Remote sensing of the energy of auroral electrons in Saturn’s atmosphere: Hubble and Cassini spectral observations

in Icarus (2013), 223

Saturn’s north ultraviolet aurora has been successfully observed twice between March and May 2011 with the STIS long-slit spectrograph on board the Hubble Space Telescope. Spatially resolved spectra at ... [more ▼]

Saturn’s north ultraviolet aurora has been successfully observed twice between March and May 2011 with the STIS long-slit spectrograph on board the Hubble Space Telescope. Spatially resolved spectra at ∼12 Å spectral resolution have been collected at different local times from dawn to dusk to determine the amount of hydrocarbon absorption. For this purpose, the HST telescope slewed across the auroral oval from mid-latitudes up to beyond the limb while collecting spectral data in the timetag mode. Spectral images of the north ultraviolet aurora were obtained within minutes and hours with the UVIS spectrograph on board Cassini. Several daytime sectors and one nightside location were observed and showed signatures of weak absorption by methane present in (or above) the layer of the auroral emission. No absorption from other hydrocarbons (e.g. C2H2) has been detected. For the absorbed spectra, the overlying slant CH4 column varies from 3x1015 to 2x1016 cm-2, but no clear dependence on local time is identified. A Monte Carlo electron transport model is used to calculate the vertical distribution of the H2 emission and to relate the observed spectra to the energy of the primary auroral electrons. Assuming electron precipitation with a Maxwellian energy distribution into a standard model atmosphere, we find that the mean energy ranges from less than 3 to ∼10 keV. These results are compared with previous determinations of the energy of Saturn’s aurora based on ultraviolet spectra and limb images. We conclude that the energies derived from spectral methods indicate a wide range of electron energies while the nightside limb images suggest that the auroral precipitation is consistently soft. We emphasize the need for more realistic model atmospheres with temperature and hydrocarbon distributions appropriate to high-latitude conditions. [less ▲]

A full-discontinuous Galerkin formulation of non-linear Kirchhoff-Love shells: elasto-plastic finite deformations, parallel computation & fracture applications

in International Journal for Numerical Methods in Engineering (2013), 93(1), 80-117

Due to its ability to take into account discontinuities, the discontinuous Galerkin (DG) method presents some advantages for modeling crack initiations and propagations. This concept has been recently ... [more ▼]

Due to its ability to take into account discontinuities, the discontinuous Galerkin (DG) method presents some advantages for modeling crack initiations and propagations. This concept has been recently applied to 3D simulations and to elastic thin bodies. In this last case, the assumption of small elastic deformations before crack initiations or propagations reduces drastically the applicability of the framework to a reduced number of materials. To remove this limitation, a full-DG formulation of non-linear Kirchhoff-Love shells is presented and is used in combination with an elasto-plastic finite deformations model. The results obtained by this new formulation are in agreement with other continuum elasto-plastic shell formulations. Then this full-DG formulation of Kirchhoff-Love shells is coupled with the cohesive zone model to perform thin body fracture simulations. As this method allows considering elasto-plastic constitutive laws in combination with the cohesive model, accurate results compared to the experiments are found. In particular, the crack path and propagation rate of a blasted cylinder are shown to match experimental results. One of the main advantages of this framework is its ability to run in parallel with a high speed-up factor, allowing the simulation of ultra fine meshes. [less ▲]

Pour et contre le Parnasse. De Gautier aux symbolistes

in Nouvelle Revue Pédagogique (NRP Lycée) (2013), n° 53

La question des querelles en littérature a, au cours des dernières années, suscité un intérêt certain, ce dont témoigne le regain de publications relatives au sujet. Encore faut-il constater que cette ... [more ▼]

La question des querelles en littérature a, au cours des dernières années, suscité un intérêt certain, ce dont témoigne le regain de publications relatives au sujet. Encore faut-il constater que cette problématique semble parfois se suffire à elle-même et que sa dimension plaisante agrémente des études littéraires quelquefois tenues pour revêches. Pourtant, sans minimiser la valeur divertissante de l’anecdote, on ne saurait assez souligner l’importance effective des mouvements d’opposition, des fractures et autres dissensions qui dynamisent la vie littéraire autant qu’elles en définissent les conditions à une époque donnée, modifiant en cela les manières d’être, d’agir et de penser des individus évoluant dans cet univers. Il demeure, au sujet de ces querelles littéraires, de nombreuses enquêtes à mener, qui tiennent autant à leur rôle socialisateur, créatif et dynamisant, qu’aux formes dans lesquelles elles prennent corps, aux raisons qui les motivent, aux articulations qu’elles permettent entre l’individuel et le collectif, voire aux ressources rhétoriques qui les sous-tendent, dans les œuvres ou dans les discours parallèles accompagnant celles-ci. Pour illustrer la façon dont ce questionnement peut s’élaborer, nous proposons ici un parcours en amont et en aval de la nébuleuse parnassienne, dont l’origine se trouve au mitan du XIXe siècle. Les revendications esthétiques afférentes ont engagé diverses formes de querelles qui, de la préface à l’œuvre, offrent l’occasion d’examiner autant les vecteurs et les supports de ces positionnements, que les dynamiques de concorde qu’ils impliquent, avec et contre eux. [less ▲]

Measuring poverty without the Mortality Paradox

in Social Choice and Welfare (2013), 40(1), 285-316

Under income-differentiated mortality, poverty measures reflect not only the “true” poverty, but, also, the interferences or noise caused by the survival process at work. Such interferences lead to the ... [more ▼]

Under income-differentiated mortality, poverty measures reflect not only the “true” poverty, but, also, the interferences or noise caused by the survival process at work. Such interferences lead to the Mortality Paradox: the worse the survival conditions of the poor are, the lower the measured poverty is. We examine several solutions to avoid that paradox. We identify conditions under which the extension, by means of a fictitious income, of lifetime income profiles of the prematurely dead neutralizes the noise due to differential mortality. Then, to account not only for the “missing” poor, but, also, for the “hidden” poverty (premature death), we use, as a fictitious income, the welfare-neutral income, making indifferent between life continuation and death. The robustness of poverty measures to the extension technique is illustrated with regional Belgian data. [less ▲]

Decommissioned dates: chemical composition and fermentation substrate for the production of extracellular catalase by an Aspergillus phoenicis mutant

in Agriculture and Biology Journal of North America (2013)

The recovery of dates downgraded as a fermentation medium for the production of extracellular catalase by Aspergillus phoenicis K30 was studied. Analysis of the chemical composition of pulp and kernel ... [more ▼]

