Naturism and the paradoxes of identity in contemporary society

Orientador: Mariza CorrêaTese (doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciências HumanasResumo: A pesquisa desenvolvida nesta tese de doutoramento tem como eixo central o estudo do naturismo, atividade em que a nudez do corpo é exposta em espaços públicos. Nesta, são discutidos os aspectos centrais que sustentam a perspectiva do processo de construção de identidades relativa ao fenômeno. O naturismo pode ser interpretado como derivado de uma sociedade que, por um lado, cultua o corpo e o poder da sua imagem e, por outro, atribui ao lazer uma função decisiva na promoção de uma ação social ligada a preceitos morais. Como o corpo humano serve de símbolo de pertencimento, investigam-se as dimensões intrínsecas das relações entre os praticantes, tendo sempre em vista a contraposição à ênfase que os grupos naturistas colocam na "pureza" e o "igualitarismo" dos corpos nus. Utilizando a Associação Naturista de Abricó (ANA) do município do Rio de Janeiro (RJ) como objeto de pesquisa, baseia sua investigação na problematização do paradoxo que se inscreve no "respeito" obtido e exigido através da nudez comunalAbstract: The research developed in this doctoral thesis is a study on the central axis of naturism, activity in which the body is exposed naked in public spaces. We discuss the key aspects that support the viewpoint of the construction of identities related to the phenomenon. Naturism can be interpreted as derived from a society that on the one hand, worships the body and the power of its image and, second, gives leisure a decisive role in promoting social action linked to moral precepts. As the human body serves as a symbol of belonging, the intrinsic dimensions of relations among practitioners is investigated, always bearing in mind the opposition emphasized by naturist groups between "purity" and "egalitarianism" of naked bodies. Using Abricó Naturist Association (ANA) in the municipality of Rio de Janeiro (RJ) as a research subject, this research analyses the paradox that is part of the "respect" demanded and obtained through communal nudityDoutoradoCiencias SociaisDoutor em Ciências Sociai

Photoinitiated Intramolecular Proton Transfer in Deprotonated para-Coumaric Acid

Deprotonated para-coumaric acid is commonly considered as a model for the chromophore in photoactive yellow protein, which undergoes E → Z isomerization following absorption of blue light. Here, tandem ion mobility mass spectrometry is coupled with laser excitation to study the photochemistry of deprotonated para-coumaric acid, to show that the E isomers of the phenoxide and carboxylate forms have distinct photochemical responses with maxima in their action spectra at 430 and 360 nm, respectively. The E isomer of the phenoxide anion undergoes efficient autodetachment upon excitation of its lowest ππ* transition. For the E isomer of the carboxylate deprotomer, a one-way photoinitiated proton transfer generates the phenoxide deprotomer through a mechanism postulated to involve an excited-state enol–keto tautomerism followed by a series of ground-state rearrangements including a second proton transfer. This mechanism is supported by experiments in which the relevant intermediate keto isomer is prepared and spectroscopically probed and through master equation modeling of possible ground-state isomerization processes. The Z isomer of the carboxylate deprotomer shows a weak Z → E photoisomerization response that occurs in competition with photodestruction (presumably electron detachment), demonstrating that the E and Z isomers undergo different processes in their excited states. The study highlights the utility of isomer-selective spectroscopy for characterizing the photochemistry of isolated anions possessing multiple deprotonation sites

Reversible photoswitching of isolated ionic hemiindigos with visible light

Indigoid chromophores have emerged as versatile molecular photoswitches, offering efficient reversible photoisomerization upon exposure to visible light. Here we report synthesis of a new class of permanently charged hemiindigos (HIs) and characterization of photochemical properties in gas phase and solution. Gas-phase studies, which involve exposing mobility-selected ions in a tandem ion mobility mass spectrometer to tunable wavelength laser radiation, demonstrate that the isolated HI ions are photochromic and can be reversibly photoswitched between Z and E isomers. The Z and E isomers have distinct photoisomerization response spectra with maxima separated by 40–80 nm, consistent with theoretical predictions for their absorption spectra. Solvation of the HI molecules in acetonitrile displaces the absorption bands to lower energy. Together, gas-phase action spectroscopy and solution NMR and UV/Vis absorption spectroscopy represent a powerful approach for studying the intrinsic photochemical properties of HI molecular switches

Photodetachment and photoreactions of substituted naphthalene anions in a tandem ion mobility spectrometer

