational framework provided by Balan et al. HPSO accuracy and consistency are better than PF and compare favourably with those of APF and PSAPF, outperforming it in sequences with sudden and fast motion. We also report an extensive experimental study of HPSO over ranges of values of its parameters.     

FUR: Understanding functional reasoning

By functional reasoning we mean the ability of integrating shape, function, and plans in reasoning. the shape of many man-made objects, such as tools, is expressly designed to provide precise functionalities. Moreover, humans know how to use the same objects for different functions. In vision and reasoning we make use of complex information which is not exclusively based on geometric and spatial knowledge, but also on functional elements. They seem to play a role in object recognition and representation. This article is an insight in functional reasoning from the computational point of view. It introduces its concepts and its apparent ubiquity in human behavior. Some relevant computational literature is reported and discussed. the rest of the article is an outline of the FUR project, an attempt to develop a computational model for functional reasoning. the development state of the project is presented along with the implementation of a first prototype. Some experimental results are finally given.