Intraperitoneal Adhesions After Open or Laparoscopic Abdominal Procedure: An Experimental Study in the Rat.

in Journal of Laparoendoscopic & Advanced Surgical Techniques. Part A. (2012), 22(7), 651-657

Abstract Background: Adhesion formation is common after abdominal surgery. The incidence and severity of adhesion formation following open or laparoscopic surgery remain controversial. The role of CO(2 ... [more ▼]

Abstract Background: Adhesion formation is common after abdominal surgery. The incidence and severity of adhesion formation following open or laparoscopic surgery remain controversial. The role of CO(2) pneumoperitoneum is also widely discussed. This study aimed to compare adhesion formation following peritoneal injury by electrocoagulation performed through open or laparoscopic procedures in a rat model. Materials and Methods: Sixty male rats were randomized to undergo a 1.5-cm peritoneal injury with unipolar cautery under general anesthesia: open surgery (Group A, n=20), laparoscopic surgery with CO(2) pneumoperitoneum (Group B, n=20), and laparoscopic surgery with air pneumoperitoneum (Group C, n=20). Duration of the procedures was fixed at 90 minutes in all groups, and pneumoperitoneum pressure was kept at 10 mm Hg. Ten days later, the animals underwent a secondary laparotomy to score peritoneal adhesions using qualitative and quantitative parameters. Results: Forty-five rats developed at least one adhesion: 95% in Group A, 83% in Group B, and 55% in Group C (P<.01; Group C versus Group A, P<.01). According to number, thickness, tenacity, vascularization, extent, type, and grading according to the Zuhkle classification, no significant difference was observed between Groups A and B. The distribution of adhesions after open surgery was significantly different than after laparoscopic surgery (P<.001). It is interesting that Group C rats developed significantly fewer adhesions at the traumatized site, and their adhesions had less severe qualitative scores compared with those after open surgery (P<.01). Conclusions: In this animal model, CO(2) laparoscopic surgery did not decrease the formation of postoperative adhesion, compared with open surgery. The difference with the animals operated on with air pneumoperitoneum emphasizes the role of CO(2) in peritoneal injury leading to adhesion formation. [less ▲]

Elaboration et validation de tests de jugement situationnel comme outil de sélection professionnelle : guide méthodologique

in Psychologie du Travail et des Organisations (2012), 18(3), 215-231

Second pilot trials of the STAR-Liege protocol for tight glycemic control in critically ill patients

in BioMedical Engineering OnLine (2012)

Relationships Between Changes in Bone Mineral Density or Bone Turnover Markers and Vertebral Fracture Incidence in Patients Treated with Bazedoxifene

in Calcified Tissue International (2012), 91(4), 244-9

We analyzed the relationships between bone mineral density (BMD) or bone turnover marker (BTM) changes and vertebral fracture incidence in women treated with bazedoxifene using a post hoc analysis from a ... [more ▼]

We analyzed the relationships between bone mineral density (BMD) or bone turnover marker (BTM) changes and vertebral fracture incidence in women treated with bazedoxifene using a post hoc analysis from a 3-year randomized, placebo-controlled study evaluating the effect of bazedoxifene (20 or 40 mg) on fracture risk reduction. BMD was assessed at baseline and every 6 months for 3 years. Osteocalcin and C-telopeptide of type I collagen were assessed at baseline and at 3, 12, and 36 months. Vertebral fractures were assessed with a semiquantitative visual assessment. Data were available for 5,244 women, of whom 3,476 were treated with bazedoxifene. Using a logistic regression analysis and the classical Li approach, the proportion of fracture incidence explained by BMD change after 3 years of bazedoxifene treatment was 29 % for the total hip and 44 % for the femoral neck. The proportion of treatment explained by lumbar BMD change could not be quantified accurately because of the significant interaction between treatment and change in BMD. With the same model, the 12-month BTM changes explained up to 29 % of the fracture risk reduction observed with the two forms of bazedoxifene. In women treated with bazedoxifene, changes in femoral neck BMD, hip BMD, or BTMs explained a moderate proportion of the fracture risk reduction observed during the 3 years of follow-up. However, BMD or BTM changes cannot be recommended for individual monitoring of women treated with bazedoxifene. [less ▲]

A methodological approach to assessing alveolar ridge preservation procedures in humans: hard tissue profile.

in Journal of Clinical Periodontology (2012), 9

AIMS: Multiple surgical protocols using biomaterials have been proposed to limit the typical post-extraction bone resorption. However, because of the heterogeneity of the studies, particularly the ... [more ▼]

AIMS: Multiple surgical protocols using biomaterials have been proposed to limit the typical post-extraction bone resorption. However, because of the heterogeneity of the studies, particularly the differences in assessment methods, it is difficult to determine the superiority of one technique over another. The objective of this study was to describe a new radiographic method to draw a map of alveolar bone remodelling after alveolar ridge preservation procedures to compare different surgical techniques more accurately. The newly developed measuring method was applied to a case series describing a specific preservation technique. MATERIALS AND METHODS: Fourteen extraction sites (in 14 patients) located in the upper anterior maxilla were treated with bovine hydroxyapatite (0.25- to 1-mm particles) and a saddled connective tissue graft. A radiographic three-dimensional assessment of the hard tissues was performed at baseline and 3 months after the procedure. Standardized horizontal measurements were taken at three corono-apical levels (-2, -5 and -9 mm) and at three mesio-distal levels (mesial, centre and distal) in the buccal and palatal aspects. Vertical measurements were also recorded in nine regions superior to the alveolar crest. The measurements were performed by two independent observers and intra- and inter-observer effects were evaluated. RESULTS: No inter- and intra-observer effects were found when analysing the measurements from these two observers. The horizontal dimension of the crest decreased by 1.6 mm (20%) in the cervical regions (-2 mm level), decreased moderately, by 1 mm (12%), at the -5 mm level and decreased very little, 0.5 mm (6%), at the apical (-8 mm) level. The losses were always significantly higher in the buccal than in the palatal aspect. Buccally, the maximal bone remodelling at the cervical level remained below 1 mm. Vertical bone resorption was homogeneous and<1 mm in the nine measured regions. DISCUSSION: The radiographic measuring methodology proved to be reproducible. It can be applied in other clinical settings. It successfully assessed the alveolar ridge preservation technique (BHA+saddle connective tissue graft). [less ▲]

Functional characterization of new allelic polymorphisms identified in the promoter region of the human MxA gene.

in International Journal of Immunogenetics (2012)

