373 research outputs found
Cross-Service Investigation of Geographical Information Systems
This research investigated the armed services current uses of GIS, and asked the question whether or not a joint GIS program could benefit the DOD. An information technology implementation model was presented as a framework to implement a joint GIS program. It was found that all four armed services use GIS for forward deployments. The Army has its Combat Terrain Information System (CTIS). The Navy\u27s digital nautical charts are a GIS. The Marine Corps has created their Geographically Linked Information Display Environment (GLIDE) program, which is similar to a map repository. Finally, the Air Force has its GeoBase program for installation GIS, and GeoReach is the expeditionary deployment base-planning subset. The research methodology combined a case study and a Delphi study. The case study research examined a single Army GIS unit for current GIS implementation methods and uses. The Delphi study asked eight DOD GIS experts their opinions about current GIS uses and the possibility of a joint GIS program. Through the case study and Delphi research, it was found that information flow between the services is limited and that a joint GIS program may bring improved and new planning and executing capabilities for the DOD
Speedtrap: Internet-Scale IPv6 Alias Resolution
Proceedings of the Thirteenth ACM SIGCOMM Internet Measurement (IMC 2013) Conference, Barcelona, ES, October 2013.The article of record as published may be located at http://dx.doi.org/10.1145/2504730.2504759.Impediments to resolving IPv6 router aliases have precluded understanding the emerging router-level IPv6 Internet topology. In this work, we design, implement, and validate the first {\em Internet-scale alias resolution technique} for IPv6. Our technique, \st, leverages the ability to induce fragmented IPv6 responses from router interfaces in a particular temporal pattern that produces distinguishing per-router fingerprints. Our algorithm surmounts three fundamental challenges to Internet-scale IPv6 alias resolution using fragment identifier values: (1) unlike for IPv4, the identifier counters on IPv6 routers have no natural velocity, (2) the values of these counters are similar across routers, and (3) the packet size required to collect inferences is 46 times larger than required in IPv4. We demonstrate the efficacy of the technique by producing router-level Internet IPv6 topologies using measurements from CAIDA's distributed infrastructure. Our preliminary work represents a step toward understanding the Internet's IPv6 router-level topology, an important objective with respect to IPv6 network resilience, security, policy, and longitudinal evolution
Regulation of Response Properties and Operating Range of the AFD Thermosensory Neurons by cGMP Signaling
SummaryBackgroundThe neuronal mechanisms that encode specific stimulus features in order to elicit defined behavioral responses are poorly understood. C. elegans forms a memory of its cultivation temperature (Tc) and exhibits distinct behaviors in different temperature ranges relative to Tc. In particular, C. elegans tracks isotherms only in a narrow temperature band near Tc. Tc memory is in part encoded by the threshold of responsiveness (TâAFD) of the AFD thermosensory neuron pair to temperature stimuli. However, because AFD thermosensory responses appear to be similar at all examined temperatures above TâAFD, the mechanisms that generate specific behaviors in defined temperature ranges remain to be determined.ResultsHere, we show that the AFD neurons respond to the sinusoidal variations in thermal stimuli followed by animals during isothermal tracking (IT) behavior only in a narrow temperature range near Tc. We find that mutations in the AFD-expressed gcy-8 receptor guanylyl cyclase (rGC) gene result in defects in the execution of IT behavior and are associated with defects in the responses of the AFD neurons to oscillating thermal stimuli. In contrast, mutations in the gcy-18 or gcy-23 rGCs alter the temperature range in which IT behavior is exhibited. Alteration of intracellular cGMP levels via rGC mutations or addition of cGMP analogs shift the lower and upper ranges of the temperature range of IT behavior in part via alteration in TâAFD.ConclusionsOur observations provide insights into the mechanisms by which a single sensory neuron type encodes features of a given stimulus to generate different behaviors in defined zones
Yes/No Questions and Answers in the Map Task Corpus
We analyze question-answer pairs in a variety of ways, for three different kinds of yes/no questions. We find that the classification of yes/no questions described in (Carletta et al., 1995) for the Edinburgh map task corpus correlates well with whether a response will be a bare yes or no, a yes or no plus additional speech, or just speech without an overt yes or no. Correlation with responses described as âdirectâ or âindirectâ is less good. We also find that the strength of a questionâs expectation for a YES response correlates with the move type, the form of the response, and lexical yes choices; and that the move type correlates with the form of the question and with turn-taking schema
Sound-discrimination learning and auditory displays
Proceedings of the 9th International Conference on Auditory Display (ICAD), Boston, MA, July 7-9, 2003.Human listeners can learn to discriminate between sounds that are initially indistinguishable. To better understand the nature of this learning, we have been using behavioral techniques to examine training-induced improvements on basic auditory discrimination tasks. Here we report how multiple-hour training differentially affects the discrimination of sound frequency, intensity, location, and duration, and how learning on a given discrimination condition generalizes, or fails to generalize, to stimuli not encountered during training. We discuss how these data contribute to our understanding of discrimination learning and of the mechanisms underlying performance on particular trained tasks, and explore the implications of this learning for the design and evaluation of auditory displays
