16 research outputs found
Would There Be Surplus Grains for Biofuels? An Assessment of Agro-economic Factors and Biofuel Production Potential at the Global Level
No full textPaper removed for editing by author 10/19/11.biofuel, land resources, productivity increase, food supply, Crop Production/Industries, Resource /Energy Economics and Policy, Q0, Q42, Q18,
'Operation Enduring Nightmare'? : a strategic critique of the military intervention in Afghanistan from October 2001-October 2008
No full textIncludes abstract.Includes bibliographical references.In October 2011, the war in Afghanistan reached its ignominious ten year anniversary. As the conflict rolls on relentlessly, observers from across all disciplines, and indeed the general public themselves, have attempted to identify why the intervention, which began as Operation Enduring Freedom, has instead become an ‘Enduring Nightmare’. This dissertation attempts to provide empirical reasoning to this question by means of a literature review of the established strategic critiques of the intervention between the years of October 2001 and October 2008
Urban Road Transportation Externalities: Costs and Choice of Policy Instruments
No full textUrban transportation externalities are a key development challenge. Based on the existing literature, the authors illustrate the magnitudes of various external costs, review response policies, and measure and discuss their selection, particularly focusing on the context of developing countries. They find that regulatory policy instruments aimed at reducing local air pollution have been introduced in most countries in the world. On the other hand, fiscal policy instruments aimed at reducing congestion or greenhouse gas emissions are limited mainly to industrialized economies. Although traditional fiscal instruments, such as fuel taxes and subsidies, are normally introduced for other purposes, they can also help to reduce externalities. Land-use or urban planning, and infrastructure investment, could also contribute to reducing externalities; but they are expensive and play a small role in already developed megacities. The main factors that influence the choice of policy instruments include economic efficiency, equity, country or city specific priority, and institutional capacity for implementation. Multiple policy options need to be used simultaneously to reduce effectively the different externalities arising from urban road transportation because most policy options are not mutually exclusive. Copyright The Author 2010. Published by Oxford University Press on behalf of the International Bank for Reconstruction and Development / <sc>the world bank</sc>. All rights reserved. For permissions, please e-mail: [email protected], Oxford University Press.
Semi-supervised regression using diffusion on graphs
No full textIndexación ScopusIn real-world machine learning applications, unlabeled training data are readily available, but labeled data are expensive and hard to obtain. Therefore, semi-supervised learning algorithms have gathered much attention. Previous studies in this area mainly focused on a semi-supervised classification problem, whereas semi-supervised regression has received less attention. In this paper, we proposed a novel semi-supervised regression algorithm using heat diffusion with a boundary-condition that guarantees a closed-form solution. Experiments from artificial and real datasets from business, biomedical, physical, and social domain show that the boundary-based heat diffusion method can effectively outperform the top state of the art methods. © 2021 The Author(s)https://www-sciencedirect-com.recursosbiblioteca.unab.cl/science/article/pii/S1568494621001113?via%3Dihu
Effect Of Company Size On Manager's Perception
No full textThe purpose of this study is to explore the effect of a company’s size on its manager’s perception towards changes in market needs and manufacturing flexibility. To serve the purpose,a questionnaire was designed by considering different types of manufacturing flexibility and changes occurring in market needs. The collected data were then analyzed to verify the proposed hypotheses. The results showed that a company’s size significantly influence manager’s perception towards manufacturing flexibility and market requirements. For instance,reliability is given higher priority by managers of micro and small enterprises in comparison with managers of medium and large enterprises. Similarly, routine flexibility is found to be significantly more important to managers of micro and small enterprises, while production facility flexibility is considered more important by managers of medium and large enterprises. Furthermore, the results showed that there is a positive relationship between changes in market requirements and manufacturing flexibility, showing that manufacturing flexibility is governed by changes in market requirements. This research was conducted with managers at various companies in the energy sector; so the results may not be applicable to other industries.© 2014 The author(s). The article is published under the terms of the Creative Commons Attribution-Non-Commercial-NoDerivs license (https://creativecommons.org/licenses/by-nc-nd/3.0/).fi=vertaisarvioitu|en=peerReviewed
Exploring the Possibility of Linking and Incorporating Future Design in Backcasting and Scenario Planning
No full textThere are two approaches to future planning: backcasting and scenario planning. While some studies have attempted to relate and combine these two approaches, a future design (FD) approach has recently been advocated and researched. Given this state of affairs, the paper provides an overview of the FD approach and discusses the potential benefits of linking and incorporating it into backcasting and scenario planning by summarizing the main features of such benefits for future planning for sustainability. A feature of an FD is that it explicitly orients people’s ways of thinking in the current generation to be generative for not only their own future but also generations to come, as well as in designing a plan within a coherent timeframe by demonstrating the characteristics of being prospective and retrospective from the viewpoint of a different generation. Another feature of FD lies in strategy making through some visioning process and in redefining the boundary between what is controllable and what is uncontrollable by considering the perspectives of future generations. We consider this article as a concept paper for the special issue of “Designing Sustainable Future Societies,” building on a literature review and author’s conceptual framework. Thus, our ideas and concepts suggest some potential benefits from incorporating FD into backcasting and scenario planning, further inducing people to be future-oriented and/or sustainable in terms of strategy making. We finally demonstrate some examples of FD practices and illustrative ideas of FD incorporation, remarking on possible avenues for future research
