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The study examines the link between dietary diversity and BMI using data from Kenyan women aged 15–49. By exploring how dietary diversity affects BMI across various BMI categories, the study examines the demand for diet diversity and its impact on BMI. The results reveal a positive relationship between food diversity and BMI at all quantiles, suggesting that a more varied diet is associated with increased BMI levels among underweight, overweight, and obese individuals. This indicates that the correlation between dietary diversity and health outcomes in higher BMI categories may be ‘unfavourable’, with increased food diversity linked to a higher risk of ‘unfavourable’ BMI categories, i.e., overweight and obesity. This may be attributed to higher caloric intake and/or higher consumption of saturated fats and cholesterol from a more diverse diet, which can contribute to increased BMI. These findings highlight the need to consider moderation and balance in energy intake and the overall nutritional quality of diets when considering and evaluating diets and dietary diversity and in formulating and shaping food policies.

ObjectivesIn everyday language, climate change is an increase in the Earth’s average temperature. Climate change negatively affects life support systems, including air, food, water, shelter, and security, on which humans depend. This paper aims to holistically integrate maternal and child health into climate change.MethodsA narrative/literature review approach were adopted using papers sources from google scholar, research gate and web of science. About 10 papers was initially gathered and it was later scrutinized to 6.ResultsIt was discovered that, climate change negatively impacts food and water security, heat stress, extreme weather, and air pollution, with women and children most affected. The World Health Organization estimates 250,000 climate-related deaths annually by 2050, disproportionately affecting maternal and child health. Integrating climate and maternal health strategies could offer benefits, yet research on adapting to climate change’s effects on pregnancy outcomes is limited.ConclusionAddressing maternal and child health requires integrating health-focused strategies into environmental policies to reduce vulnerabilities to climate-related risks. A comprehensive approach can enhance resilience by improving healthcare access, education, and sustainable resource management, benefiting public health and environmental outcomes.

As climate change leads to increase flood risks, South Africa continues to rely on government driven ex post relief initiatives for flood management whilst commercial insurance providers are not yet incorporated into broader flood management strategies. The willingness to pay (WTP) for flood risk insurance is investigated among this most vulnerable demographic of low income households. Using discrete choice experiments (DCE) and mixed logit models, it uses primary data from respondents in Buffalo City metropolitan municipality to analyse preferences for insurance attributes, such as coverage levels, premiums and excess fees. The findings also show that there is a strong preference for lower premiums, better quality insurers, and easier application processes for adoption. The results of mixed logit show that attributes like the increased building coverage results in positive WTP and further confirms the need for insurance plans that are easily accessible and affordable. Taken together, the findings in this research highlight the value of trust, transparency, and the cost effectiveness of policy design in boosting both consumption of flood insurance and community resilience to floods among vulnerable populations.

Climate change threatens smallholder farmers' productivity, revenue generation, and increases household food insecurity. Thus, adaptation and coping strategies are paramount for smallholder farming households to mitigate these impacts of climate change. This study used a bibliometric analysis to examine smallholder farmers’ coping and adaptation strategies to climate change (SFCA-SCC) research trends from 2010 to 2022. A total of 1635 papers were analysed from Scopus and Web of Science (WoS) databases to characterize the field and observe research trends. The articles from these databases demonstrate an upward trend in publications (54–300) over the period under study, signifying the importance of research on adaptation and coping strategies of climate change. The research findings showed that majority of studies originated from institutions in industrialized countries, while very few did so from emerging economies. According to the findings, smallholder farmers have embraced a range of adaptation and coping mechanisms to mitigate the impacts of climate change, such as altering planting schedules, and diversifying crop varieties among others. It is imperative for African researchers and institutions to engage in more research aimed at developing strategies to mitigate the risks posed by climate change.

Positive Selection (PS) technique has been shown to reduce virus infection and increase yields, however there is insufficient empirical evidence on how this technology affects seed yam farm productivity. This study employed Propensity Score Matching (PSM) technique to evaluate the impact of PS on seed yam yields of 368 farmers randomly selected from Ghana and Nigeria.The findings showed that educational attainment, distance from the farm to the nearest market, cropping patterns, and other factors influenced farmers' adoption of PS. Furthermore, the adoption of PS technology resulted in a 16.98 % boost in farm productivity for PS seed yam farmers compared to their productivity without the technology. It is of the utmost importance that PS adoption be supported by developing tailored training materials for farmers to improve their use of the PS technology.

Substance abuse is a major public concern for the entire world. Using data from the National Income Dynamic Study wave four, this study examines the impact of substance (alcohol and tobacco) consumption on labour market outcomes in South Africa using the multinomial endogenous switching regression technique. This method controls for any potential selection bias and endogeneity problems. The results from the study reveal that individuals’ decisions to consume alcohol only, tobacco only, and a combination of both are driven by socioeconomic, health, and demographic factors. The estimated causal effect shows that substance use reduces individuals’ earnings in almost all cases and increases working hours. The findings suggest that efforts to control the use of alcohol and tobacco in South Africa should focus more on sensitization programmes that address the health, psychological, and economic implications of using these substances.

Sorghum (Sorghum bicolor [L.] Moench) production has considerable socio-economic values in sub-Saharan Africa for food security and to serve the increased industrial demands due to high population pressure and climate change. However, the production and productivity of the crop are yet to be expounded in Nigeria for economic gains. Therefore, the objective of this study was to present the current opportunities and constraints to sorghum production in Nigeria. A participatory rural appraisal (PRA) study was conducted in three selected sorghum growing zones in northern Nigeria involving 250 farmers. Socio-economic data were collected through surveys and focus group discussions. Sorghum was cultivated mainly by males (80%) who had grade 6-12 level of education (31.3%), with the productive age of 21-45 years (75.7%) and a household family size of below five members (52.3%). Low yielding landrace varieties such as Kaura (37.4%) and Fara-fara (29.3%) were the most widely cultivated types across the study zones due to their good grain quality. The major farmers' preferred traits from a sorghum variety were high yield, drought tolerance and Striga resistance. The study recommends integrated sorghum technology development incorporating the described preferences of the farmers for sustainable production and economic gains of the crop.

Fault diagnosis and condition monitoring of synchronous machines running under load is a key determinant of their lifespan and performance. Faults such as broken rotor bars, bent shafts and bearing issues lead to eccentricity faults. These faults if not monitored may lead to repair, replacement and unforeseen loss of income. Researchers who attempted to investigate this kind of machine stopped at characterizing and deduced ways, types and effects of rotor eccentricity fault on the machine inductances using the winding function method. A modified closed-form analytical model of an eccentric synchronus reluctance motor (SynRM) is developed here taking into cognizance the machine dimensions and winding distribution for the cases of a healthy and unhealthy SynRM. This paper reports the study the SynRM under static rotor eccentricity using the developed analytical model and firming up the model with finite element method (FEM) solutions. These methods are beneficial as they investigated and presented the influence of the degrees of static eccentricity on the machine performance indicators such as speed, torque and the stator current and assess the extent to which the machine performance will deteriorate when running with and without load. The results show that static eccentricity significantly affects the machine’s performance as the degree of eccentricity increases.