The Mx proteins are high-molecular-weight dynamin-like proteins whose expression depends strictly on type-I and -III interferons (IFN). Some isoforms are able to inhibit the life cycle of one or several ... [more ▼]

The Mx proteins are high-molecular-weight dynamin-like proteins whose expression depends strictly on type-I and -III interferons (IFN). Some isoforms are able to inhibit the life cycle of one or several viruses and are thus components of innate immune response. The human MxA protein displays the broadest antiviral spectrum which makes it appear as a key antiviral effector of innate immunity. Allelic polymorphisms located in the MxA gene promoter can be expected to affect the magnitude of MxA mRNA transcription in response to IFNs and therefore to alter the severity of viral diseases in humans. Here, three single nucleotide polymorphism sites (-309, -101 and +20) were examined for their ability to alter MxA gene promoter-driven reporter expression. We show that, besides the previously reported role of 123A and -88T, the presence of -101G is equally important. Moreover, when a promoter construct carries these three critical nucleotides, a first additional positive effect is conferred by a C at position -309 and, in this latter case, a second additional effect is produced by a A at position +20. This finding is clinically useful to improve prediction of IFN-responsiveness in patients not only with viral diseases for which type-I IFN therapy is used. [less ▲]

Improvement of the cellulose hydrolysis yields and hydrolysate concentration by management of enzymes and substrate input

in Cerevisia : Belgian Journal of Brewing and Biotechnology (2012), 37

In order to improve the hydrolysis of cellulose fiber and to obtain highly concentrated hydrolysate, two methods based on successive addition of enzyme and substrate were assessed. The first method, which ... [more ▼]

In order to improve the hydrolysis of cellulose fiber and to obtain highly concentrated hydrolysate, two methods based on successive addition of enzyme and substrate were assessed. The first method, which required only substrate addition, allowed to increase by 50% the hydrolysate concentration and to decrease by 30% enzyme units needed. The second method highlighted the ability to reach very high concentrated hydrolysate (up to 170 g/l) by simultaneous addition of enzyme and substrate. In parallel, relationships between some limiting factors and the yields of hydrolysis were investigated. In conclusion, viscosity evolution of cellulose suspension during hydrolysis step was investigated with an aim to improve the management of enzyme and substrate addition. [less ▲]

Mass spectrometry imaging is moving toward drug protein co-localization

in Trends in Biotechnology (2012), 30(9), 466-474

Mass spectrometry (MS)-based technology provides label-free localization of molecules in tissue samples. Drugs, proteins, lipids and metabolites can easily be monitored in their environment. Resolution ... [more ▼]

Mass spectrometry (MS)-based technology provides label-free localization of molecules in tissue samples. Drugs, proteins, lipids and metabolites can easily be monitored in their environment. Resolution can be achieved down to the cellular level (10–20 mm) for conventional matrix-assisted laser desorption/ionization (MALDI) imaging, or even to the subcellular level for more complex technologies such as secondary ionization mass spectrometry (SIMS) imaging. One question remains: are we going to be able to investigate functional relationships between drugs and proteins and compare with localized phenomena? This review describes the various spatial levels of investigation offered by mass spectrometry imaging (MSI), and the advantages and disadvantages compared with other labeling technologies. [less ▲]

Arrêt "Slovensko": les exigences liées au débat contradictoire dans l'analyse des offres en droit des marchés publics

in Journal de Droit Européen [=JDE] (2012), 7/2012(n°191), 218

The earlier the smaller the better for natalizumab-associated PML: in MRI vigilance veritas ?

in Neurology (2012), 79

Natalizumab-associated progressive multifocal leukoencephalopathy (N-PML) in multiple sclerosis (MS) is due to CNS infection by the opportunistic JC virus (JCV). As of december 2011, 193 confirmed cases ... [more ▼]

Natalizumab-associated progressive multifocal leukoencephalopathy (N-PML) in multiple sclerosis (MS) is due to CNS infection by the opportunistic JC virus (JCV). As of december 2011, 193 confirmed cases of N-PML have been observed, giving rise to an overall risk of approximately 0,202%. N-PML pathogenesis remains partially elusive although risk factors have now been clearly delineated. In patients with prior JCV infection detected by serum anti-JCV antibodies, duration of therapy and prior use of immunosuppressants (IS) increase the risk of N-PML. The clinical outcome of MS patients who developed N-PML was highly variable, ranging from asymptomatic case to varying degrees of neurological disability or even death. It was also observed in real life setting that the earlier N-PML was diagnosed and treated, the better was the clinical outcome. Clinical vigilance is now considered as the established cornerstone of PML risk-management algorithm. Here we present early MRI features of 4 out of 8 N-PML cases, which were observed in Wallonia-Brussels and Northern France in more than 4 years of post-marketing utilization of natalizumab for both regions. We are not aware of the specific context and outcome of the 4 other N-PML cases, which were diagnosed and treated in other centers. The reported cases emphasize that (i) N-PML can have a long presymptomatic course while still being clearly detectable with MR imaging, (ii) N-PML can have a benign outcome provided it is diagnosed and treated early, (iii) a clinically symptomatic N-PML may be a further advanced infection with a poorer prognosis, and (iv) periodic brain MR scans, particularly in high risk situations, are likely to provide earlier detection of N-PML and better outcomes. [less ▲]

La régularité des offres : le point de vue du soumissionnaire

in Marchés et Contrats Publics = Overheidsopdrachten en -Overeenkomsten (2012), 2012/3(2012/3), 313-323

Effect of silica-coated poly(butyl methacrylate)-block-poly(methyl methacrylate) double-shell particles on the mechanical properties of PMMA composites

in Macromolecular Materials and Engineering (2012), 297(9), 887-893

Silica nanoparticles with average diameters of 12nm are grafted with PBMA-b-PMMA double shells through typical ATRP from a Si12-g-(PBMA)Br macroinitiator using 2-BriB as the initiator. A commercially ... [more ▼]

Silica nanoparticles with average diameters of 12nm are grafted with PBMA-b-PMMA double shells through typical ATRP from a Si12-g-(PBMA)Br macroinitiator using 2-BriB as the initiator. A commercially available PMMA homopolymer is used for the preparation of composites with unmodified, silane-modified and double-shell-modified silica particles. Good mechanical properties are obtained for silica double shell containing systems. The silica content in double shell particle systems is varied from 0 to 2.5 wt%. A significant improvement in impact properties is observed. The surface-modified silica particles are characterized by ATR-FTIR, NMR, GPC, and thermal analysis. TEM analysis is used to analyze the nature of dispersion of particles in the composites. [less ▲]

