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On the estimation of female births missing due to prenatal sex selection
No full textThis research note is prompted by a paper by Kashyap (Is prenatal sex selection associated with lower female child mortality? Population Studies 73(1): 57-78). Kashyap's paper, which provides 40 original estimates of missing female births, relies on an alternative definition of missing female births, leading to estimates of about half the magnitude of other estimates. There appears, therefore, a real need to take stock of the concept of missing female births widely used by statisticians around the world for assessing the demographic consequences of prenatal sex selection. This research note starts with a brief review of the history of the concept and the difference between Amartya Sen's original method and the alternative method found elsewhere to compute missing female births. We then put forward three different arguments (deterministic and probabilistic approaches, and consistency analysis) in support of the original computation procedure based on the number of observed male births and the expected sex ratio at birth
Research and development challenges in scaling innovation : a case study of the LEAP-Agri RAMSES II project
No full textA widely held assumption is that intensifying agroforestry will lead to sustainable increases in production, societal resilience and food security, urgently needed in the current context of changes in markets, climate and demography. Current thinking assumes that to achieve sustainable innovation a participatory approach with public, civil and private stakeholders is necessary, combined with a systemic, trans-disciplinary approach, rather than a technical approach. This study presents a case of applying the Theory of Change (ToC) concept to test this assumption. The ToC was designed to articulate the process of scaling of action-research findings, and to adapt the research to the context of complex agroforestry systems at plot, household, farm, village and landscape levels. This allowed to develop an intervention logic that unpacks what sustainability means for farmers and other local stakeholders in four West African agroforestry systems. The conceptual approach created an awareness of potential impacts of scaling initiatives based on a ToC with pathways to impact combined with monitoring the effects of the research & development project on a variety of ecological, agronomic and economic performance indicators. A number of constraints and paradoxes that are linked to current research and development short term funding are also discussed
Diversity, phylogeny, and historical biogeography of large-eye seabreams (Teleostei : Lethrinidae)
No full textThe large-eye seabreams or Monotaxinae is one of two subfamilies in the Lethrinidae, a family of perch-like coral reef fishes. Despite its widespread occurrence and its commercial interest in the tropical Indo-West Pacific (IWP), this subfamily has traditionally been considered a taxonomically difficult group. Based on 268 samples collected from all 15 known large-eye seabream species throughout their distribution ranges, we investigated the taxonomic diversity and phylogenetic relationships in the subfamily. From the results of multiple analyses on four gene markers, we confirmed the monophyly of all four genera in the subfamily (Gnathodentex, Gymnocranius, Monotaxis and Wattsia). We confirmed the occurrence of two species in the genus Monotaxis. We reported 15 delimited species within the most speciose genus Gymnocranius, four of which are potentially new species. The time-calibrated phylogenetic reconstruction enabled us to clarify the evolutionary history of the large-eye seabreams and to infer past patterns of species distribution. The most recent common ancestor to the Monotaxinae likely occurred in the central IWP ca. 32 million years ago. A burst of species diversification likely took place during the Mid-to Late Miocene, coinciding with tectonic change in the central IWP region. This gave rise to most extant lineages in Gymnocranius. The observed geographic distribution patterns in the subfamily most likely point to the central IWP as the area of origin and diversification. This was followed by multiple events of centrifugal range expansion towards either the Indian Ocean or the western Pacific Ocean, or both. Our results thus provide new support for S. Ekman's center-of-origin hypothesis
Diet of albacore Thunnus alalunga from the waters of Mauritius (western Indian Ocean) inferred from stomach contents and fatty acid analysis
No full textThe diet of albacore Thunnus alalunga from their spawning ground in the waters of Mauritius was investigated. The stomach contents of 249 albacore individuals, caught by industrial longliners and artisanal fishers, was analysed, and the dominant prey taxa were selected for lipid and fatty acid (FA) analysis. The FA profiles of prey were compared with those of liver tissue of spawning-capable and post-spawning female albacore, using multivariate analysis. Whereas stomach content analysis identified cephalopods and crustaceans as the dominant prey items in number, FA-profile analysis identified crustaceans and fishes as the most-frequently consumed prey of post-spawning female albacore. In contrast, the FA profiles of spawning-capable albacore and those of prey showed very low similarity. Analysis of the prey suggests that although cephalopods, crustaceans and fishes could all provide albacore with the required lipids and FAs, cephalopod prey seem to be less desirable owing to their lower energy content (i.e. low in total lipid, triacylglycerol, 16:0, 18:0 and 18:1 omega 9). Instead, the most beneficial food appeared to be locally available fishes, which are more energy-rich and have a higher docosahexaenoic acid/ eicosapentaenoic acid ratio. These results provide new information on the trophic ecology of albacore, promote our understanding of the importance of prey type for successful reproduction of albacore, and highlight the advantages of FA profiling to study diet
Video as a public health knowledge transfer tool in Burkina Faso : a mixed evaluation comparing three narrative genres
