Drivers of technical efficiency in cassava processing in Nigeria: implications for a commercializing food sector

Open Access JournalRésumé La plupart des politiques agricoles au Nigeria ont pour objectif d’intégrer les petits agriculteurs dans l'économie de marché. Au cours de la dernière décennie, le Nigéria a connu un important apport de capitaux privés et publics dans la promotion des unités de transformation du manioc de petite échelle. Cette étude utilise la fonction de frontière stochastique et des données d’entrées/sorties pour mesurer et expliquer les efficacités techniques (ET) de 274 entreprises de petite et moyenne taille. L'étude a montré que les entreprises de transformation du manioc ont une efficacité technique moyenne de 43% t, indiquant qu'une très grande proportion de la valeur de la production (57%) est perdue en raison des inefficacités propres aux entreprises. Les entreprises de transformation de la zone du Centre-Nord ont enregistré l’efficacité technique moyenne la plus élevée (61%), suivies par celle de la zone du Sud-Est / Sud-Ouest (42%) et enfin celle du Sud-Sud (26%). Les valeurs de l’ ET étaient inférieures à 80% pour environ 85% des entreprises échantillonnées. Les efficacités techniques sont influencées par la classification de l'entreprise (petite ou moyenne taille, propriété individuelle ou propriété familiale), les facteurs sociaux (interactions avec d'autres acteurs), économiques (nombre de produits, de clients ou de commandes reçues) et la participation à un atelier de formation. Les gouvernements et les institutions ayant un rôle statutaire dans la promotion des chaînes de valeurs agricoles devraient envisager de façon adéquate l’encouragement et la promotion des unités de transformateurs de manioc de petite et moyenne taille et ceci, avec beaucoup plus de vigueur. L’organisation régulière d’ateliers pour renforcer les capacités et l'efficacité des transformateurs est également recommandée. Abstract Most agriculture policies in Nigeria are aimed at integrating the rural poor into market economy. In the last decade, Nigeria witnessed significant private and public injection of capital into the promotion of small-medium scale cassava processing. This study uses a stochastic frontier function and inputs/outputs data to measure technical efficiencies (TE) of 274 small-medium cassava processing firms in Nigeria. Results showed that the cassava processing enterprises had a mean TE of 43 percent, indicating that, a large proportion of output value (57%) is lost due to firm-specific inefficiencies. Cassava processing enterprises in the north-central area of Nigeria recorded a mean TE of 61% (highest), followed by South-east/South-west (42%) and South-south (26%). TE values were below 80% for about 85% percent of the sampled enterprises. Technical efficiencies were influenced by enterprise classification (small-medium, sole proprietorship or family ownership), social factors (interaction with other actors), economic (number of products, clients or orders received) and attendance of training workshop. It is recommended that government and institutions with statutory role to promote agricultural value chains should consider encouraging and promoting small-medium scale cassava processing the more with adequate impetus. Constant training workshops to improve the skills and efficiency of the cassava processors are also recommended

The SLUGGS survey: globular clusters and the dark matter content of early-type galaxies

A strong correlation exists between the total mass of a globular cluster (GC) system and the virial halo mass of the host galaxy. However, the total halo mass in this correlation is a statistical measure conducted on spatial scales that are some 10 times that of a typical GC system. Here we investigate the connection between GC systems and galaxy's dark matter on comparable spatial scales, using dynamical masses measured on a galaxy-by-galaxy basis. Our sample consists of 17 well-studied massive (~10 x 11 M☉) early-type galaxies from the SLUGGS survey. We find the strongest correlation to be that of the blue (metal-poor) GC subpopulation and the dark matter content. This correlation implies that the dark matter mass of a galaxy can be estimated to within a factor of 2 from careful imaging of its GC system. The ratio of the GC system mass to that of the enclosed dark matter is nearly constant. We also find a strong correlation between the fraction of blue GCs and the fraction of enclosed dark matter, so that a typical galaxy with a blue GC fraction of 60 per cent has a dark matter fraction of 86 per cent over similar spatial scales. Both halo growth and removal (via tidal stripping) may play some role in shaping this trend. In the context of the two-phase model for galaxy formation, we find galaxies with the highest fractions of accreted stars to have higher dark matter fractions for a given fraction of blue GCs

Prevalence and factors associated with suicidal ideation amongst college students in the Nelson Mandela Bay Municipality, South Africa