The recovery of dates downgraded as a fermentation medium for the production of extracellular catalase by Aspergillus phoenicis K30 was studied. Analysis of the chemical composition of pulp and kernel flour of dates showed that the pulp had a considerably greater carbohydrate content compared to the kernel (84 vs 2.93% respectively). However, the kernel flour was richer in nitrogen (0.68% vs 0.34), mineral elements (3.63 vs 1.28%) and in essential fatty acids C18: 2 vs C18: 3 than the pulp flour. The soluble extract of the date flour showed that sugars solubilised at 90% consisted of sucrose, fructose and glucose. Therefore, this extract, being an important source of carbon and energy, was used in the current study as a fermentation medium (after supplementation with 20% of corn steep) for the production of extracellular catalase by A. Phoenicis K30. During the course of this fermentation, the biomass was estimated at 18.6 g / L after 72 h of culture, while the maximum concentration of extracellular catalase (47.5 U / ml) was reached at 96 h of fermentation. The mycelium obtained in pellet form is suitable for industrial exploitation of this process. [less ▲]

Validation of fatty acid predictions in milk using mid-infrared spectrometry across cattle breeds.

in Animal (2013), 7

GES-18, a new carbapenem-hydrolyzing GES-Type β-lactamase from pseudomonas aeruginosa that contains Ile80 and Ser170 residues.

in Antimicrobial Agents and Chemotherapy (2013), 57(1)

A clinical isolate of Pseudomonas aeruginosa recovered from the lower respiratory tract of an 81-year-old patient hospitalized in Belgium was sent to the national reference center to determine its ... [more ▼]

A clinical isolate of Pseudomonas aeruginosa recovered from the lower respiratory tract of an 81-year-old patient hospitalized in Belgium was sent to the national reference center to determine its resistance mechanism. PCR sequencing identified a new GES variant, GES-18, which differs from the carbapenem-hydrolyzing enzyme GES-5 by a single amino acid substitution (Val80Ile, in the numbering according to Ambler) and from GES-1 by two substitutions (Val80Ile and Gly170Ser). Detailed kinetic characterization showed that GES-18 and GES-5 hydrolyze imipenem and cefoxitin with similar kinetic parameters and that GES-18 was less susceptible than GES-1 to classical β-lactamase inhibitors such as clavulanate and tazobactam. The overall structure of GES-18 is similar to the solved structures of GES-1 and GES-2, the Val80Ile and Gly170Ser substitutions causing only subtle local rearrangements. Notably, the hydrolytic water molecule and the Glu166 residue were slightly displaced compared to their counterparts in GES-1. Our kinetic and crystallographic data for GES-18 highlight the pivotal role of the Gly170Ser substitution which distinguishes GES-5 and GES-18 from GES-1. [less ▲]

Nerf spinal accessoire

in Lettre du Neurologue (La) : le Courrier du Spécialiste (2013), XVII(1), 16-20

Identification and typing of Salmonella serotypes isolated from guinea fowl (Numida meleagris) farms in Benin during four laying seasons (2007-2010)

in Avian Pathology : Journal of the W.V.P.A (2013), 42

Chemical Ecology of the Colorado Potato Beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), and Potential for Alternative Control Methods

in Insects (2013), 4(1), 31-54

The Colorado potato beetle (CPB) has been a major insect pest to potato farming for over 150 years and various control methods have been established to reduce its impact on potato fields. Crop rotation ... [more ▼]

The Colorado potato beetle (CPB) has been a major insect pest to potato farming for over 150 years and various control methods have been established to reduce its impact on potato fields. Crop rotation and pesticide use are currently the most widely used approaches, although alternative methods are being developed. Here we review the role of various volatile and nonvolatile chemicals involved in behavior changes of CPB that may have potential for their control. First, we describe all volatile and nonvolatile chemicals involved in host plant localization and acceptance by CPB beetles, including glycoalcaloids and host plant volatiles used as kairomones. In the second section, we present the chemical signals used by CPB in intraspecific communication, including sex and aggregation pheromones. Some of these chemicals are used by natural enemies of CPBs to locate their prey and are presented in the third section. The last section of this review is devoted a discussion of the potential of some natural chemicals in biological control of CPB and to approaches that already reached efficient field applications. [less ▲]

The dual role of weather forecasts on changes in activity-travel behavior

in Journal of Transport Geography (2013), 28

A deeper understanding of how human activity-travel behavior is affected by various weather conditions is essential for both policy makers and traffic managers. To unravel the ambiguity in findings ... [more ▼]

A deeper understanding of how human activity-travel behavior is affected by various weather conditions is essential for both policy makers and traffic managers. To unravel the ambiguity in findings reported in the literature, the main objective of this paper is to obtain an accurate assessment of how weather forecasts trigger changes in Flemish activity-travel behavior. To this end, data were collected by means of a stated adaptation experiment, which was administered both on the Internet and via traditional paper-and-pencil questionnaires. To address the main research question of this paper, two statistical techniques were adopted. The first technique is the computation of Pearson chi-square independence tests. The second approach is the estimation of a GEE-MNL-model. The results from both techniques underscore the dual role of weather forecasts on changes in activity-travel behavior. On the one hand, the results clearly illustrate the significant effect of forecasted weather; the likelihood of changes in activity-travel behavior significantly depends on the weather forecasted. On the other hand, different methods of acquiring weather information (exposure, media source, or perceived reliability) do not impact the probability of behavioral adaptations. This duality may be partially attributable to the discrepancy that exists between weather forecasts and true traffic and roadway conditions. Therefore, the implementation of a road weather information system that is directly linked to the weather forecasts is recommended. [less ▲]

Ethique et conflits d'intérêts en droit européen de la concurrence

in Concurrences : Revue des Droits de la Concurrence (2013), (1),

The debate over the compatibility of EU competition enforcement with Article 6 ECHR is far from over. Whilst there has been a great - some would say excessive - deal of papers on due process issues, less ... [more ▼]

The debate over the compatibility of EU competition enforcement with Article 6 ECHR is far from over. Whilst there has been a great - some would say excessive - deal of papers on due process issues, less, if none attention has been paid to the rules and remedies that govern conflicts of interests amongst lawyers, civil servants, legal secretaries and Members of the Court. This short paper seeks to open the discussion on this issue. [less ▲]

Experiments with the interior-point method for solving large scale Optimal Power Flow problems

in Electric Power Systems Research (2013), 95

This paper reports extensive results obtained with the interior-point method (IPM) for nonlinear programmes (NLPs) stemming from large-scale and severely constrained classical Optimal Power Flow (OPF) and ... [more ▼]

This paper reports extensive results obtained with the interior-point method (IPM) for nonlinear programmes (NLPs) stemming from large-scale and severely constrained classical Optimal Power Flow (OPF) and Security-Constrained Optimal Power Flow (SCOPF) problems. The paper discusses transparently the problems encountered such as convergence reliability and speed issues of the method. [less ▲]

Stockage de carbone et flux de gaz à effet de serre en prairie (synthèse bibliographique)

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(1), 103-117

Grassland carbon (C) sequestration can play an important role in mitigating total greenhouse gas (GHG) emissions of livestock production systems. An accurate inventory of livestock production system ... [more ▼]

