Stereodivergent, Diels-Alder-initiated organocascades employing α,β-unsaturated acylammonium salts: scope, mechanism, and application.

Chiral α,β-unsaturated acylammonium salts are novel dienophiles enabling enantioselective Diels-Alder-lactonization (DAL) organocascades leading to cis- and trans-fused, bicyclic γ- and δ-lactones from readily prepared dienes, commodity acid chlorides, and a chiral isothiourea organocatalyst under mild conditions. We describe extensions of stereodivergent DAL organocascades to other racemic dienes bearing pendant secondary and tertiary alcohols, and application to a formal synthesis of (+)-dihydrocompactin is described. A combined experimental and computational investigation of unsaturated acylammonium salt formation and the entire DAL organocascade pathway provide a rationalization of the effect of Brønsted base additives and enabled a controllable, diastereodivergent DAL process leading to a full complement of possible stereoisomeric products. Evaluation of free energy and enthalpy barriers in conjunction with experimentally observed temperature effects revealed that the DAL is a rare case of an entropy-controlled diastereoselective process. NMR analysis of diene alcohol-Brønsted base interactions and computational studies provide a plausible explanation of observed stabilization of exo transition-state structures through hydrogen-bonding effects

Fine structure of Vavilov-Cherenkov radiation near the Cherenkov threshold

We analyze the Vavilov-Cherenkov radiation (VCR) in a dispersive nontransparent dielectric air-like medium both below and above the Cherenkov threshold, in the framework of classical electrodynamics. It is shown that the transition to the subthreshold energies leads to the destruction of electromagnetic shock waves and to the sharp reduction of the frequency domain where VCR is emitted. The fine wake-like structure of the Vavilov-Cherenkov radiation survives and manifests the existence of the subthreshold radiation in the domain of anomalous dispersion. These domains can approximately be defined by the two phenomenological parameters of the medium, namely, the effective frequency of oscillators and the damping describing an interaction with the other degrees of freedom.Comment: 9 pages, 6 figure

Enantioselective stereodivergent nucleophile-dependent isothiourea-catalysed domino reactions

We thank the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013) ERC grant agreement no. 279850 (J.E.T.) and the EPSRC (EP/J018139/1, A.M.). ADS thanks the Royal Society for a Wolfson Research Merit Award.α,β-Unsaturated acyl ammoniums generated from the reaction of α,β-unsaturated 2,4,6-trichlorophenol (TCP) esters bearing a pendent enone with an isothiourea organocatalyst are versatile intermediates in a range of enantioselective nucleophile-dependent domino processes to form complex products of diverse topology with excellent stereoselectivity. Use of either 1,3-dicarbonyls, acyl benzothiazoles, or acyl benzimidazoles as nucleophiles allows three distinct, diastereodivergent domino reaction pathways to be accessed to form various fused polycyclic cores containing multiple contiguous stereocentres.Publisher PDFPeer reviewe

Genetic diversity in wild diploid wheat T. urartu revealed by SSR markers

Genetic diversity of 74 T. urartu genotypes was studied using 11 SSR (simple sequence repeats) markers. The number of alleles ranged from 4 to 15, with an average of 8 alleles per primer. The mean values for the expected heterozygosity (He) and polymorphism information content (PIC) over all loci and populations were 0.56 and 0.52, respectively. From a geographic viewpoint the higher diversities were observed in Jordan, followed by Syria and Turkey. Diversity revealed within countries was higher than among them, even in the same regions of the relevant countries. The analysis of molecular variance revealed that most of the genetic variability was accounted for by differences within populations (90%), with less variability among them (10%). The dendrogram generated based on Nei’s dissimilarity matrix revealed three main clusters for which the grouping patterns were not clearly associated with the geographic origins, indicating the gene flow among different countries. Principal coordinate analysis (PCoA) confirmed subgrouping obtained by cluster analysis. In general, genetic distances between geographic regions were low or moderate, which was also supported by low values of pairwise Fst. Our findings can direct the sampling strategies on T. urartu in studied regions to find beneficial alleles. The heterotic groups detected by cluster and PCoA analysis in the present study can serve as effective candidates in crossing programs to broaden the genetic base in T. urartu

Mainstreaming Of Disaster Risk Analysis Into Gabala District Development Planning

Gabala district is located in a disaster prone part of Azerbaijan. Current natural and social conditions in Gabala make children very vulnerable. In addition preparedness level of schools is rather low that reduce capacity of local schools to meet hazards without human and material losses. Mainstreaming, in the context of disaster risks is the practice of supporting communities through land planning and development. This means that regular development process should take into consideration disaster risks, reducing risk level in a particular area.“Risk informed development programming” is the approach, according to which development interventions (ie building new schools and hospitals, building roads, bridges and communication lines, expanding cities and communities, building factories etc.) support risk reduction measures. For example, road constructions take into account all hazards possible hazards (ie landslides, floods, rockfalls, etc.) and relevant measures are incorporated during the construction period to minimize possible impact in the future

Income Inequality, Distributive Justice, and Sustainable Development: Implications for Niagara Peninsula Aspiring Global Geopark

