The Impact of the Energy Transition and Sustainable Development Goals on Mineral Resource Availability in Africa

Understanding and predicting the impact of the global energy transition and the United Nations Sustainable Development Goals (SDGs) on global mineral demand and African supply is challenging. This study uses a resource nexus approach to investigate and analyze the impact of this transition on energy and water demand and CO2 emissions using three annual material demand scenarios. The results indicate that African mining will consume more energy by 2050, leading to an increase in cumulative demand for energy (from 98 to 14,577 TWh) and water (from 15,013 to 223,000 million m3), as well as CO2 emissions (1318 and 19,561 Gg CO2e). In contrast, only a modest increase in energy demand (207 TWh) will be required by 2050 to achieve the SDGs. Therefore, the African mining industry should reduce its energy consumption and invest more in the renewable energy sector to support the global energy transition.

Kinetics of Extraction of <i>β</i>-Carotene from Tray Dried Carrots by Using Supercritical Fluid Extraction Technique

β-carotene acts as an antioxidant and is receiving growing interest due to its ability as protecting agent against heart diseases, cancer and strengthening effect on red blood cells. The main aim of this work was to study the kinetics of the supercritical fluid extraction of β-carotene from tray dried carrots at 40℃, 50℃ and 55℃ and 30, 35 and 40 MPa at SC-CO2 flow rate of 2.0 L/min for extraction time of up to 6 h. It was observed that the concentration of β-carotene in the extract increased with pressure, temperature and extraction time. The results indicated that yield was found to be maximum at 45℃ and 35 MPa at 2 L/min SC-CO2 flow rate. Concentration of β-carotene in the extract increased with SC-CO2 flow rate. Weibull distribution model described adequately the kinetics of extraction of β-carotene from carrots.

Effect of Pulsed Ultraviolet Light on the Total Phenol Content of Elderberry (<i>Sambucus nigra</i>) Fruit

The changes in total polyphenolics in elderberry (Sambucus nigra) following treatment with various doses of pulsed ultraviolet rays (UV) were investigated. Four pulsed UV durations (5, 10, 20, 30 seconds) at three energy dosages (4500, 6000, 11,000 J/m2/pulse) were considered for the research. All treated elderberry fruits were incubated for 24 h at room temperature (25℃) following treatment to ensure enough response duration for enhanced development of polyphenols by the berries. The highest increase in total phenolics around 50% was found with 11,000 J/m2/pulse for a 10 seconds treatment while nearly 40% increase in total phenolics was found at an energy dosage of 11,000 J/m2/pulse after 5 seconds exposure. Even though most of the treatments indicated an increase in total polyphenols, some treatment expressed a decrease in phenolics content when compared to untreated fruits.

Biochar Based Inoculants Improve Soybean Growth and Nodulation

Most rhizobial inoculants that stimulate legume yield are applied with carriers that enhance root contact. The physicochemical properties of biochar are suitable for microbial growth, and it could be an alternative to peat, which comes from decreasing reserves but is the commonest solid inoculant carrier. The aim of the current research was to evaluate biochars as carriers of bradyrhizobia in solid inoculant and as coatings for seeds. Biochars and peat were inoculated with Bradyrhizobium japonicum strain 532C and storage time was assessed. A seed coating system was developed using biochar, bacteria liquid culture, water, and guar gum. The viability of bacteria in the coating and in solid biochar was evaluated at 4°C and 21°C. Two biochars were selected for a germination assay. Finally, greenhouse experimentation investigated the effect of biochar inoculant and seed coating on soybean growth and nutrient uptake. The storage time experiment showed that not all biochars equally sustain bacteria survival over time. The germination assay demonstrated that biochar seed coating had no effect on soybean germination. Greenhouse experimentation indicated that the effect of Pyrovac biochar on soybean growth characteristics and nutrient uptake depended on the fertilizer. The main finding was that biochar solid inoculant positively affected plant growth metrics, root characteristics, and the chemical composition of plants supplied with N-free nutrient solution.

