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Analysis of wood transects in a manner that preserves the spatial distribution of the metabolites present is highly desirable to among other things: (1) facilitate ecophysiology studies that reveal the association between chemical make-up and environmental factors or climatic events over time; and (2) investigate the mechanisms of the synthesis and trafficking of small molecules within specialised tissues. While a variety of techniques could be applied to achieve these goals, most remain challenging and impractical. Laser ablation direct analysis in real time imaging-mass spectrometry (LADI-MS) was successfully used to survey the chemical profile of wood, while also preserving the small-molecule spatial distributions. The tree species Entandrophragma candollei Harms, Millettia laurentii DeWild., Pericopsis elata (Harms) Meeuwen, Dalbergia nigra (Vell.) Benth. and Dalbergia normandii BosserR.Rabev were analysed. Several compounds were associated with anatomical features. A greater diversity was detected in the vessels and parenchyma compared with the fibres. Analysis of single vessels revealed that the chemical fingerprint used for timber identification is mainly determined by vessel content. Laser ablation direct analysis in real time imaging-mass spectrometry offers unprecedented opportunities to investigate the distribution of metabolites within wood samples, while circumventing the issues associated with previous methods. This technique opens up new vistas for the discovery of small-molecule biomarkers that are linked to environmental events.

Recently, there has been an increase in the recreational abuse of several psychoactive plants, resulting in the United Nations Office on Drugs and Crime creating a list of "plants of concern." One such material is Sceletium tortuosum and products derived from it. Regulation of these materials is challenging because of their innocuous appearance, the cumbersome sample preparation steps required to render the material into a form amenable to analysis by conventional techniques, the requirement for nuanced sample analysis protocols, and lengthy analysis times. It is demonstrated here that direct analysis in real time-high-resolution mass spectrometry (DART-HRMS) can be used to not only identify S. tortuosum material based on the detection of characteristic biomarkers including hordenine and several mesembrine alkaloids, but also quantify the amount of hordenine present. Using hordenine-d6 as an internal standard, a protocol, validated according to US Food and Drug Administration (FDA) Guidelines for the Development and Validation of Bioanalytical Methods, was devised for the quantification of the psychoactive component hordenine. The method was then applied to the quantification of hordenine in six commercially available products derived from the foliage and stems of S. tortuosum. By this method, the lower limit of quantification (LLOQ) was found to be 1 μg/ml. Observed hordenine concentrations ranged from 0.02738 to 1.071 mg of hordenine per gram of plant material. The developed technique provides an effective and quick means for the detection and quantification of hordenine in S. tortuosum, which can be extended to analysis of other hordenine-containing products.

This study investigated the link between energy consumption (EC), foreign direct investments (FDI), urbanization (URB) and CO2 emissions in the emerging seven (E7) countries for the period 1991 to 2014. The exploration made a methodological contribution by employing modern econometric methods that are robust to the issues of cross-sectional dependence and slope heterogeneity, so as to obtain valid and reliable outcomes. From the results, the panel under consideration was heterogeneous and cross-sectionally correlated. Also, the series were first differenced stationary and cointegrated in the long-run. The DCCEMG and the DCCEPMG estimators were engaged to explore the long-run elastic effects of the covariates on the response variable, and from the results, EC and URB were key promoters of CO2 effusions in the countries. However, FDI mitigated the emanation of CO2 in the nations. Additionally, economic growth (GDP) and population growth (POP) escalated the emittance of CO2 in the E7. On the D-H causality test outcomes, a feedback causality amid POP and CO2 effusions; GDP and CO2 excretions; FDI and CO2 emissivities; and between URB and CO2 secretions were discovered. Finally, a one-way causation from URB to the effluents of CO2 was unfolded. Based on the verdicts, policy suggestions were proposed to help abate the rate of CO2 exudations in the countries.

Lithium-ion batteries, as one of the energy storage devices, has attracted much attention due to its remarkable characteristics. However, they pose safety challenges because of their liquid electrolytes. Solid electrolytes are one of the key candidates to tackle the safety issues in Li-ion batteries. As a solid electrolyte, garnet-type Li7La3Zr2O12 is a promising candidate with its high stability against lithium metal and wide electrochemical window among its counterparts. But, the ionic conductivity is yet to be compared with liquid electrolytes. Hence, doping is still the common strategy to adjust the ionic conductivities. Despite the fact that doping with various elements is well-documented, Lanthanide group element doping is not thoroughly investigated. This research is to study the synthesis of garnet-type Li7La3-xMxZr2O12 (M = Sm, Dy, Er, Yb; x = 0.0–1.0) novel compositions to enlighten the effect of lanthanide group element doping as a function of ionic radius. Results showed that increasing dopant ionic radius improves densification, diminishes Li-ion conduction and, except Yb case, expands the lattice. However, impurity phases formed when the solubility limit is reached, has overall a positive impact on Li-ion conduction. The highest ionic conductivity (0.15 mS/cm) and lowest activation energy (0.18 eV) without impurity phases were obtained from Yb doped LLZO. It was also found that the presence of LiDyO2 improves the ionic conductivity to 0.16 mS/cm.

Heat transport processes through radiation in a dissipative flow of Al2O3 and CuO oil-based nanofluids has been discussed. The equations modeling the flow has been transformed using similarity variables into coupled nonlinear higher order ordinary differential equations. These equations are solved by employing the fourth order Runge-Kutta algorithm and a shooting technique. The results for the embedded parameters were tabulated and depicted graphically. The study revealed that oil-based nanofluid of CuO has a better rate of heat transfer than Al2O3 oil-based nanofluid with increased radiation. Thus, the study concluded that CuO oil-based nanofluid has a superior heat transfer characteristic and thus preferred for radiation hardening.

This study presents the detailed contrastive potential of Bacillus licheniformis gram positive and Bacillus mucilaginosus Krassilnikov gram negative for Cr (VI) remediation from water. The results ...

The pro-poor growth and environmental sustainability are the twin agendas widely discussed in environmental science literature. The technology-embodied growth helps to attain both agendas through knowledge sharing and technology transfer, which trickle down to the poor income group and improve their living standards. Hence, the role of information and communication technologies (ICTs) is deemed crucial in boosting economic growth and is under deep consideration to establish its role in reducing poverty and environmental pollution. The current study examines the long-run relationship between ICTs, poverty reduction, and ecological degradation in Pakistan using time series data from 1975-2018. The short- and long-run parameter estimates were obtained through the Autoregressive Distributed Lag (ARDL) model for robust inferences. The results substantiate the inverted U-shaped Environmental Kuznets Curve relationship between income and emissions with a turning point at US$1000 in the short-run and US$800 in the long-run. The results confirmed the decisive intervention of ICTs factors in the poverty reduction, i.e., computer communications and mobile-telephone-broadband subscriptions support to reduce poverty incidence with the mediation of inbound FDI in a country. As far as income inequality is concerned, it shows that computer services support minimizing income inequality via a channel of high-technology exports in a country. The technology embodied emissions verified in the long-run, where mobile-telephone-broadband subscriptions increase carbon emissions. Finally, mobile-telephone-broadband subscriptions and inbound FDI both are significant contributors to amplify the country's economic growth. The results conclude that poverty reduction and environmental sustainability agenda are achieved by developing green ICT infrastructure in a country.

