Callose-associated silica deposition in Arabidopsis

The mechanism of biological silicification in plants remains to be elucidated. There are strong arguments supporting a role for the plant extracellular matrix and the β-1-3-glucan, callose, has been identified as a possible template for silica deposition in the common horsetail, Equisetum arvense. The model plant Arabidopsis thaliana, which is not known as a silica accumulator, can be engineered to produce mutants in which, following a pathogen-associated molecular pattern challenge, callose production in leaves is either induced (35S:PMR4-GFP) or not (pmr4). We have grown these mutants hydroponically in the presence of added silicon to test if the induction of callose results in greater silica deposition in the leaves. Callose induction was identified throughout leaf tissue of wild type Arabidopsis and the mutant 35S:PMR4-GFP but not in the mutant pmr4. Similarly both wild type Arabidopsis and the mutant 35S:PMR4-GFP showed extensive silicification of leaf tissue while the pmr4 mutant deposited very little silica in its leaf tissues. Wild type Arabidopsis and the mutant 35S:PMR4-GFP responded to a pathogen-like challenge by producing both callose and biogenic silica coincidently in their leaf tissues. Trichomes in particular showed both callose deposition and extensive silicification. The lack of both induced callose deposition and subsequent silicification in the pmr4 mutant strongly suggested that the biochemistry of callose formation and deposition were allied to biological silicification in Arabidopsis

Monitoring à long terme d'une liaison optique aérienne cohérente à 40 Gbit/s

Le développement des formats de modulation à multiplexage en polarisation a suscité un regain d'intérêt pour l'étude des effets de polarisation dans les liaisons optiques cohérentes, qui pourraient engendrer des pannes de système. L'étude de ces effets de polarisation pourrait permettre de dimensionner les modules de traitement de signal, qui sont utilisés dans les transpondeurs cohérents, et dont le rôle est notamment de compenser les effets de polarisation tels que la dispersion modale de polarisation (PMD). Ce mémoire présente l'analyse des mesures de paramètres de performance et d'activité de polarisation effectuées sur une liaison optique cohérente à 40 Gbit/s déployée principalement sur un câble de garde à fibre optique (OPGW). Les mesures ont été faites durant plus de deux ans au moyen d'un transpondeur cohérent à double polarisation et à modulation de phase différentielle décalée en quadrature (DP-QPSK) et d'un polarimètre. La première partie concerne l’étude de l’évolution temporelle des différents paramètres caractérisant le système de transmission, tels que le taux d’erreur sur les bits (BER), le délai de groupe différentiel (DGD) ou encore la dispersion modale de polarisation (PMD). Ces paramètres ont été mesurés par un transpondeur cohérent DP-QPSK à 40 Gbit/s, avec un taux d’échantillonnage de 1 kHz, durant plusieurs saisons afin de déterminer les caractéristiques de la liaison et ont ensuite été analysés avec des outils de traitement développés sous Matlab. La seconde partie concerne l’analyse des variations rapides de polarisation à l’aide d’un polarimètre Agilent N7786B. Les paramètres de Stokes ont été mesurés avec un taux d’échantillonnage de 20 kHz durant 182 jours couvrant une période de 22 mois. La vitesse de rotation du vecteur de Stokes a été calculée pour l’ensemble des mesures et il a été possible d’étudier les changements rapides de polarisation sur l’ensemble des mesures à l’aide d’un outil développé sous Matlab. Une analyse harmonique des états de polarisation a été effectuée et enfin, une étude du bruit du polarimètre a été proposée au moyen d'un outil de simulation développé sous Matlab

Le spectromètre thermophorétique circulaire, un nouvel instrument pour mesurer la thermophorèse (application aux agrégats de suies de morphologie fractale)

