On simple arrangements of lines and pseudo-lines in P^2 and R^2 with the maximum number of triangles

We give some new advances in the research of the maximum number of triangles that we may obtain in a simple arrangements of n lines or pseudo-lines.Comment: 12 pages, 9 figure

Assessment of forest degradation in the Amazon using multi-sensors techniques: the case of Paragominas (Brazil). O-2215-01

The Amazonian pioneer front region is a mosaic of different forests types and agricultural landscapes resulting from the colonization of the region through forest conversion into pasture and agricultural lands. Fearnside and Guimaraes (1996) showed that 47% of the deforested area is rapidly abandoned. It also appears that logged forests surface is equivalent to deforested areas (Asner et al., 2005). Consequently a degradation gradient exists from low impacted logged forests (depending of the logging intensity) to young secondary (regrowth) forests. To obtain more accurate estimation of carbon stocks, it is important today to take into account the degraded forest gradient including all degraded forest stages between mature intact forests and non-forest areas. The first main challenge is to identify and to characterize the various stages. The identification of forest degradation is still a complex and expansive problem even if it has been focused until now only on logged tropical rainforest (Asner, 2009; Gond and Guitet, 2009; Desclées et al., 2006; Asner et al., 2005; Souza et al., 2003). In parallel estimation of biomass loss in the degraded forest is little-studied. Within temperate and boreal forests some estimation are made by Solberg et al., (2013). The combination of optical remotely sensed data (Landsat-8), radar (Terra-Sar-X) and Lidar (IceSat) have to be studied to analyze the potential of the multisensors techniques to characterize the tropical rainforest degradation (Betbeder et al., 2014). The study presents the first results obtained during the field work at Paragominas (Pará, Brazil) on different forest degradation intensities (Bérenguer et al., 2014). This field database is then compared with multi-sensors remote sensing to better understand multiple interactions and to establish a forest degradation typology. (Texte intégral

Orientational order of carbon nanotube guests in a nematic host suspension of colloidal viral rods

In order to investigate the coupling between the degrees of alignment of elongated particles in binary nematic dispersions, surfactant stabilized single-wall carbon nanotubes (CNTs) have been added to nematic suspensions of colloidal rodlike viruses in aqueous solution.We have independently measured the orientational order parameter of both components of the guest-host system by means of polarized Raman spectroscopy and by optical birefringence, respectively. Our system allows us therefore to probe the regime where the guest particles (CNTs) are shorter and thinner than the fd virus host particles. We show that the degree of order of the CNTs is systematically smaller than that of the fd virus particles for the whole nematic range. These measurements are in good agreement with predictions of an Onsager-type second-viral theory, which explicitly includes the flexibility of the virus particles, and the polydispersity of the CNTs.Comment: 5 pages, 2 figure

A typology of forest degradation un the eastern amazon using remote sensing

The Amazonian pioneer front region is a mosaic of different forests types and agricultural landscapes resulting from the colonization of the region through forest conversion into pasture and agricultural lands. Fearnside and Guimaraes (1996) showed that 47% of the deforested area is rapidly abandoned. It also appears that logged forests surface is equivalent to deforested areas (Asner et al., 2005). Consequently a degradation gradient exists from low-impacted logged forests (depending of the logging intensity) to young secondary (regrowth) forests. To obtain more accurate estimation of carbon stocks, it is important today to take into account the degraded forest gradient including all degraded forest stages between mature intact forests and non-forest areas. The first main challenge is to identify and to characterize the various stages. The identification of forest degradation is still a complex and expansive problem even if it has been focused until now only on logged tropical rainforest (Asner, 2009; Gond and Guitet, 2009; Desclées et al., 2006; Asner et al., 2005; Souza et al., 2003). In parallel estimation of biomass loss in the degraded forest is little-studied. Within temperate and boreal forests some estimation are made by Solberg et al., (2013). The combination of optical remotely sensed data (Landsat-8), radar (Terra-Sar-X) and Lidar (IceSat) have to be studied to analyze the potential of the multi-sensors techniques to characterize the tropical rainforest degradation (Betbeder et al., 2014). The study presents the first results obtained during the field work at Paragominas (Pará, Brazil) on different forest degradation intensities (Bérenguer et al., 2014). This field database is then compared with multi-sensors remote sensing to better understand multiple interactions and to establish a forest degradation typology. (Texte intégral

Artificial Gene Regulatory Networks and Spatial Computation: A Case Study

International audienceThis paper explores temporal and spatial dynamics of a population of Genetic Regulatory Networks (GRN). In order to so, a GRN model is spatially distributed to solve a multi-cellular Artificial Embryogeny problem, and Evolutionary Computation is used to optimize the developmental sequences. An in-depth analysis is provided and show that such a population of GRN display strong spatial synchronization as well as various kind of behavioral patterns, ranging from smooth diffusion to abrupt transition patterns