Capacity for Cognitive and Emotional Empathy in Alcohol-Dependent Patients

in Psychology of Addictive Behaviors : Journal of the Society of Psychologists in Addictive Behaviors (2012), 26(3), 371-383

This study assessed two previously unexplored facets of empathy in alcohol-dependent patients (ADs) divided into two groups according to Cloninger’s alcoholism typology: the attribution of intentions ... [more ▼]

This study assessed two previously unexplored facets of empathy in alcohol-dependent patients (ADs) divided into two groups according to Cloninger’s alcoholism typology: the attribution of intentions according to emotional facial expressions (EFEs) and emotional contagion in reaction to EFEs. Twenty-three male Type-I ADs, 21 male Type-II ADs, and 24 male control participants were compared in two computerized tasks. First, participants rated the extent to which an adjective descriptive of personality weighted on interpersonal dimensions (of rejection, aggressiveness, dominance, and affiliation) corresponded with a video of a neutral EFE that changed to an intense EFE. Second, participants evaluated their own emotional states after watching a series of videos that depicted EFEs while their own face was being filmed. The results showed that Type-I ADs attributed more rejection intentions and fewer affiliation intentions to EFEs compared with controls; however, depression might better explain this biased attribution. Furthermore, AD subtypes showed a different pattern of intention attribution according to the emotions that were portrayed and the sex of the stimulus. In addition, angry EFE mimicry was stronger in Type-II ADs than other participants. Finally, ADs expressed fewer positive emotions and more negative emotions than controls when watching EFEs. These findings emphasize the importance of differentiating alcoholism subtypes and contribute to the understanding of AD interpersonal behaviors. [less ▲]

Résumé de la thèse de Christophe BECHET, Traverser la Belgique ? De l’Indépendance au Plan Schlieffen (1839-1905)

in Revue Belge d'Histoire Contemporaine = Belgisch Tijdschrift voor Nieuwste Geschiedenis (2012), 2-3

Reputational damage of operational loss on the bond market: Evidence from the financial industry

in International Review of Financial Analysis (2012), 24

We examine bond market reactions to the announcement of operational losses by financial companies. Thanks to the fact the corporate debt is senior to equity, we interpret the cumulated abnormal returns on ... [more ▼]

We examine bond market reactions to the announcement of operational losses by financial companies. Thanks to the fact the corporate debt is senior to equity, we interpret the cumulated abnormal returns on the bond market of the companies having suffered those losses as a pure reputational impact of operational loss announcements. For a given operational loss, bond returns might be affected at up to three different periods: at the first press release date, when the company recognizes the loss itself and at the settlement date. These impacts hold stronger than for common stocks. We also study the effect of investors' knowledge of the loss amount, and show that the type of operational event and the proportion of the loss in the firm's market value influence the effect of the loss announcement. Cross-sectional analysis indicates that the abnormal return is mostly affected by market-based characteristics for the first press release date, while firm-related characteristics largely affect bond returns upon loss recognition. [less ▲]

Minimal seesaw models and minimal lepton flavor violation.

in Frascati Physics Series Vol. LIV (2012), Frascati Phys.Ser. 55(2012), 31-36

We study the implications of the global U(1)R symmetry present in minimal lepton flavor violating implementations of the seesaw mechanism for neutrino masses. Our discussion is done in the context of ... [more ▼]

We study the implications of the global U(1)R symmetry present in minimal lepton flavor violating implementations of the seesaw mechanism for neutrino masses. Our discussion is done in the context of explicit minimal type-I seesaw scenarios, where depending on the R-charge assignment different models can be constructed. We study the charged lepton flavor violating phenomenology of a concrete realization paying special attention to μ → eγ and μ → 3e [less ▲]

Rimbaud illuminé

in Magazine littéraire (2012)

Compte-rendu de l'ouvrage de R. Hunter, Critical Moments in Classical Literature. Studies in the Ancient View of Literature and Its Uses

in Athenaeum : Studii Periodici di Letteratura e Storia (2012), 100. I-II

Compte-rendu de l'ouvrage de F. Prescendi, Y. Volokhine (éd.), Dans le laboratoire de l’historien des religions. Mélanges offerts à Philippe Borgeaud

in Kernos : Revue Internationale et Pluridisciplinaire de Religion Grecque (2012), 25

La plus jolie et la plus simple de toutes les démonstrations visuelles du théorème de Pythagore

in Losanges (2012), 18

Deux maîtres de la faculté liégeoise de médecine au 19e siècle : Théodore Schwann et Léon Frédéricq

in Cahiers Nouveaux (Les) (2012), 83

Dichroism measurements in forensic fibre examination: Part 5—Pigmented fibres

in Science & Justice : Journal of the Forensic Science Society (2012), 52(3), 161-167

A number of pigmented fibre samples were examined with plane polarized light on their dichroic behaviour by optical light microscopy (OLM) and microspectrophotometry with plane polarized light (MSP-PPL ... [more ▼]

A number of pigmented fibre samples were examined with plane polarized light on their dichroic behaviour by optical light microscopy (OLM) and microspectrophotometry with plane polarized light (MSP-PPL). It was found that about half of the samples show a strong dichroic effect and another 20% have a weak dichroism. Both regular (80%) and inversed dichroic effects (20%) occur. The dichroic characteristics of pigmented fibres can be compared to these of sheet polarizers. It is suggested that the dichroic behaviour of pigmented fibres depends strongly on the crystal structure (shape of the pigment grains) and the draw ratio (orientation of the polymer chains). [less ▲]

Intoxication par ingestion de champignons du genre Inocybe sp. chez un chien

in Monde Vétérinaire (Le) : European Veterinary Magazine (2012), (126), 5-8

A novel CACNA1A mutation results in episodic ataxia with migrainous features without headache

in Cephalalgia : An International Journal of Headache (2012)

Intérêt de la chronothérapie dans le traitement de l'hypertension artérielle

in Revue Médicale Suisse (2012), 8(351), 1604-1610

The interest of chronotherapy in the field of arterial hypertension is progressively rising, especially in treated hypertensive patients characterized by a small decrease of their blood pressure during ... [more ▼]

The interest of chronotherapy in the field of arterial hypertension is progressively rising, especially in treated hypertensive patients characterized by a small decrease of their blood pressure during the night, and therefore often presenting a high cardiovascular risk. There are more and more data showing that administration of one antihypertensive drug in the evening (and even aspirin) can improve the blood pressure control during the night and the day/night blood pressure pattern, and so can diminish the level of risk. The role of chronotherapy also emphasizes the interest of 24 h ambulatory blood pressure monitoring in the management of high risk hypertensive patients. [less ▲]