As a result of climatically regulated water sources, smallholder farming households in South Africa are severely impacted by climate change. Using the Livelihood Vulnerability Index, we assessed the vulnerability of smallholder farming households to climate change in Thaba Nchu, Mangaung District of the Free State Province of South Africa. Primary data from 301 smallholder farming households were collected and augmented with secondary data on temperature and rainfall from 2010 to 2020. The study found that farming households in Central Thaba Nchu are more vulnerable than those in North and South Thaba Nchu in terms of adaptive capacity: social network, livelihoods strategies, and socio-demographic structure. The Central Thaba Nchu were likewise more vulnerable to water resources than the Northern and Southern Thaba Nchu. However, Northern Thaba Nchu is more exposed and sensitive to health-related difficulties than Central and Southern Thaba Nchu. The study recommends that non-government and government institutions in the province should employ a pragmatic method to evaluate vulnerability using climate service information while prioritizing vulnerable households for adaptation support to improve adaptive capacity and resilience. The findings also imply that weather forecasters, in partnership with agricultural extension agents, must provide farmers with timely and adequate climate information reports to prepare them for climatic shocks. Moreover, it is important to deliver climate service information that is genuine, significant, and reliable.

This study examines consumers' willingness to pay a higher price premium for quail products using the price of chicken as a benchmark. A double-bounded dichotomous choice contingent valuation was used to elicit the data, and the factors influencing consumers’ willingness to pay (WTP) were identified using the ordered logit regression model. Results revealed that on the average consumers were willing to pay a higher price premium for quail products, with the mean WTP of GH¢ 27.46 ($5.66), representing 196.14% price premium and GH¢26.34 ($5.43) representing 196.03% price premium per crate of eggs and 1kg of quail meat, respectively. These findings are crucial for the development of the products as well as formulating marketing strategies for its promotion in the African food markets.

Agricultural environment in many developing economies has become increasingly unpredictable in recent decades as a result of climate change, increasing the risk of crop failure. Access to meaningful information is required to mitigate the negative effects of the changing environment. This study examined the impact of agricultural extension services on the adoption of soil and water conservation (SWC) practices using data obtained from farming households in Northern Ghana. A multivariate probit model was used to assess the simultaneous or/and substitution adoption of SWC practices, while endogenous switching probit (ESP) was used to estimate the impact of extension services on adoption of SWC practices to account for observed and unobserved heterogeneities. The results showed that most of the SWC practices were adopted jointly, and factors such as non-farm economic activites and farm size influence the adoption of SWC practices. Moreover, farmers who accessed agricultural extension services had a higher probability of adopting most of the SWC practices (crop rotation, contour ploughing and manure application), and those who did not benefit from extension services would have had an equally higher likelihood of adopting the SWC practices had they accessed the services. The findings of the study imply that enhancing agricultural extension services will reduce adoption gaps in SWC practices, and consequently reduce farmers’ exposure to climate-related agricultural production risks. With growing information and communication technologies, pluralistic extension service delivery that mixes governmental and private-sector-led approaches to extension operations to foster demand-driven extension delivery services are highly recommended.

Abstract Background Achieving food security is a global priority and a concern for most African countries, including Ghana. Food systems providing varied and healthy diets without compromising the natural resource base, such as integrated crop–livestock diversification, are important for development planning and policy. Using cross-sectional data obtained from 1284 smallholder households in northern Ghana, we used a double-censored Tobit model in a conditional mixed-process (CMP) framework to estimate the impact of crop diversification on household food security. Results The results showed that household-specific, socioeconomic, and institutional factors influence crop–livestock diversification and food security in northern Ghana. Moreover, we found that higher intensity of crop–livestock diversification translates into a greater probability of achieving food security. Conclusions Crop–livestock diversification is essential to Ghana’s pursuit of the zero-hunger global agenda as it enhances food security without adversely affecting biodiversity and ecosystem health. Therefore, it should be incorporated into Ghana’s ongoing agricultural programme dubbed, planting and rearing for food and jobs.

Many empirical studies have documented the role of farm management practices such as irrigation in reducing poverty and improving household well-being. Few studies, however, have looked at the impact of irrigation farming on poverty vulnerability and the welfare of rural farming household. This study examined the factors that influence farmers’ participation in irrigation farming, as well as how it affects farmers' food consumption expenditure per capita (proxy for welfare), poverty gap index, poverty severity and poverty vulnerability. The study's data was collected from farming households in the northern and coastal parts of the Eastern province of South Africa. The endogenous switching regression (ESR) model was employed in the study to account for selection bias that could be caused by both observed and unobserved household factors. The empirical result shows that gender, household size, educational attainment, crop diversification, and market outlet among others influenced farmers' decision to practice irrigation farming. Farmers engaging in irrigation farming boosted their food consumption per capita by 44%, while non-participants would have increased their consumption expenditure per capita by 23% if they had participated. Moreover, participating farmers reduced their poverty gap index by 20% and poverty severity by 22%, whereas non-participating farmers could have reduced their poverty gap index and poverty severity by 5% and 17%, respectively had they engaged in irrigation farming. Participation in irrigation farming also reduced poverty vulnerability by 25%, while non-participants may have reduced poverty vulnerability by 3%. The findings suggest that enhancing farmers' access to irrigation is crucial to meeting the Sustainable Development Goals (SDGs), which aim to eradicate poverty in all its manifestations everywhere.

Abstract Background The adoption of climate-smart agricultural (CSA) practices is expected to improve farmers’ adaptation to climate change and also increase yields while simultaneously curbing greenhouse gas (GHG) emissions. This paper explores the determinants of smallholder farmers’ participation in GHG-emitting activities. It also estimates the impact of CSA activities on reducing GHG emissions. Methods The findings are based on survey data obtained from 350 smallholder farmers in the East Gonja district of Northern Ghana. We adopted the generalized Poisson regression model in identifying factors influencing farmers’ participation in the GHG emission practices and inverse-probability-weighted regression adjustment (IPWRA) to estimate the impact of CSA adoption on GHG emissions. Results Most farming households engaged in at least one emission activity. The findings of the generalized Poisson model found that wealthier households, higher education, and households with access to extension services were less likely to participate in GHG emission activities. There was also evidence that CSA adoption significantly reduces GHG emissions. Conclusion Advocacy in CSA adoption could be a necessary condition for environmental protection through the reduction of GHG emissions.