Effect of Ripening Stages on Basic Deep-Fat Frying Qualities of Plantain Chips

Plantains （Musa paradisiaca L.） are a major food staple in West Africa and are cooked in various forms. The objective of this work was to evaluate the frying characteristics of plantains at different stages of ripening. The plantains used in the study were at the unripe stage through four different ripening stages. The samples were peeled and sliced into 2 mm thickness and blanched in hot water at 70 ℃ for 3 min. The slices were then deep flied in canola oil at 180 ℃. The result showed that ripening stage significantly affected moisture loss and fat absorption profiles of the plantain chips. Fully ripened plantain absorbed up to 34% （db） oil during 4 min frying, much higher than unripe plantain. The oil uptake and moisture loss during frying of the plantain chip samples were modelled using 1st order kinetics. The kinetic parameters including rates of moisture loss and oil uptake varied according to the different stages of ripening. Ripening had a significant effect on the colour lightness （L） of the chips. Similarly, the redness （a）, the yellowness （b） and textural characteristics were significantly affected by ripening stage.

Reduction in Water Stress for Tree Saplings Using Hydrogels in Soil

The effect of soil amendment with hydrogel on reducing water stress was tested for Siberian elm (Ulmus pumila) and silver maple (Acer saccharinum) saplings. The trees were planted in soils with one of two concentrations of hydrogel (0.5% or 1% dry weight) as compared to the control soil (0% of hydrogel) and watered either daily, weekly, or bi-weekly. Growth was monitored by measuring height and stem diameter. Stress was monitored by measuring SPAD readings and normalized difference vegetation index (NDVI), as proxy measures of chlorophyll content and photosynthetic activity, respectively. Water stress decreased NDVI (p < 0.05) but did not have a significant effect on SPAD readings. Soil with 0.5% concentration of hydrogel was positively associated with greater height and NDVI (p < 0.01) for both maple and elm trees. Hydrogels had a species-specific effect on SPAD readings. The interaction between hydrogel concentration and the watering regime had a significant effect on the height and NDVI (p < 0.01) of elms, but not maples. The improved performance of water-stressed tree saplings in hydrogel-amended soils was presumably due to the ability of hydrogels to absorb and then gradually release water and nutrients. This is of special interest for urban foresters, because water stress and nutrient deficiency are two important growth-limiting factors for street trees.

Microwave Drying of Flax Fibre at Controlled Temperatures

Drying is essential for the production of fibre after retting process. Flax fibre was subjected to microwave drying at controlled temperatures to study the change in drying rate and qualities. The rate of drying was then compared with conventional hot air drying. The product temperature was maintained at 40 ℃, 60 ℃or 80 ℃ for both microwave and hot air drying. The initial moisture content of flax fibre was about 60% （wet basis）. The microwave drying was conducted in a microwave apparatus which recorded mass, product temperature, incident microwave power, reflected microwave power and inlet/outlet air temperature. The final moisture content was set to 9% （wet basis）. Microwave-convective drying ensured about 30% to 70% reduction of drying time for drying flax fibre as compared to hot air drying. Curve fitting with different mathematical models were carried out. While a significant difference in colorimeter-assessed co/our existed between microwave-convective dried flax fibre and hot air dried flax fibre. The tensile strength of flax fibre, measured with an Instron apparatus, increased with an increase in the processing temperature of both processes. Hot air dried flax fibre showed the greatest tensile strength and modulus of elasticity at processing temperatures of 60 ℃ and 80 ℃.