Quantitative capabilities of four state-of-the-art SPECT-CT cameras

in European Journal of Nuclear Medicine and Molecular Imaging Research (2012), 2

Background. Four state-of-the-art single-photon emission computed tomography-computed tomography (SPECT-CT) systems, namely Philips Brightview, General Electric Discovery NM/CT 670 and Infinia Hawkeye 4 ... [more ▼]

Background. Four state-of-the-art single-photon emission computed tomography-computed tomography (SPECT-CT) systems, namely Philips Brightview, General Electric Discovery NM/CT 670 and Infinia Hawkeye 4, and Siemens Symbia T6, were investigated in terms of accuracy of attenuation and scatter correction, contrast recovery for small hot and cold structures, and quantitative capabilities when using their dedicated three-dimensional iterative reconstruction with attenuation and scatter corrections and resolution recovery. Methods. The National Electrical Manufacturers Association (NEMA) NU-2 1994 phantom with cold air, water, and Teflon inserts, and a homemade contrast phantom with hot and cold rods were filled with 99mTc and scanned. The acquisition parameters were chosen to provide adequate linear and angular sampling and high count statistics. The data were reconstructed using Philips Astonish, General Electric Evolution for Bone, or Siemens Flash3D, eight subsets, and a varying number of iterations. A procedure similar to the one used in positron emission tomography (PET) allowed us to obtain the factor to convert counts per pixel into activity per unit volume. Results. Edge and oscillation artifacts were observed with all phantoms and all systems. At 30 iterations, the residual fraction in the inserts of the NEMA phantom fell below 3.5%. Contrast recovery increased with the number of iterations but became almost saturated at 24 iterations onwards. In the uniform part of the NEMA and contrast phantoms, a quantification error below 10% was achieved. Conclusions. In objects whose dimensions exceeded the SPECT spatial resolution by several times, quantification seemed to be feasible within 10% error limits. A partial volume effect correction strategy remains necessary for the smallest structures. The reconstruction artifacts nevertheless remain a handicap on the road towards accurate quantification in SPECT and should be the focus of further works in reconstruction tomography. [less ▲]

Block bootstrap methods and the choice of stocks for the long run

in Quantitative Finance (2012)

Financial advisors commonly recommend that the investment horizon should be rather long in order to benefit from the ‘time diversification’. In this case, in order to choose the optimal portfolio, it is ... [more ▼]

Financial advisors commonly recommend that the investment horizon should be rather long in order to benefit from the ‘time diversification’. In this case, in order to choose the optimal portfolio, it is necessary to estimate the risk and reward of several alternative portfolios over a long-run given a sample of observations over a short-run. Two interrelated obstacles in these estimations are lack of sufficient data and the uncertainty in the nature of the return generating process. To overcome these obstacles researchers rely heavily on block bootstrap methods. In this paper we demonstrate that the estimates provided by a block bootstrap method are generally biased and we propose two methods of bias reduction. We show that an improper use of a block bootstrap method usually causes underestimation of the risk of a portfolio whose returns are independent over time and overestimation of the risk of a portfolio whose returns are mean-reverting. [less ▲]

Dynamical clustering in driven granular gas

in Europhysics Letters [=EPL] (2012), 99

Driven granular gases present rich dynamical behaviors. Due to inelastic collisions, particles may form dense and slow regions. These clusters emerge naturally during a cooling phenomenon but another ... [more ▼]

Driven granular gases present rich dynamical behaviors. Due to inelastic collisions, particles may form dense and slow regions. These clusters emerge naturally during a cooling phenomenon but another dynamical clustering is observed when the system is continuously excited. In this paper, the physical processes that trigger the transition from a granular gas to a dynamical cluster are evidenced through numerical simulations. At the granular scale, the transition is evidenced by the observation of caging effects. At the scale of the system, the transition is emphasized by density fluctuations. Physical arguments, based on relaxation times, provide an analytical prediction for the edge between dynamical regimes. [less ▲]

Surface Treatment of Polymeric Materials Controlling the Adhesion of Biomolecules

in Journal of Functional Biomaterials (2012), 3

This review describes different strategies of surface elaboration for a better control of biomolecule adsorption. After a brief description of the fundamental interactions between surfaces and ... [more ▼]

This review describes different strategies of surface elaboration for a better control of biomolecule adsorption. After a brief description of the fundamental interactions between surfaces and biomolecules, various routes of surface elaboration are presented dealing with the attachment of functional groups mostly thanks to plasma techniques, with the grafting to and from methods, and with the adsorption of surfactants. The grafting of stimuli-responsive polymers is also pointed out. Then, the discussion is focused on the protein adsorption phenomena showing how their interactions with solid surfaces are complex. The adsorption mechanism is proved to be dependent on the solid surface physicochemical properties as well as on the surface and conformation properties of the proteins. Different behaviors are also reported for complex multiple protein solutions. [less ▲]

Geological Substrates Shape Tree Species and Trait Distributions in African Moist Forests

in PLoS ONE (2012), 7(8), 1-10

Background: Understanding the factors that shape the distribution of tropical tree species at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to ... [more ▼]

Background: Understanding the factors that shape the distribution of tropical tree species at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to (i) assess the importance of environmental factors relative to historical factors for tree species distributions in the semi-evergreen forests of the northern Congo basin; and to (ii) identify potential mechanisms explaining distribution patterns through a trait-based approach. Methodology/Principal Findings: We analyzed the distribution patterns of 31 common tree species in an area of more than 700,000 km² spanning the borders of Cameroon, the Central African Republic, and the Republic of Congo using forest inventory data from 56,445 0.5-ha plots. Spatial variation of environmental (climate, topography and geology) and historical factors (human disturbance) were quantified from maps and satellite records. Four key functional traits (leaf phenology, shade tolerance, wood density, and maximum growth rate) were extracted from the literature. The geological substrate was of major importance for the distribution of the focal species, while climate and past human disturbances had a significant but lesser impact. Species distribution patterns were significantly related to functional traits. Species associated with sandy soils typical of sandstone and alluvium were characterized by slow growth rates, shade tolerance, evergreen leaves, and high wood density, traits allowing persistence on resource-poor soils. In contrast, fast-growing pioneer species rarely occurred on sandy soils, except for Lophira alata. Conclusions/Significance: The results indicate strong environmental filtering due to differential soil resource availability across geological substrates. Additionally, long-term human disturbances in resource-rich areas may have accentuated the observed patterns of species and trait distributions. Trait differences across geological substrates imply pronounced differences in population and ecosystem processes, and call for different conservation and management strategies. [less ▲]