Abstract Technical inefficiency persists in Ghana’s cocoa farms. Farm-level guidelines from empirical studies are essential to inform programmes dealing with this challenge and subsequently improves farmers’ welfare. This study evaluates the two-way effects of technical efficiency and welfare using Data Envelopment Analysis (DEA) and Conditional Mixed-process (CMP). The study reveals that, with no additional inputs, farmers have the potential of increasing their output by an average of 56% (overall technical efficiency) with mean pure technical and scale efficiencies estimated at 76% and 58%, respectively. Observed inefficiency in the Ghanaian cocoa farms is due to both inefficient utilization of inputs and farmers’ inability to operate at the most productive scale size. Furthermore, findings from the study indicated that improved technical efficiency and welfare of smallholder cocoa farmers are crucial for the sustainable growth of Ghana’s cocoa sector as farmers’ efficiency and welfare significantly complement each other. In other words, improved welfare enhances technical efficiency, and higher technical efficiency score translates into better welfare. Hence, farm-level policies such as inputs subsidy programmes, training farmers on the proper application of agrochemicals, among others to enhance farm efficiency should be strengthened since efficiency is tied to household welfare. Moreover, investment in education targeted at farmers to improve their managerial and technical capacities will enhance their ability to optimize the operational size of the cocoa production system, and subsequently improve their welfare.

The inefficiency of cyanide/HCN (CN) binding with heme proteins (under physiological regimes) is demonstrated with an assessment of thermodynamics, kinetics, and inhibition constants. The acute onset of toxicity and CN’s mg/Kg LD50 (μM lethal concentration) suggests that the classical hemeFe binding-based inhibition rationale is untenable to account for the toxicity of CN. In vitro mechanistic probing of CN-mediated inhibition of hemeFe reductionist systems was explored as a murburn model for mitochondrial oxidative phosphorylation (mOxPhos). The effect of CN in haloperoxidase catalyzed chlorine moiety transfer to small organics was considered as an analogous probe for phosphate group transfer in mOxPhos. Similarly, inclusion of CN in peroxidase-catalase mediated one-electron oxidation of small organics was used to explore electron transfer outcomes in mOxPhos, leading to water formation. The free energy correlations from a Hammett study and IC50/Hill slopes analyses and comparison with ligands (CO/H2S/N3-)$\left( {\text{CO}}/{{{{\text{H}}_{2}}\text{S}}/{\text{N}_{3}^{\text{-}}}\;}\; \right)$ provide insights into the involvement of diffusible radicals and proton-equilibriums, explaining analogous outcomes in mOxPhos chemistry. Further, we demonstrate that superoxide (diffusible reactive oxygen species, DROS) enables in vitro ATP synthesis from ADP+phosphate, and show that this reaction is inhibited by CN. Therefore, practically instantaneous CN ion-radical interactions with DROS in matrix catalytically disrupt mOxPhos, explaining the acute lethal effect of CN.

The expansion of Ghana’s cashew industry is expected to be a watershed moment in the country’s diversification of agricultural export commodity trade. In Ghana’s cashew farms, however, there is a significant difference between observed and potential farm yield. As a result, empirical study is required to serve as policy guidelines in order to improve farmer’s productive efficiency and, as a necessary consequence, contribute to the achievement of the Sustainable Development Goals (SDGs) of no poverty and zero hunger. The study explores farm-level productive efficiency and factors that can lead to variations in farmer’s technical efficiency in the Bono East region of Ghana. The single-stage double bootstrap Data Envelopment Analysis (DEA) was used to estimate technical efficiency and its determinants. The estimated results indicate that the average bias-corrected technical efficiency score (33%) was lower than the original average score (51%), suggesting that the original efficiency scores had been skewed upwards. Some of the primary factors that have been reported as having a significant effect on technical efficiency include the gender of respondents, educational attainment, and membership of farmer groups. Results of the resource-use efficiency analysis suggest that cashew farmers in Ghana do not escape the criticisms of inefficient resource allocation. Farm-level policies should be skewed towards enhancing resource-use efficiency through effective capacity-building to improve farmer’s management and technical capabilities, improve farm productivity, and consequently contribute to Ghana's quest to meet the sustainable development goals.

Climate change significantly impacts global agricultural productivity. Therefore, a more dynamic farming system is needed to enable farmers to better adapt to climate change while contributing to efforts to produce enough food to feed the growing world population. In the context of climate change, this study analyzed the empirical scientific literature on the link between climate-smart agriculture and farm productivity. To evaluate the relevant articles, the authors used the search term “climate-smart agriculture amidst climate change to enhance agricultural production (CSA-CCAP)” to find studies published between 2009 and March 2022 using innovative bibliometric techniques. One hundred and sixteen published papers in BibTeX format were downloaded for further analysis. The most successful selected CSA approaches in Africa, such as in the Congo Basin forest, including sustainable land management practices, water-efficient maize hybrids, and others, aim to counteract climate change with signs of 200 percent output gains. The findings showed an annual growth rate of about 19%, demonstrating that research on CSA-CCAP expanded over time during the study period. Nonetheless, the research output on CSA-CCAP varied, with 2021 accounting for 30%, followed by 2020 with 16% as of March 2022. The study concluded that boosting agricultural productivity in the face of climate change may be accomplished through CSA to end hunger, eradicate poverty, and improve people’s well-being.

Although women are actively involved in a wide array of agricultural production activities, they have limited access to farm productive resources and their influence in decision-making is also restricted compared with men. These limitations have the potential to affect women performance in agriculture. This study assesses gender-based farm performance (proxy by productivity) differences and identified sources of performance differentials amongst rice farmers in rural Nigeria using the Blinder-Oaxaca gender decomposition framework. The results revealed a disparity between men and women with a gender performance gap of about 11% in favour of men, of which 77.66% of the gap remained unexplained after accounting for gender differences in household characteristics, access to supply-driven factors, and farm productive resources. A more detailed analysis suggests that factors such as the use of improved rice varieties, membership of farmer-based organisations, extension services, and quantity of seeds sown could contribute to the gender performance gap. As a result, the study concludes that focusing on these productivity gaps and the factors that contribute to them is critical for developing policy interventions aimed at empowering women.

Abstract Zai is a conventional soil rehabilitation management practice where organic matter is buried in a small pit to help restore fertility and conserve water in the soil. However, adoption of this environmentally-friendly technology is low. This study makes two key contributions. First, it identifies the determinants of adoption and intensity of adoption of Zai technology for soil fertility management. Second, it performs diagnostic tests to show that Cragg’s double-hurdle as compared to the Heckman and the standard Tobit regression models is the best econometric approach to identify factors influencing farmers’ decision to adopt and the extent of adoption of the Zai in the Upper East region, Ghana. Results from the Cragg’s double-hurdle model revealed that different set of variables affect the probability and the intensity of adoption of Zai technology. The paper concludes that farm households should be encouraged to engage in non-farm economic activities to complement their farm income and enhance the purchase of productive farm inputs. Moreover, farm-level policies oriented towards increasing access to agricultural extension services, credit facilities, and the facilitation of farmer groups are essential to improving the adoption of farm innovations such as the Zai technology.

