2,634 research outputs found
Integrating Local Cultural Knowledge as Formal and Informal Education for Young African Learners: A Ghanaian Case Study
This paper is about schooling, education and socialization in Africa with a focus on the pedagogic and instructional relevance of local cultural resource knowledge such as the teachings of Indigenous proverbs. Using Ghanaian case material, the paper examines how Indigenous cultural knowledges inform the education and socialization of youth and suggest ways for rethinking schooling and education in African contexts. Among the teachings of Indigenous proverbs highlighted are knowings about self and community, development of self-worth and character, importance of social discipline and collective social responsibility. The discussion also addresses the challenges of integrating local cultural knowledges as part of the formal education of young learners.
Cet article cherche à comprendre les processus de scolarité, d‘éducation et de socialisation en Afrique en se concentrant spécialement sur la pédagogie des connaissances culturelles locales telles que l‘enseignement des proverbes autochtones. Cet article examine comment les connaissances culturelles locales informent l‘éducation et les processus de socialisation des jeunes et suggère de ce fait une remise en question de la scolarité et de l‘éducation dans les contextes africains. Parmi les proverbes autochtones enseignés, certains font référence au développement personnel du soi et à la notion de communauté, à l‘amour propre et à la dignité, à l‘importance de la discipline sociale et à la responsabilité collective sociale. En conclusion, cet article discute également des défis auxquels il faut faire face quand il est question d‘intégrer les connaissances culturelles locales dans la formation officielle des jeunes apprenants
Mammalian sugar-binding receptors: known functions and unexplored roles
Mammalian glycan-binding receptors, sometimes known as lectins, interact withglycans, the oligosaccharide portions ofendogenous mammalian glycoproteins and glycolipids as well as sugars on the surfaces of microbes.Thesereceptors guide glycoproteins out of and back into cells, facilitate communication between cells through both adhesion and signaling, and allow the innate immune system to respond quickly to viral, fungal, bacterial,and parasiticpathogens.For many of the roughly one hundred glycan-binding receptors that are known in humans,there aregood descriptions of what types of glycans they bind and how selectivity for these ligands is achievedat the molecular level.In some cases, there is also comprehensive evidencefor the roles thatthe receptors playat the cellular and organismal levels. In addition to highlighting these well-understood paradigms for glycan-binding receptors, this review will suggest where gaps remain in our understandingof the physiological functions that they can serve
Accuracy of at-sea commercial size grading of tiger prawns (Penaeus esculentus and P-semisulcatus) in the Australian northern prawn fishery
The size-frequency distribution of the commercial catch is often used as the basis of fisheries stock assessments (Paul and Morgan, 1987; Gulland and Rosenberg, 1992) because most dynamic processes of populations (growth, survival, recruitment) are reflected in changes in this distribution. The data are generally collected, often at great expense, by sampling the catch at landing sites and markets, or onboard fishing vessels.
Size-frequency distributions of prawns (Penaeus esculentus and P. semisulcatus) can also be obtained from fish processors, who grade landings by size. These data are easier and cheaper to obtain than research samples, but unfortunately they are also considered less accurate and lack spatial information. However, they have been used in stock assessment of prawns in Kuwait (Jones and van Zalinge, 1981) and Malaysia (Simpson and Kong, 1978).
It is often difficult to relate size data obtained from a processor to time and place of capture of the prawns, but this is not the case when the product is packed onboard, as in Australia's northern prawn fishery (NPF).
Trawler operators in the NPF have voluntarily recorded size composition since 1985, when provision for this was made in operators' daily logbooks (between 30% and 45% of the tiger prawn catch reported in the logbooks contain size information). These books are therefore the most comprehensive source of information on the spatial and temporal size distribution of the commercial catch of the NPF. Present assessments of the fishery are based on deterministic growth and deterministic seasonal recruitment patterns (Wang and Die, 1996) and do not use size-structured data. If available, these data would help relax the recruitment and improve current stock assessments of the NPF.
Before the size data recorded in the logbooks can be used, however, the accuracy of size grading at sea needs to the assessed. This paper examines the accuracy of grading tiger prawns, by using data collected from a private firm, A. Raptis and Sons, that operates a large modern processing factory that regularly assesses the onboard grading of product purchased from NPF trawler operators.