Grassland carbon (C) sequestration can play an important role in mitigating total greenhouse gas (GHG) emissions of livestock production systems. An accurate inventory of livestock production system contribution to GHG emissions requires to think in terms of global budget, by considering both the GHG sources and the mitigation potential trough grassland soil carbon sequestration. There is a huge variability in C and GHG balances of grasslands that is mainly due to management practices and climatic conditions. The present article shows that, to reduce the uncertainties of the results, long term measurements at the field scale are necessary. Also, it shows the importance of taking the fluxes of the three main GHGs (carbon dioxide, nitrous oxide, methane) into account when calculating the GHG budget. This article also highlights the need for a better understanding of the mechanisms driving the fluxes, in relation to environmental factors and management practices, in order to propose mitigation strategies able to enhance soil carbon sequestration in soils and to reduce methane and nitrous oxide emissions. [less ▲]

Fibromyalgie: un syndrome d'Ehlers-Danlos de type hypermobile qui s'ignore?

in Revue Médicale de Liège (2013), 68(1), 22-4

Some patients suffering from fibromyalgia present with clinical signs and alterations in the histopathology, immunohistochemistry and ultrastructure of the dermis similar to the Ehlers-Danlos syndrome ... [more ▼]

Some patients suffering from fibromyalgia present with clinical signs and alterations in the histopathology, immunohistochemistry and ultrastructure of the dermis similar to the Ehlers-Danlos syndrome, hypermobile type (EDSH). Some types of fibromyalgia possibly represent an undiagnosed EDSH. [less ▲]

Novel cooperation between CX3CL1 and CCL26 inducing NK cell chemotaxis via CX3CR1: a possible mechanism for NK cell infiltration of the allergic nasal tissue.

in Clinical & Experimental Allergy : Journal of the British Society for Allergy & Clinical Immunology (2013), 43(3), 322-31

BACKGROUND: Recent data indicated that natural killer (NK) cells and chemokines could play a pivotal role in nasal inflammation. CX3CR1, the only receptor for fractalkine/CX3CL1, is abundantly expressed ... [more ▼]

BACKGROUND: Recent data indicated that natural killer (NK) cells and chemokines could play a pivotal role in nasal inflammation. CX3CR1, the only receptor for fractalkine/CX3CL1, is abundantly expressed by NK cells, and was recently shown to also be a receptor for eotaxin-3/CCL26. However, no reports explored the NK cells-CX3CL1-CCL26 axis via CX3CR1 in allergy. OBJECTIVE: Our goals were first to determine specifically NK cell recruitment pattern in nasal tissue of allergic chronic rhinosinusitis (ACRS) and non-allergic chronic rhinosinusitis (NACRS) patients in comparison with healthy controls, and secondly, to investigate the function of CX3CR1 in NK cell migration. METHODS: Immunohistochemistry, microchemotaxis chambers, flow cytometry and confocal microscopy were used in this study. RESULTS: Herein, we showed that NK cells infiltrated the epithelial layers of nasal tissue only in ACRS patients and not in NACRS patients or controls. NK cells were also more numerous in the stroma of the nasal tissue from ACRS patients compared with NACRS patients or controls. This migration could be mediated by both CX3CL1 and CCL26, as these two chemokines induced NK cell migration. Moreover, both molecules also stimulated cytoskeleton changes and F-actin reorganisation in NK cells. Chemotaxis and cytoskeleton changes were sensitive to genistein, a tyrosine kinase inhibitor. By flow cytometry, we demonstrated that a single antigen nasal provocation challenge increased the expression of CX3CR1 on NK cells in allergic rhinitis (AR) patients. The function of this receptor was associated with a significant augmentation of NK cell chemotaxis against the optimal doses of CX3CL1 and CCL26. CONCLUSIONS AND CLINICAL RELEVANCE: Our results highlight a novel role for CX3CR1 in NK cell migration that may contribute to the NK cell trafficking to the allergic upper airway. This could be mediated largely by CX3CL1 and CCL26 stimulation of the tyrosine kinase pathway. [less ▲]

Fast microwave assisted extraction of rotenone for its quantification in seeds of yam bean (Pachyrhizus sp.)

in Journal of Separation Science (2013), 36

The aim of this study was to find if fast microwave assisted extraction could be an alternative to the conventional soxhlet extraction for the quantification of rotenone in yam bean seeds by solid phase ... [more ▼]

The aim of this study was to find if fast microwave assisted extraction could be an alternative to the conventional soxhlet extraction for the quantification of rotenone in yam bean seeds by solid phase extraction and HPLC-UV. For this purpose, an experimental design was used to determine the optimal conditions of the microwave extraction. Then the values of the quantification on three accessions from two different species of yam bean seeds were compared using the two different kinds of extraction. A microwave extraction of 11 min at 55°C using methanol/dichloromethane (50:50) allowed rotenone extraction either equivalently or more efficiently than the 8h soxhlet extraction method and was less sensitive to moisture content. The selectivity, precision, trueness, accuracy and limit of quantification of themethod with microwave extraction were also demonstrated. [less ▲]

Video multitracking of fish behaviour: a review and future perspectives

in Fish & Fisheries (2013), 14(2), 186-204

With the development of digital imaging techniques over the last decade, there are now new opportunities to study complex behavioural patterns in fish (e.g. schooling behaviour) and to track a very large ... [more ▼]

With the development of digital imaging techniques over the last decade, there are now new opportunities to study complex behavioural patterns in fish (e.g. schooling behaviour) and to track a very large number of individuals. These new technologies and methods provide valuable information to fundamental and applied science disciplines such as ethology, animal sociology, animal psychology, veterinary sciences, animal welfare sciences, statistical physics, pharmacology, as well as neuro- and ecotoxicology. This paper presents a review of fish video multitracking techniques. It describes the possibilities of tracking individuals and groups at different scales, but also outlines the advantages and limitations of the detection methods. The problem of occlusions, during which errors of individual identifications are very frequent, is underlined. This paper summarises different approaches to improving the quality of individual identification, notably by the development of three-dimensional tracking, image analysis and probabilistic applications. Finally, implications for fish research and future directions are presented. [less ▲]

Recommendations for the repair, the lining or the strengthening of concrete slabs or pavements with bonded cement-based material overlays

in Materials and Structures (2013), 46

The recommendations presented in this publication are inspired by the State of the Art Report edited by the RILEM technical committee TC 193 RLS Bonded cement-based material overlays for the repair, the ... [more ▼]

The recommendations presented in this publication are inspired by the State of the Art Report edited by the RILEM technical committee TC 193 RLS Bonded cement-based material overlays for the repair, the lining or the strengthening of slabs and pavements. The objective is to lay out all the practical aspects to be considered in the design of concrete overlays: bonded concrete overlay process, assessment of the existing structure, surface preparation, overlay materials, design methods, construction procedure and quality control/assurance (QC/QA) system, and maintenance. [less ▲]