Non-farm employment in agrarian communities in developing countries has received a lot of attention. However, its role in implementing climate change adaptation strategies is rarely discussed. This study employs a cross-sectional data to examine whether rural households in Southwest Nigeria are increasing the extent of climate change adaptation practices through their participation in non-farm employment. To account for selectivity bias, the study used endogenous treatment effect for count data model (precisely Poisson) augmented with the inverse probability-weighted-regression-adjustment (IPWRA) estimator. Both estimators found that rural non-farm jobs increase smallholder farmers' adaptive capacities and that participants would have used less adaptation techniques if they had not participated in non-farm work. Efforts to boost rural development must provide more employment opportunities for farmers, particularly during the off-cropping time. This will help farmers improve their ability to adopt more climate change adaptation strategies and, consequently increase farm productivity.

Poverty persists in many developing countries, including Nigeria, owing to inadequate infrastructure, unemployment, or poor working conditions, among other factors. Youth poverty and vulnerability to poverty have been identified to prevalent among the young population. Using an endogenous switching probit regression approach, in this study, we evaluated the impacts of youth participation in agribusiness programs (YIAPs) on poverty and vulnerability to poverty in Nigeria. Our findings revealed that some demographic and institutional factors significantly influence poverty and vulnerability to poverty among youth. The impact estimates indicate that participation in an agribusiness program has a significant positive effect on poverty reduction among youth. Moreover, there would have been about a 28% reduction in exposure to future poverty for non-participants had they participated in a YIAP. Our results suggest that intervention programs, such as YIAPs, that focus on skill acquisition and youth empowerment should be strengthened and scaled-up in order to improve youth welfare and subsequently reduce/eradicate poverty and vulnerability to poverty among youth.

Sustainable Agricultural Practices (SAPs) have been promoted over the years as a means of ensuring sustainable development in the agricultural sector. However, adoption has generally been low across countries. This paper explores the linkages among SAPs and adoption decisions of SAPs among smallholder maize farm households in Ghana. The study used a household-level data on 394 farmers collected by the second round of the intensification of food crops agriculture in sub-Saharan Africa (AFRINT II) in Ghana. We employed a multivariate regression model to investigate the complementarity and the substitutability among the selected elements of SAPs as well as the simultaneous determinants of the SAPs components. We found out that some elements of the SAPs are complementary, while others are substitutes. The results also suggest that access to input credit, membership of farmer-based organizations, extension contact, and formal education, as well as intercropping, lead to the adoption of SAPs. The study recommends that SAP programmes that support the application of one technology (e.g., inorganic fertilizer) must provide simultaneous support for intercropping with nitrogen-fixing plants. Also, investment in public education is crucial in boosting farmers’ knowledge of agricultural practices. Lastly, the positive and significant policy variables such as FBO suggest that focusing on strengthening community social network institutions is one other way of improving adoption decisions of SAPs.

This study explored the potential impact of rural non-farm income diversification on households' welfare and adoption of Zai-technology (a proxy for agricultural technology adoption) using primary data collected from agricultural households in the Upper East region of Ghana. We used Propensity Score Matching (PSM) and Inverse-Probability-weighted Regression Adjustment (IPWRA) techniques to estimate welfare and Zai-technology impacts of non-farm income diversification. After controlling for differences in covariates, the results show that non-farm income diversification increases the likelihood of Zai-technology adoption and contributes to significant household welfare gains. We therefore suggest that the activities of agricultural extension services and farmer-based organizations (FBOs) be enhanced as they facilitate the diversification of non-farm incomes, thereby increasing investment in productivity-enhancing technologies (Zai) and household welfare.

For most developing countries like Ghana, the adoption of productive agricultural technologies in the quest to achieve food security and improve farmers' welfare cannot be overemphasized. Hence, interventions that have the potential to enhance the impact of the adoption of these technologies are critical for development planning and policy. This study investigates whether or not village saving groups enhance the welfare impact of agricultural technology adoption using farm-level data collected from the Garu and Tempane districts in the Upper East Region, Ghana. We applied an instrumental variable regression model that incorporates an endogenous interaction term to estimate the interceding role of village saving groups on the welfare impact of agricultural technology adoption. The empirical results reveal that participation in village savings groups further enhances the welfare impact of agricultural technology adoption (proxy by Zai technology). The factors that influence farmer's participation in village saving groups include the number of extension contacts, membership of farmer-based organizations (FBOs) and access to farm credit. Other factors such as the age of the farmer, household size and years of education were also found to influence farmers' decisions to adopt Zai technology. The study recommends the promotion of village saving groups as they build rural farmers' capacity to save for farm investment, which further enhances their adoption of agrarian technology in the quest to improve farmers' welfare. Moreover, policy instruments like the revitalization of extension services, the formation of FBOs, and access to farm credits should be strengthened in this pursuit.

This study considers the presence of a gender gap in technical efficiency in Ghana's cocoa production sector. The two-stage double bootstrap data envelopment analysis (DEA) procedure was applied to estimate the bias-corrected technical efficiency scores for male and female cocoa farm managers. The results indicate that there is a potential for male and female cocoa farm managers to increase output without altering the quantities of inputs employed. Applying the extended version of the Blinder-Oaxaca (B-O) decomposition approach, the findings suggest that female plot managers are, on average, less technically efficient compared to their male counterparts. This gap could be linked to differences in their resource endowments. Nevertheless, there are still significant unobservable factors that contribute to the gender efficiency gap. A comprehensive decomposition examination indicates that differences in educational attainment, engagement in non-farm activities, and farm size may contribute to the unexplained technical efficiency gap. The study recommends that female-sensitive programmes that seek to encourage the participation of non-farm activities and provide access to education and land utilization are essential in reducing the gender gap in technical efficiency.

Abstract Background In agricultural-dependent economies, extension programmes have been the main conduit for disseminating information on farm technologies, support rural adult learning and assist farmers in developing their farm technical and managerial skills. It is expected that extension programmes will help increase farm productivity, farm revenue, reduce poverty and minimize food insecurity. In this study, we estimate the effects of extension services on farm productivity and income with particular reference to agricultural extension services delivered by Association of Church-based Development NGOs (ACDEP). Methods The study used cross-sectional data collected from 200 farm households from two districts in the Northern region of Ghana. The robustness of the estimates was tested by the use of regression on covariates, regression on propensity scores and Heckman treatment effect model. Results The study found positive economic gains from participating in the ACDEP agricultural extension programmes. Apart from the primary variable of interest (ACDEP agricultural extension programme), socio-economic, institutional and farm-specific variables were estimated to significantly affect farmers’ farm income depending on the estimation technique used. Conclusions The study has reaffirmed the critical role of extension programmes in enhancing farm productivity and household income. It is, therefore, recommended that agricultural extension service delivery should be boosted through timely recruitment, periodic training of agents and provision of adequate logistics.

