Extension of shelf life of Nile tilapia (Oreochromis niloticus) fillets using seaweed extracts during refrigerated storage.

The effects of seaweed (Padina tetrastromatica, Sargassum natans, and Sargassum fluitans) ethanolic extracts on the quality and shelf life extension of Nile tilapia (Oreochromis niloticus) fillets were investigated during refrigerated storage for 20 days. Each of the seaweed ethanolic extracts solution (2%, w/v) was used for dipping the fish fillets for 10 min at 4°C. The control and seaweed extract-treated fillets were stored at 4 ± 1°C in air-tight polyethylene bags, and chemical, bacteriological, and sensory evaluation were performed at every 4 days' intervals. During the storage period, P. tetrastromatica extract significantly (p < .05) reduced the increment of pH, peroxide value, thiobarbituric acid reactive substances, and total volatile basic nitrogen values in Nile tilapia fillets compared to other seaweed extracts-treated and untreated fillets. The maximal total viable count of control, P. tetrastromatica, S. natans, and S. fluitans extracts-treated fillets was 6.53, 7.11, 6.75, and 7.10 log CFU/g at the 8th, 20th, 12th, and 16th days of storage, respectively. The total psychrotrophic count of control and seaweed extracts-treated fillets was also significantly increased (p < .05) throughout the storage period. The P. tetrastromatica extracts-treated fillets showed better sensory characteristics than other seaweed extracts-treated and control fillets. Results of this study suggest that ethanolic extracts (2%, w/v) of P. tetrastromatica extend the shelf life for 12 days longer than the control fillets in refrigerated conditions.

Socio-Economic Implications of COVID-19 Pandemic in South Asia: Emerging Risks and Growing Challenges.

The dramatic spread of COVID-19 has threatened human lives, disrupted livelihoods, and affected trade, economy and businesses across the globe. The global economy has begun to show major disruptions and is heading toward a severe recession with an unprecedented economic crisis. As the global economy is highly integrated and interdependent through the global supply chains, it has been profoundly affected by the COVID-19 pandemic. Although all countries have faced difficulties due to Covid-19, South Asian countries in particular have had to deal with a more challenging situation due to their large population, weak health facilities, high poverty rates, low socio-economic conditions, poor social protection systems, limited access to water and sanitation, and inadequate living space, necessary to maintain physical distancing and take other required measures to contain this pandemic. To contain the spread of the virus, South Asian countries have imposed stringent lockdowns, which have consequently affected the lives and livelihoods of millions of people in the region, where a third of world's poor live. Against this backdrop, this paper examines the existing and prospective impacts, risks and challenges of Covid-19 on key social and economic sectors including migration, tourism, informal sector, agriculture and rural livelihoods. The analysis revealed that COVID-19 is likely to affect economic growth, increase fiscal deficit and monetary burden, increase the risks of macroeconomic instability, decrease migration and remittance, reduce income from travel and tourism, and result in dwindling micro-small and medium industries and informal businesses. This is likely to deepen poverty and increase unemployment and the risks of hunger and food insecurity. If not addressed properly, this may reinforce existing inequalities, break social harmony, and increase tension and turbulence. The economic and social costs of the COVID-19 outbreak are therefore likely to be significant and long-lasting in South Asia.

A Framework for Improving Policy Priorities in Managing COVID-19 Challenges in Developing Countries.

The COVID-19 pandemic has brought unprecedented challenges to societies and threatened humanity and global resilience. All countries are challenged, but low-income and developing countries are facing a more challenging situation than others due to their limited health infrastructure, limited financial and human resources, and limited capacity of governments to respond. Further, the interconnected nature of the COVID-19 pandemic crisis demands an integrated approach and coordinated action, which complicates decision making even more. Identifying the best set of policies and instruments to address COVID-19 challenges, and aligning them with broader social goals will be critically important for sustainable recovery from the pandemic. The key practical challenge facing the policy makers of developing countries is how to prioritize policies to achieve the interconnected goals of managing the health crisis, recovering the economy, and achieving environmental sustainability. We present a framework for identifying and prioritizing policy actions to address the COVID-19 challenges and ensure sustainable recovery. The framework outlines principles and criteria and provides insights into developing shared policy goals, identifying smart strategies, assessing policy compatibility, aligning policy instruments, and factoring sustainability into short and long-term policy decisions. This framework can assist policy makers in linking short and long-term goals, mapping the interactions of different policy options, and assessing anticipated consequences and cross-sectoral implications. This will enable policy makers to prioritize policy choices and allocate limited resources in such a way that they are directed toward actions that generate synergy and co-benefits, have multiplier effects, and achieve interconnected solutions for health, the economy and environment.

