Do we need a zero pure time preference or the risk of climate catastrophes to justify a 2C global warming target ?

This paper confronts the wide political support for the 2C objective of global increase in temperature, reaffirmed in Copenhagen, with the consistent set of hypotheses on which it relies. It explains why neither an almost zero pure time preference nor concerns about catastrophic damages in case of uncontrolled global warming are prerequisites for policy decisions preserving the possibility of meeting a 2C target. It rests on an optimal stochastic control model balancing the costs and benefits of climate policies resolved sequentially in order to account for the arrival of new information (the RESPONSE model). This model describes the optimal abatement pathways for 2,304 worldviews, combining hypotheses about growth rates, baseline emissions, abatement costs, pure time preference, damages, and climate sensitivity. It shows that 26 percent of the worldviews selecting the 2C target are not characterized by one of the extreme assumptions about pure time preference or climate change damages.Climate Change Mitigation and Green House Gases,Climate Change Economics,Science of Climate Change,Global Environment Facility,Environment and Energy Efficiency

Global characterization and target identification of piRNAs and endo-siRNAs in mouse gametes and zygotes

44 p.-1 tab.-10 fig.A set of small RNAs known as rasRNAs (repeat-associated small RNAs) have been related to the down-regulation of Transposable Elements (TEs) to safeguard genome integrity. Two key members of the rasRNAs group are piRNAs and endo-siRNAs. We have performed a comparative analysis of piRNAs and endo-siRNAs present in mouse oocytes, spermatozoa and zygotes, identified by deep sequencing and bioinformatic analysis. The detection of piRNAs and endo-siRNAs in the spermatozoa and revealed also in zygotes, hints to their potential delivery to oocytes during fertilization. However, a comparative assessment of the three cell types indicates that both piRNAs and endo-siRNAs are mainly maternally inherited. Finally, we have assessed the role of the different rasRNA molecules in connection with amplification processes by way of the "ping-pong cycle". Our results suggest that the ping-pong cycle can act on other rasRNAs, such as tRNA- and rRNA-derived fragments, thus not only being restricted to TEs during gametogenesis. © 2014 Elsevier B.V.This work was funded by grants from The European Chemical Industry Council Long-range Research Initiative (CEFIC-LRi), from the MEDDTL (11-MRESPNRPE-9-CVS-072), France, from the CSIC (PIE 201020E016), Spain.Peer reviewe

Assistive Technology User Groups and Early Childhood Educators

This article explores the potential of User Groups as a professional development venue for early childhood educators in developing operational and functional competence in using hardware and software components of an Assistive Technology (AT) Toolkit. User Groups are composed of varying numbers of participants having an interest in technology, and are led by one or more skilled facilitators who meet with participants across time to help them acquire and demonstrate new technology skill sets. A series of these groups were conducted with seven early education professionals serving young preschool children who were at risk or who had disabilities. The impact of these User Groups was examined using self-reports subsequent to User Group participation. Specific data were collected regarding the types of technologies that had been used, and the types of classroom instructional products that had been created and implemented in classrooms using the technologies. A discussion of the value of User Groups is presented

Building KidPad: An Application for Children's Collaborative Storytelling

Collaborating in small groups can be beneficial to children's learning and socializing. However, there is currently little computer support for children's collaborative activities. This was our motivation for building KidPad, a collaborative storytelling tool for children. KidPad provides children with drawing, typing, and hyperlinking capabilities in a large, two-dimensional canvas. It supports collaboration by accepting input from multiple mice. In building KidPad, we developed solutions to problems common to all single-display groupware applications for children: obtaining input from multiple devices, and using an intuitive user interface metaphor that can support collaboration. Our solution for obtaining input from multiple devices was MID, an architecture written in Java. We addressed the need for an appropriate user interface metaphor byusing the local tools metaphor. This paper describes our work on MID and local tools in the context of building of KidPad, and aims to provide developers with valuable insights into how to develop collaborative applications for children. (UMIACS-TR-2003-44) (HCIL-2003-18

The effect of four commercially available steel decontamination processes on the performance of external coatings