This study explores the determinants of income diversification using a sample of 200 farm-level data collected from households in the Garu-Tampane district, Ghana. The Simpson Index of Diversification was used to determine the extent of income diversification while Fractional Response Model, particularly Generalized Linear Model (GLM) was employed to identify the determinants of income diversification. Results from the Simpson Index of Diversification showed that the average income diversification index was 0.65 with the minimum and maximum of 0.13 and 0.83, respectively. No farm household was found to depend solely on a single source of income for its survival. The results from the Generalized Linear Model revealed that extension services, attendance to demonstration fields, membership of Farmer-based Organizations (FBOs), farmer accessibility to credit, the number of days spent on on-farm activities per month and the number of years in maize farming significantly influence income diversification. The study, therefore, concludes that farm-level policies geared towards alternative sources of income for the rural farm household should focus on improving extension services, the formation of farmer-based organizations, use of demonstration fields as well as ensuring farmers’ accessibility to credit.

Abstract Background Despite the widespread use of dexamethasone in veterinary and human medicine, it is reported to cause some severe pregnancy related side effects like abortion in some animals. The mechanism of the response is not clear but seems to be related to interspecies and/or breed difference in response which may involve alterations in the concentrations of some reproductive hormones. Methods Twenty Sahel goats comprising 18 does and 2 bucks were used for this study. Pregnancies were achieved by natural mating after synchronization. Repeated dexamethasone injections were given at 0.25 mg/kg body weight. Blood samples were collected biweekly for hormonal assay. Uterine biopsies were harvested at days 28 and day 78 of gestation through caesarean section for immunohistochemical analysis using 3 pregnant does randomly selected from each group at each instant. Data were expressed as Means ± Standard Deviations and analyzed using statistical soft ware package, GraphPad Instant, version 3.0 (2003) and progesterone receptor (PR) were scored semi-quantitatively. Results Dexamethasone treatments had no significant (p > 0.05) effect on progesterone and estrogen concentrations in pregnant Sahel goats but up regulated PR from 2+ to 3+ in second trimester. Conclusion As dexamethasone adverse effect on placenta is an established fact, the lack of effect on progesterone level in this study may be due to the fact that unlike other species whose progesterone production during pregnancy is placenta – dependent, in goats is corpus luteum - dependent. Consequently dexamethasone adverse effect on placenta reported in literatures did not influence progesterone levels during pregnancy in Sahel goat. The up regulation of progesterone receptor (PR) in Sahel goat gravid uterus is a beneficial effects and that dexamethasone can safely be used in corpus luteum – dependent progesterone secreting pregnant animal species like Sahel goat and camel. Therefore source of progesterone secretions during pregnancy should be considered in clinical application of dexamethasone in pregnancy.

The study examined how farmers’ technological choice affects technical efficiency (TE) in small-scale maize production in northern Ghana. A random sample of 340 respondents took part in the study. A binary probit modeling was applied to analyse adoption decision, while double bootstrap data envelopment analysis was relied upon to evaluate TE Truncated regression was used to assess the sources of inefficiency. The results indicated a bias-corrected TE of 57% under variable returns to scale assumption and 52% when constant returns to scale was assumed. Accounting for potential endogeneity of the adoption variable, the findings indicated that technical efficiency increased with technology adoption. Technical efficiency improved with herd size but decreased with educational attainment, number of household members, access to extension, frequency of weeding, and size of cultivated land. The study, therefore, recommends that making improved seeds available and affordable to small-scale producers and training farmers on effective weed management could be potential measures to enhance the farm-level technical efficiency.

The enhancement of agrarian productivity through the use of improved technologies such as fertilizer application is a critical avenue for increasing farm income, minimizing poverty, and tackling soil nutrient mining. This study has examined fertilizer adoption decisions using data collected from 226 smallholder cocoa farm households in the Western region of Ghana. The Heckman's two-stage model was employed to estimate the probability and the extent of fertilizer application in the Ghanaian cocoa farms. The result of the study indicated that the likelihood of fertilizer adoption was influenced by factors such as farmers’ engagement in off-farm economic activities, extension contacts, farm size, hired and family labour, and the value of productive farm assets. On the other hand, factors including household size, marital status, number of years working as a cocoa farmer (experience), support received from Non-Governmental Organizations (NGOs), farm size, and family labour significantly influence the extent of fertilizer adoption. Therefore, improving extension services to farmers and encouraging the ownership of farm assets could be useful for fertilizer adoption.

The study aimed at investigating the effects of off-farm participation on technical efficiency of maize production in the Tolon district of the Northern Region, Ghana. The Logit regression model was used to analyze the determinants of off-farm participation while the stochastic frontier production function was used to model the determinants of maize output and technical efficiency. The empirical results from the logistic regression model indicate that age of farmer, educational attainment, farming experience, farm size, and previous farm income are significant drivers of farmers’ participation in off-farm activities. Farmers’ average technical efficiency level was 90.7% suggesting a 9.3% potential loss to inefficiency. Moreover, participation in off-farm activities had a negative influence on farmers’ technical efficiency level. The study, therefore, recommends that farm-level policy should be directed towards making the agricultural sector attractive by promoting investment and agricultural employment opportunities in the rural areas so as to ensure full commitment to farming activities. JEL code: Q22

This study aims to identify the determinants of adoption of improved maize variety (IMV) among farmers in the northern region of Ghana and subsequently assess the factors influencing the intensity of IMV adoption. The study used two econometric techniques to address its objectives. Firstly, a multinomial logit was employed to identify factors affecting the adoption of IMV. Secondly, Tobit regression was used to analyze the determinants of the intensity of IMV adoption. A fractional regression model through the procedure proposed by Papke and Wooldridge was also used to test the robustness of the results obtained from the Tobit model. Results from the study revealed that variables such as the age of the household head, household size, level of experience, farm workshop attendance, the number of years in formal education, access to agricultural credit, membership of a farmer-based organization, availability of labor and extension contacts influence the adoption of IMV. Moreover, variables such as years in formal education, household size, distance to farm plots, attendance of demonstration fields, membership of a farmer-based organization, farm size, and previous income are significant determinants of the intensity of IMV adoption. The study has implications for achieving food security and poverty reduction through agricultural productivity growth.