The relevance of carrying out marine warranty surveys (MWS) as mandatory insurable practice in mitigating associated operational risks within the offshore oil and gas industry, during the Covid-19 crises, was examined against the potential health risk and the various Covid-19 restrictions resulting from newly formed regulations. The health risk concerns to the surveyor and the impact of the Covid-19 policy restrictions for the surveyor’s business measured are against the risk of excluding MWS in assessing the suitability of procedures, analyses, and vessels involved in typical offshore marine operations. The purpose of any MWS undertakings ensures that all risks in operations, with potential to destroy property, life, and environment, are minimized—if not eliminated. A series of remote interviews across Africa and direct field observations were respectively conducted at the Takoradi port to develop an understanding of the MWS service product, to ascertain the conditions resulting from current challenges, and to determine contingencies and innovations to ensure full service. The study finds MWS service as paramount to the energy industry with its range of risk control checks for high-value assets and operations. Surveyors demonstrated high-levels of awareness for Covid-19 crises and regulatory policies while in adherence but noted challenges of high-cost and delays as by-products of the restrictions. Surveyors deemed site attendances as crucial in their practice at all time, though recognized the several social and technologically innovative approaches adopted industry-wide to facing the pandemic. The study highlights the need for ‘essential worker’ status and the introduction of innovative insurance packages. Supplementary Information The online version contains supplementary material available at 10.1007/s40152-021-00220-7.

This paper explored the link between energy consumption and carbon emissions in North Africa through an Environmental Kuznets Curve (EKC) framework. Panel data extracted from the data base of the World Development Indicators (WDI) for the period 1990–2015 were used for the study. In the analytical process, more modern econometric techniques that are vigorous to cross-sectional dependence and slope heterogeneity were employed. From the findings, the studied panel was heterogeneous and cross-sectionally dependent. Also, all the series were first differenced stationary and cointegrated in the long-run. Further, the Augmented Mean Group (AMG) and the Common Correlated Effects Mean Group (CCEMG) estimators affirmed energy consumption as a significantly positive determinant of CO2 emissions. Also, urbanization and foreign direct investments promoted the emanation of CO2 in the block. Finally, an inverted U-shaped relationship between economic growth and CO2 emissions was disclosed, validating the EKC hypothesis. On the causal connections amid the series, there was a bidirectional causality between energy consumption and CO2 emissions, economic growth and CO2 emanations, and urbanization and CO2 emissions. Lastly, a unidirectional causality from foreign direct investments to CO2 emissions was unfolded. Based on the findings, it was recommended among others that, the countries should advocate for the consumption of renewable energies like wind, solar, hydro, biomass and biofuels among others. This will help to reduce the rate of emissions in the bloc.

We examined the effect of environmental disclosure on environmental performance for listed mining companies in China. Our analysis used China's Environmental Information Disclosure Degree (EIDD) and the Chinese Securities Regulatory Commission's disclosure guidelines to propose the Environmental Information Disclosure Index. Majority of previous studies on environmental disclosures focused on a particular company or city or province. Few studies considered a whole sector of a country. Among the few studies that considered a whole industry, none of such studies considered the mining industry. In addition, our study employed a recent environmental disclosure index and modified a recent index for environmental performance for the empirical analysis making our study unique. We also employed vigorous reliability and robustness test to ensure that our findings are valid and can be used by policy-makers. Using panel data for thirty-four mining companies from both Shanghai and Shenzhen Stock Exchange for the period 2000-2018, our cointegration estimation analysis concluded that corporate environmental performance and environmental information disclosure has a positive and significant relationship at a 1% level. Trend analysis revealed that mining companies comply with environmental information disclosure in China. This was seen from the great improvement in the environmental disclosure for mining companies between 2008 and 2010 after the enforcement of EIDD. Our results contribute to the previous literature and open the way for further studies on industry level in other countries.

This study examined the nexus between urbanization and carbon emissions in West Africa. Second-generation econometric techniques that are robust to cross-sectional dependence and slope heterogeneity were used for the study. From the Pesaran–Yamagata homogeneity test, the slope coefficients were heterogeneous in nature. Also, the Breusch–Pagan LM test, the Pesaran scaled LM test, bias-corrected LM test, Pesaran CD test and the Friedman’s test confirmed the studied panels to be cross-sectionally dependent. Further, the CADF and the CIPS unit root tests established the variables to be first-differenced stationary. Additionally, the Westerlund and Edgerton bootstrap cointegration test and the Pedroni residual cointegration test affirmed the series to be cointegrated in the long run. The Driscoll–Kraay standard errors regression estimator was employed to examine the long-run equilibrium relationship amid the series, and from the results, urbanization had a significantly positive influence on CO2 emissions in all the three panels. Also, economic growth had a materially positive effect on CO2 emissions, while renewable energy consumption had a substantially negative impact on CO2 emissions in all the panels. The causal connections amid the series were finally explored through the Dumitrescu–Hurlin panel causality test, and the discoveries were a bit varied across the various panels. Policy recommendations are further discussed.

Securing land rights and the rationalisation of the debate on formalisation of land rights through titling have been the focus of many scholars for some time now. At least, there is consensus among most scholars that land registration is one of the ways of addressing these issues and that current land registration system in most developing countries needs reforms. This paper examines the design and implementation processes of land registration reforms in Ghana. Using the Greater Accra Regional Lands Commission as a case study and institutional design theories, the article analysed how land registration reforms were design and implemented. The paper shows that the design strategies for the reforms were harmonisation of policies and laws and organisation restructuring at the organisational and process levels, but staff resistance to change led to implementation flaws. The paper recommends that institution design of land registration reforms must be combined with the theory of change where all staff are taken through the new organisation’s work ethics and attitudinal change processes adequately.

The concept of transformational adaptation is increasingly becoming a buzzword in the field of political ecology or the emerging sub-field of climate change governance. However, what kind of adaptation to climate impact can best be described as transformational? This question is not fully answered, since the concept is still at an embryonic stage of life. In this article, the concept is diagnosed bottom-up—exclusively from the perspective of adaptation project beneficiaries. The question is asked: what kind of adaptation project intervention and outcome do you consider transformational? How is transformational adaptation different from incremental adaptation? Through an interpretive research paradigm, some selected adaptation projects from Ghana were used as a case study. According to the interviewees, climate change adaptation interventions that create a systematic shift in livelihood to a more sustainable option, create equitable power structures that influence adaptive decision-making, minimise vulnerability and create opportunity for scaling up could be described as transformational. Specifically, it was found that project beneficiaries consider transformational adaptation strategies that encourage and support a total shift in livelihood (e.g., from rice farming to snail rearing) as transformational. On the basis of the data, the study concludes, though with some cautious optimism, that transformational adaptation could spur innovations and diffusion of ideas and create a path for poverty reduction.

The novel effect of direct current generation by carbon nanotubes with hot electron injection which may arise due to an electromagnetic radiation with commensurate frequencies has been theoretically investigated using the semiclassical Boltzmann kinetic equation with relaxation time assumed constant. The nonlinearity of the current voltage characteristics and the chiral effects have been considered. We note that the direct current is a result of the strong nonprabolicity of the energy of the carbon nanotubes for the case where it Bloch oscillates. It is shown that the novel expression for the direct current generation strongly and significantly dependence on the hot electron injection rate, which leads to strong oscillatory behavior and the shift of the regions of absolute negative conductivity from low to higher dimensionless amplitude β values with increasing injection rate. We predict that carbon nanotubes with hot electron injection may be useful for generation of direct current.

