Radiosity with Well Distributed Ray Sets

In this paper we present a new radiosity algorithm, based on the notion of a well distributed ray set (WDRS). A WDRS is a set of rays, connecting mutually visible points and patches, that forms an approximate representation of the radiosity operator and the radiosity distribution. We propose an algorithm that constructs an optimal WDRS for a given accuracy and mesh. The construction is based on discrete importance sampling as in previously proposed stochastic radiosity algorithms, and on quasi Monte Carlo sampling. Quasi Monte Carlo sampling leads to faster convergence rates and the fact that the sampling is deterministic makes it possible to represent the well distributed ray set very efficiently in computer memory. Like previously proposed stochastic radiosity algorithms, the new algorithm is well suited for computing the radiance distribution in very complex diffuse scenes, when it is not feasible to explicitly compute and store form factors as in classical radiosity algorithms. Experiments show that the new algorithm is often more efficient than previously proposed Monte Carlo radiosity algorithms by half an order of magnitude and more.     

Review of Cliniques de thérapie comportementale.

Reviews the book, Cliniques de thérapie comportementale/Clinical behavioral therapy edited by O. Fontaine, J. Cottraux, and R. Ladouceur (1985). This book is a work which seeks to fill a vacuum while proposing to illustrate in a concrete manner how the behaviorist acts in his daily practice. It comprises 25 chapters which frequently illustrate this pragmatic prospect within the framework for pathologies used in behavioral private clinics, from infantile autism to dementia in old age, while passing by depression, alcoholism, chronic pain, etc. This book is the result of the collaboration of about thirty specialists of reputation: Beligian, Canadian, French and Swiss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Swiss journey through the clinical and genetic characteristics of diabetes in young patients

The aim of this study is to understand better the genetic causes of type II diabetes and the phenotypic consequences of the genetic changes. We first investigated the relative prevalence of the different forms of diabetes in young adults and their clinical features. 51 non-obese patients were identified in whom diabetes had been diagnosed before age 40; cases of typical insulin-dependent type I diabetes were excluded. A search for mutations of the glucokinase and HNF-1 alpha genes and for mitochondrial DNA was made, anti-islet and anti-GAD antibodies were determined and HLA class II genotyping was performed. Patients were subdivided on clinical grounds into a MODY (maturity onset diabetes of the young) group (n = 19) and a non-MODY group (n = 32). MODY is a form of diabetes which has an autosomal dominant inheritance for which 3 genes have already been implicated (MODY1, HNF-4 gene; MODY2, glucokinase gene, and MODY3, HNF-1 alpha gene). In the MODY group we identified 3 patients with MODY2, 1 with MODY3, 1 with the 3243 mitochondrial mutation and a further patient with autoimmune diabetes. In the non-MODY group we found 5 patients with autoimmune diabetes and 1 with MODY2. No clinical parameter was helpful in classifying patients in one of these subclasses of diabetes; however, glucagon stimulated C-peptide was useful in discriminating between MODY2 patients and the others. Young and lean non-insulin-dependent diabetic patients thus constitute a very heterogeneous group, though presenting similar clinical features. In the second study we analyzed hepatic glucose metabolism in patients with a mutation of the glucokinase gene expressed in both liver and islet beta cells. We found that endogenous glucose production is inadequately inhibited by hyperglycemia, a fact which contributes to the pathogenesis of hyperglycemia in these patients.     

Systemic and intracerebroventricular injections of vasotocin inhibit appetitive and consummatory components of male sexual behavior in Japanese quail.

The authors investigated the behavioral actions of vasotocin (VT) in castrated testosterone-treated male Japanese quail. The appetitive and consummatory components of sexual behavior as well as the occurrence frequency of crows were inhibited, in a dose-dependent manner, by injections of VT. The authors observed opposite effects after injection of the V1 receptor antagonist, dPTyr(Me)AVP. Lower doses of VT were more active after central than after systemic injection, and effects of systemic injections of VT were blocked by a central injection of dPTyr(Me)AVP. The behavioral inhibition was associated with a modified diuresis after systemic but not central injection. These results provide direct evidence that VT affects male sexual behavior in quail by a direct action on the brain independent of its peripheral action on diuresis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

FHUQI-Miner: Fast high utility quantitative itemset mining

Applied Intelligence - High utility itemset mining is a popular pattern mining task, which aims at revealing all sets of items that yield a high profit in a transaction database. Although this task...     

Identifying the criterion spontaneously minimized during the take-off phase of a sub-maximal long jump through optimal synthesis

Optimal synthesis of human movement or the prediction of the kinematics of a new movement require not only that the multi-body system be modeled but also that a performance criterion is specified. For sub-maximal movements the selection of a suitable performance criterion, able to generate realistic dynamic behavior is difficult. A two-dimensional simulation model of the take-off phase of a sub-maximal long jump was developed to study the effect of criterion choice on the realism of simulated movements. A parametric optimization technique was employed to obtain solutions to the constrained equations of motion. Seven different criteria were evaluated, by comparing simulated movements with an actual performance, to identify the criterion which most closely approximated that spontaneously minimized by the athlete. Synthesis of the take-off phase of a sub-maximal long jump was found to be sensitive to the chosen criterion, with a criterion based on minimizing joint intersegmental forces found to perform well.     