This study assessed factors that affect awareness of health implications of agrochemical use and its effects on maize production in Ejura-Sekyedumase Municipality of Ashanti Region, Ghana. One hundred and fifty-four (154) maize farmers were randomly sampled from the municipality. The study used awareness indicators to estimate an index representing farmers’ awareness levels of health implications of agrochemical use. An ordered logit compliment with multivariate linear regression model was used to identify the drivers of farmers’ awareness level of health implications of agrochemical use. Also, a multivariate linear regression model was used to analyze the effects of health implications of agrochemical use on maize output. On average, the respondents have the moderate awareness level of health implications of agrochemical use (0.578). The awareness level was significantly explained by education, the number of children in school, ownership of TV/radio, experience in agrochemicals use, and farm size. The multivariate linear regression results showed that awareness levels of health implications of agrochemical use increase maize output. It is therefore recommended that interventions aimed at increasing farmers’ awareness levels of health implications of agrochemicals use should focus on educating farmers through interactive radio discussion and training sessions on the field and incorporate safety use of agrochemical in our educational curriculum.

This study evaluated the profit efficiency of artisanal fishing in the Pru District of Ghana by explicitly computing profit efficiency level, identifying the sources of profit inefficiency, and examining the constraints of artisanal fisheries. Cross-sectional data was obtained from 120 small-scale fishing households using semistructured questionnaire. The stochastic profit frontier model was used to compute profit efficiency level and identify the determinants of profit inefficiency while Garrett ranking technique was used to rank the constraints. The average profit efficiency level was 81.66% which implies that about 82% of the prospective maximum profit was gained due to production efficiency. That is, only 18% of the potential profit was lost due to the fishers’ inefficiency. Also, the age of the household head and household size increase the inefficiency level while experience in artisanal fishing tends to decrease the inefficiency level. From the Garrett ranking, access to credit facility to fully operate the small-scale fishing business was ranked as the most pressing issue followed by unstable prices while perishability was ranked last among the constraints. The study, therefore, recommends that group formation should be encouraged to enable easy access to loans and contract sales to boost profitability.

Considering the increasing demand in the rice industry, the study was undertaken to determine the factors influencing household preference for locally produced rice in the Upper East Region, Ghana. Primary data was obtained from a sample of 180 households with the aid of a structured questionnaire. Probit model and Kendall’s coefficient of concordance were used to analyze the data. Significant socioeconomic factors include income, age, sex, and marital status, whereas the quality factors such as the absence of foreign materials, packaging, and aroma were also significant determinants of preference for local rice. The top three traits consumers consider in their choice for local rice were good-looking grains, excellent packaging, and absence of foreign materials in the rice. There was an evidence of an increased preference for quality local rice. Hence, increased investment in the rice value chain, particularly the processing stage where quality standards remain the topmost priority, will help boost consumers’ confidence in the local rice market.

Climate Change has gained global attention due to its adverse impact on agriculture. Cocoa production in Ghana is also under threat following climate change. This study, therefore, examined farmers’ perception on climate variability and its effect on adaptation strategies in the Suaman district of Western Region, Ghana. It involved 240 cocoa farmers. The study estimated Heckman’s treatment effect model that corrected the presence of selectivity bias in the sample. From the result, 69.5% of the farmers perceived an increase in the average temperature while 22.5% perceived an increase in the average rainfall over the years. The factors that significantly influenced farmers’ perceptions were farm size, farm management training, household size and farmer-based organization (FBO) membership. The major adaptation strategies adopted by the farmers were pesticides application, planting improved varieties, mixed planting and changing planting dates. Farmers’ perception was found to have a positive impact on their adaptation. Other factors that significantly influenced adaptation were age of cocoa farm, household size and FBO membership. The study concluded that perceptions are essential in adapting to climate variability in the district. Training of farmers on cocoa production and other agricultural activities in relation to climate variability and its impact is highly recommended. Similarly, enhancing access to weather forecast information is important to enhance farmer’s perceptions and also effectively implement adaptation strategies such as changing planting dates.

The effects of vitamin C administration at varying time intervals on rectal temperature, respiratory rates, heart rates and sleeping time following xylazine anaesthesia was evaluated in rabbits. A total of 36 rabbits placed in six groups(A-F) with 6 animals per group each were used. Groups A and B were used as controls for vitamin C (120 mg/kg, oral) and xylazine (4 mg/kg, intramuscular) treatments, respectively, while groups C-F received vitamin C at four intervals prior to xylazine anaesthesia. The result of the study showed that vitamin Cpre-medication prior to xylazine anaesthesia induced depression in respiratory and heart rates and a slight increase in rectal temperature. It also significantly increased sleeping time in rabbits (p0.05) in temperature between groups either before or after xylazine administration. It was concluded that vitamin C alters the clinical parameters as well as the sleeping time in rabbits under xylazine anaesthesia.

Os plantios comerciais de Pinus foram estabelecidos no Brasil há mais de 30 anos, inicialmente nas regiões Sul e Sudeste. No entanto, com a introdução de espécies tropicais, tornou-se viável em todo o país. Considerando a importância da obtenção de parâmetros que permitam avaliar o crescimento e o potencial da produção de povoamentos de Pinus, o presente trabalho visa ajustar modelos tradicionais de relação hipsométrica para as espécies Pinus caribaea Morrelet var. hondurensis Barret & Golfari e Pinus tecunumanii Eguiluz & Perry, em povoamento homogêneo, no município de Vilhena, Estado de Rondônia. Foram ajustados dez modelos, e o critério de seleção obedeceu ao menor erro padrão de estimativa (Syx%), maior coeficiente de determinação ajustado (R²aj.), valor de F e coeficientes de regressão significativos e a análise gráfica dos resíduos. O modelo apresentou melhor ajuste, com R²aj. de 0,896 e Syx% de 3,941% para o P. caribaea var. hondurensis e R²aj. de 0,973 e Syx% de 6,319% para o P. tecunumanii.The commercial plantings of Pinus were established in Brazil for over 30 years, initially in the South and Southeast. However, with the introduction of tropical species, became feasible in the whole country. Considering the importance of obtaining parameters to assess growth and the potential production of Pinus, the present work aims to adjust traditional models of hypsometric relation to species Pinus caribaea Morrelet var. hondurensis Barret & Golfari and Pinus tecunumanii Eguiluz & Perry, in pure stand, in the municipality of Vilhena, Rondônia State. Ten models were adjusted and the selection criteria followed the lower standard error of estimate (Syx%), higher adjusted coefficient of determination (R²aj.), F value and regression coefficients significant and graphical analysis of the residues. The model showed the better fit, with R²aj. of 0,896 and Syx% of 3,941% for P. caribaea var. hondurensis and R²aj. of 0,973 and Syx% of 6,319% for P. tecunumanii.

