990 resultados para Potential of zero total charge


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Organic geochemical studies on samples from Holes 487, 488, and 490 in the southern Mexico Middle America Trench provided an opportunity to characterize the organic fraction of the sedimentary section in an active trench environment and to project the petroleum-producing potential of the extracted lipid fractions. The samples were geologically young and of shallow burial history. Samples from Hole 487, located on the oceanic plate, range in age from late Miocene to middlelate Pleistocene. Samples from Hole 488, representing undifferentiated Quaternary sediment, were collected on the landward side of the lower trench slope. Miocene(?) to Quaternary sediments from Hole 490 were obtained from the upper slope immediately seaward of the inferred location of the continental crust.

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The Green Economy offers real possibilities for productive innovation, economic growth and employment creation in Spain. These three factors are critical to facilitate the necessary change in the productive model to overcome the crisis. However, the measures taken by the current Conservative government have moved in the opposite direction: significant cutting in incentives for renewable, increasing tax burden on renewable energy production to self-consumption and privatizing public spaces of social and environmental interest. This hinders the achievement of the environmental objectives of the Europe 2020 strategy. A strategy that is born already in itself highly limited, unambitious and subordinated to the interests of energy oligopolies and the imperatives of the Stability and Growth Pact (Maastricht) and the Austerity policies imposed from EU institutions to overcome the 2008 financial crisis. So the Ecological Transition goes further, claiming a substantially change in Economic Policy away form the increasing commodification proposed by the Green Economy. Despite these limitations, young and unemployed people have much to gain from a comprehensive development of environmental industries. Therefore, innovative-sustainable plans, investment and training in green sectors are necessary to make easier the transition from a services low-valued economy to an innovative and sustainable model to make our country an environmental reference in Europe.

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Cassava is one of the major food crops in Nigeria, with multiple uses from human consumption to industrial applications. This study explores the potential of cassava in Nigerian agriculture based on a review of cassava development policies; performs a trend analysis of the cultivation area, production, productivity, and real price of cassava and other competing crops for the period 1961–2013; identifies the sources of growth in production; and examines the production constraints at the local level based on a survey of 315 farmers/processors and 105 marketers from Delta State. The results revealed that several policies and programmes were implemented to develop the cassava sector with mixed outcomes. Although cassava productivity grew at 1.5% per annum (p.a.) during the post-structural adjustment programme period (1993–2013), its real price declined at a rate of 3.5% p.a. The effect of yield is the main source of growth in production, contributing 76.4% of the total growth followed by the area effect (28.2%). The cassava sector is constrained by inadequate market infrastructure, processing facilities, and lack of information and unstable prices at the local level. The widespread diffusion of improved tropical manioc selection technologies and investments in market and marketing infrastructure, processing technologies, irrigation/water provision and information dissemination are recommended to enhance the potential of the cassava sector to support agricultural growth in Nigeria.

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Increased productivity in sorghum has been achieved in the developed world using hybrids. Despite their yield advantage, introduced hybrids have not been adopted in Ethiopia due to the lack of adaptive traits, their short plant stature and small grain size. This study was conducted to investigate hybrid performance and the magnitude of heterosis of locally adapted genotypes in addition to introduced hybrids in three contrasting environments in Ethiopia. In total, 139 hybrids, derived from introduced seed parents crossed with locally adapted genotypes and introduced R lines, were evaluated. Overall, the hybrids matured earlier than the adapted parents, but had higher grain yield, plant height, grain number and grain weight in all environments. The lowland adapted hybrids displayed a mean better parent heterosis (BPH) of 19%, equating to 1160 kg ha− 1 and a 29% mean increase in grain yield, in addition to increased plant height and grain weight, in comparison to the hybrids derived from the introduced R lines. The mean BPH for grain yield for the highland adapted hybrids was 16% in the highland and 52% in the intermediate environment equating to 698 kg ha− 1 and 2031 kg ha− 1, respectively, in addition to increased grain weight. The magnitude of heterosis observed for each hybrid group was related to the genetic distance between the parental lines. The majority of hybrids also showed superiority over the standard check varieties. In general, hybrids from locally adapted genotypes were superior in grain yield, plant height and grain weight compared to the high parents and introduced hybrids indicating the potential for hybrids to increase productivity while addressing farmers' required traits.