Etude histologique des embryons avortés lors des croisements entre Phaseolus vulgaris L. et Phaseolus coccineus L.

in International Journal of Biological and Chemical Sciences (2013)

Mechanobiological modeling can explain orthodontic tooth movement: three case studies.

in Journal of Biomechanics (2013), 46(3), 470-7

Progress in medicine and higher expectation of quality of life has led to a higher demand for several dental and medical treatments. This increases the occurrence of situations in which orthodontic ... [more ▼]

Progress in medicine and higher expectation of quality of life has led to a higher demand for several dental and medical treatments. This increases the occurrence of situations in which orthodontic treatment is complicated by pathological conditions, medical therapies and drugs. Together with experiments, computer models might lead to a better understanding of the effect of pathologies and medical treatment on tooth movement. This study uses a previously presented mechanobiological model of orthodontic tooth displacement to investigate the effect of pathologies and (medical) therapies on the result of orthodontic treatment by means of three clinically relevant case studies looking at the effect of estrogen deficiency, the effect of OPG injections and the influence of fluoride intake. When less estrogen was available, the model predicted bone loss and a rise in the number of osteoclasts present at the compression side, and a faster bone resorption. These effects were also observed experimentally. Experiments disagreed on the effect of estrogen deficiency on bone formation, while the mechanobiological model predicted very little difference between the pathological and the non-pathological case at formation sites. The model predicted a decrease in tooth movement after OPG injections or fluoride intake, which was also observed in experiments. Although more experiments and model analysis is needed to quantitatively validate the mechanobiological model used in this study, its ability to conceptually describe several pathological conditions is an important measure for its validity. [less ▲]

Behavior in the open field predicts the number of KCl-induced cortical spreading depressions in rats.

in Behavioural Brain Research (2013), 236(1), 90-3

Anxiety disorders are known to be comorbid with migraine, and cortical spreading depression (CSD) is the most likely cause of the migraine aura. To search for possible correlations between susceptibility ... [more ▼]

Anxiety disorders are known to be comorbid with migraine, and cortical spreading depression (CSD) is the most likely cause of the migraine aura. To search for possible correlations between susceptibility to CSD and anxiety we used the open field test in male Sprague-Dawley rats chronically treated with the preventive anti-migraine drugs valproate or riboflavin. Animals avoiding the central area of the open field chamber and those with less exploratory activity (i.e. rearing) were considered more anxious. After 4 weeks of treatment CSDs were elicited by application of 1M KCl over the occipital cortex and the number of CSDs occurring over a 2h period was compared to the previously assessed open field behavior. Higher anxiety-like behavior was significantly correlated with a higher frequency of KCl-induced CSDs. In saline-treated animals, fewer rearings were found in animals with more frequent CSDs (R=-1.00). The duration of ambulatory episodes in the open field center correlated negatively with number of CSDs in the valproate group (R=-0.83; p<0.005) and in riboflavin treated group (R=-0.69; p<0.05) as well as total time spent in the open field center in both groups (R=-0.75; p<0.05 and R=-0.58; p<0.1 respectively). These results suggest that anxiety symptoms are associated with susceptibility to CSD and might explain why it can be an aggravating factor in migraine with aura. [less ▲]

Genetic variability of the mid-infrared prediction of lactoferrin content in milk for Walloon Holstein first-parity cows

in Livestock Science (2013), 151(2-3), 158-162

The objective of this study was to assess the genetic variability of the mid-infrared prediction of lactoferrin content in milk (pLF) in Holstein first-parity cows. Variance components were estimated by ... [more ▼]

The objective of this study was to assess the genetic variability of the mid-infrared prediction of lactoferrin content in milk (pLF) in Holstein first-parity cows. Variance components were estimated by Average Information Restricted Maximum Likelihood using a single-trait test-day random regression animal model. The dataset included 395,287 test-day records from 67,178 cows in 1190 herds from the Walloon Region of Belgium. Average pLF was 164.89. mg/L and the standard deviation was 76.07. mg/L. Frequency distribution for pLF was slightly asymmetrical, and pLF seemed to increase almost linearly all along the first lactation after a sharp decrease in early lactation. Genetic variance of pLF increased with days in milk within lactation while the permanent environmental variance was the highest in early lactation, then decreased to become lower than genetic variance at 50 days in milk, and finally increased in the last lactation stages. The pLF was a moderately heritable trait. Daily heritability of pLF was the lowest at 5 days in milk (0.19), then increased to reach a maximum at 260 days in milk (0.44), and finally decreased for the last stages of lactation (0.35 at 365 days in milk). Results from this study indicated that pLF is variable and heritable over the lactation and therefore it could be changed by genetic selection. © 2012 Elsevier B.V. [less ▲]

Effect of breed, sex, age and body weight on Echocardiographic Measurements in the Equine Species

in Research in Veterinary Science (2013), In press

Little is known about the effect of various animal's signalment variables on echocardiographic reference values in the equine species. This study was performed to evaluate the effect of sex, breed, age ... [more ▼]

Little is known about the effect of various animal's signalment variables on echocardiographic reference values in the equine species. This study was performed to evaluate the effect of sex, breed, age and body weight (BW) on echocardiographic measurements in the equine species. Echocardiography was performed on 212 ponies or horses of various breeds, aged from 1 day to 37 years old (mean ± SD: 7.8 ± 5.8 years), BW 38-890 kg (mean ± SD: 421 ± 133 Kg), and free of cardiac disease. Fifty of those animals aged from 2 months to 35 years old (mean ± SD: 11.6 ± 6.4 years old); BW 77-662 kg (mean ± SD: 436 ± 135 kg) were also examined using the pulsed-wave Doppler mode. Standard two-dimensional and M-mode echocardiography were performed on all animals. Standard pulsed-wave Doppler examination of each cardiac valve was performed on the 50 first examined animals. Data were analysed using a general linear model including the effect of sex, age, breed and BW after logarithmic transformation of the data. Therefore, the same analysis was performed separately on animals aged  2 years-old and on older animals. All dimensional echocardiographic measurements were significantly affected by BW and most of them were significantly affected by breed, but not by sex. Only the aortic and the pulmonary artery internal diameter were significantly affected by age. None of the Doppler measurements were significantly affected by the tested variables. In conclusion, in the equine species, dimensional echocardiographic reference values should be established using regression equations as a function of BW, which could increase the diagnostic value of this leading technique in equine cardiology. Breed could also have an effect on those measurements. [less ▲]

The community of Hymenoptera parasitizing necrophagous Diptera in an urban biotope

in Journal of Insect Science [=JIS] (2013)

Most reports published in the field of forensic entomology are focused on Diptera and neglect the Hymenoptera community. However, Hymenoptera are part of the entomofaunal colonisation of a dead body. The ... [more ▼]

