The polymerisation of 2-furyl vinyl ketone

Summary 2-Furyl vinyl ketone was polymerised using anionic, cationic and free-radical initiators. Yields and molecular weights varied with the type of activation. Whereas radical polymerisation gave a product possessing a regular vinylic structure, other kinds of units were detected in the polymers prepared with anionic and cationic catalysts.     

Visually guided locomotion, distractibility, and the missing-stimulus effect in hooded rats with unilateral or bilateral lesions of parietal cortex.

When hooded rats with bilateral lesions of Krieg's Area 7 (parietal cortex) were trained to locomote toward visual targets in a runway, they ran less accurately than did controls, although unilaterals ran accurately. When flashing lights were presented unexpectedly during their run, bilateral parietals were less disrupted than were controls, but they failed to show total neglect. Unilateral parietals turned toward distracters on either side but turned preferentially toward distracters contralateral to the intact hemisphere, particularly when distracters occurred bilaterally and simultaneously. Effects due to the omission of expected distracters were similar in parietals and controls. Rat parietal cortex is not essential for the redirection of attention to stimuli notable for their unexpected presence or absence, but parietal cortex may resolve interhemispheric competition. Results suggest a homology between parietal cortex in rat and primate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interactive frames constructed in Second Life meetings: a study in educational and professional settings

Based on the analysis of “real” Second Life meetings data, in educational and professional settings, our objective is to understand the actual uses of this kind of Virtual World and more particularly, the interactive frames constructed in SL meetings and their interrelation with uses of communication media. The originality of our analytical framework stems from the combination of two perspectives: a third view perspective based on analyses of observational data and a first view perspective based on users’ reports on their experience in SL. Our results highlight: boundaries between serious and recreational registers; avatar’s expression and attribution of feelings to the person “behind”; spatial positioning as indicators and constructors of roles and engagement; management of communication fluidity and joint focus; narrowing of communication media used for task focus content; emerging mediation role for management of fractured exchanges.     

Source/Filter Model for Unsupervised Main Melody Extraction From Polyphonic Audio Signals

Extracting the main melody from a polyphonic music recording seems natural even to untrained human listeners. To a certain extent it is related to the concept of source separation, with the human ability of focusing on a specific source in order to extract relevant information. In this paper, we propose a new approach for the estimation and extraction of the main melody (and in particular the leading vocal part) from polyphonic audio signals. To that aim, we propose a new signal model where the leading vocal part is explicitly represented by a specific source/filter model. The proposed representation is investigated in the framework of two statistical models: a Gaussian Scaled Mixture Model (GSMM) and an extended Instantaneous Mixture Model (IMM). For both models, the estimation of the different parameters is done within a maximum-likelihood framework adapted from single-channel source separation techniques. The desired sequence of fundamental frequencies is then inferred from the estimated parameters. The results obtained in a recent evaluation campaign (MIREX08) show that the proposed approaches are very promising and reach state-of-the-art performances on all test sets.      

Scheduling loops with partial loop-carried dependencies

This paper deals with task scheduling, where each task is one particular iteration of a DO loop with partial loop-carried dependencies. Independent iterations of such loops can be scheduled in an order different from the one of classical serial execution, so as to increase program performance.The approach that we present is based both on the use of a directive added to the High Performance Fortran (HPF2) language, which specifies the dependencies between iterations, and on inspector/executor support, implemented in the CoLUMBO library, which builds the task graph and schedules tasks associated with iterations. We validate our approach by showing results achieved on an IBM SP2 for a sparse Cholesky factorization algorithm applied to real problems.     

Identification and Molecular Cloning of Putative Odorant-Binding Proteins from the American Palm Weevil, Rhynchophorus palmarum L.

We have identified and cloned the cDNAs encoding two odorant-binding proteins (OBPs) from the American palm weevil (APW) Rhynchophorus palmarum (Coleoptera, Curculionidae). Degenerate primers were designed from the N-terminal sequences and were used in polymerase chain reaction (PCR) in order to obtain full-length sequences in both males and females. In both sexes, two different cDNAs were obtained, encoding 123 and 115 amino acid-deduced sequences. Each sequence showed few amino acid differences between the sexes. The proteins were named RpalOBP2 and RpalOBP4 for male, RpalOBP2' and RpalOBP4' for female, with the types 2 and 4 presenting only 34% identities. These proteins shared high identity with previously described coleopteran OBPs. In native gels, RpalOBP2 clearly separated into two bands and RpalOBP4 into three bands, suggesting the presence of several conformational isomers. Thus, OBP diversity in this species may rely on both the presence of OBPs from different classes and the occurrence of isoforms for each OBP.     

