3,842 research outputs found
Deduction over Mixed-Level Logic Representations for Text Passage Retrieval
A system is described that uses a mixed-level representation of (part of)
meaning of natural language documents (based on standard Horn Clause Logic) and
a variable-depth search strategy that distinguishes between the different
levels of abstraction in the knowledge representation to locate specific
passages in the documents. Mixed-level representations as well as
variable-depth search strategies are applicable in fields outside that of NLP.Comment: 8 pages, Proceedings of the Eighth International Conference on Tools
with Artificial Intelligence (TAI'96), Los Alamitos C
Temperature-Dependence of the Solid-Electrolyte Interphase Overpotential: Part I. Two Parallel Mechanisms, One Phase Transition
It has been shown recently that the overpotential originating from ionic
conduction of alkali-ions through the inner dense solid-electrolyte interphase
(SEI) is strongly non-linear. An empirical equation was proposed to merge the
measured resistances from both galvanostatic cycling (GS) and electrochemical
impedance spectroscopy (EIS) at 25C. Here, this analysis is extended
to the full temperature range of batteries from -40C to
+80C for Li, Na, K and Rb-metal electrodes in carbonate electrolytes.
Two different transport mechanisms are found. The first one conducts
alkali-ions at all measured temperatures. The second transport mechanism
conducts ions for all seven measured Li-ion electrolytes and one out of four
Na-ion electrolytes, however, only above a certain critical temperature .
At a phase transition is observed switching-off the more efficient
transport mechanism and leaving only the general ion conduction mechanism. The
associated overpotentials increase rapidly below depending on alkali-ion,
salt and solvent and become a limiting factor during galvanostatic operation of
all Li-ion electrolytes at low temperature. In general, the current analysis
merges the SEI resistances measured by EIS ranging from 26 cm for
the best Li up to 292 Mcm for Rb electrodes to its galvanostatic
response over seven orders of magnitude. The determined critical temperatures
are between 0-25C for the tested Li and above 50C for Na
electrolytes.Comment: 10 pages, 7 figures, file includes Suppl Info,
http://jes.ecsdl.org/content/165/2/A32
Real-time graphics for the Space Station Freedom cupola, developed in the Systems Engineering Simulator
Among the Lyndon B. Johnson Space Center's responsibilities for Space Station Freedom is the cupola. Attached to the resource node, the cupola is a windowed structure that will serve as the space station's secondary control center. From the cupola, operations involving the mobile service center and orbital maneuvering vehicle will be conducted. The Systems Engineering Simulator (SES), located in building 16, activated a real-time man-in-the-loop cupola simulator in November 1987. The SES cupola is an engineering tool with the flexibility to evolve in both hardware and software as the final cupola design matures. Two workstations are simulated with closed-circuit television monitors, rotational and translational hand controllers, programmable display pushbuttons, and graphics display with trackball and keyboard. The displays and controls of the SES cupola are driven by a Silicon Graphics Integrated Raster Imaging System (IRIS) 4D/70 GT computer. Through the use of an interactive display builder program, SES, cupola display pages consisting of two dimensional and three dimensional graphics are constructed. These display pages interact with the SES via the IRIS real-time graphics interface. The focus is on the real-time graphics interface applications software developed on the IRIS
Doorways to Development: Foreign Direct Investment Policies in Developing Countries
Foreign direct investment (FDI) is a key option for economic growth in most, if not all, developing countries. However, not all developing countries are equally open to foreign investment. Some restrict foreign equity, while others encourage multinational corporations to enter their markets. Because FDI involves outsiders entering national markets and profits, it is very political. FDI can bring economic benefits, such as jobs and new technology, but it may also entail economic costs, such as increased competition for national businesses. FDI may also bring political costs, as governments that open to foreign equity may see a popular backlash. Most governments have policies to control FDI\u27s entry into their markets. These policies have been inadequately explored in quantitative studies of FDI because of a lack of available data. This study seeks to rectify that problem by introducing a new set of data: The Foreign Equity Index. I develop a theory and model of FDI in developing countries framed by the logic of two-level games. FDI requires