This study examined the nexus between carbon emissions, renewable energy consumption, and the economic growth of West African countries for the period 1990 to 2018. To be able to uncover reliable and valid findings, more robust panel estimation methods were employed for the study. From the heterogeneity and cross-sectional dependence tests, the study’s panels were heterogeneous and cross-sectionally dependent. Also, all the series were non-stationary at levels, but gained stationarity after first difference. Further, the Fisher test and the Westerlund and Edgerton bootstrap test found the variables to be cointegrated in the long run. The CCEMG and the DCCEMG estimators were used to explore the long-run equilibrium relationship amid the series, and from the results of the whole sample, CO2 emissions and renewable energy consumption (REC) had no vital influence on economic growth (GDP) in both estimators. However, the results were a bit different in the sub-panels. Also from the whole sample, control variables urbanization (URB) and population growth (POP) had no material effect on GDP in both estimators. The results were, however, dissimilar in the sub-panels. Finally, the Dumitrescu-Hurlin test was employed to examine the causalities amid the series, and the results were diverse in the various panels. Policy recommendations are further discussed.

The utilization of entomological specimens such as larvae (maggots) for the estimation of time since oviposition (i.e., egg laying) for post mortem interval determination, or for estimation of time since tissue infestation (in investigations of elder or child care neglect and animal abuse cases), requires accurate determination of insect species identity. Because the larvae of multiple species are visually highly similar and difficult to distinguish, it is customary for species determination of maggots to be made by rearing them to maturity so that the gross morphological features of the adult can be used to accurately identify the species. This is a time-consuming and resource-intensive process which also requires that the sample be viable. The situation is further complicated when the maggot mass being sampled is comprised of multiple species. Therefore, a method for accurate species identification, particularly for mixtures, is needed. It is demonstrated here that direct analysis in real time-high resolution mass spectrometric (DART-HRMS) analysis of ethanol suspensions containing combinations of maggots representing Calliphora vicina, Chrysomya rufifacies, Lucilia coeruleiviridis, L. sericata, Phormia regina, and Phoridae exhibit highly reproducible chemical signatures. An aggregated hierarchical conformal predictor applied to a hierarchical classification tree that was trained against the DART-HRMS data enabled, for the first time, multispecies identification of maggots in mixtures of two, three, four, five, and six species. The conformal predictor provided label specific regions with confidence limits between 80 and 99% for species identification. The study demonstrates a novel, rapid, facile, and powerful approach for identification of maggot species in field-derived samples.

Solid waste collection constitutes 60-80% of the total solid waste management cost. Reduction of solid waste collection cost can be achieved through route optimization in a geographic information system (GIS) environment. The purpose of this study was to generate optimized routes for solid waste collection on Kwame Nkrumah University of Science and Technology campus in Kumasi, Ghana. The study modelled the existing routes for a complete collection cycle using travel time criteria and generated optimized routes for same using an ArcGIS software. Validation of the optimized outcome (travel distance and travel time) was done by subjecting the solid waste collection trucks to the optimized routes. The results from the study showed significant reduction in total travel time from 1,000.75 mins to 855.70 mins for existing and optimized routes respectively, translating into saving of 14.5%. Total travel distance significantly reduced from 367.30 km to 334.20 km for existing and optimized routes respectively, representing saving of 9.0%. Significant savings in travel time and travel distance have implications on reduction of fuel and maintenance cost of institutional solid waste collection trucks. The results indicate that the application of GIS-based route optimization in solid waste collection can provide significant improvement in reduction of operating cost.

Poor sanitation, water and hygiene are related to several and severe negative implications on health and the environment. In recent years, community-based management of water and sanitation facilities have been linked to improving access to these facilities. Ghana is also on its way to achieving the Strategic Development Goals (SDGs) for access to potable water. However, several studies have found gaps between increased access to water and sanitation in Ghana and have shown that more than a third of the water supply facilities breakdown within the first year of their inauguration. Despite these problems, Water and Sanitation Management Teams (WSMTs) have contributed immensely to the attainment of the SDGs. This study assessed the roles of fifteen communities in maintaining the momentum towards the SDGs. The study revealed that twelve communities (80%) out of fifteen have WSMTs in place. All the communities have water facilities but only four (27%) have access to toilet facilities and the WSMTs working effectively to provide good services to their community members. The existence and effectiveness of WSMTs aided in providing reliable water supply, periodic maintenance of Water Supply Systems (WSSs), less breakdown of WSSs, timely releasing of funds, effective monitoring and quick responses in repairing broken down facilities. However, these WSMTs faced challenges such as the inability to generate funds for the rehabilitation of WSSs, team members lacked skills in water and sanitation management, poor record-keeping and cooperation among the committee and community members in the delivery of their services. It is recommended that WSMTs should be given managerial and maintenance training on WASH projects before they are handed over to them, and community members should be encouraged to cooperate with the WSMTs. Key words: Community-based, water, sanitation, management, teams, sustainable, development.

RATIONALE Classified by the UNODC as a top 20 plant of concern, Piper methysticum (also known as Kava) is being increasingly abused recreationally for its mind-altering effects. It is of significant forensic relevance to establish methods to rapidly identifyand quantify psychoactive compounds, especially those yet to be scheduled ascontrolled substances and which have exhibited various noteworthy health concerns. METHODS Direct analysis in real time high-resolution mass spectrometry (DART-HRMS) demonstrated the ability to detect a range of kavalactones in Pipermethysticum derived products and plant material with no sample preparation. Inaddition, a validated method using calibration curves developed with a deuteratedinternal standard was used for the quantification of the psychoactive moleculeyangonin in various products. RESULTS DART-HRMS detected the protonated masses of six major kavalactonesand three flavokavains in 18 commercial Kava products. A method consistent withFDA validation guidelines was established for the quantification of yangonin in thevarious complex matrices. Implementation of this method, with an LLOQ of 5 mg/mL, enabled successful quantification of yangonin in 16 Kava products.Concentrations for solid products ranged from 2.71 to 8.99 mg/g, while that forliquid products ranged from 1.03 to 4.59 mg/mL. CONCLUSIONS Rapid identification and quantification of psychoactive smallmolecules in plant material can be accomplished using a validated DART-HRMSprotocol. This work illustrates an approach to qualitative and quantitative analysesof a wide variety of complex matrices derived from plants, and demonstrates thatthe commercially available products analyzed are P. methysticum derived and docontain psychoactive yangonin at quantifiable levels.

It is challenging to achieve highly efficient thermoelectric materials due to the conflicts between thermopower (Seebeck coefficient) and electrical conductivity. These parameters are the core factors defining the thermoelectric property of any material. Here, we report the use of isovalent substitution as a tool to decouple the interdependency of the Seebeck coefficient and the electrical properties of cerium-doped bismuth selenide thermoelectric material. With this strategy, we can achieve a simultaneous increase in both the electrical conductivity and the Seebeck coefficient of the material by tuning the concentration of cerium doping, due to formation of neutral impurities and consequently the improvement of carrier mobility. Our theoretical calculation reveals a downward shift of the valence band with cerium concentration, which influences the thermoelectric enhancement of the synthesized materials. Finally, an order of magnitude enhancement of the figure of merit is obtained due to isovalent substitution, thus providing a new avenue for enhancing the thermoelectric performance of materials.

Purpose This paper aims to provide empirical evidence on the El Nino and its effects on maize production in three municipalities: Ejura, Techiman and Wenchi in the transitional zone of Ghana. Using a mixed approach, the study details the effects of the El Nino on rainy season characteristics, particularly, rainfall amounts and distribution, onset and cessation of rains, duration of the rainy season and total seasonal rainfall and how it impacted smallholder maize production. Design/methodology/approach The study used a mixed method approach in collecting and analyzing data. For stronger evidence building, (Creswell, 2013) the authors combined interviews and focus group discussions (FGD) to collect the qualitative data. Semi-structured questionnaires were administered to extension officers, management information system officers and other relevant personnel of the Ministry of Agriculture in the three municipalities. Six FGD’s were held for maize farmers in six communities in all three municipalities. Findings The study shows that the 2015 El Nino had dire consequences on farm yields, subsequently affecting farmer’s incomes and livelihoods. The study further finds that complex socio-cultural factors, some unrelated to the El Nino, aggravated the effects on maize farmers. These include the lack of adequate climatic information, predominance of rain-fed farming, a lack of capacity to adapt and existing levels of poverty. Originality/value The study recommends inter alia, appropriate use of seasonal rainfall forecasting to enhance better farming decision-making and the development of elaborate climate variability interventions by national and local agencies.