Dans le but de montrer l influence de la morphologie fractale d un agrégat sur son comportement thermophorétique, un nouveau dispositif expérimental a été développé ; le SpectroMètreThermophorétique Circulaire (SMTC). Cet instrument permet de mesurer la vitesse moyenne de thermophorèse des particules dans une zone de sélection comprise entre une plaque chaude et une plaque froide. Pour cela, nous avons développé une fonction de transfert spécifique au principe de l instrument sur la base des travaux existant sur les analyseurs différentiels de mobilité électrique.Une qualification expérimentale du SMTC a été réalisée avec des billes de latex monodispersées de tailles comprises entre 64 nm et 500 nm. Le bon accord entre les vitesses de thermophorèse obtenues et la théorie de Beresnev et Chernyak (1995) nous a permis de valider le fonctionnement de l instrument.Par la suite, nous avons comparé les vitesses de thermophorèse expérimentales obtenues avec le SpectroMètre Thermophorétique Circulaire pour des particules sphériques et des agrégats produits par un générateur d aérosol à combustion. Contrairement aux résultats obtenus avec les billes de latex, nous observons une augmentation de la vitesse de thermophorèse des agrégats avec leur diamètre de mobilité électrique.Grâce à une étude morphologique des agrégats, nous avons remarqué que la vitesse de thermophorèse est dépendante du nombre de particules primaires de l agrégat. Ces résultats expérimentaux confirment pour la première fois les données théoriques de Mackowski (2006)obtenues par des simulations Monte-Carlo. De plus, une comparaison avec les travaux de Messerer et al. (2003) montre que la vitesse de thermophorèse des agrégats semble indépendante de la taille des particules primaires.In order to show the influence of the morphology of a fractal aggregate on its thermophoretic behavior, a new experimental device has been developed; the SpectroMètre ThermophorétiqueCirculaire (SMTC). This instrument is used to measure the mean thermophoretic velocity of particles selected between a hot plate and a cold plate thanks to a transfer function based on the geometry of the radial flow differential mobility analyser RF-DMA or SMEC (Spectromètre de Mobilité Electrique Circulaire). For the experimental validation, effective thermophoretic velocities of monodispersed spherical latex particles for diameters ranging from 64 nm to 500 nm and a temperature gradient equal to 50 750 K/m are measured and compared with theoretical values. The good agreement between the experimentals results and theoretical values of Beresnev and Chernyak (1995) helps us to validate the operation of the instrument.Then we compare experimental thermophoretic velocity obtained with the SMTC for spherical particles and aggregates produced by a combustion aerosol generator. Contrary to the results obtained with the PSL particles, we observe that the thermophoretic velocity of aggregates increases with the electrical mobility diameter. Thanks to a morphological study of the aggregates, we showed that the thermophoretic velocity depends on the number of primary particles of the aggregate. These experimental results confirm,for the first time, the theoretical data of Mackowski (2006) obtained by a Monte Carlo simulation. Moreover, a comparison with the experimental results of Messerer et al. (2003) shows that thethermophoretic velocity of aggregates seems independent of the primary particle size.ROUEN-INSA Madrillet (765752301) / SudocSudocFranceF

Characteristics of Positive Deviants in Western Chimpanzee Populations

With continued expansion of anthropogenically modified landscapes, the proximity between humans and wildlife is continuing to increase, frequently resulting in species decline. Occasionally however, species are able to persist and there is an increased interest in understanding such positive outliers and underlying mechanisms. Eventually, such insights can inform the design of effective conservation interventions by mimicking aspects of the social-ecological conditions found in areas of species persistence. Recently, frameworks have been developed to study the heterogeneity of species persistence across populations with a focus on positive outliers. Applications are still rare, and to our knowledge this is one of the first studies using this approach for terrestrial species conservation. We applied the positive deviance concept to the western chimpanzee, which occurs in a variety of social-ecological landscapes. It is now categorized as Critically Endangered due to hunting and habitat loss and resulting excessive decline of most of its populations. Here we are interested in understanding why some of the populations did not decline. We compiled a dataset of 17,109 chimpanzee survey transects (10,929 km) across nine countries and linked them to a range of social and ecological variables. We found that chimpanzees seemed to persist within three social-ecological configurations: first, rainforest habitats with a low degree of human impact, second, steep areas, and third, areas with high prevalence of hunting taboos and low degree of human impact. The largest chimpanzee populations are nowadays found under the third social-ecological configuration, even though most of these areas are not officially protected. Most commonly chimpanzee conservation has been based on exclusion of threats by creation of protected areas and law enforcement. Our findings suggest, however, that this approach should be complemented by an additional focus on threat reduction, i.e., interventions that directly target individual human behavior that is most threatening to chimpanzees, which is hunting. Although changing human behavior is difficult, stakeholder co-designed behavioral change approaches developed in the social sciences have been used successfully to promote pro-environmental behavior. With only a fraction of chimpanzees and primates living inside protected areas, such new approaches might be a way forward to improve primate conservation