No full textBackground The dengue virus is endemic in many low- and middle-income countries. In Burkina Faso, the proportion of fevers that could be due to dengue is growing. In 2013, a dengue epidemic spread there, followed by other seasonal outbreaks. Dengue is often confused with malaria, and health workers are not trained to distinguish between them. Three training videos using different narrative genres were tested with nursing students from two institutions in Ouagadougou: journalistic, dramatic and animated video. The study aimed to determine if video is an effective knowledge transfer tool, if narrative genre plays a role in knowledge acquisition, and which narrative elements are the most appreciated. Methodology A mixed method research design was used. The relative effectiveness of the videos was verified through a quasi-experimental quantitative component with a comparison group and post-test measurements. A qualitative component identified participants' perceptions regarding the three videos. Data were drawn from a knowledge test (n = 482), three focus groups with health professionals' students (n = 46), and individual interviews with health professionals (n = 10). Descriptive statistics and single-factor variance analysis were produced. A thematic analysis was used to analyse qualitative data. Principal findings Results showed that all three videos led to significant rates of knowledge improvement when compared with the comparison group (p <0.05): 12.31% for the journalistic video, 20.58% for the dramatic video, and 18.91% for the animated video. The dramatic and animated videos produced a significantly higher increase in knowledge than did the journalistic video (with respectively 8.27% (p = 0.003) and 6.59% (p = 0.029) and can be considered equivalent with a difference of 1.68% (p = 0.895). Thematic analysis also revealed that these two videos were considered to be better knowledge transfer tools. Four key aspects are important to consider for a video to be effective: 1) transmitting information in a narrative form, 2) choosing good communicators, 3) creating a visual instrument that reinforces the message and 4) adapting the message to the local context. Conclusions Video has proven to be an effective and appreciated knowledge transfer and training tool for health professionals, but the narrative genre of the videos can influence knowledge acquisition. The production of other videos should be considered for training or updating health professionals and their narrative genre taken into consideration. The actual context of constant circulation of new diseases, such as COVID-19, reaffirms the need to train health professionals. Author summary The dengue virus is endemic in many low- and middle-income countries, including Burkina Faso. Since 2013, successive seasonal epidemics in the country have resulted in many deaths that could have been prevented if health professionals had been better trained. Although recent studies have reported the presence of the virus in Burkina Faso's capital, Ouagadougou, several cases of dengue fever have been reported that were misdiagnosed and treated incorrectly. Video is a promising knowledge transfer (KT) tool to address the training needs of health workers. The ease with which a video can be shared, and its playful nature makes it a particularly attractive tool for reaching and training them and transforming their practices, especially, given their busy schedules. The study addresses the use of video as a KT strategy in relation to the narrative genre, i.e., how information is presented. It contributes to the advancement of knowledge on what motivates the use of video as a KT tool and practice changes in working contexts where professionals need to know how to respond, quickly and appropriately, to health problems such as dengue and other emerging pathologies in Africa
Structure of the Ecuadorian forearc from the joint inversion of receiver functions and ambient noise surface waves
No full textThe Ecuadorian forearc is a complex region of accreted terranes with a history of large megathrust earthquakes. Most recently, a M-w 7.8 megathrust earthquake ruptured the plate boundary offshore of Pedernales, Ecuador on 16 April 2016. Following this event, an international collaboration arranged by the Instituto Geofisico at the Escuela Politecnica Nacional mobilized a rapid deployment of 65 seismic instruments along the Ecuadorian forearc. We combine this new seismic data set with 14 permanent stations from the Ecuadorian national network to better understand how variations in crustal structure relate to regional seismic hazards along the margin. Here, we present receiver function adaptive common conversion point stacks and a shear velocity model derived from the joint inversion of receiver functions and surface wave dispersion data obtained through ambient noise cross-correlations for the upper 50 km of the forearc. Beneath the forearc crust, we observe an eastward dipping slow velocity anomaly we interpret as subducting oceanic crust, which shallows near the projected centre of the subducting Carnegie Ridge. We also observe a strong shallow positive conversion in the Ecuadorian forearc near the Borbon Basin indicating a major discontinuity at a depth of similar to 7 km. This conversion is not ubiquitous and may be the top of the accreted terranes. We also observe significant north-south changes in shear wave velocity. The velocity changes indicate variations in the accreted terranes and may indicate an increased amount of hydration beneath the Manabi Basin. This change in structure also correlates geographically with the southern rupture limit of multiple high magnitude megathrust earthquakes. The earthquake record along the Ecuadorian trench shows that no event with a M-w >7.4 has ruptured south of similar to 0.5 degrees S in southern Ecuador or northern Peru. Our observations, along with previous studies, suggest that variations in the forearc crustal structure and subducting oceanic crust may influance the occurrence and spatial distribution of high magnitude seismicity in the region