Litter decay in rangeland sites with varying history of human disturbance: a study with Hazargangi Chiltan mountain

Hazarganji Chiltan National Park in Balochistan, Pakistan was established in 1980 and the protected area was further extended in 1998. Large area of this mountain is still open for unmanaged human disturbances such as collection of wood for fuel purpose and livestock grazing. Removal of vegetation of rangelands has a significant negative impact on soil organic matter(SOM). This research evaluates litter decomposition in three sites of Hazarganji Chiltan mountain with varying history of human disturbances(unprotected site, young protected site and old protected site). Twigs of Pistacia khinjuk with approximately equal weight and length were placed in litter bags of mesh size 2 mm and were buried in 0-5 cm depth in three sites in January. Half of the twigs of each site received rain simulation in April, August, October, November and January while the other half of the twigs were subjected under natural conditions for 15 months. Twigs from each plot of each treatment of each site were collected from soil after every rain simulation in the previous month of experiment and were processed for weight loss assessment. Results showed that weight loss of twigs by decomposition was significantly higher in the soil of unprotected site as compared to other two sites and there was no difference between rain simulation and control treatments except that loss of weight of twigs of unprotected site was higher under control than rain simulation condition. To confirm that SOM was the major controlling factor for the decomposition of litter decay, soils of each site were collected and burned to remove SOM;thereafter, burned soil samples were mixed with homogenous powder of oven-dried native plants, incubated for 6 months and were provided with dissolved organic matter of the soils of each site. Results showed that there was no difference in the decomposition of litter between soils under controlled laboratory condition, which confirmed that SOM was a major controlling factor for the litter decay in soil under field conditions. The pyrosequencing analysis of the DNA of soils collected from three sites revealed the presence of bacterial species Thermovum composti.

Effect of sonication-cooking on the immunoreactivity of soy slurry from germinated soybeans

Soy proteins are globular in nature and are resistant to denaturation with lower intensity thermal treatments like cooking.Likewise,germination can also alter the protein structure through the activity of various enzymes and sonication can disrupt the molecular structure through cavitation and other ultrasound effects,and contribute to some reduction in immunoreactivity(IR)of allergens.This study evaluated the effects of germination and sonication pretreatment in combination with common cooking on lowering the soy allergen IR.Germination was carried out for up to 120 h and ultrasound sonication treatments were given for 20,40 and 60 min at room temperature.Cooking at 100 oC was carried out for 10 to 60 min.The soy allergen IR was evaluated using a commercial sandwich ELISA kit.The combined action of germination,sonication and cooking helped to reduce the soy allergen IR to single digit mg/L levels from the nearly 400 mg/L initial level in the 5%soy slurry(>99%reduction).These levels are lower than the reported threshold values of soy allergens in foods.In addition,the germination and ultrasound process was shown to reduce the anti-nutritional properties and enhance the phenolic and radical scavenging activity by over 50%.

A new perspective on functional redundancy and phylogenetic niche conservatism in soil microbial communities

Functional redundancy in soil microbial communities seems to contradict the notion that individual species have distinct metabolic niches in multi-species communities.All soil microbiota have the metabolic capacity for"basic"functions(e.g.,respiration and nitrogen and phosphorus cycling),but only a few soil microbiota participate in"rare"functions(e.g.,methanogenesis and mineralization of recalcitrant organic pollutants).The objective of this perspective paper is to use the phylogenetic niche conservatism theory as an explanation for the functional redundancy of soil microbiota.Phylogenetic niche conservatism is defined as the tendency for lineages to retain ancestral functional characteristics through evolutionary time-scales.The present-day soil microbiota is the result of a community assembly process that started when prokaryotes first appeared on Earth.For billions of years,microbiota have retained a highly conserved set of core genes that control the essential redox and biogeochemical reactions for life on Earth.These genes are passed from microbe to microbe,which contributes to functional redundancy in soil microbiota at the planetary scale.The assembly of microbial communities during soil formation is consistent with phylogenetic niche conservatism.Within a specific soil,the heterogeneous matrix provides an infinite number of sets of diverse environmental conditions,i.e.,niches that lead to the divergence of microbial species.The phylogenetic niche conservatism theory predicts that two or more microbial species diverging from the same clade will have an overlap in their niches,implying that they are functionally redundant in some of their metabolic processes.The endogenous genetic factors that constrain the adaptation of individuals and,thus,populations to changing environmental conditions constitute the core process of phylogenetic niche conservatism.Furthermore,the degree of functional redundancy in a particular soil is proportional to the complexity of the considered function.We conclude with a conceptual model that identifies six patterns of functional redundancy in soil microbial communities,consistent with the phylogenetic niche conservatism theory.

