Properties of seawater from a Sea-Bird TSG temperature and conductivity sensor mounted on the continuous surface water sampling system during campaign TARA_20100118Z of the Tara Oceans expedition 2009-2013

The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data publication contains measurements from the Continuous Surface Sampling System [CSSS] made during one campaign of the Tara Oceans Expedition. Water was pumped at the front of the vessel from ~2m depth, then de-bubbled and circulated to a Sea-Bird TSG temperature and conductivity sensor. System maintenance (instrument cleaning, flushing) was done approximately once a week and in port between successive legs. All data were stamped with a GPS.

Properties of seawater from a Sea-Bird TSG temperature and conductivity sensor mounted on the continuous surface water sampling system during campaign TARA_20100309Z of the Tara Oceans expedition 2009-2013

The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data publication contains measurements from the Continuous Surface Sampling System [CSSS] made during one campaign of the Tara Oceans Expedition. Water was pumped at the front of the vessel from ~2m depth, then de-bubbled and circulated to a Sea-Bird TSG temperature and conductivity sensor. System maintenance (instrument cleaning, flushing) was done approximately once a week and in port between successive legs. All data were stamped with a GPS.

Properties of seawater from a Sea-Bird TSG temperature and conductivity sensor mounted on the continuous surface water sampling system during campaign TARA_20100508Z of the Tara Oceans expedition 2009-2013

The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data publication contains measurements from the Continuous Surface Sampling System [CSSS] made during one campaign of the Tara Oceans Expedition. Water was pumped at the front of the vessel from ~2m depth, then de-bubbled and circulated to a Sea-Bird TSG temperature and conductivity sensor. System maintenance (instrument cleaning, flushing) was done approximately once a week and in port between successive legs. All data were stamped with a GPS.

Properties of seawater from a Sea-Bird TSG temperature and conductivity sensor mounted on the continuous surface water sampling system during campaign TARA_20110501Z of the Tara Oceans expedition 2009-2013

The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data publication contains measurements from the Continuous Surface Sampling System [CSSS] made during one campaign of the Tara Oceans Expedition. Water was pumped at the front of the vessel from ~2m depth, then de-bubbled and circulated to a Sea-Bird TSG temperature and conductivity sensor. System maintenance (instrument cleaning, flushing) was done approximately once a week and in port between successive legs. All data were stamped with a GPS.

Properties of seawater from a Sea-Bird TSG temperature and conductivity sensor mounted on the continuous surface water sampling system during campaign TARA_20110520Z of the Tara Oceans expedition 2009-2013

The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data publication contains measurements from the Continuous Surface Sampling System [CSSS] made during one campaign of the Tara Oceans Expedition. Water was pumped at the front of the vessel from ~2m depth, then de-bubbled and circulated to a Sea-Bird TSG temperature and conductivity sensor. System maintenance (instrument cleaning, flushing) was done approximately once a week and in port between successive legs. All data were stamped with a GPS.

Properties of seawater from a Sea-Bird TSG temperature and conductivity sensor mounted on the continuous surface water sampling system during campaign TARA_20110716Z of the Tara Oceans expedition 2009-2013

The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data publication contains measurements from the Continuous Surface Sampling System [CSSS] made during one campaign of the Tara Oceans Expedition. Water was pumped at the front of the vessel from ~2m depth, then de-bubbled and circulated to a Sea-Bird TSG temperature and conductivity sensor. System maintenance (instrument cleaning, flushing) was done approximately once a week and in port between successive legs. All data were stamped with a GPS.

Properties of seawater from a Sea-Bird TSG temperature and conductivity sensor mounted on the continuous surface water sampling system during campaign TARA_20110826Z of the Tara Oceans expedition 2009-2013

The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data publication contains measurements from the Continuous Surface Sampling System [CSSS] made during one campaign of the Tara Oceans Expedition. Water was pumped at the front of the vessel from ~2m depth, then de-bubbled and circulated to a Sea-Bird TSG temperature and conductivity sensor. System maintenance (instrument cleaning, flushing) was done approximately once a week and in port between successive legs. All data were stamped with a GPS.