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers

in Cryosphere (The) (2012), 6

In this study, snowpack scenarios are modelled across the French Alps using dynamically downscaled variables from the ALADIN Regional Climate Model (RCM) for the control period (1961–1990) and three ... [more ▼]

In this study, snowpack scenarios are modelled across the French Alps using dynamically downscaled variables from the ALADIN Regional Climate Model (RCM) for the control period (1961–1990) and three emission scenarios (SRES B1, A1B and A2) for the mid- and late 21st century (2021–2050 and 2071–2100). These variables are statistically adapted to the different elevations, aspects and slopes of the Alpine massifs. For this purpose, we use a simple analogue criterion with ERA40 series as well as an existing detailed climatology of the French Alps (Durand et al., 2009a) that provides complete meteorological fields from the SAFRAN analysis model. The resulting scenarios of precipitation, temperature, wind, cloudiness, longwave and shortwave radiation, and humidity are used to run the physical snow model CROCUS and simulate snowpack evolution over the massifs studied. The seasonal and regional characteristics of the simulated climate and snow cover changes are explored, as is the influence of the scenarios on these changes. Preliminary results suggest that the snow water equivalent (SWE) of the snowpack will decrease dramatically in the next century, especially in the Southern and Extreme Southern parts of the Alps. This decrease seems to result primarily from a general warming throughout the year, and possibly a deficit of precipitation in the autumn. The magnitude of the snow cover decline follows a marked altitudinal gradient, with the highest altitudes being less exposed to climate change. Scenario A2, with its high concentrations of greenhouse gases, results in a SWE reduction roughly twice as large as in the low-emission scenario B1 by the end of the century. This study needs to be completed using simulations from other RCMs, since a multi-model approach is essential for uncertainty analysis. [less ▲]

Extension of the Super-Elements Method to the Analysis of Oblique Collision Between Two Ships

in Marine Structures (2012)

Identification and Relative-quantification of Glycans by Matrix-assisted Laser Desorption/Ionization In-Source Decay with Hydrogen Abstraction

in Analytical Chemistry (2012)

The use of specific matrices allows enhancing the scope of in-source decay (ISD) applications in matrix-assisted laser desorption ionization (MALDI) thanks to the specificity of analyte-matrix chemistry ... [more ▼]

The use of specific matrices allows enhancing the scope of in-source decay (ISD) applications in matrix-assisted laser desorption ionization (MALDI) thanks to the specificity of analyte-matrix chemistry. The use of an oxidizing matrix, 5-nitrosalicylic acid (5-NSA) for MALDI-ISD of glycans is shown to promote fragmentation pathways involving radical precursors. Both glycosidic and cross-ring cleavages are promoted by hydrogen abstraction from hydroxyl group of glycans by 5-NSA molecules. Cross-ring cleavage ions are potentially useful in linkage analysis, one of the most critical steps of glycan characterization. Moreover, we show here that isobaric glycans could be distinguished by structure specific ISD ions, and that the molar ratio of glycan isomers in the mixture can be estimated from their fragment ions abundance. The use of 5-NSA also opens the possibility to perform pseudo-MS3 analysis of glycans. Therefore, MALDI-ISD with 5-NSA is a useful method for identification of glycans and semi-quantitative analysis of mixture of glycan isomers. [less ▲]

a complete insect from the Late Devonian period

in Nature (2012), 488

KuaFu: exploring the Sun-Earth connection

in Astronomy and Geophysics (2012), 53

Steve Milan and the KuaFu team explain why this space mission will provide space weather data that will help to understand and mitigate the risks it poses to our increasingly technological society.

Microlensing of the broad line region in 17 lensed quasars

in Astronomy and Astrophysics (2012), 544

When an image of a strongly lensed quasar is microlensed, the different components of its spectrum are expected to be differentially magnified owing to the different sizes of the corresponding emitting ... [more ▼]

When an image of a strongly lensed quasar is microlensed, the different components of its spectrum are expected to be differentially magnified owing to the different sizes of the corresponding emitting region. Chromatic changes are expected to be observed in the continuum while the emission lines should be deformed as a function of the size, geometry and kinematics of the regions from which they originate. Microlensing of the emission lines has been reported only in a handful of systems so far. In this paper we search for microlensing deformations of the optical spectra of pairs of images in 17 lensed quasars with bolometric luminosities between 10[SUP]44.7 - 47.4[/SUP] erg/s and black hole masses 10[SUP]7.6 - 9.8[/SUP] M[SUB]&sun;[/SUB]. This sample is composed of 13 pairs of previously unpublished spectra and four pairs of spectra from literature. Our analysis is based on a simple spectral decomposition technique which allows us to isolate the microlensed fraction of the flux independently of a detailed modeling of the quasar emission lines. Using this technique, we detect microlensing of the continuum in 85% of the systems. Among them, 80% show microlensing of the broad emission lines. Focusing on the most common emission lines in our spectra (C III] and Mg II) we detect microlensing of either the blue or the red wing, or of both wings with the same amplitude. This observation implies that the broad line region is not in general spherically symmetric. In addition, the frequent detection of microlensing of the blue and red wings independently but not simultaneously with a different amplitude, does not support existing microlensing simulations of a biconical outflow. Our analysis also provides the intrinsic flux ratio between the lensed images and the magnitude of the microlensing affecting the continuum. These two quantities are particularly relevant for the determination of the fraction of matter in clumpy form in galaxies and for the detection of dark matter substructures via the identification of flux ratio anomalies. Based on observations made with the ESO-VLT Unit Telescope # 2 Kueyen (Cerro Paranal, Chile; Proposals 074.A-0563, 075.A-0377, 077.A-0155, PI: G. Meylan).Figure 1 and the new spectra presented in this paper are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/544/A62">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/544/A62</A> and via the German virtual observatory <A href="http://dc.g-vo.org/mlqso/q/web/form">http://dc.g-vo.org/mlqso/q/web/form</A>Appendices are available in electronic form at <A href="http://www.aanda.org">http://www.aanda.org</A> [less ▲]

OGLE-2008-BLG-510: first automated real-time detection of a weak microlensing anomaly - brown dwarf or stellar binary?

in Monthly Notices of the Royal Astronomical Society (2012), 424

The microlensing event OGLE-2008-BLG-510 is characterized by an evident asymmetric shape of the peak, promptly detected by the Automated Robotic Terrestrial Exoplanet Microlensing Search (ARTEMiS) system ... [more ▼]