Although the work presented here relates specifically to the NPF, the practice of onboard size grading is widespread in other fisheries around the world. Therefore our methods have potential application to other fisheries
Lidocaine effects on acetylcholine-elicited currents from mouse superior cervical ganglion neurons
Lidocaine is a commonly used local anaesthetic that, besides blocking voltage-dependent Na+ channels, has multiple inhibitory effects on muscle-type nicotinic acetylcholine (ACh) receptors (nAChRs). In the present study, we have investigated the effects of lidocaine on ACh-elicited currents (IAChs) from cultured mouse superior cervical ganglion (SCG) neurons, which mainly express heteromeric α3β4 nAChRs. Neurons were voltage-clamped by using the perforated-patch method and IAChs were elicited by fast application of ACh (100-300 μM), either alone or in presence of lidocaine at different concentrations. IAChs were reversibly blocked by lidocaine in a concentration-dependent way (IC50 = 41 μM; nH close to 1) and the inhibition was, at least partially, voltage-dependent, indicating an open-channel blockade. Besides, lidocaine blocked resting (closed) nAChRs, as evidenced by the increased inhibition caused by a 12 s lidocaine application just before its co-application with the agonist, and also enhanced IAChs desensitisation, at concentrations close to the IC50. These results indicate that lidocaine has diverse inhibitory actions on neuronal heteromeric nAChRs resembling those previously reported for Torpedo (muscle-type) nAChRs ( Alberola-Die et al., 2011). The similarity of lidocaine actions on different subtypes of heteromeric nAChRs differs with the specific effects of other compounds, restricted to particular subtypes of nAChRs.This work was supported by the following MICINN (Spanish government) grants: CONSOLIDER-INGENIO 2010 (CSD2008-00005), BFU2011-25371 and BFU2012-31359
El Paleolítico Medio en el territorio valenciano y la variabilidad tecno-económica de la Cova del Bolomor
En el presente artículo se exponen las principales características de las industrias líticas del Paleolítico Medio en el territorio valenciano. Se hace especial hincapié en la variabilidad tecno-económica observada en la secuencia estratigráfica de la Cova del Bolomor. Con dicho análisis se pretende contribuir al establecimiento de los rasgos evolutivos de las industrias asociadas a los grupos de neandertales. En este sentido, el estudio pone de manifiesto que en estas sociedades se produjo, en los momentos finales, cierto progreso tecnológico, en un contexto arqueológico en el que es difícil precisar si hubo, o no, influencia externa o aculturación por parte de las poblaciones de cromañones en el territorio valenciano.En el present article s'exposen les principals característiques de les indústries lítiques del Paleolític Mitjà en el territori valencià. Es posa especial atenció a la variabilitat tecno-econòmica observada en la seqüència estratigràfica de la Cova del Bolomor. Amb aquesta anàlisi es pretén contribuir a l'establiment dels trets evolutius de les indústries associades als grups de neandertals. En aquest sentit, l'estudi posa de manifest que en aquestes societats es va produir, en els moments finals, un cert progrés tecnològic, en un context arqueològic en el qual és difícil precisar si va haver-hi, o no, influència externa o aculturació per part de les poblacions de cromanyons en el territori valencià.Dans l'article ci-dessous, s'exposent les principales caractéristiques des industries lithiques du Paléolithique Moyen dans le territoire valencien. On veut mettre en relief la variabilité techno-économique observée dans la séquence stratigraphique de la Cova del Bolomor. Avec cette analyse, on cherche à établir les traits évolutifs des industries associées aux groupes néandertaliens. Dans ce sens, l'étude met en relief que ces sociétés ont probablement connu, dans un dernier temps, un certain progrès technologique, dans un contexte archéologique où il est difficile de préciser s'il y a eu ou pas une influence externe ou une acculturation venue des populations cromagnones dans la région de Valence.In this paper main characteristics of the Middle Palaeolithic lithic industries from the territory of Valencia are presented. Particular attention is paid to the techno-economical variability of the archaeological record in Cova del Bolomor. This study aims to discuss the evolutionary features of Neanderthal industries; our analysis shows that there was some technological progress at the end of the Middle Palaeolithic, in an archaeological context in which it is uncertain whether or not there was external influence or acculturation from Cro-Magnon populations in the valencian territory
RNA-seq combined with a bulked-segregant analysis identifies candidate genes for the waxy coating on blueberry fruit
The most significant difference between blueberries with a light blue fruit color and black fruit color is the visible layer of an epicuticular waxy coating. This layer functions in disease defense and prevention of water loss. In this study, we constructed a northern-adapted rabbiteye hybrid breeding population, ‘Nocturne’ x T 300, which segregated for fruit color (light blue versus black). We screened this population and selected plants of each extreme phenotype, waxy- coated plants with light blue colored fruit versus non-waxy plants with black colored fruit, then isolated RNA from fruit tissue of each bulk, respectively. We sequenced the transcriptome of each bulk using RNA-seq, which resulted in a total of 167,093,354 reads for both libraries combined. We de novo assembled this data set into 171,678 contigs and used the assembled transcriptome as a reference for differential expression analysis using EdgeR. A total of 515 differentially expressed genes were identified with at least a four-fold difference in expression, and efforts were made to functionally annotate them using publicly available databases. From these, one excellent candidate ‘waxy’ gene has emerged, which we are investigating further