The effect of maternal dietary fat content and omega-6 to omega-3 ratio on offspring growth and hepatic gene expression in the rat
© The Authors 2020. Omega-6 fatty acids have been shown to exert pro-adipogenic effects whereas omega-3 fatty acids work in opposition. Increasing intakes of LA (linoleic acid; omega-6) vs ALA (alpha-linolenic acid; omega-3) in Western diets has led to the hypothesis that consumption of this diet during pregnancy may be contributing to adverse offspring health. This study investigated the effects of feeding a maternal dietary LA:ALA ratio similar to that of the Western diet (9:1) compared to a proposed 'ideal' ratio (âŒ1:1.5), at two total fat levels (18% vs 36% fat w/w), on growth and lipogenic gene expression in the offspring. Female Wistar rats were assigned to one of the four experimental groups throughout gestation and lactation. Offspring were culled at 1 and 2 weeks of age for sample collection. Offspring of dams consuming a -36% fat diet were âŒ20% lighter than those exposed to a 18% fat diet (
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Tracking Student Propositions in an Inquiry System
We built software to support student reasoning about a phenomenon and development of hypotheses to explain it. The goal is to engage students in asking questions, generating hypotheses and testing predictions. Rashi, an intelligent tutor, tracks studentsâ investigations (e.g., hypotheses, questions, data collection, and inferences) and helps articulate how evidence and theories are related. The tutor provides advice, such as recognizing when data does not support a hypothesis Cases are presented in geology, biology or engineering, and students are scaffolded to use an inquiry-based approach to posit a theory to explain the situation. Generic and reusable structured tools guide students through exploration of ill-structured problem spaces, supporting student knowledge and scaffolding reasoning and diagnostic skills
Tackling Change: Future-Proofing Water, Agriculture, and Food Security in an Era of Climate Uncertainty
In 1950 the global population was just over 2.5 billion. Now, in 2013, it is around 7 billion. Although population growth is slowing, the world is projected to have around 9.6 billion inhabitants by 2050. Most of the population increase will be in developing countries where food is often scarce, and land and water are under pressure. To feed the global population in 2050 the world will have to produce more food without significantly expanding the area of cultivated land and, because of competition between a greater number of water users, with less freshwater. On top of land and water constraints, food producers face climatic and other changes which will affect food production.
There remains great uncertainty as to how climate change will affect any given locality, but it seems likely that it will have a profound effect on water resources. Projected rises in average temperature, more extreme temperatures, and changes in precipitation patterns are likely to alter the amounts and distribution of rainfall, ice and snow melt, soil moisture, and river and groundwater flows. Now and in the future, agriculture and food security depend on managing waterâa finite resource, but variable in time and space
Tackling Change: Future-Proofing Water, Agriculture, and Food Security in an Era of Climate Uncertainty
In 1950 the global population was just over 2.5 billion. Now, in 2013, it is around 7 billion. Although population growth is slowing, the world is projected to have around 9.6 billion inhabitants by 2050. Most of the population increase will be in developing countries where food is often scarce, and land and water are under pressure. To feed the global population in 2050 the world will have to produce more food without significantly expanding the area of cultivated land and, because of competition between a greater number of water users, with less freshwater. On top of land and water constraints, food producers face climatic and other changes which will affect food production.
There remains great uncertainty as to how climate change will affect any given locality, but it seems likely that it will have a profound effect on water resources. Projected rises in average temperature, more extreme temperatures, and changes in precipitation patterns are likely to alter the amounts and distribution of rainfall, ice and snow melt, soil moisture, and river and groundwater flows. Now and in the future, agriculture and food security depend on managing waterâa finite resource, but variable in time and space
Tackling Change: Future-Proofing Water, Agriculture, and Food Security in an Era of Climate Uncertainty
In 1950 the global population was just over 2.5 billion. Now, in 2013, it is around 7 billion. Although population growth is slowing, the world is projected to have around 9.6 billion inhabitants by 2050. Most of the population increase will be in developing countries where food is often scarce, and land and water are under pressure. To feed the global population in 2050 the world will have to produce more food without significantly expanding the area of cultivated land and, because of competition between a greater number of water users, with less freshwater. On top of land and water constraints, food producers face climatic and other changes which will affect food production.
There remains great uncertainty as to how climate change will affect any given locality, but it seems likely that it will have a profound effect on water resources. Projected rises in average temperature, more extreme temperatures, and changes in precipitation patterns are likely to alter the amounts and distribution of rainfall, ice and snow melt, soil moisture, and river and groundwater flows. Now and in the future, agriculture and food security depend on managing waterâa finite resource, but variable in time and space
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