Detection of Change--Points in the Spectral Density. With Applications to ECG Data

We propose a new method for estimating the change-points of heart rate in the orthosympathetic and parasympathetic bands, based on the wavelet transform in the complex domain and the study of the change-points in the moments of the modulus of these wavelet transforms. We observe change-points in the distribution for both bands.Comment: proceeding of the workshop 'Fouille de donn\'ees temporelles et analyse de flux de donn\'ees' EGC'2009, january 27, Strasbourg, Franc

COUPLER SAVOIRS ACADEMIQUES ET METHODES INFORMATIQUES POUR MIEUX ORIENTER LES OBSERVATIONS DE TERRAIN

International audienceBiological control through conservation agriculture or enhanced control via natural enemies are cost-effective strategies suitable for implementation in farming conditions of sub-Saharan African countries. One issue concerns the identification of host plants of crop pests and their parasitoïds in natural habitats. The situation regarding cereal stem borers identified in lowland regions in Benin was investigated. The lepidopteran pests identified were Sesamia calamistis, Busseola fusca, Mussidia nigrivenella, Coniesta ignefusalis and Thaumatotibia leucrotreta. A database was compiled from published findings to better target field studies on their secondary host plants and parasitoids. The information collected, compared with plant survey data, indicated that the Poaceae species Sporobolus pyramidalis and Rottboellia cochinchinensis, and species belonging to the Hyparrhenia and Pennisetum genera should be monitored in priority.RÉSUMÉ La lutte biologique par conservation ou par renforcement de la régulation par les ennemis naturels apparait comme une stratégie économiquement adaptée au contexte de l'agriculture des pays d'Afrique sub-saharienne. Une question posée est celle de l'identification des plantes-hôtes des ravageurs des cultures et de leurs parasitoïdes dans les habitats naturels. Le cas des lépidoptères foreurs des céréales a été abordée dans un bas-fonds au Bénin. Les lépidoptères ravageurs identifiés ont été Sesamia calamistis, Busseola fusca, Mussidia nigrivenella, Coniesta ignefusalis et Thaumatotibia leucrotreta. Afin de mieux orienter les observations de terrain sur leurs plantes-hôtes secondaires et leurs parasitoïdes, une base de données a été constituée à partir des travaux publiés. Les informations ainsi recueillies, croisées avec les relevés floristiques, indiquent les espèces à observer prioritairement, les Poacées des genres Hyparrhenia et Pennisetum et les espèces Sporobolus pyramidalis et Rottboellia cochinchinensis

The Horsehead mane: Towards an observational benchmark for chemical models

After a discussion about the need for observational benchmark for chemical models, we explain 1) why the Horsehead western edge is well suited to serve as reference for models and 2) the steps we are taking toward this goal. We summarize abundances obtained to date and we show recent results

Isotope geochemistry and petrogenesis of peralkaline Middle Miocene ignimbrites from central Sonora: relationship with continental break-up and the birth of the Gulf of California

Middle Miocene peralkaline ignimbrites constitute a specific geodynamic marker of the early stage of opening of the Gulf of California, preserved either in central Sonora or the Puertecitos area, in Baja California. Very uniform ages (12-12.5 Ma) obtained on these rocks show that this volcanic episode corresponds to a specific stage in the tectonic evolution of the proto-gulf area. Field observations and slightly different Sr and Nd isotopic signatures support eruptions from several small volume magma batches rather than from a large-volume caldera forming event. Isotopic ratios help to constrain the petrogenesis of the peralkaline liquids by fractional crystallization of transitional basalts in a shallow reservoir, with slight contamination by Precambrian upper crustal material. Less differentiated glomeroporphyritic icelandites erupted at about 11 Ma, mark an increase in the magma production rate and highlight an easier access to the surface, illustrating an advanced stage in the weakening of the continental crust. The tilting of the Middle Tertiary sequences results from a major change in the tectonic regime, from E-W extension giving rise to N-S grabens, to NNW-SSE strike-slip motion that can be related to the transfer of Baja California from North America to the Pacific plate. The location of peralkaline volcanism coincides with the southern edge of the Precambrian crust and the southernmost extension of the California slab window at 12.5 Ma

