Membrane assembly and ion transport ability of a fluorinated nanopore

A novel 21-residue peptide incorporating six fluorinated amino acids was prepared. It was designed to fold into an amphiphilic alpha helical structure of nanoscale length with one hydrophobic face and one fluorinated face. The formation of a fluorous interface serves as the main vector for the formation of a superstructure in a bilayer membrane. Fluorescence assays showed this ion channel's ability to facilitate the translocation of alkali metal ions through a phospholipid membrane, with selectivity for sodium ions. Computational studies showed that a tetramer structure is the most probable and stable supramolecular assembly for the active ion channel structure. The results illustrate the possibility of exploiting multiple Fd-:M+ interactions for ion transport and using fluorous interfaces to create functional nanostructures

Étude du choix de localisation des immigrants au Canada

Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2008-2009Depuis plusieurs années l'immigration est confrontée à une forte concentration géographique des nouveaux immigrants. En 2001, ce sont plus de 70% de ces immigrants qui ont choisi de s'établir dans l'une des trois grandes rnétropoles canadiennes que sont Toronto, Vancouver et Montréal. Cette concentration géographique s'avère à plusieurs égards problématique. Afin de résoudre ce problèrne, l'objectif de ce mémoire consiste à étudier les déterminants affectant le choix de localisation initiale des nouveaux immigrants au Canada. Nous procédons à l'estimation à l'aide d'un modèle de choix discret de type logit conditionnel et notre ensemble de choix est constitué des 15 principales régions métropolitaines de recensement (rmr). Pour effectuer cette étude, nous avons recours à l'enquête longitudinale auprès des immigrants du Canada de Stat istique Canada (ELIC). Les informations contenues dans cette base de données étant extrêmement riches, elles nous perrnettent de nous distinguer à plusieurs égards des études antérieures. Nos estimations démontrent notamment que la taille de la communauté provenant du pays d 'origine de l 'immigrant ainsi que la proximité des membres de sa famille sont des déterminants influents dans un choix de localisation initiale. Le système de sélection des immigrants économiques, créé en 1967, constitue également un élément central de notre étude. Nous vérifions notamment si les immigrants possédant les critères compris dans ce système de sélection sont plus susceptibles de s'établir à l'extérieur des trois grandes métropoles. Nous constatons entre autres que les immigrants de la catégorie économique ayant déjà véçu au Canada avant d'y immigrer ainsi que ceux maîtrisant bien la langue d'accueil s'avèrent en général moins susceptibles de s'établir dans l'une des trois grandes métropoles. En revanche, bien qu'accordant moins d'importance à la taille de la communauté provenant de leur pays d'origine, les immigrants détenant un diplôrne universitaire ont une probabilité plus forte de se diriger vers l'une des grandes métropoles

Demand for Manufacturing Imports in China

Fluctuations in Chinese imports are often viewed by analysts as containing information about domestic demand in China. However, identifying the extent to which imports of manufactured goods depend on domestic demand is difficult given the integration of Chinese trade in regional manufacturing supply networks. This article analyses Chinese imports of manufactured goods and assesses whether the determinants of manufactured goods imports have changed over the past few years. Over time, imports have declined as a share of Chinese sales of manufactured goods and appear to have become less affected by domestic demand and instead become more sensitive to exports

Stuck in a lockdown: dreams, bad dreams, nightmares, and their relationship to stress, depression and anxiety during the COVID-19 pandemic

Background: An upsurge in dream and nightmare frequency has been noted since the beginning of the COVID-19 pandemic and research shows increases in levels of stress, depression and anxiety during this time. Growing evidence suggests that dream content has a bi-directional relationship with psychopathology, and that dreams react to new, personally significant and emotional experiences. The first lockdown experience was an acute event, characterized by a combination of several unprecedented factors (new pandemic, threat of the disease, global uncertainty, , experience of social isolation, exposure to stressful information) that resulted in a large-scale disruption of life routines. This study aimed at investigating changes in dream, bad dream and nightmare recall; most prevalent dream themes, and the relationship between dreams, bad dreams, nightmares and symptoms of stress, depression and anxiety during the first COVID-19 lockdown (April-May 2020) through a national online survey. Methods: 968 participants completed an online survey. Dream themes were measured using the Typical Dreams Questionnaire; stress levels were measured by the Cohen’s Perceived Stress Scale; symptoms of anxiety were assessed by Generalized Anxiety Disorder (GAD-7) scale; and symptoms of depression were assessed using the Quick Inventory of Depressive Symptomatology. Results: 34% (328) of participants reported increased dream recall during the lockdown. The most common dream themes were centered around the topics of 1) inefficacy (e.g., trying again and again, arriving late), 2) human threat (e.g., being chased, attacked); 3) death; and 4) pandemic imagery (e.g., being separated from loved ones, being sick). Dream, bad dream and nightmare frequency was highest in individuals with moderate to severe stress levels. Frequency of bad dreams nightmares and dreams about the pandemic, inefficacy and death were associated with higher levels of stress, as well as with greater symptoms of depression and anxiety. Conclusions: Results support theories of dream formation, environmental susceptibility and stress reactivity. Dream content during the lockdown broadly reflected existential concerns and was associated with increased symptoms of mental health indices

Superstructure stability (top row) and typical equilibrated structures (bottom row) of the LX2 trimer, tetramer, pentamer and hexamer.

<p>Surrounding lipids are not shown for clarity. The pentamer and hexamer starting structures are not completely symmetric following energy minimization. Internal diameters (I.D.) are averaged values along the complete pore lumen. The color code is the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166587#pone.0166587.g005" target="_blank">Fig 5</a>.</p

Averages of the fluorine-fluorine surface of contact in Ų.

<p>Averages of the fluorine-fluorine surface of contact in Ų.</p

Mass spectrum of LX2 obtained using MALDI mass spectrometry.

<p>Mass spectrum of LX2 obtained using MALDI mass spectrometry.</p