Most reports published in the field of forensic entomology are focused on Diptera and neglect the Hymenoptera community. However, Hymenoptera are part of the entomofaunal colonisation of a dead body. The use of Hymenoptera parasitoids in forensic entomology can be relevant to evaluate the time of death. Hymenoptera parasitoids of the larvae and pupae of flies may play an important role in the estimation of the post-mortem period, because their time of attack is often restricted to a small, well-defined windows of time in the development of the host insect. However, these parasitoids can interfere with the developmental times of colonising Diptera, and therefore a better understanding of their ecology is needed. The work reported here monitored the presence of adult Hymenoptera parasitoids on decaying pig carcasses in an urban biotope during the summer season (from May to September). Six families and six species were recorded in the field: Aspilota fuscicornis Haliday, Alysia manducator Panzer, Nasonia vitripennis Walker, Tachinaephagus zealandicus Ashmead, Trichopria sp., and Figites sp. In the laboratory, five species emerged from pupae collected in the field: Trichopria sp., Figites sp., A. manducator, N. vitripennis, and T. zealandicus. These five species colonise a broad spectrum of Diptera hosts, including those species associated with decomposing carcasses: Calliphoridae, Muscidae, Fanniidae, and Sarcophagidae [less ▲]

Ion-Mobility mass spectrometry as a potential tool to assign disulfide bonds arrangements in peptides with multiple disulfide bridges.

in Analytical Chemistry (2013)

Disulfide bridges play a major role in defining the structural properties of peptides and proteins. However, the determination of the cysteine pairing is still challenging. Peptide sequences are usually ... [more ▼]

Disulfide bridges play a major role in defining the structural properties of peptides and proteins. However, the determination of the cysteine pairing is still challenging. Peptide sequences are usually achieved using MS/MS spectra of the totally reduced unfolded species but the cysteine pairing information is lost. On the other hand, MS/MS experiments performed on native folded species show complex spectra composed of non-classical ions. MS/MS alone does not allow the cysteine pairing nor the full sequence of an unknown peptide to be determined. The major goal of this work is to set up a strategy for the full structural characterization of peptides including disulfide bridges annotation in the sequence. This strategy was developed by combining Ion Mobility Spectrometry (IMS)and Collision Induced Dissociation(CID). It is assumed that the opening of one S-S bridges in a peptide leads to a structural evolution which results in a modification of IMS drift time. In the presence of multiple S-S bridges, the shift in arrival time will depend on which disulfide(s) has (have) been reduced and on the shape adopted by the generated species. Due to specific fragmentations observed for each species, CID experiments performed after the mobility separation could provide not only information on peptide sequence, but also on the localization of the disulfide bridges. To achieve this goal, synthetic peptides containing two disulfides were studied. The openings of the bridges were carried out following different experimental conditions such as reduction, reduction/alkylation or oxidation. Due to disulfide scrambling highlighted with the reduction approaches, oxidation of S-S bonds into cysteic acids appeared to be the best strategy. Cysteines connectivity was then unambiguously determined for the two peptides, without any disulfide scrambling interference. [less ▲]

Parathormone and bone-specific alkaline phosphatase for the follow-up of bone turnover in hemodialysis patients : Is it so simple?

in Clinica Chimica Acta (2013), 417

Background: Chronic Kidney Disease (CKD) is associated with mineral and bone disorders (MBD). International guidelines suggest that levels of serum parathormone (PTH) or bone-specific alkaline phosphatase ... [more ▼]

Background: Chronic Kidney Disease (CKD) is associated with mineral and bone disorders (MBD). International guidelines suggest that levels of serum parathormone (PTH) or bone-specific alkaline phosphatase (b-ALP) can be used to evaluate MBD in dialysis patients. The evidence remains moderate and based on transversal studies. <br />Methods: We retrospectively investigated the variations of PTH (ΔPTH) and b-ALP (Δb-ALP) serum concentrations over a short (6-weeks) and a long (one-year) period in a monocentric hemodialysis population. The proportion of patients reaching the critical difference (CD) (50% for PTH and 25% for b-ALP) was calculated. <br />Results: Seventy-seven patientswere included. A significant correlation between PTHand b-ALP levelswas found at baseline (r=0.51). By contrast, no correlation was observed between ΔPTH and Δb-ALP over a 6-week interval (r=0.07). The CD for PTH and b-ALP was reached by 19 and 11 patients, respectively, with 2 patients showing consistent variations of both biomarkers. One year later, measurements were repeated in 48 survivors. <br />No correlation was found between ΔPTH and Δb-ALP (r=0.27). The CD for PTH or b-ALP was reached by 24 patients and 28 patients, respectively, with 6 patients (12.5%) showing opposite results for both biomarkers. <br />Conclusion: This study shows the lack of correlation between ΔPTH and Δb-ALP over time in patients under chronic hemodialysis. [less ▲]

Silkworm moths inventory in their natural tapia forest habitat (Madagascar): diversity, population dynamics and host plants

in African Entomology (2013), 21(1), 137-150

Endemic silk moths (Lepidoptera: Lasiocampidae) in Madagascar have been collected and exploited for centuries by local populations either for food or as a source of silk cocoons from which textiles are ... [more ▼]

Endemic silk moths (Lepidoptera: Lasiocampidae) in Madagascar have been collected and exploited for centuries by local populations either for food or as a source of silk cocoons from which textiles are made. Moth natural forest habitat has also been degraded, leading to a drastic decrease in silk moth populations. However, very few scientific reports highlighted these observations well known by the local people.We have inventoried silk moths species in tapia (Uapaca bojeri Baill.) forests located in the central highlands of Madagascar. Inventories have been conducted during one year from August 2009 to July 2010 by sampling transects in Imamo forests. Three species of Lasiocampidae belonging to two genera were found: Borocera cajani Vinson, Borocera marginepunctata Guérin-Méneville and Europtera punctillata Guenée. These three silk moth species are endemic to Madagascar but only one (B. cajani) is commercially exploited in the silk industry. The habitat, host plants, abundance, life cycle and feeding behaviour of these species in their natural habitat are described. [less ▲]

Concern-induced negative affect is associated with the occurrence and content of mind-wandering

in Consciousness & Cognition (2013), 22(2), 442-448

Previous research has shown that the content and frequency of mind-wandering episodes—the occurrence of thoughts that are both stimulus-independent and task-unrelated—are closely related to an ... [more ▼]

Previous research has shown that the content and frequency of mind-wandering episodes—the occurrence of thoughts that are both stimulus-independent and task-unrelated—are closely related to an individual’s future-related concerns. Whether this relationship is shaped by the affective changes that are usually associated with future-related concerns still remains unclear, however. In this study, we induced the anticipation of a negatively valenced event and examined whether the ensuing affective changes were related to the occurrence and content of mind-wandering during an unrelated attentional task. We found that the increase in negative affect following concern induction predicted the general frequency of mind-wandering episodes. Furthermore, mind-wandering episodes specifically directed at the induced concern were related to a lower decrease in negative affect during the attentional task. These results suggest that the negative emotional impact of future-related concerns is an important factor to be taken into consideration for the subsequent occurrence of mind-wandering episodes, which might in turn be involved in the maintenance of negative affect over time. [less ▲]