Experimental investigation of water, snow and granular ice effects on ice failure processes and impact loads

A large series of laboratory ice crushing experiments was performed to investigate the effects of external boundary condition and indenter contact geometry on ice load magnitude under crushing conditions. Four boundary conditions were considered: dry cases, submerged cases, and cases with the presence of snow and granular ice material on the indenter surface. Indenter geometries were a flat plate, wedge shaped indenter, (reverse) conical indenter, and spherical indenter. These were impacted with artificially produced ice specimens of conical shape with 20° and 30° cone angles. All indenter – ice combinations were tested in dry and submerged environments at 1 mm/s and 100 mm/s indentation rates. Additional tests with the flat indentation plate were conducted at 10 mm/s impact velocity and a subset of scenarios with snow and granular ice material was evaluated. The tests were performed using a material testing system (MTS) machine located inside a cold room at an ambient temperature of - 7°C. Data acquisition comprised time, vertical force, and displacement. In several tests with the flat plate and wedge shaped indenter, supplementary information on local pressure patterns and contact area were obtained using tactile pressure sensors. All tests were recorded with a high speed video camera and still photos were taken before and after each test. Thin sections were taken of some specimens as well. Ice loads were found to strongly depend on contact condition, interrelated with pre-existing confinement and indentation rate. Submergence yielded higher forces, especially at the high indentation rate. This was very evident for the flat indentation plate and spherical indenter, and with restrictions for the wedge shaped indenter. No indication was found for the conical indenter. For the conical indenter it was concluded that the structural restriction due to the indenter geometry was dominating. The working surface for the water to act was not sufficient to influence the failure processes and associated ice loads. The presence of snow and granular ice significantly increased the forces at the low indentation rate (with the flat indentation plate) that were higher compared to submerged cases and far above the dry contact condition. Contact area measurements revealed a correlation of higher forces with a concurrent increase in actual contact area that depended on the respective boundary condition. In submergence, ice debris constitution was changed; ice extrusion, as well as crack development and propagation were impeded. Snow and granular ice seemed to provide additional material sources for establishing larger contact areas. The dry contact condition generally had the smallest real contact area, as well as the lowest forces. The comparison of nominal and measured contact areas revealed distinct deviations. The incorporation of those differences in contact process pressures-area relationships indicated that the overall process pressure was not substantially affected by the increased loads.

Positionality and Comparisons: Critical Views on Qualitative Research across Asia

Ce cahier est basé sur la réflexion autobiographique de deux chercheuses ayant effectué des recherches qualitatives et ethnographiques, de 2008 à 2014, en Asie centrale et du Sud-­‐Est. Les expériences sur le terrain constituent des moyens de comparaisons dans le présent document. En mettant l’accent sur le positionnement sur le terrain, l’étude montre que, d’abord, il est essentiel de détenir une poste intermédiaire et de parler une langue locale afin de garantir un accès et de mener des activités de recherche sur le terrain. Deuxièmement, différentes régions prédéterminent des contextes culturels et politiques ponctuels qui, à leur tour, façonneraient la recherche en sciences sociales. Troisièmement, le fait d’être une femme présente à la fois des avantages et des inconvénients. Enfin, en termes de méthodologie, les stages et les entrevues se sont avérés des méthodes fiables pour la collecte des données empiriques sur les régions ci-­‐dessus mentionnées, sans pour autant permettre de bâtir la confiance.

An investigation of the molecular interactions between statins and bacterial pathogens, and their combined impact on the human immune system

