43 research outputs found
Multimodal Mental Health Analysis in Social Media
Depression is a major public health concern in the U.S. and globally. While successful early identification and treatment can lead to many positive health and behavioral outcomes, depression, remains undiagnosed, untreated or undertreated due to several reasons, including denial of the illness as well as cultural and social stigma. With the ubiquity of social media platforms, millions of people are now sharing their online persona by expressing their thoughts, moods, emotions, and even their daily struggles with mental health on social media. Unlike traditional observational cohort studies conducted through questionnaires and self-reported surveys, we explore the reliable detection of depressive symptoms from tweets obtained, unobtrusively. Particularly, we examine and exploit multimodal big (social) data to discern depressive behaviors using a wide variety of features including individual-level demographics. By developing a multimodal framework and employing statistical techniques to fuse heterogeneous sets of features obtained through the processing of visual, textual, and user interaction data, we significantly enhance the current state-of-the-art approaches for identifying depressed individuals on Twitter (improving the average F1-Score by 5 percent) as well as facilitate demographic inferences from social media. Besides providing insights into the relationship between demographics and mental health, our research assists in the design of a new breed of demographic-aware health interventions
A Tethered Bilayer Assembled on Top of Immobilized Calmodulin to Mimic Cellular Compartmentalization
International audienceBACKGROUND: Biomimetic membrane models tethered on solid supports are important tools for membrane protein biochemistry and biotechnology. The supported membrane systems described up to now are composed of a lipid bilayer tethered or not to a surface separating two compartments: a "trans" side, one to a few nanometer thick, located between the supporting surface and the membrane; and a "cis" side, above the synthetic membrane, exposed to the bulk medium. We describe here a novel biomimetic design composed of a tethered bilayer membrane that is assembled over a surface derivatized with a specific intracellular protein marker. This multilayered biomimetic assembly exhibits the fundamental characteristics of an authentic biological membrane in creating a continuous yet fluid phospholipidic barrier between two distinct compartments: a "cis" side corresponding to the extracellular milieu and a "trans" side marked by a key cytosolic signaling protein, calmodulin. METHODOLOGY/PRINCIPAL FINDINGS: We established and validated the experimental conditions to construct a multilayered structure consisting in a planar tethered bilayer assembled over a surface derivatized with calmodulin. We demonstrated the following: (i) the grafted calmodulin molecules (in trans side) were fully functional in binding and activating a calmodulin-dependent enzyme, the adenylate cyclase from Bordetella pertussis; and (ii) the assembled bilayer formed a continuous, protein-impermeable boundary that fully separated the underlying calmodulin (trans side) from the above medium (cis side). CONCLUSIONS: The simplicity and robustness of the tethered bilayer structure described here should facilitate the elaboration of biomimetic membrane models incorporating membrane embedded proteins and key cytoplasmic constituents. Such biomimetic structures will also be an attractive tool to study translocation across biological membranes of proteins or other macromolecules
Synthèses, caractérisations structurales et physico-chimiques de nouveaux fluorures de zirconium, de terbium et de thorium tétravalent
Une étude du système ternaire KF-CaF2-TbF4 a permis de mettre en évidence deux nouveaux fluorures de formules KCaTbF7 et K2CaTb2F12. Parallèlement une série de fluorures homologues de formule ABMF7 (A=K, Rb, Tl, Cs ; B=Ca, Cd ; M=Zr, Hf, Tb) a été révélée. Le composé KCaTbF7 dont la structure cristalline a été déterminée à partir du rayonnement synchrotron constitue le premier exemple de fluorure dans lequel l'ion Tb4+ adopte une vraie coordinence 7. L'étude magnétique réalisée pour le composé K2CaTb2F12 a révélé une structure antiferromagnétique colinéaire. Un comportement métamagnétique a été observé à très basse température et des interactions de superéchange ont été mises en évidence au sein de ce composé. L'étude structurale par DRX sur monocristal et diffraction neutronique du composé à valence mixte RbTb6F24 a révélé une distribution statistique des ions Tb3+ et Tb4+ sur un site cristallographique unique de coordinence 8 ou 9. Enfin l'étude structurale du composé TlThF6 à partir des données de la DRX sur monocristal a révélé un type structural très complexe et très différent de ceux généralement observés pour les fluorures de formule générale A2MF6CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF
Characterization and photooxidative behaviour of nanocomposites formed with polystyrene and LDHs organo-modified by monomer surfactant.