Behaviours Associated with Acoustic Communication in Nile Tilapia (Oreochromis niloticus)

in PLoS ONE (2013), 8(4), 61467

Two-Parameter Kinematic Theory for Shear Behavior of Deep Beams

in ACI Structural Journal (2013), 110(3), 447-455

This paper presents a kinematic model for deep beams capable of describing the deformed shape of such members in terms of just two primary parameters. The kinematic model is combined with equilibrium ... [more ▼]

This paper presents a kinematic model for deep beams capable of describing the deformed shape of such members in terms of just two primary parameters. The kinematic model is combined with equilibrium equations and stress-strain relationships to form a theory to predict the shear strength and deformations patterns of deep beams at shear failure. These deformation patterns include crack widths, maximum deflections, and the complete displacement field for the beam. The kinematic theory predicts the components of shear strength of deep beams and how they vary with a/d ratio. These components indicate a significant size effect for the shear strength of deep beams even for members with transverse reinforcement. The theory has been validated against a large number of experimental results. [less ▲]

Role of the supplementary motor area in the automatic activation of motor plans in de novo Parkinson's disease patients

in Neuroscience Research (2013)

Malabsorption des hormones thyroïdiennes... ou simple manque de compliance ?

in Revue Médicale de Liège (2013), 68(3), 118-121

Dissecting the mechanisms underlying old male mating advantage in a butterfly

in Behavioral Ecology and Sociobiology (2013)

Selection is expected to maximize an individual’s own genetic reward regardless of the potential fitness consequences for its sexual partners, which may cause sexual conflict. Although performance in ... [more ▼]

Selection is expected to maximize an individual’s own genetic reward regardless of the potential fitness consequences for its sexual partners, which may cause sexual conflict. Although performance in holometabolous insects typically diminishes with age, old male mating advantage has been documented in a few species. Whether this pattern arises from female preference for older males based on, e.g., pheromone blends (intersexual selection), or from increased eagerness to mate in older compared to younger males is currently debated. We explore the mechanistic basis of old male mating advantage, using a series of experiments including behavioral as well as manipulative approaches, in the tropical butterfly Bicyclus anynana. Consistent with the residual reproductive value hypothesis, old male mating advantage was associated with a greater eagerness to mate, evidenced by a two times higher flying and courting activity in older than in younger males. In contrast, we found only limited support for a contribution of female preference for older males based on pheromone composition, although male sex pheromones clearly do play a role in mating success. Our results suggest that male behavior may play a primary role in old male mating advantage, and that pheromones are likely of secondary importance only. Male mating success was related to higher overall pheromone titers rather than variation in a single component. A dominant importance of male behavior in determining mating success may result in sexual conflict. [less ▲]

Influence of sampling effort on saproxylic beetle diversity assessment: Implications for insect monitoring studies in European temperate forests

in Agricultural & Forest Entomology (2013)

Saproxylic beetle diversity monitoring provides a tool for estimating the efficiency of forest conservation measures. Flight interception traps are commonly employed to monitor beetle assemblages ... [more ▼]

Saproxylic beetle diversity monitoring provides a tool for estimating the efficiency of forest conservation measures. Flight interception traps are commonly employed to monitor beetle assemblages, although little explicit knowledge of the efficiency of this trapping method is available. The present study investigated how slight changes in sampling effort can influence species richness and species composition of assemblages in data sets from standard window-flight traps. At both trap and plot levels, an additional year or an additional trap provided a 50% increase in the number of species detected (a 75% increase for rare species) and resulted in a different estimated composition of the assemblages. Adding 2 or 3years of sampling gave twice as many species and resulted in assemblages that were 50% dissimilar. Increases in the detection of species and the dissimilarity of assemblages were similarly affected along a gradient of forest conditions, suggesting that changes in sampling effort were not affected by forest condition. At the forest level, year or trap replication provided smaller increases in species richness (31% and 25%, respectively). Within sites, distance measures in species composition between traps did not differ significantly when based on 1 or 2years of data. Using two traps per plot compared with one trap influenced comparisons between stand types, based on species richness, in 25% of the cases. Species detection was similarly increased by either year replication or trap replication. The results of the present study highlight the significant role played by finescale patterns of habitat structure and inter-annual variation with respect to determining catch size and assemblages of saproxylic species. © 2013 The Royal Entomological Society. [less ▲]

Elévation faible d’hCG en dehors d’un contexte gravidique : à propos de deux cas et revue de la littérature

in Annales de Biologie Clinique (2013), Sous presse

Unexpected finding or persistence of low human chorionic gonadotropin (hCG) levels is not a rare situation. It requires a clinico-biological approach in order to avoid misunderstandings that could lead to ... [more ▼]

Unexpected finding or persistence of low human chorionic gonadotropin (hCG) levels is not a rare situation. It requires a clinico-biological approach in order to avoid misunderstandings that could lead to inappropriate diagnostic or therapeutic attitudes. Outside the context of a pregnancy, persistent low levels of hCG may be associated with various benign and malignant conditions, i.e. quiescent gestational trophoblastic disease (QTD), raised pituitary hCG or false positive elevation caused by circulating heterophile antibodies. We report the cases of two non-pregnant patients with low serum hCG. In the first case, hCG levels raised during several years following a spontaneous abortion. The likelihood of heterophilic antibodies interference was ruled out and extensive clinical investigation excluded the presence of a tumour. The diagnosis was QTD. In the second case, elevated hCG came to light as an incidental finding in a women with chronic renal failure and led the clinicians to question the laboratory. The cause was probably an increase in pituitary hCG consecutive to terminal renal failure. These cases illustrate the importance of understanding the biology of the hCG and the causes of its persistent low elevation, which are reviewed in this article. It is essential to demonstrate clinically the presence of a tumour in order to avoid unnecessary and ineffective chemotherapy and/or hysterectomy. [less ▲]

Enhancing the salience of fluency improves recognition memory performance in mild Alzheimer’s disease

in Journal of Alzheimer's Disease [=JAD] (2013), 33

Recognition memory can rely on recollection (recall of the details from the encoding episode) and familiarity (feeling that some information is old without any recollection). In Alzheimer’s disease (AD ... [more ▼]

Recognition memory can rely on recollection (recall of the details from the encoding episode) and familiarity (feeling that some information is old without any recollection). In Alzheimer’s disease (AD), whereas there is a clear deficit of recollection, the evidence regarding familiarity is mixed, with some studies showing preserved familiarity and others reporting impairment. The current study examined whether recognition memory performance can be improved in AD when the use of familiarity is facilitated by the salience of processing fluency due to an earlier encounter with the information. Fifteen AD patients and 16 healthy controls performed a verbal recognition memory task where the salience of fluency was manipulated by means of letters overlap. Studied and unstudied words were constituted of either two separate sets of letters (no-overlap condition, high fluency salience) or the same set of letters (overlap condition, low fluency salience). The results showed that, although performance was globally poorer in AD patients than in the controls, both groups performed significantly better in the no-overlap condition than in the overlap condition. This suggests that AD patients benefited as much as the controls from the salience of fluency. [less ▲]