Plants that produce atropine and scopolamine fall under several genera within the nightshade family. Both atropine and scopolamine are used clinically, but they are also important in a forensics context because they are abused recreationally for their psychoactive properties. The accurate species attribution of these plants, which are related taxonomically, and which all contain the same characteristic biomarkers, is a challenging problem in both forensics and horticulture, as the plants are not only mind-altering, but are also important in landscaping as ornamentals. Ambient ionization mass spectrometry in combination with a hierarchical classification workflow is shown to enable species identification of these plants. The hierarchical classification simplifies the classification problem to primarily consider the subset of models that account for the hierarchy taxonomy, instead of having it be based on discrimination between species using a single flat classification model. Accordingly, the seeds of 24 nightshade plant species spanning 5 genera (i.e. Atropa, Brugmansia, Datura, Hyocyamus and Mandragora), were analyzed by direct analysis in real time-high resolution mass spectrometry (DART-HRMS) with minimal sample preparation required. During the training phase using a top-down hierarchical classification algorithm, the best set of discriminating features were selected and evaluated with a partial least square-discriminant analysis (PLS-DA) classifier to discriminate and visualize the data. The method yields species identity through a class hierarchy, and reveals the most significant markers for differentiation. The overall accuracy of the approach for species identification was 95% and 96% using 100X bootstrapping validation and test samples respectively. The method can be extended for the rapid identification of an infinite number of plant species.

Inappropriate drainage and agricultural development on tropical peatland may lead to an increase in methane (CH4) emission, thus expediting the rate of global warming and climate change. It was hypothesized that water table fluctuation affects CH4 emission in pineapple cultivation on tropical peat soils. The objectives of this study were to: (i) quantify CH4 emission from a tropical peat soil cultivated with pineapple and (ii) determine the effects of water table depth on CH4 emission from a peat soil under simulated water table fluctuation. Soil CH4 emissions from an open field pineapple cultivation system and field lysimeters were determined using the closed chamber method. High-density polyethylene field lysimeters were set up to simulate the natural condition of cultivated drained peat soils under different water table fluctuations. The soil CH4 flux was measured at five time intervals to obtain a 24 h CH4 emission in the dry and wet seasons during low- and high-water tables. Soil CH4 emissions from open field pineapple cultivation were significantly lower compared with field lysimeters under simulated water table fluctuation. Soil CH4 emissions throughout the dry and wet seasons irrespective of water table fluctuation were not affected by soil temperature but emissions were influenced by the balance between methanogenic and methanotrophic microorganisms controlling CH4 production and consumption, CH4 transportation through molecular diffusion via peat pore spaces, and non-microbial CH4 production in peat soils. Findings from the study suggest that water table fluctuation at the soil–water interface relatively controls the soil CH4 emission from lysimeters under simulated low- and high-water table fluctuation. The findings of this study provide an understanding of the effects of water table fluctuation on CH4 emission in a tropical peatland cultivated with pineapple.

The purpose of this study was to examine the nexus amid economic growth, energy consumption and carbon emissions in G20 countries for the period 1992 to 2014. In order to obtain valid and reliable outcomes, more robust econometric techniques were employed. From the results, the studied panel was heterogeneous and cross-sectionally dependent. Also, the series of observed variables were first-differenced stationary and co-integrated. The key findings from the CCEMG and the AMG regression estimators adopted showed that economic growth and energy consumption promoted the emission of carbon in the countries. In addition, urbanization and foreign direct investments as control variables escalated the rate of the countries’ CO2 emissions. From the discoveries of the Dumitrescu and Hurlin panel causality test, a feedback causality between economic growth and CO2 emissions; energy consumption and CO2 emissions; and between urbanization and CO2 emissions were correspondingly unveiled. Howerver, a one-way caual link was evidenced from foreign direct investments to CO2 emissions. This exploration is vital because it will propel the countries to formulate policies that could help them to minimize their dependence on environmentally unfriendly energy sources, while promoting the usage of clean energies like solar, wind, biogas, biomass and hydropower among others. The study is also pertinent because it will aid the countries to plan, organize and implement environmental policies in compliance to their macroeconomic objectives. When this is accomplished, energy conservation policies implemented to minimize the emanation of CO2 will improve the countries’ economic growth.

The United Nations Office on Drugs and Crime has designated several "legal highs" as "plants of concern" because of the dangers associated with their increasing recreational abuse. Routine identification of these products is hampered by the difficulty in distinguishing them from innocuous plant materials such as foods, herbs, and spices. It is demonstrated here that several of these products have unique but consistent headspace chemical profiles and that multivariate statistical analysis processing of their chemical signatures can be used to accurately identify the species of plants from which the materials are derived. For this study, the headspace volatiles of several species were analyzed by direct analysis in real-time high-resolution mass spectrometry (DART-HRMS). These species include Althaea officinalis, Calea zacatechichi, Cannabis indica, Cannabis sativa, Echinopsis pachanoi, Lactuca virosa, Leonotis leonurus, Mimosa hositlis, Mitragyna speciosa, Ocimum basilicum, Origanum vulgare, Piper methysticum, Salvia divinorum, Turnera diffusa, and Voacanga africana. The results of the DART-HRMS analysis revealed intraspecies similarities and interspecies differences. Exploratory statistical analysis of the data using principal component analysis and global t-distributed stochastic neighbor embedding showed clustering of like species and separation of different species. This led to the use of supervised random forest (RF), which resulted in a model with 99% accuracy. A conformal predictor based on the RF classifier was created and proved to be valid for a significance level of 8% with an efficiency of 0.1, an observed fuzziness of 0, and an error rate of 0. The variables used for the statistical analysis processing were ranked in terms of the ability to enable clustering and discrimination between species using principal component analysis-variable importance of projection scores and RF variable importance indices. The variables that ranked the highest were then identified as m/z values consistent with molecules previously identified in plant material. This technique therefore shows proof-of-concept for the creation of a database for the detection and identification of plant-based legal highs through headspace analysis.

The mechanisms, energetics, and kinetics of the gas-phase reactions of terrestrial plant-derived dimethyl thiosulfinate (DMTS) with the atmospheric oxidants OH and Cl radicals were investigated using high-level ab initio calculations. The results show that the addition of OH and Cl radicals to the sulfinyl [-S(═O)] of DMTS, followed by S(═O)-S single bond cleavage to form methanesulfinic acid + CH3S• and methanesulfinyl chloride + CH3S•, respectively, are the more dominant reactions. The barrier heights for the reactions with OH and Cl radicals were found to be -5.6 and -12.7 kcal/mol relative to the energies of the starting reactants, respectively, when computed at the CCSD(T)/aug-cc-pVTZ//M06-2X/6-311++G(3df,3pd) level of theory. The rate constants for all possible pathways of DMTS + •OH/•Cl reactions were investigated using the MESMER kinetics code over the temperature range between 200 and 300 K. The calculated global rate constants for the DMTS + •OH and DMTS + •Cl reactions at 300 K were found to be 1.42 × 10-11 and 3.72 × 10-11 cm3 molecule-1 s-1, respectively. In addition, the thermochemistry of all possible paths and branching ratios was determined. The atmospheric chemistry implications of the DMTS + •OH/•Cl reactions are discussed.