Providing Numbers for a Food versus Fuel Debate: An Analysis of a Future Biofuel Production Scenario
No full textThis study provides a quantitative estimate of grain that would be available for biofuel production under different scenarios of dietary requirements in the world in 2050 based on the projected information available in 2007 on population, productivity increase, dietary requirements, and land use types. Our major findings are as follows: (1) if dietary requirements do not increase by more than 20% from the current level, crop yields from current cropland must increase by more than 57% just to meet dietary demand; (2) the restriction of pastureland for milk and meat production purposes would imply insufficient food production for a moderate diet consumption scenario in 2050; (3) If food demand increases by 20% of the current consumption level, a 60% increase in crop yield and a 16% conversion of pasturelands would meet grain demand and leave surplus grain to supply 23% of liquid fuel demand. We also highlight the potential roles played by biotechnology, research and development fundings, irrigation, and cropping intensity to boost crop production and ultimately make more land available for biofuel production if such an option continues to be considered in future. © The Author(s) 2012. Published by Oxford University Press, on behalf of Agricultural and Applied Economics Association. All rights reserved
Bacterial Mutation During Seasonal Epidemics
No full textRapidly evolving bacterial pathogens pose a unique challenge for long-term plant disease management. In this study, we investigated the types and rate of mutations in bacterial populations during seasonal disease epidemics. Two phylogenetically distinct strains of the bacterial spot pathogen, Xanthomonas perforans, were marked, released in tomato fields, and recaptured at several time points during the growing season. Genomic variations in recaptured isolates were identified by comparative analysis of their whole-genome sequences. In total, 180 unique variations (116 substitutions, 57 insertions/deletions, and 7 structural variations) were identified from 300 genomes, resulting in the overall host-associated mutation rate of ∼0.3 to 0.9/genome/week. This result serves as a benchmark for bacterial mutation during epidemics in similar pathosystems. [Graphic: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license
Modeling hydrologic processes associated with soil saturation and debris flow initiation during the September 2013 storm, Colorado Front Range
No full text2019 Summer.Includes bibliographical references.Seven days of extreme rainfall during September 2013 produced more than 1,100 debris flows in the Colorado Front Range, about 78% of which occurred on south-facing slopes (SFS). A few previously-published soil moisture observations suggest that SFS were wetter than north-facing slopes (NFS) during the event, which would contrast with soil moisture patterns observed during dry conditions. Various causes have been hypothesized for the preferential saturation of SFS, but those hypotheses remain largely untested. The objectives of this study are to analyze the soil moisture patterns using additional soil moisture observations, determine the hydrologic processes behind the preferential saturation of SFS, and to evaluate the importance of soil moisture in determining the debris flow initiation sites. Soil moisture patterns are simulated using the Equilibrium Moisture from Topography, Vegetation, and Soil (EMT+VS) model for a study region that includes 63% of the observed debris flow locations. Five hypotheses are implemented in the model including: (1) higher rainfall rates, (2) lower interception rates, (3) lower porosity, (4) thinner soils, and (5) reduced deep drainage on SFS. The EMT+VS model is also coupled with an infinite slope stability model to produce factor of safety maps. The hypotheses are tested by comparing the modeled soil moisture patterns to soil moisture observations and the debris flow initiation sites. The results suggest that differences in interception and deep drainage between the slopes were primarily responsible for producing wetter SFS, but the soil moisture pattern likely played a smaller role than vegetation and slope in determining the debris initiation sites
Temporal changes in cell division rate and genotoxic stress tolerance in quiescent center cells of Arabidopsis primary root apical meristem
No full textPlant roots provide structural support and absorb nutrients and water; therefore, their proper development and function are critical for plant survival. Extensive studies on the early stage of ontogenesis of the primary root have revealed that the root apical meristem (RAM) undergoes dynamic structural and organizational changes during early germination. Quiescent center (QC) cells, a group of slowly dividing cells at the center of the stem-cell niche, are vital for proper function and maintenance of the RAM. However, temporal aspects of molecular and cellular changes in QC cells and their regulatory mechanisms have not been well studied. In the present study, we investigated temporal changes in QC cell size, expression of QC cell-specific markers (WOX5 and QC25), and genotoxic tolerance and division rate of QC cells in the Arabidopsis primary root. Our data revealed the decreased size of QC cells and the decreased expression of the QC cell-specific markers with root age. We also found that QC cell division frequency increased with root age. Furthermore, our study provides evidence supporting the link between the transition of QC cells from a mitotically quiescent state to the frequently dividing state and the decrease in tolerance to genotoxic stress. © 2019, The Author(s
