Le marché des stupéfiants dans une société mondialisée

I trattati di cooperazione internazionale esistono da decenni, così come il traffico internazionale di droga. Tuttavia, essi non sono ancora riusciti a lottare efficacemente contro tale tipo di traffico. Questo articolo ripercorre la storia del traffico internazionale e rinvia particolarmente a certi esempi noti come quelli della Colombia e dell’Afganistan. Les traités de coopération internationale existent depuis des décennies, tout comme le trafic international de drogues. Toutefois, ils n’ont pas encore réussi à lutter efficacement contre le trafic international de drogues. Ce texte révise l’histoire du trafic international et renvoie plus particulièrement à certains exemples connus comme ceux de la Colombie et de l’Afghanistan. International co-operation treaties exist for decades, as well as the international drug traffic. However, they did not yet succeed in efficiently fighting international drug trafficking. This paper reviews the history of international traffic and illustrate the discussion with known examples like those of Colombia and Afghanistan

Direct 17O Dynamic Nuclear Polarization of Single-Site Heterogeneous Catalysts

We utilize direct 17O DNP for the characterization of non-protonated oxygens in heterogeneous catalysts. The optimal sample preparation and population transfer approach for 17O direct DNP experiments performed on silica surfaces are determined and applied to the characterization of Zr- and Y-based mesoporous silica-supported single-site catalysts

Anaerobic microorganisms in astrobiological analogue environments: from field site to culture collection

Astrobiology seeks to understand the limits of life and to determine the physiology of organisms in order to better assess the habitability of other worlds. To successfully achieve these goals we require microorganisms from environments on Earth that approximate to extraterrestrial environments in terms of physical and/or chemical conditions. The most challenging of these environments with respect to sample collection, isolation and cultivation of microorganisms are anoxic environments. In this paper, an approach to this challenge was implemented within the European Union's MASE (Mars Analogues for Space Exploration) project. In this review paper, we aim to provide a set of methods for future field work and sampling campaigns. A number of anoxic environment based on characteristics that make them analogous to past and present locations on Mars were selected. They included anoxic sulphur-rich springs (Germany), the salt-rich Boulby Mine (UK), a lake in a basaltic context (Iceland), acidic sediments in the Rio Tinto (Spain), glacier samples (Austria) and permafrost samples (Russia and Canada). Samples were collected under strict anoxic conditions to be used for cultivation and genomic community analysis. Using the samples, a culturing approach was implemented to enrich anaerobic organisms using a defined medium that would allow for organisms to be grown under identical conditions in future physiological comparisons. Anaerobic microorganisms were isolated and deposited with the DSMZ (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH) culture collection to make them available to other scientists. In MASE, the selected organisms are studied with respect to survival and growth under Mars relevant stresses. They are artificially fossilized and the resulting biosignatures studied and used to investigate the efficacy of life detection instrumentation for planetary missions. Some of the organisms belong to genera with medical and environmental importance such as Yersinia spp., illustrating how astrobiology field research can be used to increase the availability of microbial isolates for applied terrestrial purposes

Assessing Long-Term Excavation Damage in Switzerland’s Bedretto Adit: A Field Investigation in the Northern Section

The Bedretto adit, in the Alps of Switzerland, was excavated in 1972–1982 as an auxiliary adit for the main Furka Base Tunnel. The adit is 5218 m long, being excavated mostly in the Rotondo Granite with drill and blast methods to create a horseshoe cross-section. Much of the tunnel has remained unlined and such long observation periods are seldom available since tunnels typically are lined shortly after construction and mines are often closed or backfilled. Previous research in 2004 characterized the depth of failure (DoF) around the adit and found on average a depth of 1.1 ± 0.03 m. A site investigation was carried out in 2017, aimed to measure the DoF through 3D light detection and ranging scanned sections again. The new 3D scans covered a longer section of the tunnel with each scan, up to 6 m in length, compared to the previous laser scans with a single circumferential pass. The results were compared with the data from 2004 and with empirical and numerical prediction curves for Excavation Damage Zone depths. The findings indicate that between 2004 and 2017, the measured DoF generally extended, on average, by 0.1 m, implying that failure has progressed with time. Furthermore, the analysis showed that the volume of failure from 2004 extended up to 1.9 m3/m, and this volume increased to 3.2 m3/m in 2017 on average. The VoF was used as a means to overcome the challenge of comparing past to present scan results, since the exact location of the 2004 measurements were not known. Significant variations in the measured DoF at sections of the adit near faults and below a glacier indicate that these external factors can significantly influence the rock mass behaviour. When comparing the DoF to empirical excavation damage zone prediction intervals, the level of damage at the Bedretto adit is comparable with the outer excavation damage zone. This is a region of isolated micro-cracking, and it conceptually suggests that the continued spalling in the Bedretto adit is the results of crack propagation from initial excavation induced damage that leads to interaction even after 41 years since excavation works ceased