Carbon-bearing boron hydrides, also known as carboranes, are polyhedral clusters composed of hydrogen, boron, and carbon and are closely related to boranes. Because of their esthetically pleasing symmetry as well as unusual chemical properties, carboranes have attracted immense interest. Studies over the past 40 years have revealed them to have chemical features that make them useful in a number of specialized applications such as conducting organic polymers, nuclear waste remediation, and as liquid crystalline materials. It has also been shown that carboranes can be used as boron delivery agents for boron neutron capture therapy against cancer. While a number of strides have been made in synthesizing these molecules, their characterization by NMR spectroscopy is challenging due to boron–boron and boron–hydrogen coupling. This gives rise to broad and unresolved peaks and makes peak assignment difficult and often based on best guesses. NMR structural characterization studies of carborane compounds are sparse, dated, and often performed at low resolution. This report provides a detailed structural characterization of an m-carborane derivative, featuring high-resolution multi-dimensional NMR spectroscopy (2-D 1H–1H, 2-D 11B–11B, 2-D 11B–1H, and 2-D 13C–1H). The asymmetry of the carborane cluster (a consequence of substitution at one of the two cluster carbons) adds a dimension of complexity to the spectra, whose peaks could be assigned nevertheless due to their high resolution.

Interpretation of geochemical data based primarily on elemental concentrations often lead to ambiguous results due to multiple potential sources including mineral weathering, atmospheric input, bio ...

Sustaining soil health cannot be divorced from sustainable crop production. Organic, or natural, farming is being promoted as a good sustainable agriculture practice. One aspect of organic farming that could significantly enhance and sustain soil health, soil quality, and crop productivity is the use of high-quality soil conditioners or organic amendments produced from agro-wastes. Thus, the objective of this study was to characterize the chemical and biological properties of selected agro-wastes with potential for use as organic amendments in sustaining soil health. Standard procedures were used to produce and characterize the soil conditioners, namely fermented plant juice (FPJ), fermented fruit juice (FFJ), palm kernel shell (PKS) biochar, and kitchen waste (KW) compost. The fermented juices (FPJ and FFJ), PKS biochar, and KW compost exhibited chemical and biological properties with good potential as soil conditioners or organic amendments to sustain soil health. The fermented juices contained important microbes that can solubilize P and K in soil for crop use. The high pH and C content of the biochar and compost and the high cation exchange capacity of the biochar are good indicators of the potential of these materials to sustain soil health in terms of the liming effect of acid soils, nutrient and water retention, nutrient reserves, and a suitable habitat for microbial life. Moreover, the organic amendments contain reasonable amounts of macro- and micro-nutrients, which could be released to increase soil fertility. Despite these potential benefits, field application of these organic amendments is necessary to evaluate their effects on soil health and crop production in both the short and long term.

Farming systems on peat soils are novel, considering the complexities of these organic soil. Since peat soils effectively capture greenhouse gases in their natural state, cultivating peat soils with annual or perennial crops such as pineapples necessitates the monitoring of nitrous oxide (N2O) emissions, especially from cultivated peat lands, due to a lack of data on N2O emissions. An on-farm experiment was carried out to determine the movement of N2O in pineapple production on peat soil. Additionally, the experiment was carried out to determine if the peat soil temperature and the N2O emissions were related. The chamber method was used to capture the N2O fluxes daily (for dry and wet seasons) after which gas chromatography was used to determine N2O followed by expressing the emission of this gas in t ha−1 yr−1. The movement of N2O horizontally (832 t N2O ha−1 yr−1) during the dry period was higher than in the wet period (599 t N2O ha−1 yr−1) because of C and N substrate in the peat soil, in addition to the fertilizer used in fertilizing the pineapple plants. The vertical movement of N2O (44 t N2O ha−1 yr−1) was higher in the dry season relative to N2O emission (38 t N2O ha−1 yr−1) during the wet season because of nitrification and denitrification of N fertilizer. The peat soil temperature did not affect the direction (horizontal and vertical) of the N2O emission, suggesting that these factors are not related. Therefore, it can be concluded that N2O movement in peat soils under pineapple cultivation on peat lands occurs horizontally and vertically, regardless of season, and there is a need to ensure minimum tilling of the cultivated peat soils to prevent them from being an N2O source instead of an N2O sink.

CCSD(T)/aug-cc-pVTZ//M06-2X/aug-cc-pVTZ calculations were performed on the addition of amines [i.e. ammonia (NH3), methyl amine (MA), and dimethyl amine (DMA)] to carbonyl sulfide (OCS), followed by transfer of the amine H-atom to either the S-atom or O-atom of OCS, assisted by a single water (H2O) or a formic acid (FA) molecule, leading to the formation of the corresponding carbamothioic S- or O acids. For the OCS + NH3 and OCS + MA reactions with or without the H2O or FA, very high barriers were observed, making these reactions unfeasible. Interestingly, the barrier heights for the OCS + DMA reaction, involving H-atom transfer to either the S-atom or O-atom of OCS and assisted by a FA, were found to be −4.2 kcal mol−1 and −3.9 kcal mol−1, respectively, relative to those of the separated reactants. The barrier height values suggest that FA lowers the reaction barriers by ∼28.4 kcal mol−1 and ∼35.9 kcal mol−1 compared to the OCS + DMA reaction without the catalyst. Rate coefficient calculations were performed on the OCS + DMA reaction both without a catalyst, and assisted by a H2O and a FA molecule using canonical variational transition state theory and small curvature tunneling at the temperatures between 200 and 300 K. The rate data show that the OCS + DMA + FA reaction proceeds through H-atom transfer to the S-atom of OCS, which was found to be ∼103–1011 and 103–1010 times faster than the OCS + DMA and OCS + DMA + H2O reactions, respectively, in the studied temperature range. For the same temperature range, the rate of the OCS + DMA + FA reaction was found to be ∼108–1016 and 103–1012 times faster than the OCS + DMA and OCS + DMA + H2O reactions in which H-atom transfer to the O-atom of OCS occurred. This suggests that the OCS + DMA reaction that is assisted by FA is more efficient than the H2O assisted reaction. In addition, the rate of the OCS + DMA + FA reaction was found to be ∼1010 times slower than the OCS + ˙OH reaction at 298 K. This clarifies that the OCS + DMA + FA reaction may be feasible for the atmospheric removal of OCS under night-time forest fire conditions when the OCS and DMA concentrations are high and the ˙OH concentration is low.

A new method termed efficient data reduction-multivariate curve resolution (EDR-MCR) has been devised for classification of high-dimensional data. The method introduces the coupling of EDR and MCR as a new strategy for data splitting, variable selection, and supervised classification of high dimensionality data. The method reduces data dimensionality and selects the training set using principal component analysis (PCA) and convex geometry prior to data classification. Then, the reduced data are categorized using an MCR model, in which numerical constraints are imposed to resolve the data into classes and readily interpretable pure component signal weights. The performance of the EDR and supervised MCR methods were tested for their ability to enable discrimination between the constituents of two benchmark and two high-dimensional data sets. The results were compared with the output of the application of different data splitting methods including iterative random selection (IRS), Kennard-Stone (KS), and discrimination methods including partial least-squares-discriminant analysis (PLS-DA) and the ensemble-learning frameworks of linear discriminant analysis (LDA), k-nearest neighbors (KNN), classification and regression trees (CART), and support vector machine (SVM). Overall, EDR resulted in comparable results with other data splitting methods despite the small size of the training set samples that it created. The proposed MCR approach, in comparison with other commonly used supervised techniques, has the advantages of speed in implementation, tuning of fewer parameters, flexibility in the analysis of data characterized by low sample numbers and class imbalances, improved accuracy from the inclusion of additional system information in the form of numerical constraints, and the ability to resolve pure components signal weights.