The microlensing event OGLE-2008-BLG-510 is characterized by an evident asymmetric shape of the peak, promptly detected by the Automated Robotic Terrestrial Exoplanet Microlensing Search (ARTEMiS) system in real time. The skewness of the light curve appears to be compatible both with binary-lens and binary-source models, including the possibility that the lens system consists of an M dwarf orbited by a brown dwarf. The detection of this microlensing anomaly and our analysis demonstrate that: (1) automated real-time detection of weak microlensing anomalies with immediate feedback is feasible, efficient and sensitive, (2) rather common weak features intrinsically come with ambiguities that are not easily resolved from photometric light curves, (3) a modelling approach that finds all features of parameter space rather than just the 'favourite model' is required and (4) the data quality is most crucial, where systematics can be confused with real features, in particular small higher order effects such as orbital motion signatures. It moreover becomes apparent that events with weak signatures are a silver mine for statistical studies, although not easy to exploit. Clues about the apparent paucity of both brown-dwarf companions and binary-source microlensing events might hide here. Based in part on data collected by MiNDSTEp with the Danish 1.54m telescope at the ESO La Silla Observatory. [less ▲]

Design, manufacturing, and performance analysis of mid-infrared achromatic half-wave plates with diamond subwavelength gratings

in Applied Optics (2012), 51

In this paper, we present an elegant solution for creating robust monolithic achromatic half-wave plates (HWPs) for the infrared, based on the form birefringence of subwavelength gratings (SWGs) made out ... [more ▼]

In this paper, we present an elegant solution for creating robust monolithic achromatic half-wave plates (HWPs) for the infrared, based on the form birefringence of subwavelength gratings (SWGs) made out of diamond. We use the rigorous coupled wave analysis to design the gratings. Our analysis shows that diamond, besides its outstanding physical and mechanical properties, is a suitable substrate to manufacture mid-infrared HWPs, thanks to its high refractive index which allows etching SWGs with lower aspect ratio. Based on our optized design, we manufactured a diamond HWP for the 11-13.2 µm region, with an estimated mean retardance ~3.143 ± 0.061 rad (180.08 ± 3.51°). In addition, an antireflective grating was etched on the backside of the wave plate, allowing a total tansmittance between 89 and 95% over the band. [less ▲]

DERP6 (ELP5) and C3ORF75 (ELP6) regulate tumorigenicity and migration of melanoma cells as subunits of Elongator

in Journal of Biological Chemistry (2012)

The Elongator complex is composed of 6 subunits (Elp1-Elp6) and promotes RNAPII transcript elongation through histone acetylation in the nucleus as well as tRNA modification in the cytoplasm. This ... [more ▼]

The Elongator complex is composed of 6 subunits (Elp1-Elp6) and promotes RNAPII transcript elongation through histone acetylation in the nucleus as well as tRNA modification in the cytoplasm. This acetyltransferase complex directly or indirectly regulates numerous biological processes ranging from exocytosis and resistance to heat shock in yeast to cell migration and neuronal differentiation in higher eukaryotes. The identity of human ELP1 through ELP4 has been reported but human ELP5 and ELP6 have remained uncharacterized. Here, we report that DERP6 (ELP5) and C3ORF75 (ELP6) encode these subunits of human Elongator. We further investigated the importance and function of these two subunits by a combination of biochemical analysis and cellular assays. Our results show that DERP6/ELP5 is required for the integrity of Elongator and directly connects ELP3 to ELP4. Importantly, the migration and tumorigenicity of melanomaderived cells are significantly decreased upon Elongator depletion through ELP1 or ELP3. Strikingly, DERP6/ELP5 and C3ORF75/ELP6-depleted melanoma cells have similar defects, further supporting the idea that DERP6/ELP5 and C3ORF75/ELP6 are essential for Elongator function. Together, our data identify DERP6/ELP5 and C3ORF75/ELP6 as key players for migration, invasion and tumorigenicity of melanoma cells, as integral subunits of Elongator. [less ▲]

The Exozodiacal Dust Problem for Direct Observations of ExoEarths

in Publications of the Astronomical Society of the Pacific [=PASP] (2012), 124

Debris dust in the habitable zones of stars - otherwise known as exozodiacal dust - comes from extrasolar asteroids and comets and is thus an expected part of a planetary system. Background flux from the ... [more ▼]

Debris dust in the habitable zones of stars - otherwise known as exozodiacal dust - comes from extrasolar asteroids and comets and is thus an expected part of a planetary system. Background flux from the Solar System's zodiacal dust and the exozodiacal dust in the target system is likely to be the largest source of astrophysical noise in direct observations of terrestrial planets in the habitable zones of nearby stars. Furthermore, dust structures like clumps, thought to be produced by dynamical interactions with exoplanets, are a possible source of confusion. In this paper, we qualitatively assess the primary impact of exozodical dust on high-contrast direct imaging at optical wavelengths, such as would be performed with a coronagraph. Then we present the sensitivity of previous, current, and near-term facilities to thermal emission from debris dust at all distances from nearby solar-type stars, as well as our current knowledge of dust levels from recent surveys. Finally, we address the other method of detecting debris dust, through high-contrast imaging in scattered light. This method is currently far less sensitive than thermal emission observations, but provides high spatial resolution for studying dust structures. This paper represents the first report of NASA's Exoplanet Exploration Program Analysis Group (ExoPAG). [less ▲]

Clinical sedation and bispectral index in burn children receiving gamma-hydroxybutyrate.

in Paediatric Anaesthesia (2012), 22(8), 799-804

Background:  Gamma-hydroxybutyrate (GHB) may be an interesting hypnotic agent in burn patients because of its good respiratory or hemodynamic tolerance. However, its clinical and electroencephalographic ... [more ▼]

Background:  Gamma-hydroxybutyrate (GHB) may be an interesting hypnotic agent in burn patients because of its good respiratory or hemodynamic tolerance. However, its clinical and electroencephalographic (EEG) sedative effects are not yet described in children. The aim of this prospective and randomized study was to assess clinical and EEG effects of increasing intravenous (IV) doses of GHB in burn children requiring sedation for burn wound cares. Methods:  Thirty six children hospitalized in a burn care unit were included and randomly assigned into three groups (G) according to the single IV dose of GHB they received before burn wound care: 10 mg·kg(-1) in G10, 25 mg·kg(-1) in G25, or 50 mg·kg(-1) in G50. All patients received oral premedication (morphine and hydroxyzine) 30 min before GHB injection. Respiratory rate, heart rate, pulse oximetry, and bispectral index (BIS) were continuously monitored. Depth of sedation was clinically assessed using Observer's Assessment of Alertness and Sedation (OAAS) Score, every 2 min until recovery (i.e., OAAS = 4). Results:  Median age was 17.5 [12-34] months. Whatever the dose, BIS decreased after IV GHB. Nadir value of BIS was significantly lower in G25 and G50 than in G10, as was for OAAS score. Nadir values were reached after same delays in G25 and G50. Duration of sedation was dose-dependant. Conclusion:  Bispectral index decreased after GHB injection and was correlated with OAAS score. Deep sedation can be safely achieved with IV doses of 25 or 50 mg·kg(-1) , but the last dose was associated with prolonged duration of clinical sedation. [less ▲]