Catalyst-Free Regioselective N2 Arylation of 1,2,3-Triazoles Using Diaryl Iodonium Salts.

The widespread application of 1,2,3-triazoles in pharmaceuticals has resulted in substantial interest toward developing efficient postmodification methods. Whereas there are many postmodification methods available to obtain N1-substituted 1,2,3-triazoles, developing a selective and convenient protocol to synthesize N2-aryl-1,2,3-triazoles has been challenging. We report a catalyst-free and regioselective method to access N2-aryl-1,2,3-triazoles in good to excellent yields (66-97%). This scalable postmodification protocol is effective for a wide range of substrates.

Cyclobutane dication, (CH2)4 2+: a model for a two-electron four-center (2e-4c) Woodward-Hoffmann frozen transition state.

The structures of the elusive cyclobutane dication, (CH2)4 2+, were investigated at the MP2/cc-pVTZ and CCSD(T)/cc-pVTZ levels. Calculations show that the two-electron four-center (2e-4c) bonded structure 1 involving four carbon atoms is a minimum. The structure contains formally two tetracoordinate and two pentacoordinate carbons. The non-classical σ-delocalized structure can be considered as a prototype for a 2e-4c Woodward-Hoffmann frozen transition state. The planar rectangular shaped structure 2 with a 2e-4c bond was found not to be a minimum.

Food and nutrition security in the Hindu Kush Himalayan region.

The status of food and nutrition security and its underlying factors in the Hindu-Kush Himalayan (HKH) region is investigated. In this region, one third to a half of children (<5 years of age) suffer from stunting, with the incidence of wasting and under-weight also being very high. The prevalence of stunting, wasting and under-weight in children is particularly high in some mountain areas such as Meghalaya state in India, the western mountains and far-western hills of Nepal, Balochistan province in Pakistan, eastern Afghanistan, and Chin state in Myanmar. Food habits in the HKH region are changing. This has led to a deterioration in traditional mountain food systems with a decline in agrobiodiversity. Factors such as high poverty and low dietary energy intakes, a lack of hygienic environments, inadequate nutritional knowledge, and climate change and environmental degradation are also influencing food and nutrition security in the HKH region. To achieve sustainable food and nutrition security in the mountains, this study suggests a multi-sectoral integrated approach with consideration of nutritional aspects in all development processes dealing with economic, social, agricultural and public health issues. © 2017 Society of Chemical Industry.

Genetic analyses using GGE model and a mixed linear model approach, and stability analyses using AMMI bi-plot for late-maturity alpha-amylase activity in bread wheat genotypes.

Low falling number and discounting grain when it is downgraded in class are the consequences of excessive late-maturity α-amylase activity (LMAA) in bread wheat (Triticum aestivum L.). Grain expressing high LMAA produces poorer quality bread products. To effectively breed for low LMAA, it is necessary to understand what genes control it and how they are expressed, particularly when genotypes are grown in different environments. In this study, an International Collection (IC) of 18 spring wheat genotypes and another set of 15 spring wheat cultivars adapted to South Dakota (SD), USA were assessed to characterize the genetic component of LMAA over 5 and 13 environments, respectively. The data were analysed using a GGE model with a mixed linear model approach and stability analysis was presented using an AMMI bi-plot on R software. All estimated variance components and their proportions to the total phenotypic variance were highly significant for both sets of genotypes, which were validated by the AMMI model analysis. Broad-sense heritability for LMAA was higher in SD adapted cultivars (53%) compared to that in IC (49%). Significant genetic effects and stability analyses showed some genotypes, e.g. 'Lancer', 'Chester' and 'LoSprout' from IC, and 'Alsen', 'Traverse' and 'Forefront' from SD cultivars could be used as parents to develop new cultivars expressing low levels of LMAA. Stability analysis using an AMMI bi-plot revealed that 'Chester', 'Lancer' and 'Advance' were the most stable across environments, while in contrast, 'Kinsman', 'Lerma52' and 'Traverse' exhibited the lowest stability for LMAA across environments.