agreement between developing states and international firms, and therefore agreements are reached with influence from domestic-level political and economic factors, as well as international-level factors. FDI policies are an indication of developing countries win-sets, or range of agreements they are willing to accept when dealing with foreign multinational corporations. I test this theory quantitatively using the Foreign Equity Index, which covers 55 developing countries from 1976-2004. I first estimate the international and domestic factors that influence the degree of openness to FDI indicated by FDI equity policies in developing countries. I then test the effect these policies have on FDI inflows. I find that both domestic and international factors affect developing countries’ FDI policies, and in turn, policies are a significant factor determining the flow of FDI into national markets. I also explore the ways in which FDI policies have played a role in economic development strategies of El Salvador and Nicaragua. This research and the Foreign Equity Index should aid in a better understanding of foreign direct investment and growth in developing countries in general
The Role of System XC- in Cognition: The Importance of Neuron-Astrocyte Signaling
The biological basis of human intelligence is largely a mystery, but likely required evolutionary adaptations to achieve the information processing capacity needed to expand the complexity of cognition among species. The link between evolutionary expansion of signaling complexity in the brain and cognition has largely focused on neuronal mechanisms, in part because information processing has historically been attributed to these cells. However, astrocytes are emerging as a second type of brain cell that is capable of processing information due to their capacity to release glutamate and, thereby, regulate neural circuits. Hence, a modern question is whether astrocytes contributed to the signaling complexity required for sophisticated forms of cognition. The glutamate release mechanism system xc- (Sxc) is the ideal mechanism to investigate this question because it is evolutionarily novel to vertebrate species and it is expressed by astrocytes. The central hypothesis tested herein is that Sxc increased the complexity of glutamate signaling and is required for behavior requiring complex cognition. To test, a genetically modified rat with Sxc activity eliminated was generated (MSxc rats). Phenotyping revealed that loss of Sxc activity produced changes in behavior that reflect diminished cognition or top-down processing including impaired reversal learning, set-shifting, and attentional allocation. Remarkably, loss of Sxc did not impact central regulation of metabolism, Pavlovian conditioning, instrumental conditioning, locomotor activity, and novel-object recognition. Additionally, Sxc is integral to the regulation of neural networks. In the nucleus accumbens, we found that a loss of Sxc altered synaptic strength in a circuit specific manner. Further, we found that Sxc-mediated glutamate release is regulated by presynaptic (the neuropeptide PACAP), postsynaptic (endocannabinoid) and hormonal (glucocorticoids) signaling mechanisms. Further interrogation of Sxc regulation by PACAP revealed that this neuropeptide acts on both neurons and astrocytes to facilitate bidirectional neuron-astrocyte signaling between Sxc and extrasynaptic NMDA receptors. The in vivo relevance of this mechanism is established by our findings that PACAP microinjected into the nucleus accumbens attenuates cocaine-primed reinstatement, and the regulation of this behavior requires both Sxc and NMDA receptors. These findings support the possibility that future therapeutics could restore cognition by targeting astrocytes
Beyond Justiciability: Political Gerrymandering after Davis v. Bandemer
This article examines the decision in Davis v. Bandemer, as well as the political circumstances that resulted in unusual legal alliances during the appeal. The article also attempts to dispel at least some of the confusion surrounding the decision
European American Therapist Self-Disclosure in Cross-Cultural Counseling
Eleven European American psychotherapists\u27 use of self-disclosure in cross-cultural counseling was studied using consensual qualitative research. As reasons for self-disclosing, therapists reported the intent to enhance the counseling relationship, acknowledge the role of racism/oppression in clients\u27 lives, and acknowledge their own racist/oppressive attitudes. Results indicated that therapists typically shared their reactions to clients\u27 experiences of racism or oppression and that these self-disclosures typically had positive effects in therapy, often improving the counseling relationship by helping clients feel understood and enabling clients to advance to other important issues
- …