428 research outputs found
A Review of Indigenous Food Crops in Africa and the Implications for more Sustainable and Healthy Food Systems
Indigenous and traditional foods crops (ITFCs) have multiple uses within society, and most notably have an important role to play in the attempt to diversify the food in order to enhance food and nutrition security. However, research suggests that the benefits and value of indigenous foods within the South African and the African context have not been fully understood and synthesized. Their potential value to the African food system could be enhanced if their benefits were explored more comprehensively. This synthesis presents a literature review relating to underutilized indigenous crop species and foods in Africa. It organizes the findings into four main contributions, nutritional, environmental, economic, and social-cultural, in line with key themes of a sustainable food system framework. It also goes on to unpack the benefits and challenges associated with ITFCs under these themes. A major obstacle is that people are not valuing indigenous foods and the potential benefit that can be derived from using them is thus neglected. Furthermore, knowledge is being lost from one generation to the next, with potentially dire implications for long-term sustainable food security. The results show the need to recognize and enable indigenous foods as a key resource in ensuring healthy food systems in the African continent
Polycyclic Aromatic Hydrocarbons in Smokes of Two Biomasses Used For Domestic Cooking In Nigeria
Domestic cooking of foods is predominantly carried out in Nigeria through the burning of different types of biomass. Smoke resulting from such burning in most cases is been inhaled by people in the immediate environment where the cooking exercise is taking place. Where incomplete combustion occurs, the smoke may carry some products of incomplete combustion; prominent among these are polycyclic aromatic hydrocarbons (PAHs). Some of these PAHs have been implicated for various health challenges such as cancer. Incomplete combustion of fuels is known to generate PAHs. Smokes from some biomasses have also been established to contain some PAHs.This group of organic compounds is of global environmental concern. The composition and concentration of PAHs in the smokes of two biomasses used in domestic cooking in Nigeria were determined. For this purpose, a pyrolytic unit was fabricated and used for the pyrolysis of Wood Charcoal (WC) and Palm Kernel Shell (PKS). Gases resulting from their pyrolysis were collected and analyzed using Gas Chromatography (GC). The results of GC analysis showed that the composition and concentration of PAHs in gas obtained from the pyrolysis of WC were; Acenaphthene (0.218µg/cm3), Fluorene (0.573 µg/cm3), Phenanthrene (13.305 µg/cm3), Anthracene (0.552 µg/cm3), Fluoranthene (9.069 µg/cm3), Pyrene (8.677 µg/cm3), Benzo(a)anthracene (0.660 µg/cm3), Chrysene (0.660 µg/cm3), Benzo(b)Fluorene (0.593 µg/cm3) and Benzo(k)fluoranthene (0.853 µg/cm3). While the composition and concentration of PAHs in gas obtained from the pyrolysis of PKS were; Acenaphthene (0.208 µg/cm3), Fluorene (0.567 µg/cm3), Phenanthrene (14.190 µg/cm3), Anthracene (0.527 µg/cm3), Fluoranthene (11.808 µg/cm3), Pyrene (9.794 µg/cm3), Benzo(a)anthracene (0.448 µg/cm3), Chrysene (0.415 µg/cm3), Benzo(b)Fluoranthene (0.346 µg/cm3) and Benzo(k)fluoranthene (0.215 µg/cm3). Source diagnostic ratios calculated for the PAHs found in the pyrolytic gases of the biomasses showed that these PAHs were of pyrogenic origin, thus confirming that they were generated from the pyrolysis of WC and PKS Key words: Biomass, pyrolysis, GC, Smoke and PAH
Total Anti-Oxidant Capacity, Flavonoid, Phenolic Acid And Polyphenol Content In Ten Selected Species Of Zingiberaceae Rhizomes