Advancing conservation planning for western chimpanzees using IUCN SSC A.P.E.S.-the case of a taxon-specific database

Even though information on global biodiversity trends becomes increasingly available, large taxonomic and spatial data gaps persist at the scale relevant to planning conservation interventions. This is because data collectors are hesitant to share datawith global repositories due toworkload, lack of incentives, and perceived risk of losing intellectual property rights. In contrast, due to greater conceptual and methodological proximity, taxon-specific database initiatives can provide more direct benefits to data collectors through research collaborations and shared authorship.TheIUCNSSC Ape Populations, Environments and Surveys (A.P.E.S.) database was created in 2005 as a repository for data on great apes and other primate taxa. It aims to acquire field survey data and make different types of data accessible, and provide up-to-date species status information. To support the current update of the conservation action plan forwestern chimpanzees (Pan troglodytes verus) we compiled field surveys for this taxon from IUCNSSCA.P.E.S., 75%ofwhich were unpublished. We used spatial modeling to infer total population size, range-wide density distribution, population connectivity and landscape-scale metrics.Weestimated a total abundance of 52 800 (95%CI 17 577–96 564) western chimpanzees, of which only 17%occurred in national parks.We also found that 10%of chimpanzees live within 25 kmof fourmulti-national ‘development corridors’ currently planned forWestAfrica. These large infrastructure projects aim to promote economic integration and agriculture expansion, but are likely to cause further habitat loss and reduce population connectivity.We close by demonstrating the wealth of conservation-relevant information derivable from a taxon-specific database like IUCNSSC A.P.E.S. and propose that a network of many more such databases could be created to provide the essential information to conservation that can neither be supplied by one-off projects nor by global repositories, and thus are highly complementary to existing initiatives

A proteomic and phosphoproteomic analysis of Oryza sativa plasma membrane and vacuolar membrane

Proteomic and phosphoproteomic analyses of rice shoot and root tonoplast-enriched and plasma membrane-enriched membrane fractions were carried out to look at tissue-specific expression, and to identify putative regulatory sites of membrane transport proteins. Around 90 unique membrane proteins were identified, which included primary and secondary transporters, ion channels and aquaporins. Primary H+ pumps from the AHA family showed little isoform specificity in their tissue expression pattern, whereas specific isoforms of the Ca2+ pump ECA/ACA family were expressed in root and shoot tissues. Several ABC transporters were detected, particularly from the MDR and PDR subfamilies, which often showed expression in either roots or shoots. Ammonium transporters were expressed in root, but not shoot, tissue. Large numbers of sugar transporters were expressed, particularly in green tissue. The occurrence of phosphorylation sites in rice transporters such as AMT1;1 and PIP2;6 agrees with those previously described in other species, pointing to conserved regulatory mechanisms. New phosphosites were found in many transporters, including H+ pumps and H+:cation antiporters, often at residues that are well conserved across gene families. Comparison of root and shoot tissue showed that phosphorylation of AMT1;1 and several further transporters may be tissue dependent

