Sample preservation and plant sex prediction in white guinea yam (Dioscorea rotundata Poir.)

Open Access Article; Published online: 11 Jul 2020Introduction: Yam (Dioscorea spp.) is an economically important staple food in tropical regions, especially for people in West Africa. Understanding of the flowering behavior of the crop to determine potential manipulation available to accomplish crop improvement at early stage remain key challenge in the yam breeding. The methods that reliably yield quality DNA and distinguishing sex type at the early stage of growth have been a challenge in yam genetics and breeding studies. This study assessed the effect of sample preservation methods on DNA quantity and quality during extraction and potential of DNA marker to diagnose plant sex at the early seedling stage in white Guinea yam. Materials and Methods: Five sample preservation methods were assessed for quality DNA extraction during field leaf tissue collection, namely liquid nitrogen, dry ice, silica gel, 95% ethanol, and oven drying. The predicted sex at the seedling stage using the molecular marker was further validated with the visual score for the sex phenotype at the flowering stage. Results: According to the findings of the present study, the DNA extracted from leaf samples preserved in liquid nitrogen, silica gel, dry ice, and oven drying methods were higher in molecular weights than samples stored in ethanol solution. Yam plant sex diagnosis with the DNA marker (sp16) identified a higher proportion of ZW genotypes (female or monoecious phenotypes) than the ZZ genotypes (male phenotypes) in the studied materials with 74% prediction accuracy. Conclusions: The results from this study provided valuable insights on suitable sample preservation methods for quality DNA extraction and the potential of DNA marker sp16 to predict sex in white Guinea yam

Pattern of cervical dilatation among parturients in Ilorin, Nigeria

Objective : To evaluate the pattern of cervical dilatation in live singleton pregnancies with spontaneous onset of labor and to compare any differences among nulliparas (P ara 0) and multiparas (Para 651). Material and Methods : Descriptive statistics are presented for 238 consecutive labor patients with spontaneous onset, 6537 weeks gestation, live singleton pregnancy and who had spontaneous vertex delivery at the University of Ilorin Teaching Hospital, Nigeria, from May 2004 to June 2004. Pre-labor rupture of membrane and referred cases were excluded. Results : The mean cervical dilatation on presentation and duration of labor before presentation in labor ward among nulliparas were 5.40 cm and 6.66 hours; and among multiparas, 6.45 cm and 5.15 hours, respectively, the overall mean being 6.12 cm and 5.63 hours, respectively. The average time spent to achieve full cervical dilatation from time of arrival in labor ward was longer in nulliparas (4.80 hours) than in multiparas (3.60 hours) (t test not significant; P> 0.05). Overall mean total length of first stage of labor was 9.36 hours, while the total length of first stage of labor was 11.03 hours and 8.53 hours for nulliparas and multiparas, respectively (difference is significant; t test P< 0.05). Significant negative correlation existed between parity and total length of first stage of labor. Mean cervical dilatation rate in labor ward (active phase) was higher in multiparas (1.83 cm/h) than in nulliparas (1.76 cm/h), but the difference was not significant (t test P> 0.05). No significant correlation existed between rate of cervical dilatation and maternal age, gestational age and fetal size. Conclusion : It is evident from this study that higher the parity the shorter the length of first stage of labor; however, significant difference existed only in the first half of first stage of labor between nulliparas and multiparas. Mean rate of cervical dilatation was greater than the WHO-specified and Philpott\u2032s lower limit of 1 cm/h in active phase of labor.Objectif: pour \ue9valuer la motif de dilatation du col ut\ue9rin dans les grossesses singleton live avec spontan\ue9e apparition du travail et de comparer les diff\ue9rences entre les nulliparas (para 0) et multiparas (para 651). Methodes: Statistiques descriptives sont pr\ue9sent\ue9es pour 238 cas du travail cons\ue9cutifs avec apparition spontan\ue9e, 6537weeks gestation, vivre singleton grossesse et avait vertex spontan\ue9e livraison \ue0 l\u2019h\uf4pital d\u2019enseignement universitaire de Ilorin, Nig\ue9ria, de mai 2004 \ue0 juin 2004. Rupture prelabour de la membrane et cas mentionn\ue9s ont \ue9t\ue9 exclus. R\ue9sultats: le signifi e la dilatation du col ut\ue9rin sur pr\ue9sentation et la dur\ue9e du travail avant pr\ue9sentation dans le quartier du travail chez les nulliparas a \ue9t\ue9 cm 5.40 et 6.66hrs et cm 6.45 et 5.15hrs chez multiparas, alors que moyenne globale \ue9tait cm 6.12 et 5.63hrs respectivement. Le temps moyen pass\ue9 pour atteindre la dilatation compl\ue8te du col de moment de l\u2019arriv\ue9e dans le quartier du travail \ue9tait plus longtemps dans nulliparas (4.80hrs) que dans multiparas (3.60hrs), t tester non signifi cative p > 0,05. Dans l\u2019ensemble signifi e longueur totale de premi\ue8re \ue9tape du travail a \ue9t\ue9 9.36hrs, tandis que 11.03hrs et 8.53hrs pour nulliparas et multiparas respectivement (diff\ue9rence est importante, t tester p > 0,05).Corr\ue9lation n\ue9gative signifi cative existait entre parit\ue9 et la longueur totale de premi\ue8re \ue9tape du travail. Signifi e que le taux de dilatation du col ut\ue9rin dans quartier du travail (active phase) \ue9tait plus \ue9lev\ue9 dans multiparas (1,83 cm/h) que dans nulliparas (1.76 cm/h), mais la diff\ue9rence n\u2019est pas signifi cative, t tester p > 0,05. Aucune corr\ue9lation signifi cative n\u2019existait entre les taux de dilatation du col ut\ue9rin et \ue2ge maternel, \ue2ge gestationnel et taille du foetus. Conclusion: il ressort de cette \ue9tude que plue la parit\ue9, la plus courte de la longueur de premi\ue8re \ue9tape de travail, toutefois diff\ue9rence signifi cative existait uniquement dans le premier la moiti\ue9 de premi\ue8re \ue9tape du travail entre nulliparas et multiparas. Taux moyen de dilatation du col ut\ue9rin a \ue9t\ue9 sup\ue9rieure \ue0 WHO et Philpott de la plus faible limite de 1 cm/hr. phase active de travail