Dissolution of Sn, SnO, and SnS in a Thiol-Amine Solvent Mixture: Insights into the Identity of the Molecular Solutes for Solution-Processed SnS.

Binary solvent mixtures of alkanethiols and 1,2-ethylenediamine have the ability to readily dissolve metals, metal chalcogenides, and metal oxides under ambient conditions to enable the facile solution processing of semiconductor inks; however, there is little information regarding the chemical identity of the resulting solutes. Herein, we examine the molecular solute formed after dissolution of Sn, SnO, and SnS in a binary solvent mixture comprised of 1,2-ethanedithiol (EDT) and 1,2-ethylenediamine (en). Using a combination of solution (119)Sn NMR and Raman spectroscopies, bis(1,2-ethanedithiolate)tin(II) was identified as the likely molecular solute present after the dissolution of Sn, SnO, and SnS in EDT-en, despite the different bulk material compositions and oxidation states (Sn(0) and Sn(2+)). All three semiconductor inks can be converted to phase-pure, orthorhombic SnS after a mild annealing step (∼350 °C). This highlights the ability of the EDT-en solvent mixture to dissolve and convert a variety of low-cost precursors to SnS semiconductor material.

Chemical Aspects of Astrophysically Observed Extraterrestrial Methanol, Hydrocarbon Derivatives, and Ions.

Astrophysically observed extraterrestrial molecular matter contains, besides hydrogen and water, methane and methanol as the most abundant species. Feasible pathways and chemical aspects of their formation as well as of derived hydrocarbon homologues and their ions (carbocations and carbanions) are discussed on the basis of observed similarities with our studied terrestrial chemistry. The preferred pathway for converting extraterrestrial methane according to Ali et al. is based on CH5(+) and Olah's related nonclassical carbonium ion chemistry. On the basis of the observed higher reactivity of methanol compared with methane in various chemical reactions, a feasible new pathway is proposed for the conversion of extraterrestrial methanol to hydrocarbons, their derivatives, and carbocations together with a possible connection with methonium ion-based chemistry.

Ab initio/GIAO-CCSD(T) (13)C NMR study of the rearrangement and dynamic aspects of rapidly equilibrating tertiary carbocations, C6H13(+) and C7H15(+).

The rearrangement pathways of the equilibrating tertiary carbocations, 2,3-dimethyl-2-butyl cation (C6H13(+), 1), 2,3,3-trimethyl-2-butyl cation (C7H15(+), 5) and 2,3-dimethyl-2-pentyl cation (C7H15(+), 8 and 9) were investigated using the ab initio/GIAO-CCSD(T) (13)C NMR method. Comparing the calculated and experimental (13)C NMR chemical shifts of a series of carbocations indicates that excellent prediction of δ(13)C could be achieved through scaling. In the case of symmetrical equilibrating cations (1 and 5) the Wagner-Meerwein 1,2-hydride and 1,2-methide shifts, respectively, produce the same structure. This indicates that the overall (13)C NMR chemical shifts are conserved and independent of temperature. However, in the case of unsymmetrical equilibrating cations (8 and 9) the Wagner-Meerwein shift produces different tertiary structures, which have slightly different thermodynamic stabilities and, thus, different spectra. At the MP4(SDTQ)/cc-pVTZ//MP2/cc-pVTZ + ZPE level structure 8 is only 90 calories/mol more stable than structure 9. Based on computed (13)C NMR chemical shift calculations, mole fractions of these isomers were determined by assuming the observed chemical shifts are due to the weighted average of the chemical shifts of the static ions.

Additive-dominance genetic model analyses for late-maturity alpha-amylase activity in a bread wheat factorial crossing population.