Grafting RGD containing peptides onto hydroxyapatite to promote osteoblastic cells adhesion

Ceramics possess osteoconductive properties but exhibit no intrinsic osteoinductive capacity. Consequently, they are unable to induce new bone formation in extra osseous sites. In order to develop bone substitutes with osteogenic properties, one promising approach consists of creating hybrid materials by associating in vitro biomaterials with osteoprogenitor cells. With this aim, we have developed a novel strategy of biomimetic modification to enhance osseointegration of hydroxyapatite (HA) implants. RGD-containing peptides displaying different conformations (linear GRGDSPC and cyclo-DfKRG) were grafted onto HA surface by means of a three-step reaction procedure: silanisation with APTES, cross-linking with N-succinimidyl-3-maleimidopropionate and finally immobilisation of peptides thanks to thiol bonding. Whole process was performed in anhydrous conditions to ensure the reproducibility of the chemical functionalisation. The three-step reaction procedure was characterised by high resolution X-ray photoelectron spectroscopy. Efficiency of this biomimetic modification was finally demonstrated by measuring the adhesion of osteoprogenitor cells isolated from HBMSC onto HA surface.     

Application of probabilistic and fuzzy cognitive approaches in semantic web framework for medical decision support

This study aimed to focus on medical knowledge representation and reasoning using the probabilistic and fuzzy influence processes, implemented in the semantic web, for decision support tasks. Bayesian belief networks (BBNs) and fuzzy cognitive maps (FCMs), as dynamic influence graphs, were applied to handle the task of medical knowledge formalization for decision support. In order to perform reasoning on these knowledge models, a general purpose reasoning engine, EYE, with the necessary plug-ins was developed in the semantic web. The two formal approaches constitute the proposed decision support system (DSS) aiming to recognize the appropriate guidelines of a medical problem, and to propose easily understandable course of actions to guide the practitioners. The urinary tract infection (UTI) problem was selected as the proof-of-concept example to examine the proposed formalization techniques implemented in the semantic web. The medical guidelines for UTI treatment were formalized into BBN and FCM knowledge models. To assess the formal models’ performance, 55 patient cases were extracted from a database and analyzed. The results showed that the suggested approaches formalized medical knowledge efficiently in the semantic web, and gave a front-end decision on antibiotics’ suggestion for UTI.     

Ripening conditions: A tool for the control of Listeria monocytogenes in uncooked pressed type cheese

The effect of ripening conditions (two temperatures, 9 °C and 13 °C, and two relative humidities 93% and 97%) on the growth of Listeria monocytogenes and other microbial populations was evaluated in the cores and rinds of uncooked pressed type cheeses prepared with pasteurised milk and inoculated either with Streptococcus thermophilus only or with an anti-listerial consortium. Regardless of temperature and relative humidity (RH), inhibition by the anti-listerial consortium was stronger in the cheese cores than in the rinds. Temperature had no significant effect on L. monocytogenes counts in cores or rinds. However, at the beginning of ripening in the consortium cheese, L. monocytogenes growth was more strongly inhibited at 13 °C than at 9 °C. Regardless of inoculation type and ripening temperature, counts of L. monocytogenes were significantly lower in the cores and rinds of cheeses ripened at 93% than at 97% RH. Lactobacilli counts were higher at 13 °C than at 9 °C and at 93% than at 97% RH. Lactobacilli can help to inhibit L. monocytogenes by catabolising galactose and producing lactate. Further investigations will be needed to evaluate the effect of ripening at 13 °C and 93% RH on the sensorial properties of cheese.     

Modulation of Lumen Formation by Microgeometrical Bioactive Cues and Migration Mode of Actin Machinery

How endothelial cells (ECs) express the particular filopodial or lamellipodial form of the actin machinery is critical to understanding EC functions such as angiogenesis and sprouting. It is not known how these mechanisms coordinately promote lumen formation of ECs. Here, adhesion molecules (RGD peptides) and inductor molecules (BMP‐2 mimetic peptides) are micropatterned onto polymer surfaces by a photolithographic technique to induce filopodial and lamellipodial migration modes. Firstly, the effects of peptide microgeometrical distribution on EC adhesion, orientation and morphogenesis are evaluated. Large micropatterns (100 μm) promote EC orientation without lumen formation, whereas small micropatterns (10–50 μm) elicit a collective cell organization and induce EC lumen formation, in the case of RGD peptides. Secondly, the correlation between EC actin machinery expression and EC self‐assembly into lumen formation is addressed. Only the filopodial migration mode (mimicked by RGD) but not lamellipodial migration mode (mimicked by BMP‐2) promotes EC lumen formation. This work gives a new concept for the design of biomaterials for tissue engineering and may provide new insight for angiogenesis inhibition on tumors.