Background: Suicidal behaviour amongst college students constitutes a significant social and public health problem globally. This study determined the prevalence and associated factors of suicidal ideation amongst students of higher education in the Nelson Mandela Bay Municipality (NMBM), South Africa. Methods: In this institution-based cross-sectional study, a multistage cluster sampling of 826 participants, drawn from a college in NMBM, was conducted from January to March 2020. Data were collected with a standardised self-administered questionnaire. Multivariable logistic regression analysis was used to identify the factors associated with suicidal ideation. Results: Participants’ ages ranged from 18 to 24 years, with a mean age of 20.49 years (standard deviation, 1.88 years). The lifetime prevalence of suicidal ideation and plans in the preceding 12 months were 24.5% and 9.6%, respectively. The odds of suicidal ideation were higher in students who experienced bullying (adjusted odds ratio [AOR], 1.89; 95% confidence interval [CI], 1.35–2.65), mental illness (AOR, 1.89; 95% CI, 1.35–2.65), a history of sexual assault (AOR, 2.50; 95% CI, 1.20–5.21) and experience of sexual assault by or to a close family member (AOR, 1.69; 95% CI, 1.01–2.82). Underlying chronic illness was associated with a twofold risk for suicidal ideation in both sexes. Conclusion: About a quarter of the students sampled at the college had experienced suicidal ideation and some had had suicidal plans in the preceding 12 months. Screening for the identified risk factors amongst the student population coupled with prompt interventions would mitigate the risk of suicide in the study population. Keywords: suicidal behaviour; suicidal plans; higher education; students; South Africa

DNA damage response at telomeres boosts the transcription of SARS-CoV-2 receptor ACE2 during aging

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the coronavirus disease 2019 (COVID-19), known to be more common in the elderly, who also show more severe symptoms and are at higher risk of hospitalization and death. Here, we show that the expression of the angiotensin converting enzyme 2 (ACE2), the SARS-CoV-2 cell receptor, increases during aging in mouse and human lungs. ACE2 expression increases upon telomere shortening or dysfunction in both cultured mammalian cells and in vivo in mice. This increase is controlled at the transcriptional level, and Ace2 promoter activity is DNA damage response (DDR)-dependent. Both pharmacological global DDR inhibition of ATM kinase activity and selective telomeric DDR inhibition by the use of antisense oligonucleotides prevent Ace2 upregulation following telomere damage in cultured cells and in mice. We propose that during aging telomere dysfunction due to telomeric shortening or damage triggers DDR activation and this causes the upregulation of ACE2, the SARS-CoV-2 cell receptor, thus contributing to make the elderly more susceptible to the infection

Ultrastructural and functional fate of recycled vesicles in hippocampal synapses

Efficient recycling of synaptic vesicles is thought to be critical for sustained information transfer at central terminals. However, the specific contribution that retrieved vesicles make to future transmission events remains unclear. Here we exploit fluorescence and time-stamped electron microscopy to track the functional and positional fate of vesicles endocytosed after readily releasable pool (RRP) stimulation in rat hippocampal synapses. We show that most vesicles are recovered near the active zone but subsequently take up random positions in the cluster, without preferential bias for future use. These vesicles non-selectively queue, advancing towards the release site with further stimulation in an actin-dependent manner. Nonetheless, the small subset of vesicles retrieved recently in the stimulus train persist nearer the active zone and exhibit more privileged use in the next RRP. Our findings reveal heterogeneity in vesicle fate based on nanoscale position and timing rules, providing new insights into the origins of future pool constitution

Origins of ultradiffuse galaxies in the Coma cluster - II. Constraints from their stellar populations

In this second paper of the series we study, with new Keck/DEIMOS spectra, the stellar populations of seven spectroscopically confirmed ultradiffuse galaxies (UDGs) in the Coma cluster. We find intermediate to old ages (similar to 7Gyr), low metallicities ([Z/H] similar to -0.7 dex) and mostly supersolar abundance patterns ([Mg/Fe] similar to 0.13 dex). These properties are similar to those of low-luminosity (dwarf) galaxies inhabiting the same area in the cluster and are mostly consistent with being the continuity of the stellar mass scaling relations of more massive galaxies. These UDGs' star formation histories imply a relatively recent infall into the Coma cluster, consistent with the theoretical predictions for a dwarf-like origin. However, considering the scatter in the resulting properties and including other UDGs in Coma, together with the results from the velocity phase-space study of the Paper I in this series, a mixed-bag of origins is needed to explain the nature of all UDGs. Our results thus reinforce a scenario in which many UDGs are field dwarfs that become quenched through their later infall onto cluster environments, whereas some UDGs could be genuine primordial galaxies that failed to develop due to an early quenching phase. The unknown proportion of dwarf-like to primordial-like UDGs leaves the enigma of the nature of UDGs still open