Estimating the p-mode frequencies of the solar twin 18 Scorpii

in Astronomy and Astrophysics (2012), 544

Solar twins have been a focus of attention for more than a decade, because their structure is extremely close to that of the Sun. Today, thanks to high-precision spectrometers, it is possible to use ... [more ▼]

Solar twins have been a focus of attention for more than a decade, because their structure is extremely close to that of the Sun. Today, thanks to high-precision spectrometers, it is possible to use asteroseismology to probe their interiors. Our goal is to use time series obtained from the HARPS spectrometer to extract the oscillation frequencies of 18 Sco, the brightest solar twin. We used the tools of spectral analysis to estimate these quantities. We estimate 52 frequencies using an MCMC algorithm. After examination of their probability densities and comparison with results from direct MAP optimization, we obtain a minimal set of 21 reliable modes. The identification of each pulsation mode is straightforwardly accomplished by comparing to the well-established solar pulsation modes. We also derived some basic seismic indicators using these values. These results offer a good basis to start a detailed seismic analysis of 18 Sco using stellar models. [less ▲]

Risk assessment for furan contamination through the food chain in Belgian children

in Food Additives & Contaminants (2012), 29(8), 1219-1229

Young, old, pregnant and immuno-compromised persons are of great concern for risk assessors as they represent the sub-populations most at risk. The present paper focuses on risk assessment linked to furan ... [more ▼]

Young, old, pregnant and immuno-compromised persons are of great concern for risk assessors as they represent the sub-populations most at risk. The present paper focuses on risk assessment linked to furan exposure in children. Only the Belgian population was considered because individual contamination and consumption data that are required for accurate risk assessment were available for Belgian children only. Two risk assessment approaches, so called deterministic and probabilistic, were applied and their results were compared for the estimation of the daily intake. A significant difference between the average Estimated Daily Intake (EDI) was underlined between the deterministic (419 ng * (kgb.w. * day)-1) and the probabilistic (583 ng * (kgb.w. * day)-1) approaches, which results from the mathematical treatment of the null consumption and contamination data. The risk was characterized by two ways: (1) the classical approach by comparison of the EDI to a reference dose (RfDchronic-oral) and (2) the most recent approach, namely the Margin of Exposure (MoE) approach. Both reached similar conclusions: the risk level is not of a major concern, but is neither negligible. In the first approach, only 2.7% or 6.6% (respectively in the deterministic and in the probabilistic way) of the studied population presented an EDI above the RfDchronic-oral. In the second approach, the percentage of children displaying a MoE above 10,000 and below 100 is 3% - 0% and 20% - 0.01% in the deterministic and probabilistic modes respectively. In addition, children were compared to adults and significant differences between the contamination patterns were highlighted. Whilst major contamination was linked to coffee consumption in adults (55%), no item predominantly contributed to the contamination in children. The most important were soups (19%), dairy products (17%), pasta and rice (11%), fruit and potatoes (9% each). [less ▲]

Detection of new allelic polymorphisms in the human MxA gene

in Molecular Biology Reports (2012), 39(8), 8533-8538

The interferon-inducible human MxA protein plays an important role in innate defense against an array of viruses. One might expect allelic diversity at the MxA locus to influence the timing and magnitude ... [more ▼]

The interferon-inducible human MxA protein plays an important role in innate defense against an array of viruses. One might expect allelic diversity at the MxA locus to influence the timing and magnitude of its expression or even the range of viruses whose biological cycle is inhibited by the encoded product. Here we have collected 267 samples of genomic DNA from three distinct populations (European, Asian, and African) and have systematically sequenced the promoter of the MxA gene and its 17 exons in order to inventory its allelic variants. Fifteen single-nucleotide polymorphisms were detected, four of which had never been identified before. Two of these, located in the promoter (at positions -309 and -101 respectively), might affect the MxA expression pattern. The other two result in substitutions (Gly255Glu and Val268Met) in the protein’s N-terminal region that might directly affect its antiviral function. [less ▲]

Reynolds-Averaged Navier-Stokes Simulations of the HyShot II Scramjet

in AIAA Journal (2012), 50(8), 1717-1732

The internal flow in the HyShot II scramjet is investigated through numerical simulations. A computational infrastructure to solve the compressible Reynolds-Averaged Navier-Stokes equations on ... [more ▼]

The internal flow in the HyShot II scramjet is investigated through numerical simulations. A computational infrastructure to solve the compressible Reynolds-Averaged Navier-Stokes equations on unstructured meshes is introduced. A combustion model based on tabulated chemistry is considered to incorporate a detailed chemical kinetics mechanics while retaining a low computational cost. Both non-reactive and reactive simulations have been performed and results are compared with ground test measurements obtained at DLR. Different turbulence models were tested and the dependence on the mesh is assessed through grid refinement. The comparison with experimental data shows good agreement, although for the reactive case the computed heat fluxes at the wall are higher than measurements. A sensitivity analysis on the turbulent Schmidt and Prandtl numbers shows that the choice of these parameters has a strong influence on the results. In particular, variations of the turbulent Prandtl number lead to large changes in the heat flux at the walls. Finally, the inception of thermal choking is investigated by increasing the equivalence ratio, whereby a normal shock is created locally and moves upstream leading to a large increase in the maximum pressure. Nevertheless a large portion of the flow is still supersonic. [less ▲]

Mesenchymal stem cells and neural crest stem cells from adult bone marrow: characterization of their surprising similarities and differences.

in Cellular and Molecular Life Sciences : CMLS (2012), 69(15), 2593-2608

The generation of neuronal cells from stem cells obtained from adult bone marrow is of significant clinical interest in order to design new cell therapy protocols for several neurological disorders. The ... [more ▼]