The Critically Endangered western chimpanzee declines by 80%

African large mammals are under extreme pressure from unsustainable hunting and habitat loss. Certain traits make large mammals particularly vulnerable. These include late age at first reproduction, long inter-birth intervals, and low population density. Great apes are a prime example of such vulnerability, exhibiting all of these traits. Here we assess the rate of population change for the western chimpanzee, Pan troglodytes verus, over a 24-year period. As a proxy for change in abundance, we used transect nest count data from 20 different sites archived in the IUCN SSC A.P.E.S. database, representing 25,000 of the estimated remaining 35,000 western chimpanzees. For each of the 20 sites, datasets for 2 different years were available. We estimated site-specific and global population change using Generalized Linear Models. At 12 of these sites, we detected a significant negative trend. The estimated change in the subspecies abundance, as approximated by nest encounter rate, yielded a 6% annual decline and a total decline of 80.2% over the study period from 1990 to 2014. This also resulted in a reduced geographic range of 20% (657,600 vs. 524,100 km2). Poverty, civil conflict, disease pandemics, agriculture, extractive industries, infrastructure development, and lack of law enforcement, are some of the many reasons for the magnitude of threat. Our status update triggered the uplisting of the western chimpanzee to “Critically Endangered” on the IUCN Red List. In 2017, IUCN will start updating the 2003 Action Plan for western chimpanzees and will provide a consensus blueprint for what is needed to save this subspecies. We make a plea for greater commitment to conservation in West Africa across sectors. Needed especially is more robust engagement by national governments, integration of conservation priorities into the private sector and development planning across the region and sustained financial support from donors.Additional co-authors: Emma Normand, Kathryn Shutt-Phillips, Alexander Tickle, Elleni Vendras, Adam Welsh, Erin G. Wessling, Christophe Boesc

Diffuse panbronchiolitis: not just an Asian disease: Australian case series and review of the literature

Diffuse panbronchiolitis is a disease of obscure aetiology that is traditionally associated with Asian ethnicity. We propose that this disease also occurs in Caucasians and the incidence in this population is greater than currently recognised. We further propose that high resolution computed tomography (HRCT) and response to macrolide therapy should be relied upon to make this diagnosis without verification by lung biopsy. In most circumstances, obtaining a biopsy for histopathology is not practical, and the disease may then be mistaken for other more common airway diseases. Accuracy of diagnosis is important as untreated disease is associated with a poor prognosis, and effective treatment is available. We report four out of a series of cases as evidence that DPB is in fact more common in the Western population than is currently understood

Argonaute Autoantibodies as Biomarkers in Autoimmune Neurologic Diseases

OBJECTIVE: To identify and characterize autoantibodies (Abs) as novel biomarkers for an autoimmune context in patients with central and peripheral neurologic diseases. METHODS: Two distinct approaches (immunoprecipitation/mass spectrometry-based proteomics and protein microarrays) and patients' sera and CSF were used. The specificity of the identified target was confirmed by cell-based assay (CBA) in 856 control samples. RESULTS: Using the 2 methods as well as sera and CSF of patients with central and peripheral neurologic involvement, we identified Abs against the family of Argonaute proteins (mainly AGO1 and AGO2), which were already reported in systemic autoimmunity. AGO-Abs were mostly of immunoglobulin G 1 subclass and conformation dependent. Using CBA, AGO-Abs were detected in 21 patients with a high suspicion of autoimmune neurologic diseases (71.4% were women; median age 57 years) and only in 4/856 (0.5%) controls analyzed by CBA (1 diagnosed with small-cell lung cancer and the other 3 with Sjögren syndrome). Among the 21 neurologic patients identified, the main clinical presentations were sensory neuronopathy (8/21, 38.1%) and limbic encephalitis (6/21, 28.6%). Fourteen patients (66.7%) had autoimmune comorbidities and/or co-occurring Abs, whereas AGO-Abs were the only autoimmune biomarker for the remaining 7/21 (33.3%). Thirteen (61.9%) patients were treated with immunotherapy; 8/13 (61.5%) improved, and 3/13 (23.1%) remained stable, suggesting an efficacy of these treatments. CONCLUSIONS: AGO-Abs might be potential biomarkers of autoimmunity in patients with central and peripheral nonparaneoplastic neurologic diseases. In 7 patients, AGO-Abs were the only biomarkers; thus, their identification may be useful to suspect the autoimmune character of the neurologic disorder. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that AGO-Abs are more frequent in patients with autoimmune neurologic diseases than controls

Econometric analysis of continuous time models: A survey of Peter Phillips' work and some new results

Ministry of Education, Singapore under its Academic Research Funding Tier