Statins are a class of drug that inhibits cholesterol biosynthesis, and are used to treat patients with high serum cholesterol levels. They exert this function by competitively binding to the enzyme 3-hydroxy-3-methylglutaryl-CoenzymeA reductase (HMGR), which catalyses the formation of mevalonate, a rate-limiting step in cholesterol biosynthesis. In addition, statins have what are called “pleiotropic effects”, which include the reduction of inflammation, immunomodulation, and antimicrobial effects. Statins can also improve survival of patients with sepsis and pneumonia. Cystic fibrosis (CF) is the most common recessive inherited disease in the Caucasian population, which is characterised by factors including, but not limited to, excessive lung inflammation and increased susceptibility to infection. Therefore, the overall objective of this study was to examine the effects of statins on CFassociated bacterial pathogens and the host response. In this work, the prevalence of HMGR was examined in respiratory pathogens, and several CF-associated pathogens were found to possess homologues of this enzyme. HMGR homology was analysed in Staphylococcus aureus, Burkholderia cenocepacia and Streptococcus pneumoniae, and the HMGR of B. cenocepacia was found to have significant conservation to that of Pseudomonas mevalonii, which is the most widely-characterised bacterial HMGR. However, in silico analysis revealed that, unlike S. aureus and S. pneumoniae, B. cenocepacia did not possess homologues of other mevalonate pathway proteins, and that the HMGR of B. cenocepacia appeared to be involved in an alternative metabolic pathway. The effect of simvastatin was subsequently tested on the growth and virulence of S. aureus, B. cenocepacia and S. pneumoniae. Simvastatin inhibited the growth of all 3 species in a dose-dependent manner. In addition, statin treatment also attenuated biofilm formation of all 3 species, and reduced in vitro motility of S. aureus. Interestingly, simvastatin also increased the potency of the aminoglycoside antibiotic gentamicin against B. cenocepacia. The impact of statins was subsequently tested on the predominant CF-associated pathogen Pseudomonas aeruginosa, which does not possess a HMGR homologue. Mevastatin, lovastatin and simvastatin did not influence the growth of this species. However, sub-inhibitory statin concentrations reduced the swarming motility and biofilm formation of P. aeruginosa. The influence of statins was also examined on Type 3 toxin secretion, quorum sensing and chemotaxis, and no statin effect was observed on any of these phenotypes. Statins did not appear to have a characteristic effect on the P. aeruginosa transcriptome. However, a mutant library screen revealed that the effect of statins on P. aeruginosa biofilm was mediated through the PvrR regulator and the Cup fimbrial biosynthesis genes. Furthermore, proteomic analysis demonstrated that 6 proteins were reproducibly induced by simvastatin in the P. aeruginosa swarming cells. The effect of statins on the regulation of the host-P. aeruginosa immune response was also investigated. Statin treatment increased expression of the pro-inflammatory cytokines IL-8 and CCL20 in lung epithelial cells, but did not attenuate P. aeruginosa-mediated inflammatory gene induction. In fact, simvastatin and P. aeruginosa caused a synergistic effect on CCL20 expression. The expression of the transcriptional regulators KLF2 and KLF6 was also increased by statins and P. aeruginosa, with the induction of KLF6 by simvastatin proving to be a novel effect. Interestingly, both statins and P. aeruginosa were capable of inducing alternative splicing of KLF6. P. aeruginosa was found to induce KLF6 alternative splicing by way of the type 3 secreted toxin ExoS. In addition, a mechanistic role was elucidated for KLF6 in the lung, as it was determined that statin-mediated induction of this protein was responsible for the induction of the host response genes CCL20 and iNOS. Moreover, statin treatment caused a slight increase in infection-related cytotoxicity, and increased bacterial adhesion to cells. Taken together, these data demonstrate that statins can reduce the virulence of CFassociated bacterial pathogens and alter host response effectors. Furthermore, novel statin effectors were identified in both bacterial and host cells.

Analytic Torsion, the Eta Invariant, and Closed Differential Forms on Spaces of Metrics

The central idea of this dissertation is to interpret certain invariants constructed from Laplace spectral data on a compact Riemannian manifold as regularized integrals of closed differential forms on the space of Riemannian metrics, or more generally on a space of metrics on a vector bundle. We apply this idea to both the Ray-Singer analytic torsion

and the eta invariant, explaining their dependence on the metric used to define them with a Stokes' theorem argument. We also introduce analytic multi-torsion, a generalization of analytic torsion, in the context of certain manifolds with local product structure; we prove that it is metric independent in a suitable sense.

Positionality and Comparisons: Critical Views on Qualitative Research across Asia

Ce cahier est basé sur la réflexion autobiographique de deux chercheuses ayant effectué des recherches qualitatives et ethnographiques, de 2008 à 2014, en Asie centrale et du Sud-­‐Est. Les expériences sur le terrain constituent des moyens de comparaisons dans le présent document. En mettant l’accent sur le positionnement sur le terrain, l’étude montre que, d’abord, il est essentiel de détenir une poste intermédiaire et de parler une langue locale afin de garantir un accès et de mener des activités de recherche sur le terrain. Deuxièmement, différentes régions prédéterminent des contextes culturels et politiques ponctuels qui, à leur tour, façonneraient la recherche en sciences sociales. Troisièmement, le fait d’être une femme présente à la fois des avantages et des inconvénients. Enfin, en termes de méthodologie, les stages et les entrevues se sont avérés des méthodes fiables pour la collecte des données empiriques sur les régions ci-­‐dessus mentionnées, sans pour autant permettre de bâtir la confiance.