Non-graphical solutions to Cattell's scree test

in Methodology: European Journal of Research Methods for the Behavioral and Social Sciences (2013), 9

Most of the strategies that have been proposed to determine the number of components that account for the most variation in a principal components analysis of a correlation matrix rely on the analysis of ... [more ▼]

Most of the strategies that have been proposed to determine the number of components that account for the most variation in a principal components analysis of a correlation matrix rely on the analysis of the eigenvalues and on numerical solutions. The Cattell’s scree test is a graphical strategy with a nonnumerical solution to determine the number of components to retain. Like Kaiser’s rule, this test is one of the most frequently used strategies for determining the number of components to retain. However, the graphical nature of the scree test does not definitively establish the number of components to retain. To circumvent this issue, some numerical solutions are proposed, one in the spirit of Cattell’s work and dealing with the scree part of the eigenvalues plot, and one focusing on the elbow part of this plot. A simulation study compares the efficiency of these solutions to those of other previously proposed methods. Extensions to factor analysis are possible and may be particularly useful with many low-dimensional components. [less ▲]

Fish larvae prefer coral over algal water cues: implications of coral reef degradation

in Marine Ecology. Progress Series (2013), 475

La querelle territoriale entre Samos et Priène : réponse à une invitation au débat

in Topoi (2013), 18(2),

Assessing the ligand properties of 1,3-dimesitylbenzimidazol-2-ylidene in ruthenium-catalyzed olefin metathesis

in Dalton Transactions (2013), 42(20), 7287-7296

The deprotonation of 1,3-dimesitylbenzimidazolium tetrafluoroborate with a strong base afforded 1,3-dimesitylbenzimidazol-2-ylidene (BMes), which was further reacted in situ with rhodium or ruthenium ... [more ▼]

The deprotonation of 1,3-dimesitylbenzimidazolium tetrafluoroborate with a strong base afforded 1,3-dimesitylbenzimidazol-2-ylidene (BMes), which was further reacted in situ with rhodium or ruthenium complexes to afford three new organometallic products. The compounds [RhCl(COD)(BMes)] (COD is 1,5-cyclooctadiene) and cis-[RhCl(CO)2(BMes)] were used to probe the steric and electronic parameters of BMes. Comparison of the percentage of buried volume (%VBur) and of the Tolman electronic parameter (TEP) of BMes with those determined previously for 1,3-dimesitylimidazol-2-ylidene (IMes) and 1,3-dimesitylimidazolin-2-ylidene (SIMes) revealed that the three N-heterocyclic carbenes (NHCs) had very similar profiles. Nonetheless, changes in the hydrocarbon backbone subtly affected the stereoelectronic properties of these ligands. Accordingly, the corresponding [RuCl2(PCy 3)(NHC)(CHPh)] complexes displayed different catalytic behaviors in the ring-closing metathesis (RCM) of α,ω-dienes. In the benchmark cyclization of diethyl 2,2-diallylmalonate, the new [RuCl2(PCy 3)(BMes)(CHPh)] compound (1d) performed slightly better than the Grubbs second-generation catalyst (1a), which was in turn significantly more active than the related [RuCl2(PCy3)(IMes)(CHPh)] initiator (1b). For the formation of a model trisubstituted cycloolefin, complex 1d ranked in-between catalyst precursors 1a and 1b, whereas in the RCM of tetrasubstituted cycloalkenes it lost its catalytic efficiency much more rapidly. [less ▲]

A root chicory MADS-box sequence and the Arabidopsis flowering repressor FLC share common features that suggest conserved function in vernalization and devernalization responses

in The Plant Journal (2013)

Root chicory (Cichorium intybus var. sativum) is a biennial crop, but is harvested for root inulin at the end of the first growing season before flowering. However, cold temperatures might vernalize seeds ... [more ▼]

Root chicory (Cichorium intybus var. sativum) is a biennial crop, but is harvested for root inulin at the end of the first growing season before flowering. However, cold temperatures might vernalize seeds or plantlets, leading to incidental early flowering and hence understanding the molecular basis of vernalization is important. A MADS-box sequence was isolated by RT-PCR and named FLC-LIKE1 (CiFL1) because of its phylogenetic positioning within the same clade as the floral repressor Arabidopsis FLOWERING LOCUS C (AtFLC). Moreover, overexpression of CiFL1 in Arabidopsis caused late flowering and prevented up-regulation of the AtFLC target FLOWERING LOCUS T gene by photoperiod, suggesting functional conservation between root chicory and Arabidopsis. Like AtFLC in Arabidopsis, CiFL1 was repressed during vernalization of seeds or plantlets of chicory, but repression of CiFL1 was unstable whether the post-vernalization temperature was favorable to flowering or whether it devernalized the plants. Instability of CiFL1 repression might be linked to bienniality of root chicory versus the annual life cycle of Arabidopsis. However, reactivation of AtFLC was also observed in Arabidopsis when a high temperature treatment was given straight after seed vernalization, erasing the promotive effect of cold on flowering. Cold-induced downregulation of a MADS-box floral repressor and its reactivation by high temperature thus appear as conserved features of the vernalization and devernalization responses in distant species.This article is protected by copyright. All rights reserved. [less ▲]

Reward uncertainty enhances incentive salience attribution as sign-tracking

in Behavioural Brain Research (2013), 238(1), 53-61

Conditioned stimuli (CSs) come to act as motivational magnets following repeated association with unconditioned stimuli (UCSs) such as sucrose rewards. By traditional views, the more reliably predictive a ... [more ▼]

Conditioned stimuli (CSs) come to act as motivational magnets following repeated association with unconditioned stimuli (UCSs) such as sucrose rewards. By traditional views, the more reliably predictive a Pavlovian CS-UCS association, the more the CS becomes attractive. However, in some cases, less predictability might equal more motivation. Here we examined the effect of introducing uncertainty in CS-UCS association on CS strength as an attractive motivation magnet. In the present study, Experiment 1 assessed the effects of Pavlovian predictability versus uncertainty about reward probability and/or reward magnitude on the acquisition and expression of sign-tracking (ST) and goal-tracking (GT) responses in an autoshaping procedure. Results suggested that uncertainty produced strongest incentive salience expressed as sign-tracking. Experiment 2 examined whether a within-individual temporal shift from certainty to uncertainty conditions could produce a stronger CS motivational magnet when uncertainty began, and found that sign-tracking still increased after the shift. Overall, our results support earlier reports that ST responses become more pronounced in the presence of uncertainty regarding CS-UCS associations, especially when uncertainty combines both probability and magnitude. These results suggest that Pavlovian uncertainty, although diluting predictability, is still able to enhance the incentive motivational power of particular CSs. [less ▲]