The working electrode’s surface property is crucial to cell adhesion and signal collection in electric cell-substrate impedance sensing (ECIS). To date, the indium tin oxide (ITO)-based working electrode is of interest in ECIS study due to its high transparency and biocompatibility. Of great concern is the impedance signal loss, distortion, and data interpretation conflict profoundly created by the movement of multiple cells during ECIS study. Here, a carboxyl-terminated ITO substrate was prepared by stepwise surface amino silanization, with N-hydroxy succinimide (NHS) and 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) treatment, respectively. We investigated the stepwise changes in the property of the treated ITO, cell-substrate adhesion, collective cell mobility, and time course of change in absolute impedance from multiple Chinese hamster ovary (CHO) cells [(Δt-Δ|Z|)CELLS]. The carboxyl-terminated ITO substrate with a surface roughness of 6.37 nm shows enhanced conductivity, 75% visible light transparency, improved cell adherence, reduced collective cell migration speed by approximately twofold, and diminished signal distortion in the [(Δt-Δ|Z|)CELLS]. Thus, our study provides an ITO surface-treatment strategy to reduce multiple cell movement effects and to obtain essential cell information from the ECIS study of multiple cells through undistorted (Δt-Δ|Z|)CELLS.

The focus of this exploration was to examine the linkage between trade openness and CO2 effusions in the developing eight (D8) countries. An unbalanced panel dataset spanning the period 1990 to 2016 was employed for the study's analysis. From the results, the studied panel was heterogeneous and cross-sectionally correlated. Also, all the series gained stationarity after first difference and were materially cointegrated in the long run. The elastic effects of the input variables on the output variable were explored through the DCCEMG estimator, with the support of the AMG and the CCEMG estimators. From the results, trade openness increased CO2 emanations in the D8. Also, economic growth, energy consumption, and financial development promoted CO2 secretions in the nations; however, foreign direct investments mitigated the excretion of CO2 in the countries. On the causal connections amid the series, there was a bidirectional causality between trade openness and CO2 emanations. Also, a one-way causal movement from energy consumption, foreign direct investments, and financial development to CO2 effluents was discovered. Based on the findings, it was recommended among others that effective trade policies that could enhance the transfer of cleaner technologies to the countries should be formulated.

Climate change adaptation responses are being developed and delivered in many parts of the world in the absence of detailed knowledge of their effects on public health. Here we present the results of a systematic review of peer-reviewed literature reporting the effects on health of climate change adaptation responses in low- and middle-income countries (LMICs). The review used the ‘Global Adaptation Mapping Initiative’ database (comprising 1682 publications related to climate change adaptation responses) that was constructed through systematic literature searches in Scopus, Web of Science and Google Scholar (2013–2020). For this study, further screening was performed to identify studies from LMICs reporting the effects on human health of climate change adaptation responses. Studies were categorised by study design and data were extracted on geographic region, population under investigation, type of adaptation response and reported health effects. The review identified 99 studies (1117 reported outcomes), reporting evidence from 66 LMICs. Only two studies were ex ante formal evaluations of climate change adaptation responses. Papers reported adaptation responses related to flooding, rainfall, drought and extreme heat, predominantly through behaviour change, and infrastructural and technological improvements. Reported (direct and intermediate) health outcomes included reduction in infectious disease incidence, improved access to water/sanitation and improved food security. All-cause mortality was rarely reported, and no papers were identified reporting on maternal and child health. Reported maladaptations were predominantly related to widening of inequalities and unforeseen co-harms. Reporting and publication-bias seems likely with only 3.5% of all 1117 health outcomes reported to be negative. Our review identified some evidence that climate change adaptation responses may have benefits for human health but the overall paucity of evidence is concerning and represents a major missed opportunity for learning. There is an urgent need for greater focus on the funding, design, evaluation and standardised reporting of the effects on health of climate change adaptation responses to enable evidence-based policy action.

The vulnerability of semi-arid basin aquifers to long-term salinization due to the dissolution of groundwater chemical constituents is a major global problem. Despite this, resilient techniques of tracing the sources of groundwater salinization in semi-arid basin aquifers are still evolving due to the aquifer complexities. This study proves the effectiveness of the use of different ionic ratios, multivariate statistical, and geochemical modeling approaches to understand groundwater evolution and trace salinization in the semi-arid Pru Basin of Ghana. The basin is homogeneously composed of argillaceous sediments of the Oti/Pendjari Group of the Voltaian Supergroup. A total of 81 samples from hand-dug wells and boreholes within the Pru Formation of the Oti/Pendjari Group in the basin were collected for this study. Quantitative analysis of the data shows that the abundance of major ions follows the order: Na+ -> Ca2+ -> Mg2+ -> K+ and Cl- -> HCO3 -> SO42-. The groundwater evolved from Na-HCO3, Na-HCO3-Cl, Na-Ca-HCO3 to Na-Mg-HCO3 water types in a decreasing order of abundance. Calculated meteoric genesis index (r2) indicates the dominance of deep meteoric water percolation effects on groundwater chemistry. Groundwater chemistry is principally controlled by water-rock interaction, ion exchange reactions, weathering (carbonate and silicate), salinization, and anthropogenic activities. Different ionic ratio plots and spatial distribution maps reveal the prevalence of salinization in the aquifer system, especially around the southwestern part of the basin. Revelle index assessment of the groundwater salinization level indicates that about 19.8% of the groundwater samples with RI values >0.5 is influenced by salinization. The groundwater salinization results from saline water intrusion from adjacent aquifers, mixing effects, ion exchange reactions, water-rock interaction, and anthropogenic activities. The geochemical modeling involving thermodynamic calculation of mineral saturation indices in PHREEQC indicates that groundwater is largely saturated with respect to majority of the carbonate and silicate mineral phases.

The aim of this research was to establish the nexus between liquidity and the viability of quoted non-financial establishments in Ghana. Panel data deduced from the published annual reports of 15 entities for the period 2008 to 2017 was employed for the study. Preliminarily, cross-sectional reliance, unit root, serial correlation, heteroscedasticity, co-integration, and causality tests were respectively performed. Our findings established that there exists no cross-sectional reliance, and input variables are stationary and co-integrated with no presence of heteroscedasticity and serial correlation. Estimates from the random effects generalized least squares (GLS) regression showed that liquidity has significant adverse effect on the firms’ Return on Equity (ROE) but had insignificantly positive effect on ROE when surrogated by the cash flow ratio. Finally, test based on causalities uncovered that, with the exception of Current Ratio and ROE that are flanked by bidirectional liaison, no other causal affiliation was evidenced amid other variables. Policy recommendations are further discussed.

