37 research outputs found

    Drainage And Sedimentary Response Of The Northern Andes And The Pebas System To Miocene Strike-slip Tectonics: A Source To Sink Study Of The Magdalena Basin

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    Miocene strike-slip tectonics was responsible for creating and closing short-lived (ca. 6 Ma) passages and the emergence of isolated topography in the Northern Andes. These geological events likely influenced the migration and/or isolation of biological populations. To better understand the paleogeography of the Miocene hinterland and foreland regions in the Northern Andes, we conducted a source-to-sink approach in the Magdalena Basin. This basin is located between the Central and Eastern Cordilleras of Colombia and contains an ample Miocene record, which includes Lower Miocene fine-grained strata and Middle Miocene to Pliocene coarsening-up strata. Our study presents a new data set that includes detrital U–Pb zircon ages (15 samples), sandstone petrography (45 samples) and low-temperature thermochronology from the Southern Central Cordillera (19 dates); which together with previously published data were used to construct a paleogeographical model of the Miocene hinterland and foreland regions in the Northern Andes. The evolution of the Magdalena Basin during the Miocene was characterized by playa and permanent lake systems at ca. 17.5 Ma, which may be related to a marine incursion into NW South America and western Amazonia. The appearance of Eocene to Miocene volcanic sources in the Honda Group after ca. 16 Ma suggests the development of fluvial passages, which connected the Pacific with the western Amazonia and Caribbean regions. These passages were synchronous with a time of Miocene exhumation and topographic growth (ca. 16 to 10 Ma) in the Central Cordillera and the transition from lacustrine to fluvial deposition in the Magdalena Basin. Middle to Late Miocene strike-slip deformation promoted by oblique plate convergence and the oblique collision of the Panamá-Chocó Block likely explains the synchronous along-strike fragmentation and exhumation in the Central Cordillera

    Causal attribution of mental illness in south-eastern Nigeria

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    Background: Understanding of mental illness in sub-Saharan Africa has remained under-researched in spite of the high and increasing neuropsychiatric burden of disease in the region. Aims: This study investigated the causal beliefs that the Igbo people of south-eastern Nigeria hold about schizophrenia, with a view to establishing the extent to which the population makes psychosocial, biological and supernatural attributions. Method: Multi-stage sampling was used to select participants (N = 200) to which questionnaires were administered. Results: Mean comparison of the three causal models revealed a significant endorsement of supernatural causation. Logistic regressions revealed significant contributions of old age and female gender to supernatural attribution; old age, high education and Catholic religious denomination to psychosocial attributions; and high education to biological attributions. Conclusions: It is hoped that the findings would enlighten, augment literature and enhance mental health care service delivery

    Supressão de plantas daninhas por leguminosas anuais em sistema agroecológico na Pré-Amazônia.

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    Este trabalho teve por objetivos identificar e avaliar a agressividade potencial das plantas daninhas em um agrossistema com leguminosas herbáceas anuais como cobertura de solo. Foram plantadas, nas ruas de um sistema de aléias de sombreiro ( Clitoria fairchildiana) e no final do período agrícola, as leguminosas mucuna-preta, feijão-guandu, feijão-de-porco e calopogônio, em sistema de blocos ao acaso com cinco repetições. Para estudo da dinâmica da composição florística, avaliaram-se a freqüência, densidade, dominância, similaridade, diversidade de espécies e biomassa das plantas daninhas. Foram identificadas 42 espécies de plantas espontâneas, das quais as mais freqüentes e de maior densidade e dominância foram Leptochoa virgata, Panicumlaxum e Sidasp. Não foram detectadas diferenças significativas para densidade, número de espécies, diversidade e biomassa entre as plantas daninhas emergidas nos quatro tratamentos com leguminosas; nem destas em relação ao controle

    Avaliação fitossociológica da comunidade infestante em áreas de transição para o café orgânico.

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    Objetivou-se com este trabalho verificar os efeitos dos insumos orgânicos e convencionais na dinâmica de plantas daninhas da lavoura durante o primeiro e o segundo ano de transição agroecológica. Para isso, montou-se um experimento em um cafezal de seis anos, onde iniciou-se a transição para o sistema de cultivo orgânico. A espécie mais importante no primeiro ano da transição, na maioria das áreas avaliadas, foi Ageratum conyzoides; no segundo ano ocorreu considerável mudança na relação de dominância entre as espécies, destacando-se Leunurus sibiricus na maior parte das áreas estudadas. Ocorreu também aumento do número de espécies presentes na maioria das áreas de um ano para o outro. No segundo ano de transição observou-se decréscimo na diversidade de espécies em relação ao primeiro ano. Dessa forma, pode-se concluir que nos dois anos de avaliação verificaram-se mudanças no número, na diversidade e na relação de importância entre as espécies de um ano para o outro