Cues from introduced fish alter shelter use and feeding behaviour in adult alpine newts

in Ethology (2013), 119(2), 121-129

Amphibians are particularly affected by alien fish introductions and are declining worldwide. However, the behavioural mechanisms behind the observed cases of coexistence and exclusion patterns between ... [more ▼]

Amphibians are particularly affected by alien fish introductions and are declining worldwide. However, the behavioural mechanisms behind the observed cases of coexistence and exclusion patterns between adult amphibians and fish are poorly understood. In the present study, we aimed at testing the hypothesis that adult newts display different feeding and space use behaviour in the presence of fish cues (i.e. access less food resources and use more shelters than when fish cues are absent). To achieve this we measured behavioural patterns in 100 adult Alpine newts (Mesotriton alpestris) in a replicated laboratory design (20 tanks × 7 replicates across time). Half of trials involved individuals in indirect (visual and olfactory) contact with goldfish (Carassius auratus), a non-predatory species for adult newts. In the presence of fish, significantly more newts hid under shelters than in their absence, but this difference decreased over time. A lower number of newts fed in comparison with controls. These results show that newts responded to fish presence even in the absence of direct contact, but the differences were small. Newts decreased vital activities such as exploration of open areas and feeding. They also adjusted shelter use over time, suggesting a process of habituation or a risk assessment in the absence of direct risk. These results reveal that exploring behavioural patterns can aid in understanding the causes of exclusion and coexistence patterns between fish and amphibians. [less ▲]

Targeting the tumor microenvironment for cancer therapy.

in Clinical Chemistry (2013), 59(1), 85-93

BACKGROUND: With the emergence of the tumor microenvironment as an essential ingredient of cancer malignancy, therapies targeting the host compartment of tumors have begun to be designed and applied in ... [more ▼]

BACKGROUND: With the emergence of the tumor microenvironment as an essential ingredient of cancer malignancy, therapies targeting the host compartment of tumors have begun to be designed and applied in the clinic. CONTENT: The malignant features of cancer cells cannot be manifested without an important interplay between cancer cells and their local environment. The tumor infiltrate composed of immune cells, angiogenic vascular cells, lymphatic endothelial cells, and cancer-associated fibroblastic cells contributes actively to cancer progression. The ability to change these surroundings is an important property by which tumor cells are able to acquire some of the hallmark functions necessary for tumor growth and metastatic dissemination. Thus in the clinical setting the targeting of the tumor microenvironment to encapsulate or destroy cancer cells in their local environment has become mandatory. The variety of stromal cells, the complexity of the molecular components of the tumor stroma, and the similarity with normal tissue present huge challenges for therapies targeting the tumor microenvironment. These issues and their interplay are addressed in this review. After a decade of intensive clinical trials targeting cellular components of the tumor microenvironment, more recent investigations have shed light on the important role in cancer progression played by the noncellular stromal compartment composed of the extracellular matrix. SUMMARY: A better understanding of how the tumor environment affects cancer progression should provide new targets for the isolation and destruction of cancer cells via interference with the complex crosstalk established between cancer cells, host cells, and their surrounding extracellular matrix. [less ▲]

A multi-scale cardiovascular system model can account for the load-dependence of the end-systolic pressure-volume relationship.

in BioMedical Engineering OnLine (2013), 12(1), 8

ABSTRACT: BACKGROUND: The end-systolic pressure-volume relationship is often considered as a load-independent property of the heart and, for this reason, is widely used as an index of ventricular ... [more ▼]

ABSTRACT: BACKGROUND: The end-systolic pressure-volume relationship is often considered as a load-independent property of the heart and, for this reason, is widely used as an index of ventricular contractility. However, many criticisms have been expressed against this index and the underlying time-varying elastance theory: first, it does not consider the phenomena underlying contraction and second, the end-systolic pressure volume relationship has been experimentally shown to be load-dependent. METHODS: In place of the time-varying elastance theory, a microscopic model of sarcomere contraction is used to infer the pressure generated by the contraction of the left ventricle, considered as a spherical assembling of sarcomere units. The left ventricle model is inserted into a closed-loop model of the cardiovascular system. Finally, parameters of the modified cardiovascular system model are identified to reproduce the hemodynamics of a normal dog. RESULTS: Experiments that have proven the limitations of the time-varying elastance theory are reproduced with our model: (1) preload reductions, (2) afterload increases, (3) the same experiments with increased ventricular contractility, (4) isovolumic contractions and (5) flow-clamps. All experiments simulated with the model generate different end-systolic pressure-volume relationships, showing that this relationship is actually load-dependent. Furthermore, we show that the results of our simulations are in good agreement with experiments. CONCLUSIONS: We implemented a multi-scale model of the cardiovascular system, in which ventricular contraction is described by a detailed sarcomere model. Using this model, we successfully reproduced a number of experiments that have shown the failing points of the time-varying elastance theory. In particular, the developed multi-scale model of the cardiovascular system can capture the load-dependence of the end-systolic pressure-volume relationship. [less ▲]

Synthesis and fading of eighteenth-century Prussian blue pigments: a combined study by spectroscopic and diffractive techniques using laboratory and synchrotron radiation sources

in Journal of Synchrotron Radiation (2013), 20(3), 460--473

Experimental and numerical investigation of high-strength steel circular columns subjected to fire

in Journal of Constructional Steel Research (2013), 80

This paper presents an experimental–numerical study on the behaviour of High Strength Steel (HSS) columns at elevated temperature, both on Circular Hollow Sections (CHS) and on a Concrete Filled Tube (CFT ... [more ▼]

This paper presents an experimental–numerical study on the behaviour of High Strength Steel (HSS) columns at elevated temperature, both on Circular Hollow Sections (CHS) and on a Concrete Filled Tube (CFT). The measured yield strength of the circular sections was in the order of 820 MPa. In detail, three HSS CHS and a HSS CFT were tested under the standard ISO fire with constant eccentric compression applied load. The evolution of temperature and deformation patterns were measured by means of a comprehensive instrumentation made of thermocouples and displacement transducers. Numerical analyses were performed and compared with experimental data by employing stress–strain relationships of carbon steel at elevated temperatures provided by the Eurocodes associated to two different sets of reduction factors: i) those provided by the Eurocodes valid up to S460 steel grades; and ii) those proposed in the literature and based on tests on HSS. [less ▲]

Likelihood based inference for semi-competing risks

in Communications in Statistics : Simulation & Computation (2013)

L’âgisme et le jeunisme: Conséquences trop méconnues par les cliniciens et chercheurs!

in Revue de Neuropsychologie, Neurosciences Cognitives et Cliniques (2013), 5(1), 4-8