Characterization and Analysis of Anthocyanin-Related Genes in Wild-Type Blueberry and the Pink-Fruited Mutant Cultivar ‘Pink Lemonade’: New Insights into Anthocyanin Biosynthesis
Blueberries are one of the richest sources of antioxidants, such as anthocyanins, among fruits and vegetables. Anthocyanin mutants, like the pink-fruited cultivar ‘Pink Lemonade’, are valuable resources for investigating anthocyanin biosynthesis in blueberries. In this study, we examined expression of flavonoid pathway genes during fruit development in wild-type, blue-fruited blueberries using quantitative real-time PCR. Expression was also compared between wild-type and the pink-fruited ‘Pink Lemonade’. This revealed significantly lower expression in ‘Pink Lemonade’ than in wild-type of nearly all the structural genes examined suggesting that a transcriptional regulator of the pathway was affected. Hence, we compared expression of three known regulatory genes and found that the gene encoding the transcription factor MYB1 was expressed at a significantly lower level in ‘Pink Lemonade’ than in the wild-type. To validate the capacity of this MYB1 to regulate the transcription of anthocyanin genes in blueberries, a transient expression assay was conducted. Results indicated MYB1 overexpression enhanced anthocyanin production. Comparative sequence analysis between wild-type and mutant MYB1 variants found differences in highly conserved features suggesting a mechanistic explanation for the mutant phenotype. Collectively, the results presented here contribute to a better understanding of mechanisms regulating anthocyanin biosynthesis in Vaccinium
An evaluation of management strategies for Atlantic tuna stocks
International agreements for the International Commission for the Conservation of Atlantic Tunas (ICCAT) convention area imply that Atlantic tuna stocks should be managed by strategies based on maximum sustainable yield (MSY); however, there is concern whether this will actually ensure sustainability with sufficiently high probability consistent with the principals of the precautionary approach. Therefore, the performance of MSY management strategies based on current assessment procedures was evaluated using a computer simulation framework. The framework includes the data collection, assessment, prediction, and management processes, as well as the implementation of management regulations. It therefore provides an integrated way to evaluate the relative importance of and the interactions between each component of the system with regard to the overall success of the management strategy. The study elucidates guidelines about assessment and management that are general enough to be applied to all tunas in the Atlantic Ocean. It does so by comparing different hypotheses about management and assessment for three stocks (North Atlantic albacore, Atlantic bigeye and East Atlantic skipjack), which are representative of the variety encountered (i.e. from data rich to poor and tropical to temperate waters) in ICCAT stocks. Management performance was especially sensitive to the carrying capacity of the stock. The type of proxy used for MSY was more important to the success of the procedure than the frequency of assessment or the number of indices used in the assessment. Whilst the procedure was successful at achieving the management objectives for albacore, it was only partially successful for bigeye and was too conservative for skipjack.No disponibl
Application de la méthode LSPIV pour la mesure de champs de vitesse et de débits de crue sur modèle réduit et en rivière
International audienceLSPIV technique enables the measurement of surface flow velocities using image sequence analysis. EDF and Irstea partnership made possible the development of Fudaa‑LSPIV freeware by DeltaCAD Company. Two software applications at flume and field scales are detailed: (i) bed shear stresses were calculated owing to LSPIV velocities, water depth and bathymetry for a physical model of the Old Rhine; (ii) the software was used to optimize the calculation parameters of LSPIV flood discharge measurement stations in Mediterranean rivers.La technique LSPIV (Large Scale Particle Image Velocimetry) permet de mesurer les vitesses de surface d'un écoulement par analyse de séquence d'images. Pour faciliter l'application opérationnelle de la méthode, un logiciel, Fudaa-LSPIV, a été développé par la société DeltaCAD dans le cadre d'une collaboration entre EDF et Irstea. Deux applications en laboratoire et en rivière sont présentées : (i) couplée avec des mesures de hauteur d'eau et de bathymétries, la LSPIV a permis d'estimer des paramètres de Shields sur le modèle physique à fond mobile du Vieux-Rhin ; (ii) le logiciel a été utilisé pour procéder à des analyses de sensibilité pour paramétrer ainsi au mieux les stations LSPIV de mesure de débit en crue de rivières cévenoles
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