The occurrence of beta-lactamase-producing Escherichia coli and Staphylococcus aureus in chickens was investigated. Specimens (n = 1 300) were collected from 400 chickens and were streaked on MacConkey agar plates. From each plate, presumptive growths of organisms were picked and streaked on eosin methylene blue and Baird-Parker agars, respectively. Typical colonies of E. coli and S. aureus with similar morphologies were identified by biochemical tests. Isolates were tested for beta-lactamase production and antimicrobial susceptibilities. Results indicated that 805 E. coli isolates from which 89 (11%) were beta-lactamase-positive and 660 S. aureus from which 58 (8.8%) were beta-lactamase-positive. Both isolates showed a high level of resistance to all twelve antibiotics screened. The increased prevalence of antibiotic resistance amongst bacterial organisms is undoubtedly correlated with the discovery and characterisation of multiple, transferrable resistance determinants, such as beta-lactamases, corresponding to their respective phenotypes. The implications of this for humans when handling and/or consuming chickens and chicken products contaminated with strains of such isolates, is a risk of transferrable multi-drug resistance and a failure of treatment. The results of our study indicated that beta-lactamase-producing E. coli and S. aureus are prevalent in chickens in Nigeria.

Breast cancer is one of the deadliest diseases in women with a mortality rate of 6.6%. Adverse effects of synthetic drugs have directed research toward safer alternatives such as natural compounds. This study focused on Psydrax dicoccos Gaertn, an evergreen tree abundantly distributed in Tamil Nadu (India) for its possible application against breast cancer cells. P. dicoccos leaf methanol extract, found within a wide range of phytochemicals, demonstrated cytotoxic effects against MCF7 breast cancer cells at IC 50 of 34 μg/mL. The extract exhibited good antioxidant activities against DPPH • (62%) and ABTS •+ (80%), as well as concentration-dependent (100-800 μg/mL) anti-inflammatory potential of 18-60% compared to standards, ascorbic acid or aspirin, respectively. Moreover, even low extract concentrations (10 μg/mL) inhibited the growth of Escherichia coli (1.9 ± 0.6 mm) and Pseudomonas aeruginosa (2.3 ± 0.7 mm), thus showing high antimicrobial and anti-inflammatory potential. GC-MS and LC-MS analyses identified 31 and 16 components, respectively, of which selected compounds were used to evaluate the interaction between key receptors (AKT-1, COX-2, and HER-2) of breast cancer based on binding energy (ΔG) and inhibition constant (K i ). The results indicate that bioactive compounds from P. dicoccos have potential against breast cancer cells, but further evaluations are needed.

The redox metabolic paradigm of murburn concept advocates that diffusible reactive species (DRS, particularly oxygen-centric radicals) are mainstays of physiology, and not mere pathological manifestations. The murburn purview of cellular function also integrates the essential principles of bioenergetics, thermogenesis, homeostasis, electrophysiology, and coherence. In this context, any enzyme that generates/modulates/utilizes/sustains DRS functionality is called a murzyme. We have demonstrated that several water-soluble (peroxidases, lactate dehydrogenase, hemogoblin, etc.) and membrane-embedded (Complexes I-V in mitochondria, Photosystems I/II in chloroplasts, rhodopsin/transducin in rod cells, etc.) proteins serve as murzymes. The membrane protein of Na,K-ATPase (NKA, also known as sodium-potassium pump) is the focus of this article, owing to its centrality in neuro-cardio-musculo electrophysiology. Herein, via a series of critical queries starting from the geometric/spatio-temporal considerations of diffusion/mass transfer of solutes in cells to an update on structural/distributional features of NKA in diverse cellular systems, and from various mechanistic aspects of ion-transport (thermodynamics, osmoregulation, evolutionary dictates, etc.) to assays/explanations of inhibitory principles like cardiotonic steroids (CTS), we first highlight some unresolved problems in the field. Thereafter, we propose and apply a minimalist murburn model of trans-membrane ion-differentiation by NKA to address the physiological inhibitory effects of trans-dermal peptide, lithium ion, volatile anesthetics, confirmed interfacial DRS + proton modulators like nitrophenolics and unsaturated fatty acid, and the diverse classes of molecules like CTS, arginine, oximes, etc. These explanations find a pan-systemic connectivity with the inhibitions/uncouplings of other membrane proteins in cells., (© 2022 Wiley Periodicals LLC.)

The advent of improved structural biology protocols and bioinformatics methodologies have provided paradigm-shifting insights on metabolic or physiological processes catalyzed by homo-/hetero- proteins (super)complexes embedded in phospholipid membranes of cells/organelles. In this panoramic review, we succinctly elucidate the structural features of select redox proteins from four systems: hepatocyte/adrenal cortex endoplasmic reticulum (microsomes), inner mitochondrial membrane (cristae), thylakoid membrane (grana), and in the flattened disks of rod/cone cells (in retina). Besides catalyzing fast/crucial (photo)chemical reactions, these proteins utilize the redox-active diatomic gaseous molecule of oxygen, the elixir of aerobic life. Quite contrary to extant perceptions that invoke primarily deterministic affinity-binding or conformation-change based "proton-pump"/"serial electron-relay" type roles, we advocate murzyme functions for the membrane-embedded proteins in these systems. Murzymes are proteins that generate/stabilize/utilize diffusible reactive (oxygen) species (DRS/DROS) based activities. Herein, we present a brief compendium of the recently revealed wealth of structural information and mechanistic concepts on how the membrane proteins use DRS/DROS to aid 'effective charge separation' and facilitate trans-membrane dynamics of diverse species in milieu, thereby enabling the cells to function as 'simple chemical engines'., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Isatin (1H-indole-2,3-dione)-containing compounds have been shown to possess several remarkable biological activities. We had previously explored a few isatin-based imidazole derivatives for their predicted dual activity against both inflammation and cancer. We explored 47 different isatin-based derivatives (IBDs) for other potential biological activities using in silico tools and found them to possess anti-viral activity. Using AutoDock tools, the binding site, binding energy, inhibitory constant/ K i and receptor-ligand interactions for each of the compounds were analyzed against SARS-CoV-2 RNA-dependent RNA polymerase (RdRp). The partition coefficient (logP) values were predicted using MedChem Designer tool. Based on the best K i , binding energy and the ideal range of logP (between 1.0 and 3.0), 10 out of total 47 compounds were deemed to be prospective RdRp inhibitors. Some of these compounds gave better K i , binding energy and logP values when compared to standard RdRp inhibitors, such as remdesivir (REM) ( K i = 15.61 μM, logP = 2.2; binding energy = -6.95), a clinically approved RdRp inhibitor and nine other RdRp inhibitors. The results showed that the 10 selected IBDs could be further explored. Molecular dynamics simulations (MDSs) showed that the selected RdRp-IBD complexes were highly stable compared to the native RdRp and RdRp-REM complex during 100 ns time periods. DFT studies were performed for the compounds 16a, 24a, 28a, 38a and 40a, to evaluate the charge transfer mechanism for the interactions between the IBDs and the RdRp residues. Among these, ADME profiling revealed that 28a is a possible lead compound which can be explored further for anti-RdRp activity in vitro . Communicated by Ramaswamy H. Sarma.