Editeur ElsevierLayered double hydroxide (LDH) organo-modified by a surface-active monomer, 3-sulfopropyl methacrylate (SPMA) was used as filler for polystyrene (PS). DifFerent nanocomposites SPMA/LDH:PS were prepared by bulk polymerization process using low amount of initiator. The two components, filler and polymer, as well as the degree dispersion of the reactive filler as a function of ils loading in PS were characterized by a combination of several techniques: X-ray diffraction, high resolution t3C CP-MAS NMR, 1-TIR, UV-visible, thermal analysis, SEC and MET. The nanocomposites were submitted to UV-light exposures in the presence of oxygen. The oxidation photoproducts and the rates of oxidation were compared for the varions samples. It was shown that the filler was not modifying the oxidation mechanism of the polymer, but had a slight effect on the oxidation rate
Development and implementation of an in vitro culture system for intact detached grape berries
Grape composition depends on the metabolites accumulated and synthesized during grape development. It is of paramount importance for grape growers because of its major role in shaping wine quality. Therefore, understanding the regulation mechanisms that control the accumulation of quality-related metabolites in grape is of both scientific and agronomical interests. The composition of grape berry at harvest is under complex regulation and can be affected by many factors (Conde et al., 2007). The study of the effects of these factors on berries still attached to intact plants can be highly challenging because of the large size of the plants, interplant, intercluster and interberry variability; and because it is complicated to precisely control the nutrients and hormones imported by the berries, and the environment. Therefore, in vitro cultured grape berries are a good model system, which better represents berry anatomy structure (skin and flesh) than grape cell suspensions and nevertheless largely reduces the system complexity compared to whole plant (Bravdo et al., 1990; Pérez et al., 2000; Gambetta et al., 2010). To this end, an in vitro culture system of intact detached grape berries has been developed by coupling greenhouse fruiting-cuttings production and in vitro organ culture techniques (Dai et al., 2014). The cultured berries are able to actively absorb and utilize carbon and nitrogen from the culture medium, and exhibit fruit ripening features such as color changing and softening. This in vitro system may serve to investigate the response of berry composition to environmental and nutrient factors
N2 New Orleans Retention Study: Final Report
From August 2019 through February 2020, a total of 165 cisgender Black/African American gay and bisexual men were recruited to the ‘Neighborhoods and Networks’ (N2) cohort study in New Orleans, Louisiana (NOLA). Subsequent waves of data collection were interrupted by the COVID-19 pandemic, which necessitated temporary discontinuation of the study protocol. To assess the feasibility of future longitudinal research carried out with Black gay and bisexual men in NOLA, in May 2021 a small study focused on retention was carried out with existing N2 participants. </div
Enhanced photocatalytic degradation of cationic dyes under visible light irradiation by CuWO4-RGO nanocomposite
Dielectric study of unexpected transitions in multiferroic Mn1-x(Mg,Zn)xWO4 ceramics
The influence of magnetic field on the dielectric properties of several Mn1-x(Mg,Zn)xWO4 multiferroic ceramics is investigated, and confirms an additional phase transition below the ferroelectric Curie temperature previously detected in this system in zero magnetic field. In highly doped samples an original plateau of the capacitance is observed between T2 and this additional transition. Pyroelectric measurements in zero magnetic field for a Mn0.85Mg0.15WO4 ceramic confirm the existence of this unexpected low temperature phase transition. The magnetic or structural origin of this transition is discussed