A Model of Weekly Labor Participation for a Belgian Synthetic Population

This paper presents a model of labor participation calibrated on a weekly basis; part-time and full-time employments are also considered. By applying the theory of random utility maximization we model households’ choices. In order to have a good temporal and spatial coverage the model is calibrated on three datasets, extracted from both national and regional travel surveys. The results are applied to synthetic households that reproduce the Belgian population. The proposed innovative methodology simulates synthetic agents by accounting both for households’ and individuals’ characteristics, while not suffering from the problem of the “zero cell value”. The results indicate that there is major day-to-day variability in working activity participation; in particular, on Wednesdays and Fridays the number of households working part-time or not working is particularly high. This is consistent with what was expected by the analysts. Working participation is a fundamental component in activity based models where work is considered a skeletal activity. The tools developed here can be useful to study how changes in population characteristics (i.e. increases of flexible working arrangements and of the number of women in the work force) affect activity participation and travel patterns.     

Simple and low-cost fabrication of PDMS microfluidic round channels by surface-wetting parameters optimization

Convenient for both biologists and MEMS designers, Polydimethylsiloxane (PDMS) polymer is intensively investigated for its biocompatibility, transparency, high resistance under plasma treatment, flexibility and resistance to high temperature. However, for microfluidic applications, the fabrication of PDMS circular channels is difficult to achieve except by wire moulding. In this article, we present a simple, fast and low-cost fabrication method which can be applied out of clean-room environment. It is based on the deposition of alginic acid sodium salt aqueous solution, enabling the formation of a liquid cylinder on the most hydrophilic part of a hydrophilic/hydrophobic patterned surface. We experimentally studied the interaction between liquid rivulets and surfaces presenting a contrast of wettability and/or a stepwise texture. Subsequent moulding of the half-cylinder of liquid produces round PDMS microfluidic channels. The optimal parameters for hydrophilic/hydrophobic patterns have then been applied to produce the roundest possible channels. The realisation of both straight channels 300–500 μm wide, 1 cm long and 75° tangent chord angle at best, and Y-shaped channels with the same dimensions and 55° TCA is demonstrated.     

Strong accumulators from collision-resistant hashing

Accumulator schemes were introduced in order to represent a large set of values as one short value called the accumulator. These schemes allow one to generate membership proofs, that is, short witnesses that a certain value belongs to the set. In universal accumulator schemes, efficient proofs of non-membership can also be created. Li et?al. (Proceedings of applied cryptography and network security—ACNS ’07, LNCS, vol 4521, 2007), building on the work of Camenisch and Lysyanskaya (Advances in cryptology—proceedings of Crypto ’02, LNCS, vol 2442. Springer, Berlin, pp 61–76, 2002), proposed an efficient accumulator scheme, which relies on a trusted accumulator manager. Specifically, a manager that correctly performs accumulator updates. In this work, we introduce the notion of strong universal accumulator schemes, which are similar in functionality to universal accumulator schemes, but do not assume the accumulator manager is trusted. We also formalize the security requirements for such schemes. We then give a simple construction of a strong universal accumulator scheme, which is provably secure under the assumption that collision-resistant hash functions exist. The weaker requirement on the accumulator manager comes at a price; our scheme is less efficient than known universal accumulator schemes—the size of (non)membership witnesses is logarithmic in the size of the accumulated set in contrast to constant in the scheme of Camenisch and Lysyanskaya. Finally, we show how to use strong universal accumulators to solve a problem of practical relevance, the so-called e-Invoice Factoring Problem.     

The Esterase PfeE,the Achilles’ Heel in the Battle for Iron between Pseudomonas aeruginosa and Escherichia coli

Bacteria access iron, a key nutrient, by producing siderophores or using siderophores produced by other microorganisms. The pathogen Pseudomonas aeruginosa produces two siderophores but is also able to pirate enterobactin (ENT), the siderophore produced by Escherichia coli. ENT-Fe complexes are imported across the outer membrane of P. aeruginosa by the two outer membrane transporters PfeA and PirA. Iron is released from ENT in the P. aeruginosa periplasm by hydrolysis of ENT by the esterase PfeE. We show here that pfeE gene deletion renders P. aeruginosa unable to grow in the presence of ENT because it is unable to access iron via this siderophore. Two-species co-cultures under iron-restricted conditions show that P. aeruginosa strongly represses the growth of E. coli as long it is able to produce its own siderophores. Both strains are present in similar proportions in the culture as long as the siderophore-deficient P. aeruginosa strain is able to use ENT produced by E. coli to access iron. If pfeE is deleted, E. coli has the upper hand in the culture and P. aeruginosa growth is repressed. Overall, these data show that PfeE is the Achilles’ heel of P. aeruginosa in communities with bacteria producing ENT.