Farnesyl glycosides and one new triterpenoid saponin from the roots of Lecaniodiscus cupanioides Planch. ex Benth
No full textChemical investigation of the methanol extract of the roots of Lecaniodiscus cupanioides led to the isolation and characterisation of three new sesquiterpene glycosides, named cupanioidesosides A (1), B (2) and C (3), together with one new triterpenoid saponin named lecanioside A (4), Their structures were established by extensive analysis of spectroscopic methods including 1D and 2D NMR techniques (COSY, NOESY, TOCSY, HSQC, and HMBC) and HRESIMS. The four new compounds were evaluated for their antiproliferative activity against the Caco-2 cell line (human epithelial cell line). None of the isolated compounds showed positive activity in our assay. Our findings represent a valuable contribution to the chemotaxonomy Lecaniodiscus genus of the subfamily of Sapindoideae of Sapindaceae family, known to be a rich source of farnesol glycosides
High levels of genetic diversity within nilo-saharan populations : implications for human adaptation
No full textAfrica contains more human genetic variation than any other continent, but the majority of the population-scale analyses of the African peoples have focused on just two of the four major linguistic groups, the Niger-Congo and Afro-Asiatic, leaving the Nilo-Saharan and Khoisan populations under-represented. In order to assess genetic variation and signatures of selection within a Nilo-Saharan population and between the Nilo-Saharan and Niger-Congo and Afro-Asiatic, we sequenced 50 genomes from the Nilo-Saharan Lugbara population of North-West Uganda and 250 genomes from 6 previously unsequenced Niger-Congo populations. We compared these data to data from a further 16 Eurasian and African populations including the Gumuz, another putative Nilo-Saharan population from Ethiopia. Of the 21 million variants identified in the Nilo-Saharan population, 3.57 million (17%) were not represented in dbSNP and included predicted non-synonymous mutations with possible phenotypic effects. We found greater genetic differentiation between the Nilo-Saharan Lugbara and Gumuz populations than between any two Afro-Asiatic or Niger-Congo populations. F3 tests showed that Gumuz contributed a genetic component to most Niger-Congo B populations whereas Lugabara did not. We scanned the genomes of the Lugbara for evidence of selective sweeps. We found selective sweeps at four loci (SLC24A5, SNX13, TYRP1, and UVRAG) associated with skin pigmentation, three of which already have been reported to be under selection. These selective sweeps point toward adaptations to the intense UV radiation of the Sahel
Seasonal and tidal variability of the hydrology and suspended particulate matter in the Van Uc estuary, Red River, Vietnam
No full textThis study explores the seasonal and tidal changes in flow and suspended matter dynamics in the tropical and macrotidal Van Uc River estuary (North Vietnam) and aims at understanding, among others, the sediment delivery to the ocean and the processes behind the estuarine siltation. Four campaigns took place during the contrasting high flow and low flow seasons, for each during neap and spring tides. Water and suspended matter fluxes, salinity, turbidity and particle size distribution (PSD) were measured for 24 h at three cross sections along the estuary. During the high-flow season, the estuary was mixed, with seaward sediment flux during neap tide and ephemeral up-estuary sediment flux at spring tides due to tidal distortion. During the low-flow season, the system transitioned from partially mixed to highly stratified with salty waters intrusions, salt wedge presence and up-estuary sediment flux varying with the tidal regime. The highest up-estuary sediment flow occurred during low-flow at spring tides and represented 2/3 of the outflow. The lower river discharge, the higher PSD variation. The increasing proportion of microflocs with increasing salinity as compared to primary particles and flocculi was observed at both seasons. Higher tidal variations of PSD at spring tides indicate the strong effect of turbulent shear. These findings also provide a new benchmark for hydro-sedimentary model calibration/validation
Water quality for young children in Cambodia : high contamination at collection and consumption level
No full textUnsafe drinking water is a leading cause of child morbidity, especially among young children in low-income settings. Safe water consumption requires high-quality water available at its source and at point of use. We examined the quality of drinking water at point of collection and point of use in 796 households in three provinces, in Cambodia. Microbiological testing for coliform andEscherichia colicontamination was conducted for samples collected. Bivariable analysis and multivariable logistic regression were used to examine associations between various factors and the deterioration in water quality (increase in the risk according coliform orE. coliconcentration) between point of collection and point of use. Contamination with both coliforms andE. coliwas higher at point of use than at point of collection, with contamination at point of collection to account for 76.6% (coliforms) and 46.3% (E. coli). Results suggest that child drinking water represents a considerable pathway for the ingestion of pathogens, in Cambodia. Area of residence, seasonality, type of water source, and water chlorination were associated with coliform concentration between the point of collection and point of use, whereas only seasonality was associated withE. colicontamination (OR = 1.46; 95% CI [1.05, 2.02]). Children living in rural settings were two times more likely to drink water with a deteriorating coliform concentration between the two-time points than children living in urban settings (OR = 2.00; 95% CI [1.22, 3.30]). The increase in coliform andE. coliconcentrations between point of collection and point of use indicates that water contamination mostly occurs within the household. Strengthening national legislation on water quality standards and promoting safe water management at the household are needed