The classical paradigm of visual physiology comprises of the following features: (i) rod/cone cells located at the rear end of the retina serve as the primary transducers of incoming photo-information, (ii) cis-trans retinal (C 20 H 28 O) transformations on rhodopsin act as the transduction switch to generate a transmittable signal, (iii) signal amplification occurs via GDP-GTP exchange at transducin, and (iv) the amplified signal is relayed (as an action potential) as a flux-based ripple of Na-K ions along the axons of neurons. Fundamental physical principles, chemical kinetics, and awareness of architecture of eye/retina prompt a questioning of these classical assumptions. In lieu, based on experimental and in silico findings, a simple space-time resolved murburn model for the physiology of phototransduction in the retina is presented wherein molecular oxygen plays key roles. It is advocated that: (a) photo-induced oxygen to superoxide conversion serves as the key step in signal transduction in the visual cycle, (b) all photoactive cells of the retina serve as photoreceptors and rods/cones serve as the ultimate electron source in the retina (deriving oxygen and nutrients from retinal pigmented epithelium), (c) signal amplification is through superoxide mediated phosphorylation of GDP bound to inactive transducin, thereby activating a GDP-based cascade (a new mechanism for trimeric G-proteins), and (d) signal relay is primarily an electron movement along the neuron, from dendritic source to synaptic sink. In particular, we specify the roles for the various modules of transducin and GDP-based activation of phosphodiesterase-6 in the physiology of visual transduction., (© 2022 Wiley Periodicals LLC.)

It is unresolved why lactate is transported to the liver for further utilization within the physiological purview of Cori cycle, when muscles have more lactate dehydrogenase (LDH) than liver. We point out that the answer lies in thermodynamics/equilibriums. While the utilization of NADH for the reduction of pyruvate to lactate can be mediated via the classical mechanism, the oxidation of lactate (with/without the uphill reduction of NAD + ) necessitates alternative physiological approaches. The latter pathway occurs via interactive equilibriums involving the enzyme, protons and oxygen or diffusible reactive oxygen species (DROS). Since liver has high DROS, the murburn activity at LDH would enable the cellular system to tide over the unfavorable energy barriers of the forward reaction (~476 kJ/mol; earlier miscalculated as ~26 kJ/mole). Further, the new mechanism does not necessitate any "smart decision-making" or sophisticated control by/of proteins. The DROS-based murburn theory explains the invariant active-site structure of LDH isozymes and their multimeric nature. The theoretical insights, in silico evidence and analyses of literature herein also enrich our understanding of the underpinnings of "lactic acidosis" (lowering of physiological pH accompanied by lactate production), Warburg effect (increased lactate production at high pO 2 by cancer cells) and approach for cancer therapy., (© 2021 Wiley Periodicals LLC.)

We recently proposed a diffusible reactive (oxygen) species (DRS/DROS) based function for cytochrome b complexes (CBC) and quinones (Q)/quinols (QH 2 ) in the murburn model of bioenergetics. This proposal is in direct conflict with the classical purview of Q-cycle. Via extensive analyses of the structure-function correlations of membrane-quinones/quinols and proteins, we present qualitative and quantitative arguments to infer that the classical model cannot explain the energetics, kinetics, mechanism and probabilistic considerations. Therefore, it is proposed that Q-cycle is neither necessary nor feasible at CBCs. In contrast, we substantiate that the murburn model explains: (a) crucial structural data of CBCs, (b) why quinones/quinols are utilized in bioenergetic membranes, (c) how trans-membrane potential is generated owing to effective charge separation at CBCs, (d) mobility data of O 2 , DRS, Q/QH 2 , and (e) utility of other reaction/membrane components. Further, the murburn model also accommodates the absence of quinones in anaerobic Archaea, wherein methanophenazines are prevalent. The work mandates that the textbooks and research agendas are refreshed to reflect the new perception. SIGNIFICANCE: The current article must be seen as a critical and detailed analysis of the role and working mechanism of quinone (Q) /quinols (QH 2 ) in bioenergetic membranes. In the classical model, QH 2 are perceived as highly mobile electron-transport agents that bind and donate electrons to cytochrome b complexes (CBCs), using sophisticated electronic circuitries, in order to recycle Q and pump protons. The classical perception sees radicals (such as Q*-, O 2 *-, etc., also called diffusible reactive species, DRS) as wasteful or toxic (patho) physiological manifestations. It is highlighted herein that QH 2 has low mobility and matrix has little protons to pump. New insights from the structural analyses of diverse CBCs and quinols, in conjunction with murburn reaction thermodynamics suggest that the electrons from substrates/quinols are effectively utilized via DRS. This perception fits into a much broader analysis of 1 and 2 electron transfers in overall redox metabolism, as recently brought out by the murburn model, wherein DRS are considered obligatory ingredients of physiology. Thus, the findings mandate a reorientation in the pertinent research field., (© 2022 John Wiley & Sons Ltd.)

In the light reaction of oxygenic photosynthesis, plastocyanin (PC) and ferredoxins (Fd) are small/diffusible redox-active proteins playing key roles in electron transfer/transport phenomena. In the Z-scheme mechanistic purview, they are considered as specific affinity binding-based electron-relay agents, linking the functions of Cytochrome b 6 f (Cyt. b 6 f ), Photosystem I (PS I) and Fd:NADPH oxidoreductase (FNR). The murburn explanation for photolytic photophosphorylation deems PC/Fd as generic 'redox capacitors', temporally accepting and releasing one-electron equivalents in reaction milieu. Herein, we explore the two theories with respect to structural, distributional and functional aspects of PC/Fd. Amino acid residues located on the surface loci of key patches of PC/Fd vary in electrostatic/contour (topography) signatures. Crystal structures of four different complexes each of Cyt. f -PC and Fd-FNR show little conservation in the contact-surfaces, thereby discrediting 'affinity binding-based electron transfers (ET)' as an evolutionary logic. Further, thermodynamic and kinetic data of wildtype and mutant proteins interactions do not align with Z-scheme. Furthermore, micromolar physiological concentrations of PC and the non-conducive architecture of chloroplasts render the classical model untenable. In the murburn model, as PC is optional, the observation that plants lacking PC survive and grow is justified. Further, the low physiological concentration/distribution of PC in chloroplast lumen/stroma is supported by murburn equilibriums, as higher concentrations would limit electron transfers. Thus, structural evidence, interactive dynamics with redox partners and physiological distribution/role of PC/Fd support the murburn perspective that these proteins serve as generic redox-capacitors in chloroplasts.Communicated by Ramaswamy H. Sarma.