Earthworm functional groups are related to denitrifier activity in riparian soils

Riparian buffers,located in the transition zone between terrestrial and aquatic ecosystems,are a hotspot for nitrogen(N)removal through denitrification.Earthworms are abundant in riparian buffers and may enhance denitrification.This study investigated earthworm demographics of three earthworm functional groups(anecic,epigeic,and endogeic)and denitrifier activity in temporarily flooded and non-flooded riparian soils from April to October 2012 in southern Quebec,Canada.Nine earthworm species,mostly endogeic,were found in the temporarily flooded soil,while only six earthworm species were found in the non-flooded soil.On average,there were 11.7 times more earthworms with 12.4 times greater biomass(P<0.05)found in the temporarily flooded soil than in the non-flooded soil.The denitrification enzyme activity(DEA)was of similar magnitude in temporarily flooded and non-flooded soils,with temporal variation associated with rainfall patterns.Endogeic earthworm biomass was positively correlated(P<0.05)with DEA,while epigeic earthworm biomass was positively correlated(P<0.05)with 16S rRNA gene copies and nosZ gene copies from bacteria,indicating an association between earthworm functional groups and denitrifier activity in riparian soils.Stepwise multiple regressions showed that DEA in riparian soils could be predicted using soil moisture,inorganic N concentration,and earthworm functional groups,suggesting that endogeic and epigeic earthworms contributed to denitrifier activity in riparian soils.

Earthworm contributions to soil nitrogen supply in corn-soybean agroecosystems in Quebec, Canada

Accurately quantifying the soil nitrogen(N)supply in crop fields is essential for enabling environmentally sustainable and economically profitable crop production.It requires using field-based methods to account for the contribution of soil biota,including earthworms,to N mineralization in temperate agroecosystems.The direct contribution of earthworms to the soil N cycle is the N they release throughout their life and after death,and it can be estimated using the secondary production method.This study was conducted in 2014 and 2015 in two adjacent fields with annual corn-soybean rotation in Ste-Anne-de-Bellevue,Quebec,Canada.The cumulative biomass of Aporrectodea spp.in two no-till corn-soybean agroecosystems was determined,and the direct N flux from these earthworms was estimated during the corn and soybean phases of the rotation.Secondary production was estimated by sampling earthworms biweekly during April-June and September-November and inferring the change in earthworm biomass between sampling dates using a size frequency calculation.The N flux was calculated as the sum of the N released through excretion,during periods when earthworms were active,and from mortality.The secondary production of the Aporrectodea population was estimated to be 8-43 g ash-free dry weight m^(-2) year^(-1),and the N flux was 22-105 kg N ha^(-1 )year^(-1).The N flux was higher at the early vegetative growth stage,which is a period of high N demand for corn.These findings suggest that refining the N fertilization recommendation by accounting for soil N supplied by earthworms could potentially reduce fertilizer costs and environmental N losses.

C-reactive protein is differentially modulated by co-existing infections,vitamin deficiencies and maternal factors in pregnant and lactating indigenous Panamanian women