External coatings used for corrosion protection often have to perform under severely corrosive environments. One major concern regarding coating performance is the negative effect of soluble salts on the steel substrate at the time of coating application, particularly for marine maintenance coating applications. These salts impact the ability of the applied coating systems to protect the steel in several ways including osmotic coating blistering, promotion of under-film metallic corrosion and coating disbondment. This paper focuses on removal of soluble salts contamination by commercially available decontamination processes in relation to external coating systems. We directly compare the effectiveness of four cleaning methods with the performance of ten coating systems. The methodology of surface contamination and preparation of test panels is discussed. After cleaning, sample evaluation for chloride ion contamination levels was carried out using Field method (commercial chloride ion test kit for surfaces) and Ion Chromatography method. Additionally, Scanning Electron Microscopy Energy Dispersive X-ray Spectroscopy (SEM/EDX) and elemental surface mapping analysis were carried out. Laboratory testing of coating systems included Adhesion, Porosity, Electrochemical Impedance Spectroscopy (EIS) analysis and cyclic UV/Salt Fog exposure. The performance of the ten coatings on all the substrates was good, but there were differences in gloss retention and on the degree of checking of the different coatings. The only significant difference in performance of the coatings compared to the method used for cleaning the substrate was higher undercreep observed for most of the coatings applied to the ultra-high pressure water jetted system. This shows the importance of substrate preparation due to the sensitivity of the coatings to even low levels of salt. Two coatings did not show increased undercreep and these may be more applicable for offshore maintenance applications where dry abrasive blasting is sometimes not used. The chemical treatment cleaning method used prior to coating application did not show any significant positive or negative effect on the performance of the applied coatings. The fact that the only differences in performance for the coatings applied to the differently prepared substrates was seen for undercreep suggests that the difference may be exacerbated for immersion situations. A follow up study to this one will examine the performance of internal coatings using immersion tests, and it will be interesting to see if these show increased effect on coating performance

Accuracy, Target Reentry and Fitts' Law Performance of Preschool Children Using Mice

Several experiments by psychologists and human factors researchers have shown that when young children execute pointing tasks, they perform at levels below older children and adults. However, these experiments were not conducted with the purpose of providing guidelines for the design of graphical user interfaces. To address this need, we conducted a study to gain a better understanding of 4 and 5 year-old children's use of mice. We compared the performance of thirteen 4 year-olds, thirteen 5 year-olds and thirteen young adults in point-and-click tasks. As expected, we found age had a significant effect on accuracy, target reentry and Fitts' law's index of performance. We also found that target size had a significant effect on accuracy and target reentry. Measuring movement time at four different times (first entering target, last entering target, pressing button, releasing button) yielded the result tha Fitts' law models children well only for the first time they enter the target. Another interesting result was that using the adjusted index of difficulty (IDe) in Fitts' law calculations yielded lower linear regression correlation coefficients than using the unadjusted index of difficulty (ID). These results provide valuable guidelines for the design of graphical user interfaces for young children, in particular when it comes to sizing visual targets. They also suggest designers should adopt strategies to accommodate users with varying levels of skill. (UMIACS-2003-42) (HCIL-2003-16

The International Children's Digital Library: Viewing Digital Books Online

Reading books plays an important role in children's cognitive and social development. However, many children do not have access to diverse collections of books due to the limited resources of their community libraries. We have begun to address this issue by creating a large-scale digital archive of children's books, the International Children's Digital Library (ICDL). In this paper we discuss our initial efforts in building the ICDL, concentrating on an informal evaluation of innovative digital book readers. Keywords Children, digital libraries, books, book readers, graphical user interfaces. (UMIACS-TR-2002-09) (HCIL-TR-2002-03

A Collaborative Digital Library for Children: A Descriptive Study of Children's Collaborative Behavior and Dialogue

Over the last three years, we have been developing a collaborative digital library interface where two children can collaborate using multiple mice on a single computer to access multimedia information concerning animals. This technology, called "SearchKids" leverages our lab's past work in co-present collaborative zoomable interfaces for young children. This paper describes the differences in children's collaborative behavior and dialogue when using two different software conditions to search for animals in the digital library. In this study, half the children had to "confirm" their collaborative activities (e.g., both children had to click on a given area to move to that area). The other half used an "independent" collaboration technique (e.g., just one mouse click allows the pair to move to that area). The participants in this study were 98 second and third grade children (ages 7-9 years old) from a suburban public elementary school in Prince George's County, Maryland. The children were randomly divided into two groups and paired with a classmate of the same gender. Each pair was asked to find as many items as possible from a list of 20 items given a limit of 20 minutes. Sessions were video taped and the first and last five minutes of each session were coded for discussion type and frequency. The results of our study showed distinct differences between groups in how children discussed their shared goals, collaborative tasks, and what outcomes they had in successfully finding multimedia information in the digital library. These findings suggest various ways educators might use and technologists might develop new collaborative technologies for learning. Keywords Children, Collaboration, Computer-Supported Collaborative Learning, Digital Libraries, Educational Applications, Single Display Groupware (SDG), SearchKids, Zoomable User Interfaces (ZUIs) (UMIACS-TR-2002-46) (HCIL-TR-2002-07

