Effects of population density on the sediment mixing induced by the gallery-diffusor Hediste (Nereis) diversicolor O.F. Müller, 1776

The aim of this work was to quantify the intensity of sediment mixing induced by the gallery-diffusor (functional bioturbation group) Hediste diversicolor as a function of density, using particles tracers (luminophores). In order to assess the impact of density on sediment reworking, a 1-D model was used to obtain sediment reworking coefficients such as Db (biodiffusion-like) and r (biotransport). Densities used in this experiment corresponded to population densities observed in the sampling area (Saint-Antoine Canal, Gulf of Fos, France): 144, 288, 577, 1153 indiv/m2. At first, results showed that neither luminophore maximum burying depth nor the more marked tracer accumulation areas were influenced by density. Thus density did not seem to have any influence on size of galleries or complexity of structure. Then, density-dependent relations with Db (biodiffusion-like mixing) and r (biotransport) were highlighted with an observed process intensity rate twice as high at highest worm density. On the other hand, Db and r per capita coefficients were negatively influenced by density. Db and r per capita at highest density were equal to ∼20% of individual Db and r obtained at the lowest density. Finally, this study showed the importance of density which appears to be a key parameter in the functioning of the sedimentary ecosystem

Modular Design of Physical Internet Transport, Handling and Packaging Containers

This paper proposes a three‐tier characterization of Physical Internet containers into transport, handling and packaging containers. It first provides an overview of goods encapsulation in the Physical Internet and of the generic characteristics of Physical Internet containers. Then it proceeds with an analysis of the current goods encapsulation practices. This leads to the introduction of the three tiers, with explicit description and analysis of containers of each tier. The paper provides a synthesis of the proposed transformation of goods encapsulation and highlights key research and innovation opportunities and challenges for both industry and academia

Ontogénèse et mécanismes de régulation de la synthèse de la lipase dans l'estomac humain

L'objectif global du présent travail était d'identifier des modulateurs et d'établir leurs mécanismes de régulation, tant au niveau cellulaire que moléculaire, du développement fonctionnel de la muqueuse gastrique foetale humaine, et en ce qui a trait plus particulièrement à la lipase gastrique. En effet, dès la naissance la lipase gastrique joue un rôle primordial dans la digestion des lipides, et ce dûe à l'absence de la lipase pancréatique. Dans un premier temps, nous avons analysé le patron de distribution de la lipase gastrique dans les différentes régions anatomiques de l'estomac au cours du développement. Nous avons mis en évidence que le patron de distribution de l'enzyme que l'on retrouve chez l'adulte est déjà établi à la 13ème semaine de gestation dans la muqueuse gastrique foetale. Cet [i.e. Cette] apparition précoce ainsi que ce patron d'expression adulte de la lipase supportent l'hypothèse de son rôle nutritionnel important à la naissance. De plus, nous avons montré que la lipase est localisée dans les granules de sécrétion des cellules principales de l'épithélium gastrique en développement. Dans un second volet, nous avons établi la capacité de facteur de croissance épidermique (EGF) à moduler le développement de la muqueuse gastrique humaine. Nos résultats ont démontré que EGF module la prolifération cellulaire de l'épithélium gastrique ainsi que la synthèse des glycoprotéines et l'activité de la lipase. De plus, nous avons révélé que les effets de ce facteur de croissance sont médiés par la présence d'un récepteur spécifique à EGF localisé à la membrane basolatérale des cellules épithéliales. Par conséquent, ces observations ont montré que EGF est un modulateur important du développement fonctionnel de la muqueuse gastrique humaine. Dans un troisième volet, nous nous sommes intéressés à l'insuline et aux facteurs de croissance insuliniques (IGFs) sur la modulation du développement de l'estomac. Nous avons observé la présence de récepteurs spécifiques à IGF-1 et à l'insuline qui sont localisés dans la portion basolatérale des cellules épithéliales gastriques. Nous avons établi que les IGFs, mais non l'insuline, influencent le développement de la muqueuse gastrique. En effet, nous avons constaté que les IGFs modulent de façon similaire la lipase gastrique mais que seul IGF-1 stimule la prolifération cellulaire. Par ailleurs, nous avons démontré que la muqueuse gastrique foetale humaine est une source endogène de IGFBPs (Insulin-like Growth Factor Binding Proteins), et qu'elles possèdent la capacité de lier les IGFs, indiquant la possibilité d'interactions entre les IGFBPs et les IGFs dans la modulation du développement de la muqueuse gastrique