Elevated level of late maturity α-amylase activity (LMAA) can result in low falling number scores, reduced grain quality, and downgrade of wheat (Triticum aestivum L.) class. A mating population was developed by crossing parents with different levels of LMAA. The F2 and F3 hybrids and their parents were evaluated for LMAA, and data were analyzed using the R software package 'qgtools' integrated with an additive-dominance genetic model and a mixed linear model approach. Simulated results showed high testing powers for additive and additive × environment variances, and comparatively low powers for dominance and dominance × environment variances. All variance components and their proportions to the phenotypic variance for the parents and hybrids were significant except for the dominance × environment variance. The estimated narrow-sense heritability and broad-sense heritability for LMAA were 14 and 54%, respectively. High significant negative additive effects for parents suggest that spring wheat cultivars 'Lancer' and 'Chester' can serve as good general combiners, and that 'Kinsman' and 'Seri-82' had negative specific combining ability in some hybrids despite of their own significant positive additive effects, suggesting they can be used as parents to reduce LMAA levels. Seri-82 showed very good general combining ability effect when used as a male parent, indicating the importance of reciprocal effects. High significant negative dominance effects and high-parent heterosis for hybrids demonstrated that the specific hybrid combinations; Chester × Kinsman, 'Lerma52' × Lancer, Lerma52 × 'LoSprout' and 'Janz' × Seri-82 could be generated to produce cultivars with significantly reduced LMAA level.

Sustainable Food Security in the Mountains of Pakistan: Towards a Policy Framework.

The nature and causes of food and livelihood security in mountain areas are quite different to those in the plains. Rapid socioeconomic and environmental changes added to the topographical constraints have exacerbated the problem of food insecurity in the Hindu Kush-Himalayan (HKH) region. In Pakistan, food insecurity is significantly higher in the mountain areas than in the plains as a result of a range of biophysical and socioeconomic factors. The potential of mountain niche products such as fruit, nuts, and livestock has remained underutilized. Moreover, the opportunities offered by globalization, market integration, remittances, and non-farm income have not been fully tapped. This paper analyzes the opportunities and challenges of food security in Pakistan's mountain areas, and outlines a framework for addressing the specific issues in terms of four different types of area differentiated by agro-ecological potential and access to markets, information, and institutional services.

MP2, CCSD(T), and Density Functional Theory Study of the 2-Butyl Cation: New Insight into the Methyl- and Hydrogen-Bridged Structures.

Using the MP2, CCSD(T), and DFT (B3LYP) methods, the structures and energies of the 2-butyl cation (C4H9(+)) were calculated. Energetically, the C-C hyperconjugated structure 1 and hydrogen-bridged structure 2 were found to be almost identical at all levels. The (13)C NMR chemical shifts of 1 and 2 were computed by the GIAO-CCSD(T) method using different geometries. On the basis of calculated relative energies and calculated (13)C NMR chemical shifts, an equilibrium involving 1 and 2 (in a 50:50 ratio) seemed likely responsible for the experimentally observed (13)C NMR chemical shifts in superacid solutions at -80 °C. However, on the basis of computed and experimental frequencies the hydrogen-bridged structure 2 is most likely responsible for the experimentally observed frequencies in the solid state at -125 °C.

Study of the fluoro- and chlorodimethylbutyl cations.

A comparative study of the 2,3-dimethyl-3-fluoro-2-butyl cation and its chloro analog was carried out by the ab initio/GIAO-CCSD(T) (gauge invariant atomic orbital-coupled cluster with single, double, and perturbative triple excitation) method. The structures and (13)C NMR chemical shifts of the cations were calculated at the GIAO-CCSD(T)/tzp/dz//MP2/cc-pVTZ level. Bridged fluoronium ion 1, carbenium ion 2, and fluorocarbenium ion 3 were found to be minima on the potential energy surface. Bridged fluoronium ion 1, although a minimum on the potential energy surface, is 12.8 kcal/mol less stable than the open chain fluorobutyl cation 3. In contrast to the fluorinated ion, bridged chloronium ion 5 was found to be the lowest energy minimum being 10.6 kcal/mol more stable than ion 6 and 7.4 kcal/mol more stable than ion 7.

Ab initio/GIAO-CCSD(T) calculated 13C-11B NMR chemical shift relationships in isoelectronic hypercoordinate carbonium and boronium as well as carbenium and borenium ions.