The reactions of thioformaldehyde (H2CS) with OH radicals and assisted by a single water molecule have been investigated using high level ab initio quantum chemistry calculations. The H2CS + ˙OH reaction can in principle proceed through: (1) abstraction, and (2) addition pathways. The barrier height for the addition reaction in the absence of a catalyst was found to be -0.8 kcal mol-1, relative to the separated reactants, which has a ∼1.0 kcal mol-1 lower barrier than the abstraction channel. The H2CS + ˙OH reaction assisted by a single water molecule reduces the barrier heights significantly for both the addition and abstraction channels, to -5.5 and -6.7 kcal mol-1 respectively, compared to the un-catalyzed H2CS + ˙OH reaction. These values suggest that water lowers the barriers by ∼6.0 kcal mol-1 for both reaction paths. The rate constants for the H2CSH2O + ˙OH and OHH2O + H2CS bimolecular reaction channels were calculated using Canonical Variational Transition state theory (CVT) in conjunction with the Small Curvature Tunneling (SCT) method over the atmospherically relevant temperatures between 200 and 400 K. Rate constants for the H2CS + ˙OH reaction paths for comparison with the H2CS + ˙OH + H2O reaction in the same temperature range were also computed. The results suggest that the rate of the H2CS + ˙OH + H2O reaction is slower than that of the H2CS + ˙OH reaction by ∼1-4 orders of magnitude in the temperatures between 200 and 400 K. For example, at 300 K, the rates of the H2CS + ˙OH + H2O and H2CS + ˙OH reactions were found to be 2.2 × 10-8 s-1 and 6.4 × 10-6 s-1, respectively, calculated using [OH] = 1.0 × 106 molecules cm-3, and [H2O] = 8.2 × 1017 molecules cm-3 (300 K, RH 100%) atmospheric conditions. Electronic structure calculations on the H2C(OH)S˙ product in the presence of 3O2 were also performed. The results show that H2CS is removed from the atmosphere primarily by reacting with ˙OH and O2 to form thioformic acid, HO2, formaldehyde, and SO2 as the main end products.

With the rapid development of economies, the problem of water resources availability particularly in sub-Sahara Africa (SSA) has increased significantly. Specifically, in recent times, addressing the challenge of access to water resources has become a global issue of which countries in SSA are not exceptional since the adequate supply of potable water is as relevant as economic development. Consequently, this current paper seeks to estimate the determinants of water resources availability in sub-Sahara Africa. For this purpose, a panel-based regression model, which represents the availability of water resources, is specified based on the period 2000 to 2016 to examine a panel of 41 SSA countries sub-sectioned into low, lower-middle, and upper-middle-income nations. Considering the existence of residual cross-sectional reliance, outcomes based on the CIP and CADF unit root tests showed that the variables were not integrated at the same order. This thus leads to the employment of the PMG/ARDL estimation approach which unveiled that (i) agriculture production has a significant negative influence on H2O in the lower-middle and low-income panel of SSA countries whereas in the upper-middle-income panel, an insignificant impact is witnessed; (ii) CO2 emissions affect H2O palpably in the upper-middle-income SSA panel while for lower-middle and low-income panels, an adverse effect is identified; (iii) economic growth adversely influenced H2O resources in the lower-middle-income panel whereas in the case of the low-income panel, a significant positive liaison is evidenced; (iv) excluding low-income panel, industrial development concerning H2O has a significant negative influence in upper-middle and lower-middle-income panels; (v) urbanization homogeneously showed a positive relationship with H2O resources across all panels. The results are reconfirmed by the CCEPMG/CS-ARDL and MG employed as robust methods. Causality checks by Dumitrescu-Hurlin test finally revealed a mixture of results regarding the causal paths amid variables among the country panels. Policy recommendations have therefore been proposed based on the study findings.

This study was aimed at identifying and quantifying mixing proportions in surface waters downstream of historical Cu-W-F skarn mine tailings at Yxsjöberg, Sweden, using 18O, 2H, and 87Sr/86Sr isotopes. In addition, a simple mathematical model was developed to evaluate the consistency of the mixing calculations. Hydrochemical and isotopic data from 2 groundwater wells, 6 surface water and 2 rainwater sampling sites, spanning 6 sampling campaigns between May and October were used. Three mixed surface waters downstream of the tailings were identified, namely: C7, C11 and C14. C7 was directly influenced by groundwater from the tailings whereas C11 was also subsequently influenced by C7. C14 on the other hand, had contributions from C11. Sequential mixing calculations indicated that the contribution of the groundwater to C7 ranges from 1 to 17%. The subsequent contribution of C7 to C11 varied from 49 to 91% whereas C14 had contributions of C11 ranging between 16 and 56%. A strong agreement between the model data (MD) and measured raw data (RD) for C11 and C14 indicated the accuracy of the mixing calculations. Variations between the MD and RD at C7, however, was mainly due to sorption and reductive processes underneath the tailings, which tend to attenuate the amount of dissolved ions reaching the surface waters, resulting in a low ionic contribution of the tailings groundwater to the surface water. The low ionic contribution of the groundwater to C7 suggested that although the tailings impoundment is of environmental concern, its impact on the downstream surface waters is small. The results of this study suggest that mixing calculations in surface waters involving a closed system such as groundwater (as an end-member) must be treated with caution. It is recommended that the interpretation of such mixing results must be coupled with detailed knowledge of the potential hydrogeochemical processes along its flow paths. Validerad;2020;Nivå 2;2020-04-29 (alebob)

The Kwahu-Bombouaka Group of the Voltaian Basin, which defines the northern fringe of the basin, constitutes a significant part of the North East Region of Ghana. Most of the inhabitants in the region depend on groundwater for domestic and irrigation purposes. Therefore, a geochemical characterization and assessment of groundwater quality in the area was carried out using hydrochemical, GIS-based ordinary kriging interpolation and multivariate statistical methods on fifty-five (55) borehole water samples. The aim of this study was to determine the concentrations and spatial distribution of various ions, groundwater quality issues and the geochemical processes contributing to groundwater chemistry. The area is largely underlain by sandy shales and mudstones of the Poubogou Formation and feldspathic, quartzitic sandstones with conglomeratic lenses of the Panabako Formation. The abundance of major cations in the groundwater is in the order: Na+ > Ca2+ > K+ > Mg2+ whereas that of the major anions vary in the order: HCO3− > SO42− > Cl−. Na–HCO3 water type is common in the area, which may be due to dissolution from silicate minerals (albite and microcline) in the basement rocks. The results indicate that fluoride (0.01–8.40 mg/L, mean of 0.58 mg/L) and boron (0.01–4.81 mg/L, mean of 0.28 mg/L) contamination is a threat to groundwater quality with respect to their guideline values provided by the World Health Organization. The groundwater chemistry is primarily controlled by ion exchange reactions, weathering of silicate minerals residing in the Panabako Formation and anthropogenic activities from agriculture. Groundwater in the area is largely suitable for drinking purposes although some few boreholes in the northwestern and southeastern parts have high fluoride and boron concentrations. The sodium percentage (11–99%, mean of 70%), magnesium ratios (2.05–57, mean of 29) and sodium adsorption ratio (0.15–38, mean of 4.72) are quite high in some of the communities in the southeastern part of the area. This suggests that water in this part of the area is not entirely suitable for irrigation purposes.

Several plants of agricultural and medicinal importance utilize defense chemistry that involves deployment of highly labile, reactive, and lachrymatory organosulfur molecules. However, this chemistry is difficult to investigate because the compounds are often short-lived and prone to degradation under the conditions required for analysis by common analytical techniques. This issue has complicated efforts to study the defense chemistry of plants that exploit the use of sulfur in their defense arsenals. This work illustrates how direct analysis in real time-high resolution mass spectrometry (DART-HRMS) can be used to track organosulfur defense compound chemistry under mild conditions. Petiveria alliacea was used as a model plant that exploits the enzyme alliinase to generate induced organosulfur compounds in response to herbivory. Tracking of the organosulfur compounds it produces and quantifying them by DART-HRMS using isotopically labeled analogues revealed a feedback inhibition loop through which the activities of the alliinase are stymied shortly after their activation. The results show that the downstream thiosulfinate products petivericin (100 μM) and pyruvate (8.4 mM) inhibit alliinase activity by 60% and 29%, respectively, after 1 h, and a mixture of the two inhibited alliinase activity by 65%. By 2 h, alliinase activity in the presence of these alliinase-derived products had ceased completely. Because thiosulfinate, pyruvate, and lachrymatory sulfine compounds are produced via the same alliinase-derived sulfenic acid intermediate, the inhibition of alliinase activity by increasing concentrations of downstream products shows how production of these defense compounds is modulated in real time in response to a tissue breach. These findings provide a framework within which heretofore unexplained phenomena observed in the defense chemistry of P. alliacea, onion, garlic, and other plants can be explained, as well as an approach by which to track labile compounds and enzymatic activity by DART-HRMS.

