A unified framework for finite-memory detection

In this paper, we present a general approach to finite-memory detection. From a semi-tutorial perspective, a number of previous results are rederived and new insights are gained within a unified framework. A probabilistic derivation of the well-known Viterbi algorithm, forward-backward, and sum-product algorithms, shows that a basic metric emerges naturally under very general causality and finite-memory conditions. This result implies that detection solutions based on one algorithm can be systematically extended to other algorithms. For stochastic channels described by a suitable parametric model, a conditional Markov property is shown to imply this finite-memory condition. This conditional Markov property, although seldom met exactly in practice, is shown to represent a reasonable and useful approximation in all considered cases. We consider, as examples, linear predictive and noncoherent detection schemes. While good performance for increasing complexity can often be achieved with a finite-memory detection strategy, key issues in the design of detection algorithms are the computational efficiency and the performance for limited complexity.     

The codon 213 of the 11beta-hydroxysteroid dehydrogenase type 2 gene is a hot spot for mutations in apparent mineralocorticoid excess

In the kidney, the 11beta-hydroxysteroid dehydrogenase type 2 enzyme (11betaHSD2) inactivates glucocorticoids to their inactive ketoforms and thus prevents endogenous glucocorticoids from occupying the nonselective mineralocorticoid receptor in epithelial tissues. Several mutations have been described in the 11betaHSD2 gene in the congenital syndrome of apparent mineralocorticoid excess. These mutations generate partially or completely inactive 11betaHSD2 enzymes. In the present work, we describe an already known mutation in a new patient affected by apparent mineralocorticoid excess, which results in an arginine-to-cysteine mutation (R213C) in the 11betaHSD2 enzyme. This mutation has been found in two other independent families. In vitro expression studies of this mutant provide evidence that the mutant protein is normally expressed, but its activity is abolished. The CGC-to-TGC (C-toT) transition at codon 213 can be considered a typical CpG-consequence mutation. The present finding suggests that the codon R213 of 11betaHSD2 is a hot spot for mutations in this gene, as shown by the occurrence of an R213C point-mutation in several families unrelated to each other.     

Program Behavior

Among the performance characteristics of programs, the patterns of memory references they generate have the unique property of being totally irrelevant in a non-virtual memory context and perhaps the most important aspect of program behavior in a virtual memory system. It is because of their importance in the latter case that the referencing behavior is so often referred to as the "behavior" par excellence.     

High-order ergodicity of a complex harmonic process

The paper deals with high-order moment-ergodic properties of a complex process composed of superimposed sinusoids. This is efficiently achieved using a state-space representation of the signal and Kronecker algebra. First, a simple formulation of the stationarity hypothesis is given, and finally, the moment-ergodic theorem for the associated moments is derived     

Involvement of hormonal circadian secretion in the growth of HIV-infected children

A series of novel serine derived NK1 antagonists is described. The effect of variations in the N-benzyl, O-benzyl and serine groups are used to define the elements which are necessary for binding.     

Latency of evoked neuromagnetic M100 reflects perceptual and acoustic stimulus attributes

The latency of components of the auditory evoked neuromagnetic field has been shown to reflect, or encode, stimulus attributes. In particular, the M100 component, occurring approximately 100 ms post stimulus onset has a latency that depends on stimulus pitch, spectral complexity and presentation level. This study used magnetoencephalography to record neuromagnetic fields evoked by presentation of two-tone complexes consisting of various proportions of 100 Hz and 1 kHz energy. These are perceived categorically, as evidenced by classification and reaction time measurements. It is found that the M100 latency also varies categorically, that is, characterized by two plateau regions with a sharp interface. Thus, we find that not only does the M100 latency reflect acoustic attributes of a stimulus, but also such perceptual characteristics.     

Characterizing and reproducing working set size dynamics

A characterization of program referencing dynamics based on the temporal behavior of memory demand (as represented by the working set size of a program for a given window size) is proposed. A deterministic generative model which produces a references string having a given dynamic characterization is then presented, and its practical implementation is discussed. An experimental study of the accuracy and the viability of such a model is performed, together with a theoretical and empirical investigation of the feasibility of constructing a synthetic program which produces an approximation to that artificial string, thereby exhibiting the given dynamic behavior. The results for working-set-like environments with window sizes larger than or equal to that used in the generation of the artificial string are satisfactory, but those for other types of memory policies reveal that improvements to the string generation algorithm or different characterizations are needed.     

Neoadjuvant chemotherapy for extremity osteosarcoma--preliminary results of the Rizzoli''s 4th study

OBJECTIVES: Our study was designed to clarify the role of the thalamus in the generation of the electrically elicited long-latency reflexes (LLR) in voluntarily activated hand muscles. MATERIALS AND METHODS: EMG responses of the thenar muscles were evoked by electrical stimulation of the median nerve at the wrist at motor threshold intensity in 10 patients with acute pure sensory stroke due to thalamic infarction. Concomitant recording of somatosensory evoked potentials (SEPs) was performed. The subjects were asked to steadily abduct the thumb at 20-30% of maximal force against a force transducer. Rectified and averaged EMG activities were recorded. RESULTS: The LLR II was missing completely or significantly attenuated in the majority of the patients (9 of 10), of whom 3 also had delayed latency. Abnormal SEPs were documented in 7 patients (7 of 10). In the follow-up, 5 patients had partial reversal of LLR II. LLR II was still pathological in 1 fully recovered patient. CONCLUSION: Our results further confirm the transcortical generation of LLR II and imply that a thalamic relay is present in the afferent limb of the LLR.     

A new polymorphic restriction site in the human 11 beta-hydroxysteroid dehydrogenase type 2 gene

The 11 beta-hydroxysteroid dehydrogenase type II enzyme (11 beta HSD2) inactivates glucocorticoids in the kidney and thus prevents glucocorticoids from occupying the non-selective mineralocorticoid receptor in epithelial tissues. Mutations in the HSD11B2 gene have been found to cause the syndrome of apparent mineralocorticoid excess, a rare autosomal recessive disease characterized by severe hypertension. Thus, this locus could also be an ideal candidate involved in the etiology of primary hypertension. We identified a polymorphism in exon 3 characterized by a GAG to GAA transition at codon 178, with the loss of an Alu I restriction site and analysed it in an association study using end-stage renal disease patients, diabetic or essential hypertensive patients and control subjects. Two-hundred and eighty nine subjects and patients were analysed; the genotype was determined by amplification of genomic DNA and subsequent digestion with Alu I restriction enzyme. The prevalence of the Alu I allele was 8.6% in healthy control subjects (n = 116). This prevalence was lower (chi 2 P = 0.035 vs. controls) than the 18.0% in a group of renal transplant patients (n = 61). The corresponding values for patients with diabetes mellitus (n = 25), hypertension (n = 41) and patients on dialysis (n = 46) were 4.0%, 4.8% and 4.3%, respectively. There was no correlation between blood pressure and the marker in non-ESRD subjects. These data indicate the presence of a polymorphic marker in exon 3 of the HSD11B2 gene; this marker is associated with end-stage renal disease but not with essential hypertension in humans.