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Mangrove ecosystems are environments subject to substantial degradation by anthropogenic activities. Its location, in coastal area, interfacing the continents and the oceans makes it substantially important in the prospection for biotechnological applications. In this study, we assessed the diversity of culturable bacteria present over the seasons at two depths (0-10 and 30-40 cm) in a mangrove sediment and in a transect area from the land to the sea. In total, 238 bacteria were isolated, characterized by Amplified Ribosomal DNA Restriction Analysis (ARDRA) and further identified, by Fatty Acid Methyl Esther (FAME-MIDI), into the orders of Vibrionales, Actinomycetales and Bacillales. Also the ability of the isolates in producing economically important enzymes (amylases, proteases, esterases and lipases) was evaluated and the order Vibrionales was the main enzymatic source.

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Purpose: This study was aimed to evaluate the antioxidant activity of the methanol extract of Euphorbia spinidens (Euphorbiaceae) and its effect on Herpes simplex virus type-1 (HSV-1) replication. Methods: The methanol extract of aerial parts of E. spinidens collected from Khorasan State in North- Eastern part of Iran was used in this study. Total phenolic, flavonoid contents and the antioxidant activity were evaluated using Folin-Ciocalteu method, aluminum chloride colorimetric method and β- carotene-linoleate model system, respectively. Both the cytotoxic and antiviral effects of the crude extract on Vero cell line were determined by quantifying the viability of Vero cells using 3-(4,5- dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)2H-tetrazolium (MTS) assay. Results: Total phenolic and flavonoid contents of E.spinidens were 70 ± 1 mg of gallic acid equivalent/g of dry extract (mg GAE/g extract) and 49.66 ± 1.00 mg rutin equivalent/g of dry extract (mg RTN/g extract), respectively. Antioxidant activity was 44 ± 1 % compared with the standard, buthylated hydroxytuloene (BHT). The 50 % cytotoxic concentration (CC50) of the extract on Vero cells was 5.072 ± 0.063 mg/ml and its antiviral concentration of 50 % effectiveness (EC50) value was 0.34 ± 0.003 mg/ml. Conclusion: The findings of this study show that the methanol extract of E. spinidens has high content of phenolic and flavonoid compounds with good antioxidant activity. Furthermore, this extract has significant antiviral effect on HSV-1 probably due to the inhibition of viral replication.

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An approach to reduce the contamination of water sourceswith pesticides is the use of biopurificaction systems. The active core of these systems is the biomixture. The composition of biomixtures depends on the availability of local agro-industrial wastes and design should be adapted to every region. In Portugal, cork processing is generally regarded as environmentally friendly and would be interesting to find applications for its industry residues. In this work the potential use of different substrates in biomixtures, as cork (CBX); cork and straw, coat pine and LECA (Light Expanded Clay Aggregates), was tested on the degradation of terbuthylazine, difenoconazole, diflufenican and pendimethalin pesticides. Bioaugmentation strategies using the white-rot fungus Lentinula edodes inoculated into the CBX, was also assessed. The results obtained from this study clearly demonstrated the relevance of using natural biosorbents as cork residues to increase the capacity of pesticide dissipation in biomixtures for establishing biobeds. Furthermore, higher degradation of all the pesticides was achieved by use of bioaugmented biomixtures. Indeed, the biomixtures inoculated with L. edodes EL1were able to mineralize the selected xenobiotics, revelling that these white-rot fungi might be a suitable fungus for being used as inoculum sources in on-farm sustainable biopurification system, in order to increase its degradation efficiency. After 120 days, maximum degradation of terbuthylazine, difenoconazole, diflufenican and pendimethalin, of bioaugmented CBX, was 89.9%, 75.0%, 65.0% and 99.4%, respectively. The dominant metabolic route of terbuthylazine in biomixtures inoculated with L. edodes EL1 proceeded mainly via hydroxylation, towards production of terbuthylazine-hydroxy-2 metabolite. Finally, sorption process to cork by pesticides proved to be a reversible process,working cork as a mitigating factor reducing the toxicity to microorganisms in the biomixture, especially in the early stages.