    Evidentialism and Moral Encroachment

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    Moral encroachment holds that the epistemic justification of a belief can be affected by moral factors. If the belief might wrong a person or group more evidence is required to justify the belief. Moral encroachment thereby opposes evidentialism, and kindred views, which holds that epistemic justification is determined solely by factors pertaining to evidence and truth. In this essay I explain how beliefs such as ‘that woman is probably an administrative assistant’—based on the evidence that most women employees at the firm are administrative assistants—motivate moral encroachment. I then describe weaknesses of moral encroachment. Finally I explain how we can countenance the moral properties of such beliefs without endorsing moral encroachment, and I argue that the moral status of such beliefs cannot be evaluated independently from the understanding in which they are embedded

    Genotype by Trait Relations between Yield and some Morphological Traits of Coconut (Cocos nucifera L.) Hybrid Varieties Based on GT Biplot

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    The objective of this study was to evaluate the coconut hybrid varieties based on Genotype by Traits (GT) biplot to examine its usefulness in visualizing coconut trait relationship and its application in genotypes comparison. The experimental design was a randomized complete block design with two replications; each block consisted of 5 plots with a total of eight palms per plot while the remaining palms were used as guard rows. This experiment was conducted at the Main Research Station of the Nigerian Institute for Oil Palm Research (NIFOR), Benin City, Edo State, Nigeria. The materials for the present study consisted of 5 hybrid varieties of Coconut palm. Data on individual palms were recorded on seven quantitative traits: thickness of petiole (TP), number of fronds (NFD), number of leaflets (NL), number of fruits per palm (NF), number of bunches per palm (NB), width of leaflet (WL) and circumference of the stem 20 cm from the soil level (CF).The GT biplot analysis revealed close associations among the studied traits. The two axes explained 90.4% of the total variation among the cultivars due to the various traits measured thus reflecting the accuracy of inter-relationships among the measured characters. Correlation coefficient between the studied traits showed that there is a strong positive relationship between number of fruit and number of bunches. These two traits were however negatively correlated with other traits except number of fronds. Based on the Auto Find QTL function of GGE biplot, bunch yield and width of leaflets were identified as traits suiTable for indirect selection for nut yield improvement. H4 was identified as an ideal genotype as it combines several good traits in its genetic composition and thus could serve as a good genetic raw material from which better cultivars, synthetic varieties and pure lines can be developed. H1 was the best in terms of nut and bunch yields, indicating that it can be used as parents in the development of hybrid varieties and populations that are outstanding in these traits

    Proximate Compositions Evaluation and Variability among Cultivars of Date Palm (Phoenix dactylifera L.) in Nigeria

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    Genetic variability among the fruits of 22 date palm cultivars was studied using 6 nutritional characters to enable us classify the available germplasm into distinct groups on the basis of their genetic diversity using their nutritional characteristics from proximate composition. The main date palm-growing areas of Nigeria were surveyed in 2011 with the objective of characterizing cultivars as to the quality and economic value of their fruits. Descriptive statistics and some multivariate analysis techniques were used to classify the 22 date palm cultivars. The genotypes based on studied traits were grouped into three clusters. Discriminant function analysis was used to confirm the accuracy of grouping that was produced by cluster analysis. Sugar and crude protein content were identified as important traits that could be used to differentiate the genotypes as revealed by both principal component and discriminant analysis. Genetic distance between Daushenga 1 and Saberari 2 exhibited the greatest dissimilarity followed by Daushenga 1 and Hausawa. Hence the use of these parents for hybridization should be given greater emphasis for the production of transgressive segregants with high nutritional potential. The level of variability observed suggested a high diversity among the cultivars. The result of the principal component analysis indicated that the contribution of the first three factors with Eigen value greater than one accounted for 73.03% of the total variation. The moderately high ash content shows that date palm fruit can effectively serve as a source of inorganic minerals and good adsorbent in the removal of metallic ions, odour, colours and other particulate matter from aqueous medium of water and waste water thus making date palm fruit an effective material precursor in water and waste water treatment among other uses. The high soluble carbohydrate content indeed gives an indication that it compares favourably with other fast energy giving food stuffs and thus it can be added to some food content as an additive .This work identified the existence of inherent variability in the local germplasm collections, and the traits that could be used to exploit the observed variability, eliciting important relationships among the traits in the process

    Chapter 10

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    Our purpose in this chapter is to help policymakers and researchers better understand and anticipate the likely impacts of climate change on agriculture and on vulnerable households in Nigeria. We do this by reviewing current data on agriculture and economic development, modeling anticipated changes in climate between now and 2050, using crop models to assess the impact of climate change on agricultural production, and globally modeling supply and demand for food to predict food price trends. Vulnerability to climate change is considered high in developing countries due to social, economic, and environmental conditions that amplify susceptibility to negative impacts and contribute to a low capacity to cope with and adapt to climate hazards. Because of the high level of vulnerability in developing countries, there is an urgent need to understand the threats from climate change that they face, formulate policies that mitigate the risks, and take necessary action. The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Parry et al. 2007) observed that information abou
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