The generation of neuronal cells from stem cells obtained from adult bone marrow is of significant clinical interest in order to design new cell therapy protocols for several neurological disorders. The recent identification in adult bone marrow of stem cells derived from the neural crest stem cells (NCSC) might explain the neuronal phenotypic plasticity shown by bone marrow cells. However, little information is available about the nature of these cells compared to mesenchymal stem cells (MSC), including their similarities and differences. In this paper, using transcriptomic as well as proteomic technologies, we compared NCSC to MSC and stromal nestin-positive cells, all of them isolated from adult bone marrow. We demonstrated that the nestin-positive cell population, which was the first to be described as able to differentiate into functional neurons, was a mixed population of NCSC and MSC. More interestingly, we demonstrated that MSC shared with NCSC the same ability to truly differentiate into Tuj1-positive cells when co-cultivated with paraformaldehyde-fixed cerebellar granule neurons. Altogether, those results suggest that both NCSC and MSC can be considered as important tools for cellular therapies in order to replace neurons in various neurological diseases. [less ▲]

Robustness of steel and composite buildings suffering the dynamic loss of a column

in Structural Engineering International (2012), 22(3), 323-329

In case a vehicle impacts a building frame, one or several columns may be damaged or even completely destroyed. Nowadays, it is a concern to mitigate the risk of progressive collapse of the whole ... [more ▼]

In case a vehicle impacts a building frame, one or several columns may be damaged or even completely destroyed. Nowadays, it is a concern to mitigate the risk of progressive collapse of the whole structure further to such a localised exceptional event. Although this robustness requirement is part of several design codes, very few precise practical guidelines are provided, especially as far as dynamic failures are concerned. The present research focuses on building frames suffering the loss of one internal column. The dynamic response is more specifically investigated, with the aim to understand this behaviour in order to eventually derive simplified procedures for robustness assessment. This paper first briefly presents the main previous achievements related to the prediction of the static response of a plane frame suffering a column loss. The investigations into the dynamic behaviour are then summarised, which constitutes the core topic of the paper. For sake of simplicity, the dynamic response is described using a basic substructure that was proved to show many similarities in behaviour with a global frame losing a column. A simplified model is finally developed for the prediction of the considered system dynamic response. [less ▲]

A pulsation zoo in the hot subdwarf B star KIC 10139564 observed by Kepler

in Monthly Notices of the Royal Astronomical Society (2012), 424

We present our analyses of 15 months of Kepler data on KIC 10139564. We detected 57 periodicities with a variety of properties not previously observed all together in one pulsating subdwarf B (sdB) star ... [more ▼]

We present our analyses of 15 months of Kepler data on KIC 10139564. We detected 57 periodicities with a variety of properties not previously observed all together in one pulsating subdwarf B (sdB) star. Ten of the periodicities were found in the low-frequency region, and we associate them with nonradial g modes. The other periodicities were found in the high-frequency region, which are likely p modes. We discovered that most of the periodicities are components of multiplets with a common spacing. Assuming that multiplets are caused by rotation, we derive a rotation period of 25.6 ± 1.8 d. The multiplets also allow us to identify the pulsations to an unprecedented extent for this class of pulsator. We also detect l ≥ 2 multiplets, which are sensitive to the pulsation inclination and can constrain limb darkening via geometric cancellation factors. While most periodicities are stable, we detected several regions that show complex patterns. Detailed analyses showed that these regions are complicated by several factors. Two are combination frequencies that originate in the super-Nyquist region and were found to be reflected below the Nyquist frequency. The Fourier peaks are clear in the super-Nyquist region, but the orbital motion of Kepler smears the Nyquist frequency in the barycentric reference frame and this effect is passed on to the sub-Nyquist reflections. Others are likely multiplets but unstable in amplitudes and/or frequencies. The density of periodicities also makes KIC 10139564 challenging to explain using published models. This menagerie of properties should provide tight constraints on structural models, making this sdB star the most promising for applying asteroseismology. To support our photometric analysis, we have obtained spectroscopic radial-velocity measurements of KIC 10139564 using low-resolution spectra in the Balmer-line region. We did not find any radial-velocity variation. We used our high signal-to-noise average spectrum to improve the atmospheric parameters of the sdB star, deriving Teff = 31 859 K and log g = 5.673 dex. Based also on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. [less ▲]

First-principles modeling of the thermoelectric properties of SrTiO3/SrRuO3 superlattices

in Physical Review. B, Condensed Matter and Materials Physics (2012), 86

Using a combination of first-principles simulations, based on density functional theory and Boltzmann’s semiclassical theory, we have calculated the transport and thermoelectric properties of the half ... [more ▼]

Using a combination of first-principles simulations, based on density functional theory and Boltzmann’s semiclassical theory, we have calculated the transport and thermoelectric properties of the half-metallic twodimensional electron gas confined in single SrRuO3 layers of SrTiO3/SrRuO3 periodic superlattices. Close to the Fermi energy, we find that the semiconducting majority-spin channel displays a very large in-plane component of the Seebeck tensor at room temperature, S ∼ 1500 μV/K, and the minority-spin channel shows good in-plane conductivity, σ = 2.5 (m cm)−1. However, we find that the total power factor and thermoelectric figure of merit for reduced doping is too small for practical applications. Our results support that the confinement of the electronic motion is not the only thing that matters to describe the main features of the transport and thermoelectric properties with respect the chemical doping, but the shape of the electronic density of states, which in our case departs from the free-electron behavior, is also important. The evolution of the electronic structure, electrical conductivity, Seebeck coefficient, and power factor as a function of the chemical potential is explained by a simplified tight-binding model. We find that the electron gas in our system is composed by a pair of one-dimensional electron gases orthogonal to each other. This reflects the fact the physical dimensionality of the electronic system (1D) can be even smaller than that of the spacial confinement of the carriers (2D). [less ▲]

Model recovery anti-windup for continuous-time rate and magnitude saturated linear plants

in Automatica (2012), 48(8), 15021513

In this paper two approaches are given for anti-windup design for nonlinear control systems with linear plants subject to limitations both in the magnitude and the rate of variation of the control input ... [more ▼]

In this paper two approaches are given for anti-windup design for nonlinear control systems with linear plants subject to limitations both in the magnitude and the rate of variation of the control input. Both approaches are based on the so-called Model Recovery Anti-windup (MRAW) framework. The first approach is built by treating the rate+magnitude saturation as a single dynamic nonlinearity, while in the second one, the dynamic compensator dynamics is extended with extra states to treat the two saturations separately. Both approaches lead to global stability with exponentially stable plants and local stability in all other cases. For both approaches, stability and performance guarantees are proven, numerical recipes are given and the relative merits are comparatively highlighted on a simulation example. [less ▲]