Metal-Metal Cooperation in the Oxidation of a Flapping Platinum Butterfly by Haloforms: Experimental and Theoretical Evidence

The model 1-DFT for the butterfly complex [{Pt(C¿C*)(µ-pz)}2] (1; HC¿C* = 1-(4-(ethoxycarbonyl)phenyl)-3-methyl-1H-imidazol-2-ylidene) shows two minima in the potential energy surface of the ground state in acetone solution: the butterfly-wing-spreading molecules 1-s, (dPt-Pt ˜ 3.20 Å) and the wing-folding molecules 1-f (dPt-Pt = 3.00 Å). Both minima are very close in energy (¿G° = 1.7 kcal/mol) and are connected through a transition state, which lies only 1.9 kcal/mol above 1-s and 0.2 kcal/mol above 1-f. These very low barriers support a fast interconversion process, resembling a butterfly flapping, and the presence of both conformers in acetone solution. However, the 1-f ratio is so low that it is undetectable in the excitation and emission spectra of 1 in 2-MeTHF of diluted solutions (10-5 M) at 77 K, while it is seen in more concentrated solutions (10-3 M). In acetone solution, 1 undergoes a [2c, 2e] oxidation by CHX3 (X = Cl, Br) in the sunlight to render the Pt2(III, III) compounds [{Pt(C¿C*)(µ-pz)X)}2] (X = Cl (2-Cl), Br (2-Br)). In concentrated solutions, 1 can react with CHCl3 under blue light to give 2-Cl and with CHBr3 in the dark, the latter rendering the compound [BrPt(C¿C*)(µ-pz)2Pt(C¿C*)CHBr2] (3-Br) or mixtures of 2-Br and 3-Br if the reaction is performed under an argon atmosphere or in the air, respectively. Mechanistic studies showed that in concentrated solutions the oxidation processes follow a radical mechanism being the MMLCT-based species 1-f, those which trigger the reaction of 1 with CHBr3 and CHCl3. In the ground state (S0f), it promotes the thermal oxidation of 1 by CHBr3 and in the first singlet excited state (S1f) the blue-light-driven photooxidation of 1 by CHCl3. Complexes, 2-Cl, 2-Br, and 3-Br were selectively obtained and fully characterized, showing Pt-Pt distances (ca. 2.6 Å) shorter than that of the starting complex, 1. They are, together with the analogous [{Pt(C¿C*)(µ-pz)I)}2] and [IPt(C¿C*)(µ-pz)2Pt(C¿C*)CHI2], the only dinuclear metal-metal-bonded PtIII(µ-pz)2PtIII compounds reported to date

Prolamin proteins alteration in durum wheat by species of the genus Eurygaster and Aelia (Insecta, Hemiptera)

Postprint (published version

Relationships between livelihoods, well-being, and marine protected areas : evidence from a community survey, Watamu Marine National Park and Reserve, Kenya

Funding information: UK Global Challenges Research Fund and Scottish Funding Council (projects 'Community Capabilities and Marine Protected Area Governance' and 'Mitigation of the effects of COVID-19 crisis in coastal Kenya XFC092').At a time of massive expansion of Marine Protected Areas, there is a need to learn more about their sustainability and success. This study draws on a framework which operationalizes three-dimensions of well-being: material, relational, and subjective, in order to measure the range of benefits and disbenefits experienced by local communities from protected areas. 308 respondents from two coastal Kenyan villages adjacent to the Watamu Marine National Reserve participated in a telephone survey in June and July 2020. The study recorded varying levels of dependency on the marine environment for the livelihoods of residents. A key finding of this study was that benefits reported by participants consistently exceeded disbenefits. A principal components analysis identified that the number of benefits and disbenefits experienced explained the most variance within the dataset. The benefits and disbenefits reported contributed to each dimension of human well-being. The highest ranked benefits reported contributed to subjective well-being (‘better health’, and ‘ability to enjoy a clean and healthy creek and ocean’), and the most frequently reported disbenefits related to relational and material well-being (for instance ‘increased conflict and social tension’ ‘increased poverty’, ‘fewer supplies of food’). Practical local conservation efforts can address relational disbenefits through better partnership working, and material disbenefits by supporting pro-conservation, alternative livelihoods. The findings demonstrate the relevance of understanding social trends for marine protected area governance and management. The paper offers insights into how fundamental relations between protected marine environments, livelihoods, and well-being may affect the perceptions and success of conservation initiatives amongst local communities.Publisher PDFPeer reviewe