Application of predictive breeding in yam improvement for west Africa

Open Access Journa

Mobile phones in the diffusion of knowledge and persistence in inclusive human development in Sub-Saharan Africa

The success of inclusive development strategies in the post-2015 sustainable development agenda depends substantially on the adoption of common inclusive development policies among nations. Building on the relevance of a knowledge economy in the post-2015 development agenda, this study models the feasibility of common policies for inclusive human development in Sub-Saharan Africa (SSA). More specifically, we investigate the complementary role of knowledge diffusion in the inclusive benefits of mobile phone penetration in SSA from 2000 to 2012 by employing the Generalised Method of Moments. Knowledge diffusion variables include educational quality, innovation and Internet penetration. The main finding is that inclusive human development is persistently conditional on mobile phones in knowledge diffusion. Moreover, countries with low levels of inclusive human development are catching-up their counterparts with higher development. Policy implications are discussed with particular emphasis on how to leverage common knowledge economy initiatives for inclusive developmen

Patient characteristics associated with COVID-19 positivity and fatality in Nigeria: retrospective cohort study

Objective: Despite the increasing disease burden, there is a dearth of context-specific evidence on the risk factors for COVID-19 positivity and subsequent death in Nigeria. Thus, the study objective was to identify context-specific factors associated with testing positive for COVID-19 and fatality in Nigeria. Design Retrospective cohort study. Setting: COVID-19 surveillance and laboratory centres in 36 states and the Federal Capital Territory reporting data to the Nigeria Centre for Disease Control. Participants: Individuals who were investigated for SARSCoV-2 using real-time PCR testing during the study period 27 February–8 June 2020. Methods: COVID-19 positivity and subsequent mortality. Multivariable logistic regression analyses were performed to identify factors independently associated with both outcome variables, and findings are presented as adjusted ORs (aORs) and 95% CIs. Results: A total of 36 496 patients were tested for COVID-19, with 10 517 confirmed cases. Of 3215 confirmed cases with available clinical outcomes, 295 died. Factors independently associated with COVID-19 positivity were older age (p value for trend<0.0001), male sex (aOR 1.11, 95%CI 1.04 to 1.18) and the following presenting symptoms: cough (aOR 1.23, 95% CI 1.13 to 1.32), fever (aOR 1.45, 95% CI 1.45 to 1.71), loss of smell (aOR 7.78, 95% CI 5.19 to 11.66) and loss of taste (aOR 2.50, 95% CI 1.60 to 3.90). An increased risk of mortality following COVID-19 was observed in those aged ≥51 years, patients in farming occupation (aOR 7.56, 95% CI 1.70 to 33.53) and those presenting with cough (aOR 2.06, 95% CI 1.41 to 3.01), breathing difficulties (aOR 5.68, 95% CI 3.77 to 8.58) and vomiting (aOR 2.54, 95% CI 1.33 to 4.84). Conclusion: The significant risk factors associated with COVID-19 positivity and subsequent mortality in the Nigerian population are similar to those reported in studies from other countries and should guide clinical decisions for COVID-19 testing and specialist care referrals

Structural mechanism for signal transduction in RXR nuclear receptor heterodimers

A subset of nuclear receptors (NRs) function as obligate heterodimers with retinoid X receptor (RXR), allowing integration of ligand-dependent signals across the dimer interface via an unknown structural mechanism. Using nuclear magnetic resonance (NMR) spectroscopy, x-ray crystallography and hydrogen/deuterium exchange (HDX) mass spectrometry, here we show an allosteric mechanism through which RXR co-operates with a permissive dimer partner, peroxisome proliferator-activated receptor (PPAR)-γ, while rendered generally unresponsive by a non-permissive dimer partner, thyroid hormone (TR) receptor. Amino acid residues that mediate this allosteric mechanism comprise an evolutionarily conserved network discovered by statistical coupling analysis (SCA). This SCA network acts as a signalling rheostat to integrate signals between dimer partners, ligands and coregulator-binding sites, thereby affecting signal transmission in RXR heterodimers. These findings define rules guiding how NRs integrate two ligand-dependent signalling pathways into RXR heterodimer-specific responses.Douglas J. Kojetin, Edna Matta-Camacho, Travis S. Hughes, Sathish Srinivasan, Jerome C. Nwachukwu, Valerie Cavett, Jason Nowak, Michael J. Chalmers, David P. Marciano, Theodore M. Kamenecka, Andrew I. Shulman, w, Mark Rance, Patrick R. Griffin, John B. Bruning, Kendall W. Nettle