Artificial Gene Regulatory Network and Spatial Computation: A Case Study

International audienceThis paper explores temporal and spatial dynamics of a population of Genetic Regulatory Networks (GRN). In order to so, a GRN model is spatially distributed to solve a multi-cellular Artificial Embryogeny problem, and Evolutionary Computation is used to optimize the developmental sequences. An in-depth analysis is provided and show that such a population of GRN display strong spatial synchronization as well as various kind of behavioral patterns, ranging from smooth diffusion to abrupt transition patterns

Pain perception after colorectal surgery: A propensity score matched prospective cohort study.

The purpose of this prospective cohort study was to compare multimodal pain management and pain perception after open vs. laparoscopic colorectal surgery within enhanced recovery care. Pain scores at rest and at mobilization were prospectively assessed in consecutive patients using Visual Analog Scales (VAS 0-10) and consumption of different analgesics was recorded daily until 96 hours postoperatively. Uni- and multivariate risk factors for pain peaks (≥ 4/10) were identified by logistic regression and compared between two propensity score matched groups (open vs. laparoscopic). 156 open and 176 laparoscopic procedures were included. Mean VAS scores were consistently < 3 until 96 hours at rest and at mobilization. Patients operated by laparoscopy experienced more pain peaks (≥ 4) within 24 hours (p < 0.05), while patients operated by open approach experienced more pain peaks (≥ 4) during mobilization at 72 hours (p < 0.05). Independent risk factors for insufficient pain control (≥ 4) within 24 hours from surgery were duration of the procedure (OR 3.37, 95%CI 2.03-5.59), emergency surgery (OR 3.01, 95%CI 1.72-5.31), wound infiltration (OR 3.23, 95%CI 0.97-10.70), age < 70 years (OR 2.03, 95% CI 1.18-3.48) and ASA I-II score (OR 2.06, 95% CI 1.19-3.56). The perioperative adding of lidocaine ± ketamine to opioids did not improve postoperative pain perception nor decrease morphine equivalents. In conclusion, overall pain scores were low after colorectal surgery. However, pain peaks remained a concern early after minimally invasive surgery and after epidural removal for open surgery. Multimodal strategies were not superior to opioids alone

Using models for predicting recovery and assess tree species vulnerability in logged tropical forests

Formålet med denne masteroppgaven er å analysere hvilke faktorer som påvirker kredittrangeringer og hvordan rangeringene er for Afrika (Sør for Sahara) i forhold til andre regioner. Ifølge Haque, Mark og Mathieson (2000) var Afrika (Sør for Sahara) regionen med lavest kredittrangeringer i perioden 1980 til 1993. Oppgaven undersøker om dette fortsatt er tilfelle i perioden 1990 til 2010 og videre hvilke faktorer som kan ligge til grunn for denne ulikheten. For å finne ut av dette forsøker jeg først å identifisere korrelasjonen mellom økonomiske, politiske og institusjonelle faktorer. Deretter undersøkes det om Afrika (Sør for Sahara) skiller seg negativt ut i forhold til andre regioner. Utgangspunkt til flere av forklaringsvariablene er hentet fra Cantor og Packer (1996) og Haque et al. (2000). Datamaterialet er samlet inn fra Verdensbanken, Institutional Investor, Det internasjonale pengefondet (IMF), Federal Reserve, Freedom House Index og Quality of Government Institute. Analysen er gjort ved hjelp av en fast effekt modell, der estimeringen er ved MKM og «Least squares dummy variable» (LSDV). Resultatene viser at det er noen få økonomiske variabler som bestemmer nesten 90 prosent av kredittrangeringene. Videre har Afrika (Sør for Sahara) fått lavere rangeringer enn andre regioner i perioden 1990 til 2010. Resultatene indikerer også at vektingen av de ulike variablene endres mellom land og over tid. Beregningene er gjort ved hjelp av Stata 13.1 og Excel 2010.ECON390MASV-SØ

Interactive procedural simulation of paper tearing with sound

International audienceWe present a phenomenological model for the real-time simulation of paper tearing and sound. The model uses as input rotations of the hand along with the index and thumb of left and right hands to drive the position and orientation of two regions of a sheet of paper. The motion of the hands produces a cone shaped deformation of the paper and guides the formation and growth of the tear. We create a model for the direction of the tear based on empirical observation, and add detail to the tear with a directed noise model. Furthermore, we present a procedural sound synthesis method to produce tearing sounds during interaction. We show a variety of paper tearing examples and discuss applications and limitations