Electrophilicity of neutral square-planar organosilver(III) compounds

Neutral Ag(III) complexes stabilised with just monodentate ligands are here unambiguously established. In a series of square-planar (CF3)3Ag(L) compounds with hard and soft Group 15 donor ligands, L, the metal center has been found to exhibit substantial acidity favouring apical coordination of an additional ligand under no coordination constraints

Characterization of Spray A flame structure for parametric variations in ECN constant-volume vessels using chemiluminescence and laser-induced fluorescence

The transient and quasi-steady flame structure of reacting fuel sprays produced by single-hole injectors has been studied using chemiluminescence imaging and Planar Laser-Induced Fluorescence (PLIF) in various constant-volume facilities at different research institutes participating in the Engine Combustion Network (ECN). The evolution of the high-temperature flame has been followed based on chemiluminescence imaging of the excited-state hydroxyl radical (OH*), and PLIF of ground-state OH. Regions associated with low-temperature chemical reactions are visualized using formaldehyde (CH2O) PLIF with 355-nm excitation. We compare the results obtained by different research institutes under nominally identical experimental conditions and fuel injectors. In spite of design differences among the various experimental facilities, the results are consistent. This lends confidence to studies of transient behavior and parameter variations performed by individual research groups. We present results of the transient flame structures at Spray A reference conditions, and include parametric variations around this baseline, involving ambient temperature, oxygen concentration and injection pressure. Key results are the observed influence of an entrainment wave on the transient flame behavior, model-substantiated explanations for the high-intensity OH* lobes at the lift-off length and differences with OH PLIF, and a general analogy of the flame structures with a spray cone along which the flame tends to locate for the applied parametric variations

Programme evaluation training for health professionals in francophone Africa: process, competence acquisition and use

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Evolution of Mycobacterium tuberculosis complex lineages and their role in an emerging threat of multidrug resistant tuberculosis in Bamako, Mali

In recent years Bamako has been faced with an emerging threat from multidrug resistant TB (MDR-TB). Whole genome sequence analysis was performed on a subset of 76 isolates from a total of 208 isolates recovered from tuberculosis patients in Bamako, Mali between 2006 and 2012. Among the 76 patients, 61(80.3%) new cases and 15(19.7%) retreatment cases, 12 (16%) were infected by MDR-TB. The dominant lineage was the Euro-American lineage, Lineage 4. Within Lineage 4, the Cameroon genotype was the most prevalent genotype (n = 20, 26%), followed by the Ghana genotype (n = 16, 21%). A sub-clade of the Cameroon genotype, which emerged ~22 years ago was likely to be involved in community transmission. A sub-clade of the Ghana genotype that arose approximately 30 years ago was an important cause of MDR-TB in Bamako. The Ghana genotype isolates appeared more likely to be MDR than other genotypes after controlling for treatment history. We identified a clade of four related Beijing isolates that included one MDR-TB isolate. It is a major concern to find the Cameroon and Ghana genotypes involved in community transmission and MDR-TB respectively. The presence of the Beijing genotype in Bamako remains worrying, given its high transmissibility and virulence