Background:The usefulness of C-reactive protein(CRP)as a non-specific marker of inflammation during pregnancy and lactation is unclear in impoverished populations where co-existing infections and vitamin deficiencies are common.Methods:This cross-sectional study in Panama recruited 120 pregnant and 99 lactating Ngäbe-Buglewomen from 14 communities in rural Panama.Obstetric history,indoor wood smoke exposure,fieldwork,BMI,vitamins A,B_(12),D,and folic acid,and inflammation markers(CRP,neutrophil/lymphocyte ratio(NLR),plateletcrit and cytokines)were measured.Multiple regressions explored both associations of CRP with other inflammatory markers and associations of CRP and elevated CRP based on trimester-specific cut-offs with maternal factors,infections and vitamin deficiencies.Results:CRP was higher in pregnancy(51.4±4.7 nmol/L)than lactation(27.8±3.5 nmol/L)and was elevated above trimester specific cut-offs in 21%of pregnant and 30%of lactating women.Vitamin deficiencies were common(vitamin A 29.6%;vitamin D 68.5%;vitamin B1268%;folic acid 25.5%)and over 50%of women had two or more concurrent deficiencies as well as multiple infections.Multiple regression models highlighted differences in variables associated with CRP between pregnancy and lactation.In pregnancy,CRP was positively associated with greater indoor wood smoke exposure,caries and hookworm and negatively associated with Ascaris and vaginal Lactobacillus and Bacteroides/Gardnerella scores.Consistent with this,greater wood smoke exposure,caries as well as higher diplococcal infection score increased the odds of trimester-elevated CRP concentrations whereas longer gestational age lowered the likelihood of a trimester-elevated CRP.During lactation,folic acid deficiency was associated with higher CRP whereas parity,number of eosinophils and Mobiluncus score were associated with lower CRP.Also,a higher BMI and Trichomonas vaginalis score increased the likelihood of an elevated CRP whereas higher parity and number of eosinophils were associated with lower likelihood of an elevated CRP.Conclusions:Infections both raise and lower CRP concentrations in pregnant and lactating mothers.Only folic acid deficiency during lactation was associated with higher CRP concentrations.Caution is required when interpreting CRP concentrations in pregnant and lactating women who have co-existing nutrient deficiencies and multiple infections.

Earthworm populations are stable in temperate agricultural soils receiving wood-based biochar

The application of decomposable organic residues such as manure and crop litter is generally beneficial to earthworms.There is an emerging interest in applying biochar,a carbonaceous product of pyrolysis,to temperate agricultural soils.The slow decomposition rate of biochar,which also contains ash and combustion byproducts,could be detrimental to earthworms.The objective of this study was to describe the earthworm populations in biochar-amended soils on a dairy farm in the St.Francis River watershed,Quebec,Canada.Earthworms were collected from replicated field plots under cereal production.Site A received three wood-based biochar types at two application rates(5 and 10 t ha^(-1) biochar)plus an unamended control,while Site B received wood-based biochar(7.5 t ha^(-1) biochar),dairy cattle slurry(10 t ha^(-1) manure),or a combination of the biochar and manure rates plus an unamended control.Earthworms were collected by hand sorting and formaldehyde expulsion from soil pits.Three species,Aporrectodea turgida,Aporrectodea tuberculata,and Lumbricus rubellus,were found at the sites,and Aporrectodea was the dominant genus.Biochar sources,rates,and application with dairy slurry did not affect the earthworm population,which had 52-218 individuals m^(-2) in 2010 and 4-96 individuals m^(-2) in 2011.The seasonal variation in earthworm population may be due to flooding in the spring of 2011,which apparently interfered with earthworm reproduction.The similarity in earthworm abundance and biomass in plots with and without wood-based biochar leads to the conclusion that earthworm populations are stable in biochar-amended soils in this cold,humid temperate region.