Sulfur Dioxide and Emergency Department Visits for Stroke and Seizure

The purpose of this study was to assess an association between ambient sulfur dioxide and the number of emergency department (ED) visits for ischemic stroke and seizure. The study used data collected in a Vancouver (Canada) hospital in the years 1999–2003. Daily ED visits diagnosed as ministroke, stroke, or seizure were investigated using the case-crossover technique. Conditional logistic regression models were applied to estimate the odds ratios (ORs) and their respective 95% confidence intervals (CIs). The models included temperature and relative humidity in the form of natural splines. The results were reported for an increase in interquartile range ((IQR), IQR = 1.9 ppb for SO2). Positive and statistically significant associations were obtained for SO2 and ischemic stroke for all patients (OR = 1.12; CI 1.02, 1.23; lag 3) and for female patients (OR = 1.17; CI 1.01, 1.33; lag 0). In the case of ED visits for seizure, for female patients the results were also statistically significant (OR = 1.15; CI 1.02, 1.28; lag 1 and OR = 1.18; CI 1.05, 1.32; lag 2). These findings suggest that cases of ischemic cerebrovascular accidents are associated with acute exposure to ambient sulfur dioxide

Nutrients vs. turbulence, and the future of Arctic Ocean primary production

Poster no. B7 from Forum for Arctic Modeling & Observational Synthesis (Woods Hole Oceanographic Institution, 2-4 November 2016.This poster presents estimates of nitrate fluxes in the Arctic Ocean and speculates on the associated primary production in a future climate

Wind-driven upwelling around grounded tabular icebergs

Funding was provided by NSF Polar Programs - Grant Number: ARC-1304137.Temperature and salinity data collected around grounded tabular icebergs in Baffin Bay in 2011, 2012 and 2013 indicate wind-induced upwelling at certain locations around the icebergs. These data suggest that along one side of the iceberg, wind forcing leads to Ekman transport away from the iceberg, which causes upwelling of the cool saline water from below. The upwelling water mixes with the water in the thermocline, causing the mixed layer to become cooler and more saline. Along the opposite side of the iceberg, the surface Ekman transport moves towards the iceberg, which causes a sharpening of the thermocline as warm fresh water is trapped near the surface. This results in higher mixed layer temperatures and lower mixed layer salinities on this side of the iceberg. Based on these in situ measurements, we hypothesize that the asymmetries in water properties around the iceberg, caused by the opposing effects of upwelling and sharpening of the thermocline, lead to differential deterioration around the iceberg. Analysis of satellite imagery around iceberg PII-B-1 over a six month monitoring period reveals differential decay around the iceberg, in agreement with this mechanism.Publisher PDFPeer reviewe

HST/ACS Emission Line Imaging of Low Redshift 3CR Radio Galaxies I: The Data

We present 19 nearby (z<0.3) 3CR radio galaxies imaged at low- and high-excitation as part of a Cycle 15 Hubble Space Telescope snapshot survey with the Advanced Camera for Surveys. These images consist of exposures of the H-alpha (6563 \AA, plus [NII] contamination) and [OIII] 5007 \AA emission lines using narrow-band linear ramp filters adjusted according to the redshift of the target. To facilitate continuum subtraction, a single-pointing 60 s line-free exposure was taken with a medium-band filter appropriate for the target's redshift. We discuss the steps taken to reduce these images independently of the automated recalibration pipeline so as to use more recent ACS flat-field data as well as to better reject cosmic rays. We describe the method used to produce continuum-free (pure line-emission) images, and present these images along with qualitative descriptions of the narrow-line region morphologies we observe. We present H-alpha+[NII] and [OIII] line fluxes from aperture photometry, finding the values to fall expectedly on the redshift-luminosity trend from a past HST/WFPC2 emission line study of a larger, generally higher redshift subset of the 3CR. We also find expected trends between emission line luminosity and total radio power, as well as a positive correlation between the size of the emission line region and redshift. We discuss the associated interpretation of these results, and conclude with a summary of future work enabled by this dataset.Comment: 18 pages, 12 figures, accepted for publication in ApJ