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Shared Services (SS) involves the convergence and streamlining of an organisation’s functions to ensure timely service delivery as effectively and efficiently as possible. As a management structure designed to promote value generation, cost savings and improved service delivery by leveraging on economies of scale, the idea of SS is driven by cost reduction and improvements in quality levels of service and efficiency. Current conventional wisdom is that the potential for SS is increasing due to the increasing costs of changing systems and business requirements for organisations and in implementing and running information systems. In addition, due to commoditisation of large information systems such as enterprise systems, many common, supporting functions across organisations are becoming more similar than not, leading to an increasing overlap in processes and fuelling the notion that it is possible for organisations to derive benefits from collaborating and sharing their common services through an inter-organisational shared services (IOSS) arrangement. While there is some research on traditional SS, very little research has been done on IOSS. In particular, it is unclear what are the potential drivers and inhibitors of IOSS. As the concepts of IOSS and SS are closely related to that of Outsourcing, and their distinction is sometimes blurred, this research has the first objective of seeking a clear conceptual understanding of the differences between SS and Outsourcing (in motivators, arrangements, benefits, disadvantages, etc) and based on this conceptual understanding, the second objective of this research is to develop a decision model (Shared Services Potential model) which would aid organisations in deciding which arrangement would be more appropriate for them to adopt in pursuit of process improvements for their operations. As the context of the study is on universities in higher education sharing administrative services common to or across them and with the assumption that such services were homogenous in nature, this thesis also reports on a case study. The case study involved face to face interviews from representatives of an Australian university to explore the potential for IOSS. Our key findings suggest that it is possible for universities to share services common across them as most of them were currently using the same systems although independently.

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Belonging to an online community offers teachers the opportunity to exchange ideas, make connections with a wider peer group and form collaborative networks. The increasing popularity of teacher professional communities means that we need to understand how they work and determine the role they may play in teacher professional development. This chapter will map data from a doctoral study to a recentlydeveloped model of professional development to offer a new perspective of how online communities can add to a teacher’s personal and professional growth and, in so doing, add to the small number of studies in this field. This chapter will conclude with a call for a revision of the way we approach professional development in the 21st century and suggest that old models and metaphors are hindering the adoption of more effective means of professional development for teachers.

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To date, mesenchymal stem cells (MSCs) from various tissues have been reported, but the yield and differentiation potential of different tissue-derived MSCs is still not clear. This study was undertaken in an attempt to investigate the multilineage stem cell potential of bone and cartilage explant cultures in comparison with bone marrow derived mesenchymal stem cells (BMSCs). The results showed that the surface antigen expression of tissue-derived cells was consistent with that of mesenchymal stem cells, such as lacking the haematopoietic and common leukocyte markers (CD34, CD45) while expressing markers related to adhesion (CD29, CD166) and stem cells (CD90, CD105). The tissue-derived cells were able to differentiate into osteoblast, chondrocyte and adipocyte lineage pathways when stimulated in the appropriate differentiating conditions. However, compared with BMSCs, tissue-derived cells showed less capacity for multilineage differentiation when the level of differentiation was assessed in monolayer culture by analysing the expression of tissue-specific genes by reverse transcription polymerase chain reaction (RT-PCR) and histology. In high density pellet cultures, tissue-derived cells were able to differentiate into chondrocytes, expressing chondrocyte markers such as proteoglycans, type II collagen and aggrecan. Taken together, these results indicate that cells derived from tissue explant cultures reserved certain degree of differentiation properties of MSCs in vitro.