Femmes et hommes face aux grossesses non prévues au Maroc et au Sénégal

Cet article étudie la manière dont les femmes ou les couples gèrent les grossesses non prévues dans les capitales du Maroc et du Sénégal (Rabat et Dakar), deux pays soumis à des règles strictes en matière de sexualité des célibataires. Nous analysons les logiques sociales et individuelles qui prévalent à l'annonce d'une grossesse inattendue et la manière dont se prennent les décisions qui vont aboutir à la poursuite de cette grossesse ou à son interruption. Nous nous basons sur des données qualitatives tirées d'un programme financé par l'Union Européenne entre 2005 et 2009, sur l'usage de la contraception d'urgence dans les villes africaines. Nos résultats montrent qu'en dépit de programmes de planification familiale plus performants dans leur pays, les femmes de Rabat vivent leur entrée en sexualité dans des conditions difficiles. Si à Dakar la chasteté avant le mariage est prônée, le non-respect de cette règle entraîne des sanctions beaucoup moins sévères qu'au Maroc. Le choix de l'avortement en cas de grossesse non prévue évolue avec le cycle de vie des individus et selon le stade de la relation. Une pratique envisageable à un moment donné, ne l'est plus forcément à d'autres moments de la relation. Enfin, dans les deux villes, nos données révèlent une forte implication des familles dans la gestion de la formation des couples et de leur fécondité. Cette tendance apparaît cependant plus exacerbée au Maroc où les familles se mobilisent parfois âprement pour obliger ou interdire un avortement

A large-scale species level dated angiosperm phylogeny for evolutionary and ecological analyses.

Phylogenies are a central and indispensable tool for evolutionary and ecological research. Even though most angiosperm families are well investigated from a phylogenetic point of view, there are far less possibilities to carry out large-scale meta-analyses at order level or higher. Here, we reconstructed a large-scale dated phylogeny including nearly 1/8th of all angiosperm species, based on two plastid barcoding genes, matK (incl. trnK) and rbcL. Novel sequences were generated for several species, while the rest of the data were mined from GenBank. The resulting tree was dated using 56 angiosperm fossils as calibration points. The resulting megaphylogeny is one of the largest dated phylogenetic tree of angiosperms yet, consisting of 36,101 sampled species, representing 8,399 genera, 426 families and all orders. This novel framework will be useful for investigating different broad scale research questions in ecological and evolutionary biology

Identifying Where REDD plus Financially Out-Competes Oil Palm in Floodplain Landscapes Using a Fine-Scale Approach

Reducing Emissions from Deforestation and forest Degradation (REDD+) aims to avoid forest conversion to alternative land-uses through financial incentives. Oil-palm has high opportunity costs, which according to current literature questions the financial competitiveness of REDD+ in tropical lowlands. To understand this more, we undertook regional fine-scale and coarse-scale analyses (through carbon mapping and economic modelling) to assess the financial viability of REDD+ in safeguarding unprotected forest (30,173 ha) in the Lower Kinabatangan floodplain in Malaysian Borneo. Results estimate 4.7 million metric tons of carbon (MgC) in unprotected forest, with 64% allocated for oil-palm cultivations. Through fine-scale mapping and carbon accounting, we demonstrated that REDD+ can outcompete oil-palm in regions with low suitability, with low carbon prices and low carbon stock. In areas with medium oil-palm suitability, REDD+ could outcompete oil palm in areas with: very high carbon and lower carbon price; medium carbon price and average carbon stock; or, low carbon stock and high carbon price. Areas with high oil palm suitability, REDD+ could only outcompete with higher carbon price and higher carbon stock. In the coarse-scale model, oil-palm outcompeted REDD+ in all cases. For the fine-scale models at the landscape level, low carbon offset prices (US $3 MgCO_{2} e) would enable REDD+ to outcompete oil-palm in 55$27 million to secure these areas for 25 years. Higher carbon offset price (US $30 MgCO_{2}e) would increase the competitiveness of REDD+ within the landscape but would still only capture between 69$380–416 million in carbon financing. REDD+ has been identified as a strategy to mitigate climate change by many countries (including Malaysia). Although REDD+ in certain scenarios cannot outcompete oil palm, this research contributes to the global REDD+ debate by: highlighting REDD+ competitiveness in tropical floodplain landscapes; and, providing a robust approach for identifying and targeting limited REDD+ funds