Young Children's Search Strategies and Construction of Search Queries

This paper describes a quantitative study focused on two questions: (1) Can children understand and use a hierarchical domain structure to find particular instances of animals? (2) Can children construct search queries to conduct complex searches if sufficiently supported, both visually and conceptually? These two questions have been explored in the context of developing a digital library interface (called "QueryKids") for children ages 5-10 years old that visualizes the querying process and its results. The results of this study showed that children were able to search very efficiently, primarily using a "fewest-steps" strategy, with the QueryKids software prototype. In addition, children were able to construct search queries with a high degree of accuracy. Results are discussed in terms of the scaffolding support that QueryKids provides, and its effectiveness in helping children to search efficiently and construct complex search queries. Keywords: Children, information retrieval, digital libraries, empirical evaluation, education applications (Also cross-referenced as HCIL 2000-19) (Also cross-referenced as UMIACS-TR-2000-68

Chapter 6 - Assessing transformation pathways

Stabilizing greenhouse gas (GHG) concentrations at any level will require deep reductions in GHG emissions. Net global CO2 emissions, in particular, must eventually be brought to or below zero. Emissions reductions of this magnitude will require large-scale transformations in human societies, from the way that we produce and consume energy to how we use the land surface. The more ambitious the stabilization goal, the more rapid this transformation must occur. A natural question in this context is what will be the transformation pathway toward stabilization; that is, how do we get from here to there? The topic of this chapter is transformation pathways. The chapter is motivated primarily by three questions. First, what are the near-term and future choices that define transformation pathways including, for example, the goal itself, the emissions pathway to the goal, the technologies used for and sectors contributing to mitigation, the nature of international coordination, and mitigation policies? Second, what are the key decision making outcomes of different transformation pathways, including the magnitude and international distribution of economic costs and the implications for other policy objectives such as those associated with sustainable development? Third, how will actions taken today influence the options that might be available in the future? Two concepts are particularly important for framing any answers to these questions. The first is that there is no single pathway to stabilization of GHG concentrations at any level. Instead, the literature elucidates a wide range of transformation pathways. Choices will govern which pathway is followed. These choices include, among other things, the long-term stabilization goal, the emissions pathway to meet that goal, the degree to which concentrations might temporarily overshoot the goal, the technologies that will be deployed to reduce emissions, the degree to which mitigation is coordinated across countries, the policy approaches used to achieve these goals within and across countries, the treatment of land use, and the manner in which mitigation is meshed with other policy objectives such as sustainable development. The second concept is that transformation pathways can be distinguished from one another in important ways. Weighing the characteristics of different pathways is the way in which deliberative decisions about transformation pathways would be made. Although measures of aggregate economic implications have often been put forward as key deliberative decision making factors, these are far from the only characteristics that matter for making good decisions. Transformation pathways inherently involve a range of tradeoffs that link to other national and policy objectives such as energy and food security, the distribution of economic costs, local air pollution, other environmental factors associated with different technology solutions (e.g., nuclear power, coal-fired carbon dioxide capture and storage (CCS)), and economic competitiveness. Many of these fall under the umbrella of sustainable development. A question that is often raised about particular stabilization goals and transformation pathways to those goals is whether the goals or pathways are "feasible". In many circumstances, there are clear physical constraints that can render particular long-term goals physically impossible. For example, if additinional mitigation beyond that of today is delayed to a large enough degree and carbon dioxide removal (CDR) options are not available (see Section 6.9), a goal of reaching 450 ppm CO2eq by the end of the 21st century can be physically impossible. However, in many cases, statements about feasibility are bound up in subjective assessments of the degree to which other characteristics of particular transformation pathways might influence the ability or desire of human societies to follow them. Important characteristics include economic implications, social acceptance of new technologies that underpin particular transformation pathways, the rapidity at which social and technological systems would need to change to follow particular pathways, political feasibility, and linkages to other national objectives. A primary goal of this chapter is to illuminate these characteristics of transformation pathways