S-layers at second glance? Altiarchaeal grappling hooks (hami) resemble archaeal S-layer proteins in structure and sequence

This is the final version of the article. Available from Frontiers Media via the DOI in this recordResearch on SM1-MSI was supported by the German Research Foundation (Deutsche Forschungsgemeinschaft), grant no. MO 1977/3-1 given to CM-E. AJP was supported by the German National Academic Foundation (Studienstiftung des deutschen Volkes)

Synthesis of Supported Pd-0 Nanoparticles from a Single-Site Pd2+ Surface Complex by Alkene Reduction

A surface metal-organic complex, (-AlOx)Pd(acac) (acac = acetylacetonate), is prepared by chemically grafting the precursor Pd(acac)(2) onto gamma-Al2O3 in toluene at 25 degrees C. The resulting surface complex is characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and dynamic nuclear polarization surface-enhanced solid-state nuclear magnetic resonance spectroscopy (DNP SENS). This surface complex is a precursor in the direct synthesis of size-controlled Pd nanoparticles under mild reductive conditions and in the absence of additional stabilizers or pretreatments. Indeed, upon exposure to gaseous ethylene or liquid 1-octene at 25 degrees C, the Pd2+ species is reduced to form Pd-0 nanoparticles with a mean diameter of 4.3 +/- 0.6 nm, as determined by scanning transmission electron microscopy (STEM). These nanoparticles are catalytically relevant using the aerobic 1-phenylethanol oxidation as a probe reaction, with rates comparable to a conventional Pd/Al2O3 catalyst but without an induction period. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed reaction mass spectrometry (TPR-MS) reveal that the surface complex reduction with ethylene coproduces H-2, acetylene, and 1,3-butadiene. This process reasonably proceeds via an olefin activation/coordination/insertion pathway, followed by beta-hydride elimination to generate free Pd-0. The well-defined nature of the single-site supported Pd2+ precursor provides direct mechanistic insights into this unusual and likely general reductive process

Electrophilic Organoiridiunn(III) Pincer Complexes on Sulfated Zirconia for Hydrocarbon Activation and Functionalization

Single-site supported organometallic catalysts bring together the favorable aspects of homogeneous and heterogeneous catalysis while offering opportunities to investigate the impact of metal–support interactions on reactivity. We report a (dmPhebox)Ir(III) (dmPhebox = 2,6-bis(4,4-dimethyloxazolinyl)-3,5-dimethylphenyl) complex chemisorbed on sulfated zirconia, the molecular precursor for which was previously applied to hydrocarbon functionalization. Spectroscopic methods such as diffuse reflectance infrared Fourier transformation spectroscopy (DRIFTS), dynamic nuclear polarization (DNP)-enhanced solid-state nuclear magnetic resonance (SSNMR) spectroscopy, and X-ray absorption spectroscopy (XAS) were used to characterize the supported species. Tetrabutylammonium acetate was found to remove the organometallic species from the surface, enabling solution-phase analytical techniques in conjunction with traditional surface methods. Cationic character was imparted to the iridium center by its grafting onto sulfated zirconia, imbuing high levels of activity in electrophilic C–H bond functionalization reactions such as the stoichiometric dehydrogenation of alkanes, with density functional theory (DFT) calculations showing a lower barrier for β-H elimination. Catalytic hydrogenation of olefins was also facilitated by the sulfated zirconia-supported (dmPhebox)Ir(III) complex, while the homologous complex on silica was inactive under comparable conditions