The economics of ecosystem services of tree-based intercropping systems

Paper presented at the 13th North American Agroforesty Conference, which was held June 19-21, 2013 in Charlottetown, Prince Edward Island, Canada.In Poppy, L., Kort, J., Schroeder, B., Pollock, T., and Soolanayakanahally, R., eds. Agroforestry: Innovations in Agriculture. Proceedings, 13th North American Agroforestry Conference, Charlottetown, Prince Edward Island, Canada, June 19-21, 2013.The paper aims to determine the potential environmental benefits of multifunctional tree-based intercropping (TBI) systems. Here we evaluate ten ecosystem services using a mix of mathematical models for quantification and economic valuation. The results reveal a total annual margin of 2 558 CAN$ha-1y-1. The economic value of combined non-market services is 1 634 CAN$ ha-1y-1, which is higher than the value of marketable products (i.e. timber and agricultural products). The present value of the services for a rotation of 40 years is 54 782 CAN$ ha-1, about a third of which is contributed by agricultural products. Water quality regulation ranked highest among the non-market benefits followed by air quality maintenance, soil quality regulation, biological control, and pollination.Mahbubul Alam (1), Alain Olivier (1), Alain Paquette (2), J�rôme Dupras (3), Jean-Pierre Rev�ret (4) and Christian Messier (5) ; 1. D�partement de phytologie, Facult� des sciences de l'agriculture et de l'alimentation, Universit� Laval, Qu�bec City, G1V 0A6, Canada. 2. D�partement des sciences biologiques, Universit� du Qu�bec � Montr�al, Case postale 8888, Succursale Centre-ville, Montr�al, H3C 3P8, Canada. 3. D�partement de g�ographie, Universit� de Montr�al, Montr�al, Canada. 4. D�partement strat�gie, responsabilit� sociale et environnementale, Universit� du Qu�bec � Montr�al, Montr�al, Canada. 5. Institut des Sciences de la For�t temp�r�e (ISFORT), Universit� du Qu�bec en Outaouais, Ripon, JOV 1V0, QC, Canada.Includes bibliographical references

Recherches immunologiques sur la péripneumonie. VIII - Présence possible d'un antigène à activité sérologique Forssman chez Mycoplasma mycoïdes

Les auteurs montrent clairement qu'une activité sérologique de type Forssman peut être ajoutée ou coexistante à une activité sérologique anti-Mycoplasma mycoïdes. Par ailleurs l'hyperimmunisation de lapins selon la méthode de Forssman provoque l'apparition d'anticorps fixant le complément en présence de l'antigène péripneumonique. La nature de cet antigène est discutée. Le galactane n'aurait par lui-même qu'une très faible activité Forssman, mais celle-ci pourrait devenir complète par couplage avec un autre antigène. Il semble qu'il n'y ait aucune relation entre cette activité Forssman et les anticorps anti-Mycoplasma mycoïdes que l'on trouve normalement à faible titre dans les sérums de bovins vivant en région indemne (France, Afrique

HIV-1 Viremia Prevents the Establishment of Interleukin 2–producing HIV-specific Memory CD4+ T Cells Endowed with Proliferative Capacity