Synchrotron X-ray microtomography and multifractal analysis for the characterization of pore structure and distribution in softwood pellet biochar

Biochar pores in the micrometer range(1-100μm)derive from cellular structures of the plant biomass subjected to pyrolysis or can be the result of mechanical processing,such as pelleting.In this study,synchrotron X-ray microtomography was used to investigate the internal pore structure of softwood pellet biochar produced by slow pyrolysis at 550 and 700°C.The microtomographic data sets consisted of 2025 images of 2560×2560 voxels with a voxel side length of 0.87μm.The three-dimensional reconstructions revealed that pelleting and pyrolysis significantly altered the pore structures of the wood feedstock,creating a network of connected pores between fragments that resembled the wood morphology.While higher pyrolysis temperature increased the specific surface area(as determined by BET nitrogen adsorption),it did not affect the total observed porosity.Multifractal analysis was applied to assess the characteristics of the frequency distribution of pores along each of the three dimensions of reconstructed images of five softwood pellet biochar samples.The resulting singular-ity and Rényi spectra(generalized dimensions)indicated that the distribution of porosity had monofractal scaling behavior,was homogeneous within the analyzed volumes and consistent between replicate samples.Moreover,the pore distributions were isotropic(direction-independent),which is in strong contrast with the anisotropic pore structure of wood.As pores at the scale analyzed in this study are relevant,for example,for the supply of plant accessible water and habitable space for microorganisms,our findings combined with the ability to reproduce biochar with such pore distribution offer substantial advantages in various biochar applications.

Physiological evidence of integrin-antibody reactive proteins influencing the innate cellular immune responses of larval Galleria mellonella hemocytes

Larval Galleria melonella(L.)hemocytes form microaggregates in response to stimulation by Gram-positive bacteria Hemocyte adhesion to foreign materials is mediated by the CAMP/protein kinase A pathway and the B-subunit of cholera toxin using a cAMP-independent mechanism.Cholera toxin-induced microaggregation was inhibited by the integrin inhibitory RGDS peptide,implying integrins may be part of the mechanism.Based on the types of mammalian integrin-antibody reactive proteins affecting hemocyte adhesion and bacterial-induced responses ars,ory,Ai,and B3 subunits occred on both granular cell and plasmatocyte hemocyte subtypes.A fluorescent band representing the binding of rabbit as-integrin subunit antibodies occurred between adhering heterotypic hemocytes.The frequency of the bands was increased by cholera toxin.The as andβrabbit integrin subunit antibodies inhibited removal of Bacillus subtilis(Cohn)from the hemolymph in vivo,A as ir-specific synthetic peptide blocker similarly diminished hemocyte function whereas the 0v Bs-specific inhibitory peptide and the corresponding integrin subunit antibodies did not influence nonself hemocyte activities.Western blots revealed several proteins reacting with a given integrin-antibody subtype.Thus integrin-antibody reactive proteins(which may include integrins)with possible as and B epitopes modulate immediate hemocyte function.Confocal microscopy established plasmatocyte adhesion to and rosetting over substrata followved by granular cell microaggregate adhesion to plasmatocytes during early stage nodulation.

Water absorption characteristics of Canarium Schweinfurthii fruits

Water absorption characteristics of two varieties of Canarium Schweinfurthii engl.fruit(Canarium Schweinfurthii engl.long and short)essential for predicting their suitable absorption conditions was investigated at three different temperatures(35,50,65
C).Increase in moisture content of the fruits was measured at one-hour interval until constant values were obtained after five successive intervals of moisture measurements.Loss of soluble constituents,textural and nutritive qualities of the rehydrated products and their thermodynamic behavior were also measured and calculated.The results obtained revealed that saturation time for 35,50 and 65
C of long and short varieties are 14,18 and 40 h and 18,22 and 36 h respectively.Rate of absorption of the fruits differ significantly(p>0.05)with temperature and not with the variety.Water absorption rate of Canarium Schweinfurthii engl.long and short varieties are 2.71 and 2.25 kg/h respectively.The moisture bearing capacity,textural,and nutritive qualities of the reconstituted products showed no significant difference among varieties at different temperatures used.Fruits soaked at 35
C produced reusable residual water,retained their nutritive values and soluble constituent more than other soaking temperatures studied.However,the absorption reaction is endothermic with negative entropy and Gibbs energy values were above zero.Midilli model had the best quality for describing the absorption characteristics of both Canarium Schweifurthii engl.fruits.