Good linear correlations between GIAO-CCSD(T) calculated (11)B NMR chemical shifts of hypercoordinate boronium 1-6b and borenium 7-9b ions and (13)C NMR chemical shifts of the corresponding isoelectronic carbonium 1-6a and carbenium 7-9a ions, respectively, were found.

Comparative study of alkane dications (protonated alkyl cations, C(n)H(2n+2)2+) and their isoelectronic boron cation analogues.

Comparative study of the superelectrophilic alkane dications (C(n)H(2n+2)2+), n = 1-5) and their isoelectronic boron cation analogues was carried out using the ab initio method at the MP2/cc-pVTZ level. The structure, bonding, and relative stability of doubly charged alkane dications and monocharged boron cation analogues are discussed. These studies contribute to our general understanding of the superelectrophilic activation of alkyl cations as well as the electrophilic reactivity of C-H and C-C single bonds.

Octahydriodo diborane (B2H8) and its protonated cations containing five-, six-, and seven-coordinate boron atoms.

Structures of octahydriodo diborane (B(2)H(8)) 1 and its protonated 3, diprotonated 5, triprotonated 6, and tetraprotonated 7 ions were found to be calculationally viable minima at the MP2/cc-pVTZ level of theory. Each structure contains two-electron three-center (2e-3c) bonds. The protonation of 1 to form 3 was found to be strongly exothermic by 176.0 kcal/mol. Subsequent protonation of 3 to form 5 was also found to be exothermic by 28.4 kcal/mol. Further protonation of 5 to form 6 was, however, computed to be endothermic by 122.0 kcal/mol whereas protonation of 6 to form 7 was again highly endothermic by 238.8 kcal/mol. Deprotonation barriers of the ions were also computed.

C7H12(2+): a prototype hexacoordinate carbonium ion.

C(7)H(12)(2+) (1), the prototype hexacoordinate carbonium dication was found to be a viable minimum at the MP2/6-31G** and MP2/cc-pVTZ levels. Structure 1 is a propeller shaped molecule resembling a complex involving a C(2+) with three ethylene molecules resulting in the formation of three two-electron, three-center (2e-3c) bonds. Isomeric structure 2 was found to be 21.8 kcal/mol more stable than structure 1. However, conversion of 1 into 2 through transition structure 3 has a barrier of 5.7 kcal/mol. Related structures 4, 5, and 8 were also located as minima for C(7)H(12)(2+). The isoelectronic boron analogue BC(6)H(12)(+) (10) was also computed to be a minimum at the same level of calculations.

Tri- and tetraprotonated ethane (C2H9(3+) and C2H10(4+)) containing five- and six-coordinate carbons.

Triprotonated ethane (C(2)H(9)(3+)) 4 and tetraprotonated ethane (C(2)H(10)(4+)) 6 were found by ab initio MP2/cc-pVTZ calculations as viable energy minima. Their structure has three and four two-electron three-center (2e-3c) bonds, respectively. In contrast, calculations showed no minimum-energy structure on the potential energy surface of pentaprotonated ethane (C(2)H(11)(5+)). Charge-charge repulsion may approach its limit in this case. Sufficient stabilization of polycations by Schmidbaur-type auration with (C(6)H(5))(3)PAu, an isolobal analogue of H(+), should be possible for the preparation of the polyaurate derivatives of poly protonated ethane allowing their structural study.

Preparation of trifluoromethylated dihydrocoumarins, indanones, and arylpropanoic acids by tandem superacidic activation of 2-(trifluoromethyl)acrylic acid with arenes.

Indanones and coumarins are important intermediates for the convenient synthesis of many pharmaceutical and biologically active compounds. Fluoroorganics play a vital role in the design of very effective therapeutics due to significant enhancenment in their lipophilicity, bioavailability, and fast uptake by the presence of fluorine in these molecules. Herein, we report an efficient one-pot synthesis of trifluoromethylated arylpropanoic acids, indanones, and dihydrocoumarins using Friedel-Crafts alkylation or tandem Friedel-Crafts alkylation-cycloacylation of arenes/phenols with 2-(trifluoromethyl)acrylic acid under superacidic conditions using trifluoromethanesulfonic acid. The results have been rationalized by the structure energy calculations of the involved reaction intermediates using ab initio theoretical methods.