CD4+ T cell responses are associated with disease control in chronic viral infections. We analyzed human immunodeficiency virus (HIV)-specific responses in ten aviremic and eight viremic patients treated during primary HIV-1 infection and for up to 6 yr thereafter. Using a highly sensitive 5-(and-6)-carboxyfluorescein diacetate-succinimidyl ester–based proliferation assay, we observed that proliferative Gag and Nef peptide-specific CD4+ T cell responses were 30-fold higher in the aviremic patients. Two subsets of HIV-specific memory CD4+ T cells were identified in aviremic patients, CD45RA− CCR7+ central memory cells (Tcm) producing exclusively interleukin (IL)-2, and CD45RA− CCR7− effector memory cells (Tem) that produced both IL-2 and interferon (IFN)-γ. In contrast, in viremic, therapy-failing patients, we found significant frequencies of Tem that unexpectedly produced exclusively IFN-γ. Longitudinal analysis of HIV epitope–specific CD4+ T cells revealed that only cells that had the capacity to produce IL-2 persisted as long-term memory cells. In viremic patients the presence of IFN-γ–producing cells was restricted to periods of elevated viremia. These findings suggest that long-term CD4+ T cell memory depends on IL-2–producing CD4+ T cells and that IFN-γ only–producing cells are short lived. Our data favor a model whereby competent HIV-specific Tcm continuously arise in small numbers but under persistent antigenemia are rapidly induced to differentiate into IFN-γ only–producing cells that lack self-renewal capacity

Virus-induced changes in root volatiles attract soil nematode vectors to infected plants

Plant-derived volatiles mediate interactions among plants, pathogenic viruses, and viral vectors. These volatile-dependent mechanisms have not been previously demonstrated belowground, despite their likely significant role in soil ecology and agricultural pest impacts. We investigated how the plant virus, tobacco rattle virus (TRV), attracts soil nematode vectors to infected plants. We infected Nicotiana benthamiana with TRV and compared root growth relative to that of uninfected plants. We tested whether TRV-infected N. benthamiana was more attractive to nematodes 7 d post infection and identified a compound critical to attraction. We also infected N. benthamiana with mutated TRV strains to identify virus genes involved in vector nematode attraction. Virus titre and associated impacts on root morphology were greatest 7 d post infection. Tobacco rattle virus infection enhanced 2-ethyl-1-hexanol production. Nematode chemotaxis and 2-ethyl-1-hexanol production correlated strongly with viral load. Uninfected plants were more attractive to nematodes after the addition of 2-ethyl-1-hexanol than were untreated plants. Mutation of TRV RNA2-encoded genes reduced the production of 2-ethyl-1-hexanol and nematode attraction. For the first time, this demonstrates that virus-driven alterations in root volatile emissions lead to increased chemotaxis of the virus's nematode vector, a finding with implications for sustainable management of both nematodes and viral pathogens in agricultural systems.</p

A Systematic Review of the Perforated Duodenal Diverticula: Lessons Learned from the Last Decade

Background: The perforated duodenal diverticulum remains a rare clinical entity, the optimal management of which has not been well established. Historically, primary surgery has been the preferred treatment modality. This was called into question during the last decade, with the successful application of non-operative therapy in selected patients. The aim of this systematic review is to identify cases of perforated duodenal diverticula published over the past decade and to assess any subsequent evolution in treatment. Methods: A systematic review of English and non-English articles reporting on perforated duodenal diverticula using MEDLINE (2008-2020) was performed. Only cases of perforated duodenal diverticula in adults (> 18 years) that reported on diagnosis and treatment were included. Results: Some 328 studies were identified, of which 31 articles met the inclusion criteria. These studies included a total of 47 patients with perforated duodenal diverticula. This series suggests a trend towards conservative management with 34% (16/47) of patients managed non-operatively. In 31% (5/16) patients initially managed conservatively, a step-up approach to surgical intervention was required. Conclusion: Conservative treatment of perforated duodenal diverticula appears to be an acceptable and safe treatment strategy in stable patients without signs of peritonitis under careful observation. For patients who fail to respond to conservative treatment, a step-up approach to percutaneous drainage or surgery can be applied. If surgery is required, competence in techniques ranging from simple diverticulectomy to Roux-en-Y gastric diversion or even Whipple's procedure may be required depending on tissue friability and diverticular collar size. Keywords: Duodenal diverticulum; Duodenum; Management; Perforation