The stability analyses of slope excavations in rock mass require reliable geomechanical input parameters such as rock mass strength, friction angle and cohesion of sliding surface. These parameters are naturally uncertain and their exact values cannot be known, therefore, their variability must be properly accounted for in the stability analyses. Deterministic approaches such as the limit equilibrium methods, numerical methods and kinematic analysis methods do not account for the variability in any of the input parameter. This paper therefore provides a review of uncertainty and uncertainty analysis methods, problems and developments in geotechnical modelling of rock slope stability. The review is motivated by the availability of qualitative and number of methods for uncertainty analysis. The paper examines the various definitions and description of uncertainty and the different vocabularies that are used, and also summarises and categorises the different sources of uncertainty as well as integrating uncertainty for rock slope assessment problems. The paper discussed a simple survey of probability-based reliability methods that have been used for rock slope stability analysis in the past 3 decades.

Many plants have the ability to take up gold from soils and accumulate them in their tissues. Their concentrations and distributions reflect the nearby gold deposits masked by complex regolith. The 50 vegetation samples collected at Pelangio Tepa concession recorded low and subtle gold (Au) concentrations of 0.2 to 10.4 ppb at Pokukrom target, 0.3 to 28.3 ppb at Nfante East target and 0.1 to 1.7 ppb at Subriso target. Each target area had different concentration populations enough to distinguish the anomalous areas from the background contrary to Au-geochemical expressions derived from the gold in soils. So many uncertainties were placed on the soil-Au-geochemistry because the defined anomalies were not strong and generally appear patchy, weak and subtle that led to the assumption of no associated bedrock mineralisation. The gold in plant samples confirmed the Pokukrom anomaly that has been drilled and known to relate to underlying mineralisation. Much better and robust anomaly was defined by the biogeochemical Au data in plants sampled and analysed for Au at Nfante East target and isolated high patchy anomalies were identified at Subriso area. The case study at Pelangio Mamfo project reveals and recommends the significant application of biogeochemistry in mineral exploration particularly in the field of gold prospecting at the regional exploration stage and endorses it as being practically feasible in regolith-dominated terrains where regolith-landform modifications may impact on the true geochemistry in anomaly delineation. Keywords: Biogeochemistry, Regolith-Dominated-Terrain, Plant, Gold, Pelangio

Species determination of the various life stages of flies (Order: Diptera) is challenging, particularly for the immature forms, because analogous life stages of different species are difficult to differentiate based on morphological features alone. It is demonstrated here that direct analysis in real time-high-resolution mass spectrometry (DART-HRMS) combined with supervised Kohonen Self-Organizing Maps (SOM) enables accomplishment of species-level identification of larva, pupa, and adult life stages of carrion flies. DART-HRMS data for each life stage were acquired from analysis of ethanol suspensions representing Calliphoridae, Phoridae, and Sarcophagidae families, without additional sample preparation. After preprocessing, the data were subjected to a combination of minimum Redundancy Maximal Relevance (mRMR) and Sparse Discriminant Analysis (SDA) methods to select the most significant variables for creating accurate SOM models. The resulting data were divided into training and validation sets and then analyzed by the SOM method to define the proper discrimination models. The 5-fold venetian blind cross-validation misclassification error was below 7% for all life stages, and the validation samples were correctly identified in all cases. The multiclass SOM model also revealed which chemical components were the most significant markers for each species, with several of these being amino acids. The results show that processing of DART-HRMS data using artificial neural networks (ANNs) based on the Kohonen SOM approach enables rapid discrimination and identification of fly species even for the immature life stages. The ANNs can be continuously expanded to include a larger number of species and can be used to screen DART-HRMS data from unknowns to rapidly determine species identity.

Purpose The much-trumpeted Green Climate Fund and several other official financial mechanisms for financing adaptation to climate change under the UN Framework Convention on Climate Change have fallen short in meeting adaptation needs. Many poorer people are still grappling with the scourge of climate change impacts. Consequently, there has been a dominant research focus on climate change financing emanating from official development assistance (ODA), Adaptation Fund, public expenditure and private sector support. However, there has been little attempt to examine how migrants’ remittances can close adaptation financing gaps at the local level, ostensibly creating a large research gap. This paper aims to argue that migrants’ remittances provide a unique complementary opportunity for financing adaptation and have a wider impact on those who are extremely vulnerable to climate change. Design/methodology/approach The paper is aligned to the qualitative research approach. Both secondary and primary data acquired through interviews and focus group discussions were used for the study. Multiple sampling methods were also used to select the respondents. Findings The findings show that remittances are used to finance both incremental costs of households’ infrastructure and consumption needs, as well as additional investment needs to be occasioned by ongoing or expected changes in climate. Originality/value In the wake of dwindling government/public revenue, ODA and poor commitment of Annex II countries to fulfil their financial obligations, the study makes the following recommendations: First, the financial infrastructure underpinning money transfers in both sending and recipient countries should be improved to make transfers attractive. Second, significant steps should be taken to reduce the fees on remittance services, especially for the small transfers typically made by poor migrants. Finally, adequate climatic information should be made available to local people to ensure that remittances are applied to the right adaptation option to avoid maladaptation.

Through an interpretive research paradigm, we investigated the extent to which six local governments across three administrative regions of Ghana have complied with mandated climate change financin...

Substitution of the thiol proton in cysteine with m-carborane furnished 2-amino-3-(1,7-dicarba-closo-dodecacarboranyl-1-thio)propanoic acid (3), a boron cluster amino acid that exhibits self-assembly to form micron-sized constructs. Field emission scanning electron microscopy revealed that ethanol solutions of 3 form floret-shaped constructs, while fibrillar architectures are formed in water. Furthermore, slow evaporation of methanol solutions of 3 produced crystals whose structure was revealed by X-ray crystallography. The crystal structure shows that the hydrogen bonding interactions between pairs of 3 result in the formation of bilayers of 174 Å in length. The orientation of the clusters is not random in the crystal structure, such that the side-by-side aligned polyhedra are offset by 158 degrees. The material was characterized by FT-IR, NMR, high resolution mass spectrometry and dynamic light scattering. Circular dichroism studies indicated that self-assembly occurs at concentrations as low as 0.01 μM. This represents the first demonstration of self-assembly of a carborane-based molecule in the absence of metals. The amino acid motif provides opportunities for the controlled synthesis of extended multimeric units with tunable properties and the potential for applications in biology, medicine and materials chemistry.

The radius dependence of the electrical conductivity of metallic and semiconducting zigzag carbon nanotubes (CNTs) is theoretically studied. The investigation was done semiclassically by solving the Boltzmann transport equation to derive current density as a function of a homogenous axial dc field and radius of the tube. The analysis was numerically carried out by varying the radius of the materials at a constant temperature. Plots of the normalized current density versus dc field applied along the axis of both materials are presented. We observed that in the case of the metallic zigzag CNTs as the radius increases, the electrical conductivity decreases. On the other hand, in the semiconducting zigzag CNT there was an increase as radius increases. This research shows that thinner metallic zigzag CNTs and thicker semiconducting zigzag CNTs are better conductors of electricity. This investigation therefore offers way of obtaining higher electrical conductivity in both materials without doping. This study therefore shows applications in the development of current conducting nano-devices for scientific systems.