Background: Natural products such as herbs, fruits, spices, beverages, vegetables are becoming more popular among scientific community and consumers because of their potential to arrest the effect of free radicals in human system. This study determined the total antioxidant capacity of ten selected species of Zingiberaceae (Ginger) used as spices and for medicinal purposes in Southeast Asia.Materials and Methods: Methanol was used as the extraction solvent, 2,2 – diphenyl -1- picrylhydrazil (DPPH) for free radical scavenging activity and ferric reducing antioxidant power (FRAP) assays. Phenolic compounds were measured using Total flavonoid, Phenolic acid and Polyphenols content assay to evaluate the quality of the antioxidant capacity of the rhizomes and vitamin C as positive control.Results: The results obtained revealed that Curcuma longa and Zingiber officinale had the highest free radical scavenging capacity of 270.07mg/TE/g DW and 266.95mg/TE/g DW and FRAP assay, Curcuma longa and Zingiber officinale also gave the highest ferric reducing power of 231.73mg/TE/g DW and 176.26mg/TE/g DW respectively. For Phenolic compounds, Curcuma longa and Curcuma xanthorrhiza gave the highest values of flavonoid (741.36mg/NGN/g DW and 220.53mg/NGN/g DW), phenolic acid (42.71mg/GAE/g DW and 22.03mg/GAE/g DW) and polyphenols(39.38mg/GAE/g DW and 38.01mg/GAE/g DW) respectively. Significant and positive linear correlations were found between Total antioxidant capacity and Phenolic compounds (R = 0.65 – 0.96). Conclusion: This study provides evidence that extracts of Zingiberaceae (Ginger) rhizomes are a potential source of natural antioxidants and could serve as basis for future drugs and food supplementsKey words: Zingibearaceae, Antioxidant, Free Radical, Oxidative stress, DPPH, Flavonoid, Phenolic acid, Polypheno
Prevalence of Gastro-intestinal Parasites of Cattle in Ogbomoso, Oyo State
A study was carried out on the prevalence of gastrointestinal (GI) nematodes infection in naturally infected cattle in Ogbomoso area of Oyo State using standard parasitological techniques. The results indicated that out of the 1000 cattle examined, 30(3%) were infected and parasites identified were Haemonchus contortus 8(26.7%), Trichostrongylus spp 13(43.3%) and Cooperia spp 2(6.7%) as single infection. Mixed infections involved Haemonchus contortus with Trichostrongylus spp 5(16.7%), H. contortus with Cooperia spp 2(6.7%) being statistically significant (p<0.05).The prevalence rates of GI nematodes based on the sex and age of the cattle were 3.02%, 2.97%, 3.2% and 2.8% in adult, young, male and female animals respectively, with the highest faecal egg counts in adult animals with no statistical significance difference (p>0.05). Both female and male cattle were more infected with Haemonchus contortus with 5 (62.5%) each, while only male and young cattle were infected with Cooperia spp 2 (100%) and 1 (50%) respectively. The highest rate of mixed infection occurred in adult cattle with Haemonchus contortus and Trichostrongylus spp 2 (100%) followed by Haemonchus contortus and Cooperia spp in male 4 (80%) and adult 3 (60%).The variation in the prevalence of GI nematodes among sex and age groups within systems can be used as an entry point towards rational use of anthelmintics for each management system. More studies on seasonal transmission pattern of all these parasites are required in order to design rational, economic and locally sustainable parasite control programmes.Key words: Prevalence, gastro-intestinal parasites, Cattle, Ogbomos
Physicochemical Quality and Genotoxic Potential of Wastewater Generated by Canteen Complex
Canteens generate high volumes of wastewater that should constantly be subjected to physicochemical and genotoxicity screening. In this study, the wastewater generated by a canteen complex was screened for physicochemical properties and genotoxic potential using standard procedures and Allium cepa chromosome assay. Results showed that the wastewater had total suspended solids, total dissolved solids, and total hardness concentrations of 120.70 mg/l, 554.50 mg/l, and 500.00 mg/l, respectively. The chloride concentration of the wastewater (7873.60 mg/l) was much higher than the recommended limit of 250 mg/l. The wastewater inhibited root growth in A. cepa at 0.1%, 1%, 10%, 25%, 50%, and 100% concentrations but promoted root growth at 2% and 5% concentrations. The wastewater was highly mitodepressive, with mitotic inhibition generally increasing with rising concentrations. The major chromosomal aberrations observed in A. cepa exposed to different concentrations of canteen wastewater were vagrant, sticky, and bridged chromosomes. No chromosomal aberration was observed in onion roots exposed to water (control). The differences in total chromosomal aberrations across wastewater concentrations were not statistically significant (P > 0.05). In view of these results, the practice of discharging untreated canteen wastewater into drainage canals may not be environmentally sustainable
Are adults just big kids? Can the newer paediatric weight estimation systems be used in adults?