Substituted naphthalene anions (deprotonated 2-naphthol and 6-hydroxy-2-naphthoic acid) are spectroscopically probed in a tandem drift tube ion mobility spectrometer (IMS). Target anions are selected according to their drift speed through nitrogen buffer gas in the first IMS stage before being exposed to a pulse of tunable light that induces either photodissociation or electron photodetachment, which is conveniently monitored by scavenging the detached electrons with trace SF6 in the buffer gas. The photodetachment action spectrum of the 2-naphtholate anion exhibits a band system spanning 380-460 nm with a prominent series of peaks spaced by 440 cm-1, commencing at 458.5 nm, and a set of weaker peaks near the electron detachment threshold corresponding to transitions to dipole-bound states. The two deprotomers of 6-hydroxy-2-naphthoic acid are separated and spectroscopically probed independently. The molecular anion formed from deprotonation of the hydroxy group gives rise to a photodetachment action spectrum similar to that of the 2-naphtholate anion with an onset at 470 nm and a maximum at 420 nm. Near the threshold, the photoreaction with SF6 is observed with displacement of an OH group by an F atom. In contrast, the anion formed from deprotonation of the carboxylic acid group gives rise to a photodissociation action spectrum, recorded on the CO2 loss channel, lying at much shorter wavelengths with an onset at 360 nm and maximum photoresponse at 325 nm

Photo- and Collision-Induced Isomerization of a Charge-Tagged Norbornadiene–Quadricyclane System

Molecular photoswitches based on the norbornadiene-quadricylane (NBD-QC) couple have been proposed as key elements of molecular solar thermal energy storage schemes. To characterize the intrinsic properties of such systems, reversible isomerization of a charge-tagged NBD-QC carboxylate couple is investigated in a tandem ion mobility mass spectrometer, using light to induce intramolecular [2 + 2] cycloaddition of NBD carboxylate to form the QC carboxylate and driving the back reaction with molecular collisions. The NBD carboxylate photoisomerization action spectrum recorded by monitoring the QC carboxylate photoisomer extends from 290 to 360 nm with a maximum at 315 nm, and in the longer wavelength region resembles the NBD carboxylate absorption spectrum recorded in solution. Key structural and photochemical properties of the NBD-QC carboxylate system, including the gas-phase absorption spectrum and the energy storage capacity, are determined through computational studies using density functional theory

Tissue-specific effects of central leptin on the expression of genes involved in lipid metabolism in liver and white adipose tissue

Copyright (2007) The Endocrine Society .The paper can be found at the following URL on the website http://endo.endojournals.org

Regulation of insulin-stimulated glucose uptake in rat white adipose tissue upon chronic central leptin infusion: effects on adiposity

Copyright (2011) The Endocrine Society .The paper can be found at the following URL on the website http://endo.endojournals.org

Engineering phosphatidylinositol-4,5-bisphosphate model membranes enriched in endocytic cargo: a neutron reflectometry, AFM and QCM-D structural study

The combination of in vitro models of biological membranes based on solid-supported lipid bilayers (SLBs) and of surface sensitive techniques, such as neutron reflectometry (NR), atomic force microscopy (AFM) and quartz crystal microbalance with dissipation monitoring (QCM-D), is well suited to provide quantitative information about molecular level interactions and lipid spatial distributions. In this work, cellular plasma membranes have been mimicked by designing complex SLB, containing phosphatidylinositol 4,5-bisphosphate (PtdIns4,5P2) lipids as well as incorporating synthetic lipo-peptides that simulate the cytoplasmic tails of transmembrane proteins. The QCM-D results revealed that the adsorption and fusion kinetics of PtdIns4,5P2 are highly dependent of Mg2+. Additionally, it was shown that increasing concentrations of PtdIns4,5P2 leads to the formation of SLBs with higher homogeneity. The presence of PtdIns4,5P2 clusters was visualized by AFM. NR provided important insights about the structural organization of the various components within the SLB, highlighting that the leaflet symmetry of these SLBs is broken by the presence of CD4-derived cargo peptides. Finally, we foresee our study to be a starting point for more sophisticated in vitro models of biological membranes with the incorporation of inositol phospholipids and synthetic endocytic motifs.publishe

Near-infrared reversible photoswitching of an isolated azobenzene-stilbene dye

Photoswitching of a charged azobenzene-stilbene dye is investigated through laser excitation in a tandem ion mobility mass spectrometer. Action spectra associated with E→Z and Z→E photoisomerisation of the stilbene group exhibit bands at 685 and 440 nm, corresponding to S1←S0 and S3←S0 transitions, respectively. The data suggest that isomers possessing a Z configuration of the azobenzene unit rapidly convert to E isomers and are not discernible using ion mobility spectrometry, and that photoisomerisation occurs through excited state dynamics rather than statistical isomerisation on the ground state potential energy surface