Discussions Regarding the Invalidity of States’ Consent in the Field of Public International Law

This article aims at a comparative analysis of the invalidity of states’ consent and examines the manner in which they are regulated in the Public International Law and in the domestic law. Thus, according to the dispositions of the Vienna Convention (1969) on the law of treaties between states, invalidity of states’ consent are: breach of the dispositions of the domestic law of the state regarding the competence to sign treaties; the error; the fraud; the corruption of a state representative; the coercion of a state representative; the coercion against a state. The invalidity of states’ consent are sanctioned both in the matter of the Public International Law as well as in the domestic civil law by nullity, either absolute (such as the coercion exercised on the state representative and the coercion against a state) or relative (such as the breach of the dispositions of the domestic law of the state regarding the competence to sign treaties, the error, the fraud or the corruption of a state representative). In certain cases, the dispositions of the domestic law are fully mirrored by the regulations of the Vienna Convention, as is the case of the fraud, but there are also cases – the breach of the dispositions of the domestic law of the state regarding the competence to sign treaties – where the Vienna Convention introduces a disposition which flagrantly contradicts the civil theory in the matter, the state being able to invoke itself the defect in its consent. At the same time, in the domestic civil law, the rule according to which no one can invoke his/her own turpitude is widely sanctioned. We conclude by showing that the manner of regulation of nullity taken over from the domestic civil law and transposed in the dispositions of the Vienna Convention fails to meet the exigencies and rigors of the definition of nullity.Public International Law, civil law, Vienna Convention

Spectral Variability from the Patchy Atmospheres of T and Y Dwarfs

Brown dwarfs of a variety of spectral types have been observed to be photometrically variable. Previous studies have focused on objects at the L/T transition, where the iron and silicate clouds in L dwarfs break up or dissipate. However, objects outside of this transitional effective temperature regime also exhibit variability. Here, we present models for mid-late T dwarfs and Y dwarfs. We present models that include patchy salt and sulfide clouds as well as water clouds for the Y dwarfs. We find that for objects over 375 K, patchy cloud opacity would generate the largest amplitude variability within near-infrared spectral windows. For objects under 375 K, water clouds also become important and generate larger amplitude variability in the mid-infrared. We also present models in which we perturb the temperature structure at different pressure levels of the atmosphere to simulate hot spots. These models show the most variability in the absorption features between spectral windows. The variability is strongest at wavelengths that probe pressure levels at which the heating is the strongest. The most illustrative types of observations for understanding the physical processes underlying brown dwarf variability are simultaneous, multi-wavelength observations that probe both inside and outside of molecular absorption features.Comment: 6 pages, 5 figures, Accepted for publication in ApJ Letter

ROS-mediated Cytotoxicity and Macrophage Activation Induced by TiO2 Nanoparticles with Different in vitro Non-Cellular Photocatalytic Activities

AIM: The aim of the study described in the present paper was to assess several in vitro effects of TiO2 nanoparticles with different colloidal and photocatalytic properties on RAW 264.7 macrophages.METHODS: The cells were exposed to Degussa P25 titania and two other types of nanoparticles synthesized by a hydrothermal procedure in our laboratory: undoped and Fe3+-doped TiO2. Compared to Degussa P25, the hydrothermal nanomaterials were significantly less active in inducing cytotoxicity, production of intracellular reactive oxygen species (ROS) and release of pro-inflammatory cytokine interleukin-6 (IL-6). The induced effects were analysed with respect to nanoparticle size, surface charge, hydrophilicity, semiconductor bandgap energy and photocatalytic generation of ROS under non-cellular conditions.RESULTS: The overall results indicated that TiO2 nanoparticles with higher surface charge, hydrophilic surfaces and enhanced photocatalytic properties may preferentially induce macrophage cell damage and inflammation compared to other TiO2 nanomaterials.CONCLUSION: The present findings are relevant for studies regarding the evaluation of risks raised by self-cleaning technologies involving nanosized hydrophilic TiO2 photocatalysts as well as development of synthesis methods optimized for producing biocompatible TiO2 nanomaterials

Water Clouds in Y Dwarfs and Exoplanets

The formation of clouds affects brown dwarf and planetary atmospheres of nearly all effective temperatures. Iron and silicate condense in L dwarf atmospheres and dissipate at the L/T transition. Minor species such as sulfides and salts condense in mid-late T dwarfs. For brown dwarfs below Teff=450 K, water condenses in the upper atmosphere to form ice clouds. Currently over a dozen objects in this temperature range have been discovered, and few previous theoretical studies have addressed the effect of water clouds on brown dwarf or exoplanetary spectra. Here we present a new grid of models that include the effect of water cloud opacity. We find that they become optically thick in objects below Teff=350-375 K. Unlike refractory cloud materials, water ice particles are significantly non-gray absorbers; they predominantly scatter at optical wavelengths through J band and absorb in the infrared with prominent features, the strongest of which is at 2.8 microns. H2O, NH3, CH4, and H2 CIA are dominant opacity sources; less abundant species such as may also be detectable, including the alkalis, H2S, and PH3. PH3, which has been detected in Jupiter, is expected to have a strong signature in the mid-infrared at 4.3 microns in Y dwarfs around Teff=450 K; if disequilibrium chemistry increases the abundance of PH3, it may be detectable over a wider effective temperature range than models predict. We show results incorporating disequilibrium nitrogen and carbon chemistry and predict signatures of low gravity in planetary- mass objects. Lastly, we make predictions for the observability of Y dwarfs and planets with existing and future instruments including the James Webb Space Telescope and Gemini Planet Imager.Comment: 23 pages, 20 figures, Revised for Ap

The First Spectrum of the Coldest Brown Dwarf

The recently discovered brown dwarf WISE 0855 presents our first opportunity to directly study an object outside the Solar System that is nearly as cold as our own gas giant planets. However the traditional methodology for characterizing brown dwarfs---near infrared spectroscopy---is not currently feasible as WISE 0855 is too cold and faint. To characterize this frozen extrasolar world we obtained a 4.5-5.2 $\mu$m spectrum, the same bandpass long used to study Jupiter's deep thermal emission. Our spectrum reveals the presence of atmospheric water vapor and clouds, with an absorption profile that is strikingly similar to Jupiter. The spectrum is high enough quality to allow the investigation of dynamical and chemical processes that have long been studied in Jupiter's atmosphere, but now on an extrasolar world.Comment: submitted to ApJ