Background. The weight of a patient is an important variable that impacts on their medical care. Although some drugs are prescribed on a so-called ‘adult dose’ basis, we know that adults come in all shapes and sizes – a ‘one-dose-fits-all’ approach is not necessarily appropriate. As a measured weight may not always be available, an alternative method of accurately estimating weight is required.Objectives. To assess and compare the accuracy of weight estimations in adults by patient self-estimation, the Mercy method, Buckley method, Broca index and PAWPER XL-MAC (paediatric advanced weight prediction in the emergency room eXtra length/eXtra large mid-arm circumference) method.Methods. This was a prospective, cross-sectional study conducted at a tertiary academic hospital in a metropolitan area of Johannesburg, South Africa. Anthropometric variables of height, abdominal circumference, thigh circumference, mid-arm circumference and humeral length were measured. These variables were then applied to the various weight estimation methods and compared with the patient’s actual weight.Results. There were 188 adult patients included in the study. None of the methodologies evaluated in this study achieved the recommended >70% of weight estimations within 10% of the patient’s actual weight (PW10). The Mercy method was the closest to achieving greater than the recommended 95% for weight estimation falling within 20% of the patient’s actual weight (PW20). The PW20 for the Mercy method was 91.5%. The PAWPER XL-MAC and patient self-estimate methods achieved a PW20 of 85.1% and 86.1%, respectively. The Broca and Buckley methods performed poorly overall.Conclusions. None of the evaluated weight estimation methodologies was accurate enough for use in adult weight estimation. The Mercy and PAWPER XL-MAC methodologies both showed significant promise for use in adult weight estimation, but need further refinement. Although patient self-estimates were similarly accurate to those found in previous studies, they were not an accurate option; self-estimations would remain the first choice if the patient was able to provide such an estimation. The Broca index and Buckley method cannot be recommended owing to their poor performance
Improving distributed video coding side information by intelligently combining macro-blocks from multiple algorithms
The performance of distributed video coding (DVC) greatly relies on the quality of Side information (SI). This paper investigates a novel way of producing SI by intelligently combining macroblocks (MB) produced by two SI generation algorithms, namely higher-order piecewise temporal trajectory interpolation (HOPTTI) and adaptive overlapped block motion compensation (AOBMC). The two algorithms address the problem differently. HOPTTI attempts to improve the motion estimation using higher order trajectory interpolation while AOMBC addresses the blocking and overlapping problem caused by inaccurate block matching. By judiciously selecting when to incorporate AOBMC with HOPTTI, it would give a peak signal-to-noise ratio (PSNR) improvement in SI quality. Two switching mechanisms, which exploit the spatial-temporal correlation at the macro-block level, have been investigated and the RST-based intelligent mode switching (IMS) algorithm is found to produce enhanced SI quality. Experimental results show that the basic mode switching algorithm gives a PSNR improvement of up to 1.8dB in SI quality compared to using only HOPTTI. The more intelligent RST-based switching provides a further PSNR enhancement of up to 1.1dB for certain test sequences
Testosterone reactivity to competition and competitive endurance in men and women
Transient shifts in testosterone occur during competition and are thought to positively influence dominance behavior aimed at enhancing social status. However, individual differences in testosterone reactivity to status contests have not been well-studied in relation to real-time expressions of competitive behavior among men and women. This research tests the association between changes in endogenous testosterone levels during competition and performance in terms of competitive endurance. Participant sex, social presence, and relative status outcomes (e.g., winning vs. losing) are tested as moderators of this relationship. In two studies, men and women (total NÂ =Â 398) competed in the competitive will task (timed weight-holding) either individually or in the presence of an opponent (Study 1) or as a team with and without the presence of a competitor team (Study 2). Results showed a positive relationship between testosterone reactivity and performance for men, particularly those who won or ranked highest among their group - with increasing testosterone predicting better performance and decreasing testosterone predicting worse performance. For women, the effect only emerged among individuals who competed in dyads and lost. In Study 2, an exploratory mediation analysis revealed that individual differences in trait dominance predicted both testosterone reactivity to competition and task performance, with testosterone reactivity (moderated by sex and status outcome) partially explaining the direct relationship between dominance-related traits and behavior. Our goal was to examine testosterone reactivity in relation to real-time competitive effort and highlight the potential role of this relationship in explaining how individual differences in trait dominance produce competitive behavior
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