The rising inequalities across the world, including in Canada, present a challenge to achieving Sustainable Development Goals (SDGs). Under the auspices of UNESCO, supporting the implementation of SDGs is one of the main missions of geoparks. It has been shown that geoparks can foster the implementation of SDG 10 (reducing inequalities), but there is a dearth of studies specifically exploring the means and channels through which a geopark can help reduce income inequality. This study aims to fill that gap by exploring income inequality in the Niagara region through the lens of distributive justice with a focus on the role of Niagara Peninsula Aspiring Global Geopark (NPAGG) in reducing income inequality in Niagara. This study employs a qualitative research approach to collect data via 16 semi-structured interviews with the NPAGG board of directors, people who are advocating for poverty alleviation and reduction of inequalities in Niagara, and local tourism-related business owners. Thematic analysis was conducted on the collected data to explore the role of the NPAGG in addressing income inequality in the Niagara region. All the participants agreed that the income inequality in Niagara is unfair and needs to be addressed. The results of the thematic analysis show that in the pursuit of more equitable distribution in Niagara, the NPAGG can present economic benefits – with a direct yet incremental impact on income inequality – and societal benefits – with indirect yet necessary implications for addressing income inequality. There are two main limiting factors identified for the NPAGG’s role in battling income disparities: 1) it is not the primary objective of the NPAGG, and 2) the problem of income inequality is much bigger than the NPAGG. Moreover, inflation, negative environmental impacts, and dependence on tourism were identified as minor risks associated with the NPAGG development. Although the findings of this study may not be generalized to other geoparks around the world, they offer understanding of what to expect from geoparks in addressing income disparities

TEEB Scoping study for forestry sector of Azerbaijan

The aim of the FLEG II Program is to promote sustainable forest governance, management, and protection of forests in the participating countries, including Azerbaijan. The program supports forest governance through enhancing forest policy, legislation and institutional arrangements, and implementing sustainable forest management models on a pilot basis. This TEEB scoping study, as a part of the FLEG II program, makes a preliminary analysis of the ecosystem services provided by forested areas in Azerbaijan. Azerbaijanis consider forests to be one of the most valuable natural resources in their country. It is estimated that the total area of forests and scrublands in Azerbaijan is more than 860,000 ha, most of which are located in mountain areas. Riparian and plain forests in Azerbaijan only occupy areas, where the groundwater table is rather close to the surface that may permanently supply trees with water. Forests in Azerbaijan provide a broad range of ecosystem services. In most of the rural areas, fuelwood is a major source of energy. Also, forested watersheds are the only source of drinking water for all of the population in Azerbaijan that live in mountain regions. In addition, forested mountain areas are the preferred recreational areas for tourists in Azerbaijan. In order to analyze the ecosystem services of forests, “Business as Usual” (BAU) and “Sustainable Ecosystem Management” (SEM) analytical approaches have been used. Under BAU management, nonsustained use of natural resources is understood, that gives only short-term gains. In this type of management, some stakeholders may maximize their benefits for short-term periods, causing substantial damages to ecosystems and, in this way, negatively affecting financial and social conditions of other stakeholders. Under the SEM management, economic benefits are maximized through planned and integrated use of natural resources. While economic benefits of some stakeholders under the SEM may be minimized for short-term periods, over the long-term periods, economic gains for all types of stakeholders are increased and sustained. Evaluation of the current state of the forestry sector and its policy context enables us to understand existing challenges and perspectives (TEEB foundations, 2010). The traditional BAU practices in Azerbaijan include illegal logging, unsustainable tourism, overgrazing and other activities. In addition, the impacts of climate changes are considered as a BAU practice, since it has mostly been recognized as the human induced phenomena. SEM is taken as an alternative policy to the BAU. All-inclusive analyses of alternative policies (BAU vs. SEM), including their impacts on biodiversity and ecosystem services is given. These analyses describe advantages of SEM practices over the long-term periods. This study also identifies key elements for a full TEEB study, including a roadmap of activities, and a list of important outputs to be delivered in such a study

Evaluation of Factors Contributing to Floods in the Outlet Part of the Kura River, Azerbaijan

Flow regulation has long been thought as the most effective method for the flood prevention. However, this experience has shown its limitations over the last few decades when the strong floods have been observed in regulated rivers. Since most of rivers have been highly affected by human activities, there are obvious changes in the genesis and nature of floods. Floods at the mouth part of the Kura River are observed as a combined result of climatic and non-climatic factors. Climatic factors directly impact flood characteristics-peak, duration and volume. Main climatic factors of floods in the Kura River include intense snowmelt episodes and intense rain as well as Caspian Sea level changes. Non-climatic factors include changes in land use, deforestation, erosion, flow regulation, water withdrawals and channel siltation. Over the past century, there is an increased contribution of non climatic factors to the flood formation processes in the Kura River. At the same time channel siltation has increased the role of non-climatic factors. In addition, the Caspian Sea level rise became additional contribution to the level rise in the mouth area that causes backwater propagation on the free surface. Due to the channel siltation and the backwater propagation at the mouth reach, floods may occur even during lower discharges characterized with longer durations

Aryloxide-facilitated catalyst turnover in enantioselective α,β-unsaturated acyl ammonium catalysis

The authors thank the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) ERC grant agreement no. 279850 (A.D.S) and the EPSRC (EP/J018139/1, A.M.) for funding. A.D.S. thanks the Royal Society for a Wolfson Research Merit Award.A new general concept for α,β-unsaturated acyl ammonium catalysis is reported that uses p-nitrophenoxide release from an α,β-unsaturated p-nitrophenyl ester substrate to facilitate catalyst turnover. This method was used for the enantioselective isothiourea-catalyzed Michael addition of nitroalkanes to α,β-unsaturated p-nitrophenyl esters in generally good yield and with excellent enantioselectivity (27 examples, up to 79% yield, 99:1 er). Mechanistic studies identified rapid and reversible catalyst acylation by the α,β-unsaturated p-nitrophenyl ester, and a recently reported variable-time normalization kinetic analysis method was used to delineate the complex reaction kinetics.Publisher PDFPeer reviewe